Comparative properties of plasmepsins from the P. falciparum 3D7 strain.
\\n\\n
Released this past November, the list is based on data collected from the Web of Science and highlights some of the world’s most influential scientific minds by naming the researchers whose publications over the previous decade have included a high number of Highly Cited Papers placing them among the top 1% most-cited.
\\n\\nWe wish to congratulate all of the researchers named and especially our authors on this amazing accomplishment! We are happy and proud to share in their success!
\\n"}]',published:!0,mainMedia:null},components:[{type:"htmlEditorComponent",content:'IntechOpen is proud to announce that 179 of our authors have made the Clarivate™ Highly Cited Researchers List for 2020, ranking them among the top 1% most-cited.
\n\nThroughout the years, the list has named a total of 252 IntechOpen authors as Highly Cited. Of those researchers, 69 have been featured on the list multiple times.
\n\n\n\nReleased this past November, the list is based on data collected from the Web of Science and highlights some of the world’s most influential scientific minds by naming the researchers whose publications over the previous decade have included a high number of Highly Cited Papers placing them among the top 1% most-cited.
\n\nWe wish to congratulate all of the researchers named and especially our authors on this amazing accomplishment! We are happy and proud to share in their success!
\n'}],latestNews:[{slug:"stanford-university-identifies-top-2-scientists-over-1-000-are-intechopen-authors-and-editors-20210122",title:"Stanford University Identifies Top 2% Scientists, Over 1,000 are IntechOpen Authors and Editors"},{slug:"intechopen-authors-included-in-the-highly-cited-researchers-list-for-2020-20210121",title:"IntechOpen Authors Included in the Highly Cited Researchers List for 2020"},{slug:"intechopen-maintains-position-as-the-world-s-largest-oa-book-publisher-20201218",title:"IntechOpen Maintains Position as the World’s Largest OA Book Publisher"},{slug:"all-intechopen-books-available-on-perlego-20201215",title:"All IntechOpen Books Available on Perlego"},{slug:"oiv-awards-recognizes-intechopen-s-editors-20201127",title:"OIV Awards Recognizes IntechOpen's Editors"},{slug:"intechopen-joins-crossref-s-initiative-for-open-abstracts-i4oa-to-boost-the-discovery-of-research-20201005",title:"IntechOpen joins Crossref's Initiative for Open Abstracts (I4OA) to Boost the Discovery of Research"},{slug:"intechopen-hits-milestone-5-000-open-access-books-published-20200908",title:"IntechOpen hits milestone: 5,000 Open Access books published!"},{slug:"intechopen-books-hosted-on-the-mathworks-book-program-20200819",title:"IntechOpen Books Hosted on the MathWorks Book Program"}]},book:{item:{type:"book",id:"3116",leadTitle:null,fullTitle:"Advances in Industrial Design Engineering",title:"Advances in Industrial Design Engineering",subtitle:null,reviewType:"peer-reviewed",abstract:'A fast paced changing world requires dynamic methods and robust theories to enable designers to deal with the new product development landscape successfully and make a difference in an increasingly interconnected world. Designers continue stretching the boundaries of their discipline, and trail new paths in interdisciplinary domains, constantly moving the frontiers of their practice farther. \nThis book, the successor to "Industrial Design - New Frontiers" (2011), develops the concepts present in the previous book further, as well as reaching new areas of theory and practice in industrial design. "Advances in Industrial Design Engineering" assists readers in leaping forward in their own practice and in preparing new design research that is relevant and aligned with the current challenges of this fascinating field.',isbn:null,printIsbn:"978-953-51-1016-3",pdfIsbn:"978-953-51-6319-0",doi:"10.5772/3415",price:119,priceEur:129,priceUsd:155,slug:"advances-in-industrial-design-engineering",numberOfPages:252,isOpenForSubmission:!1,isInWos:1,hash:"9cb2d954a2f9ea36c3d0f915a7fcd8ad",bookSignature:"Denis A. Coelho",publishedDate:"March 13th 2013",coverURL:"https://cdn.intechopen.com/books/images_new/3116.jpg",numberOfDownloads:32107,numberOfWosCitations:44,numberOfCrossrefCitations:39,numberOfDimensionsCitations:57,hasAltmetrics:1,numberOfTotalCitations:140,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"March 20th 2012",dateEndSecondStepPublish:"April 10th 2012",dateEndThirdStepPublish:"July 7th 2012",dateEndFourthStepPublish:"August 6th 2012",dateEndFifthStepPublish:"November 5th 2012",currentStepOfPublishingProcess:5,indexedIn:"1,2,3,4,5,6,7",editedByType:"Edited by",kuFlag:!1,editors:[{id:"38427",title:"Prof.",name:"Denis",middleName:null,surname:"Coelho",slug:"denis-coelho",fullName:"Denis Coelho",profilePictureURL:"https://mts.intechopen.com/storage/users/38427/images/1855_n.jpg",biography:"Professor Denis A. Coelho’s main teaching contribution has been stimulating the formation and initial operation of graduate courses in Industrial Design and MA in Industrial Design Engineering at UBI. He develops scientific activity within product design methodologies and has also conducted research in the field of ergonomic design and human requirements on technology, developed extensively in his doctoral work. Professor Coelho collaborates with several international research institutions in the areas of product design and ergonomics. The key area of his scientific activity is focused on the Human Interface located between technology and humans, which is characterized by an interdisciplinary nature, with technical and technological bias favouring an ergonomic perspective. His scientific activity also extends to product design methodologies, normalization applied to industrial management systems and production strategy in international networks. He is editor in chief of the International Journal of Human Factors and Ergonomics.",institutionString:null,position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"6",totalChapterViews:"0",totalEditedBooks:"2",institution:{name:"University of Beira Interior",institutionURL:null,country:{name:"Portugal"}}}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,coeditorOne:null,coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"797",title:"Design Engineering",slug:"industrial-engineering-and-management-design-engineering"}],chapters:[{id:"43353",title:"A Bi-Directional Method for Bionic Design with Examples",doi:"10.5772/53417",slug:"a-bi-directional-method-for-bionic-design-with-examples",totalDownloads:2667,totalCrossrefCites:1,totalDimensionsCites:2,signatures:"Carlos A. M. Versos and Denis A. Coelho",downloadPdfUrl:"/chapter/pdf-download/43353",previewPdfUrl:"/chapter/pdf-preview/43353",authors:[{id:"38427",title:"Prof.",name:"Denis",surname:"Coelho",slug:"denis-coelho",fullName:"Denis Coelho"},{id:"57380",title:"MSc.",name:"Carlos",surname:"Versos",slug:"carlos-versos",fullName:"Carlos Versos"}],corrections:null},{id:"43362",title:"Design Thinking in Conceptual Design Processes: A Comparison Between Industrial and Engineering Design Students",doi:"10.5772/52460",slug:"design-thinking-in-conceptual-design-processes-a-comparison-between-industrial-and-engineering-desig",totalDownloads:2929,totalCrossrefCites:2,totalDimensionsCites:0,signatures:"Hao Jiang and Ching-Chiuan Yen",downloadPdfUrl:"/chapter/pdf-download/43362",previewPdfUrl:"/chapter/pdf-preview/43362",authors:[{id:"38998",title:"Dr.",name:"Hao",surname:"Jiang",slug:"hao-jiang",fullName:"Hao Jiang"},{id:"154802",title:"Associate Prof.",name:"Ching-Chiuan",surname:"Yen",slug:"ching-chiuan-yen",fullName:"Ching-Chiuan Yen"}],corrections:null},{id:"43375",title:"Product Sound Design: Intentional and Consequential Sounds",doi:"10.5772/55274",slug:"product-sound-design-intentional-and-consequential-sounds",totalDownloads:2870,totalCrossrefCites:15,totalDimensionsCites:25,signatures:"Lau Langeveld, René van Egmond, Reinier Jansen and Elif Özcan",downloadPdfUrl:"/chapter/pdf-download/43375",previewPdfUrl:"/chapter/pdf-preview/43375",authors:[{id:"39586",title:"MSc.",name:"Lau",surname:"Langeveld",slug:"lau-langeveld",fullName:"Lau Langeveld"},{id:"156849",title:"MSc.",name:"Reinier",surname:"Jansen",slug:"reinier-jansen",fullName:"Reinier Jansen"},{id:"156854",title:"Dr.",name:"Rene",surname:"Van Egmond",slug:"rene-van-egmond",fullName:"Rene Van Egmond"},{id:"156855",title:"Dr.",name:"Elif",surname:"Ozcan",slug:"elif-ozcan",fullName:"Elif Ozcan"}],corrections:null},{id:"43585",title:"TRIZ: Design Problem Solving with Systematic Innovation",doi:"10.5772/55979",slug:"triz-design-problem-solving-with-systematic-innovation",totalDownloads:4040,totalCrossrefCites:11,totalDimensionsCites:12,signatures:"Helena V. G. Navas",downloadPdfUrl:"/chapter/pdf-download/43585",previewPdfUrl:"/chapter/pdf-preview/43585",authors:[{id:"153832",title:"Prof.",name:"Helena",surname:"Navas",slug:"helena-navas",fullName:"Helena Navas"}],corrections:null},{id:"43577",title:"The Design of Product Instructions",doi:"10.5772/54011",slug:"the-design-of-product-instructions",totalDownloads:2405,totalCrossrefCites:3,totalDimensionsCites:1,signatures:"Dian Li, Tom Cassidy and David Bromilow",downloadPdfUrl:"/chapter/pdf-download/43577",previewPdfUrl:"/chapter/pdf-preview/43577",authors:[{id:"39208",title:"Prof.",name:"Tom",surname:"Cassidy",slug:"tom-cassidy",fullName:"Tom Cassidy"}],corrections:null},{id:"43556",title:"Measuring Design Simplicity",doi:"10.5772/54753",slug:"measuring-design-simplicity",totalDownloads:1760,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Carlos A.M. Duarte",downloadPdfUrl:"/chapter/pdf-download/43556",previewPdfUrl:"/chapter/pdf-preview/43556",authors:[{id:"154479",title:"Ph.D.",name:"Carlos",surname:"Duarte",slug:"carlos-duarte",fullName:"Carlos Duarte"}],corrections:null},{id:"43555",title:"Sustainable Product Innovation: The Importance of the Front- End Stage in the Innovation Process",doi:"10.5772/52461",slug:"sustainable-product-innovation-the-importance-of-the-front-end-stage-in-the-innovation-process",totalDownloads:3919,totalCrossrefCites:6,totalDimensionsCites:15,signatures:"Kristel Dewulf",downloadPdfUrl:"/chapter/pdf-download/43555",previewPdfUrl:"/chapter/pdf-preview/43555",authors:[{id:"154290",title:"M.Sc.",name:"Kristel",surname:"Dewulf",slug:"kristel-dewulf",fullName:"Kristel Dewulf"}],corrections:null},{id:"43553",title:"Toy Design Methods: A Sustainability Perspective",doi:"10.5772/52858",slug:"toy-design-methods-a-sustainability-perspective",totalDownloads:2307,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Denis A. Coelho and Sónia A. Fernandes",downloadPdfUrl:"/chapter/pdf-download/43553",previewPdfUrl:"/chapter/pdf-preview/43553",authors:[{id:"38427",title:"Prof.",name:"Denis",surname:"Coelho",slug:"denis-coelho",fullName:"Denis Coelho"},{id:"154342",title:"MSc.",name:"Sónia",surname:"Fernandes",slug:"sonia-fernandes",fullName:"Sónia Fernandes"}],corrections:null},{id:"43544",title:"Design for Automotive Panels Supported by an Expert System",doi:"10.5772/52010",slug:"design-for-automotive-panels-supported-by-an-expert-system",totalDownloads:3802,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"Chun-Fong You, Chin-Ren Jeng and Kun-Yu Liu",downloadPdfUrl:"/chapter/pdf-download/43544",previewPdfUrl:"/chapter/pdf-preview/43544",authors:[{id:"51514",title:"Prof.",name:"Chun-Fong",surname:"You",slug:"chun-fong-you",fullName:"Chun-Fong You"}],corrections:null},{id:"43542",title:"Early Stages of Industrial Design Careers",doi:"10.5772/52857",slug:"early-stages-of-industrial-design-careers",totalDownloads:1686,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Inalda A. L. L. M. Rodrigues and Denis A. Coelho",downloadPdfUrl:"/chapter/pdf-download/43542",previewPdfUrl:"/chapter/pdf-preview/43542",authors:[{id:"38427",title:"Prof.",name:"Denis",surname:"Coelho",slug:"denis-coelho",fullName:"Denis Coelho"},{id:"154341",title:"MSc.",name:"Inalda",surname:"Rodrigues",slug:"inalda-rodrigues",fullName:"Inalda Rodrigues"}],corrections:null},{id:"43458",title:"Visual and Material Culture in the Context of Industrial Design: The Contemporary Nigerian Experience",doi:"10.5772/54548",slug:"visual-and-material-culture-in-the-context-of-industrial-design-the-contemporary-nigerian-experience",totalDownloads:3722,totalCrossrefCites:1,totalDimensionsCites:1,signatures:"I.B. Kashim",downloadPdfUrl:"/chapter/pdf-download/43458",previewPdfUrl:"/chapter/pdf-preview/43458",authors:[{id:"39941",title:"Dr.",name:"Isah Bolaji",surname:"Kashim",slug:"isah-bolaji-kashim",fullName:"Isah Bolaji Kashim"}],corrections:null}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},relatedBooks:[{type:"book",id:"323",title:"Industrial Design",subtitle:"New Frontiers",isOpenForSubmission:!1,hash:"6712ef0cc1fdf610d17e8aa70170f773",slug:"industrial-design-new-frontiers",bookSignature:"Denis A. Coelho",coverURL:"https://cdn.intechopen.com/books/images_new/323.jpg",editedByType:"Edited by",editors:[{id:"38427",title:"Prof.",name:"Denis",surname:"Coelho",slug:"denis-coelho",fullName:"Denis Coelho"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1802",title:"Manufacturing System",subtitle:null,isOpenForSubmission:!1,hash:"4db5cd5587e7ab1fe6e34507c103ee13",slug:"manufacturing-system",bookSignature:"Faieza Abdul Aziz",coverURL:"https://cdn.intechopen.com/books/images_new/1802.jpg",editedByType:"Edited by",editors:[{id:"109136",title:"Associate Prof.",name:"Faieza",surname:"Abdul Aziz",slug:"faieza-abdul-aziz",fullName:"Faieza Abdul Aziz"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1991",title:"Infrastructure Design, Signalling and Security in Railway",subtitle:null,isOpenForSubmission:!1,hash:"2151ad71a0cc7423ed852ab93d8c70f8",slug:"infrastructure-design-signalling-and-security-in-railway",bookSignature:"Xavier Perpinya",coverURL:"https://cdn.intechopen.com/books/images_new/1991.jpg",editedByType:"Edited by",editors:[{id:"111217",title:"Dr.",name:"Xavier",surname:"Perpinya",slug:"xavier-perpinya",fullName:"Xavier Perpinya"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9174",title:"Product Design",subtitle:null,isOpenForSubmission:!1,hash:"3510bacbbf4d365e97510bf962652de1",slug:"product-design",bookSignature:"Cătălin Alexandru, Codruta Jaliu and Mihai Comşit",coverURL:"https://cdn.intechopen.com/books/images_new/9174.jpg",editedByType:"Edited by",editors:[{id:"2767",title:"Prof.",name:"Catalin",surname:"Alexandru",slug:"catalin-alexandru",fullName:"Catalin Alexandru"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1373",title:"Ionic Liquids",subtitle:"Applications and Perspectives",isOpenForSubmission:!1,hash:"5e9ae5ae9167cde4b344e499a792c41c",slug:"ionic-liquids-applications-and-perspectives",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/1373.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"57",title:"Physics and Applications of Graphene",subtitle:"Experiments",isOpenForSubmission:!1,hash:"0e6622a71cf4f02f45bfdd5691e1189a",slug:"physics-and-applications-of-graphene-experiments",bookSignature:"Sergey Mikhailov",coverURL:"https://cdn.intechopen.com/books/images_new/57.jpg",editedByType:"Edited by",editors:[{id:"16042",title:"Dr.",name:"Sergey",surname:"Mikhailov",slug:"sergey-mikhailov",fullName:"Sergey Mikhailov"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],ofsBooks:[]},correction:{item:{id:"66066",slug:"erratum-microbial-responses-to-different-operating-practices-for-biogas-production-systems",title:"Erratum - Microbial Responses to Different Operating Practices for Biogas Production Systems",doi:null,correctionPDFUrl:"https://cdn.intechopen.com/pdfs/66066.pdf",downloadPdfUrl:"/chapter/pdf-download/66066",previewPdfUrl:"/chapter/pdf-preview/66066",totalDownloads:null,totalCrossrefCites:null,bibtexUrl:"/chapter/bibtex/66066",risUrl:"/chapter/ris/66066",chapter:{id:"65614",slug:"microbial-responses-to-different-operating-practices-for-biogas-production-systems",signatures:"Maria Westerholm and Anna Schnürer",dateSubmitted:"June 11th 2018",dateReviewed:"November 30th 2018",datePrePublished:"February 12th 2019",datePublished:"September 4th 2019",book:{id:"6839",title:"Anaerobic Digestion",subtitle:null,fullTitle:"Anaerobic Digestion",slug:"anaerobic-digestion",publishedDate:"September 4th 2019",bookSignature:"J. Rajesh Banu",coverURL:"https://cdn.intechopen.com/books/images_new/6839.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"218539",title:"Dr.",name:"Rajesh",middleName:null,surname:"Banu",slug:"rajesh-banu",fullName:"Rajesh Banu"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:[{id:"262546",title:"Prof.",name:"Anna",middleName:null,surname:"Schnürer",fullName:"Anna Schnürer",slug:"anna-schnurer",email:"anna.schnurer@slu.se",position:null,institution:null},{id:"263116",title:"Dr.",name:"Maria",middleName:null,surname:"Westerholm",fullName:"Maria Westerholm",slug:"maria-westerholm",email:"Maria.Westerholm@slu.se",position:null,institution:null}]}},chapter:{id:"65614",slug:"microbial-responses-to-different-operating-practices-for-biogas-production-systems",signatures:"Maria Westerholm and Anna Schnürer",dateSubmitted:"June 11th 2018",dateReviewed:"November 30th 2018",datePrePublished:"February 12th 2019",datePublished:"September 4th 2019",book:{id:"6839",title:"Anaerobic Digestion",subtitle:null,fullTitle:"Anaerobic Digestion",slug:"anaerobic-digestion",publishedDate:"September 4th 2019",bookSignature:"J. Rajesh Banu",coverURL:"https://cdn.intechopen.com/books/images_new/6839.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"218539",title:"Dr.",name:"Rajesh",middleName:null,surname:"Banu",slug:"rajesh-banu",fullName:"Rajesh Banu"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:[{id:"262546",title:"Prof.",name:"Anna",middleName:null,surname:"Schnürer",fullName:"Anna Schnürer",slug:"anna-schnurer",email:"anna.schnurer@slu.se",position:null,institution:null},{id:"263116",title:"Dr.",name:"Maria",middleName:null,surname:"Westerholm",fullName:"Maria Westerholm",slug:"maria-westerholm",email:"Maria.Westerholm@slu.se",position:null,institution:null}]},book:{id:"6839",title:"Anaerobic Digestion",subtitle:null,fullTitle:"Anaerobic Digestion",slug:"anaerobic-digestion",publishedDate:"September 4th 2019",bookSignature:"J. Rajesh Banu",coverURL:"https://cdn.intechopen.com/books/images_new/6839.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"218539",title:"Dr.",name:"Rajesh",middleName:null,surname:"Banu",slug:"rajesh-banu",fullName:"Rajesh Banu"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}}},ofsBook:{item:{type:"book",id:"10708",leadTitle:null,title:"Topics in Regional Anesthesia",subtitle:null,reviewType:"peer-reviewed",abstract:"\r\n\tThe goal of this book on Topics in Regional Anesthesia is to review selected subjects of importance in daily practice. Since the first years of the introduction of cocaine by Carl Koller in 1884, the evolution of regional anesthesia has been continuous, gradual and safe. Its development has been based on anatomy, the pharmacology of local anesthetics and adjuvant drugs, as well as advances in the various blocking techniques, with ultrasound guidance being the most recent advent. The use of ultrasound in regional anesthesia has shown the reduction of complications, which makes it mandatory to knowledge and acquire skills in all ultrasound-guided techniques.
\r\n\r\n\tUltrasound-guided regional blocks will be reviewed extensively, as well as intravenous regional anesthesia, thoracic spinal anesthesia. The role of regional anesthesia and analgesia in critically ill patients is of paramount importance. In addition, we will review the current role of regional techniques during the Covid-19 pandemic. Complications and malpractice is another topic that should be reviewed. Regional anesthesia procedures in some specialties such as pediatrics, orthopedics, cancer surgery, neurosurgery, acute and chronic pain will be discussed.
",isbn:"978-1-83969-570-4",printIsbn:"978-1-83969-569-8",pdfIsbn:"978-1-83969-571-1",doi:null,price:0,priceEur:0,priceUsd:0,slug:null,numberOfPages:0,isOpenForSubmission:!0,hash:"264f7f37033b4867cace7912287fccaa",bookSignature:"Prof. Víctor M. Whizar-Lugo and Dr. José Ramón Saucillo-Osuna",publishedDate:null,coverURL:"https://cdn.intechopen.com/books/images_new/10708.jpg",keywords:"Regional Anesthesia, Ultrasound-Guided Regional Anesthesia, Local Anesthetics, Preventive Analgesia, Peripheral Blocks, Pediatric Regional Anesthesia, Intravenous Regional Anesthesia, Techniques, Complications, Adjuvants in Regional Anesthesia, Opioids, Alfa2 Agonists",numberOfDownloads:null,numberOfWosCitations:0,numberOfCrossrefCitations:null,numberOfDimensionsCitations:null,numberOfTotalCitations:null,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"February 23rd 2021",dateEndSecondStepPublish:"March 23rd 2021",dateEndThirdStepPublish:"May 22nd 2021",dateEndFourthStepPublish:"August 10th 2021",dateEndFifthStepPublish:"October 9th 2021",remainingDaysToSecondStep:"18 days",secondStepPassed:!1,currentStepOfPublishingProcess:2,editedByType:null,kuFlag:!1,biosketch:"Dr. Whizar-Lugo has published more than 100 publications on Anesthesia, Pain, Critical Care, and Internal Medicine. He works as an anesthesiologist at Lotus Med Group and belongs to the Institutos Nacionales de Salud as an associated researcher.",coeditorOneBiosketch:null,coeditorTwoBiosketch:null,coeditorThreeBiosketch:null,coeditorFourBiosketch:null,coeditorFiveBiosketch:null,editors:[{id:"169249",title:"Prof.",name:"Víctor M.",middleName:null,surname:"Whizar-Lugo",slug:"victor-m.-whizar-lugo",fullName:"Víctor M. Whizar-Lugo",profilePictureURL:"https://mts.intechopen.com/storage/users/169249/images/system/169249.jpg",biography:"Víctor M. Whizar-Lugo graduated from Universidad Nacional Autónoma de México and completed residencies in Internal Medicine at Hospital General de México and Anaesthesiology and Critical Care Medicine at Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in México City. He also completed a fellowship at the Anesthesia Department, Pain Clinic at University of California, Los Angeles, USA. Currently, Dr. Whizar-Lugo works as anesthesiologist at Lotus Med Group, and belongs to the Institutos Nacionales de Salud as associated researcher. He has published many works on anesthesia, pain, internal medicine, and critical care, edited four books, and given countless conferences in congresses and meetings around the world. He has been a member of various editorial committees for anesthesiology journals, is past chief editor of the journal Anestesia en México, and is currently editor-in-chief of the Journal of Anesthesia and Critical Care. Dr. Whizar-Lugo is the founding director and current president of Anestesiología y Medicina del Dolor (www.anestesiologia-dolor.org), a free online medical education program.",institutionString:"Institutos Nacionales de Salud",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"5",totalChapterViews:"0",totalEditedBooks:"3",institution:null}],coeditorOne:{id:"345887",title:"Dr.",name:"José Ramón",middleName:null,surname:"Saucillo-Osuna",slug:"jose-ramon-saucillo-osuna",fullName:"José Ramón Saucillo-Osuna",profilePictureURL:"https://s3.us-east-1.amazonaws.com/intech-files/0033Y000033rFXmQAM/Profile_Picture_1611740683590",biography:"Graduated from the Facultad de Medicina de la Universidad Autónoma de Guadalajara, he specialized in anesthesiology at the Centro Médico Nacional de Occidente in Guadalajara, México. He is one of the most important pioneers in Mexico in ultrasound-guided regional anesthesia. Dr. Saucillo-Osuna has lectured at multiple national and international congresses and is an adjunct professor at the Federación Mexicana de Colegios de Anestesiología, AC, former president of the Asociación Mexicana de Anestesia Regional, and active member of the Asociación Latinoamericana de Anestesia Regional.",institutionString:"Centro Médico Nacional de Occidente",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"0",totalChapterViews:"0",totalEditedBooks:"0",institution:null},coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"16",title:"Medicine",slug:"medicine"}],chapters:null,productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"},personalPublishingAssistant:{id:"347258",firstName:"Marica",lastName:"Novakovic",middleName:null,title:"Dr.",imageUrl:"//cdnintech.com/web/frontend/www/assets/author.svg",email:"marica@intechopen.com",biography:null}},relatedBooks:[{type:"book",id:"6550",title:"Cohort Studies in Health Sciences",subtitle:null,isOpenForSubmission:!1,hash:"01df5aba4fff1a84b37a2fdafa809660",slug:"cohort-studies-in-health-sciences",bookSignature:"R. Mauricio Barría",coverURL:"https://cdn.intechopen.com/books/images_new/6550.jpg",editedByType:"Edited by",editors:[{id:"88861",title:"Dr.",name:"R. Mauricio",surname:"Barría",slug:"r.-mauricio-barria",fullName:"R. Mauricio Barría"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1373",title:"Ionic Liquids",subtitle:"Applications and Perspectives",isOpenForSubmission:!1,hash:"5e9ae5ae9167cde4b344e499a792c41c",slug:"ionic-liquids-applications-and-perspectives",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/1373.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"57",title:"Physics and Applications of Graphene",subtitle:"Experiments",isOpenForSubmission:!1,hash:"0e6622a71cf4f02f45bfdd5691e1189a",slug:"physics-and-applications-of-graphene-experiments",bookSignature:"Sergey Mikhailov",coverURL:"https://cdn.intechopen.com/books/images_new/57.jpg",editedByType:"Edited by",editors:[{id:"16042",title:"Dr.",name:"Sergey",surname:"Mikhailov",slug:"sergey-mikhailov",fullName:"Sergey Mikhailov"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"371",title:"Abiotic Stress in Plants",subtitle:"Mechanisms and Adaptations",isOpenForSubmission:!1,hash:"588466f487e307619849d72389178a74",slug:"abiotic-stress-in-plants-mechanisms-and-adaptations",bookSignature:"Arun Shanker and B. Venkateswarlu",coverURL:"https://cdn.intechopen.com/books/images_new/371.jpg",editedByType:"Edited by",editors:[{id:"58592",title:"Dr.",name:"Arun",surname:"Shanker",slug:"arun-shanker",fullName:"Arun Shanker"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"878",title:"Phytochemicals",subtitle:"A Global Perspective of Their Role in Nutrition and Health",isOpenForSubmission:!1,hash:"ec77671f63975ef2d16192897deb6835",slug:"phytochemicals-a-global-perspective-of-their-role-in-nutrition-and-health",bookSignature:"Venketeshwer Rao",coverURL:"https://cdn.intechopen.com/books/images_new/878.jpg",editedByType:"Edited by",editors:[{id:"82663",title:"Dr.",name:"Venketeshwer",surname:"Rao",slug:"venketeshwer-rao",fullName:"Venketeshwer Rao"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"4816",title:"Face Recognition",subtitle:null,isOpenForSubmission:!1,hash:"146063b5359146b7718ea86bad47c8eb",slug:"face_recognition",bookSignature:"Kresimir Delac and Mislav Grgic",coverURL:"https://cdn.intechopen.com/books/images_new/4816.jpg",editedByType:"Edited by",editors:[{id:"528",title:"Dr.",name:"Kresimir",surname:"Delac",slug:"kresimir-delac",fullName:"Kresimir Delac"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},chapter:{item:{type:"chapter",id:"53496",title:"Plasmepsin: Function, Characterization and Targeted Antimalarial Drug Development",doi:"10.5772/66716",slug:"plasmepsin-function-characterization-and-targeted-antimalarial-drug-development",body:'Malaria, a life‐threatening infectious disease, afflicts approximately 3.2 billion people, causes 214 million clinical cases and leads to nearly 440,000 deaths worldwide in 2015 despite the facts that malaria mortality rates decreased by 60% globally and by 66% in Africa between 2000 and 2015, and that malaria incidence rates decreased by 37% globally and by 42% in Africa for the past 15 years [1, 2]. Nearly 90% of the malaria cases and deaths occur in Sub‐Saharan Africa in 2015, loading a heavy socio‐economic burden to this poorly developed region [1].
Malaria is caused by parasitic protozoa of the genus Plasmodium. Hundreds of Plasmodium species have been identified to infect reptiles, birds and mammals, including rodents and primates. Four Plasmodium species pluralis (spp.), P. falciparum, P. vivax, P. malariae and P. ovale, are known to infect man, though other malarial species of non‐human primates occasionally infect human as well. Among these species, P. falciparum is the most deadly and P. vivax, the most prevalent. P. falciparum invades both young and mature erythrocytes and provokes malignant disease symptoms. Prevalent mainly in Africa, P. falciparum accounts for ~40% of the clinical cases on a global basis [1]. In contrast, P. vivax prefers invading young erythrocytes and causes benign symptoms; it has a wider geographical distribution than P. falciparum and is responsible for half of the total reported cases [1].
To complete its life cycle, the malaria parasite requires a female mosquito as the transmission vector and a vertebrate host (Figure 1). When a blood meal is taken, a parasite‐infected mosquito inoculates sporozoites into the human host to start the exo‐erythrocytic phase, in which sporozoites infect hepatocytes and mature into schizonts. Of note, in parasites such as P. vivax and P. ovale, a dormant stage, namely hypnozoites, can maintain in hypatic cells for weeks or even years before invading the bloodstream. Rupture of schizonts releases merozoites, which then infect erythrocytes to initiate the intra‐erythrocytic phase. In this phase, the parasite undergoes multiple rounds of asexual replication with each cycle comprising, in sequence, the ring, the trophozoite and the schizont stage. A portion of merozoites infect erythrocyte to differentiate into gametocytes. Microgametocytes and macrogametocytes are ingested by a mosquito to start the sporogonic phase. In the mosquito\'s stomach, gametocytes further differentiate into gametes. Microgametes fertilize macrogametes to generate zygotes, which subsequently develop into motile and elongated ookinetes. Ookinetes penetrate the midgut of the mosquito and develop into oocysts, from which sporozoites are released and delivered to the mosquito\'s salivary gland, ready for the next infection.
The life cycle of malaria parasites. Malaria parasites require a transmission vector (e.g., mosquito) and a vertebrate host (e.g., human) to complete their life cycle. The exo‐erythrocytic and intra‐erythrocytic phases occur in the vertebrate host, and the sporogonic phase occurs in the transmission vector.
Malaria control in the modern era arguably starts from the isolation of antimalarial quinine and quinidine from cinchona bark in early nineteenth century [3], while it was not until 1925 that pamaquine (also known as plasmoquine or plasmochin), the first synthetic antimalarial drug, was yielded. Synthesized in 1934, chloroquine (CQ), a 4‐aminoquinoline compound, exhibited a strong antimalarial potency and a low toxicity and became the most extensively used drug in malaria prophylaxis and treatment between 1940s and 1960s [4–6]. The massive use of CQ, however, resulted in the emergence of CQ‐resistant P. falciparum strains, which promoted development of novel antimalarial drugs (e.g., 8‐aminoquinolines, antifolates, naphthoquinones and non‐antifolate antibiotics). Of particular note among these compounds is artemisinin (AN). Extracted from the herbal plant Artemisia annua, AN, has been used for malaria treatment since early 1970s [7]. Though AN and its various derivatives display high antimalarial activities (e.g., [8–12]) and quick attenuation of disease symptoms [13], they have short half lives in vivo [14]. The combination of AN and a longer‐acting drug (e.g., artemether‐lumefantrine and artesunate‐mefloquine) is effective for disease treatment and for deferring drug resistance development. Artemisinin‐based combination therapies (ACTs) have up till now been used as a standard therapy in many countries and regions despite potentially unmatched pharmacokinetics between drugs and/or widespread resistance against the non‐artemisinin components. Malaria control was also carried out by intervention of disease transmission, thanks to the discovery of insecticidal properties of dichloro‐diphenyltrichloroethane (DDT) in 1939 [15]. Due to health and environmental risks, DDT was later substituted by other insecticides, such as pyrethroids, chlorfenapyr and pyriproxyfen. While both indoor residual spraying and insecticide‐treated bed nets contribute to controlling epidemic outbreaks of malaria, the latter provide more effective protection for people living in temporary shelters. Nonetheless, one cannot ignore the growing emergence of insecticide‐resistant vector strains and the lack of interventions targeting outdoor mosquito populations, which constitute major challenges in blocking malaria transmission. Intervention of malaria transmission has also been managed via biological control of mosquitoes at both the larval and the adult stage. Several fish species, such as Poecilia reticulate (guppy) and Gambusia affinis (mosquitofish), are able to consume mosquito larvae and reduce their population; however, these fish also pose a threat to other native aquatic predators of mosquitoes due to intraguild predation [16, 17]. In contrast, the larval dytiscid beetles Agabus do exhibit a selective predation on mosquitoes over alternative prey, although intraguild predation and cannibalism also occur within and between Agabus species [18]. In addition, the use of water‐dispersible granular formulation of two Bacillus species in malaria control results in an efficacious elimination of the larval mosquito population with a negligible environmental impact [19]. Also of note is the use of fungi for malaria control. Ground and aerial application of self‐propagating Lagenidium giganteum effectively controls the larval mosquito population for at least an entire breeding season [20, 21]. Oil‐based formulations of fungal entomopathogens are able to block malaria transmission by reducing adult mosquito survival and altering parasite survival/maturation in the vector [22]. Further, transgenic fungi Metarhizium anisopliae targeting sporozoites in mosquitoes inhibit parasite development [23]. These pieces of evidence indicate the potential of fungi as a biocontrol agent of mosquitoes. Natural products are another important source utilized to control malaria transmission. A variety of plant extracts and essential oils (e.g., the neem oil, the fenugreek oil and the extracts from Indian sandalwood) exhibit larvicidal activities and adult mosquito repellency properties (for example, see [24–30]). Moreover, natural product‐synthesized silver nanoparticles show a higher potency in mosquitocidal activity than the aqueous extracts but their toxicity against other natural mosquito consumers is negligible (for example, see [31–33]). These, in addition to the time‐efficiency, cost‐effectiveness and eco‐friendliness green‐synthesis of nanoparticles, suggest the feasibility and importance of a synergistic mosquito control using botanical nano‐insecticides and biological agents. Besides these antimalarial approaches, vaccines against malaria parasites have been under development since 1970s [34, 35]. Malaria vaccines are categorized into three types: exo‐erythrocytic vaccines, blood‐stage vaccines and transmission‐blocking vaccines; sustainable prevention requires a combination of vaccines targeting multiple life stages of the parasite. RTS,S/AS01, the first and thus far the only vaccine that completes a Phase III clinical trial, targets the exo‐erythrocytic phase of P. falciparum. Though this vaccine demonstrates a decent efficacy for prevention of clinical malaria cases in African children (age 5–17 months, efficacy 50%) and infants (age 6–12 weeks, efficacy 30%) [36], an ideal candidate aiming for global eradication would require a higher efficacy [37].
A major challenge faced by the anti‐malaria campaign currently is the emergence and rapid spread of drug‐resistant variants of Plasmodium spp. [38]. Malaria parasites have developed resistance to virtually every type of antimalarial drugs thus far used, including AN and its derivatives [39]. The lack of effective treatment of symptoms caused by drug‐resistant parasites urges us to identify molecular targets, against which novel drugs can be subsequently developed to combat malaria. Plasmepsins (PMs), a family of aspartic proteinases, are considered a promising drug target.
This review focuses on the biosynthesis, biological functions and enzymatic characteristics of the plasmepsin (PM) family from human malaria parasites. The progression of PM‐targeted antimalarial drug development is also discussed.
From comparative genomic analysis of sequence information of seven Plasmodium spp. deposited in the Plasmodium genome database [40], a cohort of genes that encode PMs were identified and categorized into seven groups based on their amino acid sequence identity [41]. In P. falciparum, up to ten PMs have thus far been identified, namely PfPMs 1, 2, 4–10 and PfHAP (Histo‐Aspartic Proteinase) [42]. These PMs, encoded by genes located in five different chromosomes, are composed of the pro‐segment and the mature enzyme domain. PfPM5 and PfPM9 also contain extra residues at their C‐termini. PMs are distinct in structural and biochemical properties, such as molecular weight and isoelectric point (Table 1).
PM | Chr. | Pro | Zymogen | Mature enzyme | ||||||
---|---|---|---|---|---|---|---|---|---|---|
# a.a. | # a.a. | % i.d. | MW (Da) | pI | # a.a. | % i.d. | MW (Da) | pI | ||
PM1 | 14 | 123 | 452 | 62 | 51,461 | 7.23 | 329 | 70 | 37,050 | 4.82 |
PM2 | 14 | 124 | 453 | 61 | 51,481 | 5.29 | 329 | 69 | 36,915 | 4.62 |
HAP | 14 | 123 | 451 | 52 | 51,694 | 8.23 | 328 | 59 | 36,979 | 4.97 |
PM4 | 14 | 121 | 449 | — | 51,047 | 5.19 | 328 | — | 36,955 | 4.38 |
PM5 | 13 | 83 | 590 | 25 | 68,481 | 7.66 | 440 | 25 | 50,844 | 6.50 |
PM6 | 3 | 84 | 432 | 29 | 49,434 | 7.75 | 348 | 29 | 39,352 | 6.44 |
PM7 | 10 | 76 | 450 | 28 | 52,329 | 8.44 | 374 | 28 | 43,317 | 6.09 |
PM8 | 14 | 45 | 385 | 26 | 44,255 | 9.38 | 340 | 29 | 38,976 | 8.85 |
PM9 | 14 | 212 | 627 | 27 | 74,184 | 9.63 | 402 | 25 | 46,970 | 9.28 |
PM10 | 8 | 232 | 573 | 30 | 65,115 | 5.22 | 341 | 29 | 38,604 | 5.38 |
Comparative properties of plasmepsins from the P. falciparum 3D7 strain.
The % i.d. data is calculated using the Basic Local Alignment Search Tool [43]. The MW and pI data of zymogens are adopted from the Plasmodium Genomics Resource [44]. The MW and pI data of mature enzymes are calculated using ProtParam [45]. Abbreviations: Pro, pro-segment; # a.a., numbers of amino acids; % i.d., percentage of identity versus PM4.
Of note, pfpm4, pfpm1, pfpm2 and pfhap cluster in a 20‐kb‐long region of chromosome 14, and share a high amino acid sequence identity (Table 1). Each non‐falciparum parasite, however, harbors usually one gene (pm4) that shares with pfpm4 the highest sequence identity, which is comparable to those shared among the four pfpms. It is believed that the other three PM genes may arise from multiple gene duplication events [41]. Since these four PM paralogs were initially detected in the food vacuole (FV), an acidic organelle unique to the genus Plasmodium where degradation of hemoglobin of red blood cells (erythrocytes) occurs [46–48], they are named the FV PfPMs. PM4s of the non‐falciparum species are also grouped as FV PMs because they are highly homologous to the FV PfPMs. PfPMs 5–10 share a low amino acid sequence identity with the FV PfPMs, and their sequence structures are distinct from each other and from those of the FV PfPMs (Table 1), indicating that there exist diverse biological functions and enzymatic features among the PM family members.
FV PfPMs are synthesized as type II integral membrane proteins, with the putative transmembrane motif residing in the N‐terminal pro‐segment. Using immunoelectron microscopy (immunoEM), PfPM1 and PfPM2 were observed in the lumens of transport vesicles and FVs, in the parasite plasma membrane (PPM), in small vesicular structures near PPM and in the cytostome, a morphologically variable microstructure comprising invaginated parasitophorous vacuolar membrane (PVM) and PPM [46] (Figure 2). Further, Klemba and colleagues probed the trafficking of PfPM2 in a transgenic P. falciparum culture model [49]. The PfM2‐green fluorescence protein (GFP) fusion protein was detected by immunoEM in the membrane and lumen of FVs and in the cytostomes, consistent with the previous finding [46]. Administration of brefeldin A (BFA), an inhibitor blocking anterograde protein traffic from the endoplasmic reticulum (ER), to trophozoites retained PfPM2‐GFP in the ER/nuclear envelope (NE); yet this protein was detected in the cytostomes and subsequently the FVs min-utes after release of the BFA inhibition. The role of Golgi apparatus in the biosynthesis of FV PfPMs is not yet clear, but is doubtful, since FV PfPMs are known to be unglycosylated. Taken together, these findings suggest that the biosynthesis of FV PfPMs follows an “ER‐to‐PPM‐to‐FV” route (Figure 2). Interestingly, PfPM2 has also been detected in the cytoplasm of host erythrocytes (see Section 4.2 for more discussion), leading to the hypothesis that there exists an alternative traffic route for the FV PMs.
Biosynthesis of plasmepsins in the P. falciparum intra‐erythrocytic phase. Food vacuole plasmepsins from P. falciparum (FV PfPMs) are expressed as type II integral membrane proteins with their N‐terminal pro‐segments (orange threads) spanning the endoplasmic reticulum/nuclear envelope (ER/NE) membrane. FV PfPMs are transported via small vesicular structures to the parasite plasma membrane (PPM), where some reside in the cytostomal vacuole. The involvement of Golgi apparatus in this secretory pathway is not clear. Endocytosis of cytostomes retains FV PfPMs in transport vesicles, which convey the enzymes eventually to the FV. Maturation of the FV PfPMs is carried out in the acidic FVs and transport vesicles. Certain FV PfPMs (e.g., PfPM2) are also found functionally active in the host erythrocytes, though how they are secreted outside the parasite is not yet clear. In contrast, PfPM5 is an ER‐resident, type I integral membrane protein. PV, parasitophorous vacuole; PVM, parasitophorous vacuolar membrane.
To gain catalytic activity, FV PMs need to release their pro‐segments. The cleavage site is conserved at the motif (Y/H)LG* (S/N)XXD (* represents the scissile bond) [50], which is different from the sites where in vitro PM auto‐maturation occurs ([48, 51–54], see also discussion in Section 5). This observation suggests that PM maturation in the parasite is a convertase‐catalyzed trans‐processing event. Further studies showed that the pro‐segment cleavage of naturally‐occurring PMs occurs in an acidic milieu, is largely completed within half an hour in cultured P. falciparum at the trophozoite stage, and is inhibited by tripeptide aldehyde N‐acetyl‐Leu‐Leu‐norleucinal (ALLN) or N‐acetyl‐Leu‐Leu‐methioninal [50, 55]. The identity of the convertase is believed to be the cysteine proteinases falcipain (FP) ‐2 and ‐3 in that (1) both FP‐2 and FP‐3 catalyze cleavage of peptide substrates at the C‐terminus of the conserved glycine; (2) a membrane‐permeant derivative of the cysteine proteinase inhibitor E‐64 directly binds to FP‐2 and FP‐3 and, in turn, slows the kinetics of PM maturation in cultured parasites; and (3) both FPs are inhibited by ALLN at low micromolar magnitude in vitro [56]. Of note, when FPs are inhibited, the parasite can use PMs (e.g. PfPM2) as alternative convertases [56], though it is not known yet whether and to what degree this alternative processing is employed.
Where does the maturation of FV PMs occur? Evidence from immunoEM shows that antibodies directed against N‐terminal epitopes of mature PfPM1 and PfPM2 recognize the enzymes not only in the FV but also in transport vesicles [46, 49]. Of note, hemozoin crystals stemmed from hemoglobin degradation that is initiated and carried out by mature FV PMs are also observed in both the FVs and transport vesicles [57]. These findings indicate that both subcellular compartments contain catalytically active PMs. In addition, the finding that functional vacuolar proton pumps are present in the PPM [58, 59], the outer membrane of transport vesicles, suggests that the vesicular milieu is acidic. Taken together, it is conceivable that the convertase‐catalyzed PM maturation also occurs in transport vesicles.
The four FV PfPMs exhibit distinct temporal expression patterns in the intra‐erythrocytic phase of the parasite life cycle: PfPM1 and PfPM2 emerge as early as the ring stage, PfPM4 first appears in the early trophozoite stage, and yet PfHAP is not detected until the mid‐trophozoite stage; all the four continue to be expressed at the schizont stage [48]. This is expected since the FV PfPMs are key enzymes to hemoglobin processing, and PfPM1 and PfPM2 are believed to initiate that event (for more discussion, see Section 4.1). Importantly, expression of these FV PfPMs is not restricted in trophozoites and schizonts in that mass spectrometry (MS)‐based analyses have identified their presence in gametocytes, merozoites, oocysts and sporozoites [60–62].
No studies, to the author\'s knowledge, have been reported on biosynthesis of the FV PMs from non‐falciparum species. It is likely that they adopt a similar pattern as the PfPMs due to the high sequence identity shared among these homologs.
Among the non‐FV PMs, PM5 is the most studied. PfPM5 is synthesized as a type I integral membrane protein comprising an N‐terminal pro‐segment, a catalytic domain, a C‐terminal transmembrane domain and a cytoplasmic tail [63]. Notably, the sequence of the pro‐segment region of PM5 is highly variable among Plasmodium spp. [44]. PfPM5 is almost exclusively detected in the ER/NE (Figure 2) [63]. The C‐terminal transmembrane domain is essential to the ER/NE residence of PfPM5 [64]. Expression of PfPM5 is detected throughout the life cycle of the parasite [44, 65, 66]; in the intra‐erythrocytic phase, PfPM5 expression starts at the early ring stage in a scarce level and continues to increase steadily through the trophozoite and schizont stages, which mirrors the temporal expression patterns of PfPM1 and PfPM2 [48, 63]. Interestingly, in contrast to the rapid maturation of the FV PfPMs, no processing of the N‐terminal pro‐segment is observed hours after the synthesis of PfPM5; also unlike the FV PfPMs, PfPM5 is catalytically active in the presence of the pro‐segment [63].
Few studies have addressed the biosynthesis of PMs 6–10. Genes encoding PfPM9 and PfPM10, but not PfPMs 6–8, are transcribed in parasites infecting erythrocytes [67]. In the intra‐erythrocytic phase, PfPM9 and PfPM10 exhibit a diffuse expression pattern throughout the cytoplasm, but are excluded from the FV [48]. Of note, MS‐based analysis indicates the presence of PfPM9 in sporozoites and the presence of both PfPM6 and PfPM10 in merozoites and sporozoites [60–62]. In addition, expression of PfPM7 and PfPM10 is detected in zygotes and ookinetes [68, 69].
The primary pathological role that FV PMs play is digestion and degradation of the oxygen‐carrying hemoglobin that constitutes 95% of cytosolic proteins of human red blood cells (Figure 3).
A diagram illustrating the connections of plasmepsins and their known biological functions.
In the intra‐erythrocytic phase, hemoglobin digestion and degradation is carried out between the ring and the early schizont stage [70, 71]. A vast majority of hemoglobin, at a millimolar concentration in erythrocytes, however, is processed within the 6–12‐hour trophozoite stage [72], indicative of an enzyme‐catalyzed event. The processing of hemoglobin occurs mainly in FVs; however, it is also carried out in vesicles arising either from micropinocytosis of cytoplasm of host cells or from endocytosis of cytostomes [57].
Early investigations establish that aspartic and cysteine proteinase activities are responsible for hemoglobin processing [73–81]. The successful isolation of FV from cultured trophozoites renders possible identification of naturally‐occurring hemoglobin‐processing enzymes [82]. PfPM1, the first proteinase purified from isolated FVs, exhibits its cleavage specificity at the α‐subunit amino acids F33‐L34 (α33‐34) of native hemoglobin [83]. Located in a highly conserved region among vertebrate species [84], this peptide bond is essential for maintaining the quaternary structure of the hemoglobin tetramer [85]. Breaking the α33‐34 bond unravels the molecule and, in turn, leads to additional enzyme cleavages of the α‐ and β‐subunits [47]. Sharing a 73% amino acid sequence identity with PfPM1, PfPM2, the second proteinase purified from FVs, also cleaves native hemoglobin at α33‐34, though less efficiently than PfPM1 [47]. SC‐50083, a selective inhibitor of PfPM1 over PfPM2 by two orders of magnitude [46], blocks a majority of native hemoglobin degradation by FV protein extracts [47], indicating that PfPM1 initiates the proteolysis. Of note, both PfPM1 and PfPM2 can further digest denatured globin into smaller peptides [47]. A third FV PM, PfHAP, purified from FVs, cleaves native hemoglobin even less efficiently than PfPM2 does and yet shows an efficiency in degrading denatured globin equivalent to PfPM2 [48]. Similar to PfHAP, PfPM4 of the recombinant form prefers degrading denatured globin than native hemoglobin [48]. Other proteolytic enzymes, such as the cysteine proteinase falcipains, the metallo-proteinase falcilysin and aminopeptidases, are actively involved in further degrading hemoglobin fragments to oligopeptides and amino acids [42, 86]. These findings indicate that hemoglobin digestion and degradation in P. falciparum is an ordered process, in which PfPM1 and PfPM2 initiate the cleavage and various proteinases are involved in additional processing. Hemoglobin processing in other human malaria parasites may depend on their FV PMs that are homologous to PfPM4.
The purpose of hemoglobin digestion and degradation has been under debate. Some believe that malaria parasites consume hemoglobin as a source of nutrients [87–91], which is supported by their limited capacity to de novo synthesis [88, 92] or exogenous amino acid uptake [93]. Nonetheless, hemoglobin degradation alone seems insufficient to maintain parasite metabolism due to its low contents of cysteine, glutamine, glutamic acid and methionine and its lack of isoleucine; in addition, hemoglobin‐derived amino acids are found diffused into the host cell [89], indicating an excessive amount of hemoglobin being processed. This leads to a second hypothesis positing that the parasites degrade hemoglobin to empty space for their development and growth [94]. A third hypothesis, supported by an experimental‐based modeling study, is that hemoglobin degradation is necessary to maintain the osmotic stability of infected erythrocytes such that the malaria parasite is able to grow and replicate in integrated host cells [95].
PfPM2 plays a role in remodeling host erythrocytes. In cultured schizonts, PfPM2 was observed in the cytoplasm of the host cell in addition to the parasite [96], suggesting its potential interactions with cytoskeleton proteins. In support of this finding, recombinant PfPM2 exhibits hydrolysis of spectrin, actin and protein 4.1 at near neutral pH conditions [96]. In addition, schizont‐expressed, naturally‐occurring PfPM2, but not PfPM1 or falcipains, is enriched in the size exclusion chromatography (SEC) fractions that show proteolytic activity of the SH3 motif of the cytoskeletal protein spectrin [96], thus supporting its host cell remodeling role at the mature stage of the intra‐erythrocytic phase. Of note, recombinant PfPM4 hydrolyzes spectrin at pH 6.6 in a similar pattern as recombinant PfPM2 does [97]. Further, a 37‐kDa aspartic proteinase purified from the rodent malaria parasite P. berghei enables hydrolysis of spectrin and protein 4.1 from human erythrocytes at physiological pH [98]. Based on these pieces of evidence, it is likely that the FV PM‐mediated host cell remodeling commonly occurs in the intra‐erythrocytic phase of Plasmodium spp. (Figure 3).
PM4 (PgPM4) from the avian malaria parasite P. gallinaceum is involved in ookinete invasion of mosquito midguts and oocyst development during the sporogonic phase (Figure 3) [99]. In its mosquito host, P. gallinaceum expresses PgPM4 in zygotes and ookinetes. In ookinetes, PgPM4 is located at the apical membrane surface as well as in micronemes, an organelle of apicomplexan parasites involving in protein secretion. Monoclonal antibodies directed against PgPM4 block oocyst development, but have no effects on ookinete formation. PgPM4, together with chitinase and other enzymes, is speculated to hydrolyze peritrophic matrix proteins during ookinetes’ midgut invasion, a critical step for parasite development. Questions remain elusive, such as how the expression of PgPM4 and its orthologs is spatio‐temporally regulated in the life cycle of malaria parasites, whether PM4 orthologs from other Plasmodium spp. play a similar role, what the natural substrates of PgPM4 are, and how PgPM4 recognizes and cleaves its substrates.
Of particular note, antibodies directed against the catalytic domain of either PfPM7 or PfPM10 decrease the prevalence of P. falciparum invasion of the mosquito and reduce the intensity of developed oocysts [69], indicating the involvement of mature PfPM7 or PfPM10 in parasite development during the sporogonic phase as well.
In the intra‐erythrocytic phase, malaria parasites express and export hundreds of proteins, collectively named the “exportome,” to infected red blood cells in order to acquire nutrients, to remodel the host cell, to avoid host immune detection, and to promote virulence [100–102]. A portion of the exportome shares at the N‐terminus a pentameric sequence motif of RxLxE/Q/D (x represents any natural amino acid), known as the Plasmodiumexport element (PEXEL) [101] or the vacuolar transport signal [100]. A cleavage of the PEXEL motif at the C‐terminus of leucine triggers the PEXEL‐containing proteins to traverse the PPM and PVM, and subsequently reach the host cell [103]. PM5 catalyzes this reaction in the ER following the translation of PEXEL‐containing proteins (Figure 3) [64, 104].
PM5‐mediated PEXEL cleavage is proved to be essential to not only protein export but also parasite survival in that episomal expression of a catalytically inactive PM5 mutant decreases the level of proteins exported to host cells and slows down the parasite growth rate [64]. Interestingly, when the PEXEL motif of the P. falciparum erythrocyte membrane protein 3 (PfEMP3) is engineered such that a signal peptidase, but not PM5, is able to conduct the cleavage, the resulting protein is transported to the parasitophorous vacuole rather than the cytoplasm of host cell, even if it has the same acetylated‐xQ sequence retaining at the N‐terminus as the PM5‐cleaved mature PfEMP3 does [104]. Meanwhile, when proteins are engineered to alter the prime side sequence of the PEXEL motif, the processed mature proteins fail to export to host erythrocytes even if PM5 performs the cleavage [105]. These findings highlight the importance of both PM5\'s involvement in the cleavage and the exposure of appropriate N‐terminal sequence of the mature protein in host‐targeted protein export. Detailed mechanisms related to how PM5‐mediated PEXEL cleavage contributes to host‐targeted protein export, and other potential roles of PM5 in the protein export event remain elusive.
Of particular note, the host‐targeted malaria protein export is not restricted in the intra‐erythrocytic phase but occurs over the course of the parasite life cycle [66, 106, 107], which coincides with the spatio‐temporal expression pattern of PM5 [44, 65, 66]. It is thus conceivable that PM5 is also involved in protein export at other stages of the parasite life cycle, though no supporting evidence has been reported yet.
Recent studies from Spaccapelo and colleagues showed the role of PM4 (PbPM4) from the rodent malaria parasite P. berghei in maintaining virulence and suppressing innate immune responses of parasite‐infected mice (Figure 3) [108, 109]. Supporting evidence comes from the observations that (1) the parasite with pbpm4 genetically ablated (Δpbpm4) fails to elicit experimental cerebral malaria (ECM) in the ECM‐susceptible mice; (2) the Δpbpm4 is unable to kill the ECM‐resistant mice as the parent strain does, but is cleared from blood after a three‐week infection; and (3) after a single infection of naïve hosts by the Δpbpm4, these convalescent mice gain immune protection from a later parent strain infection. The mechanism by which PbPM4 contributes to parasite virulence warrants further investigation.
In another study [110], recombinant PbPM4 expressed and purified from E. coli was injected intraperitoneally (i.p.) in mice, together with the adjuvant saponin; sera obtained from the immunized mice contain antibodies that can recognize the cultured P. berghei strain from which the immunogen‐encoding sequence originates. In addition, i.p. injecting erythorcytes infected by this P. berghei strain into PbPM4‐immunized mice boosts their production of the parasite‐recognizing antibodies in vivo. Interestingly, three of five PbPM4‐immunized mice show resistance to P. berghei infection with the parasitaemia percentage reduced by an order of magnitude compared to naïve mice. These findings suggest that PMs are able to serve both as drug targets and as immunogens for malaria control (Figure 3). Though whether PM4 homologs residing in the host‐infecting parasites are able to elicit a similar immune response as purified recombinant forms is not yet clear, their potential immunogenic role in malaria prevention and treatment merits further investigation.
The naturally‐occurring PfPM1 runs as a 37‐kDa monomeric protein in SEC, indicative of its mature form [47, 83]. Purified naturally‐occurring PfPM1 hydrolyzes native hemoglobin at α33‐34 at an optimal pH 5.0 [83], within the pH range of the FV [111, 112]. This reaction is fully inhibited by pepstatin, a typical aspartic proteinase inhibitor, at nanomolar magnitude, but little by serine, cysteine or metallo‐proteinase inhibitors in the millimolar range [83].
PfPM1 of the recombinant form was expressed in E. coli. To obtain catalytically active mature enzyme, two technical obstacles were overcome: first, to avoid the potential toxicity the putative transmembrane motif exerts to E. coli, a truncated construct lacking the N‐terminal half of the pro‐segment was used [113]; second, to confer the auto‐maturation capability on the truncated zymogen, this PfPM1 construct was further engineered by introducing a self‐cleavage site in the pro‐segment [51, 52], by retaining a longer pro‐segment [114], or by co‐expressing with thioredoxin in one open reading frame [115]. These engineered PfPM1s conduct auto‐maturation at pH 4.0–5.5; however, the resulting mature enzyme retains a 7‐ or 12‐amino‐acid pro‐segment [51, 52, 115]. Furthermore, the PfPM1 produced by auto‐maturation in vitro shows unanimously weaker kinetic efficiencies (kcat/Km) in cleaving hemoglobin‐derived substrates than the naturally‐occurring, mainly due to lower kcat values [52, 115, 116]. These findings suggest that the presence of a short piece of pro‐segment in the in vitro auto‐matured PfPM1 inhibits the enzyme activity and that the inhibition may occur in a different way than that it directly occupies the active site, like the case of pepsinogen and progastricsin [117–120]. In support of this, a crystal structure of the highly homologous PfPM2 zymogen demonstrates that the pro‐segment blocks enzyme activity by harnessing the C‐terminal domain away from the N‐terminal half to prevent the cooperative action of the catalytic dyad [120, 121].
The subsite specificity of PfPM1 at S3 – S3\' was analyzed using combinatorial chemistry‐based peptide libraries [52]. In this study, the degree of accommodation of each of the 19 amino acids (i.e., norleucine and the 20 natural amino acids omitting methionine and cysteine) at each of the six subsites was quantitatively assessed. Ultimately, the peptide sequence comprising the best accommodated amino acid at each investigated position, in the order of P3–P3\', is FSF*LQF (* represents the scissor bond). By comparing data to those obtained using the same method from analyzing human cathepsin D (hcatD), the most homologous human enzyme to FV PMs, a peptide sequence was deduced comprising at each position an amino acid that is well fit in PfPM1, but better recognized by PfPM1 than by hcatD. A peptidomimetic inhibitor (KPFSLΨLQF, where Ψ = –CH2–NH–), converted from such peptide sequence by reducing the scissor bond to the non‐cleavable methyleneamino (–CH2–NH–), exhibit an inhibition of PfPM1 with the dissociation constant (Ki) in nanomolar magnitude and a >5‐fold selectivity for PfPM1 over hcatD. In another study using a random decamer peptide library, Siripurkpong and colleagues showed that PfPM1 prefers accommodating leucine and serine at S1\' and S2\', respectively [122]. While the two studies agreed on the S1\' subsite specificity, the discrepancy at S2\' may arise from difference in enzyme preparation, peptide library composition, or catalytic conditions.
The naturally‐occurring PfPM2 is purified as a 36‐kDa mature enzyme, separated from PfPM1 by elution at a lower salt concentration [47]. As discussed in Section 3.1, the naturally‐occurring PfPM2 cleaves native hemoglobin at α33‐34 less efficiently than PfPM1 [47]; however, it digests acid‐denatured globin 3‐fold more efficiently than PfPM1 [113]. Similar to the naturally‐occurring PfPM1, PfPM2 is tightly inhibited by pepstatin with the Ki in sub‐nanomolar magnitude [113, 116].
Unlike the case of PfPM1, a recombinantly expressed truncated PfPM2 zymogen lacking the putative transmembrane motif fully converts itself to mature enzyme in acidic conditions [53]. PfPM2 generated from in vitro auto‐maturation retains a 2‐ or 12‐amino‐acid pro‐segment; though, the in vitro auto‐matured enzyme and its naturally‐occurring counterpart shares similar kinetic efficiencies in digesting hemoglobin‐derived substrates and inhibition by peptidomimetic compounds [113, 116]. Interestingly, PfPM2 can adopt the proper conformation from in vitro protein refolding such robustly that deleting part of (e.g. Δ112p–121p) or the entire pro‐segment costs no loss of its catalytic activity [123, 124].
Beyer and colleagues studied the subsite specificity of PfPM2 at S3 – S3\' using the combinatorial chemistry‐based peptide libraries discussed in Section 4.1.1 [125]. PfPM2 prefers accommodating bulky hydrophobic residues (e.g., norleucine, leucine, isoleucine and phenylalanine) in all studied subsites except for the S2\', where glutamine is the most favored. The peptide sequence comprising the most favored amino acid at each position, in the order of P3 – P3\', is nLInL*LQI (nL = norleucine). A peptidomimetic inhibitor (KPnLSnLΨLQI) designed using the same approach described above exhibits an inhibition of PfPM2 with the Ki at nanomolar magnitude and a >15‐fold selectivity for PfPM2 over hcatD. In two earlier studies, the catalytic activity of PfPM2 was assessed in cleaving five sets of chromogenic octapeptides; peptide substrates within a particular set differ in amino acids substituted in one of the P4, P3, P2, P2\' and P3\' positions [126, 127]. The results showed that peptides with large hydrophobic amino acids (e.g. phenylalanine and leucine) residing in P3, P2 and P3\' give rise to the highest kcat/Km values, consistent with the findings from the combinatorial peptide library study. In addition, Siripurkpong and colleagues reported that PfPM2 digests a library of random decameric peptides most efficiently when leucine is placed in the P1\' position and that the enzyme has comparable kinetic efficiencies when residues of different properties (e.g., serine, methionine, alanine and glutamine) are placed in the P2\' position [122], again consistent with the previous findings. Of note, an N‐terminal extension of peptide substrates to P6 enhances the kinetic efficiency of PfPM2, and yet C‐terminally extended peptides manifest no such effect [124]. The possible presence of a similar effect in other PM homologs is unclear yet.
HAP is a PM with the catalytic aspartic acid of the N‐terminus replaced by a histidine. Naturally‐occurring PfHAP, purified as a monomeric mature enzyme of ~37 kDa, cleaves hemoglobin‐derived substrates at an optimal pH 5.7 [48]. PfHAP shows nearly no cleavage of native hemoglobin, but is able to digest acid‐denatured globin and to hydrolyze α33‐34 in hemoglobin‐derived peptide substrates [48]. Nonetheless, PfHAP cleaves α33‐34 20‐fold less efficiently than PfPM1 and PfPM2 [48, 113]. The naturally‐occurring PfHAP can be fully inhibited by isovaleryl‐pepstatin (pepstatin A) at 1 μM and by the serine proteinase inhibitor phenylmethylsulfonyl fluoride (PMSF) at 1 mM [48].
Catalytically active PfHAP of the recombinant form was obtained using a similar strategy as the one applied to recombinant PfPM1 [128, 129]. The in vitro auto‐matured PfHAP retains 4 pro‐segment residues [128]. It exhibits an optimal catalytic activity at pH 5.2 and lowers kinetic efficiencies in cleaving hemoglobin‐derived peptides than its naturally‐occurring counterpart [128]. In addition, though pepstatin A at 1 μM completely inactivate the enzyme, PMSF at 1 mM inhibits enzyme activity by only 25% [128]. The apparent differences in enzymatic features between the naturally‐occurring PfHAP and the in vitro auto‐matured may be attributable to improper folding of the recombinant protein [128] and/or the inhibition effects of the pro‐segment [120].
A key question remains elusive is whether PfHAP functions as an aspartic or a serine proteinase. Based on results from computational modeling, some view PfHAP as a serine proteinase with a catalytic triad of H34, S37 and D214 [130], and others consider PfHAP an atypical aspartic proteinase with D214 performing catalysis and H34 stabilizing the intermediate enzyme species [131]. By conducting alanine mutation of these residues related to catalysis, Parr and colleagues showed that D214A renders PfHAP incapable of auto‐maturation, whereas H34A and S37A do not affect auto‐maturation, but lead to a lower kinetic efficiency in cleaving peptide substrates [132]. These findings support the role of D214 in enzyme catalysis, indicating that PfHAP is an atypical aspartic proteinase.
To the author\'s knowledge, no literatures have thus far reported the characteristics of naturally‐occurring PfPM4. The recombinantly expressed PfPM4 zymogen lacking the putative transmembrane motif conducts auto‐maturation under acidic conditions, resulting in a mature form retaining 12 pro‐segment residues [48]. This mature PfPM4 cleaves hemoglobin‐derived peptides at an optimal pH 5.4 [48]. PfPM4 digests native hemoglobin less efficiently than PfPM1 and PfPM2 and prefers cleaving acid‐denatured globin [48]. Similar to PfPM1 and PfPM2, but unlike PfHAP, PfPM4 is fully inhibited by pepstatin A at sub‐nanomolar magnitude, but not by inhibitors of other types of proteinases [48, 54].
Recombinant PM4s from the other three human malaria parasites and the rodent malarial parasite P. berghei were similarly produced and activated [54, 126, 133]. The subsite specificity at S3 – S3\' of the five PM4 orthologs (i.e., PfPM4, PoPM4, PvPM4, PmPM4 and PbPM4) was investigated using combinatorial peptide libraries [125, 133]. All five PM4s unanimously prefer accommodating phenylalanine or tyrosine at S1 and S1\', except that PbPM4 accommodates norleucine best at S1\'. At S3, bulky hydrophobic amino acids, such as leucine, norleucine and phenylalanine, are preferred by all five enzymes. At S3\', the acceptance of amino acids by the four human PM4s is broad with isoleucine accommodated best, whereas PbPM4 accommodates aromatic phenylalanine and tryptophan best. For S2 and S2\', all five PM4s seem to tolerate amino acids of different properties. Glutamic acid, serine and isoleucine are the most favored at S2; while for glutamine, isoleucine, glutamic acid and arginine, when accommodated in S2\', each leads to a considerable peptide cleavage. The peptide sequence comprising the most favored residue by each subsite, in the order of P3 – P3\', is IQF*YIL for PfPM4, is FEF*YFI for PoPM4, is LEF*FII for PvPM4, is FEF*FII for PmPM4, and is FEF*nLSW for PbPM4. Peptidomimetic inhibitors were designed using the same approach described in Section 4.1.1: KPVEFΨRQT for PfPM4, KPLEFΨFRV for PoPM4, KPLEFΨYRV for PvPM4, KPFELΨAWT for PmPM4, and KPYEFΨRQF for PbPM4. These compounds unanimously exhibit a selective inhibition of their respective PM4s over hcatD, and inhibit their respective PM4s with the Ki values at sub‐nanomolar to nanomolar magnitude, except for the one designed for PmPM4, which inhibits PmPM4 with the Ki at micromolar magnitude. Such a poor inhibition may be due to the incorporation in the P1\' position of an alanine that is poorly recognized by PmPM4, indicating the key role of the P1\' amino acid in determining the enzyme‐ligand interaction. In another two studies, the subsite specificity of the four human PM4s was analyzed at S3, S2, S2\' and S3\' using chromogenic octapeptides [54, 126]. The results showed that (1) hydrophobic amino acids (e.g., phenylalanine and isoleucine) are more favored at P3 than smaller hydrophobic, polar and charged amino acids, (2) hydrophobic amino acids are favored at P2, and (3) amino acids of different properties at P2\' and P3\' are well tolerated. These findings are consistent with the data obtained from the combinatorial peptide library study.
Thus far, enzymatic characterization of non‐FV PMs has been focused on the PM5 orthologs. PM5 (PfPM5) immunopurified from cultured P. falciparum cleaves PEXEL (RxLxQ/E/D)‐containing substrates at the C‐terminus of leucine at pH 5–7 [64], resembling the pH of the mammalian ER [134]. The PEXEL‐cleaving activity of PfPM5 is partially inhibited by pepstatin A and HIV‐1 PIs (i.e., lopinavir, nelfinavir, ritonavir and saquinavir) with the IC50 values in the high micromolar range [64, 104]. The presence of P3 R and P1 L is key to PfPM5‐catalyzed PEXEL cleavage in that mutations in these two positions (e.g., P3 R‐to‐A or K and P1 L‐to‐A or I) unanimously inhibit the cleavage, and abolish the export of PEXEL‐containing proteins to host erythrocytes; amino acids in the prime side positions also influence the efficiency of PEXEL cleavage and subsequent protein export [104, 105, 135]. PfPM5 also digests non‐canonical PEXEL motifs (e.g., RxLxxE) at the C‐terminus of P1 L, which in turn, triggers host‐targeted protein export [105]. Likewise, this PfPM5‐catalyzed non‐canonical PEXEL cleavage and subsequent protein export are blocked by a P3 R‐to‐A mutation [105]. Of note, though deleting neither the P1\' nor the P2\' amino acid affects enzyme cleavage, protein export efficiency is reduced by these prime side mutations [105]. Taken together, these findings highlight the essential role of P3 R and P1 L in modulating PfPM5‐mediated PEXEL cleavage and the importance of the prime side peptide sequence in directing host‐targeted protein export.
Two constructs of PfPM5 encoding a truncated zymogen (amino acids 37–521) and a mature enzyme (amino acids 84–521) have been recombinantly expressed in E. coli [136, 137]. Following in vitro protein refolding, both the zymogen and the mature enzyme exhibit catalytic activity in cleaving PEXEL‐containing peptides at an optimal pH 6.0–6.5 [136, 137]. Indeed, the pro‐segment of PfPM5 was shown to be non‐essential for guiding the proper folding of protein [137, 138]. Subsite specificity analysis of the recombinant mature PfPM5 on a peptide series of RxLxE at P2 and P1\' showed that when the polar serine is placed at P1\', the hydrophobic isoleucine is more favored at P2 than the charged glutamic acid and lysine; and vice versa, when isoleucine is placed at P2, serine is better accommodated at S1\' than glutamic acid and the hydrophobic valine [136]. Recombinant PfPM5, like the parasite‐expressed, can only be partially (<50%) inhibited by pepstatin A, nelfinavir or PMSF at 100 mM; however, its catalytic activity is almost fully blocked by Cu2+ or Hg2+ at the sub‐micromolar level [137]. Furthermore, the zymogen and mature form of PM5 (PvPM5‐Thai) from P. vivax Thailand isolates were recombinantly expressed; the purified PvPM5‐Thai exhibits similar enzymatic features as the recombinant PfPM5 does [139].
The enzymatic properties of PMs discussed in this section are summarized in Table 2.
PM | Expression pattern | Subcellular locationa | Enzymatic characteristics | |||
---|---|---|---|---|---|---|
pHb | Natural substrates | Subsite specificityd | Pepstatin A inhibition | |||
PfPM1 | Intra‐erythrocytic phase; merizoites; gametocytes | FV, TV | 5.0 | Hb | FSF*L(Q/S)F | <1 nM (Ki) |
PfPM2 | Intra‐erythrocytic phase; merizoites; gametocytes; oocysts; sporozoites | FV, TV | 4.7; ~6.8 | Hb; Host cytoskeletal proteins | nLInL*LQI | <1 nM (Ki) |
PfHAP | Intra‐erythrocytic phase; merizoites; gametocytes; sporozoites | FV, TV | 5.7 | Hb | n.d. | 1 μM (fully inhibition) |
PfPM4 | Intra‐erythrocytic phase; merizoites; gametocytes; oocysts; sporozoites | FV, TV | 4.5; ~6.6 | Hbc; Host cytoskeletal proteinsc | IQF*YIL | <1 nM (Ki) |
PvPM4 | Intra‐erythrocytic phase | FV, TV | 4.5 | Hbc | LEF*FII | <1 nM (Ki) |
PoPM4 | n.d. | FV, TV | 4.5 | Hbc | FEF*YFI | <1 nM (Ki) |
PmPM4 | n.d. | FV, TV | 4.5 | Hbc | FEF*FII | <1 nM (Ki) |
PbPM4 | n.d. | FV, TV | 5.0–5.5 | Hbc; Host cytoskeletal proteins | FEF*nLSW | <1 nM (Ki) |
PfPM5 | Intra‐erythrocytic phase; merizoites; gametocytes; sporozoites | ER/NE | 6.0–6.5 | PEXEL‐containing parasite proteins | RxL*x(Q/E/D); RxL*xxE | ~20–30 µM (IC50) |
Enzymatic properties of plasmepsins.
aThis column shows the subcellular locations of catalytically active, mature plasmepsins.
bThis column shows the optimal catalytic pH; for PfPM2 and PfPM4, digestion of host cytoskeletal proteins is carried out at near neutral pH.
cDigestion of these natural substrates were performed in vitro using recombinant plasmepsins.
dThis column shows the best amino acids accommodated at subsites in the order of P3 – P3′; * represents scissile bond between P1 and P1′; x represents any natural amino acid; nL = norleucine.
The establishment of the role of FV PMs in hemoglobin processing raised the question whether FV PMs can be targets of novel antimalarial drugs. Peptidomimetic compounds developed in the early stage (e.g., pepstatin A, SC‐50083, Ro40‐4388, and HIV‐1 PIs) bind FV PMs tightly and block growth of cultured parasites [46, 51, 140, 141], suggesting that inhibition of FV PMs is a promising antimalarial strategy. Numerous types of FV PM‐targeted compounds, synthetic or isolated from natural sources, have been assessed for the past two and a half decades based on criteria involving binding affinity and selectivity, inhibition potency to cultured parasite growth, and cytotoxicity to mammalian cell culture (for reviews, see for example [142, 143]). For example, certain hydroxyethylamine derivatives inhibit PfPM1, PfPM2 and PfPM4 in nanomolar magnitude, exhibit a >30‐fold binding selectivity over hcatD, and disrupt growth of cultured P. falciparum with IC50s in the low micromolar range [144, 145]. In a series of studies, several allophenylnorstatine‐based compounds were found to inhibit all four FV PfPMs in nanomolar magnitude, to block parasite growth with IC50s in the low micromolar range, and to have the TD50s (cytotoxicity) in high micromolar magnitude to rat skeletal myoblasts [146–148]. In addition, clinically used HIV‐1 PIs exhibit antimalarial activity on parasites in both the exo‐erythrocytic and the intra‐erythrocytic phases in the sub‐micromolar to low micromolar range [149–151], inhibit PfPM2 and PfPM4 at low micromolar magnitude, and have a >10‐fold selectivity over hcatD [141]. Interestingly, using affinity binding probes coupled to a FV PM inhibitor library, a hydroxyethyl‐based inhibitor was identified that inhibits all four FV PfPMs and the growth of cultured P. falciparum with IC50 at ~1 μM [152].
To assess whether FV PMs are appropriate drug targets, pfpm4, 1, 2 and pfhap were knocked out individually (i.e., Δpfpm4, Δpfpm1, Δpfpm2 and Δpfhap), in combination (e.g., Δpfpm4/1 and Δpfpm1/2/hap), or together as a whole (i.e., Δpfpm4/1/2/hap). Genetic ablation of any particular gene alters neither the mRNA transcription nor the protein expression of the other three paralogs over the course of the intra‐erythrocytic phase [153]. For hemoglobin metabolism, the Δpfpm4 strain, but not the Δpfpm1, Δpfpm2 or Δpfhap, shows a reduction in hemozoin accumulation in the FV compared to the parent line [154, 155]. Of note, genetic disruption of PM expression does affect the rate of parasite replication in that the Δpfpm4, Δpfpm1, Δpfpm2, Δpfpm4/1 and Δpfpm4/1/2/hap strains all exhibit a reduced growth rate in amino‐acid‐rich media compared to the parent line, and that when cultured in amino‐acid‐limited media, the Δpfhap strain also demonstrates a slower growth rate [153–157]. As for cell and subcellular organelle morphology, though no morphological abnormalities are apparent in the Δpfpm1 and Δpfhap strains, a portion of the Δpfpm2 shows enlarged mitochondria, and a portion of the Δpfpm4 exhibits a notable accumulation of electron‐dense, single‐membrane vesicles in the FV [154, 156]; in addition, ceroid‐like multilamellar bodies, and electron‐dense, single‐membrane vesicles are accumulated in the FV of the Δpfpm4/1/2/hap strain [155]. Taken together, genetic ablation of pfpms is not lethal to the parasite in cultured conditions despite apparent metabolic and pathological abnormalities, thus it seems that FV PMs may be dispensable for parasite survival; however, one cannot overlook the potential contribution of PbPM4 to the virulence of the parasite in infected mice (see discussion in Section 4.5). Understanding the pathological role of FV PMs in both cell‐based and animal models may lead to a better assessment of the feasibility of PM‐targeted drug development.
To better understand the relationship between enzyme inhibition and anti‐parasitic activity, the effects of known FV PM inhibitors on the growth of PM‐knockout parasites were investigated. When pepstatin A was administered to cultured parasite in the intra‐erythrocytic phase, growth of the Δpfpm1, Δpfpm2, Δpfhap and Δpfpm4/1 strains is even slightly less sensitive to the compound than that of the parent line, and yet growth of the FP‐2‐knockout strain is at least one order of magnitude more sensitive to pepstatin A [156, 157]. These findings indicate that the parasite may turn to other proteinases to maintain normal function when the activities of FV PMs are blocked. The effects of HIV‐1 PIs on in vitro PM inhibition and blockage of parasite growth have been well established [141, 158]. However, the Δpfpm1/2/hap and Δpfpm4/1/2/hap strains share a comparable sensitivity to five HIV‐1 PIs (i.e., atazanavir, lopinavir, indinavir, ritonavir and saquinavir) with the parent line [155], indicating that FV PMs may not be the target of these inhibitors in the parasite [141]. Such off‐target effects are rather common among developed PM inhibitors of distinct classes (e.g., C2‐symmetric 1,2‐dihydroxyethylenes [159], hydroxylethylamine transition‐state isosteres [145] and amidine‐containing diphenylureas [160]). The authentic targets of these inhibitors in the parasite have been under investigation [161].
Despite that FV PMs are not critical to parasite survival at the blood stage and that certain FV PM inhibitors exhibit their anti‐parasitic activities with an off‐target effect, it is still early to negate FV PM‐targeted drug design given our limited understanding of their functions and characteristics. The continuously identified novel functions of FV PMs plus their broad spatio‐temporal expression pattern over the course of the parasite life cycle are worthy of further investigation.
PM5 has been considered an ideal target for novel antimalarial drug design based on a series of findings: first, ablation of the gene encoding PM5 is lethal to cultured P. berghei [104], so is mutation of a catalytic aspartic acid of PM5 to cultured P. falciparum [64]; second, PM5 is evolutionarily conserved among Plasmodium spp. with no identified gene replication or functional redundancy [44]; third, PM5 shares a low amino acid sequence identity with human aspartic proteinases (e.g., 26% with mature hcatD, and 18% with mature human β‐secretase 1 (hBACE‐1)); and fourth, the expression profile of PM5 spans the entire life cycle of malaria parasites [44, 65, 66].
Two basic components were incorporated in the initial design of PM5 inhibitors: a PEXEL sequence, which provides a moderate fit of compounds to the active site of the enzyme, and a transition‐state peptidomimetic moiety, which gives rise to a tight interaction with the catalytic residues of proteinases. WEHI‐916, a statine‐based compound mimicking the non‐prime‐side RVL motif of the PEXEL, shows a strong inhibition (IC50 = ~20 nM) of PfPM5 and PvPM5, a much weaker inhibition of hcatD (IC50 = 25 µM), and a negligible inhibition of hBACE‐1 (IC50>100 µM) [162, 163]. Administration of WEHI‐916 to cultured P. falciparum blocks the PEXEL cleavage in a dose‐dependent manner, and impairs protein export to host erythrocytes [162]. Of particular interest, conditioned knockdown of pfpm5 enhances WEHI‐916‐mediated inhibition of PEXEL cleavage and the sensitivity of parasite growth to this compound; whereas overexpression of PfPM5 weakens the anti‐parasitic potency of WEHI‐916 [162]. These findings confirm that PM5 is the target of WEHI‐916 in the parasite. Though, WHEI‐916 has only a moderate potency (EC50 = 2.5 µM to the strain 3D7) in killing cultured P. falciparum, which may be attributed to its poor membrane permeability [162, 163]. To enhance the anti‐parasitic potency of WEHI‐916 while retaining its strong binding to PM5, the highly polar P3 arginine in WEHI‐916 was modified to its isostere L‐canavanine, and the N‐terminal sulfonamide was replaced by a carbamate [164, 165]. The resulting compound WEHI‐842 inhibits PfPM5 and PvPM5 more tightly (IC50 = 0.2–0.4 nM), and blocks the PEXEL cleavage and protein export more potently than WEHI‐916 [165]. Importantly, WEHI‐842 kills the chloroquine‐sensitive 3D7 strain and multiple chloroquine‐resistant P. falciparum strains with a potency (EC50 = 0.4 μM) one order of magnitude higher than that of WEHI‐916, and yet it exhibits a low cytotoxicity against human cells (TD50>50 μM) [165]. Taken together, WEHI‐842 represents a promising lead for developing PM5‐targeted antimalarial drugs.
Our limited knowledge on PMs 6–10 makes it difficult to assess the necessity and importance of developing drugs targeting these enzymes. However, the detection of these PMs in multiple stages of the parasite life cycle suggests that their role in malaria pathogenesis is non‐trivial. For future PM‐targeted drug development, the functions and characteristics of PMs 6‐10 warrant further study.
Malaria, one of the deadliest infectious diseases in history, still poses a serious socio‐economic problem at present. Malaria control has been effectively undertaken from multiple perspectives, including drug‐based disease prevention and treatment, intervention of malaria transmission by the mosquito vector, and usage of vaccine against malaria parasites. Though, the emergence and quick spread of drug‐resistant parasite strains urges us to identify new antimalarial drug targets. The subject of this review has focused on the aspartic proteinase PM family, the molecular entities deemed novel and promising targets of next‐generation antimalarial drugs.
Discussed here is our understanding of the PM family members on their biosynthesis, biological functions and characteristics for the past two and a half decades. Seven groups of PMs have thus far been identified from genome comparison of a series of Plasmodium spp. infecting rodents, birds, humans and non‐human primates. These PMs, unique in enzymatic feature and spatio‐temporal expression pattern, play multifaceted roles in the pathogenicity of the malaria parasite. Due to the seemingly dispensable role of FV PMs in parasite growth and survival, the focus of PM‐targeted drug development is shifting towards non‐FV PMs. Selective inhibitors of PM5 have been developed and shown strong inhibition potency to parasite growth.
On the other hand, our knowledge on PMs is still quite limited and much needs to be clarified and explored in the future studies. For example, what is the biological meaning of the presence of four FV PM paralogs in P. falciparum? What do the FV PM inhibitors authentically target to exert their anti‐parasitic activity? What are other possible roles of PM5 than host‐targeted protein export? What are the functions of PMs 6‐10, and can these enzymes be antimalarial drug targets? What is the likelihood that PMs are used as immunogens in active immunization and that antibodies directed against PMs are used in passive immunization to protect hosts from malaria parasite infection? Successful PM‐targeted drug development replies on a comprehensive understanding of this enzyme family.
ACTs | artemisinin‐based combination therapies |
ALLN | N-acetyl-Leu-Leu-norleucinal |
AN | artemisinin |
BFA | brefeldin A |
Chr. | chromosome |
CQ | chloroquine |
(k)Da | (kilo‐)dalton |
DDT | dichloro‐diphenyltrichloroethane |
E. coli | Escherichia coli |
E‐64 | L‐3‐carboxy‐2,3‐trans‐epoxypropionyl‐leucylamido(4‐guanidino)butane |
EC50 | half maximal effective concentration |
ECM | experimental cerebral malaria |
EM | electron microscopy |
ER | endoplasmic reticulum |
FP | falcipain |
FV | food vacuole |
GFP | green fluorescence protein |
HAP | Histo‐Aspartic Proteinase |
Hb | hemoglobin |
hBACE‐1 | human β‐secretase 1 |
hcatD | human cathepsin D |
HIV‐1 | human immunodeficiency virus type 1 |
IC50 | half maximal inhibitory concentration |
i.p. | intraperitoneally |
kb | kilo‐base |
kcat | turnover number |
kcat/Km | specificity constant |
Ki | dissociation/inhibition constant |
μM | micromolar |
mM | millimolar |
MS | mass spectrometry |
MW | molecular weight |
NE | nuclear envelope |
nL | norleucine |
nM | nanomolar |
P. | Plasmodium |
Pb | Plasmodium berghei |
PEXEL | Plasmodium export element |
Pf | Plasmodium falciparum |
PfEMP3 | P. falciparum erythrocyte membrane protein 3 |
Pg | Plasmodium gallinaceum |
pH | negative log of the hydrogen ion concentration |
pI | isoelectric point |
PIs | proteinase inhibitors |
PM | plasmepsin |
Pm | Plasmodium malariae |
PMSF | phenylmethylsulfonyl fluoride |
Po | Plasmodium ovale |
PPM | parasite plasma membrane |
PV | parasitophorous vacuole |
Pv | Plasmodium vivax |
PVM | parasitophorous vacuolar membrane |
SEC | size exclusion chromatography |
spp. | species pluralis |
TD50 | median toxic dose |
TV | transport vesicle |
This chapter deals with regulatory considerations related to radiopharmaceutical precursors within Europe. Outside, different aspects may apply, with the exception of certain harmonized documents. Radiopharmaceuticals are considered a safe class of medicinal products. Due to the small chemical quantities administered they are not expected to exhibit any measurable pharmacological effect [1]. However, since they are radioactive, the rules for minimizing the risk associated with the use of ionizing radiation to the patients and to the personnel must be observed. Depending on the chemical and physical properties, radiopharmaceuticals are used in major clinical areas for diagnostics and/or therapy [2]. As defined by the European Pharmacopeia (Ph. Eur.) general monograph (0125) radiopharmaceutical preparations or radiopharmaceuticals are medicinal products which, when ready for use, contain one or more radionuclides (radioactive isotopes) included for a medicinal purpose [3]. Importantly, they can also have the form of kits for radiopharmaceutical preparation, radionuclide generators and radionuclide precursors. For the latter it is understood that they are not used in patients as such but only after attaching them to the suitable pharmaceutical vector. Although according to Ph. Eur. monograph (0125) radionuclide precursor is any radionuclide produced for radiolabeling of another substance prior to administration, and according to Ph. Eur. general monograph (2902) the substance, which is used as such vector, is defined as a chemical precursor for radiopharmaceutical preparations [4], the term radiopharmaceutical precursor is used interchangeably for either of the two above defined precursors (Figure 1).
Radiopharmaceutical precursors according to Ph. Eur.
Given the complex nomenclature used in various regulations and guidance documents, the understanding of radiopharmaceutical precursor’s definition might be challenging. Depending on the context it could be interpreted as the substance which becomes a radiopharmaceutical after radiolabeling with a radionuclide of choice or a radionuclide which is used for radiolabeling of that substance. Therefore, the quality requirements and test methods specifications of precursors for use in preparation of theranostic radiopharmaceuticals can be discussed only in the light of current regulatory framework.
The preparation and use of radiopharmaceuticals are regulated by number of directives, regulations and rules. These documents may be classified with respect to the status of radiopharmaceutical preparation:
radiopharmaceuticals with marketing authorization (MA), regulated by:
radiopharmaceuticals to be used in clinical trials (CT), regulated by:
unlicensed radiopharmaceuticals extemporaneously (just before use) prepared, not for CT [12, 13].
Radiopharmaceuticals with marketing authorization (MA) meet the requirements of GMP Annex 3 (Manufacture of Radiopharmaceuticals) [8] and EMA Guideline on Radiopharmaceuticals [12]. For the small scale preparation of radiopharmaceuticals outside the marketing authorization the guide of the Pharmaceutical Inspection Convention and Pharmaceutical Inspection Co-operation Scheme (PIC/S) [14], the Guidelines on Good Radiopharmacy Practice (CRPP) issued by the Radiopharmacy Committee of European Association of Nuclear Medicine (EANM) [13] and the Chapter 5.19. Extemporaneous preparation of radiopharmaceutical preparations of the Ph. Eur. [15] are setting standards for good practices.
The translation of new radiopharmaceuticals from the preclinical stage into clinical trials requires appropriate quality assessment essential to ensure efficacy and safety of both drug substance and drug product [16, 17]. The specific regulatory framework for the use of radiopharmaceuticals in clinical trials has been established in Europe [9, 11, 18]. From the radiopharmaceutical development perspective, the essential step is the preparation of an Investigational Medicinal Product Dossier (IMPD). This document includes information related to the chemical and pharmaceutical quality of the drug substance and drug product, as well as non-clinical data related to pharmacology, pharmacokinetics, radiation dosimetry and toxicology [19]. IMPD contains two main sections related to the production and quality control of the radiopharmaceutical: the drug substance (the active pharmaceutical ingredient, or API) and the drug product.
An active pharmaceutical ingredient (API) is defined as any substance or mixture of substances intended to be used in the manufacture of a drug product. Such substances are intended to provide pharmacological activity or other direct effect in the diagnosis as well as treatment of disease or to affect the structure and function of the body. Radiopharmaceutical preparations are often formulated using predefined radionuclide precursors and chemical precursors. If such a preparation does not need a purification step prior to its administration to the patient, both precursors used in the synthesis are considered to be an API in the drug substance part of IMPD. This in particular applies to precursors for theranostic applications where a radiometal is used to radiolabel a vector targeting the receptor, e.g. peptide. On the other hand, chemical precursors used in the manufacture of radiopharmaceuticals, which are purified after the radiolabeling process, are defined as API starting material (e.g. chemical precursors for most F-18 and C-11 PET radiopharmaceuticals).
The manufacture of APIs should be carried out following general GMP requirements. In a GMP-based system, all processes are defined, systematically reviewed, and shown to be capable of consistently providing medicinal products of the required quality and complying with their specifications [20]. Written and approved protocols specifying critical steps, acceptance criteria, must be in place. Process validation is a crucial part of GMP, meaning that all critical steps of manufacturing processes as well as significant changes to these processes are validated. It should be noted that the requirements for validations differ depending whether marketing authorization, clinical trials or in-house preparation of radiopharmaceuticals are planned (see also Figure 2.) [21]. The qualification and validation aspects related to the small-scale “in house” preparation of radiopharmaceuticals are covered in the EANM guidance [22].
Requirements for chemical precursors used in preparation of radiopharmaceuticals depending on their regulatory status.
In the process of IMPD preparation the prime challenge is to establish quality specifications for radiopharmaceutical precursors. They are supposed to comprise a set of tests that are necessary to confirm identity, purity and strength of the drug substance. Issues under consideration are the definition of release criteria, analytical procedures and especially their validation. Main references to address these issues are the European Pharmacopeia and guidance provided by the International Conference on Harmonization (ICH). Ph. Eur. provides general requirements for quality control of radiopharmaceutical precursors, in addition, a number of monographs for individual radiopharmaceuticals and chemical precursors are available in the Ph. Eur.
The use of analytical methods described in the pharmacopeia allows to reduce the work load related to analytical method validation. This does not mean that a pharmacopeia method may be implemented without any preliminary testing and verification. As a minimum, the most critical parameters should be verified, depending on the intended method. If no pharmacopeia monograph exists, analytical methods need to be fully validated. As stated by the general reference document issued by ICH the objective of validation of an analytical procedure is to demonstrate that it is suitable for its intended purpose [23]. To validate an analytical method, the following characteristics may be considered: specificity, accuracy, linearity range, precision (repeatability and intermediate precision), limit of detection (LOD), limit of quantitation (LOQ) and robustness. Recently, recommendations for the validation of analytical methods which are specific for radiopharmaceuticals has been published by EANM [24].
Chemical precursors for radiopharmaceutical preparations, are non-radioactive substances obtained by chemical synthesis for combination with a radionuclide in contrast to precursors manufactured using substances of human or animal origin [4].
The quality specification for chemical precursors is built upon three elements: exact methods, test limits and selection of reference standard. Pharmacopeia monographs comprise a set of critical attributes categorized into three subdivisions: identity, tests (related substances, residual solvents, metal catalyst or metal reagent residues, microbial contamination, bacterial endotoxin) and assay of the active substance. To ensure the appropriate quality, reference substances (like primary standards e.g. Ph. Eur. Chemical Reference Substance, CRS, or Pharmaceutical Secondary Standard, PSS) are used as a standard in an assay, identifications, or purity test. CRS or PSS are often characterized and evaluated for its intended purpose by additional procedures other than those used in routine testing [25].
For in-house prepared radiopharmaceuticals the confirmation of the chemical identity and purity of the precursor are the minimum quality control required, in order to qualify the material for subsequent clinical radiolabeling. Additional testing may apply if necessary for the specific process. For example, testing of trace metals content may not be necessary when the material will be subsequently radiolabeled with halogens, but is absolutely critical when the material is intended for labelling with radiometals [26].
To bring a novel radiopharmaceutical into the clinic it is needed that specific quality requirements for the radiopharmaceutical precursor are established, the range of testing would depend on their status and/or intended use. It is worth noting that for Phase I clinical trials full analytical validation is not necessary (only method suitability should be confirmed) [21]. While analytical methods used to evaluate a batch of API for clinical trials may not yet be validated, they should be scientifically sound [27].
There are some specific requirements for the large-sized molecules (e.g. proteins or monoclonal antibodies) as radiopharmaceutical precursors [28]. Monoclonal antibodies are immunoglobulins (Ig) with a defined specificity derived from a monoclonal cell line. Their biological activities are characterized by a specific binding characteristic to a target ligand (e.g. antigen) and they may be generated by recombinant DNA (rDNA) technology, hybridoma technology, B lymphocyte immortalization or other technologies. Generally, when chemical precursors are manufactured using substances of human or animal origin, the requirements of Ph. Eur. chapter 5.1.7. Viral safety [29] and the general monograph Products with risk of transmitting agents of animal spongiform encephalopathies (1483) [30] apply.
Stability testing is part of the chemical precursor’s characterization. Detailed requirements for carrying out stability studies are included in the ICH guideline Q1A (R2) [31]. The purpose of stability testing is to provide evidence on how the quality of a substance varies with time under the influence of a variety of environmental factors such as temperature, humidity, and light, and to establish a re-test period and recommended storage conditions. Stability studies should be carried out on at least three batches and include testing parameters of the chemical precursor that are susceptible to changes during storage and may affect quality, safety and efficacy (e.g. chemical purity and/or assay). The validated analytical methods should be used in these tests. For method validation, it is essential to investigate degradation products and establish degradation pathways under stress conditions (e.g. heat, humidity, light, acid/base hydrolysis and oxidation).
Peptides are an emerging class of compounds that have application in theranostics of several diseases, mainly in cancer [32, 33, 34, 35, 36]. These chemical precursors are positioned between the classic small organic molecules and the high molecular weight biomolecules. The interest of the scientific community for peptide drugs has been continuously growing. Currently, more than 60 peptide-based pharmaceuticals are marketed, over 150 peptides are in active clinical trials and estimated 500 more are in preclinical stages of development [37, 38]. Chemically, peptides have poly-amino acids structure ranging from 3 to 100 amino acids (less than 10 kDa) linked by a peptide (amide, –CONH–) bond, and are lacking a tertiary structure. From the biological point of view, peptides are important regulators of growth and cellular functions in normal tissue and tumors. They can act as cytokines, chemokines, neurotransmitters, hormones and growth factors. Generally, they offer many advantages over other groups for radiopharmaceutical applications. Peptides demonstrate high receptor specificity and selectivity, as well as binding affinity, good tissue penetration and favorable pharmacokinetic profiles. Most of them is characterized by low toxicity and immunogenicity [39, 40]. Their compact size results in rapid targeting and blood clearance. As a consequence low nonspecific uptake in non-targeted tissues and high target-to-background ratios are achieved. Moreover, peptides can be easily chemically synthesized in high purity, modified and stabilized to obtain optimized pharmacokinetic parameters. These all attributes together with ability to attach different chelating agents, prosthetic group and availability of various bioconjugation techniques make peptides an important target platform for theranostic radiopharmaceuticals [41, 42].
Peptide-based radiopharmaceuticals were introduced into the clinic more than three decades ago [43]. Since that time, several theranostic radioligand platforms are used for diagnosis and peptide receptor radionuclide therapy (PRRT) of different cancer types. In this concept, peptide analogs directed against somatostatin receptors (SSTR) play a crucial role [44]. The most prominent example of the theranostic pair of radiolabeled peptides are DOTA-conjugated SSTR agonist DOTA-(D-Phe1, Tyr3, Thr8)-octreotate (DOTA-TATE) labeled with 68Ga and 177Lu (Figure 3). The marketing authorization of NETSPOT® ([68Ga]Ga-DOTATATE) in 2016 and LUTATHERA® ([177Lu]Lu-DOTATATE) in early 2018 [45] encouraged the research in this field to develop improved radiolabeled peptides targeting other receptor/antigen families, exemplified by the prostate specific membrane antigen (PSMA) [46], gastrin-releasing peptide receptor (GRPr) [47] and cholecystokinin-2 receptor (CCK2R) [48, 49]. Some of these peptides are currently under clinical investigation.
Structure of DOTA-TATE for labelling with theranostics pair of radionuclides: Gallium-68 (68Ga) and lutetium-177 (177Lu).
Peptides as precursors for radiopharmaceutical preparations, similarly to other chemical precursors, require adequate specification as a part of their quality assurance in order to demonstrate the safety and efficacy of the final radiopharmaceutical preparation. Currently, no individual pharmacopeia monograph of peptide used as radiopharmaceutical precursors is available. Thus, the quality specification should be established according to the general requirements [4, 50]. Herein, we provide an overview of recommended methods and test limits for the characterization of peptides. The set of analytical procedures that need to be considered is presented in Table 1. However, it should be noted that new analytical methods and modifications to existing ones are continuously being developed and should be utilized where appropriate.
The preliminary quality evaluation of peptides is based on the visual inspection of the appearance/color and solubility. This parameter is given only for information, it is not a requirement in a strict sense. If any of the characteristics change during storage, this change should be investigated and appropriate action taken. A typical description of peptide appearance is: white to almost white, freeze-dried powder and solubility is stated in water, ethanol and dilute solutions of acids and alkali [38, 51].
According to the ICH Q6A guideline [25] identification testing should allow to discriminate between compounds of closely related structure which are likely to be present (e.g. peptides with altered sequences or functional groups that may be formed during the synthesis). The identification test should include combination of different procedures (mostly two) and should be specific and unequivocal. Several techniques are currently in use for confirmation of peptide identity: HPLC-UV, nuclear magnetic resonance spectrometry (NMR), mass spectrometry (MS), infrared absorption spectrophotometry (IR), amino acid analysis (AAA) or peptide sequencing [51]. The method of choice is typically HPLC-UV based on retention time by comparison with reference standard, since the separation by RP-HPLC is often utilized and the method is widely available. UV detection of peptides is realized at 210–220 nm and 250–290 nm for aromatic side chains of phenylalanine, tyrosine and tryptophan. Identification solely by a chromatographic retention time is not regarded as specific and should be complemented by spectrometric techniques. The NMR spectroscopy is the method that allows to unequivocally define the structure of a peptide in the terms of amino acid composition, sequence and chirality. Identification by NMR spectrometry is usually limited to peptides comprising up to 15 amino acids and requires complex data interpretation. For this reason NMR technique is primarily replaced by mass spectroscopy (MS). This technique provides highly accurate molecular weight information on intact molecules, which is an advantage of MS for peptide identification. The peptide molecular mass is most commonly determined by using the electrospray ionization method (ESI), which occurs through the addition or removal of protons and appears as singly or doubly charged ions. As alternative for the more sophisticated spectroscopic methods, amino acid analysis (AAA) could be considered. This technique involves the hydrolysis of the peptide (usually in acidic conditions) to its individual amino acid residues, followed by chromatographic separation and detection/quantification. The method also enables the determination of the enantiomeric purity with the use of appropriate reference standards. However, this method may not be applicable to peptides containing unnatural amino acids and/or specific chelators. The NMR and AAA as well as peptide sequencing techniques are generally used for characterization of PSS.
In the two recently published papers the identity of DOTA-TATE has been confirmed using suitable instrumental techniques; Sikora et al. [52] confirmed the identity of DOTA-TATE using three different methods: MS, IR and HPLC. Similarly, in the work by Raheem at al [53] the final product was analyzed using high resolution mass spectrometry for identification and analytical HPLC for purification; it was detected via analytical HPLC at a retention time of 9.52 min and detected by HRMS-ESI (calc m/z for [(DOTA-TATE +2H)/2]+: 718.3028, found: 718.3046 with −0.1144 ppm error).
In our experience ESI-MS in positive ionization mode was used to confirmed whether the masses of ions at m/z 1435.6 ± 1.0 [M + H]+ and 718.3 ± 1.0 [M + 2H]2+correspond to the monoisotopic mass of peptide [M] as presented in Figure 4. DOTA-TATE PSS was used as reference in IR analysis. Also a gradient HPLC-UV (220 nm) served as identity test of DOTA-TATE by comparison with the reference standard (Rt ± 5.0%). The same HPLC method was used for determination of peptide purity and assay. The representative HPLC chromatograms of DOTA-TATE and DOTA-TATE PSS are given in Figure 5.
ESI-MS spectrum for DOTA-TATE.
HPLC-UV (220 nm) chromatograms of (I) DOTA-TATE Rt = 19.831 min and (II) DOTA-TATE PSS Rt = 19,936 min. HPLC method: Luna C18(2) column; Mobile phase - A: water with 0.1% TFA, B: Acetonitrile with 0.1% TFA; gradient profile – From 0 to 25 min: 0–50% B; flow - 0.8 mL/min, oven temperature - 30°C.
Peptides are usually chemically synthesized using solid-phase peptide synthesis (SPPS) [54]. In this multi-stage process, amino acids are linked to each other during individual coupling steps, thus constructing the desired peptide sequence. This occurs when the carboxylic end of the sequence is covalently attached to a solid support matrix. The complexity of the peptide production process results in a greater diversity of potential impurities. Heterogenicity of the impurity profile is observed even among peptides manufactured by the same synthetic route. The impurities can originate from raw materials, the manufacturing process, degradation or may be formed during storage. Although protecting groups, scavengers or activated functional groups are used to prevent undesired side-chain reactions the peptide manufacturing process leads to formation of closely related impurities. The most common impurities are products of racemization, deamidation, amino acid deletion or insertion, acetylation, oxidation, β-elimination, cyclization, reduction and incomplete deprotection [51]. The presence of related peptide impurities is typically determined using gradient reversed-phase HPLC method with UV detection, because of its selectivity, high sensitivity, low limit of detection, quantification and robustness. The developed HPLC method should allow sufficient separation of potential impurities from manufacturing process as well as degradation products. The acceptance criteria for related substances according to the Ph. Eur. General Monograph 2902 [4] are presented in Table 2.
Parameters | Typical methods | Typical acceptance criteria |
---|---|---|
Characters | ||
- Appearance/color | Visual inspection | White or almost white powder |
- Solubility | Visual inspection | Solubility in water, ethanol and dilute acid or alkali |
Identification | ||
- Active moiety | RP-HPLC-UV | Retention time versus reference |
MS or | Mass spectrum versus reference | |
NMR | NMR spectrum versus reference | |
IR | IR spectrum versus reference | |
AAA (GC) | AA: theoretical content ±20% | |
Purity tests | ||
- Related substances | HPLC-UV | Individual, unidentified: < 2.0% Total: ≤ 3.0% |
- Residual solvents | (Headspace) GC | Acetonitrile: ≤ 0.5% |
- Residual metals | AAS/ICP-AES/ICP-MS | Pt, Pd, Ir, Rh, Ru, Os, Mo, Ni, Cr, V, Pb, Hg, Cd, Tl: ≤ 0.01% |
- Residual reagents | HPLC-UV/IC/GC | Trifluoracetic acid: ≤ 1.0%* |
Counter-ion content | HPLC-UV/IC/GC | Acetic acid: target ±5% Trifluoracetic acid: target ±5% |
Water content | Karl-Fisher | ≤ 10.0% |
Assay (net peptide content) | RP-HPLC-UV or CHN | ≥ 75.0% |
Bioburden | TAMC plate count | ≤ 103 CFU/g for bulk ≤ 102 CFU per container |
TYMC plate count | ≤ 102 CFU/g for bulk ≤ 101 CFU per container | |
Bacterial endotoxins | Gel-clot | ≤ 100 IU/g for bulk ≤ 10 IU per container |
Summary of the recommended quality parameters for peptides used as radiopharmaceutical precursors.
The residual TFA content is determined when AcOH or HCl are used as counter-ions.
Reporting threshold | 0.2 per cent |
Identification threshold | 2.0 per cent |
Total unspecified impurities | Maximum 3.0 per cent |
Acceptance criteria for related substances [4].
Specific thresholds should be applied for impurities known to be unusually potent or to produce toxic or unacceptable pharmacological effects.
The presence of inorganic impurity should also be considered, in particular when radiolabeling of the peptide with radiometals is concerned. According to the Ph. Eur. general monograph (2902), the metal residues in peptides should be determined if the manufacturing process is known or suspected to lead to its presence, e.g. due to the use of specific metal catalyst (e.g. Pd) or metal containing reagents. The content for each of the following metals: Pt, Pd, Ir, Rh, Ru, Os, Mo, Ni, Cr, V, Pb, Hg, Cd, Tl in the peptide precursors are limited to 0.01%. The metal impurities are typically examined using atomic absorption spectrometry (AAS), inductively coupled plasma with atomic emission spectrometry detection (ICP-AES) or mass spectrometry detection (ICP-MS) techniques. Determination of residual metals in peptides can be crucial for precursors intended for radiometal labeling [55]. It has been proven that the presence of certain metals can significantly affect the labeling efficiency through competitive chelation.
In addition to related substances the residual solvents are required to be examined as impurities in peptide precursors. Residual solvents in pharmaceuticals are defined as organic volatile chemicals that are used in the manufacturing process. The solvents are not completely removed by practical manufacturing techniques (e.g. lyophilization process). General guidelines established by the ICH divide solvents into three classes [56]. The Class 1 solvents should not be used in the final step of the manufacturing process of chemical precursors, because of toxicity and environmental impact. The use of the Class 2 solvents should be limited due to potential toxicity and Class 3 solvents are regarded as posing a lower risk to human health. Based on the permitted daily exposure (PDE), Class 2 and 3 solvents are limited to 0.5%. Residual solvents are typically determined using chromatographic techniques such as gas chromatography (GC) coupled with static headspace sampling. Many solvents are usually used in the peptides synthetic process. However, as the advantage of the SPPS and lyophilization process, the most frequently detected solvent is only acetonitrile (Class 2 solvent), used as the component of the mobile phase in the final purification process by preparative HPLC.
Synthetic peptides usually contain counter-ions on protonated amino functional groups (N-terminus, Arg, His, Lys, etc.). The presence of counter-ions such as acetate, chloride or trifluoroacetate results from the peptide post synthetic cleavage and/or purification process. Depending on the peptide sequence they reduce the net peptide content by 5 to 25%, but are not considered as impurity. Radiopharmaceutical preparations for diagnostic or therapeutic purposes are based on the net peptide content and thus the amount of residual counter-ions needs to be assessed. To determine counter-ion amounts different method are being used such as: GC, HPLC-UV or ion chromatography (IC). Trifluoroacetic acid (TFA) determined by IC at the level of ca. 20% in DOTA-TATE [52], corresponded to three TFA molecules associated to single peptide molecule. TFA is commonly used as a chemical reagent to remove residual protecting groups during purification of peptides and also as a mobile-phase modifier in a reversed-phase chromatography. Therefore, when the counter-ion finally is AcOH or HCl, determination of the TFA residual content is mandatory.
In order demonstrate a lot-to-lot consistency the test for water content (residual moisture remaining from the lyophilization process) should be also performed. This parameter may affect the stability of the peptide. For residual water Karl-Fischer titration method as well as GC method with thermal conductivity detector (TCD) [57] are commonly used and water content is limited to max. 10%.
Generally, assay is defined as a net peptide content. The lyophilized peptide contains also water, counter ions and residual solvents. The net peptide content is referred to percentage of peptide material in the lyophilized peptide. According to ICH guideline Q6A, a specific stability-indicating procedure should be included in the specifications to determine the content of the drug substance. There are two main approaches to determine net peptide content. The first method is a relative assay against a well-defined chemical reference substance, performed using comparative chromatographic procedures. Usually the same RP-HPLC method is used for both assay, identification and related substances. The second approach is an absolute assays involving a functional group (e.g. AAA or titration methods) or a nitrogen content analysis. The nitrogen content is determined from the results of elemental analysis CHN. The calculation of the net peptide content is based on the relation between determined %N to the theoretical content in the peptide structure. For example, this method was used to DOTA-TATE assay determination. Peptide content calculated from elemental analysis was ca. 78.0%, which was in agreement with the generally accepted limit ≥75% [52].
The presence of microorganisms may affect the stability of drug substances due to their propensity to degrade/metabolize peptides. Microbiological examinations involve the bioburden control (Ph. Eur 2.6.12) and content of bacterial endotoxins (Ph Eur. 2.6.14). The microbial enumeration tests for total aerobic microbial counts (TAMC) and total yeast and mold counts (TYMC) must adhere to the acceptance criteria of 103 CFU/g and 102 CFU/g for bulk material and 102 CFU/g and 101 CFU per container for chemical precursors packed in single and multi-dose containers, respectively. Bacterial endotoxin can be determined by the gel-clot or photometric methods (turbidimetric and chromogenic techniques) and acceptance criteria are limited to a maximum 100 IU/g for bulk material or maximum 10 IU per container for chemical precursors packed in single-dose and multidose containers.
Radionuclide precursors are offered as solutions for radiolabeling with MA, they are also locally produced for the in-house preparation of radiopharmaceuticals. There is an ongoing debate whether radionuclide precursors always have to be considered as medicinal product, or also can be provided as a starting material [58]. Unlike for chemical precursors for radiopharmaceutical preparation, up to date there is no monograph in the Ph. Eur. that sets out general requirements for radionuclide precursors. This is due to the fact that the quality requirements for radionuclides used to obtain diagnostic and therapeutic preparations are highly varying and depend on the irradiation route and chemical processing involved, which mainly affect the parameters of radionuclide purity or specific activity.
However, there are several individual Ph. Eur. monographs for radionuclide precursors. Two of these concern radionuclide precursors used to prepare radiopharmaceuticals for therapeutic use. These are: Lutetium (177Lu) solution for radiolabelling (mon. 2798) [59] and Yttrium (90Y) chloride solution for radiolabelling (mon. 2803) [60]. There are also six monographs published for radionuclide precursors for preparation of diagnostic radiopharmaceuticals: Fluoride (18F) solution for radiolabelling (mon. 2390) [61], Sodium iodide (123I) solution for radiolabelling (mon. 2314) [62], Sodium iodide (131I) solution for radiolabelling (mon. 2121) [63], Indium (111In) chloride solution (mon. 1227) [64] and Gallium (68Ga) chloride solution for radiolabelling (mon. 2464) [65] and a newly published monograph for Gallium (68Ga) chloride (accelerator-produced) solution for radiolabelling (mon. 3109) [66].
Focusing attention on theranostic radiopharmaceuticals, herein the quality requirements only for metallic radionuclide precursors used in diagnostics and therapy are compared. Table 3 shows the exemplary quality requirements for radionuclide precursor for therapeutic use (177Lu) and a matching radionuclide precursor for diagnostic use (68Ga).
Lutetium (177Lu) solution for radiolabelling (Ph. Eur. 2798 [59]) | Gallium (68Ga) chloride solution for radiolabelling (Ph. Eur. 2464 [60]) |
---|---|
pH: 1.0 to 2.0, using a pH indicator strip R. | pH: maximum 2, using a pH indicator strip R. |
Lutetium: Inductively coupled plasma-atomic emission spectrometry (2.2.57), for determination of specific radioactivity. Copper: maximum 1.0 μg/GBq Iron: maximum 0.5 μg/GBq Lead: maximum 0.5 μg/GBq Zinc: maximum 1.0 μg/GBq | Iron: maximum 10 μg/GBq Zinc: maximum 10 μg/GBq |
RADIONUCLIDIC PURITY Lutetium-177: minimum 99.9 per cent of the total radioactivity. Gamma-ray spectrometry. Results: - the total radioactivity due to ytterbium-175 (impurity B) is not more than 0.1 per cent; – the total radioactivity due to lutetium-177 m (impurity A) is not more than 0.07 per cent; – the total radioactivity due to radionuclidic impurities other than A and B is not more than 0.01 per cent. | RADIONUCLIDIC PURITY Gallium-68: minimum 99.9 per cent of the total radioactivity. A. Gamma-ray spectrometry. Limit: peaks in the gamma-ray spectrum corresponding to photons with an energy different from 0.511 MeV, 1.077 MeV, 1.022 MeV and 1.883 MeV represent not more than 0.1 per cent of the total radioactivity. B. Germanium-68 and gamma-ray-emitting impurities. Gamma-ray spectrometry. Result: the total radioactivity due to germanium-68 and gamma-ray-emitting impurities is not more than 0.001 per cent. |
RADIOCHEMICAL PURITY [177Lu]lutetium(III) ion: minimum 99 per cent of the total radioactivity due to lutetium-177. | RADIOCHEMICAL PURITY [68Ga]gallium(III) ion: minimum 95 per cent of the total radioactivity due to gallium-68. |
Bacterial endotoxins (2.6.14): less than 175 IU/V, V being the maximum volume to be used for the preparation of a single patient dose, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins. | Bacterial endotoxins (2.6.14): less than 175 IU/V, V being the maximum volume to be used for the preparation of a single patient dose, if intended for use in the manufacture of parenteral preparations without a further appropriate procedure for the removal of bacterial endotoxins. |
Sterility: If intended for use in the manufacture of parenteral preparations without a further appropriate sterilization procedure, it complies with the test for sterility prescribed in the mon. 0125. The preparation may be released for use before completion of the test. |
Comparison of Ph. Eur. requirements for selected radionuclide precursors.
Comparing the requirements of these two monographs there are apparently large differences in numerical values seen, especially for metal ion content and radiochemical purity. However, when the radioactivity of these radionuclides (different for therapeutic or diagnostic use) is considered, there are basically no differences in quality requirements for both radionuclides. This can be demonstrated on the example of the DOTA-TATE preparations with 177Lu and 68Ga. For therapy 7.4 GBq of [177Lu]Lu-DOTA-TATE is used and this preparation contains ca. 0.2 mg of DOTA-TATE. Typical dose of [68Ga]Ga-DOTA-TATE is 200 MBq and the ligand content in the preparation should not exceed 0.05 mg. Therefore, when analyzing the limit of metallic impurities, e.g. Zn in the radionuclide precursor, similar values are obtained in both cases, i.e. maximum 37 ng and 40 ng per microgram of DOTA-TATE for lutetium-177 and gallium-68, respectively.
When the radiochemical purity is compared, the higher limit of permissible other forms of diagnostic radionuclide ([68Ga]gallium(III) ion: minimum 95%) than for the therapeutic radionuclide ([177Lu]Lutetium(III) ion: minimum 99%) does not result in a higher risk to the patient. Thus, 5% of other forms of a trivalent gallium-68 ion may result in the deposit of 10 MBq of this radionuclide in undesirable chemical form in non-target organs, while for 1% lutetium-177 it is as much as 74 MBq of uncontrolled chemical form. However, it must be noted that a stricter limit for the latter radionuclide is difficult to achieve due to the limitations of the analytical methods, which are characterized by an approximate 1% uncertainty of determination.
Bearing in mind that the differences in the profile of radionuclide contamination depend on the radionuclide production process [67], it is unlikely that uniform quality requirements for radionuclide precursors will be set in numerical terms. Each radionuclide precursor should be evaluated on a case-by-case basis, taking into account the physical characteristics of the radionuclide, its mode of irradiation and chemical processing as well as the envisaged clinical use and the dose planned for administration to the patient. This is clearly reflected in monographs referred in this Chapter. The monograph for 177Lu [59] applies to both the direct and indirect production routes of 177Lu in nuclear reactors and covers all quality aspects regardless the different specific radioactivity and impurity profiles. The decision is left to the producer of the final radiopharmaceutical preparation to use the appropriate solution for radiolabeling. However, the relevant information needs to be stated on the label. This is different in case of 68Ga, there are two different monographs specifying its quality requirements depending whether it’s generator [65] or accelerator produced [66]. One can expect that a similar individual approach applies to the future monographs for new theranostic radionuclides, for example 47Sc, which can be either accelerator or reactor produced [68].
Are the requirements for radiopharmaceutical precursors overregulated? With the development of new theranostic procedures involving radiopharmaceuticals, there is a need for proper qualitative evaluation of the final radiopharmaceutical preparation and both of the radiopharmaceutical precursors to ensure efficacy and safety of the treatment. An excellent example of the long pathway of a radiopharmaceutical, 111In-CP04, a peptide targeting the cholecystokinin-2 receptor, from the preclinical development over establishing the required pharmaceutical documentation to designing and submitting a clinical trial in patients with Medullary Thyroid Carcinoma, was recently presented [16]. All the quality aspects of CP04 as chemical precursor have been addressed in the IMPD in view of the quality and suitability of the radiolabeled preparation, 111In-CP04, in order to bring it to the clinic.
In this Chapter, the quality requirements applicable to radiopharmaceutical precursors in the context of their regulatory status in Europe were reviewed. EMA and Ph. Eur. provide public standards for manufacture and quality control of these precursors by establishing specifications and acceptance criteria. While in the case of radiopharmaceuticals with MA and CT regulations quite strictly define the quality and documentation requirements, such standards for in-house produced radiopharmaceuticals are still awaited.
.
",metaTitle:"Order Print Copies - Terms",metaDescription:".",metaKeywords:null,canonicalURL:"page/order-print-copies-terms/",contentRaw:'[{"type":"htmlEditorComponent","content":"Orders have to be prepaid in advance and before printing. We accept payment in GBP, EUR and USD. Payments can be made by bank transfer or cheque, by credit card (Visa, MasterCard, American Express, Discover Card) and PayPal worldwide online payments system. In accordance with the best security practice, we do not accept card orders via email.
\\n\\nThe combined printing and delivery times for orders vary from 12-20 business days, depending on the printed quantity and destination. This period does not include any customs clearance difficulties that may arise and that are beyond our control. Once your order has been printed and shipped, you will receive a confirmation email that includes your DHL tracking number. You can then track your order at www.dhl.com.
\\n\\nMy order has not arrived, what do I do?
\\n\\nIf you do not receive your order within 30 days, please contact us to inquire about the shipping status at orders@intechopen.com.
\\n\\nPOD products are non-returnable and non-refundable, except in the event of poor print quality or an error in quantity. If we delivered the item to you in error or the item is faulty, please contact us. Inspect your order carefully when it arrives. Any problems should be immediately reported to orders@intechopen.com.
\\n\\nTaxes: Residents of European Union countries need to add a Book Value-Added Tax of 5%. Institutions and companies, registered as VAT taxable entities in their own EU member state, will not pay VAT by providing us their VAT registration number. This is made possible by the EU reverse charge method.
\\n\\nCustoms: Shipping costs do not include any duties, taxes or clearing charges levied by the destination country. These charges are the responsibility of the customer and will vary from country to country.
\\n"}]'},components:[{type:"htmlEditorComponent",content:'Orders have to be prepaid in advance and before printing. We accept payment in GBP, EUR and USD. Payments can be made by bank transfer or cheque, by credit card (Visa, MasterCard, American Express, Discover Card) and PayPal worldwide online payments system. In accordance with the best security practice, we do not accept card orders via email.
\n\nThe combined printing and delivery times for orders vary from 12-20 business days, depending on the printed quantity and destination. This period does not include any customs clearance difficulties that may arise and that are beyond our control. Once your order has been printed and shipped, you will receive a confirmation email that includes your DHL tracking number. You can then track your order at www.dhl.com.
\n\nMy order has not arrived, what do I do?
\n\nIf you do not receive your order within 30 days, please contact us to inquire about the shipping status at orders@intechopen.com.
\n\nPOD products are non-returnable and non-refundable, except in the event of poor print quality or an error in quantity. If we delivered the item to you in error or the item is faulty, please contact us. Inspect your order carefully when it arrives. Any problems should be immediately reported to orders@intechopen.com.
\n\nTaxes: Residents of European Union countries need to add a Book Value-Added Tax of 5%. Institutions and companies, registered as VAT taxable entities in their own EU member state, will not pay VAT by providing us their VAT registration number. This is made possible by the EU reverse charge method.
\n\nCustoms: Shipping costs do not include any duties, taxes or clearing charges levied by the destination country. These charges are the responsibility of the customer and will vary from country to country.
\n'}]},successStories:{items:[]},authorsAndEditors:{filterParams:{sort:"featured,name"},profiles:[{id:"6700",title:"Dr.",name:"Abbass A.",middleName:null,surname:"Hashim",slug:"abbass-a.-hashim",fullName:"Abbass A. Hashim",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/6700/images/1864_n.jpg",biography:"Currently I am carrying out research in several areas of interest, mainly covering work on chemical and bio-sensors, semiconductor thin film device fabrication and characterisation.\nAt the moment I have very strong interest in radiation environmental pollution and bacteriology treatment. The teams of researchers are working very hard to bring novel results in this field. I am also a member of the team in charge for the supervision of Ph.D. students in the fields of development of silicon based planar waveguide sensor devices, study of inelastic electron tunnelling in planar tunnelling nanostructures for sensing applications and development of organotellurium(IV) compounds for semiconductor applications. I am a specialist in data analysis techniques and nanosurface structure. I have served as the editor for many books, been a member of the editorial board in science journals, have published many papers and hold many patents.",institutionString:null,institution:{name:"Sheffield Hallam University",country:{name:"United Kingdom"}}},{id:"54525",title:"Prof.",name:"Abdul Latif",middleName:null,surname:"Ahmad",slug:"abdul-latif-ahmad",fullName:"Abdul Latif Ahmad",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"20567",title:"Prof.",name:"Ado",middleName:null,surname:"Jorio",slug:"ado-jorio",fullName:"Ado Jorio",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Universidade Federal de Minas Gerais",country:{name:"Brazil"}}},{id:"47940",title:"Dr.",name:"Alberto",middleName:null,surname:"Mantovani",slug:"alberto-mantovani",fullName:"Alberto Mantovani",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"12392",title:"Mr.",name:"Alex",middleName:null,surname:"Lazinica",slug:"alex-lazinica",fullName:"Alex Lazinica",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/12392/images/7282_n.png",biography:"Alex Lazinica is the founder and CEO of IntechOpen. After obtaining a Master's degree in Mechanical Engineering, he continued his PhD studies in Robotics at the Vienna University of Technology. Here he worked as a robotic researcher with the university's Intelligent Manufacturing Systems Group as well as a guest researcher at various European universities, including the Swiss Federal Institute of Technology Lausanne (EPFL). During this time he published more than 20 scientific papers, gave presentations, served as a reviewer for major robotic journals and conferences and most importantly he co-founded and built the International Journal of Advanced Robotic Systems- world's first Open Access journal in the field of robotics. Starting this journal was a pivotal point in his career, since it was a pathway to founding IntechOpen - Open Access publisher focused on addressing academic researchers needs. Alex is a personification of IntechOpen key values being trusted, open and entrepreneurial. Today his focus is on defining the growth and development strategy for the company.",institutionString:null,institution:{name:"TU Wien",country:{name:"Austria"}}},{id:"19816",title:"Prof.",name:"Alexander",middleName:null,surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/19816/images/1607_n.jpg",biography:"Alexander I. Kokorin: born: 1947, Moscow; DSc., PhD; Principal Research Fellow (Research Professor) of Department of Kinetics and Catalysis, N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow.\r\nArea of research interests: physical chemistry of complex-organized molecular and nanosized systems, including polymer-metal complexes; the surface of doped oxide semiconductors. He is an expert in structural, absorptive, catalytic and photocatalytic properties, in structural organization and dynamic features of ionic liquids, in magnetic interactions between paramagnetic centers. The author or co-author of 3 books, over 200 articles and reviews in scientific journals and books. He is an actual member of the International EPR/ESR Society, European Society on Quantum Solar Energy Conversion, Moscow House of Scientists, of the Board of Moscow Physical Society.",institutionString:null,institution:{name:"Semenov Institute of Chemical Physics",country:{name:"Russia"}}},{id:"62389",title:"PhD.",name:"Ali Demir",middleName:null,surname:"Sezer",slug:"ali-demir-sezer",fullName:"Ali Demir Sezer",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/62389/images/3413_n.jpg",biography:"Dr. Ali Demir Sezer has a Ph.D. from Pharmaceutical Biotechnology at the Faculty of Pharmacy, University of Marmara (Turkey). He is the member of many Pharmaceutical Associations and acts as a reviewer of scientific journals and European projects under different research areas such as: drug delivery systems, nanotechnology and pharmaceutical biotechnology. Dr. Sezer is the author of many scientific publications in peer-reviewed journals and poster communications. Focus of his research activity is drug delivery, physico-chemical characterization and biological evaluation of biopolymers micro and nanoparticles as modified drug delivery system, and colloidal drug carriers (liposomes, nanoparticles etc.).",institutionString:null,institution:{name:"Marmara University",country:{name:"Turkey"}}},{id:"61051",title:"Prof.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"100762",title:"Prof.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"St David's Medical Center",country:{name:"United States of America"}}},{id:"107416",title:"Dr.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Texas Cardiac Arrhythmia",country:{name:"United States of America"}}},{id:"64434",title:"Dr.",name:"Angkoon",middleName:null,surname:"Phinyomark",slug:"angkoon-phinyomark",fullName:"Angkoon Phinyomark",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/64434/images/2619_n.jpg",biography:"My name is Angkoon Phinyomark. I received a B.Eng. degree in Computer Engineering with First Class Honors in 2008 from Prince of Songkla University, Songkhla, Thailand, where I received a Ph.D. degree in Electrical Engineering. My research interests are primarily in the area of biomedical signal processing and classification notably EMG (electromyography signal), EOG (electrooculography signal), and EEG (electroencephalography signal), image analysis notably breast cancer analysis and optical coherence tomography, and rehabilitation engineering. I became a student member of IEEE in 2008. During October 2011-March 2012, I had worked at School of Computer Science and Electronic Engineering, University of Essex, Colchester, Essex, United Kingdom. In addition, during a B.Eng. I had been a visiting research student at Faculty of Computer Science, University of Murcia, Murcia, Spain for three months.\n\nI have published over 40 papers during 5 years in refereed journals, books, and conference proceedings in the areas of electro-physiological signals processing and classification, notably EMG and EOG signals, fractal analysis, wavelet analysis, texture analysis, feature extraction and machine learning algorithms, and assistive and rehabilitative devices. I have several computer programming language certificates, i.e. Sun Certified Programmer for the Java 2 Platform 1.4 (SCJP), Microsoft Certified Professional Developer, Web Developer (MCPD), Microsoft Certified Technology Specialist, .NET Framework 2.0 Web (MCTS). I am a Reviewer for several refereed journals and international conferences, such as IEEE Transactions on Biomedical Engineering, IEEE Transactions on Industrial Electronics, Optic Letters, Measurement Science Review, and also a member of the International Advisory Committee for 2012 IEEE Business Engineering and Industrial Applications and 2012 IEEE Symposium on Business, Engineering and Industrial Applications.",institutionString:null,institution:{name:"Joseph Fourier University",country:{name:"France"}}},{id:"55578",title:"Dr.",name:"Antonio",middleName:null,surname:"Jurado-Navas",slug:"antonio-jurado-navas",fullName:"Antonio Jurado-Navas",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/55578/images/4574_n.png",biography:"Antonio Jurado-Navas received the M.S. degree (2002) and the Ph.D. degree (2009) in Telecommunication Engineering, both from the University of Málaga (Spain). He first worked as a consultant at Vodafone-Spain. From 2004 to 2011, he was a Research Assistant with the Communications Engineering Department at the University of Málaga. In 2011, he became an Assistant Professor in the same department. From 2012 to 2015, he was with Ericsson Spain, where he was working on geo-location\ntools for third generation mobile networks. Since 2015, he is a Marie-Curie fellow at the Denmark Technical University. His current research interests include the areas of mobile communication systems and channel modeling in addition to atmospheric optical communications, adaptive optics and statistics",institutionString:null,institution:{name:"University of Malaga",country:{name:"Spain"}}}],filtersByRegion:[{group:"region",caption:"North America",value:1,count:5775},{group:"region",caption:"Middle and South America",value:2,count:5238},{group:"region",caption:"Africa",value:3,count:1721},{group:"region",caption:"Asia",value:4,count:10409},{group:"region",caption:"Australia and Oceania",value:5,count:897},{group:"region",caption:"Europe",value:6,count:15805}],offset:12,limit:12,total:118374},chapterEmbeded:{data:{}},editorApplication:{success:null,errors:{}},ofsBooks:{filterParams:{sort:"dateendthirdsteppublish"},books:[],filtersByTopic:[{group:"topic",caption:"Agricultural and Biological Sciences",value:5,count:18},{group:"topic",caption:"Biochemistry, Genetics and Molecular Biology",value:6,count:5},{group:"topic",caption:"Business, Management and Economics",value:7,count:2},{group:"topic",caption:"Chemistry",value:8,count:8},{group:"topic",caption:"Computer and Information Science",value:9,count:5},{group:"topic",caption:"Earth and Planetary Sciences",value:10,count:7},{group:"topic",caption:"Engineering",value:11,count:19},{group:"topic",caption:"Environmental Sciences",value:12,count:2},{group:"topic",caption:"Immunology and Microbiology",value:13,count:3},{group:"topic",caption:"Materials Science",value:14,count:5},{group:"topic",caption:"Mathematics",value:15,count:1},{group:"topic",caption:"Medicine",value:16,count:24},{group:"topic",caption:"Neuroscience",value:18,count:2},{group:"topic",caption:"Pharmacology, Toxicology and Pharmaceutical Science",value:19,count:3},{group:"topic",caption:"Physics",value:20,count:3},{group:"topic",caption:"Psychology",value:21,count:4},{group:"topic",caption:"Robotics",value:22,count:1},{group:"topic",caption:"Social Sciences",value:23,count:3},{group:"topic",caption:"Technology",value:24,count:1},{group:"topic",caption:"Veterinary Medicine and Science",value:25,count:1}],offset:0,limit:12,total:null},popularBooks:{featuredBooks:[{type:"book",id:"9521",title:"Antimicrobial Resistance",subtitle:"A One Health Perspective",isOpenForSubmission:!1,hash:"30949e78832e1afba5606634b52056ab",slug:"antimicrobial-resistance-a-one-health-perspective",bookSignature:"Mihai Mareș, Swee Hua Erin Lim, Kok-Song Lai and Romeo-Teodor Cristina",coverURL:"https://cdn.intechopen.com/books/images_new/9521.jpg",editors:[{id:"88785",title:"Prof.",name:"Mihai",middleName:null,surname:"Mares",slug:"mihai-mares",fullName:"Mihai Mares"}],equalEditorOne:{id:"190224",title:"Dr.",name:"Swee Hua Erin",middleName:null,surname:"Lim",slug:"swee-hua-erin-lim",fullName:"Swee Hua Erin Lim",profilePictureURL:"https://mts.intechopen.com/storage/users/190224/images/system/190224.png",biography:"Dr. Erin Lim is presently working as an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates and is affiliated as an Associate Professor to Perdana University-Royal College of Surgeons in Ireland, Selangor, Malaysia. She obtained her Ph.D. from Universiti Putra Malaysia in 2010 with a National Science Fellowship awarded from the Ministry of Science, Technology and Innovation Malaysia and has been actively involved in research ever since. Her main research interests include analysis of carriage and transmission of multidrug resistant bacteria in non-conventional settings, besides an interest in natural products for antimicrobial testing. She is heavily involved in the elucidation of mechanisms of reversal of resistance in bacteria in addition to investigating the immunological analyses of diseases, development of vaccination and treatment models in animals. She hopes her work will support the discovery of therapeutics in the clinical setting and assist in the combat against the burden of antibiotic resistance.",institutionString:"Abu Dhabi Women’s College",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Perdana University",institutionURL:null,country:{name:"Malaysia"}}},equalEditorTwo:{id:"221544",title:"Dr.",name:"Kok-Song",middleName:null,surname:"Lai",slug:"kok-song-lai",fullName:"Kok-Song Lai",profilePictureURL:"https://mts.intechopen.com/storage/users/221544/images/system/221544.jpeg",biography:"Dr. Lai Kok Song is an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates. He obtained his Ph.D. in Biological Sciences from Nara Institute of Science and Technology, Japan in 2012. Prior to his academic appointment, Dr. Lai worked as a Senior Scientist at the Ministry of Science, Technology and Innovation, Malaysia. His current research areas include antimicrobial resistance and plant-pathogen interaction. His particular interest lies in the study of the antimicrobial mechanism via membrane disruption of essential oils against multi-drug resistance bacteria through various biochemical, molecular and proteomic approaches. Ultimately, he hopes to uncover and determine novel biomarkers related to antibiotic resistance that can be developed into new therapeutic strategies.",institutionString:"Higher Colleges of Technology",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"8",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Higher Colleges of Technology",institutionURL:null,country:{name:"United Arab Emirates"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10020",title:"Operations Management",subtitle:"Emerging Trend in the Digital Era",isOpenForSubmission:!1,hash:"526f0dbdc7e4d85b82ce8383ab894b4c",slug:"operations-management-emerging-trend-in-the-digital-era",bookSignature:"Antonella Petrillo, Fabio De Felice, Germano Lambert-Torres and Erik Bonaldi",coverURL:"https://cdn.intechopen.com/books/images_new/10020.jpg",editors:[{id:"181603",title:"Dr.",name:"Antonella",middleName:null,surname:"Petrillo",slug:"antonella-petrillo",fullName:"Antonella Petrillo"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9560",title:"Creativity",subtitle:"A Force to Innovation",isOpenForSubmission:!1,hash:"58f740bc17807d5d88d647c525857b11",slug:"creativity-a-force-to-innovation",bookSignature:"Pooja Jain",coverURL:"https://cdn.intechopen.com/books/images_new/9560.jpg",editors:[{id:"316765",title:"Dr.",name:"Pooja",middleName:null,surname:"Jain",slug:"pooja-jain",fullName:"Pooja Jain"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10192",title:"Background and Management of Muscular Atrophy",subtitle:null,isOpenForSubmission:!1,hash:"eca24028d89912b5efea56e179dff089",slug:"background-and-management-of-muscular-atrophy",bookSignature:"Julianna Cseri",coverURL:"https://cdn.intechopen.com/books/images_new/10192.jpg",editors:[{id:"135579",title:"Dr.",name:"Julianna",middleName:null,surname:"Cseri",slug:"julianna-cseri",fullName:"Julianna Cseri"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9243",title:"Coastal Environments",subtitle:null,isOpenForSubmission:!1,hash:"8e05e5f631e935eef366980f2e28295d",slug:"coastal-environments",bookSignature:"Yuanzhi Zhang and X. San Liang",coverURL:"https://cdn.intechopen.com/books/images_new/9243.jpg",editors:[{id:"77597",title:"Prof.",name:"Yuanzhi",middleName:null,surname:"Zhang",slug:"yuanzhi-zhang",fullName:"Yuanzhi Zhang"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9385",title:"Renewable Energy",subtitle:"Technologies and Applications",isOpenForSubmission:!1,hash:"a6b446d19166f17f313008e6c056f3d8",slug:"renewable-energy-technologies-and-applications",bookSignature:"Tolga Taner, Archana Tiwari and Taha Selim Ustun",coverURL:"https://cdn.intechopen.com/books/images_new/9385.jpg",editors:[{id:"197240",title:"Associate Prof.",name:"Tolga",middleName:null,surname:"Taner",slug:"tolga-taner",fullName:"Tolga Taner"}],equalEditorOne:{id:"186791",title:"Dr.",name:"Archana",middleName:null,surname:"Tiwari",slug:"archana-tiwari",fullName:"Archana Tiwari",profilePictureURL:"https://mts.intechopen.com/storage/users/186791/images/system/186791.jpg",biography:"Dr. Archana Tiwari is Associate Professor at Amity University, India. Her research interests include renewable sources of energy from microalgae and further utilizing the residual biomass for the generation of value-added products, bioremediation through microalgae and microbial consortium, antioxidative enzymes and stress, and nutraceuticals from microalgae. She has been working on algal biotechnology for the last two decades. She has published her research in many international journals and has authored many books and chapters with renowned publishing houses. She has also delivered talks as an invited speaker at many national and international conferences. Dr. Tiwari is the recipient of several awards including Researcher of the Year and Distinguished Scientist.",institutionString:"Amity University",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"1",institution:{name:"Amity University",institutionURL:null,country:{name:"India"}}},equalEditorTwo:{id:"197609",title:"Prof.",name:"Taha Selim",middleName:null,surname:"Ustun",slug:"taha-selim-ustun",fullName:"Taha Selim Ustun",profilePictureURL:"https://mts.intechopen.com/storage/users/197609/images/system/197609.jpeg",biography:"Dr. Taha Selim Ustun received a Ph.D. in Electrical Engineering from Victoria University, Melbourne, Australia. He is a researcher with the Fukushima Renewable Energy Institute, AIST (FREA), where he leads the Smart Grid Cybersecurity Laboratory. Prior to that, he was a faculty member with the School of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, USA. His current research interests include power systems protection, communication in power networks, distributed generation, microgrids, electric vehicle integration, and cybersecurity in smart grids. He serves on the editorial boards of IEEE Access, IEEE Transactions on Industrial Informatics, Energies, Electronics, Electricity, World Electric Vehicle and Information journals. Dr. Ustun is a member of the IEEE 2004 and 2800, IEC Renewable Energy Management WG 8, and IEC TC 57 WG17. He has been invited to run specialist courses in Africa, India, and China. He has delivered talks for the Qatar Foundation, the World Energy Council, the Waterloo Global Science Initiative, and the European Union Energy Initiative (EUEI). His research has attracted funding from prestigious programs in Japan, Australia, the European Union, and North America.",institutionString:"Fukushima Renewable Energy Institute, AIST (FREA)",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"1",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"National Institute of Advanced Industrial Science and Technology",institutionURL:null,country:{name:"Japan"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8985",title:"Natural Resources Management and Biological Sciences",subtitle:null,isOpenForSubmission:!1,hash:"5c2e219a6c021a40b5a20c041dea88c4",slug:"natural-resources-management-and-biological-sciences",bookSignature:"Edward R. Rhodes and Humood Naser",coverURL:"https://cdn.intechopen.com/books/images_new/8985.jpg",editors:[{id:"280886",title:"Prof.",name:"Edward R",middleName:null,surname:"Rhodes",slug:"edward-r-rhodes",fullName:"Edward R Rhodes"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10065",title:"Wavelet Theory",subtitle:null,isOpenForSubmission:!1,hash:"d8868e332169597ba2182d9b004d60de",slug:"wavelet-theory",bookSignature:"Somayeh Mohammady",coverURL:"https://cdn.intechopen.com/books/images_new/10065.jpg",editors:[{id:"109280",title:"Dr.",name:"Somayeh",middleName:null,surname:"Mohammady",slug:"somayeh-mohammady",fullName:"Somayeh Mohammady"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9644",title:"Glaciers and the Polar Environment",subtitle:null,isOpenForSubmission:!1,hash:"e8cfdc161794e3753ced54e6ff30873b",slug:"glaciers-and-the-polar-environment",bookSignature:"Masaki Kanao, Danilo Godone and Niccolò Dematteis",coverURL:"https://cdn.intechopen.com/books/images_new/9644.jpg",editors:[{id:"51959",title:"Dr.",name:"Masaki",middleName:null,surname:"Kanao",slug:"masaki-kanao",fullName:"Masaki Kanao"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9550",title:"Entrepreneurship",subtitle:"Contemporary Issues",isOpenForSubmission:!1,hash:"9b4ac1ee5b743abf6f88495452b1e5e7",slug:"entrepreneurship-contemporary-issues",bookSignature:"Mladen Turuk",coverURL:"https://cdn.intechopen.com/books/images_new/9550.jpg",editors:[{id:"319755",title:"Prof.",name:"Mladen",middleName:null,surname:"Turuk",slug:"mladen-turuk",fullName:"Mladen Turuk"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9027",title:"Human Blood Group Systems and Haemoglobinopathies",subtitle:null,isOpenForSubmission:!1,hash:"d00d8e40b11cfb2547d1122866531c7e",slug:"human-blood-group-systems-and-haemoglobinopathies",bookSignature:"Osaro Erhabor and Anjana Munshi",coverURL:"https://cdn.intechopen.com/books/images_new/9027.jpg",editors:[{id:"35140",title:null,name:"Osaro",middleName:null,surname:"Erhabor",slug:"osaro-erhabor",fullName:"Osaro Erhabor"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8558",title:"Aerodynamics",subtitle:null,isOpenForSubmission:!1,hash:"db7263fc198dfb539073ba0260a7f1aa",slug:"aerodynamics",bookSignature:"Mofid Gorji-Bandpy and Aly-Mousaad Aly",coverURL:"https://cdn.intechopen.com/books/images_new/8558.jpg",editors:[{id:"35542",title:"Prof.",name:"Mofid",middleName:null,surname:"Gorji-Bandpy",slug:"mofid-gorji-bandpy",fullName:"Mofid Gorji-Bandpy"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:12,limit:12,total:5247},hotBookTopics:{hotBooks:[],offset:0,limit:12,total:null},publish:{},publishingProposal:{success:null,errors:{}},books:{featuredBooks:[{type:"book",id:"9521",title:"Antimicrobial Resistance",subtitle:"A One Health Perspective",isOpenForSubmission:!1,hash:"30949e78832e1afba5606634b52056ab",slug:"antimicrobial-resistance-a-one-health-perspective",bookSignature:"Mihai Mareș, Swee Hua Erin Lim, Kok-Song Lai and Romeo-Teodor Cristina",coverURL:"https://cdn.intechopen.com/books/images_new/9521.jpg",editors:[{id:"88785",title:"Prof.",name:"Mihai",middleName:null,surname:"Mares",slug:"mihai-mares",fullName:"Mihai Mares"}],equalEditorOne:{id:"190224",title:"Dr.",name:"Swee Hua Erin",middleName:null,surname:"Lim",slug:"swee-hua-erin-lim",fullName:"Swee Hua Erin Lim",profilePictureURL:"https://mts.intechopen.com/storage/users/190224/images/system/190224.png",biography:"Dr. Erin Lim is presently working as an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates and is affiliated as an Associate Professor to Perdana University-Royal College of Surgeons in Ireland, Selangor, Malaysia. She obtained her Ph.D. from Universiti Putra Malaysia in 2010 with a National Science Fellowship awarded from the Ministry of Science, Technology and Innovation Malaysia and has been actively involved in research ever since. Her main research interests include analysis of carriage and transmission of multidrug resistant bacteria in non-conventional settings, besides an interest in natural products for antimicrobial testing. She is heavily involved in the elucidation of mechanisms of reversal of resistance in bacteria in addition to investigating the immunological analyses of diseases, development of vaccination and treatment models in animals. She hopes her work will support the discovery of therapeutics in the clinical setting and assist in the combat against the burden of antibiotic resistance.",institutionString:"Abu Dhabi Women’s College",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Perdana University",institutionURL:null,country:{name:"Malaysia"}}},equalEditorTwo:{id:"221544",title:"Dr.",name:"Kok-Song",middleName:null,surname:"Lai",slug:"kok-song-lai",fullName:"Kok-Song Lai",profilePictureURL:"https://mts.intechopen.com/storage/users/221544/images/system/221544.jpeg",biography:"Dr. Lai Kok Song is an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates. He obtained his Ph.D. in Biological Sciences from Nara Institute of Science and Technology, Japan in 2012. Prior to his academic appointment, Dr. Lai worked as a Senior Scientist at the Ministry of Science, Technology and Innovation, Malaysia. His current research areas include antimicrobial resistance and plant-pathogen interaction. His particular interest lies in the study of the antimicrobial mechanism via membrane disruption of essential oils against multi-drug resistance bacteria through various biochemical, molecular and proteomic approaches. Ultimately, he hopes to uncover and determine novel biomarkers related to antibiotic resistance that can be developed into new therapeutic strategies.",institutionString:"Higher Colleges of Technology",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"8",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Higher Colleges of Technology",institutionURL:null,country:{name:"United Arab Emirates"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10020",title:"Operations Management",subtitle:"Emerging Trend in the Digital Era",isOpenForSubmission:!1,hash:"526f0dbdc7e4d85b82ce8383ab894b4c",slug:"operations-management-emerging-trend-in-the-digital-era",bookSignature:"Antonella Petrillo, Fabio De Felice, Germano Lambert-Torres and Erik Bonaldi",coverURL:"https://cdn.intechopen.com/books/images_new/10020.jpg",editors:[{id:"181603",title:"Dr.",name:"Antonella",middleName:null,surname:"Petrillo",slug:"antonella-petrillo",fullName:"Antonella Petrillo"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9560",title:"Creativity",subtitle:"A Force to Innovation",isOpenForSubmission:!1,hash:"58f740bc17807d5d88d647c525857b11",slug:"creativity-a-force-to-innovation",bookSignature:"Pooja Jain",coverURL:"https://cdn.intechopen.com/books/images_new/9560.jpg",editors:[{id:"316765",title:"Dr.",name:"Pooja",middleName:null,surname:"Jain",slug:"pooja-jain",fullName:"Pooja Jain"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10192",title:"Background and Management of Muscular Atrophy",subtitle:null,isOpenForSubmission:!1,hash:"eca24028d89912b5efea56e179dff089",slug:"background-and-management-of-muscular-atrophy",bookSignature:"Julianna Cseri",coverURL:"https://cdn.intechopen.com/books/images_new/10192.jpg",editors:[{id:"135579",title:"Dr.",name:"Julianna",middleName:null,surname:"Cseri",slug:"julianna-cseri",fullName:"Julianna Cseri"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9243",title:"Coastal Environments",subtitle:null,isOpenForSubmission:!1,hash:"8e05e5f631e935eef366980f2e28295d",slug:"coastal-environments",bookSignature:"Yuanzhi Zhang and X. San Liang",coverURL:"https://cdn.intechopen.com/books/images_new/9243.jpg",editors:[{id:"77597",title:"Prof.",name:"Yuanzhi",middleName:null,surname:"Zhang",slug:"yuanzhi-zhang",fullName:"Yuanzhi Zhang"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9385",title:"Renewable Energy",subtitle:"Technologies and Applications",isOpenForSubmission:!1,hash:"a6b446d19166f17f313008e6c056f3d8",slug:"renewable-energy-technologies-and-applications",bookSignature:"Tolga Taner, Archana Tiwari and Taha Selim Ustun",coverURL:"https://cdn.intechopen.com/books/images_new/9385.jpg",editors:[{id:"197240",title:"Associate Prof.",name:"Tolga",middleName:null,surname:"Taner",slug:"tolga-taner",fullName:"Tolga Taner"}],equalEditorOne:{id:"186791",title:"Dr.",name:"Archana",middleName:null,surname:"Tiwari",slug:"archana-tiwari",fullName:"Archana Tiwari",profilePictureURL:"https://mts.intechopen.com/storage/users/186791/images/system/186791.jpg",biography:"Dr. Archana Tiwari is Associate Professor at Amity University, India. Her research interests include renewable sources of energy from microalgae and further utilizing the residual biomass for the generation of value-added products, bioremediation through microalgae and microbial consortium, antioxidative enzymes and stress, and nutraceuticals from microalgae. She has been working on algal biotechnology for the last two decades. She has published her research in many international journals and has authored many books and chapters with renowned publishing houses. She has also delivered talks as an invited speaker at many national and international conferences. Dr. Tiwari is the recipient of several awards including Researcher of the Year and Distinguished Scientist.",institutionString:"Amity University",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"1",institution:{name:"Amity University",institutionURL:null,country:{name:"India"}}},equalEditorTwo:{id:"197609",title:"Prof.",name:"Taha Selim",middleName:null,surname:"Ustun",slug:"taha-selim-ustun",fullName:"Taha Selim Ustun",profilePictureURL:"https://mts.intechopen.com/storage/users/197609/images/system/197609.jpeg",biography:"Dr. Taha Selim Ustun received a Ph.D. in Electrical Engineering from Victoria University, Melbourne, Australia. He is a researcher with the Fukushima Renewable Energy Institute, AIST (FREA), where he leads the Smart Grid Cybersecurity Laboratory. Prior to that, he was a faculty member with the School of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, USA. His current research interests include power systems protection, communication in power networks, distributed generation, microgrids, electric vehicle integration, and cybersecurity in smart grids. He serves on the editorial boards of IEEE Access, IEEE Transactions on Industrial Informatics, Energies, Electronics, Electricity, World Electric Vehicle and Information journals. Dr. Ustun is a member of the IEEE 2004 and 2800, IEC Renewable Energy Management WG 8, and IEC TC 57 WG17. He has been invited to run specialist courses in Africa, India, and China. He has delivered talks for the Qatar Foundation, the World Energy Council, the Waterloo Global Science Initiative, and the European Union Energy Initiative (EUEI). His research has attracted funding from prestigious programs in Japan, Australia, the European Union, and North America.",institutionString:"Fukushima Renewable Energy Institute, AIST (FREA)",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"1",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"National Institute of Advanced Industrial Science and Technology",institutionURL:null,country:{name:"Japan"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8985",title:"Natural Resources Management and Biological Sciences",subtitle:null,isOpenForSubmission:!1,hash:"5c2e219a6c021a40b5a20c041dea88c4",slug:"natural-resources-management-and-biological-sciences",bookSignature:"Edward R. Rhodes and Humood Naser",coverURL:"https://cdn.intechopen.com/books/images_new/8985.jpg",editors:[{id:"280886",title:"Prof.",name:"Edward R",middleName:null,surname:"Rhodes",slug:"edward-r-rhodes",fullName:"Edward R Rhodes"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"10065",title:"Wavelet Theory",subtitle:null,isOpenForSubmission:!1,hash:"d8868e332169597ba2182d9b004d60de",slug:"wavelet-theory",bookSignature:"Somayeh Mohammady",coverURL:"https://cdn.intechopen.com/books/images_new/10065.jpg",editors:[{id:"109280",title:"Dr.",name:"Somayeh",middleName:null,surname:"Mohammady",slug:"somayeh-mohammady",fullName:"Somayeh Mohammady"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9644",title:"Glaciers and the Polar Environment",subtitle:null,isOpenForSubmission:!1,hash:"e8cfdc161794e3753ced54e6ff30873b",slug:"glaciers-and-the-polar-environment",bookSignature:"Masaki Kanao, Danilo Godone and Niccolò Dematteis",coverURL:"https://cdn.intechopen.com/books/images_new/9644.jpg",editors:[{id:"51959",title:"Dr.",name:"Masaki",middleName:null,surname:"Kanao",slug:"masaki-kanao",fullName:"Masaki Kanao"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9550",title:"Entrepreneurship",subtitle:"Contemporary Issues",isOpenForSubmission:!1,hash:"9b4ac1ee5b743abf6f88495452b1e5e7",slug:"entrepreneurship-contemporary-issues",bookSignature:"Mladen Turuk",coverURL:"https://cdn.intechopen.com/books/images_new/9550.jpg",editors:[{id:"319755",title:"Prof.",name:"Mladen",middleName:null,surname:"Turuk",slug:"mladen-turuk",fullName:"Mladen Turuk"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],latestBooks:[{type:"book",id:"9243",title:"Coastal Environments",subtitle:null,isOpenForSubmission:!1,hash:"8e05e5f631e935eef366980f2e28295d",slug:"coastal-environments",bookSignature:"Yuanzhi Zhang and X. San Liang",coverURL:"https://cdn.intechopen.com/books/images_new/9243.jpg",editedByType:"Edited by",editors:[{id:"77597",title:"Prof.",name:"Yuanzhi",middleName:null,surname:"Zhang",slug:"yuanzhi-zhang",fullName:"Yuanzhi Zhang"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10020",title:"Operations Management",subtitle:"Emerging Trend in the Digital Era",isOpenForSubmission:!1,hash:"526f0dbdc7e4d85b82ce8383ab894b4c",slug:"operations-management-emerging-trend-in-the-digital-era",bookSignature:"Antonella Petrillo, Fabio De Felice, Germano Lambert-Torres and Erik Bonaldi",coverURL:"https://cdn.intechopen.com/books/images_new/10020.jpg",editedByType:"Edited by",editors:[{id:"181603",title:"Dr.",name:"Antonella",middleName:null,surname:"Petrillo",slug:"antonella-petrillo",fullName:"Antonella Petrillo"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9521",title:"Antimicrobial Resistance",subtitle:"A One Health Perspective",isOpenForSubmission:!1,hash:"30949e78832e1afba5606634b52056ab",slug:"antimicrobial-resistance-a-one-health-perspective",bookSignature:"Mihai Mareș, Swee Hua Erin Lim, Kok-Song Lai and Romeo-Teodor Cristina",coverURL:"https://cdn.intechopen.com/books/images_new/9521.jpg",editedByType:"Edited by",editors:[{id:"88785",title:"Prof.",name:"Mihai",middleName:null,surname:"Mares",slug:"mihai-mares",fullName:"Mihai Mares"}],equalEditorOne:{id:"190224",title:"Dr.",name:"Swee Hua Erin",middleName:null,surname:"Lim",slug:"swee-hua-erin-lim",fullName:"Swee Hua Erin Lim",profilePictureURL:"https://mts.intechopen.com/storage/users/190224/images/system/190224.png",biography:"Dr. Erin Lim is presently working as an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates and is affiliated as an Associate Professor to Perdana University-Royal College of Surgeons in Ireland, Selangor, Malaysia. She obtained her Ph.D. from Universiti Putra Malaysia in 2010 with a National Science Fellowship awarded from the Ministry of Science, Technology and Innovation Malaysia and has been actively involved in research ever since. Her main research interests include analysis of carriage and transmission of multidrug resistant bacteria in non-conventional settings, besides an interest in natural products for antimicrobial testing. She is heavily involved in the elucidation of mechanisms of reversal of resistance in bacteria in addition to investigating the immunological analyses of diseases, development of vaccination and treatment models in animals. She hopes her work will support the discovery of therapeutics in the clinical setting and assist in the combat against the burden of antibiotic resistance.",institutionString:"Abu Dhabi Women’s College",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"3",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Perdana University",institutionURL:null,country:{name:"Malaysia"}}},equalEditorTwo:{id:"221544",title:"Dr.",name:"Kok-Song",middleName:null,surname:"Lai",slug:"kok-song-lai",fullName:"Kok-Song Lai",profilePictureURL:"https://mts.intechopen.com/storage/users/221544/images/system/221544.jpeg",biography:"Dr. Lai Kok Song is an Assistant Professor in the Division of Health Sciences, Abu Dhabi Women\\'s College, Higher Colleges of Technology in Abu Dhabi, United Arab Emirates. He obtained his Ph.D. in Biological Sciences from Nara Institute of Science and Technology, Japan in 2012. Prior to his academic appointment, Dr. Lai worked as a Senior Scientist at the Ministry of Science, Technology and Innovation, Malaysia. His current research areas include antimicrobial resistance and plant-pathogen interaction. His particular interest lies in the study of the antimicrobial mechanism via membrane disruption of essential oils against multi-drug resistance bacteria through various biochemical, molecular and proteomic approaches. Ultimately, he hopes to uncover and determine novel biomarkers related to antibiotic resistance that can be developed into new therapeutic strategies.",institutionString:"Higher Colleges of Technology",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"8",totalChapterViews:"0",totalEditedBooks:"0",institution:{name:"Higher Colleges of Technology",institutionURL:null,country:{name:"United Arab Emirates"}}},equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9560",title:"Creativity",subtitle:"A Force to Innovation",isOpenForSubmission:!1,hash:"58f740bc17807d5d88d647c525857b11",slug:"creativity-a-force-to-innovation",bookSignature:"Pooja Jain",coverURL:"https://cdn.intechopen.com/books/images_new/9560.jpg",editedByType:"Edited by",editors:[{id:"316765",title:"Dr.",name:"Pooja",middleName:null,surname:"Jain",slug:"pooja-jain",fullName:"Pooja Jain"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9669",title:"Recent Advances in Rice Research",subtitle:null,isOpenForSubmission:!1,hash:"12b06cc73e89af1e104399321cc16a75",slug:"recent-advances-in-rice-research",bookSignature:"Mahmood-ur- Rahman Ansari",coverURL:"https://cdn.intechopen.com/books/images_new/9669.jpg",editedByType:"Edited by",editors:[{id:"185476",title:"Dr.",name:"Mahmood-Ur-",middleName:null,surname:"Rahman Ansari",slug:"mahmood-ur-rahman-ansari",fullName:"Mahmood-Ur- Rahman Ansari"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10192",title:"Background and Management of Muscular Atrophy",subtitle:null,isOpenForSubmission:!1,hash:"eca24028d89912b5efea56e179dff089",slug:"background-and-management-of-muscular-atrophy",bookSignature:"Julianna Cseri",coverURL:"https://cdn.intechopen.com/books/images_new/10192.jpg",editedByType:"Edited by",editors:[{id:"135579",title:"Dr.",name:"Julianna",middleName:null,surname:"Cseri",slug:"julianna-cseri",fullName:"Julianna Cseri"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9550",title:"Entrepreneurship",subtitle:"Contemporary Issues",isOpenForSubmission:!1,hash:"9b4ac1ee5b743abf6f88495452b1e5e7",slug:"entrepreneurship-contemporary-issues",bookSignature:"Mladen Turuk",coverURL:"https://cdn.intechopen.com/books/images_new/9550.jpg",editedByType:"Edited by",editors:[{id:"319755",title:"Prof.",name:"Mladen",middleName:null,surname:"Turuk",slug:"mladen-turuk",fullName:"Mladen Turuk"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10065",title:"Wavelet Theory",subtitle:null,isOpenForSubmission:!1,hash:"d8868e332169597ba2182d9b004d60de",slug:"wavelet-theory",bookSignature:"Somayeh Mohammady",coverURL:"https://cdn.intechopen.com/books/images_new/10065.jpg",editedByType:"Edited by",editors:[{id:"109280",title:"Dr.",name:"Somayeh",middleName:null,surname:"Mohammady",slug:"somayeh-mohammady",fullName:"Somayeh Mohammady"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9313",title:"Clay Science and Technology",subtitle:null,isOpenForSubmission:!1,hash:"6fa7e70396ff10620e032bb6cfa6fb72",slug:"clay-science-and-technology",bookSignature:"Gustavo Morari Do Nascimento",coverURL:"https://cdn.intechopen.com/books/images_new/9313.jpg",editedByType:"Edited by",editors:[{id:"7153",title:"Prof.",name:"Gustavo",middleName:null,surname:"Morari Do Nascimento",slug:"gustavo-morari-do-nascimento",fullName:"Gustavo Morari Do Nascimento"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9888",title:"Nuclear Power Plants",subtitle:"The Processes from the Cradle to the Grave",isOpenForSubmission:!1,hash:"c2c8773e586f62155ab8221ebb72a849",slug:"nuclear-power-plants-the-processes-from-the-cradle-to-the-grave",bookSignature:"Nasser Awwad",coverURL:"https://cdn.intechopen.com/books/images_new/9888.jpg",editedByType:"Edited by",editors:[{id:"145209",title:"Prof.",name:"Nasser",middleName:"S",surname:"Awwad",slug:"nasser-awwad",fullName:"Nasser Awwad"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},subject:{topic:{id:"403",title:"Microbial Genetics",slug:"karyology-microbial-genetics",parent:{title:"Karyology",slug:"karyology"},numberOfBooks:5,numberOfAuthorsAndEditors:169,numberOfWosCitations:69,numberOfCrossrefCitations:34,numberOfDimensionsCitations:80,videoUrl:null,fallbackUrl:null,description:null},booksByTopicFilter:{topicSlug:"karyology-microbial-genetics",sort:"-publishedDate",limit:12,offset:0},booksByTopicCollection:[{type:"book",id:"5085",title:"Telomere",subtitle:"A Complex End of a Chromosome",isOpenForSubmission:!1,hash:"2a8f40859d7bc312dea327fd9b058a20",slug:"telomere-a-complex-end-of-a-chromosome",bookSignature:"Marcelo L. Larramendy",coverURL:"https://cdn.intechopen.com/books/images_new/5085.jpg",editedByType:"Edited by",editors:[{id:"14764",title:"Dr.",name:"Marcelo L.",middleName:null,surname:"Larramendy",slug:"marcelo-l.-larramendy",fullName:"Marcelo L. Larramendy"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"4720",title:"Flow Cytometry",subtitle:"Select Topics",isOpenForSubmission:!1,hash:"5a842a00d86bc7f956a5fd1fe6d62b8a",slug:"flow-cytometry-select-topics",bookSignature:"Ingrid Schmid",coverURL:"https://cdn.intechopen.com/books/images_new/4720.jpg",editedByType:"Edited by",editors:[{id:"109787",title:"M.Sc.",name:"Ingrid",middleName:null,surname:"Schmid",slug:"ingrid-schmid",fullName:"Ingrid Schmid"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3536",title:"Chromatin Remodelling",subtitle:null,isOpenForSubmission:!1,hash:"31abe97fe35989e4547bab854b38e03a",slug:"chromatin-remodelling",bookSignature:"Danuta Radzioch",coverURL:"https://cdn.intechopen.com/books/images_new/3536.jpg",editedByType:"Edited by",editors:[{id:"165250",title:"Dr.",name:"Danuta",middleName:null,surname:"Radzioch",slug:"danuta-radzioch",fullName:"Danuta Radzioch"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1578",title:"Flow Cytometry",subtitle:"Recent Perspectives",isOpenForSubmission:!1,hash:"fccad401cbcf998ea4de62d524abf82d",slug:"flow-cytometry-recent-perspectives",bookSignature:"Ingrid Schmid",coverURL:"https://cdn.intechopen.com/books/images_new/1578.jpg",editedByType:"Edited by",editors:[{id:"109787",title:"M.Sc.",name:"Ingrid",middleName:null,surname:"Schmid",slug:"ingrid-schmid",fullName:"Ingrid Schmid"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"2291",title:"Clinical Flow Cytometry",subtitle:"Emerging Applications",isOpenForSubmission:!1,hash:"a5414617aafe62d7c6ec8205028f6967",slug:"clinical-flow-cytometry-emerging-applications",bookSignature:"Ingrid Schmid",coverURL:"https://cdn.intechopen.com/books/images_new/2291.jpg",editedByType:"Edited by",editors:[{id:"109787",title:"M.Sc.",name:"Ingrid",middleName:null,surname:"Schmid",slug:"ingrid-schmid",fullName:"Ingrid Schmid"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],booksByTopicTotal:5,mostCitedChapters:[{id:"44225",doi:"10.5772/55370",title:"Role of Enhancer of Zeste Homolog 2 Polycomb Protein and Its Significance in Tumor Progression and Cell Differentiation",slug:"role-of-enhancer-of-zeste-homolog-2-polycomb-protein-and-its-significance-in-tumor-progression-and-c",totalDownloads:3389,totalCrossrefCites:4,totalDimensionsCites:7,book:{slug:"chromatin-remodelling",title:"Chromatin Remodelling",fullTitle:"Chromatin Remodelling"},signatures:"Irene Marchesi and Luigi Bagella",authors:[{id:"91878",title:"Prof.",name:"Luigi",middleName:null,surname:"Bagella",slug:"luigi-bagella",fullName:"Luigi Bagella"},{id:"164852",title:"Dr.",name:"Irene",middleName:null,surname:"Marchesi",slug:"irene-marchesi",fullName:"Irene Marchesi"}]},{id:"52461",doi:"10.5772/65353",title:"Molecular Diagnosis and Precision Therapeutic Approaches for Telomere Biology Disorders",slug:"molecular-diagnosis-and-precision-therapeutic-approaches-for-telomere-biology-disorders",totalDownloads:1213,totalCrossrefCites:2,totalDimensionsCites:6,book:{slug:"telomere-a-complex-end-of-a-chromosome",title:"Telomere",fullTitle:"Telomere - A Complex End of a Chromosome"},signatures:"Rosario Perona, Laura Iarriccio, Laura Pintado-Berninches, Javier\nRodriguez-Centeno, Cristina Manguan-Garcia, Elena Garcia, Blanca\nLopez-Ayllón and Leandro Sastre",authors:[{id:"179373",title:"Dr.",name:"Leandro",middleName:null,surname:"Sastre",slug:"leandro-sastre",fullName:"Leandro Sastre"},{id:"184869",title:"Dr.",name:"Rosario",middleName:null,surname:"Perona",slug:"rosario-perona",fullName:"Rosario Perona"},{id:"184870",title:"Dr.",name:"Laura",middleName:null,surname:"Iarriccio",slug:"laura-iarriccio",fullName:"Laura Iarriccio"},{id:"184871",title:"MSc.",name:"Laura",middleName:null,surname:"Pintado-Berninches",slug:"laura-pintado-berninches",fullName:"Laura Pintado-Berninches"},{id:"184872",title:"MSc.",name:"Javier",middleName:null,surname:"Rodriguez-Centeno",slug:"javier-rodriguez-centeno",fullName:"Javier Rodriguez-Centeno"},{id:"184873",title:"Ms.",name:"Cristina",middleName:null,surname:"Manguan-Garcia",slug:"cristina-manguan-garcia",fullName:"Cristina Manguan-Garcia"},{id:"184874",title:"Dr.",name:"Elena",middleName:null,surname:"Garcia",slug:"elena-garcia",fullName:"Elena Garcia"},{id:"184875",title:"Dr.",name:"Blanca",middleName:null,surname:"Lopez-Ayllon",slug:"blanca-lopez-ayllon",fullName:"Blanca Lopez-Ayllon"}]},{id:"37421",doi:"10.5772/38616",title:"What Flow Cytometry can Tell Us About Marine Micro-Organisms – Current Status and Future Applications",slug:"what-flow-cytometry-can-tell-about-marine-microrganisms-current-status-and-future-applications",totalDownloads:2396,totalCrossrefCites:2,totalDimensionsCites:4,book:{slug:"flow-cytometry-recent-perspectives",title:"Flow Cytometry",fullTitle:"Flow Cytometry - Recent Perspectives"},signatures:"A. Manti, S. Papa and P. Boi",authors:[{id:"118302",title:"Dr.",name:"Anita",middleName:null,surname:"Manti",slug:"anita-manti",fullName:"Anita Manti"}]}],mostDownloadedChaptersLast30Days:[{id:"49878",title:"Immunophenotyping of Acute Leukemias – From Biology to Clinical Application",slug:"immunophenotyping-of-acute-leukemias-from-biology-to-clinical-application",totalDownloads:2485,totalCrossrefCites:1,totalDimensionsCites:1,book:{slug:"flow-cytometry-select-topics",title:"Flow Cytometry",fullTitle:"Flow Cytometry - Select Topics"},signatures:"Francesco Mannelli",authors:[{id:"178848",title:"M.D.",name:"Francesco",middleName:null,surname:"Mannelli",slug:"francesco-mannelli",fullName:"Francesco Mannelli"}]},{id:"50878",title:"Detection of Anti-HLA Antibodies by Flow Cytometer",slug:"detection-of-anti-hla-antibodies-by-flow-cytometer",totalDownloads:2351,totalCrossrefCites:1,totalDimensionsCites:1,book:{slug:"flow-cytometry-select-topics",title:"Flow Cytometry",fullTitle:"Flow Cytometry - Select Topics"},signatures:"Tülay Kılıçaslan Ayna and Aslı Özkızılcık Koçyiğit",authors:[{id:"178265",title:"Dr.",name:"Tulay",middleName:null,surname:"Kilicaslan Ayna",slug:"tulay-kilicaslan-ayna",fullName:"Tulay Kilicaslan Ayna"}]},{id:"37054",title:"Effect of Monocyte Locomotion Inhibitory Factor (MLIF) on the Activation and Production of Intracellular Cytokine and Chemokine Receptors in Human T CD4+ Lymphocytes Measured by Flow Cytometry",slug:"effect-of-monocyte-inhibitory-locomotion-factor-mlif-on-the-activation-and-production-of-intracellul",totalDownloads:1566,totalCrossrefCites:0,totalDimensionsCites:0,book:{slug:"clinical-flow-cytometry-emerging-applications",title:"Clinical Flow Cytometry",fullTitle:"Clinical Flow Cytometry - Emerging Applications"},signatures:"Sara Rojas-Dotor",authors:[{id:"109461",title:"Dr.",name:"Sara",middleName:null,surname:"Rojas-Dotor",slug:"sara-rojas-dotor",fullName:"Sara Rojas-Dotor"}]},{id:"50807",title:"The Role of Cytometry for Male Fertility Assessment in Toxicology",slug:"the-role-of-cytometry-for-male-fertility-assessment-in-toxicology",totalDownloads:1268,totalCrossrefCites:1,totalDimensionsCites:1,book:{slug:"flow-cytometry-select-topics",title:"Flow Cytometry",fullTitle:"Flow Cytometry - Select Topics"},signatures:"Maria de Lourdes Pereira, Helena Oliveira, Henrique M.A.C.\nFonseca, Fernando Garcia e Costa and Conceição Santos",authors:[{id:"79715",title:"Prof.",name:"Maria De Lourdes",middleName:null,surname:"Pereira",slug:"maria-de-lourdes-pereira",fullName:"Maria De Lourdes Pereira"},{id:"174419",title:"Prof.",name:"Fernando",middleName:null,surname:"Garcia E Costa",slug:"fernando-garcia-e-costa",fullName:"Fernando Garcia E Costa"},{id:"185982",title:"Prof.",name:"Helena",middleName:null,surname:"Oliveira",slug:"helena-oliveira",fullName:"Helena Oliveira"},{id:"185983",title:"Prof.",name:"Henrique M.A.C.",middleName:null,surname:"Fonseca",slug:"henrique-m.a.c.-fonseca",fullName:"Henrique M.A.C. Fonseca"},{id:"185984",title:"Prof.",name:"Conceição",middleName:null,surname:"Santos",slug:"conceicao-santos",fullName:"Conceição Santos"}]},{id:"37421",title:"What Flow Cytometry can Tell Us About Marine Micro-Organisms – Current Status and Future Applications",slug:"what-flow-cytometry-can-tell-about-marine-microrganisms-current-status-and-future-applications",totalDownloads:2393,totalCrossrefCites:2,totalDimensionsCites:4,book:{slug:"flow-cytometry-recent-perspectives",title:"Flow Cytometry",fullTitle:"Flow Cytometry - Recent Perspectives"},signatures:"A. Manti, S. Papa and P. Boi",authors:[{id:"118302",title:"Dr.",name:"Anita",middleName:null,surname:"Manti",slug:"anita-manti",fullName:"Anita Manti"}]},{id:"37445",title:"Retracted: Applications of Quantum Dots in Flow Cytometry",slug:"applications-of-quantum-dots-in-flow-cytometry",totalDownloads:1852,totalCrossrefCites:1,totalDimensionsCites:1,book:{slug:"flow-cytometry-recent-perspectives",title:"Flow Cytometry",fullTitle:"Flow Cytometry - Recent Perspectives"},signatures:"Dimitrios Kirmizis, Fani Chatzopoulou, Eleni Gavriilaki and Dimitrios Chatzidimitriou",authors:[{id:"45414",title:"Dr.",name:"Dimitrios",middleName:null,surname:"Kirmizis",slug:"dimitrios-kirmizis",fullName:"Dimitrios Kirmizis"},{id:"122229",title:"Dr.",name:"Dimitrios",middleName:null,surname:"Chatzidimitriou",slug:"dimitrios-chatzidimitriou",fullName:"Dimitrios Chatzidimitriou"},{id:"134576",title:"BSc.",name:"Fani",middleName:null,surname:"Chatzopoulou",slug:"fani-chatzopoulou",fullName:"Fani Chatzopoulou"},{id:"134577",title:"Dr.",name:"Helen",middleName:null,surname:"Gavriilaki",slug:"helen-gavriilaki",fullName:"Helen Gavriilaki"}]},{id:"51979",title:"Telomeres and Cellular Senescence in Metabolic and Endocrine Diseases",slug:"telomeres-and-cellular-senescence-in-metabolic-and-endocrine-diseases",totalDownloads:1188,totalCrossrefCites:0,totalDimensionsCites:1,book:{slug:"telomere-a-complex-end-of-a-chromosome",title:"Telomere",fullTitle:"Telomere - A Complex End of a Chromosome"},signatures:"Ryusaku Matsumoto and Yutaka Takahashi",authors:[{id:"187040",title:"Dr.",name:"Yutaka",middleName:null,surname:"Takahashi",slug:"yutaka-takahashi",fullName:"Yutaka Takahashi"}]},{id:"52461",title:"Molecular Diagnosis and Precision Therapeutic Approaches for Telomere Biology Disorders",slug:"molecular-diagnosis-and-precision-therapeutic-approaches-for-telomere-biology-disorders",totalDownloads:1213,totalCrossrefCites:2,totalDimensionsCites:6,book:{slug:"telomere-a-complex-end-of-a-chromosome",title:"Telomere",fullTitle:"Telomere - A Complex End of a Chromosome"},signatures:"Rosario Perona, Laura Iarriccio, Laura Pintado-Berninches, Javier\nRodriguez-Centeno, Cristina Manguan-Garcia, Elena Garcia, Blanca\nLopez-Ayllón and Leandro Sastre",authors:[{id:"179373",title:"Dr.",name:"Leandro",middleName:null,surname:"Sastre",slug:"leandro-sastre",fullName:"Leandro Sastre"},{id:"184869",title:"Dr.",name:"Rosario",middleName:null,surname:"Perona",slug:"rosario-perona",fullName:"Rosario Perona"},{id:"184870",title:"Dr.",name:"Laura",middleName:null,surname:"Iarriccio",slug:"laura-iarriccio",fullName:"Laura Iarriccio"},{id:"184871",title:"MSc.",name:"Laura",middleName:null,surname:"Pintado-Berninches",slug:"laura-pintado-berninches",fullName:"Laura Pintado-Berninches"},{id:"184872",title:"MSc.",name:"Javier",middleName:null,surname:"Rodriguez-Centeno",slug:"javier-rodriguez-centeno",fullName:"Javier Rodriguez-Centeno"},{id:"184873",title:"Ms.",name:"Cristina",middleName:null,surname:"Manguan-Garcia",slug:"cristina-manguan-garcia",fullName:"Cristina Manguan-Garcia"},{id:"184874",title:"Dr.",name:"Elena",middleName:null,surname:"Garcia",slug:"elena-garcia",fullName:"Elena Garcia"},{id:"184875",title:"Dr.",name:"Blanca",middleName:null,surname:"Lopez-Ayllon",slug:"blanca-lopez-ayllon",fullName:"Blanca Lopez-Ayllon"}]},{id:"44220",title:"Condensins, Chromatin Remodeling and Gene Transcription",slug:"condensins-chromatin-remodeling-and-gene-transcription",totalDownloads:2090,totalCrossrefCites:0,totalDimensionsCites:1,book:{slug:"chromatin-remodelling",title:"Chromatin Remodelling",fullTitle:"Chromatin Remodelling"},signatures:"Laurence O. W. Wilson and Aude M. Fahrer",authors:[{id:"164464",title:"Mr.",name:"Laurence",middleName:null,surname:"Wilson",slug:"laurence-wilson",fullName:"Laurence Wilson"},{id:"164788",title:"Dr.",name:"Aude",middleName:null,surname:"Fahrer",slug:"aude-fahrer",fullName:"Aude Fahrer"}]},{id:"44225",title:"Role of Enhancer of Zeste Homolog 2 Polycomb Protein and Its Significance in Tumor Progression and Cell Differentiation",slug:"role-of-enhancer-of-zeste-homolog-2-polycomb-protein-and-its-significance-in-tumor-progression-and-c",totalDownloads:3388,totalCrossrefCites:4,totalDimensionsCites:7,book:{slug:"chromatin-remodelling",title:"Chromatin Remodelling",fullTitle:"Chromatin Remodelling"},signatures:"Irene Marchesi and Luigi Bagella",authors:[{id:"91878",title:"Prof.",name:"Luigi",middleName:null,surname:"Bagella",slug:"luigi-bagella",fullName:"Luigi Bagella"},{id:"164852",title:"Dr.",name:"Irene",middleName:null,surname:"Marchesi",slug:"irene-marchesi",fullName:"Irene Marchesi"}]}],onlineFirstChaptersFilter:{topicSlug:"karyology-microbial-genetics",limit:3,offset:0},onlineFirstChaptersCollection:[],onlineFirstChaptersTotal:0},preDownload:{success:null,errors:{}},aboutIntechopen:{},privacyPolicy:{},peerReviewing:{},howOpenAccessPublishingWithIntechopenWorks:{},sponsorshipBooks:{sponsorshipBooks:[{type:"book",id:"10176",title:"Microgrids and Local Energy Systems",subtitle:null,isOpenForSubmission:!0,hash:"c32b4a5351a88f263074b0d0ca813a9c",slug:null,bookSignature:"Prof. Nick Jenkins",coverURL:"https://cdn.intechopen.com/books/images_new/10176.jpg",editedByType:null,editors:[{id:"55219",title:"Prof.",name:"Nick",middleName:null,surname:"Jenkins",slug:"nick-jenkins",fullName:"Nick Jenkins"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:8,limit:8,total:1},route:{name:"profile.detail",path:"/profiles/148496/florian-kohn",hash:"",query:{},params:{id:"148496",slug:"florian-kohn"},fullPath:"/profiles/148496/florian-kohn",meta:{},from:{name:null,path:"/",hash:"",query:{},params:{},fullPath:"/",meta:{}}}},function(){var e;(e=document.currentScript||document.scripts[document.scripts.length-1]).parentNode.removeChild(e)}()