Beyza Goncu

By Beyza Goncu and Emrah Yucesan

Microencapsulation has been the most frequently used technique for several different disciplines such as cell-based therapies and/or transplantation. Technology is based on the idea of combining and coating a material or isolating from an external source. Microencapsulation may be performed with different materials and, among natural biocompatible materials, alginate-based microencapsulation technique is the most appropriate material for microencapsulation. The structural components of alginate materials are the derivatives of alginic acid, which is found in brown algae as an intercellular gel matrix. This alginate is preferred for clinical applications due to its safety in human studies. Therefore, the choice and the combined system need to be carefully optimized to achieve biocompatible application through cell microencapsulation especially for long term. Specifications of alginate such as primary source, isolation process, viscosity, and purity contribute to improve its biocompatibility. Clinically, cell microencapsulation is the major contribution to the field of transplantation by its technique and additionally provides local immune isolation. This chapter discusses the potential benefits of clinically suitable alginates and their applications. This promising technology may highlight its considerable potential for patients that require transplantation and/or replacement therapy in the future.

Part of the book: Nano- and Microencapsulation

By Beyza Goncu

The parathyroid tissue is composed of the chief, oxyphil, and water-clear cells. The cell type in each parathyroid gland is highly heterogeneous between different pathologies. The parathyroid oxyphil cells are markedly increased in secondary hyperparathyroidism due to chronic kidney diseases. These cells include more eosinophil than oxyphil cells, but they are closer in size to the chief cells. Studies reported that the oxyphil cells are derived from chief cells, and this presents another cell type that occurs as “transitional oxyphilic cells.” As is known, calcium-sensing receptor (CaSR) is expressed abundantly in the chief cells. Expression of CaSR is elevated in disparate parathyroid tissues, which is possibly related to differential expression levels of parathyroid-specific transcription factors including GCM2 (Glial Cells Missing Transcription Factor 2), MAFB (V-maf musculoaponeurotic fibrosarcoma oncogene homolog B), GATA3 (GATA Binding Protein 3), RXR (The retinoid X receptor), and even VDR (Vitamin D Receptor). The pathways that connect CaSR to parathyroid cell proliferation are precisely not known yet. Evaluation of oxyphil and chief cells of parathyroid glands and their differential expression patterns are important to understand the parathyroid function and its behavioral changes due to related diseases. This chapter presents a summary of the current literature on the cell type distribution of parathyroid and pathophysiology by comparing the expression patterns.

Part of the book: Parathyroid Glands

By Beyza Goncu and Robert Gensure

Part of the book: Parathyroid Glands

By Beyza Goncu and Ali Osman Gurol

Understanding the dynamic of the immune system, it is becoming clear that the characteristics of the tissue can be important as immune cells to determine the initiation and progression of an immune response. Among the various responses, tissue-specific immunity can be characterized by determining the Major Histocompatibility Complex (MHC). Human major histocompatibility antigens are known as the “human leukocyte antigen” (HLA) system. HLA contains more than 200 genes and has essential activities in immunology, diseases, and transplantation with gene regions of diverse functions. One of the significant roles in transplantation is donor and recipient selection. In allorecognition, once the recipient antigen-presenting cells (APC) recognize the donor tissue, this leads to activation and migration of the immune cells, which can promote rejection or tolerance. In solid organ transplantation, cultured tissue cells were presumed as passenger-leukocytes free, ensuring mainly prolonged graft survival. However, the current literature paves the way for understanding HLA peptides and allorecognition dynamics to prevent rejection or provide a definition for the donor-recipient match. Based on the given information, this chapter summarizes the HLA expression dynamics and allorecognition status from a transplantation perspective for endocrine glands, including the Adrenal glands, Pancreas, Parathyroid, and Thyroid glands.

Part of the book: Human Leukocyte Antigens