Part of the book: Chlamydia
Part of the book: Chlamydia
The unbalanced chromosomal anomalies generate an abnormal pattern of development and usually determine miscarriage. The most frequent prenatal chromosomal anomalies are X monosomy, trisomies of chromosomes 21, 18, 13, 16, 8, triploidy and tetraploidy. Identification of chromosomal anomalies can be done by prenatal screening and diagnosis. Prenatal screening is biochemical, sonographic or molecular (detection of fetal DNA in maternal blood). Biochemical screening can be done in the first or second trimester. First-trimester screening is based on the detection in maternal serum of beta-hCG (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A). Biochemical screening in the second trimester requires the detection of alpha-fetoprotein (aFP) hGC, unconjugated estriol (μE) and inhibin A. The sonographic examination can be used in the first or second trimesters. In the first trimester, an ultrasound can identify soft markers like nuchal translucency, nasal bone and ductus venous flow. In the second trimester the sonographic examination can identify congenital anomalies or different soft markers. Prenatal chromosomal diagnosis requires an invasive procedure to obtain embryonic or fetal material. Such procedures are represented by chorionic villus sampling amniocentesis or cordocentesis. The fetal cells are used for cell cultures (in cytogenetic methods) or for molecular analyses (FISH, QF-PCR, MLPA, array-CGH).
Part of the book: Congenital Anomalies
Homocysteine, a non-proteinogenic sulfur-containing amino acid, was discovered in 1932, and 30 years passed until, in 1969, for the first time, its involvement in pathology was reported. It was only in the last two decades that homocysteine has become a subject of scientific interest and has begun to be intensively studied. A large number of scientists consider homocysteine as an independent risk factor particularly for cardiovascular disease, while others indicate homocysteine as a marker of this disease. Both sides bring scientific arguments for their opinions, yet the dilemma of homocysteine characterization still persists. Although the reported studies do not lead to a unique answer, it is generally accepted that homocysteine is associated with vascular dysfunction. Numerous scientific data show that the link between homocysteine and inflammation is achieved via the reactive oxygen species (ROS) pathway. The latest data indicate hydrogen peroxide as a possible messenger in cellular signaling in physiological or pathological processes and present the consequences of disturbing the oxidation-reducing balance. In this chapter, we present the latest scientific evidences gathered from the literature for both hypotheses regarding homocysteine involvement in pathology, and we propose a possible mechanism of action for homocysteine, based on our preliminary (yet unpublished) work.
Part of the book: Non-Proteinogenic Amino Acids
The hysteroscopic myomectomy is a very important application of the gynecologic endoscopy, as it allows minimal invasive removal of the type 0, 1, and 2 fibroids with minimal damage to the uterine wall. In the last decade, new developments of this method allowed an even less invasive approach, with possibility of ambulatory procedure. We discuss the importance of these new developments, based very much on the pseudocapsule of the myoma, and analyze the literature data regarding the outcome. The cold loop resection is a technique that could be used in type 1 and type 2 myomas, with less complications and limitations than the classical electrical resectoscope. Another development, more useful for type 0 and 1 myoma, is the hysteroscopic morcellator, similar to the laparoscopic one, but providing a faster and safer procedure. We also update the complications of hysteroscopic myomectomy and their management, including long-term and obstetrical complications related to hysteroscopic myomectomy. In conclusion, new developments and studies show that hysteroscopic myomectomy has become a valid endoscopic technique ready to be used by many specialists.
Part of the book: Leiomyoma