Study of Morphological Variations of 50 Placentae with Umbilical Cords and its Developmental Relevance.

Introduction: The word “Placenta” is a Latin word and the Greek equivalent word is “Plakons” which means “Flat cake on a plate”. The placenta is a complex multifunctional organ. It provides nutrition, gas exchange, waste removal, endocrine function and immune support. Placenta is a special circulating system to the developing foetus. Being an organ of vital importance for continuation of pregnancy and foetal nutrition it has evolved great interest among the anatomists, embryologists, pathologists and obstetricians. Materials and Methods: The study was done in 50 placentae which were collected from the department of Obstetrics and Gynaecology in collaboration with the department of Anatomy, Kamineni Institute of Medical Sciences, Narketpally, Nalgonda, Telangana, during the period of 2 years. The morphological variations of placenta, the size, shape, weight and attachment of umbilical cord with its blood vessels were observed, recorded and photographed. The prime objective of the study is to compare and evaluate the morphological alterations of placenta and umbilical cord in pregnancy. Results and Conclusion: In the current study, the majority of the placentae showed round shape, few placentae with oval and irregular and with an accessory lobe in single placenta. The current study also includes variations in insertion of umbilical cords was eccentric in majority, central, marginal and velamentous in a few. Pregnancy induced hypertension significantly affects the placenta by reducing weight and it does not have any significant effect on the shape of placenta, umbilical cord insertion and number of cotyledons on maternal surface. The placenta is the most accurate record of the infants prenatal experience.

Apoptosis in the Human Neonatal Vascular Remodeling

BACKGROUND AND OBJECTIVES: In order to verify that apoptosis is one of the possible mechanisms of human neonatal vascular remodeling during transition from fetal to neonatal circulation, we identified apoptosis and analyzed its mechanism by evaluating apoptosis-related genes in umbilical vessel versus ascending aorta, ductus arteriosus (DA) versus adjacent pulmonary artery and aorta, and aorta versus its branching arteries. MATERIALS AND METHODS: Twenty-two umbilical cords, six ductus arteriosus with adjacent aortae and pulmonary arteries, and four aortic arches with their branching great arteries, were obtained from neonates. The presence of apoptotic cells was demonstrated by electron microscopy (EM) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Immunohistochemical staining and Western blotting were used for the analysis of the proteins of apoptosis-related gene. RESULTS: Apoptosis of the smooth muscle cells of the umbilical vessels were identified in all UC, which were examined by electron microscopy and TUNEL. The expressions of Bax and Bcl-X were shown by immunohistochemistry to be stronger in umbilical artery than in the neonatal aorta, but Bcl-2 was weak in both arteries. In the immunoblot analysis of UC, the expression of the proapoptotic short isoform of Bcl-X was stronger than in other tissue, and caspase-3 was selectively activated whereas it was not in the other components of the cardiovascular system. However, the expression patterns of the Fas Ag and Fas ligand (i.e. positive Fas Ag and negative Fas ligand), were similar in umbilical artery and aorta. This Bax-associated apoptosis was also observed in other vascular sites which undergo dramatic hemodynamic changes during birth, such as, the ductus arteriosus and the branching points of the great arteries from the aortic arch. CONCLUSIONS: Apoptosis is involved in the closure and regression of human umbilical vessels and the ductus arteriosus and in the remodeling of the branching great arteries during the neonatal period, where the Bax/Bcl-2/Bcl-X system, not Fas Ag/Fas ligand system, is likely to play a key role.

The Role of Apoptosis in the Closure of Human Umbilical Vessels at Birth and Its Mechanism / 대한내과학회지

BACKGROUND: The mechanism of the closure of umbilical vessels is known to be multifactorial. In order to verify that apoptosis is one of the possible closure mechanisms, we studied to identify apoptosis in umbilical vessels and evaluate its mechanism by studying apoptosis-related gene and the relationship between the pattern of apoptosis and gestational age (GA). METHODS: Twelve umbilical cords of GA of 37-42 weeks were obtained immediatly (less than 10 min. for minimal ongoing external influences) after birth. The presence of apoptotic cells was demonstrated by electron microscopy (EM) and terminal deoxynucleotidyl transferase- mediated dUTP nick end labeling (TUNEL). Immunohistochemical staining and Western blotting were used for the analysis of the proteins of apoptosis-related gene. RESULTS: Apoptosis of the smooth muscle cells of media and intima of umbilical vessels was identified at EM, regardless of GA from 37 to 42 weeks. The proportion of TUNEL (+) cells was 80% in intima, 40% in media, 80% in connective tissue of umbilical cord. The expressions of bax-alpha, bcl-Xs/L were strong in intima, in media and connective tissue, but those of bcl-2 were detected in only in connective tissue, regardless of GA in immunohistochemistry. The ratios of expressions of bax-alpha to bcl-2, bcl-Xs to bcl-XL, did not change with increasing GA from 37 to 42 weeks in Western blotting. CONCLUSION: Apoptosis was identified in umbilical vessels. The closure of umbilical vessels can be explained by apoptosis where the ratios of bax-alpha/bcl-2, bcl-Xs/ bcl-XL play an important role. The fact that there were no differences in the extent of apoptosis and the expressions of bax-alpha/bcl-2, bcl-Xs/bcl-XL according to GA, suggests that apoptosis of umbilical vessels is more dependent on the external stimuli during delivery than GA.