In the chicken, maternal IgG is deposited in the oocyte yolk and subsequently transported intact by the foetal chick yolk sac into the chick circulation. Such transport appears to require a specific membrane-localized IgG receptor. Using the assay of 125I-yolk IgG binding, we have investigated the existence and properties of such receptors in yolk sac tissue disks. We find that: (1) There are s...

•Yolk sac germ cell tumours are rare in post-menopausal patients.•Most involve mixed yolk sac tumours•Consider diagnosis in patients with a pelvic-abdominal mass and raised AFP.

BACKGROUND: Colibacillosis is one of the most economically important diseases of poultry worldwide. OBJECTIVES: This study was conducted to examine the clonal relatedness and typing of 95 avian Escherichia coli isolates by ERIC-PCR. METHODS: Sixty-three E. coli isolates from two common manifestations of colibacillosis (yolk sac infection and colisepticemia) and 32 isolates from feces of apparen...

BACKGROUND & OBJECTIVE At present, pediatric testicular yolk sac tumor is hard to be diagnosed at early stage, and the treatment strategy for this disease after radical inguinal orchiectomy is uncertain. This study was to summarize our experience in diagnosing and treating clinical stage I pediatric testicular yolk sac tumors. METHODS Clinical data of ten patients with clinical stage I pediat...

BACKGROUND Primary vaginal yolk sac tumor is a rare malignancy in the pediatric population, and a diagnostic challenge and appropriate initial treatment remains unsolved. The aim of this study was to investigate the clinicopathologic features, treatment and prognosis of this tumor. MATERIALS AND METHODS Eight cases of primary vaginal yolk sac tumor were reported with a literature review. RE...

The extra-embryonic coelom (EEC) and secondary yolk sac are prominent structures in the gestational sac during the first trimester of human pregnancy, at a time before the definitive placental circulation becomes established. We propose that the EEC and yolk sac play a critical role in the nutrition of early pregnancy, fulfilling exchange functions which are assumed by the placenta at a later s...

Studies were conducted to explore the synthesis of retinol-binding protein and transthyretin by embryonic and extraembryonic tissues during fetal development in the rat. The levels of retinol-binding protein mRNA and transthyretin mRNA were measured in fetal liver and in extraembryonic tissues by RNA gel blot analysis and hybridization with specific cDNA probes. Retinol-binding protein mRNA and...

Studies of receptor-mediated lipoprotein metabolic pathways in avian species have revealed that physiological intricacies of specific cell types are highly analogous to those in mammals. A prime example for the power of comparative studies across different animal kingdoms, elucidated in the chicken, is that the expression of different lipoprotein receptors in somatic cells and oocytes are the k...

It has been previously suggested that abnormal yolk sac characteristics and slow embryonic foetal heart rate are associated with poor gestational outcome and these parameters can be used to assess foetal viability in first trimester of pregnancies. However there is paucity of evidence in Indian medical literature. The purpose of present study was to examine the role of yolk sac characteristics ...