Yolk sac hematopoiesis is characterized by restricted hematopoietic cell differentiation. Although multipotent hematopoietic progenitor cells have been identified in the early yolk sac, long-term multilineage repopulating (LTMR) hematopoietic stem cell (HSC) activity has not been demonstrable before day 11 postcoitus (PC) using standard transplantation assays. In the present study, day-10 PC yo...

alpha-fetoprotein producing gastric cancer accounts for less than 10% of the gastric adenocarcinomas. different histologic subtypes may exist, the least common of which is yolk sac morphology. to the best of our knowledge less than 10 cases have been reported with high alpha-fetoprotein and yolk sac components, either pure or mixed with ordinary adenocarcinoma of the stomach. during 10 years, f...

Gastric yolk sac tumors are extremely rare and their prognosis is poor; most patients have widespread metastases at the time of diagnosis. The treatment of gastric yolk sac tumors consists of aggressive chemotherapy combined with radiotherapy and surgery. Here, we first report a case of gastric yolk sac tumor presenting as an early gastric cancer that was cured after a gastrectomy with lymphade...

Previous experiments have proved that thermodynamically unstable calcium carbonate vaterite can exist for long periods in the yolk sac of a pigeon embryo. The aim of this article was to demonstrate the effect of in vitro mineralization of yolk sac fluid on calcium carbonate by direct precipitation. Experiments were conducted using pigeon yolk sac fluid and using lecithin extracted from pigeon y...

Maternal lipoproteins provide nutrients to the fetus via the placenta, yolk sac, and uterine membrane plus decidua. To determine the transport processes that are responsible for the removal of lipoproteins from the maternal circulation, we measured the clearance rates of maternal LDL and HDL in vivo, as well as the tissue distribution of expression of the LDL receptor, glycoprotein 330 (gp330) ...

Intracranial germ cell tumours are rare. The incidence of primary intracranial yolk sac tumour is even more uncommon, with only two reported cases being associated with Down's syndrome in the English literature. This report details the findings of yolk sac tumour in the pineal region affecting a 22 year old Chinese man with Down's syndrome. Histology revealed yolk sac tumour with only a solid p...

Vascular endothelial growth factor A (VEGFA) plays a pivotal role in the first steps of endothelial and haematopoietic development in the yolk sac, as well as in the establishment of the cardiovascular system of the embryo. At the onset of gastrulation, VEGFA is primarily expressed in the yolk sac visceral endoderm and in the yolk sac mesothelium. We report the generation and analysis of a Vegf...

Yolk sac tumour is germ cell tumour commonly found in children and infants under three years of age in its pure form with a good prognosis. The commonest location for the yolk sac tumour is gonads i.e. testis and gonads. Yolk sac tumour is rarely reported in extra- gonadal locations. Parapharyngeal space is an uncommon site for mature teratoma and very few cases have been reported in adults and...

Yolk sac tumor is a rare germ cell neoplasm occurring mainly in the gonads. Extragonadal yolk sac tumor is a very rare malignancy; its main distribution is along the midline of the body at three principal sites: mediastinum, central nervous system and retroperitoneum. Most yolk sac tumors are diagnosed between seven months and three years of age. We report a case of primary yolk sac tumor in a ...

Pregnancies with a very large yolk sac are generally always associated with poor outcomes. Herein, we present a case in which a very large yolk sac (mean diameter, 8.1 mm) and a bicornuate uterus were shown on transvaginal sonography in the first trimester, but which resulted in a live birth. To our knowledge, this is the largest yolk sac among all cases accompanying live births which have been...