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...

To evaluate the possibilities of applying plasma retinol as a biomarker of response in seabirds exposed to chronic low levels of organochlorines, the relationship between yolk content of polychlorinated biphenyls (PCBs) and plasma retinol levels were studied in newly hatched shag chicks (Phalacrocorax aristotelis) from the coast of central Norway. The mean concentration of 29 PCB-congeners (Sig...

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...

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...

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...

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 ...

The yolk sac of the fetal rat and the proximal small intestine of the neonatal rat selectively transport maternal IgG. IgG-Fc receptors are thought to mediate transport across the epithelium of both tissues. We used a mouse mAb (MC-39) against the 45-54-kD component of the Fc receptor of the neonatal intestine to find an antigenically related protein that might function as an Fc receptor in fet...

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...

Progenitor cells capable of giving rise to functional macrophages in in vitro culture were first detectable in the fetal yolk sac of the mouse between day 7 and 8 of gestation. Macrophage progenitors were not detectable outside the yolk sac until day 11. Although the early yolk sac contained macrophage precursors, no cells with the morphologic or functional characteristics of mouse promonocytes...

Background: The bovine yolk sac derives from visceral endoderm and its development occurs between days 18-23 of gestation. The study of this membrane is important for comparative data and has already been performed in rodents, sheep and in cattle, especially Bos taurus. In species Bos indicus the yolk sac has not quite been studied and is believed that there are morphological differences betwee...