A case of yolk sac tumor in a nine-month-old girl is presented. Vaginal hemorrhage was observed during the patient's check-up at the Bjelovar Children's Outpatient Clinic. The patient was referred to the Department of Pediatrics at the Zagreb University Hospital, where an endodermal tumor of the vaginal yolk sac was diagnosed. The patient underwent surgery, followed by chemotherapy. She is now ...

Formation of the yolk sac vascular system and its connection to the embryonic circulation is crucial for embryo survival in both mammals and birds. Most mice with mutations in genes involved in vascular development die because of a failure to establish this circulatory loop. Surprisingly, formation of yolk sac arteries and veins has not been well described in the recent literature. Using time-l...

We have examined the role of germline-specific chromosomal determinants of development in the mouse. Studies were carried out using aggregation chimaeras between androgenetic----fertilized embryos and compared with similar parthenogenetic----fertilized chimaeras. Several adult chimaeras were found with parthenogenetic cells but none were found with androgenetic cells. Analysis of chimaeras at m...

Two prominent alpha-fetoproteins are found in chick embryo plasma up to and slightly beyond hatching. Only antisera against chick embryo plasma resolve them. alpha3-fetoprotein is a lipoprotein, the first fetoprotein thus described. It probably functions to transport lipid from the yolk to the embryo. The other fetoprotein (alpha4) is a major glycoprotein. Both are made by the liver and yolk sa...

Two practical methods are reported for treating feral Baltic salmon with thiamine hydrochloride against M74 syndrome (abnormally high yolk-sac fry mortality of the Baltic salmon). Both bathing of the yolk-sac fry in thiamine hydrochloride (1000 mg l-1, 1 h) and a single intraperitoneal injection given to the female brood fish (100 mg kg-1 fish) during the summer 3 mo before stripping were shown...

It is well established that hemopoietic cells arising from the yolk sac invade the avian embryo. To study the fate and role of these cells during the first 2.5-4.5 days of incubation, we constructed yolk sac chimeras (a chick embryo grafted on a quail yolk sac and vice versa) and immunostained them with antibodies specific to cells of quail hemangioblastic lineage (MB1 and QH1). This approach r...

The teratogenicity of rabbit anti-rat visceral yolk-sac antiserum, injected into pregnant rats at either 8-5 or 9-5 days of gestation, has been confirmed. Normal rabbit serum was found not to be teratogenic. When conceptuses from 9-5-day pregnant rats were cultured for 48 h in heat-denatured homologous serum, to which antiserum was added for the final (or the penultimate) 6 h of culture, embryo...

objective: on a global scale, stratospheric ozone depletion has caused an increase in uv-b radiation reaching the earth's surface. ultraviolet radiation has long been suspected to be harmful to aquatic organisms. materials and methods: in order to study ionocyte localization (by na+/k+-atpase immunolocalization) and the effects of uv radiation on the ionocytes of skin and gills, the alevins of ...

There have been found at least three kinds of protein m the yolk throughout the embryogenesis of rainbow trout, by electrophoretic analysis1l. In rainbow trout it is well known that the egg hatches out in 20-30 days after fertilization and the yolk content in the sac fry lasts for a further period of 20-30 days, then signs of starvation begin to appear. Therefore, it was suggested that the yolk...