Yolk sac carcinoma is an extremely rare tumor in rats and is usually found in the genital system of aged animals. We encountered a yolk sac carcinoma in the pulmonary artery of an 18-week-old female Sprague-Dawley rat. In a repeated dosing toxicity study (once weekly for 4 weeks, intraperitoneal), this rat was unexpectedly found dead on the 55th day after the final administration of the test ar...

BACKGROUND Yolk sac tumor (endodermal sinus tumor) is a rare malignant germ cell tumor arising in the testis or ovary. Extragonadal yolk sac tumor is even rarer and has only been described in case reports. Due to the rarity of the tumors, the appropriately optimal treatment remains unclear. We report a case of yolk sac tumor in the seminal vesicle. CASE A 38-year-old Asian male presented with...

It is well known that avian yolk sac is involved in both primitive and definitive erythropoiesis during embryonic development. Definitive erythropoiesis is first detected at about 4-5 days incubation and its maximum activity is reached between day 10 and 15 of incubation, ending between days 18 and 20 of incubation. We confirmed the definitive erythropoietic foci in the chicken yolk sac through...

Extra-ovarian yolk sac tumor arising in the omentum is extremely rare. As yolk sac tumor originated from the omentum has been rarely reported, its clinical information is very limited. The authors encountered a case of yolk sac tumor originated from the omentum, and reported the case herein. A 32-year-old woman was presented with developed low abdominal distension for a month. Magnetic resonanc...

Although the guinea pig is an important animal model for human placentation, aspects of fetal nutrition are not fully understood, especially in regard to the yolk sac that is regarded to be essential for early development of the embryo. We investigated differentiation by means of histology, histochemistry, immunohistochemistry, and transmission electron microscopy. Data suggest that the guinea ...

Intracranial nongerminomatous germ cell tumors (NGGCTs) in unusual locations are extremely rare. Here, we report a case of a yolk sac tumor in the frontal lobe in a middle-aged patient. A 42-year-old man was admitted to our hospital for headache and nausea. Magnetic resonance imaging (MRI) showed an enhanced mass lesion with a marked cyst component. The serum alpha-fetoprotein (αFP) level was e...

the present study was carried out to investigate the replacement of soybean meal by different levels of canola meal (either with or without canola meal undergoing heat processing). two hundred forty commercial layer hens (lsl strain) at 54th week of age, selected based on the same egg production percentage and body weight. the experimental design was a crd, in a factorial arrangement of 4 repli...

BACKGROUND Due to the rarity of testicular tumors in the prepubertal population, adequate information about their biological course is difficult to document well in a single institution. The purpose of this study was to focus on prepubertal males in an attempt to evaluate clinical features and optimal management among various testicular germ cell tumors with long-term follow-up. METHODS We re...

Conceptuses from 9-5-day pregnant rats have been cultured for 48 h in heat-inactivated homologous serum. Embryonic development was normal. The protein contents of embryos and visceral yolk sacs after different periods of culture were recorded. When I-labelled polyvinylpyrrolidone or [H]dextran were added to the culture serum, radioactivity was accumulated by the yolk sac, but only background le...

Reproductive technologies are widely used in cattle, although many are associated with high-embryonic mortality, especially during early gestation, when the yolk sac undergoes macroscopic changes in structure. We hypothesized that vasculogenesis and angiogenesis are affected, thereby affecting embryonic and placental differentiation. To test this, we studied yolk sac development and gene expres...