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Biomedical subjects

K Miyata

Publications and source records attributed to K Miyata.

At least 415 records · Page 23Linked to original sources
PubMed1978

Effects of testosterone and orchiectomy on the development of gonadotrophs in neonatal rats with hypophysial stalk section.

The development of gonadotrophs in newborn Sprague-Dawley rats subjected to a hypophysial stalk section (SS) by an electrical cauterization of the infundibulum of the hypothalamus was examined throughout the first 12 postnatal days. The electrical cauterization of the infundibulum was performed during 24 to 30 h after birth, and the pituitaries were studied by immunohistochemical procedures 11 days later. In several animals orchiectomy or an administration of testosterone propionate (TP) was performed simultaneously with the cauterization. The SS animals showed remarkable retardation in body growth and in pituitary development. In males the development of gonadotrophs was strongly suppressed in number and in size after the cauterization, whereas in females the suppression was less prominent. Orchiectomy promoted the development of gonadotrophs in the SS males, while TP administration suppressed it in the SS females. These findings indicate that there is sexual difference in the neonatal development of gonadotrophs even in the pituitary isolated from the hypothalamus and that testosterone inhibits the development of gonadotrophs at the level of the hypophysis during the neonatal period in rats.

Animals↗
PubMed1977

A case of carcinoma of the common bile duct, diagnosed at the non-icteric stage of the disease.

It is rather seldom to detect a cancer of the common bile duct at the non-icteric stage of the disease. This report presents a non-icteric case of carcinoma of the choledochus. A 70-year-old woman complained of r-hypochondralgia with occasional fever. Laboratory examination revealed an increased serum alkaline phosphatase activity without any elevation of serum bilirubin content. The oral cholecystography failed to visualize the gallbladder. By endoscopic retrograde cholangiopancreatography (ERCP), a bilateral filling defect was demonstrated at the common bile duct. Pancreatoduodenectomy was performed and the resected specimen showed a 1 X 2 cm tumor (adenocarcinoma) at the choledochus. She is now in good health over 13 months after operation.

Adenocarcinoma↗
PubMed1975

Peripheral nerves controlling the closure of internal urethral orifice during ejaculation.

The peripheral nervous pathways controlling seminal emission and closure of the internal urethral orifice during ejaculation were examined experimentally using male adolescent dogs. The experimental methods were measurement of the contraction of the internal urethral orifice and measurement of the change of the posterior urethral pressure induced by selective stimulation of the nerves related to the hypogastric nerve. Further, the change of actual ejaculation caused by manual stimulation of the penis was observed after excision of the nerves. Results included the following: (1) The seminal emission and the closure of the internal urethral orifice on ejaculation were controlled by the hypogastric nerve. (2) The nerve fibers which controlled these two phenomena took different paths above the lower mesenteric plexus. (3) Seminal emission was controlled by the splanchnic nerves which originated from the lower thoracic and upper lumbar ganglia of the sympathetic trunk, and the closure of the internal urethral orifice by those which originated from the lower lumbar ganglia of the trunk.

Animals↗