Search PubMed⌕ Search

Biomedical subjects

M Takeuchi

Publications and source records attributed to M Takeuchi.

At least 991 records · Page 55Linked to original sources
PubMed1981

Spontaneous occurrence of gamma-glutamyl transpeptidase-positive hepatocytic foci in 105-week-old Wistar and 72-week-old Fischer 34 male rats.

Spontaneous hepatic changes in old male rats of Wistar and F344 inbred strains were studied histochemically. gamma-Glutamyl transpeptidase-positive hepatocytic foci and cholangiolar proliferation associated with fibrosis and inflammatory infiltration were common findings in the old rats of both strains. Histochemical properties of the hepatocytes of the foci were similar to those of hyperplastic foci seen in early stages of liver carcinogenesis due to various chemical carcinogens. The incidence of the foci was 2.52/cm2 of the histochemically stained sections in 105-week-old male Wistar and F344 rats, and the presence of other spontaneous neoplastic and nonneoplastic changes was revealed.

Age Factors↗
PubMed1981

[Placental transfer and distribution of betamethasone 17,21-dipropionate in various regions of the brain of pregnant rats and mice (author's transl)].

As betamethasone 17,21-dipropionate induces adrenal atrophy in rat dams and adrenal hypertrophy in the fetus, we investigated the placental transfer of this compound using autoradiography and liquid scintillation counting in animals in the late stages of pregnancy. In these two species, 3H-betamethasone 17,21-dipropionate and/or its metabolites transferred across the placental barrier into fetal tissues and were distributed at levels lower than detected in the maternal tissues. The rat fetus showed a high uptake of radioactivity in the adrenal cortex. In pregnant rats, the ratios of the radioactivity in the adrenal cortex. In pregnant rats, the ratios of the radioactivity in brain tissues to the plasma in fetuses were much higher than in the dams after the administration of 3H-betamethasone 17,21-dipropionate or 3H-betamethasone. In the dams given 3H-betamethasone 17,21-dipropionate, the accumulation of radioactivity in the hypothalamus and septum was significantly greater than in other regions. The present study suggests that betamethasone 17,21-dipropionate or its metabolites transferred across the placental barrier following administration to the mother rat may produce an adrenal hypertrophy in the fetus and that accumulation of radioactivity in the hypothalamus of the dam may be related to a suppression of the function of hypothalamo-pituitary-adrenal axis.

Animals↗
PubMed1981

[Two-dimensional echocardiographic diagnosis of congenital malformations of the aorta in infants and children (author's transl)].

Two-dimensional echocardiographic studies were performed in 23 patients with coarctation of the aorta, 5 with interruption of the aortic arch, 6 with supravalvular aortic stenosis, 3 with truncus arteriosus, 2 with anomalous origin of the right pulmonary artery from the ascending aorta and 2 with aorto-pulmonary septal defect. The diagnosis was confirmed in each patient by surgery and/or cardiac catheterization and angiography. Visualization of the junction of isthmus and the descending aorta was possible in 18 of 23 patients with coarctation by two-dimensional echocardiography. In 13 patients correct diagnosis was obtained prospectively and in 2 patients coarctation was detected retrospectively. In only one of the 5 patients with interruption correct diagnosis was obtained and in 3 patients it was difficult to differentiate interruption from coarctation. In 5 of the 6 patients with supravalvular aortic stenosis, visualization of the area of obstruction was possible to two-dimensional echocardiography. In 2 of the 3 patients with truncus arteriosus, in whom none of the 2 had anomalous origin the right pulmonary artery from the ascending aorta and one of the 2 had aorto-pulmonary septal defect, correct diagnosis was obtained prospectively by two-dimensional echocardiography. Two-dimensional echocardiography may offer a useful noninvasive method for the direct visualization of aortic obstructive lesions and aortic malformations.

Angiography↗
PubMed1980

Angiotensin-converting enzyme in human prostate.

The activity of angiotensin-converting enzyme in human prostate was measured by spectrophotometric method using Hippuryl-L-histidyl-L-leucine (Hip-His-Leu) as substrate. Benign hypertrophic prostate had significantly higher concentration of angiotensin-converting enzyme (1.99 +/- 0.36 (S.E.M.) units/g of tissue, n = 13) than normal prostate (0.44 +/- 0.1 units/g of tissue, n = 5) (p less than 0.01). More than 80% of the enzyme activity occurred in soluble fraction of normal and hypertrophied prostates. Human prostatic angiotensin-converting enzyme, partially purified from benign hypertrophic prostates, had an apparent molecular weight of 290,000 and pI of 4.1. Optimum pH of the enzyme with KM value of 1.0 mmol/l was 7.8 in 0.1 mmol/l borate/sodium/carbonate buffer. The enzyme was competitively inhibited by captopril (Ki, 1.8 nmol/l).

Chlorides↗
PubMed1980

Mammary tumorigenic effect of a new nitrosourea, 1,3-dibutyl-l-nitrosourea (B-BNU), in female Donryu rats.

Four groups (groups 1-4) of female Donryu rats were given continuously 400, 200, 100, or 0 ppm solution of 1,3-dibutyl-l-nitrosourea (B-BNU) as their drinking water, and were studied for the development of tumors. The incidence of mammary tumors was 15/19 (79%), 20/24 (83%), 21/26 (81%), and 8/25 (32%) in groups 1, 2, 3, and 4, respectively. In addition, hematopoietic neoplasms, uterine tumors, and vaginal tumors developed in 13, 11, and six rats, respectively in 69 treated rats. Other tumors were infrequent.

Animals↗
PubMed1980

Intrarenal arteriovenous malformation.

Our surgical experience with 7 cases of intrarenal vascular malformation is reported. Based on angiographic criteria the so-called congenital arteriovenous fistula of the kidney may be classified either as the cirsoid type, which represents a truly congenital form of arteriovenous malformation, or as the aneurysmal type, which is considered to be idiopathic or spontaneous. These 2 types of arteriovenous malformations are compared with regard to clinical presentation and the choice of surgical treatment for each type is discussed.

Adolescent↗
PubMed1980

[Intravenous chronic toxicity of lentinan in rats: 6-month treatment and 3-month recovery (author's transl)].

Chronic toxicity of lentinan was studied in male and female JCL : SD rats. Lentinan was given intravenously into tail vein. Dosage levels employed were 0 (5% mannitol), 0.01, 0.1, 1 (with or without dextran), and 10 mg/kg/day for 6 months in a volume of 1 ml/100 g body weight. After 6 months, the treatment was discontinued and a recovery study was performed for 3 months. Rats receiving 10 mg/kg had redness and necrosis of the tail, the treatment was stopped at week 5, and the rats were sacrificed. Rats receiving 1 mg/kg showed redness of the ear, tail, and scrotum, which was remarkable in the 2nd and 3rd months. Body weight gains were not adversely affected. Laboratory examinations revealed an increase in leukocyte count, decreases in differential eosinophil count and platelet count, and an increase in serum beta-globulin level in drug-treated rats. At autopsy after 6 months, rats from the drug-treated groups had pulmonary hemorrhage and enlargements of the spleen and mesenteric lymph nodes. Histologic changes attributable to treatment included (1) activation of reticulo-endothelial system such as small epithelioid cell nodule in the liver, spleen, and mesenteric lymph nodes, and mobilization of Kupffer cells; (2) arteritis in various organs, especially notable in the spleen, testis, and epididymis ; (3) hemorrhage in the lung; and (4) hypospermatogenesis. All these changes described above had a propensity to recover. The maximum no effect level was estimated to be less than 0.01 mg/kg in the present study in male and female rats.

Animals↗