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Biomedical subjects

J Yamada

Publications and source records attributed to J Yamada.

At least 487 records · Page 27Linked to original sources
PubMed1978

Fundamental studies on physiological and pharmacological actions of L-ascorbate 2-sulfate. VI. Effects of L-ascorbate 2-sulfate on lipid metabolism in guinea pigs.

Effects of L-ascorbate 2-sulfate (AAS) on lipid metabolism were studied in guinea pigs maintained on diet I with sufficient L-ascorbic acid (AA) supplement or on diet II without AA supplement. AAS(300 mg/kg) inhibited an increase in serum and liver levels of lipids to a greater degree than AA (175 mg/kg), a reference compond, in hyperlipidemic guinea pigs induced by cholesterol feeding with diets I or II. AAS also induced a decrease in serum and liver levels of lipids in guinea pigs which had been previously maintained for 6 weeks on diet II containing 1.0% cholesterol. AA administration significantly increased AA level in various organs of animals maintained on both the diets containing cholesterol. It also rectified the AA level lowered by previous maintenance on diet II containing cholesterol. AAS showed a slight AA replacing effect on the AA level. Both AA and AAS exerted preventive and curative effects on several symptoms due to chronic AA deficiency.

Animals↗
PubMed1978

Fundamental studies on physiological and pharmacological actions of L-ascorbate 2-sulfate. V. On the hypolipidemic and antiatherosclerotic effects of L-ascorbate 2-sulfate in rabbits.

Effects of L-ascorbate 2-sulfate (AAS) on lipid metabolism and on pathological changes of aorta and visceral organs were investigated in cholesterol fed rabbits, with ascorbic acid (AA) and clofibrate (CPIB) as reference compounds. Administration of AAS (300 and 150 mg/kg) inhibited an increase in the levels of serum total cholesterol, free cholesterol, triglycerides and phospholipids caused by cholesterol feeding. A high dose of AAS prevented an increase of liver weight. An increase in the level of liver cholesterol was inhibited by a high dose of AAS. Both doses of AAS effectively prevented an accumulation of cholesterol in the aorta. The area rate of atheromatous plaque in aorta was less in specimens from both groups of AAS than in those from control I. Pathological changes in intima and media of aorta were milder in specimens from both groups of AAS. Developed of patholoigcal changes in arteries of various organs were prevented with both doses of AAS.

Animals↗
PubMed1978

Endocrine cells in the pyloric region of the Japanese quail (Coturnix coturnix japonica).

The endocrine cells of the pyloric region of the Japanese quail have been studied by light and electron microscopy. The quail pyloric region is a narrow circular zone (about 2 mm in width) between the gizzard and the duodenum. The endocrine cells are concentrated in this region, and they are represented by argyrophil cells. At least five types of endocrine cells are identified in this region by electron microscopy. Type I cells are characterized by having round and large granules (350--550 nm in diameter) whose contents are high to moderate in electron density. Type II cells are characterized by their round and medium-sized granules (250--350 nm) which possess a dense core and a clear halo. Type III cells are characterized by the presence of round and small-cored granules (150--250 nm). Type IV cells contain round and large granules (350--550 nm) of high to low electron density. Type V cells are identified by the occurrence of microfilaments and polymorphous granules of high electron density. All five cell types are recognized as open type cells. The type I, II and III cells are located mainly in the lower half portion of pyloric glands, and the other cell types are located only in the upper half portion of the glands. The type I and II cells are found much more frequently than other cell types. The relationships between the endocrine cells in the quail pyloric region and those of the mammalian digestive tracts were discussed.

Animals↗
PubMed1978

[Clinical and experimental studies on changes in lysosomal enzyme activity in fatty livers (author's transl)].

In order to examine a role of lysosomes in the pathogenesis of fatty livers, analysis was made on possible etiologic factors, clinical signs and symptoms as well as laboratory data of routine liver function tests in 32 subjects with fatty livers. Of 18 cases, enzyme activities of serum acid phosphatase (Acp), beta-glucuronidase (betaG) and n-acetyl-beta-glucosaminidase (nbetaG) were measured and compared with those obtained in 20 normal subjects. Subjective symptoms were observed in 75% of the cases examined, liver swelling in 56%, positive GOT, GPT and BSP retention were in 59, 75 and 68%, respectively. The activity of serum lysosomal enzymes such as Acp, betaG and nbetaG were significantly increased and their incidence was 28, 89 and 78%, respectively. In animal experiments, activities of these enzymes in both serum and liver homogenate were examined in rats with choline-deficient, ethionine-treated, and alcoholic fatty livers. Results obtained were as follows: 1) Lysosomal enzyme activity in sera and livers of choline-deficient rats showed a significant decrease in lysosome-rich fraction and a significant increase in supernatant fraction and sera. 2) The enzyme activity in ethionine-treated rats decreased significantly in lysosome-rich fraction and tended to increase in supernatant fraction. The activity of betaG in sera increased markedly. 3) In rats given ethanol for 4 weeks, the enzyme activity of sera and liver homogenates significantly increased in lysosome-rich fraction. These results indicate that the analysis of serum lysosomal enzyme activity, in the light of clinical features and laboratory data of routine liver function tests, is useful for the diagnosis of the fatty liver. A discussion is given of a possible mode of variation of lysosomal enzymes in rats with fatty livers.

Acid Phosphatase↗
PubMed1977

[A new microtiter plate agglutination method for Brucella canis antibodies (author's transl)].

A micro-agglutination test method for detecting antibodies to Brucella canis was developed. Heat-killed Brucella canis antigens were diluted to an optical density of 0.8 at 420 nm using a spectrophotometer. A volume of 0.025 ml of the antigen was incubated with the same volume of serially diluted sera for 18 to 24 hr at 37 C. Titers of selected dog sera obtained by the present micro-test method were well correlated with those obtained by the classical tube test with satisfactory reproducibility. The micro-test method is more advantageous for screening the antibodies of dog sera because the test can be performed with: (1) smaller volume of the test sera and the antigen (2) shorter period for incubation, and (3) lesser labor.

Agglutination Tests↗
PubMed1976

Fundamental studies on physiological and pharmacological actions of L-ascorbate 2-sulfate. I. On the hypolipidemic effects.

The effects of L-ascorbate 2-sulfate (AAS) on the lipid metabolism were examined in Triton-induced hyperlipemic mice, hypercholesterolemic and normal rats, the following results being obtained. 1) In Triton-induced hyperlipemic mice, AAS (300 mg/kg) significantly decreased the serum cholesterol level, while L-ascorbate (AA, 175 mg/kg) was found ineffective. 2)In hypercholesterolemic rats fed 0.5% cholesterol diet, the consecutive administration of AAS decreased the level of serum cholesterol and liver triacylglycerols. AA only slightly affected these levels. However, both AAS and AA prevented the unordinal increase in the liver weight caused by cholesterol feeding. 3)In normal rats, the administration of AAS over a 4-week period decreased the levels of serum cholesterol and liver triacylglycerols.

Animals↗
PubMed1976

[Establishment of two rat strains for testing coat color genes (author's transl)].

Two tester strains of the rats for testing coat color genes were established. The names, the origins and the genotypes of the rats were as follows: (1) abh (F4) Origin: selected from (BN/fMai X Kyo: Wistar) F2. Genotype: C/C, a/a, b/b, h/h. (2) bhd (F2) Origin: selected from (abh X Tester Moriyama)F2. Genotype: C/C, a/a, b/b, h/h, D/d and C/C, a/a, b/b, h/h, d/d.

Animals↗