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Biomedical subjects

T Kishi

Publications and source records attributed to T Kishi.

At least 199 records · Page 11Linked to original sources
PubMed1979

Plasma aspartate levels in rats following administration of monopotassium aspartate via three routes.

Plasma aspartate levels were measured after potassium aspartate administration through different routes to rats of various ages. The changes in plasma levels were most significant with intraperitoneal injection. Dose- and age-related responses to aspartate load were obtained. The present data suggest that a marked elevation of plasma aspartate levels may result in neuronal necrosis. By comparing the plasma aspartate levels with the results on hypothalamic lesion (Okaniwa et al., 1979), plasma peak value associated with the lesion was estimated in each case of various administration routes and rat ages.

Administration, Oral↗
PubMed1978

Isolation and characterization of mildiomycin, a new nucleoside antibiotic.

A new antibiotic mildiomycin, strongly active against powdery mildew, was isolated from the culture filtrate of Streptoverticillium rimofaciens B-98891. It is a water-soluble basic antibiotic and was purified by ion-exchange and adsorption chromatography. The molecular formula of the purified compound was determined to be C19H30N8O9(H2O) from physical and chemical data. The UV and NMR spectra suggested that this antibiotic is a nucleoside. On acidic hydrolysis it gave 5-hydroxymethyl cytosine which has not previously been found in nucleoside antibiotics.

Antifungal Agents↗
PubMed1977

Streptomyces novoguineensis sp. Nov., an amipurimycin producer, and antimicrobial activity of amipurimycin.

A taxonomic study of Streptomyces strain T-36496, which produces an antibiotic effective against rice blast, revealed that it represented a new taxon and it was named Streptomyces novoguineensis sp. nov. The antibiotic, which was named amipurimycin, showed antifungal activity in vitro and considerable curative effect onleaf blast both in green house and field tests at concentrations ranging from 10 to 20 ppm. It was also effective against neck and panicle blast at the same concentration range.

Animals↗
PubMed1977

Isolation and characterization of a new nucleoside antibiotic, amipurimycin.

A new antibiotic amipurimycin, active against Pyricularia oryzae in vitro and in vivo, was isolated from the culture filtrate of Streptomyces novoguineensis nov. sp. The antibiotic was purified by a combination of ion-exchange and adsorption chromatography based on its amphoteric water-soluble characteristics. Its molecular formula was estimated to be C20H27approximately31N7O8-H2O. Characteristic maxima in the UV spectrum and signals in the PMR and CMR spectra were similar to those of 2-aminopurine 9-(beta-D)-riboside. These findings indicated that amipurimycin is a new nucleoside antibiotic and the first example of a natural product containing 2-aminopurine.

Anti-Bacterial Agents↗
PubMed1977

Bioenergetics in clinical medicine XV. Inhibition of coenzyme Q10-enzymes by clinically used adrenergic blockers of beta-receptors.

Adrenergic blockers for beta-receptors were studied for inhibition of mitochrondrial CoQ10-enzymes. These enzymes are indispensable for the bioenegetics of the myocardium. Propranolol is frequently used to treat hypertension; in some patients, it depresses myocardial function as an adverse reaction. This side effect may be related to the inhibition by propranolol of CoQ10-enzymes of the myocardium. Timolol showed negligible inhibition of the CoQ10-enzyme, NADH-oxidase. Metoprolol was less inhibitory than propranolol. Five alprenolols showed inhibition which approached that of propranolol. The 1-isomer of alprenolol showed weak inhibition of another CoQ10-enzyme, succinoxidase, but the other beta-blockers were essentially non-inhibitory to this enzyme. The drug of choice is timolol, based on negligible inhibition of these bioenergetic enzymes of the heart, which correlates with its pharmacologically low cardiac depressant effects.

Adrenergic beta-Antagonists↗
PubMed1977

Deficiency of vitamin B6 in women taking contraceptive formulations.

The specific activities (S.A.) of the glutamic oxaloacetic transaminase from erythrocytes (EGOT) of 75 women taking 16 diversified contraceptive formulations were determined by the principle (CAS) of unsaturation and saturation of receptors of the Coenzyme-Apoenzyme-System with the coenzyme, pyridoxal 5'-phosphate. 52 women were not taking pyridoxine; 20 were taking 1-5 mg; 3 were taking 25-100 mg. The mean basal S.A. of the 52 women without pyridoxine was lower (p less than 0.01) than for the 20 on 1-5 mg. The mean basal S.A. for the women on 25-100 mg was higher (p less than 0.01) than for the women without pyridoxine. The mean % deficiency for the women on 25-100 mg was negligible and lower (p less than 0.01) than 18+/-8 for the 52 women, and 14+/-6 for the 20 women. These data indicate that 1-5 mg of pyridoxine is inadequate for women on contraceptives. The requisite daily dosage is projected at 50-100 mg. Other data indicate that 5-12 weeks of supplementation with pyridoxine can be required to reach a stable "ceiling" of S.A. of EGOT. This period indicates some regulatory mechanism by diminished levels of the apoenzyme upon gene expression to bring about normal levels of the transaminase.

Adolescent↗
PubMed1976

Bioenergetics in clinical medicine: prevention by forms of coenzyme Q of the inhibition by adriamycin of coenzyme Q10-enzymes in mitochondria of the myocardium.

Adriamycin inhibits the succinoxidase system and the NADH-oxidase system. Both of the intact mitocondrial enzymes and the pentane-extracted preparations are inhibited. The inhibition can be prevented by a molar ratio of coenzyme to adriamycin of 3:1 for coenzyme Q10 (ubiquinone), 5:1 for coenzyme Q7, and 5:1 for coenzyme Q4. Prevention of inhibition was observed in the decreasing order of coenzyme Q10 greater than coenzyme Q7 greater than H6 coenzyme Q4 greater than coenzyme Q4. Adriamycinone was three times more inhibitory than adriamycin, which is compatible with a less polar fragment necessary to inhibit the lipoidal coenzyme Q10. Daunomycinone was not inhibitory at a concentration at which adriamycinone is effective, indicating that the hydroxyl group of the latter could be binding at the receptor, since it should not influence electron transfer or rings B and C.

Animals↗
PubMed1976

Nitrogen source primarily supplied by amino acids and the efficacy for maximal growth of rats.

The effect of osmotic pressure of diets on be food intake of young rats was investigated by comparing the nutritional effect of casein with the corresponding amino acid mixture at 3.2% nitrogen level. Changes in the osmolarity of diets due to the type of dietary carbohydrate had a little effect on food intake, whereas partial substitution of casein for amino acids resulted in significant increase in food intake. Weight gain and food intake of rats fed the 25% replaced amino acid diet were compared with those of rats fed the casein diet. Food intake was lower at 12.5% replacement than at 25% replacement. These observation suggest that a well-balanced amino acid mixture supported maximal growth of rats when 25% of the amino acid mixture was replace with casein. This suggestion could be experimentally confirmed by using an amino acid mixture based on the amino acid composition of whole-egg protein.

Amino Acids↗
PubMed1976

Studies on juvenimicin, a new antibiotic. II. Isolation, chemical characterization and structures.

A series of new macrolide antibiotics was isolated from the culture filtrate of Micromonospora chalcea var, izumensis. The fat-soluble basic complex consisted of eight components which were named juvenimicin A1 approximately A4 and B1 approximately B4. Juvenimicin A3 was found to be identical with rosamicin and the structures of four of the other components (JVM A2, A4, B1 and B3) have been elucidated. Juvenimicin A2 has a methyl group at position 6 instead of the formylmethyl group of juvenimicin A3. Juvenimicin A4, B1 and B3 possess a hydroxyethyl group at position 6. Juvenimicin A4 and B1 differ from each other in the nature of the chromophore. Juvenimicin B3 differs from juvenimicin B1 in that a hydroxymethyl group is present at position 14 in the former.

Animals↗