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Biomedical subjects

M Kohsaka

Publications and source records attributed to M Kohsaka.

At least 181 records · Page 10Linked to original sources
PubMed1980

Studies on new phosphonic acid antibiotics. III. Isolation and characterization of FR-31564, FR-32863 and FR-33289.

Three phosphonic acid antibiotics were found to be produced in the fermentation broths of Streptomyces. FR-31564 and FR-32863 were produced by Streptomyces lavendulae. FR-33289 was produced by a strain of Streptomyces, identified as Streptomyces rubellomurinus subsp. indigoferus. They are distinct from, but resemble FR-900098 which was reported in our preceding paper, in their chemical and biological characteristics.

Anti-Bacterial Agents↗
PubMed1980

FR-900148, a new antibiotic. I. Taxonomy, fermentation, isolation and characterization.

A strain of Streptomyces, isolated from a soil sample and identified as Streptomyces xanthocidicus, has been found to produce FR-900148, a new antibiotic containing chlorine in its molecule. The antibiotic inhibits both Gram-positive and negative bacteria. However, it is not effective against wild type of Pseudomonas aerguinosa. Its antibacterial action is considered to result from cell wall synthesis inhibition since it causes spheroplast formation from susceptible cells.

Anti-Bacterial Agents↗
PubMed1980

FR-900137, a new antibiotic. I. Taxonomy and fermentation of the organism, and isolation and characterization of the antibiotic.

A strain of Streptomyces, isolated from a soild sample and identified as Streptomyces unzenensis sp. nov. has been found to produce FR-900137, an interesting new antibiotic, containing phosphorus in its molecule. The antibiotic, obtained as white powder, was shown to inhibit a wide variety of Gram-positive and Gram-negative bacteria except Pseudomonas aeruginosa.

Animals↗
PubMed1980

Studies on new phosphonic acid antibiotics. II. Taxonomic studies on producing organisms of the phosphonic acid and related compounds.

A new species of Streptomyces which produces a new cell wall-inhibitory antibiotic, FR-900098 containing phosphonic acid in its molecule, is named and described. The species name proposed, Streptomyces rubellomurinus, refers to the aerial mass color. Streptomyces rubellomurinus subsp. indigoferus also produces FR-900098 and the related compound FR-33289. FR-900098 related compounds, FR-32863 and FR-31564 are produced by Streptomyces lavendulae.

Anti-Bacterial Agents↗
PubMed1979

The effect of insulin on elder phenylketonuric patients.

The effect of insulin on blood phenylalanine, tyrosine and catecholamine levels was investigated in six phenylketonuric patients and eight normal controls. The plasma phenylalanine-tyrosine ratio was lower after insulin injection in five of six patients. In four patients the plasma catecholamine concentrations increased. The tyramine level was remarkably high one hour after insulin injection. Urinary homovanillic acid was elevated in four patients. It appeared that insulin treatment produced some therapeutic effects in patients with smaller phenylalanine-tyrosine ratios or elevated catecholamine levels.

Adolescent↗
PubMed1979

Sex hormones metabolism in the brain: influence of central acting drugs on 5 alpha-reduction in rat diencephalon.

Rats after adrenalectomy-testectomy showed a gradual increase in diencephalon 3-oxo-5 alpha-steroid: (acceptor) delta4-oxidoreductase (5 alpha-reductase) activity for 3 days. The activity then returned near to the normal range on the 4th postoperative day. When rats were given testosterone propionate (TP) 3 days after adrenalectomy-testectomy, diencephalon 5 alpha-reductase activity returned to the preoperative range 2 hr after TP administration. Diencephalon 5 alpha-reductase activity showed a highly significant increase (p less than 0.01) after a single administration of carbamazepine, reserpine, diazepam, phenytoin, phenobarbital or disulfiram. A significant increase (p less than 0.05) was also found after a single administration of methylphenidate, caffeine or methamphetamine. Plasma testosterone decreased concurrently after administration of all these agents, except diazepam. Diencephalon enzyme activity decreased significantly after repeated disulfiram administrations (p less than 0.01) but increased significantly after methamphetamine administrations (p less than 0.05). Plasma testosterone showed a tendency to decrease after repeated methamphetamine administrations but tended to increase after repeated disulfiram administrations.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1978

Cell-free ring expansion of penicillin N to deacetoxycephalosporin C by Cephalosporium acremonium CW-19 and its mutants.

To examine microbiological ring expansion of penicillin N to a cephalosporin, we obtained five mutants of Cephalosporium acremonium blocked in beta-lactam antibiotic biosynthesis from 2500 survivors of mutagenesis. In submerged fermentation, mutants M-0198, M-0199, and M-2351 produced no beta-lactam antibiotic (type A), whereas mutants M-1443 and M-1836 formed penicillin N but not cephalosporin C (type B). Cell-free extracts of type A mutants converted penicillin N to a cephalosporin; those of type B mutants did not. The product of the cell-free reaction was identified as deacetoxycephalosporin C by thin-layer chromatography, paper chromatography, paper electrophoresis, and enzyme tests. These data strongly support our hypothesis that penicillin N is an intermediate of cephalosporin biosynthesis.

Acremonium↗
PubMed1978

Homovanillic acid in human cerebrospinal fluid.--Its concentration gradient and reduced levels in patients with epilepsy.

The homovanillic acid (HVA) concentrations in the lumbar cerebrospinal fluid (CSF) were determined in 38 epileptic and 39 control patients. The mean concentration of HVA was 23.9 ng/ml +/- 2.8 SEM for the epileptic group and 30.2 ng/ml +/- 2.1 SEM for the control group, respectively. Thus, HVA was significandly reduced in the patients with epilepsy compared with the controls. The mean HVA in the female patients was higher than in the male patients in both groups but this failed to reach statistical significance. There was no apparent relationship between the degree of reduced HVA concentration and other clinical indexes of the epilepsy (age, type and frequency of seizures, and anticonvulsant medication). For the determination of concentration gradient of HVA three fractions of the spinal CSF were obtained from 11 patients. A pronounced gradient of HVA concentration was found with a ratio of 1 : 1.46 : 1.97 for the first, second and third fractions. This suggests that a standardized conditions for collecting CSF should be employed to study HVA levels in humans.

Adult↗