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Biomedical subjects

S Gomi

Publications and source records attributed to S Gomi.

At least 109 records · Page 6Linked to original sources

New antibiotics SF2315A and B produced by an Excellospora sp. I. Taxonomy of the strain, isolation and characterization of antibiotics.

Two new antibiotics SF2315A and B have been isolated from culture filtrate of an actinomycete strain, Excellospora viridilutea SF2315. They are weakly active against Gram-positive bacteria and inhibited reverse transcriptase of avian myeloblastosis virus. Empirical molecular formula of antibiotics SF2315A and B were determined to be C19H16O5 and C19H20O6, respectively.

Actinomycetales↗

New antibiotics SF2315A and B produced by an Excellospora sp. II. The structural elucidation.

The structures of antibiotics SF2315A and B were determined to be [4aR-(4a beta,12b beta)] or [4aS-(4a alpha,12b alpha)]-4a,5,6,12b-tetrahydro-4a,8-dihydroxy-3- methylbenz[a]anthracen-1,7,12(4H)-trione and [1S-(1 beta,4a beta,6a beta,12 beta,12a beta,12b beta)] or [1 R-(1 alpha,4a alpha,6a alpha,12 alpha,12a alpha,12b alpha)]- 1,4,4a,5,6,6a,12a,12b-octahydro-1,4a,8,12-tetrahydroxy-3-methyl-6a ,12a- epoxybenz[a]anthracen-7(12H)-one, respectively from their spectroscopic analyses and single crystal X-ray diffraction analyses.

Anti-Bacterial Agents↗

Studies on new antibiotics SF2415. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

A new species of Streptomyces is described for which the name Streptomyces aculeolatus is proposed. The organism produces new antibiotics SF2415A1, A2, A3, B1, B2 and B3 active against Gram-positive bacteria. Empirical molecular formulae of the antibiotics SF2415A1, A2, A3, B1, B2 and B3 were determined to be C26H31N2O5Cl, C26H30N2O5, C26H30N2O5Cl2, C26H33O5Cl, C26H32O5 and C26H32O5Cl2, respectively.

Animals↗

Studies on new antibiotics SF2415. II. The structural elucidation.

Structures of new antibiotics SF2415A1, A2, A3, B1, B2 and B3 were deduced from spectroscopic analyses and degradation studies. The structure of SF2415A3, which has the most antibacterial activity, was proposed to be 3,4a-dichloro-9-diazo-3,4, 4a,10a-tetrahydro-6-hydroxy-2,2,7-trimethyl-10a-[(E)-3,7-dimethyl- 2,6-octadienyl]-(2H,9H)naphtho-[2,3-b]pyran-5,8,10-trione. All of antibiotics SF2415 have a semi-naphthoquinone structure.

Anti-Bacterial Agents↗

Dual effect of naloxone on blood platelet aggregation and cerebral blood flow in gerbils.

The effect of naloxone on blood platelet aggregation and cerebral blood flow in gerbils was studied. Administration of naloxone in dose 1 mg/kg to intact gerbils resulted in a marked increase in platelet aggregability accompanied by 27% reduction in cerebral blood flow. Focal cerebral ischemic injury significantly enhanced platelet aggregatory response and treatment with naloxone was without any additional effect on platelet aggregation. Cerebral blood flow in ischemic hemisphere, however, increased following naloxone injection by 46%. In vitro naloxone in millimolar concentrations inhibited platelet aggregation in a dose-dependent way. Apparent decrease in fluorescence of platelet membranes tagged with fluorescence probe due to naloxone suggests conformational changes in platelet membrane as a primary mechanism for the antiaggregatory effect of naloxone in vitro.

Animals↗

Noradrenergic nervous activity in migraine.

The autonomic nervous function in patients with migraine was studied during headache-free intervals. The following observations were made: (1) a decrease in overshoot in Valsalva's maneuver; (2) orthostatic hypotension; (3) low levels of plasma norepinephrine in the steady state; (4) failure in elevation of the plasma norepinephrine level after head-up tilting; (5) dilatation of the pupils after instillation in the eye of 1.25% epinephrine; and (6) a long recovery time in tests by bolus injection of 0.1 microgram of norepinephrine bitartrate per kilogram. The above findings suggest that patients with migraine show sympathetic hypofunction together with denervation hypersensitivity of the iris and the arteries, and that a defective noradrenergic nervous system may play a role in the pathogenesis of migraine.

Adult↗