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Biomedical subjects

T Oshima

Publications and source records attributed to T Oshima.

At least 523 records · Page 29Linked to original sources
PubMed1983

Effects of epinephrine on plasma cholesterol levels in rats.

The present study was undertaken to evaluate whether epinephrine increases plasma cholesterol in rats. Epinephrine suspended in sesame oil was subcutaneously administered at 21:00 hr (9 PM). Blood was drawn 12 hr later, and plasma cholesterol was shown to be increased by epinephrine in a dose-dependent manner (0.5-2.0 mg/kg). This epinephrine-induced hypercholesterolemia was enhanced by phentolamine (25 mg/kg) and inhibited by propranolol (25 mg/kg). Although the effect of epinephrine in normal rats was abolished by adrenalectomy, corticosterone (10 mg/kg) increased plasma cholesterol in both normal and adrenalectomized rats. These results demonstrate that epinephrine increases plasma cholesterol levels in rats, and that the effect of epinephrine appears to be mediated by the beta-adrenergic receptors, depending upon adequate amounts of corticosteroids.

Adrenal Glands↗
PubMed1983

Purification and characterization of excretory and secretory antigen of Toxocara canis larvae.

Excretory/secretory (ES) antigen of Toxocara canis larvae was isolated from the culture medium of second-stage larvae by gel filtration. The antigen induced production of not only IgM or IgG but also IgE antibody. The antigen, when treated with guanidine hydrochloride and 2-mercaptoethanol, lost its allergenic activity but retained an ability to induce IgM or IgG antibody. Purified antigen was of glycoprotein nature and had a molecular weight of 35,000. The whole antigen showed a cross-reaction with the serum from Ascaris suum-infected mice. The antigen did not contain phosphorylcholine as a structural component.

Animals↗
PubMed1983

[Epidemiology of Diphyllobothrium latum infection in Japan, with special reference to infection of cherry salmon].

The most characteristic difference of Japanese Diphyllobothrium latum from those of European and Canadian species is it's second intermediate host. The Japanese Diphyllobothrium latum take genus Oncorhynchus as it's most important 2nd intermediate host and plerocercoids are always found in their fillet not in their viscera which phenomena can not be observed in the cases of the latter Diphyllobothrium. From 1977 to 1982, we examined 723 Cherry salmon, Oncorhynchus masou which were caught in the northern Japan Sea from March to May every year. Out of 723 Cherry salmon, 218 (30.2%) were showed the infection of plerocercoids of D. latum (Table 1 & 2). The yearly data of the infection rate of fish varied from 15.9 to 48.4%. The plerocercoids were found most likely in the back hind part of the fish (Figure 1). The sex ratios (Table 4) of Cherry salmon caught in the Japan Sea indicated that these salmon was mainly derived not from Japanese rivers, but from Kamchatka, Sakhalin or the coastal part of Siverian continent (Table 3.) It remains totally unknown where these Cherry salmon got infection of D. latum.

Animals↗
PubMed1982

A pentaamine is present in an extreme thermophile.

A pentaamine was found in cells of an extreme thermophile, Thermus thermophilus, grown at 80 degrees C. The chemical structure was determined to be 1,15-diamino-4,8,12-triazapentadecane, NH2(CH2)3NH(CH2)3NH(CH2)3NH(CH2)3NH2. A trivial name "caldopentamine" is proposed for the new naturally occurring polyamine.

Magnetic Resonance Spectroscopy↗
PubMed1982

A thermostable tRNA (guanosine-2')-methyltransferase from Thermus thermophilus HB27 and the effect of ribose methylation on the conformational stability of tRNA.

An S-adenosylmethionine-=dependent tRNA (guanosine-2'-)-methyltransferase (EC 2.1.1.34) was purified to the homogeneous state (2,400-fold) from a cell-free extract of an extreme thermophile, Thermus thermophilus HB27. The enzyme was highly resistant to heat as reported for other enzymes from thermophilic organism. The enzyme is monomeric and its molecular weight was estimated to be about 20,000. The Km values for S-adenosylmethionine and for Escherichia coli tRNAPhe were determined to be 0.47 microM and 10 nM, respectively, while the Ki for a competitive inhibitor S-adenosylhomocysteine, was 1.67 microM. When yeast tRNAPhe was methylated with the purified Gm-methyltransferase, a stoichiometric amount of methyl group was incorporated into the invariant guanosine at position 18 in the D-loop. Yeast tRNAPhe and E. coli tRNAMet, which were quantitatively methylated with the enzyme, were very similar to the native tRNAs with regard to amino acid acceptor activity and melting temperature, but were more resistant to RNase T1 and RNase A digestions than the corresponding native tRNAs.

Base Sequence↗
PubMed1982

Expression in Escherichia coli of chemically synthesized gene for a novel opiate peptide alpha-neo-endorphin.

Chemically synthesized alpha-neo-endorphin gene was fused to the Escherichia coli beta-galactosidase gene on the plasmid pKO13. The resulting recombinant DNA was used to transform E. coli cells. Radioimmunoassay for alpha-neo-endorphin in CNBr-treated bacterial cells showed that alpha-neo-endorphin was synthesized at approximately 5 x 10(5) molecules per single E. coli cell. One of the transformants, WA802/p alpha NE2, was used for alpha-neo-endorphin purification. From 10.9 g of wet cells, we isolated 4 mg of chemically pure and biologically active alpha-neo-endorphin.

Amino Acid Sequence↗
PubMed1982

A 15N-NMR study on ribonuclease T1-guanylic acid complex.

Ribonuclease T1 is highly specific for the guanylic acid residue in polyribonucleotides. To clarify the origin of the substrate specificity, the interaction sites of guanylic acid with ribonuclease T1 were investigated by the use of 15N-NMR. 95% 15N-enriched guanosine-3'-phosphate was prepared and mixed with purified ribonuclease T1. 15N-NMR spectra of the mixtures at different concentrations were obtained and compared with that of the 15N-enriched substrate alone. Upon complex formation, a 15N signal assigned to the amino group nitrogen at position 2 of guanine shifted and was significantly broadened, suggesting a strong interaction with the enzyme through the amino group. This observation is consistent with the results of studies on the substrate specificity of chemical modification. Nuclear Overhauser effects of signals assigned to N-7 and N-3 were also changed, but not shift was observed. The observations do not support the occurrence of protonation at N-7 upon complex formation, which was previously proposed.

Guanine Nucleotides↗
PubMed1982

Eosinophilia, granuloma formation and migratory behaviour of larvae in the congenitally athymic mouse infected with Toxocara canis.

Peripheral blood eosinophilia, histology of skeletal muscle and brain, and larval recovery were compared between congenitally athymic nude mice (nu/nu) and thymus-bearing heterozygous littermates (nu/+) for 6 weeks following oral infection with Toxocara canis eggs. By comparing patterns of peripheral blood eosinophil levels in nu/+ and nu/nu, two types of eosinophilias, one T cell dependent and the other independent, were observed. Eosinophil infiltration and granuloma formation around larvae in the skeletal muscle were weaker in degree in nu/nu than nu/+. The total number of larvae in nu/+ decreased from 2 to 6 weeks after infection. This decrease was directly related to a decrease in larval number in skeletal muscle, not in brain or other tissues. In contrast, no significant decrease of the total number of larvae was observed in nu/nu. The results indicate that eosinophilia, granuloma formation and larval recovery are closely related to cell-mediated immune mechanisms in T. canis-infected mice.

Animals↗
PubMed1982

Treatment of angina pectoris by percutaneous transluminal coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 12 patients with angina pectoris. PTCA reduced the percentage of stenosis of the coronary artery from 75.6 +/- 10.1 (means +/- SD) to 32.6 +/- 19.5. In addition, anginal attacks per week was reduced from 8.4 +/- 3.2 to 2.5 +/- 0.7. No life-threatening complications were produced by PTCA. The results indicates the effectiveness of PTCA as a treatment for angina pectoris.

Aged↗
PubMed1982

Expression in Escherichia coli of chemically synthesized gene for a human immune interferon.

A 450 base pair fragment of double stranded DNA consisting of a gene for a human immune interferon (146 amino acid residues), initiation and termination signals plus appropriate restriction endonuclease sites was totally synthesized. The synthesis involved preparation of 62 oligodeoxyribonucleotides by rapid, solid phase procedures, and enzymatic ligation of the oligonucleotides. This synthetic gene was expressed in E. coli under the control of the lac UV5 promoter. Molecular weight of IFN-gamma produced by E. coli was estimated to be about 32,000 and 17,000 dalton by gel filtration and SDS-polyacrylamide gel electrophoresis respectively, suggesting that a dimer-form molecule was expressed in E. coli.

Amino Acid Sequence↗
PubMed1982

Colony stimulating factor in human mixed leukocyte cultures.

Colony stimulating factor (CSF) is important for granulocyte/macrophage proliferation and differentiation. We investigated the relationship between the immune reactivity and the production of CSF by using two-way mixed leukocyte cultures (MLC) prepared from human peripheral mononuclear cells obtained with the aid of a blood cell separator. Assessed over 9 days of MLC incubation, the level of CSF in the supernatant reached a maximum at day 7 and then decreased. Optimal number of MLC cells ranged from 1 X 10(6)/ml to 2 X 10(6)/ml; CSF activity decreased at a cell concentration of 4 X 10(6)/ml. There was a differential sensitivity between cluster formation and colony formation to MLC-CSF. MLC-CSF is not species specific and hence, can stimulate both human and mouse CFU-c. MLC-conditioned medium (MLC-CM) appears to be a potentially useful source of CSF.

Animals↗