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Biomedical subjects

M Koyama

Publications and source records attributed to M Koyama.

At least 253 records · Page 14Linked to original sources
PubMed1985

Partition of divalent and total manganese in organs and subcellular organelles of MnCl2-treated rats studied by ESR and neutron activation analysis.

The possibility that Mn2+ is converted to other valency states in vivo was examined by measuring the ratio of Mn2+, determined by ESR, to total manganese, determined by neutron activation analysis combined with chemical separation, in various organs of control rats and rats treated with MnCl2. In control rats, the total manganese content was high in the thyroid, hypophysis, adrenal, pancreas, liver and kidney, but the Mn2+ contents of these organs were low. In rats treated with Mn2+, the total manganese contents of all organs increased, but the Mn2+ contents still remained low. With regard to subcellular distribution, the total manganese content was high in the nuclear and mitochondrial fractions of the liver and kidney, and in the microsomal and supernatant fractions of the pancreas. The ratio of Mn2+ to total manganese was relatively high in the microsomes of the liver and kidney of control rats, and in the nuclear fraction of the pancreas of Mn2+-treated rats. Thus, the distribution and behavior of manganese in the pancreas were different from those in other organs. Purified liver nuclei and mitochondria were demonstrated to contain manganese, indicating that manganese is tightly bound in each cellular compartment.

Animals↗
PubMed1985

Comparison of the biological properties of purified natural and recombinant human interleukin-2.

We compared the biological properties of the purified recombinant human IL-2 derived from E. coli with those of purified natural IL-2. Both had almost the same specific in vitro activities on a weight basis to support long-term proliferation of IL-2 dependent human peripheral blood lymphocytes, a mouse killer T cell line, and a mouse natural killer cell line; induce killer cells in normal mouse spleen cells; and induce antibody forming cells in nude mouse spleen cells. No differences in these biological activities were found between two forms of natural IL-2 that were separable by reverse phase high performance liquid chromatography.

Animals↗
PubMed1985

Purification and partial sequence analysis of human interleukin-2 derived from peripheral blood leukocytes.

Human peripheral blood leukocyte-derived interleukin-2 (IL-2) was resolved by DEAE-cellulose column chromatography into three peaks of activity, IL-2A, B, and C, with isoelectric points of 7.2, 6.6, and 7.9, respectively. IL-2 A, B, and C were further purified by reverse phase high performance liquid chromatography and resolved into two apparently homogeneous peaks each with identical molecular weight: A-1 and A-2 (Mr17000); B-1 and B-2 (Mr17500); and C-1 and C-2 (Mr14400). The amino acid compositions and partial NH2-terminal amino acid sequences of these molecular species were consistent with those predicted from IL-2 cDNA sequences derived from Jurkat and peripheral blood leukocytes.

Amino Acid Sequence↗
PubMed1985

Translocation of phospholipid-sensitive Ca2+-dependent protein kinase and its substrate, Mr 38,000 protein, in chronic myelocytic and acute myelocytic leukemias.

Phospholipid-sensitive Ca2+-dependent protein kinase (PL-Ca-PK) and its substrates were investigated in neutrophils from normal subjects and in chronic myelocytic and acute myelocytic leukemic cells from patients with or without treatment for leukemia. PL-Ca-PK and its substrates were found in total particulate fraction of normal neutrophils, but less in cytosol. In leukemic cells from chronic myelocytic leukemia patients without treatment, PL-Ca-PK and its substrate, Mr 38,000 protein, increased in cytosol but decreased in total particulate fraction as compared with normal neutrophils. In leukemic cells obtained from chronic myelocytic leukemia patients after treatment mainly with busulfan, PL-Ca-PK and Mr 38,000 protein were increased in total particulate fraction but decreased in cytosol. Using leukemic cells from acute myelocytic leukemia patients with or without treatment, similar results were obtained. The change of localization of PL-Ca-PK and Mr 38,000 protein in leukemic cells appeared to be correlated to the increase or decrease of the number of leukemic cells. These results suggested that PL-Ca-PK together with the substrate, Mr 38,000 protein, might be translocated from total particulate fraction to cytosol with the onset of leukemia, and from cytosol to total particulate fraction accompanying treatment for leukemia.

Cell Division↗
PubMed1985

[Clinical studies of intravenous drip infusion of micronomicin. 1. Pharmacokinetics (Part 2). Intravenous Micronomicin Research Group].

Following the previous report on pharmacokinetics of micronomicin (MCR) in healthy volunteers, pharmacokinetic studies were made again in patients with different degree of renal impairment, and a nomogram was obtained. MCR at a dose of 60 mg/time was given by 1-hour drip infusion to 14 inpatients who consented to receive MCR (age: 35 to 84 years, Ccr: 17.96 to 104.35 ml/min). The blood collection was performed in accordance with the schedule made upon the degree of renal impairment, and the serum concentration was determined by HPLC method. The results were analyzed by MULT program using two- or one-compartment open model. The serum concentration (Cmax) just after administration of MCR was 5.8 +/- 0.9 microgram/ml (mean +/- S.D.). The biological half-life was 1.81 to 12.35 hours. Taking the above results into consideration together with the previous ones of healthy males, the following correlation was obtained between the elimination constant (Kel or beta) and Ccr calculated from S-Cr.: Kel or beta = 0.0038 X Ccr - 0.0097. Further, no side effect was observed in these studies. Elimination of MCR from blood was dependent on renal function like other aminoglycosides, and so it was possible to estimate the elimination constant from Ccr. From these results, a nomogram for the optimum dosage regimen of MCR was obtained.

Adult↗
PubMed1984

Liposome immune lysis assay (LILA): a simple method to measure anti-protein antibody using protein antigen-bearing liposomes.

A new simple immunoassay technique using immune lysis of liposomes was developed to measure antibody against protein antigens. Multilamellar liposomes were composed of dipalmitoylphosphatidylcholine, cholesterol and phosphatidylethanolamine substituted with the hetero-bifunctional cross-linking reagent N-hydroxysuccinimidyl 3-(2-pyridyldithio)propionate (SPDP). The protein antigen (human IgG) was coupled to these liposomes after treatment with SPDP and mild reduction. As a release marker, carboxyfluorescein (CF) was entrapped in the liposomes. The CF release was specific to anti-human IgG antibody and depended on the presence of complement. This technique could detect 10(-15) mol of anti-human IgG antibody or human IgG. The liposomes were stable over 8 months at 4 degrees C under nitrogen gas.

Animals↗
PubMed1984

Correlation of interferon gamma inducing ability to sugar binding specificities of various lectins.

Various lectins were examined to determine possible induction of gamma interferon (IFN-gamma) in human leukocytes. Among the seven positive lectins (Concanavalin A, pea lectin, lentil lectin, rice bran agglutinin, pokeweed mitogen, wheat germ agglutinin, phytohemagglutinin-P), six except rice bran agglutinin belonged to those which recognize carbohydrate chains connected to polypeptide through a glycosylamine linkage between N-acetylglucosamine (GlcNAc) and asparagine residues. The specificity of carbohydrate chain recognition of rice bran agglutinin, residual one positive lectin, has not been reported. Induction of IFN-gamma by wheat germ agglutinin, one of the positive lectins, was inhibited by the addition of GlcNAc during the induction, but not by the addition of glucose, galactose, alpha-methylmannose, N-acetylgalactosamine, N-acetylmannosamine, and lactose.

Binding Sites↗
PubMed1984

Pharmacokinetics of cefpiramide (SM-1652) in humans.

The pharmacokinetics of cefpiramide (SM-1652) were studied after the intravenous administration of single or multiple doses to 21 healthy volunteers. The cefpiramide concentration in plasma at time zero after a bolus intravenous injection of 500 or 1,000 mg was 152 or 303 micrograms/ml, respectively. The maximum cefpiramide level in plasma at the end of a 1-h infusion of 1,000 or 2,000 mg was 166 or 317 micrograms/ml, respectively. The mean plasma half-life of cefpiramide in 15 subjects who received a single dose of 500 or 1,000 mg was 4.44 h. There was no evidence of drug accumulation in plasma when 500 or 1,000 mg of cefpiramide was administered 11 times at 12-h intervals. Urinary excretion of cefpiramide over a 24-h period was ca. 22.5%, regardless of the intravenous administration technique and the dosage. Fecal recoveries of cefpiramide varied from 0 to 36.9% in different subjects.

Adult↗
PubMed1984

Studies on a new nucleoside antibiotic, dapiramicin. II. Isolation, physico-chemical and biological characterization.

New nucleoside antibiotics, dapiramicins A and B produced by a Micromonospora sp. SF-1917, have been isolated by column chromatography on Diaion HP-20 and silica gel. Physico-chemical properties suggested that they are disaccharide nucleosides. Dapiramicin A underwent epimerization, under acidic condition, into epidapiramicin A. Although dapiramicin A generally exhibits no in vitro activity, it is very effective against the sheath blight of rice plants caused by Rhizoctonia solani in a green house test.

Aminoglycosides↗
PubMed1983

Pyrrolomycins C, D and E, new members of pyrrolomycins.

Pyrrolomycins C, D and E, new members of pyrrolomycins produced by Actinosporangium vitaminophilum SF-2080, have been isolated by chromatography on a basic alumina column. Three antibiotics have chlorinated pyrrole nuclei linked directly or via carbonyl function to the dichlorophenol moiety. Pyrrolomycins C and E are active against Gram-positive bacteria, while the spectrum of pyrrolomycin D is broad including Gram-positive, Gram-negative bacteria and fungi.

Anti-Bacterial Agents↗
PubMed1983

Studies on a new nucleoside antibiotic, dapiramicin. I. Producing organism, assay method and fermentation.

A new antibiotic, dapiramicin, has been isolated from the fermentation broth of Micromonospora sp. SF-1917. Since the dapiramicin exhibited essentially no in vitro activity by usual bioassays, two assay methods for dapiramicin were developed, HPLC and a new bioassay by growth inhibition of fungal mycelia on a slide glass. Fermentation of dapiramicin is also described.

Antifungal Agents↗