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Biomedical subjects

K Muto

Publications and source records attributed to K Muto.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effect of sustained-release theophylline administration on pituitary-thyroid axis.

The effect of therapeutic doses of theophylline on the pituitary-thyroid axis was studied in four normal adults and in 15 asthmatic children on theophylline treatment. In the four normal adults, sustained-release theophylline was administered every 12 hr for 60 hr, and serial determinations of serum theophylline, thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3), thyrotropin (TSH), and cyclic AMP (cAMP) were done. In all four cases, serum T4 increased significantly (134% +/- 4% vs basal level) with significant correlation to plasma cAMP level (r = 0.67, p less than 0.05). Changes in T3 and rT3 showed a marked individuality; an increase in T3 occurred in a subject with severe side effects, while the increase in rT3 was observed in a subject with mild side effects. Of the 15 children on theophylline treatment, a higher T4 level was found in 12 and a lower T3 level in nine at 1 wk, but these values returned to the previous level after 4 wk. These results indicate that the therapeutic doses of theophylline significantly but transiently increased the serum T4 level. In most cases, T4 is metabolized to rT3, an inactive metabolite of T4, but in a few cases it is metabolized to T3, which might double the side effects of theophylline.

Adolescent↗
PubMed1982

Banded structure in solitary trichoepithelioma.

Electron microscopical observations were made in a case of solitary trichoepithelioma. Enlarged ERs were found in the tumor cells, showing a peculiar structure with fine granules and an electron-dense banded structure, about 50 nm wide respectively, lying at intervals of 250 nm. In addition to this structure, dense ovoid bodies, about 500 to 600 nm in diameter, were also observed.

Adult↗
PubMed1981

Purification and properties of rabbit liver acid-lipase (4-methylumbelliferyl oleate hydrolase).

An acid lipase was purified from rabbit liver lysosomes by, in sequence, osmotic treatment of the lysosomal fraction, Sephadex LH-20, DEAE-Sephadex A-50, Bio-Gel A-5m, hydroxyapatite and, finally, Sephadex G-200 column chromatography. The substrate was 4-methylumbelliferyl oleate. The enzyme was solubilized by Sephadex LH-20 column chromatography instead of detergents and organic solvents, to obtain an intrinsic macromolecule. 4-Methylumbelliferyl oleate hydrolase, osmotically released from lysosomal particles, had a very high molecular weight (greater than 800 000) which was reduced by gel filtration on a Sephadex LH-20 column; the final molecular weight of the purified enzyme was 58 000. The specific activity of 4-methylumbelliferyl oleate hydrolase increased at almost the same rate as acid cholesterol esterase and triacylglycerol lipase after Sephadex LH-20 column chromatography; the thermal stability of the activity of the three enzymes was almost identical. We also discuss the properties of the enzyme molecule and the interaction between the enzyme and the lysosomal membrane.

Animals↗
PubMed1981

Lymphocyte responsiveness to Dermatophagoides farinae extract in mite-sensitive patients: effect of immunotherapy on cellular proliferative response and specific immunoglobulin E antibody (RAST score).

Lymphocyte responsiveness in vitro and serum levels of specific IgE antibody to mite extracts (Dermatophagoides farinae) were evaluated in mite-sensitive asthmatic patients and in nonatopic individuals. Lymphocytes from untreated mite-sensitive patients (n = 16) responded to mite extracts with greater 3H-thymidine uptake than those from nonatopic individuals (n = 20; p less than 0.01). Specific IgE antibody and total IgE levels were significantly higher in mite-sensitive patients than those in nonatopic individuals. These results suggest that mite-sensitive patients respond to mite allergen with exaggerated lymphocyte proliferation as well as with enhanced specific IgE antibody production. Lymphocyte response to mite extracts was significantly lower in the patients with long-term dust immunotherapy than that in the untreated patients (p less than 0.05), but there was no significant difference in the total IgE and the specific IgE antibody levels between them. Lymphocyte response to Candida albicans was not significantly affected in these patients. These results suggest that as far as mite allergy is concerned, there is some difference in the effect of immunotherapy between lymphocyte proliferative response and specific IgE antibody to mite allergen.

Animals↗
PubMed1980

Lipolytic activities other than lipoprotein lipase in mouse mammary gland.

The lipolytic activities with acid pH optimum were extracted from the acetone powders of the pregnant and lactating mouse mammary glands. Since the activities were strongly inhibited by human serum and albumin which were required for lipoprotein lipase assay, they were considered to be ascribable to lipase(s) other than lipoprotein lipase. Despite the fact that the amount of fatty acid released by the extract prepared from the glands in pregnancy (P-extract) was proportional to the incubation time, the release of the fatty acid by the extract from those in lactation (L-extract) ceased during incubation for a short time. The cessation, however, was avoided by preincubating the L-extract at 50 degrees C for 10 min before assay. In the presence of L-extract, the lipolytic activity in the P-extract was also almost completely lost after a short incubation. From these results, the existence of a heat labile inactivator of the lipolytic activities in lactating mouse mammary glands was suggested.

Animals↗
PubMed1980

Studies on aclacinomycin A resistance in mouse lymphoblastoma.

An aclacinomycin A-resistant subline of mouse lymphoblastoma L5178Y cells was isolated by successive treatment of tumor-bearing mice with the antibiotic. IC50 (50% growth inhibition) in culture was observed at a drug concentration of 0.22 micrograms/ml, which was ca. 11 times higher than IC50 for the parental cells. The resistant cell line exhibited cross resistance to mitomycin C, actinomycin D, macromomycin, auromomycin, vinblastine, cytochalasin B, and other anthracyclines: daunorubicin, adriamycin, 4'-O-tetrahydropyranyladriamycin, baumycins A1 and A2, aclacinomycins B and Y, MA144-S1, 1-deoxypyrromycin, cinerubin A, musettamcyin, and pyrromycin. The 1-deoxy group of anthracyclines showed higher degree of cross resistance than the 1-hydroxy group. No significant cross resistance was found with bleomycin A2, neothramycin and blasticidin S. The resistance to aclacinomycin A and cross resistance to adriamycin were also demonstrated by the method of uridine incorporation. The accumulation or retention studies with [3H]adriamycin revealed that the resistance may be due to decreased uptake and increased efflux of the antibiotic in the resistant cells.

Aclarubicin↗