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Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

At least 883 records · Page 49Linked to original sources

Studies on the interaction between heparin and mouse bone collagenase.

Mouse bone collagenase was found to be tightly bound to a heparin-substituted gel at low ionic strength. The bond was reversible, however, and the collagenase could be elutted at high ionic strength. In addition to providing a method for purifying the enzyme with high yield, the results suggest that the strong ionic bond between heparin and collagenase may partially explain the mechanism wherein heparin enhances the activity of mouse bone collagenase.

Animals↗

Analysis of lipid composition of isolated human sebaceous gland homogenates after incubation with cutaneous bacteria. Thin-layer chromatography.

The effects of specific species of skin bacteria on human sebaceous gland lipids in vitro were analyzed. Isolated dissected sebaceous glands were pooled, homogenized, and sterilized, then incorporated into peptone-yeast extract medium and used as substrate for growth of Propionibacterium acnes, P. granulosum, and Staphylococcus epidermidis subgroup II. The sebaceous lipids were analyzed by thin-layer chromatography before and after bacterial growth. The most striking effect of bacteria on sebaceous gland lipid composition was the hydrolysis of sebaceous triglycerides. The degree of hydrolysis varied with bacterial strain but was most complete with P. acnes and P. granulosum. Staphylococci were not effective in hydrolyzing sebaceous triglycerides at pH 4.5 although, when the pH of the medium was raised to pH 6.4, some strains of staphylococci were as effective as the propionibacteria in hydrolyzing sebaceous triglycerides to free fatty acids. Thus minor changes in acidity may play asignificant role in controlling the lipolytic activity of staphylococci on skin. Another effect of bacterial action on sebaceous gland lipids was the esterification of sebaceous cholesterol to cholesteryl esters. Thus, bacterial action must be taken into account in evaluating studies of alterations in cutaneous cholesterol and cholesteryl esters in skin surface lipids in normal and disease states.

Bacteriological Techniques↗

Regressive childhood psychosis.

1) Forty-seven children were examined and treated because of psychotic signs during the last 13 years, 35 of them improved and the rest deteriorated. 2) Twelve deteriorated children had four similar symptoms in spite of different age of onset. These are fluid regressive motor play, compulsive tendency for the maintenance of sameness, autistic language disorder and body image disorder. 3) The author calls this illness regressive childhood psychosis, and it can occur between six and 10 years of age.

Child↗

[Effect of alfalfa meal on experimental hyperlipidemia].

The influence of alfalfa meal on hyperlipidemia induced by dietary cholesterol was examined and changes in serum total cholesterol (TC), triglycerides (TG) and non-esterified fatty acid (NEFA) in rabbits were recorded. Serum lipid levels of groups treated with alfalfa meal (R-1) as well as those not treated (R-2) were found to be elevated. TC of R-1 was lower than that of R-2. The inhibition effect of alfalfa meal on elevation of TC was apparent to a certain extent. The inhibition effect of alfalfa meal on elevation of TG and NEFA was greater than that of TC, thus it is suggested that alfalfa meal can be successfully utilized for experiments with lipids, when the rabbit is the experimental animal of choice. Effect of riboflavine-2,3,4,5-tetranicotinate (RN-4) on changes of TC, TG and NEFA in rats fed 1% cholesterol diet was also examined. RN-4 was mixed in the diet (0.5, 0.25 and 0.125%). TG levels in groups treated with RN-4 (Rt-2, Rt-3 and Rt-4) were lower than previously observed.

Animal Feed↗

The role of bronchoconstriction in cough reflex.

To investigate the role of bronchoconstriction in the cough reflex, we compared antitussive effects of several drugs with their ability to effect the respiratory tract (i.e. bronchodilation vs. bronchoconstriction). Antitussive activities of five drugs administered either intravenously or orally on electrically-induced cough were evaluated in the non-anesthetized dog. The antitussive activities were as follows: morphine, 0.1 mg/kg (i.v.) and 0.5 mg/kg (p.o.); codeine, 1.0, 4.0; picoperidamine, 2.0, 9.8; piclobetol, 7.6, 9.0; HH-197, 12.5, 143.0, respectively. Morphine, codeine and HH-197 caused bronchoconstriction, but picoperidamine and picrobetol caused bronchodilation. The antitussive and bronchodilatation effects of isoproterenol were abolished by propranolol. Each bronchoconstricting drug (i.e. morphine, codeine and HH-197) was administered concurrently with isoproterenol (10 mug/kg, i.v., and non-antitussive activity), and the cough reflex was observed. Compared with the single administration of each drug, respiratory resistance was decreased and the antitussive effect was increased. These results indicate a strong correlation between bronchodilatation and increased antitussive activity.

Airway Resistance↗

Studies on rat complement. I. Immune adherence and immune hemolysis activities of rat serum.

The measurement of immune adherence reactivity of rat complement is possible at 20 degrees C but not at 37 degrees C. At 37 degrees C, EA rat C1423b site was destroyed by C3b inactivator present in rat serum. The optimal temperature for immune hemolysis reactivity of rat serum is either at 20 degrees C or 21 degrees C and dose response curve showed Von Krough equation with 1/n = 0.25 +/- 0.02. Al lower temperature, rat complement showed much more effective formation of C3 site to reacti with human erythrocyte in immune adherence as compared with guinea pig complement. The measurement of immune adherence reactivity of rat complement was not possible due to C3b inactivator at 37 degrees C but possible at 20 degrees C. It is possible due to lowering the reactivity of C3b inactivator and keeping the reactivity to form active C3b site in immune adherence reaction. Rat complement is more effective to make C3 site as compared with guinea pig complement. This explains the reason why EDTA rat serum has known to be most effective source of late acting complement for measurement of C1 and C2.

Animals↗

[Phamacological studies on bamboo grass (1). Acute toxicity and anti-inflammatory and antiulcerogenic activities of water-soluble fraction(Folin) extracted from Sasa albomarginata Makino et Shibata].

Folin showed no significant toxic effects in mice. The tail pressure test in mice revealed a potent analgesic effect with a hypothermic effect in rats. A significant decrease was also seen in rat dextran or carrageenin edema. There were no inhibitory effects on the formation of granulation tissue in rats. In addition, Folin administration revealed a tendency to a decrease in pylorus-ligated ulcer of the rat by inhibiting the gastric secretion. Some protective effects from aspirin or caffeine-induced gastric ulcers of the pylorus-ligated rats were also obtained in this fraction.

Analgesics↗

Studies on rat complement. II. Complement level in experimental tumor in rats.

In the course of methylcholanthrene induced carcinogenesis in rats, CIA50, C4 and C3 increased as compared with control and correlation of tumor size with increase in CIA50, C4 and C3 was observed. In the course of dimethylaminoazobenzen carcinogenesis of rats, complement level and C3 level decreased but in splenectomized rats fed by dimethylaminoazobenzen showed elevated level of complement system. After Corynebacterium infection, CIA50 and C3 of rats increased. This phenomenon is considered to be one of the essential factors to induce high resistance against tumor inoculation.

Animals↗