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Biomedical subjects

S Murakawa

Publications and source records attributed to S Murakawa.

At least 55 records · Page 3Linked to original sources
PubMed1990

[A case of ruptured pseudoaneurysm of the aortic arch associated with hemoptysis and hoarseness].

We experienced a case of the ruptured pseudoaneurysm of the aortic arch. Patient complained left anterior chest pain, back pain and hoarseness. Considering the past history of pulmonary tuberculosis, emergency operation was performed median sternotomy approach and using aortic occlusion balloon catheter method and selective cerebral perfusion. Woven dacron graft was anastomosis intraluminal aneurysm. Postoperative course was good. Median sternotomy approach and AOBC method were better than intercostal approach method, because of a little bleeding, short operative time and method.

Aged↗
PubMed1989

Biosynthesis of monacolins: conversion of monacolin L to monacolin J by a monooxygenase of Monascus ruber.

The microbial metabolites monacolins J and L are specific inhibitors of 3-hydroxy-3-methylglutaryl CoA reductase, the rate-limiting enzyme in cholesterol synthesis. The producing strain Monascus ruber M 4681 was found to convert exogenously added monacolin L to J. In this hydroxylation reaction 18O2 was incorporated into monacolin L, giving [18O]-monacolin J. The cell-free extracts of M. ruber quantitatively hydroxylated monacolin L to J, and molecular oxygen was required for the hydroxylation. The enzyme was located in the microsomal fraction and specific for NADPH. The enzyme activity was inhibited by metyrapone, carbon monoxide, sulfhydryl reagents and cytochrome c. The results indicate that monacolin L is the precursor of monacolin J, and that a monooxygenase is involved in this reaction.

Ascomycota↗
PubMed1988

[A case of aorto-enteric fistula after reconstruction of an abdominal aortic aneurysm associated with Behçet's disease and special reference to 95 reported cases in Japan].

A 45-year-old male with incomplete type of Behçet's disease was operated on because of abdominal aortic aneurysm. The post-operative course was uneventful. On twenty-one months after discharge, the patient noticed left leg pain and tarry stool, and was referred to our hospital. Computed tomography and angiography showed aorto-enteric fistula at the proximal aortic anastomotic site. Aortic reconstruction was performed, but the patient died on 36th post-operative day. We analysed the reports of 95 cases of aneurysm associated with vasculo-Behçet's disease in Japan. This series comprised 82 men, 9 women and 4 unknowns. The cases were classified to four groups, which were incomplete type (48 cases), complete type (27 cases), suspected type (12 cases) and unknown (8 cases). They had 46 aortic aneurysms and 108 peripheral aneurysms. Operation was performed on 29 aortic aneurysms and 73 peripheral aneurysms. Eleven aortic aneurysms and twelve peripheral aneurysms had anastomotic complication post-operatively. Four cases after reconstruction of abdominal aortic aneurysm was complicated with aorto-enteric fistula. They were all dead post-operatively. Vasculo-Behçet's disease with aortic aneurysm is comparatively a rare entity and morbidity and mortality is high because of its etiological characteristics.

Aorta, Abdominal↗
PubMed1987

Purification and properties of collagenase from a Streptomyces species.

A collagenase active against native, insoluble collagen was isolated from the culture filtrate of a streptomycete which has been designated Streptomyces sp. C-51. Collagenase was produced by growing this strain in media containing gelatin. Purification by ammonium sulfate fractionation and chromatographies on DEAE-Toyopearl and DEAE-Cellulofine columns produced active enzyme which was free of contaminating proteins, including nonspecific proteinases, but which contained two active subspecies (I and II). Both subspecies were purified by preparative slab gel electrophoresis. The apparent molecular weights were 100,000 for the homogeneous fraction I and 90,000-110,000 for the microheterogeneous fraction II. These two subspecies were most active at pH 8-9, very similar in amino acid composition and immunologically identical. Some other properties of the Streptomyces C-51 collagenase were compared with those of Clostridium histolyticum collagenase. Substrate specificity, insensitivity to N-ethylmaleimide and diisopropyl fluorophosphate, and sensitivity to certain metal ion complexing agents were similar for the collagenases from both microorganisms.

Amino Acids↗
PubMed1986

Evaluation of sodium and potassium pump activity and number in diabetic erythrocytes.

The Na+,K+-ATPase (= Na pump), which produces the concentration gradient of Na+ and K+ across the cell membrane, was studied in diabetic erythrocytes. The activity and number of Na pumps, which are functional and quantitative expression of the Na+,K+-ATPase in erythrocytes, were measured by ouabain-sensitive 42K or 43K influx and by [3H]ouabain binding, respectively. The turnover rate of the pumps was calculated from the two measurements to evaluate in situ activity of the pump. The Na pump activity was found to be higher in the diabetic (193 +/- 12 nmol K+/h . 10(9) cells) than in the normal group (164 +/- 6) (P less than 0.05), though the affinities of the pump for extracellular K+ were not different. The number of Na pumps and the Kd of the pumps for ouabain in the diabetic group were not significantly different from those in the normal group (354 +/- 12 site/cell and 4.33 +/- 0.20 nM). The turnover rate of the diabetic group tended to be higher than that of the normal group. The rate was about one third of the molecular activity reported for Na+,K+-ATPase under optimum conditions. These results indicate that the enzymatic properties as well as the number of Na pumps were not altered in diabetic erythrocytes despite the increased Na pump activity. Therefore the increased activity of the erythrocyte Na pump in diabetes mellitus suggests an increase of cation permeability associated with a possible disorder in the diabetic membrane.

Adolescent↗
PubMed1982

Effect of a glucosyltransferase inhibitor on glucan synthesis and cellular adherence of Streptococcus mutans.

The effects of mutastein, a glucosyltransferase inhibitor derived from an Aspergillus terreus strain, on the glucan synthesis by glucosyltransferases of Streptococcus mutans and sucrose-dependent adherence of S. mutans cells were examined in vitro. The synthesis of insoluble glucan by crude glucosyltransferase of S. mutans strain B13 was markedly inhibited by mutastein at a final concentration of 10 micrograms of protein/ml. The synthesis of insoluble glucan adherent to glass surfaces was almost completely inhibited by mutastein at this concentration. In addition, mutastein inhibited the sucrose-dependent adherence to glass surfaces of resting and growing cells of various S. mutans strains. These results suggest that mutastein could be useful for controlling dental plaque and dental caries in vivo.

Adhesiveness↗
PubMed1978

Transport of nicotinamide adenine dinucleotide in an unc mutant of Escherichia coli.

The presence and some properties of an NAD+ transport system were examined in PA5, a Mg, Ca-ATPase [EC 3.6.1.3]-defective mutant strain of Escherichia coli W2252. NAD+ uptake was stimulated by exogenous energy sources and dependent on external substrate concentrations with an apparent Km of about 25 micrometer. Most of the radioactivity from [14C]-NAD+ accumulated in the cells was identified as NAD+. [14C]NAD+ uptake was competively inhibited by unlabeled NAD+, NADP+, NMN+ or nicotinamide. Similar uptake activity was also observed in W2252.

Biological Transport↗