Search PubMed⌕ Search

Biomedical subjects

M Hamada

Publications and source records attributed to M Hamada.

At least 595 records · Page 33Linked to original sources
PubMed1981

An aberrant adenylate kinase isoenzyme from the serum of patients with Duchenne muscular dystrophy.

The sera from patients with human Duchenne (X-linked) progressive muscular dystrophy contain elevated adenylate kinase (ATP: AMP phosphotransferase, EC 2.7.4.3) activities, in addition to their characteristically high creatine kinase (ATP; creatine N-phosphotransferase, EC 2.7.3.2) activities. By agarose gel electrophoresis of human Duchenne dystrophic serum, the presence of an apparently normal human serum adenylate kinase together with a variant species of adenylate kinase was detected. The latter enzyme species appeared, in its mobility, to be similar to that of the normal human liver-type adenylate kinase. The presence of this aberrant liver-type adenylate kinase could also be demonstrated by characteristic (for the liver type) inhibition patterns with P1,P5-di-(adenosine-5')pentaphosphate, 5,5'-dithiobis(2-nitrobenzoate) and phosphoenolpyruvate. On the other hand, by inhibition titrations with an anti-muscle-type adenylate kinase, hemolysates from the erythrocytes of several Duchenne and Becker's dystrophics were found to contain approx. 96% muscle-type adenylate kinase and their serum approx. 97% muscle-type adenylate kinase. These same patients contained approx. 89% M-M type creatine kinase in their serum (by inhibition against anti-human muscle-type creatine kinase) indicative of the presence also of M-B plus B-B type active isoenzymes. All of these data can best be explained by the presence of a variant or mutant adenylate kinase isoenzyme in the dystrophic serum. This isoenzyme appears to resemble the liver type in its inhibition patterns with P1,P5-di(adenosine-5')pentaphosphate, 5,5'-dithiobis(2-nitrobenzoate) and phosphoenolpyruvate, and in its heat stability (compare also the agarose gel electrophoresis pattern); but structurally, it is a muscle type, or derived from a muscle type, as shown immunologically by inhibition reactions with anti-muscle-type adenylate kinase. Whether this is a fetal-type isoenzyme of adenylate kinase will require further investigation.

Adenine Nucleotides↗
PubMed1981

Shoshin beriberi with severe metabolic acidosis.

A case of Shoshin beriberi found in a patient with severe metabolic acidosis and shock was presented. We believe the metabolic acidosis in this case is ascribable to overproduction of pyruvate and lactate resulting from lack of thiamine due to preferential intake of sake, precooked food, and rice, and also to shock. The hemodynamic studies done after recovery from shock revealed that the cardiac output, which was initially high, decreased to a slightly low level and then increased to a normal level, concomitant with an increase in the peripheral vascular resistance after introductory administration of thiamine. After treatment with thiamine, all abnormalities disappeared.

Acidosis↗
PubMed1981

Scintigraphic evaluation of regional pulmonary circulation and ventilation abnormalities in mitral valvular disease and congestive heart failure.

Regional pulmonary mean transit time, MTT (RV-Lung) was measured by radionuclide angiography using 99mTc-pertechnetate or 99mTc-HSA. In 8 normal subjects, MTT (RV-Lung) in upper (U) and lower (L) lung fields averaged 2.48 and 2.81 sec, respectively. In MS and CHF groups, MTT (RV-Lung) in L was markedly prolonged (5.04 and 5.10 sec, respectively) and after appropriate medical or surgical treatment, MTT in L markedly reduced. Pulmonary ventilation perfusion scintigraphy with 133Xe was performed in 18 patients with MS. Both Vu/L and Ou/L increased in accordance with the severity of disease, however, Vu/L had never exceeded unity. The estimation of regional MTT in the lung field is to be useful way in evaluating the severity of pulmonary circulatory disturbance in MS or in congestive heart failure.

Adolescent↗
PubMed1981

Syntheses of 9-substituted josamycin, 13-substituted isojosamycin and their tetrahydro derivatives.

Derivatives of josamycin and isojosamycin modified at C-9 and C-13 have been prepared by reaction sequences involving treatment of josamycin with alcohols, phenol or 1-methyl-1H-tetrazol-5-ylthiol in acidic media. Several tetrahydro derivatives of josamycin and isojosamycin have also been prepared by reaction sequences involving catalytic hydrogenation. From the 1H NMR studies, it was found that the conformation of the macro-lactone portion of 13-O-methylisojosamycin dimethylacetal, a key intermediate, is flexible and changeable with variation of the solvent.

Anti-Bacterial Agents↗
PubMed1981

Biochemical study of R-75-1, a new semi-synthetic rifamycin.

A new derivative of rifamycin SV, R-75-1, inhibits RNA synthesis in Mycobacterium smegmatis ATCC 607 (M607) at a concentration 10 times lower than rifampicin (RFP). However, both R-75-1 and RFP inhibit RNA polymerase reaction by 50% at the same concentration level (0.05 approximately 0.1 microgram/ml). Both inhibit the initiation process of RNA synthesis. E. coli RNA polymerase of the RFP-resistant strain was resistant to R-75-1. RFP was not inactivated by M607 cell extracts. The inhibitory effect of R-75-1 is markedly diminished if mycobacteria are grown in the medium containing Tween 80. On the basis of these results, the greater activity of R-75-1 to mycobacteria is suggested to be due to the better permeability than RFP.

Bacteria↗