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Biomedical subjects

N Azuma

Publications and source records attributed to N Azuma.

156 records · Page 9Linked to original sources

Calcium sensitivity of abalone, Haliotis discus, myosin.

Superprecipitation was observed with abalone myosin and purified rabbit actin in the presence of calcium ions, but was not observed in the absence of calcium. The Mg-ATPase [EC 3.6.1.3] activity of abalone myosin and rabbit actin in the absence of calcium ions (EGTA present) showed about 60% inhibition as compared with values in the presence of calcium ions. The calcium sensitivity may be attributable to abalone myosin, as in the case of scallop myosin.

Actins↗

Myosin from molluscan abalone, Haliotis discus. Isolation and enzymatic properties.

Actomyosin was extracted from smooth muscle of molluscan abalone with 0.1 M PPit pH 6.4. Myosin was separated from the actomyosin by centrifugation at 100,000 X g in the presence of 5 mM ATP and 10 mM MgCl2. Myosin in the supernatant was further purified by gel filtration on a Sepharose 4B column. Paramyosin contamination of the actomyosin preparation interfered with the isolation of myosin and complete removal of actin and paramyosin from the myosin has not been accomplished. The myosin appeared to consist of a single f-chain and a single g-chain, as examined by SDS-disc electrophoresis in 8 or 13.7% acrylamide gel. The ATPase [EC 3.6.1.3] activity of this myosin in 0.5 M KCL at neutral pH and at 0 degrees was rather unstable and decreased by 10-20% per day. The effects of rho-chloromercuribenzoate and EDTA on the ATPase activity were similar to those observed with other smooth muscle myosin but the dependence upon pH or KCL concentration was different.

Adenosine Triphosphatases↗

Histological findings in asymptomatic hepatitis C virus carriers.

There is controversy about clinical management of individuals who persistently have hepatitis C virus antibodies (HCVAb) but who have no symptoms or signs of liver disease. Liver biopsy samples were taken from 15 individuals, all of whom had normal alanine aminotransferase (ALT) levels, to determine the prevalence of liver disease and whether HCVAb and HCV-RNA correlate with histological findings. Eleven patients with hepatitis C viremia had histological evidence of chronic hepatitis on biopsy. On the other hand, four HCV-RNA-negative individuals had almost normal liver histology. These findings indicate that serum HCV-RNA is a sensitive and specific marker of liver disease in HCVAb-positive subjects, independent of ALT levels. Furthermore, these results suggest that there are very few histologically healthy carriers of HCV among HCV-RNA-positive individuals.

Aged↗

Measurement of peritoneal dialysate volume by CT.

Three-dimensional (3-D) graphic reconstruction of serial image data of x-ray CT on three dialysis patients was studied to measure peritoneal dialysate (PD) volume. Volume estimation with a surface reconstructed model provided a 16% error; a 35% error was found with a voxel model, although the total time required by the voxel model was 15 times less.

Aged↗