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Biomedical subjects

T Moriyama

Publications and source records attributed to T Moriyama.

At least 271 records · Page 15Linked to original sources
PubMed1987

Serum levels of bone Gla-protein in normal humans and in patients with chronic renal failure.

Levels of serum bone Gla-protein (BGP) were evaluated in 372 normal Japanese subjects (164 males, 208 females), ranging in age from 14 to 87 years, and in 194 patients with chronic renal failure, 181 of whom were on maintenance hemodialysis. The age-dependent serum BGP levels (mean +/- SD) determined by radioimmunoassay in normal subjects under 20 years old were 27.1 +/- 20.5 ng/ml, and 10.2 +/- 5.8 ng/ml in older subjects. Mean serum BGP increased significantly in patients with hemodialysis (35.1 +/- 24.3 ng/ml) and in patients with nonhemodialysis chronic renal failure (20.6 +/- 14.2 ng/ml). The mean BGP levels showed a trend toward higher values in the younger renal failure patients. However, the difference to the values of older patients did not reach a level of statistical significance. There was a significant (r = 0.84, p less than 0.001) positive correlation between serum BGP and serum creatinine for the nonhemodialysis group alone, but not for hemodialysis patients alone. A correlation was also observed between serum BGP and serum C-PTH in hemodialysis patients. Our results suggest that the serum BGP elevation in patients with chronic renal failure probably reflects not only decreased renal clearance but also increased bone formation.

Adolescent↗
PubMed1986

Mitochondrial aspartate aminotransferase linked to immunoglobulin G of the kappa-lambda type: report of a case.

Macromolecular aspartate aminotransferase (L-aspartate: 2-oxoglutarate aminotransferase EC 2.6.1.1, AST) was found in the serum of a patient with benign hypertension. The serum total AST and mitochondrial AST (mAST) activities were proportionately higher. The abnormal AST was found to be a macromolecular complex composed of mAST and immunoglobulin G of the kappa-lambda type. The dissociated IgG from the complex was shown to combine with human and rat mAST, but not with cytosolic AST of both species. Molecular mass of the macromolecular AST was estimated to be 360,000 Da. These results indicate that the complex may consist of one IgG molecule associated with two mAST molecules. By the method of papain digestion the binding site of immunoglobulin in the complex appeared to be located in the Fab portion of the IgG molecule. This finding strongly suggests that the AST-immunoglobulin complex is a specific antigen-antibody complex.

Adult↗
PubMed1986

Chemical mutations of the catalytic carboxyl groups in lysozyme to the corresponding amides.

In a two-step process, esterification and ammonolysis, Glu-35 and Asp-52 in lysozyme were amidated to glutamine and asparagine residues. Since the side chains of glutamine and asparagine are almost equal in size to those of glutamic acid and aspartic acid, these conversions would provide appropriate derivatives to elucidate the catalytic participations of these residues. The enzymatic activities of the resulting [Gln35]lysozyme and [Asn52]lysozyme were found to be less than 4% of that of native lysozyme in a pH range of 3.4-8.0. As these derivatives were inactive, we could determine the dissociation constants (Ks values) for the binding of beta-1,4-linked n-mer, a hexasaccharide of N-acetyl-D-glucosamine, to [Gln35]lysozyme and [Asn52] lysozyme. The values of Ks at pH 5.5 and 40 degrees C were 1.6 X 10(-5) M for [Gln35]lysozyme and 2.7 X 10(-5) M for [Asn52]lysozyme. These values are similar to that for native lysozyme. The results are direct proof for the involvements of Glu35 and Asp52 in the catalytic action of lysozyme. A method for ammonolysis of ester groups in proteins in liquid ammonia is described and will be useful for amidation of carboxyl groups of proteins.

Amino Acids↗
PubMed1986

Gentamicin inhibits Na+-dependent D-glucose transport in rabbit kidney brush-border membrane vesicles.

We studied the effect of gentamicin on Na+-dependent D-glucose transport into brush-border membrane vesicles isolated from rabbit kidney outer cortex (early proximal tubule) and outer medulla (late proximal tubule) in vitro. We found the same osmotically active space and nonspecific binding between control and gentamicin-treated brush-border membrane vesicles. There was no difference in the passive permeability properties between control and gentamicin-treated brush-border membrane vesicles. Kinetic analyses of D-glucose transport into 1 mM gentamicin-treated brush-border membrane vesicles demonstrated that gentamicin decreased Vmax in the outer cortical preparation, while it did not affect Vmax in the outer medullary preparation. With regard to Km, there was no effect of gentamicin in any vesicle preparation. When brush-border membrane vesicles were incubated with higher concentrations of gentamicin, Na+-dependent D-glucose transport was inhibited dose-dependently in both outer cortical and outer medullary preparations. Dixon plots yield inhibition constant Ki = 4 mM in the outer cortical preparation and Ki = 7 mM in the outer medullary preparation. These results indicate that the Na+-dependent D-glucose transport system in early proximal tubule is more vulnerable to gentamicin toxicity than that in late proximal tubule.

Animals↗
PubMed1986

Association between vibration-induced white finger and hearing loss in forestry workers.

The present investigation was a case-referent study in which age and hours of vibrating tool operation were matched for the cases and referents in an effort to confirm the earlier reported difference in hearing loss between workers with vibration-induced white finger (VWF) and those without VWF. Thirty-seven pairs were formed from 51 men with VWF and 228 without it. The greatest hearing loss was at 4 kHz in both the case and reference groups, as is usually found in typical noise-induced hearing loss. The case group had a higher hearing threshold than the reference group at every frequency, and the difference was significant at 4 and 8 kHz and almost so at 2 kHz. As corroboration for this association, the subjects were divided into three groups by recovery rate of skin temperature 5 min after cold provocation at 10 degrees C for 10 min, a procedure which is one of the valid objective tests for VWF. The subjects with the most delayed recovery reached the highest age-corrected median hearing level at 4 kHz, and those with the promptest recovery marked the lowest. The cause of this increased damage of hearing in relation to VWF is not known. However, the association between VWF and hearing loss is interesting in view of the effects of vibration on parts of the body other than the hand and arm.

Female↗
PubMed1986

Usefulness of fingertip skin temperature for examining peripheral circulatory disturbances of vibrating tool operators.

The data on skin temperature obtained in a cold provocation test (immersing one hand in water at 10 degrees C for 10 min) were analyzed to confirm their usefulness for examining the peripheral circulatory functions of vibrating tool operators. Under room temperatures from 20 to 23 degrees C in winter, the skin temperatures after the end of provocation of the VWF (vibration-induced white finger) group were generally significantly lower than those of the age-matched non-VWF and reference groups, and the non-VWF operators with over 5,000 h of chain-saw experience showed significantly lower skin temperatures 5 and 10 min after provocation than the age-matched referents. In this study skin temperature was used as a screening test for VWF. The highest sensitivity (91.1%) was obtained at 19.0 degrees C at the fifth minute after the end of the provocation, and the highest specificity (93.3%) at 15.5 degrees C at the third minute after provocation, both the sensitivity and specificity being over 70% and the correct diagnosis rate being over 80% among the screening levels.

Cold Temperature↗
PubMed1985

An association between Raynaud's phenomenon and hearing loss in forestry workers.

Forestry workers using chain saws run the risk of both vibration disease and noise-induced hearing loss. It was reported that people with Raynaud's phenomenon of occupational origin had more severe hearing loss than those without it. A possibility of confounding due to age and duration of noise exposure from the tools remained unsolved, however. A matched pair case-control study was conducted to eliminate such confounding. Forestry workers operating chain saws, bush cleaners and/or winches were investigated. For 37 men with Raynaud's phenomenon a control was chosen from those unaffected whose age and operating hours for the tools were almost equal to those of the cases. Good matching was achieved for age and for total hours of work with the tools. The cases had higher median hearing threshold than the controls at every frequency. The difference was significant (p less than 0.05) at 4 and 8 kHz and almost significant at 2 kHz (p not equal to 0.06). According to our classification of the audiogram, the cases had more advanced types of noise-induced hearing loss than did the controls. Thus, an association between Raynaud's phenomenon and hearing impairment in forestry workers handling chain saws and/or other tools was found to persist even after the effect of age and exposure time was eliminated.

Adult↗