Biomedical subjects

N Taniguchi

Publications and source records attributed to N Taniguchi.

At least 541 records · Page 30Linked to original sources

PubMed1987

Glutathione disulfide-stimulated Mg2+-ATPase of human erythrocyte membranes.

Inside-out erythrocyte membranes attached to polycationic beads manifested glutathione disulfide (GSSG)-stimulated ATPase activity. A Lineweaver-Burk plot of the ATPase activity as a function of GSSG concentration was biphasic and gave apparent Km values of 0.13 mM and 2.0 mM. These kinetics are similar to those reported for the ATP-requiring GSSG-transport systems in human erythrocytes and for the GSSG-stimulated ATPase activity in the plasma membranes of rat hepatocytes. Erythrocyte membranes that were depleted of extrinsic proteins were solubilized in 0.5% Triton X-100. Affinity chromatography on S-hexylglutathione-Sepharose 6B, with elution by a linear gradient of S-hexyl-glutathione, resulted in the resolution of two peaks of enzyme activity. One enzyme, which was eluted at approximately 0.5 mM S-hexylglutathione, had a high affinity for GSSG (apparent Km of 150 microM) and for ATP (80 microM). The other enzyme, which was eluted at approximately 1 mM S-hexylglutathione, had a low affinity for GSSG (apparent Km of 2.0 mM) and ATP (140 microM). GSSG-independent Mg2+-ATPase, Ca2+-dependent Mg2+-ATPase and Na+, K+-dependent Mg2+-ATPase were undetectable in the fractions. Addition of Ca2+, ouabain, or vanadate neither activated nor inhibited the activities, further indicating that the enzymes are distinguishable from ion-pumping ATPases. The enzymes required GSSG for activation; reduced glutathione (GSH) was ineffective. The ATPase activity of the high-Km enzyme was inhibited by addition of p-chloromercuribenzoate, N-ethylmaleimide, and iodoacetamide and was activated by treatment with dithiothreitol, whereas the ATPase activity of the low-Km enzyme was not modified by these thiol reagents. The properties of the enzymes are similar to those of ATP-dependent GSSG-transport systems in human erythrocytes, suggesting that these ATPases may function in the active transport of GSSG.

Ca(2+) Mg(2+)-ATPase↗

PubMed1987

Systemic amyloidosis with a mesenteric mass which had the appearance of proteinaceous lymphadenopathy.

An autopsy case of systemic amyloidosis in a 46-year-old Japanese female who had M component in sera but no manifestations of myeloma is described. Autopsy revealed massive milky ascites and a large mesenteric mass, which showed histologically perivascular concentric deposition of eosinophilic materials with mixture of residual follicles and scattered plasma cells. These morphological findings closely resembled those seen in proteinaceous lymphadenopathy, and the material in the mesenteric mass proved to be an amyloid A lambda protein. Subsequent immunohistochemical observations strongly suggested that this mass lesion was a "burnt-out" plasmacytic dyscrasia.

Amyloidosis↗

PubMed1987

Maternal blood distribution of zinc and copper during labor and after delivery.

In 15 normal mothers the stress effects of labor on zinc and copper distributions in erythrocytes and plasma were investigated. Lower levels of total zinc and of zinc derived from both carbonic anhydrase isoenzymes (CA-I and CA-II), especially from CA-I, in erythrocytes were obtained immediately after delivery. On the other hand, there was a significant increase in total plasma zinc concentration only on admission to hospital in labor, although albumin-bound zinc concentration remained elevated throughout the entire labor. These results suggest that there are unexplained disparities between the changes in zinc levels in maternal erythrocytes and plasma during labor.

Adult↗

PubMed1987

gamma-Glutamyl transpeptidase in rat liver during 3'-Me-DAB hepatocarcinogenesis: immunohistochemical and enzyme histochemical study.

Immunohistochemical localization of gamma-glutamyl transpeptidase (gamma-GTP) in rat liver during 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) hepatocarcinogenesis was investigated and compared with sites of gamma-GTP activity. Immunohistochemically, gamma-GTP was stained in the apical border of proliferating oval cells during the early stages of azo-dye carcinogen feeding. After 7 weeks, multiple hyperplastic nodules appeared in which gamma-GTP was localized in the bile canaliculi. In hepatoma tissues, positive staining for gamma-GTP was observed in the bile canaliculi-like spaces, on the cell membrane, and sometimes in the cytoplasm of malignant cells. Enzyme histochemical staining showed gamma-GTP activity to be present in almost the same areas as the immunoreactive gamma-GTP. However, some areas adjacent to hepatoma tissue showed immunohistochemically reactive protein but no enzyme activity. Immunoreactive gamma-GTP was present in all locations at which enzyme activity was seen. The present data suggest that an altered form of gamma-GTP might be present in tissues during 3'-Me-DAB hepatocarcinogenesis.

Animals↗

PubMed1987

Comparative distribution kinetics of cefazolin and tobramycin in children.

The time courses of drug concentration in serum after i.v. drip infusion of 2 mg/kg of tobramycin and 25 mg/kg of cefazolin in children were analyzed by model-independent moment analysis. The volume of distribution at the steady state per body weight (Vdss/BW) of tobramycin was in the range of 212 to 335 ml/kg and that of cefazolin was 119 to 156 ml/kg. A plot of the differences of Vdss/BW obtained in the same child for tobramycin and cefazolin against the value of Vdss/BW of tobramycin gave a linear regression line (r = 0.971). The magnitude of Vdss (1) of tobramycin could be well interpreted as corresponding to the extracellular water volume. In the case of cefazolin, the extracellular water space accounts for about 60% of the total distribution volume. The remaining 40% of the total Vdss of cefazolin was considered to be accounted for by the disposing organs.

Blood Proteins↗

PubMed1987

Effects of treadmill exercise on platelet function, blood coagulability and fibrinolytic activity in patients with atrial fibrillation.

The effects of treadmill exercise on platelet function, blood coagulability and fibrinolytic activity were evaluated in 20 patients with lone atrial fibrillation (AF) and 15 age-matched normal controls (normals). Multistage treadmill exercise up to 85% of the predicted maximal heart rate was performed, and blood for measurements was obtained pre-exercise, and immediately and 6 min post-exercise. There was an increase in the platelet sensitivity to ADP-aggregation after exercise in both groups. Pre-exercise plasma beta-thromboglobulin (beta-TG) levels were higher in AF than in normals. Beta-TG increased after exercise in both groups (immediate post-exercise; 35.1 ng/ml for normals and 62.8 ng/ml for AF), and the increase was greater in AF than in normals. PT and APTT shortened, and plasma fibrinogen levels increased after exercise in both groups. Pre-exercise levels of plasma ATIII and protein C were lower in AF than in normals. These two proteins increased after exercise in both groups. However, the increase was greater in normals. Plasma alpha 2-PI increased after exercise in both groups; the level was lower in AF than in normals at each exercise stage. In conclusion, enhanced platelet activity, and lower levels of anticoagulant and antifibrinolytic activity were observed in AF not only at rest but also after treadmill exercise. These changes might reflect the hypercoagulable state in patients with AF. It is speculated that the risk of thromboembolic complications may be enhanced with exercise in AF patients.

Adenosine Diphosphate↗

PubMed1987