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Biomedical subjects

N Taniguchi

Publications and source records attributed to N Taniguchi.

At least 721 records · Page 40Linked to original sources

alpha-glucosidase activity in human leucocytes: choice of lymphocytes for the diagnosis of Pompe's disease and the carrier state.

alpha-Glucosidase activity was assayed in polymorphonuclear cells and lymphocytes from human peripheral blood with 4-methylumbelliferyl-alpha-D-glucopyranoside as substrate in the presence of sodium taurocholate. The pH vs. activity curve of the alpha-glucosidase indicated that differential estimation between acid and neutral alpha-glucosidases was difficult to perform with polymorphonuclear cells, but easily accessible with lymphocytes. The use of peripheral blood lymphocytes for the enzymatic diagnosis of Pompe's disease seemed to be more reliable than the use of whole leucocytes; this also the case with a classical Pompe's patient. The lymphocytes from the parents had normal or low normal activity of acid alpha-glucosidase in the freshly isolated state, but when cultured with phytohaemagglutinin for 72 h, the stimulated lymphocytes of both parents showed about half the enzyme activity of the cultured controls. It was deemed possible in all probability to identify the carrier state by assay of the enzyme activity in phytohaemagglutinin-stimulated lymphocytes.

Adult↗

gamma-Glutamyl cyclotransferase from rat kidney. Sulfhydryl groups and isolation of a stable form of the enzyme.

gamma-Glutamyl cyclotransferase, highly purified from rat kidney, contains several readily accessible sulfhydryl groups whose modification appears to be associated with the appearance of multiple enzyme forms as determined by isoelectric focusing and ion exchange chromatography. The enzyme was obtained in a 1000-fold purified and apparently homogeneous form by a procedures involving treatment with dithiothreitol followed by chromatography on thiol-Sepharose. The enzyme was also isolated in a highly active, apparently homogeneous, and stable form after reduction and treatment with iodoacetamide. The amino acid compositions and other properties of the two forms of the enzyme were very similar. Studies on the activity of the enzyme toward a variety of gamma-glutamyl amino acids and di-gamma-glutamyl amino acids showed that the enzyme is much more active toward certain di-gamma-glutamyl amino acids than toward the corresponding gamma-glutamyl amino acids; thus, the preferred substrates have the general structure gamma-Glu-gamma-Glu-NH-R in which the nature of the R moiety has relatively little effect on activity.

Acyltransferases↗

Mitochondrial fraction of serum glutamic-oxaloacetic transaminase in Duchenne muscular dystrophy.

The mitochondrial fraction of serum glutamic-oxaloacetic transaminase was measured in the serum of 50 patients with Duchenne muscular dystrophy by an immunoadsorbent method. The enzyme activities in patients in the early, midstage, and late stages of the disease and controls were 21.8 +/- 7.4 (N=9), 12.2 +/- 3.7 (N=38), 6.4 +/- 1.2 (N=3) and 4.2 +/1 1.2 units/ml (N=15), respectively. The enzyme level in the early stage was significantly elevated (p less than 0.01, vs. control, p less than 0.05 vs. mid stage). As the disease progressed, the levels gradually declined, but mid-stage values were still higher than the late stage (p less than 0.01) or control values (p less than 0.01). In the late stage, enzyme activity was within the control range.

Adolescent↗

Effect of thyroid hormone on the levels of erythrocyte carbonic anhydrase isozymes and 2,3-diphosphoglycerate in rabbits.

Levels of rabbit erythrocyte carbonic anhydrase B and C isozymes were determined in experimental hyperthyroidism using a quantitative immunologic technique. Levels of erythrocyte 2,3-diphosphoglycerate and protein binding iodine were simultaneously determined. Thyroxine and 3,5,3'-triiodothyronine were administered to rabbits orally for 30 days. A significant decrease in carbonic anhydrase B type was observed after 30 days, although no significant change was observed in carbonic anhydrase C type. These findings suggest that the steady state level of carbonic anhydrase B type in red cells is affected by thyroid hormone more readily than that of carbonic anhydrase C type. The level of red cell 2,3-diphosphoglycerate increased markedly after 10 days of treatment, corresponding to the increase of protein binding iodine. The clinical or pathologic significances were discussed in relation to the changes in the levels of these isozymes and 2,3-diphosphglycerate in red cells.

Animals↗

Transient increase of IgG Fc receptor-bearing T lymphocytes following positive PPD skin testing.

In tuberculin-sensitive individuals, IgG Fc receptor (FcR)-bearing lymphocytes in the peripheral blood increased transiently following PPD-tuberculin skin test. This rise in circulating FcR-bearing cells appeared to peak about 36--48 h after the intradermal inoculation of PPD and seemed to occur largely in the T cell population. Skin test-negative individuals showed no significant changes in their circulating FcR-bearing cells following PPD inoculation. Peripheral blood lymphocytes from PPD-sensitive individuals were fractionated into non-T cell and T cell-enriched populations by E rosette sedimentation technique. FcR-bearing cells in the T cell-enriched population were eliminated by EA rosette sedimentation: i.e. FcR-negative T cells. Then, equal numbers (1 X 10(5) cells each) of non-T cells and unfractionated or FcR-negative T cells were recombined in culture. Prior to PPD inoculation, there was no significant difference between these two cell mixtures in the in vitro cellular response to PPD or mitogens. When these cell populations were obtained 36--48 h after PPD inoculation, however, the combination of non-T cells and FcR-negative T cells responded to PPD much better than the combination of non-T cells and unfractionated T cells, whereas the mitogen-induced cellular proliferation of these two cell mixtures did not differ from each other.

Adult↗

Inactive form of erythrocyte carbonic anhydrase B in patients with primary renal tubular acidosis.

Evidence was found for an inactive form of carbonic anhydrase type B in the erythrocytes of two children with primary renal tubular acidosis. The addition of zinc chloride to hemolysates from these patients resulted in a marked increase in the activity of this enzyme. No such effect was noted with hemolysates of control subjects. No significant differences were observed in the zinc levels of hemolysates of these patients and of normal individuals. However, the level of zinc in the carbonic anhydrase B isolated from one of these patients was low, suggesting a modified form of the enzyme. The restoration of activity upon the addition of zinc was reversed by ethylenediamine tetraacetate, but no such effects were noted for the carbonic anhydrase B of normal individuals. Thus the abnormal carbonic anhydrase B has decreased zinc binding. The ultraviolet difference spectrum of the carbonic anhydrase B of normal individuals and that of a patient showed a peak at 305 nm which decreased upon the addition of zinc. The abnormal form of carbonic anhydrase B was not distinguishable from that of normal individuals by either immunological or electrophoretic criteria.

Acidosis, Renal Tubular↗

Effect of physical exercise on the activity of GOT isozyme in human plasma.

Untrained healthy male volunteers were subjected to the study on the effects of exercise (bicycle ergometer, 920 kpm/min for 30 min) upon GOT isozyme (supernatant GOT, s-GOT and mitochondrial GOT, m-GOT) activities in plasma. Significant increases in the levels of both s-GOT and m-GOT activity were observed after the exercise (p less than 0.001). After 30 min of rest m-GOT activity almost returned to its preexercise value. However, s-GOT activity did not return to its preexercise activity. The changes in the activity of GOT isozyme after physical exercise are discussed.

Adolescent↗

A study on the toxicity of natural food dyes--toxicity and enzyme inhibition in Paramecium caudatum.

The toxicity of 14 commercial natural dyes which are widely used as food additives in Japan was studied on Paramecium caudatum. Laccaic acid and capsanthin were found to be very toxic to Paramecium caudatum. Some of the commercially available carminic acid and crocin were also toxic. The inhibitory effect of natural food dyes on leucine aminopeptidase, acid phosphatase and esterase in vitro was proportional to the toxic effect of the dyes on the survival time of Paramecium caudatum. Analyses of the commercial natural food dyes by high performance liquid chromatography failed to identify the toxic components.

Acid Phosphatase↗

Effect of CO2 on carbonic anhydrase activity and isozyme levels in respiratory failure.

The activity and the isozyme B and C levels of red cell carbonic anhydrase was examined before and during CO2 inhalation in 18 patients with chronic respiratory failure. Carbonic anhydrase B and C levels did not change during 5 min breathing of high (8-9%) and low (3-5%) CO2 mixture. Carbonic anhydrase activity decreased in patients with combined hypercarbia (Paco2 greater than or equal to 45 mmHg) and hypoxemia (Pao2 less than or equal to 60 mmHg). This was accompanied by an increase in red cell K+ content, 2, 3-DPG and Hct/Hb. The activity did not change in patients with only hypoxemia. Carbonic anhydrase activity and plasma HCO-3 concentration were positively correlated (r = 0.4, P less than 0.05). A significant inverse correlation was also found between changes in red cell K+ content and those in carbonic anhydrase activity (r = - 0.42, P less than 0.05). These results indicate that 1), there is a dissociation between activity and isozyme levels in red cell carbonic anhydrase during the initial 5 min of CO2 breathing in patients with combined hypercarbia and hypoxemia, and 2), there seems a linkage exists between K+ movement across the red cell membrane and carbonic anhydrase activity.

Carbon Dioxide↗

Mitogenic responsiveness and monocyte-lymphocyte interaction of early and late rosette-forming cell populations of human peripheral blood lymphocytes.

Adherent cells in human peripheral blood mononuclear cells were removed by the attachment to the plastic surface of tissue culture dishes. After removal of adherent cells, early rosette-forming cells (early RFC), which were characterized by early (5 min) rosette formation with sheep blood cells (SRBC) at an SRBC to lymphocyte ratio of 8:1, were separated from nonrosetting cells by sedimentation on Ficoll-Hypaque gradient. Total (60 min) rosette formation was carried out with the early RFC-depleted cell population on the gradient interface by the use of neuraminidase-treated SRBC at an SRBC to lymphocyte ratio of 20:1 and the resulting rosette-forming cells (late RFC) were sedimented by gradient centrifugation. These T cell subpopulations, early RFC-enriched and late RFC-enriched, were reasonably pure with respect to the ability to bind SRBC and contained less than 0.5% monocytes. Monocyte preparations, which were obtained after vigorous washing of the adherent cell layers on tissue culture dishes, responded to phytohemagglutinin P (PHA-P) or concanavalin A (Con A) with negligible incorporation of 3H-thymidine. There was no significance difference in the responsiveness to PHA-P between early RFC-enriched and late RFC-enriched populations either in the absence or in the presence of graded numbers of additional autologous monocytes. However, the response of early RFC-enriched population to Con A was significantly poor as compared with that of late RFC-enriched one unless additional monocytes were added. In the presence of 20% autologous monocytes in the culture, the Con A-induced response of early RFC-enriched population was markedly enhanced to reach close to that of late RFC-enriched population. These results suggest that early RFC and late RFC might be different from each other in their responsiveness and in their need for monocytes on the stimulation with Con A.

Blood Cells↗

A solid-phase radioimmunoassay for human beta2-microglobulin.

A simple and relatively rapid as well as highly reproducible determination of beta2-microglobulin is described for general laboratory use. The method is based on a solid-phase radioimmunoassay paper discs as a solid-phase material. The assayable range is approximately in the range of 2 ng to 20 mug of beta2-microglobulin with a precision of approx. 5 percent. This assay requiring only 0.05 ml of urine can be completed within 20 h. Urine in cadmium-exposed workers and residents in cadmium-polluted districts including patients with itai-itai disease were examined and considerable amounts of beta2-microglobulin were observed in these urines.

Beta-Globulins↗

Inhibitory effect of sheep erythrocyte fragments on rosette formation of human T lymphocytes with sheep red blood cells.

The effect of sheep red blood cells (SRBC) fragments on rosette formation of human peripheral T lymphocytes with SRBC was evaluated on the active and total T-rosette tests. The rosetting capacity of active rosette-forming cells was selectively and nearly completely inhibited by the pretreatment of lymphocytes with SRBC fragments. The decrease in total rosettes by blocking with SRBC fragments was almost parallel to that of active rosettes. SRBC fragments had no inhibitory effect on the rosetting capacity of a lymphocyte population in which active rosette-forming cells were removed by gradient centrifugation. These results suggested that active rosette-forming cells in human T lymphocytes have the receptors of high affinity for SRBC and these receptors readily bind SRBC fragments, resulting in block of rosette formation.

Animals↗

Gamma-glutamyltransferase from azo dye induced hepatoma and fetal rat liver. Similarities in their kinetic and immunological properties.

Some properties of gamma-glutamyltransferase ((gamma-glutamyl)-peptide: amino-acid gamma-glutamyltransferase EC 2.3.2.2) from azo dye induced hepatoma and fetal rat liver were studied using kinetic and immunological criteria. There was no significant difference between the hepatoma enzyme and fetal rat liver enzyme in some of their catalytic properties. Antisera against the purified hepatoma enzyme also reacted to the fetal rat liver enzyme in the inhibition test and the precipitin reaction. A structural similarity between the hepatoma enzyme and fetal rat liver enzyme was observed and the acquirement of fetal characteristics in hepatoma was discussed.

Aging↗

Estimations of active and inactive carbonic anhydrase isozyme B in human red cells.

Human erythrocyte carbonic anhydrase isozyme B was measured by a specific and immunological method. The levels of carbonic anhydrase B were determined in normal subjects, patients with hyperthyroidism, and patients with chronic obstructive lung disease and patients with epilepsy under treatment with acetazolamide, using the rapid assay method of single radial immunodiffusion. The levels of carbonic anhydrase B showed a decrease in hyperthyroidism, and increased in chronic obstructive lung diseases and epilepsies. Closely negative correlations were observed between carbonic anhydrase B and T3 resin sponge uptake or protein bound iodine (PBI) levels in hyperthyroidism. Simultaneously, carbonic anhydrase B-dependent esterase activity (active carbonic anhydrase B enzyme) was determined kinetically using the immunoadsorbent method in the above-mentioned patients. The results were compared with the total enzyme protein (active and inactive carbonic anhydrase B enzyme), estimated by the single radial immunodiffusion technique. In patients treated with acetazolamide, the "true" specific activity of the carbonic anhydrase B (carbonic anhydrase B-dependent esterase activity/total carbonic anhydrase B protein) decreased remarkably. In chronic obstructive lung disease, no remarkable changes were observed. On the other hand the specific activity was elevated in hyperthyroidism to 2 times higher than that of normal subjects. The clinical significance of these active enzymes is discussed.

Acetazolamide↗