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Biomedical subjects

N Taniguchi

Publications and source records attributed to N Taniguchi.

At least 703 records · Page 39Linked to original sources

Bloom's syndrome in a Japanese girl.

Clinical, cytogenetic, and immunological data of a 5-year-old Japanese girl with Bloom's syndrome are described. Growth deficiency, photosensitivity, and a very mild facial telangiectatic erythema were present. Cytological studies revealed chromosomal aberrations and the characteristic high frequency in sister chromatid exchanges. Immunological studies showed that the serum levels of IgM and IgA, but not IgG, were abnormally low as compared to the age-matched control values and that the generation of cytoplasmic immunoglobulin-producing cells in the peripheral blood lymphocytes, which was evaluated in the in vitro pokeweed mitogen-stimulated cultures, was markedly reduced.

Abnormalities, Multiple↗

Purification and characterization of nucleoside diphosphatase from rat-liver microsomes. Evidence for metalloenzyme and glycoprotein.

Nucleoside diphosphatase was purified from rat liver microsomes more than 3000-fold with a 16% yield using a procedure including concanavalin-A--Sepharose and phenyl-Sepharose column chromatography. The purified enzyme had a specific activity of 2500 units/mg protein and appeared homogeneous by gel electrophoresis. The enzyme had a sedimentation coefficient of 6.5 S by sucrose-density gradient centrifugation. The enzyme had a sedimentation coefficient of 6.5 S by sucrose-density gradient centrifugation, and a Stokes' radius of 4.8 nm was estimated by the gel filtration technique. Its molecular weight is 130,000, but only one single band of Mr 65,000 was detected after sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The native enzyme seems thus to be composed of two identical subunits. The purified enzyme was confirmed to be a glycoprotein containing approximately 9% carbohydrates. The enzyme had a pH optimum of 7.5, an isoelectric point of 4.85 and a Km of 2.5 mM for UDP. On the basis of direct measurement of metal content in the native enzyme, the rat liver nucleoside diphosphatase was found to be a metalloenzyme containing 0.9 mol zinc and 0.1 mol manganese/mol 65,000-Mr subunit. Metal-free nucleoside diphosphatase has been prepared. The activity of the metal-free enzyme was restored by the addition of several divalent cations, zinc being the most effective.

Acid Anhydride Hydrolases↗

Neutralizing activity against Clostridium difficile toxin in the supernatants of cultured colostral cells.

Human colostral specimens were obtained from 60 Japanese postpartum women within the first 3 days after delivery. Neutralizing activity against Clostridium difficile toxin was evaluated with Y1 adrenal cells in miniculture. When Y1 adrenal cells were exposed briefly to the toxin, they showed a rounding response in culture, resembling that effected by Escherichia coli enterotoxin; however, preincubation of the toxin with aqueous phase of colostrum significantly reduced its cytopathic effect on Y1 adrenal cells. Of 60 colostral specimens, 17 samples had neutralizing activity against the toxin. Cell-free supernatants of colostral cells cultured for 7 days without mitogens contained significant amounts of both immunoglobulin A (IgA) and IgM, but very small amounts of IgG. Neutralizing activity of cell-free supernatants of cultured colostral cells was evaluated as described above. Neutralizing activity against the toxin was identified in five samples of culture supernatants out of 60 colostral cell specimens. In all five cases, the aqueous phase of colostrum also had a neutralizing effect against C. difficile toxin. Neutralizing activity against the toxin found in five supernatants of cultured colostral cells was completely abolished only by anti-human IgA antibody as assessed by immune precipitation.

Cells, Cultured↗

Subxiphoid cross-sectional echocardiographic imaging of the "goose-neck" deformity in endocardial cushion defect.

The cross-sectional echocardiographic demonstration of the "goose-neck" deformity is described in four patients with endocardial cushion defect. The diagnosis was confirmed in each patient by left ventricular angiocardiogram. The subxiphoid approach of cross-sectional echocardiography in diastole allowed visualization of an elongated, narrowed, and somewhat horizontally inclined configuration of the left ventricular outflow tract, which appeared almost identical to that obtained by angiocardiography. In systole, the right border of the left ventricle was composed of the cleft anterior mitral leaflet, the left-sided line of which was convex toward the left ventricular cavity. The mitral valvular echoes were thickened, jagged and irregular, which seemed to correspond to the scalloped appearance of the right border of the left ventricular silhouette in a systolic phase of the left ventricular angiocardiogram. There were no obvious differences between the goose-neck configuration of complete-type endocardial cushion defect and that of ostium primum atrial septal defect.

Echocardiography↗

Suppression of pokeweed mitogen-induced differentiation of human B cells by in vitro levamisole-treated T lymphocytes.

The generation of immunoglobulin-producing cells from human peripheral blood lymphocytes in pokeweed mitogen-simulated cultures was significantly suppressed by levamisole. Greatest suppression was observed when cells were incubated with levamisole at a concentration of 10(-6) M for 20 min or more prior to culture. Such suppression occurred when untreated as well as levamisole-treated B cells were co-cultured only with levamisole-treated T cells. Adding of levamisole-treated T cells to a combination of untreated autologous B and T cells resulted in the suppression of B cell differentiation. The results suggest that levamisole treatment of lymphocytes exerts suppression on pokeweed mitogen-induced B cell differentiation through its effect on T cell regulatory properties.

Adult↗

Resistance of human bone marrow CFUC to high-dose methotrexate cytotoxicity.

We have studied the susceptibility of human bone marrow cells to the high-dose methotrexate (MTX) cytotoxicity by the in vitro cultures of the granulocyte precursor cells (CFUC) in a medium containing various concentrations of MTX. Cultures of cells were exposed to 10(-9) to 10(-2) M MTX for 2, 6, 24 h and 10 days. About 50% of CFUC were killed by a 10-day exposure to 10(-7) M MTX or more. However, there was no loss of CFUC even at a drug concentration of 10(-3) M MTX if the exposure time was kept for 24 h or less. Within a 2 h exposure time, CFUC was resistant to MTX at the concentration of 10(-2) M. Such a strong resistance of bone marrow cells to MTX may warrant clinical usefulness of the high-dose and short-time MTX therapy with leucovorin rescue, which has widely been used in the treatment of various malignant diseases.

Bone Marrow↗

Lysosomal acid hydrolases in lymphocytes of I-cell disease.

Several lysosomal acid hydrolases were assayed in peripheral blood leukocytes from a patient with I-cell disease by the method of Hindman, J. and Cotlier, E. ((1972) Clin. Chem. 18, 971--975). The activities of lysosomal hydrolases in polymorphonuclear cells showed no significant differences between the patient, the parents, and normal controls, while lymphocytes from the patient exhibited the reduced activities of alpha- and beta-galactosidases, beta-glucuronidase, and N-acetyl-beta-glucosaminidase. After phytohemagglutinin-stimulated culture, lymphocytes from the patient showed a more definite reduction in the activities of these lysosomal enzymes; the activities of beta-glucuronidase, alpha-mannosidase, and N-acetyl-beta-glucosaminidase were reduced to about 20--30% of the activity in the phytohemagglutinin-stimulated control cultures, and the activities of alpha- and beta-galactosidases to 10% or less. Lymphocytes from the parents showed no significant difference in the activities of these enzymes from the controls, whether stimulated or not.

Adolescent↗

Mucocutaneous lymph node syndrome. A cross-sectional echocardiographic diagnosis of coronary aneurysms.

The cross-sectional echocardiographic technique for detecting coronary artery aneurysms of mucocutaneous lymph node syndrome (MLNS) was examined. When cutting the aortic root in round slices by the echocardiographic scanner, each of the right and left coronary arteries was imaged as a linear echo-free structure arising from the aortic root. Of 22 normal subjects, the left main coronary artery was imaged in all, the anterior descending branch in 18, the circumflex branch in six, and the right coronary artery in 18. Of 41 patients with MLNS, coronary artery aneurysms were detected as large echo-free spaces in four patients who were proved later to have these lesions by coronary angiography or autopsy. In addition, in four patients, whose echocardiograms demonstrated the coronary arteries to be normal, the angiographic studies showed that the coronary arteries were intact. These results suggest that the cross-sectional echocardiographic technique is a useful noninvasive diagnostic method for imaging the coronary arteries and the aneurysms in MLNS.

Aneurysm↗

Metabolic acidosis in patients receiving anticonvulsants.

Blood pH, bicarbonate, PCO2, serum calcium, alkaline phosphatase and red cell carbonic anhydrase were measured in 37 selected patients receiving anticonvulsants. Patients with metabolic acidosis showed a high incidence of hypocalcemia with increased alkaline phosphatase and a significant reduction of carbonic anhydrase-B activity. High iPTH levels were found in 13 patients, but this was not correlated with acid-base balance status. Anticonvulsant drugs seemed to inactive carbonic anhydrase-B activity. Metabolic acidosis might be one of the factors causing a disturbance of calcium metabolism in these patients.

Acidosis↗

Induction of suppressor activity on B-cell differentiation in human T-cell subset without fc(IgG) receptors by levamisole administration.

A single oral dose of 150 mg levamisole was administered to five healthy adults. Circulating Fc(IgG) receptor-bearing T cells (T gamma cells) increased for 5 days after levamisole intake, but total E rosette-forming cells showed no significant alterations. The generation of immunoglobulin-producing cells in the peripheral blood lymphocytes (PBL), which was induced in the in vitro pokeweed mitogen (PWM)-stimulated cultures, was significantly suppressed for 5 days after levamisole administration. Suppressor T-cell activity on B-cell differentiation, which was induced by levamisole intake, was evaluated by co-culturing with allogeneic untreated adult PBL in the PWM system in six other volunteers. A seemingly dose-dependent suppression on B-cell differentiation was exerted by T cells isolated on day 3 of levamisole treatment, but not by T cells differentiation was exerted by T cells isolated on day 3 of levamisole treatment, but not by T cells which were isolated before or on day 14 of the experiment. When T cells were fractionated into two subsets with regard to the presence or absence of Fc(IgG) receptors, suppressor T-cell activity appeared to be generated by levamisole largely in T cells lacking Fc(IgG) receptors, but not in T gamma cells.

Adult↗

Suppression of adult B cell differentiation in pokeweed mitogen-stimulated cultures by Fc(IgG) receptor-negative T cells from cord blood.

Unfractionated T lymphocytes from cord blood suppressed adult B cell differentiation into immunoglobulin-producing cells in pokeweed mitogen-stimulated co-culture system. Cord blood T cells were fractionated into T cells bearing Fc receptors for IgG (Tgamma cells) and T cells lacking Fc receptors for IgG(Tnon-gamma cells) by rosette formation with ox erythrocytes coated by the IgG fraction of rabbit antisera followed by Ficoll-Hypaque gradient sedimentation. T gamma cells from cord blood, even though isolated after the interaction with immune complexes, showed no suppressor activity on adult B cell differentiation, whereas Tnon-gamma cells exerted strong suppression to a similar extent to that by unfractionated cord T cells. The suppressor activity on B cell differentiation by Tnon-gamma cell as well as by unfractioned T cells from cord blood was completely abrogated by irradiation with 2000 rads. These results indicated that, contrary to suppressor function found in adult T cells, the suppressor activity in cord T cells might be exerted by a T cell subset lacking Fc receptors for IgG(Tnon-gamma cells).

Adult↗