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Biomedical subjects

N Taniguchi

Publications and source records attributed to N Taniguchi.

At least 649 records · Page 36Linked to original sources
PubMed1982

UDP-N-acetylgalactosamine:globoside alpha-3-N-acetylgalactosaminyltransferase. Purification, characterization, and some properties.

A UDP-N-acetylgalactosamine:globoside alpha-3-N-acetylgalactosaminyltransferase has been purified over 3500-fold in 4% yield from a Triton X-100 extract of canine spleen microsomes by affinity chromatography on globoside acid-agarose. Sodium dodecyl sulfate gel electrophoresis of the purified enzyme revealed two major bands with molecular weights of 66,000 and 56,000. Judging from the molecular weight of 120,000 estimated by Sephadex gel filtration in Triton X-100 and the above electrophoretic result, the enzyme presumably exists normally as a dimer. It required Mn2+ for its activity and had a pH optimum at 6.7-6.9. The enzyme catalyzes the transfer of N-acetylgalactosamine in alpha 1 leads to 3 linkage to globoside. Neither Fuc alpha 1 leads to 2Gal beta 1 leads to 4Glc nor H blood group substance nor deglycosylated mucin were acceptors. This indicates that the enzyme was distinct from both the N-acetylgalactosaminyltransferases converting the H to the A blood group substance and catalyzing synthesis of the Ser(Thr)-GalNAc linkage. Studies on substrate specificities indicate that the preferred substrates have the general structure GalNAc beta 1 leads to 3Gal-OR in which the nature of the R moiety has relatively little effect on activity. Kinetic analysis indicates UDP is a competitive inhibitor with respect to UDP-N-acetylgalactosamine and a noncompetitive inhibitor with respect to globoside. These studies demonstrate the first report of the properties of a purified enzyme catalyzing the transfer of sugar residues to glycolipids.

Animals↗
PubMed1982

Chromosome abnormalities involving 11p13 and low erythrocyte catalase activity.

Two unrelated patients with clinical features of 11p13 deletion syndrome, 3 years old and 3 months old, are reported. The clinical features of the patients included mental retardation, aniridia, nystagmus, blepharophimosis, and genitourinary abnormalities. Both patients were apparently free from Wilms' tumor and gonadoblastoma. Prometaphase banding analyses revealed a 46,XY,del(11)(p1300p1500) karyotype in one patient and 46,XX,dir ins(11;2)(p13;q12q23) in the other. Catalase activities in the erythrocytes in the two patients were respectively 65% and 56% of those of normal controls, close to the expected values in hemizygosity of the catalase gene. These findings confirmed a close linkage of the gene for catalase and those for the aniridia--Wilm's tumor or gonadoblastoma complex.

Catalase↗
PubMed1982

Comparative studies on nucleoside diphosphatase of rat ascites hepatoma and rat liver: activity level, purification and properties.

1. The activities of nucleoside diphosphatase in various rat ascites cells of hepatoma, and fetal and neonatal rat liver were much lower than that of normal adult rat liver. 2. The enzyme was purified from ascites hepatoma (AH-66 cell lines) to an apparently homogeneous state and the enzymatic properties were studied in comparison with the enzyme from rat liver microsomes. 3. The hepatoma enzyme had less stability based on the results of heat-inactivation experiments. 4. However, the other properties of hepatoma enzyme; Km value, molecular weight, optimal pH, isoelectric point, substrate specificity and antigenicity, were similar to those of rat liver enzyme.

Acid Anhydride Hydrolases↗
PubMed1982

Developmental changes of carbonic anhydrase activity of parotid gland and stomach of goat.

1. Carbonic anhydrase activities in the various tissues of ruminants and non-ruminants were compared. 2. The highest activity was found in the parotid gland of ruminants such as bovine and goat. However the activity in the kidney was not significantly different between the ruminants and non-ruminants. #. The effect of development on the carbonic anhydrase activity was studied. The activities in both the parotid gland and kidney of the goat were found to increase with age whereas the activities of the pancreas, liver and submaxillary gland did not change significantly. 4. The activities in the abomasum of the goat also increased with age however the other stomachs did not vary prominently.

Animals↗
PubMed1982

Induction of E-rosette-promoting factor in human plasma by levamisole: an assessment in a patient with partial DiGeorge syndrome.

A male infant with partial DiGeorge syndrome responded to weekly administration of levamisole (2.5 mg/kg of body weight) with an increase of circulating E-rosette-forming T cells. Thymic hormone activity in plasma appeared to be elevated to a near-normal level of 11.6 ng thymopoietin equivalent/ml after levamisole administration. The in vitro incubation studies indicated that levamisole by itself had no E-rosette-promoting ability, but a dialysable and relatively heat-stable plasma factor induced by levamisole both in the patient and in healthy individuals had E-rosette-promoting activity for the patient's lymphocytes. Such a plasma factor, however, could not be induced in all four thymectomized myasthenic subjects examined, suggesting a thymus-dependent nature of the plasma factor. These results suggest that levamisole might mediate an increased secretion of humoral factor(s) with E-rosette-promoting activity, even from such a rudimentary thymus as in the partial DiGeorge syndrome.

DiGeorge Syndrome↗
PubMed1982

Glutathione S-conjugate transport using inside-out vesicles from human erythrocytes.

Previous studies [Kondo, T., Dale, G. L. and Beutler, E. (1981) Biochim. Biophys. Acta, 645, 132-136] have shown evidence for the existence of two different active-transport processes for glutathione disulphide (GSSG) in human erythrocytes (the high-Km and low-Km processes). In the present investigation adenosine-triphosphate-dependent transport of glutathione S-conjugate was characterized in comparison with active glutathione transport using inside-out vesicles from human erythrocytes. Incubation of the vesicles with glutathione S-conjugate (S-2,4-dinitrophenylglutathione) was found to inhibit competitively the high-Km process of GSSG transport but not significantly affect the low-Km process. The glutathione S-conjugate transport required ATP. A lineweaver-Burk plot of the transport rate as a function of the conjugate concentration gave an apparent Km value of 0.94 mM. The Km value of ATP-Mg was 0.76 mM. The transport of glutathione S-conjugate was dependent on temperature. Preincubation of vesicles with dithiothreitol resulted in an increase of the transport rate while thiol reagents, such as iodoacetamide, N-ethylmaleimide and p-chloromercuribenzoate inhibited the transport. Addition of nucleotides, such as CTP, UTP or GTP had no effect on the transport. These findings suggest that glutathione S-conjugate formed by the catalytic reaction of glutathione S-transferase in erythrocytes under the exposure to electrophilic compounds, is eliminated via the same transport process for GSSG elevated under oxidative stress.

Biological Transport, Active↗
PubMed1982

Major depressive episode and low dose dexamethasone suppression test.

The authors studied the validity of a low dose (0.5 mg) dexamethasone suppression test (DST) in identifying depression. Nine patients who met the criteria of major depressive episode (MDE) in the Diagnostic and Statistical Manual of Mental Disorders, another nine psychiatric patients and one normal subject underwent the DST. At least one of the two blood samples obtained either at 8 a.m. or at 2 p.m. from each of the nine patients with MDE showed a cortisol concentration of over 5.0 micrograms/dl, while the cortisol concentration in the other 10 subjects was uniformly suppressed under this level. All the patients with MDE could be identified by nonsuppression of the cortisol secretion at 8 a.m. or at 2 p.m. An "early escape" phenomenon in depressed patients reported by Carroll et al. (1976) was absent in a 0.5 mg DST, and the blood samples at 8 p.m. were less useful for identifying the depressive patient. The reason why the one point sampling method used by previous investigators was insufficient to identify the depressed patient was discussed.

Adult↗
PubMed1982

Subcostal two-dimensional echocardiographic imaging of peripheral right coronary artery in Kawasaki disease.

A new two-dimensional echocardiographic technique was developed to detect peripheral right coronary aneurysms in Kawasaki disease. Because the main stem of the right coronary artery runs along the tricuspid valve ring and the posterior interventricular groove, these regions were examined for coronary aneurysms using the subcostal approach. Of 52 patients with Kawasaki disease, 14 right coronary aneurysms were visualized in eight patients. Most of the coronary aneurysms were elicited as circular or oval echo-free spaces on the right side of the right ventricle or at the area around the tricuspid valve ring. These echocardiographic features coincided well in size, shape and anatomic position with angiographic appearances. The subcostal approach could not image the normal coronary artery. In three patients whose echocardiograms showed no abnormal echo-free space, the angiographic studies proved that the right coronary arteries were intact. These results suggest that this echocardiographic technique is useful for detecting peripheral right coronary aneurysms in patients with Kawasaki disease.

Aneurysm↗
PubMed1982

Hereditary high concentration of glutathione in canine erythrocytes associated with high accumulation of glutamate, glutamine, and aspartate.

We have found a dog family in which there were five cases of increased red cell glutathione corresponding to four to five times the normal concentration without any clinical signs. In the present study, we mainly examined the concentrations of free amino acids in the erythrocytes, plasma, and urine of two of the dogs, and we demonstrated that the concentrations of glutamate, aspartate, and glutamine in their erythrocytes increases to 92, 63, and 13 times the mean value in the normal blood, respectively. There were no changes observed in the other amino acids as compared to normal, although the glycine and histidine in the erythrocyte showed slight increases. The concentrations of amino acids in the plasma and urine of the dogs were almost equal to normal ones. The activities of some of the enzymes involved in the glutathione metabolism in the erythrocytes from the two dogs were all within the normal range. The increased level of glutathione could be explained by the fact that the feedback inhibition of gamma-glutamyl cysteine synthetase by glutathione was released by the high levels of glutamate in the erythrocytes.

Amino Acids↗
PubMed1982

Impaired synthesis of intracellular heparan sulfate in skin fibroblasts of Lowe's syndrome.

Synthesis and distribution pattern of intracellular GAG were evaluated skin fibroblasts cultured from two patients with Lowe's syndrome and control children. After trypsinization and Pronase treatment of fibroblasts at around the tenth generation of passage and at the stage of culture confluence, GAG were isolated by precipitation with CPC in the presence of 0.25M NaCl and analyzed by cellulose acetate electrophoresis in 0.05M barium acetate buffer. Relative proportion of intracellular heparan sulfate was about 20% of total in Lowe's syndrome fibroblasts and 35% to 40% in control fibroblasts. Incorporation experiments with labeled precursors showed that [35S]sulfate incorporation into intracellular heparan sulfate of Lowe's syndrome was about half that of controls. There were no significant differences in [38S]sulfate uptake into dermatan sulfate and chondroitin sulfate isomers between Lowe's syndrome and control fibroblasts. The results of incorporation experiment with [14C]glucosamine were essentially the same as with [35S]sulfate. There was no apparent tendency for undersulfation in intracellular sulfated GAG of Lowe's syndrome fibroblasts. These results suggested that impaired synthesis, rather than defective sulfation, of intracellular heparan sulfate might characterize one of the metabolic aberrations in Lowe's syndrome fibroblasts.

Cells, Cultured↗