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Biomedical subjects

Y Nishida

Publications and source records attributed to Y Nishida.

At least 469 records · Page 26Linked to original sources

Inhibition of purine nucleoside phosphorylase activity and of T-cell function with allopurinol-riboside.

Allopurinol-riboside competitively inhibits the action of purine nucleoside phosphorylase on inosine in vitro with a Ki of 277 mumol. After simple incubation of allopurinol-riboside with PNP, allopurinol was not formed. Lymphocyte blastogensis induced by PHA and Con A was significantly suppressed by allopurinol-riboside in a concentration-dependent manner. When LPS was used as a mitogen, the inhibition of allopurinol-riboside on lymphocyte proliferation was less marked. Humoral immunity was not suppressed by allopurinol-riboside. In contrast, cellular immunity was significantly suppressed by allopurinol-riboside in vivo. These results suggested that allopurinol-riboside is a drug which produces a model of PNP deficiency, and that it may be a useful inhibitor of cellular immunity.

Allopurinol↗

Are epinephrine and gastrin accelerative factors of acute cinchophen ulcer?: Studies on gastric mucosal microcirculation and gastric secretion.

Measurements of serum epinephrine and gastrin, simultaneously, gastric mucosal blood flow and gastric secretion were carried out in cinchophen treated dogs. No significant changes in either serum concentrations of epinephrine and gastrin or fundic mucosal microcirculation after a single 100 mg/kg cinchophen administration were found while gastric secretion increased markedly after the medication. On the other hand, a significant increase in serum epinephrine and gastrin levels was observed while gastric secretion decreased significantly after large doses of cinchophen (300 mg/kg) were injected intravenously. Here gastric mucosal microcirculation is decreased. Repeated administration of 100 mg/kg cinchophen for 3 to 7 days brought about an increase in epinephrine and gastrin levels and caused an occurrence of fundic mucosal hemorrhage. Sympathetic discharge and gastrin release were not seen after a 3-week period of cinchophen administration. Cinchophen ulcers were produced, even when contact between the bile and the stomach mucosa was avoided. Vagotomy had no connection with ulceration and gastric secretion.

Animals↗

Tocopherol level in human blood cells.

The study was undertaken on alpha-tocopherol levels, separated from other analogs, in the red blood cells (RBC) of cord blood, premature infants, healthy children and adults as well as in pregnant women, and compared with the plasma levels. 1. The majority of tocopherol found in the RBC was localized in the membranes. 2. Only alpha-tocopherol was found in the RBC, while alpha- and gamma-tocopherol were found in the plasma. 3. Alpha-tocopherol level in the RBC changes during development in parallel with that in the plasma. However, changes in the level in RBC were smaller than those of the plasma. 4. The ratio of alpha-tocopherol level in the RBC to the plasma was higher in the cord blood and premature infants than in the children and adults. 5. With regard to the cases with high plasma tocopherol levels, a different finding was obtained on the RBC level between pregnant women and adults with a large amount of tocopherol. In the latter, high RBC levels were observed as the plasma levels were elevated, while in spite of a high plasma tocopherol level, the lowest RBC levels were found in the pregnant women.

Adolescent↗

An explanation for the high incidence of congenital rubella syndrome in Ryukyu.

An exceptionally high incidence of congenital rubella syndrome (CRS) has been noted in Ryukan children who were infants in utero during an extensive rubella epidemic in the Ryukyu Islands in 1964 through the spring of 1965. In 1965, the Congenital Rubella Study Group of Kyushu University registered in the Ryukyus 408 cases of CRS and an incidence of 20 cases of CRS per 1000 births. The nearby Amami Islands, on the other hand, had a low incidence of CRS. Seroepidemiologic studies indicated a high prevalence of antibodies in the Ryukyus but a low prevalence in the Amamis. Since CRS is uncommon throughout Japan, some investigators have hypothesized that Japanese strains of the virus are avirulent and that a virulent American strain caused the epidemic in the Ryukyus. However, retrospective seroepidemiologic studies reported here indicate that the high incidence of CRS in the Ryukyus was more probably due to low seropositivity and a resultant high attack rate of rubella among pregnant women, rather than to a hypothetical virulent teratogenic strain of rubella virus. Conversely, the data suggest that the low incidence of CRS in Japan may reflect the infrequency of rubella nonimmunes in women of childbearing age.

Antibodies, Viral↗

Studies on the factors influencing the hydrogen peroxide hemolysis test.

There seems to be a greater variation between laboratories in hydrogen peroxide hemolysis techniques than in other clinical laboratory procedures. In this report, factors influencing hemolytic values were examined and the effect of the combination of these factors on the results was analysed statistically by using the orthogonal array. Factors influencing hemolysis induced by hydrogen peroxide were as follows; the concentration of hydrogen peroxide, temperature in the peroxide reagent when added to the red cell suspension, the red cell concentration in the cell suspension and the addition of charcoal to the reaction mixture. However, addition of charcoal may not be essential to stabilize the hemolytic values and other factors such as keeping blood for 4 hours at room temperature before testing, the difference between investigators, a reaction time 2 or 3 hours and the technique of adding peroxide reagent to the cell suspension, had little effect on hemolysis. The most important factor was the temperature in hydrogen peroxide solution. The estimated hemolytic values by the orthogonal array linearly correlated with the plasma tocopherol levels.

Hemoglobins↗

Abnormal serum immunoglobulin levels in Down's syndrome patients.

Serum immunoglobulin levels were measured in 20 patients with Down's syndrome and 16 mentally retarded cerebral palsy control patients. Significant elevation of IgG and IgD levels were found in the Down's syndrome as compared with the control patients. Serum IgD level in Down's syndrome individuals significantly decreased with increasing age. Serum IgA level was significantly elevated in older Down's syndrome patients but showed no change in younger Down's syndrome patients. Serum IgM and IgE levels were slightly elevated in Down's syndrome patients, but these differences were not significant. The elevated immunoglobulin levels in Down's syndrome individuals seem to be a response to increased frequency of infection.

Adolescent↗

Hyperlipidaemia in patients with Down's syndrome.

Plasma lipid levels were measured in 20 mongoloid and 16 non-mongoloid mentally retarded subjects. Significant elevations of plasma triglyceride levels were found in patients with Down's syndrome compared with mentally retarded controls. However, no significant difference was found in plasma cholesterol, phospholipid and free fatty acid levels between the mongoloids and control subjects.

Adolescent↗

Tubular function impairment in patients with asymptomatic hyperuricemia.

Renal function studies were done on asymptomatic hyperuricemic subjects and normouricemic controls matched as to age, sex and blood pressure. Abnormal urinary sediments and proteinuria were found more frequently in asymptomatic hyperuricemic subjects than in the controls. In addition, the maximal osmolar concentrating ability of urine was markedly reduced in the asymptomatic hyperuricemic subjects. There was no difference in renal function measured by phenolsulfonphthalein excretion between the groups. Our results suggest that hyperuricemia alone may contribute to renal tubular impairment.

Adult↗

Synthesis and concentration of 5-phosphoribosyl-1-pyrophosphate in erythrocytes from patients with Down's syndrome.

Plasma urate levels and erythrocyte glucose-6-phosphate dehydrogenase activity were not significantly different in patients with Down's syndrome when compared with control subjects with mental retardation. No significant difference was found in 5-phosphoribosyl-1-pyrophosphate (PRPP) concentration and synthesis of PRPP in erythrocytes from glucose between subjects with Down's syndrome and controls. The purine metabolism of Down's syndrome is discussed.

Adolescent↗

Concentrations of adenine nucleotides in erythrocytes of patients with gout.

Gout has long been known as a disease of the high social class or of those with achieved social status. Brooks and Mueller (1966) studied the relationships between behavior and serum uric acid levels among university professors. They indicated that personal characteristics of drive, achievement, and leadership are positively associated with the uric acid levels in plasma. Hansen and Dimitrakondi (1974) reported a marked decrease in ATP levels in psychotic depression and significant correlation between ATP concentration and mood scores. We estimated the adenine nucleotides in erythrocytes of gouty patients.

Adenine Nucleotides↗