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Biomedical subjects

K Tatara

Publications and source records attributed to K Tatara.

At least 127 records · Page 7Linked to original sources
PubMed1986

Altered kinetic properties of a mutant adenine phosphoribosyltransferase.

Three siblings in a Japanese family experienced recurrent 2,8-dihydroxyadenine urolithiasis despite the presence of adenine phosphoribosyltransferase (APRT) activities in the hemolysates (19.9% to 28.2% of normal value). However, studies on viable T cells from these patients indicated that APRT was not functional in viable cells. Further analysis of the partially purified enzymes from hemolysates disclosed that patient's APRT had a reduced affinity to 5-phosphoribosyl-1-pyrophosphate (PRPP). Seven healthy members of this family whose APRT functioned normally in viable T cells had the erythrocyte enzyme levels between the patients and normal individuals (38.2% to 65.6%), suggesting that they are carriers of the defective gene. These results indicate that the defective gene code a unique mutant APRT with a reduced affinity to PRPP, and the patients are homozygotes. The mutant enzyme was also shown to be more heat-stable than normal enzyme. However, since mutant enzyme, unlike normal enzyme, was insensitive to the stabilization effect of PRPP, the latter became more heat-stable than the former when the heat treatment was performed in the presence of PRPP. This type of defect with alterations in the kinetic and physical properties of APRT as described here is likely to be a common type of APRT deficiency in Japan.

Adenine Phosphoribosyltransferase↗
PubMed1986

Myocarditis with myocardial infarction like findings in a 3-year old girl.

A 3 year-old Japanese girl had an acute onset associated with vomiting. The electrocardiogram (ECG) indicated changes similar to those of acute myocardial infarction (MI); there was no past history of kawasaki disease. Selective coronary angiography taken on the 28th day of illness revealed no abnormality. Thallium 201 scintigraphy was also performed and it revealed that the area of absent myocardial uptake was in the anterior wall. In serological findings, antibody titers against Coxsackie B-3 virus had risen significantly; therefore acute myocarditis caused by Coxsackie B-3 virus infection was diagnosed.

Antibodies, Viral↗
PubMed1985

Severe impairment in adenine metabolism with a partial deficiency of adenine phosphoribosyltransferase.

Among three unrelated patients with recurrent 2,8-dihydroxyadenine urolithiasis, two completely lacked adenine phosphoribosyltransferase (APRT) in both erythrocytes and proliferative T cells. The third patient possessed significant enzyme activities in both hemolysates and T-cell extracts at levels comparable to heterozygotes for complete APRT deficiency. Despite significant APRT activities in cell extracts, cultured T cells from the third patient were at least 100-fold more resistant than normal T cells to an adenine analog, 6-methylpurine, whose cytotoxicity is dependent on APRT. These data indicate that APRT activity in T cells from the third patient is positive in cell extracts, but apparently not operating in viable cells. Although the cells from the patients with complete APRT deficiency were as resistant to 6-methylpurine as the cells from the third patient, the cells from the heterozygotes for complete APRT deficiency were almost as sensitive as normal T cells. Therefore, adenine metabolism in the third patient but not in the heterozygotes seems to be as severely impaired as in the patients with complete APRT deficiency, which is quite consistent with the clinical manifestations in these individuals.

Adenine↗
PubMed1984

Age specific mortality trends in the U.S.A. from 1960 to 1980: divergent age-sex-color patterns.

Trends in age-specific mortality (10-year age groups, 5-74) for the U.S. population were reviewed for all causes of death from 1960 to 1980. The age-specific mortality rate generally declined. However, the following age-sex-color groups showed divergent mortality trends compared to those of other groups: (1) The death rates for white male teenagers and young adults (ages 15-24 and 25-34) increased during 1960s and stayed at the same level during 1970s. The ratio of male to female deaths for white teenagers and young adults (15-24 and 25-34) increased over both decades, although the mortality rate for white women age 15-24 increased during the 1960s. (2) Non-white men age 15-24 and 25-34 experienced biphasic mortality trends, with a rise peaking in 1971 and then a fall. (3) The mortality ratios, non-white to white men, age 25-34 and 35-44, were far higher then those of other age groups. (4) The mortality ratios, non-white males to females, increased steadily for all age groups, and those of age groups 15-24 and 25-34 turned up sharply. Selected causes of death (1960-1977) were reviewed to uncover reasons for the unfavorable mortality trends among males. The following causes contributed to rising mortality among males: (a) accidents, suicide, and homicide for white and non-white teenagers and young adults, age 15-24, 25-34 and 35-44; (b) suicide and homicide for non-white men age 45-54; (c) cirrhosis of the liver for white men age 35-44 and for non-white 25-34, 35-44 and 45-54; (d) malignant neoplasms for white men age 35-44 and for non-white age 45-54.

Accidents↗
PubMed1984

Alcohol consumption, blood pressure and stroke mortality in Japan.

The relationship between the national blood pressure level of an over 10,000 member representative sample of the population and alcohol consumption, using the time-series data during the period 1956-1980 was analysed. Analysis by multiple regression analysis showed alcohol consumption to be significantly related to the mean systolic blood pressure level for men independent of the treatment rate of hypertension, obesity, salt consumption and smoking rate. The relationship between alcohol consumption and stroke mortality using the age-adjusted stroke mortality for the middle-aged and alcohol consumption by prefecture (an administrative district of a province in Japan), in 1975 was also investigated. Stroke mortality for middle-aged men was highly significantly related, that for women was borderline but still significantly related, and the male:female ratio of the age-adjusted stroke mortality was also highly significantly related to alcohol intake. Thus, alcohol intake may play a role in increasing blood pressure levels and precipitate stroke, although it is possible that other confounding factors related to alcohol drinking may be related to blood pressure and also to stroke mortality.

Adult↗
PubMed1982

Immunoreactive somatostatin in catecholamine-producing extra-adrenal paraganglioma.

A patient with catecholamine-producing extra-adrenal paraganglioma was found to have a high concentration of immunoreactive somatostatin (IR-SRIF) in the peripheral blood plasma (47.0 pg/ml, normal; 13.3 +/- 5.3 pg/ml, mean +/- SD). After removal of the tumor, the plasma SRIF level fell within normal range (8.7 pg/ml). In the resected tumor, a considerable amount of IR-SRIF (71.0 ng/g wet weight)( was also detected and SRIF-positive tumor cells were demonstrated by the immunoperoxidase technique. Chromatographic analysis of an extract of the tumor showed the presence of two IR-SRIF components of large molecular size besides a component consistent with authentic tetradecapeptide SRIF (SRIF 14), and one of these had the same molecular size as octacosapeptide SRIF (SRIF 28). This seems to be the first report of a catecholamine-producing extra-adrenal paraganglioma that produces IR-SRIF with molecular heterogeneity.

Adrenal Gland Neoplasms↗