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Biomedical subjects

S Muramoto

Publications and source records attributed to S Muramoto.

At least 37 records · Page 2Linked to original sources
PubMed1990

The critical levels and the maximum metal uptake for wheat and rice plants when applying metal oxides to soil.

Wheat is more sensitive to CdO and ZnO compared with rice plant. The yield of wheat decreased by 30% in the presence of 30 ppm Cd, but that of rice plants by only 8%. The critical levels of meal uptake by wheat and rice plants for applying metal oxides to soil (CdO, ZnO, PbO) were determined. The highest concentration obtained for wheat grain was 141 micrograms/g Cd at the Cd 10,000 ppm in soil. This value is higher than the value of 4.97 micrograms/g for unpolished rice and higher than any other we have seen in the reports for treatment with CdO. Also, concentration of more than 1.0 micrograms/g Cd in wheat was observed at 5 pm Cd, while similar concentrations for rice plants were observed at 30 ppm Cd in soil.

Cadmium↗
PubMed1989

Unresponsiveness to L-DOPA in parkinsonian patients: a study of homovanillic acid concentration in the cerebrospinal fluid.

In this study, concentrations of homovanillic acid (HVA), a principal metabolite of dopamine (DA), in the cerebrospinal fluid (CSF) were measured in 17 patients with Parkinson's disease (PD) who had been effectively treated with L-DOPA and in 8 patients clinically diagnosed as having striatonigral degeneration (SND) and for whom treatment with L-DOPA had proved ineffective. L-DOPA administration, consisting of a daily dosage of 600 mg plus 150 mg aromatic L-amino acid decarboxylase inhibitor was continued in all cases for at least 3 months. In the PD group, the HVA value was 511.6 +/- 196.5 pmol/ml and in the SND group, 144.9 +/- 83.4 pmol/ml. This remarkably low value for the SND group suggests that there may exist severe disorders in the uptake and decarboxylation of exogenous L-DOPA.

Aged↗
PubMed1989

Heavy metal tolerance of rice plants (Oryza sativa L.) to some metal oxides at the critical levels.

The toxicity of metal oxides (CdO, ZnO, PbO) were compared with each other and the critical levels of metal uptake by rice plants were determined. The order of metal toxicity to rice plants is CdO greater than ZnO greater than PbO. The highest concentration obtained for unpolished rice was 4.97 micrograms/g at the Cd 10,000 ppm in soil. This values is higher than every other we have seen in the reports for treatment with CdO. We are able to find out that the concentration of 10,000 ppm Cd in the form of CdO in the critical one towards rice plant. By contrast, such damage was not observed at even higher levels of ZnO and PbO were considered to have low toxicity toward rice plant. Also, a negative correlation between Zn or Cu accumulation in rice plants and Cd concentration in soil was found.

Cadmium↗
PubMed1983

Effect of feeding cholesterol and sitosterol on hepatic steroid 12 alpha-hydroxylase activity in female hamsters.

The effects of dietary cholesterol and sitosterol on the activity of the hepatic steroid 12 alpha-hydroxylase, gallbladder bile acid composition, and serum and liver cholesterol concentrations were studied in female hamsters. The 12 alpha-hydroxylase activity was inhibited by 63% in cholesterol-fed animals and by 30% in sitosterol-fed animals. Cholesterol feeding increased percentages of chenodeoxycholic and lithocholic acids in gallbladder bile with reciprocal decrease of cholic acid, while sitosterol feeding had no significant effect on bile acid composition. Cholesterol feeding increased levels of serum and liver cholesterol, on the contrary, sitosterol decreased both concentrations. A positive correlation between the 12 alpha-hydroxylase activity and the ratio of cholic acid plus its metabolites to chenodeoxycholic acid plus its metabolite was also observed. These results support the proposal that steroid 12 alpha-hydroxylase is a major factor in determining the relative proportion of cholic acid and chenodeoxycholic acid synthesized in the liver and indicate that cholesterol feeding increased percentage of chenodeoxycholic acid by inhibiting the activity of steroid 12 alpha-hydroxylase.

Animals↗
PubMed1983

Sex differences in gallbladder bile acid composition and hepatic steroid 12 alpha-hydroxylase activity in hamsters.

The gallbladder bile acid composition and the activity of the hepatic steroid 12 alpha-hydroxylase were determined in male and female hamsters. Cholic acid, chenodeoxycholic acid, and deoxycholic acid were the major bile acids in both sexes; in addition, 7-ketodeoxycholic acid and lithocholic acid were present. A sex-linked difference in the ratio of cholic acid (plus its metabolites) to chenodeoxycholic acid (plus its metabolite) was observed. The ratio was 1.93 +/- 0.39 in males and 2.74 +/- 0.54 in females. Another sex-linked difference was found in the activity of the 12 alpha-hydroxylase. The extent of the 12 alpha-hydroxylation of 7 alpha-hydroxycholest-4-en-3-one to yield 7 alpha, 12 alpha-dihydroxycholest-4-en-3-one was about two times greater in the microsomal suspension obtained from the liver of female hamsters than in that of male hamsters. A positive correlation between the 12 alpha-hydroxylase activity and the ratio of cholic acid/chenodeoxycholic acid was also observed. These results strongly support the proposal that the activity of the 12 alpha-hydroxylase is the major factor in determining the relative proportion of cholic acid and chenodeoxycholic acid formed from cholesterol in the liver.

Animals↗
PubMed1981

[Clinical evaluation of cardiac function test using scintiview (author's transl)].

Cardiac function was studied with Scintiview in 107 cases, 24 normal and 83 affected cases, and the following results were obtained. 1. Better data were obtained with converging collimeter than with parallel collimeter in cardiac study. (2) Red blood cells were sufficiently labeled with 99mTc using stannous chloride as reductant, and it was proven to be applicable to measurement of circulation blood volume. (3) Pulmonary circulation time and the systemic circulation time calculated from time activity curve, greater than 9.0 seconds and greater than 25 seconds, respectively, were considered abnormal prolongation. (4) Cardiac output index (cardiac output/circulation blood volume), less than 1.10 was considered decreased cardiac output. (5) Stroke volume index ((stroke volume/circulation blood volume)x 100, less than 1.70 was considered decreased stroke volume. (6) Ejection fraction, less than 60% was considered decreased left ventricular wall motion. (7) Cardiac function index (cardiac output index X ejection fraction), less than 80 was considered decreased cardiac performance.

Adolescent↗