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Biomedical subjects

T Ohtsuki

Publications and source records attributed to T Ohtsuki.

227 records · Page 13Linked to original sources
PubMed1981

Increase in simple reaction time of knee extension induced by simultaneous bilateral performance.

Simple reaction time to an auditory stimulus was measured for separate unilateral and simultaneous bilateral knee-extension tasks. The latencies of the electromyographic discharge (155.3 msec.) and knee-joint movement (231.0 msec.) were longer in the bilateral condition than in the unilateral condition (139.2 and 218.8 msec., respectively), while the time difference between EMG onset and knee-movement onset was the same for the unilateral (79.5 msec.) and bilateral (76.2 msec.) conditions. Interhemispheric inhibition was discussed as the mechanism for this unilateral-bilateral difference.

Adult↗
PubMed1980

Dynamic properties of concentrated suspensions of charged polystyrene spheres.

Ordered structure formation of charged polystyrene spheres was studied by measuring the order-disorder phase diagrams as well as the mechanical properties. The phase diagrams indicate that the ordering of polystyrene spheres obeys Lindemann's law of crystal melting, in which the Lindemann's parameter is about 5%. The rigidity of about 10(3) dyn/cm(2) was observed in the ordered suspension of polystyrene spheres as measured by a torsional quartz crystal method. The steady flow properties of suspensions of polystyrene spheres showed a remarkable change from a Bingham body to a Newtonian liquid at the transition point. The limit of elasticity in the ordered phase was about 1 dyn/cm(2). The viscosity in the disordered phase was well explained by the free volume theory of liquids. It is concluded from these facts that the ordered phase of polystyrene spheres is a real "crystal" whereas the disordered phase is a "liquid". Properties of ordered structures in biological systems are also discussed.

Journal Article↗
PubMed1976

Genetic basis of individual differences in tissue composition.

A total of 19 pairs of twin adolescent boys, 14 MZ and 5 DZ, were used to determine the relative contribution of the genotype to the individual differences observed in surface density of muscle, subcutaneous fat, and bone. The cross-sectional areas of these tissue components were calculated from photographs of the upper arm, taken by means of an ultrasonic apparatus. The respective mean percentage intrapair difference in MZ and DZ twins was 6.9 and 9.8 for total area, 6.6 and 7.8 for muscle, 13.9 and 32.0 for fat, and 6.7 and 31.3 for bone tissue. Interindividual variations in bone only could be ascribed to genetic differences.

Adipose Tissue↗
PubMedDate not supplied

Prognosis of primary hepatocellular carcinoma.

Prognosis of 600 consecutive patients with hepatocellular carcinoma was analyzed in relation to treatment. They were divided into three stages based on four parameters of advanced disease: ascites, tumor greater than 50% of the two-dimensional size of the liver, serum albumin below 3 gm per dl, and serum bilirubin above 3 mg per dl. Stage I had none of these signs; Stage II one or two signs, and Stage III three or all signs. Of 600 patients, 98 had resection, 333 had nonsurgical treatment (158 treated by intraarterial chemotherapy, 94 systemic chemotherapy, 77 transcatheter embolization, and 4 others) and 169 no treatment. The median survival of untreated patients was only 1.6 months from diagnosis, and no untreated Stage III patient lived more than 3 months; there was a median survival of 0.7 month. Surgically treated patients lived significantly longer than nonsurgical patients of comparable stages; median survival was 19.6 months in the former and 2.8 months in the latter. Whereas Stage I patients did fairly well without treatment, chemotherapy significantly prolonged survival of patients of Stages II and III. These results suggest that early diagnosis and hepatic resection improve prognosis in patients with hepatocellular carcinoma in the areas where this cancer frequently emerges unicentrically. In view of the generally poor prognosis, liver transplantation is recommended when resection is not possible or indicated, and before extrahepatic metastasis occurs.

Adolescent↗
PubMedDate not supplied

Interleukin 18 enhances Fas ligand expression and induces apoptosis in Fas-expressing human myelomonocytic KG-1 cells.

Interleukin-18 (IL-18) induces apoptosis in human myelomonocytic KG-1 cells as determined by agarose gel electrophoresis, and flow cytometry after propidium iodide (PI) staining. Apoptosis was detected 20 hours from the start of culture at concentrations of 100 ng/ml of the cytokine. Although IL-18 induces the production of large amounts of interferon gamma (IFN-gamma) by KG-1 cells, conditioned media could not induce apoptosis of fresh cells. The protein expressions of p53 and Fas ligand by KG-1 cells, which constitutively express the Fas antigen (CD95), were found to increase after exposure to IL-18 for 20 hours. Both Fas ligand and its receptor were found to be functional by in vitro assays on Fas-expressing target cells and an agonist anti-Fas antibody, respectively. In conclusion, IL-18 enhances the expression of Fas ligand by Fas-expressing KG-1 cells and induces apoptosis in the cells through a mechanism probably involving the Fas pathway.

Apoptosis↗