Biomedical subjects
Publications and source records attributed to T Nishinaka.
Rat lens contains two classes of glutathione S-transferase (GST) isozymes; one is class mu, Yb1-Yb1, and the other is class pi, Yp-Yp, judged from their molecular weights, immunological properties and N-terminal amino acid sequences. The expression pattern of GST isozymes in the rat lens is different from that in pig and bovine lenses which have only class pi and class mu isozymes, respectively.
Class Pi glutathione S-transferase was purified to homogeneity from pig lens cytosol. This enzyme was composed of two identical 22 kDa subunits and had isoelectric point of 8.5 from the results of SDS gel electrophoresis, gel filtration, amino acid sequence analysis and isoelectric focusing. Amino acid sequence of N-terminal 15 residues was almost identical to class Pi enzymes from human, rat and mouse. Antibody against the pig enzyme crossreacted to human glutathione S-transferase-pi and anti-rat glutathione S-transferase-P antibody crossreacted to pig enzyme.
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Hepatic estradiol-17 beta dehydrogenase from chickens catalyzed the reduction of the 3-keto group of androgens such as 5 alpha-dihydrotestosterone and 5 alpha-androstane-3,17-dione as well as the 17-keto reduction of 4-androstene-3,17-dione and dehydroepiandrosterone. The reaction products from 17-ketosteroid and 3-ketosteroid substrates were identified as 17 beta-hydroxysteroids and 3 beta-hydroxysteroids, respectively, by thin layer chromatography, high performance liquid chromatography and gas chromatography. Barbital inhibited both 17 beta-estradiol dehydrogenase and 5 alpha-androstane-3,17-dione reductase activity noncompetitively giving the same kinetic constant, Ki = 50 microM. 5 alpha-Androstane-3,17-dione competitively inhibited 17 beta-estradiol dehydrogenase activity. These results indicate that chicken liver estradiol-17 beta dehydrogenase is in fact a 3 beta- and 17 beta-hydroxysteroid dehydrogenase and that both 3- and 17-ketosteroids bind to the same catalytic site.
The patient was a 64-year-old woman who showed muscle weakness and tremor of upper extremities and gait disturbance at the age of 62 years. The symptoms progressed and she was admitted to our hospital. Neurological examination revealed muscle weakness, muscle atrophy and fasciculation bilaterally in the upper extremities. The deep tendon reflexes were reduced in the upper extremities and increased in the lower extremities, but Babinski's sign was not present. There was mild hand tremor at rest (right greater than left). Muscle rigidity was also evident. Her gait was small-stepped and her trunk was bent forward. She showed hypomimia, but no dementia was detected. She died of respiratory failure 7 months after admission. The duration of the illness was about 2 years. At autopsy, macroscopic examination showed depigmentation of the substantia nigra and locus ceruleus, and atrophy of the anterior roots of the spinal cord. Microscopic examination revealed a few senile plaques in the temporal cortex. In the substantia nigra, the number of melanin-containing cells was decreased in its central parts. A few Lewy bodies were found in some of the remaining neurons, and melanin pigment migrated into the parenchyma. In the locus ceruleus and dorsal motor nucleus of vagus, abundant Lewy bodies and mild astrocytosis were seen. A few Lewy bodies were also seen in the nucleus raphe, nucleus basalis of Meynert and hypothalamic nuclei. Severe neuronal loss of the anterior horn cells was observed in the cervical segment, and to a lesser degree, in the lumbo-sacral segments. segments.(ABSTRACT TRUNCATED AT 250 WORDS)
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We investigated the mechanical properties of the descending aortic wall relative to its structural change caused by reduced pulse pressure in long-term nonpulsatile left heart bypass (LHB). Fifteen adult goats (53-68 kg) were divided into three groups: five goats underwent LHB with a nonpulsatile pump for 31 to 381 days (Group N), five goats underwent LHB with a pulsatile pump for 24 to 130 days (Group P), and the other five goats were used as normal control animals (Group C). The aortic pulse wave pressure was 17+/-7 mm Hg in Group N, 43+/-1 mm Hg in Group P, and 39+/-2 mm Hg in Group C. Structural changes were evaluated using wall thickness and the volume ratio of elastin and collagen. The mechanical properties were evaluated using "beta," which was calculated according to the equation: = (In P/Ps)/(Do/Ds-1), where Ps was the standard pressure, Ds was the wall diameter at pressure Ps, and Do was the wall diameter at pressure P. The wall thickness of the aortic wall in Group N (1.6+/-0.3 mm) was significantly thinner than that in either Group P (2.2+/-0.3 mm) or Group C (2.1+/-0.2 mm). The volume ratio of elastin in Group N (51 +/- 3%) was higher than that in Group P (44+/-1%) or Group C (40+/-1%), whereas no significant difference was found in the volume ratio of collagen between those in Group N (10+/-1%), Group P (9+/-2%), and Group C (10+/-1%). The stiffness parameter, beta, in Group N (3.1+/-0.7) was slightly higher than that seen in Group P (2.9+/-0.4) or Group C (2.9+/-0.2), but there was no significant difference between the three groups. These results indicate that long-term nonpulsatile LHB caused marked structural changes in the aortic wall, whereas the change in mechanical properties were not significant with regard to stiffness.
We investigated endocrine circadian rhythm (CR) during pulsatile and nonpulsatile left heart bypass (PLHB and NLHB). A ventricular assist device (VAD) was installed in five goats. After 2 weeks of PLHB, NLHB was subsequently conducted for 4 weeks. The levels of melatonin, cortisol, and renin activity were measured every 2 hours for 24 hours on the last day of the second PLHB week and the second and fourth NLHB weeks. Acquired data were compared with those of the normal control goats (Cont) to determine the presence or absence of CR, as well as the timing, acrophase, amplitude, and mesor of CR. Variations in melatonin, CR were consistently detected at all sampling points. In contrast, CR of cortisol during PLHB and NLHB was observed in a few cases, although considerable CR was noted in most of the Cont cases. The variations in renin activity indicated CR in most of the Cont cases and in all cases at all sampling points during PLHB and NLHB, whereas their acrophases were diversified. In conclusion, the CR of melatonin, reflecting the fundamental circadian clock, was maintained during both PLHB and NLHB, while it could be modified for stress sensitive cortisol and hemodynamic responsive renin during these bypass modalities.