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H Ohnaka

Publications and source records attributed to H Ohnaka.

4 recordsLinked to original sources
PubMed2001

Effects of cocaine and ethanol on mouse fetuses.

In the presence of ethanol, cocaine is metabolized to its ethyl homolog, cocaethylene. To investigate the embryotoxic effects of cocaethylene, pregnant ICR mice receiving ethanol orally during pregnancy were treated with 50 mg/kg/day cocaine i.p. on days 7, 8 and 9 of gestation. Treatment with either cocaine or ethanol alone did not affect the fetal mortality rate or the mean fetal body weight. Concurrent cocaine and ethanol treatment increased the fetal mortality rate, and decreased the mean fetal body weight, although teratogenicity was not noted. These results suggest that concurrent use of cocaine and ethanol during pregnancy is more harmful to fetal body weight gain and their lives than the use of either drug alone, at least in the present experimental settings.

Animals↗
PubMed1994

Excellent prognosis of Japanese patients with chest pain and normal or nearly normal coronary arteries--2- to 13-year follow-up of 274 patients after coronary cineangiography.

Although the prognosis of patients with chest pain and normal coronary arteries is reportedly good in the Western literature, it is unclear in Japan. The purpose of this study was to examine the natural history of 274 consecutive patients with chest pain and normal or nearly normal coronary arteries, and to determine whether the possibility of minor coronary artery disease has clinical implications as a prodromal factor of other heart diseases. Six of the patients died during the mean observation period of 6 years (74.5 +/- 35.4 months): 2 cancer, 3 cerebro-vascular accident, and 1 renal failure death. Three additional patients suffered from nonfatal cerebro-vascular accidents. Eleven patients were readmitted for evaluation of chest pain, and 4 of these were diagnosed as having vasospastic angina. Progression of significant coronary artery disease was not detected in these 11 patients with repeated coronary angiography. None of the patients in this study developed fatal or nonfatal myocardial infarction. A small number of patients (36/240, 15.0%) continued to suffer from chest pain. None of the patients developed cardiomyopathies or valvular heart diseases. Our observations indicate that the prognosis of chest pain with normal or nearly normal coronary arteries is better than that presented in the Western reports.

Adult↗
PubMed1993

Role of oligomeric interactions in the cooperativity of crayfish hemocyanin.

To examine the effect of interactions between the hexameric units in the dodecameric hemocyanin, crayfish (Procambarus clarki) hemocyanin was partially dissociated. Gel-filtration yielded fractions containing the undissociated dodecamer and a mixture of the hexamer and heptamer (referred to as 'half-dodecamer'). Their O2 equilibria were compared and were analyzed by curve fitting of cooperativity models. The partial dissociation of the dodecamer significantly lowered the cooperativity but little affected the O2 affinities. The O2 equilibrium of the half-dodecamer could be described by the two-state allosteric model of Monod-Wyman-Changeux on the assumption that the cooperative unit is composed of six subunits. We tested the applicability of allosteric models for the dodecamer that deal with the interactions between the hexamers. To reduce the arbitrariness of the fitting, we presumed that some parameters are equal to the two-state model parameters for the half-dodecamer. It was found that the 'nesting model', which assumes allosteric equilibria at two different hierarchical levels, could be applied successfully to the dodecamer.

Animals↗