Vascular compliance studies in awake total artificial heart implanted calves.
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Biomedical subjects
Publications and source records attributed to K Kaku.
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Three vasoactive drugs--glucagon, acetylcholine and dopamine were used in calves with an implanted TAH to study their mere vascular effects. We noticed that glucagon, besides being a potent vasodilator, affected the vascular system gradually rather than instantly. Also, it allowed for the gradual recovery of the system, thus avoiding sudden fluctuations in systemic and pulmonary blood pressures. Glucagon was found to have a unique capability of decreasing vascular resistance with only a slight drop in systolic pressure. Acetylcholine action was rather instant, exhibiting a sudden fall in both systolic and diastolic blood pressures. In animals with a TAH, dopamine seemed to work differently from that in subjects with an intact natural heart. While many investigators failed to see any change in pulmonary vascular resistance due to dopamine injection in subjects with an intact natural heart, we noticed about 20% increase in pulmonary vascular resistance (with a dose of 10 muGm/Kg). However, at low dosages of dopamine, we did not notice any appreciable change in pulmonary vascular resistance, which suggests that its action is dose dependent. We tend to believe that glucagon offers promising results in controlling the pulmonary hypertension in calves with a TAH. It is, also, our opinion that further investigation on the vascular effects of dopamine would reveal more pertinent and interesting results and solve the existing discrepancies.
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A response to diethylstilbestrol (DES) of DES-induced renal carcinoma in Syrian hamster was studied by comparing subcutaneous growth of this tumor in DES-treated and untreated animals with respect to the growth curve, cell cycle time, Tc, growth fraction, GF, and cell loss factor, phi. In both conditions the tumor growth followed the Gompertz curve, but the latent period was 14 days longer without DES than with DES. In the untreated animals, Tc was 80% longer due to increases of TGl and TS. However, phi was not changed significantly and GF rather increased without DES. It was concluded that DES-dependency of this tumor growth was manifested in the prolongation of Tc.
Adecrease of about 463 000 live births occurred in Japan in 1966, constituting a sharp departure from the linear trend before and after. This was partly caused by contraception and partly by induced abortion. The induced abortion rate, 43.1 per 1000 births in the year (a total of 65 000), was significantly higher than the 30.6 expected (46.200 total) from the regression trend computed from the years 1963 to 1969. No epidemics were reported in 1966 which might have caused the increase in abortion. It is more likely to be due to observance of Hinoe-Uma (Elder Fire-Horse), which comes round every sixty years by zodiac almanac. This event represents a superstition observed only by the Japanese, in whcih it is a bad omen for female babies to be born in the year. 1966 was the most recent year of Hinoe-Uma.
Although it was expected by observers in Japan that the potency of belief in the superstition of the year of Fire-horse would be made apparent by a decrease in births and an increase of the induced abortion rate, an increase of infant mortality rate was not anticipated. However, an analysis of the early neonatal mortality rate of accidents and violence revealed a remarkable increase for girls but not for boys in 1966, the most recent year of Fire-horse. This fact is consistent with the superstition that women born in the year of Fire-horse are ill-fated.
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The effects of tolbutamide and pancreatic hormones on liver fructose-2,6-bisphosphate (F-2,6-P2) formation were examined using isolated rat hepatocytes. Glucagon decreased the F-2,6-P2 level in a dose-dependent manner. Insulin (greater than 10(-9) M) increased the F-2,6-P2 level reduced by glucagon (less than 10(-9) M), but did not show a stimulatory effect on this activator formation in the absence of glucagon. On the other hand, tolbutamide increased the F-2,6-P2 level in hepatocytes regardless of the presence or absence of glucagon. Tolbutamide (2 mM) stimulation on liver F-2,6-P2 formation was enhanced by the concomitant addition of insulin (10(-8) M) in the presence of glucagon (3 X 10(-11) M). These observations suggest that the regulatory effect of tolbutamide on liver F-2,6-P2 level is independent of that of insulin.
BACKGROUND: In Japan, vascular dementia (VD) has been responsible for the majority of all dementia cases in both epidemiological and neuropathological studies. Recently, however, several epidemiological investigations have shown that the rate of VD has decreased and senile dementia of the Alzheimer type (SDAT) is now the major cause of dementia, though few neuropathological investigations show that the majority of dementia is SDAT. OBJECTIVE: The purpose of the study was to clarify the rates of dementia types in Japanese nursing home residents and to compare the ratio of SDAT to VD in the first and second halves of the study. METHODS: One hundred and twenty-two demented nursing home residents (48 men and 74 women) were evaluated neuropathologically over a period of 17 years in Shimane prefecture, Japan. All subjects died between 1976 and 1992. The average age at death was 81.4 +/- 9.4 years for men, 85.0 +/- 7.2 for women and 83.6 +/- 8.3 for total samples. RESULTS: In classifying dementia type, SDAT accounted for 34% (41 cases); VD 35% (42); mixed dementia 11% (14); and 'other' dementia 20% (25) of all samples. Comparison of the first 9-year period with the second 8-year period revealed the ratio of SDAT to VD tended to increase (from 0.83 to 1.15). This increasing tendency was found both in men (from 0.53 to 0.7) and in women (from 1.13 to 1.44). These tendencies, however, were not statistically significant. CONCLUSION: There was no change statistically in the ratio of SDAT to VD between the first half of the study and the second half. However, there was an increasing tendency of the ratio in our study.
In this multicentre, non-randomized clinical study, 35 hypertensive patients with concomitant non-insulin-dependent diabetes mellitus were treated with the selective alpha 1 adrenoceptor blocker doxazosin mesilate for 24 weeks, either alone or together with existing antihypertensive therapy. The effects of the drug on blood pressure, glucose and lipid metabolism were examined. Daily administration of 0.5-8 mg doxazosin caused a significant reduction in both systolic and diastolic blood pressure decreased from 172 +/- 15/90 +/- 11 mmHg at the beginning, to 149 +/- 19/80 +/- 12 mmHg at the end of the trial. Heart rate was not affected. The plasma glucose level showed no change, whereas the haemoglobin A1c level decreased significantly from 7.4 +/- 1.2% to 7.1 +/- 1.2% (P < 0.01). Total and high-density lipoprotein cholesterol levels remained unchanged. The triglycerides level, however, decreased from 113 +/- 54 mg/dl at the beginning to 98 +/- 49 mg/dl at the end of the trial (P < 0.05). In a subgroup of patients, who showed hypercholesterolaemia ( > or = 220 mg/dl, n = 9) at the beginning, the total cholesterol level decreased from 252 +/- 33 mg/dl to 220 +/- 33 mg/dl (P < 0.05). Two patients complained of abdominal fullness or diarrhoea, but both were easily manageable. The results indicate that doxazosin is effective and safe in the treatment of hypertension in non-insulin-dependent diabetics and does not affect glucose metabolism. As for lipid metabolism in non-insulin-dependent diabetic patients, doxazosin seems to have a beneficial effect.
Thirty-nine patients with diabetes and hypertension were treated with indapamide for 24 weeks to study the effects of that drug on glucose and lipid metabolism. The drug was administered at a dose of 2 mg once per day in the morning as a single drug (26 patients) or in combination with other antihypertensive drugs (13 patients), including calcium antagonists, angiotensin-converting enzyme inhibitors, an alpha-blocker, or a beta-blocker. Blood pressure was reduced in both groups during treatment, and no alteration of glycemic control or lipid metabolism was observed. One patient complained of a mild headache, but treatment was continued. The results indicate that indapamide is useful for the long-term treatment of hypertension in diabetic patients, either alone or in combination with other antihypertensive agents.