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Biomedical subjects

S Tao

Publications and source records attributed to S Tao.

139 records · Page 8Linked to original sources
PubMed1983

Measurement of effects of the Chinese herbal medicine higenamine on left ventricular function using a cardiac probe.

The effects of the Chinese herbal medicine higenamine on left ventricular function were studied by means of an external radiation detector in 15 patients with heart disease. Higenamine, administered intravenously, markedly increased the ejection fraction of LV, as well as the ejection rate. The LVEF increased from 46% +/- 9% to 60% +/- 15% and 61% +/- 12% (P less than 0.005) after a 30- and 60-min infusion of higenamine, respectively. The percentage increase in LVEF paralleled the increase in the heart rate. The effects of higenamine on LV function were similar to the response obtained with isoproterenol. These results document the pharmacologic effect of the Chinese herbal medicine, higenamine, on heart function.

Adult↗
PubMed1976

Evidence for a lack of an effect of dietary fluoride level on reproduction in mice.

The possible essentiality of fluoride for reproduction was studied in female mice fed a low-fluoride ( less than 0.5 ppm F) basal diet for three generations. Reproduction of mice fed this basal diet was the same as when mice were fed the basal diet supplemented with 2 or 100 ppm F. A previous study [Messer et. al. (1973) J. Nutr. 103, 1319-1326], utilizing the same diet did result in an impairment of reproduction and the development of an anemic condition. The results of the present study suggest that the apparent essentiality of fluoride previously observed was due to a pharmacological effect of fluoride in improving iron utilization in a diet marginally sufficient in iron. The data do not support the previous claims of an essential role of fluoride in reproduction.

Animals↗
PubMedDate not supplied

Ethanol-clonidine hemodynamic interaction in normotensive rats is modified by anesthesia.

Our previous findings have shown that ethanol attenuates the decreases in plasma norepinephrine (NE) levels, and blood pressure elicited by centrally acting antihypertensive drugs in spontaneously hypertensive rats (SHRs). The present study investigated whether this interaction can be influenced by baseline blood pressure (BP) and sought direct evidence to support the involvement of the SNS by recording the sympathetic neural activity (SNA) of the splanchnic nerve. The conscious aortic barodenvervated (ABD) rat model was utilized because it exhibits greater hypotensive responses to clonidine compared with sham-operated (SO) rats. Although ABD and SO rats (332 + 33 vs. 227 + 18 pg/ml). Clonidine (30 micrograms/kg, i.v.) elicited significantly greater decreases in mean arterial pressure (MAP; -20.0 + 2.1 vs. -10.4 + 0.8 mm Hg) and plasma NE (-194 + 26 vs. -50 + 11 pg/ml) in conscious ABD vs. SO rats. Ethanol (1 g/kg, i.v.) reversed clonidine-evoked decreases in BP and plasma NE levels, but the interaction was more prominent in ABD rats. To support the hypothesis that the interaction occurs within the CNS, the effect of ethanol was studied on clonidine-evoked decreases in preganglionic SNA and BP in anesthetized rats. In contrast to its effects in conscious rats, ethanol augmented both the hypotensive and sympathoinhibitory responses to clonidine in anesthetized rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMedDate not supplied

Exposure limits for ultra-short wave radiation in work environments.

Exposure limit values for ultra-short wave radiation of humans were derived on the basis of epidemiological survey and experimental exposure of rabbits. Eighteen male rabbits were divided into 4 groups randomly. Three groups were irradiated with ultra-short waves (100 MHz) at 35, 1.5-3.5, and 0.07 mW/cm2 power density in an E-polarized TEM Cell at 24 +/- 4 degrees C ambient temperature. The last group in a sham chamber served as controls. Irradiation was performed 3 hours per day, 5 days per week for 24 weeks. Thermal effects occurred in the group irradiated at 35 mW/cm2. The thermal threshold limit value was set at 1.5 mW/cm2. An epidemiological survey was carried out on 136 factory workers and TV operators exposed over one year to ultra-short wave radiation at 0.2 mW/cm2. They were compared with 108 controls. The only complaint of the exposed group was neurosis. The exposure limit value (ELV) to short wave radiation was set at 0.2 mW/cm2 by using a 15- and 20-fold safety factor.

Animals↗
PubMedDate not supplied

Modeling the fate of benzo[a]pyrene in the wastewater-irrigated areas of Tianjin with a fugacity model.

A Level III fugacity model was applied to characterize the transfer processes and environmental fate of benzo[a]pyrene in wastewater-irrigated areas of Tianjin, China. The physical-chemical properties and transfer parameters of benzo[a]pyrene were used in the model and the concentration distribution of benzo[a]pyrene in sediment, soil, water, air, fish, and crop compartments, as well as transfer fluxes across the compartments, were then derived under steady-state assumptions. The calculated results were compared with monitoring data for air, soil, water, and sediment collected from the literature. The results indicate that there was generally good agreement and the differences were within an order of magnitude for air, soil, and sediment. The concentration of benzo[a]pyrene in the ambient air in the area was very low with a majority present sorbed to aerosol. In the water compartment, approximately 70% of benzo[a]pyrene dissolved in water phase. Relatively high concentrations of the compound were found in the soil and sediment, with the soil serving as the dominant sink in the area. Benzo[a]pyrene, with a slow metabolic rate, was found to accumulate in fish in the area.

Aerosols↗
PubMedDate not supplied

A comparison of the fragment constant and molecular connectivity indices models for normalized sorption coefficient estimation.

Fragment constant and molecular connectivity indices models were developed based on the measured normalized sorption coefficient values of 592 chemicals. The two models were compared for precision in terms of their adjusted coefficients of determination and their mean residuals. Model robustness was evaluated and compared using jackknifed mean residuals derived from class-by-class deletion. Results indicated that a relatively greater precision could be achieved using the fragment constant approach compared with the molecular connectivity indices model. The adjusted coefficients of determination of the two models were 0.965 and 0.765 and the mean residuals were 0.366 and 0.440, respectively. Although there were a relatively small number of independent variables involved, the robustness of the molecular connectivity indices model was greater than that of the fragment constant method as far as extrapolation among chemical classes is concerned.

Adsorption↗