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Biomedical subjects

J Benes

Publications and source records attributed to J Benes.

At least 55 records · Page 3Linked to original sources
PubMed1989

[A simple model for verifying the effects of a focused shock wave from our generator on erythrocytes and lymphocytes].

Biological effects of the focused shock wave produced by the generator of our own construction were observed on the erythrocyte and lymphocyte suspension as a model. Erythrocyte haemolysis located into the small volume of the 1.4 ml focus was observed in the dependence on the number of shocks. After 10 shocks it does not exceed 15%. In the previous experiments this particular dosage caused a complete destruction of the bile stone of about 1 cm size. Increase of kalium concentration in correspondence to the degree of haemolysis was discovered in the erythrocyte suspension. Effects of shock wave were observed also in lymphocytes, where no change of blastic transformation in the decrease of the life span approximately by 2% was proved. Regular measurements proved minimum damage of blood cells in given experimental conditions and the results are comparable with biological effects of other sources of the focused shock wave.

Erythrocytes↗
PubMed1984

Intravenous disopyramide: safety and efficacy of a new dosage regimen.

The efficacy and safety of a new dosage regimen of intravenous disopyramide in ventricular arrhythmias were evaluated in 10 patients. Each had at least four premature ventricular contractions (PVCs)/min during a 30-min period before dosing. By the classification of Lown et al., grade III arrhythmia was present in four patients, grade IVA in three patients, and grade IVB in three patients. Disopyramide was injected intravenously as a bolus of 0.5 mg/kg over 5 min. Each patient received two to three additional boluses of same strength with 5-min intervals between each dosing during the first hour. Continuous intravenous infusion was started with the first bolus and continued at a rate of 1 mg/kg/hr for 3 hr and at 0.4 mg/kg/hr for 15 hr. All patients had continuous Holter monitoring throughout the 18-hr treatment period and for 30 to 60 min before treatment. In eight patients the grade of arrhythmia after drug decreased and the frequency of PVCs fell by 70% to 100% (greater than 85% in six patients and less than 85% in two patients), and the response persisted during the continuous infusion. In two patients PVC frequency increased. For the group as a whole, PVC frequency decreased on the average by 68.4%. Therapeutic serum levels (greater than 2 micrograms/ml) were reached after the first or second bolus and were maintained during the continuous infusion period. There were no side effects necessitating termination of disopyramide infusion. The dosage regimen of intravenous disopyramide evaluated was effective in 60% of patients with ventricular arrhythmia, induced no severe toxic effects, and rapidly achieved therapeutic serum levels that were maintained during continuous infusion.

Adult↗
PubMed1983

[The effect of ultraviolet irradiation on the protozoan Tetrahymena pyriformis].

A number of trials was conducted to test the effect of ultraviolet radiation on the protozoan Tetrahymena pyriformis, strain W. The material was cultivated in a culture medium and in a deficient experimental medium, the radiation flux being 90 to 5400 J/m2 in the logarithmic and stationary stages of population growth. As found, the culture medium has a protective effect against ultraviolet radiation, owing to an increased peptone content. The cells in the stationary stage of growth are more resistant to ultraviolet radiation than cells in the logarithmic stage of growth. The studied intensities of radiation did not damage the nutrients contained in the medium.

Tetrahymena pyriformis↗
PubMed1981

[Use of the protozoan Tetrahymena pyriformis in testing for contamination of biological materials with organophosphates and carbamates].

The medium consisting of 1% protease-peptone with 0.2% yeast extract proved to be suitable for slant culture of the protozoon Tetrahymena pyriformis. PPY medium is optical for obtaining high cell densities under cultivation in Roux flasks. To evaluate the toxicity the cell number was determined by direct counting in Fuchs-Rosenthal chambers, following 24, 48 and 72-hr incubation period. LD50 for trichlorphon was determined up to 4.0 to 5.0 mg . 1(-1), LD100 within the range of 19.58 to 39.16 mg . 1(-1), LD50 for dichlorvos as 5.0 mg . 1(-1), LD100 as 19.58 to 39.16 mg . 1(-1), for model carbamate (eserine) LD50 was determined up to 25.0 to 50.0 mg . 1(-1), LD100 over 200.0 mg . 1(-1).

Carbamates↗