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Biomedical subjects

K Vondra

Publications and source records attributed to K Vondra.

At least 55 records · Page 3Linked to original sources
PubMed1986

Effect of sleep deprivation on cholesterol metabolism and triglyceridaemia in male volunteers.

The effect of 5-day sleep deprivation (SD) on cholesterol metabolism, together with triglyceridaemia, was studied in seven healthy male volunteers. A 3-day control period was followed by 5 days (120 h) complete SD and 4 days recovery. Blood was collected at 9 a.m. and at 9 p.m. Vastus lateralis muscle biopsy was performed during the control period, on the 5th day of SD, and on day 3 of recovery. The value of muscle cholesterol was related to the non-collagen protein content. The plasma triglycerides (TG) varied in a circadian biorhythm, the amplitude of which declined gradually during SD. The morning triglyceridaemia was significantly decreased on days 3-5 of SD (35%-79% of initial values). On days 4 and 5 of SD, plasma cholesterol fell significantly to 78% and 88% of control values, respectively. The ratio of its esterified to unesterified fractions remained unchanged throughout SD. Basal activity of lecithin cholesterol acyltransferase (LCAT) showed no diurnal biorhythm; on the last 2 days of SD, LCAT activity fell significantly to 71%-80%. In contrast, the decrease in fractional esterification rate (FER) was insignificant. In the vastus lateralis muscle, total cholesterol (TC) was decreased by 40% at the end of SD, the reduction being greater for cholesterol esters (CE) (by 63%) than for free cholesterol (FC) (by 36%). The relative proportion of CE significantly decreased from an initial 14.7% to 9.2% on the last day of SD. During recovery after SD, plasma cholesterol and TG slowly returned to normal. LCAT activity and FER recovered quickly, within 48 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

The plasma cholesterol concentration and cholesterol esterification rate in patients with stage I-III arterial hypertension.

Disorders of cholesterol metabolism were studied in 88 patients with essential or renovascular hypertension, among whom the individual stages of the disease, classified by WHO criteria, were evenly represented. The results were compared with the findings in a group of 87 healthy controls. The following were determined in the plasma: the total (TCH) and free (FCH) cholesterol concentration, triglycerides (TG) and lecithin cholesterol acyltransferase (LCAT) activity, defined as the molar esterification rate (MER). The MER/FCH ratio gave the fractional esterification rate (FER) as the percentage per hour. In evaluation of the whole group of hypertensive patients, the mean TCH values were found to be raised (6.62 as against 6.05 mmol/l, P less than 0.05), but FCH levels were raised more significantly (mean 1.76 as against 1.51 mmol/l, p less than 0.001). With normal MER values, the hypertensive group had a significantly lower mean FER value (5.45 as against 6.27 %/h, p less than 0.001). Mainly patients with stage II and III hypertension accounted for the reduced rate of cholesterol recirculation between plasma and tissues (i.e. the FER value). The findings indicate that a change from stage I to stage II hypertension is accompanied by an increased incidence of lipid metabolism disorders.

Cholesterol↗
PubMed1985

The relationship between anaerobic performance and muscle metabolic capacity and fibre distribution.

Relationships between functional anaerobic indicators and the character of cellular muscle energy metabolism were studied. Twelve untrained male students were tested by a specific anaerobic test on the treadmill. The mean values of the anaerobic test were as follows: blood lactate 10.69 mmol . 1(-1), running speed 16.08 km . h-1 and duration 92.67 s. The average distribution of muscle fibres (m. vastus lateralis) was: type I 52.2%, type II A 29.0% and type II B 18.8%. The mean enzyme activity values were: triosephosphate dehydrogenase (TPDH) 4.67 mu kat . g-1 w.w., lactate dehydrogenase (LDH) 5.76 mu kat . g-1 w.w, citrate synthase (CS) 0.21 mu kat . g-1 w.w. and hydroxyacyl-CoA dehydrogenase (HAD) 0.12 mu kat . g-1 w.w. Significant negative correlations were found between delta LA and CS (r = 0.64) and % of fibre type II B and CS (r = 0.78) and positive correlations between % of fibre type I and CS and/or HAD (r = 0.60 and r = 0.62, respectively).

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1985

Serum linoleic acid and cardiovascular death in postinfarction middle-aged men.

Linoleic acid in serum total lipids was the first variable in the stepwise regression analysis of metabolic, nutritional and cardiovascular factors in a secondary preventive study of postinfarction middle-aged men. It was followed in the regression analysis where the dependent variable was cardiovascular death by previous myocardial infarction, heart volume index and hyperlipoproteinaemia. Linoleic acid was the only fatty acid entering the regression. Unlike other fatty acids, it exhibited by its low percentage an accumulation of deaths. The decreased percentage of linoleic acid was also evident in the comparison of fatty acid patterns of cardiovascular deaths to age- and triglyceride-matched men free from ischaemic heart disease. This study confirms prospective associations found in previously healthy men. Conclusions are drawn about the relevance of low serum linoleic acid to long term prognosis after MI.

Cardiovascular Diseases↗
PubMed1985

Fractional cholesterol esterification rate and muscle cholesterol of healthy young men.

A group of fourteen healthy young male volunteers was examined to define more exactly the relations between lecithin cholesterol acyltransferase activity (LCAT), fractional cholesterol esterification rate (FER), total cholesterol (TC) and its free and esterified fractions (FC, CE) in skeletal muscles under physiological conditions. The mean values (+/- S.D.) of LCAT activity (95.4 +/- 16.3 mumol .1(-1) per hour), and FER (7.45 +/- 1.54% per hour) corresponded to published data on normolipidaemic healthy men of normal body weight. The mean value of TC in muscles was 332 +/- 83 micrograms per 100 mg of non-collagen protein, of which 14 +/- 7.4 per cent was formed by cholesterol esters. There was positive correlation between TC in muscles and age. Significant positive correlations between FER and the content of esterified cholesterol in muscles, and between FER and the proportion of esterified to total muscle cholesterol were found. These results suggest a close interrelation of cholesterol ester metabolism in the plasma and in slow pool tissues.

Adult↗