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Biomedical subjects

F Valić

Publications and source records attributed to F Valić.

At least 37 records · Page 2Linked to original sources
PubMed1977

Effects of fluorocarbon propellants on respiratory flow and ECG.

Ten subjects were exposed to the propellants freon 11, freon 12, freon 114, to two mixtures of freon 11 and 12 and to a mixture of freon 12 and 114. The length of exposure was 15, 45 or 60 seconds. Maximum expiratory flow-volume (MEF) curves and ECG were recorded before, and intermittently up to 1 hour after, exposure. Breathing level concentrations of propellants during exposure were determined by gas chromatography. All freons induced biphasic reduction of ventilatory capacity on inhalation. The first fall occurred within a few minutes of exposure while the second was delayed 13-30 minutes after exposure. The effects of mixtures were greater than those of individual freons. The relative fall in MEF 75% was more pronounced than that in MEF 50%. No clear-cut pathological changes in ECG were found. Nevertheless, most subjects developed variations in heart rate exceeding those noted before exposure. In a few cases inversion of the T wave, and in one case atrioventricular block, were observed.

Adult↗
PubMed1976

Respiratory response to tobacco dust exposure.

Results of a study of the respiratory responses of 318 nonsmoking female workers to long-term tobacco dust exposure are reported. The mean total tobacco dust concentrations ranged from 0.9 to 27.5 mg per m3; the respirable fraction, from 0.3 to 3.6 mg per m3. The mean length of exposure to tobacco dust was 14.9 years; 24 per cent of the workers had been exposed to tobacco dust for 20 years or more. Comparatively low prevalences of chronic respiratory symptoms were found, and only the prevalences of chest tightness and wheezing were significantly higher among workers exposed to tobacco dust than those of the control group (P less than 0.01). Calculating the expected 1-sec forced expiratory volume and forced vital capacity values by means of multiple linear regression equations, developed on the basis of data obtained in the 210 control subjects, revealed no significant differences between the measured and expected ventilatory capacity values among any of the groups of the workers observed. In contrast to negative findings with regard to chronic respiratory effects, significant acute decreases in ventilatory capacity during the work shift were recorded. No dose-response relationship was found between the level of exposure and the acute decreases in ventilatory capacity.

Adolescent↗
PubMed1975

Lung function in textile workers.

Acute changes in ventilatory function during a workshift with exposure to hemp, flax, and cotton dust were measured on Mondays in a group of 61 textile workers, all working on carding machines. In addition, single-breath diffusing capacity (DLCOSB) was measured before dust exposure on Monday in 30 of the 61 workers. Large acute reductions during dust exposure were recorded in maximum expiratory flow rate at 50% VC (MEF50%), ranging from 38 to 22%. Acute reductions of FEV1-0 were considerably smaller, ranging from 17 to 9%. There was a statistically significant increase in residual volume (RV) with very small and insignificant changes in total lung capacity (TLC). Although preshift FEV1-0 and FVC were decreased, DLCOSB was within normal limits. Plethysmographic measurements in six healthy volunteers exposed to hemp-dust extract confirmed the results obtained in textile workers, that is, that TLC does not change significantly during dust-induced airway constriction and that maximum expiratory flow rate at 50% VC (MEF50%) is a more sensitive test than FEV1-0 in detecting acute ventilatory changes caused by the dust extract.

Adult↗
PubMed1975

Change in the respiratory response to coarse cotton dust over a ten-year period.

Changes in respiratory function during a 10-year period were studied in a group of 34 men and 19 women exposed to coarse cotton dust. The prevalence of byssinosis increased significantly in the 10-year period both in men and women; in addition, there was an increase in the prevalence of all other chronic respiratory symptoms in 1973 compared to 1963. There was a significant decrease in forced expiratory volume in 1 sec and forced vital capacity over the Monday shift both in 1963 and 1973. In subjects who were without byssinosis in 1963 but who had developed it by 1973, there was a considerable decrease in forced expiratory volume in 1 sec in 1973. The mean annual decline of forced expiratory volume in 1 sec (70 ml) during the 10-year period in the men was much greater than expected on the basis of the prediction equation for normal males, and it was most pronounced in those with byssinosis at the time of both surveys (111 ml).

Adult↗