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Biomedical subjects

J Zejda

Publications and source records attributed to J Zejda.

17 recordsLinked to original sources
PubMed1995

[Examination of health effects from exposure to metallic mercury in workers employed in production of chlorine and aldehyde. II. Assessment of kidney lesions].

A group under study embraced 73 workers involved in the production of acetic aldehyde, 74 workers of the department of chlorine and 13 retired workers with past poisoning by mercury. The control group consisted of 40 persons. Examinations performed in all subjects were designed mainly to assess the kidney lesions. The following results were obtained: Simple markers of kidney lesions (functions) such as urine standard examination, concentration of creatinine and glomerular filtration did not reveal clear-cut symptoms of metallic mercury nephrotoxic effect. In persons exposed to mercury an increased activity of lysosomal enzyme--beta-N-acetylglucosaminidase (beta-NAG) in urine was found. The activity of this enzyme showed correlation with actual mercury excretion in urine. A lack of correlation between beta-NAG activity and the index of cumulated urine excretion of mercury and the duration of exposure to mercury as well as low activity of this enzyme in the group of retired workers and pensioners with past poisoning by mercury suggest that the increase of beta-NAG activity is an reversible phenomenon. The value of determination of beta-2-microglobulin concentration in urine in persons currently exposed to mercury is doubtful because of the degradation of this protein resulting from urine acidification. The prolongation of secretory and excretory phase found in the renovasographic examination indicates the value of this method in the evaluation of kidney lesion in persons exposed to metallic mercury.

Acetylglucosaminidase↗
PubMed1991

Fissural thickening and exposure to asbestos: occurrence, determinants, and functional impact.

The occurrence and determinants of thickened interlobar fissures were assessed in 147 insulators, in order to test the hypothesis that radiographic abnormalities in minor (FMN) and/or major (FMJ) interlobar fissures are associated with restrictive respiratory impairment, which may reflect early parenchymal lung fibrosis. According to the diagnostic criteria developed, definite interlobar thickening was found in 33 (FMN) and in 73 (FMJ) men, and was frequently associated with the presence of classical asbestos pleural disease, though not parenchymal abnormality. Multivariate analyses did not demonstrate any association between either FMN or FMJ and lung function. Such an association, however, was found in the case of the usual asbestos-related pleural change. These findings suggest that fissural thickening seen on chest radiography represents a component of asbestos pleural disease and not asbestosis.

Adolescent↗
PubMed1989

Diagnostic value of exercise testing in asbestosis.

The diagnostic value of simple exercise testing was examined in 81 current male asbestos-cement workers, divided into four groups according to the International Labour Office (ILO) category of irregular opacities: 0/0, 25; 1/1, 24; 1/2, 22; and 2/2, 10 men. An increasing X-ray score was accompanied by more severe functional abnormality in keeping with the development of a restrictive defect. Symptom-limited oxygen uptake (VO2SL) did not depend on the X-ray grade and was 76.7, 71.9, 68.7, and 73.5% pv, respectively, for the four groups. Subjects with ILO score 1/1 had significantly higher exercise ventilation at O2 uptake of 1.01.min-1 (VE 1.0) than those with grade 0/0. End-exercise tidal volume (VTSL in 1) decreased with an increasing X-ray score: 2.14, 1.98, 1.85, and 1.62, respectively. VTSL standardized for vital capacity (VTSL/VC) followed the same pattern. Asbestosis was diagnosed in 25 men, in whom VE 1.0 was significantly higher (p less than .02) and VTSL lower (p less than .01) than in the 0/0 group. VO2SL was similar in both groups. The findings suggest that VE 1.0 and VTSL may be early functional indicators of asbestos-related interstitial lung fibrosis. The measurement of both exercise indices may increase the certainty of clinical diagnosis of asbestosis in subjects with less advanced disease.

Adult↗
PubMed1989

Circadian variations in psychophysiological responses to heat exposure and exercise.

Ten healthy men were tested at 0600, 1200, 1800 and 2400 hours on different days at rest in a laboratory at room temperature followed by 1 h of heat exposure in a climatic chamber at 42 degrees C, 60% rh (50 min rest and 10 min exercise on a cycle ergometer at 50% VO2max). Heart rate, blood pressure, rectal temperature Tre, metabolic rate, number connection test, visual and auditory reaction time, flicker test and catecholamine excretion were measured. Heat exposure and exercise caused lower heart rate acceleration at 2400 hours than at 0600 and 1200 hours, the smallest increase of Tre at 1800 hours, and an increase in metabolic rate greater at 1200 than at 1800 hours. In the afternoon, when, according to the circadian rhythm, the body temperature is highest, the additional heat load produced the smallest physiological effects. Performance efficiency, after heat exposure combined with physical exercise, improved slightly, but diurnal variations did not show significant circadian rhythm.

Adult↗
PubMed1989

Validation of clinical criteria for diagnosing asbestosis in asbestos-cement workers.

The recently developed diagnostic criteria for asbestosis, including chest x-ray abnormalities and respiratory impairment consistent with interstitial lung fibrosis, were tested in 550 current asbestos-cement workers. The findings showed the correlation of x-ray ILO/UC scores for small irregular opacities (s, t, u) with duration of exposure, especially evident in relation to category of 1/2 and above ("cutoff category") detected in 48 subjects. An increasing x-ray score was accompanied by more functional abnormality, demonstrated by a restrictive defect in ventilation, followed by a fall in arterial oxygen pressure on exercise and impaired diffusing capacity. Amongst subjects working for at least 10 years, thirty met the roentgenographic and functional criteria for asbestosis. On the basis of these criteria, asbestosis could be diagnosed only in one subject employed for not longer than 5 years and two others working for not longer than 9 years, which can be explained by a false--positive effect.

Asbestos↗
PubMed1989

[Usefulness of the exercise test with measurement of symptom-limited oxygen consumption (V02SL) in evaluating exertion tolerance in patients with chronic pulmonary diseases].

An analysis on objectiveness of assessing symptom limited oxygen consumption (VO2SL) registered during exercise tests of increasing load of 30W every 3 minutes in 86 patients with chronic pulmonary diseases and 30 healthy control subjects. 36 did not have any ventilatory disorders, 50 had lowered ventilatory efficiency. VO2SL differed significantly in both study groups and the control. It was 1.80 L x min-1 in patients without ventilatory disturbances, 1.52 L x min-1 in patients with ventilatory disturbances and 2.12 L x min-1 in the control. The test was exceptable. In most of the subjects the results were repeatable, correlation indexes between the first and next assessment was 0.88, 0.95 and 0.83. Variance analysis did not differ between groups. The study demonstrated usefulness of VO2SL in determining exercise tolerance and in diagnosing patients with chronic pulmonary diseases.

Chronic Disease↗
PubMed1989

[Comparison of two exercise tests with various loads].

In 30 males of a mean age 45.6 years suspected of asbestosis the author compared maximal oxygen consumption symptom limited, ventilation during consumption of oxygen (1 L per min) VE1.0 pulse rate on this level (HR1.0) and respiratory volume during ventilation 30 L X min.-1 (VT30) registered during exercise tests with an increasing load of 30 W every 3 minutes (group A) and 15 W every 1 minute (group B). Although both tests were judged to be equally stsrenuous the B test was shorter by one third and produced significantly higher VO2SL 1.89 L X min.-1, A: 1.71 L X min.-1 (p 0.01). Important diagnostical tests evaluating respiratory VE1.0, VT30 and circulatory (HR30) cost did not differ between groups. The author corroborated earlier studies that VE1.0 is one of the most sensitive tests of unequal ventilation and/or diffusion disorders in patients with slightly abnormal respiratory parameters: VC = 83% pred. FEV = 84% pred., FEV1% = 71%, DLCO = 82% pred. The results of this study show that test B is better than test A, being mich better tolerated.

Adult↗
PubMed1988

Lung function impairment as a guide to exercise limitation in work-related lung disorders.

The hypothesis that exercise limitation of respiratory origin can be predicted accurately from the lung function impairment has been tested using maximal oxygen uptake (VO2max) as the dependent variable in a multiple regression analysis. The subjects were 157 men who met objective criteria for exercise being limited by respiratory impairment. VO2max (mean value, 1.38 L min-1) was described by FEV1 and single-breath lung transfer factor (diffusing capacity) for carbon monoxide (TL') singly or in combination, but the accuracy was poor (at best, standard error of the estimate, 0.36 L min-1; r2, 29.1%). FEV1 could be replaced by FVC and FEV1/FVC. Description of VO2max was improved by also including in the equation the variables age, fat-free mass, and submaximal exercise ventilation (VE). Transfer factor did not then contribute significantly. VO2max as percent of predicted (mean value of 60%) was described by %FVC or %FEV1, but the accuracy was poor (SEE, 16.0%; r2, 14%). Prediction was improved somewhat by the alternative use of inspiratory vital capacity and FEV1/FVC. Transfer factor did not contribute additional information; however, inclusion of VE materially improved the accuracy (SEE, 12.9%; r2, 44%). Among a subgroup of 35 men whose lung disease was due to asbestos, %TL' or transfer factor measured using a multibreath estimate of residual volume (%TLCO) made a small contribution to the explained variance, e.g.: %VO2max = 0.44% FEV1 -0.78 VE + 0.16% TLCO + 52.3 SEE 7.27%. This equation also described the %VO2max of all subjects (SEE, 13%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Nonmalignant pleural disease in asbestos exposed workers].

The review deals with nonmalignant pleural changes related to asbestos: pleural thickenings, calcifications and effusions. The pathology of the pleural changes and their prevalence in asbestos exposed populations is described. The report presents also the ILO radiographic criteria for identification and classification of pleural changes and the correlation of X-ray findings to autopsy ones. The function of the lung in workers with the pleural disease is analyzed in terms of specific respiratory defects such as restriction of lung size and transfer defect. Finally the implication of the diagnosis of nonmalignant pleural disease for clinical practice is discussed with a special regarded to asbestos related occupational lung disease.

Asbestos↗