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J Tocilj

Publications and source records attributed to J Tocilj.

33 records · Page 2Linked to original sources
PubMed1991

Perfect-mixer retention function by analytical deconvolution of tracer histograms: application to evaluation of left-ventricular contractility and competence.

The analytical solution for the perfect-mixer retention function, r(t), was developed from tracer histograms sampled at the system input, i(t), and its output, y(t), linked by the convolution integral y = i * r. Theories were developed for both continuous-output mixer and pulsatile, discrete mixer. The latter method was applied in first-pass radioangiography (FPRA) to calculate the forward ejection fraction of the left ventricle (LVFEF). Curves generated over the lungs and the ventricle provided system input and output respectively. LVFEF correlated strongly with the reference values obtained with simultaneously acquired gated FPRA(LVGEF) in 32 non-regurgitant patients: LVGEF = 0.90LVFEF + 5.93, r = 0.96, SEE = 3.98, p less than 0.001. In 14 patients with left-side valvular incompetence LVFEF values (0.41 +/- 0.13) were consistently lower than the corresponding LVGEF values (0.63 +/- 0.11). The method is free from instability inherent in numerical deconvolution. Applied in FPRA it yielded accurate estimates of LV contractility and competence. The continuous-mixer theory may apply to arbitrary compartmental models studied via tracer kinetics.

Adolescent↗
PubMed1991

Early detection of interstitial lung disease in asbestos exposed non-smoking workers by mid-expiratory flow rate and high resolution computed tomography.

Ten years of lung function and radiological findings in six non-smoking asbestos exposed subjects who had increased mid-expiratory flow rate (FEF 25-75%) as the only functional abnormality were prospectively analysed. A biphasic change in FEF25-75% was noted. It initially increased up to the fifth year, and then a decrease was seen. In the final three years of the study, FEF25-75% reduction correlated well with a decrease in pulmonary capacity for CO (DLCO). During that time high resolution computed tomography (HRCT) probability scores correlated inversely with FEF25-75% and with DLCO, whereas chest radiography was unchanged (International Labour Organisation (ILO) profusion below 1/1). For five of the six subjects HRCT probability of asbestosis was intermediate. An increase in FEF25-75% in some asbestos exposed non-smoking workers may be one of the earliest functional signs indicative of future development of parenchymal asbestosis. Early asbestos related parenchymal abnormalities are seen more frequently on HRCT than on chest radiography.

Adult↗
PubMed1991

Effects of nifedipine on diffusing capacity and pulmonary capillary blood volume in chronic obstructive pulmonary disease. A controlled study.

The acute dose-dependent effects of nifedipine on the pulmonary diffusing capacity for CO and other lung function indices were investigated in patients with chronic obstructive pulmonary disease (COPD) in a randomized double-blind, cross-over, placebo-controlled trial. Seventeen successive, clinically stable, moderate COPD patients with pulmonary hypertension and 15 control subjects were included in the study. The diffusing capacity of the lungs for carbon monoxide (DLCO) was measured with the single-breath method. Nifedipine (10 and 20 mg) and placebo were administered sublingually at room air. Nifedipine (10 and 20 mg) increased DLCO and DLCO/alveolar volume; however, a larger effect was observed with 10 mg. In addition, nifedipine increased the pulmonary capillary blood volume dose-dependently while arterial oxygenation was improved only with 10 mg nifedipine. Venous shunt was significantly increased with 20 mg nifedipine whereas spirometric parameters were unaffected. The percent DLCO change with 10 or 20 mg nifedipine was inversely correlated with baseline DLCO, but not with the severity of obstruction. Nifedipine did not have any effect in the control group, except for mild hypotension and a reflex increase in the heart rate. It is concluded that 10 mg nifedipine probably has an effect on the pulmonary circulation in moderate COPD patients with pulmonary hypertension.

Adult↗
PubMed1991

Effects of hemodialysis and anemia on pulmonary diffusing capacity, membrane diffusing capacity and capillary blood volume in uremic patients.

The study aimed at investigating pulmonary function in uremic patients, emphasizing the lung diffusing capacity for CO (DLCO) and its membrane and pulmonary capillary blood volume (Vc) components. The study sample comprised 25 uremic patients without clinical/radiological evidence of lung disease. They were enrolled in a chronic hemodialysis (HD) program and had anemia requiring transfusions. The subjects were tested for their lung function before and after both a first HD and a HD with blood transfusion (BT) that followed a few days later. After HD-induced removal of body fluid, and increase in pre-HD reduced forced vital capacity, alveolar volume and mid-expiratory flow rate (FEF25-75%) was observed. HD-induced DLCO decrease (p less than 0.005) was observed and was related to decreased Vc. The second HD with BT increased DLCO, due to partially normalized Hb. On average, a 7.2% DLCO increase corresponded to each 10-g/l Hb rise. In conclusion, (1) the beneficial effect of HD in uremic patients reverts the small-airway obstruction; (2) the lower values of DLCO in these patients are due to reduced Hb and HD causes further DLCO reduction via decrease of Vc, and (3) HD with BT still increases DLCO because improvement of Hb predominates.

Adult↗
PubMedDate not supplied

Correlation between radiological and functional findings in workers exposed to chrysotile asbestos.

The relationship between the extent of respiratory disease from chest radiographs and the severity of functional impairment was assessed in 185 workers with long-term exposure to asbestos in an asbestos-cement factory. The workers were divided into seven subgroups according to functional abnormality findings (restrictive, obstructive, mixed restrictive-obstructive, reduced diffusion capacity, increased diffusion capacity, small airway disease and normal). Restrictive functional abnormality was present in 29% of the workers, obstructive and mixed in 3% small airway disease in 4%, reduced diffusion capacity in 4% increased diffusion capacity in 7%, while the remaining 49% were normal. The subjects with radiological diffuse pleural disease were characterized by FVC reduction, whereas in those with mixed pleural-parenchymal radiological abnormalities both FVC and DLCO were reduced. FVC and DLCO decrements correlated well with the increasing grades of profusion according to the ILO classification. In the group of workers with normal chest radiographs and normal spirometry, a decrease or increase in lung diffusion capacity for CO (DLCO) was an isolated finding. In addition, a correlation existed between the length of exposure and functional parameters (reduced FVC and DLCO, while FEV1/FVC increased with longer exposure). The study shows that reduced lung function indices can be found in subjects without radiological evidence for parenchymal asbestosis (ILO grade 1/1 profusion or greater). The results suggest that asbestos exposure, in addition to lung diffusion capacity decrease, can be accompanied by an increase in lung diffusion capacity.

Adult↗
PubMedDate not supplied

[Determination of blood volume in pulmonary capillaries in patients with chronic obstructive lung disease].

The subjects were divided into four groups, three of which consisted of patients with various degrees of lung obstruction, while the fourth was the control group. The patients were divided according to the spirometric values: VC, FEV1, FEV1/VC%. The diffusing capacity was determined on the basis of the single breath method and graphical separation of the diffusion components was performed. It was found that the diffusing lung capacity was slightly lower in patients with mild to severe obstructive lung disease. The capillary blood volume was also slightly lower. Correlations between the degree of obstruction of the respiratory system and the diffusing lung capacity or the lung capillary blood volume was not statistically significant (p greater than 0.5). In studying patients with obstructive lung disease we were unable to establish which of the diffusion components significantly affected the value of the total diffusing lung capacity.

Adult↗
PubMedDate not supplied

[Functional and radiologic changes in workers in the asbestos-cement industry].

The influence of asbestos fibers on the radiologic and functional parameters in workers from the asbestos-cement factory was analyzed. 202 workers were examined each year for the last three years, while some of the workers were followed up to the last 10 years. It was found that the lung damage due to asbestos exposure is expressed highly individually. Some examinees had abnormal chest x-ray and normal lung function, some had abnormal function and normal x-ray, while only in advanced cases we found both radiologic and functional abnormalities. In addition to previously described lung function abnormalities, the authors found that some examinees had an increase in diffusing capacity in the early phase of asbestosis. The importance of dynamic lung functional measurements in workers exposed to asbestos is discussed.

Adult↗
PubMedDate not supplied

[The effect of physical exercise on lung diffusing capacity in patients with chronic obstructive lung disease].

Diffusing lung capacity (DLCO) was determined at various levels of exercise in three groups of subjects: group with normal spirometry, patients with moderate and severe chronic obstructive pulmonary disease (COPD). Subjects were males with similar anthropometric characteristics and age. Positive correlation between progressive exercise and DLCO was obtained only for the first and second group. Resting and exercise DLCO values were statistically different between the groups. COPD attenuated DLCO at all levels of exercise. However, patients with moderate COPD had DLCO in the normal range, while severe COPD patients had reduction in DLCO during rest and exercise. This test is useful in assessing the working capacity in COPD patients and also as a screening test for exercise-induced hypoxemia.

Adult↗
PubMedDate not supplied

[The acute effect of nifedipine in chronic obstructive lung disease].

Acute effects of calcium channel blocker nifedipine were investigated in patients with chronic obstructive pulmonary disease (COPD. In the present study 10 patients were included in the early phase of COPD and 20 patients in the late phase with chronic respiratory insufficiency characterized with resting hypoxemia, hypercapnia and respiratory acidosis. The patients were examined before and after sublingual application of nifedipine (10 mg) or placebo in single-blind study design. Nifedipine did not alter spirometric parameters (FVC, FEV1, FEV1/FVC), except in the late phase of COPD (FEV1). However, acute nifedipine treatment significantly improved resting arterial blood gases: PaO2 increased in both groups while PaCO2 decreased only in the patients in advanced phase of COPD. Additionally, nifedipine increased DLCOSB in the early phase of COPD. Acute nifedipine was found to have a beneficial effect in COPD patients.

Humans↗
PubMedDate not supplied

[The effect of hemoglobin levels in the blood in pulmonary diffusing capacity].

Using a "single breath" method, diffusing lung capacity (DLCO) and unit DLCO (KCO) were measured in 19 patients with chronic sideropenic anemia and 19 healthy women who were without any clinical or radiologic evidence suggestive of cardiorespiratory disease. Anemic patients, compared to the control group, had significantly reduced DLCO (% predicted) and KCO (% predicted) (p < 0.01). Each 10 g/L hemoglobin (Hb) reduction below a normal value of 136 g/L corresponded to 2% DLCO% and 3% KCO% reductions. For all examinees, where the range of Hb was from 50 to 150 g/L, a significant positive low linear correlation was noted between DLCO% and HB (r = 0.31; p = 0.049) and KCO% and Hb (r = 0.43; p = 0.005). Analyzing only anemic patients, where the range of Hb was from 50 to 109 g/L, no significant correlation was found between Hb and DLCO% or KCO%. Therefore, in patients with chronic sideropenic anemia DLCO is lowered less then expected, so one should not adjust measured DLCO or KCO values to standard Hb concentration, because probably various pathophysiological compensatory mechanisms affect DLCO components in unknown manner, changing the relationship between Hb and DLCO.

Adult↗
PubMedDate not supplied

[Pulmonary function after decortication of the lung].

From 1985 to 1994 decortication of the lung was performed in 60 patients. The indications were: specific and non-specific empyema, chronic pleural effusion, chronic pneumothorax and hemothorax. To assess the lung function, the measurements of vital capacity, forced expiratory volume and maximum breathing capacity, as well as blood gas analysis were performed preoperatively and six months after the operation. The slight improvement of lung function was seen postoperatively. Usual postoperative complications were successfully treated. Indications for decortication for the purpose of improving the lung function remain questionable.

Adult↗