Biomedical subjects

H Zwick

Publications and source records attributed to H Zwick.

At least 37 records · Page 2Linked to original sources

PubMed1996

Defective endogenous opioid response to exercise in type I diabetic patients.

Plasma beta-endorphin (beta-E) concentration was determined before, during, and after a standardized incremental exercise test to maximal capacity in eight type I diabetic patients and eight normal control subjects. Diabetic patients were studied under normoglycemic and hyperglycemic conditions in a single-blind random fashion to differentiate between the effects of acute hyperglycemia and of diabetes per se on the beta-E response to exercise. The perceived magnitude of leg effort elicited by exercise was evaluated using a category scale. Whereas plasma beta-E concentrations increased in control subjects with increasing workload, causing significantly higher beta-E levels at the end of exercise than at the beginning (P < .001), no such increase could be observed in the diabetic patients under normoglycemic and hyperglycemic conditions. In addition, baseline plasma beta-E concentrations were significantly lower in normoglycemic (P < .01) and hyperglycemic (P < .001) diabetic patients than in control subjects. Even during the recovery period, patients' beta-E levels remained significantly lower than those of control subjects. At submaximal levels of power output, the perceived intensity of leg effort was significantly higher in normoglycemic and hyperglycemic diabetic patients than in control subjects. We conclude that in type I diabetic patients, the ability of the endogenous opioid system to respond to exercise-induced stress is impaired under hyperglycemic and even under normoglycemic conditions. Considering the effect of endogenous opioids on stress tolerance, such changes may compromise exercise performance in diabetic patients.

Adult↗

PubMed1996

Evaluation of Cyfra 21-1 as a marker for lung cancer.

The sensitivity and specificity of Cyfra 21-1 as marker for lung cancer was evaluated in comparison with carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC) and neuron-specific enolase (NSE). Patients with histologically verified lung cancer and different groups without lung cancer were investigated. Sensitivity of Cyfra 21-1 (cut-off level 2.9 micrograms/l) was 40% for non-small cell lung cancer (NSCLC), 60% for rare histological types and 21% for small cell lung cancer (SCLC). In NSCLC sensitivity of Cyfra 21-1 was 35% for squamous cell carcinoma and 41% for adenomous carcinoma. The highest sensitivity for CEA was 45% in NSCLC, with 57% in the subtype of adenomous cell carcinoma; for SCC 30% was achieved in squamous cell carcinoma and for NSE 66% sensitivity was reached in SCLC. In our patients Cyfra 21-1 and CEA appeared equally useful for evaluating patients with NSCLC.

Adult↗

PubMed1995

Nasal continuous positive airway pressure for nonapneic snoring?

The feasibility of nasal continuous positive airway pressure (CPAP) for heavy snoring associated with daytime sleepiness was studied in 118 consecutive patients with an apnea hypopnea index below 5. Fifty-nine of them reported daytime sleepiness in a questionnaire and were offered treatment with nasal CPAP. Whereas 48 patients refused it, the remaining 11 (19%) accepted nasal CPAP for home therapy. Acceptors and refusers did not differ in sleep structure, but acceptors had slightly more sleep-disordered breathing events per hour of sleep than refusers. The pressure needed to abolish snoring in these 11 patients was 7.3 +/- 1.6 cm H2O. Six months after prescription, the built-in time counters of the patients' devices were read. By dividing the hours of operation by the days since initiation of treatment, we found a mean daily use time of only 2.8 +/- 1.5 h. Nevertheless, eight patients (73%) reported that their sleepiness had improved with therapy. We conclude that only a minority of nonapneic snorers accept treatment with nasal CPAP on a long-term basis and that this subgroup is not predictable from polysomnography.

Female↗

PubMed1995

Nasal function and bronchial hyperresponsiveness to methacholine in children.

The objective of the present study was to investigate nasal function by active anterior rhinomanometry with respect to spirometric data and bronchial hyperresponsiveness to methacholine in 9-year-old children. The study population consisted of 300 children (ages 8 to 11 years; mean, 9.3 years; 161 male, 139 female), who underwent basal rhinomanometry followed by a decongestion test and a lung function test consisting of spirometry and a methacholine provocation test. The flow values of the basal rhinomanometry showed a significant correlation with height and bronchial hyperresponsiveness. The consecutive decongestion test showed a marked increase in flow rates at each level, which was found to be significantly higher in children with bronchial hyperresponsiveness (p < 0.01). The spirometric data showed no influence on rhinomanometric values. These results suggest that nasal dysfunction and reactivity in terms of the decongestion test may be associated with bronchial hyperresponsiveness in children.

Airway Resistance↗

PubMed1995

Effect of autonomic neuropathy on ventilatory response to progressive hypercapnia in dialysis patients.

The impact of autonomic neuropathy (common in patients on haemodialysis) on ventilatory response to hypercapnia has been studied. We investigated cardiac reflex tests in 20 patients on chronic haemodialysis (8 patients were found with and 12 without neuropathy of the autonomic nervous system). Using the hyperoxic CO2-rebreathing method (according to Read), we tested the above-mentioned two groups of patients and compared them with 14 healthy control subjects. Accumulation of CO2 in blood with hyperoxic CO2 rebreathing stimulates central chemoreceptors, and therefore causes a progressive rise in minute ventilation. In patients with autonomic neuropathy (n = 8), ventilatory response to increasing pCO2 was significantly lower than that in the controls (1.7 +/- 0.3 versus 3.2 +/- 0.5 l/min/mmHg, P < 0.001). On the other hand ventilatory response in patients without autonomic damage (n = 12) showed no significant difference when compared to controls (3.1 +/- 0.8 l/min/mmHg). There were no differences in lung function, arterial blood gas analysis, blood chemistry, duration on dialysis, and demographic data when comparing the patients with and those without autonomic damage. Our analysis shows different patterns of ventilatory response to increasing pCO2 in patients on haemodialysis. Autonomic neuropathy has to be considered when rebreathing tests are interpreted. The clinical relevance of these findings needs further investigation.

Analysis of Variance↗

PubMed1995

[Sensitization to inhaled allergens in the Vienna population].

The present study investigated the sensitization to inhalatory allergens in a randomized cross-section of the population of Vienna (altogether 3000 men and women). A representative sample of 600 persons was invited to an examination consisting of a skin prick test and determination of serum total IgE and allergen-specific IgE. In addition, the same tests were performed in persons with asthma or allergic rhinitis on the basis of a history of these conditions in the replies to a screening questionnaire. Our results showed comparatively high sensitization rates to grass pollen (28%), house dust mite (25%) and cat dander (20%) in the randomized group A. In the symptom-free "healthy" subgroup of the randomized population sample (Group B) there were remarkably high sensitization rates to house dust mite (21%), grass pollen (17%) and cat dander (12%). For the group with allergic rhinitis (Group D) sensitization to grass pollen exceeded 60%, followed by cat dander (44%), birch pollen (36%) and house dust mite (35%). In the asthmatic persons (Group C) the leading allergens were cat dander (40%) and the house dust mite (37%), followed by grass pollen (33%) and birch pollen (20%). Regarding the overall sensitization to inhalatory allergens 61% of the asthmatic group showed a positive prick test. Increased serum levels of total IgE or specific IgE were found in 76% of cases, which underlines the allergic origin of this disease. In the randomized group 51% were sensitized to inhalatory allergens, whilst 39% were subclinically sensitized without ever having had any allergic complaints.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Diaphragmatic function in patients on continuous ambulatory peritoneal dialysis.

We investigated 8 patients undergoing continuous ambulatory peritoneal dialysis (CAPD) for diaphragmatic strength and the neuromechanical efficiency of the diaphragm while the abdomen was filled with dialysate and while it was empty. Maximum transdiaphragmatic pressure (Pdimax) served as parameter for diaphragmatic strength; diaphragmatic efficiency was assessed by simultaneously monitoring transdiaphragmatic pressure (Pdi) and diaphragmatic electromyogram (EMGdi) during room-air breathing and hyperoxic CO2-rebreathing. After instilling dialysate, Pdimax increased from 76.7 +/- 12.1 cmH2O to 92.2 +/- 16.3 cmH2O (P < 0.05). While the slopes of the regression lines relating minute ventilation (VE) to arterial CO2 tension, and the change in VE for a given change in Pdi during hypercapnic rebreathing were similar in both states, the slope of EMGdi vs Pdi was significantly steeper when the abdomen was filled (P < 0.05). The increase in Pdimax observed in the filled state may suggest an adaptive rightward shift in the diaphragm's force-length relationship in CAPD patients, although this mechanism is insufficient to prevent a reduction of neuromechanical efficiency of the diaphragm.

Adult↗

PubMed1994

Factors contributing to the occurrence and predictability of bronchial hyperresponsiveness to methacholine in children.

Using a stepwise logistic regression analysis, we investigated clinical data, allergologic findings, spirometric data, and the cellular and humoral immune system in order to gain new insights into the role these parameters play in bronchial hyperresponsiveness to methacholine in children and to create a model for the prediction thereof. Bronchial hyperresponsiveness, which was found in 124 of 462 children (26.8%), was observed to have been influenced by an increased level of eosinophils, the positivity of the skin prick test for any of the allergens tested, a decreased baseline forced expiratory volume in 1 second (FEV1) (percent predicted), a decreased maximum expiratory flow at 50% expiration as a percent of forced vital capacity, and a decreased level of kappa-chain-assembled immunoglobulins. Logit analysis disclosed that the influence of all other parameters on the occurrence of bronchial hyperresponsiveness was of no further statistical significance. The degree of bronchial hyperresponsiveness (provocative dose causing a 20% fall in FEV1) showed a statistically significant correlation with the eosinophil count (Spearman's r = -0.198) and FEV1 (percent predicted) (Spearman's r= 0.203). Our findings suggest that allergic sensitization and eosinophilic reaction in children are major factors in contributing to the occurrence of bronchial hyperresponsiveness to methacholine.

Allergens↗

PubMed1994

Prediction of sensitization to flour allergens.

The purpose of the present study was to investigate the factors that may contribute to the sensitization to flour in baker's apprentices, and to predict this type of sensitization with a stepwise logistic regression model. Of the total of 258 baker's apprentices, 54 (20.9%) exhibited specific IgE development against flour allergens (wheat, rye, and/or barley). Allergologic variables, such as the total IgE level and IgE specific to grass pollen, tree pollen, weed pollen, molds, and animal dander, were found to correlate strongly with the sensitization to flour. However, the correlation between the presence of other manifest allergies and the sensitization to flour was weak. The presence of shadowing of the paranasal sinuses on the radiograph (mucosal thickening, opacity, air/fluid levels, and/or polypous shadowing) correlated with flour sensitization as well as with the leukocyte and lymphocyte counts in peripheral blood. Of the lung function data, only total lung capacity (in percentage of the predicted values) weakly correlated with the sensitization to flour. We were able to predict flour sensitization with a sensitivity of 63%, a specificity of 90%, and an efficiency of 84% by using the parameters that allow for the presence or absence of IgE specific to grass pollen and tree pollen, the presence or absence of radiographic shadowing, and total lung capacity in percentage of the predicted values.

Allergens↗

PubMed1994

Effect of lung transplantation on diaphragmatic function in patients with chronic obstructive pulmonary disease.

BACKGROUND: To date there are no data on the effects of lung transplantation on diaphragmatic function in patients with end stage chronic obstructive pulmonary disease (COPD). It is not known whether the relation between the transdiaphragmatic pressure (PDI) and lung volume is altered in recipients after transplantation as a result of changes in diaphragmatic structure caused by chronic hyperinflation. The effect of lung transplantation on diaphragmatic strength was determined in patients with COPD and the relation between postoperative PDI and lung volume analysed. METHODS: Diaphragmatic strength was assessed in eight double lung transplant recipients, six single lung transplant recipients, and in 14 patients with COPD whose lung function was similar to those of the transplant recipients preoperatively. PDI obtained during unilateral and bilateral phrenic nerve stimulation at 1 Hz (twitch PDI) at functional residual capacity (FRC) and during maximal sniff manoeuvres (sniff PDI) at various levels of inspiratory vital capacity (VCin) served as parameters for diaphragmatic strength. Sniff PDI assessed at the various VCin levels were used to analyse the PDI/lung volume relation. RESULTS: Lung transplantation caused a reduction in lung volume, especially in the double lung transplant recipients. As a consequence sniff PDI was higher in the double lung transplant recipients than in the patients with COPD at all levels of VCin analysed. However, sniff PDI values analysed at comparable intrathoracic gas volumes were not reduced in the patients with COPD when compared with those who underwent lung transplantation. Bilateral twitch PDI values were similar in the patients with COPD and in the lung transplant recipients. In the single lung transplant recipients unilateral twitch PDI values were similar on the transplanted and the non-transplanted side. The relation between PDI and lung volume was similar in the patients with COPD and in the lung transplant recipients. CONCLUSIONS: In patients with COPD lung transplantation leads to an increase the maximal sniff induced PDI values by placing the diaphragm in a more favourable position for pressure generation. Since patients with COPD and postoperative lung transplant recipients showed similar PDI/lung volume relations, this suggests that chronic pulmonary hyperinflation does not cause major functional alterations of the diaphragm.

Adult↗

PubMed1994

Effects of the sauna on diffusing capacity, pulmonary function and cardiac output in healthy subjects.

The present study examined possible short-term effects of the heat stress during sauna bathing on gas exchange, especially in correlation with changes in cardiac output. The results obtained are as follows: (1) The heat stress of sauna bathing caused a slight but not significant increase in diffusion capacity (p = 0.239) and no change in other pulmonary function parameters. (2) Cardiac output and cardiac index increased slightly but not significantly (p = 0.2455 and p = 0.2719). We conclude that heat stress in sauna neither influences gas exchange nor does it cause a significant increase in cardiac output.

Adolescent↗

PubMed1994

Chest X-ray in collagen vascular diseases. A comparison of chest X-ray with bronchoalveolar lavage and transbronchial forceps biopsy.

The diagnostic value of chest X-ray following the ILO standards was compared with bronchoalveolar lavage (BAL) and the histology of transbronchial forceps biopsy in 83 patients with collagen vascular diseases. BAL in the middle lobe was considered abnormal in case of increased cell count per milliliter and/or lymphocytosis and/or neutrophil granulocytosis and this was found in 32 out of 42 cases (76.2%) with, and in 33 of out 41 cases (80.5%) without abnormal radiological finding. Pathological changes in the histology were found in 14 out of 20 cases (70.0%) with and in 40 out of 63 cases (63.5%) without abnormal chest X-ray in the upper lobe from which the transbronchial forceps biopsy specimens were obtained. In histological specimens obtained from transbronchial forceps biopsy, only fibrosis correlated with abnormal radiological findings in this region. Other inflammatory processes defied prediction by chest X-ray. This suggests that, regardless of chest X-ray findings, BAL should be performed together with transbronchial forceps biopsy for the histological examination of patients with collagen vascular diseases in which interstitial lung involvement is suspected.

Adolescent↗

PubMed1994

The effect of aminophylline on the force-length characteristics of the diaphragm.

The aim of our study was to evaluate the effect of aminophylline on the contractile function of the human diaphragm during varying muscle fiber length. Ten healthy subjects were studied during maximal sniff maneuvers and bilateral phrenic nerve twitch stimulations, with and without intravenous infusion of aminophylline in a randomized fashion. The transdiaphragmatic pressures generated at various baseline lung volumes, from residual volume to 90% of total lung capacity, were recorded before and after the induction of diaphragm exhaustion. At all levels of lung volume, aminophylline did not have an effect on the contractility of the fresh diaphragm. In the exhausted diaphragm, however, the pressure values, induced by sniffs and twitch stimulations, were significantly improved by aminophylline. This positive effect on diaphragm contractility was also impressive at 60, 75, and 90% of total lung capacity. This indicates that aminophylline significantly improves the contractile function of the exhausted human diaphragm, even if the muscle fibers are shorter than optimal. This effect occurs regardless of the neuronal firing rate, whether it is low (twitch stimulation) or high (sniff maneuver).

Adult↗

PubMed1994

Effects of combined inspiratory muscle and cycle ergometer training on exercise performance in patients with COPD.

Cycle ergometer training plays an important role in the rehabilitation of patients with chronic obstructive pulmonary disease (COPD), but the usefulness of specific inspiratory muscle training as part of pulmonary rehabilitation remains uncertain. To determine whether inspiratory muscle training could intensify the known beneficial effects of cycle ergometer training on exercise performance in these patients, we compared the effect of an 8 week inspiratory muscle training combined with cycle ergometer training with that of an 8 week cycle ergometer training alone on inspiratory muscle performance and general exercise capacity. Patients were randomly assigned to the two training groups; 21 patients received additional inspiratory muscle training (Group 1) and 21 did not (Group 2). Maximal sniff assessed oesophageal and transdiaphragmatic pressures served as parameters for global inspiratory muscle strength and diaphragmatic strength, respectively. The duration for which the patient could breathe against a constant inspiratory pressure load was used as an index of inspiratory muscle endurance. Exercise capacity was determined by an incremental symptom-limited cycle ergometer test. After the training period, inspiratory muscle performance improved significantly in the patients with inspiratory muscle training, but not in those without. Both training regimens increased maximal power output and oxygen uptake, but this improvement was significantly greater in the patients with inspiratory muscle training than in those without.(ABSTRACT TRUNCATED AT 250 WORDS)

Breathing Exercises↗

PubMed1994

Inspiratory muscle training in patients with Duchenne muscular dystrophy.

PURPOSE: The aim of this study was to assess the usefulness of a specific inspiratory muscle training in Duchenne muscular dystrophy (DMD). PATIENTS AND METHODS: Fifteen patients with DMD started 6 months of training the inspiratory muscles and 15 patients served as a control group. Pulmonary and inspiratory muscle function parameters were assessed 3 months before and at the beginning of training, in the first and third month of training, at the end, and 6 months after its cessation. Maximal sniff assessed esophageal and transdiaphragmatic pressure values served as indices for global inspiratory muscle strength and diaphragmatic strength, respectively. Inspiratory muscle endurance was assessed by the length of time a certain inspiratory task could be maintained. RESULTS: In 10 of the 15 patients, respiratory muscle function parameters improved significantly after 1 month of training. Further improvements were to be seen after 3 and after 6 months. Even 6 months after the end of training, those effects remained to a large extent. In the other five patients, there was no such improvement after 1 month of training, which was therefore discontinued. All these five patients had vital capacity values of less than 25 percent predicted and/or PaCO2 values of more than 45 mm Hg. The 15 control patients had no significant change in their respiratory muscle function parameters. CONCLUSION: We conclude that a specific inspiratory muscle training is useful in the early stage of DMD.

Adolescent↗

PubMed1993

Bronchoalveolar lavage in rheumatoid arthritis.

Bronchoalveolar lavage (BAL) was performed on 70 RA patients, 28 without extra-articular manifestations, nine with pulmonary involvement, 13 with sicca-syndrome, 20 with other extra-articular manifestations such as renal involvement, cutaneous vasculitis and rheumatoid nodules. Fifteen patients without rheumatic or pulmonary disease served as the control group. Compared with the control group RA patients showed a statistically significant increase of lymphocytes, especially of activated (DR+)T(CD3+)-helper (CD4+) cells, resulting in a significantly diminished percentage of alveolar macrophages, B(CD21+)-lymphocytes, T-suppressor (CD8+) cells and an increased CD4/CD8 ratio. This cell distribution pattern was more pronounced in RA patients with lung involvement with significant differences to the other RA patients with regard to lymphocytes, DR positive cells and CD4 positive/DR positive cells. It is concluded that these results indicate an altered balance of immunocompetent cells not only in the joints but also in the lung. The changes are more distinct if local manifestations can be diagnosed clinically.

Aged↗

PubMed1993

The effect of opioids on inspiratory muscle fatigue during inspiratory resistive loading.

The effect of opioids on inspiratory muscle function under high mechanical load is still unknown. Even less clear is the extent to which opioids influence the shift of the electromyographic power spectrum of the inspiratory muscles to lower frequencies during ventilatory stress. We studied seven healthy subjects breathing against high inspiratory threshold loads until exhaustion while keeping the minute ventilation constantly high. We compared runs with and without administration of 0.2 mg kg-1 of morphine sulphate intramuscularly; two subjects were given 30 mg morphine sulphate so that we could study the effect of higher opioid concentration. The endurance time (Tlim), the diaphragmatic electromyogram (EMG), the transdiaphragmatic pressures (Pdi) and the ventilatory effort sensation were analysed. Morphine did not have any effect on Tlim or on the effort sensation elicited by the inspiratory resistance in both concentrations. Analysing the spectral shifts of the diaphragmatic EMG, we did not find any significant difference in the decrease of the centroid frequency between drug and control runs. Furthermore, the activation pattern of the diaphragm and the intercostal muscles, evaluated from the percentage contribution of oesophageal and gastric pressures on the transdiaphragmatic pressure swings, did not change following the administration of morphine. Our study shows that morphine does not change the function of the inspiratory muscles during high-resistive breathing. Morphine does not affect the electromyographic power spectrum of the diaphragm during those resistive breathing runs, either. This points out that during stressful ventilatory situations, the shift of the electromyographic power spectrum is attributed to a peripheral (muscular) event consequent to muscle fatigue and not to the elaboration of endogenous opioids.

Adult↗

PubMed1993

Model for investigating snorers with suspected sleep apnoea.

BACKGROUND: Overnight polysomnography is expensive and time consuming. An approach based on a logistic regression model and overnight pulse oximetry has been developed to determine which of the snorers referred to our sleep laboratory need polysomnography. METHODS: The variables entered in the regression model were derived from questionnaires completed by 95 habitual snorers and 89 patients with obstructive sleep apnoea. The resulting regression equation included weight, height, sex, witnessed episodes of apnoea, and reports of falling asleep when reading. This prediction equation was applied to a sample of 116 consecutive patients referred for investigation of heavy snoring. Pulse oximetry data on the 116 test subjects were obtained during polysomnography and analysed separately. Pulse oximetry was judged to indicate obstructive sleep apnoea when it showed cyclic oscillations of oxyhaemoglobin saturation or heart rate, or both, for more than 30 minutes during the study night. RESULTS: A cut off probability of 0.31 gave the prediction model a sensitivity of 94% to predict an apnoea-hypopnoea index above 10, with a specificity of 45%. When this cutoff point was used to predict an apnoea-hypopnoea index of over 20 sensitivity was 95% and specificity 41%. Combined with oximetry our regression model had a sensitivity of 100% for predicting an apnoea-hypopnoea index of more than 10. On the other hand, all patients with negative results from oximetry and a probability value below 0.31 had an apnoea-hypopnoea index lower than 10 according to polysomnography. CONCLUSIONS: It is concluded that snorers with negative results from oximetry classified as not having obstructive sleep apnoea according to this model do not need polysomnography.

Adult↗