Biomedical subjects

W Popp

Publications and source records attributed to W Popp.

At least 37 records · Page 2Linked to original sources

PubMed1994

Concentrations of benzene in blood and S-phenylmercapturic and t,t-muconic acid in urine in car mechanics.

Different parameters of biological monitoring were applied to 26 benzene-exposed car mechanics. Twenty car mechanics worked in a work environment with probably high benzene exposures (exposed workers); six car mechanics primarily involved in work organization were classified as non-exposed. The maximum air benzene concentration at the work places of exposed mechanics was 13 mg/m3 (mean 2.6 mg/m3). Elevated benzene exposure was associated with job tasks involving work on fuel injections, petrol tanks, cylinder blocks, gasoline pipes, fuel filters, fuel pumps and valves. The mean blood benzene level in the exposed workers was 3.3 micrograms/l (range 0.7-13.6 micrograms/l). Phenol proved to be an inadequate monitoring parameter within the exposure ranges investigated. The muconic and S-phenylmercapturic acid concentrations in urine showed a marked increase during the work shift. Both also showed significant correlations with benzene concentrations in air or in blood. The best correlations between the benzene air level and the mercapturic and muconic acid concentrations in urine were found at the end of the work shift (phenylmercapturic acid concentration: r = 0.81, P < 0.0001; muconic acid concentration: r = 0.54, P < 0.05). In conclusion, the concentrations of benzene in blood and mercapturic and muconic acid in urine proved to be good parameters for monitoring benzene exposure at the workplace even at benzene air levels below the current exposure limits. Today working as a car mechanic seems to be one of the occupations typically associated with benzene exposure.

Acetylcysteine↗

PubMed1994

Genotoxic and cytotoxic effects of 4-aroyl-1-nitrosohydrazine-carboxamides on O6-alkylguanine-DNA alkyltransferase-positive and -negative human cell lines.

Five different representatives (I-V) of a new class of bifunctional alkylating agents, the 4-aroyl-1-nitrosohydrazinecarboxamides ("nitrososemicarbazides"), were evaluated for their potential interaction with DNA and for their cytotoxic activity in vitro to O6-alkylguanine-DNA alkyltransferase-positive (Mer+) and -negative (Mer-) human cell lines. The HeLa MR cell line (Mer-) showed up to 20-fold higher sensitivity at IC50 (dose that inhibits colony formation by 50%) to agents I-V than did the HeLa S3 cell line (Mer+) in a colony-formation assay. These data were compared to those obtained by treatment of the two cell lines with carmustine, a currently used antitumor drug. In Mer+ cells comparable results to those with carmustine were obtained with compounds III, IV and V; in Mer- cells compounds I and II showed nearly the same effects as carmustine. Whether compounds I-V produce DNA strand breaks and/or DNA-protein cross-links was investigated using an alkaline filter elution technique. In this assay all compounds produced DNA single-strand breaks; no correlation could be detected between the strand breakage frequency and cytostatic, mutagenic and antitumor activity.

Carmustine↗

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

Sister chromatid exchange frequencies in lymphocytes of oral cancer patients seem to be influenced by drinking habits.

Sister chromatid exchange (SCE) values were determined in the lymphocytes of 24 oral cancer patients before therapy and in the lymphocytes of 24 control persons standardized with respect to sex, age and smoking habits. Oral cancer patients showed significantly elevated SCE values (mean 7.82 versus 6.42). In both groups the highest SCE values were found in the subgroups with the highest alcohol consumption. A significant correlation between SCE and gamma-glutamyltranspeptidase (GGT) values by Spearman correlation analysis was detected in the combined group (cancer patients and control persons) (n = 32, r = 0.40, P = 0.023). The SCE values in the oral cancer patients were weakly correlated (Pearson) to DNA adduct levels (n = 22, r = 0.39, P = 0.068) and DNA single-strand breakage frequencies (n = 12, r = 0.56, P = 0.054) in lymphocytes. The correlation (Pearson) between SCE values and DNA strand breakage values in lymphocytes was significant (n = 10, r = 0.67, P = 0.036) in smoking cancer patients. The increase of SCE values with respect to alcohol drinking habits underlines epidemiologic findings that alcohol is an important co-carcinogen in many cancers, especially in oral cancers. Because of the influences on SCE and adduct levels in lymphocytes, alcohol drinking habits should be controlled as broadly as possible in biomarker studies.

Adult↗

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

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↗

PubMed1993

DNA strand breakage and DNA adducts in lymphocytes of oral cancer patients.

In lymphocytes of 12 oral cancer patients (and two control groups) the frequencies of DNA single-strand breaks and DNA-protein cross-linking were determined by alkaline filter elution. We found elevated DNA elution rates, which must be interpreted as an increased strand breakage frequency. There were significant correlations between the DNA strand breakage frequency and smoking habits. Using the 32P-postlabelling assay we determined the DNA adduct level in lymphocytes of 23 oral cancer patients (and two control groups). No significant influence of smoking habit on the DNA adduct level could be detected. There was a significant correlation between the DNA adduct level and the gamma-glutamyltranspeptidase (GGT) value, suggesting systemic influences of alcohol drinking habits on the adduct level.

Adult↗

PubMed1993

Studies on guanine adducts excreted in rat urine after benzene exposure.

Investigations with [14C]benzene indicate the formation of base adducts in vivo. Experiments to separate adducts from urine of [14C]benzene-exposed rats suggest the excretion of eight labeled compounds different from benzene metabolites. In order to obtain information about their structure we synthesized N7-, O6-, C8- and N2-phenylguanine. With regard to their chromatographic properties we compared these phenylguanines with products obtained by alkylation of guanine by metabolites of unlabeled and 14C-labeled benzene in vivo with HPLC with UV detection and liquid scintillation counting. Furthermore GC/MS and ELISA techniques were used to detect N7-phenylguanine. Phenylguanines could not be identified in collected DNA fractions. The labeled compounds detected in urine of [14C]benzene-exposed rats also showed deviations from the HPLC elution patterns of our reference substances. Even N7-phenylguanine, formerly suspected to be a urinary metabolite of benzene in the rat, could not be detected with these refined HPLC methods. With GC/MS a compound was found in trace amounts in concentrated rat urine samples, which had a similar fragmentation pattern to N7-phenylguanine. These data could not be confirmed by a sensitive immunological assay (ELISA). No N7-phenylguanine was detected in purified rat urine samples. The results suggest the excretion of a hydroxylated phenylguanine which may be formed in liver or bone marrow DNA by highly reactive hydroxylated intermediates. The OH group might be lost because of the high temperatures during GC/MS measurements. A hydroxy group at the phenyl-ring of N7-phenylguanine will cause other elution properties in HPLC compared to N7-phenylguanine.

Animals↗

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

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↗

PubMed1993

Nasal CPAP and weight loss in hypertensive patients with obstructive sleep apnoea.

BACKGROUND: The high prevalence of obstructive sleep apnoea (OSA) in patients with systemic hypertension and of hypertension in patients with OSA suggests a causal link between the two disorders. This study was carried out to determine whether nasal continuous positive airway pressure (CPAP) and weight loss affect daytime hypertension in OSA. METHODS: Sixty hypertensive patients with OSA took part in the study; 33 accepted nasal CPAP and used their machine for 5.7 (0.2) hours per night, and the remaining 27 patients refused nasal CPAP and upper airway surgery so the only therapeutic intervention was a recommendation of weight loss. A significant change in hypertension during follow up was defined as either a change in mean blood pressure of at least 10 mm Hg (or more than 8%) without a change in drug treatment, or a reduction in drug dosage with mean blood pressure within these limits. Weight loss was defined as a body mass index of at least 5% below the baseline value. RESULTS: After 512 (41) days, hypertension had become less severe in seven of 12 patients (58%) treated with weight loss only, in eight of 28 patients (29%) with nasal CPAP only, in two of five patients with nasal CPAP and weight loss, and in one of 15 patients without nasal CPAP or weight loss. Multivariate analysis of variance with the outcome of hypertension at follow up as the dependent variable revealed that only the percentage change in body mass index significantly contributed to the course of hypertension. CONCLUSION: The course of hypertension in OSA is more closely linked to weight loss than to elimination of sleep apnoea by nasal CPAP.

Body Mass Index↗

PubMed1993

Self-reported vs measured compliance with nasal CPAP for obstructive sleep apnea.

To estimate reliability of self-reported compliance with nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea (OSA), we studied 63 OSA patients aged 53.7 +/- 1.2 years (mean +/- SEM) with an apnea hypopnea index (AHI) of 50.8 +/- 2.9 and lowest sleep SaO2 of 65.6 +/- 2.3 percent receiving nasal CPAP for 539 +/- 44 days. During a follow-up polysomnography (PSG) on the pressure prescribed for home therapy (10.3 +/- 0.3 cm H2O), the hours of operation shown on the built-in time counter of the patients' devices were read to determine objective compliance by dividing the run time by the days since initiation of therapy. This parameter was compared with subjective compliance reported in a self-administered questionnaire. Mean measured use time was 4.9 +/- 0.3 h per night, whereas reported daily use time calculated from reported nights a week and hours a night was 6.1 +/- 0.3 h per night. As predominantly patients with poor compliance misestimated daily use time, we conclude that self-reports are unable to distinguish between compliant and noncompliant patients.

Female↗

PubMed1993

Lung involvement in rheumatoid factor-negative arthritis.

Bronchoalveolar lavage (BAL) was performed on 13 asymptomatic patients with sero (rheumatoid factor)-negative arthritis (SNA); (6 with peripheral psoriatic arthritis, 2 with axial psoriatic arthritis, 3 with ankylosing spondylitis, 2 with sacroiliitis). BAL revealed a significant decrease of neutrophil granulocytes and an increase of B-lymphocytes in patients with SNA in comparison with 64 patiénts with rheumatoid arthritis (RA; 24 seronegative, 39 seropositive) and 15 healthy controls. Patients with SNA and RA had a significant increase of lymphocytes, especially T, T-helper and activated cells. In addition patients with RA had a significant increase of natural killer cells and a lower percentage of alveolar macrophages and T-suppressor cells. Transbronchial biopsy was performed on 9 patients with SNA and on 59 patients with RA. Abnormal histologic features of lung tissue were observed in 4 out of 9 patients with SNA (2 with fibrosis, 1 with follicular lymphoid hyperplasia, 1 with desquamative interstitial pneumonitis). The abnormal lung histology in RA patients was more pronounced, however, the differences between SNA and RA were not significant. The data from BAL and histology suggest, that the pulmonary involvement in SNA and RA is caused by an unspecified immunologic process.

Adult↗

PubMed1993

Bronchoalveolar lavage and lung biopsy in rheumatoid arthritis. In vivo effects of disease modifying antirheumatic drugs.

Bronchoalveolar lavage (BAL) and histology of transbronchial forceps biopsy was performed in 59 patients with rheumatoid arthritis (RA) to evaluate the in vivo effects of disease modifying drugs (DMARD). All patients had no clinical pulmonary symptoms and there was no evidence of drug induced alveolitis. Patients were divided into 5 subgroups according to drug treatment: 9 patients taking chloroquine, 15 patients gold, 8 patients penicillamine, 8 patients methotrexate (MTX) and 19 patients not taking DMARD. Duration of DMARD regimen was more than 3 months. No patient was treated with corticosteroids. BAL results revealed an increased percentage of lymphocytes and a diminished proportion of alveolar macrophages in patients treated with gold, penicillamine, MTX and no DMARD. In contrast, patients receiving chloroquine had a normal distribution of lymphocytes and macrophages as seen in a control group of 15 persons. Patients taking MTX showed a normal distribution of T and B lymphocytes and DR positive cells, whereas patients receiving chloroquine, gold, or penicillamine had an elevated proportion of T lymphocytes and DR positive cells and a diminished percentage of B lymphocytes. The latter was also observed in patients not taking DMARD. The percentage of natural killer cells was significantly elevated only in the penicillamine group. Patients receiving gold had higher absolute values of CD3, CD4 and DR positive cells. Abnormal lung histology was associated with an increased percentage of lymphocytes and with higher DR positive cells in BAL. Patients not receiving DMARD had a significantly higher percentage (42.1%) of abnormal histologic features of lung tissue than patients receiving DMARD (17.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

Inspiratory muscle performance relative to the ventilatory threshold in healthy subjects.

Inspiratory muscle performance, ventilation, and gas exchange were studied during exercise in healthy subjects to look for typical changes of pattern of contraction at the ventilatory threshold (VT). The steepening of the slope of carbon dioxide output (VCO2) vs oxygen uptake (VO2) at the VT was accompanied by a nonlinear increase of the mean rate of esophageal pressure development (Pes/TI) vs the esophageal pressure time index (PTIes) reflecting both the relative force (Pbreath/Pesmax) and duration (TI/TTOT) required for inspiration. The esophageal pressure time integral within one breath (Pbreath.dTI) was one of the best single predictors of the ventilatory equivalent for oxygen (VE/VO2) at the VT. Moreover, we presented inspiratory muscle load indices as a mirror image of breathing pattern, with the obvious advantage that the ventilation component can be compared with better established methods of presenting ventilatory output. Inspiratory muscle performance during exercise should link the increased metabolic rate to ventilatory output. We conclude that 1) there exists an inspiratory muscle threshold that is well correlated to commonly used gas exchange thresholds, and 2) the efficiency of ventilation and gas exchange during exercise could be linked to pressure and timing of inspiratory muscle contraction.

Adolescent↗

PubMed1993

[Connection between air quality and room climate and estimation of dwellings by health-impaired inhabitants].

The investigation was performed in winter 1990 and 1991 when measurements were taken in 16 dwellings of patients, recruited from a pulmologic outpatient centre. Patients suffered from repeated respiratory irritations which they attributed to dwelling conditions. Inhabitants reported by means of questionnaires and standardized scales the dwelling situation and their dwelling behaviour, subjective ratings of indoor environmental quality as well as ratings of wellbeing. The load of indoor pollutants (CO2, CO, NO2, HCHO), biological agents (fungal spores, house dust mites) as well as indoor climate factors were assessed. The measurements revealed an evident load at least in one parameter; in the majority of dwellings combined loads of air pollutants and biological agents were apparent. Homes supplied with gas as main energy source had significantly higher concentrations of CO2, CO and NO2. At noon, exposure limits of CO2 and NO2 were frequently exceeded. Inhabitants of homes being supplied with electricity instead of gas gave significantly better air quality ratings. The correlations between the average score concerning the rated health quality of their homes and the rate of excess of exposure limits are significant: The health quality ratings are significantly related to the concentrations of "air quality indicators", which induce the feeling of stale air (CO2) and mucosa irritations (NO2). Ratings of wellbeing are significantly connected to objective parameters, i.e. NO2 baseline load, fungal spores in the air and the difference between wall-air temperature. Our study suggests that people suspecting a connection between their health impairment and dwelling conditions should be taken serious. The measurement program proved to be a suitable screening procedure to assess adverse environmental influences in homes. More homes should be investigated to further support our findings.

Air Pollution, Indoor↗

PubMed1993

[Polychlorinated biphenyls (PCBs) and reproduction disturbances].

A review of the impact of chlorinated biphenyls (PCBs) on reproduction is presented. PCBs are able to pass the placenta; accumulation in offspring is mainly achieved by breast feeding. Disturbances of fertility and embryotoxicity were detected in animals; teratogenicity without maternal toxicity was only observed in mice. In animal experiments disturbances of fetal and postnatal development were detected as well as in human studies. Neurotoxicity was observed even at low-level exposures in monkeys, which are most comparable to humans because of the development of the same clinical symptoms. Technical PCBs which are dominating in occupational and environmental exposure until now must be judged as toxic for reproduction: dermal exposure (especially in accidents) should be considered as an important route of exposure beside inhalation. Work to list possible PCB exposure risks and to develop ways to reduce these risks are necessary now.

Abnormalities, Drug-Induced↗