Wolfgang Popp
Massachusetts Institute of Technology
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Wolfgang Popp.
Cancer | 1991
Wolfgang Popp; Helmuth Rauscher; Leopold Ritschka; Susanne Redtenbacher; Hartmut Zwick; Werner Dutz
Brush and forceps biopsies were done consecutively in 186 cases of pulmonary neoplasia with a flexible fiberoptic bronchoscope guided by x‐ray television fluoroscopy. Imprint and histologic sections were prepared from all forceps biopsy specimens. The three techniques were compared for their diagnostic sensitivity. As a result 84.9% of all imprints, 80.6% of brush biopsy specimens, and 62.9% of histologic sections were positive for malignancy. The sensitivity of brush biopsy specimens was independent of the location and morphology of the tumors, but the sensitivity of forceps biopsy specimens was lower in neoplasms unidentified by bronchoscopy. The sensitivity of the diagnostic accuracy when all three methods were used jointly was 97.3%, and the specificity was 100%. Agreement in the final morphologic tumor type was found in 130 of 150 cases (86.7%) by positive brush biopsy specimens, in 136 of 158 cases (86.1%) by positive imprint cytology, and in 104 of 117 cases (88.9%) by positive histology from forceps biopsy specimens. For routine bronchoscopy, all three methods should be used in combination to obtain the highest diagnostic yield.
Lung | 1991
Helmuth Rauscher; Wolfgang Popp; Hartmut Zwick
A computerized search for rapid resaturation (RES)—defined as increases in oxyhemoglobin saturation (SaO2) of 3% or more within 10 s—was used to detect apneas and hypopneas during sleep by the episodes of compensatory hyperventilation following them. Results were compared to those from computerized search for desaturations (DESAT)—defined as decreases in SaO2 of 4% or more within 40 s—and to simultaneous polysomnography.We studied 30 patients with obstructive sleep apnea (OSA) with an apnea plus hypopnea index (AHI) of 30.8±6.9 (median ± SEM) and 23 habitual snorers (HSN) with an AHI of 7±1.5. Manual scoring of polysomnography revealed 7965 respiratory events (6192 apneas, 1773 hypopneas) in OSA patients and 940 events (411 apneas, 529 hypopneas) in the HSN group. In OSA patients, the computer found 96% of events by searching for RES and 87% by searching for DESAT. The percentage of computer-found events in OSA classified as true positive was 91% for RES and 97% for DESAT. In the HSN group, 83% of polysomnographically scored events were found by RES and 55% by DESAT, with 72% of RES and 84% of DESAT being true positive. The correlation of the number of computer-found RES with the number of events from polysomnography was better in OSA (r=0.862, p<0.0001) than in HSN (r=0.722, p<0.001). The same was true for DESAT (OSA: r=0.896, p<0.0001; HSN: r=0.637, p<0.01).In conclusion, computer-found rapid resaturations are more sensitive than desaturations for the detection of respiratory events during sleep from oximetry. Increased sensitivity of RES is accompanied by relatively well-preserved specificity.
Gerontology | 2003
Christian Wagner; Wolfgang Popp; Martin Posch; Clemens Vlasich; Angelika Rosenberger-Spitzy
Background: Infections due to Streptococcus pneumoniae are the major cause of adult community-acquired pneumonia, especially in elderly persons with chronic medical conditions. Despite their well-documented efficacy against bacteraemic disease and deaths in the elderly population, pneumococcal polysaccharide vaccines are still very much underused. Objective: A retrospective, case-controlled study was performed to investigate the impact of vaccination with a polysaccharide pneumococcal vaccine, together with other risk factors, on the incidence of pneumonia and deaths in patients in a long-stay geriatric hospital. Methods: Subjects were 1,077 residents in a long-stay geriatric hospital in Vienna, Austria, including 359 patients diagnosed as having pneumonia during the period from July 1996 to October 1998 and 718 control subjects. Two controls resident in the hospital during the same time period were matched for each case according to demographic characteristics, chronic illness, and duration of stay in the geriatric ward. The vaccination status was established for all subjects. A logistic regression analysis was performed to assess the efficacy of vaccination and the impact of other cofactors on disease and death. Results: In cases and controls, 514 (47.7%) had received a pneumococcal vaccine within 2 years prior to the study. There were no differences in demographic characteristics, underlying medical conditions, or duration of stay in the hospital between vaccinated and non-vaccinated patients. In patients diagnosed with pneumonia, 66% were unvaccinated. Logistic regression analysis showed that vaccination significantly decreased the risk of pneumonia (odds ratio 0.279; p < 0.0001). Of the cofactors tested, only gender (lower risk in males) and diabetes mellitus (higher risk) had any impact on disease risk and vaccine efficacy. There appeared to be a highly significant effect of vaccination, reducing the risk of all deaths (odds ratio 0.269; p < 0.0001) and deaths due to pneumonia (odds ratio 0.331; p < 0.0001). Conclusion: This study showed that vaccination with a polysaccharide pneumococcal vaccine is effective in all groups of geriatric subjects and has a consequential value for health and well-being of elderly institutionalized patients.
The Journal of Allergy and Clinical Immunology | 1991
Hartmut Zwick; Wolfgang Popp; Kaspar Sertl; Helmuth Rauscher; Theodor Wanke
The tissues from which cockroach allergens were derived were identified by use of serum IgE of five patients with allergic rhinitis and bronchial asthma as a result of hypersensitivity to German cockroach. RAST and skin test results demonstrated four of five patients to be positive to cockroach only, and one patient was tested positive to house dust mite as well. Allergen-specific IgE binding to German cockroach was investigated by cryostat sections by means of immunofluorescent test. In all patients with cockroach hypersensitivity, we found IgE bound to the gastrointestinal epithelium and contents of the intestinal tract. In four cases, IgE was also bound to the Malpighian vessels (equivalent in function to kidneys). In three cases, IgE was also bound to the ovarian cells. All cases revealed cytoplasmic staining.
Cancer | 1992
Wolfgang Popp; Monika Merkle; Brigitte Schreiber; Helmuth Rauscher; Leopold Ritschka; Hartmut Zwick
Background. Bronchoscopic investigations of lung tumors require high diagnostic accuracy. Sometimes the combination of brush biopsy with cytologic and histologic examination of forceps‐obtained biopsy specimens fails to diagnose tumors. Techniques with a minimum risk and low cost when repeated several times could increase the efficiency of tumor diagnosis and help to avoid rebronchoscopy.
Respiration | 1994
D. Kiss; Wolfgang Popp; Christian Wagner; Hartmut Zwick; K. Sertl
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.
The Journal of Allergy and Clinical Immunology | 1994
Wolfgang Popp; Andreas Böck; Kurt Herkner; Christian Wagner; Hartmut Zwick; Kaspar Sertl
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 (Spearmans r = -0.198) and FEV1 (percent predicted) (Spearmans 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.
Medicine and Science in Sports and Exercise | 1993
Dieter Formanek; Theodor Wanke; Heinz Lahrmann; Helmuth Rauscher; Wolfgang Popp; Hartmut Zwick
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.
Respiration | 1992
Wolfgang Popp; Kurt Herkner; Andreas Böck; Helmuth Rauscher; Theodor Wanke; Leopold Ritschka; Hartmut Zwick
We investigated the changes in the cellular and humoral immune system in bronchoalveolar lavage (BAL) performed in 22 patients with pulmonary sarcoidosis and in 14 normal control subjects and their interactions with lung function parameters. Lymphocytosis, the increase in OKT4+ lymphocytes and OKT4+OKDR+ lymphocytes correlated with the increase in immunoglobulins, especially IgG, IgA and kappa chain assembled immunoglobulins. The transferrin levels obtained in BAL were found to be higher in patients with sarcoidosis, and they correlated with the cellular and, more closely, with other humoral findings. A negative correlation existed between the ventilatory parameters and the cell count and humoral findings. In addition, we found a negative correlation between the diffusing capacity for carbon monoxide and other cellular findings, which was most pronounced with reference to lymphocytes, OKT4+ lymphocytes and the OKT4+/OKT8+ ratio. These results underscore the role of OKT4+ lymphocytes, activated OKT4+OKDR+ lymphocytes and transferrin in the increase in immunoglobulins, mainly kappa chain isotypes. Because of the relationship between these changes and ventilatory parameters, and the diffusing capacity, the above results also reveal the clinical relevance of our findings.
Respiration | 1994
Wolfgang Popp; Otto Braun; Leopold Ritschka; O. Scherak; Gernot Kolarz; Helmuth Rauscher; Wolfgang Kumpan; Wolfgang Küster; Christian Wagner; Hartmut Zwick
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