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Biomedical subjects

H Zwick

Publications and source records attributed to H Zwick.

At least 73 records · Page 4Linked to original sources
PubMed1991

Diagnostic sensitivity of different techniques in the diagnosis of lung tumors with the flexible fiberoptic bronchoscope. Comparison of brush biopsy, imprint cytology of forceps biopsy, and histology of forceps biopsy.

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.

Biopsy↗
PubMed1991

Computerized detection of respiratory events during sleep from rapid increases in oxyhemoglobin saturation.

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 less than 0.0001) than in HSN (r = 0.722, p less than 0.001). The same was true for DESAT (OSA: r = 0.896, p less than 0.0001; HSN: r = 0.637, p less than 0.01). In conclusion, computer-found rapid resaturations are more sensitive than desaturations for the detection of respiratory events during sleep from oximetry.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1991

Allergenic structures in cockroach hypersensitivity.

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.

Animals↗
PubMed1991

Personal spore sampling and indirect immunofluorescent test for exploration of hypersensitivity pneumonitis due to mould spores.

Sensitization to mould spores was investigated in six patients with hypersensitivity pneumonitis, eight patients with idiopathic lung fibrosis, and six healthy controls by immunodiffusion and immunofluorescent testing of personal spore samples. The new technique of personal spore sampling with the Burkard personal volumetric air sampler and indirect immunofluorescent test for detection of spore-specific IgG and IgM confirmed that five patients with hypersensitivity pneumonitis and four with lung fibrosis were actually exposed and sensitized to moulds. Personal spore sampling and subsequent immunofluorescent tests represent sensitive tools for detection of individual mould sensitization and air quality control.

Adult↗
PubMed1991

Pollen sensitization and allergy in children depend on the pollen load.

We investigated the influence of grass and birch pollen load on specific IgE response, skin prick test reactivity, and manifest allergic disorders of the eyes and respiratory tract. The study population was two groups of 200 children each, matched in sex and age, who were domiciled in areas with high and low pollen load, respectively. In the children from the area with high pollen load, the grass pollen load was 1.7 times higher than in the other and only specific IgE to grass pollen was found to be present more frequently (23.5% as against 12.5%; P less than 0.01). In the same area, the birch pollen load was 2.8 times higher, which caused specific IgE in 10.5% as against 3.5% of the other group (P less than 0.01) as well as positive skin prick test in 9.0% as against 3.5% (P less than 0.05). Reports of subjective complaints were rare among the group with high pollen load but the total number did not amount to a statistically significant increase. There was no difference between the two groups concerning sensitization and allergy to house dust mite. This suggests that the influence of the pollen load is strongest on the development of specific IgE, and less on skin test reactivity and manifest allergies.

Air Pollutants↗
PubMed1991

Inspiratory muscle performance and pulmonary function changes in insulin-dependent diabetes mellitus.

The study examined pulmonary function parameters of 36 patients with insulin-dependent diabetes mellitus and analyzed their inspiratory muscle performance. The control group consisted of 40 healthy reference persons of a sex ratio, age, height, and weight distribution similar to those of the patients. The pulmonary function test included the measurement of the lung volumes and the maximal expiratory flow-volume curves. The values of maximal sniff esophageal (Pes) and transdiaphragmatic pressures (Pdi) were used as parameters for global inspiratory muscle strength and diaphragm strength, respectively. The 12-s maximum voluntary ventilation (MVV) test supplied the parameter of inspiratory muscle endurance. The diabetic patients showed a highly significant decreased value for their inspiratory vital capacity (VCin) compared with that of the control subjects (4.75 +/- 0.84 versus 5.36 +/- 1.37 L; p less than 0.01). Inspiratory muscle performance in the diabetic patients was also restricted. Sniff Pes was significantly lower in the diabetic group (p less than 0.05); sniff Pdi (p less than 0.01) and MVV (p less than 0.05) were also low. The results did not correlate with either the duration of diabetes or the quality of metabolic control measured by glycosylated hemoglobin concentration. The reduction of VCin in diabetic patients may have been caused partly by the reduced capacity of the inspiratory muscles.

Adult↗
PubMed1991

Effects of ozone on the respiratory health, allergic sensitization, and cellular immune system in children.

To investigate the lasting effects of high ozone concentrations under environmental conditions, we examined the respiratory health, pulmonary function, bronchial hyperresponsiveness to methacholine, allergic sensitization, and lymphocyte subpopulations of 10- to 14-yr-old children. A total of 218 children recruited from an area with high ozone concentrations (Group A) were tested against 281 children coming from an area with low ozone concentrations (Group B). As to subjective complaints, categorized as "usually cough with or without phlegm," "breathlessness," and "susceptibility to chest colds," there was no difference between the two groups. The lung function parameters were similar, but in Group A subjects' bronchial hyperresponsiveness occurred more frequently and was found to be more severe than in Group B (29.4 versus 19.9%, p less than 0.02; PD20 2,100 +/- 87 versus 2,350 +/- 58 micrograms, p less than 0.05). In both groups the number of children who had been suffering from allergic diseases and sensitization to aeroallergens, found by means of the skin test, was the same. Comparison of the total IgE levels showed no difference at all between the two groups. As far as the white blood cells are concerned, the total and differential cell count was the same, whereas lymphocyte subpopulations showed readily recognizable changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pollution↗
PubMed1991

Breathing during sleep in patients treated for obstructive sleep apnea. Nasal CPAP for only part of the night.

To determine whether long-term NCPAP therapy influences severity of sleep disordered breathing during the second part of a night when NCPAP is applied for only the first four hours of sleep, we studied 21 patients with OSA receiving NCPAP therapy for 253 +/- 41.6 days. Results from polysomnography for the period after withdrawal from NCPAP (night B) were compared to the corresponding period of sleep prior to initiation of NCPAP therapy (night A). There was no significant change in RDI from night A (53.9 +/- 8.6) to night B (28.7 +/- 3.3), but maximal apnea length diminished from 55 +/- 2.9 s to 40 +/- 2.9 s (p less than 0.05). Whereas daytime Po2 and the amplitude of desaturations during sleep remained equal, overall oxygenation during sleep improved slightly (mean SaO2 night A = 90.6 +/- 0.9 percent; night B = 92.8 +/- 0.5 percent; p less than 0.05). Differences between nights A and B were more prominent the more severe sleep apnea had been prior to treatment and could not be explained by weight loss. There was strong correlation between improvements in oxygenation measurements and the daily time of NCPAP use. In conclusion, we found a subgroup of OSA patients receiving long-term NCPAP therapy with less disturbed ventilation during sleep following use of NCPAP for only the first part of the night, but in the majority of patients, sleep disordered breathing off NCPAP remained unchanged.

Female↗
PubMed1991

Acceptance of CPAP therapy for sleep apnea.

Although NCPAP is the most efficient nonsurgical treatment for patients with OSA, many patients do not accept sleeping with a nose mask. To determine the factors influencing acceptance, treatment with NCPAP was offered to 95 patients with an AHI greater than 15. After the first night on NCPAP, 47 of 65 patients decided to have NCPAP as a home therapy. Excessive daytime sleepiness was more frequently reported by acceptors than refusers. The frequency of complaints about psychomental symptoms such as poor mental performance and bad memory, was not different between the two groups. There was a close correlation between the rate of acceptance and the AHI as well as the number of positive answers to questions about symptoms of daytime sleepiness in a questionnaire, which correlated with the number and length of apneas. Acceptance of NCPAP was found to be dependent on the subjective feeling of impairment by hypersomnolence due to OSA.

Attitude to Health↗
PubMed1991

Mechanical load on the ventilatory muscles during an incremental cycle ergometer test.

An incremental cycle ergometer test performed with a total of 40 healthy subjects (25 male, 15 female) was used to study the mechanical load on the ventilatory muscles. The parameters for the mechanical load on the ventilatory muscles are the time integral of the oesophageal pressure and the mean oesophageal pressure change per time unit (dPoe/dTI) of each breathing manoeuvre. The pressure-time integral is the area delimited by the oesophageal pressure trace and the inspiratory time axis. It is expressed as a fraction of the product of the subject's maximum oesophageal pressure (Poe(max)) and total breath cycle duration (TTOT). This parameter is called oesophageal tension time index (TTIoe). The relationship between minute ventilation and these two parameters during ergometer test showed gender-specific variations because of the differences between men and women as to anthropometric data, lung function parameters and maximum ventilatory muscle strength. Moreover, the dPoe/dTI values significantly depend on the breathing frequency. The present study has provided evidence that, in general, the TTIoe and dPoe/dTI values in terms of a specific minute ventilation (VE) are higher in women than in men. Parameters for the mechanical load on the ventilatory muscles regarding the level of pressure to be generated as well as the duration and velocity of muscle contraction should therefore also allow for the gender of the patients.

Adult↗
PubMed1991

Quantification of sleep disordered breathing by computerized analysis of oximetry, heart rate and snoring.

Intermittent snoring and cyclic oscillations of heart rate and oxyhaemoglobin saturation (Sao2) are characteristic features of the obstructive sleep apnoea syndrome (OSAS). Thus, overnight recordings of laryngeal sounds and heart rate by a portable device (MESAM) and of Sao2 by oximetry are applicable to screen outpatients for the presence of OSAS. Computerized analysis for time intervals of constant heart rate and intervals between snoring sounds is used by MESAM to quantify respiratory disturbances during sleep. Rapid increases in Sao2 during the postapnoeic hyperventilation period together with the number of desaturations are used by a new software for quantitative analysis of oximetry. To elucidate reliability of results from automatically scored MESAM and oximetry recordings, we compared the four computer calculated respiratory disturbance indices from heart rate (RDIH), snoring (RDIS), resaturations (RDIR) and desaturations (RDID) with the apnoea plus hypopnoea index (AHI) from simultaneously performed polysomnography. The study population consisted of 53 snorers with an AHI of 19.0 +/- 2.6 (median +/- SEM; range 0.7-87.8). Whereas both RDI's from MESAM correlated rather weakly with the AHI from polysomnography (RDIH: r = 0.32, p less than 0.05; RDIS: r = 0.33, p less than 0.05), this correlation was much better for the RDI's from oximetry (RDIR: r = 0.951, RDID: r = 0.93; p much less than 0.0001). Accepting a plus/minus 30 percent difference from the AHI, the RDIR classified 77% of patients correctly, the RDID 62%, the RDIS 32% and the RDIH 23%. In conclusion, results from computerized analysis of oximetry for desaturations and rapid resaturations correlate more closely with polysomnography than those from automatic scoring of MESAM recordings.

Heart Rate↗
PubMed1990

Increased sensitization to aeroallergens in competitive swimmers.

Chlorine is used to disinfect swimming pools or as a constituent of other disinfection reagents. Pulmonary diseases are occasionally observed after exposure to chlorine. In 14 competitive swimmers and in 14 matched control subjects, we searched for clinically manifest allergies, subclinical sensitization to aeroallergens, imbalance of the cellular immune system, and bronchial hyperresponsiveness. Conjunctival or respiratory symptoms were found in 11 swimmers (2 cases of conjunctivitis, 4 rhinitis, 2 rhinoconjunctivitis, 1 laryngitis, and 2 bronchitis) and in 3 controls. Sensitization to aeroallergens was confirmed in 9 swimmers by skin test and in 11 swimmers by radioallergosorbent test (RAST), compared to findings in 4 and 5 controls, respectively. An altered cellular immune system, (i.e., imbalance in T-cell system, B-cell system, or natural killer cells) was detected in 7 swimmers and only 2 controls. Bronchial hyperresponsiveness to methacholine was seen in 11 swimmers and 5 controls. This higher incidence of allergic diseases and subclinical sensitization to aeroallergens, disorders of the cellular immune system, and bronchial hyperresponsiveness in competitive swimmers compared with control subjects could be due to repeated exposure to chlorine in swimming pools.

Adolescent↗
PubMed1990

Flow-volume curves in obstructive sleep apnea and snoring.

The diagnostic value of flow-volume curves for sleep apnea was studied in 32 patients with obstructive sleep apnea, 40 simple snorers, and 30 healthy nonsnorers. A sawtooth appearance of the flow-volume curve was seen in 22 of the sleep apnea patients (69%), 14 of the simple snorers (35%), and 10 of the nonsnorers (33%). The ratio of midexpiratory flow (FEF 50) to midinspiratory flow (FIF 50) was greater than 1 in 6 of the sleep apnea patients (19%), 3 of the simple snorers (8%), and 2 of the nonsnorers (7%). Thus, only the sawtooth sign was more frequently found in sleep apnea patients than in controls (p less than 0.01). Sleep apnea patients with a sawtooth appearance of the flow-volume curve had a higher apnea index (38.7 +/- 22 vs. 21.5 +/- 12.1; p less than 0.01) and lower nocturnal minimum oxygen saturation (68.1% +/- 16.8 vs. 81.3% +/- 9.97; p less than 0.01) than those without. In symptomatic snorers, sensitivity of the sawtooth sign for sleep apnea was 72% and specificity 61%, for a FEF50/FIF50 ratio above 1 sensitivity was 17% and specificity 83%. In asymptomatic patients, sensitivity of either sign was extremely poor (33%) and specificity was 67% for the sawtooth sign and 85% for FEF50/FIF50 greater than 1. We conclude that abnormal flow-volume curves are of limited value for predicting sleep apnea.

Adult↗
PubMed1990

Bronchoalveolar lavage in rheumatoid arthritis and secondary Sjögren's syndrome.

Bronchoalveolar lavage (BAL) was performed to investigate pulmonary involvement in 39 patients with rheumatoid arthritis (RA) and in 7 patients with RA and secondary Sjögren's syndrome, and compared to 12 healthy controls. Lymphocytosis (more than 15%) was seen in 25, and more than 3% neutrophil granulocytes in 8 of 39 patients with RA. Lymphocytosis and/or neutrophil granulocytosis was seen in both seropositive and seronegative patients irrespective of clinical or radiologic findings. Patients with RA with or without secondary Sjögren's syndrome had increased DR+ lymphocytes in BAL compared with peripheral blood. In 7 patients with secondary Sjögren's syndrome an increased helper/suppressor cell index (OKT4+/OKT8+: 7.65 +/- 2.10) and increased natural killer cells (OKNK+: 27.3 +/- 5.5%) were found, as compared to 39 other patients with RA (OKT4+/OKT8+: 2.16 +/- 0.33, p less than 0.05; OKNK+: 14.5 +/- 2.3%, p less than 0.05). These BAL data are further evidence of frequent subclinical interstitial pulmonary involvement in RA with differences in the active autoimmune process from those in secondary Sjögren's syndrome.

Aged↗
PubMed1990

Risk factors for sensitization to furred pets.

The risk factors for sensitization to pets was investigated in 169 male pupils. A recent or former contact with cats, dogs, and guinea pigs in own home was reported in 52 (30.8%), 42 (24.9%), and 20 (11.8%) study subjects, respectively. Clinically manifested allergy was found in two probands to cats and in two others to guinea pigs, three of them had formerly had pets and one proband with allergic rhinitis to cats had never had any pet. Sensitization to animals and aeroallergens was investigated with Phadezym-RAST. Only owners of cats had a higher incidence of cat sensitization than probands without direct contact (26.9% versus 10.3%, P less than 0.01). No statistically significant difference in sensitization to dogs and guinea pigs was found in groups with and without these pets. A strong correlation existed between sensitization to pets and other aeroallergens (house dust mite: P less than 0.025, birch pollen: P less than 0.0001, mugwort: P less than 0.0001, and grass pollens: P less than 0.0001). No association was found between sensitization to pets and smoking history, bronchial hyperreactivity to methacholine or radiological findings of the paranasal sinus.

Adolescent↗
PubMed1990

Dependence of maximal sniff generated mouth and transdiaphragmatic pressures on lung volume.

The maximal sniff generated mouth and transdiaphragmatic pressures of six healthy volunteers (three women and three men) were measured at various lung volumes between residual volume and 95% of total lung capacity. At residual volume the mean (SD) maximum transdiaphragmatic pressure was 163 (18) cm H2O (1 cm H2O = 0.0981 kPa). With increasing lung volume the maximum pressures generated declined, so that at 95% of total lung capacity the mean pressure was 68 (15) cm H2O. Mouth pressures showed a similar relation to lung volume. At residual volume the mean maximum mouth pressure was 74 (8) cm H2O, compared with 38 (6) cm H2O at 95% of total lung capacity. The relation between pressure and lung volume was linear for measurements at lung volume levels between residual volume and 85% of total lung capacity; values at 95% of total lung capacity, however, were lower than predicted from the linear regression of the other points. The use of a second order polynomial regression showed a higher coefficient of determination in all cases (0.72 and 0.69 for transdiaphragmatic and mouth pressures on the basis of all pressure values for all subjects). Sniff generated mouth and transdiaphragmatic pressures show a predictable dependence on lung volume, supporting their use as measures of global inspiratory muscle power and diaphragm strength respectively.

Adult↗
PubMed1990

A method for the elimination of artefacts in electric field plethysmography of the lung.

The reliability of electric plethysmography for respiration monitoring is reduced by artefacts caused by the cardiac activity, by motions, electromagnetic cross-talk and others. For artefact suppression, a constant-current field-plethysmography technique is discussed which uses the voltage of an auxiliary electrode in addition to the conventional four-electrode arrangement. By means of a differential amplifier, a respiration signal is produced which is almost entirely free from heart artefacts, while the intensity of additional artefacts is suppressed. In principle, the technique can also be used for the separate determination of the ventilation intensity of the two lungs.

Electric Conductivity↗