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Biomedical subjects

D P Schlueter

Publications and source records attributed to D P Schlueter.

At least 19 recordsLinked to original sources
PubMed1991

Screening for occupational asthma: a word of caution.

The diagnosis of occupational asthma may be difficult due to the complex mechanisms inducing the disorder. Identification of the offending agent after historical documentation may be difficult without bronchial challenge. The hallmark of asthma is bronchial hyperreactivity as detected by methacholine challenge, and this test could be considered as a screening test for asthma in the workplace. Four cases are presented that document changes in methacholine airway reactivity dependent on temporal association with exposure to the workplace or the specific offending agent. This indicates a need for a careful evaluation of symptoms relative to exposure in patients suspected for workplace asthma as well as serial determinations of methacholine response to detect potential variability in the airway reactivity.

Adult↗
PubMed1989

Bronchial hyperreactivity and cough due to angiotensin-converting enzyme inhibitors.

Seventeen patients using angiotensin-converting enzyme (ACE) inhibitors for hypertension were evaluated with baseline spirometry followed by determination of bronchial reactivity by challenge with methacholine. There were nine coughers and eight noncoughers in the study. Among the nine coughers, eight demonstrated bronchial hyperreactivity. Conversely, none of the noncoughers disclosed bronchial hyperreactivity. Eight of the nine coughers were rechallenged two to six months following cessation of ACE inhibitor therapy. Six of these eight showed persistent bronchial hyperreactivity. We conclude that cough is associated with the use of ACE inhibitors in patients with underlying bronchial hyperreactivity. The findings indicate caution in administration of ACE inhibitors in asthmatic patients and those with known bronchial hyperreactivity.

Asthma↗
PubMed1988

Welders' pneumoconiosis: tissue elemental microanalysis by energy dispersive x ray analysis.

Histological examination on lung tissue obtained from 10 symptomatic welders was performed by two certified pathologists without the knowledge of the patients' clinical condition. In all cases, there was some degree of interstitial fibrosis; in five the degree of fibrosis was considered to be moderate to pronounced. The tissue was also analysed by energy dispersive x ray analysis and elemental contents were compared with age matched controls. There was a large amount of iron in the lungs of welders but the silicon content did not differ from the control subjects. No specific foreign element was detected. It is concluded that (1) interstitial pulmonary fibrosis is seen in some welders and (2) the cause of fibrosis does not appear to be coexisting silicosis.

Adult↗
PubMed1987

Passive transfer of methacholine sensitivity from man to monkey.

A model of human allergic disease, in which nonhuman primates were infused with serum from allergic humans and challenged with appropriate antigen, was used to determine whether the animals also develop hyperreactive airways characteristic of asthma. Anesthetized monkeys were insufflated with increasing concentrations of methacholine aerosol, and changes in pulmonary function were measured. Airway reactivity as assessed by the dose of methacholine aerosol culminating in apnea was determined after infusion of serum from allergic or nonallergic humans or with heated allergic serum. A comparison of the results indicated that only infusion of unheated serum from allergic humans resulted in an increase in airway reactivity to aerosolized methacholine. These results suggest that a factor in the serum of allergic humans may play a role in the hyperreactivity of airways characteristic of asthma.

Animals↗
PubMed1986

Ipratropium bromide in asthma. A review of the literature.

In comparative studies of asthma, ipratropium bromide has been shown to have a slower onset of bronchodilator action but a longer duration of effect than beta agonists. An additive effect of ipratropium and beta agonists has been demonstrated, in addition to prolongation of the bronchodilator response. Most studies do not show a definite difference in responsiveness of atopic versus nonatopic asthmatic patients; there are, however, reports indicating a greater responsiveness to anticholinergic agents than to beta agonists in patients with chronic bronchitis and emphysema. Ipratropium has been shown not to affect mucociliary clearance, sputum volume, or viscosity. It effectively inhibits the bronchial response to methacholine and, to a lesser degree, to histamine, serotonin, bradykinin, and antigen. Protection against exercise-induced asthma with this drug has been variable, but ipratropium has been found particularly useful in psychogenic asthma. Its role in occupational asthma remains to be determined.

Aging↗
PubMed1986

The pathophysiologic and roentgenologic effects of chest irradiation in breast carcinoma.

We studied the effects of radiation therapy on lung function in 21 patients who underwent modified radical mastectomy and radiotherapy for breast carcinoma. The patients had pulmonary function studies and chest X rays prior to radiation therapy and at six weeks, and three, six, and twelve months following radiation therapy. All pulmonary function studies showed a small but statistically significant decline within the first three months following radiation therapy. Changes in the moderate and large airways continued to occur after three months. None of the changes in pulmonary function were reversible. Radiographic changes occurred in 12 patients. These changes occurred later than the lung function changes (median time for the changes was twelve months) and were unrelated to changes in lung function.

Adult↗
PubMed1985

Antigen-induced enhancement of bronchial reactivity.

Bronchial hyperreactivity as determined by the airway response to methacholine was evaluated pre- and post-antigen challenge in three patients with specific antigen sensitivity. No significant change in pulmonary function was noticed after inhalation of antigen alone. However, transient but significant increase in methacholine responsiveness followed the antigen challenge. The studies indicate a need for a nonspecific inhalation challenge following a negative antigen challenge when clinically indicated.

Adult↗
PubMed1979

Pulmonary function in rabbits with BCG-induced lung disease.

This study was performed to determine whether the lung histological changes which occur in rabbits following intravenous injection of killed Bacilli Calmette-Guérin (BCG) are accompanied by measurable changes in pulmonary function. We measured pulmonary function in New Zealand white rabbits 3 weeks after intravenous injection of BCG and in normal rabbits. After a tracheostomy and carotid artery catheterization was performed, each anesthetized rabbit was placed in a body plethysmograph for pulmonary function testing. Following the measurements, the lungs were removed for weighing and histological evaluation. In the BCG-treated rabbits, the lung weight/body weight ratios were 152% greater, the pulmonary resistance was 104% higher, dynamic compliance was 45% lower, minute ventilation was 28% greater, and the delta AaPO2 gradient was 13 torr higher than in the normal control rabbits. Histological evaluation of the BCG-treated animals revealed diffuse pulmonary involvement with non-caseating granulomas.

Airway Resistance↗
PubMed1979

Airway response to hair spray in normal subjects and subjects with hyperreactive airways.

Short-term 20-second exposure to hair sprays A and B failed to show significant decreases in maximum expiratory flow rates at low pulmonary volumes in normal subjects; however, significant decreases were observed with hair spray B in eight subjects with hyperractive airways (abnormal response to inhalation of methacholine). On the partial flow-volume curves, flows at 40 percent and 25 percent of forced vital capacity decreased 8.9 to 10.3 percent and 14 to 18.7 percent, respectively. The hair sprays differed in their content of perfume and plasticizer, and since the latter is generally considered nontoxic at room temperature, the perfume may be the responsible agent. It would appear from this study that normal healthy individuals are at little risk, at least from brief exposure to hair spray; however, in the presence of hyperreactive airways, as seen in asthmatic subjects and in some people with allergic rhinitis and viral respiratory infections, an immediate response of the airways may result from exposure to some hair sprays.

Aerosols↗
PubMed1978

Early detection of hypersensitivity pneumonitis in office workers.

Symptoms of hypersensitivity pneumonitis in three employees in an office building led to an investigation of their work environment. An open spray water air cooling system was implicated when inhalation challenge with the spray water caused acute illness in one of them. A questionnaire survey of the 4,023 co-workers identified 48 other suspect cases, and laboaratory studies confirmed hypersensitivity pneumonitis in three additional workers of this group. A significant change in pulmonary function, occurring only after exposure to the work environment, was the most useful laboratory finding and was found in five workers with no other pulmonary abnormalities, but not is asymptomatic workers or controls, since five of the six patients with hypersensitivy pneumonitis worked in offices cooled by the spray water system and since three had positive responses to inhalation challenge, use of the spray water system was discontinued. The affected workers improved after they were removed from the office complex.

Adult↗
PubMed1978

Occupational asthma due to tetrachlorophthalic anhydride.

The plastics industry utilizes a number of organic chemicals which have the potential of producing pulmonary reactions, particularly in susceptible individuals. Five workers are reported who were involved in the production of epoxy resins and developed recurrent respiratory symptoms and physiologic abnormalities following exposure to tetrachlorophthalic anhydride (TCPA). Inhalation challenge with TCPA reproduced their symptoms and demonstrated both an immediate and late (4-6 hours) physiologic response. Although the clinical picture strongly suggested a hypersensitivity reaction, immunologic studies failed to demonstrate precipitating or specific IgE antibody. Avoidance of exposure resulted in resolution of symptoms; however, three of the five individuals had residual functional impairment.

Adult↗
PubMed1978

Bathtub refinisher's lung: an unusual response to toluene diisocyanate.

Immunologic and inhalation challenge studies were performed on a patient engaged in bathtub refinishing who developed systemic and respiratory symptoms suggestive of hypersensitivity pneumonitis temporally related to his occupation. The refinishing process used a catalyst containing toluene diisocyanate, and all clinical features of the disorder were reproduced by challenge. No immunologic mechanism could be identified. A change of occupation resulted in complete relief of symptoms.

Alveolitis, Extrinsic Allergic↗
PubMed1977

Sarcoidosis in hypersensitivity pneumonitis.

An abnormal chest x-ray film showing hilar adenopathy, diffuse interstitial pulmonary infiltrations, or both, combined with a tissue biopsy revealing noncaseating granuloma, are suggestive of sarcoidosis; however, non-caseating granuloma may also be found in other forms of pulmonary disease. Immunologic and environmental evaluation of three patients with the diagnosis of sarcoidosis made by the above criteria, revealed hypersensitivity pneumonitis in all. Since therapeutic considerations in these two diseases are different (avoidance being the mainstay in hypersensitivity pneumonitis), all methods to ensure a correct diagnosis should be employed.

Adult↗
PubMed1976

Interstital lung disease due to contamination of forced air systems.

Eight patients had hypersensitivity pneumonitis due to contaminated home or office forced-air heating or air-conditioning systems. We studied their clinical and laboratory features, and the results indicated that this disease may occur as an acute or insidious form differing in type and intensity of respiratory and systemic symptoms. Thermophilic actinomycetes contaminatinf the forced air systems were identified as the sensitizing agents in most cases. Precipitating antibodies to the organisms could be shown in the serums of the patients and the antigen identified by immunofluorescent studies in the three lung biopsies examined by this method. Inhalation challenge studies with the cultured organism or other materials obtained from the forced air systems reproduced the clinical syndrome in the four patients tested. Avoidance of the contaminated system, and the use of corticosteroids in more severe cases,seems to be appropriate therapy for patients with this disease.

Actinomycetales↗