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Biomedical subjects

R Bascom

Publications and source records attributed to R Bascom.

30 records · Page 2Linked to original sources
PubMed1986

Peripheral eosinophilia and respiratory symptoms in rubber injection press operators: a case-control study.

To evaluate a suspected association between an outbreak of acute respiratory illness and eosinophilia and employment as a rubber worker, we performed a retrospective review of medical records of rubber workers employed from September 1983 to July 1984 in a plant housing a thermoinjection process. Twenty-five workers met the case definition of a respiratory illness requiring a physician visit. The predominant respiratory illness was acute in onset with cough, chest tightness, and dyspnea. Peripheral eosinophilia, up to 40% of white blood cells in a peripheral smear, was seen in 10 of 18 (56%) cases. Twenty-one of 25 white males with respiratory symptoms were employed in the thermoinjection process (odds ratio = 22, p less than .001). Smoking and employment in this process contributed independently to an increased risk of being a case as determined by a logistic regression analysis. Return to the plant building caused recurrence of symptoms in most cases, and these workers have been transferred or left the company. We conclude that a strong previously unrecognized association exists between employment in this neoprene rubber thermoinjection process and the development of an acute respiratory illness.

Adult↗
PubMed1986

Bronchoconstriction induced by distilled water. Sensitivity in asthmatics and relationship to exercise-induced bronchospasm.

We studied the ability of bronchial challenge with an ultrasonically produced, distilled water aerosol to detect airways hyperreactivity in asthmatics and also evaluated its relationship to exercise-induced bronchoconstriction. Fifteen asthmatics and 10 normal subjects inhaled, at room temperature, distilled water aerosol in increasing concentrations. On a separate day, each subject performed a standard methacholine challenge. On the third day, all asthmatics exercised on a treadmill for 6 min at 90% maximal heart rate while breathing room-temperature, dry air. Pulmonary mechanics (FEV1 and SGaw) were measured before and after each challenge. Seven of the asthmatics and all of the normal subjects did not react to challenge with distilled water. Distilled-water challenge caused a 20% decrease in FEV1 in only 53% (8 of the 15) asthmatics, whereas all of the asthmatics reacted to methacholine challenge with a 20% fall in FEV1. Thus, distilled water was not a sensitive challenge procedure for the detection of airways hyperreactivity in asthma and it cannot be used as a routine screening test. However, in the asthmatics, the response to distilled water challenge correlated significantly with the response to exercise (r = 0.81, p less than 0.001). Seven asthmatics were reactive to both exercise and water, 7 were reactive to neither exercise nor water, and 1 reacted to water but not to exercise. Cromolyn completely or partially blocked both distilled-water- and exercise-induced bronchospasm in the reactive asthmatics.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1985

Specific bronchoalveolar lavage IgG antibody in hypersensitivity pneumonitis from diphenylmethane diisocyanate.

We evaluated a patient for dyspnea, fever, malaise, and hypoxemia that developed after exposure to diphenylmethane diisocyanate (MDI). Specific inhalation challenge with MDI caused fever, leukocytosis, a restrictive decline in forced vital capacity, and a decrease in Pao2 several hours after challenge. Bronchoalveolar lavage 24 h after challenge showed lymphocytic alveolitis. Specific IgG antibodies to MDI human serum albumin (MDI-HSA) conjugate were demonstrated in serum and bronchial lavage fluid using the enzyme-linked immunoabsorbent (ELISA) technique. These findings suggest participation of both humoral and cellular immunity in the pathogenesis of hypersensitivity pneumonitis from isocyanate exposure.

Alveolitis, Extrinsic Allergic↗
PubMed1979

Muscle relaxation in mechanically ventilated infants.

We evaluated the effect of muscle paralysis on gas exchange and incidence of pneumothorax in 35 severely ill infants on mechanical ventilation. Pancuronium (0.1 mg/kg) was given repeatedly until spontaneous respirations ceased in infants with inadequate gas exchange with FIO2 greater than 0.60, or peak inspiratory pressure greater than 30 cm H2O, or who were breathing out of phase with the respirator. Of 27 infants who had an alveolar-arterial oxygen gradient greater than 300 torr before paralysis, AaDO2 improved by greater than 100 torr within one hour of paralysis in only two infants; it worsened in two infants within the same period. By six hours postparalysis, 12 of 27 infants had improved, five of whom had had a worsening AaDO2 before administration of pancuronium. Changes in oxygenation were unrelated to changes in arterial carbon dioxide tension in most infants. Peak transpulmonary pressures after paralysis were lower than during spontaneous breathing, and may explain the low incidence of pneumothorax (3 of 35) during paralysis. Since those who improved could not be distinguished by birth weight, gestational age, or diagnosis, pancuronium might be worthy of trial in a mechanically ventilated infant with severe lung disease who is at risk for pneumothorax.

Carbon Dioxide↗
PubMedDate not supplied

Elevated serum IgE, eosinophilia, and lung function in rubber workers.

We previously reported an outbreak of acute respiratory illness associated with eosinophilia in a group of rubber workers who performed a thermoinjection process in which synthetic rubber was heated and then injected onto metal molds. This study was conducted to determine if persistent respiratory health effects were associated with this work area and to explore the possible allergic etiology of this syndrome. A survey was performed 1 mo after a major improvement in area ventilation and consisted of baseline, cross-shift, and cross-week spirometry; diffusing capacity; serum immunoglobulin E (IgE), total eosinophil count; and skin patch testing. Baseline lung function, cross-shift, and cross-week spirometry were not significantly worse in the exposed group as compared to the control group. However, either eosinophilia (greater than 450/mm3) or elevated serum IgE (greater than 470 ng/ml) were present in 44% of exposed workers vs. 11% of the control group (p = .003). Nine months later, neither eosinophilia nor elevated IgE were associated with employment in this work area. We conclude that employment in the thermoinjection process was associated with eosinophilia and elevated IgE, which suggests sensitization to one of the components of the rubber, although no effect on pulmonary function could be demonstrated.

Adult↗
PubMedDate not supplied

Nasal inhalation challenge studies with sidestream tobacco smoke.

Environmental tobacco smoke (ETS) exposure is associated with rhinitis symptoms (i.e., runny nose and congestion) in some people. In an effort to better understand these symptoms, we recruited 18 historically ETS-sensitive subjects from the community and exposed them for 15 min to clean air and for 15 min to sidestream tobacco smoke (STS, 45 ppm carbon monoxide). Symptoms were recorded (0 = absent, 5 = severe), and posterior rhinomanometry was performed. There were significant changes in rhinitis symptoms (1.3 +/- 0.4 pre- versus 6.1 +/- 0.5 post-STS, p less than .05); nasal airway resistance (2.86 +/- 0.2 pre- versus 4.49 +/- 0.6 post-STS, p less than .05), and maximum inspiratory flow (2.74 +/- 0.3 pre- versus 2.14 +/- 0.3 post-STS, p less than .05). A spectrum of individual responsiveness to ETS was observed, and nasal resistance increased from 0% to 265%. Increased nasal resistance occurred primarily at the upstream or flow-limiting segment of the nasal airway.

Adult↗
PubMedDate not supplied

Occupational and environmental respiratory diseases: a medicolegal primer for physicians.

This article is an introduction to medicine and the law with specific reference to occupational and environmental respiratory diseases. It provides an initial orientation for practicing physicians and includes basic definitions, practices and procedures, and helpful hints. Basic information about impairment and disability evaluations are reviewed.

Environmental Exposure↗
PubMedDate not supplied

Don't just "do spirometry"--closing the loop in workplace spirometry programs.

The authors acknowledge that surveillance is a word that often causes eyes to glaze over and recognize that spirometry is often a casualty of a routine approach to surveillance. This article describes how to use spirometry as an active part of an on-site workplace occupational health program whose emphasis is avoiding trouble by knowing where and how to look for signs of occupational lung disease.

Humans↗