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Biomedical subjects

G J Beck

Publications and source records attributed to G J Beck.

At least 73 records · Page 4Linked to original sources
PubMed1985

Airway reactivity and cotton bract-induced bronchial obstruction.

Most seemingly healthy persons challenged with an aerosol of cotton bract extract develop some degree of bronchospasm. The role of nonspecific reactivity of the airways in this reaction to cotton bract extract is undefined. We examined the relationship between airway responses to cotton bract extract and to methacholine, as well as between airway responses to cotton bract extract and to a bronchodilator. Twenty-two healthy subjects were screened for sensitivity to inhaled cotton bract extract. Pulmonary function was measured using partial expiratory flow-volume curves on which flow at 60 percent of the control vital capacity below total lung capacity was measured (MEF40%[P]) following ten minutes of inhalation of cotton bract extract. In the group screened, 12 were found to be responders to the extract, with drops in MEF40%(P) of 20 percent or more, and ten were found to be nonresponders. On separate days, we measured the responses of our subjects' airways to inhaled metaproterenol and methacholine. The mean threshold dose for methacholine in the responding group was 26.8 mg/ml, as compared to 55.6 mg/ml for the nonresponders (t = 2.52; p less than 0.05). Furthermore, the mean percent increase in MEF40%(P) following inhalation of metaproterenol was 41 percent in responders and 24 percent in nonresponders (t = 2.19; p less than 0.05). We conclude that some responders to cotton bract extract exhibit greater reactivity of the airways than nonresponders.

Adult↗
PubMed1985

A comparison of sector and linear array scanners for the measurement of the fetal femur.

This study was designed to determine whether differences between sector and linear array scanners introduce variability in fetal femur length measurements, used to determine gestational age. Twenty transducers from 15 machines were tested with the manufacturers' approval. Machines were coded to maintain anonymity. Three different sized sections of plastic straws were scanned in a water bath. All measurements were made by the same investigator. Measurements were adjusted to compensate for the difference in sound velocity in water, which introduced a 3.36 per cent error in apparent depth of the image for linear array scanners, and a 3.36 per cent error in apparent depth and length for sector scanners. A large variation in measurements was obtained, although the differences were usually within acceptable limits (approximately 4 per cent). Linear array scanners were found to give similar readings as sector scanners.

Embryonic and Fetal Development↗
PubMed1985

Mechanically assisted ventilation in a community hospital. Immediate outcome, hospital charges, and follow-up of patients.

In 100 consecutive patients undergoing mechanically assisted ventilation, we prospectively determined immediate survival, hospitalization charges, and subsequent one-year outcome. Sixty percent of the patients survived the episode of assisted ventilation. This survival decreased to 50% at the time of hospital discharge and to 33% one year after hospitalization. There were no posthospitalization deaths in patients less than age 50 years. In those patients older than 70 years, however, 51% were dead by the time of hospital discharge and 73% died by one year following discharge. Comparison of features that reflect the magnitude of intensive respiratory care, such as hours of ventilation and intensive care unit (ICU) length of stay, disclosed no statistically significant differences between survivors and nonsurvivors at discharge. Hospitalization charges averaged $10,968 per patient. The total charge for respiratory therapy services (including arterial blood gas determinations) averaged $2,200. Respiratory care service charges were only marginally different between survivors and nonsurvivors. By contrast, total charges and total length of stay were greater for the survivors. Resource use in the intensive care setting as reflected by hours of mechanical ventilation and ICU length of stay was similar in both survivors and nonsurvivors, with the larger total cost for survivors relating primarily to care outside the ICU. Also, we confirm that prognosis is excellent in patients less than 50 years of age who survive mechanically assisted ventilation for acute respiratory failure and that extubation in elderly patients is not necessarily indicative of a good prognosis.

Adolescent↗
PubMed1984

Cotton dust and smoking effects on lung function in cotton textile workers.

Both smoking and exposure to cotton textile dust have been associated with the development of chronic obstructive lung disease. The relative importance of these two effects are examined in this paper. This investigation is based on a cross-sectional study of white active and retire cotton textile workers 45 years and older seen in 1973 in Columbia, South Carolina with an average of 35 years worked in the mills. A questionnaire was completed and an expiratory flow volume curve obtained for each worker studied. Standard pulmonary function parameters including the forced vital capacity (FVC), the forced expired volume in one second (FEV1), and the maximum expiratory flow at 50% (MEF50%), and at 25% (MEF25%) were recorded. White residents 45 years and older from three communities studied from 1972 to 1974 were used as controls. A two-way analysis of variance examined both the effects of cotton dust and smoking on lung function. Both exposures significantly influenced lung function and were found to be additive and often equally important. When one effect was more important than the other, it was in FVC and FEV1 for cotton dust and in MEF50% and MEF25% for smoking.

Dust↗
PubMed1984

The relationship of respiratory symptoms and lung function loss in cotton textile workers.

We explored the relationship between a number of respiratory symptoms or symptom complexes (e.g., cough, recent wheeze, byssinosis) and lung function in white cotton textile workers (CTW) and control subjects 45 yr of age or older. The CTW were studied in 1973 and in 1979 in Columbia, South Carolina, and the control subjects were studied in 1972 and in 1978 in Lebanon, Connecticut. The CTW had a high prevalence of byssinosis (18%) and other symptoms. For each symptom or symptom complex, among persons with the symptom, CTW had lower lung function on the average than did control subjects. Also, among persons without the particular symptom, CTW had lower lung function than did control subjects. This pattern also occurred for persons without any respiratory symptoms (i.e., asymptomatic). Moreover, persons (CTW or control subjects separately) reporting the presence of a particular symptom had, in general, lower lung function than did those without the symptom. Among nonsmokers, all these same patterns usually held, but differences were often not statistically significant because of the small numbers of persons with symptoms. We conclude that on a group basis, respiratory function is more impaired in CTW than in control subjects with respiratory symptoms, that respiratory function is more impaired in persons (CTW or control subjects) with symptoms than in those without, and that even asymptomatic CTW have significantly greater lung function impairment than do control subjects.

Aged↗
PubMed1984

A prospective study of asthma in a rural community.

Changes in symptoms and pulmonary function among asthmatic subjects in the general population remain poorly characterized. We studied 1,303 white residents aged seven years and older in Lebanon, Conn, a rural community largely unaffected by air pollution or major occupational exposures. These residents were examined in 1972 and again in 1978. There were 73 asthmatic subjects seen in 1972 who were followed. In addition, we identified 278 persons in 1972 who complained of wheezing who were also seen in 1978. Of the original asthmatic subjects, 50 (68 percent) were in remission; and from the original nonasthmatic population, 19 (1.4 percent) new asthmatic subjects were identified. Similarly, the condition of 215 (77 percent) of those who initially complained of wheeze had improved, whereas 56 (4.6 percent) of those initially studied either developed new wheeze or saw their wheezing worsen. When the groups of persons complaining of wheeze and the asthmatic subjects were analyzed for the presence of chronic bronchitis, we found a significant correlation between wheeze and chronic bronchitis in individuals aged 18 years and older (p less than 0.001) for both men and women, and a significant correlation (p less than 0.001) between asthma and chronic bronchitis in women aged 18 years and older. Loss of pulmonary function over time measured in terms of the forced expiratory volume in one second and the forced expiratory flow at 50 percent of total lung capacity was consistently greater for asthmatic adults than for nonasthmatic adults. Furthermore, when individuals were studied by the severity and duration of their asthmatic symptoms, a trend of worse pulmonary function was seen in those individuals with chronic asthma. We conclude that remission rates among asthmatic subjects and persons with wheeze are high in individuals aged seven years and older, that chronic bronchitis is frequently associated with wheezing and a history of asthma in adults, and that significant abnormalities in pulmonary function as well as accelerated loss of pulmonary function are associated with asthma.

Adolescent↗
PubMed1984

Relations of smoking and diving experience to pulmonary function among U.S. Navy divers.

The relations of 4 pulmonary function parameters (measured from the forced expiratory spirogram) with diving experience (in years) and indices of cigarette smoking were examined in a group of 93 healthy U.S. Navy divers. Years of diving was not significantly related to lung function. The value for pack-years of smoking was inversely associated with both percentage of predicted forced expiratory volume in 1 s (FEV1) and percentage of predicted maximal midexpiratory flow rate (MMFR). Divers who have relatively heavy smoking histories may be at greater risk for developing significant decline in pulmonary function, and diving exposure factors other than years of diving may contribute to this risk.

Adult↗
PubMed1984

The pattern of lung function abnormalities in cotton textile workers.

Reversible airway obstruction has been shown to be a characteristic finding of early byssinosis. In the chronic phase of this disease, the patterns of respiratory abnormalities have not been well defined. We examined the lung function of a cohort of 383 older (45 yr of age or more), active and retired, cotton textile workers seen both in 1973 and in 1979 in Columbia, South Carolina. A group of control subjects consisted of 277 white community residents of comparable age from Lebanon, Connecticut. Using data at follow-up, 25% of the male and 14% of the female cotton textile workers had moderate to severe obstructive airway abnormalities, as opposed to 13 and 5% for male and female control subjects (p less than 0.01). There were fewer persons with restrictive than with obstructive lung patterns among cotton textile workers and control subjects, but again, abnormalities were more prevalent among cotton textile workers. Overall, 50% of male cotton textile workers and 37% of female cotton textile workers had some abnormality of lung function, as opposed to 29% of male and 20% of female control subjects (p less than 0.001). More abnormalities were present in cotton textile workers than in control subjects when only lifetime nonsmokers were examined. We conclude that there is an increased prevalence of both obstructive and restrictive lung function abnormalities among cotton textile workers when compared with control subjects, with the most common pattern being obstructive.

Age Factors↗
PubMed1983

Early gestational bleeding and pregnancy outcome: a multivariable analysis.

The effect of early vaginal bleeding on pregnancy outcome was assessed for 16 305 singleton stillborn and liveborn deliveries at three obstetric units in Jerusalem, Israel during 1975-1976. A total of 2385 women (14.6%) reported gestational bleeding before the seventh month of pregnancy. Of these, 2166 reported light bleeding (spotting), 191 heavy bleeding, and 28 both light and heavy bleeding. Logistic regression models revealed an unexpected interaction among light bleeding, hormone usage, and pregnancy outcome in that the risks of a low birth weight, pre-term and small-for-dates term delivery were significantly increased only for those women who had light bleeding and who had not used therapeutic hormones. Heavy vaginal bleeding, in contrast, was associated with an excess risk of these perinatal complications regardless of hormone usage. There was also a suggestion that certain subgroups of women with vaginal bleeding might be at an increased risk of delivering an offspring with congenital malformations.

Female↗
PubMed1982

A longitudinal study of respiratory health in a rural community.

We studied the white residents of Lebanon, Connecticut, a rural community, cross-sectionally in 1972 and a follow-up survey in 1978. In this community, we examined prospectively the growth and decay of lung function and the prevalence, attack, and remission of respiratory symptoms in 1,262 persons. These longitudinal findings were related to sex, age, and smoking habits. Respiratory symptoms and 3 lung function variables were examined: forced expiratory volume in one second (FEV1) and maximal expiratory flow rates at 50 and 25% of vital capacity (Vmax50 and Vmax25). The representativeness of the follow-up population was examined by an extensive analysis of the respondents and nonrespondents based on their cross-sectional characteristics. These analyses did not, in general, reveal any consistent results indicating that a healthier population was followed. The longitudinal data showed that lung growth continued into early adulthood (25 to 34 yr of age) with a leveling off and decline beginning at 35 yr and older. This is in contrast to cross-sectional studies of growth and decay of lung function, which show less growth among the young and more decay among adults. The rates of growth in both males and females were affected by their smoking status, with smokers having less growth and greater decline than nonsmokers. In particular, lung function growth was impaired in young smokers as early as 15 to 24 yr of age, and an actual decline was seen in the females of this age group.

Adolescent↗
PubMed1982

Airway reactivity and exercise in healthy subjects.

The interaction of exercise, methacholine challenge, and beta-adrenergic blockade was investigated in eight healthy subjects. We measured the response to increasing doses of aerosolized methacholine, examining maximum expiratory flow rates. These responses were compared with those obtained on separate days when each methacholine challenge followed submaximal exercise or submaximal exercise in the presence of Beta-blockade. The possible independent effect of increased ventilation (20 +/- 6.7 L/min) was also studied during methacholine challenge. Methacholine-induced bronchospasm was not augmented by exercise alone or by exercise in the presence of beta-blockade, nor was this response significantly altered by hyperventilation during methacholine aerosol challenge. These findings suggest that airway hyperreactivity cannot be induced in healthy subjects by levels of exercise that commonly provoke exercise-induced bronchospasm in asthmatic patients.

Adult↗
PubMed1982

A prospective study of chronic lung disease in cotton textile workers.

A cohort of both active and retired older cotton textile workers was examined prospectively over a 6-year period to establish the nature and extent of chronic lung disease. Respiratory symptoms and lung function were studied in these workers and in a group of similarly aged controls. The cotton textile workers had higher prevalence and attack rates of respiratory symptoms than did controls even with smoking habits taken into account. Chronic bronchitis developed in 16% of all cotton textile workers compared to 1% of controls over the follow-up period (p less than 0.001). The cotton workers suffered a larger loss of lung function over 6 years than did controls. Male workers lost 42 mL/yr of forced expiratory volume in 1 second, although male controls lost only 25 mL/yr (p = 0.001). Similar differences were seen in women, and in both men and women who were nonsmokers. Retired cotton textile workers had more symptoms and disability than active workers. We conclude that chronic lung disease is not only irreversible but may progress even after exposure to cotton dust has ended.

Byssinosis↗
PubMed1982

Cimetidine-theophylline interaction: report of four patients.

Four patients who had experienced a cimetidine-theophylline interaction are reported. All patients displayed decreases in theophylline elimination after the introduction of cimetidine. Clearances approached baseline values when cimetidine was discontinued. Patients on this drug combination should be monitored closely for signs of theophylline toxicity. When indicated, a beta agonist may be a better choice of a bronchodilator for peptic ulcer patients.

Adrenergic beta-Agonists↗
PubMed1981

Does intermittent mandatory ventilation accelerate weaning?

Intermittent mandatory ventilation (IMV) was introduced to facilitate the weaning of patients from mechanical ventilation. The outcome of ventilator management in 116 patients who were treated in the first three months of 1975 was compared retrospectively with that of 135 patients who were treated in the first three months of 1976. All patients who were treated in 1975 received conventional (assisted or controlled) mechanical ventilation. In 1976, seventy-seven patients (57%) were treated with the use of IMV, and 58 (43%) were treated with the use of conventional mechanical ventilation. Sixty-five patients who were treated in 1976 with the use of IMV were matched with patients who were treated in 1975 with the use of conventional ventilation, on the basis of age, sex, race, history of pulmonary disease, smoking history, diagnosis, service, and location of therapy. The average time spent on a ventilator by the IMV patients was 145 hours, whereas the matched control patients spent 142 hours. The length of hospitalization was 36 days for the IMV patients and 30 days for the control patients. These time periods were not significantly different and indicate that IMV did not reduce the length of ventilator management.

Acute Disease↗