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Biomedical subjects

W Reddan

Publications and source records attributed to W Reddan.

10 recordsLinked to original sources
PubMed1987

Physiologic and metabolic response to progressive and prolonged exercise in amyotrophic lateral sclerosis.

Physical work capacity in 35 ALS patients and 6 untrained controls was evaluated during progressive bicycle ergometry. In the ALS patients, maximum oxygen consumption (VO2max) and work capacity (Wmax) drop in relation to the decrease in ALS functional score. However, the oxygen cost (ml O2/kpm) of submaximal exercise was significantly increased. Prolonged submaximal exercise tests in six ALS patients and six matched untrained controls indicated that the exercise-induced increase in plasma free fatty acids, beta-hydroxybutyrate, esterified carnitine, and muscle esterified carnitine was significantly retarded in ALS patients.

3-Hydroxybutyric Acid↗
PubMed1987

Role of muscular exercise in amyotrophic lateral sclerosis.

The general, systemic, and specific neuromuscular adaptation to physical exercise and training in healthy individuals is reviewed with application to individuals with neuromuscular disease in general and ALS in particular. A pilot study utilizing patients with ALS suggests the cardiopulmonary response to acute exercise is similar to normal individuals. However, a case study of a training response suggests the success of neuromuscular adaptation will be dependent upon the degree of motor neuron involvement.

Adult↗
PubMed1984

Epidemiologic study of clinical and physiologic parameters in grain handlers of northern United States.

To study the effects of grain dust exposure, we compared respiratory parameters between 310 grain handlers and 237 city workers of comparable age, height, weight, and smoking habits. Both populations resided and worked in the same geographic area of the United States. Information was obtained by questionnaire, interview, and examination. Pulmonary function tests included FEV1, FVC, FEF25-75, Vmax50, CV, delta N2/L, and DLCO. The prevalence of acute work-related and chronic respiratory symptoms, of auscultatory bronchi, and of airways obstruction (FEV1/FVC less than 0.7) were significantly higher (p less than 0.05) in grain handlers than in control subjects. The mean values of all lung functions except CV, delta N2/L, and DLCO were significantly lower in grain workers than in control subjects. The effects of smoking and grain handling on symptom prevalence and lung functions adjusted for age and height, analyzed by logistic regression model, were highly significant (p values ranged from 0.00001 to 0.5) and independent. The odds of having chronic bronchitis or wheezing at work were, respectively, increased 4.4-fold and 4.8-fold by grain handling and by 2.9-fold and 1.9-fold by smoking. Grain handling increased the odds of having airways obstruction 2.6-fold and smoking increased it 2.7-fold. We conclude that grain handlers have a higher prevalence of chronic bronchitis and other respiratory symptoms than do comparable workers who do not handle grain. The effect of grain dust exposure on symptom prevalence is usually greater than that of smoking. Grain handling has an adverse effect on lung function that is of the same or smaller magnitude than that of smoking.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Acute effects of grain dust exposure during a work shift.

We studied 248 grain handlers and 192 city services workers (control subjects) before and after an 8-h work shift and measured total dust levels using personal samplers. We found that grain workers exposed to a mean total dust level of 3.3 +/- 7.0 mg/m3, when compared with control subjects, had (1) a higher prevalence of work-related respiratory symptoms (p less than 0.05) and significant decrements in forced-expiratory volume in one second (FEV1) and maximal flow rates after exhalation 50 and 75% of forced vital capacity (Vmax50 and Vmax75) during the work shift, and (2) significant differences (p less than 0.05) in preshift/postshift percent changes in forced vital capacity (FVC), Vmax50 and Vmax75. Adjusting for age, height, and smoking habit, grain handling still had a significant negative effect on FVC, Vmax50, and Vmax75. In grain workers, we found a significant (p less than 0.05) negative relationship between total dust levels and the percent change in FVC, Vmax50, and Vmax75 and a positive relationship between dust level and percent change in leukocyte counts. Grain workers' perception of dust level correlated with the measured dust level and the prevalence of symptoms. Occupational exposure to grain dust during a work shift has a dose-related adverse acute respiratory effect regardless of smoking habit, atopic status, or age, and it produces a dose-related leukocyte response at total dust levels below 15 mg/m3.

Acute Disease↗
PubMed1982

Determinants and consequences of ventilatory responses to competitive endurance running.

Pulmonary ventilation and pattern, arterial blood gases, and [H+] were studied in 15 highly trained runners [maximum O2 consumption (VO2 max) 53--82 ml . kg-1 . min-1] during road racing (24 km, n = 5) and 60--70 min of treadmill running (70--75% VO2 max, n = 13). The predominant response throughout prolonged treadmill running and especially road running was a tachypneic, respiratory alkalosis (-5 to -12 Torr PaCO2) that was evident early in the exercise. Time-dependent increases in breathing frequency (10--40%, 6--60 min work), expired ventilation, and dead space ventilation were common in prolonged work; these were especially evident in two subjects even as VO2 fell during road racing under hot humid conditions. The tachypneic hyperventilation was 1) most often accompanied by alkaline [H+]a, 2) associated with time-dependent elevation in rectal temperature (1--1.5 degrees C) and circulating norepinephrine (5--20 x rest), 3) quickly alleviated via hyperoxia after 60--70 min of exercise, and 4) was shown to result from increased running velocity in separate experiments that compared walking vs. running at similar CO2 excretion and [HCO-3]a. In highly trained runners competing under favorable environmental conditions and optional pace selection, we view the net effects of the hyperventilatory response to be truly advantageous, whereby the benefits to pulmonary gas exchange and [H+] regulation outweigh the expense of some inefficiency in ventilatory work and pattern and a departure from steady-state homeostasis.

Adult↗
PubMed1981

Physical activity and calcium modalities for bone mineral increase in aged women.

This study tested the hypothesis that physical activity and/or supplemental calcium (0.75 g/day) and vitamin D (400 IU) would effectively slow bone loss, and /or increase bone mineral content (BMC) in aged females (X = 81) over three years. In vivo BMC and width of the radius was determined by photon absorptiometry at two sites. Four groups were formed: a control, a drug, a physical activity, and a physical activity plus drug. A single tailed t-test was used to compared the slope of the linear regression of 10 data points collected on each subject. The BMC of the control group declined 3.29%, while the physical activity group and drug group demonstrated a 2.29% (p less than .05) increase and a 1.58% (p less than .07) increase respectively, during the study.

Aged↗
PubMed1977

Respiratory abnormalities among grain handlers: a clinical, physiologic, and immunologic study.

A survey of 300 grain elevator workers revealed that 77 per cent complained of eye symptoms; 64 per cent, of nasal symptoms; and 88 per cent, of one or more respiratory symptoms on exposure to airborne grain dust. Symptoms on exposure were independent of age and length of employment. Cough and wheezing on exposure were more common among smokers than nonsmokers (P less than 0.025). Nineteen per cent of the workers had had episodes of grain fever. The prevalence of chronic bronchitis was 37 per cent (42 per cent of smokers and 30 per cent of nonsmokers). Wheezes on auscultation were found in 23 per cent. Measurements of lung ventilatory function, as well as diffusing capacity, correlated significantly with age and smoking habits, but not with length of employment. Thirty-seven per cent of the workers had an abnormal mean forced expiratory flow during the middle half of the forced vital capacity (47 per cent of smokers and 13 per cent of nonsmokers), and 34 per cent had an abnormal maximal expiratory flow after exhalation of 50 per cent of the forced vital capacity (40 per cent of smokers and 13 per cent of nonsmokers), whereas only 13 per cent had an abnormal ratio of 1-sec forced expiratory volume to forced vital capacity. There was no correlation between precipitins to fungi, bacteria, grain, or grain dust antigens and acute or chronic respiratory symptoms, lung function, or grain fever. There was, however, a significant correlation between cutaneous reactivity to grain dust and wheezing on exposure (P less than 0.02). Abnormal flows at low lung volumes were more common among cutaneous reactors to common allergens. We concluded that exposure to airborne grain dust can cause acute inflammatory reaction to the exposed mucosa, and it is highly probable that grain dust contributes and, in some cases, causes chronic airway disease.

Adult↗