Search PubMed⌕ Search

Biomedical subjects

S Freedman

Publications and source records attributed to S Freedman.

At least 73 records · Page 4Linked to original sources

Lung volumes and distensibility, and maximum respiratory pressures in thyroid disease before and after treatment.

Lung volumes, static pressure volume curves of the lung, and maximum respiratory pressures were measured in six patients with thyrotoxicosis and three with myxoedema before and after treatment. After treatment three of the thyrotoxic patients had increases in vital capacity of the same order as previously reported, but in contrast to previous reports, the lung volume changes were not associated with, nor due to, concomitant changes in respiratory muscle performance. Static pulmonary compliance increased in four of the six patients. The initial findings were more in keeping with the presence of pulmonary congestion. Only one of the myxoedematous patients had any significant increase in vital capacity after treatment, and in her case this was clearly attributable to increased inspiratory muscle force.

Aged↗

Comparison of findings among residents on Michigan dairy farms and consumers of produce purchased from these farms.

Consumers who had purchased farm products from both quarantined and nonquarantined farms were examined during the cross-sectional clinical survey of 1,029 Michigan residents. Since PBB had inadvertently contaminated cattle and other farm animals, ingestion of meat, milk, eggs and other farm products was thought to have possibly resulted in significant PBB body burdens in some consumers. Findings were considered in comparison with those made among farm residents. Prevalence of symptoms in consumers of farm products from quarantined farms (CQ) was similar to that found in farmers on quarantined farms (FQ); the prevalence was lower in consumers of products from nonquarantined farms (CNQ). Liver function abnormalities were found with similar prevalence in dairy farmers and consumers. Distribution, mean and median values of PBB serum levels in consumers were found to be similar to those of dairy farmers. These results indicate that significant body burdens of PBB had been accumulated by some consumers of farm products in Michigan and that prevalence of symptoms and liver function abnormalities resembled those found among dairy farm residents.

Biphenyl Compounds↗

Unanticipated prevalence of symptoms among dairy farmers in Michigan and Wisconsin.

Adverse human health effects resulting from exposure to polychlorinated biphenyls (PBBs) were unknown until the accidental contamination of Michigan dairy farm animal feed in 1973-1974. Human exposure resulted from the consumption of contaminated meat, milk, dairy products, and eggs. In November 1976, the Environmental Sciences Laboratory conducted comprehensive examinations of 933 farmers and residents in Mighigan who were likely to have consumed farm products contaminated with PBB. A comparison group of 229 Wisconsin dairy farmers were examined in March 1977 and the same scientific and medical staffs that conducted the Michigan survey were responsible and the same procedures used. A complete history of symptomatology by organ system, including year of first onset, duration, frequency, and severity of each symptom was obtained by a physician on all adults examined. Statistical analysis of the prevalence of symptoms at the time of examination or during the preceding year in the Michigan and Wisconsin populations studied found the Michigan group to have a significantly higher prevalence of skin, neurological and musculoskeletal symptoms. The increase was seen among the younger age groups 16-35 and 36-55. Michigan females had a higher prevalence of neurological symptoms than the Michigan males. The existing differences could not be explained without considering an etiologic role for exposure to PBB.

Adolescent↗

Changes of smoking habits and cough in men smoking cigarettes with 30% NSM tobacco substitute.

The effects of smoking cigarettes with 30% of the tobacco replaced by NSM tobacco substitute, which lowered their tar and nicotine delivery, were studied by comparing them with the effects of conventional cigarettes in a controlled crossover trial lasting 20 months. Chest symptoms, cigarette consumption, and forced expiratory volume in one second (FEV1) were measured each month. Two-hundred men began the trial and 159 completed it. The test cigarettes were acceptable to all but one of the men. In a subsample of 35 men estimates of nicotine intake were obtained from monthly analyses of cigarette stubs. On changing from NSM to control cigarettes six of the 17 men, who were accustomed to low nicotine, kept their nicotine intake down by some change in smoking habit. Before the crossover and this change in smoking habit the men smoking NSM cigarettes had a small but significant reduction of cough. Cigarettes containing 30% NSM and delivering only 1 mg of nicotine are likely to be acceptable to smokers and may reduce coughing. Further trials are needed to confirm these findings and establish what long-term effects such cigarettes may have on smokers' health.

Adult↗

Exercise tests before and after heart valve replacement.

A simple progressive exercise test was performed before and after operation on five subjects undergoing mitral valve replacement and on five subjects undergoing aortic valve replacement. The responses of heart rate and ventilation were related to work rate )kilopond metres/min). The patients were also assessed clinically by the New York Heart Association grading and radiologically before each exercise test. The clinical grading was shown to be a poor guide to observed exercise tolerance, as the improvement noted in symptoms was not matched by the objective measurement of working capacity. Only two patients had normal exercise tolerance after surgery, although six of the ten patients claimed that they had no exertional dyspnoea after operation. The changes in simple ventilatory function tests before and after operation were generally small. We suggest that measurements of exercise tolerance before and after operation should be an essential part of heart valve replacement surgery.

Adult↗

Asthma due to inhaled chemical agents--amprolium hydrochloride.

A man with no previous history of allergy or chest disease developed asthma after exposure to a heavy atmospheric concentration of amprolium hydrochloride which is a constituent of a poultry-food additive. Subsequent experimental exposure produced an immediate asthmatic reaction which was inhibited by sodium cromoglycate.

Aged↗

Changes in lung mechanics during asthma induced by exercise.

Pulmonary and airway mechanics were assessed in seven asthmatic patients in remission, when asthma was induced by exercise and again after spontaneous recovery or bronchodilator treatment. After exercise there was a sustained fall in forced expiratory volume in 1 s (FEV 1.0) in all patients, varying from 30 to 80 percent of the initial value. Total lung capacity (TLC) increased significantly in four of the seven patients. In one of the four patients the increase in TLC was associated with an increase in static transpulmonary pressure at full inflation but in the remaining three patients it was associated with a parallel shift of the pressure-volume curve of the lung without change in its slope. In all patients residual volume increased, regardless of change in TLC; both pressure-volume and maximum expiratory flow-volume curves suggested that widespread airway closure (or virtual closure) occurred at positive transpulmonary pressures when asthma was induced. Loss of lung recoli pressure sometimes contributed to the reduction in maximum expiratory flow but diffuse airway narrowing was probably the dominant abnormality. When air-flow obstruction became more severe the ratio of expiratory to inspiratory time was increased and although expiratory flow limitation was present excessive expiratory pressures were not generated.

Adolescent↗