Biomedical subjects
J M Peters
Publications and source records attributed to J M Peters.
The Kepone episode: another warning.
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Teaching occupational health to physicians.
A comprehensive training program for physicians interested in occupational health is presented. The objectives are to prepare students to identify and prevent occupational disease, with an emphasis on the development of a public health perspective. Seven content areas are described: epidemiology and biostatistics, toxicology, industrial hygiene, safety and ergonomics, policy issues, administration, and clinical aspects. These are organized in a matrix to provide appropriate levels of training for medical students, resident physicians, and general practioners as well as physicians seeking specialty training.
Mortality among Boston firefighters, 1915--1975.
Although the nature of firefighting involves particular health hazards, previous mortality and morbidity studies of firemen have produced inconsistent evidence for an increased risk of mortality from cardiovascular disease, respiratory disease, cancer and accidents. Mortality experience since 1915 has been examined in 5655 Boston firefighters, comprising all male members of the city fire department with three or more years of service. The observed cause of death as stated on the death certificates of 2470 deceased firefighters has been compared with the numbers expected based on rates for the male population of Massachusetts and of the United States of America. Among all firefighters, deaths from all causes were 91% of expected. The standardised mortality ratio (SMR) was markedly reduced (less than 50) for infectious disease, diabetes, rheumatic heart disease, chronic nephritis, blood diseases and suicide. The SMR was 86 for cardiovascular deaths, 83 for neoplastic deaths, and 93 for respiratory deaths. The SMR for accidents was 135 for active firefighters. The results suggest that the survival experience of firefighters is strongly influenced by strict entry selection procedures, ethnic derivation, and sociocultural attributes of membership. While excessive morbidity has been demonstrated in firefighters, there does not appear to be a strong association between occupation and cause-specific mortality.
Oat cell lung cancer in selected occupations: a case-control study.
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Apparent effect of an azodicarbonamide on the lungs. A preliminary report.
This preliminary study calls attention to the possible pulmonary reactivity of inhaled finely ground azodicarbonamide to which small numbers of workers may be exposed. The conditions in this particular plant involving significant exposure to respirable dust in the mg/m3 range may occur in other plants handling these fine powders. Engineering controls are indicated to protect the workers. We hope that this report will stimulate more detailed studies to validate or refute these observations.
Chronic pulmonary function loss from exposure to toluene diisocyanate.
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Pulmonary function in granite dust exposure: a four-year follow-up.
Pulmonary function studies were performed on 974 workers in Vermont granite sheds in 1974. Of these subjects, 668 had been studied 4 years earlier and had remained in jobs in which their exposure to granite dust had not changed based on dust concentrations measured during 1970. The yearly decrement in pulmonary function observed in the 668 granite shed workers was excessive (0.07 to 0.08 liter per year for forced vital capacity and 0.05 to 0.07 liter per year for forced expiratory volume in 1 sec). This exceeded the expected decrement derived from several other occupational and population groups. Studies from this laboratory and published cross-sectional and longitudinal data consistently indicate a decrement of no more than 0.03 to 0.04 liter per year in both forced vital capacity and forced expiratory volume in 1 sec. The observed decrements were independent of exposure groups and not accounted for by cigarette smoking. In 528 additional granite shed workers, decrements in ventilatory capacity had been measured for one, 2, or 3 years and were consistently of the same order of magnitude. Dust concentrations within defined jobs and between granite sheds showed great variability. Despite this, a suggestive relationship between exposure and decrement in ventilatory function was demonstrated at the end of 2 years; however, at the end of 4 years the relationship could no longer be shown with these exposure groupings. The difficulty in characterizing individual dust exposures and projecting dust concentrations for several years is considered to account for the absence of a dose-response relationship at the 4-year follow-up. The results of this study suggest that our previous estimates of annual deterioration in ventilatory capacity attributable to work in granite sheds are underestimates. We conclude that present dust concentrations in Vermont granite sheds cause excessive deterioration of lung capacity. To prevent these effects, dust concentrations must be lowered.
Pulmonary impairment from chronic exposure to sulfur dioxide in a smelter.
The pulmonary function of 113 copper smelter workers was measured in 1973 and again in 1974 to asses the effects of chronic exposure to sulfur dioxide. Respiratory symptoms, smoking history, occupational history, and pulmonary function as measured by forced vital capacity and 1-sec forced expiratory volume were recorded. Exposures to sulfur dioxide, respirable particulates, sulfates, and copper were sampled at intervals throughout the year by personal monitoring. Exposure to 1.0 to 2.5 ppm of sulfur dioxide was associated with excessive loss of 1-sec forced expiratory volume during the year and an increase in respiratory symptoms, after controlling for smoking. No significant interaction between sulfur dioxide and concurrent exposure to respirable particulates on pulmonary function was found. Workers with 1-sec forced expiratory volume below normal on initial measurements (based on their age and height) showed evidence of even greater losses of pulmonary function related to sulfur dioxide exposure.
Mammotrophic activity in rat amniotic fluid.
Mammotrophic activity was present in rat amniotic fluid collected on days 13, 15 and 19 of pregnancy. The mammotrophic activity in the fluid was equivalent to that in the maternal serum on day 15, but is was lower on day 19. The effect of tha amniotic fluid was similar to that of human placental lactogen on the rat mammary gland in vitro. The prolactin concentration in the amniotic fluid was low (approximately 1 ng/ml).
The importance of insulin, cortisol, progesterone and prolactin for the mammotrophic effect of pregnant rat serum.
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The effect of a placental mammotrophin and cortisol on the ultrastructure of rat mammary gland in organ culture.
Mammary gland explants obtained from 13 days pregnant rats were cultured for 3, 6 and 9 days in the presence of serum of either virgin rats or 13 days pregnant rats. Insulin was added alone or in combination with cortisol. The way these different forms of treatment affected the ultrastructure was studied. With virgin rat serum plus insulin alone the mammary gland regressed to a lower state of development comparable to that of the virgin rat in vivo. When virgin rat serum was replaced by 13 days pregnant rat serum--which contains rat chorionic mammotrophin--the initial development was maintained, but synthesis of secretory products ceased. When cortisol was added to the virgin rat serum plus insulin, cortisol maintained the differentiated state originally present. Even some secretory activity was induced, but at a minimal level. With cortisol added to the pregnant rat serum plus insulin, the explants were stimulated to synthetize the extrude secretion products.
Daily relaxation response breaks in a working population: II. Effects on blood pressure.
A 12-week randomized experiment investigated the effects of daily relaxation breaks on office workers with "normal" blood pressure. Blood pressures of 126 volunteers from the corporate offices of a manufacturing firm were measured biweekly. After four weeks of baseline monitoring,volunteers were divided randomly into three groups: Group A was taught a technique for producing the relaxation response; Group B was "taught" to sit quietly; and Group C was taught nothing. Groups A and B were asked to take two 15-minute relaxation breaks daily. During the baseline period, mean systolic blood pressures (SBP) were 119.7, 118.4, and 114.2 for Groups A, B and C respectively; mean diastolic pressures (DBP) were 78.7 and 75.7 Between the first and last measurements, mean changes in SBP were -11.6, -6.5, and +0.4 mm Hg in Groups A, B, and C; mean DBP decreased by 7.9, 3.1, and 0.3. Between the fourweek baseline period and last four weeks of the experimental period, mean SBP and DBP, mean changes in Group A were significantly greater than those in Group B (p < 0.05) and in Group C (p < 0.001). The same pattern of changes among the three groups was exhibited by both sexes, all ages, and at all initial levels of blood pressure. However, in general, within Group A, the higher the initial blood pressure, the greater the decrease. (Am. J. Public Health 67;954-959, 1977)
Lung function in fire fighters, I: a three year follow-up of active subjects.
From a cohort of 1,768 Boston fire fighters studied initially in 1970, pulmonary function measurements were repeated on 1, 146 active subjects in 1974. The mean time between examinations was 3.4 years. The data on 1,430 subjects after one year of follow-up had indicated excessive decrements in levels of forced vital capacity and one-second forced expiratory bolume which were related to the frequency of fire exposure. The annual decline over three years was less than that observed over one year and could not be related to the number of fires fought or to other indices of acute fire exposure. Selection factors within the fire department appear to be important in protecting fire fighter from continued loss ventilatory capacity.
Release of mammotrophic activity by the rat placenta.
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Occupational disease in the rubber industry.
We have studied mortality patterns in a large cohort of rubber workers. We have examined workers exposed to curing fumes, processing dusts, and industrial talc and have begun to evaluate exposures of these workers in detail. Gastrointestinal (especially stomach) cancer appears in excess in processing workers. Lung cancer is excessive in curing workers. Leukemia is increased generally. All three groups studied for respiratory disease have an increase in disease prevalence which is related to intensity and duration of exposure. Since both an increase in stomach cancer and respiratory disease is seen in processing workers, exposures in this area must be controlled. Since both lung cancer and chronic respiratory disease is excessive in curing rooms, this exposure must be controlled. The leukemia risk is probably related to solvents. Whether this is all explainable by past benzene exposure is unknown. Further studies are planned to refine our knowledge concerning these risks so that occupational disease in the rubber industry can be prevented.
Mammotrophic activity in rat serum during the oestrous cycle, pregnancy and lactation.
The mammotrophic activity of various serum samples was assessed on the mammary gland of pregnant rats, in organ culture. Insulin was added to the medium. Serum samples from virgin rats showed little activity, and variation in mammotrophic activity during the oestrous cycle was slight. During pregnancy a significant increase in proliferative activity was not seen during the first week, but around day 8-9 mammotrophic activity increased sharply. The activity showed maxima around days 12 and 19. A decrease in the activity between these maxima was not consistently observed. Mammotrophic activity was still present in sera collected during parturition, and 30 min after parturition. It had disappeared completely within 24 h. The mammotrophic factor detectable by organ culture in the serum of pregnant rats could be rat chorionic mammotrophin. Activity in the serum on day 0 and 1 of lactation was comparable to that of virgin rats, but some activity appeared on day 2. High actvities were foound frequently around day 4 to 6 of lactation. On other days the activity showed fluctuations without a definite pattern. Litter size was of minor importance but the combination of a larger litter size and fasting-overnight seemed to suppress the presence of mammotrophic activity in the serum. Nursing was important: after weaning the activity has disappeared, while renewed nursing after weaning resulted in the appearance of high levels of activity. The mitotic activity obtained with lactating rat serum in the culture was suppressed by addition of rabbit anti-rat prolactin serum to the medium. This suggests that the main mammotrophic factor detectable by organ culture in the serum of lactating rats, is prolactin.
Influence of the foetus, placenta and ovary on the mammotrophic activity of pregnant rat serum.
Serum mammotrophic activity was assayed using an organ culture technique with histological endpoints. Using sera of 13 days pregnant rats with 1 to 18 conceptuses, activity was detectable even in the presence of 1 conceptus, but the activity with 1-4 conceptus(es) tended to be less than with 6-18. Serum of rats with 1-3 conceptus(es) was approximately 2-4 times less active than serum of rats with 14 conceptuses. Removal of the conceptuses on day 15 caused loss of mammotrophic activity of the serum, tested 4 days later. When the foetuses, the ovaries or both the foetuses and ovaries were removed on day 15 of pregnancy, mammotrophic activity was present in the serum collected 4 days later. Differences in activity between the treated groups were small. The mammotrophic activity was comparable to the activity of serum of untreated 15 days pregnant rats or 19 days sham-operated pregnant rats. Explanted single fragments of a 19 days pregnant rat placenta released activity into the medium. The placenta retained this capicity even when the foetus had been removed 4 days previously.