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Biomedical subjects

W C Cooper

Publications and source records attributed to W C Cooper.

12 recordsLinked to original sources
PubMed1979

Chrysotile asbestos in a California recreational area.

Dustfall along roads and trails being used recreationally in the Clear Creek area of San Benito County, California, located in the New Idria serpentinite, was found to be 90 percent or more chrysotile asbestos. Personal samplers worn by motorcyclists using one of the trails showed concentrations of airborne fibers ranging from 0.3 to 5.3 fibers per milliliter, according to methods prescribed for monitoring occupational exposures. The present workplace standard for brief exposures to asbestos is 10 fibers per milliliter; 5 fibers per milliliter is the proposed standard. The average total dust concentration estimated from personal samplers was approximately 20 milligrams per cubic meter of roughly 90 percent chrysotile. To our knowledge, this is the first demonstration of asbestos exposures of this magnitude, in size ranges known to be pathogenic, resulting from natural deposits not associated with mining, milling, or industrial use.

Air Pollutants↗
PubMed1979

The surgical management of the lid changes of Graves' disease.

There are three areas of surgical intervention available to patients with the eye changes of Graves' disease-lids, extraocular muscles, and orbital decompression. The lid changes may be managed by lateral tarsorrhaphy, levator tenotomy, recession of the levator with or without graft, "tenotomy" of the retractors of the lower lid, or recession with graft. The success of these procedures is dependent on proper patient selection and surgical execution, and when these are achieved, definite benefits result.

Cartilage↗
PubMed1976

Pulmonary function in perlite workers.

Pulmonary function was studied in 117 men employed in three plants engaged in the mining and processing of perlite. Of these, 38 had been employed for ten years or more; 18 for 15 years or more and four men for 20 years or more. Review of chest films confirmed previous studies which showed no changes indicative of pneumoconiosis. Measurement of forced vital capacity (FVC) by Jones Pulmonor and by Collins 9-liter spirometer did not show reductions correlated with length of exposure, after effects of cigarette smoking had been taken into account. There was instead a slight increase in FVC associated with years in the perlite industry. The distribution of individuals with FVC below 80% of predicted also showed no association with duration of perlite exposure. Although there were slight reductions in forced expiratory volume in one second (FEV1) and in FEV1/FVC% which were associated with years in the perlite industry and which could not be explained by cigarette smoking, these reductions were not statistically significant. In summary, the population of men available for study in the major perlite-producing area of the United States, who have worked for periods up to 23 years, showed no evidence of pneumoconiosis by chest radiography or by measurement of forced vital capacity. Nevertheless, continued control of dust to ensure exposures below nuisance dust levels is essential. Medical surveillance should also continue with records being retained for periodic reevaluation.

Adult↗
PubMed1976

Cancer mortality patterns in the lead industry.

The mortality of 7,032 men employed for one or more years in lead production facilities ("smelters") or battery plants was observed over a 23-year period, 1947-1970. There were 1,267 certified deaths. Lead absorption in many members of the cohort was known to have been greatly in excess of accepted standards. The standardized mortality ratio (SMR) for all causes was 107 for smelter workers and 99 for battery plant workers. Deaths from malignant neoplasms were somewhat elevated in both groups, the SMR being 133 for smelter workers and 111 for battery plants. The excesses arose largely from tumors of the digestive organs and the respiratory system. Only three deaths are attributed to malignant renal tumors and seven to tumors of the central nervous system. The latter findings were of interest in view of the experimental production of renal tumors in rats and mice by the injection or oral administration of very large doses of lead salts, and the report by one group of investigators of gliomas in rats fed lead subacetate. Studies are continuing to characterize more fully the exposure of the above lead workers to substances other than lead. Additional follow-up of the cohort is also contemplated.

Carcinogens, Environmental↗
PubMed1976

Nutritional deficiency, immunologic function, and disease.

Several experiments conducted by our group over a period of 6 years have shown that nutritional stress, especially protein and/or calorie deprivation, leads to many, often dramatic, changes in the immune responses of mice, rats, and guinea pigs. Chronic protein deprivation (CPD) has been shown to create an enhancing effect on the cell-mediated immune responses of these animals. Humoral responses under CPD conditions were most often found to be depressed, but sometimes were unaffected, depending on the nature of the antigen employed. Chronic protein deprivation, consistent with the pattern just mentioned, improved tumor immunity by depressing production of B-cell blocking factors, and, in at least one instance, resistance to development of mammary adenocarcinoma in C3H mice was associated with evidence of increased numbers of T suppressor cells. Profound nutritional deficits (less than 5% protein per total daily food intake) depressed both cellular and humoral immunity. Early, though temporary, protein deprivation caused a long-term depression of both cellular and humoral immunity also, with the humoral component being the first to recover. Manipulation of protein and calories was found to have a profound effect on certain autoimmune conditions. Diets high in fat and low in protein favored reproduction but shortened the life of NZB mice, whereas diets high in protein and low in fat inhibited development of autoimmunity and prolonged life. Chronic moderate protein restriction permitted NZB mice to maintain their normally waning immunologic functions much longer than mice fed a normal protein intake. Further, the low-protein diet was associated with a delay in development of manifestations of autoimmunity. Decreasing dietary calories by a reduction of fats, carbohydrates, and proteins more than doubled the average life span of (NZB X NZW)F1 mice, a strain prone to early death from autoimmune disease. Histopathologic studies using immunofluorescent microscopy revealed that the development of the renal lesions caused by the deposition of antigen-antibody complexes, which is so characteristic of these mice, was markedly delayed.

Anemia, Hemolytic↗
PubMed1975

Mortality of lead workers.

The mortality of 7,032 men employed for one or more years in lead production facilities or battery plants was followed over a 23-year period, 1947 to 70. Lead absorption in many of these men was greatly in excess of currently accepted standards based upon urinary and blood lead concentrations available for a portion of the group. There were 1356 deaths reported; death certificates were obtained for 1267. The standardized mortality ratio (SMR) for all causes was 107 for smelter workers and 99 for battery plant workers. Deaths from neoplasms were in slight excess in smelters, but not significantly increased in battery plants. There were no excess deaths from kidney tumors. The SMR for cardiovascular-renal disease was 96 for smelter workers and 101 for battery plant workers, i.e. roughly the same as for the general population, but not as good as would be expected in a population that had been employed. There was definitely no excess in deaths from either stroke or hypertensive heart disease. However, deaths classified as "other hypertensive disease" and "unspecified nephritis or renal sclerosis" were higher than expected. The actual numbers of deaths in these last-named categories combined (41 where 19.5 were expected) represented about 3% of all certified deaths. The life expectancy of lead workers was calculated to be approximately the same as that of all U.S. males. Considering the high levels of exposure in this population of workers and the small deviations from expected mortality, one can be optimistic in predicting no detectable effect on the mortality of male adults from occupational exposures to lead controlled in conformity to currently recommended environmental and biologic standards.

Cardiovascular Diseases↗
PubMed1975

The effects of protein deprivation on cell-mediated immunity.

The effect of protein insufficiency on immune responsiveness was investigated in inbred mice fed isocaloric diets low and normal in protein. Mice were tested for aberrations of cell-mediated and humoral immunities. Protein insufficiency enhances cell-mediated immunity while depressing or not affecting humoral immunity. Cell-mediated immunity was enhanced in testing: allogeneic skin graft rejection, spleen cell responsiveness to phytohemagglutinin, the graft-vs-host reaction, macrophage function, and resistance to viral and bacterial infections.

Animals↗
PubMed1975

Radiographic survey of perlite workers.

Chest roentgenograms of 240 perlite workers employed for 1 to 23 years in the industry, showed no evidence of pneumoconiosis associated with perlite exposures. One individual, found to have simple pneumoconiosis, and one found to have complicated pneumoconiosis, had formerly been diatomaceous earth workers. Since only 28 of the men had been in the industry over 15 years and only seven for 20 years or more, continued surveillance is essential to make sure that there are no effects with more prolonged exposures. Studies of pulmonary function of the individuals who have had relatively long exposures are needed to supplement radiographic evidence.

Aluminum↗
PubMedDate not supplied

Bulk laxative efficacy of a psyllium seed hydrocolloid and of a mixture of cellulose and pectin.

The cellulose/pectin combination (C/P) investigated in this study is as efficacious as a psyllium seed product widely used as a bulk laxative. Because of its physical characteristics (whiteness, lack of flavor and odor, lack of gelling upon standing), it is easy to use as a component of baked foods, sauces, drinks, stews, and in other recipes. Given its fecal bulking equivalence to the popular psyllium-based products, C/P offers advantages to the patient who takes a bulking agent regularly because of the wide choice of methods of consumption, ensuring better compliance over long periods of time. This cellulose/pectin combination appears to be a viable alternative to the limited choice presently available to the bulk laxative user and could also be used as a plant fiber supplement whenever this is desirable.

Adult↗