Biomedical subjects

J S Mandel

Publications and source records attributed to J S Mandel.

At least 91 records · Page 5Linked to original sources

PubMed1993

An update of mortality among chemical workers potentially exposed to the herbicide 2,4-dichlorophenoxyacetic acid and its derivatives.

Four years of additional mortality follow-up through 1986 are reported for a previously studied cohort of 878 chemical workers who were potentially exposed to 2,4-dichlorophenoxyacetic acid (2,4-D) and its derivatives between 1945 and 1983. Observed mortality was compared with expected levels based on death rates of the US population and of 36,804 "unexposed" workers from the same manufacturing location. Non-Hodgkin's lymphoma (NHL) was a particular focus of the study because of a suggested association with 2,4-D exposure in some case-control studies. For the total observation period, the standardized mortality ratios for all causes and for malignant neoplasms were 92 and 91, respectively. Analyses using the internal comparison group yielded virtually identical results. The initial study had found two deaths from NHL, both of which occurred under circumstances (ie, short latency and modest exposure) which made it less plausible that they were related to 2,4-D exposure. No new deaths from NHL were observed in the extended follow-up period and mortality for this cause showed a nonstatistically significant excess (standardized mortality ratio, 196; 95% confidence interval 24 to 708) for the total observation period. Analyses by production area, and by two different measures of exposure, combined with two different approaches to account for latency, did not show patterns suggestive of a causal relationship between exposure to 2,4-D or its derivatives and any particular cause of death.

2,4-Dichlorophenoxyacetic Acid↗

PubMed1992

Selection of controls in case-control studies. I. Principles.

A synthesis of classical and recent thinking on the issues involved in selecting controls for case-control studies is presented in this and two companion papers (S. Wacholder et al. Am J Epidemiol 1992;135:1029-50). In this paper, a theoretical framework for selecting controls in case-control studies is developed. Three principles of comparability are described: 1) study base, that all comparisons be made within the study base; 2) deconfounding, that comparisons of the effects of the levels of exposure on disease risk not be distorted by the effects of other factors; and 3) comparable accuracy, that any errors in measurement of exposure be nondifferential between cases and controls. These principles, if adhered to in a study, can reduce selection, confounding, and information bias, respectively. The principles, however, are constrained by an additional efficiency principle regarding resources and time. Most problems and controversies in control selection reflect trade-offs among these four principles.

Case-Control Studies↗

PubMed1992

Selection of controls in case-control studies. II. Types of controls.

Types of control groups are evaluated using the principles described in paper 1 of the series, "Selection of Controls in Case-Control Studies" (S. Wacholder et al. Am J Epidemiol 1992;135:1019-28). Advantages and disadvantages of population controls, neighborhood controls, hospital or registry controls, medical practice controls, friend controls, and relative controls are considered. Problems with the use of decreased controls and proxy respondents are discussed.

Case-Control Studies↗

PubMed1992

Selection of controls in case-control studies. III. Design options.

Several design options available in the planning stage of case-control studies are examined. Topics covered include matching, control/case ratio, choice of nested case-control or case-cohort design, two-stage sampling, and other methods that can be used for control selection. The effect of potential problems in obtaining comparable accuracy of exposure is also examined. A discussion of the difficulty in meeting the principles of study base, deconfounding, and comparable accuracy (S. Wacholder et al. Am J Epidemiol 1992;135:1019-28) in a single study completes this series of papers.

Bias↗

PubMed1992

A health survey of radiologic technologists.

A health survey of more than 143,000 radiologic technologists is described. The population was identified from the 1982 computerized files of the American Registry of Radiologic Technologists, which was established in 1926. Inactive members were traced to obtain current addresses or death notifications. More than 6000 technologists were reported to have died. For all registrants who were alive when located, a detailed 16-page questionnaire was sent, covering occupational histories, medical conditions, and other personal and lifestyle characteristics. Nonrespondents were contacted by telephone to complete an abbreviated questionnaire. More than 104,000 responses were obtained. The overall response rate was 79%. Most technologists were female (76%), white (93%), and employed for an average of 12 years; 37% attended college, and approximately 50% never smoked cigarettes. Radiation exposure information was sought from employer records and commercial dosimetry companies. Technologists employed for the longest times had the highest estimated cumulative exposures, with approximately 9% with exposures greater than 5 cGy. There was a high correlation between cumulative occupational exposure and personal exposure to medical radiographs, related, in part, to the association of both factors with attained age. It is interesting that 10% of all technologists allowed others to practice taking radiographs on them during their training. Nearly 4% of the respondents reported having some type of cancer, mainly of the skin (1517), breast (665), and cervix (726). Prospective surveys will monitor cancer mortality rates through use of the National Death Index and cancer incidence through periodic mailings of questionnaires. This is the only occupational study of radiation employees who are primarily women and should provide new information on the possible risks associated with relatively low levels of exposure.

Adult↗

PubMed1992

Anti-dsDNA antibodies in laboratory workers handling blood from patients with systemic lupus erythematosus.

The presence of antinuclear antibodies was determined in female laboratory workers with varying degrees of exposure to blood from patients with systemic lupus erythematosus (SLE). Subjects recruited from SLE research laboratories and a membership roster provided by the American Society for Medical Technology were classified according to self-reported frequency of handling blood from patients with SLE into high and low exposure groups. Employment and medical history were obtained by questionnaire from each study subject and their sera were tested for antibodies to double stranded DNA, single stranded DNA, and synthetic polynucleotide poly(dA-dC).poly(dG-dT) by ELISA. Analysis of the results using an independent t test showed the mean optical density for anti-dsDNA was higher in the high exposure group (mean = 0.010) than in the low exposure group (mean = 0.005, p = 0.016). There were no significant differences found between the 2 groups for anti-ssDNA or anti-poly(dA-dC).poly(dG-dT), but the means for both anti-dsDNA and anti-poly(dA-dC).poly(dG-dT) were higher in the laboratory workers than in an unexposed nonlaboratory group of women (p less than 0.001). Our results are provocative for they lend support to the hypothesis that a transmissible agent capable of causing autoantibody formation may exist in blood from patients with SLE.

Adult↗

PubMed1991

Nutrients and pancreatic cancer: a population-based case-control study.

A case-control study was conducted in the Minneapolis-St Paul (Minnesota, United States) area to assess the role of dietary factors in the etiology of pancreatic cancer. Cases were White males aged 40 to 84 whose death certificate listed pancreatic cancer (exocrine only). White male controls were ascertained through random-digit dialing. Family members were interviewed about the subject's dietary usage in the two years prior to death (cases, n = 212) or prior to interview (controls, n = 220). Energy-adjusted, nutrient-intake, risk estimates were calculated. Among all respondents, negative trends were observed for polyunsaturated fat, linoleic acid, vitamin C, and beta-carotene. Positive trends were observed for riboflavin and retinol. Point estimates were, in general, comparable between the analyses of all respondents and spouse-only respondents. The nutrients associated with a decreased risk for pancreatic cancer occur primarily in vegetables and fruits, of which the consumption of cruciferous and beta-carotene-rich vegetables and citrus fruits provided the greatest reduction in risk.

Adult↗

PubMed1990

A clinical trial of beta carotene to prevent basal-cell and squamous-cell cancers of the skin. The Skin Cancer Prevention Study Group.

BACKGROUND: Beta carotene has been associated with a decreased risk of human cancer in many studies employing dietary questionnaires or blood measurements, and it has had protective effects in some animal models of carcinogenesis. METHODS: We tested the possible cancer-preventing effects of beta carotene by randomly assigning 1805 patients who had had a recent nonmelanoma skin cancer to receive either 50 mg of beta carotene or placebo per day and by conducting annual skin examinations to determine the occurrence of new nonmelanoma skin cancer. RESULTS: Adherence to the prescribed treatment was good, and after one year the actively treated group's median plasma beta carotene level (3021 nmol per liter) was much higher than that of the control group (354 nmol per liter). After five years of follow-up, however, there was no difference between the groups in the rate of occurrence of the first new nonmelanoma skin cancer (relative rate, 1.05; 95 percent confidence interval, 0.91 to 1.22). In subgroup analyses, active treatment showed no efficacy either in the patients whose initial plasma beta carotene level was in the lowest quartile or in those who currently smoked. There was also no significant difference between treated and control groups in the mean number of new nonmelanoma skin cancers per patient-year. CONCLUSIONS: In persons with a previous nonmelanoma skin cancer, treatment with beta carotene does not reduce the occurrence of new skin cancers over a five-year period of treatment and observation.

Aged↗

PubMed1990

Occupation and industry on death certificates of long-term chemical workers: concordance with work history records.

This study evaluated the concordance between occupation and industry listed on death certificates with actual work history information for a group (n = 5,882) of long-term (10 years or more) workers at a chemical company. Match rates were calculated as the percent of death certificate occupation and company entries that were confirmed by work history data using 3-digit 1980 U.S. Census Bureau group codes. The concordance rate for industry differed by employment status at death: employed, 94.9%; inactive, 30.8%; and retired, 91.1%. Concordance on occupation was analyzed for employed (n = 467) and retired (n = 932) subjects who had computerized work histories (randomly done prior to the study) and who had matched on the company on the death certificate. Concordance ranged from 0 to 50% for the first job, to 50 to 70% for the last job, longest job, and longest job in the last 10 years of company employment. The most consistent predictor of concordance was job duration. Misclassification was reviewed by occupational category. Results from this and other investigations lead to the inevitable conclusion that usual occupation data from death certificates are grossly inadequate for studies of occupational risks.

Aged↗

PubMed1990

Comparison of next-of-kin with self-respondents regarding questions on cigarette, coffee, and alcohol consumption.

Using the same questionnaire, personnel, and field procedures, we conducted interviews in 1985 with the next-of-kin of 108 deceased study subjects, and with 197 surviving subjects who had been interviewed earlier in a 1980 case-control study. Concordance in response between the two interviews for cigarette smoking, coffee drinking, and alcoholic beverage intake was high, generally 90% or above. Next-of-kin, particularly spouses, provided information as reliable as the self-informants for cigarette smoking and coffee consumption, but showed a somewhat higher discrepancy rate for alcohol drinking. Thus, surrogates, especially spouses, appear to be an accurate source of information in epidemiologic investigations.

Adult↗

PubMed1989

Organophosphate exposure inhibits non-specific esterase staining in human blood monocytes.

The objective of this study was to investigate the association between exposure to triaryl phosphate and monocyte nonspecific esterase staining activity in workers from a plant in Nitro, West Virginia. A cross-sectional study design was used to identify the exposed plant employees, and both a plant and a general population group. In addition to completing a questionnaire for each participant, 30 cc of blood were drawn and analyzed using four techniques, two morphological and two enzymatic. These procedures included a Technicon D-90 autoanalyzer, a Technicon H-6000 autoanalyzer, a manual enzymatic using alpha naphthyl butyrate, and a manual morphologic using Wright-Giesma stain. The results showed a decrease in nonspecific esterase staining with the Technicon D-90. No significant effect on monocyte numbers or esterase positivity was found with the other three techniques.

Adult↗

PubMed1989

Minnesota highway maintenance worker cohort mortality study: methods and noncancer mortality.

In 1984, the Minnesota Department of Health (MDH) began a cohort mortality study of 4,849 workers to follow up concerns with the health and safety of highway maintenance workers (HMWs). A total of 1,530 deaths had occurred, resulting in a standardized mortality ratio (SMR) of 91 (p less than .01) and an all cancer SMR of 84 (p less than .01). There was a significant elevation in the SMR for chronic renal failure among long-term rural workers (SMR = 676, p less than .05). The SMR was also elevated for transportation injuries. The latter SMR was highest among short-term urban workers (SMR = 280, p less than .01). In addition, the SMR for transportation-related injury deaths tended to increase the later the decade of starting work. The SMRs were 137, 259, 502, and 2,145 for urban workers starting work in the decades 1945-1954, 1955-1964, 1965-1974, and 1975-1984, respectively. This study demonstrates the possible adverse health effects of highway maintenance work and the need to comprehensively evaluate injury mortality among selected occupational cohorts.

Accidents, Traffic↗

PubMed1989

Minnesota Highway Maintenance Worker Study: cancer mortality.

Highway maintenance workers (HMWs) have been exposed to a broad range of potentially toxic substances, including diesel fuels and exhaust, asphalts and tars, herbicides, gasoline, polynuclear aromatic hydrocarbons, benzene, and lead. The number of current and former state, county, and municipal HMWs in the United States exceeds 500,000, yet the health risks of this occupation had never been studied. To fill this void and to respond to the public perception that Minnesota HMWs were at high risk of developing leukemia, an occupational cohort mortality study was conducted of Minnesota HMWs employed between 1945 and 1984. Leukemia mortality in HMWs with 30-39 years of work (standardized mortality ratio [SMR] = 425; 95% confidence interval [CI] = 171-876) and urologic cancer mortality in HMWs with 40-49 year latency (SMR = 292; CI = 117-602) were significantly elevated. The extent to which these and other findings were directly related to work exposures is unknown. Further investigations to resolve the significance of the risks associated with the HMW occupation are currently underway.

Cohort Studies↗

PubMed1989

Sensitivity, specificity, and positive predictivity of the Hemoccult test in screening for colorectal cancers. The University of Minnesota's Colon Cancer Control Study.

Data are presented on the sensitivity, specificity, and positive predictivity of the Hemoccult test based on the experience of the Minnesota Colon Cancer Control Study, a randomized clinical trial to determine whether the use of the Hemoccult test can reduce mortality from colorectal cancer. Rehydrating the slides with a drop of water before processing resulted in an increase in positivity (2.4% to 9.8%), and sensitivity (80.8% to 92.2%) but a decrease in specificity (97.7% to 90.4%) and positive predictivity (5.6% to 2.2%). The effects of age and sex were also evaluated. The test was less specific for men than women (p = 0.03). Specificity was highest for those less than 60 yr of age and decreased with increasing age (p = 0.05). The positive predictivity increased with age from 1.6% for those under 60 yr to 3.6% for those over 70 yr (p = 0.0004).

Age Factors↗

PubMed1989

The Skin Cancer Prevention Study: design of a clinical trial of beta-carotene among persons at high risk for nonmelanoma skin cancer.

We describe a randomized clinical trial of oral beta-carotene (50 mg/day) for preventing nonmelanoma skin cancer. It is a multicenter study conducted at sites in California, Minnesota, and New Hampshire. This report describes the design of the study, baseline characteristics of the 1805 randomized patients, changes in their plasma beta-carotene and retinol levels after 1 year of treatment, and plans for statistical analyses. Important features of this study are (1) a high proportion of potential subjects were found to be ineligible or chose not to enter the study, (2) the study agent is readily available over the counter and in common foods, and (3) nonmelanoma skin cancer is a relatively minor health concern for most patients. These considerations necessitated intensive efforts to encourage compliance with the study regimen. There are also some unusual statistical features of the study. One is that the study outcome is routinely assessed only at annual examinations, so the precise time of failure cannot be identified. Also, a secondary goal of the study is to determine whether beta-carotene decreases the average number of new skin cancers per patient per year, and there are no established statistical methods for analysis of data in this situation. Alternative approaches to the analysis are discussed.

Adult↗

PubMed1989

A case-control study of pancreatic cancer and cigarettes, alcohol, coffee and diet.

A pancreatic cancer case-control study was conducted in the Minneapolis-St. Paul area. Family members were interviewed about the subject's usage of cigarettes, alcohol, coffee, and other dietary factors in the two years prior to death (cases, n = 212) or prior to interview (controls, n = 220). The adjusted odds ratio for two packs or more of cigarettes per day was 3.92 (95% CI = 1.18, 13.01) and four or more drinks per day OR 2.69 (95% CI = 1.00, 7.27). Coffee was not a risk factor (seven cups or more per day; OR 0.58 (95% CI = 0.27, 1.27). A positive trend was observed for beef and pork consumption, and a negative trend from cruciferous vegetables.

Adult↗

PubMed1988

Reproductive outcomes in scoliosis patients.

In a retrospective cohort study of 1,409 persons diagnosed with scoliosis between 1927 and 1965 in Minneapolis and St. Paul, Minnesota, mailed questionnaires were obtained for 846 white women. Six hundred and eight (72%) of these women had ever been pregnant, and they reported a total of 1,733 pregnancies and 1,413 livebirths. Adverse outcomes among the pregnancies and livebirths of the 608 women were reported, including spontaneous abortion, stillbirth, low birth weight, prematurity, congenital anomalies, and complications of pregnancy or delivery. Rates of these events for the scoliosis patients were compared with corresponding expected rates. Comparison of the overall rates suggested that the scoliosis patients had more premature births than expected, but their rates of other adverse reproductive events did not differ from expected.

Adult↗

PubMed1988

Projection of asbestos related diseases in the United States, 1985-2009. I. Cancer.

Projections of asbestos associated cancer mortality in the United States during the 25 year period 1985-2009 were made based on previously published estimates. These estimates were reviewed for malignant mesothelioma, lung cancer, and gastrointestinal cancers. Particular attention was given to the assumptions used in the original derivation of the estimates. For malignant mesothelioma mortality, previous estimates ranged from 15,500 to 300,000. Using recently published data from the Surveillance, Epidemiology, and End Results project, coupled with the previously published estimates, projected asbestos related malignant mesothelioma mortality in the United States for the period 1985-2009 was estimated to be 21,500. For lung cancer, previous estimates were reviewed, particularly with regard to the ratio of deaths from lung cancer to deaths from malignant mesothelioma. Using these ratios, a range of projected deaths was established and a median of those estimates used as a project, which was 76,700 such deaths in the United States between 1985 and 2009. Gastrointestinal cancer mortality has been projected by only three investigators. A median of those estimates (33,000) was used. In conclusion it is estimated that 131,200 deaths from asbestos associated cancer will occur in the United States between 1985 and 2009.

Asbestos↗