Search PubMed⌕ Search

Biomedical subjects

L W Pickle

Publications and source records attributed to L W Pickle.

63 records · Page 4Linked to original sources
PubMed1980

Pancreatic cancer mortality in Louisiana.

As a preliminary step in the investigation of high pancreas-cancer mortality among White males in a cluster of Louisiana parishes, we examined 876 pairs of certificates of death which occurred in this area during 1960--75. The pancreas-cancer death records were matched to controls by age, race, sex, year of death, and parish of residence. The odds ratios were increased about two-fold for workers in the oil refining and paper manufacturing industries, and slight elevations were seen among residents near refineries and food processing plants. Despite the limited residential and occupational information available on death certificates, this study suggests leads to environmental factors that can be further investigated by a case-control interview study in Louisiana.

Black or African American↗
PubMed1979

Sister chromatid exchanges and chromosomes in chronic myelogenous leukemia and cancer families.

Spontaneous sister chromatid exchanges and banded karyotypes were studied in blood lymphocytes from 96 individuals: seven patients with chronic myelogenous leukemia, 15 normal controls, and five "cancer families" comprising 12 cancer patients, 40 tumor-free blood relatives and 22 spouses. The families had: malignant melanoma; Epstein-Barr virus-associated malignancies and a birth defect syndrome; non-Hodgkin lymphoma and diverse carcinomas; Hodgkin's lymphoma and adenocarcinomas; and acute myelogenous leukemia. In addition to the Philadelphia chromosome in chronic myelogenous leukemia patients, karyotypic abnormalities, especially breaks and fragments, were found in 29% of cancer family members, but were inconsistent and usually attributable to radiotherapy. Mean sister chromatid exchange values were normal in chronic myelogenous leukemia, but low (by t-test) in tumor patients and their blood relatives in cancer-prone families. In tumor patients, mean sister chromatid exchange levels fell as age increased. After adjusting for this age effect, no significant differences remained among groups. In patients at high risk of cancer (because they have chronic myelogenous leukemia or a strong family history of cancer), spontaneous sister chromatid exchange rates were not a marker of cancer risk.

Adenocarcinoma↗
PubMed1979

Lung cancer in Louisiana: death certificate analysis.

In a search for etiologic clues, a review was made of death certificates of residents in a cluster of Louisiana parishes, mainly in the southern part of the state, where lung cancer mortality was high. A comparison of the statements on occupation for 3,327 patients with lung cancer and those of 3,327 controls (matched by sex, race, age, and parish of residence) during 1960-75 revealed an approximately twofold excess risk associated with transportation equipment manufacture, mainly shipbuilding, and the fishing industry. Smaller elevations of lung cancer risk were found among older men who had been employed in petroleum exploration and production and among male and female residents of towns where the petroleum industry was a major employer. In addition, Acadian ancestry was associated with a higher risk of lung cancer among older male and female residents.

Death Certificates↗
PubMedDate not supplied

Exploring spatio-temporal patterns of mortality using mixed effects models.

A linear mixed effects (LME) model previously used for a spatial analysis of mortality data for a single time period is extended to include time trends and spatio-temporal interactions. This model includes functions of age and time period that can account for increasing and decreasing death rates over time and age, and a change-point of rates at a predetermined age. A geographic hierarchy is included that provides both regional and small area age-specific rate estimates, stabilizing rates based on small numbers of deaths by sharing information within a region. The proposed log-linear analysis of rates allows the use of commercially available software for parameter estimation, and provides an estimator of overdispersion directly as the residual variance. Because of concerns about the accuracy of small area rate estimates when there are many instances of no observed deaths, we consider potential sources of error, focusing particularly on the similarity of likelihood inferences using the LME model for rates as compared to an exact Poisson-normal mixed effects model for counts. The proposed LME model is applied to breast cancer deaths which occurred among white women during 1979-1996. For this example, application of diagnostics for multiparameter likelihood comparisons suggests a restriction of age to a minimum of either 25 or 35, depending on whether small area rate estimates are required. Investigation into a convergence problem led to the discovery that the changes in breast cancer geographic patterns over time are related more to urbanization than to region, as previously thought. Published in 2000 by John Wiley & Sons, Ltd.

Adolescent↗
PubMedDate not supplied

Effects of the choice of age-adjustment method on maps of death rates.

Maps of morbidity or mortality rates, whether considered individually or as a layer in a geographic information system application, invite multiple comparisons of area rates. However, comparisons of rates across different populations require standardization of the age-specific rates to account for differences in population age structures. The indirect standardization method, or equivalently the standardized mortality ratio (SMR), has been recommended for small areas where age-specific rates can be quite variable. Although theoretically equivalent to directly adjusted rates under the assumption of independent age and area effects, indirect summary measures are not comparable across areas when this assumption is violated. We tested the validity of this assumption for the 10 most common causes of death in the United States during 1980-84 and examined the geographic clustering apparent when categorized death rates, adjusted by different methods, are presented as thematic maps. Although overall agreement between the methods was good (rank correlation coefficient > 82 per cent for each cause), when the adjusted rates were classified into quintiles 18 per cent of the states fell into different categories depending on the method of adjustment. Using an internal standard for the indirect method reduced this discrepancy to 4.9 per cent. However, both traditional chi-square tests and a generalized logistic spline model identified significant interactions between age and area for each cause of death, a violation of the assumption required for equivalence of the methods. Potential variation in geographic inferences is illustrated by maps of direct and indirect rates and an empirical Bayes posterior mean, which is a function of these traditionally adjusted rates. Based on these results, we recommend the direct age-adjustment method for rate maps.

Adolescent↗
PubMedDate not supplied

Cognitive functioning in the last year of life as a function of age, gender, and race.

Research has shown that many factors affect cognitive functioning. In this study cognitive functioning was analyzed using proxy reports concerning 17,135 decedents included in the 1993 National Followback Mortality Study conducted for the National Center for Health Statistics. These responses form a representative sample of all U.S. residents over age 15 who died in 1993 (except for those in South Dakota, which did not participate). Decedents had more difficulty understanding where they were than remembering what year it was or in recognizing family members. Logistic regression models found that age, gender, and race were the most important predictors of these basic cognitive functions. Although increasing age was associated with more cognitive difficulties, men had fewer deficits than women and Black Americans tended to have fewer deficits than White Americans. Possible reasons for these findings are discussed as well as some general implications for health service provision.

Black or African American↗
PubMedDate not supplied

Smokeless tobacco and cancer in women: implications for cancer research.

Smokeless tobacco, particularly snuff, is a recognized risk factor for cancer of the oral cavity. This conclusion rests in large part on epidemiologic studies of oral cancer in women, especially in the American South, where the oral cancer death rate in females has been high. The research focus on studies of women led to the identification of the hazards from smokeless tobacco use; the strategies used are broadly applicable to studies of the etiology of other cancers in both women and men. High levels of nitrosamines, which are potent carcinogens, are found in smokeless tobacco products. Steps should be taken to reverse the alarming increase in their use by men and boys. More research attention also should be directed to understanding new emerging trends in oral cancer mortality among women.

Adolescent↗
PubMedDate not supplied

Epidemiology of bronchioloalveolar carcinoma.

Descriptive features of bronchioloalveolar carcinoma (BAC) are presented using Surveillance, Epidemiology and End Results Program population-based incidence data from 1973 through 1987, along with risk factors from histologically confirmed cases of BAC identified in a hospital-based case-control study conducted in Louisiana between 1979 and 1982. Compared to the rising incidence of lung cancer overall, BAC rates have remained relatively constant, accounting for less than 3% of all lung cancer. BAC incidence rates were higher in males, yet it explained proportionately more of the total lung cancer incidence in females. In the case-control study, 21 of the 33 cases originally ascertained from hospital pathology records were histologically confirmed as BAC. Most cases smoked cigarettes, with a 4-fold risk for ever smoking. Risks tended to increase with smoking intensity (reaching 10-fold for more than 1.5 packs/day) and duration (reaching 5-fold for more than 45 years of smoking). Following 10 or more years of employment, there was a 4-fold risk associated with motor freight occupations, along with nonsignificant excesses among construction workers, petroleum manufacturers, and sugar cane farmers. Cases were more likely than controls to have had emphysema or to have had a close family member with lung cancer. Although based on small numbers, this study suggests that BAC shares many of the epidemiological characteristics of lung adenocarcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗