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S Selvin

Publications and source records attributed to S Selvin.

At least 73 records · Page 4Linked to original sources
PubMed1983

Selected epidemiologic observations of cell-specific leukemia mortality in the United States, 1969-1977.

Utilizing a newly available data set which includes for the first time cell-specific leukemia mortality rates for the United States during 1969-1977, age and sex distributions, time trends, and geographic patterns were analyzed. Four major cell types of leukemia were considered. Acute lymphatic leukemia had a bimodal distribution with the first peak in the 5-9-year age group and lowest rates in age group 35-44, after which rates rose geometrically. Acute myeloid leukemia had only a very small childhood peak with a low in the age group 5-9, after which the rates also rose geometrically. For both chronic lymphatic and myeloid leukemia the rates rose geometrically after age 15. Rates among females were consistently lower for each age group. The highest sex ratio was found for chronic lymphatic leukemia and is proposed to be the result of a lag period between male and female rates. During the period under study acute lymphatic leukemia mortality in adults declined by almost 10% while acute myeloid leukemia mortality increased by almost 20%. Analysis of the geographic variation of the four major cell types revealed a geographic association between acute lymphatic and acute myeloid leukemia in children, a lack of association between childhood and adult cell types, and an association of acute and chronic cell types in adults.

Adolescent↗
PubMed1982

An alternative to ecologic regression analysis of mortality rates.

A number of recent papers have used geographically defined data and linear models to study the relationship between a series of epidemiologic factors and the frequency of disease. This "ecologic regression" approach involves serious problems of interpretation. An alternate approach is discussed that does not depend on statistical models, produces easily interpreted results and yields statistical summaries that approximately parallel regression analysis. This alternative procedure is illustrated by using acute lymphocytic leukemia mortality data on a county level from among white females less than five years of age between 1969-1977.

Child, Preschool↗
PubMed1982

Major histologic types of cancers of the gum and mouth, esophagus, larynx, and lung by sex and by income level.

Incidence rates by income level were computed for squamous cell carcinomas of the gum and mouth, larynx, and esophagus and for squamous cell carcinoma, small cell carcinoma, and adenocarcinoma of the lung in white males and females aged 35--64 years, with the use of data for the nine geographic areas of the Third National Cancer Survey and the 1970 U.S. census. Within sex, age, and geographic area groups, patterns of cancer incidence by income level were analyzed by use of a nonparametric statistical method. Higher rates for males than for females were found for every histologic type studied, and the ratio of male-to-female rates increased with age (especially for squamous cell carcinomas of the larynx and lung). A strong inverse relation to income level was found for all of the histologic types studied in males and for squamous cell carcinomas of the gum and mouth and esophagus and small cell carcinoma of the lung in females. These findings are discussed with reference to patterns of smoking and alcohol use by sex and social class.

Adult↗
PubMed1982

Effects of caffeine-free diet on benign breast disease: a randomized trial.

There is considerable interest in the potential effect on benign disease of a diet free of methylxanthines (caffeine, theophylline, and theobromine) found in coffee, tea, colas, and chocolate. We randomly assigned 158 women who presented with a breast concern either to a group encouraged to abstain from methylxanthine-containing foods and beverages or to a group who received no dietary recommendations (controls). At the initial visit each patient's sociomedical history and data on methylxanthine consumption were obtained by interview, and clinically palpable breast findings were graded on a scale of 0 to 4 (no nodularity to confluent hard "dysplasia") for each quadrant of both breasts. On the follow-up visit approximately 4 months later similar information was obtained. Mammograms were taken at both visits for a subset of women in each group. We found a statistically significant reduction in clinically palpable breast findings in the abstaining group as compared with controls, but the absolute change was minor and may be of little clinical significance. Comparison of before-after mammograms offered little support for the methylxanthine hypothesis. There was no relation between clinically palpable breast finding scores at initial examination and caffeine consumption levels reported at that time.

Adult↗
PubMed1981

Air sampling in the assessment of continuous exposures to acutely-toxic chemicals. Part I--Strategy.

This paper describes the conceptual basis for assessing the hazard of continuous exposures to acutely toxic chemicals. It is stressed that the variability of workers' short-term exposures to airborne chemicals must be considered in establishing strategic criteria which define an acceptable (or unacceptable) environment. The argument is developed that the traditional strategy of an absolute ceiling limit is unworkable since any set of exposures can be declared out of compliance if a sufficiently large number of samples is collected. It is proposed that acute-exposure limits be defined instead as air concentrations that can be exceeded by an explicit fraction of the population of exposures. An "exceedance" rate of 5% is suggested provided that exposure limits incorporate appropriate safety factors which are relatively large for potent acute toxins and small for irritants. The implications of this strategy are analyzed with some existing ceiling limits proposed by NIOSH.

Air Pollutants↗
PubMed1980

Maximum likelihood estimation for complete or incomplete discrete data.

A computer program is presented that provides estimates of parameters from mathematical models describing discrete data. The program calculates maximum likelihood estimates for both complete and incomplete cases. Also included are the standard errors of the estimates, the expected values and a chi-square criterion for assessing 'goodness of fit".

ABO Blood-Group System↗
PubMed1980

A note on gene frequency estimation with misclassification present.

A genetic model is presented that allows for the maximum likelihood estimation of gene frequencies for simple Mendelian inheritance when specific patterns of misclassification are present. Formulas for the variance of these estimates are also given along with an example of application.

Alleles↗
PubMed1980

Distribution of gene frequencies and discrimination probabilities for 22 human blood genetic systems in four racial groups.

Gene frequencies were computed in four racial categories from 5956 blood donors from California, Hawaii, Mexico City, and Texas. Calculations were based on the phenotypic distribution of 22 blood genetic systems including 7 blood groups and 15 genetically controlled polymorphic proteins and enzymes. Matching probabilities for 20 systems were approximately 1 in 100 000 Asians, 1 in 200 000 blacks, 1 in 330 000 Mexicans, and 1 in 1 000 000 whites. The complementary discrimination probability, which measures the likelihood that two random individuals do not match, was, for practical purposes, unity. The combined new technology for blood grouping and electrophoresis using cellulose acetate membranes provides a powerful individualizing and discriminating tool for forensic science investigation.

Alanine Transaminase↗
PubMed1979

Analysis of cohort effects from cross-sectional data.

A statistical model and computer program are described to analyze data fro the existence of cohort effects. The analysis leads to the separate assessments of cohort, time and age influences on a series of age-specific rates that are available in cross-sectional form. The assessment of these three factors can possibly yield insights into specific disease etiologies.

Age Factors↗
PubMed1979

Cancer incidence by marital status: U.S. Third National Cancer Survey.

Site-specific cancer incidence rates were computed by sex, age, and marital status for whites and blacks separately for ages 35-64 years with the use of population-based incidence data from the Third National Cancer Survey (1969-71) and with demographic data from the 1970 U.S. Census. Although rates were presented for all cancer sites combined and for 44 specific sites or rubrics, discussion focused on the 17 most common cancers. Within age, race, and sex groups, patterns of cancer incidence by marital status were compared by means of standardized incidence ratios, and the consistency of marital status patterns across age groups was assessed statistically. Among the most notable findings were: excess cancer rates across most sites and age groups in single black males, consistently high rates for cancer of the lung and bronchus in divorced white males and in single black females, low rates for the hormone-dependent reproductive tumors (prostate gland, breast, uterine corpus, and ovary) in separated white males and females, and high rates for cervical cancer among separated white women. Marital status patterns, where found, frequently differed between whites and blacks and between males and females.

Adult↗
PubMed1979

Laterality of breast cancer in families.

A new method for analyzing concordance for a binary variable in extended pedigrees was developed to study tumor laterality in families with high incidence of breast cancer. It was found that related breast cancer patients in 15 high-risk Midwestern US families did not have their tumors on the same side more frequently than would be expected by chance. This finding is in contrast to previous studies in London and Denmark that reported a significant concordance for tumor laterality in related breast cancer patients. This result may reflect an increasing incidence of sporadic breast cancer in genetically susceptible families or, alternatively, independent determination of cancer susceptibility and tumor laterality.

Adult↗
PubMed1979

Smoking cessation program: baseline carbon monoxide and serum thiocyanate levels as predictors of outcome.

One hundred and sixty-two smokers who participated in an aggressive smoking cessation program underwent analysis of expired air carbon monoxide (CO) and serum thiocyanate (SCN) at entry and one year later. Persons who failed to quit smoking had higher baseline CO and SCN and smoked more cigarettes per day than did those who succeeded in quitting. The use of CO, SCN, number of cigarettes smoked, age, and blood pressure at baseline permitted accurate classification of over 70 per cent of the subjects into groups which would succeed and fail in their effort to quit smoking. Persons who failed to quit reduced the reported number of cigaretts smoked per day by one-third, but there was no corresponding reduction in CO and SCN, suggesting that self-reporting of a reduction in the number of cigarettes smoked may not lead to a corresponding decline in exposure.

Adult↗