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Biomedical subjects

C R Key

Publications and source records attributed to C R Key.

At least 91 records · Page 5Linked to original sources

Use of hair dyes and risk of bladder cancer.

The relation between use of hair dyes and risk of bladder cancer was assessed using data from a case-control study of bladder cancer. Incident cases (2982) and general population controls (5782) were interviewed. The overall estimate of relative risk of bladder cancer for users of hair dyes was 1.0 (95%) confidence interval, 0.9 to 1.2) compared to nonusers. No consistent pattern of association was detected between bladder cancer risk and various indices of timing or intensity of exposure to hair dyes. Various explanations of the lack of association are discussed.

Female↗

Carcinoma of the cervix in Southwestern American indians: results of a cytologic detection program.

Age-specific detection rates for newly diagnosed in situ and invasive uterine cervical carcinoma were determined in a nine-year cytologic cancer detection program during which 34,700 Southwestern American Indian women and 46,200 medically indigent non-Indian women were screening for cervical cancer. For patients less than 35 years of age, cervical carcino a was found more frequently among Indians and Spanish-American Caucasians than among other Caucasian women. At ages 60 and older, the Indian cervical cancer rate was much higher than that of non-Indians. The detection rate for invasive cervical carcinoma among Indian patients is inversely related to the proportion screened at 30 years of age or older. Although at least 60% of Indian women 20 years old, and older, in the geographic area served by the detection program were screened for cervical cancer during the nine-year period, only 27% of those 50 years or older were screened. The age-related variation in screening percentage, in conjunction with the disproportionately large numbers of younger low-risk women, serves to explain the finding of significant invasive cervical carcinoma in an extensively screened population.

Adolescent↗

Respiratory disease mortality in New Mexico's American Indians and Hispanics.

To determine the effect of ethnic group on respiratory disease occurrence, average annual sex, ethnic, and disease specific mortality rates for the period of 1969 to 1977 were calculated for New Mexico's American Indian, Hispanic, and Anglo populations. Incidence data were available for respiratory tract cancer. This study corroborates previous findings of reduced mortality from lung cancer in American Indians of both sexes and in Hispanic males. American Indian mortality from tuberculosis and from influenza and pneumonia was high. Hispanic males and American Indians of both sexes showed low mortality rates for chronic obstructive pulmonary disease (COPD). Differing cigarette usage is the most obvious explanation for the variations in COPD and lung cancer occurrence with ethnic group.

Adolescent↗

Altitude and ischemic heart disease in tricultural New Mexico: an example of confounding.

The relationship of male white ischemic heart disease (IHD) death rates to altitude falls to negligible levels when New Mexico populations are separated into Hispanic and Anglo. Low rates of IHD mortality characterize Hispanic males in New Mexico regardless of altitude. In comparison, New Mexico Anglo males have rates near the US average. The variable showing the most consistent positive relationship with altitude is per cent Hispanic. Mortimer et al. (N Engl J Med 296:581--587, 1977) reported a reduction in coronary heart disease mortality in New Mexico white males with an increase in altitude. The current authors claim that this is an example of confounding. They find that the relationship between IHD mortality and altitude is largely due to the intervening variable, per cent Hispanic. Ethnicity demands major attention in epidemiologic studies in tricultural New Mexico.

Altitude↗

Comparative late effects of X-rays and negative pimesons on the mouse kidney.

A system is described for comparing various modalities and fractionation schedules of radiation by means of their long-term morphologic effects upon the mouse kidney. The comparison system utilizes a grading scale for histopathologic changes in which a given histologic grade depends upon meeting defined threshold criteria, rather than quantitation of a particular measurement. Renal tubular alterations served as the basis for comparison, since they appeared more reliably defined than glomerular changes. The radiation dose that induced a specific threshold effect in kidneys from 50% of the animals at 6 months was defined as the effective dose-50%, or ED50.ED50 was found for x-rays and negative pimesons administered in 1, 2, or 5 fractions. From these data, the relative biologic effectiveness (RBE) of negative pi-mesons with respect to x-rays was determined for each fractionation schedule.

Animals↗

Gallbladder disease and gallbladder cancer among American Indians in tricultural New Mexico.

Previous studies have reported high rates of gallbladder disease and gallbladder cancer among all American Indians. Data from the New Mexico Tumor Registry confirm these findings, specifically showing high rates for New Mexico's American Indians, as well as for the state's Spanish population. This review explores several risk factors, including parity, obesity, age, cholesterol level, and genetic factors. From the available evidence, genetic factors appear to be the most important, with parity a contributing factor.

Epidemiologic Methods↗

Carcinoma of the gallbladder in a population of Southwestern American Indians.

The clinical and pathological characteristics of gallbladder carcinoma were studied in a group of 56 Southwestern American Indian patients. This is the third most common malignant tumor among American Indian females in a population served by the New Mexico Tumor Registry accounting for 8.5% of specific cancer diagnoses by site. Carcinoma of the gallbladder is relatively more common within the Indian population than among Spanish Americans or Anglos living in this area. This is true for both sexes. No significant differences in average age at diagnosis, ratio of female to male patients, signs and symptoms, stage at diagnosis or survival were detected in comparison with studies pertaining to gallbladder carcinoma in non-Indian populations. A squamous cell carcinoma component was unusually common however, and carcinoma in situ or atypical adenomatous hyperplasia of the mucosa was frequently documented adjacent to invasive carcinoma. Although gall stones were present in tumor containing gallbladders in 93% of cases, elective cholecystectomy for cholelithiasis is probably not a practical means of prevention of this tumor in view of the unusual frequency of cholelithiasis in Indian women. Pharmacological conversion of bile to a non-lithogenic form may deserve consideration as prophylaxis against both cholelithiasis and carcinoma of the gallbladder in this population.

Adenocarcinoma↗

Multiple primary cancers: relative risk in New Mexico's triethnic population.

A review of the population-based New Mexico Tumor Registry data identified 446 patients with nonsimultaneous multiple primary cancers, excluding non-melanoma skin cancers and carcinomas in situ of the uterine cervix. Expected numbers of cases were established by observing the person-years of exposure to the risk of developing a second or subsequent primary cancer and then applying the appropriate locally determined age-, sex-, ethnic-, and site-specific cancer incidence rates. The relative risk (observed/expected) of developing a second primary cancer was elevated for "Anglo" and Spanish American cancer patients in comparison with the risk of developing a first primary cancer in persons who have never had one. Only six cases of nonsimultaneous multiple primary cancer were observed (6.39 expected) in the region's American Indian population. There were differences in site-site associations among the three ethnic groups, but in many categories there were too few cases for analysis.

Ethnicity↗

Aging in Hiroshima and Nagasaki atomic bomb survivors. Speculations based upon the age-specific mortality of persons with malignant neoplasms.

Evaluation of 1639 malignant tumors from 3067 autopsies of members of the Extended Life Span Study Sample reveals that death occurs earlier in those persons most heavily irradiated ([unk]100 rad) compared with those persons who were less exposed. This effect is particularly pronounced in the younger age categories and among females and is not attributable to a specific neoplasm. Assuming that a positive correlation exists between aging and the age-specific mortality of persons with neoplasms, it is concluded that this response is consistent with other observations which suggest the presence of accelerated or precocious aging in the most heavily irradiated group of survivors.

Adolescent↗