Knud J Helsing

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Histories of depression-related symptoms were obtained from 3845 randomly selected adult residents of Kansas City, Missouri, and Washington County, Maryland. Depressed persons were slightly more common in Kansas City than in Washington County but within the latter area no urban-rural differences were observed. More depressed persons were found among blacks(More)
In 1974, approximately 13,000 female residents of Washington County, Maryland, donated 15 ml of blood as part of a project to determine if certain serologic factors were related to the development of site-specific cancer. Sera were stored at -73 C. The present study reports the associations of serum levels of estrone, estradiol, estriol, androstenedione,(More)
Blood samples taken in 1974 in Washington County, Maryland, from 25 620 volunteers were used to investigate the relation of serum 25-hydroxyvitamin D (25-OHD) with subsequent risk of getting colon cancer. 34 cases of colon cancer diagnosed between August, 1975, and January, 1983, were matched to 67 controls by age, race, sex, and month blood was taken. Risk(More)
Mortality associated with passive smoking was evaluated in a 12-year study of 27,891 White adult smokers and 19,035 never smokers identified in 1963. Death rates were calculated using an estimate of the person-years at risk. Adjusted for age, marital status, education, and quality of housing, the estimated relative risks of death from all causes were 1.17(More)
We studied the relation of serum vitamin A (retinol), beta-carotene, vitamin E, and selenium to the risk of lung cancer, using serum that had been collected during a large blood-collection study performed in Washington County, Maryland, in 1974. Levels of the nutrients in serum samples from 99 persons who were subsequently found to have lung cancer (in 1975(More)
A study was undertaken to determine whether prediagnostic serum levels of retinol, beta-carotene, vitamin E, and selenium are lower in colon cancer cases compared with matched, population-based controls. Sera were available from 25,802 participants of a serum collection campaign conducted in Washington County, Maryland in 1974. The authors identified from(More)
A private census of Washington County, Maryland, in 1963 obtained information on smoking habits of all adults in the census, and death certificates of all residents who died in the next 12 years were coded for underlying cause of death and matched to the census. Among the white population aged 25 and over, 4,162 men and 14,873 women had never smoked. In(More)
Colorectal cancer incidence rates for smokers, nonsmokers living with smokers (i.e., passive smokers), and nonsmokers in smoke-free households were compared in a 12-year prospective study of 25,369 women who participated in a private census conducted in Washington County, MD, in 1963. Women who smoked had a decreased relative risk of colorectal cancer(More)
In the course of a Community Mental Health Epidemiology study conducted in Washington County, Maryland between December, 1971 and July, 1974, interviews were conducted with randomly selected adults in a weekly systematic sampling of households. In a subsequent re-interview of 1009 respondents who had family cars with seat belts, nearly 47 per cent said they(More)