Testosterone and progesterone titers were determined by RIA in the plasma of pregnant rats and their male and female fetuses from day 17 of gestation through the day of birth and in male and female neonates on days 3 and 5 post partum. Males had significantly higher mean testosterone levels than females from day 18 of gestation through day 5 post partum. Sex differences in plasma testosterone concentrations were greatest in the fetuses on days 18 and 19 of gestation when testosterone levels peaked in the males. Instances in which female fetuses had testosterone titers equal to or greater than their male littermates were found on every day of gestation except day 18. Mean testosterone concentrations in plasma of female fetuses were high throughout gestation (greater than 1000 pcg/ml). Testosterone concentrations decreased in both sexes after birth. Differences between the sexes remained significant, and although there was an overlap in the values for males and females, testosterone concentrations in females exceeded those of their male littermates in only one out of nine pairs of samples on day 5 and in none of seven pairs on day 3 post partum. There were no significant differences in progesterone levels in plasma of males and females, either pre- or postnatally. Progesterone titers changed as a function of days post conception in both the fetuses and their mothers. In the fetuses, progesterone levels declined progressively from day 18 post conception through the day of birth, while in the mother they rose from days 18 to 19 then declined between days 20 and 21 of pregnancy. Fetuses had lower progesterone titers than their mothers. From these data, we conclude that day 18 and possibly day 19 post conception represent a critical period during which the central nervous system of the male is primed by high levels of testosterone. Thereafter, the process of masculinization is completed by exposure to testosterone levels that are relatively low and need not be consistently higher than those of female littermates.
Prostaglandin (PG) production by human breast cancers was investigated in 91 lesions selected so that the distribution of histologic type was similar to that of the general population of mammary carcinomas. With regard to the shape characteristics of the tumors, PG production was higher in lesions classified T1 and T2 than in lesions classified T3 and T4 (T-classification is based on extent of tumor as graded by the International Union Against Cancer), higher in tumors exhibiting a high cellularity than in lesions with a low tumor cell density and higher in tumors in which the cells were still adherent to each other. A high PG production was associated with the presence of neoplastic cells in tumor lymphatic and blood vessels and in axillary lymph nodes. PG production by node metastases was always higher than that by the primary tumor sites. The analysis of the stroma reaction and the presence of edema and necrosis suggest that an active PG synthesis occurred in lesions in which the tumor cell-surrounding stroma presented characteristics of low resistance to invasive growth of cancer cells. With regard to histologic differentiation and histoprognostic grade of lesions, PG production was elevated in carcinomas that retained a minute part of the acinoductal differentiation and in tumors with a moderate or high degree of cancer. A lesion containing a steroid receptor (SR) tended to produce less PG than did an SR-negative tumor. PG production increased slightly according to ages and times of menopause of the patients. PG production occurred early in the natural course of breast cancer and was elevated in tumors at a time when active tumor invasion proceeded. By contrast, PG production decreased later in the course of tumor development. These results indicated that elevated PG production can be used as a marker of high metastatic potential for neoplastic cells in breast cancer.
In a Canadian population-based case-control study of 480 males and 152 female case-control pairs, the relative risk for development of bladder cancer for ever used versus never used cigarettes was 3.9 for males and 2.4 for females, with a dose-response relationship in both sexes. A reduced risk was associated with the use of filter cigarettes compared to nonfilter cigarettes. After control for cigarette usage, a significant risk was noted for male pipe smokers. For male ex-smokers the risk after 15 years of no smoking was less than one-half that of current male smokers. Bladder cancer risk was found for workers in the chemical, rubber, photographic, petroleum, medical, and food processing industries among males and for workers occupationally exposed to dust or fumes among both sexes. Bladder cancer risk was elevated for males consuming all types of coffee, regular coffee, and instant coffee and for females consuming instant coffee, but no dose-response relationship was found. Risk was found for males consuming water from nonpublic supples but not for females. No risk was observed in males or females consuming nitrate-containing foods, beverages other than coffee, or fiddlehead greens. Hair dye usage in females and phenacetin usage in males and females carried no risk. Divergent findings by area for aspirin suggested that an overall association was not causal. Reevaluation of the data on artificial sweeteners confirmed a significant bladder cancer risk in males and a dose-response relationship. The cumulated population attributable risk for bladder cancer was 90% for males from cigarette smoking, industrial exposure, and exposure to nonpublic water supplies and 29% for females from cigarette smoking, industrial exposure, and instant coffee consumption.
A study of the incidence and prevalence of rheumatoid arthritis conducted in Rochester, MN, during the period 1950 through 1974 revealed an average annual incidence rate of 28.1 per 100,000 population for males and of 65.7 per 100,000 for females. These rates include classic, definite, and probable cases. Age-specific rates generally increased with age. The secular trend of the incidence in males and females differed. Rates for males, although fluctuating, remained relatively stable throughout the entire 25-year period, whereas rates for females declined dramatically during the last 10 years of the study. The decline was present both in cases presenting as definite at the time of earliest diagnosis and in the probable cases. No explanation was found for the observed decline, but the authors believe that a factor introduced in the 1960s and acting selectively on females has affected the incidence rates. From recent evidence, it could be inferred that oral contraceptives and postmenopausal estrogens are likely causes. Prevalence rates for January 1, 1975, were 4.0 per 1000 for males and 10 per 1000 for females. Among adults, prevalence rates were 5.8 per 1000 for males and 13.4 for females. Mortality among the patients with rheumatoid arthritis was not different from that for the total Olmsted County population.
The value of population screening as an approach to cancer control is controversial because the objectives, benefits, costs, and potential adverse effects of screening programs are not widely agreed upon, nor are the many difficulties involved in evaluating a cancer screening program well recognized. A review of the issues pertinent to cancer screening and their interrelationships is presented. The characteristics of a particular cancer that should be considered before it becomes the target of a screening program are described; emphasis is placed on the prevalence of the detectable preclinical phase. The features of a good screening test are reviewed and the importance of specificity is indicated. Methods for evaluation of screening programs are considered, and the need for measurement of the effects of screening on the mortality rate is emphasized. The biases inherent in some commonly used evaluation procedures, especially lead time bias and length bias, are discussed. The possible adverse effects of cancer screening are pointed out, especially its capacity to increase morbidity. Several approaches to improving cancer screening programs are presented. Finally, the relevance of knowledge regarding the optimum interscreening interval to cancer control and to research issues is described.
In previous studies it could be demonstrated that in severe hypothalamic amenorrhea, which is associated with absent or deficient hypothalamic secretion of Gn-RH, ovarian function could be restored by chronic intermittent (pulsatile) administration of Gn-RH. In order to apply chronic intermittent administration of Gn-RH as a new mode of treatment of infertility in hypothalamic amenorrhea on an outpatient basis a portable device ("Zyklomat") was constructed consisting of a peristaltic pump, a computerized timing device and a Gn-RH containing bag, which delivers 50 microliters of a Gn-RH containing solution once every 90 minutes via an i.v. catheter into the circulation. It is the purpose of this communication to present this new method of treatment and the successful induction of the first two pregnancies with this method in two patients with severe hypothalamic amenorrhea.