Breast cancer and serum organochlorines: a prospective study among white, black, and Asian women.

Background: Five small case-control studies have examined the relationship between exposure to organochlorines and the risk of breast cancer and have found inconsistent results. In these studies, organochlorine levels in breast cancer patients were measured after (or at most 6 months before) diagnosis.

Purpose: We tested the hypothesis that organochlorines are a risk factor for breast cancer, using prospectively gathered data on serum levels of DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] (the main metabolite of the pesticide DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane]) and polychlorinated biphenyls (PCBs).

Social class: the missing link in U.S. health data.

National vital statistics in the United States are unique among those of advanced capitalist countries in reporting data only by race, sex, and age--not by class and income. This article reviews the limited U.S.

Man-made medicine and women's health: the biopolitics of sex/gender and race/ethnicity.

National vital statistics in the United States present data in terms of race, sex, and age, treated as biological variables. Some races are clearly of more interest than others: data are usually available for whites and blacks, and increasingly for Hispanics, but seldom for Native Americans or Asians and Pacific Islanders. These data indicate that white men and women generally have the best health and that men and women, within each racial/ethnic group, have different patterns of disease.

Understanding AIDS: historical interpretations and the limits of biomedical individualism.

The popular and scientific understanding of acquired immunodeficiency syndrome (AIDS) in the United States has been shaped by successive historical constructions or paradigms of disease. In the first paradigm, AIDS was conceived of as a "gay plague," by analogy with the sudden, devastating epidemics of the past. In the second, AIDS was normalized as a chronic disease to be managed medically over the long term.

Analgesia with anesthetic steroids and ethanol.

Ethanol is well known to enhance the potencies of a range of anesthetics. However, its effects on steroid anesthesia have not been reported. Because ethanol often is added to the delivery vehicle to increase steroid solubility, it is important to evaluate its contribution to steroid anesthesia.

Aluminum inhibits bone nodule formation and calcification in vitro.

Cells isolated from neonatal mouse calvariae can be induced to form mineralized nodules after exposure to ascorbic acid and beta-glycerophosphate. To determine whether aluminum inhibits nodule formation and subsequent mineralization, cells isolated from neonatal mouse calvariae were induced to form nodules and incubated with increasing concentrations of aluminum (10(-7) to 10(-5) M). Compared with control and 10(-7) M aluminum-supplemented cultures, the number of nodules formed and the number of nodules calcified were reduced in cells incubated with 10(-6) and 10(-5) M aluminum.

3 alpha-hydroxy-5 alpha-pregnan-20-one is the only active anesthetic steroid in anesthetized mouse brain.

It was demonstrated that the anesthetic steroid 3 alpha-hydroxy-5 alpha-pregnan-20-one mediates the loss of the righting response (LRR) in mice, in contrast to its metabolites, which are formed in vivo. To reach these conclusions, it was necessary to quantitate levels for 3 alpha-hydroxy-5 alpha-pregnan-20-one and its metabolites at the time of LRR. Methods were used that blocked the production of essentially all of the metabolites.

Thinking and rethinking AIDS: implications for health policy.

In the United States, we see three main phases in the construction of the history of AIDS, with each having very different implications for health and social policy. In the first, AIDS was conceived of as an epidemic disease, a "gay plague," by analogy to the sudden, devastating epidemics of the past. In the second, it was normalized as a chronic disease, similar in many ways to diseases such as cancer.

Surveillance bias and the excess risk of malignant melanoma among employees of the Lawrence Livermore National Laboratory.

To assess the role of surveillance bias in the observed three-fold excess of cutaneous malignant melanoma (CMM) at the Lawrence Livermore National Laboratory (LLNL) in California, we examined the thickness of CMMs among all 20 laboratory employees who were members of a large prepaid health plan and whose CMM was diagnosed from 1970 through 1984. For comparison, we reviewed slides of 36 other members of the same health plan matched (usually 2:1) to the laboratory case by age, sex, facility, and year of diagnosis. Three expert dermatopathologists read the slides using a multiheaded microscope to reach a consensus; they were blind to the laboratory employment status of the subjects.

The emerging histories of AIDS: three successive paradigms.

Thinking of AIDS as an 'emerging disease' inevitably raises questions of comparison. In the United States, we see three main phases in understanding AIDS, with each having very different implications for health and social policy. In the first, AIDS was conceived of as an epidemic disease, a 'gay plague', by analogy to the sudden, devastating epidemics of the past.

Steroid levels in tadpole (Rana catesbeiana) brain at the loss and return of the righting response.

Steroid levels were determined at the onset of anesthesia (tLRR) and at the recovery from anesthesia (tRRR). When 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha) was the administered agent, 3 alpha levels were similar at tLRR and tRRR1. The net rate of uptake of 3 alpha by the brain was approximately eight times the rate of loss of 3 alpha.

Demonstration of sodium/calcium exchange in rodent osteoblasts.

Based on the inhibition of stimulated Ca release from cultured bone by several different agents that alter Na transport, we proposed that hormonally stimulated bone resorption requires Na/Ca exchange. Calcemic hormones appear to interact primarily directly with the osteoblast, which then mediates the activation of osteoclast activity. In organ culture it is not possible to determine whether Na/Ca exchange is involved in this initiating step in the osteoblast or directly in osteoclast-mediated Ca release, and there have been no prior direct measurements of Na/Ca exchange in bone or bone cells.

Overcoming the absence of socioeconomic data in medical records: validation and application of a census-based methodology.

Background: Most US medical records lack socioeconomic data, hindering studies of social gradients in health and ascertainment of whether study samples are representative of the general population. This study assessed the validity of a census-based approach in addressing these problems.

Methods: Socioeconomic data from 1980 census tracts and block groups were matched to the 1985 membership records of a large prepaid health plan (n = 1.

Risk of breast cancer after benign breast diseases. Variation by histologic type, degree of atypia, age at biopsy, and length of follow-up.

The issue of risk of breast cancer subsequent to benign breast diseases (BBD) remains controversial. To determine whether this risk varies by histologic type of BBD, degree of atypia (as measured by the Black-Chabon method), age at BBD biopsy, or length of follow-up, the authors followed 2,731 women in the San Francisco Bay Area for an average of 16 years after their first occurrence of biopsy-proven BBD between 1948 and 1973. The cohort's age-adjusted rate of breast cancer was 1.

Acidosis inhibits osteoblastic and stimulates osteoclastic activity in vitro.

Metabolic acidosis induces net calcium flux (JCa) from cultured neonatal mouse calvariae through physicochemical and cell-mediated mechanisms. To determine the role of osteoblasts in acid-induced JCa, collagen synthesis and alkaline phosphatase activity were assessed in calvariae incubated in reduced pH and bicarbonate medium, a model of metabolic acidosis (Met), and compared with controls (Ctl). Collagen synthesis fell from 30.

Greater unidirectional calcium efflux from bone during metabolic, compared with respiratory, acidosis.

There is a smaller net calcium efflux from bone in vitro during respiratory (increased PCO2) than metabolic (decreased [HCO3-] acidosis. This could be due to the elevated PCO2, which would lessen the driving force for mineral dissolution and increase the driving force for mineralization with respect to carbonated apatite in the bone mineral. To test this hypothesis, we injected neonatal mice with 45Ca and dissected the radiolabeled calvariae 24 h later.

Evidence that 3 alpha-hydroxy-5 alpha-pregnan-20-one is the metabolite responsible for anesthesia induced by 5 alpha-pregnanedione in the mouse.

Mice were anesthetized with [3H]5 alpha-pregnanedione (5 alpha). Brain levels for 5 alpha and its metabolites were quantitated and compared at time points following injection and at two behavioral endpoints that are characteristic of the anesthetized state. The results support the hypothesis that 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha), a metabolite of 5 alpha, mediates this anesthetic response, and they weigh against the hypothesis that 5 alpha itself is solely responsible for activity.

The making of public health data: paradigms, politics, and policy.

Public health data do not simply exist: the variables included or excluded from any given data set reflect the choices of individuals and institutions with the power to make these decisions. Their judgement typically is guided by prevailing theories of disease causation, which in turn usually resonate with their society's predominant political, economic, and ideological characteristics. This essay examines the making of public health data as a social process, both historically and in the present, and critiques the routine omission of social class data from US public health data bases, the treatment of "race" and "sex" as primarily biological variables, and their conflation with ethnicity and gender.

Synthesis of a [1,2-3H]-labeled pregnanolone.

A method is described for the synthesis and purification of 3 alpha-hydroxy-5 alpha-[1,2-3H]pregnan-20-one. [1,2-3H]progesterone (55 Ci/mmol) was incubated with a homogenate of rat brain tissue. The product was purified by Sephadex chromatography and thin-layer chromatography.

In vivo studies identify 5 alpha-pregnan-3 alpha-ol-20-one as an active anesthetic agent.

Mice were anesthetized with 5 alpha-[3H]pregnan-3 alpha-ol-20-one. Brain levels for 5 alpha-pregnan-3 alpha-ol-20-one and its five major metabolites (5 alpha-pregnanedione, k0, k1, k2, k3) were compared at behavioral endpoints that are characteristic of the anesthetized state. The results support the hypothesis that 5 alpha-pregnan-3 alpha-ol-20-one mediates the anesthetic response, and they weigh against the hypothesis that any of its metabolites is solely responsible for the onset or the maintenance of the anesthetized state.