Organochlorine exposure and breast cancer risk in Colombian women.

An epidemiological study was performed in Santa Fé de Bogota, Colombia, with a total of 306 women enrolled, including 153 incident BC cases and 153 age-matched controls. The objective of this study was to evaluate the association between BC risk and serum dichlorodiphenyl-dichloroethene (DDE) levels. Sociodemographic and reproductive data, diet, and past exposure to pesticides were obtained through a structured questionnaire. Chemical analysis of samples was performed by high resolution gas chromatography-ECD. Likelihood of developing BC by exposure to these substances was evaluated through odds ratios (OR) adjusted for: first-child breast-feeding, family BC history, body mass index (BMI), parity, and menopausal status. Data analysis was performed by conditional logistic regression techniques. Adjusted OR for exposure to serum DDE and BC suggests an increase risk of BC in the higher category of DDE exposure (OR=1.95; CI 1.10-3.52). The test for trend was not statistically significant (p=0.09). We confirm that serum DDE levels bear a positive association to risk of BC and could support the association between risk of BC and burden of DDE exposure.

Organochlorine exposure and breast cancer risk in Colombian women

Em estudo epidemiológico realizado em Santa Fé de Bogotá, Colômbia, 153 casos incidentes de câncer de mama (CM) foram comparados com 153 controles, pareados por idade. Avaliou-se a associaçäo entre o risco de CM e níveis séricos do pesticida DDT(DDE). Dados reprodutivos e sócio-demográficos, características da dieta e informaçäo sobre exposiçäo pregressa a pesticidas foram obtidos por meio de questionário. A análise química de amostras de sangue foi realizada através de cromatografia a gaz de alta resoluçäo - ECD. A verossimelhança de desenvolver CM como decorrência de exposiçäo a estas substâncias foi avaliada através de odds ratios (OR), obtidas por técnicas de regressäo logística condicional, ajustadas para amamentaçäo do primogênito, história familiar de CM, índice de massa corporal, paridade e presença de menopausa. As OR ajustadas sugerem um risco aumentado de CM no estrato de maior exposiçäo a DDE (OR + 1,95; C.I. 1,10-3,52), embora o teste de tendência fosse estatisticamente näo significativo (p=0,09). Os resultados encontrados constataram que os níveis séricos de DDE estäo positivamente associados com o risco de CM, e poderiam apoiar a hipótese desta associaçäo.

Chronic treatment with beta adrenergic agonists and antagonists alters the composition of proteins in rat parotid saliva.

This investigation was undertaken to determine the role of beta-adrenergic receptors in the regulation of the protein composition of rat parotid saliva. Chronic treatment of rats with dobutamine, a beta 1-adrenergic agonist, resulted in changes in parotid saliva volume, protein concentration, and composition which were essentially the same as those changes which occurred following chronic treatment with isoproterenol, a non-specific beta-adrenergic agonist. Chronic treatment with the beta 2-adrenergic agonist, terbutaline, had no effect on parotid saliva volume, protein concentration, or composition. Chronic treatment of rats with a beta 1-adrenergic antagonist, metoprolol, had different effects on saliva dependent on the manner by which the drug was delivered. Twice-daily injections of metoprolol led to a decrease in flow rate, but protein concentration and composition were unaltered. When metoprolol was delivered by surgically implanted osmotic minipumps, neither the flow of parotid saliva nor its concentration of protein was altered; however, there was a reduction in the proportion of proline-rich proteins in saliva. Comparable changes in parotid saliva protein composition occurred when the minipumps delivered propranolol, a non-specific beta-adrenergic antagonist. Chronic treatment of rats with an alpha 2-adrenergic agonist (clonidine) or antagonist (yohimbine) was without effect on parotid saliva flow rate, protein concentration, or composition. These findings suggest that the synthesis of proline-rich proteins is regulated, in part, by beta-adrenergic receptor stimulation, and primarily by the beta 1-receptor subtype.

Regulation of parotid salivary proteins by glucocorticoids.

Previous studies have indicated that adrenal-intact rats treated for one week with pharmacological doses of the synthetic glucocorticoid, dexamethasone, show a significant reduction in the proportion of proline-rich proteins and an increase in the proportion of amylase in rat parotid saliva (Johnson et al., 1987). In order to understand more fully the role of glucocorticoids in the regulation of salivary proteins, we performed bilateral adrenalectomies on groups of rats. Some of the adrenalectomized rats were treated with replacement-level doses of the synthetic glucocorticoid, dexamethasone. The food intake was monitored daily for both groups, and sham-operated pair-fed controls were included so that the effects of alterations of food intake could be separated from those of the experimental procedures. After eight to 12 days, uniformly stimulated parotid saliva was collected from these animals as well as from sham-operated controls fed ad libitum. The volume of saliva collected in 30 min was recorded, and the saliva samples were analyzed for concentration and composition of protein. Although the volume of saliva was not affected, parotid saliva collected from adrenalectomized rats exhibited a two-fold greater proportion of proline-rich proteins and reductions in other major secretory proteins: DNase, Fraction I, and Fraction V. The parotid gland secretory granules of adrenalectomized rats were more electron-lucent than in the ad libitum-fed controls. Treatment of adrenalectomized rats with dexamethasone largely prevented the changes in salivary protein composition as well as the alterations in secretory granule morphology.(ABSTRACT TRUNCATED AT 250 WORDS)