A chemical status predictor. A methodology based on World-Wide sediment samples.

As a consequence of the limited resources of underdeveloped countries and the limited interest of the developed ones, the assessment of the chemical quality of entire water bodies around the world is a utopia in the near future. The methodology described here may serve as a first approach for the fast identification of water bodies that do not meet the good chemical status demanded by the European Water Framework Directive (WFD). It also allows estimating the natural background (or reference values of concentration) of the areas under study using a simple criterion. The starting point is the calculation the World-Wide Natural Background Levels (WWNBLs) and World-Wide Threshold Values (WWTVs), two indexes that depend on the concentration of seven elements present in sediments. These elements, As, Cd, Cr, Cu, Ni, Pb and Zn, have been selected taking into account the recommendations of the UNEP (United Nations Environment Programme) and USEPA (United States Environmental Protection Agency), that describe them as elements of concern with respect to environmental toxicity. The methodology has been exemplified in a case study that includes 134 sediment samples collected in 11 transitional water bodies from 7 different countries and 4 different continents. Six of the water bodies considered met the good chemical status demanded by the WFD. The rest of them exceeded the reference WWTVs, at least for one of the elements. The estuaries of the Nerbioi-Ibaizabal (Basque Country) and Cavado (Portugal), the sea inlet of Río San Pedro (Spain), the Sepetiba Bay (Brazil) and the Yucateco lagoon (Mexico) belong to that group.

Mercury methylation rates of biofilm and plankton microorganisms from a hydroelectric reservoir in French Guiana.

The Petit-Saut ecosystem is a hydroelectric reservoir covering 365km(2) of flooded tropical forest. This reservoir and the Sinnamary Estuary downstream of the dam are subject to significant mercury methylation. The mercury methylation potential of plankton and biofilm microorganisms/components from different depths in the anoxic reservoir water column and from two different sites along the estuary was assessed. For this, reservoir water and samples of epiphytic biofilms from the trunk of a submerged tree in the anoxic water column and from submerged branches in the estuary were batch-incubated from 1h to 3 months with a nominal 1000ng/L spike of Hg(II) chloride enriched in (199)Hg. Methylation rates were determined for different reservoir and estuarine communities under natural nutrient (reservoir water, estuary freshwater) and artificial nutrient (culture medium) conditions. Methylation rates in reservoir water incubations were the highest with plankton microorganisms sampled at -9.5m depth (0.5%/d) without addition of biofilm components. Mercury methylation rates of incubated biofilm components were strongly enhanced by nutrient addition. The results suggested that plankton microorganisms strongly contribute to the total Hg methylation in the Petit-Saut reservoir and in the Sinnamary Estuary. Moreover, specific methylation efficiencies (%Me(199)Hg(net)/cell) suggested that plankton microorganisms could be more efficient methylating actors than biofilm consortia and that their methylation efficiency may be reduced in the presence of biofilm components. Extrapolation to the reservoir scale of the experimentally determined preliminary methylation efficiencies suggested that plankton microorganisms in the anoxic water column could produce up to 27mol MeHg/year. Taking into account that (i) demethylation probably occurs in the reservoir and (ii) that the presence of biofilm components may limit the methylation efficiency of plankton microorganisms, this result is highly consistent with the annual net MeHg production estimated from mass balances (8.1mol MeHg/year, Muresan et al., 2008a).

Regulation of estrogen target genes and growth by selective estrogen-receptor modulators in endometrial cancer cells.

OBJECTIVE: Tamoxifen has mixed agonist/antagonist activities, leading to tissue-specific estrogen-like actions and endometrial cancer. The purpose of this study was to evaluate the effects of antiestrogens on the growth of estrogen receptor (ER)-positive ECC-1 endometrial cancer cells in vitro and in vivo. METHODS: We performed growth studies and luciferase assays using ERE-tK and AP-1 reporters. ERalpha protein expression was measured by Western blot after antiestrogen treatments. We investigated the actions of antiestrogens on the transcription of the pS2 gene in situ measured by Northern blot and the actions of antiestrogens on the VEGF protein secreted by ELISA. ERalpha, ERbeta, EGFR, and HER2/neu mRNAs were determined by RT-PCR. Last, ECC-1 tumors were developed by inoculation of cells into ovariectomized athymic mice and treated with estradiol (E2), tamoxifen, raloxifene, and a combination. RESULTS: E2 induced cell proliferation while antiestrogens did not. E2 and raloxifene down regulated ERalpha protein; in contrast, 4OHT did not. ICI182,780 completely degraded the receptor. ECC-1 cells express ERbeta at insignificant levels. Luciferase assays did not show any induction in ERE- nor AP-1-mediated transcription by antiestrogens. E2 caused a concentration-dependent increase in pS2 mRNA but antiestrogens did not. E2 increased VEGF expression in a dose-dependent manner and antiestrogens blocked E2 action. E2 down regulated HER2/neu while 4OHT and raloxifene did not change HER2/neu levels compared to control. In addition, EGFR mRNA was down regulated by E2 but raloxifene did not change it. Tamoxifen and raloxifene did not promote tumor growth in vivo. However, raloxifene (1.5 mg daily) only partially blocked E2-stimulated growth. CONCLUSION: Tamoxifen and raloxifene are antiproliferative agents and antiestrogens in ECC-1 endometrial cells in vitro and in vivo. The observation that selective estrogen-receptor modulators do not down regulate EGFR and HER2/neu mRNA may provide a potential role for these oncogenes in the development of raloxifene- or tamoxifen-stimulated endometrial cancer. The ECC-1 cell line could provide important new clues about the evolution of drug resistance to tamoxifen and raloxifene.

The structure of DSM-IV alcohol dependence in a treatment sample of Mexican and Mexican American men.

AIMS: To examine the symptom profile and factorial structure of DSM-IV alcohol dependence. DESIGN: Subjects were interviewed in program facilities by trained interviewers using a standardized questionnaire. The response rate was 95% in Mexico and 90% in the United States. SETTING: Two publicly funded inpatient facilities in Mexico and five in the United States. In Mexico the programs were located in Mexico City. In the United States the programs were located in Santa Clara County, California. PARTICIPANTS: Three hundred and ninety-one Mexican and 212 Mexican American men in treatment for alcohol problems in Mexico and the United States. MEASUREMENT: Dependence criteria were assessed with the Composite Diagnostic Interview-Substance Abuse Module (CIDI-SAM). FINDINGS: The unidimensional structure of alcohol dependence fits the Mexican American data but not the Mexican data. However, when Mexican clients were divided according to place of interview (treatment program), the unidimensional structure fits one of the groups but not the other. CONCLUSIONS: The test of unidimensionality must be seen as inconclusive with regard to the Mexican data. These results highlight the potential influence that client selection methods may have on study results, especially in cross-cultural projects.

DSM-IV alcohol dependence and drug abuse/dependence in a treatment sample of whites, blacks and Mexican Americans.

This paper examines the association between DSM-IV alcohol dependence, drug use and DSM-IV drug/abuse dependence in a sample of White (n = 256), Black (n = 263) and Mexican American (n = 212) men consecutively admitted to five alcohol treatment programs in a Northern California county. Results show that drug use is higher among Blacks and Mexican Americans than among Whites. About 35% of the Whites 43% of the Blacks and 35% of the Mexican Americans are both alcohol and drug dependent. Among alcohol dependent individuals, about 44% of the Whites, 72% of the blacks and 52% of the Mexican Americans report using at least one drug other than alcohol once a week or more in the 12 months previous to the interview. The drug most frequently used by Whites is marijuana, followed by cocaine and amphetamines. The drug most frequently used by Blacks and Mexican Americans is cocaine, followed by marijuana. Severity of drug dependence is inversely related to severity of alcohol dependence among Whites. Alcohol treatment programs for Whites, Blacks and Mexican Americans must offer assessment, treatment matching and relapse prevention that takes into consideration this high prevalence of drug use and dependence.

DSM-IV alcohol dependence in a treatment sample of white, black, and Mexican-American men.

This study examines the presentation, correlates, and factor structure of DSM-IV alcohol dependence among 256 White, 263 Black, and 212 Mexican-American men admitted consecutively to five alcohol treatment programs in San Jose, CA. Interviews of approximately 1 hr were conducted in the programs' facilities by trained interviewers using a standardized questionnaire. The response rate was 87%. Results show that the proportion of Black respondents who are alcohol-dependent according to the DSM-IV criteria is lower (63%) than the proportion of Whites (86%) and Mexican Americans (76%). However, the proportion of respondents reporting each criterion of dependence was similar across groups. The most powerful predictor of the number of dependence indicators reported by respondents was level of alcohol consumption, independent of ethnicity. A unidimensional model of dependence combining all seven indicators of DSM-IV alcohol dependence fit well across men in all three ethnic groups. These results indicate that both the presentation and factorial structure of DSM-IV alcohol dependence were uniform across White, Black and Mexican-American men in treatment for alcohol problems.