The extractive industry in Latin America and the Caribbean: health impact assessment as an opportunity for the health authority.

OBJECTIVES: The extractive industries have contributed to the economic and social development of Latin America and the Caribbean for centuries. We have undertaken a narrative review to assess the role of the health authority in the decision-making process as it relates to extractive industry projects. METHODS: A narrative literature review was conducted with a keyword search conducted using PubMed, Scientific Electronic Library Online and Google. This was complemented with manual searches of relevant journals and reference lists of primary articles. RESULTS: A broad body of literature from Latin America and the Caribbean region provides evidence that the public health of communities engaged in extractive industry is not being assured and that significant gaps exist in aligning public and private sector efforts to improve health. CONCLUSIONS: Inclusion of the health authority in impact assessment has the potential to result in lasting positive effects on communities involved directly and indirectly in the extractive industry, while preventing a large range of potential adverse health impacts.

Identification of in vivo P-glycoprotein mRNA decay intermediates in normal liver but not in liver tumors.

Post-transcriptional regulation at the level of mRNA stability is one important mechanism for over-expression of P-glycoprotein (Pgp) genes observed in cultured cells and in animals. A previous study has shown that mRNA half-lives for Pgp genes in normal liver were less than 2 h, in contrast to greater than 12 h measured in a transplantable liver tumor line. This lower turnover rate of Pgp mRNA may, in large part, contribute to the abundance of Pgp mRNA in liver tumors. The current study sought to investigate the underlying mechanism for the lower turnover rate of Pgp2 mRNA previously determined in liver tumors. As a first approach, we set out to understand the Pgp2 mRNA decay in both normal liver and liver tumors by first identifying and characterizing Pgp2 mRNA degradation intermediates. In this study, we showed that the sensitive ligation-mediated polymerase chain reaction (LM-PCR) method can be used to detect a homogenous pool of in vitro transcribed RNA down to 0.4 ng. By employing gene-specific primers in the LM-PCR method, we successfully identified four Pgp2 mRNA decay intermediates in normal liver. All four decay intermediates detected correspond to the 5' coding region of Pgp2 mRNA, and surprisingly no decay intermediates which correspond to 3' untranslated region, 3' coding region or middle coding region were found using LM-PCR. The identified decay intermediates are unique to the normal liver as they were absent or present at very low level in all three liver tumor samples analyzed. This observation supports our previous findings that the Pgp mRNA turnover rate is lower in liver tumors than in normal liver. These findings have implications for our understanding of the regulation of Pgp mRNA turnover in normal and malignant tissues.