RESUMO
The Almendares River is central to recreational and other activities in Havana, Cuba. However, monitoring indicated significant heavy metal contamination in river sediments, especially below Calle 100, the largest landfill in Havana. This work extended previous sediment studies by determining complementary Cu, Pb, Ni, Cr, Cd, and Zn levels in indigenous water hyacinths (Eichhornia crassipes; EC) above and below the landfill. Pb, Cu, and Zn were significantly elevated in EC roots below the landfill and also correlated with sediment data (p < 0.05), implying elevated levels likely result from landfill activity and might be useful biomonitors as river remediation proceeds.
Assuntos
Eichhornia/química , Metais Pesados/análise , Rios/química , Poluentes Químicos da Água/análise , Monitoramento AmbientalRESUMO
This work was aimed to evaluate genotoxicity and antigenotoxicity activity against gamma-rays of a tannin fraction obtained from barks of Pinus caribaea, as well as to elucidate the antigenotoxic mechanisms involved in radioprotection by using different approaches as pre-, co- and post-irradiation cell treatments with plant extract. The tannin fraction was not genotoxic to Escherichia coli cells in experiments using different exposure times. This extract was antigenotoxic against gamma-rays when the cells were pre- or co-treated with this extracts, but not during post-irradiation treatments, suggesting a possibly antigenotoxic action through free radical scavenging mechanisms. The results are discussed in relation to the chemopreventive and therapeutic potential of the studied plant species.
Assuntos
Dano ao DNA/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/efeitos da radiação , Pinus/química , Taninos/farmacologia , DNA Bacteriano/efeitos dos fármacos , DNA Bacteriano/efeitos da radiação , Escherichia coli/genética , Raios gama , Testes de Mutagenicidade/métodos , Casca de Planta/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/toxicidade , Protetores contra Radiação/isolamento & purificação , Protetores contra Radiação/farmacologia , Protetores contra Radiação/toxicidade , Taninos/química , Taninos/isolamento & purificação , Taninos/toxicidadeRESUMO
The natural history of HIV infection has been dramatically changed by the highly active antiretroviral therapies, reducing complications, morbidity and mortality of the disease. Approximately 25% of persons infected with HIV are co-infected with hepatitis C, and some high risk populations have a prevalence of HCV of more than 75%. Liver disease has become one of the principal causes of morbidity and mortality in this population. Co-infection increases viremia of hepatitis C, with increase in fibrosis progression, cirrhosis and death related to hepatitis C. The permanent state of chronic immune activation related to the persistent hepatitis C virus favors transcription of HIV in infected cells and causes a more rapid destruction of T4 and absolute lymphocytes. In addition, the immunologic response after the start of highly active antiretroviral therapy for HIV is less than in mono-infected patients. The role of liver biopsy in the management of co-infected patients is controversial. Many of these patients, even with normal transaminases, show fibrosis in liver biopsy. Predictive factors for advanced fibrosis include male sex, alcohol consumption in excess of 50 grams per day, age over 35, and HIV infection of more than 15 years with CD4 lymphocytes less than 400/ mm3. The treatment of hepatitis C is limited and sustained viral response is less than 30% for genotypes 1 and 4. This response is even less in the more advanced stages of HIV and hepatitis C. The determination of when to start treatment and the increased toxicity when combining pegylated interferon plus ribavirin and antiretroviral medications makes the management of these patients more difficult. The development of more potent, safe and tolerated medications is required. Management strategies for patients unresponsive to conventional therapy are geared towards improving liver histology and delaying progression to cirrhosis, hepatocellular cancer and liver transplantation.