Genotoxic potential generated by biomass burning in the Brazilian Legal Amazon by Tradescantia micronucleus bioassay: a toxicity assessment study

<p>Abstract</p> <p>Background</p> <p>The Brazilian Amazon has suffered impacts from non-sustainable economic development, especially owing to the expansion of agricultural commodities into forest areas. The Tangará da Serra region, located in the southern of the Legal Amazon, is characterized by non-mechanized sugar cane production. In addition, it lies on the dispersion path of the pollution plume generated by biomass burning. The aim of this study was to assess the genotoxic potential of the atmosphere in the Tangará da Serra region, using <it>Tradescantia pallida </it>as <it>in situ </it>bioindicator.</p> <p>Methods</p> <p>The study was conducted during the dry and rainy seasons, where the plants were exposed to two types of exposure, active and passive.</p> <p>Results</p> <p>The results showed that in all the sampling seasons, irrespective of exposure type, there was an increase in micronucleus frequency, compared to control and that it was statistically significant in the dry season. A strong and significant relationship was also observed between the increase in micronucleus incidence and the rise in fine particulate matter, and hospital morbidity from respiratory diseases in children.</p> <p>Conclusions</p> <p>Based on the results, we demonstrated that pollutants generated by biomass burning in the Brazilian Amazon can induce genetic damage in test plants that was more prominent during dry season, and correlated with the level of particulates and elevated respiratory morbidity.</p

Purification and biological effects of C-type lectin isolated from Bothrops insularis venom

Bothrops insularis is a snake from Queimada Grande Island, which is an island located about 20 miles away from the southeastern coast of Brazil. Compared to other Brazilian species of Bothrops, the toxinology of B. insularis is still poorly understood. Its C-type lectin is involved in several biological processes including anticoagulant and platelet-modulating activities. We purified the C-type lectin (BiLec) from Bothrops insularis venom and investigated its effect in the isolated kidney. BiLec was purified after two chromatographic steps; firstly, the whole venom was submitted to an HPLC molecular exclusion chromatography followed by a second purification through affinity chromatography. B. insularis lectin (BiLec) was studied as to its effect on the renal function of isolated perfused rat kidneys with the use of six Wistar rats. The concentration of 10 mu g/mL increased perfusion pressure (PP; control(60) = 108.27 +/- 4.9; BiLec(60) = 112.9 +/- 5.4 mmHg; *p < 0.05) and renal vascular resistance (RVR; control(60)=5.38 +/- 0.51; BiLec(60)=6.01 +/- 0.57 mmHg; *p < 0.05). The urinary flow reduced significantly at 90 and 120min of perfusion (UF; control(120)= 0.160 +/- 0.020; BiLec(120) =0.082 +/- 0.008mL g(-1) min(-1); *p < 0.05). Glomerular filtration rate (GFR; control(120)=0.697 +/- 0.084; BiLec(120)=0.394 +/- 0.063 mL g(-1) min(-1); *p < 0.05) diminished only at 120 min. BiLec did not change the percentage of sodium (TNa+), potassium (TK+) and chloride tubular transport (TCl-). The histological alterations probably reflected direct injury on glomerular and tubular renal cells, as demonstrated by the rise in permeability of glomerular endothelial cells, revealed by the presence of a proteinaccous material in the Bowman space. We postulate that the C-type lectin B. insularis promoted its effects probably through interactions with endothelial cells or through the release of other mediators by tubular, mesangial and endothelial cells. (c) 2006 Elsevier Ltd. All rights reserved.47885986

Purification and biological effects of L-amino acid oxidase isolated from Bothrops insularis venom

Bothrops insularis is a snake from Ilha da Queimada Grande, an island located about 20 miles away from the Southeastern coast of Brazil. Compared with other Brazilian species of Bothrops, the toxinology of R insularis is still poorly understood, and so far, no fraction from this venom with amino acid oxidase activity had been isolated or its biological activity tested. We investigated the biochemical and biological effects of one L-amino acid oxidase enzyme isolated from R insularis snake venom (BiLAO), which was purified using HPLC and sequence grade. We also evaluated the renal effects induced by BiLAO. Chromatographic profile of B. insularis whole venom disclosed seven main fractions (I, II, III, IV, V, VI and VII) and the main LAO enzymatic activity was detected in fraction II. The group treated with BiLAO showed a decrease in perfusion pressure (C-120 = 110.28 +/- 3.69; BiLAO(120) = 82.2 +/- 5.6 mmHg*); renal vascular resistance (C-120 = 5.48 +/- 0.53; BiLAO(120) = 4.12 +/- 0.42 mmHg/mL/g/min), urinary flow (C-120 = 0.160 +/- 0.020; BiLAO(120) = 0.064 +/- 0.012 mL/g/min*), glomerular filtration rate (C-120 = 0.697 +/- 0.084; BiLAO(120) = 0.176 +/- 0.017 mL/g/min*), sodium (C-120 = 79.76 +/- 0.56; BiLAO(120) = 65.39 +/- 6.19%*), potassium (C-120 = 69.94 +/- 6.86; BiLAO(120) = 60.26 +/- 2.24%*) and chloride tubular reabsortion (C-120 = 78.53 +/- 2.33; BiLAO(120) = 64.58 +/- 6.68%*). Acute tubular necrosis foci were observed in the group treated with the LAO fraction of the B. insularis snake venom. Some findings have the same morphological aspect of apoptosis, more evident cortically; otherwise, reversible degenerative phenomena represented by hydropic ballooning with extensive cytoplasmic vacuolization and discontinuity of the cell brush borders in the proximal tubular epithelium were observed; furthermore, necrotic detachment of these cells into the tubular lumina, and increased amount of protein deposits in the distal and proximal tubules were observed. In conclusion, the slowness of blood flow and of glomerular filtration resulted in more time for filtration and tubular reabsorption, with elevation of the total percentage of sodium and chlorine reabsorption. The maintenance of the decrease in glomerular filtration rate would determine the subsequent decreases, which were noticed in these parameters. The necrosis observed was the result of damage cell induced by L-amino acid oxidase isolated from B. insularis venom. (c) 2007 Elsevier Ltd. All rights reserved.51219920

Perfil dos pacientes com tuberculose e avaliação do programa nacional de controle da tuberculose em Bagé (RS) Profile of patients with tuberculosis: evaluation of the Brazilian national tuberculosis control program in Bagé, Brazil

OBJETIVO: Realizar um levantamento epidemiológico dos pacientes com diagnóstico de tuberculose, e fatores associados, além de verificar a eficácia do Programa Nacional de Controle da Tuberculose na cidade de Bagé, Rio Grande do Sul. MÉTODOS: Realizou-se um estudo retrospectivo dos casos notificados de tuberculose do Posto Paulo Barcellos, através da revisão de prontuários médicos e dos dados do Sistema Nacional de Agravos de Notificação, entre janeiro de 2001 e dezembro de 2004. RESULTADOS: Neste período, foram realizadas 4.468 baciloscopias, sendo a de escarro a amostra mais numerosa. Resultaram positivas 131 amostras, com prevalência maior do sexo masculino e idade entre 26 e 35 anos, e prevalência menor daqueles com idade acima de 65 anos. Mais de 50% dos pacientes eram da raça branca, tinham apenas 1 a 3 anos de estudo, e exerciam alguma função que lhes garantia algum sustento, com renda mensal baixa (média de 265 reais/mês). Houve equivalência entre os fumantes e não fumantes, e somente um dos 131 casos de tuberculose era HIV positivo. CONCLUSÃO: O número de baciloscopias realizadas em Bagé foi crescente nos últimos quatro anos. Em 2003 e 2004, esse número superou as metas do Programa Nacional de Controle da Tuberculose, o que demonstra a eficácia da busca ativa de casos de tuberculose na cidade, no entanto, houve diminuição de casos novos.<br>OBJECTIVE: To present epidemiological data on patients diagnosed with tuberculosis, as well as on associated factors, and to determine the efficacy of the National Tuberculosis Control Program in Bagé, Brazil. METHODS: A retrospective study was carried out at the Pablo Barcellos Center, analyzing cases of tuberculosis reported from January 2001 to December 2004. Data were collected through the review of clinical charts and from the National Case Registry database. RESULTS: During this period, of the 4468 sputum smear microscopies performed, 131 were positive, with higher prevalence among males aged 26 to 35 years old. Prevalence was lower among those aged 65 and above. Over 50% of the patients were Caucasian, had only 1 to 3 years of schooling and worked in low-income jobs (mean salary, 265 Brazilian reals/month). There was no significant difference between smokers and former smokers/nonsmokers, and only one of the 131 cases was HIV positive. CONCLUSION: The number of sputum smear microscopies performed in Bagé increased in the past four years. In 2003 and 2004, it exceeded the goal of the National Tuberculosis Control Program. However, the number of new cases decreased, demonstrating the efficacy of the active search for tuberculosis cases in the city