Mutagenic activity promoted by amentoflavone and methanolic extract of Byrsonima crassa Niedenzu

Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains 100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9). (c) 2006 Elsevier B.V.. All rights reserved

Parallel hyperspectral compressive sensing method on GPU

Remote hyperspectral sensors collect large amounts of data per flight usually with low spatial resolution. It is known that the bandwidth connection between the satellite/airborne platform and the ground station is reduced, thus a compression onboard method is desirable to reduce the amount of data to be transmitted. This paper presents a parallel implementation of an compressive sensing method, called parallel hyperspectral coded aperture (P-HYCA), for graphics processing units (GPU) using the compute unified device architecture (CUDA). This method takes into account two main properties of hyperspectral dataset, namely the high correlation existing among the spectral bands and the generally low number of endmembers needed to explain the data, which largely reduces the number of measurements necessary to correctly reconstruct the original data. Experimental results conducted using synthetic and real hyperspectral datasets on two different GPU architectures by NVIDIA: GeForce GTX 590 and GeForce GTX TITAN, reveal that the use of GPUs can provide real-time compressive sensing performance. The achieved speedup is up to 20 times when compared with the processing time of HYCA running on one core of the Intel i7-2600 CPU (3.4GHz), with 16 Gbyte memory

Inserção das ciências básicas no currículo integrado do curso de Medicina da Universidade Estadual de Londrina

O curso de Medicina da Universidade Estadual de Londrina (UEL) implementou um currículo integrado que utiliza a metodologia da Aprendizagem Baseada em Problemas (ABP) nos módulos temáticos. Embora dados da literatura apontem que o uso dessa metodologia aumenta o entendimento e a retenção de conceitos das ciências básicas, alguns autores demonstram preocupação com o fato de estas não receberem suficiente ênfase nesta metodologia. Esse trabalho teve por objetivo avaliar a inserção das ciências básicas no currículo integrado do curso de Medicina da UEL. Para isto, foi elaborado um questionário semiestruturado sobre o processo de inclusão dos docentes das áreas básicas nas várias atividades desenvolvidas no atual currículo. Houve aumento de 36% na participação dos docentes em relação ao currículo anterior. Foi verificado que ocorreu uma distribuição dos docentes em atividades do currículo integrado nas quatro primeiras séries, embora com maior concentração nas duas primeiras. Devem ser feitos esforços para que a integração básico-clínico possa ocorrer com maior intensidade em todas as séries

Mutagenicity and genotoxicity of isatin in mammalian cells in vivo

Isatin (1H-indole-2,3-dione) is a synthetically versatile substrate used for the synthesis of heterocyclic compounds and as a raw material for drug synthesis. Isatin and its derivatives demonstrate anticonvulsant, antibacterial, antifungal, antiviral, and anticancer properties. We evaluated the genotoxic and mutagenic effects of acute (24h) and repeated (14d) exposure to isatin in vivo. using the cornet assay and the micronucleus test. Three doses (50, 100, and 150 mg/kg b.w.) were administered to mice via gayage. Doses were selected according to the LD(50) of isatin, estimated in a preliminary test to be 1 g/kg b.w. To evaluate the results, parametric (ANOVA/Tukey) and non-parametric (Kruskal-Wallis/Dunn's post hoc test) tests were used, according to the nature of the data distribution. At all doses (50, 100 and 150 mg/kg b.w.), after acute treatment with isatin, alterations in DNA migration (comet assay) were not observed and mutagenic effects were not seen (micronucleus test on peripheral blood cells). After repeated doses, only the highest dose of isatin (150 mg/kg b.w.) induced alterations in the DNA that gave rise to micronuclei in the bone marrow and peripheral blood cells of the mice. Our results show that the mutagenic and genotoxic effects of isatin depend on dose and on period of exposure. (C) 2010 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Assessment of DNA damage induced by extracts, fractions and isolated compounds of Davilla nitida and Davilla elliptica (Dilleniaceae)

Davilla nitida and Davilla elliptica (Dilleniaceae) are plants that occur predominantly in the cerrado region of South America. They are used in popular medicine to treat stomach diseases, diarrhea and swelling, particularly of the lymph nodes and testicles. Chemical investigation of these two plant species led to the identification of the compounds myricetin-3-O-alpha-L-rhamnoside (myricitrin), quercetin-3-O-alpha-rhamnoside (quercitrin), myricetin, quercetin and gallic acid derivatives in the leaves of D. nitida and D. elliptica. Therefore, it was concluded that the two species of Davilla possess qualitatively similar chemical profiles. In the present study, the mutagenic and genotoxic potential of these plants and of their isolated compounds was tested in the Salmonella typhimurium assay (Ames test) with strains TA100,TA98,TA102 and TA97a, in the micronucleus test with peripheral blood cells of mice treated in vivo, and in plasmid DNA to analyze DNA strand-breaks. In the assessment of mutagenic potential by the Ames test, extracts from both plant species and a D. nitida ethyl-acetate fraction induced positive responses. on the other hand, none of the extracts showed genotoxic activity in the mouse cells. In the presence of metal ion, D. nitida and D. elliptica aqueous and ethyl-acetate fractions, as well as their isolated compounds, induced single- and double-strand-breaks in plasmid DNA in a cell-free system. (C) 2010 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Polymorphisms in glutathione-related genes modify mercury concentrations and antioxidant status in subjects environmentally exposed to methylmercury

Methylmercury (MeHg) toxicity may vary widely despite similar levels of exposure. This is hypothetically related to genetic differences in enzymes metabolizing MeHg. MeHg causes oxidative stress in experimental models but little is known about its effects on humans. The aims of the present study was to evaluate the effects of polymorphisms in glutathione (GSH)-related genes (GSTM1, GSTT1, GSTP1 and GCLM) on Hg concentrations in blood and hair, as well as MeHg-related effects on catalase (CAT) and glutathione-peroxidase (GPx) activity and GSH concentrations. Study subjects were from an Amazonian population in Brazil chronically exposed to MeHg from fish. Hg in blood and hair were determined by ICP-MS, CAT, GPx and GSH were determined by spectrophotometry, and multiplex PCR (GSTM1 and GSTT1) and TagMan assays (GSTP1 and GCLM) were used for genotyping. Mean Hg concentrations in blood and hair were 48 +/- 36 mu g/L and 14 +/- 10 mu g/g. Persons with the GCLM-588 IT genotype had lower blood and hair Hg than did C-allele carriers (linear regression for Hg in blood beta = -0.32, p = 0.017; and hair beta = -0.33; p = 0.0090; adjusted for fish intake, age and gender). GSTM1*0 homozygous had higher blood (beta = 0.20; p = 0.017) and hair Hg (hair beta = 0.20; p = 0.013). Exposure to MeHg altered antioxidant status (CAT:beta = -0.086; GSH:beta = -0.12; GPx:beta = -0.16; all p < 0.010; adjusted for gender, age and smoking). Persons with GSTM1*0 had higher CAT activity in the blood than those with GSTM1. Our data thus indicate that some GSH-related polymorphisms, such as GSTM1 and GCLM may modify MeHg metabolism and Hg-related antioxidant effects. (C) 2013 Elsevier BY. All rights reserved

Comprehensive genome methylation and whole genome expression analysis in penile carcinoma: Uncovering new molecular markers

Background: Penile carcinoma (PeCa) is frequently associated with high morbidity rates. Unlikely of the vast majority of tumors, there is no molecular markers described that are able to assist in diagnosis and prognosis or with potential to be therapeutic targets in PeCa. Patients and methods: DNA methylation status (244K Human DNA Methylation Microarray platform, Agilent Technologies) and large-scale expression analysis (4x44K Whole Human Genome Microarray, Agilent Technologies) were performed in 35 and 37 PeCa, respectively. Quantitative bisulfite pyrosequencing (qBP) and RT-qPCR were used to validate the findings in 93 samples. HPV status was assessed using the Linear Array HPV Genotyping kit (Roche Molecular Diagnostics, CA, USA). Results: Methylome analysis revealed 171 hypermethylated and 449 hypomethylated CpGs sites and the transcriptome profiling showed 2986 down- and 2817 over-expressed genes. HPV positivity was found in 32.7% of the cases, mainly the HPV16. The integrative analysis in 32 PeCa revealed a panel of 96 genes with inverse correlation between methylation and gene expression levels. The CpG hypermetlylation and gene downexpression, was confirmed for TWIST1, RSOP2, SOX3, SOX17, CD133, OTX2, HOXA3 and MEIS. In addition, BIRC5, DNMT1 and DNMT3B presented low levels of methylation and overexpression. The comparison of the results with clinical findings revealed that LIN28A, NKX2.2, NKX2.3, LHX5, BDNF, FOXA1 and CDX2 were associated with poor prognosis features. Conclusion: Putative prognostic markers were detected revealing that DNA methylation modulates the expression of several genes in PeCa. These data may prove instrumental for biomarker discovery in clinics and molecular epidemiology of PeCa

Imunohistochemistry: detection of microcystin in tilápia exposed to Microcystis aeruginosa (Cyanobacteria) extract

A deterioração da qualidade de água pela piscicultura associa-se à eutrofização, com florescimento de cianobactérias. Microcystis aeruginosa destaca-se como principal produtora de microcistinas (MCs), grupo de hepatotoxinas com potencial promotor de tumor. No presente trabalho desenvolveu-se método imunoistoquímico para a detecção de MC em tilápias (Oreochromis niloticus) submetidas à injeção intraperitoneal (i.p.) ou imersão em extrato de M. aeruginosa BCCBUSP 262, empregando anticorpo monoclonal anti-MC (M8H5) e sistema polímero-peroxidase. As tilápias (N=42) foram submetidas a sete tratamentos, sendo três grupos inoculados i.p. com 2,0x105, 4,0x105 e 1,0x106 cels.Kg-1 de M. aeruginosa BCCBUSP 262 e quatro submetidos à imersão em diferentes concentrações do extrato da cianobactéria (variando de 1,0x104 a 1,0x105cel.mL-1). Analisando fígado e tecido muscular pelo ensaio imunoistoquímico, não se detectou marcação em tecido muscular. Todos os animais inoculados i.p. apresentaram marcação positiva para MC no fígado, mas em teste de imersão, apenas os expostos a maior dose (1,0x105 cels.mL-1) apresentaram marcação positiva. Embora MC não seja detectada em tecido muscular, assim como no fígado de animais imersos em extrato de M. aeruginosa CCBUSP 262 em concentrações menores que 1,0x105 cels.mL-1, os resultados constituíram-se base para o desenvolvimento metodológico objetivando a aplicação da imunoistoquímica no diagnóstico rápido no controle de qualidade de pescados.The deterioration of the water quality due to aquaculture is associated with eutrophication, with bloom of cyanobacteria. Microcystis aeruginosa is distinguished as main producer of microcystins (MCs), group of hepatotoxins with tumor promoter potential. In the present work immunohistochemical method for detection of MC in tilápia (Oreochromis niloticus), fish submitted to intraperitoneal injection (i.p.) or immersion in extract of M. aeruginosa BCCBUSP 262 was developed, using monoclonal antibody anti - MC (M8H5) and polymer peroxidase system. The tilápias (N=42) had been submitted to the seven treatments, three groups inoculated i.p. with 2.0x105, 4.0x105 and 1.0x106 cells. Kg-1 of M. aeruginosa BCCBUSP 262 and four groups exposed to the immersion in different extract concentrations of cyanobacterium. Analyzing liver and muscular tissue for immunohistochemical assay, muscular tissue was not stained. All the animals inoculated i.p. presented positive marking for MC in the liver, but in immersion test, only the ones exposed in the highest dose (1,0x105 cels.mL-1) presented positive marking. Although MC was not detected in muscular tissue, as well as in the liver of animals immersed in extract of M. aeruginosa BCCBUSP 262 in concentrations less than 1.0x105 cels.mL-1, the results would constitute in the base for the methodological development aiming the application of the immunohistochemistry in the rapid diagnosis in quality control of fish