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1.
Food Funct ; 12(6): 2631-2643, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33645604

RESUMO

Prostate cancer (PCa) is one of the most common cancers in men, with a huge impact on their health. The use of Castanea sativa Mill. flowers (CFs) in beverages has been reported, through ancestral claims, as having health benefits. In vitro research has evidenced the properties of CFs, such as antitumor and antioxidant activities. This study aimed to evaluate the effects of CF extract in an animal model of PCa. Forty male Wistar Unilever rats were randomly assigned to four groups: control, induced, control + CF, and induced + CF groups. Animals from the induced groups were exposed to a multistep protocol for PCa induction. The CF extract, rich in trigalloyl-HHDP-glucoside and obtained via decoction, was administered to the CF groups in drinking water (3 mg per animal per day) for 49 weeks. Animals were sacrificed at 61 weeks of age. Regarding the effects of CFs on dorsolateral prostate tumorigenesis, no significant differences were observed between the induced and induced + CF groups. However, animals exposed to the CF extract showed fewer inflammation areas on the dorsolateral prostate lobe than those not exposed to CF. Moreover, the CF extract alleviated the hepatic oxidative stress associated with the multistep protocol, resulting in lower levels of lipid peroxidation. These results suggest that CF extract has antioxidant and anti-inflammatory properties.


Assuntos
Antineoplásicos/farmacologia , Fagaceae/química , Flores/química , Extratos Vegetais/farmacologia , Neoplasias da Próstata/metabolismo , Animais , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Neoplasias Experimentais , Estresse Oxidativo/efeitos dos fármacos , Próstata/efeitos dos fármacos , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/patologia , Ratos , Ratos Wistar
2.
Environ Toxicol ; 31(8): 1009-16, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25640707

RESUMO

Trihalomethanes (THMs) are disinfection byproducts found in chlorinated water, and are associated with several different kinds of cancer in human populations and experimental animal models. Metabolism of THMs proceeds through enzymes such as GSTT1 and CYP2E1 and gives rise to reactive intermediates, which form the basis for their toxic activities. The aim of this study was to assess the mitochondrial dysfunction caused by THMs at low levels, and the resulting hepatic histological and biochemical changes in the mouse. Male ICR mice were administered with two THMs: dibromochloromethane (DBCM) and bromodichloromethane (BDCM); once daily, by gavage, to a total of four administrations. Animals were sacrificed four weeks after DBCM and BDCM administrations. Blood biochemistry was performed for alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TB), albumin (Alb), total protein (TP), creatinine, and urea. Animals exposed to DBCM and BDCM showed elevated ALT and TB levels (p < 0.05) as compared with controls. Histological analysis confirmed the presence of vacuolar degenerescence and a multifocal necrotizing hepatitis in 33% of animals (n = 2). Mitochondrial analysis showed that THMs reduced mitochondrial bioenergetic activity (succinate dehydrogenase (SQR), cytochrome c oxidase (COX), and ATP synthase) and increased oxidative stress (glutathione S-transferase (GST)) in hepatic tissues (p < 0.05). These results add detail to the current understanding of the mechanisms underlying THM-induced toxicity, supporting the role of mitochondrial dysfunction and oxidative stress in liver toxicity caused by DBCM and BDCM. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1009-1016, 2016.


Assuntos
Estresse Oxidativo/efeitos dos fármacos , Trialometanos/toxicidade , Poluentes Químicos da Água/toxicidade , Alanina Transaminase/sangue , Animais , Doença Hepática Induzida por Substâncias e Drogas/sangue , Desinfecção , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Purificação da Água
3.
Neuroscience ; 273: 1-11, 2014 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-24814727

RESUMO

Depression is a worldwide disability disease associated with high morbidity and has increased dramatically in the last few years. The differential diagnosis and the definition of an individualized therapy for depression are hampered by the absence of specific biomarkers. The aim of this study was to evaluate the phospholipidomic profile of the brain and myocardium in a mouse model of depression induced by chronic unpredictable stress (CUS). The lipidomic profile was evaluated by thin layer and liquid chromatography and mass spectrometry and lipid oxidation was estimated by FOX II assay. Antioxidant enzyme activity and the oxidized/reduced glutathione (GSH/GSSG) ratio were also evaluated. Results showed that chronic stress affects primarily the lipid profile of the brain, inducing an increase in lipid hydroperoxides, which was not detected in the myocardium. A significant decrease in phosphatidylinositol (PI) and in cardiolipin (CL) relative contents and also oxidation of CL and a significant increase of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were observed in the brain of mice after unpredictable chronic stress conditions. In the myocardium only an increase in PC content was observed. Nevertheless, both organs present a decreased GSH/GSSG ratio when compared to control groups, corroborating the occurrence of oxidative stress. The enzyme activities of catalase (CAT) and superoxide dismutase (SOD) were found to be decreased in the myocardium and increased in the brain, while glutathione reductase (GR) was decreased in the brain. Our results indicate that in a mouse model for studying depression induced by CUS, the modification of the expression of oxidative stress-related enzymes did not prevent lipid oxidation in organs, particularly in the brain. These observations suggest that depression has an impact on the brain lipidome and that further studies are needed to better understand lipids role in depression and to evaluate their potential as future biomarkers.


Assuntos
Encéfalo/metabolismo , Transtorno Depressivo/metabolismo , Miocárdio/metabolismo , Fosfolipídeos/metabolismo , Animais , Cardiolipinas/metabolismo , Catalase/metabolismo , Doença Crônica , Modelos Animais de Doenças , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Glutationa Redutase/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Oxirredução , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilinositóis/metabolismo , Estresse Psicológico , Superóxido Dismutase/metabolismo , Incerteza
4.
Genet Mol Res ; 11(3): 3518-21, 2012 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-23079846

RESUMO

Glossophaga soricina is a widespread Neotropical nectarivorous bat. We characterized 10 microsatellite loci isolated from a shotgun genomic library. We analyzed tissues from wing membrane of 67 individuals collected from two populations of Central Brazil (Brasília and Alto Paraíso). The number of alleles per locus ranged from 2 to 20, and the observed and expected heterozygosities ranged from 0.015 to 0.666 and from 0.016 to 0.915, respectively. The high combined probability of genetic identity (4.369 x 10(-8)) and probability of paternity exclusion (0.996) showed that these microsatellite loci would be useful for population genetic structure and parentage studies in natural populations of G. soricina.


Assuntos
Quirópteros/genética , DNA/genética , DNA/isolamento & purificação , Loci Gênicos/genética , Repetições de Microssatélites/genética , Língua , Animais
5.
Genet Mol Res ; 10(4): 3783-93, 2011 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-22183948

RESUMO

The microbiota of the Amazon River basin has been little studied. We compared the structure of bacterial communities of the Solimões and Negro Rivers, the main Amazon River tributaries, based on analysis of 16S rRNA gene sequences. Water was sampled with a 3-L Van Dorn collection bottle; samples were collected at nine different points/depths totaling 27 L of water from each river. Total DNA was extracted from biomass retained by a 0.22-µm filter after sequential filtration of the water through 0.8- and 0.22-µm filters. The 16S rRNA gene was amplified by PCR, cloned and sequenced, and the sequences were analyzed with the PHYLIP and DOTUR programs to obtain the operational taxonomic units (OTUs) and to calculate the diversity and richness indices using the SPADE program. Taxonomic affiliation was determined using the naive Bayesian rRNA Classifier of the RDP II (Ribosomal Database Project). We recovered 158 sequences from the Solimões River grouped into 103 OTUs, and 197 sequences from the Negro River library grouped into 90 OTUs by the DOTUR program. The Solimões River was found to have a greater diversity of bacterial genera, and greater estimated richness of 446 OTUs, compared with 242 OTUs from the Negro River, as calculated by ACE estimator. The Negro River has less bacterial diversity, but more 16S rRNA gene sequences belonging to the bacterial genus Polynucleobacter were detected; 56 sequences from this genus were found (about 30% of the total sequences). We suggest that a more in-depth investigation be made to elucidate the role played by these bacteria in the river environment. These differences in bacterial diversity between Solimões and Negro Rivers could be explained by differences in organic matter content and pH of the rivers.


Assuntos
Bactérias/genética , Genes Bacterianos/genética , Genes de RNAr/genética , RNA Ribossômico/genética , Subunidades Ribossômicas Menores de Bactérias/genética , Rios/microbiologia , Bactérias/classificação , Sequência de Bases , Brasil , Biblioteca Gênica
6.
Food Chem Toxicol ; 49(9): 1989-97, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21609751

RESUMO

Virtually ever since it was first commercialized in 1995, there have been several studies focusing on the use of olive leaf extract (OLE) as a natural therapy and its medical properties. The aim of this study was to investigate the effects of three different concentrations of OLE on the function of mice livers over the course of 14 weeks. Female ICR mice were divided into four groups, depending on OLE concentration used: 0%, 0.25%, 0.5%, and 0.75%. Alanine aminotransferase, alkaline phosphatase, total bilirubin and albumin serum concentrations were all measured. Histopathological changes of the liver were observed after haematoxylin and eosin, reticulin, and Masson's trichrome staining was carried out while liver mitochondrial bioenergetics were also evaluated. Alanine aminotransferase and alkaline phosphatase serum enzyme activities increased significantly in the groups in which 0.5% and 0.75% OLE concentrations were used. Histologically, all the groups exposed to OLE exhibited hyperplasia of the bile ducts, cholestasis, hepatocyte necrosis and inflammatory infiltrated. Hepatic fibrosis was observed in the groups featuring 0.5% and 0.75% OLE concentrations. The mitochondrial membrane potential, respiratory control ratio and ADP/O of samples from animals fed the higher OLE concentration was significantly decreased when compared to the control group.


Assuntos
Fígado/efeitos dos fármacos , Olea/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Animais , Relação Dose-Resposta a Droga , Feminino , Camundongos , Camundongos Endogâmicos ICR
7.
Genet Mol Res ; 10(1): 321-5, 2011 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-21365547

RESUMO

We isolated and characterized 12 microsatellite loci for Tibouchina papyrus (Melastomataceae), an endangered species with narrow and disjunct range, endemics to a few localities in "cerrado rupestre" from Central Brazil. These microsatellites were obtained by sequencing of a genomic shotgun library for primer design. Leaves from 96 individuals collected in the three known local populations were genotyped using the 12 primers designed to analyze the polymorphisms at each locus. The number of alleles per locus ranged from one to six; two loci were monomorphic. Among the polymorphic loci, expected heterozygosities ranged from 0.161 to 0.714. Combined paternity exclusion probability was 0.957 and combined genetic identity (0.051) was high for studies on parentage. Tibouchina papyrus is a rare and endemic tree species of outcrop quartzite and sandstone soils, with highly isolated populations, which may have lead to the low degree of polymorphism that we detected. Also, motifs of most loci are larger than dinucleotide, which typically display lower levels of polymorphism.


Assuntos
Melastomataceae/genética , Repetições de Microssatélites/genética , Espécies em Perigo de Extinção , Polimorfismo Genético/genética
8.
Arq. bras. med. vet. zootec ; 61(2): 386-392, abr. 2009. graf, tab
Artigo em Português | LILACS | ID: lil-518715

RESUMO

Descreve-se um método de isolamento de mitocôndrias acopladas de tilápia-do-nilo Oreochromis niloticus, isoladas de células hepáticas de peixes adultos. As mitocôndrias estavam metabolicamente ativas, sendo capazes de realizarem fosforilação oxidativa, de acordo com os valores do quociente de controle respiratório. Os valores de controle respiratório obtidos com malato/piruvato (complexo I) e com succinato (complexo II) foram de 5,8±0,8 e 3,38±0,4, respectivamente. O potencial de membrana exibiu o valor de 197±4mV, quer se utilizasse malato/piruvato ou succinato como substrato. O procedimento de isolamento de mitocôndrias de O. niloticus permite o estudo do efeito de xenobióticos na bioenergética mitocondrial, tendo sido avaliada a ação da oxifluorfena (0,6mgL-1) na bioenergética mitocondrial. Os resultados demonstram que o tratamento com oxifluorfena influencia a capacidade fosforilativa dos peixes, interferindo na sua carga energética, o que poderá levar à sua morte.


A method for isolation of coupled mitochondria isolated from the liver of adult Nile tilapia Oreochromis niloticus is described for the first time. They were metabolically active, able to sustain oxidative phosphorylation, as shown by respiratory control ratio values, which were about 5.8±0.8 and 3.3±0.4 when respiring on malate/piruvate (complex I) or succinate (complex II), respectively, as substrate. Membrane potential exhibited a value of approximately 197±4mV for malate/piruvate or succinate. The procedure now described for the isolation of O. niloticus mitochondria is an important new tool, allowing the study about the effect of xenobiotics on mitochondrial bioenergetic, being evaluated the effect of oxyfluorfen (0.6mgL-1) in the liver mitocondrial bioenergetic. These results showed that phosphorylation was significantly affected by oxyfluorfen which contributed to the decrease on the liver cell energy charge and consequently led to the fish dead.


Assuntos
Animais , Ciclídeos , Metabolismo Energético , Herbicidas/efeitos adversos , Fígado , Mitocôndrias/metabolismo
9.
Ecotoxicol Environ Saf ; 70(2): 266-75, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18262649

RESUMO

In a previous work the ability of Candida oleophila to use phenolic compounds as sole carbon and energy source at high concentrations without an additional carbon source was reported. C. oleophila grown in bioreactor batch cultures in a diluted and sterilized olive oil mill wastewater (OMW) caused a significant decrease in the total tannins content but no significant alteration was observed in phenolic acid and fatty acid content. Both treated and untreated OMWs were tested to evaluate the capacity in interfering with mitochondrial bioenergetics. Mitochondrial respiration was not affected by treated OMW on the range of used concentrations, contrary to the untreated OMW. Furthermore, mitochondrial membrane potential and respiratory complexes were always significantly less affected by treated OMW in comparison with untreated OMW. However, supplementary treatment should be applied before OMW could be considered non-toxic.


Assuntos
Candida/metabolismo , Resíduos Industriais , Mitocôndrias/fisiologia , Óleos de Plantas , Eliminação de Resíduos Líquidos/métodos , Adenosina Trifosfatases/metabolismo , Animais , Biodegradação Ambiental , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Metabolismo Energético , Ácidos Graxos/análise , Indústria de Processamento de Alimentos , Fígado/metabolismo , Potencial da Membrana Mitocondrial , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Dilatação Mitocondrial , Azeite de Oliva , Oxigênio/metabolismo , Fenóis/metabolismo , Ratos , Ratos Wistar , Succinato Citocromo c Oxirredutase/metabolismo , Succinato Desidrogenase/metabolismo , Taninos/metabolismo
10.
Ecotoxicol Environ Saf ; 69(3): 480-7, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17659777

RESUMO

Acute toxicity of olive mill wastewaters (OMW), collected from a continuous olive mill, was evaluated in rat liver mitochondrial bioenergetics. Inhibition of respiratory activities in state 4, state 3, and uncoupled respiration are essentially mediated through partial inhibitions of mitochondrial complexes II and III. ATPase activity was considerably less depressed by OMW than ATP synthase activity (a difference of 42%). The inhibition observed on ATP synthase is mostly the result of an inhibition on the redox complexes. Ultimately, the OMW-induced loss of phosphorylation capacity was not only the result of a direct effect of OMW on the enzymatic complex (F(0)-F(1) ATPase), but also the result of a deleterious effect on the integrity of the mitochondrial membrane, which can promote an inhibition of the respiratory complexes and an increase of the proton permeability of the inner membrane.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Resíduos Industriais/efeitos adversos , Mitocôndrias Hepáticas/fisiologia , Consumo de Oxigênio/efeitos dos fármacos , Óleos de Plantas , Desacopladores/toxicidade , Eliminação de Resíduos Líquidos , Animais , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/fisiologia , Cinética , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Azeite de Oliva , Portugal , Ratos , Ratos Wistar
11.
J Appl Toxicol ; 28(1): 55-62, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17461434

RESUMO

Microcystins (MCs) are a group of closely related cyclic heptapeptides produced by a variety of common cyanobacteria. These toxins have been implicated in both human and livestock mortality. Microcystin-LR could affect renal physiology by altering vascular, glomerular and urinary parameters, indicating that MC-LR could act directly on the kidney. The aim of the current work was to examine the effect of MC-LR on mitochondrial oxidative phosphorylation of rat kidney isolated mitochondria.Furthermore, microcystin-LR decreased both state 3 and carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP)-uncoupled respiration. The transmembrane potential was strongly depressed by MC-LR in a concentration dependent manner, pointing to an uncoupling effect; however, microcystin-LR did not increase the permeability of the inner mitochondria membrane to protons. Therefore, the transmembrane decrease was a consequence of a strong inhibitory effect on redox complexes. The addition of uncoupling concentrations of MC-LR to Ca(2+)-loaded mitochondria treated with ruthenium red resulted in mitochondrial permeability transition pore (MPTP) opening, as evidenced by mitochondrial swelling in isosmotic sucrose medium. Mitochondrial swelling in the presence of Ca(2+) was prevented by cyclosporin A and was drastically inhibited by catalase and dithiothreitol, indicating the participation of mitochondrial generated reactive oxygen species in this process. From this study it can be concluded that the bioenergetic lesion promoted by microcystin-LR seems to be sufficient to explain renal injury.


Assuntos
Nefropatias/metabolismo , Microcistinas/toxicidade , Mitocôndrias/efeitos dos fármacos , Adenosina Trifosfatases/metabolismo , Animais , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Nefropatias/induzido quimicamente , Nefropatias/fisiopatologia , Masculino , Toxinas Marinhas , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/fisiologia , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Dilatação Mitocondrial/efeitos dos fármacos , Ratos , Ratos Wistar , Succinato Citocromo c Oxirredutase/metabolismo , Succinato Desidrogenase/metabolismo
12.
Genet Mol Res ; 6(4): 756-65, 2007 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-18058703

RESUMO

The production of nucleic acid sequences by automatic DNA sequencer machines is always associated with some base-calling errors. In order to produce a high-quality DNA sequence from a molecule of interest, researchers normally sequence the same sample many times. Considering base-calling errors as rare events, re-sequencing the same molecule and assembling the reads produced are frequently thought to be a good way to generate reliable sequences. However, a relevant question on this issue is: how many times the sample needs to be re-sequenced to minimize costs and achieve a high-fidelity sequence? We examined how both the number of re-sequenced reads and PHRED trimming parameters affect the accuracy and size of final consensus sequences. Hundreds of single-pool reaction pUC18 reads were generated and assembled into consensus sequences with CAP3 software. Using local alignment against the published pUC18 cloning vector sequence, the position and number of errors in the consensus were identified and stored in MySQL databases. Stringent PHRED trimming parameters proved to be efficient for the reduction of errors; however, this procedure also decreased consensus size. Moreover, re-sequencing did not have a clear effect on the removal of consensus errors, although it was able to slightly increase consensus.


Assuntos
Sequência Consenso , Análise de Sequência de DNA/métodos , Pareamento Incorreto de Bases , Sequência de Bases , Plasmídeos/genética
13.
Acta Diabetol ; 44(3): 121-30, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17721750

RESUMO

We investigated the effect of sub-chronic soybean oil (SO) treatment on the insulin secretion and fatty acid composition of islets of Langerhans obtained from Goto-Kakizaki (GK), a model of type 2 diabetes, and normal Wistar rats. We observed that soybean-treated Wistar rats present insulin resistance and defective islet insulin secretion when compared with untreated Wistar rats. The decrease in insulin secretion occurred at all concentrations of glucose and arginine tested. Furthermore we observed that soybean-treated normal islets present a significant decrease in two saturated fatty acids, myristic and heneicosanoic acids, and one monounsaturated eicosenoic acid, and the appearance of the monounsaturated erucic acid. Concerning diabetic animals, we observed that soybean-treated diabetic rats, when compared with untreated GK rats, present an increase in plasma non-fasting free fatty acids, an exacerbation of islet insulin secretion impairment in all conditions tested and a significant decrease in the monounsaturated palmitoleic acid. Altogether our results show that SO treatment results in a decrease of insulin secretion and alterations on fatty acid composition in normal and diabetic islets. Furthermore, the impairment of insulin secretion, islet erucic acid and fasting plasma insulin levels are similar in treated normal and untreated diabetic rats, suggesting that SO could have a deleterious effect on beta-cell function and insulin sensitivity.


Assuntos
Glucose/farmacologia , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Óleo de Soja/farmacologia , Animais , Arginina/farmacologia , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Modelos Animais de Doenças , Ácidos Graxos/metabolismo , Feminino , Secreção de Insulina , Ilhotas Pancreáticas/efeitos dos fármacos , Ácido Mirístico/metabolismo , Ratos , Ratos Endogâmicos , Valores de Referência
14.
Ecotoxicol Environ Saf ; 66(3): 426-31, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16620977

RESUMO

Heavy metal (Cu and Zn) concentrations in liver, gills, and muscle of leaping grey mullet, Liza saliens, from the Portuguese Esmoriz-Paramos coastal lagoon were measured to evaluate their bioaccumulation as a function of sediment contamination. The highest metal concentrations were observed in the liver (254 mg Cu kg(-1)) and gills (114 mg Zn kg(-1)). Bioaccumulation factors (BAFs) were found to follow the order: Cu-liver>Cu-gills>Cu-muscle and Zn-gills>Zn-liver>Zn-muscle. The highest BAFs were observed in the organs mainly implicated in metal metabolism and a significant positive relationship was found between BAFs and fish age. These results suggest the loss of homeostatic capacity of L. saliens under chronic metal exposure leading to bioaccumulation. Furthermore, Cu-liver and Zn-gills accumulation can be good environmental indicators of metal stress in L. saliens.


Assuntos
Cobre/metabolismo , Smegmamorpha/metabolismo , Poluentes Químicos da Água/metabolismo , Zinco/metabolismo , Animais , Monitoramento Ambiental , Sedimentos Geológicos/análise , Brânquias/metabolismo , Fígado/metabolismo , Músculos/metabolismo , Portugal , Água do Mar
15.
Genet. mol. res. (Online) ; 6(4): 756-765, 2007. ilus, graf
Artigo em Inglês | LILACS | ID: lil-520066

RESUMO

The production of nucleic acid sequences by automatic DNA sequencer machines is always associated with some base-calling errors. In order to produce a high-quality DNA sequence from a molecule of interest, researchers normally sequence the same sample many times. Considering base-calling errors as rare events, re-sequencing the same molecule and assembling the reads produced are frequently thought to be a good way to generate reliable sequences. However, a relevant question on this issue is: how many times the sample needs to be re-sequenced to minimize costs and achieve a high-fidelity sequence? We examined how both the number of re-sequenced reads and PHRED trimming parameters affect the accuracy and size of final consensus sequences. Hundreds of single-pool reaction pUC18 reads were generated and assembled into consensus sequences with CAP3 software. Using local alignment against the published pUC18 cloning vector sequence, the position and number of errors in the consensus were identified and stored in MySQL databases. Stringent PHRED trimming parameters proved to be efficient for the reduction of errors; however, this procedure also decreased consensus size. Moreover, re-sequencing did not have a clear effect on the removal of consensus errors, although it was able to slightly increase consensus.


Assuntos
Análise de Sequência de DNA/métodos , Sequência Consenso , Pareamento Incorreto de Bases , Sequência de Bases , Plasmídeos/genética
16.
J Biochem Mol Toxicol ; 15(6): 322-30, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11835632

RESUMO

Paraquat herbicide is toxic to animals, including humans, via putative toxicity mechanisms associated to microsomal and mitochondrial redox systems. It is also believed to act in plants by generating highly reactive oxygen free radicals from electrons of photosystem I on exposure to light. Paraquat also acts on non-chlorophyllous plant tissues, where mitochondria are candidate targets, as in animal tissues. Therefore, we compared the interaction of paraquat with the mitochondrial bioenergetics of potato tuber, using rat liver mitochondria as a reference. Paraquat depressed succinate-dependent mitochondrial Delta(psi), with simultaneous stimulation of state 4 O2 consumption. It also induced a slow time-dependent effect for respiration of succinate, exogenous NADH, and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD)/ascorbate, which was more pronounced in rat than in potato mitochondria. However, with potato tuber mitochondria, the Delta(psi) promoted by complex-I-dependent respiration is insensitive to this effect, indicating a protection against paraquat radical afforded by complex I redox activity, which was just the reverse of to the findings for rat liver mitochondria. The experimental set up with the tetraphenyl phosphonium (TPP+)-electrode also indicated production of the paraquat radical in mitochondria, also suggesting its accessibility to the outside space. The different activities of protective antioxidant agents can contribute to explain the different sensitivities of both kinds of mitochondria. Values of SOD activity and alpha-tocopherol detected in potato mitochondria were significantly higher than in rat mitochondria, which, in turn, revealed higher values of lipid peroxidation induced by paraquat.


Assuntos
Herbicidas/farmacologia , Mitocôndrias/efeitos dos fármacos , Paraquat/toxicidade , Solanum tuberosum/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Ratos , Solanum tuberosum/enzimologia , Solanum tuberosum/metabolismo , Ácido Succínico/metabolismo , Superóxido Dismutase/metabolismo , alfa-Tocoferol/metabolismo
17.
Arch Microbiol ; 171(1): 6-12, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9871013

RESUMO

Cells of Saccharomyces cerevisiae exhibited a more active plasma membrane H+-ATPase during growth in media supplemented with CuSO4 concentrations equal to or below 1 mM than did cells cultivated in the absence of copper stress. Maximal specific activities were found with 0.5 mM CuSO4. ATPase activity declined when cells were grown with higher concentrations up to 1.5 mM (the maximal concentration that allowed growth), probably due to severe disorganization of plasma membrane. Cu2+-induced maximal activation was reflected in an increase of Vmax (approximately threefold) and in the slight decrease of the Km for MgATP (from 0.93 +/- 0.13 to 0.65 +/- 0.16 mM). The expression of the gene encoding the essential plasma membrane ATPase (PMA1) was reduced with a dose-dependent pattern in cells grown with Inhibitory concentrations of copper, while the weakly expressed PMA2 gene promoter was moderately more efficient in cells cultivated under mild copper stress (1.5-fold maximal activation). ATPase was activated by copper despite the slightly lower content of ATPase protein in the plasma membrane of Cu2+-grown cells and the powerful inhibitory effect of Cu2+ in vitro.


Assuntos
Adenosina Trifosfatases/metabolismo , Cobre/farmacologia , Proteínas Fúngicas/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/efeitos dos fármacos , Western Blotting , Meios de Cultura/química , Ativação Enzimática , Isoenzimas/metabolismo , ATPases Translocadoras de Prótons/genética , ATPases Translocadoras de Prótons/metabolismo , Saccharomyces cerevisiae/fisiologia
18.
Rev. Hosp. Clin. Fac. Med. Univ. Säo Paulo ; 49(5): 225-7, set.-out. 1994. ilus, tab
Artigo em Português | LILACS | ID: lil-154392

RESUMO

Os autores avaliam o desempenho dos alunos nas provas teoricas, quantidade de horas de estudo em livros textos, frequencia a aulas e seminarios e opiniao dos alunos a cerca de cada area onde se desenvolve o internato de clinica medica do sexto ano da FMUSP oferecido no Hospital Universitario da USP. Observou-se uma tendencia a piora no desempenho nas provas teoricas, quando as questoes eram baseadas num guia de estudo. A media de horas de estudos em livros foi texto de 5,8 +/- 0,3 horas/semana. Houve um aumento de frequencia as aulas e seminarios de 10 a 23 por cento para 72 por cento. E uma melhor avaliacao pelos alunos nas areas de emrgencia (PS e UTI).


Assuntos
Avaliação Educacional/normas , Educação Médica , Internato e Residência/organização & administração , Internato e Residência/normas
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