Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Insect Mol Biol ; 31(1): 49-59, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34478211

RESUMO

Control of Chagas disease in endemic countries is primarily accomplished through insecticide spraying for triatomine vectors. In this context, pyrethroids are the first-choice insecticide, and the evolution of insect resistance to these insecticides may represent an important barrier to triatomine control. In insects, cytochrome P450s are enzymes involved in the metabolism of xenobiotics and endogenous chemicals that are encoded by genes divided into different families. In this work, we evaluated the role of three Rhodnius prolixus CYP4EM subfamily genes during blood meal and after deltamethrin exposure. CYP4 gene members were expressed in different insect organs (integument, salivary glands (SGs), midgut, fat body and malpighian tubules) at distinct transcriptional levels. CYP4EM1 gene was highly expressed in the SG and was clearly modulated after insect blood meal. Injection of CYP4EM1dsRNA promoted significant reduction in mRNA levels of both CYP4EM1 and CYP4EM2 genes and induced deleterious effects in R. prolixus nymphs subsequently exposed to sublethal doses of deltamethrin (3.4 or 3.8 ng/nymph treated). The higher dose reduced the survival over time and increased susceptibility of R. prolixus nymphs to deltamethrin. A better understanding of this mechanism can help in developing of more efficient strategies to reduce Trypanosoma cruzi vector transmission in Americas.


Assuntos
Doença de Chagas , Inseticidas , Rhodnius , Animais , Doença de Chagas/genética , Doença de Chagas/prevenção & controle , Inativação Gênica , Humanos , Insetos Vetores/genética , Inseticidas/farmacologia , Longevidade , Nitrilas , Ninfa/genética , Piretrinas , Rhodnius/genética
2.
Bull Entomol Res ; 107(4): 527-533, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28112063

RESUMO

The aim of this study was to evaluate the effects of silicon application and administration of the phytohormone gibberellic acid on resistance of the corn plants to the fall armyworm (FAW), Spodoptera frugiperda, and their vegetative characteristics. We evaluated larval and pupal duration, survival and biomass, and adult longevity, malformation and fecundity of S. frugiperda after feeding on plant matter treated with silicon and/or gibberellic acid. The feeding preference of FAW first-instar larvae, the total leaf area consumed by the insects, and the vegetative parameters of corn plants were also evaluated. No significant differences were observed in the measured parameters of larval and pupal stages of S. frugiperda in response to silicon or gibberellic acid. In adult stage insects, the number of eggs per female was significantly reduced in insects derived from larvae fed plants treated with silicon or gibberellic acid. In a non-preference test, 48 h after release, caterpillars preferred control untreated plants and consumed less matter from plants that had received hormonal treatment (gibberellic acid). Gibberellic acid also altered the vegetative characteristics of plants, by increasing their height, shoot fresh and dry mass, and silicon content. We conclude that gibberellic acid can alter the vegetative characteristics and silicon uptake of corn plants, leading to a reduction in their consumption by S. frugiperda larvae and a decrease in female insect oviposition.


Assuntos
Preferências Alimentares/efeitos dos fármacos , Giberelinas/farmacologia , Silício/farmacologia , Spodoptera/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Animais , Feminino , Larva/efeitos dos fármacos , Oviposição/efeitos dos fármacos
3.
Int J Sports Med ; 35(9): 772-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24771131

RESUMO

The autonomic nervous system (ANS) has an important role in physical performance. However, the cardiac ANS activity in high-level track and field athletes has been poorly explored. Thus, we tested the hypothesis that endurance and power athletes would present a markedly different cardiac autonomic control at rest. We analyzed the cardiac ANS by means of time and frequency domains heart rate variability (HRV) analyses and by symbolic analysis. Endurance athletes showed higher pulse interval than power athletes (1,265±126 vs. 1,031±98 ms respectively; p<0.05). No differences were found in time and frequency domains between the groups. However, the LF%, HF% and LF/HF ratio presented high effect sizes (1.46, 1.46 and 1.30, respectively). The symbolic analysis revealed that endurance athletes had higher 2V parasympathetic modulation (36±6.5) than power athletes (24±9.3; p<0.05). A reduced 0V sympathetic modulation was observed in endurance athletes (21±9.9) compared to power athletes (33±11; p<0.05 and ES=1.30). Our results suggest greater parasympathetic modulation and less sympathetic modulation in endurance athletes compared to power athletes. Additionally, the type of HRV analysis needs to be chosen with well-defined criteria and caution because their use in assessing cardiac autonomic modulation can interfere with the interpretation of results. In practical terms, symbolic analysis appears to better discriminate between cardiac autonomic activities of athletes with different training backgrounds than frequency domain analysis.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Frequência Cardíaca/fisiologia , Coração/fisiologia , Resistência Física/fisiologia , Atletismo/fisiologia , Adaptação Fisiológica , Adulto , Brasil , Coração/inervação , Humanos , Masculino , Educação Física e Treinamento , Descanso , Adulto Jovem
4.
Braz J Microbiol ; 44(1): 15-21, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24159278

RESUMO

Puba or carimã is a Brazilian staple food obtained by spontaneous submerged fermentation of cassava roots. A total of 116 lactobacilli and three cocci isolates from 20 commercial puba samples were recovered on de Man, Rogosa and Sharpe agar (MRS); they were characterized for their antagonistic activity against foodborne pathogens and identified taxonomically by classical and molecular methods. In all samples, lactic acid bacteria were recovered as the dominant microbiota (7.86 ± 0.41 log10 CFU/g). 16S-23S rRNA ARDRA pattern assigned 116 isolates to the Lactobacillus genus, represented by the species Lactobacillus fermentum (59 isolates), Lactobacillus delbrueckii (18 isolates), Lactobacillus casei (9 isolates), Lactobacillus reuteri (6 isolates), Lactobacillus brevis (3 isolates), Lactobacillus gasseri (2 isolates), Lactobacillus nagelii (1 isolate), and Lactobacillus plantarum group (18 isolates). recA gene-multiplex PCR analysis revealed that L. plantarum group isolates belonged to Lactobacillus plantarum (15 isolates) and Lactobacillus paraplantarum (3 isolates). Genomic diversity was investigated by molecular typing with rep (repetitive sequence)-based PCR using the primer ERIC2 (enterobacterial repetitive intergenic consensus). The Lactobacillus isolates exhibited genetic heterogeneity and species-specific fingerprint patterns. All the isolates showed antagonistic activity against the foodborne pathogenic bacteria tested. This antibacterial effect was attributed to acid production, except in the cases of three isolates that apparently produced bacteriocin-like inhibitory substances. This study provides the first insight into the genetic diversity of Lactobacillus spp. of puba.

5.
Lett Appl Microbiol ; 52(6): 642-50, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21466570

RESUMO

AIM: To study genetic diversity of Chromobacterium haemolyticum isolates recovered from a natural tropical lake. METHODS AND RESULTS: A set of 31 isolates were recovered from a bacterial freshwater community by conventional plating methods and subjected to genetic and phenotypic characterization. The 16S ribosomal RNA (rRNA) gene phylogeny revealed that the isolates were related most closely with C. haemolyticum. In addition to the molecular data, our isolates exhibited strong ß-haemolytic activity, were nonviolacein producers and utilized i-inositol, D-mannitol and D-sorbitol in contrast with the other known chromobacteria. Evaluation of the genetic diversity in the 16S rRNA gene, tRNA intergenic spacers (tDNA) and 16S-23S internal transcribed spacers (ITS) unveiled different levels of genetic heterogeneity in the population, which were also observed with repetitive extragenic palindromic (rep)-PCR genomic fingerprinting using the BOX-AR1 primer. tDNA- and ITS-PCR analyses were partially congruent with the 16S rRNA gene phylogeny. The isolates exhibited high resistance to ß-lactamic antibiotics. CONCLUSION: The population genetic heterogeneity was revealed by 16S rRNA gene sequence, ITS and BOX-PCR analysis. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides for the first time an insight into the genetic diversity of phylogenetically close isolates to C. haemolyticum species.


Assuntos
Chromobacterium/genética , Água Doce/microbiologia , Variação Genética , Brasil , Chromobacterium/classificação , Chromobacterium/isolamento & purificação , Chromobacterium/fisiologia , Primers do DNA/genética , DNA Bacteriano/genética , DNA Espaçador Ribossômico/genética , Filogenia , RNA Ribossômico 16S/genética , RNA de Transferência/genética
6.
Braz J Med Biol Res ; 53(9): e9375, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32696817

RESUMO

In this paper, we complement our previous study on the antiproliferative activity of Calea fruticosa (Asteraceae) by isolating the compounds apigenin-4',7-dimethyl ether (1), budlein A (2), quercetin (3), and cichoriin (4) from the plant's aerial parts. The antiproliferative activity of these compounds was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines. Compound 3 displayed moderate antiproliferative activity in three cell lines (HCT-116, PC-3, and SF-295, with cell growth inhibition values of 72.97, 74.55, and 68.94%) and high antiproliferative activity (90.86%) in the HL-60 cell line. The in vitro sun protection factor (SPF) of the extracts and compound 4, with and without sunscreen, was determined by a spectrophotometric method. The ethanol extract exhibited the highest SPF (9.67) at a concentration of 0.100 mg/mL, while compound 4, isolated from this extract, showed a SPF of 13.79 at the same concentration. A relative increased efficacy of SPF was observed for the extracts and compound 4 when sunscreen was also used. Compound 4 has not been reported previously from any species within the genus Calea. Compounds 1-4 were obtained from this species for the first time.


Assuntos
Asteraceae , Extratos Vegetais , Substâncias Protetoras , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos
7.
Microb Ecol ; 58(4): 762-72, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19504148

RESUMO

The aim of this study was to evaluate the resistance to ten antimicrobial agents and the presence of bla ( TEM1 ) gene of Gram-negative bacteria isolated from three natural oligotrophic lakes with varying degrees of anthropogenic influence. A total of 272 indigenous bacteria were recovered on eosin methylene blue medium; they were characterized for antimicrobial resistance and identified taxonomically by homology search and phylogenetic comparisons. Based on 16S ribosomal RNA sequences analysis, 97% of the isolates were found to be Gram-negative bacteria; they belonged to 11 different genera. Members of the genera Acinetobacter, Enterobacter, and Pseudomonas predominated. Most of the bacteria were resistant to at least one antimicrobial. The incidence of resistance to beta-lactams, chloramphenicol, and mercury was high, whereas resistance to tetracycline, aminoglycosides, and nalidixic acid was low. There was a great frequency of multiple resistances among the isolates from the three lakes, although no significant differences were found among the disturbed and reference lakes. The ampicillin resistance mechanism of 71% of the isolates was due to the gene bla ( TEM1 ). Our study suggests that multiresistant Gram-negative bacteria and the bla ( TEM1 ) gene are common in freshwater oligotrophic lakes, which are subject to different levels of anthropogenic inputs.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Bactérias Gram-Negativas/efeitos dos fármacos , Microbiologia da Água , DNA Bacteriano/genética , Água Doce/análise , Água Doce/microbiologia , Genes Bacterianos , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/isolamento & purificação , Testes de Sensibilidade Microbiana , Filogenia , RNA Ribossômico 16S/genética , beta-Lactamases/genética
8.
Genet Mol Res ; 8(2): 709-17, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19554770

RESUMO

Though the replacement of European bees by Africanized honey bees in tropical America has attracted considerable attention, little is known about the temporal changes in morphological and genetic characteristics in these bee populations. We examined the changes in the morphometric and genetic profiles of an Africanized honey bee population collected near where the original African swarms escaped, after 34 years of Africanization. Workers from colonies sampled in 1968 and in 2002 were morphometrically analyzed using relative warps analysis and an Automatic Bee Identification System (ABIS). All the colonies had their mitochondrial DNA identified. The subspecies that mixed to form the Africanized honey bees were used as a comparison for the morphometric analysis. The two morphometric approaches showed great similarity of Africanized bees with the African subspecies, Apis mellifera scutellata, corroborating with other markers. We also found the population of 1968 to have the pattern of wing venation to be more similar to A. m. scutellata than the current population. The mitochondrial DNA of European origin, which was very common in the 1968 population, was not found in the current population, indicating selective pressure replacing the European with the African genome in this tropical region. Both morphometric methodologies were very effective in discriminating the A. mellifera groups; the non-linear analysis of ABIS was the most successful in identifying the bees, with more than 94% correct classifications.


Assuntos
Abelhas/genética , Animais , Abelhas/anatomia & histologia , Abelhas/classificação , DNA Mitocondrial/genética , Genética Populacional , Tempo
9.
Water Sci Technol ; 60(10): 2729-37, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19923780

RESUMO

An evaluation of the efficiency of bacterial biomass augmentation was performed at lab-scale for the pollution treatment of the Derby-Tacaruna canal. The canal is located at the central area of Great Recife, alongside an important urban corridor. The characterization of the canal water in different tidal conditions showed that the actual pollution is organic and inorganic (heavy metals). Degradation experiments of water from the canal and rain-off system polluted by synthetic wastewater were performed, using activated sludge and an industrial bioadditive. Continuous reactors under two different conditions were evaluated: with diffuse aeration and without aeration. The channel reactor was operated under steady state conditions at a flow rate of 2.5 L h(-1) and with an average residence time of 22 h without aeration and 17 h with aeration. The organic matter removal was in the range of 60% for the system inoculated with the bioadditive and 85% with activated sludge. It was concluded that the water of the Derby-Tacaruna canal may be treated by activated sludge without being affected by its salt content, while the bioaugmentation technique was not satisfactory due to inhibition by inorganics.


Assuntos
Purificação da Água/métodos , Biodegradação Ambiental , Biomassa , Brasil , Esgotos , Clima Tropical , Eliminação de Resíduos Líquidos/métodos , Movimentos da Água , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo , Poluição Química da Água/prevenção & controle
10.
FEMS Microbiol Lett ; 271(2): 230-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17425662

RESUMO

Aspergillus fumigatus possesses a branched mitochondrial electron transport chain, with both cyanide-sensitive and -insensitive oxygen-consumption activities. Mitochondrial reactive oxygen species mediate signaling for alternative oxidase (AOX) expression. A 1173 bp-long Afaox gene encoding a 40 kDa protein has been cloned and identified. Recombinant constructs containing the Afaox ORF were transformed into Escherichia coli and Saccharomyces cerevisiae for heterologous expression. In A. fumigatus, AOX activity and mRNA expression were both induced with menadione or paraquat, suggesting an important role of AOX under oxidative stress. Therefore, positive transformants showed a cyanide-resistant and salicylhydroxamic acid-sensitive respiration, whereas in control cells the oxygen uptake was completely inhibited after KCN addition.


Assuntos
Aspergillus fumigatus/genética , Proteínas Fúngicas/genética , Estresse Oxidativo , Oxirredutases/genética , Sequência de Aminoácidos , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/metabolismo , Western Blotting , Clonagem Molecular , Cianetos/farmacologia , Ativação Enzimática/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Mitocôndrias/enzimologia , Mitocôndrias/metabolismo , Proteínas Mitocondriais , Dados de Sequência Molecular , Oxirredutases/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Paraquat/farmacologia , Proteínas de Plantas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Salicilamidas/farmacologia , Homologia de Sequência de Aminoácidos , Vitamina K 3/farmacologia
11.
Genet Mol Res ; 6(3): 510-21, 2007 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-17985304

RESUMO

A freshwater enterobacterial population (N = 111) was studied for antimicrobial and mercury resistance patterns, and for its possible association with biotic and abiotic factors in that environment. Conventional biochemical tests identified Klebsiella sp, Morganella sp, Serratia sp, Escherichia sp, Enterobacter sp, Edwarsiella sp, Proteus sp, Citrobacter sp, Providencia sp, and Kluyvera sp. There was no correlation between antimicrobial resistance patterns of isolates and bacterial genera, but resistance patterns varied among water samples and between seasons. Resistance to multiple antimicrobials was common (61%). The percentage of bacteria resistant to at least one antimicrobial differed between the rainy (100%) and dry seasons (89%). Resistance to beta-lactams and chloramphenicol was the most frequent and resistance to amikacin, gentamicin and kanamycin was less frequent. The main water variables examined (abiotic factors pH and temperature; biotic factor chlorophyll a concentration) did not influence antimicrobial resistance. Significant impact on freshwater enterobacteria, as evidenced by antimicrobial-multiple resistance and by the presence of bla(TEM) gene, may point to the fact that it has an important role in horizontal spread of resistance.


Assuntos
Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/metabolismo , Microbiologia da Água , Brasil , Cloranfenicol/farmacologia , Clorofila/química , Clorofila A , Concentração de Íons de Hidrogênio , Mercúrio/toxicidade , Modelos Estatísticos , Oxigênio/química , Reação em Cadeia da Polimerase , Temperatura , beta-Lactamases/metabolismo , beta-Lactamas/farmacologia
12.
Neotrop Entomol ; 46(2): 223-230, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27844468

RESUMO

In order to find new alternatives for vector control and personal protection, we evaluated the larvicidal and repellent activity of essentials oils from plants found in the Northeast of Brazil against Aedes aegypti Linnaeus mosquitoes. The plants tested include Xylopia laevigata, Xylopia frutescens, and Lippia pedunculosa and their major compounds, piperitenone oxide, and (R)-limonene. The essential oil of L. pedunculosa and its major volatile compounds were shown to be toxic for Ae. aegypti larvae with a LC50 lower than 60 ppm. The essential oil of plants from the Xylopia genus, on the other hand, showed no activity against Ae. aegypti, proving to be toxic to mosquito larvae only when concentrations were higher than 1000 ppm. All plants tested provided some degree of protection against mosquitoes landing, but only the essential oil of L. pedunculosa and the volatile compound piperitenone oxide suppressed 100% of mosquitoes landing on human skin, in concentrations lower than 1%. Among the plants studied, the essential oil of L. pedunculosa and its volatiles compounds have shown the potential for the development of safe alternative for mosquito larvae control and protection against Ae. aegypti mosquito bites.


Assuntos
Aedes , Inseticidas/toxicidade , Óleos Voláteis/toxicidade , Animais , Brasil , Humanos , Larva , Lippia , Controle de Mosquitos , Xylopia
13.
Biochim Biophys Acta ; 1490(3): 237-44, 2000 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-10684969

RESUMO

We are interested in studying the ubiquitin (UBI) gene expression during different stress and growth conditions in the filamentous fungus Aspergillus nidulans. Here, we report the cloning of a cDNA clone that corresponds to a gene, ubi1, that encodes a carboxyl extension protein from A. nidulans. This cDNA corresponds to a gene that encodes a protein that showed high homology to other polyubiquitin and CEP-80 genes at the N- and C-terminus, respectively. We characterize the mRNA expression of the CEP and polyubiquitin genes during several growth and stress conditions. Expression of the ubi1 and ubi4 genes was correlated with cell growth in most of the carbon sources used, except maltose. Both ubi1 and ubi4 genes were induced upon heat-shock, although the levels of expression were raised quicker for ubi4 than for ubi1. The ubi1 and ubi4 genes displayed a very complex expression pattern in presence of drugs with a different mechanism of action suggesting that the regulatory processes controlling UBI gene expression discriminate between different stresses and can affect individually each UBI gene. The ubi1 gene was highly expressed in presence of hydrogen peroxide while the ubi4 mRNA level was not affected; several metals in our experimental conditions were not able to induce either ubi1 nor ubi4 genes.


Assuntos
Aspergillus nidulans/genética , Precursores de Proteínas/genética , Ubiquitinas/genética , Sequência de Aminoácidos , Aspergillus nidulans/química , Sequência de Bases , Biopolímeros/química , Biopolímeros/genética , Clonagem Molecular , DNA Complementar/química , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Temperatura Alta , Dados de Sequência Molecular , Poliubiquitina , Precursores de Proteínas/química , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Ubiquitinas/química
14.
J Ethnopharmacol ; 96(1-2): 335-9, 2005 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-15588686

RESUMO

In Brazil, pomegranate (Punica granatum L. (Punicaceae)) is widely used as a phytotherapeutic agent. This study evaluates the effect of pomegranate extract on Staphylococcus aureus FRI 722 growth and subsequent enterotoxin production. Bacterial susceptibility was determined by tube dilution method and production of enterotoxin was assessed using membrane-over-agar (MOA) plates. At a low extract concentration (0.01% v/v) bacterial growth was delayed, while a higher concentration (1% v/v) eliminated bacterial growth. Most interestingly, a 0.05% (v/v) concentration of extract was found to inhibit Staphylococcal enterotoxin (SE) A production. These data further implicate pomegranate extracts as potential antibacterial therapeutics with the added ability to inhibit enterotoxin production.


Assuntos
Antibacterianos/farmacologia , Enterotoxinas/antagonistas & inibidores , Lythraceae , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Contagem de Colônia Microbiana , Relação Dose-Resposta a Droga , Enterotoxinas/biossíntese , Frutas/química , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Staphylococcus aureus/crescimento & desenvolvimento , Fatores de Tempo
15.
Hum Exp Toxicol ; 34(11): 1139-47, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25673179

RESUMO

Anabolic androgenic steroids lead to cardiac complications and have been shown to exhibit proapoptotic effects in cardiac cells; however, the mechanism involved in those effects is unclear. The aim of this study was to assess whether apoptosis and the activation of caspase-3 (Casp-3) induced by testosterone in high concentrations involves increments in tumor necrosis factor-α (TNF-α) concentrations and angiotensin-converting enzyme (ACE) activity in cardiomyocytes (H9c2) cell cultures. Cardiomyocytes were treated with testosterone (5 × 10(-6) mol/L), doxorubicin (9.2 × 10(-6) mol/L), testosterone + etanercept (Eta; 6.67 × 10(-5) mol/L), testosterone + losartan (Los; 10(-7) mol/L), and testosterone + AC-DEVD-CHO (10(-5) mol/L; Casp-3 inhibitor). Apoptosis was determined by flow cytometry and by the proteolytic activity of Casp-3. We demonstrated that incubation of H9c2 cells for 48 h with testosterone causes the apoptotic death of 60-70% of the cells and co-treatments with Eta, Los, or AC-DEVD-CHO reduced this effect. Testosterone also induces apoptosis (concentration dependent) and increases the proteolytic activity of Casp-3, which were reduced by co-treatments. TNF-α and ACE activities were elevated by testosterone treatment, while co-treatment with Los and Eta reduced these effects. We concluded that an interaction between testosterone, angiotensin II, and TNF-α induced apoptosis and Casp-3 activity in cultured cardiomyocytes, which contributed to the reduced viability of these cells induced by testosterone in toxic concentrations.


Assuntos
Miócitos Cardíacos/efeitos dos fármacos , Peptidil Dipeptidase A/metabolismo , Testosterona/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Linhagem Celular , Miócitos Cardíacos/metabolismo , Ratos , Sistema Renina-Angiotensina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
16.
Rev. bras. pesqui. méd. biol ; Braz. j. med. biol. res;53(9): e9375, 2020. tab, graf
Artigo em Inglês | LILACS, Coleciona SUS (Brasil) | ID: biblio-1132551

RESUMO

In this paper, we complement our previous study on the antiproliferative activity of Calea fruticosa (Asteraceae) by isolating the compounds apigenin-4',7-dimethyl ether (1), budlein A (2), quercetin (3), and cichoriin (4) from the plant's aerial parts. The antiproliferative activity of these compounds was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method against human tumor cell lines. Compound 3 displayed moderate antiproliferative activity in three cell lines (HCT-116, PC-3, and SF-295, with cell growth inhibition values of 72.97, 74.55, and 68.94%) and high antiproliferative activity (90.86%) in the HL-60 cell line. The in vitro sun protection factor (SPF) of the extracts and compound 4, with and without sunscreen, was determined by a spectrophotometric method. The ethanol extract exhibited the highest SPF (9.67) at a concentration of 0.100 mg/mL, while compound 4, isolated from this extract, showed a SPF of 13.79 at the same concentration. A relative increased efficacy of SPF was observed for the extracts and compound 4 when sunscreen was also used. Compound 4 has not been reported previously from any species within the genus Calea. Compounds 1-4 were obtained from this species for the first time.


Assuntos
Humanos , Extratos Vegetais , Asteraceae , Substâncias Protetoras , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos
17.
Res Microbiol ; 150(6): 407-11, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10466409

RESUMO

A study was carried out to assess the stability of antimicrobial susceptibility of wild isolates upon long-term storage using fifty-three Escherichia coli strains isolated in 1978 from feces of healthy children from the Amazon region in Brazil, exposed to low levels of antimicrobial agents, and examined for resistance to mercury and four antibiotics. All of the strains were kept in Lignières medium at room temperature and were transferred to fresh media four times during this period. Thirty-five out of the 53 strains analyzed in 1978 were viable. Upon recovery, antibiotic and mercury resistance was estimated. All of the 35 strains maintained their original phenotype in a stable fashion, except for one multiresistant strain which became susceptible to kanamycin. Fifty-four percent of the strains exhibited a resistance phenotype, among which 47% had conjugative plasmids.


Assuntos
Resistência Microbiana a Medicamentos/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Indígenas Sul-Americanos , Cloreto de Mercúrio/farmacologia , Brasil , Criança , Cloranfenicol/farmacologia , Fezes/microbiologia , Humanos , Canamicina/farmacologia , Fenótipo , Fatores R/genética , Borracha , Estreptomicina/farmacologia , Tetraciclina/farmacologia , Fatores de Tempo
18.
J Agric Food Chem ; 47(2): 566-75, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10563934

RESUMO

For a correct characterization of Madeira wine commercially available in the market, 52 samples having different types and ages, representative of the delimited region of Madeira (liquor wine of quality produced in delimited region), were analyzed in relation to physicochemical and sensorial parameters. Standard methodology for spirits and alcoholic beverages as well as a council of tasters were adopted respectively to quantify such parameters, according to European Union regulations. The main physicochemical parameters analyzed demonstrated that Madeira wine represent a high quality beverage without toxicological risks, as all constituents have in general contents clearly below the maximum concentration admissible by the national and/or international rules. A reasonable differentiation of properties could be achieved between samples having different types and ages, when principal component, discriminant and cluster analyses were applied to the analytical data, especially for physicochemical parameters.


Assuntos
Vinho/análise , Fenômenos Químicos , Físico-Química , Indicadores e Reagentes , Minerais/análise , Controle de Qualidade , Olfato , Dióxido de Enxofre/análise , Paladar
19.
Lett Appl Microbiol ; 47(4): 241-9, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19241517

RESUMO

AIMS: Forty-nine bacteria isolated from four newly-produced waste samples of a steel industry, which had a high content of CaO, MgO, Cr and P2O5, were characterized molecularly and phenotypically by susceptibility testing against heavy metals. METHODS AND RESULTS: Phylogenetic analysis using 16S rRNA gene sequences revealed that the isolates belonged to nine genera, Pseudomonas, Micrococcus, Acinetobacter, Bacillus, Dietzia, Kocuria, Diaphorobacter, Staphylococcus and Brevibacillus. Besides, some isolates could be affiliated to species: M. luteus, Ac. junii, Ac. schindleri, B. cereus, K. marina, D. nitroreducens and Staph. warneri. The bacteria that were characterized are taxonomically diverse, and Pseudomonas and Micrococcus predominated. Fingerprinting BOX-PCR revealed high genomic heterogeneity among the isolates. Among the heavy metal compounds Zn, Ni, Pb and Cu were least toxic to the bacterial isolates, whereas Ag inhibited all isolates at 0.001 mmol l(-1). CONCLUSIONS: Heterotrophic bacteria, affiliated with several phylogentic groups, were able to colonize different wastes of a steel industry. SIGNIFICANCE AND IMPACT OF THE STUDY: This study extends our knowledge of the early colonizers bacteria populating siderurgic environments. Some of these bacteria could have potential for recycling siderurgic waste for steel production.


Assuntos
Bactérias/classificação , Bactérias/genética , Resíduos Industriais , Aço , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Biodegradação Ambiental , Impressões Digitais de DNA , DNA Bacteriano/análise , DNA Ribossômico/análise , DNA Ribossômico/genética , Poluentes Ambientais/toxicidade , Variação Genética , Genoma Bacteriano , Resíduos Industriais/análise , Metais Pesados/toxicidade , Testes de Sensibilidade Microbiana , Filogenia , RNA Ribossômico 16S/genética
20.
Braz. j. microbiol ; Braz. j. microbiol;44(1): 15-21, 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-676881

RESUMO

Puba or carimã is a Brazilian staple food obtained by spontaneous submerged fermentation of cassava roots. A total of 116 lactobacilli and three cocci isolates from 20 commercial puba samples were recovered on de Man, Rogosa and Sharpe agar (MRS); they were characterized for their antagonistic activity against foodborne pathogens and identified taxonomically by classical and molecular methods. In all samples, lactic acid bacteria were recovered as the dominant microbiota (7.86 ± 0.41 log10 CFU/g). 16S-23S rRNA ARDRA pattern assigned 116 isolates to the Lactobacillus genus, represented by the species Lactobacillus fermentum (59 isolates), Lactobacillus delbrueckii (18 isolates), Lactobacillus casei (9 isolates), Lactobacillus reuteri (6 isolates), Lactobacillus brevis (3 isolates), Lactobacillus gasseri (2 isolates), Lactobacillus nagelii (1 isolate), and Lactobacillus plantarum group (18 isolates). recA gene-multiplex PCR analysis revealed that L. plantarum group isolates belonged to Lactobacillus plantarum (15 isolates) and Lactobacillus paraplantarum (3 isolates). Genomic diversity was investigated by molecular typing with rep (repetitive sequence)-based PCR using the primer ERIC2 (enterobacterial repetitive intergenic consensus). The Lactobacillus isolates exhibited genetic heterogeneity and species-specific fingerprint patterns. All the isolates showed antagonistic activity against the foodborne pathogenic bacteria tested. This antibacterial effect was attributed to acid production, except in the cases of three isolates that apparently produced bacteriocin-like inhibitory substances. This study provides the first insight into the genetic diversity of Lactobacillus spp. of puba.


Assuntos
Humanos , Fermentação , Variação Genética , Técnicas In Vitro , Lactobacillus plantarum/genética , Lactobacillus plantarum/isolamento & purificação , Manihot/genética , Reação em Cadeia da Polimerase/métodos , Amostras de Alimentos , Métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA