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1.
J Infect Public Health ; 13(5): 724-729, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32224108

RESUMO

BACKGROUND: The co-circulation of Chikungunya (CHIKV), Dengue (DENV) and Zika (ZIKV) viruses increased the risk of outbreaks and coinfections among them. Here, we report cases of coinfection in clinical samples from state of Tocantins, Brazil. METHODS: In 2017, the Central Public Health Laboratory (LACEN) received samples of patients who consulted health units with symptoms compatible with arboviral infections. A total of 102 samples were sent to the Retrovirology Laboratory at the Federal University of São Paulo, where they were tested by RT-qPCR to confirm DENV, ZIKV and CHIKV infections and to detect coinfected patients. RESULTS: We identified with CHIKV monoinfection (52), DENV serotypes 1 (28) and serotypes 2 (22). We did not detect ZIKV. Five patients were characterized with coinfection involving CHIKV and DENV serotype 2. CONCLUSIONS: The presence of co-circulating arboviruses increases the chance of coinfection and demonstrates the importance of differential diagnosis and vector control.


Assuntos
Febre de Chikungunya/epidemiologia , Coinfecção/epidemiologia , Dengue/epidemiologia , Infecção por Zika virus/epidemiologia , Adolescente , Adulto , Brasil/epidemiologia , Febre de Chikungunya/sangue , Febre de Chikungunya/diagnóstico , Febre de Chikungunya/genética , Vírus Chikungunya/isolamento & purificação , Criança , Coinfecção/diagnóstico , Estudos Transversais , Dengue/sangue , Dengue/diagnóstico , Dengue/genética , Vírus da Dengue/isolamento & purificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sorogrupo , Adulto Jovem , Zika virus/isolamento & purificação , Infecção por Zika virus/sangue
2.
J Appl Microbiol ; 127(4): 1018-1027, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31278820

RESUMO

AIM: To evaluate the activity and effectiveness of impregnated central venous catheters (CVC) against Klebsiella pneumoniae biofilms. METHODS AND RESULTS: The antimicrobial activity and durability of impregnated-CVCs were evaluated over time and the size of zones of inhibition (ZI) was measured. Biofilm formation was observed by quantitative culture and also by scanning electron microscopy. The catheters impregnated with chlorhexidine/silver sulfadiazine (CHX/SS) reduced bacteria counts by 0·3 log and were most effective (P < 0·01) against Klebsiella pneumoniae biofilms N-acetylcysteine/levofloxacin (NAC/LEV) catheters. It was observed that the catheter impregnated with NAC/LEV had initially the largest average ZI size being statistically significant (P < 0·01). The NAC/LEV combination remained active until day 30, whereas the combination of CHX/SS was completely inactivated from day 15 on. CONCLUSIONS: The NAC/LEV combination showed greater durability on the catheters, but it was the CHX/SS combination that had the greater initial efficacy in bacterial inhibition. It was also observed that NAC/LEV-impregnated catheters do not prevent the emergence of resistant subpopulations inside the inhibition halos during antimicrobial susceptibility tests. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results highlighted that the in vitro efficacy of antimicrobial-impregnated CVCs is limited by time and that their colonization occurred earlier than expected. Our data also demonstrated that NAC/LEV remained active until day 30 of evaluation and CHX/SS combination was completely inactivated from day 15 on. Our findings suggested that implantable devices should be carefully used by medical community.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Catéteres/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Acetilcisteína/farmacologia , Biofilmes/crescimento & desenvolvimento , Clorexidina/farmacologia , Farmacorresistência Bacteriana , Klebsiella pneumoniae/fisiologia , Levofloxacino/farmacologia , Sulfadiazina de Prata/farmacologia , Fatores de Tempo
3.
Cytopathology ; 29(4): 355-360, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29893438

RESUMO

INTRODUCTION: To evaluate the internal quality control indicators and quality management programme in a university cytopathology laboratory. METHODS: All results of conventional cervical smears tests (taken from the SISCAN, the Brazilian cervical cancer screening system) of women aged ≥15 years at the time of Papanicolaou smear specimen collection during January 2007-December 2014 were included. The final results of the cytopathology were classified in accordance with the Bethesda System. The variables included in the database were the woman's name, date of birth, and age at the time of sampling (15-30, 31-40 and older than 40 years). RESULTS: In this period, 50 286 cytopathology examinations were carried out. Of these, 44 386 (91.34%) were negative for malignancy or unsatisfactory and 4209 (8.66%) presented epithelial abnormalities. The percentage of the tests consistent with atypical squamous cells (ASC) between satisfactory examinations was 4.12%; the percentage of tests compatible with ASC among abnormal examinations was 47.87%; the ASC/squamous intraepithelial lesion) ratio was 0.97 and the percentage of high-grade squamous intraepithelial lesion among satisfactory tests was 2.21%, and the 5-year retrospective review identified 4.97% of false-negative results. CONCLUSION: All rates obtained were consistent over the years and within the recommended values by Federal Regulation of Brazil. This demonstrates the efficacy of our established internal quality monitoring and continuing education, reflecting the commitment of the team involved in the release of smear reports.


Assuntos
Colo do Útero/patologia , Teste de Papanicolaou/normas , Controle de Qualidade , Doenças do Colo do Útero/patologia , Adolescente , Adulto , Brasil , Serviços de Laboratório Clínico , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Universidades
4.
Biomed Res Int ; 2018: 4785089, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30627560

RESUMO

The neural dysfunction is triggered by cellular and molecular events that provoke neurotoxicity and neural death. Currently, neurodegenerative diseases are increasingly common, and available treatments are focused on relieving symptoms. Based on the above, in this review we describe the participation of vitexin in the main events involved in the neurotoxicity and cell death process, as well as the use of vitexin as a therapeutic approach to suppress or attenuate neurodegenerative progress. Vitexin contributes to increasing neuroprotective factors and pathways and counteract the targets that induce neurodegeneration, such as redox imbalance, neuroinflammation, abnormal protein aggregation, and reduction of cognitive and/or motor impairment. The results obtained provide substantial evidence to support the scientific exploration of vitexin in these pathologies, since their effects are still little explored for this direction.


Assuntos
Apigenina/uso terapêutico , Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Agregação Patológica de Proteínas/tratamento farmacológico , Animais , Morte Celular/efeitos dos fármacos , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Agregação Patológica de Proteínas/metabolismo , Agregação Patológica de Proteínas/patologia
5.
J Dent Res ; 97(1): 33-40, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29053389

RESUMO

A valuable approach to understand how individual and population genetic differences can predispose to disease is to assess the impact of genetic variants on cellular functions (e.g., gene expression) of cell and tissue types related to pathological states. To understand the genetic basis of nonsyndromic cleft lip with or without cleft palate (NSCL/P) susceptibility, a complex and highly prevalent congenital malformation, we searched for genetic variants with a regulatory role in a disease-related tissue, the lip muscle (orbicularis oris muscle [OOM]), of affected individuals. From 46 OOM samples, which are frequently discarded during routine corrective surgeries on patients with orofacial clefts, we derived mesenchymal stem cells and correlated the individual genetic variants with gene expression from these cultured cells. Through this strategy, we detected significant cis-eQTLs (i.e., DNA variants affecting gene expression) and selected a few candidates to conduct an association study in a large Brazilian cohort (624 patients and 668 controls). This resulted in the discovery of a novel susceptibility locus for NSCL/P, rs1063588, the best eQTL for the MRPL53 gene, where evidence for association was mostly driven by the Native American ancestry component of our Brazilian sample. MRPL53 (2p13.1) encodes a 39S protein subunit of mitochondrial ribosomes and interacts with MYC, a transcription factor required for normal facial morphogenesis. Our study illustrates not only the importance of sampling admixed populations but also the relevance of measuring the functional effects of genetic variants over gene expression to dissect the complexity of disease phenotypes.


Assuntos
Fenda Labial/genética , Fissura Palatina/genética , Proteínas Ribossômicas/genética , Adolescente , Criança , Pré-Escolar , Feminino , Genes/genética , Estudo de Associação Genômica Ampla , Humanos , Lactente , Recém-Nascido , Masculino , Ribossomos Mitocondriais/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Adulto Jovem
6.
Lett Appl Microbiol ; 65(4): 306-312, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28712134

RESUMO

Infectious wastes are potential sources of pathogenic micro-organisms, which may represent a risk to the professionals who manage them. In this study, we aimed to characterize the infectious bacteria present in dental waste and waste workers. The dental waste produced over 24 h was collected and waste workers were sampled by swabbing. Isolate resistance profiles were characterized by Vitek® and PCR and biofilm formation by Congo Red agar, string test and microtitre assay. To assess similarity between the waste and the workers' samples, a random amplified polymorphic DNA test was used. Twenty-eight bacteria were identified as clinically relevant. The most frequent gene was blaTEM present in five Gram-negative micro-organisms, and one blaSHV in Klebsiella pneumoniae. All Pseudomonas aeruginosa were positive to extracellular polymeric substances formation, except one isolated from a worker. Klebsiella pneumoniae had negative results for the string test. Pseudomonas aeruginosa showed better adherence at 25°C after 48 h of incubation and K. pneumonia had the best biofilm formation at the same temperature, after 24 h. The similarity between P. aeruginosa recovered from dental waste and from workers was low, however, it is important to note that a pathogen was found on a worker's hands and that improvements in biosafety are required. SIGNIFICANCE AND IMPACT OF THE STUDY: Infectious dental waste can contain clinically relevant bacteria with important resistance and biofilm profiles. These micro-organisms could be transmitted to waste workers, other professionals and patients if the principles of biosafety measures are neglected. To our knowledge, no study has ever evaluated the microbial characterization and the potential contamination risk of dental infectious waste and waste handlers. The presence of clinically relevant bacteria in the hands and nasal mucosa of waste workers highlights the need for studies in this field to clarify the risk of these pathogens in dental healthcare services, and to stress the need for an efficient waste management.


Assuntos
Resíduos Odontológicos/análise , Mãos/microbiologia , Klebsiella pneumoniae/isolamento & purificação , Mucosa/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Instrumentos Odontológicos/microbiologia , Humanos , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/genética , Gerenciamento de Resíduos , beta-Lactamases/genética
7.
Oral Dis ; 22(3): 241-5, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26714022

RESUMO

OBJECTIVES: We investigated the association between non-syndromic oral cleft and variants in IRF6 (rs2235371 and rs642961) and 8q24 region (rs987525) according to the ancestry contribution of the Brazilian population. SUBJECTS AND METHODS: Subjects with oral cleft (CL, CLP, or CP) and their parents were selected from different geographic regions of Brazil. Polymorphisms were genotyped using a TaqMan assay and genomic ancestry was estimated using a panel of 48 INDEL polymorphisms. RESULTS: A total of 259 probands were analyzed. A TDT detected overtransmission of the rs2235371 G allele (P = 0.0008) in the total sample. A significant association of this allele was also observed in CLP (P = 0.0343) and CLP + CL (P = 0.0027). IRF6 haplotype analysis showed that the G/A haplotype increased the risk for cleft in children (single dose: P = 0.0038, double dose: P = 0.0022) and in mothers (single dose: P = 0.0016). The rs987525 (8q24) also exhibited an association between the A allele and the CLP + CL group (P = 0.0462). These results were confirmed in the probands with European ancestry. CONCLUSIONS: The 8q24 region plays a role in CL/P and the IRF6 G/A haplotype (rs2235371/rs642961) increases the risk for oral cleft in the Brazilian population.


Assuntos
Cromossomos Humanos Par 8 , Fenda Labial/genética , Fissura Palatina/genética , Fatores Reguladores de Interferon/genética , Alelos , População Negra/genética , Brasil , Haplótipos , Humanos , Mutação INDEL , Indígenas Sul-Americanos/genética , Linhagem , Polimorfismo Genético , População Branca/genética
8.
Genet Mol Res ; 12(2): 1974-81, 2013 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-23913380

RESUMO

Huntington's disease (HD) is a rare progressive and fatal neurogenetic degenerative disease, characterized by movement and personality disorders and by progressive dementia. Its prevalence varies by ethnic origin and different genetic profiles predisposing individuals to HD in each population. The prevalence of HD is 5-10 per 100,000 individuals in Caucasian populations of North America and Western Europe. It is an autosomal dominant disease associated with the expansion of CAG-type repetitive DNA sequences in the HTT gene. This gene, located on the short arm of chromosome 4, encodes the protein huntingtin. In this study, we reviewed 17 articles about HD that report data from 2400 affected individuals from various countries around the world, including Venezuela, China, Croatia, Turkey, Germany, Italy, Brazil, Spain, Taiwan, India, the Netherlands, Russia, and the USA, with a focus on genetic profiles and intergenerational expansions or contractions of expanded alleles responsible for causing HD. We discuss the genetic characteristics of HD in different populations and any atypical cases reported in these studies.


Assuntos
Doença de Huntington/epidemiologia , Doença de Huntington/genética , Proteínas do Tecido Nervoso/genética , Alelos , América/epidemiologia , Povo Asiático/genética , Povo Asiático/estatística & dados numéricos , Cromossomos Humanos Par 4 , Europa (Continente)/epidemiologia , Humanos , Proteína Huntingtina , Doença de Huntington/etnologia , Proteínas do Tecido Nervoso/metabolismo , Expansão das Repetições de Trinucleotídeos , Turquia/epidemiologia , População Branca/genética , População Branca/estatística & dados numéricos
9.
Anat Histol Embryol ; 42(3): 213-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22971214

RESUMO

The morphology of the ovaries and oogenesis of Pimelodella vittata were studied using anatomical and histological techniques to provide information of its reproductive biology. Eighty adult females were captured trimonthly during the period November 2005 to October 2006. The ovaries are paired, saculiform organs, which are coated with tunica albuginea and contain ovigerous lamellae, where the oocytes develop before being released into the ovarian lumen and following the ovarian duct until reaching the genital papilla. Oogenesis was divided into stages based on the alterations to the nucleus, ooplasm and surrounding follicular layers. Oogonia form groups from the germinal epithelium have asynchronous development and differentiate into initial perinucleolar oocytes. The formation of the zona pellucida is initiated in the advanced perinucleolar oocytes reaching a thickness of 1.46±0.58 µm in the vitellogenic oocytes. The follicular cells are squamous in perinucleolar oocytes, become cubical in the pre-vitellogenic oocytes and prismatic in the vitellogenic oocytes with a height of 11.20±4.74 µm. The histochemical reactions indicate that zona pellucida, cortical alveoli and yolk globules contain neutral glycoproteins and the follicular cells contain neutral glycoproteins in association with carboxylated and sulphated glycoconjugates. Statistical analyses showed significant differences in the diameter of the oocytes and follicular cells height as oocytes matured. This study represents the first data about the ovarian structure and oogenesis of this species.


Assuntos
Peixes-Gato/anatomia & histologia , Peixes-Gato/fisiologia , Oogênese/fisiologia , Ovário/anatomia & histologia , Ovário/fisiologia , Animais , Feminino
10.
Arq. Inst. Biol ; 79(1)jan.-mar. 2012.
Artigo em Português | LILACS-Express | VETINDEX | ID: biblio-1462138

RESUMO

The sorghum crop has grown rapidly in recent years, for being a plant with xerophilous characteristics; its production has especially increased in Northeastern Brazil due to its ability to withstand dry environments. Weeds are a major problem for grain crops, as these can significantly reduce yield, particularly when they emerge in the early stages of crops. To obtain crops resistant to weeds, studies have been conducted to demonstrate that some plants have a natural defense consisting in an organism's ability to produce metabolites that act to either inhibit or stimulate growth and development of other organisms grown in the same environment, which is called allelopathy. Sorghum is one of the plants that possess proven allelopathy, producing a set of lipid complex substances and proteins generically called sorgoleone, having as its main compound 2-hydroxy-5-methoxy-3-[(Z,Z)-8',11',14'-pentadecatriene]-p-benzoquinone, which is naturally released into the soil from their roots and trichomes, inhibiting the growth of weeds upon contact with them. Because of these inherent characteristics of the sorghum crop, the present work aims to discuss the possible benefits of using this cereal, due to its allelopathic effects, as well as to inform about the known mechanisms of production and action of the main constituent compounds of sorgoleone and other compounds produced by the plant's roots.


A cultura do sorgo cresceu rapidamente nestes últimos anos, por ser uma planta com características xerófilas, apresentando um aumento de sua produção principalmente na região nordeste devido a sua capacidade de suportar ambientes de cultivo mais secos. As ervas daninhas são um grande problema para os cultivares, pois estas podem reduzir significativamente a produção de grãos, particularmente quando surgem nas fases iniciais das culturas. Visando a obtenção de culturas resistentes às ervas daninhas, estudos têm sido realizados demonstrando que algumas plantas possuem uma defesa natural que consiste na capacidade de um organismo produzir metabólitos que atuam inibindo ou o crescimento ou o desenvolvimento de outros organismos que estão próximos; a esta capacidade dá-se o nome de alelopatia. O sorgo é uma das plantas que possuem sua alelopatia comprovada, produzindo um complexo de substâncias lipídicas e proteínas denominados genericamente de sorgoleone, tendo como seu principal composto o 2-hidroxi-5-metoxi-3-[(Z,Z)-8',11',14'-pentadecatrieno]-p-benzoquinona, que é naturalmente liberado para o solo a partir dos tricomas das suas raízes e, no momento em que entram em contato com as ervas daninhas, inibem seu crescimento. Devido a tais características inerentes à cultura do sorgo, este trabalho tem como objetivo discorrer sobre os possíveis benefícios do uso desse cereal devido a sua comprovada alelopatia, bem como informar os conhecidos mecanismos de produção e atuação dos principais compostos constituintes do sorgoleone produzidos pelas suas raízes.

11.
Arq. Inst. Biol. ; 79(1)2012.
Artigo em Português | VETINDEX | ID: vti-698609

RESUMO

The sorghum crop has grown rapidly in recent years, for being a plant with xerophilous characteristics; its production has especially increased in Northeastern Brazil due to its ability to withstand dry environments. Weeds are a major problem for grain crops, as these can significantly reduce yield, particularly when they emerge in the early stages of crops. To obtain crops resistant to weeds, studies have been conducted to demonstrate that some plants have a natural defense consisting in an organism's ability to produce metabolites that act to either inhibit or stimulate growth and development of other organisms grown in the same environment, which is called allelopathy. Sorghum is one of the plants that possess proven allelopathy, producing a set of lipid complex substances and proteins generically called sorgoleone, having as its main compound 2-hydroxy-5-methoxy-3-[(Z,Z)-8',11',14'-pentadecatriene]-p-benzoquinone, which is naturally released into the soil from their roots and trichomes, inhibiting the growth of weeds upon contact with them. Because of these inherent characteristics of the sorghum crop, the present work aims to discuss the possible benefits of using this cereal, due to its allelopathic effects, as well as to inform about the known mechanisms of production and action of the main constituent compounds of sorgoleone and other compounds produced by the plant's roots.


A cultura do sorgo cresceu rapidamente nestes últimos anos, por ser uma planta com características xerófilas, apresentando um aumento de sua produção principalmente na região nordeste devido a sua capacidade de suportar ambientes de cultivo mais secos. As ervas daninhas são um grande problema para os cultivares, pois estas podem reduzir significativamente a produção de grãos, particularmente quando surgem nas fases iniciais das culturas. Visando a obtenção de culturas resistentes às ervas daninhas, estudos têm sido realizados demonstrando que algumas plantas possuem uma defesa natural que consiste na capacidade de um organismo produzir metabólitos que atuam inibindo ou o crescimento ou o desenvolvimento de outros organismos que estão próximos; a esta capacidade dá-se o nome de alelopatia. O sorgo é uma das plantas que possuem sua alelopatia comprovada, produzindo um complexo de substâncias lipídicas e proteínas denominados genericamente de sorgoleone, tendo como seu principal composto o 2-hidroxi-5-metoxi-3-[(Z,Z)-8',11',14'-pentadecatrieno]-p-benzoquinona, que é naturalmente liberado para o solo a partir dos tricomas das suas raízes e, no momento em que entram em contato com as ervas daninhas, inibem seu crescimento. Devido a tais características inerentes à cultura do sorgo, este trabalho tem como objetivo discorrer sobre os possíveis benefícios do uso desse cereal devido a sua comprovada alelopatia, bem como informar os conhecidos mecanismos de produção e atuação dos principais compostos constituintes do sorgoleone produzidos pelas suas raízes.

12.
Lett Appl Microbiol ; 51(4): 370-6, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20723041

RESUMO

AIMS: This study was undertaken to detect, identify and determine antifungal susceptibility of yeast strains isolated from dental solid waste and to evaluate airborne fungi in the Brazilian dental health care environment and in the waste storage room. METHODS AND RESULTS: A group of 17 yeast strains were identified by macroscopic and microscopic characteristics, API 20C Aux system and Multiplex PCR. All 104 airborne fungal colonies were identified by macroscopic and microscopic morphology. The CLSI broth microdilution method was utilized as the susceptibility test. Candida parapsilosis was the prevailing yeast species recovered from waste, followed by Rhodotorula glutinis. Three strains of Candida guilliermondii presented minimal inhibitory concentration values considered to be susceptible dose dependent (2 µg ml(-1)) to voriconazole. Of all airborne fungal species, 69% were recovered from the waste storage room and 31% were recovered from the clinical/surgical environment. Most of them were identified as Cladosporium spp. CONCLUSIONS: These findings reinforce the potential risk of waste handling and point out the need for safe management to minimize the spread of these agents to the environment. Filamentous fungi isolation in almost all sampled environments indicates that a periodic monitoring of airborne microbiota in the dental health care service environment is required. SIGNIFICANCE AND IMPACT OF THE STUDY: The survival of yeast strains for 48 h suggests that dental waste should be carefully controlled and monitored.


Assuntos
Microbiologia do Ar , Serviços de Saúde Bucal , Resíduos Odontológicos/análise , Fungos/isolamento & purificação , Antifúngicos/farmacologia , Brasil , Candida/classificação , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Fungos/classificação , Fungos/efeitos dos fármacos , Fungos/genética , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase/métodos , Rhodotorula/classificação , Rhodotorula/efeitos dos fármacos , Rhodotorula/isolamento & purificação , Especificidade da Espécie
13.
Nanotechnology ; 20(39): 395701, 2009 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-19724106

RESUMO

C(60)-derived nanobaskets, with chemical formulae (symmetry point group) C(40)H(10) (C(5v)), C(39)H(12) (C(3v)), C(46)H(12) (C(2v)), were investigated. Molecular dynamic simulations (MDSs) indicate that the molecules preserve their bonding frame for temperatures up to 300 K (simulation time 100 ps), and maintain atomic cohesion for at least 4 ps at temperatures up to 3500 K. The infrared spectra of the C(60)-derived nanobaskets were simulated through density functional theory (DFT) calculations, allowing for the attribution of infrared signatures specific to each carbon nanobasket. The possibility of using C(60)-derived nanobaskets as molecular containers is demonstrated by performing a DFT study of their bonding to hydrogen, water, and L-alanine. The carbon nanostructures presented here show a higher bonding energy (approximately 1.0 eV), suggesting that a family of nanostructures, C(n)-derived (n = 60,70,76,80, etc) nanobaskets, could work as molecular containers, paving the way for future developments such as tunable traps for complex molecular systems.

14.
Genet Mol Res ; 8(2): 751-7, 2009 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-19681026

RESUMO

The pollination effectiveness of the stingless bee Melipona quadrifasciata and the honey bee Apis mellifera was tested in tomato plots. The experiment was conducted in four greenhouses as well as in an external open plot in Ribeirão Preto, SP, Brazil. The tomato plants were exposed to visits by M. quadrifasciata in one greenhouse and to A. mellifera in another; two greenhouses were maintained without bees (controls) and an open field plot was exposed to pollinators in an area where both honey bee and stingless bee colonies are abundant. We counted the number of tomatoes produced in each plot. Two hundred tomatoes from each plot were weighed, their vertical and transversal circumferences were measured, and the seeds were counted. We collected 253 Chrysomelidae, 17 Halictidae, one Paratrigona sp, and one honey bee from the flowers of the tomato plants in the open area. The largest number of fruits (1414 tomatoes), the heaviest and largest tomatoes, and the ones with the most seed were collected from the greenhouse with stingless bees. Fruits cultivated in the greenhouse with honey bees had the same weight and size as those produced in one of the control greenhouses. The stingless bee, M. quadrifasciata, was significantly more efficient than honey bees in pollinating greenhouse tomatoes.


Assuntos
Abelhas/fisiologia , Polinização , Solanum lycopersicum/fisiologia , Animais , Comportamento Animal , Produtos Agrícolas/anatomia & histologia , Solanum lycopersicum/anatomia & histologia , Sementes
15.
Langmuir ; 25(8): 4751-9, 2009 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-19239222

RESUMO

We present some computational simulations of graphene-based nanoribbons with a number of half-twists varying from 0 to 4 and two types of defects obtained by removing a single carbon atom from two different sites. Optimized geometries are found by using a mix of classical quantum semiempirical computations. According with the simulations results, the local curvature of the nanoribbons increases at the defect sites, especially for a higher number of half-twists. The HOMO-LUMO energy gap of the nanostructures has significant variation when the number of half-twists increases for the defective nanoribbons. At the quantum semiempirical level, the first optically active transitions and oscillator strengths are calculated using the full configuration interaction (CI) framework, and the optical absorption in the UV/vis range (electronic transitions) and in the infrared (vibrational transitions) are achieved. Distinct nanoribbons show unique spectral signatures in the UV/vis range, with the first absorption peaks in wavelengths ranging from the orange to the violet. Strong absorption is observed in the ultraviolet region, although differences in their infrared spectra are hardly discernible.

16.
J Chem Phys ; 128(16): 164719, 2008 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-18447491

RESUMO

Results of classical force field geometry optimizations for twisted graphene nanoribbons with a number of twists N(t) varying from 0 to 7 (the case N(t)=1 corresponds to a half-twist Möbius nanoribbon) are presented in this work. Their structural stability was investigated using the Brenner reactive force field. The best classical molecular geometries were used as input for semiempirical calculations, from which the electronic properties (energy levels, HOMO, LUMO orbitals) were computed for each structure. CI wavefunctions were also calculated in the complete active space framework taking into account eigenstates from HOMO-4 to LUMO+4, as well as the oscillator strengths corresponding to the first optical transitions in the UV-VIS range. The lowest energy molecules were found less symmetric than initial configurations, and the HOMO-LUMO energy gaps are larger than the value found for the nanographene used to build them due to electronic localization effects created by the twisting. A high number of twists leads to a sharp increase of the HOMO-->LUMO transition energy. We suggest that some twisted nanoribbons could form crystals stabilized by dipolar interactions.

17.
J Appl Microbiol ; 103(4): 882-91, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17897190

RESUMO

AIM: This study focuses on investigating the molecular and physiological characteristics of Prevotella intermedia after molecular oxygen exposure (MOE) and the effect on drug susceptibility patterns. METHODS AND RESULTS: Samples of P. intermedia were used as parent strains: ATCC25611 and four clinical isolates. Strains adapted to oxidative stress by MOS were obtained by the enrichment technique. Drug susceptibility was evaluated by minimal inhibitory concentrations (MIC) using agar dilution. Arbitrarily primed-polymerase chain reaction (AP-PCR) was used to evaluate the genetic diversity of all strains and physiological analyses were made by sodiumdodecylsulfate-polyacrylamide gel electrophoresis and two-dimensional electrophoresis of crude, cell-free extracts. The genetic profile showed that lineages with altered MIC values were selected after MOE. Overall, we found significant decrease in drug susceptibility for the aero-strains against all tested antimicrobials (amoxicillin, amoxicillin+clavulanic acid, clindamycin, chloramphenicol, ertapenen and metronidazole). We also observed markedly different protein expression patterns between the parent and selected aero-strains. CONCLUSIONS: MOE induces changes in the genetic profile and protein expression patterns of P. intermedia that may also be linked to its drug resistance mechanisms. SIGNIFICANCE AND IMPACT OF THE STUDY: The effects of MOE on anaerobic bacterial physiology and behaviour may influence antimicrobial susceptibility patterns with potential consequences to antimicrobial chemotherapy.


Assuntos
Antibacterianos/farmacologia , Oxigênio/farmacologia , Prevotella intermedia/efeitos dos fármacos , Adaptação Fisiológica , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana , Eletroforese em Gel Bidimensional/métodos , Regulação Bacteriana da Expressão Gênica , Variação Genética , Humanos , Testes de Sensibilidade Microbiana , Estresse Oxidativo , Reação em Cadeia da Polimerase/métodos , Prevotella intermedia/genética , Prevotella intermedia/fisiologia
18.
J Appl Microbiol ; 103(1): 20-6, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17584449

RESUMO

AIM: The purpose of this study was to investigate the effect of oxidative stress on physiological and genetic characteristics of Fusobacterium nucleatum and its interference on this microbial identification methods. METHODS AND RESULTS: Fus. nucleatum ssp. nucleatum ATCC 25586 (wt-strain) and an oxidative-stress-adapted strain derived from the wt-strain (aero-strain) were employed in the study. Cell-free crude protein extracts were obtained from both strains and differentially expressed proteins were identified by two-dimensional electrophoresis. Bacterium identification was performed by conventional biochemical tests, automated Rapid ID 32A system and specific PCR analysis. Genetic diversity between wt- and aero-strain was assessed by arbitrarily-primed (AP)-PCR. There were significant changes in the protein profile of aero-strain. The identification of the wt-strain was confirmed by all methods employed. Similar results were obtained for aero-strain when conventional biochemical tests and PCR were used. However, aero-strain was identified as Fusobacterium varium when submitted to Rapid ID 32A system. According to AP-PCR analysis, no significant genetic alteration was detected in aero-strain. CONCLUSIONS: The adaptive response of Fus. nucleatum to oxidative stress is associated with changes on its biology, which may lead to misidentification of the organism, according to the conventional identification methods. SIGNIFICANCE AND IMPACT OF THE STUDY: Oxidative stress may act as a cause of adaptive response in Fus. nucleatum with consequences to its biology, such as alterations on biochemical and physiological profile.


Assuntos
Fusobacterium nucleatum/fisiologia , Estresse Oxidativo/fisiologia , Adaptação Fisiológica , Proteínas de Bactérias/metabolismo , Técnicas de Tipagem Bacteriana/métodos , Eletroforese em Gel Bidimensional/métodos , Fusobacterium nucleatum/classificação , Fusobacterium nucleatum/genética , Variação Genética , Reação em Cadeia da Polimerase/métodos
19.
Infect Genet Evol ; 7(4): 469-75, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17336167

RESUMO

The maculata group currently comprises two species of Triatominae, Triatoma maculata and Triatoma pseudomaculata, which share morphologic and chromatic characteristics. In order to clarify the systematic status of these two vectors of Trypanosoma cruzi and to infer their evolutionary relationships, we performed an enzymatic, morphometric and cytogenetic comparison of them, also taking into account two sister species not included in the group (T. arthurneivai and T. wygodzinskyi). According to our results, T. maculata and T. pseudomaculata belong to distinct evolutionary lineages. Similarly, T. arthurneivai topotypes from Minas Gerais form an independent isolated group by morphometrics. Our results also support the specific status of the Triatoma population from São Paulo State (formerly referred to T. arthurneivai), and suggest the possibility that it is T. wygodzinskyi. Finally, we suggest that only the arboricolous T. pseudomaculata from northeast Brazil and the rupicolous sister species originated from São Paulo State should be classified together in the same group.


Assuntos
Evolução Molecular , Triatoma/classificação , Triatoma/genética , Animais , Biometria , Bandeamento Cromossômico , Eletroforese , Isoenzimas , Fenótipo , Especificidade da Espécie , Triatoma/anatomia & histologia , Triatoma/enzimologia
20.
Clin Microbiol Infect ; 12(8): 815-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16842583

RESUMO

This study examined the ability of PCR to amplify Leishmania DNA, stored on Giemsa-stained slides, from American cutaneous leishmaniasis (ACL) patients. In total, 475 slides stored for up to 36 years were obtained from an outpatient clinic in a Brazilian ACL-endemic region, and Leishmania DNA was amplified from 395 (83.2%) of the DNA samples using primers specific for the minicircle kinetoplast DNA. Restriction fragment length polymorphism analysis of these amplicons demonstrated that Leishmania (Viannia) braziliensis was the only species present in these samples. The results demonstrated that archived Giemsa-stained slides can provide a Leishmania DNA source for performing clinical and epidemiological studies of leishmaniasis.


Assuntos
Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Reação em Cadeia da Polimerase/métodos , Animais , Corantes Azur , DNA de Protozoário/análise , Humanos , Polimorfismo de Fragmento de Restrição , Manejo de Espécimes , Fatores de Tempo
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