Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros











Intervalo de ano de publicação
2.
Parkinsons Dis ; 2017: 9641392, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28280646

RESUMO

Parkinson's disease (PD) is a neurodegenerative condition, which compromises the motor functions and causes the alteration of some executive brain functions. The presence of changes in cognitive symptoms in PD could be due to the procedure of deep brain stimulation (DBS). We searched in several databases for studies that compared performance in executive function tests before and after the DBS procedure in PE and then performed a meta-analysis. After the initial search, there were 15 articles that specifically evaluated the functions of verbal fluency, working memory, cognitive flexibility, abstract thinking, and inhibition. It was found that there were differences in the evaluation of the cognitive functions in terms of the protocols, which generated heterogeneity in the results of the meta-analysis. Likewise, a tendency to diminish functions like verbal fluency and inhibition was found, being this consistent with similar studies. In the other functions evaluated, no difference was found between pre- and postsurgery scores. Monitoring of this type of function is recommended after the procedure.

3.
Plant Biol (Stuttg) ; 15(5): 808-18, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23126265

RESUMO

Phaseolus vulgaris (common bean) is an agronomic important legume crop native to America, where two centres of genetic diversification (GD) are recognised, one in Mesoamerica and the other in the south Andes. Mesoamerican bean accessions have preferential and more efficient nodulation with Rhizobium etli strains carrying the allele nodC type-α, which is predominant in soils of Mesoamerica. It was previously demonstrated that the host nuclear factor NF-YC1, which is involved in nodule formation and rhizobial infection, contributes to this preferential selection and enhances nodulation in the domesticated accession NAG12 from Mesoamerica. Here, we show that both domesticated and wild Mesoamerican beans exhibit higher nodulation performance with a nodC type-α than with a nodC type-δ strain. Transcripts of NF-YC1 significantly increased in roots of these accessions 24 h post-inoculation (hpi) with the nodC type-α strain. On the other hand, accessions from the Andean GD centre formed a higher number of nodules with a strain carrying the nodC type-δ, which is predominant in Andean soils. However, NF-YC1 transcript levels did not exhibit significant changes in Andean accessions upon inoculation with the nodC type-δ strain, at least at 24 hpi. RNA interference (RNAi)-mediated gene silencing of NF-YC1 in the domesticated Andean accession Alubia showed that NF-YC1 or a closely related member of this family is required for nodule formation and bacterial infection, in agreement with observations in Mesoamerican common beans. Isolation and sequencing of the full-length ORF of NF-YC1 from Alubia revealed that it was identical to the sequence previously identified in the Mesoamerican accession NAG12. Interestingly, overexpression of NF-YC1 had a negative impact on nodule formation in the Alubia accession, independently of the R. etli lineage. Our findings suggest that transcriptional and functional variation of NF-YC1 occurs among genetically diverse bean accessions, which might positively or negatively contribute to the fine-tuning mechanisms that regulate nodule formation in the common bean-R. etli symbiosis.


Assuntos
Fator de Ligação a CCAAT/genética , Variação Genética , Micorrizas , Phaseolus/genética , Proteínas de Plantas/genética , Rhizobium/genética , Simbiose/genética , América , Proteínas de Bactérias/genética , Fator de Ligação a CCAAT/metabolismo , DNA de Plantas , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes de Plantas , N-Acetilglucosaminiltransferases/genética , Fases de Leitura Aberta , Phaseolus/metabolismo , Phaseolus/microbiologia , Proteínas de Plantas/metabolismo , Raízes de Plantas , Homologia de Sequência , Microbiologia do Solo , Especificidade da Espécie , Transcrição Gênica
4.
Lett Appl Microbiol ; 39(1): 25-33, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15189284

RESUMO

AIMS: A reliable procedure for the identification of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood disease of honey bees (Apis mellifera L.) based on the polymerase chain reaction (PCR) and subspecies - specific primers is described. METHODS AND RESULTS: By using ERIC-PCR, an amplicon of ca 970 bp was found among P. l. larvae strains but not in other closely related species. Based on the nucleotide sequence data of this amplicon, we designed the pair of oligonucleotides KAT 1 and KAT 2, which were assayed as primers in a PCR reaction. A PCR amplicon of the expected size ca 550 bp was only found in P. l. larvae strains. CONCLUSIONS: This PCR assay provides a specific detection for P. l. larvae. SIGNIFICANCE AND IMPACT OF THE STUDY: The developed PCR assay is highly specific because can differentiate Paenibacillus larvae subsp. larvae from the closely related Paenibacillus larvae subsp. pulvifaciens. The technique can be directly used to detect presence or absence of P. l. larvae spores in honey bee brood samples and contaminated honeys.


Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Abelhas/microbiologia , Reação em Cadeia da Polimerase/métodos , Animais , Bacillaceae/genética , Bacillaceae/crescimento & desenvolvimento , Abelhas/crescimento & desenvolvimento , Primers do DNA , Mel/microbiologia , Larva/microbiologia , Especificidade da Espécie , Esporos Bacterianos/genética
5.
Rev Argent Microbiol ; 34(4): 193-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12600002

RESUMO

A post-harvest bacterial decay was observed on ready-to-use French endives in Argentina. Affected chicons showed browning and soft-rot of inner leaves and marginal necrosis. Physiological and biochemical tests allowed us to identify the isolates from endive as Pseudomonas fluorescens bv. III, Pseudomonas fluorescens bv. V, and Pseudomonas cichorii. Pathogenicity was verified on RTU healthy endives by inoculation with each bacterial species, and also with the mixture of the 3 strains. P. cichorii caused dark brown necrosis of the margins of outer leaves; both isolates of P. fluorescens caused browning and soft-rotting of inner leaves, while the mixture induced all the described symptoms, that were similar to those found in natural infection. Identity of bacterial isolates was confirmed by RFLP analysis of a PCR-DNA fragment amplified from the 16S rRNA gene. This is the first record of a post-harvest decay in endives in Argentina.


Assuntos
Asteraceae/microbiologia , Contaminação de Alimentos , Microbiologia de Alimentos , Doenças das Plantas/microbiologia , Pseudomonas/isolamento & purificação , Argentina , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , DNA Ribossômico/genética , Fluorescência , Folhas de Planta/microbiologia , Polimorfismo de Fragmento de Restrição , Pseudomonas/química , Pseudomonas/genética , Pseudomonas/patogenicidade , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/isolamento & purificação , Pseudomonas fluorescens/patogenicidade , RNA Bacteriano/genética , RNA Ribossômico 16S/genética
6.
Rev. argent. microbiol ; 34(4): 193-8, 2002 Oct-Dec.
Artigo em Inglês | BINACIS | ID: bin-39059

RESUMO

A post-harvest bacterial decay was observed on ready-to-use French endives in Argentina. Affected chicons showed browning and soft-rot of inner leaves and marginal necrosis. Physiological and biochemical tests allowed us to identify the isolates from endive as Pseudomonas fluorescens bv. III, Pseudomonas fluorescens bv. V, and Pseudomonas cichorii. Pathogenicity was verified on RTU healthy endives by inoculation with each bacterial species, and also with the mixture of the 3 strains. P. cichorii caused dark brown necrosis of the margins of outer leaves; both isolates of P. fluorescens caused browning and soft-rotting of inner leaves, while the mixture induced all the described symptoms, that were similar to those found in natural infection. Identity of bacterial isolates was confirmed by RFLP analysis of a PCR-DNA fragment amplified from the 16S rRNA gene. This is the first record of a post-harvest decay in endives in Argentina.

7.
Rev. argent. microbiol ; 34(4): 193-8, 2002 Oct-Dec.
Artigo em Espanhol | LILACS-Express | LILACS, BINACIS | ID: biblio-1171713

RESUMO

A post-harvest bacterial decay was observed on ready-to-use French endives in Argentina. Affected chicons showed browning and soft-rot of inner leaves and marginal necrosis. Physiological and biochemical tests allowed us to identify the isolates from endive as Pseudomonas fluorescens bv. III, Pseudomonas fluorescens bv. V, and Pseudomonas cichorii. Pathogenicity was verified on RTU healthy endives by inoculation with each bacterial species, and also with the mixture of the 3 strains. P. cichorii caused dark brown necrosis of the margins of outer leaves; both isolates of P. fluorescens caused browning and soft-rotting of inner leaves, while the mixture induced all the described symptoms, that were similar to those found in natural infection. Identity of bacterial isolates was confirmed by RFLP analysis of a PCR-DNA fragment amplified from the 16S rRNA gene. This is the first record of a post-harvest decay in endives in Argentina.

8.
J Biotechnol ; 91(2-3): 181-8, 2001 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-11566389

RESUMO

The common bean (Phaseolus vulgaris L.) is cultivated widely in Central and South America and particularly in the Northwest of Argentina. In order to describe the diversity of the common bean nodulating rhizobial population from the bean producing area in Northwest Argentina (NWA), a collection of about 400 isolates of common beans recovered from nodules and soil samples from NWA were characterized by using nifH-PCR, analysis of genes coding for 16S rRNA and nodC, and REP-fingerprinting, respectively. It was found that species Rhizobium etli is predominant in common bean nodules although a high degree of diversity was found within the species. Other bean nodulating genotypes recovered from soils by using Leucaena sp. as the trapping host was found to have the 16S rDNA alleles of species such as Sinorhizobium fredii, Sinorhizobium saheli, Sinorhizobium teranga, Mesorhizobium loti, and Rhizobium tropici. Some of the bean genotypes that were found to be more efficient in green house experiments were selected and assayed in two successive bean-cropping seasons in the field environment in NWA, and an increase in yields with inoculation was found. The performance of strains isolated from the region indicates potential for exploiting the diversity.


Assuntos
Variação Genética , Phaseolus/microbiologia , Rhizobiaceae/fisiologia , Argentina , Proteínas de Bactérias , N-Acetilglucosaminiltransferases/genética , Oxirredutases/genética , Filogenia , RNA Ribossômico 16S
9.
Can J Microbiol ; 47(6): 509-18, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11467726

RESUMO

A defined insertion mutant of a gene encoding a homolog of the rhizobial C4-dicarboxylate permease (dctA) was constructed in Rhizobium tropici strain CIAT899. This mutant (GA1) was unable to grow on fumarate or malate; however, in contrast with other rhizobial dctA mutants, it retained a limited ability to grow on succinate with ammonia as a nitrogen source. Our results suggest the presence of a novel succinate-specific transport system in R. tropici. Biochemical characterization indicated that this alternative transport system in GAI is active and dependent on an energized membrane. It was also induced by succinate and aspartate, and was repressed by glucose and glycerol. Bean plants inoculated with GA1 showed a reduced nitrogen-fixing ability, achieving only 29% of the acetylene reduction activity determined in CIAT899 strain nodules, 33 days after inoculation. Also, bean plants inoculated with GA1 had reduced shoot dry weight compared with plants inoculated with the wild-type strain.


Assuntos
Proteínas de Bactérias/genética , Transportadores de Ácidos Dicarboxílicos/genética , Ácidos Dicarboxílicos/metabolismo , Mutação , Rhizobium/crescimento & desenvolvimento , Ácido Succínico/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sequência de Bases , Transporte Biológico , Transportadores de Ácidos Dicarboxílicos/metabolismo , Fabaceae/microbiologia , Dados de Sequência Molecular , Rhizobium/genética , Análise de Sequência de DNA , Simbiose
10.
Mol Plant Microbe Interact ; 14(1): 55-62, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11194871

RESUMO

A mutation in the ilvC gene of Sinorhizobium meliloti 1021 determines a symbiotically defective phenotype. ilvC mutants obtained from different S. meliloti wild-type strains are able to induce root hair deformation on alfalfa roots and show variable activation of the common nodulation genes nodABC. All of these mutants are noninfective. The presence of extra copies of nodD3-syrM in an IlvC- background does not promote nod expression but allows the detection of low levels of Nod factor production. The sulphation of the Nod factor metabolites, however, is not affected. Furthermore, IlvC- strains induce a specific pattern of starch accumulation on alfalfa roots as well as of early nodulin expression. Hence, the pleiotropic action of the ilvC gene in S. meliloti may reveal novel complexities involved in the symbiotic interaction.


Assuntos
Medicago sativa/microbiologia , Sinorhizobium meliloti/genética , Oxirredutases do Álcool/genética , Genes Bacterianos , Cetol-Ácido Redutoisomerase , Medicago sativa/citologia , Medicago sativa/metabolismo , Proteínas dos Microtúbulos/genética , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , Sinorhizobium meliloti/enzimologia , Simbiose
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA