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1.
Mol Oral Microbiol ; 31(1): 43-58, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26205976

RESUMO

Morphogenesis protein C (MorC) of Aggregatibacter actinomycetemcomitans is important for maintaining the membrane morphology and integrity of the cell envelope of this oral pathogen. The MorC sequence and operon organization were found to be conserved in Gammaproteobacteria, based on a bioinformatic analysis of 435 sequences from representative organisms. Functional conservation of MorC was investigated using an A. actinomycetemcomitans morC mutant as a model system to express MorC homologs from four phylogenetically diverse representatives of the Gammaproteobacteria: Haemophilus influenzae, Escherichia coli, Pseudomonas aeruginosa, and Moraxella catarrhalis. The A. actinomycetemcomitans strains expressing the homologous proteins were assessed for sensitivity to bile salts, leukotoxin secretion, autoaggregation and membrane morphology. MorC from the most closely related organism (H. influenzae) was functionally identical to MorC from A. actinomycetemcomitans. However, the genes from more distantly related organisms restored some but not all A. actinomycetemcomitans mutant phenotypes. In addition, deletion mutagenesis indicated that the most conserved portion of the protein, the C-terminus DUF490 domain, was necessary to maintain the integrity of the membrane. Deletion of the last 10 amino acids of this domain of the A. actinomycetemcomitans MorC protein was sufficient to disrupt membrane stability and leukotoxin secretion. The data suggest that the MorC sequence is functionally conserved across Gammaproteobacteria and the C-terminus of the protein is essential for maintaining membrane physiology.


Assuntos
Aggregatibacter actinomycetemcomitans/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/fisiologia , Proteínas de Membrana/fisiologia , Aggregatibacter actinomycetemcomitans/genética , Aggregatibacter actinomycetemcomitans/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sequência de Bases , Ácidos e Sais Biliares/metabolismo , Membrana Celular/metabolismo , Membrana Celular/fisiologia , DNA Bacteriano/genética , Exotoxinas/análise , Exotoxinas/metabolismo , Genes Bacterianos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Microscopia Eletrônica de Transmissão , Domínios Proteicos , Deleção de Sequência
2.
Mol Oral Microbiol ; 30(2): 97-110, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25055881

RESUMO

The cell envelope of gram-negative bacteria serves a critical role in maintenance of cellular homeostasis, resistance to external stress, and host-pathogen interactions. Envelope protein composition is influenced by the physiological and environmental demands placed on the bacterium. In this study, we report a comprehensive compilation of cell envelope proteins from the periodontal and systemic pathogen Aggregatibacter actinomycetemcomitans VT1169, an afimbriated serotype b strain. The urea-extracted membrane proteins were identified by mass spectrometry-based shotgun proteomics. The membrane proteome, isolated from actively growing bacteria under normal laboratory conditions, included 648 proteins representing 27% of the predicted open reading frames in the genome. Bioinformatic analyses were used to annotate and predict the cellular location and function of the proteins. Surface adhesins, porins, lipoproteins, numerous influx and efflux pumps, multiple sugar, amino acid and iron transporters, and components of the type I, II and V secretion systems were identified. Periplasmic space and cytoplasmic proteins with chaperone function were also identified. A total of 107 proteins with unknown function were associated with the cell envelope. Orthologs of a subset of these uncharacterized proteins are present in other bacterial genomes, whereas others are found exclusively in A. actinomycetemcomitans. This knowledge will contribute to elucidating the role of cell envelope proteins in bacterial growth and survival in the oral cavity.


Assuntos
Aggregatibacter actinomycetemcomitans/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Membrana Celular/metabolismo , Parede Celular/metabolismo , Periplasma/metabolismo , Proteoma/metabolismo , Aggregatibacter actinomycetemcomitans/genética , Proteínas da Membrana Bacteriana Externa/genética , Sistemas de Secreção Bacterianos , Biologia Computacional , Genoma Bacteriano
3.
NeuroRehabilitation ; 7(2): 95-117, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-24525849

RESUMO

Traumatic brain injury (TBI) has a devastating effect on all aspects of a person's life, which negatively impacts the individual's quality of life. Indeed, the individual is not the same person following TBI. However, through systematic life care planning and appropriate long-term care, this negative impact can be mitigated.

4.
Acta Neurochir Suppl ; 79: 43-4, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11974985

RESUMO

Over 250 survivors of brain injury were clinically evaluated and a long term care plan developed for each of them. 105 survivors were located and a follow-up questionnaire was administered at least two years later to the survivors and families to evaluate the predictions that were made regarding long-term needs. The study looked at the impact on eight survival roles as defined by WHO and attempted to determine the effectiveness of services, correlating various treatment modalities and services with changes, adjustments, accommodations, achievements, and future goals. Results showed that there is a correlation between some non-traditional therapies (Recreational and Cognitive) and for individuals' future goals in physical independence, mobility, community reintergration and self care. These future goals were not significant for occupational and physical therapies. Also, a less significant correlation was made between paid attendant care and level of outside activities.


Assuntos
Lesões Encefálicas/psicologia , Lesões Encefálicas/reabilitação , Papel (figurativo) , Sobreviventes/psicologia , Lesões Encefálicas/fisiopatologia , Emprego , Objetivos , Humanos , Inquéritos e Questionários , Índices de Gravidade do Trauma
5.
Brain Inj ; 18(1): 103-9, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14660239

RESUMO

PRIMARY OBJECTIVES: To assess the outcome of severe traumatic brain injury at least 1 year after trauma, in relation to some early clinical prognostic factors occurring during coma recovery. RESEARCH DESIGN: Retrospective study conducted at the post-coma unit of a rehabilitation hospital. METHODS AND PROCEDURES: A total of 43 patients were included. All of the patients sustained severe traumatic brain injury and prolonged coma, i.e. coma lasting at least 15 days. Outcome was assessed by means of Glasgow Coma Scale, Barthel Index and Mini Mental State 1 year after trauma, in relation to some early clinical prognostic factors occurring during coma recovery. MAIN OUTCOMES AND RESULTS: At the 1 year follow-up, a statistically significant correlation was found with both the Glasgow Outcome Scale and the Barthel Index for the time interval from brain injury to recovery of the following clinical variables: optical fixation, ability to obey commands, spontaneous motor activity and first safe oral feeding. Psychomotor agitation and bulimia were also favourable prognostic factors for the final outcome. CONCLUSIONS: In the present study, first safe oral feeding during coma recovery represents the clinical feature that better predicts the final outcome of patients with severe traumatic brain injury and prolonged coma.


Assuntos
Lesões Encefálicas/reabilitação , Ingestão de Alimentos , Adolescente , Adulto , Criança , Feminino , Seguimentos , Escala de Resultado de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Recuperação de Função Fisiológica , Estudos Retrospectivos , Fatores de Tempo
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