Respiratory failure

O conceito de insuficiência respiratória (IR) compreende a dificuldade encontrada pelo Sistema Respiratório em desempenhar adequadamente sua principal função, ou seja, a promoção das trocas gasosas. Por ser decorrente de várias condições, pode apresentar-se, clinicamente, de forma muito variada. Seu diagnóstico depende da análise dos níveis de oxigênio e gás carbônico através da gasometria arterial. O presente artigo fornece uma visão geral da fisiologia das trocas gasosas e suas alterações, conceitos fundamentais para a compreensão da classificação e mecanismos envolvidos nos diferentes tipos de insuficiência respiratória. São ainda enfatizados aspectos gerais, relacionados com a terapêutica, na forma de noções sobre oxigenioterapia e indicações de suporte ventilatório.The Respiratory Failure concept deals with the presence of difficulties for the respiratory system to perform its most important function, to keep satisfactory gas exchanges. There are several causes of respiratory failure, with different clinical features. The diagnosis of respiratory failure depends on the analyses of oxygen and carbon dioxide levels in arterial blood samples. This article contains a general view about gas exchange physiology and its disorders, that are the basis for understanding the classification and mechanisms involved with the different types of Respiratory Failure. It is also emphasized general aspects dealing with therapeutic issues, such as oxygen-therapy and ventilatory support indications

Complete genome sequence of the sugarcane nitrogen-fixing endophyte gluconacetobacter diazotrophicus PAL5

17 p. : il.Background: Gluconacetobacter diazotrophicus Pal5 is an endophytic diazotrophic bacterium that lives in association with sugarcane plants. It has important biotechnological features such as nitrogen fixation, plant growth promotion, sugar metabolism pathways, secretion of organic acids, synthesis of auxin and the occurrence of bacteriocins. Results: Gluconacetobacter diazotrophicus Pal5 is the third diazotrophic endophytic bacterium to be completely sequenced. Its genome is composed of a 3.9 Mb chromosome and 2 plasmids of 16.6 and 38.8 kb, respectively. We annotated 3,938 coding sequences which reveal several characteristics related to the endophytic lifestyle such as nitrogen fixation, plant growth promotion, sugar metabolism, transport systems, synthesis of auxin and the occurrence of bacteriocins. Genomic analysis identified a core component of 894 genes shared with phylogenetically related bacteria. Gene clusters for gum-like polysaccharide biosynthesis, tad pilus, quorum sensing, for modulation of plant growth by indole acetic acid and mechanisms involved in tolerance to acidic conditions were identified and may be related to the sugarcane endophytic and plant-growth promoting traits of G. diazotrophicus. An accessory component of at least 851 genes distributed in genome islands was identified, and was most likely acquired by horizontal gene transfer. This portion of the genome has likely contributed to adaptation to the plant habitat. Conclusion: The genome data offer an important resource of information that can be used to manipulate plant/bacterium interactions with the aim of improving sugarcane crop production and other biotechnological applications