Characterization of a Clp Protease Gene Regulator and the Reaeration Response in Mycobacterium tuberculosis

Mycobacterium tuberculosis (MTB) enters a non-replicating state when exposed to low oxygen tension, a condition the bacillus encounters in granulomas during infection. Determining how mycobacteria enter and maintain this state is a major focus of research. However, from a public health standpoint the importance of latent TB is its ability to reactivate. The mechanism by which mycobacteria return to a replicating state upon re-exposure to favorable conditions is not understood. In this study, we utilized reaeration from a defined hypoxia model to characterize the adaptive response of MTB following a return to favorable growth conditions. Global transcriptional analysis identified the ∼100 gene Reaeration Response, induced relative to both log-phase and hypoxic MTB. This response includes chaperones and proteases, as well as the transcription factor Rv2745c, which we characterize as a Clp protease gene regulator (ClgR) orthologue. During reaeration, genes repressed during hypoxia are also upregulated in a wave of transcription that includes genes crucial to transcription, translation and oxidative phosphorylation and culminates in bacterial replication. In sum, this study defines a new transcriptional response of MTB with potential relevance to disease, and implicates ClgR as a regulator involved in resumption of replication following hypoxia

Speech resonance in orthognathic surgery in subjects with cleft lip and palate Ressonância da fala na cirurgia ortognática em indivíduos com fissura labiopalatina

The main purpose of this study was to investigate the impact of maxillary advancement on speech resonance in subjects with cleft lip and palate. The study sample was composed of 42 subjects aged 16 to 41 years old with operated cleft palate ± lip submitted to maxillary advancement. Resonance was evaluated before and 3 to 12 months after surgery by perceptual analysis and graduated from absent to severe. It was observed that 47.5% of the subjects presented impairment of resonance after orthognathic surgery, with a confidence interval (at 95%) from 31.5% to 63.9%. These results suggest that orthognathic surgery in individuals with cleft palate may interfere in resonance, causing, or increasing the degree of hypernasality. Therefore, this highlights the importance of the orientation about the risks and benefits of maxillary advancement surgery and follow-up of these patients.<br>O propósito deste estudo foi verificar o impacto do avanço de maxila na ressonância de fala em sujeitos com fissura labiopalatina. A amostra do presente estudo foi composta por 42 sujeitos, entre 16 e 41 anos de idade, com fissura de palato associada ou não à de lábio submetidos ao avanço da maxila. A ressonância foi avaliada entre 3 e 12 meses após a cirurgia por análise e perceptual e graduada de ausente a severa. Observou-se que 47.5% dos sujeitos apresentaram prejuízo da ressonância após a cirurgia ortognática, com um intervalo de confiança (a 95%) de 31.5% a 63.9%. Esses resultados sugerem que a cirurgia ortognática, em sujeitos com fissura palatina, pode interferir na ressonância, causando ou aumentando o grau de hipernasalidade. Portanto, isso elucida a importância da orientação sobre os riscos e benefícios da cirurgia de avanço da maxila e acompanhamento desses pacientes