Répteis em fragmentos de Cerrado e Mata Atlântica no Campo das Vertentes, Estado de Minas Gerais, Sudeste do Brasil

Os dados sobre a fauna reptiliana em Minas Gerais são pontuais e revelam carência de informações sobre esse grupo, principalmente em regiões de transição entre a Mata Atlântica e o Cerrado. A área do estudo está situada no município de Ritápolis (21° 01' 37.07" S e 44° 19' 11.84" O), microrregião Campo das Vertentes, Estado de Minas Gerais, Sudeste do Brasil. Pretendeu-se com a presente pesquisa conhecer a composição da fauna de répteis local. As observações, capturas e coletas foram realizadas quinzenalmente, durante dois dias consecutivos, de agosto de 2005 a julho de 2006. As capturas foram realizadas por meio de armadilhas de interceptação e queda, distribuídas em oito sítios, sendo quatro em área de mata de galeria e quatro em área aberta, perfazendo um esforço amostral de 6.912 horas-balde. Foi também realizada procura ativa e encontros ocasionais com registros fotográficos dos espécimes, e, no caso de serpentes, alguns exemplares foram entregues por terceiros quando encontradas mortos. Registrou-se a presença de 31 espécies de répteis, sendo duas espécies de cágados, nove de lagartos, duas de anfisbenas e 18 de serpentes. Apenas os lagartos Cercosaura ocellata, Enyalius bilineatus e Tupinambis merianae e as serpentes Leptodeira annulata e Apostolepis assimilis foram capturados nas armadilhas de queda. Os lagartos mais comuns foram Ameiva ameiva e Mabuya frenata, e as serpentes mais abundantes foram Oxyrhophus guibei e Sibynomorphus mikanii. Os lagartos estão bem representados na área, com espécies típicas de mata, como Enyalius bilineatus, e de áreas aberta de cerrado, como Ameiva ameiva e Mabuya frenata. A fauna de serpentes possui representantes típicos de áreas abertas do Cerrado, como O. guibei e Micrurus frontalis, e de regiões florestadas, como Liophis poecilogyrus e Philodryas olfersii. A diversidade de espécies de répteis e o registro prévio de Amphisbaena dubia e Hydromedusa tectifera para o Estado de Minas Gerais indicam a grande potencialidade do Campo das Vertentes em revelar a ocorrência de espécies novas ou a ampliação na distribuição de outras

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

A double-layer tracheal tube cuff designed to prevent leakage : a bench-top study

OBJECTIVE: We designed a new endotracheal tube (ETT) cuff that does not form the folds that cause leakage of colonized subglottic secretions upon inflation within the trachea: a standard high-volume low-pressure cuff was draped with a second, highly elastic cuff made of a low-protein guayule natural latex rubber with 0.5 ml gel between the cuffs. We compared this prototype ETT cuff with four commercially available ETTs for efficacy in the prevention of fluid leakage across the cuff. DESIGN: In vitro study. MEASUREMENTS AND RESULTS: We compared fluid leakage in our prototype cuff with that in four commercially available ETTs. Three cylindrical glass tubes 16, 20, and 22 mm in diameter were used as model tracheas, and five different intracuff pressures (20, 25, 30, 40, and 50 cmH(2)O) were tested. Each test was repeated three times with new ETTs. The guayule latex ETT cuff showed an average fluid leakage of 0.0007 +/- 0.002 ml/min which was significantly lower than that in any of the other ETTs (Microcuff 0.07 +/- 0.09, Mallinckrodt/Hi-Lo Evac 5 +/- 5, Euromedical 7 +/- 4, Sheridan/CF 41 +/- 69). CONCLUSIONS: Our prototype ETT cuff significantly reduced fluid leakage in this bench-top study. In vivo testing and evaluation is to follow

Following tracheal intubation, mucus flow is reversed in the semirecumbent position : possible role in the pathogenesis of ventilator-associated pneumonia

OBJECTIVES: Critically ill intubated patients are positioned in the semirecumbent position to prevent pneumonia. In tracheally intubated sheep, we investigated the effects of gravitational force on tracheal mucus transport and on bacterial colonization of the respiratory system. DESIGN: Prospective randomized animal study. SETTING: Animal research facility at the National Institutes of Health. SUBJECTS: Sixteen healthy sheep. INTERVENTIONS: Spontaneously breathing or mechanically ventilated sheep were randomized to be positioned with the orientation of the trachea above (40 degrees, trachea-up) or below (5 degrees, trachea-down) horizontal. MEASUREMENTS AND MAIN RESULTS: Tracheal mucus velocity was measured through radiographic tracking of radiopaque tantalum disks, insufflated into the trachea. After 24 hrs, sheep were euthanized, and samples from the airways and lungs were taken for microbiological analysis. The proximal trachea was colonized in all sheep. In trachea-down sheep, all mucus moved toward the glottis at a mean velocity of 2.1 +/- 1.1 mm/min. When mucus reached the endotracheal tube, it either entered the endotracheal tube or was lodged at the inflated endotracheal tube cuff. In all trachea-up sheep, abnormal tracheal mucus clearance was found. Mucus, mostly on the nondependent part of the trachea, moved toward the glottis at an average velocity of 2.2 +/- 2.0 mm/min and constantly accumulated at the inflated endotracheal tube cuff. From the proximal trachea, mucus eventually moved toward the lungs on the dependent part of the trachea, leading to an "intratracheal route" of colonization of the lungs. Pneumonia was found in 6/8 of trachea-up sheep and the same microorganisms were isolated from the lungs and the proximal trachea. No pneumonia was found in trachea-down sheep (p = .007). CONCLUSIONS: The study indicates that following tracheal intubation gravitational force influences tracheal mucus clearance. When the trachea is oriented above horizontal, a flow of mucus from the proximal trachea toward the lungs is highly associated with bacterial colonization of the airways and pneumonia