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The main purpose of the present study was to compare the accuracy of total daily steps thresholds associated to the recommended 60 min per day moderate-to-vigorous physical activity in adolescents. A total of 156 adolescents, 87 males and 69 females, participated in the present study. Objectively-measured moderate-to-vigorous physical activity and steps were assessed by GT3X accelerometers for eight consecutive days. The accuracy of the following total daily steps thresholds was calculated (males/females): 9,930, 11,714, 12,000, 11,000/10,500, 14,000/11,500, 13,000/ 12,000, 8,500/7,500, 11,500/9,000, 10,500/9,500, 12,118, 12,118/12,605, and 10,000. The results of accuracy both uncensored and censored total daily steps cut-off points ranged from low to high. For the uncensored total daily steps, the cut-off 11,000 for males and 10,500 for females showed the best results: Sensitivity = .85; Specificity = .94; Youden’s index = .78; Proportion of agreement = .93, and Kappa coefficient = .67, p < .001. For the censored total daily steps, the 10,000 cut-off score showed the best results: Sensitivity = .77; Specificity = .95; Youden’s index = .72; Proportion of agreement = .93, and Kappa coefficient = .65, p < .001. Among adolescents for accelerometry-measured total daily steps the 11,000 for males and 10,500 for females cut-off points should be used. For population guidelines regarding health-enhancing steps in adolescents, the cut-off point of 10,000 daily steps seems to be the most appropriate., El propósito principal del presente estudio fue comparar la precisión de los umbrales de pasos diarios totales asociados a la recomendación de 60 minutos por día de actividad física moderada-vigorosa en adolescentes. Un total de 156 adolescentes, 87 varones y 69 mujeres, participaron en el presente estudio. La actividad física moderada-vigorosa y pasos se evaluaron objetivamente con acelerómetros GT3X durante ocho días consecutivos. Se calculó la precisión de los siguientes umbrales de pasos diarios totales (varones/mujeres): 9.930, 11.714, 12.000, 11.000/10.500, 14.000/11.500, 13.000/12.000, 8.500/7.500, 11.500/9.000, 10.500/9.500, 12.118, 12.118/12.605 y 10.000. Los resultados de precisión para los puntos de corte de los pasos diarios ajustados y no ajustados variaron de bajo a alto. Para los pasos diarios no ajustados, los puntos de corte 11.000 para los varones y 10.500 para las mujeres mostraron los mejores resultados: Sensibilidad= 0,85; Especificidad= 0,94; Índice de Youden= 0,78; Proporción de acuerdo= 0,93, y coeficiente de Kappa= 0,67, p < 0,001. Para los pasos diarios ajustados, el puntaje de corte de 10.000 mostró los mejores resultados: Sensibilidad= 0,77; Especificidad= 0,95; Índice de Youden= 0,72; Proporción de acuerdo= 0,93, y coeficiente de Kappa= 0,65, p < 0,001. Entre los adolescentes para los pasos diarios totales medidos con acelerometría se deberían utilizar los puntos de corte 11.000 para los varones y 10.500 para las mujeres. Para las recomendaciones a nivel poblacional sobre los pasos relacionados con la salud en los adolescentes, el punto de corte de 10.000 pasos diarios parece ser el más apropiado.

Burkholderia cenocepacia is a member of the B. cepacia complex (Bcc), a group of opportunistic bacteria that infect the airways of patients with cystic fibrosis (CF) and are extraordinarily resistant to almost all clinically useful antibiotics. Infections in CF patients with Bcc bacteria generally lead to a more rapid decline in lung function, and in some cases to the 'cepacia syndrome', a virtually deadly exacerbation of the lung infection with systemic manifestations. These characteristics of Bcc bacteria contribute to higher morbidity and mortality in infected CF patients. In the last 10 years considerable progress has been made in understanding the interactions between Bcc bacteria and mammalian host cells. Bcc isolates can survive either intracellularly within eukaryotic cells or extracellularly in host tissues. They survive within phagocytes and respiratory epithelial cells, and they have the ability to breach the respiratory epithelium layer. Survival and persistence of Bcc bacteria within host cells and tissues are believed to play a key role in pulmonary infection and to contribute to the persistent inflammation observed in patients with CF. This review summarizes recent findings concerning the interaction between Bcc bacteria and epithelial and phagocytic cells.

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The prosthesis nowadays used in the vascular access for haemodialysis have low patency rates, mainly due to the luminal obstruction, determined by the intimal hyperplasia. Several factors have been related to de development of intimal hyperplasia and graft failure. Among them are the differences in the biomechanical properties between the prosthesis and the native vessels. In the searching for vascular prosthesis that overcomes the limitations of the currently used, the cryopreserved vessels (cryografts) appear as an alternative of growing interest. However, it is unknown if the mechanical differences or mismatch between prosthesis and native vessels are lesser when using cryografts.To characterize and compare the biomechanical behaviour of native vessels used in vascular access and cryografts. Additionally, segments of expanded polytetrafluoroethylene (ePTFE) were also evaluated, so as to evaluate the potential biomechanical advantages of the cryografts respect to synthetic prosthesis used in vascular access.Segments from human humeral (n = 12), carotid (n = 12) and femoral (n = 12) arteries, and saphenous vein (n = 12), were obtained from 6 multiorgan donors. The humeral arteries were studied in fresh state. The other segments were divided into two groups, and 6 segments from each vessel were studied in fresh state, while the remaining 6 segments were evaluated after 30 days of criopreservation. For the mechanical evaluation the vascular segments and 6 segments of ePTFE were mounted in a circulation mock and submitted to haemodynamic conditions similar to those of the in vivo. Instantaneous pressure (Konigsberg) and diameter (Sonomicrometry) were measured and used to calculate the viscous and elastic indexes, the compliance, distensibility and characteristic impedance. For each mechanical parameter studied, the mismatch between the prosthesis and the native vessel was evaluated.The ePTFE was the prosthesis with the higher mechanical mismatch (p0.05). The venous and arterial cryografts showed the least mismatch with native veins and arteries, respectively. The prosthesis with the least mechanical mismatch was different, depending on the native vessel evaluated, and for a native vessel, on the parameter considered.The mechanical mismatch between the native vessel and the vascular prosthesis used in a vascular access could be reduced using cryografts.

Burkholderia cenocepacia is an opportunistic pathogen that displays a remarkably high resistance to antimicrobial peptides. We hypothesize that high resistance to antimicrobial peptides in these bacteria is because of the barrier properties of the outer membrane. Here we report the identification of genes for the biosynthesis of the core oligosaccharide (OS) moiety of the B. cenocepacia lipopolysaccharide. We constructed a panel of isogenic mutants with truncated core OS that facilitated functional gene assignments and the elucidation of the core OS structure in the prototypic strain K56-2. The core OS structure consists of three heptoses in the inner core region, 3-deoxy-d-manno-octulosonic acid, d-glycero-d-talo-octulosonic acid, and 4-amino-4-deoxy-l-arabinose linked to d-glycero-d-talo-octulosonic acid. Also, glucose is linked to heptose I, whereas heptose II carries a second glucose and a terminal heptose, which is the site of attachment of the O antigen. We established that the level of core truncation in the mutants was proportional to their increased in vitro sensitivity to polymyxin B (PmB). Binding assays using fluorescent 5-dimethylaminonaphthalene-1-sulfonyl-labeled PmB demonstrated a correlation between sensitivity and increased binding of PmB to intact cells. Also, the mutant producing a heptoseless core OS did not survive in macrophages as compared with the parental K56-2 strain. Together, our results demonstrate that a complete core OS is required for full PmB resistance in B. cenocepacia and that resistance is due, at least in part, to the ability of B. cenocepacia to prevent binding of the peptide to the bacterial cell envelope