8 research outputs found
Comparaison de performances aérobies et anaérobies au cours d'exercices locaux et généraux
International audiencePurpose: The relationships between the aerobic and anaerobic abilities for local and general exercises has been studied in twenty three subjects.Methods: Maximal aerobic power (PMA), the lactate level corresponding to 4 mmol lâ1 (Pla4) and maximal anaerobic power on a Monark cycle ergometer (general exercises) have been correlated with aerobic and anaerobic performances for knee extension exercises (local exercises). Maximal anaerobic power (Pmax) has been determined by means of a forceâvelocity test on the same Monark ergometer. Two indices of local aerobic ability were estimated: 1) the peak power (Ppic) measured at the end of an incremental knee extension exercise, 2) the knee extension critical power (PC) calculated as equal to the slope of the relationship between exhaustion time and total work performed during three exhaustives exercises at constant load. Maximal anaerobic power of the knee extensors was determined by measuring the maximal power at an angular velocitie of 240° sâ1 (Pbiodex) with an isokinetic ergometer.Results: The correlations between all the indices of local and general aerobic abilities were highly significant (0.82<r<0.96; p<0.001) whatever the expression of the data (absolute values or related to the quadriceps muscle mass). The relationship between PC and Pla4 was significant even when these variables were expressed as fractions of the maximal aerobic power (PC/Ppic and Pla4%: r=0.75; p<0.001). Similarly, Pmax and Pbiodex were correlated even when related to quadriceps muscle mass (r=0.60; p<0.01). In contrast to Pmax, Pbiodex was negatively correlated with the local and general aerobic indices, but only when these variables was related to quadriceps muscle mass (0.44<r<0.63; p<0.05).Conclusions: The general aerobic abilities are very well correlated with the local aerobic abilities. Moreover, the correlation between PC/Ppic and Pla4% suggests that local and the general endurances are partially linked. The best indices of maximal anaerobic power and local anaerobic power are observed in the same subjects. In contrast, the best local and general aerobic indices are observed in the subjects presenting the weakest indices of anaerobic power.Objectif: Afin de prĂ©ciser les relations entre les aptitudes physiques locales et gĂ©nĂ©rales, nous avons procĂ©dĂ© chez 23 sujets Ă l'Ă©tude des corrĂ©lations entre des indices gĂ©nĂ©raux aĂ©robies, des indices locaux aĂ©robies et les puissances maximales anaĂ©robies gĂ©nĂ©rale et locale.MĂ©thodes: Les indices gĂ©nĂ©raux aĂ©robies, reprĂ©sentĂ©s par la puissance maximale aĂ©robie (PMA) et la puissance correspondant Ă une lactatĂ©mie de 4 mmol lâ1 (Pla4), ont Ă©tĂ© dĂ©terminĂ©s Ă l'occasion d'un exercice progressif sur bicyclette ergomĂ©trique. Les indices locaux aĂ©robies ont Ă©tĂ© dĂ©terminĂ©s au moyen d'exercices rĂ©alisĂ©s sur un ergomĂštre conçu pour effectuer des extensions de jambe. Il s'agit de la puissance maximale mesurĂ©e au terme d'un exercice progressif (Ppic) et de la puissance critique (PC), calculĂ©es Ă partir de la relation qui unit le temps et le travail, Ă©tablie Ă l'issue de trois exercices Ă charge constante menĂ©s Ă Ă©puisement. Les puissances maximales anaĂ©robies gĂ©nĂ©rale et locale ont Ă©tĂ© Ă©valuĂ©es, respectivement, au moyen d'un test de charge-vitesse sur ergocycle (Pmax) et d'un test sur ergomĂštre isocinĂ©tique (Pbiodex).RĂ©sultats: Les corrĂ©lations entre toutes les variables aĂ©robies sont hautement significatives (0,82<r<0,96 ; p<0,001), qu'elles soient exprimĂ©es en valeurs absolues ou rapportĂ©es Ă la masse du quadriceps. Les fractions PC/Ppic et Pla4/PMA (Pla4 %) sont Ă©galement corrĂ©lĂ©es (r=0,75 ; p<0,001) et restent significativement corrĂ©lĂ©es aux autres variables aĂ©robies (0,58<r<0,89 ; p<0,01). Pmax et Pbiodex sont corrĂ©lĂ©es, y compris lorsque les valeurs sont rapportĂ©es Ă la masse du quadriceps (r=0,60 ; p<0,01). Ă la diffĂ©rence de Pmax, Pbiodex est nĂ©gativement et significativement corrĂ©lĂ©e aux indices aĂ©robies (Ppic, PC, PC/Ppic, PMA et Pla4 %), mais seulement lorsque les valeurs sont exprimĂ©es en fonction de la masse du quadriceps (0,44<r<0,63 ; p<0,05).Conclusions: Une cohĂ©rence est observĂ©e entre les indices aĂ©robies gĂ©nĂ©raux et locaux. La corrĂ©lation entre PC/Ppic et Pla4 % suggĂšre que l'endurance gĂ©nĂ©rale est en partie liĂ©e Ă l'endurance locale. Les meilleurs indices de puissance anaĂ©robie gĂ©nĂ©rale sont observĂ©s chez les sujets prĂ©sentant les indices de puissance anaĂ©robie locale les plus Ă©levĂ©s. En revanche, les indices aĂ©robies locaux et gĂ©nĂ©raux les plus Ă©levĂ©s sont observĂ©s chez les sujets prĂ©sentant les indices de puissance anaĂ©robie les plus faibles
Comparaison de performances aérobies et anaérobies aucours d'exercices locaux et généraux
International audiencePurpose: The relationships between the aerobic and anaerobic abilities for local and general exercises has been studied in twenty three subjects.Methods: Maximal aerobic power (PMA), the lactate level corresponding to 4 mmol lâ1 (Pla4) and maximal anaerobic power on a Monark cycle ergometer (general exercises) have been correlated with aerobic and anaerobic performances for knee extension exercises (local exercises). Maximal anaerobic power (Pmax) has been determined by means of a forceâvelocity test on the same Monark ergometer. Two indices of local aerobic ability were estimated: 1) the peak power (Ppic) measured at the end of an incremental knee extension exercise, 2) the knee extension critical power (PC) calculated as equal to the slope of the relationship between exhaustion time and total work performed during three exhaustives exercises at constant load. Maximal anaerobic power of the knee extensors was determined by measuring the maximal power at an angular velocitie of 240° sâ1 (Pbiodex) with an isokinetic ergometer.Results: The correlations between all the indices of local and general aerobic abilities were highly significant (0.82<r<0.96; p<0.001) whatever the expression of the data (absolute values or related to the quadriceps muscle mass). The relationship between PC and Pla4 was significant even when these variables were expressed as fractions of the maximal aerobic power (PC/Ppic and Pla4%: r=0.75; p<0.001). Similarly, Pmax and Pbiodex were correlated even when related to quadriceps muscle mass (r=0.60; p<0.01). In contrast to Pmax, Pbiodex was negatively correlated with the local and general aerobic indices, but only when these variables was related to quadriceps muscle mass (0.44<r<0.63; p<0.05).Conclusions: The general aerobic abilities are very well correlated with the local aerobic abilities. Moreover, the correlation between PC/Ppic and Pla4% suggests that local and the general endurances are partially linked. The best indices of maximal anaerobic power and local anaerobic power are observed in the same subjects. In contrast, the best local and general aerobic indices are observed in the subjects presenting the weakest indices of anaerobic power.Objectif: Afin de prĂ©ciser les relations entre les aptitudes physiques locales et gĂ©nĂ©rales, nous avons procĂ©dĂ© chez 23 sujets Ă l'Ă©tude des corrĂ©lations entre des indices gĂ©nĂ©raux aĂ©robies, des indices locaux aĂ©robies et les puissances maximales anaĂ©robies gĂ©nĂ©rale et locale.MĂ©thodes: Les indices gĂ©nĂ©raux aĂ©robies, reprĂ©sentĂ©s par la puissance maximale aĂ©robie (PMA) et la puissance correspondant Ă une lactatĂ©mie de 4 mmol lâ1 (Pla4), ont Ă©tĂ© dĂ©terminĂ©s Ă l'occasion d'un exercice progressif sur bicyclette ergomĂ©trique. Les indices locaux aĂ©robies ont Ă©tĂ© dĂ©terminĂ©s au moyen d'exercices rĂ©alisĂ©s sur un ergomĂštre conçu pour effectuer des extensions de jambe. Il s'agit de la puissance maximale mesurĂ©e au terme d'un exercice progressif (Ppic) et de la puissance critique (PC), calculĂ©es Ă partir de la relation qui unit le temps et le travail, Ă©tablie Ă l'issue de trois exercices Ă charge constante menĂ©s Ă Ă©puisement. Les puissances maximales anaĂ©robies gĂ©nĂ©rale et locale ont Ă©tĂ© Ă©valuĂ©es, respectivement, au moyen d'un test de charge-vitesse sur ergocycle (Pmax) et d'un test sur ergomĂštre isocinĂ©tique (Pbiodex).RĂ©sultats: Les corrĂ©lations entre toutes les variables aĂ©robies sont hautement significatives (0,82<r<0,96 ; p<0,001), qu'elles soient exprimĂ©es en valeurs absolues ou rapportĂ©es Ă la masse du quadriceps. Les fractions PC/Ppic et Pla4/PMA (Pla4 %) sont Ă©galement corrĂ©lĂ©es (r=0,75 ; p<0,001) et restent significativement corrĂ©lĂ©es aux autres variables aĂ©robies (0,58<r<0,89 ; p<0,01). Pmax et Pbiodex sont corrĂ©lĂ©es, y compris lorsque les valeurs sont rapportĂ©es Ă la masse du quadriceps (r=0,60 ; p<0,01). Ă la diffĂ©rence de Pmax, Pbiodex est nĂ©gativement et significativement corrĂ©lĂ©e aux indices aĂ©robies (Ppic, PC, PC/Ppic, PMA et Pla4 %), mais seulement lorsque les valeurs sont exprimĂ©es en fonction de la masse du quadriceps (0,44<r<0,63 ; p<0,05).Conclusions: Une cohĂ©rence est observĂ©e entre les indices aĂ©robies gĂ©nĂ©raux et locaux. La corrĂ©lation entre PC/Ppic et Pla4 % suggĂšre que l'endurance gĂ©nĂ©rale est en partie liĂ©e Ă l'endurance locale. Les meilleurs indices de puissance anaĂ©robie gĂ©nĂ©rale sont observĂ©s chez les sujets prĂ©sentant les indices de puissance anaĂ©robie locale les plus Ă©levĂ©s. En revanche, les indices aĂ©robies locaux et gĂ©nĂ©raux les plus Ă©levĂ©s sont observĂ©s chez les sujets prĂ©sentant les indices de puissance anaĂ©robie les plus faibles
Activation of Nod2 signaling upon norovirus infection enhances antiviral immunity and susceptibility to colitis
ABSTRACTOver 90% of epidemic non-bacterial gastroenteritis are caused by human noroviruses (NoVs), which persist in a substantial subset of people allowing their spread worldwide. This has led to a significant number of endemic cases and up to 70,000 children deaths in developing countries. NoVs are primarily transmitted through the fecal-oral route. To date, studies have focused on the influence of the gut microbiota on enteric viral clearance by mucosal immunity. In this study, the use of mouse norovirus S99 (MNoV_S99) and CR6 (MNoV_CR6), two persistent strains, allowed us to provide evidence that the norovirus-induced exacerbation of colitis severity relied on bacterial sensing by nucleotide-binding oligomerization domain 2 (Nod2). Consequently, Nod2-deficient mice showed reduced levels of gravity of Dextran sodium sulfate (DSS)-induced colitis with both viral strains. And MNoV_CR6 viremia was heightened in Nod2-/- mice in comparison with animals hypomorphic for Atg16l1, which are prone to aggravated inflammation under DSS. Accordingly, the infection of macrophages derived from WT mice promoted the phosphorylation of Signal Transducer and Activator of Transcription 1 (STAT1) and NOD2âs expression levels. Higher secretion of Tumor Necrosis Factor alpha (TNF[Formula: see text]) following NOD2 activation and better viral clearance were measured in these cells. By contrast, reduced levels of pSTAT1 and blunted downstream secretion of TNF[Formula: see text] were found in Nod2-deficient macrophages infected by MNoV_S99. Hence, our results uncover a previously unidentified virus-host-bacterial interplay that may represent a novel therapeutic target for treating noroviral origin gastroenteritis that may be linked with susceptibility to several common illnesses such as Crohnâs disease
Antiadhesive properties of glycoclusters against Pseudomonas aeruginosa lung infection
Pseudomonas aeruginosa lung infections are a major cause of death in cystic fibrosis and hospitalized patients. Treating these infections is becoming difficult due to the emergence of conventional antimicrobial multiresistance. While monosaccharides have proved beneficial against such bacterial lung infection, the design of several multivalent glycosylated macromolecules has been shown to be also beneficial on biofilm dispersion. In this study, calix[4]arene-based glycoclusters functionalized with galactosides or fucosides have been synthesized. The characterization of their inhibitory properties on Pseudomonas aeruginosa aggregation, biofilm formation, adhesion on epithelial cells, and destruction of alveolar tissues were performed. The antiadhesive properties of the designed glycoclusters were demonstrated through several in vitro bioassays. An in vivo mouse model of lung infection provided an almost complete protection against Pseudomonas aeruginosa with the designed glycoclusters