Tissue oxygenation in peripheral muscles and functional capacity in cystic fibrosis: a cross-sectional study.

NEW FINDINGS: What is the central question of this study? How do peripheral muscle tissue oxygenation and physical conditioning levels of children and adolescents with cystic fibrosis compare to demographically matched controls? What is the main finding and its importance? Children and adolescents with cystic fibrosis consumed more oxygen, more quickly and exhibited slower recovery, demonstrating that there may have been deficiencies in oxygen supply related to both oxygen uptake and oxygen transport. ABSTRACT: Cystic fibrosis affects skeletal muscle performance and functional capacity. However, it is currently unclear how peripheral muscle behaviour is affected, especially in children and adolescents. To examine this, we compared tissue oxygenation of children and adolescents with cystic fibrosis against healthy volunteers. We also evaluated the functional capacity of participants via the modified shuttle test (MST) and assessed for associations between performance and near-infrared spectroscopy. A total of 124 participants enrolled. Participants were divided into either the cystic fibrosis group (CFG) or the healthy group (HG). Statistical comparisons between groups were evaluated with the Mann-Whitney U test and associations with functional capacity were evaluated using Spearman's correlation coefficient. CFG volunteers scored lower on the MST compared to the HG. They walked shorter distances (P = 0.001) with less efficiency because they performed the tests with a less efficient walking economy (P = 0.001) and a greater deoxyhaemoglobin concentration (P = 0.001). Further, they experienced reduced tissue oxygen saturation (P = 0.037) faster than the HG. As a result, they presented lower respiratory (P = 0.001) and lower heart (P = 0.001) rate values at the end of the MST, with a longer post-test heart rate recovery time (P = 0.005). There was a significant association between deoxygenation time and functional capacity. The CFG consumed more oxygen, more quickly, with a slower recovery, reflecting impairments in the dynamics of muscle oxygen extraction. The results suggest differences in functional capacity and haemodynamic recovery in children and adolescents with cystic fibrosis.

Antinociceptive and anti-inflammatory effects of flavonoids PMT1 and PMT2 isolated from Piper montealegreanum Yuncker (Piperaceae) in mice.

In this study, we identified the antinociceptive and anti-inflammatory effects of two flavonoids (PMT1 and PMT2) from Piper montealegreanum. The antinociceptive effect was evaluated using the classical tests: acetic acid-induced writhing, formalin and hot plate test. PMT1 and PMT2 (0.1, 1, 30 and 100 µmol/kg, i.p.) reduced the writhings, with an ID50 of 0.58 and 0.44 µmol/kg, respectively. Moreover, these flavonoids (100 µmol/kg, i.p.) inhibited paw-licking time in the neurogenic phase of the formalin test, but only PMT2 was active in the inflammatory phase. However, PMT1 and PMT2 (100 µmol/kg, i.p.) did not increase the latency time of the animals in the hot plate. In order to evaluate the anti-inflammatory effect of these flavonoids, capsaicin-induced ear oedema was carried out. Both flavonoids (100 µmol/kg, i.p.) were active in this model. These results suggest that PMT1 and PMT2 have antinociceptive and anti-inflammatory activities.