Inspiratory fraction as a marker of skeletal muscle dysfunction in patients with COPD

AbstractBackgroundAn inspiratory capacity to total lung capacity (IC/TLC) ratio of ≤25% has emerged as a better marker of mortality in chronic obstructive pulmonary disease (COPD) patients. The relationship among the IC/TLC ratio to lower extremity skeletal muscle function remains unknown.MethodsThirty-five men with moderate to severe COPD were divided into those with IC/TLC≤25% (n=16) and >25% (n=19). The subjects were tested for thigh muscle mass volume (MMT), maximal strength, power output of the lower extremities, and physical activity.ResultsTotal MMT in the IC/TLC<25% group was significantly lower (413.91±89.42cm3) (p<0.001) than in the IC/TLC>25% group (575.20±11.76cm3). In the IC/TLC≤25% group, maximal strength of the lower extremities and muscle peak power output of the lower extremities were 36–56% lower (p<0.01) than among the patients in the IC/TLC>25% group.ConclusionIC/TLC≤25% is associated with reduced maximal strength and peak power output of the lower extremities. IC/TLC≤25% may have an important clinical relevance as an index to determine peripheral muscle dysfunction

Efectos de realizar actividad física en la función muscular en EPOC

The purpose of this study was to examine the effects of a 12-month physical activity (PA) programme consisting in walking on muscle function in patients with COPD (Chronic Obstructive Pulmonary Disease). Forty-four men (70.3 ± 6.7 years old) diagnosed with moderate-severe COPD were recruited. The intervention group (PAG) completed a physical activity programme and the control group (COG) followed their standard treatment. Upper-and lower-limb maximum strength (1RM), lower-limb muscle power (50% and 70% 1RM) and physical activity were measured before and after 12 months. After 12 months, lower-limb maximum strength increased by 8% in the PAG (P<0.01), while it did not change in the COG. Lower-limb muscle power at 50% 1RM increased by 12% in the PAG, while it decreased by 9% in the COG (P<0.05). A physical activity programme increased muscle strength and preserved muscle power of the lower limb. © 2021, Universidad Autonoma de Madrid y CV Ciencias del Deporte. All rights reserved

Hypoxia enhances ILC3 responses through HIF-1α-dependent mechanism

Group 3 innate lymphoid cells (ILC3) have a prominent role in the maintenance of intestine mucosa homeostasis. The hypoxia-inducible factor (HIF) is an important modulator of immune cell activation and a key mechanism for cellular adaptation to oxygen deprivation. However, its role on ILC3 is not well known. In this study, we investigated how a hypoxic environment modulates ILC3 response and the subsequent participation of HIF-1 signaling in this process. We found increased proliferation and activation of intestinal ILC3 at low oxygen levels, a response that was phenocopied when HIF-1α was chemically stabilized and was reversed when HIF-1 was blocked. The increased activation of ILC3 relied on a HIF-1α-dependent transcriptional program, but not on mTOR-signaling or a switch to glycolysis. HIF-1α deficiency in RORyt compartment resulted in impaired IL-17 and IL-22 production by ILC3 in vivo, which reflected in a lower expression of their target genes in the intestinal epithelium and an increased susceptibility to Clostridiodes difficile infection. Taken together, our results show that HIF-1α activation in intestinal ILC3 is relevant for their functions in steady state and infectious conditions

Consumo, digestibilidade e parâmetros ruminais em vacas gestantes alimentadas com silagem de rama de mandioca.

O experimento foi conduzido para estudar os efeitos da substituição da silagem de milho pela silagem da rama de mandioca para vacas gestantes não-lactantes. Os níveis de substituição da silagem de milho pela silagem da rama de mandioca foram 0, 20, 40 e 60%. Foram avaliados o consumo e as digestibilidades de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), carboidratos totais (CT) e carboidratos não-fibrosos (CNF), o pH e o nitrogênio amoniacal ruminal antes e 2, 4, 6 e 8 horas depois da alimentação da manhã. Foram utilizadas quatro vacas da raça Holandesa não-lactantes e no terço final de gestação, canuladas no rúmen, distribuídas em um quadrado latino 4 × 4. Não foi observado efeito do nível de substituição da silagem de milho pela silagem da rama de mandioca sobre o consumo, a digestibilidade dos nutrientes e os parâmetros ruminais, exceto a digestibilidade aparente de proteína bruta e as concentrações de nitrogênio amoniacal. Verificou-se efeito linear negativo para digestibilidade aparente da proteína à medida que a silagem de milho foi substituída pela de rama de mandioca. Também para o nitrogênio amoniacal foi observado efeito linear negativo 8 horas pós-prandial. A substituição da silagem de milho pela silagem da rama de mandioca, em todos níveis estudados, pode ser feita na alimentação de vacas gestantes não-lactantes, pois não modifica o consumo, os parâmetros ruminais e a digestibilidade da matéria seca e dos nutrientes, exceto proteína bruta e nitrogênio amoniacal no tempo de 8 horas pós-prandial