ventilatory muscle

OBJECTIVE: To investigate the mechanism through which Astragalus and Panax notoginseng decoction (APD) facilitates the treatment of ferroptosis-mediated pulmonary fibrosis. MATERIALS AND METHODS: First, the electromedical measurement systems were used to measure respiratory function in mice; the lungs were then collected for histological staining. Potential pharmacologic targets were predicted via network pharmacology. Finally, tests including immunohistochemistry, reverse transcription-quantitative polymerase chain reaction, and western blotting were used to evaluate the relative expression levels of collagen, transforming growth factor β , α -smooth muscle actin, hydroxyproline, and ferroptosis-related genes (GPX4, SLC7A11, ACSL4, and PTGS2) and candidates involved in the mediation of pathways associated with ferroptosis (Hif-1 α and EGFR)...

BACKGROUND: In 2013, a new predictor of successful mechanical ventilation liberation named timed inspiratory effort (TIE) index was devised with the normalization of the maximum inspiratory pressure (obtained within 60 s of unidirectional airway occlusion) with the time at which the value was reached. The aim of this study was to verify whether the presence of a sequence of a certain number of inspiratory effort values between 30-60 s > 1.0 cm H2 O/s could predict weaning success in a performance comparable to the TIE index...

STUDY OBJECTIVES: To assess whether critical pathophysiological phenotypes predict treatment response in patients with obstructive sleep apnea (OSA) using a mandibular advancement device (MAD). METHODS: Thirty-one OSA patients were treated with a MAD. Individuals were categorized and graded into four pathophysiological phenotypes based on polysomnographic features (anatomical, ventilatory control, arousal threshold and muscle responsiveness). Morphoanthropometric data were additionally assessed...

PURPOSE: Power output at the moderate-to-heavy-intensity transition decreases during prolonged exercise, and resilience to this has been termed 'durability'. The purpose of this study was to assess the relationship between durability and the effect of prolonged exercise on severe-intensity performance, and explore intramuscular correlates of durability. METHODS: On separate days, 13 well-trained cyclists and triathletes (V̇O2 peak, 57.3 ± 4...

This study aimed to monitor the clinical and functional progression of patients with amyotrophic lateral sclerosis (ALS) and adjust ventilatory support during the COVID-19 pandemic in Brazil using telemedicine. This longitudinal case series included five evaluations from January 2019 to June 2021. The first and second assessments were performed in person and consisted of pulmonary function, respiratory muscle strength, functionality (ALS Functional Rating Scale-Revised [ALSFRS-R]) and disease staging (King's College criteria)...

This study investigated the impact of basketball-induced fatigue on 3-point jump shooting accuracy, the ball's entry angle (EA) into the hoop, shot release time (RT), their relationship with player positions in high-level basketball, and the correlation between cardiorespiratory fitness markers and potential shooting performance changes. Guards (n = 13), forwards (n = 13), and centers (n = 12) underwent physiological assessments. Sequentially, they performed 15 jump shots (PRE), a basketball exercise simulation (BEST) involving 24 × 30 s circuit activities, and a repeated shooting test (POST)...

Sarcopenia, a clinical syndrome primarily associated with reduced muscle mass in the elderly, has a negative impact on quality of life and survival. It can occur secondarily to other diseases such as heart failure (HF), a complex clinical syndrome with high morbidity and mortality. The simultaneous occurrence of these two conditions can worsen the prognosis of their carriers, especially in the most severe cases of HF, as in patients with reduced left ventricular ejection fraction (LVEF). However, due to the heterogeneous diagnostic criteria for sarcopenia, estimates of its prevalence present a wide variation, leading to new criteria having been recently proposed for its diagnosis, emphasizing muscle strength and function rather than skeletal muscle mass...

PURPOSE: Endurance sports performance is influenced by several factors, including maximal oxygen uptake (⩒O2 max), the percentage of ⩒O2 max that can be sustained in endurance events, running economy, and body composition. Traditionally, ⩒O2 max can be measured as an absolute value, adjusted for body mass, reflecting the athlete's central capacity (maximal cardiac output), or adjusted for lean mass (LM), reflecting the athlete's peripheral capacity (muscular oxidative capacity)...

Exercise limitation is a characteristic feature of chronic respiratory diseases such as COPD and is associated with poor outcomes including decreased functional status and health-related quality of life and increased mortality. The mechanisms responsible for exercise limitation are complex and include ventilatory limitation, cardiovascular impairment, and skeletal muscle dysfunction. In addition, comorbidities such as cardiovascular disease are common in this population and can further impact exercise capacity...

We investigated whether a single heart rate clamped cycling session under systemic hypoxia affects the recovery of physical and psycho-physiological responses from residual fatigue compared to normoxia. On separate occasions, twelve trained males performed a 3-d acute training camp scenario. On days 1 and 3, participants cycled for 60 min at a constant heart rate (80% of ventilatory threshold). On day 2, fatigue was induced through a simulated team game circuit (STGC), followed by a 60-min intervention of either: (1) heart rate clamped cycling in normoxia; (2) heart rate clamped cycling in hypoxia (simulated altitude ~ 3500 m); or (3) no cycling...

BACKGROUND/OBJECTIVES: Respiratory muscle training (RMT) was recognized as an effective means to improve respiratory muscle (RM) strength and enhance exercise performance. The purpose of this study was to examine the effect of low-intensity RMT on RM strength, pulmonary function, and performance. METHODS: Fourteen healthy active adults were assigned randomly to either a training or placebo group. The training group completed six weeks of RMT, which consisted of a first week, 1 set of 15 min/d, 5 d/wk at 10-25% of maximal inspiratory pressure (PImax), and the remaining 5 weeks, 2 sets of 15 min/d, 5 d/wk, at 30% PImax...

Cervical spinal cord injury impacts ventilatory and non-ventilatory functions of the diaphragm muscle (DIAm) and contributes to clinical morbidity and mortality in the afflicted population. Periodically, integrated brainstem neural circuit activity drives the DIAm to generate a markedly augmented effort or sigh-which plays an important role in preventing atelectasis and thus maintaining lung function. Across species, the general pattern of DIAm efforts during a normal sigh is variable in amplitude and the extent of post-sigh "apnea" (i...

BACKGROUND: The partial pressure of end-tidal oxygen (PETO2 ) and end-tidal oxygen concentration (ETO2 ) are among the indices that can be measured by exhaled gas analysis. Several observational studies have shown that skeletal muscle function is impaired in patients with cardiac disease; thus, the assessment of skeletal muscle function is important. Additionally, although it has recently been suggested that the difference in PETO2 from rest to the ventilatory anaerobic threshold (VAT) reflects oxygen availability in peripheral factors, primarily skeletal muscle, the evidence for this is not well established...

BACKGROUND: As the most common subtype of adult muscular dystrophy worldwide, large cohort reports on myotonic dystrophy type I (DM1) in China are still lacking. This study aims to analyze the genetic and clinical characteristics of Chinese Han DM1 patients. METHODS: Based on the multicenter collaborating effort of the Pan-Yangtze River Delta Alliance for Neuromuscular Disorders, patients with suspected clinical diagnoses of DM1 were genetically confirmed from January 2020 to April 2023...

A given dose of hypoxia causes a greater increase in pulmonary ventilation during physical exercise than during rest, representing an exercise-induced potentiation of the acute hypoxic ventilatory response (HVR). This phenomenon occurs independently from hypoxic blood entering the contracting skeletal muscle circulation or metabolic byproducts leaving skeletal muscles, supporting the contention that neural mechanisms per se can mediate the HVR when humoral mechanisms are not at play. However, multiple neural mechanisms might be interacting intricately...

BACKGROUND: The goal of this study was to verify whether anthropometric, physiological and neuromuscular factors, as well as training characteristics, could predict cycling performance during maximal incremental and time-to-exhaustion tests. METHODS: Twenty cyclists were evaluated: Anthropometric variables, knee extensor muscle activation and architecture, training history, and training volume were assessed. Second ventilatory threshold (VT<inf>2</inf>), maximal oxygen uptake (VO<inf>2MAX</inf>), and maximal power output (PO<inf>MAX</inf>) were assessed during the incremental test...

AIM: This study aims to compare the outcome of neonatal left congenital diaphragmatic hernia (CDH, Bochdalek type) repair through laparotomy with and without abdominal muscle closure. MATERIALS AND METHODS: This retrospective study was conducted between January 2012 and May 2021 at a neonatal surgical unit of a Tertiary Care Center. Demographic details, preoperative management, Two-dimensional-echo, intra-operative findings, postoperative course, and follow-up data were collected and analyzed...

INTRODUCTION AND OBJECTIVES: The human congenital central hypoventilation syndrome (CCHS) is caused by mutations in the PHOX2B (paired-like homeobox 2B) gene. Genetically engineered PHOX2B rodents exhibit defective development of the brainstem retrotrapezoid nucleus (RTN), a carbon dioxide sensitive structure that critically controls expiratory muscle recruitment. This has been linked to a blunted exercise ventilatory response. Whether this can be extrapolated to human CCHS is unknown and represents the objective of this study...

Data on exercise tolerance of children born non-extremely preterm are sparse. We aimed to explore the cardiopulmonary exercise testing (CPET) characteristics in this population. We studied 63 children (age 7-12 years) born at 290/7 -366/7 weeks of gestation (34 were late preterm, 29 were preterm) and 63 age-matched, term-born controls. All performed spirometry and CPET (cycle ergometry). There were no differences in activity levels and spirometric parameters between the group of preterm-born children and controls...

Transmembrane prolyl 4-hydroxylase (P4H-TM) is an enigmatic enzyme whose cellular function and primary substrate remain to be identified. Its loss-of-function mutations cause a severe neurological HIDEA syndrome with hypotonia, intellectual disability, dysautonomia and hypoventilation. Previously, P4H-TM deficiency in mice was associated with reduced atherogenesis and lower serum triglyceride levels. Here, we characterized the glucose and lipid metabolism of P4h-tm-/- mice in physiological and tissue analyses...