The effect of postural changes on respiration was investigated in ten anesthetized cats by applying body tilting during the inspiration phase while recording respiratory patterns, as given by the diaphragmatic EMG, together with either the lung volume or the air flow temperature. The results show that the head-up tilting during inspiration reduced the period of the inspiratory phase and increased the end-inspiratory lung volume. On the other hand, the head-down tilting during inspiration had opposite effects. These effects disappeared after transection of the vagus nerve. However, labyrinthectomy did not diminish the effects, probably because of functional suppression of the vestibular system due to the anesthetic. When correlating the activity of 15 vagal afferents presumably originating from the slowly adapting lung stretch receptors with lung volume changes during tilting, their maximum firing rate (87 +/- 15.7 Hz) was increased with an increase in the lung inflation volume and was attained earlier on head-up tilting and it was reduced with a decrease of the lung volume on head-down tilting (63 +/- 16.6 Hz) as compared with the value in the horizontal position (74 +/- 14.2 Hz). These results suggest that respiratory modulation during head-up or head-down tilting is consistent with the Hering-Breuer reflexes and minimizes the externally induced lung volume changes during postural changes.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Comprehensive Non-invasive Versus Invasive Approach to Evaluate Cardiac Allograft Vasculopathy in Heart Transplantation: The CCTA-HTx Study.
Circ Cardiovasc Imaging
January 2025
Cardiovascular Center Aalst, Onze-Lieve-Vrouwziekenhuis (OLV) Clinic, Aalst, Belgium (M. Belmonte, P.P., M.M.V., M. Beles, H.O., R.S., G.E., M.S., R.D., W.H., J.V.K., J.B., M.V.).
Background: Coronary computed tomography angiography (CCTA) is emerging as a valuable tool for noninvasive surveillance of cardiac allograft vasculopathy (CAV) in patients with heart transplant (HTx). We assessed the diagnostic performance of a comprehensive CCTA-based approach compared with the invasive reference, which includes invasive coronary angiography, intravascular ultrasound, and fractional flow reserve, for detecting CAV.
Methods: This was a multicenter prospective study including 37 patients with HTx who underwent CCTA, invasive coronary angiography, intravascular ultrasound, and fractional flow reserve.
Unlabelled: Accurate estimation of the Lung Shunt Fraction (LSF) is a standard of care in yttrium-90 ( Y) radioembolization treatment planning to prevent excessive lung irradiation due to arterio-venous shunting in the liver. LSF is assessed using Tc macroaggregated albumin ( Tc-MAA) imaging, but this approach adds risk, complexity, and expense to the treatment planning. This study investigates the potential of Contrast-Enhanced Computed Tomography (CECT) as a non-invasive alternative for LSF estimation.
View Article and Find Full Text PDFFactors associated with aspects of functioning one year after hospitalization due to COVID-19.
Clin Rehabil
January 2025
Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Objective: To identify factors, present at 3 months after COVID-19 that are associated with the level of functioning 1 year after hospitalization.
Design: Multicenter prospective observational study.
Setting: Region Västra Götaland Sweden.
Outcome and safety 90 days after combined airway valve treatment of the right upper and middle lobes in patients with severe pulmonary emphysema.
Respir Res
January 2025
Department of Pneumology and Critical Care Medicine, Thoraxklinik at the University Hospital Heidelberg, Heidelberg, Germany.
Background: In COPD patients with severe right-sided emphysema, complete major and incomplete minor fissure, implantation of one-way valves in both the right upper (RUL) and middle lobes (ML) is a possible approach for endoscopic lung volume reduction. The aim of this retrospective analysis was to evaluate the response to therapy and the complication rate at 90 days (90d-FU) after combined RUL-ML valve implantation.
Methods: This retrospective, monocentric study included all patients from the Thoraxklinik Heidelberg who underwent RUL-ML valve treatment between 2012 and 2023 with available follow-up data.
Habitat-based MRI radiomics to predict the origin of brain metastasis.
Med Phys
January 2025
Department of Scientific Research and Academic, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning, P. R. China.
Background: This study aims to explore the value of habitat-based magnetic resonance imaging (MRI) radiomics for predicting the origin of brain metastasis (BM).
Purpose: To investigate whether habitat-based radiomics can identify the metastatic tumor type of BM and whether an imaging-based model that integrates the volume of peritumoral edema (VPE) can enhance predictive performance.
Methods: A primary cohort was developed with 384 patients from two centers, which comprises 734 BM lesions.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!