Search results for "Respiratory Physiology"
showing 10 items of 363 documents
Multiscale Information Decomposition Dissects Control Mechanisms of Heart Rate Variability at Rest and During Physiological Stress.
2019
Heart rate variability (HRV
Thromboxane biosynthesis, neutrophil and coagulative activation in type IIa hypercholesterolemia
1995
SummaryThromboxane (Tx) A2 biosynthesis is enhanced in the majority of patients with type IIa hypercholesterolemia. Because blood clotting activation is an important component of the inflammatory response, involved in the initiation and progression of atherosclerotic plaques, we have investigated TxA2 biosynthesis, neutrophil activation and thrombin generation in 24 patients with type IIa hypercholesterolemia.Urinary 11-dehydro-TxB2, was significantly higher (p =0.0001) in patients than in 24 sex- and age matched healthy subjects. Similarly, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complexes and plasma elastase were significantly higher in patients than incontrols. Urinary…
Lung Injury Is a Predictor of Cerebral Hypoxia and Mortality in Traumatic Brain Injury
2020
Background: A major contributor to unfavorable outcome after traumatic brain injury (TBI) is secondary brain injury. Low brain tissue oxygen tension (PbtO2) has shown to be an independent predictor of unfavorable outcome. Although PbtO2 provides clinicians with an understanding of the ischemic and non-ischemic derangements of brain physiology, its value does not take into consideration systemic oxygenation that can influence patients' outcomes. This study analyses brain and systemic oxygenation and a number of related indices in TBI patients: PbtO2, partial arterial oxygenation pressure (PaO2), PbtO2/PaO2, ratio of PbtO2 to fraction of inspired oxygen (FiO2), and PaO2/FiO2. The primary aim …
Abdominal wall incisional hernia repair improves respiratory function: results after 3 years of follow-up
2020
Abstract Purpose Hernias severely impact patient quality of life (QoL), and 80% of patients require a surgical operation. Moreover, hernias are responsible for respiratory function alterations. This study aims to investigate the postoperative alterations in respiratory function after open ventral hernia repair in patients with incisional hernia. Methods Patients operated on at the Policlinico “Paolo Giaccone” at Palermo University Hospital between January 2015 and December 2016 were identified in a prospective database. Fifty-one patients were enrolled in the study. The respiratory outcome measures used were forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio…
Myocardial blood flow and adenosine A2Areceptor density in endurance athletes and untrained men
2008
Previous human studies have shown divergent results concerning the effects of exercise training on myocardial blood flow (MBF) at rest or during adenosine-induced hyperaemia in humans. We studied whether these responses are related to alterations in adenosine A2A receptor (A2AR) density in the left-ventricular (LV) myocardium, size and work output of the athlete's heart, or to fitness level. MBF at baseline and during intravenous adenosine infusion, and A2AR density at baseline were measured using positron emission tomography, and by a novel A2AR tracer in 10 healthy male endurance athletes (ET) and 10 healthy untrained (UT) men. Structural LV parameters were measured with echocardiography.…
Effects of PEEP on Residual Vascularization in Oesophageal Substitution Gastroplasty by Surface Oximetry-Capnometry and Photoplethysmography
2003
<i>Objective:</i> To evaluate the effects of positive end-expiratory pressure (PEEP) on residual vascularization in gastric tubes for oesophageal replacement. <i>Design:</i> Experimental open study. <i>Materials:</i> Eleven mongrel dogs. <i>Methods:</i> Intestinal parietal blood flow was evaluated by photoplethysmography (PPG) and measurement of surface oxygen (PsO<sub>2</sub>) and carbon dioxide (PsCO<sub>2</sub>) tensions under basal conditions. After Akiyama’s tubular gastroplasty, three levels of PEEP were administered. At each level, fluids were infused to counter the drop in cardiac output. PPG, surface gas tensio…
The effects of arterial CO2 on the injured brain: Two faces of the same coin
2021
Serum levels of carbon dioxide (CO2) closely regulate cerebral blood flow (CBF) and actively participate in different aspects of brain physiology such as hemodynamics, oxygenation, and metabolism. Fluctuations in the partial pressure of arterial CO2 (PaCO2) modify the aforementioned variables, and at the same time influence physiologic parameters in organs such as the lungs, heart, kidneys, and the gastrointestinal tract. In general, during acute brain injury (ABI), maintaining normal PaCO2 is the target to be achieved. Both hypercapnia and hypocapnia may comprise secondary insults and should be avoided during ABI. The risks of hypocapnia mostly outweigh the potential benefits. Therefore, i…
Tissue classification by texture and spectral analysis of intracoronary ultrasound radio-frequency data
2002
Imaging of vascular structures by intracoronary ultrasound allows in principal the recognition of different lesion types due to the echomorphology in the B-mode image. The subjective visual diagnosis is often difficult, especially the differentiation between thrombi and non-calcified plaque. The aim of this study was the extraction of features from the ultrasound radio-frequency signal for an objective characterization of coronary tissue. Methods of texture analysis and frequency analysis were used to differentiate red and white thrombi in vitro. Eight texture parameters of first and second order significantly differentiated red and white thrombi. The backscatter transfer function of red th…
Contrast-Induced Hyperemia and FFR: Slightly Slower but still “Quick and Clean”
2016
Slightly more complex than the previous one, a quick way to induce hyperemia is to inject a contrast bolus. Although the degree of hyperemia reached this way is not as large as with vasodilators, this maneuver can still allow unmasking a gradient.
Effect of a Biofeedback Intervention on Heart Rate Variability in Individuals With Panic Disorder: A Randomized Controlled Trial
2021
OBJECTIVE Some individuals with panic disorder (PD) display reduced heart rate variability, which may result in an increased risk of cardiovascular mortality. Heart rate variability-biofeedback (HRV-BF) training has been shown to improve the modulation of the autonomic activity. Therefore, this randomized controlled trial was conducted to investigate the effect of a four-week HRV-BF intervention in individuals with PD. Heart rate variability-biofeedback (HRV-BF) training improved the modulation of the autonomic activity. Therefore, with this randomized controlled trial we aimed to investigate the effect of a four-week HRV-BF intervention in people with PD. METHODS Thirty-six women and sixte…