Search results for "Pressure"
showing 10 items of 4493 documents
Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups☆
2013
Background Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. Objectives To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. Material and methods Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glut…
Right Ventricular Dysfunction Staging System for Mortality Risk Stratification in Heart Failure with Preserved Ejection Fraction
2020
Right ventricular dysfunction (RVD) parameters are increasingly important features in heart failure with preserved ejection fraction (HFpEF). We sought to evaluate the prognostic impact of a progressive RVD staging system by combining the tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (TAPSE/PASP) ratio with functional tricuspid regurgitation (TR) severity. We prospectively included 1355 consecutive HFpEF patients discharged for acute heart failure (HF). Of them, in 471 (34.7%) patients, PASP could not be accurately measured, leaving the final sample size to be 884 patients. Patients were categorized as Stage 1: TAPSE/PASP &ge
The effects of regular sauna bathing in conjunction with exercise on cardiovascular function : A multi-arm randomized controlled trial
2022
Regular exercise and sauna bathing have each been shown to improve cardiovascular function in clinical populations. However, experimental data on the cardiovascular adaptations to regular exercise in conjunction with sauna bathing in the general population is lacking. Therefore, we compared the effects of exercise and sauna bathing, to regular exercise using a multi-arm randomized controlled trial. Participants (n = 47) aged 49 ± 9 years with low physical activity levels, and at least one traditional CVD risk factor were randomly assigned (1:1:1) to guideline-based regular exercise and 15-minute post-exercise sauna (EXS), guideline-based regular exercise (EXE), or control (CON), for eight w…
Hepatitis C virus co-infection and sexual risk behaviour are associated with a high homocysteine serum level in HIV-infected patients.
2012
BACKGROUND AND AIMS: A better understanding of the relationship of homocysteine with cardiovascular risk factors is needed. The objectives of this study were to assess the serum level of homocysteine in HIV-infected patients and to analyse the possible association of increased levels of the amino acid with cardiovascular risk factors, demographic and clinical characteristics of participants. METHODS: Cross-sectional study carried out as a supplementary task to the usual controls necessary in HIV-infected patients in the outpatient clinic of the Hospital General of Castellon, Spain. For two consecutive visits the demographic, clinical and HIV-related characteristics and blood analyses result…
Aggregation properties of proteins under high pressure
2010
Fourier transform infrared spectroscopy (FTIR) coupled with High Pressure (HP) techniques is a suitable tool to investigate unfolding/misfolding processes providing useful information on the kinetics of aggregation of proteins[1]. Since HP affects only the volume contribution to the Gibbs free energy, it is able to perturb the structure of proteins in a reversible way [2][3]. The principle governing pressure effects is that it tends to shift a system towards the state that occupies the smallest volume, it causes the electrostriction of charged and polar groups, the elimination of packing defects, and the solvation of hydrophobic groups. Cavities and packing defects are expected to be major …
Infrared HP study of protein folding and aggregation @ the SISSI Elettra beamline
2010
Fourier transform infrared spectroscopy (FTIR) coupled with High Hydrostatic Pressure technology is a suitable technique to investigate unfolding/misfolding processes providing useful information on the kinetics of aggregation of proteins. Since HHP doesn't affect the enthalpic contribution to the Gibbs free energy, it is able to perturb the secondary structure of proteins in a reversible way . The principle governing pressure effects is that it tends to shift a system towards the state that occupies the smallest volume, it causes the electrostriction of charged and polar groups, the elimination of packing defects, and the solvation of hydrophobic groups. Cavities and packing defects are ex…
FTIR studies of the high pressure dissociation of insulin and alpha-synuclein amyloids
2012
Amyloid fibrils are highly ordered aggregates whose formation occurs during the development of several serious disorders, like Althzeimer's and Parkinson's diseases. Even if most biophysical investigations of fibril formation have attempted to elucidate the structural events that occur during amyloid fibril assembly, relatively little is known about the thermodynamics of the aggregated protein state, and the kinetic mechanisms of its formation. Fibrillation is an irreversible process and a key challenge for the field is the development of therapeutic strategies able to inhibit or reverse the aggregation. The coupling of conventional Fourier Transform Infrared Spectroscopy (FTIR) and high Pr…
Separating the Mechanism-Based and Off-Target Actions of Cholesteryl Ester Transfer Protein Inhibitors With CETP Gene Polymorphisms
2010
Background— Cholesteryl ester transfer protein (CETP) inhibitors raise high-density lipoprotein (HDL) cholesterol, but torcetrapib, the first-in-class inhibitor tested in a large outcome trial, caused an unexpected blood pressure elevation and increased cardiovascular events. Whether the hypertensive effect resulted from CETP inhibition or an off-target action of torcetrapib has been debated. We hypothesized that common single-nucleotide polymorphisms in the CETP gene could help distinguish mechanism-based from off-target actions of CETP inhibitors to inform on the validity of CETP as a therapeutic target. Methods and Results— We compared the effect of CETP single-nucleotide polymorphisms …
Pigments and their solubility in and extractability by supercritical CO2 - I: the case of curcumin
2000
A specially designed high-pressure cell was used simultaneously as extractor/autoclave and photometric cell in a Perkin Elmer Lambda 5 spectrophotometer. Based on this cell, a simple method was developed to determine the extractability of pigments by pure and by modified supercritical (sc) CO2. The method is demonstrated with curcumin from turmeric. With sc CO2 modified by 10% ethanol, the extraction yield for curcumin from two commercial finely ground dry turmeric samples was about 100%, measured by reference to the (complete) extraction of samples of the same charge with pure ethanol under standard conditions. Extractable curcumin content was from 1.8 to 2.5%, with three samples of turmer…
Cannabinoid 1/2 Receptor Activation Induces Strain-Dependent Behavioral and Neurochemical Changes in Genetic Absence Epilepsy Rats From Strasbourg an…
2022
Childhood absence epilepsy (CAE) is characterized by absence seizures, which are episodes of lack of consciousness accompanied by electrographic spike-wave discharges. About 60% of children and adolescents with absence seizures are affected by major neuropsychological comorbidities, including anxiety. Endocannabinoids and monoamines are likely involved in the pathophysiology of these CAE psychiatric comorbidities. Here, we show that the synthetic cannabinoid receptor type 1/2 (CB1/2R) agonist WIN 55,212-2 (2 mg/kg) has a strain-dependent effect on anxiety-like and motor behavior when assess in the hole board test and cerebral monoaminergic levels in Genetic Absence Epilepsy Rats from Strasb…