Search results for "pressure"
showing 10 items of 4493 documents
Microbial metabolomic fingerprinting in urine after regular dealcoholized red wine consumption in humans.
2013
The regular consumption of dealcoholized red wine (DRW) has demonstrated benefits in cardiovascular risk factors. The analysis of phenolic metabolites formed in the organism, especially those that could come from microbiota metabolism, would help to understand these benefits. The aim of this study was to determine the widest urinary metabolomic fingerprinting of phenolics and microbial-derived phenolic acids (n = 61) after regular intake of DRW in men at high cardiovascular risk by UPLC-MS/MS using a targeted approach. Up to 49 metabolites, including phase II and microbial phenolic metabolites, increased after DRW consumption compared to baseline (P < 0.05). The highest percentage of increa…
Analyzing gastrocnemius EMG-activity and sway data from quiet and perturbed standing.
2007
In an experiment, we combined force plate measurements and surface EMG in studying quiet and perturbed standing, involving MS (Multiple sclerosis) and controls. The aim of this paper is to report the results thus obtained on the relation between filtered gastrocnemius (GA) EMG and the anterior-posterior center-of-pressure (A/P COP) coordinate. The main finding is the good correspondence between A/P COP and the filtered GA EMG in the low frequency range. The EMG envelope was calculated using a zero-lag filter. Combining this with time shifts around 250-350 ms produced a high correlation (85.5+/-8.4%) between the GA-EMG envelope and the A/P COP. This EMG-COP relation was closest when using a …
Quantifying Net Synergy/Redundancy of Spontaneous Variability Regulation via Predictability and Transfer Entropy Decomposition Frameworks.
2017
Objective: Indexes assessing the balance between redundancy and synergy were hypothesized to be helpful in characterizing cardiovascular control from spontaneous beat-to-beat variations of heart period (HP), systolic arterial pressure (SAP), and respiration (R). Methods: Net redundancy/synergy indexes were derived according to predictability and transfer entropy decomposition strategies via a multivariate linear regression approach. Indexes were tested in two protocols inducing modifications of the cardiovascular regulation via baroreflex loading/unloading (i.e., head-down tilt at −25° and graded head-up tilt at 15°, 30°, 45°, 60°, 75°, and 90°, respectively). The net redundancy/synergy of …
Measurement of end-tidal carbon dioxide in spontaneously breathing patients in the pre-hospital setting. A prospective evaluation of 350 patients
2002
Monitoring of end-tidal carbon dioxide (EtCO(2)) is good clinical practice in the patient who is intubated and ventilated. This study investigated the EtCO(2) values in spontaneously breathing patients treated in a physician-staffed mobile intensive care unit (MICU). This article also discusses whether EtCO(2) monitoring may have an influence on therapeutic decisions by emergency physicians by providing additional information.Over a period of 6 months, 350 spontaneously breathing patients (162 males, 137 females) were treated and transported in our MICU and monitored using a LifePak 12 monitor (EtCO(2), respiratory rate, pO(2), blood pressure, heart rate). Only 299 were enrolled in the stud…
Oxidative stress and inflammation in long-term renal transplanted hypertensives.
2006
INTRODUCTION Several studies have shown that chronic renal failure (CRF) is characterized by "accelerated atherosclerosis". More recent studies emphasize that inflammation and oxidative stress play a central role in atherosclerosis, and it is well-established that C-reactive protein (CRP) is a cardiovascular risk marker in the general population, in end-stage renal disease (ESRD) patients and in allograft recipients. METHODS We measured the serum concentration of high sensitivity CRP, TNFalpha, 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha, an in vivo oxidative stress marker) in 15 CRF patients and in 15 transplant recipients. Exclusion criteria were age 65 years, smoking, diabetes mellitus …
Influence of St John's wort on catecholamine turnover and cardiovascular regulation in humans
2004
BACKGROUND: St John's wort (Hypericum perforatum) is a popular over-the-counter antidepressant. Its antidepressive effect has been attributed in part to inhibition of monoamine transporters and monoamine oxidase, on the basis of in vitro studies. METHODS: In a double-blind, randomized, placebo-controlled, crossover study, 16 healthy subjects (11 men and 5 women; mean age, 31 +/- 5 years) ingested either St John's wort (300 mg three times daily) or placebo for 7 days. Imipramine treatment (50 mg three times daily) in 7 subjects served as a positive control. After treatment, physiologic and biochemical tests included cardiovascular reflex testing, graded head-up tilt testing, and plasma catec…
Quantification of Regional Intrapulmonary Oxygen Partial Pressure Evolution during Apnea by 3He MRI
1999
We present a new method to determine in vivo the temporal evolution of intrapulmonary oxygen concentrations by functional lung imaging with hyperpolarized (3)Helium ((3)He-->). Single-breath, single-bolus visualization of (3)He--> administered to the airspaces is used to analyze nuclear spin relaxation caused by the local oxygen partial pressure p(O(2))(t). We model the dynamics of hyperpolarization in the lung by rate equations. Based hereupon, a double acquisition technique is presented to separate depolarization by RF pulses and oxygen induced relaxation. It permits the determination of p(O(2)) with a high accuracy of up to 3% with simultaneous flip angle calibration using no additional …
Identification and quantitation of methotrexate and methotrexate metabolites in clinical high-dose therapy by high pressure liquid chromatography and…
1982
High-pressure liquid chromatography in combination with field desorption mass spectrometry as techniques of high specificity and sensitivity have been applied to the identification and quantitation of the anticancer drug methotrexate and its metabolites which occur in clinical high-dose therapy. Field desorption mass spectra of methotrexate and several methotrexate and folic acid derivatives, when investigated as free acids or ammonium salts, yield abundant protonated molecular ions and a consistent pattern of structurally significant fragments. High-pressure liquid chromatographic separation of methotrexate metabolites was performed on reverse-phase, C-18 columns using a volatile, ammonium…
The effect of olive oil polyphenols on antibodies against oxidized LDL. A randomized clinical trial
2010
summary Background & aim: Oxidized LDL (oxLDL) is a highly immunogenic particle that plays a key role in the development of atherosclerosis. Some data suggest a protective role of OxLDL autoantibodies (OLAB) in atherosclerosis. Our aim was to assess the effect of olive oil polyphenols on the immunogenicity of oxLDL to autoantibody generation. Methods: In a crossover, controlled trial, 200 healthy men were randomly assigned to 3-week sequences of 25 mL/day of 3 olive oils with high (366 mg/kg), medium (164 mg/kg), and low (2.7 mg/kg) phenolic content. Results: Plasma OLAB concentration was inversely associated with oxLDL (p < 0.001). Olive oil phenolic content increased OLAB generation, with…
The role of heterosynaptic facilitation in long-term potentiation (LTP) of human pain sensation
2008
Long-term potentiation (LTP) of nociceptive synaptic transmission induced by high-frequency electrical stimulation (HFS) predominantly modulates natural somatosensory perceptions mediated by Adelta- and Abeta-fibers in humans at the site of conditioning stimulation. The relative contribution of homo- and heterosynaptic mechanisms underlying those perceptual changes remained unclear. We therefore compared changes of the somatosensory profile between a conditioned skin site (homotopic zone) and an area adjacent to conditioning HFS (heterotopic zone). HFS of the ventral forearm in 24 healthy subjects (mean pain 41/100) led to an abrupt increase of pain to single electrical test stimuli (pain a…