Search results for "Oxygen Metabolism"
showing 10 items of 12 documents
Hypoxie et régénération cardiaque : une nouvelle approche paradoxale de la cardioprotection
2017
IF 2.331; International audience
Intraoperative monitoring of cerebral microcirculation and oxygenation--a feasibility study using a novel photo-spectrometric laser-Doppler flowmetry.
2009
The present study assesses the utility of a novel invasive device (O2C-, oxygen-to-see-device) for intraoperative measurement of the cerebral microcirculation. CO2 vasoreactivity during 2 different propofol concentrations was used to investigate changes of capillary venous cerebral blood flow (rvCBF), oxygen saturation (srvO2), and hemoglobin concentration (rvHb) during craniotomy.Thirty-four patients were randomly assigned to a low propofol (4 mg/kg/h) versus a high propofol (6 mg/kg/h) group. A fiberoptic probe was applied on the cortex next to the surgical site. Measurements were performed during lower (35 mm Hg) and higher (45 mm Hg) levels of partial pressure of carbon dioxide (paCO2).…
Bacterial sensor kinases using Fe–S cluster binding PAS or GAF domains for O2sensing
2012
[4Fe-4S](2+) clusters are used by very diverse types of bacterial sensors for response to oxygen, including DNA-binding proteins of the CRP/FNR family and sensor kinases like NreB. In NreB the cluster is bound by an input domain of the PAS type. The [4Fe-4S](2+) cluster of NreB responds to O(2) by degradation to a [2Fe-2S](2+) cluster which is labile and decomposes. NreB constitutes together with AirS the NreB/AirS family of bacterial sensor kinases that contain PAS or GAF domains for binding of [4Fe-4S](2+) or [2Fe-2S](2+) clusters and oxygen sensing. The NreB/AirS family is related to the FixL sensor kinases that use hemeB binding PAS domains for oxygen sensing.
Transcranial doppler and near infrared spectroscopy in the perioperative period
2013
Maintenance of adequate blood flow and oxygen to the brain is one of the principal endpoints of all surgery and anesthesia. During operations in general anesthesia, however, the brain is at particular risk for silent ischemia. Despite this risk, the brain still remains one of the last monitored organs in clincial anesthesiology.Transcranial Doppler (TCD) sonography and near-infrared spectroscopy (NIRS) experience a revival as these noninvasive technologies help to detect silent cerebral ischemia. TCD allows for quantification of blood flow velocities in basal intracranial arteries. TCD-derived variables such as the pulsatility index might hint toward diminished cognitive reserve or raised i…
Induction of CD36 and thrombospondin-1 in macrophages by hypoxia-inducible factor 1 and its relevance in the inflammatory process.
2012
Inflammation is part of a complex biological response of vascular tissue to pathogens or damaged cells. First inflammatory cells attempt to remove the injurious stimuli and this is followed by a healing process mediated principally by phagocytosis of senescent cells. Hypoxia and p38-MAPK are associated with inflammation, and hypoxia inducible factor 1 (HIF-1) has been detected in inflamed tissues. We aimed to analyse the role of p38-MAPK and HIF-1 in the transcriptional regulation of CD36, a class B scavenger receptor, and its ligand thrombospondin (TSP-1) in macrophages and to evaluate the involvement of this pathway in phagocytosis of apoptotic neutrophils. We have also assessed HIF-1α, p…
Increased ventilation by fish leads to a higher risk of parasitism
2014
Background: Fish are common intermediate hosts of trematode cercariae and their gills can potentially serve as important sites of penetration by these larval stages. We experimentally tested the hypothesis that volume of ventilation flow across the gills contributes to acquisition of these parasites by fish. We manipulated the intensity of ventilation by using different oxygen concentrations. Methods: Juvenile Oncorhynchus mykiss were individually exposed for 10 minutes to a standard dose of Diplostomum pseudospathaceum cercariae at three levels of oxygen concentration, 30, 60 and 90%. Ventilation amplitude (measured as a distance between left and right operculum), operculum beat rate, and …
No Sustained Improvement in Tumor Oxygenation After Localized Mild Hyperthermia
2009
This study has attempted to address the controversy concerning sustained increases in tumor oxygenation upon localized mild hyperthermia. While some previous studies have reported transient increases, others have reported persistent increases in tumor oxygenation, lasting for upto 2 days after application of mild hyperthermia. In order to determine changes in oxygenation at clinically relevant tumor temperatures, experimental tumors in rats underwent localized hyperthermia at either 40, 41.8°C or 43°C for 1 h using water-filtered infrared-A irradiation. Oxygenation was continuously measured before, during and upto 60 min after hyperthermia in the tumors of anesthetized rats using oxygen-sen…
An anti-interleukin-2 receptor drug attenuates T- helper 1 lymphocytes-mediated inflammation in an acute model of endotoxin-induced uveitis.
2014
The aim of the present study was to evaluate the anti-inflammatory efficacy of Daclizumab, an anti-interleukin-2 receptor drug, in an experimental uveitis model upon a subcutaneous injection of lipopolysaccharide into Lewis rats, a valuable model for ocular acute inflammatory processes. The integrity of the blood-aqueous barrier was assessed 24 h after endotoxin-induced uveitis by evaluating two parameters: cell count and protein concentration in aqueous humors. The histopathology of all the ocular structures (cornea, lens, sclera, choroid, retina, uvea, and anterior and posterior chambers) was also considered. Enzyme-linked immunosorbent assays of the aqueous humor samples were performed t…
Quantitative Topography of the Hemodynamic-Oxidative Metabolic Interrelation by Multispot Measurement Approach in Rat Ischemia Models
2001
We applied the multispot measurement approach for both laser Doppler (LD) and a microspectrophotometric method to measure local cerebral blood flow (1CBF) and local tissue hemoglobin oxygenation (IHbO2). We demonstrated that the current technology permits in vivo observation, allowing us to establish a close topographical relation between CBF and HbO2. We measured 1CBF by LD flowmetry and tissue HbO2 by a microspectrophotometric method at multiple corresponding locations using a “scanning” technique that employs a computer-controlled micromanipulator. CBF and HbO2 data from predefined locations were correlated to the topographical situation and then arranged in a three-dimensional (3D) imag…
How To Combine Ozone Therapies With Other Modalities For Maximum Efficacy
2018
In order to use Bio-Oxidative Therapies effectively, a small shift in thinking is needed. One needs to shift from Disease Literacy to Healing Literacy This shift in thinking leads to the inevitable conclusion that: Impaired Oxygen Signaling is the common denominator for all disease. Impaired Oxygen Signaling affects: • O2 driven energetics • O2's detergent function • O2's cellular repair function • O2's renewal function It is important to be aware of Oxygen's multiple functions in order to appreciate the importance of the role bio-oxidative therapies play in the reversal of disease conditions. In fact, no treatment…