Search results for "oxygenation"
showing 10 items of 237 documents
Organ Recovery Procedure in Donation After Controlled Circulatory Death with Normothermic Regional Perfusion: State of the Art
2020
The global shortage of organ donors will not be resolved solely by relying on donation after brain death. Expansion to use of donation after controlled circulatory death will be needed to address the shortfall of organs for transplantation. The processes of warm ischemia threaten the viability of organs obtained after controlled circulatory death, but these can be minimized by well-organized donation pathways and new techniques of in situ organ preservation, such as normothermic regional perfusion. The use of extracorporeal membrane oxygenation (ECMO) devices for normothermic regional perfusion in liver transplantation can help reduce rates of biliary complications, ischemic type biliary le…
A Selective Synthesis of Fluorinated Cispentacin Derivatives
2014
A facile selective method has been developed for the synthesis of new fluorine-containing cispentacin stereoisomers. Mono- and difluorinated cispentacin derivatives were synthetized from a bicyclic β-lactam in five or six steps involving a regio- and stereoselective hydroxylation through iodooxazoline formation, followed by deoxygenation by fluorination. Starting from an enantiomerically pure bicyclic β-lactam obtained by enzymatic resolution of the racemic compound, an enantiodivergent procedure allowed the preparation of both dextro- and levorotatory difluorinated cispentacins.
T helper 1 response is correlated with widespread pain, fatigue, sleeping disorders and the quality of life in patients with fibromyalgia and is modu…
2019
Hyperbaric oxygen therapy (HBOT) has been used as treatment for different clinical conditions, including fibromyalgia (FM). HBOT modulates brain activity, ameliorates chronic pain and modifies the ratio of immune cells. Clinical studies have provided evidence that FM is associated with immune system dysregulation. In the present study we aimed to evaluate the effect of HBOT on immune system and on the quality of life-style of FM patients.Patients with primary FM and controls were treated with HBOT. Physical, emotional and social assessment, quality of sleep, tender points, intensity score, WPI and symptom severity were evaluated before and after HBOT. Furthermore, a characterisation of CD4 …
Cerebral protection during fetal-to-neonatal transition under hypoxic atmosphere
2017
Newborn asphyxia is a complication during the perinatal period. The use of O2 for resuscitation has been broadly used in clinic. However, it has been demonstrated that oxygen overexposure induces oxidative stress (OS). We speculate that delaying postnatal in the extrauterine oxygenation status would preserve reducing equivalents, enhance redox adaptation, and protect oxyregulator tissues. The objective is evaluated OE status, induced by Fetal-Neonatal Transition (FNT) under different FiO2 conditions, in brain. FiO2 in pregnant mice was reduced from 21% to 14% or not the night before of delivery (G19). 8 hours after birth both group were led to room air (Hx14/21 and Nx21/21 groups) or hypero…
Effect of Cell Line and Differentiation on the Oxygenation Status of Experimental Sarcomas
1997
Since the measurement of tumor oxygenation status and the fraction of hypoxia within tumor tissue by computerized pO2-histography [10] has become increasingly im-portant in the clinical setting, many studies on tumor oxygenation in different experimental malignancies as well as in various human tumors have been carried out. Because pO2-histography is an invasive technique, this method has been used in humans mostly in superficial primary tumors and lymph node metastases [1,3,10] (for a review see [9]). Experimental studies in animals have been carried out on a wide range of isotransplanted rodent sarcomas or carcinomas [2,4,6–8,11] and of xenotransplanted human tumors [6]. The results obtai…
Effectiveness of Respiratory Hyperoxia, of Normobaric and of Hyperbaric Oxygen Atmospheres in Improving Tumor Oxygenation
1984
A restriction and an inhomogeneous distribution of diffusive and convective oxygen supply is considered the main cause for pronounced radioresistance in solid tumors (Thomlinson and Gray, 1955; Tannock, 1972). One way to alleviate this crucial problem in tumor therapy is the direct enhancement of oxygen delivery to the cancer cells. This can be performed either by the tumor host breathing pure O2 (respiratory hyperoxia, RHO) or by whole body exposure to pure O2 atmospheres at normobaric or hyperbaric pressures (normobaric oxygenation NMO, and hyperbaric oxygenation, HPO, respectively). Numerous investigations have been undertaken both in animals and in man using RHO, NMO, or HPO as an adjuv…
Pathophysiological and vascular characteristics of tumours and their importance for hyperthermia: Heterogeneity is the key issue
2010
Tumour blood flow before and during clinically relevant mild hyperthermia exhibits pronounced heterogeneity. Flow changes upon heating are not predictable and are both spatially and temporally highly variable. Flow increases may result in improved heat dissipation to the extent that therapeutically relevant tissue temperatures may not be achieved. This holds especially true for tumours or tumour regions in which flow rates are substantially higher than in the surrounding normal tissues. Changes in tumour oxygenation tend to reflect alterations in blood flow upon hyperthermia. An initial improvement in the oxygenation status, followed by a return to baseline levels (or even a drop to below b…
Tumor tissue oxygenation as evaluated by computerized-po2-histography
1990
A computerized pO2 measurement system with a novel electrode motion pattern (Sigma-pO2-histography) was evaluated in vitro and in vivo. The system was found to be reliable in 0.9% saline and 10% hydroxyethylene starch solution and in fresh donor blood. Marked deviations were found in lipid and hemoglobin solutions and in fluorocarbon emulsions. Histograms obtained in rat liver, mouse muscle, and subcutis were similar to previously reported distributions. Direct comparison between Sigma-Eppendorf and self-constructed Whalen-type electrodes in hypoxic tumors gave similar results. A large series of measurements indicated that hypoxic and anoxic tissue areas were frequently found both in isogra…
Tetrachlorodecaoxide Improves the Oxygenation Status of Multicellular Tumor Spheroids
1986
Insufficient O2 supply to solid tumors has been recognized since many years to be a crucial problem in cancer therapy. Hypoxia and anoxia may increase the resistance of tumor cells to certain antiproliferative drugs or to ionizing radiation. Numerous approaches to overcoming this problem have been reported in the literature. Efforts have been made in mainly two basic directions: (1) the development of therapeutic means which are particularly efficient in hypoxic and nutrient-deprived tissue areas or which are at least independent of the tissue oxygenation, and (2) the development of methods for improving the oxygenation status of solid tumors. Among the former approaches, the cytotoxicity o…
Effect of Localized Hyperthermia on Tumor Blood Flow and Oxygenation
1984
Hyperthermia has been shown to have a lethal effect in tumor cell cultures, particularly at temperatures above 42°C.1 Moreover, it has been demonstrated that hyperthermia retards the growth rate of certain types of malignant tumors and can be effective in completely eradicating some tumors without any major damage to normal tissue.2,3,4 The differential response of solid tumors in vivo to heat treatment in comparison to normal tissue probably results from several factors. Among these the in vivo micro-environment seems to play a decisive role. In general, the interstitial milieu of solid tumors is characterized by tissue hypoxia and anoxia5,6 and by severe tissue acidosis.7 These unfavorabl…