View clinical trials related to Ischemic Preconditioning.
Filter by:Background: In plastic and reconstructive surgery, free flaps are routinely used for treatment of soft tissue defects. Treatment strategies aim at reducing or preventing flap necrosis by conditioning tissue tolerance against ischemia. Although previous studies indicate that remote ischemic preconditioning (RIPC) is a systemic phenomenon, only a few studies have focused on the elucidation of its mechanisms of action. Therefore, the aim of this study is to evaluate the microcirculatory effects of remote ischemic preconditioning on a potential free flap location in a human in-vivo setting for the first time. Conclusion: Remote ischemic preconditioning improves cutaneous tissue oxygen saturation, arterial capillary blood flow and postcapillary venous flow in a remote free flap donor location. To what extent remote preconditioning might ameliorate the reperfusion injury of free flap transplantation, further clinical trials have to evaluate both in the means of microcirculatory assessment and partial or total flap loss as end points of these studies.
Numerous studies Have shown that limb ischemic preconditioning can protect vital organs (including the heart) from ischemia-reperfusion injury,which has a broad application prospect.But its mechanism is still unclear. Evidence showed that humoral mechanisms may play an important role. This study was carried out on the limb ischemic preconditioning in healthy volunteers, collected their serum at different time points before and after treatment,classified and identified the serum proteins during different periods of limb ischemic preconditioning,by using methods including high abundant protein removal,Two-dimensional electrophoresis chromatography and mass spectrometry,then analysed activation and synthesis of the proteins in order to search for the proteins or peptides whose synthesis was activated by ischemic preconditioning. This study will be the first systemic explore of the changes in serum proteins of limb ischemic preconditioning in human body,and lay theoretical basis for the clinical application of limb ischemic preconditioning and for further explore of its humoral mechanism,thus provide clues for searching for protein or peptide having protective effects for organs.
Acute kidney injury is associated with cardiopulmonary bypass during heart surgery and its pathogenesis is similar to that of ischemia-reperfusion injury. Remote ischemic preconditioning attenuates myocardial ischemia-reperfusion injury in patients undergoing coronary bypass surgery. The investigators hypothesize that such preconditioning reduces the incidence of acute kidney injury associated with cardiopulmonary bypass.
This study will develop a model system that can be used to test medications for improving the ability of blood vessels to resist damage from diseases such as heart attack and stroke. The endothelium (inner layer of blood vessels) has built-in defense mechanisms to prevent blockage of blood flow, including the ability to stretch the vessel when it senses that blood flow is threatened. People with heart attack risk factors, such as high cholesterol, smoking and diabetes lose this ability. This study will develop a model that can measure the response to a lack of blood flow in the arm and be used to test new medicines to improve blood vessel health. Healthy males between 18 and 45 years of age who have no history of high blood pressure, high cholesterol, or diabetes and who have not smoked for at least 3 months before entering the study may be eligible to enroll. Participants lie in an adjustable reclining bed. Small catheters (tubes) are placed in the artery and vein of the forearm of the non-dominant arm at the inside of the elbow. Blood samples are collected from the tubes. Then, pressure cuffs are placed on both wrists and upper arms. A strain gauge (rubber band-type device) is placed around the forearms. The pressure cuffs are inflated and blood flows into the forearm, stretching the strain gauge at a rate proportional to the blood flow. Then, small doses of acetylcholine (a medicine that causes blood vessels to expand) are injected into the artery tube. After 20 minutes, blood flow to the non-dominant arm is blocked by inflating the pressure cuff. The subject squeezes a rubber ball about every 2 seconds for 90 seconds. The cuff is deflated after 15 minutes and blood samples are withdrawn from the tube in the vein. After 15 minutes, the procedure is repeated one more time.
Ischaemic preconditioning (IP) describes the phenomenon that brief periods of ischaemia render the (myocardial) muscle more resistant to a subsequent more prolonged period of ischaemia and reperfusion. Animal studies have provided evidence that adenosine receptor stimulation is an important mediator of IP. As caffeine is an effective adenosine receptor antagonist already at concentrations reached after regular coffee consumption, we aimed to assess whether caffeine impairs IP in humans in vivo. We used a novel and well-validated model to study IP in humans: 99m-Tc-annexin A5 scintigraphy in forearm skeletal muscle. 24 healthy volunteers were randomly assigned to either caffeine (4 mg/kg/iv in 10 minutes) or saline before a protocol for IP.