View clinical trials related to Ischemia Reperfusion Injury.
Filter by:In 2012, infants having surgery for congenital heart disease have a high survival. The investigators are now focused on improving how sick these infants become after surgery (short term outcomes) and their later neurodevelopment (long term outcomes). During heart surgery, cardiopulmonary bypass (CPB; the heart-lung machine) takes over heart function while the surgeon repairs the heart disease. During this surgery there are periods of time when the amount of blood going to the heart and brain is lower than usual, called "ischemia". Once the surgery is finished the blood going to the heart and brain is increased to normal again, called "reperfusion". This ischemia-reperfusion can cause injury to the heart, brain, and other organs, affecting the short and long term outcomes in these infants. Adult studies have shown that a short time of ischemia to the legs for 5-10 minutes [the legs are not damaged by a short time of ischemia, unlike the heart or brain], before severe ischemia to another distant vulnerable vital organ [like the heart or brain], can protect this other vital organ from ischemia-reperfusion injury. This is called "remote ischemic preconditioning" (RIPC). Our objective is to test whether RIPC before heart surgery can improve the recovery of the heart and brain after heart surgery in newborn babies with congenital heart disease. The investigators will test whether RIPC will result in lower peak lactate and troponin levels on the day after heart surgery. Lactate levels are a marker for how much the different tissues of the body suffer from ischemia-reperfusion injury. Troponin is released from damaged heart during ischemia-reperfusion. In our trial infants will be randomized to RIPC or control. This means each baby has an equal chance of being in one group or the other. The intervention group will have RIPC before surgery; the "control group" will not. The investigators hope this trial will lead to a larger study to test if RIPC results in fewer days on a breathing machine after surgery, lower mortality, and higher scores on neurodevelopmental tests at 2 years of age.
In acute myocardial infarction early restoration of coronary blood flow is the most effective strategy to limit infarct-size. Paradoxically, reperfusion itself also aggravates myocardial injury and contributes to final infarct size, a process termed 'reperfusion injury'. Ischemia and reperfusion (IR)-induced endothelial dysfunction seems to play a pivotal role in this process, resulting in vasoconstriction and reduced blood flow to the already ischemic tissue. Recently, it has been shown that the glucose-lowering drug metformin is able to limit IR-injury in murine models of myocardial infarction, probably by increased formation of the endogenous nucleoside adenosine. In the current research proposal, the investigators aim to translate this finding to the human in vivo situation, using flow-mediated dilation (FMD) of the brachial artery as a well-validated model of (endothelial) IR-injury.
Oxygen is necessary for the survival of oxygen consuming organisms. But the organisms metabolism alter the oxygen to free radicals. Free radicals are molecules which due to their structure can react with other molecules resulting in cell damage. This damage is due to several mechanisms. This is e.g what happens when human tissue is cut of from blood supply for a time, and the blood supply is again restored. The damage following the restoration of blood is known as "ischemia-reperfusion injury". The reopening of the vessels and thereby supplying oxygenated blood to the deprived tissue can in it self contribute to cell death due to excessive amounts of free radicals. Antioxidants can neutralize free radicals and thereby minimize their damage. The purpose of the investigators methodology study is to make an ischemia-reperfusion model on healthy volunteers (on the lower limb) to examine the expression of markers that are expressed in the muscle and the blood when blood supply is cut of to an area and later restored. The investigators wish to measure the product of the damage caused by free radicals and the levels of antioxidants. If the investigators can produce elevation of oxidative and inflammatory markers, this model can be used to test antioxidative intervention.
The overall purpose of this study is to evaluate the safety, pharmacokinetics and preliminary efficacy of a five-days post-operative course of Treprostinil in liver transplant patients. The hypothesis of this study is that Treprostinil can be safely administered post-operatively in liver transplant patients. Once safety is documented future studies will address its ability to ameliorate or prevent reperfusion mediated dysfunction of the liver graft and thereby reduce morbidity, leading to shorter hospital stays as compared to historical controls.
This is a blinded, placebo-controlled, randomised controlled trial looking at the effects of Heme arginate (HA) on cadaveric renal transplantation. The investigators know that HA can upregulate HO-1, which has been shown to have a protective effect on animal transplants. The investigators will be giving HA/placebo to participants prior to transplant and repeat again on day 2 post-transplant and compare outcomes.
The purpose of this study is to evaluate the safety of vardenafil in cardiac surgery patients.
In Denmark, 12.000 people a year, is struck by acute myocardial infarction. A third of these cannot be saved before treatment is possible. Despite quick and effective reperfusion of the coronary arteries using PCI (Percutaneous Coronary Intervention) after an acute ST-elevation myocardial infarction, substantial morbidity and mortality remain. Infarct size is an important determinant of the short-and long-term outcome after acute myocardial infarction. The most widely used and most effective proven therapy to limit infarct size is the early reperfusion induced by or PCI. Although beneficial in terms of myocardial salvage, reperfusion itself may contribute to additional damage of the myocardium; the damage due to the combined processes is known as "ischemia-reperfusion injury". The pathogenesis of myocardial ischemia-reperfusion injury is a multifactorial process involving the interaction of multiple mechanisms. Numerous studies indicate that there are three pivotal factors in the pathogenesis of ischemia-reperfusion injury: elevated oxidative damage, depressed energy metabolism, and altered calcium homeostasis. Partially reduced species of oxygen, including the superoxide anion radical, hydroxyl radical, and hydrogen peroxide, are generated intracellularly as by-product of oxygen metabolism. These reactive oxygen species cause peroxidation af membrane lipids, denaturation of proteins, and modification of DNA, all of which ultimately can lead to cell death. In mammals, cell damage induced by partially reduced oxygen species can also initiate local inflammatory responses, which then lead to further oxidant-mediated tissue injury. Melatonin is mainly known for its role as an endogenously produced circadian hormone. For the last twenty years, increasing evidence has proven melatonin to be a very potent direct and indirect antioxidant. Recent experimental studies have documented the beneficial effects of melatonin in reducing tissue damage and limiting cardiac pathophysiology in models of experimental ischemia-reperfusion. Primary hypothesis: Melatonin given to patients undergoing PCI can reduce the myocardial damage sustained by ischemia-reperfusion.
This study is designed to investigate the possible beneficial effects of UDCA on liver graft recovery early after adult liver transplantation.
Patients with left-colon cancer will be randomized to laparoscopic or laparotomic operation. during surgery and for 6 days after operation, intestinal oxygen tension and ischemia-reperfusion injury markers will be evaluated to understand if pneumoperitoneum is associated with reduced splanchnic blood flow and ischemia-reperfusion injury.
Rationale: Apart from their cholesterol lowering effects, statins have cholesterol‐independent pleiotropic actions, such as upregulation of 5'‐ectonucleotidase and up‐regulation of NO‐synthase that may increase tolerance against ischemia‐reperfusion injury (IR‐injury). Several animal studies have shown reduction of IR‐injury as a result of statin treatment in both the heart and the kidney. Recently the investigators have shown, using Annexin A5 targeting after voluntary ischemic exercise to assess IR‐injury, a protective effect of a 7 day oral rosuvastatin treatment. A three day treatment with atorvastatin however failed to reduce annexin targeting. Assessment of the flow mediated dilation of the brachial artery as measure of endothelial (dys)function, is a validated model to research effects of possible protective strategies and perform mechanistic experiments on IR‐injury in humans in vivo. The investigators hypothesize that pretreatment with statins can increase endothelial tolerance against ischemia and reperfusion injury. Objective: To study the protective effect of pretreatment (both 3 day and 7 day) with rosuvastatin and atorvastatin on flow mediated dilation after 15 minutes ischemia and 15 minutes reperfusion. Study design: placebo‐controlled randomised double‐blind trial Study population: Healthy volunteers, age 18‐50 Intervention: Treatment with either rosuvastatin 20 mg, atorvastatin 80mg or placebo during either 3 or 7 days Main study parameters: Difference in flow mediated dilation before and after 15 minutes ischemia. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Treatment with rosuvastatin or atorvastatin is not expected to harm the volunteers. Most reported side effects of rosuvastatin and atorvastatin are gastro‐intestinal complains and myalgia. The volunteers will not benefit directly from participating in this study.