View clinical trials related to Ischemia Reperfusion Injury.
Filter by:The purpose of this study is to evaluate the safety of vardenafil in cardiac surgery patients.
The purpose of this study is to determine if anti-thymocyte globulin (Thymoglobuline) administration in the kidney transplant recipient is able to reduce the amount of damage that kidneys transplanted from deceased donors sustains on reperfusion.
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.
In this study, the researchers propose to investigate the efficacy of inhaled nitric oxide to prevent ischemia-reperfusion (I/R) hepatocyte injury in patients who receive extended donor criteria(EDC)liver grafts based on changes in proteomic and metabolomic markers following revascularization of the donor graft. In reviewing the literature, no uniform extended criteria donor classification exists. The characteristics most associated with liver graft failure appear to be cold ischemia time greater than 10 hours, warm ischemia time greater than 40 minutes, donor age > 55 years of age, donor hospitalization > 5 days, a donation after cardiac death (DCD) graft, and a split graft. The researchers will exclude warm ischemia time as this is impossible to predict prior to the transplantation. Any donor meeting at least one of the other criteria will be classified as an EDC donor. Hypothesis 1: Inhaled nitric oxide will improve overall outcome of liver recipients after EDC liver transplantation - Suppression of oxidative injury will improve graft function postoperatively as measured by International Normalized Ratio (INR) bilirubin, transaminases, and duration of hospital stay. Hypothesis 2: The mechanisms of therapeutic efficacy of inhaled nitric oxide is based on reduction in post-reperfusion oxidative injury as readily measured by the detectable changes in the protein and metabolic profiles in plasma of patients treated with inhaled-NO - Nuclear Magnetic Resonance (NMR)-based metabolic markers (xanthine end-products, lactate, and hepatic osmolytes) that are consistent with acute liver injury will be decreased in NO-treated recipients. - Protein markers of reperfusion injury (argininosuccinate synthase (ASS) and estrogen sulfotransferase (EST-1) will be greater in the plasma of patients who are not treated with inhaled-NO - Reduced oxidative injury will be reflected by a decrease in the number of mitochondrial peroxiredoxins isoforms and the number that are oxidized in NO-treated liver recipients.
The study is designed to assess the feasibility of evaluating YSPSL for the amelioration of ischemia reperfusion injury following liver transplantation by administering YSPSL into the liver graft directly ex vivo via the portal vein and to the recipient intravenously prior to reperfusion. This study is an extension of the recent pilot study YSPSL-0002 with an almost identical study protocol. The rationale of this and the previous study is based on the recent observation that P-selectin expression has been associated in liver grafts with prolonged cold storage times and rejection. By examining biomarkers of IRI including P-selectin by immunohistochemistry and/or quantitative PCR, liver histology and hepatic blood flow using established techniques, the goal of this study is to evaluate the feasibility of using these modalities for future studies of safety and efficacy.
The project has been designed to determine whether a brief period of leg ischemia will reduce the I/R injury sustained by the liver during liver surgery and liver transplantation. Adult patients (aged above 18) for liver resection (LR group) and for orthotopic liver transplantation (OLT group) will be analysed separately. Patients from each category will be randomised to two groups - a control and a Remote IPC group. In the remote IPC group Ischemic preconditioning will be induced during surgery by applying a pneumatic tourniquet to the upper part of the right thigh and then inflating it to twice the measured systolic arterial pressure in order to occlude the blood supply of the leg for 10 minutes. The tourniquet will then be deflated for 10 minutes to reperfuse the leg. This is repeated thrice to precondition the skeletal muscles of the leg.
The restoration of normal blood flow following a period of ischemia may result in ischemia / reperfusion injury (I/RI), which is characterized by inflammation and oxidative damage to tissues. Varying degrees of I/RI occur upon reperfusion of a donor heart after cold storage. Medications containing antibodies against immune cells have been used for many years as powerful immunosuppressants. These medications, called polyclonal antibody preparations, are generally only used immediately following transplantation and/or to treat rejection. At our institution, one such antibody preparation (Thymoglobulin) is used in most pediatric heart transplant recipients for 3-5 days immediately after transplantation. Because standard immunosuppressive medications (called calcineurin inhibitors) are toxic to the kidneys, the use of Thymoglobulin allows us to delay the initiation of calcineurin inhibitors until the kidneys of completely recovered from the shock of the transplant surgery. We hypothesize that Thymoglobulin may be beneficial in reducing the damage caused by I/RI. Thus, the present study seeks to evaluate the effectiveness of an intra-operative dose of Thymoglobulin (in addition to the standard doses post-operatively) at reducing the effects of I/RI. The study will be a double-bind placebo-controlled trial involving 20 subjects. Biologic markers for I/RI will be assessed at periodic intervals for six months post-transplantation. Subjects receiving intra-operative doses of Thymoglobulin will be compared to the controls in order to assess the effectiveness of intra-operative Thymoglobulin in ameliorating the effects of I/RI.