Dataset Information

Protective effect of remote limb ischemic perconditioning on the liver grafts of rats with a novel model.

ABSTRACT:

Background

Remote ischemic conditioning (RIC) is a known manual conditioning to decrease ischemic reperfusion injury (IRI) but not increase ischemic time. Here we tried to establish a rat RIC model of liver transplantation (LT), optimize the applicable protocols and investigate the protective mechanism.

Methods

The RIC model was developed by a standard tourniquet. Sprague-Dawley rats were assigned randomly to the sham operated control (N), standard rat liver transplantation (OLT) and RIC groups. According to the different protocols, RIC group was divided into 3 subgroups (10 min×3, n = 6; 5 min×3, n = 6; 1 min×3, n = 6) respectively. Serum transaminases (ALT, AST), creatine kinase (CK), histopathologic changes, malondialdehyde (MDA), myeloperoxidase (MPO) and expressions of p-Akt were evaluated.

Results

Compared with the OLT group, the grafts subjected to RIC 5min*3 algorithm showed significant reduction of morphological damage and improved the graft function. Also, production of reactive oxygen species (MDA) and neutrophil accumulation (MPO) were markedly depressed and p-Akt was upregulated.

Conclusion

In conclusion, we successfully established a novel model of RIC in rat LT, the optimal RIC 5min*3 algorithm seemed to be more efficient to alleviate IRI of the liver graft in both functional and morphological categories, which due to its antioxidative, anti-inflammation activities and activating PI3K Akt pathway.

SUBMITTER: Jia J

PROVIDER: S-EPMC4364967 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Rationale: Remote ischemic perconditioning during cerebral ischemia (RIPerC) refers to the application of brief episodes of transient limb ischemia commonly to a limb, it represents a new safe, simple and low-cost paradigm in neuroprotection. Aim and/or Hypothesis: To evaluate the effects of RIPerC on acute ischemic stroke (AIS) patients, applied in the ambulance, to improve functional outcomes compared with standard of care. Sample Size Estimates: A sample size of 286 patients in each arm achieves 80% power to detect treatment differences of 14% in the outcome, using a two-sided binomial test at significance level of 0.05, assuming that 40% of the control patients will experience good outcome and an initial misdiagnosis rate of 29%. Methods and Design: We aim to conduct a multicentre study of pre-hospital RIPerC application in AIS patients. A total of 572 adult patients diagnosed of suspected clinical stroke within 8 h of symptom onset and clinical deficit >0 according to prehospital rapid arterial occlusion evaluation (RACE) scale score will be randomized, in blocks of size 4, to RIPerC or sham. Patients will be stratified by RACE score scale. RIPerC will be started in the ambulance before hospital admission and continued in the hospital if necessary. It will consist of five cycles of electronic tourniquet inflation and deflation (5 min each). The cuff pressure for RIPerC will be 200 mmHg during inflation. Sham will only simulate vibration of the device. Study Outcome(s): The primary outcome will be the difference in the proportion of patients with good outcomes as defined by a mRS score of 2 or less at 90 days. Secondary outcomes to be monitored will include early neurological improvement rate, treatment related serious adverse event rates, size of the infarct volume, symptomatic intracranial hemorrhage, metabolomic and lipidomic response to RIPerC and Neuropsychological evaluation at 90 days. Discussion: Neuroprotective therapies could not only increase the benefits of available reperfusion therapies among AIS patients but also provide an option for patients who are not candidates for these treatments. REMOTE-CAT will investigate the clinical benefit of RIC as a new neuroprotective strategy in AIS. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03375762.

Project description:ImportanceTreatment with remote ischemic perconditioning has been reported to reduce brain infarction volume in animal models of stroke. Whether this neuroprotective effect was observed in patients with acute ischemic stroke remains unknown.ObjectiveTo determine whether treatment with remote ischemic perconditioning administered to the leg of patients with acute ischemic stroke can reduce brain infarction volume growth.Design, setting, and participantsThis proof-of-concept multicenter prospective randomized open-label with blinded end point clinical trial was performed from January 12, 2015, to May 2, 2018. Patients were recruited from 11 stroke centers in France. Of the 188 patients who received magnetic resonance imaging within 6 hours of symptom onset and were confirmed to have carotid ischemic stroke, 93 were randomized to receive treatment with lower-limb remote ischemic perconditioning in addition to standard care (the intervention group), and 95 were randomized to receive standard care alone (the control group).InterventionsRandomization on a 1:1 ratio to receive treatment with remote ischemic perconditioning (4 cycles of 5-minute inflations and 5-minute deflations to the thigh to 110 mm Hg above systolic blood pressure) in addition to standard care or standard care alone.Main outcomes and measuresThe change in brain infarction volume growth between baseline and 24 hours, measured by a diffusion-weighted sequence of magnetic resonance imaging scans of the brain.ResultsA total of 188 patients (mean [SD] age, 67.2 [15.7] years; 98 men [52.1%]) were included in this intention-to-treat analysis. At hospital admission, the median National Institutes of Health Stroke Scale score was 10 (interquartile range [IQR], 6-16) and the median brain infarction volume was 11.4 cm3 (IQR, 3.6-35.8 cm3); 164 patients (87.2%) received intravenous thrombolysis, and 64 patients (34.0%) underwent mechanical thrombectomy. The median increase in brain infarction growth was 0.30 cm3 (IQR, 0.11-0.48 cm3) in the intervention group and 0.37 cm3 (IQR, 0.19-0.55 cm3) in the control group (mean between-group difference on loge-transformed change, -0.07; 95% CI, -0.33 to 0.18; P = .57). An excellent outcome (defined as a score of 0-1 on the 90-day modified Rankin Scale or a score equal to the prestroke modified Rankin Scale score) was observed in 46 of 90 patients (51.1%) in the intervention group and 37 of 91 patients (40.7%) in the control group (P = .12). No significant differences in 90-day mortality were observed between the intervention and control groups (14 of 90 patients; Kaplan-Meier estimate, 15.8% vs 10 of 91 patients; Kaplan-Meier estimate, 10.4%, respectively; P = .45) or with symptomatic intracerebral hemorrhage (4 of 88 patients [4.5%] in both groups; P = .97).Conclusions and relevanceIn this study, treatment with remote ischemic perconditioning, during or after reperfusion therapies, had no significant effect on brain infarction volume growth at 24 hours after symptom onset.Trial registrationClinicalTrials.gov Identifier: NCT02189928.

Project description:BACKGROUND:Remote ischemic conditioning during cerebral ischemia (remote ischemic perconditioning, RIPerC) refers to the application of several cycles of brief ischemia and reperfusion (I/R) commonly to a limb, and it represents a new paradigm in neuroprotection with multiple mechanisms of action in ischemic stroke (IS) patients during acute phase. Some clinical trials just finished, and a few others are still ongoing; gather the current knowledge and pull it down to influence the present and future studies was the goal of this paper. METHODS:A systematic review of published research papers and/or registered clinical trials since 2000 was performed. RESULTS:Nineteen studies were identified and only four studies were completed. All of them have demonstrated that RIPerC is safe, feasible and well tolerated in IS patients. However, a high heterogeneity of clinical trial characteristics was observed: five (26.3%) randomized clinical trials (RCTs) included only thrombolytic-treated patients, three (15.8%) RCTs only thrombectomy-treated patients, and five (26.3%) RCTs required radiological confirmation of IS. Temporal inclusion criteria vary from 4 h to 48 h. Most of the clinical trials used 4 cycles of RIPerC in the upper non-affected limb. Interestingly, only three (16.7%) RCTs applied RIPerC during the transportation in the ambulance. Neuroimaging outputs were the main endpoints when endovascular therapy was applied; functional outcome is also the main endpoint in large-medium size studies. CONCLUSIONS:This review summarizes the completed and ongoing clinical trials on RIPerC in IS patients, where RIPerC has been used alone or in combination with recanalization therapies. Ongoing clinical trials will provide new information on the best RIPerC intervention strategy and potentially improve the functional outcome of IS patients; definition of new RIPerC strategies would ideally aim at enhancing tissue preservation, promoting neurological recovery, and stratify patients to improve treatment feasibility.