preconditioning
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BACKGROUND: A number of 'proof-of-concept' trials suggest that remote ischaemic preconditioning (RIPC) reduces surrogate markers of end-organ injury in patients undergoing major cardiovascular surgery. To date, few studies have involved hard clinical outcomes as primary end-points. METHODS: Randomised clinical trials of RIPC in major adult cardiovascular surgery were identified by a systematic review of electronic abstract databases, conference proceedings and article reference lists. Clinical end-points were extracted from trial reports. In addition, trial principal investigators provided unpublished clinical outcome data. RESULTS: In total, 23 trials of RIPC in 2200 patients undergoing major adult cardiovascular surgery were identified. RIPC did not have a significant effect on clinical end-points (death, peri-operative myocardial infarction (MI), renal failure, stroke, mesenteric ischaemia, hospital or critical care length of stay). CONCLUSION: Pooled data from pilot trials cannot confirm that RIPC has any significant effect on clinically relevant end-points. Heterogeneity in study inclusion and exclusion criteria and in the type of preconditioning stimulus limits the potential for extrapolation at present. An effort must be made to clarify the optimal preconditioning stimulus. Following this, large-scale trials in a range of patient populations are required to ascertain the role of this simple, cost-effective intervention in routine practice.
- MeSH
- dospělí MeSH
- elektronické zdravotní záznamy * MeSH
- ischemické přivykání metody MeSH
- kardiochirurgické výkony škodlivé účinky MeSH
- kardiovaskulární nemoci diagnóza chirurgie MeSH
- lidé MeSH
- pooperační komplikace * diagnóza etiologie MeSH
- randomizované kontrolované studie jako téma metody MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- přehledy MeSH
Silymarin, a standardised extract of Silybum marianum (milk thistle), comprises mainly of silybin, with dehydrosilybin (DHSB), quercetin, taxifolin, silychristin and a number of other compounds which are known to possess a range of salutary effects. Indeed, there is evidence for their role in reducing tumour growth, preventing liver toxicity, and protecting a number of organs against ischemic damage. The hepatoprotective effects of silymarin, especially in preventing Amanita and alcohol intoxication induced damage to the liver, are a well established fact. Likewise, there is weighty evidence that silymarin possesses antimicrobial and anticancer activities. Additionally, it has emerged that in animal models, silymarin can protect the heart, brain, liver and kidneys against ischemia reperfusion injury, probably by preconditioning. The mechanisms of preconditioning are, in general, well studied, especially in the heart. On the other hand, the mechanism by which silymarin protects the heart from ischemia remains largely unexplored. This review, therefore, focuses on evaluating existing studies on silymarin induced cardioprotection in the context of the established mechanisms of preconditioning.
Introduction: Na experimentálnu verifikáciu vitality žalúdočného tubulu pred ezofagektómiou je nevyhnutná existencia jednoduchého modelu. Ischémia je hlavná príčina dehiscencie ezofagogastrickej anastomózy a následného leaku anastomózy. Ischemická príprava žalúdočného tubulu pred ezofagektómiou je potencionálna možnosť ako zamedziť rozvoju nežiaducich komplikácií. Avšak technika ako aj optimálne načasovanie ischemizácie ostávajú nejasné. Metody: Samce potkanov plemena Sprague-Dawley (n=24) boli náhodne rozdelené do štyroch skupín: ischemická skupina s odberom vzoriek po 1 hodine od ischémie (I1H), ischemická skupina s odberom vzoriek 1 deň od ischémie (I1D), ischemická skupina s odberom vzoriek 7 dní od ischémie (I7D) a kontrolná skupina (C). Ischémia bola navodená ligáciou a. gastrica sinistra a aa. gastricae breves. Vzorky boli histologicky a makroskopicky verifikované a stanovený bol počet a percentuálne zastúpenie jednotlivých imunokompetentných buniek. Výsledky: V skupine I1H bola pozorovaná ischemická denudácia s mukozálnymi eróziami a celkový počet eozinofilov bol signifikantne vyšší (p<0.05) v tejto skupine v porovnaní so skupinami I1D a I7D. V skupine I1D bola pozorovaná redukcia zápalu a parciálna regenerácia žalúdočnej mukózy. V skupine I7D bola pozorovaná takmer kompletná architektonická regenerácia žalúdočného epitelu a počet polymorfonukleárov bol signifikantne nižší (p<0,05) ako v skupine I1D. Záver: Ischemické poškodenie ligáciou žalúdočných tepien bolo predominantne pozorované v skupinách I1H a I1D avšak nie v skupine I7D. Táto práca prezentuje jednoduchú metódu verifikácie ischemických zmien žalúdočného tubulu.
Introduction: A reproducible and simple model is essential for verifying gastric conduit vitality before esophagectomy. Ischemia is a major cause of esophagogastric anastomotic dehiscence and leakage. Ischemic conditioning of the stomach prior to esophageal surgery has been shown to lower the incidence of postoperative complications, including anastomotic leakage. However, the optimal timing and technique of ischemization remain uncertain. Methods: Male Sprague-Dawley rats (n=24) were randomly divided into four groups: ischemic group – samples collected 1 hour after ischemia (I1H), ischemic group – samples collected 1 day after ischemia (I1D), ischemic group – samples collected 7 days after ischemia (I7D), and control group (C). Ischemia was induced by ligation of the left gastric (LGA) and short gastric arteries (SGA). The samples were verified using histological and macroscopic analysis, and the number and percentage of immunocompetent cells were determined. Results: One hour after ischemization (I1H), ischemic denudation with mucosal erosion was observed, and the total number of eosinophils was significantly higher (p<0.05) in the I1H group compared to the I1D and I7D groups. One day after ischemia (I1D), there was a reduction in the inflammatory response with partial regeneration of gastric mucosa. In the I7D group, nearly complete architectural regeneration of mucosal epithelium was documented. The total count of polymorphonuclears was significantly lower (p<0.05) compared to the I1D group. Conclusion: Ischemic mucosal injury after LGA and SGA ligation was observed dominantly in the I1H and I1D groups, but not in I7D group. In conclusion, this study presents a simple method for verifying gastric ischemic changes.
- MeSH
- anastomóza chirurgická * MeSH
- ezofagektomie metody MeSH
- ezofágus chirurgie krevní zásobení patologie MeSH
- ischemický postconditioning metody MeSH
- krysa rodu rattus MeSH
- netěsnost anastomózy etiologie prevence a kontrola MeSH
- potkani Sprague-Dawley MeSH
- žaludek chirurgie krevní zásobení patologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
Remote ischemic preconditioning (RIPC) is a novel strategy of protection against ischemia-reperfusion (IR) injury in the heart (and/or other organs) by brief episodes of non-lethal IR in a distant organ/tissue. Importantly, RIPC can be induced noninvasively by limitation of blood flow in the extremity implying the applicability of this method in clinical situations. RIPC (and its delayed phase) is a form of relatively short-term adaptation to ischemia, similar to ischemic PC, and likely they both share triggering mechanisms, whereas mediators and end-effectors may differ. It is hypothesized that communication between the signals triggered in the remote organs and protection in the target organ may be mediated through substances released from the preconditioned organ and transported via the circulation (humoral pathways), by neural pathways and/or via systemic anti-inflammatory and antiapoptotic response to short ischemic bouts. Identification of molecules involved in RIPC cascades may have therapeutic and diagnostic implications in the management of myocardial ischemia. Elucidation of the mechanisms of endogenous cardioprotection triggered in the remote organ could lead to the development of diverse pharmacological RIPC mimetics. In the present article, the authors provide a short overview of RIPC-induced protection, proposed underlying mechanisms and factors modulating RIPC as a promising cardioprotective strategy.
- MeSH
- ischemické přivykání metody MeSH
- lidé MeSH
- reperfuzní poškození myokardu prevence a kontrola MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
UNLABELLED: Remote ischemic preconditioning (RIP)-induced protection of myocardial energetics was well documented on the level of tissue, but data concerning the involvement of mitochondria were missing. We aimed at the identification of changes in membrane properties and respiratory functions induced in rat heart mitochondria by RIP. Experiments were performed on 46 male Wistar rats divided into control and RIP-treated groups of 21 animals each. Blood flow in the occluded area was recorded by MRI angiography in four animals. RIP protocol comprised of three successive 5-min occlusions each followed by 5-min reperfusions of descending branches of the right hind limb femoral artery. The efficacy of RIP was evaluated as the extent of RIP-induced protection against damage to the functions of mitochondria isolated by differential centrifugation after 30-min global ischemia followed by 40-min reperfusion of the hearts in Langendorff mode. ASSESSMENTS: mitochondrial membrane fluidity with a fluorescent probe DPH, CoQ(9) and CoQ(10) with HPLC, mitochondrial respiration with the Oxygraph-2k (Oroboros). Results revealed that RIP was affecting the mitochondria. The immediate protection conferred by RIP involves beneficial and prognostically significant effects: a total elimination of ischemia/reperfusion-induced depression of mitochondrial membrane fluidity and a trend for better preservation of mitochondrial state 3 respiration.
- MeSH
- buněčná membrána metabolismus MeSH
- ischemické přivykání * MeSH
- končetiny krevní zásobení MeSH
- oxidativní fosforylace MeSH
- potkani Wistar MeSH
- srdeční mitochondrie metabolismus MeSH
- transport elektronů MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Inhalational anesthetic-induced preconditioning (APC) has been shown to reduce infarct size and attenuate contractile dysfunction caused by myocardial ischemia. Only a few studies have reported the effects of APC on arrhythmias during myocardial ischemia-reperfusion injury, focusing exclusively on reperfusion. Accordingly, the aim of the present study was to examine the influence of APC on ventricular arrhythmias evoked by regional no-flow ischemia. APC was induced in adult male Wistar rats by 12-min exposures to two different concentrations (0.5 and 1.0 MAC) of isoflurane followed by 30-min wash-out periods. Ventricular arrhythmias were assessed in the isolated perfused hearts during a 45-min regional ischemia and a subsequent 15-min reperfusion. Myocardial infarct size was determined after an additional 45 min of reperfusion. The incidence, severity and duration of ventricular arrhythmias during ischemia were markedly reduced by APC. The higher concentration of isoflurane had a larger effect on the incidence of ventricular fibrillation than the lower concentration. The incidence of ventricular tachycardia and reversible ventricular fibrillation during reperfusion was also significantly reduced by APC; the same was true for myocardial infarct size. In conclusion, we have shown that preconditioning with isoflurane confers profound protection against myocardial ischemia- and reperfusion-induced arrhythmias and lethal myocardial injury.
- MeSH
- anestetika inhalační aplikace a dávkování MeSH
- fibrilace komor farmakoterapie patofyziologie MeSH
- ischemická choroba srdeční farmakoterapie patofyziologie MeSH
- ischemické přivykání metody MeSH
- krysa rodu rattus MeSH
- potkani Wistar MeSH
- reperfuzní poškození myokardu farmakoterapie patofyziologie MeSH
- srdce patofyziologie účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
