Effect Of Preconditioning Research Articles

(Best Student Presentation) Is Solid-Electrolyte Interphase Formation Affected by Electrode Conductivity?

Accurate analysis of the mechanism of interphase formation and its composition is imperative for the development of stable and efficient lithium/sodium-ion batteries. One of the most practically scalable ways to optimize interphase chemistry and morphology for reversible charge transport is electrolyte engineering and the application of formation protocol with specific current/voltage conditions. In this sense, the analysis of structure and dynamics within the electrode/electrolyte interface, i.e., the so-called electric-double layer, is essential to predicting the possible chemistry and mechanism of interphase formation.The latest was recently advanced by understanding the effect of electrolyte chemistry, e.g., the chemical structure of solvent and salt, their ratio, the presence of additives etc.1–4 Although, the role of electrode material is often neglected which creates an impression that both metallic and semiconductive electrodes form an identical electric-double layer within the same electrolyte, therefore, the mechanism of interphase formation should be very similar regardless of the chemical nature of the electrode.Here, we used examples of sodium-salt-containing ionic liquids and carbonate electrolytes to demonstrate that structural changes at the electrified interface are greatly affected by the dielectric nature of electrode material. The key observation is attributed to the different abilities of electrified electrodes to form van der Waals interactions with the electrolyte species. This affects the concentration of metal-anion complexes in relation to organic solvent near the electrode, therefore, different interphase chemistry will be formed (inorganic-rich vs. organic-rich), and different formation protocols must be used. For example, Fig. 1 shows the summary of this phenomenon for ionic liquid electrolytes with 50 mol% sodium bis(fluorosulfonyl)imide. Besides, metallic and semiconductive electrodes demonstrated different affinity toward polar organic solvent, i.e., ethylene carbonate, in 1.0 M NaPF6 in EC:DMC (1:1 by volume) electrolyte. This presentation will discuss the details of these fundings and introduce future applications. Fig. 1 | Schematic relationships between solid-electrolyte interphase (SEI) composition, applied current of preconditioning cycling, and dielectric nature of anode material.References Zheng, X. et al. Toward High Temperature Sodium Metal Batteries via Regulating the Electrolyte/Electrode Interfacial Chemistries. ACS Energy Lett. 7, 2032–2042 (2022).Rakov, D. A. et al. Engineering high-energy-density sodium battery anodes for improved cycling with superconcentrated ionic-liquid electrolytes. Nat. Mater. 19, 1096–1101 (2020).Rakov, D. A. et al. Polar Organic Cations at Electrified Metal with Superconcentrated Ionic Liquid Electrolyte and Implications for Sodium Metal Batteries. ACS Mater. Lett. 4, 1984–1990 (2022).Rakov, D. et al. Stable and Efficient Lithium Metal Anode Cycling through Understanding the Effects of Electrolyte Composition and Electrode Preconditioning. Chem. Mater. (2021). doi:10.1021/acs.chemmater.1c02981 Figure 1

MicroRNA-323-5p Involved in Dexmedetomidine Preconditioning Impart Neuroprotection.

Background and Objectives: Cerebral ischemia is one of the major preoperative complications. Dexmedetomidine is a well-known sedative-hypnotic agent that has potential organ-protective effects. We examine the miRNAs associated with preconditioning effects of dexmedetomidine in cerebral ischemia. Materials and Methods: Transient infarcts were induced in mice via reperfusion after temporary occlusion of one side of the middle cerebral artery. A subset of these mice was exposed to dexmedetomidine prior to cerebral infarction and miRNA profiling of the whole brain was performed. We administered dexmedetomidine and miRNA-323-5p mimic/inhibitor to oxygen-glucose deprivation/reoxygenation astrocytes. Additionally, we administered miR-323-5p mimic and inhibitor to mice via intracerebroventricular injection 2 h prior to induction of middle cerebral artery occlusion. Results: The infarct volume was significantly lower in the dexmedetomidine-preconditioned mice. Analysis of brain samples revealed an increased expression of five miRNAs and decreased expression of three miRNAs in the dexmedetomidine-pretreated group. The viability of cells significantly increased and expression of miR-323-5p was attenuated in the dexmedetomidine-treated oxygen-glucose deprivation/reoxygenation groups. Transfection with anti-miR-323-5p contributed to increased astrocyte viability. When miRNA-323-5p was injected intraventricularly, infarct volume was significantly reduced when preconditioned with the miR-323-5p inhibitor compared with mimic and negative control. Conclusions: Dexmedetomidine has a protective effect against transient neuronal ischemia-reperfusion injury and eight specific miRNAs were profiled. Also, miRNA-323-5p downregulation has a cell protective effect under ischemic conditions both in vivo and in vitro. Our findings suggest the potential of the miR-323-5p inhibitor as a therapeutic agent against cerebral infarction.

Ischemic Preconditioning, But Not Priming Exercise, Improves Exercise Performance in Trained Rock Climbers.

MacDougall, KB, McClean, ZJ, MacIntosh, BR, Fletcher, JR, and Aboodarda, SJ. Ischemic preconditioning, but not priming exercise, improves exercise performance in trained rock climbers. J Strength Cond Res 37(11): 2149-2157, 2023-To assess the effects of ischemic preconditioning (IPC) and priming exercise on exercise tolerance and performance fatigability in a rock climbing-specific task, 12 rock climbers completed familiarization and baseline tests, and constant-load hangboarding tests (including 7 seconds on and 3 seconds off at an intensity estimated to be sustained for approximately 5 minutes) under 3 conditions: (a) standardized warm-up (CON), (b) IPC, or (c) a priming warm-up (PRIME). Neuromuscular responses were assessed using the interpolated twitch technique, including maximum isometric voluntary contraction (MVC) of the finger flexors and median nerve stimulation, at baseline and after the performance trial. Muscle oxygenation was measured continuously using near-infrared spectroscopy (NIRS) across exercise. Time to task failure (T lim ) for IPC (316.4 ± 83.1 seconds) was significantly greater than CON (263.6 ± 69.2 seconds) ( p = 0.028), whereas there was no difference between CON and PRIME (258.9 ± 101.8 seconds). At task failure, there were no differences in MVC, single twitch force, or voluntary activation across conditions; however, recovery of MVC and single twitch force after the performance trial was delayed for IPC and PRIME compared with CON ( p < 0.05). Despite differences in T lim , there were no differences in any of the NIRS variables assessed. Overall, despite exercise tolerance being improved by an average of 20.0% after IPC, there were no differences in neuromuscular responses at task failure, which is in line with the notion of a critical threshold of peripheral fatigue. These results indicate that IPC may be a promising precompetition strategy for rock climbers, although further research is warranted to elucidate its mechanism of action.

Effects of remote ischemic preconditioning on coronary blood flow and microcirculation

This study aimed to determine the effect of short-term remote ischemic preconditioning (RIPC) on coronary blood flow and microcirculation function using the quantitative flow ratio (QFR) and index of microcirculatory resistance (IMR). We randomly divided 129 patients undergoing coronary angiography (CAG) into RIPC and control groups. Following the first CAG, we randomly divided the patients further into the unilateral upper limb and lower limb groups for four cycles of ischemia/reperfusion circulation; subsequently, we performed the second CAG. During each CAG, contrast-flow QFR (cQFR), fixed-flow QFR (fQFR), and IMR (in patients with cardiac syndrome X) were calculated and compared. We measured 253 coronary arteries in 129 patients. Compared to the control group, the average cQFR of the RIPC group increased significantly after RIPC. Additionally, 23 patients with cardiac syndrome X (IMR > 30) were included in this study. Compared to the control group, IMR and the difference between cQFR and fQFR (cQFR-fQFR) both decreased significantly after receiving RIPC. The application of RIPC can increase coronary blood flow and improve coronary microcirculation function.

Kainic Acid-Induced Excitotoxicity Leads to the Activation of Heat Shock Response.

Heat shock response (HSR) which is regulated by heat shock factor 1 (HSF1) is the most important mechanism and the major regulator that prevents protein aggregation in neurodegenerative diseases. Excitotoxicity, which is the accumulation of excess glutamate in synaptic cleft, is observed in age-dependent neurodegenerative diseases and also in stroke, epilepsy, and brain trauma. Only a few studies in the literature show the link between excitotoxicity and HSR. In this study, we aimed to show the molecular mechanism underlying this link. We applied heat shock (HS) treatment and induced excitotoxicity with kainic acid (KA) in neuroblastoma (SHSY-5Y) and glia (immortalized human astrocytes (IHA)) cells. We observed that, only in SHSY-5Y cells, heat shock preconditioning increases cell survival after KA treatment. GLT-1 mRNA expression is increased as a result of KA treatment and HS due to the elevation of HSF1 binding to GLT-1 promoter which was induced by HSF1 phosphorylation and sumolation in SHSY-5Y cells. Additionally, glutamine synthetase and glutaminase expressions are increased after HS preconditioning in SHSY-5Y cells indicating that HS activates glutamate metabolism modulators and accelerates the glutamate cycle. In glia cells, we did not observe the effect of HS preconditioning. In summary, heat shock preconditioning might be protective against excitotoxicity-related cell death and degeneration.

Exercise-induced myocardial hypertrophy preconditioning promotes fibroblast senescence and improves myocardial fibrosis through Nrf2 signaling pathway

ABSTRACT This study aims to investigate how exercise-induced myocardial hypertrophy preconditioning affects cardiac fibroblasts in the context of myocardial fibrosis, a chronic disease that can cause cardiac arrhythmia and heart failure. Heart failure was induced in male C57BL/6 mice via Transverse aortic constriction, and some mice were given swimming exercise before surgery to test the effects of exercise-induced myocardial hypertrophy preconditioning on myocardial fibrosis. Myocardial tissue was evaluated for fibrosis, senescent cells, and apoptotic cells. Myocardial fibroblasts from rats were cultured and treated with norepinephrine to induce fibrosis which were then treated with si-Nrf2 and analyzed for markers of fibrosis, senescence, apoptosis, and cell proliferation. Exercise-induced myocardial hypertrophy preconditioning reduced myocardial fibrosis in mice, as shown by decreased mRNA expression levels of fibrosis-related indicators and increased cell senescence. In vitro data indicated that norepinephrine (NE) treatment increased fibrosis-related markers and reduced apoptotic and senescent cells, and this effect was reversed by pre-conditioning in PRE+NE group. Preconditioning activated Nrf2 and downstream signaling genes, promoting premature senescence in cardiac fibroblasts and tissues isolated from preconditioned mice. Moreover, Nrf2 knockdown reversed proapoptotic effects, restored cell proliferation, reduced senescence-related protein expression, and increased oxidative stress markers and fibrosis-related genes, indicating Nrf2‘s crucial role in regulating oxidative stress response of cardiac fibroblasts. Exercise-induced myocardial hypertrophy preconditioning improves myocardial fibrosis which is Nrf2-dependent, indicating the protective effect of hypertrophy preconditioning. These findings may contribute to the development of therapeutic interventions to prevent or treat myocardial fibrosis.

Effect of Remote Ischemic Preconditioning on Patient Survival and End Organ Injury During Elective Open Abdominal Aortic Surgery Repair: A Randomized Controlled Trial

Effect of Remote Ischemic Preconditioning on Patient Survival and End Organ Injury During Elective Open Abdominal Aortic Surgery Repair: A Randomized Controlled Trial

The preconditioning effect of different exercise training modes on middle cerebral artery occlusion induced-behavioral deficit in senescent rats

IntroductionBrain abilities decrease after brain stroke in elderly. The neuroprotective effect of exercise training has been proved in clinical trials and animal experiment. Nevertheless, it is not still clear what kind of exercise has greater protective effect. The present study aimed at investigating pre-conditioning effect of endurance, resistance, and concurrent training on learning ability, anxiety, and spatial memory in aged rats following stroke strength with middle cerebral artery occlusion. MethodWe used 50 male Wistar rats (age = 24 months) that were assigned randomly in five groups; 1: sham group, 2: Control group 3: Endurance training 4: Resistance training, and 5: concurrent training. The exercise training groups received training for four weeks. Following training, middle cerebral artery occlusion was applied to induce cerebral ischemia. Using the elevated plus maze, shuttle box test, and Morris water maze, neurocognitive functions were tested in the sample rats. ResultsIt was found that resistance training did not affect spatial memory in the acquisition phase, while concurrent training and endurance training enhanced spatial memory in the acquisition phase. On the contrary, spatial memory was improved by resistance training in the retention phase, while concurrent and endurance exercises did not affect spatial memory in the retention phase. Passive avoidance learning ability at acquisition phase was more in resistance group compared to the endurance and concurrent training in shuttle box test, but in retention phase was similar between training groups. Unlike endurance and concurrent training, resistance training reduced anxiety in senescent rats. ConclusionAll three exercise types alleviated aversive learning and memory impairment induced by stroke in senescent rats. Notably, the resistance training showed a greater protective effect compared to the other two training methods.

건강한 대상자에게 허혈성 전처치와 햄스트링 스트레칭, 복합적용이 운동능력에 미치는 즉각적인 효과비교

Purpose: This study aimed to examine the effects of ischemic preconditioning (IPC), hamstring stretching, and complex approach on exercise ability and to identify the impact on the ability to recover after exercise. Methods: A total of 20 healthy adult males were included in this study. All subjects performed different interventions before exercise (nothing applied [CON], IPC, hamstring stretching, and IPC + hamstring stretching [Complex]), followed by cycling exercise, with a 5-min rest after exercise. Heart rate (HR), rate of perceived exertion (RPE), and oxygen saturation (Spo2) were measured during exercise and 5 min after exercise. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) was measured before exercise, immediately after exercise, and 5 min after exercise. Data analysis was performed using one-way repeated measures analysis of variance. Results: Exercise time was significantly different between Complex and CON and IPC conditions. RPE measured during exercise was significantly different between Complex and CON and IPC conditions. A significant difference in HR measured during exercise was observed between Complex and CON conditions. However, no significant difference in SBP, DBP, HR, Spo2, and RPE measured 5 min after exercise was observed between the conditions. Conclusion: Applying IPC and hamstring stretching together before exercise can be a particularly effective method for improving aerobic exercise capacity.

Effect of Ischemic Preconditioning (IPC) on Recovery of Exercise Performance Following a Bout of Exercise to Volitional Exhaustion

The purpose of the present study was to investigate the effect of ischemic preconditioning (IPC) on the recovery of exercise performance following maximal, incremental exercise. A total of 13 healthy males volunteered to participate, undertaking three experimental trials involving a constant work-rate bout of severe intensity exercise undertaken to the limit of tolerance that was preceded by a 40-min recovery period consequent to a maximal, incremental exercise test. During the recovery period, participants underwent IPC at 220 mmHg, sham IPC (SHAM; 20 mmHg), and passive rest (CON). Exercise tolerance time was higher following IPC as compared to SHAM and CON {199 ± 36 (CON) vs. 203 ± 35 (SHAM) vs. 219 ± 34 (IPC), p = 0.03}. This effect was accompanied by a tendency toward an augmented increase in blood lactate from rest to exercise in IPC compared to SHAM and CON (p = 0.08). There was no effect of IPC on oxygen uptake kinetics or muscle oxygenation as indicated via near-infrared spectroscopy. IPC may therefore have the capacity to augment recovery from prior maximal exercise, but this does not appear to be due to enhancements to oxygen uptake kinetics or muscle oxygenation.

Effects of Exercise Preconditioning on Doxorubicin-Induced Liver and Kidney Toxicity in Male and Female Rats.

Doxorubicin (DOX) is a highly effective chemotherapy agent prescribed for cancer treatment. However, the clinical use of DOX is limited due to off-target toxicity in healthy tissues. In this regard, hepatic and renal metabolic clearance results in DOX accumulation within these organ systems. Within the liver and kidneys, DOX causes inflammation and oxidative stress, which promotes cytotoxic cellular signaling. While there is currently no standard of care to treat DOX hepatic- and nephrotoxicity, endurance exercise preconditioning may be an effective intervention to prevent elevations in liver alanine transaminase (ALT) and aspartate aminotransferase (AST) and to improve kidney creatinine clearance. To determine whether exercise preconditioning is sufficient to reduce liver and kidney toxicity resulting from acute exposure to DOX chemotherapy treatment, male and female Sprague-Dawley rats remained sedentary or were exercise trained prior to saline or DOX exposure. Our findings demonstrate that DOX treatment elevated AST and AST/ALT in male rats, with no effects of exercise preconditioning to prevent these increases. We also showed increased plasma markers of renin-angiotensin-aldosterone system (RAAS) activation and urine markers of proteinuria and proximal tubule damage, with male rats revealing greater differences compared to females. Exercise preconditioning showed improved urine creatinine clearance and reduced cystatin c in males, while females had reduced plasma angiotensin II (AngII) levels. Our results demonstrate both tissue- and sex-specific responses related to the effects of exercise preconditioning and DOX treatment on markers of liver and kidney toxicity.

Thermal preconditioning can reduce the incidence of intraoperatively acquired pressure injuries

Intraoperatively acquired pressure injuries (IAPIs) occur frequently among patients who undergo surgical procedures that last longer than 3 h. Several studies indicated that heat shock proteins (HSPs) play an important role in the protection of stress-induced damages in skin tissues. Hence, the aim of this study was to investigate the potential preventive effect of thermal preconditioning (TPC) on IAPIs in surgical patients and rats and to identify the differentially expressed HSP genes in response to the above treatment. TPC was performed on one group of hairless rats before the model of pressure injuries was established. Subsequently, the size of skin lesions was measured and the expression levels of mRNA and protein of HSPs of the pressured skin were detected by real-time polymerase chain reaction (RT-PCR), western blot, and immunohistochemical staining. For human studies, 118 surgical patients were randomly divided into the TPC group (n = 59) and the control group (n = 59), respectively. The temperature and pressure of sacral skin, as well as the incidence of pressure injury (PI) were detected and compared. In animal studies, TPC significantly reduced both the size and incidence of PI in rats on the second, third and fourth days post treatment. In addition, the expression levels of both mRNA and protein of HSP27 were increased in the TPC group, compared with the control group. Immunohistochemical staining showed that HSP27 was distributed in various types of dermal cells and increased in basal cells. In human studies, a significant reduction (75%) of IAPIs was observed among the patients in the TPC group. TPC can reduce the incidence of PI in rats and humans, and the upregulation of HSP27 may play an important role in this biological progress. Further studies are warranted to explore the molecular mechanism of the preventive effect in PI mediated by HSP27.

#6287 EFFECT OF REMOTE ISCHEMIC PRECONDITIONING ON NUTRITIONAL STATUS, COGNITIVE FUNCTION, AND BONE IN HEMODIALYSIS PATIENTS: A RANDOMIZED CONTROLLED TRIAL

Abstract Background and Aims Remote ischemic preconditioning (RIPC) is a process in which a brief period of ischemia is induced in one part of the body to protect another part from damage due to subsequent periods of more severe ischemia. Hemodialysis sessions are considered an ischemic process because it involves reducing blood flow to certain parts of the body, which can lead to tissue damage .Malnutrition, deterioration of cognitive function, bone disorders, cardiovascular disease, and hemodynamic instability can result from ischemia induced by hemodialysis sessions. These adverse effects increase mortality in HD patients. RIPC has been studied as a potential therapeutic strategy to reduce the risk of cardiovascular events in hemodialysis patients; however, the effect of RIPC on cognitive function, nutritional status, and bone disorder among hemodialysis patients has not been enough studied. Aim: to assess the effect of remote ischemic preconditioning on nutritional status, bone disorders, and cognitive function in hemodialysis patients at the urology and nephrology center, Mansoura University. Method Fifty patients who received regular hemodialysis for more than one year in our dialysis unit were included. The patients were randomized (single-blind) into two groups a control group (20 patients) and an intervention group (30 patients). Before each HD session, sphygmomanometer cuffs was placed around the non-vascular access arm. Three cycles of ischemia for five minutes were performed followed by reperfusion for five minutes. Ischemia was induced by inflating the sphygmomanometer cuffs to 200 mmHg. This maneuver was done before each HD session for 12 weeks. The Montreal Cognitive Assessment (MOCA) was used to assess cognitive function. The nutritional state was assessed by anthropometric measurement (body weight, BMI), laboratory (serum albumin and serum cholesterol), and Subjective Global Assessment Form (SGA). Serum calcium (s.Ca) and serum phosphorus (s.po), serum alkaline phosphate (s. ALP) and intact parathyroid hormone (iPTH) were used as indices for bone profile. Results The intervention group include 30 patient with mean age (36+/-10), 19 male (63.3%) and 11 females (36.7%). The control group include 20 patient with mean age (46+/-9), 12 male (60%) and eight female (40%). None of these patients’ demographic data (age, sex, original kidney disease, and duration of dialysis) were significantly different between the study groups (P&amp;gt;0.05). MOCA test score at baseline was (24.5 +/-2.6) at intervention group and (24.4+/-3.2) at control group, and after 12 weeks intervention was (24.8 +/-2.2) at intervention group and (24.4+/-2.8) at control group. there were no statistical significance regarding cognitive function between the two group over time (p = 0.4). NO significant Statistical changes in anthropometric measurements (Body weight (p = 0.3) and BMI (P = 0.6) were found between the two groups. Additionally, no significant changes (serum albumin and cholesterol) were detected. SGA score at baseline was at intervention group (1.2+/-0.4) and control group (1.1 +/- 0.3), and after 12 week was at the intervention group (1.4 +/-0.5) and control group (1.6 +/-0.5). SGA showed no statistical significance between the two groups over time (p = 0.2). No significant statistical changes regarding bone profile (s.ca (p = 0.5), s.PO (p = 0.2), s.ALP (p = 0.7) and iPTH (p = 0.5)). Conclusion Although some studies showed a beneficial effect of RIBC on reduction of cardiovascular risk, our study found no significant effect on cognitive function, nutritional status, and bone disorders among hemodialysis patients.

Cardioprotective Effects of Dexmedetomidine in an Oxidative-Stress In Vitro Model of Neonatal Rat Cardiomyocytes.

Preterm birth is a risk factor for cardiometabolic disease. The preterm heart before terminal differentiation is in a phase that is crucial for the number and structure of cardiomyocytes in further development, with adverse effects of hypoxic and hyperoxic events. Pharmacological intervention could attenuate the negative effects of oxygen. Dexmedetomidine (DEX) is an α2-adrenoceptor agonist and has been mentioned in connection with cardio-protective benefits. In this study, H9c2 myocytes and primary fetal rat cardiomyocytes (NRCM) were cultured for 24 h under hypoxic condition (5% O2), corresponding to fetal physioxia (pO2 32-45 mmHg), ambient oxygen (21% O2, pO2 ~150 mmHg), or hyperoxic conditions (80% O2, pO2 ~300 mmHg). Subsequently, the effects of DEX preconditioning (0.1 µM, 1 µM, 10 µM) were analyzed. Modulated oxygen tension reduced both proliferating cardiomyocytes and transcripts (CycD2). High-oxygen tension induced hypertrophy in H9c2 cells. Cell-death-associated transcripts for caspase-dependent apoptosis (Casp3/8) increased, whereas caspase-independent transcripts (AIF) increased in H9c2 cells and decreased in NRCMs. Autophagy-related mediators (Atg5/12) were induced in H9c2 under both oxygen conditions, whereas they were downregulated in NRCMs. DEX preconditioning protected H9c2 and NRCMs from oxidative stress through inhibition of transcription of the oxidative stress marker GCLC, and inhibited the transcription of both the redox-sensitive transcription factors Nrf2 under hyperoxia and Hif1α under hypoxia. In addition, DEX normalized the gene expression of Hippo-pathway mediators (YAP1, Tead1, Lats2, Cul7) that exhibited abnormalities due to differential oxygen tensions compared with normoxia, suggesting that DEX modulates the activation of the Hippo pathway. This, in the context of the protective impact of redox-sensitive factors, may provide a possible rationale for the cardio-protective effects of DEX in oxygen-modulated requirements on survival-promoting transcripts of immortalized and fetal cardiomyocytes.

Effects of remote ischaemic preconditioning on myocardial injury after major abdominal surgery in patients at high risk for cardiovascular adverse events in China (RIPC-MAS): protocol for a randomised, sham-controlled, observer-blinded trial

IntroductionMyocardial injury after non-cardiac surgery (MINS) caused by an ischaemic mechanism is common and is associated with adverse short-term and long-term prognoses. However, MINS is a recent concept, and few...

Impacts of ischemic preconditioning in liver resection: systematic review with meta-analysis.

To assess the beneficial effects of ischemic preconditioning (IPC) in liver resection and evaluate its applicability in clinical practice. Liver surgeries are usually associated with intentional transient ischemia for hemostatic control. IPC is a surgical step that intends to reduce the effects of ischemia/reperfusion; however, there is no strong evidence about the real impact of the IPC, and it is necessary to effectively clarify what its effects are. Randomized clinical trials were selected comparing IPC with no preconditioning in patients undergoing liver resection. Data were extracted by three independent researchers according to the PRISMA guidelines, Supplemental Digital Content 1, http://links.lww.com/JS9/A79. Several outcomes were evaluated, including postoperative peaks of transaminases and bilirubin, mortality, length of hospital stay, length of stay in the ICU, bleeding, transfusion of blood products, among others. Bias risks were assessed using the Cochrane collaboration tool. 17 articles were selected, with a total of 1,052 patients. IPC did not change the surgical time of the liver resections while these patients bled less (MD: -49.97mL, 95% CI, -86.32 to -13.6, I²: 64%), needed less blood products (RR: 0.71, 95% CI, 0.53 to 0.96; I²=0%), and had a lower risk of postoperative ascites (RR 0.40, 95% CI, 0.17 to 0.93; I²=0%). The other outcomes had no statistical differences or could not have their meta-analyses conducted due to high heterogeneity. IPC is applicable in clinical practice and it has some beneficial effect. However, there is not enough evidence to encourage its routine use.

Age-Dependent Effects of Remote Preconditioning in Hypertensive Rat Hearts are Associated With Activation of RISK Signaling.

Remote ischemic preconditioning (RIPC) represents one of the forms of innate cardioprotection. While being effective in animal models, its application in humans has not been always beneficial, which might be attributed to the presence of various comorbidities, such as hypertension, or being related to the confounding factors, such as patients' sex and age. RIPC has been shown to mediate its cardioprotective effects through the activation of Reperfusion Injury Salvage Kinase (RISK) pathway in healthy animals, however, scarce evidence supports this effect of RIPC in the hearts of spontaneously hypertensive (SHR) rats, in particular, in relationship with aging. The study aimed to investigate the effectiveness of RIPC in male SHR rats of different age and to evaluate the role of RISK pathway in the effect of RIPC on cardiac ischemic tolerance. RIPC was performed using three cycles of inflation/deflation of the pressure cuff placed on the hind limb of anesthetized rats aged three, five and eight months. Subsequently, hearts were excised, Langendorff-perfused and exposed to 30-min global ischemia and 2-h reperfusion. Infarct-sparing and antiarrhythmic effects of RIPC were observed only in three and five months-old animals but not in eight months-old rats. Beneficial effects of RIPC were associated with increased activity of RISK and decreased apoptotic signaling only in three and five months-old animals. In conclusion, RIPC showed cardioprotective effects in SHR rats that were partially age-dependent and might be attributed to the differences in the activation of RISK pathway and various aspects of ischemia/reperfusion injury in aging animals.

Clinical effects of ischemic preconditioning in polyneuropathy of various origins

Introduction. Polyneuropathies are widespread among the population. Diabetes mellitus and industrial vibration are common causes of polyneuropathy, having common links of pathogenesis involving the autonomic nervous system. The therapeutic effects of ischemic preconditioning are realized by influencing pathogenetic mechanisms, and therefore their study in polyneuropathies of various genesis is of scientific interest.&#x0D; The aim of the study was to investigate the remote clinical effects of ischemic preconditioning in polyneuropathies of various genesis.&#x0D; Materials and methods. Twenty-five patients divided into 2 groups with lower extremity polyneuropathy of vibration and diabetic genesis were examined. &#x0D; A clinical and electroneuromyographic study of the peripheral nerves of the lower extremities was performed. An analysis of heart rate variability before and after the treatment with ischemic preconditioning of the upper extremities was executed.&#x0D; Results. In both groups of the patients with polyneuropathy a decrease in clinical manifestations in the form of pain syndrome and sensitive disorders (numbness and paresthesia), an improvement in vibration sensitivity, an increase in impulse conduction velocity, mainly along the peripheral sensory nerve fibers were revealed. The analysis of heart rate variability after performing of ischemic preconditioning showed a gaining of the power of very low frequency oscillations, which indicated to an increase in the compensatory capabilities of autonomic regulation.&#x0D; Limitations. The investigation was limited by studying the clinical and electrophysiological characteristics of the peripheral nervous system in 25 patients with diabetes mellitus type 2 and vibration disease caused by the exposure to local and whole-body vibration.&#x0D; Conclusion. After the course of treatment of the pain syndrome, sensitive and autonomic disorders decrease with an increase in the compensatory possibilities of autonomic regulation, the functions of conducting along sensory nerves improve. Positive distant effects of ischemic preconditioning in the correction of manifestations of vibration and diabetic polyneuropathies indicate to a systemic effect on the mechanisms of autonomic regulation. The distance is manifested in the remoteness of the appearance of effects from the place of application of the technique.

Effects of remote ischemic preconditioning on renal protection in patients undergoing robot-assisted laparoscopic partial nephrectomy.

We aimed to evaluate the renoprotective effects of remote ischemic preconditioning (RIPC) in patients undergoing robot-assisted laparoscopic partial nephrectomy (RAPN). Data from 59 patients with solitary renal tumors who underwent RAPN with RIPC comprising three cycles of 5-min inflation to 200mmHg of a blood pressure cuff applied to one lower limb followed by 5-min reperfusion by cuff deflation, from 2018 to 2020 were analyzed. Patients who underwent RAPN for solitary renal tumors without RIPC between 2018 and 2020 were selected as controls. The postoperative estimated glomerular filtration rate (eGFR) at the nadir during hospitalization and the percentage change from baseline were compared using propensity score matching analysis. We performed a sensitivity analysis with imputations for missing postoperative renal function data weighted by the inverse probability of the data being observed. Of the 59 patients with RIPC and 482 patients without RIPC, 53 each were matched based on propensity scores. No significant differences in the postoperative eGFR in mL/min/1.73 m2 at nadir (mean difference 3.8; 95% confidence interval [CI] -2.8 to 10.4) and its percentage change from baseline (mean difference 4.7; 95% CI -1.6 to 11.1) were observed between the two groups. Sensitivity analysis also indicated no significant differences. No complications were associated with the RIPC. In conclusion, we found no significant evidence of the protective effect of RIPC against renal dysfunction after RAPN. Further research is required to determine whether specific patient subgroups benefit from RIPC.Trial registration number: UMIN000030305 (December 8, 2017).

The role of preconditioning for extreme storm surges in the western Baltic Sea

Abstract. When natural hazards interact in compound events, they may reinforce each other. This is a concern today and in light of climate change. In the case of coastal flooding, sea-level variability due to tides, seasonal to inter-annual salinity and temperature variations, or larger–scale wind conditions modify the development and ramifications of extreme sea levels. Here, we explore how various prior conditions could have influenced peak water levels for the devastating coastal flooding event in the western Baltic Sea in 1872. We design numerical experiments by imposing a range of precondition circumstances as boundary conditions to numerical ocean model simulations. This allows us to quantify the changes in peak water levels that arise due to alternative preconditioning of the sea level before the storm surge. Our results show that certain preconditioning could have generated even more catastrophic impacts. As an example, a simulated increase in the water level of 36 cm compared to the 1872 event occurred in Køge just south of Copenhagen (Denmark) and surrounding areas – a region that was already severely impacted. The increased water levels caused by the alternative sea-level patterns propagate as long waves until encountering shallow and narrow straits, and after that, the effect vastly decreases. Adding artificial increases in wind speeds to each study point location reveals a near-linear relationship with peak water levels for all western Baltic locations, highlighting the need for good assessments of future wind extremes. Our research indicates that a more hybrid approach to analysing compound events and readjusting our present warning system to a more contextualised framework might provide a firmer foundation for climate adaptation and disaster risk management. In particular, accentuating the importance of compound preconditioning effects on the outcome of natural hazards may avoid under- or overestimation of the associated risks.