Min Of Occlusion Research Articles

Inhibition of Ferroptosis Using UAMC‐3203 in the Post‐stroke Period Does Not Impact Cognitive Outcomes in Diabetic Rats

IntroductionPost‐stroke cognitive impairment (PSCI) contributes to significant long‐term disability in stroke victims. 30% of ischemic stroke victims in the United States also have diabetes, which increases the risk of hemorrhagic transformation as well as PSCI. Ferroptosis, an iron‐induced cell death can instigate increased oxidative stress and contribute to impaired neurovascular repair leading to PSCI in diabetes. In our previous studies, we were able to identify that treating diabetic animals with an iron chelator, deferoxamine (DFX), prevents post‐stroke vasoregression and improves functional outcomes. Furthermore, DFX prevented the activation of ferroptosis in brain microvascular endothelial cells in vitro. Untreated diabetic animals experienced progressive cognitive decline while being monitored for 8 weeks. These findings led us to speculate that endothelial ferroptosis also plays a role in vasoregression and impacts cognitive outcomes post‐stroke. Therefore, this study was designed to test the hypothesis that inhibiting ferroptosis in the post‐stroke period will improve cognitive recovery in diabetic animals.MethodsAnimals were housed in reverse light cycle. 8 weeks after diabetes onset, male rats underwent 60 min middle cerebral artery occlusion (MCAO). On Day 3, after stroke injury was confirmed by MRI, animals were randomized to UAMC‐3 (2mg/kg) or vehicle treatment for 2 weeks. Sensorimotor and cognitive behavioral tests were performed during the animals’ active hours up to 8 weeks post MCAO.Results(Table 1): 60 min occlusion caused significant acute neurological deficits. There were no differences between the groups in indices measured by novel object recognition (NOR), Y‐maze and sucrose preference tests. Interestingly, step through latency in passive avoidance test (PAT) was lower in the UAMC‐3203 group.ConclusionTreatment with a ferroptosis inhibitor for 2 weeks after stroke did not impact recognition and working memory but worsened aversive learning in diabetic male rats. Unlike our previous study in which behavior tests were performed during rats’ passive hours, there was no progressive cognitive decline in untreated animals. Further evaluation of behavior testing times as well as tissue markers of neurovascular degeneration, inflammation and ferroptosis are required to determine whether molecular and cellular markers are affected by the treatment before overt changes in behavioral outcomes.

Effects of Electrical Spinal Cord Stimulation on the Activity of the Hypothalamic‐Pituitary‐Adrenocortical System and the Sensitivity of the Gastric Mucosa to Ulcerogenic Stimuli

Our previous results of two areas of unrelated researches are the basis of the present study. We demonstrated previously that the hypothalamic‐pituitary‐adrenocortical (HPA) axis is gastroprotective component of the brain‐gut axis and stress‐induced glucocorticoids are gastroprotective hormones but not ulcerogenic ones (Filaretova et al., 2016). At the same time recently electrical spinal cord stimulation began to be used for both experimental studies of motor functions regulation and rehabilitation of motor functions in patients with spinal cord injury (Gerasimenko et al., 2021; Moshonkina et al., 2016). The spinal cord stimulation directed to the activation of spinal locomotor related networks affected visceral systems as well. The aim of the present experimental work was to verify whether electrical spinal cord stimulation may activate the HPA axis and affect a sensitivity of the gastric mucosa to ulcerogenic stimuli in rats. Two ulcerogenic stimuli were used in anesthetized rats: 1) prolonged gastric ischemia/reperfusion (I/R, 30 min occlusion of celiac artery followed by 3 h of reperfusion); 2) indomethacin administration (IM, 35 mg/kg, sc). For spinal stimulation, stainless steel wire electrodes (AS632; Cooner Wire, California, USA) were fixed in fasciae between T11‐12 and L1–L2 vertebrae of anesthetized animals. Electrodes for recording motor responses to stimulation placed to the muscles of the hind limbs. A‐M System, Model 2100 stimulator was used for spinal cord stimulation. At the beginning motor thresholds determined by stimulation with monopolar rectangular pulses (1 ms). Then the spinal cord was stimulated with a frequency 30 Hz and a subthreshold current (350–700 μA) in order to exclude the influence of movements for 20 min. Sham‐stimulated (control) rats were subjected to the same manipulations except for the stimulation itself. The concentration of corticosterone in blood plasma was determined using commercial ELISA kits. The spinal cord stimulation resulted in an increase of blood glucocorticoid level 1 h later suggesting an activation of the HPA axis. The spinal stimulation, applied 1 h before the onset of ulcerogenic stimuli, also significantly attenuated gastric erosion formation induced by I/R and IM as well. The data suggest that the electrical spinal cord stimulation may activate the HPA axis and affect a sensitivity of the gastric mucosa to ulcerogenic stimuli in rats producing gastroprotective effect. We consider the results as a basis for further research to verify a possibility of an involvement of glucocorticoids in the mechanisms that may provide the beneficial effects of spinal neuromodulation.

V10-02 ROBOTIC PARTIAL NEPHRECTOMY WITH REVERSIBLE SELECTIVE ARTERY ENDOLUMINAL BALLOON OCCLUSION ON A KIDNEY GRAFT

You have accessJournal of UrologyCME1 May 2022V10-02 ROBOTIC PARTIAL NEPHRECTOMY WITH REVERSIBLE SELECTIVE ARTERY ENDOLUMINAL BALLOON OCCLUSION ON A KIDNEY GRAFT Patrick-Julien Treacy, Severine Lagarde, Al Emadi Ibrahim, Thomas Prudhomme, Marine Lesourd, Rayan Atme, Matthieu Durand, Imad Bentellis, Michel Soulié, and Nicolas Doumerc Patrick-Julien TreacyPatrick-Julien Treacy More articles by this author , Severine LagardeSeverine Lagarde More articles by this author , Al Emadi IbrahimAl Emadi Ibrahim More articles by this author , Thomas PrudhommeThomas Prudhomme More articles by this author , Marine LesourdMarine Lesourd More articles by this author , Rayan AtmeRayan Atme More articles by this author , Matthieu DurandMatthieu Durand More articles by this author , Imad BentellisImad Bentellis More articles by this author , Michel SouliéMichel Soulié More articles by this author , and Nicolas DoumercNicolas Doumerc More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002623.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Small kidney tumors on renal grafts are accessible to partial nephrectomy surgery, but expose to clamping difficulties due to challenging access to graft vessels. Endoluminal balloons provide a reversible alternative to clamping of the graft artery. The objective of this video was to show the safety and efficiency of this technique for robot-assisted partial nephrectomy on kidney graft. METHODS: 69-year-old patient, transplanted in 2012, with extensive cardiovascular history. Discovery on follow-up ultrasound of a 2.5x2.3 cm tumor, confirmed by CT scan. Decision of robot-assisted partial nephrectomy after the multidisciplinary consultation meeting. An endoluminal balloon was placed in the segmental artery vascularizing the tumor after ponction of the femoral artery in interventional radiology. The patient was then installed in a supine position in the operating room for robotic-assisted partial nephrectomy, with trocar positioning similar to pelvic robotic surgery (assistant on the left side of the patient, two assistant trocars in the left iliac fossa and between the optical trocar and arm #1). RESULTS: The operative time in interventional radiology was 25 minutes, performed under local anesthesia. The operative time of the partial nephrectomy was 45 min, with a 10 min occlusion of the segmental artery. Blood loss was 200 cc. The postoperative period was uneventful, with the patient being discharged on day 2 after surgery. The serum creatinine level at discharge was 80 micromol/L, and the 3-month level was similar. Histopathologic analysis confirmed the malignant nature of the tumor, with clear cell renal cell carcinoma classified as pT1a Nx MO, nucleolar grade 3 (WHO 2018), with negative margins. 2 additional patients were performed using this technique, with similar results. CONCLUSIONS: Selective and reversible endoluminal balloon occlusion of segmental arteries appears to be a safe and effective alternative in arterial clamping for robotic-assisted partial nephrectomies on kidney grafts. A larger cohort will allow us to confirm our hypothesis. Source of Funding: none © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e848 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Patrick-Julien Treacy More articles by this author Severine Lagarde More articles by this author Al Emadi Ibrahim More articles by this author Thomas Prudhomme More articles by this author Marine Lesourd More articles by this author Rayan Atme More articles by this author Matthieu Durand More articles by this author Imad Bentellis More articles by this author Michel Soulié More articles by this author Nicolas Doumerc More articles by this author Expand All Advertisement PDF DownloadLoading ...

Nitric oxide synthase inhibitor is an effective therapy for ischemia‐reperfusion injury in mice

BackgroundInhibition of nitric oxide synthase (NOS) has been shown to paradoxically protect against ischemic brain injury by an unknown mechanism. Recently, we found that NOS inhibitor, N (gamma)‐nitro‐L‐arginine methyl ester (L‐NAME), protects primary cultures of endothelial cells and neurons against oxygen‐glucose deprivation‐reoxygenation injury by preventing NOS uncoupling. Thus, the objective of the present study was to demonstrate the effectiveness of locally administered L‐NAME against ischemia‐reperfusion (I‐R) injury.MethodsTransient focal cerebral ischemia in male mice (C57Bl/6, 2‐4 months) was achieved by filament method of MCAO with a 60 min occlusion. We employed a novel approach to inject L‐NAME (1 mg/Kg dosages at a rate of 60 ug/minute) locally into the ischemic zone by threading a catheter up the middle cerebral artery. This was timed to the onset of reperfusion by rapidly followng the removal of the occlusion with the silicon suture. Following 24‐hour reperfusion, infarct size was determined by 2,3,5‐Triphenyltetrazolium chloride (TTC) staining and neurological function was assessed by employing a standard neurological score (0‐4 range) and Rotarod performance test.ResultsAdmnistration of FITC Dextran 40K and fluorescence microscopy of the brain slices 1 hour post‐ischemia confirmed the effective delivery of injected L‐NAME into the ischemic tissue. Localized injection of L‐NAME was protective against I‐R injury and promoted significant recovery of neurological and motor function (Figure).ConclusionLocal NOS inhibition could serve as an adjuvant for reperfusion therapies of ischemic stroke.

Renal Denervation Attenuates Adverse Remodeling and Intramyocardial Inflammation in Acute Myocardial Infarction With Ischemia-Reperfusion Injury.

BackgroundInhibition of sympathetic activity and renin–angiotensin system with renal denervation (RDN) was proved to be effective in managing refractory hypertension, and improving left ventricular (LV) performance in chronic heart failure. The inhibition of sustained sympathetic activation prevents or delays the development of cardiac fibrosis and dysfunction that occurs after myocardial infarction and ischemia–reperfusion (I/R) injury. The translational efficiency of RDN remains to be defined in preclinical animal studies.ObjectivesThis study investigated the therapeutic role of RDN in adverse remodeling and intramyocardial inflammation in myocardial ischemia–reperfusion (MI/R) injury.MethodsHerein, 15 minipigs were subjected to 90-min percutaneous occlusion of the left anterior descending artery followed by reperfusion. Eight animals received simultaneous RDN using catheter-based radiofrequency ablation (MI/R-RDN). Cardiac function and infarct volume were measured in vivo, followed by histological and biochemical analyses.ResultsThe infarct volume in I/R-RDN pigs reduced at 30 days postreperfusion, compared to I/R-Sham animals. The levels of catecholamine and cytokines in the serum, kidney cortex, the border, and infarcted regions of the heart were significantly reduced in I/R-RDN group. Moreover, the gene expression of collagen and the protein expression of adrenergic receptor beta 1 in heart were also decreased in I/R-RDN mice. Additionally, RDN therapy alleviated myocardial oxidative stress.ConclusionRDN is an effective therapeutic strategy for counteracting postreperfusion myocardial injury and dysfunction, and the application of RDN holds promising prospects in clinical practice.

Regional analysis of inflammation and contractile function in reperfused acute myocardial infarction by in vivo 19F cardiovascular magnetic resonance in pigs

Inflammatory cell infiltration is central to healing after acute myocardial infarction (AMI). The relation of regional inflammation to edema, infarct size (IS), microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and regional and global LV function is not clear. Here we noninvasively characterized regional inflammation and contractile function in reperfused AMI in pigs using fluorine (19F) cardiovascular magnetic resonance (CMR). Adult anesthetized pigs underwent left anterior descending coronary artery instrumentation with either 90 min occlusion (n = 17) or without occlusion (sham, n = 5). After 3 days, in surviving animals a perfluorooctyl bromide nanoemulsion was infused intravenously to label monocytes/macrophages. At day 6, in vivo 1H-CMR was performed with cine, T2 and T2* weighted imaging, T2 and T1 mapping, perfusion and late gadolinium enhancement followed by 19F-CMR. Pigs were sacrificed for subsequent ex vivo scans and histology. Edema extent was 35 ± 8% and IS was 22 ± 6% of LV mass. Six of ten surviving AMI animals displayed both MVO and IMH (3.3 ± 1.6% and 1.9 ± 0.8% of LV mass). The 19F signal, reflecting the presence and density of monocytes/macrophages, was consistently smaller than edema volume or IS and not apparent in remote areas. The 19F signal-to-noise ratio (SNR) > 8 in the infarct border zone was associated with impaired remote systolic wall thickening. A whole heart value of 19F integral (19F SNR × milliliter) > 200 was related to initial LV remodeling independently of edema, IS, MVO, and IMH. Thus, 19F-CMR quantitatively characterizes regional inflammation after AMI and its relation to edema, IS, MVO, IMH and regional and global LV function and remodeling.

Chronic myocardial and coronary arterial effects of intracoronary supersaturated oxygen therapy in swine with normal and ischemic-reperfused myocardium

The study assessed chronic myocardial, coronary and systemic effects of intracoronary supersaturated oxygen (SSO2) therapy. Left anterior descending coronary arteries of 40 swine were stented and randomized to 90-min selective intracoronary infusion of SSO2 (pO2 760–1000 mmHg) or normoxemic saline. In 20 out of 40 animals, SSO2 delivery followed a 60-min balloon occlusion to induce myocardial infarction (MI). In both normal and MI models, intracoronary treatment with hyperoxemic SSO2 therapy showed no evidence of coronary thrombosis. There were no biologically relevant differences between treatments at either time point in regard to coronary intervention site healing and neointimal growth. No signs of any myocardial or systemic toxicity were observed after 7 or 30 days. A trend was observed toward reduced incidence of microscopic MI scars and reduced infarct size in histopathology, as well as toward better recovery of echocardiographically evaluated global and regional contractility at 30 days. No treatment related infarcts or thromboemboli were observed in the downstream organs.

Berberine alleviates myocardial ischemia–reperfusion injury by inhibiting inflammatory response and oxidative stress: the key function of miR-26b-5p-mediated PTGS2/MAPK signal transduction

Context Berberine has myocardial protective effects. Objectives The protective effects of berberine on heart ischemia–reperfusion (I/R) injury were explored. Materials and methods Human cardiomyocytes were divided into control group, oxygen-glucose deprivation/re-oxygen (OGD/R) (2 h OGD with 24 h reoxygenation) group, OGD/R + low group (5 μM berberine for 24 h) and OGD/R + high group (10 μM berberine for 24 h). Twenty-four Wistar rats were divided into sham group, I/R group (45 min occlusion with 2 h reperfusion), I/R + berberine group (50 mg/kg berberine 1 h before I/R surgery) and I/R + berberine + antagomir (intraperitoneally injected with miR-26b-5p antagomir). MicroRNA profile, effects of berberine on I/R or OGD/R-induced injuries, and the role of miR-26b-5p in the function of berberine were explored. Results OGD/R treatment suppressed viability (0.41 ± 0.05 vs. 0.87 ± 0.13, p< 0.05), while induced apoptosis (6.6 ± 1.0% vs. 26.3 ± 4.8%, p< 0.05) in cardiomyocytes, which was restored by berberine (viability: 0.64 ± 0.01 for 5 μM and 0.72 ± 0.01 for 10 μM, p< 0.05; apoptosis: 10.9 ± 2.2 for 5 μM and 7.9 ± 1.3 for 10 μM). Berberine induced miR-26b-5p and inhibited PTGS2/MAPK pathway. MiR-26b-5p inhibition counteracted the protective function of berberine. In rats, berberine (50 mg/kg) improved heart histological structure and suppressed inflammatory response, which was impaired by miR-26b-5p inhibition. Discussion and conclusions Berberine exerted anti-I/R function in heart by inducing miR-26b-5p and suppressing the PTGS2/MAPK pathway. These data promote the application of berberine as an anti-I/R agent.

Pretreatment with nicotinamide mononucleotide increases the effect of ischaemic postconditioning on cardioprotection and mitochondrial function following ex vivo myocardial reperfusion injury in aged rats.

The present study aims to evaluate the combined effect of ischaemic postconditioning (IPostC) and nicotinamide mononucleotide (NMN) on cardioprotection and mitochondrial function in aged rats subjected to myocardial ischaemia-reperfusion (IR) injury. Sixty aged Wistar rats were randomly divided into fivegroups (n=12), including sham, control, NMN, IPostC, and NMN+IPostC. Regional ischaemia was induced by 30-min occlusion of the left anterior descending coronary artery (LAD) followed by 60-min reperfusion. IPostC was applied at the onset of reperfusion, by six cycles of 10-s reperfusion/ischaemia. NMN (100mg/kg) was intraperitoneally injected every other day for 28days before IR. Myocardial haemodynamics and infarct size (IS) were measured, and the left ventricles samples were harvested to assess cardiac mitochondrial function. The results showed that all treatments reduced lactate dehydrogenase release compared to those of the control group. IPostC alone failed to reduce IS and myocardial function. However, NMN and combined therapy could significantly improve myocardial function and decrease the IS compared to the control animals. Moreover, the effects of combined therapy on the decrease of IS, mitochondrial reactive oxygen species (ROS), and improvement of mitochondrial membrane potential (MMP) were greater than those of stand-alone treatments. These results demonstrated that cardioprotection by combined therapy with NMN+IPostC was superior to individual treatments, and pretreatment of aged rats with NMN was able to correct the failure of IPostC in protecting the hearts of aged rats against IR injury.

Delayed citalopram administration reduces brain inflammation and enhances skilled motor function after ischaemic stroke in 'MacGreen' mice.

Recent evidence suggests that treatment with antidepressants may promote functional recovery. However, the timeframe in which these pharmacological agents can influence stroke recovery is not well understood. This research investigated whether delayed administration of citalopram, used clinically in the management of post‐stroke depression, could improve long‐term functional recovery following experimental stroke. MacGreen mice carrying an enhanced green fluorescent protein reporter gene in monocyte and macrophage populations were subjected to 45 min occlusion of the middle cerebral artery. Animals were administered citalopram (10 mg/kg/day, n = 20) or saline (n = 20) starting 3 days after stroke for 28 days. Neurological deficits and skilled motor performance in the staircase task were recorded for 9 weeks post stroke. Grey and white matter structural lesions were quantified at Week 9, and enhanced green fluorescent protein immunohistochemistry was used to evaluate the effect of citalopram on inflammation. Twenty‐five animals were included in the final analysis. Citalopram‐treated animals (n = 13) showed a significant increase in impaired forepaw use in the staircase task compared with saline‐treated animals (n = 12) 2, 3 and 7 weeks post stroke but no difference in neurological score at any time point examined. Citalopram treatment was associated with decreased monocyte/macrophage cell density and increased white matter tract integrity within the ipsilateral cortex. In conclusion, delayed administration of citalopram decreased brain inflammation and produced functional gains in our mouse model of stroke. Beneficial effects on skilled motor functions were long‐lasting.

The Role of Carbon Dioxide in the Rat Acute Stroke Penumbra.

PurposeThe vasodilatory response to inhaled CO2 occurs in the acute stroke ischemic penumbra and may be a potential therapeutic modality.MethodsTwenty-two Sprague-Dawley rats were subjected to 90-min occlusion of the M2 segment of the middle cerebral artery (M2CAO) by endovascular technique. The animals were administered different C02 concentrations and scanned serially with 9.4 T MRI. Infarct tissue was determined by diffusion-weighted imaging (DWI) and hypoperfused tissue was determined by arterial spin labeling (PWI).Results4 animals were administered room air (RA)+ 6% CO2 (group 1), 6 animals RA+12% CO2 (Group 2) and 4 animals only RA (group 3). In the rats with CO2 administered (groups 1 and 2), the DWI lesion to cerebral hypoperfusion volume ratio (SD) at pre-CO2 administration, was 0.145(0.168), which increased to 0.708(0.731) during CO2 administration and reduced to 0.533(0.527) post-CO2 administration. In 9 of 10 rats the hypoperfused volume decreased when CO2 was administered. When CO2 was stopped the hypoperfused volume became larger again. Administration of RA+12% CO2 (Group 2) decreased the volume of CBF hypoperfusion significantly compared to the control group (95%CI: 0.084 ± 0.0213, p = 0.004).ConclusionInhaled CO2 appears to reduce the size of the hypoperfused tissue volume during acute stroke and may be a potential modality for treatment of acute ischemic stroke. These findings will nonetheless need to be validated in a larger cohort in other centers.

Abstract WP257: RNS60 Provides Acute And Chronic Protection Of Brain Cells And Function In A Mouse Stroke Model

Introduction: RNS60 is an experimental treatment containing oxygen nanobubbles. RNS60 has previously been shown to reduce neuroinflammation and increase neuronal survival in animal models of multiple sclerosis, amyotrophic lateral sclerosis (ALS), Alzheimer's and Parkinson’s diseases, and traumatic brain injury. RNS60 is in phase 2 clinical testing as a treatment for ALS and acute ischemic stroke. Since RNS60 is protective in a variety of pathophysiological conditions that activate neurodegeneration, we evaluated whether RNS60 can reduce brain injury and rescue cognitive functions in a mouse model of ischemic stroke. Methods: Male C57BL/6J mice (4 months old) were subjected to transient (60 min) occlusion of the middle cerebral artery (tMCAo) followed by reperfusion, or sham surgery. We investigated the effects of post-stroke RNS60 treatment for 3 or 13 days (beginning 1 hour after reperfusion, 0.2 mL administered i.p., 1/day). Two control treatments (normal saline or oxygenated saline without nanobubbles) were used for comparison. Experimenters were blinded to the treatment groups throughout the study. To assess the post-stroke effects of RNS60 treatments, we performed multiple neurobehavioral tests that included modified neurological severity score (mNSS), novel object recognition (NOR), active place avoidance (APA), and the conflict variant of APA. Brains were collected for assessment of infarct volumes or for immunofluorescence measurements of amyloid, neurons, microglia, and axons. Results: Three days of treatment with RNS60 reduced brain infarction, edema, sensory-motor, and cognitive deficits. Thirteen days of treatment reduced brain infarction, amyloid pathology, neuronal cell death, microglial activation, and white matter damage. Noteworthy behavioral effects included recovery of memory during NOR and cognitive flexibility in the APA conflict variant. Conclusion: RNS60 treated mice exhibit significant acute and chronic protection of brain cells and neurobehavior after experimental stroke. Our data support the evaluation of RNS60 in clinical stroke trials.

Abstract WMP91: Angiographic Predictors Of Balloon Test Occlusion Outcomes

Introduction: Balloon test occlusion (BTO) with adjunctive single-photon emission computed tomography (SPECT) has been utilized to predict clinical tolerance after permanent internal carotid artery (ICA) occlusion. Cerebrovascular anatomical characteristics might predict BTO outcomes and identify patients susceptible to test failure. Methods: We performed a single center retrospective study of patients who underwent catheter based cerebral angiogram and ICA BTO from July 2013 to June 2020. SPECT imaging was completed in all the patients who passed the clinical BTO; technetium 99m-ethyl cysteinate dimer was injected intravenously after 15-30 min of occlusion and induced hypotension. The diameter of each of the vessels of the Circle of Willis was measured angiographically. The severity of hypoperfusion on SPECT imaging was classified as none, mild, low intermediate, high intermediate, and severe. Results: A total of 57 patients underwent BTO; neoplasia was the most common indication (n=43, 75%). Twelve patients (21.1%) developed neurologic symptoms and clinically failed the BTO; 45 patients (78.9%) passed and proceeded to SPECT. Contralateral dominant vertebral artery (p=0.02), smaller ACom (p=0.002) and ipsilateral PCom (p=0.03) diameters were correlated with clinical BTO failure. Smaller ACom was most predictive with an AUC of 0.907. The Youden index identified an ACom diameter threshold of 1.1 mm, which demonstrated a sensitivity of 91.7% and specificity of 77.8% (OR 0.026, 95% CI 0.003 - 0.226, ROC=0.847) for the prediction of BTO failure. Patients with severe SPECT asymmetry had significantly smaller caliber ACom arteries (ACom median diameter 0.95 mm vs. rest of cohort median 1.4; p=0.0073). Conclusions: BTO outcomes may be predicted using angiographic findings. A small (&lt;1.1 mm) anterior communicating artery, and, less significantly, a small ipsilateral posterior communicating artery can be used to identify patients who are likely to fail BTO.

Abstract TP248: Nos Inhibitor Is An Effective Adjuvant To Reperfusion Therapy In Ischemic Stroke In Mice

Background: Inhibition nitric oxide synthase (NOS) has been shown to paradoxically protect against ischemic brain injury by an unknown mechanism. Recently, we found that NOS inhibitor, N (gamma)-nitro-L-arginine methyl ester (L-NAME), protects primary cultures of endothelial cells and neurons against oxygen-glucose deprivation-reoxygenation injury by preventing NOS uncoupling. Thus, the objective of the present study was to demonstrate the effectiveness of locally administered L-NAME against ischemia-reperfusion (I-R) injury. Methods: Transient focal cerebral ischemia in male mice (C57Bl/6, 2-4 months) was achieved by filament method of MCAO with a 60 min occlusion. We employed a novel approach to inject L-NAME (1 mg/Kg dosages at a rate of 60 ug/minute) locally into the ischemic zone by threading a catheter up the middle cerebral artery. This was timed to the onset of reperfusion by rapidly followng the removal of the occlusion with silicon suture. Following 24-hour reperfusion, infarct size was determined by 2,3,5-Triphenyltetrazolium chloride (TTC) staining and neurological functioning was recorded employing standard neurological score (0-4 range) and Rotarod performance test. Results: Admnistration of FITC Dextran 40K and fluroscence microscopy of the brain slices 1 hour post-ischemia confirmed the effective delivery of injected L-NAME into ischemic tissue. Localized injection of L-NAME was protective against I-R injury and promoted significant recovery of neurological and motor function (Figure). Conclusion: NOS inhibition could serve as an adjuvant for reperfusion therapies of ischemic stroke.

Involvement of Estrogen Receptor and Mitochondrial KATP Channels in Cardioprotective Effect of Remote Aortic Preconditioning in Isolated Rat Heart

The present study was designed to investigate the role of estrogen receptor and KATP channel in cardioprotective effect of remote aortic preconditioning in rat heart. Remote preconditioning is a phenomenon in which brief episodes of ischemia and reperfusion to remote organs protect the target organ against sustained ischemia/ reperfusion induced injury. Protective effects of remote aortic preconditioning are well established in the heart, but their mechanisms still remain to be elucidated. Remote aortic preconditioning in rats was produced by introducing four episodes of ischemia and reperfusion, each comprising of 5 min occlusion and 5 min reperfusion, through abdominal aorta. Perfused rat heart was isolated and subjected to global ischemia for 30 min followed by reperfusion for 120 min. The degree of cardiac injury was assessed by analysing the level of lactate dehydrogenase, creatin kinase, reactive oxygen species and nitrite in coronary effluent. Myocardial infarct size was also estimated macroscopically using tetrazolium tri chloride staining. Ethylinestradiol (10 μg/kg, orally) as estrogen receptor agonist was noted to reproduce remote aortic preconditioning mediated cardioprotection in ovariectomized rat. However, administration of glibenclamide along with or prior to ethylinestradiol abolished cardioprotection. Moreover, glibenclamide a KATP channel blocker, abolish cardioprotective effect of remote aortic preconditioning with daidzein a caveolin inhibitor (0.2 mg/kg subcutaneous). Ethylinestradiol significantly increased the release of nitric oxide and restored the attenuated cardioprotective effect of remote aortic preconditioning. These data provide the evidence that estrogen receptor activation involved in cardioprotective effect of remote aortic preconditioning-mediated trough opening of KATP channels.

Impact of Acute Ischemia-Reperfusion Injury on Left Ventricular Pressure-Volume Relations in Dogs

Objective: Ischemic conditioning (IC) limits myocyte necrosis after acute myocardial ischemia-reperfusion; however, controversy persists regarding its potential to attenuate LV contractile dysfunction. Pressure-volume (P-V) loop analysis, via the load-insensitive conductance catheter method, was used to evaluate LV contractility, diastolic function, and ventriculo-arterial coupling. The goal of this study was to evaluate the ability of IC to improve post-ischemic recovery of LV contractile function. Methods: Twelve anesthetized dogs were randomly distributed to either the IC or the non-IC group; all dogs were subject to 60-min acute coronary occlusion followed by 180-min reperfusion. IC consisted of 4 repeated cycles of 5-min occlusion and 5-min reperfusion of the left main coronary artery. LV P-V relations were constructed under steady-state conditions (by inferior vena cava occlusion) at the beginning and end of the experiments; P-V loops were acquired at different time points before and during ischemia-reperfusion. Results: During ischemia and reperfusion, dP/dtmax decreased significantly compared to baseline in both groups; dP/dtmin, an indicator of the rate of LV relaxation rate was not affected for either group. Significant changes in several parameters of LV function including LVEF, SW, tPFR, ESV, and EDV caused by ischemia were also identified; none of these negative effects were resorbed, even in part, during reperfusion. Conclusions: Diminished LV contractile efficiency during systole and diastole produced by ischemia-reperfusion did not improve with IC pre-treatment despite significant endogenous protection against tissue necrosis.

Contribution of Myocyte Apoptosis to Myocardial Injury in an &amp;lt;i&amp;gt;in Vivo&amp;lt;/i&amp;gt; Rabbit Preparation of Ischemia-Reperfusion

Objective: Exposure of the heart to repeated, brief episodes of coronary occlusion/reperfusion prevents lethal myocyte injury. Necrosis and apoptosis, two seemingly distinct mechanisms of cell death caused by ischemia could contribute independently to progressive loss of myocardium. Studies suggest that ischemic conditioning (IC) lessens myocyte injury by decreasing apoptosis. The goal of this study was to examine cell death in rabbit hearts subject to ischemia-reperfusion injury without (nIC) or with pretreatment by IC. Methods: In the control study, anesthetized, male rabbits (n = 4/group) underwent 30-min regional coronary occlusion (CO) and either 3, 6 or 24h reperfusion (REP). In the IC study, rabbits were pretreated by IC (2 cycles of 5-min CO and 10-min REP) before 30-min CO and subsequent REP. Additional groups were evaluated with 60, or 120-min CO followed by up to 96 h REP. Agarose electrophoresis was used to detect DNA laddering and poly (ADP-ribose) polymerase (PARP; chromatin bound nuclear DNA repair enzyme) was assessed in myocardial biopsies. Results: Genomic DNA from nIC and IC hearts showed no oligonucleosomal fragmentation. In addition, we did not detect any cleavage of PARP; however, myocardial PARP levels decreased when CO and REP durations were prolonged. Conclusion:Absence of genomic DNA fragmentation or PARP cleavage in an in vivo preparation of ischemia-reperfusion injury does not support the view that apoptosis contributes markedly to post-ischemic tissue necrosis.

Phosphodiesterase 10A Is a Critical Target for Neuroprotection in a Mouse Model of Ischemic Stroke.

Phosphodiesterase 10A (PDE10A) hydrolyzes adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP). It is highly expressed in the striatum. Recent evidence implied that PDE10A may be involved in the inflammatory processes following injury, such as ischemic stroke. Its role in ischemic injury was unknown. Herein, we exposed mice to 90 or 30-min middle cerebral artery occlusion, followed by the delivery of the highly selective PDE10A inhibitor TAK-063 (0.3mg/kg or 3mg/kg) immediately after reperfusion. Animals were sacrificed after 24 or 72h, respectively. Both TAK-063 doses enhanced neurological function, reduced infarct volume, increased neuronal survival, reduced brain edema, and increased blood-brain barrier integrity, alongside cerebral microcirculation improvements. Post-ischemic neuroprotection was associated with increased phosphorylation (i.e., activation) of pro-survival Akt, Erk-1/2, GSK-3α/βand anti-apoptotic Bcl-xL abundance, decreased phosphorylation of pro-survival mTOR, and HIF-1α, MMP-9 and pro-apoptotic Bax abundance. Interestingly, PDE10A inhibition reduced inflammatory cytokines/chemokines, including IFN-γ and TNF-α, analyzed by planar surface immunoassay. In addition, liquid chromatography-tandem mass spectrometry revealed 40 proteins were significantly altered by TAK-063. Our study established PDE10A as a target for ischemic stroke therapy.

Relation between the Severity of the Sensorimotor Cortical Edema with Cell Swelling and the Duration of Common Carotid Artery Occlusion in Rats (Morphometric Study)

The aim of the study. To examine the changes in structure and morphometry in sensorimotor cortical edema with cell swelling in mature white rats after common carotid artery occlusion of various durations.Material and methods. Acute ischemia was modeled on white adult Wistar rats by 20-, 30- and 40-min occlusion of the common carotid arteries (CCA). Histological (hematoxylin-eosin and Nissl staining), immunohistochemical (NSE, MAP-2, GFAP) and morphometric methods were used. Morphometry was assessed on hematoxylin and eosin-stained specimens using ImageJ 1.53 plug-ins (Find Maxima, Find Foci). Statistical hypothesis testing (nonparametric criteria) was performed using Statistica 8.0 software.Results. In the sensorimotor cortex (SMC) of white rats after 20, 30 and 40 minutes of CCA occlusion the signs of cytotoxic brain edema appeared, focal destructive and adaptive changes of neurons and astroglia evolved. The edema persisted throughout the observation period (7 days). The increase in the relative area, the number of cell swelling zones and their hydration (pixel brightness) was significant. On days 1 and 3 after CCA occlusion, some of the SMC astrocyte processes underwent destruction. Subpial and perivascular zones suffered to a greater extent. Mild and moderate (after unilateral 30-min CCA occlusion) to moderate and severe (after bilateral 40-min CCA occlusion) scattered structural and functional changes of the SMC with large areas of clearing in the «porous» neuropil, severe perivascular and perineuronal edema of the astrocyte processes developed. The latter was associated with a moderate reduction of the total neuronal density.Conclusion. After occlusion of CCA, signs of edema with cellular swelling appeared in the SMC amid dystrophic and necrotic pyramidal neurons and activated neuroglial cells. To a greater extent, the signs of brain swelling were evident three days after bilateral 40-min occlusion of CCA.

Non-Invasive Remote Ischemic Preconditioning May Protect the Gastric Mucosa Against Ischemia-Reperfusion-Induced Injury Through Involvement of Glucocorticoids.

Remote ischemic preconditioning (RIPC) is one of the most effective approaches to attenuate tissue injury caused by severe ischemia-reperfusion (I/R). Experimental studies have demonstrated that RIPC is capable of producing a protective effect not only on heart, but also on brain, lungs, kidneys, liver, intestine, and stomach. We previously demonstrated that glucocorticoids participate in protective effect of local gastric ischemic preconditioning against I/R-induced gastric injury. In the present study we investigated whether RIPC may protect the gastric mucosa against I/R-induced injury through involvement of glucocorticoids. Anesthetized fasted Sprague Dawley male rats were exposed to prolonged gastric I/R (30 min occlusion of celiac artery followed by 3 h of reperfusion) alone or with preliminary brief RIPC (10 min non-invasive occlusion of right hind limb blood flow followed by reperfusion for 30 min). First, we investigated the effect of RIPC on I/R-induced injury by itself. Then to study the role of glucocorticoids similar experiments were carried out: 1) in rats pretreated with the inhibitor of glucocorticoid synthesis, metyrapone (30 mg/kg, i.p), and in control animals; 2) in adrenalectomized rats without or with corticosterone replacement (4 mg/kg, s.c.) and in sham-operated animals; 3) in rats pretreated with glucocorticoid receptor antagonist RU-38486 (20 mg/kg, s.c.) and in control animals. I/R induced corticosterone rise and resulted in the gastric erosion formation. RIPC significantly reduced the erosion area in control animals. Metyrapone injected shortly before RIPC caused a decrease in plasma corticosterone levels and prevented the gastroprotective effect of RIPC and, moreover, further aggravated the deleterious effect of I/R. Adrenalectomy performed 1 week before experiment created long-lasting corticosterone deficiency and had no effect on the gastroprotective effect of RIPC. Nevertheless, corticosterone replacement which mimics the corticosterone rise, similar to RIPS, significantly reduced erosion areas of gastric mucosa in adrenalectomized rats supporting the role of glucocorticoids in gastroprotection. RU-38486, which occupied glucocorticoid receptors, similar to metyrapone prevented the gastroprotective effect of RIPC and, moreover, further aggravated the deleterious effect of I/R. The results of the present study demonstrate for the first time that RIPC may protect the gastric mucosa against I/R-induced injury through involvement of glucocorticoids.