We investigated the effects of the angiotensin-converting enzyme inhibitor captopril on neurologic outcome in a rat model of incomplete cerebral ischemia. Twenty male Sprague-Dawley rats were anesthetized with 70% nitrous oxide in oxygen and fentanyl (10 micrograms x kg-1 i.v. bolus, 25 micrograms x kg-1 x hr-1 i.v. continuous infusion). Animals in group 1 (n = 10) received no angiotensin-converting enzyme inhibitor while animals in group 2 (n = 10) were given 10 mg x kg-1 i.v. captopril 30 minutes prior to the ischemic period. Ischemia was produced by unilateral carotid artery ligation and hemorrhagic hypotension to 35 mm Hg for 30 minutes. Body temperature, arterial blood gases, and arterial pH were maintained constant. Neurologic outcome was evaluated every 24 hours for 3 days using a graded deficit score (0, normal; 18, stroke-related death). On the third day after ischemia, captopril significantly improved neurologic outcome (median deficit score = 4) compared with controls (median deficit ...
TY - JOUR. T1 - Treatment of acute focal cerebral ischemia with dimethyl sulfoxide. AU - Little, J. R.. AU - Cook, A.. AU - Lesser, Ronald P. PY - 1981. Y1 - 1981. N2 - The object of this investigation was to study the effects of dimethyl sulfoxide (DMSO) upon the evolution of cerebral infarction. Twenty adult cats anesthetized lightly with ketamine hydrochloride underwent right middle cerebral artery occlusion for 6 hours. Ten cats were not treated and 10 cats received DMSO (2.5 g/kg i.v.) immediately after occlusion. Regional cerebral blood flow (rCBF) changes in the right sylvian region were similar in the untreated and treated groups. The mean rCBF before occlusion was 46 ± 10 ml/100 g/minute in the untreated group and 45 ± 10 ml/100 g/minute in the treated group. Eight cats in both groups had rCBF measurements consistently below 18 ml/100 g/minute during the 6-hour period after occlusion. An index of erythrocyte flow was determined by measuring the transit of technetium-99 (99Tc)-labeled ...
The effects of isosmolar loads of glucose and saline after onset of focal cerebral ischaemia (middle cerebral artery occlusion) were compared in cats. In cats given saline cerebral blood flow (CBF) fell and then rose slightly on the marginal gyrus (infarct penumbra). There was a sustained fall in CBF on the suprasylvian and ectosylvian gyri (infarct core). Reperfusion restored blood flow to preocclusion levels with no overall postischaemic hypoperfusion. Below ischaemic flows of 14 ml/100 g/min brain specific gravity was reduced in a smaller proportion of gyri by contrast with non reperfused cortex, suggesting that in some gyri resolution of cerebral oedema had taken place. GABA uptake was normal in the infarct core, but was reduced within the ischaemic penumbra. In animals given glucose after occlusion, CBF fell on the marginal gyrus during reperfusion. The degree of resolution of cerebral oedema was less than in saline infused cats. GABA uptake showed a pattern of abnormality similar to that ...
Interleukin-1 (IL-1) is a key regulator of inflammation and ischaemic brain injury, but the contribution of central and peripheral sources of IL-1 to brain injury is not well understood. Here we show that haematopoietic-derived IL-1 is a key driver of ischaemic brain injury. Wild type (WT) mice transplanted with IL-1αβ-deficient bone marrow displayed a significant (40%) reduction in brain injury induced by focal cerebral ischaemia compared to WT mice transplanted with WT bone marrow. This was paralleled by improved neurological outcome and the almost complete absence of splenic-derived, but not liver-derived, IL-1α after stroke in WT mice lacking haematopoietic-derived IL-1. IL-1αβ knockout (KO) mice transplanted with IL-1αβ-deficient bone marrow showed a 60% reduction in brain injury compared to WT mice receiving WT bone marrow. Transplantation of WT bone marrow in IL-1αβ KO mice resulted in a similar level of blood-brain-barrier injury to that observed in WT mice receiving ...
OBJECTIVES: Prolonged global cerebral ischaemia leads to irreversible injury, often with lethal outcome. Brain injuries are partly caused by the uncontrolled reperfusion that occurs once the circulation is re-established. Recent animal experiments suggest that controlled reperfusion following lengthy ischaemia might prevent severe brain injury. This study aimed at further exploring cerebral alterations and outcome following prolonged global cerebral ischaemia and mechanically manipulated reperfusion.. METHODS: Three groups of pigs were included; one sham operated (n = 3) and two that underwent 30-min global cerebral ischaemia. All vessels that supply the brain were isolated intrathoracically, after which they were occluded for 30 min in the ischaemic groups. In one of the ischaemic groups uncontrolled reperfusion was applied (URep, n = 6), i.e. normal circulation was restored 30 min after arrested cerebral circulation. The second ischaemic group received mechanical reperfusion (MRep, n = 6) with ...
TY - JOUR. T1 - Serial diffusion tensor MRI after transient and permanent cerebral ischemia in nonhuman primates. AU - Liu, Yutong. AU - DArceuil, Helen E.. AU - Westmoreland, Susan. AU - He, Julian. AU - Duggan, Michael. AU - Gonzalez, R. Gilberto. AU - Pryor, Johnny. AU - De Crespigny, Alex J.. N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.. PY - 2007/1. Y1 - 2007/1. N2 - BACKGROUND AND PURPOSE - We measured the temporal evolution of the T2 and diffusion tensor imaging parameters after transient and permanent cerebral middle cerebral artery occlusion (MCAo) in macaques, and compared it to standard histological analysis at the study end point. METHODS - Stroke was created in adult male macaques by occluding a middle cerebral artery branch for 3 hours (transient MCAo, n=4 or permanent occlusion, n=3). Conventional MRI and diffusion tensor imaging scans were performed 0 (acute day), 1, 3, 7, 10, 17, and 30 days after MCAo. Animals were euthanized after the final scan and the ...
TY - JOUR. T1 - Intraluminal suture occlusion of the middle cerebral artery in spontaneously hypertensive rats. AU - Doǧan, Aclan. AU - Başkaya, Mustafa K.. AU - Rao, V. L.Raghavendra. AU - Rao, A. Muralikrishna. AU - Dempsey, Robert J.. PY - 1998/4. Y1 - 1998/4. N2 - In models of middle cerebral artery occlusion using intraluminal suture, the size and the distribution of ischemic injury vary considerably among laboratories. In transcranial models of cerebral ischemia, a more consistent cerebral ischemic lesion is seen in Spontaneously Hypertensive rats (SHR). In the present study, we performed intraluminal suture occlusion of the MCA in SHR and compared its reproducibility with those in Sprague-Dawley (SD) rats. Male SHR and SD rats were anesthetized with halothane and subjected to 2 h of temporary middle cerebral artery occlusion by an intraluminal suture. Comparisons of regional cerebral blood flow figures taken throughout the experiment and lesion volume figures taken at 24 h after ...
Hypoxic-ischaemic brain injury at birth is associated with 1-3/1000 cases of moderate to severe encephalopathy. Previously, we have shown that connexin 43 hemichannel blockade, with a specific mimetic peptide, reduced the occurrence of seizures, improved recovery of EEG power and sleep state cycling, and improved cell survival following global cerebral ischaemia. In the present study, we examined the dose response for intracerebroventricular mimetic peptide infusion (50 µmol/kg/h for 1 h, followed by 50 µmol/kg/24 h (low dose) or 50 µmol/kg/h for 25 h (high dose) or vehicle only (control group), starting 90 min after the end of ischaemia), following global cerebral ischaemia, induced by 30 min bilateral carotid artery occlusion, in near-term fetal sheep (128 ± 1 days gestation). Both peptide infusion groups were associated with a transient significant increase in EEG power between 2-12 h after ischaemia. The ischaemia-low dose group showed a significant recovery of EEG power from day five compared
Modern functional brain imaging techniques rely on the constancy of the neurovascular coupling process, measured by its hemodynamic response function (HRF). Nevertheless, brain pathology may alter the HRF confounding the interpretation of imaging studies. We have recently proposed a method to investigate HRF by taking advantage of the discontinuous burst-suppression (BS) EEG pattern induced by chloral-hydrate anesthesia. BS also occurs during reperfusion following global ischemia (GCI). The aim of this study was to investigate in rats whether the HRF is altered during early reperfusion after a minimally injuring GCI. In 6 male Wistar rats (control), BS patterns were induced by an overdose of chloral-hydrate. In other 5 rats, BS was induced by a 5-minute GCI using a variation of the 4-vessel occlusion model. Simultaneous electroencephalo-graphic (EEG) activity and Laser Doppler (LD) signal were recorded from the left hemisphere. During recovery following GCI, with decreasing bursting frequency ...
The present study shows that PC-SOD, the lecithinized form of SOD, decreased infarct volume and improved neurological outcomes at different time points after focal cerebral ischemic injury. PC-SOD decreased oxidative stress and provided neuronal protection through antiapoptotic mechanisms.. Previous studies have highlighted that unmodified SOD plays an important role in attenuating different forms of brain injury, including cerebral ischemia.1,2,3 However, its short in vivo half-life and low tissue affinity have hampered the practical use of unmodified SOD formulations.4 The enzymatic activity of PC-SOD is comparable to that of unmodified SOD. The in vitro activity of unmodified SOD by the xanthine-xanthine oxidase method was 3467 U/mg, whereas that of PC-SOD was 2876 U/mg. Therefore, the activity of PC-SOD was equivalent to 83% of unmodified SOD.15 PC-SOD, however, has many advantages, such as longer in vivo half-life, greater tissue affinity, and better drug delivery, resulting in ...
Brain ischemia (a.k.a. cerebral ischemia, cerebrovascular ischemia) is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus to the death of brain tissue or cerebral infarction / ischemic stroke. It is a sub-type of stroke along with subarachnoid hemorrhage and intracerebral hemorrhage. Ischemia leads to alterations in brain metabolism, reduction in metabolic rates, and energy crisis. There are two types of ischemia: focal ischemia, which is confined to a specific region of the brain; and global ischemia, which encompasses wide areas of brain tissue. The main symptoms involve impairments in vision, body movement, and speaking. The causes of brain ischemia vary from sickle cell anemia to congenital heart defects. Symptoms of brain ischemia can include unconsciousness, blindness, problems with coordination, and weakness in the body. Other effects that may result from brain ischemia are stroke, ...
TY - JOUR. T1 - Postischemic gene transfer of midkine, a neurotrophic factor, protects against focal brain ischemia. AU - Takada, J.. AU - Ooboshi, H.. AU - Ago, T.. AU - Kitazono, T.. AU - Yao, H.. AU - Kadomatsu, K.. AU - Muramatsu, T.. AU - Ibayashi, S.. AU - Iida, M.. PY - 2005/3/1. Y1 - 2005/3/1. N2 - Gene therapy may be a promising approach for treatment of brain ischemia. In this study, we examined the effect of postischemic gene transfer of midkine, a heparin-binding neurotrophic factor, using a focal brain ischemia model with the photothrombotic occlusion method. At 90 min after induction of brain ischemia in spontaneously hypertensive rats, a replication-deficient recombinant adenovirus encoding mouse midkine (AdMK, n = 7) or a control vector encoding β-galactosidase (Adβgal, n = 7) was injected into the lateral ventricle ipsilateral to ischemia. At 2 days after ischemia, we determined infarct volume by 2,3,5-triphenyltetrazolium chloride staining. There were no significant ...
Introduction: The aim of the study was to evaluate the endothelioprotective activity of 4-hydroxy-3,5-di-tret-butylcinnamic acid in conditions of experimental cerebral ischemia. Materials and methods: The brain ischemia was reproduced by the method of irreversible right-sided thermocoagulation of the middle cerebral artery. As comparative drugs, mexidol (30 mg/kg) and sulodexide (30 U/kg) were used. The vasodilating function of the vascular endothelium was assessed by the change in the rate of cerebral blood flow when the synthesis of nitric oxide was modified. Antithrombotic function was assessed by changes in the concentration of thromboxane A2, fibrinogen, von Willebrand factor activity and platelet aggregation activity. Serum concentration of C-reactive protein served as a marker of the state of anti-inflammatory endothelial function. To determine the potential mechanism of endothelioprotective activity of 4-4-hydroxy-3,5-di-tret-butylcinnamic acid, the anti-radical activity of
אינדוקציה כירורגי של נזק מוחי איסכמי בחולדה הוא מודל בשימוש נרחב עבור מחקר שבץ. כאן אנו מדגימים את האינדוקציה של איסכמיה מוחית המוקד על ...
Aging is a risk factor for stroke. Animal models of stroke have been widely used to study the pathophysiology of ischemic stroke, which in turn helped to develop numerous therapeutic strategies. Despite the considerable success of therapeutic strategies in animal models of ischemic stroke, almost all of them have been proved to be unsuccessful in the clinical trials. One of explanation is that data obtained from young animals may not fully resemble the effects of ischemic stroke in aged animals or elder patients, causing the discrepancy between animal experiments and clinical trials. To investigate these differences with regard to age, pathway specific gene arrays were used to identify and isolate differentially expressed genes in periinfarct following focal cerebral ischemia. The results from this study showed a persistent up-regulation of pro-apoptotic and inflammatory-related genes up to 14 days post stroke, a 50% reduction in the number of transcriptionally active stem cell-related genes and ...
Aging is a risk factor for stroke. Animal models of stroke have been widely used to study the pathophysiology of ischemic stroke, which in turn helped to develop numerous therapeutic strategies. Despite the considerable success of therapeutic strategies in animal models of ischemic stroke, almost all of them have been proved to be unsuccessful in the clinical trials. One of explanation is that data obtained from young animals may not fully resemble the effects of ischemic stroke in aged animals or elder patients, causing the discrepancy between animal experiments and clinical trials. To investigate these differences with regard to age, pathway specific gene arrays were used to identify and isolate differentially expressed genes in periinfarct following focal cerebral ischemia. The results from this study showed a persistent up-regulation of pro-apoptotic and inflammatory-related genes up to 14 days post stroke, a 50% reduction in the number of transcriptionally active stem cell-related genes and ...
TY - JOUR. T1 - Bone morphogenetic protein-6 reduces ischemia-induced brain damage in rats. AU - Wang, Yun. AU - Chang, Chen Fu. AU - Morales, Marisela. AU - Chou, Jenny. AU - Chen, Hui Ling. AU - Chiang, Yung Hsiao. AU - Lin, Shinn Zong. AU - Cadet, Jean Lud. AU - Deng, Xiaolin. AU - Wang, Jia Yi. AU - Chen, Su Yu. AU - Kaplan, Paul L.. AU - Hoffer, Barry J.. PY - 2001. Y1 - 2001. N2 - Background and Purpose - Bone morphogenetic protein-6 (BMP6) and its receptors are expressed in adult and fetal brain. Receptors for BMP6 are upregulated in adult brain after injury, leading to the suggestion that BMP6 is involved in the physiological response to neuronal injury. The purpose of this study was to determine whether there was a neuroprotective effect of BMP6 in vivo and in vitro. Methods - Lactate dehydrogenase and microtubule-associated protein-2 (MAP-2) activities were used to determine the protective effect of BMP6 against H2O2 in primary cortical cultures. The neuroprotective effects of BMP6 ...
TY - JOUR. T1 - Ablation of Neurogenesis Attenuates Recovery of Motor Function after Focal Cerebral Ischemia in Middle-Aged Mice. AU - Sun, Fen. AU - Wang, Xiaomei. AU - Mao, Xiao Ou. AU - Xie, Lin. AU - Jin, Kunlin. PY - 2012/10/26. Y1 - 2012/10/26. N2 - Depletion of neurogenesis worsens functional outcome in young-adult mice after focal cerebral ischemia, but whether a similar effect occurs in older mice is unknown. Using middle-aged (12-month-old) transgenic (DCX-TK(+)) mice that express herpes simplex virus thymidine kinase (HSV-TK) under control of the doublecortin (DCX) promoter, we conditionally depleted DCX-positive cells in the subventricular zone (SVZ) and hippocampus by treatment with ganciclovir (GCV) for 14 days. Focal cerebral ischemia was induced by permanent occlusion of the middle cerebral artery (MCAO) or occlusion of the distal segment of middle cerebral artery (dMCAO) on day 14 of vehicle or GCV treatment and mice were killed 24 hr or 12 weeks later. Increased infarct volume ...
ABSTRACT MECHANISMS OF PERSISTENT TRANSLATION ARREST FOLLOWING GLOBAL BRAIN ISCHEMIA and REPERFUSION by JILL T. JAMISON December 2011 Advisor: Donald J. DeGracia, Ph.D. Major: Physiology Degree: Doctor of Philosophy The information presented here studies the mechanisms that underlie persistent translation arrest (TA) following global brain ischemia and reperfusion (I/R). To summarize the main findings I have discovered a new mechanism for prolonged post-ischemic TA that correlated exactly with in vivo translation rates and correlated precisely with cell outcome. Through the extensive colocalization studies, my results indicate that the mRNA granules are ribonomic structures involved with mRNA regulation. This finding is significant because it shifts the focus onto mRNA metabolism and away from ribosomal molecular biology. I have identified new pathways to investigate for understanding why there is selective delayed death in post-ischemic neurons, however my work also gives insight into why resistant
It is crucial to establish an MCAO/R animal model according to the clinical characteristics of a human cerebral natural infarct. The model characteristics are as follows: i) single damage mechanism that is easy to study; ii) simple method, small wound, easy to control condition, stable infarct site, and distinct symptomatic reaction and high achievement ratio; iii) uniformity of cerebral infarction and good reproducibility; and iv) necrotic brain tissue following injury, with a similar pathophysiological process to clinical cerebral ischemia. In this study, a rat cerebral ischemia-reperfusion injury model was established according to the Zea-Longa method (4). Following cerebral ischemia for 1 h, the rats developed severe nervous and behavioral functional impairment symptoms, indicating the establishment of a successful model.. The Bederson (5) score method was employed for qualitative and semiquantitative evaluation, with particular emphasis on motor function evaluation. The balance beam walking ...
1. Li PA, He Q. Mechanisms of hyperglycemia-enhanced ischemic brain damage. Transl Med Res. 2013;3:1-11 2. Capes SE, Hunt D, Malmberg K, Pathak P, Gerstein HC. Stress hyperglycemia and prognosis of stroke in nondiabetic and diabetic patients: a systematic overview. Stroke. 2001;32:2426-2432 3. Rajesh G, Ajay C, Frederick M, Paresh D. Hyperglycemia, insulin, and acute ischemic stroke: A mechanistic justification for a trial of insulin infusion therapy. Stroke. 2006;37:267-273 4. Balan IS, Fiskum G, Hazelton J, Cotto-Cumba C, Rosenthal RE. Oximetry-guided reoxygenation improves neurological outcome after experimental cardiac arrest. Stroke. 2006;37:3008-3013 5. Cipolla MJ, Godfrey JA. Effect of hyperglycemia on brain penetrating arterioles and cerebral blood flow before and after ischemia/reperfusion. Transl Stroke Res. 2010;1:127-134 6. Stead LG, Gilmore RM, Bellolio MF, Mishra S, Bhagra A, Vaidyanathan L, Decker WW, Brown RD Jr. Hyperglycemia as an independent predictor of worse outcome in ...
Increasing evidence suggests that toll-like receptors (TLRs) play an important role in cerebral ischemia-reperfusion injury. The endogenous ligands released from ischemic neurons activate the TLR signaling pathway, resulting in the production of a large number of inflammatory cytokines, thereby causing secondary inflammation damage following cerebral ischemia. However, the preconditioning for minor cerebral ischemia or the preconditioning with TLR ligands can reduce cerebral ischemic injury by regulating the TLR signaling pathway following ischemia in brain tissue (mainly, the inhibition of the TLR4/NF-κB signaling pathway and the enhancement of the interferon regulatory factor-dependent signaling), resulting in TLR ischemic tolerance. Additionally, recent studies found that postconditioning with TLR ligands after cerebral ischemia can also reduce ischemic damage through the regulation of the TLR signaling pathway, showing a significant therapeutic effect against cerebral ischemia. These studies
Cerebral ischemia is a life-threatening condition associated with a substantial morbidity and mortality. Hyperglycemia, a common coexisting phenomenon in both stroke and cardiac arrest (CA), may further aggravate ischemic brain injury. To date, the therapeutic possibilities are lim-ited and the search for new treatment modalities is warranted. One aspect of such a research could be to better understand the cerebral pathogenesis induced by hyperglycemic ischemia-reperfusion.. We investigated the combination of ischemia and hyperglycemia in two experimental models of stroke and CA. The aims were to test the neuroprotective potential of the sulfonated nitrone 2-sulfophenyl-N-tert-butylnitrone (S-PBN) in focal hyperglycemic cerebral ischemia (1), to outline the short-terms effects of hyperglycemia in prolonged (2) and short CA (3) and to performed a global transcriptome analysis of brain from hyperglycemic and normoglycemic CA (4).. In a stroke model rats were made hyperglycemic prior to transient ...
To determine whether the Tat-K13 following systemic application can prevent the ischemic nuclear PTEN translocation and hence reduce the ischemic neuronal injuries, we first tested whether Tat-K13, following systemic application, could enter neurons in the ischemic penumbra using a fluorophore-tagged peptide Tat-K13-carboryfluorescein. As shown in Figure 3B, this fluorescent Tat-K13 (10 mg/kg, i.v.) administered 6 h after stroke onset not only effectively entered the brain, but was enriched in neurons in the infarct area within 1 h following application (Fig. 3B). This apparent enrichment in the infarct brain area is likely due to a transient increase in blood-brain-Barrier leakage following ischemic insults (Belayev et al., 1996; Fernandez-Lopez et al., 2012) These results indicate that post-stroke systemic administration could effectively deliver this peptide into neurons in the ischemic/infarct regions of the brain.. Having proved the effective delivery of the peptide into ischemic regions, ...
DrLinOng. Chan SJ, Esposito E, Hayakawa K, Mandaville E, Smith RAA, Guo S, Niu W, Wong PT-H, Cool SM, Lo EH, Nurcombe V. Vascular Endothelial Growth Factor 165-Binding Heparan Sulfate Promotes Functional Recovery From Cerebral Ischemia. Stroke. 2020;51:2844-2853.. Angiogenesis and neurogenesis are crucial processes for brain recovery after stroke. While the brain has the capacity to form new cerebral blood vessels and to generate new neurons from neural stem cells after stroke, these self-repair mechanisms are limited. Therefore, strategies to promote brain restorative processes beyond the endogenous recovery are highly desirable. In this study, Chan and colleagues demonstrated that an exogenously applied heparan sulfate with increased affinity for vascular endothelial growth factor was able to enhance angiogenesis and neurogenesis within the peri-infarct regions, as well as to promote neurological recovery after experimental stroke.. The team first purified heparan sulfate variant 7, a ...
phdthesis{e6a24cb9-3a1a-4b11-91f1-3152114bb8fb, abstract = {Enriched environment (EE) housing significantly ameliorates neurological deficits induced by cortical brain ischemia without changing infarction size, suggesting that EE-related functional benefits are associated with neuronal plasticity events in the remaining tissue. Brain-derived neurotrophic factor (BDNF), nerve growth factor-induced gene A (NGFI-A) and corticosteroid receptors (mineralocorticoid receptor, MR; glucocorticoid receptor, GR) have been demonstrated to be involved in brain plasticity. The purpose of this thesis was to determine if post-ischemic housing conditions had a significant effect on transcription and/or translation of BDNF, NGFI-A and corticosteroid receptors. We found that BDNF gene was down regulated in EE-housed rats when compared to the rats housed in standard cages at 2~12 days after cortical brain ischemia in peri-infarct cortex, contralateral cortex and bilateral hippocampus. The protein level of BDNF in ...
Female gender, which is abolished following ovariectomy and reproductive senescence, is associated with improved outcome following cerebral stroke. Estrogen replacement partially restores this benefit of the female gender but the effect of progesterone in hormone-deficient animals is currently unknown. We evaluated various outcomes following middle cerebral artery occlusion (MCAO) in ovariectomised female mice, with a physiologically relevant restoration of progesterone levels. Ovariectomised female mice had significantly elevated plasma (P=,0.05) and brain progesterone levels (P=,0.01) following implantation of a 21-day release pellet (50mg) compared with mice that received placebo implants 7 days prior to undergoing 60 min MCAO. Assessment of well-being (body weight recovery) and neurological score at 24h and 48h post-MCAO indicated that MCAO significantly worsened outcome compared with sham-operated mice but progesterone had no effect. MCAO resulted in a substantial lesion formation and a ...
Bilateral carotid occlusion coupled with systemic hypotension produces global brain ischemia in the rat, resulting in damage to the...
Dysregulated microRNAs (miRNAs) are crucial regulators of cerebrovascular conditions, including ischemic stroke. Circulating miR-125a-5p is associated with ischemic stroke and may have clinical utility as an early diagnostic biomarker. This study conducted a series of experiments that were...
Older research outputs will score higher simply because theyve had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 222,049 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 1st percentile - i.e., 1% of its contemporaries scored the same or lower than it ...
Reversible protein phosphorylation is under the control of opposing activities of protein kinases and protein phosphatases, and has a crucial role in the regulation of cellular signal transduction in a plethora of neural cell functions, including neurogenesis, differentiation, gene transcription and cell death signalling (Klumpp & Krieglstein, 2002b). During the symposium, expert reviews of research on reversible protein phosphorylation, examples from screening approaches for kinase functions in neurons and studies on particular signalling pathways highlighted the importance of this fast‐emerging topic for the understanding of neuronal cell death, and the development of novel neuroprotective strategies.. Protein kinases have been established as key regulators in many important cellular processes, such as proliferation, maintenance of cell shape, survival signalling and apoptosis. Approximately 500 genes encode members of the kinase family in the human genome, and the predicted human kinome ...
Diabetes is a major risk factor for ischemic stroke and is associated with increased mortality. Additionally, hyperglycemia, a common complication in acute stroke, is associated with poor outcome.In order to identify the correlation between blood glucose and early mortality, multiple logistic regression analyses were used and odds ratios calculated in a retrospective study of 447 stroke patients. Eighty-one patients (18%) had diabetes. The odds ratios for 30-day case-fatality and blood glucose were 1.9 and 1.6 in diabetic and non-diabetic patients respectively. Optimal blood glucose concentrations in respective group were 10.3 and 6.3 mmol/L, as determined by receiver operator characteristic (ROC) curves.Cerebral ischemia triggers different signaling pathways including mitogen-activated protein kinases (MAPK) which regulate fundamental cell functions. In an experimental rat model of combined hyperglycemia and transient middle cerebral artery occlusion (MCAO), the activation pattern of one such ...
Several experimental studies have indicated that nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox) exert detrimental effects on ischemic brain tissue; Nox-knockout mice generally exhibit resistance to damage due to experimental stroke following middle cerebral artery occlusion (MCAO). Furthermore, our previous MCAO study indicated that infarct size and blood-brain barrier breakdown are enhanced in mice with pericyte-specific overexpression of Nox4, relative to levels observed in controls. However, it remains unclear whether Nox affects the stroke outcome directly by increasing oxidative stress at the site of ischemia, or indirectly by modifying physiological variables such as blood pressure or cerebral blood flow (CBF ...
Cerebral Resuscitation After Global Brain Ischemia: Linking Research to Practice | Richmond, Therese S. | download | BookSC. Download books for free. Find books
The initial ASPECTS-CTP lesion was significantly larger than the final infarct determined by ASPECTS in case of recanalization. Initial perfusion lesion, including CBV, is reversible in case of reperfusion, especially in early reperfusion.
Cerebral hyperperfusion, or reperfusion syndrome, is a rare, but serious, complication following revascularization. Hyperperfusion is defined as a major increase in ipsilateral cerebral blood flow (CBF) that is well above the metabolic demands of the brain tissue.
TY - CHAP. T1 - Histopathology of Cerebral Ischemia and Stroke. AU - Dalton Dietrich, W.. PY - 2017/3/7. Y1 - 2017/3/7. N2 - Ischemic stroke is a serious neurological problem and one of the leading causes of death and disability worldwide. The histopathological consequences of stroke are complex and may result in a variety of deficits including severe motor and cognitive disturbances. The histopathological consequences of severe focal ischemia are well described with characteristic structural changes occurring in both gray and white brain regions depending on the severity, location, and duration of the ischemic insult. Following focal ischemic injury, neuronal, astrocytic, vascular endothelial, and inflammatory cell changes occur. In white mater tracts, axonal injury with oligodendrocyte damage and subsequent demyelination are also commonly observed. In contrast, less severe or more transient ischemic insults can lead to patterns of selective neuronal injury whereby vulnerable neuronal ...
In our previous study, β-hydroxybutyrate (BHB) was found to prolong survival time and to inhibit cerebral edema by improving energy metabolism in the hypoxia, anoxia and global cerebral ischemia models. In this study, the cerebroprotective effect of BHB was examined in rats with permanent (p)-occlusion and transient (t)-occlusion of middle cerebral artery (MCA). BHB (30 mg · kg,sup,−,/sup,,sup,1,/sup, · h,sup,−,/sup,,sup,1,/sup,) was continuously administered through the femoral vein. In rats with p-MCA occlusion, BHB significantly reduced infarct area at 24 h after the occlusion, but not at 72 h after the occlusion. In rats with 2-h t-MCA occlusion followed by 22-h reperfusion, BHB significantly reduced cerebral infarct area, edema formation, lipid peroxidation and neurological deficits. Moreover, in the t-MCA occlusion model, delayed administration of BHB started at 1 h after the initiation of the MCA occlusion also significantly reduced cerebral infarct area. Taking together the ...
1. Stub D, Bernard S, Duffy SJ, Kaye DM. Post cardiac arrest syndrome: a review of therapeutic strategies. Circulation. 2011;123:1428-35 2. Harukuni I, Bhardwaj A. Mechanisms of brain injury after global cerebral ischemia. Neurol Clin. 2006;24:1-21 3. Bernard SA, Gray TW, Buist MD, Jones BM, Silvester W, Gutteridge G. et al. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med. 2002;346:557-63 4. Camara AK, Bienengraeber M, Stowe DF. Mitochondrial approaches to protect against cardiac ischemia and reperfusion injury. Front Physiol. 2011;2:13 5. Honda HM, Korge P, Weiss JN. Mitochondria and ischemia/reperfusion injury. Ann N Y Acad Sci. 2005;1047:248-58 6. Perez-Pinzon MA, Stetler RA, Fiskum G. Novel mitochondrial targets for neuroprotection. J Cereb Blood Flow Metab. 2012;32:1362-76 7. Cour M, Loufouat J, Paillard M, Augeul L, Goudable J, Ovize M. et al. Inhibition of mitochondrial permeability transition to prevent the post-cardiac arrest ...
If the entire ischemic region supplied by the occluded artery evolved into infarction within minutes or even 1 to 2 hours after onset, there would be little if any opportunity to successfully intervene to improve functional and neurologic outcome. Abundant experimental data suggest that brain injury, secondary to an arterial occlusion, is a dynamic process involving varying degrees of early ischemic injury related primarily to the severity of local cerebral blood flow (CBF) impairment. Ischemic regions with very low CBF (,10 mL/100 g/min) rapidly become irreversibly damaged and are referred to as the ischemic core. [14] In stroke models, surrounding or intermixed zones of less severely impaired CBF (approximately 15 to 40 mL/100 g/min) occur and likely also exist in many ischemic stroke patients. This zone of mild to moderately reduced CBF relates to the concept of the ischemic penumbra originally suggested by Astrup et al. [15] As initially defined, the ischemic penumbra encompasses that ...
The present study aimed to investigate the anti-inflammatory effect of 4-methylcyclopentadecanone (4-MCPC) in rats suffering from a cerebral ischemia/ reperfusion (I/R) injury. In this study, the focal cerebral ischemia in rats was induced by middle cerebral artery occlusion (MCAO) for 2 h, and the rats were treated with 4-MCPC (8 mg/kg) just 0.5 h before reperfusion. The ischemic infarct volume was recorded 24 h after the MCAO. In addition, myeloperoxidase (MPO) activity and TNF-α and IL-1β levels in the ischemic cerebral cortex were determined by ELISA, while nuclear translocation of NF-κB p65 subunit and expression of p-IκBα were investigated by western blotting ...
This article examines the pathophysiology of lesions caused by focal cerebral ischemia. Ischemia due to middle cerebral artery occlusion encompasses a densely ischemic focus and a less densely ischemic penumbral zone. Cells in the focus are usually doomed unless reperfusion is quickly instituted. In …
The animal model of stroke that is most frequently used is a rat model of focal brain ischemia caused by middle cerebral artery occlusion (MCAO). Several studies have reported a link between levels of cell-free DNA (CFD) and neurologic outcome in human stroke. The purpose of this study was to assess brain injury and measure CFD levels in 2 models of MCAO in rats, and to determine whether brain injury correlates with CFD. A total of 60 rats were used for this study. Twenty rats underwent a sham procedure, 20 rats had MCAO using a monofilament, and 20 rats had MCAO with a silicon-coated filament. Groups were further divided into 2 subgroups. In 1 subgroup of 10 rats, neurologic performance [measured as a neurologic severity score, (NSS)] was measured at 1 and 24 hours after the procedure, and brain edema and infarct volume were determined at 24 hours. In the second subgroup of 10 rats, CFD was measured at 0, 1, 2, 4, 8, 12, and 24 hours and at 2, 3, 4, and 5 days. Neurologic performance (measured ...
The histologic description of cerebral ischemia is complex, and within most lesions there are regional variations in degrees of neuronal cell injury, edema, and neuropil disruption. These parameters of tissue injury were analyzed histopathologically in transient and permanent experimental cerebral ischemia in 15 rabbits and the results were spatially correlated with MR images of pre- and postmortem (formalin-fixed) brains. MR was performed at 1.5 T (eight animals) and at 0.38 T (seven animals). Areas of high signal on T2-weighted MR images were closely correlated with histologic signs of cytotoxic glial edema and with disruption of the neuropil (widening of the interstitial spaces in the background matrix of glial and neuronal cellular processes), but MR tended to underestimate the extent of ischemic neuronal injury, especially low-grade histologic changes (mild neuronal shrinkage and nuclear basophilia). Low-grade ischemic neuronal changes were often found in the penumbra zone of ischemic ...
TY - JOUR. T1 - Isovolemic hemodilution in experimental focal cerebral ischemia. Part 1. T2 - Effects on hemodynamics, hemorheology, and intracranial pressure. AU - Tu, Y. K.. AU - Heros, R. C.. AU - Candia, G.. AU - Hyodo, A.. AU - Lagree, K.. AU - Callahan, R.. AU - Zervas, N. T.. AU - Karacostas, D.. PY - 1988/1/1. Y1 - 1988/1/1. N2 - A total of 76 splenectomized dogs were entered in a study of the value and effects of isovolemic hemodilution. Of these, seven were not included in the analysis because of technical errors. Of the remaining 69 dogs, 35 were treated with hemodilution; 28 were subjected to a 6-hour period of temporary occlusion of the distal internal carotid artery and the proximal middle cerebral artery, and seven underwent a sham operation only, with arterial manipulation but no occlusion. The other 34 dogs were not subjected to hemodilution; 26 of these underwent temporary arterial occlusion and eight had a sham operation only. In each group the animals were about equally ...
In this experimental study, the neuroprotective effect of the xanthine oxidase inhibitor allopurinol on focal cerebral ischaemia created by permanent middle cerebral artery occlusion (MCAO) was investigated. Using high performance liquid chromatography (HPLC), we measured hypoxanthine, xanthine, and uric acid (UA) levels in rabbit brains following focal cerebral ischaemia. Rabbits were randomly and blindly assigned into four groups of eight animals each. The control groups received 2% carboxymethylcellulose solution, while 10% allopurinol 150 mg/kg was given to the treatment group 1 h before ischaemia. Each group was subdivided into two groups which were sacrificed 4 h or 24 h after ischaemia, respectively. UA and xanthine values of the rabbits in the control groups were quite high at both times and highest after 24 h, particularly in the centre of the ischaemia. A significant decrease in UA and xanthine values was observed in rabbits that were given allopurinol ( ...
Experimental focal cerebral ischemia was produced in monkeys (Macaca radiata) by occlusion of the right middle cerebral artery (MCA). The release of the lysosomal glycosidases, β-D-hexosaminidase, α-L-fucosidase and α-D-mannosidase into the soluble fraction in the right basal ganglia of the experimental animals was measured at different periods from 30 min to 12 hr after occlusion and compared with the corresponding sham operated control animals. There was a significant increase in the released lysosomal enzymes in the MCA occluded animals at all periods and particularly at 4 hr after occlusion. The CSF from the experimental animals also showed elevated levels of hexosaminidase and fucosidase. The free fatty acids (FFA) measured in the basal ganglia at 30 min and 2 hr after occlusion showed a 100 fold increase in the experimental animals. The predominant fatty acid released was linoleic acid (18:2) followed by arachidonic acid (20:4). Lipid peroxidation in the basal ganglia measured by the ...
Der ischämische Schlaganfall ist ein ernstzunehmendes Ereignis, welches rascher Rekanalisationstherapie bedarf. Hierfür stehen mehrere Therapieansätze zur Verfügung. Bildgebungsgestützte Patientenselektion zur individuell geeigneten Therapie kann das abschließende klinische Behandlungsergebnis des einzelnen Patienten maßgeblich verbessern. Der Alberta Stroke Program Early CT Score (ASPECTS), eine einfach und schnell anwendbare 10-Punkte-Skala zur Auswertung von Schädel-CT-Untersuchungen, wurde bereits als hilfreicher Prädiktor für das klinische Behandlungsergebnis nach erfolgreicher thrombolytischer Therapie identifiziert. Ein Nachteil der nativen Schädel-CT ist, dass der Infarktkern erst mit mehreren Stunden Verzögerung erkennbar wird. Das aktuelle Ausmaß des Infarktkerns kann durch Bestimmung des zerebralen Blutvolumens (CBV) anhand von Perfusions-CT-Untersuchungen schneller ermittelt werden. Diese Studie analysiert retrospektiv multimodale CT-Bildgebung einer Patientenkohorte von ...
TY - JOUR. T1 - Characteristics of Transient Cerebral Ischemia-Induced Deficits on Various Learning and Memory Tasks in Male Mongolian Gerbils. AU - Amano, Manabu. AU - Hasegawa, Masaya. AU - Hasegawa, Takaaki. AU - Nabeshima, Toshitaka. PY - 1993/1/1. Y1 - 1993/1/1. N2 - We examined the characteristics of 5-min cerebral ischemia-induced behavioral deficits in spontaneous locomotor activity and their effects on the performance of habituation (HAB), passive avoidance (PA) and 8-arm radial maze (RM) tasks in Mongolian gerbils. Performances in HAB, PA and RM were impaired within 2 days after occlusion, and gerbils showed hyperlocomotion during this period. Ten days after ischemia, the hyperlocomotion disappeared and performance in the HAB and PA was the same as that in the sham-operated group. Retention in the RM was impaired at that period, but this impairment was overcome, and retention recovered easily to the sham-operated level with a few additional trials. When the acquisition trial in the RM ...
Introduction: The detection and interpretation of early ischemic changes and salvageable brain parenchyma in acute ischemic stroke is critical in determining appropriate treatment. The Alberta Stroke Program Early CT Score (ASPECTS) was devised as a semi-quantitative method to accurately and reliably determine early ischemic changes in non-contrast CT (NCCT) and CT-perfusion (CTP) imaging. Our objective was to determine the inter-observer variability In assigning ASPECTS to admission NCCT, CTP, and follow-up imaging. Methods: A retrospective study was performed of imaging and clinical data obtained for ischemic stroke patients admitted to the MUSC stroke center between October 1, 2008 - September 30, 2009. Patients were included in the study if they: received a good quality CT and CTP at admission and follow-up NCCT and/or MRI within 7 days, had a National Institute of Health Stroke Scale (NIHSS) score ~ 8 at admission, and were ~ 45 years old. Patients were excluded if they: received a primary ...
In the setting of stroke, ischemia-related blood-brain barrier (BBB) dysfunction aggravates the cerebral edema, which critically impacts on the clinical outcome. Further, an impaired vascular integrity is associated with the risk of intracranial bleeding, especially after therapeutic recanalization. Therefore, the present study was aimed to investigate early vascular alterations from 30 min to 4 h after experimental middle cerebral artery occlusion (MCAO) in mice. Here, an extravasation of the permeability marker FITC-albumin was detectable in animals 2 and 4 h after MCAO. Thereby, BBB breakdown correlated with alterations of the endothelial surface, indicated by a discontinuous isolectin-B4 staining, while tight junction strands remained detectable using electron and immunofluorescence microscopy. Noteworthy, already 30 min after MCAO, up to 60% of the ischemia-affected vessels showed an endothelial edema, paralleled by edematous astrocytic endfeet, clearly preceding FITC-albumin extravasation. With
TY - JOUR. T1 - Activation of protein kinase c delta following cerebral ischemia leads to release of cytochrome c from the mitochondria via bad pathway. AU - Dave, Kunjan R.. AU - Bhattacharya, Sanjoy K.. AU - Saul, Isabel. AU - DeFazio, R. Anthony. AU - Dezfulian, Cameron. AU - Lin, Hung Wen. AU - Raval, Ami P.. AU - Perez-Pinzon, Miguel A.. PY - 2011/7/19. Y1 - 2011/7/19. N2 - Background: The release of cytochrome c from the mitochondria following cerebral ischemia is a key event leading to cell death. The goal of the present study was to determine the mechanisms involved in post-ischemic activation of protein kinase c delta (δPKC) that lead to cytochrome c release. Methods/Findings: We used a rat model of cardiac arrest as an in vivo model, and an in vitro analog, oxygen glucose deprivation (OGD) in rat hippocampal synaptosomes. Cardiac arrest triggered translocation of δPKC to the mitochondrial fraction at 1 h reperfusion. In synaptosomes, the peptide inhibitor of δPKC blocked OGD-induced ...
Platelet-Oriented Inhibition in New TIA and minor ischemic stroke (POINT) Trial, is a prospective, randomized, double-blind, multicenter trial with the primary null hypothesis that, in patients with TIA or minor ischemic stroke treated with aspirin 50-325 mg/day, there is no difference in the event-free survival at 90 days in those treated with clopidogrel (600 mg loading dose then 75 mg/day) compared to placebo when subjects are randomized within 12 hours of time last known free of new ischemic symptoms.. Its primary objective is to determine whether clopidogrel 75 mg/day by mouth after a loading dose of 600 mg of clopidogrel is effective in preventing major ischemic vascular events (ischemic stroke, myocardial infarction, and ischemic vascular death) at 90 days when initiated within 12 hours of TIA or minor ischemic stroke onset in patients receiving aspirin 50-325 mg/day (with a dose of 150-200 mg daily for 5 days followed by 75-100 mg daily strongly recommended).. Patients over 18 years of ...
Platelet-Oriented Inhibition in New TIA and minor ischemic stroke (POINT) Trial, is a prospective, randomized, double-blind, multicenter trial with the primary null hypothesis that, in patients with TIA or minor ischemic stroke treated with aspirin 50-325 mg/day, there is no difference in the event-free survival at 90 days in those treated with clopidogrel (600 mg loading dose then 75 mg/day) compared to placebo when subjects are randomized within 12 hours of time last known free of new ischemic symptoms.. Its primary objective is to determine whether clopidogrel 75 mg/day by mouth after a loading dose of 600 mg of clopidogrel is effective in preventing major ischemic vascular events (ischemic stroke, myocardial infarction, and ischemic vascular death) at 90 days when initiated within 12 hours of TIA or minor ischemic stroke onset in patients receiving aspirin 50-325 mg/day (with a dose of 150-200 mg daily for 5 days followed by 75-100 mg daily strongly recommended).. Patients over 18 years of ...
Sekhon, Ainslie and Griesdale identify Cerebral Oedema as one of the factors relevant to secondary brain injury after Hypoxic Ischaemic Brain Injury (HIBI). The authors note that Cerebral Oedema leads to intracranial hypertension which leads to Decreasing Cerebral Perfusion Pressure which leads to Decreasing Cerebral Blood Flow which leads to Reduced regional oxygen saturation…
Background: Given the limited time window available for treatment with tPA in acute ischemic stroke patients, guidelines recommend door-to-imaging time within 25 minutes of hospital arrival and a door-to-needle time (DTN) within 60 minutes. Despite temporal improvements in door-to-image and DTN, tPA treatment times remain suboptimal.. Objectives: To examine the contributions of door-to-image and imaging-to-needle times to delays in timely delivery of tPA to ischemic stroke patients, and to examine between-hospital variation in DTN.. Methods: A cohort analysis of 1,193 ischemic stroke patients treated with intravenous tPA from 2009-2012 at 25 Michigan hospitals participating in the Paul Coverdell National Acute Stroke Registry. The primary outcome was DTN (time in minutes from emergency department arrival to tPA delivery). Multi-level linear regression models included hospital-specific random effects.. Results: Mean patient age was 68 years, median NIHSS score was 11 (IQR 6-17), 51% were female, ...
Ischemic stroke causes neuronal cell death and triggers a cascade of inflammatory signals that contribute to secondary brain damage. Microglia, the brain-resident macrophages that remove dead neurons, play a critical role in the brains response to ischemic injury. Our previous studies showed that IRF2BP2 regulates peripheral macrophage polarization, limits their inflammatory response and reduces susceptibility to atherosclerosis. Here, we show that loss of IRF2BP2 in microglia leads to increased inflammatory cytokine expression in response to lipopolysaccharide challenge and impaired activation of anti-inflammatory markers in response to interleukin-4 (IL4) stimulation. Focal ischemic brain injury of the sensorimotor cortex induced by photothrombosis caused more severe functional deficits in mice with IRF2BP2 ablated in macrophages/microglia, associated with elevated expression of inflammatory cytokines in the brain. These mutant mice had larger infarctions 4 days after stroke associated with fewer
The effect of the free radical spin-trap alpha-phenyl-butyl-tert-nitrone (alpha-PBN) in permanent focal cerebral ischemia in rats was examined in two series of experiments. In the first, rats were subjected to permanent occlusion of the middle cerebral artery (MCAO) and treated 1 h after occlusion with a single dose of alpha-PBN (100 mg/kg) or saline. Body temperature was measured and controlled for the first 24 h to obtain identical temperature curves in the two groups. Cortical infarct volumes were determined on histological sections 7 days later. alpha-PBN did not significantly reduce infarct volume (control: 28.3+/-16.3 mm3 vs. alpha-PBN 23.7+/-7.4 mm3). In the second series of experiments, periinfarct depolarizations (PIDs) were recorded with an extracellular DC electrode at two locations in the ischemic penumbra for the initial 3 h following MCAO. alpha-PBN (100 mg/kg, single dose in conjunction with occlusion) significantly reduced the total number (median value of 3 PIDs in the control ...
article{3f0ddea8-dd33-4fdd-a777-97a29bef9f47, abstract = {Stroke outcome is determined by a complex interplay, where age and stroke severity are predominant predictors. Studies on hemorrhagic stroke indicate that APOE genotype is a predictor of poststroke outcomes,1,2 but results from studies on ischemic stroke are more conflicting.1,3 There is 1 study suggesting an influence of APOE genotype on age at ischemic stroke onset,4 and sex-specific effects on outcome have been reported.5 Taken together, there is a need for larger studies on APOE and ischemic stroke outcomes with integrated information on age, severity, and sex.,br/,,br/,The 3 common APOE alleles ε2, ε3, and ε4 can be separated by a combination of 2 single nucleotide polymorphisms (SNPs), rs429358 and rs7412. Thus, associations with APOE alleles are not directly captured in a regular genome-wide association study (GWAS), where each SNP is investigated separately. We derived the 3 common APOE alleles and investigated the interplay ...
Background: Nationwide data on the clinical profile and outcomes of ischemic stroke in younger adults are still scarce. Our aim was to analyze clinical characteristics and outcomes of young patients with first-ever ischemic stroke compared to older patients.Methods: The National Acute Stroke ISraeli (NASIS) registry is a nationwide prospective hospital-based study performed triennially. Younger adults, aged 50 years and younger, were compared with patients, aged 51-84 years regarding risk factors, clinical presentation, stroke severity, stroke etiology and outcomes. A logistic model for stroke outcome was fitted for each age group. Results: 336 first-ever ischemic strokes were identified among patients aged 50 years and younger and 3,243 among patients 51-84 years. Younger adults had lower rates of traditional vascular risk factors, but 82.7% had at least one of these risk factors. Younger adults were more likely to be male (62.8%), current smokers (47.3%), and to have a family history of stroke (7.4%).
Antiplatelet therapy for acute ischaemic stroke.. Cochrane Database Syst Rev. 2008;(3):CD000029. Authors: Sandercock PA, Counsell C, Gubitz GJ, Tseng MC. BACKGROUND: In patients with acute ischaemic stroke, platelets become activated. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and reduce the risk of early recurrent ischaemic stroke. This might reduce the risk of early death and improve long-term outcome in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage. OBJECTIVES: To assess the efficacy and safety of antiplatelet therapy in acute ischaemic stroke. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (last searched June 2007), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2007), MEDLINE (June 1998 to May 2007), and EMBASE (June 1998 to May 2007). In 1998, for a previous version of this review, we searched the register of the ...
Object. A critical review of the literature indicates that the effects of nitric oxide synthase (NOS) inhibitors on focal cerebral ischemia are contradictory. In this experiment the authors methodically examined the dose-dependent effects of two NOS inhibitors and two NO donors on cortical infarction volume in an animal model of temporary focal cerebral ischemia simulating potential ischemia during neurovascular interventions.. Methods. Ninety-two Wistar rats underwent 3 hours of combined left middle cerebral artery and bilateral common carotid artery occlusion after having been anesthetized with 1% halothane. A nonselective NOS inhibitor, NG-nitro-l-arginine-methyl-ester (l-NAME), and two NO donors, 3-morpholinosydnonimine hydrochloride and NOC-18, DETA/NO, (Z)-1-[2(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate, were administered intravenously 30 minutes before ischemia was induced. A selective neuronal NOS inhibitor, 7-nitroindazole (7-NI), was administered intraperitoneally ...
Evidence suggests that brain infiltration of lymphocytes contributes to acute neural injury after cerebral ischemia. However, the spatio-temporal dynamics of brain-infiltrating lymphocytes during the late stage after cerebral ischemia remains unclear. C57BL/6 (B6) mice were subjected to sham, photothrombosis, or 60-min transient middle cerebral artery occlusion (MCAO) procedures. Infarct volume, neurodeficits, production of reactive oxygen species (ROS) and inflammatory factors, brain-infiltrating lymphocytes, and their activation as well as pro-inflammatory cytokine IFN-γ production were assessed. Brain-infiltrating lymphocytes were also measured in tissue sections from post-mortem patients after ischemic stroke by immunostaining. In mice subjected to transient MCAO or photothrombotic stroke, we found that lymphocyte infiltration persists in the ischemic brain until at least day 14 after surgery, during which brain infarct volume significantly diminished. These brain-infiltrating lymphocytes express
BACKGROUND AND PURPOSE: The purpose of this study was to determine whether neuroprotection is feasible without cerebral blood flow augmentation in experimental permanent middle cerebral artery occlusion. METHODS: Rats were subjected to permanent middle cerebral artery occlusion by the suture occlusion method and were treated 1 hour thereafter with a single 5-minute intravenous infusion of the postsynaptic density-95 protein inhibitor Tat-NR2B9c (7.5 mg/kg) or saline (n=8/group). Arterial spin-labeled perfusion-weighted MRI and diffusion weighted MRI were obtained with a 4.7-T Bruker system at 30, 45, 70, 90, 120, 150, and 180 minutes postmiddle cerebral artery occlusion to determine cerebral blood flow and apparent diffusion coefficient maps, respectively. At 24 hours, animals were neurologically scored (0 to 5), euthanized, and the brains stained with 2-3-5-triphenyl tetrazolium chloride to ascertain infarct volumes corrected for edema. Additionally, the effects of Tat-NR2B9c on adenosine 5
BRAIN ischemia stroke is a devastating disease, with more than 10% stroke patients either severely disabled or dead. Although rodent fil- ament middle cerebral artery occlusion (MCAO) model can mimic human brain ischemic stroke well, its wide use was
Ischemic stroke, a major cause of mortality, is frequently accompanied by life-threatening cerebral edema. Aquaporin-4 (Aqp4), an astrocytic transmembrane water channel, is an important molecular contributor to cerebral edema formation. Past studies of Aqp4 expression and localization after ischemia examined grey matter exclusively. However, as white matter astrocytes differ developmentally, physiologically, and molecularly from grey matter astrocytes, we hypothesized that functionally important regional heterogeneity exists in Aqp4 expression and subcellular localization following cerebral ischemia. Subcellular localization of Aqp4 was compared between cortical and white matter astrocytes in postmortem specimens of patients with focal ischemic stroke versus controls. Subcellular localization and expression of Aqp4 was examined in rats subjected to experimental stroke. Volumetric analysis was performed on the cortex and white matter of rats subjected to experimental stroke. Following cerebral ischemia,
MECHANISMS OF TRANSLATION ARREST FOLLOWING FOCAL BRAIN ISCHEMIA by MONIQUE K. LEWIS August 2011 Advisor: Dr. Donald DeGracia Major: Physiology Degree: Doctor of Philosophy The loss of blood flow to the brain is termed ischemia and the subsequent resumption of blood flow is termed reperfusion. Brain ischemia and reperfusion (I/R) occurs primarily following resuscitation from cardiac arrest and stroke and presents one of the most significant clinical challenges. At present, there are no clinically effective pharmacologic interventions to halt brain damage following I/R. The major Aim of this dissertation will be to investigate possible mechanisms involved in neuron death following brain I/R, which may potentially lead to the development of effective therapies. A second major facet of this dissertation will be to address the issue of stroke and diabetes. It is very well established clinically that stroke outcome in diabetic patients is significantly worse than in non-diabetic patients. Diabetes has
33 New Zealand white rabbits were taken and randomly divided into a control group, a hyperbaric air group, and a hyperbaric oxyengation (HBO) group. All were reirrigated types following the creation of acute, incomplete cerebral ischemia. Respective measurements were taken of the overall carotid artery and interior jugular vein blood gases as well as cortical brain tissue homogenate amounts of 6-Keto-PGF1 and TXB2 contained. In conjunction with this, pathological investigations were made. The results were that: the amounts of 6-Keto-PGF1 contained for the HBO group were clearly greatly increased (P< 0.01). TXB2 clearly dropped (P< 0.05). Blood P02 in the HB0 group clearly went up (P < 0.0l). Pathological investigations showed that the HBO groups brain tissue damage was relatively light. Conclusion: there were clear effects on PGI2 and TXA2 with HBO when there was reirrigation after acute cerebral ischemia in the domestic rabbits. This is possibly one mechanism of HBO
Although post-ischemic inflammation induced by the innate immune response is considered an essential step in the progression of cerebral ischemia injury, the role of triggering receptor expressed on myeloid cells 2 (TREM2) in the pathogenesis of ischemic stroke remains to be elucidated. Here, we found that the transcriptional and post-transcriptional levels of TREM2 were increased in cultured primary microglia after oxygen-glucose deprivation and reoxygenation and in the ischemic penumbra of the cerebral cortex after middle cerebral artery occlusion (MCAO) and reperfusion in mice. TREM2 was mainly expressed in microglia, but not in astrocytes, neurons, or oligodendrocytes in mice subjected to MCAO. Manipulating TREM2 expression levels in vitro and in vivo significantly regulated the production of pro- and anti-inflammatory mediators after ischemic stroke. TREM2 overexpression markedly suppressed the inflammatory response and neuronal apoptosis. By contrast, TREM2 gene silencing intensified the ...
BACKGROUND AND PURPOSE: Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor inhibition has been hypothesized to provide neuroprotective efficacy after cerebral ischemia on the basis of the activity in experimental ischemia models of a variety of compounds with varying selectivity for AMPA over other glutamate receptor subtypes. CP-465,022 is a new, potent, and selective noncompetitive AMPA receptor antagonist. The present study investigated the ability of this compound to reduce neuronal loss after experimental cerebral ischemia to probe the neuroprotective potential of AMPA receptor inhibition. METHODS: To demonstrate that CP-465,022 gains access to the brain, the effects of systemic administration of CP-465,022 were investigated on AMPA receptor-mediated electrophysiological responses in hippocampus and on chemically induced seizures in rats. The compound was then investigated for neuroprotective efficacy in rat global and focal ischemia models at doses demonstrated to be
Background: Cerebral ischemia-reperfusion injury (CIRI) can cause brain tissue inflammation, neuronal degeneration, and apoptosis. There is increasing evidence that microRNAs (miRNA) exert neuroprotective effects by regulating the inflammatory process during cerebral ischemia-reperfusion injury. Additionally, it is increasingly acknowledged that neuroinflammation is regulated by Toll-like receptor 4 (TLR4). However, it is unclear whether miRNA can exert its neuroprotective effects by regulating TLR4-mediated inflammation. Methods: The effects of BMSCs over-expressing miR-202-3p on CIRI, angiogenesis in midbrain tissue, and the release of inflammatory factors (IFs) in the serum were measured using in vivo rat models. We also used SH-SY5Y cells to establish an ischemia-reperfusion in vitro cell model. The interaction between miR-202-3p and TLR4 was analyzed by overexpressing miR-202-3p and knocking down TLR4. Knockdown of TLR4 was performed using siRNA. Results:
TY - JOUR. T1 - Flow cytometric analysis of inflammatory cells in ischemic rat brain. AU - Campanella, Marilena. AU - Sciorati, Clara. AU - Tarozzo, Glauco. AU - Beltramo, Massimiliano. PY - 2002. Y1 - 2002. N2 - Background and Purpose - Inflammation plays a key role in cerebral ischemia through activation of microglia and infiltration by leukocytes. Flow cytometry is a well-established method for quantitative and qualitative analysis of inflammatory cells. However, this technique has not been applied to the study of cerebral ischemia inflammation. The aim of this study was to establish a flow cytometric method to measure inflammatory cells in ischemic brain. Methods - To perform flow cytometry on brain tissue, we developed 2 cell-isolation methods based on different mechanical dissociation and Percoll gradient separation techniques. The methods were tested on a rat model of permanent middle cerebral artery occlusion. Morphological and immunophenotypic analyses, with the use of anti-CD11b, ...
TY - JOUR. T1 - Post-ischaemic thyroid hormone treatment in a rat model of acute stroke. AU - Genovese, Tiziana. AU - Impellizzeri, Daniela. AU - Ahmad, Akbar. AU - Cornelius, Carolin. AU - Campolo, Michela. AU - Cuzzocrea, Salvatore. AU - Esposito, Emanuela. PY - 2013/6/4. Y1 - 2013/6/4. N2 - Stroke is a devastating brain injury that is a leading cause of adult disability with limited treatment options. We examined the effects of prohormone thyroxine (T4) and the underlying mechanisms in the post-ischaemic rat brain after transient focal cerebral ischemia-induced brain injury. Ischaemic injury was induced for 2 h by middle cerebral artery occlusion (MCAo) followed by 24-h reperfusion. T4 (1.1 μg/100 g BW) was administered by intraperitoneally injection twice, at 1 after the onset of ischemia and 6 h after reperfusion. Cerebral infarct area and infarct volume were measured 24 h after MCAo. Furthermore, the mechanism of neuroprotective effect of T4 was investigated with a focus on inflammatory ...
Antagonism of the adenosine A2A receptor (A2AR) has been shown to elicit substantial neuroprotective properties when given immediately after cerebral ischemia. We asked whether the continuous application of a selective A2AR antagonist within a clinically relevant time window will be a feasible and effective approach to treat focal cerebral ischemia. To answer this question, we subjected 20 male spontaneously hypertensive rats to permanent middle cerebral artery occlusion and randomized them equally to a verum and a control group. Two hours after stroke onset, the animals received a subcutaneous implantation of an osmotic minipump filled with 5 mg kg−1 day−1 8-(3-chlorostyryl) caffeine (CSC) or vehicle solution. The serum level of CSC was measured twice a day for three consecutive days. The infarct volume was determined at days 1 and 3 using magnetic resonance imaging. We found the serum level of CSC showing a bell-shaped curve with its maximum at 36 h. The infarct volume was not affected by ...
Lipoic acid (LA) is a naturally occurring compound and dietary supplement with powerful antioxidant properties. Although LA is neuroprotective in models of stroke, little is known about the cellular mechanisms by which it confers protection during the early stages of ischemia. Here, using a rat model of permanent middle cerebral artery occlusion (MCAO), we demonstrated that administration of LA 30 min prior to stroke, reduces infarct volume in a dose dependent manner. Whole-cell patch clamp Show moreLipoic acid (LA) is a naturally occurring compound and dietary supplement with powerful antioxidant properties. Although LA is neuroprotective in models of stroke, little is known about the cellular mechanisms by which it confers protection during the early stages of ischemia. Here, using a rat model of permanent middle cerebral artery occlusion (MCAO), we demonstrated that administration of LA 30 min prior to stroke, reduces infarct volume in a dose dependent manner. Whole-cell patch clamp ...
Protection against focal ischemic injury Special edition Journal of Neurosurgery podcast. Manuscript editor Anne Stanford speaks with Dr. Kevin Lee of the University of Virginia in Charlottesville. They discuss trans-sodium crocetinate and its neuroprotective effects as demonstrated in an animal model of cerebral ischemia and about brain ischemic injury in general.
Our results for diabetes duration are consistent with prior research conducted within a general population of patients, which found an increased rate of ischemic stroke as duration increased compared with nondiabetic patients (9,10). However, our results for HbA1c in diabetic patients with AF are not consistent with prior research conducted in diabetic patients in general. In our study, increased HbA1c did not have a substantial effect on the rate of ischemic stroke, whereas elevated HbA1c was significantly associated with ischemic stroke in predominantly non-AF populations (11-13). A possible reason for HbA1c having no association with ischemic stroke in diabetic patients with AF is the difference in the primary mechanism for stroke in diabetic patients with and without AF. Among patients with diabetes without AF, stroke is often due to underlying atherosclerosis (22,23). This mechanism may not be as important among diabetic patients with AF, because the primary mechanism for ischemic stroke is ...
Recurrent strokes make up almost 25% of the nearly 800,000 strokes that occur annually in the United States. Risk factors for ischemic stroke include hypertension, diabetes mellitus, hyperlipidemia, sleep apnea, and obesity. Lifestyle modifications, including tobacco cessation, decreased alcohol use, and increased physical activity, are also important in the management of patients with a history of stroke or transient ischemic attack. Antiplatelet therapy is recommended to reduce the risk of recurrent ischemic stroke. The selection of antiplatelet therapy should be based on timing, safety, effectiveness, cost, patient characteristics, and patient preference. Aspirin is recommended as initial treatment to prevent recurrent ischemic stroke. Clopidogrel is recommended as an alternative monotherapy and in patients allergic to aspirin. The combination of clopidogrel and aspirin is not recommended for long-term use (more than two to three years) because of increased bleeding risk. Aspirin/dipyridamole is at
Oxidative stress induced cell injury is reported to contribute to the pathogenesis of cerebral ischemia. Reactive oxygen species such as hydrogen peroxide (H2O2) and superoxide radical along with nitric oxide and peroxynitrite generated during ischemia-reperfusion injury, causes the overactivation of poly (ADP-ribose) polymerase (PARP) leading to neuronal cell death. In the present study we have evaluated the effects of PARP inhibitor, 8-hydroxy-2 methyl-quinazolin-4-[3H]one (NU1025) in H2O2 and 3-morphilinosyndonimine (SIN-1) induced cytotoxicity in PC12 cells as well as in middle cerebral artery occlusion (MCAO) induced focal cerebral ischemia in rats. Exposure of PC12 cells to H2O2 (0.4 mM) and SIN-1 (0.8 mM) resulted in a significant decrease in cell viability after 6 h. Pretreatment with NU1025 (0.2 mM) restored cell viability to approximately 73 and 82% in H2O2 and SIN-1 injured cells, respectively. In MCAO studies, NU1025 was administered at different time points (1 h before reperfusion, ...
Carbamylerythropoietin (CEPO) does not bind to the classical erythropoietin (EPO) receptor. Nevertheless, similarly to EPO, CEPO promotes neuroprotection on the histologic level in short-term stroke models. In the present study, we investigated whether CEPO and other nonerythropoietic EPO analogs could enhance functional recovery and promote long-term histologic protection after experimental focal cerebral ischemia. Rats were treated with the compounds after focal cerebral ischemia. Animals survived 1, 7, or 60 days and underwent behavioral testing (sensorimotor and foot-fault tests). Brain sections were stained and analyzed for Iba-1, myeloperoxidase, Tau-1, CD68 (ED1), glial fibrillary acidic protein (GFAP), Fluoro-Jade B staining, and overall infarct volumes. Treatment with CEPO reduced perifocal microglial activation (P, 0.05), polymorphomonuclear cell infiltration (P, 0.05), and white matter damage (P , 0.01) at 1 day after occlusion. Carbamylerythropoietin- treated rats showed better ...
Nitroxyl (HNO) donor compounds function as potent vasorelaxants, improve myocardial contractility and reduce ischemia-reperfusion injury in the cardiovascular system. With respect to the nervous system, HNO donors have been shown to attenuate NMDA receptor activity and neuronal injury, suggesting that its production may be protective against cerebral ischemic damage. Hence, we studied the effect of the classical HNO-donor, Angelis salt (AS), on a cerebral ischemia/reperfusion injury in a mouse model of experimental stroke and on related in vitro paradigms of neurotoxicity. I.p. injection of AS (40 mumol/kg) in mice prior to middle cerebral artery occlusion exacerbated cortical infarct size and worsened the persistent neurological deficit. AS not only decreased systolic blood pressure, but also induced systemic oxidative stress in vivo indicated by increased isoprostane levels in urine and serum. In vitro, neuronal damage induced by oxygen-glucose-deprivation of mature neuronal cultures was exacerbated
TY - JOUR. T1 - Delayed transplantation of human neural precursor cells improves outcome from focal cerebral ischemia in aged rats. AU - Jin, Kunlin. AU - Mao, Xiao Ou. AU - Xie, Lin. AU - Greenberg, Rose B.. AU - Peng, Botao. AU - Moore, Alexander. AU - Greenberg, Maeve B.. AU - Greenberg, David A.. PY - 2010/12. Y1 - 2010/12. N2 - Neural precursor cell (NPC) transplantation may have a role in restoring brain function after stroke, but how aging might affect the brains receptivity to such transplants is unknown. We reported previously that transplantation of human embryonic stem cell (hESC)-derived NPCs together with biomaterial (Matrigel) scaffolding into the brains of young adult Sprague-Dawley rats 3-weeks after distal middle cerebral artery occlusion (MCAO) reduced infarct volume and improved neurobehavioral performance. In this study, we compared the effect of NPC and Matrigel transplants in young adult (3-month-old) and aged (24-month-old) Fisher 344 rats from the National Institute on ...