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Endovascular mechanical thrombectomy, combined with a tissue plasminogen activator (t-PA), is efficacious as a standard care for qualifying ischemic stroke patients. However, > 50% of thrombectomy patients still have poor outcomes. Manganese porphyrins, commonly known as mimics of superoxide dismutases, are potent redox-active catalytic compounds that decrease oxidative/nitrosative stress and in turn decrease inflammatory responses, mitigating therefore the secondary injury of the ischemic brain. This study investigates the effect of intracarotid MnTnBuOE-2-PyP5+ (BMX-001) administration on long-term, 28-day post-stroke recovery in a clinically relevant setting. The 90 min of transient middle cerebral artery occlusion was performed in young, aged, male, female, and spontaneous hypertension rats. All physiological parameters, including blood pressure, blood gas, glucose, and temperature, were well controlled during ischemia. Either BMX-001 or a vehicle solution was infused through the carotid artery immediately after the removal of filament, mimicking endovascular thrombectomy, and was followed by 7 days of subcutaneous injection. Neurologic deficits and infarct volume were assessed at 28 days in a blinded manner. The effects of BMX-001 on the carotid arterial wall and blood-brain barrier permeability and its interaction with t-PA were assessed in normal rats. There were no intra-group differences in physiological variables. BMX-001-treated stroke rats regained body weight earlier, performed better in behavioral tests, and had smaller brain infarct size compared to the vehicle-treated group. No vascular wall damage and blood-brain barrier permeability changes were detected after the BMX-001 infusion. There was no drug interaction between BMX-001 and t-PA. Intracarotid BMX-001 infusion was safe, and it significantly improved stroke outcomes in rats. These findings indicate that BMX-001 is a candidate drug as an adjunct treatment for thrombectomy procedure to further improve the neurologic outcomes of thrombectomy patients. This study warrants further clinical investigation of BMX-001 as a new stroke therapy.
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BACKGROUND: An increase in sirtuin 1 (SIRT1) reportedly attenuates early brain injury, delayed cerebral ischemia, and short-term neurologic deficits in rodent models of subarachnoid hemorrhage (SAH). This study investigates the effect of resveratrol, a SIRT1 activator, on long-term functional recovery in a clinically relevant rat model of SAH. METHODS: Thirty male Wistar rats were subjected to fresh arterial blood injection into the prechiasmatic space and randomized to receive 7 days of intraperitoneal resveratrol (20 mg/kg) or vehicle injections. Body weight and rotarod performance were measured on days 0, 3, 7, and 34 post SAH. The neurologic score was assessed 7 and 34 days post SAH. Morris water maze performance was evaluated 29-33 days post SAH. Brain SIRT1 activity and CA1 neuronal survival were also assessed. RESULTS: Blood pressure rapidly increased in all SAH rats, and no between-group differences in blood pressure, blood gases, or glucose were detected. SAH induced weight loss during the first 7 days, which gradually recovered in both groups. Neurologic score and rotarod performance were significantly improved after resveratrol treatment at 34 days post SAH (p = 0.01 and 0.04, respectively). Latency to find the Morris water maze hidden platform was shortened (p = 0.02). In the resveratrol group, more CA1 neurons survived following SAH (p = 0.1). An increase in brain SIRT1 activity was confirmed in the resveratrol group (p < 0.05). CONCLUSIONS: Treatment with resveratrol for 1 week significantly improved the neurologic score, rotarod performance, and latency to find the Morris water maze hidden platform 34 days post SAH. These findings indicate that SIRT1 activation warrants further investigation as a mechanistic target for SAH therapy.
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Lesiones Encefálicas , Hemorragia Subaracnoidea , Animales , Masculino , Ratas , Modelos Animales de Enfermedad , Ratas Wistar , Resveratrol/farmacología , Sirtuina 1 , Hemorragia Subaracnoidea/tratamiento farmacológicoRESUMEN
Introduction Cardiac arrest (CA) and resuscitation induces global cerebral ischemia and reperfusion, causing neurologic deficits or death. Manganese porphyrins, superoxide dismutase mimics, are reportedly able to effectively reduce ischemic injury in brain, kidney, and other tissues. This study evaluates the efficacy of a third generation lipophilic Mn porphyrin, MnTnBuOE-2-PyP5+, Mn(III) ortho meso-tetrakis (N-n-butoxyethylpyridinium-2-yl)porphyrin (MnBuOE, BMX-001), in both mouse and rat models of CA. Methods Forty-eight animals were subjected to 8 min of CA and resuscitated subsequently by chest compression and epinephrine infusion. Vehicle or MnBuOE was given immediately after resuscitation followed by daily subcutaneous injections. Body weight, spontaneous activity, neurologic deficits, rotarod performance, and neuronal death were assessed. Kidney tubular injury was assessed in CA mice. Data were collected by the investigators who were blinded to the treatment groups. Results Vehicle mice had a mortality of 20%, which was reduced by 50% by MnBuOE. All CA mice had body weight loss, spontaneous activity decline, neurologic deficits, and decreased rotarod performance that were significantly improved at three days post MnBuOE daily treatment. MnBuOE treatment reduced cortical neuronal death and kidney tubular injury in mice (p < 0.05) but not hippocampus neuronal death (23% MnBuOE vs. 34% vehicle group, p = 0.49). In rats, they had a better body-weight recovery and increased rotarod latency after MnBuOE treatment when compared to vehicle group (p < 0.01 vs. vehicle). MnBuOE-treated rats had a low percentage of hippocampus neuronal death (39% MnBuOE vs. 49% vehicle group, p = 0.21) and less tubular injury (p < 0.05) relative to vehicle group. Conclusions We demonstrated the ability of MnBuOE to improve post-CA survival, as well as functional outcomes in both mice and rats, which jointly account for the improvement not only of brain function but also of the overall wellbeing of the animals. While MnBuOE bears therapeutic potential for treating CA patients, the females and the animals with comorbidities must be further evaluated before advancing toward clinical trials.
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Failure to translate promising potential therapeutics for intracerebral hemorrhage (ICH) partially results from limited understanding of cellular mechanisms underlying brain injury and repair. Understanding neural repair mechanisms after brain injury requires intricate comprehension of microglial behavior; however, studying individual microglial cell behavior is challenging. Further single cell isolation techniques may be an excellent means to expand known differences in male and female microglial cell response to ICH. In this study, 24 h after intrastriatal collagenase injection, one male and one female CX3CR1-GFP mouse underwent ex vivo microglial cell isolation via micropipette from perihematomal regions and equivalent location of contralateral striata. After cell collection, individual and grouped cell samples underwent reverse transcription and analyses for gene expression using Fluidigm RT-PCR technology. Data were analyzed by t-tests and visualized as a heatmap of the log2 Ct values. Gene expression assays were chosen for target-specific amplification, including markers of M1 pro-inflammatory microglial phenotype (i.e., Tnf, Il6, Fcgr3/CD16), M2 anti-inflammatory markers (i.e., Mrc1/CD206, Arg1, Tgfb1), and genes involved in the toll-like receptor pathway (i.e., Tlr2, Tlr4 and Myd88). Greater number of individual microglia cells expressed Mcr1, Tlr2, and Arg1 in perihematomal tissue than in contralateral hemispheres. Additionally, more male microglia expressed Myd88, Tlr2, Il6, and Arg1 than did female microglia. Single cell microglial isolation is feasible after in vivo rodent ICH. Differential gene expression can be detected between individual cells from different brain regions and experimental conditions. Cell-specific analyses will contribute to improved understanding of microglial roles in both post-ICH pathogenesis and recovery.
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Lesiones Encefálicas , Microglía , Animales , Lesiones Encefálicas/metabolismo , Separación Celular , Hemorragia Cerebral/metabolismo , Femenino , Interleucina-6/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Microglía/metabolismo , Factor 88 de Diferenciación Mieloide/metabolismo , Receptor Toll-Like 2RESUMEN
Ischemic stroke in rodents is usually induced by intraluminal occlusion of the middle cerebral artery (MCA) via the external carotid artery (ECA) or the common carotid artery (CCA). The latter route requires permanent CCA occlusion after ischemia, and here, we assess its effects on long-term outcomes. Transient occlusion of MCA and CCA was performed at normal body temperature. After 90 min of ischemia, mice were randomized to permanent CCA occlusion or no occlusion (control group). Body weight, and motor and sensory functions, ie, pole test, adhesive tape removal, and elevated plus maze, were evaluated at 24 h, and at 7 and 28 days after stroke. Infarct volume, apoptosis, and activation of astrocytes and microglia were assessed at 4 weeks by an investigator blinded to groups. The Morris water maze test was performed at 3 weeks in the second experiment. One mouse died at 4 days, and the other mice survived with persistent neurologic deficits. CCA-occluded mice exhibited delayed turn on the pole at 24 h and decreased responses to the von Frey filament, and spent more time on the pole at 7 and 28 days than the control group. Infarction, hemispheric atrophy, glial activation, and apoptotic neuronal death were present in all mice, and no intra-group difference was found. However, CCA-occluded mice had a significantly poorer performance in the Morris water maze compared to the control group, which showed an adverse effect of post-ischemia CCA occlusion on cognition. Thus, the model selection should be well considered in preclinical efficacy studies on stroke-induced vascular dementia and stroke with Alzheimer's disease.
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Isquemia Encefálica , Accidente Cerebrovascular , Amnesia , Animales , Arteria Carótida Común , Modelos Animales de Enfermedad , Infarto de la Arteria Cerebral Media , Isquemia , RatonesRESUMEN
BACKGROUND: Cerebral ischemia and reperfusion (I/R) induces oxidative stress and activates autophagy, leading to brain injury and neurologic deficits. Cervical vagus nerve stimulation (VNS) increases cerebral blood flow (CBF). In this study, we investigate the effect of VNS-induced CBF increase on neurologic outcomes after cardiac arrest (CA). MATERIALS AND METHODS: A total of 40 male C57Bl/6 mice were subjected to ten minutes of asphyxia CA and randomized to vagus nerve isolation (VNI) or VNS treatment group. Eight mice received sham surgery and VNI. Immediately after resuscitation, 20 minutes of electrical stimulation (1 mA, 1 ms, and 10 Hz) was started in the VNS group. Electrocardiogram, blood pressure, and CBF were monitored. Neurologic and histologic outcomes were evaluated at 72 hours. Oxidative stress and autophagy were assessed at 3 hours and 24 hours after CA. RESULTS: Baseline characteristics were not different among groups. VNS mice had better behavioral performance (ie, open field, rotarod, and neurologic score) and less neuronal death (p < 0.05, vs VNI) in the hippocampus. CBF was significantly increased in VNS-treated mice at 20 minutes after return of spontaneous circulation (ROSC) (p < 0.05). Furthermore, levels of 8-hydroxy-2'-deoxyguanosine in the blood and autophagy-related proteins (ie, LC-3â ¡/â , Beclin-1, and p62) in the brain were significantly decreased in VNS mice. Aconitase activity was also reduced, and the p-mTOR/mTOR ratio was increased in VNS mice. CONCLUSIONS: Oxidative stress induced by global brain I/R following CA/ROSC leads to early excessive autophagy and impaired autophagic flux. VNS promoted CBF recovery, ameliorating these changes. Neurologic and histologic outcomes were also improved.
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Paro Cardíaco , Estimulación del Nervio Vago , Animales , Humanos , Masculino , Ratones , Autofagia , Paro Cardíaco/terapia , Estrés Oxidativo , Serina-Treonina Quinasas TOR , Nervio VagoRESUMEN
David Warner, M.D., and Michael Todd, M.D., first met in 1985. They began working together at the University of Iowa (Iowa City, Iowa) a year later with a shared interest in both laboratory and clinical neuroscience-and in the operative care of neurosurgical patients. That collaboration has now lasted for 35 yr, resulting in more than 70 joint publications. More importantly, they have had the privilege of working together with close to 1,000 colleagues from around the world, in a dozen medical specialties. Their careers are an example of what can be accomplished by friendship, mutual commitment, persistence, and a willingness to join with others.
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Anestesia/historia , Amigos , Colaboración Intersectorial , Neurocirujanos/historia , Historia del Siglo XX , Historia del Siglo XXI , Humanos , MasculinoRESUMEN
A video (video 1) describing a novel murine endovascular embolic stroke model is presented. Traditional middle cerebral artery (MCA) occlusion models include a blind insertion of a monofilament string1 2 into the common or external carotid artery with the expectation to selectively occlude the MCA. However, significant mortality occurs due to subarachnoid hemorrhage and variability in stroke size, possibly related to the filament's malposition-for example, external carotid or proximal internal carotid artery (ICA). Additionally, while the string is in place, it occludes the entire extracranial ICA affecting also the collateral pial circulation. neurintsurg;14/4/413/V1F1V1Video 1 Our model includes tail artery access, which tolerates several procedures facilitating survival studies. This model uses autologous blood3 4 clot deployed directly into the MCA, resembling what occurs in clinical practice. Autologous thrombi could be lysed with IA/IV tissue plasminogen activator.In summary, we describe a novel model that resembles real practice, permits multiple catheterizations, results in reliable embolization under fluoroscopic guidance and allows therapeutic interventions not available with traditional models.
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Accidente Cerebrovascular Embólico , Procedimientos Endovasculares , Animales , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/cirugía , Modelos Animales de Enfermedad , Accidente Cerebrovascular Embólico/diagnóstico por imagen , Accidente Cerebrovascular Embólico/cirugía , Procedimientos Endovasculares/métodos , Humanos , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Infarto de la Arteria Cerebral Media/cirugía , Ratones , Arteria Cerebral Media/diagnóstico por imagen , Activador de Tejido Plasminógeno/uso terapéuticoRESUMEN
Background Animal disease models represent the cornerstone in basic cardiac arrest (CA) research. However, current experimental models of CA and resuscitation in mice are limited. In this study, we aimed to develop a mouse model of asphyxial CA followed by cardiopulmonary resuscitation (CPR), and to characterize the immune response after asphyxial CA/CPR. Methods and Results CA was induced in mice by switching from an O2/N2 mixture to 100% N2 gas for mechanical ventilation under anesthesia. Real-time measurements of blood pressure, brain tissue oxygen, cerebral blood flow, and ECG confirmed asphyxia and ensuing CA. After a defined CA period, mice were resuscitated with intravenous epinephrine administration and chest compression. We subjected young adult and aged mice to this model, and found that after CA/CPR, mice from both groups exhibited significant neurologic deficits compared with sham mice. Analysis of post-CA brain confirmed neuroinflammation. Detailed characterization of the post-CA immune response in the peripheral organs of both young adult and aged mice revealed that at the subacute phase following asphyxial CA/CPR, the immune system was markedly suppressed as manifested by drastic atrophy of the spleen and thymus, and profound lymphopenia. Finally, our data showed that post-CA systemic lymphopenia was accompanied with impaired T and B lymphopoiesis in the thymus and bone marrow, respectively. Conclusions In this study, we established a novel validated asphyxial CA model in mice. Using this new model, we further demonstrated that asphyxial CA/CPR markedly affects both the nervous and immune systems, and notably impairs lymphopoiesis of T and B cells.
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Asfixia/complicaciones , Paro Cardíaco/etiología , Inmunidad Celular , Linfocitos/inmunología , Linfopoyesis/fisiología , Resucitación/efectos adversos , Animales , Asfixia/inmunología , Modelos Animales de Enfermedad , Paro Cardíaco/diagnóstico , Paro Cardíaco/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Índice de Severidad de la EnfermedadRESUMEN
Spliced X-box binding protein-1 (XBP1s) together with the hexosamine biosynthetic pathway (HBP) and O-GlcNAcylation forms the XBP1s/HBP/O-GlcNAc axis. Our previous studies have provided evidence that activation of this axis is neuroprotective after ischemic stroke and critically, ischemia-induced O-GlcNAcylation is impaired in the aged brain. However, the XBP1s' neuroprotective role and its link to O-GlcNAcylation in stroke, as well as the therapeutic potential of targeting this axis in stroke, have not been well established. Moreover, the mechanisms underlying this age-related impairment of O-GlcNAcylation induction after brain ischemia remain completely unknown. In this study, using transient ischemic stroke models, we first demonstrated that neuron-specific overexpression of Xbp1s improved outcome, and pharmacologically boosting O-GlcNAcylation with thiamet-G reversed worse outcome observed in neuron-specific Xbp1 knockout mice. We further showed that thiamet-G treatment improved long-term functional recovery in both young and aged animals after transient ischemic stroke. Mechanistically, using an analytic approach developed here, we discovered that availability of UDP-GlcNAc was compromised in the aged brain, which may constitute a novel mechanism responsible for the impaired O-GlcNAcylation activation in the aged brain after ischemia. Finally, based on this new mechanistic finding, we evaluated and confirmed the therapeutic effects of glucosamine treatment in young and aged animals using both transient and permanent stroke models. Our data together support that increasing O-GlcNAcylation is a promising strategy in stroke therapy.
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Isquemia Encefálica/metabolismo , Isquemia Encefálica/prevención & control , Encéfalo/metabolismo , Accidente Cerebrovascular Isquémico/metabolismo , Accidente Cerebrovascular Isquémico/prevención & control , Neuroprotección/fisiología , Factores de Edad , Animales , Encéfalo/efectos de los fármacos , Glucosamina/farmacología , Glucosamina/uso terapéutico , Glicosilación , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Ratas , Ratas Endogámicas F344 , Proteína 1 de Unión a la X-Box/deficiencia , Proteína 1 de Unión a la X-Box/genéticaRESUMEN
Mn(III) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin, (H2O)MnTnHex-2-PyP5+ (MnHex) carrying long hexyl chains, is a lipophilic mimic of superoxide dismutase (SOD) and a redox-active drug candidate. MnHex crosses the blood-brain barrier, and improved neurologic outcome and decreased infarct size and inflammation in a rat middle cerebral artery occlusion (MCAO) ischemic stroke model. Yet, the dose and the therapeutic efficacy of Mn porphyrin were limited by an adverse effect of arterial hypotension. An equally lipophilic Fe analog, (OH)FeTnHex-2-PyP4+ (FeHex), is as redox-active and potent SOD mimic in vitro. With different coordination geometry of the metal site, FeHex has one hydroxo (OH) ligand (instead of water) bound to the Fe center in the axial position. It has ~2 orders of magnitude higher efficacy than MnHex in an SOD-deficient E. coli model of oxidative stress. In vivo, it does not cause arterial hypotension and is less toxic to mice. We thus evaluated FeHex versus MnHex in a rodent MCAO model. We first performed short- and long-term pharmacokinetics (PK) of both porphyrins in the plasma, brain, and liver of rats and mice. Given that damage to the brain during stroke occurs very rapidly, fast delivery of a sufficient dose of drug is important. Therefore, we aimed to demonstrate if, and how fast after reperfusion, Fe porphyrin reaches the brain relative to the Mn analog. A markedly different plasma half-life was found with FeHex (~23 h) than with MnHex (~1.4 h), which resulted in a more than 2-fold higher plasma exposure (AUC) in a 7-day twice-daily treatment of rats. The increased plasma half-life is explained by the much lower liver retention of FeHex than typically found in Mn analogs. In the brain, a 3-day mouse PK study showed similar levels of MnHex and FeHex. The same result was obtained in a 7-day rat PK study, despite the higher plasma exposure of FeHex. Importantly, in a short-term PK study with treatment starting 2 h post MCAO, both Fe- and Mn- analogs distributed at a higher level to the injured brain hemisphere, with a more pronounced effect observed with FeHex. While a 3-day mouse MCAO study suggested the efficacy of Fe porphyrin, in a 7-day rat MCAO study, Mn-, but not Fe porphyrin, was efficacious. The observed lack of FeHex efficacy was discussed in terms of significant differences in the chemistry of Fe vs the Mn center of metalloporphyrin; relative to MnHex, FeHex has the propensity for axial coordination, which in vivo would preclude the reactivity of the Fe center towards small reactive species.
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OBJECTIVES: We tested the hypothesis that prolonged inhalation of 70% argon for 24 hours after in vivo permanent or temporary stroke provides neuroprotection and improves neurologic outcome and overall recovery after 7 days. DESIGN: Controlled, randomized, double-blinded laboratory study. SETTING: Animal research laboratories. SUBJECTS: Adult Wistar male rats (n = 110). INTERVENTIONS: Rats were subjected to permanent or temporary focal cerebral ischemia via middle cerebral artery occlusion, followed by inhalation of 70% argon or nitrogen in 30% oxygen for 24 hours. On postoperative day 7, a 48-point neuroscore and histologic lesion size were assessed. MEASUREMENTS AND MAIN RESULTS: After argon inhalation for 24 hours immediately following "severe permanent ischemia" induction, neurologic outcome (neuroscore, p = 0.034), overall recovery (body weight, p = 0.02), and infarct volume (total infarct volume, p = 0.0001; cortical infarct volume, p = 0.0003; subcortical infarct volume, p = 0.0001) were significantly improved. When 24-hour argon treatment was delayed for 2 hours after permanent stroke induction or until after postischemic reperfusion treatment, neurologic outcomes remained significantly improved (neuroscore, p = 0.043 and p = 0.014, respectively), as was overall recovery (body weight, p = 0.015), compared with nitrogen treatment. However, infarct volume and 7-day mortality were not significantly reduced when argon treatment was delayed. CONCLUSIONS: Neurologic outcome (neuroscore), overall recovery (body weight), and infarct volumes were significantly improved after 24-hour inhalation of 70% argon administered immediately after severe permanent stroke induction. Neurologic outcome and overall recovery were also significantly improved even when argon treatment was delayed for 2 hours or until after reperfusion.
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Argón/farmacología , Isquemia Encefálica/terapia , Neuroprotección/fisiología , Fármacos Neuroprotectores/farmacología , Animales , Isquemia Encefálica/prevención & control , Modelos Animales de Enfermedad , Masculino , Distribución Aleatoria , Ratas , Ratas WistarAsunto(s)
Lesiones Traumáticas del Encéfalo , Fármacos Neuroprotectores , Animales , Cognición , Ratones , XenónRESUMEN
Sex dimorphism has been demonstrated after experimental intracerebral hemorrhage (ICH). Decreased mortality and improved neurobehavioral outcomes occur in female compared to male mice after intrastriatal autologous blood or collagenase injection. Sex-specific differences in post-ICH gene and protein expression may provide mechanistic insight into this phenomenon. Ten- to 12-week-old C57BL/6 male (M) and female in high estrous state (HE-F) underwent left intrastriatal collagenase injection. We assessed neurobehavioral outcomes over the first 30 days, hematoma volume and cerebral edema evolution over the first 24 h, and transcriptomic gene and protein expression at pre-selected time points during the acute phase of injury. Genome-wide expression profiling was performed with Affymetrix GeneChip Mouse Genome 2.0 Probes, and proteomics analyses were performed using mass spectroscopy. Sex does not affect hemorrhage evolution, but female sex is associated with improved neurobehavioral recovery after ICH. A total of 7037 probes qualified for our filtering criteria, representing 5382 mapped genes and 256 unmapped genes. Female-unique pathways involved cell development, growth, and proliferation, while male-unique pathways involved molecular degradation. At 6 and 24 h post-ICH, differential expression was observed in 850 proteins vs baseline in males, 608 proteins vs baseline in females, and 1 protein in females vs males. Female sex is associated with improved neurobehavioral recovery, and differential gene and protein expression after intrastriatal collagenase injection.
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Hemorragia Cerebral/genética , Hemorragia Cerebral/metabolismo , Regulación de la Expresión Génica/fisiología , Caracteres Sexuales , Animales , Edema Encefálico/diagnóstico por imagen , Edema Encefálico/etiología , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/fisiopatología , Modelos Animales de Enfermedad , Femenino , Imagen por Resonancia Magnética , Masculino , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Endogámicos C57BL , Actividad Motora , Proteómica , ARN Mensajero/metabolismo , Transducción de Señal/fisiología , Factores de TiempoRESUMEN
Experimental cardiac arrest (CA) in aging research is infrequently studied in part due to the limitation of animal models. We aimed to develop an easily performed mouse CA model to meet this need. A standard mouse KCl-induced CA model using chest compressions and intravenous epinephrine for resuscitation was modified by blood withdrawal prior to CA onset, so as to decrease the requisite KCl dose to induce CA by decreasing the circulating blood volume. The modification was then compared to the standard model in young adult mice subjected to 8 min CA. 22-month old mice were then subjected to 8 min CA, resuscitated, and compared to young adult mice. Post-CA functional recovery was evaluated by measuring spontaneous locomotor activity pre-injury, and on post-CA days 1, 2, and 3. Neurological score and brain histology were examined on day 3. Brain elF2α phosphorylation levels were measured at 1 h to verify tissue stress. Compared to the standard model, the modification decreased cardiopulmonary resuscitation duration and increased 3-day survival in young mice. For aged mice, survival was 100 % at 24 h and 54% at 72 h. Neurological deficit was present 3 days post-CA, although more severe versus young mice. Mild neuronal necrosis was present in the cortex and hippocampus. The modified model markedly induced elF2α phosphorylation in both age groups. This modified procedure makes the CA model feasible in aged mice and provides a practical platform for understanding injury mechanisms and developing therapeutics for elderly patients.
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INTRODUCTION: Aside from direct effects on neurotransmission, inhaled and intravenous anesthetics have immunomodulatory properties. In vitro and mouse model studies suggest that propofol inhibits, while isoflurane increases, neuroinflammation. If these findings translate to humans, they could be clinically important since neuroinflammation has detrimental effects on neurocognitive function in numerous disease states. MATERIALS AND METHODS: To examine whether propofol and isoflurane differentially modulate neuroinflammation in humans, cytokines were measured in a secondary analysis of cerebrospinal fluid (CSF) samples from patients prospectively randomized to receive anesthetic maintenance with propofol vs. isoflurane (registered with http://www.clinicaltrials.gov, identifier NCT01640275). We measured CSF levels of EGF, eotaxin, G-CSF, GM-CSF, IFN-α2, IL-1RA, IL-6, IL-7, IL-8, IL-10, IP-10, MCP-1, MIP-1α, MIP-1ß, and TNF-α before and 24 h after intracranial surgery in these study patients. RESULTS: After Bonferroni correction for multiple comparisons, we found significant increases from before to 24 h after surgery in G-CSF, IL-10, IL-1RA, IL-6, IL-8, IP-10, MCP-1, MIP-1α, MIP-1ß, and TNF-α. However, we found no difference in cytokine levels at baseline or 24 h after surgery between propofol- (n = 19) and isoflurane-treated (n = 21) patients (p > 0.05 for all comparisons). Increases in CSF IL-6, IL-8, IP-10, and MCP-1 levels directly correlated with each other and with postoperative CSF elevations in tau, a neural injury biomarker. We observed CSF cytokine increases up to 10-fold higher after intracranial surgery than previously reported after other types of surgery. DISCUSSION: These data clarify the magnitude of neuroinflammation after intracranial surgery, and raise the possibility that a coordinated neuroinflammatory response may play a role in neural injury after surgery.
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BACKGROUND: Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning. METHODS: An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details. RESULTS: The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture. CONCLUSIONS: The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.
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Investigación Biomédica/normas , Reanimación Cardiopulmonar/normas , Ahogamiento , Paro Cardíaco/terapia , Proyectos de Investigación/normas , Consenso , Ahogamiento/mortalidad , Paro Cardíaco/diagnóstico , Paro Cardíaco/etiología , Paro Cardíaco/mortalidad , Humanos , Comunicación Interdisciplinaria , Cooperación InternacionalRESUMEN
BACKGROUND: Utstein-style guidelines use an established consensus process, endorsed by the international resuscitation community, to facilitate and structure resuscitation research and publication. The first "Guidelines for Uniform Reporting of Data From Drowning" were published over a decade ago. During the intervening years, resuscitation science has advanced considerably, thus making revision of the guidelines timely. In particular, measurement of cardiopulmonary resuscitation elements and neurological outcomes reporting have advanced substantially. The purpose of this report is to provide updated guidelines for reporting data from studies of resuscitation from drowning. METHODS: An international group with scientific expertise in the fields of drowning research, resuscitation research, emergency medical services, public health, and development of guidelines met in Potsdam, Germany, to determine the data that should be reported in scientific articles on the subject of resuscitation from drowning. At the Utstein-style meeting, participants discussed data elements in detail, defined the data, determined data priority, and decided how data should be reported, including scoring methods and category details. RESULTS: The template for reporting data from drowning research was revised extensively, with new emphasis on measurement of quality of resuscitation, neurological outcomes, and deletion of data that have proved to be less relevant or difficult to capture. CONCLUSIONS: The report describes the consensus process, rationale for selecting data elements to be reported, definitions and priority of data, and scoring methods. These guidelines are intended to improve the clarity of scientific communication and the comparability of scientific investigations.
Asunto(s)
Reanimación Cardiopulmonar/normas , Ahogamiento , Paro Cardíaco/terapia , Consenso , Servicios Médicos de Urgencia/normas , Paro Cardíaco/diagnóstico , Paro Cardíaco/etiología , Paro Cardíaco/mortalidad , Humanos , Cooperación InternacionalRESUMEN
BACKGROUND AND PURPOSE: Impaired protein homeostasis induced by endoplasmic reticulum dysfunction is a key feature of a variety of age-related brain diseases including stroke. To restore endoplasmic reticulum function impaired by stress, the unfolded protein response is activated. A key unfolded protein response prosurvival pathway is controlled by the endoplasmic reticulum stress sensor (inositol-requiring enzyme-1), XBP1 (downstream X-box-binding protein-1), and O-GlcNAc (O-linked ß-N-acetylglucosamine) modification of proteins (O-GlcNAcylation). Stroke impairs endoplasmic reticulum function, which activates unfolded protein response. The rationale of this study was to explore the potentials of the IRE1/XBP1/O-GlcNAc axis as a target for neuroprotection in ischemic stroke. METHODS: Mice with Xbp1 loss and gain of function in neurons were generated. Stroke was induced by transient or permanent occlusion of the middle cerebral artery in young and aged mice. Thiamet-G was used to increase O-GlcNAcylation. RESULTS: Deletion of Xbp1 worsened outcome after transient and permanent middle cerebral artery occlusion. After stroke, O-GlcNAcylation was activated in neurons of the stroke penumbra in young mice, which was largely Xbp1 dependent. This activation of O-GlcNAcylation was impaired in aged mice. Pharmacological increase of O-GlcNAcylation before or after stroke improved outcome in both young and aged mice. CONCLUSIONS: Our study indicates a critical role for the IRE1/XBP1 unfolded protein response branch in stroke outcome. O-GlcNAcylation is a prosurvival pathway that is activated in the stroke penumbra in young mice but impaired in aged mice. Boosting prosurvival pathways to counterbalance the age-related decline in the brain's self-healing capacity could be a promising strategy to improve ischemic stroke outcome in aged brains.