Abstract WP115: Transplanted Induced Neural Stem Cells Differentiate and Integrate Into the Brain Parenchyma of Ischemic Stroke Pigs Leading to Improved Tissue Recovery

Studies in rodents have provided evidence that induced pluripotent stem cell derived neural stem cells (iNSCs) have a multifunctional role in stroke recovery. iNSCs mitigate tissue loss due to secondary injury, promote tissue recovery through angiogenesis, and differentiate into mature neural cell types resulting in recovery and replacement of lost and damaged brain tissue. However, many stroke therapies developed in the rodent have failed in clinical trials, suggesting that iNSC therapy should be tested in a more translatable large animal model such as the pig. The objective of this study was to assess the ability of iNSCs to differentiate into mature neural cell types and characterize the effects of iNSCs on brain tissue recovery utilizing non-invasive magnetic resonance imaging (MRI) and spectroscopy approaches in a pig model. Eight male landrace pigs underwent middle cerebral artery occlusion stroke surgery. After 5 days, 4 pigs received iNSC intraparenchymal injections and 4 pigs received vehicle only injections. Pigs underwent MRI assessment at 24 hrs post-stroke and 1, 4, and 12 wks post-injection, and brain tissues were collected 12 wks post-injection. At 12 wks post-injection, iNSC treated pigs showed significant improvement in white matter integrity with recovery of fractional anisotropy being 4-fold higher in treated pigs relative to non-treated pigs. Perfusion weighted imaging demonstrated significant improvement in cerebral blood volume (13%), time to peak (36%), and mean transit time (41%) in treated pigs at 12 wks post-injection vs. non-treated pigs. In addition, treated pigs showed significant improvement in neurometabolites NAA, Cr, and Cho at 12 wks post-injection relative to non-treated pigs. Gene expression analysis established significant increases in neurotrophic and angiogenic factors including BDNF and ANG1, respectively, in brain tissue of treated pigs vs. non-treated pigs suggesting potential modes of action. iNSCs were located in the brain parenchyma 12 wks post-injection, and the majority were positive for the mature neuronal marker NeuN. These results demonstrated that iNSCs are capable of neuronal differentiation and long term integration while promoting tissue recovery in a preclinical pig ischemic stroke model.

Telemedicine Quality and Outcomes in Stroke: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

Telestroke is one of the most frequently used and rapidly expanding applications of telemedicine, delivering much-needed stroke expertise to hospitals and patients. This document reviews the current status of telestroke and suggests measures for ongoing quality and outcome monitoring to improve performance and to enhance delivery of care.

METHODS

A literature search was undertaken to examine the current status of telestroke and relevant quality indicators. The members of the writing committee contributed to the review of specific quality and outcome measures with specific suggestions for metrics in telestroke networks. The drafts were circulated and revised by all committee members, and suggestions were discussed for consensus.

RESULTS

Models of telestroke and the role of telestroke in stroke systems of care are reviewed. A brief description of the science of quality monitoring and prior experience in quality measures for stroke is provided. Process measures, outcomes, tissue-type plasminogen activator use, patient and provider satisfaction, and telestroke technology are reviewed, and suggestions are provided for quality metrics. Additional topics include licensing, credentialing, training, and documentation.

Rationale for ischemic conditioning to prevent stroke in patients with intracranial arterial stenosis

Intracranial atherosclerotic arterial stenosis (ICAS) is one of the most common causes of stroke worldwide and is associated with particularly a high risk of recurrent stroke. Although aggressive medical management, consisting of dual antiplatelet therapy and intensive control of vascular risk factors, has improved the prognosis of patients with ICAS, subgroups of patients remain at very high risk of stroke. More effective therapies for these high-risk patients are urgently needed. One promising treatment is remote limb ischemic conditioning, which involves producing repetitive, transient ischemia of a limb by inflating a blood pressure cuff with the intention of protecting the brain from subsequent ischemia. In this study, we review the limitations of currently available treatments, discuss the potential mechanisms of action of ischemic conditioning, describe the preclinical and clinical data suggesting a possible role of ischemic conditioning in treating patients with ICAS, and outline the questions that still need to be answered in future studies of ischemic conditioning in subjects with ICAS.

An analysis of business issues in a telestroke project

A telehealth network based at the Medical College of Georgia was established in 2003 to treat stroke patients in remote hospitals. In the first three years, more than 400 patients were evaluated at nine rural hospitals. A total of 65 patients (16%) were treated with tissue plasminogen activator (approximately half of them in less than 2 h). Although clinically successful, the system reached the point at which it would either further diffuse or die out. We examined the roles played by internal and external factors in the development of the system. We interviewed 25 individuals in five hospitals (the hub hospital and four rural hospitals). Important business issues were identified that would need to be addressed in order to expand the project and make it self-sustaining. The external factors were economic, legal and market issues. The internal factors were organizational, technical and educational issues. Early identification and negotiation of business issues related to project implementation are likely to be important in diffusion and sustainability.

Abstract 130: Induced Neural Stem Cell Treated Stroke Pigs Show Improved White Matter Integrity and Brain Metabolism Post-ischemic Stroke

Recent studies in rodent stroke models have shown that induced pluripotent stem cell derived neural stem cells (iNSCs) can lead to a significant decrease in lesion size, immune response and improvement in functional deficits. These improvements are linked to the iNSC potential dual mode of action as they can perform as a cell replacement therapy and produce neuroprotective and regenerative signaling. These results are promising yet the vast majority of therapies developed in rodent stroke models have failed to translate in clinical trials; suggesting that iNSC therapy should be tested in a more human like model such as the pig. We hypothesize that iNSC treatment will lead to improved white matter integrity, brain metabolism and cerebral blood flow (CBF) as determined by magnetic resonance imaging and spectroscopy (MRI and MRS) in stroked pigs. Eight male landrace pigs underwent middle cerebral artery occlusion stroke surgery. After 5 days, 4 pigs received iNSCs intraparenchymal injections and 4 pigs received vehicle only injections. Pigs underwent MRI and MRS assessment at 24 hrs post-injury and 1, 4 and 12 wks post-injection. MRI results at 24 hrs showed that all pigs had an ischemic stroke. At 1 wk post-injection, fractional anisotropy measurements of white matter integrity showed the affected side of the brain was 71% and 52% of normal, non-treated and treated respectively. At 12 wks, iNSC treated pigs showed a significant improvement in FA at 93% of normal, while non-treated pigs showed no improvement. MRS results demonstrated a significant decrease in NAA, Cr and Cho at 1 wk post-injection in treated and non-treated pigs. However, treated pigs showed a significant improvement in NAA, Cr and Cho at 12 wks post-injection, while non-treated pigs showed no improvement. At 12 wks, ischemic tissue in iNSC treated pigs had trending increases in CBF, while non-treated pigs showed no improvement. These results demonstrated that iNSC treated stroke pigs show improved white matter integrity, brain metabolism and CBF post-ischemic stroke and that iNSCs may one day be a viable clinical option for human stroke patients.

Abstract 177: Exploratory Results From the B01-02 Trial: Administration of MultiStem® Results in Decreased Circulating CD3+ Cells and Lower Levels of Inflammatory Cytokines

Introduction: B01-02 was a double-blind, placebo-controlled study of ischemic stroke patients (NIHSS 8-20, inclusive) treated within 24-48 hours of symptom onset with MultiStem, an adult, adherent, stem cell product. In pre-clinical models of stroke, MultiStem appears to confer improved neurological benefit through multiple mechanisms, including down-regulation of the peripheral immune response. We sought to determine whether this observation translated to acute ischemic stroke patients treated with MultiStem.

Methods: Patients were randomized 1:1 and received IV infusion of 1.2 billion cells or placebo. After randomization, patients had blood drawn to determine baseline levels of circulating levels of CD3+ cells or specific inflammatory cytokines. Blood was drawn again at days 2, 7 and 30 post-treatment to determine the average fold change from baseline in each patient at each time point.

Results: 126 patients formed the Intention-To-Treat (ITT) population, 65 receiving MultiStem, 61 placebo. 38 MultiStem patients and 40 placebo patient samples were analyzed for CD3+ cells, while 60 MultiStem patients and 55 placebo patients samples were analyzed for serum cytokine levels. CD3+ cell levels were significantly decreased in the MultiStem treatment group compared to placebo (p=0.001) at Day 2, but not later. IL-6 (p=.031) and IL-12 (p=.035) were both significantly downregulated in the MultiStem treatment group at Day 7. IL-1β (p=.065), TNF-α (p=.068) and IFN-γ (p=.100) also trended towards being significantly reduced at Day 7.

Conclusions: IV administration of MultiStem within 24-48 hours of an ischemic stroke results in decreased circulating CD3+ cells, while reducing inflammatory cytokines in the blood during the first 7 days after onset of symptoms. These results support the hypothesis that MultiStem treatment limits the activation of the innate immune system’s response to stroke, which may provide improved neurological and recovery outcomes. Additional studies are required to confirm this observation and optimize the time of administration for MultiStem mediated benefit

Abstract 71: Final Results of the B01-02 Phase 2 Trial Testing the Safety and Efficacy of MultiStem® in Treatment of Ischemic Stroke

Introduction: MultiStem is an adult, adherent, stem cell product, having shown safety and efficacy in other clinical indications and pre-clinical models of stroke. We assessed whether it was safe and improved outcomes in patients with ischemic stroke.

Methods: B01-02 was a double-blind, placebo-controlled study of ischemic stroke patients (NIHSS 8-20, inclusive) treated within 24-48 hours of symptoms at 33 sites in the U.S. and U.K. Patients were randomized 1:1 and received infusion of 1.2 billion cells or placebo. Efficacy endpoints included Global Recovery (mRS ≤2, NIHSS Δ ≥75% and BI ≥95) and Excellent Outcome between groups (mRS ≤1, NIHSS ≤1, BI ≥95) at Day 90, among others. Safety end points included neurologic worsening, secondary infections, adverse events and mortality.

Results: 126 patients formed the Intention-To-Treat (ITT) population, 65 receiving MultiStem, 61 placebo. The cell therapy did not show a significant benefit relative to placebo for the primary and secondary endpoints. However, MultiStem treatment was associated with lower rates of infections and pulmonary events, a reduction in hospitalization, and a reduction in life threatening adverse events and death. A higher proportion of patients receiving MultiStem treatment achieved an Excellent Outcome (p=0.10) compared to placebo. Post-hoc analyses indicate that, compared to placebo subjects (n=52), patients who received cell treatment earlier in the treatment window (≤36 hrs, n=27) had better Global Recovery (41.9% vs. 17.3%, p<0.01) and Excellent Outcome (18.5% v. 3.8%, p=0.03), had significantly better recovery by mRS shift analysis (p=0.03) and significantly reduced hospitalization (6.7d vs. 10.3 d, p<0.01).

Conclusions: Administration of MultiStem is safe and well tolerated in ischemic stroke patients within 48 hours of onset and reduces adverse events and death. Post-hoc analyses suggest that earlier administration of MultiStem may provide therapeutic benefit. Additional clinical studies exploring the optimal time frame for MultiStem administration are warranted.

Abstract TMP118: Increased Brain Derived Neurotrophic Factor (BDNF) and Vascular Endothelial Growth (VEGF) After Long Term Remote Ischemic Conditioning (RIC): Possible Role in Neurovascular Plasticity During Vascular Cognitive Impairment (VCI)

Background and Purpose: Vascular dysfunction and resultant chronic cerebral hypoperfusion leads to VCI, the second most common cause of dementia. We reported that RIC-therapy improves cerebral blood flow (CBF) in both murine stroke and VCI models. In the present work, we hypothesized that long-term RIC-therapy after VCI will promote neurovascular plasticity via up-regulation of growth factors.

Methods: Microcoil induced bilateral common carotid artery (BCAS) model was used to induce chronic hypoperfusion. Adult C57BL/6J male mice of (10-weeks) were assigned to 3-different groups (N=6), and subjected to Sham- (procedures of BCAS and RIC), BCAS- (induced VCI followed by RIC-Sham), and BCAS+RIC (induced VCI followed by RIC-therapy). RIC was started 7d post-surgery for 2-wks. At 4-wks post-surgery (1-wk after the cessation of RIC) CBF was determined using laser speckle contrast imager (LSCI). Functional outcomes were assessed using novel object recognition (NOR) test for non-spatial working memory, and hanging wire test for motor impairment. Histopathology as well as immunohistochemistry for BDNF and VGEF were also performed on the of the brain tissue collected after the neurobehavioral tests. Statistical significance was determined at p <0.05.

Results: RIC-therapy significantly improved CBF in BCAS+RIC group compared to the BCAS group. Mice from the BCAS group showed significant loss in the discrimination index as determined by the NOR test, and poor motor function strength in hanging wire test. RIC-therapy in BCAS+RIC group significantly improved functional outcomes as compared to the BCAS-group. Histopathological studies clearly showed prevention of neurovascular degeneration by RIC. Interestingly, immunohistochemical analysis revealed loss in BDNF and VEGF expressions in the BCAS-group as compared to Sham that was increased in the BCAS+RIC-group.

Conclusions: RIC-therapy attenuates neurovascular stress via improved CBF that attenuates neurovascular degeneration and prevents functional impairments. RIC increases BDNF and VEGF levels. Long term RIC-therapy could be a conventional therapy for aged individuals suffering from VCI and resultant motor impairment.

Humoral Mediators of Remote Ischemic Conditioning: Important Role of eNOS/NO/Nitrite

Remote ischemic conditioning (RIC) is a powerful cardioprotectant and neuroprotectant. The mechanism of protection likely involves circulating, blood-borne mediators that transmit the signal from the periphery to the brain. The neuroprotective effect of RIC may be partially related to improvements in cerebral blood flow (CBF). Nitrite is a key circulating mediator of RIC and may be a mediator of increased CBF and also mediate cytoprotection through its effects on nitrosylation of mitochondrial proteins such as complex I. Measuring plasma nitrite may serve as an important blood biomarker, and measuring CBF by techniques such as MRI arterial spin labeling (ASL) may be an ideal surrogate imaging biomarker in clinical trials of RIC.

Remote ischemic conditioning: a treatment for vascular cognitive impairment

There is a strong link between hypoperfusion and white matter (WM) damage in patients with leukoaraiosis and vascular cognitive impairment (VCI). Other than management of vascular risk factors, there is no treatment for WM damage and VCI that delays progression of the disease process to dementia. Observational studies suggest that exercise may prevent or slow down the progression of Alzheimer's disease (AD) and VCI. However, getting patients to exercise is challenging especially with advancing age and disability. Remote ischemic conditioning, an "exercise equivalent", allows exercise to be given with a "device" in the home for long periods of time. Since RIC increases CBF in pre-clinical studies and in humans, RIC may be an ideal therapy to treat VCI and WM disease and perhaps even sporadic AD. By using MRI imaging of WM progression, a sample size in the range of about 100 subjects per group could determine if RIC has activity in WM disease and VCI.

Addressing Disparities in Stroke Prevention for Atrial Fibrillation: Educational Opportunities

Disparities in atrial fibrillation (AF)-related stroke and mortality persist, especially racial disparities, within the US "Stroke Belt." This study identified barriers to optimal stroke prevention to develop a framework for clinician education. A comprehensive educational needs assessment was developed focusing on clinicians within the Stroke Belt. The mixed qualitative-quantitative approach included regional surveys and one-on-one clinician interviews. Identified contributors to disparities included implicit racial biases, lack of awareness of racial disparities in AF stroke risk, and lack of effective multicultural awareness and training. Additional barriers affecting disparities included patient medical mistrust and clinician-patient communication challenges. General barriers included lack of consistency in assessing stroke and anticoagulant-related bleeding risk, underuse of standardized risk assessment tools, discomfort with novel anticoagulants, and patient education deficiencies. Effective cultural competency training is one strategy to reduce disparities in AF-related stroke and mortality by improving implicit clinician bias, addressing medical mistrust, and improving clinician-patient communication.

Abstract T P417: Remote Ischemic Post Conditioning (RIPostC) Is Effective In A Mouse Model Of Vascular Cognitive Impairment

Background and Purpose: The mouse bilateral common carotid artery stenosis (BCAS) model is regarded as the best animal model for vascular cognitive impairment (VCI). RIPostC is a simple and safe therapy that others and we found protective in ischemic stroke. Other than risk factor control, there are no established treatments for VCI. However observational studies suggest exercise may be effective in patients with leukoaraiosis and cognitive impairment, the major form of VCI. Since RIPostC and exercise share some common mechanisms of action, we hypothesized that RIPostC would be effective in the mouse BCAS model and in VCI.

Methods: Adult C57BL/6J male mice of (10-weeks) were subjected to either Sham for BCAS or BCAS surgery using micro coils twined around common carotid arteries. We randomized BCAS mice to daily RIPostC or sham procedure for RIPostC beginning 7 days post-BCAS for 2 weeks until day 21. Cerebral blood flow (CBF) was measured by laser speckle contrast imager. All mice underwent blinded testing for cognitive functions using novel object recognition (NOR). Histopathological examination and beta amyloid contents were investigated in the brain at day 30 post-BCAS. Statistical significance was determined at p <0.05.

Results: At 1 hour, CBF was decreased significantly in all animals subjected to BCAS. RIPostC improved CBF in comparison to sham-operated group for RIPostC at day 14 and 28 post-VCI (p<0.05). BCAS impaired the discrimination index of mice in the NOR test but this was improved in the BCAS group treated with RIPostC (p<.05). Histopathological studies revealed that BCAS caused frequent vacuolization, cell death, microglial activation, loss in white matter (WM) and increased accumulation of beta amyloid. This was all attenuated significantly with RIPostC.

Conclusions: RIPostC improves CBF, cognition and reduces cell death, WM damage and beta amyloid accumulation in the mouse BCAS model. Chronic RIPostC-therapy might be an effective treatment for VCI and in patients with leukoaraiosis and cognitive impairment

Key words: RIPostC, VCI, white matter, beta-amyloid

Abstract W P253: Repeated Remote Ischemic Conditioning (RIC) after Intracerebral Hemorrhage Regulates Macrophage Polarization and CD36 Expression to Promote Hematoma Resolution

Background: RIC-therapy during sub-arachnoid hemorrhage in humans was found well tolerated. We tested the hypothesis that repeated daily RIC-therapy would improve post-ICH outcomes in mice.

Methods: ICH was induced by collagenase injection into the brain of CD1 male mice (4-mo old). Mice were randomized for either once daily RIC-therapy or related sham-procedure starting 2-hours post-ICH until sacrifice. RIC-therapy post-ICH was also tested in mice pre-treated with clodronate-liposome consequently deficient in macrophage population. Laser speckle imager (LSCI) was used to detect changes in peripheral ischemia resulting from space occupying hematoma. SWI/ FLASH (T2*W) MRI was used to estimate hematoma size. Behavioral outcomes were assessed by focal deficit score and beam walk challenge. Hemoglobin content in the brain tissue by spectrophotometry, macrophage polarization with CD36 expression in peripheral blood by flowcytometry, and histopathological analyses in the brain, were also performed. Statistical significance was determined at p<0.05.

Results: Even after 5-days post-ICH, peripheral cerebral ischemia was evident, which was significantly attenuated by RIC-therapy due to reduced hematoma size. Effect of RIC-therapy on hematoma resolution was abolished in the clodronate-liposome treated mice. Higher focal deficit score and impaired fine motor coordination were significantly evident in ICH mice, which was attenuated by RIC-therapy. Post-ICH increased hemoglobin content at day 5 was significantly reduced by RIC-therapy. Interestingly, repeated RIC-therapy promoted macrophage polarization towards M2 (anti-inflammatory) phenotype with increased CD36 expression. At 2-weeks post ICH, cresyl violet and Luxol-Fast blue staining showed significantly increased cell death and white matter degeneration (WMD), respectively, in the ICH mice. RIC-therapy after ICH significantly reduced the cell death and WMD in a 2-weeks follow up.

Conclusion: Human subjects deficient in CD36 have impaired capability of hematoma resolution. Long-term RIC-therapy might be helpful in spontaneous hematoma resolution via increased M2-type macrophage and CD36 expression.

Abstract 138: Perfusion Imaging of Intracranial Atherosclerotic Disease in SAMMPRIS

Background: Noninvasive perfusion imaging with CT (CTP) or MRI (PWI) provides key physiologic data regarding hemodynamics of intracranial atherosclerotic disease (ICAD). Parameters of delayed perfusion such as Tmax, time to peak (TTP), mean transit time (MTT) and cerebral blood volume (CBV) or flow (CBF) may disclose important mechanisms of stroke in ICAD. We analyzed CTP and PWI acquired in SAMMPRIS to identify the principal perfusion patterns, correlation with conventional angiography and potential links with clinical outcome.

Methods: CTP and PWI were identified in the SAMMPRIS imaging archive. Perfusion datasets were processed with Olea Sphere® to yield Tmax, TTP, MTT, CBV and CBF maps graded by 2 expert readers to identify markers of decreased, normal, or increased perfusion in the symptomatic territory. The resultant multiparametric perfusion patterns were correlated with clinical and angiographic variables, using Fisher’s exact test and Kaplan-Meier methods followed by log-rank tests.

Results: Perfusion imaging was available in 59 subjects at baseline and 42 at follow-up. Baseline perfusion included Tmax (decreased in 2, normal in 18, increased in 39); TTP (decreased in 2, normal in 18, increased in 39); MTT (decreased in 2, normal in 27, increased in 30); CBV (decreased in 5, normal in 42, increased in 12); CBF (decreased in 7, normal in 48, increased in 4). The baseline Tmax increases in 66% of subjects were associated with the combined (TICI and collaterals) diminished angiographic flow patterns (p=0.016) and with increased 30-day SIT (p=0.015). Baseline CBV changes were associated with stroke as a qualifying event (p=0.007), NIHSS (p=0.039), presenting symptoms of hypoperfusion (p=0.071), severity of stenosis (p=0.015), and angiographic flow patterns (p=0.009). Follow-up CTP or PWI revealed similar patterns to baseline, although delay maps normalized in patients after stenting.

Conclusions: Noninvasive perfusion imaging with CT or MRI discloses delayed flow caused by ICAD, often compensated by autoregulatory vasodilation (increased CBV) to maintain CBF in the downstream territory. Perfusion imaging parameters may reflect angiographic collateral flow patterns in ICAD, warranting further investigation as predictors of stroke risk.

Abstract T P79: Rapamycin Improves Outcome Post Stroke Injury by Enhancing Autophagy in Neuronal Cells

Background and Purpose: Previous literature and studies from our laboratory indicate that pharmacological inhibition and enhancement of autophagy are both effective in reducing infarct volume after stroke injury.

Methods: Mice were treated with rapamycin to enhance, and chloroquine to suppress autophagy in mice immediately after stroke injury and again 24 hours post stroke injury in a murine stroke model. Survival data and neurological score were taken before sacrifice at 48 hours and lesion size was determined by TTC. HT22 neuronal mouse hippocampal cells were treated for one hour with H2O2 to mimic an oxidative stress injury and treated concurrently with rapamycin to enhance autophagy, chloroquine to inhibit autophagy or ZVAD to inhibit apoptosis. The treatment with pharmacological agents continued for 24 hours. Cells were counted with trypan blue on a hemocytometer. Western blot analysis was used to monitor protein changes. shRNA to Atg5 was used to genetically inhibit autophagy.

Results: Both pharmacological agents showed decreased lesion size, though enhancement of autophagy with rapamycin exhibited a greater reduction in lesion size as well as increased survival and an improved neurological score. Rapamycin improved survival of neurons after oxidative injury and genetic inhibition of autophagy abrogated rapamycin's positive effect.

Conclusions: Rapamycin improves stroke outcome by enhancing autophagy in neuronal cells.

Abstract T P92: Remote Ischemic Conditioning (RIC) Attenuates Post-TBI Ischemic Injury and Improves Behavioral Outcomes

Background: Others and we reported that RIC-therapy is safe in humans, and protective in rodents that can be repeatedly used under both, hemorrhagic and ischemic stroke. Since TBI shares some common features of ischemic and hemorrhagic injury as in stroke, we hypothesized that RIC-therapy will remain protective in TBI, too.

Methods: We tested RIC-therapy in a closed-head injury model of pediatric TBI in male mice (28 days old). Mice were later randomized for either RIC-therapy or its sham-procedure once daily starting 1-hour post-TBI until sacrifice. Cerebral blood flow (CBF) was measured by laser speckle imager (LSCI), and MRI was used to estimate edema and cerebral perfusion. Mice were also tested for functional outcomes. Statistical significance was determined at p<0.05.

Results: Micro-CT showed a shallow dent along the median suture of skull. Closed-head TBI led to progressive acute ischemia, which was attenuated with time. However, reduced CBF and significant edema was observed at 48-hours post-TBI, which was attenuated by RIC-therapy. Open-field test showed no significant difference at 3 days post-TBI but in the narrow beam-walk challenge, TBI mice showed significantly impaired activity, which was improved by RIC-therapy. Flowcytometry in brain tissue confirmed significantly increased opening of mitochondrial permeability transition pore and necro-apoptotic cell death at 3 days post-TBI that was blocked by RIC-therapy. In a 3-weeks follow up, the mice with TBI were apparently normal but showed depressive phenotype in challenged environments, such as lesser mobility during forced swim test, and reduced cerebrovascular reserve capacity (CVRC). Flowcytometric analysis of the brain tissue at 3-weeks post-TBI showed reduced neuronal activity as detected by the poor population of cFOS positive neurons. RIC-therapy after TBI significantly attenuated the depressive phenotype, improved CVRC and cFOS positive neurons, collectively indicating improved neurovascular coupling and function.

Conclusion: Post-TBI RIC-therapy is safe and beneficial, and can be translated to prevent ischemic injury.

A 2 × 2 factorial design for the combination therapy of minocycline and remote ischemic perconditioning: efficacy in a preclinical trial in murine thromboembolic stroke model

Background

After the failure of so many drugs and therapies for acute ischemic stroke, innovative approaches are needed to develop new treatments. One promising strategy is to test combinations of agents in the pre-hospital setting prior to the administration of intravenous tissue plasminogen activator (IV-tPA) and/ or the use of mechanical reperfusion devices in the hospital.

Methods

We performed a 2 × 2 factorial design preclinical trial where we tested minocycline (MINO), remote ischemic perconditioning (RIPerC) and their combination treatment in a thromboembolic clot model of stroke in mice, without IV-tPA or later treated with IV-tPA at 4 hours post-stroke. Cerebral blood flow (CBF) was measured by laser speckle contrast imaging (LSCI), behavioral outcomes as neurological deficit score (NDS) and adhesive tape removal test, and infarct size measurement were performed at 48 hours post-stroke. Mice within the experimental sets were randomized for the different treatments, and all outcome measures were blinded.

Results

RIPerC significantly improved CBF as measured by LSCI in both with and without tPA treated mice (P < 0.001). MINO and RIPerC treatment were effective alone at reducing infarct size (p < 0.0001) and improving short-term functional outcomes (p < 0.001) in the tPA and non-tPA treated animals. The combination treatment of MINO and RIPerC significantly reduced the infarct size greater than either intervention alone (p < 0.05). There were trends in favor of improving functional outcomes after combination treatment of MINO and RIPerC; however combination treatment group was not significantly different than the individual treatments of MINO and RIPerC. There was no “statistical” interaction between minocycline and RIPerC treatments indicating that the effects of RIPerC and MINO were additive and not synergistic on the outcome measures.

Conclusion

In the future, combining these two safe and low cost interventions in the ambulance has the potential to “freeze” the penumbra and improve outcomes in stroke patients. This pre-clinical 2 × 2 design can be easily translated into a pre-hospital clinical trial.

Remote ischemic perconditioning is effective after embolic stroke in ovariectomized female mice

Remote ischemic conditioning is neuroprotective in young male rodents after experimental stroke. However, it has never been tested in females whom remain at higher risk of stroke injury after menopause. We tested remote ischemic perconditioning therapy (RIPerC) at 2 h after embolic stroke in ovariectomized (OVX) female mice with and without intravenous tissue plasminogen activator (IV-tPA) treatment. We assessed cerebral blood flow (CBF), neurobehavioral outcomes, infarction, hemorrhage, edema, and survival. RIPerC therapy with and without IV-tPA improved the CBF and neurobehavioral outcomes and reduced the infarction, hemorrhage, and edema significantly. Late IV-tPA alone at 4 h post-stroke neither improved the neurobehavior nor reduced the infarction but aggravated hemorrhage and mortality in OVX mice. RIPerC therapy prevented the increased mortality during late IV-tPA. Our study demonstrates for the first time that RIPerC therapy is effective in OVX females.

Minocycline repurposing in critical illness: focus on stroke

Stroke is a devastating disease associated with high morbidity and mortality. Despite the approved indication of systemic thrombolytic therapy in the United States for the acute management of ischemic stroke, its use is limited given a strict eligibility criteria and a risk for hemorrhagic transformation as a feared adverse effect. Many agents have been studied without success for neuroprotection in patients with stroke to reduce vascular injury and improve long-term functional outcomes. Minocycline is a tetracycline antibiotic that shows promise for its neuroprotective effects in multiple animal models and three human trials. It affects multiple pathways to reduce apoptosis, neuroinflammation, infarct size, and vascular injury. The aim of this review is to discuss current evidence for minocycline from pre-clinical and early clinical trials and its potential role in neuroprotection in patients with acute ischemic stroke.

Broad metabolic sensitivity profiling of a prototrophic yeast deletion collection

Background

Genome-wide sensitivity screens in yeast have been immensely popular following the construction of a collection of deletion mutants of non-essential genes. However, the auxotrophic markers in this collection preclude experiments on minimal growth medium, one of the most informative metabolic environments. Here we present quantitative growth analysis for mutants in all 4,772 non-essential genes from our prototrophic deletion collection across a large set of metabolic conditions.

Results

The complete collection was grown in environments consisting of one of four possible carbon sources paired with one of seven nitrogen sources, for a total of 28 different well-defined metabolic environments. The relative contributions to mutants' fitness of each carbon and nitrogen source were determined using multivariate statistical methods. The mutant profiling recovered known and novel genes specific to the processing of nutrients and accurately predicted functional relationships, especially for metabolic functions. A benchmark of genome-scale metabolic network modeling is also given to demonstrate the level of agreement between current in silico predictions and hitherto unavailable experimental data.

Conclusions

These data address a fundamental deficiency in our understanding of the model eukaryote Saccharomyces cerevisiae and its response to the most basic of environments. While choice of carbon source has the greatest impact on cell growth, specific effects due to nitrogen source and interactions between the nutrients are frequent. We demonstrate utility in characterizing genes of unknown function and illustrate how these data can be integrated with other whole-genome screens to interpret similarities between seemingly diverse perturbation types.

Development and characterization of a Yucatan miniature biomedical pig permanent middle cerebral artery occlusion stroke model

BACKGROUND

Efforts to develop stroke treatments have met with limited success despite an intense need to produce novel treatments. The failed translation of many of these therapies in clinical trials has lead to a close examination of the therapeutic development process. One of the major factors believed to be limiting effective screening of these treatments is the absence of an animal model more predictive of human responses to treatments. The pig may potentially fill this gap with a gyrencephalic brain that is larger in size with a more similar gray-white matter composition to humans than traditional stroke animal models. In this study we develop and characterize a novel pig middle cerebral artery occlusion (MCAO) ischemic stroke model.

METHODS

Eleven male pigs underwent MCAO surgery with the first 4 landrace pigs utilized to optimize stroke procedure and 7 additional Yucatan stroked pigs studied over a 90 day period. MRI analysis was done at 24 hrs and 90 days and included T2w, T2w FLAIR, T1w FLAIR and DWI sequences and associated ADC maps. Pigs were sacrificed at 90 days and underwent gross and microscopic histological evaluation. Significance in quantitative changes was determined by two-way analysis of variance and post-hoc Tukey's Pair-Wise comparisons.

RESULTS

MRI analysis of animals that underwent MCAO surgery at 24 hrs had hyperintense regions in T2w and DWI images with corresponding ADC maps having hypointense regions indicating cytotoxic edema consistent with an ischemic stroke. At 90 days, region of interest analysis of T1 FLAIR and ADC maps had an average lesion size of 59.17 cc, a loss of 8% brain matter. Histological examination of pig brains showed atrophy and loss of tissue, consistent with MRI, as well as glial scar formation and macrophage infiltration.

CONCLUSIONS

The MCAO procedure led to significant and consistent strokes with high survivability. These results suggest that the pig model is potentially a robust system for the study of stroke pathophysiology and potential diagnostics and therapeutics.

Abstract 200: Team of Neurohospitalists, Telestroke, and Nurse Stroke Coordinator Increases the Use of Intravenous Alteplase in a Community Hospital

Background and Purpose: The FDA approved IV tPA in 1996 for the treatment of AIS. Its safety and efficacy have been demonstrated in community hospitals (CH) and it is now the standard of care; but intravenous Alteplase (IV tPA) remains underemployed. It is used in fewer than 5% of AIS patients. Short supply of neurologic manpower and concern over adverse effect contribute to this underutilization. Our hypothesis was that a combination of onsite neurohospitalists (NH), telestroke (TS), nurse stroke coordinator (NC), and education of staff and community would increase IV tPA use in a mid-sized CH PSC without compromise of safety or outcome.

Methods: The hospital is a 197 bed nonprofit hospital located 60 miles from Atlanta serving a population of 350,000 in 10 counties. The hospital has been certified as a PSC since August 2004; however, the volume of AIS admissions and use of IV tPA remained low through 2008. The stroke program thus was reorganized in 2009: two full-time NH were hired to provide onsite coverage daily from 8am to 6pm, the REACH™ TS System was installed to provide the remainder of coverage, a NC was hired, and an education plan for staff and community was implemented. Patients treated with IV tPA via TS were admitted to the neuro-ICU by medical hospitalists initially with NH assuming primary care of these patients within hours. AIS admission and IV tPA use data for 2002- 2008 were compared with those for 2009 - 2012. Outcomes, assessed at discharge, 2009 - 2012 were also examined. Favorable outcome was defined as a mRS of 0 or 1.

Results: From 2002-2008, 25 of 933 AIS were treated with IV tPA: 3.6 per year (2.7%). In contrast, from 2009-2012, 105 of 802 AIS received IV tPA: 26.25 per year (13%) with favorable outcome in 47 (45%). Of 64 patients treated by NH, 28 (44%) achieved favorable outcome as did 19 of 41 (46%) TS patients. These outcomes were not statistically different (p=0.92). There were 5 deaths (3 NH, 2 TS), none attributable to tPA. There were no sICH.

Conclusions: A model combining NH, TS, NC, and education in a CH PSC significantly increased the use of IV tPA without compromising safety or effectiveness. Such a model may be an option where resources are limited.

Abstract T MP20: A Rapid Clot Lysis Assay to Predict Response to IV rt-PA in Stroke

Background: The cornerstone of acute stroke therapy is intravenous rt-PA, with the goal of rapid thrombolysis and restoration of blood flow. Unfortunately, less than half of patients treated have a favorable outcome. Since recanalization is closely correlated with the clinical response, endogenous resistance to rt-PA may inhibit thrombolysis and neurologic improvement. The primary objective of this research study was to evaluate whether an in vitro clot lysis assay and thrombolytic biomarkers could predict response to IV rt-PA in acute ischemic stroke patients

Methods: Ischemic stroke patients who received IV rt-PA were recruited from two sites (Augusta, GA and Udine, Italy). Blood samples were collected prior to rt-PA administration and a favorable clinical response to rt-PA was specified as an NIHSS score of two or less at 24 hours. The time required for 50% platelet-poor clot lysis (C50%) was measured by an in vitro turbidimetric assay. The endogenous major fibrinolytic inhibitors (tissue plasminogen inhibitor, PAI-1; and α2-antiplasmin, α2-AP), D-dimer, fibrinogen and pro-thrombin time (PT), were assessed and correlated with clinical outcome.

Results: We enrolled 54 rt-PA recipients (63±15 years; 72% male, and 85% white). The mean NIHSS was 11.2±5.1 at admission and 8.2±8.1 at 24 hours; 36% of patients had a favorable clinical response. There was a moderate reduction in C50% among patients with a favorable clinical outcome compared to those with an unfavorable outcome (669.5±46.3 vs. 704.7±91.6; p=0.075). There was no significant difference in PT (13.6±0.8 sec vs. 13.8±1.2 sec; p=0.444), PAI-1(28.2±34.1 pg/mL vs. 19.8±25.9 pg/mL; p=0.321), α2-AP (85.1±7.2 % vs. 88.8±10.1 %; p=0.153), D-dimer (269.5±232.2 ng/mL vs. 368.2±444.6 ng/mL; p=0.303) or fibrinogen (318.1±71.4 mg/dL vs. 343.0±173.1 mg/dL; p=0.465) levels between subjects with favorable and unfavorable response to rt-PA. Summary: Lack of response to IV rt-PA in stroke patients may reflect endogenous resistance to fibrinolysis reflected by prolonged clot lysis in vitro. The utility of clot lysis to predict rt-PA unresponsiveness should be tested in a larger clinical study.