1
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Zhou Z, Xu K, Yu J. Endovascular treatment of main trunk aneurysms in the residual anterior circulation in moyamoya disease. Neuroradiol J 2022; 35:580-591. [PMID: 35050820 PMCID: PMC9513918 DOI: 10.1177/19714009211067413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Main trunk aneurysms in the residual anterior circulation in moyamoya disease (MMD) are uncommon, and in such cases, endovascular treatment (EVT) is a good choice. MATERIALS AND METHODS A retrospective study was performed on 35 consecutive patients admitted to our hospital who were diagnosed with MMD and main trunk aneurysms in the residual anterior circulation and were treated with EVT. RESULT The 35 patients were aged 38-77 years (mean, 56.1 ± 8.8 years) and included 17 females (48.6%, 17/35). There were 29 cases (82.9%, 29/35) of hemorrhagic onset. In 35 patients, there were 38 main trunk aneurysms in the residual anterior circulation. Thirty-eight aneurysms underwent coiling; among them, coiling with stent assistance was used in the treatment of 6 (15.8%, 6/38) aneurysms. The immediate modified Raymond-Roy classification (MRRC) was grade I for all aneurysms. Among 35 patients, intraoperative bleeding occurred in 2 (5.7%, 2/35) patients. After EVT, immediate hemiplegia occurred in 4 (11.4%, 4/35) patients, and immediate coma occurred in 1 (2.9%, 1/35) patient. At discharge, in 35 patients, the Glasgow Outcome Scale (GOS) was five in 88.6% of them. Of 35 patients, 68.6% had follow-up data, GOS was five in 87.5% patients, and the MRRC was grade I for all aneurysms in the follow-up angiography. CONCLUSION For main trunk aneurysms in the residual anterior circulation in MMD, although EVT was accompanied by potential ischemic and hemorrhagic complications, which should be considered, EVT can still offer an acceptable prognosis in more than 85% of patients.
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Affiliation(s)
- Zibo Zhou
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Kan Xu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
| | - Jinlu Yu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun, China
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2
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Ghozy S, Reda A, Varney J, Elhawary AS, Shah J, Murry K, Sobeeh MG, Nayak SS, Azzam AY, Brinjikji W, Kadirvel R, Kallmes DF. Neuroprotection in Acute Ischemic Stroke: A Battle Against the Biology of Nature. Front Neurol 2022; 13:870141. [PMID: 35711268 PMCID: PMC9195142 DOI: 10.3389/fneur.2022.870141] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 04/21/2022] [Indexed: 12/22/2022] Open
Abstract
Stroke is the second most common cause of global death following coronary artery disease. Time is crucial in managing stroke to reduce the rapidly progressing insult of the ischemic penumbra and the serious neurologic deficits that might follow it. Strokes are mainly either hemorrhagic or ischemic, with ischemic being the most common of all types of strokes. Thrombolytic therapy with recombinant tissue plasminogen activator and endovascular thrombectomy are the main types of management of acute ischemic stroke (AIS). In addition, there is a vital need for neuroprotection in the setting of AIS. Neuroprotective agents are important to investigate as they may reduce mortality, lessen disability, and improve quality of life after AIS. In our review, we will discuss the main types of management and the different modalities of neuroprotection, their mechanisms of action, and evidence of their effectiveness after ischemic stroke.
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Affiliation(s)
- Sherief Ghozy
- Department of Neuroradiology, Mayo Clinic, Rochester, MN, United States.,Nuffield Department of Primary Care Health Sciences and Department for Continuing Education (EBHC Program), Oxford University, Oxford, United Kingdom
| | - Abdullah Reda
- Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Joseph Varney
- School of Medicine, American University of the Caribbean, Philipsburg, Sint Maarten
| | | | - Jaffer Shah
- Medical Research Center, Kateb University, Kabul, Afghanistan
| | | | - Mohamed Gomaa Sobeeh
- Faculty of Physical Therapy, Sinai University, Cairo, Egypt.,Faculty of Physical Therapy, Cairo University, Giza, Egypt
| | - Sandeep S Nayak
- Department of Internal Medicine, NYC Health + Hospitals/Metropolitan, New York, NY, United States
| | - Ahmed Y Azzam
- Faculty of Medicine, October 6 University, Giza, Egypt
| | - Waleed Brinjikji
- Department of Neurosurgery, Mayo Clinic Rochester, Rochester, MN, United States
| | | | - David F Kallmes
- Department of Neuroradiology, Mayo Clinic, Rochester, MN, United States
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3
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Vos EM, Geraedts VJ, van der Lugt A, Dippel DWJ, Wermer MJH, Hofmeijer J, van Es ACGM, Roos YBWEM, Peeters-Scholte CMPCD, van den Wijngaard IR. Systematic Review - Combining Neuroprotection With Reperfusion in Acute Ischemic Stroke. Front Neurol 2022; 13:840892. [PMID: 35370911 PMCID: PMC8969766 DOI: 10.3389/fneur.2022.840892] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/17/2022] [Indexed: 12/22/2022] Open
Abstract
Background Clinical trials of neuroprotection in acute ischemic stroke (AIS) have provided disappointing results. Reperfusion may be a necessary condition for positive effects of neuroprotective treatments. This systematic review provides an overview of efficacy of neuroprotective agents in combination with reperfusion therapy in AIS. Methods A literature search was performed on the following databases, namely PubMed, Embase, Web of Science, Cochrane Library, Emcare. All databases were searched up to September 23rd 2021. All randomized controlled trials in which patients were treated with neuroprotective strategies within 12 h of stroke onset in combination with intravenous thrombolysis (IVT), endovascular therapy (EVT), or both were included. Results We screened 1,764 titles/abstracts and included 30 full reports of unique studies with a total of 16,160 patients. In 15 studies neuroprotectants were tested for clinical efficacy, where all patients had to receive reperfusion therapies, either IVT and/or EVT. Heterogeneity in reported outcome measures was observed. Treatment was associated with improved clinical outcome for: 1) uric acid in patients treated with EVT and IVT, 2) nerinetide in patients who underwent EVT without IVT, 3) imatinib in stroke patients treated with IVT with or without EVT, 4) remote ischemic perconditioning and IVT, and 5) high-flow normobaric oxygen treatment after EVT, with or without IVT. Conclusion Studies specifically testing effects of neuroprotective agents in addition to IVT and/or EVT are scarce. Future neuroprotection studies should report standardized functional outcome measures and combine neuroprotective agents with reperfusion therapies in AIS or aim to include prespecified subgroup analyses for treatment with IVT and/or EVT.
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Affiliation(s)
- E. M. Vos
- Department of Neurology, The Hague Medical Center, The Hague, Netherlands
- *Correspondence: E. M. Vos
| | - V. J. Geraedts
- Department of Neurology, The Hague Medical Center, The Hague, Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
| | - A. van der Lugt
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, Netherlands
| | - D. W. J. Dippel
- Department of Neurology, Erasmus University Medical Center, Rotterdam, Netherlands
| | - M. J. H. Wermer
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
| | - J. Hofmeijer
- Department of Neurology, Rijnstate Hospital, Arnhem, Netherlands
- Department of Clinical Neurophysiology, Technical Medical Centre, University of Twente, Enschede, Netherlands
| | - A. C. G. M. van Es
- Department of Radiology, Leiden University Medical Center, Leiden, Netherlands
- Department of Radiology, The Hague Medical Center, The Hague, Netherlands
| | - Y. B. W. E. M. Roos
- Department of Neurology, Amsterdam University Medical Center, Amsterdam, Netherlands
| | | | - I. R. van den Wijngaard
- Department of Neurology, The Hague Medical Center, The Hague, Netherlands
- Department of Neurology, Leiden University Medical Center, Leiden, Netherlands
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4
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Gonzales NR, Grotta JC. Pharmacologic Modification of Acute Cerebral Ischemia. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00057-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Mulder IA, van Bavel ET, de Vries HE, Coutinho JM. Adjunctive cytoprotective therapies in acute ischemic stroke: a systematic review. Fluids Barriers CNS 2021; 18:46. [PMID: 34666786 PMCID: PMC8524879 DOI: 10.1186/s12987-021-00280-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 09/29/2021] [Indexed: 01/08/2023] Open
Abstract
With the introduction of endovascular thrombectomy (EVT), a new era for treatment of acute ischemic stroke (AIS) has arrived. However, despite the much larger recanalization rate as compared to thrombolysis alone, final outcome remains far from ideal. This raises the question if some of the previously tested neuroprotective drugs warrant re-evaluation, since these compounds were all tested in studies where large-vessel recanalization was rarely achieved in the acute phase. This review provides an overview of compounds tested in clinical AIS trials and gives insight into which of these drugs warrant a re-evaluation as an add-on therapy for AIS in the era of EVT. A literature search was performed using the search terms "ischemic stroke brain" in title/abstract, and additional filters. After exclusion of papers using pre-defined selection criteria, a total of 89 trials were eligible for review which reported on 56 unique compounds. Trial compounds were divided into 6 categories based on their perceived mode of action: systemic haemodynamics, excitotoxicity, neuro-inflammation, blood-brain barrier and vasogenic edema, oxidative and nitrosative stress, neurogenesis/-regeneration and -recovery. Main trial outcomes and safety issues are summarized and promising compounds for re-evaluation are highlighted. Looking at group effect, drugs intervening with oxidative and nitrosative stress and neurogenesis/-regeneration and -recovery appear to have a favourable safety profile and show the most promising results regarding efficacy. Finally, possible theories behind individual and group effects are discussed and recommendation for promising treatment strategies are described.
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Affiliation(s)
- I A Mulder
- Department of Biomedical Engineering and Physics, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
| | - E T van Bavel
- Department of Biomedical Engineering and Physics, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H E de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam Neuroscience, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - J M Coutinho
- Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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6
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Ortiz JF, Cruz C, Patel A, Khurana M, Eissa-Garcés A, Alzamora IM, Halan T, Altamimi A, Ruxmohan S, Patel UK. Opioid Antagonist in the Treatment of Ischemic Stroke. Brain Sci 2021; 11:brainsci11060805. [PMID: 34206997 PMCID: PMC8233760 DOI: 10.3390/brainsci11060805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/01/2021] [Accepted: 06/08/2021] [Indexed: 11/23/2022] Open
Abstract
Stroke is a leading cause of death and disability, and novel treatments need to be found, particularly drugs with neuroprotective and restorative effects. Lately, there has been an increased interest in the relationship between opioids and ischemic stroke. To further appreciate this association between opioids and stroke, we conducted a systematic review to investigate anti-opioid medication’s effectiveness in treating ischemic stroke. We used PubMed advanced-strategy and Google Scholar searches and only included full-text clinical trials on humans and written in the English language. After applying the inclusion/exclusion criteria, seven clinical trials were reviewed. Only one of the naloxone and nalmefene clinical trials showed statistically favorable results. Overall, the nalmefene clinical trials used more updated measures (NIHSS, GOS) to evaluate recovery and functional status in ischemic stroke patients than the naloxone clinical trials. There was less bias in the nalmefene clinical trials. Animal and in vitro studies have showed promising results. Additional research should be conducted with new clinical trials of both drugs with larger samples in patients less than 70 years old and moderate to severe infarcts.
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Affiliation(s)
- Juan Fernando Ortiz
- School of Medicine, Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito 170901, Ecuador; (C.C.); (A.E.-G.); (I.M.A.)
- Correspondence: (J.F.O.); (A.P.)
| | - Claudio Cruz
- School of Medicine, Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito 170901, Ecuador; (C.C.); (A.E.-G.); (I.M.A.)
| | - Amrapali Patel
- Neurology Department, School of Medicine, AMC MET Medical College, Ahmedabad 380008, India
- Correspondence: (J.F.O.); (A.P.)
| | - Mahika Khurana
- Public Health Department, University of California Berkeley, Berkeley, CA 94720, USA;
| | - Ahmed Eissa-Garcés
- School of Medicine, Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito 170901, Ecuador; (C.C.); (A.E.-G.); (I.M.A.)
| | - Ivan Mateo Alzamora
- School of Medicine, Colegio de Ciencias de la Salud, Universidad San Francisco de Quito, Quito 170901, Ecuador; (C.C.); (A.E.-G.); (I.M.A.)
| | - Taras Halan
- School of Medicine, Ternopil National Medical University, 46002 Ternopil, Ukraine;
| | - Abbas Altamimi
- Emergency Department, Amiri Hospital, Sharq 15300, Kuwait;
| | - Samir Ruxmohan
- Department of Neurology, Larkin Community Hospital, Miami, FL 10029, USA;
| | - Urvish K. Patel
- Public Health Department, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
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7
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Scuteri D, Mantovani E, Tamburin S, Sandrini G, Corasaniti MT, Bagetta G, Tonin P. Opioids in Post-stroke Pain: A Systematic Review and Meta-Analysis. Front Pharmacol 2020; 11:587050. [PMID: 33424596 PMCID: PMC7793939 DOI: 10.3389/fphar.2020.587050] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/22/2020] [Indexed: 01/19/2023] Open
Abstract
Background: Post-stroke pain is one of the most common sequelae of stroke, which stands among the leading causes of death and adult-acquired disability worldwide. The role and clinical efficacy of opioids in post-stroke pain syndromes is still debated. Objectives: Due to the important gap in knowledge on the management of post-stroke pain, this systematic review aimed at assessing the efficacy of opioids in post-stroke pain syndromes. Methods: A literature search was conducted on databases relevant for medical scientific literature, i.e. PubMed/MEDLINE, Scopus, Web of Science and Cochrane Library databases from databases inception until August 31st, 2020 for clinical trials assessing the effects of opioids and opioid antagonists on pain reduction and pain related symptoms in patients with post-stroke pain syndromes. Studies assessing the effects of other medications (e.g., tricyclic antidepressant, pregabalin) or non - pharmacological management strategies (e.g., neurostimulation techniques) were excluded. The selected studies have been subjected to examination of the risk of bias. Results: The literature search retrieved 83,435 results. After duplicates removal, 34,285 articles were title and abstract screened. 25 full texts were assessed and 8 articles were identified to be eligible for inclusion in the qualitative summary and narrative analysis, of which three were placebo-controlled and two were dose-response. Among placebo-controlled studies, two evaluated the analgesic effect of morphine and one assessed the effects of the opioid antagonist naloxone on patients with central post-stroke pain. With regard to dose-response studies, both were on patients with central post-stroke pain, one assessing the efficacy of levorphanol, and the other on naloxone. Seven out of eight included studies showed an overall slight analgesic effect of opioids, with less consistent effects on other pain-related symptoms (e.g., mood, quality of life). The randomized controlled trials were subjected to meta-analysis and rating of the quality of evidence for the two outcomes considered according to GRADE (Grading of Recommendations, Assessment, Development and Evaluations) system. The overall results are inconclusive because of the small number of studies and of patients. Conclusions: The limited number of the included studies and their heterogeneity in terms of study design do not support the efficacy of opioids in post-stroke pain and in pain-related outcomes. Large double-blind randomized clinical trials with objective assessment of pain and related symptoms are needed to further investigate this topic.
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Affiliation(s)
- Damiana Scuteri
- Pharmacotechnology Documentation and Transfer Unit, Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Elisa Mantovani
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Stefano Tamburin
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Giorgio Sandrini
- Department of Brain and Behavioral Sciences, University of Pavia, IRCCS C. Mondino Foundation Neurologic Institute, Pavia, Italy
| | - Maria Tiziana Corasaniti
- Department of Health Sciences, University "Magna Graecia" of Catanzaro, Catanzaro, Italy.,School of Hospital Pharmacy, University "Magna Graecia" of Catanzaro, Catanzaro, Italy
| | - Giacinto Bagetta
- Pharmacotechnology Documentation and Transfer Unit, Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Paolo Tonin
- Regional Center for Serious Brain Injuries, S. Anna Institute, Crotone, Italy
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8
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Li MY, Chen C, Wang ZG, Ke JJ, Feng XB. Effect of Nalmefene on Delayed Neurocognitive Recovery in Elderly Patients Undergoing Video-assisted Thoracic Surgery with One Lung Ventilation. Curr Med Sci 2020; 40:380-388. [DOI: 10.1007/s11596-020-2170-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 01/15/2020] [Indexed: 11/24/2022]
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9
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Dhir N, Medhi B, Prakash A, Goyal MK, Modi M, Mohindra S. Pre-clinical to Clinical Translational Failures and Current Status of Clinical Trials in Stroke Therapy: A Brief Review. Curr Neuropharmacol 2020; 18:596-612. [PMID: 31934841 PMCID: PMC7457423 DOI: 10.2174/1570159x18666200114160844] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/31/2019] [Accepted: 12/28/2019] [Indexed: 12/16/2022] Open
Abstract
In stroke (cerebral ischemia), despite continuous efforts both at the experimental and clinical level, the only approved pharmacological treatment has been restricted to tissue plasminogen activator (tPA). Stroke is the leading cause of functional disability and mortality throughout worldwide. Its pathophysiology starts with energy pump failure, followed by complex signaling cascade that ultimately ends in neuronal cell death. Ischemic cascade involves excessive glutamate release followed by raised intracellular sodium and calcium influx along with free radicals' generation, activation of inflammatory cytokines, NO synthases, lipases, endonucleases and other apoptotic pathways leading to cell edema and death. At the pre-clinical stage, several agents have been tried and proven as an effective neuroprotectant in animal models of ischemia. However, these agents failed to show convincing results in terms of efficacy and safety when the trials were conducted in humans following stroke. This article highlights the various agents which have been tried in the past but failed to translate into stroke therapy along with key points that are responsible for the lagging of experimental success to translational failure in stroke treatment.
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Affiliation(s)
| | - Bikash Medhi
- Address correspondence to this author at the Department of Pharmacology, Research Block B, 4th Floor, Room no 4043, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, 160012, India; E-mail:
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10
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Slupe AM, Kirsch JR. Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection. J Cereb Blood Flow Metab 2018; 38:2192-2208. [PMID: 30009645 PMCID: PMC6282215 DOI: 10.1177/0271678x18789273] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/11/2018] [Accepted: 06/25/2018] [Indexed: 12/12/2022]
Abstract
Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.
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Affiliation(s)
- Andrew M Slupe
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Jeffrey R Kirsch
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
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11
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Gaidhani N, Uteshev VV. Treatment duration affects cytoprotective efficacy of positive allosteric modulation of α7 nAChRs after focal ischemia in rats. Pharmacol Res 2018; 136:121-132. [PMID: 30205140 PMCID: PMC6218269 DOI: 10.1016/j.phrs.2018.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/22/2018] [Accepted: 09/02/2018] [Indexed: 12/30/2022]
Abstract
To minimize irreversible brain injury after acute ischemic stroke (AIS), the time to treatment (i.e., treatment delay) should be minimized. However, thus far, all cytoprotective clinical trials have failed. Analysis of literature identified short treatment durations (≤72 h) as a common motif among completed cytoprotective clinical trials. Here, we argue that short cytoprotective regimens even if given early after AIS may only slow down the evolution of ischemic brain injury and fail to deliver sustained long-term solutions leading to relapses that may be misinterpreted for conceptual failure of cytoprotection. In this randomized blinded study, we used young adult male rats subjected to transient 90 min suture middle cerebral artery occlusion (MCAO) and treated with acute vs. sub-chronic regimens of PNU120596, a prototypical positive allosteric modulator of α7 nicotinic acetylcholine receptors with anti-inflammatory cytoprotective properties to test the hypothesis that insufficient treatment durations may reduce therapeutic benefits of otherwise efficacious cytoprotectants after AIS. A single acute treatment 90 min after MCAO significantly reduced brain injury and neurological deficits 24 h later, but these effects vanished 72 h after MCAO. These relapses were avoided by utilizing sub-chronic treatments. Thus, extending treatment duration augments therapeutic efficacy of PNU120596 after MCAO. Furthermore, sub-chronic treatments could offset the negative effects of prolonged treatment delays in cases where the acute treatment window after MCAO was left unexploited. We conclude that a combination of short treatment delays and prolonged treatment durations may be required to maximize therapeutic effects of PNU120596, reduce relapses and ensure sustained therapeutic efficacy after AIS. Similar concepts may hold for other cytoprotectants including those that failed in clinical trials.
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Affiliation(s)
- Nikhil Gaidhani
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States
| | - Victor V Uteshev
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, United States.
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12
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The neuroprotective role of the brain opioid system in stroke injury. Drug Discov Today 2018; 23:1385-1395. [DOI: 10.1016/j.drudis.2018.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/30/2018] [Accepted: 02/26/2018] [Indexed: 11/18/2022]
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13
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Gonzales NR, Grotta JC. Pharmacologic Modification of Acute Cerebral Ischemia. Stroke 2016. [DOI: 10.1016/b978-0-323-29544-4.00055-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Mandava P, Shah SD, Sarma AK, Kent TA. An Outcome Model for Intravenous rt-PA in Acute Ischemic Stroke. Transl Stroke Res 2015; 6:451-7. [PMID: 26385545 DOI: 10.1007/s12975-015-0427-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 09/04/2015] [Indexed: 01/19/2023]
Abstract
Most early phase trials in stroke and brain trauma have failed in phase 3, including efforts to improve acute ischemic stroke outcomes beyond that achieved by intravenous recombinant tissue plasminogen activator (t-PA) (IVT). With the exception of more recent stent retriever trials, most subsequent phase 3 trials failed. We previously showed that baseline imbalances, non-linear relationships of these factors to outcome, and unrepresentative control populations invalidate traditional statistical analysis in early trials of heterogeneous diseases such as stroke. We developed an alternative approach using a pooled outcome model derived from control arms of randomized clinical trial (RCTs). This model then permits comparing treatment trials to an expected outcome of a pooled population. Here, we hypothesized we could develop such a model for IVT and tested it against outcomes without IVT. We surveyed literature for all trials involving one arm with IVT reporting baseline National Institute Stroke Scale (NIHSS), age, and outcome. A non-linear fit was performed including multi-dimensional statistical intervals (±95 %) permitting visual comparison of outcomes at their own baselines. We compared models derived from non-IVT control arms. Models from 24 IVT RCTs representing 3195 subjects were successfully generated for functional outcome, modified Rankin Scale (mRS) 0-2 (r(2) = 0. 83, p < 0.001), and mortality (r(2) = 0.54; p = 0.001). We confirmed better outcomes compared to no IVT and mixed use IVT models across the range of baseline factors. It was possible to generate an expected outcome model for IVT from existing literature. We confirmed benefit compared to placebo. This model should be useful to compare to new agents without the need for statistical manipulation.
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Affiliation(s)
- Pitchaiah Mandava
- Michael E. DeBakey VA Medical Center, 2002 Holcombe Blvd (127), Houston, TX, 77030, USA.
- Stroke Outcomes Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
| | - Shreyansh D Shah
- Stroke Outcomes Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Anand K Sarma
- Stroke Outcomes Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
| | - Thomas A Kent
- Michael E. DeBakey VA Medical Center, 2002 Holcombe Blvd (127), Houston, TX, 77030, USA
- Center for Translational Research in Inflammatory Diseases, Michael E. DeBakey VA Medical Center, Houston, TX, USA
- Stroke Outcomes Laboratory, Department of Neurology, Baylor College of Medicine, Houston, TX, USA
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15
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Yang L, Islam MR, Karamyan VT, Abbruscato TJ. In vitro and in vivo efficacy of a potent opioid receptor agonist, biphalin, compared to subtype-selective opioid receptor agonists for stroke treatment. Brain Res 2015; 1609:1-11. [PMID: 25801116 DOI: 10.1016/j.brainres.2015.03.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/03/2015] [Accepted: 03/12/2015] [Indexed: 12/31/2022]
Abstract
To meet the challenge of identification of new treatments for stroke, this study was designed to evaluate a potent, nonselective opioid receptor (OR) agonist, biphalin, in comparison to subtype selective OR agonists, as a potential neuroprotective drug candidate using in vitro and in vivo models of ischemic stroke. Our in vitro approach included mouse primary neuronal cells that were challenged with glutamate and hypoxic/aglycemic (H/A) conditions. We observed that 10nM biphalin, exerted a statistically significant neuroprotective effect after glutamate challenge, compared to all selective opioid agonists, according to lactate dehydrogenase (LDH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Moreover, 10nM biphalin provided superior neuroprotection after H/A-reoxygenation compared to selective opioid agonists in all cases. Our in vitro investigations were supported by in vivo studies which indicate that the nonselective opioid agonist, biphalin, achieves enhanced neuroprotective potency compared to any of the selective opioid agonists, evidenced by reduced edema and infarct ratios. Reduction of edema and infarction was accompanied by neurological improvement of the animals in two independent behavioral tests. Collectively these data strongly suggest that concurrent agonist stimulation of mu, kappa and delta ORs with biphalin is neuroprotective and superior to neuroprotection by activation of any single OR subtype.
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Affiliation(s)
- Li Yang
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S Coulter Drive, Amarillo, TX 79106, USA; Center for Blood-Brain Barrier Research, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, USA
| | - Mohammad R Islam
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S Coulter Drive, Amarillo, TX 79106, USA; Center for Blood-Brain Barrier Research, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, USA
| | - Vardan T Karamyan
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S Coulter Drive, Amarillo, TX 79106, USA; Center for Blood-Brain Barrier Research, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, USA
| | - Thomas J Abbruscato
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S Coulter Drive, Amarillo, TX 79106, USA; Center for Blood-Brain Barrier Research, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, USA.
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Zheng J, Li H, Guo R, Chen R, Lin S, Liu M, You C. Neuroprotection of nalmefene for postoperative patients with spontaneous intracerebral hemorrhage. Int J Neurosci 2014; 125:918-23. [DOI: 10.3109/00207454.2014.985294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Grupke S, Hall J, Dobbs M, Bix GJ, Fraser JF. Understanding history, and not repeating it. Neuroprotection for acute ischemic stroke: from review to preview. Clin Neurol Neurosurg 2014; 129:1-9. [PMID: 25497127 DOI: 10.1016/j.clineuro.2014.11.013] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 11/07/2014] [Accepted: 11/13/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Neuroprotection for ischemic stroke is a growing field, built upon the elucidation of the biochemical pathways of ischemia first studied in the 1970s. Beginning in the early 1990s, means by which to pharmacologically intervene and counteract these pathways have been sought, though with little clinical success. Through a comprehensive review of translations from laboratory to clinic, we aim to evaluate individual mechanisms of action, while highlighting potential barriers to success that will guide future research. METHODS The MEDLINE database and The Internet Stroke Center clinical trials registry were queried for trials involving the use of neuroprotective agents in acute ischemic stroke in human subjects. For the purpose of the review, neuroprotective agents refer to medications used to preserve or protect the potentially ischemic tissue after an acute stroke, excluding treatments designed to re-establish perfusion. This excludes mechanical or pharmacological thrombolytics, anti-thrombic medications, or anti-platelet therapies. RESULTS This review summarizes previously trialed neuroprotective agents, including but not limited to glutamate neurotransmission blockers, anti-oxidants, GABA agonists, leukocyte migration blockers, various small cation channel modulators, narcotic antagonists, and phospholipid membrane stabilizers. We outline key biochemical steps in ischemic injury that are the proposed areas of intervention. The agents, time to administration of therapeutic agent, follow-up, and trial results are reported. DISCUSSION Stroke trials in humans are burdened with a marked heterogeneity of the patient population that is not seen in animal studies. Also, trials to date have included patients that are likely treated at a time outside of the window of efficacy for neuroprotective drugs, and have not effectively combined thrombolysis with neuroprotection. Through an evaluation of the accomplishments and failures in neuroprotection research, we propose new methodologies, agents, and techniques that may provide new routes for success.
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Affiliation(s)
- Stephen Grupke
- Department of Neurosurgery, University of Kentucky, Lexington, USA
| | - Jason Hall
- Department of Neurosurgery, University of Kentucky, Lexington, USA
| | - Michael Dobbs
- Department of Neurology, University of Kentucky, Lexington, USA
| | - Gregory J Bix
- Department of Neurology, University of Kentucky, Lexington, USA; Department of Anatomy and Neurobiology, University of Kentucky, Lexington, USA
| | - Justin F Fraser
- Department of Neurosurgery, University of Kentucky, Lexington, USA; Department of Neurology, University of Kentucky, Lexington, USA; Department of Anatomy and Neurobiology, University of Kentucky, Lexington, USA; Department of Radiology, University of Kentucky, Lexington, USA.
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Alonso de Leciñana M, Egido J, Casado I, Ribó M, Dávalos A, Masjuan J, Caniego J, Martínez Vila E, Díez Tejedor E, Fuentes (Secretaría) B, Álvarez-Sabin J, Arenillas J, Calleja S, Castellanos M, Castillo J, Díaz-Otero F, López-Fernández J, Freijo M, Gállego J, García-Pastor A, Gil-Núñez A, Gilo F, Irimia P, Lago A, Maestre J, Martí-Fábregas J, Martínez-Sánchez P, Molina C, Morales A, Nombela F, Purroy F, Rodríguez-Yañez M, Roquer J, Rubio F, Segura T, Serena J, Simal P, Tejada J, Vivancos J. Guidelines for the treatment of acute ischaemic stroke. NEUROLOGÍA (ENGLISH EDITION) 2014. [DOI: 10.1016/j.nrleng.2011.09.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Molecular Dissection of Cyclosporin A's Neuroprotective Effect Reveals Potential Therapeutics for Ischemic Brain Injury. Brain Sci 2013; 3:1325-56. [PMID: 24961531 PMCID: PMC4061870 DOI: 10.3390/brainsci3031325] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 07/30/2013] [Accepted: 08/14/2013] [Indexed: 12/02/2022] Open
Abstract
After the onset of brain ischemia, a series of events leads ultimately to the death of neurons. Many molecules can be pharmacologically targeted to protect neurons during these events, which include glutamate release, glutamate receptor activation, excitotoxicity, Ca2+ influx into cells, mitochondrial dysfunction, activation of intracellular enzymes, free radical production, nitric oxide production, and inflammation. There have been a number of attempts to develop neuroprotectants for brain ischemia, but many of these attempts have failed. It was reported that cyclosporin A (CsA) dramatically ameliorates neuronal cell damage during ischemia. Some researchers consider ischemic cell death as a unique process that is distinct from both apoptosis and necrosis, and suggested that mitochondrial dysfunction and Δψ collapse are key steps for ischemic cell death. It was also suggested that CsA has a unique neuroprotective effect that is related to mitochondrial dysfunction. Here, I will exhibit examples of neuroprotectants that are now being developed or in clinical trials, and will discuss previous researches about the mechanism underlying the unique CsA action. I will then introduce the results of our cDNA subtraction experiment with or without CsA administration in the rat brain, along with our hypothesis about the mechanism underlying CsA’s effect on transcriptional regulation.
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Turner RC, Dodson SC, Rosen CL, Huber JD. The science of cerebral ischemia and the quest for neuroprotection: navigating past failure to future success. J Neurosurg 2013; 118:1072-85. [PMID: 23331000 DOI: 10.3171/2012.11.jns12408] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ischemic stroke remains a leading cause of morbidity and death for which few therapeutic options are available. The development of neuroprotective agents, a once promising field of investigation, has failed to translate from bench to bedside successfully. This work reviews the ischemic cascade, agents targeting steps within the cascade, and potential reasons for lack of translation. Additional therapeutic targets are highlighted and areas requiring further investigation are discussed. It is clear that alternative targets need to be pursued, such as the role glia play in neurological injury and recovery, particularly the interactions between neurons, astrocytes, microglia, and the vasculature. Similarly, the biphasic nature of many signaling molecules such as matrix metalloproteinases and high-mobility group box 1 protein must be further investigated to elucidate periods of detrimental versus beneficial activity.
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Affiliation(s)
- Ryan C Turner
- Department of Neurosurgery, West Virginia University, Morgantown, West Virginia 26506-9183, USA
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Guidelines for the treatment of acute ischaemic stroke. Neurologia 2011; 29:102-22. [PMID: 22152803 DOI: 10.1016/j.nrl.2011.09.012] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Accepted: 09/11/2011] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION Update of Acute Ischaemic Stroke Treatment Guidelines of the Spanish Neurological Society based on a critical review of the literature. Recommendations are made based on levels of evidence from published data and studies. DEVELOPMENT Organized systems of care should be implemented to ensure access to the optimal management of all acute stroke patients in stroke units. Standard of care should include treatment of blood pressure (should only be treated if values are over 185/105 mmHg), treatment of hyperglycaemia over 155 mg/dl, and treatment of body temperature with antipyretic drugs if it rises above 37.5 °C. Neurological and systemic complications must be prevented and promptly treated. Decompressive hemicraniectomy should be considered in cases of malignant cerebral oedema. Intravenous thrombolysis with rtPA should be administered within 4.5 hours from symptom onset, except when there are contraindications. Intra-arterial pharmacological thrombolysis can be considered within 6 hours, and mechanical thrombectomy within 8 hours from onset, for anterior circulation strokes, while a wider window of opportunity up to 12-24 hours is feasible for posterior strokes. There is not enough evidence to recommend routine use of the so called neuroprotective drugs. Anticoagulation should be administered to patients with cerebral vein thrombosis. Rehabilitation should be started as early as possible. CONCLUSION Treatment of acute ischaemic stroke includes management of patients in stroke units. Systemic thrombolysis should be considered within 4.5 hours from symptom onset. Intra-arterial approaches with a wider window of opportunity can be an option in certain cases. Protective and restorative therapies are being investigated.
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Kamiya T, Abe K. [Future neuroprotective strategies in the post-thrombolysis era--neurovascular unit protection and vascular endothelial protection]. Rinsho Shinkeigaku 2011; 51:305-15. [PMID: 21706826 DOI: 10.5692/clinicalneurol.51.305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
From an appearance of recombinant tissue plasminogen activator (rt-PA) in the clinical therapy on 2005 in Japan, the therapeutic strategy of ischemic stroke therapy is now changing dramatically. Many experimental data from animal stroke and clinical trials of neuroprotective agents failed to clinical useful therapeutic strategy. A free radical scavenger, edaravone is the first clinical drug for neuroprotection in the world which has been used in almost all ischemic stroke patients in Japan from 2001. Now, it is especially useful in thrombolytic therapy with rtPA, whereas we still need the newly more effective neuroprotective drugs which can be applied to many ischemic stroke patients. Therefore, we review and describe the future neuroprotective strategies in the post-thrombolysis era.
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Abstract
AbstractNeuroprotection is a therapeutic strategy that attempts to save neurons from irreversible injury by modifying the effects of the ischemic cascade or facilitating reperfusion. Although numerous agents have shown neuroprotective effect in preclinical trials, their translation to clinical trials failed to show any meaningful effect. The Stroke Therapy Academic Industry Roundtable (STAIR) guidelines were made for performing research on neuroprotective agents in pre-clinical and clinical trials. Although the STAIR guidelines have been available for more than ten years, we still do not have any adequate neuroprotective agents. Reasons for unsuccessful translation from preclinical to clinical research can be considered along stages of drug development: 1) preclinical, 2) transitional and 3) clinical. By extending the therapeutic window for application of intravenous thrombolysis in acute stroke patients to 4.5 hours, as well as increasing the use intra-arterial thrombolysis and development of mechanical devices for thrombectomy in 6 hour period we may be able to achieve some degree of neuroprotection in acute stroke. Future therapy is likely to add to the current thrombolytic therapy with potential neuroprotective drugs or procedures.
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Gonzales NR, Grotta JC. Pharmacologic Modification of Acute Cerebral Ischemia. Stroke 2011. [DOI: 10.1016/b978-1-4160-5478-8.10053-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mandava P, Suarez JI, Kent TA. Intravenous rt-PA versus endovascular therapy for acute ischemic stroke. Curr Atheroscler Rep 2010; 10:332-8. [PMID: 18606104 DOI: 10.1007/s11883-008-0051-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The influence of baseline stroke severity on outcome makes comparisons between nonrandomized studies of intravenous and intra-arterial (IA) therapy problematic. Using pooled data from the placebo arms of randomized trials in acute ischemic stroke, we derived predictive functions for outcome. We then compared the outcomes from published trials to these functions. Net benefit was calculated by comparison of the individual study with the predicted outcome based on the therapeutic time window. Similar net benefit for IA therapy and intravenous therapy was found at 3 hours and 6 hours; a slight advantage for IA therapy was mitigated by an increase in mortality at 6 hours and by publication bias. No net benefit for IA therapy was shown in the time window greater than 6 hours. Conclusive evidence for the superiority of either therapy awaits prospective randomized trials.
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Qureshi AI, Tariq N, Vazquez G, Novitzke J, Suri MFK, Lakshminarayan K, Haines SJ. Low patient enrollment sites in multicenter randomized clinical trials of cerebrovascular diseases: associated factors and impact on trial outcomes. J Stroke Cerebrovasc Dis 2010; 21:131-42. [PMID: 20719541 DOI: 10.1016/j.jstrokecerebrovasdis.2010.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 05/19/2010] [Accepted: 05/29/2010] [Indexed: 11/19/2022] Open
Abstract
Wide variability in patient enrollment among participating sites is a common phenomenon in multicenter trials. We examined stroke trial-related factors associated with the proportion of sites with low patient enrollment and the effect of these low-enrollment sites on trial outcome. We identified efficacy clinical trials enrolling patients with cerebrovascular diseases between 1980 and 2008 using an electronic database. The trials included in our analyses were multicenter randomized controlled trials (RCTs) comparing efficacy endpoints between two or more treatment groups and having >5 sites. Sites enrolling <10 patients or <2% of total trial patients were defined as low- enrollment sites. Trials were classified into tertiles based on the proportion of low-enrollment sites. Factors associated with trials that could be ascertained through a systematic review of published data were identified and examined. The association between low enrollment and a conclusive trial designation (defined by the ability to reject the primary null hypothesis either at or before target enrollment or demonstrate equivalence/noninferiority with adequate statistical power, depending on the initial design) was assessed using a multivariate logistic regression model. We identified 51 trials that met the inclusion criteria and provided information regarding patients enrolled per center. A total of 3059 participating centers enrolled a total of 53,742 trial participants; 78% of the participating sites enrolled <2% of trial participants. Trials enrolling acute stroke patients (within 24 hours of symptom onset) or those evaluating endovascular/surgical intervention had a higher proportion of low-enrollment sites (<10 patients per site). Studies with a higher proportion of low-enrollment sites were more likely to target acute stroke patients and less likely to randomize ≥1000 patients, use general efficacy endpoints, and stratify by site. There was no association between the studies with a higher proportion of low-enrollment sites and designation as a conclusive trial. A better understanding of factors associated with low-enrollment sites in clinical trials and the impact on a trial's ability to demonstrate conclusive outcomes may lead to strategies to make trial enrollments more efficient and cost-effective.
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Affiliation(s)
- Adnan I Qureshi
- Zeenat Qureshi Stroke Research Center, Department of Neurology, University of Minnesota, Minneapolis, MN, USA.
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Chacon MR, Jensen MB, Sattin JA, Zivin JA. Neuroprotection in cerebral ischemia: emphasis on the SAINT trial. Curr Cardiol Rep 2008; 10:37-42. [PMID: 18416999 DOI: 10.1007/s11886-008-0008-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Acute ischemic stroke (AIS) is a significant cause of death and disability in the United States. It has been 10 years since tissue plasminogen activator became the first medication approved by the US Food and Drug Administration for treatment for AIS. However, this treatment simply reopens arteries. The identification of deleterious cellular reactions that occur secondary to cerebral ischemia has led investigators to search for neuroprotection strategies to complement reperfusion. More than 100 human trials, including a handful of phase III trials, had failed to produce an efficacious neuroprotective agent. In 2006, the first positive trial of neuroprotection was published: the SAINT I (Stroke-Acute Ischemic NXY Treatment) study. In February 2008, the SAINT II study was published, indicating that NXY-059 was not effective for AIS treatment.
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Affiliation(s)
- Marcus R Chacon
- Department of Neurosciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0624, USA
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Ginsberg MD. Neuroprotection for ischemic stroke: past, present and future. Neuropharmacology 2008; 55:363-89. [PMID: 18308347 DOI: 10.1016/j.neuropharm.2007.12.007] [Citation(s) in RCA: 535] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 12/03/2007] [Accepted: 12/06/2007] [Indexed: 12/30/2022]
Abstract
Neuroprotection for ischemic stroke refers to strategies, applied singly or in combination, that antagonize the injurious biochemical and molecular events that eventuate in irreversible ischemic injury. There has been a recent explosion of interest in this field, with over 1000 experimental papers and over 400 clinical articles appearing within the past 6 years. These studies, in turn, are the outgrowth of three decades of investigative work to define the multiple mechanisms and mediators of ischemic brain injury, which constitute potential targets of neuroprotection. Rigorously conducted experimental studies in animal models of brain ischemia provide incontrovertible proof-of-principle that high-grade protection of the ischemic brain is an achievable goal. Nonetheless, many agents have been brought to clinical trial without a sufficiently compelling evidence-based pre-clinical foundation. At this writing, around 160 clinical trials of neuroprotection for ischemic stroke have been initiated. Of the approximately 120 completed trials, two-thirds were smaller early-phase safety-feasibility studies. The remaining one-third were typically larger (>200 subjects) phase II or III trials, but, disappointingly, only fewer than one-half of these administered neuroprotective therapy within the 4-6h therapeutic window within which efficacious neuroprotection is considered to be achievable. This fact alone helps to account for the abundance of "failed" trials. This review presents a close survey of the most extensively evaluated neuroprotective agents and classes and considers both the strengths and weakness of the pre-clinical evidence as well as the results and shortcomings of the clinical trials themselves. Among the agent-classes considered are calcium channel blockers; glutamate antagonists; GABA agonists; antioxidants/radical scavengers; phospholipid precursor; nitric oxide signal-transduction down-regulator; leukocyte inhibitors; hemodilution; and a miscellany of other agents. Among promising ongoing efforts, therapeutic hypothermia, high-dose human albumin therapy, and hyperacute magnesium therapy are considered in detail. The potential of combination therapies is highlighted. Issues of clinical-trial funding, the need for improved translational strategies and clinical-trial design, and "thinking outside the box" are emphasized.
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Affiliation(s)
- Myron D Ginsberg
- Department of Neurology (D4-5), University of Miami Miller School of Medicine, Miami, FL 33101, USA.
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Shimogori H, Takemoto T, Mikuriya T, Yamashita H. Edaravone protects the vestibular periphery from free radical-induced toxicity in response to perilymphatic application of (±)-α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid. Eur J Pharmacol 2007; 554:223-8. [PMID: 17109855 DOI: 10.1016/j.ejphar.2006.10.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Revised: 10/01/2006] [Accepted: 10/05/2006] [Indexed: 11/21/2022]
Abstract
Intracochlear infusion of (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) was performed with a syringe pump in guinea pigs, and peripheral vestibular dysfunction was induced. Animals were administered edaravone systemically or topically. In the systemic application group, animals were administered edaravone once a day for 7 days after AMPA infusion. In the topical application group, edaravone-soaked gelfoam was placed on the round window membrane just after, 12 h after or 24 h after AMPA infusion. Spontaneous nystagmus was observed after AMPA infusion. Immunohistochemistry for 4-hydroxy-2-nonenal (4-HNE), a marker of free radical-induced lipid peroxidation, was performed 24 h after AMPA infusion. In addition, caloric tests were performed to evaluate vestibular function 1 week after AMPA infusion. Animals in both groups showed decreased spontaneous nystagmus, but results were not significant. Animals treated topically with edaravone within 12 h of AMPA infusion showed normal morphology of the ampullar sensory epithelia of the lateral semicircular canals and showed a good response to the caloric tests. 4-HNE immunoreactivity in the sensory epithelia was very low in these animals. In contrast, untreated animals and animals treated with edaravone systemically or topically 24 h after AMPA infusion showed morphologic hair cell damage, reduced caloric response and remarkable 4-HNE immunoreactivity in the sensory epithelia. These results indicate that topical application of edaravone within 12 h after damage protects the vestibular periphery from free radical-induced toxicity in response to intracochlear infusion of AMPA.
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Affiliation(s)
- Hiroaki Shimogori
- Department of Otolaryngology, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan.
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Abstract
After years of setbacks, the perspective of neuroprotective stroke therapy has revived in light of recent study results. We outline in this review how a neuroprotective candidate drug should be developed, beginning with a thorough preclinical evaluation according to the STAIR (Stroke Therapy Academic Industry Roundtable) criteria. Assessing the safety of the candidate drug in the relatively straightforward Phase IIA would be the first step into clinical development. While advancing into Phase IIB, the implementation of a responder analysis, the use of a surrogate biomarker as well as the use of Bayesian methodology should be considered to increase the likelihood of seeing any therapeutic sign. Clinical development in Phase III should consider that previously used dichotomized endpoints appropriate for evaluation of thrombolytic drugs are likely to be insufficient for assessing efficacy of neuroprotective drugs. Detection of a clinically relevant shift in the outcome measure appears to be a more relevant approach for the type of drug that achieves a reduction and not a reverse of the ischaemic lesion.
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Affiliation(s)
- W-R Schäbitz
- Department of Neurology, University of Münster, Albert-Schweitzer-Strasse 33, 48129 Münster, Germany.
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Muir KW, Teal PA. Why have neuroprotectants failed? J Neurol 2005; 252:1011-20. [PMID: 16133726 DOI: 10.1007/s00415-005-0933-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Revised: 09/03/2004] [Accepted: 04/22/2005] [Indexed: 11/28/2022]
Affiliation(s)
- K W Muir
- University of Glasgow, Division of Clinical Neurosciences, Institute of Neurological Sciences Southern General Hospital, Glasgow G51 4TF, Scotland
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Cheng YD, Al-Khoury L, Zivin JA. Neuroprotection for ischemic stroke: two decades of success and failure. NeuroRx 2005; 1:36-45. [PMID: 15717006 PMCID: PMC534911 DOI: 10.1602/neurorx.1.1.36] [Citation(s) in RCA: 270] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Alteplase (rt-PA) is the first therapy successfully developed for acute stroke therapy. The success of rt-PA spurred development of new avenues for acute stroke management. For the last two decades, a great deal of attention has been paid to neuroprotective therapies. Initial preclinical studies demonstrated numerous drugs are effective for treating acute stroke in animal models; however, subsequent clinical trials have been frustrating, and none of the agents has proven effective. The various outcomes of preclinical and clinical trials have been the subject of much discussion. In this article, we review some key neuroprotective trials and the possible reasons for their failures. By identifying the discrepancies between preclinical studies and clinical trials, we may be able to set guidelines for future effective trials.
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Affiliation(s)
- Yu Dennis Cheng
- Stroke Center, University of California School of Medicine, and University of California San Diego, La Jolla, California, 92093-0624, USA
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Abstract
Stroke is the third leading cause of death and the leading cause of disability in developed countries, yet remains a poorly treated condition. Treatments for stroke can be aimed at acutely improving blood flow or protecting brain tissue against ischaemia, enhancing stroke recovery or reducing the risk of stroke recurrence. This paper reviews each of these approaches, particularly focusing on mechanisms for which there are agents in clinical trials. There are a number of appealing neuroprotective agents in Phase II and III clinical trials. However, the majority of acute treatments are likely to suffer from a narrow therapeutic time window and hence limited patient access. Combinations of acute approaches are likely to offer the greatest benefit, but present challenges in development. Promotion of recovery following stroke offers enormous potential for successful therapeutic intervention. Excitingly, new developments in preclinical research have identified possible ways in which this may be achieved.
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Affiliation(s)
- Isabel J Beresford
- Neurology & GI Centre of Excellence for Drug Discovery, GlaxoSmithKline Research & Development Ltd, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, UK.
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Geer EB, Landman RE, Wardlaw SL, Conwell IM, Freda PU. Stimulation of the hypothalamic-pituitary-adrenal axis with the opioid antagonist nalmefene. Pituitary 2005; 8:115-22. [PMID: 16379031 DOI: 10.1007/s11102-005-5227-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
UNLABELLED Nalmefene Stimulation of the HPA Axis. BACKGROUND The Hypothalamic-pituitary-adrenal (HPA) axis plays a vital role in the body's response to stress. The traditional gold standard for evaluating the HPA axis, the insulin hypoglycemia test (IHT), has several known limitations, and a second test, the standard ACTH stimulation test, can detect severe deficiencies of cortisol, but often misses mild or early cases. Therefore, a better test for the evaluation of the HPA axis is needed. This study evaluated the opiate antagonist nalmefene as a stimulation test of the HPA axis. METHODS 25 healthy subjects were studied, 9 women and 16 men, mean age 30.4 yr. (range 21-55), and mean BMI 24.1 kg/m2 (range 18.6-34.2). Subjects received one of 3 doses of intravenously administered nalmefene: 2 mg (n = 6), 6 mg (n = 12), or 10 mg (n = 7). Serum cortisol and plasma ACTH were measured before and serially over two hours after the administration of nalmefene. RESULTS ACTH and cortisol levels rose significantly and similarly after the 10 mg dose and the 6 mg dose. After the 10 mg dose, mean peak ACTH was 82.4 +/- 22.6 pg/ml and mean peak cortisol was 25.2 +/- 1.8 microg/dl. After the 6 mg dose, mean peak ACTH was 70.3 +/- 7.7 pg/ml and mean peak cortisol was 24.7 +/- 1.7 microg/dl. Cortisol levels rose above 18 microg/dl in all subjects receiving 10 mg of nalmefene, and in all but two of the subjects receiving 6 mg of nalmefene. Side effects to nalmefene were of greater duration and intensity in the subjects receiving 10 mg of nalmefene vs. those receiving 6 or 2 mg. These included most notably fatigue, lightheadedness, nausea and vomiting. CONCLUSIONS Of the nalmefene doses we studied, 6 mg achieved the best combination of stimulation of ACTH and cortisol and fewest side effects. If further studies show a concordance between nalmefene and IHT, nalmefene testing could be used to assess the HPA axis in patients at risk for dysfunction of this axis.
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Affiliation(s)
- Eliza B Geer
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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Abstract
The pathophysiology of cerebral ischemia is best understood in animal models of stroke. Within minutes of interrupted blood flow, mitochondria are deprived of substrate, which prevents adenosine triphosphate generation and results in membrane depolarization. This leads to increased intracellular calcium and sodium concentration followed by generation of free radicals and initiation of apoptosis. Glutamate release from ischemic neurons contributes to cellular damage. Each step in this complex, interdependent series of events offers a potential point to intervene and prevent neuronal death. Although many human trials in acute stroke therapy have had disappointing results, many promising therapies are in the pipeline, including hypothermia and free-radical inhibitors. Herein, the author discusses the pathophysiology of focal cerebral ischemia as has been revealed in rodent models and reviews the major human trials according to treatment mechanism.
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Affiliation(s)
- Wade S Smith
- Department of Neurology, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, California 94143-0114, USA.
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Ralph GS, Parham S, Lee SR, Beard GL, Craigon MH, Ward N, White JR, Barber RD, Rayner W, Kingsman SM, Mundy CR, Mazarakis ND, Krige D. Identification of potential stroke targets by lentiviral vector mediated overexpression of HIF-1 alpha and HIF-2 alpha in a primary neuronal model of hypoxia. J Cereb Blood Flow Metab 2004; 24:245-58. [PMID: 14747751 DOI: 10.1097/01.wcb.0000110532.48786.46] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The identification of genes differentially regulated by ischemia will lead to an improved understanding of cell death pathways such as those involved in the neuronal loss observed following a stroke. Furthermore, the characterization of such pathways could facilitate the identification of novel targets for stroke therapy. We have used a novel approach to amplify differential gene expression patterns in a primary neuronal model of stroke by employing a lentiviral vector system to specifically bias the transcriptional activation of hypoxically regulated genes. Overexpression of the hypoxia-induced transcription factor subunits HIF-1 alpha and HIF-2 alpha elevated hypoxia-mediated transcription of many known HIF-regulated genes well above control levels. Furthermore, many potentially novel HIF-regulated genes were discovered that were not previously identified as hypoxically regulated. Most of the novel genes identified were activated by a combination of HIF-2 alpha overexpression and hypoxic insult. These included several genes with particular importance in cell survival pathways and of potential therapeutic value. Hypoxic induction of HIF-2 alpha may therefore be a critical factor in mediating protective responses against ischemic injury. Further investigation of the genes identified in this study may provide increased understanding of the neuronal response to hypoxia and may uncover novel therapeutic targets for the treatment of cerebral ischemia.
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Pharmacologic Modification of Acute Cerebral Ischemia. Stroke 2004. [DOI: 10.1016/b0-44-306600-0/50061-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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40
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Clinical trials for cytoprotection in stroke. Neurotherapeutics 2004. [DOI: 10.1007/bf03206567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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41
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Abstract
To date, many cytoprotective drugs have reached the stage of pivotal phase 3 efficacy trials in acute stroke patients. (Table 1) Unfortunately, throughout the neuroprotective literature, the phrase "failure to demonstrate efficacy" prevails as a common thread among the many neutral or negative trials, despite the largely encouraging results encountered in preclinical studies. The reasons for this discrepancy are multiple, and have been discussed by Dr. Zivin in his review. Many of the recent trials have addressed deficiencies of the previous ones with more rigorous trial design, including more specific patient selection criteria (ensure homogeneity of stroke location and severity), stratified randomization algorithms (time-to-treat), narrowed therapeutic time-window and pharmacokinetic monitoring. Current trials have also incorporated biologic surrogate markers of toxicity and outcome such as drug levels and neuroimaging. Lastly, multi-modal therapies and coupled cytoprotection/reperfusion strategies are being investigated to optimize tissue salvage. This review will focus on individual therapeutic strategies and we will emphasize what we have learned from these trials both in terms of trial design and the biologic effect (or lack thereof) of these agents.
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Affiliation(s)
- Lise A Labiche
- Stroke Program, University of Texas at Houston Medical School, 6431 Fannin Street, Houston, Texas 77030, USA
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42
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Richard Green A, Odergren T, Ashwood T. Animal models of stroke: do they have value for discovering neuroprotective agents? Trends Pharmacol Sci 2003; 24:402-8. [PMID: 12915049 DOI: 10.1016/s0165-6147(03)00192-5] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There has been a series of high-profile failures of drugs in clinical trials of acute ischaemic stroke that were designed to meet criteria necessary for drug regulatory approval. This has, again, called into question the value of animal models for identifying effective neuroprotective agents. Here, we review evidence that physiological changes (reperfusion, hyperglycaemia, hypothermia and blood pressure) produce comparable changes in outcome in both animal models and human stroke patients, which indicates that the models should identify clinically effective neuroprotective agents. We suggest that most clinical failures have occurred because compounds were administered differently in animal and clinical studies. We review earlier guidelines on the information that is necessary from preclinical studies before a compound enters clinical trials, and propose modifications to these guidelines.
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43
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Weinberger J, Frishman WH, Terashita D. Drug therapy of neurovascular disease. Cardiol Rev 2003; 11:122-46. [PMID: 12705843 DOI: 10.1097/01.crd.0000053459.09918.92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent advances in the prevention and pharmacotherapy of cerebrovascular disease have provided more favorable clinical outcomes. For the treatment of an acute ischemic stroke, the early use of thrombolytic agents can reduce the degree of brain damage while improving functional outcomes. However, trials evaluating various classes of other neuroprotective agents have not shown benefit to date. For the prevention of second stroke, the use of antiplatelet drugs, HMG-CoA reductase inhibitors, and angiotensin-converting enzyme inhibitors with a diuretic have shown benefit in reducing new events. In patients with underlying heart disease or atrial fibrillation, warfarin appears to be the drug of choice in preventing stroke. Early treatment of hemorrhagic stroke with calcium channel blockers can improve the functional outcome. Innovative therapies are now available for the treatment of migraine and vascular dementia. Primary prevention of stroke remains the optimal therapeutic strategy and includes treatment of systemic hypertension and hypercholesterolemia.
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Affiliation(s)
- Jesse Weinberger
- Department of Neurology, Mt. Sinai Medical Center, New York, New York, USA.
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44
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Abstract
Neurologic complications from cerebral ischemia occur frequently following cardiac arrest, as well as in the perioperative period in cardiac surgery. The cellular and molecular mechanisms of cerebral ischemia are complex. This article discusses several important cell death and salvage pathways that are important in experimental cerebral ischemia that may be critical to outcome in clinical brain injury.
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Affiliation(s)
- Anish Bhardwaj
- Meyer 8-140, Neuroscience Critical Care Division, Johns Hopkins Hospital, 600 N. Wolfe Street, Baltimore, MD 21287, USA.
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45
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Ovbiagele B, Kidwell CS, Starkman S, Saver JL. Neuroprotective agents for the treatment of acute ischemic stroke. Curr Neurol Neurosci Rep 2003; 3:9-20. [PMID: 12507405 DOI: 10.1007/s11910-003-0031-z] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Neuroprotective treatments are therapies designed to interrupt the cellular, biochemical, and metabolic elaboration of injury during or following exposure to ischemia; they encompass a rapidly expanding array of pharmacologic interventions. Various classes of neuroprotective agents have reached phase III efficacy trials in focal ischemic stroke, but none has proven effective, despite successful preceding animal studies. This notwithstanding, recent favorable results of hypothermia in human cardiac arrest trials have validated the general concept of neuroprotection. In addition, the promise of neuroprotective therapy for focal acute ischemic stroke has been renewed by innovations in strategies of preclinical drug development and clinical trial design that rectify past defects, including trial testing of combination therapies rather than single agents and novel approaches to accelerating time to initiation of experimental treatment.
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Affiliation(s)
- Bruce Ovbiagele
- Stroke Center and Department of Neurology, University of California at Los Angeles, 710 Westwood Plaza, Los Angeles, CA 90095, USA.
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46
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Bates S, Read SJ, Harrison DC, Topp S, Morrow R, Gale D, Murdock P, Barone FC, Parsons AA, Gloger IS. Characterisation of gene expression changes following permanent MCAO in the rat using subtractive hybridisation. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2001; 93:70-80. [PMID: 11532340 DOI: 10.1016/s0169-328x(01)00186-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Failure of several putative neuroprotectants in large multicentred clinical trials has re-focussed attention on the predictability of pre-clinical animal models of stroke. Model characterisation and relationship to heterogeneous patient sub-groups remains of paramount importance. Information gained from magnetic resonance imaging (MRI) signatures indicates that the Zea Longa model of rat middle cerebral artery occlusion may be more representative of slowly evolving infarcts. Understanding the molecular changes over several hours following cerebral ischaemia will allow detailed characterisation of the adaptive response to brain injury. Using a fully characterised model of Zea Longa middle cerebral artery occlusion we have used the representational difference analysis (RDA) subtractive hybridisation method to identify transcripts that accumulate in the ischaemic cortex. Along with a number of established ischaemia-induced gene products (including MCP-1, TIMP-1, hsp 70) we were also able to identify nine genes which have not previously been shown to accumulate following focal ischaemia (including SOCS-3, GADD45gamma, Xin).
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Affiliation(s)
- S Bates
- Department of Molecular Biology, GlaxoSmithKline Pharmaceuticals, New Frontiers Science Park, Harlow, Essex, UK.
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47
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Read SJ, Parsons AA, Harrison DC, Philpott K, Kabnick K, O' Brien S, Clark S, Brawner M, Bates S, Gloger I, Legos JJ, Barone FC. Stroke genomics: approaches to identify, validate, and understand ischemic stroke gene expression. J Cereb Blood Flow Metab 2001; 21:755-78. [PMID: 11435788 DOI: 10.1097/00004647-200107000-00001] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sequencing of the human genome is nearing completion and biologists, molecular biologists, and bioinformatics specialists have teamed up to develop global genomic technologies to help decipher the complex nature of pathophysiologic gene function. This review will focus on differential gene expression in ischemic stroke. It will discuss inheritance in the broader stroke population, how experimental models of spontaneous stroke might be applied to humans to identify chromosomal loci of increased risk and ischemic sensitivity, and also how the gene expression induced by stroke is related to the poststroke processes of brain injury, repair, and recovery. In addition, we discuss and summarise the literature of experimental stroke genomics and compare several approaches of differential gene expression analyzes. These include a comparison of representational difference analysis we have provided using an experimental stroke model that is representative of stroke evolution observed most often in man, and a summary of available data on stroke differential gene expression. Issues regarding validation of potential genes as stroke targets, the verification of message translation to protein products, the relevance of the expression of neuroprotective and neurodestructive genes and their specific timings, and the emerging problems of handling novel genes that may be discovered during differential gene expression analyses will also be addressed.
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Affiliation(s)
- S J Read
- Neurology Center of Excellence for Drug Discovery, GlaxoSmithKline, Harlow, UK
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48
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Lutsep HL, Clark WM. Current status of neuroprotective agents in the treatment of acute ischemic stroke. Curr Neurol Neurosci Rep 2001; 1:13-8. [PMID: 11898495 DOI: 10.1007/s11910-001-0072-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
To keep ischemic brain cells alive, neuroprotective agents target events in the ischemic cascade that might be injurious to the cells. They can be divided broadly into groups that restore ion balance, block receptors, prevent reperfusion injury, or promote neuronal healing. To date, neuroprotective agents have either shown a lack of efficacy in clinical stroke trials or been limited by side effects. Ongoing clinical trials with novel agents are trying to enroll a more homogeneous population of stroke patients in an effort to demonstrate treatment benefit.
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Affiliation(s)
- H L Lutsep
- Oregon Stroke Center, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, CR 131, Portland, OR 97201, USA.
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