1
|
Santo BA, Jenkins TD, Ciecierska SSK, Baig AA, Levy EI, Siddiqui AH, Tutino VM. MicroCT and Histological Analysis of Clot Composition in Acute Ischemic Stroke : A Comparative Study of MT-Retrieved Clots and Clot Analogs. Clin Neuroradiol 2024; 34:431-439. [PMID: 38294532 DOI: 10.1007/s00062-023-01380-1] [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] [Received: 08/04/2023] [Accepted: 12/26/2023] [Indexed: 02/01/2024]
Abstract
PURPOSE Assessing clot composition on prethrombectomy computed tomography (CT) imaging may help in stroke treatment planning. In this study we seek to use microCT imaging of fabricated blood clots to understand the relationship between CT radiographic signals and the biological makeup. METHODS Clots (n = 10) retrieved by mechanical thrombectomy (MT) were collected, and 6 clot analogs of varying RBC composition were made. We performed paired microCT and histological image analysis of all 16 clots using a ScanCo microCT 100 (4.9 µm resolution) and standard H&E staining (imaged at 40×). From these data types, first order statistic (FOS) radiomics were computed from microCT, and percent composition of RBCs (%RBC) was computed from histology. Polynomial and linear regression (LR) were used to build statistical models based on retrieved thrombus microCT and %RBC that were evaluated for their ability to predict the %RBC of clot analogs from mean HU. Correlation analyses of microCT FOS with composition were completed for both retrieved clots and analogs. RESULTS The LR model fits relating MT-retrieved clot %RBC with mean (R2 = 0.625, p = 0.006) and standard deviation (R2 = 0.564, p < 0.05) in HUs on microCT were significant. Similarly, LR models relating analog histological %RBC to analog protocol %RBC (R2 = 0.915, p = 0.003) and mean HUs on microCT (R2 = 0.872, p = 0.007) were also significant. When the LR model built using MT-retrieved clots was used to predict analog %RBC from mean HUs, significant correlation was observed between predictions and actual histological %RBC (R2 = 0.852, p = 0.009). For retrieved clots, significant correlations were observed for energy and total energy with %RBC and %FP (|R| > 0.7, q < 0.01). Analogs further demonstrated significant correlation between FOS energy, total energy, variance and %WBC (|R| > 0.9, q < 0.01). CONCLUSION MicroCT can be used to build models that predict AIS clot composition from routine CT parameters and help us to better understand radiomic signatures associated with clot composition and first pass outcomes. In future work, such observations can be used to better infer clot composition and inform thrombectomy prognostics from pretreatment CTs.
Collapse
Affiliation(s)
- Briana A Santo
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY, USA
| | - TaJania D Jenkins
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Shiau-Sing K Ciecierska
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA
| | - Ammad A Baig
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY, USA
| | - Elad I Levy
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY, USA
| | - Adnan H Siddiqui
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY, USA
| | - Vincent M Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, 875 Ellicott Street, 14203, Buffalo, NY, USA.
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY, USA.
- Department of Neurosurgery, University at Buffalo, Buffalo, NY, USA.
| |
Collapse
|
2
|
Huang Y, Gu S, Han Z, Yang Z, Zhong L, Li L, Wang R, Yan F, Luo Y, Borlongan C, Lu J. Cold Case of Thrombolysis: Cold Recombinant Tissue Plasminogen Activator Confers Enhanced Neuroprotection in Experimental Stroke. J Am Heart Assoc 2023; 12:e029817. [PMID: 37655472 PMCID: PMC10547350 DOI: 10.1161/jaha.123.029817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023]
Abstract
Background Thrombolysis and endovascular thrombectomy are the primary treatment for ischemic stroke. However, due to the limited time window and the occurrence of adverse effects, only a small number of patients can genuinely benefit from recanalization. Intraarterial injection of rtPA (recombinant tissue plasminogen activator) based on arterial thrombectomy could improve the prognosis of patients with acute ischemic stroke, but it could not reduce the incidence of recanalization-related adverse effects. Recently, selective brain hypothermia has been shown to offer neuroprotection against stroke. To enhance the recanalization rate of ischemic stroke and reduce the adverse effects such as tiny thrombosis, brain edema, and hemorrhage, we described for the first time a combined approach of hypothermia and thrombolysis via intraarterial hypothermic rtPA. Methods and Results We initially established the optimal regimen of hypothermic rtPA in adult rats subjected to middle cerebral artery occlusion. Subsequently, we explored the mechanism of action mediating hypothermic rtPA by probing reduction of brain tissue temperature, attenuation of blood-brain barrier damage, and sequestration of inflammation coupled with untargeted metabolomics. Hypothermic rtPA improved neurological scores and reduced infarct volume, while limiting hemorrhagic transformation in middle cerebral artery occlusion rats. These therapeutic outcomes of hypothermic rtPA were accompanied by reduced brain temperature, glucose metabolism, and blood-brain barrier damage. A unique metabolomic profile emerged in hypothermic rtPA-treated middle cerebral artery occlusion rats characterized by downregulated markers for energy metabolism and inflammation. Conclusions The innovative use of hypothermic rtPA enhances their combined, as opposed to stand-alone, neuroprotective effects, while reducing hemorrhagic transformation in ischemic stroke.
Collapse
Affiliation(s)
- Yuyou Huang
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
| | - Shanshan Gu
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
| | - Ziping Han
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
| | - Zhenghong Yang
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
| | - Liyuan Zhong
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
| | - Lingzi Li
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
| | - Rongliang Wang
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
- Beijing Key Laboratory of Translational Medicine for Cerebrovascular DiseasesBeijingChina
| | - Feng Yan
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
- Beijing Key Laboratory of Translational Medicine for Cerebrovascular DiseasesBeijingChina
| | - Yumin Luo
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
- Beijing Key Laboratory of Translational Medicine for Cerebrovascular DiseasesBeijingChina
- Beijing Institute for Brain DisordersBeijingChina
| | | | - Jie Lu
- Department of Radiology and Nuclear Medicine, Institute of Cerebrovascular Diseases ResearchXuanwu Hospital of Capital Medical UniversityBeijingChina
- Beijing Institute for Brain DisordersBeijingChina
| |
Collapse
|
3
|
Santo BA, Ciecierska SSK, Mousavi Janbeh Sarayi SM, Jenkins TD, Baig AA, Monteiro A, Koenigsknecht C, Pionessa D, Gutierrez L, King RM, Gounis M, Siddiqui AH, Tutino VM. Tectonic infarct analysis: A computational tool for automated whole-brain infarct analysis from TTC-stained tissue. Heliyon 2023; 9:e14837. [PMID: 37025889 PMCID: PMC10070917 DOI: 10.1016/j.heliyon.2023.e14837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/06/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023] Open
Abstract
Background Infarct volume measured from 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain slices is critical to in vivo stroke models. In this study, we developed an interactive, tunable, software that automatically computes whole-brain infarct metrics from serial TTC-stained brain sections. Methods Three rat ischemic stroke cohorts were used in this study (Total n = 91 rats; Cohort 1 n = 21, Cohort 2 n = 40, Cohort 3 n = 30). For each, brains were serially-sliced, stained with TTC and scanned on both anterior and posterior sides. Ground truth annotation and infarct morphometric analysis (e.g., brain-Vbrain, infarct-Vinfarct, and non-infarct-Vnon-infarct volumes) were completed by domain experts. We used Cohort 1 for brain and infarct segmentation model development (n = 3 training cases with 36 slices [18 anterior and posterior faces], n = 18 testing cases with 218 slices [109 anterior and posterior faces]), as well as infarct morphometrics automation. The infarct quantification pipeline and pre-trained model were packaged as a standalone software and applied to Cohort 2, an internal validation dataset. Finally, software and model trainability were tested as a use-case with Cohort 3, a dataset from a separate institute. Results Both high segmentation and statistically significant quantification performance (correlation between manual and software) were observed across all datasets. Segmentation performance: Cohort 1 brain accuracy = 0.95/f1-score = 0.90, infarct accuracy = 0.96/f1-score = 0.89; Cohort 2 brain accuracy = 0.97/f1-score = 0.90, infarct accuracy = 0.97/f1-score = 0.80; Cohort 3 brain accuracy = 0.96/f1-score = 0.92, infarct accuracy = 0.95/f1-score = 0.82. Infarct quantification (cohort average): Vbrain (ρ = 0.87, p < 0.001), Vinfarct (0.92, p < 0.001), Vnon-infarct (0.80, p < 0.001), %infarct (0.87, p = 0.001), and infarct:non-infact ratio (ρ = 0.92, p < 0.001). Conclusion Tectonic Infarct Analysis software offers a robust and adaptable approach for rapid TTC-based stroke assessment.
Collapse
|
4
|
Alam JJ, Krakovsky M, Germann U, Levy A. Continuous administration of a p38α inhibitor during the subacute phase after transient ischemia-induced stroke in the rat promotes dose-dependent functional recovery accompanied by increase in brain BDNF protein level. PLoS One 2020; 15:e0233073. [PMID: 33275615 PMCID: PMC7717516 DOI: 10.1371/journal.pone.0233073] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 11/20/2020] [Indexed: 12/17/2022] Open
Abstract
There is unmet need for effective stroke therapies. Numerous neuroprotection attempts for acute cerebral ischemia have failed and as a result there is growing interest in developing therapies to promote functional recovery through increasing synaptic plasticity. For this research study, we hypothesized that in addition to its previously reported role in mediating cell death during the acute phase, the alpha isoform of p38 mitogen-activated protein kinase, p38α, may also contribute to interleukin-1β-mediated impairment of functional recovery during the subacute phase after acute ischemic stroke. Accordingly, an oral, brain-penetrant, small molecule p38α inhibitor, neflamapimod, was evaluated as a subacute phase stroke treatment to promote functional recovery. Neflamapimod administration to rats after transient middle cerebral artery occlusion at two dose levels was initiated outside of the previously characterized therapeutic window for neuroprotection of less than 24 hours for p38α inhibitors. Six-week administration of neflamapimod, starting at 48 hours after reperfusion, significantly improved behavioral outcomes assessed by the modified neurological severity score at Week 4 and at Week 6 post stroke in a dose-dependent manner. Neflamapimod demonstrated beneficial effects on additional measures of sensory and motor function. It also resulted in a dose-related increase in brain-derived neurotrophic factor (BDNF) protein levels, a previously reported potential marker of synaptic plasticity that was measured in brain homogenates at sacrifice. Taken together with literature evidence on the role of p38α-dependent suppression by interleukin-1β of BDNF-mediated synaptic plasticity and BDNF production, our findings support a mechanistic model in which inhibition of p38α promotes functional recovery after ischemic stroke by blocking the deleterious effects of interleukin-1β on synaptic plasticity. The dose-related in vivo efficacy of neflamapimod offers the possibility of having a therapy for stroke that could be initiated outside the short time window for neuroprotection and for improving recovery after a completed stroke.
Collapse
Affiliation(s)
- John J. Alam
- EIP Pharma, Inc., Boston, Massachusetts, United States of America
- * E-mail:
| | | | - Ursula Germann
- EIP Pharma, Inc., Boston, Massachusetts, United States of America
| | | |
Collapse
|
5
|
Abstract
Stroke remains a leading cause of disability and death worldwide despite significant scientific and therapeutic advances. Therefore, there is a critical need to improve stroke prevention and treatment. In this review, we describe several examples that leverage nucleic acid therapeutics to improve stroke care through prevention, acute treatment, and recovery. Aptamer systems are under development to increase the safety and efficacy of antithrombotic and thrombolytic treatment, which represent the mainstay of medical stroke therapy. Antisense oligonucleotide therapy has shown some promise in treating stroke causes that are genetically determined and resistant to classic prevention approaches such as elevated lipoprotein (a) and cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Targeting microRNAs may be attractive because they regulate factors involved in neuronal cell death and reperfusion-associated injury, as well as neurorestorative pathways. Lastly, microRNAs may aid reliable etiologic classification of stroke subtypes, which is important for effective secondary stroke prevention.
Collapse
Affiliation(s)
- Nils Henninger
- Department of Neurology, University of Massachusetts Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
- Department of Psychiatry, University of Massachusetts Medical School, 55 Lake Ave, North, Worcester, MA, 01655, USA.
| | - Yunis Mayasi
- Division of Neurocritical Care, Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, 600 N. Wolfe Street, Baltimore, MD, 21287, USA
| |
Collapse
|
6
|
Chuang BTC, Liu X, Lundberg AJ, Toung TJK, Ulatowski JA, Koehler RC. Refinement of embolic stroke model in rats: Effect of post-embolization anesthesia duration on arterial blood pressure, cerebral edema and mortality. J Neurosci Methods 2018; 307:8-13. [PMID: 29935198 DOI: 10.1016/j.jneumeth.2018.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 11/18/2022]
Abstract
BACKGROUND Injection of a clot into the internal carotid artery is an experimental model of ischemic stroke that is considered to closely mimic embolic stroke in humans. In this model, the common carotid artery typically remains temporarily occluded to permit time for stabilization of the clot in the middle cerebral artery. However, the associated lengthening of the anesthesia duration could affect arterial blood pressure and stroke outcome. NEW METHOD We refined the model by examining how increasing isoflurane anesthesia duration from 30 to 60 min after clot embolization affects mortality, infarct volume, edema, blood-brain barrier permeability, and the 8-h post-ischemic time course of blood pressure, which has not been reported previously in this model. RESULTS We found that arterial pressure increased after discontinuing anesthesia in both embolized groups and that the increase was greater than in the corresponding non-embolized sham-operated rats. At 24 h, the group with 60-min post-ischemia anesthesia exhibited greater brain water content and a greater ipsilateral-to-contralateral ratio of extravasated Evans blue dye. Mortality was greater in the 60-min group, but infarct volume among survivors was not different from that in the 30-min anesthesia group. COMPARISON WITH EXISTING METHODS This study refines the embolic stroke model by demonstrating the importance of minimizing the duration of anesthesia after embolization. CONCLUSIONS These data indicate that early discontinuation of isoflurane anesthesia after clot embolization permits an earlier hypertensive response that limits edema formation and mortality without significantly affecting infarct volume in survivors, thereby decreasing the required number of animals.
Collapse
Affiliation(s)
- Bryan T C Chuang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Anesthesiology, Saint Mary's Hospital Luodong, Taiwan
| | - Xiaoguang Liu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Alexander J Lundberg
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Tommy J K Toung
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - John A Ulatowski
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Raymond C Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
7
|
JOURNAL CLUB: Evaluation of Diffusion Kurtosis Imaging of Stroke Lesion With Hemodynamic and Metabolic MRI in a Rodent Model of Acute Stroke. AJR Am J Roentgenol 2018; 210:720-727. [PMID: 29470156 DOI: 10.2214/ajr.17.19134] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Diffusion kurtosis imaging (DKI) has emerged as a new acute stroke imaging approach, augmenting routine DWI. Although it has been shown that a diffusion lesion without kurtosis abnormality is more likely to recover after reperfusion, whereas a kurtosis lesion shows poor response, little is known about the underlying pathophysiologic profile of the kurtosis lesion versus the kurtosis lesion-diffusion lesion mismatch. MATERIALS AND METHODS We performed multiparametric MRI, including arterial spin labeling, pH-sensitive amide proton transfer, and DKI, in a rodent model of acute stroke caused by embolic middle cerebral artery occlusion. Diffusion and kurtosis lesions were semiautomatically segmented, and multiparametric MRI indexes were compared among the kurtosis lesion, diffusion lesion, kurtosis lesion-diffusion lesion mismatch, and the contralateral normal tissue area. RESULTS We confirmed a significant difference between diffusion lesion and kurtosis lesion volumes (mean [± SD] volume, 151 ± 65 vs 125 ± 47 mm3; p < 0.05). Although ischemic lesions have significantly reduced cerebral blood flow compared with contralateral normal tissue, we did not find a significant difference in cerebral blood flow between the kurtosis lesion and the kurtosis lesion-diffusion lesion mismatch (mean cerebral blood flow, 0.53 ± 0.10 vs 0.47 ± 0.14 mL/g of tissue per minute; p > 0.05). Of importance, the pH of the kurtosis lesion was significantly lower than that of the lesion mismatch (mean pH, 6.81 ± 0.08 vs 6.89 ± 0.09; p < 0.01). CONCLUSION The present study confirms that DKI provides an expedient approach for refining the heterogeneous DWI lesion that is associated with graded metabolic derangement, which is promising for improving the infarction core definition and ultimately helping to guide stroke treatment.
Collapse
|
8
|
Evolution of ischemic damage and behavioural deficit over 6 months after MCAo in the rat: Selecting the optimal outcomes and statistical power for multi-centre preclinical trials. PLoS One 2017; 12:e0171688. [PMID: 28182727 PMCID: PMC5300105 DOI: 10.1371/journal.pone.0171688] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 01/24/2017] [Indexed: 12/30/2022] Open
Abstract
Key disparities between the timing and methods of assessment in animal stroke studies and clinical trial may be part of the reason for the failure to translate promising findings. This study investigates the development of ischemic damage after thread occlusion MCAo in the rat, using histological and behavioural outcomes. Using the adhesive removal test we investigate the longevity of behavioural deficit after ischemic stroke in rats, and examine the practicality of using such measures as the primary outcome for future studies. Ischemic stroke was induced in 132 Spontaneously Hypertensive Rats which were assessed for behavioural and histological deficits at 1, 3, 7, 14, 21, 28 days, 12 and 24 weeks (n>11 per timepoint). The basic behavioural score confirmed induction of stroke, with deficits specific to stroke animals. Within 7 days, these deficits resolved in 50% of animals. The adhesive removal test revealed contralateral neglect for up to 6 months following stroke. Sample size calculations to facilitate the use of this test as the primary experimental outcome resulted in cohort sizes much larger than are the norm for experimental studies. Histological damage progressed from a necrotic infarct to a hypercellular area that cleared to leave a fluid filled cavity. Whilst absolute volume of damage changed over time, when corrected for changes in hemispheric volume, an equivalent area of damage was lost at all timepoints. Using behavioural measures at chronic timepoints presents significant challenges to the basic science community in terms of the large number of animals required and the practicalities associated with this. Multicentre preclinical randomised controlled trials as advocated by the MultiPART consortium may be the only practical way to deal with this issue.
Collapse
|
9
|
Henninger N, Fisher M. Extending the Time Window for Endovascular and Pharmacological Reperfusion. Transl Stroke Res 2016; 7:284-93. [DOI: 10.1007/s12975-015-0444-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 12/13/2015] [Accepted: 12/14/2015] [Indexed: 01/07/2023]
|
10
|
Jickling GC, Sharp FR. Improving the translation of animal ischemic stroke studies to humans. Metab Brain Dis 2015; 30:461-7. [PMID: 24526567 PMCID: PMC4186910 DOI: 10.1007/s11011-014-9499-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 01/28/2014] [Indexed: 12/18/2022]
Abstract
Despite testing more than 1,026 therapeutic strategies in models of ischemic stroke and 114 therapies in human ischemic stroke, only one agent tissue plasminogen activator has successfully been translated to clinical practice as a treatment for acute stroke. Though disappointing, this immense body of work has led to a rethinking of animal stroke models and how to better translate therapies to patients with ischemic stroke. Several recommendations have been made, including the STAIR recommendations and statements of RIGOR from the NIH/NINDS. In this commentary we discuss additional aspects that may be important to improve the translational success of ischemic stroke therapies. These include use of tissue plasminogen activator in animal studies; modeling ischemic stroke heterogeneity in terms of infarct size and cause of human stroke; addressing the confounding effect of anesthesia; use of comparable therapeutic dosage between humans and animals based on biological effect; modeling the human immune system; and developing outcome measures in animals comparable to those used in human stroke trials. With additional study and improved animal modeling of factors involved in human ischemic stroke, we are optimistic that new stroke therapies will be developed.
Collapse
Affiliation(s)
- Glen C Jickling
- Department of Neurology, MIND Institute Wet Labs Room 2415, University of California at Davis Medical Center, 2805 50th Street, Sacramento, CA, 95817, USA,
| | | |
Collapse
|
11
|
Jin Y, Dong L, Wu C, Qin J, Li S, Wang C, Shao X, Huang D. Buyang Huanwu Decoction fraction protects against cerebral ischemia/reperfusion injury by attenuating the inflammatory response and cellular apoptosis. Neural Regen Res 2014; 8:197-207. [PMID: 25206589 PMCID: PMC4107522 DOI: 10.3969/j.issn.1673-5374.2013.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 11/20/2012] [Indexed: 01/08/2023] Open
Abstract
Buyang Huanwu Decoction fraction extracted from Buyang Huanwu Decoction contains saponins of Astragalus, total paeony glycoside and safflower flavones. The aim of this study was to demonstrate the neuroprotective effect and mechanism of Buyang Huanwu Decoction fraction on ischemic injury both in vivo and in vitro. In vivo experiments showed that 50-200 mg/kg Buyang Huanwu Decoction fraction reduced infarct volume and pathological injury in ischemia/reperfusion rats, markedly inhibited expression of nuclear factor-κB and tumor necrosis factor-α and promoted nestin protein expression in brain tissue. Buyang Huanwu Decoction fraction (200 mg/kg) exhibited significant effects, which were similar to those of 100 mg/kg Ginkgo biloba extract. In vitro experimental results demonstrated that 10-100 mg/L Buyang Huanwu Decoction fraction significantly improved cell viability, decreased the release of lactate dehydrogenase and malondialdehyde levels, and inhibited the rate of apoptosis in HT22 cells following oxygen-glucose deprivation. Buyang Huanwu Decoction fraction (100 mg/L) exhibited significant effects, which were similar to those of 100 mg/L Ginkgo biloba extract. These findings suggest that Buyang Huanwu Decoction fraction may represent a novel, protective strategy against cerebral ischemia/reperfusion injury in rats and oxygen-glucose deprivation-induced damage in HT22 cells in vitro by attenuating the inflammatory response and cellular apoptosis.
Collapse
Affiliation(s)
- Yulian Jin
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education; Key Laboratory of Chinese Medicine Research and Development, State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, Anhui Province, China ; Anhui Provincial Children's Hospital, Hefei 230051, Anhui Province, China
| | - Liuyi Dong
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education; Key Laboratory of Chinese Medicine Research and Development, State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, Anhui Province, China
| | - Changqing Wu
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education; Key Laboratory of Chinese Medicine Research and Development, State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, Anhui Province, China
| | - Jiang Qin
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education; Key Laboratory of Chinese Medicine Research and Development, State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, Anhui Province, China
| | - Sheng Li
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education; Key Laboratory of Chinese Medicine Research and Development, State Administration of Traditional Chinese Medicine, Anhui Medical University, Hefei 230032, Anhui Province, China
| | - Chunyan Wang
- Anhui Institute of Materia Medica, Hefei 230022, Anhui Province, China
| | - Xu Shao
- Hefei Qi-xing Medicine and Technology Co., Ltd., Hefei 230088, Anhui Province, China
| | - Dake Huang
- Synthetic Laboratory of Basic Medicine College, Anhui Medical University, Hefei 230032, Anhui Province, China
| |
Collapse
|
12
|
Clot injection technique affects thrombolytic efficacy in a rat embolic stroke model: implications for translaboratory collaborations. J Cereb Blood Flow Metab 2014; 34:677-82. [PMID: 24424380 PMCID: PMC3982093 DOI: 10.1038/jcbfm.2014.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/20/2013] [Accepted: 12/23/2013] [Indexed: 01/08/2023]
Abstract
Current recommendations encourage the use of embolic stroke (ES) models and replication of results across laboratories in preclinical research. Since such endeavors employ different surgeons, we sought to ascertain the impact of injection technique on outcome and response to thrombolysis in an ES model. Embolic stroke was induced in Male Wistar Kyoto rats (n=166) by a fast or a slow clot injection (CI) technique. Saline or recombinant tissue plasminogen activator (rtPA) was given at 1 hour after stroke. Flow rate curves were assessed in 24 animals. Cerebral perfusion was assessed using laser Doppler flowmetry. Edema corrected infarct volume, hemispheric swelling, hemorrhagic transformation, and neurologic outcome were assessed at 24 hours after stroke. Clot burden was estimated in a subset of animals (n=40). Slow CI resulted in significantly smaller infarct volumes (P=0.024) and better neurologic outcomes (P=0.01) compared with fast CI at 24 hours. Unexpectedly, rtPA treatment attenuated infarct size in fast (P<0.001) but not in slow CI experiments (P=0.382), possibly related to reperfusion injury as indicated by greater hemorrhagic transformation (P<0.001) and hemispheric swelling (P<0.05). Outcome and response to thrombolysis after ES are operator dependent, which needs to be considered when comparing results obtained from different laboratories.
Collapse
|
13
|
Present status and future challenges of electroencephalography- and magnetic resonance imaging-based monitoring in preclinical models of focal cerebral ischemia. Brain Res Bull 2014; 102:22-36. [PMID: 24462642 DOI: 10.1016/j.brainresbull.2014.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 01/07/2014] [Accepted: 01/14/2014] [Indexed: 12/16/2022]
Abstract
Animal models are useful tools for better understanding the mechanisms underlying neurological deterioration after an ischemic insult as well as subsequent evolution of changes and recovery of functions. In response to the updated requirements for preclinical investigations of stroke to include relevant functional measurement techniques and biomarker endpoints, we here review the state of knowledge on application of some translational electrophysiological and neuroimaging methods, and in particular, electroencephalography monitoring and magnetic resonance imaging in rodent models of ischemic stroke. This may lead to improvement of diagnostic methods and identification of new therapeutic targets, which would considerably advance the translational value of preclinical stroke research.
Collapse
|
14
|
Embolic middle cerebral artery occlusion model using thrombin and fibrinogen composed clots in rat. J Neurosci Methods 2012; 211:296-304. [PMID: 22985597 DOI: 10.1016/j.jneumeth.2012.09.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 08/27/2012] [Accepted: 09/05/2012] [Indexed: 11/23/2022]
Abstract
Ischemic stroke accounts for over 80% in total human stroke which mostly affect middle cerebral artery (MCA) territory. Embolic stroke models induced by injection of homologous clots into the internal carotid artery and MCA closely mimic human stroke and have been commonly used in stroke research. Studies indicate that the size and composition of clots are critical for the reproducibility of the stroke model. In the present study, we modified the homologous clots formation by addition of thrombin and fibrinogen which produced even distribution of fibrin with tight cross linkage of red blood cells. We optimized the embolic MCA occlusion model in rats using different size of the mixed clots. A precise lodgment of the clots at the MCA bifurcation and highly reproducible ischemic lesion in the MCA territory were demonstrated in the embolic MCA occlusion model induced by injection of 10 pieces of 1-mm long mixed clots made in PE-60 catheter. We further tested the effect of recombinant tissue plasminogen activator (rtPA) in this embolic MCA occlusion model. rtPA induced thrombolysis, improved neurological outcome, and significantly reduced ischemic lesion volume when administered at 1h after embolism as compared with control. In summary, we have established a reproducible embolic MCA occlusion model using clots made of homologous blood, thrombin and fibrinogen. The mixed clots enable precise lodgment at the MCA bifurcation which is responsive to thrombolytic therapy of rtPA.
Collapse
|
15
|
Fisher M, Bråtane BT. Imaging of experimental stroke models. Transl Stroke Res 2011; 3:16-21. [PMID: 24323752 DOI: 10.1007/s12975-011-0113-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 10/04/2011] [Accepted: 10/06/2011] [Indexed: 11/30/2022]
Abstract
The ischemic penumbra is the target of acute stroke therapy. It can be approximated on diffusion/perfusion MRI as the ischemic region with abnormal perfusion and normal diffusion imaging. Using arterial spin labeling perfusion MRI and diffusion MRI, our group has studied the evolution of the diffusion/perfusion mismatch in rat stroke models. Additionally, we have evaluated the effects of high-flow oxygen on the natural history of penumbral evolution, demonstrating that high-flow oxygen "freezes" the evolution of the mismatch and allows for later beneficial use of intravenous tissue plasminogen activator (tPA). Two neuroprotective drugs, Granulocyte colony stimulating factor and a PSD95 inhibitor both impeded the evolution of the mismatch into infarcted tissue in vivo and by histological analysis. Employing a novel technique of clot imaging, our group was able to demonstrate that the combination of tPA plus Annexin-2 was superior to tPA alone in dissolving an embolus and also in reducing the extent of hypoperfused brain tissue of perfusion imaging. The use of these advanced MRI techniques in animal experiments will help to advance clinical imaging of the ischemic penumbra and hopefully contribute to the extension of the therapeutic time window in stroke patients.
Collapse
Affiliation(s)
- Marc Fisher
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA,
| | | |
Collapse
|
16
|
Walvick RP, Bråtane BT, Henninger N, Sicard KM, Bouley J, Yu Z, Lo E, Wang X, Fisher M. Visualization of clot lysis in a rat embolic stroke model: application to comparative lytic efficacy. Stroke 2011; 42:1110-5. [PMID: 21372305 DOI: 10.1161/strokeaha.110.602102] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of this study was to develop a novel MRI method for imaging clot lysis in a rat embolic stroke model and to compare tissue plasminogen activator (tPA)-based clot lysis with and without recombinant Annexin-2 (rA2). METHODS In experiment 1 we used in vitro optimization of clot visualization using multiple MRI contrast agents in concentrations ranging from 5 to 50 μL in 250 μL blood. In experiment 2, we used in vivo characterization of the time course of clot lysis using the clot developed in the previous experiment. Diffusion, perfusion, angiography, and T1-weighted MRI for clot imaging were conducted before and during treatment with vehicle (n=6), tPA (n=8), or rA2 plus tPA (n=8) at multiple time points. Brains were removed for ex vivo clot localization. RESULTS Clots created with 25 μL Magnevist were the most stable and provided the highest contrast-to-noise ratio. In the vehicle group, clot length as assessed by T1-weighted imaging correlated with histology (r=0.93). Clot length and cerebral blood flow-derived ischemic lesion volume were significantly smaller than vehicle at 15 minutes after treatment initiation in the rA2 plus tPA group, whereas in the tPA group no significant reduction from vehicle was observed until 30 minutes after treatment initiation. The rA2 plus tPA group had a significantly shorter clot length than the tPA group at 60 and 90 minutes after treatment initiation and significantly smaller cerebral blood flow deficit than the tPA group at 90 minutes after treatment initiation. CONCLUSIONS We introduce a novel MRI-based clot imaging method for in vivo monitoring of clot lysis. Lytic efficacy of tPA was enhanced by rA2.
Collapse
Affiliation(s)
- Ronn P Walvick
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Lee TH, Liu HL, Yang ST, Yang JT, Yeh MY, Lin JR. Effects of aging and hypertension on cerebral ischemic susceptibility: Evidenced by MR diffusion–perfusion study in rat. Exp Neurol 2011; 227:314-21. [DOI: 10.1016/j.expneurol.2010.12.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 11/16/2010] [Accepted: 12/03/2010] [Indexed: 11/25/2022]
|
18
|
Zhou X, Sun Y, Mazzanti M, Henninger N, Mansour J, Fisher M, Albert M. MRI of stroke using hyperpolarized 129Xe. NMR IN BIOMEDICINE 2011; 24:170-175. [PMID: 20821723 DOI: 10.1002/nbm.1568] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 04/20/2010] [Accepted: 04/21/2010] [Indexed: 05/26/2023]
Abstract
Because there is no background signal from xenon in biological tissue, and because inhaled xenon is delivered to the brain by blood flow, we would expect a perfusion deficit, such as is seen in stroke, to reduce the xenon concentration in the region of the deficit. Thermal polarization yields negligible xenon signal relative to hyperpolarized xenon; therefore, hyperpolarized xenon can be used as a tracer of cerebral blood flow. Using a rat permanent right middle cerebral artery occlusion model, we demonstrated that hyperpolarized (129)Xe MRI is able to detect, in vivo, the hypoperfused area of focal cerebral ischemia, that is the ischemic core area of stroke. To the best of our knowledge, this is the first time that hyperpolarized (129)Xe MRI has been used to explore normal and abnormal cerebral perfusion. Our study shows a novel application of hyperpolarized (129)Xe MRI for imaging stroke, and further demonstrates its capacity to serve as a complementary tool to proton MRI for the study of the pathophysiology during brain hypoperfusion.
Collapse
Affiliation(s)
- Xin Zhou
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, China.
| | | | | | | | | | | | | |
Collapse
|
19
|
Calloni RL, Winkler BC, Ricci G, Poletto MG, Homero WM, Serafini EP, Corleta OC. Transient middle cerebral artery occlusion in rats as an experimental model of brain ischemia. Acta Cir Bras 2010; 25:428-33. [DOI: 10.1590/s0102-86502010000500008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 05/18/2010] [Indexed: 11/21/2022] Open
Abstract
PURPOSE: To assess a rat model of cerebral ischemia induced by occlusion of the middle cerebral artery and its effect on the area of cerebral infarction. METHODS: Brain ischemia was induced in 52 male Wistar rats by introduction of a 3-0 nylon suture into the middle cerebral artery for either 90 (n=28) or 120 (n=24) minutes. Ischemic injury volume was determined by TTC staining, digital photography and analysis with the Image J software. Statistical analysis employed Student’s t test and the Mann-Whitney U test. RESULTS: The groups were similar in terms of weight (p=0.59). The length of thread inserted was 14.7 mm in the 90 min group and 20.2 mm in the 120 min group (p=0.37). Ischemic injury was detected in 11 animals (39%) after 90 min and 11 (45%) after 120 min (p=0.77). In animals exhibiting injury, filament length was 16.1±11 mm (90 min) vs. 21.9±7.4 mm (120 min) (p=0.15). The mean infarction zone volume was greater after 120 (259.2 mm³) than after 90 min (162.9 mm³) (p=0.04). The neurological deficit score for the 90 and 120 min groups was 2.0 and 2.4, respectively (p=0.84). CONCLUSION: The experimental model induced significant ischemic cerebral injury in both groups.
Collapse
|
20
|
Use of magnetic resonance imaging to predict outcome after stroke: a review of experimental and clinical evidence. J Cereb Blood Flow Metab 2010; 30:703-17. [PMID: 20087362 PMCID: PMC2949172 DOI: 10.1038/jcbfm.2010.5] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Despite promising results in preclinical stroke research, translation of experimental data into clinical therapy has been difficult. One reason is the heterogeneity of the disease with outcomes ranging from complete recovery to continued decline. A successful treatment in one situation may be ineffective, or even harmful, in another. To overcome this, treatment must be tailored according to the individual based on identification of the risk of damage and estimation of potential recovery. Neuroimaging, particularly magnetic resonance imaging (MRI), could be the tool for a rapid comprehensive assessment in acute stroke with the potential to guide treatment decisions for a better clinical outcome. This review describes current MRI techniques used to characterize stroke in a preclinical research setting, as well as in the clinic. Furthermore, we will discuss current developments and the future potential of neuroimaging for stroke outcome prediction.
Collapse
|
21
|
Characterization of gadolinium-based dynamic susceptibility contrast perfusion measurements in permanent and transient MCAO models with volumetric based validation by CASL. J Cereb Blood Flow Metab 2010; 30:336-42. [PMID: 19826434 PMCID: PMC2949116 DOI: 10.1038/jcbfm.2009.218] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Perfusion imaging is crucial in imaging of ischemic stroke to determine 'tissue at risk' for infarction. In this study we compared the volumetric quantification of the perfusion deficit in two rat middle-cerebral-artery occlusion (MCAO) models using two gadolinium-based contrast agents (P1152 (Guerbet) and Magnevist (Bayer-Schering, Pittsburgh, PA, USA)) as compared with our well established continuous arterial spin labeling (CASL) perfusion imaging technique. Animals underwent either permanent MCAO or transient MCAO with 80-min reperfusion. Imaging was performed at four different time points after MCAO. A region-of-interest (ROI) analysis of the subregions of the ischemic zone (core, penumbra, transient reversal (TR), and sustained reversal (SR)) using P1152 showed significant reduction in blood flow in the core and TR subregions relative to the penumbral and SR subregions while occluded. After reperfusion, a significant increase in blood flow was recorded at all time points after reperfusion in all regions except TR. From the ROI analysis the threshold for the penumbra was determined to be -62+/-11% and this value was subsequently used for quantification of the volumetric deficit. The ischemic volume as defined by dynamic susceptibility contrast (DSC), was only statistically different from the CASL-derived ischemic volume when using Magnevist at post-reperfusion time points.
Collapse
|
22
|
Notch-Induced Rat and Human Bone Marrow Stromal Cell Grafts Reduce Ischemic Cell Loss and Ameliorate Behavioral Deficits in Chronic Stroke Animals. Stem Cells Dev 2009; 18:1501-14. [DOI: 10.1089/scd.2009.0011] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
23
|
Long-term functional and neurological outcome after simultaneous treatment with tissue-plasminogen activator and hyperbaric oxygen in early phase of embolic stroke in rats. Brain Res 2009; 1303:161-8. [DOI: 10.1016/j.brainres.2009.09.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 09/05/2009] [Accepted: 09/11/2009] [Indexed: 11/22/2022]
|
24
|
Bra°tane BT, Bastan B, Fisher M, Bouley J, Henninger N. Ischemic lesion volume determination on diffusion weighted images vs. apparent diffusion coefficient maps. Brain Res 2009; 1279:182-8. [DOI: 10.1016/j.brainres.2009.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 05/01/2009] [Accepted: 05/02/2009] [Indexed: 10/20/2022]
|
25
|
Henninger N, Bouley J, Bråtane BT, Bastan B, Shea M, Fisher M. Laser Doppler flowmetry predicts occlusion but not tPA-mediated reperfusion success after rat embolic stroke. Exp Neurol 2009; 215:290-7. [DOI: 10.1016/j.expneurol.2008.10.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 10/14/2008] [Accepted: 10/23/2008] [Indexed: 10/21/2022]
|
26
|
Abstract
In a rat embolic stroke (eMCAO) model, the effects of 100% normobaric hyperoxia (NBO) with delayed recombinant tissue plasminogen activator (tPA) administration on ischemic lesion size and safety were assessed by diffusion- and perfusion (PWI)-weighted magnetic resonance imaging. NBO or room air (Air) by a face mask was started at 30 mins posteMCAO and continued for 3.5 h. Tissue plasminogen activator or saline was started at 3 h posteMCAO. Types and location of hemorrhagic transformation were assessed at 24 h and a spectrophotometric hemoglobin assay quantified hemorrhage volume at 10 h. In NBO-treated animals the apparent diffusion coefficient/PWI mismatch persisted during NBO treatment. Relative to Air groups, NBO treatment significantly reduced 24 h infarct volumes by approximately 30% and approximately 15% with or without delayed tPA, respectively (P<0.05). There were significantly more hemorrhagic infarction type 2 hemorrhages in Air/tPA versus Air/saline animals (P<0.05). Compared with Air/tPA, the combination of NBO with tPA did not increase hemorrhage volume at 10 h (4.0+/-2.4 versus 6.6+/-2.6 microL, P=0.065) or occurrence of confluent petechial hemorrhages at 24 h (P>0.05), respectively. Our results suggest that early NBO treatment in combination with tPA at a later time point may represent a safe and effective strategy for acute stroke treatment.
Collapse
|
27
|
Abstract
Oxygen is frequently administered to patients with suspected stroke. However, the role of oxygen therapy in ischemic stroke remains controversial in light of the failure of three clinical trials of hyperbaric oxygen therapy to show efficacy, and the fear of exacerbating oxygen free radical injury. The previous trials had several shortcomings, perhaps because they were designed on basis of anecdotal case reports and little preclinical data. Most animal studies concerning oxygen therapy in stroke have been conducted over the last 6 years. Emerging data suggests that hyperbaric and even normobaric oxygen therapy can be effective if used appropriately, and raises the tantalizing possibility that hyperoxia can be used to extend the narrow therapeutic time window for stroke thrombolysis. This article reviews the history, rationale, mechanisms of action and adverse effects of hyperoxia, the key results of previous hyperoxia studies, and the potential role of oxygen therapy in contemporary stroke treatment.
Collapse
Affiliation(s)
- Aneesh B Singhal
- Massachusetts General Hospital, Stroke Research Center, 175 Cambridge Street, Suite 300, Boston, MA 02114, USA.
| |
Collapse
|
28
|
Kim HJ, Yun SC, Cho KH, Cho AH, Kwon SU, Kim JS, Kang DW. Differential patterns of evolution in acute middle cerebral artery infarction with perfusion-diffusion mismatch: atherosclerotic vs. cardioembolic occlusion. J Neurol Sci 2008; 273:93-8. [PMID: 18692854 DOI: 10.1016/j.jns.2008.06.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Accepted: 06/24/2008] [Indexed: 11/26/2022]
Abstract
BACKGROUND An acute perfusion-diffusion mismatch is known to be the strongest predictor of infarct growth. However, the differential patterns of clinical and radiological evolution according to stroke mechanism are unknown. METHODS The study retrospectively reviewed consecutive patients who had 1) acute middle cerebral artery (MCA) territory infarction, 2) diffusion- and perfusion-weighted imaging (DWI and PWI) and MR angiography within 24 h of onset, and follow-up DWI 5 days later, 3) stenosis (> or =50%) or occlusion of MCA on baseline imaging, 4) a baseline PWI-DWI mismatch >20%, and 5) either atherosclerotic MCA disease (MCAD) or cardioembolism (CE). National Institutes of Health Stroke Scale (NIHSS) scores and infarct volume at baseline and 5 days were obtained. RESULTS Of 90 patients, 52 had MCAD and 38 had CE. At baseline, CE group had more severe stroke (median NIHSS, 9 vs. 5; p=0.001) and larger infarct volume (median 8.32 cc vs. 3.0 cc; p=0.034) than MCAD group. During the 1-week period, CE group had larger infarct volume growth (median 12.85 cc vs. 3.02 cc; p=0.004) than MCAD group, although clinical improvement based on NIHSS (baseline minus 5-day) tended to be higher for CE than MCAD group (median 3 vs. 1; p=0.08). The correlation between infarct volume and NIHSS score was stronger in CE (r=0.841) compared to MCAD (r=0.582) group at 5-day. CONCLUSIONS Substantial differences in the clinico-radiological evolution of acute ischemic stroke exist according to stroke mechanism. These data emphasize the importance of the stroke mechanism in the design of MRI-based acute stroke trials.
Collapse
Affiliation(s)
- Hye-Jin Kim
- Department of Preventive Medicine, Asan Medical Center, University of Ulsan College of Medicine, South Korea
| | | | | | | | | | | | | |
Collapse
|
29
|
Sun PZ, Murata Y, Lu J, Wang X, Lo EH, Sorensen AG. Relaxation-compensated fast multislice amide proton transfer (APT) imaging of acute ischemic stroke. Magn Reson Med 2008; 59:1175-82. [PMID: 18429031 DOI: 10.1002/mrm.21591] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Amide proton transfer (APT) imaging is a variant form of chemical exchange saturation transfer (CEST) imaging that is based on the magnetization exchange between bulk water and labile endogenous amide protons. Given that chemical exchange is pH-dependent, APT imaging has been shown capable of imaging ischemic tissue acidosis, and as such, may serve as a surrogate metabolic imaging marker complementary to perfusion and diffusion MRI. In order for APT imaging to properly diagnose heterogeneous pathologies such as stroke and cancer, fast volumetric APT imaging has to be developed. In this study the evolution of CEST contrast after RF irradiation was solved showing that although the CEST steady state is reached by the apparent longitudinal relaxation rate, the decreases of CEST contrast after irradiation is governed by the intrinsic relaxation constant. A volumetric APT imaging sequence is proposed that acquires multislice images immediately after a single long continuous wave (CW) RF irradiation, wherein the relaxation-induced loss of CEST contrast is compensated for during postprocessing. The proposed technique was verified by numerical simulation, a tissue-like dual-pH phantom, and demonstrated on an embolic stroke animal model. In summary, our study has established a fast volumetric pH-weighted APT imaging technique, allowing further investigation to fully evaluate its diagnostic power.
Collapse
Affiliation(s)
- Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Department of Radiology and Harvard Medical School, 149 13th Street, Charlestown, MA 02129, USA.
| | | | | | | | | | | |
Collapse
|
30
|
Legos JJ, Lenhard SC, Haimbach RE, Schaeffer TR, Bentley RG, McVey MJ, Chandra S, Irving EA, Andrew A. Parsons, Barone FC. SB 234551 selective ETA receptor antagonism: Perfusion/Diffusion MRI used to define treatable stroke model, time to treatment and mechanism of protection. Exp Neurol 2008; 212:53-62. [DOI: 10.1016/j.expneurol.2008.03.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2007] [Revised: 02/29/2008] [Accepted: 03/03/2008] [Indexed: 10/22/2022]
|
31
|
Henninger N, Sicard KM, Fisher M. Spectacular shrinking deficit: insights from multimodal magnetic resonance imaging after embolic middle cerebral artery occlusion in Sprague-Dawley rats. J Cereb Blood Flow Metab 2007; 27:1756-63. [PMID: 17377514 DOI: 10.1038/sj.jcbfm.9600477] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Almost no data is available on the serial changes in the brain after spectacular shrinking deficit (SSD) that may help understand this relatively rare clinical phenomenon. Quantitative diffusion-(DWI), perfusion-(PWI), T(1)-(T1WI), T(2)-weighted (T2WI), and functional magnetic resonance imaging (fMRI) were performed before, during, and up to 7 days after embolic middle cerebral artery occlusion (eMCAO) in male Sprague-Dawley rats (n=9). Region of interest (ROI) analysis was used to evaluate structural and functional MR signal changes within three ROIs defined by the apparent diffusion coefficient (ADC), cerebral blood flow (CBF) signatures, and final tissue viability. DWI, PWI, and T2WI lesion volumes were calculated using previously established viability thresholds and final infarct volumes ascertained with 2,3,5-triphenyltetrazolium chloride (TTC) staining. Serial MRI demonstrated spontaneous reperfusion of initially hypoperfused MCA regions accompanied by substantial reduction of initial ADC and CBF lesions and gradual recovery of neurological outcome. Recovery rates of CBF/ADC abnormalities differed among ROIs. Functional magnetic resonance imaging showed persistent tissue dysfunction after the recovery of the CBF/ADC lesions. This study may facilitate our understanding of the pathophysiological mechanisms by which early, spontaneous reperfusion affects tissue fate and neurological function.
Collapse
Affiliation(s)
- Nils Henninger
- Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
| | | | | |
Collapse
|
32
|
Henninger N, Bouley J, Nelligan JM, Sicard KM, Fisher M. Normobaric hyperoxia delays perfusion/diffusion mismatch evolution, reduces infarct volume, and differentially affects neuronal cell death pathways after suture middle cerebral artery occlusion in rats. J Cereb Blood Flow Metab 2007; 27:1632-42. [PMID: 17311078 DOI: 10.1038/sj.jcbfm.9600463] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Normobaric hyperoxia (NBO) has been shown to extend the reperfusion window after focal cerebral ischemia. Employing diffusion (DWI)- and perfusion (PWI)-weighted magnetic resonance imaging (MRI), the effect of NBO (100% started at 30 mins after middle cerebral artery occlusion (MCAO)) on the spatiotemporal evolution of ischemia during and after permanent (pMCAO) and transient suture middle cerebral artery occlusion (tMCAO) was investigated (experiment 3). In two additional experiments, time window (experiment 1) and cell death pathways (experiment 2) were investigated in the pMCAO model. In experiment 1, NBO treatment reduced infarct volume at 24 h after pMCAO by 10% when administered for 3 h (P>0.05) and by 44% when administered for 6 h (P<0.05). In experiment 2, NBO acutely (390 mins, P<0.05) reduced in situ end labeling (ISEL) positivity in the ipsilesional penumbra but increased contralesional necrotic as well as caspase-3-mediated apoptotic cell death. In experiment 3, CBF characteristics and CBF-derived lesion volumes did not differ between treated and untreated animals, whereas the apparent diffusion coefficient (ADC)-derived lesion volume essentially stopped progressing during NBO treatment, resulting in a persistent PWI/DWI mismatch that could be salvaged by delayed (3 h) reperfusion. In conclusion, NBO (1) acutely preserved the perfusion/diffusion mismatch without altering CBF, (2) significantly extended the time window for reperfusion, (3) induced lasting neuroprotection in permanent ischemia, and (4) although capable of reducing cell death in hypoperfused tissue it also induced cell death in otherwise unaffected areas. Our data suggest that NBO may represent a promising strategy for acute stroke treatment.
Collapse
Affiliation(s)
- Nils Henninger
- Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
| | | | | | | | | |
Collapse
|
33
|
Bouley J, Fisher M, Henninger N. Comparison between coated vs. uncoated suture middle cerebral artery occlusion in the rat as assessed by perfusion/diffusion weighted imaging. Neurosci Lett 2006; 412:185-90. [PMID: 17123725 DOI: 10.1016/j.neulet.2006.11.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2006] [Revised: 11/01/2006] [Accepted: 11/02/2006] [Indexed: 10/23/2022]
Abstract
Differences among models in the temporal evolution of ischemia after middle cerebral artery occlusion (MCAO) in rats may considerably influence the results of experimental treatment studies. Using diffusion and perfusion imaging, we compared the spatiotemporal evolution of ischemia in Sprague-Dawley rats after permanent MCAO (pMCAO) with different types of sutures. Male Sprague-Dawley rats were randomly assigned to pMCAO produced with either 4-0 silicone coated (n=8), or 3-0 uncoated monofilaments (n=8). Serial determination of quantitative cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) maps were performed up to 3 h after pMCAO. Lesion volumes were calculated by using previously validated thresholds and correlated with infarct volume corrected for edema defined by 2,3,5-triphenyltetrazolium chloride (TTC) staining at 24 h after MCAO. The ADC/CBF-defined mismatch volume in the 4-0 coated suture model was present significantly longer (up to 120 min) compared to the uncoated 3-0 suture model (30 min). The TTC-derived infarct volume was significantly larger in the coated model (290.3+/-32.8 mm(3)) relative to the uncoated model (252.3+/-34.6 mm(3)). This study demonstrates that the type of suture may significantly influence the spatiotemporal evolution of the ADC/CBF-mismatch as well as the final infarct volume. These inter-model variations must be taken into account when assessing new therapeutic approaches on ischemic lesion evolution in the rat MCAO model.
Collapse
Affiliation(s)
- James Bouley
- Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
| | | | | |
Collapse
|