Granulocyte-Colony Stimulating Factor (G-CSF) Improves Motor Recovery in the Rat Impactor Model for Spinal Cord Injury

Granulocyte-colony stimulating factor (G-CSF) improves outcome after experimental SCI by counteracting apoptosis, and enhancing connectivity in the injured spinal cord. Previously we have employed the mouse hemisection SCI model and studied motor function after subcutaneous or transgenic delivery of the protein. To further broaden confidence in animal efficacy data we sought to determine efficacy in a different model and a different species. Here we investigated the effects of G-CSF in Wistar rats using the New York University Impactor. In this model, corroborating our previous data, rats treated subcutaneously with G-CSF over 2 weeks show significant improvement of motor function

Differential Effects of HIF-1 Inhibition by YC-1 on the Overall Outcome and Blood-Brain Barrier Damage in a Rat Model of Ischemic Stroke

Hypoxia-inducible factor 1 (HIF-1) is a master regulator of cellular adaptation to hypoxia and has been suggested as a potent therapeutic target in cerebral ischemia. Here we show in an ischemic stroke model of rats that inhibiting HIF-1 and its downstream genes by 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) significantly increases mortality and enlarges infarct volume evaluated by MRI and histological staining. Interestingly, the HIF-1 inhibition remarkably ameliorates ischemia-induced blood-brain barrier (BBB) disruption determined by Evans blue leakage although it does not affect brain edema. The result demonstrates that HIF-1 inhibition has differential effects on ischemic outcomes and BBB permeability. It indicates that HIF-1 may have different functions in different brain cells. Further analyses show that ischemia upregulates HIF-1 and its downstream genes erythropoietin (EPO), vascular endothelial growth factor (VEGF), and glucose transporter (Glut) in neurons and brain endothelial cells and that YC-1 inhibits their expression. We postulate that HIF-1-induced VEGF increases BBB permeability while certain other proteins coded by HIF-1's downstream genes such as epo and glut provide neuroprotection in an ischemic brain. The results indicate that YC-1 lacks the potential as a cerebral ischemic treatment although it confers certain protection to the cerebral vascular system

A systematic review of clinical trials of pharmacological interventions for acute ischaemic stroke (1955-2008) that were completed, but not published in full

<p>Abstract</p> <p>Background</p> <p>We assessed the prevalence, and potential impact of, trials of pharmacological agents for acute stroke that were completed but not published in full. Failure to publish trial data is to be deprecated as it sets aside the altruism of participants' consent to be exposed to the risks of experimental interventions, potentially biases the assessment of the effects of therapies, and may lead to premature discontinuation of research into promising treatments.</p> <p>Methods</p> <p>We searched the Cochrane Stroke Group's Specialised Register of Trials in June 2008 for completed trials of pharmacological interventions for acute ischaemic stroke, and searched MEDLINE and EMBASE (January 2007 - March 2009) for references to recent full publications. We assessed trial completion status from trial reports, online trials registers and correspondence with experts.</p> <p>Results</p> <p>We identified 940 trials. Of these, 125 (19.6%, 95% confidence interval 16.5-22.6) were completed but not published in full by the point prevalence date. They included 16,058 participants (16 trials had over 300 participants each) and tested 89 different interventions. Twenty-two trials with a total of 4,251 participants reported the number of deaths. In these trials, 636/4251 (15.0%) died.</p> <p>Conclusions</p> <p>Our data suggest that, at the point prevalence date, a substantial body of evidence that was of relevance both to clinical practice in acute stroke and future research in the field was not published in full. Over 16,000 patients had given informed consent and were exposed to the risks of therapy. Responsibility for non-publication lies with investigators, but pharmaceutical companies, research ethics committees, journals and governments can all encourage the timely publication of trial data.</p

Multilineage Potential of Stable Human Mesenchymal Stem Cell Line Derived from Fetal Marrow

Human bone marrow contains two major cell types, hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). MSCs possess self-renewal capacity and pluripotency defined by their ability to differentiate into osteoblasts, chondrocytes, adipocytes and muscle cells. MSCs are also known to differentiate into neurons and glial cells in vitro, and in vivo following transplantation into the brain of animal models of neurological disorders including ischemia and intracerebral hemorrhage (ICH) stroke. In order to obtain sufficient number and homogeneous population of human MSCs, we have clonally isolated permanent and stable human MSC lines by transfecting primary cell cultures of fetal human bone marrow MSCs with a retroviral vector encoding v-myc gene. One of the cell lines, HM3.B10 (B10), was found to differentiate into neural cell types including neural stem cells, neurons, astrocytes and oligodendrocytes in vitro as shown by expression of genetic markers for neural stem cells (nestin and Musashi1), neurons (neurofilament protein, synapsin and MAP2), astrocytes (glial fibrillary acidic protein, GFAP) and oligodendrocytes (myelin basic protein, MBP) as determined by RT-PCR assay. In addition, B10 cells were found to differentiate into neural cell types as shown by immunocytochical demonstration of nestin (for neural stem cells), neurofilament protein and β-tubulin III (neurons) GFAP (astrocytes), and galactocerebroside (oligodendrocytes). Following brain transplantation in mouse ICH stroke model, B10 human MSCs integrate into host brain, survive, differentiate into neurons and astrocytes and induce behavioral improvement in the ICH animals. B10 human MSC cell line is not only a useful tool for the studies of organogenesis and specifically for the neurogenesis, but also provides a valuable source of cells for cell therapy studies in animal models of stroke and other neurological disorders

Hemorrhagic transformation of ischemic brain tissue asymptomatic or symptomatic?

Background and Purpose - The term symptomatic hemorrhage secondary to ischemic stroke implies a clear causal relationship between clinical deterioration and hemorrhagic transformation (HT) regardless of the type of HT. The aim of this study was to assess which type of HT independently affects clinical outcome. Methods - We used the data set of the European Cooperative Acute Stroke Study (ECASS) II for a post hoc analysis. All patients had a control CT scan after 24 to 96 hours or earlier in case of rapid and severe clinical deterioration. HT was categorized according to radiological criteria: hemorrhagic infarction type 1 and type 2 and parenchymal hematoma type 1 and type 2. The clinical course was prospectively documented with the National Institutes of Health Stroke Scale and the modified Rankin Scale. The independent risk of each type of HT was calculated for clinical deterioration at 24 hours and disability and death at 3 months after stroke onset and adjusted for possible confounding factors such as age, severity of stroke syndrome at baseline, and extent of the ischemic lesion on the initial CT. Results - Compared with absence of HT, only parenchymal hematoma type 2 was associated with an increased risk for deterioration at 24 hours after stroke onset (adjusted odds ratio, 18; 95% CI, 6 to 56) and for death at 3 months (adjusted odds ratio, 11; 95% CI, 3.7 to 36). All other types of HT did not independently increase the risk of late deterioration. Conclusions - Only parenchymal hematoma type 2 independently causes clinical deterioration and impairs prognosis. It has a distinct radiological feature: it is a dense homogeneous hematoma >30% of the ischemic lesion volume with significant space-occupying effect