TY - JOUR A1 - Minnerup, Jens A1 - Sutherland, Brad A. A1 - Buchan, Alastair M. A1 - Kleinschnitz, Christoph T1 - Neuroprotection for Stroke: Current Status and Future Perspectives JF - International Journal of Molecular Science N2 - Neuroprotection aims to prevent salvageable neurons from dying. Despite showing efficacy in experimental stroke studies, the concept of neuroprotection has failed in clinical trials. Reasons for the translational difficulties include a lack of methodological agreement between preclinical and clinical studies and the heterogeneity of stroke in humans compared to homogeneous strokes in animal models. Even when the international recommendations for preclinical stroke research, the Stroke Academic Industry Roundtable (STAIR) criteria, were followed, we have still seen limited success in the clinic, examples being NXY-059 and haematopoietic growth factors which fulfilled nearly all the STAIR criteria. However, there are a number of neuroprotective treatments under investigation in clinical trials such as hypothermia and ebselen. Moreover, promising neuroprotective treatments based on a deeper understanding of the complex pathophysiology of ischemic stroke such as inhibitors of NADPH oxidases and PSD-95 are currently evaluated in preclinical studies. Further concepts to improve translation include the investigation of neuroprotectants in multicenter preclinical Phase III-type studies, improved animal models, and close alignment between clinical trial and preclinical methodologies. Future successful translation will require both new concepts for preclinical testing and innovative approaches based on mechanistic insights into the ischemic cascade. KW - free radical scavenger KW - ischemic cascade KW - acute ischemic stroke KW - trial KW - focal cerebral-ischemia KW - interleukin-1 receptor antagonist KW - colony-stimulating factor KW - tissue-plasminogen activator KW - traumatic brain injury KW - placebo-controlled KW - alias pilot trial KW - damage cool aid KW - neuroprotection KW - ischemic stroke KW - translation KW - STAIR Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134730 VL - 13 IS - 9 ER - TY - JOUR A1 - Kraft, Peter A1 - Drechsler, Christiane A1 - Gunreben, Ignaz A1 - Heuschmann, Peter Ulrich A1 - Kleinschnitz, Christoph T1 - Regulation of Blood Coagulation Factors XI and XII in Patients with Acute and Chronic Cerebrovascular Disease: A Case-Control Study JF - Cerebrovascular Diseases N2 - Background: Animal models have implicated an integral role for coagulation factors XI (FXI) and XII (FXII) in thrombus formation and propagation of ischemic stroke (IS). However, it is unknown if these molecules contribute to IS pathophysiology in humans, and might be of use as biomarkers for IS risk and severity. This study aimed to identify predictors of altered FXI and FXII levels and to determine whether there are differences in the levels of these coagulation factors between acute cerebrovascular events and chronic cerebrovascular disease (CCD). Methods: In this case-control study, 116 patients with acute ischemic stroke (AIS) or transitory ischemic attack (TIA), 117 patients with CCD, and 104 healthy volunteers (HVs) were enrolled between 2010 and 2013 at our University hospital. Blood sampling was undertaken once in the CCD and HV groups and on days 0, 1, and 3 after stroke onset in patients with AIS or TIA. Correlations between serum FXI and FXII levels and demographic and clinical parameters were tested by linear regression and analysis of variance. Results: The mean age of AIS/TIA patients was 70 ± 12. Baseline clinical severity measured with NIHSS and Barthel Index was 4.8 ± 6.0 and 74 ± 30, respectively. More than half of the patients had an AIS (58%). FXI levels were significantly correlated with different leukocyte subsets (p < 0.05). In contrast, FXII serum levels showed no significant correlation (p > 0.1). Neither FXI nor FXII levels correlated with CRP (p > 0.2). FXII levels were significantly higher in patients with CCD compared with those with AIS/TIA (mean ± SD 106 ± 26% vs. 97 ± 24%; univariate analysis: p < 0.05); these differences did not reach significance in multivariate analysis adjusted for sex and age. FXI levels did not differ significantly between study groups. Sex and age were significantly associated with FXI and/or FXII levels in patients with AIS/TIA (p < 0.05). In contrast, no statistical significant influence was found for treatment modality (thrombolysis or not), pre-treatment with platelet inhibitors, and severity of stroke. Conclusions: In this study, there was no differential regulation of FXI and FXII levels between disease subtypes but biomarker levels were associated with patient and clinical characteristics. FXI and FXII levels might be no valid biomarker for predicting stroke risk. KW - biomarker KW - factor XI KW - factor XII KW - ischemic stroke KW - chronic cerebrovascular disease Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199076 SN - 1015-9770 SN - 1421-9786 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 38 IS - 5 ER - TY - JOUR A1 - Üçeyler, Nurcan A1 - Homola, György A. A1 - González, Hans Guerrero A1 - Kramer, Daniela A1 - Wanner, Christoph A1 - Weidemann, Frank A1 - Solymosi, László A1 - Sommer, Claudia T1 - Increased Arterial Diameters in the Posterior Cerebral Circulation in Men with Fabry Disease N2 - A high load of white matter lesions and enlarged basilar arteries have been shown in selected patients with Fabry disease, a disorder associated with an increased stroke risk. We studied a large cohort of patients with Fabry disease to differentially investigate white matter lesion load and cerebral artery diameters. We retrospectively analyzed cranial magnetic resonance imaging scans of 87 consecutive Fabry patients, 20 patients with ischemic stroke, and 36 controls. We determined the white matter lesion load applying the Fazekas score on fluid-attenuated inversion recovery sequences and measured the diameters of cerebral arteries on 3D-reconstructions of the time-of-flight-MR-angiography scans. Data of different Fabry patient subgroups (males – females; normal – impaired renal function) were compared with data of patients with stroke and controls. A history of stroke or transient ischemic attacks was present in 4/30 males (13%) and 5/57 (9%) females with Fabry disease, all in the anterior circulation. Only one man with Fabry disease showed confluent cerebral white matter lesions in the Fazekas score assessment (1%). Male Fabry patients had a larger basilar artery (p<0.01) and posterior cerebral artery diameter (p<0.05) compared to male controls. This was independent of disease severity as measured by renal function and did not lead to changes in arterial blood flow properties. A basilar artery diameter of >3.2 mm distinguished between men with Fabry disease and controls (sensitivity: 87%, specificity: 86%, p<0.001), but not from stroke patients. Enlarged arterial diameters of the posterior circulation are present only in men with Fabry disease independent of disease severity. KW - Arterial Diameters KW - ischemic stroke KW - magnetic resonance imaging KW - stroke KW - cerebral arteries KW - renal system KW - central nervous system KW - blood flow KW - lesions Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-112614 ER - TY - JOUR A1 - Kraft, Peter A1 - Drechsler, Christiane A1 - Gunreben, Ignaz A1 - Nieswandt, Bernhard A1 - Stoll, Guido A1 - Heuschmann, Peter Ulrich A1 - Kleinschnitz, Christoph T1 - Von Willebrand Factor Regulation in Patients with Acute and Chronic Cerebrovascular Disease: A Pilot, Case-Control Study JF - PLoS ONE N2 - Background and Purpose In animal models, von Willebrand factor (VWF) is involved in thrombus formation and propagation of ischemic stroke. However, the pathophysiological relevance of this molecule in humans, and its potential use as a biomarker for the risk and severity of ischemic stroke remains unclear. This study had two aims: to identify predictors of altered VWF levels and to examine whether VWF levels differ between acute cerebrovascular events and chronic cerebrovascular disease (CCD). Methods A case–control study was undertaken between 2010 and 2013 at our University clinic. In total, 116 patients with acute ischemic stroke (AIS) or transitory ischemic attack (TIA), 117 patients with CCD, and 104 healthy volunteers (HV) were included. Blood was taken at days 0, 1, and 3 in patients with AIS or TIA, and once in CCD patients and HV. VWF serum levels were measured and correlated with demographic and clinical parameters by multivariate linear regression and ANOVA. Results Patients with CCD (158±46%) had significantly higher VWF levels than HV (113±36%, P<0.001), but lower levels than AIS/TIA patients (200±95%, P<0.001). Age, sex, and stroke severity influenced VWF levels (P<0.05). Conclusions VWF levels differed across disease subtypes and patient characteristics. Our study confirms increased VWF levels as a risk factor for cerebrovascular disease and, moreover, suggests that it may represent a potential biomarker for stroke severity, warranting further investigation. KW - cerebrovascular diseases KW - sex addiction KW - biomarkers KW - ischemic stroke KW - blood KW - stroke KW - platelets KW - demography Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119588 SN - 1932-6203 VL - 9 IS - 6 ER - TY - JOUR A1 - Ocak, Gurbey A1 - Drechsler, Christiane A1 - Vossen, Carla Y. A1 - Vos, Hans L. A1 - Rosendaal, Frits R. A1 - Reitsma, Pieter H. A1 - Hoffmann, Michael M. A1 - März, Winfried A1 - Ouwehand, Willem H. A1 - Krediet, Raymond T. A1 - Boeschoten, Elisabeth W. A1 - Dekker, Frido W. A1 - Wanner, Christoph A1 - Verduijn, Marion T1 - Single Nucleotide Variants in the Protein C Pathway and Mortality in Dialysis Patients JF - PLOS ONE N2 - Background: The protein C pathway plays an important role in the maintenance of endothelial barrier function and in the inflammatory and coagulant processes that are characteristic of patients on dialysis. We investigated whether common single nucleotide variants (SNV) in genes encoding protein C pathway components were associated with all-cause 5 years mortality risk in dialysis patients. Methods: Single nucleotides variants in the factor V gene (F5 rs6025; factor V Leiden), the thrombomodulin gene (THBD rs1042580), the protein C gene (PROC rs1799808 and 1799809) and the endothelial protein C receptor gene (PROCR rs867186, rs2069951, and rs2069952) were genotyped in 1070 dialysis patients from the NEtherlands COoperative Study on the Adequacy of Dialysis (NECOSAD) cohort) and in 1243 dialysis patients from the German 4D cohort. Results: Factor V Leiden was associated with a 1.5-fold (95% CI 1.1-1.9) increased 5-year all-cause mortality risk and carriers of the AG/GG genotypes of the PROC rs1799809 had a 1.2-fold (95% CI 1.0-1.4) increased 5-year all-cause mortality risk. The other SNVs in THBD, PROC, and PROCR were not associated with 5-years mortality. Conclusion: Our study suggests that factor V Leiden and PROC rs1799809 contributes to an increased mortality risk in dialysis patients. KW - human brian endothelium KW - factor-V-Leiden KW - venous thrombosis KW - activated receptor-1 KW - vascular access KW - severe sepsis KW - gene polymorphism KW - organ dysfunktion KW - ischemic stroke KW - renal disease Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116265 SN - 1932-6203 VL - 9 IS - 5 ER - TY - JOUR A1 - Hillmann, Steffi A1 - Wiedmann, Silke A1 - Fraser, Alec A1 - Baeza, Juan A1 - Rudd, Anthony A1 - Norrving, Bo A1 - Asplund, Kjell A1 - Niewada, Maciej A1 - Dennis, Martin A1 - Hermanek, Peter A1 - Wolfe, Charles D. A. A1 - Heuschmann, Peter U. T1 - Temporal changes in the quality of acute stroke care in five national audits across Europe JF - BioMed Research International N2 - Background. Data on potential variations in delivery of appropriate stroke care over time are scarce. We investigated temporal changes in the quality of acute hospital stroke care across five national audits in Europe over a period of six years. Methods. Data were derived from national stroke audits in Germany, Poland, Scotland, Sweden, and England/Wales/Northern Ireland participating within the European Implementation Score (EIS) collaboration. Temporal changes in predefined quality indicators with comparable information between the audits were investigated. Multivariable logistic regression analyses were performed to estimate adherence to quality indicators over time. Results. Between 2004 and 2009, individual data from 542,112 patients treated in 538 centers participating continuously over the study period were included. In most audits, the proportions of patients who were treated on a SU, were screened for dysphagia, and received thrombolytic treatment increased over time and ranged from 2-fold to almost 4-fold increase in patients receiving thrombolytic therapy in 2009 compared to 2004. Conclusions. A general trend towards a better quality of stroke care defined by standardized quality indicators was observed over time. The association between introducing a specific measure and higher adherence over time might indicate that monitoring of stroke care performance contributes to improving quality of care. KW - ischemic stroke KW - indicators KW - thrombolysis KW - registries KW - outcomes KW - mortality KW - implementation KW - German Stroke Registers Study Group Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149059 VL - 2015 IS - 432497 ER - TY - JOUR A1 - Kraft, Peter A1 - Drechsler, Christiane A1 - Schuhmann, Michael K. A1 - Gunreben, Ignaz A1 - Kleinschnitz, Christoph T1 - Characterization of Peripheral Immune Cell Subsets in Patients with Acute and Chronic Cerebrovascular Disease: A Case-Control Study JF - International Journal of Molecular Science N2 - Immune cells (IC) play a crucial role in murine stroke pathophysiology. However, data are limited on the role of these cells in ischemic stroke in humans. We therefore aimed to characterize and compare peripheral IC subsets in patients with acute ischemic stroke/transient ischemic attack (AIS/TIA), chronic cerebrovascular disease (CCD) and healthy volunteers (HV). We conducted a case-control study of patients with AIS/TIA (n = 116) or CCD (n = 117), and HV (n = 104) who were enrolled at the University Hospital Würzburg from 2010 to 2013. We determined the expression and quantity of IC subsets in the three study groups and performed correlation analyses with demographic and clinical parameters. The quantity of several IC subsets differed between the AIS/TIA, CCD, and HV groups. Several clinical and demographic variables independently predicted the quantity of IC subsets in patients with AIS/TIA. No significant changes in the quantity of IC subsets occurred within the first three days after AIS/TIA. Overall, these findings strengthen the evidence for a pathophysiologic role of IC in human ischemic stroke and the potential use of IC-based biomarkers for the prediction of stroke risk. A comprehensive description of IC kinetics is crucial to enable the design of targeted treatment strategies. KW - chronic cerebrovascular disease KW - lymphocytes KW - leukocytes KW - immune cells KW - biomarker KW - monocytes KW - regulatory T cells KW - ischemic stroke KW - thromboinflammation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126319 VL - 16 IS - 10 ER - TY - JOUR A1 - Wolf, Karen A1 - Braun, Attila A1 - Haining, Elizabeth J. A1 - Tseng, Yu-Lun A1 - Kraft, Peter A1 - Schuhmann, Michael K. A1 - Gotru, Sanjeev K. A1 - Chen, Wenchun A1 - Hermanns, Heike M. A1 - Stoll, Guido A1 - Lesch, Klaus-Peter A1 - Nieswandt, Bernhard T1 - Partially Defective Store Operated Calcium Entry and Hem(ITAM) Signaling in Platelets of Serotonin Transporter Deficient Mice JF - PLoS One N2 - Background Serotonin (5-hydroxytryptamin, 5-HT) is an indolamine platelet agonist, biochemically derived from tryptophan. 5-HT is secreted from the enterochromaffin cells into the gastrointestinal tract and blood. Blood 5-HT has been proposed to regulate hemostasis by acting as a vasoconstrictor and by triggering platelet signaling through 5-HT receptor 2A (5HTR2A). Although platelets do not synthetize 5-HT, they take 5-HT up from the blood and store it in their dense granules which are secreted upon platelet activation. Objective To identify the molecular composite of the 5-HT uptake system in platelets and elucidate the role of platelet released 5-HT in thrombosis and ischemic stroke. Methods: 5-HT transporter knockout mice (5Htt\(^{-/-}\)) were analyzed in different in vitro and in vivo assays and in a model of ischemic stroke. Results In 5Htt\(^{-/-}\) platelets, 5-HT uptake from the blood was completely abolished and agonist-induced Ca2+ influx through store operated Ca\(^{2+}\) entry (SOCE), integrin activation, degranulation and aggregation responses to glycoprotein VI (GPVI) and C-type lectin-like receptor 2 (CLEC-2) were reduced. These observed in vitro defects in 5Htt\(^{-/-}\) platelets could be normalized by the addition of exogenous 5-HT. Moreover, reduced 5-HT levels in the plasma, an increased bleeding time and the formation of unstable thrombi were observed ex vivo under flow and in vivo in the abdominal aorta and carotid artery of 5Htt\(^{-/-}\) mice. Surprisingly, in the transient middle cerebral artery occlusion (tMCAO) model of ischemic stroke 5Htt\(^{-/-}\) mice showed nearly normal infarct volume and the neurological outcome was comparable to control mice. Conclusion Although secreted platelet 5-HT does not appear to play a crucial role in the development of reperfusion injury after stroke, it is essential to amplify the second phase of platelet activation through SOCE and plays an important role in thrombus stabilization. KW - platelets KW - serotonin KW - integrins KW - blood flow KW - collagens KW - platelet activation KW - platelet aggregation KW - ischemic stroke Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146399 VL - 11 IS - 1 ER - TY - JOUR A1 - Schuhmann, Michael K. A1 - Gunreben, Ignaz A1 - Kleinschnitz, Christoph A1 - Kraft, Peter T1 - Immunohistochemical Analysis of Cerebral Thrombi Retrieved by Mechanical Thrombectomy from Patients with Acute Ischemic Stroke JF - International Journal of Molecular Sciences N2 - Mechanical thrombectomy is a novel treatment option for patients with acute ischemic stroke (AIS). Only a few studies have previously suggested strategies to categorize retrieved clots according to their histologic composition. However, these reports did not analyze potential biomarkers that are of importance in stroke-related inflammation. We therefore histopathologically investigated 37 intracerebral thrombi mechanically retrieved from patients with AIS, and focused on the composition of immune cells and platelets. We also conducted correlation analyses of distinctive morphologic patterns (erythrocytic, serpentine, layered, red, white, mixed appearance) with clinical parameters. Most T cells and monocytes were detected in erythrocytic and red clots, in which the distribution of these cells was random. In contrast, von Willebrand factor (vWF)-positive areas co-localized with regions of fibrin and collagen. While clots with huge amounts of vWF seem to be associated with a high National Institute of Health Stroke Scale score at admission, histologic findings could not predict the clinical outcome at discharge. In summary, we provide the first histologic description of mechanically retrieved intracerebral thrombi regarding biomarkers relevant for inflammation in ischemic stroke. KW - thrombus formation KW - immune cells KW - lymphocytes KW - mechanical thrombectomy KW - ischemic stroke KW - inflammation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166206 VL - 17 IS - 3 ER - TY - JOUR A1 - Krupka, Jennifer A1 - May, Frauke A1 - Weimer, Thomas A1 - Pragst, Ingo A1 - Kleinschnitz, Christoph A1 - Stoll, Guido A1 - Panousis, Con A1 - Dickneite, Gerhard A1 - Nolte, Marc W. T1 - The Coagulation Factor XIIa Inhibitor rHA-Infestin-4 Improves Outcome after Cerebral Ischemia/Reperfusion Injury in Rats JF - PLoS ONE N2 - Background and Purpose Ischemic stroke provokes severe brain damage and remains a predominant disease in industrialized countries. The coagulation factor XII (FXII)-driven contact activation system plays a central, but not yet fully defined pathogenic role in stroke development. Here, we investigated the efficacy of the FXIIa inhibitor rHA-Infestin-4 in a rat model of ischemic stroke using both a prophylactic and a therapeutic approach. Methods For prophylactic treatment, animals were treated intravenously with 100 mg/kg rHA-Infestin-4 or an equal volume of saline 15 min prior to transient middle cerebral artery occlusion (tMCAO) of 90 min. For therapeutic treatment, 100 mg/kg rHA-Infestin-4, or an equal volume of saline, was administered directly after the start of reperfusion. At 24 h after tMCAO, rats were tested for neurological deficits and blood was drawn for coagulation assays. Finally, brains were removed and analyzed for infarct area and edema formation. Results Within prophylactic rHA-Infestin-4 treatment, infarct areas and brain edema formation were reduced accompanied by better neurological scores and survival compared to controls. Following therapeutic treatment, neurological outcome and survival were still improved although overall effects were less pronounced compared to prophylaxis. Conclusions With regard to the central role of the FXII-driven contact activation system in ischemic stroke, inhibition of FXIIa may represent a new and promising treatment approach to prevent cerebral ischemia/reperfusion injury. KW - coagulation factor XIIa KW - ischemic stroke KW - contact activation system KW - FXIIa inhibitor rHA-Infestin Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167370 VL - 11 IS - 1 ER -