@article{PhamHelluyKleinschnitzetal.2011, author = {Pham, Mirko and Helluy, Xavier and Kleinschnitz, Christoph and Kraft, Peter and Bartsch, Andreas J. and Jakob, Peter and Nieswandt, Bernhard and Bendszus, Martin and Guido, Stoll}, title = {Sustained Reperfusion after Blockade of Glycoprotein-Receptor-Ib in Focal Cerebral Ischemia: An MRI Study at 17.6 Tesla}, series = {PLoS ONE}, volume = {6}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0018386}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142608}, pages = {e18386}, year = {2011}, abstract = {Background: Inhibition of early platelet adhesion by blockade of glycoprotein-IB (GPIb) protects mice from ischemic stroke. To elucidate underlying mechanisms in-vivo, infarct development was followed by ultra-high field MRI at 17.6 Tesla. Methods: Cerebral infarction was induced by transient-middle-cerebral-artery-occlusion (tMCAO) for 1 hour in C57/BL6 control mice (N = 10) and mice treated with 100 mg Fab-fragments of the GPIb blocking antibody p0p/B 1 h after tMCAO (N = 10). To control for the effect of reperfusion, additional mice underwent permanent occlusion and received anti-GPIb treatment (N = 6; pMCAO) or remained without treatment (N = 3; pMCAO). MRI 2 h and 24 h after MCAO measured cerebral-blood-flow (CBF) by continuous arterial-spin labelling, the apparent-diffusion-coefficient (ADC), quantitative-T2 and T2-weighted imaging. All images were registered to a standard mouse brain MRI atlas and statistically analysed voxel-wise, and by cortico-subcortical ROI analysis. Results: Anti-GPIb treatment led to a relative increase of postischemic CBF vs. controls in the cortical territory of the MCA (2 h: 44.2 +/- 6.9 ml/100g/min versus 24 h: 60.5 +/- 8.4; p = 0.0012, F((1,18)) = 14.63) after tMCAO. Subcortical CBF 2 h after tMCAO was higher in anti-GPIb treated animals (45.3 +/- 5.9 vs. controls: 33.6 +/- 4.3; p = 0.04). In both regions, CBF findings were clearly related to a lower probability of infarction (Cortex/Subcortex of treated group: 35\%/65\% vs. controls: 95\%/100\%) and improved quantitative-T2 and ADC. After pMCAO, anti-GPIb treated mice developed similar infarcts preceded by severe irreversible hypoperfusion as controls after tMCAO indicating dependency of stroke protection on reperfusion. Conclusion: Blockade of platelet adhesion by anti-GPIb-Fab-fragments results in substantially improved CBF early during reperfusion. This finding was in exact spatial correspondence with the prevention of cerebral infarction and indicates in-vivo an increased patency of the microcirculation. Thus, progression of infarction during early ischemia and reperfusion can be mitigated by anti-platelet treatment.}, language = {en} } @article{PhamHelluyBraeuningeretal.2010, author = {Pham, Mirko and Helluy, X. and Braeuninger, S. and Jakob, P. and Stoll, G. and Kleinschnitz, Christoph and Bendszus, M.}, title = {Outcome of experimental stroke in C57Bl/6 and Sv/129 mice assessed by multimodal ultra-high field MRI}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-68115}, year = {2010}, abstract = {Transgenic mice bred on C57Bl/6 or Sv/129 genetic background are frequently used in stroke research. It is well established that variations in cerebrovascular anatomy and hemodynamics can influence stroke outcome in different inbred mouse lines. We compared stroke development in C57Bl/6 and Sv/129 mice in the widely used model of transient middle cerebral artery occlusion (tMCAO) by multimodal ultra-high field magnetic resonance imaging (MRI). C57Bl/6 and Sv/129 mice underwent 60 min of tMCAO and were analyzed by MRI 2 h and 24 h afterwards. Structural and functional images were registered to a standard anatomical template. Probability maps of infarction were rendered by automated segmentation from quantitative T2-relaxometric images. Whole-brain segmentation of infarction was accomplished manually on high-resolution T2-weighted (T2-w) RARE images. Cerebral perfusion (cerebral blood flow, CBF) was measured quantitatively by modified continuous arterial-spin-labeling (CASL) and apparent diffusion coefficients (ADC) by spin-echo diffusion-weighted imaging (DWI). Probabilities of cortical (95.1\% ± 3.1 vs. 92.1\% ± 2.5; p > 0.05) and subcortical (100\% vs. 100\%; p > 0.05) infarctions at 24 h were similar in both groups as was the whole-brain volumetric extent of cerebral infarction. In addition, CBF and ADC values did not differ between C57Bl/6 and Sv/129 mice at any time point or region of interest. The C57Bl/6 and Sv/129 genetic background is no major confounding factor of infarct size and cerebral perfusion in the tMCAO model.}, subject = {NMR-Tomographie}, language = {en} } @article{KunzePhamRaslanetal.2012, author = {Kunze, Ekkehard and Pham, Mirko and Raslan, Furat and Stetter, Christian and Lee, Jin-Yul and Solymosi, Laszlo and Ernestus, Ralf-Ingo and Hamilton Vince, Giles and Westermaier, Thomas}, title = {Value of Perfusion CT, Transcranial Doppler Sonography and Neurological Examination to detect delayed Vasospasm after aneurysmal Subarachnoid Hemorrhage [Research Article]}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76241}, year = {2012}, abstract = {Background If detected in time, delayed cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) may be treated by balloon angioplasty or chemical vasospasmolysis in order to enhance cerebral blood flow (CBF) and protect the brain from ischemic damage. This study was conceived to compare the diagnostic accuracy of detailed neurological examination, Transcranial Doppler Sonography (TCD), and Perfusion-CT (PCT) to detect angiographic vasospasm. Methods The sensitivity, specificity, positive and negative predictive values of delayed ischemic neurological deterioration (DIND), pathological findings on PCT- maps, and accelerations of the mean flow velocity (MVF) were calculated. Results The accuracy of DIND to predict angiographic vasospasm was 0.88. An acceleration of MFV in TCD (>140 cm/s) had an accuracy of 0.64, positive PCT-findings of 0.69 with a higher sensitivity, and negative predictive value than TCD. Interpretation Neurological assessment at close intervals is the most sensitive and specific parameter for cerebral vasospasm. PCT has a higher accuracy, sensitivity and negative predictive value than TCD. If detailed neurological evaluation is possible, it should be the leading parameter in the management and treatment decisions. If patients are not amenable to detailed neurological examination, PCT at regular intervals is a helpful tool to diagnose secondary vasospasm after aneurysmal SAH.}, subject = {Medizin}, language = {en} } @article{VogtKollikowskiWeidneretal.2022, author = {Vogt, Marius L. and Kollikowski, Alexander M. and Weidner, Franziska and Strinitz, Marc and Feick, J{\"o}rn and Essig, Fabian and Neugebauer, Herrmann and Haeusler, Karl Georg and Pham, Mirko and Maerz, Alexander}, title = {Safety and Effectiveness of the New Generation APERIO® Hybrid Stent-retriever Device in Large Vessel Occlusion Stroke}, series = {Clinical Neuroradiology}, volume = {32}, journal = {Clinical Neuroradiology}, number = {1}, doi = {10.1007/s00062-021-01122-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264817}, pages = {141-151}, year = {2022}, abstract = {Background It is unknown whether technological advancement of stent-retriever devices influences typical observational indicators of safety or effectiveness. Methods Observational retrospective study of APERIO® (AP) vs. new generation APERIO® Hybrid (APH) (Acandis®, Pforzheim, Germany) stent-retriever device (01/2019-09/2020) for mechanical thrombectomy (MT) in large vessel occlusion (LVO) stroke. Primary effectiveness endpoint was successful recanalization eTICI (expanded Thrombolysis In Cerebral Ischemia) ≥ 2b67, primary safety endpoint was occurrence of hemorrhagic complications after MT. Secondary outcome measures were time from groin puncture to first pass and successful reperfusion, and the total number of passes needed to achieve the final recanalization result. Results A total of 298 patients with LVO stroke who were treated by MT matched the inclusion criteria: 148 patients (49.7\%) treated with AP vs. 150 patients (50.3\%) treated with new generation APH. Successful recanalization was not statistically different between both groups: 75.7\% for AP vs. 79.3\% for APH; p = 0.450. Postinterventional hemorrhagic complications and particularly subarachnoid hemorrhage as the entity possibly associated with stent-retriever device type was significantly less frequent in the group treated with the APH: 29.7\% for AP and 16.0\% for APH; p = 0.005; however, rates of symptomatic hemorrhage with clinical deterioration and in domo mortality were not statistically different. Neither the median number of stent-retriever passages needed to achieve final recanalization, time from groin puncture to first pass, time from groin puncture to final recanalization nor the number of cases in which successful recanalization could only be achieved by using a different stent-retriever as bail-out device differed between both groups. Conclusion In the specific example of the APERIO® stent-retriever device, we observed that further technological developments of the new generation device were not associated with disadvantages with respect to typical observational indicators of safety or effectiveness.}, language = {en} } @article{EssigBabilonVollmuthetal.2021, author = {Essig, Fabian and Babilon, Lilith and Vollmuth, Christoph and Kollikowski, Alexander M. and Pham, Mirko and Solymosi, L{\´a}szl{\´o} and Haeusler, Karl Georg and Kraft, Peter and Stoll, Guido and Schuhmann, Michael K.}, title = {High mobility group box 1 protein in cerebral thromboemboli}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {20}, issn = {1422-0067}, doi = {10.3390/ijms222011276}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265568}, year = {2021}, abstract = {High-mobility group box 1 protein (HMGB1) is a damage-associated molecular pattern (DAMP) involved in neutrophil extracellular trap (NET) formation and thrombosis. NETs are regularly found in cerebral thromboemboli. We here analyzed associated HMGB1 expression in human thromboemboli retrieved via mechanical thrombectomy from 37 stroke patients with large vessel occlusion. HMGB1 was detected in all thromboemboli, accounting for 1.7\% (IQR 0.6-6.2\%) of the total thromboemboli area and was found to be colocalized with neutrophils and NETs and in spatial proximity to platelets. Correlation analysis revealed that the detection of HMGB1 was strongly related to the number of neutrophils (r = 0.58, p = 0.0002) and platelets (r = 0.51, p = 0.001). Our results demonstrate that HMGB1 is a substantial constituent of thromboemboli causing large vessel occlusion stroke.}, language = {en} } @article{TraubOttoSelletal.2022, author = {Traub, Jan and Otto, Markus and Sell, Roxane and G{\"o}pfert, Dennis and Homola, Gy{\"o}rgy and Steinacker, Petra and Oeckl, Patrick and Morbach, Caroline and Frantz, Stefan and Pham, Mirko and St{\"o}rk, Stefan and Stoll, Guido and Frey, Anna}, title = {Serum phosphorylated tau protein 181 and neurofilament light chain in cognitively impaired heart failure patients}, series = {Alzheimer's Research \& Therapy}, volume = {14}, journal = {Alzheimer's Research \& Therapy}, doi = {10.1186/s13195-022-01087-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300515}, year = {2022}, abstract = {Background Chronic heart failure (HF) is known to increase the risk of developing Alzheimer's dementia significantly. Thus, detecting and preventing mild cognitive impairment, which is common in patients with HF, is of great importance. Serum biomarkers are increasingly used in neurological disorders for diagnostics, monitoring, and prognostication of disease course. It remains unclear if neuronal biomarkers may help detect cognitive impairment in this high-risk population. Also, the influence of chronic HF and concomitant renal dysfunction on these biomarkers is not well understood. Methods Within the monocentric Cognition.Matters-HF study, we quantified the serum levels of phosphorylated tau protein 181 (pTau) and neurofilament light chain (NfL) of 146 extensively phenotyped chronic heart failure patients (aged 32 to 85 years; 15.1\% women) using ultrasensitive bead-based single-molecule immunoassays. The clinical work-up included advanced cognitive testing and cerebral magnetic resonance imaging (MRI). Results Serum concentrations of NfL ranged from 5.4 to 215.0 pg/ml (median 26.4 pg/ml) and of pTau from 0.51 to 9.22 pg/ml (median 1.57 pg/ml). We detected mild cognitive impairment (i.e., T-score < 40 in at least one cognitive domain) in 60\% of heart failure patients. pTau (p = 0.014), but not NfL, was elevated in this group. Both NfL (ρ = - 0.21; p = 0.013) and pTau (ρ = - 0.25; p = 0.002) related to the cognitive domain visual/verbal memory, as well as white matter hyperintensity volume and cerebral and hippocampal atrophy. In multivariable analysis, both biomarkers were independently influenced by age (T = 4.6 for pTau; T = 5.9 for NfL) and glomerular filtration rate (T = - 2.4 for pTau; T = - 3.4 for NfL). Markers of chronic heart failure, left atrial volume index (T = 4.6) and NT-proBNP (T = 2.8), were further cardiological determinants of pTau and NfL, respectively. In addition, pTau was also strongly affected by serum creatine kinase levels (T = 6.5) and ferritin (T = - 3.1). Conclusions pTau and NfL serum levels are strongly influenced by age-dependent renal and cardiac dysfunction. These findings point towards the need for longitudinal examinations and consideration of frequent comorbidities when using neuronal serum biomarkers.}, language = {en} } @article{BieberFoersterHaefelietal.2021, author = {Bieber, Michael and Foerster, Kathrin I. and Haefeli, Walter E. and Pham, Mirko and Schuhmann, Michael K. and Kraft, Peter}, title = {Treatment with edoxaban attenuates acute stroke severity in mice by reducing blood-brain barrier damage and inflammation}, series = {International Journal of Molecular Sciences}, volume = {22}, journal = {International Journal of Molecular Sciences}, number = {18}, issn = {1422-0067}, doi = {10.3390/ijms22189893}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284481}, year = {2021}, abstract = {Patients with atrial fibrillation and previous ischemic stroke (IS) are at increased risk of cerebrovascular events despite anticoagulation. In these patients, treatment with non-vitamin K oral anticoagulants (NOAC) such as edoxaban reduced the probability and severity of further IS without increasing the risk of major bleeding. However, the detailed protective mechanism of edoxaban has not yet been investigated in a model of ischemia/reperfusion injury. Therefore, in the current study we aimed to assess in a clinically relevant setting whether treatment with edoxaban attenuates stroke severity, and whether edoxaban has an impact on the local cerebral inflammatory response and blood-brain barrier (BBB) function after experimental IS in mice. Focal cerebral ischemia was induced by transient middle cerebral artery occlusion in male mice receiving edoxaban, phenprocoumon or vehicle. Infarct volumes, functional outcome and the occurrence of intracerebral hemorrhage were assessed. BBB damage and the extent of local inflammatory response were determined. Treatment with edoxaban significantly reduced infarct volumes and improved neurological outcome and BBB function on day 1 and attenuated brain tissue inflammation. In summary, our study provides evidence that edoxaban might exert its protective effect in human IS by modulating different key steps of IS pathophysiology, but further studies are warranted.}, language = {en} } @article{HaarmannVollmuthKollikowskietal.2023, author = {Haarmann, Axel and Vollmuth, Christoph and Kollikowski, Alexander M. and Heuschmann, Peter U. and Pham, Mirko and Stoll, Guido and Neugebauer, Hermann and Schuhmann, Michael K.}, title = {Vasoactive soluble endoglin: a novel biomarker indicative of reperfusion after cerebral large-vessel occlusion}, series = {Cells}, volume = {12}, journal = {Cells}, number = {2}, issn = {2073-4409}, doi = {10.3390/cells12020288}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304995}, year = {2023}, abstract = {Now that mechanical thrombectomy has substantially improved outcomes after large-vessel occlusion stroke in up to every second patient, futile reperfusion wherein successful recanalization is not followed by a favorable outcome is moving into focus. Unfortunately, blood-based biomarkers, which identify critical stages of hemodynamically compromised yet reperfused tissue, are lacking. We recently reported that hypoxia induces the expression of endoglin, a TGF-β co-receptor, in human brain endothelium in vitro. Subsequent reoxygenation resulted in shedding. Our cell model suggests that soluble endoglin compromises the brain endothelial barrier function. To evaluate soluble endoglin as a potential biomarker of reperfusion (-injury) we analyzed its concentration in 148 blood samples of patients with acute stroke due to large-vessel occlusion. In line with our in vitro data, systemic soluble endoglin concentrations were significantly higher in patients with successful recanalization, whereas hypoxia alone did not induce local endoglin shedding, as analyzed by intra-arterial samples from hypoxic vasculature. In patients with reperfusion, higher concentrations of soluble endoglin additionally indicated larger infarct volumes at admission. In summary, we give translational evidence that the sequence of hypoxia and subsequent reoxygenation triggers the release of vasoactive soluble endoglin in large-vessel occlusion stroke and can serve as a biomarker for severe ischemia with ensuing recanalization/reperfusion.}, language = {en} } @article{GuggenbergerVogtSongetal.2023, author = {Guggenberger, Konstanze V. and Vogt, Marius L. and Song, Jae W. and Weng, Andreas M. and Fr{\"o}hlich, Matthias and Schmalzing, Marc and Venhoff, Nils and Hillenkamp, Jost and Pham, Mirko and Meckel, Stephan and Bley, Thorsten A.}, title = {Intraorbital findings in giant cell arteritis on black blood MRI}, series = {European Radiology}, volume = {33}, journal = {European Radiology}, number = {4}, doi = {10.1007/s00330-022-09256-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324978}, pages = {2529-2535}, year = {2023}, abstract = {Objective Blindness is a feared complication of giant cell arteritis (GCA). However, the spectrum of pathologic orbital imaging findings on magnetic resonance imaging (MRI) in GCA is not well understood. In this study, we assess inflammatory changes of intraorbital structures on black blood MRI (BB-MRI) in patients with GCA compared to age-matched controls. Methods In this multicenter case-control study, 106 subjects underwent BB-MRI. Fifty-six patients with clinically or histologically diagnosed GCA and 50 age-matched controls without clinical or laboratory evidence of vasculitis were included. All individuals were imaged on a 3-T MR scanner with a post-contrast compressed-sensing (CS) T1-weighted sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) BB-MRI sequence. Imaging results were correlated with available clinical symptoms. Results Eighteen of 56 GCA patients (32\%) showed inflammatory changes of at least one of the intraorbital structures. The most common finding was enhancement of at least one of the optic nerve sheaths (N = 13, 72\%). Vessel wall enhancement of the ophthalmic artery was unilateral in 8 and bilateral in 3 patients. Enhancement of the optic nerve was observed in one patient. There was no significant correlation between imaging features of inflammation and clinically reported orbital symptoms (p = 0.10). None of the age-matched control patients showed any inflammatory changes of intraorbital structures. Conclusions BB-MRI revealed inflammatory findings in the orbits in up to 32\% of patients with GCA. Optic nerve sheath enhancement was the most common intraorbital inflammatory change on BB-MRI. MRI findings were independent of clinically reported orbital symptoms. Key Points • Up to 32\% of GCA patients shows signs of inflammation of intraorbital structures on BB-MRI. • Enhancement of the optic nerve sheath is the most common intraorbital finding in GCA patients on BB-MRI. • Features of inflammation of intraorbital structures are independent of clinically reported symptoms.}, language = {en} } @article{TraubOttoSelletal.2022, author = {Traub, Jan and Otto, Markus and Sell, Roxane and Homola, Gy{\"o}rgy A. and Steinacker, Petra and Oeckl, Patrick and Morbach, Caroline and Frantz, Stefan and Pham, Mirko and St{\"o}rk, Stefan and Stoll, Guido and Frey, Anna}, title = {Serum glial fibrillary acidic protein indicates memory impairment in patients with chronic heart failure}, series = {ESC Heart Failure}, volume = {9}, journal = {ESC Heart Failure}, number = {4}, doi = {10.1002/ehf2.13986}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312736}, pages = {2626-2634}, year = {2022}, abstract = {Aims Cognitive dysfunction occurs frequently in patients with heart failure (HF), but early detection remains challenging. Serum glial fibrillary acidic protein (GFAP) is an emerging biomarker of cognitive decline in disorders of primary neurodegeneration such as Alzheimer's disease. We evaluated the utility of serum GFAP as a biomarker for cognitive dysfunction and structural brain damage in patients with stable chronic HF. Methods and results Using bead-based single molecule immunoassays, we quantified serum levels of GFAP in patients with HF participating in the prospective Cognition.Matters-HF study. Participants were extensively phenotyped, including cognitive testing of five separate domains and magnetic resonance imaging (MRI) of the brain. Univariable and multivariable models, also accounting for multiple testing, were run. One hundred and forty-six chronic HF patients with a mean age of 63.8 ± 10.8 years were included (15.1\% women). Serum GFAP levels (median 246 pg/mL, quartiles 165, 384 pg/mL; range 66 to 1512 pg/mL) did not differ between sexes. In the multivariable adjusted model, independent predictors of GFAP levels were age (T = 5.5; P < 0.001), smoking (T = 3.2; P = 0.002), estimated glomerular filtration rate (T = -4.7; P < 0.001), alanine aminotransferase (T = -2.1; P = 0.036), and the left atrial end-systolic volume index (T = 3.4; P = 0.004). NT-proBNP but not serum GFAP explained global cerebral atrophy beyond ageing. However, serum GFAP levels were associated with the cognitive domain visual/verbal memory (T = -3.0; P = 0.003) along with focal hippocampal atrophy (T = 2.3; P = 0.025). Conclusions Serum GFAP levels are affected by age, smoking, and surrogates of the severity of HF. The association of GFAP with memory dysfunction suggests that astroglial pathologies, which evade detection by conventional MRI, may contribute to memory loss beyond ageing in patients with chronic HF.}, language = {en} }