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https://www.readbyqxmd.com/read/28646445/update-on-neurocritical-care-of-stroke
#1
Jason Siegel, Michael A Pizzi, J Brent Peel, David Alejos, Nnenne Mbabuike, Benjamin L Brown, David Hodge, W David Freeman
PURPOSE OF REVIEW: This review will highlight the recent advancements in acute ischemic stroke diagnosis and treatment, with special attention to new features and recommendations of stroke care in the neurocritical care unit. RECENT FINDINGS: New studies suggest that pre-hospital treatment of stroke with mobile stroke units and telestroke technology may lead to earlier stroke therapy with intravenous tissue plasminogen activator (tPA), and recent studies show tPA can be given in previously contraindicated situations...
August 2017: Current Cardiology Reports
https://www.readbyqxmd.com/read/28642575/reactive-astrocytes-function-as-phagocytes-after-brain-ischemia-via-abca1-mediated-pathway
#2
Yosuke M Morizawa, Yuri Hirayama, Noubuhiko Ohno, Shinsuke Shibata, Eiji Shigetomi, Yang Sui, Junichi Nabekura, Koichi Sato, Fumikazu Okajima, Hirohide Takebayashi, Hideyuki Okano, Schuichi Koizumi
Astrocytes become reactive following various brain insults; however, the functions of reactive astrocytes are poorly understood. Here, we show that reactive astrocytes function as phagocytes after transient ischemic injury and appear in a limited spatiotemporal pattern. Following transient brain ischemia, phagocytic astrocytes are observed within the ischemic penumbra region during the later stage of ischemia. However, phagocytic microglia are mainly observed within the ischemic core region during the earlier stage of ischemia...
June 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28639721/trpv4-channels-contribute-to-calcium-transients-in-astrocytes-and-neurons-during-peri-infarct-depolarizations-in-a-stroke-model
#3
Cordula Rakers, Matthias Schmid, Gabor C Petzold
Stroke is one of the leading causes of death and long-term disability. In the penumbra, that is, the area surrounding the infarct core, peri-infarct depolarizations (PIDs) are accompanied by strong intracellular calcium elevations in astrocytes and neurons, thereby negatively affecting infarct size and clinical outcome. The dynamics of PIDs and the cellular pathways that are involved during PID formation and progression remain incompletely understood. We have previously shown that inositol triphosphate-gated calcium release from internal stores is a major component of PID-related astroglial calcium signals, but whether external calcium influx through membrane-localized channels also contributes to PIDs has remained unclear...
June 22, 2017: Glia
https://www.readbyqxmd.com/read/28639376/mfat-1-transgene-protects-cultured-adult-neural-stem-cells-against-cobalt-chloride-mediated-hypoxic-injury-by-activating-nrf2-are-pathways
#4
Junfeng Yu, Haiyuan Yang, Bin Fang, Zhengwei Zhang, Ying Wang, Yifan Dai
Ischemic stroke is a devastating neurological disorder and one of the leading causes of death and serious disability in adults. Adult neural stem cell (NSC) replacement therapy is a promising treatment for both structural and functional neurological recovery. However, for the treatment to work, adult NSCs must be protected against hypoxic-ischemic damage in the ischemic penumbra. In the present study, we aimed to investigate the neuroprotective effects of the mfat-1 transgene on cobalt chloride (CoCl2 )-induced hypoxic-ischemic injury in cultured adult NSCs as well as its underlying mechanisms...
June 22, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/28639301/improving-the-detection-sensitivity-of-ph-weighted-amide-proton-transfer-mri-in-acute-stroke-patients-using-extrapolated-semisolid-magnetization-transfer-reference-signals
#5
Hye-Young Heo, Yi Zhang, Tina M Burton, Shanshan Jiang, Yansong Zhao, Peter C M van Zijl, Richard Leigh, Jinyuan Zhou
PURPOSE: To quantify amide protein transfer (APT) effects in acidic ischemic lesions and assess the spatial-temporal relationship among diffusion, perfusion, and pH deficits in acute stroke patients. METHODS: Thirty acute stroke patients were scanned at 3 T. Quantitative APT (APT(#) ) effects in acidic ischemic lesions were measured using an extrapolated semisolid magnetization transfer reference signal technique and compared with commonly used MTRasym (3.5ppm) or APT-weighted parameters...
June 21, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28630234/multiparametric-model-for-penumbral-flow-prediction-in-acute-stroke
#6
Michelle Livne, Tabea Kossen, Vince I Madai, Olivier Zaro-Weber, Walter Moeller-Hartmann, Kim Mouridsen, Wolf-Dieter Heiss, Jan Sobesky
BACKGROUND AND PURPOSE: Identification of salvageable penumbra tissue by dynamic susceptibility contrast magnetic resonance imaging is a valuable tool for acute stroke patient stratification for treatment. However, prior studies have not attempted to combine the different perfusion maps into a predictive model. In this study, we established a multiparametric perfusion imaging model and cross-validated it using positron emission tomography perfusion for detection of penumbral flow. METHODS: In a retrospective analysis of 17 subacute stroke patients with consecutive magnetic resonance imaging and H2O15 positron emission tomography scans, perfusion maps of cerebral blood flow, cerebral blood volume, mean transit time, time-to-maximum, and time-to-peak were constructed and combined using a generalized linear model (GLM)...
June 19, 2017: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/28624329/the-bebig-valencia-type-skin-applicators-dosimetric-study-and-implementation-of-a-dosimetric-hybrid-technique
#7
Georgios Anagnostopoulos, Michael Andrássy, Dimos Baltas
PURPOSE: To determine the relative dose rate distribution in water for the Bebig 20 mm and 30 mm skin applicators and report results in a form suitable for potential clinical use. Results for both skin applicators are also provided in the form of a hybrid Task Group 43 (TG-43) dosimetry technique. Furthermore, the radiation leakage around both skin applicators from the radiation protection point of view and the impact of the geometrical source position uncertainties are studied and reported...
June 14, 2017: Brachytherapy
https://www.readbyqxmd.com/read/28616910/-effects-of-limb-ischemic-postconditioning-on-behavioral-improvement-and-proliferation-of-neural-cells-in-rats-with-transient-cerebral-ischemia
#8
Dan Huang, Hong-Hong Liu, Zhen Yang, Yun Qu
OBJECTIVES: To determine the effects of non-invasive limb ischemic postconditioning (NLIP) on the behavioral performance and the expression and distribution of neural cells in rats with ischemic cortex. METHODS: Rats were randomly divided into 3 groups: sham group (n=10), ischemia/reperfusion (I/R) group (n=50), and NLIP group (n=50). Focal cerebral ischemia was induced by intraluminal MCAO in the rats in the I/R and NLIP groups, while no suture was inserted in the sham-operated rats...
May 2017: Sichuan da Xue Xue Bao. Yi Xue Ban, Journal of Sichuan University. Medical Science Edition
https://www.readbyqxmd.com/read/28600481/optimal-thresholds-for-ischemic-penumbra-predicted-by-computed-tomography-perfusion-in-patients-with-acute-ischemic-stroke-treated-with-mechanical-thrombectomy
#9
Katsuharu Kameda, Junji Uno, Ryosuke Otsuji, Nice Ren, Shintaro Nagaoka, Kazushi Maeda, Yoshiaki Ikai, Hidefuku Gi
BACKGROUND AND PURPOSE: Optimal thresholds for ischemic penumbra detected by CT perfusion (CTP) in patients with acute ischemic stroke (AIS) have not been elucidated. In this study we investigated optimal thresholds for salvageable ischemic penumbra and the risk of hemorrhagic transformation (HT). METHODS: A total of 156 consecutive patients with AIS treated with mechanical thrombectomy (MT) at our hospital were enrolled. Absolute (a) and relative (r) CTP parameters including cerebral blood flow (aCBF and rCBF), cerebral blood volume (aCBV and rCBV), and mean transit time (aMTT and rMTT) were evaluated for their value in detecting ischemic penumbra in each of seven arbitrary regions of interest defined by the major supplying blood vessel...
June 9, 2017: Journal of Neurointerventional Surgery
https://www.readbyqxmd.com/read/28596967/prdx6-upregulation-by-curcumin-attenuates-ischemic-oxidative-damage-via-sp1-in-rats-after-stroke
#10
Gongwei Jia, Botao Tan, Jingxi Ma, Lina Zhang, Xinhao Jin, Changqing Li
BACKGROUND: The role of Peroxiredoxin 6 (Prdx6) in brain ischemia remains unclear. Curcumin (Cur) treatment elicits neuroprotective effects against cerebral ischemic injury, and the associated mechanisms may involve Prdx6. In this study, we investigated whether Prdx6 and the transcription factor specific protein 1 (SP1) were involved in the antioxidant effect of Cur after stoke. METHODS: Focal cerebral ischemic injury was induced by transient middle cerebral artery occlusion for 2 hours in male Sprague-Dawley rats treated with or without Prdx6 siRNA...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28592261/trem2-protects-against-cerebral-ischemia-reperfusion-injury
#11
Rong Wu, Xiangpen Li, Pengfei Xu, Likui Huang, Jinping Cheng, Xiaolong Huang, Jingru Jiang, Long-Jun Wu, Yamei Tang
Although post-ischemic inflammation induced by the innate immune response is considered an essential step in the progression of cerebral ischemia injury, the role of triggering receptor expressed on myeloid cells 2 (TREM2) in the pathogenesis of ischemic stroke remains to be elucidated. Here, we found that the transcriptional and post-transcriptional levels of TREM2 were increased in cultured primary microglia after oxygen-glucose deprivation and reoxygenation and in the ischemic penumbra of the cerebral cortex after middle cerebral artery occlusion (MCAO) and reperfusion in mice...
June 7, 2017: Molecular Brain
https://www.readbyqxmd.com/read/28585287/effect-of-vero-pan-tilt-motion-on-the-dose-distribution
#12
Heru Prasetio, Indra Yohannes, Christoph Bert
Tumor tracking is an option for intra-fractional motion management in radiotherapy. The VERO gimbal tracking system creates a unique beam geometry and understanding the effect of the gimbal motion in terms of dose distribution is important to assess the dose deviation from the reference conditions. Beam profiles, output factors (OF) and percentage depth doses (PDD) were measured and evaluated to investigate this effect. In order to find regions affected by the pan-tilt motion, synthesized 2D dose distributions were generated...
June 6, 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28584682/safe-time-duration-for-temporary-middle-cerebral-artery-occlusion-in-aneurysm-surgery-based-on-motor-evoked-potential-monitoring
#13
Jun Tanabe, Tatsuya Ishikawa, Junta Moroi
BACKGROUND: Temporary vessel occlusion of the parent artery is an essential technique for aneurysm surgery. Our aim was to clarify the safe time for temporary occlusion for aneurysm surgery, that is the "safe time duration" (STD), in which brain tissue exposed to ischemia will almost never fall into even the ischemic penumbra during temporary occlusion of the middle cerebral artery (MCA), and even transient postoperative motor impairment will be rare using intraoperative motor-evoked potentials (MEP)...
2017: Surgical Neurology International
https://www.readbyqxmd.com/read/28577823/the-effectiveness-of-penumbra-400-micro-coils-in-the-embolization-of-large-cerebral-aneurysms
#14
Tadeusz Jan Popiela, Paweł Brzegowy, Bartłomiej Łasocha, Andrzej Urbanik
BACKGROUND: The objective of this work is to analyze the effectiveness of Penumbra 400 micro-coils in the embolization of large cerebral aneurysms. MATERIAL AND METHODS: A retrospective analysis has been conducted in a group of 32 patients at the average age of 54.5 years (30-84) for whose embolization the P400 micro-coils (P400) have been used. A control group consisted of 44 patients at the average age of 52.7 years (24-82) in whose aneurysm embolization the 18 micro-coils (MC) have been utilized...
May 18, 2017: Neurologia i Neurochirurgia Polska
https://www.readbyqxmd.com/read/28569122/rationale-and-design-of-combination-of-an-immune-modulator-fingolimod-with-alteplase-bridging-with-mechanical-thrombectomy-in-acute-ischemic-stroke-famtais-trial
#15
Sheng Zhang, Ying Zhou, Ruiting Zhang, Meixia Zhang, Bruce Campbell, Longting Lin, Fu-Dong Shi, Min Lou
Rationale In acute ischemic stroke patients with large vessel occlusion, although reperfusion within 6 h after stroke onset using combined intravenous alteplase and mechanical thrombectomy (bridging therapy) can improve functional outcome, still approximately 50% patients suffer disability which may result from reperfusion injury. Proof-of-concept clinical trials have indicated that the sphingosine-1-phosphate receptor modulator fingolimod may be efficacious in attenuating brain inflammation and improving clinical outcomes in acute ischemic stroke patients as a single therapy beyond 4...
January 1, 2017: International Journal of Stroke: Official Journal of the International Stroke Society
https://www.readbyqxmd.com/read/28557800/lateral-variations-of-radiobiological-properties-of-therapeutic-fields-of-sup-1-sup-h-sup-4-sup-he-sup-12-sup-c-and-sup-16-sup-o-ions-studied-with-geant4-and-microdosimetric-kinetic-model
#16
Sophie Dewey, Lucas Burigo, Igor A Pshenichnov, Igor Mishustin, Marcus Bleicher
As known, in cancer therapy with ion beams the relative biological effectiveness (RBE) of ions changes in the course of their propagation in tissues. Such changes are caused not only by increasing the linear energy transfer (LET) of beam particles with the penetration depth towards the Bragg peak, but also by nuclear reactions induced by beam nuclei leading to the production of various secondary particles. Although the changes of RBE along the beam axis have been studied quite well, much less attention has been paid to the evolution of RBE in the transverse direction, perpendicular to the beam axis...
May 30, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28556241/carbon-and-oxygen-minibeam-radiation-therapy-an-experimental-dosimetric-evaluation
#17
Immaculada Martínez-Rovira, Wilfredo González, Stephan Brons, Yolanda Prezado
PURPOSE: To perform dosimetric characterization of a minibeam collimator in both carbon and oxygen ion beams to guide optimal set up geometry and irradiation for future radiobiological studies using these beams. METHODS: Carbon and oxygen minibeams were generated using a prototype tungsten multislit collimator presenting line apertures 700 μm wide, which are spaced 3500 μm centre-to-centre distance apart. Several radiation beam spots generated the desired field size of 15X15 mm(2) and production of a 50 mm long spread out Bragg peak (SOBP) centered at 80 mm-depth in water...
May 29, 2017: Medical Physics
https://www.readbyqxmd.com/read/28551596/pure-posterior-communicating-artery-occlusion-treated-with-mechanical-thrombectomy
#18
Ryosuke Otsuji, Katsuharu Kameda, Junji Uno, Hidefuku Gi
There has been no report of mechanical thrombectomy for a pure posterior communicating artery (PComA) occlusion. Here, we report the case of an 87-year-old woman with a disturbance of consciousness and left hemiparesis diagnosed with a right PComA occlusion. The patient was successfully treated using mechanical thrombectomy in combination with a stent retriever and the Penumbra system. A CT perfusion image showed cerebral blood flow reduction in the ipsilateral occipital lobe and thalamus. A CT angiography supported the diagnosis of an occlusion of fetal type PComA...
May 27, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28547529/toll-like-receptor-4-tlr4-and-triggering-receptor-expressed-on-myeloid-cells-2-trem-2-activation-balance-astrocyte-polarization-into-a-proinflammatory-phenotype
#19
Gerardo Rosciszewski, Vanesa Cadena, Veronica Murta, Jeronimo Lukin, Alejandro Villarreal, Thierry Roger, Alberto Javier Ramos
Astrocytes react to brain injury with a generic response known as reactive gliosis, which involves activation of multiple intracellular pathways including several that may be beneficial for neuronal survival. However, by unknown mechanisms, reactive astrocytes can polarize into a proinflammatory phenotype that induces neurodegeneration. In order to study reactive gliosis and astroglial polarization into a proinflammatory phenotype, we used cortical devascularization-induced brain ischemia in Wistar rats and primary astroglial cell cultures exposed to oxygen-glucose deprivation (OGD)...
May 25, 2017: Molecular Neurobiology
https://www.readbyqxmd.com/read/28545556/finer-leaf-resolution-and-steeper-beam-edges-using-a-virtual-isocentre-in-concurrence-to-ptv-shaped-collimators-in-standard-distance-a-planning-study
#20
Klaus Bratengeier, Barbara Herzog, Sonja Wegener, Kostyantyn Holubyev
PURPOSE: Investigation of a reduced source to target distance to improve organ at risk sparing during stereotactic irradiation (STX). METHODS: The authors present a planning study with perfectly target-volume adapted collimator compared with multi-leaf collimator (MLC) at reduced source to virtual isocentre distance (SVID) in contrast to normal source to isocentre distance (SID) for stereotactic applications. The role of MLC leaf width and 20-80% penumbra was examined concerning the healthy tissue sparing...
May 25, 2017: Radiation Oncology
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