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Berta Puig, Santra Brenna, Tim Magnus
When a main artery of the brain occludes, a cellular response involving multiple cell types follows. Cells directly affected by the lack of glucose and oxygen in the neuronal core die by necrosis. In the periphery surrounding the ischemic core (the so-called penumbra) neurons, astrocytes, microglia, oligodendrocytes, pericytes, and endothelial cells react to detrimental factors such as excitotoxicity, oxidative stress, and inflammation in different ways. The fate of the neurons in this area is multifactorial, and communication between all the players is important for survival...
September 19, 2018: International Journal of Molecular Sciences
A Beuter, A Balossier, S Trofimchuk, V Volpert
Following a stroke, cortical networks in the penumbra area become fragmented and partly deactivated. We develop a model to study the propagation of waves of electric potential in the cortical tissue with integro-differential equations arising in neural field models. The wave speed is characterized by the tissue excitability and connectivity determined through parameters of the model. Post-stroke tissue damage in the penumbra area creates a hypoconnectivity and decreases the speed of wave propagation. It is proposed that external stimulation could restore the wave speed in the penumbra area under certain conditions of the parameters...
September 15, 2018: Mathematical Biosciences
Kunal Vakharia, Gursant S Atwal, Elad I Levy
Acute ischemic thrombosis in patients who have undergone neurosurgical procedures is a leading cause of mortality and long-term disability. Endovascular therapy has become an important treatment modality for acute ischemic thrombosis in these patients. Noninvasive imaging has dramatically changed the understanding of cerebral blood flow and the concepts of cerebrovascular reserve and salvageable penumbra. Increasingly, reliance on perfusion imaging to discern tissue viability and potential outcomes has become standard of care...
October 2018: Neurosurgery Clinics of North America
Yi Fang, Daoli Jiang, Yitong Wang, Qian Wang, Dongmei Lv, Jichao Liu, Chang Liu
Preclinical Research & Development The purpose of the present study is to evaluate the neuroprotective effect of recombinant human glucagon-like peptide-1 (rhGLP-1) as well as to explore corresponding mechanisms in diabetic rats with cerebral ischemia/reperfusion injury induced by middle cerebral artery occlusion (MCAO). Diabetes mellitus was induced by intraperitoneal injection of streptozotocin. The rats were pretreated with rhGLP-1 (20 μg/kg intraperitoneally, thrice a day) for 14 days. Thereafter, the rats were subjected to MCAO 90 min/reperfusion 24 hr...
September 17, 2018: Drug Development Research
Zhen-Zhen Chen, Xin Gong, Qi Guo, Hui Zhao, Lei Wang
ETHNOPHARMACOLOGICAL RELEVANCE: Bu Yang Huan Wu Decoction (BYHW) is a famous traditional Chinese medicine (TCM) formula used in China for the treatment of cerebral ischemic stroke. But the protective effects and underlining mechanisms of BYHW remain unclear. AIM OF THE STUDY: This study was designed to investigate the protective effects and underlining signaling mechanisms of BYHW on brain tissues in a rat model of cerebral ischemic reperfusion (I/R) injury. MATERIALS AND METHODS: Liquid chromatography was used to verify the composition of BYHW...
September 12, 2018: Journal of Ethnopharmacology
Jae Pil Chung, Young Min Seong, Tae Yeon Kim, Yona Choi, Tae Hoon Kim, Hyun Joon Choi, Chul Hee Min, Hamza Benmakhlouf, Kook Jin Chun, Hyun-Tai Chung
BACKGROUND: To measure the absorbed dose rate to water and penumbra of a Gamma Knife® (GK) using a polymethyl metacrylate (PMMA) phantom. METHODS: A multi-purpose PMMA phantom was developed to measure the absorbed dose rate to water and the dose distribution of a GK. The phantom consists of a hemispherical outer phantom, one exchangeable cylindrical chamber-hosting inner phantom, and two film-hosting inner phantoms. The radius of the phantom was determined considering the electron density of the PMMA such that it corresponds to 8 g/cm2 water depth, which is the reference depth of the absorbed dose measurement of GK...
September 14, 2018: Radiation Oncology
Zhanqin Zhang, Zhi Ma, Chaoying Yan, Kairui Pu, Meiyan Wu, Juan Bai, Yansong Li, Qiang Wang
The available evidence showed that mitochondrial transfer by releasing the extracellular vesicles containing mitochondria from astrocytes to neurons exerted a neuroprotective effect after stroke. Whether extracellular mitochondrial replenishment could rescue the tissues from cerebral ischemic injury still needs to be explored completely. It was hypothesized that the augmentation of mitochondrial damage after cerebral ischemia could be resolved by timely replenishment of exogenous mitochondria. A stroke model of middle cerebral artery occlusion (MCAO) was used in this study to verify this hypothesis...
September 10, 2018: Behavioural Brain Research
Emőke Horváth, Adina Huțanu, Liviu Chiriac, Minodora Dobreanu, Alex Orădan, Előd-Ernő Nagy
Clinical and experimental observations emphasize that inflammation is a direct risk factor for stroke. We performed a detailed histological and immunohistochemical analysis, assisted by digital morphometry, to compare the representative brain lesions in the ischemic core and penumbra in a rat model. Focal neuronal necrosis and degeneration were significantly more intense in the core, whereas inflammatory infiltration, MPO, CD68, CD3, FXIII, Cox-2, iNOS2, Arg-1 expressions were stronger in the penumbra. Our findings indicate that neuroinflammation affects the penumbra more than the core and suggest that targeted modulation of the cellular infiltrate could be exploited to save brain volume...
August 9, 2018: Journal of Neuroimmunology
Carla Winterhalter, Antony John Lomax, David Oxley, Damien Charles Weber, Sairos Safai
We read with interest the study by (Bäumer et al., 2018), in particular that their conclusions are in contrast to those of our earlier paper (Winterhalter et al., 2018), namely that positioning the collimating aperture downstream of the range shifter leads to a superior penumbra. In contrast, we found sharper penumbras for the PSI scanning Gantry when the aperture is positioned upstream of the range shifter. We have run additional Monte Carlo simulations with components derived from the paper of (Bäumer et al...
September 12, 2018: Physics in Medicine and Biology
Miyuki Tauchi, Maria Mercedes Tejada de Rink, Hiroshi Fujioka, Satoko Okayama, Kei-Ichiro Nakamura, Barbara Dietel, Stephan Achenbach, Rainer Kollmar, Stefan Schwab, Kazuo Ushijima, Hideki Harada
Targeted temperature management (TTM), or therapeutic hypothermia, is one of the most potent neuroprotective approaches after ischemic and traumatic brain injuries. TTM has been applied clinically with various methods, but effective achievement and maintenance of the target temperature remain challenging. Furthermore, timing of cooling and target body and brain temperature to optimize effectiveness for neuroprotection and to minimize side effects are yet to be standardized. Focal brain cooling is a potential strategy to minimize adverse effects of systemic TTM...
September 8, 2018: Therapeutic Hypothermia and Temperature Management
K K Shahedah, C S Khoo, W Y Wan Nur Nafisah, C F Ng, I Noor Ashikin, M Y Mohd Naim, O Syazarina Sharis, Z Rozman, W Z Wan Asyraf
A 42-year-old female admitted with new-onset atrial fibrillation had a wake-up stroke on the high-dependency unit and the time last seen well (TLSW) was 6.5 h. She suffered left-sided body weakness and her National Institutes of Health Stroke Scale (NIHSS) score was 17. An emergency CT perfusion showed right M1 segment occlusion with more than 50% penumbra. She was given recombinant tissue plasminogen activator (r-tPA) at 9 h from TLSW. An immediate diagnostic angiogram with intention to treat, owing to the presence of large vessel occlusion, showed complete reperfusion after intravenous r-tPA...
September 2018: Journal of the Royal College of Physicians of Edinburgh
Defang Pang, Lu Wang, Jing Dong, Xiaoyin Lai, Qijuan Huang, Richard Milner, Longxuan Li
We have previously demonstrated that in response to cerebral ischemia (CI), the growth factor angiopoietin-1 (Ang1) and α5β1 integrin are both induced in cerebral vessels, which likely provide positive signals driving the endogenous angiogenic response and vascular protection after CI. However, the precise relationship between endothelial Ang1 and α5β1 integrin after CI remains poorly understood. Here, we investigated the effects of the interaction between the Ang1/Tie2 system and α5β1 integrin on brain endothelial cells (BECs) under cerebral ischemic conditions in vivo and in vitro...
September 5, 2018: Experimental & Molecular Medicine
Tian-Yu Tang, Yun Jiao, Ying Cui, Chu-Hui Zeng, Deng-Ling Zhao, Yi Zhang, Cheng-Yu Peng, Xin-Dao Yin, Pei-Yi Gao, Yun-Jun Yang, Sheng-Hong Ju, Gao-Jun Teng
The use of thrombolysis in acute ischemic stroke is restricted to a small proportion of patients because of the rigid 4·5-h window. With advanced imaging-based patient selection strategy, rescuing penumbra is critical to improving clinical outcomes. In this study, we included 155 acute ischemic stroke patients (84 patients in training dataset, age from 43 to 80, 59 males; 71 patients in validation dataset, age from 36 to 80, 45 males) who underwent MR scan within the first 9-h after onset, from 7 independent centers...
August 23, 2018: EBioMedicine
Michael G Hart, Rafael Romero-Garcia, Stephen J Price, John Suckling
BACKGROUND: Neurosurgical management of brain tumors has entered a paradigm of supramarginal resections that demands thorough understanding of peritumoral functional effects. Historically, the effects of tumors have been believed to be local, and long-range effects have not been considered. OBJECTIVE: To test the hypothesis that tumors affect the brain globally, producing long-range gradients in cortical function. METHODS: Resting-state functional magnetic resonance imaging (fMRI) data were acquired from 11 participants with glioblastoma and split into discovery and validation datasets in a single-center prospective cohort study...
August 22, 2018: Neurosurgery
Beng Zhang, Xiao-Hong Dai, Xue-Ping Yu, Wei Zou, Wei Teng, Xiao-Wei Sun, Wei-Wei Yu, Hao Liu, Hui Wang, Meng-Juan Sun, Meng Li
Baihui (DU20)-penetrating-Qubin (GB7) acupuncture can inhibit inflammatory reactions and activate signaling pathways related to proliferation after intracerebral hemorrhage. However, there is no research showing the relationship between this treatment and cell apoptosis. Rat models of intracerebral hemorrhage were established by injecting 60 μL of autologous blood into the right side of the caudate-putamen. Six hours later, the needle traveled subcutaneously from the Baihui acupoint to Qubin acupoint. The needle was alternately rotated (180 ± 10 turns/min) manually along clockwise and counter-clockwise directions...
September 2018: Neural Regeneration Research
Jan Borggrefe, Berit Glück, Volker Maus, Oezgur Onur, Nuran Abdullayev, Utako Barnikol, Christoph Kabbasch, Gereon Rudolf Fink, Anastasios Mpotsaris
BACKGROUND: Among patients with acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT), diabetic patients (DP) show a poorer outcome compared to non-diabetic patients (NDP). This study aims to provide a comprehensive analysis of factors associated with unfavorable outcome in DP receiving MT for stroke of the anterior circulation. METHODS: This study includes 317 out of 498 consecutive patients who received interventional treatment for AIS in the terminal internal carotid artery and/or middle cerebral artery, including 46 DP...
August 16, 2018: World Neurosurgery
D Alan Shewmon
This article clarifies some issues raised by Dr. Ariane Lewis in her recent "Current Opinion/Arguments" article on the case of Jahi McMath. Review of case materials. Jahi's case most likely represents an instance of global ischemic penumbra (GIP) mimicking brain death (BD), with intracranial blood flow too low to support neuronal function or to be detected by radionuclide scan but sufficient to prevent widespread necrosis. Her MRI scan 9 months after the ischemic insult showed gross preservation of cortical and internal structures, incompatible with there ever having been a period of completely absent blood flow...
August 15, 2018: Neurocritical Care
Naoko Funatsu, Mikito Hayakawa, Tetsuya Hashimoto, Hiroshi Yamagami, Tetsu Satow, Jun C Takahashi, Masatoshi Koga, Kazuyuki Nagatsuka, Hatsue Ishibashi-Ueda, Toru Iwama, Kazunori Toyoda
BACKGROUND AND PURPOSE: Vascular wall components (VWCs) are sometimes identified as collagen fibers in specimens retrieved by thrombectomy from acute stroke patients. However, their clinical significance and associated factors remain unclear. The purpose of this study was to clarify the factors associated with VWCs in retrieved thrombi. METHODS: Consecutive acute stroke patients treated endovascularly using the Penumbra aspiration catheter or stent retrievers (SRs) at our institute from November 2013 to April 2016 were retrospectively reviewed, and the retrieved thrombi were evaluated histopathologically...
August 10, 2018: Journal of Neurointerventional Surgery
Shinichi Goto, Takayuki Morikawa, Akiko Kubo, Keiyo Takubo, Keiichi Fukuda, Mayumi Kajimura, Makoto Suematsu
Carbon monoxide-generating heme oxygenase-2 is expressed in neurons and plays a crucial role for regulating hypoxic vasodilation through mechanisms unlocking carbon monoxide-dependent inhibition of H2 S-generating cystathionine β-synthase expressed in astrocytes. This study aims to examine whether heme oxygenase-2 plays a protective role in mice against stroke. Focal ischemia was induced by middle cerebral artery occlusion. Regional differences in metabolites among ipsilateral and contralateral hemispheres were analysed by quantitative imaging mass spectrometry equipped with an image-processing platform to optimize comparison of local metabolite contents among different animals...
July 2018: Journal of Clinical Biochemistry and Nutrition
Ting Zhang, Chang-Yan Li, Jing-Jing Jia, Jie-Shan Chi, Da Zhou, Jian-Zhou Li, Xiao-Ma Liu, Jun Zhang, Li Yi
Ischemia/reperfusion is known to greatly increase oxidative stress in the penumbra, which results in brain damage. Integrin αvβ3 is selectively up-regulated with ischemic injury to the brain and remains elevated throughout reperfusion. We determined whether or not a new compound biotinylated-LXW7-ceria nanoparticle (CeNP) (bLXW7-CeNP) plays a role in brain protection in the rat model of middle cerebral artery occlusion/reperfusion and shows better effects than CeNPs alone in improving the outcomes of focal oxidative stress and apoptosis more effectively...
February 2018: Current medical science
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