1.Development of neural correlates of linear motion in the rat vestibular nucleus.
Chun-Wai MA ; Chun-Hong LAI ; Lei HAN ; Daisy Kwok-Yan SHUM ; Ying-Shing CHAN
Acta Physiologica Sinica 2014;66(1):37-46
The capability of the central vestibular system in utilizing cues arising from the inner ear determines the ability of animals to acquire the sense of head orientations in the three-dimensional space and to shape postural movements. During development, neurons in the vestibular nucleus (VN) show significant changes in their electrophysiological properties. An age-dependent enhancement of membrane excitability is accompanied by a progressive increase in firing rate and discharge regularity. The coding of horizontal and vertical linear motions also exhibits developmental refinement in VN neurons. Further, modification of cell surface receptors, such as glutamate receptors, of developing VN neurons are well-orchestrated in the course of maturation, thereby regulating synaptic efficacy and spatial coding capacity of these neurons in local circuits. Taken together, these characteristic features of VN neurons contribute to developmental establishment of space-centered coordinates within the brain.
Animals
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Ear, Inner
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physiology
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Electrophysiological Phenomena
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Movement
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Neurons
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physiology
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Rats
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Receptors, Cell Surface
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physiology
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Vestibular Nuclei
;
physiology
2.Prognostic Tools for Early Mortality in Hemorrhagic Stroke: Systematic Review and Meta-Analysis.
Katharina MATTISHENT ; Chun Shing KWOK ; Liban ASHKIR ; Kelum PELPOLA ; Phyo Kyaw MYINT ; Yoon Kong LOKE
Journal of Clinical Neurology 2015;11(4):339-348
BACKGROUND AND PURPOSE: Several risk scores have been developed to predict mortality in intracerebral hemorrhage (ICH). We aimed to systematically determine the performance of published prognostic tools. METHODS: We searched MEDLINE and EMBASE for prognostic models (published between 2004 and April 2014) used in predicting early mortality (<6 months) after ICH. We evaluated the discrimination performance of the tools through a random-effects meta-analysis of the area under the receiver operating characteristic curve (AUC) or c-statistic. We evaluated the following components of the study validity: study design, collection of prognostic variables, treatment pathways, and missing data. RESULTS: We identified 11 articles (involving 41,555 patients) reporting on the accuracy of 12 different tools for predicting mortality in ICH. Most studies were either retrospective or post-hoc analyses of prospectively collected data; all but one produced validation data. The Hemphill-ICH score had the largest number of validation cohorts (9 studies involving 3,819 patients) within our systematic review and showed good performance in 4 countries, with a pooled AUC of 0.80 [95% confidence interval (CI)=0.77-0.85]. We identified several modified versions of the Hemphill-ICH score, with the ICH-Grading Scale (GS) score appearing to be the most promising variant, with a pooled AUC across four studies of 0.87 (95% CI=0.84-0.90). Subgroup testing found statistically significant differences between the AUCs obtained in studies involving Hemphill-ICH and ICH-GS scores (p=0.01). CONCLUSIONS: Our meta-analysis evaluated the performance of 12 ICH prognostic tools and found greater supporting evidence for 2 models (Hemphill-ICH and ICH-GS), with generally good performance overall.
Area Under Curve
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Cerebral Hemorrhage
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Cohort Studies
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Discrimination (Psychology)
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Mortality*
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Prospective Studies
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Retrospective Studies
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ROC Curve
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Stroke*
3.Blood flow in intracranial aneurysms treated with Pipeline embolization devices: computational simulation and verification with Doppler ultrasonography on phantom models.
Anderson Chun On TSANG ; Simon Sui Man LAI ; Wai Choi CHUNG ; Abraham Yik Sau TANG ; Gilberto Ka Kit LEUNG ; Alexander Kai Kei POON ; Alfred Cheuk Hang YU ; Kwok Wing CHOW
Ultrasonography 2015;34(2):98-108
PURPOSE: The aim of this study was to validate a computational fluid dynamics (CFD) simulation of flow-diverter treatment through Doppler ultrasonography measurements in patient-specific models of intracranial bifurcation and side-wall aneurysms. METHODS: Computational and physical models of patient-specific bifurcation and sidewall aneurysms were constructed from computed tomography angiography with use of stereolithography, a three-dimensional printing technology. Flow dynamics parameters before and after flow-diverter treatment were measured with pulse-wave and color Doppler ultrasonography, and then compared with CFD simulations. RESULTS: CFD simulations showed drastic flow reduction after flow-diverter treatment in both aneurysms. The mean volume flow rate decreased by 90% and 85% for the bifurcation aneurysm and the side-wall aneurysm, respectively. Velocity contour plots from computer simulations before and after flow diversion closely resembled the patterns obtained by color Doppler ultrasonography. CONCLUSION: The CFD estimation of flow reduction in aneurysms treated with a flow-diverting stent was verified by Doppler ultrasonography in patient-specific phantom models of bifurcation and side-wall aneurysms. The combination of CFD and ultrasonography may constitute a feasible and reliable technique in studying the treatment of intracranial aneurysms with flow-diverting stents.
Aneurysm
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Angiography
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Computer Simulation
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Endovascular Procedures
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Hydrodynamics
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Intracranial Aneurysm*
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Stents
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Ultrasonography
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Ultrasonography, Doppler*
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Ultrasonography, Doppler, Color
4.Targeting papain-like protease for broad-spectrum coronavirus inhibition.
Shuofeng YUAN ; Xiaopan GAO ; Kaiming TANG ; Jian-Piao CAI ; Menglong HU ; Peng LUO ; Lei WEN ; Zi-Wei YE ; Cuiting LUO ; Jessica Oi-Ling TSANG ; Chris Chun-Yiu CHAN ; Yaoqiang HUANG ; Jianli CAO ; Ronghui LIANG ; Zhenzhi QIN ; Bo QIN ; Feifei YIN ; Hin CHU ; Dong-Yan JIN ; Ren SUN ; Jasper Fuk-Woo CHAN ; Sheng CUI ; Kwok-Yung YUEN
Protein & Cell 2022;13(12):940-953
The emergence of SARS-CoV-2 variants of concern and repeated outbreaks of coronavirus epidemics in the past two decades emphasize the need for next-generation pan-coronaviral therapeutics. Drugging the multi-functional papain-like protease (PLpro) domain of the viral nsp3 holds promise. However, none of the known coronavirus PLpro inhibitors has been shown to be in vivo active. Herein, we screened a structurally diverse library of 50,080 compounds for potential coronavirus PLpro inhibitors and identified a noncovalent lead inhibitor F0213 that has broad-spectrum anti-coronaviral activity, including against the Sarbecoviruses (SARS-CoV-1 and SARS-CoV-2), Merbecovirus (MERS-CoV), as well as the Alphacoronavirus (hCoV-229E and hCoV-OC43). Importantly, F0213 confers protection in both SARS-CoV-2-infected hamsters and MERS-CoV-infected human DPP4-knockin mice. F0213 possesses a dual therapeutic functionality that suppresses coronavirus replication via blocking viral polyprotein cleavage, as well as promoting antiviral immunity by antagonizing the PLpro deubiquitinase activity. Despite the significant difference of substrate recognition, mode of inhibition studies suggest that F0213 is a competitive inhibitor against SARS2-PLpro via binding with the 157K amino acid residue, whereas an allosteric inhibitor of MERS-PLpro interacting with its 271E position. Our proof-of-concept findings demonstrated that PLpro is a valid target for the development of broad-spectrum anti-coronavirus agents. The orally administered F0213 may serve as a promising lead compound for combating the ongoing COVID-19 pandemic and future coronavirus outbreaks.
Animals
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Coronavirus Papain-Like Proteases/antagonists & inhibitors*
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Cricetinae
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Humans
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Mice
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Pandemics
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SARS-CoV-2/enzymology*
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COVID-19 Drug Treatment