Ground Truth for Evaluation of Ischemic Stroke Hybrid Segmentation in a Rat Model of Temporary Middle Cerebral Artery Occlusion

In vivo rodent models of focal cerebral ischemia have been developed to investigate stroke therapy. Typically these models require rapid quantification of cerebral infarct volumes using vital stains with tetrazolium salts to delineate the extent of neuronal death. To avoid animal sacrifice, we sought a study with MR acquired volumetric rata data where surrogate of ground truth is obtained by repeated manual delineation by experts, and an automated hybrid segmentation is evaluated for accuracy. We propose a rating system for the expert delineations that captures intra- and inter-expert discrepancy. Our preliminary results show that surrogate ground truth derived from MR data is at least as good as the one derived from histologic stained slices. Hence animal sacrifice is not necessary to evaluate ischemic stroke automated segmentation in a rat model of temporary middle cerebral artery occlusion

Evaluation of Ischemic Stroke Hybrid Segmentation in a Rat Model of Temporary Middle Cerebral Artery Occlusion using Ground Truth from Histologic and MR data

A segmentation method that quantifies cerebral infarct using rat data with ischemic stroke is evaluated using ground truth from histologic and MR data. To demonstrate alternative approach to rapid quantification of cerebral infarct volumes using histologic stained slices that requires scarifying animal life, a study with MR acquire volumetric rat data is proposed where ground truth is obtained by manual delineations by experts and automated segmentation is assessed for accuracy. A framework for evaluation of segmentation is used that provides more detailed accuracy measurements than mere cerebral infarct volume. Our preliminary experiment shows that ground truth derived from MRI data is at least as good as the one obtained from the histologic slices for evaluating segmentation algorithms for accuracy. Therefore we can develop and evaluate automated segmentation methods for rapid quantification of stroke without the necessitating animal sacrifice

Role of Matrix Metalloproteinases and Therapeutic Benefits of Their Inhibition in Spinal Cord Injury

This review will focus on matrix metalloproteinases (MMPs) and their inhibitors in the context of spinal cord injury (SCI). MMPs have a specific cellular and temporal pattern of expression in the injured spinal cord. Here we consider their diverse functions in the acutely injured cord and during wound healing. Excessive activity of MMPs, and in particular gelatinase B (MMP-9), in the acutely injured cord contributes to disruption of the blood-spinal cord barrier, and the influx of leukocytes into the injured cord, as well as apoptosis. MMP-9 and MMP-2 regulate inflammation and neuropathic pain after peripheral nerve injury and may contribute to SCI-induced pain. Early pharmacologic inhibition of MMPs or the gelatinases (MMP-2 and MMP-9) results in an improvement in long-term neurological recovery and is associated with reduced glial scarring and neuropathic pain. During wound healing, gelatinase A (MMP-2) plays a critical role in limiting the formation of an inhibitory glial scar, and mice that are genetically deficient in this protease showed impaired recovery. Together, these findings illustrate complex, temporally distinct roles of MMPs in SCIs. As early gelatinase activity is detrimental, there is an emerging interest in developing gelatinase-targeted therapeutics that would be specifically tailored to the acute injured spinal cord. Thus, we focus this review on the development of selective gelatinase inhibitors

Zmiany w strukturach, uzbrojeniu i sposobach prowadzenia działań taktycznych na przełomie XX i XXI wieku w wybranych państwach NATO

Doświadczenia wojsk NATO w działaniach wojennych wskazały, że jednostki pancerne i zmechanizowane w operacjach pokojowych są mało efektywne i do takich zadań skuteczniejsze są pododdziały wyposażone w lekkie pojazdy, mogące być szybko przerzucone transportem powietrznym w dowolny rejon zagrożony konfliktem zbrojnym. Pojawiły się więc opinie o zmierzchu pododdziałów wyposażonych w broń ciężką. Szczególnie silne dążenie dla takiego kierunku zmian odnotowano w USA, gdzie po kilkuletniej dyskusji, w 1998 przystąpiono do restrukturyzacji ciężkich dywizji

Pododdziały zmechanizowane w działaniach powietrzno-lądowych

Analiza właściwości współczesnej walki, prognoz rozwoju środków walki i sposobów jej prowadzenia pozwala stwierdzić, że będzie rosła rola różnorodnego typu działań polegających na wykonywaniu uderzeń na przeciwnika z powietrza, powszechnym stanie się stosowanie taktycznych desantów powietrznych, rajdów śmigłowcowych i podobnych działań

GaAs and GaN based SAW chemical sensors: acoustic part design and technology

ISBN : 1-4244-0396-0International audienceIn this paper, we present the design considerations and the technology process of SAW (Surface Acoustic Wave) chemical sensors based either on GaAs or GaN structures. These sensors can be used for identifying environmental contaminants and chemical or biological agents in large applications scale; in this study, we aimed at the measurement of low concentrations of gaseous mercury. We describe the design of the acoustic part of the sensor including the structure for the generation and reception of the surface acoustic wave and the chemoselective coating made of gold. We show the technology process that achieves the device operating at the frequency of 250 MHz. Finally, we present some preliminary results obtained from the device