53 research outputs found

    Concussion, Microvascular Injury, and Early Tauopathy in Young Athletes After Impact Head Injury and an Impact Concussion Mouse Model

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    The mechanisms underpinning concussion, traumatic brain injury, and chronic traumatic encephalopathy, and the relationships between these disorders, are poorly understood. We examined post-mortem brains from teenage athletes in the acute-subacute period after mild closed-head impact injury and found astrocytosis, myelinated axonopathy, microvascular injury, perivascular neuroinflammation, and phosphorylated tau protein pathology. To investigate causal mechanisms, we developed a mouse model of lateral closed-head impact injury that uses momentum transfer to induce traumatic head acceleration. Unanaesthetized mice subjected to unilateral impact exhibited abrupt onset, transient course, and rapid resolution of a concussion-like syndrome characterized by altered arousal, contralateral hemiparesis, truncal ataxia, locomotor and balance impairments, and neurobehavioural deficits. Experimental impact injury was associated with axonopathy, blood-brain barrier disruption, astrocytosis, microgliosis (with activation of triggering receptor expressed on myeloid cells, TREM2), monocyte infiltration, and phosphorylated tauopathy in cerebral cortex ipsilateral and subjacent to impact. Phosphorylated tauopathy was detected in ipsilateral axons by 24 h, bilateral axons and soma by 2 weeks, and distant cortex bilaterally at 5.5 months post-injury. Impact pathologies co-localized with serum albumin extravasation in the brain that was diagnostically detectable in living mice by dynamic contrast-enhanced MRI. These pathologies were also accompanied by early, persistent, and bilateral impairment in axonal conduction velocity in the hippocampus and defective long-term potentiation of synaptic neurotransmission in the medial prefrontal cortex, brain regions distant from acute brain injury. Surprisingly, acute neurobehavioural deficits at the time of injury did not correlate with blood-brain barrier disruption, microgliosis, neuroinflammation, phosphorylated tauopathy, or electrophysiological dysfunction. Furthermore, concussion-like deficits were observed after impact injury, but not after blast exposure under experimental conditions matched for head kinematics. Computational modelling showed that impact injury generated focal point loading on the head and seven-fold greater peak shear stress in the brain compared to blast exposure. Moreover, intracerebral shear stress peaked before onset of gross head motion. By comparison, blast induced distributed force loading on the head and diffuse, lower magnitude shear stress in the brain. We conclude that force loading mechanics at the time of injury shape acute neurobehavioural responses, structural brain damage, and neuropathological sequelae triggered by neurotrauma. These results indicate that closed-head impact injuries, independent of concussive signs, can induce traumatic brain injury as well as early pathologies and functional sequelae associated with chronic traumatic encephalopathy. These results also shed light on the origins of concussion and relationship to traumatic brain injury and its aftermath.awx350media15713427811001

    Epidemiologic, pathogenic and molecular analysis of recent encephalomyocarditis outbreaks in Belgium.

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    &lt;p&gt;In 1991 EMCV was isolated for the first time in Belgium from the offspring of a sow with reproductive failure. From August 1995 until December 1996, EMCV was diagnosed in 154 Belgian pig holdings in association with myocardial failure and sudden death in fatteners and suckling piglets or with reproductive failure in sows. To clarify some epidemiological aspects 3 EMCV isolates characteristic for the different clinical pictures and outbreaks were studied. Field observations and animal experiments indicated that the pathogenicity induced by each isolate is specific for one age category and that the spread of the virus is limited. The presented data also suggest that rodents may play a role in the transmission of EMCV but that pig-to-pig transmission is at least as important. Molecular analysis of two separate regions on the genomes of the respective EMCV isolates showed that the 1995-96 EMCV epizootic in Belgium was due to a new virus introduction. Furthermore, the VP1 coding gene is proposed as a marker of virulence.&lt;/p&gt;</p

    : J Gynecol Obstet Hum Reprod

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    International audienceOBJECTIVE: In France, termination of pregnancy (TOP) for medical reasons is legal, regardless of the term, after authorisation by a Multidisciplinary Centre for Prenatal Diagnosis (MCPD). This study analyses the elements supporting the TOP decision-making process faced with a foetal pathology. STUDY DESIGN: Medical records of one MCPD were analysed for the period 2013 and 2014 and semi-structured interviews with MCPD members were conducted. RESULTS: Out of 265 files concerning foetal indications, all but one resulted in a decision for TOP. The main indications in number for TOP were malformations and chromosomal abnormalities. For indications such as trisomy 21, authorisations are generally given without discussion. Our results underline the importance that professionals attach to the collegiality of decisions, particularly in situations of uncertainty. CONCLUSION: This study provides information about the activity of MCPDs within the field of prenatal diagnosis and shows the importance of these structures in supporting women and couples whilst respecting their autonomy. At present, the role of the MCPD is in the process of evolving and could become an information and advisory board for women, based on collegial expertise to guide their decision-making

    J Gynecol Obstet Hum Reprod

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    OBJECTIVE: In France, termination of pregnancy (TOP) for medical reasons is legal, regardless of the term, after authorisation by a Multidisciplinary Centre for Prenatal Diagnosis (MCPD). This study analyses the elements supporting the TOP decision-making process faced with a foetal pathology. STUDY DESIGN: Medical records of one MCPD were analysed for the period 2013 and 2014 and semi-structured interviews with MCPD members were conducted. RESULTS: Out of 265 files concerning foetal indications, all but one resulted in a decision for TOP. The main indications in number for TOP were malformations and chromosomal abnormalities. For indications such as trisomy 21, authorisations are generally given without discussion. Our results underline the importance that professionals attach to the collegiality of decisions, particularly in situations of uncertainty. CONCLUSION: This study provides information about the activity of MCPDs within the field of prenatal diagnosis and shows the importance of these structures in supporting women and couples whilst respecting their autonomy. At present, the role of the MCPD is in the process of evolving and could become an information and advisory board for women, based on collegial expertise to guide their decision-making

    Cobalt(II)-dibenzotetraaza[14]annulene complex electropolymerization for electrode modification

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    International audienceCobalt complexes of dibenzotetraaza[14]annulene (CoTAA), 5,7,12,14-tetramethyldibenzotetraaza[14]annulene (CoTMTAA), and dichlorodibenzotetraaza[14]annulene (CoTAACl2) have been studied by voltammetry in benzonitrile (BN). Their electropolymerization from solutions in BN was performed by oxidation at carbon and platinum electrodes. The Co(II)/Co(I) and Co(III)/Co(II) redox systems are clearly apparent on the voltammograms, as well as the electroactivity of the conducting polymer, when the electrode is in contact with the non-aqueous solvent. More surprising is the fact that the modification of electrode surfaces is also possible from the oxidation of aqueous acidic solutions of CoTAA and CoTAACl2 (2.25 M H2SO4). In contact with an acidic aqueous medium (0.5 M H2SO4), the Co(III)/Co(II) system of poly(CoTAA) is fully reversible. The polymer thus obtained can grow as a remarkably thick, dense and conducting phase. © 2000 Elsevier Science B.V
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