Publications by authors named "Chabrier P"

Botulinum neurotoxin B is a Food and Drug Administration-approved therapeutic toxin. However, it has lower binding affinity toward the human version of its major receptor, synaptotagmin II (h-Syt II), compared to mouse Syt II, because of a residue difference. Increasing the binding affinity to h-Syt II may improve botulinum neurotoxin B's therapeutic efficacy and reduce adverse effects.

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Background: In addition to inhibition of muscle and glandular hyperactivity, botulinum neurotoxin (BoNT) type A also interferes with pain processing. Previously, in a rat model of paclitaxel-induced polyneuropathy, abobotulinumtoxinA (aboBoNT-A) elicited analgesic effects not only in the injected paw, but also in the contralateral, non-injected paw.

Methods: Here, we assessed bilateral analgesic effects of unilateral aboBoNT-A in several chronic pain models in Sprague-Dawley rats.

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Histology is the gold standard to unveil microscopic brain structures and pathological alterations in humans and animal models of disease. However, due to tedious manual interventions, quantification of histopathological markers is classically performed on a few tissue sections, thus restricting measurements to limited portions of the brain. Recently developed 3D microscopic imaging techniques have allowed in-depth study of neuroanatomy.

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Intradetrusor injections of Botulinum toxin A-currently onabotulinumtoxinA-is registered as a second-line treatment to treat neurogenic detrusor overactivity (NDO). The common clinical practice is 30 × 1 mL injections in the detrusor; however, protocols remain variable and standardization is warranted. The effect of reducing the number of injection sites of Dysport(®) abobotulinumtoxinA (aboBoNTA) was assessed in the spinal cord-injured rat (SCI).

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Novel azole compounds were prepared which demonstrated potent hCB2 binding activities with antioxidant activity for a selected compound. These compounds show good selectivity over the hCB1 receptor and are full agonists at the hCB2 receptor.

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The development of dyskinesias following chronic L-DOPA replacement therapy remains a major problem in the long-term treatment of Parkinson's disease. This study aimed at evaluating the effect of IRC-082451 (base of BN82451), a novel multitargeting hybrid molecule, on L-DOPA-induced dyskinesias (LIDs) and hypolocomotor activity in a non-human primate model of PD. IRC-082451 displays multiple properties: it inhibits neuronal excitotoxicity (sodium channel blocker), oxidative stress (antioxidant) and neuroinflammation (cyclooxygenase inhibitor) and is endowed with mitochondrial protective properties.

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Background: Two botulinum toxins A have been evaluated for the treatment of refractory neurogenic detrusor overactivity (NDO) in humans: Dysport (abobotulinumtoxinA) and Botox (onabotulinumtoxinA). However, these two distinct commercialized products have different potency units and are not interchangeable.

Objective: Assessment of the dose response and determination of minimal effective dose (MED) for Dysport and Botox in spinal cord-injured (SCI) rats with NDO.

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The standardized extract of Ginkgo biloba EGb 761 has been used to reduce cognitive dysfunction. The present study was designed to evaluate the effect of postischemic oral treatment with EGb 761 in a model of vascular dementia in gerbils. Daily oral posttreatment with EGb 761 led to a significant recovery of spatial memory assessed by the object location test, inhibited the decrease in plasma SOD activity and protected the hippocampal CA1 neurons, even when administered after the insult.

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The development of L-dopa-induced dyskinesia (LID) remains a major problem in the long-term treatment of Parkinson's disease (PD). This study aimed to assess the effect of the multitargeting molecule BN82451 on LID and to measure striatal mRNA expression of several genes in a rat model of PD. Rats were administered two unilateral injections of 6-OHDA in the striatum.

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A number of experimental models of L-DOPA-induced dyskinesia have been proposed, but these models result in a low to medium rate of dyskinetic animals with mild to severe symptoms. The objective of this study was to combine a model of 6-OHDA-induced parkinsonism and of L-DOPA-induced dyskinesia in rats to establish a reliable preclinical model. Two stereotaxic injections of 6-OHDA were administered in the left striatum.

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In addition to inhibition of acetylcholine release in the neuromuscular junction botulinum toxin type A (BoNT-A) also inhibits the release of mediators involved in pain perception. We have investigated the effect of two types of BoNT-A on mechanical hyperalgesia in the rat models of carrageenan-induced hyperalgesia and of paclitaxel-induced peripheral neuropathy. A subplantar (s.

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Alzheimer's disease (AD) is a human neurodegenerative disease characterized by two key histopathological hallmarks : beta amyloid plaques and neurofibrillary tangles. No animal species naturally develops AD. Lesions induced by toxic substances which modify neurotransmission have been used in rodents but are not suitable models for AD.

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BIM-46187 (7-[2-amino-1-oxo-3-thio-propyl]-8-cyclohexylmethyl-2-phenyl-5,6,7,8-tetrahydro-imidazo-[1,2a]-pyrazine dimer, hydrochloride) is an inhibitor of the heterotrimeric G-protein complex signalling. Since many mediators of pain act through G-protein coupled receptors, the anti-hyperalgesic effects of BIM-46187 were assessed on experimental models of pain. In addition since opioids are widely used in pain management and act through specific G-protein-coupled receptors, the effects of BIM-46187 on the analgesic properties of morphine have also been investigated.

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BN82451 belongs to a new family of small molecules designated as multitargeting or hybrid molecules. BN82451 is orally active, has good central nervous system penetration, and elicits potent neuronal protection and antiinflammatory properties. Neuronal protection is due to Na+ channel blockade, antioxidant properties, and mitochondria-protecting activity, whereas inhibition of cyclooxygenases is mostly responsible for its antiinflammatory activity.

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Free radical and calcium buffering mechanisms are implicated in cochlear cell damage that has been induced by sound trauma. Thus in this study we evaluated the therapeutic effect of a novel dual inhibitor of calpains and of lipid peroxidation (BN 82270) on the permanent hearing and hair cell loss induced by sound trauma. Perfusion of BN 82270 into the scala tympani of the guinea pig cochlea prevented the formation of calpain-cleaved fodrin, translocation of cytochrome c, DNA fragmentation and hair cell degeneration caused by sound trauma.

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Motivation: Genome maps are fundamental to the study of an organism and essential in the process of genome sequencing which in turn provides the ultimate map of the genome. The increased number of genomes being sequenced offers new opportunities for the mapping of closely related organisms. We propose here an algorithmic formalization of a genome comparison approach to marker ordering.

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A series of 4-arylimidazole carbamates was synthesized and their binding affinities to the site-2 sodium (Na+) channel were determined. SAR studies led to the identification of compound 10, a potent Na+ channel blocker which was efficacious in pain models in vivo.

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Cell death is a common feature observed in neurodegenerative disorders, and is often associated with calpain activation and overproduction of reactive oxygen species (ROS). This study investigated the use of calpain inhibitors and antioxidants in combination to protect cells against necrosis. Maitotoxin (MTX), which induces a massive influx of calcium, was used to provoke neuronal cell death.

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A series of dipeptides with dual inhibitory activities on calpain and lipid peroxidation were prepared to target the intracellular calpain. This optimization program focused on the variations of the linker and the N-terminal amino acid of the peptidic core. Two compounds 6d-05 and 6d-08 exhibited potent intracellular calpain inhibition.

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Unlabelled: CAR(H)(T)A GENE: is an integrated genetic and radiation hybrid (RH) mapping tool which can deal with multiple populations, including mixtures of genetic and RH data. CAR(H)(T)A GENE: performs multipoint maximum likelihood estimations with accelerated expectation-maximization algorithms for some pedigrees and has sophisticated algorithms for marker ordering. Dedicated heuristics for framework mapping are also included.

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Minocycline has been reported to exert neuroprotection through inhibition of inflammatory processes and of mitochondrial cell death pathway. To further characterize the neuroprotective effect of minocycline, we determined its efficacy in different neuronal damage paradigms involving inflammation or mitochondrial dysfunction. In transient global ischaemia in gerbils, minocycline reduced hippocampal neuronal damage measured by peripheral type benzodiazepine binding sites density, a marker of microglial activation.

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A series of molecules with dual inhibitory activities on calpain and lipid peroxidation were synthesized. These hybrid compounds were built on the calpain pharmacophore 2-hydroxytetrahydrofuran linked to a set of antioxidants via a l-leucine linker. Compound 7, the most potent in cellular calpain and lipid peroxidation inhibitions, provided effective protection against glial cell death induced by maitotoxin.

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A series of 2-alkyl-4-arylimidazoles were prepared and their binding affinities to the site-2 sodium (Na+) channel were determined. SAR studies led to highly potent Na+ channel blockers.

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Novel phenolic thiazoles compounds were prepared which demonstrated potent antioxidant activity and potent in vivo neuroprotection in mitochondrial toxin models and also possess good oral bioavailability.

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There is substantial evidence that excitotoxicity and oxidative damage may contribute to Huntington's disease (HD) pathogenesis. We examined whether the novel anti-oxidant compound BN82451 exerts neuroprotective effects in the R6/2 transgenic mouse model of HD. Oral administration of BN82451 significantly improved motor performance and improved survival by 15%.

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