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Biomedical subjects

Dorothée Chabas

Publications and source records attributed to Dorothée Chabas.

2 recordsLinked to original sources

Pediatric multiple sclerosis.

Multiple sclerosis (MS) occurs at all ages of the pediatric population. Childhood MS may represent up to 10% of all MS cases. Establishing the diagnosis of MS in a child is complicated by the limited diagnostic criteria and the possibility of significant clinical and magnetic resonance imaging (MRI) overlap with acute disseminated encephalomyelitis and other pediatric diseases. Although the clinical profile of MS appears similar to that seen in adults, several features may differ and specific issues arise in children. Sex ratios are different between young children with MS and adolescents--implicating a role for sex hormones in disease pathogenesis and/or modification of disease expression. Younger patients with MS are more likely to have seizures, brainstem, and cerebellar symptoms than adults. Children with MS may have fewer T2 hyperintense areas on MRI scans, therefore not meeting MRI criteria established for adults. It is possible that the pediatric MS course is more indolent than in adult patients but the disease may lead to significant disability at a younger age, e.g., while patients are students, young professionals, or want to start a family. There has been no controlled clinical trial in children with disease modifying therapies approved for adult MS due to the limited number of patients under the age of 18 years compared with the adult contingent. As a result, children are receiving adult therapies in an arbitrary manner and our understanding of pediatric treatment effect and tolerability is limited. Available data on tolerability of approved drugs for adults is reviewed.

Child↗

[Osteopontin, a multi-faceted molecule].

Osteopontin (OPN) was initially isolated from bovine bone cortex, as a complex syalilated phospho-glyco-protein of around 60 kDa, with many postranslational modifications. It has been long considered a structural bone protein linking bone cells to the bone extracellular matrix (osteo : bone, pontin : bridge). It has been cloned for the first time in 1986. Since then, it was established that it is part of a protein family called SIBLINGs, which genes share common expression in bone and tooth, and encode among others a RGD motif. OPN is an intracellular as well as secreted protein, which binds to multiple organic or mineral ligands, like the integrin receptor alphaVbeta3, CD44, factor H and hydroxyapatite, depending on its final configuration (phosphorylation state). Pleiotropic functions of osteopontin have been demonstrated, and the osteopontin knock out phenotype in mice gave some new insight on the implication of the molecule in vivo. Osteopontin inhibits mineralization in bone and urine. Besides, it is a strong chemoattractive and proinflammatory molecule, implicated in tumors, like breast or prostate cancers, and in the defense against various infectious agents like tuberculosis, listeria or herpes. More recently, its key implication in TH1 mediated autoimmune diseases like multiple sclerosis and its animal model experimental autoimmune encephalomyelitis has been demonstrated. Osteopontin is a valuable therapeutic target in the animal model, and a biological tool correlating with clinical disease activity in humans. Structural, functional and pathological aspects of osteopontin are reviewed, as well as the osteopontin deficient phenotype in mouse.

Animals↗