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G Sémana

Publications and source records attributed to G Sémana.

5 recordsLinked to original sources
PubMed2003

Intercellular adhesion molecule-1: a protective haplotype against multiple sclerosis.

Intercellular adhesion molecule-1 (ICAM-1) and its receptors are adhesion molecules that play a key role in the transmigration of inflammatory cells through the blood-brain barrier, one of the earliest events in multiple sclerosis (MS), which leads to demyelination in the central nervous system. To investigate the role of genes encoding ICAM-1 and its receptors, we used a strategy of genetic linkage and association in 439 case-parent MS families of French origin, well characterized according to HLA status and severity. We demonstrate that the genes encoding ICAM-1 receptors do not influence MS susceptibility or severity. ICAM-1 had a modest, but significant effect on MS genetic susceptibility, independent of HLA and disease severity. We observed a rare, and an as yet unreported, ICAM-1 gene haplotype defined by amino acids K469 and R241 that was never transmitted to patients suggesting a protective effect against MS in our population.

Age of Onset↗
PubMed1999

An immunomodulation strategy targeted towards immunocompetent cells or cytokines in inflammatory bowel diseases (IBD).

Many immunological abnormalities have been described in inflammatory bowel diseases (IBD). Even though, no clear cut primary defects have yet been described, some therapeutic trials have targeted either immunocompetent cells or overproduction of cytokines. Preliminary results have shown that antisense oligonucleotides (anti-ICAM), anti-cytokine antibodies (anti-TNF) or recombinant human cytokines (IL-10 or IL-11) are effective in some patients with Crohn's disease refractory to steroids. However, these data need to be confirmed and the potential side effects of these treatments must be further considered. These drugs need to be more precisely defined in particular compared to corticotherapy. Finally, data from immunomodulation strategies should help us understand the aetiology of abnormal immune responses in Crohn's disease (CD) and ulcerative colitis (UC).

Antibodies↗
PubMedDate not supplied

Quantitation of chemokines (MDC, TARC) expression in mucosa from Crohn's disease and ulcerative colitis.

Chemokines and their receptors are involved in the migration of different mononuclear cells. Among them macrophages-derived chemokines (MDC) and thymus-and activation regulated chemokine (TARC) belong to a new cluster of genes involve in Th2 lymphocytes homing. Cytokines appear to play a significant role in pathogenesis of inflammatory bowel diseases with an excessive Th1 response in chronic lesions of Crohn's disease (CD) and a Th2 pattern in both earlier mucosal CD lesions and in mucosa of ulcerative colitis (UC). Here we demonstrate that RNAm coding for MDC and TARC are expressed in mucosa from CD and UC patients. Using real-time fluorescent RT-PCR, MDC and TARC mRNA were increased in CD inflamed mucosa. Moreover MDC and TARC transcripts were increased in inflamed CD specimen compared to non-involved CD mucosa. These differences both discriminate CD from UC patients. Additionally, MDC protein was produced in isolated mononuclear cells from peripheral blood (PBMC) or mucosa (LPMC) from UC and CD patients: spontaneously, MDC production from PBMC was increased in CD compared to UC patients. MDC production from CD PBMC was also higher than that found in healthy controls. Together, these data indicate that MDC should be involved in the lymphocytes homing in mucosa from CD patients.

Adolescent↗