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S Pelletier

Publications and source records attributed to S Pelletier.

41 records · Page 3Linked to original sources
PubMedDate not supplied

Adenosine-induced inhibition of basal endothelin-1 production from guinea-pig tracheal epithelial cells: a mechanism involving the release of cAMP.

Guinea-pig tracheal epithelial cells, like other pulmonary cells in various species, have been reported to synthesize and release endothelins (ET). Their production is inducible by many agents and inhibited by ET-converting enzyme inhibitors, corticosteroids and beta agonists. Here, we studied the effect of adenosine on (1) the formation of adenosine 3', 5'-cyclic monophosphate (cAMP) and (2) concomitant effect on the basal release of ET from primary cultured tracheal epithelial cells isolated from guinea-pigs (GPTEpC). Adenosine (10(-7)-10(-3) M), the endogenous non-selective purinergic receptor agonist, induced the production of cAMP in a concentration-dependent manner (pD2=4.99+/-0.09). Concomitantly, adenosine decreased by a maximum of 39% ET-1-production over the same concentration range (with a 96% correlation). The inhibitory effect over ET-1-production was abolished by CGS15943 (10(-4) M), a non-selective A1/A2A receptor antagonist, and a xanthine amine congener (10(-4) M), a selective A1 receptor antagonist. Thus, these results suggest that adenosine attenuates the production of ET-1 from GPTEpC by stimulating the release of cAMP via the direct activation of adenosine receptors.

Adenosine↗
PubMedDate not supplied

Features of polymyositis and dermatomyositis in the elderly: a case-control study.

OBJECTIVE: Polymyositis (PM) and dermatomyositis (DM) are uncommon idiopathic inflammatory myopathies (IIM). Little is known about these diseases in the elderly. We attempted to define the characteristics of PM/DM in the elderly by a case-control study involving the retrospective review of medical files of PM/DM patients. METHODS: We drew from among 200 PM/DM patients being followed in our Internal Medicine Department 21 patients (14 F/7 M), aged > or = 65 years at the onset of myositis (17 PM/4 DM) (mean: 69.9 +/- 4.8 yrs.). They were compared with 21 (15 F/6 M) randomly selected younger patients with IIM: PM (14) and DM (7) (mean: 46.4 +/- 12.4 yrs). Clinical, biological, electrophysiological and pathologic features, treatment regimens and side-effects in the 2 groups were collected. RESULTS: Clinical features were similar for the 2 groups. Elderly patients tended to have a higher frequency of cancer (24% vs 9.5%, p = 0.06), particularly of rectal adenocarcinoma. The time from disease onset to diagnosis was significantly longer in older patients (26 +/- 37 months vs 9 +/- 15 months; p = 0.02), normal CK levels were more frequent (40% vs 5%; p = 0.02) and serum CK levels were lower than for the population as the whole (11.5 N vs 22 N, p < 0.03). Electromyography features were more frequently suggestive of a chronic form of the disease in elderly patients. Treatment regimens and short-term side-effects were similar for the 2 groups. CONCLUSION: PM and DM are often diagnosed late in the elderly. Biological data and electromyography features argue for a chronic form of the disease in this age group. Clinical and endoscopic rectal examinations should be carried out in elderly patients with PM/DM.

Adenocarcinoma↗
PubMedDate not supplied

[Exudative enteropathy in disseminated lupus erythematosus].

We present the case of a young woman with a protein-losing enteropathy occurring in the context of systemic lupus erythematosus. This rare complication has limited gastro-intestinal manifestations and must be systematically looked for when hypoalbuminemia occurs in the absence of a lupus nephritis. High dose corticosteroids therapy (> or = 1 mg/kg/day of prednisone) usually leads to recovery, and should be the first treatment attempted. If this treatment is ineffective, bolus injections of methylprednisolone (1 g/day for three days) may be recommended. Immunosuppressive therapy should be given only if the above treatments are ineffective, or in case of cortico-dependency.

Adult↗