[Local registry of pacemakers implantations: proposals to decrease the infectious risk]. / Registre local des implantations de stimulateurs cardiaques: propositions permettant de diminuer le risque infectieux.

The complications of definitive cardiac stimulation must not be forgotten or sub estimate. The aim of our Registry is to compare the complications of the implantation of a pacemaker in the national and international literature. The assessment of our professional practices has been achieved. We suggest improved procedures. The late complications are not exactly known.

Aspirin and sodium salicylate inhibit endothelin ETA receptors by an allosteric type of mechanism.

Aspirin is a commonly used drug with a wide pharmacological spectrum including antiplatelet, anti-inflammatory, and neuroprotective actions. This study shows that aspirin and sodium salicylate, its major blood metabolite, reverse contractile actions of endothelin-1 (ET-1) in isolated rat aorta and human mammary arteries. They also prevent the intracellular Ca(2+) mobilizing action of ET-1 in cultured endothelial cells but not those of neuromedin B or UTP. Inhibition of the actions of ET-1 by salicylates is apparently competitive. Salicylates inhibit (125)I-ET-1 binding to recombinant rat ETA receptors. Salicylic acid promotes dissociation of (125)I-ET-1 ETA receptor complexes both in the absence and the presence of unlabeled ET-1. It has no influence on the rate of association of (125)I-ET-1 to ETA receptors. Salicylates do not promote dissociation of (125)I-ET-1 ETB receptor complexes. Salicylates potentiate relaxing actions of receptor antagonists such as bosentan. It is concluded that salicylates are allosteric inhibitors of ETA receptors. The results also suggest that: 1) irreversible ET-1 binding probably limits actions of receptor antagonists in vivo, and 2) an association of salicylates and ETA receptor antagonists should be used to evaluate the physiopathological role of ET-1 and may be of therapeutic interest in the treatment of ischemic heart disease.

[Rapid decrease of serum endothelin-1 levels after treatment with ACE inhibitors in chronic cardiac failure]. / Diminution rapide des taux sériques d'endothéline-1 après traitement par inhibiteur de l'enzyme de conversion dans l'insuffisance cardiaque chronique.

Circulating endothelin-1, a very strong peptide vasoconstrictor first discovered in 1988, is raised in cardiac failure. This increase contributes to the deleterious effects of cardiac failure. Although specific anti-endothelin drugs are under development in this condition, the effects of more commonly used drugs on circulating endothelin-1 levels are not well known. The aim of this study was to evaluate the effects of ACE inhibitor therapy on plasma endothelin-1 levels in cardiac failure. The plasma endothelin-1 levels were measured in 24 patients (stages III and IV of the NYHA classification), before and after treatment with angiotensin converting enzyme inhibitor (Captopril: test doses, then 75 mg/day). A control group of 10 paired patients was used to shake off the effects of bed rest and hospital salt-free diet. The initial endothelin-1 levels were high but equivalent in the control and study groups: 9.13 +/- 1.87 fmol/mL vs 8.98 +/- 1.92 fmol/mL. Plasma endothelin-1 decreased significantly in the study group 72 hours after beginning ACE inhibitor therapy (7.44 +/- 1.95, p < 0.02) but remained higher than normal (p < 0.01), whereas the values in the control group remained the same. This study demonstrates a decreases in plasma endothelin-1 levels 72 hours after onset of ACE inhibitor therapy in patients with stable severe cardiac failure. This results, already suggested by many experimental studies and certain ancillary clinical trials, could explain some of the beneficial effects of ACE inhibitors in this condition.

Evidence for receptor bound endothelin in renal but not in cardiac tissues from normal rats.

OBJECTIVES: The stoichiometric binding model (Frelin C, Guedin D. Cardiovasc Res 1994;28:1613-1622) implies that most endothelin in tissues is bound onto receptors rather than in a free state. The objective of this study was to assay receptor bound endothelins in normal rat tissues. METHODS: We first defined acidic conditions that promoted a mild and reversible denaturation of ETA and ETB receptors and that allowed dissociation of bound [125I]endothelin-1. The action of an acid wash on [125I]endothelin-1 binding to cell or tissue homogenates was then investigated. RESULTS: Acid washing of homogenates prepared from rat brain capillary endothelial cells that express prepro endothelin-1 mRNAs unmasked receptor sites. Acid washing of cardiac, lung, brain or liver homogenates did not increase [125I]endothelin-1 binding. An acid wash of kidney homogenates increased 2.2 fold [125I]endothelin-1 binding. Experiments using BQ-123 further indicated that the acid treatment of renal homogenates mainly unmasked ETA receptors. Masked renal ET receptors were mainly localized in the medulla. Treatment of rats with phosphoramidon decreased the density of masked ET receptors in kidney homogenates. CONCLUSION: As much as 50% of endothelin receptors in renal tissues are masked by endogenous endothelins. Most cardiac receptors are free of bound endothelins. These suggest that endothelins act as local rather than systemic mediators.

[Pulmonary hypertension caused by talcoma in a couple of drug addicts]. / Hypertension artérielle pulmonaire sur talcome chez un couple de toxicomanes.

The authors report a case of severe pulmonary hypertension (PHT) in a couple of HIV seropositive heroin addicts. The parallel clinical course in these two patients with only mild immunodeficiency and the fact that they both had the same supplier were in favour of PHT secondary to talcoma. In the light of these cases, one wonders whether, as suggested by certain epidemiological studies currently underway, drug addiction should be considered to be a cause of PHT in its own right. According to the authors, this approach would underestimate the incidence of this disease in this particular population and would therefore bias the epidemiological data.

Mycobacterium avium intracellulare suppurative thyroiditis in a patient with Hashimoto's thyroiditis.

A case of suppurative thyroiditis occurring in a 72-year-old woman is reported. The clinical history of this woman, treated by tianeptine for mild exogenous affective disorder and by conventional insulin therapy for long-standing insulin-dependent diabetes, was remarkable for the pseudotumoral signs which led to the simultaneous diagnosis of hypothyroidism due to Hashimoto's thyroiditis and of mycobacterium avium intracellulare suppurative thyroiditis. To our knowledge, this is the second reported case of mycobacterium avium intracellulare thyroiditis. This case is also exemplary, given its occurrence in the absence of severe immunodepression, setting apart the mild impact on the immune system of affective disorder and of long duration's insulin-dependent diabetes.