Homocysteine and Raynaud's phenomenon: a review.

Raynaud's phenomenon, categorized as primary and secondary when occurring isolated or in association with an underlying disease, respectively, is a paroxysmal and recurrent acral ischemia resulting from an abnormal arterial vasospastic response to cold or emotional stress. The key issue in the pathogenesis of Raynaud's phenomenon is presumed to be a dysregulation in the mechanisms of vascular motility resulting in an imbalance between vasodilatation and vasoconstriction. Homocysteine, a non-protein forming sulphured amino acid proposed as an independent risk factor for atherothrombosis in the general population, clearly demonstrated to produce vascular damage through mechanisms also including endothelial injury and modifications in circulating mediators of vasomotion.

Arrhythmogenic effects of anti-Ro/SSA antibodies on the adult heart: more than expected?

The arrhythmogenicity of anti-Ro/SSA antibodies for the foetal heart and their crucial role in the development of congenital heart block is now well established, representing a paradigmatic model of passively acquired autoimmunity. Recently, intriguing data suggest that also the adult heart may represent a possible target of anti-Ro/SSA antibody-mediated autoimmune injury. The prolongation of the QTc interval, possibly resulting from a direct inhibitory interaction between the anti-Ro/SSA antibodies and the potassium current I(Kr) in the heart seems the abnormality more frequently observed in adults with anti-Ro/SSA-positive CTD.

Relationship between plasma nitric oxide concentration and insulin resistance in essential hypertension.

Background: Plasma nitric oxide (NOx) concentrations in patients with essential hypertension (EH) have been reported to be higher, lower, or no different than in normotensives. This study was initiated to determine whether these inconsistent findings were related to differences in insulin resistance.

Methods: Fasting plasma NOx and insulin concentrations were measured in 78 patients with EH and the relationship between these variables evaluated by regression analysis.