[Contribution of 64-slice cardiac tomodensitometry for non-invasive diagnosis of acute myocarditis].

Background: The association of acute chest pain, elevation of the cardiac enzymes and biological markers of inflammation suggests the diagnosis of myocarditis. The aim of the present study is to evaluate the diagnostic value of the multidetectors cardiac tomodensitometry (MDCT) for the confirmation of this diagnosis.

Patients And Methods: From October 2005 to April 2011, 39 patients aged 15.

[Use of 64-slice tomodensitometry after cardiac arrest].

Acute coronary occlusion is the leading cause of out-of-hospital cardiac arrest, so patients are usually referred for immediate coronary angiography and angioplasty. We report here the observation of such a patient who previously underwent a coronary artery bypass intervention and who had a difficult arterial access. Moreover, the nature of the grafts was unknown (saphenous and/or mammary arteries).

Agonist trapped in ATP-binding sites of the P2X2 receptor.

ATP-gated P2X receptors are trimeric ion channels, as recently confirmed by X-ray crystallography. However, the structure was solved without ATP and even though extracellular intersubunit cavities surrounded by conserved amino acid residues previously shown to be important for ATP function were proposed to house ATP, the localization of the ATP sites remains elusive. Here we localize the ATP-binding sites by creating, through a proximity-dependent "tethering" reaction, covalent bonds between a synthesized ATP-derived thiol-reactive P2X2 agonist (NCS-ATP) and single cysteine mutants engineered in the putative binding cavities of the P2X2 receptor.

A putative extracellular salt bridge at the subunit interface contributes to the ion channel function of the ATP-gated P2X2 receptor.

The recent crystal structure of the ATP-gated P2X4 receptor revealed a static view of its architecture, but the molecular mechanisms underlying the P2X channels activation are still unknown. By using a P2X2 model based on the x-ray structure, we sought salt bridges formed between charged residues located in a region that directly connects putative ATP-binding sites to the ion channel. To reveal their significance for ion channel activation, we made systematic charge exchanges and measured the effects on ATP sensitivity.