Mistyping of angiotensinogen M235T alleles.

Conflicting results are to be found in the literature on the relationship between the M235T polymorphism of the angiotensinogen (AGT) gene and hypertension. The controversy may be due to insufficient numbers of subjects, the variability of the inclusion criteria and the different genotype analysis methods used. We have experienced that the most frequently used, original polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method involves significant uncertainties when the TT genotype is determined, independently of the restriction digestion. To make the determination more accurate, we improved the PCR by designing a new antisense primer containing only one mismatch instead of the two in the original protocol and also by adding DMSO to the PCR reaction mixture. The original and our improved methods were compared by using DNA from 123 patients: parallel determinations resulted in values of 33 MM, 90 MT and 0 TT with the original method and of 33 MM, 56 MT and 34 TT with the improved RFLP protocol. In summary, a plausible explanation for some of the conflicting data published on AGT M235T polymorphism may be that inaccuracies arose during the determination of the genotype.     

How to diagnose diastolic heart failure: a consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the Heart Failure and Echocardiography Associations of the European Society of Cardiology.

Diastolic heart failure (DHF) currently accounts for more than 50% of all heart failure patients. DHF is also referred to as heart failure with normal left ventricular (LV) ejection fraction (HFNEF) to indicate that HFNEF could be a precursor of heart failure with reduced LVEF. Because of improved cardiac imaging and because of widespread clinical use of plasma levels of natriuretic peptides, diagnostic criteria for HFNEF needed to be updated. The diagnosis of HFNEF requires the following conditions to be satisfied: (i) signs or symptoms of heart failure; (ii) normal or mildly abnormal systolic LV function; (iii) evidence of diastolic LV dysfunction. Normal or mildly abnormal systolic LV function implies both an LVEF > 50% and an LV end-diastolic volume index (LVEDVI) <97 mL/m(2). Diagnostic evidence of diastolic LV dysfunction can be obtained invasively (LV end-diastolic pressure >16 mmHg or mean pulmonary capillary wedge pressure >12 mmHg) or non-invasively by tissue Doppler (TD) (E/E' > 15). If TD yields an E/E' ratio suggestive of diastolic LV dysfunction (15 > E/E' > 8), additional non-invasive investigations are required for diagnostic evidence of diastolic LV dysfunction. These can consist of blood flow Doppler of mitral valve or pulmonary veins, echo measures of LV mass index or left atrial volume index, electrocardiographic evidence of atrial fibrillation, or plasma levels of natriuretic peptides. If plasma levels of natriuretic peptides are elevated, diagnostic evidence of diastolic LV dysfunction also requires additional non-invasive investigations such as TD, blood flow Doppler of mitral valve or pulmonary veins, echo measures of LV mass index or left atrial volume index, or electrocardiographic evidence of atrial fibrillation. A similar strategy with focus on a high negative predictive value of successive investigations is proposed for the exclusion of HFNEF in patients with breathlessness and no signs of congestion. The updated strategies for the diagnosis and exclusion of HFNEF are useful not only for individual patient management but also for patient recruitment in future clinical trials exploring therapies for HFNEF.     

Effect of alpha adrenergic agents and phorbol esters on phosphorylation of sarcolemmal proteins in beating guinea pig hearts

STUDY OBJECTIVE--The aim was to determine whether activation of protein kinase C by alpha adrenergic agonists or phorbol esters would be associated with increased phosphorylation of the 15 kDa sarcolemmal protein in guinea pig hearts. DESIGN--Intact, beating guinea pig hearts were perfused with modified Krebs-Henseleit buffer containing [32P]Pi and freeze clamped in a control condition or at the peak of the inotropic response to noradrenaline. Membrane vesicles enriched in sarcolemma were isolated and then subjected to SDS polyacrylamide gel electrophoresis and autoradiography. Phosphorylated proteins were identified and 32P incorporation was quantitated. In some cases, hearts were perfused with phorbol 12-myristate, 13-acetate, or dioctanoyl-glycerol, which are known to be potent activators of protein kinase C. EXPERIMENTAL PREPARATIONS--Whole hearts from 55 anaesthetised guinea pigs weighing 500-600 g were used. MEASUREMENTS AND MAIN RESULTS--Perfusion of guinea pig hearts with noradrenaline resulted in increases in contractility and tissue inositol 1,4,5-triphosphate levels, but there were no increases in the phosphorylation of the 15 kDa sarcolemmal protein observed. Furthermore, perfusion with phorbol 12-myristate, 13-acetate, or dioctanoylglycerol failed to stimulate the phosphorylation of the 15 kDa sarcolemmal protein. CONCLUSIONS--These data indicate that the 15 kDa sarcolemmal protein, which may be phosphorylated by protein kinase C in vitro, is not a substrate for the same enzyme in beating guinea pig hearts.     

Translumbar catheter redirection using a tip-deflector technique

A new technique is described for reversing the direction of the catheter tip during translumbar aortography, without the need for partial withdrawal of the catheter from the aortic lumen. The method ensures optimal delivery of contrast medium at the desired level, while avoiding the risk of retroperitoneal bleeding or dislodgement during catheter manipulation.