[Diagnostic value of ventricular late potentials, heart rate variability and QT dispersion in patients with acute myocardial infarction]. / Diagnosticheskoe znachenie pozdnikh potentsialov zheludochkov, variabel'nosti serdechnogo ritma i dispersii intervala Q-T u bol'nykh infarktom miokarda.

Late ventricular potentials (LVP), heart rate variability (HRV) and dispersion of QT interval (QTd) were studied in 91 patients with myocardial infarction with various ventricular arrhythmias. Patients with episodes of sustained ventricular tachycardia (group 4) had the following characteristics: prevalence of LVP 73.7%, QTd 82.5 ms, standard deviation of RR intervals (SD) 26.5 ms; spectral analysis of HRV revealed preponderance of sympathetic influences and lowered vagal activity. Frequency of LVP detection, QTd and SD in patients with ventricular extrasystoles (Lown classes 3-5) (group 3) were 33.3%, 72.8 ms, and 42.8 ms, respectively. Patients of group 3 also had augmented sympathetic and lowered parasympathetic influences. These data significantly differed from those obtained in patients with Lown class 1-2 ventricular extrasystoles (group 2) and patients without extrasystoles (group 1). Groups 3 and 4 had significantly different prevalences of LVP and values of some HRV parameters but similar QTd. There was close correlation between presence of severe ventricular arrhythmias and some parameters of HRV and signal averaged ECG. Stepwise regression analysis showed that the following group of parameters was related to the presence of malignant ventricular rhythm disturbances: heart rate, SD and total QRS duration (p<0.05). Thus patients with life threatening ventricular arrhythmias were characterized by the presence of LVP and changes of some parameters of HRV and QTd. Registration of these parameters can apparently be used for prediction of potentially fatal ventricular arrhythmias in patients with myocardial infarction.

Development of human antibodies against linear antigenic and immunogenic regions of respiratory syncytial virus (RSV) nucleocapsid and phospho-proteins shows the site-directed characteristics.

BACKGROUND: The successful development of an RSV vaccine requires a better understanding of the pathogenesis of primary infection, susceptibility to reinfection, and the immunopathology of enhanced illness in children immunized with a non-replicating RSV candidate vaccine. The exact role of different immune parameters in RSV pathogenesis remains controversial. OBJECTIVES: To study the contribution of antibodies directed to the linear antigenic and immunogenic regions of the N and P proteins in the titer rise and avidity maturation of total anti-RSV antibodies. STUDY DESIGN: The occurrence of antibodies directed against three linear antigenic and immunogenic regions in each of the nucleocapsid (N): N3 (Thr11 to Gly30), N25 (Ser231 to Ala250) and N39 (Thr371 to Leu391), and the phospho-(P) proteins of respiratory syncytial virus (RSV), subgroup A: P49 (Pro91 to Asp110), P56 (Ser161 to Lys180) and P62 (Glu221 to Phe241), were analyzed in ELISA with (a) 32 paired sera from humans with recent or previous RSV subgroup A and/or B infection diagnosed by conventional ELISA, detection of antigen in nasopharyngeal aspirates and measurement of antibody avidity change; and (b) 40 RSV antibody-positive sera (HCS) obtained from patients during their convalescence from RSV infection and possessing clearly demonstrable titers of RSV IgG in conventional enzyme immunoassays (EIA) based on whole RSV antigen. RESULTS: The titer rise of antibodies directed to the combined three peptides representing the RSV N protein was well correlated with the rise in anti-RSV antibodies measured in whole antigen ELISA. Surprisingly, the rise in antibodies against a truncated main C-terminal epitope (Gln381 to Leu391) of the N protein (represented by subgroup A specific sequence of the N39/1 peptide) was inversely correlated with the titer rise of total anti-RSV antibodies. The titer rise of antibodies to the C-terminal linear site of the RSV N (N39/1) protein was subgroup-specific during the course of primary RSV infection. A titer rise in antibodies to the C-terminal linear sites of RSV N (i.e. N39/1) and P (P62) proteins had a dominating appearance in sera from newborn infants (6-7 months) and from patients with RSV reinfections. Anti-RSV antibody titers of late convalescent sera correlated with the titers of antibodies directed to the C-terminal linear site of RSV P (P62) protein. The avidity maturation of the anti-RSV immune response followed the titer rise of anti-P62 antibodies during the course of primary or secondary RSV infection.