Solitonic-exchange mechanism of surface~diffusion

We study surface diffusion in the framework of a generalized Frenkel-Kontorova model with a nonconvex transverse degree of freedom. The model describes a lattice of atoms with a given concentration interacting by Morse-type forces, the lattice being subjected to a two-dimensional substrate potential which is periodic in one direction and nonconvex (Morse) in the transverse direction. The results are used to describe the complicated exchange-mediated diffusion mechanism recently observed in MD simulations [J.E. Black and Zeng-Ju Tian, Phys. Rev. Lett. {\bf 71}, 2445-2448(1993)].Comment: 22 Revtex pages, 9 figures to appear in Phys. Rev.

ANTI-INFLAMMATORY EFFECT OF CLOPIDOGREL IN ATHEROSCLEROSIS

Aim. To analyze the literary and own data about clopidogrel influence on platelets during inflammation and to reveal particularities of its usage in ischemic heart disease (IHD) patients with active inflammation. Material and methods. The platelet morphology and a number of leukocyte-platelet aggregates (LTA) were investigated with scanning electron microscopy in 110 patients with stable angina pectoris of I-III functional class and 18 healthy volunteers. Spontaneous and ADP-induced platelet aggregation were assessed with laser aggregatometre manufactured by LLC “BIOLA”. Mean platelet volume (MPV) was estimated with the hematological analyzer . All investigations were performed in IHD patients before and after 2 months of clopidogrel treatment 75 mg a day. Results. IHD patients demonstrated appearance of LTA and big reticular platelets in the blood, increase in MPV and spontaneous aggregation. ADP-induced platelet aggregation was rarely increased probably due to acetylsalicylic acid therapy in all IHD patients. These platelet activity changes are connected with increased risk of thrombotic events and correlated with inflammation markers levels. After 2 months of clopidogrel treatment LTA number reduced in 4 times and big reticular platelets number decreased in 2.5 times as well as MPV and spontaneous aggregation achieved the normal ranges. Conclusion. Clopidogrel has not only antithrombotic effect but also can diminish platelets morphological and functional changes connected with inflammation

Distribution of the HIV-1 resistance-conferring alleles (CCR5delta32, CCR2-64I, and SDF1-3primeA) in Russian, Ukrainian, and Belarusian Populations

The frequencies of three alleles, CCR5delta32, CCR2-64I, and SDF1-3primeA, known to decrease the risk of AIDS onset and the rate of the disease progression in HIV-infected individuals were determined in three native population samples from Russia, Ukraine, and Belarus. The frequencies of the alleles were 0.15, 0.12, 0.21; 0.12, 0.07, 0.20; and 0.12, 0.08, 0.26 for Russians, Ukrainians, and Belarussians, respectively. The proportion of the individuals without any of three protective alleles among Russians, Ukrainians, and Belarussians constituted 49, 65, and 61%, respectively. The genotype frequencies for the three loci studied were in Hardy–Weinberg equilibrium. Based on the three-locus genotype frequencies, the relative hazards of AIDS onset in HIV-infected individuals in each population were calculated as ranging from 0.79 to 0.88. In the samples of Eastern Slavs analyzed the estimated frequencies of the AIDS-protective alleles tested, as well as the frequencies of the corresponding genotypes and the relative hazards of AIDS onset were within the range of these parameters for the other European populations. The data on the allele frequencies and the relative hazard values in Russians, Ukrainians, and Belarussians can be used as the predictors of AIDS onset and progression rate in HIV-1-infected individuals from the populations studied

Paroxysmal supraventricular tachycardia in patient with dilated cardiomyopathy and concomitant cardiac conduction defects: a case report and discussion

Patients with dilated cardiomyopathy (DCM) often have intraventricular conduction disorders, which contribute to aggravation of heart failure, are progressive in most cases and can specify the prognosis of the disease. Paroxysmal supraventricular arrhythmias in such patients proceed with severe clinical manifestations, often accompanied by hemodynamic instability and syncope. A case report of patient (59 years old) with DCM, reduced left ventricular ejection fraction (35-37%), left bundle branch block, and paroxysmal orthodromic reciprocating tachycardia is presented. When an electrode was inserted on the right ventricular (RV) apex during the radiofrequency ablation, a third-degree atrioventricular (AV) block was recorded. This was maintained during the operation and was recurrent when trying to remove the electrode from the RV apex, and therefore there was a need for temporary and then permanent cardiac pacing therapy. Given DCM, reduced left ventricular ejection fraction, left bundle branch block, and the expected high percentage of RV pacing, a decision was made to implant a cardiac resynchronization therapy defibrillator. The literature review considers risk factors for formation of third-degree AV block during cardiac catheterization, methods of its prevention, as well as discusses the prognostic significance of catheter-induced conduction disorders, and indications for temporary and permanent cardiac pacing therapy