[Possibilities of preventive treatment of Alzheimer's disease: results of the 3-year open prospective comparative study on efficacy and safety of the course therapy with cerebrolysin and cavinton in elderly patients with the syndrome of mild cognitive impairment].

The study was conducted in 3 Russian centers (Moscow, St. Petersburg and Nizhniy Novgorod). The total sample included 110 patients whose mental state met the definition of <> (MCI). Patient's status was assessed with widely used scales (MMSE, GDS, CDR etc) and a battery of neuropsychological tests. Genotyping for the APOE polymorphism was performed as well. Patients were stratified into 2 comparable groups in compliance with the specifics of therapy: 55 patients were treated with cerebrolysin and 55 - with cavinton. The superiority of cerebrolysin over cavinton in slowing down of the cognitive deficit progression and delaying the time or transition of patients to the diagnostic category of Alzheimer's disease was demonstrated. Cerebrolysin was particularly effective in MCI patients with the ApoE(+) genotype, i.e. in those with higher risk for Alzheimer's disease. Adverse effects during the treatment were rare in both groups.

Two-dimensional solitons and vortices in normal and anomalous dispersive media.

We study solitons and vortices described by the (2+1)-dimensional fourth-order generalized nonlinear Schrödinger equation with cubic-quintic nonlinearity. Necessary conditions for the existence of such structures are investigated analytically using conservation laws and asymptotic behavior of localized solutions. We derive the generalized virial relation, which describes the combined influence of linear and nonlinear effects on the evolution of the wave packet envelope. By means of refined variational analysis, we predict the main features of steady soliton solutions, which have been shown to be in good agreement with our numerical results. Soliton and vortex stability is investigated by linear analysis and direct numerical simulations. We show that stable bright solitons exist in nonlinear Kerr media both in anomalous and normal dispersive regimes, even if only the fourth-order dispersive effect is taken into account. Vortices occur robust with respect to symmetry-breaking azimuthal instability only in the presence of additional defocusing quintic nonlinearity in the strongly nonlinear regime. We apply our results to the theoretical explanation of whistler self-induced waveguide propagation in plasmas, and discuss possible applications to light beam propagation in cubic-quintic optical materials and to solitons in two-dimensional molecular systems.