[The comparative analysis of surgical procedures a in patients with benign prostatic hyperplasia and type 2 diabetes mellitus].

AIM: To compare the efficiency of two surgical methods, holmium laser enucleation of prostate (HoLEP) and laparoscopic retropubic simple prostatectomy with clamping of internal iliac arteries and vesicourethral anastomosis [LPA+CIIA+VUA]) for treating of patients with benign prostatic hyperplasia (BPH) and type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: A total of 56 men with T2DM who underwent surgical treatment of BPH in the National Research Centre for Endocrinology of the Russian Ministry of Health (director - corresponding member of RAS Mokrysheva N.G..) in a period from 2021 until 2022 were included in the study. Patients with T2DM received two types of antidiabetic drugs: basal-bolus insulin therapy and metformin (1000 mg/day per os). Patients were divided into the group of LPA+CIIA+VUA (n=28) and HoLEP (n=28). Preoperative, intraoperative and postoperative examinations with an evaluation of intraoperative and early postoperative complications (I, II, III, IV grades according to the Clavien-Dindo scale) were performed. After 1 year of follow-up, International Prostatic Symptom Score (IPSS), "Quality of Life" score (QoL), International Index of Erectile Function-5 score (IIEF-5), maximal urine flow rate (Qmax), and postvoid residual volume (ml) were assessed. Efficiency of surgical procedures was estimated according to "trifecta": absence of postoperative complications, urine continence, maximal urine flow (Qmax) >15 ml/sec. RESULTS: In the group of HoLEP, shorter postoperative bladder catheterization time but higher risk of urinary incontinence, bladder neck contracture and urethral strictures was found. LPA+CIIA+UVA leaded to a two-fold decrease in intraoperative hemoglobin loss with no necessity of repeat procedures. CONCLUSIONS: Our preliminary results demonstrated higher efficacy of LPA+CIIA+VUA for treatment of BPH in patients with T2DM than HoLEP. Patients who underwent LPA+CIIA+VUA were more often achieved the "trifecta". In order to implement LPA+CIIA+VUA into clinical practice, multi-center, large-scale, double-blind, placebo-controlled ("scar-surgery") randomized studies are required.

Complexes of hydrogen peroxide molecules with DNA nucleic bases.

The analysis of complexes formation of hydrogen peroxide molecule with DNA nucleic bases is carried out using methods of quantum chemistry. Optimized geometries of complexes are determined and the interaction energies that lead to complex formation are calculated. Comparison with the same calculations for water molecule is made. It is shown that complexes with hydrogen peroxide molecule are energetically more stable than the same complexes with water molecule. Such energetic advantage is achieved particularly due to geometrical properties of hydrogen peroxide molecule, especially presence of dihedral angle. Position of hydrogen peroxide molecule in close vicinity to DNA could lead to blocking of its recognition by proteins or direct damage via hydroxyl radical formation. These results can have significant impact in understanding of mechanisms of cancer therapy.Communicated by Ramaswamy H. Sarma.

Intensities of DNA ion-phosphate modes in the low-frequency Raman spectra.

The Raman intensities of counterion vibrations with respect to the phosphate groups of the double-helix backbone (ion-phosphate modes) in the low-frequency spectra (< 200 cm(-1)) of B -DNA with different alkali metal counterions have been calculated using the model for DNA conformational vibrations and the valence-optic approach. The results have showed that the spectra of DNA with heavy counterions (Rb(+) and Cs(+)) differ from the spectra of DNA with light counterions (Na(+) and K(+)). The calculated spectra of DNA with heavy counterions are characterized by intensive modes of ion-phosphate vibrations that form one united band near 115 cm(-1). Ion-phosphate modes in the spectra of DNA with light counterions are characterized by higher frequencies (near 180 cm(-1)) and much lower intensity. Our calculations explain why the modes of ion-phosphate vibrations are observed in Cs-DNA spectra rather than in Na-DNA. The determined sensitivity of the intensities of DNA low-frequency spectra to the counterion type proves the existence of the ion-phosphate modes.

Nanoscale stratification of local optical fields in low-dimensional atomic lattices.

We predict nanoscale field and dipole patterns due to the broken uniformity of a laser-driven local field in 1D and 2D lattices. They may result in size-related resonances and large field enhancement, which in turn can give rise to low-intensity nonlinear optical effects, e.g., optical bistability, even in the ultimate case of a pair of coupled atoms. At certain, "magic" numbers and configurations of atoms in a lattice, the system may exhibit the self-induced cancellation of the suppression of a local field.

Counterion vibrations in the DNA low-frequency spectra.

The vibrations of univalent metal cations with respect to phosphate groups of the DNA backbone are described using the four-mass model approach (S.N. Volkov, S.N. Kosevich, J. Biomol. Struct. Dyn. 8, 1069 (1991)) extended in this paper. The force constant of the counterion-phosphate interaction is determined by considering the DNA with counterions as a lattice of ion crystal. For such ion-phosphate lattice the Madelung constant and the dielectric constant are estimated. The obtained value of the Madelung constant is lower than for the NaCl crystal, and its value is about 1.3. The dielectric constant is within 2.3-2.7 depending on the counterion type and form of the double helix. The calculations of the low-frequency spectra show that for the DNA with metal cations Na(+) , K(+) , Rb(+) and Cs(+) the frequency of ion-phosphate vibrations decreases from 174 to 96 cm(-1) as the counterion mass increases. The obtained frequencies agree well with the vibrational spectra of polynucleotides in a dry state which prove our suggestion about the existence of the ion-phosphate lattice around the DNA double helix. The amplitudes of conformational vibrations for DNA in B -form are calculated as well. The results demonstrate that light counterions ( Na(+) do not disturb the internal dynamics of the DNA. However, heavy counterions ( Cs(+) have effect on the internal vibrations of the DNA structural elements.

Modeling B-a transformations of the DNA double helix.

An approach to the description of DNA conformational transformations of B-A type is presented. Due to the consideration of joint motions of DNA structural elements the model for DNA transformation is constructed in the two-component form. One component is the degree of freedom of the elastic rod, and another component - the effective coordinate of the conformational transformation. In the model the internal and external components are interrelated, as it is characteristic for DNA B-A rearrangements. It is demonstrated that kinetic energy of the double helix transformations of heterogeneous DNA can be put in homogeneous form. In the frame of the developed approach the possible localized excitations in a static state are found to compare with the experiments on DNA B-A deformability. The comparison shows good qualitative agreement between theory and experiment. The conclusion is made that the found excitations in the DNA structure may be classified as static conformational solitons, and that such localized excitations may play the key role in the mechanisms of DNA intrinsic bending.

Nonlinear optical interactions of wave packets in photonic crystals: Hamiltonian dynamics of effective fields.

We develop an effective-field formalism that is suitable for describing nonlinear interactions of multiple wave packets in photonic crystals of arbitrary dimensionality. The theory is valid for "high-contrast" variations of the refractive index in the photonic crystal, provided dispersion and absorption effects can be neglected; it is based on a Hamiltonian formulation of the underlying Maxwell equations. We show that the dynamical equations for the effective fields are similar to those commonly used in nonlinear optics of homogeneous media, but with coefficients determined from the photonic band structure. We can introduce an effective energy density and an effective Poynting vector, expressed in terms of the effective fields, that satisfy a continuity equation. We illustrate our approach with a solution of the problem of degenerate optical parametric amplification in the undepleted pump approximation, and by considering the linear electro-optic effect as a quadratic nonlinear optical process.

Exciton coherence and electron energy loss spectroscopy of conjugated molecules.

Signatures of the exciton coherence size, which controls the nonlinear optical response and luminescence of conjugated systems, in the electronic dynamic structure factor S(q,omega) are calculated. We find that for small molecules the momentum dependence of the lowest exciton resonance is purely geometric, reflecting the molecular size rather than a universal exciton size, as suggested recently. For long chains the q dependence is determined by the interplay of the exciton size and the bond-alternation length scales.

[Conformational stimulation in DNA type macromolecules]. / Konformatsionnye vozbuzhdeniia v makromolekulakh tipa DNK.

A concept for the description of structural elements mobility of a DNA-type macromolecule is suggested. The possible existence of conformational excitations weakly sensitive to a macromolecule heterogeneity in DNA is shown. The dependence of the macromolecule low-energy excitation spectrum on the nucleotide content is found and its sensitivity to thermal action is predicted.

Theory of low-frequency vibrations in DNA macromolecules.

To describe low-frequency dynamics of DNA macromolecules a model is developed taking into account the hydrogen bond stretching in base pairs, the backbone flexibility and intranucleoside mobility. For double-stranded DNA the normal vibrations are found and the structure of low-frequency spectrum is determined. The agreement between theory and Raman spectroscopy data for B-DNA is demonstrated. Conformational dependences of vibration spectrum during the B----A and helix----coil DNA transitions are studied. The contribution coming from low-frequency mobility to the nucleic-protein recognition processes is discussed.

Conformational transition dynamics and the mechanism of long-range effects in DNA.

A two-component model is proposed to describe the conformational dynamics of DNA macromolecule. A hypothesis on the mechanism of long-distance action transfer in DNA by local conformational transitions is presented. The conditions under which local transitions of B-A type are transmitted along a DNA chain are established.

[Conformation oscillations of DNA]. / O konformatsionnykh kolebaniiakh DNK.

A conformational mobility model is proposed to describe the low-frequency DNA structure dynamics. The transverse oscillations of structure elements in a double-stranded chain are studied. The frequency of DNA long-wave conformational oscillations are estimated and the theory is shown to agree with experiment. DNA low-frequency Raman spectra are interpreted.

[Mechanism of hydrogen exchange in DNA]. / O mekhanizme vodorodnogo obmena v DNK.

The hydrogen exchange mechanism of DNA bases imino- and amino protons is explained according to a suggested exchangeable state model. This state can be formed as a result of significant structural fluctuations which are not complete base pair openings. The exchangeable state model represents the hydrogen-bonded complex of two nucleotide bases and one water molecule made up dynamically. Quantum-mechanical calculations for the values of energy as the function of H-bond proton positions in the complex were carried out and the two-proton positions in the complex were carried out and the two-proton transfer is shown to be possible. The suggested model allows to give a noncontradictary interpretation of the hydrogen exchange data in double-helical polynucleotides.

[Effect of double helix conformation transitions on DNA hypochromism]. / O vliianii konformatsionnykh izmenenii dvoinoi spiralia na gipokhromism DNK.

The sensitivity of the first UV-absorption band hypochromism of DNA to changes in double helix form has been investigated theoretically. The hypochromism of DNA is studied within the perturbation theory and the nearest neighbour approximation. The heterogeneity of DNA is taken into account by introducing the nearest neighbour frequencies. The electronic characteristics of monomers (nucleotide bases) are calculated by the quantum mechanical PPP CI method. The hypochromism of A-, B-, C-, D- and T-forms of DNA is calculated. A slight dependence of the hypochromism on double helix conformation is obtained. This result is in agreement with experimental data. The reasons for the observed non-sensitivity of the DNA UV-absorption spectrum to conformational transitions within a two-stranded structure are explained. It is shown that the theory leads to an agreement with experiments because a large number of electronic transitions in nucleotide bases and the heterogeneity of DNA are taken into account.

[Theoretical study of the hypochromic effect in polynucleotides]. / Teoreticheskoe izuchenie gipokhromnogo effekta v polinukleotidakh

The first UV-absorption band hypochromicity of poly(dA)-poly(dT), poly(dG)-poly(dC), poly(dA), poly(dT), poly(dG), poly(dC), is calculated with the help of the perturbation theory. The wave functions of the bases are computed by Pariser--Parr--Pople's method taking into account all the singly excited configurations. The results obtained show a good correlation between the theoretical and experimental values of hypochromicity. A considerable influence of the vaccum electron transitions on the hypochromicity of polynucleotides is revealed. The origin of the hypochromic effect in the double-stranded polynucleotides is investigated. It is shown that intrastrand interactions between the bases make the main contribution to hypochromicity (60-76%), while the contribution of the Watson-Crick pairs is small (2-12%). The essential part of hypochromicity (22-28%) is due to the interstrand interactions between the bases which are not coupled by hydrogen bonds. The discussion of the experimental data shows that the present theoretical investigation could serve as a basis for correct treatment of experimental results.