[Thermoadsorptive separation of DNA by size using a polymeric sorbent].

The article describes theoretical aspects of isolation and separation of DNA fragments by size using a polymeric sorbent. On this basis we presented a theoretical model of thermal desorption of DNA fragments of different length. Assuming that, under certain pH, interaction of DNA with the polymer sorbent is of an ion-dipole character and moving dipoles interact with the sorbent according to the Boltzmann distribution with the total charge of the DNA fragment in its pore, the expression for the interaction energy as a function of temperature is obtained. Equating the thermal energy to the interaction energy of the ion-dipole character, we have found the critical temperature of DNA separation from the sorbent. Account of the conformation of single-stranded DNA in the coil form leads to the dependence of DNA separation temperature, i.e., desorption, on the length of the DNA chain. The temperature for desorption increases symbatically to the contour length of DNA.

[Quantum theory of the hydrogen key in DNA].

A quantum theory of the redistribution of the hydrogen atom that links nucleotide bases between two DNA strands at the moment of its untwisting has been advanced, which is based on two tunneling mechanisms: the Andreev-Meierovich mechanism of tunneling with spontaneous emission of a phonon and the Kagan-Maksimov mechanism of tunneling during the scattering of the phonon. It was shown that the probability for the hydrogen atom to be in a foreign pit, i.e., in the mutated form, decreases as the rate of untwisting increases. According to the model, the probability of mutation smoothly increases with temperature to a value of 1/2.

[Modified surgical treatment of rectal atresia with rectovaginal fistula]. / Modifitsirovannyi sposob khirurgicheskogo lecheniia atrezii priamoi kishki s priamokishechno-vlagalishchnym svishchom.

In our clinics in 1992-2002 89 girls with anorectal developmental anomaly underwent modified perineal proctoplasty. In 65 (73.3%) patients the rectal atresia with vestibular fistula was revealed, in 17 (19%)--vaginal fistula, 7 (7.7%)--perineal fistula. After modified perineal proctoplasty carry out the good result is achieved in 37 (85%) patient, satisfactory one--in 6 (13%), nonsatisfactory (incontinence of feces)--in 1 (2%).