Peculiarities of primary and secondary structure of phage FI-1 DNA

The composition of nitrous bases of phage FI-1 DNA was studied. As is evidenced from the values of buoyant density in CsCl (p=1,7093 g/cm(3)), melting temperature (T degrees m=86,05 degrees), spectral parameters and direct chromatographic determination, the DNA analysed contains 41,5 mole% pairs of guanine-cystosine. 5-hydroxymethylcytosine and other anomalous bases were not found. Chemical identification and jaxtposition of data of buoyant density in CsCl and Cs2SO4 (p=1,4466 g/cm(3)) and T degrees m. showed the presence of the extra-sugar component in DNA, most likely in the form of hentibiose. Spectral character of thermal denaturation of DNA in different solvents is indicative of the double helixity of its structure. DNA is characterized by enthalpies of conformational transitions "helix coil" (deltaH=12,3 kcal/g) and (deltaH=10 kcal/g) for the solvents, 1 x SSC, and 0,1 x SSC, correspondingly. The presence of extra-sugar in DNA with standard set of nitrous bases is discussed.     

Echography in congenital intestinal obstruction in newborn infants

The authors used echography in order to reveal typical echographic signs of high and low bowel obstruction in 51 newborns. Although the use of echography often fails to establish the real cause of the bowel obstruction, it allows the determination of its level and in general promotes making the proper diagnosis.     

The enhancement of the efficacy of patient orthodontic treatment based on the mathematical modelling of prospective implant designs

Opportunities to increase prosthetic treatment efficiency by means of applying osseointegrated implants of traditional and prospective types are analysed. A technique of mathematical modelling of the interaction between implants and jaw bone is exposed. The numerical model and applied program, developed on the basis of finite element method, enabling to analyse a stress strain state of the bone and to determine extreme safe loads on implants are described. It is shown, that the most loaded zone is a layer of the compact bone directly contiguous to the neck of the implant. That is in good agreement with the results of clinical research, according to which just this zone has the highest percentage of complications. Methods for further optimisation of implants and prosthetic structures for the purpose to perfect the techniques of prosthetic treatment are discussed.     

Epidemiology of tuberculosis in Tashkent and ways of its improvement

Radioimmunoassay of beta-endorphine (RIA) in plasma was performed in patients with acute, subacute and chronic neurosensory hypoacusis. The RIA and audiological examination were made before treatment and after combined therapy consisting of pharmacopuncture and following low-frequency electrostimulation using negative polarity current. The above treatment elevated beta-endorphine levels in blood plasma. Positive results of the treatment correlated with elevated beta-endorphine levels in the end of the treatment.     

Macromolecular organization and biochemical characteristics of the genome of phage FI-1

The molecular weight of phage FI-1 DNA is determined by the methods of sedimentation and kinetics of reassociation, as well as from buoyant density values of virion components and specific partial volume of DNA (85X10(6) daltons). The spectral analyses showed that the distribution of guanine-cytosine pairs along the whole length of the molecule is Gaussian. The DNA content in the particle of FI-1 makes up to 41%, which is 7% less as compared to the morphologically related phage T4. The protein component analysis of phage FI-1 demonstrated that the genome of this virus is capable to encode at least 20 different proteins. Possible reasons for differences in the molecular weights of the genomes of T4 and FI-1 phages are discussed.     

Changes in the morphofunctional status of the capillary system of the cerebral cortex in cats exposed to adrenergic stimulation while prostaglandin biosynthesis is inhibited

Experiments were made in cats to study the morphological and functional state of the capillary system of the brain in response to adrenaline administration and stimulation of the sympathetic cervical nerve under conditions of prostaglandin biosynthesis inhibition. In the presence of indomethacin administration there occurs potentiation of the vasoconstrictor effect of noradrenaline as well as of stimulation of the sympathetic nerve although to a less extent. It is assumed that the effect of exo- and endogenous noradrenaline on cerebral microcirculation is related to a definite measure to prostaglandin endogenous biosynthesis whose inhibition may lead to potentiation of the adrenergic effects thereby creating a risk of cerebrovascular spasms. Evidence for adrenergic control at the level of the capillary system of the cerebral cortex is discussed.     

Cytotoxic properties of the complex of the antineoplastic antibiotic bleomycetin and Bacillus intermedius ribonuclease

It was shown possible to change the cytotoxic properties of the antitumor antibiotic bleomycetin by its binding to Bacillus intermedius RNAse. The complexing lowered the antibiotic effect on DNA in the cells of the human amnion. At the same time the experiments with human red blood cells indicated that RNAse of B. intermedius in complex with bleomycetin-Fe(II) increased the antibiotic capacity for the cell membrane break down.     

Crystallization of poly(ethylene oxide) confined in pores of active carbon

The kinetics of isothermal crystallization of poly(ethylene oxide) confined in pores of active carbon was studied by nuclear magnetic resonance relaxation. At equal temperatures the induction period of crystallization in pores differs from that in the bulk polymer. A model was developed that allows estimation of the effect of porous media on the statistical sum of the macromolecule considering the change of the polymer chain conformation in the melt. This model describes the following observed effects: invariability of the induction period temperature dependence in pores, the weak temperature dependence of the ratio of induction period for e bulk, and pore material. The change in the induction period in cylindrical pores was predicted with satisfactory precision.     

Dependence of the antitumor activity of nitroso alkyl urea derivatives on their chemical structure

The antitumour activity of 10 analogs of nitroso alkyl urea was studied on 6 tumour strains. It was shown that antitumour effect depends upon the gentle structural changes of substances (changes of side chain, the position of aromatic nucleus in it, as well as the nature, quantity and position of substitutes in the nucleus). 7 compounds out of 10 analogs of nitroso alkyl urea have manifested antitumour activity.