The effect of ionizing radiation on nitrosamine formation from anthropogenic precursors]

The kinetics of formation of nitrosoamines from precursors under the effect of ionizing radiation has first been quantitatively estimated, and the optimal conditions of their formation determined. The possibility of formation of nitrosoamines under the effect of low-level radiation has been investigated. Using the mathematical functions obtained from the experiments, the number of nitrosoamines, that may form under the effect of radiation in the aqueous medium, has been determined.     

Stability of plant vacuolar membranes under the conditions of osmotic stress and influence of redox agents

Stability of plant vacuolar membranes (tonoplast), which underwent two types of osmotic stress and also the effect of redox agents (glutathione in its oxidized (GSSG) and reduced (GSH) forms) and nitric oxide (NO) under various pH values, has been investigated. The fatty-acid content of tonoplast has also been determined. It has been shown that stability of vacuoles decreased under hyperosmotic stress but not under hypoosmotic stress. These effects are unlikely caused by the fatty-acid content of vacuolar membranes. Stability of vacuoles changed under various redox conditions; this process was more intensive under the conditions of hypoosmotic stress in the experiments with oxidized glutathione. The influence of nitrogen oxide was different for various kinds of stress: stability of vacuoles decreased substantially under hypoosmotic stress, while under the conditions of hyperosmotic stress NO elevated the stability level of the vacuolar membranes.     

On Use of Transformed Auxiliary Information in Probability Proportional to Size Method of Sample Selection

A probability proportional to size (PPS) method of sample selection, based on the transformed auxiliary information as the measure of size, has been suggested. It has been observed that the PPS estimator under the suggested method is always better than the simple random sampling with replacement (SRSWR) and the usual PPSWR estimator. The efficiency of the proposed estimator with respect to the estimators under reference has also been empirically compared.     

Activity and characteristics of the regulation of glycolytic proteins in Staphylococcus aureus

Lactate has been determined to be the ground glyucolysis product in the staphylococci strains under study. Acetate and CO2 are produced in small quantities. Considerable differences in storing lactate under aerobic and unaerobic conditions have not been found. Pasteur effect reaches 20.5--23.3%. The controlling glycoysis unit study has shown that it may locate on the different sections of Embden-Meyergof-Parnas pathway. The key regulation enzyme activity of hexokinase, phosphofructokinase and pyruvatekinase has been determined.     

Structural bases of the plasticity of the nervous system

The present state of morphological study of variability in the nervous elements under conditions of adaptive change under the influence of afferent effects, age changes during different periods of ontogenesis, under conditions of de- and regeneration of synapses have been considered. A question on correlation between structure and the function of synapses during the change has been analysed. The tasks of subsequent study of this problem have been outlined.     

Structural and functional changes in the mitochondrial apparatus of cortical tubules of the solitary kidney in chronic blockade of cholinergic mediation

In 15, 30 and 90 days the effect of continuous atropine pharmacological blockade of parasympathetic innervation on morphometrical characteristics of epithelial mitochondria in the cortical segments of the canaliculi has been studied in a single kidney of Wistar rats. The maximal degree of the alternative changes has been determined in the proximal canaliculi. In the distal canaliculi epithelium a compensatory increase of the main quantitative parameters in mitochondria has been registered. The plasticity of the mitochondrial apparatus, specific for the collecting tubules under compensatory hypertrophy, is inhibited under conditions of deparasympathization.     

Effect of actoprotectors on Ca, Mg-dependent ATPase activity in the sarcoplasmatic reticulum of rabbit muscles

The effect of different chemical compounds on Ca, Mg-dependent ATPase (Ca-ATPase) sarcoplasmic reticulum (SR) hydrolytic activity as well as their actoprotecting (AP) activity, the ability to increase organism's resistance under muscle stress and antihypoxanthic (AH) activity to increase the organism's survival under conditions of low pressure has been studied. The compounds with AP-activity have been shown to be strong inhibitors of Ca-ATPase SR hydrolytic activity. No correlation between AP-activity of the compounds and their effect on Ca-ATPase SR has been found. The membranotropic activity of actoprotectors has been shown by electronic paramagnetic resonance method. A suggestion has been made to use Ca-ATPase SR as a tested object during the forecasting actoprotecting activity of new chemical compounds.     

The mechanisms of the porphyrin conformation of normal blood hemoglobin and in pathology]

The spectra of resonance Raman scattering of blood in norm and under pathology (myocardial infarction and sepsis), as well after artificial hemotransfusion or UV photomodification have been studied. It has been shown that under heart pathology the structure of hemoglobin porphyrin macrocycle of erythrocytes changes, the size of porphyrin "nucleus" increases. The opposite conditions are observed at blood sepsis. It has been found that the traditional methods in tissue restoration, hemotransfusion and UV photomodification of blood don't result in complete restoration of hemoporphyrin molecule.     

Additives to biological substances. V--The stability of lactose as a carrier for Biological Standards

The stability of freeze-dried lactose has been studied, by accelerated degradation, after being ampouled under the conditions employed for the preparation of International Standards and Reference Preparations and also under less stringent conditions which might facilitate degradation. The possible formation of the reactive product, 5-hydroxymethyl-furfural, has been monitored over a period of 10 years at temperatures up to 56 degrees C. No evidence has been obtained to suggest that the formation of this compound would present a hazard to the stability of standards prepared by the procedures customarily employed.     

Neuraminidase of Corynebacterium diphtheriae

Neuraminidase activity has been found in a variety of strains of Corynebacterium diphtheriae, both toxinogenic and nontoxinogenic. The enzyme has been shown to be intracellular, possibly associated with the cytoplasmic membrane. Toxinogenic strains of the diphtheria bacillus, grown under conditions unsuitable for maximal toxin production, produce neuraminidase, and the enzyme has been purified from cells of the Park Williams no. 8 strain grown under such conditions. Diphtherial toxin and diphtherial neuraminidase have similar molecular weights and remain associated during column chromatography; immunochemically, and in their electrophoretic behavior, they appear distinct.     

Modeling of steady-state and relaxation elastic properties of the papillary muscle at rest

The biomechanical modeling of a papillary muscle preparation as an adequate object for studying the properties of the myocardial tissue under uniaxial stretching has been performed. The steady-state and relaxation tests of the papillary muscle of laboratory animals (rabbit and rat) have been conducted in normal conditions and after the maceration of intracellular structures with high ionic strength solution. It has been shown that the main contribution to the viscoelastic properties in the initial range of physiological deformations is made by the connective tissue skeleton, whereas under large physiological deformations, by intracellular structures.     

The role of the carboxamide group in nicotinamide adenine dinucleotide in relation to hydride transfer: the reduced form of the dinucleotide as remedy in the modulation of neurotransmission

The stereochemical significance of the carboxamide group in combination with the ring nitrogen in NADH-NAD+ conversions has been demonstrated. This has been shown in model systems as well as under enzymatic conditions. The role of the carboxamide group in selective regiospecific interactions has been discussed for neurodegenerative diseases.     

Improved synthesis of oligodeoxyribonucleotide using 3-methoxy-4-phenoxybenzoyl group for amino protection.

3-Methoxy-4-phenoxybenzoyl group has been used for the protection of exocyclic amino group of nucleosides. In case of 2'-deoxycytidine it has been found to be highly selective under controlled conditions. The N-protected derivatives of 2'-deoxyadenosine and 2'-deoxyguanosine have been found to be sufficiently stable towards acids minimising depurination under conditions of synthesis of oligodeoxyribonucleotide on solid support via phosphotriester approach. The high lipophilicity of the group and milder deprotection conditions are additional advantages.     

A General Class of Ratio‐Type Estimators Under Super‐Population Model

The problem of constructing classes of estimators for population mean has been widely discussed by various authors under design approach in sample surveys. An attempt by Upadhyaya , Singh , and Vos (1985) has been made to combine the usual mean and ratio estimator with suitable weights in order to define a general class of estimators. This paper is an attempt to study properties of the same estimator under super‐population model. Optimum weights have also been proposed. Results have been supported with some numerical examples.     

Comparison of the effects of bax-expression in yeast under fermentative and respiratory conditions: investigation of the role of adenine nucleotides carrier and cytochrome c.

A new system for bax-expression in yeast has been devised to investigate bax's effect under fermentative and respiro-fermentative conditions. This has allowed us to show unambiguously that the ability of bax to kill yeast is higher under respiratory conditions than under purely fermentative conditions. The extent of killing under respiro-fermentative conditions (non-repressive sugars) is intermediate. It has been proposed that the two proteins adenine nucleotides carrier (ANC) and cytochrome c play a crucial role in bax-induced cell death. We have investigated the effects of deletion of the genes encoding the two proteins on the toxicity induced by bax, using this new system. The absence of ANC did not modify bax-induced lethality in any way. Moreover, the absence of cytochrome c also did not prevent bax-induced death. Only the kinetics of lethality were altered. All these effects are prevented by co-expression of bcl-xL.     

Contemporary status of the Sterlitamak steppe corridor

The work examines contemporary climate, soil cover, and vegetative cover of the southern forest-steppe in the Bashkir Cis-Ural region. Functioning of natural complexes in changing climate has been analyzed. Dynamics and transformation of the complexes under the impact of natural and anthropogenic factors have been investigated. Contemporary vegetative cover has been studied and the percentage of synanthropic species has been determined.     

Survival of Coxiella burnetii in soil

For the first time the survival of Coxiella burnetii of five types in soils has been studied. The survival of C. burnetii has been found to depend on the content of organic substances in black earth, as well as soil temperature. The method for the prevention of an epidemic outbreak of Q fever directly under the natural conditions has been proposed.     

Synthesis and molecular structure of 14,15-pyrrolidino-and 14,16-ethano derivatives of estrone

Hydrolysis of 3-methoxy-16alpha-nitro-14,17-ethenoestra-1,3,5(10)-trien-17beta-yl acetate under weakly basic conditions leads to formation of 3-methoxy-2'-oxopyrrolidino-[4',5':14beta,15beta]-estra-1,3,5 (10)-trien-17-one, the structure of which has been confirmed by X-ray analysis and some chemical transformations. The reactivity of 3-methoxy-16alpha-nitro-14,17-ethanoestra-1,3,5(10)-trien-17beta-yl acetate under various conditions of basic hydrolysis has been investigated. The derived compounds have been identified by means of NMR spectroscopy and X-ray analysis.     

Equivalence of certain models in protein ligand equilibria and the possibility of distinguishing between them

Methods have been developed for analyzing the binding of ligand by a protein exhibiting allosteric properties. The procedure has been developed for the case of four subunits. The relationship to existing theoretical models has been discussed. The conditions under which a choice between models is feasible are described.     

Studies on the Metabolism of Gallic Acid by Microorganisms

The intermediary metabolism of gallic acid by Aspergillus niger under the influence of some added inhibitors has been studied. The decomposition of gallic acid by lyophilized cells under fluoroacetate inhibition allowed cis-aconitic acid, α-ketoglutaric acid and citric acid to accumulate. A mechanism of gallic acid decomposition via cis-aconitic acid has been inferred.