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We studied the resistance of human blood T and B lymphocytes to cold anabiosis (-20 degrees C, -40 degrees C, and -80 degrees C) of different duration.

Experimental and theoretical methods were employed to study the effects of torso shape and heart orientation in the thoracic cavity on peculiarities of the formation cardiac electric field on the body surface in dogs. It was found that heart orientation to a greater extent than torso shape affected projections of cardiac electric potentials from the epicardium onto the body surface.

The membranotropic effects of TVF tanacetan pectin polysaccharide derived from Tanacetum vulgare L. was studied by the voltage-clamp method on isolated neurons of Lymnaea stagnalis mollusk. TVF in concentrations of 0.1-10.0 microg/ml nonselectively activated the outward potassium and total inward (sodium and calcium) ionic currents (slightly dose-dependently and reversibly increased their amplitude by 5-10%) and decreased nonspecific leakage current.

We studied changes in phagocytic activity of neutrophils and lymphocytes subjected to cold anabiosis. The proposed effective method for introduction of human blood leukocytes into cold anabiosis at moderately low temperature (-40 degrees C) in the presence of a cryopreserving agent does not require washout of the biological material after defrosting.

We propose a method of constriction of the renal artery consisting in pulling of a loop of isolated artery into a thin plastic tube with calibrated inner diameter. This method can be used in experiments with constriction of other small blood vessels to diminish the local blood flow.

Left ventricular hypertrophy of the hearts in Wistar rats caused by renovascular hypertension prolongs depolarization of epicardial surface of the ventricles and increases the duration of excitation phase in the left ventricular epicardium. Sex-related differences in changes of myocardial contractility were revealed during hypertrophy of the left ventricle caused by renovascular hypertension.

The relationship was studied between radiation-induced apoptosis in the nervous system of Drosophila larvae and the age dynamics in adult fly neuromuscular activity. The level of apoptosis in the neural ganglia of third-instar larvae from the wild-type strain increased 2.5 times after larval exposure to ionizing radiation (54 cGy). Irradiation of the strain with enhanced sensitivity to apoptosis induction, which carries a mutation in gene-inhibitor of apoptosis th (allele th4), and the wild-type strain Berlin led to an increase in neuromuscular activity of adult flies throughout the experiment and, consequently, to reduced aging rate. Conversely, this effect was not observed in strains with reduced sensitivity to induction of apoptosis (with mutations in genes dArk and Dcp-1).

Two fractions that included acid arabinogalactan and pectin were extracted from the callus culture of duckweed plants (Lemna minor L.) with water and ammonium oxalate. Residues of galactose and arabinose in the 2.0-2.5:1 ratio were the major constituents of acid arabinogalactan. The pectin fraction contained primarily residues of glucuronic acids, galactose, and arabinose. The percentage of arabinogalactan and pectin was similar. The yield of polysaccharide fractions did not depend on the method for their isolation. Extraction with water, treatment of the biomass with an aqueous solution of formalin and diluted hydrochloric acid, and extraction with an aqueous solution of ammonium oxalate allowed us to obtain the highest-purity pectin polysaccharide.

We propose a simple, effective, and economic method for introducing human blood leukocytes in cold anabiosis at moderately low temperature (-50 degrees Celsius).

Effects of separate and combined action of 232Th and Cd on Allium cepa root tip cells were investigated. It has been shown that cytogenetic effects of 232Th results mainly from its ability to induce genome damages. Cadmium in the examined concentration does not induce chromosomal vagrants, and this effect is not intensified by the combined action of 232Th and Cd (with 232Th). Cd induced increased aberrations of chromosome type frequency (1.5 times more than in control group), and fragment frequence, while mitotic index was significantly decreased. While taking into consideration the frequency of anaphase--telophase damages, and the number of aberrations per cell, the combined effects of 232Th and Cd may be considered as synergic. The aberration type ratio, frequencies of bridges and fragments, and also the level of proliferative activity of 232Th and Cd in the presence of both ions were similar with the corresponding parameters obtained when Cd acted alone. Possible mechanisms of formation of 232Th and Cd synergic effects are discussed.

Silenan SV, a pectic polysaccharide, was isolated from the aerial part of Silene vulgaris (Moench) Garke (Oberna behen (L.) Ikonn.), widespread through the European North of Russia. The polysaccharide was found to contain residues of galacturonic acid (63%), arabinose, galactose, and rhamnose as the main constituents. The results of a partial acidic hydrolysis, pectinase digestion, and NMR studies of silenan SV indicated that its molecule contains a linear alpha-1,4-D-galacturonan backbone and ramified regions. The core of the ramified regions is composed of residues of alpha-1,4-D-galacturonic acid along with 2-substituted alpha-rhamnopyranose residues. The NMR data showed that the silenan SV side chains are composed of the blocks built from the terminal alpha-1,5-linked arabinofuranose and beta-1,4-linked galactopyranose residues; these most likely are the side chains of rhamnogalacturonan, characteristic of other pectic polysaccharides. The nonreducing ends of these side chains contain alpha-arabinofuranose residues.

In studying the beta-xylosidase production by yeast Cryptococcus podzolicus (Basidiomycetes), it was shown to be an inducible secretory enzyme. Xylooligosaccharides generated from xylan and methyl beta-xyloside were found to induce the beta-xylosidase synthesis. The enzyme activity in the medium containing xylan or methyl beta-xyloside was 1.0 and 1.5 U/ml, respectively; this production level is similar to that achievable at the beta-xylosidase production by mycelial fungi.

Recent investigations showed that genetic instability accounts for many radiobiological effects. However, mechanisms underlying this phenomenon are still poorly understood. Assuming that mobile genetic elements may be involved in the induction of genetic instability, we studied parameters that characterize the activity of these elements in Drosophila melanogaster: hybrid dysgenesis and the level of recessive lethal mutations. In our experiments, we used D. melanogaster strains that differed in the type of hybrid dysgenesis (P-M and H-E). It was demonstrated that chronic exposure to radiation leads to substantial changes in the genetic structure of a population and an enhanced level of dysgenic sterility. Our results indicate that genetic instability and adaptation to the effect of chronic gamma-radiation are associated with the radiation-induced mobilization of mobile genetic elements.

Longevity is a temporal characteristic dependent on the level of equilibrium between the damaging and restorative processes in an organism. This is a complex parameter determined by both genotypic and external factors. In experiments with the mutant strain of Drosophila melanogaster mei-41D5, it was demonstrated that chronic exposure to low-dose radiation can change the longevity of flies. A decrease in the longevity of both males and homo- and heterozygous females of this strain was also caused by specific inducers of apoptosis. We suggest that apoptosis plays a certain role in the aging of an organism and that the dominant gene mei-41D5 takes part in determining longevity in Drosophila.

Water-soluble polysaccharide fractions VO1-VO4 were isolated from the squeezed berries of snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of alpha-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of beta-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of alpha-arabinofuranose at a Gal: Ara ratio of 3:1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus.

Under both separate and combined influence of 232nd-nitrate and potassium nitrate a study was made of the yield of somatic mutation frequencies, the level of morphologically abnormal cells and the loss of reproduction integrity in the stamen hairs of Tradescantia (clone 02). All investigated concentrations of 232nd-nitrate and potassium nitrate exerted statistically significant genotoxic effects and increased the level of morphological cell abnormalities in the stamen hairs of Tradescantia. Also, 0.36 mg/l 232nd and 0.51 mg/l KNO3 concentrations cause a statistically significant loss of reproduction integrity in the stamen hair. The combined action of 232nd-nitrate and potassium nitrate in all investigated concentrations and parameters causes a statistically significant effect.

The results of studies on the chemical structure and physiological activity of phanerogam polysaccharides, accumulated within the last two decades, are reviewed. Three types of polysaccharides are considered: rhamnogalacturonans (pectins and related gums and mucilages, type A), acidic arabinogalactans (mainly plant mucilages, gums, and some hemicelluloses, type B), and neutral glucans and heteroglycans (reserve polysaccharides, type C). Various physiological activities of these plant polysaccharides are discussed, with particular emphasis being placed on their immunomodulatory action. The data available on the relationship between chemical structure and physiological activity of plant polysaccharides are considered. Information on the medicinal use of some plants containing physiologically active polysaccharides is presented.