Principles of the structural organization of the chemosensory system of freshwater gastropod mollusks]

Authors own experimental data and data available in literature were summarised to elucidate the influence of the mollusc environment and mode of living on structural organization of tentacular and osphradial systems, receptors of the mouth labia and mantle in typical freshwater mollusc. The similarity between sensory systems of tentacles, mouth and labia was demonstrated based on the findings obtained using silver impregnation, horse radish peroxidase labelling and electron microscopy. Module pattern of organization and peculiarities of sensory organs efferent innervation were demonstrated. Bilateral symmetry and the basis of multichannel structures of sensory systems central regions were described. Specific pattern of structural organization and those common with other animals were shown. The emphasis was made on differences from the olfactory systems of ground gastropods that consist in the lack of olfactory glomeruli, the special olfactory centres, procerebri and specialized chemosensory epithelium in freshwater mollusc.     

Analysis of polymorphism of the hypervariable locus of the apolipoprotein-B gene in populations of the Volga-Ural region

Data on the allelic polymorphism at the hypervariable locus 3' to the apolipoprotein B gene (apo B) in seven Turkic and Finno-Ugric human populations of the Volga-Ural region obtained by means of PCR method are presented. Sixteen allelic variants were distinguished, and the frequency distribution of alleles and genotypes across the populations studied were estimated. Alleles 34 and 36 appeared to be more common (from 13 to 45% in different populations); the calculated heterozygosity indices ranged from 59.3 to 73.4%. Comparison of the data with that on other world populations made it possible to deduce some specific features of the alleles frequency distribution associated with geographic position of the population.     

Energy and metabolic intercellular interaction in the growth region of Neurospora crassa

A major group of systemic autoimmune diseases is associated with abnormal lymphoproliferation, as a result of defects in the termination of lymphocyte activation and growth. Recent progress has been made in understanding the causes and consequences of these abnormalities. At the molecular level, the defects in CD95 and its ligand are only the most obvious reasons for the breakdown of 'clonal contraction' which in fact requires the participation of multiple gene products, including the IL-2-IL-2-receptor system, to set up a functional apoptotic machinery.     

Effect of ozone therapy on hemostatic changes in patients with vascular atherosclerosis

Hemostatic changed induced by ozone therapy were studied in 81 patients with atherosclerosis of different vessels in 81 patients. It was found that use of ozone-oxygen mixtures leads to hypocoagulatory changes (diminution of platelet aggregation, lowering of fibrinogen concentration, prolongation of activated partial thromboplastin time, enhanced fibrinolytic activity) which contribute to clinical response.     

Reactivity of isolated arteries: the role of their dynamic stretching

The smooth muscle constriction elicited by the NA or EFS was smaller when static stretching was replaced with a dynamic one in rats. The latter seems to activate the NO synthesis/secretion thus inhibiting the constriction and potentiating the dilation.     

Genotyping of Shigella flexneri 2a strains isolated from patients with acute dysentery in St. Petersburg

Polymerase chain reaction with universal primers (UP-PCR) was used for the genotyping of 76 S.flexneri 2a cultures isolated from patients with acute dysentery in infectious and psychoneurological hospitals of St. Petersburg. 9 types were determined, and each of them included cultures with identical UP-PCR patterns. The population of the infective agent was more heterogeneous in psychoneurological hospitals where the change of types was registered in May-September 1995. Some of these types were probably epidemic strains. UP-PCR was found to be a promising method increasing the efficiency of traditional epidemiological analysis.     

The effect of antioxidants on functional brain disorders caused by low-intensity ionizing radiation

The effects of daily intraperitoneal injections of alpha-tocopherol (30 mg/kg per day) and synthetic antioxidant IHFAN-30 (30 mg/day) in rats were compared during low-level ionizing radiation (10 days, dose rate 5 mGy/h, total dose 1.2 Gy). There were analysed: (1) amplitude of population spike of hippocampal slices; (2) endogenous phosphorylation in vitro of hippocampal synaptic proteins in the presence of cAMP; (3) formation, manifestation and reduction of food-procuring reflex. The findings showed that antioxidants made some correction of the functional state of hippocampal slices and cAMP-dependent phosphorylation system activity in brain cells from irradiated animals. No influence on training and memory functions was detected.     

Organizational problems of the production of biological preparations of blood

The trend of the incidence of tick-borne encephalitis makes one pay attention to the production of blood biological preparations. A detailed programme for improving the production process, which is included into the federal and republican programmes, is outlined.     

Synthesis and biodistribution of Bowman-Birk soybean protease inhibitor conjugate with amphiphilic polyester

We describe an adaptation of competitive RT-PCR to quantitate rat IFN-gamma mRNA expression. An IFN-gamma DNA mimic that shared the same primers and had an identical sequence to the target mRNA except for deletion of 66 nucleotides was created by a simple PCR amplification from target cDNA. To reduce variations of initial RNA concentrations, beta-actin cDNAs from each target RNA sample were normalized using the densitometric data. A known amount of pretitrated DNA competitor was then used to analyze the relative levels of target cDNA in different samples by PCR co-amplification. The amplification efficiency for both target and competitor remained constant throughout the PCR reaction, and the ratio of target to competitor PCR product remained proportional to the initial ratio of target to competitor. Relative mRNA levels among samples determined by this method were comparable to levels determined by northern blot analysis. They were also comparable to levels of IFN-gamma protein estimated by ELISA. We conclude that this method can be used to estimate the relative abundance of the target mRNA. This method is adaptable to quantitation of other cytokines and is particularly valuable if there are numerous samples or if the amount of initial mRNA is limited.