The formation of a test system for assessing the safety of different types of pertussis preparations: their cytotoxic action on mouse thymocytes in vitro

The test for the evaluation of the toxicity of different types of pertussis preparations as manifested by their in vitro influence on mouse thymic cells (T test) has been finally worked out. The use of the T test has made it possible to reveal the nonstandard character of the production lots of adsorbed diphtheria-pertussis-tetanus vaccines, both whole-cell vaccine and Japanese acellular vaccine. The degree of the in vitro damaging action of pertussis preparations on mouse thymic cells greatly depends on the residual content of Bordetella pertussis nontoxoidized toxin which, in contrast to B. pertussis lipopolysaccharide and filamentous hemagglutinin, produces pronounced cytotoxic action on mouse thymic cells.     

Feeding and reproduction of XX Ctenophthalus wagneri Tifl., 1928 (Ctenophthalmidae, Siphonaptera) in experiments]

Under laboratory conditions at 20 to 21 degrees C young imagos of C. wagneri proceed quickly to feeding and reproduction. They suck blood about three times a day and females oviposit three times, each laying consisting of three eggs. When placed in a refrigirator at 2 to 5 degrees some young individuals lay eggs, while others do not start oviposition up to 5 months (observation period). Fleas, which already laid eggs under laboratory conditions, being transferred into a refrigirator decrease the degree of their attachment to the host and feeding frequency (up to one time a day). Oogenesis of females is inhibited and most of them cease egg laying.     

Function-Triggering Antibodies to the Adhesion Molecule L1 Enhance Recovery after Injury of the Adult Mouse Femoral Nerve

L1 is among the few adhesion molecules that favors repair after trauma in the adult central nervous system of vertebrates by promoting neuritogenesis and neuronal survival, among other beneficial features. In the peripheral nervous system, L1 is up-regulated in Schwann cells and regrowing axons after nerve damage, but the functional consequences of this expression remain unclear. Our previous study of L1-deficient mice in a femoral nerve injury model showed an unexpected improved functional recovery, attenuated motoneuronal cell death, and enhanced Schwann cell proliferation, being attributed to the persistent synthesis of neurotrophic factors. On the other hand, transgenic mice over-expressing L1 in neurons led to improved remyelination, but not improved functional recovery. The present study was undertaken to investigate whether the monoclonal L1 antibody 557 that triggers beneficial L1 functions in vitro would trigger these also in femoral nerve repair. We analyzed femoral nerve regeneration in C57BL/6J mice that received this antibody in a hydrogel filled conduit connecting the cut and sutured nerve before its bifurcation, leading to short-term release of antibody by diffusion. Video-based quantitative analysis of motor functions showed improved recovery when compared to mice treated with conduits containing PBS in the hydrogel scaffold, as a vehicle control. This improved recovery was associated with attenuated motoneuron loss, remyelination and improved precision of preferential motor reinnervation. We suggest that function-triggering L1 antibodies applied to the lesion site at the time of injury over a limited time period will not only be beneficial in peripheral, but also central nervous system regeneration.     

Hydrochemical balance of Itkul–Shira lake system (Khakassia,Russian Federation)

The water and hydrochemical balance of Shira and Itkul lakes, located in the arid (steppe) zone in the Republic of Khakassia (Russian Federation), has been calculated. It is shown that Lake Itkul can be considered a drained lake, which significantly determines the basic differences of the hydrochemical balance in the two water bodies. The outflow of water from Itkul to Shira is, on average, 6791000 m3/year, and the average outflow of dissolved salts is 35697 t/year. Lake Shira can be considered a drainless water body with an evaporation mechanism of formation of the chemical composition of its waters, and Lake Itkul is considered a flowing water reservoir. The salt concentration in Itkul is not as high as that in Shira due to the lower influence of evaporation on the formation of the chemical composition of waters and time of their interaction. It has been assumed that this phenomenon is regular, rather than exceptional, for the arid zone of Northern and Central Asia.     

Blood antigens in the AB0 system and susceptibility of humans to diphtheria

The analysis of a large number of diphtheria cases (1326) at the peak of diphtheria morbidity in Russia (1993-1994) revealed that the intensity of antidiphtheria antitoxic immunity was age-dependent with a sharp immunodeficiency in the population aged 35 years and older. As adaptive capacity of the organism decreases, the positive associative links between immunity to diphtheria and the AB0 blood groups become evident. Populations with phenotype B (III) had the largest diphtheria immune stratum at the age of 35 years and over as compared to 3 other phenotypes. The genotypic analysis of serological data may be of practical importance for the detection of the degree of predisposition of humans to infectious diseases.     

Flavonoid Production in Transformed Scutellaria baicalensis Roots and Ways of Its Regulation

A root culture of skullcap (Scutellaria baicalensisGeorgi) transformed with pRi T-DNA was initiated by the inoculation of sterile seedlings with Agrobacterium rhizogenes(wild-type strain A-4). The flavonoid concentration in cultured roots comprised 5% of the root dry weight and was maintained essentially constant during a subculture. For four weeks of culturing, the weight of the roots increased by 20–30 times; when the roots were cultured for a longer time and with periodic enrichment of the nutrient medium, their weight increased 50-fold. Skullcap roots were shown to synthesize flavones characteristic of intact roots (wogonin, baicalein, and baicalin). The addition of 0.01–1 mM L-phenylalanine (a precursor of flavonoids) to the nutrient medium affected neither root growth, nor their flavonoid concentration. Root elicitation with 100 M methyl jasmonate for 72 h increased the flavonoid content per flask and per root dry weight by 1.8 and 2.3 times, respectively.     

Interaction of Plum Pox Virus with Specific Colloidal Gold-Labeled Antibodies and Development of Immunochromatographic Assay of the Virus

Two monoclonal antibodies (mABs) raised against plum pox virus (PPV) were shown to recognize its D, M, and C strains. Conjugates of the antibodies with colloidal gold (CG) nanoparticles averaging 26 nm in diameter were synthesized. The binding constants of PPV with both the native and conjugated mABs were determined using a Biacore X device. The complexes between the CG-mAB conjugates and plum pox virions were examined by means of transmission electron and atomic force microscopy. Using the conjugates with optimal component ratio, an express immunochromatographic assay of PPV was developed with a detection limit of 3 ng/ml and duration of 10 min. The assay was tested for PPV detection in sam- ples of stone fruit tree leaves and demonstrated a good compatibility with the data obtained by “sandwich”-ELISA. The developed assay can be used in the field and applied for monitoring viral infection and for quarantine purposes.     

Influence of soddy-podzolic soil improvement on the abundance and structure of complexes of epigeic predatory beetles (Coleoptera: Carabidae,Staphylinidae) in Northwestern Russia

Improvement of soddy-podzolic soils results in an increase of species richness and abundance of the most common epigeic predatory ground beetle and rove beetle species (Coleoptera: Carabidae, Staphylinidae) in the agrocenoses of Northwestern Russia.