[Influence of exposure to immobilisation stress on blood concentration of TNF alpha and IL-4 in rats active and passive in the open field test].

The influence of exposure to immobilization stress on TNF alpha and IL-4 concentrations in blood was studied in behaviorally active vs. passive in the open field Wistar rats. One hour after exposure to stress, blood concentrations of TNF alpha and IL-4 were significantly lower in behaviorally passive as compared to active rats and passive controls not exposed to stress. Moreover, in passive rats exposed to stress, the pituitary weight increased as compared to passive controls. Behaviorally passive rats exposed to emotional stress were characterized by a decreased blood levels of TNF alpha and IL-4 as compared to behaviorally passive controls and behaviorally active animals exposed to stress.

Demonstration of a laser vorticity probe in turbulent boundary layers.

A laser-based probe for the nonintrusive measurement of velocity gradient and vorticity was demonstrated in turbulent boundary layers. Unlike most other optical methods, the current technique provides an estimate of the velocity gradient, without having to first measure velocity at multiple points. The measurement principle is based on the heterodyne of coherent light scattered from two adjacent particles. The beat frequency of the heterodyne is directly proportional to the velocity gradient. The probe is assembled from commercially available, inexpensive optical components. A laser Doppler velocimeter (LDV) processor is used to analyze the heterodyne signal. A component of vorticity is obtained by using two appropriately aligned velocity gradient probes. The optical probes developed were used in turbulent boundary layers to measure local, time-frozen velocity gradients partial differential u / partial differential y, partial differential v / partial differential x, and partial differential v / partial differential y, as well as the spanwise vorticity. The measurements were compared to those inferred from LDV measurements in the same facility and to data available in the literature.

[Site-specific expression of single-stranded antibody fragments in Nicotiana tabacum].

Antibody expression and immunomodulation are modern molecular techniques to produce pharmaceuticals and to interfere with cellular metabolism or pathogen infectivity in plants. Nonetheless, there is still no generally applicable strategy to express correctly folded active antibodies or antibody fragments in different cell compartments. To facilitate expression, single-chain antibody fragments (scFvs) were made of mouse monoclonal antibodies, J2 and P6 that specifically recognize double-stranded RNA (dsRNA). Stabilizing double-stranded replication intermediates could modulate the biological activity of dsRNAs in plants, especially to influence virus replication. Along with cytoplasmic expression, scFvs were anchored to the plasma membrane; targeted to the apoplast for secretion and made ER-resident. Expression levels were analysed and transgenic plants were evaluated for resistance or tolerance to potato virus Y infection. We have established strategies for expression of correctly assembled antibodies or antibody fragments in different plant cell compartments.

[The effect of salvin on the growth and ultrastructure of Staphylococcus aureus 209P]. / Vliianie sal'vina na rost i ul'trastrukturu Staphylococcus aureus 209P.

Antibiotic salvin obtained from Salvia officinalis has been studied for its effect on the growth and ultrastructure of Staphylococcus aureus 209P. The antibiotic in the sub-bacteriostatic concentration considerably elongates the lag-phase (up to 11-12 h) exerting no significant effect on the growth rate of the staphylococcus population as well as it prolongs duration of the exponential phase. The analysis of electronograms of staphylococcus cells subjected to the action of salvin in the concentrations similar to the minimal inhibitory concentration (MIC), has revealed the cell thinning, inhibition and destruction of the division. The introduction of 5MIC antibiotic into the exponentially grown culture made a cell wall considerably thinner, destructing its external layer; the number of lyzed cells sharply increased. The appearance of bodies not described previously with a membrane envelope and ribosomes as well as of mesosomal structures was observed.

[Bacteria reducing chromium in nature and in effluents of industrial plants]. / Bakterii, vosstanavlivaiushchie khrom v prirode i v stokakh proizvodstvennykh predpriiatii.

Bacteria capable of hexavalent chromium (Cr6+) reduction can be found in Cr6+-containing sewage and sediments of purification tanks of industrial plants. They cannot be detected in water and soil samples containing no chromium compounds. Bacteria reducing chromium belong to the genera Aeromonas, Escherichia, Pseudomonas and Enterobacter. Their activity of Cr6+ reduction correlates with the high resistance to the elevated content of this ion in the medium. The fine cell structure of these bacteria is described.

[Effect of antibiotic AL-87 on the growth and ultrastructure of staphylococci]. / Vliianie antibiotika AL-87 na rost i ul'trastrukturu stafilokokkov.

The effect of antibiotic Al-87 on the ultrastructure of staphylococcal cells was studied. The cells of a control culture of a sensitive strain of S. aureus, 209P at the early exponential growth phase were characterized by thin walls (20-22 nm) and septa (30 nm). In the presence of the subbacteriostatic concentration of antibiotic AL-87 (0.02 microgram/ml) the thickness of the cell walls and septa increased up to 80-90 and 150 nm, respectively. Segregation of the septa was retarded and 4 cell conglomerates formed. The cell division appeared to be highly active: the septa were detected in 80-90 per cent of the sections against 40 per cent in the control. Therefore, antibiotic AL-87 induced significant thickening of the cell walls and impairment of the cell division regulation. Investigation of the staphylococcal variant resistant to the antibiotic showed that there were no significant differences between the cells grown in the absence and presence of antibiotic AL-87 (in a concentration of 200 micrograms/ml). In both the experiments there were detected cells in their majority with thinner walls, L-form-like structures, protoplasts and single conglomerates of the cells with thicker walls and anomalous division and the cells at the moment of lysis. It suggested that the effect of antibiotic AL-87 on the cell wall structure was not direct i. e. by inhibition of protein synthesis but mediated i. e. due to shifts in lipid synthesis inducing changes in lipid-dependent synthesis of the cell wall polymers.

[Nuclear origin of peroxisomes, the probable precursors of mitochondria in hydrocarbon-oxidizing yeasts of the genus Candida]. / O iadernom proiskhozhdenii peroksisom--veroiatnykh predshestvennikov mitokhondrii v uglevodorodokisliaiushchikh drozhzhakh roda Candida.

On studying the ultrathin sections of the Candida yeast cells, continuously and periodically cultured in the mineral medium with n-alkanes it has been shown that microbodies (peroxisomes) may be present both in the nucleus and in the perinuclear zone form which they are able to migrate into the cytoplasm. The endoplasmatic reticulum, the Golgi apparatus and mitochondria are not presumably involved structurally in the appearance of microbodies. The data were presented on close structural and functional resemblance between microbodies and mitochondria. It is supposed that in n-alkane-assimilating cells Candida microbodies may be precursors of mitochondria.