EBV-based plasmid DNA rearrangements after transfection of eukaryotic cells

The cDNA encoding influenza virus (A/Udorn/307/72 strain) M2 protein was subcloned into the EBV-based vector pREP9. Three continuous kidney cellular lines of different origin were transfected with recombinant plasmid pREP9-M2. One and 5 months after transfection plasmid DNA rearrangements were detected by means of restriction analysis of recovered plasmids and their hybridization with an influenza-virus-specific radioactive probe. Deletions were the most frequent type of pREP9-M2 mutations. PCR with primers corresponding to cellular genome and plasmid DNA followed by Southern blot analysis with the [(32)P]-labeled M2-fragment allowed host DNA rearrangements to be revealed in transfected cells.     

Catalytic and stereoselective properties of the immobilized amidase of Rhodococcus rhodochrous 4-1

Applied Biochemistry and Microbiology - The amidase of Rhodococcus rhodochrous 4-1 was immobilized by covalent attachment to activated chitosan by physical sorption on carbon adsorbents and by the...     

Altered Balance of Macroelements and Trace Elements in Blood Serum, Its Ultrafiltrates, and Hairs Long after Exposure to Low Doses of Ionizing Radiation

Using inductively coupled plasma atomic emission spectrometry, we examined the level of Al, Cd, Co, Cu, Fe, Mg, Mn, Mo, P, Pb, S, and Zn in blood serum, its ultrafiltrates, and hairs of liquidators of the Chernobyl Nuclear Power Plant accident who were working in the disaster region in 1986–1987. Studies continued over a period of time provided evidence for a distinct change in the balance of macroelements and trace elements in the studied biological substrates of irradiated individuals. An increase in the level of copper in the ultrafiltrate and a marked decrease in the content of zinc in the ultrafiltrate are viewed as key factors in the generation of a response to low doses of ionizing radiation. Concerning the content of iron in hairs, we demonstrate its accelerated removal from the body of liquidators. The altered balance of biotic macroelements, phosphorus, and sulfur remained unchanged when these characteristics were studied as a function of time. We found changes in the ratios of divalent cations, magnesium and zinc, in the ultrafiltrates. The magnesium concentration in the studied biological substrates was the most stable characteristic after irradiation. The level of toxic trace elements (lead, cadmium, and aluminum) did not exceed physiologically acceptable levels, while their content in hairs may be a biological indicator of their accumulation in the body.     

The use of Pseudomonas sp. M plasmid pM3 for the transposon mutagenesis of Erwinia

The transposon containing derivatives pMTF9 (Tn9), pMTF10 (Tn10) and pMTF59 (Tn5, Tn9) of the Pseudomonas sp. M conjugative plasmid pM3 demonstrating temperature-dependent instability in Erwinia cells incubated at 37 degrees C have been isolated. The obtained plasmids have been shown to be usable for transposon-mediated mutability in the bacterial cells of Erwinia generum incubated at 37 degrees C.     

The immunological effectiveness of small doses of diphtheria and tetanus anatoxins in the revaccination of children with allergy-altered reactivity and adults

The possibility of decreasing the content of antigens in adsorbed diphtheria-tetanus toxoid, used for the booster immunization of children with allergically altered responsiveness and adults, is shown. Diphtheria toxoid in doses of 1-2.5 Lf and tetanus toxoid in doses of 1-2.5 binding units possessed sufficiently high immunological effectiveness in combination with low reactogenicity and good tolerance. In 6-12 months after booster immunization with decreased doses of toxoids 100% of children with allergy of different character and, respectively, 86-94% and 95% of adults have developed protective levels of antibodies to diphtheria and tetanus.     

Immunosuppressive properties of vinblastine and colchicine]

The action of vinblastine and colchicine on the populations of antibody-forming cells, their precursors and stem cells using a model of primary immune response and in the transplantation system was studied using techniques by Jerne and Nordin (1963), Kennedy et al. (1965), and Till and McCulloch (1961). It was discovered that vinblastine and colchicine, at single administration 48 hours after immunization, inhibited immune response completely. The administration of colchicine and vinblastine to a donor gave an exponential decrease of in foci-forming cell number in a recipient in the system of syngenic transfer. But at the same time, vinblastine at small doses stimulated population of antibody-forming and stem cells, whereas at large doses it was not effective. Colchicine, in contrast, strongly inhibited both antibody-forming and haemopoietic cells in the recipient.     

The single administration of ethanol and the amplitude of the action potentials of the neocortical neurons in rats: extracellular studies]

On outbred rats the influence was studied of acute administration of moderate dozes of ethanol (150 mg--1.2 g/kg, intraperitoneally) on the motor cortex neurones. It was shown that ethanol in the range of these dozes led to a change of the amplitude of extracellularly recorded action potentials, which could be directed to an increase or decrease. In the used range minimum as well as maximum dozes in various animals might elicit contrary effects, i.e. no dependence was observed of the direction of reaction of the studied neurones on the administrated doze. Possible mechanisms are discussed which may be the basis of the change of the amplitude of extracellular action potentials. Conclusion is made that use of moderate dozes of ethanol is a useful condition for studies directed to a search of mechanisms of initial reaction to alcohol action.     

Clinical Characteristics of Seizures and Epilepsy after Ischaemic Stroke

Human Physiology - Ischaemic stroke (IS) is a frequent cause of epilepsy.The aim of the study was to clarify the clinical features of post-stroke epilepsy (PSE). We examined 38 patients with...     

The impact of synthetic nitriles on the morphology and viability of some bacterial species

The toxic effects of synthetic nitriles and nitrile herbicides on some bacterial species were estimated. Biotests based on bioluminescence revealed that aromatic nitriles including herbicides had the most significant toxic effect on bacteria, which differed from their effect on eukaryotic cells. It was shown that soil strains of nitrile-utilizing bacteria were resistant to high concentrations of the studied compounds. The minimal bactericidal concentrations for most of nitriles were 0.5 M or above. It was demonstrated that exposure to 0.1 and 1 mM bromoxynil solution resulted in a decrease in the linear parameters of the cells of all strains and sufficient changes in the cell surface of Gram-negative bacteria. It was proposed that the toxic effect of aromatic herbicides was caused not only by inactivation of an enzyme of the electron-transport chain but also by damage to the surface structures.