[Improvement of light-cured indirect inlays durability by means of electromagnetic field].

The main strength characteristics of light-cured resins used for replacement of dental hard tissues defects are destructive stress by compression, microhardness, resistance to abrasion, impact and water absorption. The study focuses on some strength features of composite materials for inlays processed by electromagnetic field. Four sample series of light cured resin (Charisma, Heraus Kulzer, Germany) were used to assess strength features changes in various curing methods: 10 control samples were polymerized by conventional light-curing device, while 30 were additionally processed by electromagnetic field of various intensity (60, 80 and 100 Oe, 10 samples for each group). The obtained results confirm the positive effects of electromagnetic field on strength features of light-cured resins which improves the quality of inlays.

[Effects of paracetamol and naproxen on pain syndromes of various genesis]. / Effekty paratsetamola i naproksena pri bolevykh sindromakh razlichnogo geneza.

A comparative study of the effects of two nonsteroidal antiinflammatory drugs paracetamol and naproxen on the pain syndrome models of various etiology showed that paracetamol is more effective in the case of spinal and neuropathic pain syndromes (in which the leading pathogenic mechanisms are related to the formation of hyperactive neuron aggregates in the central nociceptive structures). Naproxen was effective in the case of adjuvant arthritis, for which the main development mechanism is related to the accumulation of inflammation mediators in tissues. It is concluded that special features of the pathogenic therapy of various pain syndromes are determined by the character of prostaglandin participation in the pathological process.

Screening of sulfate-reducing bacteria in colonoscopy samples from healthy and colitic human gut mucosa.

A PCR-based approach combined with microbiological cultivation methods was employed to determine the occurrence of sulfate-reducing bacteria (SRB) in colon biopsy samples from ulcerative colitis patients and from non-colitic controls. The detection of mucosa-associated SRB was carried out by digoxigenin-dUTP-labelled PCR amplification, in liquid Postgate medium B and in a new liquid medium, termed VM medium I. Using Postgate medium B, the growth of SRB was confirmed in 92% of the colitic specimens and in 52% of non-colitic samples. However, PCR analysis and incubation in VM medium I detected SRB in 100% of biopsy material indicating ubiquitous presence of SRB in human colon mucosa.

The effect of super-oxidized water on Escherichia coli.

The mechanism of action of Sterilox, a non-toxic liquid biocide produced by electrolysis of a dilute saline solution, upon planktonic cells of Escherichia coli JM109 was investigated using protein and nucleic acid analysis. The results revealed total destruction of chromosomal and plasmid DNA, RNA and proteins of E. coli within 5 min of exposure. Our earlier investigation conducted using atomic force microscopy imaging revealed swelling and rupture of E. coli cells with release of cytoplasm. We propose that the biocidal properties of Sterilox are due to its effect upon constituents of the bacterial cell including proteins and nucleic acids.

Effect of akatinol (memantine) in central spinal pain syndrome.

On the model of central spinal pain syndrome in rats induced by application of penicillin to the dorsal surface of the lumbar spinal cord, akatinol injected intraperitoneally at the peak of syndrome or applied locally simultaneously with penicillin produced a dose-dependent analgesic effect. Intraperitoneal injection of akatinol at the peak of pain syndrome inhibited neuronal activity in spinal dorsal horn: the amplitude of total evoked neuronal response significantly decreased and the duration of action potentials returned to normal. It is concluded that activation of NDMA receptors plays a significant role in the development of central spinal pain syndrome, in particular spontaneous pain attacks, hyperalgesia, and tactile allodynia. Akatinol can be an essential component of the complex pathogenetic therapy of central pains.

[Effect of dopamine antibodies on neuropathic pain syndrome in rats]. / Vliianie antitel k dopaminu na razvitie neiropaticheskogo bolevogo sindroma u krys.

Dopaminergic brain system plays an important role in regulation of pain sensitivity. However, the data on participation of antidopamine antibodies in the development of neurogenic pain are absent. This work was aimed at the study of the role of antidopamine antibodies in the development of pain syndrome induced by the injury of nn. ischiadic and saphenous in rats. It was shown that after the nerve injury, the behavioral reaction such as autotomy (self-injury) appeared as a feature of the experimental neuropathic pain syndrome. It was originally established that the development of neuropathic pain syndrome induced by the injury of peripheral nerves was accompanied by induction of dopamine autoantibodies. It was also shown that immunization of the animals with conjugated dopamine-protein autigen resulted in aninerease of autidopamine antibody level and an amplification of the experimental neuropathic pain syndrome, i.e., decrease in the latency of the first autotomy, increase in expression of autotomies, and increase in the number of animals with late autotomies.

The effect of Pseudomonas NCIMB 2021 biofilm on AISI 316 stainless steel.

A bioreactor system operating in a continuous mode was designed to generate biofilms on polished and as-received surfaces of AISI 316 stainless steel coupons exposed for 36 d to a pure culture of marine Pseudomonas NCIMB 2021. Scanning electron microscopy (SEM) and atomic force microscopy were employed to determine the degree of surface colonisation and to examine corrosion damage of the steel. X-ray photoelectron spectroscopy analysis was carried out to characterise the chemistry of the passive layers on polished steel stored for a period of time, freshly re-polished coupons, and as-received steel. The effect of biofilms on the composition of layers formed on the steel specimens was evaluated. SEM revealed that the surfaces of polished and stored steel appeared to accumulate more biofilm compared to as-received specimens. Micropitting of steel occurred underneath the biofilm, regardless of surface finish. The concentration of elements in the passive layers differed significantly between freshly re-polished and as-received or polished and stored coupons. In the presence of Pseudomonas NCIMB 2021 biofilm, the composition of the passive layer on the as-received steel surface was considerably altered compared to unexposed steel or steel exposed to abiotic medium.

[The effects of L-arginine in chronic pain syndromes]. / Effekty L-arginina pri khronicheskikh bolevykh sindromakh.

The effect of L-arginine in long-term parenteral administration was studied on a model of neuropathic pain syndrome and adjuvant arthritis. L-arginine produced a preventive and therapeutic effect in the neuropathic pain syndrome. It weakened the development of adjuvant arthritis for the period of its administration. The factor underlying the effect of L-arginine is its double action as a precursor of nitrous oxide and kiotorphin, an endogenous antinociceptive dipeptide.

Study of the interaction of sulphate-reducing bacteria exopolymers with iron using X-ray photoelectron spectroscopy and time-of-flight secondary ionisation mass spectrometry.

Time-of-flight secondary ionisation mass spectrometry and X-ray photoelectron spectroscopy were employed to determine the interaction of crude extracellular polymeric substances recovered from static batch cultures of two isolates of marine sulphate-reducing bacteria of the genus Desulfovibrio, grown in the presence of and without mild steel surfaces, with Fe ions released from steel. The results demonstrated that exopolymers synthesised by different strains of sulphate-reducers varied in their ability to bind iron originating from steel. Based on the X-ray photoelectron spectroscopy analysis it is proposed that Fe released from steel was associated with bacterial exopolymers such as Fe(III) ion. The application of surface science techniques to study exopolymer/metal interaction allowed quantitative evaluation of Fe binding using small sample size.

[The effect of serotonin antibodies on the development of a neuropathic pain syndrome]. / Vliianie antitel k serotoninu na razvitie neiropaticheskogo bolevogo sindroma.

Serotoninergic and catecholaminergic neurotransmitter systems of the brain play an important role in the regulation of pain sensitivity. However, there are no data on the involvement of antibodies to the above neurotransmitters is the development of neuropathic pain syndromes. The authors' studies indicated that the development of neuropathic pain syndrome occurring after nerve damage is followed by the formation of serotonin antibodies and their enhanced induction caused by immunization of animals with serotonin-protein conjugated antigen aggravates the pain syndrome. Block and insufficiency of the serotoninergic antinociceptive system may be a cause of the progression of the pain syndrome due to serotonin antibodies.

The HsdR subunit of R.EcoR124II: cloning and over-expression of the gene and unexpected properties of the subunit.

Type I restriction endonucleases are composed of three subunits, HsdR, HsdM and HsdS. The HsdR subunit is absolutely required for restriction activity; while an independent methylase is composed of HsdM and HsdS subunits. DNA cleavage is associated with a powerful ATPase activity during which DNA is translocated by the enzyme prior to cleavage. The presence of a Walker type I ATP-binding site within the HsdR subunit suggested that the subunit may be capable of independent enzymatic activity. Therefore, we have, for the first time, cloned and over-expressed the hsdRgene of the type IC restriction endonuclease EcoR124II. The purified HsdR subunit was found to be a soluble monomeric protein capable of DNA- and Mg2+-dependent ATP hydrolysis. The subunit was found to have a weak nuclease activity both in vivo and in vitro, and to bind plasmid DNA; although was not capable of binding a DNA oligoduplex. We were also able to reconstitute the fully active endonuclease from purified M. EcoR124I and HsdR. This is the first clear demonstration that the HsdR subunit of a type I restriction endonuclease is capable of independent enzyme activity, and suggests a mechanism for the evolution of the endonuclease from the independent methylase.

Electron microscopic studies of sequence-specific recognition of duplex DNA by different ligands.

The following ligands were used to study sequence specific recognition of duplex DNA by electron microscopic techniques: methyltransferases BspR1 and EcoR124 (recognition sequences GGCC and GAAN7RTCG, respectively), a biotinylated deoxyoligonucleotide 5'-CTCTCTCTCTCTCT-3' capable of forming triplex DNA, and PNA oligomer H-T10-LysNH2. For each ligand the best conditions for electron microscopic (EM) detection of stable specific complex formation were determined. It was demonstrated that EM allowed us to determine the position of the individual target site with an error of 15-20 bp, the relative affinities for individual target sites and kinetic parameters of the binding. These results open new possibilities for EM investigations of sequence-specific interactions with a wide range of other ligands of a similar nature. They also imply that a wide range of different sequences can be unambiguously and precisely mapped by EM and greatly extend the scope of EM applications for physical mapping of genomic DNA.

Deletions within the DNA recognition subunit of M.EcoR124I that identify a region involved in protein-protein interactions between HsdS and HsdM.

The DNA recognition subunit (HsdS) of type I restriction endonucleases can be divided into domains by means of amino acid identity between subunits from the same family. It has been proposed that DNA-protein interactions occur within the variable domains of the subunit and that protein-protein interactions involve the conserved domains. We have constructed a number of deletion mutants of HsdS that have allowed us to investigate protein-protein interactions. Using a combination of a "competitive" complementation assay and the ability of HsdM to "solubilize" HsdS, we have defined a region within the central conserved domain of HsdS that is responsible for HsdS-HsdM interaction. Computer analysis of amino acid identity between the N-terminal half and the C-terminal half of HsdS identifies a region (repeated in both conserved domains), one copy of which overlaps the region we have identified as essential for HsdS-HsdM interactions, which may be responsible for such protein-protein interactions.