Clinical and morphological aspects of shigellosis flexneri in patients with an aggravated premorbid state

The analysis of 10 fatal outcomes in patients with acute shigellosis during the period of 1999-2000 made it possible to find out that most of deceased shigellosis patients belonged to the group inclined to alcohol abuse and having initial alimentary disturbances. In 6 cases of acute shigellosis with fatal outcome the causative agent was S. flexneri 2a, in 2 cases--S. flexneri 3a, in 1--S. flexneri 4b. The main cause of fatal outcomes was accompanying double pneumonia. Lesions of the intestinal tract in deceased shigellosis patients were of destructive character, resulting, in a number of cases, in serous and perforative peritonitis.     

Beta-endorphin and endogenous alcohol level of the blood in alcoholic patients

Radioimmunoassay was used to measure the blood content of beta-endorphines in patients with chronic alcoholism. The concentration of endogenous ethanol in these patients was determined by gas chromatography. The blood concentration of beta-endorphines was found to be high in patients who showed atypical affective disorders off the period of abstinence. It is assumed that peripheral beta-endorphine is not linked with the development of the narcomanic syndrome proper but mirrors the pathogenetic mechanisms of psychopathological disorders. The levels of endogenous ethanol vary in alcoholics and healthy subjects within the same ranges. However, the percentage distribution indicates that in patients, they are shifted toward lower concentrations, which is likely to be conditioned by the induction of enzymatic systems that metabolize ethanol.     

Derivatives of N-amidinoproline and their use in conventional and solid phase peptide synthesis

N-Amidinoproline, a hybrid structure modeling key features of the Arg-Pro sequence, was synthesized. The activation of carboxyl group of free N-amidinoproline was found to result in the formation of a cyclic side product, whose structure was confirmed by ESI MS, ¹H NMR, and ¹³C NMR spectra. The preparation of N-(mesitylenesulfonylamidino)-L-proline using the mesitylenesulfonyl derivative of 2-methylisothiourea was demonstrated to be accompanied by partial racemization. The target product was synthesized by modification of N-amidinoproline by mesitylenesulfonyl chloride. The possibility of using N-amidinoproline in the N-terminal modification of a peptide chain was shown by the example of synthesis of an analogue of the 95–98 fragment of fibrinogen α chain.     

Characteristics of the benzodiazepine receptors in rats with different predispositions to the development of experimental alcoholism

A study was made of the density and affinity of benzodiazepine receptors in the cortex of the cerebral hemispheres and hippocampus of rats with different predisposition to alcohol consumption. No differences were revealed in the parameters under study in animals with varying duration of ethanol anesthesia and in rats after voluntary consumption of ethanol for 3.5 and 10 months. In a state of abstinence rats with physical dependence manifested a dramatic decrease in the density and affinity of benzodiazepine receptors in the cortex of the cerebral hemispheres. No changes described were detected in the hippocampus. The role of benzodiazepine receptors in the development of abstinence is discussed.     

Cell Ultrastructure in Azospirillum brasilense Biofilms

Microbiology - Due to the primary localization of both epiphytic and endophytic plant growth-promoting rhizobacteria on the surface of the plant root system, biofilm formation is an adaptive trait...     

Dynamics of the Functional Activity and Expression of Proteasome Subunits during Cellular Adaptation to Heat Shock

Molecular Biology - The ubiquitin-proteasome system (UPS) performs proteolysis of most intracellular proteins. The key components of the UPS are the proteasomes, multi-subunit protein complexes,...     

Gold(III) Reduction by the Rhizobacterium Azospirillum brasilense with the Formation of Gold Nanoparticles

For the soil nitrogen-fixing bacterium Azospirillum brasilense, the ability to reduce [AuCl₄]^? and to form gold nanoparticles (GNPs) has been demonstrated, with the appearance of a mauve tint of the culture. To validate the shapes and chemical nature of nanoparticles, transmission electron microscopy (TEM) and X-ray fluorescence analysis were used. For the widely studied agriculturally important wild-type strains A. brasilense Sp7 and Sp245, GNPs formed after 10 days of incubation of cell biomass with 0.25 mM [AuCl₄]^? were shown (using TEM) to be mainly of spherical form (5 to 20 nm in diameter), with rare occasional triangles. In the course of cultivation with [AuCl₄]^?, after 5 days, a mauve tint was already visible for cells of strain Sp245.5, after 6 days for Sp245 and after 10 days for Sp7. Thus, for the mutant strain Sp245.5 (which has significant differences in the structure and composition of cell-surface polysaccharides as compared with Sp245), a more rapid formation of GNPs was observed. Moreover, their TEM images (also obtained after 10 days) showed different shapes: nano-sized spheres, triangles, hexagons and rods, as well as larger round-shaped flower-like nanoparticles about 100 nm in size. Since by the time of GNP formation in our experiments the cells were found to be already not viable, this confirms the dominating role of cell surface structure and chemical composition in shaping the GNPs formed in the course of [AuCl₄]^? reduction to Au⁰. This finding may be useful for understanding the natural biogeochemical mechanisms of gold reduction and formation of GNPs involving microorganisms. The data obtained may also help in developing protocols for environmentally friendly synthesis of nanoparticles and possible use of bacterial cells with modified surface structure and composition for their fabrication.     

Stimulation of luminescence of mycelium of luminous fungus Neonothopanus nambi by ionizing radiation

The luminescent system of higher luminous fungi is not fully understood and the enzyme/substrate pair of the light emission reaction has not been isolated. It was suggested that luminescence of fungi involves oxidase‐type enzymes, and reactive oxygen species are important for fungal light production. Generation of reactive oxygen species can be stimulated by ionizing irradiation, which has not been studied for luminous fungi. We report the effect of X‐irradiation on the luminescence of fungus Neonothopanus nambi. Experiments were performed with mycelium on a home‐built setup based on an X‐ray tube and monochromator/photomultiplier tube. Application of X‐rays does not change the emission spectrum, but after approximately 20 min of continuous irradiation, light production from unsupported mycelium starts growing and increases up to approximately five times. After peaking, its level decreases irrespective of the presence of X‐irradiation. After staying at a certain level, light production collapses to zero, which is not related to the drying of the mycelium or thermal impact of radiation. The observed shape of kinetics is characteristic of a multistage and/or chain reaction. The time profile of light production must reflect the current levels of radicals present in the system and/or the activity of enzyme complexes involved in light production. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis of GnRH analogs and their application in targeted gene delivery systems

A set of GnRH analogues containing nuclear localization signal (NLS) of SV-40 virus large T-antigen have been synthesized using solid phase peptide synthesis and chemical ligation technique. Selective chemical ligation was achieved as a result of hydrazone formation in the course of interaction between NLS hydrazide and GnRH analog modified by pyruvic acid. The efficiency of synthesized peptide carriers was demonstrated in experiments with human cancer cells transfected by reporter luciferase and beta-galactosidase genes or suicide HSV-1 thymidine kinase gene. It was shown that selectivity of action on cancer cells can be achieved as a result of peptide/DNA complex penetration through the cell membrane by GnRH receptor-mediated endocytosis pathway.