[Sudden death in school-aged children at physical exercise: forensic diagnosis]. / Vnezapnaya smert' detei shkol'nogo vozrasta pri fizicheskoi nagruzke: sudebno-meditsinskaya diagnostika.

OBJECTIVE: Acomprehensive forensic study of cases of sudden death of school-age children during physical exertion and sports. Investigated 9 cases of sudden death of children aged 8 to 17 years that occurred during exercise. It was studied anthropometric indicators, histological and biochemical studies to identify changes in internal organs and the cardiovascular system. The forensic medical characteristics of sudden death cases of schoolchildren are given. Along with the constitutional features, the characteristic changes in some tissues and internal organs in particular the heart and blood vessels were determined. The data obtained make it possible to develop an algorithm and propose a methodological approach for diagnosing sudden death of school-age children. The results of the study can be used as additional forensic criteria for assessing the risk of sudden death of children during physical activity.

[The efficacy of remaxol addition in the treatment of alcohol withdrawal syndrome].

OBJECTIVE: To study the efficacy of remaxol addition in the treatment scheme of alcohol withdrawal syndrome. MATERIAL AND METHODS: Eighty patients with alcohol dependence and physical symptoms of alcohol withdrawal syndrome were enrolled. All patients received basic therapy in accordance to the applicable standards of treatment. The patients were randomized to remaxol introduced intravenously 2 times a day (morning and afternoon) in dose of 400 ml for 7 days (n=40) and saline with 25%-magnesium sulfate (10 ml) and 4% potassium chloride (10 ml) (n=40). RESULTS: The effectiveness of the inclusion of remaxol was expressed in a more rapid relief of asthenic syndrome, reduction of phenomena such as tension, dysphoria, headache and impaired coordination of samples. Patients treated with remaxol demonstrated a trend towards a more rapid reduction of the affective (p=0.08) and behavioral components (p=0.09) of the syndrome of pathological craving for alcohol. Hepatoprotective and detoxification properties of the drug were confirmed by the significant decline in ALT and AST activity to the 20th day of treatment. Significant positive changes in lipid metabolism (HDL to the 7th day of treatment) and a normalizing effect on the processes of tissue respiration were shown as well. No adverse effects were noted. CONCLUSION: The data obtained allow to recommend the inclusion of remaxol in the complex treatment regimens of alcohol withdrawal syndrome to improve the treatment efficacy.

Numerical framework to model temporally resolved multi-stage dynamic systems.

Numerical modeling of steroid hormone signaling presents an exciting challenge involving spatiotemporal coordination of multiple events. Ligand binding in cytoplasm triggers dissociation and/or association of coregulators which subsequently regulate DNA binding and transcriptional activity in nucleus. In order to develop a comprehensive multi-stage model, it is imperative to follow not only the transcriptional outcomes but also the intermediate protein complexes. Accordingly, we developed a software toolkit for simulating complex biochemical pathways as a set of non-linear differential equations in LabVIEW (Laboratory Virtual Instrumentation and Engineering Workbench, National Instruments, Austin, TX) environment. The toolkit is visual, highly modular, loosely coupled with the rest of LabVIEW, scalable and extensible. The toolkit can be used to develop and validate biochemical models and estimate model parameters from existing experimental data. We illustrate the application of the toolkit for simulation of steroid hormone response in cells, and demonstrate how the toolkit can be employed for other biological and chemical systems as well. The software module presented here can be used stand-alone as well as built into data collection and analysis applications.

Guanidinium chloride-induced spectral perturbations of 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid confound interpretation of data on molten globule states.

We describe limitations in the use of 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) to examine unfolding intermediates associated with guanidinium chloride (GuHCl)-induced protein denaturation. Several studies have used alterations in fluorescence emission of bis-ANS to quantify the population of "molten globule" states. Our findings indicate that the observed changes in bis-ANS spectroscopic properties could originate from the interactions of bis-ANS and GuHCl and the aggregation of the dye at higher GuHCl concentrations. We posit that in the absence of additional complementary structural or spectroscopic measurements, the use of bis-ANS emission alone to monitor protein conformations can be misleading.

Role of the androgen receptor CAG repeat polymorphism in prostate cancer, and spinal and bulbar muscular atrophy.

Androgens are involved in the development of several tissues, including prostate, skeletal muscle, bone marrow, hair follicles, and brain. Most of the biological effects of the androgens are mediated through an intracellular transcription factor, the androgen receptor (AR) at the level of gene regulation. Several types of mutations in the AR gene have been linked to endocrine dysfunctions. The expansion of CAG codon repeat, coding for a polyglutamine (PolyQ) tract in the N-terminal domain is one such mutation. The polyQ chain length impacts AR's ability to interact with critical coregulators, which in turn modulates its transcriptional efficacy. Pathologic manifestations of variations in polyQ chain length have been associated with prostate cancer susceptibility, and the Spinal and Bulbar Muscular Atrophy (SBMA), a neurodegenerative disease. In this review article, we discuss multiple aspects of the role of polyQ chain length in the actions of the AR, their importance in prostate cancer development and progression, and SBMA with an aim to understand the underlying mechanisms involved in these diseases, which can be targeted for future therapeutic approaches.

Catalytic role of calix[4]hydroquinone in acetone-water proton exchange: a quantum chemical study of proton transfer via keto-enol tautomerism.

Calix[4]hydroquinone has recently attracted considerable interest since it forms stable tubular aggregates mediated solely by hydrogen bonding and pi-pi-stacking interactions. These aggregates trap specifically various small organic molecules and, in particular, catalyze the proton exchange of water with acetone. Using correlated quantum chemical methods, the mechanism of the observed proton exchange mediated by keto-enol tautomerism of acetone is investigated in detail. Starting with an investigation of keto-enol tautomerism of acetone-water clusters, it appears that four catalytic water molecules are optimal for the catalysis and that additional solvent water molecules lead to a decrease in efficiency. Analyses of the partial charges revealed a decrease of the polarization of the reactive hydrogen bonds due to the additional water molecules. As a next step, hydroquinone-acetone-water complexes were studied as models for the situation in the CHQ moieties. However, the computations revealed that the proton transfer reaction becomes less efficient when one catalytic water molecule is replaced by hydroquinone. Although concerted proton transfer via keto-enol tautomerism of acetone seems to be the predominant mechanism in supercritical water, it is no longer the rate-determining reaction mechanism for the catalyzed acetone-water proton exchange observed in tubular CHQ. Nevertheless, a key feature of the catalytic function of tubular CHQ has been identified to be the stiff hydrogen bonding network and the exclusion of additional solvent water molecules.

[The thermodynamic stability of nanoconstructions based on the double-stranded DNA molecules].

The temperature stability of nanoconstructions formed by double-stranded DNA molecules fixed in the structure of their liquid crystalline dispersions and cross-linked by nanobridges was determined. It was shown that the heating of nanoconstructions is accompanied by a decrease in the amplitude of the negative bands in the CD spectrum both at lambda approximately 310 and lambda approximately 505 nm. Temperature "melting curves" were derived and characterzed by T(M) values. The T(M) values at lambda approximately 310 and lambda approximately 505 nm coincided with each other but differed from the T(M) value characteristic of the DNA cholesteric liquid crystalline dispersion.

[The formation of nanoconstructions based on double-stranded DNA molecules].

The properties of nanoconstructions formed by double-stranded DNA molecules fixed in the structure of their liquid crystalline dispersions and cross-linked by nanobridges were described. The dependence of the optical properties of the nanostructures on various factors (DNA concentration, nanobridge components, etc.) was examined.

[Molecular construction (superstructures) with adjustable properties based on double-stranded nucleic acids]. / Molekuliarnye konstruktsii (superstruktury) s reguliruemymi svoistvami na osnove dvukhtsepochechnykh nukleinovykh kislot.

Formation of molecular construction that consists of double-stranded molecules of nucleic acids (or synthetic polynucleotides) located at the distance 30-50 A in the spatial structure of particles of their cholesteric liquidcrystalline dispersion and crosslinked by polymeric chelate bridges is described. The resulting superstructure, which possesses peculiar physicochemical properties, could be used as integral biosensor whose properties depend on temperature, the presence of chemical or biologically active compounds of different nature, etc.

["Bridge" structures between nucleic acid molecules fixed in the structure of a liquid crystal]. / "Mostikovye" struktury mezhdu molekulami nukleinovykh kislot, fiksirovannymi v strukture zhidkogo kristalla.

The binding of daunomycin and copper ions to poly(I).poly(C) molecules fixed in a particle of a liquid-crystalline dispersion was studied. A thermodynamic model of adsorption was developed, which makes it possible to describe the formation of complexes of a particular kind, "bridges" that connect adjacent nucleic acid molecules fixed in a liquid crystal. The bridges represent chelate complexes, which incorporate the molecules of the antibiotic daunomycin and copper ions. Equations describing the dependence of the concentration of these bridges in solution on the concentration of their constituents were derived. The family of dependences of experimental amplitudes of bands in CD spectra typical of "bridge" structures on the concentration of copper ions represents a set of S-shaped curves, and, as the concentration of daunomycin in solution increases, the level of saturation of these curves increases. The analysis of experimental data with the use of this model suggests that the structures of this type compete with daunomycin molecules for the binding sites on poly(I).poly(C). By using this model, the energies of formation of bridge structures were calculated.

[Identification and cloning of peptide synthetase genes of thermostable bacilli using the polymerase chain reaction]. / Identifikatsiia i klonirovanie genov peptidil sintetaz termorezistentnykh batsill pri pomoshchi polimeraznoi tsepnoi reaktsii.

Fourteen thermophilic and thermostable strains of the genus Bacillus were studied. Total DNA was isolated from these strains and used as a template to identify and clone peptide synthetase genes by means of polymerase chain reaction. Amplified DNA fragments were cloned into a phasmid vector, and nucleotide sequences of cloned fragments were determined. Stringent thermophilic strains were shown to lack genetic systems, which are responsible for the synthesis of secondary metabolites and homologous to the known peptide synthetase genes. On the contrary, thermostable strains had peptide synthetases and produced antimicrobial secondary metabolites. Analysis of nucleotide sequences and deduced amino acid sequences of cloned PCR fragments from B. licheniformis strains VK2, VK21, and VK2101 showed that they are absolutely identical. The cloned DNA fragment was found to be a portion of the open reading frame, which we termed ORF1. Data from analysis of a partial nucleotide sequence of the peptide synthetase gene of strain VK21 indicated that a 9.5-kb region of chromosomal DNA contains sequences of two genes homologous to the B. subtilis peptide synthetase genes dhbB and dhbF. Strains VK2, VK21, and VK2101 were shown to synthesize siderophores. A method for screening bacteria with peptide synthetase genes has been developed.

A novel type of microscopic size chip based on double-stranded nucleic acids.

The double-stranded molecules of nucleic acids (NA) of B- and A-families fixed in the structure of cholesteric liquid-crystalline dispersions, formed as a result of phase exclusion of these molecules from polymer-containing solution, have been used as 'building blocks' for the molecular design. Using the formation of polymeric chelate bridges between NA molecules, three-dimensional structures consisting of alternating NA, anthracycline and copper ions, were created. The formation of the polymeric chelate bridges allows one to stabilize the initial spatial mode of ordering of neighboring NA molecules in a form of so-called 'molecular constructions', immobilize these constructions onto supporting film and evaluate their sizes and shape. The creation of NA molecular constructions is accompanied by an 'extra-increase' in the amplitude of the bands in the CD spectra, despite the initial sense of cholesteric twisting characteristic of liquid-crystalline dispersions. Destroying of polymeric chelate bridges between NA molecules by action of biologically relevant compounds results in disintegration of NA liquid-crystalline molecular constructions. Three-dimensional NA molecular construction can be used as a microscopic size multifunctional chemical unit (chip) for biological or chemical needs.

Protein V, a novel type-II IgG receptor from Streptococcus sp.: sequence, homologies and putative Fc-binding site.

We have cloned and sequenced the Fc-receptor-encoding gene, fcrV, from a group G streptococcus. Considerable similarity was revealed between the FcRV, FcRA76 and M proteins of group A streptococci in their signal sequences and 3' termini, and between the Fc-binding regions of FcRV and FcRA76. The promoter and terminator regions showed no homology with those of the fcrA76 and M protein-encoding genes. The A1-A4 domains of FcrV (protein V) exhibit a heptapeptide repeat motif which is characteristic of alpha-helical coiled-coil proteins. The sequence, Ser-Asn-Arg-Ala-Ala, in the outer position, 'f' of each domain is highly conserved and may be involved in FcR-IgG interactions.

[Effect of neural regulation on the fluctuations in the intervals between cardiac contractions and the force of the contractions]. / Vliianie nervnoi reguliatsii na kolebaniia intervalov mezhdu serdechnymi sokrashcheniiami i sily sokrashchenii.

Statistical analysis of the cardiac rhythm according to the R--R intervals and the force of contractions according to their amplitude was undertaken. The variation coefficient (N%) reflecting the degree of irregularity of intervals between the contractions and the force of contractions during maximum cardiac hyperfunction induced by clamping the aorta for 30 sec was determined. Vagotomy led to a decrease in the irregularity for cardiac rhythm and force of cardiac contractions.

[Interaction of connective tissue structural glycoprotein with proteoglycans and glycosaminoglycans]. / Vzaimodeistvie strukturnogo glikoprotein soedinitel'noi tkani s proteoglikanami i glikozaminoglikanami

It was shown that structural glycoprotein (SGP) of connective tissue isolated from be cattle heart valves and nasal septum cartilage formed water-soluble complexes with protein-chondroitin-4-sulphate and different heparin fractions. SGP formed no mentioned complexes with hyaluronic acid. Probably this plays an important role in the formation of collagen and elastin fibers.