Autoimmunity, immunodeficiency and mucosal infections: chronic intestinal inflammation as a sensitive indicator of immunoregulatory defects in response to normal luminal microflora

Despite the fact that target antigens and the genetic basis of several autoimmune diseases are now better understood, the initial events leading to a loss of tolerance towards self-components remain unknown. One of the most attractive explanations for autoimmune phenomena involves various infections as possible natural events capable of initiating the process in genetically predisposed individuals. The most accepted explanation of how infection causes autoimmunity is based on the concept of "molecular mimicry" (similarity between the epitopes of an autoantigen and the epitopes in the environmental antigen). Infectious stimuli may also participate in the development of autoimmunity by inducing an increased expression of stress proteins (hsp), chaperones and transplantation antigens, which leads to abnormal processing and presentation of self antigens. Superantigens are considered to be one of the most effective bacterial components to induce inflammatory reactions and to take part in the development and course of autoimmune mechanisms. It has long been known that defects in the host defense mechanism render the individual susceptible to infections caused by certain microorganisms. Impaired exclusion of microbial antigens can lead to chronic immunological activation which can affect the tolerance to self components. Defects in certain components of the immune system are associated with a higher risk of a development of autoimmune disease. The use of animal models for the studies of human diseases with immunological pathogenesis has provided new insights into the influence of immunoregulatory factors and the lymphocyte subsets involved in the development of disease. One of the most striking conclusion arising from work with genetically engineered immunodeficient mouse models is the existence of a high level of redundancy of the components of the immune system. However, when genes encoding molecules involved in T cell immunoregulatory functions are deleted, spontaneous chronic inflammation of the gut mucosa (similar to human inflammatory bowel disease) develops. Surprisingly, when such immunocompromised animals were placed into germfree environment, intestinal inflammation did not develop. Impairment of the mucosal immune response to the normal bacterial flora has been proposed to play a crucial role in the pathogenesis of chronic intestinal inflammation. The use of immunodeficient models colonized with defined microflora for the analysis of immune reactivity will shed light on the mode of action of different immunologically important molecules responsible for the delicate balance between luminal commensals, nonspecific and specific components of the mucosal immune system.     

Stabilization of optical characteristics of DNA cholesteric liquid-crystalline dispersions

Abnormal optical properties of liquid-crystalline dispersions (phases) formed as a result of phase exclusion of double-stranded DNA and RNA from water-salt poly(ethylene glycol) solutions and X-ray parameters of these phases are compared. It is shown that the cholesteric packing of nucleic acid molecules is realized at the certain osmotic pressure of a solvent only. A comparison of the optical properties of liquid-crystalline phases (dispersions) to their X-ray parameters allows one to put forward a suggestion on various hydratation (fluctuation) regimes of the nucleic acid behaviour under the condensed phases formation and factors, influencing the mode of packing of these molecules in phases formed. It is shown as well, that immobilization of DNA cholesteric liquid-crystalline particles in the content of polymeric matrix is accompanied by the stabilization of these particles and, hence, their specific abnormal optical activity as well as by formation of particles having a structure, which corresponds to the "optically isotropic ordered liquid" without abnormal optical activity. Data on stabilization of the cholesteric structure of liquid-crystalline DNA dispersions by creation of polymeric chelate bridges between the neighbouring DNA molecules, fixed in the structure of liquid-crystalline dispersions, are shown.     

How evolution makes proteins fold quickly

Sequences of fast-folding model proteins (48 residues long on a cubic lattice) were generated by an evolution-like selection toward fast folding. We find that fast-folding proteins exhibit a specific folding mechanism in which all transition state conformations share a smaller subset of common contacts (folding nucleus). Acceleration of folding was accompanied by dramatic strengthening of interactions in the folding nucleus whereas average energy of nonnucleus interactions remained largely unchanged. Furthermore, the residues involved in the nucleus are the most conserved ones within families of evolved sequences. Our results imply that for each protein structure there is a small number of conserved positions that are key determinants of fast folding into that structure. This conjecture was tested on two protein superfamilies: the first having the classical monophosphate binding fold (CMBF; 98 families) and the second having type-III repeat fold (47 families). For each superfamily, we discovered a few positions that exhibit very strong and statistically significant "conservatism of conservatism"-amino acids in those positions are conserved within every family whereas the actual types of amino acids varied from family to family. Those amino acids are in spatial contact with each other. The experimental data of Serrano and coworkers [Lopez-Hernandez, E. & Serrano, L. (1996) Fold. Des. (London) 1, 43-55]. for one of the proteins of the CMBF superfamily (CheY) show that residues identified this way indeed belong to the folding nucleus. Further analysis revealed deep connections between nucleation in CMBF proteins and their function.     

The sorption of poliovirus type 2 by a carbon sorbent

Materials are presented concerning the study of a possibility to use highly active carbon sorbent "Dnepr-MH" to liberate the tape water from enteroviruses. Investigations were carried out on the model of the vaccine strain of type-II poliovirus. The sorbent samples, most active in respect of the virus sorption and differing by benzene capacity, were determined. Optimal concentration of a sorbent has been established, pH and water temperature were chosen under which the sorption processes are more active. High efficiency of tape water deprive of enterovirus pollution with the help of the above sorbent is demonstrated in the experiment.     

The individual ergodic theorem on the IF-events with product

The ergodic theory and particularly the individual ergodic theorem were studied in many structures. Recently the individual ergodic theorem has been proved for MV-algebras of fuzzy sets (Riečan in Czech Math J 50(125):673–680, 2000; Riečan and Neubrunn in Integral, measure, and ordering. Kluwer, Dordrecht, 1997) and even in general MV-algebras (Jurečková in Int J Theor Phys 39:757–764, 2000). The notion of almost everywhere equality of observables was introduced by Riečan and Jurečková (Int J Theor Phys 44:1587–1597, 2005). They proved that the limit of Cesaro means is an invariant observable for P-observables. In Lendelová (Int J Theor Phys 45(5):915–923, 2006c) showed that the assumption of P-observable can be omitted. In this paper we prove the individual ergodic theorem on family of IF-events and show that each P {\mathcal{P}} -preserving transformation in this family can be expressed by two corresponding P^\flat,P^\sharp {\mathcal{P}}^\flat,{\mathcal{P}}^\sharp -preserving transformations in tribe T. {\mathcal{T}}.     

Control of the angular orientation of the platform of a uniaxial wheeled module moving without slippage over an underlying surface

A method for controlling the angular orientation with respect to the horizon plane of the platform of a uniaxial wheeled module moving without slippage over the underlying surface is considered. For a module involving a one-axis gyroscope, a compensating flywheel, and a stabilizing weight, equations of motion are derived, which describe the module as a nonholonomic system due to the absence of slippage of its wheels over the underlying surface. The conditions for the “force of undisturbability” of the platform by the inertial forces upon its arbitrary translational-rotational motion and the conditions for “informational undisturbability” by the inertial forces of the accelometric sensor of the deviation of the platform from the horizon plane are determined. The analytical relationships determining the conditions for the absence of slippage of the wheels are found. By numerical simulation, rational values of the coefficient in the laws governing the moments of forces developed by the control elements of the structure are obtained. The effectiveness of these laws is confirmed by the results of simulating the control processes over the angular motion of the platform of the module along a typical trajectory of its motion over the underlying surface.     

Neuromuscular disorders in thyroid gland diseases

To establish the basis of the interpretative method is congruous with finding a solid basis--epistemologically speaking--to the analytic theory. This basis would be the means to transform this theory into a real science with its necessary adecuation among method, act and object of knowledge. It is only from a scientific stand that the psychoanalytic theory will be able to face successfully the reductionisms that menace it, be it the biologist-naturalism with its explanations of the psychic phenomena by means of mechanisms and biologic models or be it the speculative ideologies with their nucleus of technical praxis which make it impossible for the social-factic sciences to become real sciences. We propose as interpretative method the union of two models: the teleologic one which makes possible the appearance of intelligible, contingent and variable explanations between an antecedent and a consequent on one side, and on the other, the analogic model with its two moments: the comparative and the symbolic one. These moments makes possible the comparison and the union between antecedent and consequent baring in mind the "natural" ambiguity of the subject-object in question. The principal objective of the method--as a regulative idea in the Kantian sense--would be the search of univocity as regards the choice of one and only one sense from all the possible senses that "explain" the motive relationship or motive-end relationship in order to make the interpretation scientific. This status of scientificity should obey the rules of explanation: that the interpretations be derived effectively from the presupposed theory, that they really explain what they claim to explain, that they are not contradictory or contrary in the same ontologic level. We postulate that the synthesis of the two mentioned models, the teleologic-explanative and the analogic one allows us to find a possibility to make clear the "dark" sense of the noun interpretation and in this way the factibility of speaking of an interpretative method that develops the real concrete object by producing the formal and abstract one--which for us is the behaviour of the subject--. In this way the interpretations come to be teleological explanations overdetermined by an analogical relationship. This means that they produce the formal and abstract object -the method--which is in itself an intelligible, continguent and variable relationship between an antecedent and a consequent permitting in this way the emergence of a symbolic comparison to explain the real concrete. The symbolic explanations and comparisons are strictly derived from the presupposed theory, the theoretical body of psychoanalysis.     

Transport properties of LaSrNi1 − x ScxOy solid solutions

The formation of LaSrNiO₄-and LaSrScO₄-based solid solutions with the general stoichiometry LaSrNi_{1 ? x} Sc_xO₄ (0 < x < 1) has been studied in air at temperatures from 700 to 1300°C. According to x-ray diffraction results, the former solid solutions exist in the composition range 0 < x ≤ 0.2. Their lattice parameters have been determined, and their resistivity and thermoelectric power have been measured as functions of temperature. Oxygen release and absorption measurements at temperatures from 20 to 1000°C and oxygen partial pressures from 2 to 330 Pa suggest that the presence of scandium has a stabilizing effect on the oxygen sublattice of the solid solutions. The possible mechanisms of this effect are discussed.     

The recombination of quasiparticles in x-ray superconducting tunnel detectors

The energy resolution of superconducting tunnel detectors is investigated from the point of view of the effect of recombination and boundary losses of nonequilibrium quasiparticles. Using the x-ray fluorescence method, the dependence of the signal on the energy of x-ray quanta is measured for Ti/Nb/Al/AlO_x/Al/Nb/NbN detectors. The form of the apparatus line is also investigated. The experimental data are analyzed using the diffusion model of tunnel detectors. __________ Translated from Izmeritel’naya Tekhnika, No. 8, pp. 59–64, August, 2006.     

Technical refitting of cogeneration stations on the basis of combined-cycle technologies with the use of a parallel scheme

Results from analyzing different versions of combined-cycle toppings that can be used for technically refitting the TETs-23 cogeneration station are presented. Changes in the operating conditions of the turbine and boiler are investigated, thermal schemes are developed, and questions concerning the placement of new equipment on the old site are considered. An approach to evaluating the effect from refitting the cogeneration station is proposed that uses parameters calculated per unit of the additional power obtained during the refitting.