Magnetic structure and phase diagram of TmB4

Magnetic structure of single crystalline TmB4 has been studied by magnetization, magnetoresistivity and specific heat measurements. A complex phase diagram with different antiferromagnetic (AF) phases was observed below TN1 = 11.7 K. Besides the plateau at half-saturated magnetization (1/2 MS), also plateaus at 1/9, 1/8 and 1/7 of MS were observed as function of applied magnetic field B//c. From additional neutron scattering experiments on TmB4, we suppose that those plateaus arise from a stripe structure which appears to be coherent domain boundaries between AF ordered blocks of 7 or 9 lattice constants. The received results suggest that the frustration among the Tm3+ magnetic ions, which maps to a geometrically frustrated Shastry-Sutherland lattice lead to strong competition between AF and ferromagnetic (FM) order. Thus, stripe structures in intermediate field appear to be the best way to minimize the magnetostatic energy against other magnetic interactions between the Tm ions combined with very strong Ising anisotropy.Comment: 4 pages, 4 figures, conference contribution - CSMAG 0

MEASURES FOR NON-PERMITTING OF DELIVERY AND SPREADING OF SEVERE ACUTE RESPIRATORY SYNDROME TO ALTAI TERRITORY

Despite of available conditions for the delivery of «atypical pneumonia» to Altai Territory, the complex of conducted measures allowed to prevent the cases of SARS. The measures included recommendations for limited travels to the countries with registered cases of SARS, setting the sanitary-control points to increased readiness, theoretical training of medical staff, strengthening of the desinfection regimen, putting wide sanitary education among the population

Электромагнитные поля компактных люминесцентных энергосберегающих ламп

The questions related to potential environmental and hygienic hazard, which may be caused by electromagnetic field of compact energy saving lamps, are considered. The results of measurements of electromagnetic fields in low frequency domain: spectral composition, intensity depending on distance for lamps of various types and power consumption are presented. It is shown that maximum value of electromagnetic field frequency of 50 Hz from the measured energy saving lamps does not exceed the maximum permissible levels.Рассматриваются вопросы, связанные с возможной эколого-гигиенической опасностью, которые могут представлять электромагнитные поля компактных энергосберегающих ламп. Приведенырезультаты измерений электромагнитных полей в низкочастотной области: спектрального состава, напряженности в зависимости от расстояния для ламп различных видов и потребляемой мощности. Показано, что максимальные величины напряженности электромагнитного поля частотой 50 Гц от измеренных энергосберегающих ламп не превышают предельно допустимых уровней

Formation of Amyloid-Like Fibrils by Y-Box Binding Protein 1 (YB-1) Is Mediated by Its Cold Shock Domain and Modulated by Disordered Terminal Domains

YB-1, a multifunctional DNA- and RNA-binding nucleocytoplasmic protein, is involved in the majority of DNA- and mRNA-dependent events in the cell. It consists of three structurally different domains: its central cold shock domain has the structure of a β-barrel, while the flanking domains are predicted to be intrinsically disordered. Recently, we showed that YB-1 is capable of forming elongated fibrils under high ionic strength conditions. Here we report that it is the cold shock domain that is responsible for formation of YB-1 fibrils, while the terminal domains differentially modulate this process depending on salt conditions. We demonstrate that YB-1 fibrils have amyloid-like features, including affinity for specific dyes and a typical X-ray diffraction pattern, and that in contrast to most of amyloids, they disassemble under nearly physiological conditions

Features of mitochondrial membrane potential of immunocompetent blood cells in children with chronic nonspecific lung diseases accompanied by pneumofibrosis

Pneumofibrosis is a pathological outcome of pulmonary tissue inflammation. It can complicate any lung and bronchial disorder. The mitochondrial membrane potential reflects functional state of immunocompetent blood cells that influence progression of a chronic inflammatory process. The aim of this work was to study the features of mitochondrial membrane potential (MMP) of immunocompetent blood cells in children with chronic nonspecific lung diseases (CNPD), accompanied by pneumofibrosis. We have examined 79 children with CNPD manifesting with symptoms of focal pneumofibrosis. The group of patients included children with congenital lung malformations (43%), consequences of bronchopulmonary dysplasia (41%), chronic bronchitis (10%), post-pneumonic pulmonary fibrosis (6%). The average age of children was 6.5±1.2 years, including 43 boys (54%) and 36 girls (46%). The comparison group included 46 children with COPD without signs of pulmonary fibrosis, the control group consisted of 30 apparently healthy children. The contents of cells with reduced MMP among lymphocytes, monocytes, and granulocytes in peripheral blood was determined with JC-1 dye, using the BD FACSCalibur instrument and Cell Quest Pro software (Becton Dickinson, USA). The proportion of lymphocytes with reduced MMP in patients with COPD was similar in the children of the main and comparison group, exceeding the indexes of the control group by 1.7 times (p < 0.001). Decreased MMP of granulocytes in children with pneumofibrosis was detected 1.9 times more often than in children with fibrosis-free CNPD cases (p < 0.05), and 3.4 times more common than in children from the control group (p < 0.001). Monocytes with reduced MMM in children with pulmonary fibrosis were detected 2 times more often than in children with COPD without fibrosis (p < 0.05), and 7.3 times more frequent than in the control group (p < 0.001). The changes were more expressed in children during exacerbation of the disease. The revealed features suggest a decreased level of metabolic activity of blood cells, thus, probably, presenting an immunopathogenetic basis for development of pneumofibrosis

Molecular Composition of Staufen2-Containing Ribonucleoproteins in Embryonic Rat Brain

Messenger ribonucleoprotein particles (mRNPs) are used to transport mRNAs along neuronal dendrites to their site of translation. Numerous mRNA-binding and regulatory proteins within mRNPs finely regulate the fate of bound-mRNAs. Their specific combination defines different types of mRNPs that in turn are related to specific synaptic functions. One of these mRNA-binding proteins, Staufen2 (Stau2), was shown to transport dendritic mRNAs along microtubules. Its knockdown expression in neurons was shown to change spine morphology and synaptic functions. To further understand the molecular mechanisms by which Stau2 modulates synaptic function in neurons, it is important to identify and characterize protein co-factors that regulate the fate of Stau2-containing mRNPs. To this end, a proteomic approach was used to identify co-immunoprecipitated proteins in Staufen2-containing mRNPs isolated from embryonic rat brains. The proteomic approach identified mRNA-binding proteins (PABPC1, hnRNP H1, YB1 and hsc70), proteins of the cytoskeleton (α- and β-tubulin) and RUFY3 a poorly characterized protein. While PABPC1 and YB1 associate with Stau2-containing mRNPs through RNAs, hsc70 is directly bound to Stau2 and this interaction is regulated by ATP. PABPC1 and YB1 proteins formed puncta in dendrites of embryonic rat hippocampal neurons. However, they poorly co-localized with Stau2 in the large dendritic complexes suggesting that they are rather components of Stau2-containing mRNA particles. All together, these results represent a further step in the characterization of Stau2-containing mRNPs in neurons and provide new tools to study and understand how Stau2-containing mRNPs are transported, translationally silenced during transport and/or locally expressed according to cell needs

Suppression of Her2/neu expression through ILK inhibition is regulated by a pathway involving TWIST and YB-1

In a previous study it was found that the therapeutic effects of QLT0267, a small molecule inhibitor of integrin-linked kinase (ILK), were influenced by Her2/neu expression. To understand how inhibition or silencing of ILK influences Her2/neu expression, Her2/neu signaling was evaluated in six Her2/neu-positive breast cancer cell lines (LCC6Her2, MCF7Her2, SKBR3, BT474, JIMT-1 and KPL-4). Treatment with QLT0267 engendered suppression (32–87%) of total Her2/neu protein in these cells. Suppression of Her2/neu was also observed following small interfering RNA-mediated silencing of ILK expression. Time course studies suggest that ILK inhibition or silencing caused transient decreases in P-AKTser473, which were not temporally related to Her2/neu downregulation. Attenuation of ILK activity or expression was, however, associated with decreases in YB-1 (Y-box binding protein-1) protein and transcript levels. YB-1 is a known transcriptional regulator of Her2/neu expression, and in this study it is demonstrated that inhibition of ILK activity using QLT0267 decreased YB-1 promoter activity by 50.6%. ILK inhibition was associated with changes in YB-1 localization, as reflected by localization of cytoplasmic YB-1 into stress granules. ILK inhibition also suppressed TWIST (a regulator of YB-1 expression) protein expression. To confirm the role of ILK on YB-1 and TWIST, cells were engineered to overexpress ILK. This was associated with a fourfold increase in the level of YB-1 in the nucleus, and a 2- and 1.5-fold increase in TWIST and Her2/neu protein levels, respectively. Taken together, these data indicate that ILK regulates the expression of Her2/neu through TWIST and YB-1, lending support to the use of ILK inhibitors in the treatment of aggressive Her2/neu-positive tumors

Identification of Y-Box Binding Protein 1 As a Core Regulator of MEK/ERK Pathway-Dependent Gene Signatures in Colorectal Cancer Cells

Transcriptional signatures are an indispensible source of correlative information on disease-related molecular alterations on a genome-wide level. Numerous candidate genes involved in disease and in factors of predictive, as well as of prognostic, value have been deduced from such molecular portraits, e.g. in cancer. However, mechanistic insights into the regulatory principles governing global transcriptional changes are lagging behind extensive compilations of deregulated genes. To identify regulators of transcriptome alterations, we used an integrated approach combining transcriptional profiling of colorectal cancer cell lines treated with inhibitors targeting the receptor tyrosine kinase (RTK)/RAS/mitogen-activated protein kinase pathway, computational prediction of regulatory elements in promoters of co-regulated genes, chromatin-based and functional cellular assays. We identified commonly co-regulated, proliferation-associated target genes that respond to the MAPK pathway. We recognized E2F and NFY transcription factor binding sites as prevalent motifs in those pathway-responsive genes and confirmed the predicted regulatory role of Y-box binding protein 1 (YBX1) by reporter gene, gel shift, and chromatin immunoprecipitation assays. We also validated the MAPK-dependent gene signature in colorectal cancers and provided evidence for the association of YBX1 with poor prognosis in colorectal cancer patients. This suggests that MEK/ERK-dependent, YBX1-regulated target genes are involved in executing malignant properties