Publications by authors named "Karavanov A"

A hundred and ninety-one patients who had fallen ill with tick-borne encephalitis (TBE) after bites by virus-carrying ticks were examined to reveal the characteristics of antibody production of the major classes of immunoglobulins (IgM and IgG) against structural protein E of the TBE virus and nonstructural protein NS1 of the TBE viral replicative complex in the natural history of an infectious process in different forms and variants of the disease. In the two-wave course of TBE, the infectious process is characterized by a delayed antibody production, lower levels of specific antibodies against virion protein E in the acute phase of disease during the first wave of fever. The development of meningocerebral syndromes at the peak of the second fever wave is observed in patients with the delayed accumulation and low levels of IgG antibodies.

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Protein array technologies refer to any fabrication and use of any arrays containing multiple proteins captured on solid surfaces. This valuable tool is used for high-throughput protein-protein interaction studies, protein marker discovery and other applications. This unit provides basic protocols for biomarker discovery and protein-protein interactions.

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We have induced a polyclonal IgG that degrades the HIV-1 surface antigen, glycoprotein gp120, by taking advantage of the susceptibility of SJL mice to a peptide-induced autoimmune disorder, experimental autoimmune encephalomyelitis (EAE). Specific pathogen-free SJL mice were immunized with structural fragments of gp120, fused in-frame with encephalitogenic peptide MBP(85-101). It has resulted in a pronounced disease-associated immune response against antigens.

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Autoantibody-mediated tissue destruction is among the main features of organ-specific autoimmunity. This report describes "an antibody enzyme" (abzyme) contribution to the site-specific degradation of a neural antigen. We detected proteolytic activity toward myelin basic protein (MBP) in the fraction of antibodies purified from the sera of humans with multiple sclerosis (MS) and mice with induced experimental allergic encephalomyelitis.

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The 70-kDa heat shock protein (Hsp) family in all Drosophila species includes 2 environmentally inducible family members, Hsp70 and Hsp68. Two-dimensional gel electrophoresis revealed an unusual pattern of heat shock-inducible proteins in the species of the virilis group. Trypsin fingerprinting and microsequencing of tryptic peptides using ProteinChip Array technology identified the major isoelectric variants of Hsp70 family, including Hsp68 isoforms that differ in both molecular mass and isoelectric point from those in Drosophila melanogaster.

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Peptide nucleic acids (PNAs) bind tightly and sequence-specifically to single- and double-stranded nucleic acids, and are hence of interest in the design of gene-targeted radiotherapeutics that could deliver the radiodamage to designated DNA and/or RNA sites. As a first step towards this goal, we developed a procedure for incorporation of Auger electron-emitting radionuclide (indium-111) into PNA oligomers and studied the efficiency of PNA-directed cleavage of single-stranded DNA targets. Accordingly, diethylene triamine penta-acetic acid (DTPA) was conjugated to the lysine-appended mixed-base PNAs and sequence-homologous DNA oligomer with a proper linker for comparative studies.

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The composition of RNase H2 has been a long-standing problem. Whereas bacterial and archaeal RNases H2 are active as single polypeptides, the Saccharomyces cerevisiae homolog, Rnh2Ap, when expressed in Escherichia coli, fails to produce an active RNase H2. By affinity chromatography purification and identification of polypeptides associated with a tagged S.

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Antigenic structure of tick-borne encephalitis virus proteins was studied by ELISA with monoclonal antibodies (MAb) to E and NS1 glycoproteins of strain Sofyin. Envelope proteins appeared to be conservative which corresponded to previously determined nucleotide sequences of E gene fragments and deduced primary structures of the corresponding E protein. Five of six studied MAb to NS1 nonstructural glycoprotein of strain Sofyin reacted with this protein of all studied strains.

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Fibroblast growth factor-binding protein (FGF-BP) 1 is a secreted protein that can bind fibroblast growth factors (FGFs) 1 and 2. These FGFs are typically stored on heparan sulfate proteoglycans in the extracellular matrix in an inactive form, and it has been proposed that FGF-BP1 functions as a chaperone molecule that can mobilize locally stored FGF and present the growth factor to its tyrosine kinase receptor. FGF-BP1 is up-regulated in squamous cell, colon, and breast cancers and can act as an angiogenic switch during malignant progression of epithelial cells.

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We assessed the risk for human tick-borne encephalitis (TBE), ixodid tick-borne borrelioses, and double infection from 1994 to 1998 in Perm, which has among the highest rates of reported cases in Russia. We studied 3,473 unfed adult Ixodes persulcatus ticks collected from vegetation in natural foci and 62,816 ticks removed from humans. TBE virus and Borrelia may coexist in ticks.

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The Spemann-Mangold organizer is required in amphibian embryos to coordinate cell fate specification, differentiation of dorsal cell types and morphogenetic movements at early stages of development. A great number of genes are specifically expressed within the organizer, most of them encoding secreted proteins and transcription factors. The challenge is now to uncover genetic cascades and networks of interactions between these genes, in order to understand how the organizer functions.

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Pleiotrophin (PTN) is a secreted growth factor that induces neurite outgrowth and is mitogenic for fibroblasts, epithelial, and endothelial cells. During tumor growth PTN can serve as an angiogenic factor and drive tumor invasion and metastasis. To identify a receptor for PTN, we panned a phage display human cDNA library against immobilized PTN protein as a bait.

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Samples that are periodically withdrawn from the mixture of a conjugation reaction can be analyzed on a picomolar scale without any work-up or pre-purification using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) in combination with the ProteinChip System. The technique provides rapid information about the increasing molecular mass of the glycoconjugate formed, thereby allowing termination of the process when the desired incorporation of the ligand onto the carrier protein is achieved. The excess oligosaccharide used at the onset of conjugation can be recovered and used in preparation of a similar neoglycoconjugate.

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Tick-borne encephalitis virus (TBEV) strains were isolated from ticks in Western Siberia for 12 years. Molecular hybridization of the 46 viral RNA with the TBEV cDNA and oligonucleotide probes revealed differences between the Siberian and Far Eastern strains. A comparison of the viral E gene fragment nucleotide sequence showed 89-98% homology between Siberian TBEV strains, whereas their similarity with strains from other populations was less than 83%.

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The homeobox genes Xlim-1 and goosecoid (gsc) are coexpressed in the Spemann organizer and later in the prechordal plate that acts as head organizer. Based on our previous finding that gsc is a possible target gene for Xlim-1, we studied the regulation of gsc transcription by Xlim-1 and other regulatory genes expressed at gastrula stages, by using gsc-luciferase reporter constructs injected into animal explants. A 492-bp upstream region of the gsc promoter responds to Xlim-1/3m, an activated form of Xlim-1, and to a combination of wild-type Xlim-1 and Ldb1, a LIM domain binding protein, supporting the view that gsc is a direct target of Xlim-1.

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The word deals with the results obtained in the study of the reactogenicity and immunological activity of concentrated and inactivated tissue-culture tick-borne encephalitis vaccine, manufactured by the Chumakov Institute of Poliomyelitis and Viral Encephalitides, in the immunization of children and adolescents. The vaccine proved to be moderately reactogenic and exhibited pronounced immunological activity. In 91.

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To investigate the relationships between tick-borne encephalitis (TBE) virus and the bacterial spirochaete Borrelia burgdorferi sensu lato in vectors with mixed infections, unfed adult Ixodes persulcatus ticks were collected by flagging from vegetation in southern-taiga forests of the Pre-Urals region of Russia where both infections circulate sympatrically. Prevalences of TBE and Borrelia infections in a total of 4234 ticks were compared over 5 years. No significant differences were revealed between the prevalence of Borrelia infection in ticks with and without TBE virus (29.

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A number of peptides, fragments of the envelope protein E of the tick-borne encephalitis virus (Sofjin strain), were synthesized. Their binding to the polyclonal antiserum to protein E was studied. Rats were immunized with both the free peptides and their KLH-conjugates, and the resulting antisera were tested for their reactivity toward protein E and for their neutralizing activity toward the virus in cell culture.

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The circuits that control movement are comprised of discrete subtypes of motor neurons. How motor neuron subclasses develop and extend axons to their correct targets is still poorly understood. We show that LIM homeodomain factors Lhx3 and Lhx4 are expressed transiently in motor neurons whose axons emerge ventrally from the neural tube (v-MN).

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Hybridomas secreting monoclonal antibodies (Mab) to tick-borne encephalitis (TBE) virus are obtained. Immunodiffusion showed that 3 Mabs to TBE protein NS3 belong to class IgM and the rest to IgG1. Mabs to TBE protein NS1 were tested in hemagglutination inhibition, complement fixation, neutralization, and protection tests.

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This study describes an in situ hybridization and immunohistochemical analysis of Lim-1 homeobox gene expression during kidney development in the rat. Lim-1 is expressed at all stages of mesonephric and metanephric kidney development. In the metanephros, Lim-1 gene mRNA is first found at day 13 in the ureteric bud, but not in uninduced mesenchyme.

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LIM class homeobox genes code for a family of transcriptional regulators that encode important determinants of cell lineage and cell type specificity. The lim3 gene from the zebrafish, Danio rerio, is highly conserved in sequence and expression pattern compared to its homologs in other vertebrates. In this paper we report immunocytochemical analysis of Lim3 protein expression in the pituitary, pineal, hindbrain, and spinal cord of the embryo, revealing an asymmetrical, lateral and late program of pituitary development in zebrafish, distinct from the pattern in other vertebrates.

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To analyze the roles of neurotrophins during early development of rat teeth, we studied the expression of neurotrophin mRNAs from the initiation of first molar formation to the completion of crown morphogenesis. With RNAase protection assay all neurotrophin mRNAs were detected in embryonic teeth. In situ hybridization analysis revealed developmentally changing, distinct expression patterns for nerve growth factor (NGF) and neurotrophin-3 (NT-3), which were shown not to be regulated by or dependent on peripheral innervation.

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