Various characteristics of the structure and synthesis of procollagens produced by cultured skin fibroblasts from patients with Danlos-Ehlers syndrome type I

The electrophoretic mobilities of the collagen and procollagen type I and III chains synthesized by the fibroblasts isolated from patients with type I Ehlers-Danlos syndrome as well as a set of peptides obtained by splitting of pro alpha 1(I) and pro alpha 2(I) type I procollagens by cyanbromide are not different from the normal ones. The fact demonstrates the absence of long insertions or deletions, or the sufficient defects in intracellular chain modifications. The changes were also nor registered for the ratio of type I and III collagens from the digested by pepsin preparations of protein accumulating in the culture media of the cultured skin fibroblasts from patients. The studied strains of cultured fibroblasts from patients suffering the Ehlers-Danlos syndrome have the trend to increased accumulation of partially processed chains of proc alpha 1(I) and proc alpha 2(I) type I procollagen and to the increased ratio of pro alpha 1(I) to pro alpha 2(I).     

Phagocytosis of Burkholderia mallei as a criterion for immunogenicity evaluation of its capsular antigens

Test-system using index of phagocytosis of noncapsulated mutant loaded by one of the several capsular antigenic complexes was developed and used for screening for both immunogenic and protective capsular antigens of B. mallei. Direct correlation between index of phagocytosis, level of delayed-type hypersensivity, and protective effect of capsular antigens has been shown on the model of experimental melioidosis in susceptible white mice, guinea pigs and white rats. Obtained results let to use the developed test-system for initial selection of B. mallei protective capsular antigens and their further study as potential components of preparations for specific prophylaxis of glanders and melioidosis.     

Some properties of plasmocoagulase of the causative agents of glanders and melioidosis

Criteria for the evaluation of the plasmocoagulase activity of natural isolates and mutant strains of the causative agents of glanders and melioidosis were worked out, which made it possible to subdivide them by this sign into pathogens with high, moderate and low activity. Plasmocoagulase produced by pathogenic Burkholderia was shown to be a thermolabile enzyme, comparatively stable with respect to the action of such chemico-biological agents as hydrogen peroxide and chloramine.     

Normal polymorphism of the (CTG)n repeat in the myotonin protein kinase (DM) gene on chromosome 19q13.3 in Western European populations

Polymorphism of a highly polymorphic CTG repeat in the 3'-untranslated region of the myotonin protein kinase gene was analyzed in healthy people from several Eastern European populations (Russians, Moldovans, Belarussians, Komis, Chuvashes, Udmurts, Bashkirs, Tatars, Maris, and Mordovians). In total, 26 alleles of the CTG repeat were found, the repeat number ranging from 5 to 33 (alleles with six and seven repeats were not detected). The heterozygosity of individual populations varied from 61 to 91%. In the total sample combining all populations, the observed and expected heterozygosities did not differ (fixation index -0.0022) suggesting selective neutrality of the normal polymorphism of the CTG repeat in the myotonin protein kinase gene.     

Local cerebral blood flow, cortical impedance, cerebral intravascular kinin production during forebrain ischemia and reperfusion in rats

In the rat model of forebrain ischemia with subsequent reperfusion, an obvious formation of intravascular kinin (IVKF) occurred. The IVKF preceded and coincided in time with the maximum hyperemia and a vasogenic oedema. Local cerebral blood flow (LCBF) increased up to about 187%, at that. In three groups of experimental rats, a correlation was revealed among the ischemia obviousness, IVKF, and development of the brain oedema.     

Immunogenicity of surface and capsular antigens of Burkholderia

Study showed that five (C3, C6, C9, C10, C11) out of ten chromatographic fractions of surface and capsular antigens of B. mallei significantly stimulated cell-mediated immunity that manifested in activation of delayed hypersensivity reactions (DHS) and phagocyteability of noncapsulated avirulent strain of B. mallei with added surface and capsular antigenic complexes. Other fractions did not stimulate cell-mediated immunity, furthermore, fraction C8, which contained capsular biopolymer with mass of 200 kD (Ar8), was characterized by immunosuppressive effect on DHS and phagocytosis. Observed stimulation of cell-mediated immunity by fractions referred above has been confirmed by assessment of their protective effects on the model of experimental melioidosis in white rats. Relationship between markers of humoral and cell-mediated immunity, including markers of specific response, was not observed.     

Comparative assessment of DNA extraction methods for identification of glanders and melioidosis etiological agents by PCR

Pathogenic Burkholderia are considered as a cause of dangerous infections and potential agents of bioterrorism. Comparative assessment of different methods of extraction and purification of DNA for PCR analysis of pure cultures and samples contaminated by etiological agents of glanders and melioidosis was performed. Samples of soil and food artificially contaminated by pathogenic Burkholderia as well as organs of infected animals were tested. DNA was extracted by methods of boiling, nucleosorption with presence of guanidine thiocyanate, guanidine thiocyanatephenol extraction, guanidine thiocyanate-phenol extraction with additional purification of DNA by nucleosorption. Amplification was performed by "Flash" technique and detector of fluorescence was used for analysis of PCR products. Utilization of the recommended methods of preparation depending on the nature of sample let to detect by the "Flash" technique the etiological agents of glanders and melioidosis in concentration =10(3) microbial cells per ml. Choice of DNA extraction and purification methods is determined by type of a sample and presence in it of admixtures inhibiting PCR.     

Recurrent patterns of DNA copy number alterations in tumors reflect metabolic selection pressures

Copy number alteration (CNA) profiling of human tumors has revealed recurrent patterns of DNA amplifications and deletions across diverse cancer types. These patterns are suggestive of conserved selection pressures during tumor evolution but cannot be fully explained by known oncogenes and tumor suppressor genes. Using a pan‐cancer analysis of CNA data from patient tumors and experimental systems, here we show that principal component analysis‐defined CNA signatures are predictive of glycolytic phenotypes, including ¹⁸F‐fluorodeoxy‐glucose (FDG) avidity of patient tumors, and increased proliferation. The primary CNA signature is enriched for p53 mutations and is associated with glycolysis through coordinate amplification of glycolytic genes and other cancer‐linked metabolic enzymes. A pan‐cancer and cross‐species comparison of CNAs highlighted 26 consistently altered DNA regions, containing 11 enzymes in the glycolysis pathway in addition to known cancer‐driving genes. Furthermore, exogenous expression of hexokinase and enolase enzymes in an experimental immortalization system altered the subsequent copy number status of the corresponding endogenous loci, supporting the hypothesis that these metabolic genes act as drivers within the conserved CNA amplification regions. Taken together, these results demonstrate that metabolic stress acts as a selective pressure underlying the recurrent CNAs observed in human tumors, and further cast genomic instability as an enabling event in tumorigenesis and metabolic evolution.