排序方式: 共有73条查询结果,搜索用时 15 毫秒
41.
GV Pavlova AA Vergun EY Rybalkina PR Butovskaya AP Ryskov 《Cell cycle (Georgetown, Tex.)》2015,14(2):200-205
Random amplified polymorphic DNA (RAPD) analysis was adapted for genomic identification of cell cultures and evaluation of DNA stability in cells of different origin at different culture passages. DNA stability was observed in cultures after no more than 5 passages. Adipose-derived stromal cells demonstrated increased DNA instability. RAPD fragments from different cell lines after different number of passages were cloned and sequenced. The chromosomal localization of these fragments was identified and single-nucleotide variations in RAPD fragments isolated from cell lines after 8–12 passages were revealed. Some of them had permanent localization, while most variations demonstrated random distribution and can be considered as de novo mutations. 相似文献
42.
Celia Méndez-García Victoria Mesa Richard R Sprenger Michael Richter María Suárez Diez Jennifer Solano Rafael Bargiela Olga V Golyshina ángel Manteca Juan Luis Ramos José R Gallego Irene Llorente Vitor AP Martins dos Santos Ole N Jensen Ana I Peláez Jesús Sánchez Manuel Ferrer 《The ISME journal》2014,8(6):1259-1274
Macroscopic growths at geographically separated acid mine drainages (AMDs) exhibit distinct populations. Yet, local heterogeneities are poorly understood. To gain novel mechanistic insights into this, we used OMICs tools to profile microbial populations coexisting in a single pyrite gallery AMD (pH ∼2) in three distinct compartments: two from a stratified streamer (uppermost oxic and lowermost anoxic sediment-attached strata) and one from a submerged anoxic non-stratified mat biofilm. The communities colonising pyrite and those in the mature formations appear to be populated by the greatest diversity of bacteria and archaea (including ‘ARMAN'' (archaeal Richmond Mine acidophilic nano-organisms)-related), as compared with the known AMD, with ∼44.9% unclassified sequences. We propose that the thick polymeric matrix may provide a safety shield against the prevailing extreme condition and also a massive carbon source, enabling non-typical acidophiles to develop more easily. Only 1 of 39 species were shared, suggesting a high metabolic heterogeneity in local microenvironments, defined by the O2 concentration, spatial location and biofilm architecture. The suboxic mats, compositionally most similar to each other, are more diverse and active for S, CO2, CH4, fatty acid and lipopolysaccharide metabolism. The oxic stratum of the streamer, displaying a higher diversity of the so-called ‘ARMAN''-related Euryarchaeota, shows a higher expression level of proteins involved in signal transduction, cell growth and N, H2, Fe, aromatic amino acids, sphingolipid and peptidoglycan metabolism. Our study is the first to highlight profound taxonomic and functional shifts in single AMD formations, as well as new microbial species and the importance of H2 in acidic suboxic macroscopic growths. 相似文献
43.
Flávia C Rodrigues-Lisoni Paulo PeitlJr Alessandra Vidotto Giovana M Polachini José V Maniglia Juliana Carmona-Raphe Bianca R Cunha Tiago Henrique Caique F Souza Rodrigo AP Teixeira Erica E Fukuyama Pedro MichaluartJr Marcos B de Carvalho Sonia M Oliani Head Neck Genome Project GENCAPO Eloiza H Tajara 《BMC medical genomics》2010,3(1):14
Background
The development and progression of cancer depend on its genetic characteristics as well as on the interactions with its microenvironment. Understanding these interactions may contribute to diagnostic and prognostic evaluations and to the development of new cancer therapies. Aiming to investigate potential mechanisms by which the tumor microenvironment might contribute to a cancer phenotype, we evaluated soluble paracrine factors produced by stromal and neoplastic cells which may influence proliferation and gene and protein expression.Methods
The study was carried out on the epithelial cancer cell line (Hep-2) and fibroblasts isolated from a primary oral cancer. We combined a conditioned-medium technique with subtraction hybridization approach, quantitative PCR and proteomics, in order to evaluate gene and protein expression influenced by soluble paracrine factors produced by stromal and neoplastic cells.Results
We observed that conditioned medium from fibroblast cultures (FCM) inhibited proliferation and induced apoptosis in Hep-2 cells. In neoplastic cells, 41 genes and 5 proteins exhibited changes in expression levels in response to FCM and, in fibroblasts, 17 genes and 2 proteins showed down-regulation in response to conditioned medium from Hep-2 cells (HCM). Nine genes were selected and the expression results of 6 down-regulated genes (ARID4A, CALR, GNB2L1, RNF10, SQSTM1, USP9X) were validated by real time PCR.Conclusions
A significant and common denominator in the results was the potential induction of signaling changes associated with immune or inflammatory response in the absence of a specific protein.44.
Bruna Daniella Souza Silva Daniela Graner Schuwartz Tannus-Silva Marcelo Fouad Rabahi Andre Kipnis Ana Paula Junqueira-Kipnis 《Memórias do Instituto Oswaldo Cruz》2014,109(1):29-37
Rheumatoid arthritis (RA) is an autoimmune disease characterised by the destruction
of articular cartilage and bone damage. The chronic treatment of RA patients causes a
higher susceptibility to infectious diseases such as tuberculosis (TB); one-third of
the world’s population is latently infected (LTBI) with Mycobacterium
tuberculosis (Mtb). The tuberculin skin test is used to identify
individuals LTBI, but many studies have shown that this test is not suitable for RA
patients. The goal of this work was to test the specific cellular immune responses to
the Mtb malate synthase (GlcB) and heat shock protein X (HspX) antigens of RA
patients and to correlate those responses with LTBI status. The T-helper (Th)1, Th17
and Treg-specific immune responses to the GlcB and HspX Mtb antigens were analysed in
RA patients candidates for tumour necrosis factor-α blocker treatment. Our results
demonstrated that LTBI RA patients had Th1-specific immune responses to GlcB and
HspX. Patients were followed up over two years and 14.3% developed active TB. After
the development of active TB, RA patients had increased numbers of Th17 and Treg
cells, similar to TB patients. These results demonstrate that a GlcB and HspX antigen
assay can be used as a diagnostic test to identify LTBI RA patients. 相似文献
45.
S Çolakoğlu A Aktaş S Raimondo AP Türkmen BZ Altunkaynak E Odacı 《Biotechnic & histochemistry》2014,89(2):136-144
We investigated the effects of diclofenac sodium (DS) on development of the optic nerve in utero. Pregnant female rats were separated into three groups: control, saline treated and DS treated. Offspring of these animals were divided into 4-week-old and 20-week-old groups. At the end of the 4th and 20th weeks of postnatal life, the animals were sacrificed, and right optic nerves were excised and sectioned for ultrastructural and stereological analyses. We demonstrated that both DS and saline produced structural and morphometric changes in the total axon number and density of axons, but decreased the myelin sheath thickness in male optic nerves. All ultrastructural and morphometric features were well developed in 20-week-old rats. We showed that development of the optic nerve continues during the early postnatal period and that some compensation for exposure to deleterious agents in utero may occur during early postnatal life. 相似文献
46.
Network analysis of temporal functionalities of the gut induced by perturbations in new-born piglets
Nirupama Benis Dirkjan Schokker Maria Suarez-Diez Vitor AP Martins dos Santos Hauke Smidt Mari A Smits 《BMC genomics》2015,16(1)
Background
Evidence is accumulating that perturbation of early life microbial colonization of the gut induces long-lasting adverse health effects in individuals. Understanding the mechanisms behind these effects will facilitate modulation of intestinal health. The objective of this study was to identify biological processes involved in these long lasting effects and the (molecular) factors that regulate them. We used an antibiotic and the same antibiotic in combination with stress on piglets as an early life perturbation. Then we used host gene expression data from the gut (jejunum) tissue and community-scale analysis of gut microbiota from the same location of the gut, at three different time-points to gauge the reaction to the perturbation. We analysed the data by a new combination of existing tools. First, we analysed the data in two dimensions, treatment and time, with quadratic regression analysis. Then we applied network-based data integration approaches to find correlations between host gene expression and the resident microbial species.Results
The use of a new combination of data analysis tools allowed us to identify significant long-lasting differences in jejunal gene expression patterns resulting from the early life perturbations. In addition, we were able to identify potential key gene regulators (hubs) for these long-lasting effects. Furthermore, data integration also showed that there are a handful of bacterial groups that were associated with temporal changes in gene expression.Conclusion
The applied systems-biology approach allowed us to take the first steps in unravelling biological processes involved in long lasting effects in the gut due to early life perturbations. The observed data are consistent with the hypothesis that these long lasting effects are due to differences in the programming of the gut immune system as induced by the temporary early life changes in the composition and/or diversity of microbiota in the gut.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1733-8) contains supplementary material, which is available to authorized users. 相似文献47.
David Lee Tjaart AP de Beer Roman A Laskowski Janet M Thornton Christine A Orengo 《BMC structural biology》2011,11(1):2
Background
The Midwest Center for Structural Genomics (MCSG) is one of the large-scale centres of the Protein Structure Initiative (PSI). During the first two phases of the PSI the MCSG has solved over a thousand protein structures. A criticism of structural genomics is that target selection strategies mean that some structures are solved without having a known function and thus are of little biomedical significance. Structures of unknown function have stimulated the development of methods for function prediction from structure. 相似文献48.
Background
The wild rodent Calomys callosus is notably resistant to Trypanosoma cruzi infection. In order to better characterize this animal model for experimental infections, we inoculated C. callosus intraperitoneally with Paracoccidioides brasiliensis, a thermally dimorphic fungus that causes a chronic disease with severe granuloma formation in the mouse and humans. The dissemination of P. brasiliensis cells through the lungs, liver, pancreas, and spleen was assessed by histological analysis. 相似文献49.
The effect of carbon sources on the level of beta-1,3-glucanases in the culture filtrates of Trichoderma harzianum (Tc) was investigated. Enzyme activity was detected in all carbon sources, but highest levels were found when laminarin and purified cell walls were used. Three isoforms of beta-1,3-glucanase were produced during growth of the fungus on purified cell walls. Two isoforms were produced on chitin, chitosan, N-acetylglucosamine and laminarin, while only one was detected when the fungus was grown on cellulose and glucose. A 36-kDa beta-1,3-glucanase (GLU36) was secreted from T. harzianum (Tc) grown on all carbon sources tested as demonstrated by Western blot analysis. We found that a significant increase in the level of GLU36 in the culture filtrate follows glucose exhaustion, suggesting that this enzyme is controlled by carbon catabolite repression. 相似文献
50.
Protein evolution in different cellular environments: cytochrome b in sharks and mammals 总被引:4,自引:0,他引:4
DNA sequences for the mitochondrial cytochrome b gene were determined for
13 species of sharks. Rates and patterns of amino acid replacement are
compared for sharks and mammals. Absolute rates of cytochrome b evolution
are six times slower in sharks than in mammals. Bivariate plots of the
number of nonsynonymous and silent transversions are indistinguishable in
the two groups, however, suggesting that the differences in amino acid
replacement rates are due primarily to differences in DNA substitution
rates. Patterns of amino acid replacement are also similar in the two
groups. Conserved and variable regions occur in the same parts of the
cytochrome b gene, and there is little evidence that the types of amino
acid changes are significantly different between the groups. Similarity in
the relative rates and patterns of protein change between the two groups
prevails despite dramatic differences in the cellular environments of
sharks and mammals. Poor penetrance of physiological differences through to
rates of protein evolution provides support for the neutral theory and
suggests that, for cytochrome b, patterns of evolution have been relatively
constant throughout much of vertebrate history.
相似文献