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1.
The work is dedicated to creation of the mathematical model of folate-dependent one-carbon unit metabolism (FOCM) and study of its function in human placenta under homocysteine load and the most common mutations in the genes of methylenetetrahydrofolate reductase (MTHFR) and cystathionine beta-synthase (CBS). In the model we have taken into account specific features of placental expression of genes that encode enzymes of FOCM. Using software tools Metatool and COBRAToolbox we have identified key metabolites, elementary modes and metabolic fluxes through different reactions of the system. It is shown that the most vulnerable links in the system are the folate cycle and synthesis of precursors of nucleic acids, inosine monophosphate and thymidyne monophosphates, which are changing in the broad range from significant inhibition to activation depending on the imposed conditions. The most stable links in the system are the reactions of glutathione and taurine synthesis. Simulation results coincide with the results obtained in similar experimental conditions. Under certain imposed conditions non-obvious relationships between the system links are revealed, and this becomes the basis for a purposeful test of predictions generated by the model. 相似文献
2.
Background
The statistical modeling of biomedical corpora could yield integrated, coarse-to-fine views of biological phenomena that complement discoveries made from analysis of molecular sequence and profiling data. Here, the potential of such modeling is demonstrated by examining the 5,225 free-text items in the Caenorhabditis Genetic Center (CGC) Bibliography using techniques from statistical information retrieval. Items in the CGC biomedical text corpus were modeled using the Latent Dirichlet Allocation (LDA) model. LDA is a hierarchical Bayesian model which represents a document as a random mixture over latent topics; each topic is characterized by a distribution over words. 相似文献3.
Estimating the rate of evolution of the rate of molecular evolution 总被引:35,自引:13,他引:22
A simple model for the evolution of the rate of molecular evolution is
presented. With a Bayesian approach, this model can serve as the basis for
estimating dates of important evolutionary events even in the absence of
the assumption of constant rates among evolutionary lineages. The method
can be used in conjunction with any of the widely used models for
nucleotide substitution or amino acid replacement. It is illustrated by
analyzing a data set of rbcL protein sequences.
相似文献
4.
Vipond C Mulloy B Rigsby P Burkin K Bolgiano B;the MenC IS Working Group 《Biologicals》2012,40(5):353-363
Meningococcal group C (MenC) plain polysaccharide (PS) and conjugate vaccines are primarily evaluated by physicochemical methods to ensure that batches are consistently manufactured. As different assays are employed to quantify the MenC PS content of final formulations and bulk intermediaries, there is a need for an International MenC PS Standard to calibrate internal references used in the different laboratories. Twelve laboratories from nine different countries participated in a collaborative study to determine the MenC PS content of a candidate International Standard MenC PS preparation (08/214) and to assess its suitability. On the basis of the results from this study the candidate standard 08/214 was established as an International Standard for the quantification of MenC PS content in vaccines and components. It has a content of 1.192 ± 0.192 mg MenC PS/ampoule (expanded uncertainty with coverage factor of k = 2.365 corresponding to a 95% level of confidence), as determined by the resorcinol assays carried out by eight of the participating laboratories. The standard is available from The National Institute of Biological Standards and Control who act as guardians and distributors of the material under the auspices of WHO. 相似文献
5.
Background
Ensemble attribute profile clustering is a novel, text-based strategy for analyzing a user-defined list of genes and/or proteins. The strategy exploits annotation data present in gene-centered corpora and utilizes ideas from statistical information retrieval to discover and characterize properties shared by subsets of the list. The practical utility of this method is demonstrated by employing it in a retrospective study of two non-overlapping sets of genes defined by a published investigation as markers for normal human breast luminal epithelial cells and myoepithelial cells. 相似文献6.
V. M. Drozd I. Branovan N. Shiglik M. L. Lushchyk T. Yu. Platonova V. I. Pashkevich A. V. Kudelsky I. Shimanskaya L. I. Danilova J. Biko C. Reiners 《Cytology and Genetics》2016,50(6):372-376
Nitrate content in the groundwater of Belarus has increased dramatically due to intensive use of nitrogen fertilizers in agriculture. Research performed during the post-Chernobyl period showed that the increased incidence of thyroid cancer is affected both by the level of nitrates in the groundwater and the radiation dose to which the thyroid was exposed. 相似文献
7.
V. M. Drozd M. L. Lushchyk L. I. Danilova N. M. Okulevich I. G. Shimanskaya T. A. Mitiukova N. Shiglik I. Branovan 《Cytology and Genetics》2016,50(6):361-365
The results of 30 years of regular screening and research in the radionuclide-contaminated and uncontaminated areas of Belarus are analyzed. The possible reasons for the contradictory and controversial conclusions made by different research groups that addressed the possible consequences of the Chernobyl disaster during the early postdisaster period are given. The results of the evaluation of the dynamics of the elevated incidence of thyroid cancer in children and adolescents are presented. The importance of continued screening of the population for early detection of thyroid disease is discussed. 相似文献
8.
I. Branovan M. V. Fridman M. L. Lushchyk V. M. Drozd O. V. Krasko O. V. Nedzvedz N. A. Shiglik L. I. Danilova 《Cytology and Genetics》2016,50(6):377-380
Over the recent decade, the method of radiofrequency ablation has been increasingly used for treatment of thyroid nodules. However, there is clear need for additional morphological experimental works on evaluating the effectiveness of application of different devices. This work presents results of investigation of an original device operating on the principle of bipolar radiofrequency ablation, and its high effectiveness in eliminating thyroid nodules with different consistencies and malignancy potentials has been proven, which offers broad prospects for introducing the patented radiofrequency-ablation applicator into practice, alongside other methods of minimally invasive surgery. 相似文献
9.
Alexis S. Ivanov Alexei Medvedev Pavel Ershov Andrey Molnar Yury Mezentsev Evgeny Yablokov Leonid Kaluzhsky Oksana Gnedenko Olga Buneeva Irina Haidukevich Gennadiy Sergeev Aliaksandr Lushchyk Alexey Yantsevich Marina Medvedeva Sergey Kozin Igor Popov Svetlana Novikova Victor Zgoda Andrey Gilep Sergey Usanov Andrey Lisitsa Alexander Archakov 《Proteomics》2014,14(20):2261-2274
There is increasing evidence that proteins function in the cell as integrated stable or temporally formed protein complexes, interactomes. Previously, using model systems we demonstrated applicability of direct molecular fishing on paramagnetic particles for protein interactomics (Ershov et al. Proteomics, 2012, 12, 3295). In the present study, we have used a combination of affinity‐based molecular fishing and subsequent MS for investigation of human liver proteins involved in interactions with immobilized microsomal cytochrome b5 (CYB5A), and also transthyretin and BSA as alternative affinity ligands (baits). The LC?MS/MS identification of prey proteins fished on these baits revealed three sets of proteins: 98, 120, and 220, respectively. Comparison analysis of these sets revealed only three proteins common for all the baits. In the case of paired analysis, the number of common proteins varied from 2 to 9. The binding capacity of some identified proteins has been validated by a SPR‐based biosensor. All the investigated proteins effectively interacted with the immobilized CYB5A (Kd values ranged from 0.07 to 1.1 μM). Results of this study suggest that direct molecular fishing is applicable for analysis of protein–protein interactions (PPI) under normal and pathological conditions, in which altered PPIs are especially important. 相似文献
10.
INDRIK IS KRAMS 《Ibis》2001,143(4):476-481
This paper tests the hypothesis that foraging site selection reflects a trade-off between the various needs for concealment from predators, to find food, and for the individual to maintain some view of its surroundings. After removal of Crested Tits Parus cristatus (the dominant species in mixed flocks), Willow Tits P. montanus did not decrease their foraging heights as expected but remained in the most exposed parts of young pines. In contrast, after removal of Willow Tits, Crested Tits increased their foraging height from the sheltered lower canopy to sites previously occupied by Willow Tits. When flock size was reduced, the birds maintained the same high levels of vigilance without concealing themselves in dense vegetation. I suggest that flock members may benefit from foraging in sites that afford good anti-predator vigilance. 相似文献