排序方式: 共有47条查询结果,搜索用时 0 毫秒
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Herman MJ Sontrop Perry D Moerland René van den Ham Marcel JT Reinders Wim FJ Verhaegh 《BMC bioinformatics》2009,10(1):389-22
Background
Large discrepancies in signature composition and outcome concordance have been observed between different microarray breast cancer expression profiling studies. This is often ascribed to differences in array platform as well as biological variability. We conjecture that other reasons for the observed discrepancies are the measurement error associated with each feature and the choice of preprocessing method. Microarray data are known to be subject to technical variation and the confidence intervals around individual point estimates of expression levels can be wide. Furthermore, the estimated expression values also vary depending on the selected preprocessing scheme. In microarray breast cancer classification studies, however, these two forms of feature variability are almost always ignored and hence their exact role is unclear. 相似文献43.
Sequence variation among 10 alleles of the alcohol dehydrogenase (Adh) gene
of the Hawaiian drosophilid D. mimica was analyzed with reference to the
evolutionary history of the Hawaiian subgroup as well as to levels and
patterns of polymorphism of the Adh gene in continental drosophilid
species. The Adh gene of D. mimica is less polymorphic than that of other
drosophilid species, and no replacement substitutions were found.
Statistical analyses of the Adh alleles suggested the action of balancing
selection and revealed significant linkage disequilibrium among three of
the variable sites. The effective population size was estimated to be only
slightly smaller than that of continental species and, surprisingly, on the
same order of magnitude as the actual size.
相似文献
44.
Cristina Tena-Tomás Iara de Messias-Reason Le H Song Jürgen Tomiuk Peter G Kemsner Jürgen FJ Kun 《BMC genetics》2008,9(1):1-6
Background
Glutathione S-transferases (GSTs) is a genetic factor for many diseases and exhibits great diversities among various populations. We assessed association of the genotypes of Glutathione S-transferases Omega-1 (GSTO1) A140D with ethnicity in China.Results
Peripheral blood samples were obtained from 1314 individuals from 14 ethnic groups. Polymorphisms of GSTO1 A140D were measured using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Logistic regression was employed to adjustment for regional factor. The frequency of GSTO1 140A allele was 15.49% in the total 14 ethnic populations. Compared to Han ethnic group, two ethnic populations were more likely to have AA or CA genotype [odds ratio (OR): 1.77, 95% confidence interval (95% CI): 1.05–2.98 for Uygur and OR: 1.78, 95% CI: 1.18–2.69 for Hui]. However, there were no statistically significant differences across 14 ethnic groups when region factor was adjusted. In Han ethnicity, region was significantly associated with AA or CA genotype. Han individuals who resided in North-west of China were more likely to have these genotypes than those in South of China (OR: 1.63, 95% CI: 1.21–2.20).Conclusion
The prevalence of the GSTO1 140A varied significantly among different regional populations in China, which showed that geography played a more important role in the population differentiation for this allele than the ethnicity/race. 相似文献45.
Linda Spiegelberg Sigrid MA Swagemakers Wilfred FJ van IJcken Edwin Oole Eppo B Wolvius Jeroen Essers Joanna AM Braks 《Molecular medicine (Cambridge, Mass.)》2014,20(1):257-269
A side effect of radiation therapy in the head and neck region is injury to surrounding healthy tissues such as irreversible impaired function of the salivary glands. Hyperbaric oxygen therapy (HBOT) is clinically used to treat radiation-induced damage but its mechanism of action is largely unknown. In this study, we investigated the molecular pathways that are affected by HBOT in mouse salivary glands two weeks after radiation therapy by microarray analysis. Interestingly, HBOT led to significant attenuation of the radiation-induced expression of a set of genes and upstream regulators that are involved in processes such as fibrosis and tissue regeneration. Our data suggest that the TGFβ-pathway, which is involved in radiation-induced fibrosis and chronic loss of function after radiation therapy, is affected by HBOT. On the longer term, HBOT reduced the expression of the fibrosis-associated factor α-smooth muscle actin in irradiated salivary glands. This study highlights the potential of HBOT to inhibit the TGFβ-pathway in irradiated salivary glands and to restrain consequential radiation induced tissue injury. 相似文献
46.
Fernando J. Bornay-Llinares Alexandre J. da Silva Iaci N. S. Moura Przemysaw Myjak Halina Pietkiewicz Wiesawa Kruminis-ozowska Thaddeus K. Graczyk Norman J. Pieniazek 《Applied microbiology》1999,65(4):1455-1458
Apicomplexan Cryptosporidium parasites infect a wide range of vertebrate hosts. While some species are limited to a single host group, such as Cryptosporidium baileyi, which infects chickens, other species of this genus, such as C. parvum, infect a wide range of mammalian species from mice to humans. During an investigation of Cryptosporidium infection in cattle on a farm in northern Poland, we identified an infection caused by C. felis, in addition to known infections with C. muris and C. parvum. This new infection was identified based on the size of the oocysts (mean size, 4.3 ± 0.4 μm; range, 3.5 to 5.0 μm), as well as by analysis of the molecular sequence of the variable region of the small-subunit rRNA. This finding demonstrates the complex host specificity and circulation in the environment of Cryptosporidium species. 相似文献
47.
Methylmethacrylate (MMA) is the most commonly used embedding medium for sectioning undecalcified bone; however, a number of problems exist with its use in a research laboratory. MMA requires a long infiltration time and temperature control, and it reacts with many polymers. We used Kleer Set resin™ as an alternative embedding medium for sectioning undecalcified bone specimens. Fluorochrome labeled bone specimens were sectioned transversely using a ground section technique and longitudinally on a sledge macrotome. The slides were viewed using both transmitted light and epifluorescence microscopy. High quality sections were obtained using Kleer Set resin™ for both sectioning techniques. We have shown that this new embedding medium is simpler, safer, quicker to use and does not interfere with visualization of fluorochromes. 相似文献