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排序方式: 共有103条查询结果,搜索用时 15 毫秒
61.
Kristina A Tendl Stefan MF Schulz Thomas P Mechtler Adele Bohn Thomas Metz Susanne Greber-Platzer David C Kasper Kurt R Herkner Chike B Item 《Epigenetics》2013,8(12):1261-1267
Diagnosis of bacterial sepsis in preterm neonates can be difficult when using serum markers that rely on physiological changes because these changes may not necessarily be the result of bacterial infections alone. This retrospective investigation explores the potential use of the DNA methylation pattern of CpG sites in the promoter region of the calcitonin-related polypeptide α (CALCA) gene as an epigenetic biomarker for bacterial sepsis in preterm newborns. Four novel changes in the DNA methylation of eight CpG sites were detected in this gene and are present only in neonates with bacterial sepsis: (1) partial methylation at -769 CpG in gram-negative or gram-positive early onset sepsis (EOS) and late onset sepsis (LOS) episodes; (2) demethylation of 8 CpGs in gram-negative EOS followed by LOS (ELS) and in gram-negative EOS; (3) demethylation of 7 CpGs in gram-positive ELS and gram-positive EOS; (4) -771 C:G > T:A; 5′ de novo -778 CpG mutation on both alleles in EOS. These changes were not detected in birth weight and gestational age matched controls or in newborns with isolated infections. Our results indicate that the DNA methylation pattern of the promoter region of the CALCA gene varies in different types of bacterial preterm sepsis, thus suggesting a potential use as an epigenetic biomarker. A prospective confirmation of these results is essential. 相似文献
62.
Juliana R Martins Francis MF Nunes Alexandre S Cristino Zilá LP Simões Márcia MG Bitondi 《BMC molecular biology》2010,11(1):23
Background
Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens. 相似文献63.
Status of complete proteome analysis by mass spectrometry: SILAC labeled yeast as a model system 总被引:5,自引:1,他引:4
Background
Mass spectrometry has become a powerful tool for the analysis of large numbers of proteins in complex samples, enabling much of proteomics. Due to various analytical challenges, so far no proteome has been sequenced completely. O'Shea, Weissman and co-workers have recently determined the copy number of yeast proteins, making this proteome an excellent model system to study factors affecting coverage. 相似文献64.
Background
Optical imaging is an attractive non-invasive way to evaluate the expression of a transferred DNA, mainly thanks to its lower cost and ease of realization. In this study optical imaging was evaluated for monitoring and quantification of the mouse knee joint and tibial cranial muscle electrotransfer of a luciferase encoding plasmid. Optical imaging was applied to study the kinetics of luciferase expression in both tissues. 相似文献65.
Sirantha Perera Yun‐Cheol Na Thomas Doundoulakis Victor J. Ngo Qing Feng Zachary S. Breitbach Carl J. Lovely Daniel W. Armstrong 《Chirality》2013,25(2):133-140
High performance liquid chromatography (HPLC) and capillary electrophoresis (CE) were used to examine the enantiomeric separation of a series of 17 racemic tetrahydrobenzimidazole analytes. These compounds were prepared as part of a synthetic program directed towards a select group of pyrrole‐imidazole alkaloids. This group of natural products has a unique framework of pyrrole‐ and guanidine‐containing fused rings which can be constructed through the intermediacy of a tetrahydrobenzimidazole scaffold. Several bonded cyclodextrin‐ (both native and derivatized) and derivatized cyclofructan‐based chiral stationary phases were evaluated for their ability to separate these racemates via HPLC. Similarly, several cyclodextrin derivatives and derivatized cyclofructan were evaluated for their ability to separate this set of chiral compounds via CE. Enantiomeric selectivity was observed for the entire set of racemic compounds using HPLC with resolution values up to 3.0. Among the 12 different CSPs, enantiomeric recognition was most frequently observed with the Cyclobond RN and LARIHC CF6‐P, while the Cyclobond DMP yielded the greatest number of baseline separations. Fifteen of the analytes showed enantiomeric recognition in CE with resolution values as high as 5.0 and hydroxypropyl‐γ‐cyclodextrin was the most effective chiral additive. Chirality 25:133–140, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
66.
67.
Polina D. Freitas Alexander M. Lovely James R. Monaghan 《Developmental neurobiology》2019,79(5):453-467
Amputation of a salamander tail leads to functional spinal cord regeneration through activation of endogenous stem cells. Identifying the signaling pathways that control cell proliferation in these neural stem cells will help elucidate the mechanisms underlying the salamander’s regenerative ability. Here, we show that neuregulin 1 (Nrg1)/ErbB2 signaling is an important pathway in the regulation of neural stem cell proliferation in the spinal cord of the axolotl salamander (Ambystoma mexicanum). Simultaneous localization of nrg1 mRNA and Nrg1 protein was performed by utilizing a hybridization chain reaction fluorescence in situ hybridization (FISH) methodology in tissue sections. Multiplexed FISH also permitted the phenotyping of multiple cell types on a single fixed section allowing the characterization of mRNA expression, protein expression, and tissue architecture. Pharmacological inhibition of ErbB2 showed that intact Nrg1/ErbB2 signaling is critical for adult homeostatic regeneration as well as for injury‐induced spinal cord regeneration. Overall, our results highlight the importance of the NRG1/ErbB2 signaling pathway in neural stem cell proliferation in the axolotl. 相似文献
68.
Raphael B. Costa Gregório MF Camargo Iara DPS Diaz Natalia Irano Marina M. Dias Roberto Carvalheiro Arione A. Boligon Fernando Baldi Henrique N. Oliveira Humberto Tonhati Lucia G. Albuquerque 《遗传、选种与进化》2015,47(1)
Background
An important goal of Zebu breeding programs is to improve reproductive performance. A major problem faced with the genetic improvement of reproductive traits is that recording the time for an animal to reach sexual maturity is costly. Another issue is that accurate estimates of breeding values are obtained only a long time after the young bulls have gone through selection. An alternative to overcome these problems is to use traits that are indicators of the reproductive efficiency of the herd and are easier to measure, such as age at first calving. Another problem is that heifers that have conceived once may fail to conceive in the next breeding season, which increases production costs. Thus, increasing heifer’s rebreeding rates should improve the economic efficiency of the herd. Response to selection for these traits tends to be slow, since they have a low heritability and phenotypic information is provided only later in the life of the animal. Genome-wide association studies (GWAS) are useful to investigate the genetic mechanisms that underlie these traits by identifying the genes and metabolic pathways involved.Results
Data from 1853 females belonging to the Agricultural Jacarezinho LTDA were used. Genotyping was performed using the BovineHD BeadChip (777 962 single nucleotide polymorphisms (SNPs)) according to the protocol of Illumina - Infinium Assay II ® Multi-Sample HiScan with the unit SQ ™ System. After quality control, 305 348 SNPs were used for GWAS. Forty-two and 19 SNPs had a Bayes factor greater than 150 for heifer rebreeding and age at first calving, respectively. All significant SNPs for age at first calving were significant for heifer rebreeding. These 42 SNPs were next or within 35 genes that were distributed over 18 chromosomes and comprised 27 protein-encoding genes, six pseudogenes and two miscellaneous noncoding RNAs.Conclusions
The use of Bayes factor to determine the significance of SNPs allowed us to identify two sets of 42 and 19 significant SNPs for heifer rebreeding and age at first calving, respectively, which explain 11.35 % and 6.42 % of their phenotypic variance, respectively. These SNPs provide relevant information to help elucidate which genes affect these traits. 相似文献69.
Eduardo?M?Del Aguila Marcio?B?Dutra Joab?T?Silva Vania?MF?PaschoalinEmail author 《BMC molecular biology》2005,6(1):9
Background
Preparation of RNA free from DNA is a critical step before performing RT-PCR assay. Total RNA isolated from several sources, including those obtained from Saccharomyces cerevisiae, using routine methodologies are frequently contaminated with DNA, which can give rise to amplification products that mimic the amplicons expected from the RNA target. 相似文献70.
Eduardo?S?SilvaEmail author Gerard?J?Schoone Celia?MF?Gontijo Reginaldo?P?Brazil Raquel?S?Pacheco Henk?DFH?Schallig 《Kinetoplastid biology and disease》2005,4(1):4