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The MicroArray Quality Control (MAQC) project shows inter- and intraplatform reproducibility of gene expression measurements 总被引:2,自引:0,他引:2
MAQC Consortium Shi L Reid LH Jones WD Shippy R Warrington JA Baker SC Collins PJ de Longueville F Kawasaki ES Lee KY Luo Y Sun YA Willey JC Setterquist RA Fischer GM Tong W Dragan YP Dix DJ Frueh FW Goodsaid FM Herman D Jensen RV Johnson CD Lobenhofer EK Puri RK Schrf U Thierry-Mieg J Wang C Wilson M Wolber PK Zhang L Amur S Bao W Barbacioru CC Lucas AB Bertholet V Boysen C Bromley B Brown D Brunner A Canales R Cao XM Cebula TA Chen JJ Cheng J Chu TM Chudin E Corson J Corton JC Croner LJ 《Nature biotechnology》2006,24(9):1151-1161
Over the last decade, the introduction of microarray technology has had a profound impact on gene expression research. The publication of studies with dissimilar or altogether contradictory results, obtained using different microarray platforms to analyze identical RNA samples, has raised concerns about the reliability of this technology. The MicroArray Quality Control (MAQC) project was initiated to address these concerns, as well as other performance and data analysis issues. Expression data on four titration pools from two distinct reference RNA samples were generated at multiple test sites using a variety of microarray-based and alternative technology platforms. Here we describe the experimental design and probe mapping efforts behind the MAQC project. We show intraplatform consistency across test sites as well as a high level of interplatform concordance in terms of genes identified as differentially expressed. This study provides a resource that represents an important first step toward establishing a framework for the use of microarrays in clinical and regulatory settings. 相似文献
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Abstract: The ontogenetic expression of myelin basic protein (arginine) methyltransferase in myelinogenic cultures of cells dissociated from embryonic mouse brain is highly dependent on the presence of thyroid hormone. Restoration of myelin basic protein methyltransferase to normal activities occurred 16 h after the addition of 100 n M l -3,5,3'-triiodothyronine to hypothyroid medium. These data demonstrate that thyroid hormone can regulate a posttranslational event. On the other hand, histone (arginine) methyltransferase has a different temporal activity pattern, which is not coordinated with myelination, and is not influenced by the lack of thyroid hormone. These data, which suggest the existence of two methyltransferases, were substantiated by demonstrating that the total amount of methylation of added myelin basic protein and histone is the same whether they are incubated together or separately. The requirement of thyroid hormone for the expression of the myelin basic protein methyltransferase and not for histone methyltransferase suggests that thyroid hormone preferentially regulates myelin-associated events in these cultures. 相似文献
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Cultures of cells dissociated from embryonic mouse brain were used to assess the period in which thyroid hormone exerts its maximum influence on the regulation of the expression of two myelin associated metabolites, sulfolipids and 23-cyclic nucleotide 3-phosphohydrolase (CNP-ase). Cultures were grown for a specified number of days on a medium containing normal calf serum and then a portion were switched to a medium containing hypothyroid calf serum for 2 days. One half of these cultures were then supplemented with 50 nM triiodothyronine and growth was continued in all cultures for 3 more days. The cells were then assayed for CNP-ase activity and for their ability to incorporate35SO4 into sulfolipids. Studies with both myelin markers showed that in the earlier culture ages of 5, 8, and 11 days, thyroid hormone was able to fully restore the activities when abbed to cultures grown on hypothyroid calf-serum. In contrast, in the intermediate age range (15, 19, and 22 days) the restoration was partial, while in the higher ages, there was practically negligible restoration with T3. Since the culture system eliminates the possibility of a blood brain barrier and drastically decreases the complicity of other hormones, the lack of a myelinogeni response to thyroid hormone after a certain age must be attributed to the loss of sensitivity of the oligodendroglia to T3 possibly through genetic programming. 相似文献
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Ingrid Parmentier Ryan J. Harrigan Wolfgang Buermann Edward T. A. Mitchard Sassan Saatchi Yadvinder Malhi Frans Bongers William D. Hawthorne Miguel E. Leal Simon L. Lewis Louis Nusbaumer Douglas Sheil Marc S. M. Sosef Kofi Affum‐Baffoe Adama Bakayoko George B. Chuyong Cyrille Chatelain James A. Comiskey Gilles Dauby Jean‐Louis Doucet Sophie Fauset Laurent Gautier Jean‐François Gillet David Kenfack François N. Kouamé Edouard K. Kouassi Lazare A. Kouka Marc P. E. Parren Kelvin S.‐H. Peh Jan M. Reitsma Bruno Senterre Bonaventure Sonké Terry C. H. Sunderland Mike D. Swaine Mbatchou G. P. Tchouto Duncan Thomas Johan L. C. H. Van Valkenburg Olivier J. Hardy 《Journal of Biogeography》2011,38(6):1164-1176
Aim Our aim was to evaluate the extent to which we can predict and map tree alpha diversity across broad spatial scales either by using climate and remote sensing data or by exploiting spatial autocorrelation patterns. Location Tropical rain forest, West Africa and Atlantic Central Africa. Methods Alpha diversity estimates were compiled for trees with diameter at breast height ≥ 10 cm in 573 inventory plots. Linear regression (ordinary least squares, OLS) and random forest (RF) statistical techniques were used to project alpha diversity estimates at unsampled locations using climate data and remote sensing data [Moderate Resolution Imaging Spectroradiometer (MODIS), normalized difference vegetation index (NDVI), Quick Scatterometer (QSCAT), tree cover, elevation]. The prediction reliabilities of OLS and RF models were evaluated using a novel approach and compared to that of a kriging model based on geographic location alone. Results The predictive power of the kriging model was comparable to that of OLS and RF models based on climatic and remote sensing data. The three models provided congruent predictions of alpha diversity in well‐sampled areas but not in poorly inventoried locations. The reliability of the predictions of all three models declined markedly with distance from points with inventory data, becoming very low at distances > 50 km. According to inventory data, Atlantic Central African forests display a higher mean alpha diversity than do West African forests. Main conclusions The lower tree alpha diversity in West Africa than in Atlantic Central Africa may reflect a richer regional species pool in the latter. Our results emphasize and illustrate the need to test model predictions in a spatially explicit manner. Good OLS or RF model predictions from inventory data at short distance largely result from the strong spatial autocorrelation displayed by both the alpha diversity and the predictive variables rather than necessarily from causal relationships. Our results suggest that alpha diversity is driven by history rather than by the contemporary environment. Given the low predictive power of models, we call for a major effort to broaden the geographical extent and intensity of forest assessments to expand our knowledge of African rain forest diversity. 相似文献
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Penile amputation due to circumcision is a tragic complication in which the operator is responsible. The current treatment is based on microsurgical replantation methods by anastomosing penile dorsal vessels and nerves. We report a new case of penile glans amputation due to circumcision in a 6-year-old boy. Replantation was done without microvascular and nerves anastomosis. After 7 months of treatment, the final result was found to be good in terms of the urinary stream, erectile function, sensitivity and morphological aspect of the glans. 相似文献
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Raksha Raghunathan Chih‐Hao Liu Amur Kouka Manmohan Singh Rajesh C. Miranda Kirill V. Larin 《Journal of biophotonics》2019,12(8)
Marijuana is one of the most commonly abused substances during pregnancy. Synthetic cannabinoids (SCBs) are a group of heterogeneous compounds that are 40‐ to 600‐fold more potent than Δ9‐tetrahydrocannabinol, the major psychoactive component of marijuana. With SCBs being legally available for purchase and the prevalence of unplanned pregnancies, the possibility of prenatal exposure to SCBs is high. However, the effects of prenatal SCB exposure on embryonic brain development are not well understood. In this study, we use complex correlation mapping optical coherence angiography to evaluate changes in murine fetal brain vasculature in utero, minutes after maternal exposure to an SCB, CP‐55940. Results showed a significant decrease (P < 0.05) in fetal brain vessel diameter, length fraction and area density when compared to the sham group. This preliminary study shows that acute prenatal exposure to an SCB resulted in significant fetal brain vasoconstriction during the peak period for brain development. 相似文献
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