Last data update: Jun 03, 2024. (Total: 46935 publications since 2009)
Records 1-4 (of 4 Records) |
Query Trace: Murray JR [original query] |
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Identification of Phosphoglycerate Kinase 1 (PGK1) as a reference gene for quantitative gene expression measurements in human blood RNA.
Falkenberg VR , Whistler T , Murray JR , Unger ER , Rajeevan MS . BMC Res Notes 2011 4 324 BACKGROUND: Blood is a convenient sample and increasingly used for quantitative gene expression measurements with a variety of diseases including chronic fatigue syndrome (CFS). Quantitative gene expression measurements require normalization of target genes to reference genes that are stable and independent from variables being tested in the experiment. Because there are no genes that are useful for all situations, reference gene selection is an essential step to any quantitative reverse transcription-PCR protocol. Many publications have described appropriate genes for a wide variety of tissues and experimental conditions, however, reference genes that may be suitable for the analysis of CFS, or human blood RNA derived from whole blood as well as isolated peripheral blood mononuclear cells (PBMCs), have not been described. FINDINGS: Literature review and analyses of our unpublished microarray data were used to narrow down the pool of candidate reference genes to six. We assayed whole blood RNA from Tempus tubes and cell preparation tube (CPT)-collected PBMC RNA from 46 subjects, and used the geNorm and NormFinder algorithms to select the most stable reference genes. Phosphoglycerate kinase 1 (PGK1) was one of the optimal normalization genes for both whole blood and PBMC RNA, however, additional genes differed for the two sample types; Ribosomal protein large, P0 (RPLP0) for PBMC RNA and Peptidylprolyl isomerase B (PPIB) for whole blood RNA. We also show that the use of a single reference gene is sufficient for normalization when the most stable candidates are used. CONCLUSIONS: We have identified PGK1 as a stable reference gene for use with whole blood RNA and RNA derived from PBMC. When stable genes are selected it is possible to use a single gene for normalization rather than two or three. Optimal normalization will improve the ability of results from PBMC RNA to be compared with those from whole blood RNA and potentially allows comparison of gene expression results from blood RNA collected and processed by different methods with the intention of biomarker discovery. Results of this study should facilitate large-scale molecular epidemiologic studies using blood RNA as the target of quantitative gene expression measurements. |
Evaluation of DNA extraction from granulocytes discarded in the separation medium after isolation of peripheral blood mononuclear cells and plasma from whole blood.
Murray JR , Rajeevan MS . BMC Res Notes 2013 6 440 BACKGROUND: Whole blood is generally processed for plasma and peripheral blood mononuclear cells (PBMCs) from granulocytes/erythrocytes using gradient centrifugation of blood with Histopaue-Ficoll. After separation of plasma and PBMCs, the residual erythrocytes/granulocytes, a rich source of DNA, is often discarded along with the separation medium. In order to isolate DNA from the granulocytes, current methods require the removal of the separation medium and subsequent purification of granulocytes. This report provides a method for extracting DNA using the PAXgene Blood DNA kit from granulocytes without purifying them from the separation medium. FINDINGS: Based on 719 erythrocyte/granulocyte samples stored frozen for approximately 10 years in Ficoll-Hypaque separation medium, the mean yield of DNA was 395 μg (median = 281 μg; range = 1.36 to 2077.2 μg), with mean A260/A280 ratio of 1.84 (median = 1.84; range = 1.17 to 2.23). The quality of isolated DNA was sufficient for use as a template for restriction enzyme digestion, real-time PCR, pyrosequencing, and gel based variable number tandem repeats (VNTR) genotyping. CONCLUSIONS: By demonstrating the extraction of substantial amounts of high quality granulocytes DNA without purifying them from the separation medium, this method offers laboratories and biobanks a flexible and cost-effective approach to obtain plasma, PBMCs, and large amounts of DNA from a single blood collection for a variety of molecular genetics/epidemiologic studies. |
Severe Acute Respiratory Syndrome Coronavirus 2 Prevalence, Seroprevalence, and Exposure among Evacuees from Wuhan, China, 2020.
Hallowell BD , Carlson CM , Jacobs JR , Pomeroy M , Steinberg J , Tenforde MW , McDonald E , Foster L , Feldstein LR , Rolfes MA , Haynes A , Abedi GR , Odongo GS , Saruwatari K , Rider EC , Douville G , Bhakta N , Maniatis P , Lindstrom S , Thornburg NJ , Lu X , Whitaker BL , Kamili S , Sakthivel SK , Wang L , Malapati L , Murray JR , Lynch B , Cetron M , Brown C , Roohi S , Rotz L , Borntrager D , Ishii K , Moser K , Rasheed M , Freeman B , Lester S , Corbett KS , Abiona OM , Hutchinson GB , Graham BS , Pesik N , Mahon B , Braden C , Behravesh CB , Stewart R , Knight N , Hall AJ , Killerby ME . Emerg Infect Dis 2020 26 (9) 1998-2004 To determine prevalence of, seroprevalence of, and potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among a cohort of evacuees returning to the United States from Wuhan, China, in January 2020, we conducted a cross-sectional study of quarantined evacuees from 1 repatriation flight. Overall, 193 of 195 evacuees completed exposure surveys and submitted upper respiratory or serum specimens or both at arrival in the United States. Nearly all evacuees had taken preventive measures to limit potential exposure while in Wuhan, and none had detectable SARS-CoV-2 in upper respiratory tract specimens, suggesting the absence of asymptomatic respiratory shedding among this group at the time of testing. Evidence of antibodies to SARS-CoV-2 was detected in 1 evacuee, who reported experiencing no symptoms or high-risk exposures in the previous 2 months. These findings demonstrated that this group of evacuees posed a low risk of introducing SARS-CoV-2 to the United States. |
Development of an RNA strand-specific hybridization assay to differentiate replicating versus non-replicating influenza A virus.
Yang G , Hodges EN , Winter J , Zanders N , Shcherbik S , Bousse T , Murray JR , Muraduzzaman AKM , Rahman M , Alamgir ASM , Sabrina Flora M , Blanton L , Barnes JR , Wentworth DE , Davis CT . J Clin Microbiol 2020 58 (6) Replication of influenza A virus (IAV) from negative-sense viral RNA (vRNA) requires the generation of positive-sense RNA (+RNA). Most molecular assays, such as conventional real-time RT-PCR (rRT-PCR), detect total RNA in a sample without differentiating vRNA from +RNA. These assays are not designed to distinguish IAV infection versus exposure of an individual to an environment enriched with IAVs, but wherein no viral replication occurs. We, therefore, developed a strand-specific hybridization (SSH) assay that differentiates between vRNA and +RNA and quantifies relative levels of each RNA species. The SSH assay exhibited a linearity of 7 logs with a lower limit of detection of 6.0x10(2) copies of molecules per reaction. No signal was detected in samples with a high load of non-target template or influenza B virus, demonstrating assay specificity. IAV +RNA was detected at 2-4 hours post-inoculation of MDCK cells, whereas synthesis of cold-adapted IAV +RNA was significantly impaired at 37 degrees C. The SSH assay was then used to test IAV rRT-PCR positive nasopharyngeal specimens collected from individuals exposed to IAV at swine exhibitions (n=7) or while working at live bird markets (n=2). The SSH assay was able to differentiate vRNA and +RNA in samples collected from infected, symptomatic individuals versus individuals who were exposed to IAV in the environment, but had no active viral replication. Data generated with this technique, especially when coupled with clinical data and assessment of seroconversion, will facilitate differentiation of actual IAV infection with replicating virus versus individuals exposed to high levels of environmental contamination, but without virus infection. |
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