Search

On December 31, 2019, a cluster of severe pneumonia cases in Wuhan, Hubei Province, China, was reported (1). On January 7, 2020, a novel coronavirus, severe acute respiratory syndrome coronavirus [...]

On December 31, 2019, an outbreak of an unexplained acute respiratory disease, later designated coronavirus disease (COVID-19), was reported in Wuhan, China (1). On January 7, 2020, a novel coronavirus, [...]

A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been identified as the source of a pneumonia outbreak in Wuhan, China, in late 2019 (2,2). The virus was [...]

Abstract 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 Findings Literature review and analyses of our unpublished microarray data were used to narrow down the pool of candidate reference genes to six.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.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified as the etiologic agent associated with coronavirus disease, which emerged in late 2019. In response, we developed a diagnostic panel consisting of 3 real-time reverse transcription PCR assays targeting the nucleocapsid gene and evaluated use of these assays for detecting SARS-CoV-2 infection. All assays demonstrated a linear dynamic range of 8 orders of magnitude and an analytical limit of detection of 5 copies/reaction of quantified RNA transcripts and 1 x 10-1.5 50% tissue culture infectious dose/mL of cell-cultured SARS-CoV-2. All assays performed comparably with nasopharyngeal and oropharyngeal secretions, serum, and fecal specimens spiked with cultured virus. We obtained no false-positive amplifications with other human coronaviruses or common respiratory pathogens. Results from all 3 assays were highly correlated during clinical specimen testing. On February 4, 2020, the Food and Drug Administration issued an Emergency Use Authorization to enable emergency use of this panel. [ABSTRACT FROM AUTHOR]

Background: Few studies have examined the long-term, cross-national, and population-level impacts of exclusive breastfeeding on major global child health indicators. We investigated the overall and independent associations between exclusive breastfeeding and under-five mortality in 57 low- and-middle-income countries., Methods: Data were obtained from the latest World Health Organization, United Nations, and United Nations Children's Fund databases for 57 low- and middle-income countries covering the periods 2006-2014. Multivariate linear regression was used to estimate the effects of exclusive breastfeeding on under-five mortality after adjusting for differences in socioeconomic, demographic, and health-related factors., Results: In multivariate models, exclusive breastfeeding was independently associated with under-five mortality after adjusting for sociodemographic and health systems-related factors. A 10 percentage-points increase in exclusive breastfeeding was associated with a reduction of 5 child deaths per 1,000 live births. A one-unit increase in Human Development Index was associated with a decrease of 231 under-five child deaths per 1,000 live births. A $100 increase in per capita health care expenditure was associated with a decrease of 2 child deaths per 1,000 live births. One unit increase in physician density was associated with 2.8 units decrease in the under-five mortality rate., Conclusions and Global Health Implications: Population-level health system and socioeconomic factors exert considerable effect on the association between exclusive breastfeeding and under-five mortality. Given that the health policy and socioeconomic indicators shown to influence exclusive breastfeeding and under-five mortality are modifiable, policy makers could potentially target specific policies and programs to address national-level deficiencies in these sectors to reduce under-five mortality in their countries.