Expression pattern and prognostic value of circadian clock genes in pancreatic adenocarcinoma.

Accumulating studies indicate that circadian clock genes are pivotal regulators of tumorigenesis and development of various cancers. Nevertheless, their implications in pancreatic adenocarcinoma (PAAD) remain poorly characterized. We investigated the expression pattern of circadian clock genes and evaluated their prognostic values in PAAD. Firstly, we systematically analyzed data from The Cancer Genome Atlas (TCGA) database pertaining to patient clinical information and gene expression data. We found that 19 of 20 circadian clock genes showed significantly different expression levels in comparisons between PAAD and normal tissues. In addition, 10 circadian clock genes with regression coefficients were selected to construct a new risk signature, which was then identified as an independent prognostic factor for PAAD. Mechanistically, circadian clock genes in PAAD may impact the basic state of cells and the composition of tumor-infiltrating immune cells, thus affecting disease prognosis. Finally, we construct a novel prognostic nomogram on the basis of histological nodes and risk score to precisely predict prognosis of patients with PAAD. In conclusion, our study uncovered the important role of circadian clock genes in PAAD and developed a risk signature as a promising prognostic biomarker for patients with PAAD.

[Investigation on the source of the first human of avian influenza A (H5N1) case in Beijing].

OBJECTIVE: To investigate the source of the first human case of avian influenza A (H5N1) infection in Beijing. METHODS: Interviewing the relatives of the case and other key persons, collecting and detecting samples of related biological, epidemiological and environmental data of the case were conducted. Later, the infection source was thoroughly investigated. RESULTS: The case ever contacted a slaughtered duck 5 days prior to the onset of illness, and the duck was bought from a stall of a wet market in Yanjiao area of Hebei province. Ten environmental samples were collected in this stall and the neighboring stall of the market. Another 6 samples were tested positive for H5N1 virus by PCR method, with 5 virus strains isolated. The whole-genome sequencing indicated that the amino acid homology between the H5N1 virus strains from the environment and the virus isolated from the case reached 99.8% - 100%. CONCLUSION: From both epidemiological and virological evidence, it was proved that the first human case of avian influenza A (H5N1) infection in Beijing was infected by a duck that carrying H5N1 virus the case contacted 5 days proceeding the onset of illness.