In China, H9N2 subtype avian influenza outbreak is firstly reported in Guangdong province in 1992. Subsequently, the disease spreads into vast majority regions nationwide and has currently become endemic there. Over vicennial genetic evolution, the viral pathogenicity and transmissibility have showed an increasing trend as year goes by, posing serious threat to poultry industry. In addition, H9N2 has demonstrated significance to public health as it could not only directly infect mankind, but also donate partial or even whole cassette of internal genes to generate novel human-lethal reassortants like H5N1, H7N9, H10N8 and H5N6 viruses. In this review, we mainly focused on the epidemiological dynamics, biological characteristics, molecular phylogeny and vaccine strategy of H9N2 subtype avian influenza virus in China to present an overview of the situation of H9N2 in China.

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BackgroundTo investigate the relationship between the selective pressure and the sequence variation of the hemagglutinin-neuraminidase (HN) protein, we performed the positive selection analysis by estimating the ratio of non-synonymous to synonymous substitutions with 132 complete HN gene sequences of Newcastle disease viruses (NDVs) isolated in China.ResultsThe PAML software applying a maximum likelihood method was used for the analysis and three sites (residues 266, 347 and 540) in the HN protein were identified as being under positive selection. Codon 347 was located exactly in a recognized antigenic determinant (residues 345-353) and codon 266 in a predicted linear B-cell epitope. Substitutions at codon 540 contributed to the N-linked glycosylation potential of residue 538. To further evaluate the effect of positively selected sites on the vaccine efficacy, we constructed two recombinant fowlpox viruses rFPV-JS6HN and rFPV-LaSHN, expressing the HN proteins from a genotype VII field isolate Go/JS6/05 (with A266, K347 and A540) and vaccine strain La Sota (with V266, E347 and T540), respectively. Two groups of SPF chickens, 18 each, were vaccinated with the two recombinant fowlpox viruses and challenged by Go/JS6/05 at 3 weeks post-immunization. The results showed that rFPV-JS6HN could elicit more effective immunity against the prevalent virus infection than rFPV-LaSHN in terms of reducing virus shedding.ConclusionsThe analysis of positively selected codons and their effect on the vaccine efficacy indicated that the selective pressure on the HN protein can induce antigenic variation, and new vaccine to control the current ND epidemics should be developed.

The aim of this study is to assess the overall efficacy and safety of photoselective vaporization of the prostate (PVP) with GreenLight 120-W laser versus transurethral resection of the prostate (TURP) for treating patients of benign prostate hyperplasia (BPH) with lower urinary tract symptoms (LUTS). We performed a literature search of The Cochrane Library and the electronic databases, including Embase, Medline, and Web of Science. Manual searches were conducted of the conference proceedings, including European Association of Urology and American Urological Association (2007 to 2012). Outcomes reviewed included clinical baseline characteristics, perioperative data, complications, and postoperative functional results, such as postvoid residual (PVR), international prostate symptom score (IPSS), quality of life (QoL), and maximum flow rate (Qmax). Six randomized controlled trials (RCTs) were enrolled. Three hundred and forty-seven patients undergone 120-W PVP, and 350 patients were treated with TURP in the RCTs. There were no significant differences for clinical characteristics in these trials. In perioperative data, catheterization time and length of hospital stay were shorter in the PVP group. However, the operation time was shorter in the TURP group. Capsular perforation, blood transfusion, clot retention, and macroscopic hematuria were markedly less likely in PVP-treated subjects. The other complications between PVP and TURP did not demonstrate a statistic difference. There were no significant differences in QoL, PVR, IPSS, and Qmax in the 1, 3, 6, 12, and 24 months of postoperative follow-up. There was no significant difference at postoperation follow-up of functional outcomes including IPSS, PVR, Qmax, and QoL between the TURP-treated subjects and PVP-treated subjects. Owing to a shorter catheterization time, reduced hospital duration and less complication, PVP could be used as an alternative and a promising minimal invasive surgical procedure for the treatment of BPH.