The purpose of this review is to provide a reference for the future prevention and control of emerging infectious diseases by summarizing the control strategies, the status of drugs and vaccines, and shortcomings during three major outbreaks of avian influenza among humans (H5N1 in 2003, H1N1 in 2009, and H7N9 in 2013). Data on and documents regarding the three influenza outbreaks have been reviewed. Results indicated that the response to pandemic influenza outbreaks has improved markedly in terms of control strategies, stockpiles of antivirals, and vaccine development. These improvements also suggest advances in disease surveillance, transparency in reporting, and regional collaboration and cooperation. These trends also foreshadow better prospects for prevention and control of emerging infectious diseases. However, there are shortcomings since strategies failed to focus on high-risk groups, quantitative and measurable results (both direct and indirect) were unclear, and quantitative assessment is still lacking.
This study is the first to isolate an Entamoeba histolytica strain from Chinese amoebic patients and to conduct a detailed examination of its virulence. A fecal sample that contains cysts of E. histolytica was obtained from Guangxi province. The sample was cultured axenically and then cloned by limiting dilution, and named as XLAC. In vitro and in vivo tests were conducted to evaluate the virulence of the Entamoeba isolate. The E. histolytica strain XLAC was successfully cloned and cultured axenically. DNA regions that contain hexokinase, glucose-6-phosphate isomerase, phosphoglucomutase, and heavy subunit of lectin genes were amplified by PCR. The PCR products were then sequenced. Virulence analysis suggested that the XLAC strain was similar to the HM1:IMSS strain at the genetic level. In vitro and in vivo tests also implicated these strains to be similar. These findings may be attributed to the low expression levels of pathogenic genes obtained through realtime PCR. The XLAC strain restored its virulence after it was injected into hamster liver. This study may be a good model for studying virulence changes in E. histolytica.
Aeroallergen avoidance has been promoted in order to prevent sensitization and the correlation between the level of allergen exposure and sensitization has been reported. The aims of this study were to monitor environmental mite infestation and to design an effective Der p 2 detection kit to estimate the number of mites in house dust samples. House dust samples were collected from 6 carpets and 2 mattresses monthly from April 2010 to March 2011. The total number of mites was counted under microscopes and Der p 2 concentrations were measured using Der p 2 ELISA kits. The detection kit was constituted using Der p 2 specific mouse monoclonal antibody as capture antibody, and rabbit polyclonal antibody as detection antibody. Both Der p crude extract and rDer p 2 were used as internal standards. The number of mites in the dust samples was significantly higher in the mattresses as compared with that in the carpets and the total number of dust mites was higher in the summer than any other seasons. The concentration of Der p 2 components in Der p crude extract was analyzed and the results showed that each gram of Der p crude extract contained 53.4 mg of Der p 2. When the number of mites and Der p 2 concentration were measured for the correlation analysis, the results showed that there was a good correlation between Der p 2 and number of mites with R2 = 0.9667. Dust mites were significantly increased in the dust samples collected from mattresses especially in the summer. The good correlation between Der p 2 concentration and mite numbers indicated that the measurement of Der p 2 can be used to replace direct mite counting. Using the Der p 2 detection method to monitor environmental mite infestation may be beneficial for allergic subjects to prevent disease activation.
The aim of this study was to investigate two mineralization-related genes TNAP and ANKH polymorphisms associated with ankylosing spondylitis (AS) in the North Chinese Han population. We carried out a case-control study in Chinese AS cohorts involving 278 AS patients and 286 unrelated healthy controls. Five TNAP SNPs (rs3200254, rs1256348, rs1472563, rs1780329, rs3767155) and four ANKH SNPs (rs25957, rs26307, rs27356, rs28006) were genotyped by the Multiplex Snapshot method. There were significant differences in genotype (permutated p = 0.00481) and allele (permutated p = 0.0126) frequencies of the rs26307 ANKH SNP between AS patients and controls. Logistic regression analysis suggested an association of AS with the polymorphism in an additive model (OR = 0.640, 95%CI = 0.480-0.853, p = 0.0023, permutation 10,000 corrected p = 0.0158) and a dominant model (OR = 0.599, 95%CI = 0.423-0.846, p = 0.0037, permutation 10,000 corrected p = 0.022). Haplotype analysis identified the ANKH haplotype rs26307(C)/rs27356 (T) as a predisposing factor for AS (OR = 1.53, 95%CI = 1.165-2.071, p = 0.0026, permutation 10,000 corrected p = 0.0103). This study provides evidence that variation in the ANKH gene influences susceptibility to AS in the Northern Han Chinese population.
The matricellular protein Follistatin-like 1 (FSTL1) has been shown to negatively regulate bone morphogenetic protein (BMP)/Smad1/5/8 signaling by functioning as an antagonist and has been implicated in physiological and pathological events including organogenesis, immunity and cardiovascular disease. It is therefore an attractive target for potential therapeutic intervention studies. In this study, we established a high-level expression system in Drosophila S2 cells which could produce about 12.5 mg of recombinant murine Follistatin-like 1 protein (rFSTL1) per liter of culture medium. The recombinant protein was then purified to greater than 95% purity using Ni-NTA agarose affinity chromatography followed by HiLoad 16/60 Superdex 200 gel filtration. The biological activity of rFSTL1 was evaluated by its ability to negatively regulate BMP/Smad1/5/8 signaling in cultured mink lung epithelial cells. Furthermore, we crystallized a truncated form of rFSTL1 containing the follistatin-like domain using the sitting drop vapor diffusion method. In conclusion, we have generated and purified biologically active recombinant FSTL1 protein, which will be important for further protein structure and drug discovery studies.
The purpose of the present study was to evaluate whether pulse pressure variation (PPV) and stroke volume variation (SVV) can predict fluid responsiveness in patients with intra-abdominal hypertension (IAH) in either a supine or Trendelenburg position. Forty mechanically ventilated patients that exhibited IAH resulting from carbon dioxide insufflation (up to 12 mmHg) underwent fluid therapy in either a supine or Trendelenburg position. Hemodynamic measurements, including PPV and SVV, were obtained before and after fluid therapy. Prediction of fluid responsiveness (> 10% increase in stroke volume) was performed by linear regression analyses. Baseline PPV and SVV values correlated closely with changes in stroke volume induced by fluid therapy, and were significantly higher in patients that subsequently responded to fluid therapy. Fluid responsiveness in patients in a supine position was predicted by a PPV threshold of > 10.5% and an SVV threshold of > 10.5%. Fluid responsiveness in patients in a Trendelenburg position was predicted by a PPV threshold of > 7.5% and an SVV threshold of > 7.0%. PPV and SVV were demonstrated to be sensitive and specific predictors of fluid responsiveness in patients with IAH in both the supine and Trendelenburg positions.
Avian influenza is one of the most dangerous contagions in poultry worldwide, and avian influenza A viruses are the major pathogens responsible. Outbreaks of H7N9, a strain of the avian influenza A virus H7 subtype, have increasingly been reported in several countries since 2007. This spring, H7N9 broke out in China and has thus far caused 24 cases of infection and 7 deaths. Recently, we treated two patients with H7N9 infection. The infection was characterized by respiratory symptoms, fever, rapid progression, and significant hypoxemia. Laboratory tests showed a low level or decrease in leukocytes, a drop in blood platelets, and an increase in myocardial enzymes and aspartate aminotransferase. Oseltamivir, anti-infective drugs, and immunoglobulin were administered. Supplemental oxygen or non-invasive mechanical ventilation helped to relieve symptoms. This report provides information on the clinical characteristics and treatment of two Chinese patients with H7N9.