Objective To develop a PCR-ELISA assay for the rapid, specific and sensitive detec-tion of human seasonal influenza virus ( H1, H3 and B) by using molecular biological and immunological methods in combination.Methods The primers were designed according to the genes encoding the matrix protein ( M) , the H1 and H3 hemagglutinin ( HA) of influenza A virus and the nonstructural proteins ( B-NS) of influenza B virus and then were labeled with biotin.The PCR products were detected by ELISA by use of an internal catching probe labeled with DIG.Results The minimum copy numbers of genes encoding the M, H1, H3 and B-NS proteins detected by the established assay were 1.43?103 , 8.67?102 , 3.86?103 and 5.45?103 copies/μl, respectively, which indicated that the PCR-ELISA assay was about 10 times more sensitive than agarose gel electrophoresis in the detection of PCR products.No cross-reactions between the different subtypes of influenza virus or different species of virus were observed.Moreover, a total of 104 clin-ical specimens of influenza virus were examined by the PCR-ELISA assay, the results of which were consist-ent with those of the virus isolation method.Conclusion The newly developed PCR-ELISA assay was a highly sensitive and specific method for the rapid detection and subtyping of influenza virus, suggesting the possibility of using it in laboratory for the surveillance and detection of influenza virus.

Shiga toxin 2 (Stx2) toxoid produced by formaldehyde treatment of purified toxin was used to immunize BALB/c mice for monoclonal antibody (MAb) production.The neutralizing activities of positive clones against Stx2 were screened by in vitro cytotoxicity assay.The isotype and specificity of resultant clone was determined,and its efficacy to neutralize the activity of purified Stx2 was evaluated by in vitro and in vivo toxicity model.Lastly,its spectrum of activity against Stx2 variants was also accessed by mouse toxicity model.It was demonstrated that one of the 12 positive MAb clones against Stx2,designating $2C4 had neutralizing activity.S2C4 belongs to the immunoglobulin G1 subclass and has a K light chain,and it reacts with the A subunit of Stx2 and does not bind to Stx2 B subunit or to Stx1.S2CA could efficiently neutralize the cytotoxicity of Stx2 to Veto cells and mice.It also protected mice against lethal doses of Stx2 variants challenge including Stx2c and Stx2vha.S2C4 is a promising candidate molecule in preventing the progression of hemolytic-uremic syndrome (HUS) mediated mainly by Stx2 in Stx-producing Escherichia coli(STEC)infection.

One influenza H3N2 virus, A/swine/Shandong/3/2005 (Sw/SD/3/2005), was isolated from pigs with respiratory disease on a farm in eastern China. Genetic analysis revealed that Sw/SD/3/2005 was a triple-reassortant virus with a PB2 gene from human-like HIN1, NS from classical swine H1NI, and the remaining genes from human-like H3N2 virus. These findings further support the concept that swine can serve as reservoir or mixing vessels of influenza virus strains and maintain genetic and antigenic stability of viruses. Furthermore, we have successfully established a reverse genetics system based on eight plasmids and rescued Sw/SD/3/2005 through cell transfection. HI tests and RT-PCR confirmed that the rescued virus maintained the biological properties of the wild type Sw/SD/3/2005. The successful establishment of the reverse genetics system of Sw/SD/3/2005 will enable us to conduct extensive studies of the molecular evolution of H3N2 influenza viruses in swine.

Objective To establish a double-antibody sandwich ELISA for the rapid detection of shiga toxin typeⅡ ( StxⅡ) in shiga toxin-producing Escherichia coli ( STEC) infection. Methods A pool of murine hybridomas was used to screen out the optimal antibody pair for the establishment of double-anti-body sandwich ELISA. The established ELISA system was used to detect StxⅡin the culture supernatants of 16 clinical strains of STEC. Specificity and sensitivity of the established ELISA system were also evaluated. Results Two antibodies, S2D8 and S2C6, were successfully screened out, based on which the double-anti-body sandwich ELISA was set up. StxⅡand its variants rather than StxⅠwas detected in the culture super-natants of STEC with a lowest detection limit of 4 ng/ml. Its performance was consistent with that of commer-cial colloidal gold test kit, indicating the characteristics of good specificity and sensitivity. Conclusion The S2D8/S2C6-based ELISA laid a foundation for researches which designates the shiga toxin as a potential can-didate on the diagnosis and therapy of STEC infection.

Objective To explore the relationship of plasma NT-proBNP level and severity of chronic congestive heart failure (CHF) and investigate the curative effect and security of meglumine adenosine cyclophosphate (MAC) combined with perindopril on patients with CHF.Methods From June 2011 to June 2013,126 inpatients with chronic congestive heart failure were randomly divided into A group (42 cases,routine therapy),B group (41 cases,routine therapy and perindopril) and C group (43 cases,routine therapy and perindopril plus MAC),all cases treated for 14 days.The left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD) by echocardiography and plasma NT-proBNP levels were evaluated before and after 14 days therapy.Results The plasma NT-proBNP levels in NYHA Ⅱ ～ Ⅳ classes were significantly difference compared each other between any two classes (P ＜0.05) and the levels was positively correlated with NYHA cardiac function class and LVEDD (r =0.617,P ＜ 0.01 ; r =0.412,P ＜ 0.01),negatively correlated with LVEF (r =-0.372,P ＜ 0.01).After 14 days therapy,compared with A group,the LVEF and LVEDD significantly improved (P ＜ 0.05) and NT-proBNP level significantly decreased (P ＜ 0.05) in B,C groups; Compared with B group,C group had lower NT-proBNP level (P ＜ 0.05) although no further improvement in cardiac function.Conclusions The plasma NT-proBNP level is correlated closely with the severity of CHF and it is a good examination of diagnose,therapy and evaluating prognosis of CHF.Perindopril may significantly decline plasma NT-proBNP level and improve cardiac function of CHF patients,combined with MAC may further decline plasma NT-proBNP level although not further improved LVEF.Giving MAC and perindopril to patients with CHF was secure and patients tolerated it well.

Objective To prepare and study the immunogenicity of hepatitis B virus surface anti-gen (HBsAg)-tetanus toxoid (TT) conjugate vaccine. Methods Tr was activated by cyangen bromide and reacted with adipic acid dihydrazide, then HBsAg-TT conjugate was prepared by carbediimide. Conjugate, HBsAg or hepatitis B vaccine was injected subcutaneously into mice. Anti-HBsAg and HBsAg-specific T cell response elicited by these immunogens were assayed. Results New HBsAg-TT conjugate elicited higher levels of anti-HBsAg and HBsAg positive conversion rates after the immunization than did HBsAg alone or hepatitis B vaccine. Conjugate induced mesdy antibodies of the IgG2a subclass, while HBsAg alone or hepa-titis B vaccine mainly elicited anti-HBsAg in the IgG1 subclass. The number of IFN-γand IL-2 secreting T cells induced by conjugate was also significantly higher than that did by HBsAg or hepatitis B vaccine. Con-clusion This study indicated new HBsAg-TT conjugate can induce both stronger humoral and TH1 type of cellular immune response.

Objective To purify Shiga toxin Ⅱ (STX Ⅱ) of enterohaemorrhagic Escherichia coli (EHEC) O157: H7 by affinity chromatography, and characterize its biological function. Methods The immno-affinity chromatography column was prepared by STX Ⅱ A subunit-specific antibody S1D8 coupling to Sepharose 4B matrix. The purity and specificity of STX Ⅱ molecule secreted by EHEC O157:H7 were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot, respectively. The purified toxin was serially diluted and the toxic activities to Vero cell line and mice were observed. The 50% cytotoxic dose (CD50) for Vero cell line and 100% lethal dose (LD100) for mice were calculated. The protection effect of anti-STX Ⅱ polysera to the mice against the purified toxin challenge was also observed. Results STX Ⅱ was successfully purified from culture supernatant of EHEC O157:H7 using affinity chromatography scheme. The relative molecular weights of STX Ⅱ A and B subunits were 32 000 and 7 500 confirmed by SDS-PAGE, respectively. The purified toxin could react with monoclonal antibodies against STX Ⅱ A and B subunits, respectively.The toxin was cytotoxic to Vero cell with CD50 of 20 ng/L and lethal to mice with LD100 of 5 ng.The toxin could be neutralized by anti-STX Ⅱ polysera in vivo. Conclusion STX Ⅱ is successfully purified and its toxic effects are confirmed in both cell line and mouse model.

Objective To investigate the renal expression changes of microRNA-215(miR-215) and its role in diabetic nephmpathy of type 2 diabetic db/db mice. Methods Fourweek-old diabetic db/db mice and norml control group non-diabetic db/m mice were selected.Real-time PCR was used to detect the relative level of miR-215 at the age of 8,12 and 16 weeks.Catenin beta interacting protein 1 (CTNNBIP1) mRNA and protein level were measured by realtime PCR,WesteRN blotting and immunohistochemisty.A lueiferase reporter assay was used to determine whether CTNNBIP1 was a direct target of miR-215. Results (1)With the growth of db/db mice,the major pathological characteristics of kidney included glomerular hypertrophy,segmental mesangial cells proliferation and mesangial matrix expansion.(2)Compared with the db/m mice,the db/db mice of 8,12 and 16 weeks showed obvious increase in body weight(BW),blood glucose (Glu) and 24 hour urinary albumin excretion (UAE) (P＜0.05,respectively).(3)Compared with the db/m mice,special miR-215 was highly expressed in the kidney of db/db mice and was up-regulated significantly according to the development of DN (P＜0.05).(4)The mRNA and protein expression of CTNNBIPl of kidney were consistently down-regulated in db/db mice than those in controls (P＜0.05,respectively). (5)By luciferase reporter,miR-215 could negatively regulate CTNNBIP1 gene by targeting its 3'-UTR sequence (P＜0.01). Conclusion High expression level of miR-215 plays a potential role in the initiation and progression of DN by down-regulating the expression of CTNNBIPl.

Phosphoinositide-3 kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway is involved in many important biological processes such as cell metabolism, growth, proliferation, and angiogenesis. And its high-level activation is closely related to the development and progression of many malignant tumors. In this paper, mTOR and PI3K/Akt/mTOR signaling pathway are introduced, and their action mechanisms in the development and progression of hepatocellular carcinoma, cholangiocellular carcinoma, cholangiocarcinoma, and gallbladder carcinoma are expounded, and then the role of mTOR inhibitors in the treatment of malignant hepatobiliary tumors is briefly described. It is thought that the PI3K/Akt/mTOR signaling pathway provides new therapeutic targets for malignant hepatobiliary tumors in advanced stage and the constant development of new mTOR inhibitors provides some new hope for the patients with malignant hepatobiliary tumors in advanced stage.

Objective: To investigate the preparation of bioactive denatured acellular dermal matrix (DADM) from burn mice riched in mice bone marrow mesenchymal stem cells. Methods: Twelve BALB/c mice were collected and 20% total body surface area scalds (hereinafter referred to as burns) with deep partial thickness were inflicted on the back skin of each mouse. After removing epidermis, the burned skin were collected and divided into Triton X-100 group and elhylene diamine tetraacetic acid (EDTA) group according to the random number table, with 15 samples in each group. Samples in Triton X-100 group and EDTA group were respectively placed in mixture of 2.5 g/L Triton X-100 and 2.5 g/L trypsin solution and mixture of 0.2 g/L EDTA and 2.5 g/L trypsin solution for sustained vibration and elution for 24 hours to make mice DADM. The general appearance of DADM was observed. The structure and arrangement of collagen fibers of DADM were observed by scanning electron microscope and tissue structure of DADM were observed by fluorescence microscope. Bone marrow mesenchymal stem cells (BMSCs) from mice were transplanted in mice DADM in the two groups with concentration of 2×105 cells per well to prepare bioactive mice DADM. After cultured for 3 days, tissue structure of bioactive mice DADM was observed by hematoxylin and eosin staining, distribution and number of BMSCs of bioactive mice DADM were observed by immunofluorescence staining. Proliferation of BMSCs of bioactive mice DADM after cultured for 2 h, 1 d, 3 d, and 5 d was detected by cell count kit-8. Data were processed with analysis of variance for repeated measurement and t test. Results: (1) Mice DADM in the two groups were white in appearance with certain tenacity and elasticity. Mice DADM in the two groups maintained good three-dimensional porous network structure. Collagen fibers of mice DADM in EDTA group were with good continuity, and collagen fibers of mice DADM in Triton X-100 group were fractured in varying degrees. Mice DADM in the two groups were decellularized completely, and the collagen fibers were loose and arranged disorderly. The continuity of tissue structure of mice DADM in EDTA group was better than that of mice DADM in Triton X-100 group. (2) After cultured for 3 days, the BMSCs in bioactive mice DADM in the two groups were evenly distributed. The number of bioactive BMSCs in mice DADM in EDTA group was 37±7, which was significantly more than that of mice DADM in Triton X-100 group (25±8, t=0.128, P<0.05). The proliferation of bioactive BMSCs in mice DADM in Triton X-100 group and EDTA group was similar at 2 hours and on day 1 after cultured (t=1.292, 0.656, P>0.05). On 3, 5 days after cultured, the proliferation of bioactive BMSCs in mice DADM in EDTA group was significantly higher than that of mice DADM in Triton X-100 group (t=2.309, 14.128, P<0.05 or P<0.01). Conclusions Mice DADM prepared by decellularization of EDTA has better three-dimensional porous network structure and good continuity of collagen fiber. The BMSCs in bioactive DADM from burn mice prepared by transplanting BMSCs are evenly distributed with large quantity and strong proliferative capacity, which has the potential to be good autologous dermal substitute.