Comparing the multiplex RT-PCR method and liquichip technology in the detection of diarrhea-related virus / 中华检验医学杂志

Objective To compare the detection efficiency between multiplex RT-PCR method and liquichip technology for screening the viral etiological agents of diarrhea.Methods The development of the multiplex RT-PCR method.A total of 107 feces samples from patients who suffered from diarrhea and attended to Zhujiang Hospital of Southern University from September 2013 to February 2014 were collected and tested in parallel by both multiplex RT-PCR and xTAG Gastrointestinal Pathogen Panel ( xTAG GPP) for Adenovirus, Norovirus genogroupⅠandⅡ, as well as by both multiplex RT-PCR and monoplex RT-PCR for Astrovirus and Sapovirus.To evaluate the sensitivity and specificity of multiplex RT-PCR, xTAG GPP and monoplex RT-PCR were used as reference.Kappa coefficient test was used to evaluate the consistency among the methods.The detection limit and accuracy of multiplex RT-PCR were evaluated by detection of serial dilution of positive plasmids and products sequencing for the five viral agents.Results The multiplex RT-PCR showed high consistency with xTAG GPP and monoplex RT-PCR, in which Kappa value was 0.885 and 1.000 respectively( P=0.000 ).Compared to xTAG GPP, the sensitivity and specificity of the multiplex RT-PCR were at average of 80.8%( 21/26 ) and 100%( 295/295 ) respectively.The detection limit and accuracy of multiplex RT-PCR were 104 copies /μl-106 copies/μl.Conclusion The high consistency indicated that both the multiplex RT-PCR and xTAG GPP are useful as a special,sensitive, high throughput and rapid diagnostic tools for the detection of the major viral pathogens related to diarrhea in clinical laboratory.

Expression and identification of the functional domains of dengue virus type 1 envelope protein in 293T cells / 中华微生物学和免疫学杂志

Objective To construct a recombinant expression vector for expression of the function-al domains of dengue virus serotype 1 ( DENV1 ) envelope ( E ) protein in native soluble form. Methods The genes encoding the functional domains of DENV1-E protein (1-394 aa) were amplified with PCR and then cloned into the Psectag2B-Fc eukaryotic expression vector.The 293T cells were transfected with the recombinant vector by cationic lipid-based delivery.The cell clones expressing the fusion DENV1-E-Fc protein were screened out with 2 mg/ml of Zeocin.Immunofluorescence assay ( IFA) was performed to analyze the antigenicity and integrity of the fusion protein.The fusion proteins were purified from cell lysate with Protein-G and further identified by Western blot assay.Results The soluble form of fusion protein with a molecular weight of about 90×103 was obtained at a yield of about 25 μg per 1×107 cells.The results of IFA indicated that the fusion protein kept its integrity with right conformational epitopes.The fusion protein was successfully expressed with the advantage of good specificity as indicated by IFA and Western blot assay. Conclusion The recombinant fusion protein in soluble form was successfully expressed in eukaryotic ex-pression system, which paved the way for further investigation on the function of DENV1 E protein and its protective epitopes.

Double-antigen sandwich ELISA for detecting Aspergillus fumigatus anti-Afmp1cr and Afmp2cr antibodies / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish two double-antigen sandwich ELISA systems to detect anti-Afmp1cr and Afmp2cr antibodies of Aspergillus fumigatus.</p><p><b>METHODS</b>Recombinant Afmp1cr and Afmp2cr proteins of A.fumigatus expressed in Pichia pastoris were obtained. Double-antigen sandwich ELISA systems for detecting specific anti-Afmp1cr and anti-Afmp2cr antibodies were developed after chessboard titrating to determine the appropriate concentrations of the recombinant proteins and HRP-labeled proteins. The sensitivity of the assay was evaluated using serum samples of rabbits immunized with Afmp1cr and Afmp2cr. The specificity of the assay was evaluated by detecting serum samples from healthy donors and patients with other pathogenic fungal and baterial infections. The performance of the two ELISA kits was furthered evaluated using serum samples from patients with suspected Aspergillus infection.</p><p><b>RESULTS</b>The established ELISA kits were capable of detecting anti-Afmp1cr and anti-Afmp2cr antibodies in immunized rabbit serum at the maximum dilutions of 800 and 3200, respectively. No cross-reactivity was observed in detecting serum from patients with other pathogenic fungal or bactetial infections. Both of the two kits yielded positive results in sera from two established Aspergillus-infected cases and a suspected case.</p><p><b>CONCLUSIONS</b>Two antibody-capture ELISA kits were developed for the laboratory diagnosis of A.fumigatus infection and can be potentially useful in the clinical diagnosis of Aspergillosis infections.</p>

A double-antigen sandwich ELISA for detecting Penicillium marneffei Mp1p-specific antibody / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an immunological method for detecting antibodies of Penicillium marneffei.</p><p><b>METHODS</b>The recombinant Mp1p protein of Penicillium marneffei was expressed in Pichia pastoris and labeled with HRP (Mp1p-HRP) with a modified sodium periodate method. A double-antigen sandwich enzyme-linked immunosorbant assay (ELISA) was established by determining the optimal coating concentration of Mp1p protein and the concentration of the detecting protein Mp1p-HRP. The sensitivity and specificity of the assay was evaluated by detecting Mp1p antibodies in 100 serum samples from healthy donors, 15 samples from culture-confirmed penicilliosis patients, and 21 samples from patients with culture-confirmed other fungal infections.</p><p><b>RESULTS</b>A double-antigen sandwich ELISA was successfully established for detecting Mp1p-specific antibody. The specificity of the assay was 100% (121/121) for detecting Mp1p-specific antibody in the sera from healthy donors and patients with other fungal infection. The detection results of the 15 serum samples from patients with culture-confirmed penicilliosis showed positivity for Mp1p antibody in 2 samples and Mp1p antigen positivity in 12 samples; combining the detection results of Mp1p antigen and antibody obviously increased the diagnostic sensitivity to 93.3% (14/15).</p><p><b>CONCLUSION</b>The double-antigen sandwich ELISA shows a high specificity in detecting Mp1p-specific antibody, and simultaneous detection of Mp1p antigen and antibody can increase the diagnostic sensitivity for penicilliosis.</p>

Prevalence of chromosome 9 abnormalities among pediatric specimens / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform cytogenetic analysis for children, especially newborns suspected for chromosome abnormalities.</p><p><b>METHODS</b>Peripheral blood or born marrow specimens were respectively cultured in proper media. Karyograms were analyzed following G-banding.</p><p><b>RESULTS</b>Of 154 blood specimens, numerical chromosomal abnormalities were identified in 20 patients, which included 19 with trisomy 21. Structural aberrations were identified in 13 patients, among which chromosome 9 aberrations were seen in 6 cases. These included 3 inversions, 1 deletion, 1 insertion and 1 duplication. All aberrations were located in pericentromere region of chromosome 9 with clinical manifestations including congenital heart disease, peculiar facial appearance, paralysis, dysplasia and/or movement disorder. Chromosome polymorphisms were found in 20 patients, most of which had absence of satellites or variation of heterochromatin on chromosome 9. Of 10 bone marrow specimens from children suspected for acute leukemia, chromosome abnormalities were identified in 5 patients.</p><p><b>CONCLUSION</b>Cytogenetic analysis is useful for children featuring multiple congenital abnormalities. Chromosome 9 abnormalities and their clinical relevance should attract more attention.</p>

Cloning, expression and antigenic analysis of VP1-VP4 gene encoding the structural protein of Coxsackie virus A16 / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone and express VP1-VP4 genes encoding the structural proteins of Coxsackie virus A16 and analyze the antigenicity of the expressed recombinant proteins.</p><p><b>METHODS</b>The VP1-VP4 cDNAs were amplified with RT-PCR from the extracted viral RNA and cloned into pMD19-T vectors. The VP1-VP4 genes were inserted to the multi-cloning sites of the plasmid pQE30a, and the protein expressions in E. coli M15 were induced by IPTG. After purification by washing with 8 mol/L urea under denaturing condition, the recombinant proteins were identified by Western blotting and ELISA for their immunogenicity against rabbit antisera of Coxsackie virus A16 and enterovirus 71, respectively.</p><p><b>RESULTS</b>The recombinant VP1-VP4 proteins were highly expressed in E. coli M15. The purified proteins could be recognized by rabbit antiserum of Coxsackie virus A16 and showed cross reactivity with the rabbit antiserum of Enterovirus 71.</p><p><b>CONCLUSION</b>The recombinant Coxsackie virus A16 VP1-VP4 proteins obtained possess good antigenicity.</p>

Analysis of serum neutralizing antibody response in patients with primary dengue virus type 1 infection / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the characteristics and dynamic changes of serum neutralizing antibody response in patients with primary infection of dengue virus type 1 (DENV-1).</p><p><b>METHODS</b>Serum samples were obtained from the same patients with primary infection of DENV-1 within 2 weeks after symptom onset in 2006 and in 2010. A group-specific DENV NS1 capture ELISA-based micro-neutralizing test (ELISA-MNT) capable of detecting neutralizing antibodies against all the 4 serotypes of DENV was used to test the neutralizing antibody titers against DENV in the serum samples. The neutralizing antibody titers against a standard strain and 2 clinically isolated strains of DENV-1 were detected in serum samples collected in 2010.</p><p><b>RESULTS</b>Cross-reactive neutralizing antibody response against all the 4 serotypes of DENV was found in both of the serum samples collected in 2006 and 2010, but the samples collected in 2006 showed stronger cross-reactive neutralizing antibody responses. The neutralizing antibody against DENV-2, rather than the anticipated DENV-1 antibody, had the highest titer in the samples collected in 2006, whereas the antibody against homologous DENV-1 had the highest titer in the samples obtained in 2010. The neutralizing antibody titers against the homologous DENV-1 was significantly higher in samples collected in 2010 (U=86.500, P=0.000), which also demonstrated significantly different neutralizing antibody titers against the 3 different strains of DENV-1 (Χ(2)=12.123, P=0.002).</p><p><b>CONCLUSION</b>The production of cross-reactive neutralizing antibodies between the 4 serotypes of DENV is a characteristic of DENV infection, particularly during early infection, but only the homologous neutralizing antibody increases obviously over time. The titers of the neutralizing antibodies against different strains, even of the same serotype, may differ distinctly.</p>

Identification and priliminary application of monoclonal antibodies against inrisive Aspergillus / 中华检验医学杂志

Objective To screen monoclonal antibodies (mAbs) for early diagnosis of invisive Aspergillus. Methods Monoclonal antibodies against different antigens of Aspergillus fumigatus were produced. The two pairs of combinations of monoclonal antibodies were selected accoring the distinct epitopes and double-antibody sandwich ELISA based on mAbs above were established. The sensitivity and specificity of the methods were analyzed by detecting culture supernatants of clinical isolates and environmental isolatesof Aspergillus. spp, Penicillium Marneffei, Candidas, and serum from animal models and patients. The epitopes recognized by mAbs were identified by immunobotting. Results A total of 32 hybridoma cell lines that stably produced MAbs were obtained. Two double- antibody sandwich ELISAs were established. One method was specific for 19 clinical isolates and environmental isolates of Aspergillus. spp, whereas the other one was specific for the clinical and environmental isolates of Aspergillus fumigatus without cross-reation with other Aspergillus. spp. For the same kind of medium of Aspergillus fumigatus, the sensitivity of the first method was 10 fold higher than the second method. Conclusions The specific mAbs for early diagnosis of invisive Aspergillus were obtained. Antigen recognized by the specific mAbs was mannoprotein with molecular weights of approximately 25 000-75 000. This antigen was potential early diagnostic marker for invasive Aspergillus.

Preventive effects of multi-glycoside of Tripterygium wilfordii on glomerular lesions in experimental diabetic nephropathy / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the preventive effects of multi-glycoside of Tripterygium wilfordii (GTW) on glomerular lesions in experimental diabetic nephropathy (DN).</p><p><b>METHOD</b>The DN model of rats was established with streptozotocin (STZ) and intervened with GTW. In the same time, normal, benazepril, and vehicle control groups were set up. After 8 weeks of oral treatment with GTW (50 mg x kg(-1) BW), benazepril (6 mg x kg(-1) BW), and vehicle (physiological saline), the changes of body weight, urine albumin (UA1b), blood glucose (BG), serum creatinine (Scr), blood urea nitrogen (BUN) and glomerular morphology were examined. In addition, the level of protein expression of alpha-smooth muscle actin (alpha-SMA) and collagen type I in glomeruli was determined by immunofluorescence.</p><p><b>RESULT</b>Both GTW and benazepril reduced UA1b. GTW ameliorated glomerular injury, such as mesangial cell proliferation, alpha-SMA and collagen type I over-expression, in DN model. Compared with benazepril, beneficial effects of GTW on glomerulusclerosis were more significant (total cell number: GTW group 54.44 +/- 2.41, benazepril group microg/67.83 +/- 4.41, P < 0.05; alpha-SMA score: GTW group 1.98 +/- 0.52, benazepril group 2.27 +/- 0.46, P < 0.05; collagen type I score: GTW group 2.11 +/- 0.37, benazepril group 2.88 +/- 0.58, P < 0.05).</p><p><b>CONCLUSION</b>Preventive effects of GTW on glomerular lesion in DN model are related to decreasing UA1b and ameliorating glomerulusclerosis.</p>

Suppressive effects of GTW treatment on infiltration of inflammatory cell in glomeruli in anti-Thy1.1 glomerulonephritis / 中国中药杂志

<p><b>OBJECTIVE</b>To examine inhibition action of multi-glycoside of Tripterygium wilfordii (GTW) on infiltration of inflammatory cell in glomeruli with anti-Thy1.1 glomerulonephritis (anti-Thy1.1 GN), and to clarify its effects on inflammatory in vitro.</p><p><b>METHOD</b>Two types of anti-Thy1.1 GN were induced in rats by a single or two intravenous injections with 500 microg of anti-Thy1.1 mAb 1-22-3. Rats were randomly divided into two groups, the GTW group and control group, and sacrificed on day 7 or on day 42 after induction of anti-Thy1.1 GN. Daily oral administration of different dose of GTW and distilled water as a control was started from 3 days before injection or at the same time of injection till the day of sacrifice. Proteinuria was determined during days 7 or during days 42. Infiltration of macrophage and T lymphocyte in glomeruli and mRNA expression of interleukin (IL)-2 and interferon (IFN)-gamma in renal tissue were examined.</p><p><b>RESULT</b>Increase of infiltration of macrophage in reversible anti-Thy1.1 GN model, glomerular macrophage infiltration and IL-2 mRNA expansion were attenuated by higher dose of GTW (75 mg x kg(-1) x d(-1)), and increased accumulation of activated macrophage and T lymphocyte in irreversible anti-Thy1.1 GN model, accumulation of macrophage and T lymphocyte in glomeruli and mRNA expansion of IL-2 and IFN-gamma were decreased by middling dose of GTW (50 mg x kg(-1) x d(-1)) as well. Proteinuria was significantly ameliorated after GTW administration.</p><p><b>CONCLUSION</b>The findings suggested that different dose of GTW can ameliorate infiltration of inflammatory cell in glomeruli with anti-Thy1.1 glomerulonephritis in vitro by decreasing the expression of IL-2 and IFN-gamma.</p>

Etiological Diagnosis of Invasive Aspergillosis by Monoclonal Antibodies Against Aspergillus fumigatus / 中华医院感染学杂志

OBJECTIVE To study the etiological diagnosis of invasive aspergillosis by the monoclonal antibodies against Aspergillus fumigatus. METHODS An animal model of rabbit invasive aspergillosis was established.The antigen of A.fumigatus in serum was detected by ELISA.The antigen of A.fumigatus in tissue was detected by immunochemistry. RESULTS ELISA assay showed positive 24,48 and 72 hours after infection.Immunochemistry was positive 72 hours after infection. CONCLUSIONS The monoclonal antibodies against A.fumigatus has great potency usage.

Gene-viral vectors: a promising way to target tumor cells and express anticancer genes simultaneously / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To develop a new kind of vector system called gene-viral vector, which combines the advantages of gene and virus therapies.</p><p><b>METHODS</b>Using recombinant technology, an anti-tumor gene was inserted into the genome of replicative virus specific for tumor cells. The cell killing effect, reporter gene expression of the green fluorescence protein, anti-tumor gene expression of mouse interleukin-12 (mIL-12) and replication of virus were observed by the methods of cell pathology, fluorescence microscopy, ELISA and electron microscopy, respectively.</p><p><b>RESULTS</b>A new kind of gene-viral vector system of adenovirus, in which the E1b-55 kD gene was deleted but the E1a gene was preserved, was constructed. The vector system, like the replicative virus ONYX-015, replicated and proliferated in tumor cells but not in normal ones. Our vector had an advantage over ONYX-015 in that it carried different kinds of anti-tumor genes to enhance its therapeutic effect. The reporter gene expression of the green fluorescence protein in tumor cells was much better than the adenovirus vector employed in conventional gene the rapy, and the expression in our vector system was as low as or even less than that in the conventional adenovirus gene therapy system. Similar results were observed in experiments with this vector system carrying the anti-tumor gene mIL-12. Replication and proliferation of the virus carrying the mIL-12 gene in tumor cells were confirmed by electron microscopy.</p><p><b>CONCLUSIONS</b>Gene-viral vectors are new vectors with an anti-tumor gene inserted into the genome of replicative virus specific for tumor cells. Because of the specific replication and proliferation of the virus in tumor cells, expression of the anti-tumor gene is increased hundreds to thousands of times. This approach takes full advantages of gene therapy and virus therapy to enhance the effect on the tumor. It overcomes the disadvantages of conventional gene therapy, such as low transfer rate, low gene expression, lack of target tropism, and low anti-tumor activity. We believe that this is a promising means for future tumor treatment.</p>

Identification and application of monoclonal antibodies against aspergillus fumigatus / 中国免疫学杂志

Objective:To produce monoclonal antibodies(McAb) against aspergillus fumigatus and to establish rapid assay for the measurement of aspergillus fumigatus antigen.Methods:Recombinant galactomannoprotein of aspergillus fumigatus(AFMP1) was used to immune BALB/c mice.Monoclonal antibodies against AFMP1 were produced from hybridoma.Results:Three hybridomas producing antibodies against AFMP1 were obtained.IgG isotypes of three McAb were IgG1,IgG2a and IgG2b.The affinity constants(K) were 1.2?10 10 ,4.56?10 9 and 1.81?10 10 mol/L.The antibodies were proved to be specific for aspergillus fumigatus by Western blot and recognized different epitopes on AFMP1 by the additivity assay.An sandwich enzyme-linked immunosorbent assay(ELISA) to detect AFMP1 was established to produce standard curve which showed linearity between 0.1～60.0 ng/ml with a sensitivity of 0.1 ng/ml.Conclusion:These results show three hybridomas producing high specificity and affinity monoclonal antibodies against AFMP1 and can provide for rapid assay for the measurement of aspergillus fumigatus antigen.