Feasibility study of acupuncture treatment on the miniature pig model of chronic myocardial ischemia / 中国比较医学杂志

Objective To explore the feasibility of needle-embedding therapy in the treatment of chronic myocardial ischemia using a miniature pig model established by placement of an Ameroid constrictor at the left anterior descending branch (LAD) of coronary artery in Bama miniature pigs during surgery. Methods The miniature pig model of chronic myocardial ischemia was established by placement of an Ameroid constrictor at the left anterior descending branch of the left coronary artery in Bama miniature pigs. The pig models were randomly divided into the treatment group (the"Neiguan " group) and the control group (the "Zusanli " group), and were treated with needle- embedding electroacupuncture at the"Neiguan" (PC6) and "Zusanli" (ST36) acupoints, respectively. Myocardial samples were taken at 6 weeks after surgery for light and electron microscopic examinations. Results Gross pathology showed that ischemic area in the myocardium appeared in both experimental groups. The ischemic area in the "Zusanli "group was larger than that of the"Neiguan"group. Histopathology showed that the acupuncture treatment at the"Neiguan"acupoint reduced the ischemic injury in the pig myocardial tissues. Ultrastructural observation of the myocardium showed mitochondrial vacuolization in cardiomyocytes and myocardial fibrosis in both groups. Conclusions Acupuncture therapy at the"Neiguan"acupoint of pericardial channel may exert protective effect on the myocardial ischemia by reducing the ischemia-injury of cardiomyocytes, but can not inhibit the already existed ischemia-induced cardiomyocytic injuries. Our findings suggest that the establishment of miniature pig model of chronic myocardial ischemia by surgically placing an Ameroid constrictor on the left anterior descending branch of left coronary artery and the needle-embedding in acupoints is feasible for the treatment of chronic myocardial ischemia in this pig model.

Application of Time-resolved Fluroimmunoassay for Determination of Furaltadone Metabolite 3-Amino-5-morpholinomethyl-2-oxazolidinone / 分析化学

To detect furaltadone metabolite 3-amino-5-morpholinomethyl-2-oxazolidinone ( AMOZ ) in fish sample, an Eu3+ labeling time-resolved fluoroimmunoassay ( TRFIA ) was developed. The effects of experimental conditions including AMOZA-OVA concentration, dilution of antibody, and reaction time on the sensitivity of TRFIA were explored. The results showed that the optimized assay conditions were as follows:the AMOZA-OVA concentration was 0. 25 μg/mL; the antibody was diluted 5í104 folds, and the competitive reaction time was 50 min. Under optimal conditions, the method showed a detection limit of 0. 01 ng/mL, an IC50 of 0. 26 ng/mL and a linear range (IC20-IC80) of 0. 025-2. 83 ng/mL. The recoveries of AMOZ in fish at three spiked levels ranged from 78 . 0% to 86 . 0%, and the relative standard deviations were less than 15%. Good correlation between the ic-TRFIA and high performance liquid chromatography-tandem mass spectrometry was obtained for spiked food samples. The proposed ic-TRFIA method was suited for the determination of AMOZ residue in food samples.

Indirect Competitive Chemiluminescent Enzyme Immunoassay Method for Determination of Dimethyl Phthalate in Soy Sauce and Liquor / 分析化学

4-Amino dimethyl phthalate as the hapten was coupled to carrier protein and then used to immunize New Zealand rabbits. Polyclonal antibody which showed specific binding to dimethyl phthalate ( DMP) was thus obtained, and on the basis of this, an indirect competitive chemiluminescent enzyme-linked immunoassay ( icCLEIA ) was developed. The experimental parameters of icCLEIA were optimized as follows: the concentration of coating antigen was 50 μg/L, the primary antibody concentration was 92. 5 μg/L, the secondary antibody concentration was 1μg/mL, distilled water (pH 6. 0) was used as diluent solution and the competitive reaction time was 40 min. Under the optimal conditions, the icCLEIA exhibited a linear working range from 0. 74μg/L to 30. 32μg/L with the limit of detection of 0. 29μg/L. The cross-reactivity of thirteen structural analogues was lower than 5%. The recovery of DMP from spiked liquor and soy sauce samples ranged from 80 . 2% to 116 . 0% and the average RSD was less than 3 . 6%. The detection results of the spiked liquor and soy sauce samples were consistent with those by standard gas chromatography-mass spectrometry method. The developed icCLEIA method exhibited a practical potential for detecting DMP residue in food samples.

Direct Competitive Enzyme-Linked Immunosorbent Assay for Detection of Acrylamide in Food Samples / 分析化学

Due to the low molecular weight and simple structure, the production of specific antibodies against acrylamide is unavailable. In this study, a novel hapten was synthesized through the derivatization of acrylamide and 4-mercaptophenylacetic acid. The hapten was then coupled to carrier protein and used to immunize New Zealand rabbits. Polyclonal antibody which showed specific binding to the acrylamide derivative ( hapten) was obtained. The antibody was labeled with horseradish peroxidase ( HRP) and used to develop a direct competitive enzyme-linked immunosorbent assay ( dc-ELISA) . The dc-ELISA was used to determine the content of acrylamide derivative, and then transferred to the content of acrylamide. The assay showed an IC50 value of 45. 49 μg/L, a limit of detection of 3. 0 μg/L and the linear range of 9. 2-195 μg/L for acrylamide. The recovery of acrylamide from spiked food sample was determined ranging from 83 . 6% to 112 . 7%. Good correlations between the results of dc-ELISA and standard HPLC-MS/MS were obtained. The proposed dc-ELISA is suitable for the determination of acrylamide in food samples.

Expression and molecular evolution of recombinant acetylcholinesterase for detection of pesticide residues: a review / 生物工程学报

Acetylcholinesterase (AChE) plays a key role in the pesticide determination. However, the extraction of AChE from natural materials has the disadvantages of low yield, complex purification and poor stability. Therefore, the preparation of recombinant AChE with high performance becomes the hot topic of researchers in recent years. In this article we summarize the progress in the expression of recombinant AChE and the improvement of its analytical characteristic. Finally, we point out that the directed evolution strategy combined with surface display technology is the future trend on improving recombinant AChE activity.

Real-time detection of mast cell degranulation in anaphylactoid reaction / 中国中药杂志

<p><b>OBJECTIVE</b>To establish a new, real time, dynamic and direct optical detection method for mast cell degranulation caused by anaphylactoid reaction.</p><p><b>METHOD</b>A CD63-GFP plasmid was constructed and introduced steadily into rat basophilic leukemia (RBL-2H3) cells. The movements of CD63-GFP, which was located on both the granule membranes and the plasma membranes of RBL cells stimulated by Compound 48/80, were studied by confocal laser scanning microscope (CLSM) and total internal reflection fluorescence microscope (TIRFM) both inside and on the surface of living RBL-2H3 cells.</p><p><b>RESULT</b>Before antigen stimulation, most granules with CD63-GFP hardly moved in RBL cells. However, after antigen stimulation, the granules moved dramatically. They reached the plasma membranes in a few minutes and fused with them instantaneously. The velocity of the granule movement toward the plasma membranes on antigen stimulation was calculated to be 0.05 micron x s(-1).</p><p><b>CONCLUSION</b>Analysis of the movement of each granule provided a new insight into the elementary process of degranulation. The method is rapid, sensitive and reliable, which could be used as a new detection method for anaphylactoid reaction in vitro.</p>

A new evaluation method for tumor cell migration process / 中国药理学通报

Aim To establish a new,multi-parameter,real time and qualitative cell migration evaluation method.Methods Lung cancer cell line A549 was cultured on the glass bottom dish.After treated with different dosages of berberine or Rg3 for 24 hours,several scratching lines at the same dimension were made and observed by Living Cell Working Station.8 observation areas were selected randomly and imaged continuously for 24 hours.Transferred Area(TA),Transferred Distance(TD),Single Cell Transferred Speed(SCTS)and the Cell Division Number among defined area(CDN)were analyzed after getting sequence images.Results The focus stage and the incubation system were sufficient to keep cell proliferation and made it possible for long term observation.Berberine at 25 μmol·L~(-1) and 12.5 μmol·L~(-1) could inhibit the migration of A549(P<0.01).The analysis results of TA,TD,SCTS and CDN were basically coincident.Rg3 at 0.1 mmol·L~(-1) could inhibit SCTS and promote CDN in 6,12 and 24 h(P<0.01),while decrease both TA and TD in 24 hs.Conclusion The method is sensitive,rapid and simple to be applied in the research of tumor metastasis,wound healing and inflammatory response with real time,in-situ and multi-parameters.

Production and Identification of Monoclonal Antibody Against Flumequine and Development of Indirect Competitive Enzyme-Linked Immunosorbent Assay / 分析化学

The hapten of Flumequine(FLU) with four carbon atoms spacer arm(FLUABA) was synthesized and coupled to bovine serum albumin(BSA) as immunogen using activated ester method. Balb/c mice were immunized by the artificial immunogen and the splenocytes of immunized mice were fused with Sp2/0 cells to obtain the monoclonal antibody(McAbs). A hybridoma cell line(DB6-E7) secreting anti-flumequine McAbs was obtained by limited dilution method and screened by indirect enzyme-linked immunosorbent assay(ELISA) using heterogenous coating antigen. The results showed that the subtype of the McAb was IgG_1, and the affinity was 8.19×10~8 L/mol. The haptens of FLU, FLUABA and FLUACA, with different space arm, were separately linked to ovalbumin(OVA) for heterologous or homologous coating antigen. The results of indirect ELISA and indirect competitive ELISA(icELISA) indicated that the heterologous coating antigen could improve the sensitivity of ELISA significantly. By heterologous coating antigen(FLU-OVA), the icELISA showed an IC_(50) value of 26.33 μg/L, LOD of 4.0 μg/L, and the workable range of 8-114 μg/L (IC_(20)-IC_(80)). Cross-reactivity studies showed that the McAbs were quiet specific for FLU, no cross-reactivity(<0.1%) was detected between the obtained McAbs and the quinolones compounds or other structural similarity compounds. The developed icELISA for FLU can satisfy the detection criteria of flumequine in animal food-products.

Construction and expression of anti-clenbuterol single chain Fv recombinant vector / 生物工程学报

To construct the recombinant vector pBV220-scFv and express anti-clenbuterol (CBL) scFv antibody in Escherichia coli, we amplified the scFv gene using plasmid pCANTABSE-CBL as a template, recombined it with pPICZalphaA, then amplified the scFv-His-tag gene from plasmid pPICZalphaA-scFv and linked it with expression plasmid pBV220. We identified the recombinant plasmid by restrictive enzyme digestion, PCR amplification and sequence analysis. Finally, we transformed the recombinant vector into E. coli DH5alpha that was temperature-induced and expressed recombinant protein. We identified the recombinant protein by SDS-PAGE, Western blotting and indirect competitive ELISA. The results show that recombinant plasmid pBV220-scFv contained the inserted fragment with highest homology about 99.8%. The expression of scFv induced by temperature show 37 kD Mw and anti-His-tag mAb recognized-activity by SDS-PAGE and Western blotting respectively, and could competitively combine with CBL, the IC50 is 4.55 ng/mL. The recombinant plasmid pBV220-scFv is constructed and expresses the scFv gene of CBL in E. coli successfully. This study suggests the corresponding immunoassay methods could be set up by the recombinant scFv.