Preliminary investigation in critical care medicine contents and methods for standardized training residents / 中华医学教育探索杂志

Resident standardization training is an important means of clinical physician training in our country. Critical care medicine has important status in the training process. It is the important link to ensure the quality of resident standardization training. Residents should grasp the identification and early detection of critical ill patients. Residents should also get the ability of general basic management for critical condition and the doctor-patient communication ability. In practice, we have explored the training mode of standardized training of resident doctors in critical care medicine by developing detailed training outline, a variety of teaching methods and emphasizing the cultivation of clinical work ability.

Prokaryotic expression, purification and antigenicity identification of mouse VEGFR2 extracellular 1-4 IgG-like domains / 南方医科大学学报

<p><b>OBJECTIVE</b>To obtain 1-4 IgG-like domains of mouse vascular endothelial growth factor receptor 2 (VEGFR2) fusion protein (mVEGFR2D1-4/GST) and identify its antiginicity and biological activity.</p><p><b>METHODS</b>The gene of mVEGFR2D1-4 was amplified by RT-PCR from 14-days embryos of Balb/c mice. The PCR product was cloned into pET-42a prokaryotic expression vector to construct the recombinant plasmid pET-42a-mVEGFR2D1-4, which was transformed into E. coli BL21 (DE3) strain for mVEGFR2D1-4/GST expression. The fusion protein was identified by SDS-PAGE and Western blotting, and the antigenicity of the protein purified by affinity chromatography was characterized by ELISA. The VEGF blocking effect of the purified protein in human umbilical vein endothelial cells (HUVECs) were evaluated in in vitro cell cultures.</p><p><b>RESULTS</b>The mVEGFR2D1-4 gene was obtained, which had an identical sequence to that retrieved in GenBank. The prokaryotic expression vector for mVEGFR2D1-4 was successfully constructed as confirmed by enzyme digestion and DNA sequencing. Both Western blotting and ELISA demonstrated the antigenicity of the purified mVEGFR2D1-4 fusion protein, which obviously blocked the effect of VEGF in promoting HUVEC proliferation in vitro.</p><p><b>CONCLUSION</b>The mVEGFR2D1-4/GST fusion protein obtained shows a strong antigenicity and biological activity to facilitate further study of active anti-tumor immunotherapy targeting VEGFR2.</p>

Influence of electroporation on immunogenicity of the DNA vaccine pVAX-tG250FcGB / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the influence of electroporation on the immunogenicity of the DNA vaccine pVAX- tG250FcGB.</p><p><b>METHODS</b>The DNA vaccine pVAX-tG250FcGB was constructed by inserting the coding gene of tG250 fusion genes into the expression vector pVAX. The DNA vaccine was delivered in BALB/c mouse by electroporation or intramuscular injection, and the induced antigen specific immune responses were compared.</p><p><b>RESULTS</b>The vaccine delivered by electroporation and intramuscular injection both induced immune responses in BALB/c mouse, but electroporation produced an obviously stronger effect than intramuscular injection.</p><p><b>CONCLUSION</b>Electroporation-mediated DNA vaccine delivery can produce strong immune response in mice and is an effective means for studying the immunogenic effect of DNA vaccine pVAX-tG250FcGB.</p>

Construction of an anti-tumor immunogene vaccine pVAX-IL-12-GB and its expression in vivo and in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a novel immunogene therapeutic plasmid that expresses human interleukin-12 (IL-12), granulocyte-macrophage colony stimulating factor (GM-CSF) and B7.1 and observe its expression in vivo and in vitro.</p><p><b>METHODS</b>Human IL-12 gene fragment was cloned into the upper stream of IRES gene in the previously constructed plasmid pVAX-IRES-GM-CSF-B7.1, and the positive recombinant plasmid pVAX-IL-12-GB was transfected into 293T cells via Lipofectamine 2000. The expressions of IL-12 and GM-CSF-B7.1 mRNA and proteins in the transfected cells were assayed by RT-PCR and ELISA, and B7.1 expression was tested by fluorescence-activated cell sorting and immunofluorescence assay. The plasmid pVAX-IL-12-GB was delivered into mouse muscle by electroporation, and the expression of IL-12 in the muscle tissue was identified by immunohistochemistry.</p><p><b>RESULTS</b>Enzyme digestion, PCR and sequence analysis all confirmed successful construction of the recombinant plasmid pVAX-IL-12-GB. IL-12, GM-CSF and B7.1 expressions were all detected in transfected 293T cells, and the expression of IL-12 was also detected in the transfected mouse muscular tissues.</p><p><b>CONCLUSION</b>A novel anti-tumor immunogene vaccine constructed can be expressed both in vivo and in vitro, which facilitates further studies of tumor immunogene therapy.</p>

Prokaryotic expression, purification and antigenicity identification of mouse prostate stem cell antigen / 南方医科大学学报

<p><b>OBJECTIVE</b>To amplify mouse prostate stem cell antigen (mPSCA) gene and construct a recombinant plasmid to obtain mPSCA protein and identify its antigenicity.</p><p><b>METHODS</b>The gene of mPSCA was amplified by RT-PCR from mouse prostate cancer cell line RM-1 with the signal peptide sequence removed. The PCR product was cloned into pET-42a prokaryotic expression vector to construct the recombinant plasmid pET-42a-mPSCA, which was transformed into BL21 (DE3) for mPSCA expression. The fusion protein was purified and identified by SDS-PAGE and Western blotting. The antigenicity of the purified protein was characterized by ELISA.</p><p><b>RESULTS</b>The mPSCA gene was obtained with an identical sequence to that retrieved in GenBank. The prokaryotic expression vector for mPSCA was successfully constructed as confirmed by enzyme digestion and DNA sequencing. Both Western blotting and ELISA demonstrated the antigenicity of the purified mPSCA protein.</p><p><b>CONCLUSION</b>The purified mPSCA obtained possesses good antigenicity, which will facilitate further study of immunotherapy for prostate cancer targeting PSCA.</p>

Prokaryotic expression,purification and identification of human prostate stem cell antigen / 解放军医学杂志

Objective To construct the prokaryotic expression plasmid of human prostate stem cell antigen (PSCA),to induce the expression of GST-PSCA fusion protein in E. coli BL21,and to identify the purified recombinant fusion protein. Methods The fragment of PSCA gene was amplified by PCR,and then cloned into the pGEM-T Easy vector. The transitional plasmid Teasy-PSCA was identified by DNA sequencing. The PSCA gene was digested from the plasmid Teasy-PSCA by restrictive enzyme BamH I and Sal I,and then inserted into the pET42a vector which contains a glutathione s-transterase (GST) tag. Following the double restriction enzyme digestion,the recombinant plasmid pET42a-PSCA was obtained and transformed into E. coli BL21 (DE3). The expression of GST-PSCA fusion protein was induced with IPTG. The recombinant fusion protein was purified by passing over a Glutathione Sepharose 4B column,and was identified by SDS-PAGE and Western blotting. Results The length of amplified PSCA gene fragment was consistent with that expected,and the sequence was correct as exemplified by the PSCA gene reported in GenBank. The result of enzyme digestion indicated that the prokaryotic expression plasmid pET42a-PSCA was successfully constructed. After transformation with pET42a-PSCA and induction with IPTG,the recombinant target protein of about 43kD was obtained. The GST-PSCA fusion protein was correctly identified by SDS-PAGE and Western blotting. Conclusions The prokaryotic expression plasmid of human PSCA gene has been successfully constructed. The GST-PSCA fusion protein may express and be purified in E. coli BL21,and it lays a foundation for further study on the anti-prostate cancer gene vaccine.

Construction of DC-SIGN eukaryotic expression vector and establishment of BHK21 cell line stably transfected by the recombinant vector / 解放军医学杂志

Objective To construct a eukaryotic expressing vector harboring human DC-SIGN, and establish a BHK21 cell line stably and highly expressing DC-SIGN. Methods The DC-SIGN gene fragment which contained Not I and BamH I sites was amplified by PCR from pUNO-hDCSIGN1Aa plasmid, digested with Not I and BamH I, and then cloned into an eukaryotic expression vector pIRES-neo to construct eukaryotic expression vector pIRES-neo-DC-SIGN. The recombined plasmid was identified with Not I and BamH I enzyme digestion and sequencing, the latter was then transfected to BHK21 cells by LipofectamineTM 2000. After screening culture by G418, BHK21 cell line stably expressing DC-SIGN was established. The expression of DC-SIGN was identified by flow cytometry, Western blotting and immunofluorescence method. Results The gene sequence of DC-SIGN was consistent with that of design. PCR and double enzyme digestion analysis showed that the recombinant plasmid pIRES-neo-DC-SIGN was constructed successfully. After transfection, positive clones were selected with G418. After limiting dilution assay, BKH21 cell lines stably expressing DC-SIGN were established. The detection result of flow cytometry showed that the expression ratio of DC-SIGN positive clones was close to 90%. The result of immunofluorescence displayed that the expression of DC-SIGN was mostly located on the surface of cell membrane. Western blotting displayed the specific band of DC-SIGN protein. It showed that the BHK21 cells stably expressing DC-SIGN were successfully established. Conclusion DC-SIGN eukaryotic expression vector has been successfully constructed. The successful establishment of BHK21 cell lines which can stably express DC-SIGN provides a substantial foundation for further study on the DC targeting vaccines.

Construction and expression of human anti-HBs-IFN fusion gene / 解放军医学杂志

Objective To construct eukaryotic expression plasmid pEE14.1-dsFv?pr+,and detect the expression of the recombined gene in eukaryotic CHO-K1 cells.Methods The cationic DNA fragment was cloned into the 3' of VH gene by overlapping extension PCR,and the 6?His tab was inserted to the 3' of VL and human IFN-? gene by the same way.The above mentioned recombinant VH and VL genes were inserted into a pCI-GPI vector first,and then cloned into the pEE14.1 vector to construct the recombinant plasmid pEE14.1-dsFv?pr+.Finally,the recombinant plasmid was transfected into the CHO-K1 cells by LipofectamineTM 2000,and the expression was detected by RT-PCR,ELISA and Western blotting.Results The enzyme digestion and sequencing analysis showed that the recombinant plasmid was successfully constructed.RT-PCR showed that only the cells with transfected plasmid can generate the specific 1700bp fragment.ELISA analysis showed that the production of IFN-?expressed in the supernatant of transfected cells was about 1.1ng/ml.Also,Western blotting could reveal the characteristic band of HBsAg dsFv?pr+ protein.Conclusion The antibody targeting to human IFN-?genes has been successfully expressed in a single open reading frame.Changing the electricity of the antibody may provide the necessary condition for the study of the a new type of anti-HBV drug in nanoscale in the future.