Establishment of a bioluminescent MDA-MB-231 cell line for in vivo imaging of human triple-negative breast cancer xenograft / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a bioluminescent MDA-MB-231 cell line which can stably express luciferase and green fluorescent protein to allow bioluminescent imaging in nude mouse models bearing human triple-negative breast cancer xenografts.</p><p><b>METHODS</b>The lentivirus carrying luc2, eGFP and neo fusion genes were packaged in 293T cells via calcium phosphate co-precipitation. Human triple-negative breast cancer cell line MDA-MB-231 was infected by the lentivirus, and the positive cell clones were tested for eGFP and luc2 expressions by fluorescence microscopy and Xenogen IVIS200 bioluminescent imaging system, respectively. MTT assay, transwell invasion assay and wound healing assay were performed to evaluate the changes in the proliferation, invasion and migration abilities of the infected cells. The cells were then orthotopically implanted into the right second mammary fat pat of female BALB/c nude mice. The tumor growth was monitored by the in vivo imaging system every week, and the tumor tissues were harvested to evaluate the in vivo stability and tumorigenicity of the modified cells using cryosection and HE staining.</p><p><b>RESULTS</b>The lentivirus-infected MDA-MB-231cells could stably express luc2 and eGFP, and the luciferase activity reached 9689 phontons/s/per cell. No significant changes occurred in the biological activities of the lentivirus-infected MDA-MB-231 cells. We successfully established the nude mouse model bearing orthotopically implanted human triple-negative breast cancer cells.</p><p><b>CONCLUSION</b>The modified MDA-MB-231 cell line can be detected sensitively at the primary implantation site and distant metastasis site in nude mice, which provides a convenient and sensitive platform for the research of metastatic mechanism and new antitumor drugs of human triple-negative breast cancer. The combination of eGFP and luc2 is superior to single reporter gene.</p>

Influence of implant-abutment connection mode on stress distribution in peri-implant bone / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of butt joint connection and platform switching design of implant-abutment connection on the stress distribution in peri-implant bone.</p><p><b>METHODS</b>Three-dimensional finite element models of implant-supported mandibular first molar with different implant-abutment connections were computed by COSMOSM 2.85. Traditional butt joint connection was used in model A and platform switching design in model B. Loading conditions were a vertical load of 200 N and inclined load of the same magnitude at 45 degrees to the vertical axis of the implant. Stress distribution in peri-implant bone and von Mises stresses at the same point of buccal and lingual implant-bone interfaces in two models were compared.</p><p><b>RESULTS</b>Stresses concentrated in peri-implant cortical bone at the neck of implants on the buccal and lingual sides; maximum von Mises stresses under inclined load were higher than those under vertical load. Maximum von Mises stress in bone was 11.61 MPa in model A and 7.15 MPa in model B under vertical load, and 22.07 MPa in model A and 11.87 MPa in model B under inclined load respectively. Von Mises stresses decreased as the distance from implant-abutment junction increased and the most obvious change occurred at the interface between cortical bone and spongy bone. Von Mises stresses at the same points of buccal and lingual implant-bone interfaces in model A were higher than those in model B.</p><p><b>CONCLUSIONS</b>Compared with butt joint connection, platform switching design improved the stress distribution and decreased the maximum stresses in peri-implant bone around implant cervix.</p>

Effect of crestal rotated flap on esthetics of peri-implant soft tissues in anterior maxilla / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the height of interdental papillae around single-tooth implants in the anterior maxillae after exposure of implant using crestal rotated flap.</p><p><b>METHODS</b>The study comprised 34 implants in the anterior maxillae from 32 patients. All implants were uncovered by use of crestal rotated flap technique. Impressions were taken before and after stage 2 surgery, and stone models were used to evaluate the change of papillae height. The gingival papillae index around single-tooth implants was compared before and after the surgery.</p><p><b>RESULTS</b>The average increase in papillae height was (0.77 +/- 0.25) mm, which was statistically significant with analysis of a paired t test (P < 0.05). The change of gingival papillae index showed no significant difference using statistical analysis of rank sum test (P > 0.05). The lower the gingival papillae index was before the surgery, the less the papillae height increased after the surgery.</p><p><b>CONCLUSIONS</b>The main advantages of the crestal rotated flap technique are simplicity and predictability, and it consistently provides high papillae for the maxillary implants.</p>

The immunoregulatory effect of TLSF_(JM) on the levels of IP3、Ca~(2+) in activated T cells and the expression of Fos Protein / 中国免疫学杂志

The immunoregulatory effect of TLSF_(JM) on the levels of IP3,Ca~(2+) in activated T cells andthe expression of Fos protein was investigated by ABC immunohistochemistry technique and Fu-ra-2/AM labelled T cells and anion-exchange chromatography techniques in this paper.The re-sults showed that TLSF_(JM) can the same time,it can strongly inhibit the levels of IP3、Ca~(2+) in ac-tivated T cells.