ABSTRACT
BACKGROUND@#In previous studies, we succeeded in repairing a long bone defect with tissue-engineered periosteum (TEP), fabricated by incorporating rabbit mesenchymal stem cells with small intestinal submucosa. In this study, we investigated the feasibility of allogeneic irregular bone defect repair using TEP. @*METHODS@#We performed a subtotal resection of the scapula in 36 rabbits to establish a large irregular bone defect model. The rabbits were then randomly divided into three groups (n = 12 per group) and the defects were treated with TEP (Group 1), allogeneic deproteinized bone (DPB) (Group 2) or a hybrid of TEP and DPB (Group 3). At 4, 8, and 12 weeks after surgery, the rabbits were sacrificed, and the implants were harvested. X-ray radiographic and histological examinations were performed to detect bone healing. Ink-formaldehyde perfusion was introduced to qualitatively analyze vascularization in TEP engineered new bone. @*RESULTS@#The repair of scapular defects was diverse in all groups, shown by radiographic and histological tests. The radiographic scores in Group 1 and Group 3 were significantly higher than Group 2 at 8 and 12 weeks (p < 0.05).Histological scores further proved that Group 1 had significantly greater new bone formation compared to Group 3 (p < 0.05), while Group 2 had the lowest osteogenesis at all time-points (p < 0.001). Ink-formaldehyde perfusion revealed aboundant microvessels in TEP engineered new bone. @*CONCLUSION@#We conclude that TEP is promising for the repair of large irregular bone defects. As a 3D scaffold, DPB could provide mechanical support and a shaping guide when combined with TEP. TEP engineered new bone has aboundant microvessels.
ABSTRACT
BACKGROUND@#In previous studies, we succeeded in repairing a long bone defect with tissue-engineered periosteum (TEP), fabricated by incorporating rabbit mesenchymal stem cells with small intestinal submucosa. In this study, we investigated the feasibility of allogeneic irregular bone defect repair using TEP. @*METHODS@#We performed a subtotal resection of the scapula in 36 rabbits to establish a large irregular bone defect model. The rabbits were then randomly divided into three groups (n = 12 per group) and the defects were treated with TEP (Group 1), allogeneic deproteinized bone (DPB) (Group 2) or a hybrid of TEP and DPB (Group 3). At 4, 8, and 12 weeks after surgery, the rabbits were sacrificed, and the implants were harvested. X-ray radiographic and histological examinations were performed to detect bone healing. Ink-formaldehyde perfusion was introduced to qualitatively analyze vascularization in TEP engineered new bone. @*RESULTS@#The repair of scapular defects was diverse in all groups, shown by radiographic and histological tests. The radiographic scores in Group 1 and Group 3 were significantly higher than Group 2 at 8 and 12 weeks (p < 0.05).Histological scores further proved that Group 1 had significantly greater new bone formation compared to Group 3 (p < 0.05), while Group 2 had the lowest osteogenesis at all time-points (p < 0.001). Ink-formaldehyde perfusion revealed aboundant microvessels in TEP engineered new bone. @*CONCLUSION@#We conclude that TEP is promising for the repair of large irregular bone defects. As a 3D scaffold, DPB could provide mechanical support and a shaping guide when combined with TEP. TEP engineered new bone has aboundant microvessels.
ABSTRACT
Objective To screen specific mass peaks (SMP) of carbapenem-resistant Klebsiella pneumoniae (CRKP) by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and perform rapid homology analysis on CRKP based on SMP.Methods 76 strains of CRKP with multilocus sequence typing (MLST) were selected from a microbiology laboratory of a hospital, 52 strains were for establishment of method and 24 strains were for validation of method. Five different criteria for selecting SMP of CRKP were set, SMP of different ST-type were screened according to different criteria, CRKP was typed based on screened SMP, criterion with the highest coincidence rate of MLST results was determined as the best criterion. Twenty-four CRKP strains were typed according to the specific peaks screened through best criteria, accuracy of SMP typing method was verified, and was compared with principal component analysis (PCA) and main spectra profile (MSP) cluster analysis in mass spectrometer software.Results According to standard 2 (①signal-to-noise ratio [S/N]≥4, ②S/N ratio≥1.5, ③coefficient of variability [CV≤40％]), 45 SMP were selected from 52 strains of CRKP strains, 29 strains of CRKP were typed by SMP, with the highest coincidence rate (82.8％) with MLST, which was determined as the best criterion. Another 24 CRKP strains were typed according to SMP screened based on this criterion, and the coincidence rate with MLST was 83.3％. The coincidence rate between PCA cluster analysis and MLST was only 66.7％, consistency between MSP clustering analysis and MLST was poor, and it didn't conform to the grouping trend of ST typing.Conclusion MALDI-TOF MS can select SMP of CRKP of different ST, which can be used for rapid homology analysis on CRKP, provide basis for surveillance and control of outbreak of healthcare-associated infection.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the regulating effect of miR-202 on B cell-activating factor, and check whether the regulation influences the growth of multiple myeloma cells.</p><p><b>METHODS</b>The potential binding sites of BAFF for miR-202 were predicted using bioinformatics software. Luciferase reporter gene analysis was used to evaluate the regulatory effect of miR-202 on BAFF. Human multiple myeloma U266 cells were transfected with has-miR-202-mimics, has-miR-202-inhibitor, siBAFF and their negative controls, respectively. After above treatments, BAFF mRNA and protein levels were detected by real-time PCR and Western blot analysis, and the proliferation and apoptosis in the multiple myeloma (MM) cells were examined by WST-1 and annexin V-FLUOS assay, respectively.</p><p><b>RESULTS</b>The BAFF mRNA expression levels in the untransfected group, has-miR-202-3P-mimics transfected group, has-miR-202-3P-inhibitor transfected group and siBAFF transfected group were 1.040 ± 0.057, 0.573 ± 0.073, 1.205 ± 0.097 and 0.368 ± 0.052, respectively. BAFF mRNA expressions in U266 cells transfected with has-miR-202-3P-mimics and siBAFF were significantly decreased compared with that in the untransfected group (P < 0.05). The BAFF protein expression level of each group was consistent with the mRNA assay result. The absorbance value in 450 nm of the untransfected group, has-miR-202-3P-mimics transfected group, has-miR-202-3P-inhibitor transfected group and siBAFF transfected group were 1.063 ± 0.052, 0.714 ± 0.045, 0.936 ± 0.066 and 0.764 ± 0.053, respectively. In comparison with the untransfected group, the absorbance value at 450 nm of has-miR-202-3P-mimics and siBAFF transfected groups was significantly reduced (P < 0.05). The cell apoptosis rates of untransfected group, has-miR-202-3P-mimics transfected group, has-miR-202-3P-inhibitor transfected group and siBAFF transfected group were 26.2%, 49.6%, 21.1% and 30.7%, respectively. Therefore, the cell apoptosis rate of has-miR-202-3P-mimics transfected group was significantly increased than that of the untransfected group (P < 0.05). p-JNK protein expression level was decreased in the has-miR-202-3P-mimics transfected cells.</p><p><b>CONCLUSIONS</b>MiR-202 can inhibit the proliferation and induce apoptosis in MM cells via regulating BAFF. JNK/SAPK signaling pathway is involved in the regulation of BAFF by miR-202.</p>