Effect of Wnt3a-transduced bone marrow mesenchymal stem cells on the proliferation of T lymphocytes / 中华血液学杂志

<p><b>OBJECTIVE</b>To observe the effect of Wnt3a-transduced mouse bone marrow mesenchymal stem cells (MSC) on the proliferation of T lymphocytes.</p><p><b>METHODS</b>MSC were isolated from C57BL/6 mouse bone marrow and expanded in vitro, then identified by flow cytometry and their differentiation capacity into osteocytes and adipocytes were determined. Recombinant plasmids containing Wnt3a gene, were transfected with lipofectamine into HEK293 cells by the AdEasy system. Viral particles were collected to infect MSC and adenovirus vector expressing GFP (Ad-GFP) was used as control. The expression of GFP in MSC was observed using fluorescence microscopy and the protein levels of Wnt3a and β-catenin were determined by Western blot. Wnt3a-transduced and Ad-GFP transduced MSC were separately cocultured with spleen lymphocytes stimulated by ConA, at the ratio of 1:100, 1:50 or 1:10 respectively. The proliferation rate of T lymphocytes was estimated by Cell Cout Kit-8 (CCK-8) and the level of cytokine by ELISA.</p><p><b>RESULTS</b>FCM analysis showed that the MSC were highly positive for CD90.2, CD44 and negative for CD34, CD45, they could differentiate into osteoblasts and adipocytes after induction; The titer of recombinant adenoviruses was up to 1 × 10(10) pfu/ml. After infected with the adenoviruses, MSC had the strongest GFP expression at 72 h and the efficiency of infection was 50%-60%. The expressions of Wnt3a and β-catenin protein in the Wnt3a-transduced MSC were significantly increased. MSC could suppress the proliferation of T lymphocytes in a dose-dependent manner. When MSC cocultured with spleen lymphocytes at 1:10 ratio, T lymphocyte proliferation rate and the level of IFN-γ were (55.41 ± 1.75)% and (326.70 ± 14.41) pg/ml respectively in Ad-GFP transduced MSC group, while in Wnt3a-transduced MSC group, they were (37.27 ± 2.66)% and (218.80 ± 12.93) pg/ml respectively. There was no effect on the production of IL-2.</p><p><b>CONCLUSION</b>Compared to Ad-GFP transduced MSC, Wnt3a-transduced MSC exhibit a more potent inhibitory effect on the proliferation of T lymphocytes.</p>

Case-clinical studies on the applicator of external fixator in the open tibia and fibula fractured patients with multiple trauma / 中国骨伤

<p><b>OBJECTIVE</b>To explore the effects of early external fixation for open tibia and fibula fractures on the treatment and prognosis of severe multiple injuries.</p><p><b>METHODS</b>Seventy-three patients were reviewed in the study. According to the surgical methods for tibia and fibula fractures, the patients with severe multiple injuries were divided into 2 groups: 42 patients in the treatment group, including 31 males and 11 females, with an average age of 40.2 years; 31 patients in the control group, ineluding 22 males and 9 females, with an average age of 42.6 years. The patients in treatment group were treated urgently with debridement, diaplasis and fixation with external fixator, and patients in control group were treated urgently with debridement, calcaneal traction or gypsum external fixation. The incidence rate and mortality of ARDS and MODS, wound infection rate, wound healing time, and fracture healing time between the 2 groups was compared.</p><p><b>RESULTS</b>The incidence rate and mortality of complications (ARDS) had significant differences between the 2 groups, those in the treatment group were lower than those in the control group (P < 0.05). There were significant decreases in the infection rate and wound healing time in the treatment group.</p><p><b>CONCLUSION</b>External fixation for severe multiple injuries with open tibia and fibula fracture has been proved to be good, which can significantly reduce the mortality and incidence rate of complications and wound infection rate, promote wound healing.</p>