脉冲电磁场影响人骨髓基质干细胞缝隙连接通讯的实验研究

目的研究脉冲电磁场(PEMFs)对人骨髓基质干细胞(hBMSCs)缝隙连接所介导细胞间通讯(GJIC)的影响。方法透射电镜观察BMSCs超微结构,应用荧光漂白恢复(FRAP)技术,通过激光共聚焦显微镜检测hBM-SCs经PEMFs刺激后GJIC的功能变化。结果经PEMFs刺激后的hBMSCs,平均荧光漂白恢复率为(64.12±0.83)%,较对照组犤(35.26±0.76)%犦有显著性增加(P<0.05)。结论PEMFs刺激能促进hBMSCs的缝隙连接通讯功能。     

Evaluation of high protein intake to improve clinical outcome and nutritional status for patients with burns: a systematic review

Background and aimPatients with severe burns undergo a local and systemic response to the injury. As part of this response the patient becomes hypermetabolic. Current guidelines advise high protein intakes to counteract the catabolic response to burns, but this appears to be based on minimal experimental evidence. Hence the aim of this review was to examine the evidence for improvements in nutritional status and clinical outcome with the administration of high protein intakes for patients with burns.MethodsEight databases were searched for clinical trials with burn patients receiving two or more levels of protein intake at or above the level recommended for healthy individuals (0.75 g/kg/d) and presenting results for at least one of the following pre-defined outcomes: nitrogen balance, length of stay, weight change, survival, physical therapy index, protein fractional synthetic rate, immunological measurements, bacteraemic days, systemic antibiotic days and net protein synthesis.ResultsSix studies were included, 4 of which were randomized trials. All had major methodological limitations, in particular none was blinded. There was too much heterogeneity in study design, patient characteristics and the timing and magnitude of the interventions to justify formal meta-analysis. There was no reliable evidence of improvement in nitrogen balance, but there was some evidence of increased weight gain on higher protein diets. One small study reported an increase in survival and significant improvements in infection rates and some indicators of immune function in children. Length of stay was not significantly improved. There was weak evidence of an improvement in muscle strength and endurance but no significant increase in protein synthesis in muscle or skin, or net protein synthesis in the whole body.ConclusionThere is currently only very weak evidence to justify administering high protein diets to patients following burns.     

Nano-hydroxyapatite modulates osteoblast lineage commitment by stimulation of DNA methylation and regulation of gene expression

Hydroxyapatite (HA) is the primary structural component of the skeleton and dentition. Under biological conditions, HA does not occur spontaneously and therefore must be actively synthesized by mineralizing cells such as osteoblasts. The mechanism(s) by which HA is actively synthesized by cells and deposited to create a mineralized matrix are not fully understood and the consequences of mineralization on cell function are even less well understood. HA can be chemically synthesized (HAp) and is therefore currently being investigated as a promising therapeutic biomaterial for use as a functional scaffold and implant coating for skeletal repair and dental applications. Here we investigated the biological effects of nano-HAp (10 × 100 nm) on the lineage commitment and differentiation of bone forming osteoblasts. Exposure of early stage differentiating osteoblasts resulted in dramatic and sustained changes in gene expression, both increased and decreased, whereas later stage osteoblasts were much less responsive. Analysis of the promoter region one of the most responsive genes, alkaline phosphatase, identified the stimulation of DNA methylation following cell exposure to nano-HAp. Collectively, the results reveal the novel epigenetic regulation of cell function by nano-HAp which has significant implication on lineage determination as well as identifying a novel potential therapeutic use of nanomaterials.     

Immunohistochemical localization of steroid receptor coactivators in chondrosarcoma: An in vivo tissue microarray study

Chondrosarcoma is the second most common type of primary bone malignancy following up osteosarcoma, characterized by resistance to conventional chemotherapeutic agents and radiation regimens. The p160 family members steroid receptor coactivator-1 and -3 (SRC-1 and SRC-3) have been implied in the regulation of cancer growth, migration, invasion, metastasis and chemotherapeutic resistance; but we still lack detailed information about the levels of SRCs in chondrosarcoma. In this study, expression of SRC-1 and SRC-3 in chondrosarcoma was examined by immunohistochemistry with tissue microarrays; the four score system (0, 1, 2 and 3) was used to evaluate the staining. The results showed that there were no gender-, site- or age-differences regarding the expression of SRC-1 or SRC-3 (p > 0.05); organ (bone or cartilage) -differences were only detected for SRC-1 but not SRC-3 (p < 0.05). Significant higher levels of SRC-1 and SRC-3 were detected in MDC and PDC when compared to WDC. Our study clearly demonstrated differentiation-dependant expression of SRC-1 and SRC-3 in chondrosarcoma, may be novel targets for the prognosis and/or treatment of chondrosarcoma, would have opened a new avenue and established foundation for studying chondrosarcoma.     

复合血管内皮祖细胞的组织工程骨修复兔桡骨缺损的实验研究

目的评价复合血管内皮祖细胞（EPCs）的组织工程骨修复兔桡骨大段缺损的效果。方法选用68只新西兰大耳白兔，随机分为三组。制成桡骨中段15mm骨缺损模型，各组植入不同材料，实验组（EPCs组）：植入EPCs＋经成骨诱导的骨髓基质干细胞（BMSCs）＋脱钙骨基质（DBM）；对照组：植入BMSCs＋DBM；阴性对照组：单纯植入DBM。术后3d，2、4、8、12、16周行X线片、组织学光镜、透射电镜观察及12、16周生物力学测试。结果实验组的成骨活跃程度、骨愈合速度均明显优于对照组。12周实验组抗扭强度[（5．57±0．13）MPa]与正常对照组无差异[（5．44±0．26）MPa]，明显强于对照组[（4．72±0．58）MPa]，差异有统计学意义（P〈0．05）；16周实验组抗扭强度[（8．57±2．10）MPa]明显强于对照组[（5．43±0．22）MPa）1和正常对照组[（5．44±0．26）MPa）]，差异均有统计学意义（P〈0．05）；实验组与对照组各项指标明显优于阴性对照组，差异均有统计学意义（P〈0．05）。结论复合EPCs的组织工程骨骨诱导能力强，能促进骨愈合，是修复大段骨缺损的有效方法。     

Endometrial Ablation: Long-Term Outcome

hysteroscopic endometrial ablation is an effective treatment for the management of chronic menorrhagia unresponsive to medical therapy, with acceptably low complication rates and high patient satisfaction rates when assessed at long term follow-up. Endometrial ablation compares favourably with hysterectomy in randomized trials comparing efficacy and cost. Global endometrial ablation devices are currently being evaluated and may Prove useful alternatives to hysteroscopis endometrial ablation surgery in selected patients. Good patient selection may optimize outcome with hysteroscopis endometrial ablation surgery. Endometrial pretreatment does not improve long term outcome. Further studies of long term follow-up are necessary to assess the efficacy of this procedure.     

骨外固定加压治疗胫骨开放性骨折(附107例报道)

目的评估骨外固定治疗胫骨开放性骨折的疗效。方法107例胫骨开放性骨折骨外固定加压治疗。将伤口彻底清创后，交叉穿针骨外固定。稳定性骨折复位后可直接加压固定。对不稳定骨端和粉碎骨块(片)整复后先用1～3枚螺钉固定，不剥离骨膜，使分离的骨折端和骨块互相靠拢以增强骨折端的稳定性。小腿中上段软组织缺损选用腓肠肌内侧头或腓肠肌肌皮瓣转位修复，中下段用邻近筋膜皮瓣覆盖。结果107例中94例伤口一期愈合(87．8％)。骨折愈合时间4．5～6．5个月，平均5个月。结论骨外固定加压是治疗胫骨开放性骨折较为理想的方法，其固定确切、操作简单，对骨生长的生物学及生物力学环境影响小，有利于骨折愈合：钢针远离骨折端，对骨端的血循环干扰小。     

The 3D structure of the collagen fibril network in human trabecular bone: Relation to trabecular organization

Trabecular bone is morphologically and functionally different from compact bone at the tissue level, but both are composed of lamellae at the micrometer-scale level. We present a three-dimensional study of the collagenous network of human trabecular lamellar bone from the proximal femur using the FIB-SEM serial surface view method. The results are compared to human compact lamellar bone of the femoral shaft, studied by the same method. Both demineralized trabecular and compact lamellar bone display the same overall structural organization, namely the presence of ordered and disordered materials and the confinement of the canalicular network to the disordered material. However, in trabecular bone lamellae a significant proportion of the ordered collagen fibril arrays is aligned with the long axis of the trabecula and, unlike in compact bone, is not related to the anatomical axis of the whole femur. The remaining ordered collagen fibrils are offset from the axis of a trabecula either by about 30° or 70°. Interestingly, at the tissue scale of millimeters, the most abundant angles between any two connected trabeculae — the inter-trabecular angles - center around 30° and 70°. This implies that within a framework of interconnected trabeculae the same lamellar structure will always have a significant component of the fibrils aligned with the long axes of connected trabeculae. This structural complementarity at different hierarchical levels presumably reflects an adaptation of trabecular bone to function.     

miR-135a modulates tendon stem/progenitor cell senescence via suppressing ROCK1

Tendon stem/progenitor cell (TSPC) senescence may lead to age-related tendon disorders and impair tendon regeneration and replacement capacity in humans. However, the mechanisms governing TSPC aging and degeneration remain obscure. Recently, it has been reported that Rho-associated coiled-coil protein kinase 1 (ROCK1) might be a key player in TSPC aging process. miRNAs are also involved in cellular senescence. In this study, whether miRNAs modulate senescence of TSPCs through targeting ROCK1 was evaluated. We found that miR-135a, which directly binds to the 3′-untranslated region of ROCK1, is significantly downregulated in aged compared with young TSPCs. Overexpression of miR-135a in young TSPCs suppresses senescence, promotes proliferation, and induces migration and tenogenic differentiation, whereas suppression of miR-135a in aged TSPCs has the opposite effects. By gain-of-function and loss-of-function studies, we confirmed that ROCK1 mediates the effects of miR-135a in TSPCs. Taken together, our data suggest that miR-135a plays an important role in TSPC senescence via targeting ROCK1.     

注重慢性踝关节不稳的诊断和治疗

<正>踝关节不稳指踝关节内外侧及下胫腓联合等维持踝关节稳定的重要结构受损,导致踝关节频繁内翻或外翻性损伤所引发的踝关节长期慢性疼痛和创伤性关节炎以及功能障碍,也称为踝关节不稳综合征。踝关节不稳主