Repair of experimentally induced femoral chondral defect in a rabbit model using Lyophilized growth promoting factor extracted from horse blood platelets (L-GFequina)

Lyophilized equine platelet derived growth factors (LGF) is a novel advanced platelet rich protein growth factor. It has been successfully applied in various fields of regenerative medicine to treat a variety of inflammatory and degenerative musculoskeletal conditions. Our study aimed to evaluate the efficacy of intraarticularly injected LGF for the remedy of articular cartilage injury, commonly characterized by progressive pain and loss of joint function in osteoarthritic rabbits. Full-thickness cylindrical cartilage defects were generated in both femoral condylar articular surfaces in twenty rabbits. The left joint of all animals was injected with the adjuvant as a self-control negative, while the right joint was injected by LGF. Four- and eight-weeks post-surgery, the femoral condyles were harvested, and assessed grossly, microscopically and immunohistochemically. Cytokines (TNF-α, IL-1β, PDGF and TGF-β1) contents of the chondral defects were quantified by ELISA as well as the gene expression of Col I and Col II via RT-qPCR. The LGF treated defects showed significant higher ICRS (International cartilage repair society) healing scores of cartilaginous regeneration with a significant higher histological healing score on using O'Driscoll histological scoring system. Additionally, LGF significantly lowered the levels of the pro-inflammatory cytokines TNF-α and IL-1β. It also significantly increased the anabolic and angiogenic growth factors (PDGF and TGF-β1), and significantly elevated the expression of chondrogenic-related marker genes; Col I and Col II. The current study reveals that LGF improves chondral healing and thus it can be a superior nominee as an adjunctive therapy to positively influence regeneration of chondral defects in osteoarthritic patients.     

The Prevalence of Osteoporosis in China,a Nationwide,Multicenter DXA Survey

A number of studies investigated the distribution of BMD values and the prevalence of osteoporosis in China, but their findings varied. Until now, a BMD reference database based on uniform measurements in a large-scale Chinese population has been lacking. A total of 75,321 Chinese adults aged 20 years and older were recruited from seven centers between 2008 and 2018. BMD values at the lumbar spine (L₁–L₄), femoral neck, and total femur were measured by GE Lunar dual-energy X-ray absorptiometry systems. BMD values measured in each center were cross-calibrated by regression equations that were generated by scanning the same European spine phantom 10 times at every center. Cubic and multivariate linear regression were performed to assess associations between BMD values and demographic variables. Sex-specific prevalence of osteoporosis was age-standardized based on the year 2010 national census data for the Chinese population. The sex-specific BMD values at each site were negatively associated with age, positively associated with body mass index levels, and lower in the participants from southwest China than in those from other geographic regions after multivariate adjustment. Furthermore, BMD values at the femoral neck and total femur decreased with the year of BMD measurement. The peak BMD values at the lumbar spine, femoral neck, and total femur were 1.088 g/cm², 0.966 g/cm², and 0.973 g/cm², respectively, for men, and 1.114 g/cm², 0.843 g/cm², and 0.884 g/cm², respectively, for women. The age-standardized prevalence of osteoporosis at the spine or hip was 6.46% and 29.13% for men and women aged 50 years and older, respectively. Currently a total of 10.9 million men and 49.3 million women in China are estimated to have osteoporosis. In our national examination of BMD, we found that BMD values differed by demographic characteristics. We estimated the age-standardize prevalence of osteoporosis in China to be 6.46% and 29.13% respectively, for men and women aged 50 years and older.     

In vitro antibacterial properties of magnesium metal against Escherichia coli,Pseudomonas aeruginosa and Staphylococcus aureus

Bacterial infections are a costly sequela in any wound. The corrosion properties of 0.15, 0.30, 0.45 and 0.60 g of Mg metal were determined in Mueller–Hinton broth by serially measuring the Mg²⁺ concentrations and pH over 72 h. In addition, the effect of Mg metal, increased Mg²⁺ concentration and alkaline pH on the in vitro growth of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were evaluated in three separate experiments. The primary outcome measure for culture studies was colony-forming units/ml compared to appropriate positive and/or negative controls. Regardless of the mass of Mg added, there was a predictable increase in pH and Mg²⁺ concentration. The addition of Mg and an increase of pH resulted in antibacterial effects similar to the fluoroquinolone antibiotic; however, a simple increase in Mg²⁺ concentration alone had no effect. The results demonstrate an antibacterial effect of Mg on three common aerobic bacterial organisms, the mechanism of which appears to be an alkaline pH.     

Does treatment delay for blunt cerebrovascular injury affect stroke rate?: An EAST multicenter study

BackgroundThe purpose of this study was to analyze injury characteristics and stroke rates between blunt cerebrovascular injury (BCVI) with delayed vs non-delayed medical therapy. We hypothesized there would be increased stroke formation with delayed medical therapy.MethodsThis is a sub-analysis of a 16 center, prospective, observational trial on BCVI. Delayed medial therapy was defined as initiation >24 hours after admission. BCVI which did not receive medical therapy were excluded. Subgroups for injury presence were created using Abbreviated Injury Scale (AIS) score >0 for AIS categories.Results636 BCVI were included. Median time to first medical therapy was 62 hours in the delayed group and 11 hours in the non-delayed group (p < 0.001). The injury severity score (ISS) was greater in the delayed group (24.0 vs the non-delayed group 22.0, p <  0.001) as was the median AIS head score (2.0 vs 1.0, p <  0.001). The overall stroke rate was not different between the delayed vs non-delayed groups respectively (9.7% vs 9.5%, p = 1.00). Further evaluation of carotid vs vertebral artery injury showed no difference in stroke rate, 13.6% and 13.2%, p = 1.00 vs 7.3% and 6.5%, p = 0.84. Additionally, within all AIS categories there was no difference in stroke rate between delayed and non-delayed medical therapy (all N.S.), with AIS head >0 13.8% vs 9.2%, p = 0.20 and AIS spine >0 11.0% vs 9.3%, p = 0.63 respectively.ConclusionsModern BCVI therapy is administered early. BCVI with delayed therapy were more severely injured. However, a higher stroke rate was not seen with delayed therapy, even for BCVI with head or spine injuries. This data suggests with competing injuries or other clinical concerns there is not an increased stroke rate with necessary delays of medical treatment for BCVI.     

胶原蛋白酶诱发兔膝关节骨性关节炎软骨组织中HIF2α表达上调

目的 研究低氧诱导因子HIF2α在胶原蛋白酶诱发兔膝关节骨性关节炎（Osteoarthritis, OA )模型中的表达情况,为下一步以HIF2α为靶点进行OA靶向治疗研究提供实验基础。方法 取健康16周龄雄性日本大耳白兔24只,随机分为磷酸盐缓冲液（PBS)对照组和胶原蛋白酶诱发OA ( Collagenase-induced OA, CIOA)组。利用右侧膝关节腔内注射II型胶原蛋白酶 (剂量为0. 5 mg)方法建立膝关节OA模型。给药后24周处死动物,采用大体形态观察与HE、甲苯胺蓝染色观察关节软骨退变程度,应用微型CT( Micro-CT)观察软骨下骨改变情况,采用免疫组织化学（immunohistochemistry ,IHC)、蛋白质免疫印迹 (Western Wotting, WB)和实时荧光定量PCR( quantitative real time PCR, qRT-PCR)检测软骨中 HIF2α 表达情况。结果 大体形态观察结果显示,CIOA组关节面粗糙、糜烂,与溃疡形成,关节囊增厚,滑膜增生。组织病理学检测结果显示,CIOA组关节软骨缺损,软骨细胞数量减少,排序紊乱,有细胞簇聚现象。Micro-CT结果显示,CIOA组软骨下骨可见大量骨赘形成,关节间隙狭窄。IHC结果显示,CIOA组关节软骨中HIF2α蛋白阳性细胞数增加;WB结果显示,CIOA组关节软骨组织中HIF2α蛋白表达显著增加;而qRT-PCR结果显示,HIF2α mRNA表达显著降低。结论 在成功建立膝关节OA模型基础上,发现HIF2α在胶原蛋白酶诱发兔膝关节OA软骨中表达上调,其表达调控可能在转录后水平进行。我们的实验结果提示HIF2α特异性抑制剂可能被用于缓解OA发生。     

定量CT骨密度测量诊断中国老年男性人群骨质疏松

目的 评价定量CT(QCT)骨密度测量在诊断老年男性骨质疏松症中的应用价值。方法 收集我院同时接受腰椎DXA、髋关节DXA和腰椎QCT检查、年龄>60岁的男性受检者314例。比较DXA和QCT对骨质疏松症检出率的差异。结果 DXA(腰椎正位、髋关节)对老年男性骨质疏松的检出率(35/314,11.15%)低于腰椎QCT对老年男性骨质疏松的检出率(141/314,44.90%;χ²=88.70,P<0.05)。结论 腰椎QCT BMD测量对中国老年男性人群骨质疏松症的早期诊断具有重要作用。     

骨折愈合过程中骨痂力学强度与骨痂灰度相关性研究

目的：为建立一种客观无损伤的骨折愈合评估方法，方法：用计算机图像处理方法，对４８例成人新鲜骨干骨折，５０例成人陈旧骨干骨折，７０只家兔实验性胫骨骨折的Ｘ线片进行分析，结果：骨痂力学强度与骨痂Ｘ线灰度呈指数相关（Ｐ〈０．０５），骨痂Ｘ线灰度随骨折愈合的进程而增高，结论：骨力学强度特性与骨痂Ｘ线灰度密切相关，为中西医结合治疗骨折提供了一个客观的疗效评估方法。     

Risk factors for implant failure of intertrochanteric fractures with lateral femoral wall fracture after intramedullary nail fixation

IntroductionFew studies have specifically evaluated the comminution extent of lateral femoral wall (LFW) fracture and risk factors of implant failure in intertrochanteric fractures with LFW fracture. The aim of present study was to evaluate the influence of comminution extent of LFW fracture on implant failure and identify risk factors of implant failure in cases with LFW fracture after intramedullary fixation.MethodsThis retrospective study included 130 intertrochanteric fracture with LFW fracture treated with intramedullary fixation at a teaching hospital over a 13-year period from January 2006 to December 2018. Demographic information, cortical thickness index, the reduction quality, status of medial support, position of the screw/blade and status of lateral femoral wall were collected and compared. The logistic regression analyzes was performed to evaluate risk factors of implant failure in intertrochanteric fractures with LFW fracture after intramedullary nail fixation.Results10 patients (7.69%) suffered from mechanical failure after intramedullary fixation. Univariate analyzes showed that comminuted LFW fracture (OR, 7.625; 95%CI, 1.437~40.446; p = 0.017), poor reduction quality (OR, 49.375; 95%CI, 7.217~337.804; p < 0.001) and loss of medial support (OR, 17.818; 95%CI, 3.537~89.768; p < 0.001) were associated with implant failure. After adjustment for confounding variables, the multivariable logistic regression analyzes showed that poor reduction quality (OR, 11.318; 95%CI, 1.126~113.755; p = 0.039) and loss of medial support (OR, 7.734; 95%CI, 1.062~56.327; p = 0.043) were independent risk factors for implant failure. Whereas, comminuted LFW fracture was not associated with implant failure (p = 0.429).ConclusionsThe comminution extent of the LFW fracture might influence the stability of intertrochanteric fractures; and intramedullary fixation might be an effective treatment method. Furthermore, poor reduction quality and loss of medial support could increaze the risk of implant failure in intertrochanteric fractures with LFW fractures after intramedullary fixation. Therefore, we should pay great emphasis on fracture reduction quality in future.