Characterization of zebrafish mutants with defects in bone calcification during development

Using the fluorescent dyes calcein and alcian blue, we stained the F3 generation of chemically (ENU) mutagenized zebrafish embryos and larvae, and screened for mutants with defects in bone development. We identified a mutant line, bone calcification slow (bcs), which showed delayed axial vertebra calcification during development. Before 4–5 days post-fertilization (dpf), the bcs embryos did not display obvious abnormalities in bone development (i.e., normal number, size and shape of cartilage and vertebrae). At 5–6 dpf, when vertebrae calcification starts, bcs embryos began to show defects. At 7 dpf, for example, in most of the bcs embryos examined, calcein staining revealed no signals of vertebrae mineralization, whereas during the same developmental stages, 2–14 mineralized vertebrae were observed in wild-type animals. Decreases in the number of calcified vertebrae were also observed in bcs mutants when examined at 9 and 11 dpf, respectively. Interestingly, by 13 dpf the defects in bcs mutants were no longer evident. There were no significant differences in the number of calcified vertebrae between wild-type and mutant animals. We examined the expression of bone development marker genes (e.g., Sox9b, Bmp2b, and Cyp26b1, which play important roles in bone formation and calcification). In mutant fish, we observed slight increases in Sox9b expression, no alterations in Bmp2b expression, but significant increases in Cyp26b1 expression. Together, the data suggest that bcs delays axial skeletal calcification, but does not affect bone formation and maturation.     

Ostéomyélite de l’apophyse odontoïde : intérêt de la TEP/TDM au 18F-FDG dans le bilan d’extension infectieux à distance

Odontoid process is an atypical and very rare localization of osteomyelitis. We reported the case of a 72-year-old hemodialysed man with methicillin-sensitive Staphylococcus aureus osteomyelitis of the odontoid process. Osteomyelitis was diagnosed at MRI and ¹⁸F-FDG PET/CT. While clinical examination and conventional radiographs were non contributive, ¹⁸F-FDG PET/CT also allowed the diagnosis of right foot osteomylitis and multiple vertebral septic localizations. ¹⁸F-FDG PET/CT done at month 3 demonstrated a regression of the odontoid and foot hypermetabolic activity. This case illustrates the atypical presentation of this septic localization and the usefulness of ¹⁸F-FDG PET/CT to perform whole body screening and detect septic metastasis.     

Micro-CT检测中等强度跑台运动对去卵巢大鼠腰椎微结构的影响

目的用micro-CT方法,评估中等强度跑台运动对去卵巢大鼠腰椎微结构的影响。方法将30只3月龄雌性SD大鼠按体重分层后随机分为假手术、去卵巢静止和去卵巢运动三个组。运动组每周进行4次45min、速度18 m/min、坡度5°的跑台训练。正式运动处理14周时,取第2腰椎检测骨密度,取第4腰椎行micro-CT分析及三维结构重建;取第3腰椎椎体进行椎体压缩实验。结果去卵巢运动组第2腰椎骨密度、第3腰椎最大载荷、最大应力和弹性模量以及第4腰椎骨小梁体积和骨小梁数目显著高于去卵巢静止组,骨小梁分离度显著低于去卵巢静止组,而骨小梁厚度无显著变化。结论中等强度跑台运动能改善去卵巢大鼠腰椎的微结构。     

锁定加压钢板和动力加压钢板治疗肱骨中下段骨折的临床比较研究

目的:对比锁定加压钢板与动力加压钢板治疗肱骨中下段骨折患者的临床疗效。方法:抽取我院2010年8月~2013年12月收治的肱骨中下段骨折患者76例,按照随机数字表法分为锁定组(锁定加压钢板治疗)与动力组(动力加压钢板治疗),每组38例,随访1年。对比两组患者临床指标,治疗效果及并发症发生率。结果:锁定组患者手术时间、骨折愈合时间及住院时间均小于动力组,差异均有统计学意义(P0.05);锁定组患者优良率为89.47%,显著高于动力组的71.05%,差异有统计学意义(P0.05);锁定组的并发症发生率为10.53%,显著低于动力组的31.58%,差异有统计学意义(P0.05)。结论:锁定加压钢板应用于治疗肱骨中下段骨折患者疗效优于动力加压钢板治疗,它具有创伤小、恢复快的优点,且并发症发生率较低,值得推广。     

微创经皮钢板联合锁定加压钢板固定术治疗胫骨干骺端骨折的临床疗效

目的:探讨微创经皮钢板固定技术(MIPPO)与锁定加压钢板(LCP)治疗胫骨干骺端骨折的临床疗效。方法:选择2013年6月-2015年6月在我院接受手术治疗的胫骨干骺端骨折患者103例作为研究对象,根据手术方法不同将所选患者分为三组。其中,联合手术组(35例)患者采用MIPPO联合LCP内固定术治疗,外固定组(33例)患者采用超关节外固定支架术治疗,内固定术组(35例)患者采用切开复位钢板内固定术治疗。观察并比较三种手术方法的临床效果及对患者骨关节功能的影响。结果:与外固定术组及内固定术组比较,联合手术组患者的手术时间短,术中出血量少,骨折愈合时间早,差异具有统计学意义(P0.05);联合手术组患者的手术优良率高于外固定组和内固定组,差异有统计学意义(P0.05);内固定组手术优良率高于外固定组,差异具有统计学意义(P0.05);联合手术组患者术后并发症的发生率低于外固定组及内固定组,差异具有统计学意义(P0.05);外固定组与内固定组术后并发症的发生率比较,差异无统计学意义(P0.05)。结论:MIPPO联合LCP内固定治疗胫骨干骺端骨折具有手术切口小、术中出血量少、术后并发症发生率低、骨折愈合快、关节功能恢复较好等优点,是治疗胫骨干骺端骨折的理想方法,值得临床推广应用。     

椎弓根钉棒系统加植骨融合治疗胸腰椎爆裂性骨折并脊髓损伤的 临床研究

目的:探讨椎弓根钉棒系统加植骨融合治疗胸腰椎爆裂性骨折并脊髓损伤的疗效。方法:回顾性分析2010年3月至2014年12月,采用椎弓根钉棒系统加植骨融合治疗93例胸腰椎爆裂性骨折并脊髓损伤患者的资料,男56例,女37例。致伤原因:交通事故伤27例,高处坠落伤47例,重物压伤19例。骨折节段:L1骨折22例,L2骨折16例,L3骨折6例,T11骨折15例,T12骨折34例。结果:本研究共93例患者,所有患者经过一般12个月的随访,其中平均随访13.8月(10-16月)。与术前相比,患者术后6个月伤椎前缘高度比值明显增加,Cobb角值和椎管占位率明显降低(t=6.167,7.241,7.143,P0.05)。术后12个月伤椎前缘高度比值明显增加,Cobb角值和椎管占位率明显降低(t=9.345,11.541,11.263,P0.05)。且患者术后12个月与术后6个月在伤椎前缘高度比值、Cobb角、椎管占位率上比较,差异具有统计学意义(t=9.632,8.154,7.415,P0.05),根据Frankel神经分级,术后大部分患者神经功能有所恢复。其中,Frankel分级为A的患者有35例恢复,术后有效恢复率为87.5%;B级患者有25例恢复,术后有效恢复率89.3%。C级和D级患者术后有效恢复率均为100%,B,C,D级患者与A级患者有效恢复率相比,差异没有统计学意义(x~2=0.051,2.196,1.253,P0.05),随访12个月期间,2例患者术后5个月出现内固定物松动,1例术后12个月发生螺钉断裂,其余患者无伤口感染、肺部感染、深静脉血栓等并发症发生。结论:椎弓根钉棒系统加植骨融合能有效治疗胸腰椎爆裂性骨折并脊髓神经损伤,术后患者神经功能恢复较好,并发症较少,值得临床推广使用。     

Mathematical modeling of cell growth in a 3D scaffold and validation of static and dynamic cultures

Tissue engineering, an immensely important field in contemporary clinical practices, aims at the repair or replacement of damaged tissues. The mathematical model proposed herein shows the distribution and growth of cells in their characteristic time in a 3D scaffold model. This study contributes to the progress of simulation techniques in static and dynamic cultures of bone tissue. Brinkman, nutrient transport, and cell growth equations are brought together to quantify the growth behavior of cells. However, when a static culture is being studied, the Brinkman equation is eliminated. The model was validated by experimental cell culture using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay and scanning electron microscopy. Then, static and dynamic cultures were compared to assess the cell density and cell distribution in the scaffold. Cell counting after 21 days of cell culture showed that the number of cells increased 42‐fold in static and 53.5‐fold in dynamic cultures, which was in good agreement with our model estimations (37‐fold increase in the number of cells in static and 49‐fold increase in dynamic cultures). In conclusion, our mathematical model could predict cell distribution and growth in the scaffold.     

Proteomic analysis of bone proteins adsorbed onto the surface of titanium dioxide

Osseointegration is the structural and functional connection between bone tissues and implants such as titanium dioxide (TiO₂). The bone-TiO₂ interface is thought to contain proteoglycans. However, exhaustive analysis of the proteins in this layer has not been performed. In this study, we evaluated the bone protein adhered on the surface of TiO₂ comprehensively. Pig bone protein was extracted by sequential elutions with guanidine, 0.1 M EDTA, and again with guanidine. The proteins obtained from these extractions were allowed to adhere to an HPLC column packed with TiO₂ and were eluted with 0.2 M NaOH. The eluted proteins were identified by LC/MS/MS and included not only proteoglycans but also other proteins such as extracellular matrix proteins, enzymes, and growth factors. Calcium depositions were observed on TiO₂ particles incubated with bone proteins, guanidine-extracted proteins adhered to TiO₂ displayed significantly high amounts of calcium depositions.     

Elastin‐like‐polypeptide based fusion proteins for osteogenic factor delivery in bone healing

Modern treatments of bone injuries and diseases are becoming increasingly dependent on the usage of growth factors to stimulate bone growth. Bone morphogenetic protein‐2 (BMP‐2), a potent osteogenic inductive protein, exhibits promising results in treatment models, but recently has had its practical efficacy questioned due to the lack of local retention, ectopic bone formation, and potentially lethal inflammation. Where a new delivery technique of the BMP‐2 is necessary, here we demonstrate the viability of an elastin‐like peptide (ELP) fusion protein containing BMP‐2 for delivery of the BMP‐2. This fusion protein retains the performance characteristics of both the BMP‐2 and ELP. The fusion protein was found to induce osteogenic differentiation of mesenchymal stem cells as evidenced by the production of alkaline phosphatase and extracellular calcium deposits in response to treatment by the fusion protein. Retention of the ELPs inverse phase transition property has allowed for expression of the fusion protein within a bacterial host (such as Escherichia coli) and easy and rapid purification using inverse transition cycling. The fusion protein formed self‐aggregating nanoparticles at human‐body temperature. The data collected suggests the viability of these fusion protein nanoparticles as a dosage‐efficient and location‐precise noncytotoxic delivery vehicle for BMP‐2 in bone treatment. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1029–1037, 2016