以自体诱导和无诱导的骨髓基质干细胞复合珊瑚修复犬下颌骨节段缺损的比较研究

目的分别采用诱导和无诱导的自体骨髓基质干细胞（Bone marrow stromal cells，BMSCs）复合珊瑚构建组织工程化骨，修复犬下颌骨节段性缺损，比较修复效果。方法体外扩增、成骨诱导或无诱导培养犬BMSCs，分别将第2代细胞复合珊瑚后修复犬自体右侧3cm的下颌骨节段缺损（诱导组n=6，无诱导组n=6）。术后32周，分别通过Micro-CT、大体形态观察和组织学方法检测骨缺损的修复效果。结果32周时，Micro-CT检测示诱导组骨容积率和密度均显著高于对照组（P〈0.05）；大体观察示诱导组骨愈合良好，无诱导组中的3条犬为骨不连；组织学检测诱导组有较多成熟骨形成，缺损部分均呈骨性愈合。无诱导组中的3只犬有新骨形成，但形态不完整，另3只犬的缺损部分呈纤维性愈合。结论成骨诱导的自体BMSCs复合珊瑚形成的组织工程化骨修复犬下颌骨节段缺损效果优于无诱导组。     

骨髓基质干细胞体外复合珊瑚材料的生长和成骨活性

目的 尝试以骨髓基质干细胞(Bone Marrow Stromal Cells,BMSCs)作为种子细胞,复合珊瑚体外培养,以发现适宜的细胞接种密度以及复合物体外共培养时间.方法 分离犬BMSCs,成骨诱导后复合珊瑚继续培养,以无诱导BMSCs复合物为对照.进行黏附率、生长曲线、扫描电镜、碱性磷酸酶(AKP)和骨钙蛋白(OCN)生物化学定量检测.结果 AKP和OCN检测均显示成骨诱导BMSCs-材料组显著高于无诱导BMSCs-材料组.复合物接种密度超过1.5×107/cm3时,黏附率显著下降;生长曲线示7天后BMSCs在材料上生长进入平台期,电镜示诱导BMSCs复合珊瑚7天后生长良好,且OCN从第7天开始表达.结论 诱导BMSCs-珊瑚复合物成骨活性高于无诱导细胞-材料复合物.复合物接种密度1.5×107/cm3,体外共培养7天较适宜.     

珊瑚用以骨缺损修复的研究进展

珊瑚大量存在于自然界中，因具有疏松多孔的三维空间结构，且具有良好的生物相容性，无免疫原性，无毒副作用，基于以上特性，现已被用以作为骨缺损填充材料的研究，并已取得大量成果，现将该领域的研究进一综述。     

Temporal analyses of coral snakebite severity published in the American Association of Poison Control Centers’ Annual Reports from 1983 through 2007

Introduction.?The only U.S. Food and Drug Administration-approved coral snake antivenom was officially discontinued in 2007, causing ever-diminishing supplies. This study describes the severity of U.S. coral snakebites during the last 25 years to determine trends in annual rates of these bites' medical outcomes.?Methods.?This study retrospectively analyzed all human coral snakebites voluntarily reported by the public and/or health care professionals to poison centers that were subsequently published in the Annual Reports of the American Association of Poison Control Centers (AAPCC) from 1983 through 2007. Annual rates of medical outcomes from coral snakebites were calculated by dividing the annual number of people bitten by coral snakes who developed fatal, major, moderate, minor, or no effect outcomes by the total annual number of people bitten by coral snakes. Negative binomial regression was used to examine trends in annual rates.?Results.?From 1983 through 2007, the incidence rate of coral snakebites producing no effects significantly decreased by 4.7% per year [incidence rate ratio (IRR) = 0.953; 95% confidence interval (CI) = 0.920–0.987]. From 1985 through 2007, the incidence rates of minor and major outcomes did not significantly change; however, moderate outcomes significantly increased by 3.4% per year (IRR = 1.034; 95% CI = 1.004–1.064). No fatalities were reported from 1983 through 2007.?Conclusion.?Annual rates of coral snakebites producing no effects significantly decreased and those producing moderate outcomes significantly increased in our analyses of data from the last 25 years of published AAPCC Annual Reports. This study has important limitations that must be considered when interpreting these conclusions.     

A comparative study of phenoloxidase activity in diseased and bleached colonies of the coral Acropora millepora

In scleractinian (hard) corals, immune responses involving phenoloxidase (PO) activity are known to play a role in coral wound healing, but there have been no studies investigating their roles in mitigating either disease or bleaching in an Indo-Pacific coral. PO activity induces the release of reactive oxygen species leading to a cytotoxic cellular environment, which enhances resistance against pathogens, but is also likely to compound oxidative stress induced during bleaching. Antioxidants such as melanin, whose synthesis is activated by PO activity, and peroxidase are potentially important for mitigating the effects of oxidative stress. Therefore, PO activity was investigated in healthy and diseased colonies of Acropora millepora. PO activity levels were compared among tissues bordering white syndrome lesions (WS) and at two locations (mid and outer) at increasing distances from lesions. Equivalent locations were sampled for PO activity on visibly healthy colonies. Additionally, PO and peroxidase activity were compared between severely bleached and healthy colonies of A. millepora. Overall, PO activity of diseased colonies was significantly lower than that of healthy colonies, but with relatively higher activity at the WS lesion border. Severely bleached colonies had significantly lower PO activity than healthy colonies, and peroxidase was also lower, but not significantly. Lower PO activity in unhealthy colonies supports earlier suggestions that lower immune activity leads to increased susceptibility to disease and bleaching. Additionally, low enzyme activity levels may indicate a depletion of colony resources. Increased PO activity at lesion borders in diseased colonies confirms the relative up-regulation of a key coral immune defense in response to WS in A. millepora.     

bBMP／胶原／珊瑚复合人工骨修复股骨头骨缺损的影像学研究

目的：研究用复合人工骨治疗肌骨头坏死的效果。材料与方法：建立双侧股骨头内骨缺损模型,并分为4组：（1）bBMP/ 胶原／珊瑚复合人工骨组（95侧）,（2）肌骨瓣组（5侧）,（3）单纯珊瑚组（4侧）,（4）对照组（14侧（为以上各组的对侧）。对造模后及植入后定时行普通X线,核素骨像,MRI及CT检查。结果：（1）核素骨显像示：6周及12周,1组股骨头核素摄取量静态相头／干比升高,但血液相及血池相不升高。（2）,MRI示：10周,I组原骨缺损区内T1WI及T2WI均为低信号区,提示多量新生骨形成,Ⅳ组T1WI及T2WI示中部为高信号区,周围为环形低信号带,提示囊腔中为脂肪性骨髓,周围为硬化带。（3）拍片及CT示,14－16周,I组骨缺损大多完全闭合,珊瑚已吸收,其余各组骨缺损部分残留,Ⅳ组骨缺损囊壁硬化带形成。结论：该复合人工骨有较强的传导成骨及诱导成骨作用,是修复股骨头骨缺损的良好移植材料,但它不能改善缺血坏死股骨头的血供。     

天然珊瑚和同种异体脱钙骨基质作为骨组织工程支架的组织相容性研究

目的：评价天然滨珊瑚(NC)和同种异体脱钙骨(DBM)的组织相容性，探讨其作为骨组织工程支架的可行性。方法：将NC和DBM直接植入动物体内，术后1、2、6周取材，通过大体观察和组织学检查观察生物材料在体内组织反应。结果：两种材料均未引起明显的炎症和排斥反应，对实验动物无不良影响。同时发现DBM组诱导出少量骨组织，NC组未见新生骨。结论：NC和DBM具有良好的组织相容性，DBM还具有鲁诱导性，两种材料可能都是比较理想的骨组织工程支架材料。     

Efficacy of Trypsin in Treating Coral Snake Envenomation in the Porcine Model

Antivenom is the definitive treatment for venomous snakebites. Alternative treatments warrant investigation because antivenom is sometimes unavailable, expensive, and can have deleterious side effects. This study assesses the efficacy of trypsin to treat coral snake envenomation in an in vivo porcine model. A randomized, blinded study was conducted. Subjects were 13 pigs injected subcutaneously with 1 mL of eastern coral snake venom (10 mg/mL) in the right distal hind limb. After 1 min, subjects were randomized to have the envenomation site injected with either 1 mL of saline or 1 mL of trypsin (100 mg/mL) by a blinded investigator. Clinical endpoint was survival for 72 h or respiratory depression defined as respiratory rate <15 breaths per minute, falling pulse oximetry, or agonal respirations. Fisher’s exact t test was used for between group comparisons. Average time to toxicity for the saline control was 263 min (191–305 min). The development of respiratory depression occurred more frequently in control pigs than treated pigs (p = 0.009). Four of the six pigs that received trypsin survived to the end of the 3-day study. No control pigs survived. Two of the trypsin treatment pigs died with times to toxicity of 718 and 971 min. Survival to 12 and 24 h was significantly greater in the trypsin treatment group (p = 0.002, p = 0.009, respectively). Local injection of trypsin, a proteolytic enzyme, at the site of envenomation decreased the toxicity of eastern coral snake venom and increased survival significantly. Further investigation is required before these results can be extended to human snakebites.     

Construction of tissue-engineered bone with differentiated osteoblasts from adipose-derived stem cell and coral scaffolds at an ectopic site

Cell sheets from bone marrow mesenchymal stem cells (BMSC) have been widely used in the field of bone tissue engineering, although their source remains a challenging issue. In this study, adipose-derived stem cells (ADSC) were induced to differentiate into osteoblasts, and the incorporation of coral scaffolds with ADSC sheets for bone formation at an ectopic site was also investigated. First, ADSC isolated from inguinal adipose tissue of New Zealand rabbits were cultured for two weeks without passaging under osteogenic induction, and the microstructures of cell sheets were analysed by histological and scanning electron microscope (EM) observation. In addition, the activity of alkaline phosphatase (ALP) and alizarin red staining was also measured to detect their osteogenic ability. Subsequently, ADSC were proved to be able to proliferate well when seeded on the coral scaffolds. Next, coral scaffolds were wrapped in cell sheets to prepare sheet-coral complexes, which were implanted into subcutaneous pockets in nude mice. At eight weeks after implantation, gross examination, microcomputed tomography (MicroCT), and histological analysis were investigated to assess new bone formation. MicroCT scanning and histological analysis showed that there was more highly dense tissue formed in the complex group than control group (p=0.0004). These results indicated that osteoblastic ADSC sheets could be used to construct engineered bone and the incorporation of coral scaffolds with ADSC sheets significantly improved bone formation, providing a newly approach for bone tissue engineering.