骨质疏松性骨折骨痂软骨细胞CD44、FN表达的实验研究

目的：探讨骨质疏松性骨折愈合过程中胞内信号因子CD44及其配体FN在骨痂软骨细胞的表达情况。方法：建立28只SD大鼠骨质疏松性股骨骨折愈合模型作为实验组以及28只二期股骨骨折愈合模型作为对照组，分别于骨折后的d10、d20、d30、d40取材，对骨痂进行HE染色及CD44、FN免疫组化染色。结果：在骨痂组织中CD44和FN的表达及分布在时空上有一致性。在实验组中，随着骨折愈合进程的发展，软骨细胞CD44与FN的表达逐渐减少，而对照组中，CD44与FN共同表达于骨折愈合各阶段的各区软骨细胞中。结论：大鼠骨质疏松性骨折愈合过程中骨痂软骨细胞CD44、FN的表达明显弱于正常二期骨折愈合过程中的表达，提示：CD44、FN在软骨细胞中表达的明显减少可能是造成骨质疏松性骨折骨痂软骨组织向骨组织演变缓慢的原因之一。     

碱性成纤维细胞生长因子对兔关节软骨全层缺损的修复作用

目的：利用注射型活性材料碱性成纤维细胞生长因子（bFGF）修复兔关节软骨缺损，观察其治疗效果。方法：实验尝试在兔的膝关节软骨缺损区应用碱性成纤维细胞生长因子，分别于10周，14周，18周处死，观察大体和形态学特征，组织学评分。结果：A组于10、14周时，软骨缺损被白色半透明坚硬组织平滑修复，富有光泽，与正常软骨边界清楚，18周时修复组织与正常软骨边界模糊，质地坚硬，表面平滑光润。对照组于10、14、18周时均未见软骨修复。组织学评分A组明显优于对照组。结论：碱性成纤维细胞生长因子可以有效修复兔关节软骨的缺损，为组织工程化软骨的临床应用提供理论基础。     

藻酸包埋异体关节软骨细胞修复兔膝关节软骨缺损

目的 探讨异体关节软骨细胞作为软骨种子细胞修复关节软骨缺损的可行性。方法 无菌取成年新西兰大白兔四肢关节软骨，酶消化法分离细胞，条件培养基体外培养扩增，藻酸钙凝胶包埋培养1周，植入兔膝关节股骨髁间软骨缺损，对照组缺损旷置。术后3、6个月分别取材，观察缺损修复情况；切片特染和免疫组化观察修复组织病理，并Wakitnni评分评估修复质量。结果 7／8缺损为成熟透明软骨组织修复，1／8为纤维软骨修复；Wakitani平均评1．75分；空白对照组评7．65分。实验组3个月组标本未见淋巴细胞或白细胞浸润，6个月组标本未见明显退变；所有标本均未见藻酸残留。结论 用藻酸包埋异体关节软骨细胞修复兔膝关节软骨缺损的方法是可行的，异体关节软骨细胞在适当的处理后可成为关节软骨组织工程种子细胞。     

诱导脂肪干细胞成软骨分化的研究进展

由创伤或其他病因引起的关节软骨病变通常难以自愈,且目前临床上的治疗方法疗效欠佳。脂肪干细胞 (adipose derived stem cells,ADSCs)是一种来自脂肪组织、具有多向分化潜能的干细胞,基于ADSCs成软骨分化能力的 组织工程学疗法为关节软骨缺损的修复再生提供了新的思路。体外诱导ADSCs分化成软骨的方法主要是采用生长因 子和支架材料模拟体内微环境,进而促进ADSCs向软骨细胞分化,其相关应用已取得初步成功。     

Tolerancia oral en artritis experimental inducida por antígeno en conejos por administración de hidrolizado de cartílago articular

Rheumatoid arthritis is an autoimmune disease characterized by polyarticular inflammation, swelling and inflammation that affects more than 1% of the world population. The pathobiology of rheumatoid arthritis involves several cell populations as T lymphocytes, B, macrófagosy fibroblasts, and a complex proinflammatory cytokines interactions. Conventional and biologic therapies do not always work or produce only a partial improvement. Immunological tolerance is a mechanism by which the immune system prevents autoreactivity. The aim of this pilot study was to evaluate the efficacy of peptides from an from articular cartilage hydrolysate extracted of tarsus (HCA) for the treatment of rheumatoid arthritis in a model of rheumatoid arthritis (AAE) in rabbits. AAE animals showed inflammation and pain within de first month of the primary immunization that was reversed in the AAE + HCA group. The control group showed a normal unnaffected synovial tissue. The AAE group revealed an inflamatory process whith synovial hyperplasia, filtering in lymphocytes and vascular proliferation. The treated group decreased significantly inflammation, lymphocyte proliferation and angiogenesis. Arthritic rabbits increased the levels in flammatory markers as nitric oxide, interferon gamma (INF-ɣ) and tumor necrosis factor alpha (TNF-α) compared to control and significantly reduced levels of interleukin 4 (IL-4). The treatment showed a significant reduction of nitricoxide, IFN-gamma and TNF-alpha and an increase in IL-4. This work suggests that this therapy may be useful in the clinical aspect and the biochemical and immune parameters. Future studies with larger numbers of animals and other laboratory parameters may provide additional evidence in this regard.     

Inflammation and arthritis: perspectives of the glycobiologist

This review focuses on the role of glycosylation during the development of joint inflammation and degeneration. Although glycoproteins and glycan-binding proteins have essential functions in bone and cartilage, and in the inflammatory process, their exact roles are still uncertain due to the vast complexity of carbohydrate structures. Glycosylated epitopes have been shown to play a role in the induction of arthritis in animal models. Currently available drugs are aimed at the protection of cartilage and bone structures but new developments in this area should take into account the tight and specific interactions between bone and cartilage. It is anticipated that new agents will help to remodel damaged joints, based on knowledge of cartilage and bone turnover and on the exact role of glycosylated molecules and cell surface receptor glycoproteins in these processes. Highly sensitive imaging techniques and well-characterized In vivo models will accelerate this development.     

XXIX Italian Society for the Study of Connective Tissues (SISC) Meeting,October 29–30, 2009, Alghero,Italy

Soluble substances in the bovine nuchal ligament were removed by preliminary extractions with a buffer and dilute alkali solution. The insoluble residue was then extracted with 6 M guanidine HCl and with 6 M guanidine HCl containing a reducing agent (20 mM dithiothreitol) successively. Each of the two extracts contained a glycoprotein; that in the first extract was designated Glycoprotein A and that in the second Glycoprotein B. They were purified by ion-exchange chromatography and gel filtration till essentially homogeneous. Both proteins had similar molecular weights of 35,000 in SDS-polyacrylamide gel electrophoresis and by gel filtration, and their chemical compositions resembled each other closely. It is suggested that Glycoprotein B was present in the native state as a disulfide-bonded, aggregated form of Glycoprotein A. The compounds also showed similarity with the microfibrillar glycoprotein(s) previously reported in bovine nuchal ligament extracts.     

Biocompatibility of subcutaneously implanted marine macromolecules cross-linked bio-composite scaffold for cartilage tissue engineering applications

There is an intense interest in developing innovative biomaterials which support the invasion and proliferation of living cells for potential applications in tissue engineering and regenerative medicine. Present study demonstrated the in vivo biocompatibility and toxicity of a macromolecules cross-linked biocomposite scaffold composed of hydroxyapatite, alginate, chitosan and fucoidan abbreviated as HACF. The in vivo biocompatibility and toxicity of HACF scaffold were tested by comparing them with those of a biocompatible surgical metal implant (SMI) in a subcutaneous rat model. Following the implantation, animals were sacrificed and the scaffolds were resected at 1st, 4th, and 8th weeks; the surrounding tissue along with the implant was removed to evaluate its biocompatibility. The effects of implanted biomaterial scaffolds on vital organ systems such as liver, kidney, etc., have been studied by hematology and serum biochemistry. The activities of pro-inflammatory marker enzymes such as COX, 5-LOX, 15-LOX, and NOS were normal in rats implanted with HACF scaffold. Hematological parameters, antioxidant and lipid peroxidation status were also found to be normal in implanted rats same as that of control and SMI. The modulatory effect of implanted scaffold over inflammatory and stress signaling cascades were confirmed by the normalized mRNA expressions of NF-κB, TNF-α and IL-6. The histopathological analysis of liver, kidney and tissue support our results. Taken together, these results demonstrated that HACF biocomposite scaffold signifies its suitability for further research as a scaffold material for cartilage tissue engineering applications.