骨髓间质干细胞体外预构组织工程化肌腱的实验研究

目的探讨骨髓间质干细胞与胶原-聚羟基乙酸的细胞相容性,为构建组织工程化肌腱寻求理想方法.方法以贴壁法分离、培养骨髓间质干细胞,并检测CD44.在实验组中将骨髓间质干细胞置入含胶原-聚羟基乙酸的DMEM培基中培养:在对照组中将骨髓间质干细胞置入DMEM培基中培养.通过MTT方法比较两组的细胞活性和生长情况,并对实验组进行超微观察.以骨髓间质干细胞为种子细胞,以胶原-聚羟基乙酸为支架在体外预构组织工程化肌腱.结果以贴壁法原代培养骨髓间质干细胞,11天细胞即汇合成片,检测CD44示阳性.骨髓间质干细胞接种于胶原-聚羟基乙酸中混合培养后14天生长良好,始终保持89%以上的细胞活力,与对照组比较无显著差别;实验组细胞数未发生明显改变,而对照组从第4天开始即发生增殖.透射电镜示实验组细胞培养14天后仍保持旺盛的分泌功能.体外预构的组织工程化肌腱具有良好的形态,细胞伸展成梭形,沿聚羟基乙酸缝线大致平行排列.结论骨髓间质干细胞与胶原-聚羟基乙酸的细胞相容性好.以骨髓间质干细胞为种子细胞,以胶原-聚羟基乙酸为支架可在体外初步预构组织工程化肌腱.     

Microarray analysis of healing rat Achilles tendon: evidence for glutamate signaling mechanisms and embryonic gene expression in healing tendon tissue.

Tendon healing is a complex process consisting of a large number of intricate pathways roughly divided into the phases of inflammation, proliferation, and remodeling. Although these processes have been extensively studied at a variety of levels in recent years, there is still much that remains unknown. This study used microarray analyses to investigate the process at a genetic level in healing rat Achilles tendon at 1, 7, and 21 days postinjury, roughly representing the inflammation, proliferation, and remodeling phases. An interesting temporal expression profile was demonstrated, identifying both known and novel genes and pathways involved in the progression of tendon healing. Both inflammatory response and pro-proliferative genes were shown to be significantly upregulated from 24 h postinjury through to 21 days. Day 7 showed the largest increase in genetic activity, particularly with the expression of collagens and other extracellular matrix genes. Interestingly, there was also evidence of central nervous system-like glutamate-based signaling machinery present in tendon cells, as has recently been shown in bone. This type of signaling mechanism has not previously been shown to exist in tendon. Another novel finding from these analyses is that there appears to be several genes upregulated during healing which have exclusively or primarily been characterized as key modulators of proliferation and patterning during embryonic development. This may suggest that similar pathways are employed in wound healing as in the tightly regulated progression of growth and development in the embryo. These results could be of use in designing novel gene-based therapies to increase the efficacy and efficiency of tendon healing.     

Flexor digitorum profundus tendongrafting (extrasynovial donor tendons)

Although the prevalence of flexor tendon grafting has decreased since the early part of this century, the technique isstill an important part of a hand surgeons armamentarium. Primary and staged flexor tendon grafting are appropriate techniques used to restore digital function after failed or neglected repairs. Appropriate patient selection, meticulous reconstructive techniques, and respect for basic biological principles of healing and repair are essential elements for successful tendon grafting.     

跟腱反射时间测定评价甲状腺功能的探讨

对103名甲状腺功能正常者,89例甲状腺功能亢进症(甲亢)患者,10例甲状腺机能减退症(甲低)患者,分别测定了跟腱反射时间并与放免测定血清T_3、T_4相比较。结果:甲状腺功能正常者符合率为100％,甲亢符合率为83％,甲低符合率为90％。认为,跟腱反射时间测定对甲状腺功能的判断比较淮确,并且方法简便易行。     

Site-related variations in glycosaminoglycan content and swelling properties of bovine flexor tendon

The presence of morphologically distinct tissues within the adult bovine deep flexor tendon presented a model which we examined for correlations between proteoglycan content and tissue swelling properties. The proximal portion which experiences only tensile forces contained low levels of glycosaminoglycan (0.2% glycosaminoglycan hexosamine as percentage of dry weight) that were evenly distributed throughout its length and thickness. Collagen accounted for 80% of tissue mass, and collagen fibers formed parallel arrays running longitudinal to the direction of tensile force. In equilibrium bulk swelling tests, the properties of proximal tissue were uniform throughout the tissue and typical of collagenous tissues in which the response to equilibration in low ionic strength buffers or acid pH is dominated by the collagen network. The anterior aspect of the distal deep flexor tendon articulates with the stiff paratendinous sheath and sesamoid bones and is subjected to compressive and frictional forces in addition to longitudinal tensile forces. Along this anterior surface and extending partially into the tendon is tissue that resembles fibrocartilage with collagen fibers organized as a random network. Greatest glycosaminoglycan hexosamine contents (2-3% of dry weight) were found in the distal surface layer, and large proteoglycans were concentrated at the site receiving direct compressive and frictional loads. Equilibrium bulk swelling tests on distal tissue showed that the articulating surface layer possessed unique material properties. Distal surface layers swelled when counter ions were washed from the tissue, whereas lowered pH had little effect on distal tissue volume. Swelling properties of distal tissue correlated directly with proteoglycan content and were similar to swelling properties of articular cartilage. These results suggest that the articulating layer of distal flexor tendon is adapted for a unique set of mechanical requirements and that an elevated proteoglycan content at the site of compressive and frictional forces contributes to meeting these functional needs.     

不同保存方法对肌腱生物力学特征的影响

目的　分析 5种常用的肌腱保存方法对肌腱生物力学的影响。从生物力学的角度寻找最佳的保存方法 ,用于指导临床肌腱移植。方法　采用 5 0只健康白色Leghorn鸡 ,随机分成 5组 ,建立 2 ,3 ,4爪浅屈肌腱做供体模型。分别采用常用的保存组织方法 :低温冷藏 ,70 %酒精 ,10 %福尔马林 ,85 %甘油。结果　低温冷藏组在最大抗拉伸力Pmax及最大延伸率δmax与新鲜肌腱组比较 ,无明显差异。酒精组、85 %甘油组最大抗拉伸力较高 ,而福尔马林组最低。结论　低温冷藏的方法保存肌腱 ,从生物力学角度考虑是最佳的保存方法     

小腿后部巨大腓动脉逆行皮瓣修复足部皮肤软组织缺损

目的 探讨小腿后部巨大腓动脉逆行皮瓣在修复足部、足远侧半大面积皮肤缺损的应用效果.方法 应用小腿后部巨大腓动脉逆行皮瓣修复11例含一个或多个跖趾关节外露的、足部大面积皮肤缺损.皮瓣设计:上界超过腓骨头平面.外侧界达腓骨前缘前2 cm,内侧界达腓肠肌内侧缘,下界达内外踝连线,以外踝上1 cm为旋转点.手术要点:解剖皮瓣时应将腓动脉在外踝上11～13 cm和5～7 cm两个肌皮支和(或)皮支带入,并包含腓肠神经、小隐静脉在内的3 cm宽筋膜蒂.结果 本组11例中10例皮瓣全部成活,1例皮瓣边缘1 cm宽区域坏死,经换药处理后愈合.结论 应用小腿后部巨大腓动脉逆行皮瓣修复足部大面积皮肤缺损,尤其是含足远侧半的皮肤缺损,皮瓣成活率高,对肢体供血影响小,血管蒂恒定,解剖容易,易于推广.