ULTRASTRUCTURAL INVESTIGATION OF EXPERIMENTAL FRACTURE HEALING ROLE OF OSTEOGENESIS PLAYED BY FIBROBLASTS

Transmission electron microscopic investigation of standardized fractures of radii in 50 rabbits re vealed that fibroblasts took part in the formation of bony callus. The osteogenetic role played by the fibroblasts can be categorized into the following 5 aspects: a. Fibroblasts synthesize and secrete Type collagen fibrils and induce deposition of calcium salt crystals in the collagen fibrils. b. Fibroblasts produce matrix vesicles in their surroundings. These matrix vesicles become calcified and turn into floccu- lent calcospherules which coalesce and fuse into bone tissues. c. Fibroblasts harbor calcium granules in their mitochondria, thus providing calcium for calci- fication of the intercellular matrix and bone forma tion between the cells. d. Fibroblasts can transform directly into osteocytes; there is bone formation around the fibroblasts, the bone tissues surround the fibroblast in the form of bony lacuna, then the fibro- blast in the lacuna transforms into osteocyte. e. Fibroblasts can undergo degenerative changes leading to decease and replacement by bone tissues.     

Ultrastructural investigation of calcification and ossification in experimental fracture healing with special reference to osteogenic role of fibroblasts.

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制动后骨质疏松和骨血流变化

骨质疏松可分为两大类型:全身性和局限性;老年或绝经期后骨质疏松、甲状腺或甲状旁腺机能亢进、皮质醇过多、肢端肥大等继发的骨质疏松均属于前者;骨折或骨关节疾病行石膏制动、中枢神经系统、脊髓或周围神经系统损伤导致肌肉瘫痪引起的骨质疏松则属于后者。运动增加骨承受的应力,骨对运动的反应是皮质厚度增加和骨髓腔缩小,骨体积因而增大;制动则在局部范围内使肌肉加于骨的机械性刺激丧失或减少,骨吸收多于骨形成,骨质更新(Turnover)和钙代谢都处于负平衡,表现为     

微血管周细胞的功能及潜在成骨能力

周细胞由星状间充质细胞所形成，并包在微血管内皮细胞外面。周细胞除有收缩作用，起干细胞作用参与伤口愈合、吞噬及防止渗漏等功能外，尚有成骨能力。应用Monastral蓝作标记，可以观察到周细胞演变为成骨细胞的过程。将周细胞作体外培养，可以具有成骨细胞表型的表达。     

COEXISTENCE OF OSTEOARTHRITIS AND OSTEOPOROSIS INFEMORAL HEAD: A SCANNING ELECTRONMICROSCOPIC STUDY

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胶元和基质在骨折修复过程中的演变(实验研究)

骨折愈合涉及三个主要方面,即细胞活动、有机母质(包括胶元和基质)形成和无机盐沉积。胶元和基质是骨痂的主要组成部分,它们的形成反映了细胞活动,它们和钙化亦有密切的关系。应用生化方法能测定骨痂中的胶元和基质内各种成分的性质和含量;如应用组织化学方法,则不但能在骨折区将这些成分定位,而且还能看到它们在骨折愈合各阶     

EXPERIMENTAL STUDY ON INDUCTION OF OSTEOGENETIC POTENTIAL OF DERMAL FIBROBLASTS

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ULTRASTRUCTURAL INVESTIGATION OF EXPERIMENTAL NON-UNION OF FRACTURES A TRANSMISSION ELECTRON MICROSCOFSIC TUDY

In the course of development of non-union from excision of a Gmm osteoperiosteal segment of rabbit radius, there emerged abnormalitism on the part of the cellular activities. The osteoprogenitor cells per sisted for a much longer period. The macrophages increased in number, persisted longer and were immature. The fibroblasts became elongated like fibrocytes, were haphazardly arrayed and showed emptying of the cytoplasm. The osteoblasts assumed olive or spindle configuration and showed vacuoliza- tion. Several vacuolized osteoblasts could be be- sieged in a single lacuna and eventually disintegrated. Chondrocytes revealed unusually high activities. The osteoclasts appeared early, increased in number and many were immature. In the marrow cavities there werc special fat structures to block the healing between the two fragments.