ULTRASTRUCTURAL INVESTIGATION ON EXPERIMENTAL FRACTURE HEALING VI. ELECTRON MICROSCOPIC OBSERVATION ON MATRIX VESICLES

In the course of healing of standardized radius fracture in rabbits, there is emergence of extracellular matrix vesicles with subsequent calcification priOr to the deposition of calcium salts in the collagen fibrils. The calcified matrix vesicles turn into flocculent cal cospherules which coalesce to form bone substance. The phenomenon of calcification of matrix vesicles takes place not only around the osteoblasts and chon drocytes but also around the fibroblasts. The same se- quential events about changes in matrix vesicle can be detected whether the fibroblasts are in an active se- creting state, and transform into osteocytes, or under- go degeneration, decease, and replacement by bone substance. Because deposition of calcium salt crystals takes place in the collagen fibrils abutting the fibro- blasts and the fibroblasts transform into osteocytes, the findings in our study show the importance of fibroblasts in osteogenesis in the course of fracture healing.     

LIGHT MICROSCOPIC AND ELECTRON MICROSCOPIC OBSERVATION ON EXPERIMENTAL FRACTURE HEALING

After a bone is broken, various cells appear in the fracture region. Each type has its specific activity, however, striving from the angles of their dissimilar functions they all engage in restoring the original anatomy and function to the injured bone. They are polymorphonuclear neutrophils, osteogenic cells, macrophages, fibro- blasts, chondroblasts, osteoblasts, osteocytes and osteoclasts The activity, transformation and fate of the cellular components, fiber formation and calcium salt deposition are studied by light microscope and electron microscope.     

ULTRASTRUCTURAL INVESTIGATION. OF EXPERIMENTAL FRACTURE HEALING IV. ELECTRON MICROSCOPIC OBSERVATION ON TRANSFORMATION AND FATE OF FIBROBLASTS AND CHONDROCYTES

The results of electron microscopic observa- tion on transformation of fibroblasts and chond- rocytes in experimental fracture healing in 75 healthy male white rabbits are reported. It is found that in the course of fracture healing, fibroblasts either undergo degenerative changes leading to decease and replacement by bony tissue or transform without degeneration into osteocytes directly. Consequently they not only produce collagen fibrils and form fibrous callus, but also play an important role in elaborating bony callus and creating osteocytes. In endochondral ossification, chondrocytes pass through various degenerative changes to end in decease and replacement by bony tissue.     

ULTRASTRUCTURAL INVESTIGATION OF EXPERIMENTAL FRACTIJRE HEALING L* ELECTRON MICROSCOPIC OBSERVATION OF CELLULAR ACTIVITY

Cellular activity in rabbit radius fractures is studied and observed by elcctron micro- scope. After fract,urc, polymorphonuclear neu- trophils, macrophages, fibrobIasts, chondroblasts and osteoblasts and osteoeytes appear at the fracture site in suc.cession. They represenL Lhe folloiving stages of fraet,ure healing: inflamma- tory stage, debridement stage, fibrous caUus stage, primary bony callus stage and secondary bony callus stage. Fibroblasts particjpate in and possess the action of osteagcnesis.     

ULTRASTRIUCTURAL INVESTIGATION OF EXPERIMENTAL FRACTURE HEALING* III. ELECTRON MICROSCOPIC OBSERVATION ON DEPOSlTION OF CALCIUM SALT CRYSTALS

Osteoblasts and cfmndroblasts t,urn fibrous callus into bony callus through intramembra- nous and endochondrial ossification, completjng fracture repair. In fracture repair, with its special demands, the fibroblasts form bone, so czdcium salt crystal deposition takcs place in the collagen fibrils surrounding them. Depo- sitian of calcium salL crystals takes place not only in the typical collagen fibrils with 6-10 A periodici饥 brit also in the atypical collagen fibrils which are produced by chondroblasts and are irregular in size and array and pre- sent n0 6如 A periotlicity. Calcium salt crystals are not deposited throughout the whole length of the collagen fibrils at long one and tlie same time, instead they appear in scgmcnts before ihey coalesce inta single oncs in the iibril. There is an earlier deposition of calcimn salt crystals in the coar- ser and more mature and remote collagen fibnls than in the tibrils which are fi玎er, youn= ger and nearer to the cells. Calcium salts ex- ist in the form of granules in the membranes of mitochondria, rough suiiaced endoplasmic reticulum and in othcr inl.racellular mem'ora- nous strucfurcs. These granules provide es- sential raw materials lor calcium salt deposition in extracellular collagen fibrils.     

SURFACE ULTRASTRUCTURAL INVESTIGATION OF EXPERIMENTAL FRACTURE HEALING WITH SCANNING ELECTRON MICROSCOPE

The healing process of a standardized radial fracture was studied under scanning electron microscope (SEM). The active cellular activities of all main kinds of "osteogenesis cells", the collagen fibrils they produce and the three dimensional configurations of various calli are {lescribed. In the process of calcification, calcium salt moves from intracellular to the intercellular milieu throughout the whole course of fracture healing. In the early stage, calcium s.alt crystals deposited within the collagen fibrils in an un- homogeneous manner. As union is attained, the callus turns into finer homogeneous and becomes denser and more compact. It is concluded that the SEM is of value in the study of fracture healing mechanism.     

ULTRASTRUCTURE INVESTIGATION OF EXPERIMENTAL FRACTURE HEALING II.* ELECTRON MICROSCOPIC OBSP RTATION ON FIBRILLOGENESIS

Tnree different kinds of fibers are generated in the course of fracture healing: tibrin fibers, typical collagen fibrils produced by fibroblasts and ostcoblasts aud equally important atypical collagen fibrils produced by chondroblasts. In tho special situation of fracture repiiir mature collagen fibrils winh periodicity can be produced c7irectly in fibroblast CYtoplasZn.     

ELECTRON RADIOAUTOGRAPHIC STUDY OF EXPERIMENTAL FRACTURE HEALING

The mitotic activities of various cellular components of callus tissues in different periods after tibial fracture of rat were studied with 3H-thymidine labeling and electron radioautographic method. Silver grains were accumulated over the nuclear areas of mesenchymal cells, monocytes, macrophages, endothelial cells of capillaries, fibroblasts, chondroblasts and chondrocytes, as a result of incorporation of the labelling material during their mitosis. Although osteoblasts and osteocytes could not undergo mitosis, they also revealed silver grains over nuclear areas because of their derivation from the mesenchymal cells or osteogenic cells.     

实验性急性胰腺炎大鼠胰岛微血管的电镜观察

目的 :了解实验性急性胰腺炎大鼠早期胰岛微血管的超微结构变化 ,并探讨其与急性胰腺炎的关系。方法 :采用皮下注射超大剂量雨蛙素诱发大鼠急性水肿性胰腺炎 ,用扫描电镜和透射电镜观察急性胰腺炎早期胰岛微血管的形态和变化。结果 :①在透射电镜下 ,胰岛毛细血管内皮细胞肿胀 ,管腔狭窄、不规则 ,内皮细胞“窗孔”数量增加。②在扫描电镜下 ,胰岛毛细血管外形不规则 ,与外分泌部毛细血管之间的吻合明显减少 ;毛细血管表面可见铸型剂形成的泡状物。结论 :急性胰腺炎早期即有胰岛微血管损伤的表现 ,推测其与胰腺炎的进展密切相关。     

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.     

实验性糖尿病大鼠血小板扫描电镜观察

我们应用扫描电镜观察了链菌脲霉素(streptozotocin)引起的糖尿病大鼠血小板的形态改变。并检测了血小板和血清五—羟色胺(5—Hydroxytryptamine,5—HT)、五—羟吲哚乙酸(5—Hydroxy—indole-acetic acid,5—HIAA)含量。实验结果从形态学角度证明了糖尿病血小板聚集和释放活性增强。糖尿病大鼠血小板数明显减少。血清5—HT含量明显减少、5—HIAA含量增加,其原因可能与5—HT移除代谢增多、血小板摄取5—HT增多和5—HT生成减少有关的。     

实验性骨折愈合中骨吸收活动的超微结构观察

将50只家兔造成实验性桡骨骨折,分批取骨痂标本,用光镜和电子显微镜观察表明,在骨折愈合过程中,破骨细胞是骨吸收的主要执行者,巨噬细胞能吞噬死骨,但不能吸收骨质。     

肾小球疾病患者肾小球毛细血管基底膜缺损的电镜观察

本文报告在44例不同种类肾小球疾病肾穿刺标本的电镜观察,其中8例发现肾小球毛细血管基底膜缺损。按照Stejskal的分类法,可将缺损的超微结构改变分为4种类型。I型;足细胞和内皮细胞坏死,基底膜分层、破坏。Ⅱ型;基底膜分层,溶解,但无细胞坏死。Ⅲ型:缺损旁基底膜内有多量团块状电子致密沉着物。Ⅵ型:肾小球完全或不完全硬化,在一个毛细血管横断切面上可见到一个以上的缺损。一般认为,基底膜缺损是肾小球蛋白尿和血尿的形态学基础     

对胎儿肝脏表面间皮细胞的扫描电镜观察

本文用扫描电镜对10例不同胎龄人(12～38周)胎儿肝表面间皮进行了观察。研究结果发现各例间皮细胞表面都有微绒毛,但其长度、粗细和分布的疏密程度有所不同,经测算不同胎龄之微绒毛长度:12周时为1.00μm,以后逐渐增长至32周时为1.80μm,而38周者又减低为1.20μm,直径变化在0.10～0.19μm间。每平方微米的微绒毛数随胎龄增加而增多。本文对不同胎龄间皮之间的差异进行了描述,并联系其机能意义进行了讨论。     

四种肺螨病病原螨的扫描电镜观察

本文通过扫描电镜对四种常见的肺螨病病原螨的观察,进一步了解其颚体、足体等形态结构,为今后深入研究其形态和寄生致病关系,以及与其他种类的鉴别分类作了初步探索。     

牵张性脊髓损伤的电镜观察

利用透射电镜和脊髓血管铸型扫描电镜技术，观察兔脊髓的实验性牵张性损伤的脊髓血管立体结构和脊髓超微结构的改变。结果表明：脊髓牵张性损伤时微血管明显受损，造成供血障碍导致脊髓缺血性损伤，同时由于过度牵张而使脊髓的正常结构受到破坏，引起脊髓功能的改变。认为本方法操作简便，效果较好     

普通变形杆菌的电镜观察

本实验以扫描电镜为主,透射电镜为辅,观察了普通变形杆菌菌落和菌体的表面结构。普通变形杆菌的迁徙性菌落(波纹状薄膜)呈不规则边缘的梯状菌层,菌体排列散乱,菌体间距空隙很大。这与同样具有周身鞭毛的伤寒杆菌不同,伤寒杆菌的菌体排列十分规则,菌体之间紧密相连。与普通变形杆菌的单个菌落相比较,这种迁徒性生长现象可能是由于细菌运动活泼所致,而菌体的散乱排列,可能是变形杆菌的固有特征。     

大平并殖吸虫后尾蚴的扫描电镜观察

大平并殖后尾蚴在扫描电镜下体表及吸盘上密生单生棘。口吸盘及腹吸盘上各具有两圈感觉乳突。体表除散在有感觉乳突外,在腹面两外侧各具有一排对称性感觉乳突。     

大隐静脉曲张扫描电镜观察

取不同年龄和不同病期的大隐静脉曲张血管，在扫描电镜下观察，可见内皮细胞表面饮液泡消失，微绒毛增多，失去液体交换，影响内皮细胞营养。内皮细胞大片脱落暴露下面的平滑肌细胞。肌细胞大小粗细不等，有时排列紊乱。静脉壁外膜弹力纤维减少。认为这些变化可能影响静脉壁的弹性而与静脉曲张的发病机制、病变轻重以及病期长短有关。