ABSTRACT
BACKGROUND: As a result of immature brain of children and their imperfect blood brain barrier, improper clinical treatment would affect growth and development of children. It is fully important to perform further investigation on immature brain injury induced neurodegeneration.OBJECTIVE: To observe the ultramicrostructure of neurons in homolateral parietal cortex and hippocampus in newborn 7-day SD rat with contusion of parietal cortex.DESIGN: Completely randomized controlled trial.SETTING: Laboratories of Nerve Morphology and Cytobiology, Medical College of Shanghai Jiaotong University; Electron Microscope Room of Institute for Physiology, Chinese Academy of Science.MATERIALS: The experiment was performed in Teaching and Research Section of Anatomy, Laboratories of Nerve Morphology and Cytobiology ofShanghai Second Medical University (Medical College of Shanghai Jiaotong University; Electron Microscope Room of Institute for Physiology of Chinese Academy of Science from October 2002 to June 2003. A total of 19newborn 7-day SD rats were randomly divided into experimental group, operation control group and normal control group with 15, 2 and 2 in each group respectively.METHODS: In experimental group, free-fall device for brain injury was used for establishing model of contusion of parietal cortex in newborn 7-day SD rat. Anesthesia and scalp incision were conducted, without using free-fall device in operation control group. But above procedures were not carried out in normal control group. The changes of ultramicrostructure were observed under transmission electron microscope after routine treatment of electron microscopic samples.MAIN OUTCOME MEASURES: Ultramicrostructure of neurons in homolateral parietal cortex and hippocampus.RESULTS: All the 19 rats entered results analysis. ① There were two sorts of morphological changes in neurons in experimental group. One was evident swelling of dendrites and bodies of neurons, accompanied with the changes of organelles. In the early stage, expansion of endoplasmic reticulum cisterna could be observed and mitochondria became compact and concentrated. Then, vacuolization of endoplasmic reticulum, progressive swelling and vacuolization of mitochondria, dissociation of polysomes from rough endoplasmic reticulum and scattering of them in cytoplasm could be seen. Changes of nucleolus presented after significant changes of cytoplasm. Nuclear chromatin clustered together under karyotheca and arranged as clockface, which were some masses with irregular contours gathering to the center. Axons were almost normal. The other was concentration of cytoplasm and nucleolus with vacuolizations of unequal size in cytoplasm. ②There was no abnormal change in neurons in homolateral parietal cortex and hippocampus both in operation control group and normal control group.CONCLUSION: Swelling of brain cell and concentration of cytoplasm and nucleolus after brain injury play important roles in brain injury-induced neurodegeneration of immature rats.
ABSTRACT
Popliteal fossa dissections were performed on two hundred adult extremities and the patterns of the deep venous system were observed. Three general types were established for the popliteal vein and its branches. Single large trunk representing the popliteal vein at the level of the knee joint occurs only in 32.00％, two venous trunks at this level in 65.50％ and three venous trunks in 2.50％. Furthermore, considerable variations of the formation of popliteal veins were found. The patterns of popliteal vein were divided into three main types and eleven subtypes. Type Ⅱa occurs most frequently (41.50％). The size of each vein of the deep venous system was measured. The average calibre of the single popliteal vein is 6.89mm (ranging between 4.0-11.5 mm). The veins from the gastrocnemius muscle join the single or the two popliteal trunks respectively. The veins of the soleus muscle drain into the peroneal and posterior tibial veins. The short saphenous vein typically terminates in the popliteal vein. Variations in its termination were described.
ABSTRACT
The structure of the articular cartilage and disc of the temporomandibular jointin rats and monkey were studied with light,transmission and scanning electronmicroscopy.The articular cartilage covering the mandibular condyle is semilunar in shapeon cross section.Its thickest portion lies posterosuperiorly.The bony trabeculaesubjacent to the cartilage arrange vertically to the articular surface and concentrateto the thickest portion of the articular cartilage.The articular cartilage covering the mandibular fossa is similar to that on themandibular condyle,but contains fewer cartilage cells.Lacking a calcified areawith enlarged cartilage cells,the articular cartilage here may only be divided intothree areas.The articular disc consists of three areas:an upper,a middle,and a lowerone.The structure and ultrastructure of different parts of these cartilages with theirfunctions have been discussed.
ABSTRACT
After removal of unilateral molars in the rats,the changes in the articularcartilage and articular disc of the temporomandibular joint and HRP uptake of thelining cells of synovial membrane were observed with light,transmission and scanningmicroscopy.The HRP uptake activity of the lining cells was lowered and degenerative chan-ges were presented in ths articular cartilages following the removal of the molars.It is suggested that the temporomandibular joint is intimately integrated with theocclusion of the upper and lower teeth.Defect of the teeth on one side mayinduce occlusion disorders.These will certainly cause some changes of the structureand function of the temporomandibular joint.