In order to investigate the effect of nerve compression on neurons, the commonly used model of chronic nerve compression was produced in 48 SD rats. The rats were sacrificed in 1, 2, 3, 4, 5 and 6 months after compression, respectively. The number of neuron and ultrashruchure of alpha-motor neurons and ganglion cells of the corresponding spinal segment were examined. The results showed as following: After the sciatic nerve were crushed, the number of neuron and ultrastructure of alpha-motor neurons and ganglion cells might undergo ultrastructural changes, and even the death might occur. These changes might be aggravated as the time of crushing was prolonged and the compression force was increased. It was concluded that for nerve compression, decompression should be done as early as possible in order to avoid or minimize the ultructural changes of the neuron.
Objective To study ultrastructure and clinical significance of gastrin secretory granule in colorectal carcinoma cells. Methods The gastrin expression in colorectal carcinoma tissue and blood of 10 cases was examined by using radioimmunity analysis and immunohistochemistry. The ultrastructure of gastrin secretory granule of 10 cases, the positive of gastrin immunohistochemistry of colorectal carcinoma were examined by using immunoelectron microscopic technique. Results The gastrin concentration of the colorectal cancer group 〔（130.75 ±21.34） pg/ml〕 was significantly higher than that of control group 〔（95.63± 12.26） pg/ml〕，Plt;0.05. In 10 specimens of colorectal cancer, 5 cases were gastrin immunohistochemistry positive (+++), 4 moderate positive (++) and 1 weak positive (+). Cells in colorectal cancer were polyshaped, with unusual nucleoli different in size, concentrating on the edge, the cytoplasm mitochondrion was plentiful with vacuolates, and more secretion granules could be seen, 400-1500 nm in diameter with a clear border of membrane. There were two types of granular appearance: type A was largest in bulk size, low electrodensity was welldistributed, granular core appeared loose; type B was smaller in bulk size, high electrodensity was welldistributed, nucleus was usually compact.protein A gold (pAg) positive granules were located partially in secreting granules. pAg positive granules in highly differentiated cancer were mainly located in secreting granules of type A. pAg positive granules in low differentiated cancer were mainly located in secreting granules of type B. A part of cancer cell membrane, and inside and outside of microvillus membrane, adhering to pAg granules in line could be seen. Conclusion The colorectal carcinoma cells may synthesize and secrete gastrin themselves, which may be the mechanism of high gastrin levels in colorectal cancer. The use of gastrin antagonist and receptor antagonist may treat the patents with colorectal carcinoma.
Objective To observe ultrastructural changes of the intervertebraldisk in the corresponding area after internal fixation of spinal column. Methods Twenty-four Japanese big ear rabbits were divided into internal fixation of spinal column group (n=12) and control group (n=12). The internal fixation model was made as follows: The spinous processes and erector spinal muscle were exposed and the T10L3 spinous processes and the relevant two-side articular processes under the periosteumwere isolated. With the help of L-shaped Kirschner wires, the steel wire was threaded through the articular of T11,T12,L1 and L2, and were connected with L-shaped Kirschner wries. After 6 months of operation, the following intervertebral disk tissues were observed with transmission electeon microscope: nucleus pulposus, internal annlus fibrosus and external anulus fibrosus of L1 intervertebraldisk. The T12and L2 intervertebal disk surface structure was observedhorizontally and longitudinally with scanning electron microscope, respectively. Results After internal fixation of spinal column, the structural changes of cells in nucleus pulposus and internal annulus fibrosus occurred earlier than that in the external annulus fibrosus. Proteoglycan and special structure were found in nucleus pulposus and matix of annulus fibrosus. However, the forms of special structure in nucleus pulposus and internal layer of annulus fibrosus were different. In the degeneration matrix of intervertebral disc, the proteoglycan particles and special structure were obviously decreased. Conclusion Abnormal stress environment can result in the degeneration of intervertebral disk. There is a regular distribution of the special structure in nucleus pulposus and matrix of annulus fibrosus, which is related to biology behaviour of proteoglycan particles in the degeneration of intervertebral disk.
OBJECTIVE To investigate possibility of cartilage cultured in centrifuge tube as graft materials. METHODS: Articular chondrocytes isolated from a 3-week-old rabbit formed cartilage after cultivation for 2 weeks. Articular cartilage of humeral head, growth plate of proximal tibia and meniscus were collected from a 6-week-old rabbit. The ultrastructure of chondrocytes and extracellular matrix in the three kinds of cartilages and cultured cartilage were observed by transmission electronic microscopy. RESULTS: Cartilage cultured in centrifuge tube possessed unique ultrastructure and was similar to articular cartilage and growth plate, but it was markedly different from meniscus. The four kinds of cartilages were characteristic of respectively different chondrocytes and extracellular matrix. Cultured cartilage showed typical apoptosis of chondrocytes and "dark chondrocytes" appeared in growth plate. Condrocyte apoptosis was not seen in articular cartilage and meniscus. CONCLUSION: Cartilage cultured in centrifuge tube has unique ultrastructure and may be used as graft materials for articular cartilage and growth plate.
ObjectiveTo observe the ultrastructural changes of vasa vasorum endothelial cells in the walls of the great saphenous vein and splenic vein, and to evaluate the effect of high hydrostatic pressure and hypoxia upon vasa vasorum endothelial cells. MethodsThirty-four varicose great saphenous vein samples and splenic vein samples with portal hypertension were obtained, and the same number of normal great saphenous vein and splenic vein were used as the control groups. Semi-thin sections stained with HE staining vasa vasorum of the adventitia in great saphenous vein and splenic vein were observed for light microscopy. Samples were made into ultrathin-slices again. The ultrastructural changes of endothelial cells were observed under transmission electron microscopy. ResultsIn varicose great saphenous veins and diseased splenic veins, the nuclear architecture of endothelial cells in vasa vasorum were integrity and the distribution of chromatin were normal. In some mitochondria, the trachychromatic groundplasm, undefined and ruptured cristae were found. ConclusionUnder high hydrostatic pressure and hypoxia conditions, the ultrastructure of vasa vasorum endothelial cells between the great saphenous vein and the splenic vein may appear remodeling phenomenon, and both changes are similar.
Polypoidal choroidal vasculopathy (PCV) is originally defined as a separate disease, but with the development of imaging techniques, it has now been included in the spectrum of neovascularization. In the Asian population, the prevalence of PCV is high, and with the deepening of clinical studies, the pathological characteristics, pathogenesis and clinical manifestations of PCV have been more deeply understood. Through dynamic observation and histopathological study of PCV lesions during operation, it can be confirmed that the lesions are mainly located between the retinal pigment epithelium and the Bruch membrane, rather than originating from the choroidal circulation, which is of great significance for understanding the origin and natural course of PCV. It is worth noting that although a theoretical bridge has been established between age-related macular degeneration (AMD)/PCV, there is a lack of intuitive clinical data on the ultrastructural and molecular manifestations of the cells/stroma in the local lesions of the eye, especially the progression of AMD/PCV from early/middle stage to exudative stage. It is precisely because of this that highly attractive research topics and exploration space are proposed for the future.
Objective To observe the relationship of osteoblasts, endothelial cells and ceramic scaffold during reconstruction of rat critical size calvarial defects with tissue engineering technique under transmission electron microscope. Methods Fourteen male adult Sprague Dawley rats were divided randomly into experimental and control groups. Bone marrow was obtained from left femurs and tibias of all rats. In experimental group, respective autogenous osteoblasts derived from bone marrow stromal cells(MSCs) different iated and proliferated in vitro and then were seeded and subcultured on porous calcium phosphate ceramics. The cell-ceramic compounds were used to repair critical-sized (8 mm diameter) calvarial defects in the corresponding rats. In control group, the ceramic without autogenous osteoblosts was used. One rat of each group was sacrificed postoperatively in the 4th, 8th, 12th, 24th, 28th weeks respectively and involved samples were removed to make decalcified ultrath in sections and observed under transmissionelectron microscope. Results Osteoblasts or osteoblast-like cells always located next to sprouting capillaries and the relationship between osteoblasts and endothelial cells was relevant in experimental group. There was a calcium depositzone distributed along the boundary of newly formed bone and the remnants of decalcified ceramic, which meant osseointegration between the ceramic and newly formed bone. The above changes did not appear in control group simultaneously.Conclusion The nanometer scale structure of ceramic scaffold benefits to angiogenesis, osteogenesis and extracellular matrix formation in repair bone defects with tissue engineering technique.
Objective To isolate，culture and expand bone marrow mesenchymal stem cells （MSCs） in vitro，induce MSCs to differentiate directionally towards chondrocytes，and provide experimental basis for clinical application of MSCs and construction of tissue engineering tracheal cartilage. Methods Cultured MSCs were isolated from bone marrow of Sprague-Dawley rats，purified using adherence separation，and identified by flow cytometry analysis. Transforming growth factor β1 （TGF-β1）and insulin-like growth factor 1 （IGF-1） were used as main induction factors to induce MSCs to differentiate directionally towards chondrocytes. The expression of collagen typeⅡwas evaluated by immunocytochemical staining 21 days after induction. Light microscope and electron microscope were used to observe tiny and ultrastructural changes of the cells before and after induction. Results The expression of collagen typeⅡwas positive by immunocytochemical staining 21 days after induction. MSCs were fusiform before induction under light microscope and electron microscope. After induction，the cells became larger，polygon，star-shaped or triangular. Transmission electron microscope showed that the cells had abundant organelles，larger nuclei and more nucleoli after induction. Conclusion Abundant organelles，larger nuclei and more nucleoli are the ultrastructure changes of chondrocytes differentiated from MSCs，indicating that the cells are active in differentiation and metabolism.
In order to study the influence of severity of tendon injury on the morphology of collagen fibers during healing process of extensor tendons, 40 female Wistal rats were used for investigation. The rats were divided into 2 groups. Transection of the tendon of extensor digitorum longus was performed in one group, while partial section of the same tendon was performed in the other group. Morphometric analysis was undertaken on the 15th, 30th, 60th and 90th day after operation. The result was that there was no significant difference between the two groups both in distribution and diameter of collagen fibers on the 15th and 30th days (P gt; 0.05). However, there was significent difference between those on the 60th and 90th days (P lt; 0.05). It was concluded that the severity of the tendon injury could influence the morphology of collagen fibers during the late stage of tendon healing.
OBJECTIVE: To study the characteristics of, morphology histology and ultrastructure of anterior cruciate ligament(ACL) autograft and two-step cryopreserved ACL allograft after transplantation. METHODS: Sixty New Zealand rabbits and sixty Japanese rabbits were randomly divided into two groups: ACL autograft group and two-step cryopreserved ACL allograft group. Immunosuppressant were not used after transplantation. The histology and ultrastructure of the ACL of transplantation and normal knee were observed after 4 weeks and 12 weeks, respectively. RESULTS: The rate of remodeling process was faster in ACL autograft than in two-step cryopreserved ACL allograft, but there was similar remodeling process between two groups 12 weeks after transplantation. The proportions of large-diameter fibers(gt; or = 80 nm) of ACL autograft and cryopreserved ACL allograft were 6% and 24% in the 4th week, and were 0 and 2% in the 12th week, respectively. The proportions of small-diameter of fibers(lt; 80 nm) of ACL autogrft and cryopreserved ACL allograft were 94% and 76% in the 4th week, and 100% and 98% in the 12th week, respectively. Histologic incorporation in ACL autograft was similar to that in cryopreserved ACL allograft. CONCLUSION: Two-step cryopreserved bone-ACL-bone allograft were similar to bone-ACL-bone autograft cryopreserved in remodeling process and histology. The rate of remodeling process was faster in ACL autograft than in cryopreserved ACL allograft.