Objective To elucidate the influence of osteoporosis on the fracture healing in ovariectomized rat. Methods 24 females 8-month-old SD rats were divided randomly into two groups.12 were sham-operated(Sham)and 12 were b...Objective To elucidate the influence of osteoporosis on the fracture healing in ovariectomized rat. Methods 24 females 8-month-old SD rats were divided randomly into two groups.12 were sham-operated(Sham)and 12 were bilaterally ovariectomized(OVX) 3 months later.The femoral fracture model were made in both groups,the healing process was observed by transmission electron microscopy(TEM) on d3,d7,d14,d21,d28,and d42 after making fracture in control groups(Sham) and the osteoporosis group(OVX). Results According to the TEM findings,the types of fracture healing cells,their ultrastructure changes and functional states were almost identical in both groups till d21 after making fracture.In OVX group,the calcified cartilage was not resorbed and replaced by new woven bone,a lot of necrosis chondrocytes were found being embedded in a calcified chondroid matrix on d28;after this period,osteoclastic bone resorption become severe gra- dually accompanied by osteocytic osteolysis during d28 to d42 of fracture healing. Conclusion Osteoporosis greatly affect the fracture healing in the later period of healing proess.It demonstrated as endochondral bone formation delayed and increased osteoclastic bone resorption which was made even more severed by osteocytic osteolysis during the period of bone callus remodelling.展开更多
Micro- injury （exercise-induced muscle damage, EIMD） will cause a temporary decline in muscle function, if not handled properly, it could cause more serious injury or overtraining, and even lead to the end of the at...Micro- injury （exercise-induced muscle damage, EIMD） will cause a temporary decline in muscle function, if not handled properly, it could cause more serious injury or overtraining, and even lead to the end of the athletes ＇ sports life. However, some studies have shown that an appropriate period of eccentric exercise training resulted in EIMD while promoted heart muscle fiber hypertrophy and corresponding muscle growth faster than exercise training, and there are the typical ＂ repetitive training effect＂ , ie after a period of the EIMD recovery, the muscle＇ s injury or delayed onset muscle soreness （DOMS） caused by the same movement is significantly reduced. So its deep study could help to guide the athlete to avoid or mitigate the negative effects which brought by EIMD, while could help to further clarify the process of the body to adapt to exercise training or mechanism.展开更多
To investigate the effect of moderate hypothermia on respon ses of axonal cytoskeleton to axonal injury in the acute stage of injury. Methods: Of fifteen adult guinea pigs, twelve animals were subj ected to stretch in...To investigate the effect of moderate hypothermia on respon ses of axonal cytoskeleton to axonal injury in the acute stage of injury. Methods: Of fifteen adult guinea pigs, twelve animals were subj ected to stretch injury to the right optic nerves and divided into the normother mic group (n=6) in which the animals core temperature was maintained at 36.0 37.5℃ and the hypothermia group (n=6) in which the core temperature was red uced to 32.0 32.5℃ after stretch injury. Remaining three animals sustained no injury to the right optic nerves and served as control group. Half of injure d animals (n=3) of either normothermic group or hypothermic group were killed at either 2 hours or 4 hours after injury. The ultrastructural changes of axonal c ytoskeleton of the right optic nerve fibers from the animals were examined under a transmission electron microscope and analyzed by quantitative analysis with a computer image analysis system. Results: At 2 hours after stretch injury, there was a significa nt reduction in the mean number of microtubules (P< 0.001 ), and a significant increase in the mean intermicrotubule spacing (P< 0.05 or P< 0.01 ) in axons of all siz es in normothermic animals. The mean number of neurofilaments also decreased sta tistically (P< 0.01 ) in large and medium subgroups of a xons in the same experimental group at 2 hours. By 4 hours, the large subgroup o f axons in normothermic animals still demonstrated a significant decline in the mean number of microtubules (P< 0.01 ) and an increase i n the mean intermicrotubule spacing (P< 0.05 ), while th e medium and small subgroups of axons displayed a significant increase in the me an number of neurofilaments (P< 0.05 ) and reduction in the mean interneurofilament spacing (P< 0.05 ). On the c ontrary, either the mean number of microtubules and the mean intermicrotubule sp acing, or the mean number of neurofilaments and interneurofilament spacing in ax ons of all sizes in hypothermic stretch injured animals was not significant dif ferent from the mean values of sham operated animals. Conclusions: Posttraumatic moderate hypothermia induced immedia tely after axonal injury results in substantial protection of axonal cytoskeleto n and ameliorates axonal damage.展开更多
Objective: To study the effects of occlusal trauma on the ultra structure of synovial membrane and articular cartilage in rabbits temporomandibular joints (TMJ). Methods: TMJs from six rabbits with occlusal trauma and...Objective: To study the effects of occlusal trauma on the ultra structure of synovial membrane and articular cartilage in rabbits temporomandibular joints (TMJ). Methods: TMJs from six rabbits with occlusal trauma and three control rabbits were studied by transmission electron microscopy. Results: Degenerative changes in synovial membrane and articular cartilage of TMJ were induced following occlusal trauma. The structure of the articular surface was damaged, and chondrocytes in cartilage showed signs of degeneration. The synovial lining cells contained dense accumulations of vimentin intermediate filaments (IFs), which were especially prevalent in the cellular processes as well as paranuclearly. Microvilli on the synovial cell membrane were commonly seen. The “vermiform bodies” in the deeper interstitium of the synovial tissue were also found. Our findings of the punctate adherens between synovial lining cells were described in detail. Conclusions: The occlusal trauma is really a factor inducing degenerative changes of the TMJ.展开更多
文摘Objective To elucidate the influence of osteoporosis on the fracture healing in ovariectomized rat. Methods 24 females 8-month-old SD rats were divided randomly into two groups.12 were sham-operated(Sham)and 12 were bilaterally ovariectomized(OVX) 3 months later.The femoral fracture model were made in both groups,the healing process was observed by transmission electron microscopy(TEM) on d3,d7,d14,d21,d28,and d42 after making fracture in control groups(Sham) and the osteoporosis group(OVX). Results According to the TEM findings,the types of fracture healing cells,their ultrastructure changes and functional states were almost identical in both groups till d21 after making fracture.In OVX group,the calcified cartilage was not resorbed and replaced by new woven bone,a lot of necrosis chondrocytes were found being embedded in a calcified chondroid matrix on d28;after this period,osteoclastic bone resorption become severe gra- dually accompanied by osteocytic osteolysis during d28 to d42 of fracture healing. Conclusion Osteoporosis greatly affect the fracture healing in the later period of healing proess.It demonstrated as endochondral bone formation delayed and increased osteoclastic bone resorption which was made even more severed by osteocytic osteolysis during the period of bone callus remodelling.
文摘Micro- injury （exercise-induced muscle damage, EIMD） will cause a temporary decline in muscle function, if not handled properly, it could cause more serious injury or overtraining, and even lead to the end of the athletes ＇ sports life. However, some studies have shown that an appropriate period of eccentric exercise training resulted in EIMD while promoted heart muscle fiber hypertrophy and corresponding muscle growth faster than exercise training, and there are the typical ＂ repetitive training effect＂ , ie after a period of the EIMD recovery, the muscle＇ s injury or delayed onset muscle soreness （DOMS） caused by the same movement is significantly reduced. So its deep study could help to guide the athlete to avoid or mitigate the negative effects which brought by EIMD, while could help to further clarify the process of the body to adapt to exercise training or mechanism.
文摘To investigate the effect of moderate hypothermia on respon ses of axonal cytoskeleton to axonal injury in the acute stage of injury. Methods: Of fifteen adult guinea pigs, twelve animals were subj ected to stretch injury to the right optic nerves and divided into the normother mic group (n=6) in which the animals core temperature was maintained at 36.0 37.5℃ and the hypothermia group (n=6) in which the core temperature was red uced to 32.0 32.5℃ after stretch injury. Remaining three animals sustained no injury to the right optic nerves and served as control group. Half of injure d animals (n=3) of either normothermic group or hypothermic group were killed at either 2 hours or 4 hours after injury. The ultrastructural changes of axonal c ytoskeleton of the right optic nerve fibers from the animals were examined under a transmission electron microscope and analyzed by quantitative analysis with a computer image analysis system. Results: At 2 hours after stretch injury, there was a significa nt reduction in the mean number of microtubules (P< 0.001 ), and a significant increase in the mean intermicrotubule spacing (P< 0.05 or P< 0.01 ) in axons of all siz es in normothermic animals. The mean number of neurofilaments also decreased sta tistically (P< 0.01 ) in large and medium subgroups of a xons in the same experimental group at 2 hours. By 4 hours, the large subgroup o f axons in normothermic animals still demonstrated a significant decline in the mean number of microtubules (P< 0.01 ) and an increase i n the mean intermicrotubule spacing (P< 0.05 ), while th e medium and small subgroups of axons displayed a significant increase in the me an number of neurofilaments (P< 0.05 ) and reduction in the mean interneurofilament spacing (P< 0.05 ). On the c ontrary, either the mean number of microtubules and the mean intermicrotubule sp acing, or the mean number of neurofilaments and interneurofilament spacing in ax ons of all sizes in hypothermic stretch injured animals was not significant dif ferent from the mean values of sham operated animals. Conclusions: Posttraumatic moderate hypothermia induced immedia tely after axonal injury results in substantial protection of axonal cytoskeleto n and ameliorates axonal damage.
文摘Objective: To study the effects of occlusal trauma on the ultra structure of synovial membrane and articular cartilage in rabbits temporomandibular joints (TMJ). Methods: TMJs from six rabbits with occlusal trauma and three control rabbits were studied by transmission electron microscopy. Results: Degenerative changes in synovial membrane and articular cartilage of TMJ were induced following occlusal trauma. The structure of the articular surface was damaged, and chondrocytes in cartilage showed signs of degeneration. The synovial lining cells contained dense accumulations of vimentin intermediate filaments (IFs), which were especially prevalent in the cellular processes as well as paranuclearly. Microvilli on the synovial cell membrane were commonly seen. The “vermiform bodies” in the deeper interstitium of the synovial tissue were also found. Our findings of the punctate adherens between synovial lining cells were described in detail. Conclusions: The occlusal trauma is really a factor inducing degenerative changes of the TMJ.
