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BACKGROUND: Changes of elastic fibers in middle cerebral artery(MCA)is close related withthe aged cerebrovascular disease.OBJECTIVE: To observe the changes of elastic fibers of MCA in different aging rats.DESIGN: A descriptive and controlled study based on experimental animals.SETTING: Department of anatomy and central laboratory in a university.MATERIALS: Totally 36 healthy Wistar rats with either gender, weighing 200 - 280 g, were selected from the Animal Institute of the third medical military university of Chongqing[certification SCXX (army) 2002-007].INTERVENTIONS: Changes of elastic fibers of MCA of different aging rats were observed with light microscope, transmission electron microscope and image analysis system. MAIN OUTCOME MEASURES: ①) Major outcome: changes of elastic lamella in MCA of different aging rats; ②) Secondary outcome: ultramicrostructural changes of internal lamella under the transmission electron microscope. RESULTS: With the increase of age, the folded extent and quantity of internal elastic lamella were decreased, and the content of elastic fibers were also decreased significantly( P ＜ 0.01 ). However, the ratio of collagen fibers to elastic fibers was increased significantly( P ＜ 0.01 ) . In the aging group above 24 months, the internal elastic lamina thinned, delaminated and disrupted, and the lipid deposited in it. Endothelial cells and smooth muscle cells passed through the internal elastic lamina. CONCLUSION: Changes of elastic fibers may be related with the increased susceptibility to the cerebrovascular disease in aged people.
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Objective To analyze the clinical and neuropathological characteristics of subacute combined degeneration (SCD) of the spinal cord. Methods The clinical data were collected in 38 cases of SCD. The serum levels of Vitamin B 12 and folic acid in 34 cases and the serum homocysteine levels in 15 cases were determined. The sural nerves in 4 patients were observed by light and electron microscopes. Results The levels of vitamin B 12 in 25 cases and levels of folic acid in 7 cases were lower than normal value, but the levels of homocysteine in 6 cases were higher than the normal value. Pathological examination showed that there were different degrees of segmental loss of myelin sheaths and axonal degeneration in the peripheral nerves in 4 cases. Conclusion The diagnosis of SCD depends on clinical and laboratory data. The biopsy of the sural nerve shows that the main lesion is the loss of myelin sheaths.
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Objective To observe the repair effect of human ?-defensin 2 (hBD 2)-modified rat dermal multipotent stem cells (dMSCs) transplantation on infected wound. Methods Thirty Wistar rats were excised a piece of whole-layer back skin, 3 mm in diameter, then infected the wound with 1?10 8/ml pseudomonas aeruginosa 1 ml, then the rats were injected on the wounded back respectively with dMSCs modified by hBD 2 (n=10), or pure dMSCs (n=10) or none as control (n=10). The repair effect was evaluated by observing the amount of bacteria under the scar, wound healing time and the percentage of remaining wound area. Results The amount of bacteria under the scar in rats that were transplanted with dMSCs modified by hBD 2 was less than that in rats transplanted with dMSCs or controls (P
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The present experimental study was carried out to investigate the effect of indogenous prostaglandeins produced in the peripheral nerves after injury and the action of indomethacin ( a prostaglandin synthesis inhibitor) on their regeneration on the animal models with sciatic nerve crushed. The main results were: 1 , Radioimmunoassay demonstrated a stepladder-like increase in PGF 2 alpha in the sciatic nerve after crushing injury ; 2 , light microsocpy showed the number, diameter and area of the cross section of regenerated, myelinated nerve fibers passing through the crushed segment of the tibial fascicle of sciatic nerve of the rabbits being more than those injected with normal saline ; 3 , Culture of dissociated dorsal ganglia root cells from newborn rabbits revealed that nerve cells grown in media containing PGF 2 alpha showed significantly smaller size, less number of regenerated processes and lower content of RNA than those grown in media containing indomethacin. Scanning electronmicroscopy demomstrated different surface morphological features. These results indicated that an excess prostaglandin was produced in the rcushed nerve and inhibited nerve regeneration. Indomethacin as a prostaglandin synthesis inhibitor prevented excessive prostaglandin formation to promote nerve regeneration.
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Objective To investigate the ultrastructural changes of hippocampus in the guinea pigs with chronic asthma and the effects of hypoxia treatment on the hippocampal ultrastructures. Methods The replicated animal model of chronic asthma was divided into hypoxia(low pressure chamber) treatment group, normal pressure hypoxia inhaling treatment group, non treatment group and control group. The ultrastructural changes of hippocampus were observed with electron microscope. Results Expanded rough endoplasmic reticulum, ruptured cloudy mitochondrion carina, decreased synaptic vesicles and swollen postsynaptic membrane, proliferation of astrocytes and microglia proliferated, swelling of cytoplasm, vacuolation, broadened milieu interspace of blood vessels, swelling of cloudy basement membrane with constricted duct cava were found. After hypoxia, clear neuron nucleoli, plenty organells, slightly expanded rough endoplasmic reticulum, fairly plenty synaptic vesicles, more dense post synaptic membrane and slightly broadened synaptic space were also found. No apparent pathologic changes were found in glial cells and the blood vessels. Conclusion Recurrent chronic asthma may result in the ultrastructural changes of hippocampus due to hypoxia. Treatment with low pressure hypoxia and normal pressure hypoxia may be helpful to the improvement of ultrastructural injury of hippocampus due to asthma.
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The repair process of the iibial fascicle of the rabbit sciatic nerve which had been transected and sutured or simply crushed was studied by means of light and . electron microscopy.It was found that the perineurium was able to heal after the nerve had been transected and sutured through the formation of a new epineurium-perineurium tube which contained many minute fascicles of regenerated nerve fibers. The newlyformed epineurium-perineurium tubs rejoined ths two stumps of the transected epineurium theath perineurium tube. The healing process of the nerve fascicle after crushing was similar to that after transection and suturing.From the transection and suturing of the nerve to the formation of the new epineurium-perineurium tubs the sequence of pathological events occurring in the epineurium and perineurium could be divided into 3 stages, the first stage of trau-matic inflammation, degeneration and necrosis of the perineurium, the second stage of perineurial cell proliferation, and the regeneration nerve fiber growth into the pre-perineurium mass and the third stage of the formation of new small nerve fascicles.The formation of the new epineurium-perineurium tube is of vital importance to nerve regeneration, it can prevent the nerve fibers from growing astray and guide them to the distal perineurium tube. The pro-perineurial cells might originate from the proliferation of the perineurial cells, themselves.The normal histological and ultrastructural morphology of the rab bit sciatic nerve was described. The nuclei of the perineurial cells have the tendency to form palisades. It seems that this may explain the palisading of the nuclei of neurofibr-oma cells.
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An autopsy-confirmed case of neuro-Behcet's disease was reported with a review of the incidence, etiology, pathological changes, clinical manifestations, diagnosis, treatment and prognosis of the condition.The lesions of this case were widely distributed, involving the skin, eyes, mouth, genital organ, peripheral blood vessels, liver and central nervous system. The lesions of the central nervous system were mostly located in the cerebrum. A correct clinical diagnosis of neuro-Behcet's disease may be missed or delayed when its neurological symptoms and signs are the first or main manifestations and the other symptoms appear rather late or mild. On the basis of a definite diagnosis of Behcet's disease, the possibility of neuro-Behcet's disease should always be considered especially in patients with disturbances of the nervous system. The pathological diagnosis of neuro-Behcet's disease must be correlated with the clinical manifestasions. And in making the diagnosis, other nervous system disease, especially demyelinating disease euch as multiple sclerosis, acute disseminated ence-phalomyelitis and neuromyelitis optica should be ruled out.No autopsy-confirmed case of neuro-Behcet's disease has ever been reported in China and thie is likely to be the first case
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Objective To examine the expression of human ?-defensin 2 (hBD_ 2 ) recombinant adenovirus expression vector in rat dermal multipotent stem cells (dMSCs) and to observe the antiseptic activity of recombinant hBD_ 2 . Methods The expression of hBD_ 2 in dMSCs was examined by RT-PR, fluorescent immunochemistry and Western blotting, and the concentration of recombinant hBD_ 2 in supernate was measured by ELISA. The antiseptic activity of recombinant hBD_ 2 was assessed by K-B disc agar diffusion test. Results hBD_ 2 could be effectively expressed in dMSCs, and the concentration of recombinant hBD_ 2 in supernate was about 743.6 ng/ml . Recombinant hBD_ 2 in supernate showed antiseptic activity. Conclusion Recombinant adenovirus expression vector of hBD_ 2 could be effectively expressed in dMSCs, and the recombinant hBD_ 2 in supernate showed obvious antiseptic effects toward some standard bacteria lines.
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Eight cases of human rabies encephalomyelitis confirmed by autopsy were reported. They all had a history of rabid dog bite and typical clinical manifestations of rabies. The mean clinical course ran about 4 days. The most frequent pathological findings were the appearence of intracytoplasmic Negri bodies in neuron and paren-chymal inflammation of the brain and spinal cord. The inflammatory response was more prominent in the brainstem, hippocampus and spinal cord, consisting of peri-vascular cuffs of lymphocytes and monocytes, foci of softening microglial response and neuronophagia. Negri bodies were found in all of the sections taken from the brain, especially frequently found in the purkinjs cells of the cerebsll um and the pyramidal cells of the hippocampi in all the eight cases.The pathodiagnostic principles of this disease, and its differentiation from type B encephalitis and polimyelitis were briefly discussed. The relation between the site of the dog bite and the distribution of the lesions and the duration of the incubation period were also discussed.