Carotid atheroscleorotic stenosis is one of the most common causes of cerebral ischemic stroke. In China, unfortunately, Its importance has not been fully stressed,and carotid endarterectomy hasn't been used widely so far. Therefore, noninvasive studies on carotid atheroscleorotic stenosis are introduced. The surgical and intravascular interventional therapies are emphasized again.

Objective To study the advantages and procedure of telovelar approach for resection of the lesion in the fourth ventricle. Methods Telovelar approach to the fourth ventricle was executed in 17 cases. Among these patients, seven were females and 10 were males. The age ranged from 5 years to 49 years with mean age of 26.6 years. Pathologically, there were 5 medulloblastomas, 5 ependymomas, 2 epidermoids, 2 brain cysticercosis, and 3 choroid plexus papillomas. During the operation, the medullotonsillar space of the cerebellomedullary fissure and the urulotonsillar space were sharply dissected to release the tonsils from uvula and medullar oblongata bilaterally. According to the size of the neoplasm, the tela or both tela and velum were incised. The fourth ventricle was exposed adequately and the lesion was removed. All operations were performed with the help of microscope. The dura was sutured securely. Results The space occupying lesions were removed totally in all cases and all patients recovered very well, and threre was no mortality or serious disability. With 3 to 21-month follow-up in 11 cases, no death or serious disability was found, and the CT or MRI in 8 patients showed no recurrence. Conclusion The telovelar approach can provide adequate exposure to remove the lesion in the fourth venticle. The inferior vermis need not be incised, so a minimum amount of brain tissue was injured, and postoperative complication is decreased.

Objective To study the role of VEGF on the growth of hypertensional saccular aneurysm and its mechanism. Methods Twenty-four SD rats were divided into 2 groups randomly (A and B, each with 12 rats). Saccular aneurysms of the carotid artery were reproduced by treatment of initial segment of the external carotid artery (1mm long) with elastase. In group A, the posterior branches of both renal arteries were ligated in order to produce marked elevation of blood pressure. In Group B hypertension was not produced to serve as the control group. After 8 weeks, the blood pressure and the size of the aneurysms were measured. Then formalin was infused into the arteries for fixation, and aneurysms were resected. The expression of vascular endothelial growth factors (VEGF) in aneurysmal wall was assessed with immunohistochemical analysis. Results The size of aneurysms: after 8W, significant difference was found between A and B group (P

s Objective To observe the changes in the expression of ?-amyloid precursor protein (?-APP) in selected brain areas in early stage of diffuse axonal injury (DAI) in rats. Methods DAI was induced in SD rats by a self-made rotating injury device. 16 rats in injury group were sacrificed by decapitation at 3 hours and 6 hours post-trauma, while the other 8 rats in sham injury group were put to death after 24 hours. The samples of the rat brain were stained with ?-APP for immunohistochemistry in order to detect the early stage pathological changes in subcortex white matter, hippocampus, corpus callosum and brain stem at different time points. Results The ?-APP expression was positive at 3 hours and was particularly strong at 6 hours after injury. The results of semi-quantitative analysis showed a significant differentiation of 3 hours and 6 hours in the immuno-positive expression of brain stem, corpus callosum and hippocampus. Histological results demonstrated that DAI occurred in all rats of injury group. Conclusion ?-APP is a kind of sensitive and useful immunochemical marker for early DAI diagnosis, and it indicates axonal lesion or breakage.

Objective To observe the dynamic changes in neuroglobin (NGB) expression in cerebral cortex and hippocampus after cerebral ischemia-reperfusion injury in gerbils. Methods The global cerebral ischemia of gerbils was induced by clamping bilateral carotid arteries for 20 minutes, then they were released to allow reperfusion for 2h, 8h, 16h, 24h, 48h and 72h. The NGB expression in cerebral cortex and hippocampus was measured with immunohistochemical methods coupled with computer-assisted image analysis. Results The changes in NGB expression were different in cerebral cortex and in the hippocampus. NGB protein was up-regulated from 16h to 48h after ischemia-reperfusion insult to cerebral cortex, whereas it was down-regulated hippocampus. Conclusion The different expressions of NGB in cerebral cortex and hippocampus are suggestive of compensatory and repair mechanisms in ischemia-damaged neurons after transient global cerebral ischemia. The increased expression of endogenous NGB in the brain after ischemia-reperfusion may be associated with the protective response to ischemic damage.

The aim was to look for the method for getting highly purified population and large amount of Schwann cells from the newborn rats. Sciatic nerves from 1～3 days old SD rats were taken out . The Schwann cells were cultured and purified by modified repeated explanation, and fibroblastic cells were removed by rapid trysinization , differential adhesion and anti mitosis methods. The Schwann cells were identified by indirect immunocytochemistry with mouse anti S 100 protein McAb. The result showed that the purity of Schwann cells was more than 95%, and the cells were in a good state. It is considered that the methods are simple and convenient , and a great number of highly purified Schwann cells can be acquired by them.

To correlate the ultrasound and MR imaging of carotid atherosclerotic plaque with its histologic compositions,20 patients(22 lesions) scheduled for carotid endarterectomy were examined by B mode ultrasound and MRI preoperatively. The specimens were also examined postoperatively and the images of carotid plaque were recorded. The transverse pathological sections of plaques were made and matched with images of ultrasound and MRI. 256 gray scale ultrasound densitometric analysis of carotid plaque compositions was performed. Ultrasonic density of calcium, fibrous tissue, hemorrage/thrombus and lipid deposits was (89?12), (53?8), (37?6) and (39?3) respectively in vivo , and was (168?11), (136?12), (85?12) and (89?10) respectively in vitro . In vivo relative signal intensities of calcium, fibrous tissue, old hemorrhage/thrombus and lipid deposits were low, equal, equal and very high respectively on T 1 W MR image, and very low, equal, high and high respectively on PDW MR image, and low, equal or slightly high, high and high respectively on T 2 W MR image. Signal intensities of plaque contents ex vivo were correlated to signal intensities in vivo. Densitometric analysis of ultrasound images of carotid plaques can quantify possible components of plaque, and MRI has the feasibility to identify the components of plaque.

To study the distribution of two different phenotype mast cells in atherosclerotic lesions of human carotid arteries, 32 samples of endarterectomy and 10 autopsies of normal carotid specimens were fixed and embeded in paraffin, sections were stained with hematoxylin-eosin, toluidine blue,monoclonal antibodies against the two major proteases of mast cells(tryptase and chymase) and monoclonal antibodies against CD-3 of T lymphocytes and CD-68 of macrophages. The quantity,distribution and degranule of two different phenotype mast cells in atherosclerotic lesions of human carotid arteries were investigated,and the ratio of mast cells to T lymphocytes and macrophages in atherosclerotic lesions was calculated. The density(cells/mm 2 ) of mast cells in shoulder region of plaque(6 3?4 0) was much higher than that in normal intima,cap and core region(1 3?2 3,2 3?2 6,2 2?3 7) .The proportion of chymase-containing mast cells to tryptase-containing mast cells was 0 36,0 51,0 47 and 0 39 respectively in normal intima,cap,core and shoulder region of plaque.The propotion of degranulated mast cells was the highest in shoulder region of plaque(65%).The ratios of mast cells to T lymphocytes and to macrophages were 0 25 and 0 14 respectively in shoulder region of plaques.Light microscopic studies of mast cells revealed that mast cells were more commonly observed in thrombus and around calcification and blood vessels of plaque.Mast cells play a role in the formation of plaque,and participate in the destabilization of plaque.

To assess the indication, intraoperative monitoring with selective shunting and surgical outcomes of carotid endarterectomy for patients with contralateral carotid occlusion, the clinical manifestations, imaging data, surgical methods and results of 16 patients were analysed retrospectively. It was verified that the surgical risk of these patients was not as high as prediction,satisfactory results coold be achieved with intraoperative monitoring, selective shunting and skilled surgical techniques. It is reasonable to offer the following typical treatment examples: Carotid endarterectomy should be performed for patients with symptomatic carotid stenosis irrespective of the contralateral carotid occlusion, while medical therapy should be maintained for patients with asymptomatic carotid stenosis and contralateral carotid occlusion. maintained. If the asymptomatic stenosis is found to be progressing in noninvasive testing, then a prophylactic endarterectomy should be considered.

Exposure of the distal internal carotid artery is very important and difficult in carotid endarterectomy for patients with high bifurcations or extension of the atherosclerotic plaque into the distal internal carotid artery. Exposure techniques are introduced based on the surgical experiences of 28 cases.