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.

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.

To evaluate clinical effect of transcranial optic nerve decompression on fronto orbito sphenoidal fibrous dysplasia with progressive vision loss, 25 cases were studied retrospectively. All patients had undergone transcranial optic nerve decompression. One week after operation, 21 patients experienced improvement or stability in vision, but 4 patients complained reduction in vision. Before operation, the vision of the affected eye was near blindness in 3 cases among the 4 cases who failed to gain improvement in vision after operation. Effective follow up was achieved in 18 cases, and the follow up period was from two to twenty two years (average six years). Among them, only 3 paticnts showed recurrence of visual disturbance. The results showed that transcranial optic nerve decompression was effective in rescuing vision in fronto orbito sphenoidal fibrous dysplasia with progressive vision loss. Once the patient was near blind before the operation, the surgical result was unsatisfactory.

Objective To study the efficacy and safety of nanometer perfluorocarbon (PFC) in the treatment of hemorrhagic shock, and its role in protecting cerebral cortex nerve cells.Methods Hemorrhagic shock was induced in New Zealand rabbits by arterial bleeding. In the course of the experiment, heart rate, respiratory rate, blood pressure, blood gases, hepatic and renal function, and pathological changes in cerebral cortex were observed. Results The survival rate of animals in the experimental group at 12 hours was higher than that of control group, respiration was deeper and respiratory rate was faster, blood pressure and PaO 2 were significantly higher than that in animals of the control group. There was a tendency of acidosis in the control group. Pupil reflex was more sensitive in the experimental group, and hepatic and renal functions were better in the experimental group than that in control group. Pathological observation showed the cerebral cortex was less damaged in the treatment group than that in control group. Conclusions Nanometer PFC was effective in combating hemorrhagic shock, showing no toxicity to liver and kidney, and it could also be used as an effective neuroprotective agent.

Objective To serially observe carotid arteriosclerosis in rabbit model before and after CEA using high-resolution MRI. Methods Using New Zealand rabbits, lesions were created by air-drying an isolated segment of common carotid artery (120ml/min for 15min) and feeding the rabbits with a diet of 2% cholesterol, 6% peanut oil mixed with normal diet for 2 months. High-resolution MRI examinations were performed for 1 normal rabbit, 4 rabbits with replicated arteriosclerosis before CEA, and 2 rabbits with arteriosclerosis 10 days after CEA, and the results were compared with pathological findings. Results High-resolution MRI revealed the contour and shape of the type II to type IV lesions of rabbit carotid arteriosclerosis model. The MRI images of the lesions corresponded well with the pathological findings. The fibrous plaques were showed as low signals on TOF film, gray images on T 1, T 2, and PDW film, and were obviously enhanced by Gd-DTPA. The MRI images obtained 10 days after CEA also corresponded well with the neo-intima. Conclusion High-resolution MRI can be used as an effective non-invasive method to serially observe the arteriosclerosis lesion of rabbit carotid artery before and after CEA.