BACKGROUND: Recently, several scientists have found that differentiation of neural stem cells (NSCs) towards dopaminergic neurons may be increased in vitro by combination of some special cytokines. They have also found that dopaminergic neurons differentiated from NSCs can be used for the treatment of Parkinsn's disease. To improve the therapeutic effects of/n vitro transplantation, we should further study the biologic characteristics of NSCs at the induction and differentiation.OBJECTIVE: To explore the differentiation of NSCs which were incubated in differentiation solution for different time towards dopaminergic neurons in vitro.DESIGN: Single sample observation.SETTING: Department of Neurosurgery, First Affiliated Hospital of Sun Yat-sen University.MATERIALS: This study was performed at the Department of Ncurosurgery, First Affiliated Hospital of Sun Yat-sen University from May to October 2007. Six healthy Sprague Dawley (SD) rats, gestational age 14 days, of clean grade, weighing 350-400 g,were provided by the Laboratory Animal Center, Sun Yat-sen University[permission No. SCXK (yue)2007-0034]. The protocol was performed in accordance with ethical guidelines for the use and care of animals.METHODS: NSCs derived from rat embryonic mesencephalon were cultured in serum-free culture medium containing epidermal growth factors and basic fibroblast growth factors. After passage, the NSCs were induced to differentiate towards dopaminergic neurons in the differentiation medium supplemented with interleukin 1o, interleukinl 1, human leukaemia inhibitory factors, and glial cell line-derived neurotrophic factors. The percentage of tyrosine hydroxylase positive neurons in differentiated ceils was detected with flow cytometer when NSCs were cultured in differentiation solution for 2, 4, 6, 8 and 10 days, respectively.MAIN OUTCOME MEASURES: Cellular morphological alteration of rat NSCs after differentiation. The percentage of tyrosine hydroxylase positive neurons in differentiated cells derived from NSCs.RESULTS: In differentiation medium, NSC spheres attached the bottom of plates and began to collapse. Cells inside the spheres grew out gradually and became irregular in shape. Six days later, most of the cells had I or 2 long processes and a few short processes. The percentage of tyrosine hydroxylase positive neurons in differentiated cells was respectively (3.2_+_0.9)%, (6.8 +1.6)%, (16.7-+2.6)%, (14.8_+1.8)% and (12.2_+2.5)% after culture for 2, 4, 6, 8 and 10 days, with significant differences (F =26.449, P ＜ 0.05).CONCLUSION: Induction time influences the differentiation of NSCs towards dopaminergic neurons in vitro. The percentage of dopaminergic neurons is the highest in differentiated cells derived from NSCs which are cultured in differentiation solution for 6 days.

Objective To investigate the clinical features and therapeutic strategies of one patient with meningioangiomatosis ( MA ) complicated with intracranial aneurysm formation. Methods The clinical data of one patient with aneurysm-formed MA admitted to the Department of Neurosurgery,the First Affiliated Hospital of Sun Yat-sen University was analyzed retrospectively. The patient received emergency craniotomy and middle cerebral artery aneurysm clipping and evacuation of intracranial hematoma. The meningeal tissue around the aneurysm was taken for pathological examination. Results Microscopy revealed meningeal thickening in the patient with MA accompanied with intracranial aneurysm. Spindle cells around the meninges and perivascular tissue of cortical hyperplasia formed an annular and fence-like structure. The results of immunohistochemistry showed the hyperplastic vessels and perivascular fibroblast like spindle cells diffuse vimentin-positive;the hyperplastic vascular endothelial cells CD99,CD34 were positive;and the residual glial cells in the lesions showed glial fibrillary acidic protein positive. Conclusion MA complicated with intracranial aneurysm is rare. The vascular condition is poor. The shape of aneurysm is irregular,and the risk of bleeding is high. Excise the involved meningeal tissue and clip the aneurysm with microsurgical operation is the resonable treatment.

Objective To undertake animal experimentation and clinical study on the safety and efficacy of percutaneous transluminal angioplasty (PTA) and intraarterial papaverine (IAP) infusion for treatment of refractory symptomatic cerebral vasospasm (CVS). Methods In the experimental study, vasospasm was induced in rabbits by double injections of blood into the cisterna magna, IAP infusion was given on either the 4th day or the 7th day after occurrence of subarachnoid hemorrhage (SAH), and then neurological observation, angiography, light and electron microscopy were done. In the clinical study, since September 1996, 22 patients with refractory symptomatic CVS involving 50 vascular territories received dilation therapy by PTA and IAP within 24 hours of clinical neurological deterioration. Results In the experimental study, all the rabbits except two in the 'the 4th day' group showed angiographic dilation in all of the spastic basilar arteries, and neurological improvement; in the ' the 7th day' group angiographic dilation appeared in 4 (57. 1% ) out of 7 rabbits. After 24 hours, 1 rabbit in each group had recurrence of neurological deficits and angiographic constriction. In the clinical study after aneurysm clipping or endovascular coil embolization was done, within 72 hours of SAH all patients underwent endovascular treatment: PTA alone in 3 cases, IAP alone in 14 cases, PTA and IAP in the remaining 5 cases. All vessel segments were dilated satisfactorily after endovascular treatment. Clinical improvement was significant in 13 cases,moderate in 7, minimal or none in 2; 2 cases died on the 7th day after endovascular dilation treatment. Conclusion Endovascular dilating techniques, namely, PTA, IAP and a combination of PTA and IAP, are safe and effective for treatment of symptomatic CVS refractory to medical therapy.

Objective T0 investigate the effects of transforming growth factorβ1 ( TGFβ1 ) and its receptorβ2 (TGFβR2) gene single nucleotide polymorphisms on the risk of intracranial hemorrhage in patients with brain arteriovenous malformation (BAVM).Methods Fifty-three BAVM patients of both sexes aged 18-64 yr who were genetically unrelated native HAN of Guangdong province were divided into 2 groups:patients with and without intracranial hemorrhage ( n =30:23).Venous blood samples were collected and anti-coagulated with ethylene diaminetetraacetic acid for genomic DNA extraction.TGFβ1-509C/T (rs1800469) and TGFβR2 875A/G (rs3087465) gene SNPs were genotyped by using PCR-RFLP.Results There were no significant differences in genotype and frequency between the 2 groups.The G carrier frequency of the TGFβR2 genotype was significantly higher in patients with intracranial hemorrhage than in patients without intracranial hemonrhage.The G carrier of the TGFβR2 genotype was associated with intrarcranial hemorrhage in patients with BAVM.Conclusion TGFβ1 gene polymorphism is not relevant to the intracranial hemorrhage in patients with BAVM,but polymorphisms of TGFβR2 could be a risk factor.

Objective To investigate the clinical features and treatment strategy of brain arteriovenous malforma-tions(AVM) associated with arterial aneurysms. Methods The clinical manifestation, imaging data, treatment and out-come of the patients with AVM were retrospectively analyzed in 38(10.4%) of these 364 patients. Results Hemorrhage was the most common clinical manifestation (60.5%). The hemorrhage risk was higher in AVM associated with arterial an-eurysms than in single AVM(χ2=5.956,P<0.05). The most common type of associated aneurysms was feeding artery an-eurysm (69.4%). Hemorrhage more frequently occurred within the aneurysm.(χ2=8.869,P<0.05). The bleeding lesions and 43 associated aneurysms of the 37 patients were treated effectively by endovascular treatment and/or craniotomy. Thirty-four patients had excellent or good outcomes, six patients had complications, 3 patients had neurological deficits. Postoperative digital subtraction angiography (DSA) examination showed the complete disappearance of arteriovenous malformation and aneurysm in sixteen cases. Conclusions The AVM associated with aneurysms is common in patients with AVM. AVM associated with aneurysms has a higher risk of hemorrhage than single AVM. The aneurysm within AVM has a higher rate of hemorrhage. The treatment priority should be given to the bleeding lesions and aneurysms.

Objective To evaluate the clinical application of multimodality treatment of brain arteriovenous malformation (BAVM) with Onyx embolization and microsurgery.Methods There were 48 patients with BAVM treated by combination of Onyx embolization and microsurgery.The clinical features,therapeutic process,complications and discharge status (by MRI,DSA and Glasgow outcome scale,GOS) were recorded in detail.The prognosis was estimated by modified Rankin scale (mRS) with 6-42 months' follow-up.Results The total resection rate was 97.9％.The therapy-related complications happened in 8 patients (16.7％).Among them,4 cases had dysfunction of central nervous system (8.3％),2 cases with intra-cerebral hemorrhage (4.2％),and 2 suffered from severe cerebral edema (4.2％).Good recovery was seen in 38 cases (79.2％) evaluated by GOS when discharged from hospital.The follow-up result mRS ＜ 3 was 97.9％.Conclusion Multimodality treatment of BAVM with Onyx embolization and microsurgery should be a good therapeutic strategy.

Objective To observe the variation of cerebral brain flow (CBF)and pathological characteristics in peripheral brain tissue of nidus after operation of brain arterivenous malformations (BAVM) and explore the mechanism and theaputic strategy of normal perfusion pressure breakdown (NPPB)after microsurgery. Methods 12 cases of BAVM that have received surgical resection were analyzed prospectively, and 8 cases of them were embolized with Onyx. The pathological characteristics of the nidus and peripheral brain tissue was observed with microscope and electron microscope. The variation of CBF in peripheral brain tissue of the nidus following microsurgical resection was observed by using Laser Doppuler Perfusion Imaging (LDPI) system. The monitering result of CBF in little meniugioma(n=6) during surgery was used as the control. Results There was small vessel expantion, neuron necrosis, gliocyte hyperplasia and blood brain barriar (BBB) destruction in peripheral brain tissue of BAVM nidus, the visibal brain tissue edema and inflammatory cell infiltration in peripheral brain tissue of the nidus and the revascularization in the emolized nidus vessels were observed after embolization with Onyx. There was significant change of CBF between pre-and post-operation (P<0.05),and after controlling depressurization during surgery was the increasing CBF step down (P<0.05). Conclusion The BBB breakdown and increasing CBF of peripheral brain tissue of the nidus may be the pathological foundation of brain hemorrhage and edema after BAVM microsurgical resection. So embolization before the operation, controlling depressuriation during and after surgery is the important methods for preventing and curing the NPPB of BAVM after microsurgery.

Objective We evaluate if supplementary grading system can refine patient selection and accurately predict neurological outcome in BAVM. Methods We retrospectively study 221 BAVM patients who were treated micro?surgically by our hospital. The score of pre and post operation mRS and relative clinical, radiology data were collected. Two different logistic models (Spetzler-Martin, Supplementary Spetzler-Martin grading model) were constructed to com?pare the area under ROC. Results Some factors are significant different between worse outcome patients and good out?come patients:Non-hemorrhagic presentations prior surgery, AVM bigger than 3cm, diffuse shape of AVM and the elder patients. Predictive accuracy was higher for the supplementary model (ROC area, 0.91), than the Spetzler-Martin model (ROC area, 0.774). So the predictive accuracy of supplementary model was significantly better than that of the Spet?zler-Martin model (P=0.0362). Conclusions Supplementary Spetzler-Martin model can improve preoperative risk pre?diction and subgroup the patients more efficiently. When the score less than 5(including 5) in supplementary Spet?zler-Martin patients seem to have lower risk relative to surgery.

Objective To investigate the microsurgical effect of spinal cord Intramedullary cavernous hemangioma.Methods The clinical data of 23 patients with spinal cord Intramedullary cavernous henangioma from January,2003 to March,2017 were analyzed retrospectively.McCormick clinical neurological function classification method and MRI examination were used to analyze the changes of neurological function and imaging changes beforeand-after operation.MRI and assess nerve function were reviewed 6-12 months after discharge.Results Twentytwo cases were totally resected,and subtotal excised in 1 case.The symptoms improved and even disappeared completely in 17 cases.There was no obvious improvement in 4 cases,2 cases were worse and no death cases.Twentyone cases were followed-up.The follow-up time was 3 months-9 years,and no tumor recurrence was found.Among the 14 cases of clinical neurological function Ⅰ-Ⅱ,10 cases recovered rapidly and most of the symptoms improved or even disappeared.Three cases had no obvious change.The other 1 case aggravated symptoms;Six cases of Ⅲ-Ⅳ patients in 7 cases of postoperative recovery,and 1 case of no change.According to preoperative neurological function grade Ⅰ-Ⅱ and Ⅲ-Ⅳ,the treatment effect of patients was compared,the difference was significant (x2=5.25,P＜0.05).Conclusion Microsurgical resection of spinal cord Intramedullary cavernous hemangioma is safe and effective.The preoperative nerve function,the relationship between the tumor and the spinal cord,and the surgical skill and the degree of resection are the important factors that affect the prognosis.

Objective To investigate the expressions ofstromal-cell derived factor-1α (SDF-1α)and its receptor CXCR4 in brain arteriovenous malformation (AVM) and to explore the relationships of SDF-1α with hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF).Methods Surgical specimens from 48 patients accepted brain AVM resection,collected in our hospital from January 2012 to December 2013,were studied for expressions ofSDF-1α,CXCR4,VEGF and HIF-1α by immunohistochemical staining.The relationships of SDF-1α with VEGF and HIF-1α were analyzed and influences of embolism,hemorrhage and Spetzer-Martin classification in SDF-1α expression were assessed.Results SDF-1α and CXCR4 expressed in 100％ and 83.3％ AVM specimens,respectively.The positive staining for SDF-1α was observed in the cytoplasm of vascular endothelium within the nidus and smooth muscle cells of vascular wall.CXCR4 expressed in vascular endothelium and perivascular cells located in the space between the abnormal vessels.SDF-1α expression was significantly associated with VEGF and HIF-1α (r=0.537 and 0.437,respectively,P＜0.05).SDF-1α showed more intense expression in embolized patients than that in non-embolized patients (P＜ 0.05),while no significant difference was noted between patients with and without hemorrhage and between patients of different Spetzer-Martin classifications (P＞0.05).Conclusion SDF-1α and its receptor CXCR4 highly express in brain AVM; preoperative embolization might induce expression of SDF-1α.