低剂量伽玛刀照射对致(癎)大鼠皮质及海马神经元c-fos和nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致(癎)大鼠大脑皮质及海马神经元c-fos和脑型一氧化氮合酶(nNOS)表达的影响,探讨伽玛刀治疗癫(癎)的作用机制.方法 将44只青霉素致(癎)大鼠模型等分为实验组和实验对照组大鼠各22只,另取4只正常大鼠作为正常对照组.实验组行伽玛刀照射(周边剂量12 Gy)后,应用免疫组化方法,观察大脑皮质及海马神经元c-fos和nNOS表达的变化.结果 无论是皮质还是海马,c-fos和nNOS在实验组与实验对照组动物之间,表达均有明显的差别,实验组表达明显少于实验对照组,而后者呈现双高峰现象.结论 c-fos和nNOS在伽玛刀治疗癫(癎)的机制中发挥了重要作用.     

伽玛刀照射癫痫大鼠海马神经元超微结构及线粒体计量分析

目的观察低剂量伽玛刀照射对癫大鼠海马神经元超微结构的影响。方法建立大鼠青霉素局灶性癫动物模型,将58只SD大鼠分为对照组、癫模型组和伽玛刀照射组。对大鼠行伽玛刀照射,照射中心剂量24 Gy、周边剂量12 Gy、等剂量曲线50%,术后3 h～60 d取靶区海马,透射电镜观察并采用图像分析系统对线粒体形态进行计量分析。结果对照组细胞结构基本正常;癫模型组可见神经元细胞器明显空化,线粒体体密度、数密度、比表面和嵴膜密度较对照组明显减少(均P<0.05),线粒体平均体积和平均截面积较对照组明显增大(均P<0.05)。伽玛刀照射组早期线粒体的平均体积、平均截面积、数密度、比表面与对照组相比差异显著(均P<0.05),中期和晚期线粒体各项参数与对照组相比差异不显著。结论大鼠癫发作早期线粒体形态结构变化明显,低剂量伽玛刀照射对神经元修复起重要作用。     

伽玛刀照射癫大鼠海马神经元超微结构及线粒体计量分析

目的观察低剂量伽玛刀照射对癫大鼠海马神经元超微结构的影响。方法建立大鼠青霉素局灶性癫动物模型,将58只SD大鼠分为对照组、癫模型组和伽玛刀照射组。对大鼠行伽玛刀照射,照射中心剂量24 Gy、周边剂量12 Gy、等剂量曲线50%,术后3 h～60 d取靶区海马,透射电镜观察并采用图像分析系统对线粒体形态进行计量分析。结果对照组细胞结构基本正常;癫模型组可见神经元细胞器明显空化,线粒体体密度、数密度、比表面和嵴膜密度较对照组明显减少(均P<0.05),线粒体平均体积和平均截面积较对照组明显增大(均P<0.05)。伽玛刀照射组早期线粒体的平均体积、平均截面积、数密度、比表面与对照组相比差异显著(均P<0.05),中期和晚期线粒体各项参数与对照组相比差异不显著。结论大鼠癫发作早期线粒体形态结构变化明显,低剂量伽玛刀照射对神经元修复起重要作用。     

低剂量伽玛刀对致痫大鼠皮层及海马神经元Fos表达的影响

目的通过观察低剂量伽玛刀照射对致痫大鼠大脑皮质及海马神经元cfos表达的影响,初步探讨伽玛刀治疗癫痫的作用机制,为临床治疗提供理论依据。方法以青霉素致痫模型为对象,应用免疫组化方法,检测低剂量伽玛刀照射(周边剂量12Gy)后,大脑皮质及海马神经元cfos表达的变化。实验组和对照组大鼠各22只,正常对照组大鼠4只。结果无论是皮层还是海马,伽玛刀照射后cfos在实验组动物和对照组动物中,表达均有明显的差别,并随时间呈现一定的规律性。结论cfos在伽玛刀治疗癫痫的机理中发挥重要作用。     

小剂量伽玛刀照射对致癎大鼠脑神经元nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致痫大鼠大脑皮质及海马神经元nNOS表达的影响，初步探讨伽玛刀治疗癫痫的作用机制。方法 将44只青霉素致痫大鼠模型等分为实验组和实验对照组，对实验组进行伽玛刀照射（周边剂量12Gy），应用免疫组化方法检测两组大脑皮质及海马神经元nNOS表达的变化。结果 nNOS在两组动物的皮质和海马表达均有显著性差别．实验组显著性低于实验对照组；实验对照组表达呈双高峰现象。结论 nNOS在伽玛刀治疗癫痫的机制中具有重要作用。     

伽玛刀低剂量照射对致疒间大鼠海马中氨基酸递质的影响

目的观察伽玛刀低剂量照射对致疒间大鼠海马中谷氨酸(Glu)、γ-氨基丁酸(GABA)的影响,探讨伽玛刀治疗癫疒间的作用机制。方法将50只锂-匹罗卡品致疒间大鼠随机分为照射组和非照射组,各25只,另取正常大鼠25只(腹腔注射生理盐水)作为对照组。照射组大鼠进行伽玛刀低剂量照射(周边剂量20Gy),对照组和非照射组大鼠不进行伽玛刀照射。用高效液相色谱-质谱-质谱(HPLC-MS-MS)分析法检测各组大鼠海马Glu、GABA的含量。结果伽玛刀照射2周后,照射组和非照射组大鼠海马中Glu含量均高于对照组,照射组GLu含量低于非照射组,差异具有统计学意义(P0.05);照射组和非照射组GABA含量均低于对照组,照射组GABA含量高于非照射组,差异具有统计学意义(P0.05)。结论伽玛刀低剂量照射通过调节海马中Glu与GABA的平衡,以达到抗癫疒间的作用。     

低剂量伽玛刀照射对致大鼠皮质及海马神经元c-fos和nNOS表达的影响

目的 通过观察低剂量伽玛刀照射对致痫大鼠大脑皮质及海马神经元c—fos和脑型一氧化氮合酶（nNOS）表达的影响，探讨伽玛刀治疗癫痫的作用机制。方法将44只青霉素致痫大鼠模型等分为实验组和实验对照组大鼠各22只，另取4只正常大鼠作为正常对照组。实验组行伽玛刀照射（周边剂量12Gy）后，应用免疫组化方法，观察大脑皮质及海马神经元c-fos和nNOS表达的变化。结果无论是皮质还是海马，c—fos和nNOS在实验组与实验对照组动物之间，表达均有明显的差别，实验组表达明显少于实验对照组，而后者呈现双高峰现象。结论c—fos和nNOS在伽玛刀治疗癫痫的机制中发挥了重要作用。     

氟桂利嗪对青霉素致痈效应和海马神经元单位放电的影响

目的：探讨Ca^2＋拮抗剂氟桂利嗪对青霉素致效应和海马神经元单位放电的影响.方法：Wistar大鼠随机分成3组.正常对照组;癫癎模型组：用青霉素钠按6 000 000 U·kg^-1腹腔注射;癫癎预处理组：造模前用盐酸氟桂利嗪 20 mg·kg^-1每隔12 h灌胃,共2次,于第2次给药2 h后制作模型.观察癫癎发作并记录海马神经元单位放电.结果： ①正常对照组大鼠共记录到24个单位海马神经元放电;②癫癎模型组共记录到78个单位海马神经元放电,癫癎发作程度强,发作频率高;③癫癎预处理组共记录到47个单位海马神经元放电,癫癎发作程度减轻,发作频率减少.结论：氟桂利嗪可抑制青霉素致效应,减少海马神经元的单位放电.     

伽玛刀对大鼠海马体内体外放射生物学作用

目的 探讨伽玛刀照射对大鼠海马组织与培养的海马神经元放射生物学作用的差异.方法 分别对大鼠海马组织和堵养的海马神经元进行伽玛刀照射,观察照射前后组织超微结构变化、FOS和HSP70表达以及细胞存活情况.结果 在体海马组织和培养的海马神经元对放射反应不同.高剂量(150和100Gy)引起在体海马组织严重损伤,60Gy引起轻度损伤,而低剂量(30Gy)即可引起培养的海马神经损伤和死亡.大鼠海马组织和培养的海马神经元的FOS和HSP70表达与照射强度和照射后时间有关.结论 海马组织和培养的海马神经细胞的损伤程度都与伽玛刀的照射强度存在明显的剂量-效应关系和时间-效应关系,但两者对伽玛射线的反应存在一定差异.     

喹啉对癫(癎)大鼠海马神经元连接蛋白36表达的影响

目的:探讨喹啉对癫癎大鼠海马神经元连接蛋白36(Cx36)表达的影响.方法:64只SD大鼠随机分为正常对照组、癫癎模型组、地西洋治疗组和喹治疗组,每组16只大鼠.采用氯化锂-匹罗卡品诱导制作癫癎大鼠模型,地西泮治疗组子以1mg/kg地西泮治疗,喹啉治疗组予以60mg/kg喹啉治疗.术后分别采用Racine评分和脑电图检查判断癫癎发作情况.分别用免疫荧光染色法、Western blot法检测各组大鼠术后2h、4h时海马神经元Cx36的表达.结果:与正常对照组比较,癫癎模型组和地西泮治疗组大鼠术后2h、4h时海马神经元Cx36表达水平显著升高(均P<0.01).癫癎模型组和地西泮治疗组大鼠术后2h、4h时海马神经元Cx36表达水平比较差异无统计学意义.与癫癎模型组及地西泮治疗组比较,喹啉治疗组大鼠术后2h、4h时海马神经元Cx36表达水平显著降低(均P<0.01).结论:癫癎大鼠海马神经元Cx36表达水平升高,喹啉能抑制这一变化.     

RNA干涉Ku70基因增敏伽玛刀治疗大鼠C6脑胶质瘤的实验研究

目的研究RNA干涉Ku70（Ad-Ku70shRNA）联合伽玛刀治疗对大鼠C6胶质瘤的生长抑制作用。方法将SD大鼠分为5组（每组12只）：对照组、Ad-Ku70shRNA组、空载病毒组、伽玛刀治疗组、Ad-Ku70shRNA联合伽玛刀治疗组（联合治疗组）。分别建立大鼠胶质瘤模型模型。建立第10天,对伽玛刀治疗组及联合治疗组大鼠进行伽玛刀治疗,边缘剂量15Gy,治疗后48h,每组处死2只大鼠,行生物学特性检测（增殖、侵袭、凋亡等）;其余10只在伽玛刀治疗后1、2、4及8周进行MRI检查,并观察生存期及生存状态。结果伽玛刀治疗组及联合治疗组与其他三组比较,大鼠肿瘤细胞出现明显的增殖抑制、侵袭性减弱、凋亡率增高,生存期显著延长;联合治疗较单纯伽玛刀的治疗作用明显增强。结论伽玛刀联合Ad-Ku70shRNA治疗C6荷瘤大鼠,较单纯伽玛刀治疗具有更好的肿瘤细胞抑制作用,可使荷瘤动物生存期明显延长。     

PET/CT定位伽玛刀治疗顽固性癫痫的临床研究

目的评价PET/CT定位伽玛刀治疗难治性癫痫的疗效。方法对2007年1月至2010年12月来我院就诊的难治性癫痫患者进行PET/CT检查,30例患者接受了伽玛刀治疗,均以50%等剂量曲线包绕病灶,周边剂量为9～13Gy。根据PET/CT显示的致痫灶的代谢分为低代谢组(A组)和高代谢组(B组,包括高低病灶并存);低代谢组根据PET/CT显示的致痫灶的数量分为单病灶组(A1)和多病灶组(A2)。结果随访12～48个月,30例患者PET显像均表现异常,低代谢灶20例,高代谢灶8例,低代谢灶和高代谢灶共存2例。低代谢组中单病灶14例,多病灶6例。A和B组癫痫发作频率较治疗前明显降低,且B组疗效明显高于A组。A1组和A2组癫痫发作频率较治疗前明显降低,且A1组疗效明显高于A2组。所有治疗病例均未发生明显并发症。结论 PET/CT定位伽玛刀治疗难治性癫痫具有较高的有效率。高代谢组疗、单一病灶组疗效优于低代谢组、多病灶组。     

Gamma knife treatment of rat glioma——Influences of irradiation dose on apoptosis and necrosis

BACKGROUND： Apoptosis and necrosis are cellular death mechanisms that are induced in glioma cells following gamma knife irradiation. Increased apoptosis is essential for maintaining and enhancing treatment efficacy. OBJECTIVE： To observe apoptotic and necrotic mechanisms of rat glioma models induced by gamma knife treatment and to analyze the influences of irradiation doses on apoptosis and necrosis. DESIGN： Controlled animal experiment. SETTING： Cancer Hospital of Tianjin Medical University and Gamma Knife Center of Hefei Brain Hospital. MATERIALS： Eighteen female specific pathogen free Sprague Dawley rats, weighing 180 210 g and 5 6 weeks old, were purchased from the Experimental Animal Center, Medical College of Suzhou University. Rat C6 glioma cells were purchased from the cell bank of Chinese Academy of Sciences. Annexin V-FITC Reagent Kit （Bender Med System. Company, USA） and a flow cytometer （Becton Dickinson FACSCalibur） were provided. METHODS： The experiment was conducted at the Cancer Hospital of Tianjin Medical University and Gamma Knife Center of Hefei Brain Hospital from December 2006 to May 2007. All rats were inoculated with C6 glioma cells, i.e., 4 μL of a C6 glioma cell suspension was injected 5 mm deep in the cortex. All rats were divided randomly into a model group, 9-Gy treatment group, and 12-Gy treatment group. There were six rats in each group. MAIN OUTCOME MEASURES： Apoptosis and necrosis of normal brain tissue and glioma were observed by Flow Cytometry one week after irradiation, and pathological changes to tumor tissue were identified by HE staining. RESULTS： Eighteen rats were initially selected for the study： two rats from the model and 12-Gy treatment groups died from accidental anesthesia. The remaining 16 rats were included in the final result analysis. Cellular apoptosis and necrosis： apoptosis and necrosis were significantly increased in the treatment groups after gamma knife irradiation, compared to the model group （P 〈 0.05）. Apoptosis was grea     

Ultrastructural changes of rat cortical neurons following ligustrazine intervention for cerebral ischemia/reperfusion injury

BACKGROUND: Ligustrazine can reduce the production of free radicals and the content of malonaldehyde, and improve the enzymatic activity of adenosine-triphosphate in cerebral anoxia. It also can increase the expression of heat shock protein-70 and Bcl-2, thus alleviating brain tissue injury caused by cerebral ischemia/reperfusion. This study aimed to address the question of whether ligustrazine can protect the membrane structure of neurons.OBJECTIVE: To establish rat models of cerebral ischemia/reperfusion, observe the membrane structure and main organelles of neurons with electron microscope after ligustrazine intervention, and to analyze the dose-dependent effects of ligustrazine on neuronal changes.DESIGN: Arandomized controlled study.SETTING: Department of Anatomy Research and Electron Microscopy, Hebei North University. MATERIALS: Forty Wistar rats of SPS grade, weighing 180–250 g and equal proportion of female and male, were provided by Hebei Medical University Animal Center (No. 060126). The ligustrazine injection (40 g/L, No. 05012) was produced by Beijing Yongkang Yaoye. LKB4 Ultramicrotome was purchased from LKB Company in Sweden. JEM100CXII electron microscope was purchased from JEOL in Japan.METHODS: The experiment was performed in the Laboratory of the Department of Anatomy and Electron Microscopy, Hebei North University from June to August 2006. ① Wistar rats were allowed to adapt for 3 days, and were then randomly divided into four groups, according to the numeration table method: normal group, model group, low-dose ligustrazine group, and high-dose ligustrazine group. There were 10 rats in each group. ②Rats in the model group, low-dose ligustrazine group, and high-dose ligustrazine group un-derwent cerebral ischemia/reperfusion model, according to Bannister's method. The carotid artery was opened for reperfusion after 90 minutes of cerebral ischemia. Samples were collected from the cerebral cor-tex after 24 hours. Animals from the ligustrazine low-dose group and ligustrazine high-dose group received ligustrazine injections, 50 mg/kg and 100 mg/kg, respectively. Samples were collected at the same time as the model group.MAIN OUTCOME MEASURES: Alterations of the neuronal ultrastructure and main organelles were ob-served by electron microscopy.RESULTS: Forty Wistar rats were included in the final analysis. Plentiful ribosome and rough endoplasmic reticulum existed in the cytoplasm of cortical neurons in the normal group. Edema existed in the nucleus and cytoplasm of neurons in the model group. The cell membrane was damaged, resulting in the external erup-tion of certain cellular organelles. In the low-dose ligustrazine group, neuronal swelling was decreased in the cytoplasm, whereas cellular organelles were relatively increased. However, the mitochondria remained swollen. The double layer structure disappeared in parts of the mitochondrial membrane. The caryotheca was still broken, and neuronal damage was significantly decreased in the high-dose ligustrazine group. In ad-dition, cytoplasmic swelling was reduced andmost part of caryotheca was complete. Fragmentation of the cellular membrane was not detected. Mitochondrial cristae and the lysosome could also be detected. The number of rough endoplasmic reticulum and free ribosomes was increased, and the structure of great part of caryotheca was clear. In addition, the number of nuclear pore was increased. However, the nuclear hetero-chromatin was relatively reduced.CONCLUSION: In the rat, the protective effects of ligustrazine were significant on neuronal membrane structures and main organelles after cerebral ischemia/reperfusion. There was a dose-dependent effect be-tween neuronal changes and Ligustrazine.     

Neurobiological responses to stereotactic focal irradiation of the adult rodent hippocampus

Radiation effectively treats brain tumors and other pathologies but dose and treatment plans are limited by normal tissue injury, a major cause of morbidity in survivors. Clinically significant normal tissue injury can occur even with therapies that target pathological tissue and limit out-of-target irradiation. Elucidating the mechanisms underlying normal tissue injury is facilitated by studying the effects of focal irradiation and comparing irradiated and un-irradiated tissue in experimental animals. Young adult rats were irradiated using the Leksell Gamma Knife? with a 10 Gy maximum dose directed at the left hippocampus and shaped to minimize irradiation contralaterally. At least 95% of targeted hippocampus received ≥3 Gy, while all points in the contralateral hippocampus received <0.3 Gy. Neuronal and microglial markers of damage were assessed in the targeted and contralateral hemispheres of Gamma Knife?-treated rats and compared to non-irradiated controls. Acute cell death and sustained changes in neurogenesis and in microglia occurred in the dentate gyrus of the targeted, but not the contralateral, hippocampus, providing experimental evidence that focal irradiation at doses received by peri-target regions during targeted radiation therapy produces robust normal tissue responses. Additional studies using this approach will facilitate assessment of in vivo dose responses and the cellular and molecular mechanisms of radiation-induced brain injury.