茎突CT薄层冠状扫描在诊断茎突过长综合征中的价值

目的 探讨“一点一线垂直法”茎突CT薄层冠状扫描在诊断茎突过长中的价值。方法测量72例双侧茎突的长度、方位、形态、厚度、尖端与咽侧壁距离,总结茎突过长病人的临床症状与诊断。 结果 ①41例67侧长度超过3.0cm,符合茎突过长的诊断;②12例12侧茎突虽未超过3.0cm(均在2.5～2.9cm),且茎突方位角>20°、末端与咽侧壁的距离<20mm,并有临床症状的应考虑茎突过长综合征;③按茎突的形态进行分型:锥型(分直锥、弧锥),束状型,分节型,发育不良型。其中分节型与临床症状有密切关系。结论 ①茎突CT薄层冠状扫描能清晰显示茎突的长度、形态、厚度、末端与咽侧壁距离,是诊断茎突过长的一种可靠方法;②“一点一线垂直法”茎突CT薄层冠状扫描无需进行图像重建,可操作性强、简捷易行、便于推广。     

多层CT作肺血管分期造影对肺癌侵犯中央肺动脉的评估

目的 探索多层螺旋CT作肺血管分期造影的可能性和评价肺癌侵犯中央肺动脉的临床价值。方法 用多层螺旋CT对73例肺门区肺癌患者进行研究。分两段对比剂注射，结合三个扫描程序作肺血管分期造影，根据肺动脉被侵犯的不同部位和程度分为三度。按盲法评价图像并与手术和病理对照。结果 肺动脉分期造影成功的共68例(93.15％，68/73)。肺动脉I度侵犯者4例(5．88％，4／68)，Ⅱ度侵犯者9例(13．23％，9/68)，Ⅲ度侵犯者55例(80．88％，55/68)。I度者全部作肺叶切除;Ⅱ度与Ⅲ度者的肺叶切除率有显著性差异(x^2＝64．03，P＜0.005)；Ⅲa度与Ⅲb度者的肺叶切除率也有显著性差异(x^2＝68．69，P＜0.005)，Ⅲc度全部放弃手术。结论 多层螺旋CT作肺血管分期造影能更好地显示肺癌侵犯中央肺动脉的部位和程度，为选择外科治疗方案提供更多的影像学依据。     

调心方活性部位对大鼠海马脑片CA1区诱发LTP的影响

目的：研究调心方活性部位A对大鼠海马脑片诱发长时程增强(LTP)效应的影响。方法：采用细胞外微电极记录技术，记录大鼠海马脑片CA1区诱发群峰电位(PS)，然后施以100Hz，100串的强直刺激诱发LTP。结果：调心方活性部位A对大鼠海马脑片正常PS的形状、幅度无影响，提示并不影响海马的基础突触传递。给予强直刺激后，高浓度活性部位A可以明显增大LTP幅度，提示具有促进和维持LTP的作用。结论：调心方活性部位A可能是调心方促进和维持大鼠海马脑片诱发LTP的有效成分之一，对LTP的促进作用也是调心方活性部位A益智作用的机制之一。     

Transient depression of excitatory synaptic transmission induced by adenosine uptake inhibition in rat hippocampal slices

The transient property of the dipyridamole-induced depression of excitatory synaptic transmission was analyzed using field EPSPs (fEPSPs) recorded from the CA1 region in rat hippocampal slices. The fEPSPs were depressed by 1 microM dipyridamole and then gradually recovered to the control level. The depression was antagonized by aminophylline or DPCPX, although it was not significantly affected by DMPX. The results suggest that the fEPSP depression is induced by a mechanism through the A(1) receptor.     

Influence of the ventral hippocampal formation on plasma vasopressin, hypothalamic-pituitary-adrenal axis, and behavioral responses to novel acoustic stress

The ventral hippocampal formation (vHF) seems to constrain diverse responses to psychological stimuli, and disruption of this function may underlie severe neuropsychiatric diseases. In particular, the ventral subiculum inhibits hypothalamic-pituitary-adrenal axis (HPA) activity following psychological, but not systemic, stressors. Despite the difficulty in interpreting such HPA responses, they have been relied upon to further characterize vHF function, because increased HPA axis activity is implicated in neuropsychiatric disturbances, and reliance on behavioral and cognitive data is even more problematic. Plasma arginine vasopressin (pAVP), which is inhibited by psychological stimuli and is also implicated in diverse neuropsychiatric diseases, provides a less ambiguous measure of CNS function. To test if its inhibition by psychological stress is also mediated by the vHF, we conducted two studies. In the first, pAVP and behavioral responses to novel acoustic stress were assessed in rats with bilateral excitotoxic lesions of the ventral subiculum and the ventral hippocampus. The subiculum lesions blocked the fall in pAVP and enhanced escape behaviors, whereas the hippocampal lesions produced responses intermediate to those in the subiculum-lesioned and control rats. In the second study, the pAVP response was similarly blocked by small lesions restricted to those vHF subfields which project to the neuroendocrine hypothalamus, compared to the response in animals with lesions in other vHF subfields. These results indicate that discrete projections from the vHF inhibit the pAVP response to psychological stimuli, and suggest that pAVP may provide a reliable probe of vHF activity.     

Involvement of calmodulin-dependent protein kinase II in carbachol-induced rhythmic activity in the hippocampus of the rat

The role of calcium and protein kinases in rhythmic activity induced by muscarinic receptor activation in the CA1 area in rat hippocampal slices was investigated. Extracellular recording showed that carbachol (20 microM) induced synchronized field potential activity with a dominant frequency of 7.39+/-0.68 Hz. Pretreatment with the membrane permeable Ca(2+) chelator BAPTA-AM (50 microM) or with thapsigargin (1 microM), a compound which depletes intracellular calcium stores, reduced the dominant power of carbachol-induced theta-like activity by 83% and 78%, respectively. Inhibition of calmodulin-dependent protein kinase II (CaMKII) by the cell permeable inhibitor KN-93 (10 microM) reduced the power of carbachol-induced theta-like activity by 80%. In contrast the protein kinase C (PKC) inhibitor calphostin C did not significantly (P>0.05) affect the effect of carbachol. Whole-cell recording indicated that KN-93 also blocked carbachol-induced suppression of slow I(AHP) and strongly inhibited the carbachol-induced plateau potential. Our data suggest that activation of CaMKII by carbachol is crucial for local theta-like activity in the CA1 area of the rat hippocampus in vitro. Furthermore, involvement of CaMKII in carbachol-induced suppression of the slow I(AHP) and the induction of plateau potentials could play a role in the induction of theta-like rhythmic activity by carbachol.     

铅对小鼠海马[Ca2+]的影响及L型钙通道的作用

目的　探讨铅对分离的小鼠海马细胞内游离钙的影响及其及L型钙通道的作用。方法　采用低浓度胰蛋白酶消化法分离小鼠海马细胞 ,并以莹光指标剂 (Fura 2 )作Ca2 荧光探针 ,用双波长荧光法测定海马细胞 [Ca2 ] i。结果　铅可致分离的小鼠海马细胞 [Ca2 ] i 升高 [由静息时的 (2 0 3 4± 10 86)nmol L升至 (4 2 3 3± 19 2 6)nmol L] ,而不论胞外是否有钙 ;铅可抑制钾诱发海马细胞 [Ca2 ] i 升高 ,尼莫地平可加强这种抑制作用 ,而BayK864 4则可部分消除这种抑制作用。结论　铅可致分离的小鼠海马细胞 [Ca2 ] i 升高作用与胞内钙库释放有关 ;铅的抑制钾诱发海马细胞 [Ca2 ] i 升高作用与其抑制L型钙通道有关。     

保存时距对短期记忆之记忆量的影响

目的:通过对大学生短期记忆之记忆量的测定,探讨保存时距对短期记忆的记忆量的影响。方法:以学习材料(每组20个汉字,共5组)、电脑、大学生为研究对象(42名北大医学部2003级学员参加实验),实验中包括1 s立即回忆,2 s立即回忆,1 s延迟回忆,2 s延迟回忆4种不同的测验方式,并随机分配给42名参加实验的学员进行测量。结果:进行F检验作保存时距与短期记忆保留量之间的分析得到,在短期记忆中,时距的长短对记忆量的影响很大,而在长期记忆中,时距的长短对记忆量的影响不大;当保存时距较长时,延迟作用比较明显,而当保存时距较短时,延迟作用并不明显。     

肺动脉栓塞多排螺旋CTA血管成像

目的探讨肺动脉栓塞多排螺旋CTA血管成像扫描延迟时间的最佳值，最佳肺动脉血管成像。方法收集了45例肺动脉栓塞多排螺旋CTA血管成像，造影剂用量按1．5ml／kg，注射速率3ml／sec。扫描延迟时间用Bolus Tracking第一组20例；test Bolus为二组15例；常规计算时间为一组10例。准直器宽度2．5mm，层厚3mm。数据重建用最大密度投影（MIP）和容积显示（VR3D）等常规方法。一、二、三组图像分别由两位高年资医师阅片。结果第一组20例中19例和第二组15例图像肺动脉均清晰显示。第三组10例中4例图像模糊，第三组与第一、二组图像质量有显著差异。结论肺动脉栓塞CTA血管造影中扫描延迟时间用Test Bolus和Bolus Tracking较优，常规计算时间延迟图像质量较差。     

促红细胞生成素对脑缺氧的保护作用

 目的在细胞水平探讨促红细胞生成素(EPO)对缺氧诱发的神经元损伤的改善作用及缺糖缺氧诱发的脑片损伤的改善作用。方法　采用原代新生大鼠皮层培养和小鼠脑片的方法,分别以形态学和二苯基四氮唑溴盐(MTT)及2,3,5-三苯基氯化四氮唑(TTC)染色为指标观察神经元及脑片的损伤和药物的改善作用。结果EPO在10^-11,10^-12mol·L^-1能显著改善缺氧24 h引起的培养神经元死亡,其在10^-9mol·L^-1能改善缺氧45min或缺糖缺氧15min引起的脑片梗死。结论EPO对缺氧诱发的神经元死亡和缺糖缺氧诱发的脑片梗死具有保护作用。