陡脉冲电场对荷瘤BALB/c小鼠癌细胞杀伤效应的实验研究

观测陡脉冲电场对荷瘤BALB/c小鼠癌细胞的杀伤效应。处理后的癌细胞在光镜下表现为细胞核固缩、核碎裂、核溶解;在电镜下表现为异染色质增加,边集,呈团块样改变,细胞质肿胀,脂滴数量增加,质膜破裂;核固缩,碎裂,线粒体肿胀。实验揭示了陡脉冲电场能有效地杀伤癌细胞,明显抑制了荷瘤小鼠恶性肿瘤的生长、增殖,有着良好的应用前景。     

骶后孔(八髎穴)的临床应用解剖学

目的 :为八穴的针灸推拿以及骶后神经和骶管麻醉提供解剖学依据。方法 :我们测量了 30例骶骨标本 ,将骶后中线定为Y轴 ,将通过两骶角的连线定为X轴 ,测定骶后孔中点至两轴的距离 ;并测量骶后孔的口径 ,骶后孔中点至相应骶前孔中点的间距以及每侧 1～ 2 ,3～ 4骶后孔中点间距。结果 :根据统计分析 ,我们确定了两种骶后孔定位方法 ,取得了 1～ 2 ,3～ 4骶后孔中点间距的数值 ;4对骶后孔口径的大小顺序是 :1孔 >2孔 >4孔 >3孔。结论 :两种定位方法可帮助医生对骶后孔进行更为准确的定位 ,避免一些给患者带来的损伤 ,可使一些医疗麻醉等措施得以成功实施 ,有助于提高临床疗效     

激活AMPA受体抑制大鼠骶髓后连合核神经元NMDA反应──制霉菌素穿孔法膜片钳研究

在急性分离的大鼠骶髓后连合核神经元上，采用制霉菌素穿孔法膜片钳技术，研究ＡＭＰＡ受体和ＮＭＤＡ受体的相互作用．结果显示，激活ＡＭＰＡ受体可逆性地抑制ＮＭＤＡ反应，该效应依赖于细胞外钙离子．而且，通过ＡＭＰＡ受体通道内流的钙离子单独即足以抑制ＮＭＤＡ受体介导的反应．本结果证明，钙离子可透性ＡＭＰＡ受体可能参与了脊髓伤害性信息的调控．该过程可能与针刺镇痛的机制有关．     

Acceleration of peripheral nerve regeneration after crush injury in rat

It the sciatic nerve of a rat is crushed in the thigh, axons from the proximal side of the crush will regenerate so that the toe-spreading reflex becomes observable again after 10.4 +/- 1.7 (mean +/- S.D.) days. If the nerve is electrically stimulated for 0.25-1.0 h at the crush site, just after the crush occurs, the toe-spreading reflex first becomes observable 4.14 +/- 1.6 (mean +/- S.D.) days after the crush. Stimulation is most effective if delivered immediately after the crush but can be delayed up to an hour and still cause significantly faster regeneration. This phenomenon could be useful in clinical management of crushed peripheral nerves.     

核素显像评价电刺激对健康青年人小肠运动功能影响的试验研究

目的利用放射性核素显像研究十二指肠电刺激对人小肠通过时间的影响。方法12例健康青年志愿者,男女各6例,年龄21～25岁,中位年龄23岁。在胃镜引导下留置导管至十二指肠水平部,并安置电极,将99mTc-DTPA(二乙撑三胺五乙酸)和乳果糖混合液注入导管,用单光子发射式计算机断层仪(SPECT)进行连续小肠显像。择日对受试者进行电刺激,刺激条件:频率13Hz、波宽300ms、刺激强度5mA的方波,采用上述方法进行显像。使用感兴趣区分析法,生成小肠时间-放射性曲线,计算出小肠半排时间(T50),比较刺激前后小肠半排时间的变化。结果电刺激前后小肠平均半排时间分别为(49.5±15.8)min和(29.6±10.9)min,刺激前后T50变化有统计学意义(P<0.01)。结论放射性核素显像能很好地反映小肠运动变化,十二指肠电刺激能明显加快小肠运动。     

How is electrical stimulation of the brain experienced,and how can we tell? Selected considerations on sensorimotor function and speech

ABSTRACT

Electrical stimulation of the nervous system is a powerful tool for localizing and examining the function of numerous brain regions. Delivered to certain regions of the cerebral cortex, electrical stimulation can evoke a variety of first-order effects, including observable movements or an urge to move, or somatosensory, visual, or auditory percepts. In still other regions the subject may be oblivious to the stimulation. Often overlooked, however, is whether the subject is aware of the stimulation, and if so, how the stimulation is experienced by the subject. In this review of how electrical stimulation has been used to study selected aspects of sensorimotor and language function, we raise questions that future studies might address concerning the subjects’ second-order experiences of intention and agency regarding evoked movements, of the naturalness of evoked sensory percepts, and of other qualia that might be evoked in the absence of an overt first-order experience.     

Near-infrared spectrophotometry determined brain oxygenation during fainting

During orthostatic hypotension we evaluated whether presyncopal symptoms relate to a reduced brain oxygenation. Nine subjects performed 50° head-up tilt for 1 h and eight subjects were followed during 2 h of supine rest and during 1 h of 10° head-down tilt. Cerebral perfusion was assessed by transcranial Doppler determined middle cerebral artery blood velocity (MCA v_mean), while brain blood oxygenation was assessed by near-infrared spectrophotometry determined concentration changes for oxygenated (ΔHbO₂) and deoxygenated haemoglobin and brain cell oxygenation by the oxidized cytochrome c concentration (ΔCytO₂). During head-up tilt, six volunteers developed presyncopal symptoms and mean arterial pressure (88 (78–103) to 68 (57–79) mmHg; median and range), heart rate (96 (72–111) to 65 (50–107) beats min^?1), MCA v_mean (59 (51–82) to 41 (29–56) cm s^?1), ΔHbO₂ (by ?5.3 (?3.0 to ?14.8) μmol l^?1) and ΔCytO₂ were reduced (by ?0.2 (?0.1 to ?0.4) μmol l^?1; P < 0.05). During tilt down the cardiovascular variables recovered immediately and ΔHbO₂ increased to 2.2 (?0.9–12.0) mmol L^?1 above the resting value and also ΔCytO₂ recovered. In the nonsyncopal head-up tilted subjects as in the controls, blood pressure, heart rate, MCA v_mean and brain oxygenation indices remained stable. The results suggest that during orthostasis, presyncopal symptoms relate not only to cerebral hypoperfusion but also to reduced brain oxygenation.