Effect of the free radical scavenger MCI-186 on spinal cord reperfusion after transient ischemia in the rabbit

Objective: Paraplegia remains a serious complication of aortic operations. The production of free radicals during reperfusion after transient ischemia is believed to induce secondary spinal neuronal injury, resulting in paraplegia. The aim of the present study was to clarify the protective effect and method of administration of antioxidants on the neurological and histological outcome in the animal model for reperfusion injury after transient spinal cord ischemia. Methods: New Zealand white rabbits underwent surgical exposure of the abdominal aorta that was clamped for 15 minutes to achieve spinal cord ischemia. Group A animals received two 10 mg/kg doses of 3-methyl-l-phenyl-2-pyrazolin-5-one (MCI-186) at the time of release of the aortic clamp and 30 minutes later. In group B, MCI-186, 5 mg/kg, was given three times, at the time of aorta clamp release, 30 minutes and 12 hours later. In group C (control group), one dose of vehicle was administered. Neurological status was assessed using modified Tarlov’s score until 168 hours after operation. Spinal cord sections were examined microscopically to determine the extent of ischemic neuronal damage. Results: Groups A and B animals had better neurological function than group C (p(0.001). In contrast, group C animals exhibited paraplegia or paraparesis with marked neuronal necrosis. The number of surviving neurons within examined sections of the spinal cord was significantly greater in group B than in group C (p(0.001). Conclusion: In a 15-minute ischemia-reperfusion model using rabbits, systemic repetitious administration of MCI-186, a free radical scavenger, was found to have a protective effect on the spinal cord neurons both neurologically and histologically. We postulate that the drug minimizes the delayed neuronal cell death for reperfusion injury after transient ischemia by reducing the free radical molecules. Moreover, it was thought that we could protect delayed neuronal cell death more effectively by administering MCI-18612 hours later.     

Mechanisms mediating the brain stem control of somatosensory transmission in the dorsal horn of the cat's spinal cord: an intracellular analysis

Summary The effect of brainstem stimulation was studied on neurones recorded intracellularly in the superficial and deeper laminae of the lumbosacral dorsal horn of the spinal cord in anaesthetised cats. Stimulation in the nucleus locus coeruleus (LC) produced a hyperpolarisation in 4/13 multireceptive neurones and produced a biphasic action consisting of a hyperpolarisation which was followed by a depolarisation in 3/13 neurones. These actions were produced irrespective of whether the multireceptive neurone was located in the superficial or deeper laminae of the dorsal horn. Stimulation failed to produce postsynaptic potentials in the remaining 6/13 multireceptive neurones. The amplitude of hyperpolarisation was increased by the passage of depolarising pulses through the recording microelectrode and decreased by hyperpolarising pulses. Stimulation in other brainstem areas such as, the lateral (FTL), paralemniscal (FTP) and central (FTC) divisions of the tegmental field and the nuclei raphe magnus (NRM) and reticularis magnocellularis (RMc) also hyperpolarised neurones in the dorsal horn. The polarity of hyperpolarisation evoked from some brainstem areas (FTP, FTC, RMc) could be reversed to depolarisation by the passive diffusion of ions from the recording microelectrode containing 3M-KCl. Brainstem (LC, NRM, FTP, FTL) stimulation generated long lasting (700 ms) hyperpolarisation on 4/4 selectively nocireceptive neurones of lamina I. There was, however, no effect on the activity of 5/5 neurones recorded in laminae I/II which in addition to receiving excitatory cutaneous inputs were inhibited by heat stimuli. Stimulation in LC also produced dorsal root potentials (DRPs) and reduced the amplitude of simultaneously recorded excitatory postsynaptic potentials (EPSPs) generated by the activation of primary afferent fibres in 3 multireceptive neurones. It is concluded that inhibition of nociceptive transmission in the spinal cord from LC and other brainstem areas may involve both pre- and postsynaptic mechanisms.     

电针对SNI大鼠痛敏及脊髓相应节段谷氨酸和P物质的影响

目的:探讨电针对神经病理性痛大鼠痛觉过敏以及脊髓谷氨酸和P物质含量的影响。方法:40只SD大鼠,随机分为空白组、假手术组、手术组和电针组(n=10)。采用坐骨神经分支选择性损伤模型,电针"委中"和"环跳"穴,观察其对大鼠机械痛阈和热痛阈的影响,以OPA柱前衍生+HPLC荧光检测和放射免疫分析法测定脊髓相应节段谷氨酸和P物质含量的变化。结果:SNI手术可明显降低大鼠机械痛阈,并且其脊髓相应节段谷氨酸含量明显升高,P物质含量则明显降低;而电针干预后可显著降低大鼠脊髓相应节段谷氨酸的含量,升高P物质含量,并减轻SNI大鼠的机械痛敏状态,进而改善其痛行为。结论:电针干预神经病理性痛的脊髓机制之一可能与其有效的减少大鼠脊髓相应节段谷氨酸和P物质的释放有关。     

同时应用融合和非融合技术治疗创伤性腰椎间盘损伤(附4例临床病例报道及文献复习)

目的观察同时应用融合及非融合技术治疗腰椎间盘损伤的远期疗效,对照该术式与非手术治疗的远期疗效。方法对4例由于急性外伤引起的L4/L5及L5/S1椎间盘损伤患者进行影像学评价。根据生物力学稳定性对病变节段分别采用融合和非融合技术。手术全部经前路腹膜外切口。L5/S1采用椎间融合(自体髂骨 cage植入),L4/L5采用人工椎间盘植入。术后随访4年,摄术后X线正侧位、动力位片,术后2年MRI检查,SF36问卷调查。同期8例患者采用非手术治疗作为对照。结果术后6、12、24、36及48个月X线片显示,融合节段正侧位椎体间无移位,全部患者均有明显的骨性融合。非融合节段人工椎间盘假体位置良好,术后2年MRI显示有正常活动。同期8例非手术治疗患者5例缓解,3例因症状加重实施手术。结论前路融合技术可以有效稳定椎节,缓解腰椎不稳所致的疼痛。人工腰椎间盘植入可以有效地维持放射学稳定性,但不能完全替代正常椎间盘的功能。     

Prenatal diagnosis of Werdnig Hoffmann disease in China

Objective To establish a means for prenatal prediction of spinal muscular atrophy (SMA) through survival motor neuron (SMN) gene deletion analysis and genetic counseling in families with a child affected with SMA.
Methods Genetic analysis for prenatal prediction of Werdnig-Hoffmann disease was performed in a at risk Chinese family by polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) in SMN gene exons 7 and 8.
Results The pregnancy was positive for the homozygous deletion of the SMN gene, thus the fetus was diagnosed as being affected and the pregnancy was terminated.
Conclusion This approach is fast and reliable for DNA-based prenatal diagnosis of Werdnig-Hoffmann disease.     

腰麻硬膜外联合麻醉在全产程中的镇痛效果及对母婴的影响

①目的　探讨腰麻硬膜外联合麻醉在全产程中的镇痛效果以及对母婴的影响。②方法　选择ASAⅠ～Ⅱ级、无禁忌证的单胎头位临产初产妇 30 0例 ,随机分为腰硬组 (腰麻硬膜外联合麻醉 )、硬外组 (硬膜外麻醉 )和对照组 (未用任何麻醉方法 )各 10 0例。行L2～ 3 椎间隙一点穿刺并一次成功。分别观察镇痛效果、起效时间、用药量、副作用、产程、分娩方式及母婴情况。③结果　腰硬组镇痛效果、起效时间以及用药量明显优于硬外组(uc=5 .34,t=16 .92～ 2 9.6 9,P <0 .0 1) ;与对照组比较 ,宫颈扩张加速 ,第一产程明显缩短 ,而第二产程延长 (t =3.34～ 4 8.4 9,P <0 .0 1) ,剖宫产率明显下降 ,而阴道助产率增高 ,胎儿宫内窘迫的发生率下降 (χ2 =6 .82～ 2 0 .35 ,P <0 .0 1)。④结论　腰麻硬膜外联合麻醉用于分娩镇痛优于硬膜外麻醉 ,是一种安全有效、更适合全产程镇痛的麻醉方法。     

丹参注射液椎管内局部灌注对急性脊髓损伤的保护作用

目的 探讨丹参对急性脊髓损伤的防治作用。方法 以改良Allen's法造成兔不完全性脊髓损伤的模型,硬膜下插管。随机分成丹参治疗组和对照组。术后按每天0.3ml/kg体重的总量分4次从硬膜下导管推入丹参注射液,对照组推入生理盐水。损伤后8、72h对脊髓损伤区进行过氧化物歧化酶(SOD)、丙二醛(MDA)、组织形态学观察、神经元凋亡、bcl-2等进行评价。结果 丹参组SOD含量高于对照组(P<0.01),MDA含量低于对照组(P<0.01)。细胞凋亡数目TUNEL法丹参组低于对照组(P<0.01),流式细胞术检测凋亡丹参组低于对照组(P<0.05)。bcl-2的表达丹参组高于对照组(P<0.05)。神经元及神经纤维变性、坏死轻于对照组。结论 丹参能改善损伤脊髓微循环,抑制和减轻脊髓损伤后的两种死亡方式坏死和凋亡。     

胸椎骨折合并胸外伤的外科治疗

目的　总结 17例胸椎骨折患者的特点与诊疗情况 ,为提高此类合并胸外伤患者的疗效提供有效的治疗方案。方法　分析了 17例胸椎骨折患者的临床特点、诊疗经过、近远期随访结果。结果　 14例 (82 .4 % )合并肋骨骨折 ,11例 (6 4 .7% )合并血气胸 ,10例 (5 8.8% )合并严重脊髓伤 ,3例 (30 % )远期脊髓伤为有用恢复。结论　胸椎骨折常合并肋骨骨折、血气胸、严重脊髓损伤 ,预后较差 ,为此应重视合并胸外伤的胸椎骨折的围手术期处理     

无神经症状寰枢椎骨折的非手术治疗

目的探讨无神经症状寰枢椎骨折患者的非手术治疗效果。方法7例无神经症状的寰枢椎骨折患者行牵引后,再行头颈胸石膏或颈托外固定,其中1例枢椎椎体骨折患者仅行颈托外固定。结果随访3-8个月,所有患者骨折均临床愈合,枕颈部痛均消失,颈椎活动范围轻度减小。结论对无神经症状的寰枢椎骨折患者进行选择性非手术治疗是一种安全、有效的方法,适合在基层医院开展。