预处理的脑保护机制及应用

此文论述了通过预处理的内源性神经保护作用对脑的损伤性因素产生耐受的机制及相关因素,并认为线粒体在其中扮演了重要的角色.通过探讨预处理的研究方法,展望其临床应用.     

预处理的脑保护机制及应用

此文论述了通过预处理的内源性神经保护作用对脑的损伤性因素产生耐受的机制及相关因素,并认为线粒体在其中扮演了重要的角色.通过探讨预处理的研究方法,展望其临床应用.     

腺苷预处理对法洛四联症根治术婴幼儿心肌和脑的保护作用

已在动物实验和人体证实,心脏直视手术可造成心肌损伤和脑损伤,腺苷可减轻心肌损伤[1],对脑损伤的保护作用不清.本研究旨在观察腺苷预处理对法洛四联症(TOF)根治术婴幼儿心肌和脑的保护作用.     

神经生长因子预处理对鼠脑皮质培养细胞缺血／再灌注损伤的保护作用

目的：比较不同浓度神经生长因子（NGF）预处理离体幼鼠脑皮质培养细胞对脑缺血／再灌注（cerebral ischemia-reperfusion injury,I／R）损伤的保护作用。方法：取出生24h内的SD乳鼠脑皮质细胞,体外培养至第7日随机分为正常对照组、药物损伤组、及10、50、100ug／l神经生长因子预处理组。各预处理组分别以对应浓度的药物进行预处理,24h后除正常对照组外,各组予20μmol／L谷氨酸损伤0．5h,换正常培养液继续培养24h后进行观察。检测神经细胞存活率（MTT法）,乳酸脱氢酶（LDH）漏出率,细胞凋亡率;苏本素-伊红（HE）染色后倒置相差显微镜下观察细胞形态变化。结果：各浓度神经生长因子预处理组的细胞存活率高于药物损伤组,LDH漏出量和细胞凋亡率不同程度的低予药物损伤组;各药物预处理组细胞形态的受损程度均较药物损伤组轻。三个预处理组中以50ug／l组效果最佳。结论：不同浓度的神经生长因子提前24h预处理离体幼鼠脑皮质培养细胞对脑I／R损伤均有保护作用,其中50ug／l神经生长因子预处理效果最佳。     

地氟醚对脑缺血再灌注损伤鼠的神经行为及凋亡相关基因Bcl-2、Bax表达的影响

临床上常见的休克、心力衰竭、脑血管狭窄或阻塞合并低血压均可引起脑缺血、缺氧,并造成的脑组织不同程度的损伤,而几乎所有的病例均遗留不同程度的残疾。因此,加强术前期脑保护已被众多麻醉医师所关注。目前,临床上采用的低温及静脉麻醉药硫喷妥钠、利多卡因等对脑的保护作用已明确[1～3],随着吸入药异氟醚对心脏及脑功能保护作用的深入研究[4～7],许多研究发现地氟醚具有脑保护的作用。然而,有关地氟醚预处理对脑缺血再灌注损伤大鼠行为学影响的报道还很少。本研究通过行为学指标观察地氟醚对脑缺血再灌注损伤大鼠的脑保护作用。另外,地氟…     

电针刺在急性肺损伤中的保护机制

背景 急性肺损伤(acute lung injury,ALI)发病率和病死率较高,治疗棘手,是临床常见的急危重症. 目的 阐述动物实验研究中电针刺对ALI的可能保护机制. 内容 电针刺对ALI的保护机制可能涉及维持氧化/抗氧化系统平衡、促炎/抗炎反应平衡、神经内分泌系统平衡,血管舒缩功能平衡及减轻缺血/再灌注损伤等. 趋向 导致ALI因素多样、机制复杂,电针刺激可能通过调节机体内源性保护系统从不同环节对受损伤肺脏起保护作用,且各环节之间相互联系.     

缺血预处理对鼠后肢缺血再灌注下脊髓腰骶膨大运动神经元的保护作用

[目的]对大鼠一侧后肢的缺血再灌注损伤行不同条件缺血预处理,观察脊髓腰骶膨大处运动神经元超微结构的变化,探讨其保护作用.[方法]通过血管夹暂时阻断大鼠左侧髂总、髂内和髂外动脉,建立大鼠后肢缺血模型.以缺血6h再灌注2h和12 h分为A、B两组,预处理方式为缺血10 min血液复流10 min,按无预处理、预处理1次、无时间间隔预处理2、3次,分成A0、A1、A2、A3;B0、B1、B2、B3组.取材腰骶膨大处脊髓灰质前角,光镜及透射电镜下观察不同条件预处理对缺血再灌注损伤中脊髓前角超微结构变化.[结果]组织形态观察结果显示A0组缺血再灌注损伤后神经元细胞减少,核溶解消失,损伤明显,预处理后神经元细胞增多,可见部分细胞核存在;B0组缺血再灌注损伤后神经元细胞大部分坏死溶解,预处理后坏死溶解现象减轻.超微结构观察显示A0和B0组脊髓前角神经兀细胞不同程度核周器扩张损伤,出现内质网扩张、大量线粒体空泡以及核膜溶解消失.预处理后损伤程度有所减轻,叠加预处理后损伤进一步减轻.[结论]缺血预处理能减轻大鼠肢体缺血再灌注下脊髓腰骶膨大运动神经元的损伤,对脊髓具有保护作用.反复3次预处理产生的保护作用优于2次预处理及1次预处理.     

电针预处理脑保护的研究进展

背景 如何减轻脑缺血损伤仍是一个世界性的难题和亟待解决的问题.预处理和缺血耐受的发现为防治缺血性脑损伤的研究提供了新思路.目的 分析总结电针(electroacupuncture,EA)预处理脑保护的作用及其相关机制的文献资料.内容 描述了EA预处理的发现；与“逆针灸”的关系；适宜参数和作用规律和可能作用机制.趋向 E...     

缺血预处理与肝脏缺血再灌注损伤的研究

目的 :观察缺血预处理对肝脏再灌注损伤的影响。方法 :通过构建正常大鼠和肝硬化大鼠肝脏 70 %的原位热缺血再灌注损伤模型 ,比较缺血预处理和无预处理组及间歇阻断肝门法对再灌注损伤的影响 ;以肝功酶、能量代谢和过氧化损伤等生物化学指标、组织学病理和细胞超微结构的形态学指标 ,观察不同预处理条件对结果的影响。结果 :各项指标显示 ,正常大鼠中 ,缺血预处理与无预处理组相比 ,可显著减轻再灌注损伤 (P <0 .0 5 ) ,与间歇性阻断肝门组相比也有显著性意义 (P <0 .0 5 ) ;在各个缺血预处理组内 ,缺血预处理 5min(IPC5min)组较IPC10min组和IPC5min× 2 组效果好 (P <0 .0 5 ) ,证实缺血预处理对肝硬化大鼠肝脏再灌注损伤有保护作用。结论 :缺血预处理可减轻肝脏再灌注损伤 ,并优于间歇性阻断肝门法 ,是一种应用方便、效果较好、前景广阔的阻断肝脏血供的新方法     

预处理对病理状态下心脏缺血/再灌注损伤的影响

背景 缺血性心脏病被认为是世界范围内人类发病和死亡的主要原因;预处理,包括缺血预处理(ischemic preconditioning,IP)和药物预处理在正常心肌中的保护作用已得到证实.目的 了解合并心血管相关危险因素等病理条件下预处理对心脏缺血/再灌注(ischemia/reperfusion,I/R)的影响.内容 就近年来在某些病理状态下(如高血脂、糖尿病、高血压、老龄化及肥胖等)预处理对心脏缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)的作用及可能机制的研究简要作一综述.趋向 为进一步研究相关的心脏保护策略提供思路.     

针刺调节缺血性脑血管病围手术期脑血流量和脑神经功能的研究进展

背景 针刺成为卒中后康复治疗的重要辅助措施之一.目的 综述针刺治疗脑卒中的临床进展及其调节机制.内容 针刺可明显改善卒中后抑郁(post-stroke depression,PSD)状态,促进偏瘫恢复,降低痉挛状态的发生率,促进认知功能的恢复.此外,针刺可预防颈动脉内膜剥脱术(carotid endarterectomy,CEA)及血管内支架置入术(carotid artery stenting,CAS)术后的再灌注综合征.针刺通过多种机制改善卒中后状态:改善脑缺血局部微循环,拮抗氧自由基损伤,控制炎症反应,减少血栓形成,调节信号转导通路及蛋白质,促进侧支循环等.趋向 针刺对脑卒中的治疗效果肯定,其可通过多种途径调节卒中后脑神经功能状态.但将针刺应用于脑卒中手术术中的效果仍需进一步研究.     

Specific Effects of Laserpuncture on the Cerebral Circulation

. Acupuncture is a form of traditional Chinese medicine that has developed over thousands of years. We studied the effects of laser puncture, needle acupuncture, and light stimulation on cerebral blood flow in 15 healthy volunteers (mean age 25.0±1.9 years, 5 female, 10 male) with non-invasive transcranial Doppler sonography. In addition 40-Hz stimulus-induced brain oscillations, heart rate, blood pressure, peripheral and cerebral oxygen saturation, and the bispectral index of the EEG were recorded. Stimulation with light significantly increased blood flow velocity in the posterior cerebral artery (p<0.01, ANOVA). Similar but less pronounced effects were seen after needle acupuncture (p< 0.05, ANOVA) and laserpuncture (n.s.) of vision-related acupuncture points. Furthermore both, laserpuncture and needle acupuncture, led to a significant increase in the amplitudes of 40-Hz cerebral oscillations. Stimulation of vision-related acupuncture points with laser light or needle acupuncture elicits specific effects in specific areas of the brain. The results indicate that the brain plays a key intermediate role in acupuncture. However, brain activity of itself does not explain anything about the healing power of acupuncture. Paper received 10 May 1999; accepted after revision 23 August 1999.     

Acupuncture treatment for a patient with diffuse axonal injury--report no. 2

Acupuncture has been applied as a therapeutic technique in China, Japan and East Asia. Recently, its application is extended to treat neural injuries. We describe a 26-year-old man with consciousness disturbance and intense muscle spasticity of extremities due to severe diffuse axonal injury (DAI) in whom acupuncture treatment for 1 month was effective to alleviate these symptoms remarkably. We also investigated the cerebral blood flow two times by 123I-IMP SPECT in acupuncture period. Acupuncture treatment may be effective to improve consciousness disturbance and intense spasticity of DAI and to modulate cerebral blood flow.     

Perioperative acupuncture and related techniques

Acupuncture and related techniques are increasingly practiced in conventional medical settings, and the number of patients willing to use these techniques is increasing. Despite more than 30 yr of research, the exact mechanism of action and efficacy of acupuncture have not been established. Furthermore, most aspects of acupuncture have yet to be adequately tested. Therefore, considerable controversy remains about the role of acupuncture in clinical medicine. Acupuncture apparently does not reduce volatile anesthetic requirement by a clinically important amount. However, preoperative sedation seems to be a promising application of acupuncture in perioperative settings. Acupuncture may be effective for postoperative pain relief but requires a high level of expertise by the acupuncture practitioner. Acupuncture and related techniques can be used for treatment and prophylaxis of postoperative nausea and vomiting in routine clinical practice in combination with or as an alternative to conventional antiemetics when administered before induction of general anesthesia.     

针灸联合补阳还五汤加味治疗脑梗死的疗效观察

目的：观察针灸联合补阳还五汤加味治疗脑梗死的临床疗效。方法对确诊的76例脑梗死患者,随机分为治疗组和对照组各38例,对照组予以西药治疗辅以康复训练,治疗组则在对照组治疗的基础上采用针灸联合补阳还五汤治疗,治疗4周后进行疗效评价。结果治疗组总有效为92.1%,高于对照组76.3%,差异有统计学意义（P＜0.05）。结论针灸联合补阳还五汤加味治疗脑梗死可明显提高临床疗效,是治疗脑梗死可选择的有效方法。     

Acupuncture using laser needles modulates brain function: first evidence from functional transcranial Doppler sonography and functional magnetic resonance imaging

Acupuncture using laser needles is a new totally painless stimulation method which has been described for the first time. This paper presents an experimental double-blind study in acupuncture research in healthy volunteers using a new optical stimulation method. We investigated 18 healthy volunteers (mean age±SD: 25.4±4.3 years; range: 21–30 years; 11 female, 7 male) in a randomized controlled cross-over trial using functional multidirectional transcranial ultrasound Doppler sonography (fTCD; n=17) and performed functional magnetic resonance imaging (fMRI) in one volunteer. Stimulation of vision-related acupoints resulted in an increase of mean blood flow velocity in the posterior cerebral artery measured by fTCD [before stimulation (mean±SE): 42.2±2.5; during stimulation: 44.2±2.6; after stimulation: 42.3±2.4 cm/s, n.s.]. Mean blood flow velocity in the middle cerebral artery decreased insignificantly. Significant changes (p<0.05) of brain activity were demonstrated in the occipital and frontal gyrus by fMRI. Optical stimulation using properly adjusted laser needles has the advantage that the stimulation cannot be felt by the patient (painless and no tactile stimulation) and the operator may also be unaware of whether the stimulation system is active. Therefore true double-blind studies in acupuncture research can be performed.     

Acupuncture and kidney disease

Acupuncture as a complex therapeutic system has been used to treat a variety of diseases and pathological conditions. Although the exact mechanism(s) of acupuncture remains unknown, some evidence suggests a mechanism initially involving signal transduction through connective tissue, with secondary involvement of other systems including the nervous system. Acupuncture has become increasingly popular in the Western countries as a therapy for pain and several chronic disorders difficult to manage with conventional treatments. Acupuncture and acupuncture-like somatic nerve stimulation have been used in different kidney diseases and several complications related to them. The effect of acupuncture techniques in some kidney diseases is reviewed on the basis of clinical reports as well as mechanisms that may possibly explain the beneficial effects mediated by acupressure/acupuncture. The potential effect of acupressure techniques in renal inflammation and whether these effects could be mediated through the newly identified cholinergic anti-inflammatory pathway are discussed.     

针刺在防治术后认知功能障碍中的机制研究进展

术后认知功能障碍(postoperative cognitive dysfunction,POCD)可导致患者术后发展为痴呆的可能性大大增加,影响患者预后,并增加医疗护理成本和家庭负担。基础研究表明,针刺可通过多重作用机制起到一定的脑保护效应,降低POCD的发生率。文章回顾了近年针刺在POCD领域内的研究进展,综述了可能存在的几种相关机制,包括抑制神经炎症、抑制氧化应激水平、减少神经元损伤、增强突触可塑性以及调节微生物菌群脑-肠轴等。将针刺应用于POCD确实取得了一定的成果,但其作用机制仍未完全明确。随着针刺研究的不断深入,需要尽快明确其作用机制,以便于更好地指导POCD的临床治疗。     

Cerebral protection selection in aortic arch surgery for patients with preoperative complications of cerebrovascular disease.

OBJECTIVE: Retrograde perfusion is gaining acceptance as a means of cerebral protection, but it remains unclear how long the brain is protected and whether it is effective in patients with preoperative cerebrovascular disease. METHODS: From January 1989 to August 1999, 205 patients--118 male and 87 female patients who ranged 12 to 86 years old, mean: 65.5 years old--underwent surgery at our hospital for aortic arch aneurysm using cerebral protection. We focused on mortality, stroke incidence and perioperative risk factor between 2 groups--selective cerebral and retrograde cerebral perfusion--also studying patients with preoperative cerebrovascular disease that influenced postoperative stroke. RESULTS: The hospital mortality was 11.7% (selective cerebral perfusion group: 12%, retrograde group: 10.9%). Stroke occurred in 11 patients (5.3%), 4.7% in the selective cerebral perfusion group and 7.3% in the retrograde group. Preoperative cerebrovascular disease does not appear to be a risk factor for postoperative brain damage in aortic arch surgery. Regarding total replacement of the aortic arch, the incidence of postoperative brain damage in the retrograde group with preoperative cerebrovascular disease was higher than that in another group (p = 0.072). Cardiopulmonary bypass time and selective cerebral perfusion time in the patients with postoperative stroke were significantly longer than that in non-stroke group. CONCLUSIONS: Preoperative cerebrovascular disease did not appear to be a risk factor in postoperative neurological deficit in the selective cerebral perfusion group. Prolonged selective cerebral perfusion time and cardiopulmonary bypass time may, however, lead to brain edema and cause neurological deficit.     

Medical management of head injury and neuroprotection

Head injury continues to cause significant mortality and morbidity despite the advances in early and late management and rehabilitation techniques. The extent and prognosis of brain injury are influenced by the primary impact and initiation of secondary mechanism. Outcome is also dependent on resuscitation and maintenance of cerebral oxygenation. The initial management is aimed at preventing secondary brain injury and identifying those patients who may benefit from surgical intervention. Continuing care is based on the careful and timely transfer to the appropriate intensive care environment where maintenance and monitoring of cerebral oxygenation are used. A variety of techniques involving the manipulation of both cerebral perfusion pressure and intracranial pressure are employed. There are a number of, as-yet, unproven techniques under examination for affecting cerebral metabolism to provide a degree of protection against further damage.