神经毒剂急性中毒时大鼠脑内GABA受体结合活性的变化

目的：通过探讨γ－氨基丁酸（ＧＡＢＡ）受体在神经毒剂急性中毒时的活性状态,为临床治疗此类中毒引起的中枢惊厥症状提供新的思路。方法：提取含大鼠脑神经末梢微囊ＧＡＢＡ受体的匀浆液,通过大鼠体外实验、体内染毒实验（动物抽搐发作和未发作）来观察ＧＡＢＡ受体变化。结果：在体外实验中,１０ｍｍｏｌ．Ｌ＾－１的梭曼和丙氟磷均能显著降低大鼠ＧＡＢＡ配体与受体的结合率（Ｐ〈０．０１）,１ｍｍｏｌ．Ｌ＾－１的梭曼仍能显著降低ＧＡＢＡ受体的结合率（Ｐ〈０．０５）。大鼠皮下注射梭曼９９μｇ．ｋｇ＾－１发现＾３Ｈ－ＧＡＢＡ的结合值在抽搐发作时显著降低;大鼠腹腔注射丙氟磷６ｍｇ．ｋｇ＾－１,＾３Ｈ－ＧＡＢＡ的结合值亦显著降低。结论：神经毒剂在一定浓度下能显著降低大鼠脑ＧＡＢＡ受体的结合率,提示ＧＡＢＡ受体参与了某些神经毒剂的急性中毒过程。     

大鼠氧惊厥时脑内μ-阿片受体的变化

目的　探讨大鼠氧惊厥时脑内 μ-阿片受体的变化。方法　用 [3H]-羟甲芬太尼作为特异性标记配体 ,采用放射配体受体结合实验 (radioligand binding assay,RBA) ,测定在几种不同气体及压力的暴露条件下 ,大鼠脑内 μ-阿片受体的 k D值和 Bmax值的变化。结果　大鼠氧惊厥前 ,脑内 μ-阿片受体的 k D值即有增大趋势 (但 P>0 .0 5 ) ,Bmax值减小 (P<0 .0 1) ;氧惊厥时 k D值进一步升高 (P<0 .0 1) ,Bmax值反而增大 (P<0 .0 1)。结论　结果提示 :(1)氧惊厥发作中 ,μ-阿片受体的数量增多 ,而其结合活性降低。(2 )在高压氧 (HBO)暴露中 ,μ-阿片受体参与了氧惊厥的过程     

大鼠吗啡精神依赖时脑区氨基酸类神经递质的变化

目的建立条件性位置偏爱模型,检测吗啡精神依赖大鼠不同脑区中氨基酸类神经递质含量的变化。方法用4mg·kg-1盐酸吗啡对雄性SD大鼠进行条件性位置偏爱(CPP)训练。CPP形成后将大鼠断头处死,立即取脑,分离杏仁核、额叶皮层、海马、下丘脑、伏隔核、纹状体、丘脑、小脑等8个核团,在高氯酸溶液中做组织匀浆,同时沉淀蛋白,离心后取上清液备测。采用柱前衍生-电化学检测-高效液相色谱法测定谷氨酸(GLU)和γ-氨基丁酸(GABA)含量。结果吗啡使大鼠形成CPP时,额叶皮层、下丘脑和伏隔核的GLU和GABA含量均有明显下降(P<0.05),其中以伏隔核变化最明显(P<0.01);而且,伏隔核中的GLU/GABA值显著升高(P<0.05)。结论大鼠对吗啡的精神依赖形成时,中枢GLU和GABA的含量变化集中于额叶皮层、下丘脑和伏隔核等与奖赏作用关系密切的脑区,证明了GLU和GABA系统参与了精神依赖形成时药物在脑内的奖赏作用。伏隔核中的GABA含量显著下降,GLU/GABA值显著升高,表明吗啡精神依赖时伏隔核处于去抑制状态。     

纹状体A_(2A)R和D_2DR对大鼠力竭运动过程中苍白球GABA和Glu释放的调控研究

目的:探讨纹状体腺苷A2A受体(A2AR)和多巴胺D2受体(D2DR)对大鼠力竭运动过程中苍白球胞外γ-氨基丁酸(GABA)与谷氨酸(Glu)释放的调控作用。方法:采用纹状体微量灌注和活体微透析-高效液相联用技术,实时、在线观察大鼠在一次力竭运动过程中苍白球细胞外液中GABA和Glu水平的动态变化规律,以及D2DR激动剂(喹吡罗,Quinpirole)和A2AR拮抗剂(SCH58261)对其影响,结合运动能力探讨D2DR和A2AR对疲劳的调控作用机制。结果:大鼠3级递增负荷跑台运动至力竭过程中,苍白球胞外Glu和GABA呈增高趋势,Glu/GABA呈降低趋势,在运动开始后45min至力竭各点Glu和GABA均显著高于安静水平(P<0.05),Glu/GABA显著低于安静水平(P<0.05),力竭后恢复90 min时Glu和GABA逐渐下降至安静水平,Glu/GABA逐渐恢复至安静水平;SCH58261和Quinpirole分别经纹状体灌注后,力竭运动过程中苍白球胞外Glu和GABA变化明显下降,大鼠自主运动期(疲劳初期)时间延长,大鼠跑台运动至力竭时间显著增加(P<0.05)。结论:在一次力竭运动过程中,大鼠苍白球神经元胞外Glu、GABA浓度及Glu/GABA均具有明显的阶段性特征,推测可能是力竭过程中大鼠运动能力呈现阶段性变化特征的机制之一;大鼠在力竭时,苍白球胞外Glu、GABA升高但Glu/GABA下降,推测力竭时大鼠苍白球神经元的兴奋性下降;SCH58261和Quinpirole经纹状体微量注射后,苍白球胞外Glu和GABA变化明显下降,大鼠自主运动期(疲劳初期)时间延长,大鼠跑台运动至力竭时间显著增加,推测可能是因为SCH58261和Quinpirole分别经各自作用机制干预了纹状体投向苍白球的GABA能传递而影响了间接通路对皮层的调控,最后达到延缓疲劳的作用。     

μ型阿片肽受体对癫痫敏感大鼠海马γ-氨基丁酸神经元影响

目的探讨μ型阿片肽受体(MORs)介导大鼠癫痫敏感性形成过程中海马γ-氨基丁酸(GABA)神经元的变化。方法红藻氨酸(KA)皮下注射建立大鼠癫痫发作模型,采用脑立体定位及微渗透泵技术,海马内微量注射MORs激动剂吗啡感受素(PL017)或拮抗剂β-呋纳曲胺(β-FNA)。7 d后通过阈下剂量KA检测大鼠癫痫发作敏感性,应用免疫组织化学方法观察海马齿状回及门区GABA神经元数目和灰度变化。结果 KA诱导癫痫敏感性形成大鼠的海马齿状回及门区GABA神经元数目明显减少,染色强度减低。PL017可进一步减少海马齿状回及门区GABA神经元数目及其染色强度,而β-FNA能够明显改善KA及PL017对GABA神经元的损伤作用。结论 MORs介导癫痫发作敏感性形成机制与海马齿状回及门区GABA神经元损伤有关。     

γ射线诱发小鼠γ-氨基丁酸受体结合活性改变和神经行为变化的观察

目的观察电离辐射对γ-氨基丁酸(GABA)受体功能的影响以及动物受照射后神经行为的变化。方法采用^60Coγ射线照射小鼠头部，观察不同剂量辐射对小鼠脑内神经细胞中GABA受体活性及其功能结合位点的影响，并对小鼠行为活动改变进行测定。结果辐射可显著降低神经细胞中GABA受体生物结合活性，表现为GABA受体蛋白平衡解离常数(Kd)升高，结合活性降低。受照射后GABA受体的异常变化与其受照射剂量有关。受照射小鼠行为测试结果显示：照射48h后，动物表现出燥动、焦虑等行为活动异常表现，与注射GABA受体阻断剂动物的行为活动变化相一致。结论电离辐射可引起GABA受体活性改变。根据GABA受体阻断剂动物的行为变化实验结果，推测受照射后GABA受体功能和结合活性变化是引发神经行为变化的直接因素。     

实验性癫痫大鼠海马损害与磁共振波谱对照研究

目的 :观察癫痫持续不同时间氢质子磁共振波谱 (1 H MRS)检测的致痫灶 NAA和 Cho异常与海马结构损害的相关性。方法 :2 1只 Wistar大鼠 ,实验组 15只 ,10 % Pilocarpine 35 0 mg/ kg腹腔注射 ,诱发反复全面强直阵挛发作 ,光镜观察发作持续 5min至 6 0 h大鼠海马区神经元和胶质细胞变化 ,并计数海马 CA1 和 CA3段残存正常神经元数量 ;离体1 H MRS测定代谢产物 NAA和 Cho含量变化。结果 :癫痫持续 (SE) 5～ 30 min,光镜观察到神经元变性 ,1 HMRS检测出 NAA值降低 ;SE30 min～ 3h部分神经元坏死、少许丢失 ,轻度胶质增生 ,NAA明显降低 ;SE3～ 6 h后 ,大部分神经元坏死、丢失 ,胶质增生明显 ,形成典型的海马硬化 ;除NAA值降低外 ,1 HMRS还检测出 Cho值升高。结论 :1 HMRS检出的 NAA可反映癫痫脑损害程度 ,并且癫痫发作持续时间与 NAA值和残存正常神经元数量呈显著的负相关。Cho值升高在海马硬化形成后检出 ,可能反映胶质增生     

低氧和运动训练对大鼠学习记忆功能的影响及其与海马突触功能可塑性之间的关系

目的:探讨低氧和运动训练对大鼠学习记忆的作用和交互作用及其与海马突触传递功能之间的关系。方法:采用交互设计的研究方案对SD大鼠进行8周14.2%的低氧暴露或/和60 min的无负重游泳训练后,通过Morris水迷宫检测大鼠的学习和记忆能力,并测定海马组织中γ-氨基丁酸(GABA)含量和N-甲基-D-天门冬氨酸受体(NMDAR)亚基NR1、NR2B的m RNA表达量。结果:1长期的低氧暴露可使大鼠的潜伏期显著增加(P<0.05),穿越平台的次数显著减少(P<0.05),运动训练能使大鼠的潜伏期显著缩短(P<0.05),穿越平台的次数显著增加(P<0.05),低氧联合运动训练对缩短大鼠潜伏期、提高大鼠穿越平台次数没有显著的交互作用(P>0.05)。2慢性低氧暴露能显著降低海马组织中NR1和NR2B m RNA的表达(P<0.05),运动训练能显著提高海马组织中NR1和NR2B的m RNA表达和降低GABA含量(P<0.05),低氧联合运动训练对海马组织中NR1、NR2B m RNA表达的提高和GABA含量的降低没有显著的交互作用(P>0.05)。结论:1长期的低氧暴露可抑制学习记忆能力,而运动训练能够增加学习记忆能力,虽然运动训练在一定程度上可以改善低氧暴露大鼠的学习记忆能力,但是并不能完全逆转低氧暴露所造成的学习能力下降。2长期的低氧暴露或运动训练可下调或上调海马NR1和NR2B m RNA表达,抑制或增强海马突触功能可塑性,这可能是影响学习记忆能力的重要机制。     

大鼠脑内3H-MK-801结合位点受体放射自显影

目的　研究大鼠脑内 (第 2 9层面 )N 甲基 D 门冬氨酸 (NMDA)受体的分布特征。方法采用3 H MK 80 1为配基的受体放射自显影体外结合实验。结果　3 H MK 80 1结合位点在大鼠脑内的分布广泛而不均匀 ,海马区密度最高 (CA1>DGmb >DGlb >CA3) ,其他依次为杏仁核、大脑皮层、纹状体尾状核、丘脑核团和下丘脑腹内侧区。结论　3 H MK 80 1结合位点的分布密度可反映NMDA受体的分布情况。     

知母皂苷对衰老大鼠脑乙酰胆碱受体的调节作用

目的：研究知母皂苷（SAaB)对衰老大鼠脑乙酰胆碱受体的影响。方法：采用放射受体配体结合实验,测定大鼠脑皮层M,N受体的密度及亲和力。结果：与正常成年大鼠比较,衰老大鼠脑皮层M受体的密度和亲和力我明显变化,而脑N受体的密度显减少;SAaB能剂量依赖性地增加衰老大鼠脑N受体的数目,对MC受体无明显影响。结论;SAaB对衰老大鼠脑N受体有上调作用。     

成批煤气爆燃烧伤的救治体会

报道治疗因煤气泄漏爆炸烧伤病员7例，经应用MEBT技术积极救治，其中6例于伤后17天痊愈出院，另一例特重伤员也于伤后30天康复出院。作者认为：应严格按照MEBT／MEBO要求进行规范治疗，正确处理生命体征、休克、感染、脏器功能和创面的辨证关系。同时，不能忽视外科营养在过程中的重要作用，它是创面修复的物质保证。     

Glutamine supplementation in vitro and in vivo,in exercise and in immunodepression

In situations of stress, such as clinical trauma, starvation or prolonged, strenuous exercise, the concentration of glutamine in the blood is decreased, often substantially. In endurance athletes this decrease occurs concomitantly with relatively transient immunodepression. Glutamine is used as a fuel by some cells of the immune system. Provision of glutamine or a glutamine precursor, such as branched chain amino acids, has been seen to have a beneficial effect on gut function, on morbidity and mortality, and on some aspects of immune cell function in clinical studies. It has also been seen to decrease the self-reported incidence of illness in endurance athletes. So far, there is no firm evidence as to precisely which aspect of the immune system is affected by glutamine feeding during the transient immunodepression that occurs after prolonged, strenuous exercise. However, there is increasing evidence that neutrophils may be implicated. Other aspects of glutamine and glutamine supplementation are also addressed.     

新疆石河子地区奶牛隐性乳房炎的调查与分析

采用LMT法对新疆石河子地区三个规模化奶牛场泌乳牛群进行了隐性乳房炎检测,共检测994头泌乳牛3976个乳区.结果表明:奶牛隐性乳房炎阳性率为81.9%,乳区阳性率为49.1%.数据分析表明,不同年龄、胎次以及有无卧床奶牛的隐性乳房炎阳性率差异显著(P<0.05),后乳区的隐性乳房炎感染率显著高于前乳区感染率(P<0.05),隐性乳房炎乳区发生数也明显影响当日产奶量(P<0.05).     

Sex differences in neuromuscular fatigability in response to load carriage in the field in British Army recruits

Objectives

Women are resistant to neuromuscular fatigue compared to men in response to a range of exercise tasks. The sex differences in the neuromuscular responses to load carriage have yet to be investigated.

Decrease in eccentric hamstring strength in runners in the Tirol Speed Marathon

Background

The local muscular endurance of knee flexors, during eccentric work in particular, is important in preventing or delaying kinematic changes associated with fatigue during treadmill running. This result, however, may not be transferable to overground running.

Objective

To test the hypothesis that overground running is associated with eccentric hamstring fatigue.

Methods

Thirteen runners (12 male and one female) performed an isokinetic muscle test three to four days before and 18 hours after a marathon. Both legs were tested. The testing protocol consisted of concentric and eccentric quadriceps and hamstring contractions.

Results

There were no significant differences between peak torque before and after the race, except that eccentric peak hamstring torque (both thighs) was reduced.

Conclusion

Overground running (running a marathon) is associated with eccentric hamstring fatigue. Eccentric hamstring fatigue may be a potential risk factor for knee and soft tissue injuries during running. Eccentric hamstring training should therefore be introduced as an integral part of the training programme of runners.     

肺心病慢性呼吸性酸中毒合并代谢性酸碱失衡判断方法探讨(附80例次血气分析)

目的：对42例肺心病慢性呼吸性酸中毒患者的80例次血气测定结果。方法：用不同的酸碱图（卡）及代偿公式进行酸碱类型的初步差别分析。结果：结合临床表现、各种影响因素与治疗反应等作出综合判定。结论：比较二种判定的差异，并提出较为实用、可靠的判断建议，以助于复合型呼吸性酸碱失衡的临床诊断与处理。     

Oxalosis in primary hyperoxaluria in infancy

Primary hyperoxaluria (PH1) is a rare inborn autosomal recessive metabolic disorder due to the deficiency of hepatic alanine-glyoxylate-aminotransferase. This deficiency results in excessive synthesis and urinary excretion of oxalate, inducing renal stone formation and deposition of calcium oxalate in the kidney, bone, myocardium, and vessels (systemic oxalosis, SO) in the most severely affected individuals. We report renal and skeletal changes in a 3-month-old girl with PH1 and SO. Intense cortico-medullary hyperechogenicity and increased homogeneous radiopacity of normal-sized kidneys suggested the diagnosis of SO. Skeletal survey showed osteopenia and characteristic symmetrical metaphyseal transverse bands in long bones, progressively becoming more dense and migrating towards the diaphysis. Multiple pathological and slowly healing fractures of the limbs occurred at the dense band level. A radiopaque rim was then observed in flat bones, epiphyseal nuclei, and vertebral bodies. Inflammatory granulomatous reaction, induced by the presence of oxalate crystals in the marrow spaces, coexisted with progressively evident radiological signs of secondary hyperparathyroidism, with partially overlapping features. The patient was treated by peritoneal dialysis and hemodialysis until combined liver–kidney transplantation. There are no previous reports of infants treated with hemodialysis for more than 2 years.     

Interventional radiology in oncology in private practice

Interventional oncology in private practice requires expert training and can be performed in a stand-alone facility for type 1 procedures in a hospital setting for type 2 and 3 procedures where subspecialized radiologists, state-of-the-art equipment, and postprocedure hospital monitoring are available. A multidisciplinary effort with oncologists, internal medicine physicians and anesthesiologists is necessary. The practice of interventional oncology requires around the clock availability, meticulous and established protocols and procedures and a financial investment. On the other hand, it is professionally gratifying because of constant technical advances and the impact on patients.