低剂量X射线全身照射对小鼠T淋巴细胞钙激活钾通道的影响

本文作者应用连细胞膜片钳技术，观察了低剂量Ｘ射线全身照射对小鼠Ｔ淋巴细胞钙激活钾通道［Ｋ（Ｃａ）］的影响。发现低剂量照射使ＣｏｎＡ（２０μｇ／ｍｌ）引起的Ｋ（Ｃａ）通道开放增强，表现为开放时间延长、开放概率增加，而对单通道电流幅值无明显影响。在淋巴细胞浸浴液中加入ＣｏｎＡ后３分钟，照射组动物淋巴细胞Ｋ（Ｃａ）通道开放概率明显高于对照组。而且照射后４～２４小时，Ｋ（Ｃａ）通道的激活随时间推移而逐步增强。所以Ｋ（Ｃａ）通道在低剂量放射增强免疫的机制中可能具有重要的意义。     

Lactate/H+ transport in skeletal muscle from spinal-cord-injured patients

In order to evaluate the effect of prolonged muscle inactivity on sarcolemmal lactate/H⁺ transport in humans, the lactate/H⁺ transport capacity was determined in the thigh muscle of spinal-cord-injured (SCI) individuals. The lactate transport rate was measured in sarcolemmal giant vesicles produced by collagenase treatment of muscle biopsies obtained from the vastus lateralis muscle. Six SCI subjects with total loss of motor and sensory functions of their lower limbs participated in the study. The duration of the injury ranged from 2 to 15 years. The total lactate transport rate in the muscle of SCI patients was 46.5±2.6 pmol · cm⁻²· s⁻¹ (mean±SEM), which corresponds to a 17% lower (P<0.05) transport rate than that found in healthy, untrained subjects. The estimated carriermediated lactate/H⁺ transport capacity was approximately 26% lower in the SCI patients than in healthy, untrained subjects. The observed muscle lactate/H⁺ transport capacity of SCI individuals is in accordance with a positive correlation between the capacity of the lactate/H⁺ transporters and the percentage occurrence of slow-twitch fibres in a muscle, although there seems to be a wide range of transport capacities within each fibre type. The present results show that the sarcolemmal lactate/H⁺ transport capacity is lower in SCI individuals than in normally physically active subjects, which indicates that prolonged muscle inactivity reduces the lactate/H⁺ transport capacity of human muscle.     

1/T1 NMRD profiles of solutions of Mn2+ and Gd3+ protein-chelate conjugates

Bovine immunoglobulins (IgG) and bovine serum albumin (BSA) were multiply labeled with multidentate ligands, either ethylenediaminetetraacetic acid (EDTA) or diethylenetriaminepentaacetic acid (DTPA), and metal ions were inserted to form the ternary protein-ligand-ion conjugates. The NMRD profiles (the magnetic field dependence of 1/T1) of solutions of the ternary conjugates differ greatly from those of the corresponding binary ligand-metal-ion complexes, both in magnitude and functional form, exhibiting 5- to 10-fold greater relaxivities and prominent peaks near 20 MHz. The inference is that the protein-bound chelates are relatively rigidly attached to the macromolecules. The structure and metal ion affinities of these novel conjugates, as well as the relevance to contrast enhancement in NMR imaging, is discussed.     

56Fe17+、12C6+重离子束照射后人淋巴细胞基因转录谱的改变

目的 探讨重离子束照射对人淋巴细胞基因转录谱的改变。方法 人淋巴细胞Peng-EBV分别经0.1、0.5和2 Gy ⁵⁶Fe¹⁷⁺、¹²C⁶⁺重离子束照射后,提取各实验组细胞总RNA,利用Agilent人表达谱基因芯片进行基因转录谱的检测并筛选差异表达基因;对差异表达基因进行GO分析;利用KEGG数据库对差异表达基因进行通路分析。结果 Peng-EBV细胞系经⁵⁶Fe¹⁷⁺、¹²C⁶⁺重离子束照射后,0.1、0.5和2.0 Gy剂量组共同差异表达基因分别为101、199和229个。3个剂量组共同差异表达基因14个,其中,GPSM1、TSPYL5、WFDC2、LAD1等基因在两种离子束各剂量组呈现特征性差异表达。0.1和0.5 Gy剂量组涉及主要基因功能包括细胞粘连、胞外基质构建等,参与的显著性Pathway通路分别为3和6条,主要为细胞因子受体相互作用通路等。2 Gy剂量组主要基因功能包括细胞黏连、Rho蛋白信号转导调节等,参与的显著性Pathway通路3条,主要为p53信号通路等。结论 ⁵⁶Fe¹⁷⁺、¹²C⁶⁺重离子束可诱导人淋巴细胞基因转录谱的改变,且不同剂量重离子可诱发不同的差异表达基因及通路。     

12C6+重离子束照射人淋巴细胞蛋白质组分析

目的 探讨¹²C⁶⁺离子束照射对人淋巴细胞蛋白质组的影响。方法 将人淋巴细胞Peng-EBV按照射剂量分为0.1、0.5和2.0 Gy组,未照射为对照组。使用¹²C⁶⁺离子束进行照射,吸收剂量率为0.3~0.5 Gy/min。利用同位素标记的相对和绝对定量技术（iTRAQ）分析受照淋巴细胞的蛋白质表达,筛选出差异表达蛋白质。对差异表达的蛋白质进行基因本体（GO）分析、相互作用网络分析及通路分析。结果 在4组样品中共鉴定到5 158种蛋白质,与对照组相比,0.1 Gy组差异蛋白质有91种,0.5 Gy组有191种差异蛋白质,2.0 Gy组有68种差异蛋白质;3组共同差异表达的蛋白质有11种,其中,7种蛋白质表达上调,4种下调。对3个剂量组的差异表达蛋白质进行生物信息学分析显示,这些蛋白质主要与生物代谢及其调节过程、蛋白结合以及催化反应过程等有关,纤维黏连蛋白-1（FN1）和热休克蛋白1B（HSPA1B）是蛋白质相互作用网络的关键性节点。结论 不同剂量重离子照射诱导人淋巴细胞蛋白质组发生改变的机制不同,而且SZT2、FN1、HSPA1B蛋白质可能在重离子照射的损伤机制中发挥重要作用,有望成为重离子诱发辐射损伤的分子生物学标志。     

PLC/PIP2信号通路在辐射诱导NRP1+Treg 细胞中的作用机制

目的 观察X射线照射后小鼠胸腺细胞中CD4+ CD25+ NRP1+ Treg细胞数量及TGF-β1分泌量的变化,并探索PLC/ PIP2信号通路在其中的作用机制.方法 36只ICR小鼠按随机数字表法分为假照组、0.5、1.0、2.0、4.0和6.0 Gy的不同剂量组,X射线深部治疗机进行全身照射,于照射后16 h应用流式细胞仪分析小鼠胸腺细胞中CD4+ CD25+ NRP1+ Treg细胞的变化,ELISA法检测胸腺细胞TGF-β1含量的变化.EL-4细胞株经PKC激动剂(PMA)、Ca2+阻断剂(TMB-8)作用2h后并经4 GyX射线照射,于照射后48 h应用流式细胞术及ELISA法分别检测CD4+CD25+ NRP1+ Treg细胞及TGF-β1含量的变化.结果 小鼠胸腺细胞中NRP1+ Treg在0.5 GyX射线作用后稍有下降,于1.0 Gy降至最低(t=6.96,P＜0.01),而后呈剂量依赖性升高,于6.0 Gy升至最高(t =6.70,P＜0.01);胸腺细胞TGF-β1在0.5 GyX射线照射后显著下降(t=12.53,P＜0.01),而1.0～4.0 Gy照射后则呈剂量依赖性升高,于6.0 Gy仍保持高水平(t=10.40 ～ 15.30,P＜0.01).PMA作用后,与假照组相比,单独PMA组NRP1+ Treg细胞表达显著降低(t=3.06,P＜0.01),而联合照射后表达则明显上调(t=8.27,P＜0.01),TGF-β1无论受照与否,其含量均明显降低(t=10.46 ～39.69,P＜0.01);而TMB-8作用后,无论受照与否CD4+ CD25+ NRP1+ Treg的表达及TGF-β1的分泌量均显著上调(t=5.53～44.26,P＜0.01).结论 高剂量电离辐射可以诱导小鼠胸腺细胞中NRP1+ Treg细胞表达并增加TGF-β1的含量,此现象可能与启动PLC/PIP2信号通路有关.     

重组人蛋白C在CHO/dhfr+细胞中的表达与分析

目的 :人蛋白C具有重要的抗凝功能 ,与复发性血栓性疾病、蛋白C缺陷症、创伤等有重要关系。血源蛋白C成本高、工艺复杂且存在纯度、稳定性、安全性等问题 ,研制重组人蛋白C具有必要性。目前尚无此类产品上市。本研究拟从人肝细胞中克隆蛋白C的cDNA ,构建人蛋白C的哺乳动物细胞表达载体 ,实现重组人蛋白C在CHO dhfr 中的表达。方法 :用RT_PCR从人胎肝细胞mRNA中扩增人蛋白C的全长cDNA片段 ,将之克隆入pGEM_T载体并测序。目的片段插入真核表达载体pIRESneo以构建重组表达质粒。磷酸钙共沉淀法转染CHO dhfr 细胞 ,G4 18筛选抗性克隆。Western印迹法检测细胞培养上清。HitrapQ进行色谱纯化。表达产物经蛙蛇蛇毒激活后以APTT法测定抗凝活性。结果 :RT_PCR扩增到长 1386bp的DNA片段 ,序列与已报道的人蛋白C一致。所构建的表达质粒pIREShPC转染CHO dhfr 细胞 ,经G4 18加压筛选得到 7株表达细胞。Western印迹法检测发现表达产物能与抗人蛋白C单克隆抗体结合 ,相对分子质量与人蛋白C一致。HitrapQ纯化重组蛋白回收率 >6 0 %。表达产物抗凝活性略低于天然人蛋白C。     

不同强度微波辐射对小鼠脑组织钙,镁ATP酶活性的影响

目的 探讨微波对机体中枢神经系统作用的机理。方法 用２４５０ＭＨｚ连续波微波理疗机为辐射源,以昆明小鼠为对象,观察在１ｍＷ／ｃｍ＾２,５ｍＷ／ｃｍ＾２和１０ｍＷ／ｃｍ＾２三种照射强度下,小鼠脑皮层、海马及丘脑细胞膜Ｃａ＾２＋、Ｍｇ＾２＋－ＡＴＰ酶活性的变化情况,用组织化学方法测定其活性。结果 １ｍＷ／ｃｍ＾２时,皮层,海马及丘脑Ｃａ＾２＋、Ｍｇ＾２＋－ＡＴＰ酶活性均比对照组高（Ｐ〈０．０５）,５ｍ     

Fe3O4+5-Fu栓塞恶性肿瘤31例临床探讨

目的探讨Fe     

清热中药对大鼠体温调节中枢Na~+/ Ca~(2+)的影响

选用典型的清热中药黄芩、银花、连翘组成清热方,从体温调节中枢神经介质方面来探讨清热类中药的解热作用机制。实验结果表明降低体温调节中枢Na~+/Ca~(2+),从而抑制体温调定点上移是清热中药的解热作用机理之一。     

铜螯合纳米磁珠结合MALDI-TOF／TOF MS分析人尿液中多肽组分的方法初探

目的：利用铜螯合纳米磁珠（MB-IMAC-Cu^2＋）系统联合基质辅助激光解析电离-飞行时间质谱（MALDI-TOF／TOFMS）建立一套稳定、可行的技术路线,对尿液中相对分子质量（Mr）〈10000的多肽进行系统研究,包括从样品的采集、存放、提取、检测在内的各个步骤。方法：分析了8名健康男性和8名健康女性的尿液标本。针对样本采集、存放、不同提取方法以及实验整个系统稳定性的问题设计不同组,分别检测各组尿液多肽谱并对结果进行评价。结果：在本系统中,观察到健康人尿液Mr〈10000范围内平均有85个信号峰,不同性别组间尿液多肽谱未见明显差异。以MALDI-TOF／TOF检测得到的出峰情况来评价各种可能因素对实验体系的影响,铜螯合纳米磁珠（MB-IMAC-Cu^2＋）提取多肽效果比较满意;整个实验体系稳定、可靠,重复性好,选择其中所观察的10个峰,变异系数均在10％以内,具有良好的可操作性;室温或者4℃保存最好不超过12h;5次以内有限冻融对出峰没有影响。结论：本实验所探索、建立的方法为下一步研究尿液多肽组学提供了参考。     

放射损伤对鼻咽癌外周血CD4+CD25high调节性T细胞的影响

目的通过分析放疗前后鼻咽癌(NPC)患者外周血CD4+CD25high调节T(Tr)细胞比例及其变化规律.初步探讨NPC患者免疫抑制机制和放疗对免疫抑制的影响,为有效提高NPC的治疗疗效提供参考.方法采用流式细胞术检测36例初治的鼻咽癌患者放疗前、放疗后和30例正常健康者(对照组)外周血中T细胞亚群及CD4+CD25high T细胞比例.结果放疗前鼻咽癌患者CD3+、CD4+、CD8+T细胞比例及CD4/CD8比值接近正常对照组(P＞0.05);而CD4+CD25high Tr细胞比例明显高于正常对照组[分别为(2.76±1.06)%,(2.06±0.98)%,P＜0.05];放疗结束时,与放疗前比较,外周血CD4+T细胞比例减低、但差异无统计学意义(P＞0.05);CD4+/CD8+比值减低(P＜0.05),而CD4+CD25high Tr细胞比例明显升高,差异有统计学意义[(4.88±1.02)%,P＜0.05].结论CD4+CD25high Tr细胞可能是鼻咽癌患者免疫抑制的重要原因之一,与鼻咽癌免疫逃逸有关.放疗后外周血CD4+CD25high Tr细胞比例比CD4+/CD8+比值更能敏感反映免疫功能状态,有可能成为鼻咽癌的更有效的免疫监测指标.     

Recovery to +1Gz and +2Gz following +Gz-induced loss of consciousness: operational considerations

With the development of aircraft autorecovery technology, the need to understand the effects of potential inflight recovery profiles on human physiology has become important. Eight male volunteer subjects were exposed to +7Gz with an onset rate of 6 G.s-1 until they were unconscious. The subjects did not wear anti-G suits and did not perform anti-G straining maneuvers. The subjects controlled the centrifuge utilizing an F-16A stick, thereby deliberately self-inducing their unconsciousness. Following +Gz-induced loss of consciousness (G-LOC), recovery to the usual +1Gz level was compared to recovery to a +2Gz level by comparing absolute, relative, and total incapacitation times. The mean (+/- S.D.) absolute incapacitation time (period of unconsciousness) was 11.9 +/- 2.9 s for recovery to a +1Gz level and 12.9 S (+/- 6.9 S.D.) for recovery to a +2Gz level. The mean relative incapacitation time (period of confusion/disorientation) was 3.6 +/- 2.3 s for recovery to a +1Gz level as compared to 2.9 +/- 0.8 s for recovery to a +2Gz level. The total incapacitation time (sum of the absolute and relative incapacitation) was 15.6 +/- 2.7 s for recovery to a +1Gz level and 16.0 s (+/- 6.8 S.D.) for recovery to a +2Gz level. No significant differences in any of the incapacitation times were found when comparing recovery to +1Gz and +2Gz. The mean time from the onset of +Gz-stress to the onset of unconsciousness was approximately 7 s.(ABSTRACT TRUNCATED AT 250 WORDS)