α粒子和NNK联合作用的细胞毒性研究

目的研究α粒子和NNK联合作用的细胞毒性。方法指数生长期永生化的人支气管上皮细胞（BEP2D细胞）分为正常对照组（NC）、α粒子单纯照射组（α）、NNK染毒组（NNK）、NNK染毒（100μg／ml）后α粒子照射组（NNK＋α）和α粒子照射后NNK染毒（100μg／ml）组（α＋NNK）。用低密度接种细胞的克隆形成率测定细胞存活分数；用分子探针二氯荧光素双乙酸盐（DCFH—DA）和氢化乙啶（HE）检测细胞内活性氧（ROS）水平；通过测定培养液中乳酸脱氢酶（LDH）活性评价细胞膜通透性损伤。结果与相同剂量NNK或α粒子单独作用比较，α粒子和NNK联合作用BEP2D细胞的存活率明显下降，细胞内ROS水平和细胞培养液中LDH活性显著增高。扣除NNK效应后，α粒子和NNK联合作用BEP2D细胞的存活率明显低于α粒子单独照射组，而细胞内ROS水平和细胞培养液中LDH明显高于α粒子单独照射组。此外还发现α粒子照射后NNK染毒的细胞存活率明显低于NNK染毒后α粒子照射组。结论α粒子合并NNK的细胞毒作用具有协同性，且两者作用顺序不同对细胞存活率有影响。     

不同LET射线及其联合照射下淋巴母细胞微核率的剂量效应

目的 探讨在α粒子、γ射线以及联合照射下淋巴母细胞微核率的剂量效应.方法 以HMy2.CIR淋巴母细胞为对象,分别以不同剂量的α粒子和γ射线进行照射,以及先以0.025 ～0.500 Gy的α粒子照射后即刻以不同剂量的γ射线进行照射,用胞质分裂阻断法检测淋巴细胞微核,建立不同照射条件下淋巴母细胞微核率的剂量-效应曲线.结果 对于γ射线照射,微核率剂量-效应符合线性平方模型Y=c+αD+ βD2.对于α粒子照射,当照射剂量＜0.250 Gy时,细胞微核率随剂量的增加呈线性增加,当其剂量进一步增加时,微核率剂量-效应曲线呈现下弓型,可以采用反映辐射旁效应的BaD模型Y=c +αD +σ[1 -exp(-δD)]exp(-βD)进行很好地拟合.对于联合照射,当α粒子剂量较低时,微核率的剂量效应与γ射线照射时的相似;但当α粒子剂量较大时,微核率的剂量-效应更接近于α粒子照射.同时,0.2、0.5 Gyα粒子联合γ射线照射引起的微核率显著高于它们单独照射时的微核率之和(=5.22 ～ 11.86,P＜0.05).结论 α粒子照射具有与γ射线不同的辐射损伤规律,辐射旁效应可能在其中发挥了重要作用,而联合照射则可以引起细胞损伤的协同增强.     

α—粒子诱发BEP2D2细胞癌变系的DNA断裂重接修复缺陷与XRCCs修复基因mRNA表达研究

目的 研究α粒子诱发人支气管上皮细胞（BEP2D）癌变细胞系BERP35T－1和BERP35T－4的DNA断裂损伤修复能力，分析其DNA断裂修复基因XRCCs系列的mRNA表达。方法 脉冲电场凝胶电泳法检测DNA双链断裂，RT－PCR分析DNA修复基因的mRNA表达。结果 恶笥转化细胞系BERP35T－1和BERP35T－4受0－150Gy γ射线照射后修复4h的DNA断裂残留损伤显著高于亲本BEP2D细胞，mRNA表达分析显示修复基因XRCC2，XRCC3和Ku80(XRCC5)表达下调2.5-6.5倍，而BERP355－R细胞中DNA－PKcs(XRCC7)表达上调2．4倍。结论 α粒子诱发恶性转化细胞系的DNA链断裂修复机理缺陷，其中部分原因是DNA修复基因的表达抑制。DNA修复缺陷将导致细胞基因组不稳定性，α粒子诱发细胞恶性转化机理可能与此相关。     

α粒子诱发BEP2D细胞恶性转化中脂质和DNA氧化损伤的研究

目的 探讨α粒子诱发永生化人支气管上皮细胞BEP2D恶性转化的机制.方法 运用DCFH-DA荧光探针标记活性氧(ROS),观察分析BEP2D细胞、α粒子作用BEP2D后第22代细胞RH22,以及α粒子作用BEP2D后恶性转化细胞株BERP35T-１内基础活性氧水平.丙二醛(MDA)测定试剂盒检测BEP2D、RH22和BERP35T-1细胞内脂质过氧化产物丙二醛的含量.采用免疫细胞化学法和免疫荧光染色法,检测BEP2D、α粒子作用BEP2D后第23代细胞RH23及BERP35T-1细胞内DNA氧化损伤产物8-OH-dG和DNA双链断裂产物γ-H2AX的表达水平.结果 与BEP2D细胞相比,RH22和BERP35T-1细胞中基础活性氧水平显著升高(t=4.30和3.94,P＜0.05),丙二醛的含量显著升高(t=4.89和15.10,P＜0.05);RH23和BERP35T-1细胞中8-OH-dG表达上调(t=3.80和2.92,P＜0.05),γ-H2AX表达上调(t=7.61和12.67,P＜0.05).结论 氧化还原环境紊乱形成氧化压力,导致细胞内脂质和DNA氧化损伤增强,由此促进基因组不稳定性,可能是α粒子诱发BEP2D细胞恶性转化的机制之一.     

低剂量辐射对环磷酰胺所致DNA损伤的影响

目的研究低剂量γ射线预照射对大剂量环磷酰胺化疗所致外周血淋巴细胞DNA损伤及遗传物质损伤的影响。方法昆明种雄性小鼠随机分为空白对照组、荷瘤对照组（假照组）、荷瘤低剂量照射组（LDR组）、荷瘤环磷酰胺化疗组（CTX组）和荷瘤低剂量照射联合化疗组（LDR＋CTX组）。常规饲养1周后，于左腹股沟皮下各接种S180肉瘤细胞（空白对照组除外），接种后第8和11天对LDR组和LDR＋CTX组小鼠给予75mGy-γ射线全身照射，照射后30h分别给予CTX组和LDR＋CTX组小鼠腹腔注射环磷酰胺3．0mg；第13天处死所有小鼠，分别取血，采用单细胞凝胶电泳法检测外周血淋巴细胞DNA损伤；采用骨髓嗜多染红细胞微核率（MNF）检测遗传物质损伤。结果①环磷酰胺化疗后DNA损伤程度较空白对照及荷瘤对照组均显著增加；环磷酰胺化疗前给予75mGy-γ射线照射，则可显著降低大剂量环磷酰胺化疗所致的DNA损伤。②大剂量环磷酰胺化疗后小鼠骨髓嗜多染红细胞微核率较空白对照组及单纯荷瘤组有显著增加（P〈0．01）；环磷酰胺化疗前给予75mGy-γ射线照射则可降低环磷酰胺所致微核率的增加，但差异无统计学意义（P〉0．05）。结论①大剂量环磷酰胺化疗可引起外周血淋巴细胞DNA损伤；化疗前给予75mGy-γ射线照射对DNA损伤可能产生一定的保护作用。②环磷酰胺有强大的致突变作用，可导致骨髓嗜多染红细胞微核率显著增加，75mGy-γ射线预照射对大剂量环磷酰胺化疗的遗传学毒性未表现出明显的保护作用。     

α粒子诱发转化人支气管上皮细胞BEP2D中p53基因的突变特点

目的 观察α粒子诱发BEP2D细胞转化过程中p53基因的改变。方法 聚合酶链式反应－单链构象多态性分析（PCR－SSCP）。结果 分析发现在细胞转化过程中,p53基因发生重要改变,照射后早期传代细胞中,p53外显子7就发生碱基突变,经酶切分析为249密码子的改变,外显子5／6在照后20代细胞内开始丢失,并经Southern杂交证实,以上改变均在转化过程中持续存在;而外显子8／9未见变化。结论p53基因外显子5、6、7是α粒子对DNA损伤的重要靶位点,在α粒子诱发支气管上皮细胞转化的过程中发挥重要作用。     

α-粒子诱发BEP2D细胞癌变系的DNA断裂重接修复缺陷与XRCCs修复基因mRNA表达研究

目的 研究α粒子诱发人支气管上皮细胞(BEP2D)癌变细胞系BERP35T-1和BERP35T-4的DNA断裂损伤修复能力,分析其DNA断裂修复基因XRCCs系列的mRNA表达。方法 脉冲电场凝胶电泳法检测DNA双链断裂,RT-PCR分析DNA修复基因的mRNA表达。结果 恶性转化细胞系BERP35T-1和BERP35T-4受0～150Gyγ射线照射后修复4h的DNA断裂残留损伤显着高于亲本BEP2D细胞,mRNA表达分析显示修复基因XRCC2、XRCC3和Ku80(XRCC5)表达下调2.5～6.5倍,而BERP35T4细胞中DNAPKcs(XRCC7)表达上调2.4倍。结论 α粒子诱发恶性转化细胞系的DNA链断裂修复机理缺陷,其中部分原因是DNA修复基因的表达抑制。DNA修复缺陷将导致细胞基因组不稳定性,α粒子诱发细胞恶性转化机理可能与此相关。     

α粒子诱发BEP2D细胞恶性转化中抗氧化能力和辐射敏感性研究

目的 研究α粒子诱发人支气管上皮细胞BEP2D恶性转化中细胞的抗氧化能力和辐射敏感性变化.方法 运用谷胱甘肽过氧化物酶(GPX)、过氧化氢酶(CAT)和谷胱甘肽(GSH)试剂盒分别检测永生化人支气管上皮细胞BEP2D、α粒子作用BEP2D后第21代细胞RH21和α粒子作用BEP2D细胞后形成的恶性转化细胞BERP35T-1内抗氧化酶GPX和CAT的活性以及抗氧化剂GSH的含量;四甲基偶氮唑盐比色(MTT)法检测0、30、60、90、120和150 μmol/L H2O2作用BEP2D、RH21和BERP35T-1细胞96 h后,细胞增殖率的差异;0、2、4和8 Gy γ射线照射BEP2D、RH21和BERP35T-1细胞7～9 d后,用细胞克隆计数和MTT法检测细胞增殖率和存活分数的变化.结果 RH21和BERP35T-1细胞中GPX酶活力均低于BEP2D细胞(t=5.75和7.65,P＜0.05).BEP2D细胞中CAT酶活力是RH21细胞的2.64倍,是BERP35T-1细胞的5.76倍.RH21细胞中GSH含量与BEP2D细胞比较,差异无统计学意义;恶性转化细胞BERP35T-1内GSH含量则明显低于BEP2D细胞(t=7.76,P＜0.05).与BEP2D细胞相比,60、90、120和150 μmol/L H2O2作用后RH21细胞的增殖率降低(t=29.90～84.68,P＜0.01),30、60、90、120和150 μmol/L H2O2作用后BERP35T-1细胞的增殖率降低(t=10.37～58.36,P＜0.01).4和8 Gy γ射线照射后,RH21细胞的增殖率和存活分数均显著低于BEP2D细胞(t=6.33～45.00,P＜0.05);2、4和8 Gy γ射线照射后,BERP35T-1细胞的增殖率和存活分数较BEP2D细胞明显降低(t=5.87～34.17,P＜0.05).结论 α粒子诱发人支气管上皮细胞BEP2D恶性转化过程中,细胞的抗氧化能力降低、辐射敏感性增强.抗氧化系统功能减弱可能是α粒子诱发BEP2D细胞恶性转化和辐射敏感性增强的机制之一.

Abstract：

Objective To investigate the antioxidant ability and radiosensitivity in the malignant transformed human bronchial epithelial cell line BEP2D induced by α-particle exposure.Methods Glutathione Peroxidase (GPX),Catalase (CAT) and Glutathione (GSH) assay kits were employed to detect GPX and CAT enzyme abilities and the levels of GSH in BEP2D,RH21 ( passage 21 of α-particle-irradiated BEP2D cells),and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from cells of passage 35 of α-particle-irradiated BEP2D cells).MTT assay were used to test the growth rate of BEP2D,RH21 and BERP35T-1 cells treated with 0,30,60,90,120,and 150 μmoL/L H2O2.Colony-forming test and MTT assay were used to examine the cell survival fraction and the growth rate of BEP2D,RH21 and BERP35T-1 cells exposed to 0,2,4,and 8 Gy of γ-rays,respectively.Results GPX and CAT enzyme activities in RH21 and BERP35T-1 cells were obviously lower than in BEP2D( t = 5.75-67.92 ,P ＜ 0.05 ).CAT enzyme activity in BERP35T-1 was lower than that in RH21 cells (t =22.25 ,P ＜0.01 ).Compared to BEP2D cells,decreased level of GSH was detected in BERP35T-1 cells(t = 7.76,P ＜ 0.05 ),but there was no change in RH21.After treatment with 30,60,90,120,and 150 μmol/L H2O2,the growth rates of BEP2D were all higher than those of BERP35T-1 cells(t = 10.37-58.36,P ＜0.01 ).Meanwhile,the growth rates of BEP2D were all higher than those of RH21 cells after treatment with 60,90,120,and 150 μ mol/L H2O2 (t = 29.90-84.68,P ＜ 0.01 ).In addition,compared to BEP2D cells,decreased cell survival fraction and growth rate of BERP35T-1 cells were observed after irradiation with 2,4,and 8 Gy of y-rays ( t = 5.87-34.17,P ＜ 0.05 ).The cell survival fraction and growth rate of RH21 were all lower than those of BEP2D cells at 4 and 8 Gy post-irradition( t =6.33- 45.00,P ＜ 0.05 ).Conclusion The function of antioxidant system decreased in the α-particleinduced transformed cells,which could contribute to the acceleration of cellular malignant transforming process and radiosensitivity.     

α辐射诱发人胚肺细胞转化及DNA链断裂

目的 探索α辐射所致DNA链断裂损伤与辐射致癌之间的定量关系。方法 用缺口翻译技术检测DNA链断裂,用软琼脂克隆形成率评价细胞转化。结果 0.25-5Gyα粒子照射后的人胚肺细胞,DNA链断裂损伤和半固体琼脂培养集落形成率均明显增加,并显示出良好的剂量效应关系。进一步分析表明,各受照射组细胞DNA链断裂与细胞转化率之间存在着显著的正相关。结论 α辐射致癌与辐射致细胞DNA链断裂损伤密切相关。     

低强度微波与4-硝基喹啉氧化物对人淋巴细胞DNA损伤的研究

目的　研究低强度 2 4 5 0MHz微波 (5 0mW cm2 )与 4 硝基喹啉氧化物 (4 NQO)对人淋巴细胞DNA损伤效应的联合作用。方法　采用彗星试验来检测人外周血淋巴细胞经微波与 4 NQO联合作用后的DNA损伤情况。微波与 4 NQO联合暴露方式有 3种 :微波辐射后 4 NQO染毒、微波与4 NQO同时暴露、4 NQO染毒后微波辐射。结果　微波辐射组的DNA损伤指标 (彗星形状和彗星全长 )与对照组比较 ,差异无显著性 (P >0 0 5 )。微波照射后 4 NQO染毒组中 ,5 0 ,2 5 μmol L剂量的DNA损伤指标与相应 4 NQO组比较差异均有显著性 (P <0 0 5或P <0 0 1)。微波与 4 NQO同时暴露组或 4 NQO染毒后微波照射组与相应 4 NQO组比较差异无显著性 (P >0 0 5 )。结论　低强度 2 4 5 0MHz微波不能诱发DNA损伤 ,当微波辐射先于 4 NQO暴露时 ,微波能增强 4 NQO诱发的DNA损伤效应。     

The acutely limping child

Acute limping may be the result of multiple pathologies in children. The differential diagnosis varies based on the age of the child. Irrespective of age, the initial imaging work-up includes AP and frog leg radiographs of the pelvis and ultrasound; MRI may sometimes be helpful. In children less than 3 years, infections and trauma are most frequent. MRI is the imaging modality of choice when osteomyelitis is clinically suspected. Between the ages of 3 and 10 years, transient synovitis of the hip and Legg-Calvé-Perthes disease are main considerations but infection, inflammation and focal bony lesions are also considered. In children over 10 years, slipped capital femoral epiphysis also is considered.     

The role of interventional radiology in trauma

Introduction Interventional Radiology has evolved into a specialty having enormous input into the care of the traumatized patient.In all hospitals,regardless of size,the Interventional Radiologist must consider their relationships with the trauma service in order to     

Do Balance Board Training Programs Reduce the Risk of Ankle Sprains in Athletes?

Introduction Ankle sprains are the most common musculo-skeletal injury that occurs in athletes,particularly in sports that require jumping and landing on one foot such as soccer,and basketball(1-4).These injuries often result in significant time loss from participation,long-term disability,and have a major impact on health care costs and resources(5-8).     

Carbohydrate Supplementation during Exercise: Does It Help? How Much is Too Much?

KEY POINTS· Carbohydrate intake during exercise can delay the onset of fatigue and improve performance of prolonged exercise as well as exercise of shorter duration and greater intensity (e.g., continuous exercise lasting about 1h and intermittent high-intensity exercise), but the mechanisms by which performance is improved are different.     

Diagnóstico ecográfico del neumotórax

The ultrasonographic diagnosis of pneumothorax is based on the analysis of artifacts. It is possible to confirm or rule out pneumothorax by combining the following signs: lung sliding, the A and B lines, and the lung point. One fundamental advantage of lung ultrasonography is its easy access in any critical situation, especially in patients in the intensive care unit. For this reason, chest ultrasonography can be used as an alternative to plain-film X-rays and computed tomography in critical patients and in patients with normal plain films in whom pneumothorax is strongly suspected, as well as to evaluate the extent of the pneumothorax and monitor its evolution.     

High Intensity Interval Training:New Insights

KEY POINTS ·High-intensity interval training(HIT)is characterized by repeated sessions of relatively brief，intermittent exercise.often performed with an“a11 out”effort or at an intensity close to that which elicits peak oxygen uptake(i.e.，≥90%of VO2 peak).     

磁共振DWI和动态增强鉴别颅底脊索瘤和侵袭性垂体瘤的应用

目的 探讨磁共振扩散加权成像(DWI)和动态增强在颅底脊索瘤和侵袭性垂体瘤(IPA)鉴别诊断中的应用价值.方法 搜集经手术病理证实且影像学有鞍区破坏的颅底脊索瘤患者15例、向鼻咽部侵犯的IPA患者20例.测量二者的表观扩散系数(ADC)值,绘制受试者工作特征曲线(ROC),分析动态增强曲线的类型,统计达峰时间(TTP)、增强峰值(EP)和最大对比增强率(MCER),分析各个参数在鉴别诊断中的价值.结果 颅底脊索瘤的ADC值为(1.274±0.07)×10-3mm2/s,高于IPA ADC值(0.672±0.03) ×10-3 mm2/s(P ＜0.001),ADC阈值为0.964×10-3mm2/s时,ROC曲线下面积为0.997,敏感度为93.3％,特异度为100％.颅底脊索瘤时间-信号强度曲线(TIC)Ⅰ型14例,TICⅢ型1例,此例TICⅢ型者TTP约40 s;IPA TIC Ⅰ型7例,TICⅢ型13例.颅底脊索瘤和IPA的EP、MCER差异均有统计学意义(P ＜0.001).结论 ADC值和TIC的类型及其相关参数(EP,MCER)有助于颅底脊索瘤和IPA之间的鉴别.     

Knee injury and Osteoarthritis Outcome Score (KOOS) - validation of a Swedish version

The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered instrument measuring outcome after knee injury at impairment, disability, and handicap level in five subscales. Reliability, validity, and responsiveness of a Swedish version was assessed in 142 patients who underwent arthroscopy because of injury to the menisci, anterior cruciate ligament, or cartilage of the knee. The clinimetric properties were found to be good and comparable to the American version of the KOOS. Comparison to the Short Form-36 and the Lysholm knee scoring scale revealed expected correlations and construct validity. Item by item, symptoms and functional limitations were compared between diagnostic groups. High responsiveness was found three months after arthroscopic partial meniscectomy for all subscales but Activities of Daily Living.