辐射体外诱发细胞恶性转化的研究

本文总结了X射线(180kV)、⁶⁰Coγ射线和²³⁸Puα粒子(5.25MeV)以及Y射线甲基气胆蒽(3-MCA)复合处理分别污发成年Wistar大鼠肺成纤维细胞系(WAL-F₁)于正常人胚肺细袍系(HEL-8315)恶性转化的研究结果。     

喹胺酸和LICAM(C)对大鼠体内238Pu和241Am的促排效果比较

喹胺酸(Quinamic acid, QAA, 811)是一种异哇啉类络合剂, 对钍有较好的促排效果。本文主要研究大鼠静脉注入(iv)²³⁸Pu和²⁴¹Am各26kBq/kg后1小时, 经皮下注入(so)不同剂量.(1～30μmol/kg)QAA, 或静脉注入核素后立即灌胃(po)QAA(30μmol/kg)对²³⁸Pu、²⁴¹Am的促排疗效, 并与LICAM(C)相比较。实验观察到QAA对降低骨肝中²³⁸Pu、²⁴¹Am的蓄积量有较好的作用, QAA对²³⁸Pu的促排效果高于对²⁴¹Am.在剂量(1～30μgmol/kg)对肝、肾中²³⁸Pu和骨、肾中²⁴¹Am蓄积量的降低, QAA优于LICAM(C)；灌胃QAA(30μttmol/kg)伍用NaHCO₃(5mmol/kg的)疗效, 对骨、肝中²³⁸Pu蓄积量的降低, QAA和LICAM(C)二间无差异(P>0.05), 但对²³⁸Pu在肾中蓄积量和对²⁴¹Am在骨, 肾中蓄积量的降低, QAA明显优于LICAM(C)。     

基于蒙特卡罗模拟的9 C重离子衰变产物对细胞损伤的分析

目的 探究⁹C重离子治疗中因自身衰变产生的缓发粒子对细胞产生的辐射损伤和在单个V79中国仓鼠肺细胞模型上的微观剂量以及引起的生物学效应。方法 采用蒙特卡罗程序模拟多种能量(3~10 MeV)α粒子在细胞(细胞半径R_C=10 μm,细胞核半径R_N=5 μm)中的输运后细胞核内吸收剂量结果,并与医学内照射剂量(MIRD)方法S值(S_N←N,S_N←Cy,S_N←CS)进行比较,证明该方法的可行性,最后使用蒙特卡罗方法模拟计算⁹C重离子分别在V79细胞模型表面、细胞质内以及细胞核3种位置处衰变生成的缓发粒子(α粒子和质子)在靶中输运能量沉积情况及细胞生存率。结果 蒙特卡罗模拟结果与MIRD方法S值进行比较,靶源组合从细胞核到细胞核S_N←N值的差异为1.91%~4.95%,细胞质到细胞核S_N←Cy为1.48%~5.11%,细胞表面到细胞核S_N←CS差异为-1.99%~0.80%,证明蒙特卡罗计算值与MIRD方法S值吻合较好(差异值均< 6%)。当一个⁹C离子在V79细胞模型表面衰变产生次级粒子进入细胞,细胞核内平均吸收剂量为10^-2Gy数量级,计算细胞生存率约为88%;衰变在细胞质中进行,计算细胞生存率约为80%;当碳离子直接进入细胞核中衰变,α粒子射程短并将大部分能量沉积在细胞中(细胞核内平均剂量0.1 Gy数量级),造成细胞损伤较大,细胞存活的概率约为53%。结论 ⁹C离子自身衰变发射次级带电粒子,其中α粒子进入细胞核时对细胞造成的损伤较大,生物学效应明显。     

238Puα粒子体外诱发人胚肺细胞癌变的膜脂流动性特性

本研究采用DpH探剂标记法、荧光分光光度计测定细胞膜脂流动性做为诊断恶性肿瘤的标志。人胚肺细胞癌变取决于²³⁸Puα粒子的照射剂量；在0.5Gy照射后人胚肺细胞开始发生癌变。癌变细胞的微粘度较正常人胚肺纽胞低； 微粘度低者,流动性则高,反之亦然。结果表明：人胚肺受0.5、1.0Gy照射后其流动性分别为16.335±0.017,38.254±0.257.其中受1.0Gy照后的流动性与正常人胚肺细胞比较,差异有非常显着性(p相似文献   

吸入239PuO2对肺损伤效应的研究

本研究选用了806只Wistar大鼠(实验组584只,对照组222只)观察了吸入²³⁹PuO₂(初始肺负荷O.38～12.6kBq,AMADl.1～1.4μm,o_gl.9)后在呼吸道中的沉积与廓清规律,²³⁹PuO₂所致肺癌的量效关系及其组织学特征； 肺巨噬细胚(PAM).肺天然杀伤细胞(NK)及肺泡I型细胞(AT-I)在α粒子作用下功能与形状学改变。结果表明；大鼠终生肺癌的危险度岁,2162/10⁶火鼠·cGy,芏332例8种类型肺癌中以腺癌、鳞癌为主,同时观察到一例胸淋巴结的原发性血管肉瘤。PAM核受到1.0Gy照射后,细胞增殖功能受抑,非特异吞噬功能降低约需大于2.2Gy.在初始肺负荷量4.O～12.9kBq时,NK细胞对YAC-1肿瘤细胞的杀伤活力有下降趋势。通过微剂量学、体视学的研究,证实AT-I细胞可能是α粒子诱发肺癌的靶细胞之一,在初始肺负荷量为250～733Bq时,即可观察到细胞分化程度的下降。文中还对²³⁹PuO₂诱发人肺癌的危险度进行了讨论。     

125I粒子组织间永久种植致大鼠坐骨神经早期损伤的病理学观察

目的 探讨¹²⁵I粒子持续性低剂量率照射下肿瘤细胞的凋亡和周期改变。方法 采用CL187人结肠癌细胞系体外培养,分为空白对照组、⁶⁰Co单次高剂量率照射组、¹²⁵I低剂量率照射组。单次高剂量率组以2 Gy/min给予细胞1、2、4、6、8和10 Gy的照射,低剂量率组以2.77cGy/h的初始剂量率给予相同剂量照射,照射后24 h根据肿瘤细胞死亡率和14 d克隆形成率评价不同照射方式对肿瘤细胞的杀伤效果。同时,用放射性¹²⁵I粒子以2.77 cGy/h的剂量率,给予细胞2、5和10 Gy的照射,应用流式细胞术测量其凋亡和细胞周期的变化。结果 低剂量率组照射后细胞死亡率在1 Gy时低于⁶⁰Co单次高剂量率组,随着剂量的上升,2 Gy后,超过单次高剂量率组,但整体上¹²⁵I粒子照射后细胞死亡率高于⁶⁰Co组(P=0.011)。¹²⁵I持续性低剂量率照射组的克隆增殖率明显低于⁶⁰Co单次高剂量率组(P=0.0021)。低剂量率照射下,2 Gy时仅能引起G₂/M期阻滞和凋亡,5 Gy时达到峰值,10 Gy时细胞周期阻滞和凋亡的比率依然很高,但相对于5 Gy有所下降;同时G₂/M期阻滞和凋亡变化呈现出相同的趋势。结论 在相同剂量条件下,¹²⁵I粒子持续照射低剂量率照射比⁶⁰Co单次高剂量照射对CL187肿瘤细胞具有更强的杀伤效应;G₂/M期阻滞引起的凋亡是低剂量率照射杀伤肿瘤细胞的主要机制。     

电离辐射致K562细胞旁效应的实验研究

目的 研究⁶⁰Co γ线不同剂量照射条件培养液(ICM)培养K₅₆₂细胞后引发的旁效应。方法 采用健康男性外周血自然杀伤(NK)细胞,观察不同剂量⁶⁰Co γ线照射的条件培养液培养后引发的K₅₆₂细胞对NK细胞敏感性的改变,同时用流式细胞仪检测K₅₆₂细胞的凋亡情况。结果 照射组NK细胞活性显著增加,即受照肿瘤细胞的培养基显著影响了未受照肿瘤细胞的存活能力,从而NK细胞对未照射细胞的活性显著增加;其中,从0.5 Gy起即出现显著升高, 1.0 Gy继续增加,2.0和5.0 Gy出现波动,在8.5 Gy达到最高。照射组K₅₆₂细胞的凋亡率比对照组显著增加(P<0.01),即受照肿瘤细胞的培养基显著影响了未受照肿瘤细胞的存活能力。在0.5 Gy处,即出现非常明显的效应。结论 对于K₅₆₂细胞,ICM对细胞显示出明显损伤作用,NK细胞活性显著增加,凋亡率升高。提示存在培养基转移介导的电离辐射旁效应。     

大鼠肺巨噬细胞对X线的辐射敏感性

以大鼠肺臣噬细胞的³H-TdR标记细胞百分比(简称标记细胞百分比)和分裂细胞百分比为生物指标,观察了大鼠肺巨噬细胞对x线的辐射敏感性。胸部接受x线照射后2天洗肺获取的细胞,其辐射敏感性参数,标记细胞(%):D_o=1.02G)r,Dq=0.12Gy,n=1.12; 分裂细胞(%):D_o=0.68Gy,Dq=0.06Gy,n=1.1.胸部接受x线照射后立即获取的细胞辐射敏感性参数,标记细胞(%):D_o=3.56Gy,Dq=0.77Gy,n:1.24.分裂细胞(%):D_o=3.69Gy,Dq=0.35Gy,n=1.1.从上述结果看出,照后2天的肺巨噬细胞增殖受抑制的效立比照看立即出现的效应重些。文内对这两批实验结果进行了扼要的讨论。     

低剂量率裂变中子照射对大鼠外周血淋巴细胞亚群的影响

目的 探讨低剂量率中子长期照射对大鼠外周血细胞亚群的影响。方法 96只雄性大鼠分为对照组和照射组,照射组每天用低剂量率中子²⁵²Cf(吸收剂量率为0.35 mGy/h)照射20.5h,在照射的第14、28、42、56和70天(累积剂量分别为0.1、0.2、0.3、0.4和0.5 Gy)及停止照射后第35天各取8只大鼠,用血细胞计数仪检测大鼠外周血WBC、用流式细胞仪检测外周血CD4⁺CD3⁺、 CD8⁺CD3⁺、CD45RA⁺/CD161α⁺亚群的变化。结果 累积剂量为0.3、0.4及0.5 Gy时WBC明显低于对照组(P<0.05),停止照射后35 d,WBC显著低于对照组(P<0.01);累积剂量为0.1、0.3、0.4、0.5 Gy及停止照射后35 d,外周血CD4⁺CD3^-细胞比例显著高于对照组(P<0.01或<0.05);累积剂量为0.2和0.3 Gy时CD8⁺CD3^-细胞比例显著高于对照组(P<0.05或P<0.01)。而累积剂量为0.1 Gy时的CD4⁺CD3⁺细胞比例及0.1和0.2 Gy时的CD8⁺CD3⁺细胞比例明显高于同一天对照组(P<0.01或<0.05)。另外,低剂量率中子长期照射可使累积剂量为0.2~0.3 Gy的外周血NK细胞(CD161α⁺ CD45RA^-)显著升高,累积剂量为0.1~0.5 Gy及停止照射后35 d照射组的外周血B细胞(CD161α^- CD45RA⁺)比例明显下降。结论 低剂量率裂变中子长期照射可使外周血淋巴细胞TCR基因突变,使大鼠外周血WBC减少,淋巴细胞中B细胞减少,NK细胞细胞比例升高,这种变化在停止照射后一段时间仍可能难以恢复。     

EGFR抑制剂C225对人前列腺癌细胞的放射增敏作用

目的 探讨表皮生长因子抑制剂C225对人前列腺癌细胞株(DU145) 放射敏感性的影响。方法 实验组用表皮生长因子抑制剂C225(100 nmol/L)处理后,⁶⁰Co γ射线(吸收剂量率1.953 Gy/min)对体外培养的DU145细胞进行0、2、4、6 和8 Gy 照射,用MTT法、集落形成法检测细胞增殖和细胞存活率;用单击多靶模型拟合剂量存活曲线;用流式细胞仪检测细胞周期和凋亡。结果 C225对照射后DU145细胞增殖有明显抑制作用。C225组的放射生物学参数值(D₀、D_q、N、SF₂)较对照组低。C225组和对照组的RBE 比值为1.39。C225组处于S期的细胞比例降低,出现明显的G₀/G₁期阻滞。C225组细胞的早期凋亡率在照射剂量达4 Gy后明显高于对照组(t=-14.55,P＜0.05)。结论 表皮生长因子抑制剂C225通过抑制细胞增殖、G₀/G₁ 期阻滞和诱导凋亡来增加人前列腺癌细胞放射敏感性。     

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.     

Endovascular management of carotid-cavernous fistulas

Objective To investigate endovascular treatment of traumatic direct carotid-cavernous fistulas （CCF） and their complications such as pseudoaneurysms. Methods： Over a five-year period, 22 patients with traumatic direct CCFs were treated endovascularly in our institution. Thirteen patients were treated once with the result of CCF occluded, 8 twice and 1 three times. Treatment modalities included balloon occlusion of the CCF, sacrifice of the ipsilateral internal carotid artery with detachable balloon, coll embolization of the cavernous sinus and secondary pseudoaneurysms, and covered-stem management of the pseudoaneurysms. Results All the direct CCFs were successfully managed endovascularly. Four patients developed a pseudoaneurysm after the occlusion of the CCF with an incidence of pseudoaneurysm formation of 18.2% （4/22）. A total number of 8 patients experienced permanent occlusion of the ICA with a rate of ICA occlusion reaching 36.4% （8/22）. Followed up through telephone consultation from 6 months to 5 years, all did well with no recurrence of CCF symptoms and signs. Conclusion Traumatic direct CCFs can be successfully managed with endovascular means. The pseudoaneurysms secondary to the occlusion of the CCFs can be occluded with stent-assisted coiling and implantation of covered stents.     

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.     

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).     

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).     

Developmental validation of the PowerPlex(®) ESI 16 and PowerPlex(®) ESI 17 Systems: STR multiplexes for the new European standard

In response to the ENFSI and EDNAP groups’ call for new STR multiplexes for Europe, Promega^® developed a suite of four new DNA profiling kits. This paper describes the developmental validation study performed on the PowerPlex^® ESI 16 (European Standard Investigator 16) and the PowerPlex^® ESI 17 Systems. The PowerPlex^® ESI 16 System combines the 11 loci compatible with the UK National DNA Database^®, contained within the AmpFlSTR^® SGM Plus^® PCR Amplification Kit, with five additional loci: D2S441, D10S1248, D22S1045, D1S1656 and D12S391. The multiplex was designed to reduce the amplicon size of the loci found in the AmpFlSTR^® SGM Plus^® kit. This design facilitates increased robustness and amplification success for the loci used in the national DNA databases created in many countries, when analyzing degraded DNA samples. The PowerPlex^® ESI 17 System amplifies the same loci as the PowerPlex^® ESI 16 System, but with the addition of a primer pair for the SE33 locus. Tests were designed to address the developmental validation guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM), and those of the DNA Advisory Board (DAB). Samples processed include DNA mixtures, PCR reactions spiked with inhibitors, a sensitivity series, and 306 United Kingdom donor samples to determine concordance with data generated with the AmpFlSTR^® SGM Plus^® kit. Allele frequencies from 242 white Caucasian samples collected in the United Kingdom are also presented. The PowerPlex^® ESI 16 and ESI 17 Systems are robust and sensitive tools, suitable for the analysis of forensic DNA samples. Full profiles were routinely observed with 62.5 pg of a fully heterozygous single source DNA template. This high level of sensitivity was found to impact on mixture analyses, where 54–86% of unique minor contributor alleles were routinely observed in a 1:19 mixture ratio. Improved sensitivity combined with the robustness afforded by smaller amplicons has substantially improved the quantity of data obtained from degraded samples, and the improved chemistry confers exceptional tolerance to high levels of laboratory prepared inhibitors.