氚照射生物效应的实验研究

综合概括了过去十几年所作的氚照射生物效应系统研究的实验结果。方法该研究着重于低剂量氚照射地健康造成可能影响的实验研究,研究了氚在妊娠和浦乳动物体内的分布、代谢和剂量估算;遗传学效应（初奶卵母细胞存活率、业原细胞存活率、卵母细胞或精母细胞的显性致死突变、精原细胞显性骨骼突变。通过Ｃ－分带Ｇｉｅｍｓａ染色,分析了精细胞细胞中期－１的染色体畸形）;致效应（生长发育、神经行为、脑细胞学和脑神经递质）,同时     

氚水和60Coγ线诱发小鼠显性致死突变相对生物效应的研究

侉订辐射防护标准的Q值,提供一些实验资料。本实验用LACA成年雌性小鼠按体重每克分别注射4.7,17.0,37.0,75.0和110.0微居里的氚水。估算了注射后10天内卵巢累积剂量分别为3.9,14.1,30.7,62.2,91.2拉德。诱发的显性致死突变数为0.46～2.46,剂量-效应之间呈直线关系,⁶⁰Coγ线横拟氚在卵巢中以指数下降的规律连续照射10天,每天照射22小时,累积剂量分别为52.6,71.18,108.22,161.87,194.25,269.88拉德,诱发的显性致死突变数为0.68～2.88,剂量-效应之间呈直线关系。根据上述实验结果测得氚的RBE值在本实验条件下为2.7l～2.85,平均为2.8。     

出生前注入氚水和γ射线照射诱发大鼠脑细胞缺失的相对生物效应研究

对两组妊娠11天的大鼠分别注入氚水(HTO)和以¹⁸⁷CsY射线连续照射, 以仔鼠出生后18天时大脑皮质锥体细胞数的变化为生物终点, 观察两种辐射的剂量效应曲线, 并将两者比较, 求出氚的RBE值。结果表明，在两种射线照射下，仔鼠大脑锥体细胞数皆随剂量增加而减少(P＜0.01).仔鼠受β和137Csγ射线照射,吸收剂量范围分别为0.012～1.32Gy,大脑锥体细胞缺失率Y与计量D均可拟合成对数直线回归方程,Y_β=27.1+8.3LgD和Y_p=18.5+13.9LgD.氚吸收剂量为1.7～0.17Gy时RBE值为3.4～8.5.     

125IUdR掺入B16黑色素瘤细胞DNA的内照射累积吸收剂量估算及RBE

本文以微核率为生物终点,以⁶⁰Coγ 射线为基准辐射,在研究了¹²⁵IUdR掺人动力学的基础上,对¹²⁵IudR掺入B₁₀黑色素瘤细胞DNA的内照射累积吸收剂量和RBE进行了估算,结果表明:¹²⁵IUdR掺入率分别和标记活度、标记时间呈线性正比关系,肿瘤细胞总微核率和微核细胞率均随¹²⁵IUdR掺入率增高而增高,回归方程分别为Y₁=0.0395+0.029X,Y₂=0.0776+0.021X,与⁶⁰Coγ 射线相比RBE分别为4.9和5。该研究为在常温下计算¹²⁵IUdR的RBE作了尝试。     

培养中的哺乳动物细胞的剂量率效应及其机制与意义

本文研究了培养中的小鼠L5178Y的白血病细胞以及它的辐射敏感的M₂。型突变株的γ线剂量率效应。选用的终点是细胞存活和抗6-硫代鸟嘌呤的突变。对MTO细胞存活没有观察到剂量率效应。虽然剂量率效应的确切机制还不清楚,但本文和其他资料表明,辐射损伤的修复与剂量率效应密切相关。用L5178Y细胞研究了包括HT0和有机氚化合物在内氚的细胞效应并与低剂量率Y线的效应作了比较。以细胞或细胞核的吸收剂量为基础时,除了[³H]、胸腺嘧窿核苷的效应比HTO和测试的[³H]-氯基酸高一倍外,发现有机氚的效应与HT0的相似。氚对低剂量率γ线的RBE值为1.5至3.0,这取决于检查的终点。本文提供了低剂量率γ线照射的初步结果,并加以讨论。     

碳离子放射治疗微剂量测量研究

目的 测量碳离子束的微剂量谱并计算其相对生物学效应（RBE）分布,为放射治疗微剂量研究提供参考。方法 使用绝缘体上硅（SOI）微剂量计对兰州重离子加速器国家实验室提供的260 MeV/u的¹²C离子束流进行微剂量谱测量,测量所得的脉冲幅度谱经转化得到剂量分布,通过摆放不同厚度聚甲基丙烯酸甲酯（PMMA）的组合,实现不同PMMA深度微剂量谱及RBE值的测量。结果 测量得到不同PMMA深度下260 MeV/u的¹²C离子束的微剂量谱,以及剂量线能y_D与RBE随PMMA深度的变化关系。PMMA深度为116.5 mm处,RBE值达到2.6的峰值,并在布拉格峰位后迅速下降,但在拖尾处RBE值仍有1.3约为坪区入口处的2倍。结论 本文为碳离子束微剂量谱提供基础数据,¹²C离子束的RBE值随着PMMA深度增加逐渐上升并达到峰值,布拉格峰位后迅速下降但在拖尾处的生物效应不可忽略。同时体现了不同线能区间处的导致的剂量份额,为评估重离子治疗中继发癌症的风险提供参考。     

人工智能识别60Co γ射线照射诱导人外周血微核的剂量-效应曲线建立

目的 根据扫描显微镜搭配玻片扫描软件(Metafer 4),在松弛素B(CB)阻断微核法试验中识别和鉴定微核,建立⁶⁰Co γ射线照射剂量与人外周血淋巴细胞微核率的剂量-效应曲线。方法 采集4名健康人(2男2女)肘静脉血样品,用0、0.25、0.5、1、2、3、4和5 Gy ⁶⁰Co γ射线(剂量率0.74 Gy/min)离体照射,胞质分裂阻断微核法培养、收获和制备标本玻片,人工智能彩色识别分析系统分析并记录双核细胞和微核数。应用CABAS 软件拟合基于微核率的剂量-效应曲线。2份照射后的盲样进行生物剂量估算验证。结果 在0~5 Gy 剂量范围内,拟合的微核剂量-效应曲线符合二次多项式模型,回归方程为y=0.0321D²+0.0237D+0.0127(R²=0.998,D为剂量)。用拟合曲线对验证样本的剂量估算结果与实际照射剂量基本接近。结论 成功建立基于人工智能识别微核的剂量-效应曲线,为估算辐射生物剂量提供了可行方法。     

60Co γ射线诱发小鼠外周血网织红细胞微核率的研究

目的 通过观察不同剂量⁶⁰Co γ射线照射后小鼠外周血网织红细胞微核率的变化,为使外周血网织红细胞微核成为探索快速高通量的生物剂量计提供科学依据。方法 ⁶⁰Co γ射线照射ICR小鼠,按不同照射剂量分为0、0.5、1、2、4和8 Gy组,眼球取血,流式细胞术(FCM)检测和显微镜观察小鼠外周血网织红细胞微核率的变化。结果 流式细胞术检测网织红细胞微核率随剂量增加逐渐增加,2 Gy达峰值,之后随剂量的增加而减少;显微镜观察的网织红细胞微核率变化趋势与流式细胞术检测结果基本一致。照射剂量在0~2 Gy剂量范围内,小鼠的外周血网织红细胞微核率的剂量-效应关系满足直线模型(R²=0.9063),并且2 Gy照射组与0 Gy组相比差异有统计学意义(t=-2.856,P<0.05)。结论 流式细胞术检测外周血网织红细胞微核率,在一定剂量范围内可成为早期快速、高通量的辐射损伤生物剂量计。     

低剂量率60Coγ线长期慢性照射和一次急性照射雄性小鼠诱发显性致死突变的研究

每天以2.02、3.84、7.68和13.03拉德γ线慢性照射雄性小白鼠,诱发的显性致死突变率均高于对照组。其中7.68和13.03拉德组的诱发率与累积剂量线性相关,分别为2.19×10^-4/拉德和2.63×10^-4/拉德。以114拉德/分剂量率一次照射小白鼠精子和精细胞的诱发率均与照射剂量呈线性相关,分别为0.75×10^-3/拉德和1.49×10^-3/拉德。慢性照射和急性照射精原细胞诱发的显性致死突变与累积剂量均无相关性。     

氚水内照射与60Coγ线外照射的比较毒理研究

本文比较研究了雄性小鼠接受氚水B线和⁶⁰Coγ线连续照射10天的累积剂量与精原细胞活存率的生物效应。氚B线的剂量为0, 0.05, 0.10, 0.16, 0.47和0.70Gy时, 精原细胞活存率为100～34%刚⁶⁰Coγ线的剂量为0, 0.43, 0.54, 1.06, 1.50, 2.04和2.58Gy时, 精原细胞活存率为10%～22%。     

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 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     

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.     

人体中的镭-226、镭-228、钋-210、铅-210

本文报道了广东阳江高本底地区6名、对照地区8名人尸体的骨²²⁶Ra、²²⁶Ra的浓度以及部分居民内脏器官中。²¹⁰Po、²¹⁰Pb的浓度。结果轰明阳江高本底地区和对照地区居民骨镭-226、镭-228的浓度分别为29.9pCi/kg, 26.9pCi/kgl 8.7pCi/kg, 8.2pCi/kg.由此估算出阳江高本底地区屠民骨中²²⁶Ra、²²⁸Ra的负薄璧及对骨衬、骨髓所产生的剂量当量分别为对照地区民民的3.4倍, 3.3倍。两地区居民内脏器官中^{210Po、210Pb的测定分析铡数较少但仍看出, 高本底地区均明显高于对照地区.}     

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).