硼中子俘获疗法诱导SHG44胶质瘤细胞凋亡

目的 探讨硼中子俘获疗法(BNCT)是否抑制人脑胶质瘤细胞SHG44增殖及其作用机制。方法 BNCT作用后,应用四甲基偶氮唑蓝比色法检测SHG44细胞的增殖抑制,采用光镜、电镜、荧光显微镜观察细胞的形态学变化。应用流式细胞仪检测SHG44细胞的凋亡率,以Western blot检测细胞表达Bcl-2、Bax蛋白的变化。结果 BNCT对SHG44细胞的增殖抑制作用呈剂量依赖性。BNCT 4和8 Gy后48 h流式细胞仪检测凋亡率分别为63.2%和88.3%。BNCT作用后,Bax蛋白表达增高,Bcl-2蛋白表达下降。结论 BNCT对胶质瘤细胞SHG44具有明显的增殖抑制及诱导凋亡作用,并使Bax蛋白表达上调、Bcl-2蛋白表达下调。     

辐射对恶性脑胶质瘤细胞放射敏感性的影响及其机制

目的 观察辐射对人脑恶性胶质瘤细胞株SHG-44辐射敏感性的影响,并探讨辐射抗性产生的机制.方法 使用胶质瘤细胞株SHG-44及经单次照射10 Gy后连续培养15代的辐射后细胞株SHG-4410 Gy,采用集落形成实验评估辐射对两种细胞株辐射敏感性的影响,流式细胞仪检测两种细胞株的辐射前后细胞周期时相分布及凋亡率,并用RT-PCR法检测cyclin B1 mRNA和miR-21的表达水平,Western blot法检测信号转导子和转录激活子3(Stat3)蛋白表达水平.结果 比较D0、SF2,SHG-44细胞(D0 =2.35、SF2=0.62),低于SHG-4410 Gy细胞(D0=3.22,SF2=0.74).与SHG-44细胞相比,SHG-4410 Gy细胞G2/M期比例减少,S期比例增多(F =22.21,P＜0.05).照射前后SHG-4410 Gy cyclinB1 mRNA相对量大于SHG-44细胞株(t=3.1、4.1,P＜0.05).照射前后的早期凋亡率分别为SHG-44 (17.60±0.26)％和(28.00±0.36)％,SHG-4410 Gy(4.20±0.30)％和(5.17±0.65)％,SHG-4410 Gy细胞与SHG-44细胞相比,早期凋亡率明显下降(t=58.0,P＜0.01).qRT-PCR及Western blot法检测SHG-4410 Gy细胞的miR-21表达及Stat3蛋白表达均较SHG-44升高.结论 照射后SHG-44细胞辐射抗性增加,可能与辐射上调细胞周期信号传导通路中的靶基因cyclinB1导致的G2/M期细胞比例减少有关;同时,辐射导致细胞miR-21表达增高,降低细胞的凋亡.     

重离子束12C6+照射人离体血建立淋巴细胞微核的剂量-效应曲线

目的　研究建立重离子束1 2 C6 + 照射人离体血诱发淋巴细胞微核的剂量 效应曲线。方法　用地面加速器产生的重离子1 2 C6 + (平均LET为 36 70keV μm) ,不同吸收剂量、不同吸收剂量率照射离体人血 ,用CB微核法观察双核淋巴细胞中的微核。结果　在 0～ 6Gy吸收剂量范围内 ,淋巴细胞微核率随吸收剂量的增加而增加 ,拟合的最佳方程为Y =6 6 5 0 9×D0 .85。结论　1 2 C6 + 照射人离体血诱发淋巴细胞微核在 0～ 6Gy吸收剂量范围内呈幂函数关系。     

星形胶质瘤细胞摄取BPA的时间及细胞周期相关性研究

目的　研究两种星形胶质瘤细胞系C6和SHG 4 4摄取BPA(p boronophenylalanine)的孵育时间与细胞周期的相关性 ,探讨BPA的选择性作用机制。方法　细胞计数法测定C6和SHG 4 4胶质瘤细胞和星形胶质细胞的生长曲线 ;将三种细胞分别培养在含BPA的培养液中 (BPA浓度为 5mmol/L ,10 B浓度相当于 5 0 μg/ml) ,4、8、12、16、2 0和 2 4h后采用感应耦合等离子体原子发射光谱 (ICP AES)法测定细胞内硼的含量 ,绘制硼含量 时间曲线 ;含硼培养液孵育 2 4h后 ,流式细胞术分离G0 /G1和G2 /M期细胞 ,ICP AES法测定不同周期细胞硼的含量。结果　C6和SHG 4 4的倍增时间均为 18 5h,星形胶质细胞的倍增时间为 2 8h。相同时间下两种胶质瘤细胞硼含量均高于对照组的胶质细胞 ,差异有统计学意义 (P <0 0 1)。两种胶质瘤细胞G2 /M期比G0 /G1期硼含量明显增高 ,差异有统计学意义 (P <0 0 1) ,而星形胶质细胞两期硼浓度差异无统计学意义 (P >0 0 5 )。两种胶质瘤细胞G2 /M期硼浓度均高于星形胶质细胞 ,差异有统计学意义 (P <0 0 1)。在G0 /G1期 ,C6和SHG 4 4与星形胶质细胞硼浓度比值分别为 1 4 6和 1 5 1,而在G2 /M期该比值则分别为 3 6 5和3 96。结论　实验中合成的BPA具备了应有的生物学活性 ,即对胶质瘤细胞的高选择性 ;有     

脑胶质瘤SHG-44细胞株照射后子代辐射敏感性

目的 探讨脑胶质瘤SHG-44细胞株照射子代生长特性及辐射敏感性变化。方法 培养人脑胶质瘤SHG-44细胞株照射后的存活子代细胞,测定其群体倍增时间,并进行集落形成实验和流式细胞仪检测,分析其辐射敏感性和细胞周期变化。结果 SHG-44细胞群体倍增时间为(22.78±2.61) h,SHG-44细胞经6 MV X射线10 Gy照射后存活子代SHG-44.10细胞群体倍增时间为(30.46±2.73) h (F=7.878,P<0.05)。SHG-44细胞和SHG-44.10细胞再次2 Gy照射后的存活分数分别为70.8%、80.6%。与SHG-44细胞相比,SHG-44-10细胞在G₂/M期比例减少,S期比例增多。结论 SHG-44细胞照射后存活子代细胞增殖延缓,辐射敏感性下降。     

用^3H—TdR释放法测定小鼠NK细胞的辐射敏感性

用~3H—TdR释放法测定C_(57)BL/6小鼠脾细胞对YAC-1细胞林的NK活性,首次将该法应用于研究NK细胞对γ线的辐射敏感性,得出如下结论:(1)小鼠整体照射后24h脾脏NK活性的D_(37)约为17Gy,D_0约为11Gy;在24～32Gy范围内仍保留着30%的NK活性,存活曲线为反“S”形,验证了NK细胞总体对辐射的相对耐受性。(2)脾细胞离体或整体照射1～2Gy后即刻NK活性均迅速下降,在2～24Gy内,离体和整体照射组的NK活性分别维持在40%～80%和50%,前者高于后者,说明NK细胞对离体照射比对整体照射更不敏感。(3)小鼠整体照射后24h,全脾细胞数在较小剂量(<4Gy)内急剧下降,然后随剂量增大变化平缓。可以推测NK活性的变化与脾细胞总数的改变有一定关系。(4)综合分析本实验结果,可以设想NK细胞本身可能存在着辐射敏感性不同的亚群。(5)用~3H—TdR释放法测定NK细胞的辐射敏感性,自然释放率低,重复性好,可靠易行。     

经动脉灌注32P-玻璃微球治疗肝癌的吸收剂量估算

目的　探讨经肝动脉灌注32 P 玻璃微球内照射栓塞治疗肝癌的吸收剂量估算方法。方法　肝癌患者 30例 ,采用改良式Seldinger技术行超选择性插管 ,经导管灌注32 P 玻璃微球、超液化碘油和吡柔比星的混悬液。术后行 β轫致辐射显像 ,观察32 P 玻璃微球的分布 ,结合分区模型和32 P内照射吸收剂量公式 ,估算肿瘤、非瘤肝组织和肺组织的吸收剂量。结果　肿瘤组织的平均吸收剂量为 (130 34± 5 4 5 3)Gy ,非瘤肝组织为 (34 73± 13 4 1)Gy;肺组织为 (6 8± 4 9)Gy。肿瘤吸收剂量 >12 0Gy者 13例 ,反应率 10 0 % ,中位生存期 2 1个月 ;<12 0Gy者 17例 ,反应率 4 7 1% ,中位生存期 11个月。结论　经肝动脉超选择性灌注32 P 玻璃微球内照射化疗栓塞治疗肝癌是一种安全有效的方法。术后 β轫致辐射显像结合分区模型估算肿瘤组织和非瘤肝组织的吸收剂量可行。     

β射线内照射抑制血管内皮细胞和平滑肌细胞增殖的研究

目的 探讨β射线对血管内皮细胞和平滑肌细胞的细胞效应。方法 培养人脐静脉内皮细胞和牛主动脉平滑肌细胞,接受0、1.25、2.5、5.0、10、20、40 Gy β射线后,以四唑盐(MTT)比色实验评价剂量-效应关系,用划痕实验研究β射线对两种细胞增殖的影响。血管内皮细胞经0、2.5、5.0、10、20 Gy照射后,进行透射电镜超微结构观察和使用流式细胞仪进行DNA倍体及凋亡率分析。结果 血管内皮细胞在照射后2、24 h,在1.25～40 Gy其增殖呈剂量依赖性抑制;在照射后48、72 h,其剂量依赖性抑制在10 Gy时处于平台期。血管平滑肌细胞在照射后2、24和48 h,其增殖抑制在10Gy时处于平台期;在照射后72h,其增殖抑制在5 Gy时处于平台期。在照射后72 h,吸收剂量为5 Gy时,血管平滑肌细胞和内皮细胞的抑制率分别为27.9％和19.0％(P=0.016);吸收剂量为10 Gy时,血管平滑肌细胞和内皮细胞的抑制率分别为33.7％和20.9％(P=0.002)。划痕实验示吸收剂量为5Gy时血管内皮细胞几乎完全充填裂隙,而平滑肌细胞较少充填裂隙;10 Gy照射后,内皮细胞充填裂隙数量减少,而平滑肌细胞几乎未充填裂隙。透射电镜未发现典型的凋亡征象,流式细胞仪检查各实验组和对照组的凋亡率均<4.4％。DNA倍体分析发现对照组G_2/M期细胞数百分比为13.09％,各照射组依次为16.     

AT细胞系辐射敏感性与细胞凋亡的相关研究

目的 探讨AT细胞高辐射敏感性与细胞凋亡之间的联系。方法 以液体闪烁测量法测3H-TdR掺入百分率来观察^60Co γ射线照射对AT5BIVA（AT）和GM0639（GM）细胞增殖的影响;实验于照射后0、24、48和72 h,用细胞流式术动态检测AT和GM细胞的自发凋亡率及^60Co γ射线照射诱发的凋亡率。结果 ^60Co γ射线0～6 Gy照射后,AT和GM两种细胞3H-TdR掺入百分率均呈剂量依赖性降低,且AT细胞降低得比GM细胞快,两种细胞3H-TdR掺入百分率与受照射剂量间可拟合成指数方程：SAT=0.9718e^-0.6855D（R^2=0.9950）、SGM=1.0928e^-0.3731D（R^2=0.9777）;AT细胞的自发凋亡率高于GM细胞;2～6 Gy照后24 h,两种细胞由辐射诱发的凋亡率均随照射剂量增大而升高,且在同一剂量点,前者凋亡率高于后者;2 Gy照射后0～72 h,AT和GM细胞的凋亡率均呈时间依赖性增加,且随照后时间延长两者间差异逐步增大,在72 h达到显著水平。结论 AT细胞高辐射敏感性与其较高的自发及辐射诱发的凋亡密切相关。     

不同LET12C6+照射人肝癌细胞SMMC-7721的存活曲线

目的 研究不同传能线密度(LET)的重离子^12C^6 对体外培养的人肝癌细胞SMMC7721存活的影响，以研究人肝癌细胞对不同LET重离子的辐射敏感性。方法 用克隆形成法研究细胞的存活情况。结果 70keV／μm的细胞存活率为10％(Ds=0.1)和1％(Ds=0.01)时的吸收剂量分别为2．94Gy和5．88Gy；30keV／μm的Ds=0.1和Ds=0.01分别为4．00Gy和8．00Gy。结论 70keV／μm比30keV／μm对人肝癌细胞SMMC—7721有更大的细胞杀死效应。     

V-79 Chinese Hamster cells irradiated with antiprotons,a study of peripheral damage due to medium and long range components of the annihilation radiation

Purpose:?Radiotherapy of cancer carries a perceived risk of inducing secondary cancer and other damage due to dose delivered to normal tissue. While expectedly small, this risk must be carefully analysed for all modalities. Especially in the use of exotic particles like pions and antiprotons, which annihilate and produce a mixed radiation field when interacting with normal matter nuclei, the biological effective dose far out of field needs to be considered in evaluating this approach. We describe first biological measurements to address the concern that medium and long range annihilation products may produce a significant background dose and reverse any benefits of higher biological dose in the target area.

Materials and methods:?Using the Antiproton Decelerator (AD) at CERN (Conseil Européen pour la Recherche Nucléaire) we irradiated V-79 Chinese Hamster cells embedded in gelatine using an antiproton beam with fluence ranging from 4.5?×?10⁸ to 4.5?×?10⁹ particles, and evaluated the biological effect on cells located distal to the Bragg peak using clonogenic survival and the COMET assay.

Results:?Both methods show a substantial biological effect on the cells in the entrance channel and the Bragg Peak area, but any damage is reduced to levels well below the effect in the entrance channel 15?mm distal to the Bragg peak for even the highest particle fluence used.

Conclusions:?The annihilation radiation generated by antiprotons stopping in biological targets causes an increase of the penumbra of the beam but the effect rapidly decreases with distance from the target volume. No major increase in the biological effect is found in the far field outside of the primary beam.     

受体结合实验及其在放射性显像剂研究中的应用进展

受体结合实验是一种重要的药物筛选方法,它通过体外实验来考察配体与受体的结合能力。目前,很多放射性显像剂是利用放射性配体与体内受体结合的高度选择性来进行受体显像的。因此,受体结合实验是放射性显像剂研究中广泛使用的一种体外评价方法,在放射性显像剂设计与筛选中发挥了重要作用。     

MTT法在放射生物学中的应用

用MTT法(噻唑蓝比色分析法)及克隆法分别进行了乏氧及有氧下照射HeLa-s₃细胞的剂量_效应关系实验, 并以单击多靶模型分别拟合曲线。结果显示MTT法拟合度高于克隆法, 拟台参数D₀值也较高, 但OER值相近, D_q及N值也相近。提示MTT法有可能取代克降法。     

胶体金法检测乙肝病毒血清标志物的实验研究

 目的:客观评价胶体金法检测乙肝病毒标志物(HBVM)的准确性,了解胶体金法与ELISA法之间的差异.方法:收集急诊手术患者的血清标本1100份,用胶体金法和ELISA法同时检测,以ELISA方法检测结果为参照,比较胶体金法检测HBVM的灵敏度和特异性.结果:与ELISA胶体金法为标准计算HBsAg和HBeAg的灵敏度和特异性均超过90%;其他3个抗体的灵敏度和特异性均低于80%.结论:胶体金法检测HBsAg和HBeAg适用于急诊筛检,乙肝三项抗体金标法存在较严重的漏检,不适合急诊筛查.     

Lack of induced mutagenesis in E. coli or human lymphoblast cell line upon long-term sub-culturing in medium from irradiated meat

Purpose: Current study was aimed to enhance the confidence of consumers as well as entrepreneurs towards food irradiation program.

Materials and methods: In this work, safety of high dose (25?kGy) irradiated meat samples (HDIMS) was ascertained by scoring mutation frequency through a long-term sub-culturing study in Escherichia coli MG1655 cells (ATCC 700926) up to 1500 generations (at 1%), 250 generations (at 5% and 10%) and human lymphoblast thymidine kinase heterozygote (TK6) cell line (ATCC CRL-8015) [at two gene loci, tk^?/+ (thymidine kinase) and hprt⁺ (Hypoxanthine Phosphoribosyltransferase)] up to 156 generations using goat meat sample. Also these samples were assayed at further radiation doses of 10, 45 and 70?kGy at 2% concentration (in cell line), and 1% (in E. coli). Study was also performed with other meat samples such as chicken, fishes (pomfret and rohu) and shrimps by carrying out limited long-term sub-culturing trials in human lymphoblast cell line. Mutation analysis was also carried out using a novel DPAR (Differential loss of Plasmid Antibiotic Resistance) assay followed by sequencing of tc^R (tetracycline resistance) gene of pBR322 plasmid isolated from E. coli cells grown for 1500 generations on HDIMS medium and RAPD (Random Amplified Polymorphic DNA) analysis of the genome.

Results and conclusion: None of the assays exhibited any induced mutation when analyzed at regular time intervals. RAPD analysis also did not indicate any change in its nucleotide sequence, ruling out the occurrence of any silent mutation. Thus, the present findings report absence of mutagenic effect of high dose irradiated meat samples.     

微生物法测定阿齐霉素的血药浓度

 目的建立测定阿齐霉素血药浓度的微生物法.方法血药浓度采用微生物法测定.结果阿齐霉素的标准/ml,具有良好的线性关系;其0.005、0.100、0.400 μg/ml 3个-4.0203(r=0.9985);线性范围为0.05～0.400μg曲线Y=0.1136X浓度的血清样本回收率分别为100.0%±0、107.8%±5.9%、103.7%±6.9%;日内变异分别为0、5.50%、6.63%;日间变异分别为9.52%、2.53%、5.20%.结论该方法简便快速,满足测定要求,可用于阿齐霉素的药代动力学研究.     

A new immunoradiometric assay (IRMA) system for thyroglobulin measurement in the follow-up of thyroid cancer patients

A new commercially available kit for thyroglobulin (Tg) measurement [immunoradiometric assay (IRMA) system based on monoclonal antibodies] was used in 479 patients with thyroid carcinoma. The effective working range was 1 ng/ml, and results were strongly correlated with our homemade radioimmunoassay (RIA). This IRMA method is less susceptible to interferences of auto-antibodies than our RIA. During thyroxine (T₄) treatment, the Tg level was undetectable in 98% of patients after total thyroid ablation, in 91% after total thyroidectomy and in 42% after lobectomy only. In this situation, Tg was found in all patients with large metastases and in 88% of those with small metastases. Following T₄ withdrawal, Tg was detectable in all patients with neoplastic disease and in 13% of those in complete remission after total thyroid ablation. In conclusion, Tg measured with this IRMA method appears to be a reliable marker of differentiated thyroid carcinoma.     

The importance of serum serotonin levels in the measurement of radiation-induced bystander cell death in HaCaT cells

Abstract

Purpose: The aim of this study was to investigate the importance of serum serotonin levels in the measurement of bystander cell death. The study was undertaken as part of an intercomparison exercise involving seven European laboratories funded under the European Union Sixth Framework Programme (FP6) Non-Targeted Effects (NOTE) integrated project.

Materials and methods: Three batches of foetal bovine serum were tested; serum with high and low serotonin content from the intercomparison exercise as well as serum from the home laboratory. Three sets of human keratinocytes (HaCaT cell line) were cultured in DMEM:F12 medium supplemented with serum with high or low serotonin content or serum from the home laboratory and both donor and recipient HaCaT cells were plated. The donor HaCaT cells were irradiated (0.5 Gy) using a cobalt 60 teletherapy unit, the medium was harvested 1 hour post irradiation and transferred to the recipient HaCaT cells. Bystander induced cell death was measured by the clonogenic survival assay and the Alamar blue viability assay.

Results: A significant reduction in cell survival, as measured by the clonogenic assay, and in cell viability, as measured by the Alamar blue assay, was observed in the recipient HaCaT cells treated with medium from irradiated cells compared to the cells treated with medium from unirradiated cells. No significant difference was found between the three batches of serum.

Conclusions: The data suggest that in our cell system and with our endpoints (clonogenic assay and Alamar blue assay), serum serotonin levels do not play a role in bystander-induced cell death.     

核酸杂交的二次酶放大镧系元素发光时间分辨荧光分析

目的建立一种超灵敏的用于核酸杂交分析的方法。方法通过二次酶放大、PCR扩增、Tb螯合物和时间分辨测量技术,测定前列腺特异抗原（PSA）DNA。结果靶PSADNA测定的标准曲线线性范围大于两个数量级;灵敏度为10pmol/L（0.5fmol/孔）;当靶PSADNA为10、30和60pmol/L时,准确度和精密度分别为77%～95%和12.9%～15.3%。结论本法是一种超灵敏的、简捷和快速的全新分析方法,有很好的应用前景。