RADIATION INDUCED PROGRESSIVE DECREASING IN THE EXPRESSION OF REVERSE TRANSCRIPTASE GENE OF hEST2 AND TELOMERASE ACTIVITY

Objectites. In order to identify the relationship between telomerase and the biological effect of radiation injury, and investigate the role of human telomerase catalytic subunit gene (hEST2) reverse tranacriptase(RT) seg-ment in the expression of telomerase activity. Methods. Tumor FIeLa cells, KB cells and A431 cells were employed to measure the change in telomeraseactivity after 60Co-ray irradiation at RNA level and protein level. Quantitative PCR and Northern blotting wereused to determine the expression of bEST2 RT segment that encodes seven motifs of the human telomeres, a PCR-besed telomeric repeat amplification protocol (TRAP)was used to assay telomerase activity after exposure toradiation. Results. Both of telomerase activity and the expression hEST2 RT segment were decreased with increasingdosage of radiation. In addition, testing the expression of motifs domain is similar to the measurement of telomerase activity. Conclusion. The detection of the hEST2 BT segment by Northern blotting and quantitative PCR are new methods for testing Uflomerase activity. Furthermore, radiation can cause a dose-dependent decrease in telomerase activity. The effect of radiation on telomerase is one possible reason for the death of cancer ceils after irradiation.     

γ射线诱导人肝癌细胞表达B7-1共刺激分子的研究

目的　研究电离辐射与肿瘤细胞B7- 1分子表达之间的关系 ,探讨肿瘤细胞辐照后免疫原性增强的机制。方法　采用间接免疫荧光 -流式细胞仪分析技术 ,研究在用不同剂量γ射线照射SMMC - 772肝癌细胞后、培养不同时间内SMMC - 772细胞B7- 1共刺激分子的表达水平。并用3H -TdR释放法测定照射和未照射肿瘤细胞与淋巴细胞共反应后的细胞毒活性。结果　未照射和经 10、2 0、30Gy照射的人肝癌细胞不表达B7- 1分子。经 40、5 0、6 0Gy剂量照射后 ,SMMC - 772肝癌细胞表达B7- 1分子 ,最高达 6 6 .8± 1.3% ,与对照组比有非常显著性差异 (P <0 .0 1)。表达时间的高峰在照射后培养 72h时 ,最低在照射后培养 2 4h时 (P <0 .0 5 )。细胞毒活性测定结果表明 ,表达B7- 1分子的SMMC - 72肝癌细胞与淋巴细胞共反应后 ,细胞毒活性明显高于未照射组 (P <0 .0 1)。结论　γ射线可诱导肝癌细胞表达B7- 1分子 ,从而增强肿瘤细胞的免疫性     

影响淋巴细胞共刺激作用的体外实验研究

目的　观察CD3单抗、CD2 8单抗、PHA和低剂量辐射对淋巴细胞增殖的影响 ,探讨影响T淋巴细胞信号转导的因素。方法　分别以CD3单抗、CD2 8单抗、PHA和低剂量辐射作为作用因素 ,用3H TdR掺入法观察在这些因素作用下 ,淋巴细胞增殖反应情况。结果　CD3单抗和CD2 8单抗联合刺激、PHA和低剂量辐射单独或联合处理 ,均可使淋巴细胞明显增殖。但CD3单抗和CD2 8单抗单独刺激 ,淋巴细胞增殖不明显。结论　CD3单抗和CD2 8单抗联合作用可使淋巴细胞有效增殖 ,PHA和低剂量辐射具有相似作用 ,对细胞免疫调节有重要意义     

成人高分级脑胶质瘤术后放疗设野的探讨

目的：探讨用局部扩大野的设野方法照射成人高分级脑胶质瘤的可行性。方法：经术后病理证实为Ⅲ～Ⅳ级星形细胞瘤５３例,分为实验组（Ａ组,２５例）和对照组（Ｂ组,２８例）,放疗采用常规分割,总剂量ＤＴ５０～６５Ｇｙ,设野方法：Ａ组用局部扩大野,Ｂ组用全脑加局部照射野。随访其放疗后生存期及１、３年生存率,复发率。并行统计学处理。结果：Ａ、Ｂ组的中位生存期分别是１４个月,１５．５个月,１,３年生存率分别是８０     

晚期和复发头颈癌立体定向放射治疗近期疗效观察

目的 探讨晚期和复发头颈癌立体定向放射治疗的近期疗效、并发症等。方法 １９９７年１０月至１９９８年１０月采用立体定向放射治疗（ＳＲＴ）晚期和复发的头颈癌２８例,其中ＮＰＣ１７例,鼻腔副鼻窦肿瘤４例,舌根癌３例,喉癌２例、颈段椎管内髓外肿瘤术后残留外侵１例,软腭癌１例,肿瘤体积在,最大径２．５￣７．０ｃｍ,中位数４．５ｃｍ,１５例患者有严重的局部疼产能等闰状,３例有鼻阻塞、照射剂量４￣８Ｇｙ／次,隔     

Effect of irradiation on transforming growth factor-β secretion by malignant glioma cells

Glioblastoma cells secrete transforming growth factor- (TGF-), whichhas a variety of immunosuppressive properties. We investigatedthe effect of irradiation TGF- secretion by malignantglioma cells. Three malignant glioma cell lines (T98G,A172, KG-1-C) were cultured and irradiated using 10and 50 Gy Linac radiation. After further culturefor 36 hours in serum-free culture medium, thesupernatants were collected. The TGF- activity in theculture supernatants was determined using a specific bioassay.The levels of the active form and totalTGF- in the supernatants from irradiated malignant gliomacells decreased compared to those from un-irradiated cells.However, since irradiation inhibited the growth of tumorcells, the amount of TGF- secretion per cellin irradiated cells tended to increase after irradiation.These results suggest that malignant glioma cells canstill secrete TGF- and activate latent TGF- evenafter large dose irradiation, despite the inhibition oftumor growth.     

中药配合低能量氦—氖激光血管内照射为主治疗缺血性中风疗效观察

目的：观察中药配合低能量氦－氖激光血管内照射为主治疗缺血性中风疗效。方法：治疗组：用中药配合低量氦－氖激光血管内照射为主治疗缺血性中风６９例;对照组：用降纤酶、尼莫通治疗缺血性中风４２ 例。结果：治疗组基本痊愈４８ 例,显效８例,有效７例,无效５ 例,恶化１ 例,有效率为９１．３０％ 。对照组基本痊愈２０例,显效１例,有效９ 例,无效１１ 例,恶化１例,有效率为７１．４３％ 。经χ２ 检验,χ２＝ ７．６,Ρ＜ ０．０１,有显著差异。结论：治疗组中药配合低能量氦－氖激光血管内照射为主治疗缺血性中风综合疗效明显优于对照组用降纤酶和尼莫通治疗缺血性中风     

自血光量子疗法治疗脑梗死近期疗效观察

目的探讨自血光量子疗法治疗脑梗死近期疗效。方法将同期住院的８０例脑梗塞病人随机分成治疗组和对照组,两组一般资料及治疗前神经功能缺损评分无显著差异（Ｐ＞０．０５）。治疗组采用光量子自血疗法治疗,对照组采用常规的川芎嗪治疗。结果治疗后,治疗组与对照组比较,治疗组神经功能缺损积分低于对照组,有显著差异（Ｐ＜０．０１）。     

低剂量γ-射线及香烟对仔鼠发育和反射行为的影响

母鼠暴露于低剂量γ－射线（照射源６０Ｃｏ,剂量为０、０．２５、０．５、１．０ＧＹ）及香烟烟雾水溶物（浓度为０、０．５、１．０、１．５、２．０支／只）,可使子代小鼠发育（开眼、张耳、生毛、出牙）及反射行为（平面翻正、空中翻正、视觉定向、听觉惊愕）出现不同程度的延迟。并且低剂量γ－射线与香烟烟雾水溶物还有极显著的协同效应。     

Thyroidal handling of radioiodine in sea level residents exposed to hypobaric hypoxia

In the present investigation thyroidal accumulation of radioiodine and its release were assessed by direct testing of thyroid function using radioactive iodine, in vivo, in sea level residents intermittently exposed to hypobaric hypoxia. Thyroidal accumulation of radioiodine and its turnover were examined daily for 14 days. Twelve healthy human male volunteers were divided into three groups, with an equal number of individuals in each group. A decompression chamber was used to expose each group of subjects to hypoxic conditions at a simulated altitude of 3810 m for 8 h/day for 14 days. An oral dose of 25Ci iodine-131 was administered to each individual of the first group immediately before the initiation of intermittent hypoxia. The second group of subjects received a tracer dose at the beginning of the 4th day of the 14 days, intermittent exposure to hypoxia, while the third group received the tracer dose 1 week after the completion of the exposure. Control studies were carried out on the subjects before they were subjected to the experimental conditions. Thyroidal accumulation of¹³¹I in experimental subjects during the hypoxic state and in the post-hypoxic state was higher than in the control studies. The pattern of accumulation during exposure to hypoxia and in the post-hypoxic state showed multiple peaks of radioactive iodine uptake (PRAIU), a unique feature. The multiple PRAIU by the thyroid in experimental subjects were sharp and of short duration, reflecting an increased rate of¹³I release from the thyroid. Control subjects had a single PRAIU by the thyroid 24 h after the administration of tracer.