不同剂量60 Co γ射线照射对大鼠颌下腺凋亡的影响

目的 探讨不同剂量60Coγ射线照射对大鼠颌下腺凋亡及相关因子表达的影响.方法 将Wistar大鼠随机分4组：（1）正常对照组;（2）放疗7.5Gy组;（3）放疗15 Gy组;（4）放疗22.5 Gy组.放疗组大鼠给予一次性γ射线辐射,每只辐射量按分组设定的剂量（7.5、15、22.5 Cy）给予.对照组未予照射.采用免疫组织化学法检测P53、Caspase-3表达情况以及原位切口末端标记（TUNEL）法检测细胞凋亡.结果 与对照组比较,放疗组P53与Caspase-3的表达增强.Tunel染色显示的细胞凋亡主要见于导管细胞,随着放疗剂量增加,凋亡愈明显.结论 60Co γ射线照射可引起大鼠颌下腺早期细胞凋亡.60Co γ射线（7.5、15、22.5 Gy）照射诱导的颌下腺细胞凋亡有剂量-效应关系.     

铯137辐照对库存红细胞表面分子CD35、CD47的影响

目的：探讨铯137（137 Cs）辐照对库存红细胞表面分子红细胞1型补体受体（complement receptor type 1,CR1 or CD35）及 CD47分子的影响。方法采集60例健康献血者静脉血,制备去白细胞的悬浮红细胞,并将其分为2组各30例,未辐照组常规4℃保存,辐照组采用25Gy 137 Cs辐照后4℃保存。分别于第0、7、14、28、35天收集2mL 样本。采用直标法流式细胞术检测红细胞表面分子 CD35、CD47。结果辐照组和未辐照组红细胞 CD35、CD47的表达均随着4℃保存时间的延长而减少,2组的时点间以及组间·时点间交互作用比较差异均有统计学意义（P ＜0．01）,但组间差异无统计学意义（P ＞0．05）。结论25Gy 137 Csγ射线辐照对保存期内红细胞 CD35、CD47表面分子表达无明显影响。     

《β射线所致皮肤剂量估算规范》释疑

国家职业卫生标准——《β射线所致皮肤剂量估算规范》已经卫生部批准并发布.此标准是在广泛调研国内外文献、系统学习相关法律法规和进行一些方法验证的基础上制定的.此标准主要用于β射线皮肤污染所致的皮肤剂量估算,对皮肤辐射损伤的诊断和β射线皮肤污染的去污处理都有指导意义.该文对标准的主要内容及关键性技术进行了释疑.     

Changes in aqueous humour following single or repeated UVB irradiation of rabbit cornea

Background Aqueous humour is the main nutritive source for corneal and lenticular tissues, and knowledge of a possible cumulative effect of ultraviolet radiation (UVR) on its metabolic profile might be of great help in the assessment of cataract risks. By using high-resolution ¹H nuclear magnetic resonance (NMR) spectroscopy, it was possible to evaluate the effect of a single and repeated UVB radiation of the rabbit eye with the same overall dose on the aqueous humour. Methods Samples of aqueous humour from twenty-four albino white rabbit eyes were examined for the effects of UVB exposure (312 nm). In the first group (UVB1), four animals were irradiated with a single dose 3.12 J/cm² (21 minutes) of UVB radiation. The animals in the second group (UVB2, n = 4) were irradiated three times for 7 minutes every 2nd day (dose of 1.04 J/cm²; days 1, 3, 5) to give the same overall dose (3.12 J/cm²). The third group (n = 4) served as an untreated control group. ¹H NMR spectra of aqueous humour from all eyes were obtained. Special grouping patterns among the tissue samples and relative percentage changes in particular metabolite concentrations were evaluated using appropriate statistical methods (multivariate analysis, Independent sample t-test). Results Significant alterations in the metabolic profile of aqueous humour from UVR-B exposed rabbit eyes and an apparent cumulative effect of repeated UVB irradiation were observed. Conclusions Application of a Carr-Purcell-Meiboom-Gill spin echo pulse sequence was found to have a great advantage for correct analysis of the results obtained with NMR spectroscopy of aqueous humour from eyes where increase of protein level due to an inflammatory process could not be excluded. Grants were received from: The Norwegian Quota Program The Faculty of Medicine, Norwegian University of Science and Technology The Norwegian Research Council The Grant Agency of the Czech Republic No. 304/06/1379 The Academy of Sciences of the Czech Republic AVOZ50390512.     

伽玛刀治疗晚期胰腺癌的临床研究

目的探讨立体定向放射治疗晚期胰腺癌的近期临床疗效。方法采用OUR-QGD型立体定向伽玛射线体部治疗系统(体部伽玛刀)治疗了31例晚期胰腺癌患者。伽玛刀治疗采用三维立体定向治疗计划系统给予患者精确定位,采用旋转聚焦原理使60Co放射源围绕肿瘤中心作锥状非共面穿射聚焦至靶区。通常剂量为50%~65%等剂量曲线包绕靶区的95%以上;肿瘤≤5cm的单次周边剂量3.5～4.5Gy,肿瘤>5cm的单次周边剂量3.0～4.0Gy;治疗总剂量为32～48Gy;治疗次数8～11次,大多数患者为隔日治疗。结果伽玛刀治疗过程中既有患者上腹部及腰背部疼痛明显减轻,12位患者黄疸消退。伽玛刀治疗3个月第1次复查,病变部位达到CR:10例,PR:16例;总有效率(CR+PR)83.8%。未见穿孔、大出血、持续高热等严重并发症发生。结论体部伽玛刀治疗晚期胰腺癌能使肿瘤局部得到准确的高剂量照射,周围正常组织损伤小,近期疗效理想,为临床肿瘤医师提供了一个新的治疗手段。     

不同X线类型的地方性氟骨症患者骨矿物质含量分析

用~(125)I光子吸收测定法测定了128例地方性氟骨症患者左前臂尺、桡骨的骨矿物质含量,结果表明:氟骨症患者骨矿物质含量低于正常人水平,其中早期改变、硬化型、疏松型和混合型四种不同类型的氟骨症患者骨矿物质含量也不相同,骨矿物含量水平由高至低排列顺序为硬化型>早期改变>混合型>疏松型。     

肺部X射线照射后炎性细胞因子在支气管上皮细胞中的表达

目的研究C57BL/6J小鼠双肺照射12Gy后,炎性细胞因子肿瘤坏死因子-α(TNF-α)、白介素-1α(IL-1α)和白介素-6(IL-6)蛋白在肺组织中的表达。方法实验组小鼠给予双肺单次照射12Gy,对照组小鼠在相同条件下双肺假照射0Gy。分别于照射后0·5、1、3、6、12、24、48和72h,1、2、4、8、16和24周处死,通过免疫组织化学方法和图像分析定量检测肺组织中TNF-α、IL-1α和IL-6蛋白的表达。结果胸部照射后数小时,上述炎性因子蛋白表达即比对照组显著增加。在随后的急性放射性肺炎阶段,支气管上皮以及肺间质的炎性细胞产生了大量的TNF-α(最大值出现在全肺照射后第4周,9·74%±1·78%)、IL-1α(最大值出现在全肺照射后第8周,14·76%±7·77%)和IL-6(最大值出现在全肺照射后第8周,4·28%±1·33%)。结论肺部照射以后,在胸部照射的最初数小时以内,支气管上皮是上述炎性因子最重要的来源,这些炎性细胞因子进一步通过征集和激活炎症细胞来促进和放大放射性肺炎的产生和发展。     

Radiation induced renal damage in mice: Influence of fraction size

Two functional assays (urine output and isotope clearance) have been used to assess the response of mouse kidneys to localized irradiation. The influence of the size of each X ray dose has been investigated by using single doses and two to 16 equal fractions. The X ray dose in each treatment ranged from 16 Gy as a single dose to 3.5 Gy (×16 fractions). Three separate experiments were performed, one with and two without anesthetic for the irradiation. Sequential testing of the mice was used to determine the latent period before radiation damage became manifest. Latency was found to be dose dependent; functional defects appeared earlier after higher doses but there was a minimum period of 14–19 weeks before the onset of damage. The repair capacity of the kidney was assessed by comparing isoeffective doses from the dose-response curves. Within 24 hours a recovered dose of 5 Gy was obtained if 2 doses were used instead of one. The isoeffective dose increased with fractionation and a fraction number exponent of 0.42 was obtained. Analysis of the data using a linear quadratic model yielded a low $\text{α}\text{β}$ ratio of 0–3.5 Gy. This is similar to values obtained for other late responding normal tissues and implies that the use of small dose fractions will spare the kidney relative to tumors and acutely reacting normal tissues. In conventional radiotherapy more effective sparing of the kidney should be achieved by using thin shielding with each fraction than by completely shielding the kidney for the latter part of the treatment course.     

DXG250－A型电子消毒柜杀菌效果的实验观察

ＤＸＧ２５０－Ａ型电子消毒柜装有２支１５Ｗ高臭氧紫外线灯管。作用３０分钟，可杀灭物品表面大肠杆菌、金黄色葡萄球菌９９．９９％以上，枯草杆菌黑色变种芽胞９９．９７％以上，用黑布遮挡紫外线单独靠臭氧杀菌时，作用３０分钟可杀灭物品表面大肠杆菌９９．７５％以上，６０分钟可将其全部杀灭。对柜内紫外线强度与臭氧浓度进行了测定，并观察了使用柜内风机对臭氧杀菌效果的影响，     

高能重离子的生物学效应初探

为研究高能重离子对高等植物种子的影响，用核径迹探测器与药用植物干种子复合制成生物叠的方法，在卫星搭载实验中，初步探查了空间环境对莨菪和藿香的生物学效应，发现单纯失重因素对当年栽培的植株无显著影响，但被高能重离子击中的种子经３个月储存后，其栽培的植株长势有明显增快，开花和结实时间也早于对照组，但染色体凶有损伤或变异。确认这种方法能较精细地鉴别空间环境中持续失重和高能重离子击中两个因素的生物学效应，是