Fas、Bcl-2在γ射线体外诱发的白血病小鼠骨髓细胞中的表达

目的 :观察 Fas、Bcl- 2在 γ射线体外诱发的急性淋巴细胞白血病小鼠骨髓细胞中表达情况 ,以探讨辐射致癌的机制。方法 :采用 4次 1.75 Gyγ射线全身照射 BAL B/ c小鼠诱发白血病模型 ,通过流式细胞仪对照射后白血病组、未癌变组及对照组小鼠骨髓细胞中 Fas、Bcl- 2的表达进行检测 ;应用抗 Fas抗体诱导细胞凋亡 ,进一步观察 Fas、Bcl- 2的表达对骨髓细胞凋亡的影响。 结果 :白血病小鼠骨髓细胞 Fas表达较未癌变组及对照组明显下降 (P<0 .0 1) ,而 Bcl- 2的表达明显增强 (P<0 .0 1) ;白血病小鼠骨髓细胞明显耐受抗 Fas抗体诱导的细胞凋亡。 结论 :Fas低表达、Bcl- 2高表达导致了细胞凋亡受到抑制 ,这可能是辐射引起小鼠急性淋巴细胞白血病的机制之一。     

放射性~(125)I粒子组织间植入对家兔尿道损伤的实验研究

目的:研究不同剂量的放射性125I粒子对家兔尿道的放射性损伤。方法:麻醉下将放射性125I粒子植入雄性家兔尿道旁1.0cm处。125I粒子的放射性粒子活度分别为14.8MBq(A组)、29.6MBq(B组)和44.4MBq(C组),对照组(D组)仅尿道旁种植相当于粒子大小无放射性的无菌铅管1粒。植入后4周,摄尿道片,观察粒子位置等情况;原手术切口切开,取放射粒子周围2.0cm范围内的家兔尿道组织作肉眼、光学显微镜和电子显微镜观察,进行放射性损伤的评价。结果:术后4周,肉眼及光学显微镜观察,实验组与对照组粒子周围的尿道粘膜、粘膜下及肌层所见基本一致;C组少部分电镜视野中观察到尿道上皮胞质出现较多空泡变性、空化、嵴稀疏等超微结构的损伤。光镜下尿道入射性损伤评分,A、B、C、D组分别为(2.20±0.18)、(2.23±0.15)、(2.27±0.10)、(2.10±0.17)分,A、B、C组与D组相比,差异无显著性(P>0.05)。对线粒体作FlaMeng半定量分析,A、B、C、D各组评分分别为(1.23±0.13)、(1.34±0.25)、(1.41±0.30)、(1.12±0.13)分,A、B、C各组与D组(对照组)相比,差异无显著性(P>0.05)。结论:放射性125I粒子对尿道放射性损伤随粒子的放射性活度的增加而逐渐加重,呈明显的放射性活度效应关系;正常剂量的放射性粒子对尿道的损伤是很轻微的,是安全可行的。     

^125I放射微粒微创植入治疗前列腺癌

目的观察^125I放射微粒植入对前列腺癌的治疗效果。方法对26例临床确诊为前列腺癌患者经皮穿刺在癌组织植入^125I放射微粒，每例平均36粒，术后复查肛诊、B超、影像学及血生化指标。结果患者植入治疗经过顺利，2例少量出血，留置导尿后愈合，3个月后经肛诊、直肠B超示结节缩小，前列腺特异性抗原（PSA）降低，多普勒超声显示结节内动脉收缩期最大血流速度（VS）、阻力指数（RI）及动脉搏动指数（PI）均明显下降。结论^125I放射微粒植入对前列腺癌的治疗安全性好、效果可靠。     

Effect of Temperature on the Longitudinal Variability of Quantitative Ultrasound Variables

It is unclear whether longitudinal change in phantom measurements bears any relation to the long-term in vivo instrument performance of quantitative ultrasound devices. Longitudinal quantitative ultrasound phantom data were obtained by measuring the manufacturer-provided phantom at ambient temperature and two different sets of Leeds phantoms at either ambient temperature or following a phantom temperature-control protocol. Measurements were performed using the Achilles Plus bone densitometer. Changes in longitudinal phantom data were compared to in vivo quantitative ultrasound data obtained from seven healthy, young volunteers. A cosinor model with linear trend and Hotelling's T2-test were used to quantify seasonal rhythms and long-term drift in quantitative ultrasound variables. Temperature effects and marked seasonal rhythms on quantitative ultrasound phantom measurements were evident but were far less apparent in vivo. Longitudinal precision of quantitative ultrasound variables was poorer for the manufacturer-provided phantom than for phantoms that were subjected to a temperature-control protocol or for healthy volunteers. This study has shown that longitudinal precision and longitudinal change differs between in vivo and phantom data. Longitudinal quantitative ultrasound measurements for monitoring change in skeletal status cannot, as yet, be properly controlled.     

肿瘤物理治疗技术及设备

简要介绍了肿瘤的放射治疗和热治疗的技术及设备，介绍了各种技术及设备的特点。     

Data Bank and Consulting System for Medical Management of Patiens with Acute Radiation Sickness

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钛接圈在不同烘烤温度下对镍铬合金浇注质量的影响

目的：研究钛接圈在不同烘烤温度下浇注镍铬合金的质量关系。方法：选择临床骨融合种植义齿二期手术后典型病例石膏模型，在基桩上固定纯钛接圈，常规制作桥架蜡型，使桥架接圈周围嵌体蜡厚度为１ｍｍ，常规内、外包埋，放置２４ｈ后，分４组不同温度烘烤，ａ组烘烤升温至６００℃，ｂ组升温至６５０℃，ｃ组升温至７００℃，ｄ组升温至８００℃。每组试件１０个，共４０个试件。用远红外温度测试仪控制合金浇注温度为１３０６℃，自然冷却后，电镜观察。结果：钛接圈烘烤温度６００℃、８００℃时镍铬合金支架断口出现二次断裂及气孔机会多，当６５０℃、７００℃时二次断裂出现机会少。结论：在常规牙科操作中，钛接圈烘烤温度为６５０℃、７００℃时，浇注镍铬合金较好。     

壳聚糖辐射效应的研究（Ⅰ）──辐照剂量与分子量的关系及辐射裂解的G（S）值

通过粘度的测量，考察了壳聚糖在不同条件下经不同剂量γ射线辐照所引起的分子量的变化，并分别计算了真空和空气中壳聚糖辐射裂解的Ｇ（Ｓ）值。     

Genetic ecotoxicology I: DNA integrity and reproduction in mosquitofish exposed in situ to radionuclides

Female mosquitofish (Gambusia affinis) were collected from two sites located on the US Department of Energy's Oak Ridge Reservation that are contaminated with 137Cs, 90Sr, other radionuclides and chemical genotoxicants. Fish from non- radionuclide contaminated environments located off the reservation were also collected. DNA, extracted from liver tissue and blood cells, was examined by gel electrophoresis for structural damage in the form of strand breakage. In general, the level of DNA strand breaks was elevated in fish from radionuclide-contaminated sites with observed differences in the number and type of strand breaks between liver tissue and blood cells. The number of malformed embryos was higher in fish at the contaminated sites, and varied with season. Fecundity was negatively correlated with the level of double strand breaks in the DNA of fish from one contaminated site. Females with broods that included malformed embryos had more DNA strand breakage than those that did not; and furthermore, a threshold effect was observed between the occurrence of malformed embryos and the presence of double strand breaks in the DNA of the mother. These findings have implications for both ecological risk assessment and evolutionary ecology     

Central tumour necrosis factor-α mediates the early gastrointestinal motor disturbances induced by lipopolysaccharide in sheep

Cytokines are involved in fever and other symptoms of the acute phase response induced by endotoxins. The aim of this work was to study the involvement of central tumour necrosis factor-alpha (TNF-alpha) in the changes induced by lipopolysaccharide (LPS) on gastrointestinal (GI) motility in sheep. Body temperature and myoelectric activity of the antrum, duodenum and jejunum was recorded continuously. Intravenous (i.v.) administration of LPS (0.1 micro g kg-1)-induced hyperthermia, decreased gastrointestinal myoelectric activity and increased the frequency of the migrating motor complex (MMC). These effects started 40-50 min after LPS and lasted for 6-7 h. TNF-alpha (50 and 100 ng kg-1) mimicked these effects when injected intracerebroventricularly (i.c.v.) but not i.v. Pretreatment with soluble recombinant TNF receptor (TNFR:Fc, 10 micro g kg-1, i.c.v.) abolished the TNF-induced actions and reduced those evoked by LPS. Furthermore, the effects induced by either LPS or TNF were suppressed by prior i.c.v. injection of indomethacin (100 micro g kg-1). In contrast, the i.v. injections of TNFR:Fc or indomethacin were ineffective. Our data suggest that LPS disturbs GI motility in sheep through a central pathway that involves TNF-alpha and prostaglandins sequentially.