低剂量辐射增强小鼠肿瘤基因-放射治疗效应的免疫学机制研究

目的 探讨低剂量辐射全身照射对小鼠Lewis肺癌移植肿瘤基因-放疗方案中的免疫增强作用机制。方法 小鼠右后肢皮下接种Lewis肺癌细胞建立荷瘤模型,基因-放疗组中小鼠肿瘤局部注射由多聚乙烯亚胺包裹的pEgr-IL18-B7.1重组质粒,分别接受由2 Gy 局部照射和0.075 Gy 全身照射组合的不同治疗方案,通过³H-TdR标记方法检测小鼠CTL和NK细胞毒活性,ELISA方法检测TNF-α和IFN-γ分泌活性,观察各治疗组对荷瘤小鼠抗肿瘤免疫的作用。结果 在pEgr-IL18-B7.1基因治疗方案中,单次大剂量辐射局部照射后加多次低剂量全身照射与常规多次大剂量辐射局部照射相比,小鼠CTL和NK细胞毒活性显著增强,TNF-α和IFN-γ分泌活性有不同程度的增高。 结论 低剂量辐射可以通过促进CTL和NK细胞毒效应,上调TNF-α和IFN-γ细胞因子表达,从而增强机体抗肿瘤免疫功能,提高肿瘤基因-放疗的抑瘤效果。     

Safety, tolerability and pharmacokinetic study of recombinant human parathyroid hormone in healthy male Chinese subjects

AIM： To determine the safety, tolerability and pharmacokinetic parameters of a new drug recombinant human parathyroid hormone [ rhPTH （1-84）] in healthy male Chinese subjects. METHODS： domly divided Thirty-six healthy male volunteers were rangroups received into 3 groups. The volunteers in these single subcutaneous injection of rhPTH （ 1-84） in a dosage of 1, 2 and 4 μg/kg respectively. Blood samples were obtained before and after administration within 24 hours. The rhPTH concentrations in sennn were determined by enzyme linked immunosorbent assay （ELISA）. The pharmacokinetic parameters determined with use of standard noncompartmental analysis were the maximum serum concentration （ Cmax ）, the time to attain that concentration （ tmax ）, and the area under the serum concentration-time curve up to 24 hours（ AUC0-24 ） and up to infinity （AUC0-∞）. Dose proportionality of pharmacokinetic parameters （AUC, Cmax of every volunteer of each dosage and A UC was computed from log transformed data） and was examined by mean of analysis of variance （ANOVA） using SPSS software package. In the study, subjects＇ symptoms, objective signs, and vital signs, including blood pressure, heart rate, respiratory rate and body temperature, were checked and 12-lead electrocardiography was recorded before and after drug administration within 24 hours. Routine laboratory tests, including hematology, blood biochemistry, serum electrolyte, and urinalysis, were performed before and after drug administration within at 24 hours.[第一段]     

Acute urticaria and hepatitis complicating high-dose methotrexate therapy

We report an unusual case of anaphylaxis and hepatitic dysfunction in a child with the administration of the twenty-third course of high-dose methotrexate. The latter had been used as an adjuvant to prevent pulmonary metastases and the prior 22 courses had been well tolerated. An attempt to reinstate methotrexate after the twenty-third course was again followed by a similar reaction. © 1995 Wiley-Liss, Inc.     

高电压胸部摄影诊断和防护效果研究

作者以体模实验为基础。测定了不同管电压拍摄胸片时的病人剂量，考察了提高管电压对胶片影像质量的影响，结果表明，使用高电压拍摄胸片比使用低电压有利于降低病人剂量，在增加影像信息量，提高肋骨阴影区和纵膈区灶检出率方面更有较大优越性，此外，使用高电压技术不家利于延长Ｘ射线管的使用寿命。     

Growth, bone maturation and pubertal development in children with the EMG-syndrome

In 7 patients (5 girls, 2 boys) with the EMG or Wiedemann-Beckwith syndrome, statural growth, bone age (BA), weight and pubertal development were studied longitudinally. Height was above the 90th percentile (%) for chronological age (CA) after age 2 years, reaching an average of 2.5 SD above the mean at or after puberty. Adult or attained height also exceeded significantly (P<0.015) parental (genetic) target height by 13.2 cm on the average. In one girl, adult height prognosis (190 cm) could be reduced to an adult height of 183 cm by high-dose estrogen treatment. In most children, growth velocity remained above the 90th % up to 4–6 years of age and normalized thereafter. In all patients studied, bone age was markedly advanced and particularly so during the first 4 years after birth. Weight was above the 90th–97th % during infancy and early childhood and remained there, appropriate or slightly subnormal for height, until adulthood, except for 3 girls who reached and maintained the 50th % during or after puberty. Spontaneous pubertal development occurred within normal limits for CA and around the 50th % for BA. Except for the marked bone age acceleration, the reason for the increased statural growth and adult height in patients with the EMG syndrome is still unknown.     

对儿童X线体检中减少照射剂量的探讨

目的:探讨儿童在X线体检中减少照射剂量的方法。方法:应用东芝500mA遥控X线机、FJ-427型热释光剂量仪等设备,对100名3~5岁儿童体检时,随机分成两个对照组、每组50名,分别接受胸透或平片检查,对检查测得数据均进行统计学处理。结果:胸透时胸部接受的照射剂量是平片的22倍多,其它部位接受的X线散射剂量平均值之比亦在20~30倍之间。结论:在儿童X线体检中应采用常规胸片替代胸透,可以有效地降低其辐射危害。     

电子对生物分子DNA损伤可能性的分析

目的研究电子在人体组织等效材料中形成的“簇点”能量分布情况，以及簇点的产生对生物效应发生的意义。方法针对电子与人体组织等效介质作用的物理机理，利用蒙特卡罗(MC)方法，按一个个相互作用事件(电离、激发、弹性散射、Auger电子发射)方式真实模拟电子在介质中的径迹，通过对这些事件进行统计分析，得到相关结论。结果电子在穿过介质过程中，主要以簇点(大于30％)形式沉积能量，并且80％以上的簇点中的能量沉积在50eV以上；簇点的密集程度与电子能量、簇点直径密切相关，簇点中能量沉积也取决于辐射类型和能量。结论簇点中的能量沉积是诱发组织细胞核内DNA分子各种损伤的最主要因素。     

Indoor radon measurement with The Lucas cell technique

Rn-222 is the most important source of natural radiation and is responsible for approximately half of the received dose from all sources. Most of this dose is from inhalation of the Rn-222 progeny, especially in closed atmospheres. A Lucas cell technique, using a portable device, “PRASSI” (SILENA mod. 5S), for Rn-222 measurements inside the Centre for Radiation Protection and Radioecology (ZSR), Hannover University was used. The portable radon monitor PRASSI is suitable for radon gas continuous or grab sampling measurements with the scintillation cell technique. In recognition of the wide periodic variations in concentration, measurements were made daily for extended periods. At the same time, meteorological variables, such as temperature and humidity were observed so that their influence on radon levels could be evaluated. The radon average concentration during the year was about 55.9 Bq/m³ which gives rise to an annual effective dose 2.2 mSv y⁻¹. The radon concentration is within the limits prescribed by the International Commission for Radiation Protection. A detailed analysis of radon distribution with seasonal variation is presented.     

直线加速器十年故障分析总结

目的分析和总直线加速器十多年来的故障。方法根据十多年来的故障维修记录，统计和分析直线加速器各阶故障率及故障特点。结果直线加速器使用早期由于机器不稳定故障率比较高，使用中期及其比较稳定，故障率比较低，使用后期由于零部件老化，故障率比较高。