Die Berechnung von Konversionsfaktoren für den Strahlenschutz bei äußerer Strahlenexposition

Calculations are essential for radiation protection practice because organ doses and effective doses cannot be measured directly. Conversion coefficients describe the numerical relationships of protection quantities and operational quantities. The latter can be measured in practical situations using suitable dosimeters. The conversion coefficients are calculated using radiation transport codes - usually based on Monte Carlo methods - that simulate the interactions of radiation with matter in computational models of the human body. A new generation of human body models, the so-called voxel models, are constructed from image data of real persons using suitable image processing systems, consequently, they represent the human anatomy more realistically than the so-called mathematical models. The numerical effects of realistic body anatomy on the calculated conversion coefficients can amount to 70 % and more for external exposures.     

人A1u重复序列作为脐血造血干细胞异种移植成功指标的实验研究

目的　探讨将 Alu重复序列作为人脐血造血干细胞异种移植成功植入指标的可行性。方法　经体外扩增后的人脐血细胞移植给 X线照射预处理的 BAL B/ C裸鼠 ,8周后取骨髓及脾脏 DNA,分别检测人特异的 Alu序列和 Cart- 1基因的表达率 ,以 DNA序列分析证实所扩增序列的正确性。结果　受者裸鼠骨髓、脾脏 DNA经 PCR扩增到 Alu序列 2 2 4 bp特异性条带的 ,分别为 11/ 14只 (78.6 % )和 10 / 14只 (71.4 % ) ,检测到 Cart- 1基因 15 6 bp片段的分别为 8/ 14只 (5 7.1% )和 4 / 14只 (2 8.6 % ) ,两种方法间差异无显著性。结论　 A 1u- PCR法用于人脐血异种移植成功植入检测指标是可行的 ,并且有可能更灵敏和稳定     

t—PA,u—PA／uPAR及其抑制剂PAI—1在乳腺肿瘤的表达

目的　研究组织型纤溶酶原激活剂（ｔＰＡ） 、尿激酶型纤溶酶原激活剂（ｕＰＡ） 及其受体ｕＰＡＲ、１ 型纤溶酶原激活剂抑制剂ＰＡＩ１ 在乳腺肿瘤中的分布及酶学活性。　方法　用免疫组织化学ＡＢＣ方法,分析４ 种因子在乳腺肿瘤组织中的定位及半定量表达,用发色底物法测定乳腺肿瘤组织提取物中的ｔＰＡ 和ｕＰＡ 的活性。　结果　ｔＰＡ、ｕＰＡ、ＰＡＩ１ 主要分布在正常腺上皮及癌上皮细胞的胞质中,ｕＰＡＲ 则在癌细胞的胞膜及胞浆中;总ＰＡ 活性和ｔＰＡ 活性在乳腺良、恶性组织中均无显著性改变,但ｕＰＡ,ｕＰＡＲ 和ＰＡＩ１ 在乳腺癌组织中的表达明显高于良性组织及癌旁组织;ｕＰＡ／ｕＰＡＲ在转移灶中的表达较原发灶有不同程度的下降,而ＰＡＩ１ 在转移灶中却较原发灶中为高。　结论　ｔＰＡ 可能与乳腺癌的恶性表型无关。而ｕＰＡ／ｕＰＡＲ 与恶性表型相关;ｕＰＡ／ｕＰＡＲ 和ＰＡＩ１的相互制约及平衡在调节肿瘤原发灶癌细胞的移动中可能起到重要作用。     

基质降解酶u—PA,PAl—1与人肺癌细胞浸润转移的相关关系的研究

观察体外细胞株ＰＧ，ＰＡａ细胞的ｕ－ＰＡ，ＰＡＩ－１活性和抗原表达，结果发现ＰＧ，ＰＡａ细胞均能够产生ＰＡ及ＰＡＩ，免疫细胞化学法定位ＰＡ主要为ｕ－ＰＡ，ＰＡＩ主要为ＰＡＩ－１，在ＰＧ为ｕ－ＰＡ高表达，而ＰＡａ为低ｕ－ＰＡ表达ＰＡＩ－１在ＰＧ，ＰＡａ细胞听高表达，对ＰＧ瘤细胞在ＢＡＬＢ／ＣＡ裸鼠皮下种植性瘤组织的免疫组化结果显示，ｕ－ＰＡ阳性～强阳性表达，ＰＡＩ－１为阴性表达，说明ｕ－ＰＡ是ＰＧ，     

河南人群中基质金属蛋白酶3 Lys45G1u基因多态性与食管鳞癌遗传易感性的关联分析

Objective  

The aim of the study was to investigate the association of esophageal squamous cell carcinoma (ESCC) genetic susceptibility with the single nucleotide polymorphism (SNP) rs679620 (-Lys45Glu-) in exon 2 of the mmp3 gene, and the population in high incidence region of Henan (China) was selected for exploring the mechanism by case-control study.     

胰腺癌:病理学

Introductions Pancreatic ductal adenocarcinoma (frequently simply being referred to as "pancreatic cancer") represents the most frequent neoplasm of the pancreas, accounting for 85% to 90% of all pancreatic tumors [1, 2].     

胰腺癌:病理学

Introductions Pancreatic ductal adenocarcinoma （frequently simply being referred to as ＂pancreatic cancer＂） represents the most frequent neoplasm of the pancreas, accounting for 85% to 90% of all pancreatic tumors . According to the definition of the World Health Organization , it ＂probably arises from and is phenotypically similar to pancreatic duct epithelia, with mucin production and expression of a characteristic cytokeratin pattern＂.     

Keynote address: hypoxic cell radiosensitizers: where next?

The second generation hypoxic cell radiosensitizers SR 2508 (etanidazole) and Ro 03-8799 (pimonidazole) are now undergoing Phase III clinical trials and are predicted from in vitro, animal, and clinical studies to be equivalent to an increase in the tolerable dose of Miso of 5-6 fold. Nonetheless, this will only produce an SER of the hypoxic cells of approximately 1.5 when given with each dose of a 24 fraction course of radiotherapy. There is ample opportunity, therefore, for a sufficiently improved third generation radiosensitizer to warrant the considerable time, effort, and money that would be involved for its clinical testing. Many groups are now involved in the synthesis and testing of drugs with the goal of producing this third generation sensitizer. The purpose of the present review is to summarize what we have learned from the many studies of new radiosensitizers and attempt to draw conclusions about the most fruitful directions for further work. One of the conclusions is that in vitro testing of radiosensitizers, essential though it is as a first screen, can lead to many false predictions. Fortunately, these in vitro systems tend to "overpredict" (i.e., produce false positives rather than false negatives) for in vivo activity. There is only one class of drugs, so far, (those that increase tumor oxygenation) which radiosensitize tumors in vivo, but not hypoxic cells in vitro. Another major conclusion is that the physico-chemical characteristics of drugs that have been shown to be important in enhancing radiosensitization or reducing toxicity (electron affinity, pKa, partition coefficient, DNA binding), have not been systematically optimized in any one compound. Systematic rational drug design is needed to achieve this. The search for new hypoxic cell radiosensitizers must not detract from the fact that a sensitizer of aerobic cells to low radiation doses is needed. A major challenge in achieving a useful drug for radiotherapy is the desirability for such a drug to be tumor specific. We present data which show that tumor hypoxia might be exploited to achieve this goal.     

ColorectalcarcinomainaSouthernMediterraneancountry:The Libyanscenario

AIM: To study the salient features of colorectal cancer (CRC) in Libya.METHODS: Patients records were gathered at the primary oncology clinic in eastern Libya for the period of one calendar year (2012). Using this data, various parameters were analyzed and age-standardized incidence rates were determined using the direct method and the standard population.RESULTS: During 2012, 174 patients were diagnosed with CRC, 51.7% (n = 90) male and 48.3% (n = 84) females. The average age was 58.7 (± 13.4) years, with men around 57.3 (± 13) years old and women usually 60.1 (± 13.8) years of age. Libya has the highest rate of CRC in North Africa, with an incidence closer to the European figures. The age-standardized rate for CRC was 17.5 and 17.2/100000 for males and females respectively. It was the second most common cancer, forming 19% of malignancies, with fluctuation in ranking and incidence in different cities/villages. Increasingly, younger ages are being afflicted and a higher proportion of patients are among the > 40 years subset. Nearly two-thirds presented at either stage III (22.4%) or IV (38.4%).CONCLUSION: Cancer surveillance systems should be established in order to effectively monitor the situation. Likewise, screening programs are invaluable in the Libyan scenario given the predominance of sporadic cases.     

人物专栏:郑树

ZHENG Shu was born in Hangzhou city of Zhejiang Province. She attended the Zhejiang Medical School from 1949 1955. She received a one-year postgraduate training in surgical pathology in Cancer Hospital of Shanghai First Medical College. She then joined the research group of Professor Fisher Bernard at NSABP Center, University of Pittsburgh,     

肿瘤研究所:任重道远

早在中国医学科学院建院之初,吴桓兴、李冰等创始人就为医院的发展做出了一个非常重要,非常有预见性的决策——开展'综合治疗'。那时,他们还有一个同样重要,同样有预见性的恢弘构想:就是在建立现代化肿瘤专科医院的同时,一定要建立肿瘤研究所,创办研究型医院,医疗与科研并举,走一条可持续发展之路。     

赛勃刀:机器人放疗

赛勃刀由机器手、小型直线加速器、治疗计划系统和图像引导系统组成,其最大特点是该系统以其动态定位软件设计提供了无需定位框架的立体定向放射治疗。患者可在休闲状态下接受治疗,无痛、无创、无出血,疗效好,疗程短,副作用少。     

人物专栏:马军

Ma Jun is the Head of Harbin Institute of Hematology ＆ Oncology that serves as a teaching, research and medical center of hematology and oncology in China. Dr. Ma is a very famous professor of Hematology and Oncology in the county and abroad now. However, Dr. Ma had been a technician of clinical laboratory in 1970-1978. Even though no chance to get normal education in those years, he worked and studied very hard and became self-taught in hematology. He was sent to Japan in 1979-1983, and focused on the study of hematopoietic stem cell, especially on chronic myelogenous leukemia （CML）. He firstly found that there were both normal and abnormal hematopoietic clone exist in the bone marrow of CML, by which the dual clone theory of CML was established later. He first established hematopoietic stem cell culture system in vitro in China after he came back to China in 1984.