氟尿嘧啶及其前体药物去氧氟尿苷的放射增敏作用

氟尿嘧啶类药物作为放射治疗增敏剂用于临床放化疗已取得良好的效果。特别是对腹部恶性肿瘤，氟铁龙是5-氟尿嘧啶的前体药物，具有肿瘤靶向性，在肿瘤中的浓度较高，且可通过口服用药，可作为较好的放射增敏剂，目前已报道口服氟铁龙对胰腺癌、肝直肠癌的放射增敏作用。本文介绍其放射增敏机制、临床前期的实验研究、临床放射增敏及展望。     

化疗药物的放射增敏作用研究进展

放射增敏剂一直是放射肿瘤学研究的课题,虽然已发现许多药物有放射增敏作用,但多数实用价值不大,细胞毒性化疗药物在临床上与放疗同时应用显示出协同和放射增敏作用,化疗药物作为一种放疗增敏剂已得到了广泛的研究和应用.     

放射增敏剂研究进展

放射增敏剂是指那些能使电离辐射的生物效应增强物质，临床上可用于增射线对肿瘤的杀伤能力，固而在肿瘤的放射治疗中具有很大的应用价值，越来越受到国内学者的重视。已选后合成并筛选出ＭＩＳＯ等管氧细胞放射增敏剂，对具有放射增敏 性的生物还原剂及合并用药等方面也进行了研究。     

肿瘤放射增敏剂及增敏机制研究进展

放射增敏剂是指能增强射线对肿瘤内乏氧细胞的杀灭作用而对有氧的正常组织一般损伤较小的一些化学物质.本文主要介绍了放射增敏剂的研究进展.从影响肿瘤放射敏感性因素入手,详细叙述了放射增敏剂的种类、主要作用机制和发展趋势.     

肼苯哒嗪诱导肿瘤内乏氧以提高放疗和化疗的治疗增益

目前,临床上对放射增敏剂MISO与RSU-1069正深入地进行研究,减少对正常组织的损伤,加强放射增敏效力。我们尝试改变肿瘤内血流,造成肿瘤内全部乏氧,以便利用放射增敏剂在乏氧与有氧状态下的不同毒性。结果证明,控制肿瘤内血流,可提高放射增敏剂的效力,并能增加化疗药物的细胞毒性。 RSU-1069是MISO的衍生物,含重氮基团的烷化剂,其结构式为:     

化疗药物的放射增敏作用研究进展

放射增敏剂一直是放射肿瘤学研究的课题，虽然已发现许多药物有放射增敏作用，但多数实用价值不大，细胞毒性化疗药物在临床上与放疗同时应用显示出协同和放射增敏作用，化疗药物作为一种放疗增敏剂已得到了广泛的研究和应用。     

912放射增敏临床观察

放疗因乏氧细胞的存在,常导致肿瘤复发,放射增敏剂的研究一直是人们探索的课题,作为乏氧细胞增敏剂的Misa有其独特的增敏效果,但因合成困难及神经毒性限制其临床应用。西安第四军医大学研制的中药912,进行放射增敏临床研究。我科自1988年9月～1990年4月应用912作为放射增敏剂治疗各种肿瘤163例。用药组93例,对照组70例,因观察时间尚短,本文仅对疗后近期疗效进行观察。     

恶性肿瘤放射增敏中药的研究

本文综述了放射增敏中药筛选途径及药物特点、放射增敏中药对肺癌、鼻咽癌、食管癌的治疗作用及其可能机制等近20年的研究成果;指出了这些研究仍较粗糙、结果只是初步、研究尚待深入;介绍了放射增敏中药研究的趋势是亲肿瘤增敏剂及多功能增敏剂.     

肿瘤放射增敏剂及增敏机制研究进展

放射增敏剂是指能增强射线对肿瘤内乏氧细胞的杀灭作用而对有氧的正常组织一般损伤较小的一些化学物质。本文主要介绍了放射增敏剂的研究进展。从影响肿瘤放射敏感性因素入手,详细叙述了放射增敏剂的种类、主要作用机制和发展趋势。     

多聚腺苷酸二磷酸核糖转移酶抑制剂的放射增敏作用及机制研究

放疗是恶性肿瘤的主要治疗手段之一,临床上约70%的恶性肿瘤患者在治疗不同阶段需接受放疗。多种细胞毒药物被用于放疗联合治疗以增加对肿瘤的治疗疗效,如氟尿嘧啶、顺铂、卡铂和丝链霉素C等,然而它们往往在增加肿瘤细胞杀伤的同时也加重了正常组织损伤,因此寻找特异性针对肿瘤的放射增敏剂是放疗研究的方向。近年来针对多聚腺苷酸二磷酸核糖转移酶\[poly(ADP-ribose) polymerase,PARP\]这一修复蛋白的一些研究提示它可能是有效的肿瘤治疗靶点。由于细胞的损伤修复也是影响放射敏感性的重要因素之一,PARP也是放射增敏的潜在靶点,因此对PARP抑制剂(PARP inhibitor,PARPi)的放射增敏作用及其机制进行综述。     

Bacteria and cancer--antagonisms and benefits

There is considerable historical and recent evidence concerning the antagonisms between acute bacterial infections or their toxins and cancer and allied diseases. These data provide renewed incentives to undertake clinical programmes with mixed bacterial vaccines in many countries at the present time.     

Religiosity and physical and emotional functioning among African American and White colorectal and lung cancer patients

The literature suggests that religiosity helps cope with illness. The present study examined the role of religiosity in functioning among African Americans and Whites with a cancer diagnosis. Patients were recruited from an existing study and mailed a religiosity survey. Participants (N = 269; 36% African American, 56% women) completed the mail survey, and interview data from the larger cohort was utilized in the analysis. Multivariate analyses indicated that in the overall sample religious behaviors were marginally and positively associated with mental health and negatively with depressive symptoms. Among women, religious behaviors were positively associated with mental health and negatively with depressive symptoms. Religiosity was not a predictor of study outcomes for men. Among African Americans, religious behaviors were positively associated with mental health and vitality. Among Whites, religious behaviors were negatively associated with depressive symptoms. These findings suggest a mixed role of religious involvement in cancer outcomes. The current findings may have applied potential in the areas of emotional functioning and depression.     

VEGF及KDR在大肠腺瘤和腺癌中的表达及意义

目的：探讨VEGF和KDR在大肠腺瘤和大肠腺癌中的表达及临床病理特征的关系。方法：大肠腺瘤和大肠腺癌组织标本各100例,采用免疫组织化学染色法检测VEGF和KDR在标本中的表达情况。结果：VEGF和KDR在大肠腺癌组中的阳性表达明显高于大肠腺瘤组（P〈0.05）;在正常大肠黏膜均未见VEGF和KDR表达的阳性染色;VEGF阳性表达组中KDR的阳性表达率为70%,显著高于VEGF阴性表达组中KDR的阳性表达率16%,两组比较有统计学意义（P〈0.01）。结论：大肠腺癌组织中KDR的表达与肿瘤大小、转移情况、浸润深度密切相关;VEGF和KDR在大肠腺瘤中的表达与患者的年龄、性别及分型均无相关性,而与增生程度相关（P〈0.05）。在大肠腺癌患者中VEGF及KDR表达更高,二者具有协同效应。     

Renal irradiation and the pharmacology and toxicity of methotrexate and cisplatinum

We used a rat model to study the effects of renal irradiation on the pharmacology of methotrexate (MTX) and cisplatinum (cis-Pt). Unanesthetized rats were given bilateral kidney irradiation (20 Gy in 9 fractions). At 9 months after irradiation, 3% of the animals had died and survivors showed moderately impaired renal function. At 15 months, 30% of the animals had died and survivors showed severely impaired renal function. Some animals were given i.v. MTX 1 week to 15 months after irradiation. In irradiated rats, the area under the MTX plasma clearance curve equaled that of controls through 6 months, and was significantly above controls from 9 months on. Other animals were given i.p. cis-Pt 1 week to 9 months after irradiation. The acute toxicity of cis-Pt was the same in control and irradiated rats when cis-Pt was given immediately before or after irradiation. Beginning 3 months after irradiation there was a progressive increase in cis-Pt toxicity and a simultaneous decrease in urinary platinum excretion. Irradiated animals that survived cis-Pt treatment showed increased radiation nephritis; the greatest effect occurred when cis-Pt was given 3 months or more after irradiation. MTX and cis-Pt clearance decreased when renal dysfunction was first observed and changes in renal function preceded changes in drug clearance and toxicity.     

Fruit and vegetables and cancer risk

The possibility that fruit and vegetables may help to reduce the risk of cancer has been studied for over 30 years, but no protective effects have been firmly established. For cancers of the upper gastrointestinal tract, epidemiological studies have generally observed that people with a relatively high intake of fruit and vegetables have a moderately reduced risk, but these observations must be interpreted cautiously because of potential confounding by smoking and alcohol. For lung cancer, recent large prospective analyses with detailed adjustment for smoking have not shown a convincing association between fruit and vegetable intake and reduced risk. For other common cancers, including colorectal, breast and prostate cancer, epidemiological studies suggest little or no association between total fruit and vegetable consumption and risk. It is still possible that there are benefits to be identified: there could be benefits in populations with low average intakes of fruit and vegetables, such that those eating moderate amounts have a lower cancer risk than those eating very low amounts, and there could also be effects of particular nutrients in certain fruits and vegetables, as fruit and vegetables have very varied composition. Nutritional principles indicate that healthy diets should include at least moderate amounts of fruit and vegetables, but the available data suggest that general increases in fruit and vegetable intake would not have much effect on cancer rates, at least in well-nourished populations. Current advice in relation to diet and cancer should include the recommendation to consume adequate amounts of fruit and vegetables, but should put most emphasis on the well-established adverse effects of obesity and high alcohol intakes.     

New and emerging radiosensitizers and radioprotectors

The combination of chemotherapy and radiation has led to clinical breakthroughs in several disease sites, and current work continues to define optimum combinations of proven chemotherapy as well as more recently available, noncytotoxic agents. Administration of systemic therapies allows modulation of radiation response to improve tumor control (radiosensitization) or to prevent normal tissue toxicity (radioprotection). Substantial progress has been made in identifying the targets of standard chemotherapeutic radiation sensitizers and protectors as well as in the introduction of a new generation of molecularly targeted therapies in combination with radiation. We have reviewed the most recent, predominantly early phase clinical trials combining systemic agents with radiation. Although the proof of an improved schedule ultimately needs to come from well-run Phase III trials, the search among schedules could be shortened by the use of surrogate endpoints such as presence of active drug metabolites in the tumor. This has been accomplished only in a few cases and needs to become a more standard part of radiation sensitizer and protector trials.