低聚壳聚糖对60Co辐射损伤小鼠骨髓的防护作用研究

壳聚糖是从甲壳类动物、蘑菇及细菌细胞壁中提取的一种多糖类生物活性物质,有明显的消除自由基、保护机体免受电离辐射损伤的作用。它可明显提高动物的存活率,具有一定的抗辐射作用^[1-2]。对其作用机理的研究将有助于辐射防护药物的筛选、配伍等研究。本研究旨在探讨低聚壳聚糖抗辐射药效以及辐射生物效应机制,以期为辐射损伤个体防护提供参考。     

辐射生物剂量估算工具BioDoser软件的设计和应用

生物剂量估算是指建立剂量和不确定性因素间的联系,这就需要用数学算法将实验数据拟合成数学曲线,再进行估算分析。人离体外周血辐射实验能够较好地反映人体电离辐射损伤情况^[1]。因此,实验室建立的外周血辐射生物剂量-效应曲线常用于辐射事故后剂量评估。染色体畸变实验、微核实验、单细胞凝胶电泳和淋巴细胞计数等是辐射剂量估算的常用手段,其相关剂量效应曲线拟合的精确度尤为重要。本研究通过计算机语言VC和相关拟合算法编写了新的辐射生物剂量估算软件BioDoser,旨在提高剂量估算的效率和精确度。     

辐射生物剂量计的研究现状及发展方向

辐射生物剂量学是放射医学的重要组成部分。近年来,辐射生物剂量研究取得一些新进展,为研发新一代剂量计奠定技术基础。以染色体畸变分析为代表的细胞遗传学方法作为辐射生物剂量估算的金标准方法,正向自动化、网络化分析发展,相关技术已通过国际和国家性的辐射生物剂量实验室网络辐射扩散。γ-H2AX作为DNA损伤的标志性分子,用于放射损伤剂量估算的研究进展较快,其作为放射损伤分子标志物逐步获得国内外的广泛共识。在蛋白分子和表达基因的基础上,代谢物和miRNA作为放射损伤标志物的研究有进一步的新进展。组学技术的发展,推动了利用多分子表达谱评估受照剂量的研究,亦已取得突破。本文从现有辐射生物剂量计的技术特点、国内外的主要发展趋势和今后发展方向展望等3个方面进行综述。     

1980年以来国外抗辐射药物研究概况

抗辐射药物亦称辐射防护剂,系指辐射损伤的防治药物,因此前一称谓似更确切,相当于抗肿瘤、抗菌、抗疟药物等的含义.     

创伤救治中的医源性辐射损伤

放射学检查在创伤救治中具有重要价值,能够快速准确地评估病情和指导临床决策,进而改善救治效果,但检查过程暴露的电离辐射会增加患者肿瘤发生的风险。研究显示目前医务人员对于医源性辐射损伤的认识并不充分,创伤救治中有过度使用放射学检查的趋势。临床医师、放射科医师、设备研发与制造人员、受检者及政府卫生监管部门应共同承担责任,积极采取有效措施,发挥放射学检查作用的同时,力争把伤员辐射暴露降到最低。     

辐射物理学与辐射研究

简要介绍第十届国际辐射研究大会有关生物物理模型,俄偈电子在辐射损伤、放射治疗和辐射防护中的应用,国际辐射单位和测量委员会对辐射研究有关的研究计划等信息。     

绿茶多酚等五种抗辐射药物对质粒pBR322DNA辐射损伤防护效应的研究

绿茶多酚等五种抗辐射药物对质粒ｐＢＲ_（３２２）ＤＮＡ辐射损伤防护效应的研究周丽君，方允中，章扬培，魏康，杨贤强电离辐射损伤等多种疾病的发生、发展都与氧自由基有关，清除氧自由基的措施将有益于这些疾病的预防和治疗［１］。绿茶多酚是茶叶中提纯的新食物添加?..     

舰船核辐射医学防护技术与装备研究进展

舰艇核辐射医学防护技术与装备,主要包括核辐射监测技术与装备、核辐射防护技术与装备、小剂量辐射生物效应及防护技术、核辐射损伤伤员的医学监测及药物防治等。     

将传统MRI的软骨下小梁生物标志物作为膝关节骨性关节炎进展的预测因子:数据来自骨关节炎指南

正摘要目的评估"常规"中间加权(IW) MRI 序列测量软骨下小梁生物标志物的可靠性和有效性,并评估生物标志物的改变对预测膝关节骨性关节炎(OA)近期症状和结构进展     

国外海军医学动态系列讲座(12)舰船核辐射医学防护技术与装备研究进展

舰艇核辐射医学防护技术与装备,主要包括核辐射监测技术与装备、核辐射防护技术与装备、小剂量辐射生物效应及防护技术、核辐射损伤伤员的医学监测及药物防治等.     

表没食子儿茶酸没食子酸酯用于放射损伤防治的研究进展

放射治疗是治疗恶性肿瘤的主要手段之一,在治疗过程中易引起正常组织的损伤,如放射性肺损伤、食管损伤、皮肤损伤及造血、免疫功能异常等。绿茶成分表没食子儿茶酸没食子酸酯（EGCG）是茶多酚的主要成分,具有抗炎、抗氧化、抗凋亡及调节免疫力等功能。近年来大量的动物模型实验证实,EGCG具有防治放射损伤的作用,但EGCG防治放射损伤的临床报道不多。本文将从EGCG的抗放射机制及其在放射性损伤中的应用方面,对近年来EGCG在放射损伤防治方面的研究进展进行综述,以期为EGCG的临床应用提供参考。     

辐射防护药物研究最新进展

电离辐射损伤不仅是一个公众健康问题,同时也是一个国家安全问题。如何获得治疗效果优良、安全性高和不良反应小的辐射防护药物一直是科学家努力研究的目标。近年来,伴随着分子生物学、免疫学等学科的发展,辐射防护药物的研究也取得了较大的突破。目前,诸如5-雄烯二醇（5-AED）、CBLB502、Ex-RAD和HemaMax等药物已获得美国食品药品监督管理局的批准进入临床试验;而新发现的具有潜在价值的LY294002和17-DMAG等药物也正处于研发之中。笔者基于近年来辐射防护领域国外相关刊物和专利的最新发现和进展进行综述。重点放在近几年来出现的药物新进展以及这一时间内治疗急性放射综合征的抗辐射新药上。     

蛋白标志物在辐射损伤中的应用

机体暴露于电离辐射下,一系列分子表达活性将发生变化,特异性改变的蛋白质可作为标志物用于辐射损伤的鉴别分类、治疗防控以及动态观察.该文综述了目前已经确定的或具有潜在功能的数种辐射损伤蛋白标志物的应用价值,介绍了多种蛋白标志物综合分析用于辐射损伤的诊断和治疗的目前研究进展.     

The radiation biology of radioimmunotherapy

The treatment of cancer is a wide and varied field, encompassing many methods and modalities. Radioimmunotherapy is a technique which utilizes the ablative properties of radiation by delivering radioactive particles directly to the tumour cells. This paper presents a summary of the research evidence that relates to the optimization of the effect of radioimmunotherapy. It includes discussion on the appropriate choice of radionuclide and monoclonal antibody; methods of increasing the radiation dose absorbed by the tumour; techniques available to increase the effect that the absorbed dose has on the tumour; and methods of protecting critical healthy tissue, particularly the bone marrow, from the effects of the radiation administered.     

Experimental studies concerning comparison of the effect on the intestine between antitumor agents and radiation

Though radiotherapy combined with chemotherapy is used increasingly more frequently in the recent treatment of malignant tumors, very little is known about what dose of an antitumor agent equals what radiation dose in effect. We tried to determine those radiation doses which are required to produce the same effect as certain specific doses of antitumor agents (isoeffective dose) by studying the early effects of radiation and drugs chiefly on the intestine of dd strain mice. Parameters used were food consumption, body weight change, 3H-TdR radioactivity in the intestine and the labelling index of intestinal crypt cells. The results were as follows: 1) To determine that radiation dose which is equal to a drug dose (1/2 its LD50) in systemic effect, body weight change and food consumption were suggested to be useful parameters. 2) To determine that radiation dose which is equal to a drug dose in the effect on a specific organ, parameters suitable for the target cells must be selected. For evaluating the effect on the intestine, the labelling index of intestinal epithelium was a useful parameter. 3) The results of treatment with combined radiation and slight amounts of drugs suggested that the degree of aggravation of radiation injury due to drugs might vary with the time of drug administration. 4) Graphic representation of the severity of injury as indicated by parameters enabled us to grasp visually the characteristics of drugs.     

Deoxyribonucleic acid damage-associated biomarkers of ionising radiation: current status and future relevance for radiology and radiotherapy

Diagnostic and therapeutic radiation technology has developed dramatically in recent years, and its use has increased significantly, bringing clinical benefit. The use of diagnostic radiology has become widespread in modern society, particularly in paediatrics where the clinical benefit needs to be balanced with the risk of leukaemia and brain cancer increasing after exposure to low doses of radiation. With improving long-term survival rates of radiotherapy patients and the ever-increasing use of diagnostic and interventional radiology procedures, concern has risen over the long-term risks and side effects from such treatments. Biomarker development in radiology and radiotherapy has progressed significantly in recent years to investigate the effects of such use and optimise treatment. Recent biomarker development has focused on improving the limitations of established techniques by the use of automation, increasing sensitivity and developing novel biomarkers capable of quicker results. The effect of low-dose exposure (0–100 mGy) used in radiology, which is increasingly linked to cancer incidences, is being investigated, as some recent research challenges the linear-no-threshold model. Radiotherapy biomarkers are focused on identifying radiosensitive patients, determining the treatment-associated risk and allowing for a tailored and more successful treatment of cancer patients. For biomarkers in any of these areas to be successfully developed, stringent criteria must be applied in techniques and analysis of data to reduce variation among reports and allow data sets to be accurately compared. Newly developed biomarkers can then be used in combination with the established techniques to better understand and quantify the individual biological response to exposures associated with radiology tests and to personalise treatment plans for patients.Research into the identification of biomarkers of radiation exposure is an emerging and developing area with multiple possible benefits for patients, doctors and the general public. A radiation biomarker is a biological entity that changes after exposure to radiation, allowing exposed individuals to be identified and, with some biomarkers, a dose to be estimated. There are different types of biomarkers, including chromosome aberrations, protein expression or gene expression. Some can measure accurately the dose received, while others can only indicate if a dose was received. Biomarkers can help clinicians manage treatment for a patient exposed accidentally to the wrong radiation dose or on purpose through radiotherapy. They may be able to predict the treatment response of a tumour and estimate the risk of acute or late effects in normal tissues. Biomarkers can also identify the dose received by the patient in a full or partial body exposure. Such information can help inform the necessary medical treatment plan for the patient, and it may also identify patients with a high likelihood of developing cancer in the future so that regular monitoring can be set up.     

Neutron dosimetry in a model of the body's inhomogeneities using the TLD-300 detector

The modification of the absorbed dose distribution due to the presence of inhomogeneities in the human body requires thorough research within the scope of radiation treatment planning for tumour therapy with fast neutrons. In this work the effect of air and lung cavities and the depth dose distribution in the near and distant vicinity of the inhomogeneity is studied. By means of thermoluminescence detectors TLD-300 the total absorbed dose is measured in mixed neutron-photon radiation fields in the used polystyrene phantom with embedded inhomogeneity. Lung tissue is simulated by cork. Differences in the concentration of hydrogen between inhomogeneity and surrounding soft tissue lead to new build-up effects. These cause an increase behind and a decrease of the total dose beside and in front of the inhomogeneity. In case of the cork inhomogeneity an absorbed dose increase of maximally 20% in comparison to the absorbed dose in the homogeneous phantom was found. With air as inhomogeneity the increase of absorbed dose reaches a maximum of 30% compared to the homogeneous phantom.     

The evidence base for the use of internal dosimetry in the clinical practice of molecular radiotherapy

Molecular radiotherapy (MRT) has demonstrated unique therapeutic advantages in the treatment of an increasing number of cancers. As with other treatment modalities, there is related toxicity to a number of organs at risk. Despite the large number of clinical trials over the past several decades, considerable uncertainties still remain regarding the optimization of this therapeutic approach and one of the vital issues to be answered is whether an absorbed radiation dose–response exists that could be used to guide personalized treatment. There are only limited and sporadic data investigating MRT dosimetry. The determination of dose–effect relationships for MRT has yet to be the explicit aim of a clinical trial. The aim of this article was to collate and discuss the available evidence for an absorbed radiation dose–effect relationships in MRT through a review of published data. Based on a PubMed search, 92 papers were found. Out of 79 studies investigating dosimetry, an absorbed dose–effect correlation was found in 48. The application of radiobiological modelling to clinical data is of increasing importance and the limited published data on absorbed dose–effect relationships based on these models are also reviewed. Based on National Cancer Institute guideline definition, the studies had a moderate or low rate of clinical relevance due to the limited number of studies investigating overall survival and absorbed dose. Nevertheless, the evidence strongly implies a correlation between the absorbed doses delivered and the response and toxicity, indicating that dosimetry-based personalized treatments would improve outcome and increase survival.     

Dosimetric evaluation and therapeutic response to internal radiation therapy of hepatocarcinomas using iodine-131-labelled lipiodol

OBJECTIVE: Vectorized internal radiation therapy using lipiodol-labelled with iodine-131 (131 I-lipiodol) is an effective treatment for inoperable hepatocellular carcinomas. However, few dosimetric data are available based on this approach. We have developed a dosimetric protocol based on scintiscan imaging and that is designed to calculate the tumoural absorbed dose during the treatment of hepatocarcinoma by 131 I-lipiodol. METHODS: This concept was developed on a gamma-camera coupled to a computed tomography scanner. It integrates corrections for attenuation phenomena, scattering and dead time. The tumoural absorbed dose calculation was carried out according to the Medical Internal Radiation Dose Committee formalism. This protocol was applied to a series of 41 patients in the framework of a retrospective study. RESULTS: The mean tumoural absorbed dose with the first treatment is 248 Gy (+/-176), as opposed to 152 Gy (+/-122) during the second. We highlighted a correlation between the tumoural absorbed dose, calculated in tomographic mode, and the morphological response to the first treatment (P=0.0071). Moreover, a tumoural absorbed dose of 280 Gy seems to be an effective absorbed dose threshold in our population. Above this absorbed dose, 84% of the patients are responders after the first treatment, whereas no responses are recorded below this threshold. CONCLUSION: These results are promising because, for the first time, they allow us to predict the effectiveness of a treatment by 131 I-lipiodol. They are required to be validated on a broader exploratory trial, including a dosimetric study of the critical organs, so an individualized dosimetry can be defined for each patient.