Radiotherapy Enhancement with Electroporation in Human Intestinal Colon Cancer HT-29 Cells

Background: The efficiency of radiotherapy for tumors can be enhanced with different radiosensitizers. Previousstudies have shown that electroporation (EP) can sensitize some cancer cell lines to ionizing radiation (IR). HT-29is a radiation resistant colorectal cancer cell line, representative of a cancer type which is the second cause of cancermortalities in developed countries. The present study aimed to evaluate radiosensitizing effects of EP on HT-29 cellsin vitro exposed to 6 MV X-ray photon beams. Methods: HT-29 cells were exposed to a 6 MV X-ray photon beamas the control or to a combination of electroporation and irradiation. The response of cells was evaluated by colonyformation assay and survival curves. Results: The survival fraction of the HT-29 cells was significantly decreased byelectroporation prior to radiotherapy. A single electric pulse increased colorectal HT-29 cancer cell sensitivity to megavoltageradiation by a factor of 1.36. Conclusion: Our findings showed that EP before radiotherapy can significantlyenhance tumor cell sensitivity. This combined treatment modality should be assessed for its applicability in clinic settingsfor employment against radioresistant cancers. However, to facilitate achieving this goal, many different tumors witha broad range of radiosensitivities should be evaluated.     

Clinical symptoms observed in children envenomated by scorpion stings, at the children's hospital from the State of Morelos, Mexico.

Scorpion sting is a public health problem in Mexico (Toxicon, 32 (1994) 1015). Since the most severe cases occur in children, cases treated at the Hospital del Ni?o Morelense, Cuernavaca, during the entire year of 1997 were registered and studied. During this 12-month period, 163 cases required medical attention, with the following results: 45% were mild, 25% moderate and 30% were severe cases of envenoming. Thanks to anti-venom therapy none of the children died. The most frequently observed clinical symptoms were: local pain and redness, salivation, dysphagia, tachycardia, irritability, odynophagia, paresthesia, nasal pruritus and emesis. The mild cases had one or two symptoms, moderate envenoming was characterized by several of the symptoms, whereas severe cases had most of the clinical symptoms listed. The moderate and severe cases were all treated with horse F(ab)2-anti-venom, while the mild cases were kept only for observation. Male children constituted 63% of the cases. The mean time that elapsed between sting and first medical attention was 54min.     

Eclipse最小剂量参数对鼻咽癌调强计划影响的研究

目的:探讨Eclipse鼻咽癌调强计划中最小剂量参数(Minimize dose)对靶区和危及器官受照剂量的影响，为临床计划优化提供参考。方法:运用Varian Eclipse 10.0计划系统回顾性对10例鼻咽癌患者重新设计调强计划，采用相同的约束条件，最小剂量参数分别选取5、8、10、15、20。比较靶区适形度指数和均匀性指数、危及器官照射剂量或受照体积、机器跳数和子野数，并做统计学分析。结果:最小剂量参数由5增大到20，靶区CI减小，HI增大，OARs受照剂量增加。统计学比较显示当最小剂量为8时PCTV1 HI的P值首次小于0.05（P=0.031），差异有统计学意义。当最小剂量大于等于10时全部靶区的CI和HI的P＜0.05，差异有统计学意义。脑干和脊髓从最小剂量参数为10开始P<0.05（P=0.025,P=0.008），统计学比较差异显著。右侧腮腺和下颌骨在最小剂量参数大于等于15时P<0.05（P=0.041，P=0.005），差异有统计学意义。随最小剂量参数的增大，总机器跳数由2 186.3±175.7减少到2 085±149.5，无统计学差异。子野数由1 603.3±278.0减少到1 567.4±270.0，最小剂量参数大于等于10时差异有统计学意义。结论:考虑最小剂量参数对靶区、危及器官、机器跳数和子野数的影响，Eclipse鼻咽癌调强计划中最小剂量参数选择5到8之间是合适的。