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رکورد قبلیرکورد بعدی
نوع مدرک : TF
زبان مدرک : فارسی
شماره رکورد : 66807
شماره مدرک : ‭پ۵۳۳۵۲‬
شماره راهنما : ‭آ۳۷۴‬
سر شناسه : کامران سامانی، رقیه
عنوان اصلي : ارزیابی تاثیر تقطیع دز بر میزان اثر همسایگی پرتوی
نام عام مواد : [پایان‌نامه]
نام نخستين پديدآور : /رقیه کامران سامانی
نام ساير پديدآوران : ؛استاد راهنما: محمد تقی بحرینی طوسی، شکوه الزمان سلیمانی فرد
عنوان ديگر : عنوان به انگلیسی‭An assessment of dose fractionation on the level of bystander effect induced by radiation :‬
وضعيت نشر : دانشگاه علوم پزشکی مشهد، ‭۱۳۹۱‬، دانشکده پزشکی
صفحه شمار : ‮‭[۱۵۴]‬ ص.‬: نمودار
يادداشت : چکیده فارسی، چکیده انگلیسی
يادداشت : چاپی
خلاصه يا چکيده : ‭DB, MRC5 -M group). Keywords: Radiation induced Bystander effect, Dose fractionation, Medium transfer, Micronucleuse (MN) assay, QU-Q and 2 to 4 Gy in Q-Q group). However when the dependency of bystander effect on dose is reversed, fractionation increased the effect (the dose of 6 to 8 Gy in Q-M, the number of MNed cells in 100, 200 and 400cGy single exposure were equal. Also in this group there was no significant difference between subgroups which received single or fractionated exposures (P=1). Conclusion: Our results showed when the bystander effect was saturated in a limited level, fractionation of exposure had no effects on the level of bystander effect, and the effect was not repeated as a result of a new radiation, but when the bystander effect increases with increasing radiation dose, fractionation decreased the bystander effect (the dose of 2 to 4 Gy in Q-M group, 200cGy single and 200cGy fractionated exposures (2(100) cGy) had same effects but 2(200) cGy was more effective than 400cGy exposure (P < 0.01). In group M-value =0.082). The number of MNed cells in 800cGy fractionated dose (2(400)) and 400 cGy were equal and both of them were more than 800cGy.In Q-Q for 400cGy fractionated exposure (2(200) cGy) is more than 200 cGy but less than 400 cGy. There was no significant difference between 600, 2(300) and 3(200) cGy (p-block micronucleous assay was performed to detect the damages induced in bystander cells. Results: The number of micronucleated (MNed) cells in 1000 binucleated (BN) bystander cells in group Q-M which media of MRC5 target flasks was transferred to hemogeneous bystander flasks. The target cells were irradiated with gamma rays emitted from a 60Co radiotherapy unit. The cytokinesis-M group) and group M-DB target flasks were transferred to MRC5 bystander flasks (Q-Q group). In second group media of QU-DB cells (Q-DB cells were irradiated and their medium transferred to QU-induced bystander effect is referred to the effects induced in cells that are not actually exposed by ionizing radiation, but are affected by bystander signals emitted from irradiated cells. Due to the existence of bystander effect in high dose radiation, it is not surprising that clinical radiotherapy is affected by this phenomenon. Most radiotherapy schedules use some forms of dose fractionation to protect irradiated normal tissues, but it is possible that the dose fractionation increases this effect on bystander healthy tissues. The aim of this study was to evaluate and compare the level of bystander effect due to fractionated and single dose irradiation. Method: Medium transfer technique was used to produce the bystander effect. In fractionation protocol, target cells were irradiated in two or three equal fractions with 6 hours interval. We had three main groups. In first group QU-Background: Radiation‬
 
 
 
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