ABSTRACT
The purpose of this paper is to establish an easy and reliable biodosimeter protocol to evaluate the biological effects of proton beams. Human peripheral blood lymphocytes were irradiated using proton beams [LET: 34.6 keV micro m[-1]], and the chromosome aberrations induced were analyzed using cytokinesis-blocked [CB] micronucleus [MN] assay. To determine the efficiency of MN assay in estimating the doses received by 50MeV proton beams and to monitor predicted dose of victims in accidental exposure, here we have evaluated the performance of MN analysis in a simulated situation after exposure with proton beams. Peripheral lymphocytes were irradiated by 50MeV proton beams up to 6Gy and analyzed by Giemsa staining of CB MN assay. The detected MN was found to be a significant dose-effect curve in the manner of dose-dependent increase after exposure with proton beams in vitro. When plotting on a linear scale against radiation dose, the line of best fit was Y=0.004+[1.882x10[-2] +/- 9.701x10[-5]] D+[1.43x10[-3] +/- 1.571x10[-5]]D2. Our results show a trend towards increase of the number of MN with increasing dose. It was linear-quadratic and has a significant relationship between the frequencies of MN and dose [R2= 0.9996]. The number of MN in lymphocyte that was observed in control group is 5.202 +/- 0.04/cell. Hence, this simple protocol will be particularly useful for helping physicians to decide medical therapy for the initial treatment of victims with rapid and precise dose estimation after accidental radiation exposure. Also it has potential for use as a valuable biomarker to evaluate the biological effectiveness for cancer therapy with proton beams
Subject(s)
Humans , Protons , Dose-Response Relationship, Radiation , Radiation DosageABSTRACT
Antioxidants oppose the toxic actions of lipid peroxides and oxygen radicals, and they limit the amount of lipid peroxides formed. Women with normal pregnancies have an increase in oxidative stress and lipid peroxidation when compared with nonpregnant women. The antioxidants also increase progressively with advancing gestation, and the antioxidants in the fetus also increase with advancing gestation, especially during late gestation. The purpose of this study is to investigate the diefference of antioxidant status in maternal and neonatal plasma according to the delivery type. So, we investigated the status of antioxidant in the maternal and neonatal plasma when compared normal vaginal delivery with Cesarian section without labor. This study was done under the hypothesis that labor pain is originated from the hypoxic state of myometrium during uterine contraction. The number of women who were studied was total 56, 24 women were delivered by normal vaginal delivery and 32 women were done by Cesarean section without labor. The blood was sampled during active labor and postpartum 24 hour in the case of normal vaginal delivery, the women who were done Cesarean section being sampled before operation and 24 hours after operation. The neonatal blood was sampled from cord, birth 1 day and 3 day. The antioxidant levels were measured by Total Antioxidant Status (Randox Laboratory Ltd., UK) kit. The results were as follows. 1. The mean maternal plasma antioxidant status was not significantly different according to delivery types and not significantly different when compared antepartum with postpartum (vaginal delivery; antepartum: 1.54+/-0.31 mM/L, postpartum: 1.58+/-0.32 mM/L, Cesarean section; antepartum: 1.55+/-0.29 mM/L, postpartum: 1.56+/-0.33 mM/L). 2. The neonatal antioxidant status was not significantly different between the neonates who were born by vaginal delivery and the neonates who were born by Cesarean section. The neonatal plasma antioxidant status was increased progressively after birth (cord: birth 1 day: birth 3 day=1.46+/-0.25 mM/L: 1.59+/-0.25 mM/L: 1.79+/-0.37 mM/L). Therefore, labor pain was not seems to be significantly affect the maternal and neonatal plasma antioxidant status. And the neonatal antioxidant status was increased for adaptation to the external environment after birth.