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پرتوپژوه Iranian Journal Of Radiation Research فصلنامه داراي رتبه علمی - پژوهشی (پزشکي) به زبان انگليسي سال هفتم، شماره 1 (پياپي 25)، بهار 1388

	Concentration of radon، thoron and their progeny levels in different types of floorings، walls، rooms and building materials L.A. Sathish ، K. Nagaraja، H.C. Ramanna، V. Nagesh، S. Sundareshan Page 1 (انگليسي) Abstract مشاهده متن [PDF 375KB]
	Background: Radon، thoron and their progenies are the most important contributions to human exposure from natural sources. Radon exists in soil gas، building materials، Indoor atmosphere etc. Among all the natural sources of radiation dose to human beings، inhalation of radon contributes a lot. The work presented here emphasizes the long term measurements of radon، thoron and their progeny concentrations in about 100 dwellings using solid state nuclear track detectors. Materials and Methods: Measurements were made using dosimeters and the concentrations were estimated by knowing the track density of films through spark counter، and sensitivity factor for bare، filter and membrane films. Results: Presence of radon and thoron in houses is the effect of several aspects such as the activity concentrations of uranium، radium and thorium in the local soil، building materials، ventilation of houses and also entry of radon into houses through the cracks in floor/wall. Conclusion: The observations reveal that the concentrations of radon and/or thoron are relatively higher in granite than in concrete، cement and bricks. In continuation to this the concentration observed in bathrooms is more compared to kitchen، bedroom and living rooms. This study discloses that the residential rooms of good ventilation will avoid the health hazards due to radon and its rich materials. Keywords: SSNTDs ، radon ، thoron ، dosimeter ، building materials

	Rheological properties of blood after whole body gamma-irradiation N.S. Selim، O.S. Desouky ، S.M. El، Marakby، I.H. Ibrahim، H.A. Ashry Page 11 (انگليسي) Abstract مشاهده متن [PDF 326KB]
	Background: The study of rheological properties of blood has special interest; since it is a circulating fluid exposed to shear rates during its life time. This work aims to investigate the influence of whole body gamma irradiation on the rheological properties of rat’s blood. The applied shear rate was from 12 to 375 s-1. Low shear viscosity (up to 100 s-1) depends mainly on the erythrocytes aggregation while the high shear viscosity depends on the erythrocytes deformability. Materials and Methods: Adult male rats were exposed to 1، 2.5، 3.5، 5، 7 and 9 Gy single doses. The consistency index، apparent viscosity، yield stress and aggregation index were increased after exposure to gamma radiation. The dielectric properties of the erythrocytes، in the low frequency range (60 Hz to 40 kHz)، were measured in order to investigate the changes in the membrane surface charge. Results: The results obtained indicate that the viscosity، consistency index and yield stress increased after the exposure to the lowest dose taken; 1 Gy، and continued to increase as the exposure dose increased up to dose 7 Gy and then decrease after exposure to 9 Gy. The relative permittivity and relaxation time showed significant decrease after exposure to the lowest dose and continue to decrease as the dose increased. Conclusion: The obtained results can be attributed to the decrease of membrane surface charge after exposure to gamma radiation. The decrease in the membrane surface charge is known to decrease the repulsion between the cells and increase blood viscosity. Keywords: Rheological properties ، erythrocytes ، gamma Radiation ، aggregation

	The role of Rad51 protein in radioresistance of spheroid model of DU145 prostate carcinoma cell line M. Taghizadeh ، S. Khoei ، A.R. Nikoofar ، L. Ghamsari ، B. Goliaei Page 19 (انگليسي) Abstract مشاهده متن [PDF 302KB]
	Background: Rad51 is a protein with critical role in double strand break repair. Down-regulation of this protein has a significant effect in radiosensitivity of some cell lines like prostate carcinoma. Compared to monolayer cell culture model، the spheroids are more resistant to radiation. The aim of the current study was to determine the Rad51 protein level in DU145 spheroids، and monolayer cells before and after exposure to gamma irradiation. Materials and Methods: In the present study، western blot was used to determine the level of Rad51 protein in DU145 cell line grown as monolayer and spheroid. Results: Western blot analysis showed that in the spheroid cells، Rad51 had an elevated level before and after radiation in comparison with monolayer cells. Higher doses of radiation induced elevated expression of Rad51 protein in both culture models. The level of at protein after exposure to gamma rays had been timedependent. Conclusion: Rad51 might act as a mediator of radiation resistance in tumor cells. Repression of Rad51 activity could be a prominent strategy to overcome radiation resistance of tumors. Keywords: Multicellular spheroid ، radioresistance ، DU145 prostate carcinoma cell line ، rad51

	Effect of low dose gamma-radiation upon Newcastle disease virus antibody level in chicken M. Vilić ، Ž. Gottstein، I. Ciglar Grozdanić، K. Matanović، S. Miljanić، H. Mazija، P. Kraljević Page 27 (انگليسي) Abstract مشاهده متن [PDF 340KB]
	Background: The specific antibody response against Newcastle disease virus (NDV) in the blood serum of chickens hatched from eggs exposed to low dose gamma-radiation was studied. Materials and methods: Two groups of eggs of commercial meat chicken lines were irradiated with the dose of 0.30 Gy 60Co gamma-rays before incubation and on the 19th day of incubation، respectively. The same number of eggs unexposed to gamma-radiation served as controls. After hatching the group of chicken hatched from eggs irradiated on the 19th day of incubation was not vaccinated while the group of chicken hatched from eggs irradiated before incubation was vaccinated on the 14 day. Specific serum anti-NDV antibodies were quantified by the hemagglutination inhibition assay with 4 HA units of NDV La Sota strain. Result: Specific antibody titres against NDV in the blood serum of chickens hatched from eggs irradiated before incubation and vaccinated on the 14th day significantly increased on the 28th day. Specific antibody titre against NDV in the blood serum of chickens hatched from eggs irradiated on the 19th day of incubation and non-vaccinated was significantly higher on the 1st and 14th day. Conclusion: Acute irradiation of heavy breeding chicken eggs with the dose of 0.30 Gy 60Co gammarays before incubation and on the 19th day of incubation could have a stimulative effect on humoral immunity in chickens. Keywords: Gamma، radiation ، low dose effects ، broiler ، Newcastle disease virus ، antibody

	Micro-pixe analysis in invasive ductal carcinoma tissues after treatment of astaxanthin S. Safaverdi، F. Roshani، M. Lamehi Rashti، Sh. Golkhoo، Z.M. Hassan ، L. Langroudi Page 33 (انگليسي) Abstract مشاهده متن [PDF 408KB]
	Background: Trace elements play an important role in a number of biological processes. Astaxanthin (ASX)، a carotoid pigment found in certain marine plant and animals، has shown anti cancer and anti free radical properties. This work intended to understand the effect of Astaxanthin in breast cancer (invasive ductal carcinoma، IDC) by using micro-pixe method. For this aim the concentration of trace elements were compared in healthy، cancerous and cancer treated with astaxanthin in the breast and liver tissues of breast cancer bearing mice، using proton induced X-ray emission (PIXE). Materials and Methods: Proton induced X-ray emission (PIXE) was used in a study intending to compare the concentration of trace elements in breast and liver tissues of mice bearing tumor، three groups of mice: healthy، cancerous، and cancerous treated by astaxanthin، were considered. Astaxanthin was supplied from Research Institute of women، Alzahra University. Results: Comparing the untreated tumor tissue، treatment with Astaxanthin significantly decreased the amount Fe، P، S، and Ca elements level in tumor tissue of the breast cancer. It is also found that the concentrations of those elements in liver of the untreated mice and the liver of treated mice with astaxanthin were fairly equal. Astaxanthin significantly decrease the accumulation of elements in the site of tumor، and caused the breast cancer cell membrane to lose their desire to collect the elements from healthy tissues. Conclusion: The micro -pixe technique could calculate elemental concentrations in tissues. Changes in metallic elements may affect microenvironment and cell functions، which might led lead to cell degeneration or death، the results shows that astaxanthin reduces vital element concentration in tumor site، thus it could be used as an anti tumor agent. Keywords: Breast cancerous tissues ، proton، induced X، ray emission ، astaxanthin ، trace elements

	Gonad، bone marrow and effective dose to the population of more than 90 towns and cities of Iran، arising from environmental gamma radiation M.T. Bahreyni Toossi ، Sh. Bayani، M. Yarahmadi، A. Aghamir، A. Jomehzadeh، M. Hagh Parast، A. Tamjidi Page 41 (انگليسي) Abstract مشاهده متن [PDF 419KB]
	Background: Since 1996 the assessment of environmental gamma radiation dose in residential areas of Iranian towns and cities has been accomplished for 10 counties. As a practical method and based on the results of a pilot study، in order to attribute the final results to the whole residential area of a town five stations were selected for every town. The location of individual station was studied closely to comply with recommended conditions in the literature. Materials and Methods: RDS-110 was employed to measure gamma dose rate for one hour. Average annual dose rates plus conversion coefficients were employed to estimate gonad، bone marrow، equivalent and effective dose. Result: Minimum and maximum annual bone marrow and gonad dose equivalent attributed to environmental gamma are 0.24 mSvy-1 (for both tissues) and 1.44 and 1.46 mSvy-1، respectively. Conclusion: Average gonad and bone marrow doses for North Khorasan، Boshehr and Hormozgan provinces were less than the corresponding values for normal area. Keywords: Gonad ، bone marrow ، effective dose ، environmental ، gamma radiation

	Verifying the accuracy of dose distribution in Gamma Knife unit in presence of inhomogeneities using PAGAT polymer gel dosimeter and MC simulation T. Allahverdi Pourfallah ، M. Allahverdi، N. Riyahi Alam، M.R. Ay، M.H. Zahmatkesh Page 49 (انگليسي) Abstract مشاهده متن [PDF 415KB]
	Background: Polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. MRI Polymer gel dosimeters are tissue equivalent and can act as a phantom material. In this study the obtained isodose maps with PAGAT polymer gel dosimeter were compared to those calculated with EGSnrs for singleshot irradiations of 8 and 18 mm collimators of Gamma Knife (GK) unit in homogeneous and inhomogeneous phantoms. Materials and Methods: A custom-built، 16 cm diameter spherical Plexiglas head phantom was. Inside the phantom، there was one cubic cutout for insertion of gel phantoms، and another cutout for inserting the inhomogeneities. The phantoms were scanned with a Siemens clinical 1.5 T MRI scanner. The multiple spin-echo sequence with 32 echoes was used for the MRI scans. Results: The results of measurement and simulation in homogeneous and inhomogeneous phantoms showed that the presence of inhomogeneities in head phantom could cause spatial uncertainty higher than ±2 mm and dose uncertainty higher than 7%. Conclusion: the presence of inhomogeneities could cause dose differences which were not in accordance with accuracy in treatment with GK radiosurgery. Moreover، the findings of Monte Carlo calculation revealed that the applied simulation code (EGSnrc) was a proper tool for evaluation of 3D dose distribution in GK unit. Keywords: Gamma knife ، PAGAT gel dosimeter ، EGSnrc ، dose distribution

	Does whole body exposure to GSM-950 MHz electromagnetic fields affect acquisition and consolidation of spatial information in rats? M. Jadidi، S.M. Firoozabadi، A. Rashidy، Pour ، B. Bolouri، Y. Fathollahi، A.A. Sajadi Page 57 (انگليسي) Abstract مشاهده متن [PDF 390KB]
	Background: This study was planned to examine the effects of whole-body exposure to GSM-950 MHz electromagnetic fields (EMFs) on acquisition and consolidation of spatial memory in rats using a water maze task. Materials and Methods: In experiment 1، the animals were given two blocks of five trials per day for three consecutive days in a water maze task. The interval between blocks was 4h. Before each training session، the animals were exposed to 950 MHz EMFs for 45 min with lower- (0.835 mW/cm2) or higher-power (1.166 mW/cm2) densities. In experiment 2، the animals were given two blocks of 5 trials with a 3 min interval between blocks. Immediately after the last trial، they were exposed to EMFs for 45 min with lower- or higher-power densities. In both experiments، 48 h after the last training day a 60 s probe test was done. Results: Results from experiment1 (pre-training exposure to EMFs) indicated no significant differences in performances of exposed and non-exposed groups either during acquisition (learning) or during probe test (memory retention). Results from experiment 2 (posttraining exposure to EMFs) also indicated no significant differences among groups during acquisition or probe test. Conclusion: In these experiments، no effect of exposure to 950 MHz on acquisition or consolidation of spatial navigation of rats in a water maze was detected. Keywords: EMFs ، 950 MHz wave ، whole body exposure ، spatial memory ، morris water maze

تاريخ انتشار: 11/2/88
تلفن: 88631199 (021)

تاريخ درج در سايت: 14/11/88
شمار بازديدکنندگان اين شماره: 117

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