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Showing 12 results for Mahmoud
S.a. Haeri, H. Mozdarani, M. Foroghizadeh, A. Mahmoudzadeh,
Volume 2, Issue 2 (9-2004)
Abstract
Background: Lymphocyte-dicentric assay is the most generally accepted method for biological dosimetry of overexposed individuals. In this study, the frequency of unstable chromosome
aberration in blood lymphocytes was used to estimate radiation dose received by individuals. Evaluation of dose using a calibration curve produced elsewhere may have a significant uncertainty therefore, experiments were performed to produce a dose-response curve using an
established protocol of international atomic energy agency. Materials and Methods: Lymphocytes in whole peripheral blood obtained from healthy
individuals, were exposed to various doses of gamma radiation (0.25 – 4 Gy). Then after 1 hour of incubation in 37 oC, were cultured in complete RPMI-1640 medium. 500 mitoses were
analysed for the presence or absence of unstable chromosomal aberrations for each radiation dose after the standard metaphase preparation and staining slides. Results and Conclusion: Intercellular distribution of dicentric chromosomes at each radiation dose has been used to contrast a dose-response curve. It seems that dose-effect relationship
follows with the linear-quadratic model. There is a good agreement between our dose-response curves with similar published studies by other laboratories. Iran . J. Radiat. Res., 2004 2 (2): 85-8 8
Mr. A. Mahmoudzadeh Emamchai, H. Mozdarani, S. Mohammadifrad,
Volume 6, Issue 4 (3-2009)
Abstract
Premature Chromosome Condensation (PCC) appears to have a possible utility for biological dosimetry purposes. The PCC technique may be adapted for cases of suspicion of overexposure where sampling is performed at least one day after an accident. For this purpose, human blood samples were exposed in vitro to 60Co up to 10 Gy and the PCC technique was performed immediately after irradiation. Analysis of excess PCC fragments distribution showed an over dispersion and the dose- effect relationship was best characterized by linear regression. Iran. J. Radiat. Res., 2009 6 (4): 213-218
R. Mahmoudi, Dr. S.m.j. Mortazavi, S. Safari, M. Nikseresht, H. Mozdarani, M. Jafari, A. Zamani, M. Haghani, M. Davari, A. Tabatabaie,
Volume 13, Issue 4 (10-2015)
Abstract
Background: Wi-Fi allows electronic devices such as laptops to exchange data or connect to a network resource. The main goal of this study was to assess the bioeffects of short term exposure to 2.4 GHz microwave radiation emitted from a common Wi-Fi router on sperm quality. Materials and Methods: Male Wistar rats were divided into 7 groups; I, sham exposed 4 h/day for 7days at 30 cm from the router. II, exposed for 2 h/day for 7days at 30 cm and sacrificed after 53 days. The exposure protocols for groups III to VII were 2h – 30 cm, 2h – 60 cm, 4 h – 30 cm, 4 h- 60 cm, 4 h – 30 cm (no data exchange) respectively. Rats in all the groups except group II, were sacrificed immediately after exposure and basic parameters of testicles weight, sperm motility, morphology, count, and DNA fragmentation were studied. Non-parametric tests were used to detect statistically significant differences between different groups. Results: Findings of this study showed statistically significant differences between the relative frequency of progressive and rapid progressive sperms in sham exposed rats compared to those of exposure groups. The testicles weight, DNA fragmentation of sperms and the frequency of sperms with normal morphology were not affected by Wi-Fi radiation. However, statistically significant differences between sperm count of the sham exposed rats compared to those of exposure group were observed. Conclusion: Exposure to microwave radiation emitted from Wi-Fi routers affects sperm parameters such as count and motility which are among the key parameters determining the chance of conceiving.
Dr. N.n.a Razak, A.a. Rahman, S. Kandaiya, I.s. Mustafa, A.a. Mahmoud, N.z. Yahaya,
Volume 14, Issue 4 (10-2016)
Abstract
Background: An effective polymer gel dosimeter can be fabricated by varying the composition of its chemical components. Materials and Methods: The MAGAT gel dosimeter formulations that used different compositions of Methacrylic acid (MAA) and gelatin were extensively investigated in the present study according to the R2–dose response and R2–dose sensitivity. The irradiation of MAGAT gel was performed by 6-MV photon beam at a dose range 1 to 10 Gy and was imaged by 1.5T Magnetic Resonance Imaging (MRI). The dose response of MAGAT gel dosimeter was obtained from spin-spin relaxation rate (R2) of MRI signal. Results: The MAGAT gel dosimeter composed of 5% gelatin and 6% MAA gave the highest sensitivity (1.1180 s-1Gy-1). Conclusion: Understanding the effects of the compositional changes will help to clarify the mechanisms involved in the dose response of the MAGAT gel dosimeter.
S. Azimi, Prof H. Mozdarani, A. Mahmoudzadeh,
Volume 15, Issue 2 (4-2017)
Abstract
Background: Medical diagnostic procedures such as X-ray and computed Tomography (CT) scan account for considerable percent of patient's exposure to ionizing radiation. The exposure of cells to Ionization radiation results in induction of DNA damage and chromosomal aberrations. Contrast media (CM) are widely used in diagnostic radiology and CT scan. The aim of this study was to study adverse genetic effects of combined administration of non ionic contrast media and low dose X-rays in peripheral blood Lymphocytes of patients following abdominal CT scan. Materials and Methods: A total of 55 patients underwent abdominal CT scan with injection of non ionic contrast media (30 patients with omnipaque 300 mg/ml and 25 patients with visipaque 270 mg/ml) as well as 13 patients undergoing abdominal CT scan (without contrast), selected as control group, were enrolled in this study. Peripheral blood leukocytes were obtained in heparin containing tubes and cultured for the micronucleus test, or were directly used for apoptosis and DNA damage with the neutral comet assay. Results: The frequency of micronuclei, apoptosis and percentage of DNA damage was increased in most patients after the injection of contrast media, significantly different from the control group as compared with the samples obtained before and after injection of contrast media (P<0.05). Conclusion: The present study suggest that non ionic contrast media (omnipaque 300 mg/ml and visipaque 270 mg/ml) may cause a significant increase of cytogenetic damage in peripheral blood lymphocytes. This effect might be caused by the enhancement of radiation dose by CM that eventually may lead to the manifestation of ill health such as cancer.
H. Zarei, Professor H. Mozdarani, A. Mahmoudzadeh, M. Salimi, H. Eyni, M. Bakhshandeh,
Volume 16, Issue 1 (1-2018)
Abstract
Background: Due to abscopal effect, cell damage may occur outside of the radiation field and the quantification of this effect is one of the most challenging debates in radiation therapy. The aim of this study was to estimate the abscopal effect induced in non-irradiated tumors quantitatively by means of biological effective dose (BED). Materials and Methods: Breast tumors using 4T1 and MC4-L2 cells, were induced into the flank region of Balb/c mice. When palpable, the tumor on one side of the body was irradiated with dose of 28Gy in 14 fractions and 2 Gy per fraction, 5 fractions per week. The tumor on the other side of the body was shielded with a lead plate. BED was estimated based on tumor volume. H&E staining and TUNEL assay were performed to assess histological changes and apoptosis in irradiated and non-irradiated tumors. Results: The effect of radiation on non-irradiated tumors was more than that on irradiated ones. The BED was 4.49 and 6.74 in 4T1 and MC4-L2 tumors, respectively. The ratio of the tumor volume in the last fraction to that in the first fraction for irradiated 4T1 tumors was 2.32 and in non-irradiated was 1.50. This ratio in irradiated and non- irradiated MC4-L2 tumors was 2.64 and 1.98, respectively. The number of apoptotic cells was higher in non-irradiated tissues. Conclusion: Results indicate that the occurrence of abscopal effect is highly depends on the type of tumor. By means of the abscopal effect, more radiation dose can be delivered to the tumor and metastatic sites.
H. Saghaei, Prof. H. Mozdarani, A. Mahmoudzadeh,
Volume 17, Issue 2 (4-2019)
Abstract
Background: DNA damage in male germ cells due to exposure to environmental and manmade physico-chemical genotoxic agents is considered as the main cause of male infertility. The aim of this study was to evaluate the effects of combined modalities (radiotherapy and chemotherapy) routinely used for cancer treatment on mouse sperm chromatin in vivo. Materials and Methods: Forty-eight mice were divided into 12 groups: 3 irradiation (1, 2, and 4 Gy), 2 drug [Actinomycin-D (ACTD) and Bleomycin (BLM)], 3 ACTD/irradiation, 3 BLM/irradiation, and a control. Mice received intratesticular injection of 7µg/25 g of Actinomycin-D and Bleomycin before irradiation with X-rays. Forty-eight hours after irradiation, mice were sacrificed and epididymis and testes were removed. Sperm DNA damage was assessed with the use of alkaline comet assay. Moreover, morphology, and motility of sperms were investigated microscopically. Results: Result showed that drug alone had slight but not significant effect on sperm DNA damage, but significantly increased when combined with irradiation. There was a significant difference between the experimental and the control group in DNA sperm damage, but no significant differences were observed in sperm morphology (p>0.05). In the drug+4Gy group, DNA damage increased dramatically compared to the controls (p<0.01), morphology changes increased to about six times that of controls. Conclusion: Results indicate that X-ray induced DNA damage and morphological changes in sperms in a dose dependent manner. Low doses of drugs led to potentiation of radiation effect. This might be indicative of necessity for radiation protection of testes when are in field of radiotherapy.
F. Pakniyat, S. Gholami, Ph.d., H.a. Nedaie, Ph.d., H. Mozdarani, A. Mahmoudzadeh, M. Salimi,
Volume 18, Issue 3 (7-2020)
Abstract
Background: The Linear Quadratic (LQ) equation as the most common formula in radiotherapy has a debatable accuracy in modeling high-dose effects. The purpose of this study was to demonstrate bystander response of the Grid treatment in SCC cell line, based on both theoretical calculations and experimental investigations. Materials and methods: The linear quadratic model was used to calculate the equivalent uniform dose (EUD) of a Grid-field with the 10 Gy maximum doses. According to the EUD definition, the identical tumor survival fraction (SF) was expected to obtain from both Grid and open-field single fraction. After observing the difference, the clonogenic and apoptosis assays were exerted to investigate bystander response via medium transfer strategy which was performed from 10Gy-irradiated donors to 1.5Gy-irradiated recipients. Results: The EUD was equal to 4 Gy and the SF of 4 Gy EUD and 10 Gy Grid-field were 0.1 ± 0.02 and 0.051 ± 0.008, respectively. These findings contradicted the theoretical expectations of their survivals equality. Moreover, the bystander clonogenic cells death enhanced approximately by 2.91 times (statistically significant); highlighting the bystander response role. The apoptotic findings illustrated that the bystander cells experienced an approximately 10% increase and the apoptotic rate confirmed the clonogenic survival result which was less in the EUD than the Grid-field. Conclusion: Since the SF of the Grid-field was less than the EUD, it revealed the Grid therapeutic advantages plus bystander response manifestation; that was ignored in the LQ equation and may not be demonstrated by sheer theoretical calculations of the modulated-field.
P. Mehnati, H. Sabri, R. Meynaghizadeh Zargar, Y. Rasoulzadeh, D. Mahmoudi, M.sc., R. Malekzadeh,
Volume 19, Issue 2 (4-2021)
Abstract
Background: The solar radiation consists of a vast spectrum of wavelengths such as visible light and ultraviolet radiation (UVR). The amount of UVR that reaches the Earth's surface is very important due to its role in vitamin D synthesis and causing skin cancers. The hourly and daily mean values of solar UV type A, B, and visible light radiation were measured for the first time during the year. Materials and Methods: The hourly and daily mean values of UVR and visible light intensity of solar radiation at Tabriz were measured and analyzed between the 2017 and 2018 years. The intensity of solar UVA and UVB radiation was measured by Hand-held Lux-UV meter device from sunrise to sunset for one hour. Results: The results showed that the highest values of UVA and UVB radiation, reaching the Earth were between 12 and 13 o’clock. The maximum and minimum values of UVR were recorded during the months of May and January, respectively. The maximum amounts of UVA and UVB during the whole year were 52.48 and 2.82 W/m2, respectively. Also, the lowest intensity of UVA and UVB radiation during the whole year was 22.19 and 0.79 W/m2, respectively. Conclusion: Comparison of maximum and minimum UV amounts of type A and B in May was about 2.36 and 3.56 times more than in January. The measurements showed that the intensity of UVA was significantly higher than UVB amounts.
E. Mahmoudi, M. Amoui, Ph.d., M.r. Deevband, E. Pirayesh, M. Ghorbani Rad,
Volume 20, Issue 1 (1-2022)
Abstract
Background: The present study was done to establish release criterion in the treated patients and to determine external radiation doses received by personnel and caregivers of patients with metastatic neuroendocrine tumors (NETs) during peptide receptor radionuclide therapy (PRRT) by means of Lutetium-177 (177Lu) DOTATATE. Materials and Methods: For this purpose, 30 patients were enrolled in the study who received 5.5±1.1 (in a range of: 3.7-7.4) GBq of 177Lu-DOTA-tyr3-octreotate. Dose rate was analyzed at distances 0, 0.25, 0.5, 1.0, and 2.0 m in different times after termination of infusion using an ionization chamber. Results: Mean dose rate at distance of 1 m from the patient, approximately 5 h after injection was considered as discharge limit. The maximum dose to caregivers in the first 48 h was equal to 340±29 μSv. Mean dose to the nurse was estimated as 6.3±0.4, and 7±0.5 µSv per patient with and without lead shield, respectively. Discussion: According to our findings, approximately a time delay of 5 h after injection is recommended as release criterion for patients treated by Lutetium-177 (177Lu) DOTATATE. For a total of 30 patients, external radiation dose to staff was found to be within permissible levels. Conclusion: The use of protective equipment is recommended at all stages of procedure for staff.
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