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Showing 7 results for Lei
S. Taeb, Dr. S.m.j. Mortazavi, A. Ghaderi, H. Mozdarani, Ce. de Almeida, M.r. Kardan, S.a.r. Mortazavi, A. Soleimani, I. Nikokar, M. Haghani,
Volume 12, Issue 2 (4-2014)
Abstract
Background: Ramsar (Mazandran province) is known for its extremely high levels of natural background radiation. Although no excess cancer rate is reported in these areas by epidemiological studies, the study of tumor markers in the inhabitants of these areas may shed some light on the impact of high levels of background radiation on cancer induction. Materials and Methods: The level of background gamma radiation as well as indoor radon was determined using RDS-110 and CR-39 dosimeters. Thirty five individuals from a high background radiation area (HBRA) and 53 individuals from a normal background radiation area (NBRA) were randomly selected to participate in the study. Commercial ELISA kits (sandwich type ELISA tests) were used to measure the serum levels of PSA, CA15.3, CA125, Cyfra21-1, CEA, CA19.9, AFP and Tag72 tumor markers. Results: Among the eight biomarkers investigated, the means of PSA, CA15.3, CA125, CA19.9 and AFP concentrations between the HBRAs and NBRAs were not significantly different. However, Cyfra21, CEA and Tag72 in HBRA group revealed statistically significant increases compared to those of NBRA group (P<0.05). Furthermore, a statistically significant correlation between the external gamma dose as well as indoor radon level and the concentration of CEA (P<0.001), Cyfra-21(P<0.001) and TAG 72 (P<0.001 and 0.01 respectively) biomarkers were observed. Conclusion: Chronic exposure to high background radiation induces significant alterations in Cyfra21, CEA and Tag72 levels. We believe that studies with other relevant tumor markers might overcome the limitations of epidemiological studies on cancer incidence in high background radiation areas.
M. E. Parsanezhad, Dr. S. M. J. Mortazavi, T. Doohandeh, B. Namavar Jahromi, H. Mozdarani, A. Zarei, M. Davari, S. Amjadi, A. Soleimani, M. Haghani,
Volume 15, Issue 1 (1-2017)
Abstract
Background: The health effect of rapidly increasing everyday exposure of humans to radiofrequency radiation is a major global concern. Mobile phone jammers prevent the mobile phones from receiving signals from base stations by interfering with authorized mobile carriers’ services. In spite of the fact that mobile jammer use is illegal, they are occasionally used in offices, shrines, conference rooms and cinemas. The purpose of this study was to investigate the biological effects of short term exposure of human sperm to radiofrequency radiation emitted from a commercial mobile phone jammer. Materials and Methods: Fresh semen samples were obtained by masturbation from 50 healthy donors who had referred with their wives to Infertility Treatment Center at the Mother and Child Hospital, Shiraz University of Medical Sciences. Female problem was diagnosed as the reason for infertility in these couples. The semen sample of each participant was divided into 4 aliquots. The first aliquot was subjected to swim-up and exposed to jammer radiation. The second aliquot was not subjected to swim-up but was exposed to jammer radiation. The third and fourth aliquots were not exposed to jammer radiation but only the 3rd aliquot was subjected to swim-up. Results: Semen samples exposed to radiofrequency radiation showed a significant decrease in sperm motility and increase in DNA fragmentation. Conclusion: Electromagnetic radiation in radiofrequency range emitted from mobile phone jammers may lead to decreased motility and increased DNA fragmentation in human semen. It can be concluded that mobile phone jamming might exert adverse reproductive health effects.
M. Azimzadeh, Dr. G.a. Jelodar, F. Namazi, F. Soleimani,
Volume 16, Issue 4 (10-2018)
Abstract
Background: Exposure to electromagnetic radiation may impair memory. This study was conducted to evaluate the effect of radiofrequency wave (hereafter referred to as RFW) on passive avoidance learning and memory in healthy males and females. Materials and Methods: Ten adult male and ten female Sprague-Dawley rats (230±20 gr) were randomly divided into four groups including two control groups (one for males and one for females), and two experimental groups (exposed to 900 MHz radio frequency wave) each representing one gender. The exposure was performed for 30 consecutive days (4h/day). Evaluation of learning and memory of the rats started on the last day of exposure by shuttle box. Learning and memory of animals was recorded by the period of time they remained within the light area; this time was called the light time. Results: Results of the study showed that exposure to RFW significantly decreased the duration of light time in the rats within the experimental groups as compared to the control groups (P<0.05). Exposure to RFW significantly decreased the light time in females in comparison to males in the experimental group (P<0.05). Histological study of brain section did not show significant changes between groups. Conclusion: With regard to these findings, it was concluded that exposure to RFW causes disorder in memory retention of passive avoidance learning in rats. The extent of damage to the learning and memory in rats exposed to RFW was more for females than males.
P. Yang, Z. Chen, Q. Lei, C. Yin, S. Zhang, Z. Wu, Dr. C. Gou,
Volume 19, Issue 2 (4-2021)
Abstract
Background: Current dose algorithms, such as the collapsed cone convolution algorithm and anisotropic analytical algorithm, are widely used in commercial treatment planning systems. Nevertheless, it is difficult to calculate the dose distribution of heterogeneities for small fields by using these algorithms, because of the electronic disequilibrium. However, contemporary treatment uses small beamlets more and more frequently, such as stereotactic body radiation therapy and intensity-modulated radiation therapy. In this study, a new inhomogeneity method in lung medium for small fields was presented. Materials and Methods: Inhomogeneous lung phantoms for different small fields were established, and different locations and thicknesses of lung media in inhomogeneous phantoms were also considered. The Monte Carlo code EGSnrc was used to calculate the density factor and the percentage depth-dose (PDD) distribution of lung phantoms. The PDDs were also calculated with the new algorithm, and then differences in the PDDs were determined. Results: The comparison shows that there is a good agreement between the new algorithm and the Monte Carlo code in different energy. The discrepancies of the three field sizes were less than 3%. With an increase in field size, the discrepancies were less than 1%. Even with changes in the location and thickness of the lung media in inhomogeneous phantoms, the discrepancies were always less than 1%. Conclusion: The comparative results revealed the effectiveness of the new algorithm in calculating depth-dose distribution, under different conditions, and that it can meet the requirements for calculating percentage depth dose distribution.
M. Nabipour, Ph.d., M.r. Deevband, A. Asgharzadeh Alvar, N. Soleimani,
Volume 20, Issue 3 (7-2022)
Abstract
Background: In regard to the enhanced use of mammography screening tests for screening breast cancer, some concerns on the enhancement of the patient's absorbed dose have increased as well. Therefore, the assessment of the patient's dose before mammography is very important, and being aware of the dose level by its estimation can be helpful before radiation. Materials and Methods: To this end, an artificial neural network (ANN) was used in this study to estimate the entrance surface air kerma (ESAK). A phantom with similar characteristics of the breast tissue was also used to collect the required data and the network was trained using some measurable parameters. To conduct the current research, multilayer perceptron (MLP) neural network architecture with training algorithms of LMBP, SCGBP, Rprop, BFGS, and GDBP, as well as radial basis function (RBF) neural network were used. Results: The results show that the neural network with BFGS training algorithm and 38 hidden layer neurons has the best performance with 7.40% root mean square error (RMSE) and coefficient of determination (R2) was obtained as 0.91. Conclusion: According to the results of this study, there is a good correlation between the estimated network output and the measured values of the ESAK. The present method will remove the limitations and costs associated with the preparation process of dosimeter instruments.
J. Zeng, J. Wang, Q. Guo, Y. Hou, Q. Lei, B. Yao, J. Lan, D. Zheng, Q. Feng, Z. Li, F. Chen, J. Xing, Y. Fang,
Volume 20, Issue 4 (10-2022)
Abstract
Background: Although radioiodine-131 (131I) has been widely used for the treatment of Graves' disease (GD), radiation is a potential risk factor for mutagenic abnormalities. This retrospective clinical study mainly aimed to investigate the influence of maternal exposure to 131I used for the treatment of GD prior to pregnancy on chromosomal aberration and intellectual development of offspring in China. Materials and Methods: In total, 69 children whose mothers received 131I for the treatment of GD during childbearing age were included. Data on the obstetric history, medical records, and the birth characteristics of the children were obtained. The thyroid function, thyroid ultrasound, chromosomal structure, and somatic and intellectual development of the children were measured. Results: In all 66 women, the range of the administered 131I was within 228.2 ± 70.3 MBq. The height and weight of all children were within the normal ranges, and one child was confirmed as having subclinical hypothyroidism. Two children were diagnosed with benign thyroid nodules, one child was diagnosed with thyroid cysts, and one child was confirmed as having several anechoic areas in both lobes of the thyroid gland. Chromosomal aberration was observed in one child. None of the children showed any abnormalities in somatic and/or intellectual development. Conclusion: This is the first study to confirm that 131I used for the treatment of GD prior to pregnancy does not significantly increase the risk of chromosomal aberration or impair the intellectual development of offspring.
Ph.d., Y. Chen, S. Chen, Y. Li, X. Guo, Q. Liang, L. Yang, C. Lei,
Volume 22, Issue 2 (4-2024)
Abstract
Background: The To measure regulatory T cells (Tregs) expression in driver-gene-negative advanced non-small cell lung cancer (NSCLC) as well as its effect on the therapeutic efficacy and prognosis of immune checkpoint inhibitors (ICIs). Materials and Methods: Fifty patients with advanced non-small cell lung cancer without driving genes who were receiving treatment with a monoclonal antibody targeting the programmed death receptor-1 (PD-1) made up the study group. 30 healthy subjects in the same period were chosen into the control group. Flow cytometry was used to identify CD4highCD25+Foxp3+Treg cells in peripheral blood of all participants. Relation between CD4highCD25+Foxp3+Treg cells and tumor markers were explored, and efficacy and prognosis in patients before and after therapy was analyzed. Results: The fraction of CD4highCD25+Foxp3+Treg cells in the study group was higher (P<0.05). Following three rounds of PD-1 monoclonal antibody treatment, patients' CD4highCD25+Foxp3+Treg cells proportion was lower than before treatment (P<0.01), and showed a positive correlation with tumor markers (P<0.05). The fraction of CD4highCD25+Foxp3+Treg cells in the CR+PR group decreased in both the second and third cycles after treatment compared to the SD+PD group (P<0.01), but no change was found before or during the first cycle (P>0.05). CD4highCD25+Foxp3+Treg cells proportion in the death group presented higher relative to the survival group (P<0.05). CD4highCD25+Foxp3+Treg cells predicted the area under the ROC curve was 0.8134, with significant difference (P<0.05). Conclusion: CD4highCD25+Foxp3+Treg cells proportion in peripheral blood of NSCLC patients shows increased, and has predictive value for therapeutic efficacy of ICIs and prognosis of driver-gene-negative advanced NSCLC patients.
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