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1.
Iran J Med Sci ; 49(4): 237-246, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38680223

RESUMO

Background: Cell phone and Ultra-High Frequency (UHF) waves produce oxidative stress and cause testicular toxicity. This investigation was directed to evaluate the effectiveness of Rosmarinic Acid (RA) against oxidative stress caused by UHF radiation in rats. Methods: Forty-two male Wistar rats were divided into six groups. The control received 5 mL normal saline (0.9% NaCl) by gavage, the cell phone group received 915 MHz, the UHF waves group just received 2450 MHz, the RA/cell phone group received RA plus 915 MHz, RA/UHF waves group received RA plus 2450 MHz, and RA just received RA (20 mg/kg). After 30 days of consecutive radiation, the biochemical and histopathological parameters of their testes were measured. Statistical comparison was made using one-way ANOVA followed by Tukey's post hoc test. Results: Cell phone and UHF wave radiation significantly diminished the activity of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, and glutathione content (P<0.001). On the opposite, UHF significantly increased oxidative stress indices including malondialdehyde level, nitric oxide level, and protein carbonyl content (P<0.001). UHF also significantly reduced the number of Sertoli cells, spermatogonia, primary spermatocyte, epithelial height, and seminiferous tubular and luminal diameters (P<0.001). RA, as an effective antioxidant, reverses the above-mentioned harms and moderates the adverse effects of UHF on the testes of rats by significantly diminishing the oxidative stress indices and antioxidant enzyme rise and improving the histological parameters (P<0.001). Conclusion: RA can protect the testes of rats from UHF-induced toxicity by reducing oxidative stress. RA as a food supplement might be useful for protecting humans exposed to UHF environmental contamination.


Assuntos
Telefone Celular , Cinamatos , Depsídeos , Estresse Oxidativo , Ratos Wistar , Ácido Rosmarínico , Testículo , Animais , Masculino , Depsídeos/farmacologia , Cinamatos/farmacologia , Testículo/efeitos dos fármacos , Testículo/efeitos da radiação , Ratos , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/farmacologia
2.
Biomed Phys Eng Express ; 10(2)2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38316026

RESUMO

Dosimetric characteristics of the flattening filter (FF) and flattening filter free (FFF) modes of 18 MV therapeutic photon beam were investigated with and without the magnetic deflector (MD) and lead filter. MCNP version 6.1.0 Monte Carlo (MC) code was used to simulate the 18 MV photon beam of 2100 C/D-Varian linear accelerator (LINAC) for the FF and FFF modes. The MD (uniform magnetic flux density of 1 Tesla) and lead filter (thickness of 1 mm) were modeled to remove contaminant electrons. The dosimetric parameters for different scenarios of LINAC's head were calculated. Removing the flattening filter in the FFF mode increased the dose rate, electron contamination, skin dose, out-of-field dose, and un-flatness compared to the FF mode. While the lead filter decreased the contaminant electrons significantly, using the MD removed all secondary electrons from the beam line. The surface dose was decreased by 8.3% and 11.2% for the magnetic deflector (MD) and lead filter in the FF mode, respectively. The surface dose was decreased by 16.8% and 20.3% for the MD and lead filter scenarios in the FFF mode, respectively. The MD and lead filter decreased surface penumbra by 15.5% and 11.5% compared to the FFF mode. Removing the flattening filter from the LINAC's head improves most of the dosimetric characteristics of the 18MV therapeutic beam. The use of a lead filter and magnetic deflector preserves the skin-sparing property of megavoltage beams that deteriorate in FFF mode. However, using a magnetic deflector does not reduce photon fluence and dose rate.


Assuntos
Aceleradores de Partículas , Radiometria , Dosagem Radioterapêutica , Fenômenos Físicos , Fótons
3.
J Tehran Heart Cent ; 18(3): 207-213, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38146407

RESUMO

Background: Electromagnetic radiation (EMR) causes stable aggregation of reactive oxygen species (ROS), producing oxidative stress. Rosmarinic acid (RA), a plant-origin antioxidant, has been proposed against the side effects of cell phone and ultrahigh-frequency waves. Methods: Forty-two male Wistar rats were randomly divided into 6 groups. Group 1 (controls) received 5 mL of normal saline with the gavage method, Group 2 received 915 MHz radiation, Group 3 received 2450 MHz radiation, Group 4 received RA plus 915 MHz radiation, Group 5 received RA plus 2450MHz radiation, and Group 6 received oral RA (5 mg/kg). Treatment and radiation (1 hour per day) continued for up to 30 days. Results: EMR significantly reduced the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), the content of glutathione (GSH), and the level of total antioxidant capacity (TAC) and significantly increased oxidative stress indices, such as the levels of malondialdehyde (MDA) and nitric oxide (NO), and the content of protein carbonyl (PC). In contrast, RA significantly elevated TAC level (all groups), GSH content (the RA/cell phone radiation group), GPx activity (the RA/ultrahigh-frequency radiation group), SOD activity (all groups), and CAT activity (RA/ultrahigh-frequency radiation group) and conversely reduced MDA level (all groups), NO level (all groups), and PC content (all groups) in the RA/cell phone and RA/ultrahigh-frequency radiation groups compared with the NS/cell phone and NS/ultrahigh-frequency radiation groups, respectively. The administration of RA resulted in a significant reversal of cardiac markers in EMR-intoxicated rats. Conclusion: RA treatment showed a significant protective effect against EMR-induced cardiotoxicity.

4.
Appl Radiat Isot ; 174: 109776, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34082185

RESUMO

Therapeutic advantages of Grid therapy have been demonstrated in several theoretical studies using the standard linear-quadratic (LQ) model. However, the suitability of the LQ model when describing cell killing at highly modulated radiation fields has been questioned. In this study, we have applied an extended LQ model to recalculate therapeutic parameters of Grid therapy. This study shows that incorporating the bystander effects in the radiobiological models would significantly change the theoretical predictions and conclusion of Grid therapy, especially at high dose gradient fields.


Assuntos
Neoplasias da Mama/radioterapia , Modelos Lineares , Radiobiologia , Feminino , Humanos , Método de Monte Carlo , Radioterapia/métodos
5.
J Ultrasound Med ; 40(9): 1839-1850, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33179801

RESUMO

OBJECTIVE: Although epidemiological studies have failed to show the harmful effects of ultrasound in humans, as a form of energy, ultrasound has the potential to cause bio-effects in tissues. Therefore, clinical guidelines have been established for ultrasound technology related to human safety, which include Thermal (TI) and mechanical (MI) indices. The appropriate TI and MI ranges for embryonic examinations are between 0-1.0 and 0-0.4, respectively. The accepted TI and MI ranges are 0-2.0 and 0-1.9, respectively, for general ultrasound examinations. In addition, the scan duration should be kept as low as possible. Therefore, the present study aimed at evaluating the scan duration, TI, and MI as measures of acoustic output during ultrasound studies. METHODS: A cross-sectional descriptive study was conducted for patients undergoing pregnancy checkups, routine checkups, and initial diagnosis ultrasound examinations. Samples were selected from imaging departments of 4 educational hospitals based on convenience sampling and 321 checklists completed by direct observation of ultrasound examinations. RESULTS: For pregnancy scans, the mean TI and MI were obtained as 0.32 ± 0.27 and 1.15 ± 0.13, respectively. For non-pregnancy examinations, the mean value of TI and MI were 0.30 ± 0.29 and 1.07 ± 0.35, respectively. Therefore, mean TI for pregnancy and non-pregnancy examinations and mean MI for non-pregnancy studies obtained lower than the permitted values, while the mean MI was higher than the permitted level for first trimester of pregnancy. Also, relatively suitable scan durations were seen in reviewed studies. CONCLUSION: From this study, it may be concluded that the reported ultrasound scans were safe.


Assuntos
Ultrassonografia Pré-Natal , Estudos Transversais , Feminino , Humanos , Gravidez , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Ultrassonografia
6.
Arch Iran Med ; 23(2): 104-112, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061073

RESUMO

BACKGROUND: Considering the non-invasive nature of magnetic resonance spectroscopy (MRS) and its ability to detect prostate lesions, the present study aimed to investigate the accuracy of MRS techniques in distinguishing between prostate cancer (PCa) and prostatitis. METHODS: Thirty-three patients (18 patients with PCa and 15 patients with prostatitis) were recruited for this study. Magnetic resonance imaging (MRI) and MRS were performed using 1.5-T system GE- modle Optima 450 Discovery (GE Medical Systems, US). The (Cho+Cr)/Cit ratio of hypointense T2 areas were calculated. The diagnostic accuracy including sensitivity and specificity indices, with 0.95 confidence interval as well as PPV and NPV were calculated for each variable. The receiver operating characteristic (ROC) area under the curve (AUC) was outlined and investigated. The mean quantitative values between the two groups (PCa and Prostatitis) were compared using independent t test. RESULTS: The mean ratios of Cho+Cr/Cit in PCa was 1.54 ± 0.63 and 0.83 ± 0.48 for PCa and prostatitis, respectively, indicating a significant statistical difference (P = 0.00). A reduction in citrate was seen in both PCa and prostatitis tissue. Significant elevation in choline peak was shown for PCa. Moreover, creatinine level was low in both normal tissue and PCa without significant difference. Sensitivity, specificity, accuracy, PPV and NPV of MRS were 94.4% (95% CI, 74.2-99), 80% (95% CI, 54.8-93), 96%, 85% and 92.4%, respectively. CONCLUSION: The results of this study indicate an acceptable level of sensitivity, specificity and accuracy of MRS in the differential diagnosis of PCa and prostatitis.


Assuntos
Espectroscopia de Ressonância Magnética/normas , Neoplasias da Próstata/diagnóstico por imagem , Prostatite/diagnóstico por imagem , Idoso , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC
7.
Asian Pac J Cancer Prev ; 19(11): 3053-3057, 2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30485940

RESUMO

Background and objectives: To determine the head scatter factor, a formalism presented by Vadash and Bjärngard has been employed to assess collimator exchange effects. The aim of this study was to determine the best Vadash correction factor (A) by introducing a new method based on the output factor measured in air for different square and rectangular fields. Materials and Methods: A new simple mathematical method based on selection of the best dosimetric data was proposed to obtain the A value for Vadash to predict the equivalent square field size. Measurements were performed with a Farmer chamber 0.6 cc in SSD 100 cm and build up cap of Plexiglas, 1.5 and 3.5 cm equal to water, for 6 and 18 MV, respectively, with a Perimus Plus linear accelerator. The output factor in air (OFair) was measured for square and rectangular fields. MATLAB software (version R2014a) was employed for calculations and curve fitting. Results: A power model with a constant value was applied to the output factor in air as a function of square field size. The output factor in air ranged from 0.983 to 1.038 at 6MV and from 0.731 to 1.05 at 18 MV with the Y collimator having a greater effect. Obtained values for A were 1.42 and 1.55 with respect to σmin=0.98 and 2.3 for 6 and 18 MV energies, respectively. Conclusion: The proposed A values minimize the collimator exchange effect in calculating equivalent squares, which plays an important role in patient dose calculation and treatment planning.


Assuntos
Algoritmos , Neoplasias/radioterapia , Aceleradores de Partículas/instrumentação , Imagens de Fantasmas , Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Dosagem Radioterapêutica , Software
8.
Data Brief ; 20: 1269-1273, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30238038

RESUMO

The purpose of the data is to estimate the excessive risk of cancer due to some common radiographs in Tehran. The data were collected in 8 radiology centers in Tehran city and on 283 patients with eight radiographic views. To obtain the data, PCXMC 2.0 based on Monte Carlo calculations, has been used to calculate the effective dose of each organ, and annual effective dose. The effective dose, cumulative effective dose, number of radiographs per year and excessive cancer risk due to the type of radiographs calculated. The additional risk of lethal cancer resulting from these radiographs in the target population is about 14.81 cases of the total population of Tehran city in one year.

9.
Arch Iran Med ; 21(12): 585-588, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30634856

RESUMO

BACKGROUND: Extracorporeal shock wave lithotripsy (ESWL) is considered as the method of choice for treatment of most stone diseases. The present study aims to evaluate radiation dose received by patients undergoing ESWL. METHODS: In total, 46 patients from both genders were referred to the Shohadaye Ashayer hospital of Khorramabad, Iran and were included in the present study. Patients were positioned in anteroposterior (AP) projection and along 30° anterior oblique (AO) projection upon the X-ray fluoroscopy table and exposures were conducted. Thermoluminescent dosimeters (TLDs) were used for radiation dose measurements. To evaluate the entrance surface dose (ESD), each TLD chip was taped on back of patient at the entrance surfaces of the X-ray beam. RESULTS: The mean number of stones in each patient was 1.4. The stone sizes ranged from 7 to 29 mm, and a mean of 3200 pulses were need for each patient. The mean ESD in the postero-anterior (PA) and oblique X-ray beam entrance were obtained at 12.04 and 68.84 mGy, respectively. There was linear correlation between patient dose with fluoroscopy time, tube current (mA), tube potential (kVp) and patient position (P < 0.001); however, we found no strong correlation between patient dose with patient body mass (P = 0.837), number of shock wave pulses (P = 0.089), stone size (P = 0.773) and locations (P = 0.463). CONCLUSION: The data obtained in the current study are comparable with information available in the literature. They emphasized that ESWL exposes patients to much more radiation compared to those from conventional radiography and is in the range of computed tomography (CT) procedures. Therefore, following safety guidelines is recommended.


Assuntos
Litotripsia/métodos , Posicionamento do Paciente , Doses de Radiação , Cálculos Ureterais/terapia , Adulto , Idoso , Feminino , Fluoroscopia , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Monitoramento de Radiação/métodos , Medição de Risco , Fatores de Risco
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