Journal of Isfahan Medical School
Year:2019 | Volume:37 | Issue:519|Papers Count:6

Background: Todays, radiotherapy with high-energy photons is used as a common modality for cancer treatment. Unfortunately, high-energy photons can produce unwanted neutrons, and subsequently lead to increase the risk of secondary cancer in unshielded healthy organs. Methods: Using Monte Carlo (MC) code (MCNPX® ), the main parts of a typical Medical Linear Accelerator (LINAC) was modeled in 18 MV. Then, neutron source strength (Q) of the LINAC and neutron mean energy were evaluated for different treatment fields, and also different points at the treatment table. Additionally, to estimate the probability of secondary cancer risk, the neutron equivalent dose was calculated at some of the human’ s critical organs. For this purpose, the female medical internal radiation dosimetry (MIRD) phantom was included in the MC simulations. Findings: The Q was found as 1. 25-1. 38 (all in 1012 n/Gy) for different treatment fields meaning significant portion of neutrons with a mean energy of 0. 59-0. 90 MeV around the LINAC. Additionally, the total secondary cancer risk in unshielded healthy organs was calculated as 0. 0924% which maximum and minimum were related to stomach (0. 0216%) and thyroid (0. 0005%), respectively. Conclusion: Regarding the estimated values for the probability of secondary cancer risk, it is suggested that in conventional radiotherapy of deeply seated tumors, the 15-MV photons are preferred instead of using 18-MV photons due to their less biological side effects.

Background: Type 2 diabetes mellitus (T2DM) is the most common form of diabetes caused by insufficient insulin secretion, insulin resistance, or both. Considering the high prevalence of T2DM, and the role of various components in the progress of the disease, and in order to better understand some of the mechanisms of pathogenesis responsible for the progression of T2DM, this study aimed to investigate if the levels of cholesterol synthesis and absorption markers in patients with T2DM was different compared with healthy subjects. Methods: In this cross-sectional study, 150 men between 40 and 60 years of age were selected from people attending Isfahan diabetes centers and the Isfahan Endocrine and Metabolism Research Center, Isfahan, Iran. The subjects were divided into control group including 50 apparently healthy men with normal fasting blood glucose (FBG) and no history of T2DM, and 100 patients with FBG ≥ 126 mg/dl and a history of T2DM. Fasting serum and plasma samples were used to measure biochemical parameters using commercial laboratory methods, and absorption and synthesis markers of cholesterol, using gas chromatography-mass spectrometry technique. Statistical analyzes were done via SPSS software using Kolmogorov-Smirnov, independent t, and Mann-Whitney tests at the significance level of P < 0. 05. Findings: There were significant differences in the biochemical and anthropometric parameters between the studied groups. Evaluation of the concentration ratio of absorption (β-sitosterol and campesterol) and synthesis (lathosterol and desmosterol) markers to cholesterol showed a significant increase in the synthesis markers, and a significant decrease in the absorption markers in the patients group compared to the control group (P < 0. 05). Conclusion: The results of this study indicate that the rate of cholesterol synthesis is increased, and that of cholesterol absorption is decreased in a population of Iranian patients with T2DM. These findings are in accordance with data from other populations, and may indicate that the cholesterol synthesis and absorption markers may be used as surrogate markers to better understand some of the pathogenesis mechanisms involved in the development and complications of T2DM, and may help to predict, and treat its complications more effectively in the future.

Background: Sleep is an effective factor in physical and psychological health that its lack can cause a malfunction in the daily functioning, as well as loss of overall performance. Methods: This cross-sectional study was conducted on 918 students of Isfahan University of Medical Sciences, Isfahan University of Technology, and the University of Isfahan in Isfahan City, Iran. Clustered random sampling method was used to select the participants. The instruments used were the demographic questionnaire and sleep health scale. Data were analyzed using covariance analysis and Tukey’ s post hoc test. Findings: The mean total score of the sleep hygiene questionnaire was 297. 90 ± 39. 15, which varied from 195 to 425. The mean score of the total score of the questionnaire was higher in students of Isfahan University of Medical Sciences compared to other universities (P < 0. 050). Girls of Isfahan University of Medical Sciences scored the highest score (P < 0. 050). The average score of knowledge of sleep health was significantly higher in students of Isfahan University of Medical Sciences than in Isfahan University of Technology (P < 0. 001) and in University of Isfahan (P < 0. 001). The mean score of sleep hygiene knowledge had a significant and direct relation with different years of study and age (P < 0. 050). The average score of sleep attitude was higher in dentistry students than other students (P < 0. 001). Conclusion: Results showed that medical students have a better attitude and function of sleep health. Mean scores of attitude, performance, and sleep hygiene were significantly higher in students of Isfahan University of Medical Sciences than in other two universities, and the mean score of girls in Isfahan University of Medical Sciences was higher than other groups.

Background: Pulmonary embolism (PE) is a blockage in one of the pulmonary arteries. Ventilation/Perfusion (V/Q) scan is one the diagnostic methods of PE in pregnant women. It is necessary to investigate fetal dose and compare it with recommended values. The aim of this study was to determine the fetal dose in V/Q scan using Monte Carlo simulation. Methods: An adult pregnant woman phantom and all her displaced organs were used for simulation. Source organs were defined for each of the radiopharmaceuticals used in two lung ventilation and perfusion scans, including lung and bladder for 133Xe, 81mKr, and technetium diethylene-triamine-pentaacetate aerosol (99mTc-DTPA-aerosol) for lung ventilation scan, and lung, bladder, and liver for 99mTc-technetium macroaggregated albumin (MAA) for lung perfusion scan. Fetal dose was determined and evaluated using the simulation output after calculations. Findings: For 99mTc-MAA at prescription dose of 200 MBq, fetal dose was found to be 1. 01 mGy, maximum fetal dose was 1. 97 mGy, and both of them were more than the values recommended by International Commission on Radiological Protection (ICRP). For 99mTc-DTPA, fetal and maximum doses were below 1 mGy, and for 133Xe and 81mKr, fetal dose was negligible. Conclusion: It is concluded that considering higher dose to the fetus (200 MBq of 99mTc-MAA), if the pregnant woman scan is needed, her awareness must be done.

Background: Rosemarinic acid is a phenolic compound that has neuroprotective properties. It has beneficial effect in neurological diseases such as Parkinson's and Alzheimer's. Rosmarinic acid increases the expression of neurotrophic factors such as brain-derived neurotrophic factor (BDNF), which can contribute in neuronal differentiation of stem cells. Methods: After isolation and proliferation, Wharton’ s jelly stem cells were placed in inductive culture medium containing Rosmarinic acid. MTT assay was used to evaluate toxicity. After 4 days, induction of neuronal differentiation in Wharton’ s jelly stem cells was evaluated using real-time polymerase chain reaction (real-time PCR) via analyzing the expression of Nestin and β-Tubulin III genes. Findings: MTT assay showed was no significant difference in viability between cells cultured in culture medium with Rosmarinic acid and control group (P < 0. 05). Real-time PCR showed that adding Rosmarinic acid to culture medium increased the expression of Nestin and β-Tubulin III genes (P < 0. 05). Conclusion: Increasing the expression of β-Tubulin III and Nestin, when there is Rosmarinic acid, may indicate a greater induction of neuronal differentiation in Wharton’ s jelly stem cells. The results show that Rosmarinic acid induces the neuronal differentiation of Wharton’ s jelly stem cells.