Tehran University Medical Journal

Background: Gastric cancer is among the most common malignancies in certain parts of the world, such as northwest Iran. miRNAs are small and single-stranded noncoding RNAs with about 19-23 nucleotides. Several studies have shown that miRNAs play important roles in gastric tumorigenesis. The aim of this study was to determine the effect of miRNA-1266-5p repression on the cell survival and alterations of the cell cycle in gastric cancer cell line of AGS (NCBI Code: C131, Gastric epithelial cell line).
Methods: This experimental study was performed from April to December 2017 in Cellular-Molecular Research Center of Ardabil University of Medical Sciences, Iran. In this study, AGS cells were cultured in RPMI-1640 medium containing 10% serum and 1% antibiotic. The cells were transfected with miR-1266-5p mimic, miR-1266-5p inhibitor and HiPerFect reagent alone as negative control. The miR-1266-5p expression and transfection efficiency were analyzed by Stem-loop TaqMan qRT-PCR. The cell proliferation and cell cycle alterations were determined using MTT calorimetric assay and flow cytometry, respectively. The results were analyzed using SPSS 19.0 statistics software (SPSS Inc., Chicago, IL, USA) and presented as the means±standard deviation (SD).
Results: miR-1266-5p expression was increased in AGS cells transfected with miR-1266-5p mimic compared to control cells (P=0), while miR-1266-5p expression was decreased in transfected cells with the inhibitor compared to controls (P=0). Among different time points, the most effects of miR-1266-5p mimic and inhibitor were noticed after 48 hours of transfection. The upregulated miR-1266-5p significantly decreased cell growth, in contrast, inhibitor promoted cell proliferation (P=0). In addition, miR-1266-5p upregulation induced cell cycle arrest at the transition of G1 to S phase and led to G0/G1 entry (P=0), while of miR-1266-5p led to G2/M entry (P=0.001).
Conclusion: According to the results obtained from this study, miR-1266-5p can reduce cell survival and induce cell cycle arrest and act as a tumor suppressor in AGS cells. While its inhibition can increase cell survival and reduce apoptosis.

Background: Cerebral aneurysm disease causes intracranial hemorrhage by rupturing, which can eventually, lead to organ failure or death. For this reason, it is important to anticipate the reasons for rupturing of a cerebral aneurysm from biomechanical point of view. Investigating this disease may even help the physicians to find treatments and predict the patient’s situation. This research was conducted to understand risks of development and rupture of a patient-specific cerebral aneurysm.
Methods: In a computational simulation, fluid-structure interaction method has been used for a patient-specific case. Also, considering the speed of the systole as the initial condition of the problem, the blood fluid domain has been solved in three types of fluid mathematical models (Newtonian, non-Newtonian Carreau, and non-Newtonian power-law). Then, the pressure results on the wall have been transmitted to ANSYS software, version 15.0 (ANSYS Inc., Canonsburg, PA, USA) and the structure has been solved based on three material models (linear elastic, hyperplastic Neo-Hookean and hyperplastic Mooney-Rivlin, with 5 parameters). The study was done in University of Tehran, Iran, from October 2016 to September 2018.
Results: Shear stress, pressure, flow velocity, wall displacement and von-Mises stress have been extracted from the simulations. The average wall displacement of the aneurysm was 1.8 mm. Also, no significant difference was found in the amount of arterial wall displacement, with constant wall material model and different blood models. However, a significant difference has been observed in the case of considering constant blood model and different wall material models in the value of displacement.
Conclusion: With regard to the amount of displacement of the aneurysm wall in this particular patient, with the geometry and location of the specific aneurysm, the brain nerves 3 and 6 were under stress and exposed to damage. The minimum shear stress was in the aneurysm neck, which stimulates the endothelial cells in the area of aneurysm. In addition, the blood model didn’t had a significant effect on the displacement calculations, while the wall material model played a more decisive role.

Background: Considering the high prevalence of breast masses and the importance of screening and follow-up for malignancies in women, and since age and hormonal changes during menopause play a role in determining the type of pathology and prognosis of the masses, the purpose of this study is to determine the relationship between menopause and mass pathology.
Methods: This was a cross-sectional-analytical study that was conducted in order to investigate the types of pathology of breast masses and their relationship with the age of menopause in women referred to Shahid Beheshti Hospital in Qom between April 2013 and April 2019. The inclusion criteria include: having sufficient file information and having a contact number to complete personal information, no history of cancer in other parts of the body and simultaneous malignancies, and the exclusion criteria also include: samples that were taken by cellular aspiration sampling, There were women who had a history of first-degree breast malignancy and were previously diagnosed with breast cancer and there was a possibility that the new mass under study was metastatic. Finally, the patients' information was extracted from the files and recorded in pre-prepared checklists. And the supplementary information of the incomplete files was asked and completed using the contact information of the patients. After collecting the information, using SPSS software version 26 and with chi-square and t-test statistical tests and considering the significance level of 0.05 the data was analyzed.

Results: He prevalence of malignancy in postmenopausal women was higher than in premenopausal women. Also, a significant difference was found between tumor size, the presence or absence of metastasis, and menopause (P<0.05), but no significant difference was found between tumor location and menopause (P>0.05). Conclusion: Breast malignancies (invasive ductal carcinoma, invasive mixed carcinoma, mucinous, medullary, and papillary carcinoma) were more common in postmenopausal women than non-menopausal women. In both groups, ductal dilatation and chronic inflammation were the most benign findings, and fibroadenoma was found at a much lower rate in menopausal women than in non-menopausal.