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Background. The aim of this study was to use various theoretical methods derived from the Linear Quadratic (LQ) model to calculate the effects of number of subfractions, time intervals between subfractions, dose per subfraction, and overall fraction time on the cells’ survival. Comparison of the results with experimental outcomes of melanoma and breast adenocarcinoma cells was also performed. Finally, the best matched method with experimental outcomes is introduced as the most accurate method in predicting the cell response.

Background: The current study aimed to determine the trends in esophageal cancer (EC) patients and examine the impact of the type and anatomical location of the tumor and the site of metastasis on their survival. Method: In this retrospective cohort study, we investigated 305 patients with a definite diagnoses of EC, who had been hospitalized at the Mahdie Hospital of Hamadan, Iran, during ten years from 2005-2015. EC-related survival considering different types and locations of the tumor, as well as the sites of metastasis, was evaluated. Survival was calculated using Kaplan-Meier curves and a multivariable Cox regression analysis (MVA) was performed. Results: Squamous cell carcinoma was found in 76.6% of the patients and 23.4% had adenocarcinoma (AC). There was a significant relationship between the location and pathological type of tumor; 87% of ACs happened in the lower part of the esophagus (P = 0.015). The 1- to 5-year relative survival of the patients was 46%, 25%, 22%, 12%, and 7%, respectively. The rate of death in liver, lung, brain, pancreas, abdomen, and lymph nodes metastasis were respectively 42.9%, 21.4%, 14.3%, 7.1%, 7.1%, and 7.1%. No significant relationships were observed between the tumor type and metastasis (P = 0.14) or between the tumor type and the location of metastasis (P = 0.7). Conclusion: Similar to other reports, the rate of survival was higher in AC type, yet the rate of total survival in Iran was much lower than that in developed countries. There were no differences in the survival rate concerning the location of the tumor. The obtained results did not show any relationships among the tumor type, the location of metastasis, and the total survival. [ABSTRACT FROM AUTHOR]

Investigation of the effects of E-fields on the liquid-vapor interface is essential for the study of floating water bridge and wetting phenomena. The present study employs the molecular dynamics method to investigate the effects of parallel and perpendicular E-fields on thewater liquid-vapor interface. For this purpose, density distribution, number of hydrogen bonds, molecular orientation, and surface tension are examined to gain a better understanding of the interface structure. Results indicate enhancements in parallel E-field decrease the interface width and number of hydrogen bonds, while the opposite holds true in the case of perpendicular E-fields. Moreover, perpendicular fields disturb the water structure at the interface. Given that water molecules tend to be parallel to the interface plane, it is observed that perpendicular E-fields fail to realign water molecules in the field direction while the parallel ones easily do so. It is also shown that surface tension rises with increasing strength of parallel E-fields, while it reduces in the case of perpendicular E-fields. Enhancement of surface tension in the parallel field direction demonstrates how the floating water bridge forms between the beakers. Finally, it is found that application of external E-fields to the liquid-vapor interface does not lead to uniform changes in surface tension and that the liquid-vapor interfacial tension term inYoung's equation should be calculated near the triple-line of the droplet. This is attributed to the multi-directional nature of the droplet surface, indicating that no constant value can be assigned to a droplet's surface tension in the presence of large electric fields. [ABSTRACT FROM AUTHOR]

Background: Despite significant diagnosis benefits, the usage of ionizing radiation is not risk-free. The aim of this study was to determine the risk of thyroid cancer for children who exposed to brain computed tomography (CT) scan. Method: In this cross-sectional study, 90 patients under 20 years of age who underwent brain CT-scan were selected. Parameters such as age, sex, imaging technique, imaging characteristics, and thyroid absorbed dose were considered. We used SPSS software, version 21, at 95% confidence interval to analyze the absorbed dose and risk for each individual. Results: The mean and standard deviation of absorbed doses for girls and boys for the spiral technique were 3.954±0.393 and 4.72±0.000 mGy, and in sequential technique, were 2.282±0.461 and 1.985±0.431 mGy, respectively. The mean and standard deviation of the absorbed doses in <5 years age group were 5.65±2.00, 3.03±1.34 in 6 to 10 years, 2.63±0.98 in 11 to 15 years, and in 16 to 20 years were 2.57±1.04 mGy (P < 0.001). There was a significant negative correlation between the absorbed dose and field dimensions (r = -0.604, P < 0.001) and slice thickness (r = - 0.777, P < 0.001). The mean and standard deviation of Lifetime risk for thyroid cancer induction (x 105) in <5 years age group in spiral technique was 158.79±322.50 for female subjects and 16.5±42.90 for male patients, which was significantly more than those of other groups and techniques (P < 0.001). Conclusion: The rate of thyroid absorbed dose during brain CT-scan was found to be noticeable, especially in spiral CT imaging, for female patients < 5 years. Based on our results, it was associated with an increased risk of thyroid cancer in this age group. [ABSTRACT FROM AUTHOR]

This study investigated the effect of various magnetic flux densities of extremely low frequency electromagnetic fields (ELF-EMF) on expression of T-box transcription factor (T-bet) and GATA binding protein-3 (GATA-3) genes in the spleen and thymus of rats injected with human serum albumin (HSA). Moreover, serum levels of interferon (IFN)-γ and interleukin (IL)-4 were evaluated at two phases, that is, prestimulation and poststimulation with HSA. Eighty rats were separated into five groups, and four groups were exposed daily to 50 Hz EMF of 1, 100, 500, and 2000 μT magnetic flux densities for 60 days. To activate the immune system, 100 μg HSA was intraperitoneally injected into each rat on days 31, 44, and 58 of the regimen. Splenic and thymic T-bet and GATA-3 messenger RNA (mRNA) expression on day 61 was evaluated by reverse transcription quantitative PCR. Serum IFN-γ and IL-4 (in blood on day 31 before HSA and again on day 61) levels were evaluated by enzyme-linked immunosorbent assay. Expression of T-bet and GATA-3 mRNA was decreased in the spleen in hosts exposed to densities of 1 and 100 μT. Serum IFN-γ and IL-4 levels were also significantly decreased in 100 μT-exposed rats, but only at the prestimulation phase. From these findings, it appears that (30 and 60 days) ELF-EMF exposure could suppress the expression of some key genes associated with T helper (Th) cells and on some of their associated functions, that is, the ability to generate (in some cases, spontaneously) select cytokines. Whether this is attributable to effects on Th1/Th2 levels in the hosts and/or due to potential effects of the EMF on cellular functions remains to be determined. [ABSTRACT FROM AUTHOR]

PurposeTo investigate the effect of increasing the overall treatment time as well as delivering the compensating doses on the Balb/c breast adenocarcinoma (4T1) tumor. Materials and methodsA total of 72 mice were divided into two aliquots (classes A and B) based on the initial size of their induced tumor. Each class was divided into a control and several treatment groups. Among the treatment groups, group 1 was continuously exposed to 2 Gy irradiation, and groups 2 and 3 received two subfractions of 1 Gy over the total treatment times of 30 and 60 min, respectively. To investigate the effect of compensating doses, calculated based on the developed linear quadratic model (LQ) model, the remaining two groups (groups 4 and 5) received two subfractions of 1.16 and 1.24 Gy over the total treatment times of 30 and 60 min, respectively. The growing curves, Tumor Growth Time (TGT), Tumor Growth Delay Time (TGDT) and the survival of the animals were studied. ResultsFor class A (tumor size ≤ 30 mm3), the average tumor size in the irradiated groups 1–5 was considerably different compared to the control group as one unit (day) change in time, by amount of −160.8, −158.9, +39.4 and +44.0, respectively. While these amounts were +22.0, +17.9, −21.7 and −0.1 for class B (tumor size ≥ 400 mm3). For the class A of animals, the TGT and TGDT parameters were significantly lower (0 ≤ 0.05) for the groups 2 and 3, compared to group 1. There was no significant difference (p > 0.05) between groups 1, 4 and 5 in this class. There was no significant difference (p > 0.05) between all the treated groups in class B. ConclusionsIncreasing total treatment time affects the radiobiological efficiency of treatment especially in small-sized tumor. The compensating doses derived from the LQ model can be used to compensate the effects of prolonged treatment times atin vivocondition. [ABSTRACT FROM PUBLISHER]

Herein, iron-gold core shell magnetic nanoparticles Fe@Au NPs was investigated as contrasting agent in radiation therapy in the breast cancer. Assessment of cytotoxic and radio sensitizing potential was done by MTT method and Flow cytometry. Radiation was done using Co 60 source. The response of cells to treatment with radiation alone and radiation with nanoparticles was assessed. The study demonstrates that Fe@Au nanoparticles do not have considerable cytotoxic effects, but they increase the effectiveness of radiation that means the survival of the group without nanoparticles exposed to 5 Gy radiations is 75%while the group with nanoparticles is 33%. With 2 Gy radiations the survival of the two groups are 87% and 80% respectively. [ABSTRACT FROM AUTHOR]

Background: Super-paramagnetic iron oxide nanoparticles (SPION) contain a chemotherapeutic drug and are regarded as a promising technique for improving targeted delivery into cancer cells. Results: In this study, the fabrication of 5-fluorouracil (5-FU) was investigated with loaded Dextran (DEXSPION) using the co-precipitation technique and conjugated by folate (FA). These nanoparticles (NPs) were employed as carriers and anticancer compounds against liver cancer cells in vitro. Structural, magnetic, morphological characterization, size, and drug loading activities of the obtained FA-DEX-5-FUSPION NPs were checked using FTIR, VSM, FESEM, TEM, DLS, and zeta potential techniques. The cellular toxicity effect of FA-DEX-5-FU-SPION NPs was evaluated using the MTT test on liver cancer (SNU-423) and healthy cells (LO2). Furthermore, the apoptosis measurement and the expression levels of NF-1, Her-2/neu, c-Raf-1, and Wnt-1 genes were evaluated post-treatment using flow cytometry and RT-PCR, respectively. The obtained NPs were spherical with a suitable dispersity without noticeable aggregation. The size of the NPs, polydispersity, and zeta were 74 ± 13 nm, 0.080 and -45 mV, respectively. The results of the encapsulation efficiency of the nano-compound showed highly colloidal stability and proper drug maintenance. The results indicated that FA-DEX-5-FU-SPION demonstrated a sustained release profile of 5-FU in both phosphate and citrate buffer solutions separately, with higher cytotoxicity against SNU-423 cells than against other cells types. These findings suggest that FA-DEX-SPION NPs exert synergistic effects for targeting intracellular delivery of 5-FU, apoptosis induction, and gene expression stimulation. Conclusions: The findings proved that FA-DEX-5-FU-SPION presented remarkable antitumor properties; no adverse subsequences were revealed against normal cells. [ABSTRACT FROM AUTHOR]

Background: Usually, chemoradiotherapy can be used for the treatment of locally advanced colorectal cancer (CRC) before surgery. On the other hand, some studies have shown that fractional radiation of tumor cells leads to chemoresistance. The aim of this study was to evaluate the chemoresistance of radioresistant sub-line (RR sub-line). Methods: This study was done in Hamadan University of Medical Sciences in 2017-2018. MTT assay and sub-G1 fraction analysis by flow cytometry were used to evaluate crossresistance of RR sub-line to gefitinib and regorafenib. Real-time PCR was used to investigate the role of four miRNAs and their target genes in the cross-resistance of RR sub-line. The t test and repeated measures test were used for the assessment of statistical significance between groups. Results: The IC50 of gefitinib and regorafenib for RR sub-line were significantly higher than those of the parental cell line. On the other hand, the resistance index of RR sub-line for gefitinib and regorafenib were 1.92 and 1.44, respectively. The sub-G1 fraction of RR sub-line following treatment with gefitinib and regorafenib was significantly lower than that of the parental cell line (P=0.012 and P=0.038, respectively). The expression of miR-9, Let-7e, and Let-7b in RRsub-line was significantly lower than that of the parental cell line. However, NRAS, IGF1R, NFKB1, and CCND1 found to be upregulated in RR sub-line in comparison with the parental cell line. Conclusion: We can conclude that the acquired RR sub-line was cross-resistance to gefitinib and regorafenib. Furthermore, miR-9/NFKB1, let-7b/CCND1, let-7e/NRAS, and IGF1R played essential roles in the chemoradioresistance of CRC. [ABSTRACT FROM AUTHOR]