Risk perception and avoidance of preventive behavior on the COVID-19 among cancer patients.

Background and Aims: Willingness to engage in preventive behaviors against coronavirus disease 2019 (COVID-19) depends on people's risk perception. This is especially important in cancer patients who are at risk of complications from the disease. Therefore, this study was conducted to investigate avoidance of COVID-19 preventive behavior of in cancer patients. Methods: This cross-sectional analytical study was done with 200 cancer patients who were selected by convenience sampling method. The study was conducted in Imam Khomeini Hospital of Ardabil, Iran from July to August 2020. A researcher-made questionnaire was used to investigate the risk perception of cancer patients towards COVID-19 with seven subscales according to the Extended Parallel Process Model. Data were analyzed by SPSS 20 using Pearson correlation and linear regression tests. Results: The mean and standard deviation of the age of 200 participants (including 109 men and 91 women) was 48 ± 17. Results showed that the response efficacy (12.6 ± 2.2) had the highest mean and defensive avoidance (8 ± 2.8) had the lowest mean score among EPPM constructs. Linear regression results showed that fear (ß = 0.242, p > 0.001), and perceived severity (ß = 0.191, p = 0.008) were significant predictors of defensive avoidance. Conclusion: Perceived severity and fear were significant predictors of defensive avoidance, and providing accurate and reliable news and information can be effective in reducing fear and promoting preventive behaviors.

Evaluating the effects of metal artifacts on dose distribution of the pelvic region.

AIM OF THE STUDY: Some cancerous patients have hip prosthesis of metal elements when they undergo radiation therapy. Metal implants are a cause of metal artifacts in computed tomography (CT) images due to their higher density compared to normal tissues. The aim of this study is to evaluate the quantitative effects of metal artifacts on dose distribution of the pelvic region. MATERIALS AND METHODS: Seven patients with metal implants in the pelvic region were scanned and CT images were exported to the Monaco treatment planning system. Based on the diagnosis of each patient, three-dimensional plans were implemented on CT images and dose distributions were extracted. At the next step, metal artifacts were contoured and electron densities of these new structures were modified to the extent of soft tissue. Finally, dose distributions and the differences were investigated by VeriSoft software. RESULTS: The results of this study showed that if the electron density to metal artifacts is not assigned properly, it will increase the calculated monitor units (MUs) by almost 3.78 MUs/fraction which will significantly affect total dose distribution of treatment. CONCLUSION: For the precise implementation of the treatment and in order to minimize the systematic errors related to the calculated MUs, necessary corrections on the electron density of metal artifacts should be considered before the treatment planning. The issue will be more critical in advanced treatment modalities where dose escalation is needed.

Flavonoid-Based Cancer Therapy: An Updated Review.

As cancers are one of the most important causes of human morbidity and mortality worldwide, researchers try to discover novel compounds and therapeutic approaches to decrease survival of cancer cells, angiogenesis, proliferation and metastasis. In the last decade, use of special phytochemical compounds and flavonoids was reported to be an interesting and hopeful tactic in the field of cancer therapy. Flavonoids are natural polyphenols found in plant, fruits, vegetables, teas and medicinal herbs. Based on reports, over 10,000 flavonoids have been detected and categorized into several subclasses, including flavonols, anthocyanins, flavanones, flavones, isoflavones and chalcones. It seems that the anticancer effect of flavonoids is mainly due to their antioxidant and anti inflammatory activities and their potential to modulate molecular targets and signaling pathways involved in cell survival, proliferation, differentiation, migration, angiogenesis and hormone activities. The main aim of this review is to evaluate the relationship between flavonoids consumption and cancer risk, and discuss the anti-cancer effects of these natural compounds in human cancer cells. Hence, we tried to collect and revise important recent in vivo and in vitro researches about the most effective flavonoids and their main mechanisms of action in various types of cancer cells.

Effects of guluronic acid, as a new NSAID with immunomodulatory properties on IL-17, RORγt, IL-4 and GATA-3 gene expression in rheumatoid arthritis patients.

Aim: Rheumatoid arthritis (RA) is a prevalent inflammatory, autoimmune diseases characterized by inflammation and destruction of joints. Disease-modifying anti-rheumatic drugs (DMARDs) and biological drugs can have modulatory interference in disease process. In this study, the effect of Guluronic Acid (G2013) as a novel non-steroidal anti-inflammatory drug (NSAID) with immunomodulatory effects was evaluated on IL-17, RORγt, IL-4 and GATA-3 gene expression in RA patients.Methods: Fourteen patients with RA who had an inadequate response to conventional treatments were included in this clinical trial. During this trial, patients were permitted to continue the conventional therapy excluding NSAIDs. G2013 was administered orally at dose of 500 mg twice daily for 12 weeks. The peripheral blood mononuclear cells (PBMCs) were collected before and after treatment to evaluate the gene expression levels of IL-4, GATA-3, IL-17 and RORγt.Results: Primary and secondary efficacy endpoints and Disease Activity Score (DAS) 28 showed an improvement after 12 weeks of treatment. G2013 has a potent efficacy on gene expression of these molecules, so that it could decrease IL-17 and RORγt levels and increase IL-4 and GATA-3 levels after 12 weeks of treatment. Reduction of IL-17 was statistically non-significant whereas for its transcription factor (RORγt) was statistically significant. Moreover, the gene expression results were in accordance with the clinical and preclinical assessments.Conclusion: G2013 as a natural novel drug showed a significant increase on IL-4 and GATA-3 and a significant decrease on RORγt gene expression after 12 weeks oral administration of this drug in RA patients. (Clinical trial identifier: IRCT2016092813739N5).

Protective Effect of Trans-chalcone Against High-Fat Diet-Induced Pulmonary Inflammation Is Associated with Changes in miR-146a And pro-Inflammatory Cytokines Expression in Male Rats.

High-fat diet (HFD) increases the risk of non-communicable inflammatory diseases including pulmonary disorders. Trans-chalcone is a chalcone with antioxidant and anti-inflammatory effects. This study aimed to explore the effect of this natural compound and molecular mechanism of its effect on HFD-induced pulmonary inflammation. Twenty-eight male Wistar rats were randomly divided into four main groups (n = 7 per each group): control, receiving 10% tween 80; Chal, receiving trans-chalcone, HFD, receiving a high-fat emulsion and 10% tween 80; HFD + Chal, receiving a high-fat emulsion and trans-chalcone. After 6 weeks, the lungs were dissected, and the expression levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and miR-146a were determined using real-time PCR. Moreover, histological analysis was done by hematoxylin and eosin staining. Significant elevations in TNF-α, IL-1ß, IL-6, and miR-146a expression levels (P < 0.001) were observed within the lungs of HFD-fed rats compared with the control. However, oral administration of trans-chalcone reduced TNF-α, IL-1ß, IL-6 (P < 0.001), and miR-146a (P < 0.05) expression levels and also improved HFD-induced histological abnormalities. These findings indicate that trans-chalcone ameliorates lung inflammatory response and structural alterations. It seems that this beneficial effect is associated with the down-regulation of pro-inflammatory cytokines and miR-146a.

Quercetin Promotes Cell Cycle Arrest and Apoptosis and Attenuates the Proliferation of Human Chronic Myeloid Leukemia Cell Line-K562 Through Interaction with HSPs (70 and 90), MAT2A and FOXM1.

BACKGROUND: Chronic Myeloid Leukaemia (CML) starts in certain blood-forming cells of the bone marrow when cells acquire Philadelphia chromosome. Nowadays, scientists attempt to find novel and safe therapeutic agents and approaches for CML therapy using Tyrosine Kinase Inhibitors (TKIs), CML conventional treatment agents, has some restrictions and also adverse effects. Recently, it has been proposed that phytochemicals, such as flavonoids due to their low side effects and notable safety have the potential to be used for CML therapy. MATERIALS AND METHODS: K-562 cells were exposed with three concentrations of the querectin (10, 40 and 80µM) for 12, 24 and 48 hours. After that, these cells apoptosis rate was estimated using Annexin-V/PI staining and flowcytometry analysis, and their proliferation rate was evaluated using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT). Finally, the expression of the 70 and 90 kilodalton heat shock proteins (HSP70 and 90), methionine adenosyltransferase 2A (MAT2A), Forkhead box protein M1 (FOXM1), caspase-3 and -8, Bcl-X(L) and Bax involved in leukemic cells survival and proliferation was assessed using Real-Time PCR within 12, 24 and 48 hours after exposure with quercetin 40 and 80µM. RESULTS: Considering consequences, querecetin induced apoptosis in K-562 cells, and also abrogated these cells proliferation. On the other hand, RT-PCR results showed a reduction in some of the candidate genes expression, especially HSP70, Bcl-X(L) and FOXM1, when cells were treated with quercetin 40 and 80µM. Also, Bax, caspase-3 and caspase-8 expression was significantly improved in K-562 cells upon quercetin exposure. CONCLUSION: We concluded that CML therapy by querecetin due to its anti-proliferative and anti-survival potentials could lead to the promising therapeutic outcome through targeting major survival and proliferation involved genes expression.

Epigenetic-based therapy for colorectal cancer: Prospect and involved mechanisms.

Epigenetic modifications are heritable variations in gene expression not encoded by the DNA sequence. According to reports, a large number of studies have been performed to characterize epigenetic modification during normal development and also in cancer. Epigenetics can be regarded more widely to contain all of the changes in expression of genes that make by adjusted interactions between the regulatory portions of DNA or messenger RNAs that lead to indirect variation in the DNA sequence. In the last decade, epigenetic modification importance in colorectal cancer (CRC) pathogenesis was demonstrated powerfully. Although developments in CRC therapy have been made in the last years, much work is required as it remains the second leading cause of cancer death. Nowadays, epigenetic programs and genetic change have pivotal roles in the CRC incidence as well as progression. While our knowledge about epigenetic mechanism in CRC is not comprehensive, selective histone modifications and resultant chromatin conformation together with DNA methylation most likely regulate CRC pathogenesis that involved genes expression. Undoubtedly, the advanced understanding of epigenetic-based gene expression regulation in the CRC is essential to make epigenetic drugs for CRC therapy. The major aim of this review is to deliver a summary of valuable results that represent evidence of principle for epigenetic-based therapeutic approaches employment in CRC with a focus on the advantages of epigenetic-based therapy in the inhibition of the CRC metastasis and proliferation.

Monte Carlo calculation of photo-neutron dose produced by circular cones at 18 MV photon beams.

AIM: The aim of this study is to calculate neutron contamination at the presence of circular cones irradiating by 18 MV photons using Monte Carlo code. BACKGROUND: Small photon fields are one of the most useful methods in radiotherapy. One of the techniques for shaping small photon beams is applying circular cones made of lead. Using this method in high energy photon due to neutron contamination is a crucial issue. MATERIALS AND METHODS: Initially, Varian linac producing 18 MV photons was simulated and after validating the code, various circular cones were also simulated. Then, the number of neutrons, neutron equivalent dose and absorbed dose per Gy of photon dose were calculated along the central axis. RESULTS: Number of neutrons per Gy of photon dose had their maximum value at depth of 2 cm and these values for 5, 10, 15, 20 and 30 mm circular cones were 9.02, 7.76, 7.61, 6.02 and 5.08 (n cm-2 Gy-1), respectively. Neutron equivalent doses per Gy of photon dose had their maximum at the surface of the phantom and these values for mentioned collimators were 1.48, 1.33, 1.31, 1.12 and 1.08 (mSv Gy-1), respectively. Neutron absorbed doses had their maximum at the surface of the phantom and these values for mentioned collimators sizes were 103.74, 99.71, 95.77, 81.46 and 78.20 (µGy/Gy), respectively. CONCLUSIONS: As the field size gets smaller, number of neutrons, equivalent and absorbed dose per Gy of photon increase. Also, neutron equivalent dose and absorbed dose are maximum at the surface of phantom and then these values will be decreased.