97 research outputs found

    Design and Implementation of a Monte Carlo Framework for Assessment of Spoiler Applications in Abutting Electron Fields

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    Background: Field matching problems in abutting electron fields can be man-aged by using spoilers. Objective: The aim of this study was to design a Monte Carlo framework for the assessment of spoiler application in abutting electron fields. Material and Methods: In this experimental study, a Siemens Primus treatment head was simulated for a 5 MeV electron beam using BEAMnrc, DOSXYZnrc and EGSnrc user codes. Validation of beam model was done by measurement using a MP3-M water tank and a Semi-flex Chamber-31010 (PTW, Freiburg, Germany). An in-house routine was developed to calculate the combined isodose curves result-ing from simulated adjacent fields. The developed framework was analyzed using PMMA and chromium spoilers. Results: The penumbra width increased from 27.5 mm for open fields to 42 mm for PMMA and 40 mm for chromium. The maximum junction dose reduced from 115% for open fields to 107% for PMMA and 108% for chromium. R90 reduced about 6 mm for PMMA and 3 mm for chromium. Uniformity index reduced from 93% to 77% for both spoilers. Surface dose increased from 79% to 89% for PMMA and 88% for chromium. Conclusion: Using spoilers, penumbra width at the surface was increased, size and depth of hot spots as well as the therapeutic range were reduced and dose homo-geneity at the junction of abutting electron fields was improved. For both spoilers, the uniformity index reduced, and surface percent dose increased. The results of this research can be used to optimize dose distribution in electron beam treatment using abutting fields

    Evaluation of Therapeutic Properties of a Low Energy Electron Beam Plus Spoiler for Local Treatment of Mycosis Fungoides: A Monte Carlo Study

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    Background: When using low-energy electron beams for the treatment of skin lesions, such as Mycosis Fungoides (MF), a beam spoiler is used to decrease electron therapeutic depth (R90) while increasing the surface dose. Objective: The aim of this study was to evaluate the characteristics of a 5 MeV electron beam when using a spoiler for the local treatment of MF skin lesions by Monte Carlo (MC) simulation. Methods: A Siemens Primus treatment head and an acrylic spoiler, positioned at the end of applicator, were simulated using BEAMnrc, an EGSnrc user code. The modelled beam was validated by measurement using MP3-M water tank, Roos parallel plate chamber and Semi flex Chamber-31013 (all from PTW, Freiburg, Germany). For different spoiler thicknesses, dose distributions in water were calculated for 2 field sizes and were compared to those for the corresponding open fields. Results: For a 1.3 cm spoiler, therapeutic range changed from 1.5 cm (open field) to 0.5 cm and 0.4 cm for 10 × 10 cm2 and 20 × 20 cm2 field sizes, respectively. Maximum increase in penumbra width was 2.8 and 3.8 cm for 10 × 10 cm2 and 20 × 20 cm2 field sizes, respectively. Maximum increase in bremsstrahlung contamination was %2 in both field sizes. Conclusion: R90 decreased exponentially with increase in spoiler thickness. The effect of field size on penumbra was much larger for spoiled beam compared to the open beam. The results of this research can be applied to optimize the radiation treatment of MF patients in our hospital

    Primary immunodeficiency disorders in Iran: Update and new insights from the third report of the national registry

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    Background: Primary immunodeficiency disorders (PID) are a group of heterogeneous disorders mainly characterized by severe and recurrent infections and increased susceptibility to malignancies, lymphoproliferative and autoimmune conditions. National registries of PID disorders provide epidemiological data and increase the awareness of medical personnel as well as health care providers. Methods: This study presents the demographic data and clinical manifestations of Iranian PID patients who were diagnosed from March 2006 till the March of 2013 and were registered in Iranian PID Registry (IPIDR) after its second report of 2006. Results: A total number of 731 new PID patients (455 male and 276 female) from 14 medical centers were enrolled in the current study. Predominantly antibody deficiencies were the most common subcategory of PID (32.3 %) and were followed by combined immunodeficiencies (22.3 %), congenital defects of phagocyte number, function, or both (17.4 %), well-defined syndromes with immunodeficiency (17.2 %), autoinflammatory disorders (5.2 %), diseases of immune dysregulation (2.6 %), defects in innate immunity (1.6 %), and complement deficiencies (1.4 %). Severe combined immunodeficiency was the most common disorder (21.1 %). Other prevalent disorders were common variable immunodeficiency (14.9 %), hyper IgE syndrome (7.7 %), and selective IgA deficiency (7.5 %). Conclusions: Registration of Iranian PID patients increased the awareness of medical community of Iran and developed diagnostic and therapeutic techniques across more parts of the country. Further efforts must be taken by increasing the coverage of IPIDR via electronically registration and gradual referral system in order to provide better estimation of PID in Iran and reduce the number of undiagnosed cases. © 2014 Springer Science+Business Media

    Evaluation of Therapeutic Properties of a Low Energy Electron Beam Plus Spoiler for Local Treatment of Mycosis Fungoides: A Monte Carlo Study

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    Background: When using low-energy electron beams for the treatment of skin lesions, such as Mycosis Fungoides (MF), a beam spoiler is used to decrease electron therapeutic depth (R90) while increasing the surface dose. Objective: The aim of this study was to evaluate the characteristics of a 5 MeV electron beam when using a spoiler for the local treatment of MF skin lesions by Monte Carlo (MC) simulation. Material and Methods: In this experimental study, a Siemens Primus treatment head and an acrylic spoiler, positioned at the end of applicator, were simu-lated using BEAMnrc, an EGSnrc user code. The modelled beam was validated by measurement using MP3-M water tank, Roos parallel plate chamber and Semi flex Chamber-31013 (all from PTW, Freiburg, Germany). For different spoiler thickness-es, dose distributions in water were calculated for 2 field sizes and were compared to those for the corresponding open fields. Results: For a 1.3 cm spoiler, therapeutic range changed from 1.5 cm (open field) to 0.5 cm and 0.4 cm for 10 × 10 cm2 and 20 × 20 cm2 field sizes, respectively. Maximum increase in penumbra width was 2.8 and 3.8 cm for 10 × 10 cm2 and 20 × 20 cm2 field sizes, respectively. Maximum increase in bremsstrahlung contamination was %2 in both field sizes. Conclusion: R90 decreased exponentially with increase in spoiler thickness. The effect of field size on penumbra was much larger for spoiled beam compared to the open beam. The results of this research can be applied to optimize the radiation treatment of MF patients in our hospital

    Expression and characterization of a novel recombinant cytotoxin II from Naja naja oxiana venom: A potential treatment for breast cancer

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    Breast cancer (BC) is among the leading causes of mortality from cancer in women. Many of the available anticancer drugs have various side effects. Therefore, researchers are seeking novel anticancer agents particularly from natural compounds and in this regard, snake venom is still one of the main sources of drug discovery. Previous studies showed potential anticancer effects of Cytotoxin II (CTII) from Naja naja oxiana against the different types of cancers. In this study, a pET-SUMO-CTII vector was transformed into SHuffle® T7 Express, an Escherichia coli strain, for recombinant protein expression (rCTII) and the cytotoxic effects of this protein was assessed in MCF-7 cells. The flow cytometry assay was applied to measure the apoptosis and cell cycle. Also, mRNA levels of the Bax, Bcl2, P53, caspase-3, caspase-8, caspase-9, caspase-10, matrix metalloproteinases (MMP)-3, and MMP-9 were analyzed by quantitative real-time PCR to determine the underlying cellular pathways affected by rCTII. The results of this study showed that treatment with 4 μg mL−1 of rCTII enhanced apoptosis through the intrinsic and extrinsic pathways. Also, the increase of the cells' proportion in the sub-G1 phase as well as a reduction in S phase was observed. In addition, the expression of MMP-3 and MMP-9 was decreased in the treated group in comparison to the control group that may contribute to the reduced migratory ability of tumor cells. These experimental results indicate that rCTII has anti-proliferative potential, and so this protein could be a potential drug for BC therapy in combination with other drugs

    Targeted Gene Panel Sequencing for Early-onset Inflammatory Bowel Disease and Chronic Diarrhea

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    Background: In contrast to adult-onset inflammatory bowel disease (IBD), where many genetic loci have been shown to be involved in complex disease etiology, early-onset IBD (eoIBD) and associated syndromes can sometimes present as monogenic conditions. As a result, the clinical phenotype and ideal disease management in these patients often differ from those in adult-onset IBD. However, due to high costs and the complexity of data analysis, high-throughput screening for genetic causes has not yet become a standard part of the diagnostic work-up of eoIBD patients. Methods: We selected 28 genes of interest associated with monogenic IBD and performed targeted panel sequencing in 71 patients diagnosed with eoIBD or early-onset chronic diarrhea to detect causative variants. We compared these results to whole-exome sequencing (WES) data available for 25 of these patients. Results: Target coverage was significantly higher in the targeted gene panel approach compared with WES, whereas the cost of the panel was considerably lower (approximately 25% of WES). Disease-causing variants affecting protein function were identified in 5 patients (7%), located in genes of the IL10 signaling pathway (3), WAS (1), and DKC1 (1). The functional effects of 8 candidate variants in 5 additional patients (7%) are under further investigation. WES did not identify additional causative mutations in 25 patients. Conclusions: Targeted gene panel sequencing is a fast and effective screening method for monogenic causes of eoIBD that should be routinely established in national referral centers.info:eu-repo/semantics/publishedVersio

    Role of oral codeine to prevent coughing following the cataract surgery

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    Background: Coughing is quite common after surgery. However, it is believed that codeine may reduce coughing, thus, the present study was conducted to determine the effects of codeine on coughing. Materials and methods: It was a double blind clinical trial performed on 150 subjects in the form of two groups. Induction and maintenance of anesthesia was similar in both groups. The case group had received 30mg of codeine phosphate one hour before the surgery, but the control group received placebo. Heart rate, and systolic and diastolic blood pressure were determined 3 minutes following the intubations and 3 minutes after the extubation. Meanwhile, number of coughs was determined right after extubation, 3 and 10 minutes later. Results: Groups were similar according to the age. Of placebo group, 23 (30.7) and of the case group 19 (25.3) had experienced severe cough (NS). The mean number of cough in the case and placebo group was 9.05±8.65 and 5.65±4.56, respectively (NS). There was no significant difference in systolic and diastolic blood pressures measured before intubation, 3 minutes after intubation and 3 minutes after extubation. Conclusion : Oral codeine failed to prevent coughing after cataract surgery. Thus, other techniques are strongly recommende

    Green synthesis of a Cu/reduced graphene oxide/Fe<sub>3</sub>O<sub>4</sub> nanocomposite using <i>Euphorbia wallichii</i> leaf extract and its application as a recyclable and heterogeneous catalyst for the reduction of 4-nitrophenol and rhodamine B

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    Herein, we describe a green and eco-friendly synthesis method for preparing a Cu/RGO/Fe3O4 nanocomposite through biological reduction of graphene oxide and Cu2+, Fe3+ ions using Euphorbia wallichii leaf extract as a reducing and stabilizing agent.</p
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