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Dose reference levels

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https://www.readbyqxmd.com/read/29781838/a-new-dual-purpose-quality-control-dosimetry-protocol-for-diagnostic-reference-level-determination-in-computed-tomography
#1
Mehdi Sohrabi, Masoumeh Parsi, Sedigheh Sina
A diagnostic reference level is an advisory dose level set by a regulatory authority in a country as an efficient criterion for protection of patients from unwanted medical exposure. In computed tomography, the direct dose measurement and data collection methods are commonly applied for determination of diagnostic reference levels. Recently, a new quality-control-based dose survey method was proposed by the authors to simplify the diagnostic reference-level determination using a retrospective quality control database usually available at a regulatory authority in a country...
May 17, 2018: Health Physics
https://www.readbyqxmd.com/read/29779919/radiation-dose-constraints-for-organs-at-risk-in-neuro-oncology-the-european-particle-therapy-network-consensus
#2
REVIEW
Maarten Lambrecht, Daniëlle B P Eekers, Claire Alapetite, Neil G Burnet, Valentin Calugaru, Ida E M Coremans, Piero Fossati, Morten Høyer, Johannes A Langendijk, Alejandra Méndez Romero, Frank Paulsen, Ana Perpar, Laurette Renard, Dirk de Ruysscher, Beate Timmermann, Pavel Vitek, Damien C Weber, Hiske L van der Weide, Gillian A Whitfield, Ruud Wiggenraad, Erik Roelofs, Petra Witt Nyström, Esther G C Troost
PURPOSE: For unbiased comparison of different radiation modalities and techniques, consensus on delineation of radiation sensitive organs at risk (OARs) and on their dose constraints is warranted. Following the publication of a digital, online atlas for OAR delineation in neuro-oncology by the same group, we assessed the brain OAR-dose constraints in a follow-up study. METHODS: We performed a comprehensive search to identify the current papers on OAR dose constraints for normofractionated photon and particle therapy in PubMed, Ovid Medline, Cochrane Library, Embase and Web of Science...
May 17, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29777902/chemical-characterization-and-cerebroprotective-effect-of-methanolic-root-extract-of-colebrookea-oppositifolia-in-rats
#3
Gollapalle Lakshminarayanashastry Viswanatha, Marikunte V Venkataranganna, Nunna Bheema Lingeswara Prasad, Shylaja Hanumanthappa
ETHNOPHARMACOLOGICAL RELEVANCE: Colebrookea oppositifolia Smith is one of the extensively used plants to treat neurological conditions such as epilepsy by the various ethnic communities in sub-Himalayan regions of India such as Bhoxa, Tharu and nomadic Gujjars. AIM OF THE STUDY: This study was conducted to evaluate the cerebroprotective effect of C. oppositifolia methanolic root (MeCO) extract in Wistar rats. MATERIALS AND METHODS: The MeCO was characterized for total phenolic content and later subjected for detailed liquid chromatography-mass spectrometry analysis...
May 16, 2018: Journal of Ethnopharmacology
https://www.readbyqxmd.com/read/29777831/microcystis-bloom-containing-microcystin-lr-induces-type-2-diabetes-mellitus
#4
Qiong Zhang, Wendi Qin, Liuyan Yang, Jing An, Xuxiang Zhang, Hao Hong, Lizhi Xu, Yaping Wang
Epidemiological data from Lake Taihu showed significantly higher incidences of type 2 diabetes mellitus (T2DM) than in other areas of China. This may be related to the occurrence of a Microcystis bloom in Lake Taihu in the summer and autumn every year. The objective of this study is to investigate whether the contaminated water from the Microcystis bloom and the derivative pollutant microcystin-LR (MC-LR) can explain the higher incidences of T2DM. Healthy male mice were fed with water from different regions of Lake Taihu, and were either acutely or chronically exposed to MC-LR through oral administration or intraperitoneal injection...
May 16, 2018: Toxicology Letters
https://www.readbyqxmd.com/read/29777587/epidermal-growth-factor-receptor-egfr-density-may-not-be-the-only-determinant-for-the-efficacy-of-egfr-targeted-photoimmunotherapy-in-human-head-and-neck-cancer-cell-lines
#5
Wei Peng, Henriette S de Bruijn, Eric Farrell, Mouldy Sioud, Vida Mashayekhi, Sabrina Oliveira, Go M van Dam, Jan L N Roodenburg, Max J H Witjes, Dominic J Robinson
OBJECTIVE: The aim of this study was to investigate the effects of targeted photoimmunotherapy (PIT) in vitro on cell lines with various expression levels of epidermal growth factor receptor (EGFR) using an anti-EGFR targeted conjugate composed of Cetuximab and IR700DX, phthalocyanine dye. MATERIALS AND METHODS: Relative EGFR density and cell binding assay was conducted in three human head & neck cancer cell lines (scc-U2, scc-U8, and OSC19) and one reference cell line A431...
May 19, 2018: Lasers in Surgery and Medicine
https://www.readbyqxmd.com/read/29775843/transfer-of-radionuclides-and-dose-assessment-to-ants-and-anthills-in-a-swedish-forest-ecosystem
#6
K Rosén, L Lenoir, K Stark, M Vinichuk, S Sundell-Bergman
In forest ecosystems soil organisms are important for immobilization, translocation and recycling of radionuclides. Still, there is a lack of studies on the role of insects such as ants in the turnover of radionuclides and how radioactivity affects an ant community. In this study seven anthills were sampled in an area that was heavily contaminated after the fallout from the Chernobyl accident. Samples of ant and anthill materials were taken from different depths of the anthills as well as from the surrounding soil and the activity concentrations of 137 Cs were determined...
May 15, 2018: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/29774220/serum-matrix-metalloproteinase-3-in-detecting-remitting-seronegative-symmetrical-synovitis-with-pitting-edema-syndrome-a-case-report
#7
Tsuneaki Kenzaka, Ken Goda
We report a case of remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome in a 71-year-old woman. She referred to our hospital with finger stiffness, edema of both hands and feet, pain of bilateral shoulder, wrist, metacarpophalangeal, proximal interphalangeal, and ankle joints. Rheumatoid factor was negative, human leukocyte antigen -B7 antigen was positive. Moreover, matrix metalloproteinase 3 (MMP-3) was high. She was diagnosed with RS3PE syndrome, and treatment with prednisolone (15 mg/d) was started...
May 16, 2018: World Journal of Clinical Cases
https://www.readbyqxmd.com/read/29773181/mercury-and-selenium-in-fishes-from-the-tapaj%C3%A3-s-river-in-the-brazilian-amazon-an-evaluation-of-human-exposure
#8
A S Lino, D Kasper, Y S Guida, J R Thomaz, O Malm
This work aimed to evaluate associated risks of fish consumption to human health, concerning mercury (Hg) and selenium (Se) concentrations in fish species largely consumed in the Tapajós River basin in the Brazilian Amazon. Total mercury (THg), methylmercury (MeHg) and Se concentrations were measured in 129 fish specimens from four sites of the Tapajós River basin. Estimated daily intake (EDI) of Hg and Se were reported regarding fish consumption. EDI were compared with the reference value of provisional tolerable daily intake proposed by the World Health Organization (WHO)...
July 2018: Journal of Trace Elements in Medicine and Biology
https://www.readbyqxmd.com/read/29772064/impact-of-inter-patient-variability-on-organ-dose-estimates-according-to-mird-schema-uncertainty-and-variance-based-sensitivity-analysis
#9
Alexandra Zvereva, Florian Kamp, Helmut Schlattl, Maria Zankl, Katia Parodi
PURPOSE: Variance-based sensitivity analysis (SA) is described and applied to the radiation dosimetry model proposed by the Committee on Medical Internal Radiation Dose (MIRD) for the organ-level absorbed dose calculations in nuclear medicine. The uncertainties in the dose coefficients thus calculated are also evaluated. METHODS: A Monte Carlo approach was used to compute first-order and total-effect SA indices, which rank the input factors according to their influence on the uncertainty in the output organ doses...
May 17, 2018: Medical Physics
https://www.readbyqxmd.com/read/29770154/effects-of-platycodin-d-on-reflux-esophagitis-due-to-modulation-of-antioxidant-defense-systems
#10
Su-Yeon Cho, Chang-Hyun Song, Ji-Eun Lee, Seong Hun Choi, Sae-Kwang Ku, Soo-Jin Park
Aims: The effects of platycodin D (PD) pretreatment were examined in reflux esophagitis (RE) induced rats. Methods: Sham, control, and omeprazole (OMP) group were pretreated with distilled water or OMP as a reference, respectively, and PD pretreated groups were given 3 different PD doses once a day for 7 days. One hour after last pretreatment, RE was induced by ligation of the forestomach and pylorus. At 8 h after operation, all animals were sacrificed. Results: PD showed significant dose-dependent reduction of gastric secretion, myeloperoxidase activity, and RE lesion areas of esophagus and stomach mucosa...
2018: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/29769433/medical-imaging-dose-optimization-from-ground-up-expert-opinion-of-an-international-summit
#11
Ehsan Samei, Hannu Jarvinen, Mika Kortesniemi, Georgios Simantirakis, Charles Goh, Anthony Wallace, Eliseo Vano, Adrian Bejan, M M Rehani, J Vassileva
As in any medical intervention, there is either a known or an anticipated benefit to the patient from undergoing a medical imaging procedure. This benefit is generally significant as demonstrated by the manner in which medical imaging has transformed clinical medicine. At the same time, when it comes to imaging that deploys ionizing radiation, there is a potential associated risk from radiation. Radiation risk has been recognized as a key liability in the practice of medical imaging, creating a motivation for radiation dose optimization...
May 17, 2018: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
https://www.readbyqxmd.com/read/29762057/comparison-of-image-quality-and-radiation-exposure-between-conventional-imaging-and-gemstone-spectral-imaging-in-abdominal-ct-examination
#12
Tianqi Fang, Wei Deng, Martin Wai-Ming Law, Liangping Luo, Liyun Zheng, Ying Guo, Hanwei Chen, Bingsheng Huang
OBJECTIVE: To compare patients' image quality and radiation exposure between gemstone spectral imaging (GSI) with rapid kV switching technique and conventional polychromatic imaging performed in abdominal CT examinations. METHODS: Adult patients who were referred to abdominal CT from October 2015 to March 2016 were enrolled. Unenhanced CT with conventional polychromatic imaging mode and tri-phase (arterial/portal/delayed phase) contrast-enhanced scan with GSI mode were performed with different protocols respectively...
May 15, 2018: British Journal of Radiology
https://www.readbyqxmd.com/read/29761211/comparative-study-of-uma-jeunesse-classic-%C3%A2-and-uma-jeunesse-ultra-%C3%A2
#13
Peeyush P Sharma, Dave Krishan Sharma, Andrew Carr
INTRODUCTION: The emergence of hyaluronic acid dermal fillers with lidocaine has transformed the minimally invasive treatment of wrinkles, lines and folds of the face. Patients can be treated quickly, painlessly and without the need for large doses of lidocaine. Therefore, it is important to scientifically evaluate the merits of lidocaine-containing products over those without. METHODS: The two products, with (UJU) and without lidocaine (UJ), were randomly injected into nasolabial folds of 75 healthy volunteers with varying skin types in a split face study, age ranging 26-60 years...
May 14, 2018: Aesthetic Plastic Surgery
https://www.readbyqxmd.com/read/29758313/flavonoids-as-protective-agents-against-oxidative-stress-induced-by-gentamicin-in-systemic-circulation-potent-protective-activity-and-microbial-synergism-of-luteolin
#14
Pamela Soledad Bustos, Romina Deza-Ponzio, Paulina Laura Páez, José Luis Cabrera, Miriam Beatriz Virgolini, María Gabriela Ortega
The flavonoids effect on gentamicin (GEN)-induced oxidative stress (OS) in systemic circulation was evaluated in terms of reactive oxygen species (ROS) production, enzymatic antioxidant defenses superoxide dismutase (SOD) and catalase (CAT), and lipid peroxidation (LP) in vitro on human leukocytes and in vivo on rat whole blood. The inhibitory activity of ROS was ATS < QTS < isovitexin < vitexin < luteolin. Luteolin, the most active, showed more inhibition in ROS production than vitamin C (reference inhibitor) in mononuclear cells and a slightly lower protective behavior compared to this inhibitor in polymorphonuclear cells...
May 11, 2018: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/29757158/origins-of-the-changing-detector-response-in-small-megavoltage-photon-radiation-fields
#15
John D Fenwick, Georgios Georgiou, Carl Graham Rowbottom, Tracy S A Underwood, Sudhir Kumar, Alan E Nahum
Differences in detector response between measured small fields, fclin, and wider reference fields, fmsr, can be overcome by using correction factors or by designing detectors with field-size invariant responses. The changing response in small fields is caused by perturbations of the electron fluence within the detector sensitive volume. For solid-state detectors, it has recently been suggested that these perturbations might be caused by the non-water-equivalent effective atomic numbers Z of detector materials, rather than by their non-water-like densities...
May 14, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29753411/solar-particle-event-storm-shelter-requirements-for-missions-beyond-low-earth-orbit
#16
REVIEW
L W Townsend, J H Adams, S R Blattnig, M S Clowdsley, D J Fry, I Jun, C D McLeod, J I Minow, D F Moore, J W Norbury, R B Norman, D V Reames, N A Schwadron, E J Semones, R C Singleterry, T C Slaba, C M Werneth, M A Xapsos
Protecting spacecraft crews from energetic space radiations that pose both chronic and acute health risks is a critical issue for future missions beyond low Earth orbit (LEO). Chronic health risks are possible from both galactic cosmic ray and solar energetic particle event (SPE) exposures. However, SPE exposures also can pose significant short term risks including, if dose levels are high enough, acute radiation syndrome effects that can be mission- or life-threatening. In order to address the reduction of short term risks to spaceflight crews from SPEs, we have developed recommendations to NASA for a design-standard SPE to be used as the basis for evaluating the adequacy of proposed radiation shelters for cislunar missions beyond LEO...
May 2018: Life Sciences in Space Research
https://www.readbyqxmd.com/read/29753270/estimating-acute-and-chronic-exposure-of-children-and-adults-to-chlorpyrifos-in-fruit-and-vegetables-based-on-the-new-lower-toxicology-data
#17
Patrycja Mojsak, Bożena Łozowicka, Piotr Kaczyński
This paper presents, for the first time, results for chlorpyrifos (CHLP) in Polish fruits and vegetables over the course of a long period of research, 2007-2016, with toxicological aspects. The challenge of this study was to re-evaluate the impact of chlorpyrifos residues in fruit and vegetables on health risk assessed via acute and chronic exposure based on old and new, lower, established values of: Average Daily Intakes (ADIs)/Acute Reference Doses (ARfDs) and Maximum Residue Levels (MRLs). A total of 3 530 samples were collected, and CHLP in the range of 0...
May 9, 2018: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/29752742/j-difference-edited-mrs-measures-of-%C3%AE-aminobutyric-acid-before-and-after-acute-caffeine-administration
#18
Georg Oeltzschner, Helge J Zöllner, Marc Jonuscheit, Rotem S Lanzman, Alfons Schnitzler, Hans-Jörg Wittsack
PURPOSE: The aim of this study was to investigate potential effects of acute caffeine intake on J-difference-edited MRS measures of the primary inhibitory neurotransmitter γ-aminobutyric acid (GABA). METHODS: J-difference-edited Mescher-Garwood PRESS (MEGA-PRESS) and conventional PRESS data were acquired at 3T from voxels in the anterior cingulate and occipital area of the brain in 15 healthy subjects, before and after oral intake of a 200-mg caffeine dose. MEGA-PRESS data were analyzed with the MATLAB-based Gannet tool to estimate GABA+ macromolecule (GABA+) levels, while PRESS data were analyzed with LCModel to estimate levels of glutamate, glutamate+glutamine, N-acetylaspartate, and myo-inositol...
May 12, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29749718/bioequivalence-evaluation-of-two-oral-formulations-of-acetaminophen-in-healthy-subjects-results-from-a-randomized-single-blind-crossover-study
#19
Luis García Aguirre, Carlos Bohorquez Nassar, Isabel Ruiz Olmedo, Lara Dennie, Araceli G Medina Nolasco
Despite widespread availability of acetaminophen in Mexico, data on its pharmacokinetic properties in Mexican populations are limited. This single-center, single-blind, randomized, 2-period, 2-treatment, crossover, single-dose-per-period, 2-sequence study evaluated the bioequivalence of a test acetaminophen product available in Mexico compared with a reference 500-mg acetaminophen product in 28 healthy adults under fasting conditions. Blood samples were collected predose and at specified intervals across a 16-hour period following administration and were analyzed for acetaminophen using a validated reverse-phase high-performance liquid chromatography method...
May 11, 2018: Clinical Pharmacology in Drug Development
https://www.readbyqxmd.com/read/29742927/tetracaine-induces-apoptosis-through-a-mitochondrion-dependent-pathway-in-human-corneal-stromal-cells-in-vitro
#20
Zhan Song, Ting-Jun Fan
PURPOSE: Tetracaine is a local anesthetic widely used in ocular diagnosis and ophthalmic surgery and may lead to some adverse effects and complications at a clinical dose. To assess the cytotoxicity and molecular toxicity mechanisms of tetracaine, we used human corneal stromal (HCS) cells as an in vitro model to study the effects of tetracaine on HCS cells. MATERIALS AND METHODS: The cytotoxicity of tetracaine on HCS cells was investigated by examining the changes of cell growth, morphology, viability and cell cycle progressing when HCS cells were treated with tetracaine at concentrations from 10 g/L to 0...
May 9, 2018: Cutaneous and Ocular Toxicology
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