Search results for "Dose"
showing 10 items of 2247 documents
Technical development in cardiac CT: current standards and future improvements—a narrative review
2020
Non-invasive depiction of coronary arteries has been a great challenge for imaging specialists since the introduction of computed tomography (CT). Technological development together with improvements in spatial, temporal, and contrast resolution, progressively allowed implementation of the current clinical role of the CT assessment of coronary arteries. Several technological evolutions including hardware and software solutions of CT scanners have been developed to improve spatial and temporal resolution. The main challenges of cardiac computed tomography (CCT) are currently plaque characterization, functional assessment of stenosis and radiation dose reduction. In this review, we will discu…
Dihydrocucurbitacin B, isolated from Cayaponia tayuya, reduces damage in adjuvant-induced arthritis
2005
23,24-Dihydrocucurbitacin B, from the anti-rheumatic plant Cayaponia tayuya, was tested on arthritis induced by adjuvant to corroborate the anti-inflammatory properties of this plant. Arthritis was induced in Lewis rats; the resulting arthritic rats were then treated with dihydrocucurbitacin B (1 mg/kg orally, daily, 1 week). The effect of dihydrocucurbitacin B on the synthesis, release, and activity of pro-inflammatory enzymes (elastase, cyclooxygenase-2, and nitric oxide synthase-2) as well as its effect on different mediators (tumor necrosis factor-alpha and interleukin-1beta) were determined. Dihydrocucurbitacin B modified the evolution of the clinical symptoms, reducing the swelling an…
Hyperglycemia and oxidative stress in cultured endothelial cells – a comparison of primary endothelial cells with an immortalized endothelial cell li…
2012
Diabetes mellitus is a major risk factor for the development of cardiovascular disease and oxidative stress plays an important role in this process. Therefore, we investigated the effects of hyperglycemia on the formation of reactive oxygen species (ROS) and nitric oxide/cGMP signaling in two different endothelial cell cultures. Human umbilical vein endothelial cells (HUVEC) and EA.hy 926 cells showed increased oxidative stress and impaired NO-cGMP signaling in response to hyperglycemia. The major difference between the two different cell types was the dramatic decrease in viability in HUVEC whereas EA.hy cells showed rather increased growth under hyperglycemic conditions. Starvation led to…
Interferon for non-A, non-B chronic hepatitis
1991
Abstract We reviewed randomised clinical trials evaluating the effect of lymphoblastoid or recombinant α-interferon in non-A, non-B chronic hepatitis. The outcomes assessed were the rates of serum alanine aminotransferase normalization and relapse during and after stopping interferon. Data were pooled by meta-analysis and a 50% overall rate difference, favouring treated patients, was found. Results showed homogeneity in direction of treatment effect both after short-term (2–6 months, ≥ 2 mega-units thrice weekly) and long-term (9–18 months, variable dose) interferon course. Moreover, results did not change when type of publication (abstracts vs. full reports) and treatment duration or sched…
Rhein stimulates active chloride secretion in the short-circuited rat colonic mucosa.
1988
In a short-circuited mucosa-submucosa preparation of the rat descending colon with preserved Meissner's plexus mounted as an everted sac rhein transiently increased the potential difference and short-circuit current (Isc) when administered serosally and mucosally, but serosal application was more effective. Maximal effects were obtained at rhein concentrations of 1.6 X 10(-4) and 3 X 10(-4) mol/l. Net chloride absorption was decreased. Indomethacin (5 X 10(-6) mol/l) did not inhibit the increase of Isc, but omission of calcium from the serosal side as well as tetrodoxin (2 X 10(-7) mol/l) decreased it by 50 and 60%. Mechanical removal of Meissner's plexus partly blocked the effect of rhein,…
Technical note: Dosimetric study of a new Co-60 source used in brachytherapy
2007
The purpose of this study is to obtain the dosimetric parameters of a new Co-60 source used in high dose rate brachytherapy and manufactured by BEBIG (Eckert & Ziegler BEBIG GmbH, Germany). The Monte Carlo method has been used to obtain the dose rate distribution in the updated TG-43U1 formalism of the American Association of Physicists in Medicine. In addition, to aid the quality control process on treatment planning systems (TPS), a two-dimensional rectangular dose rate table, coherent with the TG-43U1 dose calculation formalism, is given. These dosimetric data sets can be used as input data of the TPS calculations and to validate them.
SU-FF-T-41: Monte Carlo Dosimetric Study of the New BEBIG Co-60 HDR Source
2005
Purpose: The use of high dose rate brachytherapy (HDR) is a highly extended practice today, being the Ir‐192 the most widely extended isotope used for this type of practice although Co‐60 is also available for HDR. The purpose of this study is to obtain the dosimetric parameters of the Co‐60 source used by the BEBIG MultiSource remote afterloader (BEBIG GmbH, Germany) for which there is no dosimetric data available in the literature. It is recommended that accurate dose distribution data, based on a realistic geometry and on the mechanical characteristics of the source, should be obtained by an appropriate method, experimental or Monte Carlo, to be used as input in the HDR Treatment Plannin…
Monte Carlo study of the dose rate distributions for the Ir2.A85-2 and Ir2.A85-1 Ir-192 afterloading sources
2008
The two most commonly used modalities of cancer treatment in clinical brachytherapy practice today are high dose rate (HDR) and pulsed dose rate (PDR) brachytherapy. In a clinical treatment, quality dose rate distribution data sets of the brachytherapy sources are required for each source model. The purpose of this study is to obtain detailed dose rate distributions around the new BEBIG HDR and PDR Ir-192 brachytherapy sources. These distributions will then be used as input data in the treatment planning systems dedicated to brachytherapy and its calculations can be verified. The Monte Carlo method was used to obtain the dose rate distributions around the sources studied, taking into accoun…
Clinical indications for cardiac computed tomography. From the Working Group of the Cardiac Radiology Section of the Italian Society of Medical Radio…
2012
"\"La tomografia computerizzata del cuore (CCT) è diventata uno strumento efficace in differenti contesti clinici. Lo sviluppo della tecnologia ha portato ad una progressiva espansione delle indicazioni con una concomitante riduzione della dose di radiazioni necessaria per l’esecuzione dell’indagine. Ancora oggi sono pochi i documenti delle maggiori società scientifiche internazionali che si esprimono sulle effettive modalità di utilizzo e sulle indicazioni cliniche della CCT; in particolare mancano delle linee guida complete. Questo documento rispecchia la visione del gruppo di lavoro della Sezione di Cardio-Radiologia della Società Italiana di Radiologia Medica in merito alle indicazioni …
Medication errors and risk areas in a critical care unit
2020
The aim of this study was to identify the main medication errors, their causality and the highest risk areas in critical care.A descriptive, longitudinal and retrospective study.We performed a systematic analysis of the prescription, transcription and administration records of 2,634 dose units of medications that were administered to a total of 87 critically ill patients during 2018.Final results have shown important medication errors and a high number of significant drug interactions; prescription phase had the highest mistake rate (71%) and cause of errors (68%); transcription stage had a more variable error typology. A significant correlation was observed between the presence of causes a…