Measurement of the equivalent dose in quartz using a regenerative-dose single-aliquot protocol

International Nuclear Information System (INIS)

Murray, A.S.; Roberts, R.G.

1998-01-01

The principles behind a regenerative-dose single-aliquot protocol are outlined. It is shown for three laboratory-bleached Australian sedimentary quartz samples that the relative change in sensitivity of the optically stimulated luminescence (OSL) during a repeated measurement cycle (consisting of a dose followed by a 10 s preheat at a given temperature and then a 100 s exposure to blue/green light at 125 deg. C) is very similar to that of the 110 deg. C thermoluminescence (TL) peak measured during the preheat cycle. The absolute change in the TL sensitivity with preheat temperature is different for samples containing a natural or a regenerative dose. Furthermore, the absolute change in sensitivity in both the OSL and TL signals is non-linear with regeneration cycle, but the relative change in the OSL signal compared to the following 110 deg. C TL measurement is well approximated by a straight line. Both signals are thought to use the same luminescence centres, and so some common behaviour is not unexpected. A new regenerative-dose protocol is presented which makes use of this linear relationship to correct for sensitivity changes with regeneration cycle, and requires only one aliquot for the estimation of the equivalent dose (D e ). The protocol has been applied to quartz from nine Australian sites. To illustrate the value of the regenerative-dose single-aliquot approach, the apparent values of D e for 13 samples, containing doses of between 0.01 and 100 Gy, have been measured at various preheat temperatures of between 160 and 300 deg. C, using a single aliquot for each D e measurement. Excellent agreement is found between these single-aliquot estimates of D e and those obtained from additive-dose multiple-aliquot and single-aliquot protocols, over the entire dose range

A single-aliquot OSL protocol using bracketing regenerative doses to accurately determine equivalent doses in quartz

CERN Document Server

Folz, E

1999-01-01

In most cases, sediments show inherent heterogeneity in their luminescence behaviours and bleaching histories, and identical aliquots are not available: single-aliquot determination of the equivalent dose (ED) is then the approach of choice and the advantages of using regenerative protocols are outlined. Experiments on five laboratory bleached and dosed quartz samples, following the protocol described by Murray and Roberts (1998. Measurement of the equivalent dose in quartz using a regenerative-dose single aliquot protocol. Radiation Measurements 27, 171-184), showed the hazards of using a single regeneration dose: a 10% variation in the regenerative dose yielded some equivalent dose estimates that differed from the expected value by more than 5%. A protocol is proposed that allows the use of different regenerative doses to bracket the estimated equivalent dose. The measured ED is found to be in excellent agreement with the known value when the main regeneration dose is within 10% of the true equivalent dose.

A single-aliquot OSL protocol using bracketing regenerative doses to accurately determine equivalent doses in quartz

International Nuclear Information System (INIS)

Folz, Elise; Mercier, Norbert

1999-01-01

In most cases, sediments show inherent heterogeneity in their luminescence behaviours and bleaching histories, and identical aliquots are not available: single-aliquot determination of the equivalent dose (ED) is then the approach of choice and the advantages of using regenerative protocols are outlined. Experiments on five laboratory bleached and dosed quartz samples, following the protocol described by Murray and Roberts (1998. Measurement of the equivalent dose in quartz using a regenerative-dose single aliquot protocol. Radiation Measurements 27, 171-184), showed the hazards of using a single regeneration dose: a 10% variation in the regenerative dose yielded some equivalent dose estimates that differed from the expected value by more than 5%. A protocol is proposed that allows the use of different regenerative doses to bracket the estimated equivalent dose. The measured ED is found to be in excellent agreement with the known value when the main regeneration dose is within 10% of the true equivalent dose

Single-Dose Lignocaine-Based Blood Cardioplegia in Single Valve Replacement Patients

Directory of Open Access Journals (Sweden)

Jaydip Ramani

Full Text Available Abstract OBJECTIVE: Myocardial protection is the most important in cardiac surgery. We compared our modified single-dose long-acting lignocaine-based blood cardioplegia with short-acting St Thomas 1 blood cardioplegia in patients undergoing single valve replacement. METHODS: A total of 110 patients who underwent single (aortic or mitral valve replacement surgery were enrolled. Patients were divided in two groups based on the cardioplegia solution used. In group 1 (56 patients, long-acting lignocaine based-blood cardioplegia solution was administered as a single dose while in group 2 (54 patients, standard St Thomas IB (short-acting blood-based cardioplegia solution was administered and repeated every 20 minutes. All the patients were compared for preoperative baseline parameters, intraoperative and all the postoperative parameters. RESULTS: We did not find any statistically significant difference in preoperative baseline parameters. Cardiopulmonary bypass time were 73.8±16.5 and 76.4±16.9 minutes (P=0.43 and cross clamp time were 58.9±10.3 and 66.3±11.2 minutes (P=0.23 in group 1 and group 2, respectively. Mean of maximum inotrope score was 6.3±2.52 and 6.1±2.13 (P=0.65 in group 1 and group 2, respectively. We also did not find any statistically significant difference in creatine-phosphokinase-MB (CPK-MB, Troponin-I levels, lactate level and cardiac functions postoperatively. CONCLUSION: This study proves the safety and efficacy of long-acting lignocaine-based single-dose blood cardioplegia compared to the standard short-acting multi-dose blood cardioplegia in patients requiring the single valve replacement. Further studies need to be undertaken to establish this non-inferiority in situations of complex cardiac procedures especially in compromised patients.

In vivo assessment of the gastric mucosal tolerance dose after single fraction, small volume irradiation of liver malignancies by computed tomography-guided, high-dose-rate brachytherapy

International Nuclear Information System (INIS)

Streitparth, Florian; Pech, Maciej; Boehmig, Michael; Ruehl, Ricarda; Peters, Nils; Wieners, Gero; Steinberg, Johannes; Lopez-Haenninen, Enrique; Felix, Roland; Wust, Peter; Ricke, Jens

2006-01-01

Purpose: The aim of this study was to assess the tolerance dose of gastric mucosa for single-fraction computed tomography (CT)-guided, high-dose-rate (HDR) brachytherapy of liver malignancies. Methods and Materials: A total of 33 patients treated by CT-guided HDR brachytherapy of liver malignancies in segments II and/or III were included. Dose planning was performed upon a three-dimensional CT data set acquired after percutaneous applicator positioning. All patients received gastric protection post-treatment. For further analysis, the contours of the gastric wall were defined in every CT slice using Brachyvision Software. Dose-volume histograms were calculated for each treatment and correlated with clinical data derived from questionnaires assessing Common Toxicity Criteria (CTC). All patients presenting symptoms of upper GI toxicity were examined endoscopically. Results: Summarizing all patients the minimum dose applied to 1 ml of the gastric wall (D 1ml ) ranged from 6.3 to 34.2 Gy; median, 14.3 Gy. Toxicity was present in 18 patients (55%). We found nausea in 16 (69%), emesis in 9 (27%), cramping in 13 (39%), weight loss in 12 (36%), gastritis in 4 (12%), and ulceration in 5 patients (15%). We found a threshold dose D 1ml of 11 Gy for general gastric toxicity and 15.5 Gy for gastric ulceration verified by an univariate analysis (p = 0.01). Conclusions: For a single fraction, small volume irradiation we found in the upper abdomen a threshold dose D 1ml of 15.5 Gy for the clinical endpoint ulceration of the gastric mucosa. This in vivo assessment is in accordance with previously published tolerance data

Factors impacting short and long-term kidney graft survival: modification by single intra-operative -high-dose induction with ATG-Fresenius.

Science.gov (United States)

Kaden, Jürgen; May, Gottfried; Völp, Andreas; Wesslau, Claus

2011-01-01

A majority of recipients benefited from the intra-operative single high-dose induction (HDI) with ATG-Fresenius (ATG-F) still leaving a group of recipients who did not profit from this kind of induction. Therefore the aim of this retrospective analysis was 1st to identify the risk factors impacting short and long-term graft survival, and 2nd to assess the efficacy of this type of induction in kidney graft recipients with or without these risk factors. A total of 606 recipients receiving two different immunosuppressive treatment regimens (1st: Triple drug therapy [TDT, n=196] consisting mainly of steroids, azathioprine and cyclosporine; 2nd: TDT + 9 mg/kg ATG-F intra-operatively [HDI, n=410]) were included in this analysis and grouped according to their kidney graft survival time (short GST: ≤1 yr, n=100 and long GST: >5 yrs, n=506). The main risk factors associated with a shortened graft survival were pre-transplant sensitization, re-transplantation, rejections (in particular vascular or mixed ones) and the necessity of a long-term anti-rejection therapy. Adding ATG-F single high dose induction to TDT was more efficient in prolonging kidney graft survival than TDT alone not only in recipients without any risk factors (p<0.005) but also in recipients with at least one risk factor (p<0.021). Only in 4.6% of recipients having two or more risk factors this effect could not be demonstrated. The intra-operative single high-dose induction with ATG-F significantly improves the kidney graft survival in recipients with or without risk factors and can therefore be recommended.

The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, Andrew S.; Jain, Mayank

2012-01-01

The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely...... to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution....... This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally...

Evaluation of Geometrically Optimized Single- and Double-plane Interstitial High Dose Rate Implants with Respect to Conformality and Homogeneity

International Nuclear Information System (INIS)

Major, Tibor; Polgar, Csaba; Fodor, Janos; Takacsi-nagy, Zoltan; Mangel, Laszlo; Nemeth, Gyoergy

2003-01-01

The use of a stepping source in high dose rate brachytherapy supported with dwell-time optimization makes it possible to deviate from the classical dosimetry systems. Dose distributions of single- and double-plane implants were analysed for conformality and homogeneity at idealized target volumes. The Paris system was used for catheter positioning and target volume determination. Geometric optimization and individual dose prescription were applied. Volumetric indices and dose parameters were calculated at optimal active length, which was found to be equal to target volume length. The mean conformality, homogeneity, external volume and overdose volume indices were 0.78, 0.67, 0.22 and 0.13, respectively. The average minimum target and reference doses were 69% and 86%, respectively. Comparisons between the volumetric indices of geometrical optimized and non-optimized implants were also performed, and a significant difference was found regarding any index. The geometrical optimization resulted in superior conformality and slightly inferior homogeneity. At geometrically optimized implants, the active length can be reduced compared to non-optimized implants. Volumetric parameters and dose-volume histogram-based individual dose prescription are recommended for quantitative assessment of interstitial implants

Single- and multiple-dose pharmacokinetics and absolute bioavailability of tedizolid.

Science.gov (United States)

Flanagan, Shawn; Fang, Edward; Muñoz, Kelly A; Minassian, Sonia L; Prokocimer, Philippe G

2014-09-01

Tedizolid phosphate is a novel antibacterial under investigation for the treatment of gram-positive infections. This study was conducted to assess the pharmacokinetics, safety, and tolerability of intravenous tedizolid phosphate as well as the oral bioavailability of tedizolid phosphate. Double-blind, single-ascending dose, multiple-dose pharmacokinetics study, as well as tolerability and open-label crossover studies. Single center in the United States (Covance Clinical Research Unit, Madison, WI) between September 2009 and January 2010. Ninety healthy volunteers. Single intravenous (IV) doses of tedizolid phosphate 50 mg (lead-in) and 100-400 mg. Single oral and IV dose of tedizolid phosphate 200 mg in crossover fashion. Multiple IV doses of tedizolid phosphate 200 and 300 mg for up to 7 days. A dose-dependent increase was observed in the maximum plasma concentration (1.2-5.1 μg/ml) and the area under the concentration-time curve (17.4-58.7 μg × hr/ml) of tedizolid (the microbiologically active moiety of tedizolid phosphate) after single IV doses of tedizolid phosphate 100-400 mg. Administration of IV tedizolid phosphate 200 mg once/day for 7 days resulted in minimal (28%) tedizolid accumulation. The absolute oral bioavailability of tedizolid after a single 200-mg dose of tedizolid phosphate was 91%; pharmacokinetic parameters of tedizolid were similar with oral and IV administration. Treatment-related adverse events occurred in 41% of subjects. Most adverse events were related to infusion site and became more frequent with multiple dosing. In an additional 3-day tolerability study, IV tedizolid phosphate 200 mg and placebo were similarly tolerated, based on visual infusion phlebitis scores. These results from a population of healthy volunteers support once/day dosing of tedizolid phosphate 200 mg with both the oral and IV formulations, without the need for dose adjustment when switching administration routes. © 2014 Cubist Pharmaceuticals. Pharmacotherapy

Developing a single-aliquot protocol for measuring equivalent dose in biogenic carbonates

International Nuclear Information System (INIS)

Stirling, R.J.; Duller, G.A.T.; Roberts, H.M.

2012-01-01

Exploiting biogenic carbonates as thermoluminescence dosimeters requires an understanding of trap kinetics and an appropriate sequence with which to measure equivalent dose. The trap kinetics of two high temperature peaks (peaks II and III) from calcitic snail opercula have been investigated resulting in the calculation of lifetimes of 7.4 × 10 7 and 1.4 × 10 11 years for the two peaks respectively. Two measurement sequences, based upon changes in the application and measurement of a test dose, have been applied to peaks II and III, and though both methods were equally successful in dose recovery and production of a dose response curve some differences were observed. Primarily, the use of method 1 lead to dose dependant sensitivity change implying competition effects occurring during irradiation; method 2 did not experience this phenomenon. As a consequence method 2 was chosen as the most appropriate protocol for single-aliquot dating of this material. When assessing the TL behaviour of the two peaks, peak II performed poorly in dose recovery experiments recovering a dose 60–100% larger than that applied. Disproportionate growth of peak II in response to a beta dose applied prior to measurement, compared to growth following regeneration doses indicated that peak II was not suitable for use in single-aliquot protocols. However, dose recovery results for peak III were all within errors of unity of the given dose, and peak III was therefore chosen as the most appropriate peak for TL dosimetry in these single-aliquot procedures. The lifetime of charge in peak III is sufficient to date over many millions of years, and furthermore using the chosen method 2 the dose response curve has a D 0 of 3,250 ± 163 Gy allowing dating to over 3 million years.

Single toxin dose-response models revisited

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Demidenko, Eugene, E-mail: eugened@dartmouth.edu [Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Hanover, NH03756 (United States); Glaholt, SP, E-mail: sglaholt@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States); Kyker-Snowman, E, E-mail: ek2002@wildcats.unh.edu [Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH03824 (United States); Shaw, JR, E-mail: joeshaw@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Chen, CY, E-mail: Celia.Y.Chen@dartmouth.edu [Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States)

2017-01-01

The goal of this paper is to offer a rigorous analysis of the sigmoid shape single toxin dose-response relationship. The toxin efficacy function is introduced and four special points, including maximum toxin efficacy and inflection points, on the dose-response curve are defined. The special points define three phases of the toxin effect on mortality: (1) toxin concentrations smaller than the first inflection point or (2) larger then the second inflection point imply low mortality rate, and (3) concentrations between the first and the second inflection points imply high mortality rate. Probabilistic interpretation and mathematical analysis for each of the four models, Hill, logit, probit, and Weibull is provided. Two general model extensions are introduced: (1) the multi-target hit model that accounts for the existence of several vital receptors affected by the toxin, and (2) model with a nonzero mortality at zero concentration to account for natural mortality. Special attention is given to statistical estimation in the framework of the generalized linear model with the binomial dependent variable as the mortality count in each experiment, contrary to the widespread nonlinear regression treating the mortality rate as continuous variable. The models are illustrated using standard EPA Daphnia acute (48 h) toxicity tests with mortality as a function of NiCl or CuSO{sub 4} toxin. - Highlights: • The paper offers a rigorous study of a sigmoid dose-response relationship. • The concentration with highest mortality rate is rigorously defined. • A table with four special points for five morality curves is presented. • Two new sigmoid dose-response models have been introduced. • The generalized linear model is advocated for estimation of sigmoid dose-response relationship.

single dose pharmacokinetics of mefloquine in healthy nigerian

African Journals Online (AJOL)

BSN

Mefloquine 500mg single dose was administered and blood samples were collected ... particle size ODS Hypersil (HETP, Macclesfield, UK) at a pressure of 55 Mpa .... dose to area under the plasma drug concentration - time curve, assuming ...

Phase I/II trial of single-fraction high-dose-rate brachytherapy-boosted hypofractionated intensity-modulated radiation therapy for localized adenocarcinoma of the prostate.

Science.gov (United States)

Myers, Michael A; Hagan, Michael P; Todor, Dorin; Gilbert, Lynn; Mukhopadhyay, Nitai; Randolf, Jessica; Heimiller, Jeffrey; Anscher, Mitchell S

2012-01-01

A Phase I/II protocol was conducted to examine the toxicity and efficacy of the combination of intensity-modulated radiation therapy (IMRT) with a single-fraction high-dose-rate (HDR) brachytherapy implant. From 2001 through 2006, 26 consecutive patients were treated on the trial. The primary objective was to demonstrate a high rate of completion without experiencing a treatment-limiting toxicity. Eligibility was limited to patients with T stage ≤2b, prostate-specific antigen (PSA) ≤20, and Gleason score ≤7. Treatment began with a single HDR fraction of 6Gy to the entire prostate and 9Gy to the peripheral zone, followed by IMRT optimized to deliver in 28 fractions with a normalized total dose of 70Gy. Patients received 50.4Gy to the pelvic lymph node. The prostate dose (IMRT and HDR) resulted in an average biologic equivalent dose >128Gy (α/β=3). Patients whose pretreatment PSA was ≥10ng/mL, Gleason score 7, or stage ≥T2b received short-term androgen ablation. Median followup was 53 months (9-68 months). There were no biochemical failures by either the American Society of Therapeutic Radiology and Oncology or the Phoenix definitions. The median nadir PSA was 0.32ng/mL. All the 26 patients completed the treatment as prescribed. The rate of Grade 3 late genitourinary toxicity was 3.8% consisting of a urethral stricture. There was no other Grade 3 or 4 genitourinary or gastrointestinal toxicities. Single-fraction HDR-boosted IMRT is a safe effective method of dose escalation for localized prostate cancer. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

Directory of Open Access Journals (Sweden)

Kropf Siegfried

2011-09-01

Full Text Available Abstract Background To assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir. Materials and methods Fifty patients with 76 malignant liver tumors treated by computed tomography (CT-guided high-dose-rate brachytherapy (HDR-BT were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients. Results Positioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p p = 0.001 and p = 0.004, respectively. There was a significant shift of the irradiation effect towards the catheter entry site compared with the planned dose

Single-dose radiosurgical treatment for hepatic metastases - therapeutic outcome of 138 treated lesions from a single institution

International Nuclear Information System (INIS)

Habermehl, Daniel; Herfarth, Klaus K; Bermejo, Justo Lorenzo; Hof, Holger; Rieken, Stefan; Kuhn, Sabine; Welzel, Thomas; Debus, Jürgen; Combs, Stephanie E

2013-01-01

Local ablative therapies such as stereotactically guided single-dose radiotherapy or helical intensity-modulated radiotherapy (tomotherapy) with high single-doses are successfully applied in many centers in patients with liver metastasis not suitable for surgical resection. This study presents results from more than 10 years of clinical experience and evaluates long-term outcome and efficacy of this therapeutic approach. From 1997 to 2009 a total of 138 intrahepatic tumors of 90 patients were irradiated with single doses of 17 to 30 Gy (median dose 24 Gy). Median age of the patients was 64 years (range 31–89 years). Most frequent underlying tumor histologies were colorectal adenocarcinoma (70 lesions) and breast cancer (27 lesions). In 35 treatment sessions multiple targets were simultaneously irradiated (up to four lesions at once). Local progression-free (PFS) and overall survival (OS) after treatment were investigated using uni- and multiple survival regression models. Median overall survival of all patients was 24.3 months. Local PFS was 87%, 70% and 59% after 6, 12 and 18 months, respectively. Median time to local progression was 25.5 months. Patients with a single lesion and no further metastases at time of RT had a favorable median PFS of 43.1 months according to the Kaplan-Meier estimator. The type of tumor showed a statistical significant influence on local PFS, with a better prognosis for breast cancer histology than for colorectal carcinoma in uni- and multiple regression analysis (p = 0.05). Multiple regression analysis revealed no influence of planning target volume (PTV), patient age and radiation dose on local PFS. Treatment was well tolerated with no severe adverse events. This study confirms safety of SBRT in liver lesions, with 6- and 12 months local control of 87% and 70%. The dataset represents the clinical situation in a large oncology setting, with many competing treatment options and heterogeneous patient characteristics

The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

International Nuclear Information System (INIS)

Thomsen, Kristina J.; Murray, Andrew; Jain, Mayank

2012-01-01

The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution. This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally, it is an implicit assumption in such analysis that any over-dispersion is not significantly dose dependent. In this study we have undertaken laboratory investigations of the dose dependency of over-dispersion using a well-bleached modern sample with an average measured dose of 36 ± 3 mGy. This sample was prepared as heated (750 °C for 1 h), bleached and untreated portions which were then given uniform gamma doses ranging from 100 mGy to 208 Gy. We show that for these samples the relative laboratory over-dispersion is not constant as a function of dose and that the over-dispersion is smaller in heated samples. We also show that the dim grains in the distributions have a greater over-dispersion than the bright grains, implying that insensitive samples will have greater values of over-dispersion than sensitive samples.

Single dose toxicity and biodistribution studies of [18F] fluorocholine

International Nuclear Information System (INIS)

Campos, Danielle C.; Santos, Priscilla F.; Silveira, Marina B.; Ferreira, Soraya Z.; Malamut, Carlos; Silva, Juliana B. da; Souza, Cristina M.; Campos, Liliane C.; Ferreira, Enio; Araujo, Marina R.; Cassali, Geovanni D.

2013-01-01

[ 18 F]Fluorocholine ( 18 FCH) is a valuable tool for non-invasive diagnosis using positron emission tomography (PET). This radiotracer has been proven to be highly effective in detecting recurrences and staging prostate cancer, diagnoses brain, breast, and esophageal tumors and also hepatocellular carcinoma. The higher uptake of fluorocholine by malignant tumors results from increased choline kinase activity due to accelerated cell multiplication and membrane formation. According to the Brazilian Health Surveillance Agency (ANVISA), radiopharmaceuticals have to be registered before commercialization. The aim of this work was to evaluate single dose toxicity and biodistribution of 18 FCH in mice, since preclinical safety studies are required for register. Experimental procedures were approved by the Ethics Committee on Animal Use (CEUA-IPEN/SP). Single dose toxicity and biodistribution studies were conducted in Swiss mice. No signs of toxicity were observed during clinical trial. No changes in the parameters which were examined, such as: body weight, food consumption, clinical pathology parameters or lesions microscopic were noted. Biodistribution results indicated high physiological tracer uptake in kidney, liver and heart 30 min after injection. Lower activities were recorded in other organs/tissues: pancreas, intestine, spleen, bone, bladder, muscle, brain and blood. Initial preclinical investigations showed no toxic effects of 18 FCH at investigated doses and a biodistribution profile very similar to other reports in literature. This information is essential to support future human trials. (author)

High-dose gadolinium-enhanced MRI for diagnosis of meningeal metastases

International Nuclear Information System (INIS)

Kallmes, D.F.; Gray, L.; Glass, J.P.

1998-01-01

We compared high-dose (0.3 mmol/kg) and standard-dose (0.1 mmol/kg) gadolinium-enhanced MRI for diagnosis of meningeal metastases in 12 patients with suspected meningeal metastases. They were imaged with both standard-dose and high-dose gadolinium. All patients with abnormal meningeal enhancement underwent at least one lumbar puncture for cerebrospinal fluid (CSF) cytology, while patients with normal meningeal enhancement were followed clinically. All patients with negative CSF cytology also were followed clinically. A single observer reviewed all the images, with specific attention to the enhancement pattern of the meninges. Abnormal leptomeningeal enhancement was present in three cases, and abnormal pachymeningeal enhancement in three other patients. All of these patients had abnormal CSF analyses. In two of the three cases of abnormal leptomeningeal enhancement the disease was more evident on high-dose than on standard-dose imaging; in one case the abnormal enhancement was visible only on high-dose imaging. In one of the three cases with abnormal pachymeningeal enhancement, the disease was evident prospectively only with high-dose imaging. (orig.)

Single high dose intraoperative electrons for advanced stage pancreatic cancer: Phase I pilot study

International Nuclear Information System (INIS)

Goldson, A.L.; Ashaveri, E.; Espinoza, M.C.

1981-01-01

Phase I toxicity studies with intraoperative radiotherapy proved to be a feasible adjunct to surgery for unresectable malignancies of the pancreas at Howard University Hospital. There have been minimal side effects or complications related to the combination of limited surgical decompression and intraoperative radiotherapy alone. The toxic effects of intraoperative radiotherapy on normal tissues is being assessed on a dose volume basis. Doses of 2000 to 2500 rad in a single exposure to include the pancreas, regional nodes and duodenum are acceptable if the total treatment volume is less than or equal to 100 cm. The tumoricidal effects on the cancer are demonstratable when one reviews the pathological specimens that illustrate massive tumor necrosis and fibros replacement, but in all cases reviewed, viable cancer was noted. Intraoperative radiotherapy, therefore, represents a significant boost dose for resectable, partially resectable or non-resectable tumors when added to conventional external beam irradiation and/or chemotherapy. Preliminary clinical data and minimal toxicity justifies further investigation

Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration

International Nuclear Information System (INIS)

Touboul, Emmanuel; Al Halabi, Assem; Buffat, Laurent; Merienne, Louis; Huart, Judith; Schlienger, Michel; Lefkopoulos, Dimitrios; Mammar, Hamid; Missir, Odile; Meder, Jean-Francois; Laurent, Alex; Housset, Martin

1998-01-01

Purpose: Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans. Methods and Materials: From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 ± 230 mm 3 (median 968 mm 3 ; range 62-11, 250 mm 3 ). The mean minimum target dose (D min ) was 19 ± 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 ± 300 mm 3 (median 1200 mm 3 ; range 75-14 900 mm 3 ). The mean maximum dose (D max ) was 34.5 ± 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 ± 2.3 months (median 37.5; range 7-117). Results: The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 ± 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), D min by steps of 5 Gy (p = 0.005), targeted volume of the nidus (≤968 mm 3 vs. >968 mm 3 ; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the D min [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p min but does not seem to be influenced by D max and the targeted volume of the nidus

Variable dose rate single-arc IMAT delivered with a constant dose rate and variable angular spacing

International Nuclear Information System (INIS)

Tang, Grace; Earl, Matthew A; Yu, Cedric X

2009-01-01

delivered with a different dose rate, extra mode-up time (xMOT) was needed between the transitions of the successive sectors during delivery. On average, the delivery times of the CDR plans were approximately less than 1 min longer than the treatment times of the VDR plans, with an average of about 0.33 min of xMOT per sector transition. The results have shown that VDR may not be necessary for single-arc IMAT. Using variable angular spacing, VDR RapidArc plans can be implemented into the clinics that are not equipped with the new VDR-enabled machines without compromising the plan quality or treatment efficiency. With a prospective optimization approach using variable angular spacing, CDR delivery times can be further minimized while maintaining the high delivery efficiency of single-arc IMAT treatment.

In Vivo Imaging Reveals Significant Tumor Vascular Dysfunction and Increased Tumor Hypoxia-Inducible Factor-1α Expression Induced by High Single-Dose Irradiation in a Pancreatic Tumor Model

Energy Technology Data Exchange (ETDEWEB)

Maeda, Azusa [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Chen, Yonghong; Bu, Jiachuan; Mujcic, Hilda [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Wouters, Bradly G. [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); DaCosta, Ralph S., E-mail: rdacosta@uhnres.utoronto.ca [Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario (Canada); Techna Institute, University Health Network, Toronto, Ontario (Canada)

2017-01-01

Purpose: To investigate the effect of high-dose irradiation on pancreatic tumor vasculature and microenvironment using in vivo imaging techniques. Methods and Materials: A BxPC3 pancreatic tumor xenograft was established in a dorsal skinfold window chamber model and a subcutaneous hind leg model. Tumors were irradiated with a single dose of 4, 12, or 24 Gy. The dorsal skinfold window chamber model was used to assess tumor response, vascular function and permeability, platelet and leukocyte adhesion to the vascular endothelium, and tumor hypoxia for up to 14 days after 24-Gy irradiation. The hind leg model was used to monitor tumor size, hypoxia, and vascularity for up to 65 days after 24-Gy irradiation. Tumors were assessed histologically to validate in vivo observations. Results: In vivo fluorescence imaging revealed temporary vascular dysfunction in tumors irradiated with a single dose of 4 to 24 Gy, but most significantly with a single dose of 24 Gy. Vascular functional recovery was observed by 14 days after irradiation in a dose-dependent manner. Furthermore, irradiation with 24 Gy caused platelet and leukocyte adhesion to the vascular endothelium within hours to days after irradiation. Vascular permeability was significantly higher in irradiated tumors compared with nonirradiated controls 14 days after irradiation. This observation corresponded with increased expression of hypoxia-inducible factor-1α in irradiated tumors. In the hind leg model, irradiation with a single dose of 24 Gy led to tumor growth delay, followed by tumor regrowth. Conclusions: Irradiation of the BxPC3 tumors with a single dose of 24 Gy caused transient vascular dysfunction and increased expression of hypoxia-inducible factor-1α. Such biological changes may impact tumor response to high single-dose and hypofractionated irradiation, and further investigations are needed to better understand the clinical outcomes of stereotactic body radiation therapy.

Meta-analysis on the Safety and Efficacy of the Reperfusion Use of a Single High Dose of Anti-T-Lymphocyte Globulin Fresenius in Kidney Transplantation.

Science.gov (United States)

Du, X; Wang, W; Sun, Z-J; Su, L L; Zhang, X-D

2016-01-01

The aim of this study was to evaluate the effects of a single high dose of the anti-T-lymphocyte globulin Fresenius (ATG-F), given before kidney transplantation, on the prevention of acute rejection response and infections and on the survival rate of the renal graft and patient. Databases including PubMed, Embase, and the Cochrane Library were searched to identify randomized controlled trials relevant to studying the presurgical use of a single high dose of ATG-F. Five RCTs that included 346 patients were selected. The meta-analysis suggested that the application of ATG-F reduced the postsurgical acute rejection reaction incidence compared to that of the control group (relative risk = 0.50, 95% confidence interval = 0.35-0.71, P = .0001). However, the application of ATG-F exhibited no significant effect on the incidence of urinary tract infection, cytomegalovirus infection, and delayed graft function. Furthermore, the one-year patient survival rate and kidney graft survival rate were not affected. The meta-analysis suggested that the reperfusion use of a single high dose (9 mg/kg) of ATG-F could effectively reduce the incidence of postsurgical acute rejection response without affecting the occurrence of infections, the survival rates of kidney grafts and patients, or the incidence of delayed graft function. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Evaluation of the sterility of single-dose medications used in a multiple-dose fashion.

Science.gov (United States)

Martin, Elizabeth P; Mukherjee, Jean; Sharp, Claire R; Sinnott-Stutzman, Virginia B

2017-11-01

Bacterial proliferation was evaluated in single-dose medications used in a multi-dose fashion and when medications were intentionally inoculated with bacteria. Of 5 experimentally punctured medications, 1 of 75 vials (50% dextrose) became contaminated. When intentionally inoculated, hydroxyethyl starch and heparinized saline supported microbial growth. Based on these findings, it is recommended that hydroxyethyl starch and heparinized saline not be used in a multi-dose fashion.

Response of mouse tongue epithelium to single doses of bleomycin and radiation

International Nuclear Information System (INIS)

Dorr, W.; Hirler, E.; Honig, M.

1993-01-01

Both bleomycin (BLM) and local X-irradiation (25 kV) induce denudation in the tongue epithelium of the C3H-Neuherberg mouse in a dose-dependent manner. In the present study the effect of BLM alone and of combined single doses of drug and radiation were studied using the incidence of epithelial denudation as the end-point. In 'time-line' experiments, 8 mg/kg BLM were given before or after graded doses of X-rays. BLM treatment required a reduction of the radiation dose (ED 50 ) from 15 Gy to 5-7 Gy, independent of sequence or time interval. In contrast, the time course of the response was clearly dependent on the treatment interval. Latency decreased when the drug was injected less than 2 h before irradiation with minimum latency observed at 30 min. Isobologram analysis of experiments with varying combinations of X-rays and BLM demonstrated that small drug doses were relatively more effective than larger doses, suggesting an upward concavity of the BLM dose-effective curve in vivo, i.e. a 'negative shoulder' of the curve in the low dose region. In contrast to the response to X-rays alone, which has a constant latent time to ulcer of 10 days, the latency in combined treatment was clearly shortened with increasing drug dose and at high doses eventually approximated the epithelial turnover time of 5 days. The data suggest that BLM both as a single agent and in combination with X-rays reduced the probability of abortive divisions and through this effect shortened the latent time to epithelial denudation. (author)

Single-dose-response curves of murine gastrointestinal crypt stem cells

International Nuclear Information System (INIS)

Masuda, K.; Withers, H.R.; Mason, K.A.; Chen, K.Y.

1977-01-01

Dose-response curves for the reproductive capacity of crypt stem cells of murine colonic, jejunal, and gastric mucosae exposed in situ to multifractionated gamma ray exposures were analyzed and single-dose-survival curves of these cells were constructed. The following conclusions were drawn: (1) The single-dose-response curves bend downward over a dose range of approximately 200 to 1500 rad; (2) cell death seems to be due to nonrepairable damage at doses less than 250 rad for colon, and 220 rad for jejunum; (3) there are 21, 110, and 140 stem cells per crypt of gastric, colonic, and jejunal mucosa, respectively; and (4) jejunal stem cells are the most radiosensitive and gastric mucosal stem cells are the most resistant

Single-dose radiotherapy for painful bone metastases

International Nuclear Information System (INIS)

Kal, H.B.

1999-01-01

Background: External beam radiotherapy is frequently applied for palliative treatment of painful bone lesions with a variety of fractionation schemes. There is a continuous interest to administer only 1 or a few dose fractions for inducing pain relief. Methods: A review of the literature was made with the aim to determine whether a treatment can be deduced that is simple and effective. The linear-quadratic (L-Q) concept was applied to compare reported therapy schemes which each other for the iso-effect pain relief. Results: Single-dose and fractionated radiotherapy resulted in partial or complete pain relief in about 80% of the patients. Complete responses have been observed in about 43% of the patients. For patients responding to treatment, the duration of pain relief is at least 3 to 4 months with reported duration of up to 1 year or even longer. Conclusion: Based on this review of literature data concerning randomized trials a treatment with a single dose of 8 Gy is effective for inducing pain relief. (orig.) [de

Dose volume assessment of high dose rate 192IR endobronchial implants

International Nuclear Information System (INIS)

Cheng, B. Saw; Korb, Leroy J.; Pawlicki, Todd; Wu, Andrew

1996-01-01

Purpose: To study the dose distributions of high dose rate (HDR) endobronchial implants using the dose nonuniformity ratio (DNR) and three volumetric irradiation indices. Methods and Materials: Multiple implants were configured by allowing a single HDR 192 Ir source to step through a length of 6 cm along an endobronchial catheter. Dwell times were computed to deliver a dose of 5 Gy to points 1 cm away from the catheter axis. Five sets of source configurations, each with different dwell position spacings from 0.5 to 3.0 cm, were evaluated. Three-dimensional (3D) dose distributions were then generated for each source configuration. Differential and cumulative dose-volume curves were generated to quantify the degree of target volume coverage, dose nonuniformity within the target volume, and irradiation of tissues outside the target volume. Evaluation of the implants were made using the DNR and three volumetric irradiation indices. Results: The observed isodose distributions were not able to satisfy all the dose constraints. The ability to optimally satisfy the dose constraints depended on the choice of dwell position spacing and the specification of the dose constraint points. The DNR and irradiation indices suggest that small dwell position spacing does not result in a more homogeneous dose distribution for the implant. This study supports the existence of a relationship between the dwell position spacing and the distance from the catheter axis to the reference dose or dose constraint points. Better dose homogeneity for an implant can be obtained if the spacing of the dwell positions are about twice the distance from the catheter axis to the reference dose or dose constraint points

A single high dose of escitalopram increases mismatch negativity without affecting processing negativity or P300 amplitude in healthy volunteers

DEFF Research Database (Denmark)

Wienberg, M; Glenthøj, Birte Yding; Jensen, K S

2009-01-01

processing. The present study was designed to replicate and further extent the results of our initial study on the effects of a low dose of escitalopram (10 mg) on MMN, PN and P300 amplitude. In a randomised, double-blind, cross-over experiment, 20 healthy male volunteers received either a single, orally...... administered dose of 15 mg escitalopram (a highly selective serotonin reuptake inhibitor (SSRI)) or placebo, after which their PN, MMN and P300 amplitude were assessed. Similar to our initial study with 10 mg escitalopram, 15 mg escitalopram significantly increased MMN, while it did not affect P300 amplitude....... In contrast to our initial study, however, the currently higher dose of escitalopram did not increase PN. Results support the view that a broad range of increased serotonergic activity enhances MMN, while the relationship between serotonin and PN seems more complex. The current study does not support...

Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: Tumor dose inhomogeneity, conformity, and dose fall off

Energy Technology Data Exchange (ETDEWEB)

Hong, Linda X.; Garg, Madhur; Lasala, Patrick; Kim, Mimi; Mah, Dennis; Chen, Chin-Cheng; Yaparpalvi, Ravindra; Mynampati, Dinesh; Kuo, Hsiang-Chi; Guha, Chandan; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Neurosurgery, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Epidemiology and Population Health, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

2011-03-15

Purpose: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. Methods: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters {<=}20 mm: 31; between 20 and 30 mm: 21; and >30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R{sub 50}-R{sub 100} (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV{sub 50}) were calculated. Results: HI was inversely related to the beam margins around the PTV. CI had a ''V'' shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R{sub 50}-R{sub 100} and NTV{sub 50} initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group

Health-Related Quality of Life After Single-Fraction High-Dose-Rate Brachytherapy and Hypofractionated External Beam Radiotherapy for Prostate Cancer

International Nuclear Information System (INIS)

Morton, Gerard C.; Loblaw, D. Andrew; Chung, Hans; Tsang, Gail; Sankreacha, Raxa; Deabreu, Andrea; Zhang Liying; Mamedov, Alexandre; Cheung, Patrick; Batchelar, Deidre; Danjoux, Cyril; Szumacher, Ewa

2011-01-01

Purpose: To investigate the change in health-related quality of life for men after high-dose-rate brachytherapy and external beam radiotherapy for prostate cancer and the factors associated with this change. Methods and Materials: Eligible patients had clinically localized intermediate-risk prostate cancer. The patients received high-dose-rate brachytherapy as a single 15-Gy implant, followed by external beam radiotherapy to 37.5 Gy in 15 fractions. The patients were monitored prospectively for toxicity (Common Terminology Criteria for Adverse Events, version 3.0) and health-related quality of life (Expanded Prostate Cancer Index Composite [EPIC]). The proportion of patients developing a clinically significant difference in the EPIC domain score (minimally important difference of >0.5 standard deviation) was determined and correlated with the baseline clinical and dosimetric factors. The study accrued 125 patients, with a median follow-up of 24 months. Results: By 24 months, 23% had Grade 2 urinary toxicity and only 5% had Grade 2 bowel toxicity, with no Grade 3 toxicity. The proportion of patients reporting a significant decrease in EPIC urinary, bowel, sexual, and hormonal domain scores was 53%, 51%, 45%, and 40% at 12 months and 57%, 65%, 51%, and 30% at 24 months, respectively. The proportion with a >1 standard deviation decrease in the EPIC urinary, bowel, sexual, and hormonal domain scores was 38%, 36%, 24%, and 20% at 12 months and 46%, 48%, 19%, and 8% at 24 months, respectively. On multivariate analysis, the dose to 10% of the urethra was associated with a decreasing EPIC urinary domain score (p = .0089) and, less strongly (p = .0312) with a decreasing hormonal domain score. No association was found between the prostate volume, bladder dose, or high-dose volume and urinary health-related quality of life. A high baseline International Index of Erectile Function score was associated (p = .0019) with a decreasing sexual domain score. The optimal maximal dose

High-dose 8% capsaicin patch in treatment of chemotherapy-induced peripheral neuropathy: single-center experience.

Science.gov (United States)

Filipczak-Bryniarska, Iwona; Krzyzewski, Roger M; Kucharz, Jakub; Michalowska-Kaczmarczyk, Anna; Kleja, Justyna; Woron, Jarosław; Strzepek, Katarzyna; Kazior, Lucyna; Wordliczek, Jerzy; Grodzicki, Tomasz; Krzemieniecki, Krzysztof

2017-08-17

High-dose capsaicin patch is effective in treatment of neuropathic pain in HIV-associated neuropathy and diabetic neuropathy. There are no studies assessing effectiveness of high-dose capsaicin patch in treatment of chemotherapy-induced peripheral neuropathy. We sought to determine the effectiveness of treatment of pain associated with chemotherapy-induced peripheral neuropathy with high-dose capsaicin patch. Our study group consisted of 18 patients with clinically confirmed oxaliplatin-induced neuropathy. Baseline characteristic including underling disease, received cumulative dose of neurotoxic agent, neuropathic symptoms, prior treatment and initial pain level were recorded. Pain was evaluated with Numeric Rating Scale prior to treatment with high-dose capsaicin and after 1.8 day and after 8 and 12 weeks after introducing treatment. Patients were divided into two groups accordingly to the amount of neurotoxic agent that caused neuropathy (high sensitivity and low sensitivity group). Most frequent symptoms of chemotherapy-induced neuropathy were: pain (88.89%), paresthesis (100%), sock and gloves sensation (100%) and hypoesthesis (100%). Initial pain level was 7.45 ± 1.14. Mean cumulative dose of oxaliplatin after which patients developed symptoms was 648.07 mg/m 2 . Mean pain level after 12 weeks of treatment was 0.20 ± 0.41. When examined according to high and low sensitivity to neurotoxic agent patients with low sensitivity had higher pain reduction, especially after 8 days after introducing treatment (69.55 ± 12.09 vs. 49.40 ± 20.34%; p = 0.02) and after 12 weeks (96.96 ± 5.56 vs. 83.93 ± 18.59%; p = 0.04). High-dose capsaicin patch is an effective treatment for pain associated with chemotherapy-induced neuropathy in patients treated with oxaliplatin. Patients with lower sensitivity to neurotoxic agents have better response to treatment and pain reduction.

Optimizing a single fixed dose of Iodine-131 in Graves' Disease (An Experience)

International Nuclear Information System (INIS)

Khan, S.H.

2007-01-01

Full text: Kashmir is a Himalayan mountain state of India enclosed by high snow capped ridges of Pir Panjal Mountains at an average height of 4000-5000 meters above the sea level. For most of the 4 million inhabitants in this land locked valley, agriculture horticulture and handcrafts are the main source of income. Due to long and severe winters the terraced farming on the mountain slopes yield just a single crop of rice which is barely sufficient to meet the local needs of this staple diet. People are relatively poor with low annual per capita income. Goiter is endemic in the Valley of Kashmir. In a published report the overall prevalence of goiter among the school going children in Kashmir between the ages of 5 years is 45.2% (+ SEM) with urinary iodine excretion of 49 + 3.55 μg per gram of creatinine. The extremely shy people of Kashmir are casual towards the aesthetic aspects of their goiters but nevertheless seek medical advice when associated with physical symptoms. In a published study of 203 patients of thyrotoxicosis from Kashmir, Graves' disease was the commonest cause, accounting for 63% of patients. One hundred and twentyone patients of Graves' disease were prospectively studied for their response to a single fixed dose of I-131. Patients were randomly treated with two different fixed doses of I- 131. Sixty four patients belonging to Group-I received a fixed dose of 185 MBq (Low Dose) and 57 patients belonging to Group -2 received 370 MBq (High Dose) of I- 131. Following therapy all patients were evaluated at 3 months. Patients with normal or reduced thyroid hormone levels were termed as responders and those with persistently elevated levels of thyroid hormone were termed as non responders. The response rates among the two groups were analyzed for their statistical significance. Patients treated with the high fixed dose of 370 MBq revealed good response to therapy achieving a rate of 91.22%, while the response rate in the group of patients treated with

Single point estimation of phenytoin dosing: a reappraisal.

Science.gov (United States)

Koup, J R; Gibaldi, M; Godolphin, W

1981-11-01

A previously proposed method for estimation of phenytoin dosing requirement using a single serum sample obtained 24 hours after intravenous loading dose (18 mg/Kg) has been re-evaluated. Using more realistic values for the volume of distribution of phenytoin (0.4 to 1.2 L/Kg), simulations indicate that the proposed method will fail to consistently predict dosage requirements. Additional simulations indicate that two samples obtained during the 24 hour interval following the iv loading dose could be used to more reliably predict phenytoin dose requirement. Because of the nonlinear relationship which exists between phenytoin dose administration rate (RO) and the mean steady state serum concentration (CSS), small errors in prediction of the required RO result in much larger errors in CSS.

Single and Multiple Ascending-dose Studies of Oral Delafloxacin: Effects of Food, Sex, and Age.

Science.gov (United States)

Hoover, Randall; Hunt, Thomas; Benedict, Michael; Paulson, Susan K; Lawrence, Laura; Cammarata, Sue; Sun, Eugene

2016-01-01

The objective of this report is describe the results of 2 studies that examined the pharmacokinetic parameters, safety profile, and tolerability of single and multiple ascending doses of oral delafloxacin and the effects of food, sex, and age on oral delafloxacin pharmacokinetic parameters, safety profile, and tolerability. The first study contained 3 parts and used unformulated delafloxacin in a capsule. Part 1 was a randomized, double-blind, placebo-controlled, single (50, 100, 200, 400, 800, 1200, and 1600 mg) ascending-dose study of oral delafloxacin in healthy men. Part 2 was a single-dose crossover study in which 20 men received 250 mg delafloxacin with or without food. Part 2 also included a parallel group, double-blind, placebo-controlled study in 16 women and 16 elderly men and women who were randomized (3:1) to receive 250 mg delafloxacin or placebo. Part 3 was a randomized, double-blind, placebo-controlled, multiple (100, 200, 400, 800, 1200 mg once daily for 5 days) ascending-dose study of oral delafloxacin in healthy men. The second study was a single-dose, randomized, 3-period crossover study in which participants received 900 mg delafloxacin (2 × 450-mg tablets) under fasted conditions, with a high-fat meal, or fasted with a high-fat meal 2 hours after dosing. Serial blood samples were collected, and plasma pharmacokinetic parameters of delafloxacin were determined. Delafloxacin Cmax and AUC0-∞ increased with increasing oral dose over the dose range of 50 to 1600 mg. The increases in delafloxacin AUC0-∞ were dose proportional at doses of ≥200 mg. Steady state was reached by day 3 of dosing with minimal accumulation of delafloxacin. The Cmax of delafloxacin was decreased slightly in the presence of food. No sex difference in delafloxacin pharmacokinetic parameters was observed. In the elderly men and women, mean delafloxacin Cmax and AUC0-∞ were 35% higher than observed for young adults, which could be partially explained by a decrease in

Irradiation of single cells with individual high-LET particles

International Nuclear Information System (INIS)

Nelson, J.M.; Braby, L.A.

1993-01-01

The dose-limiting normal tissue of concern when irradiating head and neck lesions is often the vascular endothelium within the treatment field. Consequently, the response of capillary endothelial cells exposed to moderate doses of high LET particles is essential for establishing exposure limits for neutron-capture therapy. In an effort to characterize the high-LET radiation biology of cultured endothelial cells, the authors are attempting to measure cellular response to single particles. The single-particle irradiation apparatus, described below, allows them to expose individual cells to known numbers of high-LET particles and follow these cells for extended periods, in order to assess the impact of individual particles on cell growth kinetics. Preliminary cell irradiation experiments have revealed complications related to the smooth and efficient operation of the equipment; these are being resolved. Therefore, the following paragraphs deal primarily with the manner by which high LET particles deposit energy, the requirements for single-cell irradiation, construction and assembly of such apparatus, and testing of experimental procedures, rather than with the radiation biology of endothelial cells

High dose calibrations at the Pacific Northwest Laboratory

International Nuclear Information System (INIS)

McDonald, J.C.; Fox, R.A.

1988-10-01

The need is increasing for both high radiation exposures and calibration measurements that provide traceability of such exposures to national standards. The applications of high exposures include: electronic component damage studies, sterilization of medical products and food irradiation. Accurate high exposure measurements are difficult to obtain and cannot, in general, be carried out with a single dose measurement system or technique because of the wide range of doses and the variety of materials involved. This paper describes the dosimetric measurement and calibration techniques used at the Pacific Northwest Laboratory (PNL) that make use of radiochromic dye films, thermoluminescent dosimeters (TLDs), ionization chambers, and calorimetric dosimeters. The methods used to demonstrate the consistency of PNL calibrations with national standards will also be discussed. 4 refs

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

Science.gov (United States)

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Efficacy of various single-dose regimens of ceftriaxone in ...

African Journals Online (AJOL)

The therapeutic efficacy of single intramuscular doses of ceftriaxone (Rocephin; Roche) (62,S, 125 and 250 mg), administered without probenecid, was evaluated in 167 adult males with uncomplicated acute gonococcal urethritis. Cure rates of 100% were achieved at 62,5 mg and 250 mg. In the 125 mg dose group, ...

Single dose toxicity and biodistribution studies of [{sup 18}F] fluorocholine

Energy Technology Data Exchange (ETDEWEB)

Campos, Danielle C.; Santos, Priscilla F., E-mail: dcc@cdtn.br [Universidade Federal de Minas Gereais (INCT-MM/UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina. Instituto Nacional de Ciencia e Tecnologia de Medicina Molecular; Silveira, Marina B.; Ferreira, Soraya Z.; Malamut, Carlos; Silva, Juliana B. da, E-mail: radiofarmacoscdtn@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos; Souza, Cristina M.; Campos, Liliane C.; Ferreira, Enio; Araujo, Marina R.; Cassali, Geovanni D., E-mail: cassalig@icb.ufmg.br [Universidade Federal de Minas Gerais (LPC/UFMG), Belo Horizonte, MG (Brazil). Lab. de Patologia Comparada

2013-07-01

[{sup 18}F]Fluorocholine ({sup 18}FCH) is a valuable tool for non-invasive diagnosis using positron emission tomography (PET). This radiotracer has been proven to be highly effective in detecting recurrences and staging prostate cancer, diagnoses brain, breast, and esophageal tumors and also hepatocellular carcinoma. The higher uptake of fluorocholine by malignant tumors results from increased choline kinase activity due to accelerated cell multiplication and membrane formation. According to the Brazilian Health Surveillance Agency (ANVISA), radiopharmaceuticals have to be registered before commercialization. The aim of this work was to evaluate single dose toxicity and biodistribution of {sup 18}FCH in mice, since preclinical safety studies are required for register. Experimental procedures were approved by the Ethics Committee on Animal Use (CEUA-IPEN/SP). Single dose toxicity and biodistribution studies were conducted in Swiss mice. No signs of toxicity were observed during clinical trial. No changes in the parameters which were examined, such as: body weight, food consumption, clinical pathology parameters or lesions microscopic were noted. Biodistribution results indicated high physiological tracer uptake in kidney, liver and heart 30 min after injection. Lower activities were recorded in other organs/tissues: pancreas, intestine, spleen, bone, bladder, muscle, brain and blood. Initial preclinical investigations showed no toxic effects of {sup 18}FCH at investigated doses and a biodistribution profile very similar to other reports in literature. This information is essential to support future human trials. (author)

SINGLE-DOSE VERSUS 3-DAY PROPHYLAXIS WITH CIPROFLOXACIN IN TRANSURETHRAL SURGERY - A CLINICAL-TRIAL

NARCIS (Netherlands)

BIJL, W; JANKNEGT, RA

1993-01-01

in 235 patients who underwent transurethral surgery, perioperative oral ciprofloxacin prophylaxis was given as a single dose 500 mg versus a 3-day regimen. Out of 180 evaluable patients, 84 received a single dose and 96 received a 3-day course. In the single dose prophylaxis group there were 5

Single event effects and total ionizing dose effects of typical VDMOSFET devices

International Nuclear Information System (INIS)

Lou Jianshe; Cai Nan; Liu Jiaxin; Wu Qinzhi; Wang Jia

2012-01-01

In this work, single event effects and total ionizing dose effects of typical VDMOSFET irradiated by 60 Co γ-rays and 252 Cf source were studied. The single event burnout and single event gate rupture (SEB/SEGR) effects were investigated, and the relationship between drain-source breakdown voltage and ionizing dose was obtained. The results showed that the VDMOSFET devices were sensitive to SEB and SEGR, and measures to improve their resistance to SEB and SEGR should be considered seriously for their space applications. The drain-source breakdown voltage was sensitive to total ionizing dose effects as the threshold voltage. In assessing the devices' resistance to the total ionizing dose effects, both the threshold voltage and the drain-source breakdown voltage should be taken into account. (authors)

Study of the response reduction of LiF:Mg, Ti dosimeter for high dose dosimetry

Energy Technology Data Exchange (ETDEWEB)

Torkzadeh, Falamarz [Nuclear Sciences and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Applications Research School; AEOI, Tehran (Iran, Islamic Republic of); Faripour, Heidar [Nuclear Sciences and Technology Research Institute, Tehran (Iran, Islamic Republic of). Laser and Optics Research School; AEOI, Tehran (Iran, Islamic Republic of); Mardashti, Forough; Manouchehri, Farhad [Nuclear Sciences and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Applications Research School

2017-07-15

A single crystal and 5 polycrystalline samples of LiF:Mg, Ti and their pellets were prepared and investigated so as to apply thermoluminescence high gamma dose dosimetry. Three zones of single crystal with dopant concentrations of 200 ppm of Mg and 20 ppm of Ti were also used to prepare the single crystal samples. For polycrystalline samples, dopant concentrations of 0.062 mol% Mg and Ti concentrations in the range of 0.016 and 0.046 mol% were used. All the samples were exposed to gamma doses of 1 kGy to 700 kGy and their response changes were determined by a gamma dose test of about 60 mGy. According to the results obtained, the use of response reduction by curve-fitting up to about 300 kGy can be performed reliably for high dose gamma dosimetry.

Dose rate-dependent marrow toxicity of TBI in dogs and marrow sparing effect at high dose rate by dose fractionation.

Science.gov (United States)

Storb, R; Raff, R F; Graham, T; Appelbaum, F R; Deeg, H J; Schuening, F G; Sale, G; Seidel, K

1999-01-01

We evaluated the marrow toxicity of 200 and 300 cGy total-body irradiation (TBI) delivered at 10 and 60 cGy/min, respectively, in dogs not rescued by marrow transplant. Additionally, we compared toxicities after 300 cGy fractionated TBI (100 cGy fractions) to that after single-dose TBI at 10 and 60 cGy/min. Marrow toxicities were assessed on the basis of peripheral blood cell count changes and mortality from radiation-induced pancytopenia. TBI doses studied were just below the dose at which all dogs die despite optimal support. Specifically, 18 dogs were given single doses of 200 cGy TBI, delivered at either 10 (n=13) or 60 (n=5) cGy/min. Thirty-one dogs received 300 cGy TBI at 10 cGy/min, delivered as either single doses (n=21) or three fractions of 100 cGy each (n=10). Seventeen dogs were given 300 cGy TBI at 60 cGy/min, administered either as single doses (n=5) or three fractions of 100 cGy each (n=10). Within the limitations of the experimental design, three conclusions were drawn: 1) with 200 and 300 cGy single-dose TBI, an increase of dose rate from 10 to 60 cGy/min, respectively, caused significant increases in marrow toxicity; 2) at 60 cGy/min, dose fractionation resulted in a significant decrease in marrow toxicities, whereas such a protective effect was not seen at 10 cGy/min; and 3) with fractionated TBI, no significant differences in marrow toxicity were seen between dogs irradiated at 60 and 10 cGy/min. The reduced effectiveness of TBI when a dose of 300 cGy was divided into three fractions of 100 cGy or when dose rate was reduced from 60 cGy/min to 10 cGy/min was consistent with models of radiation toxicity that allow for repair of sublethal injury in DNA.

Safety aspects of preoperative high-dose glucocorticoid in primary total knee replacement

DEFF Research Database (Denmark)

Jørgensen, C C; Pitter, F T; Kehlet, H

2017-01-01

Background: Preoperative single high-dose glucocorticoid may have early outcome benefits in total hip arthroplasty (THA) and knee arthroplasty (TKA), but long-term safety aspects have not been evaluated. Methods: From October 2013, the departments reporting to the prospective Lundbeck Foundation....... Conclusions: In this detailed prospective cohort study, preoperative high-dose glucocorticoid administration was not associated with LOS >4 days, readmissions or infectious complications in TKA patients without contraindications....

Pharmacokinetics of voriconazole after oral administration of single and multiple doses in Hispaniolan Amazon parrots (Amazona ventralis).

Science.gov (United States)

Sanchez-Migallon Guzman, David; Flammer, Keven; Papich, Mark G; Grooters, Amy M; Shaw, Shannon; Applegate, Jeff; Tully, Thomas N

2010-04-01

To determine the pharmacokinetics and safety of voriconazole administered orally in single and multiple doses in Hispaniolan Amazon parrots (Amazona ventralis). 15 clinically normal adult Hispaniolan Amazon parrots. Single doses of voriconazole (12 or 24 mg/kg) were administered orally to 15 and 12 birds, respectively; plasma voriconazole concentrations were determined at intervals via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) or water was administered orally to 6 and 4 birds, respectively, every 8 hours for 11 days (beginning day 0); trough plasma voriconazole concentrations were evaluated on 3 days. Birds were monitored daily, and clinicopathologic variables were evaluated before and after the trial. Voriconazole elimination half-life was short (0.70 to 1.25 hours). In the single-dose experiments, higher drug doses yielded proportional increases in the maximum plasma voriconazole concentration (C(max)) and area under the curve (AUC). In the multiple-dose trial, C(max), AUC, and plasma concentrations at 2 and 4 hours were decreased on day 10, compared with day 0 values; however, there was relatively little change in terminal half-life. With the exception of 1 voriconazole-treated parrot that developed polyuria, adverse effects were not evident. In Hispaniolan Amazon parrots, oral administration of voriconazole was associated with proportional kinetics following administration of single doses and a decrease in plasma concentration following administration of multiple doses. Oral administration of 18 mg of voriconazole/kg every 8 hours would require adjustment to maintain therapeutic concentrations during long-term treatment. Safety and efficacy of voriconazole treatment in this species require further investigation.

Fixed-dose combinations of drugs versus single-drug formulations for treating pulmonary tuberculosis

Science.gov (United States)

Gallardo, Carmen R; Rigau Comas, David; Valderrama Rodríguez, Angélica; Roqué i Figuls, Marta; Parker, Lucy Anne; Caylà, Joan; Bonfill Cosp, Xavier

2016-01-01

meta-analysis. We assessed the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Main results We included 13 randomized controlled trials (RCTs) in the review, which enrolled 5824 participants. Trials were published between 1987 and 2015 and included participants in treatment with newly diagnosed pulmonary TB in countries with high TB prevalence. Only two trials reported the HIV status of included participants. Overall there is little or no difference detected between FDCs and single-drug formulations for most outcomes reported. We did not detect a difference in treatment failure between FDCs compared with single-drug formulations (RR 1.28, 95% CI 0.82 to 2.00; 3606 participants, seven trials, moderate quality evidence). Relapse may be more frequent in people treated with FDCs compared to single-drug formulations, although the confidence interval (CI) includes no difference (RR 1.28, 95% CI 1.00 to 1.64; 3621 participants, 10 trials, low quality evidence). We did not detect any difference in death between fixed-dose and single-drug formulation groups (RR 0.96, 95% CI 0.67 to 1.39; 4800 participants, 11 trials, moderate quality evidence). When we compared FDCs with single-drug formulations we found little or no difference for sputum smear or culture conversion at the end of treatment (RR 0.99, 95% CI 0.96 to 1.02; 2319 participants, seven trials, high quality evidence), for serious adverse events (RR 1.45, 95% CI 0.90 to 2.33; 3388 participants, six trials, moderate quality evidence), and for adverse events that led to discontinuation of therapy (RR 0.96, 95% CI 0.56 to 1.66; 5530 participants, 13 trials, low quality evidence). We conducted a sensitivity analysis excluding studies at high risk of bias and this did not alter the review findings. Authors' conclusions Fixed-dose combinations and single-drug formulations probably have similar effects for treating people with newly diagnosed pulmonary TB. PLAIN

Dose optimisation in single plane interstitial brachytherapy

DEFF Research Database (Denmark)

Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette Benedicte

2006-01-01

patients,       treated for recurrent rectal and cervical cancer, flexible catheters were       sutured intra-operatively to the tumour bed in areas with compromised       surgical margin. Both non-optimised, geometrically and graphically       optimised CT -based dose plans were made. The overdose index...... on the       regularity of the implant, such that the benefit of optimisation was       larger for irregular implants. OI and HI correlated strongly with target       volume limiting the usability of these parameters for comparison of dose       plans between patients. CONCLUSIONS: Dwell time optimisation significantly......BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

Dual-sided reading versus single-sided reading: comparison of image quality and radiation dose between the two computed radiography system

International Nuclear Information System (INIS)

Song Shaojuan; Qi Hengtao; Zhao Yongxia; Jiao Fanglian

2007-01-01

Objective: To assess and compare the difference in image quality and exposure dose between single-sided reading image plate (IP) and dual-sided reading IP. Methods: A contrast-detail phantom CDRAD 2.0 was exposed by single-sided and dual-sided reading IP with different mAs sets. The entrance surface doses were recorded for all images. Images were then presented to two radiologists on a high resolution monitor of diagnosis workstation. The image quality figure (IQF) was measured for each image. Statistical analysis was performed using Spearman's correlation test and Wilcoxon signed-rank test to compare the difference in image quality and exposure dose between single-sided IP and dual-sided reading IP. Results: With different tube current dosage of 5.6, 12.0, 20.0, 25.0, and 40.0 mAs, IQF values of single-sided reading IP were 47.95, 37.68, 34.31, 28.61, and 24.65, respectively, while those of dual- sided reading IP were 38.83, 29.81, 29.65, 25.16, and 21.43, respectively. The IQF difference between them showed statistical significance (P<0.05). Conclusion: Image quality of dual-sided reading IP has been proved to be far superior to that of single-sided reading IP, in particular for low contrast detail. The image quality of single-sided reading IP is similar to that of dual-sided reading IP only at high dose levels. The clinical application of dual-sided reading IP will reduce the exposure dose by about 25% compared with single-sided reading IP. (authors)

Effective dose to staff from interventional procedures: Estimations from single and double dosimetry

International Nuclear Information System (INIS)

Kuipers, G.; Velders, X. L.

2009-01-01

The exposure of 11 physicians performing interventional procedures was measured by means of two personal dosemeters. One personal dosemeter was worn outside the lead apron and an additional under the lead apron. The study was set up in order to determine the added value of a dosemeter worn under the lead apron. With the doses measured, the effective doses of the physicians were estimated using an algorithm for single dosimetry and two algorithms for double dosimetry. The effective doses calculated with the single dosimetry algorithm ranged from 0.11 to 0.85 mSv in 4 weeks. With the double dosimetry algorithms, the effective doses ranged from 0.02 mSv to 0.47 mSv. The statistical analysis revealed no significant differences in the accuracy of the effective doses calculated with single or double dosimetry algorithms. It was concluded that the effective dose cannot be considered a more accurate estimate when two dosemeters are used instead of one. (authors)

Single dose oral ketoprofen or dexketoprofen for acute postoperative pain in adults.

Science.gov (United States)

Gaskell, Helen; Derry, Sheena; Wiffen, Philip J; Moore, R Andrew

2017-05-25

% pain relief over six hours with the usual dexketoprofen oral dose of 20 mg or 25 mg was 52%, compared to 27% with placebo, giving an NNT of 4.1 (95% CI 3.3 to 5.2) (RR 2.0, 95% CI 1.6 to 2.2; 1177 participants; 8 studies; high quality evidence). Efficacy was significantly better in dental studies (NNT 2.7) than other surgery (NNT 5.7). The proportion of participants using rescue medication within six hours was lower with dexketoprofen (47%) than placebo (69%), giving an NNTp of 4.7 (95% CI 3.3 to 8.0); 445 participants; 5 studies; high quality evidence). Median time to remedication estimates were poorly reported. Reports of any adverse event were similar with dexketoprofen (14%) and placebo (10%) (RR 1.4, 95% CI 0.89 to 2.2; 536 participants, 6 studies; high quality evidence). No study reported any serious adverse events (very low quality evidence). Ketoprofen at doses of 25 mg to 100 mg is an effective analgesic in moderate to severe acute postoperative pain with an NNT for at least 50% pain relief of 2.9 with a 50 mg dose. This is similar to that of commonly used NSAIDs such as ibuprofen (NNT 2.5 for 400 mg dose) and diclofenac (NNT 2.7 for 50 mg dose). Dexketoprofen is also effective with an NNT of 4.1 in the dose range 10 mg to 25 mg. Differential efficacy between dental surgery and other types of surgery seen for both drugs is unusual. Both drugs were well tolerated in single doses.

Failure Rate of Single Dose Methotrexate in Managment of Ectopic Pregnancy

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Feras Sendy

2015-01-01

Full Text Available Background. One of the treatment modalities for ectopic pregnancy is methotrexate. The purpose of this study is to identify the failure rate of methotrexate in treating patients with ectopic pregnancy as well as the risk factors leading to treatment failure. Methods. A retrospective chart review of 225 patients who received methotrexate as a primary management option for ectopic pregnancy. Failure of single dose of methotrexate was defined as drop of BHCG level less than or equal to 14% in the seventh day after administration of methotrexate. Results. 225 patients had methotrexate. Most of the patients (151 (67% received methotrexate based on the following formula: f 50 mg X body surface area. Single dose of methotrexate was successful in 72% (162/225 of the patients. 28% (63/225 were labeled as failure of single dose of methotrexate because of suboptimal drop in BhCG. 63% (40/63 of failure received a second dose of methotrexate, and 37% (23/63 underwent surgical treatment. Among patient who received initial dose of methotrexate, 71% had moderate or severe pain, and 58% had ectopic mass size of more than 4 cm on ultrasound. Conclusion. Liberal use of medical treatment of ectopic pregnancy results in 71% success rate.

Failure rate of single dose methotrexate in managment of ectopic pregnancy.

Science.gov (United States)

Sendy, Feras; AlShehri, Eman; AlAjmi, Amani; Bamanie, Elham; Appani, Surekha; Shams, Taghreed

2015-01-01

Background. One of the treatment modalities for ectopic pregnancy is methotrexate. The purpose of this study is to identify the failure rate of methotrexate in treating patients with ectopic pregnancy as well as the risk factors leading to treatment failure. Methods. A retrospective chart review of 225 patients who received methotrexate as a primary management option for ectopic pregnancy. Failure of single dose of methotrexate was defined as drop of BHCG level less than or equal to 14% in the seventh day after administration of methotrexate. Results. 225 patients had methotrexate. Most of the patients (151 (67%)) received methotrexate based on the following formula: f 50 mg X body surface area. Single dose of methotrexate was successful in 72% (162/225) of the patients. 28% (63/225) were labeled as failure of single dose of methotrexate because of suboptimal drop in BhCG. 63% (40/63) of failure received a second dose of methotrexate, and 37% (23/63) underwent surgical treatment. Among patient who received initial dose of methotrexate, 71% had moderate or severe pain, and 58% had ectopic mass size of more than 4 cm on ultrasound. Conclusion. Liberal use of medical treatment of ectopic pregnancy results in 71% success rate.

Protect Patients by Using Single- and Multi-Dose Vials Correctly

Centers for Disease Control (CDC) Podcasts

2014-07-10

CDC’s One & Only Campaign urges healthcare providers to recognize the differences between single-dose and multi-dose vials, and to understand appropriate use of each container type.  Created: 7/10/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/10/2014.

Multifocal Electroretinography after High Dose Chloroquine Therapy for Malaria

Directory of Open Access Journals (Sweden)

Aline Correa de Carvalho

2013-01-01

Full Text Available Purpose: To investigate changes in multifocal electroretinography (mfERG parameters associated with high dose chloroquine therapy for treatment of malaria in the Amazonia region of Brazil. Methods: Forty-eight subjects who had received chloroquine treatment for single or multiple malaria infections with a cumulative dose ranging from 1,050 to 27,000mg were included. The control group consisted of 37 healthy aged-matched subjects. Data was collected on amplitude and implicit time of the N1, P1 and N2 waves in the central macular hexagon (R1 and in five concentric rings at different retinal eccentricities (R2-R6. Results: No significant difference was observed in any mfERG parameter between chloroquine treated patients and control subjects. A comparison with previous data obtained from patients with rheumatologic disorders in the same region of Brazil who had received larger cumulative doses of chloroquine and had displayed mfERG changes, indicated that retinal toxicity seems to be dependent on cumulative dose. Conclusion: Lack of mfERG changes in the current study suggests that intensive high dose chloroquine therapy for treatment of malaria is not associated with retinal toxicity.

High-dose total-body irradiation and autologous marrow reconstitution in dogs: dose-rate-related acute toxicity and fractionation-dependent long-term survival

International Nuclear Information System (INIS)

Deeg, H.J.; Storb, R.; Weiden, P.L.; Schumacher, D.; Shulman, H.; Graham, T.; Thomas, E.D.

1981-01-01

Beagle dogs treated by total-body irradiation (TBI) were given autologous marrow grafts in order to avoid death from marrow toxicity. Acute and delayed non-marrow toxicities of high single-dose (27 dogs) and fractionated TBI (20 dogs) delivered at 0.05 or 0.1 Gy/min were compared. Fractionated TBI was given in increments of 2 Gy every 6 hr for three increments per day. Acute toxicity and early mortality (<1 month) at identical total irradiation doses were comparable for dogs given fractionated or single-dose TBI. With single-dose TBI, 14, 16, and 18 Gy, respectively, given at 0.05 Gy/min, 0/5, 5/5, and 2/2 dogs died from acute toxicity; with 10, 12, and 14 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 5/5 dogs died acutely. With fractionated TBI, 14 and 16 Gy, respectively, given at 0.1 Gy/min, 1/5, 4/5, and 2/2 dogs died auctely. Early deaths were due to radiation enteritis with or without associated septicemia (29 dogs; less than or equal to Day 10). Three dogs given 10 Gy of TBI at 0.1 Gy/min died from bacterial pneumonia; one (Day 18) had been given fractionated and two (Days 14, 22) single-dose TBI. Fifteen dogs survived beyond 1 month; eight of these had single-dose TBI (10-14 Gy) and all died within 7 months of irradiation from a syndrome consisting of hepatic damage, pancreatic fibrosis, malnutrition, wasting, and anemia. Seven of the 15 had fractionated TBI, and only one (14 Gy) died on Day 33 from hepatic failure, whereas 6 (10-14 Gy) are alive and well 250 to 500 days after irradiation. In conclusion, fractionated TBI did not offer advantages over single-dose TBI with regard to acute toxicity and early mortality; rather, these were dependent upon the total dose of TBI. The total acutely tolerated dose was dependent upon the exposure rate; however, only dogs given fractionated TBI became healthy long-term survivors

A single 2 g oral dose of extended-release azithromycin for treatment of gonococcal urethritis.

Science.gov (United States)

Yasuda, Mitsuru; Ito, Shin; Kido, Akira; Hamano, Kiminari; Uchijima, Yutaka; Uwatoko, Noriyasu; Kusuyama, Hiroyuki; Watanabe, Akiko; Miyamura, Ryuzou; Miyata, Kazutoyo; Deguchi, Takashi

2014-11-01

We treated gonococcal urethritis in men with a single 2 g dose of azithromycin extended-release formulation (azithromycin-SR) to determine its microbiological outcomes and tolerability. We enrolled 189 Japanese men with gonococcal urethritis between April 2009 and December 2013. The patients were given a single 2 g dose of azithromycin-SR. Microbiological efficacy was evaluated by the results of the post-treatment molecular testing of Neisseria gonorrhoeae. MIC testing was performed only for pretreatment isolates of N. gonorrhoeae collected from the patients. We evaluated 130 patients for microbiological outcomes. Of these patients, 122 (93.8%) were judged to be microbiologically cured on the basis of negative test results. All isolates for which the azithromycin MICs were ≤0.25 mg/L were eradicated, whereas 5 of 12 isolates for which the MICs were 1 mg/L persisted after the treatment. Forty-six adverse events occurred in 41 patients. However, all adverse events were classified as mild. The eradication rate of N. gonorrhoeae was 93.8% in men with gonococcal urethritis treated with a single 2 g dose of azithromycin-SR. The breakpoint MIC of a 2 g dose of azithromycin-SR for gonococcal urethritis associated with clinical treatment failures appeared to be 1 mg/L. With regard to side effects of higher doses of azithromycin, the 2 g dose of azithromycin-SR appeared to improve tolerability. However, the widespread use of a high-dose regimen of azithromycin might lead to the development of further resistance to azithromycin. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Biological dose estimation and comet analysis of the victims in a high dose 60Co radiation accident

International Nuclear Information System (INIS)

Chen Ying; Liu Xiulin; Luo Yisheng; Li You; Yao Bo

2007-01-01

Objective: To explore the methods of chromosome preparation in human peripheral blood and bone marrow after very high dose exposure and fit the dose-response curve of dicentrics and tings in the range of high doses over 6 Gy for estimating biological dose and detecting DNA damage in the victims of '10.21' accident. Methods: The samples of peripheral blood and bone marrow in 2 victims were collected to prepare chromosome mataphases and dicentrics (multicentrics) + rings were counted. The dose-response curve and equation of human blood irradiated between 6-22 Gy in vitro were established and applied to assess biological dose of 2 victims. In addition, their DNA damages were tested by alkaline single cell gel electrophoresis. Results: The dicentric + ring numbers of 4.47 per cell in victims B's peripheral blood lymphocytes and 9.15 per cell in victim A's bone marrow who had no mitosis in peripheral blood cell. The whole body average doses of victims B and A estimated by 6-22 Gy equation arrived at 9.4 Gy and 19.5 Gy, respectively. The serious DNA damages were expressed by small head and large tail comet figures. Conclusions: The biological doses of 2 victims estimated by 6-22 Gy dose-response curve have reached the levels of extreme grave bone marrow and intestinal ARS, respectively. (authors)

Biological effective doses in the intracavitary high dose rate brachytherapy of cervical cancer

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Y. Sobita Devi

2011-12-01

Full Text Available Purpose: The aim of this study is to evaluate the decrease of biological equivalent dose and its correlation withlocal/loco-regional control of tumour in the treatment of cervical cancer when the strength of the Ir-192 high dose rate(HDR brachytherapy (BT source is reduced to single, double and triple half life in relation to original strength of10 Ci (~ 4.081 cGy x m2 x h–1. Material and methods: A retrospective study was carried out on 52 cervical cancer patients with stage II and IIItreated with fractionated HDR-BT following external beam radiation therapy (EBRT. International Commission onRadiation Units and Measurement (ICRU points were defined according to ICRU Report 38, using two orthogonal radiographimages taken by Simulator (Simulix HQ. Biologically effective dose (BED was calculated at point A for diffe -rent Ir-192 source strength and its possible correlation with local/loco-regional tumour control was discussed. Result: The increase of treatment time per fraction of dose due to the fall of dose rate especially in HDR-BT of cervicalcancer results in reduction in BED of 2.59%, 7.02% and 13.68% with single, double and triple half life reduction ofsource strength, respectively. The probabilities of disease recurrence (local/loco-regional within 26 months are expectedas 0.12, 0.12, 0.16, 0.39 and 0.80 for source strength of 4.081, 2.041, 1.020, 0.510 and 0.347 cGy x m2 x h–1, respectively.The percentages of dose increase required to maintain the same BED with respect to initial BED were estimated as1.71, 5.00, 11.00 and 15.86 for the dose rate of 24.7, 12.4, 6.2 and 4.2 Gy/hr at point A, respectively. Conclusions: This retrospective study of cervical cancer patients treated with HDR-BT at different Ir-192 sourcestrength shows reduction in disease free survival according to the increase in treatment time duration per fraction.The probable result could be associated with the decrease of biological equivalent dose to point A. Clinical

Pharmacokinetics of diclofenac in pigs after intramuscular administration of a single dose

OpenAIRE

Pejčić Zorica; Pokrajac Milena; Jezdimirović Milanka

2006-01-01

The pharmacokinetics of diclofenac was studied in 10 clinically normal male Yorkshire pigs, following intramuscular (i.m) administration of a single dose of diclofenac-sodium (2.5 mg/kg body weight). Diclofenac serum concentrations were determined by high pressure- liquid-chromatography (HPLC), with UV detection (226 nm). Following i.m. administration all individual diclofenac serum levels best fitted the one-compartment open model for extravascular administration. The maximal diclofenac seru...

Impact of multiple-dose versus single-dose inhaler devices on COPD patients’ persistence with long-acting β2-agonists: a dispensing database analysis

Science.gov (United States)

van Boven, Job FM; van Raaij, Joost J; van der Galiën, Ruben; Postma, Maarten J; van der Molen, Thys; Dekhuijzen, PN Richard; Vegter, Stefan

2014-01-01

Background: With a growing availability of different devices and types of medication, additional evidence is required to assist clinicians in prescribing the optimal medication in relation to chronic obstructive pulmonary disease (COPD) patients’ persistence with long-acting β2-agonists (LABAs). Aims: To assess the impact of the type of inhaler device (multiple-dose versus single-dose inhalers) on 1-year persistence and switching patterns with LABAs. Methods: A retrospective observational cohort study was performed comparing a cohort of patients initiating multiple-dose inhalers and a cohort initiating single-dose inhalers. The study population consisted of long-acting bronchodilator naive COPD patients, initiating inhalation therapy with mono-LABAs (formoterol, indacaterol or salmeterol). Analyses were performed using pharmacy dispensing data from 1994 to 2012, obtained from the IADB.nl database. Study outcomes were 1-year persistence and switching patterns. Results were adjusted for initial prescriber, initial medication, dosing regimen and relevant comorbidities. Results: In all, 575 patients initiating LABAs were included in the final study cohort. Among them, 475 (83%) initiated a multiple-dose inhaler and 100 (17%) a single-dose inhaler. Further, 269 (47%) initiated formoterol, 9 (2%) indacaterol and 297 (52%) salmeterol. There was no significant difference in persistence between users of multiple-dose or single-dose inhalers (hazard ratio: 0.98, 95% confidence interval: 0.76–1.26, P=0.99). Over 80% re-started or switched medication. Conclusions: There seems no impact of inhaler device (multiple-dose versus single-dose inhalers) on COPD patients’ persistence with LABAs. Over 80% of patients who initially seemed to discontinue LABAs, re-started their initial medication or switched inhalers or medication within 1 year. PMID:25274453

Gamma dosimetry of high doses

International Nuclear Information System (INIS)

Martinez C, T.; Galvan G, A.; Canizal, G.

1991-01-01

The gamma dosimetry of high doses is problematic in almost all the classic dosemeters either based on the thermoluminescence, electric, chemical properties, etc., because they are saturated to very high dose and they are no longer useful. This work carries out an investigation in the interval of high doses. The solid system of heptahydrate ferrous sulfate, can be used as solid dosemeter of routine for high doses of radiation. The proposed method is simple, cheap and it doesn't require sophisticated spectrophotometers or spectrometers but expensive and not common in some laboratories

Single-dose volume regulation algorithm for a gas-compensated intrathecal infusion pump.

Science.gov (United States)

Nam, Kyoung Won; Kim, Kwang Gi; Sung, Mun Hyun; Choi, Seong Wook; Kim, Dae Hyun; Jo, Yung Ho

2011-01-01

The internal pressures of medication reservoirs of gas-compensated intrathecal medication infusion pumps decrease when medication is discharged, and these discharge-induced pressure drops can decrease the volume of medication discharged. To prevent these reductions, the volumes discharged must be adjusted to maintain the required dosage levels. In this study, the authors developed an automatic control algorithm for an intrathecal infusion pump developed by the Korean National Cancer Center that regulates single-dose volumes. The proposed algorithm estimates the amount of medication remaining and adjusts control parameters automatically to maintain single-dose volumes at predetermined levels. Experimental results demonstrated that the proposed algorithm can regulate mean single-dose volumes with a variation of 98%. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Low-dose cyclophosphamide administered as daily or single dose enhances the antitumor effects of a therapeutic HPV vaccine

Science.gov (United States)

Peng, Shiwen; Lyford-Pike, Sofia; Akpeng, Belinda; Wu, Annie; Hung, Chien-Fu; Hannaman, Drew; Saunders, John R.; Wu, T.-C.

2012-01-01

Although therapeutic HPV vaccines are able to elicit systemic HPV-specific immunity, clinical responses have not always correlated with levels of vaccine-induced CD8+ T cells in human clinical trials. This observed discrepancy may be attributable to an immunosuppressive tumor microenvironment in which the CD8+ T cells are recruited. Regulatory T cells (Tregs) are cells that can dampen cytotoxic CD8+ T-cell function. Cyclophosphamide (CTX) is a systemic chemotherapeutic agent, which can eradicate immune cells, including inhibitory Tregs. The optimal dose and schedule of CTX administration in combination with immunotherapy to eliminate the Treg population without adversely affecting vaccine-induced T-cell responses is unknown. Therefore, we investigated various dosing and administration schedules of CTX in combination with a therapeutic HPV vaccine in a preclinical tumor model. HPV tumor-bearing mice received either a single preconditioning dose or a daily dose of CTX in combination with the pNGVL4a-CRT/E7(detox) DNA vaccine. Both single and daily dosing of CTX in combination with vaccine had a synergistic anti-tumor effect as compared to monotherapy alone. The potent antitumor responses were attributed to the reduction in Treg frequency and increased infiltration of HPV16 E7-specific CD8+ T cells, which led to higher ratios of CD8+/Treg and CD8+/CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs). There was an observed trend toward decreased vaccine-induced CD8+ T-cell frequency with daily dosing of CTX. We recommend a single, preconditioning dose of CTX prior to vaccination due to its efficacy, ease of administration, and reduced cumulative adverse effect on vaccine-induced T cells. PMID:23011589

Low-dose ketoconazole-fluconazole combination versus fluconazole in single doses for the treatment of vaginal candidiasis

Directory of Open Access Journals (Sweden)

Jan Susilo

2011-08-01

Full Text Available Background: Vaginal candidiasis (VC is one of the most common fungal diseases. Candida albicans is the most common causative fungus and has been isolated from more than 80% of specimens obtained from women with VC. Ketoconazole is the first orally active antifungal, the dosage for VC is 200 mg twice daily for 5 days. Fluconazole is the newer oral antifungal, its dosage for VC is a single oral dose of 150 mg. Since fluconazole 150 mg is considerably expensive, a single dose of 100 mg ketoconazole and 40 mg fluconazole in combination has been tested for the treatment of VC. The results showed that from 11 women with confirmed VC, 1-2 weeks after drug administration, the mycological culture was negative in 8 women, positive in 1 woman, and 2 woman lost to follow-up. This promising result led to the present study with the objective to confirm the efficacy and safety of the above combination in a formal clinical trial.Methods: A total of 165 female patients, aged 18 years or older, with the diagnosis of VC from clinical symptoms (pruritus or burning or excessive discharge and positive microscopic smear (pseudohyphae and/or yeast cells were randomized to receive a single dose of either keto-fluco combination (n = 85 or fluconazole (n = 80, and returnedfor follow-up visit on day 8.Results: Among these patients, 39 patients had negative baseline culture, leaving 126 patients eligible for efficacy evaluation. The mycological eradication in the keto-fluco group was 74.5% (41 patients from a total of 55 patients with available mycological culture, while that in the fluconazole group was 70.2% (40 patients from 57 patients with available culture and this difference was not significant. The clinical favorable response (clinical cure and clinical improvement in the keto-fluco arm (n = 60 was 98.3%, while that in the fluconazole group (n = 66 was 100%. Adverse events were found in 5 patients, 3 patients in the keto-fluco group (3/85 = 3.5% and 2

Implementation research: reactive mass vaccination with single-dose oral cholera vaccine, Zambia.

Science.gov (United States)

Poncin, Marc; Zulu, Gideon; Voute, Caroline; Ferreras, Eva; Muleya, Clara Mbwili; Malama, Kennedy; Pezzoli, Lorenzo; Mufunda, Jacob; Robert, Hugues; Uzzeni, Florent; Luquero, Francisco J; Chizema, Elizabeth; Ciglenecki, Iza

2018-02-01

To describe the implementation and feasibility of an innovative mass vaccination strategy - based on single-dose oral cholera vaccine - to curb a cholera epidemic in a large urban setting. In April 2016, in the early stages of a cholera outbreak in Lusaka, Zambia, the health ministry collaborated with Médecins Sans Frontières and the World Health Organization in organizing a mass vaccination campaign, based on single-dose oral cholera vaccine. Over a period of 17 days, partners mobilized 1700 health ministry staff and community volunteers for community sensitization, social mobilization and vaccination activities in 10 townships. On each day, doses of vaccine were delivered to vaccination sites and administrative coverage was estimated. Overall, vaccination teams administered 424 100 doses of vaccine to an estimated target population of 578 043, resulting in an estimated administrative coverage of 73.4%. After the campaign, few cholera cases were reported and there was no evidence of the disease spreading within the vaccinated areas. The total cost of the campaign - 2.31 United States dollars (US$) per dose - included the relatively low cost of local delivery - US$ 0.41 per dose. We found that an early and large-scale targeted reactive campaign using a single-dose oral vaccine, organized in response to a cholera epidemic within a large city, to be feasible and appeared effective. While cholera vaccines remain in short supply, the maximization of the number of vaccines in response to a cholera epidemic, by the use of just one dose per member of an at-risk community, should be considered.

Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

Science.gov (United States)

Huttner, Angela; Agnandji, Selidji Todagbe; Combescure, Christophe; Fernandes, José F; Bache, Emmanuel Bache; Kabwende, Lumeka; Ndungu, Francis Maina; Brosnahan, Jessica; Monath, Thomas P; Lemaître, Barbara; Grillet, Stéphane; Botto, Miriam; Engler, Olivier; Portmann, Jasmine; Siegrist, Denise; Bejon, Philip; Silvera, Peter; Kremsner, Peter; Siegrist, Claire-Anne

2018-04-04

The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose

Surface applicators for high dose rate brachytherapy in AIDS-related kaposi's sarcoma

International Nuclear Information System (INIS)

Evans, Michael D.C.; Yassa, Mariam; Podgorsak, Ervin B.; Roman, Ted N.; Schreiner, L. John; Souhami, Luis

1997-01-01

Purpose: The development of commercially available surface applicators using high dose rate remote afterloading devices has enabled radiotherapy centers to treat selected superficial lesions using a remote afterloading brachytherapy unit. The dosimetric parameters of these applicators, the clinical implementation of this technique, and a review of the initial patient treatment regimes are presented. Methods and Materials: A set of six fixed-diameter (1, 2, and 3 cm), tungsten/steel surface applicators is available for use with a single stepping-source (Ir-192, 370 GBq) high dose rate afterloader. The source can be positioned either in a parallel or perpendicular orientation to the treatment plane at the center of a conical aperture that sits at an SSD of approximately 15 mm and is used with a 1-mm thick removable plastic cap. The surface dose rates, percent depth dose, and off-axis ratios were measured. A custom-built, ceiling-mounted immobilization device secures the applicator on the surface of the patient's lesion during treatment. Results: Between November 1994, and September 1996, 16 AIDS-related Kaposi's sarcoma patients having a total of 120 lesions have been treated with palliative intent. Treatment sites were distributed between the head and neck, extremity, and torso. Doses ranged from 8 to 20 Gy, with a median dose of 10 Gy delivered in a single fraction. Treatments were well tolerated with minimal skin reaction, except for patients with lesions treated to 20 Gy who developed moderate/severe desquamation. Conclusion: Radiotherapy centers equipped with a high dose rate remote afterloading unit may treat small selected surface lesions with commercially available surface applicators. These surface applicators must be used with a protective cap to eliminate electron contamination. The optimal surface dose appears to be either 10 or 15 Gy depending upon the height of the lesion

Increased apoptotic potential and dose-enhancing effect of gold nanoparticles in combination with single-dose clinical electron beams on tumor-bearing mice

International Nuclear Information System (INIS)

Chang Mengya; Chen Yuhung; Chang Chihjui; Chen Helen H-W; Wu Chaoliang; Shiau Aili

2008-01-01

High atomic number material, such as gold, may be used in conjunction with radiation to provide dose enhancement in tumors. In the current study, we investigated the dose-enhancing effect and apoptotic potential of gold nanoparticles in combination with single-dose clinical electron beams on B16F10 melanoma tumor-bearing mice. We revealed that the accumulation of gold nanoparticles was detected inside B16F10 culture cells after 18 h of incubation, and moreover, the gold nanoparticles were shown to be colocalized with endoplasmic reticulum and Golgi apparatus in cells. Furthermore, gold nanoparticles radiosensitized melanoma cells in the colony formation assay (P=0.02). Using a B16F10 tumor-bearing mouse model, we further demonstrated that gold nanoparticles in conjunction with ionizing radiation significantly retarded tumor growth and prolonged survival compared to the radiation alone controls (P<0.05). Importantly, an increase of apoptotic signals was detected inside tumors in the combined treatment group (P<0.05). Knowing that radiation-induced apoptosis has been considered a determinant of tumor responses to radiation therapy, and the length of tumor regrowth delay correlated with the extent of apoptosis after single-dose radiotherapy, these results may suggest the clinical potential of gold nanoparticles in improving the outcome of melanoma radiotherapy. (author)

Hypertrophic Cardiomyopathy After a Single Dose of Dexamethasone in a Preterm Infant

Directory of Open Access Journals (Sweden)

Yusuf Kale

2015-08-01

Full Text Available Dexamethasone is widely used in preterm infants with severe pulmonary disease. Hypertrophic cardiomyopathy (HCM is a transient side effect observed after multiple doses of dexamethasone. We report a preterm infant with myocardial hypertrophy after a single dose of dexamethasone (0.5 mg/kg used to treat laryngeal edema secondary to prolonged intubation. A benign course was observed without left ventricular outflow tract obstruction and with recovery within 4 weeks. Myocardial effects of dexamethasone may be independent of dose and duration of treatment. The risk/benefit ratio must be carefully considered before using even a single dose of dexamethasone in preterm infants.

Coronary vasodilatory action after a single dose of nicorandil

NARCIS (Netherlands)

H. Suryapranata (Harry); P.W.J.C. Serruys (Patrick); P.J. de Feyter (Pim); P.D. Verdouw (Pieter); P.G. Hugenholtz (Paul)

1988-01-01

textabstractCoronary hemodynamics and vasodilatory effects on major epicardial arteries were investigated after a single dose of nicorandil in 22 patients undergoing cardiac catheterization for suspected coronary artery disease. Nicorandil, 20 mg, was administered sublingually to 11 consecutive

Single-dose and steady-state pharmacokinetics of diltiazem administered in two different tablet formulations

DEFF Research Database (Denmark)

Christrup, Lona Louring; Bonde, J; Rasmussen, S N

1992-01-01

Single-dose and steady state pharmacokinetics of diltiazem administered in two different oral formulations were assessed with particular reference to rate and extent of absorption. Following single dose administration a significant difference in tmax was observed (2.9 +/- 1.9 and 6.8 +/- 2.6 hr r...

HDRMC, an accelerated Monte Carlo dose calculator for high dose rate brachytherapy with CT-compatible applicators

Energy Technology Data Exchange (ETDEWEB)

Chibani, Omar, E-mail: omar.chibani@fccc.edu; C-M Ma, Charlie [Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 (United States)

2014-05-15

Purpose: To present a new accelerated Monte Carlo code for CT-based dose calculations in high dose rate (HDR) brachytherapy. The new code (HDRMC) accounts for both tissue and nontissue heterogeneities (applicator and contrast medium). Methods: HDRMC uses a fast ray-tracing technique and detailed physics algorithms to transport photons through a 3D mesh of voxels representing the patient anatomy with applicator and contrast medium included. A precalculated phase space file for the{sup 192}Ir source is used as source term. HDRM is calibrated to calculated absolute dose for real plans. A postprocessing technique is used to include the exact density and composition of nontissue heterogeneities in the 3D phantom. Dwell positions and angular orientations of the source are reconstructed using data from the treatment planning system (TPS). Structure contours are also imported from the TPS to recalculate dose-volume histograms. Results: HDRMC was first benchmarked against the MCNP5 code for a single source in homogenous water and for a loaded gynecologic applicator in water. The accuracy of the voxel-based applicator model used in HDRMC was also verified by comparing 3D dose distributions and dose-volume parameters obtained using 1-mm{sup 3} versus 2-mm{sup 3} phantom resolutions. HDRMC can calculate the 3D dose distribution for a typical HDR cervix case with 2-mm resolution in 5 min on a single CPU. Examples of heterogeneity effects for two clinical cases (cervix and esophagus) were demonstrated using HDRMC. The neglect of tissue heterogeneity for the esophageal case leads to the overestimate of CTV D90, CTV D100, and spinal cord maximum dose by 3.2%, 3.9%, and 3.6%, respectively. Conclusions: A fast Monte Carlo code for CT-based dose calculations which does not require a prebuilt applicator model is developed for those HDR brachytherapy treatments that use CT-compatible applicators. Tissue and nontissue heterogeneities should be taken into account in modern HDR

Epithelial regeneration of transposed intestine after high doses of X irradiation

Energy Technology Data Exchange (ETDEWEB)

Both, N.J. de; Vermey, M [Erasmus Universiteit, Rotterdam (Netherlands)

1976-01-01

The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of x irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation.

Epithelial regeneration of transposed intestine after high doses of X-irradiation

International Nuclear Information System (INIS)

Both, N.J. de; Vermey, M.

1976-01-01

The regeneration capacities of normal and transposed small bowel epithelium were compared in rats after applying high doses of X-irradiation. It has been shown that the potency of the mucosa to regenerate was much higher than assumed and that the mucosa could regenerate after single doses varying from 2000 to 5000 R. Even in the villus epithelium and in flat epithelium covering infiltrates of the lamina propria cells survived, which were still able to resume proliferative activity several days after irradiation. (author)

Effective dose comparison between stitched and single FOV in CBCT protocols for complete dental arcade

International Nuclear Information System (INIS)

Soares, Maria Rosangela; Batista, Wilson Otto; Antonio, Patricia Lara de; Caldas, Linda V.E.; Maia, Ana F.

2015-01-01

Objective: The objective of this study was to assess and compare protocols with a single field of view and multiple stitched field of view with a similar clinical purpose by means of effective dose value. Materials and methods: Measurements of absorbed dose were performed with thermoluminescent dosemeters inserted in the position of organs/tissues of a female anthropomorphic phantom and from these values the effective dose was calculated, utilizing weighting factor tissue-ICRP 103 (2007). Results: The results obtained in this study for effective dose are within the range of 43.1 µSv and 111.5 µSv for equipment using protocols with single FOV and in the range of 44.5 µSv and 236.2 µSv for equipments that using protocols with stitched field of view. Conclusions: In terms of the value of effective dose, stitched FOV protocols do not have any advantage over the single field of view protocols. This results suggest the necessity for knowledge of the exposure parameters and effective dose values associated with each image protocol. - Highlights: • The study relies on the comparison of two protocols with similar goals of CBCT: stitched protocols and single protocols. • The stitched FOV protocol is more specific and it is good option when want imaging only of some dental units. • In relation the effective dose, single FOV protocols presents advantage over the stitched FOV protocols. • Know the exposure parameters and effective dose values associated with each image protocol is necessity for request the best CBCT tomographic image

Single-dose and multiple-dose pharmacokinetics and dose proportionality of intravenous and intramuscular HPβCD-diclofenac (Dyloject) compared with other diclofenac formulations.

Science.gov (United States)

Mermelstein, Fred; Hamilton, Douglas A; Wright, Curtis; Lacouture, Peter G; Ramaiya, Atulkumar; Carr, Daniel B

2013-10-01

To evaluate single- and repeated-dose pharmacokinetics (PK) and dose proportionality of hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac compared with Voltarol after intravenous (IV) and intramuscular (IM) administration. Study 1: Single-dose randomized four-way crossover study. Study 2: Multiple-dose randomized three-way crossover study. Clinical research center. Healthy adult volunteers. Study 1: Subjects received HPβCD-diclofenac and Voltarol, IV and IM, with a 5-day washout between treatment periods. Study 2: Subjects received two doses of IV HPβCD-diclofenac and oral Cataflam once every 6 hours for four doses with a 48-hour washout period between treatment periods. Study 1: IV HPβCD-diclofenac had a higher peak plasma concentration (Cmax ) and earlier time to reach maximum plasma concentration (Tmax ), but equivalent plasma exposure (area under the curve from time zero to t [AUC0-t ]) to IV Voltarol. The geometric mean ratio of HPβCD-diclofenac (IV) to Voltarol (IV) for AUC0-t was 106.27%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IM) for AUC0-t was 110.91%. The geometric mean ratio of HPβCD-diclofenac (IV) to HPβCD-diclofenac (IM) for AUC0-t was 101.25%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IV) for AUC0-t was 104.96%. Study 2: Cmax for diclofenac was 2904 and 6031 ng/ml after the first IV dose of 18.75 and 37.5 mg HPβCD-diclofenac, respectively, and was 3090 and 5617 ng/ml after the fourth dose, indicating no accumulation. Plasma exposures to 18.75 mg (866 ng·hour/ml) and 37.5 mg (1843 ng·hour/ml) IV HPβCD-diclofenac bracketed that of oral Cataflam 50 mg (1473 ng·hour/ml). Study 1: Bioavailability in terms of AUC after IV administration was equivalent for HPβCD-diclofenac compared with Voltarol and after IM administration of HPβCD-diclofenac and Voltarol. Bioavailability in terms of AUC after IM administration of HPβCD-diclofenac was equivalent to IV administration of HP�

Single- and multiple-dose pharmacokinetics, pharmacodynamics, and safety of apixaban in healthy Chinese subjects

Directory of Open Access Journals (Sweden)

Cui Y

2013-12-01

Full Text Available Yimin Cui,1 Yan Song,2 Jessie Wang,2 Zhigang Yu,2 Alan Schuster,2 Yu Chen Barrett,2 Charles Frost2 1Peking University First Hospital, Beijing, People's Republic of China; 2Bristol-Myers Squibb, Princeton, NJ, USA Background: The pharmacokinetics (PK, pharmacodynamics (PD, and safety of apixaban were assessed in healthy Chinese subjects in this randomized, placebo-controlled, double-blind, single-sequence, single- and multiple-dose study. Subjects and methods: Eighteen subjects 18–45 years of age were randomly assigned (2:1 ratio to receive apixaban or matched placebo. Subjects received a single 10 mg dose of apixaban or placebo on day 1, followed by 10 mg apixaban or placebo twice daily for 6 days (days 4–9. The PK and PD of apixaban were assessed by collecting plasma samples for 72 hours following the dose on day 1 and the morning dose on day 9, and measuring apixaban concentration and anti-Xa activity. Safety was assessed via physical examinations, vital sign measurements, electrocardiograms, and clinical laboratory evaluations. Results: PK analysis showed similar characteristics of apixaban after single and multiple doses, including a median time to maximum concentration of ~3 hours, mean elimination half-life of ~11 hours, and renal clearance of ~1.2 L/hour. The accumulation index was 1.7, consistent with twice-daily dosing and the observed elimination half-life. Single-dose data predict multiple-dose PK, therefore apixaban PK are time-independent. The relationship between anti-Xa activity and plasma apixaban concentrations appears to be linear. Apixaban was safe and well tolerated, with no bleeding-related adverse events reported. Conclusion: Apixaban was safe and well tolerated in healthy Chinese subjects. Apixaban PK and PD were predictable and consistent with findings from previous studies in Asian and non-Asian subjects. The administration of apixaban does not require any dose modification based on race. Keywords: apixaban, oral

Biological dose estimation for accidental supra-high dose gamma-ray exposure

International Nuclear Information System (INIS)

Chen, Y.; Yan, X.K.; Du, J.; Wang, Z.D.; Zhang, X.Q.; Zeng, F.G.; Zhou, P.K.

2011-01-01

To correctly estimate the biological dose of victims accidentally exposed to a very high dose of 60 Co gamma-ray, a new dose-effect curve of chromosomal dicentrics/multicentrics and rings in the supra-high dose range was established. Peripheral blood from two healthy men was irradiated in vitro with doses of 60 Co gamma-rays ranging from 6 to 22 Gy at a dose rate of 2.0 Gy/min. Lymphocytes were concentrated, cultured and harvested at 52 h, 68 h and 72 h. The numbers of dic + r were counted. The dose-effect curves were established and validated using comparisons with doses from the Tokai-mura accident and were then applied to two victims of supra-high dose exposure accident. The results indicated that there were no significant differences in chromosome aberration frequency among the different culture times from 52 h to 72 h. The 6-22 Gy dose-effect curve was fitted to a linear quadratic model Y = -2.269 + 0.776D - 7.868 x l0 -3 D 2 . Using this mathematic model, the dose estimates were similar to data from Tokai-mura which were estimated by PCC ring. Whole body average doses of 9.7 Gy and 18.1 Gy for two victims in the Jining accident were satisfactorily given. We established and successfully applied a new dose-effect curve of chromosomal dicentrics plus ring (dic + r) after 6-22 Gy γ-irradiation from a supra-high dose 60 Co gamma-ray accident.

Management of urinary tract infections in pregnancy: a review with comments on single dose therapy.

Science.gov (United States)

Zinner, S H

1992-01-01

Most investigators agree that the adverse effects of urinary tract infections in pregnancy can be abrogated by effective early detection and treatment. However, the optimal methods for screening and treatment remain controversial. Although single-dose therapy has not been applied to pregnant women with acute pyelonephritis, most but not all studies which have compared single-dose with longer courses of beta-lactam or other antibiotics in pregnant asymptomatic bacteriuric women have shown no differences in outcome. This paper reviews recent trials of single-dose treatment of bacteriuria in pregnant women.

Marrow toxicity of fractionated vs. single dose total body irradiation is identical in a canine model

International Nuclear Information System (INIS)

Storb, R.; Raff, R.F.; Graham, T.; Appelbaum, F.R.; Deeg, H.J.; Schuening, F.G.; Shulman, H.; Pepe, M.

1993-01-01

The authors explored in dogs the marrow toxicity of single dose total body irradiation delivered from two opposing 60 Co sources at a rate of 10 cGy/min and compared results to those seen with total body irradiation administered in 100 cGy fractions with minimum interfraction intervals of 6 hr. Dogs were not given marrow transplants. They found that 200 cGy single dose total body irradiation was sublethal, with 12 of 13 dogs showing hematopoietic recovery and survival. Seven of 21 dogs given 300 cGy single dose total body irradiation survived compared to 6 of 10 dogs given 300 cGy fractionated total body irradiation. One of 28 dogs given 400 cGy single dose total body irradiation survived compared to none of six given fractionated radiation. With granulocyte colony stimulating factor (GCSF) administered from day 0-21 after 400 cGy total body irradiation, most dogs survived with hematological recovery. Because of the almost uniform success with GCSF after 400 cGy single dose total body irradiation, a study of GCSF after 400 cGy fractionated total body irradiation was deemed not to be informative and, thus, not carried out. Additional comparisons between single dose and fractionated total body irradiation were carried out with GCSF administered after 500 and 600 cGy of total body irradiation. As with lower doses of total body irradiation, no significant survival differences were seen between the two modes of total body irradiation, and only 3 of 26 dogs studied survived with complete hematological recovery. Overall, therefore, survival among dogs given single dose total body irradiation was not different from that of dogs given fractionated total body irradiation (p = .67). Similarly, the slopes of the postirradiation declines of granulocyte and platelet counts and the rates of their recovery in surviving dogs given equal total doses of single versus fractionated total body irradiation were indistinguishable. 24 refs., 3 figs., 2 tabs

Single and repeated dose pharmacokinetics of dexketoprofen trometamol in patients with impaired liver function.

Science.gov (United States)

Valles, J; Artigas, R; Bertolotti, M; Crea, A; Muller, F; Paredes, I; Capriati, A

2006-06-01

Dexketoprofen trometamol, a high water-soluble salt of the active enantiomer of rac-ketoprofen, is a nonsteroidal antiinflammatory drug (NSAID) used for pain relief. This study compared the pharmacokinetics of dexketoprofen in patients with impaired liver function and normal subjects following single and repeated oral dosing. Subjects with normal liver function (n = 6) and with Child-Pugh A (n = 7) or Child-Pugh B (n = 5) hepatic impairment scores completed this open-label and parallel study. They received 25 mg dexketoprofen (equivalent to 37 mg of its tromethamine salt) as a single (day 1) and a 3-day repeated dose (1 dose every 8 hours for a total of 10 doses). Dexketoprofen concentrations were determined in plasma and urine by reverse-phase high performance liquid chromatography (HPLC). Model-independent pharmacokinetic parameters were obtained. All subjects completed the study. No serious adverse events were recorded. Following the single dose, mean (+/- SEM) Cmax were 3027.7 +/- 429.3 ng/ml (healthy subjects), 2856.3 +/- 340.3 ng/ml (Child-Pugh A) and 1937.2 +/- 328.0 ng/ml (Child-Pugh B). Median tmax were 0.49 h (0.33-0.68) h, 0.50 h (0.33-0.67) h and 0.67 h (0.33-1.50) h. AUC0-x averaged 3778.0 +/- 439.0 ng.h/ml, 4890.4 +/- 539.1 ng.h/ml and 3985.0 +/- 712.0 ng.h/ml. Mean CL/F were 101.1 +/- 11.3 ml/h/kg, 73.3 +/- 9.9 ml/h/kg and 88.8 +/- 15.5 ml/h/kg and V/F averaged 0.192 +/- 0.018 l/kg, 0.162 +/- 0.006 l/kg and 0.214 +/- 0.044 l/kg. Following the repeated administration, similar results were obtained showing no drug accumulation. As related to the administered dose, median excretions of unchanged and conjugated dexketoprofen in urine were 2.1% and 67.1% in healthy subjects, 2.8% and 60.9% in Child-Pugh A subjects and 4.4% and 47.7% in Child-Pugh B volunteers. A trend towards a reduced urinary excretion of conjugated dexketoprofen in hepatic patients, more evident in the Child-Pugh B than in the Child-Pugh A groups, was observed when compared with healthy

Industrial-scale separation of high-purity single-chirality single-wall carbon nanotubes for biological imaging

Science.gov (United States)

Yomogida, Yohei; Tanaka, Takeshi; Zhang, Minfang; Yudasaka, Masako; Wei, Xiaojun; Kataura, Hiromichi

2016-01-01

Single-chirality, single-wall carbon nanotubes are desired due to their inherent physical properties and performance characteristics. Here, we demonstrate a chromatographic separation method based on a newly discovered chirality-selective affinity between carbon nanotubes and a gel containing a mixture of the surfactants. In this system, two different selectivities are found: chiral-angle selectivity and diameter selectivity. Since the chirality of nanotubes is determined by the chiral angle and diameter, combining these independent selectivities leads to high-resolution single-chirality separation with milligram-scale throughput and high purity. Furthermore, we present efficient vascular imaging of mice using separated single-chirality (9,4) nanotubes. Due to efficient absorption and emission, blood vessels can be recognized even with the use of ∼100-fold lower injected dose than the reported value for pristine nanotubes. Thus, 1 day of separation provides material for up to 15,000 imaging experiments, which is acceptable for industrial use. PMID:27350127

Pharmacokinetic interaction of enrofloxacin/trimethoprim combination following single-dose intraperitoneal and oral administration in rats.

Science.gov (United States)

Choi, Myung-Jin; Yohannes, Sileshi Belew; Lee, Seung-Jin; Damte, Dereje; Kim, Jong-Choon; Suh, Joo-Won; Park, Seung-Chun

2014-03-01

The pharmacokinetic interaction of enrofloxacin and trimethoprim was evaluated after single-dose intraperitoneal or oral co-administration in rats. Plasma concentrations of the two drugs were determined by high-performance liquid chromatography. Following intraperitoneal combination, a significant (P trimethoprim, respectively. There was a significant (P trimethoprim. Further study is recommended in other species of animals.

The effect of single and double doses of gamma radiation on pre-rigor mortis filleted saithe

International Nuclear Information System (INIS)

Underdahl, B.; Lunde, G.

1973-01-01

Saithe, caught off the western coast of Norway, were filleted immediately after killing, packed in plastic bags and irradiated using a cobalt-60 source at the Institutt for Atomenergi, Kjeller. The doses were 50, 100, 150, 50+50 and 50+100 krad. All samples were analysed for their total bacterial count, proteolytic activity, ammonia, total volatile acids, trimethylamine oxide, tri- and dimethylamine and formaldehyde. The organoleptic quality was evaluated by a panel of tasters. Double doses were more effective in reducing the total bacterial count than an equivalent single dose. A close relation was found between the bacterial count and the proteolytic activity. The trimethylamine oxide concentration was found to vary between 33 and 44 mg/100 g muscle, decreasing rapidly in non-irradiated fillets to 3 mg/100 g. In non-irradiated fillets trimethylamine oxide was mainly reduced to trimethylamine and in irradiated fillets to dimethylamine and formaldehyde. A split dose of 50+50 krad may have a favourable effect on the total bacterial number, but the analyses of proteolytic activity, the volatile acids and the trimethylamine indicate that a higher proportion of spoilage bacteria survive. The low proteolytic activity and the high content of DMA/FA prove that the split doses of 50+100 krad as compared with a single dose of 150 krad are particularly favourable in the case of saithe. (Auth.)

Regulatory T Cell Responses in Participants with Type 1 Diabetes after a Single Dose of Interleukin-2: A Non-Randomised, Open Label, Adaptive Dose-Finding Trial

Science.gov (United States)

Todd, John A.; Porter, Linsey; Smyth, Deborah J.; Rainbow, Daniel B.; Ferreira, Ricardo C.; Yang, Jennie H.; Bell, Charles J. M.; Schuilenburg, Helen; Challis, Ben; Clarke, Pamela; Coleman, Gillian; Dawson, Sarah; Goymer, Donna; Kennet, Jane; Brown, Judy; Greatorex, Jane; Goodfellow, Ian; Evans, Mark; Mander, Adrian P.; Bond, Simon; Wicker, Linda S.

2016-01-01

Background Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target. Aldesleukin (Proleukin; recombinant human IL-2), which is administered at high doses to activate the immune system in cancer immunotherapy, is now being repositioned to treat inflammatory and autoimmune disorders at lower doses by targeting Tregs. Methods and Findings To define the aldesleukin dose response for Tregs and to find doses that increase Tregs physiologically for treatment of T1D, a statistical and systematic approach was taken by analysing the pharmacokinetics and pharmacodynamics of single doses of subcutaneous aldesleukin in the Adaptive Study of IL-2 Dose on Regulatory T Cells in Type 1 Diabetes (DILT1D), a single centre, non-randomised, open label, adaptive dose-finding trial with 40 adult participants with recently diagnosed T1D. The primary endpoint was the maximum percentage increase in Tregs (defined as CD3+CD4+CD25highCD127low) from the baseline frequency in each participant measured over the 7 d following treatment. There was an initial learning phase with five pairs of participants, each pair receiving one of five pre-assigned single doses from 0.04 × 106 to 1.5 × 106 IU/m2, in order to model the dose-response curve. Results from each participant were then incorporated into interim statistical modelling to target the two doses most likely to induce 10% and 20% increases in Treg frequencies. Primary analysis of the evaluable population (n = 39) found that the optimal doses of aldesleukin to induce 10% and 20% increases in Tregs were 0.101 × 106 IU/m2 (standard error [SE] = 0.078, 95% CI = −0

Low- and high-dose laser irradiation effects on cell migration and destruction

Science.gov (United States)

Layton, Elivia; Gallagher, Kyra A.; Zukerman, Sara; Stevens, Brianna; Zhou, Feifan; Liu, Hong; Chen, Wei R.

2018-02-01

Metastases are the cause of more than 90 percent of cancer-related deaths. Current treatment methods, including chemotherapy, radiation, and surgery, fail to target the metastases effectively. One potential treatment for metastatic cancer is laser immunotherapy (LIT). LIT combines the use of a photothermal laser with an immunoadjuvant, Glycated Chitosan (GC). GC combined with single-walled carbon nanotubes (SWNTs) has proven to be a viable alternative to traditional cancer treatment methods, when under irradiation of laser with appropriate wavelength. In this study, the effects of low dose and high dose laser irradiation on metastatic pancreatic cancer cell migration were observed. It was found that low dose irradiation increased the migration rate, but the high dose irradiation significantly decreased the migration rate of the cancer cells. When using LIT, the goal is to kill tumor cells and to prompt the correct immune response. If the tumor were irradiated with a low dose, it would promote metastasis. If the dose of irradiation were too high, it would destroy the entire tumor and the immune response would not recognize the tumor. Therefore, the laser dose plays an important role in LIT, particularly when using SWNT as light absorbing agent. Our results from this study will delineate the optimal laser irradiation dose for destroying tumor cells and at the same time preserve and release tumor antigens as a precursor of antitumor immune response.

A quality improvement project to reduce the intraoperative use of single-dose fentanyl vials across multiple patients in a pediatric institution.

Science.gov (United States)

Buck, David; Subramanyam, Rajeev; Varughese, Anna

2016-01-01

The use of a single-dose vial across multiple patients presents a risk to sterility and is against CDC guidelines. We initiated a quality improvement (QI) project to reduce the intraoperative use of single-dose vials of fentanyl across multiple patients at Cincinnati Children's Hospital Medical Center (CCHMC). The initial step of the improvement project was the development of a Key Driver Diagram. The diagram has the SMART aim of the project, key drivers inherent to the process we are trying to improve, and specific interventions targeting the key drivers. The number of patients each week receiving an IV dose of fentanyl, from a vial previously accessed for another patient was tracked in a high turnover operating room (OR). The improvement model used was based on the concept of building Plan-Do-Study-Act (PDSA) cycles. Tests of change included provider education, provision of an increased number of fentanyl vials, alternate wasting processes, and provision of single-use fentanyl syringes by the pharmacy. Prior to initiation of this project, it was common for a single fentanyl vial to be accessed for multiple patients. Our data showed an average percentage of failures of just over 50%. During the end of the project, after 7 months, the mean percentage failures had dropped to 5%. Preparation of 20 mcg single-use fentanyl syringes by pharmacy, combined with education of providers on appropriate use, was successful in reducing failures to below our goal of 25%. Appropriately sized fentanyl syringes prepared by pharmacy, education on correct use of single-dose vials, and reminders in the OR, reduced the percentage of patients receiving a dose of fentanyl from a vial previously accessed for another patient in a high-volume otolaryngology room. © 2015 John Wiley & Sons Ltd.

Optimized dose distribution of a high dose rate vaginal cylinder

International Nuclear Information System (INIS)

Li Zuofeng; Liu, Chihray; Palta, Jatinder R.

1998-01-01

Purpose: To present a comparison of optimized dose distributions for a set of high-dose-rate (HDR) vaginal cylinders calculated by a commercial treatment-planning system with benchmark calculations using Monte-Carlo-calculated dosimetry data. Methods and Materials: Optimized dose distributions using both an isotropic and an anisotropic dose calculation model were obtained for a set of HDR vaginal cylinders. Mathematical optimization techniques available in the computer treatment-planning system were used to calculate dwell times and positions. These dose distributions were compared with benchmark calculations with TG43 formalism and using Monte-Carlo-calculated data. The same dwell times and positions were used for a quantitative comparison of dose calculated with three dose models. Results: The isotropic dose calculation model can result in discrepancies as high as 50%. The anisotropic dose calculation model compared better with benchmark calculations. The differences were more significant at the apex of the vaginal cylinder, which is typically used as the prescription point. Conclusion: Dose calculation models available in a computer treatment-planning system must be evaluated carefully to ensure their correct application. It should also be noted that when optimized dose distribution at a distance from the cylinder surface is calculated using an accurate dose calculation model, the vaginal mucosa dose becomes significantly higher, and therefore should be carefully monitored

Single-dose intravenous iron infusion or oral iron for treatment of fatigue after postpartum haemorrhage

DEFF Research Database (Denmark)

Holm, C; Thomsen, L L; Norgaard, A

2017-01-01

BACKGROUND AND OBJECTIVES: To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage. MATERIALS AND METHODS: Single-centre, open-label, ran......BACKGROUND AND OBJECTIVES: To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage. MATERIALS AND METHODS: Single-centre, open...

Progress in high-dose radiation dosimetry

International Nuclear Information System (INIS)

Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.; Chadwick, K.H.

1981-01-01

The last decade has witnessed a deluge of new high-dose dosimetry techniques and expanded applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Reference systems also include a number of chemical dose meters: ferrous sulphate, ferrous-cupric sulphate, and ceric sulphate acidic aqueous solutions. Requirements for stable and reliable transfer dose meters have led to further developments of several important high-dose systems: amino acids and saccharides analysed by ESR or lyoluminescence, thermoluminescent materials, radiochromic dyes and plastics, ceric-cerous solutions analysed by potentiometry, and ethanol-chlorobenzene solutions analysed by high-frequency oscillometry. A number of other prospective dose meters are also treated in this review. In addition, an IAEA programme of high-dose standardization and intercomparison for industrial radiation processing is described. (author)

A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin.

Science.gov (United States)

Belda, Walter; Di Chiacchio, Nilton G; Di Chiacchio, Nilton; Romiti, Ricardo; Criado, Paulo R; Velho, Paulo Eduardo N Ferreira

2009-06-01

A study was conducted in São Paulo, Brazil, to compare azithromycin with thiamphenicol for the single-dose treatment of chancroid. In all, 54 men with chancroid were tested. The etiology was determined by clinical characterization and direct bacterioscopy with Gram staining. None of the patients had positive serology or dark-field examination indicating active infection with Treponema pallidum. Genital infections due to Neisseria gonorrhoeae and herpes simplex virus were excluded by polymerase chain reaction testing. For 54 patients with chancroid, cure rates with single-dose treatment were 73% with azithromycin and 89% with thiamphenicol. HIV seropositivity was found to be associated with treatment failure (p=0.001). The treatment failed in all HIV positive patients treated with azithromycin (p=0.002) and this drug should be avoided in these co-infected patients. In the view of the authors, thiamphenicol is the most indicated single-dose regimen for chancroid treatment.

A Cohort Study of Preoperative Single Dose Versus Four Doses of Antibiotics for Patients With Non-Complicated Acute Appendicitis

Directory of Open Access Journals (Sweden)

Salah H. Al Janaby

2017-02-01

Full Text Available Objective: To Test the efficacy of single preoperative dose of Cefotaxime 1gm and Metronidazole 500mg in reducing the surgical site infections (SSIs after open appendectomy in patients with non-complicated appendicitis (NCA Place and Duration of Study: Al Hilla General Teaching Hospital, Babel Governorate-Iraq, from January 2013 to January 2014. Patients & Methods: 100 patients, who underwent appendectomy for NCA and fulfilled the selection criteria, were randomized into two groups. The patients in group A received a single dose of pre-operative antibiotics (Cefotaxime sodium and metronidazole, while the group B patients received three more dose of the same antibiotics postoperatively. Patients of both groups were followed-up for 30 days to assess the postoperative infective complications. Results: Group A had 48, while group B comprised of 52 patients. The groups were comparable in the baseline characteristics. Statistically, P value in rates of SSIs between both the groups was 0.9182. None of the patients developed intra-abdominal collection. Conclusion: Single dose of pre-operative antibiotics (Cefotaxime and metronidazole was sufficient in reducing the SSIs after appendectomy for NPA. Postoperative antibiotics did not add an appreciable clinical benefit in these patients. Key words: Preoperative antibiotics, Appendectomy, Surgical site infection, Non-complicated appendicitis Abbreviations: SSI: Surgical Site Infection, NCA: non-complicated appendicitis CDC Center of Disease Control.

Single and 30 fraction tumor control doses correlate in xenografted tumor models: implications for predictive assays

International Nuclear Information System (INIS)

Gerweck, Leo E.; Dubois, Willum; Baumann, Michael; Suit, Herman D.

1995-01-01

Purpose/Objective: In a previous publication we reported that laboratory assays of tumor clonogen number, in combination with intrinsic radiosensitivity measured in-vitro, accurately predicted the rank-order of single fraction 50% tumor control doses, in six rodent and xenografted human tumors. In these studies, tumor hypoxia influenced the absolute value of the tumor control doses across tumor types, but not their rank-order. In the present study we hypothesize that determinants of the single fraction tumor control dose, may also strongly influence the fractionaled tumor control doses, and that knowledge of tumor clonogen number and their sensitivity to fractionated irradiation, may be useful for predicting the relative sensitivity of tumors treated by conventional fractionated irradiation. Methods/Materials: Five tumors of human origin were used for these studies. Special care was taken to ensure that all tumor control dose assays were performed over the same time frame, i.e., in-vitro cells of a similar passage were used to initiate tumor sources which were expanded and used in the 3rd or 4th generation. Thirty fraction tumor control doses were performed in air breathing mice, under normal blood flow conditions (two fractions/day). The results of these studies have been previously published. For studies under uniformly (clamp) hypoxic conditions, tumors arising from the same transplantation were randomized into single or fractionated dose protocols. For estimation of the fractionated TCD50 under hypoxic conditions, tumors were exposed to six 5.4 Gy fractions (∼ 2 Gy equivalent under air), followed by graded 'top-up' dose irradiation for determination of the TCD50; the time interval between doses was 6-9 hours. The single dose equivalent of the six 5.4 Gy doses was used to calculate an extrapolated 30 fraction hypoxic TCD50. Results: Fractionation substantially increased the dose required for tumor control in 4 of the 5 tumors investigated. For these 4 tumors

Comparison of traditional low-dose-rate to optimized and nonoptimized high-dose-rate tandem and ovoid dosimetry

International Nuclear Information System (INIS)

Decker, William E.; Erickson, Beth; Albano, Katherine; Gillin, Michael

2001-01-01

Purpose: Few dose specification guidelines exist when attempting to perform high-dose-rate (HDR) dosimetry. The purpose of this study was to model low-dose-rate (LDR) dosimetry, using parameters common in HDR dosimetry, to achieve the 'pear-shape' dose distribution achieved with LDR tandem and ovoid applications. Methods and Materials: Radiographs of Fletcher-Suit LDR applicators and Nucletron 'Fletcher-like' HDR applicators were taken with the applicators in an idealized geometry. Traditional Fletcher loadings of 3M Cs-137 sources and the Theratronics Planning System were used for LDR dosimetry. HDR dosimetry was performed using the Nucletron Microselectron HDR UPS V11.22 with an Ir-192 source. Dose optimization points were initially located along a line 2 cm lateral to the tandem, beginning at the tandem tip at 0.5-cm intervals, ending at the sail, and optimized to 100% of the point A dose. A single dose optimization point was also placed laterally from the center of each ovoid equal to the radius of the ovoid (ovoid surface dose). For purposes of comparison, dose was also calculated for points A and B, and a point located 1 cm superior to the tandem tip in the plane of the tandem, (point F). Four- and 6-cm tandem lengths and 2.0-, 2.5-, and 3.0-cm ovoid diameters were used for this study. Based on initial findings, dose optimization schemes were developed to best approximate LDR dosimetry. Finally, radiographs were obtained of HDR applications in two patients. These radiographs were used to compare the optimization schemes with 'nonoptimized' treatment plans. Results: Calculated doses for points A and B were similar for LDR, optimized HDR, and nonoptimized HDR. The optimization scheme that used tapered dose points at the tandem tip and optimized a single ovoid surface point on each ovoid to 170% of point A resulted in a good approximation of LDR dosimetry. Nonoptimized HDR resulted in higher doses at point F, the bladder, and at points lateral to the tandem tip

Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

International Nuclear Information System (INIS)

Leith, J.T.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Howard, J.

1982-01-01

The thoraco-lumbar (T12-L1) region of the spinal cord of rats was exposed to either single or fractionated (four daily exposures) doses of X rays (230 kVp) or heavy ions. The heavy ions used were carbon and neon, and the relative biological effectiveness (RBE) of both the plateau ionization region and the midpeak region of 4-cm spread-out Bragg peaks of each heavy ion were investigated. For single doses of carbon and neon ions in the plateau ionization region, RBE values of 1.45 +/- 0.25 (propagated 95% confidence limits) and 1.46 +/- 0.33, respectively, were obtained. In the spread peak regions for carbon and neon ions, the RBE values were 1.48 +/- 0.18 and 1.86 +/- 0.42, respectively. These values were obtained using the dose needed to produce 50% paralysis in a group of irradiated rats as the isoeffect comparison dose (ED 50 dose). Similarly, in groups of rats receiving four daily exposures, the RBE values for carbon and neon ions in the plateau ionization region were 1.31 +/- 0.27 and 1.80 +/- 0.24, respectively. In the spread peak regions of ionization for carbon and neon ions, the RBE values were 1.95 +/- 0.19 and 2.18 +/- 0.23, respectively. Similar values for RBE were obtained using changes in the activity of enzymes in spinal cord tissue (cyclic nucleotide phosphohydrolase and γ-glutamyl transpeptidase). Also, it was estimated that, for X irradiation, the fractional amount of dose repaired (at the ED 50 dose) was 0.64 +/- 0.10 (95% confidence limits). For carbon and neon ions in the plateau ionization region, the values for the fractional amount of dose repaired were 0.70 +/- 0.27 and 0.48 +/- 0.20, and for carbon and neon ions in the spread peak region of ionization, the fractional repair values were 0.40 +/- 0.10 and 0.52 +/- 0.17. Spinal cord tissue therefore shows a high capacity for subeffective damage repair

Efficacy of various single-dose regimens of ceftriaxone in ...

African Journals Online (AJOL)

1990-08-18

Aug 18, 1990 ... The therapeutic efficacy of single intramuscular doses of ceftriaxone (Rocephin; Roche) (62,S, 125 and 250 mg), admini- stered without probenecid, was evaluated in 167 adult males with uncomplicated acute gonococcal urethritis. Cure rates of 100% were achieved at 62,5 mg and 250 mg. In the 125 mg.

Protective effect of hypoxia in the ram testis during single and split-dose X-irradiation

International Nuclear Information System (INIS)

Vliet, J. van; Wensing, C.J.G.; Bootsma, A.L.; Peperzeel, H.A. van; Schipper, J.

1988-01-01

Spertogonial stem-cell survival in the ram was studied after single (6Gy) and split-dose X-irradiation both under normal and hypoxic conditions. Hypoxia was induced by inflation of an occluder implanted around the testicular artery. The occluders were inflated about 10 min before irradiation and deflated immediately after. Stem-cell survival was measured at 5 or 7 weeks after irradiation by determination of the Repopulation Index (RI) in histological testis sections. The RI-values after fractionated irradiation were only half those after single dose irradiation. Hypoxia had a protective effect on the stem-cell survival. After split-dose irradiation under hypoxic conditions two times more stem cells survived than under normal oxic conditions; the RI-values increased from 34% (oxic) to 68% (hypoxic). This effect of hypoxia was also found after single dose irradiation where the RI-values increased from 68% (oxic) to 84% (hypoxic). The development of the epithelium in repopulated tubules was also studied. Under hypoxia, a significantly higher fraction of tubules with complete epithelium was found after single (38 vs. 4%) as well as after split-dose irradiation (12 vs. 0%)

Universal Survival Curve and Single Fraction Equivalent Dose: Useful Tools in Understanding Potency of Ablative Radiotherapy

International Nuclear Information System (INIS)

Park, Clint; Papiez, Lech; Zhang Shichuan; Story, Michael; Timmerman, Robert D.

2008-01-01

Purpose: Overprediction of the potency and toxicity of high-dose ablative radiotherapy such as stereotactic body radiotherapy (SBRT) by the linear quadratic (LQ) model led to many clinicians' hesitating to adopt this efficacious and well-tolerated therapeutic option. The aim of this study was to offer an alternative method of analyzing the effect of SBRT by constructing a universal survival curve (USC) that provides superior approximation of the experimentally measured survival curves in the ablative, high-dose range without losing the strengths of the LQ model around the shoulder. Methods and Materials: The USC was constructed by hybridizing two classic radiobiologic models: the LQ model and the multitarget model. We have assumed that the LQ model gives a good description for conventionally fractionated radiotherapy (CFRT) for the dose to the shoulder. For ablative doses beyond the shoulder, the survival curve is better described as a straight line as predicted by the multitarget model. The USC smoothly interpolates from a parabola predicted by the LQ model to the terminal asymptote of the multitarget model in the high-dose region. From the USC, we derived two equivalence functions, the biologically effective dose and the single fraction equivalent dose for both CFRT and SBRT. Results: The validity of the USC was tested by using previously published parameters of the LQ and multitarget models for non-small-cell lung cancer cell lines. A comparison of the goodness-of-fit of the LQ and USC models was made to a high-dose survival curve of the H460 non-small-cell lung cancer cell line. Conclusion: The USC can be used to compare the dose fractionation schemes of both CFRT and SBRT. The USC provides an empirically and a clinically well-justified rationale for SBRT while preserving the strengths of the LQ model for CFRT

Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

Science.gov (United States)

Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

2017-02-01

This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

Stability in the rumen and effect on plasma status of single oral doses of vitamin D and vitamin E in high-yielding dairy cows

DEFF Research Database (Denmark)

Hymøller, Lone; Jensen, Søren Krogh

2010-01-01

The ruminal fate of the fat-soluble vitamins D and E was studied in dairy cows. Ten to 15 kg of ruminal contents was taken from each cow through a ruminal fistula. A sample was taken out (0-h sample) and the rest of the contents were mixed with 4,360 mg of all-rac-α-tocopheryl acetate (vitamin E;...... a single dose of α-tocopheryl acetate led to the conclusion that oral single dose therapy with all-rac-α-tocopheryl acetate is of limited physiological value....

The D1 method: career dose estimation from a combination of historical monitoring data and a single year's dose data

International Nuclear Information System (INIS)

Sont, W.N.

1995-01-01

A method is introduced to estimate career doses from a combination of historical monitoring data and a single year's dose data. This method, called D1 eliminates the bias arising from incorporating historical dose data from times when occupational doses were generally much higher than they are today. Doses calculated by this method are still conditional on the preservation of the status quo in the effectiveness of radiation protection. The method takes into account the variation of the annual dose, and of the probability of being monitored, with the time elapsed since the start of a career. It also allows for the calculation of a standard error of the projected career dose. Results from recent Canadian dose data are presented. (author)

Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

Energy Technology Data Exchange (ETDEWEB)

Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Santangelo, Teresa [CHU Lille (EA 2694) University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Bambino Gesu Children' s Hospital, Department of Imaging, Rome (Italy); Duhamel, Alain [University of Lille (EA 2694), Department of Biostatistics, CHU Lille, Lille (France); Deschildre, Antoine [CHU Lille - University of Lille, Department of Pediatric Pulmonology, Lille (France)

2017-02-15

The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol{sub 32}) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP{sub 32} was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP{sub 32}, CTDI{sub vol32} and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP{sub 32}, 0.78-1.25 mGy for the CTDI{sub vol32} and 1.6-2.1 mGy for the SSDE. (orig.)

Radiation dose levels in pediatric chest CT: experience in 499 children evaluated with dual-source single-energy CT

International Nuclear Information System (INIS)

Martine, Remy-Jardin; Colas, Lucie; Jean-Baptiste, Faivre; Remy, Jacques; Santangelo, Teresa; Duhamel, Alain; Deschildre, Antoine

2017-01-01

The availability of dual-source technology has introduced the possibility of scanning children at lower kVp with a high-pitch mode, combining high-speed data acquisition and high temporal resolution. To establish the radiation dose levels of dual-source, single-energy chest CT examinations in children. We retrospectively recorded the dose-length product (DLP) of 499 consecutive examinations obtained in children <50 kg, divided into five weight groups: group 1 (<10 kg, n = 129); group 2 (10-20 kg, n = 176); group 3 (20-30 kg, n = 99), group 4 (30-40 kg, n = 58) and group 5 (40-49 kg, n = 37). All CT examinations were performed with high temporal resolution (75 ms), a high-pitch mode and a weight-adapted selection of the milliamperage. CT examinations were obtained at 80 kVp with a milliamperage ranging between 40 mAs and 90 mAs, and a pitch of 2.0 (n = 162; 32.5%) or 3.0 (n = 337; 67.5%). The mean duration of data acquisition was 522.8 ± 192.0 ms (interquartile range 390 to 610; median 490). In the study population, the mean CT dose index volume (CTDIvol 32 ) was 0.83 mGy (standard deviation [SD] 0.20 mGy; interquartile range 0.72 to 0.94; median 0.78); the mean DLP 32 was 21.4 mGy.cm (SD 9.1 mGy.cm; interquartile range 15 to 25; median 19.0); and the mean size-specific dose estimate (SSDE) was 1.7 mGy (SD 0.4 mGy; interquartile range 1.5 to 1.9; median 1.7). The DLP 32 , CTDI vol32 and SSDE were found to be statistically significant in the five weight categories (P < 0.0001). This study establishes the radiation dose levels for dual-source, single-kVp chest CT from a single center. In the five weight categories, the median values varied 15-37 mGy.cm for the DLP 32 , 0.78-1.25 mGy for the CTDI vol32 and 1.6-2.1 mGy for the SSDE. (orig.)

Perioperative single high dose ATG-Fresenius S administration as induction immunosuppressive therapy in cadaveric renal transplantation--preliminary results.

Science.gov (United States)

Samsel, R; Chmura, A; Włodarczyk, Z; Wyzgał, J; Cieciura, T; Lagiewska, B; Pliszczyński, J; Korczak, G; Lazowski, T; Paczek, L; Wałaszewski, J; Lao, M; Rowiński, W

1999-01-01

Monoclonal and polyclonal antilymphocyte antibodies have been used successfully in organ transplantation as induction therapy and in the treatment of acute graft rejection. Used for induction the medication is generally given for the first 7-10 days. The aim of this study was to assess the safety and efficacy of single high dose (9 mg/kg) ATG Fresenius S given perioperatively, before revascularization, to kidney allograft recipients. During last twelve months seventy six, first cadaveric kidney adult recipients were included into the study in two centers (center A-64, center B-12). All patients received triple drug immunosuppression (Neoral, steroids and Cellcept which was replaced by azathioprine after 4 months), and were randomized to receive ATG or not. The follow-up period ranged from 1 month up to 1 year. The preliminary results are very promising, the rejection rate in bolus group was significantly lower than in control. No significant side effects or serious adverse events in both groups were observed.

Single dose (400 mg) versus 7 day (200 mg) daily dose itraconazole in the treatment of tinea versicolor: a randomized clinical trial.

Science.gov (United States)

Wahab, M A; Ali, M E; Rahman, M H; Chowdhury, S A; Monamie, N S; Sultana, N; Khondoker, L

2010-01-01

Tinea (pityriasis) versicolor is a superficial fungal infection and one of the most commonly found pigmentary disorders of skin caused by the yeast Malassezia. Multiple topical as well as systemic therapies are available for treatment. Systemic therapies are used for extensive disease, frequent relapse or where topical agents have failed. The aim that translates the rationale of the study was to compare the efficacy, safety, tolerability and cost effectiveness of single dose 400mg versus 7 day 200 mg daily dose of itraconazole in the treatment of tinea versicolor. A clinical study was done to compare the efficacy of single dose (400 mg) of itraconazole and 7 day 200 mg daily dose of itraconazole in the treatment of extensive tinea versicolor. Total 60 patients (aged 18-50 years) were selected for the study during the period of June 2007 to May 2008 in the department of Dermatology of three different hospitals in Bangladesh. Cases having with extensive involvement, diagnosed clinically and confirmed by wood's lamp and KOH microscopy were taken. Patients were randomly allocated into equal groups. Group A was given single dose 400 mg itraconazole and Group B was given 7 day 200 mg daily itraconazole. Fifty three (88%) male and 7(12%) female were included in the study. The mean age of group A was 32.37+/-9 years and in group B 33.23+/-8 years. The mean duration of the disease in group A was 2.63+/-2 months and 2.76+/-2 months in group B. In group A clinical responders was found cure 22(73.33%) and improvement 5(16.33%) and in group B it was found cure 24(79.99%) and improvement 4(13.33%). The measure at the End point (EP1) equals to 90% response and in-group B it was found cure 24 (79.99%) and improvement 4(13.33%). (Here the End point EP2) equals to 93.33%. The EP clinical analysis however shows 91.66% response. Both single dose and 7 day daily dose of itraconazole can be effective in the treatment of tinea versicolor with extensive involvement but single dose appears

A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin

Directory of Open Access Journals (Sweden)

Walter B. Junior

Full Text Available A study was conducted in São Paulo, Brazil, to compare azithromycin with thiamphenicol for the single-dose treatment of chancroid. In all, 54 men with chancroid were tested. The etiology was determined by clinical characterization and direct bacterioscopy with Gram staining. None of the patients had positive serology or dark-field examination indicating active infection with Treponema pallidum. Genital infections due to Neisseria gonorrhoeae and herpes simplex virus were excluded by polymerase chain reaction testing. For 54 patients with chancroid, cure rates with single-dose treatment were 73% with azithromycin and 89% with thiamphenicol. HIV seropositivity was found to be associated with treatment failure (p=0.001. The treatment failed in all HIV positive patients treated with azithromycin (p=0.002 and this drug should be avoided in these co-infected patients. In the view of the authors, thiamphenicol is the most indicated single-dose regimen for chancroid treatment.

Intracranial meningiomas after high-dose irradiation

International Nuclear Information System (INIS)

Soffer, D.; Gomori, J.M.; Siegal, T.; Shalit, M.N.

1989-01-01

Three patients who presented with intracranial meningiomas 12, 15, and 20 years, respectively, after therapeutic high-dose irradiation of a primary brain tumor are described. Analysis of these cases and similar documented cases suggests that meningiomas after high-dose irradiation constitute a recognizable entity. Patients with such tumors received radiation therapy at a young age (mean age, 9.4 years). After a latent period of 2 to 47 years (mean, 19.8 years) they developed meningiomas at the site of irradiation, at a much younger age than patients with ''spontaneous'' meningiomas. Similar to the situation with meningiomas after low-dose irradiation, a relatively high proportion of meningiomas induced by high-dose irradiation tend to be malignant and biologically aggressive. A very young age at the time of irradiation seems to predispose to the induction of malignant meningiomas, rather than benign tumors. These unusual features provide indirect evidence that high-dose radiation may play a role in the pathogenesis of meningiomas.41 references

Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

Science.gov (United States)

Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

2011-01-01

Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

Favorable Preliminary Outcomes for Men With Low- and Intermediate-risk Prostate Cancer Treated With 19-Gy Single-fraction High-dose-rate Brachytherapy

Energy Technology Data Exchange (ETDEWEB)

Krauss, Daniel J., E-mail: dkrauss@beaumont.edu [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Ye, Hong [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Martinez, Alvaro A. [21st Century Oncology, Farmington Hills, Michigan (United States); Mitchell, Beth; Sebastian, Evelyn; Limbacher, Amy; Gustafson, Gary S. [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States)

2017-01-01

Purpose: To report the toxicity and preliminary clinical outcomes of a prospective trial evaluating 19-Gy, single-fraction high-dose-rate (HDR) brachytherapy for men with low- and intermediate-risk prostate cancer. Methods and Materials: A total of 63 patients were treated according to an institutional review board-approved prospective study of single-fraction HDR brachytherapy. Eligible patients had tumor stage ≤T2a, prostate-specific antigen level ≤15 ng/mL, and Gleason score ≤7. Patients with a prostate gland volume >50 cm{sup 3} and baseline American Urologic Association symptom score >12 were ineligible. Patients underwent transrectal ultrasound-guided transperineal implantation of the prostate, followed by single-fraction HDR brachytherapy. Treatment was delivered using {sup 192}Ir to a dose of 19 Gy prescribed to the prostate, with no additional margin applied. Results: Of the 63 patients, 58 had data available for analysis. Five patients had withdrawn consent during the follow-up period. The median follow-up period was 2.9 years (range 0.3-5.2). The median age was 61.4 years. The median gland volume at treatment was 34.8 cm{sup 3}. Of the 58 patients, 91% had T1 disease, 71% had Gleason score ≤6 (29% with Gleason score 7), and the median pretreatment prostate-specific antigen level was 5.1 ng/mL. The acute and chronic grade 2 genitourinary toxicity incidence was 12.1% and 10.3%, respectively. No grade 3 urinary toxicity occurred. No patients experienced acute rectal toxicity grade ≥2, and 2 experienced grade ≥2 chronic gastrointestinal toxicity. Three patients experienced biochemical failure, yielding a 3-year cumulative incidence estimate of 6.8%. Conclusions: Single-fraction HDR brachytherapy is well-tolerated, with favorable preliminary biochemical and clinical disease control rates.

Comparison of single-grain and small-aliquot OSL dose estimates in < 3000 years old river sediments from South India

DEFF Research Database (Denmark)

Thomas, P.J.; Jain, M.; Juyal, N.

2005-01-01

We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there wa......We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples......, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from similar to 1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons...... perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal. (c) 2004 Elsevier Ltd. All rights reserved....

Implication of fractionated dose exposures in therapeutic gain

International Nuclear Information System (INIS)

Kim, Hye-Jin; Lee, Min-Ho; Kim, Eun-Hee

2016-01-01

Radiation therapy pursues killing tumor cells while sparing normal cells from the radiation exposure. Stereotactic radiosurgery (SRS) is a cancer treatment modality that delivers a high dose in a single operation. This high-dose single operation shortens the treatment course, but can increase the risk of normal cell damage. Normal cell damage can be reduced by employing multi-directional exposures for an increasing number of isocenters. In this study, we investigated whether therapeutic benefits would be expected by employing new dose fractionation patterns at a high-dose single operation. The conventional single-dose operation in brain tumor radiosurgery is performed by delivering fractionated uniform doses. According to Figs. 2 and 3, the conventional radiosurgery might have obtained some therapeutic benefit by employing the fractionated uniform-dose exposures instead of a single-dose exposure. We suggest that further therapeutic gain be expected by employing the fractionated radiation exposures in an increasing dose pattern. Until ensuring our suggestion, the significance in gain of cell surviving should be verified for all three dose patterns with both normal and tumor cells. The investigation whether normal and tumor cells show the same responses to the fractionated dose exposures at lower and higher than 15 Gy of total dose is also reserved for future work

PHARMACOKINETICS OF SINGLE-DOSE ORALLY ADMINISTERED CIPROFLOXACIN IN CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS).

Science.gov (United States)

Barbosa, Lorraine; Johnson, Shawn P; Papich, Mark G; Gulland, Frances

2015-06-01

Ciprofloxacin is commonly selected for clinical use due to its broad-spectrum efficacy and is a frequently administered antibiotic at The Marine Mammal Center, a marine mammal rehabilitation facility. Ciprofloxacin is used for treatment of California sea lions ( Zalophus californianus ) suffering from a variety of bacterial infections at doses extrapolated from other mammalian species. However, as oral absorption is variable both within and across species, a more accurate determination of appropriate dosage is needed to ensure effective treatment and avoid emergence of drug-resistant bacterial strains. A pharmacokinetic study was performed to assess plasma concentrations of ciprofloxacin in California sea lions after a single oral dose. Twenty healthy California sea lions received a single 10-mg/kg oral dose of ciprofloxacin administered in a herring fish. Blood was then collected at two of the following times from each individual: 0.5, 0.75, 1, 2, 4, 8, 10, 12, 18, and 24 hr postingestion. Plasma ciprofloxacin concentration was assessed via high-performance liquid chromatography. A population pharmacokinetics model demonstrated that an oral ciprofloxacin dose of 10 mg/kg achieved an area under the concentration vs. time curve of 6.01 μg hr/ml. Absorption was rapid, with ciprofloxacin detectable in plasma 0.54 hr after drug administration; absorption half-life was 0.09 hr. A maximum plasma concentration of 1.21 μg/ml was observed at 1.01 hr, with an elimination half-life of 3.09 hr. Ciprofloxacin administered orally at 10 mg/kg produced therapeutic antibacterial exposure for only some of the most susceptible bacterial organisms commonly isolated from California sea lions.

Pharmacokinetics of colistin methanesulfonate (CMS) in healthy Chinese subjects after single and multiple intravenous doses.

Science.gov (United States)

Zhao, Miao; Wu, Xiao-Jie; Fan, Ya-Xin; Zhang, Ying-Yuan; Guo, Bei-Ning; Yu, Ji-Cheng; Cao, Guo-Ying; Chen, Yuan-Cheng; Wu, Ju-Fang; Shi, Yao-Guo; Li, Jian; Zhang, Jing

2018-05-01

The high prevalence of extensively drug-resistant Gram-negative pathogens has forced clinicians to use colistin as a last-line therapy. Knowledge on the pharmacokinetics of colistin methanesulfonate (CMS), an inactive prodrug, and colistin has increased substantially; however, the pharmacokinetics in the Chinese population is still unknown due to lack of a CMS product in China. This study aimed to evaluate the pharmacokinetics of a new CMS product developed in China in order to optimise dosing regimens. A total of 24 healthy subjects (12 female, 12 male) were enrolled in single- and multiple-dose pharmacokinetic (PK) studies. Concentrations of CMS and formed colistin in plasma and urine were measured, and PK analysis was conducted using a non-compartmental approach. Following a single CMS dose [2.36 mg colistin base activity (CBA) per kg, 1 h infusion], peak concentrations (C max ) of CMS and formed colistin were 18.0 mg/L and 0.661 mg/L, respectively. The estimated half-life (t 1/2 ) of CMS and colistin were 1.38 h and 4.49 h, respectively. Approximately 62.5% of the CMS dose was excreted via urine within 24 h after dosing, whilst only 1.28% was present in the form of colistin. Following multiple CMS doses, colistin reached steady-state within 24 h; there was no accumulation of CMS, but colistin accumulated slightly (R AUC  = 1.33). This study provides the first PK data in the Chinese population and is essential for designing CMS dosing regimens for use in Chinese hospitals. The urinary PK data strongly support the use of intravenous CMS for serious urinary tract infections. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Pharmacokinetics of terbinafine after oral administration of a single dose to Hispaniolan Amazon parrots (Amazona ventralis).

Science.gov (United States)

Evans, Erika E; Emery, Lee C; Cox, Sherry K; Souza, Marcy J

2013-06-01

To determine pharmacokinetics after oral administration of a single dose of terbinafine hydrochloride to Hispaniolan Amazon parrots (Amazona ventralis). 6 healthy adult Hispaniolan Amazon parrots. A single dose of terbinafine hydrochloride (60 mg/kg) was administered orally to each bird, which was followed immediately by administration of a commercially available gavage feeding formula. Blood samples were collected at the time of drug administration (time 0) and 0.25, 0.5, 1, 2, 4, 8, 12, and 24 hours after drug administration. Plasma concentrations of terbinafine were determined via high-performance liquid chromatography. Data from 1 bird were discarded because of a possible error in the dose of drug administered. After oral administration of terbinafine, the maximum concentration for the remaining 5 fed birds ranged from 109 to 671 ng/mL, half-life ranged from 6 to 13.5 hours, and time to the maximum concentration ranged from 2 to 8 hours. No adverse effects were observed. Analysis of the results indicated that oral administration of terbinafine at a dose of 60 mg/kg to Amazon parrots did not result in adverse effects and may be potentially of use in the treatment of aspergillosis. Additional studies are needed to determine treatment efficacy and safety.

Comparison of single-grain and small-aliquot OSL dose estimates in <3000 years old river sediments from South India

International Nuclear Information System (INIS)

Thomas, P.J.; Jain, M.; Juyal, N.; Singhvi, A.K.

2005-01-01

We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from ∼1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons for the discrepancy between single-grain and small-aliquot dose estimates are discussed. Although there is no satisfactory explanation for this discrepancy, we speculate that the difference in the stimulation wavelengths, 470+/-30nm in the case of single-aliquot and 532nm in the case of single grains, could perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal

Dose performance and image quality: Dual source CT versus single source CT in cardiac CT angiography

International Nuclear Information System (INIS)

Wang Min; Qi Hengtao; Wang Ximing; Wang Tao; Chen, Jiu-Hong; Liu Cheng

2009-01-01

Objective: To evaluate dose performance and image quality of 64-slice dual source CT (DSCT) in comparison to 64-slice single source CT (SSCT) in cardiac CT angiography (CTA). Methods: 100 patients examined by DSCT and 60 patients scanned by SSCT were included in this study. Objective indices such as image noise, contrast-to-noise ratio and signal-to-noise ratio were analyzed. Subjective image quality was assessed by two cardiovascular radiologists in consensus using a four-point scale (1 = excellent to 4 = not acceptable). Estimation of effective dose was performed on the basis of dose length product (DLP). Results: At low heart rates ( 0.05), but, at high heart rates (>70 bpm), DSCT provided robust image quality (P 70 bpm), DSCT is able to provide robust diagnostic image quality at doses far below that of SSCT.

Single-dose Rituximab Therapy for Refractory Idiopathic Membranous Nephropathy: A Single-center Experience

OpenAIRE

Katsuno, Takayuki; Ozaki, Takenori; Kim, Hangsoo; Kato, Noritoshi; Suzuki, Yasuhiro; Akiyama, Shinichi; Ishimoto, Takuji; Kosugi, Tomoki; Tsuboi, Naotake; Ito, Yasuhiko; Maruyama, Shoichi

2017-01-01

To date, a recognized treatment for refractory membranous nephropathy (MN) has not been established. Recently, several reports have indicated the efficacy of rituximab as a novel treatment option. However, only a few published accounts exist of rituximab therapy for idiopathic MN (IMN) in the Asian population. We present the cases of three IMN patients who were treated with single-dose rituximab after they showed no response to conventional therapies, including corticosteroids, cyclosporine, ...

The Efficacy of Single-Dose versus Double-Dose Praziquantel Treatments on Schistosoma mansoni Infections: Its Implication on Undernutrition and Anaemia among Primary Schoolchildren in Two On-Shore Communities, Northwestern Tanzania

Science.gov (United States)

Buza, Joram; Mpolya, Emmanuel A.; Angelo, Teckla; Kinung'hi, Safari M.

2017-01-01

Administering more than one treatment may increase Praziquantel cure and egg reduction rates, thereby hastening achievement of schistosomiasis transmission control. A total of 431 S. mansoni-infected schoolchildren were randomized to receive either a single or repeated 40 mg/kg Praziquantel dose. Heights, weights, and haemoglobin levels were determined using a stadiometer, weighing scale, and HemoCue, respectively. At 8 weeks, cure rate was higher on repeated dose (93.10%) compared to single dose (68.68%) (p 0.05) and 8 (p > 0.05) months with no difference in reinfection rate. No difference in the prevalence of stunting was observed between the two treatment regimens (p > 0.05) at 8 months, but there was an increase in the prevalence of wasting among those on repeated dose (p 0.05). To achieve reduction of transmission intensity and disease control in highly endemic areas, repeated treatments alone may not be sufficient. This trial was registered with PACTR201601001416338. PMID:29094048

High-dose irradiation of food

International Nuclear Information System (INIS)

Diehl, J.F.

1999-01-01

Studies performed on behalf of the International Project on Food Irradiation in the period from 1971 until 1980 resulted in the concluding statement that ''.the irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard; hence, toxicological testing of foods so treated is no longer required.'' Since then, licenses for food irradiation have been restricted to this maximum dose in any country applying this technology. Further testing programmes have been carried out investigating the wholesomeness or hazards of high-dose irradiation, but there has been little demand so far by the food industry for licensing of high-dose irradiation, as there is only a small range of products whose irradiation at higher doses offers advantages for given, intended use. These include eg. spices, dried herbs, meat products in flexible pouch packagings for astronauts, or patients with immune deficiencies. (orig./CB) [de

Application of the luminescence single-aliquot technique for dose estimation in the Marmara Sea

International Nuclear Information System (INIS)

Tanir, Guenes; Sencan, Emine; Boeluekdemir, M. Hicabi; Tuerkoez, M. Burak; Tel, Eyuep

2005-01-01

The aim of this study is to obtain the equivalent dose, which is the important quantity for all the studies related to the use of luminescence in dating sediments. Recent advances in luminescence dating have led to increasing application of the technique to sediment from the depositional environmental samples. The sample used in this study is the active main fault sample that was collected from the Sea of Marmara in NW Turkey. Equivalent dose was measured using both the multiple-aliquots and the single-aliquot techniques. In this study single aliquot regeneration on additive dose (SARA) procedure was also used. The result obtained was not in agreement with the results evaluated from the multiple-aliquots procedure. So a simple modification was suggested for SARA procedure. In our modified procedure the calculated dose (D) values were obtained by using the additive dose protocol instead of regeneration protocol

''Low dose'' and/or ''high dose'' in radiation protection: A need to setting criteria for dose classification

International Nuclear Information System (INIS)

Sohrabi, M.

1997-01-01

The ''low dose'' and/or ''high dose'' of ionizing radiation are common terms widely used in radiation applications, radiation protection and radiobiology, and natural radiation environment. Reading the title, the papers of this interesting and highly important conference and the related literature, one can simply raise the question; ''What are the levels and/or criteria for defining a low dose or a high dose of ionizing radiation?''. This is due to the fact that the criteria for these terms and for dose levels between these two extreme quantities have not yet been set, so that the terms relatively lower doses or higher doses are usually applied. Therefore, setting criteria for classification of radiation doses in the above mentioned areas seems a vital need. The author while realizing the existing problems to achieve this important task, has made efforts in this paper to justify this need and has proposed some criteria, in particular for the classification of natural radiation areas, based on a system of dose limitation. (author)

Improvements in dose calculation accuracy for small off-axis targets in high dose per fraction tomotherapy

Energy Technology Data Exchange (ETDEWEB)

Hardcastle, Nicholas; Bayliss, Adam; Wong, Jeannie Hsiu Ding; Rosenfeld, Anatoly B.; Tome, Wolfgang A. [Department of Human Oncology, University of Wisconsin-Madison, WI, 53792 (United States); Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, VIC 3002 (Australia) and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Department of Human Oncology, University of Wisconsin-Madison, WI 53792 (United States); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia) and Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Einstein Institute of Oncophysics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461 (United States) and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia)

2012-08-15

Purpose: A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. Methods: The correction method, termed 'Super Sampling' involved the tripling of the number of gantry angles from which the dose is calculated during optimization and dose calculation. Radiochromic film was used to measure the dose to small targets at various off-axis distances receiving a minimum of 21 Gy in one fraction. Measurements were also performed for single small targets at the center of the Lucy phantom, using radiochromic film and the dose magnifying glass (DMG). Results: Without super sampling, the peak dose deficit increased from 0% to 18% for a 10 mm target and 0% to 30% for a 5 mm target as off-axis target distances increased from 0 to 16.5 cm. When super sampling was turned on, the dose deficit trend was removed and all peak doses were within 5% of the planned dose. For measurements in the Lucy phantom at 9.7 cm off-axis, the positional and dose magnitude accuracy using super sampling was verified using radiochromic film and the DMG. Conclusions: A correction method implemented in the TomoTherapy treatment planning system which triples the angular sampling of the gantry angles used during optimization and dose calculation removes the underdosing for targets as small as 5 mm diameter, up to 16.5 cm off-axis receiving up to 21 Gy.

Improvements in dose calculation accuracy for small off-axis targets in high dose per fraction tomotherapy

International Nuclear Information System (INIS)

Hardcastle, Nicholas; Bayliss, Adam; Wong, Jeannie Hsiu Ding; Rosenfeld, Anatoly B.; Tomé, Wolfgang A.

2012-01-01

Purpose: A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. Methods: The correction method, termed “Super Sampling” involved the tripling of the number of gantry angles from which the dose is calculated during optimization and dose calculation. Radiochromic film was used to measure the dose to small targets at various off-axis distances receiving a minimum of 21 Gy in one fraction. Measurements were also performed for single small targets at the center of the Lucy phantom, using radiochromic film and the dose magnifying glass (DMG). Results: Without super sampling, the peak dose deficit increased from 0% to 18% for a 10 mm target and 0% to 30% for a 5 mm target as off-axis target distances increased from 0 to 16.5 cm. When super sampling was turned on, the dose deficit trend was removed and all peak doses were within 5% of the planned dose. For measurements in the Lucy phantom at 9.7 cm off-axis, the positional and dose magnitude accuracy using super sampling was verified using radiochromic film and the DMG. Conclusions: A correction method implemented in the TomoTherapy treatment planning system which triples the angular sampling of the gantry angles used during optimization and dose calculation removes the underdosing for targets as small as 5 mm diameter, up to 16.5 cm off-axis receiving up to 21 Gy.

Fractionated stereotactic radiation therapy and single high-dose radiosurgery for acoustic neuroma: early results of a prospective clinical study

International Nuclear Information System (INIS)

Meijer, O.W.M.; Wolbers, J.G.; Baayen, J.C.; Slotman, B.J.

2000-01-01

Purpose: To prospectively assess the local control and toxicity rate in acoustic neuroma patients treated with linear accelerator-based radiosurgery and fractionated stereotactic radiation therapy. Methods and Materials: We evaluated 37 consecutive patients treated with stereotactic radiation therapy for acoustic neuroma. All patients had progressive tumors, progressive symptoms, or both. Mean tumor diameter was 2.3 cm (range 0.8-3.3) on magnetic resonance (MR) scan. Dentate patients were given a dose of 5 x 4 Gy or 5 x 5 Gy and edentate patients were given a dose of 1 x 10 Gy or 1 x 12.50 Gy prescribed to the 80% isodose. All patients were treated with a single isocenter. Results: With a mean follow-up period of 25 months (range 12-61), the actuarial local control rate at 5 years was 91% (only 1 patient failed). The actuarial rate of hearing preservation at 5 years was 66% in previously-hearing patients. The actuarial rate of freedom from trigeminal nerve toxicity was 97% at 5 years. No patient developed facial nerve toxicity or other complications. Conclusion: In this unselected series, fractionated stereotactic radiation therapy and linear accelerator-based radiosurgery give excellent local control in acoustic neuroma. It combines a high rate of preservation of hearing with a very low rate of other toxicity, although follow-up is relatively short

Effect of Low-Dose (Single-Dose Magnesium Sulfate on Postoperative Analgesia in Hysterectomy Patients Receiving Balanced General Anesthesia

Directory of Open Access Journals (Sweden)

Arman Taheri

2015-01-01

Full Text Available Background and Aim. Aparallel, randomized, double blinded, placebo-controlled trial study was designed to assess the efficacy of single low dose of intravenous magnesium sulfate on post-total abdominal hysterectomy (TAH pain relief under balanced general anesthesia. Subject and Methods. Forty women undergoing TAH surgery were assigned to two magnesium sulfate (N=20 and normal saline (N=20 groups randomly. The magnesium group received magnesium sulfate 50 mg·kg−1 in 100 mL of normal saline solution i.v as single-dose, just 15 minutes before induction of anesthesia whereas patients in control group received 100 mL of 0.9% sodium chloride solution at the same time. The same balanced general anesthesia was induced for two groups. Pethidine consumption was recorded over 24 hours precisely as postoperative analgesic. Pain score was evaluated with Numeric Rating Scale (NRS at 0, 6, 12, and 24 hours after the surgeries. Results. Postoperative pain score was lower in magnesium group at 6, 12, and 24 hours after the operations significantly (P<0.05. Pethidine requirement was significantly lower in magnesium group throughout 24 hours after the surgeries (P=0.0001. Conclusion. Single dose of magnesium sulfate during balanced general anesthesia could be considered as effective and safe method to reduce postoperative pain and opioid consumption after TAH.

Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation

International Nuclear Information System (INIS)

Xiao Yao; Guo Hong-Xia; Zhang Feng-Qi; Zhao Wen; Wang Yan-Ping; Zhang Ke-Ying; Ding Li-Li; Luo Yin-Hong; Wang Yuan-Ming; Fan Xue

2014-01-01

Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. (interdisciplinary physics and related areas of science and technology)

Evaluation of the Pharmacokinetics of Single- and Multiple-dose Buprenorphine Buccal Film in Healthy Volunteers.

Science.gov (United States)

Bai, Stephen A; Xiang, Qinfang; Finn, Andrew

2016-02-01

Buprenorphine, a partial μ-receptor agonist, is approved for the management of moderate to severe pain, but it has low oral bioavailability. Two open-label studies were performed to determine the pharmacokinetic profile of buprenorphine from buccal film formulations of buprenorphine. Both studies enrolled healthy volunteers, aged 18 to 55 years, who received concurrent oral naltrexone to reduce adverse events (AEs); subjects with a history or evidence of substance abuse or current use of any product affecting cytochrome P450 3A4 activity were excluded. The first study (n = 25) was a 5-period crossover trial with 4 single doses (75 and 300 and 300 and 1200 μg) of 2 formulations (F14 and F24) of buccal buprenorphine (BBUP) and a 300-μg intravenous dose of buprenorphine with a 7-day washout between periods. In the second study, each subject (n = 10) received 6 doses of 4 BBUP strengths (60, 120, 180, and 240 μg BID) in a dose-escalation design. Plasma concentrations of buprenorphine and norbuprenorphine were assayed, and pharmacokinetics were summarized with descriptive statistics and analyzed by using a linear mixed effects model (single-dose study). AEs were recorded. In the single-dose study, the 2 formulations exhibited comparable bioavailability of 46% to 51% that was independent of dose, with a single buprenorphine peak concentration from each BBUP dose occurring at 2.5 to 3 hours. The mean buprenorphine Cmax across the doses ranged from 0.17 ng/mL for the 75-µg dose to 1.43 ng/mL for the 1200-µg dose. AUC0-∞, AUC0-last, and Cmax were proportional to the dose of BBUP administered. Cmax of norbuprenorphine after BBUP administration was approximately one tenth that of buprenorphine Cmax. In the multiple-dose study, steady state was reached within 3 days of BID dosing. There was a linear increase in exposure across the dose range from 60 to 240 μg BID. Treatment-emergent AEs in both studies were consistent with those reported with opiate administration to

Hepatitis A vaccine. A new convenient single-dose schedule with booster when long-term immunization is warranted

DEFF Research Database (Denmark)

Victor, J; Knudsen, J D; Nielsen, L P

1994-01-01

A total of 162 anti-HAV-negative healthy adults were immunized with a single high dose (1440 ELISA units = 1 ml) of inactivated hepatitis A vaccine and a booster was given at month 6. Antibodies were measured after modification of a commercial ELISA kit, enabling quantification of titres down to 6...

A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects

Directory of Open Access Journals (Sweden)

Ana Amélia Machado DUARTE

Full Text Available ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes were divided into two groups: 10 subjects in the white chocolate (7.4 g group and 21 in the dark chocolate (10 g group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

Serum tocopherol levels in very preterm infants after a single dose of vitamin E at birth.

Science.gov (United States)

Bell, Edward F; Hansen, Nellie I; Brion, Luc P; Ehrenkranz, Richard A; Kennedy, Kathleen A; Walsh, Michele C; Shankaran, Seetha; Acarregui, Michael J; Johnson, Karen J; Hale, Ellen C; Messina, Lynn A; Crawford, Margaret M; Laptook, Abbot R; Goldberg, Ronald N; Van Meurs, Krisa P; Carlo, Waldemar A; Poindexter, Brenda B; Faix, Roger G; Carlton, David P; Watterberg, Kristi L; Ellsbury, Dan L; Das, Abhik; Higgins, Rosemary D

2013-12-01

Our aim was to examine the impact of a single enteral dose of vitamin E on serum tocopherol levels. The study was undertaken to see whether a single dose of vitamin E soon after birth can rapidly increase the low α-tocopherol levels seen in very preterm infants. If so, this intervention could be tested as a means of reducing the risk of intracranial hemorrhage. Ninety-three infants vitamin E or placebo by gastric tube within 4 hours of birth. The vitamin E group received 50 IU/kg of vitamin E as dl-α-tocopheryl acetate (Aquasol E). The placebo group received sterile water. Blood samples were taken for measurement of serum tocopherol levels by high-performance liquid chromatography before dosing and 24 hours and 7 days after dosing. Eighty-eight infants received the study drug and were included in the analyses. The α-tocopherol levels were similar between the groups at baseline but higher in the vitamin E group at 24 hours (median 0.63 mg/dL vs. 0.42 mg/dL, P = .003) and 7 days (2.21 mg/dL vs 1.86 mg/dL, P = .04). There were no differences between groups in γ-tocopherol levels. At 24 hours, 30% of vitamin E infants and 62% of placebo infants had α-tocopherol levels vitamin E raised serum α-tocopherol levels, but to consistently achieve α-tocopherol levels >0.5 mg/dL, a higher dose or several doses of vitamin E may be needed.

Pharmacokinetics of pregabalin controlled-release in healthy volunteers: effect of food in five single-dose, randomized, clinical pharmacology studies.

Science.gov (United States)

Chew, Marci L; Plotka, Anna; Alvey, Christine W; Pitman, Verne W; Alebic-Kolbah, Tanja; Scavone, Joseph M; Bockbrader, Howard N

2014-09-01

pregabalin CR and IR. Bioequivalence criteria for comparison of pregabalin CR after a low- or medium-calorie breakfast relative to pregabalin IR were not met; however, bioavailability of the pregabalin CR vs. IR formulation was relatively high (75-86 %). When pregabalin CR was administered fasted, the AUC∞ was 70-78 % of the AUC∞ of pregabalin CR administered with food and bioequivalence criteria were not met. Additionally, the AUC∞ of the pregabalin CR formulation administered fasted was 62-69 % of that of pregabalin IR administered fasted and bioequivalence criteria were not met. Single-dose pregabalin CR and IR were well tolerated in all studies, with no serious or severe adverse events reported. Time of day of administration and the fat and caloric content of the accompanying meal had minimal overall effect on the pharmacokinetic properties and bioavailability of the pregabalin CR formulation.

Acute cognitive effects of high doses of dextromethorphan relative to triazolam in humans

Science.gov (United States)

Carter, Lawrence P.; Reissig, Chad J.; Johnson, Matthew W.; Klinedinst, Margaret A.; Griffiths, Roland R.

2012-01-01

BACKGROUND Although concerns surrounding high-dose dextromethorphan (DXM) abuse have recently increased, few studies have examined the acute cognitive effects of high doses of DXM. The aim of this study was to compare the cognitive effects of DXM with those of triazolam and placebo. METHODS Single, acute, oral doses of DXM (100, 200, 300, 400, 500, 600, 700, 800 mg/70 kg), triazolam (0.25, 0.5 mg /70 kg), and placebo were administered p.o. to twelve healthy volunteers with histories of hallucinogen use, under double-blind conditions, using an ascending dose run-up design. Effects on cognitive performance were examined at baseline and after drug administration for up to 6 hours. RESULTS Both triazolam and DXM produced acute impairments in attention, working memory, episodic memory, and metacognition. Impairments observed following doses of 100-300 mg/70 kg DXM were generally smaller in magnitude than those observed after 0.5 mg/70 kg triazolam. Doses of DXM that impaired performance to the same extent as triazolam were in excess of 10-30 times the therapeutic dose of DXM. CONCLUSION The magnitude of the doses required for these effects and the absence of effects on some tasks within the 100-300 mg/70 kg dose range of DXM, speak to the relatively broad therapeutic window of over-the-counter DXM preparations when used appropriately. However, the administration of supratherapeutic doses of DXM resulted in acute cognitive impairments on all tasks that were examined. These findings are likely relevant to cases of high-dose DXM abuse. PMID:22989498

Dose-reduction techniques for high-dose worker groups in nuclear power plants

International Nuclear Information System (INIS)

Khan, T.A.; Baum, J.W.; Dionne, B.J.

1991-03-01

This report summarizes the main findings of a study of the extent of radiation dose received by special work groups in the nuclear power industry. Work groups which chronically get large doses were investigated, using information provided by the industry. The tasks that give high doses to these work groups were examined and techniques described that were found to be particularly successful in reducing dose. Quantitative information on the extent of radiation doses to various work groups shows that significant numbers of workers in several critical groups receive doses greater than 1 and even 2 rem per year, particularly contract personnel and workers at BWR-type plants. The number of radiation workers whose lifetime dose is greater than their age is much less. Although the techniques presented would go some way in reducing dose, it is likely that a sizeable reduction to the high-dose work groups may require development of new dose-reduction techniques as well as major changes in procedures. 10 refs., 26 tabs

Performance of thermoluminescent materials for high dose dosimetry

International Nuclear Information System (INIS)

Texeira, Maria I.; Cecatti, Sonia G.P.; Caldas, Linda V.E.

2008-01-01

Cases involving high-doses of ionizing radiation are becoming increasingly common.The objective of this work was to characterize thermoluminescent materials for the dosimetry of workers exposed to high doses. Samples of TLD-200, TLD-400 and TLD-800 pellets from Thermo Electron Corporation were studied in gamma high-doses. Dose-response curves were obtained for doses between 100 mGy and 100 Gy. The reproducibility, the lower detection limits and dose-response curves were obtained for all three materials. The different kinds of detectors show usefulness for dosimetry of workers exposed accidentally to high doses. (author)

Is a single dose of meningococcal serogroup C conjugate vaccine sufficient for protection? experience from the Netherlands

Directory of Open Access Journals (Sweden)

Kaaijk Patricia

2012-02-01

Full Text Available Abstract Background The first meningococcal serogroup C (MenC conjugate vaccine was licensed in 1999 and introduced in the United Kingdom. Countries that have implemented the MenC vaccine since then in their national immunisation programmes use different schedules. Nevertheless, all involved countries seem to experience substantial declines in the incidence of MenC disease. Discussion Since 2001, the MenC conjugate vaccine has been implemented in the Netherlands by offering a single dose to all children aged 14 months. Prior to the introduction of the vaccine into the national immunisation programme, a catch-up vaccination campaign was initiated in which a single dose of the MenC conjugate vaccine was offered to all children aged from 14 months up to and including 18 years. Since then, there has been no report of any case of MenC disease among immunocompetent vaccinees. Administration of a single dose of MenC conjugate vaccine after infancy could be beneficial considering the already complex immunisation schedules with large numbers of vaccinations in the first year of life. The present paper deals with the advantages and critical aspects of a single dose of the MenC conjugate vaccine. Summary A single dose of MenC conjugate vaccine at the age of 14 months in combination with a catch up vaccine campaign appeared to be a successful strategy to prevent MenC disease in the Netherlands, thereby confirming that a single dose of the vaccine could sufficiently protect against disease. Nevertheless, this approach can only be justified in countries with a relatively low incidence of serogroup C meningococcal disease in the first year of life. Furthermore, a good surveillance programme is recommended for timely detection of vaccine breakthroughs and outbreaks among non-vaccinees, since long-term protection after a single dose in the second year of life cannot currently be guaranteed.

Combination of High-Dose Methylprednisolone and Defibrotide for Veno-Occlusive Disease in Pediatric Hematopoietic Stem Cell Transplant Recipients.

Science.gov (United States)

Gloude, Nicholas J; Jodele, Sonata; Teusink-Cross, Ashley; Grimley, Michael; Davies, Stella M; Lane, Adam; Myers, Kasiani C

2018-01-01

Veno-occlusive disease (VOD) is a serious complication of hematopoietic stem cell transplant (HSCT), with high mortality in severe cases and until recently very limited therapeutic options consisting largely of supportive care. Defibrotide was recently approved in the United States for the treatment of severe VOD in patients with renal or pulmonary dysfunction after HSCT. Our group previously published on the use of high-dose methylprednisolone (500 mg/m 2 per dose every 12 hours for 6 doses) in patients with VOD, showing good success. A small subset of these individuals were also treated with defibrotide, but additional studies using the combination of high-dose methylprednisolone and defibrotide for the treatment of VOD are lacking. We present a single-institution retrospective chart review of 15 HSCT patients with VOD treated with the combination of high-dose methylprednisolone and defibrotide. VOD developed at a median of 17 days post-HSCT, and combination therapy was initiated within 1 day of VOD diagnosis. Twelve of 15 patients (80%) had multiorgan failure. Our single-center experience using both high-dose methylprednisolone and defibrotide showed a day +100 survival rate of 73% and an overall VOD complete resolution rate of 66.7%, higher than the rates reported in the recent literature using defibrotide alone (40% to 50% day +100 overall survival). These data suggest that the combination of high-dose steroids and defibrotide may be superior to defibrotide alone and warrant further investigation. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Study of single dose toxic test of Sweet Bee Venom in Beagle Dogs

Directory of Open Access Journals (Sweden)

Hye-Chul, Yoon

2010-12-01

Full Text Available Objectives : This study was performed to analyse single dose toxicity of Sweet Bee Venom(Sweet BV extracted from the bee venom in Beagle dogs. Methods : All experiments were conducted under the regulations of Good Laboratory Practice (GLP at Biotoxtech Company, a non-clinical study authorized institution. Male and female Beagle dogs of 5-6 months old were chosen for the pilot study of single dose toxicity of Sweet BV which was administered at the level of 9.0 ㎎/㎏ body weight which is 1300 times higher than the clinical application dosage as the high dosage, followed by 3.0 and 1.0 ㎎/㎏ as midium and low dosage, respectively. Equal amount of excipient(normal saline to the Sweet BV experiment groups was administered as the control group. Results : 1. No mortality was witnessed in all of the experiment groups. 2. Hyperemia and movement disorder were observed around the area of administration in all the experiment groups, and higher occurrence in the higher dosage treatment. 3. For weight measurement, Neither male nor female groups showed significant changes. 4. To verify abnormalities of organs and tissues, thigh muscle which treated with Sweet BV, brain, liver, lung, kidney, and spinal cords were removed and histologocal observation using H-E staining was conducted. In the histologocal observation of thigh muscle, cell infiltration, inflammation, degeneration, necrosis of muscle fiber, and fibrosis were found in both thigh tissue. And the changes depend on the dose of Sweet BV. But the other organs did not showed in any abnormality. 5. The maximum dose of Sweet BV in Beagle dogs were over 9 ㎎/㎏ in this study. Conclusions : The above findings of this study suggest that Sweet BV is a relatively safe treatment medium. Further studies on the toxicity of Sweet BV should be conducted to yield more concrete evidences.

Feasibility of optimizing the dose distribution in lung tumors using fluorine-18-fluorodeoxyglucose positron emission tomography and single photon emission computed tomography guided dose prescriptions

International Nuclear Information System (INIS)

Das, S.K.; Miften, M.M.; Zhou, S.; Bell, M.; Munley, M.T.; Whiddon, C.S.; Craciunescu, O.; Baydush, A.H.; Wong, T.; Rosenman, J.G.; Dewhirst, M.W.; Marks, L.B.

2004-01-01

The information provided by functional images may be used to guide radiotherapy planning by identifying regions that require higher radiation dose. In this work we investigate the dosimetric feasibility of delivering dose to lung tumors in proportion to the fluorine-18-fluorodeoxyglucose activity distribution from positron emission tomography (FDG-PET). The rationale for delivering dose in proportion to the tumor FDG-PET activity distribution is based on studies showing that FDG uptake is correlated to tumor cell proliferation rate, which is shown to imply that this dose delivery strategy is theoretically capable of providing the same duration of local control at all voxels in tumor. Target dose delivery was constrained by single photon emission computed tomography (SPECT) maps of normal lung perfusion, which restricted irradiation of highly perfused lung and imposed dose-function constraints. Dose-volume constraints were imposed on all other critical structures. All dose-volume/function constraints were considered to be soft, i.e., critical structure doses corresponding to volume/function constraint levels were minimized while satisfying the target prescription, thus permitting critical structure doses to minimally exceed dose constraint levels. An intensity modulation optimization methodology was developed to deliver this radiation, and applied to two lung cancer patients. Dosimetric feasibility was assessed by comparing spatially normalized dose-volume histograms from the nonuniform dose prescription (FDG-PET proportional) to those from a uniform dose prescription with equivalent tumor integral dose. In both patients, the optimization was capable of delivering the nonuniform target prescription with the same ease as the uniform target prescription, despite SPECT restrictions that effectively diverted dose from high to low perfused normal lung. In one patient, both prescriptions incurred similar critical structure dosages, below dose-volume/function limits

Fiber optics in high dose radiation fields

International Nuclear Information System (INIS)

Partin, J.K.

1985-01-01

A review of the behavior of state-of-the-art optical fiber waveguides in high dose (greater than or equal to 10 5 rad), steady state radiation fields is presented. The influence on radiation-induced transmission loss due to experimental parameters such as dose rate, total dose, irradiation history, temperature, wavelength, and light intensity, for future work in high dose environments are given

Pharmacokinetics of voriconazole after oral administration of single and multiple doses in African grey parrots (Psittacus erithacus timneh).

Science.gov (United States)

Flammer, Keven; Nettifee Osborne, Julie A; Webb, Donna J; Foster, Laura E; Dillard, Stacy L; Davis, Jennifer L

2008-01-01

To determine the pharmacokinetics and safety of orally administered voriconazole in African grey parrots. 20 clinically normal Timneh African grey parrots (Psittacus erithacus timneh). In single-dose trials, 12 parrots were each administered 6, 12, and 18 mg of voriconazole/kg orally and plasma concentrations of voriconazole were determined via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) was administered orally to 6 birds every 12 hours for 9 days; a control group (2 birds) received tap water. Treatment effects were assessed via observation, clinicopathologic analyses (3 assessments), and measurement of trough plasma voriconazole concentrations (2 assessments). Voriconazole's elimination half-life was short (1.1 to 1.6 hours). Higher doses resulted in disproportional increases in the maximum plasma voriconazole concentration and area under the curve. Trough plasma voriconazole concentrations achieved in the multiple-dose trial were lower than those achieved after administration of single doses. Polyuria (the only adverse treatment effect) developed in treated and control birds but was more severe in the treatment group. In African grey parrots, voriconazole has dose-dependent pharmacokinetics and may induce its own metabolism. Oral administration of 12 to 18 mg of voriconazole/kg twice daily is a rational starting dose for treatment of African grey parrots infected with Aspergillus or other fungal organisms that have a minimal inhibitory concentration for voriconazole treatment. Safety and efficacy of various voriconazole treatment regimens in this species require investigation.

Bile duct evaluation of potential living liver donors with Gd-EOB-DTPA enhanced MR cholangiography: Single-dose, double dose or half-dose contrast enhanced imaging

Energy Technology Data Exchange (ETDEWEB)

Kinner, Sonja, E-mail: Sonja.Kinner@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Steinweg, Verena [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Maderwald, Stefan [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Radtke, Arnold; Sotiropoulos, Georgios [Department of General Surgery, University Hospital Essen (Germany); Forsting, Michael; Schroeder, Tobias [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany)

2014-05-15

Introduction: Detailed knowledge of the biliary anatomy is essential to avoid complications in living donor liver transplantation. The aim of this study was to determine the optimal dosage of Gd-EOB-DTPA for contrast-enhanced magnetic resonance cholangiography (ce-MRC) with reference to contrast-enhanced CT cholangiography (ce-CTC). Materials and methods: 30 potential living liver donors (PLLD) underwent both ce-CTC and ce-MRC. Ten candidates each received single, double or half-dose Gd-EOB-DTPA. Ce-MRC images with and without inversion recovery pulses (T1w ± IR) were acquired 20–30 min after intravenous contrast injection. Image data was quantitatively and qualitatively reviewed by two radiologists based on a on a 5-point scale. Data sets were compared using a Mann–Whitney-U-test or Wilcoxon-rank-sum-test. Kappa values were also calculated. Results: All image series provided sufficient diagnostic information both showing normal biliary anatomy and variant bile ducts. Ce-CTC showed statistically significant better results compared to all ce-MRC data sets. T1w MRC with single dose Gd-EOB-DTPA proved to be superior to half and double dose in subjective and objective evaluation without a statistically significant difference. Conclusions: Ce-MRC is at any dosage inferior to ce-CTC. As far as preoperative planning of bile duct surgery is focused on the central biliary anatomy, ce-MRC can replace harmful ce-CTC strategies, anyway. Best results were seen with single dose GD-EOB-DTPA on T1w MRC+IR.

High-Dose-Rate Brachytherapy of a Single Implant With Two Fractions Combined With External Beam Radiotherapy for Hormone-Naive Prostate Cancer

International Nuclear Information System (INIS)

Sato, Morio; Mori, Takashi; Shirai, Shintaro; Kishi, Kazushi; Inagaki, Takeshi; Hara, Isao

2008-01-01

Purpose: To evaluate the preliminary outcomes of high-dose-rate (HDR) brachytherapy of a single implant with two fractions and external beam radiotherapy (EBRT) for hormone-naive prostate cancer. Methods and Materials: Between March 2000 and Sept 2003, a total of 53 patients with tumor Stage T1c-T3b N0 M0 prostate cancer were treated with HDR brachytherapy boost doses (7.5 Gy/fraction) and 50-Gy EBRT during a 5.5-week period. Median follow-up was 61 months. Patients were divided into groups with localized (T1c-T2b) and advanced disease (T3a-T3b). We used the American Society for Therapeutic Radiology and Oncology (ASTRO) definition for biochemical failure. According to recommendations of the Radiation Therapy Oncology Group-ASTRO Phoenix Consensus Conference, biochemical failure-free control rates (BF-FCRs) at 3 years were investigated as 2 years short of the median follow-up. Results: Between April 2000 and Sept 2007, Common Terminology Criteria for Adverse Events Version 2.0 late Grade 2 genitourinary and gastrointestinal toxicity rates were 0% and 3.8%, respectively. Erectile preservation was 25% at 5 years. Overall survival was 88.1% and cause-specific survival was 100%. At 3 years, ASTRO BF-FCRs of the localized and advanced groups were 100% and 42%, respectively (p = 0.001). Conclusions: The HDR brachytherapy of a single implant with two fractions plus EBRT is effective in treating patients with localized hormone-naive prostate cancer, with the least genitourinary and gastrointestinal toxicities; however, longer median BF-FCR follow-up is required to assess these findings

Radiophotoluminescence light scope for high-dose dosimetry

International Nuclear Information System (INIS)

Sato, Fuminobu; Zushi, Naoki; Sakiyama, Tomoki; Kato, Yushi; Murata, Isao; Shimizu, Kikuo; Yamamoto, Takayoshi; Iida, Toshiyuki

2015-01-01

A radiophotoluminescence (RPL) light scope is a remote-sensing technique for measuring in situ the radiation dose in an RPL detector placed at a distance. The RPL light scope is mainly composed of an ultraviolet (UV) pulse laser, telescopic lenses, a photomultiplier tube, and camera modules. In a performance test, some RPL detectors were placed at distances up to 30 m and were illuminated with a pulsed UV laser beam. The photoluminescence responses of the RPL detectors were analyzed using this scope. Their radiation doses were determined from the amplitude of the given component of the photoluminescence responses. The RPL readout could be repeated without fading, and its amplitude exhibited good linearity at a dose ranging from 0.1 to 60 Gy. Furthermore, a two-dimensional distribution of radiation dose was obtained by laser scanning on an RPL detector. It was confirmed that the RPL light scope was a useful remote-sensing tool for high-dose dosimetry. - Highlights: • A radiophotoluminescence (RPL) light scope was developed for high-dose dosimetry. • The RPL light scope has high sensitivity and accuracy in high-dose dosimetry. • Two-dimensional radiation dose distribution was obtained by the RPL light scope.

Neighborhood-targeted and case-triggered use of a single dose of oral cholera vaccine in an urban setting: Feasibility and vaccine coverage.

Science.gov (United States)

Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Muller, Vincent; Llosa, Augusto E; Uzzeni, Florent; Luquero, Francisco J; Ciglenecki, Iza; Azman, Andrew S

2017-06-01

In June 2015, a cholera outbreak was declared in Juba, South Sudan. In addition to standard outbreak control measures, oral cholera vaccine (OCV) was proposed. As sufficient doses to cover the at-risk population were unavailable, a campaign using half the standard dosing regimen (one-dose) targeted high-risk neighborhoods and groups including neighbors of suspected cases. Here we report the operational details of this first public health use of a single-dose regimen of OCV and illustrate the feasibility of conducting highly targeted vaccination campaigns in an urban area. Neighborhoods of the city were prioritized for vaccination based on cumulative attack rates, active transmission and local knowledge of known cholera risk factors. OCV was offered to all persons older than 12 months at 20 fixed sites and to select groups, including neighbors of cholera cases after the main campaign ('case-triggered' interventions), through mobile teams. Vaccination coverage was estimated by multi-stage surveys using spatial sampling techniques. 162,377 individuals received a single-dose of OCV in the targeted neighborhoods. In these neighborhoods vaccine coverage was 68.8% (95% Confidence Interval (CI), 64.0-73.7) and was highest among children ages 5-14 years (90.0%, 95% CI 85.7-94.3), with adult men being less likely to be vaccinated than adult women (Relative Risk 0.81, 95% CI: 0.68-0.96). In the case-triggered interventions, each lasting 1-2 days, coverage varied (range: 30-87%) with an average of 51.0% (95% CI 41.7-60.3). Vaccine supply constraints and the complex realities where cholera outbreaks occur may warrant the use of flexible alternative vaccination strategies, including highly-targeted vaccination campaigns and single-dose regimens. We showed that such campaigns are feasible. Additional work is needed to understand how and when to use different strategies to best protect populations against epidemic cholera.

High-dose dosimetry using natural silicate minerals

International Nuclear Information System (INIS)

Carmo, Lucas S. do; Mendes, Leticia; Watanabe, Shigueo; Rao, Gundu; Lucas, Natasha; Sato, Karina; Barbosa, Renata F.

2015-01-01

In the present study, certain natural silicate minerals such as aquamarine (AB), morganite (PB), goshenite (WB), white jadeite (JW), green jadeite (JG), pink tourmaline (PT) and two varieties of jadeite-like quartz, denoted here by JQ1 and JQ2, were investigated using the thermoluminescence technique to evaluate their potential for use as very-high- and high-dose dosimeters. These minerals respond to high doses of γ-rays of up to 1000 kGy and often to very high doses of up to 3000 kGy. The TL response of these minerals may be considered to be satisfactory for applications in high-dose dosimetry. Investigations of electron paramagnetic resonance and optically stimulated luminescence dosimetry are in progress. (author)

High-dose dosimetry using natural silicate minerals

Energy Technology Data Exchange (ETDEWEB)

Carmo, Lucas S. do; Mendes, Leticia, E-mail: isatiro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Watanabe, Shigueo; Rao, Gundu; Lucas, Natasha; Sato, Karina, E-mail: lacifid@if.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica. Departamento de Fisica Nuclear; Barbosa, Renata F., E-mail: profcelta@hotmail.com [Universidade Federal de Sao Paulo (UNIFESP), Santos, SP (Brazil). Departamento de Ciencias do Mar

2015-07-01

In the present study, certain natural silicate minerals such as aquamarine (AB), morganite (PB), goshenite (WB), white jadeite (JW), green jadeite (JG), pink tourmaline (PT) and two varieties of jadeite-like quartz, denoted here by JQ1 and JQ2, were investigated using the thermoluminescence technique to evaluate their potential for use as very-high- and high-dose dosimeters. These minerals respond to high doses of γ-rays of up to 1000 kGy and often to very high doses of up to 3000 kGy. The TL response of these minerals may be considered to be satisfactory for applications in high-dose dosimetry. Investigations of electron paramagnetic resonance and optically stimulated luminescence dosimetry are in progress. (author)

Study on children patient dose in single-detector and multi-detector row helical computed tomography

International Nuclear Information System (INIS)

Lu Heqing; Zhu Guoying; Zhuo Weihai; Liu Haikuan; Guo Changyi

2008-01-01

Objective: To study and evaluate the radiation dose of children patient in single-detector and multi-detector row helical CT scan. Methods: The head and body CT dose index of 21 CT scanners were tested. Then the values of CTDI w , CTDI vol and DLP were calculated combining with the parameters of routine head and chest scan for children of 0-1 year old group, 5 years old group, 10 years old group and adults. The effective doses of children of every age group and adults in routine head and chest scan were subsequently estimated from effective dose per DLP by age and the calculated values of DLP. Results: CTDI per mAs is greater in the head than that in the body. In head routine scan, the effective doses of 0-1 year old group,5 years old group and 10 year old group were 2.2, 1.3 and 1.1 mSv, respectively. In chest routine scan, the effective doses of 0-1 year old group,5 years old group and 10 years old group were 5.3, 3.1 and 3.4 mSv, respectively. Effective doses to children per mAs are equally 1.8 times higher than corresponding values for adults. The CTDI vol , DLP and effective dose to children in head routine scan for MDCT were greater those that for single-detector CT and dual- detector CT. The CTDI vol , DLP and effective dose to children in chest routine scan for MDCT and dual-detector row CT were smaller than that for single-detector row CT. Conclusions: Children me more radiation risk in CT examination as compared with adults. So we should strictly abide by justification of children CT examination, and optimize the parameters of CT scan rationally in order to reduce the radiation dose to children patient as much as possible. (authors)

Effect of high dose irradiation on the red cell span in rabbits

International Nuclear Information System (INIS)

Kang, T.W.; Koh, J.W.; Woo, K.S.; Lee, O.H.; Youn, C.S.

1982-01-01

As a part of studies on acute effects of high dose irradiation in vivo, the present report was carried out to evaluate the changes of the red cell life span in the white rabbits by a single whole body exposure to gamma rays from 60 Co teletherapy unit. The exposure was done in dose levels of 100, 600 and 900 rads to each experimental group of 10 rabbits. The life span apparent half survival time of red cells, and that the red cell volume in the circulting blood were measured by ICSH Reference method using 51 Cr. (Author)

Disposition and metabolism of codeine after single and chronic doses in one poor and seven extensive metabolisers.

Science.gov (United States)

Chen, Z R; Somogyi, A A; Reynolds, G; Bochner, F

1991-04-01

1. The pharmacokinetics, metabolism and partial clearances of codeine to morphine, norcodeine and codeine-6-glucuronide after single (30 mg) and chronic (30 mg 8 h for seven doses) administration of codeine were studied in eight subjects (seven extensive and one poor metaboliser of dextromethorphan). Codeine, codeine-6-glucuronide, morphine and norcodeine were measured by high performance liquid chromatographic assays. 2. After the single dose, the time to achieve maximum plasma codeine concentrations was 0.97 +/- 0.31 h (mean +/- s.d.) and for codeine-6-glucuronide it was 1.28 +/- 0.49 h. The plasma AUC of codeine-6-glucuronide was 15.8 +/- 4.5 times higher than that of codeine. The AUC of codeine in saliva was 3.4 +/- 1.1 times higher than that in plasma. The elimination half-life of codeine was 3.2 +/- 0.3 h and that of codeine-6-glucuronide was 3.2 +/- 0.9 h. 3. The renal clearance of codeine was 183 +/- 59 ml min-1 and was inversely correlated with urine pH (r = 0.81). These data suggest that codeine undergoes filtration at the glomerulus, tubular secretion and passive reabsorption. The renal clearance of codeine-6-glucuronide was 55 +/- 21 ml min-1, and was not correlated with urine pH. Its binding to human plasma was less than 10%. These data suggest that codeine-6-glucuronide undergoes filtration at the glomerulus and tubular reabsorption. This latter process is unlikely to be passive. 4. After chronic dosing, the pharmacokinetics of codeine and codeine-6-glucuronide were not significantly different from the single dose pharmacokinetics. 5. After the single dose, 86.1 +/- 11.4% of the dose was recovered in urine, of which 59.8 +/- 10.3% was codeine-6-glucuronide, 7.1 +/- 1.1% was total morphine, 6.9 +/- 2.1% was total norcodeine and 11.8 +/- 3.9% was unchanged codeine. These recoveries were not significantly different (P greater than 0.05) after chronic administration. 6. After the single dose, the partial clearance to morphine was 137 +/- 31 ml min-1 in

Single daily dosing of antibiotics: importance of in vitro killing rate, serum half-life, and protein binding.

Science.gov (United States)

Potel, G; Chau, N P; Pangon, B; Fantin, B; Vallois, J M; Faurisson, F; Carbon, C

1991-10-01

The relative importance of pharmacokinetic and pharmacodynamic parameters for the feasibility of a single daily dose (SDD) of antibiotics remains to be established. Therefore, we studied the relationship between in vitro bacteriological parameters (MIC, MBC, and killing rate [KR], defined as the reduction in the inoculum within 3 h), pharmacokinetic parameters (t1/2 and protein binding [PB], and in vivo antibacterial effect of a single antibiotic dose in an experimental rabbit model of Escherichia coli endocarditis. Nine antibiotics were investigated: two aminoglycosides, two quinolones, and five beta-lactams. For each drug, the minimal effective dose (MED) (in milligrams per kilogram) was defined as the lowest dose able to achieve a significant difference (P less than 0.05) of CFU in the vegetations in comparison with controls 24 h after a single intravenous injection. Aminoglycosides and quinolones had the lowest MEDs, followed by beta-lactams. Univariate regression analysis showed that KR was the major determinant of MED. A stepwise regression analysis showed that t1/2 significantly improved the predictive value of KR, while PB, MIC, and MBC did not. The final equation was MED = 1,586-238 KR-297 t1/2 (r = 0.90, P = 0.01). We concluded that the pharmacodynamic parameters (especially the high KR) of aminoglycosides and quinolones explained their low MEDs and might allow SDD. In contrast, the low KR of beta-lactams emphasized the critical importance of a long t1/2, as for ceftriaxone, allowing the use of this beta-lactam alone in SDD.

Hit-size effectiveness theory applied to high doses of low LET radiation for pink mutations in Tradescantia

International Nuclear Information System (INIS)

Varma, M.N.; Bond, V.P.; Matthews, G.

1985-01-01

A hit-size effectiveness function which represents the probability of inducing a pink mutation in Tradescantia as a function of lineal energy density has been obtained (1) using observed pink mutation data for seven different radiation qualities and their respective single event microdosimetric spectra. In obtaining this function only the linear portions of dose-response curves were used. A significant improvement of the concepts embodied in the proposed hit-size effectiveness theory would be the demonstration of its applicability at high doses (where multiple hits are produced) and high dose rates (at which no significant biological repair takes place). In this article details are given on preliminary calculations of the pink mutation frequency in Tradescantia at 1, 5, 10, 20, and 60 rads for 250 kVp x rays, using the multi-hit spectra and the hit-size effectiveness function obtained on the basis of single hit microdosimetric spectra as outline in (1). A comparison of the calculated and observed pink mutation frequencies indicate excellent agreement and suggests the possibility of obtaining the hit-size effectiveness function from high dose biological-effect data obtained using low-LET radiations. 6 refs., 3 figs., 3 tabs

Acoustic neuromas: single dose vs fractionated therapy

Energy Technology Data Exchange (ETDEWEB)

Fuss, M; Debus, J; Lohr, F; Engenhart-Cabillic, R; Wannenmacher, M

1997-07-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

Single dose oral ketoprofen and dexketoprofen for acute postoperative pain in adults.

Science.gov (United States)

Barden, Jodie; Derry, Sheena; McQuay, Henry J; Moore, R Andrew

2009-10-07

Ketoprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID) used to treat acute and chronic painful conditions. Dexketoprofen is the (S)-enantiomer, which is believed to confer analgesia. Theoretically dexketoprofen is expected to provide equivalent analgesia to ketoprofen at half the dose, with a consequent reduction in gastrointestinal adverse events. To assess efficacy, duration of action, and associated adverse events of single dose oral ketoprofen and dexketoprofen in acute postoperative pain in adults. We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to August 2009. Randomised, double blind, placebo-controlled trials of single dose orally administered ketoprofen and dexketoprofen in adults with moderate to severe acute postoperative pain. Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected. Fourteen studies compared ketoprofen (968 participants) at mainly 25 mg and 50 mg with placebo (520 participants). Seven studies compared dexketoprofen (681 participants) at mainly 10 mg to 25 mg with placebo (289 participants). Studies were of adequate reporting quality, and participants had pain following dental, orthopaedic, obstetric, gynaecological and general surgery. There was considerable clinical heterogeneity between studies in dental and other types of surgery, particularly bunionectomy, which limited analysis.Ketoprofen at doses between 12.5 mg and 100 mg produced NNTs for at least 50% pain relief over 4 to 6

Method of thermoluminescent measurement of radiation doses from micrograys up to a megagray with a single LiF: Mg,Cu,P detector

International Nuclear Information System (INIS)

Obryk, B.; Bilski, P.; Olko, P.

2011-01-01

On the basis of the newly discovered behaviour of LiF:Mg,Cu,P detectors at high and ultra-high doses, a new method of thermoluminescence (TL) measurement of radiation doses ranging from micrograys up to a megagray, has been recently developed at the Inst. of Nuclear Physics (IFJ). The method is based on the relationship between the TL signal, integrated in the given temperature range and dose. It is quantified by a parameter called the 'ultra-high temperature ratio'. It has been demonstrated that this new method can measure radiation doses in the range of about 1 μGy to 1 MGy, using a single LiF:Mg,Cu,P detector. This method was recently successfully blindly tested for 10 MeV electrons up to doses of 200 kGy. It can be used for dosimetry in high-energy accelerators, especially in the Large Hadron Collider at CERN, and has great potential for accident dosimetry in particular. (authors)

Effect of propranolol in head tremor: quantitative study following single-dose and sustained drug administration.

Science.gov (United States)

Calzetti, S; Sasso, E; Negrotti, A; Baratti, M; Fava, R

1992-12-01

The effect of the beta-adrenoceptor antagonist propranolol has been investigated in nine patients suffering from isolated (six patients) or prominent (three patients) essential tremor of the head. In a double-blind, placebo-controlled study the tremorolytic efficacy of propranolol has been assessed by a quantitative accelerometric method after a single oral dose (120 mg) and following 2 weeks of sustained treatment with two different dosage regimens of the drug (120 and 240 mg daily). As compared with placebo, a significant reduction in tremor magnitude was found following a single oral dose but not on sustained administration of the beta-blocker at either dosage. The results suggest that the efficacy of sustained propranolol on isolated or prominent essential head tremor is less predictable and satisfactory than expected on the basis of the single-dose response, as compared with hand tremor.

Mouse single oral dose toxicity test of bupleuri radix aqueous extracts.

Science.gov (United States)

Kim, Kyung-Hu; Gam, Cheol-Ou; Choi, Seong-Hun; Ku, Sae-Kwang

2012-03-01

The aim of this study was to evaluate the single oral dose toxicity of Bupleuri Radix (BR) aqueous extracts, it has been traditionally used as anti-inflammatory agent, in male and female mice. BR extracts (yield = 16.52%) was administered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 14 principal organs were examined. As the results, no BR extracts treatment related mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations against 14 principal organs were detected up to 2,000 mg/kg in both female and male mice, except for soft feces and related body weight decrease detected in male mice treated with 2,000 mg/kg. Therefore, LD50 (50% lethal dose) and approximate LD of BR aqueous extracts after single oral treatment in female and male mice were considered over 2000 mg/kg, respectively. Although it was also observed that the possibilities of digestive disorders, like soft feces when administered over 2,000 mg/kg of BR extracts in the present study, these possibilities of digestive disorders can be disregard in clinical use because they are transient in the highest dosages male only.

The atypical excretion profile of meldonium: Comparison of urinary detection windows after single- and multiple-dose application in healthy volunteers.

Science.gov (United States)

Görgens, Christian; Guddat, Sven; Bosse, Christina; Geyer, Hans; Pop, Valentin; Schänzer, Wilhelm; Thevis, Mario

2017-05-10

Following a one-year monitoring program providing unequivocal analytical evidence for a high prevalence in international elite sports, meldonium has been included in the World Anti-Doping Agency's (WADA) list of prohibited substances that came into effect on 1 January 2016. Despite of the polar and hydrophilic nature of the molecule, an unusual long detection window was observed in pilot elimination studies. Consequently, in the present study, urinary excretion profiles after single-dose (5 volunteers, 1×500mg) and multiple-dose oral application (5 volunteers; 2×500mg/day for 6days) were determined in order to facilitate the result management concerning meldonium findings in doping controls. Particularly the option to differentiate between recent use and tapering concentrations was studied. Urinary meldonium concentrations were determined using an analytical approach based on hydrophilic interaction liquid chromatography and high resolution tandem mass spectrometry. The study corroborates the hypothesis of a non-linear, dose-depended and biphasic excretion profile after oral application of meldonium and demonstrates that urinary detection windows are of considerable extent with up to 65 and 117days (concentrations>LOQ of 10ng/mL) following single- and multiple-dose applications, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Pharmacokinetics of lansoprazole and its main metabolites after single and multiple intravenous doses in healthy Chinese subjects.

Science.gov (United States)

Zhang, Dan; Zhang, Yanan; Liu, Man; Wang, Xiaolin; Yang, Man; Han, Jing; Liu, Huichen

2013-09-01

The aim of the study was to evaluate and compare the pharmacokinetics of lansoprazole (LPZ) and its main metabolites, 5'-hydroxy lansoprazole (HLPZ) and lansoprazole sulfone (LPZS), after single and multiple intravenous (i.v.) doses of LPZ in healthy Chinese subjects. Twelve subjects (six males and six females) were given a single dose of LPZ by i.v. infusion on day 1, and multiple doses from day 2 to day 6. Blood samples were collected at designated time points for analysis of plasma concentrations of LPZ, HLPZ and LPZS by an LC-MS/MS method. LPZ was generally well tolerated in healthy Chinese subjects. After single and multiple i.v. doses of 30 mg LPZ, the C max values of LPZ, HLPZ and LPZS were 1490 ± 290 and 1450 ± 280, 175 ± 71 and 154 ± 56, and 51.3 ± 82.9 and 74.1 ± 158.7 ng/mL, with the AUC0-t values 3280 ± 2550 and 4260 ± 3880, 381 ± 128 and 389 ± 111, and 389 ± 1204 and 700 ± 2255 ng h/mL, respectively. The t 1/2 and CL values of LPZ after single and multiple i.v. doses were 1.48 ± 1.03 and 2.19 ± 1.03 h, and 11.67 ± 4.49 and 9.56 ± 4.08 L/h, respectively. Compared with the pharmacokinetics of LPZ after a single dose, t 1/2 increased markedly, CL decreased significantly and AUC increased by over 20 % after multiple doses. The results indicated that there was drug accumulation of LPZ after multiple i.v. doses, and there was no gender-related difference in pharmacokinetics of LPZ and its two metabolites.

Relative safety profiles of high dose statin regimens

Directory of Open Access Journals (Sweden)

Carlos Escobar

2008-06-01

Full Text Available Carlos Escobar, Rocio Echarri, Vivencio BarriosDepartment of Cardiology, Hospital Ramón y Cajal, Madrid, SpainAbstract: Recent clinical trials recommend achieving a low-density lipoprotein cholesterol level of <100 mg/dl in high-risk and <70 mg/dl in very high risk patients. To attain these goals, however, many patients will need statins at high doses. The most frequent side effects related to the use of statins, myopathy, rhabdomyolysis, and increased levels of transaminases, are unusual. Although low and moderate doses show a favourable profile, there is concern about the tolerability of higher doses. During recent years, numerous trials to analyze the efficacy and tolerability of high doses of statins have been published. This paper updates the published data on the safety of statins at high doses.Keywords: statins, high doses, tolerability, liver, muscle

A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles.

Science.gov (United States)

Kurosawa, Yuko; Nirengi, Shinsuke; Homma, Toshiyuki; Esaki, Kazuki; Ohta, Mitsuhiro; Clark, Joseph F; Hamaoka, Takafumi

2015-06-25

Our aim was to determine the quantitative effects of a single-dose of Nattokinase (NK) administration on coagulation/fibrinolysis parameters comprehensively in healthy male subjects. A double-blind, placebo-controlled cross-over NK intervention study was carried out in 12 healthy young males. Following the baseline blood draw, each subject was randomized to receive either a single-dose of 2,000 FU NK (NSK-SD, Japan Bio Science Laboratory Co., Ltd) or placebo with subsequent cross-over of the groups. Subjects donated blood samples at 2, 4, 6 and 8 hours following administration for analysis of coagulation/fibrinolysis parameters. As a result, D-dimer concentrations at 6, and 8 hours, and blood fibrin/fibrinogen degradation products at 4 hours after NK administration elevated significantly (p < 0.05, respectively). Factor VIII activity declined at 4 and 6 hours (p < 0.05, respectively), blood antithrombin concentration was higher at 2 and 4 hours (p < 0.05, respectively), and the activated partial thromboplastin time prolonged significantly at 2 and 4 hours following NK administration (p < 0.05 and p < 0.01, respectively). All the changes, however, were within the normal range. In conclusion, thus, a single-dose of NK administration appears enhancing fibrinolysis and anti-coagulation via several different pathways simultaneously.

Comparative pharmacokinetics of oxytetracycline in blunt-snout bream (Megalobrama amblycephala) with single and multiple-dose oral administration.

Science.gov (United States)

Li, Ru-Qin; Ren, Yu-Wei; Li, Jing; Huang, Can; Shao, Jun-Hui; Chen, Xiao-Xuan; Wu, Zhi-Xin

2015-06-01

Research into the pharmacokinetics and residue elimination of oxytetracycline (OTC) is important both to determine the optimal dosage regimens and to establish a safe withdrawal time in fish. A depletion study is presented here for OTC in Megalobrama amblycephala with a single-dose (100 mg/kg) and multiple-dose (100 mg/kg for five consecutive days) oral administration. The study was conducted at 25 °C. As a result, a one-compartment model was developed. For the single dose, the absorption half-life was 5.79, 9.40, 6.96, and 8.06 h in the plasma, liver, kidney, and muscle, respectively. However, the absorption half-life was 3.62, 7.33, 4.59, and 6.02 h with multiple-dose oral administration. The elimination half-time in the plasma, liver, kidney, and muscle was 58.63, 126.43, 65.1, and 58.85 h when M. amblycephala was treated with a single dose. However, the elimination half-time changed to 91.75, 214.87, 126.22, and 135.84 h with multiple-dose oral administration.

Incorporating single-side sparing in models for predicting parotid dose sparing in head and neck IMRT

International Nuclear Information System (INIS)

Yuan, Lulin; Wu, Q. Jackie; Yin, Fang-Fang; Yoo, David; Jiang, Yuliang; Ge, Yaorong

2014-01-01

Purpose: Sparing of single-side parotid gland is a common practice in head-and-neck (HN) intensity modulated radiation therapy (IMRT) planning. It is a special case of dose sparing tradeoff between different organs-at-risk. The authors describe an improved mathematical model for predicting achievable dose sparing in parotid glands in HN IMRT planning that incorporates single-side sparing considerations based on patient anatomy and learning from prior plan data. Methods: Among 68 HN cases analyzed retrospectively, 35 cases had physician prescribed single-side parotid sparing preferences. The single-side sparing model was trained with cases which had single-side sparing preferences, while the standard model was trained with the remainder of cases. A receiver operating characteristics (ROC) analysis was performed to determine the best criterion that separates the two case groups using the physician's single-side sparing prescription as ground truth. The final predictive model (combined model) takes into account the single-side sparing by switching between the standard and single-side sparing models according to the single-side sparing criterion. The models were tested with 20 additional cases. The significance of the improvement of prediction accuracy by the combined model over the standard model was evaluated using the Wilcoxon rank-sum test. Results: Using the ROC analysis, the best single-side sparing criterion is (1) the predicted median dose of one parotid is higher than 24 Gy; and (2) that of the other is higher than 7 Gy. This criterion gives a true positive rate of 0.82 and a false positive rate of 0.19, respectively. For the bilateral sparing cases, the combined and the standard models performed equally well, with the median of the prediction errors for parotid median dose being 0.34 Gy by both models (p = 0.81). For the single-side sparing cases, the standard model overestimates the median dose by 7.8 Gy on average, while the predictions by the combined

Pharmacokinetics and Safety of Intravenous Murepavadin Infusion in Healthy Adult Subjects Administered Single and Multiple Ascending Doses.

Science.gov (United States)

Wach, Achim; Dembowsky, Klaus; Dale, Glenn E

2018-04-01

Murepavadin is the first in class of the outer membrane protein-targeting antibiotics (OMPTA) and a pathogen-specific peptidomimetic antibacterial with a novel, nonlytic mechanism of action targeting Pseudomonas aeruginosa Murepavadin is being developed for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP). The pharmacokinetics (PK) and safety of single and multiple doses of murepavadin were investigated in healthy male subjects. Part A of the study was a double-blind, randomized, placebo-controlled, single-ascending-dose investigation in 10 sequential cohorts where each cohort comprised 6 healthy male subjects; 4 subjects were randomized to murepavadin, and 2 subjects were randomized to placebo. Part B was a double-blind, randomized, placebo-controlled, multiple-ascending-dose investigation in 3 sequential cohorts. After a single dose of murepavadin, the geometric mean half-life (2.52 to 5.30 h), the total clearance (80.1 to 114 ml/h/kg), and the volume of distribution (415 to 724 ml/kg) were consistent across dose levels. The pharmacokinetics of the dosing regimens evaluated were dose proportional and linear. Murepavadin was well tolerated, adverse events were transient and generally mild, and no dose-limiting toxicity was identified. Copyright © 2018 American Society for Microbiology.

Determination of burial dose in incompletely bleached fluvial samples using single grains of quartz

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, Lars

2007-01-01

We determine the burial dose in three known-age incompletely bleached fluvial samples using single grains of quartz. Estimation of burial dose in incompletely bleached samples requires that the characteristics of the well-bleached part of the distribution are known in order to distinguish between...... well-bleached and poorly bleached grains. It is especially important to investigate if the uncertainties assigned to individual estimates of dose adequately describe the observed variability in well-bleached dose distributions. We investigate this by quantifying the overdispersion in laboratory-bleached...

Single Low Dose Primaquine (0.25 mg/kg Does Not Cause Clinically Significant Haemolysis in G6PD Deficient Subjects.

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Germana Bancone

Full Text Available Primaquine is the only drug consistently effective against mature gametocytes of Plasmodium falciparum. The transmission blocking dose of primaquine previously recommended was 0.75 mg/kg (adult dose 45 mg but its deployment was limited because of concerns over haemolytic effects in patients with glucose-6-phosphate dehydrogenase (G6PD deficiency. G6PD deficiency is an inherited X-linked enzymatic defect that affects an estimated 400 million people around the world with high frequencies (15-20% in populations living in malarious areas. To reduce transmission in low transmission settings and facilitate elimination of P. falciparum, the World Health Organization now recommends adding a single dose of 0.25 mg/kg (adult dose 15 mg to Artemisinin-based Combination Therapies (ACTs without G6PD testing. Direct evidence of the safety of this low dose is lacking. Adverse events and haemoglobin variations after this treatment were assessed in both G6PD normal and deficient subjects in the context of targeted malaria elimination in a malaria endemic area on the North-Western Myanmar-Thailand border where prevalence of G6PD deficiency (Mahidol variant approximates 15%.The tolerability and safety of primaquine (single dose 0.25 mg base/kg combined with dihydroartemisinin-piperaquine (DHA-PPQ given three times at monthly intervals was assessed in 819 subjects. Haemoglobin concentrations were estimated over the six months preceding the ACT + primaquine rounds of mass drug administration. G6PD deficiency was assessed with a phenotypic test and genotyping was performed in male subjects with deficient phenotypes and in all females. Fractional haemoglobin changes in relation to G6PD phenotype and genotype and primaquine round were assessed using linear mixed-effects models. No adverse events related to primaquine were reported during the trial. Mean fractional haemoglobin changes after each primaquine treatment in G6PD deficient subjects (-5.0%, -4.2% and -4

Efficacy of praziquantel against Schistosoma mekongi and Opisthorchis viverrini: a randomized, single-blinded dose-comparison trial.

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Leonore Lovis

Full Text Available BACKGROUND: Schistosomiasis and opisthorchiasis are of public health importance in Southeast Asia. Praziquantel (PZQ is the drug of choice for morbidity control but few dose comparisons have been made. METHODOLOGY: Ninety-three schoolchildren were enrolled in an area of Lao PDR where Schistosoma mekongi and Opisthorchis viverrini coexist for a PZQ dose-comparison trial. Prevalence and intensity of infections were determined by a rigorous diagnostic effort (3 stool specimens, each examined with triplicate Kato-Katz before and 28-30 days after treatment. Ninety children with full baseline data were randomized to receive PZQ: the 40 mg/kg standard single dose (n = 45 or a 75 mg/kg total dose (50 mg/kg+25 mg/kg, 4 hours apart; n = 45. Adverse events were assessed at 3 and 24 hours posttreatment. PRINCIPAL FINDINGS: Baseline infection prevalence of S. mekongi and O. viverrini were 87.8% and 98.9%, respectively. S. mekongi cure rates were 75.0% (95% confidence interval (CI: 56.6-88.5% and 80.8% (95% CI: 60.6-93.4% for 40 mg/kg and 75 mg/kg PZQ, respectively (P = 0.60. O. viverrini cure rates were significantly different at 71.4% (95% CI: 53.4-84.4% and 96.6% (95% CI: not defined, respectively (P = 0.009. Egg reduction rates (ERRs against O. viverrini were very high for both doses (>99%, but slightly lower for S. mekongi at 40 mg/kg (96.4% vs. 98.1% and not influenced by increasing diagnostic effort. O. viverrini cure rates would have been overestimated and no statistical difference between doses found if efficacy was based on a minimum sampling effort (single Kato-Katz before and after treatment. Adverse events were common (96%, mainly mild with no significant differences between the two treatment groups. CONCLUSIONS/SIGNIFICANCE: Cure rate from the 75 mg/kg PZQ dose was more efficacious than 40 mg/kg against O. viverrini but not against S. mekongi infections, while ERRs were similar for both doses. TRIAL REGISTRATION: Controlled

Single-Dose Universal Hepatitis A Immunization in Argentina: Low Viral Circulation and High Persistence of Protective Antibodies Up to 4 Years.

Science.gov (United States)

Vizzotti, C; González, J; Rearte, A; Urueña, A; Pérez Carrega, M; Calli, R; Gentile, A; Uboldi, A; Ramonet, M; Cañero-Velasco, M; Diosque, M

2015-12-01

Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children aged 12 months in 2005. Between 2005 and 2011, a dramatic decline was observed in HAV infection rates, fulminant hepatitis, and liver transplantation. This study assessed current viral circulation and estimated protective antibody persistence 4 years after vaccination. Prevalence of prevaccination anti-HAV antibodies in 12-month-old children was evaluated as an indirect estimation of viral circulation (Group A). Seroprevalence was also measured in 5-year-old children who received 1 dose of HAV vaccine at 1 year of age (Group B). Blood samples were tested for immunoglobulin (Ig)G anti-HAV antibodies (seroprotection = ≥10 mIU/mL). All Group A-positive samples were tested for IgM anti-HAV antibodies to identify recent infections. Logistic regression analysis was done to evaluate associations between demographic and socioeconomic variables and seroprotection. Of 433 children from Group A, 29.5% (95% confidence interval [CI], 25.2-33.8) were positive for IgG anti-HAV antibodies with a geometric mean concentration (GMC) of 6.17 mIU/mL (95% CI, 5.33-7.15 mIU/mL); all IgM anti-HAV were negative. From 1139 in Group B, 93% (95% CI, 91.7-94.6) maintained seroprotection with a GMC of 97.96 mIU/mL (95% CI, 89.21-107.57 mIU/mL). Kindergarten attendance was associated with seroprotection in Group B (odds ratio [OR], 2.0; 95% CI, 1.26-3.3). In contrast, high maternal educational level was associated with a lack of seroprotection in this group (OR, .26; 95% CI, .09-.8). Single-dose, universal hepatitis A immunization in infants resulted in low HAV circulation and persistent immunologic protection up to 4 years in Argentina. Variables associated with presence or absence of seroprotection in vaccinated children could be related to differences in hygiene habits in settings with residual viral circulation. © The Author 2014. Published by Oxford University Press on behalf of the Pediatric

Effects of single doses of X-rays on renal function in the pig after the irradiation of both kidneys

International Nuclear Information System (INIS)

Robbins, M.E.C.; Hopewell, J.W.

1988-01-01

Irradiation of a single kidney in the pig with relatively low doses of X-rays, in the order of 8 Gy, produces a pronounced reduction in both glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). This apparent high radiosensitivity may be due, in part, to the compensatory hypertrophy displayed by the contralateral unirradiated kidney. This could suppress any potential for recovery by the irradiated kidney. To test this hypothesis, both kidneys of 14-week-old Large White pigs were sequentially irradiated with single doses of 250 kV X-rays, in the range 8.8 to 12.6 Gy. Two weeks after irradiation, GFR and ERPF increased markedly in all irradiated kidneys; levels then declined in a dose-dependent manner. Following a dose of 8.8 Gy renal haemodynamics returned to control values within 4 weeks of irradiation. After higher doses, GFR and ERPF decreased markedly and remained below control values up to 24 weeks after irradiation. At all doses the mean functional status of irradiated kidneys in animals in which both kidneys were irradiated was significantly greater than that previously observed in the irradiated kidney of pigs in which only one kidney was irradiated. The findings support the above hypothesis, and indicate that individual kidneys in the same animal may differ in their response to a similar nephrotoxic insult. 35 refs.; 6 figs.; 2 tabs

Development of miniature γ dose rate monitor with high sensitivity

International Nuclear Information System (INIS)

Shi Huilu; Tuo Xianguo; Xi Dashun; Tang Rong; Mu Keliang; Yang Jianbo

2009-01-01

This paper introduces a miniature γ dose rate monitor with high sensitivity which design based on single chip microcomputer, it can continue monitoring γ dose rate and then choose wire or wireless communications to sent the monitoring data to host according to the actual conditions. It has two kinds of power supply system, AC power supply system and battery which can be chose by concrete circumstances. The design idea and implementation technology of hardware and software and the system structure of the monitor are detailed illustrated in this paper. The experimental results show that measurable range is 0.1 mR/h-200 mR/h, the sensitivity of γ is 90 cps/mR/h, dead time below 200 us, error of stability below ±10%. (authors)

High dose rate versus medium dose rate intraluminal brachytherapy in inoperable esophageal carcinoma

International Nuclear Information System (INIS)

Langendijk, J.; Jager, J.; Jong, J. de; Rijken, J.; Pannebakker, M.

1996-01-01

Introduction: The purpose of this study was to compare the results of medium dose rate (MDR) intraluminal brachytherapy (ILBT) and high dose rate (HDR) ILBT in patients with inoperable esophageal carcinoma, with regard to dysphagia, complication rate and survival. Material and methods: Included were 114 patients with inoperable esophageal cancer who were treated with a single session of ILBT. In all cases a single dose of 15 Gy was administered, calculated at a 1 cm radius. Forty-eight patients were treated with MDR ( 137 Cs)ILBT. In June 1990 MDR was replaced by HDR and from then 66 patients were treated with HDR ( 192 Ir). Dysphagia was prospectively scored using a 5-point scale at 6 weeks, 3, 6, 9 and 12 months. Results: No significant differences were noted between the two groups with regard to pretreatment variables. In patients treated with MDR-ILBT improvement of swallowing ability was noted in 30 out of 42 evaluable patients (71%), no change in 9 (21%) and progression of dysphagia in 3 patients (8%), as compared to 34 out of 59 evaluable patients (58%), 16 (27%) and 6 (15%) resp. in de HDR-ILBT group. In the latter category, progression of dysphagia was caused by fistulae in 2 patients. The differences were not significant (ns). Additional treatment in case of recurrent or persistent dysphagia was needed in 50% of the cases in the MDR-ILBT group as compared to 41% in the HDR-ILBT group (ns). The median survival of the MDR-ILBT group was 3.9 months as compared to 4.3 months in the HDR-ILBT group (ns). In 2 patients (4%) treated with MDR-ILBT bronchio-oesphageal fistulae developed at 6 weeks and 2 months. In the HDR-ILBT group fistulae were noted in 7 cases (11%) at 2 weeks, 4 weeks, 2, 3, 3, 4 and 9 months (ns). In all of these cases persistent of recurrent tumour was present. Conclusions: No significant differences were noted with regard to palliation of dysphagia, survival and complication rate between MDR-ILBT and HDR-ILBT in the management of esophageal

Single dose planning for radioiodine-131 therapy of Graves' disease

International Nuclear Information System (INIS)

Kita, Tamotsu; Yokoyama, Kunihiko; Kinuya, Seigo; Taki, Junichi; Michigishi, Takatoshi; Tonami, Norihisa

2004-01-01

Patients with Graves' disease were studied one year after radioiodine-131 therapy to assess the relationship between the effectiveness of the therapy and the radioiodine doses used. Patients were classified into three groups according to thyroid function as hyperthyroidism, euthyroidism and hypothyroidism at one year after I-131 therapy. In these groups we compared the mean values of dose, dose per thyroid weight calculated with I-123 uptake before the therapy (pre D/W), dose per thyroid weight calculated with therapeutic I-131 uptake (post D/W), and absorbed dose. No significant differences were found between the three groups in terms of dose or pre D/W. The mean values of post D/W and absorbed dose in the non-hyperthyroid (euthyroid and hypothyroid) group were significantly greater than those in the hyperthyroid group. Post D/W of 6.3 MBq/g was a threshold separating the non-hyperthyroid group from the hyperthyroid group. There was no correlation between pre D/W and post D/W; however, the mean post D/W was significantly greater than the mean pre D/W. All patients with pre D/W above 6.3 MBq/g showed non-hyperthyroidism at one year after the radioiodine treatment. No indicators before the radioiodine therapy had significant relationships with the effectiveness of the therapy at one year after the treatment. However, the single therapy planned for setting the pre D/W above 6.3 MBq/g will certainly make the patients non-hyperthyroid. As this proposal of dose planning is based on a small number of patients, further study is needed. (author)

High dose gamma-ray standard

International Nuclear Information System (INIS)

Macrin, R.; Moraru, R.

1999-01-01

The high gamma-ray doses produced in a gamma irradiator are used, mainly, for radiation processing, i.e. sterilization of medical products, processing of food, modifications of polymers, irradiation of electronic devices, a.s.o. The used absorbed doses depend on the application and cover the range 10 Gy to 100 MGy. The regulations in our country require that the response of the dosimetry systems, used for the irradiation of food and medical products, be calibrated and traceable to the national standards. In order to be sure that the products receive the desired absorbed dose, appropriate dosimetric measurements must be performed, including the calibration of the dosemeters and their traceability to the national standards. The high dose gamma-ray measurements are predominantly based on the use of reference radiochemical dosemeters. Among them the ferrous sulfate can be used as reference dosemeter for low doses (up to 400 Gy) but due to its characteristics it deserves to be considered a standard dosemeter and to be used for transferring the conventional absorbed dose to other chemical dosemeters used for absorbed doses up to 100 MGy. The study of the ferrous sulfate dosemeter consisted in preparing many batches of solution by different operators in quality assurance conditions and in determining for all batches the linearity, the relative intrinsic error, the repeatability and the reproducibility. The principal results are the following: the linear regression coefficient: 0.999, the relative intrinsic error: max.6 %, the repeatability (for P* = 95 %): max.3 %, the reproducibility (P* = 95%): max.5 %. (authors)

Extreme implanting in Si: A study of ion-induced damage at high temperature and high dose

International Nuclear Information System (INIS)

Holland, O.W.

1994-01-01

Ion-solid interactions near room temperature and below have been well studied in single-crystal Si. While this has led to a better understanding of the mechanisms responsible for nucleation and growth of lattice damage during irradiation, these studies have not, in general, been extended to high temperatures (e.g., >200 degrees C). This is the case despite the commercialization of ion beam technologies which utilize high-temperature processing, such as separation by implantation of oxygen (SIMOX). In this process, a silicon-on-insulator (SOI) material is produced by implanting a high dose of oxygen ions into a Si wafer to form a buried, stoichiometric oxide layer. Results will be presented of a study of damage accumulation during high-dose implantation of Si at elevated temperatures. In particular, O + -ions were used because of the potential impact of the results on the SIMOX technology. It will be shown that the nature of the damage accumulation at elevated temperatures is quite distinctive and portends the presence of a new mechanism, one which is only dominant under the extreme conditions encountered during ion beam synthesis (i.e., high temperature and high dose). This mechanism is discussed and shown to be quite general and not dependent on the chemical identity of the ions. Also, techniques for suppressing this mechanism by open-quotes defect engineeringclose quotes are discussed. Such techniques are technologically relevant because they offer the possibility of reducing the defect density of the SOI produced by SIMOX

Accuracy in radiosurgery: The influence of collimator diameters and arc weights on the dose distribution for single target

Energy Technology Data Exchange (ETDEWEB)

Plazas, M S [National Univ. of Colombia (Colombia); Lefkopoulus, D; Schlienger, M [Service de Radiotherapie, Hopital Tenon, Paris (France). Unite de Radiophysique; Merienne, L [Hopital Sainte Anne, Paris (France). Service de Neurochirurgie

1996-08-01

The dosimetric characteristics of mini-beams and dose distributions in beams used for radio surgery defer substantially from beams used in common radiotherapy. The aim of radio surgery is to deliver a high dose to the lesion in one single fraction, while minimizing the dose delivered to the surrounding normal brain tissue. This type of irradiation is performed with a number of continuous arcs located in various corneal (patient sitting) or sagittal (patient in a supine position) inclined planes using a linear accelerator. A treatment planning system should take into account a large number of irradiation parameters such as the collimator diameter, number of arcs, their angular positions, length and weight of the arcs. We analysed the influence of collimator diameters in the range of 6 to 20 mm using 15 MV X-rays and stereo-tactic irradiation of ellipsoidal inclined arterio venous malformations (AVMs) with a single isocenter. Special arc weights were used to obtain an optimized dose distribution with 13 arcs distributed over an angular sector of 120 deg. x 13 deg. In the two studies made we used 3 dimensional dosimetric calculations. The results were used for the treatment of patients and enabled the choice of the optimal irradiation configuration for each patient. (author). 10 refs, 9 figs.

Absorption, Distribution, and Excretion of 14C-APX001 after Single-Dose Administration to Rats and Monkeys

OpenAIRE

Mansbach, Robert; Shaw, Karen J; Hodges, Michael R; Coleman, Samantha; Fitzsimmons, Michael E

2017-01-01

Abstract Background APX001 is a small-molecule therapeutic agent in clinical development for the treatment of invasive fungal infections (IFI). Methods The absorption, distribution and excretion profiles of [14C]APX001-derived radioactivity were determined in rats (albino and pigmented) and monkeys. Rats (some implanted with bile duct cannulae) were administered a single 100 mg/kg oral dose or a 30 mg/kg intravenous (IV) dose. Monkeys were administered a single 6 mg/kg IV dose. Samples of blo...

Improved metabolic control in tetrahydrobiopterin (BH4), responsive phenylketonuria with sapropterin administered in two divided doses vs. a single daily dose.

Science.gov (United States)

Kör, Deniz; Yılmaz, Berna Şeker; Bulut, Fatma Derya; Ceylaner, Serdar; Mungan, Neslihan Önenli

2017-07-26

Phenylketonuria (PKU) often requires a lifelong phenylalanine (Phe)-restricted diet. Introduction of 6R-tetrahydrobiopterin (BH4) has made a huge difference in the diets of patients with PKU. BH4 is the co-factor of the enzyme phenylalanine hydroxylase (PAH) and improves PAH activity and, thus, Phe tolerance in the diet. A limited number of published studies suggest a pharmacodynamic profile of BH4 more suitable to be administered in divided daily doses. After a 72-h BH4 loading test, sapropterin was initiated in 50 responsive patients. This case-control study was conducted by administering the same daily dose of sapropterin in group 1 (n=24) as a customary single dose or in two divided doses in group 2 (n=26) over 1 year. Mean daily consumption of Phe increased significantly after the first year of BH4 treatment in group 2 compared to group 1 (p<0.05). At the end of the first year of treatment with BH4, another dramatic difference observed between the two groups was the ability to transition to a Phe-free diet. Eight patients from group 2 and two from group 1 could quit dietary restriction. When given in two divided daily doses, BH4 was more efficacious than a single daily dose in increasing daily Phe consumption, Phe tolerance and the ability to transition to a Phe-unrestricted diet at the end of the first year of treatment.

Single dose of fluoxetine increases muscle activation in chronic stroke patients.

NARCIS (Netherlands)

van Genderen, Hanneke Irene; Nijlant, Juliette M.M.; van Putten, Michel Johannes Antonius Maria; Movig, Kris L.L.; IJzerman, Maarten Joost

2009-01-01

Objectives: This pilot study explores the influence of a single dose of fluoxetine (20 mg) on the muscle activation patterns and functional ability of the muscles in the lower part of the arm in chronic stroke patients. Methods: A crossover, placebo-controlled clinical trial was conducted in 10

Estimation of the transit dose component in high dose rate brachytherapy

International Nuclear Information System (INIS)

Garcia Romero, A.; Millan Cebrian, E.; Lozano Flores, F.J.; Lope Lope, R.; Canellas Anoz, M.

2001-01-01

Current high dose rate brachytherapy (HDR) treatment planning systems usually calculate dose only from source stopping positions (stationary component), but fails to account for the administered dose when the source is moving (dynamic component or transit dose). Numerical values of this transit dose depends upon the source velocity, implant geometry, source activity and prescribed dose. In some HDR treatments using particular geometry the transit dose cannot be ignored because it increases the dose at the prescriptions points and also could increase potential late tissue complications as predicted by the linear quadratic model. International protocols recommend to verify this parameter. The aim of this paper has been to establish a procedure for the transit dose calculation for the Gammamed 12i equipment at the RT Department in the Clinical University Hospital (Zaragoza-Spain). A numeric algorithm was implemented based on a dynamic point approximation for the moving HDR source and the calculated results for the entrance-exit transit dose was compared with TLD measurements made in some discrete points. (author) [es

Single dose oral piroxicam for acute postoperative pain

Science.gov (United States)

Moore, R Andrew; Edwards, Jayne; Loke, Yoon; Derry, Sheena; McQuay, Henry J

2014-01-01

Background This is an updated version of the original Cochrane review published in Issue 2, 2000. Piroxicam is a non-steroidal anti-inflammatory drug (NSAID) with analgesic properties, and is used mainly for treating rheumatic disorders. Some drugs have been directly compared against each other within a trial setting to determine their relative efficacies, whereas other have not. It is possible, however, to compare analgesics indirectly by examining the effectiveness of each drug against placebo when used in similar clinical situations. Objectives To determine the analgesic efficacy and adverse effects of single-dose piroxicam compared with placebo in moderate to severe postoperative pain. To compare the effects of piroxicam with other analgesics. Search methods Published studies were identified from systematic searching of MEDLINE, Biological Abstracts, EMBASE, CENTRAL and the Oxford Pain Relief Database in December 2007. Additional studies were identified from the reference lists of retrieved reports. Selection criteria The following inclusion criteria were used: full journal publication, randomised placebo controlled trial, double-blind design, adult participants, postoperative pain of moderate to severe intensity at the baseline assessment, postoperative administration of oral or intramuscular piroxicam. Data collection and analysis Summed pain intensity and pain relief data were extracted and converted into dichotomous information to yield the number of participants obtaining at least 50% pain relief. This was used to calculate estimates of relative benefit and number-needed-to-treat-to-benefit (NNT) for one participant to obtain at least 50% pain relief. Information was collected on adverse effects and estimates of relative risk and number-needed-to-treat-to-harm (NNH) were calculated. Main results In this update no further studies were found. The original search identified three studies (141 participants) which compared oral piroxicam 20 mg with placebo and

Clinical trial: single- and multiple-dose pharmacokinetics of polyethylene glycol (PEG-3350) in healthy young and elderly subjects.

Science.gov (United States)

Pelham, R W; Nix, L C; Chavira, R E; Cleveland, M Vb; Stetson, P

2008-07-01

The pharmacokinetics of polyethylene glycol 3350 (PEG-3350) have not been fully described because of lack of a sufficiently sensitive analytical method. To describe the pharmacokinetics of PEG-3350 in humans. A highly sensitive, high performance liquid chromatography with mass spectrometry (HPLC/MS/MS) method was developed for PEG-3350 in urine, plasma and faeces with quantification limits of 30 ng/mL, 100 ng/mL and 500 microg/g respectively. Noncompartmental pharmacokinetics methods were used and the effects of gender, age, renal status and dosing frequency were examined after the oral administration of 17 g to healthy volunteers. Peak PEG-3350 plasma concentrations occurred at 2-4 h and declined to nonquantifiable levels usually within 18 h after single and multiple doses, with a half-life of about 4-6 h. Steady state was reached within 5 days of dosing. Mean urinary excretion of the administered dose ranged from 0.19% to 0.25%. Age, gender or mild kidney impairment did not alter the pharmacokinetics of PEG-3350. Mean faecal excretion of the administered dose was 93% in young subjects. For the first time, a highly sensitive assay allowed comprehensive pharmacokinetics studies of PEG-3350 in humans. These studies confirmed that orally administered PEG-3350 is minimally absorbed, rapidly excreted and primarily eliminated via faeces.

ELDRS Characterization for a Very High Dose Mission

Science.gov (United States)

Harris, Richard D.; McClure, Steven S.; Rax, Bernard G.; Kenna, Aaron J.; Thorbourn, Dennis O.; Clark, Karla B.; Yan, Tsun-Yee

2010-01-01

Evaluation of bipolar linear parts which may have Enhanced Low Dose Rate Sensitivity (ELDRS) is problematic for missions that have very high dose radiation requirements. The accepted standards for evaluating parts that display ELDRS require testing at a very low dose rate which could be prohibitively long for very high dose missions. In this work, a methodology for ELDRS characterization of bipolar parts for mission doses up to 1 Mrad(Si) is evaluated. The procedure employs an initial dose rate of 0.01 rad(Si)/s to a total dose of 50 krad(Si) and then changes to 0.04 rad(Si)/s to a total dose of 1 Mrad(Si). This procedure appears to work well. No change in rate of degradation with dose has been observed when the dose rate is changed from 0.01 to 0.04 rad(Si)/s. This is taken as an indication that the degradation due to the higher dose rate is equivalent to that at the lower dose rate at the higher dose levels, at least for the parts studied to date. In several cases, significant parameter degradation or functional failure not observed at HDR was observed at fairly high total doses (50 to 250 krad(Si)) at LDR. This behavior calls into question the use of dose rate trend data and enhancement factors to predict LDR performance.

Compendium of Single Event Effects, Total Ionizing Dose, and Displacement Damage for Candidate Spacecraft Electronics for NASA

Science.gov (United States)

LaBel, Kenneth A.; OBryan, Martha V.; Chen, Dakai; Campola, Michael J.; Casey, Megan C.; Pellish, Jonathan A.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Ladbury, Raymond L.;

High-Dose, Single-Fraction Irradiation Rapidly Reduces Tumor Vasculature and Perfusion in a Xenograft Model of Neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Jani, Ashish; Shaikh, Fauzia; Barton, Sunjay [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States); Willis, Callen [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Banerjee, Debarshi [Department of Pediatrics, Columbia University Medical Center, New York, New York (United States); Mitchell, Jason [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Hernandez, Sonia L. [Department of Surgery, University of Chicago, Chicago, Illinois (United States); Hei, Tom [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States); Kadenhe-Chiweshe, Angela [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Yamashiro, Darrell J. [Department of Surgery, Columbia University Medical Center, New York, New York (United States); Department of Pediatrics, Columbia University Medical Center, New York, New York (United States); Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York (United States); Connolly, Eileen P., E-mail: epc2116@cumc.columbia.edu [Department of Radiation Oncology, Columbia University Medical Center, New York, New York (United States)

2016-04-01

Purpose: To characterize the effects of high-dose radiation therapy (HDRT) on neuroblastoma tumor vasculature, including the endothelial cell (EC)–pericyte interaction as a potential target for combined treatment with antiangiogenic agents. Methods and Materials: The vascular effects of radiation therapy were examined in a xenograft model of high-risk neuroblastoma. In vivo 3-dimensional contrast-enhanced ultrasonography (3D-CEUS) imaging and immunohistochemistry (IHC) were performed. Results: HDRT significantly reduced tumor blood volume 6 hours after irradiation compared with the lower doses used in conventionally fractionated radiation. There was a 63% decrease in tumor blood volume after 12-Gy radiation compared with a 24% decrease after 2 Gy. Analysis of tumor vasculature by lectin angiography showed a significant loss of small vessel ends at 6 hours. IHC revealed a significant loss of ECs at 6 and 72 hours after HDRT, with an accompanying loss of immature and mature pericytes at 72 hours. Conclusions: HDRT affects tumor vasculature in a manner not observed at lower doses. The main observation was an early reduction in tumor perfusion resulting from a reduction of small vessel ends with a corresponding loss of endothelial cells and pericytes.

High-dose-rate interstitial brachytherapy for the treatment of penile carcinoma

Energy Technology Data Exchange (ETDEWEB)

Petera, J.; Odrazka, K.; Zouhar, M.; Bedrosova, J.; Dolezel, M. [Dept. of Oncology and Radiotherapy, Charles Univ. Medical School and Teaching Hospital, Hradec Kralove (Czech Republic)

2004-02-01

Background: interstitial low-dose-rate (LDR) brachytherapy allows conservative treatment of T1-T2 penile carcinoma. High-dose-rate (HDR) is often considered to be dangerous for interstitial implants because of a higher risk of complications, but numerous reports suggest that results may be comparable to LDR. Nevertheless, there are no data in the literature available regarding HDR interstitial brachytherapy for carcinoma of the penis. Case report: a 64-year-old man with T1 NO MO epidermoid carcinoma of the glans is reported. Interstitial HDR brachytherapy was performed using the stainless hollow needle technique and a breast template for fixation and good geometry. The dose delivered was 18 x 3 Gy twice daily. Results: after 232 days from brachytherapy, the patient was without any evidence of the tumor, experienced no serious radiation-induced complications, and had a fully functional organ. Conclusion: HDR interstitial brachytherapy is feasible in selected case of penis carcinoma, when careful planning and small single fractions are used. (orig.)

Radiobiological restrictions and tolerance doses of repeated single-fraction hdr-irradiation of intersecting small liver volumes for recurrent hepatic metastases

Directory of Open Access Journals (Sweden)

Wust Peter

2010-05-01

Full Text Available Abstract Background To assess radiobiological restrictions and tolerance doses as well as other toxic effects derived from repeated applications of single-fraction high dose rate irradiation of small liver volumes in clinical practice. Methods Twenty patients with liver metastases were treated repeatedly (2 - 4 times at identical or intersecting locations by CT-guided interstitial brachytherapy with varying time intervals. Magnetic resonance imaging using the hepatocyte selective contrast media Gd-BOPTA was performed before and after treatment to determine the volume of hepatocyte function loss (called pseudolesion, and the last acquired MRI data set was merged with the dose distributions of all administered brachytherapies. We calculated the BED (biologically equivalent dose for a single dose d = 2 Gy for different α/β values (2, 3, 10, 20, 100 based on the linear-quadratic model and estimated the tolerance dose for liver parenchyma D90 as the BED exposing 90% of the pseudolesion in MRI. Results The tolerance doses D90 after repeated brachytherapy sessions were found between 22 - 24 Gy and proved only slightly dependent on α/β in the clinically relevant range of α/β = 2 - 10 Gy. Variance analysis showed a significant dependency of D90 with respect to the intervals between the first irradiation and the MRI control (p 90 and the pseudolesion's volume. No symptoms of liver dysfunction or other toxic effects such as abscess formation occurred during the follow-up time, neither acute nor on the long-term. Conclusions Inactivation of liver parenchyma occurs at a BED of approx. 22 - 24 Gy corresponding to a single dose of ~10 Gy (α/β ~ 5 Gy. This tolerance dose is consistent with the large potential to treat oligotopic and/or recurrent liver metastases by CT-guided HDR brachytherapy without radiation-induced liver disease (RILD. Repeated small volume irradiation may be applied safely within the limits of this study.

Pharmacokinetics and bioavailability of plant lignan 7-hydroxymatairesinol and effects on serum enterolactone and clinical symptoms in postmenopausal women: a single-blinded, parallel, dose-comparison study.

Science.gov (United States)

Udani, Jay K; Brown, Donald J; Tan, Maria Olivia C; Hardy, Mary

2013-01-01

7-Hydroxymaitairesinol (7-HMR) is a naturally occurring plant lignan found in whole grains and the Norway spruce (Piciea abies). The purpose of this study was to evaluate the bioavailability of a proprietary 7-HMR product (HMRlignan, Linnea SA, Locarno, Switzerland) through measurement of lignan metabolites and metabolic precursors. A single-blind, parallel, pharmacokinetic and dose-comparison study was conducted on 22 postmenopausal females not receiving hormone replacement therapy. Subjects were enrolled in either a 36 mg/d (low-dose) or 72 mg/d dose (high-dose) regimen for 8 weeks. Primary measured outcomes included plasma levels of 7-HMR and enterolactone (ENL), and single-dose pharmacokinetic analysis was performed on a subset of subjects in the low-dose group. Safety data and adverse event reports were collected as well as data on hot flash frequency and severity. Pharmacokinetic studies demonstrated 7-HMR C max = 757.08 ng/ml at 1 hour and ENL C max = 4.8 ng/ml at 24 hours. From baseline to week 8, plasma 7-HMR levels increased by 191% in the low-dose group (p < 0.01) and by 1238% in the high-dose group (p < 0.05). Plasma ENL levels consistently increased as much as 157% from baseline in the low-dose group and 137% in the high-dose group. Additionally, the mean number of weekly hot flashes decreased by 50%, from 28.0/week to 14.3/week (p < 0.05) in the high-dose group. No significant safety issues were identified in this study. The results demonstrate that HMRlignan is quickly absorbed into the plasma and is metabolized to ENL in healthy postmenopausal women. Clinically, the data demonstrate a statistically significant improvement in hot flash frequency. Doses up to 72 mg/d HMRlignan for 8 weeks were safe and well tolerated in this population.

Single fixed-dose oral dexketoprofen plus tramadol for acute postoperative pain in adults.

Science.gov (United States)

Derry, Sheena; Cooper, Tess E; Phillips, Tudor

2016-09-22

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. A new combination of dexketoprofen (a nonsteroidal anti-inflammatory drug) plus tramadol (an opioid) has been tested in acute postoperative pain conditions. It is not yet licensed for use. This review is one of a series on oral analgesics for acute postoperative pain. Individual reviews have been brought together in two overviews to provide information about the relative efficacy and harm of the different interventions. To assess the analgesic efficacy and adverse effects of a single fixed-dose of oral dexketoprofen plus tramadol, compared with placebo, for moderate to severe postoperative pain in adults, using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes. A secondary objective was to compare the combination with the individual analgesics alone. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via CRSO, MEDLINE via Ovid, and Embase via Ovid from inception to 31 May 2016. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries. Randomised, double-blind trials of oral dexketoprofen plus tramadol administered as a single oral dose, for the relief of acute postoperative pain in adults, and compared to placebo. Two review authors independently considered trials for inclusion in the review, examined issues of study quality and potential bias, and extracted data. For dichotomous outcomes, we calculated risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) for dexketoprofen plus tramadol, compared with placebo with 95% confidence intervals (CI). We collected information on the number of participants with at least 50% of

Quality control of 192Ir high dose rate after loading brachytherapy dose veracity

International Nuclear Information System (INIS)

Feng Zhongsu; Xu Xiao; Liu Fen

2008-01-01

Recently, 192 Ir high dose rate (HDR) afterloading are widely used in brachytherapy. The advantage of using HDR systems over low dose rate systems are shorter treatment time and higher fraction dose. To guarantee the veracity of the delivery dose, several quality control methods are deseribed in this work. With these we can improve the position precision, time precision and dose precision of the brachytherapy. (authors)

The effects of peritoneal dialysis on the single dose and steady state pharmacokinetics of valproic acid in a uremic epileptic child.

Science.gov (United States)

Orr, J M; Farrell, K; Abbott, F S; Ferguson, S; Godolphin, W J

1983-01-01

The pharmacokinetics of valproic acid (VPA) have been studied during peritoneal dialysis in a uremic male epileptic child following a single 500 mg dose and after multiple doses over 5 months (700 mg daily) of valproic acid as the syrup. Serum level decline was biphasic in both instances with a terminal half-life of 27.2 after the single dose and 10.2 h at steady-state. Total serum clearance was 0.0236 l/h/kg after the single dose and increased to 0.0408 l/h/kg after 5 months. Free (intrinsic) serum clearances were 0.1489 and 0.1518 l/h/kg and serum free fractions were 0.224 and 0.272 respectively for the single dose and steady-state studies. Peritoneal dialysis for periods of 12 or 24 h removed an average of 4.5% of the VPA dose.

Radiation-induced heart disease due to intrathonacic tumor radiotherapy of a single dose to the rabbits' heart

International Nuclear Information System (INIS)

Zhou Weibing; Feng Yan; Chen Jiayi; Luo Quanyong

2007-01-01

Objective: To observe the changes of radiation-induced heart disease (RIHD) in the rabbits irradiated in clinical related dose, and to evaluate the apoptosis and hypoxia in the irradiated heart by the new scintigraphic agents of 99 Tc m -HL91 and 99 Tc m -Annexin V of heart SPECT. Methods: Tenty-four New Zealand white rabbits 4-month old and 2-3 kg by weight were divided into two groups. Group 1 (clinical related dose group): 16 irradiated by a single close from 0 to 18 Gy. Group 2 (high dose group): 8 irradiated dose from 22 to 80 Gy. The serum cTnI/CKMB, ECG, and heart SPECT(using 99 Tc m -MIBI, 99 Tc m -HL91 and 99 Tc m -Annexin V as agents) were detected before and after irradiation. The animals were followed for 5 months. Then biopsy of rabbit heart was performed and pathologic examination was made by H.E. stain. Results: In the 16 rabbits of clinical related dose group, none died of RIHD. Whereas 2 rabbits died of RIHD in the high dose group. One died of myocardial infarction and the other of congestive heart failure. According to the Stewart introduced heart lesion grading system, of the clinical close ann, there were moderate in 1 rabbit, minimal in 14; and of the high dose ann, it was severe in 2, marked in 1, moderate in 5. The parallel relation was observed between the ECG results and the pathological changes (χ 2 =0.08, P=0.771). Serum value of cTnI, was elevated at the 12th hour after irradiation reaching the peak and maintained for 4 months. However, it came down in the 5th month. The difference of serum cTnI value before and after radiation was statistically significant. Myocardial perfusion scintigraphy tested by heart SPECT ( 99 Tc m -MIBI) showed defects was present in all irradiated rabbits. The relationship between the defects and radiation dose or between the defects and the real RIHD was uncertain. The SPECT images displayed that 99 Tc m -HL91 and 99m Tc-Annexin V did not accumulate in the irradiated heart. Conclusions: No serious damage is

Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT.

Science.gov (United States)

Paul, Jijo; Banckwitz, Rosemarie; Krauss, Bernhard; Vogl, Thomas J; Maentele, Werner; Bauer, Ralf W

2012-04-01

To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation. Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.014mSv/mGycm conversion coefficient k. Examinations were performed on a dual-source CT system (Somatom Definition Flash, Siemens). Four scan protocols were investigated: (1) single-source 120kV, (2) single-source 100kV, (3) high-pitch 120kV, and (4) dual-energy with 100/Sn140kV with equivalent CTDIvol and no automated tube current modulation. E was then determined following recommendations of ICRP publication 103 and 60 and specific k values were derived. DLP-based estimates differed by 4.5-16.56% and 5.2-15.8% relatively to ICRP 60 and 103, respectively. The derived k factors calculated from TLD measurements were 0.0148, 0.015, 0.0166, and 0.0148 for protocol 1, 2, 3 and 4, respectively. Effective dose estimations by ICRP 103 and 60 for single-energy and dual-energy protocols show a difference of less than 0.04mSv. Estimates of E based on DLP work equally well for single-energy, high-pitch and dual-energy CT examinations. The tube potential definitely affects effective dose in a substantial way. Effective dose estimations by ICRP 103 and 60 for both single-energy and dual-energy examinations differ not more than 0.04mSv. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Pharmacokinetically guided dosing of (high-dose) chemotherapeutic agents

NARCIS (Netherlands)

Attema-de Jonge, M.E. (Milly Ellen)

2004-01-01

Due to variation in drug distribution, metabolism and elimination processes between patients, systemic exposure to chemotherapeutic agents may be highly variable from patient to patient after administration of similar doses. This pharmacokinetic variability may explain in part the large variability

A Systematic Review on Effect of Single-Dose Preoperative Antibiotics at Surgical Osteotomy Extraction of Lower Third Molars

DEFF Research Database (Denmark)

Marcussen, Karoline Brørup; Laulund, Anne Sofie; Jørgensen, Henrik L

2016-01-01

PURPOSE: We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of a single dose of preoperative antibiotic administered perorally, intravenously, intramuscularly, or topically for preventing infection and alveolar osteitis in lower third molar...... that penicillin V was effective in reducing the incidence of alveolar osteitis (OR = 0.1; 95% CI, 0.03 to 0.30; P ≤ .0001). CONCLUSIONS: A single oral dose of 2 g of amoxicillin before lower third molar osteotomy surgical extraction significantly decreased the incidence of SSI. A single dose of 0.8 g...... of penicillin V before lower third molar osteotomy surgical extraction significantly decreased the incidence of alveolar osteitis....

Single-dose monomeric HA subunit vaccine generates full protection from influenza challenge

CSIR Research Space (South Africa)

Mallajosyula, JK

2014-03-01

Full Text Available 50% survival, or 100% survival with adjuvant, compared with 10% survival after vaccination with a commercially available H 1 N 1 vaccine. TMV-HA is an effective dose-sparing influenza vaccine, using a single-step process to rapidly generate large...

Sources of variability in OSL dose measurements using single grains of quartz

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, L.

2005-01-01

spread. In this preliminary study, dose distributions have been studied using single grains of heated and laboratory irradiated quartz. By heating the sample, the contribution from incomplete zeroing was excluded and at the same time the sample was sensitised. The laboratory gamma irradiation...

Effects of a preovulatory single low dose of mifepristone on ovarian function

NARCIS (Netherlands)

van der Stege, Jolande G.; Pahl-van Beest, Elske H.; Beerthuizen, Rob J. C. M.; van Lunsen, Rik H. W.; Scholten, Piet C.; Bogchelman, Dick H.

Objectives To investigate the effect of a single low dose of mifepristone on ovarian function, when administered in the preovulatory period. Methods Healthy women with regular menstrual cycles were studied during two consecutive menstrual cycles. Either mifepristone or placebo was given in a

Double versus single high-dose melphalan 200 mg/m2 and autologous stem cell transplantation for multiple myeloma: a region-based study in 484 patients from the Nordic area

Science.gov (United States)

Björkstrand, Bo; Klausen, Tobias W.; Remes, Kari; Gruber, Astrid; Knudsen, Lene M.; Bergmann, Olav J.; Lenhoff, Stig; Johnsen, Hans E.

2009-01-01

Autologous stem cell transplantation is still considered the standard of care in young patients with multiple myeloma (MM). This disease is the most common indication for high-dose therapy (HDT) supported by hematopoietic stem cell transplantation and much data support the benefit of this procedure. Results of randomized studies are in favor of tandem autologous transplantation although the effect on overall survival is unclear. Based on sequential registration trials in the Nordic area, we aimed to evaluate the outcome of conventional single or double HDT. During 1994–2000 we registered a total of 484 previously untreated patients under the age of 60 years at diagnosis who on a regional basis initially were treated with single [Trial NMSG #5/94 and #7/98 (N=383)] or double [Trial Huddinge Karolinska Turku Herlev (N=101)] high-dose melphalan (200 mg/m2) therapy supported by autologous stem cell transplantation. A complete or very good partial response was achieved by 40% of patients in the single transplant group and 60% of patients in the double transplant group (p=0.0006). The probability of surviving progression free for five years after the diagnosis was 25% (95% CL 18–32%) in the singletransplant group and 46% (95% CL 33–55%) in the double transplant group (p=0.0014). The estimated overall five-year survival rate was 60% in the single transplant group and 64% in the doubletransplant (p=0.9). In a multivariate analysis of variables, including single versus double transplantation, β2 microglobulin level, age, sex and disease stage, only β2 microglobulin level was predictive for overall survival (p>0.0001) and progression free survival (p=0.001). In accordance with these results, a 1:1 case-control matched comparison between double and single transplantation did not identify significant differences in overall and progression free survival. In this retrospective analysis up front double transplantation with melphalan (200 mg/m2) as compared to single

Estimation and comparison of effective dose (E) in standard chest CT by organ dose measurements and dose-length-product methods and assessment of the influence of CT tube potential (energy dependency) on effective dose in a dual-source CT

International Nuclear Information System (INIS)

Paul, Jijo; Banckwitz, Rosemarie; Krauss, Bernhard; Vogl, Thomas J.; Maentele, Werner; Bauer, Ralf W.

2012-01-01

Highlights: ► The dual-energy protocol delivers the lowest effective dose of the investigated protocols for standard chest CT examinations, thus enabling functional imaging (like dual-energy perfusion) and can produce weighted images without dose penalty. ► The high-pitch protocol goes along with a 16% increase in dose compared to the standard 120 kV protocol and thus should preferably be used in pediatric, acute care settings (e.g. pulmonary embolism, aortic dissection and the like) or restless patients. ► The difference in effective dose estimates between ICRP 60 and 103 is minimal. ► Tube potential definitely has an effect on estimates of effective dose. - Abstract: Purpose: To determine effective dose (E) during standard chest CT using an organ dose-based and a dose-length-product-based (DLP) approach for four different scan protocols including high-pitch and dual-energy in a dual-source CT scanner of the second generation. Materials and methods: Organ doses were measured with thermo luminescence dosimeters (TLD) in an anthropomorphic male adult phantom. Further, DLP-based dose estimates were performed by using the standard 0.014 mSv/mGycm conversion coefficient k. Examinations were performed on a dual-source CT system (Somatom Definition Flash, Siemens). Four scan protocols were investigated: (1) single-source 120 kV, (2) single-source 100 kV, (3) high-pitch 120 kV, and (4) dual-energy with 100/Sn140 kV with equivalent CTDIvol and no automated tube current modulation. E was then determined following recommendations of ICRP publication 103 and 60 and specific k values were derived. Results: DLP-based estimates differed by 4.5–16.56% and 5.2–15.8% relatively to ICRP 60 and 103, respectively. The derived k factors calculated from TLD measurements were 0.0148, 0.015, 0.0166, and 0.0148 for protocol 1, 2, 3 and 4, respectively. Effective dose estimations by ICRP 103 and 60 for single-energy and dual-energy protocols show a difference of less than 0.04 m

Functional and morphological changes in pig skin after single or fractionated doses in x rays

International Nuclear Information System (INIS)

Young, C.M.A.; Hopewell, J.W.

1982-01-01

The flank skin of pigs has been treated with either single or fractionated doses of x-irradiation. A single dose (2070 cGy) was compared with treatment given as 6 fractions in 18 days (6f/18 days; 3780 cGy) or 30 fractions in 39 days (30f/39 days; 8000 cGy). The doses were selected on the basis that similar levels of late tissue damage would result. Radiation induced changes in the skin were assessed by observing the skin reactions and by the measurement of isotope clearance (functional study), relative field contraction, dermal and epidermal thickness and dermal vascular density (morphological studies). In the three treatment groups the early radiation reaction varied considerably. In the first wave reaction (3 to 6 weeks after treatment) bright red erythema was recorded in many fields but moist desquamation developed only in the 30f/39 days treatment group. The second wave (10-16 weeks) was characterized by an ischemic mauve/dusky reaction. Dermal necrosis developed in 50% of the single dose fields. In the 30f/39 days regimen persistent moist desquamation progressed to dermal necrosis. Neither desquamation nor necrosis developed after 6f/18 days. Different levels of vascular damage in the dermis were assessed using an isotope clearance technique; for example in the early reaction significant changes were recorded in the papillary dermis (faster clearance) prior to the development of moist desquamation (30f/39 days) and in the reticular dermis (slower clearance) before necrosis (single dose). Changes in clearance rates have been correlated with changes in the vascular density and thickness of the dermis. Between 26 and 52 weeks (the late reaction) relative field contraction was slightly greater in the 30f/39 days group than in the other treatment groups

Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

International Nuclear Information System (INIS)

Leith, J.L.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Walton, R.E.; Woodruff, K.H.; Howard, J.

1980-01-01

The response of rat spinal cord to irradiation with accelerated heavy ions, in particular carbon and neon ions has been studied. Two different ionization regions in the modified Bragg curve for each ion have been studied for both single and fractionated exposures. We have defined the paralytic response as a function of dose and dose per fraction, and we have determined RBE and repair values. The response of rat spinal cord is both dose and LET dependent, which allows the derivation of RBE and repair values

The effectiveness of low-dose and high-dose tranexamic acid in posterior lumbar interbody fusion: a double-blinded, placebo-controlled randomized study.

Science.gov (United States)

Kim, Ki-Tack; Kim, Cheung-Kue; Kim, Yong-Chan; Juh, Hyung-Suk; Kim, Hyo-Jong; Kim, Hyeon-Soo; Hong, Se Jung; Hey, Hwee Weng Dennis

2017-11-01

Tranexamic acid is a proven drug used for reduction of intraoperative blood loss in spinal surgery. However, optimal dosing considering risk/benefits is not well established owing to the heterogeneity in patient selection and surgical procedures of previous studies. This study aimed to evaluate the effectiveness and safety of various tranexamic acid regimens in reducing perioperative blood loss in single-level posterior lumbar interbody fusion (PLIF). Patients were randomly grouped into three different interventions: low-dose tranexamic acid (LD), high-dose tranexamic acid (HD), and placebo-controlled (PC) groups. The HD and LD groups received 10 and 5 mg/kg of bolus loading dose and 2 and 1 mg/kg of continuous infusion until 5 h after surgery, respectively. Data on patient demographics and preoperative and 24-h postoperative laboratory values were collected. Outcome parameters include intraoperative blood loss, 24-h postoperative blood loss, and blood loss during removal of the last drain. Seventy-two patients (mean age 63.3 ± 7.6 years) showed similar baseline characteristics. Intraoperatively, blood loss was reduced by the administration of tranexamic acid (P = 0.04), contributed predominantly by a difference between the LD and HD groups (123 mL; P tranexamic acid use were noted. Tranexamic acid administration for single-level PLIF was effective and safe in reducing perioperative blood loss in a dose-dependent manner. An HD regimen comprising 10 mg/kg of bolus loading dose and 2 mg/kg/h of continuous infusion is recommended. Level 1 study according to Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence.

Cell kinetic changes in the follicular epithelium of pig skin after irradiation with single and fractionated doses of X rays

International Nuclear Information System (INIS)

Morris, G.M.; Hopewell, J.W.

1989-01-01

Changes in cell kinetics of the follicular epithelium of the pig were studied after x-irradiation with single and fractionated doses (30 fractions/39 days) and compared with previous epidermal data. In the follicular epithelium there was an initial degenerative phase, when the rate of cell depletion was independent of radiation dose and mode of administration. Repopulation was seen between the 14th and 18th days after single doses (15 or 20 Gy) and by the 28th day after the start of irradiation with fractionated doses (52.3-80.0 Gy). The degree of cell depletion and subsequent rate of repopulation were independent of dose. The regenerative phase was characterized by an increased cell proliferation. Islands of cells with appearance similar to cells in the normal follicular epithelium, were seen 18 days after a single dose of 20 Gy and 42 days after the start of fractionated irradiation. Compared with the epidermis, the follicular epithelium exhibited considerably less evidence of damage after both single and fractionated doses. There was a lower incidence of degenerate cells and reduced levels of cell depletion in the follicular epithelium. (author)

Sources of variability in OSL dose measurements using single grains of quartz

International Nuclear Information System (INIS)

Thomsen, K.J.; Murray, A.S.; Boetter-Jensen, L.

2005-01-01

In luminescence-based measurements of dose distributions in unheated mineral samples, the observed spread in dose values is usually attributed to four main factors: fluctuations in the number of photons counted, incomplete zeroing of any prior trapped charge (including signals arising from thermal transfer), heterogeneity in dosimetry, and instrument reproducibility. For correct interpretation of measured dose distributions in retrospective dosimetry, it is important to understand the relative importance of these components, and to establish whether other factors also contribute to the observed spread. In this preliminary study, dose distributions have been studied using single grains of heated and laboratory irradiated quartz. By heating the sample, the contribution from incomplete zeroing was excluded and at the same time the sample was sensitised. The laboratory gamma irradiation was designed to deliver a uniform dose to the sample. Thus it was anticipated that statistical fluctuations in the number of photons counted and instrument reproducibility, both quantifiable entities, should be able to account for all the observed variance in the measured dose distributions. We examine this assumption in detail, and discuss the origins and importance of the residual variance in our data

Singlet oxygen and ROS in a new light: low-dose subcellular photodynamic treatment enhances proliferation at the single cell level.

Science.gov (United States)

Blázquez-Castro, Alfonso; Breitenbach, Thomas; Ogilby, Peter R

2014-09-01

Two-photon excitation of a sensitizer with a focused laser beam was used to create a spatially-localized subcellular population of reactive oxygen species, ROS, in single HeLa cells. The sensitizer used was protoporphyrin IX, PpIX, endogenously derived from 5-aminolevulinic acid delivered to the cells. Although we infer that singlet oxygen, O2(a(1)Δg), is one ROS produced upon irradiation of PpIX under these conditions, it is possible that the superoxide ion, O2(-˙), may also play a role in this system. With a "high" dose of PpIX-sensitized ROS, the expected death of the cell was observed. However, under "low dose" conditions, clear signs of cell proliferation were observed. The present results facilitate studies of ROS-mediated signalling in imaging-based single cell experiments.

Evaluation of sphingolipids in Wistar rats treated to prolonged and single oral doses of fumonisin b₁.

Science.gov (United States)

Direito, Glória M; Almeida, Adriana P; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

2009-01-01

The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B(1) (FB(1)). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB(1). Prolonged exposure to FB(1) caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB(1). Animals receiving a single dose of FB(1) presented variations in Sa and So levels and in the Sa/So ratio.

Effect of high-dose dexamethasone on perioperative lactate levels and glucose control : a randomized controlled trial

NARCIS (Netherlands)

Ottens, Thomas H; Nijsten, Maarten W N; Hofland, Jan; Dieleman, Stefan; Hoekstra, Miriam; van Dijk, Diederik; van der Maaten, Joost Maa

2015-01-01

INTRODUCTION: Blood lactate levels are increasingly used to monitor patients. Steroids are frequently administered to critically ill patients. However, the effect of steroids on lactate levels has not been adequately investigated. We studied the effect of a single intraoperative high dose of

Physiological and immunological changes following exposure to low versus high-dose ionizing irradiation; comparative analysis with dose rate and cumulative dose

International Nuclear Information System (INIS)

Heesun, Kim; Heewon, Jang; Soungyeon, Song; Shinhye, Oh; Cukcheul, Shin; Meeseon, Jeong; Chasoon, Kim; Kwnaghee, Yang; Seonyoung, Nam; Jiyoung, Kim; Youngwoo, Jin; Changyoung, Cha

2008-01-01

Full text: While high-dose of ionizing radiation is generally harmful and causes damage to living organisms some reports suggest low-dose of radiation may not be as damaging as previously thought. Despite increasing evidence regarding the protective effect of low-dose radiation, no studies have directly compared the exact dose-response pattern by high- and low-dose of radiation exposed at high-and low-dose rate. This study aims to explore the cellular and molecular changes in mice exposed to low- and high-dose of radiation exposed at low- and high-dose rate. When C57BL/6 mice (Female, 6 weeks) were exposed at high-dose rate, 0.8 Gy/min, no significant change on the level of WBC, RBC, or platelets was observed up to total dose of 0.5 Gy. However, 2 Gy of radiation caused dramatic reduction in the level of white blood cells (WBC) and platelets. This reduction was accompanied by increased DNA damage in hematopoietic environments. The reduction of WBC was mainly due to the reduction in the number of CD4+ T cells and CD19+ B cells. CD8+ T cells and NK cells appeared to be relatively resistant to high-dose of radiation. This change was also accompanied by the reduction of T- and B- progenitor cells in the bone marrow. In contrast, no significant changes of the number of CD4+ T, CD8+ T, NK, and B cells were observed in the spleen of mice exposed at low-dose-rate (0.7 m Gy/h or 3.95 mGy/h) for up to 2 Gy, suggesting that low-dose radiation does not alter cellular distribution in the spleen. Nevertheless, mice exposed to low-dose radiation exhibited elevation of VEGF, MCP-1, IL-4, Leptin, IL-3, and Tpo in the peripheral blood and slight increases in MIP-2, RANTES, and IL-2 in the spleen. This suggests that chronic γ-radiation can stimulate immune function without causing damage to the immune components of the body. Taken together, these data indicate hormesis of low-dose radiation, which could be attributed to the stimulation of immune function. Dose rate rather than total

Safety, tolerability and pharmacokinetics of doravirine, a novel HIV non-nucleoside reverse transcriptase inhibitor, after single and multiple doses in healthy subjects.

Science.gov (United States)

Anderson, Matt S; Gilmartin, Jocelyn; Cilissen, Caroline; De Lepeleire, Inge; Van Bortel, Luc; Dockendorf, Marissa F; Tetteh, Ernestina; Ancona, June K; Liu, Rachael; Guo, Ying; Wagner, John A; Butterton, Joan R

2015-01-01

Doravirine is a novel non-nucleoside inhibitor of HIV-1 reverse transcriptase with potent activity against wild-type virus (95% inhibitory concentration 19 nM, 50% human serum). Doravirine has low potential to cause drug-drug interactions since it is primarily eliminated by oxidative metabolism and does not inhibit or significantly induce drug-metabolizing enzymes. The pharmacokinetics and safety of doravirine were investigated in two double-blind, dose-escalation studies in healthy males. Thirty-two subjects received single doses of doravirine (6-1,200 mg) or matching placebo tablets; 40 subjects received doravirine (30-750 mg) or matching placebo tablets once daily for 10 days. In addition, the effect of doravirine (120 mg for 14 days) on single-dose pharmacokinetics of the CYP3A substrate midazolam was evaluated (10 subjects). The maximum plasma concentration (Cmax) of doravirine was achieved within 1-5 h with an apparent terminal half-life of 12-21 h. Consistent with single-dose pharmacokinetics, steady state was achieved after approximately 7 days of once daily administration, with accumulation ratios (day 10/day 1) of 1.1-1.5 in the area under the plasma concentration-time curve during the dosing interval (AUC0-24 h), Cmax and trough plasma concentration (C24 h). All dose levels produced C24 h>19 nM. Administration of 50 mg doravirine with a high-fat meal was associated with slight elevations in AUC time zero to infinity (AUC0-∞) and C24 h with no change in Cmax. Midazolam AUC0-∞ was slightly reduced by coadministration of doravirine (geometric mean ratio 0.82, 90% CI 0.70, 0.97). There was no apparent relationship between adverse event frequency or intensity and doravirine dose. No rash or significant central nervous system events other than headache were reported. Doravirine is generally well tolerated in single doses up to 1,200 mg and multiple doses up to 750 mg once daily for up to 10 days, with a pharmacokinetic profile supportive of once

Prehospital high-dose sublingual nitroglycerin rarely causes hypotension.

Science.gov (United States)

Clemency, Brian M; Thompson, Jeffrey J; Tundo, Gina N; Lindstrom, Heather A

2013-10-01

High-dose intravenous nitroglycerin is a common in-hospital treatment for respiratory distress due to congestive heart failure (CHF) with hypertension. Intravenous (IV) nitroglycerin administration is impractical in the prehospital setting. In 2011, a new regional Emergency Medical Services (EMS) protocol was introduced allowing advanced providers to treat CHF with high-dose oral nitroglycerin. The protocol calls for patients to be treated with two sublingual tabs (0.8 mg) when systolic blood pressure (SBP) was >160 mm Hg, or three sublingual tabs (1.2 mg) when SBP was >200 mm Hg, every five minutes as needed. Hypothesis/Problem To assess the protocol's safety, the incidence of hypotension following prehospital administration of multiple simultaneous nitroglycerin (MSN) tabs by EMS providers was studied. This study was a retrospective cohort study of patients from a single commercial EMS agency over a 6-month period. Records from patients with at least one administration of MSN were reviewed. For each administration, the first documented vital signs pre- and post-administration were compared. Administrations were excluded if pre- or post-administration vital signs were missing. One hundred case-patients had at least one MSN administration by an advanced provider during the study period. Twenty-five case-patients were excluded due to incomplete vital signs. Seventy-five case-patients with 95 individual MSN administrations were included for analysis. There were 65 administrations of two tabs, 29 administrations of three tabs, and one administration of four tabs. The mean change in SBP following MSN was -14.7 mm Hg (SD = 30.7; range, +59 to -132). Three administrations had documented systolic hypotension in the post-administration vital signs (97/71, 78/50 and 66/47). All three patients were over 65 years old, were administered two tabs, had documented improved respiratory status, and had repeat SBP of at least 100. The incidence of hypotension following MSN

Braquiterapia de alta taxa de dose no Brasil High-dose rate brachytherapy in Brazil

Directory of Open Access Journals (Sweden)

Sérgio Carlos Barros Esteves

2004-10-01

Full Text Available A braquiterapia de alta taxa de dose foi introduzida em nosso meio em janeiro de 1991. Desde então, houve uma mudança significativa na abordagem das neoplasias malignas em relação às vantagens do novo método, e também resolução da demanda reprimida de braquiterapia para as neoplasias ginecológicas. Nos primeiros dez anos de atividade, o Brasil tratou, em 31 serviços, 26.436 pacientes com braquiterapia, sendo mais de 50% das pacientes portadoras de neoplasias do colo uterino. Este estudo mostra o número e o perfil de pacientes tratados com esse método e a sua distribuição no território nacional, deixando explícito o benefício da braquiterapia de alta taxa de dose para o Brasil.High-dose rate brachytherapy was first introduced in Brazil in January 1991. Significant changes in the management of malignant neoplasms were observed since utilization of high-dose rate brachytherapy. The high number of gynecological patients awaiting for brachytherapy also decreased during this period. In the first ten years 26,436 patients were treated with high-dose rate brachytherapy. More than 50% of these patients presented neoplasms of the uterine cervix. In this study we present the number and profile of the patients treated with high-dose rate brachytherapy as well as the distribution of these patients in the Brazilian territory, proving the benefit of the use of high-dose rate brachytherapy in Brazil.

Need for High Radiation Dose (≥70 Gy) in Early Postoperative Irradiation After Radical Prostatectomy: A Single-Institution Analysis of 334 High-Risk, Node-Negative Patients

International Nuclear Information System (INIS)

Cozzarini, Cesare; Montorsi, Francesco; Fiorino, Claudio; Alongi, Filippo; Bolognesi, Angelo; Da Pozzo, Luigi Filippo; Guazzoni, Giorgio; Freschi, Massimo; Roscigno, Marco; Scattoni, Vincenzo; Rigatti, Patrizio; Di Muzio, Nadia

2009-01-01

Purpose: To determine the clinical benefit of high-dose early adjuvant radiotherapy (EART) in high-risk prostate cancer (hrCaP) patients submitted to radical retropubic prostatectomy plus pelvic lymphadenectomy. Patients and Methods: The clinical outcome of 334 hrCaP (pT3-4 and/or positive resection margins) node-negative patients submitted to radical retropubic prostatectomy plus pelvic lymphadenectomy before 2004 was analyzed according to the EART dose delivered to the prostatic bed, <70.2 Gy (lower dose, median 66.6 Gy, n = 153) or ≥70.2 Gy (median 70.2 Gy, n = 181). Results: The two groups were comparable except for a significant difference in terms of median follow-up (10 vs. 7 years, respectively) owing to the gradual increase of EART doses over time. Nevertheless, median time to prostate-specific antigen (PSA) failure was almost identical, 38 and 36 months, respectively. At univariate analysis, both 5-year biochemical relapse-free survival (bRFS) and disease-free survival (DFS) were significantly higher (83% vs. 71% [p = 0.001] and 94% vs. 88% [p = 0.005], respectively) in the HD group. Multivariate analysis confirmed EART dose ≥70 Gy to be independently related to both bRFS (hazard ratio 2.5, p = 0.04) and DFS (hazard ratio 3.6, p = 0.004). Similar results were obtained after the exclusion of patients receiving any androgen deprivation. After grouping the hormone-naive patients by postoperative PSA level the statistically significant impact of high-dose EART on both 5-year bRFS and DFS was maintained only for those with undetectable values, possibly owing to micrometastatic disease outside the irradiated area in case of detectable postoperative PSA values. Conclusion: This series provides strong support for the use of EART doses ≥70 Gy after radical retropubic prostatectomy in hrCaP patients with undetectable postoperative PSA levels.

Concentrations of amoxicillin and clindamycin in teeth following a single dose of oral medication.

Science.gov (United States)

Schüssl, Yvonne; Pelz, Klaus; Kempf, Jürgen; Otten, Jörg-Elard

2014-01-01

The main purpose of this study is the detection of amoxicillin and clindamycin concentrations in teeth. Eleven patients received 2 g of amoxicillin, and 11 patients received 600 mg of clindamycin in a single dose of oral medication at least 60 min prior to tooth extraction due to systemic diseases. The concentrations were determined in crowns and roots separately using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Amoxicillin (13 samples) and clindamycin (12 samples) were detected in the samples of the root and crown preparations of the extracted teeth. The mean concentration of amoxicillin was 0.502 μg/g in the roots and 0.171 μg/g in the crowns. The mean concentration of clindamycin was 0.270 μg/g in the roots and 0.064 μg/g in the crowns. A single dose of oral amoxicillin and clindamycin leads to concentrations of both antibiotics in teeth which exceed the minimal inhibition concentration of some oral bacteria. The proof of antibacterial activity in dental hard tissue after oral single-dose application is new. The antimicrobial effect of amoxicillin and clindamycin concentrations in roots of teeth may be of clinical relevance to bacterial reinfection from dentinal tubules.

Investigation of radial dose effect on single event upset cross-section due to heavy ions using GEANT4

International Nuclear Information System (INIS)

Boorboor, S.; Feghhi, S.A.H.; Jafari, H.

2015-01-01

The heavy ions are the main cause to produce single event upset (SEU) damage on electronic devices since they are high LET radiations. The dimension of electronic components in new technology, arise a challenge in radiation effect estimations. Accurate investigations require fully considering the ion track in energy deposition as a radial dose distribution. In this work, the distribution of delta rays as well as LET have been calculated to determine ionization structure around ion track by a Monte Carlo code, GEANT4. The radial dose of several heavy ions with different energy in silicon was investigated and compared with the works by other authors in this field. The results showed that heavy ions with identical LET can have different SEU cross-section in silicon transistors. As a demonstrative example, according to our results, the error probability for 4.8 GeV iron was 8 times greater than that for 15 MeV carbon ions, in transistors with new process technology which have small dimension and low critical charges. Our results show that considering radial dose distribution considerably improves the accuracy of the SEU cross-section estimation in electronic devices especially for new technologies. - Highlights: • The single event upset is produced by heavy ions interaction on electronic devices. • The radial dose of several heavy ions in silicon was calculated by GEANT4. • Heavy ions with identical LET had different SEU cross-section in silicon transistors. • Low dimension and critical charge devices were more sensitive to radial dose effect

Measured Neutron Spectra and Dose Equivalents From a Mevion Single-Room, Passively Scattered Proton System Used for Craniospinal Irradiation

Energy Technology Data Exchange (ETDEWEB)

Howell, Rebecca M., E-mail: rhowell@mdanderson.org [Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Burgett, Eric A.; Isaacs, Daniel [Department of Nuclear Engineering, Idaho State University, Pocatello, Idaho (United States); Price Hedrick, Samantha G.; Reilly, Michael P.; Rankine, Leith J.; Grantham, Kevin K.; Perkins, Stephanie; Klein, Eric E. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States)

2016-05-01

Purpose: To measure, in the setting of typical passively scattered proton craniospinal irradiation (CSI) treatment, the secondary neutron spectra, and use these spectra to calculate dose equivalents for both internal and external neutrons delivered via a Mevion single-room compact proton system. Methods and Materials: Secondary neutron spectra were measured using extended-range Bonner spheres for whole brain, upper spine, and lower spine proton fields. The detector used can discriminate neutrons over the entire range of the energy spectrum encountered in proton therapy. To separately assess internally and externally generated neutrons, each of the fields was delivered with and without a phantom. Average neutron energy, total neutron fluence, and ambient dose equivalent [H* (10)] were calculated for each spectrum. Neutron dose equivalents as a function of depth were estimated by applying published neutron depth–dose data to in-air H* (10) values. Results: For CSI fields, neutron spectra were similar, with a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate continuum between the evaporation and thermal peaks. Neutrons in the evaporation peak made the largest contribution to dose equivalent. Internal neutrons had a very low to negligible contribution to dose equivalent compared with external neutrons, largely attributed to the measurement location being far outside the primary proton beam. Average energies ranged from 8.6 to 14.5 MeV, whereas fluences ranged from 6.91 × 10{sup 6} to 1.04 × 10{sup 7} n/cm{sup 2}/Gy, and H* (10) ranged from 2.27 to 3.92 mSv/Gy. Conclusions: For CSI treatments delivered with a Mevion single-gantry proton therapy system, we found measured neutron dose was consistent with dose equivalents reported for CSI with other proton beamlines.

Cumulative doses analysis in young trauma patients: a single-centre experience.

Science.gov (United States)

Salerno, Sergio; Marrale, Maurizio; Geraci, Claudia; Caruso, Giuseppe; Lo Re, Giuseppe; Lo Casto, Antonio; Midiri, Massimo

2016-02-01

Multidetector computed tomography (MDCT) represents the main source of radiation exposure in trauma patients. The radiation exposure of young patients is a matter of considerable medical concern due to possible long-term effects. Multiple MDCT studies have been observed in the young trauma population with an increase in radiation exposure. We have identified 249 young adult patients (178 men and 71 women; age range 14-40 years) who had received more than one MDCT study between June 2010 and June 2014. According to the International Commission on Radiological Protection publication, we have calculated the cumulative organ dose tissue-weighting factors by using CT-EXPO software(®). We have observed a mean cumulative dose of about 27 mSv (range from 3 to 297 mSv). The distribution analysis is characterised by low effective dose, below 20 mSv, in the majority of the patients. However, in 29 patients, the effective dose was found to be higher than 20 mSv. Dose distribution for the various organs analysed (breasts, ovaries, testicles, heart and eye lenses) shows an intense peak for lower doses, but in some cases high doses were recorded. Even though cumulative doses may have long-term effects, which are still under debate, high doses are observed in this specific group of young patients.

Single and 2-week repeated intravenous dose toxicity studies of disodium mercaptoundecahydro-closo-dodecaborate in rats

Energy Technology Data Exchange (ETDEWEB)

Itoh, Fumio; Yabuuchi, Kazuya; Ohno, Kouji; Muraoka, Yoshihiro [Shionogi and Co. Ltd., Toyonaka, Osaka (Japan). Developmental Research Lab.; Ikeuchi, Isao

1998-10-01

Disodium mercaptoundecahydro-closo-dodecaborate (BSH) is a boron compound used in Boron Neutron Capture Therapy for malignant brain tumors. Intravenous single and 2-week repeated dose toxicity studies of BSH were performed in Sprague-Dawley rats. In the single-dose study, BSH was administered at doses of 100, 300 or 600 mg/kg. Death occurred within 10 min (acute type) or from 5 hr to 2 days (delayed type) after dosing in the 600 mg/kg group. No differences in mortality by sex and dosing speed were observed. Major causes of death were considered to be circulatory disorder in acute death and renal injury in delayed death. The renal injury was observed in the 300 and 600 mg/kg groups. In the 2-week repeated dose study, BSH was administered at doses of 30, 100 or 300 mg/kg/day for 14 days. Body weight gain was suppressed in the 100 and 300 mg/kg groups. One male in the 300 mg/kg group died due to renal and pulmonary lesions at day 8. Slight anemia was observed in the 300 mg/kg group. Pathologically, the kidney showed tubular regeneration with increase of weight in the 300 mg/kg. From these results, the NOAEL of BSH is 30 mg/kg/day. (author)

Optimal timing and frequency of bone marrow soup therapy for functional restoration of salivary glands injured by single-dose or fractionated irradiation.

Science.gov (United States)

Fang, Dongdong; Shang, Sixia; Liu, Younan; Bakkar, Mohammed; Sumita, Yoshinori; Seuntjens, Jan; Tran, Simon D

2018-02-01

Injections of bone marrow (BM) cell extract, known as 'BM soup', were previously reported to mitigate ionizing radiation (IR) injury to salivary glands (SGs). However, the optimal starting time and frequency to maintain BM soup therapeutic efficacy remains unknown. This study tested the optimal starting time and frequency of BM soup injections in mice radiated with either a single dose or a fractionated dose. First, BM soup treatment was started at 1, 3 or 7 weeks post-IR; positive (non-IR) and negative (IR) control mice received injections of saline (vehicle control). Second, BM soup-treated mice received injections at different frequencies (1, 2, 3 and 5 weekly injections). Third, a 'fractionated-dose radiation' model to injure mouse SGs was developed (5 Gy × 5 days) and compared with the single high dose radiation model. All mice (n = 65) were followed for 16 weeks post-IR. The results showed that starting injections of BM soup between 1 and 3 weeks mitigated the effect of IR-induced injury to SGs and improved the restoration of salivary function. Although the therapeutic effect of BM soup lessens after 8 weeks, it can be sustained by increasing the frequency of weekly injections. Moreover, both single-dose and fractionated-dose radiation models are efficient and comparable in inducing SG injury and BM soup treatments are effective in restoring salivary function in both radiation models. In conclusion, starting injections of BM soup within 3 weeks post-radiation, with 5 weekly injections, maintains 90-100% of saliva flow in radiated mice. Copyright © 2017 John Wiley & Sons, Ltd.

Real-time Tumor Oxygenation Changes After Single High-dose Radiation Therapy in Orthotopic and Subcutaneous Lung Cancer in Mice: Clinical Implication for Stereotactic Ablative Radiation Therapy Schedule Optimization

Energy Technology Data Exchange (ETDEWEB)

Song, Changhoon [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Hong, Beom-Ju; Bok, Seoyeon; Lee, Chan-Ju; Kim, Young-Eun [Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Jeon, Sang-Rok [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Wu, Hong-Gyun [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Lee, Yun-Sang [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Department of Molecular Medicine and Biopharmaceutical Sciences, Seoul National University College of Medicine, Seoul (Korea, Republic of); Cheon, Gi Jeong; Paeng, Jin Chul [Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Carlson, David J. [Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut (United States); and others

2016-07-01

Purpose: To investigate the serial changes of tumor hypoxia in response to single high-dose irradiation by various clinical and preclinical methods to propose an optimal fractionation schedule for stereotactic ablative radiation therapy. Methods and Materials: Syngeneic Lewis lung carcinomas were grown either orthotopically or subcutaneously in C57BL/6 mice and irradiated with a single dose of 15 Gy to mimic stereotactic ablative radiation therapy used in the clinic. Serial [{sup 18}F]-misonidazole (F-MISO) positron emission tomography (PET) imaging, pimonidazole fluorescence-activated cell sorting analyses, hypoxia-responsive element-driven bioluminescence, and Hoechst 33342 perfusion were performed before irradiation (day −1), at 6 hours (day 0), and 2 (day 2) and 6 (day 6) days after irradiation for both subcutaneous and orthotopic lung tumors. For F-MISO, the tumor/brain ratio was analyzed. Results: Hypoxic signals were too low to quantitate for orthotopic tumors using F-MISO PET or hypoxia-responsive element-driven bioluminescence imaging. In subcutaneous tumors, the maximum tumor/brain ratio was 2.87 ± 0.483 at day −1, 1.67 ± 0.116 at day 0, 2.92 ± 0.334 at day 2, and 2.13 ± 0.385 at day 6, indicating that tumor hypoxia was decreased immediately after irradiation and had returned to the pretreatment levels at day 2, followed by a slight decrease by day 6 after radiation. Pimonidazole analysis also revealed similar patterns. Using Hoechst 33342 vascular perfusion dye, CD31, and cleaved caspase 3 co-immunostaining, we found a rapid and transient vascular collapse, which might have resulted in poor intratumor perfusion of F-MISO PET tracer or pimonidazole delivered at day 0, leading to decreased hypoxic signals at day 0 by PET or pimonidazole analyses. Conclusions: We found tumor hypoxia levels decreased immediately after delivery of a single dose of 15 Gy and had returned to the pretreatment levels 2 days after irradiation and had decreased

Radiotherapy for calcaneodynia. Results of a single center prospective randomized dose optimization trial

Energy Technology Data Exchange (ETDEWEB)

Ott, O.J.; Jeremias, C.; Gaipl, U.S.; Frey, B.; Schmidt, M.; Fietkau, R. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

2013-04-15

The aim of this work was to compare the efficacy of two different dose fractionation schedules for radiotherapy of patients with calcaneodynia. Between February 2006 and April 2010, 457 consecutive evaluable patients were recruited for this prospective randomized trial. All patients received radiotherapy using the orthovoltage technique. One radiotherapy series consisted of 6 single fractions/3 weeks. In case of insufficient remission of pain after 6 weeks a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. Endpoint was pain reduction. Pain was measured before, immediately after, and 6 weeks after radiotherapy using a visual analogue scale (VAS) and a comprehensive pain score (CPS). The overall response rate for all patients was 87 % directly after and 88 % 6 weeks after radiotherapy. The mean VAS values before, immediately after, and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 65.5 {+-} 22.1 and 64.0 {+-} 20.5 (p = 0.188), 34.8 {+-} 24.7 and 39.0 {+-} 26.3 (p = 0.122), and 25.1 {+-} 26.8 and 28.9 {+-} 26.8 (p = 0.156), respectively. The mean CPS before, immediately after, and 6 weeks after treatment was 10.1 {+-} 2.7 and 10.0 {+-} 3.0 (p = 0.783), 5.6 {+-} 3.7 and 6.0 {+-} 3.9 (p = 0.336), 4.0 {+-} 4.1 and 4.3 {+-} 3.6 (p = 0.257), respectively. No statistically significant differences between the two single dose trial arms for early (p = 0.216) and delayed response (p = 0.080) were found. Radiotherapy is an effective treatment option for the management of calcaneodynia. For radiation protection reasons, the dose for a radiotherapy series is recommended not to exceed 3-6 Gy. (orig.)

Liposomal bupivacaine as a single-injection peripheral nerve block: a dose-response study.

Science.gov (United States)

Ilfeld, Brian M; Malhotra, Nisha; Furnish, Timothy J; Donohue, Michael C; Madison, Sarah J

2013-11-01

Currently available local anesthetics approved for single-injection peripheral nerve blocks have a maximum duration of fashion. The end points included the maximum voluntary isometric contraction (MVIC) of the quadriceps femoris muscle and tolerance to cutaneous electrical current in the femoral nerve distribution. Measurements were performed from baseline until quadriceps MVIC returned to 80% of baseline bilaterally. There were statistically significant dose responses in MVIC (0.09%/mg, SE = 0.03, 95% confidence interval [CI], 0.04-0.14, P = 0.002) and tolerance to cutaneous current (-0.03 mA/mg, SE = 0.01, 95% CI, -0.04 to -0.02, P 40 mg, tolerance to cutaneous current did not return to within 20% above baseline until after 24 hours in 100% of subjects (95% CI, 56%-100%). MVIC did not consistently return to within 20% of baseline until after 24 hours in 90% of subjects (95% CI, 54%-100%). Motor block duration was not correlated with bupivacaine dose (0.06 hour/mg, SE = 0.14, 95% CI, -0.27 to 0.39, P = 0.707). The results of this investigation suggest that deposition of a liposomal bupivacaine formulation adjacent to the femoral nerve results in a partial sensory and motor block of >24 hours for the highest doses examined. However, the high variability of block magnitude among subjects and inverse relationship of dose and response magnitude attests to the need for a phase 3 study with a far larger sample size, and that these results should be viewed as suggestive, requiring confirmation in a future trial.

Controlled single-blind clinical evaluation of low-dose mammographic screen: film systems

International Nuclear Information System (INIS)

Sickles, E.A.; Genant, H.K.

1979-01-01

The ability of five low-dose mammographic screen-film systems to portray normal and abnormal breast structures was evaluated in parallel with a study of physical image properties. Single-blind evaluations of the visibility of normal breast architecture, mass lesions, and calcifications were made on the mammograms of 100 patients radiographed with each of the systems. There was increased noise and slightly poorer resolution of the faster recording systems, but there was no difference in final diagnostic impressions among the five systems. These results suggest that the faster systems will result in substantial dose reduction without sacrificing diagnostic accuracy

Tissue responses to low protracted doses of high LET radiations or photons: Early and late damage relevant to radio-protective countermeasures

Science.gov (United States)

Ainsworth, E. J.; Afzal, S. M. J.; Crouse, D. A.; Hanson, W. R.; Fry, R. J. M.

Early and late murine tissue responses to single or fractionated low doses of heavy charged particles, fission-spectrum neutrons or gamma rays are considered. Damage to the hematopoietic system is emphasized, but results on acute lethality, host response to challenge with transplanted leukemia cells and life-shortening are presented. Low dose rates per fraction were used in some neutron experiments. Split-dose lethality studies (LD 50/30) with fission neutrons indicated greater accumulation of injury during a 9 fraction course (over 17 days) than was the case for γ-radiation. When total doses of 96 or 247 cGy of neutrons or γ rays were given as a single dose or in 9 fractions, a significant sparing effect on femur CFU-S depression was observed for both radiation qualities during the first 11 days, but there was not an earlier return to normal with dose fractionation. During the 9 fraction sequence, a significant sparing effect of low dose rate on CFU-S depression was observed in both neutron and γ-irradiated mice. CFU-S content at the end of the fractionation sequence did not correlate with measured LD 50/30. Sustained depression of femur and spleen CFU-S and a significant thrombocytopenia were observed when a total neutron dose of 240 cGy was given in 72 fractions over 24 weeks at low dose rates. The temporal aspects of CFU-S repopulation were different after a single versus fractionated neutron doses. The sustained reduction in the size of the CFU-S population was accompanied by an increase in the fraction in DNA synthesis. The proliferation characteristics and effects of age were different for radial CFU-S population closely associated with bone, compared with the axial population that can be readily aspirated from the femur. In aged irradiated animals, the CFU-S proliferation/redistribution response to typhoid vaccine showed both an age and radiation effect. After high single doses of neutrons or γ rays, a significant age- and radiation-related deficiency

Medical and Psychiatric Effects of Long-Term Dependence on High Dose of tramadol.

Science.gov (United States)

El-Hadidy, Mohmed Adel; Helaly, Ahmed Mohamed Nabil

2015-04-01

Tramadol dependence has been studied recently after large-scale exposure. Although tramadol dependence has increased rapidly in Egypt since 2004, no studies have evaluated the effect of high dose long-term tramadol dependence. To address the chronic sequel of tramadol dependence over at least 5 years duration with a large dose (more than 675 mg/day, three tablets or more, each tablet of 225 mg). The study was aimed to check the physical and psychiatric status during tramadol dependence and 3 months after complete treatment. The present study was applied on 79 patients with single tramadol-dependence dose of 675 mg or more for 5 years or more. We examined the physical and psychological impact of tramadol abuse before and after 3 months of stoppage of the drug. The blood chemistry was nearly within normal parameters, although slight nonsignificant rise in liver enzymes was reported in some cases. Patients during tramadol dependence period were angry, hostile, and aggressive. On the other hand, after treatment the main problem observed was the significant increase in comorbid anxiety, depressive, and obsessive-compulsive symptoms, but no increase was found in psychotic symptoms. Tramadol-dependence dose was more important than duration of use in psychiatric illness. Tramadol dependence on high dose could be physically safe to some limit, but psychiatrically it has many side effects.

Single versus double dose praziquantel comparison on efficacy and Schistosoma mansoni re-infection in preschool-age children in Uganda

DEFF Research Database (Denmark)

Nalugwa, Allen; Nuwaha, Fred; Tukahebwa, Edridah Muheki

2015-01-01

BACKGROUND: Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel...... (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda. METHODOLOGY/PRINCIPAL FINDINGS: Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially...... all children were treated with a single standard oral dose 40 mg/kg body weight of PZQ. Two weeks later a second dose was administered to children in the double dose treatment arm. Side effects were monitored at 30 minutes to 24 hours after each treatment. Efficacy in terms of CRs and ERRs for the two...

Cyclosporine promotes the induction of thymic lymphomas in C57BL/6 mice initiated by a single dose of γ-radiation

International Nuclear Information System (INIS)

Yabu, Koji; Warty, V.S.; Gorelik, E.; Shinozuka, Hisashi

1991-01-01

We previously demonstrated that a single dose of γ-radiation (350 rads) was able to induce thymic lymphomas in C57BL mice when followed by promoting treatment with oral cyclosporine (CsA), a non-genotoxic immunosuppressant. We have now tested the efficacy of various doses of γ-radiation as an initiator of CsA promotion of the induction of thymic lymphomas in male C57BL mice. The effects of oral CsA on the splenic natural killer (NK) cell activity of non-irradiated and irradiated (400 rads, 1X) mice were tested by the standard 51 Cr release assays against YAC-1 cells. The cumulative incidence of thymic lymphomas induced by a single dose of γ-radiation at 100, 200, 400 and 600 rads were 10, 25, 63 and 75% respectively, after 42 weeks of CsA promotion. The splenic NK cell activity in non-irradiated mice given CsA for 4 weeks was twice as high as that in the control mice. CsA inhibited poly I:C-induced augmentation of the splenic NK cell activity. In mice given a single dose (400 rads) of γ-radiation and CsA for 4 weeks, a similar but reduced enhancement of the splenic NK cell activity as seen in non-irradiated mice was observed. These results indicate that the efficacy of CsA promotion in the induction of thymic lymphomas is dependent on the initiating doses of γ-radiation, and that CsA enhances host splenic NK cell activity during the early stage of tumor promotion. (author)

Bronchodilator Efficacy of Single Doses of Indacaterol in Japanese Patients with COPD: A Randomised, Double-Blind, Placebo-Controlled Trial

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Motokazu Kato

Full Text Available ABSTRACT: Background: Indacaterol is an investigational, novel, inhaled once-daily ultra-long-acting beta-2 agonist for the treatment of chronic obstructive pulmonary disease (COPD. This study evaluated the 24-h bronchodilatory efficacy and safety of indacaterol in Japanese patients with COPD. Methods: This Phase-II, randomised, placebo-controlled, crossover study comprised four double-blind, single-dose treatment periods (washout between periods: 14-28 days. Japanese patients aged 40-75 years with moderate-to-severe COPD were randomised to receive single doses of indacaterol (150, 300, or 600 μg or placebo via a single-dose dry-powder inhaler. Efficacy (primary endpoint: standardised FEV1AUC22-24h and safety were assessed for 24 h post-dose in each treatment period. Results: Of the 50 patients randomised (92% male; mean age, 67.2 years, 45 completed the study. Standardised FEV1AUC22-24h was significantly higher for all indacaterol doses as compared with placebo, with clinically relevant differences of 130, 160, and 170 mL for 150, 300, and 600 μg, respectively (P < 0.001. The improvement in FEV1 was seen as early as 5 min post-dose with indacaterol and sustained for 24 h (P < 0.001 vs placebo at all time points. All indacaterol doses were well tolerated and showed no clinically meaningful effect on pulse rate, blood pressure, QTc interval, and laboratory parameters when compared with placebo. Conclusions: In the Japanese COPD population studied, single doses of indacaterol (150, 300, and 600 μg provided sustained 24-h bronchodilation, with onset of action within 5 min post-dose. All doses were well tolerated. These results are consistent with data from Caucasian populations. KEY WORDS: beta2-agonists, bronchodilator, COPD, efficacy, indacaterol

Dose-dependent effect of a single GnRHa injection on the spawning of meagre (Argyrosomus regius broodstock reared in captivity

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Hipolito Fernandez-Palacios

2014-10-01

Full Text Available The present study aimed to determine the spawning efficacy, egg quality and quantity of captive breed meagre induced with a single gonadotrophin‐releasing hormone agonist (GnRHa injection of 0, 1, 5, 10, 15, 20, 25, 30, 40 or 50 µg kg-1 to determine a recommended optimum dose to induce spawning. The doses 10, 15 and 20 μg kg-1 gave eggs with the highest quality (measured as: percentage of viability, floating, fertilisation and hatch and quantity (measured as: total number of eggs, number of viable eggs, number of floating eggs, number of hatched larvae and number of larvae that reabsorbed the yolk sac. All egg quantity parameters were described by Gaussian regression analysis with R2=0.89 or R2=0.88. The Gaussian regression analysis identified that the optimal dose used was 15 μg kg-1. The regression analysis highlighted that this comprehensive study examined doses that ranged from low doses insufficient to stimulate a high spawning response (significantly lower egg quantities, p<0.05 compared to 15 μg kg-1 through to high doses that stimulated the spawning of significantly lower egg quantities and eggs with significantly lower quality (egg viability. In addition, the latency period (time from hormone application to spawning decreased with increasing doses to give a regression (R2=0.93 which suggests that higher doses accelerated oocyte development that in turn reduced egg quality and quantity. The identification of an optimal dose for the spawning of meagre, which has high aquaculture potential, represents an important advance for the Mediterranean aquaculture industry.

Endorectal high dose rate brachytherapy quality assurance

International Nuclear Information System (INIS)

Devic, S.; Vuong, T.; Evans, M.; Podgorsak, E.

2008-01-01

We describe our quality assurance method for preoperative high dose rate (HDR) brachytherapy of endorectal tumours. Reproduction of the treatment planning dose distribution on a daily basis is crucial for treatment success. Due to the cylindrical symmetry, two types of adjustments are necessary: applicator rotation and dose distribution shift along the applicator axis. (author)

Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer

International Nuclear Information System (INIS)

Martinez, Alvaro A.; Gustafson, Gary; Gonzalez, Jose; Armour, Elwood; Mitchell, Chris; Edmundson, Gregory; Spencer, William; Stromberg, Jannifer; Huang, Raywin; Vicini, Frank

2002-01-01

Purpose: To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed. Methods and Materials: Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level ≥10.0 ng/mL, Gleason score ≥7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose 93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure. Results: The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p<0.001). Improvement occurred in the cause-specific survival in favor of the brachytherapy high-dose level (p=0.014). On multivariate analysis, a low-dose level, higher Gleason score, and higher nadir value were associated with increased biochemical failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%. Conclusion: Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause

Efficacy of prophylactic single-dose therapy using fluoroquinolone for prostate brachytherapy

International Nuclear Information System (INIS)

Nomura, Takeo; Hirai, Kenichi; Yamasaki, Mutsushi; Inoue, Toru; Takahashi, Mika; Kawashima, Takayuki; Sato, Fuminori; Mimata, Hiromitsu

2012-01-01

There is little definitive evidence to guide the use of prophylactic antibiotics for prostate brachytherapy. The purpose of this study is to evaluate the incidence of postimplant infections in patients who receive antimicrobial prophylaxis with pazufloxacin (PZFX). A total of 84 patients who underwent prostate brachytherapy received a single intravenous dose of PZFX at 500 mg perioperatively for 1 day. No postimplant antibiotic medication was prescribed. Urinalysis, plasma white blood cell (WBC) count, and C reactive protein (CRP) levels were evaluated before the implantation, on the day after implantation, and on the 7th and 28th days after brachytherapy. None of the 84 patients (0.0%) developed a symptomatic urinary tract infection or had febrile infectious complications after brachytherapy. There were statistically significant elevations in the levels of erythrocytes, leukocytes, bacteria in urine, plasma WBC and CRP postoperatively, but these values did not exceed the normal range or were only slightly elevated on the day after brachytherapy (day 1) and on day 7. All laboratory examinations had returned to the normal range on day 28. Single-dose therapy with fluoroquinolone helps to prevent infections after prostate brachytherapy. (author)

Single dose total lymphoid irradiation combined with cyclophosphamide as immunosuppression for human marrow transplantation in aplastic anemia

International Nuclear Information System (INIS)

Kim, T.H.; Kersey, J.H.; Khan, F.M.; Sewchand, W.; Ramsey, N.; Krivit, W.; Coccia, P.; Nesbit, M.E.; Levitt, S.H.

1979-01-01

Six patients with aplastic anemia underwent bone marrow transplantation following conditioning with high dose cyclophosphamide and single dose total lymphoid irradiation with 750 rad, 26 rad/min at the midplane of the patient. They all received bone marrow from human leukocyte antigens/mixed lymphocyte culture (HLA/MLC) matched siblings. Five of 6 patients were alive without complications at 12, 11, 7, 4 and 4 months respectively. The remaining patient died from sepis which he had prior to transplantation. There were no graft rejection, graft-vs-Host Disease (GVHD) or interstitial pneumonitis among these patients. The procedure was well tolerated with minimal side effects. The results will be compared with those of groups whose bone marrow was previously transplanted with different immunosuppressive methods

Effect of single lithium doses on haemopoiesis regeneration after radiation exposure in mice

International Nuclear Information System (INIS)

Krajewski, K.

1988-01-01

The reported experiment failed to demonstrate any effect of single doses of lithium carbonate on haemopoiesis regeneration in experimental haematological syndrome of acute radiation sickness. The effects of gamma radiation on blood formation are shown. 3 figs., 6 refs. (author)

Fosfomycin trometamol: a review of its use as a single-dose oral treatment for patients with acute lower urinary tract infections and pregnant women with asymptomatic bacteriuria.

Science.gov (United States)

Keating, Gillian M

2013-11-01

Fosfomycin trometamol (fosfomycin tromethamine) [Monuril(®), Monurol(®), Monural(®)] is approved in numerous countries worldwide, mainly for the treatment of uncomplicated urinary tract infections (UTIs). Fosfomycin has good in vitro activity against common uropathogens, such as Escherichia coli (including extended-spectrum β-lactamase-producing E. coli), Proteus mirabilis, Klebsiella pneumoniae and Staphylococcus saprophyticus, and the susceptibility of uropathogens to fosfomycin has remained relatively stable over time. A single oral dose of fosfomycin trometamol 3 g (the approved dosage) achieves high concentrations in urine. Results of recent randomized trials indicate that single-dose fosfomycin trometamol had similar clinical and/or bacteriological efficacy to 3- to 7-day regimens of ciprofloxacin, norfloxacin, cotrimoxazole or nitrofurantoin in women with uncomplicated lower UTIs. In addition, single-dose fosfomycin trometamol had similar bacteriological efficacy to a 5-day course of cefuroxime axetil or a 7-day course of amoxicillin/clavulanic acid in pregnant women with asymptomatic bacteriuria, and similar clinical and/or bacteriological efficacy to a 5-day course of cefuroxime axetil or amoxicillin/clavulanic acid or a 3-day course of ceftibuten in pregnant women with a lower UTI. Single-dose fosfomycin trometamol was generally well tolerated, with gastrointestinal adverse events (e.g. diarrhoea, nausea) reported most commonly. In conclusion, single-dose fosfomycin trometamol is an important option for the first-line empirical treatment of uncomplicated lower UTIs.

Mechanistic and single-dose in vivo therapeutic studies of Cry5B anthelmintic action against hookworms.

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Yan Hu

Full Text Available Hookworm infections are one of the most important parasitic infections of humans worldwide, considered by some second only to malaria in associated disease burden. Single-dose mass drug administration for soil-transmitted helminths, including hookworms, relies primarily on albendazole, which has variable efficacy. New and better hookworm therapies are urgently needed. Bacillus thuringiensis crystal protein Cry5B has potential as a novel anthelmintic and has been extensively studied in the roundworm Caenorhabditis elegans. Here, we ask whether single-dose Cry5B can provide therapy against a hookworm infection and whether C. elegans mechanism-of-action studies are relevant to hookworms.To test whether the C. elegans invertebrate-specific glycolipid receptor for Cry5B is relevant in hookworms, we fed Ancylostoma ceylanicum hookworm adults Cry5B with and without galactose, an inhibitor of Cry5B-C. elegans glycolipid interactions. As with C. elegans, galactose inhibits Cry5B toxicity in A. ceylanicum. Furthermore, p38 mitogen-activated protein kinase (MAPK, which controls one of the most important Cry5B signal transduction responses in C. elegans, is functionally operational in hookworms. A. ceylanicum hookworms treated with Cry5B up-regulate p38 MAPK and knock down of p38 MAPK activity in hookworms results in hypersensitivity of A. ceylanicum adults to Cry5B attack. Single-dose Cry5B is able to reduce by >90% A. ceylanicum hookworm burdens from infected hamsters, in the process eliminating hookworm egg shedding in feces and protecting infected hamsters from blood loss. Anthelmintic activity is increased about 3-fold, eliminating >97% of the parasites with a single 3 mg dose (∼30 mg/kg, by incorporating a simple formulation to help prevent digestion in the acidic stomach of the host mammal.These studies advance the development of Cry5B protein as a potent, safe single-dose anthelmintic for hookworm therapy and make available the information of how

Pharmacokinetic Evaluation of a Single Intramuscular High Dose versus an Oral Long-Term Supplementation of Cholecalciferol.

Directory of Open Access Journals (Sweden)

Katharina Wylon

Full Text Available Vitamin D deficiency is frequent during the winter and occurs throughout the year in the elderly or patients suffering from autoimmune diseases. The objective of this study was to evaluate the pharmacokinetic properties of oral supplementation versus a single intramuscular injection of cholecalciferol in healthy individuals.Up to 8,000 I.U. oral cholecalciferol was administered daily for 84 days in a 4 week dose-escalation setting to vitamin D deficient individuals. In another cohort, a single intramuscular injection of 100,000 I.U. cholecalciferol was given. In both cohorts, individuals without vitamin D intake served as the comparison group. 25-hydroxyvitamin D (25(OHD concentrations were measured in all individuals at defined time points throughout the studies.The mean 25(OHD serum concentration increased significantly after oral cholecalciferol intake compared to the control group (day 28: 83.4 nmol/l and 42.5 nmol/l; day 56: 127.4 nmol/l and 37.3 nmol/l; day 84: 159.7 nmol/l and 30.0 nmol/l. In individuals receiving 100,000 I.U. cholecalciferol intramuscular, the mean 25(OHD serum concentration peaked after 4 weeks measuring 70.9 nmol/l compared to 32.7 nmol/l in the placebo group (p = 0.002. The increase of 25(OHD serum concentrations after 28 days was comparable between both routes of administration (p = 0.264.Oral and intramuscular cholecalciferol supplementation effectively increased serum 25(OHD concentrations.

High-dose erythropoietin in patients with progressive multiple sclerosis

DEFF Research Database (Denmark)

Schreiber, Karen; Magyari, Melinda; Sellebjerg, Finn

2017-01-01

BACKGROUND: Erythropoietin (EPO) is a part of an endogenous neuroprotective system in the brain and may address pathophysiological mechanisms in progressive multiple sclerosis (MS). OBJECTIVE: To evaluate a treatment effect of EPO on progressive MS. METHODS: This was a single-center, randomized......, double-blind, placebo-controlled phase 2 trial, in which 52 patients with secondary or primary progressive MS were allocated to treatment with recombinant EPO (48,000 IU) or placebo, administered intravenously 17 times during 24 weeks. Patients had an Expanded Disability Status Score (EDSS) from 4 to 6......: This study provides class II evidence that treatment with high-dose EPO is not an effective treatment in patients with moderately advanced progressive MS....

NIST high-dose calibration services

International Nuclear Information System (INIS)

Humphreys, J.C.

1989-01-01

There is a need for the standardization of high-dose measurements used in the radiation-processing industry in order to provide assured traceability to national standards. NIST provides dosimetry calibration services to this industry. One of these services involves administration of known absorbed doses of gamma rays to customer-supplied dosimeters. The dosimeters are packaged to provide electron equilibrium conditions and are irradiated in a standard 60 Co calibration facility; this provides a calibration of that batch of dosimeters. Another service consists of supplying to a customer calibrated transfer dosimeters for irradiation with the customer's radiation source. The irradiated transfer dosimeters are then returned to NIST for analysis; the results are reported to the customer, providing a calibration of the dose rate of the customer's source. (orig.)

Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer

International Nuclear Information System (INIS)

Oliveira, Jetro Pereira de; Batista, Delano Valdivino Santos; Bardella, Lucia Helena; Carvalho, Arnaldo Rangel

2009-01-01

Objective: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. Materials and methods: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. Results: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. Conclusion: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. (author)

Dose proportionality and pharmacokinetics of carvedilol sustained-release formulation: a single dose-ascending 10-sequence incomplete block study

Directory of Open Access Journals (Sweden)

Kim YH

2015-06-01

Full Text Available Yo Han Kim,1 Hee Youn Choi,1 Yook-Hwan Noh,1 Shi Hyang Lee,1 Hyeong-Seok Lim,1 Chin Kim,2 Kyun-Seop Bae11Department of Clinical Pharmacology and Therapeutics, College of Medicine, University of Ulsan, Asan Medical Center, 2Chong Kun Dang Clinical Research and Clinical Epidemiology and Medical Information, CKD Pharmaceuticals, Seoul, Republic of KoreaBackground: Carvedilol is a third-generation β-blocker indicated for congestive heart failure and high blood pressure. The aim of this study was to investigate the dose proportionality of the carvedilol sustained-release (SR formulation in healthy male subjects.Methods: An open-label, single dose-ascending, 10-sequence, 3-period balanced incomplete block study was performed using healthy male subjects. In varying sequences, each subject received three of five carvedilol SR formulations (8, 16, 32, 64, or 128 mg once. The treatment periods were separated by a washout period of 7 days. Serial blood samples were collected up to 48 h after dosing. The plasma concentrations of carvedilol were determined by using validated liquid chromatography–tandem mass spectrometry. Pharmacokinetic parameters including the area under the plasma concentration–time curve (AUC from time 0 to the last measurable time (AUClast, AUC extrapolated to infinity (AUCinf, and the measured peak plasma concentration (Cmax were obtained by noncompartmental analysis. Dose proportionality was evaluated if the ln–ln plots of AUClast, AUCinf, and Cmax versus dose were linear and the 90% confidence intervals (CIs of the slopes were within 0.9195 and 1.0805. Tolerability was assessed by vital signs, electrocardiogram, clinical laboratory tests, and monitoring of adverse events (AEs throughout the study.Results: A total of 31 subjects were enrolled, and 30 completed the study. The assessment of dose proportionality meets the statistical criteria; the point estimates of slope were 1.0104 (90% CI: 0.9849–1.0359 for AUClast, 1

The Effect of Nicotine Administration on Physical and Psychological Signs of Withdrawal Syndrome Induced by Single or Frequent Doses of Morphine in Rats

OpenAIRE

Mohammad Allahtavakoli; Fatemeh Amin; Elham Hakimizadeh; Ali Roohbakhsh; Sayed Ali Haeri Rohani; Ahmad Taghavi Rafsanjani; Abbas Haghparast; Ali Shamsizadeh

2012-01-01

Introduction. Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Materials and methods. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later t...

Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer.

Science.gov (United States)

Martinez, Alvaro A; Gustafson, Gary; Gonzalez, José; Armour, Elwood; Mitchell, Chris; Edmundson, Gregory; Spencer, William; Stromberg, Jannifer; Huang, Raywin; Vicini, Frank

2002-06-01

To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed. Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level >or=10.0 ng/mL, Gleason score >or=7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose 93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure. The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%. Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause-specific survival with higher doses. These results, coupled with the low risk of complications, the advantage of not being radioactive after implantation, and the real-time interactive planning, define a new standard for treatment.

Radiation hardening at 77 K in Zn and Cu single crystals at low doses

International Nuclear Information System (INIS)

Gonzalez, H.C.; Bisogni, E.A.

1980-01-01

There is controversy about radiation hardening phenomenon and its additivity with other hardening mechanisms. The purpose of this work is to contribute to the understanding of this subject, through measurements made in Zn and Cu single crystals. Post-irradiation measurements of yield stress of Zn, made on different single crystals, show a direct proportionality to the 0.5 power of the dose. It is determined that for a dose greater than 3.7 x 10 16 neutrons cm -2 s -1 there is always cleavage. The maximum critical resolved shear stress measured is about 8.82 MPa. In order to study additivity it is necessary to lower experimental errors. A micro tensile machine is designed to operate in the CNEA facility RA1 in a bath of liquid N 2 . Experimental measurements of yield stress with dose are carried out in-situ on the same single crystals. Experimental results on Cu and Zn show that radiation induced yield stress increases with a 0.5 power law. It must be taken into account that the definition of radiation induced yield stress stands for radiation created obstacles operating alone. The radiation induced yield stress adds algebraically to the athermal component of the initial yield stress but is not exactly additive to the other thermally activated mechanisms. A gradual transition from one to the other type of obstacles is observed. (author)

Pharmacokinetics of a telmisartan/rosuvastatin fixed-dose combination: a single-dose, randomized, open-label, 2-period crossover study in healthy Korean subjects.

Science.gov (United States)

Chae, Dong Woo; Son, Mijeong; Kim, Yukyung; Son, Hankil; Jang, Seong Bok; Seo, Jeong Min; Nam, Su Youn; Park, Kyungsoo

2015-10-01

As hypertension and dyslipidemia are frequent comorbidities, antihypertensive drugs and lipid-lowering agents are often prescribed together for their treatment. Telmisartan and rosuvastatin are widely used together to treat hypertension and dyslipidemia. A combination formulation of these two drugs would improve patient compliance due to ease of dosing. The purpose of this study was to assess bioequivalence of single-dose administration of a newly-developed fixed-dose combination (FDC) tablet containing telmisartan/rosuvastatin 80/20 mg (test treatment) and coadministration of a telmisartan 80-mg tablet and a rosuvastatin 20-mg tablet (reference treatment) in healthy Korean male volunteers. This was a single-dose, randomized, open-label, 2-period crossover study enrolling healthy males aged 20 - 50 years with BMI between 18.5 and 25 kg/m2. Each subject received a single dose of the reference and test treatments with a 14-day washout period. Blood sampling was performed at prespecified intervals for up to 72 hours after dosing. Primary pharmacokinetic parameters were Cmax, AUClast, and AUC0-∞ of telmisartan, rosuvastatin, and N-desmethyl rosuvastatin. Bioequivalence was assessed by determining whether the 90% confidence intervals (CIs) of the geometric mean ratios (test treatment/reference treatment) of these parameters were within the standard range of 80% to 125%. Adverse events were monitored via regular interviews with the subjects and by physical examinations. 60 subjects were enrolled and 55 completed the study. The 90% CIs of the geometric mean ratios of Cmax, AUClast, and AUC00-∞ were 0.9262-1.1498, 0.9294-1.0313, and 0.9312-1.0320 for telmisartan, 0.9041-1.0428, 0.9262-1.0085, and 0.9307-1.0094 for rosuvastatin, and 0.8718-1.0022, 0.8901-0.9904, and 0.8872-0.9767 for N-desmethyl rosuvastatin, respectively. There was no statistical difference in the incidence of adverse events (AEs) (all of which were mild or moderate) between the reference and test

Intravenous iron isomaltoside 1000 administered by high single-dose infusions or standard medical care for the treatment of fatigue in women after postpartum haemorrhage: study protocol for a randomised controlled trial.

Science.gov (United States)

Holm, Charlotte; Thomsen, Lars Lykke; Norgaard, Astrid; Langhoff-Roos, Jens

2015-01-14

Postpartum haemorrhage can lead to iron deficiency with and without anaemia, the clinical consequences of which include physical fatigue. Although oral iron is the standard treatment, it is often associated with gastrointestinal side effects and poor compliance. To date, no published randomised controlled studies have compared the clinical efficacy and safety of standard medical care with intravenous administration of iron supplementation after postpartum haemorrhage.The primary objective of this study is to compare the efficacy of an intravenous high single-dose of iron isomaltoside 1000 with standard medical care on physical fatigue in women with postpartum haemorrhage. In a single centre, open-labelled, randomised trial, women with postpartum haemorrhage exceeding 700 mL will be allocated to either a single dose of 1,200 mg of iron isomaltoside 1000 or standard medical care. Healthy parturients with a singleton pregnancy will be included within 48 hours after delivery.Participants will complete structured questionnaires that focus on several dimensions of fatigue and mental health (Multidimensional Fatigue Inventory, Edinburgh Postnatal Depression Scale and the Postpartum Questionnaire), at inclusion and at follow-up visits after three days, one week, three weeks, eight weeks, and 12 weeks postpartum. The primary endpoint is the aggregated change in physical fatigue score within 12 weeks postpartum, as measured by a subscale of the Multidimensional Fatigue Inventory. The primary objective will be considered to have been met if an intravenous high single dose of iron isomaltoside 1000 is shown to be superior to standard medical care in women after postpartum haemorrhage regarding physical fatigue.For claiming superiority, we set the minimal clinically relevant difference between the mean scores at 1.8, and the assumed standard deviation at 4.2. Hence, 87 participants per treatment group are needed in order to demonstrate superiority; to provide an extra margin

Investigation of polymer composite for high dose dosimetry

International Nuclear Information System (INIS)

Pereira, E.L.M.; Batista, A.S.M.; Ribeiro, F.A.S.; Santos, A.P.; Faria, L.O.; Oliveira, A.H.

2017-01-01

Introduction: This paper presents the efficacy evaluation of PVDF and nanocomposites of the PVDF films for high gamma dosimetry. Our scope in this first part of our studies is the selection of the most promising film for future dosimetry trials, where the proportionality of response of the selected material will be investigated over a large range of doses and dose rates. Methods: Was prepared nanocomposites made by mixing Poly(vinylidene fluoride) (PVDF), zirconium oxide (ZrO 2 ) and multi-walled carbon nanotubes (MWCNTs) aiming to find dosimetric properties for applications in high dose dosimetry. The samples were irradiated with a Co-60 source at constant dose rate (16.7 kGy/h), with doses ranging from 100 to 2750 kGy. The UV-Vis and FTIR spectrophotometry have been used to monitor the appearing of C=C conjugated bonds and radio-oxidation of carbon (C=O). Results: FTIR spectrometry has that the absorbance intensities at 1715 cm -1 and 1730 cm -1 can be used for high dosimetry purposes for gamma doses ranging from 400 to 2750 kGy. In this range, it is possible to observe a linear relationship between Abs & Dose. Fading of signal was evaluated for one month and reproducibility in 2000 kGy dose. Conclusion: FTIR spectroscopic data revealed two optical absorption bands at 1715 cm -1 and 1730 cm -1 whose intensities are unambiguously related to gamma delivered dose ranging from 400 kGy to 2750 kGy. (author)

Pharmacokinetics of [14C]teicoplanin in male rats after single intravenous dose

International Nuclear Information System (INIS)

Bernareggi, A.; Cavenaghi, L.; Assandri, A.

1986-01-01

The pharmacokinetic profile of [ 14 C]teicoplanin was studied in male Sprague-Dawley rats given a single 10,000-U/kg intravenous dose. The disposition of the antimicrobial activity in the body was estimated by a three-compartment open model. Plasma concentration data were fitted to a three-exponent equation. The profile of total 14 C in plasma was similar to that of the microbiological activity. The cumulative recovery of total 14 C 5 days after drug administration averaged 76.3% of the administered dose in the urine and 8.7% in the feces. The residual dose remaining in the animal carcasses was 11.1%. Teicoplanin was widely distributed in the body. In almost all organs, the maximum concentration of [ 14 C]teicoplanin was already reached at the first time of killing, which was 0.25 h after the administration of drug. The liver, kidneys, skin, and fat contained most of the residual dose found in the animal carcasses 120 h after administration and behaved as a deep compartment with the adrenal glands and spleen

Misonidazole cytotoxicity in vivo: a comparison of large single doses with smaller doses and extended contact of the drug with tumor cells

International Nuclear Information System (INIS)

Conroy, P.J.; Sutherland, R.M.; Passalacqua, W.

1980-01-01

Experiments were performed to determine the kinetics and magnitude of misonidazole cytotoxicity in EMT6/Ro tumors using an in vivo-in vitro clonogenicity assay. A comparison was made between the cytotoxic effects of large single doses with smaller doses of misonidazole administered ip and those produced on extended contact of the drug with tumor cells using a continuous iv drug infusion system. After a single ip dose of 1 mg/g, cytotoxicity was maximum at 18 to 24 h; by 72 h the clonogenic cells per tumor had returned to control levels. The maximum cytotoxicity was greater (a decrease of 10 times) if the animals were kept at 37 0 C compared with ambient conditions (a decrease of 4.5 times) where the body temperature would decrease due to the drug. A dose-response curve performed with the animals at 37 0 C showed no significant cytotoxicity at 18 h after single ip doses of 0.5 mg/g or less. Other experiments were carried out at 37 0 C using a drug continuous infusion system. Two profiles were studied: (a) continuous constant rate infusion over 3 days of constant serum and tumor levels of both 100 and 200 μg/ml and (b) continuous variable rate infusion where the maximum serum levels reached 80 or 200 μg/ml after 2 to 4 h and decayed with a half-life of 12 h as in humans. Significant cytotoxicity was obtained under both of these conditions. Maximum cytotoxicity occurred at about 24 h in both types of experiments and amounted to decreases of clonogenic tumor cells of 4.5 and 7 times for 100 and 200 μg/ml, respectively, after constant rate infusion and 2 to 4 times for 80 and 200 μg/ml, respectively, after variable rate infusion. Because of the relatively rapid recovery in the number of clonogenic tumor cells by 72 h, the cytotoxic effects were not reflected as changes in tumor size even when the animals were maintained at 37 0 C

Statistical behavior of high doses in medical radiodiagnosis

International Nuclear Information System (INIS)

Barboza, Adriana Elisa

2014-01-01

This work has as main purpose statistically estimating occupational exposure in medical diagnostic radiology in cases of high doses recorded in 2011 at national level. For statistical survey of this study, doses of 372 IOE's diagnostic radiology in different Brazilian states were evaluated. Data were extracted from the work of monograph (Research Methodology Of High Doses In Medical Radiodiagnostic) that contains the database's information Sector Management doses of IRD/CNEN-RJ, Brazil. The identification of these states allows the Sanitary Surveillance (VISA) responsible, becomes aware of events and work with programs to reduce these events. (author)

Study of teflon pads as high doses dosemeters

International Nuclear Information System (INIS)

Teixeira, Maria Ines; Caldas, Linda V.E.

2013-01-01

The aim of this work is to study the Teflon, which is used as a binder in the manufacture of dosimetric tablets, for the feasibility of this material as high dose dosemeter. In this paper we used the technique of thermally stimulated luminescence (OSL) to characterize the dosimetric properties of Teflon. Teflon samples were exposed to different doses of radiation, using a source of gamma radiation ( 60 Co). It was obtained dose-response curve between 100 Gy to 50 kGy and reproducibility of OSL response. The preliminary results show that Teflon is a useful material to high dose dosimetry

Long-Term Results After High-Dose Radiotherapy and Adjuvant Hormones in Prostate Cancer: How Curable Is High-Risk Disease?

Energy Technology Data Exchange (ETDEWEB)

Zapatero, Almudena, E-mail: azapatero.hlpr@salud.madrid.org [Department of Radiation Oncology, Hospital Universitario de la Princesa, Madrid (Spain); Garcia-Vicente, Feliciano [Department of Medical Physics, Hospital Universitario de la Princesa, Madrid (Spain); Martin de Vidales, Carmen; Cruz Conde, Alfonso; Ibanez, Yamile [Department of Radiation Oncology, Hospital Universitario de la Princesa, Madrid (Spain); Fernandez, Inmaculada; Rabadan, Mariano [Department of Urology, Hospital Universitario de la Princesa, Madrid (Spain)

2011-12-01

Purpose: To analyze long-term outcome and prognostic factors for high-risk prostate cancer defined by National Comprehensive Cancer Network criteria treated with high-dose radiotherapy and androgen deprivation in a single institution. Methods and Materials: A total of 306 patients treated between 1995 and 2007 in a radiation dose-escalation program fulfilled the National Comprehensive Cancer Network high-risk criteria. Median International Commission on Radiation Units and Measurements radiation dose was 78 Gy (range, 66.0-84.1 Gy). Long-term androgen deprivation (LTAD) was administered in 231 patients, short-term androgen deprivation (STAD) in 59 patients, and no hormones in 16 patients. The Phoenix (nadir plus 2 ng/mL) consensus definition was used for biochemical control. Multivariate analysis was performed to determine the independent prognostic impact of clinical and treatment factors. Median follow-up time was 64 months (range, 24-171 months). Results: The actuarial overall survival at 5 and 10 years was 95.7% and 89.8%, respectively, and the corresponding biochemical disease-free survival (bDFS) was 89.5% and 67.2%, respectively. Fourteen patients (4.6%) developed distant metastasis. Multivariate analysis showed that Gleason score >7 (p = 0.001), pretreatment prostate-specific antigen (PSA) level >20 ng/mL (p = 0.037), higher radiation dose (p = 0.005), and the use of adjuvant LTAD vs. STAD (p = 0.011) were independent prognostic factors affecting bDFS in high-risk disease. The 5-year bDFS for patients treated with LTAD plus radiotherapy dose >78 Gy was 97%. Conclusions: For high-risk patients the present series showed that the use of LTAD in conjunction with higher doses (>78 Gy) of radiotherapy was associated with improved biochemical tumor control. We observed that the presence of Gleason sum >7 and pretreatment PSA level >20 ng/mL in the same patient represents a 6.8 times higher risk of PSA failure. These men could be considered for clinical trials with

High doses of dextromethorphan, an NMDA antagonist, produce effects similar to classic hallucinogens

Science.gov (United States)

Carter, Lawrence P.; Johnson, Matthew W.; Mintzer, Miriam Z.; Klinedinst, Margaret A.; Griffiths, Roland R.

2013-01-01

Rationale Although reports of dextromethorphan (DXM) abuse have increased recently, few studies have examined the effects of high doses of DXM. Objective This study in humans evaluated the effects of supratherapeutic doses of DXM and triazolam. Methods Single, acute, oral doses of DXM (100, 200, 300, 400, 500, 600, 700, 800 mg/70 kg), triazolam (0.25, 0.5 mg/70kg), and placebo were administered to twelve healthy volunteers with histories of hallucinogen use, under double-blind conditions, using an ascending dose run-up design. Subjective, behavioral, and physiological effects were assessed repeatedly after drug administration for 6 hours. Results Triazolam produced dose-related increases in subject-rated sedation, observer-rated sedation, and behavioral impairment. DXM produced a profile of dose-related physiological and subjective effects differing from triazolam. DXM effects included increases in blood pressure, heart rate, and emesis, increases in observer-rated effects typical of classic hallucinogens (e.g. distance from reality, visual effects with eyes open and closed, joy, anxiety), and participant ratings of stimulation (e.g. jittery, nervous), somatic effects (e.g. tingling, headache), perceptual changes, end-of-session drug liking, and mystical-type experience. After 400 mg/70kg DXM, 11 of 12 participants indicated on a pharmacological class questionnaire that they thought they had received a classic hallucinogen (e.g. psilocybin). Drug effects resolved without significant adverse effects by the end of the session. In a 1-month follow up volunteers attributed increased spirituality and positive changes in attitudes, moods, and behavior to the session experiences. Conclusions High doses of DXM produced effects distinct from triazolam and had characteristics that were similar to the classic hallucinogen psilocybin. PMID:22526529

Effects of food intake on the pharmacokinetics of diclofenac potassium soft gelatin capsules: a single-dose, randomized, two-way crossover study.

Science.gov (United States)

Scallion, Ralph; Moore, Keith A

2009-10-01

Diclofenac potassium liquid-filled soft gelatin capsule (DPSGC) is an investigational formulation that uses dispersing agents designed to facilitate rapid and consistent absorption of this NSAID. The aim of this study was to characterize the effects of food intake on the pharmacokinetic (PK) profile of oral DPSGC at doses of 25 and 50 mg. In this open-label, randomized, single-dose (2 distinct doses), 2-way crossover bioavailability study, healthy adult volunteers were randomly assigned to receive a single dose of DPSGC 25 or 50 mg after an overnight fast (fasted condition) or high-fat breakfast (fed condition) (period 1). After 7 days, the participants received the same dose under the opposite fed/fasted condition (period 2). Serial blood samples were obtained before and through 6 hours after study drug administration. Concentrations of diclofenac in plasma were determined using HPLC, and PK profiles were studied using ANCOVA. Adverse events (AEs) were monitored and recorded on each in-clinic day. Of 47 participants included in the study, 24 received the 25-mg dose of DPSGC and 23 received the 50-mg dose. The majority of participants were male (80.9%), and the mean age was 28.6 years. The mean (SD) AUC values for the fasted and fed states were 691 (195) and 680 (184) ng x h/mL, respectively, with the 25-mg dose, and 1521 (377) and 1416 (366) ng . h/mL, respectively, with the 50-mg dose, suggesting that the extent of absorption was similar with both dietary conditions at each dose. Food intake was associated with decreases in C(max) by nearly half in the 25-mg group (fasted vs fed, 1156 [482] vs 686 [411] ng/mL, respectively; P < 0.05) and the 50-mg group (2365 [1034] vs 1154 [592 ng/mL; P < 0.05) and delayed T(max) in the 25-mg group (0.49 [0.16] vs 1.02 [0.55] hours; P < 0.05) and 50-mg group (0.51 [0.19] vs 1.28 [0.71] hours; P < 0.05). Two mild AEs (nasal congestion and light-headedness) were reported in 2 participants who received 25 mg under fed conditions

Ionization chamber for high dose measurements

International Nuclear Information System (INIS)

Rodrigues Junior, Ary de Araujo

2005-01-01

Industrial gamma irradiators facilities are designed for processing large amounts of products, which are exposed to large doses of gamma radiation. The irradiation, in industrial scale, is usually carried out in a dynamic form, where the products go through a 60 Co gamma source with activity of TBq to P Bq (k Ci to MCi). The dose is estimated as being directly proportional to the time that the products spend to go through the source. However, in some situations, mainly for research purposes or for validation of customer process following the ISO 11137 requirements, it is required to irradiate small samples in a static position with fractional deliver doses. The samples are put inside the irradiation room at a fixed distance from the source and the dose is usually determined using dosimeters. The dose is only known after the irradiation, by reading the dosimeter. Nevertheless, in the industrial irradiators, usually different kinds of products with different densities go through between the source and the static position samples. So, the dose rate varies in function of the product density. A suitable methodology would be to monitor the samples dose in real time, measuring the dose on line with a radiation detector, which would improve the dose accuracy and avoid the overdose. A cylindrical ionization chamber of 0.9 cm 3 has been developed for high-doses real-time monitoring, during the sample irradiation at a static position in a 60 Co gamma industrial plant. Nitrogen and argon gas at pressure of 10 exp 5 Pa (1 bar) was utilized to fill the ionization chamber, for which an appropriate configuration was determined to be used as a detector for high-dose measurements. To transmit the signal generated in the ionization chamber to the associated electronic and processing unit, a 20 m mineral insulated cable was welded to the ionization chamber. The signal to noise ratio produced by the detector was about 100. The dosimeter system was tested at a category I gamma

Development of computerized dose planning system and applicator for high dose rate remote afterloading irradiation

Energy Technology Data Exchange (ETDEWEB)

Choi, T. J. [Keimyung Univ., Taegu (Korea); Kim, S. W. [Fatima Hospital, Taegu (Korea); Kim, O. B.; Lee, H. J.; Won, C. H. [Keimyung Univ., Taegu (Korea); Yoon, S. M. [Dong-a Univ., Pusan (Korea)

2000-04-01

To design and fabricate of the high dose rate source and applicators which are tandem, ovoids and colpostat for OB/Gyn brachytherapy includes the computerized dose planning system. Designed the high dose rate Ir-192 source with nuclide atomic power irradiation and investigated the dose characteristics of fabricated brachysource. We performed the effect of self-absorption and determining the gamma constant and output factor and determined the apparent activity of designed source. he automated computer planning system provided the 2D distribution and 3D includes analysis programs. Created the high dose rate source Ir-192, 10 Ci(370GBq). The effective attenuation factor from the self-absorption and source wall was examined to 0.55 of the activity of bare source and this factor is useful for determination of the apparent activity and gamma constant 4.69 Rcm{sup 2}/mCi-hr. Fabricated the colpostat was investigated the dose distributions of frontal, axial and sagittal plane in intra-cavitary radiation therapy for cervical cancer. The reduce dose at bladder and rectum area was found about 20 % of original dose. The computerized brachytherapy planning system provides the 2-dimensional isodose and 3-D include the dose-volume histogram(DVH) with graphic-user-interface mode. emoted afterloading device was built for experiment of created Ir-192 source with film dosimetry within {+-}1 mm discrepancy. 34 refs., 25 figs., 11 tabs. (Author)

Single oral dose toxicity test of platycodin d, a saponin from platycodin radix in mice.

Science.gov (United States)

Lee, Won-Ho; Gam, Cheol-Ou; Ku, Sae-Kwang; Choi, Seong-Hun

2011-12-01

The object of this study was to evaluate the single oral dose toxicity of platycodin D, a saponin from the root of Platycodon grandiflorum in male and female mice. Platycodin D was administered to female and male mice as an oral dose of 2000, 1000, 500, 250 and 125 mg/kg (body wt.). Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after treatment, upon necropsy, organ weight and histopathology of 14 principle organs were examined. As the results, no platycodin D treatment related mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations against 14 principle organs were detected up to 2000 mg/kg in both female and male mice. Therefore, LD50 (50% lethal dose) and approximate LD of playtcodin D after single oral treatment in female and male mice were considered over 2000 mg/kg - the limited dosages recommended by KFDA Guidelines [2009-116, 2009], respectively.

Efficacy of different I-131 doses for thyroid remnant ablation

International Nuclear Information System (INIS)

Nguyen, X.C.; Thiep, T.V.; Hung, N.C.

2007-01-01

Full text: Radioactive iodine 131 I has been widely used as a treatment modality of differentiated thyroid carcinoma. The need for high dose radioiodine ablation of thyroid remnant is still in question. The aim of this prospective study was to assess the efficacy of 131 I different single and fractionated doses in ablation of post-operative thyroid remnant. Patients and methods: One hundred-twelve patients were included in this study. Sixty-one patients with TSH≥30 μU/ml were treated 30 mCi in group 1 (36 patients) or 100 mCi in group 2 (25 patients). Fifty one patients with TSH 131 I high dose of 100 mCi and no severe adverse effect in the other groups. Conclusion: Single high dose (100 mCi) may be more efficient than single low dose (30 mCi) for post-operative remnant ablation with serum TSH≥30 μU/ml and the efficacy of low fractionated doses (30+30 mCi) was comparable with high-fractionated dose (30+100 mCi) for post-operative remnant ablation with low serum TSH in differentiated thyroid carcinoma. (author)

[Safety Evaluation of Rare Sugar Syrup: Single-dose Oral Toxicity in Rats, Reverse Mutation Assay, Chromosome Aberration Assay, and Acute Non-Effect Level for Diarrhea of a Single Dose in Humans].

Science.gov (United States)

Yamada, Takako; Iida, Tetsuo; Takamine, Satoshi; Hayashi, Noriko; Okuma, Kazuhiro

2015-01-01

The safety of rare sugar syrup obtained from high-fructose corn syrup under slightly alkaline conditions was studied. Mutagenicity of rare sugar syrup was assessed by a reverse mutation assay using Salmonella typhimurium and Escherichia coli, and an in vitro chromosomal aberration assay using Chinese hamster lung cell line (CHL/IU). No mutagenicity of rare sugar syrup was detected under these experimental conditions. Oral administration of single dose (15,000 mg/kg) of rare sugar syrup to rats caused no abnormalities, suggesting no adverse effect of rare sugar syrup. In humans, the acute non-effect level of rare sugar syrup for causing diarrhea was estimated as 0.9 g/kg body weight as dry solid base in both males and females.

Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses

International Nuclear Information System (INIS)

Doerr, W.; Kummermehr, J.

1990-01-01

Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered. (author). 18 refs.; 7 figs.; 1 tab

Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

DEFF Research Database (Denmark)

Bøtter-Jensen, L.; Solongo, S.; Murray, A.S.

2000-01-01

We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks acid unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient...... dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only...

Population pharmacokinetics of artesunate and dihydroartemisinin following single- and multiple-dosing of oral artesunate in healthy subjects

Directory of Open Access Journals (Sweden)

Kirsch Lee E

2009-12-01

Full Text Available Abstract Background The population pharmacokinetics of artesunate (AS and its active metabolite dihydroartemisinin (DHA were studied in healthy subjects receiving single- or multiple-dosing of AS orally either in combination with pyronaridine (PYR or as a monotherapy with or without food. Methods Data from 118 concentration-time profiles arising from 91 healthy Korean subjects were pooled from four Phase I clinical studies. Subjects received 2-5 mg/kg of single- and multiple-dosing of oral AS either in combination with PYR or as a monotherapy with or without food. Plasma AS and DHA were measured simultaneously using a validated liquid chromatography- mass spectrometric method with a lower limit of quantification of 1 ng/mL for both AS and DHA. Nonlinear mixed-effect modelling was used to obtain the pharmacokinetic and variability (inter-individual and residual variability parameter estimates. Results A novel parent-metabolite pharmacokinetic model consisting of a dosing compartment, a central compartment for AS, a central compartment and a peripheral compartment for DHA was developed. AS and DHA data were modelled simultaneously assuming stoichiometric conversion to DHA. AS was rapidly absorbed with a population estimate of absorption rate constant (Ka of 3.85 h-1. The population estimates of apparent clearance (CL/F and volume of distribution (V2/F for AS were 1190 L/h with 36.2% inter-individual variability (IIV and 1210 L with 57.4% IIV, respectively. For DHA, the population estimates of apparent clearance (CLM/F and central volume of distribution (V3/F were 93.7 L/h with 28% IIV and 97.1 L with 30% IIV, respectively. The population estimates of apparent inter-compartmental clearance (Q/F and peripheral volume of distribution (V4/F for DHA were 5.74 L/h and 18.5 L, respectively. Intake of high-fat and high-caloric meal prior to the drug administration resulted in 84% reduction in Ka. Body weight impacted CLM/F, such that a unit change in

Pharmacogenetics and Pharmacokinetics in high-dose alkylating chemotherapy

NARCIS (Netherlands)

Ekhart, G.C. (Corine)

2008-01-01

High-dose chemotherapy in combination with peripheral blood progenitor cell transplantation has been developed as a possible curative treatment modality in several solid tumours. A frequently used high-dose regimen in the Netherlands is the CTC regimen, which is a 4-day course of cyclophosphamide,

Single dose oral flurbiprofen for acute postoperative pain in adults

Science.gov (United States)

Sultan, Asquad; McQuay, Henry J; Moore, R Andrew; Derry, Sheena

2014-01-01

Background Flurbiprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID), related to ibuprofen and naproxen, used to treat acute and chronic painful conditions. There is no systematic review of its use in acute postoperative pain. Objectives To assess efficacy, duration of action, and associated adverse events of single dose oral flurbiprofen in acute postoperative pain in adults. Search methods We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to January 2009. Selection criteria Randomised, double blind, placebo-controlled trials of single dose orally administered flurbiprofen in adults with moderate to severe acute postoperative pain. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk (RR) and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected. Main results Eleven studies compared flurbiprofen (699 participants) with placebo (362 participants) in studies lasting 6 to 12 hours. Studies were of adequate reporting quality, and most participants had pain following dental extractions. The dose of flurbiprofen used was 25 mg to 100 mg, with most information for 50 mg and 100 mg. The NNT for at least 50% pain relief over 4 to 6 hours for flurbiprofen 50 mg compared with placebo (692 participants) was 2.7 (2.3 to 3.3) and for 100 mg (416 participants) it was 2.5 (2.0 to 3.1). With flurbiprofen 50 mg and 100 mg 65% to 70% of participants experienced at least 50% pain relief, compared with 25% to 30% with placebo. Rescue medication was used by 25

Establishment and verification of dose-response curve of chromosomal aberrations after exposure to very high dose γ-ray

International Nuclear Information System (INIS)

Chen Ying; Luo Yisheng; Cao Zhenshan; Liu Xiulin

2006-01-01

To estimate accurately biological dose of the victims exposed to high dose, the dose-response curves of chromosome aberration induced by 6-22 Gy 60 Co γ-ray were established. Human peripheral blood in vitro was irradiated, then lymphocytes were concentrated, cultured 52h, 68h and 72h and harvested. The frequencies of dicentrics (multi-centrics) and rings were counted and compared between different culture times. The dose-response curves and equations were established, as well as verified with high dose exposure accidents. The experiment showed that the culture time should be prolonged properly after high dose exposure, and no significant differences were observed between 52-72h culture. The dose-response curve of 6-22 Gy fitted to linear-square model Y=-2.269 + 0.776D - 7.868 x 10 -3 D 2 and is reliable through verification of the accident dose estimations. In this study, the dose-response curve and equation of chromosome dic + r after 6-22 Gy high dose irradiation were established firstly, and exact dose estimation can be achieved according to it. (authors)

Nonlinear model of high-dose implantation

International Nuclear Information System (INIS)

Danilyuk, A.

2001-01-01

The models of high-dose implantation, using the distribution functions, are relatively simple. However, they must take into account the variation of the function of distribution of the implanted ions with increasing dose [1-4]. This variation takes place owing to the fact that the increase of the concentration of the implanted ions results in a change of the properties of the target. High-dose implantation is accompanied by sputtering, volume growth, diffusion, generation of defects, formation of new phases, etc. The variation of the distribution function is determined by many factors and is not known in advance. The variation within the framework of these models [1-4] is taken into account in advance by the introduction of intuitive assumptions on the basis of implicit considerations. Therefore, these attempts should be regarded as incorrect. The model prepared here makes it possible to take into account the sputtering of the target, volume growth and additional declaration on the implanted ions. Without any assumptions in relation to the variation of the distribution function with increasing dose. In our model it is assumed that the type of distribution function for small doses in a pure target substance is the same as in substances with implanted ions. A second assumption relates to the type of the distribution function valid for small doses in the given substances. These functions are determined as a result of a large number of theoretical and experimental investigations and are well-known at the present time. They include the symmetric and nonsymmetric Gauss distribution, the Pearson distribution, and others. We examine implantation with small doses of up to 10 14 - 10 15 cm -2 when the accurately known distribution is valid

Monte Carlo uncertainty analysis of dose estimates in radiochromic film dosimetry with single-channel and multichannel algorithms.

Science.gov (United States)

Vera-Sánchez, Juan Antonio; Ruiz-Morales, Carmen; González-López, Antonio

2018-03-01

To provide a multi-stage model to calculate uncertainty in radiochromic film dosimetry with Monte-Carlo techniques. This new approach is applied to single-channel and multichannel algorithms. Two lots of Gafchromic EBT3 are exposed in two different Varian linacs. They are read with an EPSON V800 flatbed scanner. The Monte-Carlo techniques in uncertainty analysis provide a numerical representation of the probability density functions of the output magnitudes. From this numerical representation, traditional parameters of uncertainty analysis as the standard deviations and bias are calculated. Moreover, these numerical representations are used to investigate the shape of the probability density functions of the output magnitudes. Also, another calibration film is read in four EPSON scanners (two V800 and two 10000XL) and the uncertainty analysis is carried out with the four images. The dose estimates of single-channel and multichannel algorithms show a Gaussian behavior and low bias. The multichannel algorithms lead to less uncertainty in the final dose estimates when the EPSON V800 is employed as reading device. In the case of the EPSON 10000XL, the single-channel algorithms provide less uncertainty in the dose estimates for doses higher than four Gy. A multi-stage model has been presented. With the aid of this model and the use of the Monte-Carlo techniques, the uncertainty of dose estimates for single-channel and multichannel algorithms are estimated. The application of the model together with Monte-Carlo techniques leads to a complete characterization of the uncertainties in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Antimalarial iron chelator, FBS0701, shows asexual and gametocyte Plasmodium falciparum activity and single oral dose cure in a murine malaria model.

Directory of Open Access Journals (Sweden)

Patricia Ferrer

Full Text Available Iron chelators for the treatment of malaria have proven therapeutic activity in vitro and in vivo in both humans and mice, but their clinical use is limited by the unsuitable absorption and pharmacokinetic properties of the few available iron chelators. FBS0701, (S3"-(HO-desazadesferrithiocin-polyether [DADFT-PE], is an oral iron chelator currently in Phase 2 human studies for the treatment of transfusional iron overload. The drug has very favorable absorption and pharmacokinetic properties allowing for once-daily use to deplete circulating free iron with human plasma concentrations in the high µM range. Here we show that FBS0701 has inhibition concentration 50% (IC(50 of 6 µM for Plasmodium falciparum in contrast to the IC(50 for deferiprone and deferoxamine at 15 and 30 µM respectively. In combination, FBS0701 interfered with artemisinin parasite inhibition and was additive with chloroquine or quinine parasite inhibition. FBS0701 killed early stage P. falciparum gametocytes. In the P. berghei Thompson suppression test, a single dose of 100 mg/kg reduced day three parasitemia and prolonged survival, but did not cure mice. Treatment with a single oral dose of 100 mg/kg one day after infection with 10 million lethal P. yoelii 17XL cured all the mice. Pretreatment of mice with a single oral dose of FBS0701 seven days or one day before resulted in the cure of some mice. Plasma exposures and other pharmacokinetics parameters in mice of the 100 mg/kg dose are similar to a 3 mg/kg dose in humans. In conclusion, FBS0701 demonstrates a single oral dose cure of the lethal P. yoelii model. Significantly, this effect persists after the chelator has cleared from plasma. FBS0701 was demonstrated to remove labile iron from erythrocytes as well as enter erythrocytes to chelate iron. FBS0701 may find clinically utility as monotherapy, a malarial prophylactic or, more likely, in combination with other antimalarials.

Investigation of polymer composite for high dose dosimetry

Energy Technology Data Exchange (ETDEWEB)

Pereira, E.L.M.; Batista, A.S.M., E-mail: adriananuclear@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Ribeiro, F.A.S.; Santos, A.P.; Faria, L.O.; Oliveira, A.H. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Introduction: This paper presents the efficacy evaluation of PVDF and nanocomposites of the PVDF films for high gamma dosimetry. Our scope in this first part of our studies is the selection of the most promising film for future dosimetry trials, where the proportionality of response of the selected material will be investigated over a large range of doses and dose rates. Methods: Was prepared nanocomposites made by mixing Poly(vinylidene fluoride) (PVDF), zirconium oxide (ZrO{sub 2}) and multi-walled carbon nanotubes (MWCNTs) aiming to find dosimetric properties for applications in high dose dosimetry. The samples were irradiated with a Co-60 source at constant dose rate (16.7 kGy/h), with doses ranging from 100 to 2750 kGy. The UV-Vis and FTIR spectrophotometry have been used to monitor the appearing of C=C conjugated bonds and radio-oxidation of carbon (C=O). Results: FTIR spectrometry has that the absorbance intensities at 1715 cm{sup -1} and 1730 cm{sup -1} can be used for high dosimetry purposes for gamma doses ranging from 400 to 2750 kGy. In this range, it is possible to observe a linear relationship between Abs & Dose. Fading of signal was evaluated for one month and reproducibility in 2000 kGy dose. Conclusion: FTIR spectroscopic data revealed two optical absorption bands at 1715 cm{sup -1} and 1730 cm{sup -1} whose intensities are unambiguously related to gamma delivered dose ranging from 400 kGy to 2750 kGy. (author)

Methodology of high dose research in medical radiodiagnostic

International Nuclear Information System (INIS)

Barboza, Adriana E.; Martins, Cintia P. de S.

2013-01-01

This work has as main purpose to study occupational exposure in diagnostic radiology in medical cases of high doses recorded in 2011 at the national level . These doses were recorded by monitoring individual of the occupationally exposed individuals (OEI's). This monitoring of the doses received by ionizing radiation has as main objective to ensure that the principle of dose limitation is respected. In this study it were evaluated doses of 372 OEI's radiology in different Brazilian states. Doses were extracted from the database of Sector Management Doses of the Institute for Radioprotection and Dosimetry - IRD/CNEN-RJ, Brazil. The information from the database provide reports of doses from several states, which allows to quantify statistically, showing those with the highest doses in four areas: dose greater than or equal to 20 mSv apron and chest and dose greater than or equal to 100 mSv apron and chest. The identification of these states allows the respective Sanitary Surveillance (VISA), be aware of the events and make plans to reduce them. This study clarified the required procedures when there is a record of high dose emphasizing the importance of using protective radiological equipment, dosimeter and provide a safety environment work by maintaining work equipment. Proposes the ongoing training of professionals, emphasizing the relevance of the concepts of radiation protection and the use of the questionnaire with their investigative systematic sequence, which will allow quickly and efficiently the success the investigations

High-dose preoperative radiation for cancer of the rectum: Impact of radiation dose on patterns of failure and survival

International Nuclear Information System (INIS)

Ahmad, N.R.; Mohiuddin, M.; Marks, G.

1993-01-01

A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications. Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers were given a higher dose, 55 Gy using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose. Fourteen percent of the total group developed a local recurrence; 20% in the low-dose group as compared with 6% in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups. High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. 27 refs., 2 figs., 8 tabs

Acute renal failure in high dose carboplatin chemotherapy

NARCIS (Netherlands)

Frenkel, J.; Kool, G.; de Kraker, J.

1995-01-01

Carboplatin has been reported to cause acute renal failure when administered in high doses to adult patients. We report a 4 1/2-year-old girl who was treated with high-dose carboplatin for metastatic parameningeal embryonal rhabdomyosarcoma. Acute renal failure developed followed by a slow partial

Dose intercomparison studies for standardization of high-dose dosimetry in Viet Nam

International Nuclear Information System (INIS)

Mai Hoang Hoa; Duong Nguyen Dinh; Kojima, T.

1999-01-01

The Irradiation Center of the Vietnam Atomic Energy Commission (IC-VAEC) is planning to establish a traceability system for high-dose dosimetry and to provide high-dose standards as a secondary standard dosimetry laboratory (SSDL) level in Vietnam. For countries which do not have a standard dosimetry laboratory, the participation in the International Dose Assurance Service (IDAS) operated by the International Atomic Energy Agency (IAEA) is the most common means to verify own dosimetry performance with a certain uncertainty. This is, however, only one-direction dose intercomparison with evaluation by IAEA including unknown parameter at participant laboratories. The SSDL level laboratory should have traceability as well as compatibility, ability to evaluate uncertainties of its own dosimetry performance by itself In the present paper, we reviewed our dosimetry performance through two-way dose intercomparison studies and self-evaluation of uncertainty in our dosimetry procedure. The performance of silver dichromate dosimeter as reference transfer dosimeter in IC-VAEC was studied through two-way blind dose intercomparison experiments between the IC-VAEC and JAERI. As another channel of dose intercomparison with IAEA, alanine dosimeters issued by IDAS were simultaneously irradiated with the IC-VAEC dichromate dosimeters at IC-VAEC and analyzed by IAEA. Dose intercomparison between IC-VAEC and JAERI results into a good agreement (better than ±2.5%), and IDAS results also show similar agreement within ±3.0%. The uncertainty was self-estimated on the basis of the JAERI alanine dosimetry, and a preliminary value of about 1.86% at a 68% confidence level is established. The results from these intercomparisons and our estimation of the uncertainty are consistent. We hope that our experience is valuable to other countries which do not have dosimetry standard laboratories and/or are planning to establish them. (author)

Evaluation of Sphingolipids in Wistar Rats Treated to Prolonged and Single Oral Doses of Fumonisin B1

Science.gov (United States)

Direito, Glória M.; Almeida, Adriana P.; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

2009-01-01

The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B1 (FB1). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB1. Prolonged exposure to FB1 caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB1. Animals receiving a single dose of FB1 presented variations in Sa and So levels and in the Sa/So ratio. PMID:19333435

A simulation study on the dose distribution for a single beam of the gamma knife

International Nuclear Information System (INIS)

Chen, Chin-cheng; Jiang, Shiang-Huei; Lee, Chung-chi; Shiau, Cheng-Ying

2000-01-01

The purpose of this study is to evaluate the impact of the tissue heterogeneity on the dose distribution for a single beam of the gamma knife. The EGS4 Monte Carlo code was used to simulate both depth and radial profiles of the radiation dose in homogeneous and heterogeneous phantoms, respectively. The results are compared with the dose distribution calculated using the mathematical model of Gamma Plan, the treatment planning system of the gamma knife. The skull and sinus heterogeneity were simulated by a Teflon shell and an air shell, respectively. It was found that the tissue heterogeneity caused significant perturbation on the absolute depth dose at the focus as well as on the depth-dose distribution near the phantom surface and/or at the interface but little effect on the radial dose distribution. The effect of the beam aperture on the depth-dose distribution was also investigated in this study. (author)

An explanation for the multiplicative and the additive dose-effect relationship with the single-hit model

International Nuclear Information System (INIS)

Kottbauer, M.M.; Fleck, C.M.; Schoellnberger, H.

1997-01-01

For solid tumors and for leukemia the excess cancer rate after a single radiation dose D is different. The multiplicative model describes the excess solid tumor probability rate which is proportional to the background rate of cancer and dependent on dose D. The additive model describes the excess probability rate for leukaemia which is proportional to the dose D but unrelated to the spontaneous rate of cancer. A second great difference between the two models is the duration of the increased cancer probability rate. The multiplicative mode predicts that the additional cancer risk persist the whole lifetime after exposure and the additive model predicts excess risk over a period of time. With the Single-hit model (SHM) which is a multistage cancer model both dose-response relationships can be described. It will be shown that only small differences in the derivation will lead to the different relationships. We then analyze the incidence data of leukemia (1950-1987) and of all solid tumors (1958-1987) of the atomic bomb survivors. (author)

Evidence for single-dose protection by the bivalent HPV vaccine-Review of the Costa Rica HPV vaccine trial and future research studies.

Science.gov (United States)

Kreimer, Aimée R; Herrero, Rolando; Sampson, Joshua N; Porras, Carolina; Lowy, Douglas R; Schiller, John T; Schiffman, Mark; Rodriguez, Ana Cecilia; Chanock, Stephen; Jimenez, Silvia; Schussler, John; Gail, Mitchell H; Safaeian, Mahboobeh; Kemp, Troy J; Cortes, Bernal; Pinto, Ligia A; Hildesheim, Allan; Gonzalez, Paula

2018-01-20

The Costa Rica Vaccine Trial (CVT), a phase III randomized clinical trial, provided the initial data that one dose of the HPV vaccine could provide durable protection against HPV infection. Although the study design was to administer all participants three doses of HPV or control vaccine, 20% of women did not receive the three-dose regimens, mostly due to involuntary reasons unrelated to vaccination. In 2011, we reported that a single dose of the bivalent HPV vaccine could be as efficacious as three doses of the vaccine using the endpoint of persistent HPV infection accumulated over the first four years of the trial; findings independently confirmed in the GSK-sponsored PATRICIA trial. Antibody levels after one dose, although lower than levels elicited by three doses, were 9-times higher than levels elicited by natural infection. Importantly, levels remained essentially constant over at least seven years, suggesting that the observed protection provided by a single dose might be durable. Much work has been done to assure these non-randomized findings are valid. Yet, the group of recipients who received one dose of the bivalent HPV vaccine in the CVT and PATRICIA trials was small and not randomly selected nor blinded to the number of doses received. The next phase of research is to conduct a formal randomized, controlled trial to evaluate the protection afforded by a single dose of HPV vaccine. Complementary studies are in progress to bridge our findings to other populations, and to further document the long-term durability of antibody response following a single dose. Published by Elsevier Ltd.

High-dose contrast-enhanced MRI in multiple sclerosis

International Nuclear Information System (INIS)

Koudriavtseva, T.; Pozzilli, C.; Di Biasi, C.; Iannilli, M.; Trasimeni, G.; Gasperini, C.; Argentino, C.; Gualdi, G.F.

1996-01-01

Contrast-enhanced MRI is effective for assessing disease activity in multiple sclerosis (MS) and may provide an outcome measure for testing the efficacy of treatment in clinical trials. To compare the sensitivity of high-dose gadolinium-HP-DO3A with that of a standard dose of gadolinium-DTPA, we studied 16 patients with relapsing-remitting MS in the acute phase of the disease. Each underwent two MRI examinations within at most 48 h. The initial MRI study was with a standard dose of gadolinium-DTPA (0.1 mmol/kg), and the second one an experimental dose of gadolinium-HP-DO3A (0.3 mmol/kg). No adverse effects were attributed to the contrast media. The high-dose study revealed more enhancing lesions than the standard-dose study (56 vs 38). This difference was found to be more relevant for infratentorial and small lesions. Furthermore, with the higher dose, there was a marked qualitative improvement in the visibility and delineation of the lesions. (orig.). With 4 figs., 2 tabs

High-dose contrast-enhanced MRI in multiple sclerosis

Energy Technology Data Exchange (ETDEWEB)

Koudriavtseva, T. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Pozzilli, C. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Di Biasi, C. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy); Iannilli, M. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy); Trasimeni, G. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy); Gasperini, C. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Argentino, C. [Department of Neurosciences, University of Rome ``La Sapienza`` Rome (Italy); Gualdi, G.F. [MR Unit, Clinica Medica 1, University of Rome ``La Sapienza``, Rome (Italy)

1996-05-01

Contrast-enhanced MRI is effective for assessing disease activity in multiple sclerosis (MS) and may provide an outcome measure for testing the efficacy of treatment in clinical trials. To compare the sensitivity of high-dose gadolinium-HP-DO3A with that of a standard dose of gadolinium-DTPA, we studied 16 patients with relapsing-remitting MS in the acute phase of the disease. Each underwent two MRI examinations within at most 48 h. The initial MRI study was with a standard dose of gadolinium-DTPA (0.1 mmol/kg), and the second one an experimental dose of gadolinium-HP-DO3A (0.3 mmol/kg). No adverse effects were attributed to the contrast media. The high-dose study revealed more enhancing lesions than the standard-dose study (56 vs 38). This difference was found to be more relevant for infratentorial and small lesions. Furthermore, with the higher dose, there was a marked qualitative improvement in the visibility and delineation of the lesions. (orig.). With 4 figs., 2 tabs.

The Influence of Dosing Modes of Coagulate on Arsenic Removal

Directory of Open Access Journals (Sweden)

Zhibin Zhang

2014-01-01

Full Text Available Three different dosing modes, including one single dosing mode and two sequential dosing modes, were applied in high-arsenic contaminated water treatment. The results illustrated that the As (V soluble and the As (V nonspecifically sorbed were the insignificant species from Fe-As (V samples in the sequential dosing mode, while they were higher in the single dosing mode. However, it could be further concluded that the mobility of the Fe-As (V in sequential dosing mode was greater than that in single dosing mode. Besides, the main arsenic speciation governing the arsenic-borne coagulates was the As (V associated with poorly crystalline hydrous oxides of Fe in sequential or single dosing mode. Moreover, the particle size distribution analysis indicated that the sequential dosing mode was more prevalent in neutralizing and adsorbing the As (V compared with the single dosing mode. In the FT-IR spectra, the presence of arsenic was highlighted by a well resolved band at 825–829 cm−1. The positions of the As–O stretching vibration bands were shifted gradually as the dosing mode changed from the single to the sequential. This result could be related to the distribution of arsenic speciation in different dosing modes.

Standardization of high-dose measurement of electron and gamma ray absorbed doses and dose rates

International Nuclear Information System (INIS)

McLaughlin, W.L.

1985-01-01

Intense electron beams and gamma radiation fields are used for sterilizing medical devices, treating municipal wastes, processing industrial goods, controlling parasites and pathogens, and extending the shelf-life of foods. Quality control of such radiation processes depends largely on maintaining measurement quality assurance through sound dosimetry procedures in the research leading to each process, in the commissioning of that process, and in the routine dose monitoring practices. This affords documentation as to whether satisfactory dose uniformity is maintained throughout the product and throughout the process. Therefore, dosimetry at high doses and dose rates must in many radiation processes be standardized carefully, so that 'dosimetry release' of a product is verified. This standardization is initiated through preliminary dosimetry intercomparison studies such as those sponsored recently by the IAEA. This is followed by establishing periodic exercises in traceability to national or international standards of absorbed dose and dose rate. Traceability is achieved by careful selection of dosimetry methods and proven reference dosimeters capable of giving sufficiently accurate and precise 'transfer' dose assessments: (1) they must be calibrated or have well-established radiation-yield indices; (2) their radiation response characteristics must be reproducible and cover the dose range of interest; (3) they must withstand the rigours of back-and-forth mailing between a central standardizing laboratory and radiation processing facilities, without excessive errors arising due to instabilities, dosimeter batch non-uniformities, and environmental and handling stresses. (author)

Vaginal bleeding following the use of a single dose of 1.5mg ...

African Journals Online (AJOL)

Introduction: Recent studies have shown that a single dose of 1.5 mg levonorgestrel is an effective and safe emergency contraceptive but detailed information on its menstrual side effects is lacking. This study assessed the vaginal bleeding patterns in healthy women who used the medication for emergency contraception.

Quantitative assessment of changes in the dermal fibroblast population of pig skin after single doses of X-rays

Energy Technology Data Exchange (ETDEWEB)

Hamlet, R.; Hopewell, J.W.

1988-10-01

Changes in the density of fibroblast nuclei in reticular dermis of pigs was studied from 6 to 104 weeks after a single dose of 15.4 Gy of X-rays. The largest decrease in fibroblasts occurred between 12 and 26 weeks after irradiation; after this there was only a slight fall in fibroblast number until 104 weeks when observations ceased. At 26 weeks and later times after irradiation reduction in the density of fibroblast nuclei in the reticular dermis was dose-dependent for single doses in the range 8.0-20.7 Gy. The dose-response curve had an initial shoulder, after which the fall in the fibroblast nuclear density was linearly related to dose. Data obtained between 26 weeks and 104 weeks after irradiation, could be fitted by the same dose-response curve. The fall in the counts of fibroblast nuclei was compared with earlier studies. The loss of fibroblasts occurred after an initial reduction in blood flow in the pig skin but was concomitant with general reduction in dermal thickness.

Can a single dose of human papillomavirus (HPV) vaccine prevent cervical cancer? Early findings from an Indian study.

Science.gov (United States)

Sankaranarayanan, Rengaswamy; Joshi, Smita; Muwonge, Richard; Esmy, Pulikottil Okkuru; Basu, Partha; Prabhu, Priya; Bhatla, Neerja; Nene, Bhagwan M; Shaw, Janmesh; Poli, Usha Rani Reddy; Verma, Yogesh; Zomawia, Eric; Pimple, Sharmila; Tommasino, Massimo; Pawlita, Michael; Gheit, Tarik; Waterboer, Tim; Sehr, Peter; Pillai, Madhavan Radhakrishna

2018-03-15

Human papillomavirus (HPV) vaccination is a major strategy for preventing cervical and other ano-genital cancers. Worldwide HPV vaccination introduction and coverage will be facilitated if a single dose of vaccine is as effective as two or three doses or demonstrates significant protective effect compared to 'no vaccination'. In a multi-centre cluster randomized trial of two vs three doses of quadrivalent HPV vaccination (Gardasil™) in India, suspension of the vaccination due to events unrelated to the study led to per protocol and partial vaccination of unmarried 10-18 year old girls leading to four study groups, two by design and two by default. They were followed up for the primary outcomes of immunogenicity in terms of L1 genotype-specific binding antibody titres, neutralising antibody titres, and antibody avidity for the vaccine-targeted HPV types and HPV infections. Analysis was per actual number of vaccine doses received. This study is registered with ISRCTN, number ISRCTN98283094; and with ClinicalTrials.gov, number NCT00923702. Of the 17,729 vaccinated girls, 4348 (25%) received three doses on days 1, 60, 180 or later, 4979 (28%) received two doses on days 1 and 180 or later, 3452 (19%) received two doses on days 1 and 60, and 4950 (28%) received one dose. One dose recipients demonstrated a robust and sustained immune response against HPV 16 and 18, albeit inferior to that of 3- or 2-doses and the antibody levels were stable over a 4 year period. The frequencies of cumulative incident and persistent HPV 16 and 18 infections up to 7 years of follow-up were similar and uniformly low in all the vaccinated study groups; the frequency of HPV 16 and 18 infections were significantly higher in unvaccinated age-matched control women than among vaccine recipients. The frequency of vaccine non-targeted HPV types was similar in the vaccinated groups but higher in the unvaccinated control women. Our results indicate that a single dose of quadrivalent HPV

Update on pediatric resuscitation drugs: high dose, low dose, or no dose at all.

Science.gov (United States)

Sorrentino, Annalise

2005-04-01

Pediatric resuscitation has been a topic of discussion for years. It is difficult to keep abreast of changing recommendations, especially for busy pediatricians who do not regularly use these skills. This review will focus on the most recent guidelines for resuscitation drugs. Three specific questions will be discussed: standard dose versus high-dose epinephrine, amiodarone use, and the future of vasopressin in pediatric resuscitation. The issue of using high-dose epinephrine for cardiopulmonary resuscitation refractory to standard dose epinephrine has been a topic of debate for many years. Recently, a prospective, double-blinded study was performed to help settle the debate. These results will be reviewed and compared with previous studies. Amiodarone is a medication that was added to the pediatric resuscitation algorithms with the most recent recommendations from the American Heart Association in 2000. Its use and safety will also be discussed. Another topic that is resurfacing in resuscitation is the use of vasopressin. Its mechanism and comparisons to other agents will be highlighted, although its use in the pediatric patient has not been thoroughly studied. Pediatric resuscitation is a constantly evolving subject that is on the mind of anyone taking care of sick children. Clinicians are continually searching for the most effective methods to resuscitate children in terms of short- and long-term outcomes. It is important to be familiar with not only the agents being used but also the optimal way to use them.

Dosimetric perturbations of a lead shield for surface and interstitial high-dose-rate brachytherapy

International Nuclear Information System (INIS)

Candela-Juan, Cristian; Granero, Domingo; Vijande, Javier; Ballester, Facundo; Perez-Calatayud, Jose; Rivard, Mark J

2014-01-01

In surface and interstitial high-dose-rate brachytherapy with either 60 Co, 192 Ir, or 169 Yb sources, some radiosensitive organs near the surface may be exposed to high absorbed doses. This may be reduced by covering the implants with a lead shield on the body surface, which results in dosimetric perturbations. Monte Carlo simulations in Geant4 were performed for the three radionuclides placed at a single dwell position. Four different shield thicknesses (0, 3, 6, and 10 mm) and three different source depths (0, 5, and 10 mm) in water were considered, with the lead shield placed at the phantom surface. Backscatter dose enhancement and transmission data were obtained for the lead shields. Results were corrected to account for a realistic clinical case with multiple dwell positions. The range of the high backscatter dose enhancement in water is 3 mm for 60 Co and 1 mm for both 192 Ir and 169 Yb. Transmission data for 60 Co and 192 Ir are smaller than those reported by Papagiannis et al (2008 Med. Phys. 35 4898–4906) for brachytherapy facility shielding; for 169 Yb, the difference is negligible. In conclusion, the backscatter overdose produced by the lead shield can be avoided by just adding a few millimetres of bolus. Transmission data provided in this work as a function of lead thickness can be used to estimate healthy organ equivalent dose saving. Use of a lead shield is justified. (paper)

Comparison of scatter doses from a multislice and a single slice CT scanner

International Nuclear Information System (INIS)

Burrage, J. W.; Causer, D. A.

2006-01-01

During shielding calculations for a new multislice CT (MSCT) scanner it was found that the manufacturer's data indicated significantly higher external scatter doses than would be generated for a single slice CT (SSCT). Even allowing for increased beam width, the manufacturer's data indicated that the scatter dose per scan was higher by a factor of about 3 to 4. The magnitude of the discrepancy was contrary to expectations and also contrary to a statement by the UK ImPACT group, which indicated that when beam width is taken into account, the scatter doses should be similar. The matter was investigated by comparing scatter doses from an SSCT and an MSCT. Scatter measurements were performed at three points using a standard perspex CTDI phantom, and CT dose indices were also measured to compare scanner output. MSCT measurements were performed with a 40 mm wide beam, SSCT measurements with a 10 mm wide beam. A film badge survey was also performed after the installation of the MSCT scanner to assess the adequacy of lead shielding in the room. It was found that the scatter doses from the MSCT were lower than indicated by the manufacturer's data. MSCT scatter doses were approximately 4 times higher than those from the SSCT, consistent with expectations due to beam width differences. The CT dose indices were similar, and the film badge survey indicated that the existing shielding, which had been adequate for the SSCT, was also adequate for the MSCT

Image quality and absorbed dose comparison of single- and dual-source cone-beam computed tomography.

Science.gov (United States)

Miura, Hideharu; Ozawa, Shuichi; Okazue, Toshiya; Kawakubo, Atsushi; Yamada, Kiyoshi; Nagata, Yasushi

2018-04-17

Dual-source cone-beam computed tomography (DCBCT) is currently available in the Vero4DRT image-guided radiotherapy system. We evaluated the image quality and absorbed dose for DCBCT and compared the values with those for single-source CBCT (SCBCT). Image uniformity, Hounsfield unit (HU) linearity, image contrast, and spatial resolution were evaluated using a Catphan phantom. The rotation angle for acquiring SCBCT and DCBCT images is 215° and 115°, respectively. The image uniformity was calculated using measurements obtained at the center and four peripheral positions. The HUs of seven materials inserted into the phantom were measured to evaluate HU linearity and image contrast. The Catphan phantom was scanned with a conventional CT scanner to measure the reference HU for each material. The spatial resolution was calculated using high-resolution pattern modules. Image quality was analyzed using ImageJ software ver. 1.49. The absorbed dose was measured using a 0.6-cm 3 ionization chamber with a 16-cm-diameter cylindrical phantom, at the center and four peripheral positions of the phantom, and calculated using weighted cone-beam CT dose index (CBCTDI w ). Compared with that of SCBCT, the image uniformity of DCBCT was slightly reduced. A strong linear correlation existed between the measured HU for DCBCT and the reference HU, although the linear regression slope was different from that of the reference HU. DCBCT had poorer image contrast than did SCBCT, particularly with a high-contrast material. There was no significant difference between the spatial resolutions of SCBCT and DCBCT. The absorbed dose for DCBCT was higher than that for SCBCT, because in DCBCT, the two x-ray projections overlap between 45° and 70°. We found that the image quality was poorer and the absorbed dose was higher for DCBCT than for SCBCT in the Vero4DRT. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of

Attention benefits after a single dose of metadoxine extended release in adults with predominantly inattentive ADHD.

Science.gov (United States)

Manor, Iris; Rubin, Jonathan; Daniely, Yaron; Adler, Lenard A

2014-09-01

To assess the first-dose effectiveness and tolerability of metadoxine extended release (MDX) in adults with predominantly inattentive attention-deficit/hyperactivity disorder (ADHD-PI). In this double-blind, placebo-controlled, crossover study, adults with ADHD-PI were randomized 1:1:1 to receive a single dose of MDX 1400 mg, MDX 700 mg, and placebo (ClinicalTrials.gov identifier: NCT01685281). The primary efficacy end point was the mean change in the Test of Variables of Attention (TOVA) ADHD score from baseline to 3 to 5 hours after drug administration. Secondary assessments included TOVA subscores, TOVA response rates (defined as an increase of 0.8 points in the TOVA ADHD score), and the Cambridge Neuropsychological Automated Test Battery. Safety assessments included adverse events and vital signs. The intention-to-treat population included 36 patients (52.8% men; mean age, 32 years). The efficacy of MDX 1400 mg was demonstrated by a statistically significant difference in the mean (± SD) change in the TOVA ADHD score at baseline to 3 to 5 hours after drug administration compared with placebo (2.0 [4.2]; P = 0.009). The TOVA response time variability subscore was significantly different between MDX 1400 mg and placebo (mean difference, 7.9 [19.2] points; P = 0.022). Significantly more adults responded to single-dose MDX 1400 mg versus placebo (97.1% vs 71.4%, P = 0.006). There were no statistically significant differences between MDX 700 mg and placebo on any measures. Exploratory analyses of the Cambridge Neuropsychological Automated Test Battery did not yield significant findings. Fatigue and headache were the 2 most frequently reported adverse events. There were no clinically significant abnormalities in laboratory values, vital signs measurements, Columbia-Suicide Severity Rating Scale scores, or electrocardiographic parameters. Single-dose MDX 1400 mg significantly improved sustained and selective attention in adults with ADHD-PI as measured by the TOVA

Retrospective analysis of dose delivery in intra-operative high dose rate brachytherapy

International Nuclear Information System (INIS)

Oh, M.; Avadhani, J.S.; Malhotra, H.K.; Cunningham, B.; Tripp, P.; Jaggernauth, W.; Podgorsak, M.B.

2007-01-01

Background. This study was performed to quantify the inaccuracy in clinical dose delivery due to the incomplete scatter conditions inherent in intra-operative high dose rate (IOHDR) brachytherapy. Methods. Treatment plans of 10 patients previously treated in our facility, which had irregular shapes of treated areas, were used. Treatment geometries reflecting each clinical case were simulated using a phantom assembly with no added build-up on top of the applicator. The treatment planning geometry (full scatter surrounding the applicator) was subsequently simulated for each case by adding bolus on top of the applicator. Results. For geometries representing the clinical IOHDR incomplete scatter environment, measured doses at the 5 mm and 10 mm prescription depths were lower than the corresponding prescribed doses by about 7.7% and 11.1%, respectively. Also, for the two prescription methods, an analysis of the measured dose distributions and their corresponding treatment plans showed average decreases of 1.2 mm and 2.2 mm in depth of prescription dose, respectively. Conclusions. Dosimetric calculations with the assumption of an infinite scatter environment around the applicator and target volume have shown to result in dose delivery errors that significantly decrease the prescription depth for IOHDR treatment.(author)

Single Intramuscular-dose Toxicity of Water soluble Carthmi-Flos herbal acupuncture (WCF in Sprague-Dawley Rats

Directory of Open Access Journals (Sweden)

Lee Hyung-geol

2014-03-01

Full Text Available Objectives: This experiment was conducted to examine the toxicity of WCF (Water soluble Carthmi-Flos herbal acupuncture by administering a single intramuscular dose of WCF in 6-week-old, male and female Sprague-Dawley rats and to find the lethality dose for WCF. Methods: The experiment was conducted at Biotoxtech according to Good Laboratory Practices under a request by the Korean Pharmacopuncture Institute. This experiment was performed based on the testing standards of “Toxicity Test Standards for Drugs” by the Ministry of Food and Drug Safety. Subjects were divided into 4 groups: 1 control group in which normal saline was administered and 3 test groups in which 0.1, 0.5 or 1.0 mL of WCF was administered; a single intramuscular dose was injected into 5 males and 5 females in each group. General symptoms and body weights were observed/measured for 14 days after injection. At the end of the observation period, hematological and clinical chemistry tests were performed, followed by necropsy and histopathological examinations of the injected sections. Results: No mortalities were observed in any group. Also, symptoms, body weight, hematology, clinical chemistry and necropsy were not affected. However, histopathological examination of the injected part in one female in the 1.0-mL group showed infiltration of mononuclear cells and a multi-nucleated giant cell around eosinophilic material. Conclusion: Administration of single intramuscular doses of WCF in 3 groups of rats showed that the approximate lethal dose of WCF for all rats was in excess of 1.0 mL, as no mortalities were observed for injections up to and including 1.0 mL.

Dose rate and dose fractionation studies in total body irradiation of dogs

International Nuclear Information System (INIS)

Kolb, H.J.; Netzel, B.; Schaffer, E.; Kolb, H.

1979-01-01

Total body irradiation (TBI) with 800-900 rads and allogeneic bone marrow transplantation according to the regimen designated by the Seattle group has induced remissions in patients with otherwise refractory acute leukemias. Relapse of leukemia after bone marrow transplantation remains the major problem, when the Seattle set up of two opposing 60 Co-sources and a low dose rate is used in TBI. Studies in dogs with TBI at various dose rates confirmed observations in mice that gastrointestinal toxicity is unlike toxicity against hemopoietic stem cells and possibly also leukemic stem cells depending on the dose rate. However, following very high single doses (2400 R) and marrow infusion acute gastrointestinal toxicity was not prevented by the lowest dose rate studied (0.5 R/min). Fractionated TBI with fractions of 600 R in addition to 1200 R (1000 rads) permitted the application of total doses up to 300 R followed by marrow infusion without irreversible toxicity. 26 dogs given 2400-3000 R have been observed for presently up to 2 years with regard to delayed radiation toxicity. This toxicity was mild in dogs given single doses at a low dose rate or fractionated TBI. Fractionated TBI is presently evaluated with allogeneic transplants in the dog before being applied to leukemic patients

Fertility of Tall Girls Treated with High-Dose Estrogen, a Dose-Response Relationship

NARCIS (Netherlands)

Hendriks, A. E. J.; Drop, S. L. S.; Laven, J. S. E.; Boot, A. M.

Context: High-dose estrogen treatment to reduce final height of tall girls increases their risk for infertility in later life. Objective: The aim was to study the effect of estrogen dose on fertility outcome of these women. Design/Setting: We conducted a retrospective cohort study of university

Successful Treatment of Rubral Tremor by High-Dose Trihexyphenidyl: A Case Report

Directory of Open Access Journals (Sweden)

Li-Min Liou

2006-03-01

Full Text Available A 24-year-old male suffered from acute-onset right-sided hemiparesis, dysarthria, and ophthalmoplegia in February 2001. Brain magnetic resonance imaging revealed a cavernous angioma with hemorrhage over the left thalamus. Moreover, some rhythmic, coarse, low-frequency (2-3 Hz oscillation over the right wrist and elbow was noted 1 month later. Action tremor was more predominant than resting tremor. Rubral tremor was diagnosed on the basis of the clinical presentation and tremography analysis. Rubral tremor is not unusual, and pharmacotherapy is nearly always ineffective in clinical practice. Deep brain stimulation, thalamotomy, and pallidotomy are all considered effective according to recent research. However, they are either very expensive or invasive, and involve surgical risks. In our patient, we tried valproate, clonazepam, and verapamil one after another, but all in vain. Finally, titration of trihexyphenidyl provided significant benefit. The tremor was successfully controlled by a single high daily dose of trihexyphenidyl (38 mg without severe or uncomfortable side effects. Here, we report a case of successful monotherapy of rubral tremor with high-dose trihexyphenidyl.

Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

Energy Technology Data Exchange (ETDEWEB)

Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K

2000-07-01

A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (autho000.

Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

International Nuclear Information System (INIS)

Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K.

2000-01-01

A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (author)

Single dose oral ibuprofen plus paracetamol (acetaminophen) for acute postoperative pain.

Science.gov (United States)

Derry, Christopher J; Derry, Sheena; Moore, R Andrew

2013-06-24

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. Some combinations of ibuprofen and paracetamol are available for use without prescription in some acute pain situations. To assess the efficacy and adverse effects of single dose oral ibuprofen plus paracetamol for acute postoperative pain using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 4 of 12, 2013), MEDLINE (1950 to May 21st 2013), EMBASE (1974 to May 21st 2013), the Oxford Pain Database, ClinicalTrials.gov, and reference lists of articles. Randomised, double-blind clinical trials of single dose, oral ibuprofen plus paracetamol compared with placebo or the same dose of ibuprofen alone for acute postoperative pain in adults. Two review authors independently considered trials for inclusion in the review, assessed quality, and extracted data. We used validated equations to calculate the area under the pain relief versus time curve and derive the proportion of participants with at least 50% of maximum pain relief over six hours. We calculated relative risk (RR) and number needed to treat to benefit (NNT) for ibuprofen plus paracetamol, ibuprofen alone, or placebo. We used information on use of rescue medication to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. We also collected information on adverse events. Searches identified three studies involving 1647 participants. Each of them examined several dose combinations. Included studies provided data from 508 participants for the comparison of ibuprofen 200 mg + paracetamol 500 mg with placebo, 543

Single-dose Toxicity of ShinYangHur Herbal Acupuncture

Directory of Open Access Journals (Sweden)

Eunhye Cha

2015-06-01

Full Text Available Objectives: This study was carried out to analyze the single-dose toxicity of ShinYangHur (SYH herbal acupuncture injected into the muscles of Sprague-Dawley (SD rats. Methods: The SYH herbal acupuncture was made in a clean room at the Korean Pharmacopuncture Institute (KPI, Korea-Good Manufacturing Practice, K-GMP. After the mixing process with sterile distilled water, the pH was controlled to between 7.0 and 7.5. Then, NaCl was added to make a 0.9% isotonic solution by using sterilized equipment. All experiments were conducted at Biotoxtech, an institution authorized to perform non clinical studies under the regulations of Good Laboratory Practice (GLP. SD rats were chosen for the pilot study. Doses of SYH herbal acupuncture, 0.25, 0.5, and 1.0 mL, were administered to the experimental groups, and a dose of normal saline solution, 1.0 mL, was administered to the control group. This study was conducted under the approval of the Institutional Animal Ethics Committee. Results: No deaths or abnormalities occurred in any of the four groups. No significant changes in weight, hematological parameters or clinical chemistry between the control group and the experimental groups were observed. To check for abnormalities in organs and tissues, we used microscopy was used to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs or tissues. Conclusion: The above outcomes suggest that treatment with SYH herbal acupuncture is relatively safe. Further studies on this subject are needed to yield more concrete evidence.

Implementation of microsource high dose rate (mHDR) brachytherapy in developing countries

International Nuclear Information System (INIS)

2001-11-01

Brachytherapy using remote afterloading of a single high dose rate 192 Ir microsource was developed in the 1970s. After its introduction to clinics, this system has spread rapidly among developed Member States and has become a highly desirable modality in cancer treatment. This technique is now gradually being introduced to the developing Member States. The 192 Ir sources are produced with a high specific activity. This results in a high dose rate (HDR) to the tumour and shorter treatment times. The high specific activity simultaneously results in a much smaller source (so-called micro source, around I mm in diameter) which may be easily inserted into tissue through a thin delivery tube, the so-called interstitial treatment, as well as easily inserted into body cavities, the so-called intracavitary or endoluminal treatment. Another advantage is the ability to change dwell time (the time a source remains in one position) of the stepping source which allows dose distribution to match the target volume more closely. The purpose of this TECDOC is to advise radiation oncologists, medical physicists and hospital administrators in hospitals which are planning to introduce 192 Ir microsource HDR (mHDR) remote afterloading systems. The document supplements IAEA-TECDOC-1040, Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects, and will facilitate implementation of this new brachytherapy technology, especially in developing countries. The operation of the system, 'how to use the system', is not within the scope of this document. This TECDOC is based on the recommendations of an Advisory Group meeting held in Vienna in April 1999

Evaluation of preclinical single and multiple dose toxicity and efficacy of 213 Bi-labeled plasminogen activator inhibitor 2 for breast and prostate cancer

International Nuclear Information System (INIS)

Rizvi, S.; Li, Y.; Allen, B.; Littlejohn, T.; Ranson, M.; Links, M.; Irving, D.; Andrews, J.

2003-01-01

The aim of the study was to evaluate the single and multiple dose toxicity (maximum tolerated dose or MTD) regimes for 213 Bi-labeled PAI2. Dose range of 2-8 mCi/kg was used for the single dose toxicity studies. It was found that end point (20% weight loss and/or distressed behaviour) was not reached for the highest dose either with single or multiple dose injections. For multiple dose toxicity studies, the dose levels ranged between 0.4 - 2 mCi/kg, and were administered daily for 5 days. The highest level tested (2mCi/kg/day x 5) was the maximum tolerated dose as 3/6 mice succumbed to the endpoints. However, histological examination of major organs showed no adverse morphological changes. From these toxicity studies, we concluded that either a dose of 1.6mCi/kg of 213 Bi-PAI2 per day for 5 days or a single injection of 8 mCi/kg can be administered without reaching the endpoints. These dose levels were used for efficacy trials. The efficacy studies were conducted to examine if the 1.6mCi/kgday x 5 multiple dose schedule (sub-maximum tolerated dose) showed efficacy against established and early stage human breast and prostate tumours in mice. Statistical analyses of the data indicate a significant tumour growth rate delay and increased time to reach tumour size endpoint for alpha-PAI2 treatment compared to control tumours, in both pre-tumour stage and established tumour models

A luminescence imaging system for the routine measurement of single-grain OSL dose distributions

DEFF Research Database (Denmark)

Kook, Myung Ho; Lapp, Torben; Murray, Andrew

2015-01-01

the potential of an electron multiplying charge-coupled device (EMCCD), providing extremely low level light detection. We characterize the performance of the device by discussing reproducibility and evaluating uncertainties in OSL signals. Finally we derive a typical single grain natural dose distribution...

Radiation effects of high and low doses

International Nuclear Information System (INIS)

El-Naggar, A.M.

1998-01-01

The extensive proliferation of the uses and applications of atomic and nuclear energy resulted in possible repercussions on human health. The prominent features of the health hazards that may be incurred after exposure to high and low radiation doses are discussed. The physical and biological factors involved in the sequential development of radiation health effects and the different cellular responses to radiation injury are considered. The main criteria and features of radiation effects of high and low doses are comprehensively outlined

Long term results of a prospective dose escalation phase-II trial: Interstitial pulsed-dose-rate brachytherapy as boost for intermediate- and high-risk prostate cancer

International Nuclear Information System (INIS)

Lettmaier, Sebastian; Lotter, Michael; Kreppner, Stephan; Strnad, Annedore; Fietkau, Rainer; Strnad, Vratislav

2012-01-01

Purpose: We reviewed our seven year single institution experience with pulsed dose rate brachytherapy dose escalation study in patients with intermediate and high risk prostate cancer. Materials and methods: We treated a total of 130 patients for intermediate and high risk prostate cancer at our institution between 2000 and 2007 using PDR-brachytherapy as a boost after conformal external beam radiation therapy to 50.4 Gy. The majority of patients had T2 disease (T1c 6%, T2 75%, T3 19%). Seventy three patients had intermediate-risk and 53 patients had high-risk disease according to the D’Amico classification. The dose of the brachytherapy boost was escalated from 25 to 35 Gy – 33 pts. received 25 Gy (total dose 75 Gy), 63 pts. 30 Gy (total dose 80 Gy) and 34 pts. 35 Gy, (total dose 85 Gy) given in one session (dose per pulse was 0.60 Gy or 0.70 Gy/h, 24 h per day, night and day, with a time interval of 1 h between two pulses). PSA-recurrence-free survival according to Kaplan–Meier using the Phoenix definition of biochemical failure was calculated and also late toxicities according to Common Toxicity Criteria scale were assessed. Results: At the time of analysis with a median follow-up of 60 months biochemical control was achieved by 88% of patients – only 16/130 patients (12.3%) developed a biochemical relapse. Biochemical relapse free survival calculated according to Kaplan–Meier for all patients at 5 years was 85.6% (83.9% for intermediate-risk patients and 84.2% for high-risk patients) and at 9 years’ follow up it was 79.0%. Analysing biochemical relapse free survival separately for different boost dose levels, at 5 years it was 97% for the 35 Gy boost dose and 82% for the 25 and 30 Gy dose levels. The side effects of therapy were negligible: There were 18 cases (15%) of grade 1/2 rectal proctitis, one case (0.8%) of grade 3 proctitis, 18 cases (15%) of grade 1/2 cystitis, and no cases (0%) with dysuria grade 3. No patient had a bulbourethral

Remifentanil dose for laryngeal mask airway insertion with a single standard dose of propofol during emergency airway management in elderly patients.

Science.gov (United States)

Ryu, Junghee; Oh, Ah Young; Baek, Ji-Seok; Kim, Jin-Hee; Park, Sang-Heon; Noh, Jae-Mun

2014-04-01

This study determined the dose of remifentanil to use during insertion of a Classic™ laryngeal mask airway (LMA, The Laryngeal Mask Co., Nicosia, Cyprus) in elderly patients during emergency airway management when combined with a single dose of propofol. Patients aged 65-80 years were enrolled. Anesthesia was induced with propofol 1 mg/kg, and then a blinded dose of remifentanil was infused over 30 s after confirming the patient's loss of consciousness. The dose of remifentanil was determined using Dixon's up-and-down method, starting at 0.5 µg/kg (a step size of 0.1 µg/kg). Insertion of the LMA was attempted 60 s after loss of consciousness. In total, 23 patients were recruited and the mean age ± standard deviation was 72 ± 3 years. The effective dose for successful LMA insertion in 50% of the patients (ED50) was 0.20 ± 0.05 µg/kg. No patient needed more than 0.3 µg/kg. Remifentanil 0.20 ± 0.05 µg/kg with propofol 1 mg/kg resulted in excellent LMA insertion in 50% of elderly patients without significant hemodynamic changes during emergency airway management.

High daily doses of benzodiazepines among Quebec seniors: prevalence and correlates

Directory of Open Access Journals (Sweden)

Moride Yola

2001-11-01

Full Text Available Abstract Background Use of high daily doses of benzodiazepines is generally contraindicated for seniors. While both patient and physician factors may influence the use of high daily doses, previous research on the effect of patient factors has been extremely limited. The objectives of this study were to determine the one year prevalence of use of high daily doses of benzodiazepines, and examine physician and patient correlates of such use among Quebec community-dwelling seniors. Methods Patient information for 1423 community-dwelling Quebec seniors who participated in the Canadian Study of Health and Aging was linked to provincial health insurance administrative data bases containing detailed information on prescriptions received and prescribers. Results The standardized one year period prevalence of use of high daily doses of benzodiazepines was 7.9%. Use of high daily doses was more frequent among younger seniors and those who had reported anxiety during the previous year. Patients without cognitive impairment were more likely to receive high dose prescriptions from general practitioners, while those with cognitive impairment were more likely to receive high dose prescriptions from specialists. Conclusion High dose prescribing appears to be related to both patient and physician factors.

Spatial resolution of 2D ionization chamber arrays for IMRT dose verification: single-detector size and sampling step width

International Nuclear Information System (INIS)

Poppe, Bjoern; Djouguela, Armand; Blechschmidt, Arne; Willborn, Kay; Ruehmann, Antje; Harder, Dietrich

2007-01-01

The spatial resolution of 2D detector arrays equipped with ionization chambers or diodes, used for the dose verification of IMRT treatment plans, is limited by the size of the single detector and the centre-to-centre distance between the detectors. Optimization criteria with regard to these parameters have been developed by combining concepts of dosimetry and pattern analysis. The 2D-ARRAY Type 10024 (PTW-Freiburg, Germany), single-chamber cross section 5 x 5 mm 2 , centre-to-centre distance between chambers in each row and column 10 mm, served as an example. Additional frames of given dose distributions can be taken by shifting the whole array parallel or perpendicular to the MLC leaves by, e.g., 5 mm. The size of the single detector is characterized by its lateral response function, a trapezoid with 5 mm top width and 9 mm base width. Therefore, values measured with the 2D array are regarded as sample values from the convolution product of the accelerator generated dose distribution and this lateral response function. Consequently, the dose verification, e.g., by means of the gamma index, is performed by comparing the measured values of the 2D array with the values of the convolution product of the treatment planning system (TPS) calculated dose distribution and the single-detector lateral response function. Sufficiently small misalignments of the measured dose distributions in comparison with the calculated ones can be detected since the lateral response function is symmetric with respect to the centre of the chamber, and the change of dose gradients due to the convolution is sufficiently small. The sampling step width of the 2D array should provide a set of sample values representative of the sampled distribution, which is achieved if the highest spatial frequency contained in this function does not exceed the 'Nyquist frequency', one half of the sampling frequency. Since the convolution products of IMRT-typical dose distributions and the single

Single Dose of Consensus Hemagglutinin-Based Virus-Like Particles Vaccine Protects Chickens against Divergent H5 Subtype Influenza Viruses

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Peipei Wu

2017-11-01

Full Text Available The H5 subtype highly pathogenic avian influenza (HPAI virus is one of the greatest threats to global poultry industry. To develop broadly protective H5 subunit vaccine, a recombinant consensus HA sequence (rHA was constructed and expressed in virus-like particles (rHA VLPs in the baculovirus-insect cell system. The efficacy of the rHA VLPs vaccine with or without immunopotentiator (CVCVA5 was assessed in chickens. Compared to the commercial Re6 or Re6-CVCVA5 vaccines, single dose immunization of chickens with rHA VLPs or rHA-CVCVA5 vaccines induced higher levels of serum hemagglutinin inhibition titers and neutralization titers, mucosal antibodies, IFN-γ and IL-4 cytokines in sera, and cytotoxic T lymphocyte responses. The rHA VLPs vaccine was superior to the commercial Re6 vaccine in conferring cross-protection against different clades of H5 subtype viruses. This study reports that H5 subtype consensus HA VLP single dose vaccination provides broad protection against HPAI virus in chickens.

Proximity correction of high-dosed frame with PROXECCO

Science.gov (United States)

Eisenmann, Hans; Waas, Thomas; Hartmann, Hans

1994-05-01

Usefulness of electron beam lithography is strongly related to the efficiency and quality of methods used for proximity correction. This paper addresses the above issue by proposing an extension to the new proximity correction program PROXECCO. The combination of a framing step with PROXECCO produces a pattern with a very high edge accuracy and still allows usage of the fast correction procedure. Making a frame with a higher dose imitates a fine resolution correction where the coarse part is disregarded. So after handling the high resolution effect by means of framing, an additional coarse correction is still needed. Higher doses have a higher contribution to the proximity effect. This additional proximity effect is taken into account with the help of the multi-dose input of PROXECCO. The dose of the frame is variable, depending on the deposited energy coming from backscattering of the proximity. Simulation proves the very high edge accuracy of the applied method.

Single-dose and steady-state pharmacokinetics of tenofovir disoproxil fumarate in human immunodeficiency virus-infected children.

Science.gov (United States)

Hazra, Rohan; Balis, Frank M; Tullio, Antonella N; DeCarlo, Ellen; Worrell, Carol J; Steinberg, Seth M; Flaherty, John F; Yale, Kitty; Poblenz, Marianne; Kearney, Brian P; Zhong, Lijie; Coakley, Dion F; Blanche, Stephane; Bresson, Jean Louis; Zuckerman, Judith A; Zeichner, Steven L

2004-01-01

Tenofovir disoproxil fumarate (DF) is a potent nucleotide analog reverse transcriptase inhibitor approved for the treatment of human immunodeficiency virus (HIV)-infected adults. The single-dose and steady-state pharmacokinetics of tenofovir were evaluated following administration of tenofovir DF in treatment-experienced HIV-infected children requiring a change in antiretroviral therapy. Using increments of tenofovir DF 75-mg tablets, the target dose was 175 mg/m(2); the median administered dose was 208 mg/m(2). Single-dose pharmacokinetics were evaluated in 18 subjects, and the geometric mean area under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) was 2,150 ng. h/ml and the geometric mean maximum concentration (C(max)) was 266 ng/ml. Subsequently, other antiretrovirals were added to each patient's regimen based upon treatment history and baseline viral resistance results. Steady-state pharmacokinetics were evaluated in 16 subjects at week 4. The steady-state, geometric mean AUC for the 24-h dosing interval was 2,920 ng. h/ml and was significantly higher than the AUC(0- infinity ) after the first dose (P = 0.0004). The geometric mean C(max) at steady state was 302 ng/ml. Tenofovir DF was generally very well tolerated. Steady-state tenofovir exposures in children receiving tenofovir DF-containing combination antiretroviral therapy approached values seen in HIV-infected adults (AUC, approximately 3,000 ng. h/ml; C(max), approximately 300 ng/ml) treated with tenofovir DF at 300 mg.

Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.

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Chen, Wilbur H; Cohen, Mitchell B; Kirkpatrick, Beth D; Brady, Rebecca C; Galloway, David; Gurwith, Marc; Hall, Robert H; Kessler, Robert A; Lock, Michael; Haney, Douglas; Lyon, Caroline E; Pasetti, Marcela F; Simon, Jakub K; Szabo, Flora; Tennant, Sharon; Levine, Myron M

2016-06-01

No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model. Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration. The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001). The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine. NCT01895855. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Pharmacokinetic Effects of Antidrug Antibodies Occurring in Healthy Subjects After a Single Dose of Intravenous Infliximab.

Science.gov (United States)

Ehrenpreis, Eli D

2017-12-01

Infliximab pharmacokinetic studies have been performed in patients receiving chronic infliximab therapy. In these patients, infliximab antidrug antibodies (ADAs) increase infliximab clearance and decrease serum levels and drug efficacy. This study analyzed the pharmacokinetic effect of infliximab ADAs in healthy subjects receiving a single dose of intravenous infliximab. Data were obtained from a single-blind, parallel-group, single-dose study of healthy subjects receiving 5 mg/kg of intravenous SB2 (infliximab biosimilar), EU-sourced Remicade (EU-IFX) or US-sourced Remicade (US-IFX). Serum infliximab was measured at 1, 2, 3, 6, 12, 24, 48, and 72 h and at 5, 7, 14, 21, 28, 42, 56, and 70 days after administration. ADAs were measured pre-dose and at 29 and 71 days. Data from the first ten subjects randomized to each treatment arm were utilized for this study. A two-compartment model of the serum infliximab vs. time curve was developed using nonlinear regression. At 10 weeks, 11 subjects (37%) developed ADAs. ADAs were detected in four subjects after SB2, one subject after EU-IFX, and six subjects after US-IFX infusion. Of these, neutralizing antibodies occurred in one subject after SB2, in no subjects after EU-IFX, and in three subjects after US-IFX infusion. Infliximab clearance was increased in subjects with ADAs vs. those without ADAs (12.89 ± 2.69 vs. 9.90 ± 1.74 ml/h; p ADAs (282.4 ± 56.4 vs. 343.3 ± 61.9 h; p ADAs are common in healthy subjects after a single intravenous dose of infliximab and result in faster infliximab clearance, shorter elimination time, and lower serum infliximab levels. These data confirm that ADAs are common with biologic therapy and significantly impact the efficacy of these drugs.

High-dose buprenorphine: perioperative precautions and management strategies.

Science.gov (United States)

Roberts, D M; Meyer-Witting, M

2005-02-01

Buprenorphine has been in clinical use in anaesthesia for several decades. Recently, the high-dose sublingual formulation (Subutex, Reckitt Benckiser, Slough, U.K.) has been increasingly used as maintenance therapy in opioid dependence, as an alternative to methadone and other pharmacological therapies. Buprenorphine has unique pharmacological properties making it well suited for use as a maintenance therapy in opioid dependence. However, these same properties may cause difficulty in the perioperative management of pain. Buprenorphine is a partial opioid agonist, attenuating the effects of supplemental illicit or therapeutic opioid agonists. As a result of its high receptor affinity, supplemental opioids do not readily displace buprenorphine from the opioid receptor in standard doses. High-dose buprenorphine has an extended duration of action that prolongs both of these effects. The perioperative management of patients stabilized on high-dose buprenorphine and undergoing surgery requires consideration of the likely analgesic requirements. Where possible the buprenorphine should be continued. Pain management should focus on maximizing non-opioid analgesia, local anaesthesia and non-pharmacological techniques. Where pain may not be adequately relieved by these methods, the addition of a full opioid agonist such as fentanyl or morphine at appropriate doses should be considered, accompanied by close monitoring in a high dependency unit. In situations where this regimen is unlikely to be effective, preoperative conversion to morphine or methadone may be an option. Where available, liaison with a hospital-based alcohol and drug service should always be considered.

Dosimetric Effects of Air Pockets Around High-Dose Rate Brachytherapy Vaginal Cylinders

International Nuclear Information System (INIS)

Richardson, Susan; Palaniswaamy, Geethpriya; Grigsby, Perry W.

2010-01-01

Purpose: Most physicians use a single-channel vaginal cylinder for postoperative endometrial cancer brachytherapy. Recent published data have identified air pockets between the vaginal cylinders and the vaginal mucosa. The purpose of this research was to evaluate the incidence, size, and dosimetric effects of these air pockets. Methods and Materials: 25 patients receiving postoperative vaginal cuff brachytherapy with a high-dose rate vaginal cylinders were enrolled in this prospective data collection study. Patients were treated with 6 fractions of 200 to 400 cGy per fraction prescribed at 5 mm depth. Computed tomography simulation for brachytherapy treatment planning was performed for each fraction. The quantity, volume, and dosimetric impact of the air pockets surrounding the cylinder were quantified. Results: In 25 patients, a total of 90 air pockets were present in 150 procedures (60%). Five patients had no air pockets present during any of their treatments. The average number of air pockets per patient was 3.6, with the average total air pocket volume being 0.34 cm 3 (range, 0.01-1.32 cm 3 ). The average dose reduction to the vaginal mucosa at the air pocket was 27% (range, 9-58%). Ten patients had no air pockets on their first fraction but air pockets occurred in subsequent fractions. Conclusion: Air pockets between high-dose rate vaginal cylinder applicators and the vaginal mucosa are present in the majority of fractions of therapy, and their presence varies from patient to patient and fraction to fraction. The existence of air pockets results in reduced radiation dose to the vaginal mucosa.

Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

International Nuclear Information System (INIS)

Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

2016-01-01

In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

Miltefosine Lipid Nanocapsules for Single Dose Oral Treatment of Schistosomiasis Mansoni: A Preclinical Study.

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Maha M Eissa

Full Text Available Miltefosine (MFS is an alkylphosphocholine used for the local treatment of cutaneous metastases of breast cancer and oral therapy of visceral leishmaniasis. Recently, the drug was reported in in vitro and preclinical studies to exert significant activity against different developmental stages of schistosomiasis mansoni, a widespread chronic neglected tropical disease (NTD. This justified MFS repurposing as a potential antischistosomal drug. However, five consecutive daily 20 mg/kg doses were needed for the treatment of schistosomiasis mansoni in mice. The present study aims at enhancing MFS efficacy to allow for a single 20mg/kg oral dose therapy using a nanotechnological approach based on lipid nanocapsules (LNCs as oral nanovectors. MFS was incorporated in LNCs both as membrane-active structural alkylphospholipid component and active antischistosomal agent. MFS-LNC formulations showed high entrapment efficiency (EE%, good colloidal properties, sustained release pattern and physical stability. Further, LNCs generally decreased MFS-induced erythrocyte hemolytic activity used as surrogate indicator of membrane activity. While MFS-free LNCs exerted no antischistosomal effect, statistically significant enhancement was observed with all MFS-LNC formulations. A maximum effect was achieved with MFS-LNCs incorporating CTAB as positive charge imparting agent or oleic acid as membrane permeabilizer. Reduction of worm load, ameliorated liver pathology and extensive damage of the worm tegument provided evidence for formulation-related efficacy enhancement. Non-compartmental analysis of pharmacokinetic data obtained in rats indicated independence of antischistosomal activity on systemic drug exposure, suggesting possible gut uptake of the stable LNCs and targeting of the fluke tegument which was verified by SEM. The study findings put forward MFS-LNCs as unique oral nanovectors combining the bioactivity of MFS and biopharmaceutical advantages of LNCs

Population Pharmacokinetic Modelling of FE 999049, a Recombinant Human Follicle-Stimulating Hormone, in Healthy Women After Single Ascending Doses

DEFF Research Database (Denmark)

Rose, Trine Høyer; Röshammar, Daniel; Erichsen, Lars

2016-01-01

reproductive technologies. Methods: Serum FSH levels were measured following a single subcutaneous FE 999049 injection of 37.5, 75, 150, 225 or 450 IU in 27 pituitary-suppressed healthy female subjects participating in this first-in-human single ascending dose trial. Data was analysed by nonlinear mixed...... volume of distribution (V/F) estimates were found to increase with body weight. Body weight was included as an allometrically scaled covariate with a power exponent of 0.75 for CL/F and 1 for V/F. Conclusions: The single-dose pharmacokinetics of FE 999049 were adequately described by a population...

Effects of single and split doses of cobalt-60 gamma rays and 14 MeV neutrons on mouse stem cell spermatogonia.

Science.gov (United States)

Hacker-Klom, U B; Köhnlein, W; Göhde, W

2000-12-01

The long-term effects of ionizing radiation on male gonads may be the result of damage to spermatogonial stem cells. Doses of 10 cGy to 15 Gy (60)Co gamma rays or 10 cGy to 7 Gy 14 MeV neutrons were given to NMRI mice as single or split doses separated by a 24-h interval. The ratios of haploid spermatids/2c cells and the coefficients of variation of DNA histogram peaks as measures of both the cytocidal and the clastogenic actions of radiation were analyzed by DNA flow cytometry after DAPI staining. The coefficient of variation is not only a statistical examination of the data but is also used here as a measure of residual damage to DNA (i.e. a biological dosimeter). Testicular histology was examined in parallel. At 70 days after irradiation, the relative biological effectiveness for neutrons at 50% survival of spermatogonial stem cells was 3.6 for single doses and 2.8 for split doses. The average coefficient of variation of unirradiated controls of elongated spermatids was doubled when stem cells were irradiated with single doses of approximately 14 Gy (60)Co gamma rays or 3 Gy neutrons and observed 70 days later. Split doses of (60)Co gamma rays were more effective than single doses, doubling DNA dispersion at 7 Gy. No fractionation effect was found with neutrons with coefficients of variation.

Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

International Nuclear Information System (INIS)

Boetter-Jensen, L.; Solongo, S.; Murray, A.S.; Banerjee, D.; Jungner, H.

2000-01-01

We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks and unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only to background radiation. We conclude that unfired materials have considerable potential in retrospective dosimetry

Surface sputtering in high-dose Fe ion implanted Si

International Nuclear Information System (INIS)

Ishimaru, Manabu

2007-01-01

Microstructures and elemental distributions in high-dose Fe ion implanted Si were characterized by means of transmission electron microscopy and Rutherford backscattering spectroscopy. Single crystalline Si(0 0 1) substrates were implanted at 350 deg. C with 120 keV Fe ions to fluences ranging from 0.1 x 10 17 to 4.0 x 10 17 /cm 2 . Extensive damage induced by ion implantation was observed inside the substrate below 1.0 x 10 17 /cm 2 , while a continuous iron silicide layer was formed at 4.0 x 10 17 /cm 2 . It was found that the spatial distribution of Fe projectiles drastically changes at the fluence between 1.0 x 10 17 and 4.0 x 10 17 /cm 2 due to surface sputtering during implantation

8 Gy single-dose radiotherapy is effective in metastatic spinal cord compression: Results of a phase III randomized multicentre Italian trial

International Nuclear Information System (INIS)

Maranzano, Ernesto; Trippa, Fabio; Casale, Michelina; Costantini, Sara; Lupattelli, Marco; Bellavita, Rita; Marafioti, Luigi; Pergolizzi, Stefano; Santacaterina, Anna; Mignogna, Marcello; Silvano, Giovanni; Fusco, Vincenzo

2009-01-01

Background and purpose: In a previous randomized trial we showed that the short-course radiotherapy (RT) regimen of 8 Gy x 2 was feasible in patients with metastatic spinal cord compression (MSCC) and short life expectancy. This phase III trial was planned to determine whether in the same category of patients 8 Gy single-dose is as effective as 8 Gy x 2. Materials and methods: Three hundred and twenty-seven patients with MSCC and short life expectancy were randomly assigned to a short-course of 8 Gy x 2 or to 8 Gy single-dose RT. Median follow-up was 31 months (range, 4-58). Results: A total of 303 (93%) patients are assessable, 150 treated with the short-course and 153 with the single-dose RT. No difference in response was found between the two RT schedules adopted. Median duration of response was 5 and 4.5 months for short-course and single-dose RT (p = 0.4), respectively. The median overall survival was 4 months for all cases. Light acute toxicity was registered in a minority of cases. Late toxicity was never recorded. Conclusions: Both RT schedules adopted were effective. As already shown in several trials evaluating RT regimens in uncomplicated painful bone metastases, also MSCC patients may achieve palliation with minimal toxicity and inconvenience with a single-dose of 8 Gy.

The Effect of Nicotine Administration on Physical and Psychological Signs of Withdrawal Syndrome Induced by Single or Frequent Doses of Morphine in Rats

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Mohammad Allahtavakoli

2012-07-01

Full Text Available Introduction. Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Materials and methods. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later they also received one dose of nicotine 30 min prior to injection of naloxone. In the repeated dose protocol, rats received incremental doses of morphine for 7 days and 24hr after the last dose (the 8th day were given naloxone. However, the nicotine regimen of this group was injected 15 min before the morphine injection, for 4 days, from the 4th to the 7th day. Five minutes after naloxone injection, each rat′s behavior was captured for 30 min, and then physical and psychological signs of withdrawal syndrome were recorded. Data were analyzed by ANOVA followed by Tukey tests and p<0.05 was considered as significant difference. Findings. Results showed that the injection of frequent and single doses of morphine lead to morphine dependency. In single dose protocol, nicotine consumption attenuated the signs of withdrawal syndrome, especially weight of excrement and total withdrawal score. In frequent dose protocol, in addition to these effects, nicotine induced weight loss and place aversion. Conclusion. The inhibitory effects of nicotine on signs of withdrawal syndrome may involve a dopaminergic portion of the central nervous system and is mediated by central nicotinic receptors. There is also a cross-dependence between nicotine and morphine.

A Single-Dose, Single-Period Pharmacokinetic Assessment of an Extended-Release Orally Disintegrating Tablet of Methylphenidate in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder.

Science.gov (United States)

Childress, Ann; Newcorn, Jeffrey; Stark, Jeffrey G; McMahen, Russ; Tengler, Mark; Sikes, Carolyn

2016-08-01

To determine the pharmacokinetic (PK) profile of a proprietary formulation of methylphenidate (MPH) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) in a phase 1 study. Methylphenidate extended-release orally disintegrating tablets (MPH XR-ODTs) combine two technologies in a single-tablet formulation-an extended-release profile that was designed for once-daily dosing in an ODT that does not require water or chewing for ingestion. This was a single-dose, open-label, single-period, single-treatment study, in which 32 children with ADHD who were receiving MPH in doses of 40 or 60 mg before beginning the study each received a 60-mg dose (2 × 30 mg) of MPH XR-ODT. The following plasma PK parameters of MPH were determined for participants grouped by age (6-7, 8-9, 10-12, and 13-17 years old): maximum concentration (Cmax), time to maximum concentration (Tmax), elimination half-life (T½), area under the curve from 0 hours to infinity (AUCinf), oral clearance (CL/F), and volume of distribution in the terminal phase (Vz/F). Safety and tolerability were also assessed. A total of 32 participants received the study drug. For all participants, plasma concentration-time profiles of MPH exhibited a broad peak after administration of MPH XR-ODT through ∼8 hours, indicating extended release from the formulation, followed by an apparent first-order elimination phase. As age increased, MPH exposure decreased and mean estimates of CL/F increased; however, weight-normalized CL/F values were comparable across age groups. Similarly, mean estimates of Vz/F increased with age, but weight-normalization decreased differences across age groups, with the exception of the youngest age group, which had higher values. All adverse events (AEs) were mild. This XR-ODT formulation of MPH demonstrated weight-normalized clearance rates that were consistent across all age groups, a PK profile consistent with once-daily dosing, and an AE profile consistent with

A high performance liquid chromatographic assay of Mefloquine in saliva after a single oral dose in healthy adult Africans

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Gbotosho Grace O

2012-02-01

Full Text Available Abstract Background Mefloquine-artesunate is a formulation of artemisinin based combination therapy (ACT recommended by the World Health Organization and historically the first ACT used clinically. The use of ACT demands constant monitoring of therapeutic efficacies and drug levels, in order to ensure that optimum drug exposure is achieved and detect reduced susceptibility to these drugs. Quantification of anti-malarial drugs in biological fluids other than blood would provide a more readily applicable method of therapeutic drug monitoring in developing endemic countries. Efforts in this study were devoted to the development of a simple, field applicable, non-invasive method for assay of mefloquine in saliva. Methods A high performance liquid chromatographic method with UV detection at 220 nm for assaying mefloquine in saliva was developed and validated by comparing mefloquine concentrations in saliva and plasma samples from four healthy volunteers who received single oral dose of mefloquine. Verapamil was used as internal standard. Chromatographic separation was achieved using a Hypersil ODS column. Results Extraction recoveries of mefloquine in plasma or saliva were 76-86% or 83-93% respectively. Limit of quantification of mefloquine was 20 ng/ml. Agreement between salivary and plasma mefloquine concentrations was satisfactory (r = 0.88, p Conclusion Disposition of mefloquine in saliva paralleled that in plasma, making salivary quantification of mefloquine potentially useful in therapeutic drug monitoring.

High-temperature absorbed dose measurements in the megagray range

International Nuclear Information System (INIS)

Balian, P.; Ardonceau, J.; Zuppiroli, L.

1988-01-01

Organic conductors of the tetraselenotetracene family have been tested as ''high-temperature'' absorbed dose dosimeters. They were heated up to 120 0 C and irradiated at this temperature with 1-MeV electrons in order to simulate, in a short time, a much longer γ-ray irradiation. The electric resistance increase of the crystal can be considered a good measurement of the absorbed dose in the range 10 6 Gy to a few 10 8 Gy and presumably one order of magnitude more. This dosimeter also permits on-line (in-situ) measurements of the absorbed dose without removing the sensor from the irradiation site. The respective advantages of organic and inorganic dosimeters at these temperature and dose ranges are also discussed. In this connection, we outline new, but negative, results concerning the possible use of silica as a high-temperature, high-dose dosimeter. (author)

Feasibility of low-dose contrast medium high pitch CT angiography for the combined evaluation of coronary, head and neck arteries.

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Zhiwei Wang

Full Text Available PURPOSE: To evaluate the image quality and radiation dose of combined heart, head, and neck CT angiography (CTA using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol, compared with single coronary CTA. MATERIALS AND METHODS: 151 consecutive patients were prospectively included and randomly divided into three groups. Group 1 (n = 47 underwent combined heart, neck, and head CTA using prospectively ECG-triggered high-pitch spiral (Flash scan protocol with a single-phase intravenous injection of iodinated contrast and saline flush; Group 2 (n = 51 underwent single coronary CTA with Flash scan protocol; and Group 3 (n = 53 underwent single coronary CTA with prospective sequence scan protocol. All patients were examined on a dual source CT (Definition FLASH. The image quality was determined for each CT study. RESULTS: Patients of scanning protocol Group 1, 2, and 3 showed no significant differences in age, sex, heart rates, and BMI. Evaluation of coronary artery image quality showed comparable results in the three scanning protocol groups on a per patient-based analysis. In group 1, image quality was found to be sufficient to be diagnostic in all arterial segments of carotid arteries. The mean dose-length product (DLP for group 1 was 256.3±24.5 mGy×cm and was significantly higher in comparison with group 2 (93.4±19.9 mGy×cm; p < 0.001. However, there was no significant difference of DLP between group 1 and group 3 (254.1±69.9 mGy×cm. CONCLUSIONS: The combined heart, neck, and head arteries scan using prospectively electrocardiography (ECG-triggered high-pitch spiral scan protocol in 1 single examination resulted in an excellent opacification of the aorta, the carotid arteries, and the coronary arteries and provided a good image quality with low radiation dose.

Palonosetron-A Single-Dose Antiemetic Adjunct for Hepatic Artery Radioembolization: A Feasibility Study

International Nuclear Information System (INIS)

Siddiqi, Nasir H.; Khan, Atif J.; Devlin, Phillip M.

2009-01-01

Nausea and vomiting may occur in a significant minority of patients following hepatic artery embolization with yttrium-90 spheres (K. T. Sato et al. Radiology 247:507-515, 2008). This encumbers human and economic resources and undercuts the assertion that it is as a well-tolerated outpatient treatment. A single intravenous dose of palonosetron HCl was administered before hepatic artery embolization with yttrium-90 spheres to ameliorate posttreatment nausea and vomiting, in 23 consecutive patients. The patients were discharged the day of procedure on oral antiemetics, steroids, and blockers of gastric acid release. All patients had clinical and laboratory evaluation at 2 weeks after the procedure. The data were gathered and reviewed retrospectively. At 2-week follow-up, none reported significant nausea, vomiting, additional antiemetic use, need for parenteral therapy, hospital readmission, or palonosetron-related side effects. All patients recovered from postembolization symptoms within a week after treatment. In conclusion, this retrospective study suggests that single-dose palonosetron is feasible, safe, and effective for acute and delayed nausea and vomiting in this group of patients. The added cost may be offset by benefits.

Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

International Nuclear Information System (INIS)

Pitkaenen, M.A.; Hopewell, J.W.

1985-01-01

Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

Automated high-dose rate brachytherapy treatment planning for a single-channel vaginal cylinder applicator

Science.gov (United States)

Zhou, Yuhong; Klages, Peter; Tan, Jun; Chi, Yujie; Stojadinovic, Strahinja; Yang, Ming; Hrycushko, Brian; Medin, Paul; Pompos, Arnold; Jiang, Steve; Albuquerque, Kevin; Jia, Xun

2017-06-01

High dose rate (HDR) brachytherapy treatment planning is conventionally performed manually and/or with aids of preplanned templates. In general, the standard of care would be elevated by conducting an automated process to improve treatment planning efficiency, eliminate human error, and reduce plan quality variations. Thus, our group is developing AutoBrachy, an automated HDR brachytherapy planning suite of modules used to augment a clinical treatment planning system. This paper describes our proof-of-concept module for vaginal cylinder HDR planning that has been fully developed. After a patient CT scan is acquired, the cylinder applicator is automatically segmented using image-processing techniques. The target CTV is generated based on physician-specified treatment depth and length. Locations of the dose calculation point, apex point and vaginal surface point, as well as the central applicator channel coordinates, and the corresponding dwell positions are determined according to their geometric relationship with the applicator and written to a structure file. Dwell times are computed through iterative quadratic optimization techniques. The planning information is then transferred to the treatment planning system through a DICOM-RT interface. The entire process was tested for nine patients. The AutoBrachy cylindrical applicator module was able to generate treatment plans for these cases with clinical grade quality. Computation times varied between 1 and 3 min on an Intel Xeon CPU E3-1226 v3 processor. All geometric components in the automated treatment plans were generated accurately. The applicator channel tip positions agreed with the manually identified positions with submillimeter deviations and the channel orientations between the plans agreed within less than 1 degree. The automatically generated plans obtained clinically acceptable quality.

High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

Science.gov (United States)

Kaschieva, S.; Angelov, Ch; Dmitriev, S. N.

2018-03-01

The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.

A novel theory of radiation damage at high doses

International Nuclear Information System (INIS)

Seeger, A.; Stuttgart Univ.

1989-01-01

Deviations of radiation damage (in the case of metals usually monitored by the residual electrical resistivity) from proportionality with the irradiation dose have so far been analysed almost exclusively in terms of extensions of models originally developed for small doses. The present theory considers the opposite limit i.e. the quasi-saturated state. It is argued that at high doses the Lueck-Sizmann effect may result in a self-organization of clusters of vacancies and self-interstitials, forming a heterogeneous froth. Possible structures of this froth and its effect on the electrical resistivity of metals are discussed. The model is shown to account for the dependence of the ''saturation resistivity'' on the nature of the irradiation as well as for several other hitherto poorly explained observations. Among them are the electrical-resistivity variation induced by high-dose irradiation with heavy ions, the amorphization of certain alloys by high-dose electron irradiation, and the occurrence of ordered arrays of stacking-fault tetrahedra after in-situ irradiations in high-voltage electron microscopes. (author)

Study on dose-effect relationship of radiation-induced DNA damage using single cell gel electrophoresis

International Nuclear Information System (INIS)

Liu Qiang; Jiang Enhai; Li Jin; Tang Weisheng; Wang Zhiquan; Zhao Yongcheng; Fan Feiyue

2006-01-01

Objective: To explore a new, simple and quick radiation biodosimeter, which can be applied to estimate biological dose in case of radiation accident. Methods: DNA double-strand break were detected using neutral single cell gel electrophoresis (SCGE), and all the indexes of comet assay including HDNA%, TDNA%, CL, TL, TM, and OTM were analyzed by CASP (Comet Assay Software Project). The curve of dose-effect was fitted using SPSS 12.0 software. Results: Statistically significant dose-effect relationships were observed in all the indexes of comet assay, OTM was superior to other indexes. Conclusions: Application of neutral comet assay combined with CASP analysis could serve as a new radiation biodosimeter. (authors)

Single-dose FTY720 pharmacokinetics, food effect, and pharmacological responses in healthy subjects

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Kovarik, John M; Schmouder, Robert; Barilla, Denise; Wang, Yibin; Kraus, Gerolf

2004-01-01

Aims FTY720 is a sphingosine-1-phosphate receptor agonist that redirects lymphocytes from the circulation to lymph nodes without impairing lymphocyte function. It is being developed as an immunomodulator for the prevention of acute rejection after organ transplantation. This study was performed to provide guidance on administration with respect to meals and to measure pharmacologic responses in healthy subjects. Methods In this randomized, two-period, crossover study, 14 healthy subjects received placebo on day −1 of each period with baseline circadian measurements of lymphocyte count and heart rate. Subjects subsequently received a single 1 mg oral dose of FTY720 on day 1 under fasting conditions and after a high fat meal. Blood FTY720 concentrations, lymphocyte count, and supine heart rate were assessed over an 8 day period after each FTY720 dose. The effect of food on FTY720 pharmacokinetics was assessed by standard bioequivalence testing. Results Both the peak concentration (0.65 ± 0.17 vs 0.64 ± 0.18 ng ml−1) and total exposure (AUC 149 ± 65 vs 139 ± 43 ng ml−1 h) did not differ significantly between fasting and fed states, respectively. The corresponding fed/fasting ratios and 90% confidence intervals were 1.00 (0.86, 1.17) for Cmax and 0.98 (0.86, 1.11) for AUC. Under both treatment conditions peripheral blood lymphocyte count decreased from baseline by 38 ± 9% over the first 2 days postdose and then increased towards predose values over the subsequent week. Whereas a circadian rhythm in supine heart rate was preserved in the presence of FTY720, the heart rate vs time curve was shifted downwards by 10% over the first day postdose and then recovered to prestudy values by days 3–5 postdose. These changes were asymptomatic. Conclusions Single 1 mg doses of FTY720 were well tolerated in healthy subjects and elicited a moderate decrease in peripheral blood lymphocyte count and a transient decrease in heart rate consistent with its pharmacological

Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

International Nuclear Information System (INIS)

Turesson, I.

1990-01-01

The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

High-dose mode of mortality in Tribolium: A model system for study of radiation injury and repair in non-proliferative tissues

International Nuclear Information System (INIS)

Cheng, Chihing Christina.

1989-01-01

With appropriate doses of ionizing radiation, both the acute, or lethal-midlethal, dose-independent pattern of mortality, and the hyperacute, dose-dependent pattern, were demonstrated within a single insect genus (Tribolium). This demonstration provides resolution of apparently contradictory reports of insect radiation responses in terms of doses required to cause lethality and those based on survival time as a function of dose. A dose-dependent mortality pattern was elicited in adult Tribolium receiving high doses, viz., 300 Gy or greater; its time course was complete in 10 days, before the dose-independent pattern of mortality began. Visual observations of heavily-irradiated Tribolium suggested neural and/or neuromuscular damage, as had been previously proposed by others for lethally-irradiated wasps, flies, and mosquitoes. Results of experiments using fractionated high doses supported the suggestion that the hyperacute or high-dose mode of death is the result of damage to nonproliferative tissues. Relative resistance of a strain to the hyperacute or high-dose mode of death was not correlated with resistance to the midlethal mode, which is believed to be the result of damage to the proliferative cells of the midgut. Using the high-dose mode of death as a model of radiation damage to nonproliferative tissues, the effects of age, and of a moderate priming dose were assessed. Beetles showed age-related increase in sensitivity to the high-dose mode of death, suggesting a decline in capacity to repair radiation damage to postmitotic tissue. This correlated with a decrease (50%) in the amount of repair reflected in the sparing effect of dose-fractionation (SDF) between the age of 1 to 3 months. The age related increase in radiosensitivity was reduced by a moderate priming dose (40 or 65 Gy) given at a young age

Statistical behavior of high doses in medical radiodiagnosis; Comportamento estatistico das altas doses em radiodiagnostico medico

Energy Technology Data Exchange (ETDEWEB)

Barboza, Adriana Elisa, E-mail: adrianaebarboza@gmail.com, E-mail: elisa@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2014-07-01

This work has as main purpose statistically estimating occupational exposure in medical diagnostic radiology in cases of high doses recorded in 2011 at national level. For statistical survey of this study, doses of 372 IOE's diagnostic radiology in different Brazilian states were evaluated. Data were extracted from the work of monograph (Research Methodology Of High Doses In Medical Radiodiagnostic) that contains the database's information Sector Management doses of IRD/CNEN-RJ, Brazil. The identification of these states allows the Sanitary Surveillance (VISA) responsible, becomes aware of events and work with programs to reduce these events. (author)

Synthetic CT: Simulating low dose single and dual energy protocols from a dual energy scan

International Nuclear Information System (INIS)

Wang, Adam S.; Pelc, Norbert J.

2011-01-01

Purpose: The choice of CT protocol can greatly impact patient dose and image quality. Since acquiring multiple scans at different techniques on a given patient is undesirable, the ability to predict image quality changes starting from a high quality exam can be quite useful. While existing methods allow one to generate simulated images of lower exposure (mAs) from an acquired CT exam, the authors present and validate a new method called synthetic CT that can generate realistic images of a patient at arbitrary low dose protocols (kVp, mAs, and filtration) for both single and dual energy scans. Methods: The synthetic CT algorithm is derived by carefully ensuring that the expected signal and noise are accurate for the simulated protocol. The method relies on the observation that the material decomposition from a dual energy CT scan allows the transmission of an arbitrary spectrum to be predicted. It requires an initial dual energy scan of the patient to either synthesize raw projections of a single energy scan or synthesize the material decompositions of a dual energy scan. The initial dual energy scan contributes inherent noise to the synthesized projections that must be accounted for before adding more noise to simulate low dose protocols. Therefore, synthetic CT is subject to the constraint that the synthesized data have noise greater than the inherent noise. The authors experimentally validated the synthetic CT algorithm across a range of protocols using a dual energy scan of an acrylic phantom with solutions of different iodine concentrations. An initial 80/140 kVp dual energy scan of the phantom provided the material decomposition necessary to synthesize images at 100 kVp and at 120 kVp, across a range of mAs values. They compared these synthesized single energy scans of the phantom to actual scans at the same protocols. Furthermore, material decompositions of a 100/120 kVp dual energy scan are synthesized by adding correlated noise to the initial material

A quantitative assessment of changes in the dermal fibroblast population of pig skin after single doses of X-rays

International Nuclear Information System (INIS)

Hamlet, R.; Hopewell, J.W.

1988-01-01

Changes in the density of fibroblast nuclei in reticular dermis of pigs was studied from 6 to 104 weeks after a single dose of 15.4 Gy of X-rays. The largest decrease in fibroblasts occurred between 12 and 26 weeks after irradiation; after this there was only a slight fall in fibroblast number until 104 weeks when observations ceased. At 26 weeks and later times after irradiation reduction in the density of fibroblast nuclei in the reticular dermis was dose-dependent for single doses in the range 8.0-20.7 Gy. The dose-response curve had an initial shoulder, after which the fall in the fibroblast nuclear density was linearly related to dose. Data obtained between 26 weeks and 104 weeks after irradiation, could be fitted by the same dose-response curve. The fall in the counts of fibroblast nuclei was compared with earlier studies. The loss of fibroblasts occurred after an initial reduction in blood flow in the pig skin but was concomitant with general reduction in dermal thickness. (author)

Treatment of chronic spontaneous urticaria with a single dose of omalizumab: A study of four cases

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Radhakrishnan Subramaniyan

2016-01-01

Full Text Available Background: Chronic spontaneous urticaria (CSU has a detrimental effect on patients′ emotional and physical quality of life. Omalizumab, an anti-immunoglobulin E humanized monoclonal antibody, has been shown to be very effective in the treatment of refractory chronic urticaria patients but may not be an economically viable option for all CSU patients. However, we present a case series where a single dose of omalizumab gave sustained relief of symptoms in patients with CSU, which may be an economical option. Aims: The aim of this study is to assess the efficacy of a single dose of omalizumab in the treatment of CSU. Materials and Methods: Four patients of CSU whose disease was not controlled with four times the licensed dose of tablet fexofenadine 180 mg were exhibited one subcutaneous injection of omalizumab and were followed up at 4 weekly intervals for 24 weeks for Weekly Urticaria Activity Score 7 (UAS7 and Dermatology Life Quality Index (DLQI. Results: A sharp decline in UAS7 and DLQI was documented in 7-10 days. The decline was maintained up to 16 weeks in one case and 20 weeks in the other three cases. Both the scores at the end of the follow-up period of 24 weeks were better than the pre-omalizumab scores. Conclusion: The results of this case series indicate the efficacy of a single-dose omalizumab in treating moderate to severe refractory CSU. Further studies are required to identify the minimum frequency of administering omalizumab to effectively control CSU. This would greatly reduce the cost of this novel therapy.

Effect of a single dose of dextromethorphan on psychomotor performance and working memory capacity.

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Al-Kuraishy, Hayder M; Al-Gareeb, Ali I; Ashor, Ammar Waham

2012-04-01

Previous studies show that the prolonged use of dextromethorphan produces cognitive deterioration in humans. The aim of this study was to investigate the effect of a single dose of dextroemthrophan on psychomotor performance and working memory capacity. This is a randomized, double-blind, controlled, and prospective study. Thirty-six (17 women, 19 men) medical students enrolled in the study; half of them (7 women, 11 men) were given placebo, while the other half (10 women, 8 men) received dextromethorphan. The choice reaction time, critical flicker fusion threshold, and N-back working memory task were measured before and after 2 h of taking the drugs. Dextromethorphan showed a significant deterioration in the 3-back working memory task (P0.05). On the other hand, placebo showed no significant changes as regards the choice reaction time, critical flicker fusion threshold, and N-back working memory task (P>0.05). A single dose of dextromethorphan has no effect on attention and arousal but may significantly impair the working memory capacity.

Study on fine quartz pre-dose techniques

International Nuclear Information System (INIS)

Leung, P.L.; Stokes, M.J.; Wang Weida; Xia Junding

1996-01-01

When using the pre-dose technique in ceramic dating, it is essential to add a calibration dose and to eliminate the background dose. For doing this measurement the sample requires multiple activation following multiple administration of a test dose to induce simulated 'ancient' thermoluminescence (TL). However, the procedures introduce many factors that are difficultly corrected. The authors compare existing two kinds of measurement procedures and proposes a new procedure involving single activation following a single test dose administration. An experiment using the single activation procedure is carried out with natural fine quartz where the results obtained exhibit only 0.07 relative error. It appears that this new procedure increases the precision of the ancient TL measurement by about 0.04 and 0.11 over those of existing two kinds of procedures. In addition this method can give realistic values in TL dating for relatively 'young' samples aged tens to hundreds of years where the standard high temperature TL method is relatively insensitive

Distribution of 99Tcm-rh-Annexin vin tumor and expression relationship of bcl-2, bax after a single dose of chemotherapy

International Nuclear Information System (INIS)

Zhang Xin; Li Yaming; Zhang Yanjun; Tao Li; Zhu Yi; Yang Chun; Ji Xiaopeng; Zhao Ming; Tian Aijuan; Zhang Jianying; Zhao Zhenzhen

2007-01-01

The expression of bcl-2 and bax after the single dose of chemotherapy with 99 Tc m -rh-Annexin V as the tracer of tumor apoptosis imaging is studied. tumor cell apoptosis is examined by TUNEL methods, and the expression of bcl-2 and bax in tumor are determined by immunohistochemical methods. Single dose of chemotherapy significantly increased the tumor uptake of 99 Tc m -rh-annexin V and the positive number of TUNEL, as well as the expression of bax (P 99 Tc m -rh-annexin V in tumor reflectes not only the degree of apoptosis of tumor cells, but also the change of bax expression after the single dose of chemotherapy. (authors)

Effects of single dose X-irradiation on the guinea-pig spinal cord

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Knowles, J F [Medical Research Council, Harwell (UK). Radiobiological Research Unit

1981-09-01

Lumbar or cervical regions of the guinea-pig spinal cord were irradiated with a single dose of 250 kV X-rays. The latency for paralysis, whether of hind- or fore-limbs, and the histopathology of the radiation-induced cord lesions depended critically on the radiation dose. There were definite but only minor differences between the reactions of lumbar and cervical cord to the same radiation dose. After 30 or 40 Gy there was white matter necrosis but after 20 Gy widespread demyelination associated with vacuolar spaces occurred. After irradiation of the lumbar cord with 30-40 Gy, the lesions in the guinea-pig differed from those reported in the rat. White-matter necrosis in the guinea-pig cord was only occasionally associated with spinal nerve root necrosis, whereas in the rat, nerve-root necrosis with sparing of the white matter was the main lesion. After 20 Gy to the cervical or lumbar cord the guinea-pig showed widespread demyelination and vacuolation whereas in rats vascular lesions were the main result.

Effects of low priming dose irradiation on cell cycle arrest of HepG2 cells caused by high dose irradiation

International Nuclear Information System (INIS)

Xia Jingguang; Jin Xiaodong; Chinese Academy of Sciences, Beijing; Li Wenjian; Wang Jufang; Guo Chuanling; Gao Qingxiang

2005-01-01

Human hepatoma cells hepG2 were irradiated twice by 60 Co γ-rays with a priming dose of 5 cGy and a higher dose of 3 Gy performed 4h or 8h after the low dose irradiation. Effects of the priming dose irradiation on cell cycle arrest caused by high dose were examined with flow cytometry. Cells in G 2 /M phase accumulated temporarily after the 5 cGy irradiation, and proliferation of tumor cells was promoted significantly by the low dose irradiation. After the 3 Gy irradiation, G 2 phase arrest occurred, and S phase delayed temporally. In comparison with 3 kGy irradiation only, the priming dose delivered 4h prior to the high dose irradiation facilitated accumulation of hepG2 cells in G 2 /M phase, whereas the priming dose delivered 8h prior to the high dose irradiation helped the cells to overcome G 2 arrest. It was concluded that effects of the priming dose treatment on cell cycle arrest caused by high dose irradiation were dependent on time interval between the two irradiations. (authors)

A clinical comparison of high dose and low dose of Suxamethonium

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RK Yadav

2014-01-01

Full Text Available Background: Suxamethonium having its rapid onset and short duration of action makes this drug unique amongst the neuromuscular blocking drugs described so far. However, use of suxamethonium is associated with a large number of undesirable side effects. Objective: To evaluate clinical effects of high and low dose of suxamethonium and to determine whether lower dose of suxamethonium can be used for any beneficial effects in terms of its various adverse effects e.g. cardiovascular responses, post-operative muscle pains and intraocular pressure. Methods: A total of 100 patients were included in this prospective study. All these patients on preoperative clinical evaluation were assessed to have adequate airway. All the patients were divided in two groups, low dose group (group I and High dose group (group II with 50 patients in each at random. A standard anesthetic technique was adhered to all the patients and following parameters were observed on comparative basis: a. Fasciculation and post operative myalgia. b. Cardiovascular effects, c. Intraocular pressure. Observation: The incidence of post Suxamethonium pain was significantly greater in group II. Increase in heart rate from baseline was significant in both groups. There was no significant difference between the two groups in the diastolic pressure but rise in systolic blood pressure was significant at all assessment times in both groups. This rise from control was statistically significant. Conclusion: Suxamethonium can be used in lower doses (0.5 mg/kg in elective cases without airway compromise. It gives benefits of reduced muscle pains, cardiovascular responses and intraocular hypertension. Journal of College of Medical Sciences-Nepal, 2013, Vol-9, No-2, 1-8 DOI: http://dx.doi.org/10.3126/jcmsn.v9i2.9677

Administration of single-dose GnRH agonist in the luteal phase in ICSI cycles: a meta-analysis

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Oliveira João

2010-09-01

Full Text Available Abstract Background The effects of gonadotrophin-releasing hormone agonist (GnRH-a administered in the luteal phase remains controversial. This meta-analysis aimed to evaluate the effect of the administration of a single-dose of GnRH-a in the luteal phase on ICSI clinical outcomes. Methods The research strategy included the online search of databases. Only randomized studies were included. The outcomes analyzed were implantation rate, clinical pregnancy rate (CPR per transfer and ongoing pregnancy rate. The fixed effects model was used for odds ratio. In all trials, a single dose of GnRH-a was administered at day 5/6 after ICSI procedures. Results All cycles presented statistically significantly higher rates of implantation (P Conclusions These findings demonstrate that the luteal-phase single-dose GnRH-a administration can increase implantation rate in all cycles and CPR per transfer and ongoing pregnancy rate in cycles with GnRH antagonist ovarian stimulation protocol. Nevertheless, by considering the heterogeneity between the trials, it seems premature to recommend the use of GnRH-a in the luteal phase. Additional randomized controlled trials are necessary before evidence-based recommendations can be provided.

A second dose of kisspeptin-54 improves oocyte maturation in women at high risk of ovarian hyperstimulation syndrome: a Phase 2 randomized controlled trial.

Science.gov (United States)

Abbara, Ali; Clarke, Sophie; Islam, Rumana; Prague, Julia K; Comninos, Alexander N; Narayanaswamy, Shakunthala; Papadopoulou, Deborah; Roberts, Rachel; Izzi-Engbeaya, Chioma; Ratnasabapathy, Risheka; Nesbitt, Alexander; Vimalesvaran, Sunitha; Salim, Rehan; Lavery, Stuart A; Bloom, Stephen R; Huson, Les; Trew, Geoffrey H; Dhillo, Waljit S

2017-09-01

Can increasing the duration of LH-exposure with a second dose of kisspeptin-54 improve oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS)? A second dose of kisspeptin-54 at 10 h following the first improves oocyte yield in women at high risk of OHSS. Kisspeptin acts at the hypothalamus to stimulate the release of an endogenous pool of GnRH from the hypothalamus. We have previously reported that a single dose of kisspeptin-54 results in an LH-surge of ~12-14 h duration, which safely triggers oocyte maturation in women at high risk of OHSS. Phase-2 randomized placebo-controlled trial of 62 women at high risk of OHSS recruited between August 2015 and May 2016. Following controlled ovarian stimulation, all patients (n = 62) received a subcutaneous injection of kisspeptin-54 (9.6 nmol/kg) 36 h prior to oocyte retrieval. Patients were randomized 1:1 to receive either a second dose of kisspeptin-54 (D; Double, n = 31), or saline (S; Single, n = 31) 10 h thereafter. Patients, embryologists, and IVF clinicians remained blinded to the dosing allocation. Study participants: Sixty-two women aged 18-34 years at high risk of OHSS (antral follicle count ≥23 or anti-Mullerian hormone level ≥40 pmol/L). Setting: Single centre study carried out at Hammersmith Hospital IVF unit, London, UK. Primary outcome: Proportion of patients achieving an oocyte yield (percentage of mature oocytes retrieved from follicles ≥14 mm on morning of first kisspeptin-54 trigger administration) of at least 60%. Secondary outcomes: Reproductive hormone levels, implantation rate and OHSS occurrence. A second dose of kisspeptin-54 at 10 h following the first induced further LH-secretion at 4 h after administration. A higher proportion of patients achieved an oocyte yield ≥60% following a second dose of kisspeptin-54 (Single: 14/31, 45%, Double: 21/31, 71%; absolute difference +26%, CI 2-50%, P = 0.042). Patients receiving two doses of kisspeptin-54 had a variable LH

Fluralaner as a single dose oral treatment for Caparinia tripilis in a pygmy African hedgehog.

Science.gov (United States)

Romero, Camilo; Sheinberg Waisburd, Galia; Pineda, Jocelyn; Heredia, Rafael; Yarto, Enrique; Cordero, Alberto M

2017-12-01

African pygmy hedgehogs (Atelerix albiventris) are popular pets belonging to the Erinaceidae family of spined mammals. Amongst the most common skin diseases occurring in this species is infestation caused by the mite Caparinia spp. Due to their skin anatomy and spiny coat, detection of skin lesions in these hedgehogs can be difficult. This may result in delays in seeking medical care, which may lead to secondary bacterial infection and self-inflicted trauma. Multiple therapies have been used in the treatment of this skin condition including ivermectin, amitraz, fipronil and selamectin. A drug which could be administered as a single oral dose would be advantageous to these pets and their owners. To evaluate the effect of a single oral dose (15 mg/kg) of fluralaner on Caparinia tripilis infestation in the African pygmy hedgehog. A 10-month-old African pygmy hedgehog weighing 184 g. Response to treatment was monitored by dermatological examination and superficial skin scrapings repeated at 7, 14, 21, 30, 60, 90 and 120 days following fluralaner administration. On Day 7 after treatment, adult mites were observed exhibiting normal movement. On Day 14, only dead mites were observed. No life stages of the mites were found after Day 21. A single oral dose at 15 mg/kg of fluralaner was effective within 21 days after treatment for capariniasis in this case. Further studies are required to evaluate the drug's safety and toxicology in hedgehogs, and to confirm efficacy. © 2017 ESVD and ACVD.

Frequency of wound infection in non-perforated appendicitis with use of single dose perforative antibiotics

International Nuclear Information System (INIS)

Ali, K.; Latif, H.; Ahmad, S.

2015-01-01

Antibiotics are used both pre and post-operatively in acute appendicitis for preventing wound infection. It has been observed that the routine use of post-operative antibiotics is not necessary in cases of non-perforated appendicitis as only prophylactic antibiotics are sufficient to prevent wound infection. The aim of this study was to see the frequency of wound infection in non-perforated appendicitis with single dose preoperative antibiotics only. Method: This observational study was conducted at the Department of Surgery, Ayub Medical College, Abbottabad from May to November 2014. A total of 121 patients with non-perforated appendicitis were included in the study. Only single dose preoperative antibiotics were used. The patients were followed for wound infection till 8th post-operative day. Results: 121 patients, 56(46.28%) male and 65(53.72%) female were included in the study. The mean age of patients was 27.41 ± 7.12 years with an age range of 18 to 45 years. In the entire series, 7(5.78%) patients developed wound infection. The infection was minor which settled with conservative therapy. Prophylactic antibiotics were found efficacious in 114(94.21%) patients. There was no significant association between wound infection and age and gender. Conclusion: Single dose preoperative antibiotics were found effective in controlling post-operative wound infection without the need of extending the antibiotics to post-operative period in cases of non-perforated appendicitis. (author)

Efficacy of a single dose of milbemycin oxime/praziquantel combination tablets, Milpro(®), against adult Echinococcus multilocularis in dogs and both adult and immature E. multilocularis in young cats.

Science.gov (United States)

Cvejic, Dejan; Schneider, Claudia; Fourie, Josephus; de Vos, Christa; Bonneau, Stephane; Bernachon, Natalia; Hellmann, Klaus

2016-03-01

Two single-site, laboratory, negatively controlled, masked, randomised dose confirmation studies were performed: one in dogs, the other in cats. After a period of acclimatisation, both the dogs and cats were orally infected with Echinococcus multilocularis protoscoleces. In the dog study, 10 dogs received a single dose of Milpro® tablets at a minimum dose of 0.5 mg/kg milbemycin oxime and 5 mg/kg praziquantel 18 days post-infection and 10 dogs received no treatment. In the cat study, 10 cats received a single dose of Milpro® tablets at a minimum dose of 2 mg/kg milbemycin oxime and 5 mg/kg praziquantel 7 days post-infection, 10 cats received a single dose of the treatment 18 days post-infection and 10 cats remained untreated. In both studies, intestinal worm counts were performed 23 days post-infection at necropsy. No worms were retrieved from any of the 30 treated animals. Nine of 10 control dogs had multiple worms (geometric mean 91, arithmetic mean 304) and all 10 control cats had multiple worms (geometric mean 216, arithmetic mean 481). The difference in worm counts between all three treated groups and their controls was highly significant (ANOVA p values of log transformed data dogs and cats as well as for elimination of immature E. multilocularis in cats as evidenced by the effectiveness of treatment 7 days post-infection. The treatments were well accepted and tolerated, and there were no adverse drug reactions observed.

Low dose radiation exposure and atherosclerosis in ApoE-/- mice

International Nuclear Information System (INIS)

Mitchel, R.E.J.; Hasu, M.; Bugden, M.; Wyatt, H.; Little, M.; Hildebrandt, G.; Priest, N.D.; Whitman, S.C.

2010-01-01

The hypothesis that single low dose exposures (0.025-0.5 Gy) to low LET radiation, given at either high (240 mGy/min) or low (1 mGy/min) dose rate, would promote aortic atherosclerosis was tested in female C57BI/6 mice genetically predisposed to this disease (ApoE-/-). Mice were exposed either at early stage disease (2 months of age) and examined 3 or 6 months later, or at late stage disease (8 months of age) and examined 2 or 4 months later. Compared to unexposed controls, all doses given at low or high dose rate at early stage disease had significant inhibitory effects on lesion growth and, at 25 or 50 mGy, on lesion frequency. No dose given at low dose rate had any effect on total serum cholesterol, but this was elevated by every dose given at high dose rate. Exposures at low dose rate had no effect on the percentage of lesion lipids contained within macrophages, and, at either high or low dose rate, had no significant effect on lesion severity. Exposure at late stage disease, to any dose at high dose rate, had no significant effect on lesion frequency, but at low dose rate some doses produced a small transient increase in this frequency. Exposure to low doses at low, but not high dose rate, significantly, but transiently reduced average lesion size, and at either dose rate transiently reduced lesion severity. Exposure to any dose at low dose rate (but not high dose rate) resulted in large and persistent decreases in serum cholesterol. These data indicate that a single low dose exposure, depending on dose and dose rate, generally protects against various measures of atherosclerosis in genetically susceptible mice. This result contrasts with the known, generally detrimental effects of high doses on this disease in the same mice, suggesting that a linear extrapolation of risk from high doses is not appropriate. (author)

Effect of single oral dose of tramadol on gastric secretions pH

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Khan Mueen Ullah

2015-01-01

Full Text Available Background: Tramadol is an atypical analgesic agent. It has been shown that intramuscular or intravenous injection tramadol is able to inhibit M3 muscarinic receptors. Tramadol is able to mediate smooth muscles contraction and glandular secretions. We have evaluated the effects of single oral dose of tramadol given preoperatively on gastric juices pH in patients electively scheduled for laparoscopic cholecystectomy. Materials and Methods: Sixty adult, American Society of Anesthesiologist I and II patients scheduled for laparoscopic cholecystectomy were included in the study. Patients were randomly assigned to receive either placebo (n = 30 or oral tramadol 50 mg (n = 30. General anesthesia was induced using propofol, fentanyl and cisatracurium. After induction of anesthesia 5 ml of gastric fluid was aspirated through orogastric tube. The gastric fluid pH was measured using pH meter. Result: There was no significant difference in the pH between the groups. Gastric pH of the placebo and tramadol groups was 1.97 versus 1.98 (P = 0.092 respectively. Conclusion: Preoperatively single oral dose of tramadol was unable to elevate the desired level of gastric acid secretions pH (>2.5. This may be due to pharmacokinetic disparity between the analgesic and pH elevating properties of tramadol.

Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline

DEFF Research Database (Denmark)

Kaae, Rikke; Agertoft, Lone; Pedersen, Sören

2004-01-01

OBJECTIVES: To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children. METHODS: Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxi...

Effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells

International Nuclear Information System (INIS)

Hochberg, Z.; Kuten, A.; Hertz, P.; Tatcher, M.; Kedar, A.; Benderly, A.

1983-01-01

Cranial irradiation has been shown to impair growth hormone secretion in children. In this study a cell culture of dispersed rat anterior pituitary cells was exposed to single doses of radiation in the range of 100 to 1500 rad. Survival curves were obtained for the different anterior pituitary cell lines, and growth hormone secretion was measured in the tissue culture medium. Both survival and growth hormone secretion curves showed an initial shoulder in the range of 0 to 300 rad, followed by a decline between 300 to 750 rad. It is concluded that growth hormone secreting acidophilic pituicytes are sensitive to radiation at single doses greater than 300 rad

Single-dose and fractionated irradiation of four human lung cancer cell lines in vitro

International Nuclear Information System (INIS)

Brodin, O.; Lennartsson, L.; Nilsson, S.

1991-01-01

Four established human lung cancer cell lines were exposed to single-dose irradiation. The survival curves of 2 small cell lung carcinomas (SCLC) were characterized by a limited capacity for repair with small and moderate shoulders with extrapolation numbers (n) of 1.05 and 1.60 respectively. Two non-small cell lung carcinoma (NSCLC) cell lines, one squamous cell (SQCLC) and one large cell (LCLC) had large shoulders with n-values of 73 and 15 respectively. The radiosensitivity when measured as D 0 did not, however, differ as much from cell line to cell line, with values from 1.22 to 1.65. The surviving fraction after 2 Gy (SF2) was 0.24 and 0.42 respectively in the SCLC cell lines and 0.90 and 0.88 respectively in the NSCLC cell lines. Fractionated irradiation delivered according to 3 different schedules was also investigated. All the schedules delivered a total dose of 10 Gy in 5 days and were applied in 1, 2 and 5 Gy dose fractions respectively. Survival followed the pattern found after single-dose irradiation; it was lowest in the SCLC cell line with the lowest SF and highest in the two NSCLC cell lines. In the SCLC cell lines all schedules were approximately equally efficient. In the LCLC and in the SQCLC cell lines, the 5 Gy schedule killed more cells than the 1 and 2 Gy schedules. The results indicate that the size of the shoulder of the survival curve is essential when choosing the most tumoricidal fractionation schedule. (orig.)

A comparison in young and elderly subjects of the pharmacokinetics and pharmacodynamics of single and multiple doses of benazepril.

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