WorldWideScience

Sample records for extremely low-dose dexamethasone

  1. Analysis of renal impairment in MM-003, a phase III study of pomalidomide + low - dose dexamethasone versus high - dose dexamethasone in refractory or relapsed and refractory multiple myeloma

    Science.gov (United States)

    Weisel, Katja C.; Dimopoulos, Meletios A.; Moreau, Philippe; Lacy, Martha Q.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Banos, Anne; Oriol, Albert; Alegre, Adrian; Chen, Christine; Cavo, Michele; Garderet, Laurent; Ivanova, Valentina; Martinez-Lopez, Joaquin; Knop, Stefan; Yu, Xin; Hong, Kevin; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Miguel, Jesus San

    2016-01-01

    Pomalidomide + low-dose dexamethasone is effective and well tolerated for refractory or relapsed and refractory multiple myeloma after bortezomib and lenalidomide failure. The phase III trial MM-003 compared pomalidomide + low-dose dexamethasone with high-dose dexamethasone. This subanalysis grouped patients by baseline creatinine clearance ≥ 30 − < 60 mL/min (n=93, pomalidomide + low-dose dexamethasone; n=56, high-dose dexamethasone) or ≥ 60 mL/min (n=205, pomalidomide + low-dose dexamethasone; n=93, high-dose dexamethasone). Median progression-free survival was similar for both subgroups and favored pomalidomide + low-dose dexamethasone versus high-dose dexamethasone: 4.0 versus 1.9 months in the group with baseline creatinine clearance ≥ 30 − < 60 mL/min (P<0.001) and 4.0 versus 2.0 months in the group with baseline creatinine clearance ≥ 60 mL/min (P<0.001). Median overall survival for pomalidomide + low-dose dexamethasone versus high-dose dexamethasone was 10.4 versus 4.9 months (P=0.030) and 15.5 versus 9.2 months (P=0.133), respectively. Improved renal function, defined as an increase in creatinine clearance from < 60 to ≥ 60 mL/min, was similar in pomalidomide + low-dose dexamethasone and high-dose dexamethasone patients (42% and 47%, respectively). Improvement in progression-free and overall survival in these patients was comparable with that in patients without renal impairment. There was no increase in discontinuations of therapy, dose modifications, and adverse events in patients with moderate renal impairment. Pomalidomide at a starting dose of 4 mg + low-dose dexamethasone is well tolerated in patients with refractory or relapsed and refractory multiple myeloma, and of comparable efficacy if moderate renal impairment is present. This trial was registered with clinicaltrials.gov identifier 01311687 and EudraCT identifier 2010-019820-30. PMID:27081177

  2. Low-Dose Dexamethasone Therapy from Infancy of Virilizing Congenital Adrenal Hyperplasia

    Directory of Open Access Journals (Sweden)

    Stephenson Kerry

    2009-12-01

    Full Text Available Objective. To assess the growth and control of adrenal androgen secretion in children with virilizing congenital adrenal hyperplasia (CAH treated with dexamethasone. Method. We examined doses used, control of adrenal androgen secretion, and growth and skeletal maturation of 8 children with CAH treated with dexamethasone beginning in infancy. Results. 3 boys and 5 girls with classical CAH (17-hydroxyprogesterone at diagnosis >20,000 ng/dL were treated with dexamethasone beginning at diagnosis ( ; all doses were given in the morning using a dosing syringe to administer a 0.1 mg/mL elixir. The children were treated for years over which time the change in bone age to chronological age ratio (BA/CA was . Most recent height Z' scores were , and body mass index (BMI scores were . Late afternoon levels of 17-hydroxyprogesterone, androstenedione, and testosterone were  ng/dL ( nmol/L,  ng/dL ( nmol/L, and  ng/dL; ( nmol/L, respectively. Conclusions. These observations show that low doses of dexamethasone can be used to effectively treat CAH beginning in infancy.

  3. Impact of prior treatment and depth of response on survival in MM-003, a randomized phase 3 study comparing pomalidomide plus low-dose dexamethasone versus high-dose dexamethasone in relapsed/refractory multiple myeloma

    Science.gov (United States)

    San Miguel, Jesus F.; Weisel, Katja C.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Moreau, Philippe; Banos, Anne; Oriol, Albert; Garderet, Laurent; Cavo, Michele; Ivanova, Valentina; Alegre, Adrian; Martinez-Lopez, Joaquin; Chen, Christine; Renner, Christoph; Bahlis, Nizar Jacques; Yu, Xin; Teasdale, Terri; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Dimopoulos, Meletios A.

    2015-01-01

    Pomalidomide is a distinct oral IMiD® immunomodulatory agent with direct antimyeloma, stromal-support inhibitory, and immunomodulatory effects. The pivotal, multicenter, open-label, randomized phase 3 trial MM-003 compared pomalidomide + low-dose dexamethasone vs high-dose dexamethasone in 455 patients with refractory or relapsed and refractory multiple myeloma after failure of bortezomib and lenalidomide treatment. Initial results demonstrated significantly longer progression-free survival and overall survival with an acceptable tolerability profile for pomalidomide + low-dose dexamethasone vs high-dose dexamethasone. This secondary analysis describes patient outcomes by treatment history and depth of response. Pomalidomide + low-dose dexamethasone significantly prolonged progression-free survival and favored overall survival vs high-dose dexamethasone for all subgroups analyzed, regardless of prior treatments or refractory status. Both univariate and multivariate analyses showed that no variable relating to either the number (≤ or > 3) or type of prior treatment was a significant predictor of progression-free survival or overall survival. No cross-resistance with prior lenalidomide or thalidomide treatment was observed. Patients achieving a minimal response or better to pomalidomide + low-dose dexamethasone treatment experienced a survival benefit, which was even higher in those achieving at least a partial response (17.2 and 19.9 months, respectively, as compared with 7.5 months for patients with less than minimal response). These data suggest that pomalidomide + low-dose dexamethasone should be considered a standard of care in patients with refractory or relapsed and refractory multiple myeloma regardless of prior treatment. ClinicalTrials.gov: NCT01311687; EudraCT: 2010-019820-30. PMID:26160879

  4. A Retrospective Study Evaluating the Effect of Low Doses of Perineural Dexamethasone on Ropivacaine Brachial Plexus Peripheral Nerve Block Analgesic Duration.

    Science.gov (United States)

    Schnepper, Gregory D; Kightlinger, Benjamin I; Jiang, Yunyun; Wolf, Bethany J; Bolin, Eric D; Wilson, Sylvia H

    2017-09-23

    Examination of the effectiveness of perineural dexamethasone administered in very low and low doses on ropivacaine brachial plexus block duration. Retrospective evaluation of brachial plexus block duration in a large cohort of patients receiving peripheral nerve blocks with and without perineural dexamethasone in a prospectively collected quality assurance database. A single academic medical center. A total of 1,942 brachial plexus blocks placed over a 16-month period were reviewed. Demographics, nerve block location, and perineural dexamethasone utilization and dose were examined in relation to block duration. Perineural dexamethasone was examined as none (0 mg), very low dose (2 mg or less), and low dose (greater than 2 mg to 4 mg). Continuous catheter techniques, local anesthetics other than ropivacaine, and block locations with fewer than 15 subjects were excluded. Associations between block duration and predictors of interest were examined using multivariable regression models. A subgroup analysis of the impact of receiving dexamethasone on block duration within each block type was also conducted using a univariate linear regression approach. A total of 1,027 subjects were evaluated. More than 90% of brachial plexus blocks contained perineural dexamethasone (≤4 mg), with a median dose of 2 mg. Increased block duration was associated with receiving any dose of perineural dexamethasone (P block duration did not differ with very low- or low-dose perineural dexamethasone after controlling for other factors (P = 0.420). Perineural dexamethasone prolonged block duration compared with ropivacaine alone; however, duration was not greater with low-dose compared with very low-dose perineural dexamethasone. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  5. Clarithromycin (Biaxin)-lenalidomide-low-dose dexamethasone (BiRd) versus lenalidomide-low-dose dexamethasone (Rd) for newly diagnosed myeloma.

    Science.gov (United States)

    Gay, Francesca; Rajkumar, S Vincent; Coleman, Morton; Kumar, Shaji; Mark, Tomer; Dispenzieri, Angela; Pearse, Roger; Gertz, Morie A; Leonard, John; Lacy, Martha Q; Chen-Kiang, Selina; Roy, Vivek; Jayabalan, David S; Lust, John A; Witzig, Thomas E; Fonseca, Rafael; Kyle, Robert A; Greipp, Philip R; Stewart, A Keith; Niesvizky, Ruben

    2010-09-01

    The objective of this case-matched study was to compare the efficacy and toxicity of the addition of clarithromycin (Biaxin) to lenalidomide/low-dose dexamethasone (BiRd) vs. lenalidomide/low-dose dexamethasone (Rd) for newly diagnosed myeloma. Data from 72 patients treated at the New York Presbyterian Hospital-Cornell Medical Center were retrospectively compared with an equal number of matched pair mates selected among patients seen at the Mayo Clinic who received Rd. Case matching was blinded and was performed according to age, gender, and transplant status. On intention-to-treat analysis, complete response (45.8% vs. 13.9%, P < 0.001) and very-good-partial-response or better (73.6% vs. 33.3%, P < 0.001) were significantly higher with BiRd. Time-to-progression (median 48.3 vs. 27.5 months, P = 0.071), and progression-free survival (median 48.3 vs. 27.5 months, P = 0.044) were higher with BiRd. There was a trend toward better OS with BiRd (3-year OS: 89.7% vs. 73.0%, P = 0.170). Main grade 3-4 toxicities of BiRd were hematological, in particular thrombocytopenia (23.6% vs. 8.3%, P = 0.012). Infections (16.7% vs. 9.7%, P = 0.218) and dermatological toxicity (12.5% vs. 4.2%, P = 0.129) were higher with Rd. Results of this case-matched analysis suggest that there is significant additive value when clarithromycin is added to Rd. Randomized phase III trials are needed to confirm these results. © 2010 Wiley-Liss, Inc.

  6. Low-Dose Dexamethasone Therapy from Infancy of Virilizing Congenital Adrenal Hyperplasia

    Directory of Open Access Journals (Sweden)

    Scott A. Rivkees

    2009-01-01

    Full Text Available Objective. To assess the growth and control of adrenal androgen secretion in children with virilizing congenital adrenal hyperplasia (CAH treated with dexamethasone. Method. We examined doses used, control of adrenal androgen secretion, and growth and skeletal maturation of 8 children with CAH treated with dexamethasone beginning in infancy. Results. 3 boys and 5 girls with classical CAH (17-hydroxyprogesterone at diagnosis >20,000 ng/dL were treated with dexamethasone beginning at diagnosis (<10 days of age. Patients were also treated with fludrocortisone and sodium chloride. The average initial medication dose was 0.1 mg (0.28±0.015 mg/m2; all doses were given in the morning using a dosing syringe to administer a 0.1 mg/mL elixir. The children were treated for 6.5±2.0 years over which time the change in bone age to chronological age ratio (ΔBA/ΔCA was 0.9±0.06. Most recent height Z' scores were +0.5±0.2, and body mass index (BMI scores were 18±0.2. Late afternoon levels of 17-hydroxyprogesterone, androstenedione, and testosterone were 780±238 ng/dL (23.4±7 nmol/L, 42±10 ng/dL (1.4±0.3 nmol/L, and 11.5±3 ng/dL; (0.4±0.1 nmol/L, respectively. Conclusions. These observations show that low doses of dexamethasone can be used to effectively treat CAH beginning in infancy.

  7. The effect of single low-dose dexamethasone on vomiting during awake craniotomy.

    Science.gov (United States)

    Kamata, Kotoe; Morioka, Nobutada; Maruyama, Takashi; Komayama, Noriaki; Nitta, Masayuki; Muragaki, Yoshihiro; Kawamata, Takakazu; Ozaki, Makoto

    2016-12-01

    Intraoperative vomiting leads to serious respiratory complications that could influence the surgical decision-making process for awake craniotomy. However, the use of antiemetics is still limited in Japan. The aim of this study was to investigate the effect of prophylactically administered single low-dose dexamethasone on the incidence of vomiting during awake craniotomy. The frequency of hyperglycemia was also examined. We conducted a retrospective case review of awake craniotomy for glioma resection between 2012 and 2015. Of the 124 patients, 91 were included in the analysis. Dexamethasone was not used in 43 patients and the 48 remaining patients received an intravenous bolus of 4.95 mg dexamethasone at anesthetic induction. Because of stable operating conditions, no one required conscious sedation throughout functional mapping and tumor resection. Although dexamethasone pretreatment reduced the incidence of intraoperative vomiting (P = 0.027), the number of patients who complained of nausea was comparable (P = 0.969). No adverse events related to vomiting occurred intraoperatively. Baseline blood glucose concentration did not differ between each group (P = 0.143), but the samples withdrawn before emergence (P = 0.018), during the awake period (P awake craniotomy cases. However, as even a small dose of dexamethasone increases the risk for hyperglycemia, antiemetic prophylaxis with dexamethasone should be administered after careful consideration. Monitoring of perioperative blood glucose concentration is also necessary.

  8. Adverse event management in patients with relapsed and refractory multiple myeloma taking pomalidomide plus low-dose dexamethasone: A pooled analysis.

    Science.gov (United States)

    Moreau, Philippe; Dimopoulos, Meletios A; Richardson, Paul G; Siegel, David S; Cavo, Michele; Corradini, Paolo; Weisel, Katja; Delforge, Michel; O'Gorman, Peter; Song, Kevin; Chen, Christine; Bahlis, Nizar; Oriol, Albert; Hansson, Markus; Kaiser, Martin; Anttila, Pekka; Raymakers, Reinier; Joao, Cristina; Cook, Gordon; Sternas, Lars; Biyukov, Tsvetan; Slaughter, Ana; Hong, Kevin; Herring, Jennifer; Yu, Xin; Zaki, Mohamed; San-Miguel, Jesus

    2017-09-01

    Heavily pretreated patients with relapsed and refractory multiple myeloma are susceptible to treatment-related adverse events (AEs). Managing AEs are important to ensure patients continue therapy long enough to receive the best clinical benefit. Data from the MM-002, MM-003, and MM-010 trials were pooled to further characterize the safety profile of pomalidomide plus low-dose dexamethasone and AE management. This analysis included 1088 patients who received ≥ 2 prior therapies, including lenalidomide and bortezomib, and progressed ≤ 60 days of last therapy. Patients received 28-day cycles of pomalidomide 4 mg/day on days 1-21 and low-dose dexamethasone 40 mg (20 mg if aged > 75 years) weekly until disease progression or unacceptable toxicity. Thromboprophylaxis was required. The most common grade 3/4 AEs were neutropenia (56.2%), anemia (32.3%), and thrombocytopenia (25.8%), which occurred within the first few cycles of treatment. Grade 3/4 infections occurred in 33.7% patients, of whom 13.9% had pneumonia, and 40.3% had neutropenia. Pomalidomide dose reductions or interruptions were reported in 24.2% and 66.0% of patients, respectively. AEs were managed by dose modifications and/or supportive care. Pomalidomide plus low-dose dexamethasone showed an acceptable safety profile, and AEs were well managed according to study protocols and established guidelines. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. The effect of single low-dose dexamethasone on blood glucose concentrations in the perioperative period: a randomized, placebo-controlled investigation in gynecologic surgical patients.

    Science.gov (United States)

    Murphy, Glenn S; Szokol, Joseph W; Avram, Michael J; Greenberg, Steven B; Shear, Torin; Vender, Jeffery S; Gray, Jayla; Landry, Elizabeth

    2014-06-01

    The effect of single low-dose dexamethasone therapy on perioperative blood glucose concentrations has not been well characterized. In this investigation, we examined the effect of 2 commonly used doses of dexamethasone (4 and 8 mg at induction of anesthesia) on blood glucose concentrations during the first 24 hours after administration. Two hundred women patients were randomized to 1 of 6 groups: Early-control (saline); Early-4 mg (4 mg dexamethasone); Early-8 mg (8 mg dexamethasone); Late-control (saline); Late-4 mg (4 mg dexamethasone); and Late-8 mg (8 mg dexamethasone). Blood glucose concentrations were measured at baseline and 1, 2, 3, and 4 hours after administration in the early groups and at baseline and 8 and 24 hours after administration in the late groups. The incidence of hyperglycemic events (the number of patients with at least 1 blood glucose concentration >180 mg/dL) was determined. Blood glucose concentrations increased significantly over time in all control and dexamethasone groups (from median baselines of 94 to 102 mg/dL to maximum medians ranging from 141 to 161.5 mg/dL, all P < 0.001). Blood glucose concentrations did not differ significantly between the groups receiving dexamethasone (either 4 or 8 mg) and those receiving saline at any measurement time. The incidence of hyperglycemic events did not differ in any of the early (21%-28%, P = 0.807) or late (13%-24%, P = 0.552) groups. Because blood glucose concentrations during the first 24 hours after administration of single low-dose dexamethasone did not differ from those observed after saline administrations, these results suggest clinicians need not avoid using dexamethasone for nausea and vomiting prophylaxis out of concerns related to hyperglycemia.

  10. ATM splicing variants as biomarkers for low dose dexamethasone treatment of A-T.

    Science.gov (United States)

    Menotta, Michele; Biagiotti, Sara; Spapperi, Chiara; Orazi, Sara; Rossi, Luigia; Chessa, Luciana; Leuzzi, Vincenzo; D'Agnano, Daniela; Soresina, Annarosa; Micheli, Roberto; Magnani, Mauro

    2017-07-05

    Ataxia Telangiectasia (AT) is a rare incurable genetic disease, caused by biallelic mutations in the Ataxia Telangiectasia-Mutated (ATM) gene. Treatment with glucocorticoid analogues has been shown to improve the neurological symptoms that characterize this syndrome. Nevertheless, the molecular mechanism underlying the glucocorticoid action in AT patients is not yet understood. Recently, we have demonstrated that Dexamethasone treatment may partly restore ATM activity in AT lymphoblastoid cells by a new ATM transcript, namely ATMdexa1. In the present study, the new ATMdexa1 transcript was also identified in vivo, specifically in the PMBCs of AT patients treated with intra-erythrocyte Dexamethasone (EryDex). In these patients it was also possible to isolate new "ATMdexa1 variants" originating from canonical and non-canonical splicing, each containing the coding sequence for the ATM kinase domain. The expression of the ATMdexa1 transcript family was directly related to treatment and higher expression levels of the transcript in patients' blood correlated with a positive response to Dexamethasone therapy. Neither untreated AT patients nor untreated healthy volunteers possessed detectable levels of the transcripts. ATMdexa1 transcript expression was found to be elevated 8 days after the drug infusion, while it decreased 21 days after treatment. For the first time, the expression of ATM splicing variants, similar to those previously observed in vitro, has been found in the PBMCs of patients treated with EryDex. These findings show a correlation between the expression of ATMdexa1 transcripts and the clinical response to low dose dexamethasone administration.

  11. Oval pulsed high-dose dexamethasone for myositis

    NARCIS (Netherlands)

    Hoogendijk, JE; Wokke, JHJ; de Visser, M

    To study the short-term effect of oral pulsed high-dose dexamethasone for myositis we treated eight newly diagnosed patients with three 28-day cycles of oral dexamethasone. Primary outcome measures were muscle strength, pain, and serum creatine kinase activity. Sis patients responded. Side effects

  12. Oral pulsed high-dose dexamethasone for myositis

    NARCIS (Netherlands)

    van der Meulen, M. F.; Hoogendijk, J. E.; Wokke, J. H.; de Visser, M.

    2000-01-01

    To study the short-term effect of oral pulsed high-dose dexamethasone for myositis we treated eight newly diagnosed patients with three 28-day cycles of oral dexamethasone. Primary outcome measures were muscle strength, pain, and serum creatine kinase activity. Six patients responded. Side effects

  13. 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.

  14. Comparative Efficacy of Daratumumab Monotherapy and Pomalidomide Plus Low-Dose Dexamethasone in the Treatment of Multiple Myeloma: A Matching Adjusted Indirect Comparison.

    Science.gov (United States)

    Van Sanden, Suzy; Ito, Tetsuro; Diels, Joris; Vogel, Martin; Belch, Andrew; Oriol, Albert

    2018-03-01

    Daratumumab (a human CD38-directed monoclonal antibody) and pomalidomide (an immunomodulatory drug) plus dexamethasone are both relatively new treatment options for patients with heavily pretreated multiple myeloma. A matching adjusted indirect comparison (MAIC) was used to compare absolute treatment effects of daratumumab versus pomalidomide + low-dose dexamethasone (LoDex; 40 mg) on overall survival (OS), while adjusting for differences between the trial populations. The MAIC method reduces the risk of bias associated with naïve indirect comparisons. Data from 148 patients receiving daratumumab (16 mg/kg), pooled from the GEN501 and SIRIUS studies, were compared separately with data from patients receiving pomalidomide + LoDex in the MM-003 and STRATUS studies. The MAIC-adjusted hazard ratio (HR) for OS of daratumumab versus pomalidomide + LoDex was 0.56 (95% confidence interval [CI], 0.38-0.83; p  = .0041) for MM-003 and 0.51 (95% CI, 0.37-0.69; p  < .0001) for STRATUS. The treatment benefit was even more pronounced when the daratumumab population was restricted to pomalidomide-naïve patients (MM-003: HR, 0.33; 95% CI, 0.17-0.66; p  = .0017; STRATUS: HR, 0.41; 95% CI, 0.21-0.79; p  = .0082). An additional analysis indicated a consistent trend of the OS benefit across subgroups based on M-protein level reduction (≥50%, ≥25%, and <25%). The MAIC results suggest that daratumumab improves OS compared with pomalidomide + LoDex in patients with heavily pretreated multiple myeloma. This matching adjusted indirect comparison of clinical trial data from four studies analyzes the survival outcomes of patients with heavily pretreated, relapsed/refractory multiple myeloma who received either daratumumab monotherapy or pomalidomide plus low-dose dexamethasone. Using this method, daratumumab conferred a significant overall survival benefit compared with pomalidomide plus low-dose dexamethasone. In the absence of head-to-head trials, these

  15. Extended low-dose dexamethasone suppression test for diagnosis of atypical Cushing's syndrome in dogs.

    Science.gov (United States)

    Fowler, K M; Frank, L A; Morandi, F; Whittemore, J C

    2017-07-01

    The purpose of this study was to evaluate extension of the low-dose dexamethasone suppression (LDDS) test from 8 h to 12 h to detect possible hypercortisolemia associated with atypical hyperadrenocorticism (AHAC). Twelve client-owned dogs were enrolled in the study: 6 healthy dogs (group 1) and 6 dogs with suspected AHAC (group 2). Baseline EDTA plasma samples were collected for endogenous ACTH determination using an immunoradiometric assay. Serum samples were collected before and at 4, 8, 10, and 12 h post-administration of 0.01 mg/kg dexamethasone IV for cortisol concentration determination via chemiluminescent assay. Mean endogenous ACTH concentration did not differ between groups (group 1: 22.4 pg/mL, group 2: 20.0 pg/mL; P > 0.2). Mean baseline cortisol concentration also did not differ significantly between groups (group 1: 3.03 μg/dL, group 2: 4.95 μg/dL; P > 0.2) nor was there any difference in mean cortisol concentration between the groups at any other time point (P > 0.2). The cortisol concentration from 1 dog in group 2 suppressed to 0.7 μg/dL at 8 h but increased to 1.5 μg/dL at 10 h and 3.7 μg/dL at 12 h post-dexamethasone. Based on results of this study, use of an extended LDDS test could not differentiate between healthy dogs and dogs with AHAC. Diagnosis of AHAC should continue to be based on prior established criteria until new testing has been identified. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Anti-CD163-dexamethasone conjugate inhibits the acute phase response to lipopolysaccharide in rats

    DEFF Research Database (Denmark)

    Thomsen, Karen Louise; Møller, Holger Jon; Graversen, Jonas Heilskov

    2016-01-01

    ± 4036 pg/mL, P = 0.03) compared to the low dose dexamethasone. The high dose dexamethasone dose decreased the spleen weight (421 ± 11 mg vs 465 ± 12 mg, P any other group. CONCLUSION: Low-dose anti-CD163-dexamethasone conjugate effectively decreased...

  17. Low-dose dexamethasone during arthroplasty: What do we know about the risks?

    NARCIS (Netherlands)

    Wegener, Jessica T.; Kraal, Tim; Stevens, Markus F.; Hollmann, Markus W.; Kerkhoffs, Gino M. M. J.; Haverkamp, Daniël

    2016-01-01

    Dexamethasone is commonly applied during arthroplasty to control post-operative nausea and vomiting (PONV). However, conflicting views of orthopaedic surgeons and anaesthesiologists regarding the use of dexamethasone raise questions about risks of impaired wound healing and surgical site infections

  18. Prophylactic low-dose aspirin is effective antithrombotic therapy for combination treatments of thalidomide or lenalidomide in myeloma.

    Science.gov (United States)

    Niesvizky, Ruben; Martínez-Baños, Déborah; Jalbrzikowski, Jessica; Christos, Paul; Furst, Jessica; De Sancho, Maria; Mark, Tomer; Pearse, Roger; Mazumdar, Madhu; Zafar, Faiza; Pekle, Karen; Leonard, John; Jayabalan, David; Coleman, Morton

    2007-12-01

    Multiple myeloma (MM) patients have a propensity for thromboembolic events (TE), and treatment with thalidomide/dexamethasone or lenalidomide/dexamethasone increases this risk. This report describes the use of low-dose aspirin (81 mg) as primary thromboprophylaxis in three series of MM patients receiving thalidomide or lenalidomide with other drugs. In the first regimen (clarithromycin, thalidomide, dexamethasone), initiation of low-dose aspirin negated the occurrence of any further TE. In a second study, prophylactic aspirin given with thalidomide/dexamethasone resulted in a rate of TE similar to that seen with dexamethasone alone (without aspirin). A third study (n = 72) evaluated thrombosis rates with aspirin and a lenalidomide-containing regimen (clarithromycin, lenalidomide, dexamethasone). Of nine occurrences of thromboembolism, five were associated with aspirin interruption or poor compliance. Low-dose aspirin appears to reduce the incidence of thrombosis with these regimens. Routine use of aspirin as antithrombotic prophylaxis in MM patients receiving immunomodulatory drugs with corticosteroids is warranted.

  19. Bortezomib or high-dose dexamethasone for relapsed multiple myeloma

    NARCIS (Netherlands)

    P.G. Richardson (Paul Gerard); P. Sonneveld (Pieter); M.W. Schuster (Michael); D. Irwin (David); E.A. Stadtmauer (Edward); T. Facon (Thierry); J-L. Harousseau (Jean-Luc); D. Ben-Yehuda (Dina); S. Lonial (Sagar); H. Goldschmidt (Hartmut); D. Reece (Donna); J.F. San Miguel (Jesús Fernando); J. Bladé (Joan); M. Boccadoro (Mario); J. Cavenagh (Jamie); W. Dalton (William); A.L. Boral (Anthony); D.-L. Esseltine (Dixie-Lee); J.B. Porter (Jane); D. Schenkein (David); K.C. Anderson (Kenneth)

    2005-01-01

    textabstractBACKGROUND: This study compared bortezomib with high-dose dexamethasone in patients with relapsed multiple myeloma who had received one to three previous therapies. METHODS: We randomly assigned 669 patients with relapsed myeloma to receive either an intravenous bolus of bortezomib (1.3

  20. Low submetamorphic doses of dexamethasone and thyroxine induce complete metamorphosis in the axolotl (Ambystoma mexicanum) when injected together.

    Science.gov (United States)

    Kühn, Eduard R; De Groef, Bert; Grommen, Sylvia V H; Van der Geyten, Serge; Darras, Veerle M

    2004-06-01

    Entanglement of functions between the adrenal (or interrenal) and thyroid axis has been well described for all vertebrates and can be tracked down up to the level of gene expression. Both thyroid hormones and corticosteroids may induce morphological changes leading to metamorphosis climax in the neotenic Mexican axolotl (Ambystoma mexicanum). In a first series of experiments, metamorphosis was induced with an injection of 25 microg T(4) on three alternate days as judged by a decrease in body weight and tail height together with complete gill resorption. This injection also resulted in elevated plasma concentrations of T(3) and corticosterone. Previous results have indicated that the same dose of dexamethasone (DEX) is ineffective in this regard (Gen. Comp. Endocrinol. 127 (2002) 157). In a second series of experiments low doses of T(4) (0.5 microg) or DEX (5 microg) were ineffective to induce morphological changes. However, when these submetamorphic doses were injected together, morphological changes were observed within one week leading to complete metamorphosis. It is concluded that thyroid hormones combined with corticosteroids are essential for metamorphosis in the axolotl and that only high doses of either thyroid hormone or corticosteroid can induce morphological changes when injected separately.

  1. Fatal Gastrointestinal Hemorrhage in a Young Boy with Newly Diagnosed Metastatic Medulloblastoma on High Dose Dexamethasone

    Directory of Open Access Journals (Sweden)

    Victor Wong

    2014-01-01

    Full Text Available A 10-year-old boy with newly diagnosed metastatic medulloblastoma was placed on high dose dexamethasone and ranitidine prior to surgery. The child underwent subtotal resection and was discharged 5 days postoperatively with an uneventful hospital course on a tapering dose of dexamethasone and ranitidine. Over the next 2 days the patient complained of mild abdominal distension with flatulence, without pain, vomiting, or dysmotility. On follow-up in clinic 5 days after discharge, he had normal vital signs when he suddenly became pale and had loss of consciousness. Emergent computerized tomography of the head showed no acute hemorrhage and complete blood count revealed hemoglobin of 4.2 gm/dL. In spite of maximum resuscitation with copious blood products the patient died. Autopsy revealed evidence of duodenal perforation with intraluminal hemorrhage. This case demonstrates a rare fatal complication of high dose dexamethasone therapy even with concurrent gastrointestinal prophylactic therapy. We provide a review of the limited literature on steroid use in pediatric neurooncology with regard to gastrointestinal bleeding.

  2. Anti-CD163-dexamethasone protects against apoptosis after ischemia/reperfusion injuries in the rat liver

    DEFF Research Database (Denmark)

    Møller, Lin Nanna Okholm; Knudsen, Anders Riegels; Andersen, Kasper Jarlhelt

    2015-01-01

    , high dose dexamethasone, low dose dexamethasone or placebo intravenously 18 h before laparotomy with subsequent 60 min of liver ischemia. After reperfusion for 24 h the animals had their liver removed. Bloods were drawn 30 min and 24 h post ischemia induction. Liver cell apoptosis and necrosis were...

  3. Dexamethasone hepatic induction in rats subsequently treated with high dose buprenorphine does not lead to respiratory depression

    International Nuclear Information System (INIS)

    Hreiche, Raymond; Megarbane, Bruno; Pirnay, Stephane; Borron, Stephen W.; Monier, Claire; Risede, Patricia; Milan, Nathalie; Descatoire, Veronique; Pessayre, Dominique; Baud, Frederic J.

    2006-01-01

    In humans, asphyxic deaths and severe poisonings have been attributed to high-dosage buprenorphine, a maintenance therapy for heroin addiction. However, in rats, intravenous buprenorphine at doses up to 90 mg kg -1 was not associated with significant effects on arterial blood gases. In contrast, norbuprenorphine, the buprenorphine major cytochrome P450 (CYP) 3A-derived metabolite, is a potent respiratory depressant. Thus, our aim was to study the consequences of CYP3A induction on buprenorphine-associated effects on resting ventilation in rats. We investigated the effects on ventilation of 30 mg kg -1 buprenorphine alone or following cytochrome P450 (CYP) 3A induction with dexamethasone, using whole body plethysmography (N = 24) and arterial blood gases (N = 12). Randomized animals in 4 groups received sequential intraperitoneal dosing with: (dexamethasone [days 1-3] + buprenorphine [day 4]), (dexamethasone solvent [days 1-3] + buprenorphine [day 4]), (dexamethasone [days 1-3] + buprenorphine solvent [day 4]), or (dexamethasone solvent [days 1-3] + buprenorphine solvent [day 4]). Buprenorphine alone caused a significant rapid and sustained increase in the inspiratory time (P -1 buprenorphine on rat ventilation. Our results suggest a limited role of drug-mediated CYP3A induction in the occurrence of buprenorphine-attributed respiratory depression in addicts

  4. Sustained intra-cartilage delivery of low dose dexamethasone using a cationic carrier for treatment of post traumatic osteoarthritis

    Directory of Open Access Journals (Sweden)

    AG Bajpayee

    2017-12-01

    Full Text Available Disease-modifying osteoarthritis drugs (DMOADs should reach their intra-tissue target sites at optimal doses for clinical efficacy. The dense, negatively charged matrix of cartilage poses a major hindrance to the transport of potential therapeutics. In this work, electrostatic interactions were utilised to overcome this challenge and enable higher uptake, full-thickness penetration and enhanced retention of dexamethasone (Dex inside rabbit cartilage. This was accomplished by using the positively charged glycoprotein avidin as nanocarrier, conjugated to Dex by releasable linkers. Therapeutic effects of a single intra-articular injection of low dose avidin-Dex (0.5 mg Dex were evaluated in rabbits 3 weeks after anterior cruciate ligament transection (ACLT. Immunostaining confirmed that avidin penetrated the full cartilage thickness and was retained for at least 3 weeks. Avidin-Dex suppressed injury-induced joint swelling and catabolic gene expression to a greater extent than free Dex. It also significantly improved the histological score of cell infiltration and morphogenesis within the periarticular synovium. Micro-computed tomography confirmed the reduced incidence and volume of osteophytes following avidin-Dex treatment. However, neither treatment restored the loss of cartilage stiffness following ACLT, suggesting the need for a combinational therapy with a pro-anabolic factor for enhancing matrix biosynthesis. The avidin dose used caused significant glycosaminoglycan (GAG loss, suggesting the use of higher Dex : avidin ratios in future formulations, such that the delivered avidin dose could be much less than that shown to affect GAGs. This charge-based delivery system converted cartilage into a drug depot that could also be employed for delivery to nearby synovium, menisci and ligaments, enabling clinical translation of a variety of DMOADs.

  5. Early corticosteroid treatment does not affect severity of unconjugated hyperbilirubinemia in extreme low birth weight preterm infants

    NARCIS (Netherlands)

    Hulzebos, Christian V.; Bos, Arend F.; Anttila, Eija; Hallman, Mikko; Verkade, Henkjan J.

    Aim: To determine the relationship between early postnatal dexamethasone (DXM) treatment and the severity of hyperbilirubinemia in extreme low birth weight (ELBW) preterm infants. Methods: In 54 ELBW preterm infants, total serum bilirubin concentrations (TSB) and phototherapy (PT) data during the

  6. A Randomized Cross‐over Study of High‐dose Metoclopramide plus Dexamethasone versus Granisetron plus Dexamethasone in Patients Receiving Chemotherapy with High‐dose Cisplatin

    Science.gov (United States)

    Eguchi, Kenji; Shinkai, Tetsu; Tamura, Tomohide; Ohe, Yuichiro; Nisio, Masato; Kunikane, Hiroshi; Arioka, Hitoshi; Karato, Atsuya; Nakashima, Hajime; Sasaki, Yasutsuna; Tajima, Kinuko; Tada, Noriko; Saijo, Nagahiro

    1994-01-01

    We carried out a randomized, single‐blind, cross‐over trial to compare the antiemetic effect, for both acute and delayed emesis, of granisetron plus dexamethasone (GRN+Dx) with that of high‐dose metoclopramide plus dexamethasone (HDMP + Dx). Fifty‐four patients with primary or metastatic lung cancer, given single‐dose cisplatin (> 80 mg/m2) chemotherapy more than twice, were enrolled in this study. They were treated with both HDMP+Dx and GRN+Dx in two consecutive chemotherapy courses. On day 1, patients experienced a mean of 2.5 (SD=4.3) and 0,1 (SD = 0.4) episodes of vomiting in the HDMP+Dx and the GRN + Dx groups, respectively (P=0.0008). Complete response rate on day 1 was 45 and 90% in the HDMP+Dx and the GRN+Dx groups, respectively (P= 0.0001). Patients treated with GRN+Dx had a tendency to suffer more episodes of vomiting than the HDMP+Dx group on days 2–5, but it was not statistically significant. Twenty‐four patients (57%) preferred the GRN+Dx treatment and 14 patients (33%), HDMP + Dx. In the HDMP + Dx group, nine patients (21%) had an extrapyramidal reaction, and 5 patients (12%) had constipation that lasted for at least two days. In contrast, no patients had extrapyramidal reactions, and IS patients (43%) had constipation in the GRN+Dx group (P < 0.01). GRN+Dx was more effective than HDMP+Dx only in preventing the acute emesis induced by cisplatin. An effective treatment for delayed emesis is still needed. PMID:7829401

  7. Intra-arterial Ultra-low-Dose CT Angiography of Lower Extremity in Diabetic Patients

    Energy Technology Data Exchange (ETDEWEB)

    Özgen, Ali, E-mail: draliozgen@hotmail.com [Yeditepe University Hospital, Department of Radiology (Turkey); Sanioğlu, Soner [Yeditepe University Hospital, Department of Cardiovascular Surgery (Turkey); Bingöl, Uğur Anıl [Yeditepe University Hospital, Department of Plastic Surgery (Turkey)

    2016-08-15

    PurposeTo image lower extremity arteries by CT angiography using a very low-dose intra-arterial contrast medium in patients with high risk of developing contrast-induced nephropathy (CIN).Materials and MethodsThree cases with long-standing diabetes mellitus and signs of lower extremity atherosclerotic disease were evaluated by CT angiography using 0.1 ml/kg of the body weight of contrast medium given via 10-cm-long 4F introducer by puncturing the CFA. Images were evaluated by an interventional radiologist and a cardiovascular surgeon. Density values of the lower extremity arteries were also calculated. Findings in two cases were compared with digital subtraction angiography images performed for percutaneous revascularization. Blood creatinine levels were followed for possible CIN.ResultsIntra-arterial CT angiography images were considered diagnostic in all patients and optimal in one patient. No patient developed CIN after intra-arterial CT angiography, while one patient developed CIN after percutaneous intervention.ConclusionIntra-arterial CT angiography of lower extremity might be performed in selected patients with high risk of developing CIN. Our limited experience suggests that as low as of 0.1 ml/kg of the body weight of contrast medium may result in adequate diagnostic imaging.

  8. The effect of intraoperative administration of dexamethasone for PONV prophylaxis on perioperative blood glucose level in obese and normal weight children.

    Science.gov (United States)

    Gnatzy, Richard; Hempel, Gunther; Kaisers, Udo X; Höhne, Claudia

    2015-11-01

    The incidence of postoperative nausea and vomiting (PONV) can be reduced by dexamethasone. Single-dose administration may cause elevated blood glucose levels in obese adults. No data are available for children. The aim was to evaluate perioperative blood glucose changes related to body weight in children who received dexamethasone. This prospective observational study included 62 children. All patients received total intravenous anesthesia and a single dose of dexamethasone (0.15 mg/kg, maximum 8 mg). Blood glucose levels were measured up to 6 h. Standard deviation scores (SDS) were calculated using age- and gender-specific body mass index (BMI) percentiles, pBlood glucose levels increased from 5.52±0.52 to 6.74±0.84 mmol/L 6 h after dexamethasone without correlation to the BMI-SDS. This study showed an increase of perioperative blood glucose (normoglycemic ranges) after single dose of dexamethasone, but no BMI-dependent effect was observed in children. Therefore, low-dose dexamethasone may be used in obese children for PONV prophylaxis.

  9. Typhi–Induced Septic Shock and Acute Respiratory Distress Syndrome in a Previously Healthy Teenage Patient Treated With High-Dose Dexamethasone

    Directory of Open Access Journals (Sweden)

    Melissa Brosset Ugas MD

    2016-05-01

    Full Text Available Typhoid fever is commonly characterized by fever and abdominal pain. Rare complications include intestinal hemorrhage, bowel perforation, delirium, obtundation, and septic shock. Herein we describe the case of a previously healthy 16-year-old male without history of travel, diagnosed with typhoid fever complicated by septic shock and acute respiratory distress syndrome treated with high-dose dexamethasone. This case details severe complications of typhoid fever that are uncommonly seen in developed countries, and the successful response to high-dose dexamethasone as adjunct therapy. High-dose dexamethasone treatment has reportedly decreased Salmonella Typhi mortality, but controlled studies specifically performed in children are lacking, and most reports of its use are over 30 years old and all have originated in developing countries. Providers should include Salmonella Typhi in the differential diagnosis of the pediatric patient with fever, severe abdominal pain, and enteritis, and be aware of its potentially severe complications and the limited data on safety and efficacy of adjunctive therapies that can be considered in addition to antibiotics.

  10. Dexamethasone for pain after outpatient shoulder surgery

    DEFF Research Database (Denmark)

    Bjørnholdt, K. T.; Mønsted, P. N.; Søballe, Kjeld

    2014-01-01

    Background Dexamethasone has analgesic properties when given intravenously before surgery, but the optimal dose has not been determined. We hypothesised that a dose of 40 mg dexamethasone would improve analgesia after outpatient shoulder surgery compared with 8 mg. Methods A randomised, double...... a dose–response relationship, increasing the dexamethasone dose from 8 to 40 mg did not improve analgesia significantly after outpatient shoulder surgery.......) or placebo (D0) before surgery. The primary outcome was pain intensity 8 h after surgery rated on a numeric rating scale of 0 to 10. Secondary outcomes were pain intensity, analgesic consumption and side effects during the first 3 days after surgery. Results Data from 73 patients were available for analysis...

  11. [Value of desmopressin stimulation test and high dose dexamethasone suppression testin the etiologic diagnosis of ACTH dependent Cushing's syndrome].

    Science.gov (United States)

    Zhang, Weiwei; Yu, Yerong; Tan, Huiwen; Wang, Chun; Li, Jianwei; An, Zhenmei; Liu, Yuping

    2016-03-22

    To investigate the value of desmopressin (DDAVP) stimulation test and high dose dexamethasone suppression test (HDDST) in establishing the cause of ACTH dependent Cushing's syndrome. The clinical data of patients with ACTH dependent Cushing's syndrome at West China Hospital from January 1, 2010 to September 30, 2015 was analyzed. The sensitivity and specificity of DDAVP stimulation test, HDDST, and the diagnostic accordance rate when the two tests were combined, were evaluated based on the diagnostic gold standard. A total of 85 patients with Cushing's disease and 10 patients with ectopic ACTH syndrome were included. The sensitivity and specificity of DDAVP stimulation test were 87% and 5/5, respectively, whereas those of HDDST were 79% and 8/10, respectively. The standard high dose dexamethasone suppression test showed a higher sensitivity than overnight 8 mg dexamethasone suppression test. When the two tests had consistent results, the diagnostic accordance rate was 100%. DDAVP stimulation test and HDDST are both efficient modalities for the diagnosis of Cushing's Disease and ectopic ACTH syndrome. The accuracy of diagnosis can be further improved by combining the two tests.

  12. Diurnal Cortisol Patterns and Dexamethasone Suppression Test Responses in Healthy Young Adults Born Preterm at Very Low Birth Weight.

    Directory of Open Access Journals (Sweden)

    Nina Kaseva

    Full Text Available Early life stress, such as painful and stressful procedures during neonatal intensive care after preterm birth, can permanently affect physiological, hormonal and neurobiological systems. This may contribute to altered programming of the hypothalamic-pituitary-adrenal axis (HPAA and provoke changes in HPAA function with long-term health impacts. Previous studies suggest a lower HPAA response to stress in young adults born preterm compared with controls born at term. We assessed whether these differences in HPAA stress responsiveness are reflected in everyday life HPAA functioning, i.e. in diurnal salivary cortisol patterns, and reactivity to a low-dose dexamethasone suppression test (DST, in unimpaired young adults born preterm at very low birth weight (VLBW; <1500 g.The participants were recruited from the Helsinki Study of Very Low Birth Weight Adults cohort study. At mean age 23.3 years (2.1 SD, 49 VLBW and 36 controls born at term participated in the study. For cortisol analyzes, saliva samples were collected on two consecutive days at 0, 15, 30 and 60 min after wake-up, at 12:00 h, 17:00 h and 22:00 h. After the last salivary sample of the first study day the participants were instructed to take a 0.5 mg dexamethasone tablet.With mixed-effects model no difference was seen in overall diurnal salivary cortisol between VLBW and control groups [13.9% (95% CI: -11.6, 47.0, P = 0.31]. Salivary cortisol increased similarly after awakening in both VLBW and control participants [mean difference -2.9% (29.2, 33.0, P = 0.85]. Also reactivity to the low-dose DST (awakening cortisol ratio day2/day1 was similar between VLBW and control groups [-1.1% (-53.5, 103.8, P = 0.97].Diurnal cortisol patterns and reactivity to a low-dose DST in young adulthood were not associated with preterm birth.

  13. Effect of high-dose dexamethasone on the outcome of acute encephalitis due to Japanese encephalitis virus.

    Science.gov (United States)

    Hoke, C H; Vaughn, D W; Nisalak, A; Intralawan, P; Poolsuppasit, S; Jongsawas, V; Titsyakorn, U; Johnson, R T

    1992-04-01

    Death due to Japanese encephalitis usually occurs in the first 5 days of hospitalization as a result of deepening coma with respiratory arrest. Death may result from edema-induced increases in intracranial pressure that might be reduced by the administration of steroids. Sixty-five patients presenting in Thailand to four hospitals with a diagnosis of acute Japanese encephalitis were randomized in a double-masked fashion and stratified by initial mental status into a placebo group (saline) or a treatment group (dexamethasone 0.6 mg/kg intravenously as a loading dose followed by 0.2 mg/kg every 6 h for 5 days). Fifty-five of the 65 had confirmed Japanese encephalitis as demonstrated by detection of virus or by Japanese encephalitis virus-specific IgM antibody. Important outcome measures included mortality (24%, treatment group; 27%, control group), days to alert mental status (3.9 vs. 6.2), and neurologic status 3 months after discharge (45% abnormal in each group). No statistically significant benefit of high-dose dexamethasone could be detected.

  14. Elotuzumab in combination with thalidomide and low-dose dexamethasone: a phase 2 single-arm safety study in patients with relapsed/refractory multiple myeloma.

    Science.gov (United States)

    Mateos, María-Victoria; Granell, Miguel; Oriol, Albert; Martinez-Lopez, Joaquin; Blade, Joan; Hernandez, Miguel T; Martín, Jesus; Gironella, Mercedes; Lynch, Mark; Bleickardt, Eric; Paliwal, Prashni; Singhal, Anil; San-Miguel, Jesus

    2016-11-01

    Elotuzumab is an immunostimulatory, humanized immunoglobulin G1 monoclonal antibody that selectively targets and kills signalling lymphocytic activation molecule family member 7-expressing myeloma cells. We evaluated the safety and tolerability of elotuzumab 10 mg/kg combined with thalidomide 50-200 mg and dexamethasone 40 mg (with/without cyclophosphamide 50 mg) in patients with relapsed/refractory multiple myeloma (RRMM). The primary endpoint was the proportion of grade ≥3 non-haematological adverse events (AEs); other endpoints included the number of dose reductions/discontinuations and efficacy. Forty patients were treated, who had a median of three previous therapies, including bortezomib (98%) and lenalidomide (73%). Grade ≥3 non-haematological AEs were reported in 63% of patients, most commonly asthenia (35%) and peripheral oedema (25%). Six (15%) patients had an infusion reaction. Twenty-six (65%) patients had ≥1 dose reduction/discontinuation due to an AE, none related to elotuzumab. Overall response rate was 38%; median progression-free survival was 3·9 months. Median overall survival was 16·3 months and the 1-year survival rate was 63%. Minimal incremental toxicity was observed with addition of elotuzumab to thalidomide/dexamethasone with or without cyclophosphamide, and efficacy data suggest clinical benefit in a highly pre-treated population. Elotuzumab combined with thalidomide may provide an additional treatment option for patients with RRMM. © 2016 John Wiley & Sons Ltd.

  15. Haloperidol dose combined with dexamethasone for PONV prophylaxis in high-risk patients undergoing gynecological laparoscopic surgery: a prospective, randomized, double-blind, dose-response and placebo-controlled study.

    Science.gov (United States)

    Joo, Jin; Park, Yong Gyu; Baek, Jungwon; Moon, Young Eun

    2015-07-08

    Low-dose haloperidol is known to be effective for the prevention of postoperative nausea and vomiting (PONV). However, precise dose-response studies have not been completed, especially in patients at high risk for PONV who require combination therapy. This study sought to identify which dose of haloperidol 1mg or 2mg could be combined with dexamethasone without adverse effects in high-risk patients undergoing gynecological laparoscopic surgery. Female adults (n = 150) with three established PONV risk factors based on Apfel's score were randomized into one of three study groups. At the end of anesthesia, groups H0, H1, and H2 were given intravenous (IV) saline, haloperidol 1 mg, and haloperidol 2 mg, respectively. All patients were given dexamethasone 5 mg during the induction of anesthesia. The overall early (0-2 h) and late (2-24 h) incidences of nausea, vomiting, rescue anti-emetic administration, pain, and adverse effects (cardiac arrhythmias and extrapyramidal effects) were assessed postoperatively. The sedation score was recorded in the postanesthesia care unit (PACU). The total incidence of PONV over 24 h was significantly lower in groups H1 (29 %) and H2 (24 %) than in group H0 (54 %; P = 0.003), but there was no significant difference between groups H1 and H2. In the PACU, group H2 had a higher sedation score than groups H1 and H0 (P haloperidol was equally effective as 2 mg in terms of preventing PONV with the less sedative effect. ClinicalTrials.gov ( NCT01639599 ).

  16. Effect of dexamethasone in low volume supraclavicular brachial plexus block: A double-blinded randomized clinical study

    Directory of Open Access Journals (Sweden)

    Arun Kumar Alarasan

    2016-01-01

    Full Text Available Background and Aims: With the use of ultrasound, a minimal effective volume of 20 ml has been described for supraclavicular brachial plexus block. However achieving a long duration of analgesia with this minimal volume remains a challenge. We aimed to determine the effect of dexamethasone on onset and duration of analgesia in low volume supraclavicular brachial plexus block. Material and Methods: Sixty patients were randomly divided into two groups of 30 each. Group C received saline (2 ml + 20 ml of 0.5% bupivacaine and Group D received dexamethasone (8 mg + 20 ml of 0.5% bupivacaine in supraclavicular brachial plexus block. Hemodynamic variables and visual analog scale (VAS score were noted at regular intervals until 450 min. The onset and duration of sensory and motor block were measured. The incidence of "Halo" around brachial plexus was observed. Student′s t-test and Chi-square test were used for statistical analysis. Results: The onset of sensory and motor block was significantly earlier in dexamethasone group (10.36 ± 1.99 and 12 ± 1.64 minutes compared to control group (12.9 ± 2.23 and 18.03 ± 2.41 minutes. The duration of sensory and motor block was significantly prolonged in dexamethasone group (366 ± 28.11 and 337.33 ± 28.75 minutes compared to control group (242.66 ± 26.38 and 213 ± 26.80 minutes. The VAS score was significantly lower in dexamethasone group after 210 min. "Halo" was present around the brachial plexus in all patients in both the groups. Conclusion: Dexamethasone addition significantly increases the duration of analgesia in patients receiving low volume supraclavicular brachial plexus block. No significant side-effects were seen in patients receiving dexamethasone as an adjunct.

  17. Evaluation of the release behavior of the dexamethasone embedded in polycarbonate polyurethane membranes: an in vitro study

    International Nuclear Information System (INIS)

    Kim, Dong Hyun; Kang, Sung Gwon; Lee, Chul Gab; Park, Sang Soo; Lee, Don Haeng; Lee, Gyu Baek; Song, Ho Young

    2003-01-01

    To evaluate the release behavior of dexamethasone embedded in a polycarbonate polyurethane membrane. Both water-soluble and water-insoluble dexamethasone were tested, and the release behavior of five water-insoluble dexamethasone films of different thickness (78 to 211 μm) was also evaluated. The amount of dexamethasone used was 10% of the total weight of the polyurethan film mass. Each film was placed in a centrifuge tube containing 25 ml of 0.1-M neutral phosphate buffer, and the tubes were placed in a shaking incubator to quantify the amount of drug released into the buffer, absorption spectroscopy (λ max=242 nm) was employed. In the test involving water-soluble dexamethasone, 60%, of the drug was released during the first two hours of the study. Films containing water-insoluble dexamethasone, on the other hand, released 40%, 60% and 75% of the dexamethasone in one, three and seven days, respectively. Both types of film maintained low-dose drug release for 28 days. When release behavior was compared between water-insoluble films of different thickness, thicker film showed less initial burst and more sustained release. Dexamethasone release behavior varies according to drug solubility and membrane thickness, and may thus be conrolled

  18. Dexamethasone as Adjuvant to Bupivacaine Prolongs the Duration of Thermal Antinociception and Prevents Bupivacaine-Induced Rebound Hyperalgesia via Regional Mechanism in a Mouse Sciatic Nerve Block Model

    Science.gov (United States)

    An, Ke; Elkassabany, Nabil M.; Liu, Jiabin

    2015-01-01

    Background Dexamethasone has been studied as an effective adjuvant to prolong the analgesia duration of local anesthetics in peripheral nerve block. However, the route of action for dexamethasone and its potential neurotoxicity are still unclear. Methods A mouse sciatic nerve block model was used. The sciatic nerve was injected with 60ul of combinations of various medications, including dexamethasone and/or bupivacaine. Neurobehavioral changes were observed for 2 days prior to injection, and then continuously for up to 7 days after injection. In addition, the sciatic nerves were harvested at either 2 days or 7 days after injection. Toluidine blue dyeing and immunohistochemistry test were performed to study the short-term and long-term histopathological changes of the sciatic nerves. There were six study groups: normal saline control, bupivacaine (10mg/kg) only, dexamethasone (0.5mg/kg) only, bupivacaine (10mg/kg) combined with low-dose (0.14mg/kg) dexamethasone, bupivacaine (10mg/kg) combined with high-dose (0.5mg/kg) dexamethasone, and bupivacaine (10mg/kg) combined with intramuscular dexamethasone (0.5mg/kg). Results High-dose perineural dexamethasone, but not systemic dexamethasone, combined with bupivacaine prolonged the duration of both sensory and motor block of mouse sciatic nerve. There was no significant difference on the onset time of the sciatic nerve block. There was “rebound hyperalgesia” to thermal stimulus after the resolution of plain bupivacaine sciatic nerve block. Interestingly, both low and high dose perineural dexamethasone prevented bupivacaine-induced hyperalgesia. There was an early phase of axon degeneration and Schwann cell response as represented by S-100 expression as well as the percentage of demyelinated axon and nucleus in the plain bupivacaine group compared with the bupivacaine plus dexamethasone groups on post-injection day 2, which resolved on post-injection day 7. Furthermore, we demonstrated that perineural dexamethasone

  19. Extremity doses to interventional radiologists

    International Nuclear Information System (INIS)

    Wihtby, M.; Martin, C. J.

    2002-01-01

    Radiologists performing interventional procedures are often required to stand close to the patient's side when carrying out manipulations under fluoroscopic control. This can result in their extremities receiving a high radiation dose, due to scattered radiation. These doses are sometimes high enough to warrant that the radiologist in question be designated a classified radiation worker. Classification in the UK is a result of any worker receiving or likely to receive in the course of their duties in excess of 3/10ths of any annual dose limit (500mSv to extremities, skin). The doses to the legs of radiologists have received less attention than those to the hands, however the doses may be high, due to the proximity of the legs and feet to scattered radiation. The legs can be exposed to a relatively high level of scattered radiation as the radiation in produced from scatter of the un attenuated beam from the bottom of the patient couch. The routine monitoring of extremity doses in interventional radiology is difficult due to several factors. Firstly a wide range of interventional procedures in undertaken in every radiology department, and these procedures require many different techniques, equipment and skills. This means that the position the radiologist adopts in relation to scattering medium and therefore their exposure, depends heavily on the type of procedure. As the hands which manipulate the catheters within the patient are often located close to the patients side and to the area under irradiation, the distribution of dose across the hands can be variable, with very high localised doses, making routine monitoring difficult. The purpose of this study was to determine the magnitude and distribution of dose to the hands and legs of interventional radiologists carrying out a wide range of both diagnostic and therapeutic interventional procedures. To ascertain the most effective method of monitoring the highest dose in accordance with the Basic safety standards

  20. A sub-sampled approach to extremely low-dose STEM

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, A. [OptimalSensing, Southlake, Texas 76092, USA; Duke University, ECE, Durham, North Carolina 27708, USA; Luzi, L. [Rice University, ECE, Houston, Texas 77005, USA; Yang, H. [Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA; Kovarik, L. [Pacific NW National Laboratory, Richland, Washington 99354, USA; Mehdi, B. L. [Pacific NW National Laboratory, Richland, Washington 99354, USA; University of Liverpool, Materials Engineering, Liverpool L69 3GH, United Kingdom; Liyu, A. [Pacific NW National Laboratory, Richland, Washington 99354, USA; Gehm, M. E. [Duke University, ECE, Durham, North Carolina 27708, USA; Browning, N. D. [Pacific NW National Laboratory, Richland, Washington 99354, USA; University of Liverpool, Materials Engineering, Liverpool L69 3GH, United Kingdom

    2018-01-22

    The inpainting of randomly sub-sampled images acquired by scanning transmission electron microscopy (STEM) is an attractive method for imaging under low-dose conditions (≤ 1 e-2) without changing either the operation of the microscope or the physics of the imaging process. We show that 1) adaptive sub-sampling increases acquisition speed, resolution, and sensitivity; and 2) random (non-adaptive) sub-sampling is equivalent, but faster than, traditional low-dose techniques. Adaptive sub-sampling opens numerous possibilities for the analysis of beam sensitive materials and in-situ dynamic processes at the resolution limit of the aberration corrected microscope and is demonstrated here for the analysis of the node distribution in metal-organic frameworks (MOFs).

  1. Long-term Effects of Dexamethasone on Reproductive Parameters in Male Mice

    Directory of Open Access Journals (Sweden)

    jalogoden Gouyandeh

    2015-02-01

    Full Text Available Background & aim: The adverse effect of chemical drugs such as dexamethasone as anti-inflammatory -steroidal drugs on different body systems and infertility and reproductive efficiency is of concern. The purpose of this study was to evaluate the long-term effects of dexamethasone on the reproductive system in male rats. Methods: In the present experimental study, fifty matured male mice were divided into five groups including control, placebo and three treatment groups. Control group had no injections, placebo group only received normal saline and treatments groups received dexamethasone (0.1, 0.5 and 1 mg/kg which was injected in peritoneum every other day for a period of twenty days. Their Testosterone was measured by ELISA and testes were dissected for histological examination. The data were analyzed using SPSS 11.5 software. Results: Significant increases were shown in FSH level in all three groups treated with dexamethasone. LH in treatment group of 0.1 mg/kg decreased, but at dose of 1 mg/kg increased significantly.Testosterone levels in a dose of 1 mg/kg significantly increased compared with the control group (p<0.05. However, testis weight, the rate of testicular germ cells, primary spermatocytes, epididymal sperm and fertility significantly increased in all three groups (p<0.05. Conclusion: Dexamethasone had a negative effect on reproduction therefore, the use of this medication at different doses and time periods considers the possible complications beforehand. Keywords: .

  2. Dexamethasone-induced haptoglobin release by calf liver parenchymal cells.

    Science.gov (United States)

    Higuchi, H; Katoh, N; Miyamoto, T; Uchida, E; Yuasa, A; Takahashi, K

    1994-08-01

    Parenchymal cells were isolated from the liver of male calves, and monolayer cultures formed were treated with glucocorticoids to examine whether haptoglobin, appearance of which is associated with hepatic lipidosis (fatty liver) in cattle, is induced by steroid hormones. Without addition of dexamethasone, only trace amounts of haptoglobin were detected in culture medium. With addition of dexamethasone (10(-12) to 10(-4) M), considerable amounts of haptoglobin were released into the medium. Maximal release was observed at concentrations of 10(-8) to 10(-6) M dexamethasone. Haptoglobin release was similarly induced by cortisol, although the effect was less potent than that of dexamethasone. Actinomycin D (a known protein synthesis inhibitor) dose-dependently reduced amounts of haptoglobin released in response to 10(-8) M dexamethasone. Dexamethasone also induced annexin I, which is known to be synthesized in response to glucocorticoids. Dexamethasone treatment resulted in reduced protein kinase C activity in the cell cytosol, which has been shown to be an early event in dexamethasone-treated cells. Other than glucocorticoids, estradiol induced haptoglobin release, whereas progesterone was less effective. The association of haptoglobin with hepatic lipidosis can be reasonably explained by the fact that haptoglobin production by the liver is induced by glucocorticoids and estradiol, and these steroid hormones are triggers for development of hepatic lipidosis in cattle.

  3. Acute Changes in Mentation in a Patient with Hepatic Cirrhosis Treated with High Doses of Dexamethasone.

    Science.gov (United States)

    Dabul, Luis; Droney, Andrew; Oms, Juan; Sanchez-Gonzalez, Marcos A

    2017-09-10

    Despite the anti-inflammatory benefits of steroids in the management of multiple medical conditions, they are associated with undesired metabolic and psychiatric side effects. We present a case of a 57-year-old Hispanic man with hepatic cirrhosis due to hepatitis C and no past medical history of psychiatric illnesses who became delirious after treatment with high doses of intravenous Dexamethasone. The patient presented to Larkin Community Hospital, USA with complaints of lower back pain requiring treatment with steroids for severe lumbar central canal stenosis. After three days of treatment, the patient became disoriented to time and place, grossly psychotic with auditory hallucinations and disorganized behavior, manic, aggressive, combative, restless, hard to redirect, and unable to follow commands. He met the criteria for a diagnosis of substance-induced psychotic disorder according to Diagnostic and Statistical Manual of Mental Disorders (DSM) V. Furthermore, the patient had worsening hepatic profile, a high ammonia level of 125 umol/L, and clinical findings consistent with West Haven classification grade 2 encephalopathy. Head computed tomography (CT) scan was normal. He was treated with discontinuation of steroids, lactulose, and Haloperidol returning to baseline mental status after 48 hours. The patient's hospitalization was complicated with a prolonged hospital stay after lumbar surgery. This case illustrates that treatment with high doses of Dexamethasone in a patient with hepatic cirrhosis can cause acute changes in mental status by (i) inducing delirium, and (ii) precipitating hepatic encephalopathy.

  4. Multimodal analgesia with gabapentin, ketamine and dexamethasone in combination with paracetamol and ketorolac after hip arthroplasty: a preliminary study

    DEFF Research Database (Denmark)

    Rasmussen, Michael; Mathiesen, Ole; Dierking, Gerd

    2010-01-01

    It has been hypothesized that combinations of analgesics with different mechanisms of action may reduce or even prevent postoperative pain. We, therefore, investigated the analgesic effect of gabapentin, dexamethasone and low-dose ketamine in combination with paracetamol and ketorolac as compared...

  5. A case report of a patient carrying CYP2C9*3/4 genotype with extremely low warfarin dose requirement.

    Science.gov (United States)

    Lee, Soo Youn; Nam, Myung Hyun; Kim, June Soo; Kim, Jong Won

    2007-06-01

    We report a case of intolerance to warfarin dosing due to impaired drug metabolism in a patient with CYP2C9*3/*4. A 73-yr-old woman with atrial fibrilation was taking warfarin. She attained a high prothrombin time international normalized ratio (INR) at the standard doses during the induction of anticoagulation and extremely low dose of warfarin (6.5 mg/week) was finally chosen to reach the target INR. Genotyping for CYP2C9 revealed that this patient had a genotype CYP2C9*3/*4. This is the first Korean compound heterozygote for CYP2C9*3 and *4. This case suggests the clinical usefulness of pharmacogenetic testing for individualized dosage adjustments of warfarin.

  6. Ibrutinib alone or with dexamethasone for relapsed or relapsed and refractory multiple myeloma: phase 2 trial results.

    Science.gov (United States)

    Richardson, Paul G; Bensinger, William I; Huff, Carol Ann; Costello, Caitlin L; Lendvai, Nikoletta; Berdeja, Jesus G; Anderson, Larry D; Siegel, David S; Lebovic, Daniel; Jagannath, Sundar; Laubach, Jacob P; Stockerl-Goldstein, Keith E; Kwei, Long; Clow, Fong; Elias, Laurence; Salman, Zeena; Graef, Thorsten; Bilotti, Elizabeth; Vij, Ravi

    2018-03-01

    Novel therapies with unique new targets are needed for patients who are relapsed/refractory to current treatments for multiple myeloma. Ibrutinib is a first-in-class, once-daily, oral covalent inhibitor of Bruton tyrosine kinase, which is overexpressed in the myeloma stem cell population. This study examined various doses of ibrutinib ± low-dose dexamethasone in patients who received ≥2 prior lines of therapy, including an immunomodulatory agent. Daily ibrutinib ± weekly dexamethasone 40 mg was assessed in 4 cohorts using a Simon 2-stage design. The primary objective was clinical benefit rate (CBR; ≥minimal response); secondary objectives included safety. Patients (n = 92) received a median of 4 prior regimens. Ibrutinib + dexamethasone produced the highest CBR (28%) in Cohort 4 (840 mg + dexamethasone; n = 43), with median duration of 9·2 months (range, 3·0-14·7). Progression-free survival was 4·6 months (range, 0·4-17·3). Grade 3-4 haematological adverse events included anaemia (16%), thrombocytopenia (11%), and neutropenia (2%); grade 3-4 non-haematological adverse events included pneumonia (7%), syncope (3%) and urinary tract infection (3%). Ibrutinib + dexamethasone produced notable responses in this heavily pre-treated population. The encouraging efficacy, coupled with the favourable safety and tolerability profile of ibrutinib, supports its further evaluation as part of combination treatment. © 2018 The Authors. British Journal of Haematology published by John Wiley & Sons Ltd.

  7. ''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)

  8. Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

    Science.gov (United States)

    Madas, Balázs G

    2016-07-01

    Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses.

  9. Multimodal analgesia with gabapentin, ketamine and dexamethasone in combination with paracetamol and ketorolac after hip arthroplasty: a preliminary study

    DEFF Research Database (Denmark)

    Rasmussen, Michael; Mathiesen, Ole; Dierking, Gerd

    2010-01-01

    It has been hypothesized that combinations of analgesics with different mechanisms of action may reduce or even prevent postoperative pain. We, therefore, investigated the analgesic effect of gabapentin, dexamethasone and low-dose ketamine in combination with paracetamol and ketorolac as compared...... with paracetamol and ketorolac alone after hip arthroplasty....

  10. Long-term outcomes and cost effectiveness of high-dose dexamethasone for cardiac surgery : A randomised trial

    NARCIS (Netherlands)

    Dieleman, J. M.; de Wit, G. A.; Nierich, A. P.; Rosseel, P. M.; van der Maaten, J. M.; Hofland, J.; Diephuis, J. C.; de Lange, F.; Boer, C.; Neslo, R. E.; Moons, K. G.; van Herwerden, L. A.; Tijssen, J. G.; Kalkman, C. J.; van Dijk, D.

    Prophylactic intra-operative administration of dexamethasone may improve short-term clinical outcomes in cardiac surgical patients. The purpose of this study was to evaluate long-term clinical outcomes and cost effectiveness of dexamethasone versus placebo. Patients included in the multicentre,

  11. Long-term outcomes and cost effectiveness of high-dose dexamethasone for cardiac surgery: a randomised trial

    NARCIS (Netherlands)

    Dieleman, J. M.; de Wit, G. A.; Nierich, A. P.; Rosseel, P. M.; van der Maaten, J. M.; Hofland, J.; Diephuis, J. C.; de Lange, F.; Boer, C.; Neslo, R. E.; Moons, K. G.; van Herwerden, L. A.; Tijssen, J. G.; Kalkman, C. J.; van Dijk, D.

    2017-01-01

    Prophylactic intra-operative administration of dexamethasone may improve short-term clinical outcomes in cardiac surgical patients. The purpose of this study was to evaluate long-term clinical outcomes and cost effectiveness of dexamethasone versus placebo. Patients included in the multicentre,

  12. Dexamethasone Treatment Leads to Enhanced Fear Extinction and Dynamic Fkbp5 Regulation in Amygdala.

    Science.gov (United States)

    Sawamura, Takehito; Klengel, Torsten; Armario, Antonio; Jovanovic, Tanja; Norrholm, Seth D; Ressler, Kerry J; Andero, Raül

    2016-02-01

    Posttraumatic stress disorder (PTSD) is both a prevalent and debilitating trauma-related disorder associated with dysregulated fear learning at the core of many of its signs and symptoms. Improvements in the currently available psychological and pharmacological treatments are needed in order to improve PTSD treatment outcomes and to prevent symptom relapse. In the present study, we used a putative animal model of PTSD that included presentation of immobilization stress (IMO) followed by fear conditioning (FC) a week later. We then investigated the acute effects of GR receptor activation on the extinction (EXT) of conditioned freezing, using dexamethasone administered systemically which is known to result in suppression of the HPA axis. In our previous work, IMO followed by tone-shock-mediated FC was associated with impaired fear EXT. In this study, we administered dexamethasone 4 h before EXT training and then examined EXT retention (RET) 24 h later to determine whether dexamethasone suppression rescued EXT deficits. Dexamethasone treatment produced dose-dependent enhancement of both EXT and RET. Dexamethasone was also associated with reduced amygdala Fkbp5 mRNA expression following EXT and after RET. Moreover, DNA methylation of the Fkbp5 gene occurred in a dose-dependent and time course-dependent manner within the amygdala. Additionally, we found dynamic changes in epigenetic regulation, including Dnmt and Tet gene pathways, as a function of both fear EXT and dexamethasone suppression of the HPA axis. Together, these data suggest that dexamethasone may serve to enhance EXT by altering Fkbp5-mediated glucocorticoid sensitivity via epigenetic regulation of Fkbp5 expression.

  13. Efficacy of dexamethasone suppression test during the diagnosis of primary pigmented nodular adrenocortical disease in Chinese adrenocorticotropic hormone-independent Cushing syndrome.

    Science.gov (United States)

    Chen, Shi; Li, Ran; Lu, Lin; Duan, Lian; Zhang, Xuebin; Tong, Anli; Pan, Hui; Zhu, Huijuan; Lu, Zhaolin

    2018-01-01

    To evaluate the cut-off value of the ratio of 24 h urinary free cortisol (24 h UFC) levels post-dexamethasone to prior-dexamethasone in dexamethasone suppression test (DST) during the diagnosis of primary pigmented nodular adrenocortical disease in Chinese adrenocorticotropic hormone-independent Cushing syndrome. Retrospective study. The patients diagnosed with primary pigmented nodular adrenocortical disease (PPNAD, n = 25), bilateral macronodular adrenal hyperplasia (BMAH, n = 27), and adrenocortical adenoma (ADA, n = 84) were admitted to the Peking Union Medical College Hospital from 2001 to 2016. Serum cortisol, adrenocorticotropic hormone (ACTH), and 24 h UFC were measured before and after low-dose dexamethasone suppression test (LDDST) and high-dose dexamethasone suppression test (HDDST). After LDDST and HDDST, 24 h UFC elevated in patients with PPNAD (paired t-test, P = 0.007 and P = 0.001), while it remained unchanged in the BMAH group (paired t-test, P = 0.471 and P = 0.414) and decreased in the ADA group (paired t-test, P = 0.002 and P = 0.004). The 24 h UFC level after LDDST was higher in PPNAD and BMAH as compared to ADA (P < 0.017), while no significant difference was observed between PPNAD and BMAH. After HDDST, 24 h UFC was higher in patients with PPNAD as compared to that of ADA and BMAH (P < 0.017). The cut-off value of 24 h UFC (Post-L-Dex)/(Pre-L-Dex) was 1.16 with 64.0% sensitivity and 77.9% specificity, and the cut-off value of 24 h UFC (Post-H-Dex)/(Pre-H-Dex) was 1.08 with 84.0% sensitivity and 75.6% specificity. The ratio of post-dexamethasone to prior-dexamethasone had a unique advantage in distinguishing PPNAD from BMAH and ADA.

  14. Fully Convolutional Architecture for Low-Dose CT Image Noise Reduction

    Science.gov (United States)

    Badretale, S.; Shaker, F.; Babyn, P.; Alirezaie, J.

    2017-10-01

    One of the critical topics in medical low-dose Computed Tomography (CT) imaging is how best to maintain image quality. As the quality of images decreases with lowering the X-ray radiation dose, improving image quality is extremely important and challenging. We have proposed a novel approach to denoise low-dose CT images. Our algorithm learns directly from an end-to-end mapping from the low-dose Computed Tomography images for denoising the normal-dose CT images. Our method is based on a deep convolutional neural network with rectified linear units. By learning various low-level to high-level features from a low-dose image the proposed algorithm is capable of creating a high-quality denoised image. We demonstrate the superiority of our technique by comparing the results with two other state-of-the-art methods in terms of the peak signal to noise ratio, root mean square error, and a structural similarity index.

  15. Impact of dexamethason

    Directory of Open Access Journals (Sweden)

    Zahra Basirat

    2016-09-01

    Full Text Available Objective: Infertile women with polycystic ovary (PCOs involve with anovulatory cycles. Various adjuvant treatments have been suggested to improve ovarian response in these patients. In this study, we aimed to evaluate the role of dexamethasone in the outcome of IVF/ICSI in PCOs infertile women. Study design: 129 PCOs infertile women undergone IVF/ICSI were enrolled for this single blind clinical trial study in 2012–2013. Setting: Fatemezahra Infertility and Reproductive Health Research Center, Babol University of Medical Sciences, Babol, Iran. Method: 43 patients who underwent IVF received dexamethasone (0.5 mg, 4 tab/day in the treatment group and 74 patients were considered as the placebo group. Main outcome measure: Pregnancy rate was compared between the two groups. In addition, number of dominant follicle, oocytes retrieved, embryos transferred, and number of gonadotropin ampoule were evaluated. Results: The pregnancy rate in the group receiving dexamethasone was 17.5% significantly higher versus 4.3% in the placebo group (P < 0.05. The mean number of embryos in the patients received dexamethasone was 6.7 ± 4.3, significantly greater than placebo which was 4.9 ± 4.9 (P < 0.05. The mean number of gonadotropin ampoules used in the group received dexamethasone was 3.5 ± 1.6, significantly lower versus the placebo which was 5.3 ± 2.5 (P < 0.05. The mean number of oocytes in the group received dexamethasone was 11.8 ± 8 and in the placebo group was 9.6 ± 5.8 that was not significant. Conclusion: Dexamethasone enhances embryos and pregnancy rate; in addition, it reduces gonadotropines ampoule used for stimulation, hence, and we recommend using of dexamethasone in women with PCOs undertreatment of IVF/ICSI.

  16. Vorinostat in combination with lenalidomide and dexamethasone in patients with relapsed or refractory multiple myeloma

    International Nuclear Information System (INIS)

    Siegel, D S; Richardson, P; Dimopoulos, M; Moreau, P; Mitsiades, C; Weber, D; Houp, J; Gause, C; Vuocolo, S; Eid, J; Graef, T; Anderson, K C

    2014-01-01

    The addition of vorinostat to lenalidomide/dexamethasone represents a novel combination therapy in multiple myeloma (MM), informed by laboratory studies suggesting synergy. This was a phase I, multicenter, open-label, non-randomized, dose-escalating study in patients with relapsed or relapsed and refractory MM. Clinical evaluation, electrocardiogram, laboratory studies and adverse events were obtained and assessed. The maximum-tolerated dose was not reached owing to a non-occurrence of two dose-limiting toxicities per six patients tested at any of the dosing levels. Patients tolerated the highest dose tested (Level 5) and this was considered the maximum administered dose: at 400 mg vorinostat on days 1–7 and 15–21, 25 mg lenalidomide on days 1–21 and 40 mg dexamethasone on days 1, 8, 15 and 22, per 28-day cycle. Drug-related adverse events were reported in 90% of patients serious adverse experiences were reported in 45% of the patients and 22% of all patients had adverse experiences considered, possibly related to study drug by the investigators. A confirmed partial response or better was reported for 14/30 patients (47%) evaluable for efficacy, including 31% of patients previously treated with lenalidomide. Vorinostat in combination with lenalidomide and dexamethasone proved tolerable with appropriate supportive care, with encouraging activity observed

  17. Endocrinologic and psychological effects of short-term dexamethasone in anorexia nervosa.

    Science.gov (United States)

    Gordon, C M; Emans, S J; DuRant, R H; Mantzoros, C; Grace, E; Harper, G P; Majzoub, J A

    2000-09-01

    Patients with anorexia nervosa (AN) have hyperactivity of their hypothalamic-pituitary-adrenal (HPA) axis, sometimes accompanied by elevations of cortisol. We examined whether the normal effects of short-term dexamethasone treatment upon HPA axis suppression and appetite stimulation are observed in these patients. Five young women with AN and ten healthy female controls received one week of high-dose oral dexamethasone (2 mg/m2/d) preceded and followed by hormonal evaluation of sensitivity to glucocorticoids and psychological assessments. No differences in hormone levels of the HPA axis were observed between the two groups and control groups at baseline, after dexamethasone suppression, or following ACTH stimulation testing. However, fasting insulin levels were significantly lower in the AN group, both before and after dexamethasone therapy and their serum leptin levels were also significantly lower. The AN group had significantly lower scores on the Anorexia Nervosa Subtest and the Beck Depression Inventory after dexamethasone compared to controls. On daily analog scales, AN patients had higher anxiety scores while on dexamethasone. Normal sensitivity to glucocorticoids was observed in all parameters examined except for mild abnormalities in pancreatic beta-cell function. These data suggest that AN may represent a state of partial glucocorticoid resistance, as in other states of restricted food intake. Furthermore, these pilot data, including the effects of dexamethasone upon psychological outlook in AN, suggest that glucocorticoids are not an effective therapy for these patients.

  18. Does Cervical Interlaminar Epidural Steroid Injection with Low-Dose Lidocaine Cause Objective Upper Extremity Weakness? A Preliminary Study.

    Science.gov (United States)

    McCormick, Zachary L; Nelson, Ariana; Kendall, Mark C; McCarthy, Robert J; Nagpal, Geeta; Walega, David R

    2017-12-01

    Low-dose local anesthetic is often used in cervical interlaminar epidural steroid injections (CIESI), yet its effect on upper extremity strength has not been studied. The presence of consequent weakness has potential implications for postprocedure safety. This study aimed to determine whether low-dose lidocaine in a C7-T1 CIESI causes objective weakness. Prospective case series. Academic pain center. Adults, cervical radicular pain. Participants underwent CIESI with 1 mL of 1% lidocaine (3 mL total injectate). Elbow flexion (EF), wrist extension (WE), elbow extension (EE), and handgrip strength were measured by dynamometry at baseline, 15 minutes, and 30 minutes postinjection. Changes in strength from baseline and the proportion of participants with a minimum perceptible change in EF, WE, EE, and handgrip strength (≥20%) and 95% confidence intervals (CIs) were calculated. Twenty-seven participants were included. At 15 and 30 minutes postinjection, there was no within-participant difference in EF, WE, EE, and handgrip strength from baseline overall. Nonetheless, five (19%, 95% CI = 4-33) of the participants demonstrated a 20% or greater strength decrease in at least one myotomal distribution. A 20% or greater decrease in strength was present in left EF 4% (95% CI = 0-11%), right EF 7% (95% CI = 0-17%), left WE 4% (95% CI = 0-11%), and right WE 7% (95% CI = 0-17%). The present data suggest that CIESI with an injectate volume of 3 mL that includes 1 mL of 1% lidocaine may result in objective upper extremity weakness that is above the minimum threshold of perception in a subset of patients. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  19. Avascular necrosis of femoral and/or humeral heads in multiple myeloma: results of a prospective study of patients treated with dexamethasone-based regimens and high-dose chemotherapy.

    Science.gov (United States)

    Talamo, Giampaolo; Angtuaco, Edgardo; Walker, Ronald C; Dong, Li; Miceli, Marisa H; Zangari, Maurizio; Tricot, Guido; Barlogie, Bart; Anaissie, Elias

    2005-08-01

    To assess the prevalence, time of onset, risk factors, and outcome of avascular necrosis (AVN) of bone in patients with multiple myeloma undergoing antineoplastic therapy. A total of 553 consecutive assessable patients were enrolled onto a treatment protocol consisting of dexamethasone-containing induction chemotherapy, autologous stem-cell transplantation, consolidation chemotherapy, and maintenance with interferon alfa. Patients were randomly assigned to receive thalidomide (269 patients) or no thalidomide (284 patients) throughout the study period. With a median follow-up of 33 months (range, 5 to 114 months), AVN of the femoral head(s) developed in 49 patients (9%). Median time to onset of AVN was 12 months (range, 2 to 41 months). Three risk factors for AVN were identified by multivariate analysis: cumulative dexamethasone dose (odds ratio [OR], 1.028; 95% CI, 1.012 to 1.044; P = .0006 [per 40 mg dexamethasone]), male sex (OR, 0.390; 95% CI, 0.192 to 0.790; P = .009), and younger age (OR, 0.961; 95% CI, 0.934 to 0.991 per year; P = .0122). Thalidomide-treated patients had a prevalence of AVN similar to that of the control group (8% v 10%, respectively; P = .58). AVN-related pain and limited range of motion of the affected joint were present in only nine and four patients, respectively, and four patients underwent hip replacement because of AVN. Fluorine-18 fluorodeoxyglucose positron emission tomography failed to detect abnormal uptake in the AVN-affected bones. AVN is a rare and usually asymptomatic complication during myeloma therapy. Cumulative dexamethasone dose, male sex, and younger age, but not thalidomide, increase the risk of AVN.

  20. Effects of trophic exposure to diclofenac and dexamethasone on hematological parameters and immune response in freshwater fish.

    Science.gov (United States)

    Ribas, João Luiz Coelho; Zampronio, Aleksander R; Silva de Assis, Helena C

    2016-04-01

    The aim of the present study was to evaluate the effects of diclofenac and dexamethasone on hematological parameters and immune response in the fish species Hoplias malabaricus after trophic exposure. Fish were fed twice every week with Astyanax sp., which were given an intraperitoneal inoculation with diclofenac (0 μg/kg, 0.2 μg/kg, 2.0 μg/kg, or 20.0 μg/kg) or dexamethasone (0.03 μg/kg, 0.3 μg/kg, or 3.0 μg/kg). After 12 doses, the hematological parameters and lipopolysaccharide-induced nitric oxide production by head kidney monocytic lineage were evaluated. Exposed fish also received 1 mg/kg of carrageenan intraperitoneal, and cell migration to the peritoneal cavity was evaluated after 4 h. Diclofenac and dexamethasone altered the red blood cell count, as well as hematocrit and hemoglobin levels. The total blood leukocyte count decreased in all groups. A significantly reduced carrageenan-induced leukocyte migration to the peritoneal cavity, particularly of polymorphonuclear cells, was observed at all tested doses, suggesting a possible immunosuppressive effect. The basal nitric oxide synthesis of head kidney cell cultures was reduced at the highest dose of diclofenac and was increased at the highest dose of dexamethasone. The lipopolysaccharide-stimulated nitric oxide production was reduced in all treatments, thus corroborating the immunosuppressive effect. Although some fish responses were variable for different drugs, the results suggested that trophic exposure to diclofenac and dexamethasone can lead to hematological changes and immunotoxic effects, causing negative impacts in aquatic organisms. © 2015 SETAC.

  1. Biological influence from low dose and low-dose rate radiation

    International Nuclear Information System (INIS)

    Magae, Junji

    2007-01-01

    Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

  2. Efficacy of two regimens of dexamethasone for management of preterm labour: pilot study

    International Nuclear Information System (INIS)

    Rasool, A.; Farooq, U.

    2017-01-01

    Background: Dexamethasone is widely used for prevention of respiratory distress syndrome (RDS), necrotising enterocolitis (NEC) and intra-ventricular haemorrhage (IVH) in preterm babies; decreasing the neonatal mortality rate. There is no consensus on the dose of corticosteroid administered to the mother expected to have a preterm baby. This study is conducted to compare the effectiveness of two popular regimens of dexamethasone administration in decreasing incidence of RDS, necrotizing enterocolitis, IVH and neonatal mortality rate. Methods: Randomized control trial was conducted at Ayub Teaching Hospital, Abbottabad from 1st to 31st August, 2014. Sample size was set at 50. Block randomization was employed in the trial to allocate the patients into corresponding groups 'A' and 'B'. Group A was administered 6mg dexamethasone in 4 doses 12 hours apart and group B was administered 2 doses 12 hours apart. Results: Forty-eight patients participated in the study with 24 patients in each group. Mean age and period gestation of participants were 28.4 years±4.3 SD and 34 weeks±1.9 SD respectively. Four patients in group A gave birth to neonate with RDS compared to two cases in group B. Group B had higher incidence of necrotizing enterocolitis and neonatal mortalities. However, none of these differences observed were statistically significant. No case of IVH was reported in either of the groups. Conclusion: Both the popular regimens of dexamethasone administration are equally effective in decreasing the incidence of neonatal diseases. (author)

  3. Safety and tolerability of high doses of glucocorticoides

    Directory of Open Access Journals (Sweden)

    Rakić Branislava D.

    2016-01-01

    Full Text Available Introduction: Treatment of acute lymphoblastic leukemia includes the use of high doses of glucocorticoides (prednisone and dexamethasone, which significantly increase the success of therapy due to lymphocytolitic effect. The aim: The aim of the study was to determine tolerability of high doses of prednisone and dexamethasone in children with acute lymphoblastic leukemia and the structure and the intensity of adverse effects, occurred after application of these medicines. Subjects and methods: In a prospective study, we analyzed adverse effects of high doses of glucocorticoides in children suffering acute lymphoblastic leukemia treated in the Institute for Child and Youth Health Care of Vojvodina, since December 2010. until October 2014, were analyzed. This study included 18 patients, aged from 2 to 15 years. Results: Hyperglycemia appeared in 89% of patients treated with prednisone and in 61% of patients treated with dexamethasone. In order to control the high blood glucose level (above 10 mmol /L, in 11% of patients insulin was used. Hypertension appeared in 28% patients treated with prednisone and dexamethasone. Antihypertensives were needed for regulation in 17% patients. Hypopotassemia and hypocalcaemia were significantly more expressed after the use of prednisone in comparison to dexamethasone. In 11% of patients, the treatment with dexamethasone caused depressive behavior, followed by agitation. Conclusion: Adverse effects of dexamethasone and prednisone, administered in high doses in children with ALL were known, expected and reversible. Adverse reactions usually disappeared spontaneously or after short-term symptomatic therapy.

  4. Cyclodextrin-Based Nanohydrogels Containing Polyamidoamine Units: A New Dexamethasone Delivery System for Inflammatory Diseases

    Directory of Open Access Journals (Sweden)

    Monica Argenziano

    2017-06-01

    Full Text Available Glucocorticoids are widely prescribed in treatment of rheumatoid arthritis, asthma, systemic lupus erythematosus, lymphoid neoplasia, skin and eye inflammations. However, well-documented adverse effects offset their therapeutic advantages. In this work, novel nano-hydrogels for the sustained delivery of dexamethasone were designed to increase both bioavailability and duration of the administered drug and reducing the therapeutic dose. Hydrogels are soft materials consisting of water-swollen cross-linked polymers to which the insertion of cyclodextrin (CD moieties adds hydrophobic drug-complexing sites. Polyamidoamines (PAAs are biocompatible and biodegradable polymers apt to create CD moieties in hydrogels. In this work, β or γ-CD/PAA nanogels have been developed. In vitro studies showed that a pretreatment for 24–48 h with dexamethasone-loaded, β-CD/PAA nanogel (nanodexa inhibits adhesion of Jurkat cells to human umbilical vein endothelial cells (HUVEC in conditions mimicking inflammation. This inhibitory effect was faster and higher than that displayed by free dexamethasone. Moreover, nanodexa inhibited COX-2 expression induced by PMA+A23187 in Jurkat cells after 24–48 h incubation in the 10−8–10−5 M concentration range, while dexamethasone was effective only at 10−5 M after 48 h treatment. Hence, the novel nanogel-dexamethasone formulation combines faster action with lower doses, suggesting the potential for being more manageable than the free drug, reducing its adverse side effects.

  5. A multicenter, randomized, controlled trial of dexamethasone for bronchiolitis.

    Science.gov (United States)

    Corneli, Howard M; Zorc, Joseph J; Mahajan, Prashant; Majahan, Prashant; Shaw, Kathy N; Holubkov, Richard; Reeves, Scott D; Ruddy, Richard M; Malik, Baqir; Nelson, Kyle A; Bregstein, Joan S; Brown, Kathleen M; Denenberg, Matthew N; Lillis, Kathleen A; Cimpello, Lynn Babcock; Tsung, James W; Borgialli, Dominic A; Baskin, Marc N; Teshome, Getachew; Goldstein, Mitchell A; Monroe, David; Dean, J Michael; Kuppermann, Nathan

    2007-07-26

    Bronchiolitis, the most common infection of the lower respiratory tract in infants, is a leading cause of hospitalization in childhood. Corticosteroids are commonly used to treat bronchiolitis, but evidence of their effectiveness is limited. We conducted a double-blind, randomized trial comparing a single dose of oral dexamethasone (1 mg per kilogram of body weight) with placebo in 600 children (age range, 2 to 12 months) with a first episode of wheezing diagnosed in the emergency department as moderate-to-severe bronchiolitis (defined by a Respiratory Distress Assessment Instrument score > or =6). We enrolled patients at 20 emergency departments during the months of November through April over a 3-year period. The primary outcome was hospital admission after 4 hours of emergency department observation. The secondary outcome was the Respiratory Assessment Change Score (RACS). We also evaluated later outcomes: length of hospital stay, later medical visits or admissions, and adverse events. Baseline characteristics were similar in the two groups. The admission rate was 39.7% for children assigned to dexamethasone, as compared with 41.0% for those assigned to placebo (absolute difference, -1.3%; 95% confidence interval [CI], -9.2 to 6.5). Both groups had respiratory improvement during observation; the mean 4-hour RACS was -5.3 for dexamethasone, as compared with -4.8 for placebo (absolute difference, -0.5; 95% CI, -1.3 to 0.3). Multivariate adjustment did not significantly alter the results, nor were differences detected in later outcomes. In infants with acute moderate-to-severe bronchiolitis who were treated in the emergency department, a single dose of 1 mg of oral dexamethasone per kilogram did not significantly alter the rate of hospital admission, the respiratory status after 4 hours of observation, or later outcomes. (ClinicalTrials.gov number, NCT00119002 [ClinicalTrials.gov].). Copyright 2007 Massachusetts Medical Society.

  6. Neurodevelopmental Outcomes of Extremely Preterm Infants Randomized to Stress Dose Hydrocortisone.

    Directory of Open Access Journals (Sweden)

    Nehal A Parikh

    Full Text Available To compare the effects of stress dose hydrocortisone therapy with placebo on survival without neurodevelopmental impairments in high-risk preterm infants.We recruited 64 extremely low birth weight (birth weight ≤1000 g infants between the ages of 10 and 21 postnatal days who were ventilator-dependent and at high-risk for bronchopulmonary dysplasia. Infants were randomized to a tapering 7-day course of stress dose hydrocortisone or saline placebo. The primary outcome at follow-up was a composite of death, cognitive or language delay, cerebral palsy, severe hearing loss, or bilateral blindness at a corrected age of 18-22 months. Secondary outcomes included continued use of respiratory therapies and somatic growth.Fifty-seven infants had adequate data for the primary outcome. Of the 28 infants randomized to hydrocortisone, 19 (68% died or survived with impairment compared with 22 of the 29 infants (76% assigned to placebo (relative risk: 0.83; 95% CI, 0.61 to 1.14. The rates of death for those in the hydrocortisone and placebo groups were 31% and 41%, respectively (P = 0.42. Randomization to hydrocortisone also did not significantly affect the frequency of supplemental oxygen use, positive airway pressure support, or need for respiratory medications.In high-risk extremely low birth weight infants, stress dose hydrocortisone therapy after 10 days of age had no statistically significant effect on the incidence of death or neurodevelopmental impairment at 18-22 months. These results may inform the design and conduct of future clinical trials.ClinicalTrials.gov NCT00167544.

  7. Atomoxetine Prevents Dexamethasone-Induced Skeletal Muscle Atrophy in Mice

    Science.gov (United States)

    Jesinkey, Sean R.; Korrapati, Midhun C.; Rasbach, Kyle A.; Beeson, Craig C.

    2014-01-01

    Skeletal muscle atrophy remains a clinical problem in numerous pathologic conditions. β2-Adrenergic receptor agonists, such as formoterol, can induce mitochondrial biogenesis (MB) to prevent such atrophy. Additionally, atomoxetine, an FDA-approved norepinephrine reuptake inhibitor, was positive in a cellular assay for MB. We used a mouse model of dexamethasone-induced skeletal muscle atrophy to investigate the potential role of atomoxetine and formoterol to prevent muscle mass loss. Mice were administered dexamethasone once daily in the presence or absence of formoterol (0.3 mg/kg), atomoxetine (0.1 mg/kg), or sterile saline. Animals were euthanized at 8, 16, and 24 hours or 8 days later. Gastrocnemius muscle weights, changes in mRNA and protein expression of peroxisome proliferator–activated receptor-γ coactivator-1 α (PGC-1α) isoforms, ATP synthase β, cytochrome c oxidase subunit I, NADH dehydrogenase (ubiquinone) 1 β subcomplex, 8, ND1, insulin-like growth factor 1 (IGF-1), myostatin, muscle Ring-finger protein-1 (muscle atrophy), phosphorylated forkhead box protein O 3a (p-FoxO3a), Akt, mammalian target of rapamycin (mTOR), and ribosomal protein S6 (rp-S6; muscle hypertrophy) in naive and muscle-atrophied mice were measured. Atomoxetine increased p-mTOR 24 hours after treatment in naïve mice, but did not change any other biomarkers. Formoterol robustly activated the PGC-1α-4-IGF1–Akt-mTOR-rp-S6 pathway and increased p-FoxO3a as early as 8 hours and repressed myostatin at 16 hours. In contrast to what was observed with acute treatment, chronic treatment (7 days) with atomoxetine increased p-Akt and p-FoxO3a, and sustained PGC-1α expression and skeletal muscle mass in dexamethasone-treated mice, in a manner comparable to formoterol. In conclusion, chronic treatment with a low dose of atomoxetine prevented dexamethasone-induced skeletal muscle wasting and supports a potential role in preventing muscle atrophy. PMID:25292181

  8. Dexamethasone, Intravenous Immunoglobulin, and Rituximab Combination Immunotherapy for Pediatric Opsoclonus-Myoclonus Syndrome.

    Science.gov (United States)

    Pranzatelli, Michael R; Tate, Elizabeth D

    2017-08-01

    Although pulse-dose dexamethasone is increasingly favored for treating pediatric opsoclonus-myoclonus syndrome (OMS), and multimodal immunotherapy is associated with improved clinical response, there have been no neuroimmunologic studies of dexamethasone-based multimodal disease-modifying therapy. In this observational retrospective study, 19 children with OMS (with or without associated neuroblastoma) underwent multibiomarker evaluation for neuroinflammation. Nine children of varying OMS severity, duration, and treatment status were treated empirically with pulse dexamethasone, intravenous immunoglobulin (IVIg), and rituximab combination immunotherapy (DEXIR-CI). Another 10 children on dexamethasone alone or with IVIg at initial evaluation only provided a comparison group. Motor severity (total score) was scored rater-blinded via videotapes using the validated OMS Evaluation Scale. DEXIR-CI was associated with a 69% reduction in group total score (P = 0.004) and was clinically well tolerated. Patients given the dexamethasone combination exhibited significantly lowered B cell frequencies in cerebrospinal fluid (-94%) and blood (-76%), normalizing the cerebrospinal fluid B cell percentage. The number of patients with positive inflammatory markers dropped 87% (P = 0.002) as did the number of markers. Cerebrospinal fluid oligoclonal bands were positive in four of nine pretreatment patients but zero of six post-treatment patients. In the comparison group, partial response to dexamethasone alone or with IVIg was associated with multiple positive markers for neuroinflammation despite an average of seven months of treatment. Multimechanistic dexamethasone-based combination immunotherapy increases the therapeutic armamentarium for OMS, providing a viable option for less severely affected individuals. Partial response to dexamethasone with or without IVIg is indicative of ongoing neuroinflammation and should be treated promptly and accordingly. Copyright © 2017

  9. Application of ALARP to extremity doses for hospital workers

    International Nuclear Information System (INIS)

    Martin, C J; Whitby, M

    2003-01-01

    The implementation of ALARP for hospital workers is considered in relation to extremity doses. Criteria are proposed which could provide guidance in determining strategies for both implementing radiation protection measures and dose monitoring for the extremities. Two groups of hospital workers have been studied, namely interventional radiologists/cardiologists, and radionuclide staff preparing and administering radiopharmaceuticals. The radiology procedures can give high doses to both the hands and legs. Those to the legs can be reduced by the use of lead rubber shields. Study of the distribution of dose across radiologists' hands has identified the ring position on the little finger as the appropriate position for dose monitoring. The variations in dose across the hands of radionuclide workers are greater, with the tip likely to receive the highest dose. The protection strategy will need to be determined for each department, because of the wide range in techniques used in handling radiopharmaceuticals. It is hoped that the criteria could aid balanced decision-making about the appropriate protection strategy and ensure that protection measures are in place where they are required, but avoid their introduction where they are unnecessary

  10. Effects of dexamethasone and insulin on the synthesis of triacylglycerols and phosphatidylcholine and the secretion of very-low-density lipoproteins and lysophosphatidylcholine by monolayer cultures of rat hepatocytes.

    OpenAIRE

    Mangiapane, E H; Brindley, D N

    1986-01-01

    Rat hepatocytes in monolayer culture were preincubated for 19 h with 1 microM-dexamethasone, and the incubation was continued for a further 23 h with [14C]oleate, [3H]glycerol and 1 microM-dexamethasone. Dexamethasone increased the secretion of triacylglycerol into the medium in particles that had the properties of very-low-density lipoproteins. The increased secretion was matched by a decrease in the triacylglycerol and phosphatidylcholine that remained in the hepatocytes. Preincubating the ...

  11. Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil [Keimyung Univ., Daegu (Korea, Republic of)

    2013-12-15

    While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment.

  12. Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

    International Nuclear Information System (INIS)

    Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil

    2013-01-01

    While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment

  13. Glucocorticoid receptors on leukemic cells as evidenced by dexamethasone-induced cytolysis and /sup 3/H-dexamethasone binding

    Energy Technology Data Exchange (ETDEWEB)

    Thraenhardt, H; Haefer, R; Zintl, F

    1987-01-01

    The presence of glucocorticoid receptors on the leukemic cells of 33 patients affected with acute lymphatic leukemia (ALL) and 6 patients affected with acute myeloic leukemia (AML) was investigated by dexamethasone-induced cytolysis and (/sup 3/H)-dexamethasone binding. The tests undertaken proved that after 20 hours of incubation 9 of 26 non-T-non-B-ALL (c-ALL and unclassified ALL) and 2 of AML were lysed with dexamethasone; blood lymphocytes and bone marrow leukocytes of healthy donors, however, were not affected. Non-T-non-B-ALL and AML were able to bind essentially more (/sup 3/H)-dexamethasone than T-ALL. There existed no correlation between dexamethasone binding and dexamethasone-induced cytolysis.

  14. Low doses effects and gamma radiations low dose rates

    International Nuclear Information System (INIS)

    Averbeck, D.

    1999-01-01

    This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

  15. Mechanisms of dexamethasone-induced disturbed sleep and fatigue in paediatric patients receiving treatment for ALL.

    Science.gov (United States)

    Vallance, Kelly; Liu, Wei; Mandrell, Belinda N; Panetta, John C; Gattuso, Jami S; Hockenberry, Marilyn; Zupanec, Sue; Yang, Lei; Yang, Jie; Hinds, Pamela S

    2010-07-01

    Dexamethasone contributes to high cure rates in paediatric acute lymphoblastic leukaemia (ALL) but significantly and adversely alters sleep and fatigue. Herein we explored three mechanisms (pharmacokinetics, serum albumin and pharmacogenetics) through which dexamethasone may cause debilitating fatigue and disrupted sleep. We enrolled 100 patients on a 10-d study: 5-d of no dexamethasone (OFF DEX) followed by 5-d of dexamethasone (ON DEX) during continuation chemotherapy. Sleep variables were collected with continuous actigraphy on days 1 through 5, both OFF DEX and ON DEX. On days 2 and 5 of each 5-d period, parents and patients 7 years of age and older completed a sleep diary and Fatigue Scale questionnaire. Blood was collected at 0 (pre-dexamethasone), 1, 2, 4 and 8 h after the first oral dexamethasone dose for pharmacokinetic analysis. Serum albumin concentration was retrospectively analysed in stored samples. Patient DNA was genotyped for 99 polymorphic loci in candidate genes associated with glucocorticoid metabolism. Dexamethasone clearance was significantly greater in younger patients than in older ones and in lower risk patients. In multiple regression models, risk group was significantly related to pharmacokinetic parameters. We found that polymorphisms in three genes (AHSG, IL6, POLDIP3) were significantly associated with sleep measures but not with fatigue. Risk group had the most significant relationship with disrupted sleep in patients while on dexamethasone. Serum albumin levels had neither a direct relationship with sleep or fatigue variables nor an indirect relationship through systemic exposure to dexamethasone. We identified candidate genes that may help explain the adverse events of disrupted sleep in paediatric patients receiving dexamethasone. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Biodegradable hyaluronic acid hydrogels to control release of dexamethasone through aqueous Diels–Alder chemistry for adipose tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Ming; Ma, Ye; Zhang, Ziwei; Mao, Jiahui [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing (China); Tan, Huaping, E-mail: hptan@njust.edu.cn [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing (China); Hu, Xiaohong [School of Material Engineering, Jinling Institute of Technology, Nanjing (China)

    2015-11-01

    A robust synthetic strategy of biopolymer-based hydrogels has been developed where hyaluronic acid derivatives reacted through aqueous Diels–Alder chemistry without the involvement of chemical catalysts, allowing for control and sustain release of dexamethasone. To conjugate the hydrogel, furan and maleimide functionalized hyaluronic acid were synthesized, respectively, as well as furan functionalized dexamethasone, for the covalent immobilization. Chemical structure, gelation time, morphologies, swelling kinetics, weight loss, compressive modulus and dexamethasone release of the hydrogel system in PBS at 37 °C were studied. The results demonstrated that the aqueous Diels–Alder chemistry provides an extremely selective reaction and proceeds with high efficiency for hydrogel conjugation and covalent immobilization of dexamethasone. Cell culture results showed that the dexamethasone immobilized hydrogel was noncytotoxic and preserved proliferation of entrapped human adipose-derived stem cells. This synthetic approach uniquely allows for the direct fabrication of biologically functionalized gel scaffolds with ideal structures for adipose tissue engineering, which provides a competitive alternative to conventional conjugation techniques such as copper mediated click chemistry. - Highlights: • A biodegradable hyaluronic acid hydrogel was crosslinked via aqueous Diels–Alder chemistry. • Dexamethasone was covalently immobilized into the hyaluronic acid hydrogel via aqueous Diels–Alder chemistry. • Dexamethasone could be released from the Diels–Alder hyaluronic acid hydrogel in a controlled fashion.

  17. Biodegradable hyaluronic acid hydrogels to control release of dexamethasone through aqueous Diels–Alder chemistry for adipose tissue engineering

    International Nuclear Information System (INIS)

    Fan, Ming; Ma, Ye; Zhang, Ziwei; Mao, Jiahui; Tan, Huaping; Hu, Xiaohong

    2015-01-01

    A robust synthetic strategy of biopolymer-based hydrogels has been developed where hyaluronic acid derivatives reacted through aqueous Diels–Alder chemistry without the involvement of chemical catalysts, allowing for control and sustain release of dexamethasone. To conjugate the hydrogel, furan and maleimide functionalized hyaluronic acid were synthesized, respectively, as well as furan functionalized dexamethasone, for the covalent immobilization. Chemical structure, gelation time, morphologies, swelling kinetics, weight loss, compressive modulus and dexamethasone release of the hydrogel system in PBS at 37 °C were studied. The results demonstrated that the aqueous Diels–Alder chemistry provides an extremely selective reaction and proceeds with high efficiency for hydrogel conjugation and covalent immobilization of dexamethasone. Cell culture results showed that the dexamethasone immobilized hydrogel was noncytotoxic and preserved proliferation of entrapped human adipose-derived stem cells. This synthetic approach uniquely allows for the direct fabrication of biologically functionalized gel scaffolds with ideal structures for adipose tissue engineering, which provides a competitive alternative to conventional conjugation techniques such as copper mediated click chemistry. - Highlights: • A biodegradable hyaluronic acid hydrogel was crosslinked via aqueous Diels–Alder chemistry. • Dexamethasone was covalently immobilized into the hyaluronic acid hydrogel via aqueous Diels–Alder chemistry. • Dexamethasone could be released from the Diels–Alder hyaluronic acid hydrogel in a controlled fashion

  18. Extremity doses of medical staff involved in interventional radiology and cardiology: Correlations and annual doses (hands and legs)

    International Nuclear Information System (INIS)

    Krim, S.; Brodecki, M.; Carinou, E.; Donadille, L.; Jankowski, J.; Koukorava, C.; Dominiek, J.; Nikodemova, D.; Ruiz-Lopez, N.; Sans-Merce, M.; Struelens, L.; Vanhavere, F.

    2011-01-01

    An intensive measurement campaign was launched in different hospitals in Europe within work package 1 of the ORAMED project (Optimization of RAdiation protection for MEDical staff). Its main objective was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology (IR) and cardiology (IC) and to optimize staff protection. The monitored procedures were divided in three main categories: cardiac, general angiography and endoscopic retrograde cholangio-pancreatography(ERCP) procedures. Using a common measurement protocol, information such as the protective equipment used (lead table curtain, transparent lead glass ceiling screen, patient shielding, whole body shielding or special cabin etc.) as well as Kerma Area Product (KAP) values and access of the catheter were recorded. This study was performed with a final database of more than 1300 procedures performed in 34 European hospitals. Its objectives were firstly to determine if the measured extremity doses could be correlated to the KAP values; secondly to check if the doses to the eyes could be linked to the doses to the hands (finger or wrist positions) and finally if the doses to the fingers could be estimated based on the doses to the wrists. General correlations were very difficult to find and their strength was mostly influenced by three main parameters: the X-ray tube configuration, the room collective radioprotective equipment and the access of the catheter. The KAP value can provide a simple mean to estimate the extremity doses of the operator given that it is assessed correctly for the operator when he is actually using the X-ray tube. Moreover, this study showed that the doses to the left finger are strongly correlated to the doses to the left wrist when no ceiling shield is used. It is also possible to estimate the doses to the eyes given the doses to the left finger or left wrist but the X-ray tube configuration and the access have to be considered. The annual

  19. Health effect of low dose/low dose rate radiation

    International Nuclear Information System (INIS)

    Kodama, Seiji

    2012-01-01

    The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

  20. Extremely low temperature properties of epoxy GFRP

    International Nuclear Information System (INIS)

    Kadotani, Kenzo; Nagai, Matao; Aki, Fumitake.

    1983-01-01

    The examination of fiber-reinforced plastics, that is, plastics such as epoxy, polyester and polyimide reinforced with high strength fibers such as glass, carbon, boron and steel, for extremely low temperature use began from the fuel tanks of rockets. Therafter, the trial manufacture of superconducting generators and extremely low temperature transformers and the manufacture of superconducting magnets for nuclear fusion experimental setups became active, and high performance FRPs have been adopted, of which the extremely low temperature properties have been sufficiently grasped. Recently, the cryostats made of FRPs have been developed, fully utilizing such features of FRPs as high strength, high rigidity, non-magnetic material, insulation, low heat conductivity, light weight and the freedom of molding. In this paper, the mechanical properties at extremely low temperature of the plastic composite materials used as insulators and structural materials for extremely low temperature superconducting equipment is outlined, and in particular, glass fiber-reinforced epoxy laminates are described somewhat in detail. The fracture strain of GFRP at extremely low temperature is about 1.3 times as large as that at room temperature, but at extremely low temperature, clear cracking occurred at 40% of the fracture strain. The linear thermal contraction of GFRP showed remarkable anisotropy. (Kako, I.)

  1. Research on low radiation doses - A better understanding of low doses

    International Nuclear Information System (INIS)

    2016-01-01

    Radiation doses below 100 mSv are called low doses. Epidemiological research on the health hazards of low doses are difficult to do because numerous pathologies, particularly cancer, appear lifelong for genetical or environmental causes without any link with irradiation and it is very difficult to identify the real cause of a cancer. Another concern is that the impact on human health is weak and are observed only after a long period after irradiation. These features make epidemiological studies cumbersome to implement since they require vast cohorts and a very long-term follow-up. The extrapolation of the effects of higher doses to the domain of low doses does not meet reality and it is why the European Union takes part into the financing of such research. In order to gain efficiency, scientists work together through various European networks among them: HLEG (High Level Expert Group On European Low Dose Risk Research) or MELODI (Multidisciplinary European Low Dose Initiative). Several programs are underway or have been recently launched: -) the impact of Cesium contamination on children's health (Epice program), -) the study of the impact of medical imaging on children, -) the study of the health of children living near nuclear facilities, -) the relationship between radon and lung cancer, -) the effect of occupational low radiation doses, -) the effect of uranium dissolved in water on living organisms (Envirhom program). (A.C.)

  2. Biodegradable hyaluronic acid hydrogels to control release of dexamethasone through aqueous Diels-Alder chemistry for adipose tissue engineering.

    Science.gov (United States)

    Fan, Ming; Ma, Ye; Zhang, Ziwei; Mao, Jiahui; Tan, Huaping; Hu, Xiaohong

    2015-11-01

    A robust synthetic strategy of biopolymer-based hydrogels has been developed where hyaluronic acid derivatives reacted through aqueous Diels-Alder chemistry without the involvement of chemical catalysts, allowing for control and sustain release of dexamethasone. To conjugate the hydrogel, furan and maleimide functionalized hyaluronic acid were synthesized, respectively, as well as furan functionalized dexamethasone, for the covalent immobilization. Chemical structure, gelation time, morphologies, swelling kinetics, weight loss, compressive modulus and dexamethasone release of the hydrogel system in PBS at 37°C were studied. The results demonstrated that the aqueous Diels-Alder chemistry provides an extremely selective reaction and proceeds with high efficiency for hydrogel conjugation and covalent immobilization of dexamethasone. Cell culture results showed that the dexamethasone immobilized hydrogel was noncytotoxic and preserved proliferation of entrapped human adipose-derived stem cells. This synthetic approach uniquely allows for the direct fabrication of biologically functionalized gel scaffolds with ideal structures for adipose tissue engineering, which provides a competitive alternative to conventional conjugation techniques such as copper mediated click chemistry. Copyright © 2015. Published by Elsevier B.V.

  3. A randomized, double-masked, parallel-group, comparative study to evaluate the clinical efficacy and safety of 1% azithromycin–0.1% dexamethasone combination compared to 1% azithromycin alone, dexamethasone 0.1% alone, and vehicle in the treatment of subjects with blepharitis

    Directory of Open Access Journals (Sweden)

    Hosseini K

    2016-08-01

    Full Text Available Kamran Hosseini,1 Richard L Lindstrom,2,3 Gary Foulks,4 Kelly K Nichols5 1InSite Vision, Alameda, CA, 2Minnesota Eye Consultants, 3Department of Ophthalmology and Visual Neurosciences, University of Minnesota Medical School, Minneapolis, MN, 4Department of Ophthalmology and Vision Science, School of Medicine, University of Louisville, Louisville, KY, 5School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA Purpose: To evaluate the clinical efficacy and safety of a 1% azithromycin–0.1% dexamethasone combination in DuraSite (“combination” compared to 0.1% dexamethasone in DuraSite, 1% azithromycin in DuraSite, and vehicle in the treatment of subjects with blepharitis.Materials and methods: This was a Phase III, double-masked, vehicle-controlled, four-arm study in which 907 subjects with blepharitis were randomized to combination (n=305, 0.1% dexamethasone (n=298, 1% azithromycin (n=155, or vehicle (n=149. Ten study visits were scheduled: screening visit, days 1 and 4 (dosing phase and 15, and months 1–6 (follow-up phase. On day 1, subjects applied one drop of the study drug to the eyelid of the inflamed eye(s twice daily, and continued with twice-daily dosing for 14 days. After completing 14 days of dosing, subjects were followed for 6 months for efficacy and safety.Results: A total of 57 subjects (6.3% had complete clinical resolution at day 15: 25 (8.2%, 17 (5.7%, 8 (5.2%, and 7 (4.7% subjects in the combination-, 0.1% dexamethasone-, 1% azithromycin-, and vehicle-treatment groups, respectively. The combination was superior to 1% azithromycin and vehicle alone, but not to 0.1% dexamethasone alone. Mean composite (total clinical sign and symptom scores improved in all four treatment groups during the posttreatment evaluation phase for the intent-to-treat population, but outcomes were superior when a drop containing 0.1% dexamethasone was utilized. Clinical response was noted as early as day 4, and persisted as long

  4. Application of Photoshop-based image analysis and TUNEL for the distribution and quantification of dexamethasone-induced apoptotic cells in rat thymus.

    Science.gov (United States)

    Hussar, Piret; Tokin, Ivan; Hussar, Ulo; Filimonova, Galina; Suuroja, Toivo

    2006-01-01

    The aim of the present study was to determine the target site cells in the rat thymus after exposure to the synthetic glucocorticoid, dexamethasone, at therapeutic doses. The findings of histology and histochemistry (Feulgen, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling--TUNEL) with quantification by computerized histomorphometry are described. A quantified investigation of apoptotic and mitotic thymic lymphocytes in 36 young adult Wistar rats was performed at 1-7 days after a 3-day injection of dexamethasone (a total dose of 1.2 mg/rat intraperitoneally). At the first day after dexamethasone administration the moderate involution and atrophy of thymus histology were observed with simultaneous fall in cortical cellularity and mitotic activity of thymocytes. More rapid fall appeared in the inner cortex. The number of apoptotic (TUNEL-positive) cells was significantly increased. On the days 5 and 7 the expression of apoptosis and the cell proliferation were at almost normal level. The findings suggest that dexamethasone-induced apoptosis of cortical thymic lymphocytes, mainly correlated with synchronous inhibition of mitosis and cell number fall in thymus. The main target sites of dexamethasone injury were cells in the inner cortex of lobuli thymi.

  5. Comparison of 1 mg and 2 mg overnight dexamethasone suppression tests for the screening of Cushing's syndrome in obese patients.

    Science.gov (United States)

    Sahin, Mustafa; Kebapcilar, Levent; Taslipinar, Abdullah; Azal, Omer; Ozgurtas, Taner; Corakci, Ahmet; Akgul, Emin Ozgur; Taslipinar, Mine Yavuz; Yazici, Mahmut; Kutlu, Mustafa

    2009-01-01

    Obesity is currently a major public health problem and one of the potential underlying causes of obesity in a minority of patients is Cushing's syndrome (CS). Traditionally, the gold standard screening test for CS is 1 mg dexamethasone overnight suppression test. However, it is known that obese subjects have high false positive results with this test. We have therefore compared the 1 mg and 2 mg overnight dexamethasone suppression tests in obese subjects. Patients whose serum cortisol after ODST was >50 nM underwent and a low-dose dexamethasone suppression test (LDDST); 24-hour urine cortisol was collected for basal urinary free cortisol (UFC). For positive results after overnight 1-mg dexamethasone suppression test we also performed the overnight 2-mg dexamethasone suppression test. We prospectively evaluated 100 patients (22 men and 78 women, ranging in age from 17 to 73 years with a body mass index (BMI) >30 kg/m2 who had been referred to our hospital-affiliated endocrine clinic because of simple obesity. Suppression of serum cortisol to suppression. Thyroid function tests, lipid profiles, homocysteine, antithyroglobulin, anti-thyroid peroxidase antibody levels, vitamin B12, folate levels, insulin resistance [by homeostasis model assessment (HOMA)] and 1.0 mg postdexamethasone (postdex) suppression cortisol levels were measured. We found an 8% false-positive rate in 1 mg overnight test and 2% in 2 mg overnight test (p=0.001). There was no correlation between the cortisol levels after ODST and other parameters. Our results indicate that the 2 mg overnight dexamethasone suppression test (ODST) is more convenient and accurate than 1-mg ODST as a screening test for excluding CS in subjects with simple obesity.

  6. Measures taken by the supervisory authority to reduce extremity doses in nuclear medicine facilities in Switzerland

    International Nuclear Information System (INIS)

    Stritt, Nicolas; Linder, Reto

    2011-01-01

    In its capacity as the supervisory authority, the Swiss Federal Office of Public Health (SFOPH) has responded to the increase in extremity doses observed in nuclear medicine facilities in Switzerland over the past decade by introducing facility-specific radiation protection audits. These audits have raised the awareness of the staff members concerned with the problem of high extremity doses which arise from handling beta emitters and PET nuclides and prevented any further rise in the extremity doses. However, the evaluation of these audits has also shown that there is still considerable scope for improvement in terms of reducing extremity doses and that further measures are therefore required. Facility-specific and person-specific investigations are currently being conducted with the support of the SFOPH. Their aim is to show facilities which operations during the preparation and application of diagnostic and therapeutic radiopharmaceuticals lead to high extremity doses. This will enable the reduction of extremity doses for nuclear medicine staff as well as ensure that the dose limits are adhered to, in spite of the increasing numbers of examinations.

  7. Three-dimensional measurements of the lower extremity in children and adolescents using a low-dose biplanar X-ray device

    International Nuclear Information System (INIS)

    Gheno, Ramon; Nectoux, Eric; Herbaux, Bernard; Baldisserotto, Matteo; Glock, Luiz; Cotten, Anne; Boutry, Nathalie

    2012-01-01

    To evaluate three-dimensional (3D) measurements of the lower extremity using a biplanar low-dose X-ray device in children and adolescents. Firstly, 3D measurements of eight dried bones were analysed by a biplanar low-dose X-ray device (LDX) using stereoscopic software and compared with 3D computed tomography (CT). Secondly, 47 lower limbs of children and adolescents were studied using LDX two-dimensional (2D) and 3D measurements. Both parts were evaluated for femoral and tibial lengths and mechanical angles, frontal and lateral knee angulations, and the femoral neck-shaft angle. The 3D specimen comparison between LDX and CT measurements showed no significant differences: femoral length (P = 0.069), tibial length (P = 0.059), femoral mechanical angle (P = 0.475), tibial mechanical angle (P = 0.067), frontal knee angulation (P = 0.198), lateral knee angulation (P = 0.646) and femoral neck-shaft angle (P = 0.068). The comparison between LDX 2D and 3D measurements showed significant differences in tibial length (P = 0.003), femoral mechanical angle (P < 0.001) and femoral neck-shaft angle (P = 0.001); other parameters were unremarkable. The 3D LDX system presented reliable measurements compared with 3D CT. Differences between LDX 2D and 3D measurements were noted in the femoral mechanical angle, femoral neck-shaft angle and tibial length. Moderate to good interobserver agreement for the 3D LDX measurements were found. (orig.)

  8. Extreme sensitivity of gene expression in human SH-SY5Y neurocytes to ultra-low doses of Gelsemium sempervirens

    Science.gov (United States)

    2014-01-01

    Background Gelsemium sempervirens L. (Gelsemium s.) is a traditional medicinal plant, employed as an anxiolytic at ultra-low doses and animal models recently confirmed this activity. However the mechanisms by which it might operate on the nervous system are largely unknown. This work investigates the gene expression of a human neurocyte cell line treated with increasing dilutions of Gelsemium s. extract. Methods Starting from the crude extract, six 100 × (centesimal, c) dilutions of Gelsemium s. (2c, 3c, 4c, 5c, 9c and 30c) were prepared according to the French homeopathic pharmacopoeia. Human SH-SY5Y neuroblastoma cells were exposed for 24 h to test dilutions, and their transcriptome compared by microarray to that of cells treated with control vehicle solutions. Results Exposure to the Gelsemium s. 2c dilution (the highest dose employed, corresponding to a gelsemine concentration of 6.5 × 10-9 M) significantly changed the expression of 56 genes, of which 49 were down-regulated and 7 were overexpressed. Several of the down-regulated genes belonged to G-protein coupled receptor signaling pathways, calcium homeostasis, inflammatory response and neuropeptide receptors. Fisher exact test, applied to the group of 49 genes down-regulated by Gelsemium s. 2c, showed that the direction of effects was significantly maintained across the treatment with high homeopathic dilutions, even though the size of the differences was distributed in a small range. Conclusions The study shows that Gelsemium s., a medicinal plant used in traditional remedies and homeopathy, modulates a series of genes involved in neuronal function. A small, but statistically significant, response was detected even to very low doses/high dilutions (up to 30c), indicating that the human neurocyte genome is extremely sensitive to this regulation. PMID:24642002

  9. Effects of dexamethasone and insulin on the synthesis of triacylglycerols and phosphatidylcholine and the secretion of very-low-density lipoproteins and lysophosphatidylcholine by monolayer cultures of rat hepatocytes.

    Science.gov (United States)

    Mangiapane, E H; Brindley, D N

    1986-01-01

    Rat hepatocytes in monolayer culture were preincubated for 19 h with 1 microM-dexamethasone, and the incubation was continued for a further 23 h with [14C]oleate, [3H]glycerol and 1 microM-dexamethasone. Dexamethasone increased the secretion of triacylglycerol into the medium in particles that had the properties of very-low-density lipoproteins. The increased secretion was matched by a decrease in the triacylglycerol and phosphatidylcholine that remained in the hepatocytes. Preincubating the hepatocytes for the total 42 h period with 36 nM-insulin decreased the amount of triacylglycerol in the medium and in the cells after the final incubation for 23 h with radioactive substrates. However, insulin had no significant effect on the triacylglycerol content of the cell and medium when it was present only in the final 23 h incubation. Insulin antagonized the effects of dexamethasone in stimulating the secretion of triacylglycerol from the hepatocytes, especially when it was present throughout the total 42 h period. The labelling of lysophosphatidylcholine in the medium when hepatocytes were incubated with [14C]oleate and [3H]glycerol was greater than that of phosphatidylcholine. The appearance of this lipid in the medium, unlike that of triacylglycerol and phosphatidylcholine, was not stimulated by dexamethasone, or inhibited by colchicine. However, the presence of lysophosphatidylcholine in the medium was decreased when the hepatocytes were incubated with both dexamethasone and insulin. These findings are discussed in relation to the control of the synthesis of glycerolipids and the secretion of very-low-density lipoproteins and lysophosphatidylcholine by the liver, particularly in relation to the interactions of glucocorticoids and insulin. PMID:3513755

  10. Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects

    International Nuclear Information System (INIS)

    Huang, Ambrose J.; Chang, Connie Y.; Palmer, William E.; Thomas, Bijoy J.; MacMahon, Peter J.

    2015-01-01

    To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT. (orig.)

  11. Using cone-beam CT as a low-dose 3D imaging technique for the extremities: initial experience in 50 subjects

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ambrose J.; Chang, Connie Y.; Palmer, William E. [Massachusetts General Hospital, Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Boston, MA (United States); Thomas, Bijoy J. [Universal College of Medical Sciences, Department of Radiology, Bhairahawa (Nepal); MacMahon, Peter J. [Mater Misericordiae University Hospital, Department of Radiology, Dublin 7 (Ireland)

    2015-06-01

    To prospectively evaluate a dedicated extremity cone-beam CT (CBCT) scanner in cases with and without orthopedic hardware by (1) comparing its imaging duration and image quality to those of radiography and multidetector CT (MDCT) and (2) comparing its radiation dose to that of MDCT. Written informed consent was obtained for all subjects for this IRB-approved, HIPAA-compliant study. Fifty subjects with (1) fracture of small bones, (2) suspected intraarticular fracture, (3) fracture at the site of complex anatomy, or (4) a surgical site difficult to assess with radiography alone were recruited and scanned on an extremity CBCT scanner prior to FDA approval. Same-day radiographs were performed in all subjects. Some subjects also underwent MDCT within 1 month of CBCT. Imaging duration and image quality were compared between CBCT and radiographs. Imaging duration, effective radiation dose, and image quality were compared between CBCT and MDCT. Fifty-one CBCT scans were performed in 50 subjects. Average imaging duration was shorter for CBCT than radiographs (4.5 min vs. 6.6 min, P = 0.001, n = 51) and MDCT (7.6 min vs. 10.9 min, P = 0.01, n = 7). Average estimated effective radiation dose was less for CBCT than MDCT (0.04 mSv vs. 0.13 mSv, P = 0.02, n = 7). CBCT images yielded more diagnostic information than radiographs in 23/51 cases and more diagnostic information than MDCT in 1/7 cases, although radiographs were superior for detecting hardware complications. CBCT performs high-resolution imaging of the extremities using less imaging time than radiographs and MDCT and lower radiation dose than MDCT. (orig.)

  12. Development of a real-time extremity dose monitor for personnel in interventional radiology

    International Nuclear Information System (INIS)

    Ban, Nobuhiko; Kusama, Tomoko; Adachi, Akiko

    2000-01-01

    Protection of personnel in interventional radiology is one of the most important issues of radiological protection in medicine. Fluoroscopically guided interventional procedures require the operation near X-ray beam, which brings a considerable hand exposure to the operators. For the purpose of effectual control of their extremity doses, we have developed a real-time extremity dose monitor which is worn on a strap around the wrist. The monitor consists of a silicon semiconductor detector, thin lithium battery and a waterproof frame with a four-digit LED display. Experiment was carried out to examine a response of the monitor to diagnostic X-rays. A practical test was also performed to evaluate usability in the actual interventional procedures. In the experiment, the extremity dose monitor was placed on an arm phantom and exposed to diagnostic X-rays. Readings of the monitor were compared to those of Capintec PS-033 shallow chamber. The monitor was highly sensitive to diagnostic X-rays. It showed a linear response down to doses of a few tens of microsieverts. For high dose-rate exposure, however, a slight decrease in the response was observed, about 10% of counting loss for 80 kV, 40 mA X-ray at one meter from the focus. With regard to energy dependence, variation was within 20% for 60 to 100 kV X-rays. The monitor showed a good angular response in general, except lateral geometry facing the far side from a detector center. In the practical test, hand exposures of medical staff were measured with the extremity dose monitor. They were also asked to fill in a questionnaire regarding size and weight of the monitor, clarity of the display and usefulness. The subjects consisted of physicians, technicians and nurses who engaged in angiography, PTCD, CT-biopsy, barium enema and so on. The readings of the monitor were less than 1 mSv in most cases while 93 mSv was recorded in an extreme case due to direct-beam exposure. In some cases, TLD rings were used together with the

  13. Development of a real-time extremity dose monitor for personnel in interventional radiology

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Nobuhiko; Kusama, Tomoko [Oita University of Nursing and Health Sciences, Oita (Japan); Adachi, Akiko [Oita Medical University, Oita (JP)] [and others

    2000-05-01

    Protection of personnel in interventional radiology is one of the most important issues of radiological protection in medicine. Fluoroscopically guided interventional procedures require the operation near X-ray beam, which brings a considerable hand exposure to the operators. For the purpose of effectual control of their extremity doses, we have developed a real-time extremity dose monitor which is worn on a strap around the wrist. The monitor consists of a silicon semiconductor detector, thin lithium battery and a waterproof frame with a four-digit LED display. Experiment was carried out to examine a response of the monitor to diagnostic X-rays. A practical test was also performed to evaluate usability in the actual interventional procedures. In the experiment, the extremity dose monitor was placed on an arm phantom and exposed to diagnostic X-rays. Readings of the monitor were compared to those of Capintec PS-033 shallow chamber. The monitor was highly sensitive to diagnostic X-rays. It showed a linear response down to doses of a few tens of microsieverts. For high dose-rate exposure, however, a slight decrease in the response was observed, about 10% of counting loss for 80 kV, 40 mA X-ray at one meter from the focus. With regard to energy dependence, variation was within 20% for 60 to 100 kV X-rays. The monitor showed a good angular response in general, except lateral geometry facing the far side from a detector center. In the practical test, hand exposures of medical staff were measured with the extremity dose monitor. They were also asked to fill in a questionnaire regarding size and weight of the monitor, clarity of the display and usefulness. The subjects consisted of physicians, technicians and nurses who engaged in angiography, PTCD, CT-biopsy, barium enema and so on. The readings of the monitor were less than 1 mSv in most cases while 93 mSv was recorded in an extreme case due to direct-beam exposure. In some cases, TLD rings were used together with the

  14. Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu; Magae, Junji

    2008-01-01

    Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

  15. Evaluation of hyperglycaemic response to intra-operative dexamethasone administration in patients undergoing elective intracranial surgery: A randomised, prospective study.

    Science.gov (United States)

    Sethi, Rakesh; Naqash, Imtiaz A; Bajwa, Sukhminder Jit Singh; Dutta, Vikas; Ramzan, Altaf Umar; Zahoor, Syed Amir

    2016-01-01

    The glucocorticoid dexamethasone in a bolus dose of 8-10 mg followed by quarterly dose of 4 mg is commonly used during intracranial surgery so as to reduce oedema and vascular permeability. However, the detrimental hyperglycaemic effects of dexamethasone may override its potentially beneficial effects. The present prospective, randomised study aimed at comparing the degree and magnitude of hyperglycaemia induced by prophylactic administration of dexamethasone in patients undergoing elective craniotomy. Sixty American Society of Anaesthesiologist (ASA) grade-I and II patients were randomly assigned to three groups of 20 patients each. Group-I received dexamethasone during surgery for the first time. Group-II received dexamethasone in addition to receiving it pre-operatively, whereas Group-III (control group) patients were administered normal saline as placebo. Baseline blood glucose (BG) was measured in all the three groups before induction of anaesthesia and thereafter after every hour for 4 h and then two-hourly. Besides intra- and intergroup comparison of BG, peak BG concentration was also recorded for each patient. Statistical analysis was carried out with analysis of variance (ANOVA) and Student's t-test and value of P < 0.05 was considered statistically significant. Baseline BG reading were higher and statistically significant in Group-II as compared with Group-I and Group-III (P < 0.05). However, peak BG levels were significantly higher in Group-I than in Group-II and III (P < 0.05). Similarly, the magnitude of change in peak BG was significantly higher in Group-I as compared to Group-II and III (P < 0.05). Peri-operative administration of dexamethasone during neurosurgical procedures can cause significant increase in BG concentration especially in patients who receive dexamethasone intra-operatively only.

  16. Staff extremity doses in interventional radiology. Results of the ORAMED measurement campaign

    International Nuclear Information System (INIS)

    Nikodemová, D.; Brodecki, M.; Carinou, E.; Domienik, J.; Donadille, L.; Koukorava, C.; Krim, S.; Ruiz-López, N.; Sans-Merce, M.; Struelens, L.; Vanhavere, F.; Zaknoune, R.

    2011-01-01

    The introduction of interventional radiology (IR) procedures in the 20th century has demonstrated significant advantages over surgery procedures. As a result, their number is continuously rising in diagnostic, as well as, in therapy field and is connected with progress in highly sophisticated equipment used for these purposes. Nowadays, in the European countries more than 400 fluoroscopically guided IR procedures were identified with a 10–12% increase in the number of IR examinations every year (). Depending on the complexity of the different types of the interventions large differences in the radiation doses of the staff are observed. The staff that carries out IR procedures is likely to receive relatively high radiation doses, because IR procedures require the operator to remain close to the patient and close to the primary radiation beam. In spite of the fact that the operator is shielded by protective apron, the hands, eyes and legs remain practically unshielded. For this reason, one of the aims of the ORAMED project was to provide a set of standardized data on extremity doses for the personnel that are involved in IR procedures and to optimize their protection by evaluating the various factors that affect the doses. In the framework of work package 1 of the ORAMED project the impact of protective equipment, tube configuration and access routes were analyzed for the selected IR procedures. The position of maximum dose measured is also investigated. The results of the extremity doses in IR workplaces are presented in this study together with the influence of the above mentioned parameters on the doses. -- Highlights: ► We present a set of data on extremity doses for staff in selected interventional radiology procedures. ► We studied the influence of different parameters. ► The measured doses are analyzed according to the operators skill,his position during work, tube configuration, etc. ► Maximum doses recorded for all types of embolisation, in all

  17. Determination of the source of androgen excess in functionally atypical polycystic ovary syndrome by a short dexamethasone androgen-suppression test and a low-dose ACTH test.

    Science.gov (United States)

    Rosenfield, Robert L; Mortensen, Monica; Wroblewski, Kristen; Littlejohn, Elizabeth; Ehrmann, David A

    2011-11-01

    Polycystic ovary syndrome (PCOS) patients typically have 17-hydroxyprogesterone (17OHP) hyperresponsiveness to GnRH agonist (GnRHa) (PCOS-T). The objective of this study was to determine the source of androgen excess in the one-third of PCOS patients who atypically lack this type of ovarian dysfunction (PCOS-A). Aged-matched PCOS-T (n= 40), PCOS-A (n= 20) and controls (n= 39) were studied prospectively in a General Clinical Research Center. Short (4 h) and long (4-7 day) dexamethasone androgen-suppression tests (SDAST and LDAST, respectively) were compared in subsets of subjects. Responses to SDAST and low-dose adrenocorticotropic hormone (ACTH) were then evaluated in all. Testosterone post-SDAST correlated significantly with testosterone post-LDAST and 17OHP post-GnRHa (r = 0.671-0.672), indicating that all detect related aspects of ovarian dysfunction. An elevated dehydroepiandrosterone peak in response to ACTH, which defined functional adrenal hyperandrogenism, was similarly prevalent in PCOS-T (27.5%) and PCOS-A (30%) and correlated significantly with baseline dehydroepiandrosterone sulfate (DHEAS) (r = 0.708). Functional ovarian hyperandrogenism was detected by subnormal testosterone suppression by SDAST in most (92.5%) PCOS-T, but significantly fewer PCOS-A (60%, PPCOS-A, but present in 30% of PCOS-T (P PCOS-A cases with normal testosterone suppression in response to SDAST (5/8) lacked evidence of adrenal hyperandrogenism and were obese. Functional ovarian hyperandrogenism was not demonstrable by SDAST in 40% of PCOS-A. Most of these cases had no evidence of adrenal hyperandrogenism. Obesity may account for most hyperandrogenemic anovulation that lacks a glandular source of excess androgen, and the SDAST seems useful in making this distinction.

  18. Eliminating Postoperative Nausea and Vomiting in Outpatient Surgery with Multimodal Strategies including Low Doses of Nonsedating, Off-Patent Antiemetics: Is “Zero Tolerance“ Achievable?

    Directory of Open Access Journals (Sweden)

    Susan J. Skledar

    2007-01-01

    Full Text Available For ondansetron, dexamethasone, and droperidol (when used for prophylaxis, each is estimated to reduce risk of postoperative nausea and/or vomiting (PONV by approximately 25%. Current consensus guidelines denote that patients with 0–1 risk factors still have a 10–20% risk of encountering PONV, but do not yet advocate routine prophylaxis for all patients with 10–20% risk. In ambulatory surgery, however, multimodal prophylaxis has gained favor, and our previously published experience with routine prophylaxis has yielded PONV rates below 10%. We now propose a “zero-tolerance” antiemetic algorithm for outpatients that involves routine prophylaxis by first avoiding volatile agents and opioids to the extent possible, using locoregional anesthesia, multimodal analgesia, and low doses of three nonsedating off-patent antiemetics. Routine oral administration (immediately on arrival to the ambulatory surgery suite of perphenazine 8 mg (antidopaminergic or cyclizine 50 mg (antihistamine, is followed by dexamethasone 4 mg i.v. after anesthesia induction (dexamethasone is avoided in diabetic patients. At the end of surgery, ondansetron (4 mg i.v., now off-patent is added. Rescue therapy consists of avoiding unnecessary repeat doses of drugs acting by the same mechanism: haloperidol 2 mg i.v. (antidopaminergic is prescribed for patients pretreated with cyclizine or promethazine 6.25 mg i.v. (antihistamine for patients having been pretreated with perphenazine. If available, a consultation for therapeutic acupuncture procedure is ordered. Our approach toward “zero tolerance” of PONV emphasizes liberal identification of and prophylaxis against common risks.

  19. Effects of maternal dexamethasone exposure on hematological ...

    African Journals Online (AJOL)

    Exposure to dexamethasone at LD 1-14 and 1-21 significantly (P<0.05) reduced RBC and platelet counts but it raised MCV and MCH relative to control. This study suggests that prenatal and lactational dexamethasone administration may affect the hematological indices in the male offspring. Keywords: Dexamethasone ...

  20. Low doses effects

    International Nuclear Information System (INIS)

    Tubiana, M.

    1997-01-01

    In this article is asked the question about a possible carcinogens effect of low dose irradiation. With epidemiological data, knowledge about the carcinogenesis, the professor Tubiana explains that in spite of experiments made on thousand or hundred of thousands animals it has not been possible to bring to the fore a carcinogens effect for low doses and then it is not reasonable to believe and let the population believe that low dose irradiation could lead to an increase of neoplasms and from this point of view any hardening of radiation protection standards could in fact, increase anguish about ionizing radiations. (N.C.)

  1. Dexamethasone PONV prophylaxis alters the hypothalamic-pituitary-adrenal axis after transsphenoidal pituitary surgery.

    Science.gov (United States)

    Burkhardt, Till; Rotermund, Roman; Schmidt, Nils-Ole; Kiefmann, Rainer; Flitsch, Jörg

    2014-07-01

    Postoperative nausea and vomiting (PONV) is common after general anesthesia and are reported by approximately 20% to 25% of all patients and up to 39% of patients undergoing neurosurgical procedures. The most common standard prophylaxis is a single application of 4 mg of dexamethasone before initiating anesthesia. Dexamethasone is known to suppress adreno-corticotroph hormone and cortisol levels. The objective was to find out whether this prophylaxis has an effect on the postoperative levels of cortisol in patients undergoing transsphenoidal pituitary surgery, and therefore simulates pituitary deficiency. A retrospective analysis of the files of 136 consecutive patients who were operated during a course of 6 months were included. Nineteen patients with a known history of PONV received a standard dose of 4 mg of dexamethasone perioperatively. Blood tests were drawn at the first postoperative day and were compared with blood tests of patients who had no history of PONV and therefore received no prophylaxis. Patients who were treated with a dexamethasone PONV prophylaxis showed no significant changes in cortisol levels; preoperative median of 93 μg/L (range, 39 to 427) and a postoperative median of 87 μg/L (range, 10 to 733; P=0.798) opposed to patients who did not receive such treatment; preoperative cortisol 114 μg/L (range, 10 to 387) and postoperative levels of 273 μg/L (range, 10 to 1352; Ptranssphenoidal surgery, the probability that dexamethasone PONV prophylaxis suppresses postoperative cortisol levels should be considered.

  2. Biological effects of low doses of radiation at low dose rate

    International Nuclear Information System (INIS)

    1996-05-01

    The purpose of this report was to examine available scientific data and models relevant to the hypothesis that induction of genetic changes and cancers by low doses of ionizing radiation at low dose rate is a stochastic process with no threshold or apparent threshold. Assessment of the effects of higher doses of radiation is based on a wealth of data from both humans and other organisms. 234 refs., 26 figs., 14 tabs

  3. Dexamethasone Therapy for Bacterial Meningitis: Better Never Than Late?

    Directory of Open Access Journals (Sweden)

    Susan M King

    1994-01-01

    Full Text Available A multicentre randomized controlled trial was conducted in children with bacterial meningitis using dexamethasone or placebo for four days within 24 h of starting antibiotics. Primary outcomes were hearing loss and neurological abnormalities at 12 months after meningitis. The dexamethasone (n=50 and placebo (n=51 groups were similar in age, severity of illness and etiological agent. Hearing loss occurred in 10% and 11% of the dexamethasone and placebo groups and neurological deficits occurred in 20% and 18% of patients, respectively. Duodenal perforation occurred in one dexamethasone-treated child. In conclusion, there was no significant benefit in those receiving dexamethasone. The lack of benefit may have been due to the delay in administration of dexamethasone (median delay of 11 h after antibiotics. Therefore, if dexamethasone is used for meningitis it should be given immediately with the antibiotic.

  4. Sustained release ophthalmic dexamethasone: In vitro in vivo correlations derived from the PK-Eye.

    Science.gov (United States)

    Awwad, Sahar; Day, Richard M; Khaw, Peng T; Brocchini, Steve; Fadda, Hala M

    2017-04-30

    Corticosteroids have long been used to treat intraocular inflammation by intravitreal injection. We describe dexamethasone loaded poly-DL-lactide-co-glycolide (PLGA) microparticles that were fabricated by thermally induced phase separation (TIPS). The dexamethasone loaded microparticles were evaluated using a two-compartment, in vitro aqueous outflow model of the eye (PK-Eye) that estimates drug clearance time from the back of the eye via aqueous outflow by the anterior route. A dexamethasone dose of 0.20±0.02mg in a 50μL volume of TIPS microparticles resulted in a clearance t 1/2 of 9.6±0.3days using simulated vitreous in the PK-Eye. Since corticosteroids can also clear through the retina, it is necessary to account for clearance through the back of the eye. Retinal permeability data, published human ocular pharmacokinetics (PK) and the PK-Eye clearance times were then used to establish in vitro in vivo correlations (IVIVCs) for intraocular clearance times of corticosteroid formulations. A t 1/2 of 48h was estimated for the dexamethasone-TIPS microparticles, which is almost 9 times longer than that reported for dexamethasone suspension in humans. The prediction of human clearance times of permeable molecules from the vitreous compartment can be determined by accounting for drug retinal permeation and determining the experimental clearance via the anterior aqueous outflow pathway using the PK-Eye. Copyright © 2017. Published by Elsevier B.V.

  5. Examination of dexamethasone sodium sulfate and hyperbaric oxygenation in experimentally produced cerebral edema. With special reference to their combination

    Energy Technology Data Exchange (ETDEWEB)

    Kanaya, H; Onodera, H; Watanabe, M; Kamata, K [Iwate Medical Coll., Morioka (Japan). School of Medicine

    1975-06-01

    Dexamethasone sodium sulfate and hyperbaric oxygenation were used for experimentally produced cerebral edema for the examination of the water content of the brain and cerebrovascular permeability using /sup 203/Hg as the tracer. Although dexamethasone starts lowering vascular permeability of the edematous brain at one hour after the intravenous injection, a lapse of 24 hours is required until the water content returns to normal. Although hyperbaric oxygenation dose not reduce cerebrovascular permeability, it brings back the water content of the brain to normal immediately after pressurization. Since the combination of dexamethasone and hyperbaric oxygenation maintains the water content of the brain almost normal throughout the entire process, it is ideal for the treatment of cerebral edema.

  6. Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Bobby, R., Ph.D.

    2003-06-27

    OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase one¡¯s risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on

  7. On the influence of dexamethason-21-iso-nicotinate on histamine blood level in horses with reference to the facultative occurrence of laminitis

    International Nuclear Information System (INIS)

    Rautschka, R.

    1987-10-01

    In some cases laminitis may result as a consequence of corticoid therapy in horses. It was the aim of this investigation to prove, if there is a connection between therapeutic doses of a corticoid (dexamethasone-21-iso-nicotinate) and the liberation of histamine into the equine plasma. 40 veterinarians reported 23 cases of laminitis after treating the horses with various corticoids. To determine histamine levels in equine plasma, a method used in human medicine (Faraj, 1984) was adapted accordingly. The principle of this method consists of enzymatic coupling of a tritium-labelled methyl group to the histamine contained in plasma. From the investigation the conclusion could be drawn, that it was not possible to induce liberation of histamine into equine plasma by therapeutic doses of dexamethasone-21-iso-nicotinate. Finally, plasma levels of three horses, suffering from chronical obstructive pulmonary disease (COPD) treated therapeutically with dexamethasone-21-iso-nicotinate, were determined. Conclusively a connection between the i.m. application of dexamethasone-21-iso-nicotinate and an inducement of histamine liberation into equine plasma could not be proven. 226 refs., 11 figs., 12 tabs. (G.Q.)

  8. Characteristics of repair following very low doses

    International Nuclear Information System (INIS)

    Braby, L.A.; Metting, N.F.; Nelson, J.M.

    1987-01-01

    The effects of ionizing radiation on living systems being with the physical processes of energy deposition and develop through many stages of chemical reaction and biological response. The modeling effort attempts to organize the available data and theories of all of these stages into self-consistent models that can be compared and tested. In some cases, important differences among models result in only small differences in cell survival within the ranges of dose and dose rate that are normally investigated. To overcome this limitation, new ways of irradiating cells at extremes of dose rate, or ways of evaluating the effects of very small doses, are developed. Mathematical modeling and cellular studies complement each other. It has recently been found that some mechanisms are not adequate to account for the interaction of dose and repair time as they affect the reproductive survival of plateau-phase Chinese hamster ovary (CHO) cells. Repair of radiation-induced cellular damage plays a central role in the survival of cells exposed to doses of 1 Gy or more. This repair is responsible for the dose rate, split-dose and delayed plating effect and can be evaluated. Because split-dose and dose-rate experiments involve repair during irradiation and delayed plating experiments involve repair after irradiation is completed, it was originally thought that different repair processes were involved. It is now clear that this is not necessarily the case. Appropriately designed models can account for observed effects at conventional doses (1 Gy or more) whether they assume all damage is lethal unless repaired or some damage is innocuous unless it interacts with additional damage. The fact that the survival following a plating delay is always less than the survival following immediate plating at low doses indicates that the damage produced is probably not potentially lethal

  9. Evaluation of occupational radiation dose of extremities on hysterosalpingography

    International Nuclear Information System (INIS)

    Filipov, D.; Kotowski, S.T.A.

    2017-01-01

    In the Hysterosalpingography (HSG) exam there is always a professional present with their hands very close to the radiation field. Based on CNEN, individuals occupationally exposed to radiation have equivalent dose limit values for the extremities (500 mSv / year). The objective of the study was to verify the equivalent dose in the hand region of an IOE (Occupationally Exposed Individual) that performs the HSG test and to compare it with the CNEN limit and with similar studies. A humanoid phantom was used to simulate the patient and an ionization chamber, which was placed in the place commonly occupied by the professional. The equivalent hand dose result (∼ 30 mSv / year) equals 6% of the CNEN annual dose limit, but is close to most studies using fluoroscopes. Therefore, the optimization of radiological protection is necessary to reduce these results

  10. Extremity dosimetry in medical applications within Europe: an overview of doses and monitoring practices

    International Nuclear Information System (INIS)

    Donadille, Laurent; Carinou, E.; Ginjaume, M.; Jankowski, J.; Rimpler, A.; Sans Merce, M.; Vanhavere, F.

    2008-01-01

    Full text: Some activities of the EURADOS Working Group 9 (WG9) related to the radiation protection dosimetry of medical staff were funded by the European Commission in the framework of the CONRAD project, Work Package 7. The objective of WG9 was to promote and co-ordinate research activities for the assessment of occupational exposure to staff at workplaces in therapeutic and diagnostic radiology and nuclear medicine. At these workplaces, from the point of view of the individual monitoring for external radiation, the skin of the fingers is generally the limiting organ. Subgroup 1 of WG9 had as main objective the study of the use of extremity dosemeters in medical radiation fields. The wide variety of radiation field characteristics present in medicine together with the difficulties of measuring a local dose which should be representative for the maximum skin dose using one single detector, makes it difficult to perform extremity dosimetry with an accuracy similar to that of whole-body one. A recent intercomparison organised by WG9 showed that some types of dosemeters significantly underestimate or overestimate skin doses. Subgroup 1 carried out a thorough literature review on extremity dosimetry issues. It covered diagnostic and therapeutic nuclear medicine and PET, interventional radiology and cardiology, and brachytherapy. It has notably pointed out the consensus about the requirement of regular extremity dose monitoring for nuclear medicine and PET, and the great difficulty of measuring extremity doses for procedures in interventional radiology and cardiology, activities for which routine extremity dose monitoring has been found to be poor. Furthermore, information on the status of extremity dosimetry in medical applications and associated monitoring practices was gathered from 7 European countries: France, Germany, Greece, Ireland, Poland, Spain and Switzerland. Interpretation of the data was not easy because of the wide range of procedures involved and also

  11. Calculation of neutron fluence-to-dose conversion factors for extremities

    International Nuclear Information System (INIS)

    Stewart, R.D.; Harty, R.; McDonald, J.C.; Tanner, J.E.

    1993-04-01

    The Pacific Northwest Laboratory is developing a standard for the performance testing of personnel extremity dosimeters for the US Department of Energy. Part of this effort requires the calculation of neutron fluence-to-dose conversion factors for finger and wrist extremities. This study focuses on conversion factors for two types of extremity models: namely the polymethyl methacrylate (PMMA) phantom (as specified in the draft standard for performance testing of extremity dosimeters) and more realistic extremity models composed of tissue-and-bone. Calculations for each type of model are based on both bare and D 2 O-moderated 252 Cf sources. The results are then tabulated and compared with whole-body conversion factors. More appropriate energy-averaged quality factors for the extremity models have also been computed from the neutron fluence in 50 equally spaced energy bins with energies from 2.53 x 10 -8 to 15 MeV. Tabulated results show that conversion factors for both types of extremity phantom are 15 to 30% lower than the corresponcung whole-body phantom conversion factors for 252 Cf neutron sources. This difference in extremity and whole-body conversion factors is attributable to the proportionally smaller amount of back-scattering that occurs in the extremity phantoms compared with whole-body phantoms

  12. Occupational radiation exposure to low doses of ionizing radiation and female breast cancer

    International Nuclear Information System (INIS)

    Adelina, P.; Bliznakov, V.; Bairacova, A.

    2003-01-01

    The aim of this study is to examine the relationship between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed and registered breast cancer [probability of causation - PC] among Bulgarian women who have used different ionizing radiation sources during their working experience. The National Institute of Health (NIH) in US has developed a method for estimating the probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed cancer. We have used this method. A group of 27 women with diagnosed breast cancer has been studied. 11 of them are former workers in NPP - 'Kozloduy', and 16 are from other sites using different sources of ionizing radiation. Analysis was performed for 14 women, for whom full personal data were available. The individual radiation dose for each of them is below 1/10 of the annual dose limit, and the highest cumulative dose for a period of 14 years of occupational exposure is 50,21 mSv. The probability of causation (PC) values in all analyzed cases are below 1%, which confirms the extremely low probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and occurring cases of breast cancer. (orig.)

  13. Pulsed high-dose dexamethasone modulates Th1-/Th2-chemokine imbalance in immune thrombocytopenia.

    Science.gov (United States)

    Liu, Zongtang; Wang, Meiying; Zhou, Shufen; Ma, Ji; Shi, Yan; Peng, Jun; Hou, Ming; Guo, Chengshan

    2016-10-24

    Chemokines and chemokine receptors play important roles in autoimmune diseases; however, their role in immune thrombocytopenia (ITP) is unclear. High-dose dexamethasone (HD-DXM) may become a first-line therapy for adult patients with ITP, but the effect of HD-DXM on chemokines in ITP patients is unknown. Our aim was to investigate the mechanism of pulsed HD-DXM for management of ITP, specifically regarding the chemokine pathways. Th1-/Th2-associated chemokine and chemokine receptor profiles in ITP patients before and after pulsed HD-DXM was studied. Plasma levels of CCL5 and CXCL11 (Th1-associated) and of CCL11 (Th2-associated) were determined by ELISA. Gene expression of these three chemokines and their corresponding receptors CCR5, CXCR3, and CCR3, in peripheral blood mononuclear cells (PBMCs) was determined by quantitative RT-PCR. Thirty-three of the thirty-eight ITP patients responded effectively to HD-DXM (oral, 40 mg/day, 4 days). In ITP patients, plasma CXCL11 levels increased, while CCL11 and CCL5 decreased compared to controls (P Th1-/Th2-associated chemokines and chemokine receptors may play important roles in the pathogenesis of ITP. Importantly, regulating Th1 polarization by pulsed HD-DXM may represent a novel approach for immunoregulation in ITP.

  14. The effects of dexamethasone on post-asphyxial cerebral oxygenation in the preterm fetal sheep

    Science.gov (United States)

    Lear, Christopher A; Koome, Miriam E; Davidson, Joanne O; Drury, Paul P; Quaedackers, Josine S; Galinsky, Robert; Gunn, Alistair J; Bennet, Laura

    2014-01-01

    Exposure to clinical doses of the glucocorticoid dexamethasone increases brain activity and causes seizures in normoxic preterm fetal sheep without causing brain injury. In contrast, the same treatment after asphyxia increased brain injury. We hypothesised that increased injury was in part mediated by a mismatch between oxygen demand and oxygen supply. In preterm fetal sheep at 0.7 gestation we measured cerebral oxygenation using near-infrared spectroscopy, electroencephalographic (EEG) activity, and carotid blood flow (CaBF) from 24 h before until 72 h after asphyxia induced by 25 min of umbilical cord occlusion. Ewes received dexamethasone intramuscularly (12 mg 3 ml–1) or saline 15 min after the end of asphyxia. Fetuses were studied for 3 days after occlusion. During the first 6 h of recovery after asphyxia, dexamethasone treatment was associated with a significantly greater fall in CaBF (P < 0.05), increased carotid vascular resistance (P < 0.001) and a greater fall in cerebral oxygenation as measured by the difference between oxygenated and deoxygenated haemoglobin (delta haemoglobin; P < 0.05). EEG activity was similarly suppressed in both groups. From 6 to 10 h onward, dexamethasone treatment was associated with a return of CaBF to saline control levels, increased EEG power (P < 0.005), greater epileptiform transient activity (P < 0.001), increased oxidised cytochrome oxidase (P < 0.05) and an attenuated increase in [delta haemoglobin] (P < 0.05). In conclusion, dexamethasone treatment after asphyxia is associated with greater hypoperfusion in the critical latent phase, leading to impaired intracerebral oxygenation that may exacerbate neural injury after asphyxia. PMID:25384775

  15. The efficacy of dexamethasone reducing postoperative pain and emesis after total knee arthroplasty: A systematic review and meta-analysis.

    Science.gov (United States)

    Fan, Zhengrui; Ma, Jianxiong; Kuang, Mingjie; Zhang, Lukai; Han, Biao; Yang, Baocheng; Wang, Ying; Ma, Xinlong

    2018-04-01

    Total knee arthroplasty (TKA) is gradually emerging as the treatment of choice for end-stage osteoarthritis. In the past, Perioperative dexamethasone treatment is still a controversial subject in total knee arthroplasty. Therefore, we write this systematic review and meta-analysis to evaluate the efficacy of dexamethasone on pain and recovery after Total knee Arthroplasty. Embase, Pubmed, and Cochrane Library were comprehensively searched. Randomized controlled trials, cohort studies were included in our meta-analysis. Eight studies that compared dexamethasone groups with placebo groups were included in our meta-analysis. The research was reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. Randomized controlled trials were included in our meta-analysis. Our study demonstrated that the dexamethasone group was more effective than the placebo group in term of VAS score at 24 h(P meta-analysis demonstrated that dexamethasone decreased postoperative pain, the incidence of POVN, and total opioid consumption effectively which played a critical role in rapid recovery to TKA. However, we still need large sample size, high quality studies to explore the relationship between complications and dose response to give the final conclusion. Copyright © 2018. Published by Elsevier Ltd.

  16. Competitive inhibition of [3H]dexamethasone binding to mammary glucocorticoid receptor by leupeptin

    International Nuclear Information System (INIS)

    Hsieh, L.C.C.; Su, C.; Markland, F.S. Jr.

    1987-01-01

    The inhibitory effect of leupeptin on [ 3 H]dexamethasone binding to the glucocorticoid receptor from lactating goat mammary cytosol has been studied. Leupeptin (10 mM) caused a significant (about 35%) inhibition of [ 3 H]dexamethasone binding to glucocorticoid receptor. Binding inhibition is further increased following filtration of unlabeled cytosolic receptor through a Bio-Gel A 0.5-m column. Binding inhibition was partially reversed by monothioglycerol at 10 mM concentration. A double reciprocal plot revealed that leupeptin appears to be a competitive inhibitor of [ 3 H]dexamethasone binding to the glucocorticoid receptor. Low salt sucrose density gradient centrifugation revealed that the leupeptin-treated sample formed a slightly larger (approximately 9 S) receptor complex (leupeptin-free complex sediments at 8 S)

  17. Low-dose radiation as an environmental agent affecting intrauterine development

    International Nuclear Information System (INIS)

    Kameyama, Yoshiro

    1982-01-01

    The low-dose radiation effects which have been recognized in mammalian teratological studies are direct injuries to the particularly radiosensitive tissues of embryo and fetus, and increased incidences of spontaneous malformations and minor anomalies. The lowest radiation doses for manifestation of those effects in mice and rats are: 5 rad for resorption of preimplantation embryos; 5-10 rad for acute cytological changes such as pyknosis, cytoplasmic degeneration and mitotic delay; 5 rad for increasing frequency of spontaneous minor anomalies of the skeleton; 15-20 rad for malformations of the eye, brain and spinal cord; 20-25 rad for histogenetic and functional disorders of the central nervous system; and 20-25 rad for impaired fertility. Pregnant women who are subject to X-ray examination are much concerned about potential hazard of radiation to their offspring in utero. The above experimental findings suggest that the possibility of teratogenic effects of diagnostic radiation on human embryos and fetuses is extremely low, and probably negligible, given the proper dose control measures. (author)

  18. Cortisol secretion after adrenocorticotrophin (ACTH and Dexamethasone tests in healthy female and male dogs

    Directory of Open Access Journals (Sweden)

    Castillo Victor

    2009-08-01

    Full Text Available Abstract Background For the conclusive diagnosis of Cushing's Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs. Methods Seven healthy adult Cocker Spaniels (4 females and 3 males were assigned to a two by two factorial design: 4 dogs (2 females and 2 males received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group. Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal to 4 dogs (2 female and 2 males while the rest was treated with saline solution (control group. Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits. Results and Discussion No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection. Conclusion We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex.

  19. Cyclophosphamide, thalidomide, and dexamethasone as induction therapy for newly diagnosed multiple myeloma patients destined for autologous stem-cell transplantation: MRC Myeloma IX randomized trial results

    Science.gov (United States)

    Morgan, Gareth J.; Davies, Faith E.; Gregory, Walter M.; Bell, Sue E.; Szubert, Alexander J.; Navarro Coy, Nuria; Cook, Gordon; Feyler, Sylvia; Johnson, Peter R.E.; Rudin, Claudius; Drayson, Mark T.; Owen, Roger G.; Ross, Fiona M.; Russell, Nigel H.; Jackson, Graham H.; Child, J. Anthony

    2012-01-01

    Background Thalidomide is active in multiple myeloma and is associated with minimal myelosuppression, making it a good candidate for induction therapy prior to high-dose therapy with autologous stem-cell transplantation. Design and Methods Oral cyclophosphamide, thalidomide, and dexamethasone was compared with infusional cyclophosphamide, vincristine, doxorubicin, and dexamethasone in patients with newly diagnosed multiple myeloma. Results The post-induction overall response rate (≥ partial response) for the intent-to-treat population was significantly higher with cyclophosphamide-thalidomide-dexamethasone (n=555) versus cyclophosphamide-vincristine-doxorubicin-dexamethasone (n=556); 82.5% versus 71.2%; odds ratio 1.91; 95% confidence interval 1.44–2.55; P<0.0001. The complete response rates were 13.0% with cyclophosphamide-thalidomide-dexamethasone and 8.1% with cyclophos-phamide-vincristine-doxorubicin-dexamethasone (P=0.0083), with this differential response being maintained in patients who received autologous stem-cell transplantation (post-transplant complete response 50.0% versus 37.2%, respectively; P=0.00052). Cyclophosphamide-thalidomide-dexamethasone was non-inferior to cyclophosphamide-vincristine-doxorubicin-dexamethasone for progression-free and overall survival, and there was a trend toward a late survival benefit with cyclophosphamide-thalidomide-dexamethasone in responders. A trend toward an overall survival advantage for cyclophosphamide-thalidomide-dexamethasone over cyclophosphamide-vincristine-doxorubicin-dexamethasone was also observed in a subgroup of patients with favorable interphase fluorescence in situ hybridization. Compared with cyclophosphamide-vincristine-doxorubicin-dexamethasone, cyclophosphamide-thalidomide-dexamethasone was associated with more constipation and somnolence, but a lower incidence of cytopenias. Conclusions The cyclophosphamide-thalidomide-dexamethasone regimen showed improved response rates and was not inferior

  20. The effect of dexamethasone on respirator-dependent very-low-birth-weight infants is best predicted by chest X-ray

    International Nuclear Information System (INIS)

    Schrod, L.; Neuhaus, T.; Horwitz, A.E.; Speer, C.P.

    2001-01-01

    Background. Chronic lung disease (CLD) in premature infants shows a variable clinical course with different radiological manifestations. Objective. To evaluate the correlation between parameters of transmembrane permeability [albumin/secretory component (SC)] and oxidative stress [malondialdehyde (MDA)/SC] in tracheal aspirate fluid (TAF) and radiological findings with the effect of a 5-day course of dexamethasone (0.5 mg/kg per day). Materials and methods. Fifty ventilator-dependent premature infants with birth weights 2 x mean airway pressure > 40 % at day 5, compared to pretreatment values. About 80 % of the responders showed homogeneous lung opacification on chest X-ray, reflecting leaky lung syndrome. In contrast, seven of eight infants with predominantly emphysema on radiology were non-responders; 80 % of infants with a mixed radiological picture characterized by predominance of consolidations alternating with regions of emphysema were also non-responders. Ratios of albumin/SC and MDA/SC in TAF decreased significantly within 3 days after the onset of dexamethasone. However, MDA/SC was persistently higher in non-responders compared to responders. Opaque lungs were largely improved by dexamethasone, in contrast to streaky or patchy consolidations and emphysema. In a logistic regression model, radiographic classification was the most important factor influencing the response to dexamethasone with a positive predictive value of 86 %, followed by albumin/SC ratio. Conclusions. The optimum timing of dexamethasone treatment may be determined by the stage of developing CLD and radiological findings rather than by the age of the premature infant. (orig.)

  1. Outcome with lenalidomide plus dexamethasone followed by early autologous stem cell transplantation in patients with newly diagnosed multiple myeloma on the ECOG-ACRIN E4A03 randomized clinical trial: long-term follow-up.

    Science.gov (United States)

    Biran, N; Jacobus, S; Vesole, D H; Callander, N S; Fonseca, R; Williams, M E; Abonour, R; Katz, M S; Rajkumar, S V; Greipp, P R; Siegel, D S

    2016-09-02

    In Eastern Cooperative Oncology Group-ACRIN E4A03, on completion of four cycles of therapy, newly diagnosed multiple myeloma patients had the option of proceeding to autologous peripheral blood stem cell transplant (ASCT) or continuing on their assigned therapy lenalidomide plus low-dose dexamethasone (Ld) or lenalidomide plus high-dose dexamethasone (LD). This landmark analysis compared the outcome of 431 patients surviving their first four cycles of therapy pursuing early ASCT to those continuing on their assigned therapy. Survival distributions were estimated using the Kaplan-Meier method and compared with log-rank test. Ninety patients (21%) opted for early ASCT. The 1-, 2-, 3-, 4- and 5-year survival probability estimates were higher for early ASCT versus no early ASCT at 99, 93, 91, 85 and 80% versus 94, 84, 75, 65 and 57%, respectively. The median overall survival (OS) in the early versus no early ASCT group was not reached (NR) versus 5.78 years. In patients 50, 0.25). In patients ⩾65 years of age, median OS in the early versus no early ASCT was NR versus 5.11 years. ASCT dropped out of statistical significance (P=0.080). Patients opting for ASCT after induction Ld/LD had a higher survival probability and improvement in OS regardless of dexamethasone dose density.

  2. High performance liquid chromatography determination of dexamethasone in plasma to evaluate its systemic absorption following intra-space pterygomandibular injection of twin-mix (mixture of 2 % lignocaine with 1:200,000 epinephrine and 4 mg dexamethasone): randomized control trial.

    Science.gov (United States)

    Bhargava, Darpan; Deshpande, Ashwini; Thomas, Shaji; Sharma, Yogesh; Khare, Piush; Sahu, Sanjeev Kumar; Dubey, Suyash; Pandey, Ankit; Sreekumar, K

    2016-09-01

    To determine systemic absorption of dexamethasone by detection of plasma concentration using high performance liquid chromatography following its administration along with local anesthetic agent as a mixture via pterygomandibular space. A prospective randomized double-blind clinical study was undertaken to analyze the plasma concentration of dexamethasone after intra-space pterygomandibular injection along with local anesthesia. The study was performed as per split mouth model where the mandibular quadrant allocation was done on a random basis considering each of the 30 patients is included in the two study interventions (SS and CS). For the study site (SS) procedures, dexamethasone was administered as a mixture (2 % lignocaine with 1:200,000 epinephrine and 4 mg dexamethasone) intra-space. In the control site (CS) procedures, a regular standard inferior alveolar nerve block was administered, and dexamethasone was given as intramuscular injection. The plasma dexamethasone determination was done in venous blood 30- and 60-min post injection using high performance liquid chromatography (HPLC). The clinical parameters like pain; swelling; and mouth opening on the first, third, and seventh post-operative day were analyzed and compared. No significant difference was found in the clinical parameters assessed; comparative evaluation showed less swelling in the SS interventions. The plasma concentration of dexamethasone for the CS interventions was 226 ± 47 ng/ml at 30-min and 316 ± 81.6 ng/ml at 60-min post injection, and for SS, it was 221 ± 81.6 ng/ml at 30-min and 340 ± 105 ng/ml at 60-min post injection. On inter-site (CS and SS) comparison, no statistically significant difference was ascertained in dexamethasone plasma concentration at 30-min post injection (P = 0.77) and at 60-min post injection. (P = 0.32). Intra-space (pterygomandibular space) administration of dexamethasone can achieve statistically similar plasma concentration

  3. Dexamethasone suppression test

    Science.gov (United States)

    DST; ACTH suppression test; Cortisol suppression test ... During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medicine. Afterward, your blood is drawn ...

  4. Emotional exhaustion and overcommitment to work are differentially associated with hypothalamus-pituitary-adrenal (HPA) axis responses to a low-dose ACTH1-24 (Synacthen) and dexamethasone-CRH test in healthy school teachers.

    Science.gov (United States)

    Wolfram, Maren; Bellingrath, Silja; Feuerhahn, Nicolas; Kudielka, Brigitte M

    2013-01-01

    Evidence for a detrimental impact of chronic work stress on health has accumulated in epidemiological research. Recent studies indicate altered hypothalamus-pituitary-adrenal (HPA) axis regulation as a possible biological pathway underlying the link between stress and disease. However, the direction of dysregulation remains unclear, with reported HPA hyper- or hyporeactivity. To disentangle potential effects on different functional levels in the HPA axis, we examined responses using two pharmacological stimulation tests in 53 healthy teachers (31 females, 22 males; mean age: 49.3 years; age range: 30-64 years): a low-dose adrenocorticotrophic hormone (ACTH(1-24), Synacthen) test was used to assess adrenal cortex sensitivity and the combined dexamethasone-corticotropin releasing hormone (DEX-CRH) test to examine pituitary and adrenal cortex reactivity. Blood and saliva samples were collected at - 1,+15,+30,+45,+60,+90,+120 min. Emotional exhaustion (EE), the core dimension of burnout, was measured with the Maslach Burnout Inventory. Overcommitment (OC) was assessed according to Siegrist's effort-reward-imbalance model. We found a significant association between EE and higher plasma cortisol profiles after Synacthen (p = 0.045). By contrast, OC was significantly associated with attenuated ACTH (p = 0.045), plasma cortisol (p = 0.005), and salivary cortisol (p = 0.023) concentrations following DEX-CRH. Results support the notion of altered HPA axis regulation in chronically work-stressed teachers, with differential patterns of hyper- and hyporeactivity depending on individual stress condition and the tested functional level of the HPA axis.

  5. Clinical applications of the sustained-release dexamethasone implant for treatment of macular edema

    Directory of Open Access Journals (Sweden)

    Rocío Herrero-Vanrell, Jose Augusto Cardillo

    2011-02-01

    Full Text Available Rocío Herrero-Vanrell1, Jose Augusto Cardillo2, Baruch D Kuppermann31Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, Complutense University, Madrid, Spain; 2Hospital de Olhos de Araraquara, Araraquara, São Paulo, Brazil; 3Gavin Herbert Eye Institute, University of California, Irvine, CA, USAAbstract: Macular edema is one of the leading causes of vision loss among patients with retinal vein occlusion, diabetic retinopathy, and posterior chamber inflammatory disease. However, the treatment of macular edema is considerably limited by the difficulty in delivering effective doses of therapeutic agents into the vitreous cavity. In recent years, the development of a sustained-release dexamethasone intravitreal implant (Ozurdex® has enabled more controlled drug release at a stable rate over a long period of time, with a potentially lower rate of adverse events. Clinical studies indicate that this dexamethasone implant is a promising new treatment option for patients with persistent macular edema resulting from retinal vein occlusion, diabetic retinopathy, and uveitis or Irvine-Gass syndrome.Keywords: diabetic retinopathy, macular edema, Ozurdex®, posterior-segment inflammatory disease, retinal vein occlusion, sustained-release dexamethasone implant

  6. Repair and dose-response at low doses

    International Nuclear Information System (INIS)

    Totter, J.R.; Weinberg, A.M.

    1977-04-01

    The DNA of each individual is subject to formation of some 2-4 x 10 14 ion pairs during the first 30 years of life from background radiation. If a single hit is sufficient to cause cancer, as is implicit in the linear, no-threshold theories, it is unclear why all individuals do not succumb to cancer, unless repair mechanisms operate to remove the damage. We describe a simple model in which the exposed population displays a distribution of repair thresholds. The dose-response at low dose is shown to depend on the shape of the threshold distribution at low thresholds. If the probability of zero threshold is zero, the response at low dose is quadratic. The model is used to resolve a longstanding discrepancy between observed incidence of leukemia at Nagasaki and the predictions of the usual linear hypothesis

  7. Effects of dexamethasone coadministered with oseltamivir on the pharmacokinetics of oseltamivir in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Jang K

    2017-03-01

    Full Text Available Kyungho Jang,1,2,* Min-Kyoung Kim,3,4,* Jaeseong Oh,1 SeungHwan Lee,1 Joo-Youn Cho,1 Kyung-Sang Yu,1 Tai Kiu Choi,3 Sang-Hyuk Lee,3,4 Kyoung Soo Lim4 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, 2Center for Clinical Pharmacology and Biomedical Research Institute, Chonbuk National University Medical School, Jeonju, 3Department of Psychiatry, 4Department of Clinical Pharmacology and Therapeutics, CHA University School of Medicine and CHA Bundang Medical Center, Seongnam, Republic of Korea *These authors contributed equally to this work Purpose: Oseltamivir is widely used in the treatment and prophylaxis of influenza A and B viral infections. It is ingested as an oral prodrug that is rapidly metabolized by carboxylesterase 1 (CES1 to its active form, oseltamivir carboxylate. Dexamethasone is also used in the treatment of acute respiratory distress syndrome, a severe complication of influenza; however, its influence on the pharmacokinetics (PK of oseltamivir is controversial. The aim of this study was to investigate the effects of coadministering oseltamivir and dexamethasone on the PK of oseltamivir in healthy volunteers. Methods: An open-label, two-period, one-sequence, multiple-dose study was conducted in 19 healthy male volunteers. Oseltamivir (75 mg was orally administered on Day 1 and Day 8, and dexamethasone (1.5 mg was administered once daily from Day 3 to Day 8. Serial blood and urine samples were collected for PK analysis of oseltamivir and oseltamivir carboxylate on Day 1 and Day 8. Oseltamivir and oseltamivir carboxylate concentrations in plasma and urine were determined using liquid chromatography–tandem mass spectrometry. Results: Area under the plasma concentration–time curve (AUC of oseltamivir and oseltamivir carboxylate decreased after dexamethasone treatment for 6 days. The geometric mean ratio (90% confidence interval of the metabolic ratio

  8. A comparison of dexamethasone, ondansetron, and dexamethasone plus ondansetron as prophylactic antiemetic and antipruritic therapy in patients receiving intrathecal morphine for major orthopedic surgery.

    LENUS (Irish Health Repository)

    Szarvas, Szilvia

    2012-02-03

    In a prospective, double-blinded, randomized trial, we evaluated the efficacy of IV (a) dexamethasone 8 mg, (b) ondansetron 8 mg, and (c) dexamethasone 8 mg plus ondansetron 4 mg for the prevention of postoperative nausea, vomiting (PONV), and pruritus in 130 (ASA physical status I to III) patients undergoing elective major orthopedic surgery after spinal anesthesia with hyperbaric 0.5% bupivacaine and intrathecal morphine. After spinal anesthesia, patients were randomized to one of three groups. Failure of PONV prophylaxis in the 24-h postoperative period occurred more frequently in patients who received dexamethasone alone (29 of 40; 73%) compared with those who received either ondansetron alone (23 of 47; 49%) (P = 0.02) or dexamethasone plus ondansetron together (19 of 43; 44%)(P = 0.01). There was no difference in the incidence of failure of prophylaxis of pruritus (70%, 72%, and 70% in dexamethasone 8 mg, ondansetron 8 mg, and dexamethasone 8 mg plus ondansetron 4 mg, respectively) (P > 0.1) in the 24-h postoperative period. We conclude that the administration of dexamethasone 8 mg with ondansetron 4 mg has no added benefit compared with ondansetron 8 mg alone in the prophylaxis of PONV and pruritus. IMPLICATIONS: Postoperative nausea and vomiting (PONV) and pruritus are common side effects after spinal opioid administration. In this study, dexamethasone 8 mg plus ondansetron 4 mg was as effective as ondansetron 8 mg. The administration of dexamethasone alone was associated with a frequent incidence of PONV, demonstrating a lack of efficacy. This has important cost implications.

  9. Re-assessment of dose from the Vinten extremity dosemeter

    International Nuclear Information System (INIS)

    O'Hagan, J.B.; Pearson, A.J.; Dutt, J.C.

    1989-01-01

    A procedure is described for re-assessing the dose from the Vinten extremity dosemeter using phototransferred thermoluminescence. The technique produces a linear response up to 50 Sv. The re-assessment efficiency is approximately 10% for the first re-assessment and 3-5% for the second re-assessment. The detection threshold values (at the 95% confidence level) are 3 mSv and 9 mSv respectively. (author)

  10. Responses of epithelial cells to low and very low doses of low let radiation

    International Nuclear Information System (INIS)

    Mothersill, Carmel; Seymour, Colin

    2003-01-01

    Recent advances in our knowledge of the biological effects of low doses of ionizing radiation have shown unexpected phenomena. These vary in the endpoint used to detect them and in the dose range examined but all occur as high-frequency events in cell populations. They include: 1. a 'bystander effect' which can be demonstrated at low doses as a transferable.factor(s) causing radiobiological effects in unexposed cells, 2. an assortment of delayed effects' occurring in progeny of cells exposed to low doses, 3. Low-dose Hypersensitivity (HRS) and Increased radioresistance (IRR) which can collectively be demonstrated as a change in the dose-effect relationship, occurring around 0.5-1 Gy of low LET radiation and 4. adaptive responses where cells exposed to very low doses followed by higher doses, exhibit an induced relatively resistant response to the second dose. In all cases, the effect of very low doses is greater than would be predicted by extrapolation of high dose data and is inconsistent with conventional DNA break/repair-based radiobiology. In practical risk assessment terms, the relative importance of the effects are high at low doses where they dominate the response, and small at high doses. This paper reviews these assorted phenomena and in particular seeks to explore whether related or distinct mechanisms underlie these various effects Understanding the mechanistic basis of these phenomena may suggest new approaches to controlling death or survival sectoring at low radiation doses. The key question is whether these low dose phenomena necessitate a new approach to risk assessment. (author)

  11. Low doses effects and gamma radiations low dose rates; Les effets des faibles doses et des faibles debits de doses de rayons gamma

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D [Institut Curie, CNRS UMR 2027, 75 - Paris (France)

    1999-07-01

    This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

  12. High-dose dexamethasone or all-trans-retinoic acid restores the balance of macrophages towards M2 in immune thrombocytopenia.

    Science.gov (United States)

    Feng, Q; Xu, M; Yu, Y Y; Hou, Y; Mi, X; Sun, Y X; Ma, S; Zuo, X Y; Shao, L L; Hou, M; Zhang, X H; Peng, J

    2017-09-01

    Essentials M1/M2 imbalance is involved in many autoimmune diseases, and could be restored. The expressions and functions of M1 and M2 were investigated in an in vitro culture system. A preferred M1 polarization is involved in the pathogenesis of immune thrombocytopenia (ITP). High-dose dexamethasone or all-trans-retinoic acid restores M1/M2 balance in ITP patients. Background Immune thrombocytopenia (ITP) is an autoimmune disorder. Deficiency of immune tolerance in antigen-presenting cells and cross-communication between antigen-presenting cells and T cells are involved in the pathogenesis of ITP. Macrophages can polarize into proinflammatory M1 or anti-inflammatory M2 phenotypes in response to different environmental stimuli, and have diverse immunologic functions. Objectives To investigate the M1/M2 imbalance in ITP and whether high-dose dexamethasone (HD-DXM) or all-trans-retinoic acid (ATRA) could restore this imbalance. Methods The numbers of M1 and M2 macrophages in the spleens of ITP patients and patients with traumatic spleen rupture were analyzed by immunofluorescence. Monocyte-derived macrophages were cultured and induced with cytokines and drugs. The expression of M1 and M2 markers and functions of M1 and M2 macrophages before and after modulation by HD-DXM or ATRA were evaluated with flow cytometry and ELISA. Results There was preferred M1 polarization in ITP spleens as compared with healthy controls. Monocyte-derived macrophages from ITP patients had increased expression of M1 markers and impaired immunosuppressive functions. Either HD-DXM or ATRA corrected this imbalance by decreasing the expression of M1 markers and increasing the expression of M2 markers. Moreover, HD-DXM-modulated or ATRA-modulated macrophages suppressed both CD4 + and CD8 + T-cell proliferation and expanded CD4 + CD49 + LAG3 + type 1 T-regulatory cells. HD-DXM or ATRA modulated macrophages to shift the T-cell cytokine profile towards Th2. Treating patients with HD-DXM or ATRA

  13. Low and very low doses, new recommendations?

    International Nuclear Information System (INIS)

    Foucher, N.

    1999-01-01

    The topic of the seminar organized by the world council of nuclear workers (WONUC) was the effects of low or very low doses on human health. Discussions centred round the linearity of the relation between dose and effect in the evaluation and management of the health hazard. The recommendations proposed by ICPR (international commission for radiological protection) are based on this linearity as a precaution. On the one hand it is remembered that low dose irradiation might be beneficial. It has been proved that the irradiation of the whole body is efficient in case of Hodgkin lymphoma. On the other hand it is remembered that doses as low as 10 mSv in utero have led to an excess of cancer in children. Studies based on experimentally radio-induced cancers have been carried out in Japan, China, Canada and France.Their results seem to be not consistent with the hypothesis of linearity. During the last decade a lot of work has been made but a conclusion is far to be reached, it is said that the American department of energy (DOE) has invited bids in 1999 to launch research programs in order to clarify the situation. (A.C.)

  14. Intraperitoneal Dexamethasone As A New Method for Relieving Postoperative Shoulder Pain after Gynecologic Laparoscopy

    Directory of Open Access Journals (Sweden)

    Zahra Asgari

    2012-01-01

    Full Text Available Background: In this study, we tried to show the efficacy of Intraperitoneal dexamethasoneon relieving shoulder pain after gynecologic laparoscopy.Materials and Methods: In this double-blind randomized clinical trial, 63 patients who werecandidates for gynecologic laparoscopy were included. At the end of the procedure patientsrandomly received 16 mg dexamethasone (n=31 or placebo (n=32 intraperitoneally. Visualanalogue scale (VAS was used for clinical evaluation of pain severity during 24 hours afterlaparoscopy . A physician, who was not aware whether patients were treated with drug or placebo,evaluated the patients.Results: The severity of pain in the dexamethasone group within 0, 2, 4, 8, 12, 24 hoursafter procedure was significantly less than in the placebo group (p<0.001. The averageconsumption of opioids as analgesic/ sedative in the placebo group was more than thedexamethasone group (p=0.025.Conclusion: Findings of this study show that the prescription of 16 mg of dexamethasone(single dose in the peritoneal cavity may significantly reduce the severity of painafter Laparoscopy in comparison with placebo and may decrease the need for narcoticsas pain relief (Registration Number: IRCT201105306640N1.

  15. Effects of low-dose irradiation of X-rays on IUdR incorporation into mouse tissues

    International Nuclear Information System (INIS)

    Misonoh, J.; Ishii, K.; Yoshida, M.; Okumura, Y.; Kodama, S.

    1992-01-01

    It is well known that biological responses get smaller when a radiation dose gets lower, and it makes it difficult to detect them with significant differences from background levels. Therefore we know little about biological effects arisen from very low-dose radiation in mammals and mammalian cells. Feinendegen et al. detected a significant reduction of 125 I-UdR uptake in bone marrow cells at doses below 0.01 Gy. Using this extremely sensitive biological response, they also indicated that cells of mice irradiated twice with an interval of 4 hours did not show any reaction after the second irradiation. This meant that cells became radio-resistant after whole-body irradiation with low-doses. This phenomenon, an acquired radio-resistance after low-dose irradiation, is explained as an adaptive response to radiation , which is recently well documented in cytogenic studies. In order to confirm that whether it is common in the cell renewal systems, IUdR incorporation into mouse spleen and the other tissues were studied after whole-body irradiation. (author). 7 refs., 1 fig., 2 tabs

  16. Ameliorative effects of low dose/low dose-rate irradiation on reactive oxygen species-related diseases model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu

    2008-01-01

    Living organisms have developed complex biological system which protects themselves against environmental radiation, and irradiation with proper dose, dose-rate and irradiation time can stimulate their biological responses against oxidative stress evoked by the irradiation. Because reactive oxygen species are involved in various human diseases, non-toxic low dose/low dose-rate radiation can be utilized for the amelioration of such diseases. In this study, we used mouse experimental models for fatty liver, nephritis, diabetes, and ageing to elucidate the ameliorative effect of low dose/low dose-rate radiation in relation to endogenous antioxidant activity. Single irradiation at 0.5 Gy ameliorates carbon tetrachloride-induced fatty liver. The irradiation increases hepatic anti-oxidative system involving glutathione and glutathione peroxidase, suggesting that endogenous radical scavenger is essential for the ameliorative effect of low dose radiation on carbon tetrachloride-induced fatty liver. Single irradiation at 0.5 Gy ameliorates ferric nitrilotriacetate-induced nephritis. The irradiation increases catalase and decreases superoxide dismutase in kidney. The result suggests that low dose radiation reduced generation of hydroxide radical generation by reducing cellular hydroperoxide level. Single irradiation at 0.5 Gy at 12 week of age ameliorates incidence of type I diabetes in non-obese diabetic (NOD) mice through the suppression of inflammatory activity of splenocytes, and resultant apoptosis of β-cells in pancreas. The irradiation activities of superoxide dismutase and catalase, which coordinately diminish intracellular reactive oxygen species. Continuous irradiation at 0.70 mGy/hr from 10 week of age elongates life span, and suppresses alopecia in type II diabetesmice. The irradiation improved glucose clearance without affecting insulin-resistance, and increased pancreatic catalase activity. The results suggest that continuous low dose-rate irradiation protect

  17. Grain dust induces IL-8 production from bronchial epithelial cells: the effect of dexamethasone on IL-8 production.

    Science.gov (United States)

    Park, H S; Suh, J H; Kim, H Y; Kwon, O J; Choi, D C

    1999-04-01

    Recent publications have suggested an active participation of neutrophils to induce bronchoconstriction after inhalation of grain dust (GD). To further understand the role of neutrophils in the pathogenesis of GD-induced asthma, this investigation was designed to determine whether human bronchial epithelial cells could produce IL-8 production and to observe the effect of dexamethasone on IL-8 production. We cultured Beas-2B, a bronchial epithelial cell line. To observe GD-induced responses, four concentrations (1 to 200 microg/mL) of GD were incubated for 24 hours and compared with those without incubation of GD. To evaluate the effect of pro-inflammatory cytokines on IL-8 production, epithelial cells were incubated with peripheral blood mononuclear cell (PBMC) culture supernatant, which was derived from the culture of PBMC from a GD-induced asthmatic subject under the exposure to 10 microg/mL of GD, and compared with those cultured without addition of PBMC supernatant. The level of released IL-8 in the supernatant was measured by enzyme-linked immunosorbent assay. To evaluate the effect of dexamethasone on IL-8 production, four concentrations (5 to 5000 ng/mL) of dexamethasone were pre-incubated for 24 hours and the same experiments were repeated. There was significant production of IL-8 from bronchial epithelial cells with additions of GD in a dose-dependent manner (P < .05), which was significantly augmented with additions of PBMC supernatant (P < .05) at each concentration. Compared with the untreated sample, pretreatment of dexamethasone could induced a remarkable inhibitions (15% to 55%) of IL-8 production from bronchial epithelial cells in a dose-dependent manner. These results suggest that IL-8 production from bronchial epithelial cells may contribute to neutrophil recruitment occurring in GD-induced airway inflammation. The downregulation of IL-8 production by dexamethasone from bronchial epithelial cells may contribute to the efficacy of this compound in

  18. Low Dose Suppression of Neoplastic Transformation in Vitro

    Energy Technology Data Exchange (ETDEWEB)

    John Leslie Redpath

    2012-05-01

    This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

  19. Post-operative high dose rate brachytherapy in patients with low to intermediate risk endometrial cancer

    International Nuclear Information System (INIS)

    Pearcey, R.G.; Petereit, D.G.

    2000-01-01

    This paper investigates the outcome using different dose/fractionation schedules in high dose rate (HDR) post-operative vaginal vault radiotherapy in patients with low to intermediate risk endometrial cancer. The world literature was reviewed and thirteen series were analyzed representing 1800 cases. A total of 12 vaginal vault recurrences were identified representing an overall vaginal control rate of 99.3%. A wide range of dose fractionation schedules and techniques have been reported. In order to analyze a dose response relationship for tumor control and complications, the biologically effective doses to the tumor and late responding tissues were calculated using the linear quadratic model. A threshold was identified for complications, but not vaginal control. While dose fractionation schedules that delivered a biologically effective dose to the late responding tissues in excess of 100 Gy 3 (LQED = 60 Gy) predicted for late complications, dose fractionation schedules that delivered a modest dose to the vaginal surface (50 Gy 10 or LQED = 30 Gy) appeared tumoricidal with vaginal control rates of at least 98%. By using convenient, modest dose fractionation schedules, HDR vaginal vault - brachytherapy yields very high local control and extremely low morbidity rates. (author)

  20. Effects of dexamethasone on brain edema

    International Nuclear Information System (INIS)

    Takemoto, Motohisa

    1982-01-01

    Experimental cerebral edema was produced on the right parietal lobe of Wistar male rats with a cold metal probe cooled by liquid nitrogen. Twenty hour later, 3 H-dexamethasone was either intramuscularly or intravenously injected into rats, estimated in the brain tissue by the liquid scintillation counting method. Edematous brain generally contained much higher 3 H-activity than the control. Furthermore, I.V. injection showed higher 3 H-activity than I.M injection in edematous and control brains at all times. For examination of the subcellular distribution of 3 H-dexamethasone in edematous brain, 3 H-activity was most strongly detected in the supernatant fraction (63%), followed by the heavy mitochondrial fraction (25.4%) and the nuclear fraction (8.4%). Although edematous brain tissue constantly demonstrated higher 3 H-activity than the control, its supernatant fraction conversely had less activity. As a next step, distribution of 3 H-dexamethasone in the supernatant fraction was studies. The result was that the high molecular weight fraction in the edematous brain showed higher radioactivity than the control. From these findings, unequivocal distribution of dexamethasone in the supernatant fraction of edematous brain tissue could be correlated with its biochemical action for preventing brain edema. (J.P.N.)

  1. Multidisciplinary European Low Dose Initiative (MELODI). Strategic research agenda for low dose radiation risk research

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzer, M. [Federal Office for Radiation Protection, BfS, Department of Radiation Protection and Health, Neuherberg (Germany); Auvinen, A. [University of Tampere, Tampere (Finland); STUK, Helsinki (Finland); Cardis, E. [ISGlobal, Barcelona Institute for Global Health, Barcelona (Spain); Durante, M. [Institute for Fundamental Physics and Applications, TIFPA, Trento (Italy); Harms-Ringdahl, M. [Stockholm University, Centre for Radiation Protection Research, Stockholm (Sweden); Jourdain, J.R. [Institute for Radiological Protection and Nuclear Safety, IRSN, Fontenay-aux-roses (France); Madas, B.G. [MTA Centre for Energy Research, Environmental Physics Department, Budapest (Hungary); Ottolenghi, A. [University of Pavia, Physics Department, Pavia (Italy); Pazzaglia, S. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome (Italy); Prise, K.M. [Queens University Belfast, Belfast (United Kingdom); Quintens, R. [Belgian Nuclear Research Centre, SCK-CEN, Mol (Belgium); Sabatier, L. [French Atomic Energy Commission, CEA, Paris (France); Bouffler, S. [Public Health England, PHE, Chilton (United Kingdom)

    2018-03-15

    MELODI (Multidisciplinary European Low Dose Initiative) is a European radiation protection research platform with focus on research on health risks after exposure to low-dose ionising radiation. It was founded in 2010 and currently includes 44 members from 18 countries. A major activity of MELODI is the continuous development of a long-term European Strategic Research Agenda (SRA) on low-dose risk for radiation protection. The SRA is intended to identify priorities for national and European radiation protection research programs as a basis for the preparation of competitive calls at the European level. Among those key priorities is the improvement of health risk estimates for exposures close to the dose limits for workers and to reference levels for the population in emergency situations. Another activity of MELODI is to ensure the availability of European key infrastructures for research activities, and the long-term maintenance of competences in radiation research via an integrated European approach for training and education. The MELODI SRA identifies three key research topics in low dose or low dose-rate radiation risk research: (1) dose and dose rate dependence of cancer risk, (2) radiation-induced non-cancer effects and (3) individual radiation sensitivity. The research required to improve the evidence base for each of the three key topics relates to three research lines: (1) research to improve understanding of the mechanisms contributing to radiogenic diseases, (2) epidemiological research to improve health risk evaluation of radiation exposure and (3) research to address the effects and risks associated with internal exposures, differing radiation qualities and inhomogeneous exposures. The full SRA and associated documents can be downloaded from the MELODI website (http://www.melodi-online.eu/sra.html). (orig.)

  2. Does dexamethasone have a perineural mechanism of action?

    DEFF Research Database (Denmark)

    Jæger, P; Grevstad, Jens Ulrik; Koscielniak-Nielsen, Z J

    2016-01-01

    BACKGROUND: Dexamethasone prolongs block duration. Whether this is achieved via a peripheral or a central mechanism of action is unknown. We hypothesized that perineural dexamethasone added as an adjuvant to ropivacaine prolongs block duration compared with ropivacaine alone, by a locally mediated...... effect when controlled for a systemic action. METHODS: We performed a paired, blinded, randomized trial, including healthy men. All subjects received bilateral blocks of the saphenous nerve with ropivacaine 0.5%, 20 ml mixed with dexamethasone 2 mg in one leg and saline in the other, according...

  3. High dose rate brachytherapy for the treatment of soft tissue sarcoma of the extremity

    International Nuclear Information System (INIS)

    Speight, J.L.; Streeter, O.E.; Chawla, S.; Menendez, L.E.

    1996-01-01

    Purpose: we examined the role of preoperative neoadjuvant chemoradiation and adjuvant high-dose rate brachytherapy on the management of prognostically unfavorable soft tissue sarcomas of the extremities. Our goal was to examine the effect of high dose rate interstitial brachytherapy (HDR IBT) on reducing the risk of local recurrence following limb-sparing resection, as well as shortening treatment duration. Materials and methods: eleven patients, ranging in age from 31 to 73 years old, with soft tissue sarcoma of the extremity were treated at USC/Norris Comprehensive Cancer Center during 1994 and 1995. All patients had biopsy proven soft tissue sarcoma, and all were suitable candidates for limb-sparing surgery. All lesions were greater than 5cm in size and were primarily high grade. Tumor histologies included malignant fibrous histiocytoma (45%), liposarcoma (18%) and leiomyosarcoma, synovial cell sarcoma and spindle cell sarcoma (36%). Sites of tumor origin were the lower extremity (55%), upper extremity (18%) and buttock (9%), 1 patient (9%) had lesions in both the upper and lower extremity. Patients received HDR IBT following combined chemotherapy and external beam irradiation (EBRT) and en bloc resection of the sarcoma. Neoadjuvant chemotherapy consisted of three to four cycles of either Ifosfamide/Mesna with or without Adriamycin, or Mesna, Adriamycin, Ifosfamide and Dacarbazine. One patient received Cis-platin in addition to Ifos/Adr. A minimum of two cycles of chemotherapy were administered prior to EBRT. Additional cycles of chemotherapy were completed concurrently with EBRT but prior to HDR IBT. Preoperative EBRT doses ranging from 40 to 59.4 Gy were given in daily fractions of 180 to 200cGy. Following en bloc resection, HDR IBT was administered using the Omnitron tm 2000 remote afterloading system. Doses ranging from 13 to 30 Gy were delivered to the surgical tumor bed at depths of 0.5mm to 0.75mm from the radioactive source. Results: median follow-up was

  4. Analgesic effects of dexamethasone in burn injury

    DEFF Research Database (Denmark)

    Werner, Mads U; Lassen, Birgit Vibeke; Kehlet, Henrik

    2002-01-01

    and secondary hyperalgesia. RESULTS: The burn injury induced significant increases in erythema (P burn did not differ between dexamethasone and placebo treatments (P >.6). There were no significant......BACKGROUND AND OBJECTIVES: Glucocorticoids are well-known adjuvant analgesics in certain chronic pain states. There is, however, a paucity of data on their analgesic efficacy in acute pain. Therefore, the aim of the study was to examine the analgesic effects of dexamethasone in a validated burn...... model of acute inflammatory pain in humans. METHODS: Twenty-two volunteers were investigated in a double-blind, randomized, placebo-controlled cross-over study. Intravenous dexamethasone 8 mg or placebo was administered on 2 separate study days. Two hours after drug administration, a first-degree burn...

  5. Effect of low-level laser therapy on tissue repair after dental extraction in rats administered zoledronic acid and dexamethasone

    Science.gov (United States)

    Weber, João Batista Blessmann; Camilotti, Renata Stifelman; Jasper, Juliana; Casagrande, Liliane Cristina Onofre; Maito, Fábio Luiz Dal Moro

    2017-05-01

    Bisphosphonates (BPs) are being increasingly used for the treatment of metabolic and oncological pathologies involving the skeletal system. Because of the severity of the BP associated osteonecrosis of the jaws, the difficulties of treatment, and patient discomfort, additional support methods for their management are needed. Laser therapy has an easy handling, photobiostimulator effect on tissues healing, so it can be considered a preferred therapy. The aim of this study was to evaluate the influence of low-level laser therapy in the 685- and 830-nm wavelength in the healing process of the bone and soft tissues in rats under BP therapy [zoledronic acid (ZA)] and dexamethasone concomitantly that underwent a surgery for the extraction of upper molars. There were statistically significant differences in the clinical evaluation of the wound and the weight of the animals. Regarding the histological evaluation, it was possible to observe the different maturations of the healing stage between groups. The effect of drug therapy with ZA and dexamethasone in the bone tissue repair process induces osteonecrosis of the jaw in rats and slows down the healing process. In the laser groups, at the stipulated dosimetry, a positive influence on the bone and soft tissue repair process was observed.

  6. A single dose of dexamethasone encapsulated in polyethylene glycol-coated polylactic acid nanoparticles attenuates cisplatin-induced hearing loss following round window membrane administration

    Directory of Open Access Journals (Sweden)

    Sun CL

    2015-05-01

    Full Text Available Changling Sun,1,3,* Xueling Wang,1,* Zhaozhu Zheng,2 Dongye Chen,1 Xiaoqin Wang,2 Fuxin Shi,1 Dehong Yu,1 Hao Wu11Department of Otolaryngology–Head and Neck Surgery, Xinhua Hospital, Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, 2National Engineering Laboratory for Modern Silk, Soochow University, Suzhou, 3Department of Otolaryngology–Head and Neck Surgery, Affiliated Hospital of Jiangnan University, The Fourth People’s Hospital of Wuxi City, Wuxi, People’s Republic of China*These authors have contributed equally to this workAbstract: This study aimed to investigate the sustained drug release properties and hearing protection effect of polyethylene glycol-coated polylactic acid (PEG-PLA stealth nanoparticles loaded with dexamethasone (DEX. DEX was fabricated into PEG-PLA nanoparticles using an emulsion and evaporation technique, as previously reported. The DEX-loaded PEG-PLA nanoparticles (DEX-NPs had a hydrodynamic diameter of 130±4.78 nm, and a zeta potential of -26.13±3.28 mV. The in vitro release of DEX from DEX-NPs lasted 24 days in phosphate buffered saline (pH 7.4, 5 days in artificial perilymph (pH 7.4, and 1 day in rat plasma. Coumarin 6-labeled NPs placed onto the round window membrane (RWM of guinea pigs penetrated RWM quickly and accumulated to the organs of Corti, stria vascularis, and spiral ganglion cells after 1 hour of administration. The DEX-NPs locally applied onto the RWM of guinea pigs by a single-dose administration continuously released DEX in 48 hours, which was significantly longer than the free DEX that was cleared out within 12 hours after administration at the same dose. Further functional studies showed that locally administrated single-dose DEX-NPs effectively preserved outer hair cells in guinea pigs after cisplatin insult and thus significantly attenuated hearing loss at 4 kHz and 8

  7. Carcinogenesis induced by low-dose radiation

    Directory of Open Access Journals (Sweden)

    Piotrowski Igor

    2017-11-01

    Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

  8. Low-dose x-radiation and congenital anomalies

    International Nuclear Information System (INIS)

    Kameyama, Yoshiro

    1983-01-01

    Among radiation effects on developing embryos and fetuses, occurrence of germinal mutation due to exposure of the gonads and postnatal manifestation of neoplasms are considered to be stochastic effects from the aspect of radiation protection. On the other hand, somatic effects such as teratogenic and embryo-toxic effects can be regarded as nonstochastic ones with threshold doses. In experimental teratological studies with mice and rats, the lowest radiation doses for manifestation of the non-stochastic somatic effects which have been recognized so far are:5 rad for resorption of preimplantation embryos; 5-10 rad for acute cytological changes such as pyknosis, cytoplasmic degeneration and mitotic delay; 5 rad for increasing frequency of spontaneous minor anomalies of the skeleton; 15-20 rad for malformations of the eye, brain and spinal cord; 20-25 rad for histogenetic and functional disorders of the central nervous system; and 20-25 rad for impaired fertility. Pregnant women who are subject to X-ray examinations are much concerned about potential hazard of radiation to their offspring in utero. The above experimental findings suggest that the possibility of non-stochastic somatic effects of diagnostic radiation on human embryos and fetuses is extremely low, and probably negligible, given the proper dose control measures. Possible effects which should be considered for risk evaluation of diagnostic exposure are two stochastic effects, carcinogenic and mutagenic. (author)

  9. Effects of dexamethasone on palate mesenchymal cell phospholipase activity

    International Nuclear Information System (INIS)

    Bulleit, R.F.; Zimmerman, E.F.

    1984-01-01

    Corticosteroids will induce cleft palate in mice. One suggested mechanism for this effect is through inhibition of phospholipase activity. This hypothesis was tested by measuring the effects of dexamethasone, a synthetic corticosteroid, on phospholipase activity in cultures of palate mesenchymal cells. Palate mesenchymal cells were prelabeled with [3H]arachidonic acid. The cells were subsequently treated with various concentrations of dexamethasone. Concurrently, cultures of M-MSV-transformed 3T3 cells were prepared identically. After treatment, phospholipase activity was stimulated by the addition of serum or epidermal growth factor (EGF), and radioactivity released into the medium was taken as a measure of phospholipase activity. Dexamethasone (1 X 10(-5) or 1 X 10(-4) M) could inhibit serum-stimulated phospholipase activity in transformed 3T3 cells after 1 to 24 hr of treatment. However, no inhibition of activity was measured in palate mesenchymal cells following this period of treatment. Not until 120 hr of treatment with dexamethasone (1 X 10(-4) M) was any significant inhibition of serum-stimulated phospholipase activity observed in palate mesenchymal cells. When EGF was used to stimulate phospholipase activity, dexamethasone (1 X 10(-5) M) caused an increase in phospholipase activity in palate mesenchymal cells. These observations suggested that phospholipase in transformed 3T3 cells was sensitive to inhibition by dexamethasone. However, palate mesenchymal cell phospholipase is only minimally sensitive to dexamethasone, and in certain instances can be enhanced. These results cannot support the hypothesis that corticosteroids mediate their teratogenic effect via inhibition of phospholipase activity

  10. Biological responses to low dose rate gamma radiation

    International Nuclear Information System (INIS)

    Magae, Junji; Ogata, Hiromitsu

    2003-01-01

    Linear non-threshold (LNT) theory is a basic theory for radioprotection. While LNT dose not consider irradiation time or dose-rate, biological responses to radiation are complex processes dependent on irradiation time as well as total dose. Moreover, experimental and epidemiological studies that can evaluate LNT at low dose/low dose-rate are not sufficiently accumulated. Here we analyzed quantitative relationship among dose, dose-rate and irradiation time using chromosomal breakage and proliferation inhibition of human cells as indicators of biological responses. We also acquired quantitative data at low doses that can evaluate adaptability of LNT with statistically sufficient accuracy. Our results demonstrate that biological responses at low dose-rate are remarkably affected by exposure time, and they are dependent on dose-rate rather than total dose in long-term irradiation. We also found that change of biological responses at low dose was not linearly correlated to dose. These results suggest that it is necessary for us to create a new model which sufficiently includes dose-rate effect and correctly fits of actual experimental and epidemiological results to evaluate risk of radiation at low dose/low dose-rate. (author)

  11. Effects of low doses

    International Nuclear Information System (INIS)

    Le Guen, B.

    2001-01-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  12. Does Growth Impairment Underlie the Adverse Effects of Dexamethasone on Development of Noradrenergic Systems?

    Science.gov (United States)

    Slotkin, Theodore A; Ko, Ashley; Seidler, Frederic J

    2018-06-20

    Glucocorticoids are given in preterm labor to prevent respiratory distress but these agents evoke neurobehavioral deficits in association with reduced brain region volumes. To determine whether the neurodevelopmental effects are distinct from growth impairment, we gave developing rats dexamethasone at doses below or within the therapeutic range (0.05, 0.2 or 0.8 mg/kg) at different stages: gestational days (GD) 17-19, postnatal days (PN) 1-3 or PN7-9. In adolescence and adulthood, we assessed the impact on noradrenergic systems in multiple brain regions, comparing the effects to those on somatic growth or on brain region growth. Somatic growth was reduced with exposure in all three stages, with greater sensitivity for the postnatal regimens; brain region growth was impaired to a lesser extent. Norepinephrine content and concentration were reduced depending on the treatment regimen, with a rank order of deficits of PN7-9 > PN1-3 > GD17-19. However, brain growth impairment did not parallel reduced norepinephrine content in magnitude, dose threshold, sex or regional selectivity, or temporal pattern, and even when corrected for reduced brain region weights (norepinephrine per g tissue), the dexamethasone-exposed animals showed subnormal values. Regression analysis showed that somatic growth impairment accounted for an insubstantial amount of the reduction in norepinephrine content, and brain growth impairment accounted for only 12%, whereas specific effects on norepinephrine accounted for most of the effect. The adverse effects of dexamethasone on noradrenergic system development are not simply related to impaired somatic or brain region growth, but rather include specific targeting of neurodifferentiation. Copyright © 2018. Published by Elsevier B.V.

  13. Phase 1/2 study of cyclin-dependent kinase (CDK)4/6 inhibitor palbociclib (PD-0332991) with bortezomib and dexamethasone in relapsed/refractory multiple myeloma.

    Science.gov (United States)

    Niesvizky, Ruben; Badros, Ashraf Z; Costa, Luciano J; Ely, Scott A; Singhal, Seema B; Stadtmauer, Edward A; Haideri, Nisreen A; Yacoub, Abdulraheem; Hess, Georg; Lentzsch, Suzanne; Spicka, Ivan; Chanan-Khan, Asher A; Raab, Marc S; Tarantolo, Stefano; Vij, Ravi; Zonder, Jeffrey A; Huang, Xiangao; Jayabalan, David; Di Liberto, Maurizio; Huang, Xin; Jiang, Yuqiu; Kim, Sindy T; Randolph, Sophia; Chen-Kiang, Selina

    2015-01-01

    This phase 1/2 study was the first to evaluate the safety and efficacy of the cyclin-dependent kinase (CDK) 4/6-specific inhibitor palbociclib (PD-0332991) in sequential combination with bortezomib and dexamethasone in relapsed/refractory multiple myeloma. The recommended phase 2 dose was palbociclib 100 mg orally once daily on days 1-12 of a 21-day cycle with bortezomib 1.0 mg/m2 (intravenous) and dexamethasone 20 mg (orally 30 min pre-bortezomib dosing) on days 8 and 11 (early G1 arrest) and days 15 and 18 (cell cycle resumed). Dose-limiting toxicities were primarily cytopenias; most other treatment-related adverse events were grade≤3. At a bortezomib dose lower than that in other combination therapy studies, antitumor activity was observed (phase 1). In phase 2, objective responses were achieved in 5 (20%) patients; 11 (44%) achieved stable disease. Biomarker and pharmacodynamic assessments demonstrated that palbociclib inhibited CDK4/6 and the cell cycle initially in most patients.

  14. Dose rate effect on low-dose hyper-radiosensitivity with cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon-Min; Kim, Eun-Hee [Seoul National University, Seoul (Korea, Republic of)

    2016-10-15

    Low-dose hyper-radiosensitivity (HRS) is the phenomenon that mammalian cells exhibit higher sensitivity to radiation at low doses (< 0.5 Gy) than expected by the linear-quadratic model. At doses above 0.5Gy, the cellular response is recovered to the level expected by the linear-quadratic model. This transition is called the increased radio-resistance (IRR). HRS was first verified using Chinese hamster V79 cells in vitro by Marples and has been confirmed in studies with other cell lines including human normal and tumor cells. HRS is known to be induced by inactivation of ataxia telangiectasia-mutated (ATM), which plays a key role in repairing DNA damages. Considering the connection between ATM and HRS, one can infer that dose rate may affect cellular response regarding HRS at low doses. In this study, we quantitated the effect of dose rate on HRS by clonogenic assay with normal and tumor cells. The HRS of cells at low dose exposures is a phenomenon already known. In this study, we observed HRS of rat normal diencephalon cells and rat gliosarcoma cells at doses below 1 Gy. In addition, we found that dose rate mattered. HRS occurred at low doses, but only when total dose was delivered at a rate below certain level.

  15. The Comparison of Two Types of Treatment (High Dose and Low Dose IVIG in Children with GBS in Mofid Hospital

    Directory of Open Access Journals (Sweden)

    Parvaneh Karim-Zadeh

    2003-12-01

    Full Text Available Objective: Acute inflammatory demyelinating peripheral neuropathy (Guillain-Barre-Syndrome is by far the most common cause of immune–mediated peripheral nerve disease in children and with the near disappearance of poliomyelitis, is responsible for the great majority of cases of acute flaccid paralysis. Several controlled studies have done with corticosteroids, plasma pheresis and IVIG in pediatric patients. IVIG treatment can be done in two types of treatment: 1- High dose that means 1gr/kg/day for 2 days. 2- Low dose that means 400mg/kg/day for 5 days. Several studies in other countries have shown faster rate of recovery in patients who received total dose of IVIG in 2 days as opposed to 5 days. Materials & Methods: Because we have not any study about this two types of treatment in IRAN we decided to comparison this two types of IVIG treatment. So the patients that referred to Mofid children hospital for weakness and we diagnosed GBS (with history, physical examination, laboratories and EMG-NCV are divided in two groups: 1- High dose IVIG treatment (experimental group. 2- Low dose IVIG treatment (control group Then the results evaluated. Results: Our findings included that in high dose IVIG therapy we have faster rate of recovery and the Hospital stay is shorter than low dose IVIG-therapy. Also in this type of treatment “because the patients cure faster” , so complications are decreased in them. In the group of high dose IVIG therapy, lower and upper extremities weakness decreased in time. Conclusion: We did not receive any relationship between side effects of drugs and the type of treatment. The relationship between high dose IVIG therapy and drug side effects was not significant.

  16. Mammography-oncogenecity at low doses

    International Nuclear Information System (INIS)

    Heyes, G J; Mill, A J; Charles, M W

    2009-01-01

    Controversy exists regarding the biological effectiveness of low energy x-rays used for mammography breast screening. Recent radiobiology studies have provided compelling evidence that these low energy x-rays may be 4.42 ± 2.02 times more effective in causing mutational damage than higher energy x-rays. These data include a study involving in vitro irradiation of a human cell line using a mammography x-ray source and a high energy source which matches the spectrum of radiation observed in survivors from the Hiroshima atomic bomb. Current radiation risk estimates rely heavily on data from the atomic bomb survivors, and a direct comparison between the diagnostic energies used in the UK breast screening programme and those used for risk estimates can now be made. Evidence highlighting the increase in relative biological effectiveness (RBE) of mammography x-rays to a range of x-ray energies implies that the risks of radiation-induced breast cancers for mammography x-rays are potentially underestimated by a factor of four. A pooled analysis of three measurements gives a maximal RBE (for malignant transformation of human cells in vitro) of 4.02 ± 0.72 for 29 kVp (peak accelerating voltage) x-rays compared to high energy electrons and higher energy x-rays. For the majority of women in the UK NHS breast screening programme, it is shown that the benefit safely exceeds the risk of possible cancer induction even when this higher biological effectiveness factor is applied. The risk/benefit analysis, however, implies the need for caution for women screened under the age of 50, and particularly for those with a family history (and therefore a likely genetic susceptibility) of breast cancer. In vitro radiobiological data are generally acquired at high doses, and there are different extrapolation mechanisms to the low doses seen clinically. Recent low dose in vitro data have indicated a potential suppressive effect at very low dose rates and doses. Whilst mammography is a low

  17. Dexamethasone enhances the anti-emetic effect of metoclopramide ...

    African Journals Online (AJOL)

    Ninety patients, ASA I or II, aged 21-64years were randomly selected to either the dexamethasone-metoclopramide group, metoclopramide group or dexamethasone group using computer-generated random numbers . Spinal anaesthesia was induced in the sitting position under strict aseptic technique with hyperbaric ...

  18. Low-dose electron energy-loss spectroscopy using electron counting direct detectors.

    Science.gov (United States)

    Maigné, Alan; Wolf, Matthias

    2018-03-01

    Since the development of parallel electron energy loss spectroscopy (EELS), charge-coupled devices (CCDs) have been the default detectors for EELS. With the recent development of electron-counting direct-detection cameras, micrographs can be acquired under very low electron doses at significantly improved signal-to-noise ratio. In spectroscopy, in particular in combination with a monochromator, the signal can be extremely weak and the detection limit is principally defined by noise introduced by the detector. Here we report the use of an electron-counting direct-detection camera for EEL spectroscopy. We studied the oxygen K edge of amorphous ice and obtained a signal noise ratio up to 10 times higher than with a conventional CCD.We report the application of electron counting to record time-resolved EEL spectra of a biological protein embedded in amorphous ice, revealing chemical changes observed in situ while exposed by the electron beam. A change in the fine structure of nitrogen K and the carbon K edges were recorded during irradiation. A concentration of 3 at% nitrogen was detected with a total electron dose of only 1.7 e-/Å2, extending the boundaries of EELS signal detection at low electron doses.

  19. Effects of low doses; Effet des faibles doses

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, B. [Electricite de France (EDF-LAM-SCAST), 93 - Saint-Denis (France)

    2001-07-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  20. Extremely Low-Metallicity Stars in the Classical Dwarf Galaxies

    NARCIS (Netherlands)

    Starkenburg, E.; DART Team, [Unknown; Aoki, W; Ishigaki, M; Suda, T; Tsujimoto, T; Arimoto, N

    After careful re-analysis of Ca II triplet calibration at low-metallicity, the classical satellites around the Milky Way are found not to be devoided of extremely low-metallicity stars and their (extremely) metal-poor tails are predicted to be much more in agreement with the Milky Way halo. A first

  1. Effects of low dose rate irradiation on life span prolongation of human premature-aging syndrome model mice

    International Nuclear Information System (INIS)

    Nomura, Takaharu

    2006-01-01

    We previously showed that Type II diabetes model mice prolonged of their life span by life long low dose rate irradiation. We also found that antioxidant function in variety tissues of some strain of mice were enhancement after low dose/low dose rate irradiation. The prolongation of life span might depend on certain damaged level of reactive oxygen species. We thought the effect of the prolongation was due to the enhancement of the antioxidant activities after irradiation. We investigated whether the enhancement of antioxidant activities after low dose rate irradiation had an effect on life span prolongation. Four-week-old female human premature-aging syndrome model mice, kl/kl (klotho) mice, which the life span of this model mouse is about 65 days, were irradiated with gamma rays at 0.35, 0.70 or 1.2 mGy/hr. The 0.70 mGy/hr-irradiated group remarkably effected on the prolongation of their life span. Some mice of the group were extremely survived for about and more 100 days. Antioxidant activities in the irradiated groups were enhancement by low dose rate irradiation, however the dependence of the dose rates were not clearly difference. These results suggest that the antioxidant activities in this model mouse were enhanced by the low dose rate irradiation, and may make it possible to prolong the life span of this mouse. (author)

  2. Low-dose computed tomography image restoration using previous normal-dose scan

    International Nuclear Information System (INIS)

    Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

    2011-01-01

    Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use

  3. Extreme Low Frequency Acoustic Measurement System

    Science.gov (United States)

    Shams, Qamar A. (Inventor); Zuckerwar, Allan J. (Inventor)

    2017-01-01

    The present invention is an extremely low frequency (ELF) microphone and acoustic measurement system capable of infrasound detection in a portable and easily deployable form factor. In one embodiment of the invention, an extremely low frequency electret microphone comprises a membrane, a backplate, and a backchamber. The backchamber is sealed to allow substantially no air exchange between the backchamber and outside the microphone. Compliance of the membrane may be less than ambient air compliance. The backplate may define a plurality of holes and a slot may be defined between an outer diameter of the backplate and an inner wall of the microphone. The locations and sizes of the holes, the size of the slot, and the volume of the backchamber may be selected such that membrane motion is substantially critically damped.

  4. Randomized clinical trial of dexamethasone versus placebo in laparoscopic inguinal hernia repair

    DEFF Research Database (Denmark)

    Tolver, M A; Strandfelt, P; Bryld, Clara E

    2012-01-01

    The effect of dexamethasone on recovery and length of convalescence has not been evaluated in patients after laparoscopic groin hernia repair. It was hypothesized that preoperative intravenous dexamethasone would reduce postoperative pain.......The effect of dexamethasone on recovery and length of convalescence has not been evaluated in patients after laparoscopic groin hernia repair. It was hypothesized that preoperative intravenous dexamethasone would reduce postoperative pain....

  5. The effect of dexamethasone on the radiation survival response and misonidazole-induced hypoxic-cell cytotoxicity in Chinese hamster cells V-79-753B in vitro

    International Nuclear Information System (INIS)

    Millar, B.C.; Jinks, S.

    1981-01-01

    Overnight exposure of Chinese hamster cells, V-79-753B, to microgram quantities of the synthetic corticosteroid, dexamethasone, resulted in a decrease in sensitivity towards radiation, both in air and in hypoxia. The effect was dose-modifying and the oxygen enhancement ratio did not change appreciably. Similarly, when dexamethasone-treated hypoxic cells were irradiated in the presence of misonidazole, a hypoxic cell radiosensitizer, there was a decrease in radiation sensitivity compared with untreated hypoxic cells irradiated with misonidazole. (author)

  6. Dexamethasone Does Not Inhibit Sugammadex Reversal After Rocuronium-Induced Neuromuscular Block.

    Science.gov (United States)

    Buonanno, Pasquale; Laiola, Anna; Palumbo, Chiara; Spinelli, Gianmario; Servillo, Giuseppe; Di Minno, Raffaele Maria; Cafiero, Tullio; Di Iorio, Carlo

    2016-06-01

    Sugammadex is a relatively new molecule that reverses neuromuscular block induced by rocuronium. The particular structure of sugammadex traps the cyclopentanoperhydrophenanthrene ring of rocuronium in its hydrophobic cavity. Dexamethasone shares the same steroidal structure with rocuronium. Studies in vitro have demonstrated that dexamethasone interacts with sugammadex, reducing its efficacy. In this study, we investigated the clinical relevance of this interaction and its influence on neuromuscular reversal. In this retrospective case-control study, we analyzed data from 45 patients divided into 3 groups: dexamethasone after induction group (15 patients) treated with 8 mg dexamethasone as an antiemetic drug shortly after induction of anesthesia; dexamethasone before reversal group (15 patients) treated with dexamethasone just before sugammadex injection; and control group (15 patients) treated with 8 mg ondansetron. All groups received 0.6 mg/kg rocuronium at induction, 0.15 mg/kg rocuronium at train-of-four ratio (TOF) 2 for neuromuscular relaxation, and 2 mg/kg sugammadex for reversal at the end of the procedure at TOF2. Neuromuscular relaxation was monitored with a TOF-Watch® system. The control group had a recovery time of 154 ± 54 seconds (mean ± SD), the dexamethasone after induction group 134 ± 55 seconds, and the dexamethasone before reversal group 131 ± 68 seconds. The differences among groups were not statistically significant (P = 0.5141). Our results show that the use of dexamethasone as an antiemetic drug for the prevention of postoperative nausea and vomiting does not interfere with reversal of neuromuscular blockade with sugammadex in patients undergoing elective surgery with general anesthesia in contrast to in vitro studies that support this hypothesis.

  7. Recommendations to reduce extremity and eye lens doses in interventional radiology and cardiology

    International Nuclear Information System (INIS)

    Carinou, E.; Brodecki, M.; Domienik, J.; Donadille, L.; Koukorava, C.; Krim, S.; Nikodemová, D.; Ruiz-Lopez, N.; Sans-Merce, M.; Struelens, L.; Vanhavere, F.

    2011-01-01

    The main aim of the Work Package 1 (WP1) of the ORAMED project, Collaborative Project (2008–2011), supported by the European Commission within its 7th Framework Programme, was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology and cardiology (IR/IC) workplaces and to recommend a series of guidelines on radiation protection in order to both guarantee and optimize staff protection. Within the project, coordinated measurements were performed in 34 hospitals in 6 European countries. Furthermore, simulations of the most representative workplaces in IR and IC were performed to determine the main parameters that influence the extremity and eye lens doses. The work presented in this paper shows the recommendations that were formulated by the results obtained from both measurements and simulations. The presented guidelines are directed to operators, assistant personnel, radiation protection officers and medical physics experts. They concern radiation protection issues, such as the use of room protective equipment, as well as the positioning of the extremity and eye lens dosemeters for routine monitoring.

  8. Survival of extremely low-birth-weight infants

    African Journals Online (AJOL)

    Survival of extremely low-birth-weight (ELBW) infants in a resource-limited public hospital setting is still low in South. Africa. is study aimed ... Mortality as a result of prematurity is the major contributor to .... reported from a large cohort study that.

  9. Assessment of low-dose radiotoxicity in microorganisms and higher organisms

    International Nuclear Information System (INIS)

    Obeid, Muhammad Hassan

    2016-01-01

    This work was dedicated to quantify and distinguish the radio- and chemitoxic effects of environmentally relevant low doses of uranium on the metabolism of microorganisms and multicellular organisms by a modern and highly sensitive microcalorimetry. In such low-dose regime, lethality is low or absent. Therefore, quantitative assays based on survival curves cannot be employed, particularly for multicellular organisms. Even in the case of microbial growth, where individual cells may be killed by particle radiation, classical toxicity assessments based on colony counting are not only extremely time-consuming but also highly error-prone. Therefore, measuring the metabolic activity of the organism under such kinds of conditions would give an extremely valuable quantitative measure of viability that is based on life cell monitoring, rather than determining lethality at higher doses and extrapolating it to the low dose regime. The basic concept is simple as it relies on the metabolic heat produced by an organism during development, growth or replication as an inevitable byproduct of all biochemical processes. A metabolic effect in this concept is defined as a change in heat production over time in the presence of a stressor, such as a heavy metal. This approach appeared to be particular versatile for the low dose regime. Thus, the thesis attempted in this case to measure the enthalpy production of a bacterial population as a whole to derive novel toxicity concepts. In the following chapters, an introduction about the properties of ionizing radiation will be briefly presented, in addition to a review about the isothermal calorimetry and its application in studying the bacterial growth. Later in chapter 2, the effect of uranium on the metabolic activity of three different bacterial strains isolated form a uranium mining waste pile together with a reference strain that is genetically related to them will be investigated. Due to the lack of published dedicated calibration

  10. Assessment of low-dose radiotoxicity in microorganisms and higher organisms

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, Muhammad Hassan

    2016-01-11

    This work was dedicated to quantify and distinguish the radio- and chemitoxic effects of environmentally relevant low doses of uranium on the metabolism of microorganisms and multicellular organisms by a modern and highly sensitive microcalorimetry. In such low-dose regime, lethality is low or absent. Therefore, quantitative assays based on survival curves cannot be employed, particularly for multicellular organisms. Even in the case of microbial growth, where individual cells may be killed by particle radiation, classical toxicity assessments based on colony counting are not only extremely time-consuming but also highly error-prone. Therefore, measuring the metabolic activity of the organism under such kinds of conditions would give an extremely valuable quantitative measure of viability that is based on life cell monitoring, rather than determining lethality at higher doses and extrapolating it to the low dose regime. The basic concept is simple as it relies on the metabolic heat produced by an organism during development, growth or replication as an inevitable byproduct of all biochemical processes. A metabolic effect in this concept is defined as a change in heat production over time in the presence of a stressor, such as a heavy metal. This approach appeared to be particular versatile for the low dose regime. Thus, the thesis attempted in this case to measure the enthalpy production of a bacterial population as a whole to derive novel toxicity concepts. In the following chapters, an introduction about the properties of ionizing radiation will be briefly presented, in addition to a review about the isothermal calorimetry and its application in studying the bacterial growth. Later in chapter 2, the effect of uranium on the metabolic activity of three different bacterial strains isolated form a uranium mining waste pile together with a reference strain that is genetically related to them will be investigated. Due to the lack of published dedicated calibration

  11. Low dose radiation damage effects in silicon strip detectors

    International Nuclear Information System (INIS)

    Wiącek, P.; Dąbrowski, W.

    2016-01-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  12. Low dose radiation damage effects in silicon strip detectors

    Science.gov (United States)

    Wiącek, P.; Dąbrowski, W.

    2016-11-01

    The radiation damage effects in silicon segmented detectors caused by X-rays have become recently an important research topic driven mainly by development of new detectors for applications at the European X-ray Free Electron Laser (E-XFEL). However, radiation damage in silicon strip is observed not only after extreme doses up to 1 GGy expected at E-XFEL, but also at doses in the range of tens of Gy, to which the detectors in laboratory instruments like X-ray diffractometers or X-ray spectrometers can be exposed. In this paper we report on investigation of radiation damage effects in a custom developed silicon strip detector used in laboratory diffractometers equipped with X-ray tubes. Our results show that significant degradation of detector performance occurs at low doses, well below 200 Gy, which can be reached during normal operation of laboratory instruments. Degradation of the detector energy resolution can be explained by increasing leakage current and increasing interstrip capacitance of the sensor. Another observed effect caused by accumulation of charge trapped in the surface oxide layer is change of charge division between adjacent strips. In addition, we have observed unexpected anomalies in the annealing process.

  13. Are low radiation doses Dangerous?

    International Nuclear Information System (INIS)

    Garcia Lima, O.; Cornejo, N.

    1996-01-01

    In the last few years the answers to this questions has been affirmative as well as negative from a radiation protection point of view low doses of ionizing radiation potentially constitute an agent causing stochasting effects. A lineal relation without threshold is assumed between dose and probability of occurrence of these effects . Arguments against the danger of probability of occurrence of these effects. Arguments again the danger of low dose radiation are reflected in concepts such as Hormesis and adaptive response, which are phenomena that being studied at present

  14. Genetic efficiency of low-dose chronic irradiation in mammals and fish

    International Nuclear Information System (INIS)

    Goncharova, R.; Ryabokon, N.; Smolich, I.; Slukvin, A.

    2001-01-01

    -linear functions. Thus, we found genetic effects of chronic irradiation in the range of extremely low doses, from close to background and up to 10 cGy. The observed effects are not expected from high dose experiments known from scientific literature. Therefore comparative analysis of genetic efficiency of low dose chronic irradiation and higher doses of acute irradiation was carried out For this purpose linear regression models of dose-effect curves were used for micronucleated erythrocytes in bone marrow of bank voles exposed to chronically irradiation in radiocontaminated sites in natural environment (2.4 and 41.2 micro Gy/day, 0.04 and 0.68 cGy for populations) and to acute gamma-irradiation in laboratory conditions (Cs 137 sources, 5.4 R/min, 10-100 cGy). Comparison of genetic efficiency was made by three approaches: extrapolation, regression line slopes and doubling doses. When we applied extrapolation method, we found (hat the doses of acute irradiation should be much more higher, about 13.1 and 20.9 cGy, than doses of chronic irradiation (0.04 and 0.68 cGy) in order to induce the mutation frequencies, which were observed in chronically irradiated populations. As known, regression line slope or coefficient b in linear dose-effect equation means the induced mutation rate per unit dose. When we compared the regression line slopes, we revealed that the slope values for chronic exposure exceeded slopes for acute irradiation. We found also that the doubling doses of chronic low-LET exposure varied from 0.1 to approximately 2 cGy. This time the doubling doses of acute irradiation were in the range of 5 - 20 cGy. The above facts indicate higher efficiency of low dose chronic irradiation in comparison with the higher doses of acute one. Are there other data about a higher efficiency of small doses? Yes. One of them, the most important, is the data of Radiation Effect Research Foundation. They published that The Excessive Relative Risk for cancer mortality in people per Sv was the

  15. Peptic ulcer disease and other complications in patients receiving dexamethasone palliation for brain metastasis

    International Nuclear Information System (INIS)

    Penzner, R.D.; Lipsett, J.A.

    1982-01-01

    A retrospective analysis was done of 106 patients who received radiation therapy for brain metastasis. Dexamethasone therapy was instituted in 97 patients. Peptic ulcer disease developed in 5 of 89 patients (5.6 percent) who received a dosage of at least 12 mg a day, but did not occur in patients who received a lower dose or in those who did not receive steroids. The interval between institution of dexamethasone therapy and the development of peptic ulcer disease ranged from three to nine weeks. Two patients had perforated ulcers, one of whom required surgical resection. Peptic ulcer disease contributed to the general deterioration and death of three of the five patients. Overall, in 14 of the 89 patients (15.7 percent) a complication of steroid therapy developed in the form of peptic ulcer disease, steroid myopathy or diabetes mellitus (or a combination of these)

  16. Paradoxical response to dexamethasone and spontaneous hypocortisolism in Cushing's disease

    OpenAIRE

    Lila, Anurag R; Sarathi, Vijaya; Bandgar, Tushar R; Shah, Nalini S

    2013-01-01

    Paradoxical response to dexamethasone and spontaneous development of hypocortisolism are rare features of Cushing's disease. We report a 13-year-old boy with Cushing's disease owing to a pituitary macroadenoma. On initial evaluation, he had partial suppression of serum cortisol by dexamethasone. He developed transient hypocortisolism after first adenomectomy, but the disease recurred after 1 year. Repeat evaluation showed recurrent hypercortisolism and paradoxical response to dexamethasone. H...

  17. The use of dexamethasone in animals: implication for fertility ...

    African Journals Online (AJOL)

    Exposure to dexamethasone causes numerous changes in various biological systems including the reproductive system and this has huge implication on fertility and pregnancy. Maternal dexamethasone administration promotes foetal lung maturation and thermoregulation in premature foetuses. This indication makes ...

  18. Dose-response relationships and risk estimates for the induction of cancer due to low doses of low-LET radiation

    International Nuclear Information System (INIS)

    Elaguppillai, V.

    1981-01-01

    Risk estimates for radiation-induced cancer at low doses can be obtained only by extrapolation from the known effects at high doses and high dose rates, using a suitable dose-response model. The applicability of three different models, linear, sublinear and supralinear, are discussed in this paper. Several experimental studies tend to favour a sublinear dose-response model (linear-quadratic model) for low-LET radiation. However, human epidemiological studies do not exclude any of the dose-response relationships. The risk estimates based on linear and linear quadratic dose-response models are compared and it is concluded that, for low-LET radiation, the linear dose-response model would probably over-estimate the actual risk of cancer by a factor of two or more. (author)

  19. The effect of preoperative dexamethasone on pain 1 year after lumbar disc surgery

    DEFF Research Database (Denmark)

    Nielsen, Rikke Vibeke; Fomsgaard, Jonna; Mathiesen, Ole

    2016-01-01

    discectomy. METHODS: This is a prospective 1-year follow-up on a single-centre, randomized, and blinded trial exploring the analgesic effect of 16 mg IV dexamethasone or placebo after lumbar discectomy. One year follow-up was a written questionnaire including back and leg pain (VAS 0-100 mm), Short Form 36...... survey (SF-36), EuroQol 5D (EQ-5D), OSWESTRY Low Back Pain Questionnaire, duration of sick leave, working capability, contentment with surgical result. RESULTS: Response rate was 71% (55 patients) in the dexamethasone group, 58% (44 patients) in the placebo group. Leg pain (VAS) was significantly lower...... in the placebo group compared to the dexamethasone group: 17 (95% CI 10-26) vs 26 (95% CI 19-33) mm, respectively (mean difference 9 mm (95% CI -1 to 0), (P = 0.03). No difference regarding back pain. The placebo group reported significantly more improvement of leg pain and were significantly more satisfied...

  20. The Effect of Dexamethasone on Symptoms of Posttraumatic Stress Disorder and Depression After Cardiac Surgery and Intensive Care Admission: Longitudinal Follow-Up of a Randomized Controlled Trial.

    Science.gov (United States)

    Kok, Lotte; Hillegers, Manon H; Veldhuijzen, Dieuwke S; Cornelisse, Sandra; Nierich, Arno P; van der Maaten, Joost M; Rosseel, Peter M; Hofland, Jan; Sep, Milou S; Dieleman, Jan M; Vinkers, Christiaan H; Peelen, Linda M; Joëls, Marian; van Dijk, Diederik

    2016-03-01

    Cardiac surgery and postoperative admission to the ICU may lead to posttraumatic stress disorder and depression. Perioperatively administered corticosteroids potentially alter the risk of development of these psychiatric conditions, by affecting the hypothalamic-pituitary-adrenal axis. However, findings of previous studies are inconsistent. We aimed to assess the effect of a single dose of dexamethasone compared with placebo on symptoms of posttraumatic stress disorder and depression and health-related quality of life after cardiac surgery and ICU admission. Follow-up study of a randomized clinical trial. Five Dutch heart centers. Cardiac surgery patients (n = 1,244) who participated in the Dexamethasone for Cardiac Surgery trial. A single intraoperative IV dose of dexamethasone or placebo was administered in a randomized, double-blind way. Symptoms of posttraumatic stress disorder, depression, and health-related quality of life were assessed with validated questionnaires 1.5 years after randomization. Data were available for 1,125 patients (90.4%); of which 561 patients received dexamethasone and 564 patients received placebo. Overall, the prevalence of psychopathology was not influenced by dexamethasone. Posttraumatic stress disorder and depression were present in, respectively, 52 patients (9.3%) and 69 patients (12.3%) who received dexamethasone and in 66 patients (11.7%) and 78 patients (13.8%) who received placebo (posttraumatic stress disorder: odds ratio, 0.82; 95% CI, 0.55-1.20; p = 0.30; depression: odds ratio, 0.92; 95% CI, 0.64-1.31; p = 0.63). Subgroup analysis revealed a lower prevalence of posttraumatic stress disorder (odds ratio, 0.23; 95% CI, 0.07-0.72; p stress disorder and depression. However, in female patients, beneficial effects on the occurrence of posttraumatic stress disorder and depression may be present.

  1. Cytogenetic effects of low-dose radiation

    International Nuclear Information System (INIS)

    Metalli, P.

    1983-01-01

    The effects of ionizing radiation on chromosomes have been known for several decades and dose-effect relationships are also fairly well established in the mid- and high-dose and dose-rate range for chromosomes of mammalian cells. In the range of low doses and dose rates of different types of radiation few data are available for direct analysis of the dose-effect relationships, and extrapolation from high to low doses is still the unavoidable approach in many cases of interest for risk assessment. A review is presented of the data actually available and of the attempts that have been made to obtain possible generalizations. Attention is focused on some specific chromosomal anomalies experimentally induced by radiation (such as reciprocal translocations and aneuploidies in germinal cells) and on their relevance for the human situation. (author)

  2. Effects of dexamethasone on liver enzymes and some serum ...

    African Journals Online (AJOL)

    Concomitant usage of dexamethasone and other medications may alter electrolyte metabolism and increase the formation of potentially hepatotoxic reactive metabolites which can contribute to elevated liver enzymes. The role of dexamethasone in liver functions and electrolyte metabolism during pregnancy in Yankasa ...

  3. Tapered oral dexamethasone for the acute chest syndrome of sickle cell disease

    Science.gov (United States)

    Quinn, Charles T.; Stuart, Marie J.; Kesler, Karen; Ataga, Kenneth I.; Wang, Winfred C.; Styles, Lori; Smith-Whitley, Kim; Wun, Ted; Raj, Ahsok; Hsu, Lewis L.; Krishnan, Suba; Kuypers, Frans A; Setty, B. N. Yamaja; Rhee, Seungshin; Key, Nigel S.; Buchanan, George R.

    2011-01-01

    Summary Tapered oral dexamethasone for acute chest syndrome (ACS) in sickle cell anaemia was studied using a novel ACS assessment tool and investigational biomarkers. Twelve participants were randomized (mean age 17.3 years) before early study termination. Dexamethasone decreased duration of hospitalization for ACS by 20.8 h compared to placebo (P=0.024). Rebound pain occurred in both groups (3 dexamethasone vs. 1 placebo). Overall, dexamethasone decreased the leucocyte activation biomarker, sL-selectin; however, participants with rebound pain had higher sL-selectin within 24 h of treatment (dexamethasone or placebo). This ACS assessment tool was feasibly applied, and sL-selectin is a promising biomarker of ACS therapy. PMID:21848879

  4. Dexamethasone minimizes the risk of cranial nerve injury during CEA.

    Science.gov (United States)

    Regina, Guido; Angiletta, Domenico; Impedovo, Giovanni; De Robertis, Giovanni; Fiorella, Marialuisa; Carratu', Maria Rosaria

    2009-01-01

    The incidence of cranial and cervical nerve injury during carotid endarterectomy (CEA) ranges from less than 7.6% to more than 50%. Lesions are mainly due to surgical maneuvers such as traction, compression, tissue electrocoagulation, clamping, and extensive dissections. The use of dexamethasone (DEX) and its beneficial effects in spinal cord injuries have already been described. We investigated whether DEX could also be beneficial to minimize the incidence of cranial and cervical nerve injury during CEA. To evaluate whether dexamethasone is able to reduce the incidence of cranial nerve injuries. From March 1999 through April 2006, 1126 patients undergoing CEA because of high-grade carotid stenosis were enrolled and randomized by predetermined randomization tables into two groups. The first group, "A", included 586 patients that all received an intravenous administration of dexamethasone following a therapeutic scheme. The second group, "B", included 540 control subjects that received the standard pre- and postoperative therapy. All patients were submitted to a deep cervical plexus block, eversion carotid endarterectomy, and selective shunting. Three days after the operation, an independent neurologist and otorhinolaryngologist evaluated the presence of cranial nerve deficits. All patients (group A and group B) showing nerve injuries continued the treatment (8 mg of dexamethasone once in the morning) for 7 days and were re-evaluated after 2 weeks, 30 days, and every 3 months for 1 year. Recovery time took from 2 weeks to 12 months, with a mean time of 3.6 months. The chi(2) test was used to compare the two groups and to check for statistical significance. The incidence of cranial nerve dysfunction was higher in group B and the statistical analysis showed a significant effect of dexamethasone in preventing the neurological damage (P = .0081). The incidence of temporary lesions was lower in group A and the chi(2) test yielded a P value of .006. No statistically

  5. Effects of dexamethasone on brain edema. Uptake and distribution of tritiated (/sup 3/H) dexamethasone in cold induced edema

    Energy Technology Data Exchange (ETDEWEB)

    Takemoto, Motohisa [Okayama Univ. (Japan). School of Medicine

    1982-06-01

    Experimental cerebral edema was produced on the right parietal lobe of Wistar male rats with a cold metal probe cooled by liquid nitrogen. Twenty hour later, /sup 3/H-dexamethasone was either intramuscularly or intravenously injected into rats, estimated in the brain tissue by the liquid scintillation counting method. Edematous brain generally contained much higher /sup 3/H-activity than the control. Furthermore, I.V. injection showed higher /sup 3/H-activity than I.M injection in edematous and control brains at all times. For examination of the subcellular distribution of /sup 3/H-dexamethasone in edematous brain, /sup 3/H-activity was most strongly detected in the supernatant fraction (63%), followed by the heavy mitochondrial fraction (25.4%) and the nuclear fraction (8.4%). Although edematous brain tissue constantly demonstrated higher /sup 3/H-activity than the control, its supernatant fraction conversely had less activity. As a next step, distribution of /sup 3/H-dexamethasone in the supernatant fraction was studies. The result was that the high molecular weight fraction in the edematous brain showed higher radioactivity than the control. From these findings, unequivocal distribution of dexamethasone in the supernatant fraction of edematous brain tissue could be correlated with its biochemical action for preventing brain edema.

  6. Definitive intraoperative very high-dose radiotherapy for localized osteosarcoma in the extremities

    International Nuclear Information System (INIS)

    Oya, Natsuo; Kokubo, Masaki; Mizowaki, Takashi; Shibamoto, Yuta; Nagata, Yasushi; Sasai, Keisuke; Nishimura, Yasumasa; Tsuboyama, Tadao; Toguchida, Junya; Nakamura, Takashi; Hiraoka, Masahiro

    2001-01-01

    Purpose: To evaluate the outcome and adverse effects in patients with osteosarcoma treated with very high-dose definitive intraoperative radiotherapy (IORT), with the intention of saving the affected limb. Methods and Materials: Thirty-nine patients with osteosarcoma in their extremities were treated with definitive IORT. The irradiation field included the tumor plus an adequate wide margin and excluded the major vessels and nerves. Forty-five to 80 Gy of electrons or X-rays were delivered. The median follow-up of the surviving patients was 124 months. Results: The cause-specific and relapse-free 5-year survival rate was 50% and 43%, respectively. Distant metastasis developed in 23 patients; 19 died and 4 were alive for >10 years. Nine local recurrences were found 4-29 months after IORT in the affected limb. No radiation-induced skin reaction or nerve palsy was observed in the patients treated with X-rays. Experiments using phantoms also confirmed that the scatter dose was below the toxic level in the IORT setting with X-rays. Conclusions: Very high-dose definitive IORT combined with preventive nailing and chemotherapy appeared to be a promising quality-of-life-oriented alternative to treating patients with osteosarcomas in the extremities, although the problem of recurrences from the surrounding unirradiated soft tissue remains to be solved

  7. Pre- and postoperative dexamethasone does not reduce bleaching-induced tooth sensitivity: A randomized, triple-masked clinical trial.

    Science.gov (United States)

    Rezende, Márcia; Bonafé, Elize; Vochikovski, Laína; Farago, Paulo Vitor; Loguercio, Alessandro Dourado; Reis, Alessandra; Kossatz, Stella

    2016-01-01

    Tooth sensitivity (TS) is the most common side effect of dental bleaching therapies. Dexamethasone has been used with tooth bleaching to reduce TS. The efficacy of dexamethasone for this purpose has not been well studied. The authors conducted a triple-masked, randomized, clinical trial with a parallel design involving 63 healthy participants who received either a placebo or dexamethasone. The placebo or dexamethasone (8 milligrams) was administered 1 hour before the in-office bleaching (35% hydrogen peroxide) and extra doses of 4 mg were administered every 6 hours for a total of 48 hours. TS was recorded on 2 scales: visual analog scale (0-10) and numeric rating scale (0-4) in different periods. The color evaluations were performed before and 1 month after dental bleaching with visual shade guides VITA Classical (VITA Zahnfabrik) and VITA Bleachedguide 3D-MASTER (VITA Zahnfabrik), and for a shade guide evaluation, the authors used a digital spectrophotometer, VITA Easyshade (VITA Zahnfabrik). The absolute risk of TS was evaluated by a Fisher exact test. Data of TS intensity using the NRS scale for the 2 groups were compared with Mann-Whitney and Friedman tests, whereas data from the visual analog scale were evaluated by 2-way repeated measures analysis of variance. The color changes between groups were compared using a t test (α = .05). In both groups, the authors detected a high risk of TS, which was approximately 90%. No significant difference was observed in terms of TS intensity. A whitening of approximately 3 shade guide units of the VITA Classical was detected in both groups, which were statistically similar. The use of dexamethasone before bleaching did not reduce the risk and intensity of bleaching-induced TS. The use of the steroidal anti-inflammatory agent dexamethasone was not capable of preventing TS arising from in-office dental bleaching. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  8. Piper sarmentosum is comparable to glycyrrhizic acid in reducing visceral fat deposition in adrenalectomised rats given dexamethasone.

    Science.gov (United States)

    Fairus, A; Ima Nirwana, S; Elvy Suhana, M R; Tan, M H; Santhana, R; Farihah, H S

    2013-01-01

    Visceral obesity may be due to the dysregulation of cortisol production or metabolism that lead to metabolic disease. In adipose tissue, the enzyme 11beta-hydroxysteroid dehydrogenase type 1 regulates cortisol metabolism (11beta-HSD1). A previous study showed an increase in the visceral fat deposition in adrenalectomised rats given intramuscular dexamethasone. Glycyrrhizic acid (GCA) has been shown to reduce fat deposition because it is a known potent inhibitor of the 11beta-HSD1 enzyme. Piper sarmentosum (PS) is an edible medicinal plant commonly used in Asia as traditional medicine for treating diabetes, hypertension and joint pains. In this study, we determined the effects of PS extract on the disposition and morphology of perirenal adipocytes of adrenalectomised rats given intramuscular dexamethasone. A total of 21 male Spraque Dawley rats were adrenalectomised and given intramuscular dexamethasone, 120 μg/kg/day. These rats were further divided into three groups: adrenalectomised control (ADR+Dexa; n=7), GCA-treated (ADR+Dexa+GCA; dose=240 mg/kg/day; n=7) and PS-treated (ADR+Dexa+PS; dose=125 mg/kg/day; n=7) groups. The various treatments were given via gastric gavage following 2 weeks of adrenalectomy. Treatment with PS extract for 8 weeks showed decreased deposition of perirenal adipocytes which was similar to the GCA-treated group. However, PS-treated rats had thinner adipocyte membrane compared with that of the GCA-treated group. In conclusion, PS extract decreased perirenal fat deposition and reduced the diameter of the adipocyte membrane. However, the mechanisms of action needed further study.

  9. Optimizing image quality and dose for digital radiography of distal pediatric extremities using the contrast-to-noise ratio

    International Nuclear Information System (INIS)

    Hess, R.; Neitzel, U.

    2012-01-01

    Purpose: To investigate the influence of X-ray tube voltage and filtration on image quality in terms of contrast-to-noise ratio (CNR) and dose for digital radiography of distal pediatric extremities and to determine conditions that give the best balance of CNR and patient dose. Materials and Methods: In a phantom study simulating the absorption properties of distal extremities, the CNR and the related patient dose were determined as a function of tube voltage in the range 40 - 66 kV, both with and without additional filtration of 0.1 mm Cu/1 mm Al. The measured CNR was used as an indicator of image quality, while the mean absorbed dose (MAD) - determined by a combination of measurement and simulation - was used as an indicator of the patient dose. Results: The most favorable relation of CNR and dose was found for the lowest tube voltage investigated (40 kV) without additional filtration. Compared to a situation with 50 kV or 60 kV, the mean absorbed dose could be lowered by 24 % and 50 %, respectively, while keeping the image quality (CNR) at the same level. Conclusion: For digital radiography of distal pediatric extremities, further CNR and dose optimization appears to be possible using lower tube voltages. Further clinical investigation of the suggested parameters is necessary. (orig.)

  10. Effect of postoperative dexamethasone on pain, emesis and haemorrhage in tonsillectomy by dissection method

    International Nuclear Information System (INIS)

    Khan, K.A.; Faiz, S.B.

    2013-01-01

    Objectives: To compare the effect of postoperative intravenous dose of dexamethasone on morbidity in patients undergoing tonsillectomy. Design: Randomized control trial. Place and Duration of Study: This study was conducted in ENT Department Shaikh Khalifa Bin Zayed Al Nahyan Hospital (CMH) Muzaffarabad from 10th Jan 2010 to 15th Feb 2011. Patients and Methods: After getting informed consent, a total of 60 patients who fulfilled the inclusion criteria were selected and tonsillectomy by dissection method was carried out. They were divided into two groups of 30 each using a random numbers table. Group A received 0.25 mg/kg body weight (maximum 20 mg) of Dexamethasone postoperatively intravenously for 03 days while group B (control group) did not receive any steroid. Results: In group A, 80% patients had mild pain, 16.7% had moderate pain and 3.3% had a severe pain while in group B, 30% patients had mild pain, 6.7% had moderate pain and 63.3% had severe pain (p< 0.05). In group A, 76.7% patients had mild emesis while in group B, 86.7% had moderate emesis (p< 0.05). There was an insignificant difference in secondary hemorrhage. Conclusion: Dexamethasone given postoperatively significantly reduces the morbidity that is pain, episodes of emesis thus early recovery to a normal lifestyle with no effect on secondary hemorrhage in patients undergoing Tonsillectomy by dissection method. (author)

  11. Pre-emptive 8 mg dexamethasone and 120 mg etoricoxib for pain prevention after periodontal surgery: A randomised controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Kranti Konuganti

    2015-01-01

    Full Text Available Several anti-inflammatory drugs have been used to reduce pain and discomfort after periodontal surgeries. This study evaluates the efficacy of using etoricoxib and dexamethasone for pain prevention after open-flap debridement surgery. In this study, 60 patients who were undergoing open flap debridment surgery were randomly assigned to receive a single dose preoperative medication 1 hour prior to surgery. The patients were divided into three groups. In Group 1, 20 patients were given placebo drug orally. In Group 2, 20 patients were given 8 mg Dexamethasone orally and in Group 3, 20 patients were given 120 mg Etoricoxib orally. Patients were instructed to complete a pain diary hourly for the first 8 hours after each surgery and three times a day on the following 3 days. The four point verbal rating scale (VRS 4 and Numerical rate scale were used to assess discomfort. Post-operative Assessment of Pain and Discomfort showed that persistent discomfort and pain were found to be more in the placebo group compared to dexamethasone and etoricoxib group. The adoption of a preemptive medication protocol using either etoricoxib or dexamethasone may be considered effective for pain and discomfort prevention after open-flap debridement surgeries.

  12. Low-dose effects of hormones and endocrine disruptors.

    Science.gov (United States)

    Vandenberg, Laura N

    2014-01-01

    Endogenous hormones have effects on tissue morphology, cell physiology, and behaviors at low doses. In fact, hormones are known to circulate in the part-per-trillion and part-per-billion concentrations, making them highly effective and potent signaling molecules. Many endocrine-disrupting chemicals (EDCs) mimic hormones, yet there is strong debate over whether these chemicals can also have effects at low doses. In the 1990s, scientists proposed the "low-dose hypothesis," which postulated that EDCs affect humans and animals at environmentally relevant doses. This chapter focuses on data that support and refute the low-dose hypothesis. A case study examining the highly controversial example of bisphenol A and its low-dose effects on the prostate is examined through the lens of endocrinology. Finally, the chapter concludes with a discussion of factors that can influence the ability of a study to detect and interpret low-dose effects appropriately. © 2014 Elsevier Inc. All rights reserved.

  13. Low dose irradiation and biological defense mechanisms

    International Nuclear Information System (INIS)

    Sugahara, Tsutomu; Sagan, L.A.; Aoyama, Takashi

    1992-01-01

    It has been generally accepted in the context of radiation protection that ionizing radiation has some adverse effect even at low doses. However, epidemiological studies of human populations cannot definitively show its existence or absence. Furthermore, recent studies of populations living in areas of different background radiation levels reported some decrease in adverse health effects at high background levels. Genetic studies of atomic bomb survivors failed to produce statistically significant findings on the mutagenic effects of ionizing radiation. A British study however, suggests that a father's exposure to low dose radiation on the job may increase his children's risk of leukemia. On the other hand, many experimental studies have raised the possibility that low doses of ionizing radiation may not be harmful or may even produce stimulating or adaptive responses. The term 'hormesis' has come to be used to describe these phenomena produced by low doses of ionizing radiation when they were beneficial for the organisms studied. At the end of the International Conference on Low Dose Irradiation one conclusion appeared to be justified: radiation produces an adaptive response, though it is not universally detected yet. The conference failed to obtain any consensus on risk assessment at low doses, but raised many problems to be dealt with by future studies. The editors therefore believe that the Proceedings will be useful for all scientists and people concerned with radiation protection and the biological effects of low-dose irradiation

  14. Topics on study of low dose-effect relationship

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Takeshi [Toho Univ., School of Medicine, Tokyo (Japan); Ohyama, Harumi

    1999-09-01

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  15. Topics on study of low dose-effect relationship

    International Nuclear Information System (INIS)

    Yamada, Takeshi; Ohyama, Harumi

    1999-01-01

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  16. The role of dexamethasone in peripheral and neuraxial nerve blocks ...

    African Journals Online (AJOL)

    pain and prolongs analgesia in the postoperative period when combined with ... management of acute pain and that focused on dexamethasone's ability to prolong ... of dexamethasone to brachial plexus nerve blocks and Akram and Hassani ...

  17. Estimation of radiation risks at low dose

    International Nuclear Information System (INIS)

    1990-04-01

    The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

  18. Dexamethasone and long-term outcome of tuberculous meningitis in Vietnamese adults and adolescents.

    Directory of Open Access Journals (Sweden)

    M Estée Török

    Full Text Available Dexamethasone has been shown to reduce mortality in patients with tuberculous meningitis but the long-term outcome of the disease is unknown.Vietnamese adults and adolescents with tuberculous meningitis recruited to a randomised, double-blind, placebo-controlled trial of adjunctive dexamethasone were followed-up at five years, to determine the effect of dexamethasone on long-term survival and neurological disability.545 patients were randomised to receive either dexamethasone (274 patients or placebo (271 patients. 50 patients (9.2% were lost to follow-up at five years. In all patients two-year survival, probabilities tended to be higher in the dexamethasone arm (0.63 versus 0.55; p = 0.07 but five-year survival rates were similar (0.54 versus 0.51, p = 0.51 in both groups. In patients with grade 1 TBM, but not with grade 2 or grade 3 TBM, the benefit of dexamethasone treatment tended to persist over time (five-year survival probabilities 0.69 versus 0.55, p = 0.07 but there was no conclusive evidence of treatment effect heterogeneity by TBM grade (p = 0.36. The dexamethasone group had a similar proportion of severely disabled patients among survivors at five years as the placebo group (17/128, 13.2% vs. 17/116, 14.7% and there was no significant association between dexamethasone treatment and disability status at five years (p = 0.32.Adjunctive dexamethasone appears to improve the probability of survival in patients with TBM, until at least two years of follow-up. We could not demonstrate a five-year survival benefit of dexamethasone treatment which may be confined to patients with grade 1 TBM.ClinicalTrials.gov NCT01317654.

  19. Low-functional programming of the CREB/BDNF/TrkB pathway mediates cognitive impairment in male offspring after prenatal dexamethasone exposure.

    Science.gov (United States)

    Dong, Wanting; Xu, Dan; Hu, Zewen; He, Xia; Guo, Zijing; Jiao, Zhexiao; Yu, Ying; Wang, Hui

    2018-02-01

    Adverse intrauterine environments can increase susceptibility to neuropsychiatric diseases that are related to cognitive impairment. In this study, we observed the cognitive impairment of male offspring rats after prenatal dexamethasone exposure (PDE) and explored the associated intrauterine programming mechanism. Pregnant Wistar rats were subcutaneously injected with 0.2mg/kgd dexamethasone from gestational day 9 (GD9) to GD20. A cohort of the pregnant rat group was sacrificed on GD20, and the male fetal rats were collected. Another group of pregnant rats delivered their offspring naturally, and the male adult offspring rats were subjected to behavioural tests postnatally at 26 weeks and then sacrificed. The adult PDE male offspring rats exhibited cognitive impairment, decreased cell proliferation and increased cell apoptosis in the hippocampus, along with damaged synaptic plasticity and disrupted protein synthesis. Meanwhile, activation of GR and downregulation of the cAMP responsive element binding protein (CREB)/brain-derived neurotrophic factor (BDNF)/tropomyosin receptor tyrosine B (TrkB) signalling pathway were found in the adult PDE offspring rats. Further examinations indicated consistent alterations to the fetal hippocampus by PDE. We concluded that PDE can cause cognitive impairment in adult male offspring rats. The mechanism may be associated with low-functional programming of the hippocampal CREB/BDNF/TrkB signalling pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Late effects of low doses and dose rates

    International Nuclear Information System (INIS)

    Paretzke, H.G.

    1980-01-01

    This paper outlines the spectrum of problems and approaches used in work on the derivation of quantitative prognoses of late effects in man of low doses and dose rates. The origins of principal problems encountered in radiation risks assessments, definitions and explanations of useful quantities, methods of deriving risk factors from biological and epidemiological data, and concepts of risk evaluation and problems of acceptance are individually discussed

  1. Total-dose hardness assurance for low earth orbit

    International Nuclear Information System (INIS)

    Maurer, R.H.; Suter, J.J.

    1987-01-01

    The Low Earth Orbit radiation environment has two significant characteristics that make laboratory simulation exposures difficult: (1) a low dose rate and (2) many cycles of low dose accumulation followed by dose-free annealing. Hardness assurance considerations for this environment are discussed and related to data from the testing of Advanced Low Power Schottky and High-speed CMOS devices

  2. Effect of venous dexamethasone, oral caffeine and acetaminophen on relative frequency and intensity of postdural puncture headache after spinal anesthesia.

    Science.gov (United States)

    Masoudifar, Mehrdad; Aghadavoudi, Omid; Adib, Sajjad

    2016-01-01

    Postdural puncture headache (PDPH) is a relatively common complication after regional anesthesia, especially in younger people, bothersome to patients and needs prophylaxis to prevent this complication. This study was conducted aiming to determine the preventive effect of dexamethasone plus caffeine and acetaminophen on relative frequency and intensity of PDPH after spinal anesthesia. In a clinical trial study, 90 candidates for the lower extremities orthopedic elective operation were divided into two groups of 45 individuals each. Intervention group received the compound of 500 mg acetaminophen +65 mg oral caffeine +8 mg venous dexamethasone an hour before spinal blocking, and the control group received placebo tablets + a dexamethasone equivalent volume of venous normal saline. The level of postoperative headache at the time of entrance to recovery and discharge, 6, 12, 24, 48, and 72 h postoperatively were measured based on Visual Analog Scale criterion in the two groups and then compared with each other. During the study, 24 patients in the control group and 17 patients in the intervention group were afflicted with headache; however, with no significant difference (P = 0.14). Total frequency of headache incidence was 35 times in the control group and 27 times in the intervention group (P = 0.32). Though the taking of acetaminophen + caffeine + dexamethasone is associated with a decrease in headache intensity and duration and decrease in PDPH incidence, compared with placebo, however, no essentially and statistically significant effect was produced.

  3. Dexamethasone and Long-Term Outcome of Tuberculous Meningitis in Vietnamese Adults and Adolescents

    Science.gov (United States)

    Török, M. Estée; Bang, Nguyen Duc; Chau, Tran Thi Hong; Yen, Nguyen Thi Bich; Thwaites, Guy E.; Thi Quy, Hoang; Dung, Nguyen Huy; Hien, Tran Tinh; Chinh, Nguyen Tran; Thi Thanh Hoang, Hoang; Wolbers, Marcel; Farrar, Jeremy J.

    2011-01-01

    Background Dexamethasone has been shown to reduce mortality in patients with tuberculous meningitis but the long-term outcome of the disease is unknown. Methods Vietnamese adults and adolescents with tuberculous meningitis recruited to a randomised, double-blind, placebo-controlled trial of adjunctive dexamethasone were followed-up at five years, to determine the effect of dexamethasone on long-term survival and neurological disability. Results 545 patients were randomised to receive either dexamethasone (274 patients) or placebo (271 patients). 50 patients (9.2%) were lost to follow-up at five years. In all patients two-year survival, probabilities tended to be higher in the dexamethasone arm (0.63 versus 0.55; p = 0.07) but five-year survival rates were similar (0.54 versus 0.51, p = 0.51) in both groups. In patients with grade 1 TBM, but not with grade 2 or grade 3 TBM, the benefit of dexamethasone treatment tended to persist over time (five-year survival probabilities 0.69 versus 0.55, p = 0.07) but there was no conclusive evidence of treatment effect heterogeneity by TBM grade (p = 0.36). The dexamethasone group had a similar proportion of severely disabled patients among survivors at five years as the placebo group (17/128, 13.2% vs. 17/116, 14.7%) and there was no significant association between dexamethasone treatment and disability status at five years (p = 0.32). Conclusions Adjunctive dexamethasone appears to improve the probability of survival in patients with TBM, until at least two years of follow-up. We could not demonstrate a five-year survival benefit of dexamethasone treatment which may be confined to patients with grade 1 TBM. Trial Registration ClinicalTrials.gov NCT01317654 NCT01317654?term = tuberculous+meningitis&rank = 3 PMID:22174748

  4. Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E

    2003-07-01

    In reviewing tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defenses, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. (author)

  5. Relative implications of protective responses versus damage induction at low dose and low-dose-rate exposures, using the microdose approach

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2003-01-01

    In reviewing tissue effects of low-dose radiation (1) absorbed dose to tissue is replaced by the sum of energy deposited with track events in cell-equivalent tissue micromasses, i.e. with microdose hits, in the number of exposed micromasses and (2) induced cell damage and adaptive protection are related to microdose hits in exposed micromasses for a given radiation quality. DNA damage increases with the number of microdose hits. They also can induce adaptive protection, mainly against endogenous DNA damage. This protection involves cellular defenses, DNA repair and damage removal. With increasing numbers of low linear energy transfer (LET) microdose hits in exposed micromasses, adaptive protection first tends to outweigh damage and then (above 200 mGy) fails and largely disappears. These experimental data predict that cancer risk coefficients derived by epidemiology at high-dose irradiation decline at low doses and dose rates when adaptive protection outdoes DNA damage. The dose-risk function should include both linear and non-linear terms at low doses. (author)

  6. Modification of damage following low doses

    International Nuclear Information System (INIS)

    Braby, L.A.; Nelson, J.M.; Metting, N.F.

    1988-01-01

    At very low doses the damage-interaction mechanism is responsible for very little lethal or potentially lethal damage, and repair of the latter should essentially disappear. An alternative model suggests that potentially lethal damage is either repaired with a constant half time or misrepaired at a rate which is proportional to the square of the damage concentration. In this case, as the dose decreases, the probability of misrepair decreases faster than the probability of repair, and repair becomes a more pronounced feature of the cell response. Since the consequence of unrepaired damage is an important question in determining the effects of low doses of radiation delivered at low dose rates, we have attempted to determine which of these two types of models is consistent with the response of plateau-phase CHO cells. In the earlier experiments, there was no indication of repair after a 50-rad exposure with a 24-hour split dose or plating delay; in fact, immediate plating resulted in survival slightly above control and delayed plating in survival slightly below the control value

  7. Effect of dexamethasone in primary intracerebral hemorrhage in the south west of iran

    International Nuclear Information System (INIS)

    Sharafadinzadeh, N.; Baghebanian, S.M.; Pipelzadeh, M.; Moravej, A. A.; Ghanavatiz, P.

    2008-01-01

    Previous study revealed the value of dexamethasone in the treatment of vasogenic edema associated with brain tumor and abscess. However there are poor documented studies about its usefulness in primary intracerebral hemorrhage. In this study we evaluated dexamethasone effects in primary intracerebral hemorrhage. In a double blind randomized placebo-controlled clinical trial we evaluated 200 intracerebral hemorrhage cases between 40 to 80 years old whom were admitted at Golestan Hospital (Ahwaz, IR) between March 2002 and March 2003. They were divided in two groups dexamethasone (N=100) and placebo (N=100). Then mortality, GI bleeding, fever, electrolytes disturbances, hypertension and hyperglycemic status were analyzed in two groups. Ethical considerations were employed and subjects were followed by appropriate statistical methods for 21 days to assess the major outcomes. Mortality was much higher in the dexamethasone group; Dexamethasone group (49.3%) and placebo (23.4%) and also fever was higher seen in the dexamethasone group; dexamethasone group (40.2%) and placebo group (24.7%) but there was not any significant statistical difference between two groups as regards other complications. Dexamethasone is widely used for cerebral edema associated conditions but in this study we saw that it's complications in intracerebral hemorrhage such as increasing fever and mortality are significantly higher. Hence it use for treatment of primary intracerebral hemorrhage should be reconsidered. (author)

  8. Comparative toxicity of 4 commonly used intravitreal corticosteroids on rat retina.

    Science.gov (United States)

    Citirik, Mehmet; Dilsiz, Nihat; Batman, Cosar; Zilelioglu, Orhan

    2009-06-01

    To investigate the effects of 4 commonly used steroids (dexamethasone, triamcinolone, betamethasone, and methylprednisolone) on 50 retinas of 25 adult pigmented rats. Experimental animal study. Twenty-five pigmented Long-Evans male rats. Each steroid drug with 2 different doses (0.025 mL and 0.050 mL) was injected into the vitreous of each eye of 5 rats. The low drug dose was injected into the right eye and the high dose was injected into the left eye. Ten eyes of 5 randomly selected rats were used as a control group and intravitreal saline was injected into these eyes. Oxidative damage and intrinsic antioxidative capacity were determined by measuring retinal malondialdehyde (MDA) and glutathione (GSH) levels, respectively. No statistically meaningful difference was observed in retinal GSH and MDA measurements in the low- and high-dose triamcinolone (1 and 2 mg), low-dose betamethasone (0.075 mg), and low-dose dexamethasone (0.1 mg) groups, compared with the control group. Both doses of methylprednisolone (1.6 mg and 3.2 mg), high-dose betamethasone (0.15 mg), and high-dose dexamethasone (0.2 mg) markedly altered retinal GSH and MDA levels. The results of our study show that the toxicity of triamcinolone is not evident even in high doses. It may be used safely. We also suggest that intravitreal use of low doses of betamethasone and dexamethasone is safer than higher doses of these drugs and both doses of methylprednisolone.

  9. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    International Nuclear Information System (INIS)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E.

    2015-01-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm

  10. Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Grewenig, Angelika; Schuler, Nadine; Rübe, Claudia E., E-mail: claudia.ruebe@uks.eu

    2015-08-01

    Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.

  11. Low-dose vaporized cannabis significantly improves neuropathic pain.

    Science.gov (United States)

    Wilsey, Barth; Marcotte, Thomas; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

    2013-02-01

    We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling medium-dose (3.53%), low-dose (1.29%), or placebo cannabis with the primary outcome being visual analog scale pain intensity. Psychoactive side effects and neuropsychological performance were also evaluated. Mixed-effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the 2 active dose groups' results (P > .7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo versus low-dose, 2.9 for placebo versus medium-dose, and 25 for medium- versus low-dose. As these NNTs are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well tolerated, and neuropsychological effects were of limited duration and readily reversible within 1 to 2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. The analgesia obtained from a low dose of delta-9-tetrahydrocannabinol (1.29%) in patients, most of whom were experiencing neuropathic pain despite conventional treatments, is a clinically significant outcome. In general, the effect sizes on cognitive testing were consistent with this minimal dose. As a result, one might not anticipate a significant impact on daily functioning. Published by Elsevier Inc.

  12. β-Hydroxy-β-methylbutyrate (HMB) prevents dexamethasone-induced myotube atrophy.

    Science.gov (United States)

    Aversa, Zaira; Alamdari, Nima; Castillero, Estibaliz; Muscaritoli, Maurizio; Rossi Fanelli, Filippo; Hasselgren, Per-Olof

    2012-07-13

    High levels of glucocorticoids result in muscle wasting and weakness. β-hydroxy-β-methylbutyrate (HMB) attenuates the loss of muscle mass in various catabolic conditions but the influence of HMB on glucocorticoid-induced muscle atrophy is not known. We tested the hypothesis that HMB prevents dexamethasone-induced atrophy in cultured myotubes. Treatment of cultured L6 myotubes with dexamethasone resulted in increased protein degradation and expression of atrogin-1 and MuRF1, decreased protein synthesis and reduced myotube size. All of these effects of dexamethasone were attenuated by HMB. Additional experiments provided evidence that the inhibitory effects of HMB on dexamethasone-induced increase in protein degradation and decrease in protein synthesis were regulated by p38/MAPK- and PI3K/Akt-dependent cell signaling, respectively. The present results suggest that glucocorticoid-induced muscle wasting can be prevented by HMB. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. 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)

  14. Dexamethasone Treatment Reverses Cognitive Impairment but Increases Brain Oxidative Stress in Rats Submitted to Pneumococcal Meningitis

    Directory of Open Access Journals (Sweden)

    Tatiana Barichello

    2011-01-01

    Full Text Available Pneumococcal meningitis is associated with a significant mortality rate and neurologic sequelae. The animals received either 10 μL of saline or a S. pneumoniae suspension and were randomized into different groups: sham: placebo with dexamethasone 0.7 mg/kg/1 day; placebo with dexamethasone 0.2 mg/kg/7 days; meningitis groups: dexamethasone 0.7 mg/kg/1 day and dexamethasone 0.2 mg/kg/7 days. Ten days after induction we evaluated memory and oxidative stress parameters in hippocampus and cortex. In the step-down inhibitory avoidance task, we observed memory impairment in the meningitis group with dexamethasone 0.2 mg/kg/7 days. The lipid peroxidation was increased in hippocampus in the meningitis groups with dexamethasone and in cortex only in the meningitis group with dexamethasone 0.2 mg/kg/7 days. The protein carbonyl was increased in hippocampus in the meningitis groups with dexamethasone and in cortex in the meningitis groups with and without dexamethasone. There was a decrease in the proteins integrity in hippocampus in all groups receiving treatment with dexamethasone and in cortex in all groups with dexamethasone (0.7 mg/kg/1 day. The mitochondrial superoxide was increased in the hippocampus and cortex in the meningitis group with dexamethasone 0.2 mg/kg/7 days. Our findings demonstrate that dexamethasone reverted cognitive impairment but increased brain oxidative stress in hippocampus and cortex in Wistar rats ten days after pneumococcal meningitis induction.

  15. Low Dose Vaporized Cannabis Significantly Improves Neuropathic Pain

    Science.gov (United States)

    Wilsey, Barth; Marcotte, Thomas D.; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

    2013-01-01

    We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling either medium dose (3.53%), low dose (1.29%), or placebo cannabis with the primary outcome being VAS pain intensity. Psychoactive side-effects, and neuropsychological performance were also evaluated. Mixed effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the two active dose groups’ results (p>0.7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo vs. low dose, 2.9 for placebo vs. medium dose, and 25 for medium vs. low dose. As these NNT are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being, for all intents and purposes, as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well-tolerated, and neuropsychological effects were of limited duration and readily reversible within 1–2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. PMID:23237736

  16. Low dose epidemiologic studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In this chapter the BEIR committee has reviewed low-dose irradiation studies since the BEIR III report. They have considered the carcinogenic effectiveness of low-LET in populations exposed to radiation from a number of different sources: diagnostic radiography; fallout from nuclear weapons testing; nuclear installations; radiation in the workplace and high levels of natural background radiation

  17. Low dose irradiation facilitates hepatocellular carcinoma genesis involving HULC.

    Science.gov (United States)

    Li, Yuan; Ge, Chang; Feng, Guoxing; Xiao, Huiwen; Dong, Jiali; Zhu, Changchun; Jiang, Mian; Cui, Ming; Fan, Saijun

    2018-03-24

    Irradiation exposure positive correlates with tumor formation, such as breast cancer and lung cancer. However, whether low dose irradiation induces hepatocarcinogenesis and the underlying mechanism remain poorly defined. In the present study, we reported that low dose irradiation facilitated the proliferation of hepatocyte through up-regulating HULC in vitro and in vivo. Low dose irradiation exposure elevated HULC expression level in hepatocyte. Deletion of heightened HULC erased the cells growth accelerated following low dose irradiation exposure. CDKN1, the neighbor gene of HULC, was down-regulated by overexpression of HULC following low dose irradiation exposure via complementary base pairing, resulting in promoting cell cycle process. Thus, our findings provide new insights into the mechanism of low dose irradiation-induced hepatocarcinogenesis through HULC/CDKN1 signaling, and shed light on the potential risk of low dose irradiation for the development of hepatocellular carcinoma in pre-clinical settings. © 2018 Wiley Periodicals, Inc.

  18. Low-dose effect on blood chromosomes

    International Nuclear Information System (INIS)

    Pohl-Rueling, J.

    1992-01-01

    Linear dose response relationships of biological effects at low doses are experimentally and theoretically disputed. Structural chromosome aberration rates at doses ranging from normal background exposures up to about 30 mGy/yr in vivo and up to 50 mGy in vitro were investigated by the author and other scientists. Results are comparable and dose effect curves reveal following shapes; within the normal burden and up to 2-10 mGy/yr in vivo rates they increase sharply to about 3-6 times the lowest values; subsequent doses either from natural, occupational or accidental exposures up to about 30 mGy/yr yield either constant aberration rates, assuming a plateau, or perhaps even a decrease. In vitro experiments show comparable results up to 50 mGy. Other biological effects seem to have similar dose dependencies. The non-linearity of low-dose effects can be explained by induction of repair enzymes at certain damage to the DNA. This hypothesis is sustained experimentally and theoretically by several papers in literature. (author). 14 refs., 5 figs

  19. Pregabalin and dexamethasone improves post-operative pain treatment after tonsillectomy

    DEFF Research Database (Denmark)

    Mathiesen, O; Jørgensen, D G; Hilsted, K L

    2011-01-01

    Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy.......Post-tonsillectomy pain can be severe. We investigated the analgesic effect from combinations of paracetamol, pregabalin and dexamethasone in adults undergoing tonsillectomy....

  20. Risk of radiation-induced cancer at low doses and low dose rates for radiation protection purposes

    International Nuclear Information System (INIS)

    1995-01-01

    The aim of this report is to provide an updated, comprehensive review of the data available for assessing the risk of radiation-induced cancer for radiation protection purposes. Particular emphasis is placed on assessing risks at low doses and low dose rates. The review brings together the results of epidemiological investigations and fundamental studies on the molecular and cellular mechanisms involved in radiation damage. Additionally, this information is supplemented by studies with experimental animals which provide further guidance on the form of the dose-response relationship for cancer induction, as well as on the effect of dose rate on the tumour yield. The emphasis of the report is on cancer induction resulting from exposure to radiations with a low linear energy transfer (LET). The work was performed under contract for the Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses, Paris, France, whose agreement to publish is gratefully ackowledged. It extends the advice on radiation risks given in Documents of the NRPB, 4 No. 4 (1993). (Author)

  1. Patient dose in neonatal units

    International Nuclear Information System (INIS)

    Smans, K.; Struelens, L.; Smet, M.; Bosmans, H.; Vanhavere, F.

    2008-01-01

    Lung disease represents one of the most life-threatening conditions in prematurely born children. In the evaluation of the neonatal chest, the primary and most important diagnostic study is therefore the chest radiograph. Since prematurely born children are very sensitive to radiation, those radiographs may lead to a significant radiation detriment. Hence, knowledge of the patient dose is necessary to justify the exposures. A study to assess the patient doses was started at the neonatal intensive care unit (NICU) of the Univ. Hospital in Leuven. Between September 2004 and September 2005, prematurely born babies underwent on average 10 X-ray examinations in the NICU. In this sample, the maximum was 78 X-ray examinations. For chest radiographs, the median entrance skin dose was 34 μGy and the median dose area product was 7.1 mGy.cm 2 . By means of conversion coefficients, the measured values were converted to organ doses. Organ doses were calculated for three different weight classes: extremely low birth weight infants ( 2500 g). The doses to the lungs for a single chest radiograph for infants with extremely low birth weights, low birth weights and normal birth weights were 24, 25 and 32 μGy, respectively. (authors)

  2. Dexamethasone Modifies Cystatin C-Based Diagnosis of Acute Kidney Injury During Cisplatin-Based Chemotherapy

    Directory of Open Access Journals (Sweden)

    Timothy J. Pianta

    2017-03-01

    Full Text Available Background/Aims: Plasma cystatin C (pCysC may be superior to serum creatinine (sCr as a surrogate of GFR. However, the performance of pCysC for diagnosing acute kidney injury (AKI after cisplatin-based chemotherapy is potentially affected by accompanying corticosteroid anti-emetic therapy and hydration. Methods: In a prospective observational study pCysC, sCr, urinary kidney injury molecule-1 (KIM-1, and urinary clusterin were measured over 2 weeks in 27 patients given first-cycle chemotherapy. The same variables were measured over 2 weeks in Sprague–Dawley rats given a single intraperitoneal injection of dexamethasone, cisplatin, or both, and in controls. Results: In patients, pCysC increases were greater than sCr 41% vs. 16%, mean paired difference 25% (95% CI: 16–34%], relative increases were ≥ 50% in 9 patients (35% for pCysC compared with 2 (8% for sCr (p = 0.04 and increases in sCr were accompanied by increased KIM-1 and clusterin excretion, but increases in pCysC alone were not. In rats, dexamethasone administration produced dose-dependent increases in pCysC (and augmented cisplatin-induced increases in pCysC, but did not augment histological injury, increases in sCr, or KIM-1 and clusterin excretion. Conclusions: In the presence of dexamethasone, elevation of pCysC does not reliably diagnose AKI after cisplatin-based chemotherapy.

  3. Low doses of gamma radiation in soybean

    International Nuclear Information System (INIS)

    Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C.; Arthur, Valter; Arthur, Paula B.; Franco, Caio H.

    2017-01-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  4. Low doses of gamma radiation in soybean

    Energy Technology Data Exchange (ETDEWEB)

    Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

    2017-07-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  5. Microdose acquisition in adolescent leg length discrepancy using a low-dose biplane imaging system.

    Science.gov (United States)

    Jensen, Janni; Mussmann, Bo R; Hjarbæk, John; Al-Aubaidi, Zaid; Pedersen, Niels W; Gerke, Oke; Torfing, Trine

    2017-09-01

    Background Children with leg length discrepancy often undergo repeat imaging. Therefore, every effort to reduce radiation dose is important. Using low dose preview images and noise reduction software rather than diagnostic images for length measurements might contribute to reducing dose. Purpose To compare leg length measurements performed on diagnostic images and low dose preview images both acquired using a low-dose bi-planar imaging system. Material and Methods Preview and diagnostic images from 22 patients were retrospectively collected (14 girls, 8 boys; mean age, 12.8 years; age range, 10-15 years). All images were anonymized and measured independently by two musculoskeletal radiologists. Three sets of measurements were performed on all images; the mechanical axis lines of the femur and the tibia as well as the anatomical line of the entire extremity. Statistical significance was tested with a paired t-test. Results No statistically significant difference was found between measurements performed on the preview and on the diagnostic image. The mean tibial length difference between the observers was -0.06 cm (95% confidence interval [CI], -0.12 to 0.01) and -0.08 cm (95% CI, -0.21 to 0.05), respectively; 0.10 cm (95% CI, 0.02-0.17) and 0.06 cm (95% CI, -0.02 to 0.14) for the femoral measurements and 0.12 cm (95% CI, -0.05 to 0.26) and 0.08 cm (95% CI, -0.02 to 0.19) for total leg length discrepancy. ICCs were >0.99 indicating excellent inter- and intra-rater reliability. Conclusion The data strongly imply that leg length measurements performed on preview images from a low-dose bi-planar imaging system are comparable to measurements performed on diagnostic images.

  6. Microdose acquisition in adolescent leg length discrepancy using a low-dose biplane imaging system

    DEFF Research Database (Denmark)

    Jensen, Janni; Mussmann, Bo Redder; Hjarbæk, John

    2017-01-01

    To compare leg length measurements performed on diagnostic images and low dose preview images both acquired using a low-dose bi-planar imaging system. Material and Methods Preview and diagnostic images from 22 patients were retrospectively collected (14 girls, 8 boys; mean age, 12.8 years; age range, 10......-15 years). All images were anonymized and measured independently by two musculoskeletal radiologists. Three sets of measurements were performed on all images; the mechanical axis lines of the femur and the tibia as well as the anatomical line of the entire extremity. Statistical significance was tested...... with a paired t-test. Results No statistically significant difference was found between measurements performed on the preview and on the diagnostic image. The mean tibial length difference between the observers was -0.06 cm (95% confidence interval [CI], -0.12 to 0.01) and -0.08 cm (95% CI, -0.21 to 0...

  7. Paradoxical response to dexamethasone and spontaneous hypocortisolism in Cushing's disease

    Science.gov (United States)

    Lila, Anurag R; Sarathi, Vijaya; Bandgar, Tushar R; Shah, Nalini S

    2013-01-01

    Paradoxical response to dexamethasone and spontaneous development of hypocortisolism are rare features of Cushing's disease. We report a 13-year-old boy with Cushing's disease owing to a pituitary macroadenoma. On initial evaluation, he had partial suppression of serum cortisol by dexamethasone. He developed transient hypocortisolism after first adenomectomy, but the disease recurred after 1 year. Repeat evaluation showed recurrent hypercortisolism and paradoxical response to dexamethasone. He underwent second surgery and, postoperatively, hypercostisolism persisted even after 2 years of surgery. Repeat evaluations after 8 years of second surgery revealed persistent hypocortisolism despite residual tumour of same size and similar plasma adrenocorticotropic hormone (ACTH) levels. We have also shown that the paradoxical increase in serum cortisol was preceded by a paradoxical increase in ACTH. The paradoxical response persisted despite hypocortisolism. This patient with Cushing's disease had two very rare features: paradoxical response to dexamethasone and spontaneous development of hypocortisolism. PMID:23365169

  8. Adaptive statistical iterative reconstruction use for radiation dose reduction in pediatric lower-extremity CT: impact on diagnostic image quality.

    Science.gov (United States)

    Shah, Amisha; Rees, Mitchell; Kar, Erica; Bolton, Kimberly; Lee, Vincent; Panigrahy, Ashok

    2018-06-01

    For the past several years, increased levels of imaging radiation and cumulative radiation to children has been a significant concern. Although several measures have been taken to reduce radiation dose during computed tomography (CT) scan, the newer dose reduction software adaptive statistical iterative reconstruction (ASIR) has been an effective technique in reducing radiation dose. To our knowledge, no studies are published that assess the effect of ASIR on extremity CT scans in children. To compare radiation dose, image noise, and subjective image quality in pediatric lower extremity CT scans acquired with and without ASIR. The study group consisted of 53 patients imaged on a CT scanner equipped with ASIR software. The control group consisted of 37 patients whose CT images were acquired without ASIR. Image noise, Computed Tomography Dose Index (CTDI) and dose length product (DLP) were measured. Two pediatric radiologists rated the studies in subjective categories: image sharpness, noise, diagnostic acceptability, and artifacts. The CTDI (p value = 0.0184) and DLP (p value ASIR compared with non-ASIR studies. However, the subjective ratings for sharpness (p ASIR images (p ASIR CT studies. Adaptive statistical iterative reconstruction reduces radiation dose for lower extremity CTs in children, but at the expense of diagnostic imaging quality. Further studies are warranted to determine the specific utility of ASIR for pediatric musculoskeletal CT imaging.

  9. Extremely low frequency magnetic fields and health risks

    Directory of Open Access Journals (Sweden)

    M.I. Buzdugan

    2009-10-01

    Full Text Available In a world abounding in artificially created electromagnetic fields, we consider that a new approach regarding their possible harmful effects on living beings becomes mandatory. The paper reviews briefly the results of some epidemiological studies, the ICNIRP (International Committee on Non-Ionizing Radiation Protection Guidelines and the latest document of the SCENIHR (an organism of the European Commission regarding extremely low frequency (ELF magnetic fields. We are convinced that the best conduct that might be adopted on this matter is the policy of the prudential avoidance. Several examples of possible harmful effects determined by extremely low frequency magnetic fields dedicated to building services engineering in residences are presented, along with several methods of mitigating them.

  10. Carfilzomib, lenalidomide, and dexamethasone for relapsed multiple myeloma.

    Science.gov (United States)

    Stewart, A Keith; Rajkumar, S Vincent; Dimopoulos, Meletios A; Masszi, Tamás; Špička, Ivan; Oriol, Albert; Hájek, Roman; Rosiñol, Laura; Siegel, David S; Mihaylov, Georgi G; Goranova-Marinova, Vesselina; Rajnics, Péter; Suvorov, Aleksandr; Niesvizky, Ruben; Jakubowiak, Andrzej J; San-Miguel, Jesus F; Ludwig, Heinz; Wang, Michael; Maisnar, Vladimír; Minarik, Jiri; Bensinger, William I; Mateos, Maria-Victoria; Ben-Yehuda, Dina; Kukreti, Vishal; Zojwalla, Naseem; Tonda, Margaret E; Yang, Xinqun; Xing, Biao; Moreau, Philippe; Palumbo, Antonio

    2015-01-08

    Lenalidomide plus dexamethasone is a reference treatment for relapsed multiple myeloma. The combination of the proteasome inhibitor carfilzomib with lenalidomide and dexamethasone has shown efficacy in a phase 1 and 2 study in relapsed multiple myeloma. We randomly assigned 792 patients with relapsed multiple myeloma to carfilzomib with lenalidomide and dexamethasone (carfilzomib group) or lenalidomide and dexamethasone alone (control group). The primary end point was progression-free survival. Progression-free survival was significantly improved with carfilzomib (median, 26.3 months, vs. 17.6 months in the control group; hazard ratio for progression or death, 0.69; 95% confidence interval [CI], 0.57 to 0.83; P=0.0001). The median overall survival was not reached in either group at the interim analysis. The Kaplan-Meier 24-month overall survival rates were 73.3% and 65.0% in the carfilzomib and control groups, respectively (hazard ratio for death, 0.79; 95% CI, 0.63 to 0.99; P=0.04). The rates of overall response (partial response or better) were 87.1% and 66.7% in the carfilzomib and control groups, respectively (P<0.001; 31.8% and 9.3% of patients in the respective groups had a complete response or better; 14.1% and 4.3% had a stringent complete response). Adverse events of grade 3 or higher were reported in 83.7% and 80.7% of patients in the carfilzomib and control groups, respectively; 15.3% and 17.7% of patients discontinued treatment owing to adverse events. Patients in the carfilzomib group reported superior health-related quality of life. In patients with relapsed multiple myeloma, the addition of carfilzomib to lenalidomide and dexamethasone resulted in significantly improved progression-free survival at the interim analysis and had a favorable risk-benefit profile. (Funded by Onyx Pharmaceuticals; ClinicalTrials.gov number, NCT01080391.).

  11. Lateral topography for reducing effective dose in low-dose chest CT.

    Science.gov (United States)

    Bang, Dong-Ho; Lim, Daekeon; Hwang, Wi-Sub; Park, Seong-Hoon; Jeong, Ok-man; Kang, Kyung Wook; Kang, Hohyung

    2013-06-01

    The purposes of this study were to assess radiation exposure during low-dose chest CT by using lateral topography and to compare the lateral topographic findings with findings obtained with anteroposterior topography alone and anteroposterior and lateral topography combined. From November 2011 to February 2012, 210 male subjects were enrolled in the study. Age, weight, and height of the men were recorded. All subjects were placed into one of three subgroups based on the type of topographic image obtained: anteroposterior topography, lateral topography, and both anteroposterior and lateral topography. Imaging was performed with a 128-MDCT scanner. CT, except for topography, was the same for all subjects. A radiologist analyzed each image, recorded scan length, checked for any insufficiencies in the FOV, and calculated the effective radiation dose. One-way analysis of variance and multiple comparisons were used to compare the effective radiation exposure and scan length between groups. The mean scan length in the anteroposterior topography group was significantly greater than that of the lateral topography group and the combined anteroposterior and lateral topography group (p topography group (0.735 ± 0.033 mSv) was significantly lower than that for the anteroposterior topography group (0.763 ± 0.038 mSv) and the combined anteroposterior and lateral topography group (0.773 ± 0.038) (p < 0.001). Lateral topographic low-dose CT was associated with a lower effective radiation dose and scan length than either anteroposterior topographic low-dose chest CT or low-dose chest CT with both anteroposterior and lateral topograms.

  12. Effects of low dose radiation and epigenetic regulation

    International Nuclear Information System (INIS)

    Jiao Benzheng; Ma Shumei; Yi Heqing; Kong Dejuan; Zhao Guangtong; Gao Lin; Liu Xiaodong

    2010-01-01

    Purpose: To conclude the relationship between epigenetics regulation and radiation responses, especially in low-dose area. Methods: The literature was examined for papers related to the topics of DNA methylation, histone modifications, chromatin remodeling and non-coding RNA modulation in low-dose radiation responses. Results: DNA methylation and radiation can regulate reciprocally, especially in low-dose radiation responses. The relationship between histone methylation and radiation mainly exists in the high-dose radiation area; histone deacetylase (HDAC) inhibitors show a promising application to enhance radiation sensitivity, no matter whether in low-dose or high-dose areas; the connection between γ-H2AX and LDR has been remained unknown, although γ-H2AX has been shown no radiation sensitivities with 1-15 Gy irradiation; histone ubiquitination play an important role in DNA damage repair mechanism. Moreover, chromatin remodeling has an integral role in DSB repair and the chromatin response, in general, may be precede DNA end resection. Finally, the effect of radiation on miRNA expression seems to vary according to cell type, radiation dose, and post-irradiation time point. Conclusion: Although the advance of epigenetic regulation on radiation responses, which we are managing to elucidate in this review, has been concluded, there are many questions and blind blots deserved to investigated, especially in low-dose radiation area. However, as progress on epigenetics, we believe that many new elements will be identified in the low-dose radiation responses which may put new sights into the mechanisms of radiation responses and radiotherapy. (authors)

  13. Adverse effects of parenteral dexamethasone in the treatment of pemphigus vulgaris

    Directory of Open Access Journals (Sweden)

    Mohammad Jamal Uddin

    2016-08-01

    Full Text Available Background: Pemphigus vulgaris is associated with high morbidity as well as significant mortality rate. Today the risk of death in pemphigus from the side effect of oral prednisolone is greater than risk of death from the disease itself. Objec­tive: To observe the adverse effects of parenteral dexamethasone compared with oral prednisolone in the treatment of pemphigus vulgaris. Methods: An interventional study was carried out in the department of Dermatology and Venereol­ogy, Bangabandu Sheikh Mujib Medical University, Dhaka, Bangladesh. Total number of patients was thirty and among them fifteen patients were treated with parenteral dexamethasone (Group-A and other fifteen were treated with oral prednisolone (Group-B. Results: The study showed statistically significant differences of skin lesion as well as mucosal lesion of pemphigus after 6 weeks of therapy between of two groups (P<0.05. The most common adverse effects were increased body weight(40%, increased appetite(40%, and puffy face(40% in dexamethasone group. In prednisolone group, these side effects were 60% of the subjects. Other side effects in dexamethasone group were hyperglycemia (33.33%, hypertension (26.66%, and sleep disturbance (13.33%. In prednisolone group, other side effects were hyperglycemia(33.33%, hypertension(40%, gastritis (33.33%, nausea, vomiting (13.33% in each , reactivation of tuberculosis, herpes zoster infection, sleep disturbance, and mood change were 6.66% in each group. Conclusion: In the light of the findings of the study, we conclude that each of the treatment of dexamethasone group and prednisolone group is individually effective and safe in the treatment of pemphigus vulgaris but adverse effects are less in parenteral dexamethasone group than oral prednisolone group. So parenteral dexamethasone can be used as an alternative drug in the treatment of pemphigus vulgaris.

  14. Dexamethasone as adjuvant therapy in the treatment of invasive meningococcal diseases.

    Science.gov (United States)

    Tolaj, Ilir; Dreshaj, Shemsedin; Qehaja, Emine; Tolaj, Jasmina; Doda-Ejupi, Teuta; Mehmeti, Murat

    2010-01-01

    With this study we want to evaluate the role of dexamethasone adjuvant treatment in different clinical forms of invasive meningococcal diseases. WORK METHODS: This was a randomized, open label trial that was conducted in 147 individuals with meningococcal sepsis. All of the cases have been divided in two groups: (1) Cases with meningococcal disease and CNS infection, and (2) Cases with meningococcal disease and no affection of the CNS. Cases from both groups were treated with dexamethasone, 0.15 mg/kg, every 6 h, for 4 (four) days, as adjuvant therapy. Cases which were not treated with dexamethasone were used as control group. From overall number of cases, in 130 of them, the meningococcal disease was accompanied with meningitis; in other 17 cases only signs of sepsis were present. In both clinical forms, the dexamethasone was used in 92 cases. The higher mortality rate is registered among the cases without meningitis, 17.65%, compared with 6.92% which is registered among cases with meningitis. The overall mortality rate among all cases was 8.2%. The significant difference was recorded only on CSF sugar level between two groups (treated or not with dexamethasone) on the day 1-4 of the hospitalization. Our epidemiological data are in correlation with data from other epidemiological studies. Most of the cases 69.4%, were more than 12 hours sick at home before the hospitalization, 7.5 % of cases were hospitalized within 12 hours from the onset of the diseases, while 23.1% of cases data are missing. This is in correlation with similar data from other studies. Dexamethasone has a limited effect on outcome of the invasive meningococcal disease. Dexamethasone had some effect only during the days of administration in cases with clinical form of sepsis with meningitis, by normalizing the values of CSF sugar earlier.

  15. Biochemical and cellular mechanisms of low-dose effects

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; Booz, J.; Muehlensiepen, H.

    1988-01-01

    The question of health effects from small radiation doses remains open. Individual cells, when being hit by single elemental doses - in low-dose irradiation - react acutely and temporarily by altering control of enzyme activity, as is demonstrated for the case of thymidine kinase. This response is not constant in that it provides a temporary protection of enzyme activity against a second irradiation, by a mechanism likely to be via improved detoxification of intracellular radicals. It must be considered that in the low-dose region radiation may also exert protection against other challenges involving radicals, causing a net beneficial effect by temporarily shielding the hit cell against radicals produced by metabolism. Since molecular alterations leading to late effects are considered a consequence of the initial cellular response, late effects from small radiation doses do not necessarily adhere to a linear dose-effect relationship. The reality of the linear relationship between the risk of late effects from high doses to small doses is an assumption, for setting dose limits, but it must not be taken for predicting health detriment from low doses. (author)

  16. Induction of regulatory dendritic cells by dexamethasone and 1alpha,25-Dihydroxyvitamin D(3)

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Gad, Monika; Walter, Mark R

    2004-01-01

    D(3) the active form of Vitamin D(3) (D(3)) in combination with dexamethasone (Dex) has a synergistic effect on LPS-induced maturation of DC. Monocyte-derived DCs cultured with D(3) and Dex during LPS-induced maturation have a low stimulatory effect on allogeneic T cells comparable...

  17. Systemic effects of low-dose dopamine during administration of cytarabine.

    Science.gov (United States)

    Connelly, James; Benani, Dina J; Newman, Matthew; Burton, Bradley; Crow, Jessica; Levis, Mark

    2017-09-01

    Purpose Low-dose dopamine has been utilized to improve renal blood flow, urine output, and reduce drug-induced nephrotoxicity. The purpose of this study was to assess changes in renal function, cardiovascular adverse events, and neurologic toxicity in patients receiving cytarabine with or without low-dose dopamine. Methods A retrospective, single-center, cohort study of patients receiving cytarabine at 667 mg/m 2 /dose or greater, with or without dopamine at ≤5 mcg/kg/min. Cohorts were based upon initiation or absence of low-dose dopamine; cytarabine only, cytarabine + pre- and day of low-dose dopamine, and cytarabine + post-low-dose dopamine. Renal outcomes (urine output, serum creatinine, and creatinine clearance) were compared with baseline and between cohorts. Safety endpoints (arrhythmias, tachycardia, and neurotoxicity) were compared between cohorts based on low-dose dopamine exposure. Results There was no difference in urine output from baseline in all cohorts. Comparing cytarabine only and pre- and day of low-dose dopamine cohorts, there was no difference in urine output. In those receiving low-dose dopamine, there was no difference in serum creatinine and creatinine clearance from baseline. No arrhythmias were documented during the study period, and there was no difference in the incidence of tachycardia between groups (P = 0.66). Neurotoxicity was reported in three patients who were on low-dose dopamine. Conclusion Though variation existed in individual patients administered low-dose dopamine, the use of low-dose dopamine did not significantly impact renal function in this small sample at a single institution. In addition, low-dose dopamine did not negatively impact cardiovascular function.

  18. Reduced oxygen enhancement ratio at low doses

    International Nuclear Information System (INIS)

    Palcic, B.; Skarsgard, L.D.

    1984-01-01

    The oxygen depletion rate in cell suspensions was measured using a Clark electrode. It was found that under experimental conditions used in this laboratory for hypoxic irradiations, the oxygen levels before the start of irradiation are always below 0.1μm, the levels which could give any significant enhancement to radiation inactivation by x-rays. The measured O/sub 2/ depletion rates were comparable to those reported in the literature. Chinese hamster cells (CHO) were made hypoxic by gas exchange, combined with metabolic consumption of oxygen by cells at 37 0 C. Full survival curves were determined in the dose range 0 to 3Gy using the low dose survival assay. The results confirmed the authors' earlier finding that the OER decreases at low doses. The authors therefore believe that the dose-dependent OER is a true radiobiological phenomenon and not an artifact of the experimental method used in the low dose survival assay

  19. Dose Response Model of Biological Reaction to Low Dose Rate Gamma Radiation

    International Nuclear Information System (INIS)

    Magae, J.; Furikawa, C.; Hoshi, Y.; Kawakami, Y.; Ogata, H.

    2004-01-01

    It is necessary to use reproducible and stable indicators to evaluate biological responses to long term irradiation at low dose-rate. They should be simple and quantitative enough to produce the results statistically accurate, because we have to analyze the subtle changes of biological responses around background level at low dose. For these purposes we chose micronucleus formation of U2OS, a human osteosarcoma cell line, as indicators of biological responses. Cells were exposed to gamma ray in irradiation rom bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide, respectively. the number of binuclear cells bearing micronuclei was counted under a fluorescence microscope. Dose rate in the irradiation room was measured with PLD. Dose response of PLD is linear between 1 mGy to 10 Gy, and standard deviation of triplicate count was several percent of mean value. We fitted statistically dose response curves to the data, and they were plotted on the coordinate of linearly scale response and dose. The results followed to the straight line passing through the origin of the coordinate axes between 0.1-5 Gy, and dose and does rate effectiveness factor (DDREF) was less than 2 when cells were irradiated for 1-10 min. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose above 0.1 Gy when 5,000 binuclear cells were analyzed. In contrast, dose response curves never followed LNT, when cells were irradiated for 7 to 124 days. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose below 6 Gy, when cells were continuously irradiated for 124 days. These results suggest that dose response curve of biological reaction is remarkably affected by exposure

  20. Low dose radiation enhance the anti-tumor effect of high dose radiation on human glioma cell U251

    International Nuclear Information System (INIS)

    Wang Chang; Wang Guanjun; Tan Yehui; Jiang Hongyu; Li Wei

    2008-01-01

    Objective: To detect the effect on the growth of human glioma cell U251 induced by low dose irradiation and low dose irradiation combined with large dose irradiation. Methods: Human glioma cell line U251 and nude mice carried with human glioma were used. The tumor cells and the mice were treated with low dose, high dose, and low dose combined high dose radiation. Cells growth curve, MTT and flow cytometry were used to detect the proliferation, cell cycle and apoptosis of the cells; and the tumor inhibition rate was used to assess the growth of tumor in vivo. Results: After low dose irradiation, there was no difference between experimental group and control group in cell count, MTT and flow cytometry. Single high dose group and low dose combined high dose group both show significantly the suppressing effect on tumor cells, the apoptosis increased and there was cell cycle blocked in G 2 period, but there was no difference between two groups. In vivo apparent anti-tumor effect in high dose radiation group and the combining group was observed, and that was more significant in the combining group; the prior low dose radiation alleviated the injury of hematological system. There was no difference between single low dose radiation group and control. Conclusions: There is no significant effect on human glioma cell induced by low dose radiation, and low dose radiation could not induce adaptive response. But in vivo experience, low dose radiation could enhance the anti-tumor effect of high dose radiation and alleviated the injury of hematological system. (authors)

  1. β-Hydroxy-β-methylbutyrate (HMB normalizes dexamethasone-induced autophagy-lysosomal pathway in skeletal muscle.

    Directory of Open Access Journals (Sweden)

    María D Girón

    Full Text Available Dexamethasone-induced muscle atrophy is due to an increase in protein breakdown and a decrease in protein synthesis, associated with an over-stimulation of the autophagy-lysosomal pathway. These effects are mediated by alterations in IGF-1 and PI3K/Akt signaling. In this study, we have investigated the effects of β-Hydroxy-β-methylbutyrate (HMB on the regulation of autophagy and proteosomal systems. Rats were treated during 21 days with dexamethasone as a model of muscle atrophy. Co-administration of HMB attenuated the effects promoted by dexamethasone. HMB ameliorated the loss in body weight, lean mass and the reduction of the muscle fiber cross-sectional area (shrinkage in gastrocnemius muscle. Consequently, HMB produced an improvement in muscle strength in the dexamethasone-treated rats. To elucidate the molecular mechanisms responsible for these effects, rat L6 myotubes were used. In these cells, HMB significantly attenuated lysosomal proteolysis induced by dexamethasone by normalizing the changes observed in autophagosome formation, LC3 II, p62 and Bnip3 expression after dexamethasone treatment. HMB effects were mediated by an increase in FoxO3a phosphorylation and concomitant decrease in FoxO transcriptional activity. The HMB effect was due to the restoration of Akt signaling diminished by dexamethasone treatment. Moreover, HMB was also involved in the regulation of the activity of ubiquitin and expression of MurF1 and Atrogin-1, components of the proteasome system that are activated or up-regulated by dexamethasone. In conclusion, in vivo and in vitro studies suggest that HMB exerts protective effects against dexamethasone-induced muscle atrophy by normalizing the Akt/FoxO axis that controls autophagy and ubiquitin proteolysis.

  2. β-Hydroxy-β-methylbutyrate (HMB) normalizes dexamethasone-induced autophagy-lysosomal pathway in skeletal muscle.

    Science.gov (United States)

    Girón, María D; Vílchez, Jose D; Shreeram, Sathyavageeswaran; Salto, Rafael; Manzano, Manuel; Cabrera, Elena; Campos, Nefertiti; Edens, Neile K; Rueda, Ricardo; López-Pedrosa, Jose M

    2015-01-01

    Dexamethasone-induced muscle atrophy is due to an increase in protein breakdown and a decrease in protein synthesis, associated with an over-stimulation of the autophagy-lysosomal pathway. These effects are mediated by alterations in IGF-1 and PI3K/Akt signaling. In this study, we have investigated the effects of β-Hydroxy-β-methylbutyrate (HMB) on the regulation of autophagy and proteosomal systems. Rats were treated during 21 days with dexamethasone as a model of muscle atrophy. Co-administration of HMB attenuated the effects promoted by dexamethasone. HMB ameliorated the loss in body weight, lean mass and the reduction of the muscle fiber cross-sectional area (shrinkage) in gastrocnemius muscle. Consequently, HMB produced an improvement in muscle strength in the dexamethasone-treated rats. To elucidate the molecular mechanisms responsible for these effects, rat L6 myotubes were used. In these cells, HMB significantly attenuated lysosomal proteolysis induced by dexamethasone by normalizing the changes observed in autophagosome formation, LC3 II, p62 and Bnip3 expression after dexamethasone treatment. HMB effects were mediated by an increase in FoxO3a phosphorylation and concomitant decrease in FoxO transcriptional activity. The HMB effect was due to the restoration of Akt signaling diminished by dexamethasone treatment. Moreover, HMB was also involved in the regulation of the activity of ubiquitin and expression of MurF1 and Atrogin-1, components of the proteasome system that are activated or up-regulated by dexamethasone. In conclusion, in vivo and in vitro studies suggest that HMB exerts protective effects against dexamethasone-induced muscle atrophy by normalizing the Akt/FoxO axis that controls autophagy and ubiquitin proteolysis.

  3. Detection of lung nodules with low-dose spiral CT: comparison with conventional dose CT

    International Nuclear Information System (INIS)

    Zhu Tianzhao; Tang Guangjian; Jiang Xuexiang

    2004-01-01

    Objective: To investigate the effect of reducing scan dose on the lung nodules detection rate by scanning a lung nodule model at low dose and conventional dose. Methods: The lung and the thoracic cage were simulated by using a cyst filled with water surrounded by a roll bandage. Flour, butter, and paraffin wax were mixed together by a certain ratio to simulate lung nodules of 10 mm and 5 mm in diameter with the CT values ranging from -10 to 50 HU. Conventional-dose scan (240 mA, 140 kV) and low-dose scan of three different levels (43 mA, 140 kV; 50 mA, 120 kV; 75 mA, 80 kV) together with three different pitches (1.0, 1.5, and 2.0) were performed. The images of the simulated nodules were combined with the CT images of a normal adult's upper, middle, and inferior lung. Three radiologists read the images and the number of the nodules they detected including both the real ones and the false-positive ones was calculated to investigate weather there was any difference among different doses, pitch groups, and different locations. Results: The detection rate of the 10 mm and 5 mm nodules was 100% and 89.6% respectively by the low-dose scan. There was no difference between low-dose and conventional-dose CT (χ 2 =0.6907, P>0.70). The detection rate of 5 mm nodules declined when large pitch was used. Conclusion: The detection rates of 10 mm and 5 mm nodules had no difference between low-dose CT and conventional-dose CT. As the pitch augmented, the detection rate for the nodules declined

  4. Mutation process at low or high radiation doses

    International Nuclear Information System (INIS)

    Abrahamson, S.; Wisconsin Univ., Madison

    1976-01-01

    A concise review is given of the status of research on the genetic effects of low-level radiation in general. The term ''low dose'' is defined and current theories on low dose are set out. Problems and their solutions are discussed. (author)

  5. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

    2009-01-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  6. Comparison of hyperuricemia in type 2 diabetics on low dose aspirin and not on low dose aspirin

    International Nuclear Information System (INIS)

    Malik, M.I.

    2013-01-01

    Objective: To compare the frequency of hyperuricemia in type 2 diabetes patients who are taking low dose aspirin with those patients who are not taking low dose aspirin. Study design: Quasi experimental study. Place and duration of study: This study was carried out at Military Hospital Rawalpindi for a period of two years (June 2006-May 2008). Patients and Methods: Sixty diabetic patients were selected who were taking low dose aspirin comparing group A and sixty diabetic patients who were not taking aspirin were placed in group B. These patients were selected from the OPD through non probability convenience sampling. All these patients were being followed up in medical outpatient quite regularly on fort-nightly basis. Data had been collected through a carefully designed questionnaire. Results: In group A, 90% of the patients had uric acid less than 445 micro mol/l and 10% of the patients had uric acid more than 445micro mol/l. Whereas in group B 100% of the patients had uric acid less than 445umol/l, there was a statistically significant difference between the two groups (p< 0.05). Conclusion: Aspirin in low doses cause hyperuricemia and regular monitoring of uric acid is mandatory to prevent its adverse effects. (author)

  7. Determination of photon conversion factors relating exposure and dose for several extremity phantom designs

    International Nuclear Information System (INIS)

    Roberson, P.L.; Eichner, F.N.; Reece, W.D.

    1986-09-01

    This report presents the results of measurements of dosimetric properties of simple extremity phantoms suitable for use in extremity dosimeter performance testing. Two sizes of phantoms were used in this study. One size represented the forearm or lower leg and the other size represented the finger or toe. For both phantom sizes, measurements were performed on solid plastic phantoms and on phantoms containing simulated bone material to determine the effect of backscattered radiations from the bone on the surface dose. Exposure-to-dose conversion factors (C/sub x/ factors) were determined for photon energies ranging from 16 to 1250 keV (average for 60 Co). The effect of the presence of a phantom was also measured for a 90 Sr/ 90 Y source. Significant differences in the measured C/sub x/ factors were found among the phantoms investigated. The factors for the finger-sized phantoms were uniformly less than for the arm-sized phantoms

  8. Is there any role for terlipressin in the extremely low birth weight infant with refractory septic shock?

    Directory of Open Access Journals (Sweden)

    Francesca Bissolo

    2012-10-01

    Full Text Available Terlipressin, a synthetic long-acting analogue of vasopressin, has been investigated as a second line vasopressor in adults and children with refractory septic shock, i.e. not responding to fluid resuscitation and high-dose catecholamine administration. Little experience is available about the safety and efficacy of terlipressin in term and preterm newborns. We report the case of an extremely low birth weight infant with severe septic shock, unresponsive to fluids, noradrenalin and hydrocortisone, in whom terlipressin was attempted as a rescue drug. Despite three doses of terlipressin, administered 6-hourly, the patient remained profoundly hypotensive and eventually died. Further studies are required before any recommendation on the use of terlipressin in term or preterm newborns with septic shock can be made.

  9. Intravitreal clindamycin and dexamethasone for toxoplasmic retinochoroiditis.

    Science.gov (United States)

    Kishore, K; Conway, M D; Peyman, G A

    2001-01-01

    To present a new method for the management of toxoplasmic retinochoroiditis (TRC). The patients were females ranging in age from 10 to 61 years (average 26.5). Four eyes of 4 patients were treated with intravitreal injections of 1.0 mg clindamycin in 0.1 mL and 1.0 mg of dexamethasone in 0.1 mL. The injections were given under general or peribulbar anesthesia. Three patients continued one systemic drug. Follow-up ranged from 11 to 26 months (mean 17.5). A favorable response was noted in each eye within two weeks after the intravitreal injections. All patients required 2 to 4 intravitreal injections in the affected eye for the control of TRC. Visual acuity improved in each eye. The disc and macula were preserved in all eyes. Recurrence was noted in one case, which responded to a repeated intravitreal injection of clindamycin and dexamethasone. Intravitreal injections of clindamycin and dexamethasone are well tolerated and may offer an additional strategy to treat TRC in patients who are unable to afford or tolerate systemic therapy, or whose disease progresses despite systemic therapy.

  10. Low dose radiation exposure and atherosclerosis in ApoE{sup -/-} mice

    Energy Technology Data Exchange (ETDEWEB)

    Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Hasu, M. [Univ. of Ottawa, Department of Pathology and Lab. Medicine, and Cellular and Molecular Medicine, Ottawa, ON (Canada); Univ. of Ottawa Heart Inst., Vascular Biology Group, Ottawa, ON (Canada); Bugden, M.; Wyatt, H. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Little, M. [Imperial Coll., Faculty of Medicine, St. Marys Campus, London (United Kingdom); Hildebrandt, G. [Univ. Hospital, Dept. of Radiotherapy, Rostock (Germany); Priest, N.D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada); Whitman, S.C. [Univ. of Ottawa, Department of Pathology and Lab. Medicine, and Cellular and Molecular Medicine, Ottawa, ON (Canada); Univ. of Ottawa Heart Inst., Vascular Biology Group, Ottawa, ON (Canada)

    2010-07-01

    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)

  11. 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

  12. Regulatory aspects of low doses control in Albania

    International Nuclear Information System (INIS)

    Dollani, K.; Kushe, R.

    1997-01-01

    In the present paper are described the status of regulatory aspects of low doses control as well as the existing procedures for their implementation in Albania. According to new Radiological Protection Act, approved by Parliament in 1995, the establishment of the infrastructures in radiation protection area is in course, accompanied by the installation and functioning of new equipment for low dose control. Based in many years experience it is concluded that personal doses of the workers added by practices in Albania are 1/10 of dose Emits. Some particular cases of overexposured workers were investigated. Last times the elements of the optimisation procedures (QA and QC) are outlined in the frame of improving regulatory aspects of low doses control. (author)

  13. Exposure to low doses of ionizing radiations

    International Nuclear Information System (INIS)

    Le Guen, B.

    2008-01-01

    The author discusses the knowledge about the effects of ionizing radiations on mankind. Some of them have been well documented (skin cancer and leukaemia for the pioneer scientists who worked on radiations, some other types of cancer for workers who handled luminescent paints, rock miners, nuclear explosion survivors, patients submitted to radiological treatments). He also evokes the issue of hereditary cancers, and discusses the issue of low dose irradiation where some surveys can now be performed on workers. He discusses the biological effects of these low doses. He outlines that many questions remain about these effects, notably the influence of dose level and of dose rate level on the biological reaction

  14. Bioavailability of diclofenac potassium at low doses

    Science.gov (United States)

    Hinz, Burkhard; Chevts, Julia; Renner, Bertold; Wuttke, Henrike; Rau, Thomas; Schmidt, Andreas; Szelenyi, Istvan; Brune, Kay; Werner, Ulrike

    2005-01-01

    Aim Diclofenac-K has been recently launched at low oral doses in different countries for over-the-counter use. However, given the considerable first-pass metabolism of diclofenac, the degree of absorption of diclofenac-K at low doses remained to be determined. The aim of this study was to determine the bioavailability of low-dose diclofenac-K. Methods A randomized, three-way, cross-over study was performed in 10 subjects. Each received diclofenac-K, 22.5 mg via short-term i.v. infusion and orally at single doses of 12.5 mg and 25 mg. Results Mean (± SD) times to maximal plasma concentration (tmax) of diclofenac were 0.48 ± 0.28 h (12.5 mg) and 0.93 ± 0.96 h (25 mg). The absolute bioavailability of diclofenac-K after oral administration did not differ significantly in the 12.5-mg and 25-mg dose group (63.1 ± 12.6% vs. 65.1 ± 19.4%, respectively). The 90% confidence intervals for the AUC∞ and AUCt ratios for the two oral regimes were 82.6, 103.4% (point estimate 92.4%) and 86.2, 112.9% (point estimate 98.6%), respectively. These values were within the acceptance criteria for bioequivalence (80–125%). Conclusions Our data indicate that diclofenac-K is rapidly and well absorbed at low dose, and are consistent with a rapid onset of action of the drug. Abbreviations AUC, area under plasma concentraton-time curve; Cmax, peak plasma concentration; CI, confidence interval; COX, cyclooxygenase; D, dose; F, absolute bioavailability; tmax, time to reach Cmax. PMID:15606444

  15. Preoperative dexamethasone reduces acute but not sustained pain after lumbar disk surgery

    DEFF Research Database (Denmark)

    Nielsen, Rikke V; Siegel, Hanna; Fomsgaard, Jonna S

    2015-01-01

    on acute and sustained pain after lumbar disk surgery. In this blinded study, 160 patients undergoing lumbar disk surgery were randomly assigned to 16 mg IV dexamethasone or placebo. All patients received perioperative paracetamol and ibuprofen, and postoperative IV patient-controlled analgesia...... months postoperatively. Acute pain during mobilization (weighted average area under the curve, 2-24 hours) was significantly reduced in the dexamethasone group: 33 (22) mm vs placebo 43 (18) mm, (95% confidence interval [CI] 3-16) P = 0.005. Vomiting 0 to 24 hours postoperatively was reduced....../paralysis of the legs in the dexamethasone and placebo groups, respectively, 3 months postoperatively (P = 0.20). In conclusion, preoperative dexamethasone significantly reduced pain during mobilization and vomiting, after lumbar disk surgery. No significant effects were observed 3 months postoperatively....

  16. Carcinogenesis in mice after low doses and dose rates

    International Nuclear Information System (INIS)

    Ullrich, R.L.

    1979-01-01

    The results from the experimental systems reported here indicate that the dose-response curves for tumor induction in various tissues cannot be described by a single model. Furthermore, although the understanding of the mechanisms involved in different systems is incomplete, it is clear that very different mechanisms for induction are involved. For some tumors the mechanism of carcinogenesis may be mainly a result of direct effects on the target cell, perhaps involving one or more mutations. While induction may occur, in many instances, through such direct effects, the eventual expression of the tumor can be influenced by a variety of host factors including endocrine status, competence of the immune system, and kinetics of target and interacting cell populations. In other tumors, indirect effects may play a major role in the initiation or expression of tumors. Some of the hormone-modulated tumors would fall into this class. Despite the complexities of the experimental systems and the lack of understanding of the types of mechanisms involved, in nearly every example the tumorigenic effectiveness per rad of low-LET radiation tends to decrease with decreasing dose rate. For some tumor types the differences may be small or may appear only with very low dose rates, while for others the dose-rate effects may be large

  17. Some remarks on the significance of low doses

    International Nuclear Information System (INIS)

    Cigna, A.A.

    1989-12-01

    The criteria of the present system of individual dose limitation are considered as well as the evolution of the limiting values. The assumption of the linearity of the dose-effect relationship without any threshold is probably the best approach to adopt for recommendations in radiation protection and for accounting the doses acquired by exposure to ionizing radiation. On the other hand the present evaluation of the natural background could imply a different dose-effect relationship in the low doses region and perhaps the existence of a threshold. Therefore the extrapolations which are usually made after exposures of different groups of people to low doses cannot be considered as scientifically sound. (author)

  18. Mutation induction in cultured human cells after low-dose and low-dose-rate γ-ray irradiation. Detection by LOH analysis

    International Nuclear Information System (INIS)

    Umebayashi, Yukihiro; Iwaki, Masaya; Yatagai, Fumio; Honma, Masamitsu; Suzuki, Masao; Suzuki, Hiromi; Shimazu, Toru; Ishioka, Noriaki

    2007-01-01

    To study the genetic effects of low-doses and low-dose-rate ionizing radiation (IR), human lymphoblastoid TK6 cells were exposed to 30 mGy of γ-rays at a dose-rate of 1.2 mGy/hr. The frequency of early mutations (EMs) in the thymidine kinase (TK) gene locus was determined to be 1.7 x 10 -6 , or 1.9-fold higher than the level seen in unirradiated controls. These mutations were analyzed with a loss of heterozygosity (LOH) detection system, a methodology which has been shown to be sensitive to the effects of radiation. Among the 15 EMs observed after IR exposure, 8 were small interstitial-deletion events restricted to the TK gene locus. However, this specific type of event was not found in unirradiated controls. Although these results were observed under the limited conditions, they strongly suggest that the LOH detection system can be used for estimating the genetic effects of a low-dose IR exposure delivered at a low-dose-rate. (author)

  19. Progress in structure recovery from low dose exposures: Mixed molecular adsorption, exploitation of symmetry and reconstruction from the minimum signal level

    Energy Technology Data Exchange (ETDEWEB)

    Kramberger, C., E-mail: Christian.Kramberger-Kaplan@univie.ac.at; Meyer, J.C., E-mail: Jannik.Meyer@univie.ac.at

    2016-11-15

    We investigate the recovery of structures from large-area, low dose exposures that distribute the dose over many identical copies of an object. The reconstruction is done via a maximum likelihood approach that does neither require to identify nor align the individual particles. We also simulate small molecular adsorbates on graphene and demonstrate the retrieval of images with atomic resolution from large area and extremely low dose raw data. Doses as low as 5 e{sup −}/Å{sup 2} are sufficient if all symmetries (translations, rotations and mirrors) of the supporting membrane are exploited to retrieve the structure of individual adsorbed molecules. We compare different optimization schemes, consider mixed molecules and adsorption sites, and requirements on the amount of data. We further demonstrate that the maximum likelihood approach is only count limited by requiring at least three independent counts per entity. Finally, we demonstrate that the approach works with real experimental data and in the presence of aberrations.

  20. Deep learning for low-dose CT

    Science.gov (United States)

    Chen, Hu; Zhang, Yi; Zhou, Jiliu; Wang, Ge

    2017-09-01

    Given the potential risk of X-ray radiation to the patient, low-dose CT has attracted a considerable interest in the medical imaging field. Currently, the main stream low-dose CT methods include vendor-specific sinogram domain filtration and iterative reconstruction algorithms, but they need to access raw data whose formats are not transparent to most users. Due to the difficulty of modeling the statistical characteristics in the image domain, the existing methods for directly processing reconstructed images cannot eliminate image noise very well while keeping structural details. Inspired by the idea of deep learning, here we combine the autoencoder, deconvolution network, and shortcut connections into the residual encoder-decoder convolutional neural network (RED-CNN) for low-dose CT imaging. After patch-based training, the proposed RED-CNN achieves a competitive performance relative to the-state-of-art methods. Especially, our method has been favorably evaluated in terms of noise suppression and structural preservation.

  1. Rituximab and Dexamethasone vs Dexamethasone Monotherapy in Newly Diagnosed Patients with Primary Immune Thrombocytopenia

    DEFF Research Database (Denmark)

    Gudbrandsdottir, Sif; Birgens, Henrik Sverre; Frederiksen, Henrik

    2013-01-01

    In this study, we report the results from the largest cohort to date of newly diagnosed adult immune thrombocytopenia patients randomized to treatment with dexamethasone alone or in combination with rituximab. Eligible were patients with platelet counts ≤25×10(9)/L or ≤50×10(9)/L with bleeding sy...

  2. Low dose irradiation reduces cancer mortality rates

    International Nuclear Information System (INIS)

    Luckey, T.D.

    2000-01-01

    Low doses of ionizing radiation stimulate development, growth, memory, sensual acuity, fecundity, and immunity (Luckey, T.D., ''Radiation Hormesis'', CRC Press, 1991). Increased immune competence reduces cancer mortality rates and provides increased average lifespan in animals. Decreased cancer mortality rates in atom bomb victims who received low dose irradiation makes it desirable to examine populations exposed to low dose irradiation. Studies with over 300,000 workers and 7 million person-years provide a valid comparison of radiation exposed and control unclear workers (Luckey, T.D., Nurture with Ionizing Radiation, Nutrition and Cancer, 34:1-11, 1999). Careful selection of controls eliminated any ''healthy worker effect''. The person-year corrected average indicated the cancer mortality rate of exposed workers was only 51% that of control workers. Lung cancer mortality rates showed a highly significant negative correlation with radon concentrations in 272,000 U.S. homes (Cohen, B.L., Health Physics 68:157-174, 1995). In contrast, radon concentrations showed no effect on lung cancer rates in miners from different countries (Lubin, J.H. Am. J. Epidemiology 140:323-332, 1994). This provides evidence that excessive lung cancer in miners is caused by particulates (the major factor) or toxic gases. The relative risk for cancer mortality was 3.7% in 10,000 Taiwanese exposed to low level of radiation from 60 Co in their steel supported homes (Luan, Y.C. et al., Am. Nuclear Soc. Trans. Boston, 1999). This remarkable finding needs further study. A major mechanism for reduced cancer mortality rates is increased immune competence; this includes both cell and humoral components. Low dose irradiation increases circulating lymphocytes. Macrophage and ''natural killer'' cells can destroy altered (cancer) cells before the mass becomes too large. Low dose irradiation also kills suppressor T-cells; this allows helper T-cells to activate killer cells and antibody producing cells

  3. Assessment of low absorbed dose with a MOSFET detector

    International Nuclear Information System (INIS)

    Butson, M.J.; Cancer Services, Wollongong, NSW; Cheung, T.; Yu, P.K.N.

    2004-01-01

    Full text: The ability of a MOSFET dosimetry system to measure low therapeutic doses has been evaluated for accuracy for high energy x-ray radiotherapy applications. The MOSFET system in high sensitivity mode produces a dose measurement reproducibility of within 10%, 4% and 2.5% for 2 cGy, 5 cGy and 10cGy dose assessment respectively. This is compared to 7%, 4% and 2% for an Attix parallel plate ionisation chamber and 20%, 7% and 3.5% for a Wellhofer IC4 small volume ionisation chamber. Results for our dose standard thimble ionisation chamber and low noise farmer dosemeter were 2%, 0.5% and 0.25% respectively for these measurements. The quoted accuracy of the MOSFET dosimetry system is partially due to the slight non linear dose response (reduced response) with age of the detector but mainly due to the intrinsic variations in measured voltage differential per applied dose. Results have shown that the MOSFET dosimetry system provides an adequate measure of dose at low dose levels and is comparable in accuracy to the Attix parallel plate ionisation chambers for relative dose assessment at levels of 2cGy to 10cGy. The use of the MOSFET dosimeter at low doses can extend the life expectancy of the device and may provide useful information for areas where low dose assessment is required. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  4. Long-term reversibility of renal dysfunction associated to light chain deposition disease with bortezomib and dexamethasone and high dose therapy and autologous stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Tomás J. González-López

    2011-11-01

    Full Text Available A 63-year-old woman presented with progressive renal insufficiency, until a glomerular filtration rate (GFR of 12 mL/min. A renal biopsy demonstrated glomerular deposition of immunoglobulin k light chain. The presence of a small population of monoclonal plasmacytes producing an only light k monoclonal component was demonstrated and Bortezomib and Dexamethasone (BD was provided as initial therapy. After seven courses of therapy, renal function improved without dialysis requirements up to a GFR 31 mL/min. Under hematological complete response (HCR the patient underwent high dose of melphalan (HDM and autologous peripheral blood stem cell transplant. Fifty-four months later the patient remains in HCR and the GFR has progressively improved up to 48 mL/min. This report describes a notably renal function improvement in a patient with Light Chain Deposition Disease after therapy with BD followed by HDM, which can support this treatment as a future option for these patients.

  5. Low dose epidemiology

    International Nuclear Information System (INIS)

    Tirmarche, M.; Hubert, P.

    1992-01-01

    Actually, epidemiological studies have to establish if the assessment of cancer risk can be verified at low chronic radiation doses. The population surveillance must be very long, the side effects and cancers of such radiation appearing much later. In France, this epidemiological study on nuclear workers have been decided recently. Before describing the experiment and french projects in epidemiology of nuclear workers, the authors present the main english and american studies

  6. Dexamethasone nanowafer as an effective therapy for dry eye disease.

    Science.gov (United States)

    Coursey, Terry G; Henriksson, Johanna Tukler; Marcano, Daniela C; Shin, Crystal S; Isenhart, Lucas C; Ahmed, Faheem; De Paiva, Cintia S; Pflugfelder, Stephen C; Acharya, Ghanashyam

    2015-09-10

    Dry eye disease is a major public health problem that affects millions of people worldwide. It is presently treated with artificial tear and anti-inflammatory eye drops that are generally administered several times a day and may have limited therapeutic efficacy. To improve convenience and efficacy, a dexamethasone (Dex) loaded nanowafer (Dex-NW) has been developed that can release the drug on the ocular surface for a longer duration of time than drops, during which it slowly dissolves. The Dex-NW was fabricated using carboxymethyl cellulose polymer and contains arrays of 500 nm square drug reservoirs filled with Dex. The in vivo efficacy of the Dex-NW was evaluated using an experimental mouse dry eye model. These studies demonstrated that once a day Dex-NW treatment on alternate days during a five-day treatment period was able to restore a healthy ocular surface and corneal barrier function with comparable efficacy to twice a day topically applied dexamethasone eye drop treatment. The Dex-NW was also very effective in down regulating expression of inflammatory cytokines (TNF-α, and IFN-γ), chemokines (CXCL-10 and CCL-5), and MMP-3, that are stimulated by dry eye. Despite less frequent dosing, the Dex-NW has comparable therapeutic efficacy to topically applied Dex eye drops in experimental mouse dry eye model, and these results provide a strong rationale for translation to human clinical trials for dry eye. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Dexamethasone Protects Against Tourniquet-Induced Acute Ischemia-Reperfusion Injury in Mouse Hindlimb

    Directory of Open Access Journals (Sweden)

    Ryan M. Corrick

    2018-03-01

    Full Text Available Extremity injuries with hemorrhage have been a significant cause of death in civilian medicine and on the battlefield. The use of a tourniquet as an intervention is necessary for treatment to an injured limb; however, the tourniquet and subsequent release results in serious acute ischemia-reperfusion (IR injury in the skeletal muscle and neuromuscular junction (NMJ. Much evidence demonstrates that inflammation is an important factor to cause acute IR injury. To find effective therapeutic interventions for tourniquet-induced acute IR injuries, our current study investigated effect of dexamethasone, an anti-inflammatory drug, on tourniquet-induced acute IR injury in mouse hindlimb. In C57/BL6 mice, a tourniquet was placed on unilateral hindlimb (left hindlimb at the hip joint for 3 h, and then released for 24 h to induce IR. Three hours of tourniquet and 24 h of release (24-h IR caused gastrocnemius muscle injuries including rupture of the muscle sarcolemma and necrosis (42.8 ± 2.3% for infarct size of the gastrocnemius muscle. In the NMJ, motor nerve terminals disappeared, and endplate potentials were undetectable in 24-h IR mice. There was no gastrocnemius muscle contraction in 24-h IR mice. Western blot data showed that inflammatory cytokines (TNFα and IL-1β were increased in the gastrocnemius muscle after 24-h IR. Treatment with dexamethasone at the beginning of reperfusion (1 mg/kg, i.p. significantly inhibited expression of TNFα and IL-1β, reduced rupture of the muscle sarcolemma and infarct size (24.8 ± 2.0%, and improved direct muscle stimulation-induced gastrocnemius muscle contraction in 24-h IR mice. However, this anti-inflammatory drug did not improve NMJ morphology and function, and sciatic nerve-stimulated skeletal muscle contraction in 24-h IR mice. The data suggest that one-time treatment with dexamethasone at the beginning of reperfusion only reduced structural and functional impairments of the skeletal muscle but not the

  8. Higher Dose of Dexamethasone Does Not Further Reduce Facial Swelling After Orthognathic Surgery: A Randomized Controlled Trial Using 3-Dimensional Photogrammetry.

    Science.gov (United States)

    Lin, Hsiu Hsia; Kim, Sun-Goo; Kim, Hye-Young; Niu, Lien-Shin; Lo, Lun-Jou

    2017-03-01

    The objective of this prospective, double-blind, randomized clinical trial was to compare the effect of 2 dexamethasone dosages on reducing facial swelling after orthognathic surgery through 3-dimensional (3D) photogrammetry. Patients were classified into group 1 (control group) and group 2 (study group), depending on the administered dexamethasone dosage (5 and 15 mg, respectively). Three-dimensional images were recorded at 5 time points: preoperative (T0) and postoperative at 48 ± 6 hours (T1), 1 week (T2), 1 month (T3), and 6 months (T4). A preliminary study was performed on 5 patients, in whom 3D images were captured at 24, 36, 48, and 60 hours postoperatively to record serial changes in facial swelling. Facial swelling at T1, T2, and T3 and the reduction in swelling at T2 and T3 compared with that at the baseline (T4) were calculated. Possible complications, namely, adrenal suppression, wound dehiscence, wound infection, and postoperative nausea and vomiting were evaluated. In total, 68 patients were enrolled, of whom 25 patients in group 1 and 31 patients in group 2 were eligible for final evaluation. No significant differences were found between the 2 groups at any period. On average, the swelling subsided by 86% at 1 month after the orthognathic surgery. Facial swelling peaked approximately 48 hours after the surgery. The incidence of nausea and vomiting did not differ significantly between the groups. The effect of 5 and 15 mg of dexamethasone on facial swelling reduction as well as on nausea and vomiting after orthognathic surgery was not significantly different.

  9. Risks to health from radiation at low dose rates

    International Nuclear Information System (INIS)

    Gentner, N.E.; Osborne, R.V.

    1997-01-01

    Our focus is on whether, using a balance-of-evidence approach, it is possible to say that at a low enough dose, or at a sufficiently low dose rate, radiation risk reduces to zero in a population. We conclude that insufficient evidence exists at present to support such a conclusion. In part this reflects statistical limitations at low doses, and in part (although mechanisms unquestionably exist to protect us against much of the damage induced by ionizing radiation) the biological heterogeneity of human populations, which means these mechanisms do not act in all members of the population at all times. If it is going to be possible to demonstrate that low doses are less dangerous than we presently assume, the evidence, paradoxically, will likely come from studies of higher dose and dose rate scenarios than are encountered occupationally. (author)

  10. Super-low dose endotoxin pre-conditioning exacerbates sepsis mortality.

    Science.gov (United States)

    Chen, Keqiang; Geng, Shuo; Yuan, Ruoxi; Diao, Na; Upchurch, Zachary; Li, Liwu

    2015-04-01

    Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditionings with super-low or low dose endotoxin lipopolysaccharide (LPS) cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP). This is in opposite to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET) in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a novel mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

  11. Super-low Dose Endotoxin Pre-conditioning Exacerbates Sepsis Mortality

    Directory of Open Access Journals (Sweden)

    Keqiang Chen

    2015-04-01

    Full Text Available Sepsis mortality varies dramatically in individuals of variable immune conditions, with poorly defined mechanisms. This phenomenon complements the hypothesis that innate immunity may adopt rudimentary memory, as demonstrated in vitro with endotoxin priming and tolerance in cultured monocytes. However, previous in vivo studies only examined the protective effect of endotoxin tolerance in the context of sepsis. In sharp contrast, we report herein that pre-conditioning with super-low or low dose endotoxin lipopolysaccharide (LPS cause strikingly opposite survival outcomes. Mice pre-conditioned with super-low dose LPS experienced severe tissue damage, inflammation, increased bacterial load in circulation, and elevated mortality when they were subjected to cecal-ligation and puncture (CLP. This is in contrast to the well-reported protective phenomenon with CLP mice pre-conditioned with low dose LPS. Mechanistically, we demonstrated that super-low and low dose LPS differentially modulate the formation of neutrophil extracellular trap (NET in neutrophils. Instead of increased ERK activation and NET formation in neutrophils pre-conditioned with low dose LPS, we observed significantly reduced ERK activation and compromised NET generation in neutrophils pre-conditioned with super-low dose LPS. Collectively, our findings reveal a mechanism potentially responsible for the dynamic programming of innate immunity in vivo as it relates to sepsis risks.

  12. Low doses of dextromethorphan attenuate morphine-induced rewarding via the sigma-1 receptor at ventral tegmental area in rats.

    Science.gov (United States)

    Chen, Shiou-Lan; Hsu, Kuei-Ying; Huang, Eagle Yi-Kung; Lu, Ru-Band; Tao, Pao-Luh

    2011-09-01

    Chronic use of morphine causes rewarding and behavioral sensitization, which may lead to the development of psychological craving. In our previous study, we found that a widely used antitussive dextromethorphan (known as a low affinity NMDA receptor antagonist), at doses of 10-20 mg/kg (i.p.), effectively decreased morphine rewarding in rats. In this study, we further investigated the effects and mechanisms of low doses of DM (μg/kg range) on morphine rewarding and behavioral sensitization. A conditioned place preference test was used to determine the rewarding and a locomotor activity test was used to determine the behavioral sensitization induced by the drug(s) in rats. When a low dose of DM (3 or 10 μg/kg, i.p.) was co-administered with morphine (5 mg/kg, s.c.), the rewarding effect, but not behavioral sensitization, induced by morphine was inhibited. The inhibiting effect of DM could be blocked by systemically administering a sigma-1 receptor antagonist, BD1047 (3 mg/kg, i.p.). When BD1047 (5 nmole/site) was locally given at the VTA, it also blocked the effects of a low dose of DM in inhibiting morphine rewarding. Our findings suggest that the activation of the sigma-1 receptor at the VTA may be involved in the mechanism of low doses of DM in inhibiting the morphine rewarding effect and the possibility of using extremely low doses of DM in treatment of opioid addiction in clinics. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. Ageing effects of polymers at very low dose-rates

    International Nuclear Information System (INIS)

    Chenion, J.; Armand, X.; Berthet, J.; Carlin, F.; Gaussens, G.; Le Meur, M.

    1987-10-01

    The equipment irradiation dose-rate into the containment is variable from 10 -6 to 10 -4 gray per second for the most exposed materials. During qualification, safety equipments are submitted in France to dose-rates around 0.28 gray per second. This study purpose is to now if a so large irradiation dose-rate increase is reasonable. Three elastomeric materials used in electrical cables, o'rings seals and connectors, are exposed to a very large dose-rates scale between 2.1.10 -4 and 1.4 gray per second, to 49 KGy dose. This work was carried out during 3.5 years. Oxygen consumption measurement of the air in contact with polymer materials, as mechanical properties measurement show that: - at very low dose-rate, oxygen consumption is maximum at the same time (1.4 year) for the three elastomeric samples. Also, mechanical properties simultaneously change with oxygen consumption. At very low dose-rate, for the low irradiation doses, oxygen consumption is at least 10 times more important that it is showed when irradiation is carried out with usual material qualification dose-rate. At very low dose-rate, oxygen consumption decreases when absorbed irradiation dose by samples increases. The polymer samples irradiation dose is not still sufficient (49 KGy) to certainly determine, for the three chosen polymer materials, the reasonable irradiation acceleration boundary during nuclear qualification tests [fr

  14. Addition of low-dose ketamine to midazolam and low-dose bupivacaine improves hemodynamics and postoperative analgesia during spinal anesthesia for cesarean section

    Directory of Open Access Journals (Sweden)

    Ahmed Sobhy Basuni

    2016-01-01

    Conclusion: Intrathecal low-dose ketamine combined with midazolam and low-dose bupivacaine stabilizes hemodynamics and prolongs postoperative analgesia without significant side-effects in parturients undergoing CS.

  15. Cancer and low dose responses in vivo: implications for radiation protection

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.

    2006-01-01

    Full text: Radiation protection practices assume that cancer risk is linearly proportional to total dose, without a threshold, both for people with normal cancer risk and for people who may be genetically cancer prone. Mice heterozygous for the Tp 53 gene are cancer prone, and their increased risk from high doses was not different from Tp 53 normal mice. However, in either Tp 53 normal or heterozygous mice, a single low dose of low LET radiation given at low dose rate protected against both spontaneous and radiation-induced cancer by increasing tumor latency. Increased tumor latency without a cancer frequency change implies that low doses in vivo primarily slow the process of genomic instability, consistent with the elevated capacity for correct DSB rejoining seen in low dose exposed cells. The in vivo animal data indicates that, for low doses and low dose rates in both normal and cancer prone adult mice, risk does not increase linearly with dose, and dose thresholds for increased risk exist. Below those dose thresholds (which are influenced by Tp 53 function) overall risk is reduced below that of unexposed control mice, indicating that Dose Rate Effectiveness Factors (DREF) may approach infinity, rather than the current assumption of 2. However, as dose decreases, different tissues appear to have different thresholds at which detriment turns to protection, indicating that individual tissue weighting factors (Wt) are also not constant, but vary from positive values to zero with decreasing dose. Measurements of Relative Biological Effect between high and low LET radiations are used to establish radiation weighting factors (Wr) used in radiation protection, and these are also assumed to be constant with dose. However, since the risk from an exposure to low LET radiation is not constant with dose, it would seem unlikely that radiation-weighting factors for high LET radiation are actually constant at low dose and dose rate

  16. Conditioned instrumental behaviour in the rat: Effects of prenatal irradiation with various low dose-rate doses

    International Nuclear Information System (INIS)

    Klug, H.

    1986-01-01

    4 groups of rats of the Wistar-strain were subjected to γ-irradiation on the 16th day of gestation. 5 rats received 0,6 Gy low dose rate irradiation, 5 animals received 0,9 Gy low dose and 6 high dose irradiation, 3 females were shamirradiated. The male offspring of these 3 irradiation groups and 1 control group were tested for locomotor coordination on parallel bars and in a water maze. The female offspring were used in an operant conditioning test. The locomotor test showed slight impairment of locomotor coordination in those animals irradiated with 0,9 Gy high dose rate. Swimming ability was significantly impaired by irradiation with 0,9 Gy high dose rate. Performance in the operant conditioning task was improved by irradiation with 0,9 Gy both low and high dose rate. The 0,9 Gy high dose rate group learned faster than all the other groups. For the dose of 0,9 Gy a significant dose rate effect could be observed. For the dose of 0,6 Gy a similar tendency was observed, differences between 0,6 Gy high and low dose rate and controls not being significant. (orig./MG) [de

  17. Dexamethasone prolongs local analgesia after subcutaneous infiltration of bupivacaine microcapsules in human volunteers

    DEFF Research Database (Denmark)

    Holte, Kathrine; Werner, Mads U; Lacouture, Peter G

    2002-01-01

    BACKGROUND: The addition of small amounts of dexamethasone to extended-release formulations of bupivacaine in microcapsules has been found to prolong local analgesia in experimental studies, but no clinical data are available. METHODS: In a double-blinded study, 12 healthy male volunteers were...... randomized to receive simultaneous subcutaneous injections of bupivacaine microcapsules with dexamethasone and bupivacaine microcapsules without dexamethasone in each calf. Local analgesia was assessed with a validated human pain model; main parameters evaluated were thermal, mechanical, and pain detection...... curve [AUC]) were considered best estimate of analgesia. Safety evaluations were performed daily for the first week and at 2 weeks, 6 weeks, and 6 months after injection. RESULTS: The addition of dexamethasone significantly prolonged local analgesia of bupivacaine microcapsules without influence...

  18. Does Dexamethasone Helps in Meningococcal Sepsis?

    Science.gov (United States)

    Tolaj, Ilir; Ramadani, Hamdi; Mehmeti, Murat; Gashi, Hatixhe; Kasumi, Arbana; Gashi, Visar; Jashari, Haki

    2017-06-01

    Prompt recognition and aggressive early treatment are the only effective measures against invasive meningococcal disease (IMD). Anti-inflammatory adjunctive treatment remains controversial and difficult to assess in patients with IMD. The purpose of this study was to evaluate the effect of dexamethasone (DXM) as adjunctive treatment in different clinical forms of IMD, and attempt to answer if DXM should be routinely used in the treatment of IMD. In this non-interventional clinical study (NIS), 39 patients with meningococcal septicaemia with or without of meningitis were included, and compared regarding the impact of dexamethasone (DXM), as an adjunctive treatment, on the outcome of IMD. SPSS statistics is used for statistical processing of data. Thirty (76.9%) patients with IMD had sepsis and meningitis, and 9 (23.1%) of them had sepsis alone. Dexamethasone was used in 24 (61.5%) cases, in both clinical groups. The overall mortality rate was 10.3%. Pneumonia was diagnosed in 6 patients (15.4%), arthritis in 3 of them (7.7%), and subdural effusion in one patient (2.6%). The data showed a significant statistical difference on the length of hospitalization, and WBC normalization in groups of patients treated with DXM. The use of DXM as adjunctive therapy in invasive meningococcal disease has a degree of proven benefits and no harmful effects. In fighting this very dangerous and complex infection, even a limited benefit is sufficient to recommend the use of DXM as adjunctive treatment in invasive meningococcal disease.

  19. Development of Plant Application Technique of Low Dose Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek (and others)

    2007-07-15

    The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources.

  20. Development of Plant Application Technique of Low Dose Radiation

    International Nuclear Information System (INIS)

    Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek

    2007-07-01

    The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources

  1. Global DNA methylation responses to low dose radiation exposure

    International Nuclear Information System (INIS)

    Newman, M.R.; Ormsby, R.J.; Blyth, B.J.; Sykes, P.J.; Bezak, E.

    2011-01-01

    Full text: High radiation doses cause breaks in the DNA which are considered the critical lesions in initiation of radiation-induced cancer. However, at very low radiation doses relevant for the general public, the induction of such breaks will be rare, and other changes to the DNA such as DNA methylation which affects gene expression may playa role in radiation responses. We are studying global DNA methylation after low dose radiation exposure to determine if low dose radiation has short- and/or long-term effects on chromatin structure. We developed a sensitive high resolution melt assay to measure the levels of DNA methylation across the mouse genome by analysing a stretch of DNA sequence within Long Interspersed Nuclear Elements-I (LINE I) that comprise a very large proportion of the mouse and human genomes. Our initial results suggest no significant short-term or longterm) changes in global NA methylation after low dose whole-body X-radiation of 10 J1Gyor 10 mGy, with a significant transient increase in NA methylation observed I day after a high dose of I Gy. If the low radiation doses tested are inducing changes in bal DNA methylation, these would appear to be smaller than the variation observed between the sexes and following the general stress of the sham-irradiation procedure itself. This research was funded by the Low Dose Radiation Research Program, Biological and Environmental Research, US DOE, Grant DE-FG02-05ER64104 and MN is the recipient of the FMCF/BHP Dose Radiation Research Scholarship.

  2. Extremely low frequencies. Health effects of extremely low frequency electromagnetic fields. Opinion of the Afsset. Collective expertise report

    International Nuclear Information System (INIS)

    Bounouh, Alexandre; Brugere, Henri; Clavel, Jacqueline; Febvre, Pascal; Lagroye, Isabelle; Vecchia, Paolo; Dore, Jean-Francois; Anfosso-Ledee, Fabienne; Berengier, Michel; Cesarini, Jean-Pierre; Cohen, Jean-Claude; Planton, Serge; Courant, Daniel; Tardif, Francois; Couturier, Frederic; Debouzy, Jean-Claude; El Khatib, Aicha; Flahaut, Emmanuel; Gaffet, Eric; Hours, Martine; Lambert, Jacques; Vallet, Michel; Job, Agnes; Labeyrie, Antoine; Laurier, Dominique; Le Bihan, Olivier; Lepoutre, Philippe; Marchal, Didier; Moch, Annie; Pirard, Philipe; Rumeau, Michel; De Seze, Rene; Attia, Dina; Merckel, Olivier; Fite, Johanna; Guichard, Alexandra; Saihi, Myriam; Guitton, Sophie; Saddoki, Sophia

    2010-03-01

    This report aims at proposing a synthesis of works of international expertise on the health effect of extremely low frequency electromagnetic fields, at performing a methodological analysis of the 'Expers' study (a study on the exposure of individuals), at performing a methodological analysis of a study performed by the Criirem in the western part of France, at assessing the contribution of different equipment and situations to the exposure of population to extremely-low-frequency electromagnetic fields, at making recommendations and proposals for a better assessment of the exposure level, and at proposing topics of investigation and research to improve knowledge on these issues. The report recalls the context, scope and modalities of the study, gives an overview of generalities on electromagnetic fields (nature, physical values, electromagnetic spectrum, artificial and natural electromagnetic field sources, exposure threshold values and regulatory context), addresses the assessment of exposure (notion of exposure, exposure assessment methods, analysis of available data, analysis of recent or current studies), gives an overview of biological and health effects of these electromagnetic fields (methodological aspects, interaction between fields and biological tissues, synthesis of the international expertise on health impacts). Recommendations are formulated

  3. Relationship between dose and risk, and assessment of carcinogenic risks associated with low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Tubiana, M.; Aurengo, A.

    2005-01-01

    This report raises doubts on the validity of using LNT (linear no-threshold) relationship for evaluating the carcinogenic risk of low doses (< 100 mSv) and even more for very low doses (< 10 mSv). The LNT concept can be a useful pragmatic tool for assessing rules in radioprotection for doses above 10 mSv; however since it is not based on biological concepts of our current knowledge, it should not be used without precaution for assessing by extrapolation the risks associated with low and even more so, with very low doses (< 10 mSv), especially for benefit-risk assessments imposed on radiologists by the European directive 97-43. The biological mechanisms are different for doses lower than a few dozen mSv and for higher doses. The eventual risks in the dose range of radiological examinations (0.1 to 5 mSv, up to 20 mSv for some examinations) must be estimated taking into account radiobiological and experimental data. An empirical relationship which has been just validated for doses higher than 200 mSv may lead to an overestimation of risks (associated with doses one hundred fold lower), and this overestimation could discourage patients from undergoing useful examinations and introduce a bias in radioprotection measures against very low doses (< 10 mSv). Decision makers confronted with problems of radioactive waste or risk of contamination, should re-examine the methodology used for the evaluation of risks associated with very low doses and with doses delivered at a very low dose rate. This report confirms the inappropriateness of the collective dose concept to evaluate population irradiation risks

  4. Comparison the Effect of Granisetron and Dexamethasone on Intravenous Propofol Pain.

    Science.gov (United States)

    Adinehmehr, Leili; Salimi, Sohrab; Sane, Shahryar; Sina, Venous; Najafizadeh, Rana

    2018-01-01

    The incidence of propofol injection pain during induction of general anesthesia varies from 28% to 90%. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexamethasone and granisetron for reducing the incidence and severity of propofol injection pain. A total of 227 female subjects received 5 mL of preservative-free saline, 1 mg granisetron (5 ml), or 0.15 mg/kg of dexamethasone (5 ml), intravenously, following exsanguination and occlusion of the veins of the arm. This was followed by a 0.5 mg/kg injection of propofol. Pain scores and intensity of pain recorded immediately following the injection of propofol. Hemodynamic parameters and O 2 sat were recorded 1, 3, 5, and 10 min after propofol injection. The incidence pain following the injection of propofol was significantly decreased with both granisetron and dexamethasone (50.7% and 49.4%). Mean pain score in granisetron group was 3.16 ± 1.23, dexamethasone was 2.73 ± 1.03, and in saline group was 4.82 ± 1.73 ( P = 0.001). Mean pain intensity in granisetron group was 1.16 ± 0.18, dexamethasone was 1.26 ± 0.14, and in saline group was 2.2 ± 0.99 ( P = 0.001). There were no differences in either mean arterial pressure or O 2 Sate at any time point after drugs injection among the groups. There was a significant difference in pulse rate in third minutes between three groups and in the group who received granisetron was lesser ( P = 0.04). Pretreatment with intravenous granisetron (1 mg) and dexamethasone (0.15 mg/kg) before injection of propofol is effective and safe in reducing the incidence and severity of pain due to propofol injection.

  5. Comparison the Effect of Granisetron and Dexamethasone on Intravenous Propofol Pain

    Directory of Open Access Journals (Sweden)

    Leili Adinehmehr

    2018-01-01

    Full Text Available Background: The incidence of propofol injection pain during induction of general anesthesia varies from 28% to 90%. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexamethasone and granisetron for reducing the incidence and severity of propofol injection pain. Materials and Methods: A total of 227 female subjects received 5 mL of preservative-free saline, 1 mg granisetron (5 ml, or 0.15 mg/kg of dexamethasone (5 ml, intravenously, following exsanguination and occlusion of the veins of the arm. This was followed by a 0.5 mg/kg injection of propofol. Pain scores and intensity of pain recorded immediately following the injection of propofol. Hemodynamic parameters and O2sat were recorded 1, 3, 5, and 10 min after propofol injection. Results: The incidence pain following the injection of propofol was significantly decreased with both granisetron and dexamethasone (50.7% and 49.4%. Mean pain score in granisetron group was 3.16 ± 1.23, dexamethasone was 2.73 ± 1.03, and in saline group was 4.82 ± 1.73 (P = 0.001. Mean pain intensity in granisetron group was 1.16 ± 0.18, dexamethasone was 1.26 ± 0.14, and in saline group was 2.2 ± 0.99 (P = 0.001. There were no differences in either mean arterial pressure or O2Sate at any time point after drugs injection among the groups. There was a significant difference in pulse rate in third minutes between three groups and in the group who received granisetron was lesser (P = 0.04. Conclusion: Pretreatment with intravenous granisetron (1 mg and dexamethasone (0.15 mg/kg before injection of propofol is effective and safe in reducing the incidence and severity of pain due to propofol injection.

  6. Comparison the Effect of Granisetron and Dexamethasone on Intravenous Propofol Pain

    Science.gov (United States)

    Adinehmehr, Leili; Salimi, Sohrab; Sane, Shahryar; Sina, Venous; Najafizadeh, Rana

    2018-01-01

    Background: The incidence of propofol injection pain during induction of general anesthesia varies from 28% to 90%. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexamethasone and granisetron for reducing the incidence and severity of propofol injection pain. Materials and Methods: A total of 227 female subjects received 5 mL of preservative-free saline, 1 mg granisetron (5 ml), or 0.15 mg/kg of dexamethasone (5 ml), intravenously, following exsanguination and occlusion of the veins of the arm. This was followed by a 0.5 mg/kg injection of propofol. Pain scores and intensity of pain recorded immediately following the injection of propofol. Hemodynamic parameters and O2 sat were recorded 1, 3, 5, and 10 min after propofol injection. Results: The incidence pain following the injection of propofol was significantly decreased with both granisetron and dexamethasone (50.7% and 49.4%). Mean pain score in granisetron group was 3.16 ± 1.23, dexamethasone was 2.73 ± 1.03, and in saline group was 4.82 ± 1.73 (P = 0.001). Mean pain intensity in granisetron group was 1.16 ± 0.18, dexamethasone was 1.26 ± 0.14, and in saline group was 2.2 ± 0.99 (P = 0.001). There were no differences in either mean arterial pressure or O2 Sate at any time point after drugs injection among the groups. There was a significant difference in pulse rate in third minutes between three groups and in the group who received granisetron was lesser (P = 0.04). Conclusion: Pretreatment with intravenous granisetron (1 mg) and dexamethasone (0.15 mg/kg) before injection of propofol is effective and safe in reducing the incidence and severity of pain due to propofol injection. PMID:29862223

  7. Low Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The overall research objective was to establish new levels of information about how people, groups, and communities respond to low dose radiation exposure. This is basic research into the social psychology of individual, group, and community responses to radiation exposures. The results of this research are directed to improving risk communication and public participation in management of environmental problems resulting from low dose radiation

  8. Extreme low-power mixed signal IC design

    CERN Document Server

    Tajalli, Armin

    2010-01-01

    This book describes a completely novel class of techniques for designing ultra-low-power integrated circuits (ICs). In many applications such as battery operated systems and battery-less (energy-scavenging) systems, power dissipation is a critical parameter. As a result, there is a growing demand for reducing the power (energy) consumption in ICs to extremely low levels, not achievable by using classical ""subthreshold CMOS"" techniques. This book introduces a new family of ""subthreshold circuits"" called ""source-coupled circuits"". This family of circuits can be used for implementing digita

  9. Double-blind comparative study of droperidol, granisetron and granisetron plus dexamethasone as prophylactic anti-emetic therapy in patients undergoing abdominal, gynaecological, breast or otolaryngological surgery

    NARCIS (Netherlands)

    Janknegt, R; Pinckaers, JWM; Rohof, MHC; Ausems, MEM; Arbouw, MEL; van der Velden, RW; Brouwers, JRBJ

    In this double-blind study the clinical efficacy of a single pre-operative intravenous dose of droperidol 1.25 mg (137 patients), granisetron 1 mg (130 patients) and granisetron 1 mg plus dexamethasone 5 mg (130 patients) was investigated for the prevention of postoperative nausea and vomiting after

  10. Solidification at the High and Low Rate Extreme

    Energy Technology Data Exchange (ETDEWEB)

    Meco, Halim [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  11. Quantitative analysis of biological responses to low dose-rate γ-radiation, including dose, irradiation time, and dose-rate

    International Nuclear Information System (INIS)

    Magae, J.; Furukawa, C.; Kawakami, Y.; Hoshi, Y.; Ogata, H.

    2003-01-01

    Full text: Because biological responses to radiation are complex processes dependent on irradiation time as well as total dose, it is necessary to include dose, dose-rate and irradiation time simultaneously to predict the risk of low dose-rate irradiation. In this study, we analyzed quantitative relationship among dose, irradiation time and dose-rate, using chromosomal breakage and proliferation inhibition of human cells. For evaluation of chromosome breakage we assessed micronuclei induced by radiation. U2OS cells, a human osteosarcoma cell line, were exposed to gamma-ray in irradiation room bearing 50,000 Ci 60 Co. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, cytoplasm and nucleus were stained with DAPI and propidium iodide, and the number of binuclear cells bearing micronuclei was determined by fluorescent microscopy. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [3H] thymidine was pulsed for 4 h before harvesting. Dose-rate in the irradiation room was measured with photoluminescence dosimeter. While irradiation time less than 24 h did not affect dose-response curves for both biological responses, they were remarkably attenuated as exposure time increased to more than 7 days. These biological responses were dependent on dose-rate rather than dose when cells were irradiated for 30 days. Moreover, percentage of micronucleus-forming cells cultured continuously for more than 60 days at the constant dose-rate, was gradually decreased in spite of the total dose accumulation. These results suggest that biological responses at low dose-rate, are remarkably affected by exposure time, that they are dependent on dose-rate rather than total dose in the case of long-term irradiation, and that cells are getting resistant to radiation after the continuous irradiation for 2 months. It is necessary to include effect of irradiation time and dose-rate sufficiently to evaluate risk

  12. Experimental study on effect of dexamethasone to the in-stent restenosis after vascular intervention

    International Nuclear Information System (INIS)

    Wang Jianbo; Yang Jianyong; Chen Wei; Zhuang Wenquan; Li Jiaping; Zhang Longjuan

    2007-01-01

    Objective: To evaluate the effect of dexamethasone to the cultured rat thoracic aortic smooth muscle cells (SMC) in vitro, and explore the role on it's prevention and cure for the in-stent restenosis after vascular intervention. Methods: The rat thoracic aortic SMC were harvested and cultured for six to ten passages. The cultured SMC were synchronized and then restimutated to enter the cell cycle, and treated with incremental concentrations of dexamethasone or without dexamethasone as control. The proliferative assay was performed with MTT method in the different time points after treatment. RT-PCR was performed to assay the level of proliferating cell nuclear antigen (PCNA) mRNA. Results: 1. Dexamethasone progressively inhibited rat aortic SMC proliferation in a concentration-dependent fashion. The A value was statistically significant for different concentrations (F=36.02, P -6 and 10 -5 mol/L (P=0.065) or between 10 -11 mol/L and control group (P 0.567). 2. RT-PCR suggested dexamethasone significantly decreased rat aortic SMC PCNA mRNA transcription in a concentration-dependent fashion. Statistical analysis indicated F=15.407 and P -9 or 10 -11 mol/L groups by post hoc analysis. Conclusions: Dexamethasone inhibits rat aortic SMC proliferation in a concentration- dependent fashion. The data suggest that effective action concentration is 10 -7 mol/L with persistent time up to 96 hours or more. Dexamethasone may play the inhibit role to SMC at lower concentration with prolonging action time. (authors)

  13. LOW DOSE RISK, DECISIONS, and RISK COMMUNICATION

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The objective of this project is to conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low-dose exposures. Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low-dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  14. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    International Nuclear Information System (INIS)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung

    2010-01-01

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in μSv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  15. Evaluation of the effective dose and image quality of low-dose multi-detector CT for orthodontic treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Gi Chung; Han, Won Jeong; Kim, Eun Kyung [Department of Oral and Maxillofacial Radiology, School of Dentistry, Dankook University, Cheonan (Korea, Republic of)

    2010-03-15

    This study was designed to compare the effective doses from low-dose and standard-dose multi-detector CT (MDCT) scanning protocols and evaluate the image quality and the spatial resolution of the low-dose MDCT protocols for clinical use. 6-channel MDCT scanner (Siemens Medical System, Forschheim, Germany), was used for this study. Protocol of the standard-dose MDCT for the orthodontic analysis was 130 kV, 35 mAs, 1.25 mm slice width, 0.8 pitch. Those of the low-dose MDCT for orthodontic analysis and orthodontic surgery were 110 kV, 30 mAs, 1.25 mm slice width, 0.85 pitch and 110 kV, 45 mAs, 2.5 mm slice width, 0.85 pitch. Thermoluminescent dosimeters (TLDs) were placed at 31 sites throughout the levels of adult female ART head and neck phantom. Effective doses were calculated according to ICRP 1990 and 2007 recommendations. A formalin-fixed cadaver and AAPM CT performance phantom were scanned for the evaluation of subjective image quality and spatial resolution. Effective doses in {mu}Sv (E2007) were 699.1, 429.4 and 603.1 for standard-dose CT of orthodontic treatment, low-dose CT of orthodontic analysis, and low-dose CT of orthodontic surgery, respectively. The image quality from the low-dose protocol were not worse than those from the standard-dose protocol. The spatial resolutions of both standard-dose and low-dose CT images were acceptable. From the above results, it can be concluded that the low-dose MDCT protocol is preferable in obtaining CT images for orthodontic analysis and orthodontic surgery.

  16. Low-dose radioiodine given six-monthly in Graves' disease

    International Nuclear Information System (INIS)

    Hoskin, P.J.; McCready, V.R.; Harmer, C.L.; Spathis, G.S.; Cosgrove, D.O.

    1985-01-01

    Experience using low-dose radioiodine given six-monthly instead of yearly in hyperthyroid patients with Graves' disease is reported. One hundred and thirty-five patients have been treated over a three-year period with 74 MBq (2 mCi) doses of 131 I. |Thirty-eight|percent| were controlled with a single dose. Those patients requiring more than one dose were treated with a further 74 MBq (2 mCi) 131 I at six-monthly intervals until euthyroid. Using this approach, 46% were euthyroid one year after starting treatment, and 75% were euthyroid at two years. The incidence of hypothyroidism following treatment was 2.2% at one year, with a yearly incidence thereafter of 4-6%. Six-monthly scheduling of low-dose radioiodine in Graves' disease can reduce the time taken to become euthyroid, compared with conventional yearly low-dose treatments. Further follow up is required to confirm the present low incidence of hypothyroidism following treatment. (author)

  17. Effect of dexamethasone on skeletal muscle Na+,K+ pump subunit specific expression and K+ homeostasis during exercise in humans

    DEFF Research Database (Denmark)

    Nordsborg, Nikolai; Ovesen, Jakob; Thomassen, Martin

    2008-01-01

    The effect of dexamethasone on Na(+),K(+) pump subunit expression and muscle exchange of K(+) during exercise in humans was investigated. Nine healthy male subjects completed a randomized double blind placebo controlled protocol, with ingestion of dexamethasone (Dex: 2 x 2 mg per day) or placebo...... (Pla) for 5 days. Na(+),K(+) pump catalytic alpha1 and alpha2 subunit expression was approximately 17% higher (P ...). The results indicate that an increased Na(+),K(+) pump expression per se is of importance for thigh K(+) reuptake at the onset of low and moderate intensity exercise, but less important during high intensity exercise....

  18. Effects of low dose mitomycin C on experimental tumor radiotherapy

    International Nuclear Information System (INIS)

    Yang Jianzheng; Liang Shuo; Qu Yaqin; Pu Chunji; Zhang Haiying; Wu Zhenfeng; Wang Xianli

    2001-01-01

    Objective: To evaluate the possibility of low dose mitomycin C(MMC) as an adjunct therapy for radiotherapy. Methods: Change in tumor size tumor-bearing mice was measured. Radioimmunoassay was used to determine immune function of mice. Results: Low dose Mac's pretreatment reduced tumor size more markedly than did radiotherapy only. The immune function in mice given with low dose MMC 12h before radiotherapy was obviously higher than that in mice subjected to radiotherapy only (P<0.05), and was close to that in the tumor-bearing mice before radiotherapy. Conclusion: Low dose MMC could improve the radiotherapy effect. Pretreatment with low dose MMC could obviously improve the immune suppression state in mice caused by radiotherapy. The mechanism of its improvement of radiotherapeutic effect by low dose of MMC might be due to its enhancement of immune function and induction of adaptive response in tumor-bearing mice

  19. Targeting Dexamethasone to Macrophages in a Porcine Endotoxemic Model

    DEFF Research Database (Denmark)

    Granfeldt, Asger; Hvas, Christine Lodberg; Graversen, Jonas Heilskov

    2013-01-01

    -8 minutes. CONCLUSION: Targeted delivery of dexamethasone to macrophages using a humanized CD163 antibody as carrier exhibits anti-inflammatory effects comparable with 50 times higher concentrations of free dexamethasone and does not inhibit endogenous cortisol production. This antibody-drug complex showing......OBJECTIVES: Macrophages are important cells in immunity and the main producers of pro-inflammatory cytokines. The main objective was to evaluate if specific delivery of glucocorticoid to the macrophage receptor CD163 is superior to systemic glucocorticoid therapy in dampening the cytokine response...

  20. A single dose of dexamethasone encapsulated in polyethylene glycol-coated polylactic acid nanoparticles attenuates cisplatin-induced hearing loss following round window membrane administration.

    Science.gov (United States)

    Sun, Changling; Wang, Xueling; Zheng, Zhaozhu; Chen, Dongye; Wang, Xiaoqin; Shi, Fuxin; Yu, Dehong; Wu, Hao

    2015-01-01

    This study aimed to investigate the sustained drug release properties and hearing protection effect of polyethylene glycol-coated polylactic acid (PEG-PLA) stealth nanoparticles loaded with dexamethasone (DEX). DEX was fabricated into PEG-PLA nanoparticles using an emulsion and evaporation technique, as previously reported. The DEX-loaded PEG-PLA nanoparticles (DEX-NPs) had a hydrodynamic diameter of 130±4.78 nm, and a zeta potential of -26.13±3.28 mV. The in vitro release of DEX from DEX-NPs lasted 24 days in phosphate buffered saline (pH 7.4), 5 days in artificial perilymph (pH 7.4), and 1 day in rat plasma. Coumarin 6-labeled NPs placed onto the round window membrane (RWM) of guinea pigs penetrated RWM quickly and accumulated to the organs of Corti, stria vascularis, and spiral ganglion cells after 1 hour of administration. The DEX-NPs locally applied onto the RWM of guinea pigs by a single-dose administration continuously released DEX in 48 hours, which was significantly longer than the free DEX that was cleared out within 12 hours after administration at the same dose. Further functional studies showed that locally administrated single-dose DEX-NPs effectively preserved outer hair cells in guinea pigs after cisplatin insult and thus significantly attenuated hearing loss at 4 kHz and 8 kHz frequencies when compared to the control of free DEX formulation. Histological analyses indicated that the administration of DEX-NPs did not induce local inflammatory responses. Therefore, prolonged delivery of DEX by PEG-PLA nanoparticles through local RWM diffusion (administration) significantly protected the hair cells and auditory function in guinea pigs from cisplatin toxicity, as determined at both histological and functional levels, suggesting the potential therapeutic benefits in clinical applications.

  1. Biological evidence of low ionizing radiation doses

    International Nuclear Information System (INIS)

    Mirsch, Johanna

    2017-01-01

    Throughout life, every person is constantly exposed to different types of ionising radiation, without even noticing the exposure. The mean radiation exposure for people living in Germany amounts to approximately 4 mSv per year and encompasses the exposure from natural and man-made sources. The risks associated with exposure to low doses of radiation are still the subject of intense and highly controversial discussions, emphasizing the social relevance of studies investigating the effects of low radiation doses. In this thesis, DNA double-strand breaks (DSBs) were analyzed within three projects covering different aspects. DSBs are among the most hazardous DNA lesions induced by ionizing radiation, because this type of damage can easily lead to the loss of genetic information. Consequently, the DSB presents a high risk for the genetic integrity of the cell. In the first project, extensive results uncovered the track structure of charged particles in a biological model tissue. This provided the first biological data that could be used for comparison with data that were measured or predicted using theoretical physical dosimetry methods and mathematical simulations. Charged particles contribute significantly to the natural radiation exposure and are used increasingly in cancer radiotherapy because they are more efficient in tumor cell killing than X- or γ-rays. The difference in the biological effects of high energy charged particles compared with X- or γ-rays is largely determined by the spatial distribution of their energy deposition and the track structure inducing a three-dimensional damage pattern in living cells. This damage pattern consists of cells directly hit by the particle receiving a high dose and neighboring cells not directly hit by primary particles but exposed to far-reaching secondary electrons (δ-electrons). These cells receive a much lower dose deposition in the order of a few mGy. The radial dose distribution of single particle tracks was

  2. The researches on the effects of low doses irradiation

    International Nuclear Information System (INIS)

    2009-02-01

    All research conducted as part of 'Risc-Rad' and those conducted by actors in international programs on low doses allow progress in understanding mechanisms of carcinogenesis associated with irradiation. The data do not question the use in radiation protection, risk estimation models based on a linear increase of the risk with the dose of radiation. Nevertheless, they show that the nature of biological responses induced by low doses of radiation has differences with the responses induced by high doses of radiation. They also show the diversity of effects/dose relationships as the mechanism observed and the importance of genetic predisposition in the individual sensitivity to low doses of radiation. It is therefore essential to continue to bring new data to better understand the complex biological effects and their impact on the establishment of radiation protection standards. In addition, the results have often been at the cellular level. The diversity of responses induced by radiations is also a function of cell types observed, the aging of cells and tissue organization. It is essential to strengthen researches at the tissue and body level, involving in vitro and in vivo approaches while testing the hypothesis in epidemiology with a global approach to systems biology. Over the past four years, the collaboration between partners of 'Risc-Rad' using experimental biology approaches and those using mathematical modeling techniques aimed at developing a new model describing the carcinogenesis induced by low radiation doses. On an other hand, The High level expert group on European low dose risk research (H.L.E.G.) develop programmes in the area of low dose irradiation (Germany, Finland, France, Italy and United Kingdom). It proposed a structure of trans national government called M.E.L.O.D.I. ( multidisciplinary european low dose initiative). Its objective is to structure and integrate European research by gathering around a common programme of multidisciplinary

  3. Mathematical model for evaluation of dose-rate effect on biological responses to low dose γ-radiation

    International Nuclear Information System (INIS)

    Ogata, H.; Kawakami, Y.; Magae, J.

    2003-01-01

    Full text: To evaluate quantitative dose-response relationship on the biological response to radiation, it is necessary to consider a model including cumulative dose, dose-rate and irradiation time. In this study, we measured micronucleus formation and [ 3 H] thymidine uptake in human cells as indices of biological response to gamma radiation, and analyzed mathematically and statistically the data for quantitative evaluation of radiation risk at low dose/low dose-rate. Effective dose (ED x ) was mathematically estimated by fitting a general function of logistic model to the dose-response relationship. Assuming that biological response depends on not only cumulative dose but also dose-rate and irradiation time, a multiple logistic function was applied to express the relationship of the three variables. Moreover, to estimate the effect of radiation at very low dose, we proposed a modified exponential model. From the results of fitting curves to the inhibition of [ 3 H] thymidine uptake and micronucleus formation, it was obvious that ED 50 in proportion of inhibition of [ 3 H] thymidine uptake increased with longer irradiation time. As for the micronuclei, ED 30 also increased with longer irradiation times. These results suggest that the biological response depends on not only total dose but also irradiation time. The estimated response surface using the three variables showed that the biological response declined sharply when the dose-rate was less than 0.01 Gy/h. These results suggest that the response does not depend on total cumulative dose at very low dose-rates. Further, to investigate the effect of dose-rate within a wider range, we analyzed the relationship between ED x and dose-rate. Fitted curves indicated that ED x increased sharply when dose-rate was less than 10 -2 Gy/h. The increase of ED x signifies the decline of the response or the risk and suggests that the risk approaches to 0 at infinitely low dose-rate

  4. A Paradigm Shift in Low Dose Radiation Biology

    Directory of Open Access Journals (Sweden)

    Z. Alatas

    2015-08-01

    Full Text Available When ionizing radiation traverses biological material, some energy depositions occur and ionize directly deoxyribonucleic acid (DNA molecules, the critical target. A classical paradigm in radiobiology is that the deposition of energy in the cell nucleus and the resulting damage to DNA are responsible for the detrimental biological effects of radiation. It is presumed that no radiation effect would be expected in cells that receive no direct radiation exposure through nucleus. The risks of exposure to low dose ionizing radiation are estimated by extrapolating from data obtained after exposure to high dose radiation. However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose radiation than they do to high dose radiation. Moreover, recent experimental evidences from many laboratories reveal the fact that radiation effects also occur in cells that were not exposed to radiation and in the progeny of irradiated cells at delayed times after radiation exposure where cells do not encounter direct DNA damage. Recently, the classical paradigm in radiobiology has been shifted from the nucleus, specifically the DNA, as the principal target for the biological effects of radiation to cells. The universality of target theory has been challenged by phenomena of radiation-induced genomic instability, bystander effect and adaptive response. The new radiation biology paradigm would cover both targeted and non-targeted effects of ionizing radiation. The mechanisms underlying these responses involve biochemical/molecular signals that respond to targeted and non-targeted events. These results brought in understanding that the biological response to low dose radiation at tissue or organism level is a complex process of integrated response of cellular targets as well as extra-cellular factors. Biological understanding of

  5. Effects of low dose radiation on tumor-bearing mice

    International Nuclear Information System (INIS)

    Feng Li; Hou Dianjun; Huang Shanying; Deng Daping; Wang Linchao; Cheng Yufeng

    2007-01-01

    Objective: To explore the effects of low-dose radiation on tumor-bearing mice and radiotherapy induced by low-dose radiation. Methods: Male Wistar mice were implanted with Walker-256 sarcoma cells in the right armpit. On day 4, the mice were given 75 mGy whole-body X-ray radiation. From the fifth day, tumor volume was measured, allowing for the creation of a graph depicting tumor growth. Lymphocytes activity in mice after whole-body X-ray radiation with LDR was determinned by FCM. Cytokines level were also determined by ELISA. Results: Compared with the radiotherapy group, tumor growth was significantly slower in the mice pre-exposed to low-dose radiation (P<0.05), after 15 days, the average tumor weight in the mice pre- exposed to low-dose radiation was also significantly lower (P<0.05). Lymphocytes activity and the expression of the CK in mice after whole-body y-ray radiation with LDR increased significantly. Conclusions: Low-dose radiation can markedly improve the immune function of the lymphocyte, inhibit the tumor growth, increase the resistant of the high-dose radiotherapy and enhance the effect of radiotherapy. (authors)

  6. The effect of dexamethasone on the uptake of p-boronophenylalanine in the rat brain and intracranial 9L gliosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Morris, G.M.; Micca, P.L.; Coderre, J.A. E-mail: coderre@mit.edu

    2004-11-01

    The steroid dexamethasone sodium phosphate (DEX) is routinely used to treat edema in brain tumor patients. The objective of the present study was to evaluate the effects of DEX on the uptake of boronophenylalanine (BPA) using the rat 9L gliosarcoma tumor model and surrounding brain tissue. Two steroid dosage protocols were used. The high-dose DEX protocol involved five 3 mg/kg intraperitoneal injections at 47, 35, 23, 11 and 1 h prior to the administration of the BPA for a total dose of 15 mg DEX/kg rat. The low-dose DEX administration protocol involved two doses of 1.5 mg/kg at 17 h and 1 h prior to BPA injection for a total dose of 3 mg DEX/kg rat. The control animals received no pretreatment, prior to the administration of BPA. Seventeen days after tumor implantation, rats were injected i.p. with 0.014 ml/g body weight BPA solution (1200 mg BPA/kg; {approx}59 mg {sup 10}B/kg). In all groups, rats were euthanized at 3 h after BPA injection. Administration of the steroid had an effect on tumor weight, which decreased to {approx}78% (p>0.05) of the control weight in the low-dose DEX group, and {approx}48% (p<0.001) of the control weight in the high-dose DEX group. At 3 h after the administration of BPA, the concentration of boron in tumor was comparable (p>0.1) in the control and high-dose DEX groups. The lowest mean value (73.8{+-}1.6 {mu}g/g) was obtained in the low-dose DEX group. This was significantly lower (p>0.02) than the tumor boron contents in the high-dose DEX and control groups, which were 81.1{+-}1.9 and 79.9{+-}1.7 {mu}g/g, respectively. Tumor:blood boron partition ratios for the control, low- and high-dose DEX groups were 2.3, 2.3 and 2.5, respectively. Boron concentrations were also measured in the normal brain and in the zone of brain adjacent to the tumor exhibiting edema. Although treatment with DEX had no appreciable effect on boron uptake in the normal brain of the rat, after the administration of BPA, it did impact on the boron levels in the

  7. Early corticosteroid treatment does not affect severity of unconjugated hyperbilirubinemia in extreme low birth weight preterm infants.

    Science.gov (United States)

    Hulzebos, Christian V; Bos, Arend F; Anttila, Eija; Hallman, Mikko; Verkade, Henkjan J

    2011-02-01

    To determine the relationship between early postnatal dexamethasone (DXM) treatment and the severity of hyperbilirubinemia in extreme low birth weight (ELBW) preterm infants. In 54 ELBW preterm infants, total serum bilirubin concentrations (TSB) and phototherapy (PT) data during the first 10 days were evaluated retrospectively. ELBW infants had participated in a randomized controlled trial of early DXM treatment which aimed to assess effects on chronic lung disease. Infants had been treated with DXM (0.25 mg/kg twice daily at postnatal day 1 and 2) or with placebo (normal saline). Analysis was performed on an intention to treat basis. Twenty-five Infants had been randomized into the DXM group; 29 into the placebo group. Mean (±SD) TSB [120 (±19) μmol/L vs. 123 (±28) μmol/L, DXM versus placebo, respectively] and maximum TSB [178 (±23) μmol/L vs. 176 (±48), DXM versus placebo, respectively] concentrations were similar. TSB concentrations peaked 30 h earlier in the DXM group (p ≤ 0.05). The need for PT as well as the duration of PT was similar in both groups. Early DXM treatment does not affect the severity of neonatal hyperbilirubinemia in ELBW preterm infants. Our results seem compatible with the concept that factors other than bilirubin conjugation capacity are important for the pathophysiology of neonatal jaundice in ELBW preterm infants. © 2010 The Author(s)/Acta Paediatrica © 2010 Foundation Acta Paediatrica.

  8. Personal dosimetry statistics and specifics of low dose evaluation

    International Nuclear Information System (INIS)

    Avila, R.E.; Gómez Salinas, R.A.; Oyarzún Cortés, C.H.

    2015-01-01

    The dose statistics of a personal dosimetry service, considering 35,000+ readings, display a sharp peak at low dose (below 0.5 mSv) with skewness to higher values. A measure of the dispersion is that approximately 65% of the doses fall below the average plus 2 standard deviations, an observation which may prove helpful to radiation protection agencies. Categorizing the doses by the concomitant use of a finger ring dosimeter, that skewness is larger in the whole body, and ring dosimeters. The use of Harshaw 5500 readers at high gain leads to frequent values of the glow curve that are judged to be spurious, i.e. values not belonging to the roughly normal noise over the curve. A statistical criterion is shown for identifying those anomalous values, and replacing them with the local behavior, as fit by a cubic polynomial. As a result, the doses above 0.05 mSv which are affected by more than 2% comprise over 10% of the data base. The low dose peak of the statistics, above, has focused our attention on the evaluation of LiF(Mg,Ti) dosimeters exposed at low dose, and read with Harshaw 5500 readers. The standard linear procedure, via an overall reader calibration factor, is observed to fail at low dose, in detailed calibrations from 0.02 mSv to 1 Sv. A significant improvement is achieved by a piecewise polynomials calibration curve. A cubic, at low dose is matched, at ∼10 mSv, in value and first derivative, to a linear dependence at higher doses. This improvement is particularly noticeable below 2 mSv, where over 60% of the evaluated dosimeters are found. (author)

  9. Exercise and sport performance with low doses of caffeine.

    Science.gov (United States)

    Spriet, Lawrence L

    2014-11-01

    Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5-13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (caffeine doses (1) do not alter the peripheral whole-body responses to exercise; (2) improve vigilance, alertness, and mood and cognitive processes during and after exercise; and (3) are associated with few, if any, side effects. Therefore, the ergogenic effect of low caffeine doses appears to result from alterations in the central nervous system. However, several aspects of consuming low doses of caffeine remain unresolved and suffer from a paucity of research, including the potential effects on high-intensity sprint and burst activities. The responses to low doses of caffeine are also variable and athletes need to determine whether the ingestion of ~200 mg of caffeine before and/or during training and competitions is ergogenic on an individual basis.

  10. Thermoluminescent dosimeters for low dose X-ray measurements

    International Nuclear Information System (INIS)

    Del Sol Fernández, S.; García-Salcedo, R.; Sánchez-Guzmán, D.; Ramírez-Rodríguez, G.; Gaona, E.; León-Alfaro, M.A. de; Rivera-Montalvo, T.

    2016-01-01

    The response of TLD-100, CaSO_4:Dy and LiF:Mg,Cu,P for a range of X-ray low dose was measured. For calibration, the TLDs were arranged at the center of the X-ray field. The dose output of the X-ray machine was determined using an ACCU-Gold. All dosimeters were exposed at the available air kerma values of 14.69 mGy within a field 10×10 cm"2 at 80 cm of SSD. Results of LiF:Mg,Cu,P X-ray irradiated showed 4.8 times higher sensitivity than TLD-100. Meanwhile, TL response of CaSO_4:Dy exposed at the same dose was 5.6 time higher than TLD-100. Experimental results show for low dose X-ray measurements a better linearity for LiF:Mg,Cu,P compared with that of TLD-100. CaSO_4:Dy showed a linearity from 0.1 to 60 mGy - Highlights: • Low dose X-ray doses for personal dosimetry were measured. • Radiation dose (µGy ) for environmental dosimetry were determined. • Scattering radiation dose were measured by TLDs. • Linearity of pair TLD system was successful in the range of microgray. • Pair TLDs composed by CaSO_4:Dy and by LiF:Mg,Cu,P. is suggested for clinical dosimetry.

  11. Melatonin attenuates prenatal dexamethasone-induced blood pressure increase in a rat model.

    Science.gov (United States)

    Tain, You-Lin; Chen, Chih-Cheng; Sheen, Jiunn-Ming; Yu, Hong-Ren; Tiao, Mao-Meng; Kuo, Ho-Chang; Huang, Li-Tung

    2014-04-01

    Although antenatal corticosteroid is recommended to accelerate fetal lung maturation, prenatal dexamethasone exposure results in hypertension in the adult offspring. Since melatonin is a potent antioxidant and has been known to regulate blood pressure, we examined the beneficial effects of melatonin therapy in preventing prenatal dexamethasone-induced programmed hypertension. Male offspring of Sprague-Dawley rats were assigned to four groups (n = 12/group): control, dexamethasone (DEX), control + melatonin, and DEX + melatonin. Pregnant rats received intraperitoneal dexamethasone (0.1 mg/kg) from gestational day 16 to 22. In the melatonin-treatment groups, rats received 0.01% melatonin in drinking water during their entire pregnancy and lactation. Blood pressure was measured by an indirect tail-cuff method. Gene expression and protein levels were analyzed by real-time quantitative polymerase chain reaction and Western blotting, respectively. At 16 weeks of age, the DEX group developed hypertension, which was partly reversed by maternal melatonin therapy. Reduced nephron numbers due to prenatal dexamethasone exposure were prevented by melatonin therapy. Renal superoxide and NO levels were similar in all groups. Prenatal dexamethasone exposure led to increased mRNA expression of renin and prorenin receptor and up-regulated histone deacetylase (HDAC)-1 expression in the kidneys of 4-month-old offspring. Maternal melatonin therapy augmented renal Mas protein levels in DEX + melatonin group, and increased renal mRNA expression of HDAC-1, HDAC-2, and HDAC-8 in control and DEX offspring. Melatonin attenuated prenatal DEX-induced hypertension by restoring nephron numbers, altering RAS components, and modulating HDACs. Copyright © 2014 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  12. Does Dexamethasone Helps in Meningococcal Sepsis?

    Science.gov (United States)

    Tolaj, Ilir; Ramadani, Hamdi; Mehmeti, Murat; Gashi, Hatixhe; Kasumi, Arbana; Gashi, Visar; Jashari, Haki

    2017-01-01

    Purpose: Prompt recognition and aggressive early treatment are the only effective measures against invasive meningococcal disease (IMD). Anti-inflammatory adjunctive treatment remains controversial and difficult to assess in patients with IMD. The purpose of this study was to evaluate the effect of dexamethasone (DXM) as adjunctive treatment in different clinical forms of IMD, and attempt to answer if DXM should be routinely used in the treatment of IMD. Methods: In this non-interventional clinical study (NIS), 39 patients with meningococcal septicaemia with or without of meningitis were included, and compared regarding the impact of dexamethasone (DXM), as an adjunctive treatment, on the outcome of IMD. SPSS statistics is used for statistical processing of data. Results: Thirty (76.9%) patients with IMD had sepsis and meningitis, and 9 (23.1%) of them had sepsis alone. Dexamethasone was used in 24 (61.5%) cases, in both clinical groups. The overall mortality rate was 10.3%. Pneumonia was diagnosed in 6 patients (15.4%), arthritis in 3 of them (7.7%), and subdural effusion in one patient (2.6%). The data showed a significant statistical difference on the length of hospitalization, and WBC normalization in groups of patients treated with DXM. Conclusion: The use of DXM as adjunctive therapy in invasive meningococcal disease has a degree of proven benefits and no harmful effects. In fighting this very dangerous and complex infection, even a limited benefit is sufficient to recommend the use of DXM as adjunctive treatment in invasive meningococcal disease. PMID:28974828

  13. Health effects of low doses at low dose rates: dose-response relationship modeling in a cohort of workers of the nuclear industry

    International Nuclear Information System (INIS)

    Metz-Flamant, Camille

    2011-01-01

    The aim of this thesis is to contribute to a better understanding of the health effects of chronic external low doses of ionising radiation. This work is based on the French cohort of CEA-AREVA NC nuclear workers. The mains stages of this thesis were (1) conducting a review of epidemiological studies on nuclear workers, (2) completing the database and performing a descriptive analysis of the cohort, (3) quantifying risk by different statistical methods and (4) modelling the exposure-time-risk relationship. The cohort includes monitored workers employed more than one year between 1950 and 1994 at CEA or AREVA NC companies. Individual annual external exposure, history of work, vital status and causes of death were reconstructed for each worker. Standardized mortality ratios using French national mortality rates as external reference were computed. Exposure-risk analysis was conducted in the cohort using the linear excess relative risk model, based on both Poisson regression and Cox model. Time dependent modifying factors were investigated by adding an interaction term in the model or by using exposure time windows. The cohort includes 36, 769 workers, followed-up until age 60 in average. During the 1968- 2004 period, 5, 443 deaths, 2, 213 cancers, 62 leukemia and 1, 314 cardiovascular diseases were recorded. Among the 57% exposed workers, the mean cumulative dose was 21.5 milli-sieverts (mSv). A strong Healthy Worker Effect is observed in the cohort. Significant elevated risks of pleura cancer and melanoma deaths were observed in the cohort but not associated with dose. No significant association was observed with solid cancers, lung cancer and cardiovascular diseases. A significant dose-response relationship was observed for leukemia excluding chronic lymphatic leukemia, mainly for doses received less than 15 years before and for yearly dose rates higher than 10 mSv. This PhD work contributes to the evaluation of risks associated to chronic external radiation

  14. Extreme low temperature tolerance in woody plants

    Directory of Open Access Journals (Sweden)

    George Richard Strimbeck

    2015-10-01

    Full Text Available Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40˚C and minimum temperatures below -60˚C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196˚C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature. Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at extreme low temperature: 1. Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to 30˚C, preventing phase changes that result in irreversible injury. 2. High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. 3. Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane-membrane interactions.

  15. Role of dexamethasone in brachial plexus block

    International Nuclear Information System (INIS)

    Dawood, M.

    2015-01-01

    To evaluate the effect of dexamethasone added to (lignocaine) on the onset and duration of axillary brachial plexus block. Study Design: Randomized controlled trial. Place and Duration of Study: Combined Military Hospital Rawalpindi, from September 2009 to March 2010. Patients and Methods: A total of 100 patients, who were scheduled for elective hand and forearm surgery under axillary brachial plexus block, were randomly allocated to group A in which patients received 40 ml 1.5% lidocaine with 2 ml of isotonic saline (0.9%) and group B in which patients received 40 ml 1.5% lidocaine with 2 ml of dexamethasone (8 mg). Nerve stimulator with insulated needle for multiple stimulations technique was used to locate the brachial plexus nerves. After the injection onset of action and duration of sensory blockade of brachial plexus were recorded at 5 minutes and 15 minutes interval. Results: Group A showed the onset of action of 21.64 ± 2.30 min and in group B it was 15.42 ± 1.44 min (p< 0.001). Duration of nerve block was 115.08 ± 10.92 min in group A and 265.42 ± 16.56 min in group B (p < 0.001). Conclusion: The addition of dexamethasone to 1.5% lignocaine solution in axillary brachial plexus block prolongs the duration of sensory blockade significantly. (author)

  16. Low-Dose and Standard-Dose Unenhanced Helical Computed Tomography for the Assessment of Acute Renal Colic: Prospective Comparative Study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Soo; Hwang, Im Kyung; Choi, Yo Won; Namkung, Sook; Kim, Heung Cheol; Hwang, Woo Cheol; Choi, Kuk Myung; Park, Ji Kang; Han, Tae Il; Kang, Weechang [Cheju National Univ. College of Medicine, Jeju (Korea, Republic of). Dept. of Diagnostic Radiology

    2005-11-01

    Purpose: To compare the efficacy of low-dose and standard-dose computed tomography (CT) for the diagnosis of ureteral stones. Material and Methods: Unenhanced helical CT was performed with both a standard dose (260 mAs, pitch 1.5) and a low dose (50 mAs, pitch 1.5) in 121 patients suspected of having acute renal colic. The two studies were prospectively and independently interpreted for the presence and location of ureteral stones, abnormalities unrelated to stone disease, identification of secondary signs, i.e. hydronephrosis and perinephric stranding, and tissue rim sign. The standard-dose CT images were interpreted by one reviewer and the low-dose CT images independently by two reviewers unaware of the standard-dose CT findings. The findings of the standard and low-dose CT scans were compared with the exact McNemar test. Interobserver agreements were assessed with kappa analysis. The effective radiation doses resulting from two different protocols were calculated by means of commercially available software to which the Monte-Carlo phantom model was given. Results: The sensitivity, specificity, and accuracy of standard-dose CT for detecting ureteral stones were 99%, 93%, and 98%, respectively, whereas for the two reviewers the sensitivity of low-dose CT was 93% and 95%, specificity 86%, and accuracy 92% and 94%. We found no significant differences between standard-dose and low-dose CT in the sensitivity and specificity for diagnosing ureter stones ( P >0.05 for both). However, the sensitivity of low-dose CT for detection of 19 stones less than or equal to 2 mm in diameter was 79% and 68%, respectively, for the two reviewers. Low-dose CT was comparable to standard-dose CT in visualizing hydronephrosis and the tissue rim sign. Perinephric stranding was far less clear on low-dose CT. Low-dose CT had the same diagnostic performance as standard-dose CT in diagnosing alternative diseases. Interobserver agreement between the two low-dose CT reviewers in the diagnosis of

  17. Generative Adversarial Networks for Noise Reduction in Low-Dose CT.

    Science.gov (United States)

    Wolterink, Jelmer M; Leiner, Tim; Viergever, Max A; Isgum, Ivana

    2017-12-01

    Noise is inherent to low-dose CT acquisition. We propose to train a convolutional neural network (CNN) jointly with an adversarial CNN to estimate routine-dose CT images from low-dose CT images and hence reduce noise. A generator CNN was trained to transform low-dose CT images into routine-dose CT images using voxelwise loss minimization. An adversarial discriminator CNN was simultaneously trained to distinguish the output of the generator from routine-dose CT images. The performance of this discriminator was used as an adversarial loss for the generator. Experiments were performed using CT images of an anthropomorphic phantom containing calcium inserts, as well as patient non-contrast-enhanced cardiac CT images. The phantom and patients were scanned at 20% and 100% routine clinical dose. Three training strategies were compared: the first used only voxelwise loss, the second combined voxelwise loss and adversarial loss, and the third used only adversarial loss. The results showed that training with only voxelwise loss resulted in the highest peak signal-to-noise ratio with respect to reference routine-dose images. However, CNNs trained with adversarial loss captured image statistics of routine-dose images better. Noise reduction improved quantification of low-density calcified inserts in phantom CT images and allowed coronary calcium scoring in low-dose patient CT images with high noise levels. Testing took less than 10 s per CT volume. CNN-based low-dose CT noise reduction in the image domain is feasible. Training with an adversarial network improves the CNNs ability to generate images with an appearance similar to that of reference routine-dose CT images.

  18. Cytogenetic Low-Dose Hyperradiosensitivity Is Observed in Human Peripheral Blood Lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Seth, Isheeta [Department of Biological Sciences, Wayne State University, Detroit, Michigan (United States); Joiner, Michael C. [Department of Radiation Oncology, Wayne State University, Detroit, Michigan (United States); Tucker, James D., E-mail: jtucker@biology.biosci.wayne.edu [Department of Biological Sciences, Wayne State University, Detroit, Michigan (United States)

    2015-01-01

    Purpose: The shape of the ionizing radiation response curve at very low doses has been the subject of considerable debate. Linear-no-threshold (LNT) models are widely used to estimate risks associated with low-dose exposures. However, the low-dose hyperradiosensitivity (HRS) phenomenon, in which cells are especially sensitive at low doses but then show increased radioresistance at higher doses, provides evidence of nonlinearity in the low-dose region. HRS is more prominent in the G2 phase of the cell cycle than in the G0/G1 or S phases. Here we provide the first cytogenetic mechanistic evidence of low-dose HRS in human peripheral blood lymphocytes using structural chromosomal aberrations. Methods and Materials: Human peripheral blood lymphocytes from 2 normal healthy female donors were acutely exposed to cobalt 60 γ rays in either G0 or G2 using closely spaced doses ranging from 0 to 1.5 Gy. Structural chromosomal aberrations were enumerated, and the slopes of the regression lines at low doses (0-0.4 Gy) were compared with doses of 0.5 Gy and above. Results: HRS was clearly evident in both donors for cells irradiated in G2. No HRS was observed in cells irradiated in G0. The radiation effect per unit dose was 2.5- to 3.5-fold higher for doses ≤0.4 Gy than for doses >0.5 Gy. Conclusions: These data provide the first cytogenetic evidence for the existence of HRS in human cells irradiated in G2 and suggest that LNT models may not always be optimal for making radiation risk assessments at low doses.

  19. Prevention of everolimus-related stomatitis in women with hormone receptor-positive, HER2-negative metastatic breast cancer using dexamethasone mouthwash (SWISH): a single-arm, phase 2 trial.

    Science.gov (United States)

    Rugo, Hope S; Seneviratne, Lasika; Beck, J Thaddeus; Glaspy, John A; Peguero, Julio A; Pluard, Timothy J; Dhillon, Navneet; Hwang, Leon Christopher; Nangia, Chaitali; Mayer, Ingrid A; Meiller, Timothy F; Chambers, Mark S; Sweetman, Robert W; Sabo, J Randy; Litton, Jennifer K

    2017-05-01

    Stomatitis is a class effect associated with the inhibition of mTOR and is associated with everolimus therapy for breast cancer. Topical steroids might reduce stomatitis incidence and severity, and the need for dose reductions and interruptions of everolimus. Anecdotal use of topical steroid oral prophylaxis has been reported in patients with breast cancer. We aimed to assess dexamethasone-based mouthwash for prevention of stomatitis in patients with breast cancer. This US-based, multicentre, single-arm, phase 2 prevention study enrolled women aged 18 years and older with postmenopausal status who had histologically or cytologically confirmed metastatic hormone receptor-positive, HER2-negative breast cancer. Beginning on day 1 of cycle 1, patients received everolimus 10 mg plus exemestane 25 mg daily, with 10 mL of alcohol-free dexamethasone 0·5 mg per 5 mL oral solution (swish for 2 min and spit, four times daily for 8 weeks). After 8 weeks, dexamethasone mouthwash could be continued for up to eight additional weeks at the discretion of the clinician and patient. The primary endpoint was incidence of grade 2 or worse stomatitis by 8 weeks assessed in the full analysis set (patients who received at least one dose of everolimus and exemestane and at least one confirmed dose of dexamethasone mouthwash) versus historical controls from the BOLERO-2 trial (everolimus and exemestane treatment in patients with hormone receptor-positive advanced breast cancer who were not given dexamethasone mouthwash for prevention of stomatitis). This trial is registered at ClinicalTrials.gov, number NCT02069093. Between May 28, 2014, and Oct 8, 2015, we enrolled 92 women; 85 were evaluable for efficacy. By 8 weeks, the incidence of grade 2 or worse stomatitis was two (2%) of 85 patients (95% CI 0·29-8·24), versus 159 (33%) of 482 patients (95% CI 28·8-37·4) for the duration of the BOLERO-2 study. Overall, 83 (90%) of 92 patients had at least one adverse event. The most frequently

  20. Evaluation of an every-other-day palonosetron schedule to control emesis in multiple-day high-dose chemotherapy.

    Science.gov (United States)

    Mirabile, Aurora; Celio, Luigi; Magni, Michele; Bonizzoni, Erminio; Gianni, Alessandro Massimo; Di Nicola, Massimo

    2014-12-01

    Efficacy of intermittent palonosetron dosing in patients undergoing multiple-day, high-dose chemotherapy (HDC) was investigated. Fifty-eight patients received palonosetron (0.25 mg intravenous [iv.]) every other day plus daily dexamethasone (8 mg iv. twice daily) dosing. The primary end point was complete control (CC; no emesis, no rescue anti-emetics, and no more than mild nausea) in the overall acute-period (until 24 h after chemotherapy completion). Acute-period CC occurred in 81% and 50% of patients receiving palonosetron and ondansetron (historical control cohort), respectively. Palonosetron (odds ratio [OR]: 4.37; p = 0.001) and a longer duration of HDC regimen (OR: 3.47; p = 0.011) independently predicted a better anti-emetic outcome. Palonosetron every other day plus daily dexamethasone is an effective anti-emetic coverage in patients undergoing HDC.

  1. SU-E-T-183: Feasibility of Extreme Dose Escalation for Glioblastoma Multiforme Using 4π Radiotherapy

    International Nuclear Information System (INIS)

    Nguyen, D; Rwigema, J; Yu, V; Kaprealian, T; Kupelian, P; Selch, M; Low, D; Sheng, K

    2014-01-01

    Purpose: GBM recurrence primarily occurs inside or near the high-dose radiation field of original tumor site requiring greater than 100 Gy to significantly improve local control. We utilize 4π non-coplanar radiotherapy to test the feasibility of planning target volume (PTV) margin expansions or extreme dose escalations without incurring additional radiation toxicities. Methods: 11 GBM patients treated with VMAT to a prescription dose of 59.4 Gy or 60 Gy were replanned with 4π. Original VMAT plans were created with 2 to 4 coplanar or non-coplanar arcs using 3 mm hi-res MLC. The 4π optimization, using 5 mm MLC, selected and inverse optimized 30 beams from a candidate pool of 1162 beams evenly distributed through 4π steradians. 4π plans were first compared to clinical plans using the same prescription dose. Two more studies were then performed to respectively escalate the GTV and PTV doses to 100 Gy, followed by a fourth plan expanding the PTV by 5 mm and maintaining the prescription dose. Results: The standard 4π plan significantly reduced (p<0.01) max and mean doses to critical structures by a range of 47.0–98.4% and 61.0–99.2%, respectively. The high dose PTV/high dose GTV/expanded PTV studies showed a reduction (p<0.05) or unchanged* (p>0.05) maximum dose of 72.1%/86.7%/77.1% (chiasm), 7.2%*/27.7%*/30.7% (brainstem), 39.8%*/84.2%/51.9%* (spinal cord), 69.0%/87.0%/66.9% (L eye), 76.2%/88.1%/84.1% (R eye), 95.0%/98.6%/97.5% (L lens), 93.9%/98.8%/97.6% (R lens), 74.3%/88.5%/72.4% (L optical nerve), 80.4%/91.3%/75.7% (R optical nerve), 64.8%/84.2%/44.9%* (L cochlea), and 85.2%/93.0%/78.0% (R cochlea), respectively. V30 and V36 for both brain and (brain - PTV) were reduced for all cases except the high dose PTV plan. PTV dose coverage increased for all 4π plans. Conclusion: Extreme dose escalation or further margin expansion is achievable using 4π, maintaining or reducing OAR doses. This study indicates that clinical trials employing 4π delivery using

  2. Permissive effect of dexamethasone on the increase of proenkephalin mRNA induced by depolarization of chromaffin cells

    International Nuclear Information System (INIS)

    Naranjo, J.R.; Mocchetti, I.; Schwartz, J.P.; Costa, E.

    1986-01-01

    In cultured bovine chromaffin cells, changes in the dynamic state of enkephalin stores elicited experimentally were studied by measuring cellular proenkephalin mRNA, as well as enkephalin precursors and authentic enkephalin content of cells and culture media. In parallel, tyrosine hydroxylase mRNA and catecholamine cell content were also determined. Low concentrations (0.5-100 pM) of dexamethasone increased the cell contents of proenkephalin mRNA and enkephalin-containing peptides. High concentrations of the hormone(1 μM) were required to increase the cell contents of tyrosine hydroxylase mRNA and catecholamines. Depolarization of the cells with 10 μM veratridine resulted in a depletion of enkephalin and catecholamine stores after 24 hr. The enkephalin, but not the catecholamine, content was restored by 48 hr. An increase in proenkephalin mRNA content might account for the recovery; this increase was curtailed by tetrodotoxin and enhanced by 10 pM dexamethasone. Tyrosine hydroxylase mRNA content was not significantly modified by depolarization, even in the presence of 1 μM dexamethasone. Aldosterone, progesterone, testosterone, or estradiol (1 μM) failed to change proenkephalin mRNA. Hence, dexamethasone appears to exert a specific permissive action on the stimulation of the proenkephalin gene elicited by depolarization. Though the catecholamines and enkephalins are localized in the same chromaffin granules and are coreleased by depolarization, the genes coding for the processes that are rate limiting in the production of these neuromodulators can be differentially regulated

  3. Late effects of low-dose ionizing radiation on man

    International Nuclear Information System (INIS)

    Brilliant, M.D.; Vorob'ev, A.I.; Gogin, E.E.

    1987-01-01

    One of the most important problems, being stated before the medicine by the accident, which took place in Chernobyl in 1986- the problem of the so-called ionizing radiation low dose effect on a man's organism, is considered because a lot of people were subjected to low dose action. The concept of low doses of radiaion action and specificity of its immediate action in comparison with high dose action is considered. One of the most important poit while studying low dose action is the necessity to develop a system including all irradiated people and dosimetry, and espicially to study frequencies and periods of tumor appearance in different irradiated tissues. The results obtained when examining people who survived the atomic explosion in Japan and on the Marshall islands are analyzed. They testify to the fact that radiation affets more tissues than the clinical picture about the acute radiation sickness tells, and that tumors developing in them many years after radiation action tell about radiosensitivity in some tissues

  4. A study on mice exposure dose for low-dose gamma-irradiation using glass dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sung Jin; Kim, Hyo Jin; Kim, Hyun; Jeong, Dong Hyeok; Son, Tae Gen; Kim, Jung Ki; Yang, Kwang Mo; Kang, Yeong Rok [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, Sang Hee [Dept. of Biomedical Engineering, Inje University, Gimhae (Korea, Republic of)

    2015-12-15

    The low dose radiation is done for a long period, thus researchers have to know the exact dose distribution for the irradiated mouse. This research has been conducted in order to find out methods in transmitting an exact dose to mouse in a mouse irradiation experiment carried out using {sup 137}C{sub s} irradiation equipment installed in the DIRAMS (Dongnam Institution of Radiological and Medical Sciences) research center. We developed a single mouse housing cage and shelf with adjustable geometric factors such as distance and angle from collimator. The measurement of irradiated dose showed a maximal 42% difference of absorbed dose from the desired dose in the conventional irradiation system, whereas only 6% difference of the absorbed dose was measured in the self-developed mouse apartment system. In addition, multi mice housing showed much difference of the absorbed dose in between head and body, compared to single mouse housing in the conventional irradiation system. This research may allow further research about biological effect assessment for the low dose irradiation using the self-developed mouse apartment to provide more exact doses which it tries to transmit, and to have more reliability for the biological analysis results.

  5. Removal of dexamethasone from aqueous solution and hospital wastewater by electrocoagulation

    International Nuclear Information System (INIS)

    Arsand, Daniel R.; Kümmerer, Klaus; Martins, Ayrton F.

    2013-01-01

    This study is concerned with the removal of the anti-inflammatory dexamethasone from aqueous solution and hospital wastewater by electrocoagulation. The variation of the toxicity during the electrocoagulation was also studied through experiments that were designed and optimized by means of response surface methodology. The coagulation efficiency was evaluated by measuring the dexamethasone concentration by high performance liquid chromatography coupled to a diode array detector. In addition, variation was evaluated through a Vibrio fischeri test. The results showed an increase in the removal of dexamethasone (up to 38.1%) with a rise of the current applied and a decrease of the inter-electrode distance, in aqueous solutions. The application to hospital effluent showed similar results for the removal of dexamethasone. The main effect of the electrocoagulation was that it removed colloids and reduced the organic load of the hospital wastewater. Regarding the current applied, the calculated energy efficiency was 100%. Without pH adjustment of the aqueous solution or hospital wastewater, the residual aluminum concentration always remained lower than 10 mg L −1 , and, with adjustment (to pH 6.5), lower than 0.30 mg L −1 , at the final stage. No toxicity variation was observed during the electrocoagulation process in aqueous solution, either in the presence or absence of dexamethasone. - Highlights: ► Removal of DEX and organic load from aqueous solution and hospital wastewater by EC ► Evaluation of the toxicity during the removal of DEX by EC ► Suggestion of the EC process as a pretreatment for subsequent processes

  6. Removal of dexamethasone from aqueous solution and hospital wastewater by electrocoagulation

    Energy Technology Data Exchange (ETDEWEB)

    Arsand, Daniel R., E-mail: danielarsand@pelotas.ifsul.edu.br [Chemistry Department, Federal University of Santa Maria, RS (Brazil); Kümmerer, Klaus, E-mail: klaus.kuemmerer@leuphana.de [Institute for Environmental Chemistry, Leuphana University Lüneburg (Germany); Martins, Ayrton F., E-mail: martins@quimica.ufsm.br [Chemistry Department, Federal University of Santa Maria, RS (Brazil)

    2013-01-15

    This study is concerned with the removal of the anti-inflammatory dexamethasone from aqueous solution and hospital wastewater by electrocoagulation. The variation of the toxicity during the electrocoagulation was also studied through experiments that were designed and optimized by means of response surface methodology. The coagulation efficiency was evaluated by measuring the dexamethasone concentration by high performance liquid chromatography coupled to a diode array detector. In addition, variation was evaluated through a Vibrio fischeri test. The results showed an increase in the removal of dexamethasone (up to 38.1%) with a rise of the current applied and a decrease of the inter-electrode distance, in aqueous solutions. The application to hospital effluent showed similar results for the removal of dexamethasone. The main effect of the electrocoagulation was that it removed colloids and reduced the organic load of the hospital wastewater. Regarding the current applied, the calculated energy efficiency was 100%. Without pH adjustment of the aqueous solution or hospital wastewater, the residual aluminum concentration always remained lower than 10 mg L{sup −1}, and, with adjustment (to pH 6.5), lower than 0.30 mg L{sup −1}, at the final stage. No toxicity variation was observed during the electrocoagulation process in aqueous solution, either in the presence or absence of dexamethasone. - Highlights: ► Removal of DEX and organic load from aqueous solution and hospital wastewater by EC ► Evaluation of the toxicity during the removal of DEX by EC ► Suggestion of the EC process as a pretreatment for subsequent processes.

  7. Dexamethasone and sodium carboxymethyl cellulose prevent postoperative intraperitoneal adhesions in rats

    Directory of Open Access Journals (Sweden)

    X.H. Du

    2015-04-01

    Full Text Available We aimed to evaluate the effects of the barrier agent sodium carboxymethyl cellulose (SCMC with and without dexamethasone for the prevention of postoperative adhesion formation in a rat model of postoperative peritoneal adhesion. A total of 160 three-month old male and female Wistar rats underwent a laparotomy, and adhesions were induced by ileocecal abrasion. Rats were randomly assigned to 4 groups (n=40 each: group A, untreated; group B, treated with SCMC only; group C1, treated with SCMC + 3 mg dexamethasone, and group C2, treated with SCMC + 8 mg dexamethasone. After 12 days, adhesion formation and histopathological changes were compared. In groups A, B, C1, and C2, the mortality rates were 10, 5, 5, and 5%, respectively. In groups C1 and C2, the adhesions were filmy and easy to dissect and were milder compared with those in groups A and B. The total adhesion score in group C1 (3.38±0.49 was significantly lower than that of group B (6.01±0.57; P<0.01 or group A (8.01±0.67; P<0.05. There was no significant difference in adhesion formation between groups C1 and C2. Compared with groups A and B, groups C1 and C2 exhibited milder histopathological changes. SCMC in combination with dexamethasone can prevent adhesion formation and is a better barrier agent than SCMC alone. The safety and feasibility of SCMC in combination with dexamethasone to prevent adhesion formation after abdominal surgery warrants further clinical study.

  8. 'Reasonable' regulation of low doses in the Netherlands?

    International Nuclear Information System (INIS)

    Zuur, Ciska

    2002-01-01

    As long as it is not clear exactly what the risks of low doses are, exposures should be regulated to be 'as low as reasonably achievable' (ALARA). In radiation protection, for normal situations, this means that a projected dose reduction can only be obligatory when the efforts needed to achieve the reduction are 'reasonable' in comparison with it, economical and social aspects being taken into account. In the recent Dutch regulations, 'reasonable' values have been established for the relevant parameters used in the ALARA concept and the paper discusses the values required to calculate the doses for the critical group due to a source. In some cases, the effort expended in making the ALARA dose assessments might not be reasonable in comparison with the dose reduction to be expected. The system which has been developed in the Netherlands to avoid these 'unreasonable' dose calculations, measurements and assessments is explained. (author)

  9. Cytogenetics dosimetry: dose-response curve for low doses of X-ray

    International Nuclear Information System (INIS)

    Lara, Virginia E. Noval; Pineda Bolivar, William R.; Riano, Victor M. Pabon; Ureana, Cecilia Crane

    2013-01-01

    The purpose of this study was to conduct a preliminary study for the standardization in the future, the dose-response curve for low doses of X-rays, through the analysis of in vitro cultures of peripheral blood samples of 3 men and 3 women occupationally not exposed to artificial sources of ionizing radiation, age 18-40 years, where possible nonsmokers

  10. Toxicity bioassay in mice exposed to low dose-rate radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joog Sun; Gong, Eun Ji; Heo, Kyu; Yang, Kwang Mo [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of)

    2013-04-15

    The systemic effect of radiation increases in proportion to the dose amount and rate. The association between accumulated radiation dose and adverse effects, which is derived according to continuous low dose-rate radiation exposure, is not clearly elucidated. Our previous study showed that low dose-rate radiation exposure did not cause adverse effects in BALB/c mice at dose levels of ≤2 Gy, but the testis weight decreased at a dose of 2 Gy. In this study, we studied the effects of irradiation at the low dose rate (3.49 mGy/h) in the testes of C57BL/6 mice. Mice exposed to a total dose of 0.02, 0.2, and 2 Gy were found to be healthy and did not show any significant changes in body weight and peripheral blood components. However, mice irradiated with a dose of 2 Gy had significantly decreased testis weight. Further, histological studies and sperm evaluation also demonstrated changes consistent with the findings of decreased testis weight. In fertile patients found to have arrest of sperm maturation, the seminiferous tubules lack the DNMT1 and HDAC1 protein. The decrease of DNMT1 and HDAC1 in irradiated testis may be the part of the mechanism via which low dose-rate irradiation results in teticular injury. In conclusion, despite a low dose-rate radiation, our study found that when mice testis were irradiated with 2 Gy at 3.49 mGy/h dose rate, there was significant testicular and sperm damage with decreased DNMT1 and HDAC1 expression.

  11. Implication of new CEC recommendations for individual monitoring for external radiation doses to the skin and the extremities

    International Nuclear Information System (INIS)

    Christensen, P.; Julius, H.W.; Marshall, T.O.

    1991-01-01

    A drafting group consisting of the above authors has assisted the CEC in revising the CEC document Technical Recommendations for Monitoring the Exposure to Individuals to External Radiation, EUR 5287, published in 1975. The paper highlights sections of the revised version relating particularly to irradiation of the skin and the extremities and focusses on problems connected to exposure to weakly penetrating radiations. Concepts of individual monitoring for external radiation exposures to the skin of the whole body and to the extremities are discussed and guidance is given as regards dose quantities and dosemeter calibration procedures. A method of quantifying the overall accuracy of the dose measurements as a result of the various uncertainty components connected with the dosimetry system is suggested and requirements on the accuracy of the dose measurements complying with the ICRP requirements on overall accuracy for individual monitoring are specified. Moreover, implications of the accuracy requirements for the design and type testing of the dosemeter are discussed. (author)

  12. Low-mass Stars with Extreme Mid-Infrared Excesses: Potential Signatures of Planetary Collisions

    Science.gov (United States)

    Theissen, Christopher; West, Andrew

    2018-01-01

    I investigate the occurrence of extreme mid-infrared (MIR) excesses, a tracer of large amounts of dust orbiting stars, in low-mass stellar systems. Extreme MIR excesses, defined as an excess IR luminosity greater than 1% of the stellar luminosity (LIR/L* ≥ 0.01), have previously only been observed around a small number of solar-mass (M⊙) stars. The origin of this excess has been hypothesized to be massive amounts of orbiting dust, created by collisions between terrestrial planets or large planetesimals. Until recently, there was a dearth of low-mass (M* ≤ 0.6M⊙) stars exhibiting extreme MIR excesses, even though low-mass stars are ubiquitous (~70% of all stars), and known to host multiple terrestrial planets (≥ 3 planets per star).I combine the spectroscopic sample of low-mass stars from the Sloan Digital Sky Survey (SDSS) Data Release 7 (70,841 stars) with MIR photometry from the Wide-field Infrared Survey Explorer (WISE), to locate stars exhibiting extreme MIR excesses. I find the occurrence frequency of low-mass field stars (stars with ages ≥ 1 Gyr) exhibiting extreme MIR excesses is much larger than that for higher-mass field stars (0.41 ± 0.03% versus 0.00067 ± 0.00033%, respectively).In addition, I build a larger sample of low-mass stars based on stellar colors and proper motions using SDSS, WISE, and the Two-Micron All-Sky Survey (8,735,004 stars). I also build a galactic model to simulate stellar counts and kinematics to estimate the number of stars missing from my sample. I perform a larger, more complete study of low-mass stars exhibiting extreme MIR excesses, and find a lower occurrence frequency (0.020 ± 0.001%) than found in the spectroscopic sample but that is still orders of magnitude larger than that for higher-mass stars. I find a slight trend for redder stars (lower-mass stars) to exhibit a higher occurrence frequency of extreme MIR excesses, as well as a lower frequency with increased stellar age. These samples probe important

  13. 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

  14. Rats Born to Mothers Treated with Dexamethasone 15 cH Present Changes in Modulation of Inflammatory Process

    Directory of Open Access Journals (Sweden)

    Leoni V. Bonamin

    2012-01-01

    Full Text Available As little information about the effect of ultra high dilutions of glucocorticoid in reproduction is available in the literature, pregnant female Wistar rats (N=12 were blindly subcutaneously treated during all gestational and lactation period with: dexamethasone 4 mg/kg diluted into dexamethasone 15 cH (mixed; or dexamethasone 4 mg/kg diluted in water; or dexamethasone 15 cH, or vehicle. Parental generation had body weight, food and water consumption monitored. The F1 generation was monitored regarding to newborn development. No birth occurred in both groups treated with dexamethasone 4 mg/kg. After 60 days from birth, 12 male F1 rats were randomly selected from each remaining group and inoculated subcutaneously with 1% carrageenan into the footpad, for evaluation of inflammatory performance. Edema and histopathology of the footpad were evaluated, using specific staining methods, immunohistochemistry and digital histomorphometry. Mothers treated with mixed dexamethasone presented reduced water consumption. F1 rats born to dexamethasone 15 cH treated females presented significant increase in mast cell degranulation, decrease in monocyte percentage, increase in CD18+ PMN cells, and early expression of ED2 protein, in relation to control. The results show that the exposure of parental generation to highly diluted dexamethasone interferes in inflammation modulation in the F1 generation.

  15. Estimates of Health Detriments and Tissue Weighting Factors for Hong Kong Populations from Low Dose, Low Dose Rate and Low LET Ionising Radiation Exposure

    International Nuclear Information System (INIS)

    Lee, S.K.

    1998-01-01

    The total health detriments and the tissue weighting factors for the Hong Kong populations from low dose, low dose rate and low LET ionising radiation exposure are obtained according to the methodology recommended in ICRP Publication 60. The probabilities of fatal cancers for the general (ages 0-90) and working (ages 20-64) populations due to lifetime exposure at low dose and low dose rate are 4.9 x 10 -2 Sv -1 and 3.6 x 10 -2 Sv -1 respectively, comparing with the ICRP 60 estimates of 5.0 x 10 -2 Sv -1 and 4.0 x 10 -2 Sv -1 . The corresponding total health detriments for the general and working populations are 6.9 x 10 -2 Sv -1 and 4.9 x 10 -2 Sv -1 respectively comparing with the ICRP 60 estimates of 7.3 x 10 -2 Sv -1 and 5.6 x 10 -2 Sv -1 . Tissue weighting factors for the general population are 0.01 (bone surface and skin), 0.02 (liver, oesophagus and thyroid), 0.04 (bladder and breast), 0.08 (remainder), 0.10 (stomach), 0.11 (bone marrow), 0.15 (colon), 0.19 (lung) and 0.21 (gonads) and for the working population are 0.01 (bone surface and skin), 0.03 (liver, oesophagus and thyroid), 0.04 (breast), 0.06 (remainder), 0.07 (bladder), 0.08 (colon), 0.14 (bone marrow and stomach), 0.16 (lung) and 0.20 (gonads). (author)

  16. Cellular Stress to Low Gamma-ray Dose

    International Nuclear Information System (INIS)

    Manzanares-Acuna, E.; Vega-Carrillo, H. R.; Letechipia de Leon, C.; Guzman Enriquez, L. J.; Garcia-Talavera, M.

    2004-01-01

    The purpose of this study was to evaluate the effect of low gamma ray intensity upon Hsp 70 expression in human lymphocytes. the heat shock proteins (Hsp) family, are a group of proteins present in all living organism, therefore there are highly conserved and are related to adaptation and evolution. At cellular level these proteins acts as chaperones correcting denatured proteins. when a stress agent, such heavy metals, UV, heat, etc. is affecting a cell a response to this aggression is triggered through overexpression of Hsp. Several studies has been carried out in which the cellular effect are observed, mostly of these studies uses large doses, but very few studies are related with low doses. Blood of healthy volunteers was obtained and the lymphocytes were isolated by ficoll-histopaque gradient. Experimental lots were irradiated in a ''137Cs gamma-ray. Hsp70 expression was found since 0.5 cGy, indicating a threshold to very low doses of gamma rays. (Author) 27 refs

  17. Low-Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James; Slovic, Paul

    2001-01-01

    To conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low dose exposures. This involves the study of existing knowledge and the evaluation of science information presented within a variety of formats, as educational information, news media stories, and alternative communication methods (personal contact, small group interaction, email and internet, etc.). Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low- dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  18. Aprepitant, granisetron, and dexamethasone versus palonosetron and dexamethasone for prophylaxis of cisplatin-induced nausea and vomiting in patients with upper gastrointestinal cancer: a randomized crossover phase II trial (KDOG 1002).

    Science.gov (United States)

    Ishido, Kenji; Higuchi, Katsuhiko; Azuma, Mizutomo; Sasaki, Tohru; Tanabe, Satoshi; Katada, Chikatoshi; Yano, Takafumi; Wada, Takuya; Koizumi, Wasaburo

    2016-10-01

    We conducted a randomized trial to compare the safety and effectiveness of aprepitant, granisetron, and dexamethasone (AGD) with those of palonosetron and dexamethasone (PD) in patients who received highly emetogenic chemotherapy (HEC). Patients with esophageal or gastric cancer who were scheduled to receive HEC including at least 60 mg/m of cisplatin as the first-line treatment were randomly assigned to receive AGD (oral aprepitant 125 mg on day 1 and 80 mg on days 2-3; intravenous granisetron 3 mg on day 1; intravenous dexamethasone 6.6 mg on day 1 and oral dexamethasone 4 mg on days 2-3) or PD (intravenous palonosetron 0.75 mg on day 1; intravenous dexamethasone 13.2 mg on day 1 and oral dexamethasone 8 mg on days 2-3). The primary endpoint was a complete response during the overall study period (0-120 h after the start of chemotherapy) in the first cycle. Eighty-five patients were enrolled, and 84 were eligible. The complete response rate did not differ between the treatment groups, but the proportion of patients with no vomiting was significantly higher in the AGD group than in the PD group (81.4 vs. 58.5%; P=0.031). The results of a quality-of-life survey indicated that the proportion of patients with no or minimal impact on daily life in the vomiting domain was significantly higher in the AGD group (79.1 vs. 53.7%; P=0.020). The primary endpoint of complete response was not achieved, but AGD seems to be more effective than PD for the prevention of HEC-induced vomiting.

  19. Health hazards of low doses of ionizing radiations. Vo. 1

    International Nuclear Information System (INIS)

    El-Naggar, M.A.

    1996-01-01

    Exposure to high doses of ionizing radiation results in clinical manifestations of several disease entities that may be fatal. The onset and severity of these acute radiation syndromes are deterministic in relation to dose magnitude. Exposure to ionizing radiations at low doses and low dose rates could initiate certain damage in critical molecules of the cell, that may develop in time into serious health effects. The incidence of such delayed effects in low, and is only detectable through sophisticated epidemiological models carried out on large populations. The radiation damage induced in critical molecules of cells may develop by stochastic biochemical mechanisms of repair, residual damage, adaptive response, cellular transformation, promotion and progression into delayed health effects, the most important of which is carcinogenesis. The dose response relationship of probabilistic stochastic delayed effects of radiation at low doses and low dose rates, is very complex indeed. The purpose of this review is to provide a comprehensive understanding of the underlying mechanisms, the factors involved, and the uncertainties encountered. Contrary to acute deterministic effects, the occurrence of probabilistic delayed effects of radiation remains to be enigmatic. 7 figs

  20. Under-reported dosimetry errors due to interplay effects during VMAT dose delivery in extreme hypofractionated stereotactic radiotherapy.

    Science.gov (United States)

    Gauer, Tobias; Sothmann, Thilo; Blanck, Oliver; Petersen, Cordula; Werner, René

    2018-06-01

    Radiotherapy of extracranial metastases changed from normofractioned 3D CRT to extreme hypofractionated stereotactic treatment using VMAT beam techniques. Random interaction between tumour motion and dynamically changing beam parameters might result in underdosage of the CTV even for an appropriately dimensioned ITV (interplay effect). This study presents a clinical scenario of extreme hypofractionated stereotactic treatment and analyses the impact of interplay effects on CTV dose coverage. For a thoracic/abdominal phantom with an integrated high-resolution detector array placed on a 4D motion platform, dual-arc treatment plans with homogenous target coverage were created using a common VMAT technique and delivered in a single fraction. CTV underdosage through interplay effects was investigated by comparing dose measurements with and without tumour motion during plan delivery. Our study agrees with previous works that pointed out insignificant interplay effects on target coverage for very regular tumour motion patterns like simple sinusoidal motion. However, we identified and illustrated scenarios that are likely to result in a clinically relevant CTV underdosage. For tumour motion with abnormal variability, target coverage quantified by the CTV area receiving more than 98% of the prescribed dose decreased to 78% compared to 100% at static dose measurement. This study is further proof of considerable influence of interplay effects on VMAT dose delivery in stereotactic radiotherapy. For selected conditions of an exemplary scenario, interplay effects and related motion-induced target underdosage primarily occurred in tumour motion pattern with increased motion variability and VMAT plan delivery using complex MLC dose modulation.

  1. Bilateral Intravitreal Dexamethasone Implant for Retinitis Pigmentosa-Related Macular Edema

    Directory of Open Access Journals (Sweden)

    Ali Osman Saatci

    2013-03-01

    Full Text Available Purpose: To report the efficacy of intravitreal dexamethasone implant in a patient with retinitis pigmentosa and bilateral cystoid macular edema unresponsive to topical carbonic anhydrase inhibitors. Case Report: A 36-year-old man with bilateral cystoid macular edema associated with retinitis pigmentosa that was unresponsive to topical carbonic anhydrase inhibitors underwent bilateral 0.7-mg intravitreal dexamethasone implants two weeks apart. Spectral domain optical coherence tomography revealed resolution of macular edema one week following each injection in both eyes and his visual acuity improved. However, macular edema recurred two months later in OS and three months later in OD. Second implant was considered for both eyes. No implant-related complication was experienced during the follow-up of seven months. Conclusion: Inflammatory process seems to play a role in retinitis pigmentosa. Intravitreal dexamethasone implant may offer retina specialists a therapeutic option especially in cases unresponsive to other treatment regimens in eyes with retinitis pigmentosa-related macular edema.

  2. Feasibility of extreme dose escalation for glioblastoma multiforme using 4π radiotherapy

    International Nuclear Information System (INIS)

    Nguyen, Dan; Rwigema, Jean-Claude M; Yu, Victoria Y; Kaprealian, Tania; Kupelian, Patrick; Selch, Michael; Lee, Percy; Low, Daniel A; Sheng, Ke

    2014-01-01

    be tolerated when delivered in proportionally increased treatment fractions. Therefore, 4π non-coplanar radiotherapy on C-arm gantry may provide an accessible tool to improve the outcome of GBM radiotherapy through extreme dose escalation

  3. Implications of effects ''adaptive response'', ''low-dose hypersensitivity'' und ''bystander effect'' for cancer risk at low doses and low dose rates

    International Nuclear Information System (INIS)

    Jacob, P

    2006-01-01

    A model for carcinogenesis (the TSCE model) was applied in order to examine the effects of ''Low-dose hypersensitivity (LDH)'' and the ''Bystander effect (BE)'' on the derivation of radiation related cancer mortality risks. LDH has been discovered to occur in the inactivation of cells after acute exposure to low LET radiation. A corresponding version of the TSCE model was applied to the mortality data on the Abomb survivors from Hiroshima and Nagasaki. The BE has been mainly observed in cells after exposure to high LET radiation. A Version of the TSCE model which included the BE was applied to the data on lung cancer mortality from the workers at the Mayak nuclear facilities who were exposed to Plutonium. In general an equally good description of the A-bomb survivor mortality data (for all solid, stomach and lung tumours) was found for the TSCE model and the (conventional) empirical models but fewer parameters were necessary for the TSCE model. The TSCE model which included the effects of radiation induced cell killing resulted in non-linear dose response curves with excess relative risks after exposure at young ages that were generally lower than in the models without cell killing. The main results from TSCE models which included cell killing described by either conventional survival curves or LDH were very similar. A sub multiplicative effect from the interaction of smoking and exposure to plutonium was found to result from the analysis of the Mayak lung cancer mortality data. All models examined resulted in the predominant number of Mayak lung cancer deaths being ascribed to smoking. The interaction between smoking and plutonium exposures was found to be the second largest effect. The TSCE model resulted in lower estimates for the lung cancer excess relative risk per unit plutonium dose than the empirical risk model, but this difference was not found to be statistically significant. The excess relative risk dose responses were linear in the empirical model and

  4. Dexamethasone-(C21-phosphoramide)-[anti-EGFR]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency against pulmonary adenocarcinoma (A549).

    Science.gov (United States)

    Coyne, Cody P; Narayanan, Lakshmi

    2016-01-01

    Corticosteroids are effective in the management of a variety of disease states, such as several forms of neoplasia (leukemia and lymphoma), autoimmune conditions, and severe inflammatory responses. Molecular strategies that selectively "target" delivery of corticosteroids minimize or prevents large amounts of the pharmaceutical moiety from passively diffusing into normal healthy cell populations residing within tissues and organ systems. The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR] was synthesized by reacting dexamethasone-21-monophosphate with a carbodiimide reagent to form a dexamethasone phosphate carbodiimide ester that was subsequently reacted with imidazole to create an amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate. Monoclonal anti-EGFR immunoglobulin was combined with the amine-reactive dexamethasone-(C21-phosphorylimidazolide) intermediate, resulting in the synthesis of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide)-[anti-EGFR]. Following spectrophotometric analysis and validation of retained epidermal growth factor receptor type 1 (EGFR)-binding avidity by cell-ELISA, the selective anti-neoplasic cytotoxic potency of dexamethasone-(C21-phosphoramide)-[anti-EGFR] was established by MTT-based vitality stain methodology using adherent monolayer populations of human pulmonary adenocarcinoma (A549) known to overexpress the tropic membrane receptors EGFR and insulin-like growth factor receptor type 1. The dexamethasone:IgG molar-incorporation-index for dexamethasone-(C21-phosphoramide)-[anti-EGFR] was 6.95:1 following exhaustive serial microfiltration. Cytotoxicity analysis: covalent bonding of dexamethasone to monoclonal anti-EGFR immunoglobulin did not significantly modify the ex vivo antineoplastic cytotoxicity of dexamethasone against pulmonary adenocarcinoma at and between the standardized dexamethasone equivalent concentrations of 10(-9) M and 10(-5) M. Rapid increases in

  5. Analysis of final products from the liquid alkanes radiolysis at low dose, low temperature and high dose rate

    International Nuclear Information System (INIS)

    Tilquin, B.; Doncker, J. de.

    1991-01-01

    Yields of final products (dimers) from the radiolysis of n-hexane and 2,3-dimethylbutane are studied by capillary chromatographic techniques for trace analysis. Reaction of intermediates with the products, the alkane molecules or impurities, is reduced by using low dose (1 kGy), low temperature (195 K) and high dose rate (LINAC). Temperature is the most important experiment variable; by reducing the temperature, reactions with significant activation energies do not compete with radical-radical termination reactions. Products from LINAC radiolysis provide information about active species (reactive fragment, allylic radical...) which deserve a more detailed examination by direct methods [fr

  6. Statistical and low dose response

    International Nuclear Information System (INIS)

    Thorson, M.R.; Endres, G.W.R.

    1981-01-01

    The low dose response and the lower limit of detection of the Hanford dosimeter depend upon may factors, including the energy of the radiation, whether the exposure is to be a single radiation or mixed fields, annealing cycles, environmental factors, and how well various batches of TLD materials are matched in the system. A careful statistical study and sensitivity analysis were performed to determine how these factors influence the response of the dosimeter system. Estimates have been included in this study of the standard deviation of calculated dose for various mixed field exposures from 0 to 1000 mrem

  7. DOES THE ADDITION OF DEXAMETHASON TO LOCAL ANESTHETIC PROLONG THE ANALGESIA OF INTERSCALEN PLEXUS BRACHIALIS BLOCK IN PATIENTS WITH SHOULDER SURGERY?

    Directory of Open Access Journals (Sweden)

    Nancheva Jasminka

    2016-07-01

    Full Text Available Abstract: Introduction: Peripherial nerve blocks is a suitable alternative to general anesthesia especially for one-day case surgery. Interscalene approach of plexus brachialis block as much as supraclavicular and infraclavicular provide reliable, safe, effective, low cost and most complete anesthesia with satisfactory postoperative analgesia for upper limb surgery. Postoperative analgesia of plexus brachialis blocks can be prolonged by using different drugs as adjuvants with local anesthetics. Dexamethasone has been shown to prolong the duration of postoperative analgesia when given as an adjunct for peripheral nerve blocks. The investigation was randomized, prospective, double blinded and controlled study. Objective: The study was designed to compare the effects of dexamethasone administered as an adjunct to bupivacaine in interscalene brachial plexus block on the onset, duration and postoperative analgesia in patients under the shoulder surgery. Methods: A prospective, double-blind study was undertaken in patients scheduled for shoulder surgeries under the interscalene brachial plexus block. We enrolled 60 patients, ASA I-II both sexes, aged 19-65 years, weighing 54-89 kg, divided to two groups G1 and G2. The brachial plexus block was performed by interscalene approach and mixture of 2% lidocaine (12ml and 0.5% bupivacaine (22 ml either alone or combined with dexamethasone (4 mg. The block was performed by using double technique neurostimulator/ultrasound technique. Results: In our investigation we found a significant increase in onset and duration of motor and sensory block in Group G2 (with dexamethasone as compared to Group G1 patients (p < 0.01. Conclusion: Addition of dexamethasone to local anesthetic drugs in interscalene plexus brachialis block, significantly prolongs the duration of analgesia and motor block in patients undergoing shoulder arthroscopy. Moreover, it is a remarkably safe and costeffective method of providing

  8. Mechanisms of Low Dose Radio-Suppression of Genomic Instability

    Energy Technology Data Exchange (ETDEWEB)

    Engelward, Bevin P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2009-09-16

    The major goal of this project is to contribute toward the elucidation of the impact of long term low dose radiation on genomic stability. We have created and characterized novel technologies for delivering long term low dose radiation to animals, and we have studied genomic stability by applying cutting edge molecular analysis technologies. Remarkably, we have found that a dose rate that is 300X higher than background radiation does not lead to any detectable genomic damage, nor is there any significant change in gene expression for genes pertinent to the DNA damage response. These results point to the critical importance of dose rate, rather than just total dose, when evaluating public health risks and when creating regulatory guidelines. In addition to these studies, we have also further developed a mouse model for quantifying cells that have undergone a large scale DNA sequence rearrangement via homologous recombination, and we have applied these mice in studies of both low dose radiation and space radiation. In addition to more traditional approaches for assessing genomic stability, we have also explored radiation and possible beneficial effects (adaptive response), long term effects (persistent effects) and effects on communication among cells (bystander effects), both in vitro and in vivo. In terms of the adaptive response, we have not observed any significant induction of an adaptive response following long term low dose radiation in vivo, delivered at 300X background. In terms of persistent and bystander effects, we have revealed evidence of a bystander effect in vivo and with researchers at and demonstrated for the first time the molecular mechanism by which cells “remember” radiation exposure. Understanding the underlying molecular mechanisms by which radiation can induce genomic instability is fundamental to our ability to assess the biological impact of low dose radiation. Finally, in a parallel set of studies we have explored the effects of heavy

  9. Low-dose radiation induces drosophila innate immunity through toll pathway activation

    International Nuclear Information System (INIS)

    Seong, Ki Moon; Kim, Cha Soon; Lee, Byung-Sub; Nam, Seon Young; Yang, Kwang Hee; Kim, Ji-Young; Jin, Young-Woo; Park, Joong-Jean; Min, Kyung-Jin

    2012-01-01

    Numerous studies report that exposing certain organisms to low-dose radiation induces beneficial effects on lifespan, tumorigenesis, and immunity. By analyzing survival after bacterial infection and antimicrobial peptide gene expression in irradiated flies, we demonstrate that low-dose irradiation of Drosophila enhances innate immunity. Low-dose irradiation of flies significantly increased resistance against gram-positive and gram-negative bacterial infections, as well as expression of several antimicrobial peptide genes. Additionally, low-dose irradiation also resulted in a specific increase in expression of key proteins of the Toll signaling pathway and phosphorylated forms of p38 and N-terminal kinase (JNK). These results indicate that innate immunity is activated after low-dose irradiation through Toll signaling pathway in Drosophila. (author)

  10. High doses of corticosteroid suppress resistance to Ichthyophonus in starry flounder

    Science.gov (United States)

    Perry, J.A.; Kocan, R.M.; Winton, J.R.; Hershberger, P.K.

    2004-01-01

    Application of pharmacological doses of the corticosteroid dexamethasone phosphate to starry flounder Platichthys stellatus resulted in a predisposition to clinical ichthyophoniasis and a progression from latent Ichthyophonus infections to patent, histologically identifiable infections. Among Ichthyophonus-challenged starry flounder, the prevalences of clinical infections and histologically identifiable infections were significantly greater in two groups that received dexamethasone (100% and 31%, respectively) than in the respective control groups (8% and 0%). Proliferation of Ichthyophonus infections in corticosteroid-treated groups may have resulted from suppression of the cellular immune response that typically follows corticosteroid application; however, further studies are needed to determine whether these effects occur at lower, physiological concentrations of corticosteroids.

  11. The role of adjunctive dexamethasone in the treatment of bacterial meningitis: an updated systematic meta-analysis

    Directory of Open Access Journals (Sweden)

    Shao M

    2016-07-01

    Full Text Available Mei Shao,1 Peng Xu,2 Jun Liu,3 Wenyun Liu,1 Xiujie Wu1 1Department of Neurosurgery, Linyi People’s Hospital, 2Department of Neurosurgery, Linyi Yishui Central Hospital, Linyi, 3Department of Neurosurgery, Binzhou Medical College, Yantai, Shandong, People’s Republic of China Background: Bacterial meningitis is a serious infection in children and adults worldwide, with considerable morbidity, mortality, and severe neurological sequelae. Dexamethasone is often used before antibiotics in cases of this disease, and improves outcomes.Objective: Although several studies have identified the role of adjunctive dexamethasone therapy in the treatment of bacterial meningitis, the results are still inconclusive. The aim of this study was to systematically evaluate the therapeutic and adverse effect of adjunctive dexa­methasone in patients with bacterial meningitis.Materials and methods: Relevant randomized, double-blind, placebo-controlled trials of dexamethasone in bacterial meningitis published between 2000 and 2016 were retrieved from the common electronic databases. The odds ratio (OR and risk ratio (RR with their 95% confidence interval (CI were employed to calculate the effect.Results: A total of ten articles including 2,459 bacterial meningitis patients (1,245 in the dexamethasone group and 1,214 in the placebo group were included in this meta-analysis. Our result found that dexamethasone was not associated with a significant reduction in follow-up mortality (292 of 1,245 on dexamethasone versus 314 of 1,214 on placebo; OR =0.91, 95% CI =0.80–1.03, P=0.14 and severe neurological sequelae (22.4% versus 24.1%, OR =0.84, 95% CI =0.54–1.29, P=0.42. However, dexamethasone seemed to reduce hearing loss among survivors (21.2% versus 26.1%; OR =0.76, 95% CI =0.59–0.98, P=0.03. No significant difference was found between these two groups in adverse events.Conclusion: Our results suggested that adjunctive dexamethasone might not be beneficial in the

  12. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C.; Meer, Berend van; Ward-van Oostwaard, Dorien [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); Passier, Robert [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); MIRA, University of Twente (Netherlands); Tertoolen, Leon G.J.; Mummery, Christine L. [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands); Casini, Simona, E-mail: s.casini@amc.uva.nl [Department of Anatomy and Embryology, Leiden University Medical Center, Leiden (Netherlands)

    2015-11-27

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. - Highlights: • Dexamethasone accelerates Ca{sup 2+} transient decay in hESC-CMs. • Dexamethasone enhances SERCA and NCX function in hESC-CMs. • Dexamethasone increases force of contraction and sarcomere length in hESC-CMs. • Dexamethasone does not alter I{sub Ca,L} and action potential characteristics in hESC-CMs.

  13. Altered calcium handling and increased contraction force in human embryonic stem cell derived cardiomyocytes following short term dexamethasone exposure

    International Nuclear Information System (INIS)

    Kosmidis, Georgios; Bellin, Milena; Ribeiro, Marcelo C.; Meer, Berend van; Ward-van Oostwaard, Dorien; Passier, Robert; Tertoolen, Leon G.J.; Mummery, Christine L.; Casini, Simona

    2015-01-01

    One limitation in using human pluripotent stem cell derived cardiomyocytes (hPSC-CMs) for disease modeling and cardiac safety pharmacology is their immature functional phenotype compared with adult cardiomyocytes. Here, we report that treatment of human embryonic stem cell derived cardiomyocytes (hESC-CMs) with dexamethasone, a synthetic glucocorticoid, activated glucocorticoid signaling which in turn improved their calcium handling properties and contractility. L-type calcium current and action potential properties were not affected by dexamethasone but significantly faster calcium decay, increased forces of contraction and sarcomeric lengths, were observed in hESC-CMs after dexamethasone exposure. Activating the glucocorticoid pathway can thus contribute to mediating hPSC-CMs maturation. - Highlights: • Dexamethasone accelerates Ca"2"+ transient decay in hESC-CMs. • Dexamethasone enhances SERCA and NCX function in hESC-CMs. • Dexamethasone increases force of contraction and sarcomere length in hESC-CMs. • Dexamethasone does not alter I_C_a_,_L and action potential characteristics in hESC-CMs.

  14. The health effects of low-dose ionizing radiation

    International Nuclear Information System (INIS)

    Dixit, A.N.; Dixit, Nishant

    2012-01-01

    It has been established by various researches, that high doses of ionizing radiation are harmful to health. There is substantial controversy regarding the effects of low doses of ionizing radiation despite the large amount of work carried out (both laboratory and epidemiological). Exposure to high levels of radiation can cause radiation injury, and these injuries can be relatively severe with sufficiently high radiation doses. Prolonged exposure to low levels of radiation may lead to cancer, although the nature of our response to very low radiation levels is not well known at this time. Many of our radiation safety regulations and procedures are designed to protect the health of those exposed to radiation occupationally or as members of the public. According to the linear no-threshold (LNT) hypothesis, any amount, however small, of radiation is potentially harmful, even down to zero levels. The threshold hypothesis, on the other hand, emphasizes that below a certain threshold level of radiation exposure, any deleterious effects are absent. At the same time, there are strong arguments, both experimental and epidemiological, which support the radiation hormesis (beneficial effects of low-level ionizing radiation). These effects cannot be anticipated by extrapolating from harmful effects noted at high doses. Evidence indicates an inverse relationship between chronic low-dose radiation levels and cancer incidence and/or mortality rates. Examples are drawn from: 1) state surveys for more than 200 million people in the United States; 2) state cancer hospitals for 200 million people in India; 3) 10,000 residents of Taipei who lived in cobalt-60 contaminated homes; 4) high-radiation areas of Ramsar, Iran; 5) 12 million person-years of exposed and carefully selected control nuclear workers; 6) almost 300,000 radon measurements of homes in the United States; and 7) non-smokers in high-radon areas of early Saxony, Germany. This evidence conforms to the hypothesis that

  15. Problems linked to effects of ionizing radiations low doses

    International Nuclear Information System (INIS)

    Anon.

    1995-10-01

    The question of exposure to ionizing radiations low doses and risks existing for professional and populations has been asked again, with the recommendations of the International Commission of Radiation Protection (ICRP) to lower the previous standards and agreed as guides to organize radiation protection, by concerned countries and big international organisms. The sciences academy presents an analysis which concerned on epidemiological and dosimetric aspects in risk estimation, on cellular and molecular aspects of response mechanism to irradiation. The observation of absence of carcinogen effects for doses inferior to 200 milli-sieverts and a re-evaluation of data coming from Nagasaki and Hiroshima, lead to revise the methodology of studies to pursue, to appreciate more exactly the effects of low doses, in taking in part, particularly, the dose rate. The progress of molecular and cellular biology showed that the extrapolation from high doses to low doses is not in accordance with actual data. The acknowledge of DNA repair and carcinogenesis should make clearer the debate. (N.C.). 61 refs., 9 annexes

  16. New approach for food allergy management using low-dose oral food challenges and low-dose oral immunotherapies.

    Science.gov (United States)

    Yanagida, Noriyuki; Okada, Yu; Sato, Sakura; Ebisawa, Motohiro

    2016-04-01

    A number of studies have suggested that a large subset of children (approximately 70%) who react to unheated milk or egg can tolerate extensively heated forms of these foods. A diet that includes baked milk or egg is well tolerated and appears to accelerate the development of regular milk or egg tolerance when compared with strict avoidance. However, the indications for an oral food challenge (OFC) using baked products are limited for patients with high specific IgE values or large skin prick test diameters. Oral immunotherapies (OITs) are becoming increasingly popular for the management of food allergies. However, the reported efficacy of OIT is not satisfactory, given the high frequency of symptoms and requirement for long-term therapy. With food allergies, removing the need to eliminate a food that could be consumed in low doses could significantly improve quality of life. This review discusses the importance of an OFC and OIT that use low doses of causative foods as the target volumes. Utilizing an OFC or OIT with a low dose as the target volume could be a novel approach for accelerating the tolerance to causative foods. Copyright © 2015 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  17. The experimental study of the effect of dexamethasone, lidocaine and contrast medium on the activity of collagenase

    International Nuclear Information System (INIS)

    Wu Zhiqun; Liu Weimin; Li Zhonghua; Yang Peng

    2007-01-01

    Objective: To study the effects of hormone, anesthetic and contrast medium on the activities of collagenase lysis. Methods: Nuclear tissues were divided into equal amount for different groups and same units of collagenase were used for the lysis. The only difference in the control group from experimental groups was that there were no dexamethasone, lidocaine or omnipaque but existing in experimental groups. Twenty four hours later, the concentrations of the hydroxyproline were determined in different groups and the data were analyzed by statistical software with computer. Results: 1. The concentrations of hydroxyproline in the dexamethasone group, lidocaine group and omnipaque group were significantly lower than that of control group, especially that of lidocaine group, P value was <0.05 or 0.01. 2. The concentrations of hydroxyproline in the dexamethasone + lidocaine group, dexamethasone + omnipaque group, lidocaine+omnipaque group and dexamethasone + lidocaine + omnipaque group were significantly lower than that of control group; and simultaneously lower in dexamethasone group, lidocaine group, omnipaque group respectively; P value was also <0.05 or 0.01. Conclusion: Dexamethasone, lidocaine and omnipaque can individually inhibit the activity of collagenase at different degrees, so they shouldn't be used together with collagenase in treating the lumber disc herniation. (authors)

  18. Parotid gland mean dose as a xerostomia predictor in low-dose domains.

    Science.gov (United States)

    Gabryś, Hubert Szymon; Buettner, Florian; Sterzing, Florian; Hauswald, Henrik; Bangert, Mark

    2017-09-01

    Xerostomia is a common side effect of radiotherapy resulting from excessive irradiation of salivary glands. Typically, xerostomia is modeled by the mean dose-response characteristic of parotid glands and prevented by mean dose constraints to either contralateral or both parotid glands. The aim of this study was to investigate whether normal tissue complication probability (NTCP) models based on the mean radiation dose to parotid glands are suitable for the prediction of xerostomia in a highly conformal low-dose regime of modern intensity-modulated radiotherapy (IMRT) techniques. We present a retrospective analysis of 153 head and neck cancer patients treated with radiotherapy. The Lyman Kutcher Burman (LKB) model was used to evaluate predictive power of the parotid gland mean dose with respect to xerostomia at 6 and 12 months after the treatment. The predictive performance of the model was evaluated by receiver operating characteristic (ROC) curves and precision-recall (PR) curves. Average mean doses to ipsilateral and contralateral parotid glands were 25.4 Gy and 18.7 Gy, respectively. QUANTEC constraints were met in 74% of patients. Mild to severe (G1+) xerostomia prevalence at both 6 and 12 months was 67%. Moderate to severe (G2+) xerostomia prevalence at 6 and 12 months was 20% and 15%, respectively. G1 + xerostomia was predicted reasonably well with area under the ROC curve ranging from 0.69 to 0.76. The LKB model failed to provide reliable G2 + xerostomia predictions at both time points. Reduction of the mean dose to parotid glands below QUANTEC guidelines resulted in low G2 + xerostomia rates. In this dose domain, the mean dose models predicted G1 + xerostomia fairly well, however, failed to recognize patients at risk of G2 + xerostomia. There is a need for the development of more flexible models able to capture complexity of dose response in this dose regime.

  19. Increased cortisol responsivity to adrenocorticotropic hormone and low plasma levels of interleukin-1 receptor antagonist in women with functional hypothalamic amenorrhea.

    Science.gov (United States)

    Lindahl, Magnus S; Olovsson, Matts; Nyberg, Sigrid; Thorsen, Kim; Olsson, Tommy; Sundström Poromaa, Inger

    2007-01-01

    To assess the hypothalamic-pituitary-adrenal (HPA) axis at all levels, to determine the origin of the previously reported hypercortisolism in patients with functional hypothalamic amenorrhea. A secondary aim was to evaluate factors outside the central nervous system which are known to affect the HPA axis, i.e., circulating levels of interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1Ra), and fat mass-adjusted leptin levels, in patients with functional hypothalamic amenorrhea and healthy controls. Cross-sectional study. Umeå University Hospital, Umeå, Sweden. Fifteen subjects with hypothalamic amenorrhea, and 14 age- and weight-matched controls. None. We collected blood samples four times during a 24-hour interval for analysis of cortisol, leptin, IL-1Ra, and IL-6 levels. We performed a low-dose oral dexamethasone test and a low-dose ACTH test. We measured body-fat percentage using a dual-energy X-ray absorptiometer. Patients with hypothalamic amenorrhea had increased diurnal cortisol levels (P<.001). The cortisol response to intravenous low-dose ACTH was increased in functional hypothalamic amenorrhea patients compared to control subjects (P<.01), but they had similar rates of dexamethasone suppression. Patients with hypothalamic amenorrhea also had decreased diurnal leptin (P<.05), and decreased diurnal IL-1Ra levels (P<.05), compared to controls. Body-fat percentage was the main predictor of leptin levels. The present study suggests novel links for the development of functional hypothalamic amenorrhea, including increased adrenal responsiveness and impairments in proinflammatory cytokine pathways.

  20. Dexamethasone-mediated inhibition of Glioblastoma neurosphere dispersal in an ex vivo organotypic neural assay

    Science.gov (United States)

    Meleis, Ahmed M.; Mahtabfar, Aria; Danish, Shabbar

    2017-01-01

    Glioblastoma is highly aggressive. Early dispersal of the primary tumor renders localized therapy ineffective. Recurrence always occurs and leads to patient death. Prior studies have shown that dispersal of Glioblastoma can be significantly reduced by Dexamethasone (Dex), a drug currently used to control brain tumor related edema. However, due to high doses and significant side effects, treatment is tapered and discontinued as soon as edema has resolved. Prior analyses of the dispersal inhibitory effects of Dex were performed on tissue culture plastic, or polystyrene filters seeded with normal human astrocytes, conditions which inherently differ from the parenchymal architecture of neuronal tissue. The aim of this study was to utilize an ex-vivo model to examine Dex-mediated inhibition of tumor cell migration from low-passage, human Glioblastoma neurospheres on multiple substrates including mouse retina, and slices of mouse, pig, and human brain. We also determined the lowest possible Dex dose that can inhibit dispersal. Analysis by Two-Factor ANOVA shows that for GBM-2 and GBM-3, Dex treatment significantly reduces dispersal on all tissue types. However, the magnitude of the effect appears to be tissue-type specific. Moreover, there does not appear to be a difference in Dex-mediated inhibition of dispersal between mouse retina, mouse brain and human brain. To estimate the lowest possible dose at which Dex can inhibit dispersal, LogEC50 values were compared by Extra Sum-of-Squares F-test. We show that it is possible to achieve 50% reduction in dispersal with Dex doses ranging from 3.8 x10-8M to 8.0x10-9M for GBM-2, and 4.3x10-8M to 1.8x10-9M for GBM-3, on mouse retina and brain slices, respectively. These doses are 3-30-fold lower than those used to control edema. This study extends our previous in vitro data and identifies the mouse retina as a potential substrate for in vivo studies of GBM dispersal. PMID:29040322

  1. Dexamethasone-mediated inhibition of Glioblastoma neurosphere dispersal in an ex vivo organotypic neural assay.

    Directory of Open Access Journals (Sweden)

    Ahmed M Meleis

    Full Text Available Glioblastoma is highly aggressive. Early dispersal of the primary tumor renders localized therapy ineffective. Recurrence always occurs and leads to patient death. Prior studies have shown that dispersal of Glioblastoma can be significantly reduced by Dexamethasone (Dex, a drug currently used to control brain tumor related edema. However, due to high doses and significant side effects, treatment is tapered and discontinued as soon as edema has resolved. Prior analyses of the dispersal inhibitory effects of Dex were performed on tissue culture plastic, or polystyrene filters seeded with normal human astrocytes, conditions which inherently differ from the parenchymal architecture of neuronal tissue. The aim of this study was to utilize an ex-vivo model to examine Dex-mediated inhibition of tumor cell migration from low-passage, human Glioblastoma neurospheres on multiple substrates including mouse retina, and slices of mouse, pig, and human brain. We also determined the lowest possible Dex dose that can inhibit dispersal. Analysis by Two-Factor ANOVA shows that for GBM-2 and GBM-3, Dex treatment significantly reduces dispersal on all tissue types. However, the magnitude of the effect appears to be tissue-type specific. Moreover, there does not appear to be a difference in Dex-mediated inhibition of dispersal between mouse retina, mouse brain and human brain. To estimate the lowest possible dose at which Dex can inhibit dispersal, LogEC50 values were compared by Extra Sum-of-Squares F-test. We show that it is possible to achieve 50% reduction in dispersal with Dex doses ranging from 3.8 x10-8M to 8.0x10-9M for GBM-2, and 4.3x10-8M to 1.8x10-9M for GBM-3, on mouse retina and brain slices, respectively. These doses are 3-30-fold lower than those used to control edema. This study extends our previous in vitro data and identifies the mouse retina as a potential substrate for in vivo studies of GBM dispersal.

  2. Effects of thyroxine and dexamethasone on rat submandibular glands

    International Nuclear Information System (INIS)

    Sagulin, G.B.; Roomans, G.M.

    1989-01-01

    Glucocorticoids and thyroxine are known to have a marked effect on the flow rate and protein composition of rat parotid saliva in hormonally intact animals. In the present study, the effects of a one-week treatment of male rats with dexamethasone and thyroxine were studied by electron microscopy and x-ray micro-analysis, and by measurement of the flow rate and determination of the chemical composition of pilocarpine-induced submandibular saliva. Thyroxine had the most extensive effects on the submandibular gland. The acinar cells were enlarged and filled with mucus; the cellular calcium concentration was significantly increased. The flow rate of the submandibular saliva was significantly reduced compared with that in saline-injected control animals. Thyroxine caused an increase in the concentrations of protein, total calcium, and potassium in the saliva. Dexamethasone had no significant effects on gland ultrastructure or on the elemental composition of the acinar cells; flow rate was not affected, but the concentrations of protein, calcium, and potassium were significantly increased. The effects of dexamethasone and thyroxine on the flow rate and protein composition of pilocarpine-induced rat submandibular saliva differ from those reported earlier for rat parotid saliva after simultaneous stimulation with pilocarpine and isoproterenol

  3. Epigenomic Adaptation to Low Dose Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gould, Michael N. [Univ. of Wisconsin, Madison, WI (United States)

    2015-06-30

    The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted to live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’

  4. Investigation of the dose rate dependency of the PAGAT gel dosimeter at low dose rates

    International Nuclear Information System (INIS)

    Zehtabian, M.; Faghihi, R.; Zahmatkesh, M.H.; Meigooni, A.S.; Mosleh-Shirazi, M.A.; Mehdizadeh, S.; Sina, S.; Bagheri, S.

    2012-01-01

    Medical physicists need dosimeters such as gel dosimeters capable of determining three-dimensional dose distributions with high spatial resolution. To date, in combination with magnetic resonance imaging (MRI), polyacrylamide gel (PAG) polymers are the most promising gel dosimetry systems. The purpose of this work was to investigate the dose rate dependency of the PAGAT gel dosimeter at low dose rates. The gel dosimeter was used for measurement of the dose distribution around a Cs-137 source from a brachytherapy LDR source to have a range of dose rates from 0.97 Gy h −1 to 0.06 Gy h −1 . After irradiation of the PAGAT gel, it was observed that the dose measured by gel dosimetry was almost the same at different distances (different dose rates) from the source, although the points nearer the source had been expected to receive greater doses. Therefore, it was suspected that the PAGAT gel is dose rate dependent at low dose rates. To test this further, three other sets of measurements were performed by placing vials containing gel at different distances from a Cs-137 source. In the first two measurements, several plastic vials were exposed to equal doses at different dose rates. An ionization chamber was used to measure the dose rate at each distance. In addition, three TLD chips were simultaneously irradiated in order to verify the dose to each vial. In the third measurement, to test the oxygen diffusion through plastic vials, the experiment was repeated again using plastic vials in a nitrogen box and glass vials. The study indicates that oxygen diffusion through plastic vials for dose rates lower than 2 Gy h −1 would affect the gel dosimeter response and it is suggested that the plastic vials or (phantoms) in an oxygen free environment or glass vials should be used for the dosimetry of low dose rate sources using PAGAT gel to avoid oxygen diffusion through the vials.

  5. Protection against dexamethasone-induced muscle atrophy is related to modulation by testosterone of FOXO1 and PGC-1{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Weiping, E-mail: weiping.qin@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Department of Medicine, Mount Sinai School of Medicine, NY (United States); Pan, Jiangping; Wu, Yong [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Bauman, William A. [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Department of Medicine, Mount Sinai School of Medicine, NY (United States); Department of Rehabilitation Medicine, Mount Sinai School of Medicine, NY (United States); Cardozo, Christopher, E-mail: Chris.Cardozo@mssm.edu [Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center, Bronx, NY (United States); Department of Medicine, Mount Sinai School of Medicine, NY (United States); Department of Rehabilitation Medicine, Mount Sinai School of Medicine, NY (United States)

    2010-12-17

    Research highlights: {yields} In rat gastrocnemius muscle, dexamethasone reduced PGC-1{alpha} cellular and nuclear levels without altering mRNA levels for this factor. {yields} Dexamethasone reduced phosphorylating of p38 MAPK, which stabilizes PGC-1{alpha} and promotes its nuclear entry. {yields} Co-administration of testosterone with dexamethasone increased cellular and nuclear levels of PGC-1{alpha} protein without changing its mRNA levels. {yields} Co-administration of testosterone restored p38 MAPK levels to those of controls. -- Abstract: Glucocorticoid-induced muscle atrophy results from muscle protein catabolism and reduced protein synthesis, associated with increased expression of two muscle-specific ubiquitin ligases (MAFbx and MuRF1), and of two inhibitors of protein synthesis, REDD1 and 4EBP1. MAFbx, MuRF1, REDD1 and 4EBP1 are up-regulated by the transcription factors FOXO1 and FOXO3A. The transcriptional co-activator PGC-1{alpha} has been shown to attenuate many forms of muscle atrophy and to repress FOXO3A-mediated transcription of atrophy-specific genes. Dexamethasone-induced muscle atrophy can be prevented by testosterone, which blocks up-regulation by dexamethasone of FOXO1. Here, an animal model of dexamethasone-induced muscle atrophy was used to further characterize effects of testosterone to abrogate adverse actions of dexamethasone on FOXO1 levels and nuclear localization, and to determine how these agents affect PGC-1{alpha}, and its upstream activators, p38 MAPK and AMPK. In rat gastrocnemius muscle, testosterone blunted the dexamethasone-mediated increase in levels of FOXO1 mRNA, and FOXO1 total and nuclear protein. Dexamethasone reduced total and nuclear PGC-1{alpha} protein levels in the gastrocnemius; co-administration of testosterone with dexamethasone increased total and nuclear PGC-1{alpha} levels above those present in untreated controls. Testosterone blocked dexamethasone-induced decreases in activity of p38 MAPK in the gastrocnemius

  6. Risk of cancer subsequent to low-dose radiation

    International Nuclear Information System (INIS)

    Warren, S.

    1980-01-01

    The author puts low dose irradiation risks in perspective using average background radiation doses for standards. He assailed irresponsible media coverage during the height of public interest in the Three-Mile Island Reactor incident

  7. Lipopolysaccharide-induced inhibition of transcription of tlr4 in vitro is reversed by dexamethasone and correlates with presence of conserved NFκB binding sites

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, Camila P., E-mail: mila_bonin@yahoo.com.br [Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-900 (Brazil); Baccarin, Raquel Y.A., E-mail: baccarin@usp.br [Department of Clinics, School of Veterinary Medicine, University of São Paulo, São Paulo 05508-900 (Brazil); Nostell, Katarina, E-mail: katarina.nostell@slu.se [Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, 750 07 Uppsala (Sweden); Nahum, Laila A., E-mail: laila@nahum.com.br [Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte 30190-002 (Brazil); Faculdade Infórium de Tecnologia, Belo Horizonte 30130-180 (Brazil); Fossum, Caroline, E-mail: caroline.fossum@bvf.slu.se [Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, BMC, Box 588, SE 751 23 Uppsala (Sweden); Camargo, Maristela M. de, E-mail: mmcamar@usp.br [Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-900 (Brazil)

    2013-03-08

    Highlights: ► Chimpanzees, horses and humans have regions of similarity on TLR4 and MD2 promoters. ► Rodents have few regions of similarity on TLR4 promoter when compared to primates. ► Conserved NFkB binding sites were found in the promoters of TLR4 and MD2. ► LPS-induced inhibition of TLR4 transcription is reversed by dexamethasone. ► LPS-induced transcription of MD2 is inhibited by dexamethasone. -- Abstract: Engagement of Toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) is a master trigger of the deleterious effects of septic shock. Horses and humans are considered the most sensitive species to septic shock, but the mechanisms explaining these phenomena remain elusive. Analysis of tlr4 promoters revealed high similarity among LPS-sensitive species (human, chimpanzee, and horse) and low similarity with LPS-resistant species (mouse and rat). Four conserved nuclear factor kappa B (NFκB) binding sites were found in the tlr4 promoter and two in the md2 promoter sequences that are likely to be targets for dexamethasone regulation. In vitro treatment of equine peripheral blood mononuclear cells (eqPBMC) with LPS decreased transcripts of tlr4 and increased transcription of md2 (myeloid differentiation factor 2) and cd14 (cluster of differentiation 14). Treatment with dexamethasone rescued transcription of tlr4 after LPS inhibition. LPS-induced transcription of md2 was inhibited in the presence of dexamethasone. Dexamethasone alone did not affect transcription of tlr4 and md2.

  8. Elotuzumab in combination with thalidomide and low-dose dexamethasone

    DEFF Research Database (Denmark)

    Mateos, Maria-Victoria; Granell, Miguel; Oriol, Albert

    2016-01-01

    Elotuzumab is an immunostimulatory, humanized immunoglobulin G1 monoclonal antibody that selectively targets and kills signalling lymphocytic activation molecule family member 7-expressing myeloma cells. We evaluated the safety and tolerability of elotuzumab 10 mg/kg combined with thalidomide 50-...

  9. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    Science.gov (United States)

    Britton, Jr; Charles, L [Alcoa, TN; Buckner, Mark A [Oak Ridge, TN; Hanson, Gregory R [Clinton, TN; Bryan, William L [Knoxville, TN

    2011-04-26

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  10. Comparative trial of two intravenous doses of granisetron (1 versus 3 mg) in the prevention of chemotherapy-induced acute emesis: a double-blind, randomized, non-inferiority trial.

    Science.gov (United States)

    Tsuji, Daiki; Kim, Yong-Il; Taku, Keisei; Nakagaki, Shigeru; Ikematsu, Yoshito; Tsubota, Hiromi; Maeda, Masato; Hashimoto, Naoya; Kimura, Masayuki; Daimon, Takashi

    2012-05-01

    A single 3 mg or 40 μg/kg intravenous dose of granisetron combined with dexamethasone is routinely used in several countries, although the antiemetic guidelines have recommended granisetron at the dose of 1 mg or 10 μg/kg. A randomized, multicenter trial was conducted to determine the optimal intravenous granisetron dose, 1 or 3 mg, in cancer patients receiving emetogenic chemotherapy. We enrolled 365 patients and randomly assigned them to receive intravenous granisetron 3 mg (3-mg group) or 1 mg (1-mg group), combined with dexamethasone at an adequate dose fixed as per the emetic risk category. The primary end point was the proportion of patients with a complete response during the first 24 h after chemotherapy. The study demonstrated that 1 mg of granisetron was not inferior in effect to 3 mg. For the primary end point, 359 patients were evaluable according to the modified intention-to-treat (ITT) analysis. Complete protection was achieved in the modified ITT population, 90.6% and 88.8% for the 3- and 1-mg groups, respectively (p granisetron is not inferior to 3 mg when both doses are combined with dexamethasone. Therefore, 1-mg dose of intravenous granisetron should be the recommended prophylactic regimen for the prevention of acute emesis.

  11. Comparison of the effects of intravitreal bevacizumab and dexamethasone in experimental posterior penetrating eye injury

    Directory of Open Access Journals (Sweden)

    Ayse Oner

    2018-04-01

    Full Text Available AIM: To compare the effects of intravitreal anti-vascular endothelial growth factor (VEGF and dexamethasone in an experimental rabbit model of posterior penetrating ocular injury. METHODS: Thirty white New Zealand rabbits were included in the study. A posterior penetrating ocular injury was performed at the superotemporal quadrant. They were randomly divided into three groups. The rabbits in group 1 received intravitreal dexamethasone, in group 2 they received intravitreal bevacizumab and those in group 3 received intravitreal physiological saline solution in both eyes. All eyes were examined ophthalmologically on the 1st, 3rd, 7th, 14th and 28th days following the injury and the clinical findings were scored. On the day 28, the eyes were enucleated, evaluated and scored macroscopically, histopathologically and scanning electron microscopically. RESULTS: The median clinical score on the 14th and 28th days and the median macroscopic score of the dexamethasone group was significantly better than that of control (P=0.004, 0.018. Dexamethasone group was also better than that of bevacizumab group but the differences did not reach statistical significance. Retinal detachment rate was 8.3%, 16.6% and 12.5% in the dexamethasone group, bevacizumab group and control group, respectively (P=0.476. More extensive fibrocelluler proliferations were observed in controls compared with dexamethasone and bevacizumab groups. But these differences did not reach the statistical significance (P=0.538. In scanning electron microscopy all groups showed fibreous stalk and dense collagen fibrils in vitreous. CONCLUSION: This study shows that intravitreal injection of both dexamethasone and bevacizumab may reduce the intraocular fibrous proliferation after an experimental posterior penetrating ocular injury in rabbits.

  12. Salvage bortezomib-dexamethasone and high-dose melphalan (HDM) and autologous stem cell support (ASCT) in myeloma patients at first relapse after HDM with ASCT. A phase-2 trial

    DEFF Research Database (Denmark)

    Gimsing, P; Hjertner, Ø; Abildgaard, N

    2015-01-01

    , there was no significant difference of PFS and TNT after HDM (II) compared with after the initial HDM(I), and thus patients were their own controls (PFS (I: 20.1 vs II: 19.3 months (P=0.8)) or TNT (I: 24.4 vs II: 20.7 months (P=0.8)). No significant differences in the response rates after salvage ASCT compared......Until recently, only retrospective studies had been published on salvage high-dose melphalan (HDM) with autologous stem cell 'transplantation' (ASCT). In a prospective, nonrandomized phase-2 study, we treated 53 bortezomib-naïve patients with bortezomib-dexamethasone as induction and bortezomib...... included in the conditioning regimen along with the HDM. Median progression-free survival (PFS), time to next treatment (TNT) and overall survival (OS) after start of reinduction therapy were 21.6, 22.8 and 46.6 months, respectively. For 49 patients who completed salvage bortezomib-HDM(II) with ASCT...

  13. Energies, health, medicine. Low radiation doses

    International Nuclear Information System (INIS)

    2004-01-01

    This file concerns the biological radiation effects with a special mention for low radiation doses. The situation of knowledge in this area and the mechanisms of carcinogenesis are detailed, the different directions of researches are given. The radiation doses coming from medical examinations are given and compared with natural radioactivity. It constitutes a state of the situation on ionizing radiations, known effects, levels, natural radioactivity and the case of radon, medicine with diagnosis and radiotherapy. (N.C.)

  14. Effects of dexamethasone and pheniramine hydrogen maleate on stress response in patients undergoing elective laparoscopic cholecystectomy.

    Science.gov (United States)

    Karaman, Kerem; Bostanci, Erdal Birol; Aksoy, Erol; Ulas, Murat; Yigit, Tuba; Erdemli, Mehmet Ozcan; Ercin, Ugur; Bilgihan, Ayse; Saydam, Gul; Akoglu, Musa

    2013-02-01

    Laparoscopic cholecystectomy (LC) still leads to significant postoperative nausea and vomiting (PONV) and pain. Our aim was to evaluate the efficacy of dexamethasone or pheniramine hydrogen maleate, either alone or combined, in reducing the stress response and symptoms after LC. Patients were randomly assigned to 1 of 4 groups, each consisting of 20 patients: control, dexamethasone (8 mg/2 mL), pheniramine hydrogen maleate (45.5 mg/2 mL), and the combined group. The drugs were given before anesthesia induction. C-reactive protein levels (CRP) and visual analog scale (VAS) scores were significantly less in the dexamethasone (P = .003) and combined groups (P pheniramine hydrogen maleate (P = .005) significantly reduced PONV. Dexamethasone significantly reduced postoperative pain and the systemic acute-phase response, whereas these effects were only partially attained with pheniramine hydrogen maleate. Both dexamethasone and pheniramine hydrogen maleate significantly reduced PONV. An additive effect seemed to occur if these drugs were used in combination. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Dexamethasone-(C21-phosphoramide-[anti-EGFR]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency against pulmonary adenocarcinoma (A549

    Directory of Open Access Journals (Sweden)

    Coyne CP

    2016-08-01

    Full Text Available Cody P Coyne,1 Lakshmi Narayanan2 1Department of Basic Sciences, 2Department of Clinical Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, MS, USA Purpose: Corticosteroids are effective in the management of a variety of disease states, such as several forms of neoplasia (leukemia and lymphoma, autoimmune conditions, and severe inflammatory responses. Molecular strategies that selectively “target” delivery of corticosteroids minimize or prevents large amounts of the pharmaceutical moiety from passively diffusing into normal healthy cell populations residing within tissues and organ systems. Materials and methods: The covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide-[anti-EGFR] was synthesized by reacting dexamethasone-21-monophosphate with a carbodiimide reagent to form a dexamethasone phosphate carbodiimide ester that was subsequently reacted with imidazole to create an amine-reactive dexamethasone-(C21-phosphorylimidazolide intermediate. Monoclonal anti-EGFR immunoglobulin was combined with the amine-reactive dexamethasone-(C21-phosphorylimidazolide intermediate, resulting in the synthesis of the covalent immunopharmaceutical, dexamethasone-(C21-phosphoramide-[anti-EGFR]. Following spectrophotometric analysis and validation of retained epidermal growth factor receptor type 1 (EGFR-binding avidity by cell-ELISA, the selective anti-neoplasic cytotoxic potency of dexamethasone-(C21-phosphoramide-[anti-EGFR] was established by MTT-based vitality stain methodology using adherent monolayer populations of human pulmonary adenocarcinoma (A549 known to overexpress the tropic membrane receptors EGFR and insulin-like growth factor receptor type 1. Results: The dexamethasone:IgG molar-incorporation-index for dexamethasone-(C21-phosphoramide-[anti-EGFR] was 6.95:1 following exhaustive serial microfiltration. Cytotoxicity analysis: covalent bonding of dexamethasone to monoclonal anti-EGFR immunoglobulin

  16. Accuracy of low dose CT in the diagnosis of appendicitis in childhood and comparison with USG and standard dose CT.

    Science.gov (United States)

    Yi, Dae Yong; Lee, Kyung Hoon; Park, Sung Bin; Kim, Jee Taek; Lee, Na Mi; Kim, Hyery; Yun, Sin Weon; Chae, Soo Ahn; Lim, In Seok

    Computed tomography should be performed after careful consideration due to radiation hazard, which is why interest in low dose CT has increased recently in acute appendicitis. Previous studies have been performed in adult and adolescents populations, but no studies have reported on the efficacy of using low-dose CT in children younger than 10 years. Patients (n=475) younger than 10 years who were examined for acute appendicitis were recruited. Subjects were divided into three groups according to the examinations performed: low-dose CT, ultrasonography, and standard-dose CT. Subjects were categorized according to age and body mass index (BMI). Low-dose CT was a contributive tool in diagnosing appendicitis, and it was an adequate method, when compared with ultrasonography and standard-dose CT in terms of sensitivity (95.5% vs. 95.0% and 94.5%, p=0.794), specificity (94.9% vs. 80.0% and 98.8%, p=0.024), positive-predictive value (96.4% vs. 92.7% and 97.2%, p=0.019), and negative-predictive value (93.7% vs. 85.7% and 91.3%, p=0.890). Low-dose CT accurately diagnosed patients with a perforated appendix. Acute appendicitis was effectively diagnosed using low-dose CT in both early and middle childhood. BMI did not influence the accuracy of detecting acute appendicitis on low-dose CT. Low-dose CT is effective and accurate for diagnosing acute appendicitis in childhood, as well as in adolescents and young adults. Additionally, low-dose CT was relatively accurate, irrespective of age or BMI, for detecting acute appendicitis. Therefore, low-dose CT is recommended for assessing children with suspected acute appendicitis. Copyright © 2017. Published by Elsevier Editora Ltda.

  17. Comparison of low dose with standard dose abdominal/pelvic multidetector CT in patients with stage 1 testicular cancer under surveillance

    Energy Technology Data Exchange (ETDEWEB)

    O' Malley, Martin E. [Joint Department of Medical Imaging, Toronto, ON (Canada); Chung, Peter; Warde, Padraig [Princess Margaret Hospital, Department of Radiation Oncology, Toronto, ON (Canada); Haider, Masoom; Jhaveri, Kartik; Khalili, Korosh [Princess Margaret Hospital, Joint Department of Medical Imaging, Toronto, ON (Canada); Jang, Hyun-Jung [Toronto General Hospital, Joint Department of Medical Imaging, Toronto, ON (Canada); Panzarella, Tony [Princess Margaret Hospital, Department of Biostatistics, Toronto, ON (Canada)

    2010-07-15

    To compare the image quality and acceptability of a low dose with those of standard dose abdominal/pelvic multidetector CT in patients with stage 1 testicular cancer managed by surveillance. One hundred patients (median age 31 years; range 19-83 years), 79 with seminoma and 21 with non-seminoma, underwent abdominal/pelvic imaging with low and standard dose protocols on 64-slice multidetector CT. Three reviewers independently evaluated images for noise and diagnostic quality on a 5-point scale and for diagnostic acceptability. On average, each reader scored noise and diagnostic quality of standard dose images significantly better than corresponding low dose images (p < 0.0001). One reader found all CT examinations acceptable; two readers each found 1/100 (1%) low dose examinations unacceptable. Median and mean dose-length product for low and standard dose protocols were 416.0 and 452.2 (range 122.9-913.4) and 931.9 and 999.8 (range 283.8-1,987.7) mGy cm, respectively. The low dose protocol provided diagnostically acceptable images for at least 99% of patients and achieved mean dose reduction of 55% compared with the standard dose protocol. (orig.)

  18. Effect of low-dose radiation on ocular circulation

    International Nuclear Information System (INIS)

    Baba, Keiko; Hiroishi, Goro; Honda, Masae; Yoshikawa, Hiroshi; Fujisawa, Kimihiko; Ishibashi, Tatsuro

    1999-01-01

    We treated 6 eyes of unilateral age-related macular degeneration by low-dose radiation. Each eye received daily dose of 2 Gy by 4MV lineac totalling 20 Gy over 2 weeks. Color doppler flowmetry was used to determine the mean blood flow velocity (Vmean) and vascular resistive index (RI) in the short posterior ciliary artery, central retinal artery and ophthalmic artery in the treated and fellow eyes before and up to 6 months of treatment. There were no significant differences in Vmean and RI before and after treatment. The findings show the absence of apparent influence of low-dose radiation on the ocular circulation in age-related macular degeneration. (author)

  19. Effect of low-dose radiation on ocular circulation

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Keiko; Hiroishi, Goro; Honda, Masae; Yoshikawa, Hiroshi; Fujisawa, Kimihiko; Ishibashi, Tatsuro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1999-05-01

    We treated 6 eyes of unilateral age-related macular degeneration by low-dose radiation. Each eye received daily dose of 2 Gy by 4MV lineac totalling 20 Gy over 2 weeks. Color doppler flowmetry was used to determine the mean blood flow velocity (Vmean) and vascular resistive index (RI) in the short posterior ciliary artery, central retinal artery and ophthalmic artery in the treated and fellow eyes before and up to 6 months of treatment. There were no significant differences in Vmean and RI before and after treatment. The findings show the absence of apparent influence of low-dose radiation on the ocular circulation in age-related macular degeneration. (author)

  20. Synthesis of dexamethasone-4-14C

    International Nuclear Information System (INIS)

    Rao, P.N.; Cessac, J.W.; Hill, K.A.

    1982-01-01

    The bismethylenedioxy (BMD) derivative of dexamethasone 2 was silylated with trimethylchlorosilane and imidazole in dimethylformamide to give the 11β-trimethylsilyloxy BMD derivative 3. The Δ 1 -double bond in 3 was hydrogenated over 5% palladium on carbon to give the Δ 4 -3-oxo steroid 4. Oxidation of 4 with potassium permanganate-sodium metaperiodate gave the seco-acid 5 which on subsequent treatment with acetic anhydride; sodium acetate and triethylamine gave the enol-lactone 6. The enol-lactone 6 was reacted with 14 C-methylmagnesium iodide to give an adduct 7a which on heating at reflux with lithium 2,6-di-t-butylphenoxide in dioxane gave the Δ 4 -3-oxo derivative 8. Compound 8 was heated at reflux with m-iodylbenzoic acid and diphenyl diselenide in toluene to give the Δsup(1,4)-3-oxo steroid 9. The protecting BMD and silyl groups were removed in a single step by reaction with aqueous trifluoroacetic acid containing 2N hydrochloric acid at room temperature to give dexamethasone-4- 14 C 10. (author)

  1. Compatibility and stability of aloxi (palonosetron hydrochloride) admixed with dexamethasone sodium phosphate.

    Science.gov (United States)

    Trissel, Lawrence A; Zhang, Yanping

    2004-01-01

    The purpose of this study was to evaluate the physical and chemical stability of palonosetron hydrochloride 0.25 mg admixed with dexamethasone (as sodium phophate) 10 mg or 20 mg in 5% dextrose injection or 0.9% sodium chloride injection in polyvinylchloride minibags, and also admixed with dexamethasone (as sodium phosphate) 3.3 mg in 5% dextrose injection or 0.9% sodium chloride injection in polypropylene syringes, at 4 deg C stored in the dark for 14 days, and at 23 deg C exposed to normal laboratory fluorescent light over 48 hours. Test samples of palonosetron hydrochloride 5 micrograms/mL with dexamethasone (as sodium phosphate) 0.2 mg/mL and also 0.4 mg/mL were prepared in polyvinylchloride minibags of each infusion solution. Additionally, palonosetron hydrochloride 25 micrograms/mL with dexamethasone (as sodium phosphate) 0.33 mg/mL in each infusion solution were prepared as 10 mL of test solution in 20-mL polypropylene syringes. Evaluations for physical and chemical stability were performed on samples taken initially and after 1, 3, 7 and 14 days of storage at 4 deg C and after 1, 4, 24 and 48 hours at 23 deg C. Physical stability was assessed using visual observation in normal room light and using a high-intensity monodirectional light beam. In addition, turbidity and particle content were measured electronically. Chemical stability of the drug was evaluated by using a stability-indicating high-performance liquid chromatographic analytical technique. All samples were physically compatible throughout the study. The solutions remained clear and showed little or no change in particulate burden and haze level. Additionally, little or no loss of palonosetron hydrochloride and dexamethasone occurred in any of the samples at either temperature throughout the entire study period. Admixtures of palonosetron hydrochloride with dexamethasone sodium phosphate in 5% dextrose injection or in 0.9% sodium chloride injection packaged in polyvinylchloride minibags or in

  2. Low dose effects detected by micronucleus assay in lymphocytes

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Bojtor, I.; Kubasova, T.; Horvath, G.

    1997-01-01

    The effects of low doses of X-rays between 0.01 and 1 Gy were studied on whole blood samples of various individuals using the cytokinesis-blocked lymphocyte micronucleus assay as an endpoint. The adaptive response could be induced in G 0 cells by 0.01 Gy followed by 1 Gy challenging dose within a time period of 8 hours, in vitro. The probability distribution of micronucleus increments in those samples which had received very low doses in the range 0.01-0.05 Gy proved to be of asymmetrical type (i.e. lognormal) -very likely to the same shape which has been verified for unirradiated (control) population - while the variable turned to be normally distributed at or above 1 Gy. Profound changes have been experienced in the main characteristics of the linear dose - response relationship and in regression parameters, as well, when successively lessened dose ranges were studied toward 0.01 Gy. In the range below ∼ 0.2 Gy the response were found to be unrelated to the absorbed dose. These findings suggest that in (very) low dose range a higher attention should be needed to biological parameters like repair, protective mechanisms and antioxidant capacities, rather than to the absorbed radiation energy only. (author)

  3. Laparoscopic cholecystectomy under spinal anesthesia: comparative study between conventional-dose and low-dose hyperbaric bupivacaine

    Directory of Open Access Journals (Sweden)

    Imbelloni LE

    2011-10-01

    Full Text Available Luiz Eduardo Imbelloni1, Raphael Sant'Anna2, Marcos Fornasari2, José Carlos Fialho21Department of Anesthesiology, Faculty of Medecine Nova Esperança, Hospital de Mangabeira, João Pessoa, 2Hospital Rio Laranjeiras, Rio de Janeiro, BrazilBackground: Laparoscopic cholecystectomy has the advantages of causing less postoperative pain and requiring a short hospital stay, and therefore is the treatment of choice for cholelithiasis. This study was designed to compare spinal anesthesia using hyperbaric bupivacaine given as a conventional dose by lumbar puncture or as a low-dose by thoracic puncture.Methods: A total of 140 patients with symptomatic gallstone disease were randomized to undergo laparoscopic cholecystectomy with low-pressure CO2 pneumoperitoneum under spinal anesthesia using either conventional lumbar spinal anesthesia (hyperbaric bupivacaine 15 mg and fentanyl 20 mg or low-dose thoracic spinal anesthesia (hyperbaric bupivacaine 7.5 mg and fentanyl 20 µg. Intraoperative parameters, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two treatment groups.Results: All procedures were completed under spinal anesthesia, with no cases needing conversion to general anesthesia. Values for time for block to reach the T3 dermatomal level, duration of motor and sensory block, and hypotensive events were significantly lower with low-dose bupivacaine. Postoperative pain was higher for low-dose hyperbaric bupivacaine at 6 and 12 hours. All patients were discharged after 24 hours. Follow-up 1 week postoperatively showed all patients to be satisfied and to be keen advocates of spinal anesthesia.Conclusion: Laparoscopic cholecystectomy can be performed successfully under spinal anesthesia. A small dose of hyperbaric bupivacaine 7.5 mg and 20 µg fentanyl provides adequate spinal anesthesia for laparoscopy and, in comparison with hyperbaric bupivacaine 15% and fentanyl 20 µg, causes markedly

  4. Dose-rate effects of low-dropout voltage regulator at various biases

    International Nuclear Information System (INIS)

    Wang Yiyuan; Zheng Yuzhan; Gao Bo; Chen Rui; Fei Wuxiong; Lu Wu; Ren Diyuan

    2010-01-01

    A low-dropout voltage regulator, LM2941, was irradiated by 60 Co γ-rays at various dose rates and biases for investigating the total dose and dose rate effects. The radiation responses show that the key electrical parameters, including its output and dropout voltage, and the maximum output current, are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias. The integrated circuits damage change with the dose rates and biases, and the dose-rate effects are relative to its electric field. (authors)

  5. CARCINOGENIC EFFECTS OF LOW DOSES OF IONIZING RADIATION

    Science.gov (United States)

    Carcinogenic Effects of Low Doses of Ionizing RadiationR Julian Preston, Environmental Carcinogenesis Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711The form of the dose-response curve for radiation-induced cancers, particu...

  6. [Effects of extremely low frequency electromagnetic radiation on cardiovascular system of workers].

    Science.gov (United States)

    Zhao, Long-yu; Song, Chun-xiao; Yu, Duo; Liu, Xiao-liang; Guo, Jian-qiu; Wang, Chuan; Ding, Yuan-wei; Zhou, Hong-xia; Ma, Shu-mei; Liu, Xiao-dong; Liu, Xin

    2012-03-01

    To observe the exposure levels of extremely low frequency electromagnetic fields in workplaces and to analyze the effects of extremely low frequency electromagnetic radiation on cardiovascular system of occupationally exposed people. Intensity of electromagnetic fields in two workplaces (control and exposure groups) was detected with EFA-300 frequency electromagnetic field strength tester, and intensity of the noise was detected with AWA5610D integral sound level. The information of health physical indicators of 188 controls and 642 occupationally exposed workers was collected. Data were analyzed by SPSS17.0 statistic software. The intensity of electric fields and the magnetic fields in exposure groups was significantly higher than that in control group (P 0.05). The results of physical examination showed that the abnormal rates of HCY, ALT, AST, GGT, ECG in the exposure group were significantly higher than those in control group (P 0.05). Exposure to extremely low frequency electromagnetic radiation may have some effects on the cardiovascular system of workers.

  7. Ultra-low dose of intravitreal bevacizumab in retinopathy of prematurity.

    Science.gov (United States)

    Şahin, A; Gürsel-Özkurt, Z; Şahin, M; Türkcü, F M; Yıldırım, A; Yüksel, H

    2018-05-01

    We aimed to investigate the effectivity of the 0.0625 mg dose of bevacizumab in patients with retinopathy of prematurity (ROP) and compare the results with 0.625 mg dose of intravitreal bevacizumab (IVB) injection. The medical records of the patients with type 1 ROP who received IVB monotherapy were retrospectively reviewed. Demographic and clinical characteristics of the patients were recorded. The patients were classified into two groups with respect to received dose of bevacizumab as follows: group F (n = 46) (full dose of bevacizumab-0.625 mg/0.025 ml) and group L (n = 45) (low dose (one tenth) of bevacizumab-0.0625 mg/0.025 ml). Both treatment dose regimens have similar outcomes. Moreover, the mean retinal vascularization time seemed to be significantly higher in group F compared to group L, 168 ± 65 and 97 ± 29 days, respectively (p < 0.001). Disappearance of plus sign is observed earlier in group F (2.45 ± 1.7 vs 3.66 ± 2.46 days, respectively, p = 0.03). The low dose (0.0625 mg) of IVB treatment was effective as full (0.625 mg) dose in ROP treatment. Moreover, our results showed that low-dose treatment might provide faster retinal vascularization than the regular used dose. On the other hand, disappearance of the plus sign takes longer time in patients treated with low dose compared to eyes treated with full dose of IVB that should be taken into account.

  8. Variable effects of dexamethasone on protein synthesis in clonal rat osteosarcoma cells

    International Nuclear Information System (INIS)

    Hodge, B.O.; Kream, B.E.

    1988-01-01

    We examined the effects of dexamethasone on protein synthesis in clonal rat osteoblastic osteosarcoma (ROS) cell lines by measuring the incorporation of [ 3 H]proline into collagenase-digestible and noncollagen protein in the cell layer and medium of the cultures. In ROS 17/2 and subclone C12 of ROS 17/2.8, dexamethasone decreased collagen synthesis with no change in DNA content of the cultures. In ROS 17/2.8 and its subclone G2, dexamethasone stimulated collagen and noncollagen protein synthesis, with a concomitant decrease in the DNA content of the cells. These data indicate that ROS cell lines are phenotypically heterogeneous and suggest that in normal bone there may be distinct subpopulations of osteoblasts with varying phenotypic traits with respect to the regulation of protein synthesis

  9. A study of the dose distribution in the region of the eye lens and extremities for staff working in interventional cardiology

    International Nuclear Information System (INIS)

    Domienik, J.; Brodecki, M.; Rusicka, D.

    2012-01-01

    The dose distributions at the region of eye lens and extremities of staff working in interventional cardiology were analyzed. The doses to physicians and nurses from three hospitals in Poland were measured with TL dosimeters (MCP-N) located on various places near eyebrows, on both fingers, wrists, knees and on the ankle. The procedures under investigation were coronary angiography (CA) and percutaneous coronary intervention (PCI), peacemaker and defibrillator implantations (PM/ICDs), cardiac resynchronization therapy with or without defibrillator implantations (CRT-D or CRT) and radiofrequency ablations (RFA). The study aimed at analyzing the distribution of radiation in selected anatomic regions, determining the typical locations of highest doses and estimating the dose ranges for selected types of procedures. The maximum registered doses per procedure to eye lens and ankle were 1.21 mSv and 1.46 mSv for CA PCI procedures, 0.02 mSv and 0.05 mSv for RFA and 0.13 mSv and 0.51 mSv for PM/ICDs, respectively. The maximum doses to fingers, wrists and knees were, accordingly, 2.11 mSv, 1.07 mSv and 0.77 mSv for CA PCI procedures, 0.38 mSv, 0.20 mSv and 0.04 mSv for RFA ones, 0.50 mSv, 0.25 mSv and 0.01 mSv for PM/ICDs procedures and 2.25 mSv, 1.12 mSv and 0.58 mSv for CRT and CRT-D ones. The factors which might influence the dose like utilized radiation, availability of additional protective equipment and position of the staff with respect to X-ray source were also analyzed. The annual doses for eye lens and extremities were estimated on the basis of individual annual workloads of the physicians participating in the study. The highest annual doses were revealed for physicians performing CA PCI procedures. Annual eye lens doses range up to 247 mSv indicating that the occupational limit for eye lens 150 mSv has been surpassed. In case of extremities the maximal estimated annual doses were 355 mSv, 136 mSv, 55 mSv and 328 mSv, for fingers, wrists, knees and for ankle

  10. Harderian Gland Tumorigenesis: Low-Dose and LET Response

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Polly Y. [SRI International, Menlo Park, CA (United States). Biosciences Div.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Cucinotta, Francis A. [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Health Physics and Diagnostic Sciences; Bjornstad, Kathleen A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Bakke, James [SRI International, Menlo Park, CA (United States). Biosciences Div.; Rosen, Chris J. [SRI International, Menlo Park, CA (United States). Biosciences Div.; Du, Nicholas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Fairchild, David G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Cacao, Eliedonna [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Health Physics and Diagnostic Sciences; Blakely, Eleanor A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.

    2016-04-19

    Increased cancer risk remains a primary concern for travel into deep space and may preclude manned missions to Mars due to large uncertainties that currently exist in estimating cancer risk from the spectrum of radiations found in space with the very limited available human epidemiological radiation-induced cancer data. Existing data on human risk of cancer from X-ray and gamma-ray exposure must be scaled to the many types and fluences of radiations found in space using radiation quality factors and dose-rate modification factors, and assuming linearity of response since the shapes of the dose responses at low doses below 100 mSv are unknown. The goal of this work was to reduce uncertainties in the relative biological effect (RBE) and linear energy transfer (LET) relationship for space-relevant doses of charged-particle radiation-induced carcinogenesis. The historical data from the studies of Fry et al. and Alpen et al. for Harderian gland (HG) tumors in the female CB6F1 strain of mouse represent the most complete set of experimental observations, including dose dependence, available on a specific radiation-induced tumor in an experimental animal using heavy ion beams that are found in the cosmic radiation spectrum. However, these data lack complete information on low-dose responses below 0.1 Gy, and for chronic low-dose-rate exposures, and there are gaps in the LET region between 25 and 190 keV/μm. In this study, we used the historical HG tumorigenesis data as reference, and obtained HG tumor data for 260 MeV/u silicon (LET ~70 keV/μm) and 1,000 MeV/u titanium (LET ~100 keV/μm) to fill existing gaps of data in this LET range to improve our understanding of the dose-response curve at low doses, to test for deviations from linearity and to provide RBE estimates. Animals were also exposed to five daily fractions of 0.026 or 0.052 Gy of 1,000 MeV/u titanium ions to simulate chronic exposure, and HG tumorigenesis from this fractionated study were compared to the

  11. Low dose monitoring by double implant technique in IC fabrication

    International Nuclear Information System (INIS)

    Ahmad, I.B.; Weidemann, J.

    1995-01-01

    The utilisation of low dose implant monitoring (using Boron) in a manufacturing line has been discussed. The utilisation of phosphorus ions as the second implant dose were also studied as comparison. The technique relies on the fact that the sheet resistant of doped layer will increase significantly when damaged by relatively low implant dose. The technique is very sensitive and applicable for adjusting the channel dose so that an accurate threshold voltage in MOS device could be achieved

  12. A Comparative Study on the Efficacy of Submucosal Injection of Dexamethasone Versus Methylprednisolone in Reducing Postoperative Sequelae After Third Molar Surgery.

    Science.gov (United States)

    Lim, Daniel; Ngeow, Wei Cheong

    2017-11-01

    To compare the efficacy of preoperative submucosal injection of 4 mg of dexamethasone versus 40 mg of methylprednisolone in reducing postoperative sequelae after surgical removal of impacted mandibular third molars. This prospective, randomized, double-blind study included 65 patients who required surgical removal of impacted mandibular third molars with Class II or position B impaction (Pell and Gregory classification). Patients were randomly assigned to 1 of 3 groups: dexamethasone, methylprednisolone, or placebo (control). Surgery was performed with patients under local anesthesia. Baseline measurements were obtained preoperatively, and subsequent assessments were made on postoperative day 1, 2, 5, and 7 to measure postoperative facial swelling by use of 2 linear measurements: interincisal mouth opening width and visual analog scale score for pain. The amount of analgesics consumed was recorded. Wound healing also was assessed on postoperative day 7. Descriptive and multivariate statistics were computed, and significance was set at P Kruskal-Wallis test), whereas the methylprednisolone group had significantly less pain (P Kruskal-Wallis test) and consumed a lower amount of analgesics (P test) during the early postoperative days. The study findings suggest that a single preoperative dose of dexamethasone versus methylprednisolone was equally effective in reducing postoperative swelling and trismus. Pain control by these corticosteroids, however, was variable. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  13. New risk estimates at low doses

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1992-01-01

    The age of molecular radiation epidemiology may be at hand. The techniques are available to establish with the degree of precision required to determine whether agent-specific mutations can be identified consistently. A concerted effort to examine radiation-induced changes in as many relevant genes as possible appears to be justified. Cancers in those exposed to low doses of ionizing radiation should be chosen for the investigation. Parallel studies of radiation-induced cancers in experimental animals would not only complement the human studies, but perhaps reveal approaches to extrapolation of risk estimates across species. A caveat should be added to this optimistic view of what molecular studies might contribute to the knotty problem of risk estimates at low doses. The suggestions are made by one with no expertise in the field of molecular biology

  14. Hormesis of Low Doses of Ionizing Radiation Exposure on Immune System

    International Nuclear Information System (INIS)

    Ragab, M.H.; Abbas, M.O.; El-Asady, R.S.; Amer, H.A.; El-Khouly, W.A.; Shabon, M.H.

    2015-01-01

    The effect of low doses of ionizing radiation on the immune system has been a controversial subject. To evaluate the effect of low-doses γ-irradiation exposure on immune system. An animal model, using Rattus Rattus rats was used. The rats were divided into groups exposed to either continuous or fractionated 100, 200, 300, 400 and 500 mSv of radiation and compared to control rats that did not receive radiation. All groups were exposed to a total white blood count (Wcs), lymphocyte count and serum IgG level measurement, as indicators of the function of the cell-mediated (T lymphocytes) and the humoral (B lymphocytes) immune system. The results of the current study revealed that the counts of total leukocytes (WBCs) and lymphocytes, as well as the serum level of IgG were increased significantly in rats receiving low dose radiation, indicating enhancement of immune system. The data suggests that low-dose gamma-radiation improved hematological parameters and significantly enhances immune response indices of the exposed rats. These findings are similar to the radiation adaptive responses in which a small dose of pre irradiation would induce certain radiation resistance and enhances the cell response after exposure to further irradiation doses The applied low doses used in the present study may appear effective inducing the radio adaptive response. Farooqi and Kesavan (1993) and Bravard et al. (1999) reported that the adaptive response to ionizing radiation refers to the phenomenon by which cells irradiated with low (cGy) or sublethal doses (conditioning doses) become less susceptible to genotoxic effects of a subsequent high dose (challenge dose, several Gy).

  15. Risk of low-doses in radiodiagnosis; Risque des faibles doses en radiodiagnostic. Mythes, reglementation et rationalite

    Energy Technology Data Exchange (ETDEWEB)

    Cordoliani, Y.S.; Sarrazin, J.L.; Le Frian, G.; Soulie, D.; Leveque, C. [Hopital d`Instruction des Armees du Val-de-Grace, 75 - Paris (France)

    1997-12-31

    The effect of low doses of X-rays is inferred from the indubitable effects of high doses in human carcinogenesis, Genetic and teratogenic effects are mainly inferred from animal experimentation because clinical surveys of irradiated pregnant women have failed to demonstrate such consequences in the children, except for mental retardation after Japanese atomic bombing. Since no evidence of carcinogenic effect has been produced by epidemiological studies for doses lower than 500 mSv. the estimation of the risk due to low doses has been extrapolated from the linear relation between dose and cancers at high doses. Such an extrapolation gives a maximal risk which is falsely used as a probability of cancer. The actual risk lies between zero and this maximal number, and many epidemiologic surveys in people receiving doses much higher than the mean level of background irradiation failed to demonstrate higher rate of cancer. The explanation of this fact, which is supported by the most recent biological data, is the efficacy of the DNA repair system at low level of exposure to ionizing radiations. We expose the principles of regulation of radioprotection for workers, and give estimations of the doses delivered to the patients and the personnel by diagnostic investigations, by comparing these doses with those of natural irradiation. Practical aspect for conventional and computed radiology are exposed for patients and workers. (authors)

  16. Monte Carlo investigation of the low-dose envelope from scanned proton pencil beams

    International Nuclear Information System (INIS)

    Sawakuchi, Gabriel O; Titt, Uwe; Mirkovic, Dragan; Ciangaru, George; Zhu, X Ronald; Sahoo, Narayan; Gillin, Michael T; Mohan, Radhe

    2010-01-01

    Scanned proton pencil beams carry a low-dose envelope that extends several centimeters from the individual beam's central axis. Thus, the total delivered dose depends on the size of the target volume and the corresponding number and intensity of beams necessary to cover the target volume uniformly. This dependence must be considered in dose calculation algorithms used by treatment planning systems. In this work, we investigated the sources of particles contributing to the low-dose envelope using the Monte Carlo technique. We used a validated model of our institution's scanning beam line to determine the contributions to the low-dose envelope from secondary particles created in a water phantom and particles scattered in beam line components. Our results suggested that, for high-energy beams, secondary particles produced by nuclear interactions in the water phantom are the major contributors to the low-dose envelope. For low-energy beams, the low-dose envelope is dominated by particles undergoing multiple Coulomb scattering in the beam line components and water phantom. Clearly, in the latter situation, the low-dose envelope depends directly on beam line design features. Finally, we investigated the dosimetric consequences of the low-dose envelope. Our results showed that if not modeled properly the low-dose envelope may cause clinically relevant dose disturbance in the target volume. This work suggested that this low-dose envelope is beam line specific for low-energy beams, should be thoroughly experimentally characterized and validated during commissioning of the treatment planning system, and therefore is of great concern for accurate delivery of proton scanning beam doses.

  17. Exposure of luminous marine bacteria to low-dose gamma-radiation.

    Science.gov (United States)

    Kudryasheva, N S; Petrova, A S; Dementyev, D V; Bondar, A A

    2017-04-01

    The study addresses biological effects of low-dose gamma-radiation. Radioactive 137 Cs-containing particles were used as model sources of gamma-radiation. Luminous marine bacterium Photobacterium phosphoreum was used as a bioassay with the bioluminescent intensity as the physiological parameter tested. To investigate the sensitivity of the bacteria to the low-dose gamma-radiation exposure (≤250 mGy), the irradiation conditions were varied as follows: bioluminescence intensity was measured at 5, 10, and 20°С for 175, 100, and 47 h, respectively, at different dose rates (up to 4100 μGy/h). There was no noticeable effect of gamma-radiation at 5 and 10°С, while the 20°С exposure revealed authentic bioluminescence inhibition. The 20°С results of gamma-radiation exposure were compared to those for low-dose alpha- and beta-radiation exposures studied previously under comparable experimental conditions. In contrast to ionizing radiation of alpha and beta types, gamma-emission did not initiate bacterial bioluminescence activation (adaptive response). As with alpha- and beta-radiation, gamma-emission did not demonstrate monotonic dose-effect dependencies; the bioluminescence inhibition efficiency was found to be related to the exposure time, while no dose rate dependence was found. The sequence analysis of 16S ribosomal RNA gene did not reveal a mutagenic effect of low-dose gamma radiation. The exposure time that caused 50% bioluminescence inhibition was suggested as a test parameter for radiotoxicity evaluation under conditions of chronic low-dose gamma irradiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

    International Nuclear Information System (INIS)

    Tewari-Singh, Neera; Jain, Anil K.; Inturi, Swetha; Ammar, David A.; Agarwal, Chapla; Tyagi, Puneet; Kompella, Uday B.; Enzenauer, Robert W.; Petrash, J. Mark; Agarwal, Rajesh

    2012-01-01

    There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

  19. Silibinin, dexamethasone, and doxycycline as potential therapeutic agents for treating vesicant-inflicted ocular injuries

    Energy Technology Data Exchange (ETDEWEB)

    Tewari-Singh, Neera, E-mail: Neera.Tewari-Singh@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Jain, Anil K., E-mail: Anil.Jain@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Inturi, Swetha, E-mail: Swetha.Inturi@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Ammar, David A., E-mail: David.Ammar@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Agarwal, Chapla, E-mail: Chapla.Agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Tyagi, Puneet, E-mail: Puneet.Tyagi@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Kompella, Uday B., E-mail: Uday.Kompella@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States); Enzenauer, Robert W., E-mail: Robert.Enzenauer@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Petrash, J. Mark, E-mail: Mark.Petrash@ucdenver.edu [Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO 80045 (United States); Agarwal, Rajesh, E-mail: Rajesh.Agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO 80045 (United States)

    2012-10-01

    There are no effective and approved therapies against devastating ocular injuries caused by vesicating chemical agents sulfur mustard (SM) and nitrogen mustard (NM). Herein, studies were carried out in rabbit corneal cultures to establish relevant ocular injury biomarkers with NM for screening potential efficacious agents in laboratory settings. NM (100 nmol) exposure of the corneas for 2 h (cultured for 24 h), showed increases in epithelial thickness, ulceration, apoptotic cell death, epithelial detachment microbullae formation, and the levels of VEGF, cyclooxygenase-2 (COX-2) and matrix metalloproteinase-9 (MMP-9). Employing these biomarkers, efficacy studies were performed with agent treatments 2 h and every 4 h thereafter, for 24 h following NM exposure. Three agents were evaluated, including prescription drugs dexamethasone (0.1%; anti-inflammatory steroid) and doxycycline (100 nmol; antibiotic and MMP inhibitor) that have been studied earlier for treating vesicant-induced eye injuries. We also examined silibinin (100 μg), a non-toxic natural flavanone found to be effective in treating SM analog-induced skin injuries in our earlier studies. Treatments of doxycycline + dexamethasone, and silibinin were more effective than doxycycline or dexamethasone alone in reversing NM-induced epithelial thickening, microbullae formation, apoptotic cell death, and MMP-9 elevation. However, dexamethasone and silibinin alone were more effective in reversing NM-induced VEGF levels. Doxycycline, dexamethasone and silibinin were all effective in reversing NM-induced COX-2 levels. Apart from therapeutic efficacy of doxycycline and dexamethasone, these results show strong multifunctional efficacy of silibinin in reversing NM-induced ocular injuries, which could help develop effective and safe therapeutics against ocular injuries by vesicants. -- Highlights: ► Established injury biomarkers in rabbit corneal culture with nitrogen mustard (NM) ► This NM model is a cost effective

  20. Prophylactic antiemetic effects of midazolam, dexamethasone, and its combination after middle ear surgery

    International Nuclear Information System (INIS)

    Makhdoom, Naeem K; Farid, Magdy F

    2009-01-01

    To evaluate and compare the efficacy of the combination of midazolam and dexamethasone, with midazolam and dexamethasone alone, for the prevention of postoperative nausea and vomiting (PONV) in female patients undergoing middle ear surgery. A prospective, randomized, double-blind, placebo-controlled study in 80 female patients (mean age 32.6 years), undergoing middle ear surgery with general anesthesia at Ohud Hospital, Madina, Kingdom of Saudi Arabia from May 2007 to May 2008. Patients were classified into 4 groups. They received intravenous normal saline (S group), midazolam 0.075 mg/kg (M group), or dexamethasone 10 mg (D group), or a combination of midazolam and dexamethasone (MD group), before the induction of anesthesia. Postoperatively for 24 hours observation and assessment of nausea, vomiting, rescue anti-emetics, and side effects of the study drugs such as headache and drowsiness were carried out. There was a significant difference between the 4 groups. The MD group was the least to develop PONV compared to other groups (p<0.01). Regarding nausea, there was a non-significant difference between the 4 groups, although the MD group developed the least symptoms among the 4 groups, there were no significant differences in pain intensity and side effects such as, headache, dizziness, and drowsiness between the 4 groups. The combination of midazolam 0.075 mg/kg and dexamethasone 10 mg intravenously is better than either drug alone in reducing the incidence of PONV in female patients after middle ear surgery. (author)

  1. Optimised low-dose multidetector CT protocol for children with cranial deformity

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, Jose Luis [Complejo Hospitalario Universitario de Vigo, Department of Radiology, Vigo, Pontevedra (Spain); Pombar, Miguel Angel [Complejo Hospitalario Universitario de Santiago, Department of Radiophysics, Santiago de Compostela, La Coruna (Spain); Pumar, Jose Manuel [Complejo Hospitalario Universitario de Santiago, Department of Radiology, Santiago de Compostela, La Coruna (Spain); Campo, Victor Miguel del [Complejo Hospitalario Universitario de Vigo, Department of Public Health, Vigo, Pontevedra (Spain)

    2013-08-15

    To present an optimised low-dose multidetector computed tomography (MDCT) protocol for the study of children with cranial deformity. Ninety-one consecutive MDCT studies were performed in 80 children. Studies were performed with either our standard head CT protocol (group 1, n = 20) or a low-dose cranial deformity protocol (groups 2 and 3). Group 2 (n = 38), initial, and group 3 (n = 33), final and more optimised. All studies were performed in the same 64-MDCT equipment. Cranial deformity protocol was gradationally optimised decreasing kVp, limiting mA range, using automatic exposure control (AEC) and increasing the noise index (NI). Image quality was assessed. Dose indicators such us CT dose index volume (CTDIvol), dose-length product (DLP) and effective dose (E) were used. The optimised low-dose protocol reached the following values: 80 kVp, mA range: 50-150 and NI = 23. We achieved a maximum dose reduction of 10-22 times in the 1- to 12-month-old cranium in regard to the 2004 European guidelines for MDCT. A low-dose MDCT protocol that may be used as the first diagnostic imaging option in clinically selected patients with skull abnormalities. (orig.)

  2. Simultaneous RP-HPLC determination of sparfloxacin and dexamethasone in pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    Syed Naeem Razzaq

    2013-06-01

    Full Text Available The present study describes the development and subsequent validation of simple and accurate stability indicating RP-HPLC method for the determination of sparfloxacin and dexamethasone in pharmaceutical formulations in the presence of their stress-induced degradation products. Both the drugs and their stress-induced degradation products were separated within 10 minutes using C8 column and mixture of methanol and 0.02 M phosphate buffer pH 3.0 (60:40 v/v, respectively as mobile phase at 270 nm using diode array detector. Regression analysis showed linearity in the range of 15-105 µg/mL for sparfloxacin and 5-35 µg/mL for dexamethasone. All the analytes were adequately resolved with acceptable tailing. Peak purity of the two drugs was also greater than 0.9999, showing no co-elution peaks. The developed method was applied for simultaneous determination of sparfloxacin and dexamethasone in pharmaceutical formulations for stability studies.

  3. Pharmacological radionuclide ventriculography for detection of myocardial contractile reserve in patients after myocardial infarction: head-to-head comparison of low dose dobutamine and low dose dypiridamole

    International Nuclear Information System (INIS)

    Petrasinovic, Z.; Ostojic, M.; Beleslin, B.; Stojkovic, S.; Nedeljkovic, M.; Stankovic, G.; Dikic, A.; Pavlovic, S.; Sobic, D.

    2002-01-01

    Background. Low dose pharmacological stress echocardiography with either dobutamine or dipyridamole infusion has been proposed for recognition of myocardial viability. However, dependence on adequate acoustic window, observer experience, and the mild degree of wall motion changes make the viability assessment by stress echocardiography especially bothersome. The objective of the study was to evaluate the ability of low dose dobutamine and low dose dipyridamole radionuclide ventriculography to detect contractile reserve in patients after myocardial infarction and functional recovery after coronary angioplasty. Methods. The study group consisted of 20 consecutive patients (52±10 years, 17 male) with previous myocardial infarction and resting regional dyssynergy, in whom diagnostic cardiac catheterization revealed significant one-vessel coronary artery stenosis suitable for angioplasty. Each patient underwent equilibrium 99m-Tc radionuclide ventriculography which was performed at rest and during low dose dipyridamole (0.28 mg/kg over 2 minutes) and low dose dobutamine infusion (up to 10 mcg/kg/min). Left ventricular global and regional ejection fractions were determined. Increase of regional ejection fraction for >5% (inferoapical and posterolateral regions) or >10% (anteroseptal regions) during low dose dobutamine and dipyridamole in infarcted regions, as well as in the follow up period, was considered as index of contractile reserve. After 8 weeks of successful angioplasty, resting radionuclide ventriculography was repeated in all patients in order to identify functional recovery of the infarct zone. Results. Out of the 180 analyzed segments (20x9), 90 regional ejection fractions have shown depressed contractility. The mean of the regional ejection fractions showing depressed contractility increased from the resting value of 34±12% to 42±14% in the follow-up period (p=0.06). Of the 90 with baseline dyssynergy, 46 were responders during low-dose dobutamine (51

  4. Pinoresinol diglucoside exhibits protective effect on dexamethasone ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of pinoresinol diglucoside (PDG) on dexamethasone-induced osteoporosis in rats. Methods: Sixty Wistar rats were randomly and equally divided into normal, control, alendronate and PDG (10, 20 or 40 mg/kg) groups. Bone tissue parameters, including length, transverse diameter, weight, ...

  5. 21 CFR 520.540a - Dexamethasone powder.

    Science.gov (United States)

    2010-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.540a Dexamethasone powder. (a... such as acute arthritic lameness, and for various stress conditions where corticosteroids are required...

  6. Extremely low frequency electromagnetic field in combination with β ...

    African Journals Online (AJOL)

    Fatemeh Sanie-Jahromi

    Extremely low frequency (<300 Hz) electromagnetic field (EMF) is shown to decrease ... Production and hosting by Elsevier B.V. This is an open access article under ..... mouse liver induced by morphine and protected by antioxidants.

  7. Low dose iodine-131 therapy in solitary toxic thyroid nodules

    International Nuclear Information System (INIS)

    Prakash, Rajeev

    1999-01-01

    Forty patients with solitary hyperfunctioning thyroid nodules were treated with relatively low dose radioiodine therapy, 131 I doses were calculated taking into account thyroid mass and radioiodine kinetics to deliver 100 μCi/g of estimated nodule weight corrected for uptake. Patients remaining persistently hyperthyroid at four months after the initial therapy were retreated with a similarly calculated dose. Cure of the hyperthyroid state was achieved in all patients, total administered dose in individual cases ranging from 3-17 mCi. 28 of the 40 patients required a single therapy dose. 36 patients were euthyroid after a 4.5 year mean follow-up period. Four cases developed post therapy hypothyroidism requiring replacement therapy. Nodules regressed completely in nine cases following 131 I treatment, with partial regression in size in 19 patients. Control of hyperthyroid state in cases of solitary toxic thyroid nodules can be satisfactorily achieved using relatively low dose radioiodine therapy with low incidence of post therapy hypothyroidism. (author)

  8. Pre-operative use of dexamethasone does not reduce incidence or intensity of bleaching-induced tooth sensitivity. A triple-blind, parallel-design, randomized clinical trial.

    Science.gov (United States)

    da Costa Poubel, Luiz Augusto; de Gouvea, Cresus Vinicius Deppes; Calazans, Fernanda Signorelli; Dip, Etyene Castro; Alves, Wesley Veltri; Marins, Stella Soares; Barcelos, Roberta; Barceleiro, Marcos Oliveira

    2018-04-25

    This study evaluated the effect of the administration of pre-operative dexamethasone on tooth sensitivity stemming from in-office bleaching. A triple-blind, parallel-design, randomized clinical trial was conducted on 70 volunteers who received dexamethasone or placebo capsules. The drugs were administered in a protocol of three daily 8-mg doses of the drug, starting 48 h before the in-office bleaching treatment. Two bleaching sessions with 37.5% hydrogen peroxide gel were performed with a 1-week interval. Tooth sensitivity (TS) was recorded on visual analog scales (VAS) and numeric rating scales (NRS) in different periods up to 48 h after bleaching. The color evaluations were also performed. The absolute risk of TS and its intensity were evaluated by using Fisher's exact test. Comparisons of the TS intensity (NRS and VAS data) were performed by using the Mann-Whitney U test and a two-way repeated measures ANOVA and Tukey's test, respectively. In both groups, a high risk of TS (Dexa 80% x Placebo 94%) was detected. No significant difference was observed in terms of TS intensity. A whitening of approximately 3 shade guide units of the VITA Classical was detected in both groups, which were statistically similar. It was concluded that the administration pre-operatively of dexamethasone, in the proposed protocol, does not reduce the incidence or intensity of bleaching-induced tooth sensitivity. The use of dexamethasone drug before in-office bleaching treatment does not reduce incidence or intensity of tooth sensitivity. NCT02956070.

  9. Extremely Low Mass: The Circumstellar Envelope of a Potential Proto-Brown Dwarf

    Science.gov (United States)

    Wiseman, Jennifer

    2011-01-01

    What is the environment for planet formation around extremely low mass stars? Is the environment around brown dwarfs and extremely low mass stars conducive and sufficiently massive for planet production? The determining conditions may be set very early in the process of the host object's formation. IRAS 16253-2429, the source of the Wasp-Waist Nebula seen in Spitzer IRAC images, is an isolated, very low luminosity ("VeLLO") Class 0 protostar in the nearby rho Ophiuchi cloud. We present VLA ammonia mapping observations of the dense gas envelope feeding the central core accreting system. We find a flattened envelope perpendicular to the outflow axis, and gas cavities that appear to cradle the outflow lobes as though carved out by the flow and associated (apparently precessing) jet, indicating environmental disruption. Based on the NH3 (1,1) and (2,2) emission distribution, we derive the mass, velocity fields and temperature distribution for the envelope. We discuss the combined evidence for this source to be one of the youngest and lowest mass sources in formation yet known, and discuss the ramifications for planet formation potential in this extremely low mass system.

  10. Endometrial safety of ultra-low-dose estradiol vaginal tablets

    DEFF Research Database (Denmark)

    Simon, James; Nachtigall, Lila; Ulrich, Lian G

    2010-01-01

    To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17ß-estradiol vaginal tablets in postmenopausal women with vaginal atrophy.......To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17ß-estradiol vaginal tablets in postmenopausal women with vaginal atrophy....

  11. Endometrial safety of ultra-low-dose estradiol vaginal tablets

    DEFF Research Database (Denmark)

    Simon, James; Nachtigall, Lila; Ulrich, Lian G

    2010-01-01

    To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17β-estradiol vaginal tablets in postmenopausal women with vaginal atrophy.......To evaluate the endometrial hyperplasia and carcinoma rate after 52-week treatment with ultra-low-dose 10-microgram 17β-estradiol vaginal tablets in postmenopausal women with vaginal atrophy....

  12. Low-dose prophylactic craniospinal radiotherapy for intracranial germinoma

    International Nuclear Information System (INIS)

    Schoenfeld, Gordon O.; Amdur, Robert J.; Schmalfuss, Ilona M.; Morris, Christopher G.; Keole, Sameer R.; Mendenhall, William M.; Marcus, Robert B.

    2006-01-01

    Purpose: To report outcomes of patients with localized intracranial germinoma treated with low-dose craniospinal irradiation (CSI) followed by a boost to the ventricular system and primary site. Methods and Materials: Thirty-one patients had pathologically confirmed intracranial germinoma and no spine metastases. Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction. Our neuroradiologist recorded three-dimensional tumor size on magnetic resonance images before, during, and after radiotherapy. Results: With a median follow-up of 7.0 years, 29 of 31 patients (94%) are disease free. One failure had nongerminomatous histology; the initial diagnosis was a sampling error. Of 3 patients who did not receive CSI, 1 died. No patient developed myelopathy, visual deficits, dementia, or skeletal growth problems. In locally controlled patients, tumor response according to magnetic resonance scan was nearly complete within 6 months after radiotherapy. Conclusions: Radiotherapy alone with low-dose prophylactic CSI cures almost all patients with localized intracranial germinoma. Complications are rare when the daily dose of radiotherapy is limited to 1.5 Gy and the total CSI dose to 21 Gy. Patients without a near-complete response to radiotherapy should undergo resection to rule out a nongerminomatous element

  13. Low level dose induced chromosome aberrations in human blood lymphocytes

    International Nuclear Information System (INIS)

    Pohl-Rueling, J.

    1992-01-01

    Unstable structural aberrations in chromosomes of human blood lymphocytes cannot be used as biological dosemeters in the low dose range, when extrapolating from high doses using a linear dose response, as required by the original formula of the dual radiation action theory. A survey is given of experimental dose-response curves of chromosome aberrations, obtained in investigations not only by this institute, in cooperation with many other laboratories, but also by various authors in different areas of the world. The results are not compatible with the predicted linear dose relationships at in vivo dose ranges up to 30 mGy.y -1 . The aberration frequencies rise sharply with dose within the normal environmental exposure up to about twice that level. At higher doses, aberration frequencies increase less rapidly and reach a plateau. Some in vitro experiments of various authors with higher doses of low LET radiations, up to about 400 mGy have found dose responses with steps. (author)

  14. Review of European research trends of low dose radiation risk

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Yoshida, Kazuo

    2010-01-01

    Large research projects on low dose radiation effects in Europe and US over the past decade have provided limited scientific knowledge which could underpin the validation of radiation protection systems. Recently in Europe, there have been repeated discussions and dialogues to improve the situation, and as the consequence, the circumstances surrounding low dose radiation risks are changing. In 2009, Multidisciplinary European Low Dose Initiative (MELODI) was established as a trans-national organization capable of ensuring appropriate governance of research in the pursuit of a long term shared vision, and Low Dose Research towards Multidisciplinary Integration (DoReMi) network was launched in 2010 to achieve fairly short term results in order to prove the validity of the MELODI approach. It is expected to be very effective and powerful activities to facilitate the reduction of uncertainties in the understanding of low dose risks, but the regulatory requests rushing the reinforcement of radiological protection regulations based on the precautional principles are more increasing. To develop reasonable radiological protection systems based on scientific evidences, we need to accelerate to collect scientific evidences which could directly underpin more appropriate radiation protection systems even in Japan. For the purpose, we Japan need to develop from an independent standpoint and share as a multidisciplinary vision a long term and holistic research strategy which enables to enhance Japanese advantages such as low dose rate facilities and animal facilities, as soon as possible. (author)

  15. Peripheral chemoreflex inhibition with low-dose dopamine: new insight into mechanisms of extreme apnea.

    Science.gov (United States)

    Bain, Anthony R; Dujic, Zeljko; Hoiland, Ryan L; Barak, Otto F; Madden, Dennis; Drvis, Ivan; Stembridge, Mike; MacLeod, David B; MacLeod, Douglas M; Ainslie, Philip N

    2015-11-01

    The purpose of this study was to determine the impact of peripheral chemoreflex inhibition with low-dose dopamine on maximal apnea time, and the related hemodynamic and cerebrovascular responses in elite apnea divers. In a randomized order, participants performed a maximal apnea while receiving either intravenous 2 μg·kg(-1)·min(-1) dopamine or volume-matched saline (placebo). The chemoreflex and hemodynamic response to dopamine was also assessed during hypoxia [arterial O2 tension, (PaO2 ) ∼35 mmHg] and mild hypercapnia [arterial CO2 tension (PaCO2 ) ∼46 mmHg] that mimicked the latter parts of apnea. Outcome measures included apnea duration, arterial blood gases (radial), heart rate (HR, ECG), mean arterial pressure (MAP, intra-arterial), middle (MCAv) and posterior (PCAv) cerebral artery blood velocity (transcranial ultrasound), internal carotid (ICA) and vertebral (VA) artery blood flow (ultrasound), and the chemoreflex responses. Although dopamine depressed the ventilatory response by 27 ± 41% (vs. placebo; P = 0.01), the maximal apnea duration was increased by only 5 ± 8% (P = 0.02). The PaCO2 and PaO2 at apnea breakpoint were similar (P > 0.05). When compared with placebo, dopamine increased HR and decreased MAP during both apnea and chemoreflex test (P all breathe. Copyright © 2015 the American Physiological Society.

  16. Modeling low-dose-rate effects in irradiated bipolar-base oxides

    International Nuclear Information System (INIS)

    Graves, R.J.; Cirba, C.R.; Schrimpf, R.D.; Milanowski, R.J.; Saigne, F.; Michez, A.; Fleetwood, D.M.; Witczak, S.C.

    1997-02-01

    A physical model is developed to quantify the contribution of oxide-trapped charge to enhanced low-dose-rate gain degradation in BJTs. Simulations show that space charge limited transport is partially responsible for the low-dose-rate enhancement

  17. Low-dose-rate total lymphoid irradiation: a new method of rapid immunosuppression

    International Nuclear Information System (INIS)

    Blum, J.E.; de Silva, S.M.; Rachman, D.B.; Order, S.E.

    1988-01-01

    Total Lymphoid Irradiation (TLI) has been successful in inducing immunosuppression in experimental and clinical applications. However, both the experimental and clinical utility of TLI are hampered by the prolonged treatment courses required (23 days in rats and 30-60 days in humans). Low-dose-rate TLI has the potential of reducing overall treatment time while achieving comparable immunosuppression. This study examines the immunosuppressive activity and treatment toxicity of conventional-dose-rate (23 days) vs low-dose-rate (2-7 days) TLI. Seven groups of Lewis rats were given TLI with 60Co. One group was treated at conventional-dose-rates (80-110 cGy/min) and received 3400 cGy in 17 fractions over 23 days. Six groups were treated at low-dose-rate (7 cGy/min) and received total doses of 800, 1200, 1800, 2400, 3000, and 3400 cGy over 2-7 days. Rats treated at conventional-dose-rates over 23 days and at low-dose-rate over 2-7 days tolerated radiation with minimal toxicity. The level of immunosuppression was tested using allogeneic (Brown-Norway) skin graft survival. Control animals retained allogeneic skin grafts for a mean of 14 days (range 8-21 days). Conventional-dose-rate treated animals (3400 cGy in 23 days) kept their grafts 60 days (range 50-66 days) (p less than .001). Low-dose-rate treated rats (800 to 3400 cGy total dose over 2-7 days) also had prolongation of allogeneic graft survival times following TLI with a dose-response curve established. The graft survival time for the 3400 cGy low-dose-rate group (66 days, range 52-78 days) was not significantly different from the 3400 cGy conventional-dose-rate group (p less than 0.10). When the total dose given was equivalent, low-dose-rate TLI demonstrated an advantage of reduced overall treatment time compared to conventional-dose-rate TLI (7 days vs. 23 days) with no increase in toxicity

  18. Effect of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity.

    Science.gov (United States)

    Topdag, M; Iseri, M; Gelenli, E; Yardimoglu, M; Yazir, Y; Ulubil, S A; Topdag, D O; Ustundag, E

    2012-11-01

    This study aimed to contribute to the literature on the prevention and treatment of ototoxicity due to various drugs and chemicals. This study compared the histological effects of intratympanic dexamethasone, memantine and piracetam on cellular apoptosis due to cisplatin ototoxicity, in 36 rats. Dexamethasone and memantine had significant effects on the stria vascularis, organ of Corti and spiral ganglion (p piracetam decreased the apoptosis rate, this effect was not statistically significant (p > 0.05). Dexamethasone and memantine were found superior to piracetam in reducing apoptosis due to cisplatin ototoxicity. Further studies of this subject are needed, incorporating electron microscopy and auditory brainstem response testing.

  19. MELODI: The 'Multidisciplinary European Low-Dose Initiative'

    International Nuclear Information System (INIS)

    Belli, M.; Salomaa, S.; Ottolenghi, A.

    2011-01-01

    The importance of research to reduce uncertainties in risk assessment of low and protracted exposures is now recognised globally. In Europe a new initiative, called 'Multidisciplinary European Low Dose Initiative' (MELODI), has been proposed by a 'European High Level and Expert Group on low-dose risk research' (www.hleg.de), aimed at integrating national and EC (Euratom) efforts. Five national organisations: BfS (DE), CEA (FR), IRSN (FR), ISS (IT) and STUK (FI), with the support of the EC, have initiated the creation of MELODI by signing a letter of intent. In the forthcoming years, MELODI will integrate in a step-by-step approach EU institutions with significant programmes in the field and will be open to other scientific organisations and stakeholders. A key role of MELODI is to develop and maintain over time a strategic research agenda (SRA) and a road map of scientific priorities within a multidisciplinary approach, and to transfer the results for the radiation protection system. Under the coordination of STUK a network has been proposed in the 2009 Euratom Programme, called DoReMi (Low-Dose Research towards Multidisciplinary Integration), which can help the integration process within the MELODI platform. DoReMi and the First MELODI Open Workshop, organised by BfS in September 2009, are now important inputs for the European SRA. (authors)

  20. Evaluating the patient experience after implantation of a 0.4 mg sustained release dexamethasone intracanalicular insert (DextenzaTM: results of a qualitative survey

    Directory of Open Access Journals (Sweden)

    Gira JP

    2017-03-01

    Full Text Available Joseph P Gira,1 Reginald Sampson,2 Steven M Silverstein,3 Thomas R Walters,4 Jamie Lynne Metzinger,5 Jonathan H Talamo5 1Ophthalmology Consultants, St Louis, MO, 2Montebello Medical Center, Inc., Montebello, CA, 3Silverstein Eye Centers, Kansas City, MO, 4Texan Eye, Austin, TX, 5Ocular Therapeutix, Inc., Bedford, MA, USA Purpose: The purpose of this study is to evaluate the patient experience of sustained release dexamethasone intracanalicular insert (Dextenza™ following cataract surgery as part of a Phase III clinical trial program. Methods: This cross-sectional, qualitative evaluation involved individual interviews lasting approximately 45 minutes. Patients from four US investigational study sites who had previously received an insert were enrolled. There were no predesignated end points; this was a qualitative survey seeking a deeper understanding of patient experience. Results: Twenty-five patients were interviewed. Most patients (92% reported the highest level of satisfaction grade with regard to overall product satisfaction. All patients described the insert as comfortable. Most patients (96% described their overall experience with the insert as very convenient or extremely convenient. Twenty-two of 23 (96% participants rated their experience with the insert as “very” or “extremely convenient”, compared to previous topical therapy, and 88% of patients stated that if they were to undergo cataract surgery again, they would request the insert. When asked if they would recommend the insert to family members or friends, 92% stated they would. The survey found that 84% of participants would be willing to pay more for the insert than for eye drop therapy. Conclusion: The dexamethasone insert was found by patients to be highly favorable with regard to overall satisfaction, convenience, and comfort. The insert was well received and largely preferred over topical therapy alternatives following surgery. More extensive evaluation of the

  1. Intracranial germinomas: a case for low dose radiation therapy alone

    International Nuclear Information System (INIS)

    Harrigan, Patricia M.; Loeffler, Jay S.; Shrieve, Dennis; Tarbell, Nancy J.

    1995-01-01

    Purpose: To determine the optimal dose and treatment outcome of patients treated with radiation for intracranial germinoma. Materials and Methods: Between 1975 and 1995, 39 patients with a diagnosis of intracranial germinoma were treated with radiation (RT) to the central nervous system. All but one pt received whole brain (WB) RT, (median dose: 3240 cGy range: 1500-4437 cGy) and a boost to the tumor volume (median total tumor volume dose: 5200 cGy, range: 3960-5950 cGy). Thirty-one pts received RT to the spine (median dose: 2500, range: 1875-3750). Eleven pts were treated with low dose RT and a tumor volume boost, (WB dose ≤ 2550 cGy, and spine dose ≤ 2160 cGy). Five pts were treated with cisplatin-based chemotherapy and low dose WB RT. Fifteen pts were biopsy-proven and 18 presented with multiple midline germinomas (MMG). Among all pts, 33% had serum or CSF positive for low levels of HCG and none of 19 (9 biopsy-proven) germinomas measured positive for AFP tumor marker. Six of 22 (27%) pts who had spine imaging or CSF cytology had evidence of tumor seeding. The male-to female-ratio was 1.4. Median age at diagnosis was 14 yrs for male pts and 9.5 yrs for females (p=.02, overall age range: 1-31 yrs). Median follow-up for survivors is 64 months (range: 1-226 months). Toxicity of treatment relative to dose was assessed. Results: The 5-yr. actuarial rate of disease-free survival (DFS) and overall survival for presumed germinomas was 97%. No pts died of germinoma. One pt died of a shunt infection who had received concurrent chemotherapy and low dose whole brain RT. Among the low dose RT alone group 6 pts received whole brain RT of ≤ 2550 cGy and 9 pts were treated with spinal RT of ≤ 2160 cGy without chemotherapy. Two of these pts had CSF cytology positive for tumor seeding. Additionally, 8 pts received a total dose to the tumor volume of ≤ 4800 cGy without chemotherapy. The 5-yr DFS was 100%. Five pts were treated with cisplatin-based chemotherapy followed

  2. Intracranial germinomas: a case for low dose radiation therapy alone

    Energy Technology Data Exchange (ETDEWEB)

    Harrigan, Patricia M; Loeffler, Jay S; Shrieve, Dennis; Tarbell, Nancy J

    1995-07-01

    Purpose: To determine the optimal dose and treatment outcome of patients treated with radiation for intracranial germinoma. Materials and Methods: Between 1975 and 1995, 39 patients with a diagnosis of intracranial germinoma were treated with radiation (RT) to the central nervous system. All but one pt received whole brain (WB) RT, (median dose: 3240 cGy range: 1500-4437 cGy) and a boost to the tumor volume (median total tumor volume dose: 5200 cGy, range: 3960-5950 cGy). Thirty-one pts received RT to the spine (median dose: 2500, range: 1875-3750). Eleven pts were treated with low dose RT and a tumor volume boost, (WB dose {<=} 2550 cGy, and spine dose {<=} 2160 cGy). Five pts were treated with cisplatin-based chemotherapy and low dose WB RT. Fifteen pts were biopsy-proven and 18 presented with multiple midline germinomas (MMG). Among all pts, 33% had serum or CSF positive for low levels of HCG and none of 19 (9 biopsy-proven) germinomas measured positive for AFP tumor marker. Six of 22 (27%) pts who had spine imaging or CSF cytology had evidence of tumor seeding. The male-to female-ratio was 1.4. Median age at diagnosis was 14 yrs for male pts and 9.5 yrs for females (p=.02, overall age range: 1-31 yrs). Median follow-up for survivors is 64 months (range: 1-226 months). Toxicity of treatment relative to dose was assessed. Results: The 5-yr. actuarial rate of disease-free survival (DFS) and overall survival for presumed germinomas was 97%. No pts died of germinoma. One pt died of a shunt infection who had received concurrent chemotherapy and low dose whole brain RT. Among the low dose RT alone group 6 pts received whole brain RT of {<=} 2550 cGy and 9 pts were treated with spinal RT of {<=} 2160 cGy without chemotherapy. Two of these pts had CSF cytology positive for tumor seeding. Additionally, 8 pts received a total dose to the tumor volume of {<=} 4800 cGy without chemotherapy. The 5-yr DFS was 100%. Five pts were treated with cisplatin-based chemotherapy

  3. Treatment results by uneven fractionated irradiation, low-dose rate telecobalt therapy as a boost, and intraoperative irradiation for malignant glioma

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Shogo; Takai, Yoshihiro; Nemoto, Kenji; Ogawa, Yoshihiro; Kakuto, Yoshihisa; Hoshi, Akihiko; Sakamoto, Kiyohiko; Kayama, Takamasa; Yoshimoto, Takashi (Tohoku Univ., Sendai (Japan). School of Medicine)

    1992-08-01

    The prognosis of malignant glioma is extremely poor. We applied conventionally fractionated irradiation combined with 1-(4-aminio-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), uneven fractionated irradiation with ACNU, low dose rate telecobalt therapy as a boost, and intraoperative irradiation against 110 malignant gliomas to investigate the efficacy of these methods as alternative treatments for malignant glioma. Although local tumor control by uneven fractionated irradiation was better than that by the other methods, no significant improvement was obtained in survival rates. As a result of multiple regression analysis, age and histology were major factors for survival rates, and the difference of treatment methods was not important. Both low-dose rate telecobalt therapy as a boost and intraoperative irradiation showed little advantage because of the high risk of brain necrosis associated with them. (author).

  4. Multilevel mechanisms of stimulatory effect of low dose radiation on immunity

    International Nuclear Information System (INIS)

    Shu-Zeng Liu

    1992-01-01

    Attention is paid to the effects of low level ionizing radiation on humans. The conference is devoted to low dose radiation and defense mechanisms of the body. Due to the importance of the immune system in body resistance, special attention has been given to host defense mechanisms following exposure to different doses of ionizing radiation. The immune system has long been known to be highly sensitive to moderate to high doses of ionizing radiation with immuno-depression as one of the most important causes of death in acute radiation syndrome. However, the dose-effect relationship of immune functions has been found to be quite different in the low dose range, especially with doses within 0.1 Gy. With doses above 0.5 Gy most immunologic parameters show a dose dependent depression. With doses between 0.1-0.5 Gy there may be no definite changes in immune functions. Doses within 0.1 Gy, given in single or chronic exposures, have been found to stimulate many immune responses. (author). 16 refs., 2 figs., 7 tabs

  5. Comparative study of preoperative use of oral gabapentin, intravenous dexamethasone and their combination in gynaecological procedure

    Directory of Open Access Journals (Sweden)

    Neha Agrawal

    2015-01-01

    Full Text Available Background: We studied the effects of oral gabapentin and intravenous (I.V. dexamethasone given together or separately 1 h before the start of surgery on intraoperative hemodynamics Postoperative analgesia and postoperative nausea vomiting (PONV in patients undergoing gynaecological procedure. Materials and Methods: Patients were randomly divided into three groups: Group 1 (gabapentin, n = 46 received 400 mg gabapentin, Group 2 (dexamethasone, n = 46 received 8 mg dexamethasone and Group 3 (gabapentin plus dexamethasone, n = 46 received both 400 mg gabapentin and 8 mg dexamethasone I.V. 1 h before the start of surgery. Standard induction and maintenance of anesthesia were accomplished. Visual analog scale for pain was recorded for 12 h. Side effects were noted. Results: Hemodynamics at various time interval (0, 5, 10, 15, 20, 25 and 30 min of laryngeal mask airway insertion and PONV were found significantly lower in Group 3 than in Group 1 and Group 2 (P 3 was significantly longer in Group 3 (510.00 ± 61.64 min than in Group 1 (352.83 ± 80.61 min and in Group 2 (294.78 ± 60.76 min, (P < 0.05. Conclusion: The present study concludes that the combination of oral Gabapentin and I.V. dexamethasone has significantly less hemodynamic changes, better postoperative analgesia and less incidence of PONV than individual administration of each drug.

  6. Low-Dose Radiation Exposure and Atherosclerosis in ApoE(-/-) Mice

    NARCIS (Netherlands)

    Mitchel, R. E. J.; Hasu, M.; Bugden, M.; Wyatt, H.; Little, M. P.; Gola, A.; Hildebrandt, G.; Priest, N. D.; Whitman, S. C.

    The hypothesis that single low-dose exposures (0.025-0.5 Gy) to low-LET radiation given at either high (about 150 mGy/min) or low (1 mGy/min) dose rate would promote aortic atherosclerosis was tested in female C57BL/6J mice genetically predisposed to this disease (ApoE(-/-)). Mice were exposed

  7. Biological Effects of Low-Dose Exposure

    CERN Document Server

    Komochkov, M M

    2000-01-01

    On the basis of the two-protection reaction model an analysis of stochastic radiobiological effects of low-dose exposure of different biological objects has been carried out. The stochastic effects are the results published in the last decade: epidemiological studies of human cancer mortality, the yield of thymocyte apoptosis of mice and different types of chromosomal aberrations. The results of the analysis show that as dependent upon the nature of biological object, spontanous effect, exposure conditions and radiation type one or another form dose - effect relationship is realized: downwards concave, near to linear and upwards concave with the effect of hormesis included. This result testifies to the incomplete conformity of studied effects of 1990 ICRP recomendations based on the linear no-threshold hypothesis about dose - effect relationship. Because of this the methodology of radiation risk estimation recomended by ICRP needs more precisian and such quantity as collective dose ought to be classified into...

  8. Enhanced low dose rate radiation effect test on typical bipolar devices

    International Nuclear Information System (INIS)

    Liu Minbo; Chen Wei; Yao Zhibin; He Baoping; Huang Shaoyan; Sheng Jiangkun; Xiao Zhigang; Wang Zujun

    2014-01-01

    Two types of bipolar transistors and nine types bipolar integrated circuit were selected in the irradiation experiment at different "6"0Co γ dose rate. The base current of bipolar transistor and input bias current of amplifier and comparator was measured, low dose enhance factor of test device was obtained. The results show that bipolar device have enhanced low dose rate sensitivity, enhancement factor of bipolar integrated circuit was bigger than that of transistor, and enhanced low dose rate sensitivity greatly varied with different structure and process of bipolar device. (authors)

  9. Low dose effects and non-monotonic dose responses for endocrine active chemicals: Science to practice workshop: Workshop summary

    DEFF Research Database (Denmark)

    Beausoleil, Claire; Ormsby, Jean-Nicolas; Gies, Andreas

    2013-01-01

    A workshop was held in Berlin September 12–14th 2012 to assess the state of the science of the data supporting low dose effects and non-monotonic dose responses (“low dose hypothesis”) for chemicals with endocrine activity (endocrine disrupting chemicals or EDCs). This workshop consisted of lectu...

  10. Acute Activation of Metabolic Syndrome Components in Pediatric Acute Lymphoblastic Leukemia Patients Treated with Dexamethasone

    NARCIS (Netherlands)

    Warris, Lidewij T.; van den Akker, Erica L. T.; Bierings, Marc B.; van den Bos, Cor; Zwaan, Christian M.; Sassen, Sebastiaan D. T.; Tissing, Wim J. E.; Veening, Margreet A.; Pieters, Rob; van den Heuvel-Eibrink, Marry M.

    2016-01-01

    Although dexamethasone is highly effective in the treatment of pediatric acute lymphoblastic leukemia (ALL), it can cause serious metabolic side effects. Because studies regarding the effects of dexamethasone are limited by their small scale, we prospectively studied the direct effects of treating

  11. Injury of the blood-testies barrier after low-dose-rate chronic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Young Hoon; Bae Min Ji; Lee, Chang Geun; Yang, Kwang Mo; Jur, Kyu; Kim, Jong Sun [Dongnam Institute of Radiological and Medical Science, Busan (Korea, Republic of)

    2014-04-15

    The systemic effect of radiation increases in proportionally with the dose and dose rate. Little is known concerning the relationships between harmful effects and accumulated dose, which is derived from continuous low-dose rate radiation exposure. Recent our studies show that low-dose-rate chronic radiation exposure (3.49 mGy/h) causes adverse effects in the testis at a dose of 2 Gy (6 mGy/h). However, the mechanism of the low-dose-rate 2 Gy irradiation induced testicular injury remains unclear. The present results indicate that low-dose rate chronic radiation might affect the BTB permeability, possibly by decreasing levels of ZO-1, Occludin-1, and NPC-2. Furthermore, our results suggest that there is a risk of male infertility through BTB impairment even with low-dose-rate radiation if exposure is continuous.

  12. Granisetron plus dexamethasone for prevention of postoperative nausea and vomiting in patients undergoing laparoscopic surgery: A meta-analysis.

    Science.gov (United States)

    Zhu, Min; Zhou, Chengmao; Huang, Bing; Ruan, Lin; Liang, Rui

    2017-06-01

    Objective This study was designed to compare the effectiveness of granisetron plus dexamethasone for preventing postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic surgery. Methods We searched the literature in the Cochrane Library, PubMed, EMBASE, and CNKI. Results In total, 11 randomized controlled trials were enrolled in this analysis. The meta-analysis showed that granisetron in combination with dexamethasone was significantly more effective than granisetron alone in preventing PONV in patients undergoing laparoscopy surgery. No significant differences in adverse reactions (dizziness and headache) were found in association with dexamethasone. Conclusion Granisetron in combination with dexamethasone was significantly more effective than granisetron alone in preventing PONV in patients undergoing laparoscopic surgery, with no difference in adverse reactions between the two groups. Granisetron alone or granisetron plus dexamethasone can be used to prevent PONV in patients undergoing laparoscopic surgery.

  13. Response of human fibroblasts to low dose rate gamma irradiation

    International Nuclear Information System (INIS)

    Dritschilo, A.; Brennan, T.; Weichselbaum, R.R.; Mossman, K.L.

    1984-01-01

    Cells from 11 human strains, including fibroblasts from patients with the genetic diseases of ataxia telangiectasia (AT), xeroderma pigmentosum (XP), and Fanconi's anemia (FA), were exposed to γ radiation at high (1.6-2.2 Gy/min) and at low (0.03-0.07 Gy/min) dose rates. Survival curves reveal an increase inthe terminal slope (D 0 ) when cells are irradiated at low dose rates compared to high dose rates. This was true for all cell lines tested, although the AT, FA, and XP cells are reported or postulated to have radiation repair deficiencies. From the response of these cells, it is apparent that radiation sensitivities differ; however, at low dose rate, all tested human cells are able to repair injury

  14. Low Dose Ionizing Radiation Modulates Immune Function

    International Nuclear Information System (INIS)

    Nelson, Gregory A.

    2016-01-01

    In order to examine the effects of low dose ionizing radiation on the immune system we chose to examine an amplified adaptive cellular immunity response. This response is Type IV delayed-type hypersensitivity also called contact hypersensitivity. The agent fluorescein isothiocyanate (FITC) is a low molecular weight, lipophilic, reactive, fluorescent molecule that can be applied to the skin where it (hapten) reacts with proteins (carriers) to become a complete antigen. Exposure to FITC leads to sensitization which is easily measured as a hypersensitivity inflammatory reaction following a subsequent exposure to the ear. Ear swelling, eosinophil infiltration, immunoglobulin E production and cytokine secretion patterns characteristic of a 'Th2 polarized' immune response are the components of the reaction. The reaction requires successful implementation of antigen processing and presentation by antigen presenting Langerhans cells, communication with naïve T lymphocytes in draining lymph nodes, expansion of activated T cell clones, migration of activated T cells to the circulation, and recruitment of memory T cells, macrophages and eosinophils to the site of the secondary challenge. Using this model our approach was to quantify system function rather than relying only on indirect biomarkers of cell. We measured the FITC-induced hypersensitivity reaction over a range of doses from 2 cGy to 2 Gy. Irradiations were performed during key events or prior to key events to deplete critical cell populations. In addition to quantifying the final inflammatory response, we assessed cell populations in peripheral blood and spleen, cytokine signatures, IgE levels and expression of genes associated with key processes in sensitization and elicitation/recall. We hypothesized that ionizing radiation would produce a biphasic effect on immune system function resulting in an enhancement at low doses and a depression at higher doses and suggested that this transition would occur in

  15. Low Dose Ionizing Radiation Modulates Immune Function

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Gregory A. [Loma Linda Univ., CA (United States)

    2016-01-12

    In order to examine the effects of low dose ionizing radiation on the immune system we chose to examine an amplified adaptive cellular immunity response. This response is Type IV delayed-type hypersensitivity also called contact hypersensitivity. The agent fluorescein isothiocyanate (FITC) is a low molecular weight, lipophilic, reactive, fluorescent molecule that can be applied to the skin where it (hapten) reacts with proteins (carriers) to become a complete antigen. Exposure to FITC leads to sensitization which is easily measured as a hypersensitivity inflammatory reaction following a subsequent exposure to the ear. Ear swelling, eosinophil infiltration, immunoglobulin E production and cytokine secretion patterns characteristic of a “Th2 polarized” immune response are the components of the reaction. The reaction requires successful implementation of antigen processing and presentation by antigen presenting Langerhans cells, communication with naïve T lymphocytes in draining lymph nodes, expansion of activated T cell clones, migration of activated T cells to the circulation, and recruitment of memory T cells, macrophages and eosinophils to the site of the secondary challenge. Using this model our approach was to quantify system function rather than relying only on indirect biomarkers of cell. We measured the FITC-induced hypersensitivity reaction over a range of doses from 2 cGy to 2 Gy. Irradiations were performed during key events or prior to key events to deplete critical cell populations. In addition to quantifying the final inflammatory response, we assessed cell populations in peripheral blood and spleen, cytokine signatures, IgE levels and expression of genes associated with key processes in sensitization and elicitation/recall. We hypothesized that ionizing radiation would produce a biphasic effect on immune system function resulting in an enhancement at low doses and a depression at higher doses and suggested that this transition would occur in the

  16. Low doses of neutrons induce changes in gene expression

    International Nuclear Information System (INIS)

    Woloschak, G.E.; Chang-Liu, C.M.; Panozzo, J.; Libertin, C.R.

    1993-01-01

    Studies were designed to identify genes induced following low-dose neutron but not following γ-ray exposure in fibroblasts. Our past work had shown differences in the expression of β-protein kinase C and c-fos genes, both being induced following γ-ray but not neutron exposure. We have identified two genes that are induced following neutron, but not γ-ray, exposure: Rp-8 (a gene induced by apoptosis) and the long terminal repeat (LTR) of the human immunodeficiency (HIV). Rp-8 mRNA induction was demonstrated in Syrian hamster embryo fibroblasts and was found to be induced in cells exposed to neutrons administered at low (0.5 cGy/min) and at high dose rate (12 cGy/min). The induction of transcription from the LTR of HIV was demonstrated in HeLa cells bearing a transfected construct of the chloramphenicol acetyl transferase (CAT) gene driven by the HIV-LTR promoter. Measures of CAT activity and CAT transcripts following irradiation demonstrated an unresponsiveness to γ rays over a broad range of doses. Twofold induction of the HIV-LTR was detected following neutron exposure (48 cGy) administered at low (0.5 cGy/min) but not high (12 cGy/min) dose rates. Ultraviolet-mediated HIV-LTR induction was inhibited by low-dose-rate neutron exposure

  17. Attributability of health effects at low radiation doses

    International Nuclear Information System (INIS)

    Gonzalez, Abel

    2008-01-01

    Full text: A controversy still persists on whether health effects can be alleged from radiation exposure situations involving low radiation doses (e.g. below the international dose limits for the public). Arguments have evolved around the validity of the dose-response representation that is internationally used for radiation protection purposes, namely the so-called linear-non-threshold (LNT) model. The debate has been masked by the intrinsic randomness of radiation interaction at the cellular level and also by gaps in the relevant scientific knowledge on the development and expression of health effects. There has also been a vague use, abuse, and misuse of radiation-related risk concepts and quantities and their associated uncertainties. As a result, there is some ambiguity in the interpretation of the phenomena and a general lack of awareness of the implications for a number of risk-causation qualities, namely its attributes and characteristics. In particular, the LNT model has been used not only for protection purposes but also for blindly attributing actual effects to specific exposure situations. The latter has been discouraged as being a misuse of the model, but the supposed incorrectness has not been clearly proven. The paper will endeavour to demonstrate unambiguously the following thesis in relation to health effects due to low radiation doses: 1) Their existence is highly plausible. A number of epidemiological statistical assessments of sufficiently large exposed populations show that, under certain conditions, the prevalence of the effects increases with dose. From these assessments, it can be hypothesized that the occurrence of the effects at any dose, however small, appears decidedly worthy of belief. While strictly the evidence does not allow to conclude that a threshold dose level does not exist either. In fact, a formal quantitative uncertainty analysis, combining the different uncertain components of estimated radiation-related risk, with and

  18. Attributability of Health Effects at Low Radiation Doses

    International Nuclear Information System (INIS)

    Gonzalez, A.J.

    2011-01-01

    Full text: A controversy still persists on whether health effects can be alleged from radiation exposure situations involving low radiation doses (e.g. below the international dose limits for the public). Arguments have evolved around the validity of the dose response representation that is internationally used for radiation protection purposes, namely the so-called linear-non-threshold (LNT) model. The debate has been masked by the intrinsic randomness of radiation interaction at the cellular level and also by gaps in the relevant scientific knowledge on the development and expression of health effects. There has also been a vague use, abuse, and misuse of radiation-related risk concepts and quantities and their associated uncertainties. As a result, there is some ambiguity in the interpretation of the phenomena and a general lack of awareness of the implications for a number of risk-causation qualities, namely its attributes and characteristics. In particular, the LNT model has been used not only for protection purposes but also for blindly attributing actual effects to specific exposure situations. The latter has been discouraged as being a misuse of the model, but the supposed incorrectness has not been clearly proven. The paper will endeavour to demonstrate unambiguously the following thesis in relation to health effects due to low radiation doses: (i) Their existence is highly plausible. A number of epidemiological statistical assessments of sufficiently large exposed populations show that, under certain conditions, the prevalence of the effects increases with dose. From these assessments, it can be hypothesized that the occurrence of the effects at any dose, however small, appears decidedly worthy of belief. While strictly the evidence does not allow to conclude that a threshold dose level does not exist either In fact, a formal quantitative uncertainty analysis, combining the different uncertain components of estimated radiation-related risk, with and

  19. Dexamethasone, all trans retinoic acid and interferon alpha 2a in patients with refractory multiple myeloma.

    Science.gov (United States)

    Avilés, A; Rosas, A; Huerta-Guzmán, J; Talavera, A; Cleto, S

    1999-02-01

    Few effective regimen are available for patients with refractory multiple myeloma (RMM). Generally, responses are scarce and disease free survival is very short. We developed a new therapeutic option in these patients using dexamethasone (40 mg/m2, i.v., daily, days 1 to 4), all-trans retinoic acid (45 mg/m2, po, daily, days 5 to 14) and interferon alpha 2a (9.0 MU, daily, subcutaneously, days 5 to 14). The treatment was administered every 21 days for 6 cycles. In a pilot study, 12 patients, heavily treated with chemotherapy and radiotherapy and in some cases with interferon, were allocated to receive the afore mentioned treatment. Response was observed in 10 patients (83%). With a median follow-up of 36.1 months (range 27 to 41), seven patients remain alive and disease-free without any treatment. Two patients were failures and have died due to tumor progression. Toxicity was mild and all patients received treatment according to the planned doses of drugs. The use of biological modifiers in combination with dexamethasone offer a safe and effective therapeutic option in patients with refractory multiple myeloma. More studies are warranted to define the role of this type of treatment.

  20. Emphysema quantification on low-dose CT using percentage of low-attenuation volume and size distribution of low-attenuation lung regions: Effects of adaptive iterative dose reduction using 3D processing

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, Mizuho, E-mail: nmizuho@med.kobe-u.ac.jp [Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Matsumoto, Sumiaki, E-mail: sumatsu@med.kobe-u.ac.jp [Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Seki, Shinichiro, E-mail: sshin@med.kobe-u.ac.jp [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Koyama, Hisanobu, E-mail: hkoyama@med.kobe-u.ac.jp [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Fujisawa, Yasuko, E-mail: yasuko1.fujisawa@toshiba.co.jp [Toshiba Medical Systems Corporation, 1385 Shimoishigami, Otawara, Tochigi 324-8550 (Japan); Sugihara, Naoki, E-mail: naoki.sugihara@toshiba.co.jp [Toshiba Medical Systems Corporation, 1385 Shimoishigami, Otawara, Tochigi 324-8550 (Japan); and others

    2014-12-15

    Highlights: • Emphysema quantification (LAV% and D) was affected by image noise on low-dose CT. • For LAV% and D, AIDR 3D improved agreement of quantification on low-dose CT. • AIDR 3D has the potential to quantify emphysema accurately on low-dose CT. - Abstract: Purpose: To evaluate the effects of adaptive iterative dose reduction using 3D processing (AIDR 3D) for quantification of two measures of emphysema: percentage of low-attenuation volume (LAV%) and size distribution of low-attenuation lung regions. Method and materials: : Fifty-two patients who underwent standard-dose (SDCT) and low-dose CT (LDCT) were included. SDCT without AIDR 3D, LDCT without AIDR 3D, and LDCT with AIDR 3D were used for emphysema quantification. First, LAV% was computed at 10 thresholds from −990 to −900 HU. Next, at the same thresholds, linear regression on a log–log plot was used to compute the power law exponent (D) for the cumulative frequency-size distribution of low-attenuation lung regions. Bland–Altman analysis was used to assess whether AIDR 3D improved agreement between LDCT and SDCT for emphysema quantification of LAV% and D. Results: The mean relative differences in LAV% between LDCT without AIDR 3D and SDCT were 3.73%–88.18% and between LDCT with AIDR 3D and SDCT were −6.61% to 0.406%. The mean relative differences in D between LDCT without AIDR 3D and SDCT were 8.22%–19.11% and between LDCT with AIDR 3D and SDCT were 1.82%–4.79%. AIDR 3D improved agreement between LDCT and SDCT at thresholds from −930 to −990 HU for LAV% and at all thresholds for D. Conclusion: AIDR 3D improved the consistency between LDCT and SDCT for emphysema quantification of LAV% and D.

  1. Genetic Factors Affecting Susceptibility to Low Dose & Low Dose-Rate Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bedford, Joel

    2014-04-18

    Our laboratory has, among other things, developed and used the gamma H2AX focus assay and other chromosomal and cell killing assays to show that differences in this DNA double strand break (dsb) related response can be clearly and distinctly demonstrated for cells which are mildly hyper-radiosensitive such as those associated with A-T heterozygosity. We have found this level of mild hypersensitivity for cells from some 20 to 30 % of apparently normal individuals and from apparently normal parents of Retinoblastoma patients. We found significant differences in gene expression in somatic cells from unaffected parents of Rb patients as compared with normal controls, suggesting that these parents may harbor some as yet unidentified genetic abnormality. In other experiments we sought to determine the extent of differences in normal human cellular reaponses to radiation depending on their irradiation in 2D monolayer vs 3D organized acinar growth conditions. We exmined cell reproductive death, chromosomal aberration induction, and the levels of γ-H2AX foci in cells after single acute gamma-ray doses and immediately after 20 hours of irradiation at a dose rate of 0.0017 Gy/min. We found no significant differences in the dose-responses of these cells under the 2D or 3D growth conditions. While this does not mean such differences cannot occur in other situations, it does mean that they do not generally or necessarily occur. In another series of studies in collaboration with Dr Chuan Li, with supprt from this current grant. We reported a role for apoptotic cell death in promoting wound healing and tissue regeneration in mice. Apoptotic cells released growth signals that stimulated the proliferation of progenitor or stem cells. In yet another collaboration with Dr, B. Chen with funds from this grant, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase

  2. Low-dose add-back therapy during postoperative GnRH agonist treatment

    Directory of Open Access Journals (Sweden)

    Hsiao-Wen Tsai

    2016-02-01

    Conclusion: Low dose add-back therapy could effectively ameliorate hypoestrogenic side effects and simultaneously maintain the therapeutic response of GnRH agonist treatment. The treatment dropout was lower compared with a regular dose. Therefore, low dose add-back therapy can be considered a treatment choice during postoperative GnRH agonist treatment.

  3. Low-dose radiation attenuates chemical mutagenesis in vivo. Cross adaptation

    International Nuclear Information System (INIS)

    Kakinuma, Shizuko; Yamauchi, Kazumi; Amasaki, Yoshiko; Nishimura, Mayumi; Shimada, Yoshiya

    2009-01-01

    The biological effects of low-dose radiation are not only of social concern but also of scientific interest. The radioadaptive response, which is defined as an increased radioresistance by prior exposure to low-dose radiation, has been extensively studied both in vitro and in vivo. Here we briefly review the radioadaptive response with respect to mutagenesis, survival rate, and carcinogenesis in vivo, and introduce our recent findings of cross adaptation in mouse thymic cells, that is, the suppressive effect of repeated low-dose radiation on mutation induction by the alkylating agent N-ethyl-N-nitrosourea. (author)

  4. Simultaneous Determination of Ciprofloxacin Hydrochloride and Dexamethasone Sodium Phosphate in Eye Drops by HPLC

    Directory of Open Access Journals (Sweden)

    Prakash Katakam

    2012-01-01

    Full Text Available A liquid chromatographic method was developed and validated for the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations. Optimum separation was achieved in less than 5 min using a C18 column (250 mmx4.6 mm i.d, 5μ particle size by isocratic elution. The mobile phase consisting of a mixture of mixed phosphate buffer (pH 4 and acetonitrile (65:35, v/v was used. Column effluents were monitored at 254 nm at a flow rate of 1ml/min. Retention times of ciprofloxacin hydrochloride and dexamethasone sodium phosphate were 2.0 and 3.16 min respectively. The linearity of ciprofloxacin hydrochloride and dexamethasone sodium phosphate was in the range of 3-18 μg/ml and 1-6 μg/ml respectively. Developed method was economical in terms of the time taken and amount of solvent consumed for each analysis. The method was validated and successfully applied to the simultaneous determination of ciprofloxacin hydrochloride and dexamethasone sodium phosphate in bulk and pharmaceutical formulations.

  5. Effect of low dose ionizing radiation upon concentration of

    International Nuclear Information System (INIS)

    Viliae, M.; Kraljeviae, P.; Simpraga, M.; Miljaniae, S.

    2004-01-01

    It is known that low dose ionizing radiation might have stimulating effects (Luckey, 1982, Kraljeviae, 1988). This fact has also been confirmed in the previous papers of Kraljeviae et al. (2000-2000a; 2001). Namely, those authors showed that irradiation of chicken eggs before incubation by a low dose of 0.15 Gy gamma radiation increases the activity aspartateaminotrasferases (AST) and alanine-aminotransferases (ALT) in blood plasma of chickens hatched from irradiated eggs, as well as growth of chickens during the fattening period. Low doses might also cause changes in the concentration of some biochemical parameters in blood plasma of the same chickens such as changes in the concentration of total proteins, glucose and cholesterol. In this paper, an attempt was made to investigate the effects of low dose gamma radiation upon the concentration of sodium and potassium in the blood plasma of chickens which were hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy. Obtained results were compared with the results from the control group (chickens hatched from nonirradiated eggs). After hatching, all other conditions were the same for both groups. Blood samples were drawn from heart, and later from the wing vein on days 1, 3, 5, 7, 10, 20, 30 and 42. The concentration of sodium and potassium was determined spectrophotometrically by atomic absorbing spectrophotometer Perkin-Elmer 1100B. The concentration of sodium and potassium in blood plasma of chickens hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy indicated a statistically significant increase (P>0.01) only on the first day of the experiment. Obtained results showed that irradiation of eggs on the 19th day of incubation by dose of 0.15 Gy gamma radiation could have effects upon the metabolism of electrolytes in chickens. (Author)

  6. Physics and quality assurance for brachytherapy - Part II: Low dose rate and pulsed dose rate

    International Nuclear Information System (INIS)

    Williamson, Jeffrey F.

    1997-01-01

    Purpose: A number of recent developments have revitalized brachytherapy including remote afterloading, implant optimization, increasing use of 3D imaging, and advances in dose specification and basic dosimetry. However, the core physical principles underlying the classical methods of dose calculation and arrangement of multiple sources remain unchanged. The purpose of this course is to review these principles and their applications to low dose-rate interstitial and intracavitary brachytherapy. Emphasis will be placed upon the classical implant systems along with classical and modern methods of dose specification. The level of presentation is designed for radiation oncology residents and beginning clinical physicists. A. Basic Principles (1) Radium-substitute vs. low-energy sealed sources (2) Dose calculation principles (3) The mysteries of source strength specification revealed: mgRaEq, mCi and air-kerma strength B. Interstitial Brachytherapy (1) Target volume, implanted volume, dose specification in implants and implant optimization criteria (2) Classical implant systems: Manchester Quimby and Paris a) Application of the Manchester system to modern brachytherapy b) Comparison of classical systems (3) Permanent interstitial implants a) Photon energy and half life b) Dose specification and pre-operative planning (4) The alphabet soup of dose specification: MCD (mean central dose), minimum dose, MPD (matched peripheral dose), MPD' (minimum peripheral dose) and DVH (dose-volume histogram) quality indices C. Intracavitary Brachytherapy for Carcinoma of the Cervix (1) Basic principles a) Manchester System: historical foundation of U.S. practice patterns b) Principles of applicator design (2) Dose specification and treatment prescription a) mg-hrs, reference points, ICRU Report 38 reference volume -- Point A dose vs mg-hrs and IRAK (Integrated Reference Air Kerma) -- Tissue volume treated vs mg-hrs and IRAK b) Practical methods of treatment specification and prescription

  7. Physics and quality assurance for brachytherapy - Part II: Low dose rate and pulsed dose rate

    International Nuclear Information System (INIS)

    Williamson, Jeffrey F.

    1996-01-01

    Purpose: A number of recent developments have revitalized brachytherapy including remote afterloading, implant optimization, increasing use of 3D imaging, and advances in dose specification and basic dosimetry. However, the core physical principles underlying the classical methods of dose calculation and arrangement of multiple sources remain unchanged. The purpose of this course is to review these principles and their applications to low dose-rate interstitial and intracavitary brachytherapy. Emphasis will be placed upon the classical implant systems along with classical and modern methods of dose specification. The level of presentation is designed for radiation oncology residents and beginning clinical physicists. A. Basic Principles (1) Radium-substitute vs. low-energy sealed sources (2) Dose calculation principles (3) The mysteries of source strength specification revealed: mgRaEq, mCi and air-kerma strength B. Interstitial Brachytherapy (1) Target volume, implanted volume, dose specification in implants and implant optimization criteria (2) Classical implant systems: Manchester Quimby and Paris a) Application of the Manchester system to modern brachytherapy b) Comparison of classical systems (3) Permanent interstitial implants a) Photon energy and half life b) Dose specification and pre-operative planning (4) The alphabet soup of dose specification: MCD (mean central dose), minimum dose, MPD (matched peripheral dose), MPD' (minimum peripheral dose) and DVH (dose-volume histogram) quality indices C. Intracavitary Brachytherapy for Carcinoma of the Cervix (1) Basic principles a) Manchester System: historical foundation of U.S. practice patterns b) Principles of applicator design (2) Dose specification and treatment prescription a) mg-hrs, reference points, ICRU Report 38 reference volume --Point A dose vs mg-hrs and IRAK (Integrated Reference Air Kerma) --Tissue volume treated vs mg-hrs and IRAK b) Practical methods of treatment specification and prescription

  8. Clinical application of low-dose spiral CT for orthodontics

    International Nuclear Information System (INIS)

    Xie Na; Gan Yungen; Shu Huang; Lin FeiFei; Li Zhiyong; Sun Jie

    2009-01-01

    Objective: To determine the effect of reducing the value of mA or kV on the image quality and the radiation dose of the patients undergoing low-dose spiral CT for orthodontics. Methods: Thirty patients were divided into three groups, each group has 10 patients. They were group 1 (80 kV and 200 mA), group 2 (120 kV and 80 mA), group 3 (120 kV and 200 mA) The volume CT dose index (CTDI) was recorded and the average dose-length produce (DLP) was calculated in three groups,respectively. Image quality of three groups were compared and scored by two radiologists, and the results were statistically analysed. Results: The CTDI and DLP of 80 kV group (group 2) were 8.7 mGy and (36.80 ± 3.60) mGy · cm, respectively, those of 80 mA group (group 3) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively, and those of conventional-dose group (group 1) were 19.6 mGy and (82.14 ± 7.18) mGy · cm, respectively. There was no significant difference among three groups in diagnostic image quality. Conclusions: Low-dose spiral CT for orthodontics, especially the low-kV scan, may decrease the radiation exposure and guarantee the image quality. (authors)

  9. Implication of new CEC recommendations for individual monitoring for external radiation doses to the skin and the extremities

    DEFF Research Database (Denmark)

    Christensen, P.; Julius, H.W.; Marshall, T.O.

    1991-01-01

    A drafting group consisting of the above authors has assisted the CEC in revising the CEC document Technical Recommendations for Monitoring the Exposure to Individuals to External Radiation, EUR 5287, published in 1975. The paper highlights sections of the revised version relating particularly...... to irradiation of the skin and the extremities and focusses on problems connected to exposure to weakly penetrating radiations. Concepts of individual monitoring for external radiation exposures to the skin of the whole body and to the extremities are discussed and guidance is given as regards dose quantities...

  10. β–Hydroxy β–Methylbutyrate Improves Dexamethasone-Induced Muscle Atrophy by Modulating the Muscle Degradation Pathway in SD Rat

    Science.gov (United States)

    Choi, Yeon Ja; Park, Min Hi; Jang, Eun Ji; Park, Chan Hum; Yoon, Changshin; Kim, Nam Deuk; Kim, Mi Kyung; Chung, Hae Young

    2014-01-01

    Skeletal muscle atrophy results from various conditions including high levels of glucocorticoids, and β–hydroxy β–methylbutyrate (HMB; a metabolite of leucine) is a potent therapeutical supplement used to treat various muscle disorders. Recent studies have demonstrated that HMB inhibits dexamethasone-induced atrophy in cultured myotubes, but its effect on dexamethasone-induced muscle atrophy has not been determined in vivo. In the present study, we investigated the effect of HMB on dexamethasone-induced muscle atrophy in rats. Treatment with dexamethasone weakened grip strengths and increased muscle damage as determined by increased serum creatine kinase levels and by histological analysis. Dexamethasone treatment also reduced both soleus and gastrocnemius muscle masses. However, HMB supplementation significantly prevented reductions in grip strengths, reduced muscle damage, and prevented muscle mass and protein concentration decrease in soleus muscle. Biochemical analysis demonstrated that dexamethasone markedly increased levels of MuRF1 protein, which causes the ubiquitination and degradation of MyHC. Indeed, dexamethasone treatment decreased MyHC protein expression and increased the ubiquitinated-MyHC to MyHC ratio. However, HMB supplementation caused the down-regulations of MuRF1 protein and of ubiquitinated-MyHC. Furthermore, additional experiments provided evidence that HMB supplementation inhibited the nuclear translocation of FOXO1 induced by dexamethasone, and showed increased MyoD expression in the nuclear fractions of soleus muscles. These findings suggest that HMB supplementation attenuates dexamethasone-induced muscle wasting by regulating FOXO1 transcription factor and subsequent MuRF1 expression. Accordingly, our results suggest that HMB supplementation could be used to prevent steroid myopathy. PMID:25032690

  11. Low dose versus high dose anti-snake venom therapy in the treatment of haematotoxic snake bite in South India.

    Science.gov (United States)

    Joseph, Imanto M; Kuriakose, Cijoy K; Dev, Anand Vimal; Philip, George A

    2017-10-01

    Most of the studies on the appropriate dose of anti-snake venom (ASV) are from tertiary hospitals and the guidelines are unclear. Our observational study compared the outcomes of two prevalent treatment regimes for haematotoxic snake bite in a secondary care hospital in South India. The time to normalisation of whole blood clotting time, mortality and complications were not different between the groups. The average dose of ASV required in the low and high dose groups were 106 mL and 246 mL, respectively. Consequently, patients who received low dose ASV incurred approximately 50% less expense. Urticarial rashes were also significantly fewer in the low dose group.

  12. Comparison of granisetron alone and granisetron plus dexamethasone in the prophylaxis of cytotoxic-induced emesis.

    Science.gov (United States)

    Carmichael, J.; Bessell, E. M.; Harris, A. L.; Hutcheon, A. W.; Dawes, P. J.; Daniels, S.; Bessel, E. M.

    1994-01-01

    Two hundred and seventy-eight adult chemonaive patients, receiving moderately emetogenic chemotherapy were randomly allocated to receive either intravenous (i.v.) granisetron 3 mg plus i.v. dexamethasone 8 mg or i.v. granisetron 3 mg plus i.v. placebo dexamethasone prior to chemotherapy. Eight-two per cent of all patients recruited were female, and 91% of all patients consumed less than 10 units of alcohol per week, suggesting a study population with an increased risk of nausea and vomiting. In the first 24 h 85% of patients who received granisetron plus dexamethasone were complete responders compared with 75.9% of the patients receiving granisetron alone (P = 0.053). There were statistically significant improvements in complete response over 7 days (P = 0.029) and in the numbers of patients receiving rescue antiemetic (P = 0.0004). Toxicity was minimal with no significant differences between treatment groups. These results confirm the antiemetic activity of granisetron and show that it has an additive effect in combination with dexamethasone. PMID:7981069

  13. Dexamethasone-induced radioresistance occurring independent of human papilloma virus gene expression in cervical carcinoma cells

    International Nuclear Information System (INIS)

    Rutz, H.P.; Mariotta, M.; Mirimanoff, R.O.; Knebel Doeberitz, M. von

    1998-01-01

    The aim of this study was to investigate the role of HPV 18 E6 and E7 gene products with respect to radiosensitivity of two cervical carcinoma cell lines. The two cervical carcinoma lines C4-1 and SW 756 were used in which treatment with dexamethasone allows to modulate expression levels of HPV 18 E6 and E7 genes: Upregulation in C4-1, down-regulation in SW 756. Effects of treatment with dexamethasone on plating efficiency and radiosensitivity were assessed using a clonogenic assay. Treatment with dexamethasone increased plating efficiency of the C4-1 cells, but did not affect plating efficiency of SW 756 cells. Treatment with dexamethasone induced enhanced radioresistance in both cell lines. Thus, in C4-1 cells the observed changes in radioresistance correlate to the enhancement in expression of HPV 18 genes E6/E7, whereas in SW 756, a reduced expression correlates negatively with the enhanced radioresistance. (orig./MG) [de

  14. A clinical comparison of high dose and low dose of Suxamethonium

    Directory of Open Access Journals (Sweden)

    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

  15. A case of gait disturbance caused by low-dose gabapentin

    Science.gov (United States)

    Kanao-Kanda, Megumi; Kanda, Hirotsugu; Takahata, Osamu; Kunisawa, Takayuki

    2016-01-01

    Gabapentin, an anticonvulsant agent, is now often used for the treatment of neuropathic pain all over the world. It is unclear whether the combined use of gabapentin, sodium valproate, and flunitrazepam results in enhancement of the side effect, a gait disturbance. A 60-year-old man was taking oral sodium valproate for symptomatic epilepsy after a brain contusion and flunitrazepam to relieve insomnia. Oral gabapentin therapy was started for suspected neuropathic pain. Although the initial dose of oral gabapentin (200 mg) relieved the pain, the lower extremities became weak, resulting in a gait disturbance. The therapy was restarted with a halved dose, and this resolved the gait disturbance and relieved the pain. PMID:27354808

  16. Bioassay in BALB/c mice exposed to low dose rate radiation

    Energy Technology Data Exchange (ETDEWEB)

    Km, Sung Dae; Gong, Eun Ji; Bae, Min Ji; Yang, Kwang Mo; Kim, Joong Sun [Dongnam Institute of Radiological and Medical Sciences, Suwon (Korea, Republic of)

    2012-09-15

    The present study was performed to investigate the toxicity of low-dose-rate irradiation in BALB/c mice. Twenty mice of each sex were randomly assigned to four groups of five mice each and were exposed to 0 (sham), 0.02, 0.2, or 2 Gy, equivalents to low-dose-rate irradiation to 3.49 mGy{center_dot}h{sup -1}. Urine, blood, and blood biochemistry were analyzed, and organ weight was measured. The low-dose-rate irradiation did not induce any toxicologically significant changes in mortality, clinical signs, body weight, food and water consumption, urinalysis, and serum biochemistry. However, the weights of reproductive organs including the testis, ovary, and uterus decreased in a dose-dependent manner. Irradiation at 2 Gy significantly decreased the testis, ovary, and uterus weights, but did not change the weights of other organs. There were no adverse effects on hematology in any irradiated group and only the number of neutrophils increased dose dependently. The low-dose-rate irradiation exposure did not cause adverse effects in mice at dose levels of 2 Gy or less, but the reproductive systems of male and female mice showed toxic effects.

  17. Dexamethasone-induced radioresistance occurring independent of human papilloma virus gene expression in cervical carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Rutz, H.P.; Mariotta, M.; Mirimanoff, R.O. [Lab. de Radiobiologie, Service de Radio-Oncologie, CHUV, Lausanne (Switzerland); Knebel Doeberitz, M. von [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Inst. fuer Virusforschung

    1998-02-01

    The aim of this study was to investigate the role of HPV 18 E6 and E7 gene products with respect to radiosensitivity of two cervical carcinoma cell lines. The two cervical carcinoma lines C4-1 and SW 756 were used in which treatment with dexamethasone allows to modulate expression levels of HPV 18 E6 and E7 genes: Upregulation in C4-1, down-regulation in SW 756. Effects of treatment with dexamethasone on plating efficiency and radiosensitivity were assessed using a clonogenic assay. Treatment with dexamethasone increased plating efficiency of the C4-1 cells, but did not affect plating efficiency of SW 756 cells. Treatment with dexamethasone induced enhanced radioresistance in both cell lines. Thus, in C4-1 cells the observed changes in radioresistance correlate to the enhancement in expression of HPV 18 genes E6/E7, whereas in SW 756, a reduced expression correlates negatively with the enhanced radioresistance. (orig./MG) [Deutsch] Das Ziel dieser Studie lag darin, die Rolle der HPV-18-Gene E6 und E7 in bezug auf die Strahlenempfindlichkeit von menschlichen Zervixkarzinomzellen zu untersuchen. Wir verwendeten zwei menschliche Zervixkarzinomzellinien, C4-1 und SW 756, in welchen die Expression der viralen Gene HPV 18 E6 und E7 mit Dexamethason moduliert werden kann: In C4-1 bewirkt die Behandlung mit Dexamethason eine Erhoehung der Expression dieser Gene, in SW 756 eine Verminderung. Die Wirkung auf die Wachstumsfaehigkeit der Zellen und auf die Wachstumshemmung durch die Bestrahlung wurde unter Verwendung eines klonogenen Assays bestimmt. Dexamethason bewirkte eine erhoehte Wachstumsfaehigkeit der C4-1 Zellen, ohne die Wachstumsfaehigkeit der SW-756-Zellen zu beeinflussen, wie schon frueher beschrieben. Die Resistenz beider Zellinien gegenueber Bestrahlung wurde erhoeht. Somit besteht in den C4-1-Zellen eine Korrelation der Expression der viralen Gene mit der Zunahme der Strahlenresistenz, wogegen in den SW-756-Zellen die Abnahme der Expression im Gegensatz zu

  18. Magnetic hyaluronic acid nanospheres via aqueous Diels-Alder chemistry to deliver dexamethasone for adipose tissue engineering.

    Science.gov (United States)

    Jia, Yang; Fan, Ming; Chen, Huinan; Miao, Yuting; Xing, Lian; Jiang, Bohong; Cheng, Qifan; Liu, Dongwei; Bao, Weikang; Qian, Bin; Wang, Jionglu; Xing, Xiaodong; Tan, Huaping; Ling, Zhonghua; Chen, Yong

    2015-11-15

    Biopolymer-based nanospheres have great potential in the field of drug delivery and tissue regenerative medicine. In this work, we present a flexible way to conjugate a magnetic hyaluronic acid (HA) nanosphere system that are capable of vectoring delivery of adipogenic factor, e.g. dexamethasone, for adipose tissue engineering. Conjugation of nanospheres was established by aqueous Diels-Alder chemistry between furan and maleimide of HA derivatives. Simultaneously, a furan functionalized dexamethasone peptide, GQPGK, was synthesized and covalently immobilized into the nanospheres. The magnetic HA nanospheres were fabricated by encapsulating super-paramagnetic iron oxide nanoparticles, which exhibited quick magnetic sensitivity. The aqueous Diels-Alder chemistry made nanospheres high binding efficiency of dexamethasone, and the vectoring delivery of dexamethasone could be easily controlled by a external magnetic field. The potential application of the magnetic HA nanospheres on vectoring delivery of adipogenic factor was confirmed by co-culture of human adipose-derived stem cells (ASCs). In vitro cytotoxicity tests demonstrated that incorporation of dexamethasone into magnetic HA nanospheres showed high efficiency to promote ASCs viabilities, in particular under a magnetic field, which suggested a promising future for adipose regeneration applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Delivery of the extremely low-birth- weight vertex-presenting baby ...

    African Journals Online (AJOL)

    2010-12-02

    Dec 2, 2010 ... rise in the caesarean section rate.1 This rise has been disproportionate to ... a possible extremely low-birth-weight infant the risks of mortality and short- and .... the US Health Statistics data from 1999 to 2000 using multivariate ...

  20. Extremely low-frequency magnetic fields and risk of childhood leukemia

    DEFF Research Database (Denmark)

    Schüz, Joachim; Dasenbrock, Clemens; Ravazzani, Paolo

    2016-01-01

    Exposure to extremely low-frequency magnetic fields (ELF-MF) was evaluated in an International Agency for Research on Cancer (IARC) Monographs as "possibly carcinogenic to humans" in 2001, based on increased childhood leukemia risk observed in epidemiological studies. We conducted a hazard assess...

  1. Development of microcontroller based instrumentation for low dose implantation

    International Nuclear Information System (INIS)

    Suresh, K.; Saravanan, K.; Panigrahi, B.K.; Nair, K.G.M.

    2011-01-01

    In experiments like ion implantation based ion track formations, the sample is implanted to low doses of the order of 10 10 ions/cm 2 , limiting the ion beam currents to be less than 1-5 x 10 -12 A. However the standard current integrators available are not sensitive to very low currents, causing an unacceptable high level of error in dose measurement. Hence a low dose implantation measurement system has been developed. It consists of a very sensitive low current preamplifier with full scale input 1nA/100pA, a standard current integrator, a microcontroller based interface circuit, which are connected to a personal computer(PC) through USB. Two types of the software are developed for the system: the microcontroller firmware using C and windows based virtual instrument programs using LabVIEW 7.0. Necessary precautions associated with pA level measurement like rigidly fastened good quality cables, low ripple DC power supply, shielding, close mounting of the preamplifier to the sample are adopted. After necessary calibrations with an ECIL make low current source, the system has been put into regular use. Design and development details, salient features are discussed in this paper. (author)

  2. Silencing Dkk1 expression rescues dexamethasone-induced suppression of primary human osteoblast differentiation.

    LENUS (Irish Health Repository)

    Butler, Joseph S

    2010-09-01

    The Wnt\\/β-catenin pathway is a major signaling cascade in bone biology, playing a key role in bone development and remodeling. The objectives of this study were firstly, to determine the effects of dexamethasone exposure on Wnt\\/β-catenin signaling at an intracellular and transcriptional level, and secondly, to assess the phenotypic effects of silencing the Wnt antagonist, Dickkopf-1 (Dkk1) in the setting of dexamethasone exposure.

  3. Effects of low-dose recombinant human erythropoietin treatment on cognitive performance

    DEFF Research Database (Denmark)

    Viuff, Søren Lundgaard; Plenge, Ulla; Belhage, Bo

    2017-01-01

    , NUFI or self-reported results between the groups. CONCLUSIONS: In this small study, we found no significant effect of low-dose or micro-dose rhEpo on visual attention, cognitive performance in complex cognitive tasks or self-experienced cognitive performance compared with placebo. FUNDING: The Aase......INTRODUCTION: High-dose recombinant human erythropoietin (rhEpo) has been shown to improve cognitive performance in both healthy volunteers and in patients suffering from diseases affecting the brain. The aim of this study was to examine whether administration of low-dose and even micro-dose rh...

  4. Effects of low-dose recombinant human erythropoietin treatment on cognitive performance

    DEFF Research Database (Denmark)

    Viuff, Søren Lundgaard; Plenge, Ulla; Belhage, Bo

    2017-01-01

    -reported results between the groups. Conclusions: In this small study, we found no significant effect of low-dose or micro-dose rhEpo on visual attention, cognitive performance in complex cognitive tasks or self-experienced cognitive performance compared with placebo. Funding: The Aase and Ejnar Danielsen......Introduction: High-dose recombinant human erythropoietin (rhEpo) has been shown to improve cognitive performance in both healthy volunteers and in patients suffering from diseases affecting the brain. The aim of this study was to examine whether administration of low-dose and even micro-dose rh...

  5. Bibliometrics analysis of the PubMed literatures on low-dose CT

    International Nuclear Information System (INIS)

    Wang Qian; Xia Guanghui; Ma Xiaohong; Zhao Xinming

    2012-01-01

    Objective: The purposes of this study were to evaluate the developmental rule and feature in low-dose CT examinations and to provide useful references for study in the future. Materials and Methods: The journal articles on PubMed from 2002 to 2011 were processed by Thomson Data Analyzer and five aspects were analysed: time, authors, institutions, journals, countries, and keywords. Results: The number of journal articles in low-dose CT examinations were 6 433, 3165 were from US (49.2%), 112 from China (1.4%); 3664 authors (80.42%) published only one article, the famous authors published more than 4 articles; there were 9 core journals in this area. In the last decade, the number and quality of the journal articles in low -dose CT have been dramatically increased. Conclusion: The interest on the low -dose CT examination has been steadily increasing, and world famous research teams have been established. The research in low-dose CT is a multi-discipline involving medicine, medical physics, and mathematics. Cooperation between multiple scientific domains is needed for the future studies. (authors)

  6. Mechanisms of Enhanced Cell Killing at Low Doses: Implications for Radiation Risk

    International Nuclear Information System (INIS)

    Johnston, Peter J.; Wilson, George D.

    2003-01-01

    We have shown that cell lethality actually measured after exposure to low-doses of low-LET radiation, is markedly enhanced relative to the cell lethality previously expected by extrapolation of the high-dose cell-killing response. Net cancer risk is a balance between cell transformation and cell kill and such enhanced lethality may more than compensate for transformation at low radiation doses over a least the first 10 cGy of low-LET exposure. This would lead to a non-linear, threshold, dose-risk relationship. Therefore our data imply the possibility that the adverse effects of small radiation doses (<10 cGy) could be overestimated in specific cases. It is now important to research the mechanisms underlying the phenomenon of low-dose hypersensitivity to cell killing, in order to determine whether this can be generalized to safely allow an increase in radiation exposure limits. This would have major cost-reduction implications for the whole EM program

  7. Dexamethasone impairs hypoxia-inducible factor-1 function

    International Nuclear Information System (INIS)

    Wagner, A.E.; Huck, G.; Stiehl, D.P.; Jelkmann, W.; Hellwig-Buergel, T.

    2008-01-01

    Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription-factor composed of α- and β-subunits. HIF-1 is not only necessary for the cellular adaptation to hypoxia, but it is also involved in inflammatory processes and wound healing. Glucocorticoids (GC) are therapeutically used to suppress inflammatory responses. Herein, we investigated whether GC modulate HIF-1 function using GC receptor (GR) possessing (HepG2) and GR deficient (Hep3B) human hepatoma cell cultures as model systems. Dexamethasone (DEX) treatment increased HIF-1α levels in the cytosol of HepG2 cells, while nuclear HIF-1α levels and HIF-1 DNA-binding was reduced. In addition, DEX dose-dependently lowered the hypoxia-induced luciferase activity in a reporter gene system. DEX suppressed the hypoxic stimulation of the expression of the HIF-1 target gene VEGF (vascular endothelial growth factor) in HepG2 cultures. DEX did not reduce hypoxically induced luciferase activity in HRB5 cells, a Hep3B derivative lacking GR. Transient expression of the GR in HRB5 cells restored the susceptibility to DEX. Our study discloses the inhibitory action of GC on HIF-1 dependent gene expression, which may be important with respect to the impaired wound healing in DEX-treated patients

  8. Why we need new approaches to low-dose risk modeling

    International Nuclear Information System (INIS)

    Alvarez, J.L.; Seiler, F.A.

    1996-01-01

    The linear no-threshold model for radiation effects was introduced as a conservative model for the design of radiation protection programs. The model has persisted not only as the basis for such programs, but has come to be treated as a dogma and is often confused with scientific fact. In this examination a number of serious problems with the linear no-threshold model of radiation carcinogenesis were demonstrated, many of them invalidating the hypothesis. It was shown that the relative risk formalism did not approach 1 as the dose approaches zero. When morality ratios were used instead, the data in the region below 0.3 Sv were systematically below the predictions of the linear model. It was also shown that the data above 0.3 Sv were of little use in formulating a model at low doses. In addition, these data are valid only for doses accumulated at high dose rates, and there is no scientific justification for using the model in low-dose, low-dose-rate extrapolations for purposes of radiation protection. Further examination of model fits to the Japanese survivor data were attempted. Several such models were fit to the data including an unconstrained linear, linear-square root, and Weibull, all of which fit the data better than the relative risk, linear no-threshold model. These fits were used to demonstrate that the linear model systematically over estimates the risk at low doses in the Japanese survivor data set. It is recommended here that an unbiased re-analysis of the data be undertaken and the results used to construct a new model, based on all pertinent data. This model could then form the basis for managing radiation risks in the appropriate regions of dose and dose rate

  9. 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

  10. [Experimental study on avascular necrosis of femoral head in chickens induced by different glucocorticoides].

    Science.gov (United States)

    Xiao, Chun-Sheng; Lin, Na; Lin, Shi-Fu; Wan, Rong; Chen, Wei-Heng

    2010-03-01

    To study the effects of Methylprednisolone and Dexamethasone on the avascular necrosis of femoral head in chickens. Thirty-six chickens were randomly divided into 6 groups (n = 6): control group (group A), Methylprednisolone low dose group (group B), Methylprednisolone large dose group (group C), small dose Dexamethasone and horse serum group (group D), middle dose Dexamethasone and horse serum group (group E), and Dexamethasone large dose group (group F). On the 6th and 12th weeks, blood samples were obtained to determine the level of total cholesterol triglyeride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL). On the 12th week, femoral heads were taken off. Paraffin tissue sections were prepared to detect histopathologic change with hematoxylin and eosin staining. On the 6th week, compared with group A, the level of CHO increased significantly in group C and group F (P < 0.05), and TG increased in group B, C and group E, while HDL decreased in group B, C and group E. On the 12th week, the level of TG and CHO increased in group B, C, E and group F, and HDL decreased in group C, D and group E (P < 0.05). LDL was not detected in most chickens. The ratio of empty lacuna was higher in group C and group E compared with those of the control group (P < 0.05). Methylprednisolone is easier to induce osteonecrosis of femoral head than Dexamethasone. The condition of metabolic disorder in blood may be the basic pathomechanism of steroid-induced necrosis of femoral head.

  11. Incidental renal tumours on low-dose CT lung cancer screening exams.

    Science.gov (United States)

    Pinsky, Paul F; Dunn, Barbara; Gierada, David; Nath, P Hrudaya; Munden, Reginald; Berland, Lincoln; Kramer, Barnett S

    2017-06-01

    Introduction Renal cancer incidence has increased markedly in the United States in recent decades, largely due to incidentally detected tumours from computed tomography imaging. Here, we analyze the potential for low-dose computed tomography lung cancer screening to detect renal cancer. Methods The National Lung Screening Trial randomized subjects to three annual screens with either low-dose computed tomography or chest X-ray. Eligibility criteria included 30 + pack-years, current smoking or quit within 15 years, and age 55-74. Subjects were followed for seven years. Low-dose computed tomography screening forms collected information on lung cancer and non-lung cancer abnormalities, including abnormalities below the diaphragm. A reader study was performed on a sample of National Lung Screening Trial low-dose computed tomography images assessing presence of abnormalities below the diaphragms and abnormalities suspicious for renal cancer. Results There were 26,722 and 26,732 subjects enrolled in the low-dose computed tomography and chest X-ray arms, respectively, and there were 104 and 85 renal cancer cases diagnosed, respectively (relative risk = 1.22, 95% CI: 0.9-1.5). From 75,126 low-dose computed tomography screens, there were 46 renal cancer diagnoses within one year. Abnormalities below the diaphragm rates were 39.1% in screens with renal cancer versus 4.1% in screens without (P cancer cases versus 13% of non-cases had abnormalities below the diaphragms; 55% of cases and 0.8% of non-cases had a finding suspicious for renal cancer (P cancers. The benefits to harms tradeoff of incidental detection of renal tumours on low-dose computed tomography is unknown.

  12. The biological effects of low doses of radiation: medical, biological and ecological aspects

    International Nuclear Information System (INIS)

    Gun-Aajav, T.; Ajnai, L.; Manlaijav, G.

    2007-01-01

    Full text: The results of recent studies show that low doses of radiation make many different structural and functional changes in a cell and these changes are preserved for a long time. This phenomenon is called as effects of low doses of radiation in biophysics, radiation biology and radiation medicine. The structural and functional changes depend on doses and this dependence has non-linear and bimodal behaviour. More detail, the radiation effect goes up and reaches its maximum (Low doses maximum) in low doses region, then it goes down and takes its stationary means (there is a negative effect in a few cases). With increases in doses and with further increases it goes up. It is established that low dose's maximum depends on physiological state of a biological object, radiation quality and dose rate. During the experiments another special date was established. This specialty is that many different physical and chemical factors are mutually connected and have synergetic behaviour. At present, researches are concentrating their attention on the following three directions: 1. Direct and indirect interaction of radiation's low doses: 2. Interpretation of its molecular mechanism, regulation of the positive effects and elaboration of ways o removing negative effects: 3. Application of the objective research results into practice. In conclusion the authors mention the current concepts on interpretation of low doses effect mechanism, forward their own views and emphasize the importance of considering low doses effects in researches of environmental radiation pollution, radiation medicine and radiation protection. (author)

  13. The effects of dexamethasone on the Na,K-ATPase activity and pump function of corneal endothelial cells.

    Science.gov (United States)

    Hatou, Shin; Yamada, Masakazu; Mochizuki, Hiroshi; Shiraishi, Atsushi; Joko, Takeshi; Nishida, Teruo

    2009-05-01

    The Na(+)- and K(+)-dependent ATPase (Na,K-ATPase) expressed in the basolateral membrane of corneal endothelial cells plays an important role in the pump function of the corneal endothelium. We investigated the possible role of dexamethasone in the regulation of Na,K-ATPase activity and pump function in corneal endothelial cells. Confluent monolayers of mouse corneal endothelial cells were exposed to dexamethasone. ATPase activity of the cells was evaluated by spectrophotometric measurement of phosphate released from ATP with the use of ammonium molybdate, with Na,K-ATPase activity being defined as the portion of total ATPase activity sensitive to ouabain. Pump function of the cells was measured with the use of an Ussing chamber, with the pump function attributable to Na,K-ATPase activity being defined as the portion of the total short-circuit current sensitive to ouabain. Western blot analysis was examined to measure the expression of the Na,K-ATPase alpha(1)-subunit. Dexamethasone (1 or 10 microM) increased the Na,K-ATPase activity and pump function of the cultured cells. These effects of dexamethasone were blocked by cycloheximide, a protein synthesis inhibitor. Western blot analysis also indicated that dexamethasone increased the expression of the Na,K-ATPase alpha(1)-subunit, whereas it decreased the expression of the phospho-Na,K-ATPase alpha(1)-subunit. Our results suggest that dexamethasone stimulates Na,K-ATPase activity in mouse corneal endothelial cells. The effect of dexamethasone activation in these cells is mediated by Na,K-ATPase synthesis and increase in an enzymatic activity by dephosphorylation of Na,K-ATPase alpha(1)-subunits.

  14. Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Suk Chul [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Lee, Kyung-Mi [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kang, Yu Mi [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Kwanghee [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kim, Cha Soon; Yang, Kwang Hee; Jin, Young-Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Chong Soon [Department of Nuclear Medicine, Haeundae Paik Hospital, Inje University, Busan 612-030 (Korea, Republic of); Kim, Hee Sun, E-mail: hskimdvm@khnp.co.kr [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of)

    2010-07-09

    While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4{sup +} T, CD8{sup +} T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1{alpha}, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-{gamma}. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose {gamma}-radiation, which may be associated with the functional benefits observed in various experimental models.

  15. Effects of Maternal Dexamethasone Exposure During Lactation on ...

    African Journals Online (AJOL)

    olayemitoyin

    examined the effects of lactational dexamethasone exposure on metabolic imbalance and oxidative stress marker in the liver ... control. Basal Fasting Blood Sugar (FBS) was also significantly (p<0.001) higher in the Dex ... Exposure to stress and glucocorticoids hormone ..... Energy expenditure and energy intake during.

  16. Mechanisms of Low Dose Radiation-induced T helper Cell Function

    International Nuclear Information System (INIS)

    Gridley, Daila S.

    2008-01-01

    Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of 'dirty bombs' by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete potent immunostimulatory and immunosuppressive cytokines, some of which are implicated in pathophysiological processes. Furthermore, the photon versus proton comparison was important not only to healthy individuals who may be exposed, but also to patients undergoing radiotherapy, since many medical centers in the United States, as well as worldwide, are now building proton accelerators. The overall hypothesis of this study was that whole-body exposure to low-dose photons (gamma-rays) will alter CD4+ Th cell function. We further proposed that exposure to low-dose proton radiation will induce a different pattern of gene and functional changes compared to

  17. Validation of a low dose simulation technique for computed tomography images.

    Directory of Open Access Journals (Sweden)

    Daniela Muenzel

    Full Text Available PURPOSE: Evaluation of a new software tool for generation of simulated low-dose computed tomography (CT images from an original higher dose scan. MATERIALS AND METHODS: Original CT scan data (100 mAs, 80 mAs, 60 mAs, 40 mAs, 20 mAs, 10 mAs; 100 kV of a swine were acquired (approved by the regional governmental commission for animal protection. Simulations of CT acquisition with a lower dose (simulated 10-80 mAs were calculated using a low-dose simulation algorithm. The simulations were compared to the originals of the same dose level with regard to density values and image noise. Four radiologists assessed the realistic visual appearance of the simulated images. RESULTS: Image characteristics of simulated low dose scans were similar to the originals. Mean overall discrepancy of image noise and CT values was -1.2% (range -9% to 3.2% and -0.2% (range -8.2% to 3.2%, respectively, p>0.05. Confidence intervals of discrepancies ranged between 0.9-10.2 HU (noise and 1.9-13.4 HU (CT values, without significant differences (p>0.05. Subjective observer evaluation of image appearance showed no visually detectable difference. CONCLUSION: Simulated low dose images showed excellent agreement with the originals concerning image noise, CT density values, and subjective assessment of the visual appearance of the simulated images. An authentic low-dose simulation opens up opportunity with regard to staff education, protocol optimization and introduction of new techniques.

  18. Evaluating the patient experience after implantation of a 0.4 mg sustained release dexamethasone intracanalicular insert (Dextenza™): results of a qualitative survey.

    Science.gov (United States)

    Gira, Joseph P; Sampson, Reginald; Silverstein, Steven M; Walters, Thomas R; Metzinger, Jamie Lynne; Talamo, Jonathan H

    2017-01-01

    The purpose of this study is to evaluate the patient experience of sustained release dexamethasone intracanalicular insert (Dextenza™) following cataract surgery as part of a Phase III clinical trial program. This cross-sectional, qualitative evaluation involved individual interviews lasting approximately 45 minutes. Patients from four US investigational study sites who had previously received an insert were enrolled. There were no predesignated end points; this was a qualitative survey seeking a deeper understanding of patient experience. Twenty-five patients were interviewed. Most patients (92%) reported the highest level of satisfaction grade with regard to overall product satisfaction. All patients described the insert as comfortable. Most patients (96%) described their overall experience with the insert as very convenient or extremely convenient. Twenty-two of 23 (96%) participants rated their experience with the insert as "very" or "extremely convenient", compared to previous topical therapy, and 88% of patients stated that if they were to undergo cataract surgery again, they would request the insert. When asked if they would recommend the insert to family members or friends, 92% stated they would. The survey found that 84% of participants would be willing to pay more for the insert than for eye drop therapy. The dexamethasone insert was found by patients to be highly favorable with regard to overall satisfaction, convenience, and comfort. The insert was well received and largely preferred over topical therapy alternatives following surgery. More extensive evaluation of the patient experience is warranted, and future studies should help inform design of the next generation of sustained release drug delivery systems.

  19. Prediction of standard-dose brain PET image by using MRI and low-dose brain [{sup 18}F]FDG PET images

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jiayin [School of Electronics Engineering, Huaihai Institute of Technology, Lianyungang, Jiangsu 222005, China and IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Gao, Yaozong [IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and Department of Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Shi, Feng [IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Lalush, David S. [Joint UNC-NCSU Department of Biomedical Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Lin, Weili [MRI Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States); Shen, Dinggang, E-mail: dgshen@med.unc.edu [IDEA Laboratory, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 and Department of Brain and Cognitive Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2015-09-15

    Purpose: Positron emission tomography (PET) is a nuclear medical imaging technology that produces 3D images reflecting tissue metabolic activity in human body. PET has been widely used in various clinical applications, such as in diagnosis of brain disorders. High-quality PET images play an essential role in diagnosing brain diseases/disorders. In practice, in order to obtain high-quality PET images, a standard-dose radionuclide (tracer) needs to be used and injected into a living body. As a result, it will inevitably increase the patient’s exposure to radiation. One solution to solve this problem is predicting standard-dose PET images using low-dose PET images. As yet, no previous studies with this approach have been reported. Accordingly, in this paper, the authors propose a regression forest based framework for predicting a standard-dose brain [{sup 18}F]FDG PET image by using a low-dose brain [{sup 18}F]FDG PET image and its corresponding magnetic resonance imaging (MRI) image. Methods: The authors employ a regression forest for predicting the standard-dose brain [{sup 18}F]FDG PET image by low-dose brain [{sup 18}F]FDG PET and MRI images. Specifically, the proposed method consists of two main steps. First, based on the segmented brain tissues (i.e., cerebrospinal fluid, gray matter, and white matter) in the MRI image, the authors extract features for each patch in the brain image from both low-dose PET and MRI images to build tissue-specific models that can be used to initially predict standard-dose brain [{sup 18}F]FDG PET images. Second, an iterative refinement strategy, via estimating the predicted image difference, is used to further improve the prediction accuracy. Results: The authors evaluated their algorithm on a brain dataset, consisting of 11 subjects with MRI, low-dose PET, and standard-dose PET images, using leave-one-out cross-validations. The proposed algorithm gives promising results with well-estimated standard-dose brain [{sup 18}F]FDG PET

  20. Prediction of standard-dose brain PET image by using MRI and low-dose brain ["1"8F]FDG PET images

    International Nuclear Information System (INIS)

    Kang, Jiayin; Gao, Yaozong; Shi, Feng; Lalush, David S.; Lin, Weili; Shen, Dinggang

    2015-01-01

    Purpose: Positron emission tomography (PET) is a nuclear medical imaging technology that produces 3D images reflecting tissue metabolic activity in human body. PET has been widely used in various clinical applications, such as in diagnosis of brain disorders. High-quality PET images play an essential role in diagnosing brain diseases/disorders. In practice, in order to obtain high-quality PET images, a standard-dose radionuclide (tracer) needs to be used and injected into a living body. As a result, it will inevitably increase the patient’s exposure to radiation. One solution to solve this problem is predicting standard-dose PET images using low-dose PET images. As yet, no previous studies with this approach have been reported. Accordingly, in this paper, the authors propose a regression forest based framework for predicting a standard-dose brain ["1"8F]FDG PET image by using a low-dose brain ["1"8F]FDG PET image and its corresponding magnetic resonance imaging (MRI) image. Methods: The authors employ a regression forest for predicting the standard-dose brain ["1"8F]FDG PET image by low-dose brain ["1"8F]FDG PET and MRI images. Specifically, the proposed method consists of two main steps. First, based on the segmented brain tissues (i.e., cerebrospinal fluid, gray matter, and white matter) in the MRI image, the authors extract features for each patch in the brain image from both low-dose PET and MRI images to build tissue-specific models that can be used to initially predict standard-dose brain ["1"8F]FDG PET images. Second, an iterative refinement strategy, via estimating the predicted image difference, is used to further improve the prediction accuracy. Results: The authors evaluated their algorithm on a brain dataset, consisting of 11 subjects with MRI, low-dose PET, and standard-dose PET images, using leave-one-out cross-validations. The proposed algorithm gives promising results with well-estimated standard-dose brain ["1"8F]FDG PET image and substantially

  1. Radiochromic film calibration for low-energy seed brachytherapy dose measurement

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Hali, E-mail: hamorris@ualberta.ca; Menon, Geetha; Sloboda, Ron S. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

    2014-07-15

    Purpose: Radiochromic film dosimetry is typically performed for high energy photons and moderate doses characterizing external beam radiotherapy (XRT). The purpose of this study was to investigate the accuracy of previously established film calibration procedures used in XRT when applied to low-energy, seed-based brachytherapy at higher doses, and to determine necessary modifications to achieve similar accuracy in absolute dose measurements. Methods: Gafchromic EBT3 film was used to measure radiation doses upwards of 35 Gy from 75 kVp, 200 kVp, 6 MV, and (∼28 keV) I-125 photon sources. For the latter irradiations a custom phantom was built to hold a single I-125 seed. Film pieces were scanned with an Epson 10000XL flatbed scanner and the resulting 48-bit RGB TIFF images were analyzed using both FilmQA Pro software andMATLAB. Calibration curves relating dose and optical density via a rational functional form for all three color channels at each irradiation energy were determined with and without the inclusion of uncertainties in the measured optical densities and dose values. The accuracy of calibration curve variations obtained using piecewise fitting, a reduced film measurement area for I-125 irradiation, and a reduced number of dose levels was also investigated. The energy dependence of the film lot used was also analyzed by calculating normalized optical density values. Results: Slight differences were found in the resulting calibration curves for the various fitting methods used. The accuracy of the calibration curves was found to improve at low doses and worsen at high doses when including uncertainties in optical densities and doses, which may better represent the variability that could be seen in film optical density measurements. When exposing the films to doses > 8 Gy, two-segment piecewise fitting was found to be necessary to achieve similar accuracies in absolute dose measurements as when using smaller dose ranges. When reducing the film measurement

  2. Recent results on the linearity of the dose-response relationship for radiation-induced mutations in human cells by low dose levels

    International Nuclear Information System (INIS)

    Traut, H.

    1987-01-01

    Five studies made by various authors in the last years are discussed, which are significant in that the response of human cells to low-dose irradiation is determined directly and not by extrapolation, and which also provide information on the mutagenic effects of low radiation doses. The results of these studies do not indicate any other than a linear response for induction of mutations by low-dose irradiation, nor are there any reasons observable for assuming the existence of a threshold dose. It is very likely therefore that cancer initiation at the low dose level also is characterized by a linear relationship. Although threshold dose levels cannot generally be excluded, and maybe are only too low to be detected by experiment, there is no plausible biophysical argument for assuming the existence of such microdose threshold. (orig./MG) [de

  3. Studies on adaptive response of lymphocyte transformation induced by low-dose irradiation

    International Nuclear Information System (INIS)

    Du Zeji; Su Liaoyuan; Tian Hailin; Zou Huawei

    1995-10-01

    Human peripheral blood lymphocytes stimulated by mitogen in vitro for 24 h were exposed to low-dose γ-ray irradiation (0.5∼4.0 cGy, adaptive dose). They showed an adaptive response to the inhibition of 3 H-TdR incorporation by subsequent higher acute doses of γ-ray (challenge dose). At the interval of 24 h between adaptive dose and challenge dose, the strongest adaptive response induced by low-dose irradiation was found. It is also found that the response induced by 1.0 cGy of adaptive dose was more obvious than that by other doses and that 3.0 Gy of challenge dose produced the strongest adaptive response. As the challenge doses increased, the adaptive response reduced. (2 figs., 2 tabs.)

  4. Effects of Antenatal Betamethasone and Dexamethasone in Preterm Neonates

    Directory of Open Access Journals (Sweden)

    Chen-Yu Chen

    2005-09-01

    Conclusion: In our study, no significant differences between antenatal betamethasone and dexamethasone were found in complications of preterm neonates. Incomplete courses of antenatal corticosteroids were associated with an increased incidence of RDS compared with complete courses.

  5. 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

  6. Measurement of extremely low level dose with LiF(Mg,Cu,P) TL chips

    International Nuclear Information System (INIS)

    Zha Ziying; Wang Shoushan; Wu Fang; Chen Guolong; Li Yuanfang; Zhu Jianhuan

    1986-01-01

    This paper presents some of the dosimetric characteristics of newly developed LiF(Mg,Cu,P) TL chips with high signal-to-noise ratio for measurement at the 10 -7 to 10 -4 Gy dose level. Measuring techniques and optimum procedures for annealing and readout are also presented. (author)

  7. Intracameral dexamethasone reduces inflammation on the first postoperative day after cataract surgery in eyes with and without glaucoma.

    Science.gov (United States)

    Chang, Diane T W; Herceg, Michael C; Bilonick, Richard A; Camejo, Larissa; Schuman, Joel S; Noecker, Robert J

    2009-01-01

    To evaluate whether dexamethasone injected intracamerally at the conclusion of surgery can safely and effectively reduce postoperative inflammation and improve surgical outcomes in eyes with and without glaucoma. Retrospective chart review of 176 consecutive eyes from 146 patients receiving uncomplicated phacoemulsification (PE) (n = 118 total, 82 with glaucoma), glaucoma drainage device (GDD) (n = 35), combined PE/GDD (n = 11) and combined PE/endoscopic cyclophotocoagulation (n = 12). Ninety-one eyes from 76 patients were injected with 0.4 mg dexamethasone intracamerally at the conclusion of surgery. All eyes received standard postoperative prednisolone and ketorolac eyedrops. Outcomes were measured for four to eight weeks by subjective complaints, visual acuity (VA), slit-lamp biomicroscopy, intraocular pressure (IOP) and postoperative complications. Dexamethasone significantly reduced the odds of having an increased anterior chamber (AC) cell score after PE (p = 0.0013). Mean AC cell score +/- SD in nonglaucomatous eyes was 1.3 +/- 0.8 in control and 0.8 +/- 0.7 with dexamethasone; scores in glaucomatous eyes were 1.3 +/- 0.7 in control and 0.9 +/- 0.8 with dexamethasone. Treated nonglaucomatous eyes had significantly fewer subjective complaints after PE (22.2% vs 64.7% in control; p = 0.0083). Dexamethasone had no significant effects on VA, corneal changes, IOP one day and one month after surgery, or long-term complications. Intracameral dexamethasone given at the end of cataract surgery significantly reduces postoperative AC cells in eyes with and without glaucoma, and improves subjective reports of recovery in nonglaucomatous eyes. There were no statistically significant risks of IOP elevation or other complications in glaucomatous eyes.

  8. Benefits of sinogram-affirmed iterative reconstruction in 0.4 mSv ultra-low-dose CT of the upper abdomen following transarterial chemoembolisation: comparison to low-dose and standard-dose CT and filtered back projection technique

    International Nuclear Information System (INIS)

    Bodelle, B.; Isler, S.; Scholtz, J.-E.; Frellesen, C.; Luboldt, W.; Vogl, T.J.; Beeres, M.

    2016-01-01

    Aim: To evaluate the advantage of sinogram-affirmed iterative reconstruction (SIR) compared to filtered back projection (FBP) in upper abdomen computed tomography (CT) after transarterial chemoembolisation (TACE) at different tube currents. Materials and methods: The study was approved by the institutional review board. Written informed consent was obtained from all patients. Post-TACE CT was performed with different tube currents successively varied in four steps (180, 90, 45 and 23 mAs) with 40 patients per group (mean age: 60±12 years, range: 23–85 years, sex: 70 female, 90 male). The data were reconstructed with standard FBP and five different SIR strengths. Image quality was independently rated by two readers on a five-point scale. High (Lipiodol-to-liver) as well as low (liver-to-fat) contrast-to-noise ratios (CNRs) were intra-individually compared within one dose to determine the optimal strength (S1–S5) and inter-individually between different doses to determine the possibility of dose reduction using the Kruskal–Wallis test. Results: Subjective image quality and objective CNR analysis were concordant: intra-individually, SIR was significantly (p<0.001) superior to FBP. Inter-individually, regarding different doses (180 versus 23 ref mAs), there was no significant (p=1.00) difference when using S5 SIR at 23 mAs instead of FBP. Conclusion: SIR allows for an 88% dose reduction from 3.43 to 0.4 mSv in unenhanced CT of the liver following TACE without subjective or objective loss in image quality. - Highlights: • Diagnostic image quality and radiation dose of ultra-low-dose CT of the upper abdomen using sinogram affirmed iterative reconstruction following transarterial chemoembolization in comparison to low-dose and standard dose CT and filtered back projection technique. • Ultra-low dose CT of the upper abdomen using sinogram affirmed iterative reconstruction allows for significant dose reduction by 88%. • Ultra-low dose CT of the upper abdomen

  9. Low-dose CT image reconstruction using gain intervention-based dictionary learning

    Science.gov (United States)

    Pathak, Yadunath; Arya, K. V.; Tiwari, Shailendra

    2018-05-01

    Computed tomography (CT) approach is extensively utilized in clinical diagnoses. However, X-ray residue in human body may introduce somatic damage such as cancer. Owing to radiation risk, research has focused on the radiation exposure distributed to patients through CT investigations. Therefore, low-dose CT has become a significant research area. Many researchers have proposed different low-dose CT reconstruction techniques. But, these techniques suffer from various issues such as over smoothing, artifacts, noise, etc. Therefore, in this paper, we have proposed a novel integrated low-dose CT reconstruction technique. The proposed technique utilizes global dictionary-based statistical iterative reconstruction (GDSIR) and adaptive dictionary-based statistical iterative reconstruction (ADSIR)-based reconstruction techniques. In case the dictionary (D) is predetermined, then GDSIR can be used and if D is adaptively defined then ADSIR is appropriate choice. The gain intervention-based filter is also used as a post-processing technique for removing the artifacts from low-dose CT reconstructed images. Experiments have been done by considering the proposed and other low-dose CT reconstruction techniques on well-known benchmark CT images. Extensive experiments have shown that the proposed technique outperforms the available approaches.

  10. Dexamethasone facilitates fear extinction and safety discrimination in PTSD: A placebo-controlled, double-blind study.

    Science.gov (United States)

    Michopoulos, Vasiliki; Norrholm, Seth D; Stevens, Jennifer S; Glover, Ebony M; Rothbaum, Barbara O; Gillespie, Charles F; Schwartz, Ann C; Ressler, Kerry J; Jovanovic, Tanja

    2017-09-01

    Psychophysiological hallmarks of posttraumatic stress disorder (PTSD) include exaggerated fear responses, impaired inhibition and extinction of conditioned fear, and decreased discrimination between safety and fear cues. This increased fear load associated with PTSD can be a barrier to effective therapy thus indicating the need for new treatments to reduce fear expression in people with PTSD. One potential biological target for reducing fear expression in PTSD is the hypothalamic-pituitary-adrenal (HPA) axis, which is dysregulated in PTSD. Recent translational rodent studies and cross-sectional clinical studies have shown that dexamethasone administration and the resulting suppression of cortisol in individuals with PTSD leads to a decrease in the fear responses characteristic of PTSD. These data, taken together, suggest that dexamethasone may serve as a novel pharmacologic intervention for heightened fear responses in PTSD. We conducted a double-blind, placebo-controlled trial to test our hypothesis that dexamethasone administration and the concomitant suppression of HPA axis hyperactivity would attenuate fear expression and enhance fear extinction in individuals with PTSD. Study participants (n=62) were recruited from Grady Memorial Hospital in Atlanta, GA. Participants were randomized to receive dexamethasone or placebo prior to fear conditioning and extinction, in a counterbalanced design (treatments separated by a week). Both PTSD- (n=37) and PTSD+ (n=25) participants showed significant startle increases in the presence of the danger signal during placebo and dexamethasone treatments (all pextinction blocks during both conditions (p's≤0.001), with PTSD+ participants showing deficits in fear extinction and safety discrimination in the placebo condition. Notably, extinction and discrimination deficits in PTSD+ subjects were markedly reversed with dexamethasone (pextinction and discrimination in individuals with PTSD. Copyright © 2017 Elsevier Ltd. All rights

  11. Study of genomic instability induced by low dose ionizing radiation

    International Nuclear Information System (INIS)

    Seoane, A.; Crudeli, C.; Dulout, F.

    2006-01-01

    The crews of commercial flights and services staff of radiology and radiotherapy from hospitals are exposed to low doses of ionizing radiation. Genomic instability includes those adverse effects observed in cells, several generations after the exposure occurred. The purpose of this study was to analyze the occurrence of genomic instability by very low doses of ionizing radiation [es

  12. Direct synthesis of ultrathin SOI structure by extremely low-energy oxygen implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Yasushi, E-mail: yhoshino@kanagawa-u.ac.jp; Yachida, Gosuke; Inoue, Kodai; Toyohara, Taiga; Nakata, Jyoji [Department of mathematics and physics, Kanagawa University, 2946, Tsuchiya, Hiratsuka, Kanagawa 259-1293 (Japan)

    2016-06-15

    We performed extremely low-energy {sup 16}O{sup +} implantation at 10 keV (R{sub p} ∼ 25 nm) followed by annealing aiming at directly synthesizing an ultrathin Si layer separated by a buried SiO{sub 2} layer in Si(001) substrates, and then investigated feasible condition of recrystallization and stabilization of the superficial Si and the buried oxide layer by significantly low temperature annealing. The elemental compositions were analyzed by Rutherford backscattering (RBS) and secondary ion mass spectroscopy (SIMS). The crystallinity of the superficial Si layer was quantitatively confirmed by ananlyzing RBS-channeling spectra. Cross-sectional morphologies and atomic configurations were observed by transmission electron microscope (TEM). As a result, we succeeded in directly synthesizing an ultrathin single-crystalline silicon layer with ≤20 nm thick separated by a thin buried stoichiometric SiO{sub 2} layer with ≤20 nm thick formed by extremely low-energy {sup 16}O{sup +} implantation followed by surprisingly low temperature annealing at 1050{sup ∘} C.

  13. Value of low-dose 2 X 2 Gy palliative radiotherapy in advanced low-grade non-Hodgkin's lymphoma

    International Nuclear Information System (INIS)

    Ng, M.; Wirth, A.; Ryan, G.; MacManus, M.

    2006-01-01

    Low-dose radiotherapy over the last decade has been reported to provide effective palliation for patients with low-grade non-Hodgkin's lymphoma. In this retrospective case series of 10 patients, we report our early experience using low-dose radiotherapy (usually 2 x2 Gy) for patients with advanced-stage follicular, mucosal associated lymphoid tissue, mantle cell and small lymphocytic lymphomas. Median follow up was 27 weeks. Response rates were high (complete response, 70%; partial response, 20%), the response durable and the toxicity was minimal (no toxicity greater than grade 1). Low-dose irradiation is an effective treatment option for patients with low-grade lymphomas with local symptoms Copyright (2006) Blackwell Publishing Asia Pty Ltd

  14. Synergistic Effects of Ad-Libitum Low-Dose Fructose Drinking and Low-Dose Streptozotocin Treatment in Wistar Rats: A Mild Model of Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Asie Sadeghi

    2017-07-01

    Full Text Available To develop a convenient animal model of T2D by pretreatment with low-dose 10% w/v fructose (FRC solution followed by the injection of low doses of streptozotocin (STZ in Wistar rats. For this 8-week experimental study; rats were first fed a standard chow ad-libitum diet and either tap water (n=40 or 10% w/v FRC solution (n=40 for 4 weeks. Next, rats in each category were randomly allocated to 4 subgroups (n=10 each of low-dose STZ (25,35, and 45 mg/kg. The final mean fasting blood sugar (FBG of FRC+STZ45 (197±55.87 mg/dl were significantly higher than that of the STZ45 (P=0.015 and FRC (P=0.019 groups. FRC+STZ45 showed the highest insulin resistance demonstrated by insulin tolerance test [area under the curve (AUC of insulin tolerance test; P<0.05]. AUC was not significantly different between the STZ45 and non-STZ groups and between FRC and non-FRC fed groups. Furthermore, FBG levels did not differ between FRC and non-FRC groups. Body weight measurement showed that the FRC+STZ45 group had the lowest body weight compared to all other groups. Our data provide the evidence that FRC and STZ45 synergistically could induce hyperglycemia and insulin resistance in Wistar rats. Here we presented a feasible model for initial forms of T2D by employing pretreatment with low-dose FRC solution and treatment with low-dose STZ.

  15. Longstanding refractory pseudophakic cystoid macular edema resolved using intravitreal 0.7 mg dexamethasone implants

    Directory of Open Access Journals (Sweden)

    Brynskov T

    2013-06-01

    Full Text Available Troels Brynskov,1,2 Caroline Schmidt Laugesen,1 Jakob Halborg,1 Henrik Kemp,1 Torben Lykke Sørensen1,21Department of Ophthalmology, Copenhagen University Hospital Roskilde, Roskilde, Denmark; 2Faculty of Health Sciences, University of Copenhagen, Copenhagen, DenmarkBackground: Refractory pseudophakic cystoid macular edema (PCME following cataract surgery has long posed a challenge to clinicians, but intravitreal injections with a sustained delivery 0.7 mg dexamethasone implant has emerged as a promising therapy for this condition.Objective: To present a case of longstanding and refractory PCME with complete remission through 189 days of follow-up after two successive injections with intravitreal dexamethasone implants.Case report: A 59-year-old male had experienced metamorphopsia for approximately 4 years and had been diagnosed with PCME 15 months earlier. Since the time of the diagnosis, the condition had been refractory to both subtenon triamcinolone acetonide and a total of five injections with intravitreal ranibizumab. After the last injection with ranibizumab, central subfield mean thickness was 640 µm, and the best corrected visual acuity was 78 Early Treatment Diabetic Retinopathy Study letters. Following an intravitreal injection with a dexamethasone implant, the macular edema resolved at the next follow-up. The macular edema returned 187 days after the first injection and was treated with another intravitreal dexamethasone implant. Again, the macular edema subsided completely, and best corrected visual acuity improved to 84 Early Treatment Diabetic Retinopathy Study letters, a condition which was maintained through an additional 189 days of follow-up.Conclusion: Chronic PCME is traditionally a difficult condition to treat, but we are encouraged by the optimal response experienced with intravitreal sustained release dexamethasone implants in our patient whose longstanding PCME had been refractory to previous treatments with both

  16. Neurodevelopmental outcomes of triplets or higher-order extremely low birth weight infants.

    Science.gov (United States)

    Wadhawan, Rajan; Oh, William; Vohr, Betty R; Wrage, Lisa; Das, Abhik; Bell, Edward F; Laptook, Abbot R; Shankaran, Seetha; Stoll, Barbara J; Walsh, Michele C; Higgins, Rosemary D

    2011-03-01

    Extremely low birth weight twins have a higher rate of death or neurodevelopmental impairment than singletons. Higher-order extremely low birth weight multiple births may have an even higher rate of death or neurodevelopmental impairment. Extremely low birth weight (birth weight 401-1000 g) multiple births born in participating centers of the Neonatal Research Network between 1996 and 2005 were assessed for death or neurodevelopmental impairment at 18 to 22 months' corrected age. Neurodevelopmental impairment was defined by the presence of 1 or more of the following: moderate to severe cerebral palsy; mental developmental index score or psychomotor developmental index score less than 70; severe bilateral deafness; or blindness. Infants who died within 12 hours of birth were excluded. Maternal and infant demographic and clinical variables were compared among singleton, twin, and triplet or higher-order infants. Logistic regression analysis was performed to establish the association between singletons, twins, and triplet or higher-order multiples and death or neurodevelopmental impairment, controlling for confounding variables that may affect death or neurodevelopmental impairment. Our cohort consisted of 8296 singleton, 2164 twin, and 521 triplet or higher-order infants. The risk of death or neurodevelopmental impairment was increased in triplets or higher-order multiples when compared with singletons (adjusted odds ratio: 1.7 [95% confidence interval: 1.29-2.24]), and there was a trend toward an increased risk when compared with twins (adjusted odds ratio: 1.27 [95% confidence: 0.95-1.71]). Triplet or higher-order births are associated with an increased risk of death or neurodevelopmental impairment at 18 to 22 months' corrected age when compared with extremely low birth weight singleton infants, and there was a trend toward an increased risk when compared with twins.

  17. The effect of a chitosan-gelatin matrix and dexamethasone on the behavior of rabbit mesenchymal stem cells

    International Nuclear Information System (INIS)

    Medrado, G C B; Machado, C B; Valerio, P; Sanches, M D; Goes, A M

    2006-01-01

    Cartilage tissue has poor capability of self-repair, especially in the case of severe cartilage damage due to trauma or age-related degeneration. Cell-based tissue engineering using scaffolds has provided an option for the repair of defects in adult cartilage tissue. Mesenchymal stem cells (MSC) and chondrocytes are the two major cell sources for cartilage tissue engineering. The present study combined culture conditions of MSC in a chitosan-gelatin matrix in chondrogenic media to evaluate their effects on MSC viability and chondrogenesis for cartilage tissue engineering. MSC were harvested from rabbit bone marrows and cultured in chondrogenic media supplemented, or not, with dexamethasone in a chitosan-gelatin film (C-GF). The association of C-GF and dexamethasone promoted significant increase in cell adhesivity, viability and proliferation when compared to MCS cultured in media without dexamethasone or C-GF. In addition, dexamethasone promoted increase in the collagen concentration of MSC cultures. A reduction of alkaline phosphatase activity after three weeks of culture in chondrogenic media was verified. No influence of the C-GF or of dexamethasone was observed in this matter. Therefore, it is reasonable to suggest that biomaterial-based chitosan-gelatin and chondrogenic media supplemented with dexamethasone may stimulate the proliferation and differentiation of MSC according to the complex environmental conditions. The information presented here should be useful for the development of biomaterials to regulate the chondrogenesis of MSC suitable for cartilage tissue engineering

  18. The effect of a chitosan-gelatin matrix and dexamethasone on the behavior of rabbit mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Medrado, G C B [Medicine School, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Machado, C B [Biochemistry and Immunology Department, Biological Sciences Institute, UFMG - Federal University of Minas Gerais, mailbox 486, zip code 31270-901, Belo Horizonte, MG (Brazil); Valerio, P [Biochemistry and Immunology Department, Biological Sciences Institute, UFMG - Federal University of Minas Gerais, mailbox 486, zip code 31270-901, Belo Horizonte, MG (Brazil); Sanches, M D [Medicine School, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Goes, A M [Biochemistry and Immunology Department, Biological Sciences Institute, UFMG - Federal University of Minas Gerais, mailbox 486, zip code 31270-901, Belo Horizonte, MG (Brazil)

    2006-09-15

    Cartilage tissue has poor capability of self-repair, especially in the case of severe cartilage damage due to trauma or age-related degeneration. Cell-based tissue engineering using scaffolds has provided an option for the repair of defects in adult cartilage tissue. Mesenchymal stem cells (MSC) and chondrocytes are the two major cell sources for cartilage tissue engineering. The present study combined culture conditions of MSC in a chitosan-gelatin matrix in chondrogenic media to evaluate their effects on MSC viability and chondrogenesis for cartilage tissue engineering. MSC were harvested from rabbit bone marrows and cultured in chondrogenic media supplemented, or not, with dexamethasone in a chitosan-gelatin film (C-GF). The association of C-GF and dexamethasone promoted significant increase in cell adhesivity, viability and proliferation when compared to MCS cultured in media without dexamethasone or C-GF. In addition, dexamethasone promoted increase in the collagen concentration of MSC cultures. A reduction of alkaline phosphatase activity after three weeks of culture in chondrogenic media was verified. No influence of the C-GF or of dexamethasone was observed in this matter. Therefore, it is reasonable to suggest that biomaterial-based chitosan-gelatin and chondrogenic media supplemented with dexamethasone may stimulate the proliferation and differentiation of MSC according to the complex environmental conditions. The information presented here should be useful for the development of biomaterials to regulate the chondrogenesis of MSC suitable for cartilage tissue engineering.

  19. Comparison of radiosensitization by 41 deg. C hyperthermia during low dose rate irradiation and during pulsed simulated low dose rate irradiation in human glioma cells

    International Nuclear Information System (INIS)

    Raaphorst, G. Peter; Ng, Cheng E.; Shahine, Bilal

    1999-01-01

    Purpose: Long duration mild hyperthermia has been shown to be an effective radiosensitizer when given concurrently with low dose rate irradiation. Pulsed simulated low dose rate (PSLDR) is now being used clinically, and we have set out to determine whether concurrent mild hyperthermia can be an effective radiosensitizer for the PSLDR protocol. Materials and Methods: Human glioma cells (U-87MG) were grown to plateau phase and treated in plateau phase in order to minimize cell cycle redistribution during protracted treatments. Low dose rate (LDR) irradiation and 41 deg. C hyperthermia were delivered by having a radium irradiator inside a temperature-controlled incubator. PSLDR was given using a 150 kVp X-ray unit and maintaining the cells at 41 deg. C between irradiations. The duration of irradiation and concurrent heating depended on total dose and extended up to 48 h. Results: When 41 deg. C hyperthermia was given currently with LDR or PSLDR, the thermal enhancement ratios (TER) were about the same if the average dose rate for PSLDR was the same as for LDR. At higher average dose rates for PSLDR the TERs became less. Conclusions: Our data show that concurrent mild hyperthermia can be an effective sensitizer for PSLDR. This sensitization can be as effective as for LDR if the same average dose rate is used and the TER increases with decreasing dose rate. Thus mild hyperthermia combined with PSLDR may be an effective clinical protocol

  20. Low dose dynamic CT myocardial perfusion imaging using a statistical iterative reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Yinghua [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Chen, Guang-Hong [Department of Medical Physics and Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Hacker, Timothy A.; Raval, Amish N. [Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Van Lysel, Michael S.; Speidel, Michael A., E-mail: speidel@wisc.edu [Department of Medical Physics and Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2014-07-15

    Purpose: Dynamic CT myocardial perfusion imaging has the potential to provide both functional and anatomical information regarding coronary artery stenosis. However, radiation dose can be potentially high due to repeated scanning of the same region. The purpose of this study is to investigate the use of statistical iterative reconstruction to improve parametric maps of myocardial perfusion derived from a low tube current dynamic CT acquisition. Methods: Four pigs underwent high (500 mA) and low (25 mA) dose dynamic CT myocardial perfusion scans with and without coronary occlusion. To delineate the affected myocardial territory, an N-13 ammonia PET perfusion scan was performed for each animal in each occlusion state. Filtered backprojection (FBP) reconstruction was first applied to all CT data sets. Then, a statistical iterative reconstruction (SIR) method was applied to data sets acquired at low dose. Image voxel noise was matched between the low dose SIR and high dose FBP reconstructions. CT perfusion maps were compared among the low dose FBP, low dose SIR and high dose FBP reconstructions. Numerical simulations of a dynamic CT scan at high and low dose (20:1 ratio) were performed to quantitatively evaluate SIR and FBP performance in terms of flow map accuracy, precision, dose efficiency, and spatial resolution. Results: Forin vivo studies, the 500 mA FBP maps gave −88.4%, −96.0%, −76.7%, and −65.8% flow change in the occluded anterior region compared to the open-coronary scans (four animals). The percent changes in the 25 mA SIR maps were in good agreement, measuring −94.7%, −81.6%, −84.0%, and −72.2%. The 25 mA FBP maps gave unreliable flow measurements due to streaks caused by photon starvation (percent changes of +137.4%, +71.0%, −11.8%, and −3.5%). Agreement between 25 mA SIR and 500 mA FBP global flow was −9.7%, 8.8%, −3.1%, and 26.4%. The average variability of flow measurements in a nonoccluded region was 16.3%, 24.1%, and 937