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Sample records for 10-fold higher dose

  1. Potential Microbiological Effects of Higher Dosing of Echinocandins.

    PubMed

    Steinbach, William J; Lamoth, Frédéric; Juvvadi, Praveen R

    2015-12-01

    The antifungal "paradoxical effect" has been described as the reversal of growth inhibition at high doses of echinocandins, most usually caspofungin. This microbiological effect appears to be a cellular compensatory response to cell wall damage, resulting in alteration of cell wall content and structure as well as fungal morphology and growth. In vitro studies demonstrate this reproducible effect in a certain percentage of fungal isolates, but animal model and clinical studies are less consistent. The calcineurin and Hsp90 cell signaling pathways appear to play a major role in regulating these cellular and structural changes. Regardless of the clinical relevance of this paradoxical growth effect, understanding the specific actions of echinocandins is paramount to optimizing their use at either standard or higher dosing schemes, as well as developing future improvements in our antifungal arsenal. PMID:26567286

  2. Splenectomy Causes 10-Fold Increased Risk of Portal Venous System Thrombosis in Liver Cirrhosis Patients

    PubMed Central

    Qi, Xingshun; Han, Guohong; Ye, Chun; Zhang, Yongguo; Dai, Junna; Peng, Ying; Deng, Han; Li, Jing; Hou, Feifei; Ning, Zheng; Zhao, Jiancheng; Zhang, Xintong; Wang, Ran; Guo, Xiaozhong

    2016-01-01

    Background Portal venous system thrombosis (PVST) is a life-threatening complication of liver cirrhosis. We conducted a retrospective study to comprehensively analyze the prevalence and risk factors of PVST in liver cirrhosis. Material/Methods All cirrhotic patients without malignancy admitted between June 2012 and December 2013 were eligible if they underwent contrast-enhanced CT or MRI scans. Independent predictors of PVST in liver cirrhosis were calculated in multivariate analyses. Subgroup analyses were performed according to the severity of PVST (any PVST, main portal vein [MPV] thrombosis >50%, and clinically significant PVST) and splenectomy. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. Results Overall, 113 cirrhotic patients were enrolled. The prevalence of PVST was 16.8% (19/113). Splenectomy (any PVST: OR=11.494, 95%CI=2.152–61.395; MPV thrombosis >50%: OR=29.987, 95%CI=3.247–276.949; clinically significant PVST: OR=40.415, 95%CI=3.895–419.295) and higher hemoglobin (any PVST: OR=0.974, 95%CI=0.953–0.996; MPV thrombosis >50%: OR=0.936, 95%CI=0.895–0.980; clinically significant PVST: OR=0.935, 95%CI=0.891–0.982) were the independent predictors of PVST. The prevalence of PVST was 13.3% (14/105) after excluding splenectomy. Higher hemoglobin was the only independent predictor of MPV thrombosis >50% (OR=0.952, 95%CI=0.909–0.997). No independent predictors of any PVST or clinically significant PVST were identified in multivariate analyses. Additionally, PVST patients who underwent splenectomy had a significantly higher proportion of clinically significant PVST but lower MELD score than those who did not undergo splenectomy. In all analyses, the in-hospital mortality was not significantly different between cirrhotic patient with and without PVST. Conclusions Splenectomy may increase by at least 10-fold the risk of PVST in liver cirrhosis independent of severity of liver dysfunction. PMID:27432511

  3. CORRELATES OF HIGHER DOSE OPIOID MEDICATION USE FOR LOW BACK PAIN IN PRIMARY CARE

    PubMed Central

    Kobus, Amy M.; Smith, David H.; Morasco, Benjamin J.; Johnson, Eric S.; Yang, Xiuhai; Petrik, Amanda F.; Deyo, Richard A.

    2012-01-01

    Factors associated with high-dose opioid therapy for non-cancer pain are poorly understood. We document the prevalence of high-dose opioid use, as well as associated demographic, clinical, and health service utilization correlates among low back pain patients. Patients prescribed higher-dose opioids (≥100 mg/day morphine equivalent at last dispensing; n=453) and receiving opioids for 90+ consecutive days were compared to two groups: lower-dose (1–99 mg/day; n=4,815) or no opioid use (n=10,184). Higher-dose opioid use occurred in 2.9% of patients who received any opioids and in 8.6% of patients who received opioids long-term. The median dose in the higher-dose group was 180.0 mg/day. Compared to the no opioid group, higher-dose users reported poorer health. Compared to either comparison group, patients in the higher-dose group had higher rates of mental health and substance use disorders, concurrent sedative-hypnotic use (60.5%; n=274), and health service utilization. After adjusting for select covariates, male gender (Odds ratio (OR) 1.68, 95%CI 1.37,2.06), higher comorbidity, Medicare coverage (OR 1.65, 95% CI 1.22,2.23), any mental health or substance use diagnosis (OR 1.58, 95% CI 1.28,1.95), co-prescriptions of sedative-hypnotics (OR 1.75, 95% CI 1.42,2.16), and more Emergency Department and specialty pain clinic visits were associated with higher likelihood of high-dose prescriptions. PMID:23117108

  4. Novel method for quantifying radiation-induced single-strand-break yields in plasmid DNA highlights 10-fold discrepancy.

    PubMed

    Balagurumoorthy, Pichumani; Adelstein, S James; Kassis, Amin I

    2011-10-15

    The widely used agarose gel electrophoresis method for assessing radiation-induced single-strand-break (SSB) yield in plasmid DNA involves measurement of the fraction of relaxed-circular (C) form that migrates independently from the intact supercoiled (SC) form. We rationalized that this method may underestimate the SSB yield since the position of the relaxed-circular form is not altered when the number of SSB per DNA molecule is >1. To overcome this limitation, we have developed a novel method that directly probes and quantifies SSBs. Supercoiled (3)H-pUC19 plasmid samples were irradiated with γ-rays, alkali-denatured, dephosphorylated, and kinated with γ-[(32)P]ATP, and the DNA-incorporated (32)P activities were used to quantify the SSB yields per DNA molecule, employing a standard curve generated using DNA molecules containing a known number of SSBs. The same irradiated samples were analyzed by agarose gel and SSB yields were determined by conventional methods. Comparison of the data demonstrated that the mean SSB yield per plasmid DNA molecule of [21.2±0.59]×10(-2)Gy(-1) as measured by direct probing is ~10-fold higher than that obtained from conventional gel-based methods. These findings imply that the SSB yields inferred from agarose gels need reevaluation, especially when they were utilized in the determination of radiation risk. PMID:21741945

  5. A polymorphism in the VKORC1-regulator calumenin predicts higher warfarin doses in African-Americans

    PubMed Central

    Voora, D; Koboldt, DC; King, CR; Lenzini, PA; Eby, CS; Porche-Sorbet, R; Deych, E; Crankshaw, M; Milligan, PE; McLeod, HL; Patel, SR; Cavallari, LH; Ridker, PM; Grice, GR; Miller, RD; Gage, BF

    2010-01-01

    Background Warfarin demonstrates wide interindividual variability that is partly mediated by variants in CYP2C9 and VKORC1. Whether variants in CALU (vitamin K reductase regulator) influence warfarin dose is unknown. Methods and Results We resequenced CALU regions in a discovery cohort of dose-outliers: patients with high(>90th percentile, n=55) or low(<10th percentile, n=53) dose requirements(after accounting for known genetic and nongenetic variables). One CALU variant, rs339097, was associated with high-doses(p=0.01). We validated this variant as a predictor of higher warfarin doses in two replication cohorts: 1)496 patients of mixed ethnicity, 2)194 African-American patients. The G allele of rs339097(African-American and Caucasian allele frequency 0.14 and 0.002, respectively), was associated with a 14.5%(SD±7%) greater therapeutic dose(p=0.03) in the first replication cohort and a higher than predicted dose in the second replication cohort(allele frequency=0.14, one-sided p=0.03). Conclusions CALU rs339097 A>G is associated with higher warfarin dose requirements independent of known genetic and nongenetic predictors of warfarin dose in African-Americans. PMID:20200517

  6. Do Glioma Patients Derive Any Therapeutic Benefit From Taking a Higher Cumulative Dose of Temozolomide Regimens?

    PubMed Central

    Sun, Hao; Du, Shasha; Liao, Guixiang; Xie, Xiao; Ren, Chen; Yuan, Ya Wei

    2015-01-01

    Abstract Temozolomide (TMZ) is an oral alkylating agent with established effects on the central nervous system of glioblastoma (GBM) patients. Clinical trials have demonstrated a significant impact on overall survival (OS) with TMZ. Ever since, several TMZ regimens have been designed to improve treatment efficacy by increasing the cumulative dose per cycle. We report a meta-analysis to systematically evaluate different treatment schedules of TMZ in GBM patients. All searches that were conducted in the Cochrane library, Science Direct, and PubMed Databases, and 3 randomized controlled trials (1141 patients) were included. OS and progression-free survival (PFS) were the primary outcomes to be pooled. Unexpectedly, this analysis did not reveal any OS or PFS advantage for the high cumulative dose (HCD) regimen compared with the normal cumulative dose regimen (1141 total patients; hazard ratio [HR] 1.07, 95% CI 0.94–1.22, P = 0.31). Then after analyzing the characteristics of the results from each trial, we found that the regimen with a higher peak concentration during a short-term period (daily doses ≥150 mg/m2/d within ≤7 days/cycle) always had a more superior clinical benefit. So we generated a new pooled HR of 1.10 with a 95% CI of 0.96–1.25 (P = 0.17), which prefers the high peak concentration schedule even without a significant difference. The adverse outcome also indicates a significant increased risk of leukopenia (risk ratio 1.59, 95% CI 1.03–2.46, P = 0.04) among the HCD group. Our study suggests that increasing the cumulative dose per cycle is not an ideal way to improve the efficacy of TMZ, and it will lead to increased risk for leukopenia. Future trials should be designed to examine schedules of higher peak concentration rather than the cumulative dose per cycle. PMID:25997057

  7. A single dose of oxytocin nasal spray improves higher-order social cognition in schizophrenia.

    PubMed

    Guastella, Adam J; Ward, Philip B; Hickie, Ian B; Shahrestani, Sara; Hodge, Marie Antoinette Redoblado; Scott, Elizabeth M; Langdon, Robyn

    2015-11-01

    Schizophrenia is associated with significant impairments in both higher and lower order social cognitive performance and these impairments contribute to poor social functioning. People with schizophrenia report poor social functioning to be one of their greatest unmet treatment needs. Recent studies have suggested the potential of oxytocin as such a treatment, but mixed results render it uncertain what aspects of social cognition are improved by oxytocin and, subsequently, how oxytocin might best be applied as a therapeutic. The aim of this study was to determine whether a single dose of oxytocin improved higher-order and lower-order social cognition performance for patients with schizophrenia across a well-established battery of social cognition tests. Twenty-one male patients received both a single dose of oxytocin nasal spray (24IU) and a placebo, two weeks apart in a randomized within-subjects placebo controlled design. Following each administration, participants completed the social cognition tasks, as well as a test of general neurocognition. Results revealed that oxytocin particularly enhanced performance on higher order social cognition tasks, with no effects on general neurocognition. Results for individual tasks showed most improvement on tests measuring appreciation of indirect hints and recognition of social faux pas. These results suggest that oxytocin, if combined to enhance social cognition learning, may be beneficial when targeted at higher order social cognition domains. This study also suggests that these higher order tasks, which assess social cognitive processing in a social communication context, may provide useful markers of response to oxytocin in schizophrenia. PMID:26150070

  8. Elderly Patients Require Higher Doses of Sugammadex for Rapid Recovery from Deep Neuromuscular Block.

    PubMed

    Shin, Seokyung; Han, Dong Woo; Lee, Hye Sun; Song, Mi Kyung; Jun, Eun-Kyung; Kim, So Yeon

    2016-06-01

    This study compared the doses of sugammadex needed for rapid recovery from deep neuromuscular blockade (NMB) between young and elderly adults. Twenty-two young (20-40 yrs) and 22 elderly (≥70 yrs) adults were enrolled, and deep NMB of 1-2 post-tetanic counts was maintained with rocuronium intraoperatively. Predetermined doses of sugammadex were given at the end of surgery starting at 4.0 mg/kg for the first patient of each group. Doses were decreased or increased in following patients by 0.5 mg/kg, depending on the 'success' or 'failure' of rapid recovery in the preceding patient. 'Success' was defined as adequate recovery (train-of-four ratio 0.9) within 2 min. after sugammadex administration. The median (range) of ages was 29 (20-40) and 73 (70-84) yrs for the young and elderly adults, respectively. Doses of sugammadex facilitating adequate recovery from deep NMB within 2 min. in each patient population with 50% and 95% probability were defined as ED50 and ED95 , respectively. The ED50 estimated by the Dixon's method was significantly higher in the elderly compared to young adults [4.2 ± 0.4 mg/kg versus 3.3 ± 0.3 mg/kg, p < 0.001]. The ED50 (83% CI) estimated by isotonic regression was 4.5 (4.2-5.0) mg/kg in elderly adults and 3.3 (3.2-3.4) mg/kg in young adults. The ED95 (95% CI) estimated by isotonic regression was 5.4 (4.9-5.5) mg/kg and 4.4 (3.9-4.5) mg/kg in the elderly and young adults, respectively. In conclusion, dose adjustments of sugammadex should be considered when rapid recovery from deep NMB is needed in elderly adults. PMID:26505986

  9. Higher Chest Wall Dose Results in Improved Locoregional Outcome in Patients Receiving Postmastectomy Radiation

    SciTech Connect

    Panoff, Joseph E.; Takita, Cristiane; Hurley, Judith; Reis, Isildinha M.; Zhao, Wei; Rodgers, Steven E.; Gunaseelan, Vijayalakshmi; Wright, Jean L.

    2012-03-01

    Purpose: Randomized trials demonstrating decreased locoregional recurrence (LRR) and improved overall survival (OS) in women receiving postmastectomy radiation therapy (PMRT) used up to 50 Gy to the chest wall (CW), but in practice, many centers boost the CW dose to {>=}60 Gy, despite lack of data supporting this approach. We evaluated the relationship between CW dose and clinical outcome. Methods and Materials: We retrospectively reviewed medical records of 582 consecutively treated patients who received PMRT between January 1999 and December 2009. We collected data on patient, disease, treatment characteristics, and outcomes of LRR, progression-free survival (PFS) and OS. Results: Median follow-up from the date of diagnosis was 44.7 months. The cumulative 5-year incidence of LRR as first site of failure was 6.2%. CW dose for 7% (43 patients) was {<=}50.4 Gy (range, 41.4-50.4 Gy) and 93% received >50.4 Gy (range, 52.4-74.4 Gy). A CW dose of >50.4 Gy vs. {<=}50.4 Gy was associated with lower incidence of LRR, a 60-month rate of 5.7% (95% confidence interval [CI], 3.7-8.2) vs. 12.7% (95% CI, 4.5-25.3; p = 0.054). Multivariate hazard ratio (HR) for LRR controlling for race, receptor status, and stage was 2.62 (95% CI, 1.02-7.13; p = 0.042). All LRR in the low-dose group occurred in patients receiving 50 to 50.4 Gy. Lower CW dose was associated with worse PFS (multivariate HR, 2.73; 95% CI, 1.64-4.56; p < 0.001) and OS (multivariate HR, 3.88; 95% CI, 2.16-6.99; p < 0.001). Conclusions: The addition of a CW boost above 50.4 Gy resulted in improved locoregional control and survival in this cohort patients treated with PMRT for stage II-III breast cancer. The addition of a CW boost to standard-dose PMRT is likely to benefit selected high-risk patients. The optimal technique, target volume, and patient selection criteria are unknown. The use of a CW boost should be studied prospectively, as has been done in the setting of breast conservation.

  10. Distinct Signaling Pathways After Higher or Lower Doses of Radiation in Three Closely Related Human Lymphoblast Cell Lines

    SciTech Connect

    Lu, T.-P.; Lai, L.-C.; Lin, B.-I.; Chen, L.-H.; Hsiao, T.-H.; Liber, Howard L.; Cook, John A.; Mitchell, James B.; Tsai, M.-H.; Chuang, Eric Y.

    2010-01-15

    Purpose: The tumor suppressor p53 plays an essential role in cellular responses to DNA damage caused by ionizing radiation; therefore, this study aims to further explore the role that p53 plays at different doses of radiation. Materials and Methods: The global cellular responses to higher-dose (10 Gy) and lower dose (iso-survival dose, i.e., the respective D0 levels) radiation were analyzed using microarrays in three human lymphoblast cell lines with different p53 status: TK6 (wild-type p53), NH32 (p53-null), and WTK1 (mutant p53). Total RNAs were extracted from cells harvested at 0, 1, 3, 6, 9, and 24 h after higher and lower dose radiation exposures. Template-based clustering, hierarchical clustering, and principle component analysis were applied to examine the transcriptional profiles. Results: Differential expression profiles between 10 Gy and iso-survival radiation in cells with different p53 status were observed. Moreover, distinct gene expression patterns were exhibited among these three cells after 10 Gy radiation treatment, but similar transcriptional responses were observed in TK6 and NH32 cells treated with iso-survival radiation. Conclusions: After 10 Gy radiation exposure, the p53 signaling pathway played an important role in TK6, whereas the NFkB signaling pathway appeared to replace the role of p53 in WTK1. In contrast, after iso-survival radiation treatment, E2F4 seemed to play a dominant role independent of p53 status. This study dissected the impacts of p53, NFkB and E2F4 in response to higher or lower doses of gamma-irradiation.

  11. Higher Doses of Bisphosphonates Further Improve Bone Mass, Architecture, and Strength but Not the Tissue Material Properties in Aged Rats

    PubMed Central

    Shahnazari, Mohammad; Yao, Wei; Dai, WeiWei; Wang, Bob; Ionova-Martin, Sophi S.; Ritchie, Robert O.; Heeren, Daniel; Burghardt, Andrew J.; Nicolella, Daniel P.; Kimiecik, Michael G.; Lane, Nancy E.

    2010-01-01

    not change with BP even with the higher doses. In summary, the anti fracture efficacy of BP is largely due to their preservation of bone mass and while the higher doses further improve the bone structural properties do not improve the localized bone material characteristics such as tissue strength, elastic modulus, and cortical toughness. PMID:19931661

  12. The H50Q mutation induces a 10-fold decrease in the solubility of α-synuclein.

    PubMed

    Porcari, Riccardo; Proukakis, Christos; Waudby, Christopher A; Bolognesi, Benedetta; Mangione, P Patrizia; Paton, Jack F S; Mullin, Stephen; Cabrita, Lisa D; Penco, Amanda; Relini, Annalisa; Verona, Guglielmo; Vendruscolo, Michele; Stoppini, Monica; Tartaglia, Gian Gaetano; Camilloni, Carlo; Christodoulou, John; Schapira, Anthony H V; Bellotti, Vittorio

    2015-01-23

    The conversion of α-synuclein from its intrinsically disordered monomeric state into the fibrillar cross-β aggregates characteristically present in Lewy bodies is largely unknown. The investigation of α-synuclein variants causative of familial forms of Parkinson disease can provide unique insights into the conditions that promote or inhibit aggregate formation. It has been shown recently that a newly identified pathogenic mutation of α-synuclein, H50Q, aggregates faster than the wild-type. We investigate here its aggregation propensity by using a sequence-based prediction algorithm, NMR chemical shift analysis of secondary structure populations in the monomeric state, and determination of thermodynamic stability of the fibrils. Our data show that the H50Q mutation induces only a small increment in polyproline II structure around the site of the mutation and a slight increase in the overall aggregation propensity. We also find, however, that the H50Q mutation strongly stabilizes α-synuclein fibrils by 5.0 ± 1.0 kJ mol(-1), thus increasing the supersaturation of monomeric α-synuclein within the cell, and strongly favors its aggregation process. We further show that wild-type α-synuclein can decelerate the aggregation kinetics of the H50Q variant in a dose-dependent manner when coaggregating with it. These last findings suggest that the precise balance of α-synuclein synthesized from the wild-type and mutant alleles may influence the natural history and heterogeneous clinical phenotype of Parkinson disease. PMID:25505181

  13. Higher-dose uses of zolpidem will increase the subsequent risk of developing benign brain tumors.

    PubMed

    Harnod, Tomor; Li, Yu-Fen; Lin, Cheng-Li; Chang, Shih-Ni; Sung, Fung-Chang; Kao, Chia-Hung

    2015-01-01

    This study identified 37,810 patients with anxiety or sleep disorder (mean age=53.2 years, SD=16.0 years) who had zolpidem prescribed for at least 2 months from January 1, 2000 through December 31, 2009. Another non-zolpidem cohort was selected by 1:1 matching with the zolpidem cohort on the estimated probability (propensity score) of being treated. The zolpidem cohort had a higher incidence of benign brain tumors compared with the non-zolpidem cohort, particularly for elderly patients. The matched propensity score analysis showed that the highest risk of benign brain tumors occurred in participants with zolpidem exposure ≥520 mg/year (hazard ratio=1.85, 95% confidence interval=1.21-2.82) compared with those not taking zolpidem. PMID:25923854

  14. Higher infused lymphocyte dose predicts higher lymphocyte recovery, which in turn, predicts superior overall survival following autologous hematopoietic stem cell transplantation for multiple myeloma.

    PubMed

    Hiwase, Devendra K; Hiwase, Smita; Bailey, Michael; Bollard, Geraldine; Schwarer, Anthony P

    2008-01-01

    Autologous stem cell transplantation (ASCT) is the standard of care for patients with multiple myeloma (MM) younger than 70 years. However, despite this aggressive therapy most patients will still die of progressive disease. Recent reports have suggested that lymphocyte recovery is an important predictor of relapse or progressive disease in a number of hematologic malignancies including MM. We have conducted retrospective analysis of factors that could predict overall (OS) and progression free survival (PFS) in patients with MM who had ASCT. One hundred nineteen patients with multiple myeloma underwent ASCT. The median OS and PFS were 64 and 32 months, respectively. Univariate and multivariate analysis using Cox proportional hazards regression model showed that absolute lymphocyte count on day 30 following ASCT (ALC-30), international staging system (ISS) stage at diagnosis, and age at diagnosis significantly influenced OS and PFS following ASCT. OS (96 versus 48 months, P = .04) and PFS (43 versus 29 months, P = .03) following ASCT were higher in patients with ALC-30 >or=1.0 x 10(9)/L compared to patients ALC-30 <1.0 x 10(9)/L. Higher ALC-60, ALC-100, ALC-180, and ALC-365 did not predict superior OS and PFS. Patients with early-stage disease had significantly higher OS (ISS stages I, II, and III: 96, 53, and 29 months, respectively; P = .0023) and PFS (ISS stages I, II, and III: 55.5, 31, and 12 months, respectively; P = .027) compared to patients with advanced-stage disease at diagnosis. On univariate analysis, the type of initial chemotherapy (melphalan, VAD, PCAB), lymphocyte count on day of leukapheresis, and the lymphocyte dose infused (LY-DO) significantly influenced lymphocyte recovery following ASCT. Patients who received higher lymphocyte dose (LY-DO) >or=0.2 x 10(9)/kg had higher median ALC-15 (0.25 versus 0.19 x 10(9)/L; P = .3), ALC-30 (1.20 versus 0.99 x 10(9)/L; P = .08), ALC-60 (1.90 versus 1.01 x 10(9)/L; P = .013), ALC-100 (1.58 versus 1.03 x 10

  15. Morphine with adjuvant ketamine versus higher dose of morphine alone for acute pain: a meta-analysis

    PubMed Central

    Ding, Xibing; Jin, Shuqing; Niu, Xiaoyin; Wang, Tingting; Zhao, Xiang; Ren, Hao; Tong, Yao; Li, Quan

    2014-01-01

    Purpose: Ketamine is currently the N-methyl-D-aspartate receptor channel blocker in clinical use. Morphine in pain management is usually limited by adverse effect such as nausea and vomiting. Adjuvant treatment with ketamine may be value in giving better analgesia with fewer adverse effects. The purpose of this meta-analysis was to evaluate the differences when patients received morphine with adjuvant ketamine (MK) compared with higher dose of morphine (MO) for acute pain. Methods: The PubMed, EMBASE and the Cochrane Library databases were searched (Last search performed on July 1, 2014) by two reviewers independently. Data were extracted independently by the same two individuals who searched the studies. Results: A total of 7 trials involving 492 patients were included in the current analysis. We found pain scores were lower in the MK group compared to the MO group [MD 2.19, 95% CI (1.24, 3.13) P<0.00001]. And more patients in the MO required diclofenac [OR 1.97, 95% CI (1.06, 3.67) P=0.03]. Furthermore, morphine plus ketamine can reduced post-operative nausea and vomiting (PONV) [OR 3.71, 95% CI (2.37, 5.80) P<0.00001]. Importantly, the wakefulness scores for the MK group were consistently and significantly better than those for the MO group [MD -1.53, 95% CI (-2.67, -0.40) P=0.008]. Conclusion: The use of ketamine plus 1/4~2/3 the dose of morphine is better than higher dose of morphine alone in reducing pain scores, and rescuing analgesic requirement. It also improved PONV and wakefulness. PMID:25356103

  16. Effects of a higher dose of near-infrared light on clinical signs and neuroprotection in a monkey model of Parkinson's disease.

    PubMed

    Moro, Cécile; El Massri, Nabil; Darlot, Fannie; Torres, Napoleon; Chabrol, Claude; Agay, Diane; Auboiroux, Vincent; Johnstone, Daniel M; Stone, Jonathan; Mitrofanis, John; Benabid, Alim-Louis

    2016-10-01

    We have reported previously that intracranial application of near-infrared light (NIr) - when delivered at the lower doses of 25J and 35J - reduces clinical signs and offers neuroprotection in a subacute MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) monkey model of Parkinson's disease. In this study, we explored whether a higher NIr dose (125J) generated beneficial effects in the same MPTP monkey model (n=15). We implanted an NIr (670nm) optical fibre device within a midline region of the midbrain in macaque monkeys, close to the substantia nigra of both sides. MPTP injections (1.8-2.1mg/kg) were made over a five day period, during which time the NIr device was turned on and left on continuously throughout the ensuing three week survival period. Monkeys were evaluated clinically and their brains processed for immunohistochemistry and stereology. Our results showed that the higher NIr dose did not have any toxic impact on cells at the midbrain implant site. Further, this NIr dose resulted in a higher number of nigral tyrosine hydroxylase immunoreactive cells when compared to the MPTP group. However, the higher NIr dose monkeys showed little evidence for an increase in mean clinical score, number of nigral Nissl-stained cells and density of striatal tyrosine hydroxylase terminations. In summary, the higher NIr dose of 125J was not as beneficial to MPTP-treated monkeys as compared to the lower doses of 25J and 35J, boding well for strategies of NIr dose delivery and device energy consumption in a future clinical trial. PMID:27396907

  17. Resistance to simian immunodeficiency virus low dose rectal challenge is associated with higher constitutive TRIM5α expression in PBMC

    PubMed Central

    2014-01-01

    Background At least six host-encoded restriction factors (RFs), APOBEC3G, TRIM5α, tetherin, SAMHD1, schlafen 11, and Mx2 have now been shown to inhibit HIV and/or SIV replication in vitro. To determine their role in vivo in the resistance of macaques to mucosally-acquired SIV, we quantified both pre-exposure (basal) and post-exposure mRNA levels of these RFs, Mx1, and IFNγ in PBMC, lymph nodes, and duodenum of rhesus macaques undergoing weekly low dose rectal exposures to the primary isolate, SIV/DeltaB670. Results Repetitive challenge divided the monkeys into two groups with respect to their susceptibility to infection: highly susceptible (2–3 challenges, 5 monkeys) and poorly susceptible (≥6 challenges, 3 monkeys). Basal RF and Mx1 expression varied among the three tissues examined, with the lowest expression generally detected in duodenal tissues, and the highest observed in PBMC. The one exception was A3G whose basal expression was greatest in lymph nodes. Importantly, significantly higher basal expression of TRIM5α and Mx1 was observed in PBMC of animals more resistant to mucosal infection. Moreover, individual TRIM5α levels were stable throughout a year prior to infection. Post-exposure induction of these genes was also observed after virus appearance in plasma, with elevated levels in PBMC and duodenum transiently occurring 7–10 days post infection. They did not appear to have an effect on control of viremia. Interestingly, minimal to no induction was observed in the resistant animal that became an elite controller. Conclusions These results suggest that constitutively expressed TRIM5α appears to play a greater role in restricting mucosal transmission of SIV than that associated with type I interferon induction following virus entry. Surprisingly, this association was not observed with the other RFs. The higher basal expression of TRIM5α observed in PBMC than in duodenal tissues emphasizes the understated role of the second barrier to systemic

  18. Higher-Than-Conventional Radiation Doses in Localized Prostate Cancer Treatment: A Meta-analysis of Randomized, Controlled Trials

    SciTech Connect

    Viani, Gustavo Arruda Stefano, Eduardo Jose; Afonso, Sergio Luis

    2009-08-01

    Purpose: To determine in a meta-analysis whether the outcomes in men with localized prostate cancer treated with high-dose radiotherapy (HDRT) are better than those in men treated with conventional-dose radiotherapy (CDRT), by quantifying the effect of the total dose of radiotherapy on biochemical control (BC). Methods and Materials: The MEDLINE, EMBASE, CANCERLIT, and Cochrane Library databases, as well as the proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing HDRT with CDRT for localized prostate cancer. To evaluate the dose-response relationship, we conducted a meta-regression analysis of BC ratios by means of weighted linear regression. Results: Seven RCTs with a total patient population of 2812 were identified that met the study criteria. Pooled results from these RCTs showed a significant reduction in the incidence of biochemical failure in those patients with prostate cancer treated with HDRT (p < 0.0001). However, there was no difference in the mortality rate (p = 0.38) and specific prostate cancer mortality rates (p = 0.45) between the groups receiving HDRT and CDRT. However, there were more cases of late Grade >2 gastrointestinal toxicity after HDRT than after CDRT. In the subgroup analysis, patients classified as being at low (p = 0.007), intermediate (p < 0.0001), and high risk (p < 0.0001) of biochemical failure all showed a benefit from HDRT. The meta-regression analysis also detected a linear correlation between the total dose of radiotherapy and biochemical failure (BC = -67.3 + [1.8 x radiotherapy total dose in Gy]; p = 0.04). Conclusions: Our meta-analysis showed that HDRT is superior to CDRT in preventing biochemical failure in low-, intermediate-, and high-risk prostate cancer patients, suggesting that this should be offered as a treatment for all patients, regardless of their risk status.

  19. Intensified Mycophenolate Mofetil Dosing and Higher Mycophenolic Acid Trough Levels Reduce Severe Acute Graft-versus-Host Disease After Double-Unit Cord Blood Transplantation

    PubMed Central

    Harnicar, S.; Ponce, D.M.; Hilden, P.; Zheng, J.; Devlin, S.M.; Lubin, M.; Pozotrigo, M.; Mathew, S.; Adel, N.; Kernan, N.A.; O'Reilly, R.; Prockop, S.; Scaradavou, A.; Hanash, A.; Jenq, R.; van den Brink, M.; Giralt, S.; Perales, M.A.; Young, J.W.; Barker, J.N.

    2015-01-01

    While mycophenolate mofetil (MMF) has replaced corticosteroids as immunosuppression in cord blood transplantation (CBT), optimal MMF dosing has yet to be established. We intensified MMF dosing from every 12 to 8 hours to augment graft-versus-host disease (GVHD) prophylaxis in double-unit CBT (dCBT) and evaluated outcomes according to the total daily MMF dose/kg in 174 double-unit CBT recipients (median age 39 years, range 1–71) transplanted for hematologic malignancies. Recipients of a MMF dose ≤ the median (36 mg/kg/day) had an increased day 100 grade III-IV acute GVHD (aGVHD) incidence compared with patients who received > 36 mg/kg/day (24% versus 8%, p = 0.008). Recipients of ≤ the median dose who had highly HLA-allele (1-3/6) mismatched dominant units had the highest day 100 grade III-IV aGVHD incidence of 37% (p = 0.009). This finding was confirmed in multivariate analysis (p = 0.053). In 83 patients evaluated for mycophenolic acid (MPA) troughs, those with a mean week 1-2 trough < 0.5 mcg/mL had an increased day 100 grade III-IV aGVHD of 26% versus 9% (p = 0.063), and those who received a low total daily MMF dose and had a low week 1-2 MPA trough had a 40% incidence (p = 0.008). Higher MMF dosing or MPA troughs had no impact on engraftment after myeloablation. This analysis supports intensified MMF dosing in mg/kg/day and MPA trough level monitoring early post-transplant in dCBT recipients. PMID:25687796

  20. Acute effects of higher than standard doses of salbutamol and ipratropium on tiotropium-induced bronchodilation in patients with stable COPD.

    PubMed

    Cazzola, Mario; Santus, Pierachille; D'Adda, Alice; Pizzolato, Silvia; Di Marco, Fabiano; Centanni, Stefano

    2009-06-01

    Knowledge on the effects of the additive bronchodilatory effects of short-acting agents on the top of the effect of long-acting bronchodilators is limited. In this trial, we examined the influence of higher than conventional doses of the short-acting inhaled beta(2)-adrenergic agent salbutamol and the short-acting anticholinergic drug ipratropium bromide on bronchodilation induced by a regular treatment with the long-acting anticholinergic drug tiotropium 18 microg/day in 30 patients with stable COPD. On 3 separate days, a dose-response curve to inhaled salbutamol (100 microg puff-1), ipratropium bromide (20 microg puff-1) or placebo was constructed 3h after inhalation of the last dose of tiotropium, using one puff, one puff, two puffs and two puffs, for a total cumulative dose of 600 microg salbutamol or 120 microg ipratropium bromide. Doses were given at 30-min intervals and measurements made 15 min after each dose. At the highest cumulative dose, salbutamol showed a trend to be more effective than ipratropium bromide in improving FEV(1) (0.157 L vs 0.125 L), and reducing sRaw (-4.52 kPa/s vs 3.57 kPa/s), although the differences between the two treatments were always not significant (p>0.05), whereas there was no substantial difference between the two drugs in changing FVC (0.179 L vs 0.168 L), IC (0.254 L vs 0.240 L), TGV (-0.444 L vs -0.441 L), TLC (-0.334 L vs -0.318 L) and RV (-0.467 L vs -0.498 L). Both drugs did not affect heart rate and SpO2. Our results indicate that there is not much difference in bronchodilation between adding higher than conventional doses of salbutamol or ipratropium bromide to tiotropium in patients with stable COPD. Effective improvement of the pulmonary function may be achieved in such a type of patients by adding salbutamol 600 microg or ipratropium bromide 120 microg to regular tiotropium. These is an interesting finding mainly for those COPD patients suffering from cardiovascular co-morbidities that are at highest risk of

  1. Donor, recipient, and transplant characteristics as risk factors after unrelated donor PBSC transplantation: beneficial effects of higher CD34+ cell dose

    PubMed Central

    Chitphakdithai, Pintip; Logan, Brent R.; Leitman, Susan F.; Anderlini, Paolo; Klein, John P.; Horowitz, Mary M.; Miller, John P.; King, Roberta J.; Confer, Dennis L.

    2009-01-01

    We report outcomes of 932 recipients of unrelated donor peripheral blood stem cell hematopoietic cell transplantation (URD-PBSC HCT) for acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, and myelodysplastic syndrome enrolled on a prospective National Marrow Donor Program trial from 1999 through 2003. Preparative regimens included myeloablative (MA; N = 611), reduced-intensity (RI; N = 160), and nonmyeloablative (NMA; N = 161). For MA recipients, CD34+ counts greater than 3.8 × 106/kg improved neutrophil and platelet engraftment, whereas improved overall survival (OS) and reduced transplant-related mortality (TRM) were seen for all preparative regimens when CD34+ cell doses exceeded 4.5 × 106/kg. Higher infused doses of CD34+ cell dose did not result in increased rates of either acute or chronic graft-versus-host disease (GVHD). Three-year OS and disease-free survival (DFS) of recipients of MA, RI, and NMA approaches were similar (33%, 35%, and 32% OS; 33%, 30%, and 29% DFS, respectively). In summary, recipients of URD-PBSC HCT receiving preparative regimens differing in intensity experienced similar survival. Higher CD34+ cell doses resulted in more rapid engraftment, less TRM, and better 3-year OS (39% versus 25%, MA, P = .004; 38% versus 21% RI/NMA, P = .004) but did not increase the risk of GVHD. This trial was registered at www.clinicaltrials.gov as #NCT00785525. PMID:19608747

  2. New developed DR detector performs radiographs of hand, pelvic and premature chest anatomies at a lower radiation dose and/or a higher image quality.

    PubMed

    Precht, Helle; Tingberg, Anders; Waaler, Dag; Outzen, Claus Bjørn

    2014-02-01

    A newly developed Digital Radiography (DR) detector has smaller pixel size and higher fill factor than earlier detector models. These technical advantages should theoretically lead to higher sensitivity and higher spatial resolution, thus making dose reduction possible without scarifying image quality compared to previous DR detector versions. To examine whether the newly developed Canon CXDI-70C DR detector provides an improved image quality and/or allows for dose reductions in hand and pelvic bone examinations as well as premature chest examinations, compared to the previous (CXDI-55C) DR detector version. A total of 450 images of a technical Contrast-Detail phantom were imaged on a DR system employing various kVp and mAs settings, providing an objective image quality assessment. In addition, 450 images of anthropomorphic phantoms were taken and analyzed by three specialized radiologists using Visual Grading Analysis (VGA). The results from the technical phantom studies showed that the image quality expressed as IQFINV values was on average approximately 45 % higher with the CXDI-70C detector compared to the CXDI-55C detector. Consistently, the VGA results from the anatomical phantom studies indicated that by using the CXDI-70C detector, diagnostic image quality could be maintained at a dose reduction of in average 30 %, depending on anatomy and kVp level. This indicates that the CXDI-70C detector is significantly more sensitive than the previous model, and supports a better clinical image quality. By using the newly developed DR detector a significant dose reduction is possible while maintaining image quality. PMID:24221693

  3. Significance of higher drug concentration in erythrocytes of mice infected with Schistosoma japonicum and treated orally with mefloquine at single doses.

    PubMed

    Tao, Yi; Xue, Jian; Jiang, Bin; Zhang, Hao-Bing; Xiao, Shu-Hua

    2015-12-01

    The purpose of the present study is to understand the pharmacokinetic feature of mefloquine measured by erythrocytes and plasma in Schistosoma japonicum (S. j.)-infected mice and non-infected mice after oral administration of the drug at single doses. A high-performance liquid chromatography (HPLC) method was used to measure the plasma and erythrocyte concentrations of mefloquine at varying intervals posttreatment. Our results demonstrated that in non-infected mice treated orally with mefloquine at an ineffective dose of 50 mg/kg or effective dose of 200 mg/kg for 2-72 h, the erythrocyte-to-plasma ratios of mefloquine were 5.8-11.2 or 2-14.2. On the other hand, in S. j.-infected mice treated with the same single doses of the drug, the erythrocyte and plasma drug concentration ratios were 3.1-4.6 or 2.9-8.5, manifesting that either in infected mice or in non-infected mice that received oral mefloquine resulted in higher concentration of mefloquine in erythrocytes than that in plasma. Unexpectedly, under oral administration of mefloquine at a higher single dose of 200 mg/kg, the pharmacokinetic parameter C max values for plasma from S. j.-infected and non-infected mice were 1.6 ± 0.3 and 2.0 ± 0.4 μg/mL, respectively, which were below the determined in vitro LC50 (50 % lethal concentration) value of 4.93 μg/mL. Therefore, the plasma concentration of mefloquine may display a little effect against schistosomes during the treatment. Although the values of T 1/2 and AUC0-∞ for erythrocytes were significantly longer and higher in infected mice than those of corresponding non-infect mice that received the same single mefloqine dose of 50 mg/kg, the C max value was only 2.6 ± 0.4 μg/mL lower than the determined in vitro LC50, which may explain why this low single dose is ineffective against schistosomes in vivo. After administration of higher mefloquine dose of 200 mg/kg, the C max value for erythrocytes in infected mice was 30 % (7.4 ± 0

  4. Geometrical Sparing Factors for the Rectum and Bladder in the Prediction of Grade 2 and Higher Complications After High-Dose-Rate Brachytherapy for Cervical Cancer

    SciTech Connect

    Chen, S.-W.; Liang, J.-A.; Hung, Y.-C.; Yeh, L.-S.; Chang, W.-C.; Yang, S.-N.; Lin, F.-J.

    2009-12-01

    Purpose: This study aimed to assess the predictive values of geometrical sparing factors for the rectum and bladder in high-dose-rate intracavitary brachytherapy (HDRICB) for Grade 2 and higher late sequelae in patients with cervical cancer. Methods: A total of 392 patients were enrolled in this study. They were treated with external beam radiotherapy to the pelvis, after which HDRICB was performed using Ir-192 remote after-loading at 1-week intervals for three or four sessions. The geometrical sparing factor (GSF) was defined as the average of the ratios between the reference doses and the Point A dose. Results: A total of 46 patients (11.7%) had Grade 2 or higher late rectal complications (36 Grade 2, 9 Grade 3, and 1 Grade 4). In all, 32 patients (8.2%) had Grade 2 or higher late bladder complications (14 Grade 2, 16 Grade 3, and 2 Grade 4). Multivariate analysis demonstrated a high risk of rectal sequelae in patients who developed bladder complications (p = 0.0004, hazard ratio 3.54) and had a rectal GSF greater than 0.7 (p = 0.01, hazard ratio 1.99). The high risk factors for bladder complications were development of rectal complications (p = 0.0004, hazard ratio 3.74), concurrent chemotherapy (p = 0.0001, relative risk 3.94), and a bladder GSF greater than 0.9 (p = 0.01, hazard ratio, 2.53). Conclusion: This study demonstrates the predictive value of GSFs in HDRICB for cervical cancer. Patients with rectal GSFs greater than 0.7 or bladder GSFs greater than 0.9 are at risk for Grade 2 and higher late sequelae.

  5. Long-Term Results of Fixed High-Dose I-131 Treatment for Toxic Nodular Goiter: Higher Euthyroidism Rates in Geriatric Patients

    PubMed Central

    Aktaş, Gül Ege; Turoğlu, Halil Turgut; Erdil, Tanju Yusuf; İnanır, Sabahat; Dede, Fuat

    2015-01-01

    Objective: Geriatric patient population has special importance due to particular challenges. In addition to the increase in incidence of toxic nodular goiter (TNG) with age, it has a high incidence in the regions of low-medium iodine intake such as in our country. The aim of this study was to evaluate the overall outcome of high fixed dose radioiodine (RAI) therapy, and investigate the particular differences in the geriatric patient population. Methods: One hundred and three TNG patients treated with high dose I-131 (370-740 MBq) were retrospectively reviewed. The baseline characteristics; age, gender, scintigraphic patterns and thyroid function tests before and after treatment, as well as follow-up, duration of antithyroid drug (ATD) medication and achievement of euthyroid or hypothyroid state were evaluated. The patient population was divided into two groups as those=>65 years and those who were younger, in order to assess the effect of age. Results: Treatment success was 90% with single dose RAI therapy. Hyperthyroidism was treated in 7±7, 2 months after RAI administration. At the end of the first year, overall hypothyroidism rate was 30% and euthyroid state was achieved in 70% of patients. Age was found to be the only statistically significant variable effecting outcome. A higher ratio of euthyroidism was achieved in the geriatric patient population. Conclusion: High fixed dose I-131 treatment should be preferred in geriatric TNG patients in order to treat persistent hyperthyroidism rapidly. The result of this study suggests that high fixed dose RAI therapy is a successful modality in treating TNG, and high rates of euthyroidism can be achieved in geriatric patients.

  6. Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO

    SciTech Connect

    Perez-Calatayud, Jose; Ballester, Facundo; Das, Rupak K.; DeWerd, Larry A.; Ibbott, Geoffrey S.; Meigooni, Ali S.; Ouhib, Zoubir; Rivard, Mark J.; Sloboda, Ron S.; Williamson, Jeffrey F.

    2012-05-15

    Purpose: Recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on dose calculations for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources are presented, including the physical characteristics of specific {sup 192}Ir, {sup 137}Cs, and {sup 60}Co source models. Methods: This report has been prepared by the High Energy Brachytherapy Source Dosimetry (HEBD) Working Group. This report includes considerations in the application of the TG-43U1 formalism to high-energy photon-emitting sources with particular attention to phantom size effects, interpolation accuracy dependence on dose calculation grid size, and dosimetry parameter dependence on source active length. Results: Consensus datasets for commercially available high-energy photon sources are provided, along with recommended methods for evaluating these datasets. Recommendations on dosimetry characterization methods, mainly using experimental procedures and Monte Carlo, are established and discussed. Also included are methodological recommendations on detector choice, detector energy response characterization and phantom materials, and measurement specification methodology. Uncertainty analyses are discussed and recommendations for high-energy sources without consensus datasets are given. Conclusions: Recommended consensus datasets for high-energy sources have been derived for sources that were commercially available as of January 2010. Data are presented according to the AAPM TG-43U1 formalism, with modified interpolation and extrapolation techniques of the AAPM TG-43U1S1 report for the 2D anisotropy function and radial dose function.

  7. Evaluating higher doses of Shunthi - Guduchi formulations for safety in treatment of osteoarthritis knees: A Government of India NMITLI arthritis project

    PubMed Central

    Chopra, Arvind; Saluja, Manjit; Tillu, Girish; Venugopalan, Anuradha; Narsimulu, Gumdal; Sarmukaddam, Sanjeev; Patwardhan, Bhushan

    2012-01-01

    Background: Results of an exploratory trial suggested activity trends of Zingiber officinale-Tinopsora cordifolia (platform combination)-based formulations in the treatment of Osteoarthritis (OA) Knees. These formulations were “platform combination+Withania somnifera+Tribulus terrestris” (formulation B) and “platform combination+Emblica officinale” (formulation C). This paper reports safety of these formulations when used in higher doses (1.5–2 times) along with Sallaki Guggul and Bhallataka Parpati (a Semecarpus anacardium preparation). Materials and Methods: Ninety-two patients with symptomatic OA knees were enrolled in a 6 weeks investigator blind, randomized parallel efficacy 4-arm multicenter drug trial. The 4 arms were (I) formulation B, 2 t.i.d.; (II) formulation B, 2 q.i.d.; (III) platform combination+Sallaki Guggul; (IV) Bhallataka Parpati+formulation C. A detailed enquiry was carried out for adverse events (AE) and drug toxicity as per a priori check list and volunteered information. Laboratory evaluation included detailed hematology and metabolic parameters. Patients were examined at baseline, first and fourth weeks, and on completion. Standard statistical program (SPSS version 12.5) was used for analysis. Results: None of the patients reported serious AE or withdrew due to any drug-related toxicity. Mild gut–related (mostly epigastric burning) AE was reported. A mild increase in liver enzymes [serum glutamic pyruvate transaminase (SGPT), serum glutamic oxaloacetic transaminase (SGOT)] without any other hepatic abnormality was reported in 2 patients (group IV). Other laboratory parameters remained normal. The mean improvement in active pain visual analog scale (1.4, CI 0.5–2.22), WOMAC (functional activity questionnaire) pain score (1.37, CI 0.22–2.5), and urinary C-TAX (cartilage collagen breakdown product) assay was maximum (NS) in group IV. Lower dose group I showed numerically superior improvement compared with higher dose group II

  8. Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma

    PubMed Central

    Ducharme, Francine M; Ni Chroinin, Muireann; Greenstone, Ilana; Lasserson, Toby J

    2014-01-01

    Background In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled ß2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids. Objectives To determine the effect of the combination of long-acting ß2 agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the risk of asthma exacerbations, pulmonary function and on other measures of asthma control, and to look for characteristics associated with greater benefit for either treatment option. Search methods We identified randomised controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs, clinical trial registries and correspondence with manufacturers until May 2008. Selection criteria RCTs that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children and adults with asthma. Data collection and analysis Two authors independently assessed methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the number of patients experiencing one or more asthma exacerbations requiring oral corticosteroids. Main results This review included 48 studies (15,155 participants including 1155 children and 14,000 adults). Participants were inadequately controlled on their current ICS regimen, experiencing ongoing symptoms and with generally moderate (FEV1 60% to 79% of predicted) airway obstruction. The studies tested the combination of salmeterol or formoterol with a median dose of 400 mcg/day of beclomethasone or equivalent (BDP-eq) compared to a median of 1000 mcg/day of BDP-eq, usually for 24 weeks or less. There was a statistically significantly lower risk of exacerbations requiring systemic corticosteroids in patients treated with LABA and ICS

  9. Fixed-ratio schedules of cocaine self-administration in rhesus monkeys: joint control of responding by past and upcoming doses.

    PubMed

    Galuska, Chad M; Wade-Galuska, Tammy; Woods, James H; Winger, Gail

    2007-03-01

    By manipulating a signaled upcoming cocaine dose, we investigated how the dose just received and the upcoming dose jointly controlled cocaine self-administration. Three rhesus monkeys self-administered cocaine according to a multiple schedule differing in dose following completion of a fixed-ratio response requirement. The larger dose (0.03 or 0.056 mg/kg) was 10-fold higher than the smaller dose (0.003 or 0.0056 mg/kg). Following each infusion, there was an equal probability that the next dose would be large or small. This resulted in four types of signaled transitions: from a small dose to a small dose, small to large, large to large, and large to small. Across conditions the response requirement was increased. At lower ratios, pauses were brief and run rates were controlled by the upcoming dose. At larger ratios, pauses were pronounced, and run rates suppressed, in transitions from a large to a small dose. The behavioral disruption engendered by this transition occurred with both dose combinations. The results suggest that negative discriminable shifts in drug availability disrupt ongoing responding. PMID:17351424

  10. Effect of granulocyte colony-stimulating factor priming combined with low-dose cytarabine and homoharringtonine in higher risk myelodysplastic syndrome patients.

    PubMed

    Wang, Fang-Xia; Zhang, Wang-Gang; He, Ai-Li; Cao, Xin-Mei; Chen, Yin-Xia; Zhao, Wan-Hong; Yang, Yun; Wang, Jian-Li; Zhang, Peng-Yu; Gu, Liu-Fang

    2016-09-01

    As sensitization of leukemia cells with granulocyte colony-stimulating factor (G-CSF) can enhance the cytotoxicity of chemotherapy in myeloid malignancies, a pilot study was conducted in order to evaluate the effect of G-CSF priming combined with low-dose chemotherapy in patients with higher risk myelodysplastic syndrome (MDS). The regimen, G-HA, consisted of cytarabine (Ara-C) 7.5mg/m(2)/12h by subcutaneous injection, days 1-14, homoharringtonine (HHT) 1.5mg/m(2)/day by intravenous continuous infusion, days 1-14, and G-CSF 150mg/m(2)/day by subcutaneous injection, days 0-14. 56 patients were enrolled, 34 patients (61%, 95% confidence interval: 51.44-70.56%) achieved complete remission (CR). Median duration of neutropenia was 7days (ranging from 2 to 16days). Grade 1-2 nonhematologic toxicities were documented, including nausea and vomiting (5%), liver function abnormality (5%), and heart function abnormality (2%). No central nervous system toxicity was found. Mortality within the first 4 weeks was 4%. The G-HA regimen is effective in remission induction for higher risk MDS patients and well tolerated due to the acceptable toxicity in maintenance therapy in the patients who cannot undergo Hematopoietic cell transplantation (HCT). PMID:27497340

  11. Safety and Immunogenicity of Modified Vaccinia Ankara (ACAM3000): Effect of Dose and Route of Administration

    PubMed Central

    Wilck, Marissa B.; Seaman, Michael S.; Baden, Lindsey R.; Walsh, Stephen R.; Grandpre, Lauren E.; Devoy, Colleen; Giri, Ayush; Kleinjan, Jane A.; Noble, Lizanne C.; Stevenson, Kristen E.; Kim, Haesook T.; Dolin, Raphael

    2010-01-01

    Background We conducted a clinical trial of the safety and immunogenicity of Modified Vaccinia Ankara (ACAM3000 MVA) to examine the effects of dose and route of administration. Methods Seventy-two healthy, vaccinia-naïve subjects received one of six regimens of MVA or placebo in two administrations one month apart. Results MVA was generally well tolerated at all dose levels and by all routes. More pronounced local reactogenicity was seen by the intradermal (ID) and subcutaneous (SC) routes than by intramuscular (IM) administration. Binding antibodies to whole virus and neutralizing antibodies to IMV and EEV forms of vaccinia virus (VV) were elicited by all routes of MVA administration, and were greater for the higher dose by each route. Similar levels of neutralizing antibodies were seen at a ten-fold lower dose given ID (107 TCID50), compared to responses after 108 TCID50 given IM or SC. T-cell immune responses to VV were detected by IFN-γ ELISPOT, but had no clear relationship to dose or route. Conclusion These data suggest that ID immunization with MVA provides a dose sparing effect by eliciting antibody responses similar in magnitude and kinetics to those elicited by IM or SC routes, but at a 10-fold lower dose. PMID:20350191

  12. Radiotherapy Doses of 80 Gy and Higher Are Associated With Lower Mortality in Men With Gleason Score 8 to 10 Prostate Cancer

    SciTech Connect

    Pahlajani, Niraj; Ruth, Karen J.; Buyyounouski, Mark K.; Chen, David Y.T.; Horwitz, Eric M.; Hanks, Gerald E.; Price, Robert A.; Pollack, Alan

    2012-04-01

    Purpose: Men with Gleason score (GS) 8-10 prostate cancer (PCa) are assumed to have a high risk of micrometastatic disease at presentation. However, local failure is also a major problem. We sought to establish the importance of more aggressive local radiotherapy (RT) to {>=}80 Gy. Methods and Materials: There were 226 men treated consecutively with RT {+-} ADT from 1988 to 2002 for GS 8-10 PCa. Conventional, three-dimensional conformal or intensity-modulated (IM) RT was used. Radiation dose was divided into three groups: (1) <75 Gy (n = 50); (2) 75-79.9 Gy (n = 60); or (3) {>=}80 Gy (n = 116). The endpoints examined included biochemical failure (BF; nadir + 2 definition), distant metastasis (DM), cause-specific mortality, and overall mortality (OM). Results: Median follow-up was 66, 71, and 58 months for Groups 1, 2, and 3. On Fine and Gray's competing risk regression analysis, significant predictors of reduced BF were RT dose {>=}80 Gy (p = 0.011) and androgen deprivation therapy duration {>=}24 months (p = 0.033). In a similar model of DM, only RT dose {>=}80 Gy was significant (p = 0.007). On Cox regression analysis, significant predictors of reduced OM were RT dose {>=}80 Gy (p = 0.035) and T category (T3/4 vs. T1, p = 0.041). Dose was not a significant determinant of cause-specific mortality. Results for RT dose were similar in a model with RT dose and ADT duration as continuous variables. Conclusion: The results indicate that RT dose escalation to {>=}80 Gy is associated with lower risks of BF, DM, and OM in men with GS 8-10 PCa, independently of androgen deprivation therapy.

  13. Formation of DNA adducts and induction of mutations in rats treated with tumorigenic doses of 1,6-dinitropyrene

    SciTech Connect

    Beland, F.A.; Fullerton, N.F.; Smith, B.A.; Heflich, R.H.

    1994-10-01

    1,6-Dinitropyrene, a component of diesel exhaust, is a lung carcinogen in male F344 rats following a single intrapulmonary administration. In this study, rats were treated with tumorigenic doses of 1,6-dinitropyrene to establish dose-response relationships for the formation of DNA adducts in target (lung) and nontarget (liver) tissues and for the induction of 6-thioguanine-resistant mutations in spleen T-lymphocytes. One week after treatment with 0.3, 1, 3, 10, 30, 100, or 150 {mu}g of 1,6-dinitropyrene, dose-responsive DNA binding was measured in lung and liver with binding in the being 10-fold higher than in the liver. In the lung, a 2-fold increase in dose resulted in a 1.8-fold increase in DNA binding at treatments up to 30 {mu}g of 1,6-dinitropyrene, while in the liver, a 2-fold increase in 1,6-dinitropyrene produced a 2-fold increase in DNA binding at doses up to the 10 {mu}g treatment. Higher doses of 1,6-dinitropyrene resulted in proportionally smaller increases in adduct formation in the two tissues. When measured 21 weeks after treatment, mutations in T-lymphocytes increased with doses up to 100 {mu}g of 1,6-dinitropyrene, but the response was nonlinear throughout the dose range. These findings indicate that concentrations of 1,6-dinitropyrene that produce a dose-dependent induction of lung tumors also result in a dose-dependent formation of DNA adducts and induction of lymphocyte mutations but that the dose-response curves for DNA binding and mutations are different. 39 refs., 3 figs.

  14. Exposure to Hexavalent Chromium Resulted in Significantly Higher Tissue Chromium Burden Compared With Trivalent Chromium Following Similar Oral Doses to Male F344/N Rats and Female B6C3F1 Mice

    PubMed Central

    Collins, Bradley J.; Stout, Matthew D.; Levine, Keith E.; Kissling, Grace E.; Fennell, Timothy R.; Walden, Ramsey; Abdo, Kamal; Pritchard, John B.; Fernando, Reshan A.; Burka, Leo T.; Hooth, Michelle J.

    2010-01-01

    In National Toxicology Program 2-year studies, hexavalent chromium [Cr(VI)] administered in drinking water was clearly carcinogenic in male and female rats and mice, resulting in small intestine epithelial neoplasms in mice at a dose equivalent to or within an order of magnitude of human doses that could result from consumption of chromium-contaminated drinking water, assuming that dose scales by body weight3/4 (body weight raised to the 3/4 power). In contrast, exposure to trivalent chromium [Cr(III)] at much higher concentrations may have been carcinogenic in male rats but was not carcinogenic in mice or female rats. As part of these studies, total chromium was measured in tissues and excreta of additional groups of male rats and female mice. These data were used to infer the uptake and distribution of Cr(VI) because Cr(VI) is reduced to Cr(III) in vivo, and no methods are available to speciate tissue chromium. Comparable external doses resulted in much higher tissue chromium concentrations following exposure to Cr(VI) compared with Cr(III), indicating that a portion of the Cr(VI) escaped gastric reduction and was distributed systemically. Linear or supralinear dose responses of total chromium in tissues were observed following exposure to Cr(VI), indicating that these exposures did not saturate gastric reduction capacity. When Cr(VI) exposure was normalized to ingested dose, chromium concentrations in the liver and glandular stomach were higher in mice, whereas kidney concentrations were higher in rats. In vitro studies demonstrated that Cr(VI), but not Cr(III), is a substrate of the sodium/sulfate cotransporter, providing a partial explanation for the greater absorption of Cr(VI). PMID:20843897

  15. Estimation of β-ray dose in air and soil from Fukushima Daiichi Power Plant accident

    PubMed Central

    Endo, Satoru; Tanaka, Kenichi; Kajimoto, Tsuyoshi; Thanh, Nguyen Tat; Otaki, Joji M.; Imanaka, Tetsuji

    2014-01-01

    Following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident of 2011, which deposited radionuclides across Tohoku and northern Kanto, β-ray dose evaluation has been performed to estimate radiation exposure for small creatures like insects as well as human skin. Using the Monte Carlo radiation transport code MCNP-4C, we calculated the β-ray dose for 129mTe, 129Te, 131I, 132Te, 132I, 134Cs and 137Cs in air as a function of altitude and in soil. These calculations of β-dose rate for each radionuclide were conducted for the conditions following the FDNPP accident, with 137Cs deposition assumed to be 1000 kBq/m2. Beta-ray dose rate was found to be ∼10-fold (resp. 5-fold) higher than the γ-ray dose rate in the soil (resp. on the ground surface) at ∼20 days after deposition, and ∼4-fold (resp. 1.7-fold) higher after 6 months or more. For convenience, the height dependence of the ratio for 0, 10, 30, 90, 180 and 365 days after deposition was obtained by a fitting function. The cumulative 70 µm β-ray dose at 30, 60 and 90 days after deposition was estimated to be 35, 45 and 53 mGy for the ground surface, and 61, 79 and 92 mGy in the soil, respectively. These results can be used to estimate the external β-ray exposure for small creatures as well as for human skin. PMID:24504671

  16. Estimation of β-ray dose in air and soil from Fukushima Daiichi Power Plant accident.

    PubMed

    Endo, Satoru; Tanaka, Kenichi; Kajimoto, Tsuyoshi; Thanh, Nguyen Tat; Otaki, Joji M; Imanaka, Tetsuji

    2014-05-01

    Following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident of 2011, which deposited radionuclides across Tohoku and northern Kanto, β-ray dose evaluation has been performed to estimate radiation exposure for small creatures like insects as well as human skin. Using the Monte Carlo radiation transport code MCNP-4C, we calculated the β-ray dose for (129m)Te, (129)Te, (131)I, (132)Te, (132)I, (134)Cs and (137)Cs in air as a function of altitude and in soil. These calculations of β-dose rate for each radionuclide were conducted for the conditions following the FDNPP accident, with (137)Cs deposition assumed to be 1000 kBq/m(2). Beta-ray dose rate was found to be ∼10-fold (resp. 5-fold) higher than the γ-ray dose rate in the soil (resp. on the ground surface) at ∼20 days after deposition, and ∼4-fold (resp. 1.7-fold) higher after 6 months or more. For convenience, the height dependence of the ratio for 0, 10, 30, 90, 180 and 365 days after deposition was obtained by a fitting function. The cumulative 70 µm β-ray dose at 30, 60 and 90 days after deposition was estimated to be 35, 45 and 53 mGy for the ground surface, and 61, 79 and 92 mGy in the soil, respectively. These results can be used to estimate the external β-ray exposure for small creatures as well as for human skin. PMID:24504671

  17. SULT 1A3 single-nucleotide polymorphism and the single dose pharmacokinetics of inhaled salbutamol enantiomers: are some athletes at risk of higher urine levels?

    PubMed

    Jacobson, Glenn A; Yee, Kwang Choon; Wood-Baker, Richard; Walters, E Haydn

    2015-02-01

    The study was designed to investigate the effect of a common genetic variation of the main salbutamol metabolizing enzyme SULT1A3 (single nucleotide polymorphism 105A>G, rs1975350) on the stereoselective pharmacokinetics of salbutamol. Subjects were administered a 400 µg dose of inhaled salbutamol via a large volume spacer and blood samples were collected over 4 h. Plasma levels of (R)- and (S)-salbutamol were determined by an enantioselective liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. Twenty-five subjects with asthma were recruited and underwent SULT1A3 genotyping, from which four SNP homozygote (GG) subjects and nine wild-type (AA) subjects were selected to participated in the pharmacokinetic investigation. There were no differences in pharmacokinetic parameters (t1/2 , Cmax , AUC0-4h ) between SNP and wild-type genotypes for either the R- or S-enantiomer. Observed Cmax of R- and S-salbutamol [mean (SD)] was 0.64 (0.30) ng/mL and 1.32 (0.98) ng/mL, respectively. The mean t1/2 of R- and S-salbutamol was estimated at 2.94 (1.17) h and 7.86 (6.14) h respectively. The AUC0-4h of R- and S-salbutamol was 14.0 (6.8) and 38.3 (19.5) ng/mL.h respectively. In conclusion, the common SULT1A3 SNP 105A>G is not an important determinant of salbutamol enantiomer pharmacokinetics under normal clinical use and does not place some individuals at greater risk of accumulation in the body. PMID:24692077

  18. Biostability of polyether-urethane scaffolds: a comparison of two novel processing methods and the effect of higher gamma-irradiation dose.

    PubMed

    Haugen, H; Gerhardt, L C; Will, J; Wintermantel, E

    2005-05-01

    This article deals with enzyme-induced biodegradation behavior of thermoplastic polyether-urethane (TPU). Porous scaffolds were processed by a new foaming method applied in hot pressing and injection molding. The scaffolds were subsequently gamma sterilized. The samples were incubated with cholesterol esterase (CE) for 28 days to simulate an enzymatic degradation order to assess polymer biostability. The main focus of degradation products was the most toxic one: methylene dianiline (MDA). LC/MS was used to separate the breakdown products and to identify possible MDA amounts. The results showed that (a) the hot-pressed sample released an MDA amount almost twice as large (0.26 ng +/- 0.008) as that of the injection-molded samples (0.15 ng +/- 0.003) after incubation with enzyme activity in the physiological range, and (b) a tenfold increase in CE activity revealed considerably higher MDA amounts (7540.0 ng +/- 0.004). This enzyme concentration is physiologically unlikely, however, but may occur for extreme high inflammation behavior. Even for extremely high levels of CE enzyme, the scaffold will not discharge MDA above toxic levels. The injection-molded samples sterilized at 25 kGy seem to represent the most promising processing method. Therefore, the new injection-molding foaming process of polyether-urethane can be considered appropriate for use as a biomaterial. PMID:15756657

  19. H-ferritin–nanocaged doxorubicin nanoparticles specifically target and kill tumors with a single-dose injection

    PubMed Central

    Liang, Minmin; Fan, Kelong; Zhou, Meng; Duan, Demin; Zheng, Jiyan; Yang, Dongling; Feng, Jing; Yan, Xiyun

    2014-01-01

    An ideal nanocarrier for efficient drug delivery must be able to target specific cells and carry high doses of therapeutic drugs and should also exhibit optimized physicochemical properties and biocompatibility. However, it is a tremendous challenge to engineer all of the above characteristics into a single carrier particle. Here, we show that natural H-ferritin (HFn) nanocages can carry high doses of doxorubicin (Dox) for tumor-specific targeting and killing without any targeting ligand functionalization or property modulation. Dox-loaded HFn (HFn-Dox) specifically bound and subsequently internalized into tumor cells via interaction with overexpressed transferrin receptor 1 and released Dox in the lysosomes. In vivo in the mouse, HFn-Dox exhibited more than 10-fold higher intratumoral drug concentration than free Dox and significantly inhibited tumor growth after a single-dose injection. Importantly, HFn-Dox displayed an excellent safety profile that significantly reduced healthy organ drug exposure and improved the maximum tolerated dose by fourfold compared with free Dox. Moreover, because the HFn nanocarrier has well-defined morphology and does not need any ligand modification or property modulation it can be easily produced with high purity and yield, which are requirements for drugs used in clinical trials. Thus, these unique properties make the HFn nanocage an ideal vehicle for efficient anticancer drug delivery. PMID:25267615

  20. Effectiveness, Good Tolerability, and High Compliance of Doses of Risperidone Long-Acting Injectable Higher Than 75 mg in People With Severe Schizophrenia: A 3-Year Follow-Up.

    PubMed

    Fernández-Miranda, Juan J; Caramés-García, Victoria; Sánchez-García, Arantxa

    2015-12-01

    Tolerability and effectiveness of antipsychotics are important to increase treatment compliance in people with schizophrenia. The aim of this study was to evaluate effectiveness, tolerability, and adherence to treatment with high doses of risperidone long-acting injectable (RLAI) in patients with severe schizophrenia.It is a 3-year prospective, observational study of patients with severe (Clinical Global Impression Severity scale [CGI-S] score of ≥5) schizophrenia according to International Classification of Diseases (ICD-10) criteria. Subjects were the consecutive 60 who first underwent treatment with RLAI with doses of 75 mg or higher every 14 days to get clinical stabilization.Assessment included the following: CGI-S, World Health Organization Disability Assessment Schedule, Camberwell Assessment of Need (CAN), Medication Adherence Rating Scale, laboratory tests, weight, and hospital admissions.The mean (SD) dose of RLAI was 111.2 (9.1) mg per 14 days. Tolerability was good and there were almost no interruptions due to adverse effects or to relevant biological parameters alterations. Also, weight gain was not significant.Retention rate in treatment after 3 years was 95%. Clinical Global Impression Severity (P < 0.01) and Camberwell Assessment of Need (P < 0.01) decreased and also Disability Assessment Schedule in the 4 areas (P < 0.01). Medication Adherence Rating Scale score increased from 3.6 (0.7) to 8.9 (0.9) (P < 0.001). There were significantly few hospital admissions than during the previous 36 months (1.9 [1.3] vs 0.31 [0.2], P < 0.001).As a conclusion, we highlight that the effectiveness and tolerability of 75 mg or higher every 14 days of RLAI were high, being useful in improving treatment adherence in patients with severe schizophrenia, getting good clinical and functional outcomes. PMID:26421461

  1. Dose sculpting with generalized equivalent uniform dose

    SciTech Connect

    Wu Qiuwen; Djajaputra, David; Liu, Helen H.; Dong Lei; Mohan, Radhe; Wu, Yan

    2005-05-01

    With intensity-modulated radiotherapy (IMRT), a variety of user-defined dose distribution can be produced using inverse planning. The generalized equivalent uniform dose (gEUD) has been used in IMRT optimization as an alternative objective function to the conventional dose-volume-based criteria. The purpose of this study was to investigate the effectiveness of gEUD optimization to fine tune the dose distributions of IMRT plans. We analyzed the effect of gEUD-based optimization parameters on plan quality. The objective was to determine whether dose distribution to selected structures could be improved using gEUD optimization without adversely altering the doses delivered to other structures, as in sculpting. We hypothesized that by carefully defining gEUD parameters (EUD{sub 0} and n) based on the current dose distributions, the optimization system could be instructed to search for alternative solutions in the neighborhood, and we could maintain the dose distributions for structures already satisfactory and improve dose for structures that need enhancement. We started with an already acceptable IMRT plan optimized with any objective function. The dose distribution was analyzed first. For structures that dose should not be changed, a higher value of n was used and EUD{sub 0} was set slightly higher/lower than the EUD value at the current dose distribution for critical structures/targets. For structures that needed improvement in dose, a higher to medium value of n was used, and EUD{sub 0} was set to the EUD value or slightly lower/higher for the critical structure/target at the current dose distribution. We evaluated this method in one clinical case each of head and neck, lung and prostate cancer. Dose volume histograms, isodose distributions, and relevant tolerance doses for critical structures were used for the assessment. We found that by adjusting gEUD optimization parameters, the dose distribution could be improved with only a few iterations. A larger value of n

  2. Higher Biologically Effective Dose of Radiotherapy Is Associated With Improved Outcomes for Locally Advanced Non-Small Cell Lung Carcinoma Treated With Chemoradiation: An Analysis of the Radiation Therapy Oncology Group

    SciTech Connect

    Machtay, Mitchell; Movsas, Benjamin; Paulus, Rebecca; Gore, Elizabeth M.; Komaki, Ritsuko; Albain, Kathy; Sause, William T.; Curran, Walter J.

    2012-01-01

    Purpose: Patients treated with chemoradiotherapy for locally advanced non-small-cell lung carcinoma (LA-NSCLC) were analyzed for local-regional failure (LRF) and overall survival (OS) with respect to radiotherapy dose intensity. Methods and Materials: This study combined data from seven Radiation Therapy Oncology Group (RTOG) trials in which chemoradiotherapy was used for LA-NSCLC: RTOG 88-08 (chemoradiation arm only), 90-15, 91-06, 92-04, 93-09 (nonoperative arm only), 94-10, and 98-01. The radiotherapeutic biologically effective dose (BED) received by each individual patient was calculated, as was the overall treatment time-adjusted BED (tBED) using standard formulae. Heterogeneity testing was done with chi-squared statistics, and weighted pooled hazard ratio estimates were used. Cox and Fine and Gray's proportional hazard models were used for OS and LRF, respectively, to test the associations between BED and tBED adjusted for other covariates. Results: A total of 1,356 patients were analyzed for BED (1,348 for tBED). The 2-year and 5-year OS rates were 38% and 15%, respectively. The 2-year and 5-year LRF rates were 46% and 52%, respectively. The BED (and tBED) were highly significantly associated with both OS and LRF, with or without adjustment for other covariates on multivariate analysis (p < 0.0001). A 1-Gy BED increase in radiotherapy dose intensity was statistically significantly associated with approximately 4% relative improvement in survival; this is another way of expressing the finding that the pool-adjusted hazard ratio for survival as a function of BED was 0.96. Similarly, a 1-Gy tBED increase in radiotherapy dose intensity was statistically significantly associated with approximately 3% relative improvement in local-regional control; this is another way of expressing the finding that the pool-adjusted hazard ratio as a function of tBED was 0.97. Conclusions: Higher radiotherapy dose intensity is associated with improved local-regional control and

  3. Efficacy and toxicity of decitabine versus CHG regimen (low-dose cytarabine, homoharringtonine and granulocyte colony-stimulating factor) in patients with higher risk myelodysplastic syndrome: a retrospective study.

    PubMed

    Wu, Lingyun; Li, Xiao; Chang, Chunkang; Xu, Feng; He, Qi; Wu, Dong; Zhang, Zheng; Su, Jiying; Zhou, Liyu; Song, Luxi; Chao, Xiao; Zhao, Youshan

    2016-06-01

    Decitabine and CHG regimen (low-dose cytarabine and homoharringtonine with G-CSF) have been used for treating higher risk myelodysplastic syndrome (MDS). In this study, we retrospectively compared the efficacy and toxicity of the two regimens in 132 MDS patients. Complete remission (CR) was not significantly different between the groups (27.1% with decitabine vs. 30.6% with CHG, p = 0.657). The CR rate with decitabine (58.8%) was significantly higher than that with CHG (7.7%) (p = 0.007) among the patients with poor karyotypes. Five of 23 (21.7%) patients who failed to respond to decitabine achieved CR with CHG, while one of two patients achieved CR with decitabine after failure with CHG. Overall and relapse-free survival were not different between the groups. In conclusion, both decitabine and CHG regimen are effective for higher risk MDS; there is no cross resistance between the regimens. Decitabine might be a better choice for patients with poor karyotypes. PMID:26397697

  4. Protection of Eurasian badgers (Meles meles) from tuberculosis after intra-muscular vaccination with different doses of BCG.

    PubMed

    Lesellier, Sandrine; Palmer, Si; Gowtage-Sequiera, Sonya; Ashford, Roland; Dalley, Deanna; Davé, Dipesh; Weyer, Ute; Salguero, F Javier; Nunez, Alejandro; Crawshaw, Timothy; Corner, Leigh A L; Hewinson, R Glyn; Chambers, Mark A

    2011-05-12

    Mycobacterium bovis infection is widespread in Eurasian badger (Meles meles) populations in Great Britain and the Republic of Ireland where they act as a wildlife reservoir of infection for cattle. Removal of infected badgers can significantly reduce the incidence of bovine tuberculosis (TB) in local cattle herds. However, control measures based on culling of native wildlife are contentious and may even be detrimental to disease control. Vaccinating badgers with bacillus Calmette-Guerin (BCG) has been shown to be efficacious against experimentally induced TB of badgers when administered subcutaneously and orally. Vaccination may be an alternative or complementary strategy to other disease control measures. As the subcutaneous route is impractical for vaccinating wild badgers and an oral vaccine bait formulation is currently unavailable, we evaluated the intramuscular (IM) route of BCG administration. It has been demonstrated that the IM route is safe in badgers. IM administration has the practical advantage of being relatively easy to perform on trapped wild badgers without recourse to chemical immobilisation. We report the evaluation of the efficacy of IM administration of BCG Danish strain 1331 at two different doses: the dose prescribed for adult humans (2-8×10(5)colony forming units) and a 10-fold higher dose. Vaccination generated a dose-dependent cell-mediated immune response characterised by the production of interferon-γ (IFNγ) and protection against endobronchial challenge with virulent M. bovis. Protection, expressed in terms of a significant reduction in the severity of disease, the number of tissues containing acid-fast bacilli, and reduced bacterial excretion was statistically significant with the higher dose only. PMID:21440035

  5. Nicotine dose-concentration relationship and pregnancy outcomes in rat: biologic plausibility and implications for future research.

    PubMed

    Hussein, Jabeen; Farkas, Svetlana; MacKinnon, Yolanda; Ariano, Robert E; Sitar, Daniel S; Hasan, Shabih U

    2007-01-01

    Cigarette smoke (CS) exposure during pregnancy can lead to profound adverse effects on fetal development. Although CS contains several thousand chemicals, nicotine has been widely used as its surrogate as well as in its own right as a neuroteratogen. The justification for the route and dose of nicotine administration is largely based on inferential data suggesting that nicotine 6 mg/kg/day infused continuously via osmotic mini pumps (OMP) would mimic maternal CS exposure. We provide evidence that 6 mg/kg/day nicotine dose as commonly administered to pregnant rats leads to plasma nicotine concentrations that are 3-10-fold higher than those observed in moderate to heavy smokers and pregnant mothers, respectively. Furthermore, the cumulative daily nicotine dose exceeds by several hundred fold the amount consumed by human heavy smokers. Our study does not support the widely accepted notion that regardless of the nicotine dose, a linear nicotine dose-concentration relationship exists in a steady-state OMP model. We also show that total nicotine clearance increases with advancing pregnancy but no significant change is observed between the 2nd and 3rd trimester. Furthermore, nicotine infusion even at this extremely high dose has little effect on a number of maternal and fetal biologic variables and pregnancy outcome suggesting that CS constituents other than nicotine mediate the fetal growth restriction in infants born to smoking mothers. Our current study has major implications for translational research in developmental toxicology and pharmacotherapy using nicotine replacement treatment as an aid to cessation of cigarette smoking in pregnant mothers. PMID:17141291

  6. Nicotine dose-concentration relationship and pregnancy outcomes in rat: Biologic plausibility and implications for future research

    SciTech Connect

    Hussein, Jabeen; Farkas, Svetlana; MacKinnon, Yolanda; Ariano, Robert E.; Sitar, Daniel S.; Hasan, Shabih U. . E-mail: hasans@ucalgary.ca

    2007-01-01

    Cigarette smoke (CS) exposure during pregnancy can lead to profound adverse effects on fetal development. Although CS contains several thousand chemicals, nicotine has been widely used as its surrogate as well as in its own right as a neuroteratogen. The justification for the route and dose of nicotine administration is largely based on inferential data suggesting that nicotine 6 mg/kg/day infused continuously via osmotic mini pumps (OMP) would mimic maternal CS exposure. We provide evidence that 6 mg/kg/day nicotine dose as commonly administered to pregnant rats leads to plasma nicotine concentrations that are 3-10-fold higher than those observed in moderate to heavy smokers and pregnant mothers, respectively. Furthermore, the cumulative daily nicotine dose exceeds by several hundred fold the amount consumed by human heavy smokers. Our study does not support the widely accepted notion that regardless of the nicotine dose, a linear nicotine dose-concentration relationship exists in a steady-state OMP model. We also show that total nicotine clearance increases with advancing pregnancy but no significant change is observed between the 2nd and 3rd trimester. Furthermore, nicotine infusion even at this extremely high dose has little effect on a number of maternal and fetal biologic variables and pregnancy outcome suggesting that CS constituents other than nicotine mediate the fetal growth restriction in infants born to smoking mothers. Our current study has major implications for translational research in developmental toxicology and pharmacotherapy using nicotine replacement treatment as an aid to cessation of cigarette smoking in pregnant mothers.

  7. Absorbed Dose and Dose Equivalent Calculations for Modeling Effective Dose

    NASA Technical Reports Server (NTRS)

    Welton, Andrew; Lee, Kerry

    2010-01-01

    While in orbit, Astronauts are exposed to a much higher dose of ionizing radiation than when on the ground. It is important to model how shielding designs on spacecraft reduce radiation effective dose pre-flight, and determine whether or not a danger to humans is presented. However, in order to calculate effective dose, dose equivalent calculations are needed. Dose equivalent takes into account an absorbed dose of radiation and the biological effectiveness of ionizing radiation. This is important in preventing long-term, stochastic radiation effects in humans spending time in space. Monte carlo simulations run with the particle transport code FLUKA, give absorbed and equivalent dose data for relevant shielding. The shielding geometry used in the dose calculations is a layered slab design, consisting of aluminum, polyethylene, and water. Water is used to simulate the soft tissues that compose the human body. The results obtained will provide information on how the shielding performs with many thicknesses of each material in the slab. This allows them to be directly applicable to modern spacecraft shielding geometries.

  8. The use of safety or uncertainty factors in the setting of acute reference doses.

    PubMed

    Renwick, A G

    2000-07-01

    A 100-fold safety or uncertainty factor has been used for about 40 years to derive safe daily intakes for humans based on animal studies; the 100-fold factor comprises separate 10-fold factors to allow for species differences and inter-individual variability. Each factor has to allow for toxicokinetic and toxicodynamic differences. Sub-dividing the 10-fold factors into kinetic and dynamic defaults, which when multiplied give a product of 10, offers a number of advantages. The main rationale for this sub-division is so that chemical-specific data can be introduced to replace one or more of the default sub-factors, hence contributing to a chemical-related overall factor. However, sub-division of the 10-fold factors has allowed analysis of the appropriateness of the overall 10-fold defaults, and analysis of special situations, such as infants and children. The establishment of an acute reference dose based on animal studies has to allow for both species differences and inter-individual variability; comparison with the factors used for chronic effects suggests that modification of the usual defaults may be appropriate under certain specific circumstances, but that the usual default of 100 remains appropriate for most cases. PMID:10983588

  9. Circulating endothelial progenitor cells and residual in vivo thromboxane biosynthesis in low-dose aspirin-treated polycythemia vera patients.

    PubMed

    Santilli, Francesca; Romano, Mario; Recchiuti, Antonio; Dragani, Alfredo; Falco, Angela; Lessiani, Gianfranco; Fioritoni, Francesca; Lattanzio, Stefano; Mattoscio, Domenico; De Cristofaro, Raimondo; Rocca, Bianca; Davì, Giovanni

    2008-08-15

    Polycythemia vera (PV) is associated with high morbidity and mortality for thrombosis. We hypothesized that in PV altered sensitivity to aspirin might be related to dysfunction of the endothelial repair and/or of the nitric oxide (NO) system. Urinary thromboxane (TX) A(2) metabolite (TXM), endothelial colony-forming cells (ECFCs), plasma asymmetric dimethylarginine (ADMA) and von Willebrand factor (VWF) were measured in 37 PV patients on low-dose aspirin and 12 healthy controls. Patients showed an approximately 2-fold increase in median TXM and plasma ADMA levels (P < .001), while ECFC numbers were reduced by approximately 7-fold (P < .001) as compared with non-aspirinated control. These differences were more pronounced in patients with previous thrombosis. An 8-week course of aspirin did not affect ECFCs in 6 controls. VWF and TXM correlated directly with ADMA, and inversely with ECFCs. By multiple regression analysis, lower ECFC quartiles (beta = -0.39; SE = 0.17; P = .028) and higher VWF levels (beta = 0.338, SE = 0.002, P = .034) were independent predictors of higher TXM quartiles (R(2) = 0.39). Serum TXB(2), measured in 22 patients, was approximately 10-fold higher than aspirin-treated controls. PV patients appear to have an unbalanced ECFC/NO axis, and an apparent altered sensitivity of platelet TXA(2) production, all potentially contributing to aspirin-insensitive TXM formation. Thus, additional antithrombotic strategies may be beneficial in PV. PMID:18541722

  10. Multiple-dose acetaminophen pharmacokinetics.

    PubMed

    Sahajwalla, C G; Ayres, J W

    1991-09-01

    Four different treatments of acetaminophen (Tylenol) were administered in multiple doses to eight healthy volunteers. Each treatment (325, 650, 825, and 1000 mg) was administered five times at 6-h intervals. Saliva acetaminophen concentration versus time profiles were determined. Noncompartmental pharmacokinetic parameters were calculated and compared to determine whether acetaminophen exhibited linear or dose-dependent pharmacokinetics. For doses less than or equal to 18 mg/kg, area under the curve (AUC), half-life (t1/2), mean residence time (MRT), and ratio of AUC to dose for the first dose were compared with the last dose. No statistically significant differences were observed in dose-corrected AUC for the first or last dose among subjects or treatments. Half-lives and MRT were not significantly different among treatments for the first or the last dose. Statistically significant differences in t1/2 and MRT were noted (p less than 0.05) among subjects for the last dose. A plot of AUC versus dose for the first and the last doses exhibited a linear relationship. Dose-corrected saliva concentration versus time curves for the treatments were superimposable. Thus, acetaminophen exhibits linear pharmacokinetics for doses of 18 mg/kg or less. Plots of AUC versus dose for one subject who received doses higher than 18 mg/kg were curved, suggesting nonlinear behavior of acetaminophen in this subject. PMID:1800709

  11. Know your dose: RADDOSE

    PubMed Central

    Paithankar, Karthik S.; Garman, Elspeth F.

    2010-01-01

    The program RADDOSE is widely used to compute the dose absorbed by a macromolecular crystal during an X-ray diffraction experiment. A number of factors affect the absorbed dose, including the incident X-ray flux density, the photon energy and the composition of the macromolecule and of the buffer in the crystal. An experimental dose limit for macromolecular crystallography (MX) of 30 MGy at 100 K has been reported, beyond which the biological information obtained may be compromised. Thus, for the planning of an optimized diffraction experiment the estimation of dose has become an additional tool. A number of approximations were made in the original version of RADDOSE. Recently, the code has been modified in order to take into account fluorescent X-­ray escape from the crystal (version 2) and the inclusion of incoherent (Compton) scattering into the dose calculation is now reported (version 3). The Compton cross-section, although negligible at the energies currently commonly used in MX, should be considered in dose calculations for incident energies above 20 keV. Calculations using version 3 of RADDOSE reinforce previous studies that predict a reduction in the absorbed dose when data are collected at higher energies compared with data collected at 12.4 keV. Hence, a longer irradiation lifetime for the sample can be achieved at these higher energies but this is at the cost of lower diffraction intensities. The parameter ‘diffraction-dose efficiency’, which is the diffracted intensity per absorbed dose, is revisited in an attempt to investigate the benefits and pitfalls of data collection using higher and lower energy radiation, particularly for thin crystals. PMID:20382991

  12. Evolution of zinc, iron, and copper concentrations along the gastrointestinal tract of piglets weaned with or without in-feed high doses of zinc oxide compared to unweaned littermates.

    PubMed

    Davin, R; Manzanilla, E G; Klasing, K C; Pérez, J F

    2012-12-01

    High doses of ZnO are used to treat diarrhea in weaning pigs but are also an environmental concern. The mechanism of action of Zn against diarrhea is still not well understood. The amount of solubilized Zn, the relation of Zn with Fe and Cu, and the concentration of these elements in the gastrointestinal tract (GIT) are key data to understanding its mechanism of action and optimize its use. Therefore, we studied the Zn, Fe, and Cu concentrations in the GIT content of unweaned, weaned, and ZnO-treated pigs. Eight litters were used and 3 piglets were selected within each litter. Two piglets from each litter were weaned at 21 d of age and fed a commercial control diet (WCt) or WCt + 2000 mg/kg of Zn as ZnO (WZn). The third pig was kept unweaned (Uw) with the sow. All 24 pigs were killed at 28 d of age, GIT contents were sampled, soluble and insoluble fractions of the content were separated, and Zn, Fe, and Cu concentrations were analyzed. Concentration of Zn increased 3 to 5 fold along the GIT (2 to 10 fold in the soluble fraction) for weaned pigs on WZn compared to WCt and Uw pigs (P < 0.01 in all cases). The proportion of total Zn that was present in the soluble fraction was 4 to 10 folds higher in jejunum, ileum, and cecum of Uw pigs than in those weaned (P < 0.01 in all cases) but was not affected by ZnO treatment. Concentration of Fe in the soluble fraction was higher for Uw pigs compared to weaned pigs along the GIT (P < 0.05 in all cases) even when concentration in total content was lower for Uw pigs in stomach (P = 0.001) and jejunum (P = 0.029). Concentrations of Cu were lower in Uw pigs than in weaned pigs along the GIT (P < 0.05 in all cases). Surprisingly, animals on WZn showed a 5 to 10 fold increase of Cu solubilized in distal parts of the GIT (cecum and colon; P < 0.001) compared to other groups. Differences in Zn, Fe, and Cu concentrations found among treatments will be useful in future studies for understanding mechanism of action of ZnO and

  13. A combination of high dose rate (10X FFF/2400 MU/min/10 MV X-rays) and total low dose (0.5 Gy) induces a higher rate of apoptosis in melanoma cells in vitro and superior preservation of normal melanocytes.

    PubMed

    Sarojini, Sreeja; Pecora, Andrew; Milinovikj, Natasha; Barbiere, Joseph; Gupta, Saakshi; Hussain, Zeenathual M; Tuna, Mehmet; Jiang, Jennifer; Adrianzen, Laura; Jun, Jaewook; Catello, Laurice; Sanchez, Diana; Agarwal, Neha; Jeong, Stephanie; Jin, Youngjin; Remache, Yvonne; Goy, Andre; Ndlovu, Alois; Ingenito, Anthony; Suh, K Stephen

    2015-10-01

    The aim of this study was to determine the apoptotic effects, toxicity, and radiosensitization of total low dose irradiation delivered at a high dose rate in vitro to melanoma cells, normal human epidermal melanocytes (HEM), or normal human dermal fibroblasts (HDF) and to study the effect of mitochondrial inhibition in combination with radiation to enhance apoptosis in melanoma cells. Cells irradiated using 10X flattening filter-free (FFF) 10 MV X-rays at a dose rate of 400 or 2400 MU/min and a total dose of 0.25-8 Gy were analyzed by cell/colony counting, MitoTracker, MTT, and DNA-damage assays, as well as by quantitative real-time reverse transcriptase PCR in the presence or absence of mitochondrial respiration inhibitors. A dose rate of 2400 MU/min killed on average five-fold more melanoma cells than a dose rate 400 MU/min at a total dose of 0.5 Gy and preserved 80% survival of HEM and 90% survival of HDF. Increased apoptosis at the 2400 MU/min dose rate is mediated by greater DNA damage, reduced cell proliferation, upregulation of apoptotic genes, and downregulation of cell cycle genes. HEM and HDF were relatively unharmed at 2400 MU/min. Radiation induced upregulation of mitochondrial respiration in both normal and cancer cells, and blocking the respiration with inhibitors enhanced apoptosis only in melanoma cells. A high dose rate with a low total dose (2400 MU/min, 0.5 Gy/10X FFF 10 MV X-rays) enhances radiosensitivity of melanoma cells while reducing radiotoxicity toward HEM and HDF. Selective cytotoxicity of melanoma cells is increased by blocking mitochondrial respiration. PMID:26177150

  14. A combination of high dose rate (10X FFF/2400 MU/min/10 MV X-rays) and total low dose (0.5 Gy) induces a higher rate of apoptosis in melanoma cells in vitro and superior preservation of normal melanocytes

    PubMed Central

    Sarojini, Sreeja; Pecora, Andrew; Milinovikj, Natasha; Barbiere, Joseph; Gupta, Saakshi; Hussain, Zeenathual M.; Tuna, Mehmet; Jiang, Jennifer; Adrianzen, Laura; Jun, Jaewook; Catello, Laurice; Sanchez, Diana; Agarwal, Neha; Jeong, Stephanie; Jin, Youngjin; Remache, Yvonne; Goy, Andre; Ndlovu, Alois; Ingenito, Anthony

    2015-01-01

    The aim of this study was to determine the apoptotic effects, toxicity, and radiosensitization of total low dose irradiation delivered at a high dose rate in vitro to melanoma cells, normal human epidermal melanocytes (HEM), or normal human dermal fibroblasts (HDF) and to study the effect of mitochondrial inhibition in combination with radiation to enhance apoptosis in melanoma cells. Cells irradiated using 10X flattening filter-free (FFF) 10 MV X-rays at a dose rate of 400 or 2400 MU/min and a total dose of 0.25–8 Gy were analyzed by cell/colony counting, MitoTracker, MTT, and DNA-damage assays, as well as by quantitative real-time reverse transcriptase PCR in the presence or absence of mitochondrial respiration inhibitors. A dose rate of 2400 MU/min killed on average five-fold more melanoma cells than a dose rate 400 MU/min at a total dose of 0.5 Gy and preserved 80% survival of HEM and 90% survival of HDF. Increased apoptosis at the 2400 MU/min dose rate is mediated by greater DNA damage, reduced cell proliferation, upregulation of apoptotic genes, and downregulation of cell cycle genes. HEM and HDF were relatively unharmed at 2400 MU/min. Radiation induced upregulation of mitochondrial respiration in both normal and cancer cells, and blocking the respiration with inhibitors enhanced apoptosis only in melanoma cells. A high dose rate with a low total dose (2400 MU/min, 0.5 Gy/10X FFF 10 MV X-rays) enhances radiosensitivity of melanoma cells while reducing radiotoxicity toward HEM and HDF. Selective cytotoxicity of melanoma cells is increased by blocking mitochondrial respiration. PMID:26177150

  15. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.; Gregory, Dennis E.

    Decisions made by federal and state courts during 1983 concerning higher education are reported in this chapter. Issues of employment and the treatment of students underlay the bulk of the litigation. Specific topics addressed in these and other cases included federal authority to enforce regulations against age discrimination and to revoke an…

  16. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.

    Litigation in 1987 was very brisk with an increase in the number of higher education cases reviewed. Cases discussed in this chapter are organized under four major topics: (1) intergovernmental relations; (2) employees, involving discrimination claims, tenured and nontenured faculty, collective bargaining and denial of employee benefits; (3)…

  17. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.; Finnegan, Dorothy E.

    The higher education case law in 1988 is extensive. Cases discussed in this chapter are organized under five major topics: (1) intergovernmental relations; (2) employees, involving discrimination claims, tenured and nontenured faculty, collective bargaining, and denial of employee benefits; (3) students, involving admissions, financial aid, First…

  18. Higher Education.

    ERIC Educational Resources Information Center

    Hendrickson, Robert M.

    This eighth chapter of "The Yearbook of School Law, 1986" summarizes and analyzes over 330 state and federal court cases litigated in 1985 in which institutions of higher education were involved. Among the topics examined were relationships between postsecondary institutions and various governmental agencies; discrimination in the employment of…

  19. Higher unit dosage of psychotropic drugs.

    PubMed

    Burrell, C D

    1975-12-01

    The realities of the marketplace dictate that pharmaceutical companies seek to develop higher unit dosage forms. Technical problems not infrequently hinder such development. In low doses once-a-day medication with psychotropics is possible and practical. The potential for adverse reactions frequently renders it desirable to divide higher daily doses into two separate doses, one given in the morning and the other in the evening. PMID:1233527

  20. Artemether-lumefantrine nanostructured lipid carriers for oral malaria therapy: Enhanced efficacy at reduced dose and dosing frequency.

    PubMed

    Prabhu, Priyanka; Suryavanshi, Shital; Pathak, Sulabha; Sharma, Shobhona; Patravale, Vandana

    2016-09-10

    Artemether-lumefantrine (ARM-LFN) is a World Health Organization (WHO) approved fixed-dose combination having low solubility and poor oral bioavailability. Nanostructured lipid carriers (NLC) were developed to enhance the oral efficacy of this combination using the microemulsion template technique. They were characterized for drug content, entrapment efficiency, size distribution, in vitro release, antimalarial efficacy, and toxicity. The NLC showed sustained drug release. The recommended adult therapeutic dose is 80mg ARM and 480mg LFN (4 tablets) twice a day, which amounts to 160mg ARM and 960mg LFN daily. ARM-LFN NLC given once a day at 1/5 of therapeutic dose (16mg ARM and 96mg LFN) showed complete parasite clearance and 100% survival in Plasmodium berghei-infected mice. 33% of the mice treated with marketed tablets twice a day at the therapeutic dose showed late-stage recrudescence. Thus, NLC showed enhanced efficacy at 1/10 of the daily dose of ARM-LFN. The 10-fold reduced daily dose was formulated in two soft gelatin capsules thus reducing the number of units to be taken at a time by the patient. The capsules showed good stability at room temperature for a year. The NLC were found to be safe in rats. The biocompatible NLC developed using an industrially feasible technique offer a promising solution for oral malaria therapy. PMID:27421912

  1. Advantages of Efficacy and Safety of Fixed-Dose Tafluprost/Timolol Combination Over Fixed-Dose Latanoprost/Timolol Combination

    PubMed Central

    Fuwa, Masahiro; Ueda, Kenji; Akaishi, Takahiro; Yamashita, Naoko; Kirihara, Tomoko; Shimazaki, Atsushi; Mano, Hidetoshi; Kawazu, Kouichi

    2016-01-01

    Purpose To compare the safety and efficacy of fixed-dose tafluprost/timolol combination (Taf/T-FDC) with those of fixed-dose latanoprost/timolol combination (Lat/T-FDC) by measuring the intraocular pressure (IOP)-lowering effect, ocular pharmacokinetics, and ocular surface toxicity. Methods The IOP-lowering effect of Taf/T-FDC and Lat/T-FDC in ocular normotensive monkeys was evaluated at 4 and 8 h after instillation in study A, at 12, 14, 16, and 18 h after instillation in study B, and at 24, 26, 28, and 30 h after instillation in study C. Drug penetration into the eye was evaluated by measuring the concentrations of timolol, tafluprost acid (active metabolic form of tafluprost), and latanoprost acid (active metabolic form of latanoprost) using liquid chromatography coupled with tandem mass spectrometry after single instillation of Taf/T-FDC or Lat/T-FDC to Sprague Dawley rats. Cytotoxicity following 1–30 min exposure of SV40-transformed human corneal epithelial cells to Taf/T-FDC or Lat/T-FDC was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays. Undiluted and 10-fold diluted solutions of each FDC were evaluated. Results The IOP-lowering effect of Taf/T-FDC was almost equivalent to that of Lat/T-FDC at 4–8 h after instillation. The peak IOP reduction of Taf/T-FDC and Lat/T-FDC was observed at 8 h after instillation, and there is no difference between the two. The difference between them was observed at 24–30 h after instillation, and Taf/T-FDC demonstrated a significantly greater IOP-lowering effect than Lat/T-FDC at 24–30 h after instillation. The IOP-lowering effect of Taf/T-FDC was sustained up to 30 h after instillation, while that of Lat/T-FDC had almost disappeared at 28 h after instillation. Timolol concentrations in aqueous humor after Taf/T-FDC instillation were higher than those after Lat/T-FDC instillation (Cmax, 3870 ng/mL vs 1330 ng/mL; AUCinf, 3970 ng·h/mL vs 1250 ng·h/mL). The

  2. Dose audit failures and dose augmentation

    NASA Astrophysics Data System (ADS)

    Herring, C.

    1999-01-01

    Standards EN 552 and ISO 11137, covering radiation sterilization, are technically equivalent in their requirements for the selection of the sterilization dose. Dose Setting Methods 1 and 2 described in Annex B of ISO 11137 can be used to meet these requirements for the selection of the sterilization dose. Both dose setting methods require a dose audit every 3 months to determine the continued validity of the sterilization dose. This paper addresses the subject of dose audit failures and investigations into their cause. It also presents a method to augment the sterilization dose when the number of audit positives exceeds the limits imposed by ISO 11137.

  3. Gamma Radiation Doses In Sweden

    NASA Astrophysics Data System (ADS)

    Almgren, Sara; Barregârd, Lars; Isaksson, Mats

    2008-08-01

    Gamma dose rate measurements were performed in one urban and one rural area using thermoluminescence dosimeters (TLD) worn by 46 participants and placed in their dwellings. The personal effective dose rates were 0.096±0.019(1 SD) and 0.092±0.016(1 SD)μSv/h in the urban and rural area, respectively. The corresponding dose rates in the dwellings were 0.11±0.042(1 SD) and 0.091±0.026(1 SD)μSv/h. However, the differences between the areas were not significant. The values were higher in buildings made of concrete than of wood and higher in apartments than in detached houses. Also, 222Rn measurements were performed in each dwelling, which showed no correlation with the gamma dose rates in the dwellings.

  4. Gamma Radiation Doses In Sweden

    SciTech Connect

    Almgren, Sara; Isaksson, Mats; Barregaard, Lars

    2008-08-07

    Gamma dose rate measurements were performed in one urban and one rural area using thermoluminescence dosimeters (TLD) worn by 46 participants and placed in their dwellings. The personal effective dose rates were 0.096{+-}0.019(1 SD) and 0.092{+-}0.016(1 SD){mu}Sv/h in the urban and rural area, respectively. The corresponding dose rates in the dwellings were 0.11{+-}0.042(1 SD) and 0.091{+-}0.026(1 SD){mu}Sv/h. However, the differences between the areas were not significant. The values were higher in buildings made of concrete than of wood and higher in apartments than in detached houses. Also, {sup 222}Rn measurements were performed in each dwelling, which showed no correlation with the gamma dose rates in the dwellings.

  5. Low Dose Effects in Psychopharmacology: Ontogenetic Considerations

    PubMed Central

    Spear, Linda Patia; Varlinskaya, Elena I.

    2005-01-01

    Low doses of psychoactive drugs often elicit a behavioral profile opposite to that observed following administration of more substantial doses. Our laboratory has observed that these effects are often age-specific in rats. For instance, whereas moderate to high doses of the dopamine agonist apomorphine increase locomotion, suppressed locomotor activity is seen following low dose exposure, with this low dose effect not emerging consistently until adolescence. A somewhat earlier emergence of a low dose “paradoxical” effect is seen with the 5HT1a receptor agonist, 8-OH-DPAT, with late preweanling, but not neonatal, rats showing increases in ingestive behavior at low doses but suppression at higher doses. In contrast to these ontogenetic increases in expression of low dose drug effects, low dose facilitation of social behavior is seen following ethanol only in adolescent rats and not their mature counterparts, although suppression of social interactions at higher doses is seen at both ages. This hormesis-like low dose stimulation appears related in part to overcompensation, with brief social suppression preceding the subsequent stimulation response, and also bears a number of ontogenetic similarities to acute tolerance, a well characterized, rapidly emerging adaptation to ethanol. Implications of these and other ontogenetic findings for studies of hormesis are discussed. PMID:19330157

  6. Dose management in CT facility

    PubMed Central

    Tsapaki, V; Rehani, M

    2007-01-01

    Computed Tomography (CT) examinations have rapidly increased in number over the last few years due to recent advances such as the spiral, multidetector-row, CT fluoroscopy and Positron Emission Tomography (PET)-CT technology. This has resulted in a large increase in collective radiation dose as reported by many international organisations. It is also stated that frequently, image quality in CT exceeds the level required for confident diagnosis. This inevitably results in patient radiation doses that are higher than actually required, as also stressed by the US Food and Drug Administration (FDA) regarding the CT exposure of paediatric and small adult patients. However, the wide range in exposure parameters reported, as well as the different CT applications reveal the difficulty in standardising CT procedures. The purpose of this paper is to review the basic CT principles, outline the recent technological advances and their impact in patient radiation dose and finally suggest methods of radiation dose optimisation. PMID:21614279

  7. Patient dose measurements in diagnostic radiology procedures in Korea.

    PubMed

    Kim, You-hyun; Choi, Jong-hak; Kim, Chang-kyun; Kim, Jung-min; Kim, Sung-soo; Oh, Yu-whan; Lee, Chang-yeap; Kang, Dae-hyun; Lee, Young-bae; Cho, Pyong-kon; Kim, Hyung-chul; Kim, Chel-min

    2007-01-01

    This study is the first nationwide investigation aimed at estimating the patient dose for radiographic examinations in Korea including gastrointestinal studies, computed tomography and mammography. The survey data from 161 hospitals and the dose data from 32 hospitals were analysed. The third quartile entrance surface dose, dose area product (DAP), weighted CT dose index (CTDIw) and mean glandular dose (MGD) were reported. All the estimated doses were less than the stated International Atomic Energy Agency (IAEA) reference levels for radiographic examinations. However, DAPs for the fluoroscopic examinations had higher dose values than the IAEA reference levels. In addition, the CTDIw and MGD were lower than the IAEA reference levels. PMID:17223642

  8. Peripheral doses from pediatric IMRT

    SciTech Connect

    Klein, Eric E.; Maserang, Beth; Wood, Roy; Mansur, David

    2006-07-15

    Peripheral dose (PD) data exist for conventional fields ({>=}10 cm) and intensity-modulated radiotherapy (IMRT) delivery to standard adult-sized phantoms. Pediatric peripheral dose reports are limited to conventional therapy and are model based. Our goal was to ascertain whether data acquired from full phantom studies and/or pediatric models, with IMRT treatment times, could predict Organ at Risk (OAR) dose for pediatric IMRT. As monitor units (MUs) are greater for IMRT, it is expected IMRT PD will be higher; potentially compounded by decreased patient size (absorption). Baseline slab phantom peripheral dose measurements were conducted for very small field sizes (from 2 to 10 cm). Data were collected at distances ranging from 5 to 72 cm away from the field edges. Collimation was either with the collimating jaws or the multileaf collimator (MLC) oriented either perpendicular or along the peripheral dose measurement plane. For the clinical tests, five patients with intracranial or base of skull lesions were chosen. IMRT and conventional three-dimensional (3D) plans for the same patient/target/dose (180 cGy), were optimized without limitation to the number of fields or wedge use. Six MV, 120-leaf MLC Varian axial beams were used. A phantom mimicking a 3-year-old was configured per Center for Disease Control data. Micro (0.125 cc) and cylindrical (0.6 cc) ionization chambers were appropriated for the thyroid, breast, ovaries, and testes. The PD was recorded by electrometers set to the 10{sup -10} scale. Each system set was uniquely calibrated. For the slab phantom studies, close peripheral points were found to have a higher dose for low energy and larger field size and when MLC was not deployed. For points more distant from the field edge, the PD was higher for high-energy beams. MLC orientation was found to be inconsequential for the small fields tested. The thyroid dose was lower for IMRT delivery than that predicted for conventional (ratio of IMRT/cnventional ranged

  9. Evaluation of Rectal Dose During High-Dose-Rate Intracavitary Brachytherapy for Cervical Carcinoma

    SciTech Connect

    Sha, Rajib Lochan; Reddy, Palreddy Yadagiri; Rao, Ramakrishna; Muralidhar, Kanaparthy R.; Kudchadker, Rajat J.

    2011-01-01

    High-dose-rate intracavitary brachytherapy (HDR-ICBT) for carcinoma of the uterine cervix often results in high doses being delivered to surrounding organs at risk (OARs) such as the rectum and bladder. Therefore, it is important to accurately determine and closely monitor the dose delivered to these OARs. In this study, we measured the dose delivered to the rectum by intracavitary applications and compared this measured dose to the International Commission on Radiation Units and Measurements rectal reference point dose calculated by the treatment planning system (TPS). To measure the dose, we inserted a miniature (0.1 cm{sup 3}) ionization chamber into the rectum of 86 patients undergoing radiation therapy for cervical carcinoma. The response of the miniature chamber modified by 3 thin lead marker rings for identification purposes during imaging was also characterized. The difference between the TPS-calculated maximum dose and the measured dose was <5% in 52 patients, 5-10% in 26 patients, and 10-14% in 8 patients. The TPS-calculated maximum dose was typically higher than the measured dose. Our study indicates that it is possible to measure the rectal dose for cervical carcinoma patients undergoing HDR-ICBT. We also conclude that the dose delivered to the rectum can be reasonably predicted by the TPS-calculated dose.

  10. Benchmark Dose Modeling

    EPA Science Inventory

    Finite doses are employed in experimental toxicology studies. Under the traditional methodology, the point of departure (POD) value for low dose extrapolation is identified as one of these doses. Dose spacing necessarily precludes a more accurate description of the POD value. ...

  11. Reevaluation of the newborn thyroid dose from radioiodines

    SciTech Connect

    Hedrick, W.R.; Milavickas, L.R.

    1987-07-01

    The basis for the current thyroid absorbed dose estimates for radioiodines has been examined. The values for the newborn thyroid dose were found to underestimate the dose by a factor of 3. This underestimation of the dose was caused by the assumption that the biokinetic distribution of iodine is the same for the newborn and the adult. Increased thyroid uptake by the newborn requires that higher cumulated activities be incorporated into the dose determinations for the newborn.

  12. Higher Education Exchange, 2014

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2014-01-01

    Research shows that not only does higher education not see the public; when the public, in turn, looks at higher education, it sees mostly malaise, inefficiencies, expense, and unfulfilled promises. Yet, the contributors to this issue of the "Higher Education Exchange" tell of bright spots in higher education where experiments in working…

  13. Higher Education Exchange, 2008

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2008-01-01

    "Higher Education Exchange" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education Exchange" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…

  14. Higher Education Exchange, 2010

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2010-01-01

    "Higher Education Exchange" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education Exchange" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…

  15. Higher Education Exchange, 2011

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2011-01-01

    "Higher Education Exchange" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education Exchange" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…

  16. Higher Education Exchange, 2012

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2012-01-01

    "Higher Education Exchange" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education Exchange" examine whether institutions of higher learning are doing anything to increase the capacity of citizens to shape their future.…

  17. Use of effective dose.

    PubMed

    Harrison, J D; Balonov, M; Martin, C J; Ortiz Lopez, P; Menzel, H-G; Simmonds, J R; Smith-Bindman, R; Wakeford, R

    2016-06-01

    International Commission on Radiological Protection (ICRP) Publication 103 provided a detailed explanation of the purpose and use of effective dose and equivalent dose to individual organs and tissues. Effective dose has proven to be a valuable and robust quantity for use in the implementation of protection principles. However, questions have arisen regarding practical applications, and a Task Group has been set up to consider issues of concern. This paper focusses on two key proposals developed by the Task Group that are under consideration by ICRP: (1) confusion will be avoided if equivalent dose is no longer used as a protection quantity, but regarded as an intermediate step in the calculation of effective dose. It would be more appropriate for limits for the avoidance of deterministic effects to the hands and feet, lens of the eye, and skin, to be set in terms of the quantity, absorbed dose (Gy) rather than equivalent dose (Sv). (2) Effective dose is in widespread use in medical practice as a measure of risk, thereby going beyond its intended purpose. While doses incurred at low levels of exposure may be measured or assessed with reasonable reliability, health effects have not been demonstrated reliably at such levels but are inferred. However, bearing in mind the uncertainties associated with risk projection to low doses or low dose rates, it may be considered reasonable to use effective dose as a rough indicator of possible risk, with the additional consideration of variation in risk with age, sex and population group. PMID:26980800

  18. ELDRS Characterization for a Very High Dose Mission

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  19. High-Dose Atomoxetine Treatment of ADHD in Youths with Limited Response to Standard Doses

    ERIC Educational Resources Information Center

    Kratochvil, Christopher J.; Michelson, David; Newcorn, Jeffrey H.; Weiss, Margaret D.; Busner, Joan; Moore, Rodney J.; Ruff, Dustin D.; Ramsey, Janet; Dickson, Ruth; Turgay, Atilla; Saylor, Keith E.; Luber, Stephen; Vaughan, Brigette; Allen, Albert J.

    2007-01-01

    Objective: To assess the utility and tolerability of higher than standard atomoxetine doses to treat attention-deficit/hyperactivity disorder (ADHD). Method: Two randomized, double-blind trials of atomoxetine nonresponders ages 6 to 16 years were conducted comparing continued treatment with same-dose atomoxetine to treatment using greater than…

  20. Optimal Dose of Vitamin D3 400 I.U. for Average Adults has A Significant Anti-Cancer Effect, While Widely Used 2000 I.U. or Higher Promotes Cancer: Marked Reduction of Taurine & 1α, 25(OH)2D3 Was Found In Various Cancer Tissues and Oral Intake of Optimal Dose of Taurine 175mg for Average Adults, Rather Than 500mg, Was Found to Be A New Potentially Safe and More Effective Method of Cancer Treatment.

    PubMed

    Omura, Yoshiaki; Lu, Dominic; Jones, Marilyn K; Nihrane, Abdallah; Duvvi, Harsha; Yapor, Dario; Shimotsuura, Yasuhiro; Ohki, Motomu

    2016-01-01

    During the past 10 years, the author had found that the optimal dose of Vitamin D3 400 I.U. has safe & effective anticancer effects, while commonly used 2000-5000 I.U. of Vit. D3 often creates a 2-3 time increase in cancer markers. We examined the concentration of Taurine in normal internal organs and in cancer using Bi-Digital O-Ring Test. We found that Taurine levels in normal tissue are 4-6ng. But, the amount of Taurine of average normal value of 5.0-5.25ng was strikingly reduced to 0.0025-0.0028ng in this study of several examples in adenocarcinomas of the esophagus, stomach, pancreas, colon, prostate, and lung, as well as breast cancer. The lowest Taurine levels of 0.0002-0.0005ng were found in so called Zika virus infected babies from Brazil with microcephaly. While Vitamin D3 receptor stimulant 1α, 25 (OH)2D3 in normal tissues was 0.45-0.53ng, they were reduced to 0.025-0.006ng in cancers (1/100th-1/200th of normal value), particularly in various adenocarcinomas. All of these adenocarcinomas had about 1500ng HPV-16 viral infection. In 500 breast cancers, about 97% had HPV-16. The optimal dose of Taurine for average adult has been found to be about 175mg, rather than the widely used 500mg. In addition, since Taurine is markedly reduced to close to 1/1000th-1/2000th of its normal value in these cancer tissues, we examined the effect of the optimal dose of Taurine on cancer patients. Optimal dose of Taurine produced a very significant decrease in cancer-associated parameters, such as Oncogene C-fosAb2 & Integrin α5β1 being reduced to less than 1/1,000th, and 8-OH-dG (which increases in the presence of DNA mutation) reduced to less than 1/10th. The optimal dose of Taurine 175mg for average adult various cancer patient 3 times a day alone provide beneficial effects with very significant anti-cancer effects with strikingly increased urinary excretion of bacteria, viruses, & funguses, asbestos, toxic metals & other toxic substances. However, optimal doses of

  1. Failure-probability driven dose painting

    SciTech Connect

    Vogelius, Ivan R.; Håkansson, Katrin; Due, Anne K.; Aznar, Marianne C.; Kristensen, Claus A.; Rasmussen, Jacob; Specht, Lena; Berthelsen, Anne K.; Bentzen, Søren M.

    2013-08-15

    Purpose: To demonstrate a data-driven dose-painting strategy based on the spatial distribution of recurrences in previously treated patients. The result is a quantitative way to define a dose prescription function, optimizing the predicted local control at constant treatment intensity. A dose planning study using the optimized dose prescription in 20 patients is performed.Methods: Patients treated at our center have five tumor subvolumes from the center of the tumor (PET positive volume) and out delineated. The spatial distribution of 48 failures in patients with complete clinical response after (chemo)radiation is used to derive a model for tumor control probability (TCP). The total TCP is fixed to the clinically observed 70% actuarial TCP at five years. Additionally, the authors match the distribution of failures between the five subvolumes to the observed distribution. The steepness of the dose–response is extracted from the literature and the authors assume 30% and 20% risk of subclinical involvement in the elective volumes. The result is a five-compartment dose response model matching the observed distribution of failures. The model is used to optimize the distribution of dose in individual patients, while keeping the treatment intensity constant and the maximum prescribed dose below 85 Gy.Results: The vast majority of failures occur centrally despite the small volumes of the central regions. Thus, optimizing the dose prescription yields higher doses to the central target volumes and lower doses to the elective volumes. The dose planning study shows that the modified prescription is clinically feasible. The optimized TCP is 89% (range: 82%–91%) as compared to the observed TCP of 70%.Conclusions: The observed distribution of locoregional failures was used to derive an objective, data-driven dose prescription function. The optimized dose is predicted to result in a substantial increase in local control without increasing the predicted risk of toxicity.

  2. Perchlorate exposure and dose estimates in infants.

    PubMed

    Valentín-Blasini, Liza; Blount, Benjamin C; Otero-Santos, Samaret; Cao, Yang; Bernbaum, Judy C; Rogan, Walter J

    2011-05-01

    Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however, little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1-377 days and calculated perchlorate intake dose for this sample of infants. The median estimated exposure dose for this sample of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p < 0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p < 0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects. PMID:21449579

  3. Perchlorate exposure and dose estimates in infants

    PubMed Central

    Valentín-Blasini, Liza; Blount, Benjamin C.; Otero-Santos, Samaret; Cao, Yang; Bernbaum, Judy C.; Rogan, Walter J.

    2011-01-01

    Perchlorate is a naturally occurring inorganic anion used as a component of solid rocket fuel, explosives, and pyrotechnics. Sufficiently high perchlorate intakes can modify thyroid function by competitively inhibiting iodide uptake in adults; however little is known about perchlorate exposure and health effects in infants. Food intake models predict that infants have higher perchlorate exposure doses than adults. For this reason, we measured perchlorate and related anions (nitrate, thiocyanate, and iodide) in 206 urine samples from 92 infants ages 1–377 days and calculated perchlorate intake dose for this population of infants. The median estimated exposure dose for this population of infants was 0.160 μg/kg/day. Of the 205 individual dose estimates, 9% exceeded the reference dose of 0.7 μg/kg/day; 6% of infants providing multiple samples had multiple perchlorate dose estimates above the reference dose. Estimated exposure dose differed by feeding method: breast-fed infants had a higher perchlorate exposure dose (geometric mean 0.220 μg/kg/day) than infants consuming cow milk-based formula (geometric mean 0.103 μg/kg/day, p<0.0001) or soy-based formula (geometric mean 0.027 μg/kg/day, p<0.0001), consistent with dose estimates based on dietary intake data. The ability of perchlorate to block adequate iodide uptake by the thyroid may have been reduced by the iodine-sufficient status of the infants studied (median urinary iodide 125 μg/L). Further research is needed to see whether these perchlorate intake doses lead to any health effects. PMID:21449579

  4. Special Higher Education Bibliography.

    ERIC Educational Resources Information Center

    Weinberg, Meyer

    1982-01-01

    Cites works relevant to the higher education of Blacks and minority group members. Lists references alphabetically under the following headings: (1) financial aid on the campus; (2) Chicanos in higher education; and (3) race and equality on California campuses. (GC)

  5. Oncogenic transformation through the cell cycle and the LET dependent inverse dose rate effect

    NASA Technical Reports Server (NTRS)

    Geard, C. R.; Miller, R. C.; Brenner, D. J.; Hall, E. J.; Wachholz, B. W. (Principal Investigator)

    1994-01-01

    Synchronised populations of mouse C3H/10T-1/2 cells were obtained by a stringent mitotic dislodgment procedure. Mitotic cells rapidly attach and progress sequentially through the cell cycle. Irradiation (3 Gy of X rays) was carried out at intervals from 0 to 18 h after initiating cell cycle progression of the mitotic cells. Oncogenic transformation was enhanced 10-fold over cells irradiated soon after replating (G1 and S phases) for cells in a near 2 h period corresponding to cells in G2 phase but not in mitosis. The cell surviving fraction had a 2-1/2-fold variation with resistant peaks corresponding to the late G1 and late S phases. These findings provide experimental support for the hypothesis initiated by Rossi and Kellerer and developed by Brenner and Hall to explain the LET dependent inverse dose rate effect for oncogenic transformation.

  6. Spotlight on Higher Education.

    ERIC Educational Resources Information Center

    Klinger, Donna; Iwanowski, Jay

    1997-01-01

    A number of current issues and initiatives in higher education are highlighted, including impending reauthorization of the Higher Education Act, the need for advocacy of higher education in public policy arenas, a University of Florida program combining accountability and institutional autonomy, and institutional compliance with nonresident alien…

  7. Higher Education Exchange, 2007

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2007-01-01

    "Higher Education Exchange" publishes case studies, analyses, news, and ideas about efforts within higher education to develop more democratic societies. Contributors to this issue of the "Higher Education Exchange" discuss the concept of growing public scholars; each contribution incorporates a student component. Articles include: (1) "Foreword"…

  8. The Higher Education Enterprise.

    ERIC Educational Resources Information Center

    Ottinger, Cecilia A.

    1991-01-01

    Higher education not only contributes to the development of the human resources and intellectual betterment of the nation but is also a major economic enterprise. This research brief reviews and highlights data on the size and growth of higher education and illustrates how higher education institutions are preparing the future labor force. It…

  9. Hormones and Endocrine-Disrupting Chemicals: Low-Dose Effects and Nonmonotonic Dose Responses

    PubMed Central

    Colborn, Theo; Hayes, Tyrone B.; Heindel, Jerrold J.; Jacobs, David R.; Lee, Duk-Hee; Shioda, Toshi; Soto, Ana M.; vom Saal, Frederick S.; Welshons, Wade V.; Zoeller, R. Thomas

    2012-01-01

    For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of “the dose makes the poison,” because EDCs can have effects at low doses that are not predicted by effects at higher doses. Here, we review two major concepts in EDC studies: low dose and nonmonotonicity. Low-dose effects were defined by the National Toxicology Program as those that occur in the range of human exposures or effects observed at doses below those used for traditional toxicological studies. We review the mechanistic data for low-dose effects and use a weight-of-evidence approach to analyze five examples from the EDC literature. Additionally, we explore nonmonotonic dose-response curves, defined as a nonlinear relationship between dose and effect where the slope of the curve changes sign somewhere within the range of doses examined. We provide a detailed discussion of the mechanisms responsible for generating these phenomena, plus hundreds of examples from the cell culture, animal, and epidemiology literature. We illustrate that nonmonotonic responses and low-dose effects are remarkably common in studies of natural hormones and EDCs. Whether low doses of EDCs influence certain human disorders is no longer conjecture, because epidemiological studies show that environmental exposures to EDCs are associated with human diseases and disabilities. We conclude that when nonmonotonic dose-response curves occur, the effects of low doses cannot be predicted by the effects observed at high doses. Thus, fundamental changes in chemical testing and safety determination are needed to protect human health. PMID:22419778

  10. Hormones and endocrine-disrupting chemicals: low-dose effects and nonmonotonic dose responses.

    PubMed

    Vandenberg, Laura N; Colborn, Theo; Hayes, Tyrone B; Heindel, Jerrold J; Jacobs, David R; Lee, Duk-Hee; Shioda, Toshi; Soto, Ana M; vom Saal, Frederick S; Welshons, Wade V; Zoeller, R Thomas; Myers, John Peterson

    2012-06-01

    For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of "the dose makes the poison," because EDCs can have effects at low doses that are not predicted by effects at higher doses. Here, we review two major concepts in EDC studies: low dose and nonmonotonicity. Low-dose effects were defined by the National Toxicology Program as those that occur in the range of human exposures or effects observed at doses below those used for traditional toxicological studies. We review the mechanistic data for low-dose effects and use a weight-of-evidence approach to analyze five examples from the EDC literature. Additionally, we explore nonmonotonic dose-response curves, defined as a nonlinear relationship between dose and effect where the slope of the curve changes sign somewhere within the range of doses examined. We provide a detailed discussion of the mechanisms responsible for generating these phenomena, plus hundreds of examples from the cell culture, animal, and epidemiology literature. We illustrate that nonmonotonic responses and low-dose effects are remarkably common in studies of natural hormones and EDCs. Whether low doses of EDCs influence certain human disorders is no longer conjecture, because epidemiological studies show that environmental exposures to EDCs are associated with human diseases and disabilities. We conclude that when nonmonotonic dose-response curves occur, the effects of low doses cannot be predicted by the effects observed at high doses. Thus, fundamental changes in chemical testing and safety determination are needed to protect human health. PMID:22419778

  11. Occupational radiation doses during interventional procedures

    NASA Astrophysics Data System (ADS)

    Nuraeni, N.; Hiswara, E.; Kartikasari, D.; Waris, A.; Haryanto, F.

    2016-03-01

    Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. The use of DSA procedures has been increased quite significantly in the Radiology departments in various cities in Indonesia. Various reports showed that both patients and medical staff received a noticeable radiation dose during the course of this procedure. A study had been carried out to measure these doses among interventionalist, nurse and radiographer. The results show that the interventionalist and the nurse, who stood quite close to the X-ray beams compared with the radiographer, received radiation higher than the others. The results also showed that the radiation dose received by medical staff were var depending upon the duration and their position against the X-ray beams. Compared tothe dose limits, however, the radiation dose received by all these three medical staff were still lower than the limits.

  12. Neutron dose equivalent meter

    DOEpatents

    Olsher, Richard H.; Hsu, Hsiao-Hua; Casson, William H.; Vasilik, Dennis G.; Kleck, Jeffrey H.; Beverding, Anthony

    1996-01-01

    A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

  13. Oxymetazoline Metered Dose Spray: Factors Affecting Delivery Volume

    PubMed Central

    Walia, Hina; Rafiq, Mahmood; Grannell, Timothy; Cartabuke, Richard S.; Tobias, Joseph D.

    2016-01-01

    OBJECTIVES: The current study compared the amount of oxymetazoline delivered by various anesthesia providers when holding the bottle in the upright and inverted position. Additionally, the amount delivered from a full bottle and a half-full bottle was also investigated. METHODS: Using an analytical balance that was calibrated to zero, we evaluated the impact the position of the bottle and the volume of oxymetazoline in the bottle had on the amount being delivered by both anesthesia staff and trainees. RESULTS: When using both filled and half-filled bottles, the amount delivered increased significantly when comparing the upright versus inverted position. With a full bottle, the amount delivered when the bottle was inverted increased almost 10-fold from 62 ± 80 to 606 ± 366 μL (p < 0.0001). Similarly, even with a half-filled bottle, the amount delivered increased in the inverted positions from 41 ± 48 to 645 ± 393 μL. Regardless of the scenario, we also noted significant variation from provider to provider. CONCLUSIONS: Our results demonstrate that several factors may affect the amount of oxymetazoline delivered for metered dose bottles. Given the potential for severe end-organ effects with excessive dosage, alternative means of delivery are needed for its perioperative use. PMID:27453703

  14. EXOMARS IRAS (DOSE) radiation measurements.

    NASA Astrophysics Data System (ADS)

    Federico, C.; Di Lellis, A. M.; Fonte, S.; Pauselli, C.; Reitz, G.; Beaujean, R.

    The characterization and the study of the radiations on their interaction with organic matter is of great interest in view of the human exploration on Mars. The Ionizing RAdiation Sensor (IRAS) selected in the frame of the ExoMars/Pasteur ESA mission is a lightweight particle spectrometer combining various techniques of radiation detection in space. It characterizes the first time the radiation environment on the Mars surface, and provide dose and dose equivalent rates as precursor information absolutely necessary to develop ways to mitigate the radiation risks for future human exploration on Mars. The Martian radiation levels are much higher than those found on Earth and they are relatively low for space. Measurements on the surface will show if they are similar or not to those seen in orbit (modified by the presence of ``albedo'' neutrons produced in the regolith and by the thin Martian atmosphere). IRAS consists of a telescope based on segmented silicon detectors of about 40\\userk\\milli\\metre\\user;k diameter and 300\\user;k\\micro\\metre\\user;k thickness, a segmented organic scintillator, and of a thermoluminescence dosimeter. The telescope will continuously monitor temporal variation of the particle count rate, the dose rate, particle and LET (Linear Energy Transfer) spectra. Tissue equivalent BC430 scintillator material will be used to measure the neutron dose. Neutrons are selected by a criteria requiring no signal in the anti-coincidence. Last, the passive thermoluminescence dosimeter, based on LiF:Mg detectors, regardless the on board operation timing, will measure the total dose accumulated during the exposure period and due to beta and gamma radiation, with a responsivity very close to that of a human tissue.

  15. Independent dose calculations for commissioning, quality assurance and dose reconstruction of PBS proton therapy

    NASA Astrophysics Data System (ADS)

    Meier, G.; Besson, R.; Nanz, A.; Safai, S.; Lomax, A. J.

    2015-04-01

    Pencil beam scanning proton therapy allows the delivery of highly conformal dose distributions by delivering several thousand pencil beams. These beams have to be individually optimised and accurately delivered requiring a significant quality assurance workload. In this work we describe a toolkit for independent dose calculations developed at Paul Scherrer Institut which allows for dose reconstructions at several points in the treatment workflow. Quality assurance based on reconstructed dose distributions was shown to be favourable to pencil beam by pencil beam comparisons for the detection of delivery uncertainties and estimation of their effects. Furthermore the dose reconstructions were shown to have a sensitivity of the order of or higher than the measurements currently employed in the clinical verification procedures. The design of the independent dose calculation tool allows for a high modifiability of the dose calculation parameters (e.g. depth dose profiles, angular spatial distributions) allowing for a safe environment outside of the clinical treatment planning system for investigating the effect of such parameters on the resulting dose distributions and thus distinguishing between different contributions to measured dose deviations. The presented system could potentially reduce the amount of patient-specific quality assurance measurements which currently constitute a bottleneck in the clinical workflow.

  16. Single-dose versus multi-dose vaccine vials for immunization programmes in developing countries.

    PubMed Central

    Drain, Paul K.; Nelson, Carib M.; Lloyd, John S.

    2003-01-01

    Excessive vaccine wastage and safety concerns have prompted the international health community to develop and supply vaccines in formats other than the standard multi-dose vial. This article presents a programmatic and economic comparison of the major differences between the multi-dose vials and single-dose formats used for immunization services in developing countries. Multi-dose vials, in general, sell at a lower per-dose price and occupy less cold-chain capacity than single-dose formats. However, higher wastage rates may offset these benefits, especially for more expensive vaccines. Single-dose formats offer several important programmatic benefits, such as increased vaccination opportunities and improved vaccine safety. One single-dose format, the prefilled auto-disable (AD) device, provides additional injection safety and convenience features because it physically combines the vaccine and AD syringe. Selecting the appropriate vaccine presentation will depend on many factors. However, multi-dose vials are likely to be most appropriate for cheaper vaccines and in settings where cold-chain storage capacity is restricted. Single-dose formats will be most appropriate for more expensive vaccines and where there are problems with unsafe injection practices. Prefilled AD injection devices will be particularly useful in expanding outreach services while eliminating the possibility of needle reuse. PMID:14758432

  17. Dose tracking and dose auditing in a comprehensive computed tomography dose-reduction program.

    PubMed

    Duong, Phuong-Anh; Little, Brent P

    2014-08-01

    Implementation of a comprehensive computed tomography (CT) radiation dose-reduction program is a complex undertaking, requiring an assessment of baseline doses, an understanding of dose-saving techniques, and an ongoing appraisal of results. We describe the role of dose tracking in planning and executing a dose-reduction program and discuss the use of the American College of Radiology CT Dose Index Registry at our institution. We review the basics of dose-related CT scan parameters, the components of the dose report, and the dose-reduction techniques, showing how an understanding of each technique is important in effective auditing of "outlier" doses identified by dose tracking. PMID:25129210

  18. Reinventing Higher Education

    ERIC Educational Resources Information Center

    Hayes, Dianne

    2012-01-01

    Higher education institutions are in the battle of a lifetime as they are coping with political and economic uncertainties, threats to federal aid, declining state support, higher tuition rates and increased competition from for-profit institutions. Amid all these challenges, these institutions are pressed to keep up with technological demands,…

  19. Higher Education in Arkansas.

    ERIC Educational Resources Information Center

    Arkansas State Dept. of Higher Education, Little Rock.

    This report presents information about higher education in Arkansas. Arkansas is 49th in the United States in the number of citizens over the age of 25 with a baccalaureate or higher degree. Arkansas faces shortages of qualified teachers and nurses in regions of the state at a time when the number of graduates in these professions is declining…

  20. Minorities in Higher Education.

    ERIC Educational Resources Information Center

    Justiz, Manuel J., Ed.; And Others

    This book presents 19 papers on efforts to increase the participation of members of minority groups in higher education. The papers are: (1) "Demographic Trends and the Challenges to American Higher Education" (Manuel Justiz); (2) "Three Realities: Minority Life in the United States--The Struggle for Economic Equity (adapted by Don M. Blandin);…

  1. Reimagining Christian Higher Education

    ERIC Educational Resources Information Center

    Hulme, E. Eileen; Groom, David E., Jr.; Heltzel, Joseph M.

    2016-01-01

    The challenges facing higher education continue to mount. The shifting of the U.S. ethnic and racial demographics, the proliferation of advanced digital technologies and data, and the move from traditional degrees to continuous learning platforms have created an unstable environment to which Christian higher education must adapt in order to remain…

  2. Quality in Higher Education.

    ERIC Educational Resources Information Center

    Ruben, Brent D., Ed.

    This volume contains 21 new and classic papers and readings on quality philosophies and concepts, first, as they have been applied in business and industry but primarily as they relate to and can be applied in higher education. The introduction is titled "The Quality Approach in Higher Education: Context and Concepts for Change" by Brent D. Ruben.…

  3. Higher Education Exchange 2006

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2006-01-01

    Contributors to this issue of the Higher Education Exchange debate the issues around knowledge production, discuss the acquisition of deliberative skills for democracy, and examine how higher education prepares, or does not prepare, students for citizenship roles. Articles include: (1) "Foreword" (Deborah Witte); (2) "Knowledge, Judgment and…

  4. UNIVERSAL HIGHER EDUCATION.

    ERIC Educational Resources Information Center

    MCGRATH, EARL J.

    THIS DOCUMENT IS A REPORT ON A GROUP INQUIRY INTO THE SUBSTANCE AND IMPLICATIONS OF UNIVERSAL HIGHER EDUCATION. ELEVEN CHAPTERS ARE PAPERS PRESENTED AT A CONFERENCE HELD UNDER THE AUSPICES OF THE INSTITUTE OF HIGHER EDUCATION, TEACHERS COLLEGE, COLUMBIA UNIVERSITY, IN PUERTO RICO, NOVEMBER 15-21, 1964, FORECASTING THE FORM AND MISSION OF AMERICAN…

  5. Reinventing Continuing Higher Education

    ERIC Educational Resources Information Center

    Walshok, Mary Lindenstein

    2012-01-01

    Re-inventing continuing higher education is about finding ways to be a more central player in a region's civic, cultural, and economic life as well as in the education of individuals for work and citizenship. Continuing higher education will require data gathering, analytical tools, convening authority, interpretive skills, new models of delivery,…

  6. Gender and Higher Education

    ERIC Educational Resources Information Center

    Bank, Barbara J., Ed.

    2011-01-01

    This comprehensive, encyclopedic review explores gender and its impact on American higher education across historical and cultural contexts. Challenging recent claims that gender inequities in U.S. higher education no longer exist, the contributors--leading experts in the field--reveal the many ways in which gender is embedded in the educational…

  7. Consumerism in Higher Education

    ERIC Educational Resources Information Center

    Green, Mark

    1973-01-01

    In considering consumerism in higher education, the student becomes the consumer,'' the university the corporation,'' and higher education the education industry.'' Other members of the education fraternity become investors, management, workers, direct consumers, and indirect consumers. This article proposes that it behooves the student to…

  8. [Deregulation and Higher Education].

    ERIC Educational Resources Information Center

    Business Officer, 1982

    1982-01-01

    The extent to which the Reagan Administration has achieved its deregulation goals in the area of higher education is addressed in three articles: "Deregulation and Higher Education: The View a Year Later" (Sheldon Elliot Steinbach); "Student Financial Aid Deregulation: Rhetoric or Reality?" (Robin E. Jenkins); and "Administration Reform of Civil…

  9. Higher Education Exchange

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2009-01-01

    This volume begins with an essay by Noelle McAfee, a contributor who is familiar to readers of Higher Education Exchange (HEX). She reiterates Mathews' argument regarding the disconnect between higher education's sense of engagement and the public's sense of engagement, and suggests a way around the epistemological conundrum of "knowledge produced…

  10. Higher Education Exchange, 2009

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2009-01-01

    This volume begins with an essay by Noelle McAfee, a contributor who is familiar to readers of Higher Education Exchange (HEX). She reiterates Kettering's president David Mathews' argument regarding the disconnect between higher education's sense of engagement and the public's sense of engagement, and suggests a way around the epistemological…

  11. Dose comparisons for mammographic systems

    SciTech Connect

    Speiser, R.C.; Zanrosso, E.M.; Jeromin, L.S.; Carlson, R.A.

    1986-09-01

    Dose estimates were made for Kodak Min-R screens combined with Kodak Min-R film and Kodak Ortho M film, both with and without a 5:1 Bucky grid; for standard xeroradiographic techniques in negative development mode; and for the new, higher sensitivity xeroradiographic process of the Xerox 175 System. The estimates were derived from exposure versus depth measurements in phantoms made of BR12 breast simulation material using thermoluminescent detectors. A molybdenum target source with molybdenum filtration, at a half-value layer of 0.37-mm Al, was used for the screen-film measurements. All xeroradiographic measurements were made with a tungsten target source with aluminum filtration at half-value layers of 1.5 to 1.56 mm Al. Mean glandular dose estimates for the Min-R screen/Ortho M film combination with Bucky grid and for the new xeroradiographic process were found to be similar. Dose reduction with the new xeroradiographic system was achieved through a more sensitive photoreceptor and more sensitive development, which also improved the unique imaging characteristics of xeroradiography.

  12. Effective dose estimation during conventional and CT urography

    NASA Astrophysics Data System (ADS)

    Alzimami, K.; Sulieman, A.; Omer, E.; Suliman, I. I.; Alsafi, K.

    2014-11-01

    Intravenous urography (IVU) and CT urography (CTU) are efficient radiological examinations for the evaluation of the urinary system disorders. However patients are exposed to a significant radiation dose. The objectives of this study are to: (i) measure and compare patient radiation dose by computed tomography urography (CTU) and conventional intravenous urography (IVU) and (ii) evaluate organ equivalent dose and cancer risks from CTU and IVU imaging procedures. A total of 141 patients were investigated. A calibrated CT machine (Siemens-Somatom Emotion duo) was used for CTU, while a Shimadzu X ray machine was used for IVU. Thermoluminescence dosimeters (TLD-GR200A) were used to measure patients' entrance surface doses (ESD). TLDs were calibrated under reproducible reference conditions. Patients radiation dose values (DLP) for CTU were 172±61 mGy cm, CTDIvol 4.75±2 mGy and effective dose 2.58±1 mSv. Patient cancer probabilities were estimated to be 1.4 per million per CTU examination. Patients ESDs values for IVU were 21.62±5 mGy, effective dose 1.79±1 mSv. CT involves a higher effective dose than IVU. In this study the radiation dose is considered low compared to previous studies. The effective dose from CTU procedures was 30% higher compared to IVU procedures. Wide dose variation between patient doses suggests that optimization is not fulfilled yet.

  13. On higher structures

    NASA Astrophysics Data System (ADS)

    Baas, Nils A.

    2016-08-01

    In this paper, we discuss various philosophical aspects of the hyperstructure concept extending networks and higher categories. By this discussion, we hope to pave the way for applications and further developments of the mathematical theory of hyperstructures.

  14. Forecasting Higher Education's Future.

    ERIC Educational Resources Information Center

    Boyken, Don; Buck, Tina S.; Kollie, Ellen; Przyborowski, Danielle; Rondinelli, Joseph A.; Hunter, Jeff; Hanna, Jeff

    2003-01-01

    Offers predictions on trends in higher education to accommodate changing needs, lower budgets, and increased enrollment. They involve campus construction, security, administration, technology, interior design, athletics, and transportation. (EV)

  15. Marketing Higher Education

    ERIC Educational Resources Information Center

    O'Brian, Edward J.

    1973-01-01

    Describes the 4 basic areas in which institutional marketing can be put to use in higher educational institutions: educational services offered, pricing (tuition), promotion to prospective students, and distribution (extension courses and courses that go to the student). (PG)

  16. Sampling and recording dose rate meter

    SciTech Connect

    Kronenberg, S.

    1984-04-06

    A wide range radiation dose rate for civil defense use, including a Geiger-Mueller tube used in a continuous counting mode and for measuring dose rates from the natural background to about 30. rads/hr., with an ion chamber arranged to measure higher dose rates up to 10,000 rads/hr. The instrument has a sample and record capability in which the selected radiation detector will have its output connected to a selected storage capacitor for a precise interval of time determined by a timing circuit and the storage capacitor will accumulate and hold a voltage proportional to the dose rate, which can be read by means of an electrometer at a later time. The instrument has a self contained hand cranked power supply and all components are selected for long shelf life.

  17. Acetaminophen dosing for children

    MedlinePlus

    Taking acetaminophen (Tylenol) can help children with colds and fever feel better. As with all drugs, it is important to give children the correct dose. Acetaminophen is safe when taken as directed. But taking ...

  18. Calculating drug doses.

    PubMed

    2016-09-01

    Numeracy and calculation are key skills for nurses. As nurses are directly accountable for ensuring medicines are prescribed, dispensed and administered safely, they must be able to understand and calculate drug doses. PMID:27615351

  19. Effects of dose rate on microsturctural evolution and swelling in austenitic steels under irradiation

    NASA Astrophysics Data System (ADS)

    Okita, T.; Kamada, T.; Sekimura, N.

    2000-12-01

    Effects of dose rate on microstructural evolution in a simple model austenitic ternary alloy are examined. Annealed specimens are irradiated with fast neutrons at several positions in the core and above core in FFTF/MOTA between 390°C and 435°C in a wide range of doses and dose rates. In Fe-15Cr-16Ni, swelling seems to increase linearly with dose without incubation dose. Cavities are observed even in the specimens irradiated to 0.07 dpa at 1.9×10-9 dpa/s. Both cavity nucleation and growth are enhanced by low dose rates. These are mainly caused by accelerated formation of dislocation loops at lower dose rates. Low dose rates enhance swelling by shortening incubation dose for the onset of steady-state swelling. In the specimens irradiated at higher dose rates to higher doses, high density of dislocation increases average cavity diameter, however decreases cavity density.

  20. Nuclear medicine annual external occupational dose distribution: Rio de Janeiro, Brazil, year 2005.

    PubMed

    Mauricio, Claudia L P; Lima, Ana L S; da Silva, Herica L R; Souza-Santos, Denison; Silva, Claudio R

    2011-03-01

    Brazil has about 300 nuclear medicine services (NMS), 44 of them located in the state of Rio de Janeiro (RJ). Most nuclear medicine staff are routinely monitored for external dose. This paper makes a statistical analysis of all the RJ NMS annual external occupational doses in year 2005. Around 100 professionals of RJ NMS received annual doses >4.0 mSv, considering only external doses, but no one receives doses higher than the mean annual dose limit of 20 mSv. Extremities dosemeters are used by about 10 % of the staff. In some cases, these doses are more than 10 times higher than the dose in thorax. The maximum ratio of extremity dose/thorax dose, in 2005, was 72. This study shows the importance to improve radiation protection procedures in nuclear medicine, mainly because the number of occupational individuals in nuclear medicine and their external doses are increasing. PMID:21051433

  1. Pain and Mean Absorbed Dose to the Pubic Bone After Radiotherapy Among Gynecological Cancer Survivors

    SciTech Connect

    Waldenstroem, Ann-Charlotte; Olsson, Caroline; Wilderaeng, Ulrica; Dunberger, Gail; Lind, Helena; Al-Abany, Massoud; Palm, Asa; Avall-Lundqvist, Elisabeth; Johansson, Karl-Axel; Steineck, Gunnar

    2011-07-15

    Purpose: To analyze the relationship between mean absorbed dose to the pubic bone after pelvic radiotherapy for gynecological cancer and occurrence of pubic bone pain among long-term survivors. Methods and Materials: In an unselected, population-based study, we identified 823 long-term gynecological cancer survivors treated with pelvic radiotherapy during 1991-2003. For comparison, we used a non-radiation-treated control population of 478 matched women from the Swedish Population Register. Pain, intensity of pain, and functional impairment due to pain in the pubic bone were assessed with a study-specific postal questionnaire. Results: We analyzed data from 650 survivors (participation rate 79%) with median follow-up of 6.3 years (range, 2.3-15.0 years) along with 344 control women (participation rate, 72 %). Ten percent of the survivors were treated with radiotherapy; ninety percent with surgery plus radiotherapy. Brachytherapy was added in 81%. Complete treatment records were recovered for 538/650 survivors, with dose distribution data including dose-volume histograms over the pubic bone. Pubic bone pain was reported by 73 survivors (11%); 59/517 (11%) had been exposed to mean absorbed external beam doses <52.5 Gy to the pubic bone and 5/12 (42%) to mean absorbed external beam doses {>=}52.5 Gy. Thirty-three survivors reported pain affecting sleep, a 13-fold increased prevalence compared with control women. Forty-nine survivors reported functional impairment measured as pain walking indoors, a 10-fold increased prevalence. Conclusions: Mean absorbed external beam dose above 52.5 Gy to the pubic bone increases the occurrence of pain in the pubic bone and may affect daily life of long-term survivors treated with radiotherapy for gynecological cancer.

  2. Higher dimensional Hadamard matrices

    NASA Technical Reports Server (NTRS)

    Schlichta, P. J.

    1979-01-01

    The paper defines higher dimensional Hadamard matrices and enumerates on some of the simplest three-, four-, and five-dimensional cases and procedures for generating them. Special emphasis is given to proper matrices that have a dimensional hierarchy of orthogonalities. It is determined that this property lends itself primarily to the application of higher dimensional Hadamard matrices to error-correcting codes. A list of derived statements for n-dimensional Hadamard matrices are given, as well as a definition of Hadamard matrix families, such as minimal, Petrie polygon, antipodal (n-2)-dimensional sections, and double proximity shells.

  3. Higher Spin Holography

    NASA Astrophysics Data System (ADS)

    Chang, Chi-Ming

    This dissertation splits into two distinct halves. The first half is devoted to the study of the holography of higher spin gauge theory in AdS 3. We present a conjecture that the holographic dual of W N minimal model in a 't Hooft-like large N limit is an unusual "semi-local" higher spin gauge theory on AdS3 x 1. At each point on the S1 lives a copy of three-dimensional Vasiliev theory, that contains an infinite tower of higher spin gauge fields coupled to a single massive complex scalar propagating in AdS3. The Vasiliev theories at different points on the S1 are correlated only through the AdS3 boundary conditions on the massive scalars. All but one single tower of higher spin symmetries are broken by the boundary conditions. This conjecture is checked by comparing tree-level two- and three-point functions, and also one-loop partition functions on both side of the duality. The second half focuses on the holography of higher spin gauge theory in AdS 4. We demonstrate that a supersymmetric and parity violating version of Vasiliev's higher spin gauge theory in AdS4 admits boundary conditions that preserve N = 0,1,2,3,4 or 6 supersymmetries. In particular, we argue that the Vasiliev theory with U( M) Chan-Paton and N = 6 boundary condition is holographically dual to the 2+1 dimensional U(N) k x U(M) -k ABJ theory in the limit of large N, k and finite M. In this system all bulk higher spin fields transform in the adjoint of the U(M) gauge group, whose bulk t'Hooft coupling is M/N. Our picture suggests that the supersymmetric Vasiliev theory can be obtained as a limit of type IIA string theory in AdS4 x CP3, and that the non-Abelian Vasiliev theory at strong bulk 't Hooft coupling smoothly turn into a string field theory. The fundamental string is a singlet bound state of Vasiliev's higher spin particles held together by U(M) gauge interactions.

  4. Higher spin cosmology

    NASA Astrophysics Data System (ADS)

    Krishnan, Chethan; Raju, Avinash; Roy, Shubho; Thakur, Somyadip

    2014-02-01

    We construct cosmological solutions of higher spin gravity in 2+1 dimensional de Sitter space. We show that a consistent thermodynamics can be obtained for their horizons by demanding appropriate holonomy conditions. This is equivalent to demanding the integrability of the Euclidean boundary conformal field theory partition function, and it reduces to Gibbons-Hawking thermodynamics in the spin-2 case. By using the prescription of Maldacena, we relate the thermodynamics of these solutions to those of higher spin black holes in AdS3.

  5. Evaluation of image and dose according to I-dose technique when performing a CT scan

    NASA Astrophysics Data System (ADS)

    Ryu, S. W.; Lee, H. K.; Cho, J. H.

    2015-06-01

    In this study, we applied the iterative reconstruction technique to improve image quality (I-dose) and evaluated its usability by analyzing the quality of the resulting image and evaluating the dose. To perform the scans, we fixed the uniform module (CTP 486's section) 4 on the table of the computed tomography (CT) device with the American association of physicists in medicine (AAPM) phantom and located it in the center where the X-rays could be generated by using a razor beam. Then, we set up the conditions of 120 kilovoltage peak (kVp), 150 milliampere second (mAs), collimation 4 × 0.625 mm, and a standard YA (Y-Sharp) filter. Next, we formed two groups: Group A in which I-dose was not applied and Group B in which I-dose was applied. According to the rod in the middle, after fixing the location of (A) at 12 o'clock, (B) at 3 o'clock, (C) at 6 o'clock, and (D) at 9 o'clock to evaluate the image quality, the CT number was measured and the noise level was analyzed. Using the AAPM phantom with doses of 50, 100, 200, 250, and 300 mAs by 80, 100, and 120 kVp, a dose analysis was performed. After scanning, the CT numbers and noise level were measured 20 times as a function of the I-dose levels (1-7). After applying I-dose at 6, 9, 12, and 3 o'clock, when a higher I-dose was applied, a lower noise level was measured. As a result, it was found that when applying I-dose to the AAPM phantom, the higher the level of I-dose, the lower the level of noise. When applying I-dose, the dose can be reduced by 60%. When I-dose is applied when taking CT scans in a clinical study, it is possible to lower the dose and lower the noise level.

  6. Interdisciplinarity in Higher Education.

    ERIC Educational Resources Information Center

    Hanisch, Thor Einar; Vollmann, Wolfgang, Ed.

    The advantages of an interdisciplinary approach to college instruction and research are examined, based in part on a 1983 symposium of the European Centre for Higher Education. Six case studies are also presented. It is noted that interdisciplinarity opens up possibilities of exchange between individual disciplines and encourages the development…

  7. Higher Education's Strange Paradox.

    ERIC Educational Resources Information Center

    Howe, Harold, II

    The university which has had the temerity to change the world has not had the nerve to change itself to live in that world. The result is that the university's grading system, curriculum, teaching methods, and philosophies are in conflict with the world beyond the campus gates, and higher education does not meet the intellectual and social needs…

  8. Entrepreneurship and Higher Education

    ERIC Educational Resources Information Center

    Potter, Jonathan, Ed.

    2008-01-01

    Stimulating innovative and growth-oriented entrepreneurship is a key economic and societal challenge to which universities and colleges have much to contribute. This book examines the role that higher education institutions are currently playing through teaching entrepreneurship and transferring knowledge and innovation to enterprises and…

  9. California's Future: Higher Education

    ERIC Educational Resources Information Center

    Johnson, Hans

    2015-01-01

    California's higher education system is not keeping up with the changing economy. Projections suggest that the state's economy will continue to need more highly educated workers. In 2025, if current trends persist, 41 percent of jobs will require at least a bachelor's degree and 36 percent will require some college education short of a bachelor's…

  10. Corporatizing Higher Education

    ERIC Educational Resources Information Center

    Lerner, Gerda

    2008-01-01

    The process of changing U.S. higher education institutions along a corporate model has been going on for several decades. It consists of changes, some open, some obscured, on various fronts: the erosion of tenure by attrition; the simultaneous increase in the use of contingent faculty; the rise in tuition; the dramatic decrease in federal and…

  11. Marketing in Higher Education.

    ERIC Educational Resources Information Center

    Hockenberger, Susan J.

    Educational institutions must seek new approaches to institutional planning because of such factors as shrinking traditional college age populations, eroding grants, governmental and judicial incursion, the tightening economic belt, and concern over the relevance of education to modern day needs. The concept of marketing higher education is…

  12. Liberty and Higher Education.

    ERIC Educational Resources Information Center

    Thompson, Dennis F.

    1989-01-01

    John Stuart Mill's principle of liberty is discussed with the view that it needs to be revised to guide moral judgments in higher education. Three key elements need to be modified: the action that is constrained; the constraint on the action; and the agent whose action is constrained. (MLW)

  13. Higher Education Staff.

    ERIC Educational Resources Information Center

    Clery, Sue; Lee, John

    1999-01-01

    This report reviews changes in higher education staff by occupation between 1993 and 1997. Specific attention is paid to staffing patterns in states with right to work laws compared to those without it. When a state enacts a right to work law, it can be assumed it is not supportive of public unions. This analysis is based on data from the National…

  14. Curriculum in Higher Education.

    ERIC Educational Resources Information Center

    Rothman, A. I., Ed.

    1981-01-01

    Four articles on higher education curriculum are presented. In "The Articulate Curriculum" an approach to curriculum description is presented that is designed to have minimal ambiguity concerning the intention, content, and processes of the curriculum and that will lead to questioning several discrete factors in the curriculum planning process. It…

  15. Networks for Higher Education.

    ERIC Educational Resources Information Center

    Interuniversity Communications Council (EDUCOM), Princeton, NJ.

    EDUCOM, the Inter University Communications Council, Inc., planned its 1972 spring conference as a forum for presentations, discussions, and informal meetings to review the present state and the future possibilities of computer networks for higher education. Speeches presented were specifically related to: (1) the current status and future plans…

  16. Evaluation in Higher Education

    ERIC Educational Resources Information Center

    Bognar, Branko; Bungic, Maja

    2014-01-01

    One of the means of transforming classroom experience is by conducting action research with students. This paper reports about the action research with university students. It has been carried out within a semester of the course "Methods of Upbringing". Its goal has been to improve evaluation of higher education teaching. Different forms…

  17. Marketing in Higher Education.

    ERIC Educational Resources Information Center

    Dalili, Farid

    The use of marketing activities by educational institutions and the transfer of marketing activities from business to higher education are considered. Market analysis helps colleges and universities determine what programs, scheduling, or services are strong and to which student market the institution should appeal. It is suggested that the…

  18. Understanding Higher Education Costs

    ERIC Educational Resources Information Center

    Middaugh, Michael F.

    2005-01-01

    Public discussion of higher education costs frequently confuses price with expenditure. This article examines factors associated with increases in the sticker price of a college education and the expenditures incurred by institutions in delivering that education. The discussion suggests that while growth in college tuition is real, access to…

  19. Higher Education Exchange, 2013

    ERIC Educational Resources Information Center

    Brown, David W., Ed.; Witte, Deborah, Ed.

    2013-01-01

    The Kettering Foundation's research has been focused on putting the public back into the public's business for more than thirty years. Some questions that have recently been useful to Kettering researchers as the foundation focuses on its work with institutional actors--especially higher education and its relationship with the public--have…

  20. Women in Higher Education.

    ERIC Educational Resources Information Center

    Pifer, Alan

    Women have traditionally been discriminated against in higher education in both the attainment of degrees and in employment after earning degrees. It has been felt that women are not as capable, reliable, or effective as men in administrative and classroom situations. Statistics show that even at the present time women are underemployed and…

  1. Benchmarking for Higher Education.

    ERIC Educational Resources Information Center

    Jackson, Norman, Ed.; Lund, Helen, Ed.

    The chapters in this collection explore the concept of benchmarking as it is being used and developed in higher education (HE). Case studies and reviews show how universities in the United Kingdom are using benchmarking to aid in self-regulation and self-improvement. The chapters are: (1) "Introduction to Benchmarking" (Norman Jackson and Helen…

  2. Online Higher Education Commodity

    ERIC Educational Resources Information Center

    Chau, Paule

    2010-01-01

    This article analyzes the current trend towards online education. It examines some of the reasons for the trend and the ramifications it may have on students, faculty and institutions of higher learning. The success and profitability of online programs and institutions such as the University of Phoenix has helped to make the move towards online…

  3. Women in Higher Education.

    ERIC Educational Resources Information Center

    O'Donnell, Sheryl, Ed.; Shaver, Barbara, Ed.

    1981-01-01

    Articles on women's studies and females in higher education are presented in this publication. A University of North Dakota project that sought to promote the integration of new research and scholarship results into the curriculum is described in "Women's Equity Committee Offers a Model Project," (Leola Furman, Robert Young). Historical…

  4. Creativity in Higher Education

    ERIC Educational Resources Information Center

    Gaspar, Drazena; Mabic, Mirela

    2015-01-01

    The paper presents results of research related to perception of creativity in higher education made by the authors at the University of Mostar from Bosnia and Herzegovina. This research was based on a survey conducted among teachers and students at the University. The authors developed two types of questionnaires, one for teachers and the other…

  5. Black at Higher Education

    ERIC Educational Resources Information Center

    Kadi-Hanifi, Karima

    2013-01-01

    This is an exploratory paper, drawing on the author's experiences as well as those of three other black lecturers in Higher Education (HE). Three interviews were carried out, asking the same five questions around themes of concern to the author. These are about the learning and teaching approaches used by these lecturers; their experiences of…

  6. Higher Education Exchange 1995.

    ERIC Educational Resources Information Center

    Brown, David W., Ed.

    Nine articles discuss the relationship between the higher education community and the public. The articles are: (1) "On a Certain Blindness in Teaching" by Michael S. Roth, who stresses the necessity of political citizenship education for a healthy democracy; (2) "Monocultural Perspectives and Campus Diversity" by Jane Fried, who explores the…

  7. Unraveling Higher Education's Costs.

    ERIC Educational Resources Information Center

    Gordon, Gus; Charles, Maria

    1998-01-01

    The activity-based costing (ABC) method of analyzing institutional costs in higher education involves four procedures: determining the various discrete activities of the organization; calculating the cost of each; determining the cost drivers; tracing cost to the cost objective or consumer of each activity. Few American institutions have used the…

  8. NEXUS: Digitizing Higher Education.

    ERIC Educational Resources Information Center

    Kirk, Camille

    2000-01-01

    Discussion of digital technology in the context of higher education planning considers how these technologies change teaching; the digital divide; the costs of information technology; hard wiring the campus; material consequences of information technology; digitally enabled crimes and misdemeanors; and libraries and scholarly publishing. Concludes…

  9. Valuing Higher Education

    ERIC Educational Resources Information Center

    Pillay, Gerald J.

    2009-01-01

    The question of the value of higher education is today set in the context of an unprecedented banking and financial crisis. In this context of fundamental change and financial realignment, it is important that we as members of the university remake our case for why the university deserves to be considered alongside all those other worthy causes…

  10. Developing Higher Level Thinking

    ERIC Educational Resources Information Center

    Limbach, Barbara; Waugh, Wendy

    2010-01-01

    This paper identifies an interdisciplinary, five-step process, built upon existing theory and best practices in cognitive development, effective learning environments, and outcomes-based assessment. The "Process for the Development of Higher Level Thinking Skills" provides teachers with an easy to implement method of moving toward a more…

  11. Free Higher Education

    ERIC Educational Resources Information Center

    Reed, Jr., Adolph; Szymanski, Sharon

    2004-01-01

    The crisis of affordability in higher education is intensifying. Illustrations of its resonance abound: from the frequent news articles describing and amplifying the crisis and its sources to legislators' and candidates' proposed responses. Republicans' responses tend to be mainly punitive toward institutions; Democrats' proposals are more…

  12. Shell Higher Olefins Process.

    ERIC Educational Resources Information Center

    Lutz, E. F.

    1986-01-01

    Shows how olefin isomerization and the exotic olefin metathesis reaction can be harnessed in industrial processes. Indicates that the Shell Higher Olefins Process makes use of organometallic catalysts to manufacture alpha-olefins and internal carbon-11 through carbon-14 alkenes in a flexible fashion that can be adjusted to market needs. (JN)

  13. Comparative Higher Education.

    ERIC Educational Resources Information Center

    Altbach, Philip G.

    The comparative higher education course offered at the State University of New York at Buffalo is briefly described, and a course schedule is presented, including required and recommended readings for each topic. The course is intended to provide a broad cross-cultural perspective and considers the growth and development of universities in Europe,…

  14. Dose reconstruction for intensity-modulated radiation therapy using a non-iterative method and portal dose image

    NASA Astrophysics Data System (ADS)

    Yeo, Inhwan Jason; Jung, Jae Won; Chew, Meng; Kim, Jong Oh; Wang, Brian; Di Biase, Steven; Zhu, Yunping; Lee, Dohyung

    2009-09-01

    A straightforward and accurate method was developed to verify the delivery of intensity-modulated radiation therapy (IMRT) and to reconstruct the dose in a patient. The method is based on a computational algorithm that linearly describes the physical relationship between beamlets and dose-scoring voxels in a patient and the dose image from an electronic portal imaging device (EPID). The relationship is expressed in the form of dose response functions (responses) that are quantified using Monte Carlo (MC) particle transport techniques. From the dose information measured by the EPID the received patient dose is reconstructed by inversely solving the algorithm. The unique and novel non-iterative feature of this algorithm sets it apart from many existing dose reconstruction methods in the literature. This study presents the algorithm in detail and validates it experimentally for open and IMRT fields. Responses were first calculated for each beamlet of the selected fields by MC simulation. In-phantom and exit film dosimetry were performed on a flat phantom. Using the calculated responses and the algorithm, the exit film dose was used to inversely reconstruct the in-phantom dose, which was then compared with the measured in-phantom dose. The dose comparison in the phantom for all irradiated fields showed a pass rate of higher than 90% dose points given the criteria of dose difference of 3% and distance to agreement of 3 mm.

  15. Factors modifying valproate plasma level/dose ratio: age, sex, dose and plasma level.

    PubMed

    Sánchez, A; Durán, J A; Abadín, J A

    1989-09-01

    Valproate plasma level/dose (L/D) ratios obtained from 155 outpatients under long-term monotherapeutic regimen have been studied. Analytical data were obtained by enzymatic immunoassay (EMIT) from paired samples taken before the morning drug dosage. L/D ratios were increased with age and plasma level and decreased with dose. There were no sex differences in L/D in the different age, dose and concentration groups. L/D ratios were higher than those found by other researchers in our country. PMID:2511386

  16. Radiotherapy alone in breast cancer. I. Analysis of tumor parameters, tumor dose and local control: the experience of the Gustave-Roussy Institute and the Princess Margaret Hospital

    SciTech Connect

    Arriagada, R.; Mouriesse, H.; Sarrazin, D.; Clark, R.M.; Deboer, G.

    1985-10-01

    This retrospective study involved 463 breast cancer patients treated by radiotherapy alone at the Princess Margaret Hospital and at the Institut Gustave-Roussy. These patients either had operable tumors, but were unfit for general anesthesia, or had inoperable tumors due to local contraindications to surgery. Results were analyzed according to tumor response, local recurrence rate, tumor size, tumor fixation, nodal fixation and tumor dose. Conventional statistical analysis of local control showed two significant factors: tumor dose and tumor size. Multivariate analysis permitted to define an ''individual risk'' (IR) of local recurrence according to three independent factors: tumor size, tumor fixation, and nodal fixation. It was shown that the IR was a good prognostic factor for local control. Increase in tumor dose gave a similar effect in the local recurrence relative risk for all the IR groups. According to the slope of the dose-effect curve, it was deduced that a dose increase of 15 Gy can decrease the relative risk of local recurrence 2-fold. In fact, it was shown that tumor dose was the most significant independent factor on local control, able to produce up to a 10-fold increase compared to 2-fold decrease for tumor size. If the IR of local recurrence is known, a theoretical predictive value on local control, taking into account the tumor dose, can be determined according to the present data.

  17. Utirik Atoll Dose Assessment

    SciTech Connect

    Robison, W.L.; Conrado, C.L.; Bogen, K.T

    1999-10-06

    On March 1, 1954, radioactive fallout from the nuclear test at Bikini Atoll code-named BRAVO was deposited on Utirik Atoll which lies about 187 km (300 miles) east of Bikini Atoll. The residents of Utirik were evacuated three days after the fallout started and returned to their atoll in May 1954. In this report we provide a final dose assessment for current conditions at the atoll based on extensive data generated from samples collected in 1993 and 1994. The estimated population average maximum annual effective dose using a diet including imported foods is 0.037 mSv y{sup -1} (3.7 mrem y{sup -1}). The 95% confidence limits are within a factor of three of their population average value. The population average integrated effective dose over 30-, 50-, and 70-y is 0.84 mSv (84, mrem), 1.2 mSv (120 mrem), and 1.4 mSv (140 mrem), respectively. The 95% confidence limits on the population-average value post 1998, i.e., the 30-, 50-, and 70-y integral doses, are within a factor of two of the mean value and are independent of time, t, for t > 5 y. Cesium-137 ({sup 137}Cs) is the radionuclide that contributes most of this dose, mostly through the terrestrial food chain and secondarily from external gamma exposure. The dose from weapons-related radionuclides is very low and of no consequence to the health of the population. The annual background doses in the U. S. and Europe are 3.0 mSv (300 mrem), and 2.4 mSv (240 mrem), respectively. The annual background dose in the Marshall Islands is estimated to be 1.4 mSv (140 mrem). The total estimated combined Marshall Islands background dose plus the weapons-related dose is about 1.5 mSv y{sup -1} (150 mrem y{sup -1}) which can be directly compared to the annual background effective dose of 3.0 mSv y{sup -1} (300 mrem y{sup -1}) for the U. S. and 2.4 mSv y{sup -1} (240 mrem y{sup -1}) for Europe. Moreover, the doses listed in this report are based only on the radiological decay of {sup 137}Cs (30.1 y half-life) and other

  18. Generalized higher gauge theory

    NASA Astrophysics Data System (ADS)

    Ritter, Patricia; Sämann, Christian; Schmidt, Lennart

    2016-04-01

    We study a generalization of higher gauge theory which makes use of generalized geometry and seems to be closely related to double field theory. The local kinematical data of this theory is captured by morphisms of graded manifolds between the canonical exact Courant Lie 2-algebroid T M ⊕ T ∗ M over some manifold M and a semistrict gauge Lie 2-algebra. We discuss generalized curvatures and infinitesimal gauge transformations. Finite gauge transformation as well as global kinematical data are then obtained from principal 2-bundles over 2-spaces. As dynamical principle, we consider first the canonical Chern-Simons action for such a gauge theory. We then show that a previously proposed 3-Lie algebra model for the six-dimensional (2,0) theory is very naturally interpreted as a generalized higher gauge theory.

  19. Impact of Surface Curvature on Dose Delivery in Intraoperative High-Dose-Rate Brachytherapy

    SciTech Connect

    Oh, Moonseong Wang Zhou; Malhotra, Harish K.; Jaggernauth, Wainwright; Podgorsak, Matthew B.

    2009-04-01

    In intraoperative high-dose-rate (IOHDR) brachytherapy, a 2-dimensional (2D) geometry is typically used for treatment planning. The assumption of planar geometry may cause serious errors in dose delivery for target surfaces that are, in reality, curved. A study to evaluate the magnitude of these errors in clinical practice was undertaken. Cylindrical phantoms with 6 radii (range: 1.35-12.5 cm) were used to simulate curved treatment geometries. Treatment plans were developed for various planar geometries and were delivered to the cylindrical phantoms using catheters inserted into Freiburg applicators of varying dimension. Dose distributions were measured using radiographic film. In comparison to the treatment plan (for a planar geometry), the doses delivered to prescription points were higher on the concave side of the geometry, up to 15% for the phantom with the smallest radius. On the convex side of the applicator, delivered doses were up to 10% lower for small treated areas ({<=} 5 catheters) but, interestingly, the dose error was negligible for large treated areas (>5 catheters). Our measurements have shown inaccuracy in dose delivery when the original planar treatment plan is delivered with a curved applicator. Dose delivery errors arising from the use of planar treatment plans with curved applicators may be significant.

  20. Optimized Dose Distribution of Gammamed Plus Vaginal Cylinders

    SciTech Connect

    Supe, Sanjay S. Bijina, T.K.; Varatharaj, C.; Shwetha, B.; Arunkumar, T.; Sathiyan, S.; Ganesh, K.M.; Ravikumar, M.

    2009-04-01

    points were higher for the apex model compared with the non-apex model. Mean doses to the optimization points for both the cylinder models and all the cylinder diameters were 6 Gy, matching with the prescription dose of 6 Gy. Iterative optimization routine resulted in the highest dose to apex point and dome points. The mean dose for optimization point was 6.01 Gy for iterative optimization and was much higher than 5.74 Gy for geometric and equal times routines. Step size of 1 cm gave the highest dose to the apex point. This step size was superior in terms of mean dose to optimization points. Selection of dose optimization points for the derivation of optimized dose distributions for vaginal cylinders affects the dose distributions.

  1. Dose Reduction Techniques

    SciTech Connect

    WAGGONER, L.O.

    2000-05-16

    As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the smart things that protect the worker but do not hinder him while the task is being accomplished. In addition, we should not demand that large amounts of money be spent for equipment that has marginal value in order to save a few millirem. We have broken the handout into sections that should simplify the presentation. Time, distance, shielding, and source reduction are methods used to reduce dose and are covered in Part I on work execution. We then look at operational considerations, radiological design parameters, and discuss the characteristics of personnel who deal with ALARA. This handout should give you an overview of what it takes to have an effective dose reduction program.

  2. Ingestion of Nevada Test Site Fallout: Internal dose estimates

    SciTech Connect

    Whicker, F.W.; Kirchner, T.B.; Anspaugh, L.R.

    1996-10-01

    This paper summarizes individual and collective dose estimates for the internal organs of hypothetical yet representative residents of selected communities that received measurable fallout from nuclear detonations at the Nevada Test Site. The doses, which resulted from ingestion of local and regional food products contaminated with over 20 radionuclides, were estimated with use of the PATHWAY food-chain-transport model to provide estimates of central tendency and uncertainty. The thyroid gland received much higher doses than other internal organs and tissues. In a avery few cases, infants might have received thyroid doses in excess of 1 Gy, depending on location, diet, and timing of fallout. {sup 131}I was the primary thyroid dose contributor, and fresh milk was the main exposure pathway. With the exception of the thyroid, organ doses from the ingestion pathway were much smaller (<3%) than those from external gamma exposure to deposited fallout. Doses to residents living closest to the Nevada Test Site were contributed mainly by a few fallout events; doses to more distantly located people were generally smaller, but a greater number of events provided measurable contributions. The effectiveness of different fallout events in producing internal organ doses through ingestion varied dramatically with seasonal timing of the test, with maximum dose per unit fallout occurring for early summer depositions when milk cows were on pasture and fresh, local vegetables were used. Within specific communities, internal doses differed by age, sex, and lifestyle. Collective internal dose estimates for specific geographic areas are provided.

  3. OCCUPATIONAL DOSE ASSESSMENT IN INTERVENTIONAL CARDIOLOGY IN SERBIA.

    PubMed

    Kaljevic, J; Ciraj-Bjelac, O; Stankovic, J; Arandjic, D; Bozovic, P; Antic, V

    2016-09-01

    The objective of this work is to assess the occupational dose in interventional cardiology in a large hospital in Belgrade, Serbia. A double-dosimetry method was applied for the estimation of whole-body dose, using thermoluminescent dosemeters, calibrated in terms of the personal dose equivalent Hp(10). Besides the double-dosimetry method, eye dose was also estimated by means of measuring ambient dose equivalent, H*(10), and doses per procedure were reported. Doses were assessed for 13 physicians, 6 nurses and 10 radiographers, for 2 consequent years. The maximum annual effective dose assessed was 4.3, 2.1 and 1.3 mSv for physicians, nurses and radiographers, respectively. The maximum doses recorded by the dosemeter worn at the collar level (over the apron) were 16.8, 11.9 and 4.5 mSv, respectively. This value was used for the eye lens dose assessment. Estimated doses are in accordance with or higher than annual dose limits for the occupational exposure. PMID:26464526

  4. Ingestion of Nevada Test Site fallout: internal dose estimates.

    PubMed

    Whicker, F W; Kirchner, T B; Anspaugh, L R; Ng, Y C

    1996-10-01

    This paper summarizes individual and collective dose estimates for the internal organs of hypothetical yet representative residents of selected communities that received measurable fallout from nuclear detonations at the Nevada Test Site. The doses, which resulted from ingestion of local and regional food products contaminated with over 20 radionuclides, were estimated with use of the PATHWAY food-chain-transport model to provide estimates of central tendency and uncertainty. The thyroid gland received much higher doses than other internal organs and tissues. In a very few cases, infants might have received thyroid doses in excess of 1 Gy, depending on location, diet, and timing of fallout. 131I was the primary thyroid dose contributor, and fresh milk was the main exposure pathway. With the exception of the thyroid, organ doses from the ingestion pathway were much smaller (< 3%) than those from external gamma exposure to deposited fallout. Doses to residents living closest to the Nevada Test Site were contributed mainly by a few fallout events; doses to more distantly located people were generally smaller, but a greater number of events provided measurable contributions. The effectiveness of different fallout events in producing internal organ doses through ingestion varied dramatically with seasonal timing of the test, with maximum dose per unit fallout occurring for early summer depositions when milk cows were on pasture and fresh, local vegetables were used. Within specific communities, internal doses differed by age, sex, and lifestyle. Collective internal dose estimates for specific geographic areas are provided. PMID:8830749

  5. Dose Calculation Spreadsheet

    1997-06-10

    VENTSAR XL is an EXCEL Spreadsheet that can be used to calculate downwind doses as a result of a hypothetical atmospheric release. Both building effects and plume rise may be considered. VENTSAR XL will run using any version of Microsoft EXCEL version 4.0 or later. Macros (the programming language of EXCEL) was used to automate the calculations. The user enters a minimal amount of input and the code calculates the resulting concentrations and doses atmore » various downwind distances as specified by the user.« less

  6. Pharmacokinetics and Drug Dosing in Obese Children

    PubMed Central

    Kendrick, Jennifer G.; Carr, Roxane R.; Ensom, Mary H.H.

    2010-01-01

    OBJECTIVES To review pharmacokinetics in obese children and to provide medication dosing recommendations. METHODS EMBASE, MEDLINE, and International Pharmaceutical Abstracts databases were searched using the following terms: obesity, morbid obesity, overweight, pharmacokinetics, drug, dose, kidney function test, creatinine, pediatric, and child. RESULTS We identified 10 studies in which the authors examined drug dosing or pharmacokinetics for obese children. No information was found for drug absorption or metabolism. Obese children have a higher percent fat mass and a lower percent lean mass compared with normal-weight children. Therefore, in obese children, the volume of distribution of lipophilic drugs is most likely higher, and that of hydrophilic drugs is most likely lower, than in normal-weight children. Serum creatinine concentrations are higher in obese than normal-weight children. Total body weight is an appropriate size descriptor for calculating doses of antineoplastics, cefazolin, and succinylcholine in obese children. Initial tobramycin doses may be determined using an adjusted body weight, although using total body weight in the context of monitoring serum tobramycin concentrations would also be an appropriate strategy. We found no information for any of the opioids; antibiotics such as penicillins, carbapenems, vancomycin, and linezolid; antifungals; cardiac drugs such as digoxin and amiodarone; corticosteroids; benzodiazepines; and anticonvulsants. In particular, we found no information about medications that are widely distributed to adipose tissue or that can accumulate there. CONCLUSIONS The available data are limited because of the small numbers of participating children, study design, or both. The number and type of drugs that have been studied limit our understanding of the pharmacokinetics in obese children. In the absence of dosing information for obese children, it is important to consider the nature and severity of a child's illness

  7. Low-Dose Radioactive Iodine Destroys Thyroid Tissue Left after Surgery

    Cancer.gov

    A low dose of radioactive iodine given after surgery for thyroid cancer destroyed (ablated) residual thyroid tissue as effectively as a higher dose, with fewer side effects and less exposure to radiation, according to two randomized controlled trials.

  8. In vivo percutaneous absorption of acetochlor in the rhesus monkey: dose-response and exposure risk assessment.

    PubMed

    Wester, R C; Melendres, J L; Maibach, H I

    1996-10-01

    Percutaneous absorption of three topical dose levels of [14C]acetochlor in the rhesus monkey were determined for exposure risk assessment. The topical doses were 30.7, 0.43 and 0.03 mg acetochlor in 40 microliters commercial formulation and aqueous dilutions thereof, spread over 10 cm3 skin surface area (lower abdominal). The dosing area was not covered. The skin application time was 24 hr. The dosed skin surface area was washed with 50% soap (Ivory Liquid) and water at the end of the 24-hr dosing period. An intravenous dose of 0.43 mg was also administered to determine the excretory kinetics of acetochlor in the rhesus monkey. The same four monkeys were used for all dose administrations. Bioavailability was determined by radioactivity disposition in blood, urine and faeces. Percutaneous absorption was 23.1 +/- 8.7, 17.3 +/- 5.9 and 4.9 +/- 1.4% for 0.03, 0.43 and 30.7 mg doses, respectively. Assuming a constant state of absorption, the hourly exposure flux (microgram/cm2/hr) was 0.03 +/- 0.01 for the 0.03 mg dose (3 micrograms/cm2). Increasing the dose approximately 15-fold to 0.43 mg (43 micrograms/cm2) resulted in a 10-fold increase in flux to 0.3 microgram/cm2/hr. Increasing the dose a further 70-fold to 30.7 mg (3070 micrograms/cm2) resulted in only another 21-fold increase in flux (6.3 +/- 1.8 micrograms/cm2/hr). Thus, the efficiency of absorption (%) decreased with increased topical dose, but the amount (mass/flux) of acetochlor absorbed always increased with increased dose. Plasma levels of topical acetochlor at the high dose were detectable at 1 hr and continued at a relatively steady level through the 24-hr dosing period. After the skin surface wash (24 hr) plasma levels decreased but were still detectable at the last 168-hr sampling period. Acetochlor, recently EPA approved as an herbicide for corn crops, is carcinogenic; however, farmers will use half as much acetochlor/acre as other herbicides. The percutaneous absorption of acetochlor is equal to that

  9. Mammography-oncogenecity at low doses.

    PubMed

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

    2009-06-01

    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

  10. Computing effective dose in cardiac CT

    NASA Astrophysics Data System (ADS)

    Huda, Walter; Tipnis, Sameer; Sterzik, Alexander; Schoepf, U. Joseph

    2010-07-01

    We present a method of estimating effective doses in cardiac CT that accounts for selected techniques (kV mAs-1), anatomical location of the scan and patient size. A CT dosimetry spreadsheet (ImPACT CT Patient Dosimetry Calculator) was used to estimate effective doses (E) using ICRP 103 weighting factors for a 70 kg patient undergoing cardiac CT examinations. Using dose length product (DLP) for the same scans, we obtained values of E/DLP for three CT scanners used in cardiac imaging from two vendors. E/DLP ratios were obtained as a function of the anatomical location in the chest and for x-ray tube voltages ranging from 80 to 140 kV. We also computed the ratio of the average absorbed dose in a water cylinder modeling a patient weighing W kg to the corresponding average absorbed dose in a water cylinder equivalent to a 70 kg patient. The average E/DLP for a 16 cm cardiac heart CT scan was 26 µSv (mGy cm)-1, which is about 70% higher than the current E/DLP values used for chest CT scans (i.e. 14-17 µSv (mGy cm)-1). Our cardiac E/DLP ratios are higher because the cardiac region is ~30% more radiosensitive than the chest, and use of the ICRP 103 tissue weighting factors increases cardiac CT effective doses by ~30%. Increasing the x-ray tube voltage from 80 to 140 kV increases the E/DLP conversion factor for cardiac CT by 17%. For the same incident radiation at 120 kV, doses in 45 kg adults were ~22% higher than those in 70 kg adults, whereas doses in 120 kg adults were ~28% lower. Accurate estimates of the patient effective dose in cardiac CT should use ICRP 103 tissue weighting factors, and account for a choice of scan techniques (kV mAs-1), exposed scan region, as well as patient size.

  11. Paediatric personnel extremity dose study.

    PubMed

    Gallet, J M C; Reed, M H

    2002-03-01

    Concern has been expressed in paediatric radiology regarding the magnitude of the extremity dose received by attending personnel during routine fluoroscopic procedures and CT. Common procedures that may be of short duration in adults can be quite the opposite in paediatric patients. The extremities of attending personnel are more likely to be exposed to the primary beam and for a longer period of time owing to a variety of reasons such as assisting in the procedure or physically restraining the patient during the examination. During the period mid 1998 to mid 2000, two paediatric radiologists, four senior radiographers and two paediatric nurses were monitored using ring thermoluminescent dosemeters (TLDs). Each participant wore the ring TLD on either the left or right ring finger, depending on which hand the individual favoured. Left/right asymmetrical studies were not conducted, nor were records kept of whether an examination used a grid or gridless technique. Initial apprehension about higher paediatric fluoroscopic and CT extremity doses was dispelled as a result of this quantitative dosimetric study. PMID:11932219

  12. Low-Dose Carcinogenicity Studies

    EPA Science Inventory

    One of the major deficiencies of cancer risk assessments is the lack of low-dose carcinogenicity data. Most assessments require extrapolation from high to low doses, which is subject to various uncertainties. Only 4 low-dose carcinogenicity studies and 5 low-dose biomarker/pre-n...

  13. LADTAPXL Aqueous Dose Spreadsheet

    1999-08-10

    LADTAPXL is an EXCEL spreadsheet model of the NRC computer code LADTAP. LADTAPXL calculates maximally exposed individual and population doses from chronic liquid releases. Environmental pathways include external exposure resulting from recreational activities on the Savannah River and ingestion of water, fish, and invertebrates of Savannah River origin.

  14. New Antibiotic Dosing

    PubMed Central

    Pineda, Leslie C.; Watt, Kevin M.

    2015-01-01

    Infection is common in premature infants and can cause significant morbidity and mortality. To prevent these devastating consequences, most infants admitted to the neonatal intensive care unit (NICU) are exposed to antibiotics. However, dosing regimens are often extrapolated from data in adults and older children, increasing the risk for drug toxicity and lack of clinical efficacy because they fail to account for developmental changes in infant physiology. Despite legislation promoting and, in some cases, requiring pediatric drug studies, infants remain therapeutic orphans who often receive drugs "off-label" without data from clinical trials. Pharmacokinetic (PK) studies in premature infants have been scarce due to low study consent rates; limited blood volume available to conduct PK studies; difficulty in obtaining blood from infants; limited use of sensitive, low-volume drug concentration assays; and a lack of expertise in pediatric modeling and simulation. However, newer technologies are emerging with minimal-risk study designs, including ultra-low-volume assays, PK modeling and simulation, and opportunistic drug protocols. With minimal-risk study designs, PK data and dosing regimens for infants are now available for antibiotics commonly used in the NICU, including ampicillin, clindamycin, meropenem, metronidazole, and piperacillin/tazobactam. The discrepancy between previous dosing recommendations extrapolated from adult data and newer dosing regimens based on infant PK studies highlights the need to conduct PK studies in premature infants. PMID:25678003

  15. Dose specification for radiation therapy: dose to water or dose to medium?

    PubMed

    Ma, C-M; Li, Jinsheng

    2011-05-21

    The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis. PMID:21508447

  16. Higher than Everest

    NASA Astrophysics Data System (ADS)

    Hodge, Paul

    2001-08-01

    Tired of exploring planet Earth? Have you ever imagined what it would be like to explore the Moon? Ever wonder about the topography of Mars? In this unique guidebook all of your extraterrestrial wanderlust can be fulfilled as Paul Hodge takes you on a virtual tour of the most spectacular sites in the Solar System. Hodge includes the latest information about the Solar System into his vivid descriptions of imaginary, challenging expeditions. Imagine: -- Descending into a fabulous canyon on Mars, one that dwarfs the Earth's Grand Canyon; -- Trekking up Venus' precipitous and scorching Mt. Maxwell; -- Journeying through the snows of Saturn's rings and the incredibly high, icy cliff of Miranda, the moon closest to Uranus. A compelling, extensively illustrated introduction to such otherworldly environments, Higher than Everest makes you believe that someday these adventures may actually take place. Paul Hodge is Professor of Astronomy at the University of Washington, Seattle, and Editor-in-Chief of the Astronomical Journal. Higher than Everest is based on a popular undergraduate course on the planets that he has taught for many years. Hodge's research has spanned from interplanetary dust to the extragalactic distance scale and currently includes star-formation and galactic evolution, using the Hubble Space Telescope to investigate nearby galaxies. He has written several books, most recently Meteorite Craters and Impact Structures of the Earth (Cambridge 1994).

  17. When is a dose not a dose

    SciTech Connect

    Bond, V.P.

    1991-01-01

    Although an enormous amount of progress has been made in the fields of radiation protection and risk assessment, a number of significant problems remain. The one problem which transcends all the rest, and which has been subject to considerable misunderstanding, involves what has come to be known as the 'linear non-threshold hypothesis', or 'linear hypothesis'. Particularly troublesome has been the interpretation that any amount of radiation can cause an increase in the excess incidence of cancer. The linear hypothesis has dominated radiation protection philosophy for more than three decades, with enormous financial, societal and political impacts and has engendered an almost morbid fear of low-level exposure to ionizing radiation in large segments of the population. This document presents a different interpretation of the linear hypothesis. The basis for this view lies in the evolution of dose-response functions, particularly with respect to their use initially in the context of early acute effects, and then for the late effects, carcinogenesis and mutagenesis. 11 refs., 4 figs. (MHB)

  18. Dose-dependent changes in the locomotor responses to methamphetamine in BALB/c mice: Low doses induce hypolocomotion

    PubMed Central

    Singh, Rana A. K.; Kosten, Therese A.; Kinsey, Berma M.; Shen, Xiaoyun; Lopez, Angel Y.; Kosten, Thomas R.; Orson, Frank M.

    2012-01-01

    The overall goal of the present study was to determine the effects of different doses of (+)-methamphetamine (meth) on locomotor activity of Balb/C mice. Four experiments were designed to test a wide range of meth doses in BALB/c female mice. In Experiment 1, we examined locomotor activity induced by an acute administration of low doses of meth (0.01 and 0.03 mg/kg) in a 90-min session. Experiment 2 was conducted to test higher meth doses (0.3 – 10 mg/kg). In Experiment 3, separate sets of mice were pre-treated with various meth doses once or twice (one injection/week) prior to a locomotor challenge with a low meth dose. Finally, in Experiment 4, we tested whether locomotor activation would be affected by pretreatment with a low or moderate dose of meth one month prior to the low meth dose challenge. Results show that low doses of meth induce hypolocomotion whereas moderate to high doses induce hyperlocomotion. Prior exposure to either one moderate or high dose of meth or to two, low doses of meth attenuated the hypolocomotor effect of a low meth dose one week later. This effect was also attenuated in mice tested one month after administration of a moderate meth dose. These results show that low and high doses of meth can have opposing effects on locomotor activity. Further, prior exposure to the drug leads to tolerance, rather than sensitization, of the hypolocomotor response to low meth doses. PMID:23010423

  19. Teaching at higher levels

    NASA Astrophysics Data System (ADS)

    1998-11-01

    Undergraduate physics programmes for the 21st century were under discussion at a recent event held in Arlington, USA, open to two or three members of the physics faculties of universities from across the whole country. The conference was organized by the American Association of Physics Teachers with co-sponsorship from the American Institute of Physics, the American Physical Society and Project Kaleidoscope. Among the various aims were to learn about physics departments that have successfully revitalized their undergraduate physics programmes with innovative introductory physics courses and multi-track majors programmes. Engineers and life scientists were to be asked directly how physics programmes can better serve their students, and business leaders would be speaking on how physics departments can help to prepare their students for the diverse careers that they will eventually follow. It was planned to highlight ways that departments could fulfil their responsibilities towards trainee teachers, to identify the resources needed for revitalizing a department's programme, and to develop guidelines and recommendations for a funding programme to support collaborative efforts among physics departments for carrying out the enhancements required. More details about the conference can be found on the AAPT website (see http://www.aapt.org/programs/rupc.html). Meanwhile the UK's Higher Education Funding Council has proposed a two-pronged approach to the promotion of high quality teaching and learning, as well as widening participation in higher education from 1999-2000. A total of £60m should be available to support these initiatives by the year 2001-2002. As part of this scheme the Council will invite bids from institutions to support individual academics in enhancing learning and teaching, as well as in recognition of individual excellence. As with research grants, such awards would enable staff to pursue activities such as the development of teaching materials

  20. Ir-192 HDR transit dose and radial dose function determination using alanine/EPR dosimetry.

    PubMed

    Calcina, Carmen S Guzmán; de Almeida, Adelaide; Rocha, José R Oliveira; Abrego, Felipe Chen; Baffa, Oswaldo

    2005-03-21

    Source positioning close to the tumour in high dose rate (HDR) brachytherapy is not instantaneous. An increment of dose will be delivered during the movement of the source in the trajectory to its static position. This increment is the transit dose, often not taken into account in brachytherapeutic treatment planning. The transit dose depends on the prescribed dose, number of treatment fractions, velocity and activity of the source. Combining all these factors, the transit dose can be 5% higher than the prescribed absorbed dose value (Sang-Hyun and Muller-Runkel, 1994 Phys. Med. Biol. 39 1181-8, Nath et al 1995 Med. Phys. 22 209-34). However, it cannot exceed this percentage (Nath et al 1995). In this work, we use the alanine-EPR (electron paramagnetic resonance) dosimetric system using analysis of the first derivative of the signal. The transit dose was evaluated for an HDR system and is consistent with that already presented for TLD dosimeters (Bastin et al 1993 Int. J. Radiat. Oncol. Biol. Phys. 26 695-702). Also using the same dosimetric system, the radial dose function, used to evaluate the geometric dose degradation around the source, was determined and its behaviour agrees better with those obtained by Monte Carlo simulations (Nath et al 1995, Williamson and Nath 1991 Med. Phys. 18 434-48, Ballester et al 1997 Med. Phys. 24 1221-8, Ballester et al 2001 Phys. Med. Biol. 46 N79-90) than with TLD measurements (Nath et al 1990 Med. Phys. 17 1032-40). PMID:15798311

  1. Analysis of decay dose rates and dose management in the National Ignition Facility.

    PubMed

    Khater, Hesham; Brereton, Sandra; Dauffy, Lucile; Hall, Jim; Hansen, Luisa; Kim, Soon; Kohut, Tom; Pohl, Bertram; Sitaraman, Shiva; Verbeke, Jerome; Young, Mitchell

    2013-06-01

    A detailed model of the Target Bay (TB) at the National Ignition Facility (NIF) has been developed to estimate the post-shot radiation environment inside the facility. The model includes the large number of structures and diagnostic instruments present inside the TB. These structures and instruments are activated by neutrons generated during a shot, and the resultant gamma dose rates are estimated at various decay times following the shot. A set of computational tools was developed to help in estimating potential radiation exposure to TB workers. The results presented in this paper describe the expected radiation environment inside the TB following a low-yield DT shot of 10(16) neutrons. General environment dose rates drop below 30 μSv h(-1) within 3 h following a shot, with higher dose rates observed in the vicinity (~30 cm) of few components. The dose rates drop by more than a factor of two at 1 d following the shot. Dose rate maps of the different TB levels were generated to aid in estimating worker stay-out times following a shot before entry is permitted into the TB. Primary components, including the Target Chamber and diagnostic and beam line components, are constructed of aluminum. Near-term TB accessibility is driven by the decay of the aluminum activation product, 24Na. Worker dose is managed using electronic dosimeters (EDs) self-issued at kiosks using commercial dose management software. The software programs the ED dose and dose rate alarms based on the Radiological Work Permit (RWP) and tracks dose by individual, task, and work group. PMID:23629063

  2. Higher-dimensional targeting

    SciTech Connect

    Kostelich, E.J. ); Grebogi, C. Department of Mathematics and Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 ); Ott, E. Department of Electrical Engineering, University of Maryland, College Park, Maryland 20742 ); Yorke, J.A. )

    1993-01-01

    This paper describes a procedure to steer rapidly successive iterates of an initial condition on a chaotic attractor to a small target region about any prespecified point on the attractor using only small controlling perturbations. Such a procedure is called targeting.'' Previous work on targeting for chaotic attractors has been in the context of one- and two-dimensional maps. Here it is shown that targeting can also be done in higher-dimensional cases. The method is demonstrated with a mechanical system described by a four-dimensional mapping whose attractor has two positive Lyapunov exponents and a Lyapunov dimension of 2.8. The target is reached by making very small successive changes in a single control parameter. In one typical case, 35 iterates on average are required to reach a target region of diameter 10[sup [minus]4], as compared to roughly 10[sup 11] iterates without the use of the targeting procedure.

  3. Semistrict higher gauge theory

    NASA Astrophysics Data System (ADS)

    Jurčo, Branislav; Sämann, Christian; Wolf, Martin

    2015-04-01

    We develop semistrict higher gauge theory from first principles. In particular, we describe the differential Deligne cohomology underlying semistrict principal 2-bundles with connective structures. Principal 2-bundles are obtained in terms of weak 2-functors from the Čech groupoid to weak Lie 2-groups. As is demonstrated, some of these Lie 2-groups can be differentiated to semistrict Lie 2-algebras by a method due to Ševera. We further derive the full description of connective structures on semistrict principal 2-bundles including the non-linear gauge transformations. As an application, we use a twistor construction to derive superconformal constraint equations in six dimensions for a non-Abelian tensor multiplet taking values in a semistrict Lie 2-algebra.

  4. Higher dimensional massive bigravity

    NASA Astrophysics Data System (ADS)

    Do, Tuan Q.

    2016-08-01

    We study higher-dimensional scenarios of massive bigravity, which is a very interesting extension of nonlinear massive gravity since its reference metric is assumed to be fully dynamical. In particular, the Einstein field equations along with the following constraint equations for both physical and reference metrics of a five-dimensional massive bigravity will be addressed. Then, we study some well-known cosmological spacetimes such as the Friedmann-Lemaitre-Robertson-Walker, Bianchi type I, and Schwarzschild-Tangherlini metrics for the five-dimensional massive bigravity. As a result, we find that massive graviton terms will serve as effective cosmological constants in both physical and reference sectors if a special scenario, in which reference metrics are chosen to be proportional to physical ones, is considered for all mentioned metrics. Thanks to the constancy property of massive graviton terms, consistent cosmological solutions will be figured out accordingly.

  5. Preconditioning is hormesis part II: How the conditioning dose mediates protection: Dose optimization within temporal and mechanistic frameworks.

    PubMed

    Calabrese, Edward J

    2016-08-01

    In Part I, hormetic doses of a variety of agents stimulated adaptive responses that conditioned and protected cells against the subsequent toxicity resulting from a second, higher dose (called a challenging dose) of the same or different agents. Herein (Part II), the optimal conditioning (hormetic) doses of many agents are documented, cellular mechanisms and temporal profiles are examined from which the conditioning (hormetic) responses are elicited, and the optimal conditioning doses are compared to the levels at which optimal protection occurs in response to the toxic challenge dose. Entry criteria for study evaluation required a conditioning mechanism-induced endpoint response, an hormetic/biphasic dose response for the protective response following the challenging dose, and a mechanistic assessment of how the conditioning dose afforded protection against a toxic challenging dose. The conditioning dose that demonstrated the largest increase in a mechanism-related conditioning (hormetic) response (i.e., prior to administration of the challenging dose) was the same dose that was optimally protective following the challenging dose. Specific receptor antagonists and/or inhibitors of cell signaling pathways which blocked the induction of conditioning (hormetic) effects during the conditioning period abolished the protective effects following the application of a challenge dose, thus identifying a specific and essential component of the hormetic mechanism. Conditioning responses often had sufficient doses to assess the nature of the dose response. In each of the cases these mechanism-based endpoints displayed an hormetic dose response. The present analysis reveals that hormetic biphasic dose responses were associated with both the conditioning process and the protective effects elicited following the challenging dose. Furthermore, based on optimal dosage, temporal relationships and the known mediating actions of receptor-based and/or cell signaling-based mechanisms

  6. High-Dose Menaquinone-7 Supplementation Reduces Cardiovascular Calcification in a Murine Model of Extraosseous Calcification

    PubMed Central

    Scheiber, Daniel; Veulemans, Verena; Horn, Patrick; Chatrou, Martijn L.; Potthoff, Sebastian A.; Kelm, Malte; Schurgers, Leon J.; Westenfeld, Ralf

    2015-01-01

    Cardiovascular calcification is prevalent in the aging population and in patients with chronic kidney disease (CKD) and diabetes mellitus, giving rise to substantial morbidity and mortality. Vitamin K-dependent matrix Gla-protein (MGP) is an important inhibitor of calcification. The aim of this study was to evaluate the impact of high-dose menaquinone-7 (MK-7) supplementation (100 µg/g diet) on the development of extraosseous calcification in a murine model. Calcification was induced by 5/6 nephrectomy combined with high phosphate diet in rats. Sham operated animals served as controls. Animals received high or low MK-7 diets for 12 weeks. We assessed vital parameters, serum chemistry, creatinine clearance, and cardiac function. CKD provoked increased aortic (1.3 fold; p < 0.05) and myocardial (2.4 fold; p < 0.05) calcification in line with increased alkaline phosphatase levels (2.2 fold; p < 0.01). MK-7 supplementation inhibited cardiovascular calcification and decreased aortic alkaline phosphatase tissue concentrations. Furthermore, MK-7 supplementation increased aortic MGP messenger ribonucleic acid (mRNA) expression (10-fold; p < 0.05). CKD-induced arterial hypertension with secondary myocardial hypertrophy and increased elastic fiber breaking points in the arterial tunica media did not change with MK-7 supplementation. Our results show that high-dose MK-7 supplementation inhibits the development of cardiovascular calcification. The protective effect of MK-7 may be related to the inhibition of secondary mineralization of damaged vascular structures. PMID:26295257

  7. Dose-dependent effects of the herbicide mesotrione on soil cyanobacterial communities.

    PubMed

    Crouzet, Olivier; Wiszniowski, Jarosław; Donnadieu, Florence; Bonnemoy, Frédérique; Bohatier, Jacques; Mallet, Clarisse

    2013-01-01

    This study aimed to investigate the dose-response effects of an herbicide on soil photosynthetic microbial communities, particularly cyanobacteria, using a microcosm approach. Pure mesotrione (active ingredient), and Callisto (a commercial formulation of this triketone herbicide), were spread at different rates on soil microcosm surfaces. Soil Chlorophyll concentrations were quantified to assess the photosynthetic biomass, and the genetic structure and diversity of the cyanobacterial community were investigated by a group-specific polymerase chain reaction followed by denaturing gradient gel electrophoresis. Dose-dependent responses were evidenced for both functional and structural parameters. No effect was detected in soils treated with 1 × AR (1-fold recommended application rate) irrespective of the herbicide formulation. At 10 × AR (10-fold recommended application rate), only Callisto treatment induced significant decreases of photosynthetic biomass, whereas structural parameters were less affected. At the 100 × AR (100-fold recommended application rate), both pure mesotrione and Callisto had strong negative impacts on soil chlorophyll concentrations and cyanobacterial genetic structure and diversity. At both the 10 × AR and 100 × AR treatments, Callisto induced significant stronger effects than pure mesotrione. In addition, indicators of photosynthetic biomass, compared with structural parameters of cyanobacterial communities (within 14 days), responded (within 7 days) more quickly to herbicide stress. The results of this study underscore the relevance of soil photosynthetic microbial communities to develop indicators for herbicide risk assessment. PMID:23014935

  8. Phenobarbital plasma level/dose ratio in monotherapy. Influence of age, sex and dose.

    PubMed

    Durán, J A; Sánchez, A; Serrano, M I; Serrano, J S

    1988-05-01

    Phenobarbital plasma level/dose ratio (L/D) has been studied in 536 outpatients distributed in groups according to age, sex and drug dosage. Samples were obtained prior to the first morning dose. Plasma levels that correspond to the steady-state phase were determined by homogeneous enzymatic immunoassay (EMITR). From the results it must be pointed out: 1) An increase of L/D as the age increases within each group; 2) A decrease of L/D as the dose of phenobarbital increases in the overall sample; 3) Sex does not affect L/D in any of the subgroups studied; 4) For a given dose higher blood levels are reached in children 7 to 15 years old in our sample than in other comparable studies in Spain. PMID:3398650

  9. Iodine-129 Dose in LLW Disposal Facility Performance Assessments

    SciTech Connect

    Wilhite, E.L.

    1999-10-15

    Iodine-129 has the lowest Performance Assessment derived inventory limit in SRS disposal facilities. Because iodine is concentrated in the body to one organ, the thyroid, it has been thought that dilution with stable iodine would reduce the dose effects of 129I.Examination of the dose model used to establish the Dose conversion factor for 129I shows that, at the levels considered in performance assessments of low-level waste disposal facilities, the calculated 129I dose already accounts for ingestion of stable iodine. At higher than normal iodine ingestion rates, the uptake of iodine by the thyroid itself decrease, which effectively cancels out the isotopic dilution effect.

  10. Higher prices in Jamaica.

    PubMed

    1982-03-01

    Price increases in the Jamaica CSM program went into effect on August 31, 1981. The program began in 1975. While the need for higher prices has been under discussion for the past 3 years, this is the 1st time the requisite approval from the Jamaica Price Commission has been obtained. The Jamaica National Family Planning Board (JNFPB) reports that the Panther 3-pack (condom) is up US$0.15 to US$0.30. Each Perle package (oral contraceptive) was increased by US$0.20. Single cycle Perle now sells for US$0.50, and 3-pack Perle sells for US$1.10. The 6-year price stagnation experienced by the CSM program resulted in a decreasing operational budget as program costs continued to rise. Marketing costs alone during this period escalated by 100-300%. For example, Panther pop-up display cartons cost the project US 16U each in 1975. By 1979 the same product cost US 49U. Newspaper advertisements have increased from the 1975 cost of US$68.00 to nearly $200.00 per placement. The overall inflation rate in Jamaica during the last 5 years has averaged more than 20% annually. In the face of these rising costs, outlet expansion for Perle has been prevented, wholesaler margins have been unavailable, and new retailer training has been discontinued. It is projected that the new prices will result in an annual increased revenues of US$80,000 which will be used to reinstate these essential marketing activities. The JNFPB is also planning to introduce a Panther 12-pack and Panther strips to the CSM product line. According to Marketing Manager Aston Evans, "We believe the public is now ready for this type of packaging" which is scheduled to be available soon. Panther is presently only available in a 3-pack, but annual sales have been steady. The new 12-pack will be stocked on supermarket shelves to provide higher product visibility and wider distribution. The selling price has been set as US$1.20 and is expected to yield a 25% increase in sales during the 1st year. A complete sales promotion

  11. Radiation dose rate meter

    SciTech Connect

    Kronenberg, S.; Siebentritt, C.R.

    1981-07-28

    A combined dose rate meter and charger unit therefor which does not require the use of batteries but on the other hand produces a charging potential by means of a piezoelectric cylinder which is struck by a manually triggered hammer mechanism. A tubular type electrometer is mounted in a portable housing which additionally includes a geiger-muller (Gm) counter tube and electronic circuitry coupled to the electrometer for providing multi-mode operation. In one mode of operation, an rc circuit of predetermined time constant is connected to a storage capacitor which serves as a timed power source for the gm tube, providing a measurement in terms of dose rate which is indicated by the electrometer. In another mode, the electrometer indicates individual counts.

  12. Lactobacillus rhamnosus GG Activation of Dendritic Cells and Neutrophils Depends on the Dose and Time of Exposure

    PubMed Central

    Bay, Boon Huat

    2016-01-01

    This study evaluates the ability of Lactobacillus rhamnosus GG (LGG) to activate DC and neutrophils and modulate T cell activation and the impact of bacterial dose on these responses. Murine bone marrow derived DC or neutrophils were stimulated with LGG at ratios of 5 : 1, 10 : 1, and 100 : 1 (LGG : cells) and DC maturation (CD40, CD80, CD86, CD83, and MHC class II) and cytokine production (IL-10, TNF-α, and IL-12p70) were examined after 2 h and 18 h coculture and compared to the ability of BCG (the present immunotherapeutic agent for bladder cancer) to stimulate these cells. A 2 h exposure to 100 : 1 (high dose) or an 18 h exposure to 5 : 1 or 10 : 1 (low dose), LGG : cells, induced the highest production of IL-12 and upregulation of CD40, CD80, CD86, and MHC II on DC. In DCs stimulated with LGG activated neutrophils IL-12 production decreased with increasing dose. LGG induced 10-fold greater IL-12 production than BCG. T cell IFNγ and IL-2 production was significantly greater when stimulated with DC activated with low dose LGG. In conclusion, DC or DC activated with neutrophils exposed to low dose LGG induced greater Th1 polarization in T cells and this could potentially exert stronger antitumor effects. Thus the dose of LGG used for immunotherapy could determine treatment efficacy. PMID:27525288

  13. Molecular Detection of Leptospira in Two Returned Travelers: Higher Bacterial Load in Cerebrospinal Fluid versus Serum or Plasma

    PubMed Central

    Waggoner, Jesse J.; Soda, Elizabeth A.; Seibert, Ryan; Grant, Philip; Pinsky, Benjamin A.

    2015-01-01

    Leptospirosis is a potentially severe illness in returned travelers. Patients often present with fever, headache, and neck pain, which may lead to a workup for meningitis including the acquisition of cerebrospinal fluid (CSF). Although Leptospira DNA has been detected in CSF by polymerase chain reaction (PCR), little data exist regarding the utility of testing CSF in addition to serum or plasma obtained on presentation. In this report, we present two cases of leptospirosis in returned travelers presenting with fever and headache. Our first patient had neutrophilic meningitis, and Leptospira was detectable only in CSF obtained on admission. The second patient had a normal CSF profile, but Leptospira was detected in CSF at a bacterial load 5- to 10-fold higher than that in plasma. CSF is an important specimen for the diagnosis of Leptospira by molecular methods and may yield an actionable diagnosis in the absence of leptospiremia. PMID:26033024

  14. Molecular Detection of Leptospira in Two Returned Travelers: Higher Bacterial Load in Cerebrospinal Fluid Versus Serum or Plasma.

    PubMed

    Waggoner, Jesse J; Soda, Elizabeth A; Seibert, Ryan; Grant, Philip; Pinsky, Benjamin A

    2015-08-01

    Leptospirosis is a potentially severe illness in returned travelers. Patients often present with fever, headache, and neck pain, which may lead to a workup for meningitis including the acquisition of cerebrospinal fluid (CSF). Although Leptospira DNA has been detected in CSF by polymerase chain reaction (PCR), little data exist regarding the utility of testing CSF in addition to serum or plasma obtained on presentation. In this report, we present two cases of leptospirosis in returned travelers presenting with fever and headache. Our first patient had neutrophilic meningitis, and Leptospira was detectable only in CSF obtained on admission. The second patient had a normal CSF profile, but Leptospira was detected in CSF at a bacterial load 5- to 10-fold higher than that in plasma. CSF is an important specimen for the diagnosis of Leptospira by molecular methods and may yield an actionable diagnosis in the absence of leptospiremia. PMID:26033024

  15. Estimation of the Dose and Dose Rate Effectiveness Factor

    NASA Technical Reports Server (NTRS)

    Chappell, L.; Cucinotta, F. A.

    2013-01-01

    Current models to estimate radiation risk use the Life Span Study (LSS) cohort that received high doses and high dose rates of radiation. Transferring risks from these high dose rates to the low doses and dose rates received by astronauts in space is a source of uncertainty in our risk calculations. The solid cancer models recommended by BEIR VII [1], UNSCEAR [2], and Preston et al [3] is fitted adequately by a linear dose response model, which implies that low doses and dose rates would be estimated the same as high doses and dose rates. However animal and cell experiments imply there should be curvature in the dose response curve for tumor induction. Furthermore animal experiments that directly compare acute to chronic exposures show lower increases in tumor induction than acute exposures. A dose and dose rate effectiveness factor (DDREF) has been estimated and applied to transfer risks from the high doses and dose rates of the LSS cohort to low doses and dose rates such as from missions in space. The BEIR VII committee [1] combined DDREF estimates using the LSS cohort and animal experiments using Bayesian methods for their recommendation for a DDREF value of 1.5 with uncertainty. We reexamined the animal data considered by BEIR VII and included more animal data and human chromosome aberration data to improve the estimate for DDREF. Several experiments chosen by BEIR VII were deemed inappropriate for application to human risk models of solid cancer risk. Animal tumor experiments performed by Ullrich et al [4], Alpen et al [5], and Grahn et al [6] were analyzed to estimate the DDREF. Human chromosome aberration experiments performed on a sample of astronauts within NASA were also available to estimate the DDREF. The LSS cohort results reported by BEIR VII were combined with the new radiobiology results using Bayesian methods.

  16. [Quality control dose calibrators].

    PubMed

    Montoza Aguado, M; Delgado García, A; Ramírez Navarro, A; Salgado García, C; Muros de Fuentes, M A; Ortega Lozano, S; Bellón Guardia, M E; Llamas Elvira, J M

    2004-01-01

    We have reviewed the legislation about the quality control of dose calibrator. The importance of verifying the correct work of these instruments, is fundamental in daily practice of radiopharmacy and nuclear medicine. The Spanish legislation establishes to include these controls as part of the quality control of radiopharmaceuticals, and the program of quality assurance in nuclear medicine. We have reviewed guides and protocols from international eminent organizations, summarizing the recommended tests and periodicity of them. PMID:15625064

  17. Impact of microscopic disease extension, extra-CTV tumour islets, incidental dose and dose conformity on tumour control probability.

    PubMed

    Selvaraj, Jothybasu; Baker, Colin; Nahum, Alan

    2016-06-01

    The impact of microscopic disease extension (MDE), extra-CTV tumour islets (TIs), incidental dose and dose conformity on tumour control probability (TCP) is analyzed using insilico simulations in this study. MDE in the region in between GTV and CTV is simulated inclusive of geometric uncertainties (GE) using spherical targets and spherical dose distribution. To study the effect of incidental dose on TIs and the effect of dose-response curve (DRC) on tumour control, islets were randomly distributed and TCP was calculated for various dose levels by rescaling the dose. Further, the impact of dose conformity on required PTV margins is also studied. The required PTV margins are ~2 mm lesser than assuming a uniform clonogen density if an exponential clonogen density fall off in the GTV-CTV is assumed. However, margins are almost equal if GE is higher in both cases. This shows that GE has a profound impact on margins. The effect of TIs showed a bi-phasic relation with increasing dose, indicating that patients with islets not in the beam paths do not benefit from dose escalation. Increasing dose conformity is also found to have considerable effect on TCP loss especially for larger GE. Further, smaller margins in IGRT should be used with caution where uncertainty in CTV definition is of concern. PMID:27168065

  18. Dose esclation in radioimmunotherapy based on projected whole body dose

    SciTech Connect

    Wahl, R.L.; Kaminski, M.S.; Regan, D.

    1994-05-01

    A variety of approaches have been utilized in conducting phase I radioimmunotherapy dose-escalation trials. Escalation of dose has been based on graded increases in administered mCi; mCi/kg; or mCi/m2. It is also possible to escalate dose based on tracer-projected marrow, blood or whole body radiation dose. We describe our results in performing a dose-escalation trial in patients with non-Hodgkin lymphoma based on escalating administered whole-body radiation dose. The mCi dose administered was based on a patient-individualized tracer projected whole-body dose. 25 patients were entered on the study. RIT with 131 I anti-B-1 was administered to 19 patients. The administered dose was prescribed based on the projected whole body dose, determined from patient-individualized tracer studies performed prior to RIT. Whole body dose estimates were based on the assumption that the patient was an ellipsoid, with 131 antibody kinetics determined using a whole-body probe device acquiring daily conjugate views of 1 minute duration/view. Dose escalation levels proceeded with 10 cGy increments from 25 cGy whole-body and continues, now at 75 cGy. The correlation among potential methods of dose escalation and toxicity was assessed. Whole body radiation dose by probe was strongly correlated with the blood radiation dose determined from sequential blood sampling during tracer studies (r=.87). Blood radiation dose was very weakly correlated with mCi dose (r=.4) and mCi/kg (r=.45). Whole body radiation dose appeared less well-correlated with injected dose in mCi (r=.6), or mCi/kg (r=.64). Toxicity has been infrequent in these patients, but appears related to increasing whole body dose. Non-invasive determination of whole-body radiation dose by gamma probe represents a non-invasive method of estimating blood radiation dose, and thus of estimating bone marrow radiation dose.

  19. Out-of-field doses and neutron dose equivalents for electron beams from modern Varian and Elekta linear accelerators.

    PubMed

    Cardenas, Carlos E; Nitsch, Paige L; Kudchadker, Rajat J; Howell, Rebecca M; Kry, Stephen F

    2016-01-01

    Out-of-field doses from radiotherapy can cause harmful side effects or eventually lead to secondary cancers. Scattered doses outside the applicator field, neutron source strength values, and neutron dose equivalents have not been broadly investigated for high-energy electron beams. To better understand the extent of these exposures, we measured out-of-field dose characteristics of electron applicators for high-energy electron beams on two Varian 21iXs, a Varian TrueBeam, and an Elekta Versa HD operating at various energy levels. Out-of-field dose profiles and percent depth-dose curves were measured in a Wellhofer water phantom using a Farmer ion chamber. Neutron dose was assessed using a combination of moderator buckets and gold activation foils placed on the treatment couch at various locations in the patient plane on both the Varian 21iX and Elekta Versa HD linear accelerators. Our findings showed that out-of-field electron doses were highest for the highest electron energies. These doses typically decreased with increasing distance from the field edge but showed substantial increases over some distance ranges. The Elekta linear accelerator had higher electron out-of-field doses than the Varian units examined, and the Elekta dose profiles exhibited a second dose peak about 20 to 30 cm from central-axis, which was found to be higher than typical out-of-field doses from photon beams. Electron doses decreased sharply with depth before becoming nearly constant; the dose was found to decrease to a depth of approximately E(MeV)/4 in cm. With respect to neutron dosimetry, Q values and neutron dose equivalents increased with electron beam energy. Neutron contamination from electron beams was found to be much lower than that from photon beams. Even though the neutron dose equivalent for electron beams represented a small portion of neutron doses observed under photon beams, neutron doses from electron beams may need to be considered for special cases. PMID:27455499

  20. Association of achieved dialysis dose with mortality in the hemodialysis study: an example of "dose-targeting bias".

    PubMed

    Greene, Tom; Daugirdas, John; Depner, Thomas; Allon, Michael; Beck, Gerald; Chumlea, Cameron; Delmez, James; Gotch, Frank; Kusek, John W; Levin, Nathan; Owen, William; Schulman, Gerald; Star, Robert; Toto, Robert; Eknoyan, Garabed

    2005-11-01

    In the intention-to-treat analysis of the Hemodialysis Study, all-cause mortality did not differ significantly between the high versus standard hemodialysis dose groups. The association of mortality with delivered dose within each of the two randomized treatment groups was examined, and implications for observational studies were considered. Time-dependent Cox regression was used to relate the relative risk (RR) for mortality to the running mean of the achieved equilibrated Kt/V (eKt/V) over the preceding 4 mo. eKt/V was categorized by quintiles within each dose group. Analyses were controlled for case-mix factors and baseline anthropometric volume. Within each randomized dose group, mortality was elevated markedly when achieved eKt/V was in the lowest quintile (RR, 1.93; 95% confidence interval [CI], 1.40 to 2.66; P < 0.0001 in the standard-dose group; RR, 2.04; 95% CI, 1.50 to 2.76; P < 0.0001 in the high-dose group; RR relative to the middle quintiles). The mortality rate in the lowest eKt/V quintile of the high-dose group was higher than in the full standard-dose group (RR, 1.59; 95% CI, 1.29 to 1.96; P < 0.0001). Each 0.1 eKt/V unit below the group median was associated with a 58% higher mortality in the standard-dose group (P < 0.001) and a 37% higher mortality in the high-dose group (P < 0.001). The magnitude of these dose-mortality effects was seven- to 12-fold higher than the upper limit of the 95% CI from the intention-to-treat analysis. The effects were attenuated in lagged analyses but did not disappear. When dialysis dose is targeted closely, as under the controlled conditions of the Hemodialysis Study, patients with the lowest achieved dose relative to their target dose experience markedly increased mortality, to a degree that is not compatible with a biologic effect of dose. The possibility of similar (albeit smaller) biases should be considered when analyzing observational data sets relating mortality to achieved dose of dialysis. PMID:16192421

  1. Texas Higher Education in Transition.

    ERIC Educational Resources Information Center

    Texas Coll. and Univ. System, Austin. Coordinating Board.

    The status of higher education in Texas is examined in this major report of changes in higher education over the past decade. Information on enrollment, cost, financial aid, job opportunities, and facilities in higher education institutions is given for private higher education, professional higher education, community colleges, and state colleges…

  2. Higher cancer risk continues after Chernobyl

    Cancer.gov

    Nearly 25 years after the accident at the Chernobyl nuclear power plant in Ukraine, exposure to radioactive iodine-131(I-131, a radioactive isotope) from fallout may be responsible for thyroid cancers that are still occurring among people who lived in the Chernobyl area and were children or adolescents at the time of the accident, researchers say. An international team of researchers led by the NCI found a clear dose-response relationship, in which higher absorption of radiation from I-131 led to an increased risk for thyroid cancer that has not seemed to diminish over time.

  3. Polyesters in higher plants.

    PubMed

    Kolattukudy, P E

    2001-01-01

    Polyesters occur in higher plants as the structural component of the cuticle that covers the aerial parts of plants. This insoluble polymer, called cutin, attached to the epidermal cell walls is composed of interesterified hydroxy and hydroxy epoxy fatty acids. The most common chief monomers are 10,16-dihydroxy C16 acid, 18-hydroxy-9,10 epoxy C18 acid, and 9,10,18-trihydroxy C18 acid. These monomers are produced in the epidermal cells by omega hydroxylation, in-chain hydroxylation, epoxidation catalyzed by P450-type mixed function oxidase, and epoxide hydration. The monomer acyl groups are transferred to hydroxyl groups in the growing polymer at the extracellular location. The other type of polyester found in the plants is suberin, a polymeric material deposited in the cell walls of a layer or two of cells when a plant needs to erect a barrier as a result of physical or biological stress from the environment, or during development. Suberin is composed of aromatic domains derived from cinnamic acid, and aliphatic polyester domains derived from C16 and C18 cellular fatty acids and their elongation products. The polyesters can be hydrolyzed by pancreatic lipase and cutinase, a polyesterase produced by bacteria and fungi. Catalysis by cutinase involves the active serine catalytic triad. The major function of the polyester in plants is as a protective barrier against physical, chemical, and biological factors in the environment, including pathogens. Transcriptional regulation of cutinase gene in fungal pathogens is being elucidated at a molecular level. The polyesters present in agricultural waste may be used to produce high value polymers, and genetic engineering might be used to produce large quantities of such polymers in plants. PMID:11217409

  4. Immunogenicity Following One, Two, or Three Doses of the 7-valent Pneumococcal Conjugate Vaccine

    PubMed Central

    Russell, FM; Balloch, A; Tang, MLK; Carapetis, JR; Licciardi, P; Nelson, J; Jenney, AWJ; Tikoduadua, L; Waqatakirewa, L; Pryor, J; Byrnes, GB; Cheung, YB; Mulholland, EK

    2009-01-01

    The aim was to identify an appropriate infant pneumococcal vaccination strategy for resource poor countries. Fijian infants received 0, 1, 2, or 3 doses of 7-valent pneumococcal conjugate vaccine (PCV) in early infancy. Following 3 PCV doses, geometric mean concentration (GMC) to all 7 serotypes were ≥ 1.0μg/mL, and >85% of children achieved antibody levels ≥0.35μg/mL at 18 weeks. Following 2 doses, GMC were lower for 6B, 14, and 23F, but higher for 19F compared with 3 doses. Following a single dose, significant responses were seen for all serotypes post primary series compared with the unvaccinated. By 12 months, differences between 2 and 3 doses persisted for serotype 14 only. Although GMC following 3 doses are higher than after 2 doses, the differences were small. A single dose may offer some protection for most serotypes. PMID:19616498

  5. Transplantation Dose Alters the Differentiation Program of Hematopoietic Stem Cells.

    PubMed

    Brewer, Casey; Chu, Elizabeth; Chin, Mike; Lu, Rong

    2016-05-24

    Hematopoietic stem cell (HSC) transplantation is the most prevalent stem cell therapy, but it remains a risky procedure. To improve this treatment, it is important to understand how transplanted stem cells rebuild the blood and immune systems and how this process is impacted by transplantation variables such as the HSC dose. Here, we find that, in the long term following transplantation, 70%-80% of donor-HSC-derived clones do not produce all measured blood cell types. High HSC doses lead to more clones that exhibit balanced lymphocyte production, whereas low doses produce more T-cell-specialized clones. High HSC doses also produce significantly higher proportions of early-differentiating clones compared to low doses. These complex differentiation behaviors uncover the clonal-level regeneration dynamics of hematopoietic regeneration and suggest that transplantation dose can be exploited to improve stem cell therapy. PMID:27184851

  6. Dose surveys and DRLs: critical look and way forward.

    PubMed

    Rehani, Madan M

    2015-07-01

    The main purpose of dose surveys has been to detect and bring down wide variation in radiation doses for any particular radiological examination and to avoid doses that are on higher side. Diagnostic reference levels (DRLs) have been used for over two decades as an aid in this objective. With very limited success that has been achieved through DRL, the author has recently described a new term 'acceptable quality dose' (AQD) that is aimed at optimisation within the DRL, is facility initiated and takes into account all three important parameters-image quality, dose and patient's body build. It is hoped that AQD will be found easy to establish, will be a useful tool to achieve optimisation in the facilities and will serve as the standard dose. PMID:25809110

  7. Use of cassette dosing to enhance the throughput of rat brain microdialysis studies.

    PubMed

    Deshmukh, Gauri; Sun, Kefeng; Liederer, Bianca M; Ding, Xiao; Liu, Xingrong

    2015-07-01

    This study was designed to increase the throughput of rat brain microdialysis studies by administration of compounds as a cassette as opposed to discrete study. Eight compounds (carbamazepine, citalopram, desmethylclozapine, diphenhydramine, gabapentin, metoclopramide, naltrexone, and stavudine) were selected and administered as an intravenous bolus dose at 0.5-3.3 mg/kg each followed by an intravenous infusion at 1 mg/kg per hour for 6 hours in rats in a cassette or discrete dosing. The dialysate, plasma, brain, and cerebrospinal fluid were collected and analyzed using liquid chromatography-tandem mass spectrometry. The microdialysis probe recovery was determined by an in vitro gain method. The recovery between the cassette and discrete dosing was similar, with an average of 1.0 ± 0.10-fold difference. The stavudine interstitial fluid (ISF) concentration, as measured by brain microdialysis, was below the low limit of quantitation and was excluded from the analyses. The ratios of ISF concentration to unbound plasma concentration were within 2-fold for six of the remaining seven compounds, with an average of 0.92 ± 0.51-fold difference between the cassette and discrete methods. The ratios of ISF concentration to unbound brain concentration, as measured by the brain homogenate method, were also similar, with a 1.1 ± 0.7-fold difference. In addition, the ratios of ISF to cerebrospinal fluid concentrations were similar, with a 1.5 ± 0.6-fold difference. The results from this study support the use of a cassette dosing approach to enhance the throughput of rat brain microdialysis studies in drug discovery. PMID:25943358

  8. Radiation dose to the lens and cataract formation

    SciTech Connect

    Henk, J.M.; Whitelocke, R.A.F.; Warrington, A.P.; Bessell, E.M. )

    1993-04-02

    The purpose of this work was to determine the radiation tolerance of the lens of the eye and the incidence of radiation-induced lens changes in patients treated by fractionated supervoltage radiation therapy for orbital tumors. Forty patients treated for orbital lymphoma and pseudotumor with tumor doses of 20--40 Gy were studied. The lens was partly shielded using lead cylinders in most cases. The dose to the germinative zone of the lens was estimated by measurements in a tissue equivalent phantom using both film densitometry and thermoluminescent dosimetry. Opthalmological examination was performed at 6 monthly intervals after treatment. The lead shield was found to reduce the dose to the germinative zone of the lens to between 36--50% of the tumor dose for Cobalt beam therapy, and to between 11--18% for 5 MeV x-rays. Consequently, the lens doses were in the range 4.5--30 Gy in 10--20 fractions. Lens opacities first appeared from between 3 and 9 years after irradiation. Impairment of visual acuity ensued in 74% of the patients who developed lens opacities. The incidence of lens changes was strongly dose-related. None was seen after doses of 5 Gy or lower, whereas doses of 16.5 Gy or higher were all followed by lens opacities which impaired visual acuity. The largest number of patients received a maximum lens dose of 15 Gy; in this group the actuarial incidence of lens opacities at 8 years was 57% with visual impairment in 38%. The adult lens can tolerate a total dose of 5 Gy during a fractionated course of supervoltage radiation therapy without showing any changes. Doses of 16.5 Gy or higher will almost invariably lead to visual impairment. The dose which causes a 50% probability of visual impairment is approximately 15 Gy. 10 refs., 4 figs., 1 tab.

  9. The Effects of ELDRS at Ultra-Low Dose Rates

    NASA Technical Reports Server (NTRS)

    Chen, Dakai; Forney, James; Carts, Martin; Phan, Anthony; Pease, Ronald; Kruckmeyer, Kirby; Cox, Stephen; LaBel, Kenneth; Burns, Samuel; Albarian, Rafi; Holcombe, Bruce; Little, Bradley; Salzman, James; Chaumont, Geraldine; Duperray, Herve; Ouellet, Al

    2011-01-01

    We present results on the effects on ELDRS at dose rates of 10, 5, 1, and 0.5 mrad(Si)/s for a variety of radiation hardened and commercial devices. We observed low dose rate enhancement below 10 mrad(Si)/s in several different parts. The magnitudes of the dose rate effects vary. The TL750L, a commercial voltage regulator, showed dose rate dependence in the functional failures, with initial failures occurring after 10 krad(Si) for the parts irradiated at 0.5 mrad(Si)/s. The RH1021 showed an increase in low dose rate enhancement by 2x at 5 mrad(Si)/s relative to 8 mrad(Si)/s and high dose rate, and parametric failure after 100 krad(Si). Additionally the ELDRS-free devices, such as the LM158 and LM117, showed evidence of dose rate sensitivity in parametric degradations. Several other parts also displayed dose rate enhancement, with relatively lower degradations up to approx.15 to 20 krad(Si). The magnitudes of the dose rate enhancement will likely increase in significance at higher total dose levels.

  10. Periodic CO2 Dosing Strategy for Dunaliella salina Batch Culture

    PubMed Central

    Ying, Kezhen; Gilmour, D. James; Zimmerman, William B.

    2015-01-01

    A periodic CO2 dosing strategy for D. salina 19/30 batch culture is proposed. A model of periodic CO2 dosing including dosing time calculation, dosing interval estimation and final chlorophyll yield prediction was established. In experiments, 5% CO2/95% N2 gas was periodically dosed into D. salina culture. Two different gas dosing flow rates were tested. The corresponding dosing time for each flow rate was estimated via the model (10 min·d−1 for 0.7 L·min−1 and 36 min·d−1 for 0.3 L·min−1). Daily pH measurements showed that the pH of these cultures dosed periodically was always kept between 7.5 and 9.5, which highlights that periodic gas supply can maintain a suitable range of pH for microalgal growth without expensive buffers. Notably the culture dosed for set daily intervals was seen to have similar growth to the culture supplied constantly, but with much higher CO2 capture efficiency (11%–18%) compared to continuous dosing (0.25%). It shows great potential for using periodic gas supply to reduce cost, wasted gas and energy use. PMID:25997005

  11. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Cannon, S.D.; Finch, S.M.

    1992-10-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  12. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-01-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  13. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1991-01-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport environmental monitoring data; demographics, agriculture, food habits; environmental pathways and dose estimates.

  14. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-02-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  15. Maximizing the biological effect of proton dose delivered with scanned beams via inhomogeneous daily dose distributions

    SciTech Connect

    Zeng Chuan; Giantsoudi, Drosoula; Grassberger, Clemens; Goldberg, Saveli; Niemierko, Andrzej; Paganetti, Harald; Efstathiou, Jason A.; Trofimov, Alexei

    2013-05-15

    Purpose: Biological effect of radiation can be enhanced with hypofractionation, localized dose escalation, and, in particle therapy, with optimized distribution of linear energy transfer (LET). The authors describe a method to construct inhomogeneous fractional dose (IFD) distributions, and evaluate the potential gain in the therapeutic effect from their delivery in proton therapy delivered by pencil beam scanning. Methods: For 13 cases of prostate cancer, the authors considered hypofractionated courses of 60 Gy delivered in 20 fractions. (All doses denoted in Gy include the proton's mean relative biological effectiveness (RBE) of 1.1.) Two types of plans were optimized using two opposed lateral beams to deliver a uniform dose of 3 Gy per fraction to the target by scanning: (1) in conventional full-target plans (FTP), each beam irradiated the entire gland, (2) in split-target plans (STP), beams irradiated only the respective proximal hemispheres (prostate split sagittally). Inverse planning yielded intensity maps, in which discrete position control points of the scanned beam (spots) were assigned optimized intensity values. FTP plans preferentially required a higher intensity of spots in the distal part of the target, while STP, by design, employed proximal spots. To evaluate the utility of IFD delivery, IFD plans were generated by rearranging the spot intensities from FTP or STP intensity maps, separately as well as combined using a variety of mixing weights. IFD courses were designed so that, in alternating fractions, one of the hemispheres of the prostate would receive a dose boost and the other receive a lower dose, while the total physical dose from the IFD course was roughly uniform across the prostate. IFD plans were normalized so that the equivalent uniform dose (EUD) of rectum and bladder did not increase, compared to the baseline FTP plan, which irradiated the prostate uniformly in every fraction. An EUD-based model was then applied to estimate tumor

  16. Impact of oral bisphenol A at reference doses on intestinal barrier function and sex differences after perinatal exposure in rats.

    PubMed

    Braniste, Viorica; Jouault, Aurore; Gaultier, Eric; Polizzi, Arnaud; Buisson-Brenac, Claire; Leveque, Mathilde; Martin, Pascal G; Theodorou, Vassilia; Fioramonti, Jean; Houdeau, Eric

    2010-01-01

    Bisphenol A (BPA), a chemical estrogen widely used in the food-packaging industry and baby bottles, is recovered in human fluids (0.1-10 nM). Recent studies have reported that BPA is hormonally active at low doses, emphasizing the debate of a risk for human health. Estrogen receptors are expressed in the colon, and although the major route of BPA exposure is food, the effects on gut have received no attention. We first examined the endocrine disrupting potency of BPA on colonic paracellular permeability (CPP), experimental colitis, and visceral sensitivity in ovariectomized rats orally exposed to 5 mg/kg/d BPA (i.e., the no observed adverse effect level), 50 microg/kg/d BPA (i.e., tolerable daily intake), or lower doses. BPA dose-dependently decreased basal CPP, with a half-maximal inhibitory dose of 5.2 microg/kg/d, 10-fold below the tolerable daily intake. This correlated with an increase in epithelial tight junction sealing, also observed in Caco-2 cells exposed to 10 nM BPA. When ovariectomized rats were fed with BPA at the no observed adverse effect level, the severity of colitis was reduced, whereas the same dose increased pain sensitivity to colorectal stimuli. We then examined the impact of perinatal exposure to BPA on intestinal permeability and inflammatory response in the offspring. In female rats, but not in male rats, perinatal BPA evoked a decrease of CPP in adulthood, whereas the proinflammatory response of colonic mucosa was strengthened. This study first demonstrates that the xenoestrogen BPA at reference doses influences intestinal barrier function and gut nociception. Moreover, perinatal exposure promotes the development of severe inflammation in adult female offspring only. PMID:20018722

  17. Radiation damage in single-particle cryo-electron microscopy: effects of dose and dose rate.

    PubMed

    Karuppasamy, Manikandan; Karimi Nejadasl, Fatemeh; Vulovic, Milos; Koster, Abraham J; Ravelli, Raimond B G

    2011-05-01

    Radiation damage is an important resolution limiting factor both in macromolecular X-ray crystallography and cryo-electron microscopy. Systematic studies in macromolecular X-ray crystallography greatly benefited from the use of dose, expressed as energy deposited per mass unit, which is derived from parameters including incident flux, beam energy, beam size, sample composition and sample size. In here, the use of dose is reintroduced for electron microscopy, accounting for the electron energy, incident flux and measured sample thickness and composition. Knowledge of the amount of energy deposited allowed us to compare doses with experimental limits in macromolecular X-ray crystallography, to obtain an upper estimate of radical concentrations that build up in the vitreous sample, and to translate heat-transfer simulations carried out for macromolecular X-ray crystallography to cryo-electron microscopy. Stroboscopic exposure series of 50-250 images were collected for different incident flux densities and integration times from Lumbricus terrestris extracellular hemoglobin. The images within each series were computationally aligned and analyzed with similarity metrics such as Fourier ring correlation, Fourier ring phase residual and figure of merit. Prior to gas bubble formation, the images become linearly brighter with dose, at a rate of approximately 0.1% per 10 MGy. The gradual decomposition of a vitrified hemoglobin sample could be visualized at a series of doses up to 5500 MGy, by which dose the sample was sublimed. Comparison of equal-dose series collected with different incident flux densities showed a dose-rate effect favoring lower flux densities. Heat simulations predict that sample heating will only become an issue for very large dose rates (50 e(-)Å(-2) s(-1) or higher) combined with poor thermal contact between the grid and cryo-holder. Secondary radiolytic effects are likely to play a role in dose-rate effects. Stroboscopic data collection combined with

  18. Radiation damage in single-particle cryo-electron microscopy: effects of dose and dose rate

    PubMed Central

    Karuppasamy, Manikandan; Karimi Nejadasl, Fatemeh; Vulovic, Milos; Koster, Abraham J.; Ravelli, Raimond B. G.

    2011-01-01

    Radiation damage is an important resolution limiting factor both in macromolecular X-ray crystallography and cryo-electron microscopy. Systematic studies in macromolecular X-ray crystallography greatly benefited from the use of dose, expressed as energy deposited per mass unit, which is derived from parameters including incident flux, beam energy, beam size, sample composition and sample size. In here, the use of dose is reintroduced for electron microscopy, accounting for the electron energy, incident flux and measured sample thickness and composition. Knowledge of the amount of energy deposited allowed us to compare doses with experimental limits in macromolecular X-ray crystallography, to obtain an upper estimate of radical concentrations that build up in the vitreous sample, and to translate heat-transfer simulations carried out for macromolecular X-ray crystallography to cryo-electron microscopy. Stroboscopic exposure series of 50–250 images were collected for different incident flux densities and integration times from Lumbricus terrestris extracellular hemoglobin. The images within each series were computationally aligned and analyzed with similarity metrics such as Fourier ring correlation, Fourier ring phase residual and figure of merit. Prior to gas bubble formation, the images become linearly brighter with dose, at a rate of approximately 0.1% per 10 MGy. The gradual decomposition of a vitrified hemoglobin sample could be visualized at a series of doses up to 5500 MGy, by which dose the sample was sublimed. Comparison of equal-dose series collected with different incident flux densities showed a dose-rate effect favoring lower flux densities. Heat simulations predict that sample heating will only become an issue for very large dose rates (50 e−Å−2 s−1 or higher) combined with poor thermal contact between the grid and cryo-holder. Secondary radiolytic effects are likely to play a role in dose-rate effects. Stroboscopic data collection

  19. Choosing the optimal dose in sublingual immunotherapy: Rationale for the 300 index of reactivity dose.

    PubMed

    Demoly, Pascal; Passalacqua, Gianni; Calderon, Moises A; Yalaoui, Tarik

    2015-01-01

    Sublingual immunotherapy (SLIT) is an effective and well-tolerated method of treating allergic respiratory diseases associated with seasonal and perennial allergens. In contrast to the subcutaneous route, SLIT requires a much greater amount of antigen to achieve a clinical effect. Many studies have shown that SLIT involves a dose-response relationship, and therefore it is important to use a proven clinically effective dose from the onset of treatment, because low doses are ineffective and very high doses may increase the risk of side effects. A well-defined standardization of allergen content is also crucial to ensure consistent quality, potency and appropriate immunomodulatory action of the SLIT product. Several methods of measuring antigenicity are used by manufacturers of SLIT products, including the index of reactivity (IR), standardized quality tablet unit, and bioequivalent allergy unit. A large body of evidence has established the 300 IR dose of SLIT as offering optimal efficacy and tolerability for allergic rhinitis due to grass and birch pollen and HDM, and HDM-induced moderate, persistent allergic asthma. The 300 IR dose also offers consistency of dosing across a variety of different allergens, and is associated with higher rates of adherence and patient satisfaction. Studies in patients with grass pollen allergies showed that the 300 IR dose has a rapid onset of action, is effective in both adults and children in the short term and, when administered pre-coseasonally in the long term, and maintains the clinical benefit, even after cessation of treatment. In patients with HDM-associated AR and/or asthma, the 300 IR dose also demonstrated significant improvements in symptoms and quality of life, and significantly decreased use of symptomatic medication. The 300 IR dose is well tolerated, with adverse events generally being of mild or moderate severity, declining in frequency and severity over time and in the subsequent courses. We discuss herein the most

  20. Use of dose-dependent absorption into target tissues to more accurately predict cancer risk at low oral doses of hexavalent chromium.

    PubMed

    Haney, J

    2015-02-01

    The mouse dose at the lowest water concentration used in the National Toxicology Program hexavalent chromium (CrVI) drinking water study (NTP, 2008) is about 74,500 times higher than the approximate human dose corresponding to the 35-city geometric mean reported in EWG (2010) and over 1000 times higher than that based on the highest reported tap water concentration. With experimental and environmental doses differing greatly, it is a regulatory challenge to extrapolate high-dose results to environmental doses orders of magnitude lower in a meaningful and toxicologically predictive manner. This seems particularly true for the low-dose extrapolation of results for oral CrVI-induced carcinogenesis since dose-dependent differences in the dose fraction absorbed by mouse target tissues are apparent (Kirman et al., 2012). These data can be used for a straightforward adjustment of the USEPA (2010) draft oral slope factor (SFo) to be more predictive of risk at environmentally-relevant doses. More specifically, the evaluation of observed and modeled differences in the fraction of dose absorbed by target tissues at the point-of-departure for the draft SFo calculation versus lower doses suggests that the draft SFo be divided by a dose-specific adjustment factor of at least an order of magnitude to be less over-predictive of risk at more environmentally-relevant doses. PMID:25445295

  1. Report on Higher Education Technology.

    ERIC Educational Resources Information Center

    New Jersey State Commission on Higher Education.

    Recognizing the rapid development of telecommunications and networking technologies and their growing importance to higher education and New Jersey's overall economic competitiveness, New Jersey's Plan for Higher Education called for the Commission on Higher Education and the Presidents' Council to appoint a Higher Education Technology Task Force…

  2. Women in Virginia Higher Education.

    ERIC Educational Resources Information Center

    New University Conference, Hampton, VA. Peninsula Chapter.

    This document explores how Virginia higher education perpetuates stereotypic social roles, the evolution of sexually segregated schools, the current evidences of sexual discrimination towards faculty, staff and students, the State Council of Higher Education's 1967 plan for higher education, the status of Virginia higher education under the law…

  3. Higher Education and Social Change

    ERIC Educational Resources Information Center

    Brennan, John

    2008-01-01

    An agenda for future higher education research is proposed which incorporates four interconnected elements: changing social contexts; their implications for higher education; mechanisms of interaction between higher education and society; higher education's impact on society. The role of comparative research in investigating these topics is…

  4. Dose of Prophylactic Platelet Transfusions and Prevention of Hemorrhage

    PubMed Central

    Slichter, Sherrill J.; Kaufman, Richard M.; Assmann, Susan F.; McCullough, Jeffrey; Triulzi, Darrell J.; Strauss, Ronald G.; Gernsheimer, Terry B.; Ness, Paul M.; Brecher, Mark E.; Josephson, Cassandra D.; Konkle, Barbara A.; Woodson, Robert D.; Ortel, Thomas L.; Hillyer, Christopher D.; Skerrett, Donna L.; McCrae, Keith R.; Sloan, Steven R.; Uhl, Lynne; George, James N.; Aquino, Victor M.; Manno, Catherine S.; McFarland, Janice G.; Hess, John R.; Leissinger, Cindy; Granger, Suzanne

    2010-01-01

    BACKGROUND We conducted a trial of prophylactic platelet transfusions to evaluate the effect of platelet dose on bleeding in patients with hypoproliferative thrombocytopenia. METHODS We randomly assigned hospitalized patients undergoing hematopoietic stem-cell transplantation or chemotherapy for hematologic cancers or solid tumors to receive prophylactic platelet transfusions at a low dose, a medium dose, or a high dose (1.1×1011, 2.2×1011, or 4.4×1011 platelets per square meter of body-surface area, respectively), when morning platelet counts were 10,000 per cubic millimeter or lower. Clinical signs of bleeding were assessed daily. The primary end point was bleeding of grade 2 or higher (as defined on the basis of World Health Organization criteria). RESULTS In the 1272 patients who received at least one platelet transfusion, the primary end point was observed in 71%, 69%, and 70% of the patients in the low-dose group, the medium-dose group, and the high-dose group, respectively (differences were not significant). The incidences of higher grades of bleeding, and other adverse events, were similar among the three groups. The median number of platelets transfused was significantly lower in the low-dose group (9.25×1011) than in the medium-dose group (11.25×1011) or the high-dose group (19.63×1011) (P = 0.002 for low vs. medium, P<0.001 for high vs. low and high vs. medium), but the median number of platelet transfusions given was significantly higher in the low-dose group (five, vs. three in the medium-dose and three in the high-dose group; P<0.001 for low vs. medium and low vs. high). Bleeding occurred on 25% of the study days on which morning platelet counts were 5000 per cubic millimeter or lower, as compared with 17% of study days on which platelet counts were 6000 to 80,000 per cubic millimeter (P<0.001). CONCLUSIONS Low doses of platelets administered as a prophylactic transfusion led to a decreased number of platelets transfused per patient but an

  5. Retrospective Reconstructions of Active Bone Marrow Dose-Volume Histograms

    SciTech Connect

    Veres, Cristina; Allodji, Rodrigue S.; Llanas, Damien; Vu Bezin, Jérémi; Chavaudra, Jean; Mège, Jean Pierre; Lefkopoulos, Dimitri; Quiniou, Eric; Deutsh, Eric; Vathaire, Florent de; Diallo, Ibrahima

    2014-12-01

    Purpose: To present a method for calculating dose-volume histograms (DVH's) to the active bone marrow (ABM) of patients who had undergone radiation therapy (RT) and subsequently developed leukemia. Methods and Materials: The study focuses on 15 patients treated between 1961 and 1996. Whole-body RT planning computed tomographic (CT) data were not available. We therefore generated representative whole-body CTs similar to patient anatomy. In addition, we developed a method enabling us to obtain information on the density distribution of ABM all over the skeleton. Dose could then be calculated in a series of points distributed all over the skeleton in such a way that their local density reflected age-specific data for ABM distribution. Dose to particular regions and dose-volume histograms of the entire ABM were estimated for all patients. Results: Depending on patient age, the total number of dose calculation points generated ranged from 1,190,970 to 4,108,524. The average dose to ABM ranged from 0.3 to 16.4 Gy. Dose-volume histograms analysis showed that the median doses (D{sub 50%}) ranged from 0.06 to 12.8 Gy. We also evaluated the inhomogeneity of individual patient ABM dose distribution according to clinical situation. It was evident that the coefficient of variation of the dose for the whole ABM ranged from 1.0 to 5.7, which means that the standard deviation could be more than 5 times higher than the mean. Conclusions: For patients with available long-term follow-up data, our method provides reconstruction of dose-volume data comparable to detailed dose calculations, which have become standard in modern CT-based 3-dimensional RT planning. Our strategy of using dose-volume histograms offers new perspectives to retrospective epidemiological studies.

  6. Absorbed dose and dose rate using the Varian OBI 1.3 and 1.4 CBCT system.

    PubMed

    Palm, Asa; Nilsson, Elisabeth; Herrnsdorf, Lars

    2010-01-01

    According to published data, the absorbed dose used for a CBCT image acquisition with Varian OBI v1.3 can be as high as 100 mGy. In 2008 Varian released a new OBI version (v1.4), which promised to reduce the imaging dose. In this study, absorbed doses used for CBCT image acquisitions with the default irradiation techniques of Varian OBI v1.3 and v1.4 are measured. TLDs are used to derive dose distributions at three planes inside an anthropomorphic phantom. In addition, point doses and dose profiles inside a 'stack' of three CTDI body phantoms are measured using a new solid state detector, the CT Dose Profiler. With the CT Dose Profiler, the individual pulses from the X-ray tube are also studied. To verify the absorbed dose measured with the CT Dose Profiler, it is compared to TLD. The image quality is evaluated using a Catphan phantom. For OBI v1.3, doses measured in transverse planes of the Alderson phantom range between 64 mGy and 144 mGy. The average dose is around 100 mGy. For OBI v1.4, doses measured in transverse planes of the Alderson phantom range between 1 mGy and 51 mGy. Mean doses range between 3-35 mGy depending on CBCT mode. CT Dose Profiler data agree with TLD measurements in a CTDI phantom within the uncertainty of the TLD measurements (estimated SD +/- 10%). Instantaneous dose rate at the periphery of the phantom can be higher than 20 mGy/s, which is 10 times the dose rate at the center. The spatial resolution in v1.4 is not as high as in v1.3. In conclusion, measurements show that the imaging doses for default modes in Varian OBI v1.4 CBCT system are significantly lower than in v1.3. The CT Dose Profiler is proven fast and accurate for CBCT applications. PMID:20160695

  7. Comparison of organ dose and dose equivalent for human phantoms of CAM vs. MAX

    NASA Astrophysics Data System (ADS)

    Kim, Myung-Hee Y.; Qualls, Garry D.; Slaba, Tony C.; Cucinotta, Francis A.

    2010-04-01

    For the evaluation of organ dose and dose equivalent of astronauts on space shuttle and the International Space Station (ISS) missions, the CAMERA models of CAM (Computerized Anatomical Male) and CAF (Computerized Anatomical Female) of human tissue shielding have been implemented and used in radiation transport model calculations at NASA. One of new human geometry models to meet the “reference person” of International Commission on Radiological Protection (ICRP) is based on detailed Voxel (volumetric and pixel) phantom models denoted for male and female as MAX (Male Adult voXel) and FAX (Female Adult voXel), respectively. We compared the CAM model predictions of organ doses to those of MAX model, since the MAX model represents the male adult body with much higher fidelity than the CAM model currently used at NASA. Directional body-shielding mass was evaluated for over 1500 target points of MAX for specified organs considered to be sensitive to the induction of stochastic effects. Radiation exposures to solar particle event (SPE), trapped protons, and galactic cosmic ray (GCR) were assessed at the specific sites in the MAX phantom by coupling space radiation transport models with the relevant body-shielding mass. The development of multiple-point body-shielding distributions at each organ made it possible to estimate the mean and variance of organ doses at the specific organ. For the estimate of doses to the blood forming organs (BFOs), data on active marrow distributions in adult were used to weight the bone marrow sites over the human body. The discrete number of target points of MAX organs resulted in a reduced organ dose and dose equivalent compared to the results of CAM organs especially for SPE, and should be further investigated. Differences of effective doses between the two approaches were found to be small (<5%) for GCR.

  8. Integral dose conservation in radiotherapy.

    PubMed

    Reese, Adam S; Das, Shiva K; Curie, Charles; Marks, Lawrence B

    2009-03-01

    Treatment planners frequently modify beam arrangements and use IMRT to improve target dose coverage while satisfying dose constraints on normal tissues. The authors herein analyze the limitations of these strategies and quantitatively assess the extent to which dose can be redistributed within the patient volume. Specifically, the authors hypothesize that (1) the normalized integral dose is constant across concentric shells of normal tissue surrounding the target (normalized to the average integral shell dose), (2) the normalized integral shell dose is constant across plans with different numbers and orientations of beams, and (3) the normalized integral shell dose is constant across plans when reducing the dose to a critical structure. Using the images of seven patients previously irradiated for cancer of brain or prostate cancer and one idealized scenario, competing three-dimensional conformal and IMRT plans were generated using different beam configurations. Within a given plan and for competing plans with a constant mean target dose, the normalized integral doses within concentric "shells" of surrounding normal tissue were quantitatively compared. Within each patient, the normalized integral dose to shells of normal tissue surrounding the target was relatively constant (1). Similarly, for each clinical scenario, the normalized integral dose for a given shell was also relatively constant regardless of the number and orientation of beams (2) or degree of sparing of a critical structure (3). 3D and IMRT planning tools can redistribute, rather than eliminate dose to the surrounding normal tissues (intuitively known by planners). More specifically, dose cannot be moved between shells surrounding the target but only within a shell. This implies that there are limitations in the extent to which a critical structure can be spared based on the location and geometry of the critical structure relative to the target. PMID:19378734

  9. Curtailing patient-specific IMRT QA procedures from 2D dose error distribution.

    PubMed

    Kurosu, Keita; Sumida, Iori; Mizuno, Hirokazu; Otani, Yuki; Oda, Michio; Isohashi, Fumiaki; Seo, Yuji; Suzuki, Osamu; Ogawa, Kazuhiko

    2016-06-01

    A patient-specific quality assurance (QA) test is conducted to verify the accuracy of dose delivery. It generally consists of three verification processes: the absolute point dose difference, the planar dose differences at each gantry angle, and the planar dose differences by 3D composite irradiation. However, this imposes a substantial workload on medical physicists. The objective of this study was to determine whether our novel method that predicts the 3D delivered dose allows certain patient-specific IMRT QAs to be curtailed. The object was IMRT QA for the pelvic region with regard to point dose and composite planar dose differences. We compared measured doses, doses calculated in the treatment planning system, and doses predicted by in-house software. The 3D predicted dose was reconstructed from the per-field measurement by incorporating the relative dose error distribution into the original dose grid of each beam. All point dose differences between the measured and the calculated dose were within ±3%, whereas 93.3% of them between the predicted and the calculated dose were within ±3%. As for planar dose differences, the gamma passing rates between the calculated and the predicted dose were higher than those between the calculated and the measured dose. Comparison and statistical analysis revealed a correlation between the predicted and the measured dose with regard to both point dose and planar dose differences. We concluded that the prediction-based approach is an accurate substitute for the conventional measurement-based approach in IMRT QA for the pelvic region. Our novel approach will help medical physicists save time on IMRT QA. PMID:26661854

  10. Curtailing patient-specific IMRT QA procedures from 2D dose error distribution

    PubMed Central

    Kurosu, Keita; Sumida, Iori; Mizuno, Hirokazu; Otani, Yuki; Oda, Michio; Isohashi, Fumiaki; Seo, Yuji; Suzuki, Osamu; Ogawa, Kazuhiko

    2016-01-01

    A patient-specific quality assurance (QA) test is conducted to verify the accuracy of dose delivery. It generally consists of three verification processes: the absolute point dose difference, the planar dose differences at each gantry angle, and the planar dose differences by 3D composite irradiation. However, this imposes a substantial workload on medical physicists. The objective of this study was to determine whether our novel method that predicts the 3D delivered dose allows certain patient-specific IMRT QAs to be curtailed. The object was IMRT QA for the pelvic region with regard to point dose and composite planar dose differences. We compared measured doses, doses calculated in the treatment planning system, and doses predicted by in-house software. The 3D predicted dose was reconstructed from the per-field measurement by incorporating the relative dose error distribution into the original dose grid of each beam. All point dose differences between the measured and the calculated dose were within ±3%, whereas 93.3% of them between the predicted and the calculated dose were within ±3%. As for planar dose differences, the gamma passing rates between the calculated and the predicted dose were higher than those between the calculated and the measured dose. Comparison and statistical analysis revealed a correlation between the predicted and the measured dose with regard to both point dose and planar dose differences. We concluded that the prediction-based approach is an accurate substitute for the conventional measurement-based approach in IMRT QA for the pelvic region. Our novel approach will help medical physicists save time on IMRT QA. PMID:26661854

  11. Transforming Higher Education: Implications for State Higher Education Finance Policy.

    ERIC Educational Resources Information Center

    Matthews, Dewayne

    1998-01-01

    Examines how information technology is transforming higher education (asynchronous learning, distance education, customized program structure, customized delivery, outcome-based programs, collaboration, and competition) and discusses implications for state higher education finance policy (competition, student costs, collaboration, and…

  12. Standardized radiological dose evaluations

    SciTech Connect

    Peterson, V.L.; Stahlnecker, E.

    1996-05-01

    Following the end of the Cold War, the mission of Rocky Flats Environmental Technology Site changed from production of nuclear weapons to cleanup. Authorization baseis documents for the facilities, primarily the Final Safety Analysis Reports, are being replaced with new ones in which accident scenarios are sorted into coarse bins of consequence and frequency, similar to the approach of DOE-STD-3011-94. Because this binning does not require high precision, a standardized approach for radiological dose evaluations is taken for all the facilities at the site. This is done through a standard calculation ``template`` for use by all safety analysts preparing the new documents. This report describes this template and its use.

  13. [Fixed-dose combination].

    PubMed

    Nagai, Yoshio

    2015-03-01

    Many patients with type 2 diabetes mellitus(T2DM) do not achieve satisfactory glycemic control by monotherapy alone, and often require multiple oral hypoglycemic agents (OHAs). Combining OHAs with complementary mechanisms of action is fundamental to the management of T2DM. Fixed-dose combination therapy(FDC) offers a method of simplifying complex regimens. Efficacy and tolerability appear to be similar between FDC and treatment with individual agents. In addition, FDC can enhance adherence and improved adherence may result in improved glycemic control. Four FDC agents are available in Japan: pioglitazone-glimepiride, pioglitazone-metformin, pioglitazone-alogliptin, and voglibose-mitiglinide. In this review, the advantages and disadvantages of these four combinations are identified and discussed. PMID:25812374

  14. Higher Education and Work. Higher Education Policy Series 23.

    ERIC Educational Resources Information Center

    Brennan, John, Ed.; And Others

    The relationship between higher education and the world of work is examined in terms of the changing structures of higher education institutions and the effect of the relationship on curricula. An international perspective is provided on the changing nature of employment and the labor market; the increasing diversification of higher education…

  15. Patient doses from CT examinations in Turkey

    PubMed Central

    Ataç, Gökçe Kaan; Parmaksız, Aydın; İnal, Tolga; Bulur, Emine; Bulgurlu, Figen; Öncü, Tolga; Gündoğdu, Sadi

    2015-01-01

    PURPOSE We aimed to establish the first diagnostic reference levels (DRLs) for computed tomography (CT) examinations in adult and pediatric patients in Turkey and compare these with international DRLs. METHODS CT performance information and examination parameters (for head, chest, high-resolution CT of the chest [HRCT-chest], abdominal, and pelvic protocols) from 1607 hospitals were collected via a survey. Dose length products and effective doses for standard patient sizes were calculated from the reported volume CT dose index (CTDIvol). RESULTS The median number of protocols reported from the 167 responding hospitals (10% response rate) was 102 across five different age groups. Third quartile CTDIvol values for adult pelvic and all pediatric body protocols were higher than the European Commission standards but were comparable to studies conducted in other countries. CONCLUSION The radiation dose indicators for adult patients were similar to those reported in the literature, except for those associated with head protocols. CT protocol optimization is necessary for adult head and pediatric chest, HRCT-chest, abdominal, and pelvic protocols. The findings from this study are recommended for use as national DRLs in Turkey. PMID:26133189

  16. Retrospective dosimetric comparison of low-dose-rate and pulsed-dose-rate intracavitary brachytherapy using a tandem and mini-ovoids.

    PubMed

    Mourtada, Firas; Gifford, Kent A; Berner, Paula A; Horton, John L; Price, Michael J; Lawyer, Ann A; Eifel, Patricia J

    2007-01-01

    The purpose of this study was to compare the dose distribution of Iridium-192 ((192)Ir) pulsed-dose-rate (PDR) brachytherapy to that of Cesium-137 ((137)Cs) low-dose-rate (LDR) brachytherapy around mini-ovoids and an intrauterine tandem. Ten patient treatment plans were selected from our clinical database, all of which used mini-ovoids and an intrauterine tandem. A commercial treatment planning system using AAPM TG43 formalism was used to calculate the dose in water for both the (137)Cs and (192)Ir sources. For equivalent system loadings, we compared the dose distributions in relevant clinical planes, points A and B, and to the ICRU bladder and rectal reference points. The mean PDR doses to points A and B were 3% +/- 1% and 6% +/- 1% higher than the LDR doses, respectively. For the rectum point, the PDR dose was 4% +/- 3% lower than the LDR dose, mainly because of the (192)Ir PDR source anisotropy. For the bladder point, the PDR dose was 1% +/- 4% higher than the LDR dose. We conclude that the PDR and LDR dose distributions are equivalent for intracavitary brachytherapy with a tandem and mini-ovoids. These findings will aid in the transfer from the current practice of LDR intracavitary brachytherapy to PDR for the treatment of gynecologic cancers. PMID:17707197

  17. Retrospective Dosimetric Comparison of Low-Dose-Rate and Pulsed-Dose-Rate Intracavitary Brachytherapy Using a Tandem and Mini-Ovoids

    SciTech Connect

    Mourtada, Firas Gifford, Kent A.; Berner, Paula A.; Horton, John L.; Price, Michael J.; Lawyer, Ann A.; Eifel, Patricia J.

    2007-10-01

    The purpose of this study was to compare the dose distribution of Iridium-192 ({sup 192}Ir) pulsed-dose-rate (PDR) brachytherapy to that of Cesium-137 ({sup 137}Cs) low-dose-rate (LDR) brachytherapy around mini-ovoids and an intrauterine tandem. Ten patient treatment plans were selected from our clinical database, all of which used mini-ovoids and an intrauterine tandem. A commercial treatment planning system using AAPM TG43 formalism was used to calculate the dose in water for both the {sup 137}Cs and {sup 192}Ir sources. For equivalent system loadings, we compared the dose distributions in relevant clinical planes, points A and B, and to the ICRU bladder and rectal reference points. The mean PDR doses to points A and B were 3% {+-} 1% and 6% {+-} 1% higher than the LDR doses, respectively. For the rectum point, the PDR dose was 4% {+-} 3% lower than the LDR dose, mainly because of the {sup 192}Ir PDR source anisotropy. For the bladder point, the PDR dose was 1% {+-} 4% higher than the LDR dose. We conclude that the PDR and LDR dose distributions are equivalent for intracavitary brachytherapy with a tandem and mini-ovoids. These findings will aid in the transfer from the current practice of LDR intracavitary brachytherapy to PDR for the treatment of gynecologic cancers.

  18. Reflections on Higher Education Research.

    ERIC Educational Resources Information Center

    Keller, George; Moore, Kathryn M.

    1989-01-01

    Two senior scholars assess the first four volumes of "Higher Education: A Handbook of Theory and Research," a series on the nature of higher education as a discipline and the state of research in the field. (Author/MSE)

  19. Acrivastine, terfenadine and diphenhydramine effects on driving performance as a function of dose and time after dosing.

    PubMed

    Ramaekers, J G; O'Hanlon, J F

    1994-01-01

    The study was conducted according to a nine-way, observer- and subject-blind, cross-over design. Its purpose was to compare the single-dose effects of the following drugs on driving performance: acrivastine (8, 16 and 24 mg); the combination of acrivastine (8 mg) with pseudoephedrine (60 mg); terfenadine (60, 120 and 180 mg); diphenhydramine-HCl (50 mg); and placebo. The subjects were 18 healthy female volunteers. Drug effects were assessed in two repetitions of two driving tests (highway driving and car-following) after each treatment. Acrivastine's impairing effects in both driving tests were similarly dose-related. The 8-mg dose had a small, but significant, effect on highway driving in the first trial. The 16-mg and 24-mg doses significantly impaired driving in both tests during the first trial and the 24-mg dose did so again during the second trial. Neither the combination of acrivastine with pseudoephedrine nor terfenadine caused any significant impairment of performance. Diphenhydramine significantly impaired driving in both tests during every trial. In conclusion, the normal therapeutic dose of acrivastine (8 mg) had little effect on driving performance, and virtually none when that dose was given in combination with pseudoephedrine (60 mg). Higher doses of acrivastine severely impaired driving performance. Terfenadine had no significant effect on driving performance after any dose while diphenhydramine strongly impaired every important driving parameter. PMID:7867679

  20. Dose and dose rate effects of whole-body proton-irradiation on lymphocyte blastogenesis and hematological variables: part II

    NASA Technical Reports Server (NTRS)

    Pecaut, Michael J.; Gridley, Daila S.; Smith, Anna L.; Nelson, Gregory A.

    2002-01-01

    The goal of part II of this study was to evaluate functional characteristics of leukocytes and circulating blood cell parameters after whole-body proton irradiation at varying doses and at low- and high-dose-rates (LDR and HDR, respectively). C57BL/6 mice (n=51) were irradiated and euthanized at 4 days post-exposure for assay. Significant radiation dose- (but not dose-rate-) dependent decreases were observed in splenocyte responses to T and B cell mitogens when compared to sham-irradiated controls (P<0.001). Spontaneous blastogenesis, also significantly dose-dependent, was increased in both blood and spleen (P<0.001). Red blood cell counts, hemoglobin concentration, and hematocrit were decreased in a dose-dependent manner (P<0.05), whereas thrombocyte numbers were only slightly affected. Comparison of proton- and gamma-irradiated groups (both receiving 3 Gy at HDR) showed a higher level of spontaneous blastogenesis in blood leukocytes and a lower splenocyte response to concanavalin A following proton irradiation (P<0.05). There were no dose rate effects. Collectively, the data demonstrate that the measurements in blood and spleen were largely dependent upon the total dose of proton radiation and that an 80-fold difference in the dose rate was not a significant factor. A difference, however, was found between protons and gamma-rays in the degree of change induced in some of the measurements.

  1. Relative safety profiles of high dose statin regimens

    PubMed Central

    Escobar, Carlos; Echarri, Rocio; Barrios, Vivencio

    2008-01-01

    Recent clinical trials recommend achieving a low-density lipoprotein cholesterol level of <100 mg/dl in high-risk and <70 mg/dl in very high risk patients. To attain these goals, however, many patients will need statins at high doses. The most frequent side effects related to the use of statins, myopathy, rhabdomyolysis, and increased levels of transaminases, are unusual. Although low and moderate doses show a favourable profile, there is concern about the tolerability of higher doses. During recent years, numerous trials to analyze the efficacy and tolerability of high doses of statins have been published. This paper updates the published data on the safety of statins at high doses. PMID:18827903

  2. Low-dose ticagrelor yields an antiplatelet efficacy similar to that of standard-dose ticagrelor in healthy subjects: an open-label randomized controlled trial

    PubMed Central

    Li, Pan; Gu, Ying; Yang, Yawei; Chen, Lizhi; Liu, Junmei; Gao, Lihong; Qin, Yongwen; Cai, Quancai; Zhao, Xianxian; Wang, Zhuo; Ma, Liping

    2016-01-01

    Ticagrelor has a greater antiplatelet efficacy than clopidogrel but may be accompanied by an increased risk of bleeding. This study evaluated the antiplatelet effect and pharmacokinetic profile of low-dose ticagrelor in healthy Chinese volunteers. Thirty healthy subjects were randomized to receive standard-dose ticagrelor (180-mg loading dose, 90-mg twice daily [bid] [n = 10]), low-dose ticagrelor (90-mg loading dose, 45-mg bid [n = 10]), or clopidogrel (600-mg loading dose, 75-mg once daily [n = 10]). Platelet reactivity was assessed by using the VerifyNow P2Y12 assay at baseline and 0.5, 1, 2, 4, 8, 24, 48, and 72 hours post-dosing. The ticagrelor and AR-C124910XX concentrations were measured for pharmacokinetic analysis. The percentage inhibition of P2Y12 reaction units was higher in the low-dose and standard-dose ticagrelor group than in the clopidogrel group at 0.5, 1, 2, 4, 8, and 48 hours post-dosing (P < 0.05 for all), but did not differ significantly between the two ticagrelor doses at any time-point (P > 0.05). The plasma ticagrelor and ARC124910XX concentrations were approximately 2-fold higher with standard-dose versus low-dose ticagrelor. No serious adverse events were reported. In conclusion, low-dose ticagrelor achieved faster and higher inhibition of platelet functions in healthy Chinese subjects than did clopidogrel, with an antiplatelet efficacy similar to that of standard-dose ticagrelor. PMID:27554803

  3. Occupational radiation doses to operators performing cardiac catheterization procedures.

    PubMed

    Kim, Kwang Pyo; Miller, Donald L; Balter, Stephen; Kleinerman, Ruth A; Linet, Martha S; Kwon, Deukwoo; Simon, Steven L

    2008-03-01

    Cardiac catheterization procedures using fluoroscopy reduce patient morbidity and mortality compared to operative procedures. These diagnostic and therapeutic procedures require radiation exposure to patients and physicians. The objectives of the present investigation were to provide a systematic comprehensive summary of the reported radiation doses received by operators due to diagnostic or interventional fluoroscopically-guided procedures, to identify the primary factors influencing operator radiation dose, and to evaluate whether there have been temporal changes in the radiation doses received by operators performing these procedures. Using PubMed, we identified all English-language journal articles and other published data reporting radiation exposures to operators from diagnostic or interventional fluoroscopically-guided cardiovascular procedures from the early 1970's through the present. We abstracted the reported radiation doses, dose measurement methods, fluoroscopy system used, operational features, radiation protection features, and other relevant data. We calculated effective doses to operators in each study to facilitate comparisons. The effective doses ranged from 0.02-38.0 microSv for DC (diagnostic catheterizations), 0.17-31.2 microSv for PCI (percutaneous coronary interventions), 0.24-9.6 microSv for ablations, and 0.29-17.4 microSv for pacemaker or intracardiac defibrillator implantations. The ratios of doses between various anatomic sites and the thyroid, measured over protective shields, were 0.9 +/- 1.0 for the eye, 1.0 +/- 1.5 for the trunk, and 1.3 +/- 2.0 for the hand. Generally, radiation dose is higher on the left side of an operator's body, because the operator's left side is closer to the primary beam when standing at the patient's right side. Modest operator dose reductions over time were observed for DC and ablation, primarily due to reduction in patient doses due to decreased fluoroscopy/cineradiography time and dose rate by technology

  4. Internationalization of Chinese Higher Education

    ERIC Educational Resources Information Center

    Chen, Linhan; Huang, Danyan

    2013-01-01

    This paper probes into the development of internationalization of higher education in China from ancient times to modern times, including the emergence of international connections in Chinese higher education and the subsequent development of such connections, the further development of internationalization of Chinese higher education, and the…

  5. Higher Education and the Market

    ERIC Educational Resources Information Center

    Brown, Roger

    2008-01-01

    In this paper, the author explores the answers to the following questions: (1) What does the "marketisation" of higher education mean? (2) What are the potential implications for United Kingdom higher education? and (3) How should everyone handle those implications? He also cites the three main reasons why higher education cannot simply be left to…

  6. Higher Education Studies in Japan

    ERIC Educational Resources Information Center

    Kaneko, Motohisa

    2010-01-01

    The rapid development of higher education in the postwar period has given rise to various problems, and higher education studies in Japan have developed in response to them. What have been the major issues, and how did academic research respond to them, in postwar Japan? This article delineates an outline of higher education studies in general,…

  7. Higher Education in the Eighties.

    ERIC Educational Resources Information Center

    McComas, James D.

    Events and conditions over the last 20 years that have altered the course of higher education are briefly noted, and trends in higher education for the early eighties are examined. Among the past influences on higher education that illustrate the wisdom of planning for a realistic period of time, such as five years, are the following: the massive…

  8. History of Higher Education, 1992.

    ERIC Educational Resources Information Center

    History of Higher Education, 1992

    1992-01-01

    This annual compilation offers six articles on the history of higher education. In the first article, "The Historical Matrix of American Higher Education," Roger L. Geiger provides an overview of the history of American higher education. Following it, E. D. Duryea, Jurgen Herbst, and W. Bruce Leslie comment on his hypothesis which identifies eight…

  9. Advancing Diversity in Higher Education

    ERIC Educational Resources Information Center

    Turner, Caroline S.

    2013-01-01

    This special section of the "Journal of Diversity in Higher Education" ("JDHE") on "Advancing Diversity in Higher Education" emerged from the 2012 Association for the Study of Higher Education Council on Ethnic Participation (ASHE-CEP) Pre-Conference Forum. CEP, a standing committee of ASHE, partnered with the…

  10. A Tax for Higher Education

    ERIC Educational Resources Information Center

    Blumenstyk, Goldie

    2012-01-01

    Higher education pays off handsomely for society. Yet on a nationwide basis, states' support for higher education per full-time-equivalent student has fallen to just $6,290, the lowest in 15 years. A dedicated source of funds for higher education is problematic. But what if state and federal lawmakers applied the impeccable logic of the gas tax to…

  11. The Privitization of Higher Education.

    ERIC Educational Resources Information Center

    Tilak, Jandhyala B. G.

    1991-01-01

    Attributes the growth of private education to excess and differentiated demand for higher education. Argues that evidence shows that the higher quality of private education is exaggerated and that private school attendance does not result in higher salaries for graduates. Criticizes private education as not wholly self-financing, elitist, and…

  12. Higher Education and Public Good

    ERIC Educational Resources Information Center

    Marginson, Simon

    2011-01-01

    Policy debate about whether to maintain public subsidies for higher education has stimulated reconsideration of the public mission of higher education institutions, especially those that provide student places conferring private benefits. If the work of higher education institutions is defined simply as the aggregation of private interests, this…

  13. Economic Trends and Higher Education.

    ERIC Educational Resources Information Center

    Ottinger, Cecilia A.

    1992-01-01

    This research brief highlights current and projected economic trends that affect higher education and discusses some of their implications. The brief is organized into three sections: (1) national economic conditions affecting higher education, which presents data on gross national product, inflation, the Higher Education Price Index, the federal…

  14. Dose equivalent neutron dosimeter

    DOEpatents

    Griffith, Richard V.; Hankins, Dale E.; Tomasino, Luigi; Gomaa, Mohamed A. M.

    1983-01-01

    A neutron dosimeter is disclosed which provides a single measurements indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer containing conversion material such as .sup.6 Li and .sup.10 B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet. The density of conversion material in the radiator layer is of an amount which is chosen so that the density of tracks produced in the detecting sheet is proportional to the biological damage done by neutrons, regardless of whether the tracks are produced as the result of moderate energy neutrons striking the radiator layer or as the result of higher energy neutrons striking the sheet of track etch material.

  15. Dose refinement. ARAC's role

    SciTech Connect

    Ellis, J. S.; Sullivan, T. J.; Baskett, R. L.

    1998-06-01

    The Atmospheric Release Advisory Capability (ARAC), located at the Lawrence Livermore National Laboratory, since the late 1970's has been involved in assessing consequences from nuclear and other hazardous material releases into the atmosphere. ARAC's primary role has been emergency response. However, after the emergency phase, there is still a significant role for dispersion modeling. This work usually involves refining the source term and, hence, the dose to the populations affected as additional information becomes available in the form of source term estimates release rates, mix of material, and release geometry and any measurements from passage of the plume and deposition on the ground. Many of the ARAC responses have been documented elsewhere. 1 Some of the more notable radiological releases that ARAC has participated in the post-emergency phase have been the 1979 Three Mile Island nuclear power plant (NPP) accident outside Harrisburg, PA, the 1986 Chernobyl NPP accident in the Ukraine, and the 1996 Japan Tokai nuclear processing plant explosion. ARAC has also done post-emergency phase analyses for the 1978 Russian satellite COSMOS 954 reentry and subsequent partial burn up of its on board nuclear reactor depositing radioactive materials on the ground in Canada, the 1986 uranium hexafluoride spill in Gore, OK, the 1993 Russian Tomsk-7 nuclear waste tank explosion, and lesser releases of mostly tritium. In addition, ARAC has performed a key role in the contingency planning for possible accidental releases during the launch of spacecraft with radioisotope thermoelectric generators (RTGs) on board (i.e. Galileo, Ulysses, Mars-Pathfinder, and Cassini), and routinely exercises with the Federal Radiological Monitoring and Assessment Center (FRMAC) in preparation for offsite consequences of radiological releases from NPPs and nuclear weapon accidents or incidents. Several accident post-emergency phase assessments are discussed in this paper in order to illustrate

  16. Biological Dose Response to PM2.5: Effect of Particle Extraction Method on Platelet and Lung Responses

    PubMed Central

    Van Winkle, Laura S.; Bein, Keith; Anderson, Donald; Pinkerton, Kent E.; Tablin, Fern; Wilson, Dennis; Wexler, Anthony S.

    2015-01-01

    Particulate matter (PM) exposure contributes to respiratory diseases and cardiopulmonary mortality. PM toxicity is related to sources and composition, such as abundance of polycyclic aromatic hydrocarbons (PAHs). We exposed adult male BALB/c mice, via oropharyngeal aspiration, to a range of doses of PM2.5 collected during the winter in downtown Sacramento near a major freeway interchange (SacPM). Two preparation methods (spin-down and multi-solvent extraction) were tested to remove particles from collection filters. Three doses were analyzed 24 h after treatment for (1) leukocytes and total protein in bronchoalveolar lavage fluid (BALF), (2) airway-specific and whole lobe expression of PAH-sensitive genes (CYP1B1 and CYP1A1) and IL-1 b, (3) lung histology, and (4) platelet function. Both extraction methods stimulated biological responses, but the spin-down method was more robust at producing IL-1 b and CYP1B1 gene responses and the multi-solvent extraction induced whole lung CYP1A1. Neutrophils in the BALF were increased 5- to 10-fold at the mid and high dose for both preparations. Histopathology scores indicated dose-dependent responses and increased pathology associated with spin-down-derived PM exposure. In microdissected airways, spin-down PM increased CYP1B1 gene expression significantly, but multi-solvent extracted PM did not. Platelet responses to the physiological agonist thrombin were approximately twice as potent in the spin-down preparation as in the multi-solvent extract. We conclude (1) the method of filter extraction can influence the degree of biological response, (2) for SacPM the minimal effective dose is 27.5–50 µg based on neutrophil recruitment, and (3) P450s are upregulated differently in airways and lung parenchyma in response to PAH-containing PM. PMID:25389146

  17. Biological dose response to PM2.5: effect of particle extraction method on platelet and lung responses.

    PubMed

    Van Winkle, Laura S; Bein, Keith; Anderson, Donald; Pinkerton, Kent E; Tablin, Fern; Wilson, Dennis; Wexler, Anthony S

    2015-02-01

    Particulate matter (PM) exposure contributes to respiratory diseases and cardiopulmonary mortality. PM toxicity is related to sources and composition, such as abundance of polycyclic aromatic hydrocarbons (PAHs). We exposed adult male BALB/c mice, via oropharyngeal aspiration, to a range of doses of PM2.5 collected during the winter in downtown Sacramento near a major freeway interchange (SacPM). Two preparation methods (spin-down and multi-solvent extraction) were tested to remove particles from collection filters. Three doses were analyzed 24 h after treatment for (1) leukocytes and total protein in bronchoalveolar lavage fluid (BALF), (2) airway-specific and whole lobe expression of PAH-sensitive genes (CYP1B1 and CYP1A1) and IL-1 b, (3) lung histology, and (4) platelet function. Both extraction methods stimulated biological responses, but the spin-down method was more robust at producing IL-1 b and CYP1B1 gene responses and the multi-solvent extraction induced whole lung CYP1A1. Neutrophils in the BALF were increased 5- to 10-fold at the mid and high dose for both preparations. Histopathology scores indicated dose-dependent responses and increased pathology associated with spin-down-derived PM exposure. In microdissected airways, spin-down PM increased CYP1B1 gene expression significantly, but multi-solvent extracted PM did not. Platelet responses to the physiological agonist thrombin were approximately twice as potent in the spin-down preparation as in the multi-solvent extract. We conclude (1) the method of filter extraction can influence the degree of biological response, (2) for SacPM the minimal effective dose is 27.5-50 µg based on neutrophil recruitment, and (3) P450s are upregulated differently in airways and lung parenchyma in response to PAH-containing PM. PMID:25389146

  18. Culmination of Low-Dose Pesticide Effects

    PubMed Central

    2013-01-01

    Pesticides applied in agriculture can affect the structure and function of nontarget populations at lower doses and for longer timespans than predicted by the current risk assessment frameworks. We identified a mechanism for this observation. The populations of an aquatic invertebrate (Culex pipiens) exposed over several generations to repeated pulses of low concentrations of the neonicotinoid insecticide (thiacloprid) continuously declined and did not recover in the presence of a less sensitive competing species (Daphnia magna). By contrast, in the absence of a competitor, insecticide effects on the more sensitive species were only observed at concentrations 1 order of magnitude higher, and the species recovered more rapidly after a contamination event. The underlying processes are experimentally identified and reconstructed using a simulation model. We conclude that repeated toxicant pulse of populations that are challenged with interspecific competition may result in a multigenerational culmination of low-dose effects. PMID:23859631

  19. Dose rate effects on the thermoluminescence properties of MWCVD diamond films

    NASA Astrophysics Data System (ADS)

    Gastélum, S.; Cruz-Zaragoza, E.; Meléndrez, R.; Chernov, V.; Barboza-Flores, M.

    Synthetic CVD diamond, being non-toxic and tissue equivalent, has been proposed as a ionizing radiation passive dosimeter with relevant applications in radiotherapy and clinical dosimetry. In the present work, the thermoluminescence (TL) properties of microwave-assisted chemical vapor deposition (MWCVD) diamond, 6 μm thick film grown on (100) silicon substrates, were studied after room temperature γ-irradiation for 2.4, 3.1, 5.94, 13.1, 20.67, 43.4 and 81.11 Gy min-1 dose rates in the range of 0.05-10 kGy. At fixed irradiation dose the TL efficiency increases as the dose rate increases. As the dose increases the peak temperature at the maximum intensity of the TL glow curve is shifted about 10 K degrees toward the lower temperature side. The TL glow curve shape resembles first-order kinetics for low-radiation doses and second-order kinetics for higher doses. Linear dose behavior was found for doses below 200 Gy and supralinear for higher doses; respectively, with a significant dependence on the dose rate, reaching saturation for higher doses around 2.0 kGy. Due to the dose rate dependence of the TL properties of the CVD diamond sample, it is necessary to take these effects into consideration for dosimetric applications involving synthetic CVD diamond.

  20. Mutations induced in Tradescantia by small doses of X-rays and neutrons - Analysis of dose-response curves.

    NASA Technical Reports Server (NTRS)

    Sparrow, A. H.; Underbrink, A. G.; Rossi, H. H.

    1972-01-01

    Dose-response curves for pink somatic mutations in Tradescantia stamen hairs were analyzed after neutron and X-ray irradiation with doses ranging from a fraction of a rad to the region of saturation. The dose-effect relation for neutrons indicates a linear dependence from 0.01 to 8 rads; between 0.25 and 5 rads, a linear dependence is indicated for X-rays also. As a consequence the relative biological effectiveness reaches a constant value (about 50) at low doses. The observations are in good agreement with the predictions of the theory of dual radiation action and support its interpretation of the effects of radiation on higher organisms. The doubling dose of X-rays was found to be nearly 1 rad.

  1. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-06-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  2. Psychotropic dose equivalence in Japan.

    PubMed

    Inada, Toshiya; Inagaki, Ataru

    2015-08-01

    Psychotropic dose equivalence is an important concept when estimating the approximate psychotropic doses patients receive, and deciding on the approximate titration dose when switching from one psychotropic agent to another. It is also useful from a research viewpoint when defining and extracting specific subgroups of subjects. Unification of various agents into a single standard agent facilitates easier analytical comparisons. On the basis of differences in psychopharmacological prescription features, those of available psychotropic agents and their approved doses, and racial differences between Japan and other countries, psychotropic dose equivalency tables designed specifically for Japanese patients have been widely used in Japan since 1998. Here we introduce dose equivalency tables for: (i) antipsychotics; (ii) antiparkinsonian agents; (iii) antidepressants; and (iv) anxiolytics, sedatives and hypnotics available in Japan. Equivalent doses for the therapeutic effects of individual psychotropic compounds were determined principally on the basis of randomized controlled trials conducted in Japan and consensus among dose equivalency tables reported previously by psychopharmacological experts. As these tables are intended to merely suggest approximate standard values, physicians should use them with discretion. Updated information of psychotropic dose equivalence in Japan is available at http://www.jsprs.org/en/equivalence.tables/. [Correction added on 8 July 2015, after first online publication: A link to the updated information has been added.]. PMID:25601291

  3. Characterization of infectious dose and lethal dose of two strains of infectious hematopoietic necrosis virus (IHNV).

    PubMed

    McKenney, Douglas G; Kurath, Gael; Wargo, Andrew R

    2016-03-01

    The ability to infect a host is a key trait of a virus, and differences in infectivity could put one virus at an evolutionary advantage over another. In this study we have quantified the infectivity of two strains of infectious hematopoietic necrosis virus (IHNV) that are known to differ in fitness and virulence. By exposing juvenile rainbow trout (Oncorhynchus mykiss) hosts to a wide range of virus doses, we were able to calculate the infectious dose in terms of ID50 values for the two genotypes. Lethal dose experiments were also conducted to confirm the virulence difference between the two virus genotypes, using a range of virus doses and holding fish either in isolation or in batch so as to calculate LD50 values. We found that infectivity is positively correlated with virulence, with the more virulent genotype having higher infectivity. Additionally, infectivity increases more steeply over a short range of doses compared to virulence, which has a shallower increase. We also examined the data using models of virion interaction and found no evidence to suggest that virions have either an antagonistic or a synergistic effect on each other, supporting the independent action hypothesis in the process of IHNV infection of rainbow trout. PMID:26752429

  4. Characterization of infectious dose and lethal dose of two strains of infectious hematopoietic necrosis virus (IHNV)

    USGS Publications Warehouse

    McKenney, Douglas; Kurath, Gael; Wargo, Andrew

    2016-01-01

    The ability to infect a host is a key trait of a virus, and differences in infectivity could put one virus at an evolutionary advantage over another. In this study we have quantified the infectivity of two strains of infectious hematopoietic necrosis virus (IHNV) that are known to differ in fitness and virulence. By exposing juvenile rainbow trout (Oncorhynchus mykiss) hosts to a wide range of virus doses, we were able to calculate the infectious dose in terms of ID50 values for the two genotypes. Lethal dose experiments were also conducted to confirm the virulence difference between the two virus genotypes, using a range of virus doses and holding fish either in isolation or in batch so as to calculate LD50values. We found that infectivity is positively correlated with virulence, with the more virulent genotype having higher infectivity. Additionally, infectivity increases more steeply over a short range of doses compared to virulence, which has a shallower increase. We also examined the data using models of virion interaction and found no evidence to suggest that virions have either an antagonistic or a synergistic effect on each other, supporting the independent action hypothesis in the process of IHNV infection of rainbow trout.

  5. Dose rate, dose-equivalent rate, and quality factor in SLS-1

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Braby, L. A.; Cucinotta, F. A.; Atwell, W.

    1992-01-01

    A tissue-equivalent proportional counter (TEPC) sensitive to the lineal energy range of 0.26-300 keV micrometer-1 was flown on STS-40 (39 degrees x 278 km x 296 km) inside the Spacelab. This instrument was previously flown on STS-31 but was modified to provide a finer resolution at lower lineal energies to better map the South Atlantic Anomaly (SAA) protons. The instrument was turned on 6 June 1991, and operated for 7470 min (124.5 h). The flight duration was characterized by a very large number of X-ray solar flares and enhanced magnetic field fluctuations; however, no significant dose from the solar particles was measured at the location of this instrument. The flight data can be separated into trapped and galactic cosmic radiation parts. The dose rate, dose-equivalent rate and quality factor for trapped radiation were 4.21 +/- 0.03 mrad day-1, 7.72 +/- 0.05 mrem day-1, and 1.83 +/- 0.1, respectively. The dose rate, dose-equivalent rate, and quality factor for galactic cosmic radiation were 5.34 +/- 0.03 mrad day-1, 14.63 +/- 0.06 mrem day-1, and 2.74 +/- 0.1, respectively. The overall quality factor for the flight was 2.38. The dose from the GCR is higher than from SAA protons because of the high inclination and low altitude of this flight. The AP8MAX model of the trapped radiation gives a dose rate of 2.43 mrad day-1 and a quality factor of 1.77. The CREME solar maximum model of galactic cosmic radiation gives a dose rate of 2.54 mrad day-1 and a quality factor of 2.91. Thus the AP8MAX model underestimates the dose by a factor of 1.8 whereas the CREME model leads to an underestimation of the dose by a factor of 2. A comparison of the LET spectra using the AP8MAX model and galactic cosmic radiation transport codes shows only a qualitative agreement.

  6. A dose error evaluation study for 4D dose calculations

    NASA Astrophysics Data System (ADS)

    Milz, Stefan; Wilkens, Jan J.; Ullrich, Wolfgang

    2014-10-01

    Previous studies have shown that respiration induced motion is not negligible for Stereotactic Body Radiation Therapy. The intrafractional breathing induced motion influences the delivered dose distribution on the underlying patient geometry such as the lung or the abdomen. If a static geometry is used, a planning process for these indications does not represent the entire dynamic process. The quality of a full 4D dose calculation approach depends on the dose coordinate transformation process between deformable geometries. This article provides an evaluation study that introduces an advanced method to verify the quality of numerical dose transformation generated by four different algorithms. The used transformation metric value is based on the deviation of the dose mass histogram (DMH) and the mean dose throughout dose transformation. The study compares the results of four algorithms. In general, two elementary approaches are used: dose mapping and energy transformation. Dose interpolation (DIM) and an advanced concept, so called divergent dose mapping model (dDMM), are used for dose mapping. The algorithms are compared to the basic energy transformation model (bETM) and the energy mass congruent mapping (EMCM). For evaluation 900 small sample regions of interest (ROI) are generated inside an exemplary lung geometry (4DCT). A homogeneous fluence distribution is assumed for dose calculation inside the ROIs. The dose transformations are performed with the four different algorithms. The study investigates the DMH-metric and the mean dose metric for different scenarios (voxel sizes: 8 mm, 4 mm, 2 mm, 1 mm 9 different breathing phases). dDMM achieves the best transformation accuracy in all measured test cases with 3-5% lower errors than the other models. The results of dDMM are reasonable and most efficient in this study, although the model is simple and easy to implement. The EMCM model also achieved suitable results, but the approach requires a more complex

  7. Evaluation of enzyme dose and dose-frequency in ameliorating substrate accumulation in MPS IIIA Huntaway dog brain.

    PubMed

    King, Barbara; Marshall, Neil; Beard, Helen; Hassiotis, Sofia; Trim, Paul J; Snel, Marten F; Rozaklis, Tina; Jolly, Robert D; Hopwood, John J; Hemsley, Kim M

    2015-03-01

    Intracerebrospinal fluid (CSF) infusion of replacement enzyme is under evaluation for amelioration of disease-related symptoms and biomarker changes in patients with the lysosomal storage disorder mucopolysaccharidosis type IIIA (MPS IIIA; www.clinicaltrials.gov ; NCT#01155778; #01299727). Determining the optimal dose/dose-frequency is important, given the invasive method for chronically supplying recombinant protein to the brain, the main site of symptom generation. To examine these variables, we utilised MPS IIIA Huntaway dogs, providing recombinant human sulphamidase (rhSGSH) to young pre-symptomatic dogs from an age when MPS IIIA dog brain exhibits significant accumulation of primary (heparan sulphate) and secondary (glycolipid) substrates. Enzyme was infused into CSF via the cisterna magna at one of two doses (3 mg or 15 mg/infusion), with the higher dose supplied at two different intervals; fortnightly or monthly. Euthanasia was carried out 24 h after the final injection. Dose- and frequency-dependent reductions in heparan sulphate were observed in CSF and deeper layers of cerebral cortex. When we examined the amount of immunostaining of the general endo/lysosomal marker, LIMP-2, or quantified activated microglia, the higher fortnightly dose resulted in superior outcomes in affected dogs. Secondary lesions such as accumulation of GM3 ganglioside and development of GAD-reactive axonal spheroids were treated to a similar degree by both rhSGSH doses and dose frequencies. Our findings indicate that the lower fortnightly dose is sub-optimal for ameliorating existing and preventing further development of disease-related pathology in young MPS IIIA dog brain; however, increasing the dose fivefold but halving the frequency of administration enabled near normalisation of disease-related biomarkers. PMID:25421091

  8. Higher: Setting a Higher Bar for Higher Ed. 2013 Annual Report

    ERIC Educational Resources Information Center

    American Council of Trustees and Alumni, 2014

    2014-01-01

    The American Council of Trustees and Alumni (ACTA) is leading the charge to return "higher" to higher education. We are challenging the status quo to restore academic freedom, academic rigor, and real accountability to higher education. And, we are doing so with an ever-widening network of supporters and partners.

  9. Helical tomotherapy superficial dose measurements

    SciTech Connect

    Ramsey, Chester R.; Seibert, Rebecca M.; Robison, Benjamin; Mitchell, Martha

    2007-08-15

    Helical tomotherapy is a treatment technique that is delivered from a 6 MV fan beam that traces a helical path while the couch moves linearly into the bore. In order to increase the treatment delivery dose rate, helical tomotherapy systems do not have a flattening filter. As such, the dose distributions near the surface of the patient may be considerably different from other forms of intensity-modulated delivery. The purpose of this study was to measure the dose distributions near the surface for helical tomotherapy plans with a varying separation between the target volume and the surface of an anthropomorphic phantom. A hypothetical planning target volume (PTV) was defined on an anthropomorphic head phantom to simulate a 2.0 Gy per fraction IMRT parotid-sparing head and neck treatment of the upper neck nodes. A total of six target volumes were created with 0, 1, 2, 3, 4, and 5 mm of separation between the surface of the phantom and the outer edge of the PTV. Superficial doses were measured for each of the treatment deliveries using film placed in the head phantom and thermoluminescent dosimeters (TLDs) placed on the phantom's surface underneath an immobilization mask. In the 0 mm test case where the PTV extends to the phantom surface, the mean TLD dose was 1.73{+-}0.10 Gy (or 86.6{+-}5.1% of the prescribed dose). The measured superficial dose decreases to 1.23{+-}0.10 Gy (61.5{+-}5.1% of the prescribed dose) for a PTV-surface separation of 5 mm. The doses measured by the TLDs indicated that the tomotherapy treatment planning system overestimates superficial doses by 8.9{+-}3.2%. The radiographic film dose for the 0 mm test case was 1.73{+-}0.07 Gy, as compared to the calculated dose of 1.78{+-}0.05 Gy. Given the results of the TLD and film measurements, the superficial calculated doses are overestimated between 3% and 13%. Without the use of bolus, tumor volumes that extend to the surface may be underdosed. As such, it is recommended that bolus be added for these

  10. On determining dose rate constants spectroscopically

    SciTech Connect

    Rodriguez, M.; Rogers, D. W. O.

    2013-01-15

    Purpose: To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of {sup 125}I and {sup 103}Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089-6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated {sup 125}I and {sup 103}Pd sources. Methods: Spectra generated by 14 {sup 125}I and 6 {sup 103}Pd seeds were calculated in vacuo at 10 cm from the source in a 2.7 Multiplication-Sign 2.7 Multiplication-Sign 0.05 cm{sup 3} voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the {sup 125}I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for {sup 103}Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were Less-Than-Or-Slanted-Equal-To 0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. Results: The ratio of the intensity of the 31 keV line relative to that of the main peak in {sup 125}I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The {sup 103}Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when

  11. Peripheral Doses from Noncoplanar IMRT for Pediatric Radiation Therapy

    SciTech Connect

    Kan, Monica W.K.; Leung, Lucullus H.T.; Kwong, Dora L.W.; Wong, Wicger; Lam, Nelson

    2010-01-01

    The use of noncoplanar intensity-modulated radiation therapy (IMRT) might result in better sparing of some critical organs because of a higher degree of freedom in beam angle optimization. However, this can lead to a potential increase in peripheral dose compared with coplanar IMRT. The peripheral dose from noncoplanar IMRT has not been previously quantified. This study examines the peripheral dose from noncoplanar IMRT compared with coplanar IMRT for pediatric radiation therapy. Five cases with different pediatric malignancies in head and neck were planned with both coplanar and noncoplanar IMRT techniques. The plans were performed such that the tumor coverage, conformality, and dose uniformity were comparable for both techniques. To measure the peripheral doses of the 2 techniques, thermoluminescent dosimeters (TLD) were placed in 10 different organs of a 5-year-old pediatric anthropomorphic phantom. With the use of noncoplanar beams, the peripheral doses to the spinal cord, bone marrow, lung, and breast were found to be 1.8-2.5 times of those using the coplanar technique. This is mainly because of the additional internal scatter dose from the noncoplanar beams. Although the use of noncoplanar technique can result in better sparing of certain organs such as the optic nerves, lens, or inner ears depending on how the beam angles were optimized on each patient, oncologists should be alert of the possibility of significantly increasing the peripheral doses to certain radiation-sensitive organs such as bone marrow and breast. This might increase the secondary cancer risk to patients at young age.

  12. Effective dose from direct and indirect digital panoramic units

    PubMed Central

    Lee, Gun-Sun; Kim, Jin-Soo; Seo, Yo-Seob

    2013-01-01

    Purpose This study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters. Materials and Methods Dose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 kg female). Lithium fluoride thermoluminescent dosimeter (TLD) chips were used for the dosimeter. Two direct and 2 indirect digital panoramic units were evaluated in this study. Effective doses were derived using 2007 International Commission on Radiological Protection (ICRP) recommendations. Results The effective doses of the 4 digital panoramic units ranged between 8.9 µSv and 37.8 µSv. By using the head phantom, the effective doses from the direct digital panoramic units (37.8 µSv, 27.6 µSv) were higher than those from the indirect units (8.9 µSv, 15.9 µSv). The same panoramic unit showed the difference in effective doses according to the gender of the phantom, numbers and locations of TLDs, and kVp. Conclusion To reasonably assess the radiation risk from various dental radiographic units, the effective doses should be obtained with the same numbers and locations of TLDs, and with standard hospital exposure. After that, it is necessary to survey the effective doses from various dental radiographic units according to the gender with the corresponding phantom. PMID:23807930

  13. Are there dangers in biologic dose reduction strategies?

    PubMed

    Chan, Christopher K Y; Holroyd, Christopher R; Mason, Alice; Zarroug, Jalaa; Edwards, Christopher J

    2016-07-01

    Biologic dose reduction strategies, for patients with inflammatory rheumatic diseases, have been assessed in multiple studies to assess outcomes compared to ongoing maintenance dosing. Whilst cessation in established disease usually leads to disease flare, dose tapering approaches for those achieving low disease activity often appear to be successful in the short term. However, tapering can be associated with a higher risk of losing disease control and rates of recapture of disease control using the original biologic dose vary between studies. Over relatively short periods of follow-up, a number of studies have shown no statistical difference in radiographic progression in patients tapering or discontinuing biologics. However, a Cochrane review found that radiographic and functional outcomes may be worse after TNF inhibitor discontinuation, and over long-term disease follow-up flares have been associated with radiographic progression and worse patient reported outcomes. To date, no studies of biological therapy dose reduction have specifically investigated the risk of increased immunogenicity or the effects on cardiovascular risk and other co-morbidities, although these remain important potential risks. In addition, whether there are greater dangers in certain dose reduction approaches such as a reduction in dose at the same frequency or a spacing of doses is not established. PMID:26970488

  14. Alabama Commission on Higher Education. Occasional Papers on Higher Education.

    ERIC Educational Resources Information Center

    Alabama State Commission on Higher Education, Montgomery.

    Two papers on the funding formula of the Alabama Commission for Higher Education are presented. The first paper, by John F. Porter, Jr., "The Origins and Evolutions of the Funding Formula Model Utilized by the Alabama Commission on Higher Education, 1973-82," presents the historical antecedents for the existing formula elements and notes…

  15. Higher Education in the Byelorussian SSR. Monographs on Higher Education.

    ERIC Educational Resources Information Center

    Bondarenko, E. G.; And Others

    Higher education in the Byelorussian Soviet Socialist Republic (BSSR) is described, including the system's history, current conditions, functions, and structure. The particular shape of the Byelorussian higher education is in part due to the fact that it only came into being as a system after the revolution of 1917, meaning that from the beginning…

  16. Compensation in Higher Education. ERIC/Higher Education Research Currents.

    ERIC Educational Resources Information Center

    Trivett, David A.

    Compensation in higher education is an inclusive term, since all the benefits associated with teaching, research, work with people, and work with knowledge might be included. But in terms of purchasing power it appears that compensation for work in higher education has lost ground against inflation. In contrast, wage and salary earners in many…

  17. Higher Education in the USSR. Monographs on Higher Education.

    ERIC Educational Resources Information Center

    Savelyev, A. Y.; And Others

    This monograph describes the system of higher education in the United Soviet Socialist Republics (USSR). The preface points out that despite perestroika, two features of Soviet education persist, a high degree of unity and centralization and a close link between higher education and employers. Chapter 1, "Historical Overview," begins with 4th…

  18. [Epilepsy with higher brain dysfunction].

    PubMed

    Sugimoto, Azusa; Midorikawa, Akira; Koyama, Shinichi; Futamura, Akinori; Kuroda, Takeshi; Fujita, Kazuhisa; Itaya, Kazuhiro; Ishigaki, Seiichiro; Kawamura, Mitsuru

    2013-02-01

    Acquired higher brain dysfunction is for the most part due to cerebral vascular disease, but epilepsy may also be a cause. In this study with five patients, we discuss the advantages of anti-epileptic drugs (AEDs) for persistent higher brain dysfunction. The patients showed chronic amnesia or acute aphasia, with associated symptoms like personality change. All five cases affected automatism or convulsive attack, though only after the emergence of higher brain dysfunction and administration of AEDs. There were underlying diseases like cerebral arteriovenous malformation in four cases, but the other patient had none. Electroencephalogram and single photon emission computed tomography revealed one case of aphasia epilepsy with higher brain dysfunction. These results suggest the potential therapeutic efficacy of AEDs for persistent higher brain dysfunction, and we must differentiate epilepsy with higher brain dysfunction from dementia or cerebral vascular disease. PMID:23399676

  19. Bayesian estimation of dose thresholds

    NASA Technical Reports Server (NTRS)

    Groer, P. G.; Carnes, B. A.

    2003-01-01

    An example is described of Bayesian estimation of radiation absorbed dose thresholds (subsequently simply referred to as dose thresholds) using a specific parametric model applied to a data set on mice exposed to 60Co gamma rays and fission neutrons. A Weibull based relative risk model with a dose threshold parameter was used to analyse, as an example, lung cancer mortality and determine the posterior density for the threshold dose after single exposures to 60Co gamma rays or fission neutrons from the JANUS reactor at Argonne National Laboratory. The data consisted of survival, censoring times and cause of death information for male B6CF1 unexposed and exposed mice. The 60Co gamma whole-body doses for the two exposed groups were 0.86 and 1.37 Gy. The neutron whole-body doses were 0.19 and 0.38 Gy. Marginal posterior densities for the dose thresholds for neutron and gamma radiation were calculated with numerical integration and found to have quite different shapes. The density of the threshold for 60Co is unimodal with a mode at about 0.50 Gy. The threshold density for fission neutrons declines monotonically from a maximum value at zero with increasing doses. The posterior densities for all other parameters were similar for the two radiation types.

  20. Exercise Dose in Clinical Practice.

    PubMed

    Wasfy, Meagan M; Baggish, Aaron L

    2016-06-01

    There is wide variability in the physical activity patterns of the patients in contemporary clinical cardiovascular practice. This review is designed to address the impact of exercise dose on key cardiovascular risk factors and on mortality. We begin by examining the body of literature that supports a dose-response relationship between exercise and cardiovascular disease risk factors, including plasma lipids, hypertension, diabetes mellitus, and obesity. We next explore the relationship between exercise dose and mortality by reviewing the relevant epidemiological literature underlying current physical activity guideline recommendations. We then expand this discussion to critically examine recent data pertaining to the impact of exercise dose at the lowest and highest ends of the spectrum. Finally, we provide a framework for how the key concepts of exercise dose can be integrated into clinical practice. PMID:27267537

  1. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.

    1990-09-01

    This monthly report summarizes the technical progress and project status for the Hanford Environmental Dose Reconstruction (HEDR) Project being conducted at the Pacific Northwest Laboratory (PNL) under the direction of a Technical Steering Panel (TSP). The TSP is composed of experts in numerous technical fields related to this project and represents the interests of the public. The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms, environmental transport, environmental monitoring data, demographics, agriculture, food habits, environmental pathways and dose estimates. 3 figs.

  2. Administrative Effectiveness in Higher Education.

    ERIC Educational Resources Information Center

    Whetten, David A.; Cameron, Kim S.

    1985-01-01

    Determinants of organizational and administrative effectiveness in higher education are discussed, and eight administrator characteristics associated with maintaining and enhancing institutional effectiveness are identified. (MSE)

  3. Impact of peptide transporter 1 on the intestinal absorption and pharmacokinetics of valacyclovir after oral dose escalation in wild-type and PepT1 knockout mice.

    PubMed

    Yang, Bei; Hu, Yongjun; Smith, David E

    2013-10-01

    The primary objective of this study was to determine the in vivo absorption properties of valacyclovir, including the potential for saturable proton-coupled oligopeptide transporter 1 (PepT1)-mediated intestinal uptake, after escalating oral doses of prodrug within the clinical dose range. A secondary aim was to characterize the role of PepT1 on the tissue distribution of its active metabolite, acyclovir. [³H]Valacyclovir was administered to wild-type (WT) and PepT1 knockout (KO) mice by oral gavage at doses of 10, 25, 50, and 100 nmol/g. Serial blood samples were collected over 180 minutes, and tissue distribution studies were performed 20 minutes after a 25-nmol/g oral dose of valacyclovir. We found that the C(max) and area under the curve (AUC)₀₋₁₈₀ of acyclovir were 4- to 6-fold and 2- to 3-fold lower, respectively, in KO mice for all four oral doses of valacyclovir. The time to peak concentration of acyclovir was 3- to 10-fold longer in KO compared with WT mice. There was dose proportionality in the C(max) and AUC₀₋₁₈₀ of acyclovir in WT and KO mice over the valacyclovir oral dose range of 10-100 nmol/g (i.e., linear absorption kinetics). No differences were observed in the peripheral tissue distribution of acyclovir once these tissues were adjusted for differences in perfusing drug concentrations in the systemic circulation. In contrast, some differences were observed between genotypes in the concentrations of acyclovir in the distal intestine. Collectively, the findings demonstrate a critical role of intestinal PepT1 in improving the rate and extent of oral absorption for valacyclovir. Moreover, this study provides definitive evidence for the rational development of a PepT1-targeted prodrug strategy. PMID:23924683

  4. Effective doses from panoramic radiography and CBCT (cone beam CT) using dose area product (DAP) in dentistry

    PubMed Central

    Shin, H S; Nam, K C; Park, H; Choi, H U; Kim, H Y

    2014-01-01

    Objectives: We compared the effective dose from panoramic radiography with that from cone beam CT (CBCT) using dose area product under adult and child exposure conditions. Methods: The effective doses of the cephalo, panorama, implant and dental modes of Alphard 3030 (Asahi Roentgen Ind., Co. Ltd, Kyoto, Japan) CBCT and the Jaw, Wide, Facial and temporomandibular joint modes of Rayscan Symphony (RAY Co., Ltd, Hwaseong, Republic of Korea) CBCT were compared with those of CRANEX® 3+ CEPH (Soredex Orion Corporation, Helsinki, Finland) panoramic radiography equipment under adult and child exposure conditions. Each effective dose was calculated using a conversion formula from dose area product meter measured values (VacuTec Messtechnik GmbH, Dresden, Germany). The conversion formulae used were suggested by Helmrot and Alm Carlsson and Batista et al, and they were applied with the tube voltage taken into consideration. Results: The maximum effective doses from the Alphard 3030 and Rayscan Symphony were 67 and 21 times greater than that from panoramic radiography, respectively. The ratios of the effective dose under the child setting to that under the adult condition were 0.60–0.62 and 0.84–0.95, and the maximum differences in effective doses between the adult and child exposure settings were equivalent to 27 and 4 times greater than a panoramic examination in the Alphard 3030 and Rayscan Symphony, respectively. Conclusions: The effective CBCT doses were higher than those of panoramic radiography. The differences in effective doses between the adult and child CBCT settings were dependent on equipment type and exposure parameters. Therefore, adequate mode selection and control of exposure as well as further research are necessary to minimize the effective dose to patients, especially for radiosensitive children. PMID:24845340

  5. Critical target and dose and dose-rate responses for the induction of chromosomal instability by ionizing radiation

    NASA Technical Reports Server (NTRS)

    Limoli, C. L.; Corcoran, J. J.; Milligan, J. R.; Ward, J. F.; Morgan, W. F.

    1999-01-01

    To investigate the critical target, dose response and dose-rate response for the induction of chromosomal instability by ionizing radiation, bromodeoxyuridine (BrdU)-substituted and unsubstituted GM10115 cells were exposed to a range of doses (0.1-10 Gy) and different dose rates (0.092-17.45 Gy min(-1)). The status of chromosomal stability was determined by fluorescence in situ hybridization approximately 20 generations after irradiation in clonal populations derived from single progenitor cells surviving acute exposure. Overall, nearly 700 individual clones representing over 140,000 metaphases were analyzed. In cells unsubstituted with BrdU, a dose response was found, where the probability of observing delayed chromosomal instability in any given clone was 3% per gray of X rays. For cells substituted with 25-66% BrdU, however, a dose response was observed only at low doses (<1.0 Gy); at higher doses (>1.0 Gy), the incidence of chromosomal instability leveled off. There was an increase in the frequency and complexity of chromosomal instability per unit dose compared to cells unsubstituted with BrdU. The frequency of chromosomal instability appeared to saturate around approximately 30%, an effect which occurred at much lower doses in the presence of BrdU. Changing the gamma-ray dose rate by a factor of 190 (0.092 to 17.45 Gy min(-1)) produced no significant differences in the frequency of chromosomal instability. The enhancement of chromosomal instability promoted by the presence of the BrdU argues that DNA comprises at least one of the critical targets important for the induction of this end point of genomic instability.

  6. Radioactive Dose Assessment and NRC Verification of Licensee Dose Calculation.

    1994-09-16

    Version 00 PCDOSE was developed for the NRC to perform calculations to determine radioactive dose due to the annual averaged offsite release of liquid and gaseous effluent by U.S commercial nuclear power facilities. Using NRC approved dose assessment methodologies, it acts as an inspector's tool for verifying the compliance of the facility's dose assessment software. PCDOSE duplicates the calculations of the GASPAR II mainframe code as well as calculations using the methodologices of Reg. Guidemore » 1.109 Rev. 1 and NUREG-0133 by optional choice.« less

  7. Radioactive Dose Assessment and NRC Verification of Licensee Dose Calculation.

    SciTech Connect

    BOHN, TED S.

    1994-09-16

    Version 00 PCDOSE was developed for the NRC to perform calculations to determine radioactive dose due to the annual averaged offsite release of liquid and gaseous effluent by U.S commercial nuclear power facilities. Using NRC approved dose assessment methodologies, it acts as an inspector's tool for verifying the compliance of the facility's dose assessment software. PCDOSE duplicates the calculations of the GASPAR II mainframe code as well as calculations using the methodologices of Reg. Guide 1.109 Rev. 1 and NUREG-0133 by optional choice.

  8. Management of pediatric radiation dose using GE fluoroscopic equipment.

    PubMed

    Belanger, Barry; Boudry, John

    2006-09-01

    estimate of its dose reduction potential. Finally, two recently developed imaging techniques and their potential effect on dose utilization are discussed. Specifically, we discuss the dose benefits of rotational angiography and low frame rate imaging with advanced image processing in lieu of higher-dose digital subtraction. PMID:16862403

  9. Reagents for astatination of biomolecules. 6. An intact antibody conjugated with a maleimido-closo-decaborate(2-) reagent via sulfhydryl groups had considerably higher kidney concentrations than the same antibody conjugated with an isothiocyanato-closo-decaborate(2-) reagent via lysine amines

    PubMed Central

    Wilbur, D. Scott; Chyan, Ming-Kuan; Nakamae, Hirohisa; Chen, Yun; Hamlin, Donald K.; Santos, Erlinda B.; Kornblit, Brian T.; Sandmaier, Brenda M.

    2012-01-01

    We are investigating the use of an 211At-labeled anti-CD45 monoclonal antibody (mAb) as a replacement of total body irradiation in conditioning regimens designed to decrease the toxicity of hematopoietic cell transplantation (HCT). As part of that investigation, dose-escalation studies were conducted in dogs using 211At-labeled anti-canine CD45 mAb, CA12.10C12, conjugated with a maleimido-closo-decaborate(2-) derivative, 4. Unacceptable renal toxicity was noted in the dogs receiving doses in the 0.27 – 0.62 mCi/kg range. This result was not anticipated, as no toxicity had been noted in prior biodistribution and toxicity studies conducted in mice. Studies were conducted to understand the cause of the renal toxicity and to find a way to circumvent it. A dog biodistribution study was conducted with 123Ilabeled CA12.10C12 that had been conjugated with 4. The biodistribution data showed that 10-fold higher kidney concentrations were obtained with the maleimido-conjugate than had been obtained in a previous biodistribution study with 123I-labeled CA12.10C12 conjugated with an amine-reactive phenylisothiocyanato-CHX-A” derivative. The difference in kidney concentrations observed in dogs for the two conjugation approaches led to an investigation of the reagents. SE-HPLC analyses showed that the purity of the CA12.10C12 conjugated via reduced disulfides was lower than that obtained with amine-reactive conjugation reagents, and non-reducing SDS-PAGE analyses indicated protein fragments were present in the disulfide reduced conjugate. Although we had previously prepared closo-decaborate(2-) derivatives with amine-reactive functional groups (e.g. 6 & 8), a new easily synthesized, amine-reactive (phenylisothiocyanate) derivative, 10, was prepared for use in the current studies. A biodistribution was conducted with co-administered 125I- and 211At-labeled CA12.10C10 conjugated with 10. In that study, lower kidney concentrations were obtained for both radionuclides than had

  10. Reagents for astatination of biomolecules. 6. An intact antibody conjugated with a maleimido-closo-decaborate(2-) reagent via sulfhydryl groups had considerably higher kidney concentrations than the same antibody conjugated with an isothiocyanato-closo-decaborate(2-) reagent via lysine amines.

    PubMed

    Wilbur, D Scott; Chyan, Ming-Kuan; Nakamae, Hirohisa; Chen, Yun; Hamlin, Donald K; Santos, Erlinda B; Kornblit, Brian T; Sandmaier, Brenda M

    2012-03-21

    We are investigating the use of an (211)At-labeled anti-CD45 monoclonal antibody (mAb) as a replacement of total body irradiation in conditioning regimens designed to decrease the toxicity of hematopoietic cell transplantation (HCT). As part of that investigation, dose-escalation studies were conducted in dogs using (211)At-labeled anticanine CD45 mAb, CA12.10C12, conjugated with a maleimido-closo-decaborate(2-) derivative, 4. Unacceptable renal toxicity was noted in the dogs receiving doses in the 0.27-0.62 mCi/kg range. This result was not anticipated, as no toxicity had been noted in prior biodistribution and toxicity studies conducted in mice. Studies were conducted to understand the cause of the renal toxicity and to find a way to circumvent it. A dog biodistribution study was conducted with (123)I-labeled CA12.10C12 that had been conjugated with 4. The biodistribution data showed that 10-fold higher kidney concentrations were obtained with the maleimido-conjugate than had been obtained in a previous biodistribution study with (123)I-labeled CA12.10C12 conjugated with an amine-reactive phenylisothiocyanato-CHX-A″ derivative. The difference in kidney concentrations observed in dogs for the two conjugation approaches led to an investigation of the reagents. SE-HPLC analyses showed that the purity of the CA12.10C12 conjugated via reduced disulfides was lower than that obtained with amine-reactive conjugation reagents, and nonreducing SDS-PAGE analyses indicated protein fragments were present in the disulfide reduced conjugate. Although we had previously prepared closo-decaborate(2-) derivatives with amine-reactive functional groups (e.g., 6 and 8), a new, easily synthesized, amine-reactive (phenylisothiocyanate) derivative, 10, was prepared for use in the current studies. A biodistribution was conducted with coadministered (125)I- and (211)At-labeled CA12.10C10 conjugated with 10. In that study, lower kidney concentrations were obtained for both radionuclides

  11. Higher Education, Employability and Competitiveness

    ERIC Educational Resources Information Center

    Pavlin, Samo; Svetlicic, Marjan

    2012-01-01

    This paper studies the relationship between competitiveness and higher education systems in Europe. It explores whether more competitive countries have developed more labour-market-oriented systems of higher education (HE) that thereby give their graduates greater short term employability potential. Based on and a large-scale survey among 45.000…

  12. Higher Education in the USSR.

    ERIC Educational Resources Information Center

    Saveljev, Alexander

    1983-01-01

    The objectives of the Soviet system of higher education and the expansion of the role of higher education are described, emphasizing the development of labor and industry for increased productivity, creativity, and specialization. A trend toward regular continuing education to keep pace with technological advancement is also noted. (MSE)

  13. Women in Higher Education, 1996.

    ERIC Educational Resources Information Center

    Wenniger, Mary Dee, Ed.

    1996-01-01

    This document consists of the issues of a 1996 newsletter on women students, teachers, and administrators in higher education. Each issue includes feature articles, news on higher education, profiles of significant people in the field, and job announcements. The issues' main articles concern: (1) a successful campaign to increase female…

  14. Queering Transformation in Higher Education

    ERIC Educational Resources Information Center

    Msibi, Thabo

    2013-01-01

    Transformation in higher education has tended to focus on race and sex, at the expense of other forms of discrimination. This article addresses the silencing of "queer" issues in higher education. Using queer theory as a framework, and drawing on current literature, popular media reports, two personal critical incidents and a project…

  15. Theorising Quality in Higher Education

    ERIC Educational Resources Information Center

    Morley, Louise

    2004-01-01

    Britain now has the most heavily regulated higher education system in the world and institutions must deliver best educational value. This book explores the political and psychic economy of quality assurance in higher education and interrogates the discourse and practices associated with the audit culture in Britain. Following Acknowledgements and…

  16. History of Higher Education, 1999.

    ERIC Educational Resources Information Center

    Geiger, Roger L., Ed.

    1999-01-01

    The six papers in this annual volume on the history of higher education cover some of the changes that evolved over the years in various U.S. Institutions. The first paper is: "The Articulation of Secondary and Higher Education: Four Historical Models at the University of Georgia" (J. Patrick McCarthy), which discusses the efforts of trustees and…

  17. Higher Education: Open for Business

    ERIC Educational Resources Information Center

    Gilde, Christian, Ed.

    2007-01-01

    This book addresses a problem in higher learning, which is newly recognized in the academic spotlight: the overcommercialization of higher education. The book asks that you, the reader, think about the following: Did you go to a Coke or Pepsi school? Do your children attend a Nike or Adidas school? Is the college in your town a Dell or Gateway…

  18. Higher Education in New York.

    ERIC Educational Resources Information Center

    Lane, Frederick, Ed.

    1983-01-01

    New York State higher education policy and finance are discussed in four articles. In "Higher Education and Public Policy in New York," Frederick S. Lane considers the state's institutions, policymakers and politics, financing of colleges, enrollment patterns, links to economic development, and the changing educational environment. Paul T.…

  19. Women in Higher Education, 1994.

    ERIC Educational Resources Information Center

    Wenninger, Mary Dee, Ed.

    1994-01-01

    This document consists of the 12 monthly issues of a newsletter on women students, teachers, and administrators in higher education, issued in 1994. Each issue includes feature articles, news on higher education, profiles of significant people in the field, and job announcements. The issues' main article topics are: (1) campuses's changing…

  20. Exploring Higher Education Financing Options

    ERIC Educational Resources Information Center

    Nkrumah-Young, Kofi K.; Powell, Philip

    2011-01-01

    Higher education can be financed privately, financed by governments, or shared. Given that the benefits of education accrue to the individual and the state, many governments opt for shared financing. This article examines the underpinnings of different options for financing higher education and develops a model to compare conditions to choices and…

  1. Unexploited Efficiencies in Higher Education

    ERIC Educational Resources Information Center

    Eyring, Henry C.

    2011-01-01

    In "Unexploited Efficiencies in Higher Education," Henry C. Eyring, a junior majoring in Economics at Brigham Young University-Idaho, argues that one way that the U.S. can compete globally in college attainment is to decrease cost-per-graduate. He explains how many stakeholders in higher education stand to benefit from unexploited…

  2. Feminist Research in Higher Education

    ERIC Educational Resources Information Center

    Ropers-Huilman, Rebecca; Winters, Kelly T.

    2011-01-01

    This essay provides an overview of feminist methodology and its potential to enhance the study of higher education. Foregrounding the multiple purposes and research relationships developed through feminist research, the essay urges higher education scholars to engage feminist theories, epistemologies, and methods to inform policy, research, and…

  3. History of Higher Education, 1994.

    ERIC Educational Resources Information Center

    History of Higher Education, 1994

    1994-01-01

    This annual compilation presents four papers which focus on significant developments in higher education in nineteenth-century Europe and the United States. An introduction to the volume by Roger L. Geiger notes commonalities across the four papers and major trends in historical research on institutions of higher education. The first paper, by…

  4. Higher Education, Poverty and Development

    ERIC Educational Resources Information Center

    Tilak, Jandhyala B. G.

    2010-01-01

    There is a presumption among many policy makers that higher education is not necessary for economic growth and development; it is literacy and basic education and at best secondary education that are argued to be important. Estimates of internal rate of return contributed to strengthening of such a presumption. Accordingly, higher education has…

  5. Fact Book on Higher Education

    ERIC Educational Resources Information Center

    Marks, Joseph L.; Diaz, Alicia A.

    2009-01-01

    The "Southern Regional Education Board (SREB) Fact Book on Higher Education" is one of the nation's most comprehensive collections of comparative data on higher education. For decades, state leaders, policy-makers, researchers and journalists have used the "Fact Book" to find useful data quickly--and to learn more about long-term trends and…

  6. Does Higher Education Need Deschooling?

    ERIC Educational Resources Information Center

    Butson, Russell

    2011-01-01

    This paper presents an attempt to overcome the contemporary obsession with "learning" and proposes that current practices in higher education are aligned too closely with the educational theories and practices developed within pre-university compulsory education. The author takes the position that higher education is substantially different from…

  7. The Marketing of Higher Education.

    ERIC Educational Resources Information Center

    Brooker, George; Noble, Michael

    1985-01-01

    Formal college and university marketing programs are challenging to develop and implement because of the complexity of the marketing mix, the perceived inappropriateness of a traditional marketing officer, the number of diverse groups with input, the uniqueness of higher education institutions, and the difficulty in identifying higher education…

  8. Postmodernism in Higher Educational Administration

    ERIC Educational Resources Information Center

    Demaris, Michalyn C.; Kritsonis, William Allan

    2007-01-01

    Postmodernism has many inferences that can be applied to the theory and practice of higher educational administration. Today, in higher education administrators are continuously focused on strategies that will ensure the future of minority educational institutions. As a result postmodernism is an important factor in the future of higher…

  9. History of American Higher Education

    ERIC Educational Resources Information Center

    McCarthy, Margaret Cain

    2011-01-01

    "History of American Higher Education" documents the fascinating evolution of American colleges and universities, touching on the historical events that shaped them, from the colonial era through the early twenty-first century. Throughout history, higher education has played an important role in the transmission of cultural identity from one…

  10. THE ECONOMICS OF HIGHER EDUCATION.

    ERIC Educational Resources Information Center

    CARTTER, ALLAN M.; AND OTHERS

    THIS PUBLICATION CONTAINS PAPERS PRESENTED AT A COLLOQUIUM HELD BY THE COLLEGE SCHOLARSHIP SERVICE IN 1965. THE PAPERS DEAL BROADLY WITH THE QUESTION OF THE MOST EFFECTIVE METHODS OF FINANCING HIGHER EDUCATION, AND WITH THE ROLE AND PROBLEMS OF THE EDUCATIONAL CONSUMER. THE PAPERS DEAL WITH--(1) THE ECONOMICS OF HIGHER EDUCATION, (2) PRICING…

  11. Innovations in Higher Education? Hah!

    ERIC Educational Resources Information Center

    Kirschner, Ann

    2012-01-01

    One can hardly mention higher education today without hearing the word "innovation," or its understudies "change," "reinvention," "transformation." Last summer the National Governors Association opened its meeting with a plenary session on higher education, innovation, and economic growth. But there is nothing funny about the need for innovation…

  12. Strategy Process in Higher Education

    ERIC Educational Resources Information Center

    Kettunen, Juha

    2010-01-01

    Higher education institutions educate those who are the most talented and best able to secure the future for the next generation. This study examines an efficient strategy process in higher education and emphasises the importance of sufficient dialogue during the process. The study describes the strategy process of the Turku University of Applied…

  13. Learning Entrepreneurship in Higher Education

    ERIC Educational Resources Information Center

    Taatila, Vesa P.

    2010-01-01

    Purpose: There is a constant need to produce more entrepreneurial graduates from higher education institutions. This paper aims to present and discuss several successful cases of entrepreneurial learning environments in order to suggest some important aspects that higher education institutions should consider. Design/methodology/approach: The…

  14. The Overselling of Higher Education

    ERIC Educational Resources Information Center

    Leef, George C.

    2006-01-01

    There is not enough substance behind a degree to warrant the ubiquitous belief that a stint in higher education is a "sine qua non" for success in America. While college diplomas may translate into higher-paying jobs for some, high school signifies little in the way of education these days, so jaded employers' estimates of the real value of…

  15. Institutional Change and Higher Education

    ERIC Educational Resources Information Center

    Loomis, Steven; Rodriguez, Jacob

    2009-01-01

    Institutional change includes the supplanting of the old model of production with a new one, the elimination of old markets and the emergence of new ones. As higher education around the world shifts from national markets to an integrated transnational market, and possibly toward a virtual market, Christian higher education, like other market…

  16. The State and Higher Education.

    ERIC Educational Resources Information Center

    Millard, Richard M.

    Although the federal influence on higher education is important, throughout the United States' history the state role in higher education has been a vital and changing one, and not always uniform. In 1976, two-thirds of the institutional revenue coming from government came from the states, making the state issue an important one. One of the most…

  17. Directory of Higher Education, 2001.

    ERIC Educational Resources Information Center

    Illinois State Board of Higher Education, Springfield.

    This directory contains addresses or other contact information for members of the Illinois Board of Higher Education and administrators at Illinois public and private colleges and universities. Mailing addresses are given for members of the state Board of Higher Education and members of the boards of the institutions listed. Telephone numbers are…

  18. Directory of Higher Education, 2000.

    ERIC Educational Resources Information Center

    Illinois State Board of Higher Education, Springfield.

    This directory lists the names, addresses, and telephone numbers of members of higher education organizations in the state of Illinois. Included for the Illinois Board of Higher Education is an organization chart, list of board and staff members, and a list of members of the Illinois Century Network. Board members and administrative officers are…

  19. Effective Communication in Higher Education

    ERIC Educational Resources Information Center

    Howard, Melissa

    2014-01-01

    The intent for this paper is to show that communication within the higher education field is a current problem. By looking first at the different styles, forms, and audiences for communication, the reader will hopefully gain perspective as to why this is such a problem in higher education today. Since the Millennial generation is the newest set of…

  20. Canuck-Do Higher Education.

    ERIC Educational Resources Information Center

    Rosenfeld, Mark

    2003-01-01

    Discusses how, like Australia, Canadian higher education has experienced large-scale cuts in government funding, the deregulation of tuition and general cost shifting to students, inability to accommodate increased student demand, faculty "brain drain" and shortages, and an erosion of public policy toward viewing higher education as a business.…

  1. Higher Education and Social Commitment.

    ERIC Educational Resources Information Center

    Nasution, S.; Virasai, Banphot, Eds.

    The proceedings of the Regional Institute of Higher Education and Development's seminar and the meaning and implications of social commitment in higher education are reported. The welcoming address (S. Nasution) and the opening address (Y. B. Dato' Murad bin Mohd. Noor) welcome the participants and set the tone for the discussions to follow. The…

  2. Strategic Planning for Higher Education.

    ERIC Educational Resources Information Center

    Kotler, Philip; Murphy, Patrick E.

    1981-01-01

    The framework necessary for achieving a strategic planning posture in higher education is outlined. The most important benefit of strategic planning for higher education decision makers is that it forces them to undertake a more market-oriented and systematic approach to long- range planning. (Author/MLW)

  3. The Higher Education Research Archipelago

    ERIC Educational Resources Information Center

    Macfarlane, Bruce

    2012-01-01

    Ever since he stumbled into doing higher education research as a young academic in the 1980s, the author has been trying to understand it as a "field" of study. His career, as a former business lecturer, then an academic developer and now an associate professor for higher education working in an Education Faculty has given him opportunities to see…

  4. A Higher Education Issues Study.

    ERIC Educational Resources Information Center

    Balm, Gerald J.; Blomberg, Robert

    1987-01-01

    As part of a strategic planning effort guiding community socioeconomic development through 2000, the citizens of Rochester, Minnesota, tackled the problem of providing equitable, accessible, and accountable higher education. Studying external factors and developing an internal situation analysis led to a set of higher education issues and…

  5. Disruptive Technologies in Higher Education

    ERIC Educational Resources Information Center

    Flavin, Michael

    2012-01-01

    This paper analyses the role of "disruptive" innovative technologies in higher education. In this country and elsewhere, Higher Education Institutions (HEIs) have invested significant sums in learning technologies, with Virtual Learning Environments (VLEs) being more or less universal, but these technologies have not been universally adopted and…

  6. Higher Education Marketing: A Challenge.

    ERIC Educational Resources Information Center

    Canterbury, Richard

    1999-01-01

    States that similarities between education and other services may not be sufficient to conclude that services marketing methods can be easily transferred to all markets in higher education. Article identifies and discusses why higher education marketing is a particular challenge. Suggests that understanding these challenges can help in making…

  7. Personnel Management in Higher Education.

    ERIC Educational Resources Information Center

    Millett, John D.; And Others

    This document on personnel management in higher education contains three papers that are designed to be used as guidelines for educational administrators. The first two papers, by John D. Millett, discuss the scope and problems of higher education administration and the problems associated with collective bargaining and tenure on college campuses.…

  8. The Cost of Higher Education.

    ERIC Educational Resources Information Center

    Hartle, Terry W.

    1998-01-01

    A discussion of the current cost and financing of higher education looks at how higher education has been treated in federal policy in recent years, its status in public policy in the near future, including some salient uncertainties, and college cost and student debt. Emphasis is given to trends in the cost of professional education. (MSE)

  9. The Economy and Higher Education.

    ERIC Educational Resources Information Center

    Anderson, Richard E.

    1988-01-01

    The macroeconomic trends shaping the United States economy and the effects of those trends on higher education are considered. Warning institutions of higher education about possible problems in the economy will place them in a better position to react if necessary. The economic environment is discussed in terms of productivity (goods and services…

  10. Minority Access to Higher Education

    ERIC Educational Resources Information Center

    Jackson, Nathaniel

    2012-01-01

    Blacks, Hispanics, Native Americans, and Asian Americans are entitled to equal access to all institutions of higher education. Ensuring greater access and participation by minorities in higher education is one of the most practical ways of moving America closer to the ideal of equal opportunity, which is the actualization of the American dream.…

  11. Higher order stationary subspace analysis

    NASA Astrophysics Data System (ADS)

    Panknin, Danny; von Bünau, Paul; Kawanabe, Motoaki; Meinecke, Frank C.; Müller, Klaus-Robert

    2016-03-01

    Non-stationarity in data is an ubiquitous problem in signal processing. The recent stationary subspace analysis procedure (SSA) has enabled to decompose such data into a stationary subspace and a non-stationary part respectively. Algorithmically only weak non- stationarities could be tackled by SSA. The present paper takes the conceptual step generalizing from the use of first and second moments as in SSA to higher order moments, thus defining the proposed higher order stationary subspace analysis procedure (HOSSA). The paper derives the novel procedure and shows simulations. An obvious trade-off between the necessity of estimating higher moments and the accuracy and robustness with which they can be estimated is observed. In an ideal setting of plenty of data where higher moment information is dominating our novel approach can win against standard SSA. However, with limited data, even though higher moments actually dominate the underlying data, still SSA may arrive on par.

  12. Multigroup neutron dose calculations for proton therapy

    SciTech Connect

    Kelsey Iv, Charles T; Prinja, Anil K

    2009-01-01

    We have developed tools for the preparation of coupled multigroup proton/neutron cross section libraries. Our method is to use NJOY to process evaluated nuclear data files for incident particles below 150 MeV and MCNPX to produce data for higher energies. We modified the XSEX3 program of the MCNPX code system to produce Legendre expansions of scattering matrices generated by sampling the physics models that are comparable to the output of the GROUPR routine of NJOY. Our code combines the low and high energy scattering data with user input stopping powers and energy deposition cross sections that we also calculated using MCNPX. Our code also calculates momentum transfer coefficients for the library and optionally applies an energy straggling model to the scattering cross sections and stopping powers. The motivation was initially for deterministic solution of space radiation shielding calculations using Attila, but noting that proton therapy treatment planning may neglect secondary neutron dose assessments because of difficulty and expense, we have also investigated the feasibility of multi group methods for this application. We have shown that multigroup MCNPX solutions for secondary neutron dose compare well with continuous energy solutions and are obtainable with less than half computational cost. This efficiency comparison neglects the cost of preparing the library data, but this becomes negligible when distributed over many multi group calculations. Our deterministic calculations illustrate recognized obstacles that may have to be overcome before discrete ordinates methods can be efficient alternatives for proton therapy neutron dose calculations.

  13. Dose reduction in molecular breast imaging

    NASA Astrophysics Data System (ADS)

    Wagenaar, Douglas J.; Chowdhury, Samir; Hugg, James W.; Moats, Rex A.; Patt, Bradley E.

    2011-10-01

    Molecular Breast Imaging (MBI) is the imaging of radiolabeled drugs, cells, or nanoparticles for breast cancer detection, diagnosis, and treatment. Screening of broad populations of women for breast cancer with mammography has been augmented by the emergence of breast MRI in screening of women at high risk for breast cancer. Screening MBI may benefit the sub-population of women with dense breast tissue that obscures small tumors in mammography. Dedicated breast imaging equipment is necessary to enable detection of early-stage tumors less than 1 cm in size. Recent progress in the development of these instruments is reviewed. Pixellated CZT for single photon MBI imaging of 99mTc-sestamibi gives high detection sensitivity for early-stage tumors. The use of registered collimators in a near-field geometry gives significantly higher detection efficiency - a factor of 3.6-, which translates into an equivalent dose reduction factor given the same acquisition time. The radiation dose in the current MBI procedure has been reduced to the level of a four-view digital mammography study. In addition to screening of selected sub-populations, reduced MBI dose allows for dual-isotope, treatment planning, and repeated therapy assessment studies in the era of molecular medicine guided by quantitative molecular imaging.

  14. Efficacy of a single high dose versus multiple low doses of LLLT on wounded skin fibroblasts

    NASA Astrophysics Data System (ADS)

    Hawkins, Denise H.; Abrahamse, Heidi

    2007-07-01

    Background/purpose: In vivo studies have demonstrated that phototherapy accelerates wound healing in the clinical environment; however the exact mechanism is still not completely understood. The main focus of this study was to use in vitro laboratory results to establish an effective treatment regimen that may be practical and applicable to the clinical environment. This in vitro study aimed to compare the cellular responses of wounded fibroblasts following a single exposure of 5 J/cm2 or multiple exposures of low doses (2.5 J/cm2 or 5 J/cm2) on one day of the week to a single application of a higher dose (16 J/cm2) on day 1 and day 4. Methodology: Cellular responses to Helium-Neon (632.8 nm) laser irradiation were evaluated by measuring changes in cell morphology, cell viability, cell proliferation, membrane integrity and DNA damage. Results: Wounded cells exposed to 5 J/cm2 on day 1 and day 4 showed an increase in cell viability, increase in the release of bFGF, increase in cell density, decrease in ALP enzyme activity and decrease in caspase 3/7 activity indicating a stimulatory effect. Wounded cells exposed to three doses of 5 J/cm2 on day 1 showed a decrease in cell viability and cell proliferation and an increase in LDH cytotoxicity and DNA damage indicating an inhibitory effect. Conclusion: Results indicate that cellular responses are influenced by the combination of dose administered, number of exposures and time between exposures. Single doses administered with sufficient time between exposures is more beneficial to restoring cell function than multiple doses within a short period. Although this work confirms previous reports on the cumulative effect of laser irradiation it provides essential information for the initiation of in vivo clinical studies.

  15. Discussion on the usefulness of dose dynamic multi-leaf collimator-based plan to overcome dose limit of spinal cord in high-dose radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, E. C.; Cho, J. H.; Park, C. S.; Kim, D. H.; Choi, C. W.

    2014-03-01

    In this study, the conventional plan was compared with the plan that was based on a dose dynamic multi-leaf collimator (MLC), and a dose dynamic MLC was used to evaluate its usefulness. Then, this study examined if it was possible to perform a high-dose radiation therapy by adjusting the dose limit of the spinal cord when the dose dynamic MLC-based plan was used. First of all, linear accelerator was used to compare the conventional plan with the dose dynamic MLC-based plan. Then, the study was conducted in two methods in order to examine the proper range of the shield for the spinal cord when the dose dynamic MLC was used to adjust the dose of the spinal cord. In the first method, X-omat film was used to perform film dosimetry. In the second method, radiation treatment planning (RTP) system was used to find out the proper range among 0, 3, 6, and 9 mm. When film scan was performed in the each range, respectively, from the spinal cord and under the same conditions, it was confirmed to be appropriate to use the range of 3 mm. When the RTP system was used to perform planning in the shield range of each range, respectively, from the spinal cord, dose-volume histogram (DVH) was a slight difference could be found in the region from 25% to 35%. On the contrary, no radiation exposure was found in the region of 35% or higher for all of the each range. Consequently, if MLC is selected in consideration of the planning target volume (PTV), the most proper value can be obtained by selecting the range of 3 mm. Next, the DVH was compared to examine the relationship in PTV when the each range was used for planning. All of the ranges showed the same pattern up to the point of 90%. However, the results were different in the region of higher than 90% because the dose was low for the spinal cord, and a relatively useful dose was used for PTV when the range was 3 mm.

  16. Radiation dose estimates for radiopharmaceuticals

    SciTech Connect

    Stabin, M.G.; Stubbs, J.B.; Toohey, R.E.

    1996-04-01

    Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms.

  17. Enhancement of T cell responses as a result of synergy between lower doses of radiation and T cell stimulation.

    PubMed

    Spary, Lisa K; Al-Taei, Saly; Salimu, Josephine; Cook, Alexander D; Ager, Ann; Watson, H Angharad; Clayton, Aled; Staffurth, John; Mason, Malcolm D; Tabi, Zsuzsanna

    2014-04-01

    As a side effect of cancer radiotherapy, immune cells receive varying doses of radiation. Whereas high doses of radiation (>10 Gy) can lead to lymphopenia, lower radiation doses (2-4 Gy) represent a valid treatment option in some hematological cancers, triggering clinically relevant immunological changes. Based on our earlier observations, we hypothesized that lower radiation doses have a direct positive effect on T cells. In this study, we show that 0.6-2.4 Gy radiation enhances proliferation and IFN-γ production of PBMC or purified T cells induced by stimulation via the TCR. Radiation with 1.2 Gy also lowered T cell activation threshold and broadened the Th1 cytokine profile. Although radiation alone did not activate T cells, when followed by TCR stimulation, ERK1/2 and Akt phosphorylation increased above that induced by stimulation alone. These changes were followed by an early increase in glucose uptake. Naive (CD45RA(+)) or memory (CD45RA(-)) T cell responses to stimulation were boosted at similar rates by radiation. Whereas increased Ag-specific cytotoxic activity of a CD8(+) T cell line manifested in a 4-h assay (10-20% increase), highly significant (5- to 10-fold) differences in cytokine production were detected in 6-d Ag-stimulation assays of PBMC, probably as a net outcome of death of nonstimulated and enhanced response of Ag-stimulated T cells. T cells from patients receiving pelvic radiation (2.2-2.75 Gy) also displayed increased cytokine production when stimulated in vitro. We report in this study enhanced T cell function induced by synergistic radiation treatment, with potential physiological significance in a wide range of T cell responses. PMID:24600032

  18. Individual and collective doses from cosmic radiation in Ireland.

    PubMed

    Colgan, P A; Synnott, H; Fenton, D

    2007-01-01

    This paper assesses the individual and collective doses in Ireland due to cosmic radiation. Information on the exposure to cosmic radiation at ground level is reviewed and published data on the frequency of routes flown by Irish residents is used to calculate the dose due to air travel. Occupational exposure of aircrew is also evaluated. Experimental data on cosmic radiation exposure at ground level is in good agreement with international estimates and the average individual dose is calculated as 300 microSv annually. Published data on international air travel by Irish residents shows a 50% increase in the number of flights taken between 2001 and 2005. This increase is primarily on short-haul flights to Europe, but there have been significant percentage increases in all long-haul flights, with the exception of flights to Africa. The additional per capita dose due to air travel is estimated to be 45 muSv, of which 51% is accumulated on European routes and 34% on routes to the United States. Exposure of aircrew to cosmic radiation is now controlled by legislation and all airlines holding an Air Operator's Certificate issued by the Irish Aviation Authority are required to report annually the doses received by their employees in the previous year. There has been a 75% increase in the number of aircrew receiving doses >1 mSv since 2002. In 2004 and 2005 the average individual doses received by Irish aircrew were 1.8 and 2.0, mSv, respectively. The corresponding per caput dose for the entire population is <3 muSv. While this is low compared with the per caput doses from other sources of cosmic radiation, aircrew exposure represents a higher collective dose than any other identified group of exposed workers in Ireland. PMID:17223639

  19. Quantification of Proton Dose Calculation Accuracy in the Lung

    SciTech Connect

    Grassberger, Clemens; Daartz, Juliane; Dowdell, Stephen; Ruggieri, Thomas; Sharp, Greg; Paganetti, Harald

    2014-06-01

    Purpose: To quantify the accuracy of a clinical proton treatment planning system (TPS) as well as Monte Carlo (MC)–based dose calculation through measurements and to assess the clinical impact in a cohort of patients with tumors located in the lung. Methods and Materials: A lung phantom and ion chamber array were used to measure the dose to a plane through a tumor embedded in the lung, and to determine the distal fall-off of the proton beam. Results were compared with TPS and MC calculations. Dose distributions in 19 patients (54 fields total) were simulated using MC and compared to the TPS algorithm. Results: MC increased dose calculation accuracy in lung tissue compared with the TPS and reproduced dose measurements in the target to within ±2%. The average difference between measured and predicted dose in a plane through the center of the target was 5.6% for the TPS and 1.6% for MC. MC recalculations in patients showed a mean dose to the clinical target volume on average 3.4% lower than the TPS, exceeding 5% for small fields. For large tumors, MC also predicted consistently higher V5 and V10 to the normal lung, because of a wider lateral penumbra, which was also observed experimentally. Critical structures located distal to the target could show large deviations, although this effect was highly patient specific. Range measurements showed that MC can reduce range uncertainty by a factor of ∼2: the average (maximum) difference to the measured range was 3.9 mm (7.5 mm) for MC and 7 mm (17 mm) for the TPS in lung tissue. Conclusion: Integration of Monte Carlo dose calculation techniques into the clinic would improve treatment quality in proton therapy for lung cancer by avoiding systematic overestimation of target dose and underestimation of dose to normal lung. In addition, the ability to confidently reduce range margins would benefit all patients by potentially lowering toxicity.

  20. Methemoglobin-Based Biological Dose Assessment for Human Blood.

    PubMed

    Zhang, Xiao-Hong; Hu, Xiao-Dan; Zhao, Su-Ying; Xie, Li-Hua; Miao, Yu-Ji; Li, Qun; Min, Rui; Liu, Pei-Dang; Zhang, Hai-Qian

    2016-07-01

    Methemoglobin is an oxidative form of hemoglobin in erythrocytes. The authors' aim was to develop a new biological dosimeter based on a methemoglobin assay. Methemoglobin in peripheral blood (of females or males) that was exposed to a Co source (0.20 Gy min) was quantified using an enzyme-linked immunosorbent assay. The dose range was 0.5-8.0 Gy. In a time-course experiment, the time points 0, 0.02, 1, 2, 3, 7, 15, 21, and 30 d after 4-Gy irradiation of heparinized peripheral blood were used. Methemoglobin levels in a lysed erythrocyte pellet from the irradiated blood of females and males increased with the increasing dose. Methemoglobin levels in female blood irradiated with γ-doses more than 4 Gy were significantly higher than those in male samples at the same doses. Two dose-response relations were fitted to the straight line: one is with the correlation coefficient of 0.98 for females, and the other is with the correlation coefficient of 0.99 for males. The lower limit of dose assessment based on methemoglobin is about 1 Gy. Methemoglobin levels in blood as a result of auto-oxidation increase after 7-d storage at -20 °C. The upregulation of methemoglobin induced by γ-radiation persists for ∼3 d. The absorbed doses that were estimated using the two dose-response relations were close to the actual doses. The results suggest that methemoglobin can be used as a rapid and accurate biological dosimeter for early assessment of absorbed γ-dose in human blood. PMID:27218292

  1. Titration of amlodipine to higher doses: a comparison of Asian and Western experience.

    PubMed

    Kario, Kazuomi; Robbins, Jeffery; Jeffers, Barrett W

    2013-01-01

    In this retrospective analysis, data pooled from two Phase III/IV open-label Asian studies were used to quantify the additional blood pressure efficacy achieved when titrating amlodipine from 5 mg to 10 mg in mild/moderate hypertensive patients, and compared to data pooled from three Western studies. The primary efficacy end point was the change from baseline in sitting systolic blood pressure (SBP) and diastolic blood pressure (DBP) to the specified time point (4-8 weeks, depending on the trial). For the Asian analysis (n=174), both mean SBP and DBP were significantly decreased at the final visit (SBP -13.3 mmHg, 95% confidence interval [CI] -15.5 to -11.0; DBP -9.2 mmHg, 95% CI -10.6 to -7.8; both P<0.0001). These results were similar to the Western analysis (n=369; SBP -11.5 mmHg, 95% CI -13.1 to -10.0; DBP -6.3, 95% CI -7.1 to -5.5; both P<0.0001). In summary, titration of amlodipine from 5 mg to 10 mg significantly decreased both SBP and DBP in Asian patients with mild-to-moderate hypertension. PMID:24235839

  2. Monte Carlo Study of Radiation Dose Enhancement by Gadolinium in Megavoltage and High Dose Rate Radiotherapy

    PubMed Central

    Zhang, Daniel G.; Feygelman, Vladimir; Moros, Eduardo G.; Latifi, Kujtim; Zhang, Geoffrey G.

    2014-01-01

    MRI is often used in tumor localization for radiotherapy treatment planning, with gadolinium (Gd)-containing materials often introduced as a contrast agent. Motexafin gadolinium is a novel radiosensitizer currently being studied in clinical trials. The nanoparticle technologies can target tumors with high concentration of high-Z materials. This Monte Carlo study is the first detailed quantitative investigation of high-Z material Gd-induced dose enhancement in megavoltage external beam photon therapy. BEAMnrc, a radiotherapy Monte Carlo simulation package, was used to calculate dose enhancement as a function of Gd concentration. Published phase space files for the TrueBeam flattening filter free (FFF) and conventional flattened 6MV photon beams were used. High dose rate (HDR) brachytherapy with Ir-192 source was also investigated as a reference. The energy spectra difference caused a dose enhancement difference between the two beams. Since the Ir-192 photons have lower energy yet, the photoelectric effect in the presence of Gd leads to even higher dose enhancement in HDR. At depth of 1.8 cm, the percent mean dose enhancement for the FFF beam was 0.38±0.12, 1.39±0.21, 2.51±0.34, 3.59±0.26, and 4.59±0.34 for Gd concentrations of 1, 5, 10, 15, and 20 mg/mL, respectively. The corresponding values for the flattened beam were 0.09±0.14, 0.50±0.28, 1.19±0.29, 1.68±0.39, and 2.34±0.24. For Ir-192 with direct contact, the enhanced were 0.50±0.14, 2.79±0.17, 5.49±0.12, 8.19±0.14, and 10.80±0.13. Gd-containing materials used in MRI as contrast agents can also potentially serve as radiosensitizers in radiotherapy. This study demonstrates that Gd can be used to enhance radiation dose in target volumes not only in HDR brachytherapy, but also in 6 MV FFF external beam radiotherapy, but higher than the currently used clinical concentration (>5 mg/mL) would be needed. PMID:25275550

  3. Dose level of occupational exposure in China.

    PubMed

    Tian, Yuan; Zhang, Liang'an; Ju, Yongjian

    2008-01-01

    This paper discusses the dose level of Chinese occupational exposures during 1986-2000. Data on occupational exposures from the main categories in nuclear fuel cycle (uranium enrichment and conversion, fuel fabrication, reactor operation, waste management and research activity, except for uranium mining and milling because of the lack of data), medical uses of radiation (diagnostic radiation, nuclear medicine and radiotherapy) and industrial uses of radiation (industrial radiography and radioisotope production) are presented and summarised in detail. These are the main components of occupational exposures in China. In general, the average annual effective doses show a steady decreasing trend over periods: from 2.16 to 1.16 mSv in medical uses of radiation during 1990-2000; from 1.92 to 1.18 mSv in industrial radiography during 1990-2000; from 8.79 to 2.05 mSv in radioisotope production during the period 1980-2000. Almost all the average annual effective doses in discussed occupations were lower than 5 mSv in recent years (except for well-logging: 6.86 mSv in 1999) and no monitored workers were found to have received the occupational exposure exceeding 50 mSv in a single year or 100 mSv in a five-year period. So the Chinese protection status of occupation exposure has been improved in recent years. However, the average annual effective doses in some occupations, such as diagnostic radiology and coal mining, were still much higher than that of the whole world. There are still needs for further improvement and careful monitoring of occupational exposure to protect every worker from excessive occupational exposure, especially for the workers who were neglected before. PMID:17878147

  4. Prediction of 10-fold coordinated TiO2 and SiO2 structures at multimegabar pressures

    PubMed Central

    Lyle, Matthew J.; Pickard, Chris J.; Needs, Richard J.

    2015-01-01

    We predict by first-principles methods a phase transition in TiO2 at 6.5 Mbar from the Fe2P-type polymorph to a ten-coordinated structure with space group I4/mmm. This is the first report, to our knowledge, of the pressure-induced phase transition to the I4/mmm structure among all dioxide compounds. The I4/mmm structure was found to be up to 3.3% denser across all pressures investigated. Significant differences were found in the electronic properties of the two structures, and the metallization of TiO2 was calculated to occur concomitantly with the phase transition to I4/mmm. The implications of our findings were extended to SiO2, and an analogous Fe2P-type to I4/mmm transition was found to occur at 10 TPa. This is consistent with the lower-pressure phase transitions of TiO2, which are well-established models for the phase transitions in other AX2 compounds, including SiO2. As in TiO2, the transition to I4/mmm corresponds to the metallization of SiO2. This transformation is in the pressure range reached in the interiors of recently discovered extrasolar planets and calls for a reformulation of the equations of state used to model them. PMID:25991859

  5. Prediction of 10-fold coordinated TiO2 and SiO2 structures at multimegabar pressures.

    PubMed

    Lyle, Matthew J; Pickard, Chris J; Needs, Richard J

    2015-06-01

    We predict by first-principles methods a phase transition in TiO2 at 6.5 Mbar from the Fe2P-type polymorph to a ten-coordinated structure with space group I4/mmm. This is the first report, to our knowledge, of the pressure-induced phase transition to the I4/mmm structure among all dioxide compounds. The I4/mmm structure was found to be up to 3.3% denser across all pressures investigated. Significant differences were found in the electronic properties of the two structures, and the metallization of TiO2 was calculated to occur concomitantly with the phase transition to I4/mmm. The implications of our findings were extended to SiO2, and an analogous Fe2P-type to I4/mmm transition was found to occur at 10 TPa. This is consistent with the lower-pressure phase transitions of TiO2, which are well-established models for the phase transitions in other AX2 compounds, including SiO2. As in TiO2, the transition to I4/mmm corresponds to the metallization of SiO2. This transformation is in the pressure range reached in the interiors of recently discovered extrasolar planets and calls for a reformulation of the equations of state used to model them. PMID:25991859

  6. 13 Years of TOPEX/POSEIDON Precision Orbit Determination and the 10-fold Improvement in Expected Orbit Accuracy

    NASA Technical Reports Server (NTRS)

    Lemoine, F. G.; Zelensky, N. P.; Luthcke, S. B.; Rowlands, D. D.; Beckley, B. D.; Klosko, S. M.

    2006-01-01

    Launched in the summer of 1992, TOPEX/POSEIDON (T/P) was a joint mission between NASA and the Centre National d Etudes Spatiales (CNES), the French Space Agency, to make precise radar altimeter measurements of the ocean surface. After the remarkably successful 13-years of mapping the ocean surface T/P lost its ability to maneuver and was de-commissioned January 2006. T/P revolutionized the study of the Earth s oceans by vastly exceeding pre-launch estimates of surface height accuracy recoverable from radar altimeter measurements. The precision orbit lies at the heart of the altimeter measurement providing the reference frame from which the radar altimeter measurements are made. The expected quality of orbit knowledge had limited the measurement accuracy expectations of past altimeter missions, and still remains a major component in the error budget of all altimeter missions. This paper describes critical improvements made to the T/P orbit time series over the 13-years of precise orbit determination (POD) provided by the GSFC Space Geodesy Laboratory. The POD improvements from the pre-launch T/P expectation of radial orbit accuracy and Mission requirement of 13-cm to an expected accuracy of about 1.5-cm with today s latest orbits will be discussed. The latest orbits with 1.5 cm RMS radial accuracy represent a significant improvement to the 2.0-cm accuracy orbits currently available on the T/P Geophysical Data Record (GDR) altimeter product.

  7. Gut Microbiota and Tacrolimus Dosing in Kidney Transplantation

    PubMed Central

    Lee, John R.; Muthukumar, Thangamani; Dadhania, Darshana; Taur, Ying; Jenq, Robert R.; Toussaint, Nora C.; Ling, Lilan; Pamer, Eric; Suthanthiran, Manikkam

    2015-01-01

    Tacrolimus dosing to establish therapeutic levels in recipients of organ transplants is a challenging task because of much interpatient and intrapatient variability in drug absorption, metabolism, and disposition. In view of the reported impact of gut microbial species on drug metabolism, we investigated the relationship between the gut microbiota and tacrolimus dosing requirements in this pilot study of adult kidney transplant recipients. Serial fecal specimens were collected during the first month of transplantation from 19 kidney transplant recipients who either required a 50% increase from initial tacrolimus dosing during the first month of transplantation (Dose Escalation Group, n=5) or did not require such an increase (Dose Stable Group, n=14). We characterized bacterial composition in the fecal specimens by deep sequencing of the PCR amplified 16S rRNA V4-V5 region and we investigated the hypothesis that gut microbial composition is associated with tacrolimus dosing requirements. Initial tacrolimus dosing was similar in the Dose Escalation Group and in the Stable Group (4.2±1.1 mg/day vs. 3.8±0.8 mg/day, respectively, P=0.61, two-way between-group ANOVA using contrasts) but became higher in the Dose Escalation Group than in the Dose Stable Group by the end of the first transplantation month (9.6±2.4 mg/day vs. 3.3±1.5 mg/day, respectively, P<0.001). Our systematic characterization of the gut microbial composition identified that fecal Faecalibacterium prausnitzii abundance in the first week of transplantation was 11.8% in the Dose Escalation Group and 0.8% in the Dose Stable Group (P=0.002, Wilcoxon Rank Sum test, P<0.05 after Benjamini-Hochberg correction for multiple hypotheses). Fecal Faecalibacterium prausnitzii abundance in the first week of transplantation was positively correlated with future tacrolimus dosing at 1 month (R=0.57, P=0.01) and had a coefficient±standard error of 1.0±0.6 (P=0.08) after multivariable linear regression. Our novel

  8. Higher blood flow and circulating NO products offset high-altitude hypoxia among Tibetans.

    PubMed

    Erzurum, S C; Ghosh, S; Janocha, A J; Xu, W; Bauer, S; Bryan, N S; Tejero, J; Hemann, C; Hille, R; Stuehr, D J; Feelisch, M; Beall, C M

    2007-11-01

    The low barometric pressure at high altitude causes lower arterial oxygen content among Tibetan highlanders, who maintain normal levels of oxygen use as indicated by basal and maximal oxygen consumption levels that are consistent with sea level predictions. This study tested the hypothesis that Tibetans resident at 4,200 m offset physiological hypoxia and achieve normal oxygen delivery by means of higher blood flow enabled by higher levels of bioactive forms of NO, the main endothelial factor regulating blood flow and vascular resistance. The natural experimental study design compared Tibetans at 4,200 m and U.S. residents at 206 m. Eighty-eight Tibetan and 50 U.S. resident volunteers (18-56 years of age, healthy, nonsmoking, nonhypertensive, not pregnant, with normal pulmonary function) participated. Forearm blood flow, an indicator of systemic blood flow, was measured noninvasively by using plethysmography at rest, after breathing supplemental oxygen, and after exercise. The Tibetans had more than double the forearm blood flow of low-altitude residents, resulting in greater than sea level oxygen delivery to tissues. In comparison to sea level controls, Tibetans had >10-fold-higher circulating concentrations of bioactive NO products, including plasma and red blood cell nitrate and nitroso proteins and plasma nitrite, but lower concentrations of iron nitrosyl complexes (HbFeIINO) in red blood cells. This suggests that NO production is increased and that metabolic pathways controlling formation of NO products are regulated differently among Tibetans. These findings shift attention from the traditional focus on pulmonary and hematological systems to vascular factors contributing to adaptation to high-altitude hypoxia. PMID:17971439

  9. Higher blood flow and circulating NO products offset high-altitude hypoxia among Tibetans

    PubMed Central

    Erzurum, S. C.; Ghosh, S.; Janocha, A. J.; Xu, W.; Bauer, S.; Bryan, N. S.; Tejero, J.; Hemann, C.; Hille, R.; Stuehr, D. J.; Feelisch, M.; Beall, C. M.

    2007-01-01

    The low barometric pressure at high altitude causes lower arterial oxygen content among Tibetan highlanders, who maintain normal levels of oxygen use as indicated by basal and maximal oxygen consumption levels that are consistent with sea level predictions. This study tested the hypothesis that Tibetans resident at 4,200 m offset physiological hypoxia and achieve normal oxygen delivery by means of higher blood flow enabled by higher levels of bioactive forms of NO, the main endothelial factor regulating blood flow and vascular resistance. The natural experimental study design compared Tibetans at 4,200 m and U.S. residents at 206 m. Eighty-eight Tibetan and 50 U.S. resident volunteers (18–56 years of age, healthy, nonsmoking, nonhypertensive, not pregnant, with normal pulmonary function) participated. Forearm blood flow, an indicator of systemic blood flow, was measured noninvasively by using plethysmography at rest, after breathing supplemental oxygen, and after exercise. The Tibetans had more than double the forearm blood flow of low-altitude residents, resulting in greater than sea level oxygen delivery to tissues. In comparison to sea level controls, Tibetans had >10-fold-higher circulating concentrations of bioactive NO products, including plasma and red blood cell nitrate and nitroso proteins and plasma nitrite, but lower concentrations of iron nitrosyl complexes (HbFeIINO) in red blood cells. This suggests that NO production is increased and that metabolic pathways controlling formation of NO products are regulated differently among Tibetans. These findings shift attention from the traditional focus on pulmonary and hematological systems to vascular factors contributing to adaptation to high-altitude hypoxia. PMID:17971439

  10. The absorbed dose in femur exposed to diagnostic radiography.

    PubMed

    Salehi, Z; Yusoff, A L

    2013-01-01

    A femur phantom made of wax and a real human bone was used to study the dose during radiographical procedures. The depth dose inside the phantom was determined using DOSXYZnrc, a Monte Carlo simulation software. The results were verified with measurements using TLD-100H. It was found that for 2.5 mm aluminium filtered 84-kVp X-rays, the radiation dose in the bone reached 57 % higher than the surface dose, i.e. 3.23 mGy as opposed to 2.06 mGy at the surface. The use of real bone introduces variations in the bone density in the DOSXYZnrc model, resulting in a lower attenuation effect than expected from solid bone tissues. PMID:23012482

  11. VMATc: VMAT with constant gantry speed and dose rate.

    PubMed

    Peng, Fei; Jiang, Steve B; Romeijn, H Edwin; Epelman, Marina A

    2015-04-01

    This article considers the treatment plan optimization problem for Volumetric Modulated Arc Therapy (VMAT) with constant gantry speed and dose rate (VMATc). In particular, we consider the simultaneous optimization of multi-leaf collimator leaf positions and a constant gantry speed and dose rate. We propose a heuristic framework for (approximately) solving this optimization problem that is based on hierarchical decomposition. Specifically, an iterative algorithm is used to heuristically optimize dose rate and gantry speed selection, where at every iteration a leaf position optimization subproblem is solved, also heuristically, to find a high-quality plan corresponding to a given dose rate and gantry speed. We apply our framework to clinical patient cases, and compare the resulting VMATc plans to idealized IMRT, as well as full VMAT plans. Our results suggest that VMATc is capable of producing treatment plans of comparable quality to VMAT, albeit at the expense of long computation time and generally higher total monitor units. PMID:25789937

  12. radir package: an R implementation for cytogenetic biodosimetry dose estimation.

    PubMed

    Moriña, David; Higueras, Manuel; Puig, Pedro; Ainsbury, Elizabeth A; Rothkamm, Kai

    2015-09-01

    The Bayesian framework has been shown to be very useful in cytogenetic dose estimation. This approach allows description of the probability of an event in terms of previous knowledge, e.g. its expectation and/or its uncertainty. A new R package entitled radir (radiation inverse regression) has been implemented with the aim of reproducing a recent Bayesian-type dose estimation methodology. radir adopts the method of dose estimation under the Poisson assumption of the responses (the chromosomal aberrations counts) for the required dose-response curve (typically linear or quadratic). The individual commands are described in detail and relevant examples of the use of the methods and the corresponding radir software tools are given. The suitability of this methodology is highlighted and its application encouraged by providing a user-friendly command-type software interface within the R statistical software (version 3.1.1 or higher), which includes a complete manual. PMID:26160852

  13. Total dose responses and reliability issues of 65 nm NMOSFETs

    NASA Astrophysics Data System (ADS)

    Dezhao, Yu; Qiwen, Zheng; Jiangwei, Cui; Hang, Zhou; Xuefeng, Yu; Qi, Guo

    2016-06-01

    In this paper, total dose responses and reliability issues of MOSFETs fabricated by 65 nm CMOS technology were examined. “Radiation-induced narrow channel effect” is observed in a narrow channel device. Similar to total dose responses of NMOSFETs, narrow channel NMOSFEs have larger hot-carrier-induced degradation than wide channel devices. Step Time-Dependent Dielectric Breakdown (TDDB) stresses are applied, and narrow channel devices have higher breakdown voltage than wide channel devices, which agree with “weakest link” theory of TDDB. Experimental results show that linear current, transconductance, saturated drain current and subthreshold swing are superposed degenerated by total dose irradiation and reliability issues, which may result in different lifetime from that considering total dose irradiation reliability issues separately. Project supported by “Light of West China” Program of CAS (No. XBBS201219).

  14. Fast reconstruction of low dose proton CT by sinogram interpolation

    NASA Astrophysics Data System (ADS)

    Hansen, David C.; Sangild Sørensen, Thomas; Rit, Simon

    2016-08-01

    Proton computed tomography (CT) has been demonstrated as a promising image modality in particle therapy planning. It can reduce errors in particle range calculations and consequently improve dose calculations. Obtaining a high imaging resolution has traditionally required computationally expensive iterative reconstruction techniques to account for the multiple scattering of the protons. Recently, techniques for direct reconstruction have been developed, but these require a higher imaging dose than the iterative methods. No previous work has compared the image quality of the direct and the iterative methods. In this article, we extend the methodology for direct reconstruction to be applicable for low imaging doses and compare the obtained results with three state-of-the-art iterative algorithms. We find that the direct method yields comparable resolution and image quality to the iterative methods, even at 1 mSv dose levels, while yielding a twentyfold speedup in reconstruction time over previously published iterative algorithms.

  15. Low-dose radiation: a cause of breast cancer

    SciTech Connect

    Land, C.E.

    1980-08-15

    It is likely that the breast is the organ most sensitive to radiation carcinogenesis in postpubertal women. Studies of different exposed populations have yielded remarkably consistent results, in spite of wide differences in underlying breast cancer rates and conditions of exposure. Excess risk is approximately proportional to dose, and is relatively independent of ionization density and fractionization of dose. This implies that the risk associated with low-dose exposures to ionizing radiation can be estimated with some confidence from higher-dose data. Excess risk is heavily dependent on age at exposure but relatively independent of population differences in normal risk. The temporal patterns after exposure of both radiation-induced and naturally occurring breast cancer are similar, suggesting a strong influence of factors other than radiation on radiation-induced breast cancer. Uncertainties remain about risks from exposures before puberty and after menopause.

  16. Dose escalation pharmacokinetics of intranasal scopolamine gel formulation.

    PubMed

    Wu, Lei; Boyd, Jason L; Daniels, Vernie; Wang, Zuwei; Chow, Diana S-L; Putcha, Lakshmi

    2015-02-01

    Astronauts experience Space Motion Sickness requiring treatment with an anti-motion sickness medication, scopolamine during space missions. Bioavailability after oral administration of scopolamine is low and variable, and absorption form transdermal patch is slow and prolonged. Intranasal administration achieves faster absorption and higher bioavailability of drugs that are subject to extrahepatic, first pass metabolism after oral dosing. We examined pharmacokinetics of 0.1, 0.2, and 0.4 mg doses of the Investigational New Drug formulation of intranasal scopolamine gel (INSCOP) in 12 healthy subjects using a randomized, double-blind cross-over study design. Subjects received one squirt of 0.1 g of gel containing either 0.1 mg or 0.2 mg/0.1 mL scopolamine or placebo in each nostril. Serial blood samples and total urine voids were collected after dosing and drug concentrations were determined using a modified LC-MS-MS method. Results indicate dose-linear pharmacokinetics of scopolamine with linear increases in Cmax and AUC within the dose range tested. Plasma drug concentrations were significantly lower in females than in males after administration of 0.4 dose. All three doses were well tolerated with no unexpected or serious adverse side effects reported. These results suggest that intranasal scopolamine gel formulation (INSCOP) offers a fast, reliable, and safe alternative for the treatment of motion sickness. PMID:25187210

  17. Radiation doses in chest, abdomen and pelvis CT procedures.

    PubMed

    Manssor, E; Abuderman, A; Osman, S; Alenezi, S B; Almehemeid, S; Babikir, E; Alkhorayef, M; Sulieman, A

    2015-07-01

    Computed tomography (CT) scanning is recognised as a high-radiation dose modality and estimated to be 17 % of the radiological procedure and responsible for 70 % of medical radiation exposure. Although diagnostic X rays provide great benefits, their use involves some risk for developing cancer. The objectives of this study are to estimate radiation doses during chest, abdomen and pelvis CT. A total of 51 patients were examined for the evaluation of metastasis of a diagnosed primary tumour during 4 months. A calibrated CT machine from Siemens 64 slice was used. The mean age was 48.0 ± 18.6 y. The mean patient weight was 73.8 ± 16.1 kg. The mean dose-length product was 1493.8 ± 392.1 mGy cm, Volume CT dose index (CTDI vol) was 22.94 ± 5.64 mGy and the mean effective dose was 22.4 ± 5.9 mSv per procedure. The radiation dose per procedure was higher as compared with previous studies. Therefore, the optimisation of patient's radiation doses is required in order to reduce the radiation risk. PMID:25852181

  18. Influence of the dosing interval on prolactin release after remoxipride.

    PubMed Central

    Movin-Osswald, G; Hammarlund-Udenaes, M; Von Bahr, C; Eneroth, P; Walton-Bowen, K

    1995-01-01

    1. The prolactin response following administration of the D2-dopamine receptor antagonist remoxipride was studied in eight healthy male volunteers. The purpose of the study was to investigate the duration of a refractory period of prolactin release following two doses of remoxipride. A further aim was to compare the prolactin response following remoxipride and thyrotropin release hormone (TRH) during the refractory period. The subjects received two 30 min intravenous (i.v.) infusions of remoxipride 50 mg with different time intervals between the two doses, in a randomized six period crossover design. The time intervals between the two remoxipride doses were 2, 8, 12, 24 and 48 h. On one occasion the remoxipride dose was followed by an i.v. injection of TRH after 2 h. 2. The plasma peak prolactin concentrations obtained after the first remoxipride dose correspond to a maximal release of prolactin according to earlier studies. A small second peak of prolactin was observed after 2 h. The release was gradually increased with longer time intervals between the consecutive doses. The refractory period for a second prolactin release similar to the first one after remoxipride was found to be 24 h for most of the subjects. 3. TRH resulted in a faster and higher increase in prolactin response of a shorter duration than after remoxipride administered 2 h after the first dose. PMID:7669486

  19. Estimate Radiological Dose for Animals

    1997-12-18

    Estimate Radiological dose for animals in ecological environment using open literature values for parameters such as body weight, plant and soil ingestion rate, rad. halflife, absorbed energy, biological halflife, gamma energy per decay, soil-to-plant transfer factor, ...etc

  20. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1991-01-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon and Washington, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on human (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data; Demographics, Agriculture, Food Habits and; Environmental Pathways and Dose Estimates.

  1. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    McMakin, A.H.; Cannon, S.D.; Finch, S.M.

    1992-07-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates. Progress is discussed.

  2. Estimating and reducing dose received by cardiac devices for patients undergoing radiotherapy.

    PubMed

    Bourgouin, Alexandra; Varfalvy, Nicolas; Archambault, Louis

    2015-01-01

    The objectives of this project are to quantify the dose reduction effect provided by a lead shield for patients with cardiac implantable electronic devices (CIED) during a clinically realistic radiation treatment on phantom and to provide a simple model of dose estimation to predict dose received by CIED in a wide range of situations. The shield used in this project is composed of a lead sheet wrapped in thermoplastic. Dose measurements were made with a plastic scintillation detector (PSD). The phantom was treated with ten different plans. Three of these cases were treated with intensity-modulated radiation therapy (IMRT) and the others received standard 3D conformal radiation therapy (3D CRT). Lateral dose measurement for photon fields was made to establish a dose prediction model. On average, the use of the lead shield reduced the dose to CIEDs by 19% ± 13%. Dose reduction was most important for breast cases, with a mean reduction of 31% ± 15%. In three cases, the total dose reduction was more than 25 cGy over the complete treatment. For the three IMRT cases, the mean dose reduction was 11% ± 9%. On average, the difference between the TPS prediction and the measurement was 71%, while it was only 14% for the dose prediction model. It was demonstrated that a lead shield can be efficiently used for reducing doses to CIED with a wide range of clinical plans. In patients treated with IMRT modality treatment, the shielding should be used only for those with more than two anterior fields over seven fields. In the case of 3D CRT patients, the shielding should be used for those with a dose on the CIED higher than 50 cGy and with a reduction of dose higher than 10 cGy. The dose prediction model developed in this study can be an easy way to have a better estimation of the out-of-field dose than the TPS. PMID:26699550

  3. Higher Education: A Growth Industry?

    ERIC Educational Resources Information Center

    Bowen, Howard R.

    1974-01-01

    Discusses the implications for the future of higher education by examining data concerning demographic factors, growth projections, supply factors, expansion concerns, health care needs, and manpower supplies. (Author/PG)

  4. Trends in Higher Education Computing.

    ERIC Educational Resources Information Center

    Thomas, Charles R.

    1984-01-01

    Discusses the effects which changes in computer technology are having on the organization, staffing, and budgets at institutions of higher education. Trends in computer hardware, computer software, and in office automation are also discussed. (JN)

  5. Synthesis of higher monocarboxylic acids

    SciTech Connect

    Taikov, B.F.; Novakovskii, E.M.; Zhelkovskaya, V.P.; Shadrova, V.N.; Shcherbik, P.K.

    1981-01-01

    Brown-coal and peat waxes contain higher monocarboxylic acids, alcohols and esters of them as their main components. In view of this, considerable interest is presented by the preparation of individual compounds among those mentioned above, which is particularly important in the study of the composition and development of the optimum variants of the chemical processing of the waxes. In laboratory practice, to obtain higher monocarboxylic acids use is generally made of electrosynthesis according to Kolbe which permits unbranched higher aliphatic acids with given lengths of the hydrocarbon chain to be obtained. The aim of the present work was to synthesize higher monocarboxylic acids: arachidic, behenic, lignoceric, pentacosanoic, erotic, heptacosanoic, montanic, nonacosanoic, melissic, dotriacontanoic and tetratriacontanoic, which are present in waxes. Characteristics of synthesized acids are tabulated. 20 refs.

  6. Differentiation of Higher Education Institutions.

    ERIC Educational Resources Information Center

    Cazenave, P.; Lapointe, S.

    1983-01-01

    Historical and political influences in the trend toward diversification in French universities are traced. Related issues discussed include institutional versus governmental preferences, institutional functions (curriculum, vocational training, research), and implications for the quality and democratization of higher education. (MSE)

  7. Higher Education: Labor Market Linkage.

    ERIC Educational Resources Information Center

    Asayeghn, Desta

    1982-01-01

    Examines the methodology of three case studies investigating the linkage between higher education and the world of work in the Sudan, Zambia, and Tanzania. Summarizes 12 main findings. Suggests the studies remain traditional human resources planning efforts. (NEC)

  8. Absorbed dose simulations in near-surface regions using high dose rate Iridium-192 sources applied for brachytherapy

    NASA Astrophysics Data System (ADS)

    Moura, E. S.; Zeituni, C. A.; Sakuraba, R. K.; Gonçalves, V. D.; Cruz, J. C.; Júnior, D. K.; Souza, C. D.; Rostelato, M. E. C. M.

    2014-02-01

    Brachytherapy treatment with Iridium-192 high dose rate (HDR) sources is widely used for various tumours and it could be developed in many anatomic regions. Iridium-192 sources are inserted inside or close to the region that will be treated. Usually, the treatment is performed in prostate, gynaecological, lung, breast and oral cavity regions for a better clinical dose coverage compared with other techniques, such as, high energy photons and Cobalt-60 machines. This work will evaluate absorbed dose distributions in near-surface regions around Ir-192 HDR sources. Near-surface dose measurements are a complex task, due to the contribution of beta particles in the near-surface regions. These dose distributions should be useful for non-tumour treatments, such as keloids, and other non-intracavitary technique. For the absorbed dose distribution simulations the Monte Carlo code PENELOPE with the general code penEasy was used. Ir-192 source geometry and a Polymethylmethacrylate (PMMA) tube, for beta particles shield were modelled to yield the percentage depth dose (PDD) on a cubic water phantom. Absorbed dose simulations were realized at the central axis to yield the Ir-192 dose fall-off along central axis. The results showed that more than 99.2% of the absorbed doses (relative to the surface) are deposited in 5 cm depth but with slower rate at higher distances. Near-surface treatments with Ir-192 HDR sources yields achievable measurements and with proper clinical technique and accessories should apply as an alternative for treatment of lesions where only beta sources were used.

  9. Improvements in extremity dose assessment for ionising radiation medical applications.

    PubMed

    Ginjaume, M; Pérez, S; Ortega, X

    2007-01-01

    This study aims at testing the INTE ring dosemeter based on MCP-Ns and TLD-100 detectors on users from the field of medical applications, namely radiopharmacists, personnel at a cyclotron facility with corresponding FDG synthesis cells, interventional radiology technologists and radiologists. These users were chosen due to the fact that they have a significantly high risk of exposure to their hands. Following previous results, MCP-Ns TL thin material was used for radiology measurements, whereas TLD-100 was preferred for other applications. The dosemeters were tested to make sure that they were waterproof and that they could be sterilised properly prior to use. Results confirm the need to implement finger dosimetry, mainly for interventional radiologists as finger dose can be >50 times higher than whole-body dose and 3 times higher than wrist dose. PMID:17277325

  10. Technical basis for dose reconstruction

    SciTech Connect

    Anspaugh, L.R.

    1996-12-31

    The purpose of this paper is to consider two general topics: Technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied. 90 refs., 4 tabs.

  11. Technical basis for dose reconstruction

    SciTech Connect

    Anspaugh, L.R.

    1996-01-31

    The purpose of this paper is to consider two general topics: technical considerations of why dose-reconstruction studies should or should not be performed and methods of dose reconstruction. The first topic is of general and growing interest as the number of dose-reconstruction studies increases, and one asks the question whether it is necessary to perform a dose reconstruction for virtually every site at which, for example, the Department of Energy (DOE) has operated a nuclear-related facility. And there is the broader question of how one might logically draw the line at performing or not performing dose-reconstruction (radiological and chemical) studies for virtually every industrial complex in the entire country. The second question is also of general interest. There is no single correct way to perform a dose-reconstruction study, and it is important not to follow blindly a single method to the point that cheaper, faster, more accurate, and more transparent methods might not be developed and applied.

  12. Ultraviolet radiation cataract: dose dependence

    NASA Astrophysics Data System (ADS)

    Soderberg, Per G.; Loefgren, Stefan

    1994-07-01

    Current safety limits for cataract development after acute exposure to ultraviolet radiation (UVR) are based on experiments analyzing experimental data with a quantal, effect-no effect, dose-response model. The present study showed that intensity of forward light scattering is better described with a continuous dose-response model. It was found that 3, 30 and 300 kJ/m2UVR300nm induces increased light scattering within 6 h. For all three doses the intensity of forward light scattering was constant after 6 h. The intensity of forward light scattering was proportional to the log dose of UVR300nm. There was a slight increase of the intensity of forward light scattering on the contralateral side in animals that received 300 kJ/m2. Altogether 72 Sprague-Dawley male rats were included. Half of the rats were exposed in vivo on one side to UVR300nm. The other half was kept as a control group, receiving the same treatment as exposed rats but without delivery of UVR300nm to the eye. Subgroups of the rats received either of the three doses. Rats were sacrificed at varying intervals after the exposure. The lenses were extracted and the forward light scattering was estimated. It is concluded that intensity of forward light scattering in the lens after exposure to UVR300nm should be described with a continuous dose-reponse model.

  13. Weldon Spring historical dose estimate

    SciTech Connect

    Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

    1986-07-01

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.

  14. Coaching Reduced the Radiation Dose of Pain Physicians by Half during Interventional Procedures.

    PubMed

    Slegers, A S; Gültuna, I; Aukes, J A; van Gorp, E J J A A; Blommers, F M N; Niehof, S P; Bosman, J

    2015-06-01

    The increased use of C-arm fluoroscopy in interventional pain management has led to higher radiation exposure for pain physicians. This study investigated whether or not real-time radiation dose feedback with coaching can reduce the scatter dose received by pain physicians. Firstly, phantom measurements were made to create a scatter dose profile, which visualizes the average scatter radiation for different C-arm positions at 3 levels of height. Secondly, in the clinical part, the radiation dose received by pain physicians during pain treatment procedures was measured real-time to evaluate (1) the effect of real-time dose feedback on the received scatter dose, and (2) the effect of knowledge of the scatter dose profile and active coaching, on the scatter dose received by the pain physician. The clinical study included 330 interventional pain procedures. The results showed that real-time feedback of the received dose did not lead to a reduction in scatter radiation. However, visualization of the scatter dose in a scatter dose profile and active coaching on optimal positions did reduce the scatter radiation received by pain physicians during interventional pain procedures by 46.4% (P = 0.05). Knowledge of and real-time coaching with the scatter dose profile reduced the dose of pain physicians by half, caused by their increased awareness for scatter radiation and their insight into strategic positioning. PMID:25354342

  15. Estimating Annual Individual Doses for Evacuees Returning Home to Areas Affected by the Fukushima Nuclear Accident.

    PubMed

    Yajima, Kazuaki; Kurihara, Osamu; Ohmachi, Yasushi; Takada, Masashi; Omori, Yasutaka; Akahane, Keiichi; Kim, Eunjoo; Torikoshi, Masami; Yonehara, Hidenori; Yoshida, Satoshi; Sakai, Kazuo; Akashi, Makoto

    2015-08-01

    To contribute to the reconstruction and revitalization of Fukushima Prefecture following the 2011 nuclear power disaster, annual individual doses were estimated for evacuees who will return home to Tamura City, Kawauchi Village, and Iitate Village in Fukushima. Ambient external dose rates and individual doses obtained with personal dosimeters were measured at many residential and occupational sites throughout the study areas to obtain fundamental data needed for the estimation. The measurement results indicated that the ratio of individual dose based on a personal dosimeter to the ambient external dose measurement was 0.7 with 10% uncertainty. Multiplying the ambient external dose by 0.7 may be an appropriate measure of the effective dose to an individual in the investigated area. Annual individual doses were estimated for representative lifestyles and occupations based on the ambient external dose rates at the measurement sites, taking into account the relationship between the ambient external dose and individual dose. The results were as follows: 0.6-2.3 mSv y in Tamura, 1.1-5.5 mSv y in Kawauchi, and 3.8-17 mSv y in Iitate. For all areas investigated, the estimated dose to outdoor workers was higher than that to indoor workers. Identifying ways to reduce the amount of time that an outdoor worker spends outdoors would provide an effective measure to reduce dose. PMID:26107433

  16. A Bayesian Dose-finding Design for Oncology Clinical Trials of Combinational Biological Agents

    PubMed Central

    Cai, Chunyan; Yuan, Ying; Ji, Yuan

    2013-01-01

    Treating patients with novel biological agents is becoming a leading trend in oncology. Unlike cytotoxic agents, for which efficacy and toxicity monotonically increase with dose, biological agents may exhibit non-monotonic patterns in their dose-response relationships. Using a trial with two biological agents as an example, we propose a dose-finding design to identify the biologically optimal dose combination (BODC), which is defined as the dose combination of the two agents with the highest efficacy and tolerable toxicity. A change-point model is used to reflect the fact that the dose-toxicity surface of the combinational agents may plateau at higher dose levels, and a flexible logistic model is proposed to accommodate the possible non-monotonic pattern for the dose-efficacy relationship. During the trial, we continuously update the posterior estimates of toxicity and efficacy and assign patients to the most appropriate dose combination. We propose a novel dose-finding algorithm to encourage sufficient exploration of untried dose combinations in the two-dimensional space. Extensive simulation studies show that the proposed design has desirable operating characteristics in identifying the BODC under various patterns of dose-toxicity and dose-efficacy relationships. PMID:24511160

  17. A Bayesian Dose-finding Design for Oncology Clinical Trials of Combinational Biological Agents.

    PubMed

    Cai, Chunyan; Yuan, Ying; Ji, Yuan

    2014-01-01

    Treating patients with novel biological agents is becoming a leading trend in oncology. Unlike cytotoxic agents, for which efficacy and toxicity monotonically increase with dose, biological agents may exhibit non-monotonic patterns in their dose-response relationships. Using a trial with two biological agents as an example, we propose a dose-finding design to identify the biologically optimal dose combination (BODC), which is defined as the dose combination of the two agents with the highest efficacy and tolerable toxicity. A change-point model is used to reflect the fact that the dose-toxicity surface of the combinational agents may plateau at higher dose levels, and a flexible logistic model is proposed to accommodate the possible non-monotonic pattern for the dose-efficacy relationship. During the trial, we continuously update the posterior estimates of toxicity and efficacy and assign patients to the most appropriate dose combination. We propose a novel dose-finding algorithm to encourage sufficient exploration of untried dose combinations in the two-dimensional space. Extensive simulation studies show that the proposed design has desirable operating characteristics in identifying the BODC under various patterns of dose-toxicity and dose-efficacy relationships. PMID:24511160

  18. Cord Dose Specification and Validation for Stereotactic Body Radiosurgery of Spine

    SciTech Connect

    Li Shidong Liu Yan; Chen Qing; Jin Jianyue

    2009-01-01

    Effective dose to a portion of the spinal cord in treatment segment, rather than the maximum point dose in the cord surface, was set as the dose limit in stereotactic-body radiosurgery (SBRS) of spine. Such a cord dose specification is sensitive to the volume size and position errors. Thus, we used stereotactic image guidance to minimize phantom positioning errors and compared the results of a 0.6-cm{sup 3} Farmer ionization chamber and a 0.01-cm{sup 3} compact ionization chamber to determine the detector size effect on 9 SBRS cases. The experimental errors ranging from 2% to 7% were estimated by the deviation of the mean dose in plans to the chamber with spatial displacements of 0.5 mm. The mean and measured doses for the large chamber to individual cases were significantly ({approx}17%) higher than the doses with the compact chamber placed at the same point. Our experimental results shown that the mean doses to the volume of interest could represent the measured cord doses. For the 9 patients, the mean doses to 10% of the cord were about 10 Gy, while the maximum cord doses varied from 11.6 to 17.6 Gy. The mean dose, possibly correlated with the cord complication, provided us an alternative and reliable cord dose specification in SBRS of spine.

  19. The Effect of Patient Weight and Provider Training and Experience on Dosing of Rocuronium

    PubMed Central

    Rodriguez, L.; Banks, S.; Major, B. T.; Rodriguez, Y.

    2016-01-01

    Introduction. Maintenance dosing of neuromuscular blocking agents is complex and varies with patient, procedure, and clinical situation. With this in mind, we sought to identify factors impacting the maintenance dosing of neuromuscular blockers as a step toward identifying best practice with respect to minimizing residual neuromuscular blockade. Methods. Cases utilizing rocuronium from July 1, 2010, to June 30, 2014, at the sponsoring institution were analyzed. Using a mixed model to account for repeated measures, patients were analyzed by dose and weight category as defined by the World Health Organization (eight categories ranging from very severely underweight to very severely obese) as well as by the administering provider's level of experience. Results. The study included 12,671 patients with a mean age of 49.7 (SD 16.7). Increasing weight category and higher levels of provider experience were associated with higher doses for rocuronium. There were no differences in initial dose or in frequency of maintenance dosing by weight category after controlling for case length. Discussion. The two dosing patterns identified, higher doses for overweight patients and higher doses administered by experienced providers, are modifiable factors that could enhance patient safety. PMID:27429615

  20. Micropellet-loaded rods with dose-independent sustained release properties for individual dosing via the Solid Dosage Pen.

    PubMed

    Laukamp, Eva Julia; Knop, Klaus; Thommes, Markus; Breitkreutz, Joerg

    2016-02-29

    Individual dosing of medicines is relevant for paediatrics, geriatrics and personalised medicine. The Solid Dosage Pen (SDP) allows for individual dosing by cutting monolithic, tablet-like drug carriers of pre-defined heights. The aim of the present study was to develop micropellet-loaded rods (MPLRs) with dose-independent sustained release properties for individual dosing via the Solid Dosage Pen. Therefore, micropellets were successfully layered with carbamazepine and coated with polyvinyl acetate (PVAc) and PVAc/polyvinyl alcohol-polyethylene glycol (PVA-PEG). The tensile strength of the sustained release micropellets (300-450 μm) was more than two times higher (12.6-17.1 MPa) than pressures occurring during ram-extrusion of the MPLRs (below 5.8 MPa). Due to relative crystallinities above 93% for PVAc and PVA-PEG a low solubility of the coating films within the PEG-matrix was observed. The sustained release micropellets were successfully incorporated into MPLRs. Drug release properties of the pellets maintained after embedding into the matrix. Hence, the MPLRs provided dose-independent prolonged drug liberation which was not achieved for drug-loaded rods before. The MPLRs permitted the application of the SDP with a precise drug delivery from individually cut single doses. Storage stability was proven for MPLRs containing PVAc/PVA-PEG coated pellets. In conclusion, the MPLRs combined the advantages of multiparticulate dosage forms with the SDP as a device for individual dosing. PMID:26757149

  1. High dose medroxyprogesterone acetate (MPA) treatment in metastatic carcinoma of the breast: a dose-response evaluation.

    PubMed

    Cuna, G R; Calciati, A; Strada, M R; Bumma, C; Campio, L

    1978-04-30

    The results of controlled clinical trial that used high doses of medroxyprogesterone acetate (MPA) in the treatment of metastatic breast cancer are reported. Two treatment reigmens were used: regimen A, 500 mg daily with a total dose of 30 g; regimen B, 1,000 mg daily with a total dose of 60 g. The overall response rates were similar, with no statistically significant difference between the two treated groups. Regimen A (lower dosage group) reached a remission rate of 44%, whereas regimen B (higher dosage group) had a remission rate of 41%. The mean duration of response was 8 months with regimen A and 9 months with regimen B. The advantages of the lower dosage regimen as opposed to the higher dosage regimen of MPA in the treatment of advanced breast cancer are discussed. PMID:354147

  2. Revitalizing Higher Education. The Stanford Forum for Higher Education Futures.

    ERIC Educational Resources Information Center

    Meyerson, Joel W., Ed.; Massy, William F., Ed.

    This volume contains six essays on higher education which provide lessons and successful techniques for meeting the challenges of the future. The first essay, "Academic Renewal at Michigan" (James Duderstadt), describes the modern research university as a complex corporate conglomerate in danger of diluting its core business. The successful…

  3. Higher Education Accounting Manual. Utah Coordinating Council of Higher Education.

    ERIC Educational Resources Information Center

    Utah State Coordinating Council of Higher Education, Salt Lake City.

    Recognition of a critical need for accurate and detailed information to refine the process of budgeting funds for higher education in Utah led to the preparation of this accounting manual for universities and colleges in the state. The manual presents guidelines for the uniform accounting and reporting of financial and statistical data, and is…

  4. The Hesburgh Papers: Higher Values in Higher Education.

    ERIC Educational Resources Information Center

    Hesburgh, Theodore M.

    In this book the president of Notre Dame University responds to the critics who see the teaching of religion and values as a hindrance to institutions of higher learning, suggesting that no university is truly a university unless it is universal and moves every scholar to look to the total universe. The significance of values in education is…

  5. Radiological dose assessment for vault storage concepts

    SciTech Connect

    Richard, R.F.

    1997-02-25

    This radiological dose assessment presents neutron and photon dose rates in support of project W-460. Dose rates are provided for a single 3013 container, the ``infloor`` storage vault concept, and the ``cubicle`` storage vault concept.

  6. A Randomized Controlled Trial of Increased Dose and Frequency of Albendazole with Standard Dose DEC for Treatment of Wuchereria bancrofti Microfilaremics in Odisha, India

    PubMed Central

    Kerketa, Anna Salomi; Maharana, Antaryami; Panda, Sudanshu S; Mohanty, Prafulla Chandra; Horton, John; Ramachandran, Cherubala P

    2015-01-01

    Although current programmes to eliminate lymphatic filariasis have made significant progress it may be necessary to use different approaches to achieve the global goal, especially where compliance has been poor and ‘hot spots’ of continued infection exist. In the absence of alternative drugs, the use of higher or more frequent dosing with the existing drugs needs to be explored. We examined the effect of higher and/or more frequent dosing with albendazole with a fixed 300mg dose of diethylcarbamazine in a Wuchereria bancrofti endemic area in Odisha, India. Following screening, 104 consenting adults were randomly assigned to treatment with the standard regimen annually for 24 months (S1), or annually with increased dose (800mg albendazole)(H1) or with increased frequency (6 monthly) with either standard (S2) or increased (H2) dose. Pre-treatment microfilaria counts (GM) ranged from 348 to 459 mf/ml. Subjects were followed using microfilaria counts, OG4C3 antigen levels and ultrasound scanning for adult worm nests. Microfilarial counts tended to decrease more rapidly with higher or more frequent dosing at all time points. At 12 months, Mf clearance was marginally greater with the high dose regimens, while by 24 months, there was a trend to higher Mf clearance in the arm with increased frequency and 800mg of albendazole (76.9%) compared to other arms, (S1:64%, S2:69.2% & H1:73.1%). Although higher and/or more frequent dosing showed a trend towards a greater decline in antigenemia and clearance of “nests”, all regimens demonstrated the potential macrofilaricidal effect of the combination. The higher doses of albendazole did not result in a greater number or more severe side effects. The alternative regimens could be useful in the later stages of existing elimination programmes or achieving elimination more rapidly in areas where programmes have yet to start. PMID:25781977

  7. A randomized controlled trial of increased dose and frequency of albendazole with standard dose DEC for treatment of Wuchereria bancrofti microfilaremics in Odisha, India.

    PubMed

    Kar, Shantanu Kumar; Dwibedi, Bhagirathi; Kerketa, Anna Salomi; Maharana, Antaryami; Panda, Sudanshu S; Mohanty, Prafulla Chandra; Horton, John; Ramachandran, Cherubala P

    2015-03-01

    Although current programmes to eliminate lymphatic filariasis have made significant progress it may be necessary to use different approaches to achieve the global goal, especially where compliance has been poor and 'hot spots' of continued infection exist. In the absence of alternative drugs, the use of higher or more frequent dosing with the existing drugs needs to be explored. We examined the effect of higher and/or more frequent dosing with albendazole with a fixed 300 mg dose of diethylcarbamazine in a Wuchereria bancrofti endemic area in Odisha, India. Following screening, 104 consenting adults were randomly assigned to treatment with the standard regimen annually for 24 months (S1), or annually with increased dose (800 mg albendazole)(H1) or with increased frequency (6 monthly) with either standard (S2) or increased (H2) dose. Pre-treatment microfilaria counts (GM) ranged from 348 to 459 mf/ml. Subjects were followed using microfilaria counts, OG4C3 antigen levels and ultrasound scanning for adult worm nests. Microfilarial counts tended to decrease more rapidly with higher or more frequent dosing at all time points. At 12 months, Mf clearance was marginally greater with the high dose regimens, while by 24 months, there was a trend to higher Mf clearance in the arm with increased frequency and 800 mg of albendazole (76.9%) compared to other arms, (S1:64%, S2:69.2% & H1:73.1%). Although higher and/or more frequent dosing showed a trend towards a greater decline in antigenemia and clearance of "nests", all regimens demonstrated the potential macrofilaricidal effect of the combination. The higher doses of albendazole did not result in a greater number or more severe side effects. The alternative regimens could be useful in the later stages of existing elimination programmes or achieving elimination more rapidly in areas where programmes have yet to start. PMID:25781977

  8. Concurrent image and dose reconstruction for image guided radiation therapy

    NASA Astrophysics Data System (ADS)

    Sheng, Ke

    The importance of knowing the patient actual position is essential for intensity modulated radiation therapy (IMRT). This procedure uses tightened margin and escalated tumor dose. In order to eliminate the uncertainty of the geometry in IMRT, daily imaging is prefered. The imaging dose, limited field of view and the imaging concurrency of the MVCT (mega-voltage computerized tomography) are investigated in this work. By applying partial volume imaging (PVI), imaging dose can be reduced for a region of interest (ROI) imaging. The imaging dose and the image quality are quantitatively balanced with inverse imaging dose planning. With PVI, 72% average imaging dose reduction was observed on a typical prostate patient case. The algebraic reconstruction technique (ART) based projection onto convex sets (POCS) shows higher robustness than filtered back projection when available imaging data is not complete and continuous. However, when the projection is continuous as in the actual delivery, a non-iterative wavelet based multiresolution local tomography (WMLT) is able to achieve 1% accuracy within the ROI. The reduction of imaging dose is dependent on the size of ROI. The improvement of concurrency is also discussed based on the combination of PVI and WMLT. Useful target images were acquired with treatment beams and the temporal resolution can be increased to 20 seconds in tomotherapy. The data truncation problem with the portal imager was also studied. Results show that the image quality is not adversely affected by truncation when WMLT is employed. When the online imaging is available, a perturbation dose calculation (PDC) that estimates the actual delivered dose is proposed. Corrected from the Fano's theorem, PDC counts the first order term in the density variation to calculate the internal and external anatomy change. Although change in the dose distribution that is caused by the internal organ motion is less than 1% for 6 MV beams, the external anatomy change has

  9. Black Holes in Higher Dimensions

    NASA Astrophysics Data System (ADS)

    Horowitz, Gary T.

    2012-04-01

    List of contributors; Preface; Part I. Introduction: 1. Black holes in four dimensions Gary Horowitz; Part II. Five Dimensional Kaluza-Klein Theory: 2. The Gregory-Laflamme instability Ruth Gregory; 3. Final state of Gregory-Laflamme instability Luis Lehner and Frans Pretorius; 4. General black holes in Kaluza-Klein theory Gary Horowitz and Toby Wiseman; Part III. Higher Dimensional Solutions: 5. Myers-Perry black holes Rob Myers; 6. Black rings Roberto Emparan and Harvey Reall; Part IV. General Properties: 7. Constraints on the topology of higher dimensional black holes Greg Galloway; 8. Blackfolds Roberto Emparan; 9. Algebraically special solutions in higher dimensions Harvey Reall; 10. Numerical construction of static and stationary black holes Toby Wiseman; Part V. Advanced Topics: 11. Black holes and branes in supergravity Don Marolf; 12. The gauge/gravity duality Juan Maldacena; 13. The fluid/gravity correspondence Veronika Hubeny, Mukund Rangamani and Shiraz Minwalla; 14. Horizons, holography and condensed matter Sean Hartnoll; Index.

  10. Notes on the effect of dose uncertainty

    SciTech Connect

    Morris, M.D.

    1987-01-01

    The apparent dose-response relationship between amount of exposure to acute radiation and level of mortality in humans is affected by uncertainties in the dose values. It is apparent that one of the greatest concerns regarding the human data from Hiroshima and Nagasaki is the unexpectedly shallow slope of the dose response curve. This may be partially explained by uncertainty in the dose estimates. Some potential effects of dose uncertainty on the apparent dose-response relationship are demonstrated.

  11. High-dose Helical Tomotherapy With Concurrent Full-dose Chemotherapy for Locally Advanced Pancreatic Cancer

    SciTech Connect

    Chang, Jee Suk; Wang, Michael L.C.; Koom, Woong Sub; Yoon, Hong In; Chung, Yoonsun; Song, Si Young; Seong, Jinsil

    2012-08-01

    Purpose: To improve poor therapeutic outcome of current practice of chemoradiotherapy (CRT), high-dose helical tomotherapy (HT) with concurrent full-dose chemotherapy has been performed on patients with locally advanced pancreatic cancer (LAPC), and the results were analyzed. Methods and Materials: We retrospectively reviewed 39 patients with LAPC treated with radiotherapy using HT (median, 58.4 Gy; range, 50.8-59.9 Gy) and concomitant chemotherapy between 2006 and 2009. Radiotherapy was directed to the primary tumor with a 0.5-cm margin without prophylactic nodal coverage. Twenty-nine patients (79%) received full-dose (1000 mg/m{sup 2}) gemcitabine-based chemotherapy during HT. After completion of CRT, maintenance chemotherapy was administered to 37 patients (95%). Results: The median follow-up was 15.5 months (range, 3.4-43.9) for the entire cohort, and 22.5 months (range, 12.0-43.9) for the surviving patients. The 1- and 2-year local progression-free survival rates were 82.1% and 77.3%, respectively. Eight patients (21%) were converted to resectable status, including 1 with a pathological complete response. The median overall survival and progression-free survival were 21.2 and 14.0 months, respectively. Acute toxicities were acceptable with no gastrointestinal (GI) toxicity higher than Grade 3. Severe late GI toxicity ({>=}Grade 3) occurred in 10 patients (26%); 1 treatment-related death from GI bleeding was observed. Conclusion: High-dose helical tomotherapy with concurrent full-dose chemotherapy resulted in improved local control and long-term survival in patients with LAPC. Future studies are needed to widen the therapeutic window by minimizing late GI toxicity.

  12. Dose reconstruction for real-time patient-specific dose estimation in CT

    SciTech Connect

    De Man, Bruno Yin, Zhye; Wu, Mingye; FitzGerald, Paul; Kalra, Mannudeep

    2015-05-15

    Purpose: Many recent computed tomography (CT) dose reduction approaches belong to one of three categories: statistical reconstruction algorithms, efficient x-ray detectors, and optimized CT acquisition schemes with precise control over the x-ray distribution. The latter category could greatly benefit from fast and accurate methods for dose estimation, which would enable real-time patient-specific protocol optimization. Methods: The authors present a new method for volumetrically reconstructing absorbed dose on a per-voxel basis, directly from the actual CT images. The authors’ specific implementation combines a distance-driven pencil-beam approach to model the first-order x-ray interactions with a set of Gaussian convolution kernels to model the higher-order x-ray interactions. The authors performed a number of 3D simulation experiments comparing the proposed method to a Monte Carlo based ground truth. Results: The authors’ results indicate that the proposed approach offers a good trade-off between accuracy and computational efficiency. The images show a good qualitative correspondence to Monte Carlo estimates. Preliminary quantitative results show errors below 10%, except in bone regions, where the authors see a bigger model mismatch. The computational complexity is similar to that of a low-resolution filtered-backprojection algorithm. Conclusions: The authors present a method for analytic dose reconstruction in CT, similar to the techniques used in radiation therapy planning with megavoltage energies. Future work will include refinements of the proposed method to improve the accuracy as well as a more extensive validation study. The proposed method is not intended to replace methods that track individual x-ray photons, but the authors expect that it may prove useful in applications where real-time patient-specific dose estimation is required.

  13. Survey of clinical doses from computed tomography examinations in the Canadian province of Manitoba.

    PubMed

    A Elbakri, Idris; D C Kirkpatrick, Iain

    2013-12-01

    The purpose of this study was to document CT doses for common CT examinations performed throughout the province of Manitoba. Survey forms were sent out to all provincial CT sites. Thirteen out of sixteen (81 %) sites participated. The authors assessed scans of the brain, routine abdomen-pelvis, routine chest, sinuses, lumbar spine, low-dose lung nodule studies, CT pulmonary angiograms, CT KUBs, CT colonographies and combination chest-abdomen-pelvis exams. Sites recorded scanner model, protocol techniques and patient and dose data for 100 consecutive patients who were scanned with any of the aforementioned examinations. Mean effective doses and standard deviations for the province and for individual scanners were computed. The Kruskal-Wallis test was used to compare the variability of effective doses amongst scanners. The t test was used to compare doses and their provincial ranges between newer and older scanners and scanners that used dose saving tools and those that did not. Abdomen-pelvis, chest and brain scans accounted for over 70 % of scans. Their mean effective doses were 18.0 ± 6.7, 13.2 ± 6.4 and 3.0 ± 1.0 mSv, respectively. Variations in doses amongst scanners were statistically significant. Most examinations were performed at 120 kVp, and no lower kVp was used. Dose variations due to scanner age and use of dose saving tools were not statistically significant. Clinical CT doses in Manitoba are broadly similar to but higher than those reported in other Canadian provinces. Results suggest that further dose reduction can be achieved by modifying scanning techniques, such as using lower kVp. Wide variation in doses amongst different scanners suggests that standardisation of scanning protocols can reduce patient dose. New technological advances, such as dose-reduction software algorithms, can be adopted to reduce patient dose. PMID:23803227

  14. Impact of Including Higher Actinides in Fast Reactor Transmutation Analyses

    SciTech Connect

    B. Forget; M. Asgari; R. Ferrer; S. Bays

    2007-09-01

    Previous fast reactor transmutation studies generally disregarded higher mass minor actinides beyond Cm-246 due to various considerations including deficiencies in nuclear cross-section data. Although omission of these higher mass actinides does not significantly impact the neutronic calculations and fuel cycle performance parameters follow-on neutron dose calculations related to fuel recycling, transportation and handling are significantly impacted. This report shows that including the minor actinides in the equilibrium fast reactor calculations will increase the predicted neutron emission by about 30%. In addition a sensitivity study was initiated by comparing the impact of different cross-section evaluation file for representing these minor actinides.

  15. Dose-rate dependence of heat radiosensitization

    SciTech Connect

    Gerner, E.W.; Oval, J.H.; Manning, M.R.; Sim, D.A.; Bowden, G.T.; Hevezi, J.M.

    1983-09-01

    The dose rate dependence of heat radiosensitization was studied using rat astrocytoma cells in culture and a cliniclly relevant protocol of heat dose and heat radiation sequence. Cells were treated with a minimally toxic heat dose of 43/sup 0/C for 30 minutes, after which they were irradiated with varying doses of radiation at dose rates ranging from 0.567 to 300 cGy/min. This heat dose substantially reduced the extrapolation number (n), but had little effect on D/sub 0/ of the radiation survival curve at dose rates of 50 cGy/min or greater. At dose rates less than 10 cGy/min, 43/sup 0/C for 30 min had little effect on n and only for the lowest dose rate studied (0.567 cGy/min) was there a significant reduction in D/sub 0/ (60%). The thermal enhancement ratio did not vary inversely with radiation dose rate over the dose rate range studied but, instead, was maximal at the two dose rate extremes (0.567 and 300 cGy/min). These data demonstrate that a clinically relevant heat dose enhances very low dose rate, as well as high dose rate, ionizing radiation, but suggest that little benefit is to be gained from using dose rates intermediate between conventional radiotherapeutic high dose rates or dose rates representative of interstitial implants.

  16. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S. M.; McMakin, A. H.

    1991-09-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation dose that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into five technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (i.e., dose estimates). The Source Terms Task develops estimates of radioactive emissions from Hanford facilities since 1944. The Environmental Transport Task reconstructs the movements of radioactive particles from the areas of release to populations. The Environmental Monitoring Data Task assemblies, evaluates and reports historical environmental monitoring data. The Demographics, Agriculture and Food Habits Task develops the data needed to identify the populations that could have been affected by the releases. The Environmental Pathways and Dose Estimates Task used the information derived from the other Tasks to estimate the radiation doses individuals could have received from Hanford radiation. This document lists the progress on this project as of September 1991. 3 figs., 2 tabs.

  17. AGING FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect

    R.L. Thacker

    2005-03-24

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Aging Facility performing operations to transfer aging casks to the aging pads for thermal and logistical management, stage empty aging casks, and retrieve aging casks from the aging pads for further processing in other site facilities. Doses received by workers due to aging cask surveillance and maintenance operations are also included. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation. There are no Category 1 event sequences associated with the Aging Facility (BSC 2004 [DIRS 167268], Section 7.2.1). The results of this calculation will be used to support the design of the Aging Facility and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Environmental and Nuclear Engineering.

  18. Efficacy of low-dose oral metronomic dosing of the prodrug of gemcitabine, LY2334737, in human tumor xenografts.

    PubMed

    Pratt, Susan E; Durland-Busbice, Sara; Shepard, Robert L; Donoho, Gregory P; Starling, James J; Wickremsinhe, Enaksha R; Perkins, Everett J; Dantzig, Anne H

    2013-04-01

    LY2334737, an oral prodrug of gemcitabine, is cleaved in vivo, releasing gemcitabine and valproic acid. Oral dosing of mice results in absorption of intact prodrug with slow systemic hydrolysis yielding higher plasma levels of LY2334737 than gemcitabine and prolonged gemcitabine exposure. Antitumor activity was evaluated in human colon and lung tumor xenograft models. The dose response for efficacy was examined using 3 metronomic schedules, once-a-day dosing for 14 doses, every other day for 7 doses, and once a day for 7 doses, 7 days rest, followed by an additional 7 days of once-a-day dosing. These schedules gave significant antitumor activity and were well tolerated. Oral gavage of 6 mg/kg LY2334737 daily for 21 days gave equivalent activity to i.v. 240 mg/kg gemcitabine. HCl administered once a week for 3 weeks to mice bearing a patient mesothelioma tumor PXF 1118 or a non-small cell lung cancer tumor LXFE 937. The LXFE 397 tumor possessed elevated expression of the equilibrative nucleoside transporter-1 (ENT1) important for gemcitabine uptake but not prodrug uptake and responded significantly better to treatment with LY2334737 than gemcitabine (P ≤ 0.001). In 3 colon xenografts, antitumor activity of LY2334737 plus a maximally tolerated dose of capecitabine, an oral prodrug of 5-fluorouracil, was significantly greater than either monotherapy. During treatment, the expression of carboxylesterase 2 (CES2) and concentrative nucleoside transporter-3 was induced in HCT-116 tumors; both are needed for the activity of the prodrugs. Thus, metronomic oral low-dose LY2334737 is efficacious, well tolerated, and easily combined with capecitabine for improved efficacy. Elevated CES2 or ENT1 expression may enhance LY2334737 tumor response. PMID:23371859

  19. Bladder dose-surface maps and urinary toxicity: Robustness with respect to motion in assessing local dose effects.

    PubMed

    Palorini, F; Botti, A; Carillo, V; Gianolini, S; Improta, I; Iotti, C; Rancati, T; Cozzarini, C; Fiorino, C

    2016-03-01

    The purpose of this study was to quantify the impact of inter-fraction modifications of bladder during RT of prostate cancer on bladder dose surface maps (DSM). Eighteen patients treated with daily image-guided Tomotherapy and moderate hypofractionation (70-72.8Gy at 2.5-2.6Gy/fr in 28 fractions and full bladder) were considered. Bladder contours were delineated on co-registered daily Megavoltage CT (MVCT) by a single observer and copied on the planning CT to generate dose-volume/surface histograms (DVH/DSH) and bladder DSMs. Discrepancies between planned and daily absorbed doses were analyzed through the average of individual systematic errors, the population systematic errors and the population random errors for the DVH/DSHs and DSMs. In total, 477 DVH/DSH and 472 DSM were available. DSH and DVH showed small population systematic errors of absolute surfaces (<3.4cm(2)) and volumes (<8.4cm(3)) at the highest doses. The dose to the posterior bladder base assessed on DSMs showed a mean systematic error below 1Gy, with population systematic and random errors within 4 and 3Gy, respectively. The region surrounding this area shows higher mean systematic errors (1-3Gy), population systematic (8-11Gy) and random (5-7Gy) errors. In conclusion, DVH/DSH and DSMs are quite stable with respect to inter-fraction variations in the high-dose region, within about 2cm from bladder base. Larger systematic variations occur in the anterior portion and cranially 2.5-3.5cm from the base. Results suggest that dose predictors related to the high dose area (including the trigone dose) are likely to be sufficiently reliable with respect to the expected variations due to variable bladder filling. PMID:27053449

  20. Profile of Pacific Higher Education.

    ERIC Educational Resources Information Center

    Research and Development Cadre, Honolulu, HI.

    Comparative data concerning institutions of higher education in the Pacific Islands are tabulated and summarized to aid in program planning, development, and implementation in that region. The jurisdictions covered are: American Samoa; Palau; the Northern Mariana Islands; Micronesia; Kosrae; Pohnpei; Truk; Yap; Guam; Hawaii; and the Marshall…

  1. Arbitration in American Higher Education.

    ERIC Educational Resources Information Center

    Clark, Bob Thompson, Ed.

    Areas of concern related to grievance arbitration in higher education are examined. Selected arbitration awards, court and National Labor Relation Board rulings, and related literature are reviewed, and probable patterns and trends in arbitration are identified. Potential conflicts between collective bargaining and collegiality (self-governance)…

  2. Electronic Assessment in Higher Education

    ERIC Educational Resources Information Center

    Brink, Roelien; Lautenbach, Geoffrey

    2011-01-01

    Assessment is an important cornerstone of education. A world trend in staying abreast of the latest developments in the field of information and communication technology (ICT) has led to an increased demand for electronic assessment in education circles. The critical need and responsibility for higher education to stay on par with the latest…

  3. Student Loans for Higher Education

    ERIC Educational Resources Information Center

    Simons, Charlene Wear

    2008-01-01

    Student loans are a rapidly growing $85 billion a year industry fueled by the substantial higher economic returns associated with a college education, increased demand from students and their parents, and grant and scholarship funds that have not kept pace with rising school tuition and fees. This report describes federally subsidized and…

  4. Transnational Higher Education in Uzbekistan

    ERIC Educational Resources Information Center

    Sia, E. K.

    2014-01-01

    This paper provides an overview of transnational higher education (THE) in Uzbekistan. It includes a brief account of THE current and future market trends. The data, gathered from a literature search, show that the demand for THE (off-campus) is growing even faster than the demand for international (on-campus) programmes. This paper then provides…

  5. The Opening of Higher Education

    ERIC Educational Resources Information Center

    Matkin, Gary W.

    2012-01-01

    In a 1974 report presented to the Organisation for Economic Co-operation and Development (OECD), Martin Trow laid out a framework for understanding large-scale, worldwide changes in higher education. Trow's essay also pointed to the problems that "arise out of the transition from one phase to another in a broad pattern of development of higher…

  6. Elevating the Higher Education Beat.

    ERIC Educational Resources Information Center

    Harney, John O.

    1998-01-01

    Problems in media coverage of higher education in New England are examined, noting high turnover in journalists covering colleges and universities and journalists' lack of time to visit campuses. What coverage there is appears to be focused heavily on a few prestigious institutions and state colleges where news is easily gathered from bureaucrats…

  7. Refocusing Higher Education Budget Development.

    ERIC Educational Resources Information Center

    Illinois State Board of Higher Education, Springfield.

    This report proposes changes to the current higher education budget development process in Illinois in order to provide more information to institutions and to make the process more inclusive and open. It argues that budget development should be goal-based and accountable, responsive, incentive-based, recognize diversity of institutions, stable…

  8. Higher Ambitions Summit. Rapporteur Report

    ERIC Educational Resources Information Center

    Nash, Ian

    2014-01-01

    The Sutton Trust and Pearson two-day summit on higher ambitions in apprenticeships and vocational education drew more than 120 leaders in education, training and employment, policy makers, academics, and researchers to London. Delegates heard from political leaders stressing the importance they attach to high-quality apprenticeships. Presentations…

  9. Student Influence and Higher Education.

    ERIC Educational Resources Information Center

    Juola, Arvo E.

    Since 1965, student views and feelings have influenced great changes in higher education, sometimes to the detriment of long-term interests in academic institutions and colleges. One conspicuous recent trend is the desire of college students for more influence, impact, or power. Other prevalent attitudes may be characterized as a desire to be…

  10. Catholic Higher Education as Mission

    ERIC Educational Resources Information Center

    Lowery, Daniel

    2012-01-01

    This article uses the work of Anthony J. Gittins to reframe our understanding of Catholic higher education as mission. The broad adoption of this framework would require a common intellectual foundation, the possibility of which is dismissed by many. An accessible ontology is implied, however, in the existential analysis and theology of Karl…

  11. Gender Issues within Higher Education

    ERIC Educational Resources Information Center

    European Students' Union (NJ1), 2008

    2008-01-01

    This handbook functions as a crown on the European Students' Union's work on gender equality over the past two years. Since the establishment of the Gender Equality Committee, a lot of work has been done to improve gender equality in higher education generally, and in student unions more particularly. This handbook gathers the experiences and…

  12. Evaluating Teaching in Higher Education

    ERIC Educational Resources Information Center

    Weinberg, Bruce A.; Hashimoto, Masanori; Fleisher, Belton M.

    2009-01-01

    The authors develop an original measure of learning in higher education, based on grades in subsequent courses. Using this measure of learning, they show that student evaluations are positively related to current grades but unrelated to learning once current grades are controlled. They offer evidence that the weak relationship between learning and…

  13. Class Struggle in Higher Education

    ERIC Educational Resources Information Center

    Clawson, Dan; Leiblum, Mishy

    2008-01-01

    Public higher education has undergone a process similar to that in the national polity: a one-sided struggle by those with power to shape the institution to be more market driven, more focused on what will generate (non-state) revenues, more dominated by top administrators, and less concerned about the working class and people of color. This…

  14. A Balanced Higher Education System

    ERIC Educational Resources Information Center

    Brown, Roger

    2011-01-01

    This article explores what is meant by "a balanced higher education system". It argues that the Clarkian "triangle of coordination" (Clark, 1983) and the more recent model of Martinez and Richardson (2003) should be replaced by one that distinguishes between "self" and "collective" interests in both the academy and the wider society. Such a scheme…

  15. Higher Education's Coming Leadership Crisis

    ERIC Educational Resources Information Center

    Appadurai, Arjun

    2009-01-01

    The full impact of the current recession on American higher education remains uncertain, but drops in applications, faculty autonomy and job security, frozen salaries and hiring processes, and scaling back of new facilities and programs are already being seen. American colleges face tough times ahead for teaching, research, and capital projects…

  16. Digital Resilience in Higher Education

    ERIC Educational Resources Information Center

    Weller, Martin; Anderson, Terry

    2013-01-01

    Higher education institutions face a number of opportunities and challenges as the result of the digital revolution. The institutions perform a number of scholarship functions which can be affected by new technologies, and the desire is to retain these functions where appropriate, whilst the form they take may change. Much of the reaction to…

  17. Student Success in Higher Education

    ERIC Educational Resources Information Center

    American Federation of Teachers (NJ), 2011

    2011-01-01

    Often, campus policies and public debate on student success has been too heavily focused on standardization of curriculum and assessment and on an unacceptably flawed graduation rate formula. The report, "Student Success in Higher Education," brings the voice of front-line faculty and staff into student success policymaking to ensure that ideas…

  18. American Higher Education in Transition

    ERIC Educational Resources Information Center

    Ehrenberg, Ronald G.

    2011-01-01

    American higher education is in transition and if there ever was a "golden age" for faculty, it probably is behind us. The best historical data on the composition of faculty is collected annually by the American Mathematical Society. Between 1967 and 2009, the share of full-time faculty with PhDs remained constant at about 90 percent at doctoral…

  19. Project Management in Higher Education

    ERIC Educational Resources Information Center

    Alpert, Shannon Atkinson

    2011-01-01

    This study identified factors that influenced the use of project management in higher education research projects. Using a qualitative grounded theory approach that included in-depth interviews with assistant professors, the researcher examined how these individuals were using project management processes and tools and factors that enabled,…

  20. History of Higher Education, 1995.

    ERIC Educational Resources Information Center

    Geiger, Robert L., Ed.

    1995-01-01

    This annual compilation presents four papers on different aspects of the history of higher education in Europe and the United States. The first paper is "The Rights of Man and the Rites of Youth: Fraternity and Riot at Eighteenth Century Harvard" by Leon Jackson. This paper argues that the lines of division in the student body at…

  1. History of Higher Education, 1996.

    ERIC Educational Resources Information Center

    Geiger, Robert L., Ed.

    1996-01-01

    The four papers in this annual volume on the history of higher education cover some of the changes that evolved over the years in various U.S. institutions. The first paper is: "The Harvard Tutors: The Beginning of an Academic Profession, 1690-1825" (John D. Burton), which discusses the shift from Harvard's original tutorship model to its modern…

  2. Mobile Learning in Higher Education

    ERIC Educational Resources Information Center

    Fraga, Lucretia M.

    2012-01-01

    This mixed method research study investigated the beliefs of university faculty regarding mobile learning. As well as to determine if providing technology professional development to university faculty supports the increase of mobile learning opportunities in higher education. This study used the Beliefs About Mobile Learning Inventory (BAMLI) to…

  3. Gender Equity in Higher Education

    ERIC Educational Resources Information Center

    Washington Higher Education Coordinating Board, 2006

    2006-01-01

    Title IX of the Education Amendments of 1972 bans discrimination in schools receiving federal financial assistance with regard to both academics and athletics. The law has helped ensure that women have access to both academic and athletic opportunities at most higher education institutions in the United States, dramatically increasing the range…

  4. Higher Education Profiles & Trends 2013

    ERIC Educational Resources Information Center

    Tennessee Higher Education Commission, 2013

    2013-01-01

    The statute [T.C.A. Section 49-7-202(c)(7)] requires the Tennessee Higher Education Commission to prepare a biennial report for the governor and the general assembly, "commenting upon major developments, trends, new policies, budgets and financial considerations which in the judgment of the commission will be useful to the governor and to the…

  5. The Battle for Higher Standards

    ERIC Educational Resources Information Center

    Luna, Tom; Rush, Mike; Gramer, Rod; Stewart, Roger

    2014-01-01

    To remain internationally competitive, states needed clearer, higher, and comparable K-12 learning standards aligned with college and career expectations, and as ambitious as those of the countries that lead the world in education. Idaho's old academic standards were not preparing students for postsecondary education, which contributed to the…

  6. American Higher Education in Decline.

    ERIC Educational Resources Information Center

    Ashworth, Kenneth H.

    The decline in the quality of American higher education over the past several decades and the ramifications of this phenomena are discussed in this book. It is suggested that in responding to modern egalitarianism and the need to attract students, colleges and universities have initiated innovative programs, noncampuses, and nontraditional degrees…

  7. On Education: The Higher Education.

    ERIC Educational Resources Information Center

    West, Thomas G.

    1980-01-01

    Higher education is described as a name for the highest formation of soul and mind, and the highest goal of education is "wisdom." Practical wisdom and theoretical wisdom are seen as exemplified at their peak in the comprehension of the genuine statesman and the genuine philosopher. (MLW)

  8. Higher Education Evaluation in Germany

    ERIC Educational Resources Information Center

    Schmidt, Bernhard; von Hippel, Aiga; Tippelt, Rudolf

    2010-01-01

    Quality assurance in the area of higher education has become a central issue among both politicians and scientists. University evaluations which refer to both research and teaching are an important element of quality assurance. The present contribution starts out by determining the different components of quality at universities according to…

  9. Danger: Work on Higher Levels.

    ERIC Educational Resources Information Center

    Lapointe, Archie E.

    The Assessment Policy Committee of the National Assessment of Educational Progress (NAEP) has directed the NAEP staff to focus the 1985-86 Assessments of Reading, Mathematics, Science, and Computer Competence on the higher-order skills. Each Learning Area Committee worked independently developing three-dimensional models. These defined what could…

  10. Higher Education: Building Connecticut's Workforce

    ERIC Educational Resources Information Center

    DeLisa, Cynthia L.; Placzek, Dana W.

    2004-01-01

    The Connecticut Departments of Labor (DOL) and Higher Education (DHE), working in close collaboration with the University of Connecticut, Connecticut State University, Connecticut Community Colleges and Charter Oak State College, present this comprehensive report on employment outcomes for graduates of the State's public college system. This…

  11. Higher Education and the Law.

    ERIC Educational Resources Information Center

    Edwards, Harry T.; Nordin, Virginia Davis

    The proliferation of laws, regulations, and judicial opinions affecting higher education and the nature of the impact of these laws on the academic community are examined. Designed for use by both students and practitioners, the book employs the "case method" design based on the belief that law cases furnish the best sources for study and review…

  12. Epistemological Development in Higher Education

    ERIC Educational Resources Information Center

    Richardson, John T. E.

    2013-01-01

    Research has been carried out on students' epistemological development in higher education for at least 50 years. Researchers on both sides of the Atlantic have converged on accounts that describe students' epistemological development in terms of a sequence or hierarchy of qualitatively distinct stages or positions. The rich qualitative data…

  13. Social Stratification in Higher Education

    ERIC Educational Resources Information Center

    Grodsky, Eric; Jackson, Erika

    2009-01-01

    Background/Context: Over the past half century, scholars in a variety of fields have contributed to our understanding of the relationship between higher education and social stratification. We review this literature, highlighting complementarities and inconsistencies. Purpose/Objective/Research Question/Focus of Study: We situate our review of the…

  14. Internal Audit in Higher Education.

    ERIC Educational Resources Information Center

    Holmes, Alison, Ed.; Brown, Sally, Ed.

    This book describes a range of examples of internal audit in higher education as part of a process of the exchange of good practice. The book recognizes well-established links with audit theory from other contexts and makes use of theoretical perspectives explored in the financial sector. The chapters are: (1) "Quality Audit Issues" (Sally Brown…

  15. Disability Discrimination in Higher Education.

    ERIC Educational Resources Information Center

    Weber, Mark C.

    2002-01-01

    Reviews developments in 2000 in the law of disability discrimination as it relates to higher education, which falls into five categories: (1) definition of a qualified individual; (2) accommodations, access, undue burden, and fundamental alteration of programs; (3) intentional discrimination, harassment, and retaliation; (4) Eleventh Amendment…

  16. Employment Discrimination in Higher Education.

    ERIC Educational Resources Information Center

    Hustoles, Thomas P.; Griffin, Oren R.

    2000-01-01

    Reviews court decisions related to employment discrimination in higher education. The most significant development was a series of cases affirming that Eleventh Amendment immunity from private money damage claims brought pursuant to various federal employment discrimination statutes applied to state colleges and universities. (SLD)

  17. Disability Discrimination in Higher Education.

    ERIC Educational Resources Information Center

    Weber, Mark C.

    2000-01-01

    Reviews court cases in 1999 related to disability discrimination in higher education focusing on the Americans with Disabilities Act and section 504 of the Rehabilitation Act of 1973. The "Garrett" case regarding Eleventh Amendment immunity is the case most likely to be significant in the development of the law of disability discrimination. (SLD)

  18. Higher Education and European Regionalism.

    ERIC Educational Resources Information Center

    Paterson, Lindsay

    2001-01-01

    Speculates about the relationship between two fundamental social changes occurring in Europe: the development of a mass higher education system and the slow decay of the old states that were inherited from the 19th century, eroded from below by various movements for national and regional autonomy, and eroded from above by the growing power and…

  19. Academic Rewards in Higher Education.

    ERIC Educational Resources Information Center

    Lewis, Darrel R., Ed.; Becker, William E., Jr., Ed.

    A colloquium series in higher education at the University of Minnesota in the fall and winter of 1977-1978 examined the influence of academic reward systems on faculty behavior and academic productivity. These essays are the collective results of their findings and recommendations. Essays include: "Perspectives from Psychology: Financial…

  20. Collective Bargaining in Higher Education.

    ERIC Educational Resources Information Center

    Mannix, Thomas M., Ed.

    The 1975 conference of the National Center for the Study of Collective Bargaining in Higher Education covered a wide range of topics. The proceedings included discussion of such areas as collective bargaining's impact on governance; the U.S. Congress and public employee legislation; federal legislation from a management perspective and from a…

  1. Women in Higher Education, 1997.

    ERIC Educational Resources Information Center

    Wenniger, Mary Dee, Ed.

    1997-01-01

    The 12 issues of this newsletter focus on issues concerned with women students, faculty, and administrators in higher education. Each issue includes feature articles, news items, and profiles of significant people. The issues' main articles address: women in athletics; leadership development for women; the first year in academic administration;…

  2. Faculty Retention in Higher Education

    ERIC Educational Resources Information Center

    Soomro, Tariq Rahim; Ahmad, Reyaz

    2013-01-01

    Criteria for retaining or firing a highly qualified faculty in higher education in many cases are vague and unclear. This situation is neither a comfortable, nor a healthy, both for the faculty and the administration. Stakeholders have enough reason to blame each other in the absence of transparent mechanism. This paper proposes a transparent…

  3. Higher Education in American Society.

    ERIC Educational Resources Information Center

    Altbach, Philip G., Ed.; Berdahl, Robert O., Ed.

    The wide-ranging impact of social, political and economic forces on higher education and their specific consequences for faculty, students, and administrators is addressed within the broad context of autonomy and accountability. The book is organized around several themes. The first section discusses such basic issues as: the historical…

  4. State Budgeting for Higher Education.

    ERIC Educational Resources Information Center

    Glenny, Lyman A.

    1976-01-01

    State government is and is expected to remain the chief source of funding for higher education. At the same time, the state is confronted with serious policy issues relating to support of research, public services, and adult education, to falling enrollments in some public institutions, to the probable closure of some private liberal arts colleges…

  5. Systems Applications in Higher Education.

    ERIC Educational Resources Information Center

    Schure, Alexander

    This paper discusses the application of computers for higher education and describes a philosophy and initial application of an accountability system that can aid in coping with the problems of occupationally related schools. Discussed are: (1) the role of computers in systems application; (2) the need for systems related information: the…

  6. Disability Studies in Higher Education

    ERIC Educational Resources Information Center

    Taylor, Steven J.

    2011-01-01

    As a topic of study, disability is not new at institutions of higher education. Psychological and intellectual disabilities have been of interest in psychiatry and psychology at least since the late 1800s and early 1900s. The post-World War II era, in particular, witnessed the rapid expansion of academic programs in special education, vocational…

  7. Higher Education as Virtual Conversation

    ERIC Educational Resources Information Center

    Robbins-Bell, Sarah

    2008-01-01

    Whether or not it is an accurate portrayal, the old stereotype of higher education is the lecture hall, where students sit passively and take notes from a wise professor whose experience and knowledge can be shared only in the classroom. The professor's role is to dispense information, and the students' role is to receive it. However idealistic…

  8. Supercomplexity in Higher Education Kinesiology

    ERIC Educational Resources Information Center

    Block, Betty A.; Estes, Steve

    2011-01-01

    This article employs Barnett's (2004) specifications of the aspects that describe the times of "supercomplexity." This term characterizes the challenges universities are facing regarding the expanding and competing forces that are affecting higher education, particularly in the West. Outside forces related to globalization, digital technologies,…

  9. Higher Education for Our Time

    ERIC Educational Resources Information Center

    Burnett, Dana D.; Collins, Natalia D.

    2010-01-01

    Public higher education is currently experiencing a decline in financial support from state governments, an acceleration of enrollment growth, and a shift from a transformational to a transactional student relationship. Private institutions are also struggling with increasing operational costs, and decreases in revenue from endowments and…

  10. Fiscal Issues in Higher Education.

    ERIC Educational Resources Information Center

    Rigolot, Carol, Ed.

    Forty colleges and life insurance presidents met to discuss key historical and contemporary factors influencing fiscal management in higher education, including inflation, salaries, diminishing enrollment figures, energy costs, federal regulations and the increasing cost of research. Differences and similarities between business and academia were…

  11. Women in Higher Education Management.

    ERIC Educational Resources Information Center

    Commonwealth Secretariat, London (England).

    This volume contains 11 papers on the under-representation of women in higher education management in Bahrain, Finland, France, India, Indonesia, Malaysia, Nigeria, Peru, the United States and Canada, the South Pacific and the West Indies. All papers were written by women vice-chancellors, presidents and senior managers of universities in those…

  12. Customer Service in Higher Education.

    ERIC Educational Resources Information Center

    Sines, Robert G., Jr.; Duckworth, Eric A.

    1994-01-01

    It is argued that colleges and universities need to understand the importance of customer service in student retention, particularly in a competitive marketplace. Customer service concepts that work in the private sector are seen as useful in higher education, and a model is proposed. (MSE)

  13. Art in American Higher Institutions.

    ERIC Educational Resources Information Center

    Feldman, Edmund Burke, Ed.

    This volume of 11 articles contains a comprehensive statement about the visual arts as they are encountered in post-secondary education. The articles are: (1) "Art and the Liberal Arts: A Trivial, Artificial, Irrelevant Antagonism" by Albert Bush-Brown; (2) "The Arts in Higher Education: A Question of Priorities" by Lawrence Dennis; (3) "Access to…

  14. Today's Higher Education IT Workforce

    ERIC Educational Resources Information Center

    Bichsel, Jacqueline

    2014-01-01

    The professionals making up the current higher education IT workforce have been asked to adjust to a culture of increased IT consumerization, more sourcing options, broader interest in IT's transformative potential, and decreased resources. Disruptions that include the bring-your-own-everything era, cloud computing, new management practices,…

  15. 2011 Higher Education Sustainability Review

    ERIC Educational Resources Information Center

    Wagner, Margo, Ed.

    2012-01-01

    Looking through the lens of AASHE Bulletin stories in 2011, this year's review reveals an increased focus on higher education access, affordability, and success; more green building efforts than ever before; and growing campus-community engagement on food security, among many other achievements. Contributors include James Applegate (Lumina…

  16. Stakeholder Relationships in Higher Education

    ERIC Educational Resources Information Center

    Kettunen, Juha

    2015-01-01

    The purpose of this study is to develop a stakeholder map to describe the most important stakeholders and the process of stakeholder relationships in higher education. According to the perspective of the balanced scorecard, the classification of stakeholders integrates stakeholders into strategic management. Stakeholder maps are essential in…

  17. Simulation Models in Higher Education.

    ERIC Educational Resources Information Center

    Morrisseau, James J.

    1973-01-01

    This paper, adapted from a Society for College and University Planning conference, discusses cost simulation models in higher education. Emphasis is placed on the art of management, mini-models vs. maxi-models, the useful model, the reporting problem, anatomy of failure, information vs. action, and words of caution. (MJM)

  18. Collective Bargaining in Higher Education.

    ERIC Educational Resources Information Center

    Soberman, Daniel A.; And Others

    Papers are presented from a seminar on collective bargaining in higher education sponsored by the Center for Educational Management Studies of the University of Hawaii. The seminar was designed to address the similarities and differences among various countries and to draw on the experiences of Canada and Europe as they may relate to collective…

  19. Rethinking Higher Education Capital Finance.

    ERIC Educational Resources Information Center

    King, George A.

    1988-01-01

    Capital finance in institutions of higher education is analyzed in light of changes in the Tax Reform Act of 1986 affecting the ability of institutions to finance capital projects and the likelihood of changes in the government's view of tax-exempt financing. The options for colleges and universities are analyzed in the following areas: (1)…

  20. Institutionalizing Diversity: Transforming Higher Education

    ERIC Educational Resources Information Center

    McRae-Yates, Velda

    2009-01-01

    This case study examines plausible efforts to institutionalize diversity in a higher education setting so it becomes part of the strategic mission, and permeates the interactions, discussions, and operations. Review of literature, surveys, and in-depth interviews are conducted at a Massachusetts institution to gather information from faculty,…

  1. Sustainability: Higher Education's New Fundamentalism

    ERIC Educational Resources Information Center

    Peterson, Rachelle; Wood, Peter W.

    2015-01-01

    "Sustainability" is a key idea on college campuses in the United States and the rest of the Western world. To the unsuspecting, sustainability is just a new name for environmentalism. This report is the first in-depth critical study of the sustainability movement in higher education. The focus of this study is on how the sustainability…

  2. Diabetes is Associated with Higher Trimethylamine N-oxide Plasma Levels.

    PubMed

    Dambrova, M; Latkovskis, G; Kuka, J; Strele, I; Konrade, I; Grinberga, S; Hartmane, D; Pugovics, O; Erglis, A; Liepinsh, E

    2016-04-01

    Recent studies have revealed strong associations between systemic trimethylamine N-oxide (TMAO) levels, atherosclerosis and cardiovascular risk. In addition, plasma L-carnitine levels in patients with high TMAO concentrations predicted an increased risk for cardiovascular disease and incident major adverse cardiac events. The aim of the present study was to investigate the relation between TMAO and L-carnitine plasma levels and diabetes. Blood plasma samples were collected from 12 and 20 weeks old db/db mice and patients undergoing percutaneous coronary intervention. Diabetic compared to non-diabetic db/L mice presented 10-fold higher TMAO, but lower L-carnitine plasma concentrations at 12 weeks of age. After 8 weeks of observation, diabetic db/db mice had significantly increased body weight, insulin resistance and TMAO concentration in comparison to non-diabetic control. In 191 patients undergoing percutaneous coronary intervention the median (interquartile range) plasma concentration of TMAO was 1.8 (1.2-2.6) µmol/L. Analysis of the samples showed a bivariate association of TMAO level with age, total cholesterol and L-carnitine. The multivariate linear regression analysis revealed that, in addition to L-carnitine as the strongest predictor of log transformed TMAO (p<0.001), the parameters of age, diabetes status and body mass index (BMI) were independently associated with increased log transformed TMAO levels (p<0.01).Our data provide evidence that age, diabetes and BMI are associated with higher TMAO levels independently of L-carnitine. These data support the hypothesis of TMAO as a cardiovascular risk marker and warrant further investigation of TMAO for diabetes research applications. PMID:27123785

  3. Application of higher order spectral features and support vector machines for bearing faults classification.

    PubMed

    Saidi, Lotfi; Ben Ali, Jaouher; Fnaiech, Farhat

    2015-01-01

    Condition monitoring and fault diagnosis of rolling element bearings timely and accurately are very important to ensure the reliability of rotating machinery. This paper presents a novel pattern classification approach for bearings diagnostics, which combines the higher order spectra analysis features and support vector machine classifier. The use of non-linear features motivated by the higher order spectra has been reported to be a promising approach to analyze the non-linear and non-Gaussian characteristics of the mechanical vibration signals. The vibration bi-spectrum (third order spectrum) patterns are extracted as the feature vectors presenting different bearing faults. The extracted bi-spectrum features are subjected to principal component analysis for dimensionality reduction. These principal components were fed to support vector machine to distinguish four kinds of bearing faults covering different levels of severity for each fault type, which were measured in the experimental test bench running under different working conditions. In order to find the optimal parameters for the multi-class support vector machine model, a grid-search method in combination with 10-fold cross-validation has been used. Based on the correct classification of bearing patterns in the test set, in each fold the performance measures are computed. The average of these performance measures is computed to report the overall performance of the support vector machine classifier. In addition, in fault detection problems, the performance of a detection algorithm usually depends on the trade-off between robustness and sensitivity. The sensitivity and robustness of the proposed method are explored by running a series of experiments. A receiver operating characteristic (ROC) curve made the results more convincing. The results indicated that the proposed method can reliably identify different fault patterns of rolling element bearings based on vibration signals. PMID:25282095

  4. Pharmacokinetics of zidovudine dosed twice daily according to World Health Organization weight bands in Ugandan HIV-infected children.

    PubMed

    Fillekes, Quirine; Kendall, Lindsay; Kitaka, Sabrina; Mugyenyi, Peter; Musoke, Philippa; Ndigendawani, Milly; Bwakura-Dangarembizi, Mutsa; Gibb, Diana M; Burger, David; Walker, Ann Sarah

    2014-05-01

    Data on zidovudine pharmacokinetics in children dosed using World Health Organization weight bands are limited. About 45 HIV-infected, Ugandan children, 3.4 (2.6-6.2) years, had intensive pharmacokinetic sampling. Geometric mean zidovudine AUC0-12h was 3.0 h.mg/L, which is higher than previously observed in adults, and was independently higher in those receiving higher doses, younger and underweight children. Higher exposure was also marginally associated with lower hemoglobin. PMID:24736440

  5. Extremal higher spin black holes

    NASA Astrophysics Data System (ADS)

    Bañados, Máximo; Castro, Alejandra; Faraggi, Alberto; Jottar, Juan I.

    2016-04-01

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3 d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require supersymmetry, we exemplify its consequences in the context of sl(3|2) ⊕ sl(3|2) Chern-Simons theory and show that, as usual, not all extremal solutions preserve supersymmetries. Remarkably, we find in addition that the higher spin setup allows for non-extremal supersymmetric black hole solutions. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) ⊕ sl(3|2) Chern-Simons theory and two-dimensional CFTs with W (3|2) symmetry, the simplest higher spin extension of the N = 2 super-Virasoro algebra. In particular, we compute W (3|2) BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3 d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N = 2 two-dimensional CFTs with extended symmetry algebras.

  6. Dose reconstruction using mobile phones.

    PubMed

    Beerten, K; Reekmans, F; Schroeyers, W; Lievens, L; Vanhavere, F

    2011-03-01

    Electronic components inside mobile phones are regarded as useful tools for accident and retrospective dosimetry using optically stimulated luminescence (OSL) and thermoluminescence. Components inside the devices with suitable properties for luminescence dosimetry include, amongst others, ceramic substrates in resistors, capacitors, transistors and antenna switches. Checking the performance of such devices in dosimetric experiments is a crucial step towards developing a reliable dosimetry system for emergency situations using personal belongings. Here, the results of dose assessment experiments using irradiated mobile phones are reported. It will be shown that simple regenerative dose estimates, derived from various types of components removed from different mobile phone models, are consistent with the given dose, after applying an average fading correction factor. PMID:21062806

  7. Parameterization of solar flare dose

    SciTech Connect

    Lamarche, A.H.; Poston, J.W.

    1996-12-31

    A critical aspect of missions to the moon or Mars will be the safety and health of the crew. Radiation in space is a hazard for astronauts, especially high-energy radiation following certain types of solar flares. A solar flare event can be very dangerous if astronauts are not adequately shielded because flares can deliver a very high dose in a short period of time. The goal of this research was to parameterize solar flare dose as a function of time to see if it was possible to predict solar flare occurrence, thus providing a warning time. This would allow astronauts to take corrective action and avoid receiving a dose greater than the recommended limit set by the National Council on Radiation Protection and Measurements (NCRP).

  8. Radiation Dose from Reentrant Electrons

    NASA Technical Reports Server (NTRS)

    Badhwar, G.D.; Cleghorn, T. E.; Watts, J.

    2003-01-01

    In estimating the crew exposures during an EVA, the contribution of reentrant electrons has always been neglected. Although the flux of these electrons is small compared to the flux of trapped electrons, their energy spectrum extends to several GeV compared to about 7 MeV for trapped electrons. This is also true of splash electrons. Using the measured reentrant electron energy spectra, it is shown that the dose contribution of these electrons to the blood forming organs (BFO) is more than 10 times greater than that from the trapped electrons. The calculations also show that the dose-depth response is a very slowly changing function of depth, and thus adding reasonable amounts of additional shielding would not significantly lower the dose to BFO.

  9. WE-A-17A-12: The Influence of Eye Plaque Design On Dose Distributions and Dose- Volume Histograms

    SciTech Connect

    Aryal, P; Molloy, JA; Rivard, MJ

    2014-06-15

    Purpose: To investigate the effect of slot design of the model EP917 plaque on dose distributions and dose-volume histograms (DVHs). Methods: The dimensions and orientation of the slots in EP917 plaques were measured. In the MCNP5 radiation simulation geometry, dose distributions on orthogonal planes and DVHs for a tumor and sclera were generated for comparisons. 27 slot designs and 13 plaques were evaluated and compared with the published literature and the Plaque Simulator clinical treatment planning system. Results: The dosimetric effect of the gold backing composition and mass density was < 3%. Slot depth, width, and length changed the central axis (CAX) dose distributions by < 1% per 0.1 mm in design variation. Seed shifts in the slot towards the eye and shifts of the {sup 125} I-coated Ag rod within the capsule had the greatest impact on CAX dose distribution, increasing by 14%, 9%, 4%, and 2.5% at 1, 2, 5, and 10 mm, respectively, from the inner sclera. Along the CAX, dose from the full plaque geometry using the measured slot design was 3.4% ± 2.3% higher than the manufacturer-provided geometry. D{sub 10} for the simulated tumor, inner sclera, and outer sclera for the measured plaque was also higher, but 9%, 10%, and 20%, respectively. In comparison to the measured plaque design, a theoretical plaque having narrow and deep slots delivered 30%, 37%, and 62% lower D{sub 10} doses to the tumor, inner sclera, and outer sclera, respectively. CAX doses at −1, 0, 1, and 2 mm were also lower by a factor of 2.6, 1.4, 1.23, and 1.13, respectively. Conclusion: The study identified substantial sensitivity of the EP917 plaque dose distributions to slot design. However, it did not identify substantial dosimetric variations based on radionuclide choice ({sup 125}I, {sup 103}Pd, or {sup 131}Cs). COMS plaques provided lower scleral doses with similar tumor dose coverage.

  10. A simplified technique for delivering total body irradiation (TBI) with improved dose homogeneity

    SciTech Connect

    Yao Rui; Bernard, Damian; Turian, Julius; Abrams, Ross A.; Sensakovic, William; Fung, Henry C.; Chu, James C. H.

    2012-04-15

    Purpose: Total body irradiation (TBI) with megavoltage photon beams has been accepted as an important component of management for a number of hematologic malignancies, generally as part of bone marrow conditioning regimens. The purpose of this paper is to present and discuss the authors' TBI technique, which both simplifies the treatment process and improves the treatment quality. Methods: An AP/PA TBI treatment technique to produce uniform dose distributions using sequential collimator reductions during each fraction was implemented, and a sample calculation worksheet is presented. Using this methodology, the dosimetric characteristics of both 6 and 18 MV photon beams, including lung dose under cerrobend blocks was investigated. A method of estimating midplane lung doses based on measured entrance and exit doses was proposed, and the estimated results were compared with measurements. Results: Whole body midplane dose uniformity of {+-}10% was achieved with no more than two collimator-based beam modulations. The proposed model predicted midplane lung doses 5% to 10% higher than the measured doses for 6 and 18 MV beams. The estimated total midplane doses were within {+-}5% of the prescribed midplane dose on average except for the lungs where the doses were 6% to 10% lower than the prescribed dose on average. Conclusions: The proposed TBI technique can achieve dose uniformity within {+-}10%. This technique is easy to implement and does not require complicated dosimetry and/or compensators.

  11. A comparison of quantum limited dose and noise equivalent dose

    NASA Astrophysics Data System (ADS)

    Job, Isaias D.; Boyce, Sarah J.; Petrillo, Michael J.; Zhou, Kungang

    2016-03-01

    Quantum-limited-dose (QLD) and noise-equivalent-dose (NED) are performance metrics often used interchangeably. Although the metrics are related, they are not equivalent unless the treatment of electronic noise is carefully considered. These metrics are increasingly important to properly characterize the low-dose performance of flat panel detectors (FPDs). A system can be said to be quantum-limited when the Signal-to-noise-ratio (SNR) is proportional to the square-root of x-ray exposure. Recent experiments utilizing three methods to determine the quantum-limited dose range yielded inconsistent results. To investigate the deviation in results, generalized analytical equations are developed to model the image processing and analysis of each method. We test the generalized expression for both radiographic and fluoroscopic detectors. The resulting analysis shows that total noise content of the images processed by each method are inherently different based on their readout scheme. Finally, it will be shown that the NED is equivalent to the instrumentation-noise-equivalent-exposure (INEE) and furthermore that the NED is derived from the quantum-noise-only method of determining QLD. Future investigations will measure quantum-limited performance of radiographic panels with a modified readout scheme to allow for noise improvements similar to measurements performed with fluoroscopic detectors.

  12. Evaluation of radiation dose to neonates in a special care baby unit

    NASA Astrophysics Data System (ADS)

    Alzimami, K.; Sulieman, A.; Yousif, A.; Babikir, E.; Salih, I.

    2014-11-01

    The purpose of this study was to evaluate the patient entrance surface dose (ESD), organ dose and effective dose for neonates in the special care baby unit (SCBU) up to 28 days after birth. A total of 135 patients were examined during 4 months. ESDs were calculated from patient exposure parameters using DosCal software. Effective doses were calculated using software from the National Radiological Protection Board (NRPB). The mean patient ESD per procedure was 80±0.02 μGy. The mean and range of the effective dose per procedure were 0.02 (0.01-0.3) mSv. The radiation dose in this study was higher compared to previous studies. A dedicated X-ray machine with additional filtration is recommended for patient dose reductions.

  13. Dose Response of MARV/Angola Infection in Cynomolgus Macaques following IM or Aerosol Exposure

    PubMed Central

    Johnston, Sara C.; Lin, Kenny L.; Twenhafel, Nancy A.; Raymond, Jo Lynne W.; Shamblin, Joshua D.; Wollen, Suzanne E.; Wlazlowski, Carly B.; Wilkinson, Eric R.; Botto, Miriam A.; Goff, Arthur J.

    2015-01-01

    Marburg virus infection in humans causes a hemorrhagic disease with a high case fatality rate. Countermeasure development requires the use of well-characterized animal models that mimic human disease. To further characterize the cynomolgus macaque model of MARV/Angola, two independent dose response studies were performed using the intramuscular or aerosol routes of exposure. All animals succumbed at the lowest target dose; therefore, a dose effect could not be determined. For intramuscular-exposed animals, 100 PFU was the first target dose that was not significantly different than higher target doses in terms of time to disposition, clinical pathology, and histopathology. Although a significant difference was not observed between aerosol-exposed animals in the 10 PFU and 100 PFU target dose groups, 100 PFU was determined to be the lowest target dose that could be consistently obtained and accurately titrated in aerosol studies. PMID:26413900

  14. NIRS external dose estimation system for Fukushima residents after the Fukushima Dai-ichi NPP accident

    PubMed Central

    Akahane, Keiichi; Yonai, Shunsuke; Fukuda, Shigekazu; Miyahara, Nobuyuki; Yasuda, Hiroshi; Iwaoka, Kazuki; Matsumoto, Masaki; Fukumura, Akifumi; Akashi, Makoto

    2013-01-01

    The great east Japan earthquake and subsequent tsunamis caused Fukushima Dai-ichi Nuclear Power Plant (NPP) accident. National Institute of Radiological Sciences (NIRS) developed the external dose estimation system for Fukushima residents. The system is being used in the Fukushima health management survey. The doses can be obtained by superimposing the behavior data of the residents on the dose rate maps. For grasping the doses, 18 evacuation patterns of the residents were assumed by considering the actual evacuation information before using the survey data. The doses of the residents from the deliberate evacuation area were relatively higher than those from the area within 20 km radius. The estimated doses varied from around 1 to 6 mSv for the residents evacuated from the representative places in the deliberate evacuation area. The maximum dose in 18 evacuation patterns was estimated to be 19 mSv. PMID:23591638

  15. Pediatric organ dose measurements in axial and helical multislice CT

    SciTech Connect

    McDermott, Alanna; White, R. Allen; Mc-Nitt-Gray, Mike; Angel, Erin; Cody, Dianna

    2009-05-15

    An anthropomorphic pediatric phantom (5-yr-old equivalent) was used to determine organ doses at specific surface and internal locations resulting from computed tomography (CT) scans. This phantom contains four different tissue-equivalent materials: Soft tissue, bone, brain, and lung. It was imaged on a 64-channel CT scanner with three head protocols (one contiguous axial scan and two helical scans [pitch=0.516 and 0.984]) and four chest protocols (one contiguous axial scan and three helical scans [pitch=0.516, 0.984, and 1.375]). Effective mA s [=(tube currentxrotation time)/pitch] was kept nearly constant at 200 effective mA s for head and 290 effective mA s for chest protocols. Dose measurements were acquired using thermoluminescent dosimeter powder in capsules placed at locations internal to the phantom and on the phantom surface. The organs of interest were the brain, both eyes, thyroid, sternum, both breasts, and both lungs. The organ dose measurements from helical scans were lower than for contiguous axial scans by 0% to 25% even after adjusting for equivalent effective mA s. There was no significant difference (p>0.05) in organ dose values between the 0.516 and 0.984 pitch values for both head and chest scans. The chest organ dose measurements obtained at a pitch of 1.375 were significantly higher than the dose values obtained at the other helical pitches used for chest scans (p<0.05). This difference was attributed to the automatic selection of the large focal spot due to a higher tube current value. These findings suggest that there may be a previously unsuspected radiation dose benefit associated with the use of helical scan mode during computed tomography scanning.

  16. Pediatric organ dose measurements in axial and helical multislice CT

    PubMed Central

    McDermott, Alanna; White, R. Allen; Mc-Nitt-Gray, Mike; Angel, Erin; Cody, Dianna

    2009-01-01

    An anthropomorphic pediatric phantom (5-yr-old equivalent) was used to determine organ doses at specific surface and internal locations resulting from computed tomography (CT) scans. This phantom contains four different tissue-equivalent materials: Soft tissue, bone, brain, and lung. It was imaged on a 64-channel CT scanner with three head protocols (one contiguous axial scan and two helical scans [pitch=0.516 and 0.984]) and four chest protocols (one contiguous axial scan and three helical scans [pitch=0.516, 0.984, and 1.375]). Effective mA s [=(tube current×rotation time)∕pitch] was kept nearly constant at 200 effective mA s for head and 290 effective mA s for chest protocols. Dose measurements were acquired using thermoluminescent dosimeter powder in capsules placed at locations internal to the phantom and on the phantom surface. The organs of interest were the brain, both eyes, thyroid, sternum, both breasts, and both lungs. The organ dose measurements from helical scans were lower than for contiguous axial scans by 0% to 25% even after adjusting for equivalent effective mA s. There was no significant difference (p>0.05) in organ dose values between the 0.516 and 0.984 pitch values for both head and chest scans. The chest organ dose measurements obtained at a pitch of 1.375 were significantly higher than the dose values obtained at the other helical pitches used for chest scans (p<0.05). This difference was attributed to the automatic selection of the large focal spot due to a higher tube current value. These findings suggest that there may be a previously unsuspected radiation dose benefit associated with the use of helical scan mode during computed tomography scanning. PMID:19544765

  17. Sievert, gray and dose equivalent.

    PubMed

    Pfalzner, P M

    1983-12-01

    The concepts of physical quantity and physical units of measurement are presented. The relations between quantities, the names and symbols for SI (International System) base units, derived units and special names of SI units are illustrated. From the definition of the radiation quantity dose equivalent, the SI unit for this quantity is shown to be dimensionally identical with the joule per kilogram. The sievert (Sv) is the special (restricted) name for the SI unit of the quantity dose equivalent, with 1 Sv = 1 J/kg. PMID:6668293

  18. EDITORIAL: Deeper, broader, higher, better?

    NASA Astrophysics Data System (ADS)

    Dobson, Ken

    1998-07-01

    Honorary Editor The standard of educational achievement in England and Wales is frequently criticized, and it seems to be an axiom of government that schools and teachers need to be shaken up, kept on a tight rein, copiously inspected, shamed and blamed as required: in general, subjected to the good old approach of: ' Find out what Johnny is doing and tell him to stop.' About the only exception to this somewhat severe attitude is at A-level, where the standard is simply golden. Often, comparisons are made between the performance of, say, English children and that of their coevals in other countries, with different customs, systems, aims and languages. But there has been a recent comparison of standards at A-level with a non-A-level system of pre-university education, in an English-speaking country that both sends students to English universities and accepts theirs into its own, and is, indeed, represented in the UK government at well above the level expected from its ethnical weighting in the population. This semi-foreign country is Scotland. The conclusions of the study are interesting. Scotland has had its own educational system, with `traditional breadth', and managed to escape much of the centralized authoritarianism that we have been through south of the border. It is interesting to note that, while for the past dozen years or so the trend in A-level Physics entries has been downwards, there has been an increase in the take-up of Scottish `Highers'. Highers is a one-year course. Is its popularity due to its being easier than A-level? Scottish students keen enough to do more can move on to the Certificate of Sixth Year Studies, and will shortly be able to upgrade a Higher Level into an Advanced Higher Level. A comparability study [ Comparability Study of Scottish Qualifications and GCE Advanced Levels: Report on Physics January 1998 (free from SQA)] was carried out by the Scottish Qualifications Authority (SQA) with the aim (amongst others) of helping

  19. Doses to patients from dental radiology in France

    SciTech Connect

    Benedittini, M.; Maccia, C.; Lefaure, C.; Fagnani, F. )

    1989-06-01

    In France, a national study was undertaken to estimate both dental radiology practices (equipment and activity) and the associated population collective dose. This study was done in two steps: A nationwide survey was conducted on the practitioner categories involved in dental radiology, and dosimetric measurements were performed on patients and on an anthropomorphic phantom by using conventional dental x-ray machines and pantomographic units. A total of 27.5 x 10(6) films were estimated to have been performed in 1984; 6% of them were pantomographic and 94% were conventional. Most of the organ doses measured for one intra-oral film were lower than 1 mGy (100 mrad); pantomogram dose values were generally higher than intra-oral ones. The collective effective dose equivalent figure was 2,000 person-Sv (2 x 10(5) person rem) leading to a per head dose equivalent of 0.037 mSv (3.7 mrem). The study allowed authors to identify ways to reduce the patient dose in France (e.g., implementing the use of long cone devices and controlling darkroom practices).

  20. The role of dose reduction with NSAID use.

    PubMed

    Matthews, Michele L

    2013-11-01

    Effective pain relief with use of nonsteroidal anti-inflammatory drugs (NSAIDs) may come at the cost of an increased risk for serious cardiovascular (CV), gastrointestinal (GI), and renal complications. Research has shown that these adverse events are more likely to occur with higher NSAID dosing and in individuals with a preexisting risk for CV and GI complications. To minimize the potential risk for an adverse event, numerous regulatory bodies and medical societies recommend using the lowest effective NSAID dose for the shortest time necessary. One potential strategy is to offer patients lower doses of standard NSAID formulations. However, efforts to modify physician prescribing behavior may be challenging because of concerns regarding the potential for suboptimal pain management. Another strategy has emerged through use of new technology that produces submicron NSAID formulations. This new technology is also an approach that could provide effective pain relief at low doses. This article reviews the role of dose and duration in the risk for NSAID-associated adverse events, and discusses the potential benefits associated with new low-dose submicron NSAID formulations. PMID:24494606

  1. SU-E-T-313: The Accuracy of the Acuros XB Advanced Dose Calculation Algorithm for IMRT Dose Distributions in Head and Neck

    SciTech Connect

    Araki, F; Onizuka, R; Ohno, T; Tomiyama, Y; Hioki, K

    2014-06-01

    Purpose: To investigate the accuracy of the Acuros XB version 11 (AXB11) advanced dose calculation algorithm by comparing with Monte Caro (MC) calculations. The comparisons were performed with dose distributions for a virtual inhomogeneity phantom and intensity-modulated radiotherapy (IMRT) in head and neck. Methods: Recently, AXB based on Linear Boltzmann Transport Equation has been installed in the Eclipse treatment planning system (Varian Medical Oncology System, USA). The dose calculation accuracy of AXB11 was tested by the EGSnrc-MC calculations. In additions, AXB version 10 (AXB10) and Analytical Anisotropic Algorithm (AAA) were also used. First the accuracy of an inhomogeneity correction for AXB and AAA algorithms was evaluated by comparing with MC-calculated dose distributions for a virtual inhomogeneity phantom that includes water, bone, air, adipose, muscle, and aluminum. Next the IMRT dose distributions for head and neck were compared with the AXB and AAA algorithms and MC by means of dose volume histograms and three dimensional gamma analysis for each structure (CTV, OAR, etc.). Results: For dose distributions with the virtual inhomogeneity phantom, AXB was in good agreement with those of MC, except the dose in air region. The dose in air region decreased in order of MCdose kernel of water, the doses in regions for air, bone, and aluminum considerably became higher than those of AXB and MC. The pass rates of the gamma analysis for IMRT dose distributions in head and neck were similar to those of MC in order of AXB11dose calculation accuracy of AXB11 was almost equivalent to the MC dose calculation.

  2. The introduction of automated dispensing and injection during PET procedures: a step in the optimisation of extremity doses and whole-body doses of nuclear medicine staff.

    PubMed

    Covens, P; Berus, D; Vanhavere, F; Caveliers, V

    2010-08-01

    Significant staff exposure is generally expected during PET-and PET/CT applications. Whole-body doses as well as extremity doses are usually higher per procedure compared with SPECT applications. Dispensing individual patient doses and manual injection involves high extremity doses even when heavy weighted syringe shields are used. In some cases the external radiation causes an exposure to the fingertips of more than 500 mSv y(-1), which is the yearly limit. Whole-body doses per procedure are relatively lower compared with extremity doses and are generally spread over the entire procedure (Guillet, B., Quentin, P., Waultier, S., Bourrelly, M., Pisano, P. and Mundler, O. Technologist radiation exposure in routine clinical practice with 18F-FDG PET. J. Nucl. Med. Technol. 33, 175-179 (2005). Optimisation of the individual workload is often used to restrict staff doses, but many PET centres face the need for further optimisation to reduce the staff doses to an acceptable level. During this study the effect of the use of an automated dispensing and injection system for (18)FDG on whole-body doses and extremity doses was evaluated. Detailed dosimetric studies using thermoluminescent and direct ion storage dosimetry were carried out before and after the introduction of this system. The results show that the extremity doses can be reduced by more than 95 % up to a mean level of 10 muSv per handled GBq. At the same time, whole-body doses can be halved during injection of the tracer. This results in a dose reduction of 20 % during the entire procedure of injection, escorting and positioning. In this way, the study shows that with the use of automated dispensing and injection a considerable staff dose reduction can be obtained. PMID:20335185

  3. Energetic dose: Beyond fire and flint?

    USGS Publications Warehouse

    Linder, G.; Rattner, B.; Cohen, J.

    2000-01-01

    Nutritional and bioenergetic interactions influence exposure to environmental chemicals and may affect the risk realized when wildlife are exposed in the field. Here, food-chain analysis focuses on prairie voles (Microtus ochrogaster) and the evaluation of chemical risks associated with paraquat following 10-d dietary exposures. Reproductive effects were measured in 60-d trials that followed exposures to paraquat-tainted feed: control (untainted feed); 21 mg paraquat/kg feed; 63 mg paraquat/kg feed; and feed-restricted control (untainted feed restricted to 60% baseline consumption). Reproductive success was evaluated in control and treated breeding pairs, and a preliminary bioenergetics analysis was completed in parallel to derive exposure dose. Although reproductive performance differed among groups, feed-restriction appeared to be the dominant treatment effect observed in these 10-d feeding exposure/limited reproductive trials. Exposure dose ranged from 3.70-3.76 to 9.41-11.51 mg parquat/kg BW/day at 21 and 63 mg paraquat/kg feed stock exposures, respectively. Energetic doses as ug paraquat/kcal yielded preliminary estimates of energetic costs associated with paraquat exposure, and were similar within treatments for both sexes, ranging from 4.2-5.5 and 13.1-15.0 ug paraquat/kcal for voles exposed to 21 mg/kg feed stock and 63 mg/kg feed stock, respectively. Given the increasing likelihood that environmental chemicals will be found in wildlife habitat at 'acceptable levels', the critical role that wildlife nutrition plays in evaluating ecological risks should be fully integrated into the assessment process. Tools applied to the analysis of risk must gain higher resolution than the relatively crude methods we currently bring to the process.

  4. Low dose titration of copper oxide wire particles for control of gastrointestinal nematodes in weaned kids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to determine whether a low dose of copper oxide wire particles (COWP) would be as effective as a higher dose in reducing gastrointestinal nematodes (GIN) infection. In May 2006, 40 Boer x Spanish doe and wether kids naturally infected with GIN were weaned (97 ± 2 days of age) and ...

  5. Higher dimensional loop quantum cosmology

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangdong

    2016-07-01

    Loop quantum cosmology (LQC) is the symmetric sector of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogeneous cosmological model in n+1 dimensions is quantized by the loop quantization method. Interestingly, we find that the underlying quantum theories are divided into two qualitatively different sectors according to spacetime dimensions. The effective Hamiltonian and modified dynamical equations of n+1 dimensional LQC are obtained. Moreover, our results indicate that the classical big bang singularity is resolved in arbitrary spacetime dimensions by a quantum bounce. We also briefly discuss the similarities and differences between the n+1 dimensional model and the 3+1 dimensional one. Our model serves as a first example of higher dimensional loop quantum cosmology and offers the possibility to investigate quantum gravity effects in higher dimensional cosmology.

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

    SciTech Connect

    Seth, Isheeta; Joiner, Michael C.; Tucker, James D.

    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.

  7. Influence of low-dose and low-dose-rate ionizing radiation on mutation induction in human cells

    NASA Astrophysics Data System (ADS)

    Yatagai, F.; Umebayashi, Y.; Suzuki, M.; Abe, T.; Suzuki, H.; Shimazu, T.; Ishioka, N.; Iwaki, M.; Honma, M.

    This is a review paper to introduce our recent studies on the genetic effects of low-dose and low-dose-rate ionizing radiation (IR). Human lymphoblastoid TK6 cells were exposed to γ-rays at a dose-rate of 1.2 mGy/h (total 30 mGy). The frequency of early mutations (EMs) in the thymidine kinase ( TK) gene locus was determined to be 1.7 × 10 -6, or 1.9-fold higher than the level seen in unirradated controls [Umebayashi, Y., Honma, M., Suzuki, M., Suzuki, H., Shimazu, T., Ishioka, N., Iwaki, M., Yatagai, F., Mutation induction in cultured human cells after low-dose and low-dose-rate γ-ray irradiation: detection by LOH analysis. J. Radiat. Res., 48, 7-11, 2007]. These mutants were then analyzed for loss of heterozygosity (LOH) events. Small interstitial-deletion events were restricted to the TK gene locus and were not observed in EMs in unirradated controls, but they comprised about half of the EMs (8/15) after IR exposure. Because of the low level of exposure to IR, this specific type of event cannot be considered to be the direct result of an IR-induced DNA double strand break (DSB). To better understand the effects of low-level IR exposure, the repair efficiency of site-specific chromosomal DSBs was also examined. The pre γ-irradiation under the same condition did not largely influence the efficiency of DSB repair via end-joining, but enhanced such efficiency via homologous recombination to an about 40% higher level (unpublished data). All these results suggest that DNA repair and mutagenesis can be indirectly influenced by low-dose/dose-rate IR.

  8. Chromosome aberrations in human lymphocytes induced by 250 MeV protons: effects of dose, dose rate and shielding

    NASA Technical Reports Server (NTRS)

    George, K.; Willingham, V.; Wu, H.; Gridley, D.; Nelson, G.; Cucinotta, F. A.

    2002-01-01

    Although the space radiation environment consists predominantly of energetic protons, astronauts inside a spacecraft are chronically exposed to both primary particles as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary neutrons and secondary charged particles can have an LET value that is greater than the primary protons and, therefore, produce a higher relative biological effectiveness (RBE). Using the accelerator facility at Loma Linda University, we exposed human lymphocytes in vitro to 250 MeV protons with doses ranging from 0 to 60 cGy at three different dose rates: a low dose rate of 7.5 cGy/h, an intermediate dose rate of 30 cGy/h and a high dose rate of 70 cGy/min. The effect of 15 g/cm2 aluminum shielding on the induction of chromosome aberrations was investigated for each dose rate. After exposure, lymphocytes were incubated in growth medium containing phytohemagglutinin (PHA) and chromosome spreads were collected using a chemical-induced premature chromosome condensation (PCC) technique. Aberrations were analyzed using the fluorescence in situ hybridization (FISH) technique with three different colored chromosome-painting probes. The frequency of reciprocal and complex-type chromosome exchanges were compared in shielded and unshielded samples. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  9. Chromosome aberrations in human lymphocytes induced by 250 MeV protons: effects of dose, dose rate and shielding.

    PubMed

    George, K; Willingham, V; Wu, H; Gridley, D; Nelson, G; Cucinotta, F A

    2002-01-01

    Although the space radiation environment consists predominantly of energetic protons, astronauts inside a spacecraft are chronically exposed to both primary particles as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary neutrons and secondary charged particles can have an LET value that is greater than the primary protons and, therefore, produce a higher relative biological effectiveness (RBE). Using the accelerator facility at Loma Linda University, we exposed human lymphocytes in vitro to 250 MeV protons with doses ranging from 0 to 60 cGy at three different dose rates: a low dose rate of 7.5 cGy/h, an intermediate dose rate of 30 cGy/h and a high dose rate of 70 cGy/min. The effect of 15 g/cm2 aluminum shielding on the induction of chromosome aberrations was investigated for each dose rate. After exposure, lymphocytes were incubated in growth medium containing phytohemagglutinin (PHA) and chromosome spreads were collected using a chemical-induced premature chromosome condensation (PCC) technique. Aberrations were analyzed using the fluorescence in situ hybridization (FISH) technique with three different colored chromosome-painting probes. The frequency of reciprocal and complex-type chromosome exchanges were compared in shielded and unshielded samples. PMID:12539753

  10. Chromosome aberrations in human lymphocytes induced by 250 MeV protons: effects of dose, dose rate and shielding

    NASA Astrophysics Data System (ADS)

    George, K.; Willingham, V.; Wu, H.; Gridley, D.; Nelson, G.; Cucinotta, F. A.

    Although the space radiation environment consists predominantly of energetic protons, astronauts inside a spacecraft are chronically exposed to both primary particles as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary neutrons and secondary charged particles can have an LET value that is greater than the primary protons and, therefore, produce a higher relative biological effectiveness (RBE). Using the accelerator facility at Loma Linda University, we exposed human lymphocytes in vitro to 250 MeV protons with doses ranging from 0 to 60 cGy at three different dose rates: a low dose rate of 7.5 cGy/h, an intermediate dose rate of 30 cGy/h and a high dose rate of 70 cGy/min. The effect of 15 g/cm 2 aluminum shielding on the induction of chromosome aberrations was investigated for each dose rate. After exposure, lymphocytes were incubated in growth medium containing phytohemagglutinin (PHA) and chromosome spreads were collected using a chemical-induced premature chromosome condensation (PCC) technique. Aberrations were analyzed using the fluorescence in situ hybridization (FISH) technique with three different colored chromosome-painting probes. The frequency of reciprocal and complex-type chromosome exchanges were compared in shielded and unshielded samples.

  11. A MULTIMODEL APPROACH FOR CALCULATING BENCHMARK DOSE

    EPA Science Inventory


    A Multimodel Approach for Calculating Benchmark Dose
    Ramon I. Garcia and R. Woodrow Setzer

    In the assessment of dose response, a number of plausible dose- response models may give fits that are consistent with the data. If no dose response formulation had been speci...

  12. The Dose Makes the Poison.

    ERIC Educational Resources Information Center

    Ottoboni, Alice

    1992-01-01

    A Toxicologist discusses common misconception that all chemicals are poisonous to people and the environment and how these misconceptions are perpetuated. Describes what makes a chemical toxic. Defines related concepts including dose, acute and chronic toxicity, and natural verses synthetic chemicals. (MCO)

  13. BENCHMARK DOSE TECHNICAL GUIDANCE DOCUMENT

    EPA Science Inventory

    The U.S. EPA conducts risk assessments for an array of health effects that may result from exposure to environmental agents, and that require an analysis of the relationship between exposure and health-related outcomes. The dose-response assessment is essentially a two-step proce...

  14. Dose modeling in ultraviolet phototherapy

    SciTech Connect

    Grimes, David Robert; Robbins, Chris; O'Hare, Neil John

    2010-10-15

    Purpose: Ultraviolet phototherapy is widely used in the treatment of numerous skin conditions. This treatment is well established and largely beneficial to patients on both physical and psychological levels; however, overexposure to ultraviolet radiation (UVR) can have detrimental effects, such as erythemal responses and ocular damage in addition to the potentially carcinogenic nature of UVR. For these reasons, it is essential to control and quantify the radiation dose incident upon the patient to ensure that it is both biologically effective and has the minimal possible impact on the surrounding unaffected tissue. Methods: To date, there has been little work on dose modeling, and the output of artificial UVR sources is an area where research has been recommended. This work characterizes these sources by formalizing an approach from first principles and experimentally examining this model. Results: An implementation of a line source model is found to give impressive accuracy and quantifies the output radiation well. Conclusions: This method could potentially serve as a basis for a full computational dose model for quantifying patient dose.

  15. Peritoneal Dialysis Dose and Adequacy

    MedlinePlus

    ... Organizations​​ . (PDF, 345 KB)​​​​​ Alternate Language URL Peritoneal Dialysis Dose and Adequacy Page Content On this page: ... from the abdominal cavity. [ Top ] Types of Peritoneal Dialysis The two types of peritoneal dialysis differ mainly ...

  16. The effective dose equivalent and effective dose for hot particles on the skin.

    PubMed

    Xu, X George

    2005-07-01

    Whole body exposure from photon-emitting hot particles is a relatively new problem. Until recently, the U.S. Nuclear Regulatory Commission required the use of deep dose equivalent (DDE) to estimate and report whole body exposures from hot particles. In this study, effective dose equivalent (EDE) and effective dose (ED) were calculated for point sources with photon energies between 0.1 MeV to 2.0 MeV for 74 locations covering the entire body surface, using the MCNP code and the MIRD-type stylized phantoms. Tabulated data show that the sources located near the upper chest and the lower waist have the highest EDE and ED, while sources near the top of head and feet yielded the smallest. The calculated DDE values are much higher than the EDE values. For an exposure of 75 microCi h(-1) to a 60Co source located at the center upper chest area, the EDE is 36.5 microSv (3.65 mrem), which is a factor of 240 smaller than the corresponding DDE. EDE and ED data are tabulated for quick reference by users in nuclear power plants. PMID:15951692

  17. Tank Z-361 dose rate calculations

    SciTech Connect

    Richard, R.F.

    1998-09-30

    Neutron and gamma ray dose rates were calculated above and around the 6-inch riser of tank Z-361 located at the Plutonium Finishing Plant. Dose rates were also determined off of one side of the tank. The largest dose rate 0.029 mrem/h was a gamma ray dose and occurred 76.2 cm (30 in.) directly above the open riser. All other dose rates were negligible. The ANSI/ANS 1991 flux to dose conversion factor for neutrons and photons were used in this analysis. Dose rates are reported in units of mrem/h with the calculated uncertainty shown within the parentheses.

  18. Patient Dose In Diagnostic Radiology: When & How?

    NASA Astrophysics Data System (ADS)

    Lassen, Margit; Gorson, Robert O.

    1980-08-01

    Different situations are discussed in which it is of value to know radiation dose to the patient in diagnostic radiology. Radiation dose to specific organs is determined using the Handbook on Organ Doses published by the Bureau of Radiological Health of the Food and Drug Administration; the method is applied to a specific case. In this example dose to an embryo is calculated in examinations involving both fluoroscopy and radiography. In another example dose is determined to a fetus in late pregnancy using tissue air ratios. Patient inquiries about radiation dose are discussed, and some answers are suggested. The reliability of dose calculations is examined.

  19. [Absorbed doses in dental radiology].

    PubMed

    Bianchi, S D; Roccuzzo, M; Albrito, F; Ragona, R; Anglesio, S

    1996-01-01

    The growing use of dento-maxillo-facial radiographic examinations has been accompanied by the publication of a large number of studies on dosimetry. A thorough review of the literature is presented in this article. Most studies were carried out on tissue equivalent skull phantoms, while only a few were in vivo. The aim of the present study was to evaluate in vivo absorbed doses during Orthopantomography (OPT). Full Mouth Periapical Examination (FMPE) and Intraoral Tube Panoramic Radiography (ITPR). Measurements were made on 30 patients, reproducing clinical conditions, in 46 anatomical sites, with 24 intra- and 22 extra-oral thermoluminiscent dosimeters (TLDS). The highest doses were measured, in orthopantomography, at the right mandibular angle (1899 mu Gy) in FMPE on the right naso-labial fold (5640 mu Gy and in ITPR on the palatal surface of the left second upper molar (1936 mu Gy). Intraoral doses ranged from 21 mu Gy, in orthopantomography, to 4494 mu Gy in FMPE. Standard errors ranged from 142% in ITPR to 5% in orthopantomography. The highest rate of standard errors was found in FMPE and ITPR. The data collected in this trial are in agreement with others in major literature reports. Disagreements are probably due to different exam acquisition and data collections. Such differences, presented comparison in several sites, justify lower doses in FMPE and ITPR. Advantages and disadvantages of in vivo dosimetry of the maxillary region are discussed, the former being a close resemblance to clinical conditions of examination and the latter the impossibility of collecting values in depth of tissues. Finally, both ITPR and FMPE required lower doses than expected, and can be therefore reconsidered relative to their radiation risk. PMID:8966249

  20. Mapping of dose distribution from IMRT onto MRI-guided high dose rate brachytherapy using deformable image registration for cervical cancer treatments: preliminary study with commercially available software

    PubMed Central

    Huq, M. Saiful; Houser, Chris; Beriwal, Sushil; Michalski, Dariusz

    2014-01-01

    Purpose For patients undergoing external beam radiation therapy (EBRT) and brachytherapy, recommendations for target doses and constraints are based on calculation of the equivalent dose in 2 Gy fractions (EQD2) from each phase. At present, the EBRT dose distribution is assumed to be uniform throughout the pelvis. We performed a preliminary study to determine whether deformable dose distribution mapping from the EBRT onto magnetic resonance (MR) images for the brachytherapy would yield differences in doses for organs at risk (OARs) and high-risk clinical target volume (HR-CTV). Material and methods Nine cervical cancer patients were treated to a total dose of 45 Gy in 25 fractions using intensity-modulated radiation therapy (IMRT), followed by MRI-based 3D high dose rate (HDR) brachytherapy. Retrospectively, the IMRT planning CT images were fused with the MR image for each fraction of brachytherapy using deformable image registration. The deformed IMRT dose onto MR images were converted to EQD2 and compared to the uniform dose assumption. Results For all patients, the EQD2 from the EBRT phase was significantly higher with deformable registration than with the conventional uniform dose distribution assumption. The mean EQD2 ± SD for HR-CTV D90 was 45.7 ± 0.7 Gy vs. 44.3 Gy for deformable vs. uniform dose distribution, respectively (p < 0.001). The dose to 2 cc of the bladder, rectum, and sigmoid was 46.4 ± 1.2 Gy, 46.2 ± 1.0 Gy, and 48.0 ± 2.5 Gy, respectively with deformable dose distribution, and was significantly higher than with uniform dose distribution (43.2 Gy for all OAR, p < 0.001). Conclusions This study reveals that deformed EBRT dose distribution to HR-CTV and OARs in MR images for brachytherapy is technically feasible, and achieves differences compared to a uniform dose distribution. Therefore, the assumption that EBRT contributes the same dose value may need to be carefully investigated further based on deformable image registration. PMID:25097559