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Sample records for repeat dose study

  1. Repeated dose titration versus age-based method in electroconvulsive therapy: a pilot study.

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    Aten, Jan Jaap; Oudega, Mardien; van Exel, Eric; Stek, Max L; van Waarde, Jeroen A

    2015-06-01

    In electroconvulsive therapy (ECT), a dose titration method (DTM) was suggested to be more individualized and therefore more accurate than formula-based dosing methods. A repeated DTM (every sixth session and dose adjustment accordingly) was compared to an age-based method (ABM) regarding treatment characteristics, clinical outcome, and cognitive functioning after ECT. Thirty-nine unipolar depressed patients dosed using repeated DTM and 40 matched patients treated with ABM were compared. Montgomery-Åsberg Depression Rating Scale (MADRS) and Mini-Mental State Examination (MMSE) were assessed at baseline and at the end of the index course, as well as the total number of ECT sessions. Both groups were similar regarding age, sex, psychotic features, mean baseline MADRS, and median baseline MMSE. At the end of the index course, the two methods showed equal outcome (mean end MADRS, 11.6 ± 8.3 in DTM and 9.5 ± 7.6 in ABM (P = 0.26); median end MMSE, 28 (25-29) and 28 (25-29.8), respectively (P = 0.81). However, the median number of all ECT sessions differed 16 (11-22) in DTM versus 12 (10-14.8) in ABM; P = 0.02]. Using regression analysis, dosing method and age were independently associated with the total number of ECT sessions, with less sessions needed in ABM (P = 0.02) and in older patients (P = 0.001). In this comparative cohort study, ABM and DTM showed equal outcome for depression and cognition. However, the median ECT course duration in repeated DTM appeared longer. Additionally, higher age was associated with shorter ECT courses regardless of the dosing method. Further prospective studies are needed to confirm these findings.

  2. Repeated dose titration versus age-based method in electroconvulsive therapy: a pilot study

    NARCIS (Netherlands)

    Aten, J.J.; Oudega, M.L.; van Exel, E.; Stek, M.L.; van Waarde, J.A.

    2015-01-01

    In electroconvulsive therapy (ECT), a dose titration method (DTM) was suggested to be more individualized and therefore more accurate than formula-based dosing methods. A repeated DTM (every sixth session and dose adjustment accordingly) was compared to an age-based method (ABM) regarding treatment

  3. Study of four week repeated dose toxic test of Sweet Bee Venom in Beagle Dogs

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    Jae-Seuk Park

    2010-12-01

    Full Text Available Objectives: This study was performed to analyse four week repeated dose toxicity of Sweet Bee Venom(Sweet BV extracted from the bee venom in Beagle dogs. Methods: All experiments were conducted under the regulations of Good Laboratory Practice (GLP at Biotoxtech Company, a non-clinical study authorized institution. Male and female Beagle dogs of 5-6 months old were chosen for the pilot study of four week repeated dose toxicity of Sweet BV which was administered at the level of 0.56㎎/㎏ body weight which is eighty times higher than the clinical application dosage as the high dosage, followed by 0.28 and 0.14㎎/㎏ as midium and low dosage, respectively. Equal amount of excipient(normal saline to the Sweet BV experiment groups was administered as the control group every day for four weeks. Results: 1. No mortality was witnessed in all of the experiment groups. 2. All experiment groups were appealed pain sense in the treating time compared to the control group, and hyperemia and movement disorder were observed around the area of administration in all experiment groups, and higher occurrence in the higher dosage treatment. 3. For weight measurement, Neither male nor female groups showed significant changes. 4. In the urine analysis, CBC and biochemistry didn't show any significant changes in the experiment groups compared with control group. 5. For weight measurement of organs, experiment groups didn't show any significant changes compared with control group. 6. To verify abnormalities of organs and tissues, thigh muscle which treated with Sweet BV, cerebrum, liver, lung, kidney, and spinal cords were removed and conducted histologocal observation with H-E staining. In the histologocal observation of thigh muscle, cell infiltration, inflammatory, degeneration, necrosis of muscle fiber, and fibrosis were found in both thigh tissue. And the changes were depend on the dose of Sweet BV. But another organs were not detected in any abnormalities. 7

  4. A 28-Day Repeated Dose Toxicological Study of an Aqueous Extract of Morus Alba L.

    Science.gov (United States)

    Marx, Tennille K; Glávits, Róbert; Endres, John R; Palmer, Philip A; Clewell, Amy E; Murbach, Timothy S; Hirka, Gábor; Pasics, Ilona

    2016-11-01

    Morus alba L. (white mulberry) leaves are one of the oldest recognized traditional Chinese medicines. More recently, M alba leaves and their constituents, particularly iminosugars (or azasugars), have garnered attention for their ability to maintain normal blood glucose concentrations, an effect identified in both animal studies and human clinical trials. Reducose (Phynova Group Limited) is a commercial water-soluble extract of M alba leaves standardized to 5% 1-deoxynojirimycin (DNJ), an iminosugar with α-glucosidase inhibition properties. Although there is an extensive history of consumption of M alba leaves by humans and animals worldwide, suggesting that the leaves and their extracts have a relatively good safety profile, we are unaware of safety assessments on an extract containing a higher amount of DNJ than that occurs naturally. The current 28-day repeated dose oral toxicity study in rats, conducted according to Organisation for Economic Co-operation and Development guidelines, was carried out to assess the safety of Reducose. Male and female Hsd.Han Wistar rats (4 groups of 10 animals/sex) were administered Reducose via gavage at doses of 0, 1,000, 2,000 and 4,000 mg/kg body weight (bw)/d. No treatment-related mortality or adverse effects (per clinical observations, body weight/weight gain, food consumption, ophthalmoscopy, clinical pathology, gross pathology, organ weights, or histopathology) were observed, and no target organs were identified. The no observed adverse effect level was determined to be 4,000 mg/kg bw/d for both male and female rats, the highest dose tested. © The Author(s) 2016.

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

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

    1998-10-01

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

  6. Single, 14-Day, and 13-Week Repeated Dose Toxicity Studies of Daily Oral Gelidium elegans Extract Administration to Rats.

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    Choi, Jia; Ryu, Su-Jung; Kim, Kui-Jin; Kim, Hyung-Min; Chung, Hee-Chul; Lee, Boo-Yong

    2018-01-20

    Gelidium elegans extract (GEE) is derived from a red alga from the Asia-Pacific region, which has antioxidant, anti-adipogenic, and anti-hyperglycemic effects. However, detailed studies of the toxicology of GEE have not been performed. We evaluated the single oral dose toxicity of GEE in male and female Sprague-Dawley (CD) rats. GEE did not cause deaths or have toxic effects at dosages of 5000 mg/kg/day, although compound-colored stools and diarrhea were observed in both sexes, which lasted 5000 mg/kg. We next evaluated the repeated oral dose toxicity of GEE in CD rats over 14 days and 13 weeks. GEE did not induce any significant toxicological changes in either sex at 2000 mg/kg/day. Repeated oral dose toxicity studies showed no adverse effects, in terms of clinical signs, mortality, body mass, food consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy, organ masses, or histopathology, at dosages of 500, 1000, or 2000 mg/kg/day. The no observed adverse effect level (NOAEL) for GEE is thus likely to be >2000 mg/kg/day, and no pathology was identified in potential target organs. Therefore, this study indicates that repeated oral dosing with GEE is safe in CD rats.

  7. Single, 14-Day, and 13-Week Repeated Dose Toxicity Studies of Daily Oral Gelidium elegans Extract Administration to Rats

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    Jia Choi

    2018-01-01

    Full Text Available Gelidium elegans extract (GEE is derived from a red alga from the Asia–Pacific region, which has antioxidant, anti-adipogenic, and anti-hyperglycemic effects. However, detailed studies of the toxicology of GEE have not been performed. We evaluated the single oral dose toxicity of GEE in male and female Sprague-Dawley (CD rats. GEE did not cause deaths or have toxic effects at dosages of 5000 mg/kg/day, although compound-colored stools and diarrhea were observed in both sexes, which lasted <2 days. Therefore, the LD50 of GEE is likely to be >5000 mg/kg. We next evaluated the repeated oral dose toxicity of GEE in CD rats over 14 days and 13 weeks. GEE did not induce any significant toxicological changes in either sex at 2000 mg/kg/day. Repeated oral dose toxicity studies showed no adverse effects, in terms of clinical signs, mortality, body mass, food consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy, organ masses, or histopathology, at dosages of 500, 1000, or 2000 mg/kg/day. The no observed adverse effect level (NOAEL for GEE is thus likely to be >2000 mg/kg/day, and no pathology was identified in potential target organs. Therefore, this study indicates that repeated oral dosing with GEE is safe in CD rats.

  8. Repeated dose studies with pure Epigallocatechin-3-gallate demonstrated dose and route dependant hepatotoxicity with associated dyslipidemia.

    Science.gov (United States)

    Ramachandran, Balaji; Jayavelu, Subramani; Murhekar, Kanchan; Rajkumar, Thangarajan

    2016-01-01

    EGCG (Epigallocatechin-3-gallate) is the major active principle catechin found in green tea. Skepticism regarding the safety of consuming EGCG is gaining attention, despite the fact that it is widely being touted for its potential health benefits, including anti-cancer properties. The lack of scientific data on safe dose levels of pure EGCG is of concern, while EGCG has been commonly studied as a component of GTE (Green tea extract) and not as a single active constituent. This study has been carried out to estimate the maximum tolerated non-toxic dose of pure EGCG and to identify the treatment related risk factors. In a fourteen day consecutive treatment, two different administration modalities were compared, offering an improved [i.p (intraperitoneal)] and limited [p.o (oral)] bioavailability. A trend of dose and route dependant hepatotoxicity was observed particularly with i.p treatment and EGCG increased serum lipid profile in parallel to hepatotoxicity. Fourteen day tolerable dose of EGCG was established as 21.1 mg/kg for i.p and 67.8 mg/kg for p.o. We also observed that, EGCG induced effects by both treatment routes are reversible, subsequent to an observation period for further fourteen days after cessation of treatment. It was demonstrated that the severity of EGCG induced toxicity appears to be a function of dose, route of administration and period of treatment.

  9. Repeated dose studies with pure Epigallocatechin-3-gallate demonstrated dose and route dependant hepatotoxicity with associated dyslipidemia

    Directory of Open Access Journals (Sweden)

    Balaji Ramachandran

    Full Text Available EGCG (Epigallocatechin-3-gallate is the major active principle catechin found in green tea. Skepticism regarding the safety of consuming EGCG is gaining attention, despite the fact that it is widely being touted for its potential health benefits, including anti-cancer properties. The lack of scientific data on safe dose levels of pure EGCG is of concern, while EGCG has been commonly studied as a component of GTE (Green tea extract and not as a single active constituent. This study has been carried out to estimate the maximum tolerated non-toxic dose of pure EGCG and to identify the treatment related risk factors. In a fourteen day consecutive treatment, two different administration modalities were compared, offering an improved [i.p (intraperitoneal] and limited [p.o (oral] bioavailability. A trend of dose and route dependant hepatotoxicity was observed particularly with i.p treatment and EGCG increased serum lipid profile in parallel to hepatotoxicity. Fourteen day tolerable dose of EGCG was established as 21.1 mg/kg for i.p and 67.8 mg/kg for p.o. We also observed that, EGCG induced effects by both treatment routes are reversible, subsequent to an observation period for further fourteen days after cessation of treatment. It was demonstrated that the severity of EGCG induced toxicity appears to be a function of dose, route of administration and period of treatment. Keywords: EGCG, Green tea, Serum lipids, Dose dependant toxicity, Route dependant toxicity, Liver toxicity, Dyslipidemia

  10. Acute toxicity and the 28-day repeated dose study of a Siddha medicine Nuna Kadugu in rats

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    Ramaswamy Ramaswamy

    2012-10-01

    Full Text Available Abstract Background Nuna Kadugu (NK, a Siddha medicine prepared from leaves and fruits of Morinda Pubescens, used for the treatment of various skin diseases. Though NK has been widely used for several decades, no scientific report was available on its safety. Present study was undertaken to demonstrate the oral toxicity of NK in Sprague Dawley rats. Methods Acute and 28-day repeated oral toxicity studies were performed following OECD test guidelines 423 and 407, respectively, with minor modifications. In acute oral toxicity study, NK was administered at 2000mg/kg b.wt., p.o and animals were observed for toxic signs at 0, 0.5, 1, 4, 24 h and for next 14 days. Gross pathology was performed at the end of the study. In repeated dose, the 28- day oral toxicity study, NK was administered at 300, 600 and 900 mg/kg b.wt./p.o/day. Two satellite groups (control and high dose were also maintained to determine the delayed onset toxicity of NK. Animals were observed for mortality, morbidity, body weight changes, feed and water intake. Haematology, clinical biochemistry, electrolytes, gross pathology, relative organ weight and histopathological examination were performed. Results In acute toxicity study, no treatment related death or toxic signs were observed with NK administration. In the repeated dose study, no significant differences in body weight changes, food / water intake, haematology, clinical biochemistry and electrolytes content were observed between control and NK groups. No gross pathological findings and difference in relative organ weights were observed between control and NK treated rats. Histopathological examination revealed no abnormalities with NK treatment. Conclusion Acute study reveals that the LD50 of NK is greater than 2000mg/kg, b.wt. in fasted female rats and can be classified as Category 5. 28-day repeated oral toxicity demonstrates that the No Observed Adverse Effect Level of NK is greater than 900 mg/kg b.wt./day, p.o in rats

  11. Repeated-dose toxicological studies of Tithonia diversifolia (Hemsl.) A. gray and identification of the toxic compounds.

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    Passoni, Flávia Donaire; Oliveira, Rejane Barbosa; Chagas-Paula, Daniela Aparecida; Gobbo-Neto, Leonardo; Da Costa, Fernando Batista

    2013-05-20

    Tithonia diversifolia (Hemsl.) A. Gray has been commonly used in folk medicine to treat abscesses, microbiological infections, snake bites, malaria and diabetes. Both anti-inflammatory and anti-malarial properties have been identified using appropriate assays, but the effective doses have demonstrated toxic effects for the experimental animals. Most of the pharmacological activities have been attributed to sesquiterpene lactones (STLs) and some chlorogenic acid derivatives (CAs) in the leaves of this species. This work aimed to evaluate the repeated-dose toxicity of an aqueous extract (AE) from Tithonia diversifolia leaves and to compare the results with an extract rich in STLs (LRE) and a polar extract (PE) without STLs but rich in CAs. The purpose of this work was to provide insights into the identity of the compounds responsible for the toxic effects of Tithonia diversifolia. The major classes of compounds were confirmed in each extract by IR spectra and HPLC-UV-DAD profiling using previously isolated or standard compounds. The toxicity of each extract was evaluated in a repeated-dose toxicity study in Wistar rats for 90 days. The AE is composed of both STLs and CAs, the LRE is rich in STLs, and the PE is rich in CAs. The AE caused alterations in haematological parameters but few alterations in biochemical parameters and was relatively safe at doses lower than 100mg/kg. However, the PE and LRE demonstrated several adverse effects by damaging the liver and kidneys, respectively. STLs and CAs can be toxic in prolonged use at higher doses in extracts prepared from Tithonia diversifolia by affecting the kidneys and liver. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. 40 CFR 799.9305 - TSCA Repeated dose 28-day oral toxicity study in rodents.

    Science.gov (United States)

    2010-07-01

    ... considered necessary. The limit test applies except when human exposure indicates the need for a higher dose..., stereotypies (e.g., excessive grooming, repetitive circling) or bizarre behaviour (e.g., self-mutilation...

  13. A 4-Week Repeated-Dose Oral Toxicity Study of Bojungikgi-Tang in Crl:CD Sprague Dawley Rats

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    Sae-Rom Yoo

    2017-01-01

    Full Text Available Traditional herbal medicines have been used for centuries in Asian countries. However, recent studies have led to increasing concerns about the safety and toxicity of herbal prescriptions. Bojungikgi-tang (BJIGT, a herbal decoction, has been used in Korea to improve physical strength. To establish the safety information, BJIGT water extract was evaluated in a 4-week repeated-dose oral toxicity test in Crl:CD Sprague Dawley rats. BJIGT was orally administered in daily doses of 0, 500, 1000, and 2000 mg/kg/day for 4 weeks via oral gavage in male and female rats. We examined the mortality, clinical signs, body weight change, food intake, organ weights, hematology, serum biochemistry, and urinalysis parameters. No significant changes were observed in mortality, clinical sings, body weight, food intake, organ weights, hematology, serum biochemistry, and urinalysis parameters between the control group and the BJIGT-treated groups in the rats of both sexes. The results indicate that BJIGT did not induce toxic effects at a dose level up to 2000 mg/kg in rats. Thus, this concentration is considered the nonobservable effect dose in rats and is appropriate for a 13-week subchronic toxicity study.

  14. A flow-cytometric NK-cytotoxicity assay adapted for use in rat repeated dose toxicity studies

    International Nuclear Information System (INIS)

    Marcusson-Staahl, Maritha; Cederbrant, Karin

    2003-01-01

    A recent regulatory document for immunotoxicity testing of new pharmaceutical drugs includes cytotoxic natural killer (NK)-cell function as a required parameter in repeated dose toxicity studies. The classical 51 Cr-release assay is the conventional test for cytotoxicity testing but several drawbacks with this assay has increased the demand for new reliable test systems. Here, we describe the optimisation of a flow-cytometric cytotoxicity assay especially adapted for regulatory rat studies in drug development. The test principle is based on target cell labelling with 5-(6)-carboxy-fluorescein succinimidyl ester (CFSE) and subsequent DNA-labelling with propidium iodide (PI) for identification of target cells with compromised cell membranes. The results are expressed as percentage of dead targets on a cell-to-cell basis. The final format of the assay includes 0.5 ml peripheral blood, 1.25x10 5 effector cells per sample, and collection of 500 target events by flow-cytometry. When NKR-P1+ cells were removed from the effector cell population by magnetic depletion the relative proportion decreased from 6 to 0.08%. The corresponding cytotoxic activity decreased from 68 to 8%. Also, the cytotoxic activity showed a significant and positive correlation with the proportion of NK-cells present in the effector cell suspension. Thus, the cytotoxicity measured is almost exclusively exerted by NK-cells. The current flow-cytometric test benefits from using peripheral blood as a source for effector cells since it will not conflict with the use of spleen for histopathological investigations in repeated dose toxicity studies. Additionally, since only a minimal number of effector cells are required per sample repeated testing of the same animal is enabled

  15. Zinc oxide nanoparticles: a 90-day repeated-dose dermal toxicity study in rats

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    Ryu HJ

    2014-12-01

    was dose-dependent irritation at the site of application, there were no abnormal findings related to ZnO NPs in other organs. Increased concentrations of ZnO in the liver, small intestine, large intestine, and feces were thought to result from oral ingestion of ZnO NPs via licking. Penetration of ZnO NPs through the skin seemed to be limited via the dermal route. This study demonstrates that there was no observed adverse effect of ZnO NPs up to 1,000 mg/kg body weight when they are applied dermally. Keywords: zinc oxide, nanoparticles, subchronic toxicity, dermal exposure

  16. Evaluation of the repeated-dose liver micronucleus assay using 2,4-dinitrotoluene: a report of a collaborative study by CSGMT/JEMS.MMS.

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    Maeda, Akihisa; Tsuchiyama, Hiromi; Asaoka, Yoshiji; Hirakata, Mikito; Miyoshi, Tomoya; Oshida, Keiyu; Miyamoto, Yohei

    2015-03-01

    The liver micronucleus assay using young adult rats has the potential to detect liver carcinogens by repeated dosing, and could be expected to be integrated into repeated-dose toxicity studies using a hepatocyte isolation method without the traditional in situ collagenase perfusion. In this study, to assess the performance of the repeated-dose liver micronucleus assay, 2,4-dinitrotoluene (DNT), which is a rodent liver carcinogen, was administered orally to male rats at doses of 50, 100 and 200 mg/kg/day once daily for 14 or 28 consecutive days, and the frequencies of micronucleated hepatocytes (MNHEPs) and micronucleated immature erythrocytes (MNIMEs) were examined. Significant increases in the MNHEPs were observed at 50 mg/kg/day or more in the 14-day treatment, and 50 and 100 mg/kg/day in the 28-day treatment. These increases were dependent on both the dose and the number of administrations, which indicates the possibility that the MNHEPs accumulate as a result of repeated dosing. In contrast, no increase in the MNIMEs was observed. In conclusion, the repeated-dose liver micronucleus assay using young adult rats is sufficiently sensitive to detect the genotoxicity of 2,4-DNT at a low dose.

  17. Study of four weeks repeated-dose toxic test of Sweet Bee Venom in rats Original Articles

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    Kwon Hae-Yon

    2011-03-01

    Full Text Available Objectives: This study was performed to analyse four weeks repeated -dose toxicity of Sweet Bee Venom (SBV-pure melittin, the major component of honey bee venom in rats. Methods: All experiments were conducted under the regulations of Good Laboratory Practice (GLPat Biotoxtech Company, a non-clinical study authorized institution. Male and female rats of 5 weeks old were chosen for the pilot study of four weeks repeated-dose toxicity and was injected at the level of 0.56 mg/kg body weight (eighty times higher than the clinical application dosage as the high dosage, followed by 0.28 and 0.14 mg/kg as midium and low dosage, respectively. Equal amount of normal saline was injected as the control group every day for four weeks. Results: 1. No mortality was witnessed in all of the experiment groups. 2. All experiment groups appealed pain sense in the treating time compared to the control group, and side effects such as hyperemia and movement disorder were observed around the area of injection in all experiment groups, and the higher dosage in treatment, the higher occurrence in side effects. 3. Concerning weight measurement, neither male nor female groups showed significant changes compared to the control group. 4. Concerning to the CBC and biochemistry, all experiment groups didn't show any significant changes compared to the control group. 5. Concerning weight measurement of organs, experiment groups didn't show any significant changes compared to the control group. 6. To verify abnormalities of organs and tissues, those such as cerebellum, cerebrum, liver, lung, kidney,and spinal cords were removed and we conducted histologocal observation with H-E staining.Concerning the histologocal observation of liver tissues, some fatty changes were observed around portal vein in 0.56 mg/kg experiment group. But another organs were not detected in any abnormalities. 7. The proper high dosage of SBV for the thirteen weeks repeated test in rats may be 0.28 mg

  18. Pharmacokinetic evaluation of pamidronate after oral administration: a study on dose proportionality, absolute bioavailability, and effect of repeated administration

    DEFF Research Database (Denmark)

    Hyldstrup, Lars; Flesch, G; Hauffe, S A

    1993-01-01

    30 minutes at constant infusion rate. Repeated peroral doses (75 and 150 mg) were administered to 12 females (aged 51-70 years) for 10 consecutive days. Urinary excretion of pamidronate after peroral and i.v. administration was used for estimation of pamidronate absorption. Renal excretion...... of pamidronate ranged from 0.01% to 0.35% of dose, with mean values of 0.11, 0.16, and 0.18% for 75, 150, and 300 mg, respectively. After i.v. infusion, the renal excretion of pamidronate was 26-53% of the dose, lower than for other bisphosphonates. The absolute bioavailability was 0.31% (range 0.08-0.7%) after...

  19. A study to evaluate safety and tolerability of repeated doses of tirasemtiv in patients with amyotrophic lateral sclerosis.

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    Shefner, Jeremy M; Watson, Mary Lou; Meng, Lisa; Wolff, Andrew A

    2013-12-01

    Abstract Tirasemtiv is a fast skeletal muscle activator that increases the sensitivity of the sarcomere to calcium, increasing the efficiency of muscle contraction when the muscle is stimulated at submaximal contraction frequencies. A previous study showed single doses of tirasemtiv to be well tolerated and associated with potentially important improvements in a variety of functional outcomes. This study determined safety of tirasemtiv when given at doses up to 500 mg daily for three weeks. Tirasemtiv was given as a single daily dose up to 375 mg for two weeks, with and without concomitant riluzole. In a separate cohort, an ascending dose protocol evaluated a total dose of 500 mg daily given in two divided doses. Safety and tolerability were assessed, as well as measures of function, muscle strength and endurance. Results showed that tirasemtiv was well tolerated, with dizziness the most common adverse event. Tirasemtiv approximately doubled the serum concentration of riluzole. Trends were noted for improvement in ALSFRS-R, Maximum Minute Ventilation, and Nasal Inspiratory Pressure. In conclusion, tirasemtiv is well tolerated and can be given safely with a reduced dose of riluzole. Positive trends in multiple exploratory outcome measures support the further study of this agent in ALS.

  20. Study of a 13-weeks, Repeated, Intramuscular Dose, Toxicity Test of Sweet Bee Venom in Sprague-Dawley Rats

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    Hyunmin Kang

    2014-06-01

    Full Text Available Objectives:This study was performed to analyze a 13-week repeated dose toxicity test of Sweet Bee Venom (SBV extracted from bee venom and administered in Sprague-Dawley (SD rats. Methods:Male and female 5-week-old SD rats were treated once daily with SBV (high-dosage group: 0.28 mg/kg; medium-dosage group: 0.14 mg/kg; or low-dosage group: 0.07 mg/kg for 13 weeks. Normal saline was administered to the control group in a similar manner (0.2 mL/kg. We conducted clinical observations, body weight measurements, ophthalmic examinations, urinalyses, hematology and biochemistry tests, and histological observations using hematoxylin and eosin (H&E staining to identify any abnormalities caused by the SBV treatment. Results:During this study, no mortality was observed in any of the experimental groups. Hyperemia and a movement disorder were observed around the area of in all groups that received SBV treatment, with a higher occurrence in rats treated with a higher dosage. Male rats receiving in the high-dosage group showed a significant decrease in weight during the treatment period. Compared to the control group, no significant changes in the ophthalmic parameters, the urine analyses, the complete blood cell count (CBC, and the biochemistry in the groups treated with SBV. Compared to the control group, some changes in organ weights were observed in the medium-and the high-dosage groups, but the low-dosage group showed no significant changes. Histological examination of thigh muscle indicated cell infiltration, inflammation, degeneration, and necrosis of muscle fiber, as well as fibrosis, in both the medium- and the high-dosage groups. Fatty liver change was observed in the periportal area of rats receiving medium and high dosages of SBV. No other organ abnormalities were observed. Conclusion:Our findings suggest that the No Observed Adverse Effect Level (NOAEL of SBV is approximately 0.07 mg/kg in male and female SD rats.

  1. Evaluation of the repeated dose liver micronucleus assay using young adult rats with cyclophosphamide monohydrate: a report of a collaborative study by CSGMT/JEMS.MMS.

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    Matsumoto, Kazumi; Zaizen, Kazuyo; Miyamoto, Atsushi; Wako, Yumi; Kawasako, Kazufumi; Ishida, Hisao

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect liver carcinogens, and this assay could be integrated into general toxicological studies. In this study, in order to assess the performance of the assay, cyclophosphamide monohydrate (CP) was tested in a 14-day RDLMN assay. Based on the results of the 4-day repeated dose-finding study, 10 mg/kg/day of CP was selected as the highest dose and the lower doses were set at 5, 2.5, 1.25, and 0.625 mg/kg/day for the 14-day RDLMN assay. On the day after the completion of the dosing period, specimens of hepatocytes and bone marrow cells were prepared and the induction of micronuclei was assessed. No changes were observed in the incidences of micronucleated hepatocytes. Nevertheless, the incidences of micronucleated immature erythrocytes in the bone marrow were increased significantly at CP doses of 1.25 mg/kg/day or more. These findings are consistent with reports that CP induces tumors in various tissues but it does not induce liver tumors.

  2. [Toxicity studies of landiolol hydrochloride (ONO-1101) (2). 4-week repeated dose intravenous toxicity study in rats with 4-week recovery test].

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    Yamaguchi, K; Yanagi, H; Shimizu, K; Sakai, M; Nishibata, K; Oida, H; Shinomiya, K; Suzuki, Y; Yonezawa, H; Fujita, T

    1997-12-01

    4-week repeated dose toxicity study with 4-week recovery test of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley (SD) rats. ONO-1101 was administered intravenously to rats of both sexes at a dose level of 0 (control), 12.5, 25, 50 or 100 mg/kg/day. In the 100 mg/kg/day group, bradypnea or dyspnea was seen in all animals, pale in ear, eye and foot, tremor, reddish lacrimation and loss of righting reflex were also observed in some animals right after administration, and then those signs disappeared within 1 min after administration. During the treatment period, 3/20 animals of each sex in the 100 mg/kg/day showed clonic convulsion and died within 2 min after administration. No clinical changes were seen in the 50 mg/kg/day group or lower. Histopathological findings showed atrophy of the submaxillary gland in females and vessel-wall thickening and perivascular fibrosis of the injection site (tail) in both sexes at 100 mg/kg/day, however those changes were reversible. ONO-1101 did not effect on body weight, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weights or necropsy at any doses. These results indicate that the no-adverse-effect level of ONO-1101 in rats is 50 mg/kg/day for both sexes in this study.

  3. Repeated Dose 28-Days Oral Toxicity Study of Carica papaya L. Leaf Extract in Sprague Dawley Rats

    Directory of Open Access Journals (Sweden)

    Hussin Muhammad

    2012-04-01

    Full Text Available Carica papaya L. leaves have been used in ethnomedicine for the treatment of fevers and cancers. Despite its benefits, very few studies on their potential toxicity have been described. The aim of the present study was to characterize the chemical composition of the leaf extract from ‘Sekaki’ C. papaya cultivar by UPLC-TripleTOF-ESI-MS and to investigate the sub-acute oral toxicity in Sprague Dawley rats at doses of 0.01, 0.14 and 2 g/kg by examining the general behavior, clinical signs, hematological parameters, serum biochemistry and histopathology changes. A total of twelve compounds consisting of one piperidine alkaloid, two organic acids, six malic acid derivatives, and four flavonol glycosides were characterized or tentatively identified in the C. papaya leaf extract. In the sub-acute study, the C. papaya extract did not cause mortality nor were treatment-related changes in body weight, food intake, water level, and hematological parameters observed between treatment and control groups. Some biochemical parameters such as the total protein, HDL-cholesterol, AST, ALT and ALP were elevated in a non-dose dependent manner. Histopathological examination of all organs including liver did not reveal morphological alteration. Other parameters showed non-significant differences between treatment and control groups. The present results suggest that C. papaya leaf extract at a dose up to fourteen times the levels employed in practical use in traditional medicine in Malaysia could be considered safe as a medicinal agent.

  4. Evaluation of repeated dose micronucleus assays of the liver using N-nitrosopyrrolidine: a report of the collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Ogawa, Izumi; Hagioa, Soichiro; Furukawa, Satoshi; Abe, Masayoshi; Kuroda, Yusuke; Hayashi, Seigo; Wako, Yumi; Kawasako, Kazufumi

    2015-03-01

    The repeated dose liver micronucleus (RDLMN) assay has the potential to detect liver carcinogens, and can be integrated into a general toxicological study. To assess the performance of the assay, N-nitrosopyrrolidine (NPYR), a genotoxic hepatocarcinogen, was tested in 14- or 28-day RDLMN assays. NPYR was orally administered to rats at a daily dose of 25, 50 or 100 mg/kg. One day after the last administration, a portion of the liver was removed and hepatocyte micronucleus (MN) specimens were prepared by the new method recently established by Narumi et al. In addition, a bone marrow MN assay and a histopathological examination of the liver were conducted. The detection of Phospho-Histone H3 was performed by immunohistochemistry to evaluate the proliferation rate of hepatocytes. The results showed significant increase in the number of micronucleated hepatocytes and Phospho-Histone H3-positive cells from the lowest dose in both 14- and 28-day RDLMN assays. On the other hand, the bone marrow MN assay yielded a negative result, which was in accordance with the existing report of the bone marrow MN assay using mice. Upon histopathological examination, inflammatory lesions and hypertrophy were noted, which may explain the increase in the hepatocyte proliferation and the enhancement of MN induction by NPYR. Our findings indicate that the RDLMN assay could be a useful tool for comprehensive risk assessment of carcinogenicity by providing information on both genotoxicity and histopathology when integrated into a general repeat dosing toxicity assay.

  5. Study on a 4-Week Recovery Test of Sweet Bee Venom after a 13-Week, Repeated, Intramuscular Dose Toxicity Test in Sprague-Dawley Rats

    Directory of Open Access Journals (Sweden)

    Chungsan Lim

    2014-06-01

    Full Text Available Objectives:This study was performed to check for reversibility in the changes induced by a 13-week, repeated, dose toxicity test of Sweet Bee Venom (SBV in Sprague-Dawley (SD rats. Methods:Fifteen male and 15 female SD rats were treated with 0.28 mg/kg of SBV (high-dosage group and the same numbers of male and female SD rats were treated with 0.2 mL/kg of normal saline (control group for 13 weeks. We selected five male and five female SD rats from the high-dosage group and the same numbers of male and female SD rats from the control group, and we observed these rats for four weeks. We conducted body-weight measurements, ophthalmic examinations, urinalyses and hematology, biochemistry, histology tests. Results:(1 Hyperemia and movement disorder were observed in the 13-week, repeated, dose toxicity test, but these symptoms were not observed during the recovery period. (2 The rats in the high-dose group showed no significant changes in weight compared to the control group. (3 No significant differences in the ophthalmic parameters, urine analyses, complete blood cell counts (CBCs, and biochemistry were observed among the recovery groups. (4 No changes in organ weights were observed during the recovery period. (5 Histological examination of the thigh muscle indicated cell infiltration, inflammation, degeneration, necrosis of muscle fiber, and fibrosis during the treatment period, but these changes were not observed during the recovery period. The fatty liver change that was observed during the toxicity test was not observed during the recovery period. No other organ abnormalities were observed. Conclusion:The changes that occurred during the 13-week, repeated, dose toxicity test are reversible, and SBV can be safely used as a treatment modality.

  6. Physiologic effect of repeated adrenaline (epinephrine) doses during cardiopulmonary resuscitation in the cath lab setting: A randomised porcine study.

    Science.gov (United States)

    Hardig, Bjarne Madsen; Götberg, Michael; Rundgren, Malin; Götberg, Matthias; Zughaft, David; Kopotic, Robert; Wagner, Henrik

    2016-04-01

    This porcine study was designed to explore the effects of repetitive intravenous adrenaline doses on physiologic parameters during CPR. Thirty-six adult pigs were randomised to four injections of: adrenaline 0.02 mg(kgdose)(-1), adrenaline 0.03 mg(kgdose)(-1) or saline control. The effect on systolic, diastolic and mean arterial blood pressure, cerebral perfusion pressure (CePP), end tidal carbon dioxide (ETCO2), arterial oxygen saturation via pulse oximetry (SpO2), cerebral tissue oximetry (SctO2), were analysed immediately prior to each injection and at peak arterial systolic pressure and arterial blood gases were analysed at baseline and after 15 min. In the group given 0.02 mg(kgdose)(-1), there were increases in all arterial blood pressures at all 4 pressure peaks but CePP only increased significantly after peak 1. A decrease in ETCO2 following peak 1 and 2 was observed. SctO2 and SpO2 were lowered following injection 2 and beyond. In the group given a 0.03 mg(kgdose)(-1), all ABP's increased at the first 4 pressure peaks but CePP only following 3 pressure peaks. Lower ETCO2, SctO2 and SpO2 were seen at peak 1 and beyond. In the two adrenaline groups, pH and Base Excess were lower and lactate levels higher compared to baseline as well as compared to the control. Repetitive intravenous adrenaline doses increased ABP's and to some extent also CePP, but significantly decreased organ and brain perfusion. The institutional protocol number: Malmö/Lund Committee for Animal Experiment Ethics, approval reference number: M 192-10. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Evaluation of repeated dose micronucleus assays of the liver and gastrointestinal tract using potassium bromate: a report of the collaborative study by CSGMT/JEMS.MMS.

    Science.gov (United States)

    Okada, Emiko; Fujiishi, Yohei; Narumi, Kazunori; Kado, Shoichi; Wako, Yumi; Kawasako, Kazufumi; Kaneko, Kimiyuki; Ohyama, Wakako

    2015-03-01

    The food additive potassium bromate (KBrO3) is known as a renal carcinogen and causes chromosomal aberrations in vitro without metabolic activation and in vivo in hematopoietic and renal cells. As a part of a collaborative study by the Mammalian Mutagenicity Study group, which is a subgroup of the Japanese Environmental Mutagen Society, we administered KBrO3 to rats orally for 4, 14, and 28 days and examined the micronucleated (MNed) cell frequency in the liver, glandular stomach, colon, and bone marrow to confirm whether the genotoxic carcinogen targeting other than liver and gastrointestinal (GI) tract was detected by the repeated dose liver and GI tract micronucleus (MN) assays. In our study, animals treated with KBrO3 showed some signs of toxicity in the kidney and/or stomach. KBrO3 did not increase the frequency of MNed cells in the liver and colon in any of the repeated dose studies. However, KBrO3 increased the frequency of MNed cells in the glandular stomach and bone marrow. Additionally, the MNed cell frequency in the glandular stomach was not significantly affected by the difference in the length of the administration period. These results suggest that performing the MN assay using the glandular stomach, which is the first tissue to contact agents after oral ingestion, is useful for evaluating the genotoxic potential of chemicals and that the glandular stomach MN assay could be integrated into general toxicity studies. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. A 90-day repeated-dose toxicity study of dietary alpha linolenic acid-enriched diacylglycerol oil in rats.

    Science.gov (United States)

    Bushita, Hiroto; Ito, Yuichi; Saito, Tetsuji; Nukada, Yuko; Ikeda, Naohiro; Nakagiri, Hideaki; Saito, Kazutoshi; Morita, Osamu

    2018-05-31

    Diets supplemented with alpha-linolenic acid (ALA)-enriched diacylglycerol (DAG) oil-which mainly consists of oleic and linolenic, linoleic acids-have potential health benefits in terms of preventing or managing obesity. Although safety of DAG oil has been extensively investigated, toxicity of ALA-DAG oil has not been well understood. Hence, the present study was conducted to clarify the potential adverse effects, if any, of ALA-DAG oil in rats (10/sex/group) fed diets containing 1.375%, 2.75%, or 5.5% ALA-DAG oil for 90 days. Compared to control rats fed rapeseed oil or ALA-triacylglycerol oil (flaxseed oil), rats receiving ALA-DAG oil did not reveal any toxicologically significant treatment-related changes as evaluated by clinical signs, functional observational battery, body weight, food consumption, ophthalmology, urinalysis, hematology, clinical chemistry, organ weight, necropsy and histopathology. The no observed adverse effect levels for dietary exposure to ALA-DAG oil for male and female rats were 2916 and 3326 mg/kg body weight/day, respectively, the highest dose tested. The findings from this study suggest that consumption of ALA-DAG oil is unlikely to cause adverse effects. Copyright © 2018. Published by Elsevier Inc.

  9. Safety of sucrose esters from Physalis peruviana L. in a 28-day repeated-dose study in mice.

    Science.gov (United States)

    Ocampo, Yanet C; Caro, Daneiva C; Rivera, David E; Franco, Luis A

    2017-06-01

    Although extracts and consumed foods from Physalis species contain sucrose esters from their glandular trichomes, there is no experimental data available on their toxicological effects. As peruvioses A and B isolated from Physalis peruviana L. calyces have proved to be effective anti-inflammatory and immunomodulatory compounds, this work aimed to investigate their sub-acute toxicity study and genotoxicity. For this, CD-1(ICR) mice were treated intraperitoneally with peruvioses at doses of 2.5, 5, and 10mg/kg/day for 28 consecutive days, to simulate therapeutic and over-therapeutic dosage levels. At the end of the treatment, animals were sacrificed and their organs weighted, and blood and tissue samples were collected. Toxicological endpoints included clinical signs; food consumption; body and organ weights; hematological and biochemical parameters; as well as macroscopic and microscopic examination of tissues. The results showed no significant differences between treated animals and control group at macroscopic, histological, molecular, and biochemical levels. In addition, a combination of mammalian erythrocyte micronucleus test, comet assay in peripheral blood cells, and Ames test, did not reveal genotoxic effects induced by peruvioses. Taken together, our data suggests that peruvioses A and B can be safely employed to treat inflammatory diseases. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Synthetic food coloring and behavior: a dose response effect in a double-blind, placebo-controlled, repeated-measures study.

    Science.gov (United States)

    Rowe, K S; Rowe, K J

    1994-11-01

    To establish whether there is an association between the ingestion of synthetic food colorings and behavioral change in children referred for assessment of "hyperactivity." From approximately 800 children referred to the Royal Children's Hospital (Melbourne) for assessment of suspected hyperactivity, 200 were included in a 6-week open trial of a diet free of synthetic food coloring. The parents of 150 children reported behavioral improvement with the diet, and deterioration on the introduction of foods noted to contain synthetic coloring. A 30-item behavioral rating inventory was devised from an examination of the clinical histories of 50 suspected reactors. Thirty-four other children (23 suspected reactors, 11 uncertain reactors) and 20 control subjects, aged 2 to 14 years, were studied. A 21-day, double-blind, placebo-controlled, repeated-measures study used each child as his or her own control. Placebo, or one of six dose levels of tartrazine (1, 2, 5, 10, 20, 50 mg), was administered randomly each morning, and behavioral ratings were recorded by parents at the end of each 24 hours. The study identified 24 children as clear reactors (19 of 23 "suspected reactors," 3 of 11 "uncertain reactors," and 2 of 20 "control subjects"). They were irritable and restless and had sleep disturbance. Significant reactions were observed at all six dose levels. A dose response effect was obtained. With a dose increase greater than 10 mg, the duration of effect was prolonged. Behavioral changes in irritability, restlessness, and sleep disturbance are associated with the ingestion of tartrazine in some children. A dose response effect was observed.

  11. Predicting in vivo effect levels for repeat-dose systemic toxicity using chemical, biological, kinetic and study covariates.

    Science.gov (United States)

    Truong, Lisa; Ouedraogo, Gladys; Pham, LyLy; Clouzeau, Jacques; Loisel-Joubert, Sophie; Blanchet, Delphine; Noçairi, Hicham; Setzer, Woodrow; Judson, Richard; Grulke, Chris; Mansouri, Kamel; Martin, Matthew

    2018-02-01

    In an effort to address a major challenge in chemical safety assessment, alternative approaches for characterizing systemic effect levels, a predictive model was developed. Systemic effect levels were curated from ToxRefDB, HESS-DB and COSMOS-DB from numerous study types totaling 4379 in vivo studies for 1247 chemicals. Observed systemic effects in mammalian models are a complex function of chemical dynamics, kinetics, and inter- and intra-individual variability. To address this complex problem, systemic effect levels were modeled at the study-level by leveraging study covariates (e.g., study type, strain, administration route) in addition to multiple descriptor sets, including chemical (ToxPrint, PaDEL, and Physchem), biological (ToxCast), and kinetic descriptors. Using random forest modeling with cross-validation and external validation procedures, study-level covariates alone accounted for approximately 15% of the variance reducing the root mean squared error (RMSE) from 0.96 log 10 to 0.85 log 10  mg/kg/day, providing a baseline performance metric (lower expectation of model performance). A consensus model developed using a combination of study-level covariates, chemical, biological, and kinetic descriptors explained a total of 43% of the variance with an RMSE of 0.69 log 10  mg/kg/day. A benchmark model (upper expectation of model performance) was also developed with an RMSE of 0.5 log 10  mg/kg/day by incorporating study-level covariates and the mean effect level per chemical. To achieve a representative chemical-level prediction, the minimum study-level predicted and observed effect level per chemical were compared reducing the RMSE from 1.0 to 0.73 log 10  mg/kg/day, equivalent to 87% of predictions falling within an order-of-magnitude of the observed value. Although biological descriptors did not improve model performance, the final model was enriched for biological descriptors that indicated xenobiotic metabolism gene expression, oxidative stress, and

  12. Collaborative work on evaluation of ovarian toxicity. 13) Two- or four-week repeated dose studies and fertility study of PPAR alpha/gamma dual agonist in female rats.

    Science.gov (United States)

    Sato, Norihiro; Uchida, Keisuke; Nakajima, Mikio; Watanabe, Atsushi; Kohira, Terutomo

    2009-01-01

    The main focus of this study was to determine the optimal dosing period in a repeated dose toxicity study based on toxic effects as assessed by ovarian morphological changes. To assess morphological and functional changes induced in the ovary by a peroxisome proliferator-activated receptor (PPAR) alpha/gamma dual agonist, the compound was administered to female rats at dose levels of 0, 4, 20, and 100 mg/kg/day in a repeated dose toxicity study for 2 or 4 weeks, and from 2 weeks prior to mating to Day 7 of pregnancy in a female fertility study. In the repeated dose toxicity study, an increase in atresia of large follicles, a decrease in corpora lutea, and an increase in stromal cells were observed in the treated groups. In addition, the granulosa cell exfoliations into antrum of large follicles and corpora lutea with retained oocyte are morphological characteristics induced by this compound, and they might be related with abnormal condition of ovulation. In the female fertility study, the pregnancy rate tended to decrease in the 100 mg/kg/day group. At necropsy, decreases in the number of corpora lutea, implantations and live embryos were noted in the 20 and 100 mg/kg/day group. No changes were observed in animals given 4 mg/kg/day. These findings indicated that histopathological changes in the ovary are important endpoints for evaluation of drugs inducing ovarian damage. In conclusion, a 2-week administration period is sufficient to detect ovarian toxicity of this test compound in the repeated dose toxicity study.

  13. Antithrombotic effect of repeated doses of the ethanolic extract of ...

    African Journals Online (AJOL)

    Antithrombotic effect of repeated doses of the ethanolic extract of local olive ( Olea europaea L.) leaves in rabbits. ... The incidence of thromboembolic diseases is increasing, and they are a major cause of mortality and morbidity worldwide. Mediterranean diet is known for its high content of olive products, especially olive oil, ...

  14. Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 22). Effects of 2- and 4-week administration of theobromine on the testis.

    Science.gov (United States)

    Funabashi, H; Fujioka, M; Kohchi, M; Tateishi, Y; Matsuoka, N

    2000-10-01

    The effects of theobromine, a xanthine derivative, on the testis were compared between rats dosed for 2 and 4 weeks to determine whether a 2-week dosing period is long enough to detect toxicity. Theobromine was administered orally to male Sprague-Dawley rats at dose levels of 250 and 500 mg/kg for 2 weeks starting at the age of 6 or 8 weeks, and for 4 weeks from the age of 6 weeks. Histopathological examination of reproductive organs revealed toxic findings in the testis at 500 mg/kg after 2 weeks of dosing at both ages, and at 250 and 500 mg/kg after 4 weeks of dosing. The primary findings were degeneration/necrosis and desquamation of spermatids and spermatocytes, vacuolization of seminiferous tubules, and multinucleated giant cell formation. These findings were present mainly in stages I-VI and XII-XIV. From these results, it is concluded that the toxic effects of theobromine on the testis can be detected by repeated dosing for 2 weeks as well as for 4 weeks.

  15. Pharmacology of ayahuasca administered in two repeated doses.

    Science.gov (United States)

    Dos Santos, Rafael G; Grasa, Eva; Valle, Marta; Ballester, Maria Rosa; Bouso, José Carlos; Nomdedéu, Josep F; Homs, Rosa; Barbanoj, Manel J; Riba, Jordi

    2012-02-01

    Ayahuasca is an Amazonian tea containing the natural psychedelic 5-HT(2A/2C/1A) agonist N,N-dimethyltryptamine (DMT). It is used in ceremonial contexts for its visionary properties. The human pharmacology of ayahuasca has been well characterized following its administration in single doses. To evaluate the human pharmacology of ayahuasca in repeated doses and assess the potential occurrence of acute tolerance or sensitization. In a double-blind, crossover, placebo-controlled clinical trial, nine experienced psychedelic drug users received PO the two following treatment combinations at least 1 week apart: (a) a lactose placebo and then, 4 h later, an ayahuasca dose; and (b) two ayahuasca doses 4 h apart. All ayahuasca doses were freeze-dried Amazonian-sourced tea encapsulated to a standardized 0.75 mg DMT/kg bodyweight. Subjective, neurophysiological, cardiovascular, autonomic, neuroendocrine, and cell immunity measures were obtained before and at regular time intervals until 12 h after first dose administration. DMT plasma concentrations, scores in subjective and neurophysiological variables, and serum prolactin and cortisol were significantly higher after two consecutive doses. When effects were standardized by plasma DMT concentrations, no differences were observed for subjective, neurophysiological, autonomic, or immunological effects. However, we observed a trend to reduced systolic blood pressure and heart rate, and a significant decrease for growth hormone (GH) after the second ayahuasca dose. Whereas there was no clear-cut tolerance or sensitization in the psychological sphere or most physiological variables, a trend to lower cardiovascular activation was observed, together with significant tolerance to GH secretion.

  16. Repeated dose 28-day oral toxicity study in Wistar rats with a mixture of five pesticides often found as residues in food: alphacypermethrin, bromopropylate, carbendazim, chlorpyrifos and mancozeb

    DEFF Research Database (Denmark)

    Jacobsen, H.; Østergaard, G.; Lam, Henrik Rye

    2004-01-01

    Six dose groups of 8 male and female rats respectively received a daily dose equivalent to 0, 0.15, 0.006, 0.03, 0.15 or 0.3 mg/kg b.w./day chlorpyrifos (groups 1-6) and the last four dose groups (groups 3-6) received in addition daily doses equivalent to 18 mg/kg b.w./day alphacypermethrin, 30 mg...... of acetylcholinesterase activity in plasma and brain by chlorpyrifos was not enhanced by coadministration of the other four pesticides. Effects were seen in liver, thyroid, thymus and blood in the combination groups. However, identification of the pesticide(s) responsible for these changes would require further studies...

  17. Study of the intervention effect of Laminaria japonica polysaccharides on testis tissue in male rats exposed by repeated low-dose ionizing radiation

    International Nuclear Information System (INIS)

    Liu Jun; Luo Qiong; Cui Xiaoyan; Yang Mingliang; Yan Jun

    2010-01-01

    Objective: To investigate the effect of the Laminaria japonica polysaccharides (LJP) intervention on the male rats' testicular tissue oxidative damage which was caused by repeated low-dose local ionizing radiation. Methods: Male Wistar rats were randomly divided into control group, model group and LJP intervention group. The rats in the LJP intervention group was given with LJP. The rats in each group were exposed to 60 Co γ-ray local irradiation 7 d after adaptability breeding, once per day for 20 times in 4 weeks. Each rat was irradiated with the total dose of 2.3 Gy. The rats were killed at 1, 7 and 14 d post-irradiation, respectively. The testis and the epididymis were taken out. The contents of MDA and GSH, and the activities of SOD, LDH and GSH-Px were measured using spectrophotometer. The amorphous of testicular tissue was observed and the sperm count and viability were analyzed. Results: As compared with those in the model group, the content of MDA decreased in testicular tissue in the LJP group (t=3.66-5.03, P<0.01), while the GSH content increased. The activities of SOD, LDH and GSH-Px (t=2.77-25.52, P<0.05) and the sperm count and viability increased (t=3.11-23.08, P<0.01). Each index was more close to that in the control group 14 d post-irradiation. Conclusions: LJP can promote the recovery of testicular tissue oxidative damage caused by chronic local ionizing radiation. It has a role in promoting the spermatogenic function of male rate. (authors)

  18. A 13-week repeated dose study of three 3-monochloropropane-1,2-diol fatty acid esters in F344 rats.

    Science.gov (United States)

    Onami, Saeko; Cho, Young-Man; Toyoda, Takeshi; Mizuta, Yasuko; Yoshida, Midori; Nishikawa, Akiyoshi; Ogawa, Kumiko

    2014-04-01

    3-monochloropropane-1,2-diol (3-MCPD), a rat renal and testicular carcinogen, has been reported to occur in various foods and food ingredients as free or esterified forms. Since reports about toxicity of 3-MCPD esters are limited, we conducted a 13-week rat subchronic toxicity study of 3-MCPD esters (palmitate diester: CDP, palmitate monoester: CMP, oleate diester: CDO). We administered a carcinogenic dose (3.6 × 10(-4) mol/kg B.W./day) of 3-MCPD or these esters at equimolar concentrations and two 1/4 lower doses by gavage with olive oil as a vehicle five times a week for 13 weeks to F344 male and female rats. As a result, five out of ten 3-MCPD-treated females died from acute renal tubular necrosis, but none of the ester-treated rats. Decreased HGB was observed in all high-dose 3-MCPD fatty acid ester-treated rats, except CDO-treated males. The absolute and relative kidney weights were significantly increased in the ester-treated rats at medium and high doses. Relative liver weights were significantly increased in the esters-treated rat at high dose, except for CMP females. Significant increase in apoptotic epithelial cells in the initial segment of the epididymis of high-dose ester-treated males was also observed. The results suggested that although acute renal toxicity was lower than 3-MCPD, these three 3-MCPD fatty acid esters have the potential to exert subchronic toxicity to the rat kidneys and epididymis, to a similar degree as 3-MCPD under the present conditions. NOAELs (no-observed-adverse-effect levels) of CDP, CMP and CDO were suggested to be 14, 8 and 15 mg/kg B.W./day, respectively.

  19. Drug- not carrier-dependent haematological and biochemical changes in a repeated dose study of cyclosporine encapsulated polyester nano- and micro-particles: Size does not matter

    International Nuclear Information System (INIS)

    Venkatpurwar, V.P.; Rhodes, S.; Oien, K.A.; Elliott, M.A.; Tekwe, C.D.; Jørgensen, H.G.; Kumar, M.N.V. Ravi

    2015-01-01

    Highlights: • The particulate delivery allows an increase in dose range without accrual of toxicities. • The altered haematological and biochemical changes are drug, but not particle dependent. • PLGA nano/microparticles are safe on subacute peroral dosing over 28 days. • Nano-toxicology, drug needs to be considered. - Abstract: Biodegradable nanoparticles are being considered more often as drug carriers to address pharmacokinetic/pharmacodynamic issues, yet nano-product safety has not been systematically proven. In this study, haematological, biochemical and histological parameters were examined on 28 day daily dosing of rats with nano- or micro-particle encapsulated cyclosporine (CsA) to confirm if any changes observed were drug or carrier dependent. CsA encapsulated poly(lactide-co-glycolide) [PLGA] nano- (nCsA) and micro-particles (mCsA) were prepared by emulsion techniques. CsA (15, 30, 45 mg/kg) were administered by oral gavage to Sprague Dawley (SD) rats over 28 days. Haematological and biochemical metrics were followed with tissue histology performed on sacrifice. Whether presented as nCsA or mCsA, 45 mg/kg dose caused significant loss of body weight and lowered food consumption compared to untreated control. Across the doses, both nCsA and mCsA produce significant decreases in lymphocyte numbers compared to controls, commensurate with the proprietary product, Neoral ® 15. Dosing with nCsA showed higher serum drug levels than mCsA presumably owing to the smaller particle size facilitating absorption. The treatment had no noticeable effects on inflammatory/oxidative stress markers or antioxidant enzyme levels, except an increase in ceruloplasmin (CP) levels for high dose nCsA/mCsA group. Further, only subtle, sub-lethal changes were observed in histology of nCsA/mCsA treated rat organs. Blank (drug-free) particles did not induce changes in the parameters studied. Therefore, it is extremely important that the encapsulated drug in the nano-products is

  20. The effects of repeated low-dose sarin exposure

    International Nuclear Information System (INIS)

    Shih, T.-M.; Hulet, S.W.; McDonough, J.H.

    2006-01-01

    This project assessed the effects of repeated low-dose exposure of guinea pigs to the organophosphorus nerve agent sarin. Animals were injected once a day, 5 days per week (Monday-Friday), for 2 weeks with fractions (0.3x, 0.4x, 0.5x, or 0.6x) of the established LD 5 dose of sarin (42 μg/kg, s.c.). The animals were assessed for changes in body weight, red blood cell (RBC) acetylcholinesterase (AChE) levels, neurobehavioral reactions to a functional observational battery (FOB), cortical electroencephalographic (EEG) power spectrum, and intrinsic acetylcholine (ACh) neurotransmitter (NT) regulation over the 2 weeks of sarin exposure and for up to 12 days postinjection. No guinea pig receiving 0.3, 0.4 or 0.5 x LD 5 of sarin showed signs of cortical EEG seizures despite decreases in RBC AChE levels to as low as 10% of baseline, while seizures were evident in animals receiving 0.6 x LD 5 of sarin as early as the second day; subsequent injections led to incapacitation and death. Animals receiving 0.5 x LD 5 sarin showed obvious signs of cholinergic toxicity; overall, 2 of 13 animals receiving 0.5 x LD 5 sarin died before all 10 injections were given, and there was a significant increase in the angle of gait in the animals that lived. By the 10th day of injection, the animals receiving saline were significantly easier to remove from their cages and handle and significantly less responsive to an approaching pencil and touch on the rump in comparison with the first day of testing. In contrast, the animals receiving 0.4 x LD 5 sarin failed to show any significant reductions in their responses to an approaching pencil and a touch on the rump as compared with the first day. The 0.5 x LD 5 sarin animals also failed to show any significant changes to the approach and touch responses and did not adjust to handling or removal from the cage from the first day of injections to the last day of handling. Thus, the guinea pigs receiving the 0.4 and 0.5 x LD 5 doses of sarin failed to

  1. Argemone oil, an edible oil adulterant, induces systemic immunosuppression in Balb/c mice in an oral 28 days repeated dose toxicity study.

    Science.gov (United States)

    Mandal, Payal; Tewari, Prachi; Kumar, Sachin; Yadav, Sarika; Ayanur, Anjaneya; Chaturvedi, Rajnish K; Das, Mukul; Tripathi, Anurag

    2018-05-01

    Consumption of edible oils contaminated with Argemone oil (AO) leads to a clinical condition called "Epidemic dropsy". Earlier studies have reported that metabolism and oxidative stress primarily contributes to AO toxicity, however, the involvement of immune system has not been assessed so far. Therefore, the present study was undertaken to systematically assess the effect of AO exposure on the function of immune system in Balb/c mice. The repeated exposure of AO for 28 days caused prominent regression of spleen and thymus; severe inflammatory changes in spleen depicted by the loss of distinct follicles, increased megakaryocyte infiltration, and enhanced expression levels of inflammatory markers (iNOS & COX-2). At the functional level, AO exposure significantly abrogated the mixed lymphocyte reaction and mitogen-stimulated lymphoproliferative activity of T and B cells, which is reflective of profound lymphocyte dysfunction upon antigen exposure. In concordance with the loss in functional activity of lymphocytes in AO exposed animals, it was found the AO altered the relative percentage of CD3 + , CD4 + , and CD28  +  T cells. Further, there was a marked decrease in the relative distribution of cells with prominent MHC I and CD1d expression in AO exposed splenocytes. Moreover, reduced levels of immune stimulatory cytokines (TNF-α, IFN-γ, IL-2, IL-4, and IL-6), and increased levels of immunosuppressive cytokine IL-10 were detected in the serum of AO treated mice. Along with T and B cells, AO exposure also affected the phenotype and activation status of macrophages suggesting the inclination towards "alternative activation of macrophages". Altogether, these functional changes in the immune cells are contributing factors in AO induced immunosuppression. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Long-term Outcomes With Planned Multistage Reduced Dose Repeat Stereotactic Radiosurgery for Treatment of Inoperable High-Grade Arteriovenous Malformations: An Observational Retrospective Cohort Study.

    Science.gov (United States)

    Marciscano, Ariel E; Huang, Judy; Tamargo, Rafael J; Hu, Chen; Khattab, Mohamed H; Aggarwal, Sameer; Lim, Michael; Redmond, Kristin J; Rigamonti, Daniele; Kleinberg, Lawrence R

    2017-07-01

    There is no consensus regarding the optimal management of inoperable high-grade arteriovenous malformations (AVMs). This long-term study of 42 patients with high-grade AVMs reports obliteration and adverse event (AE) rates using planned multistage repeat stereotactic radiosurgery (SRS). To evaluate the efficacy and safety of multistage SRS with treatment of the entire AVM nidus at each treatment session to achieve complete obliteration of high-grade AVMs. Patients with high-grade Spetzler-Martin (S-M) III-V AVMs treated with at least 2 multistage SRS treatments from 1989 to 2013. Clinical outcomes of obliteration rate, minor/major AEs, and treatment characteristics were collected. Forty-two patients met inclusion criteria (n = 26, S-M III; n = 13, S-M IV; n = 3, S-M V) with a median follow-up was 9.5 yr after first SRS. Median number of SRS treatment stages was 2, and median interval between stages was 3.5 yr. Twenty-two patients underwent pre-SRS embolization. Complete AVM obliteration rate was 38%, and the median time to obliteration was 9.7 yr. On multivariate analysis, higher S-M grade was significantly associated ( P = .04) failure to achieve obliteration. Twenty-seven post-SRS AEs were observed, and the post-SRS intracranial hemorrhage rate was 0.027 events per patient year. Treatment of high-grade AVMs with multistage SRS achieves AVM obliteration in a meaningful proportion of patients with acceptable AE rates. Lower obliteration rates were associated with higher S-M grade and pre-SRS embolization. This approach should be considered with caution, as partial obliteration does not protect from hemorrhage. Copyright © 2017 by the Congress of Neurological Surgeons

  3. A 28-day repeat dose toxicity study of steroidal glycoalkaloids, alpha-solanine and alpha-chaconine in the Syrian Golden hamster

    DEFF Research Database (Denmark)

    Langkilde, Søren; Mandimika, T.; Schrøder, Malene

    2009-01-01

    of the glycoalkaloids. The Syrian Golden hamster was given daily doses of alpha-solanine and alpha-chaconine by gavage for 28 days. Doses of up to 33.3 mg total glycoalkaloids/kg body weight were applied in ratios of 1:3.7 and 1:70 (alpha-solanine:alpha-chaconine). Administration of the highest doses of both ratios...... intestines of the hamsters administered the highest doses of the glycoalkaloid treatments. In general, more differential gene expression was observed in the epithelial scrapings of the hamsters fed the ratio of 1:3.7. Mostly, pathways involved in lipid and energy metabolism were affected by the ratio of 1:3.7....

  4. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    International Nuclear Information System (INIS)

    Hinzpeter, Ricarda; Sprengel, Kai; Wanner, Guido A.; Mildenberger, Peter; Alkadhi, Hatem

    2017-01-01

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  5. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    Energy Technology Data Exchange (ETDEWEB)

    Hinzpeter, Ricarda, E-mail: Ricarda.Hinzpeter@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland); Sprengel, Kai, E-mail: Kai.Sprengel@usz.ch [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Wanner, Guido A., E-mail: Guido.Wanner@sbk-vs.de [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Department of General Surgery, Schwarzwald-Baar Klinikum, University of Freiburg, Klinikstr. 11, D-78052 Villingen-Schwenningen (Germany); Mildenberger, Peter, E-mail: peter.mildenberger@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, University Hospital of Mainz, Langenbeckstr. 1, D-55131 Mainz (Germany); Alkadhi, Hatem, E-mail: hatem.alkadhi@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland)

    2017-03-15

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  6. Efficacy and safety of various repeat treatment dosing regimens of rituximab in patients with active rheumatoid arthritis: results of a Phase III randomized study (MIRROR)

    NARCIS (Netherlands)

    Rubbert-Roth, Andrea; Tak, Paul P.; Zerbini, Cristiano; Tremblay, Jean-Luc; Carreño, Luis; Armstrong, Gillian; Collinson, Neil; Shaw, Tim M.

    2010-01-01

    Methods. Patients with active RA despite stable MTX (10-25 mg/week) were randomly assigned to one of the three treatment regimens comprising two courses of RTX given 24 weeks apart: 2 x 500 and 2 x 500 mg; 2 x 500 and 2 x 1000 mg (dose escalation); and 2 x 1000 and 2 x 1000 mg. The primary endpoint

  7. Systemic and immunotoxicity of pristine and PEGylated multi-walled carbon nanotubes in an intravenous 28 days repeated dose toxicity study.

    Science.gov (United States)

    Zhang, Ting; Tang, Meng; Zhang, Shanshan; Hu, Yuanyuan; Li, Han; Zhang, Tao; Xue, Yuying; Pu, Yuepu

    2017-01-01

    The numerous increasing use of carbon nanotubes (CNTs) derived from nanotechnology has raised concerns about their biosafety and potential toxicity. CNTs cause immunologic dysfunction and limit the application of CNTs in biomedicine. The immunological responses induced by pristine multi-walled carbon nanotubes (p-MWCNTs) and PEGylated multi-walled carbon nanotubes (MWCNTs-PEG) on BALB/c mice via an intravenous administration were investigated. The results reflect that the p-MWCNTs induced significant increases in spleen, thymus, and lung weight. Mice treated with p-MWCNTs showed altered lymphocyte populations (CD3 + , CD4 + , CD8 + , and CD19 + ) in peripheral blood and increased serum IgM and IgG levels, and splenic macrophage ultrastructure indicated mitochondria swelling. p-MWCNTs inhibited humoral and cellular immunity function and were associated with decreased immune responses against sheep erythrocytes and serum hemolysis level. Natural killer (NK) activity was not modified by two types of MWCNTs. In comparison with two types of MWCNTs, for a same dose, p-MWCNTs caused higher levels of inflammation and immunosuppression than MWCNTs-PEG. The results of immunological function suggested that after intravenous administration with p-MWCNTs caused more damage to systemic immunity than MWCNTs-PEG. Here, we demonstrated that a surface functional modification on MWCNTs reduces their immune perturbations in vivo. The chemistry-modified MWCNTs change their preferred immune response in vivo and reduce the immunotoxicity of p-MWCNTs.

  8. Evaluation of the repeated-dose liver micronucleus assay using N-nitrosomorpholine in young adult rats: report on collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)-Mammalian Mutagenicity Study (MMS) Group.

    Science.gov (United States)

    Hayashi, Aya; Kosaka, Mizuki; Kimura, Aoi; Wako, Yumi; Kawasako, Kazufumi; Hamada, Shuichi

    2015-03-01

    The present study was conducted to evaluate the suitability of a repeated-dose liver micronucleus (LMN) assay in young adult rats as a collaborative study by the Mammalian mutagenicity study (MMS) group. All procedures were performed in accordance with the standard protocols of the MMS Group. Six-week-old male Crl:CD(SD) rats (5 animals/group) received oral doses of the hepatocarcinogen N-nitrosomorpholine (NMOR) at 0 (control), 5, 10, and 30mg/kg/day (10mL/kg) for 14 days. Control animals received vehicle (water). Hepatocytes were collected from the liver 24h after the last dose, and the number of micronucleated hepatocytes (MNHEPs) was determined by microscopy. The number of micronucleated immature erythrocytes (MNIMEs) in the femoral bone marrow was also determined. The liver was examined using histopathologic methods after formalin fixation. The results showed statistically significant and dose-dependent increases in the number of MNHEPs in the liver at doses of 10mg/kg and greater when compared with the vehicle control. However, no significant increase was noted in the number of MNIMEs in the bone marrow at doses of up to 30mg/kg. Histopathology of the liver revealed hypertrophy and single cell necrosis of hepatocytes at doses of 5mg/kg and above. These results showed that the induction of micronuclei by NMOR was detected by the repeated-dose LMN assay, but not by the repeated-dose bone marrow micronucleus assay. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. An Automated Inpatient Split-dose Bowel Preparation System Improves Colonoscopy Quality and Reduces Repeat Procedures.

    Science.gov (United States)

    Yadlapati, Rena; Johnston, Elyse R; Gluskin, Adam B; Gregory, Dyanna L; Cyrus, Rachel; Werth, Lindsay; Ciolino, Jody D; Grande, David P; Keswani, Rajesh N

    2017-07-19

    Inpatient colonoscopy preparations are often inadequate, compromising patient safety and procedure quality, while resulting in greater hospital costs. The aims of this study were to: (1) design and implement an electronic inpatient split-dose bowel preparation order set; (2) assess the intervention's impact upon preparation adequacy, repeated colonoscopies, hospital days, and costs. We conducted a single center prospective pragmatic quasiexperimental study of hospitalized adults undergoing colonoscopy. The experimental intervention was designed using DMAIC (define, measure, analyze, improve, and control) methodology. Prospective data collected over 12 months were compared with data from a historical preintervention cohort. The primary outcome was bowel preparation quality and secondary outcomes included number of repeated procedures, hospital days, and costs. On the basis of a Delphi method and DMAIC process, we created an electronic inpatient bowel preparation order set inclusive of a split-dose bowel preparation algorithm, automated orders for rescue medications, and nursing bowel preparation checks. The analysis data set included 969 patients, 445 (46%) in the postintervention group. The adequacy of bowel preparation significantly increased following intervention (86% vs. 43%; P<0.01) and proportion of repeated procedures decreased (2.0% vs. 4.6%; P=0.03). Mean hospital days from bowel preparation initiation to discharge decreased from 8.0 to 6.9 days (P=0.02). The intervention resulted in an estimated 1-year cost-savings of $46,076 based on a reduction in excess hospital days associated with repeated and delayed procedures. Our interdisciplinary initiative targeting inpatient colonoscopy preparations significantly improved quality and reduced repeat procedures, and hospital days. Other institutions should consider utilizing this framework to improve inpatient colonoscopy value.

  10. Systemic and immunotoxicity of pristine and PEGylated multi-walled carbon nanotubes in an intravenous 28 days repeated dose toxicity study

    Directory of Open Access Journals (Sweden)

    Zhang T

    2017-02-01

    Full Text Available Ting Zhang,1–3 Meng Tang,1–3 Shanshan Zhang,1–3 Yuanyuan Hu,1–3 Han Li,4 Tao Zhang,4 Yuying Xue,1–3 Yuepu Pu1–3 1Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China; 2Jiangsu key Laboratory for Biomaterials and Devices, Southeast University, Nanjing, China; 3Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou, China; 4Department of Material Science and Engineering, National Key Laboratory of Solid State Microstructures, Nanjing University, Nanjing, China Abstract: The numerous increasing use of carbon nanotubes (CNTs derived from nanotechnology has raised concerns about their biosafety and potential toxicity. CNTs cause immunologic dysfunction and limit the application of CNTs in biomedicine. The immunological responses induced by pristine multi-walled carbon nanotubes (p-MWCNTs and PEGylated multi-walled carbon nanotubes (MWCNTs-PEG on BALB/c mice via an intravenous administration were investigated. The results reflect that the p-MWCNTs induced significant increases in spleen, thymus, and lung weight. Mice treated with p-MWCNTs showed altered lymphocyte populations (CD3+, CD4+, CD8+, and CD19+ in peripheral blood and increased serum IgM and IgG levels, and splenic macrophage ultrastructure indicated mitochondria swelling. p-MWCNTs inhibited humoral and cellular immunity function and were associated with decreased immune responses against sheep erythrocytes and serum hemolysis level. Natural killer (NK activity was not modified by two types of MWCNTs. In comparison with two types of MWCNTs, for a same dose, p-MWCNTs caused higher levels of inflammation and immunosuppression than MWCNTs-PEG. The results of immunological function suggested that after intravenous administration with p-MWCNTs caused more damage to systemic immunity than MWCNTs- PEG. Here, we demonstrated that a surface functional modification on MWCNTs reduces

  11. Effect of repeated oral therapeutic doses of methylphenidate on food intake and growth rate in rats.

    Science.gov (United States)

    Alam, Nausheen; Najam, Rahila

    2015-01-01

    Central nervous system stimulants are known to produce anorexia. Previous data suggest that methylphenidate can have variable effects on caloric intake and growth rate. A dose-response study was performed to monitor caloric intake, liquid intake and growth rate in rats following repeated administration of human oral therapeutic doses 2 mg/kg/day, 5mg/kg/day and 8mg/kg/day of methylphenidate. We found that food intake and water intake, increased in all weeks and at all doses used in the study. Growth rate increased more at higher dose (8mg/kg/day) and at low dose (2mg/kg/day) of methylphenidate in 1(st) and 2(nd) week whereas more decreased by the above doses in 3(rd) week, suggesting that food stimulation leads to initial increase in growth rate but long term administration of methylphenidate attenuate growth rate that is not due to modulation of appetite but may be due to anxiety and increased activity produce by stimulants. A possible role of DA, 5HT receptors in modulation of appetite and anxiety is discussed.

  12. Repeat dose of gonadotropin-releasing hormone agonist trigger in polycystic ovarian syndrome undergoing In Vitro fertilization cycles provides a better cycle outcome - a proof-of-concept study

    Directory of Open Access Journals (Sweden)

    Krishna Deepika

    2017-01-01

    Full Text Available Objective: Is a single dose of gonadotropin-releasing hormone agonist (GnRHa trigger to induce final oocyte maturation in polycystic ovarian syndrome (PCOS undergoing in vitro fertilization (IVF cycles with GnRH antagonist protocol sufficient to provide optimal oocyte maturity? Design: This is a prospective, randomized, double-blind, proof-of-concept study. Setting: This study was carried out at a tertiary care center. Material and Methods: A total of 125 patients diagnosed with PCOS defined as per the ESHRE/ASRM Rotterdam criteria (2003 undergoing IVF in antagonist protocol were randomized into two groups. Group A: single dose of GnRHa 0.2 mg, 35 h prior to oocyte retrieval, and Group B: 0.2 mg GnRHa 35 h prior to oocyte retrieval + repeat dose of 0.1 mg 12 h following the 1st dose. 12 h post-trigger, luteinizing hormone (LH, progesterone (P4, and follicle-stimulating hormone (FSH values were estimated. Statistical Analysis: Continuous variables were expressed as mean ± standard deviation and categorical variables as proportions where applicable. Independent sample t-test was used for continuous variables which were normally distributed and Mann–Whitney U-test for data not normally distributed. Chi-square test or Fisher's exact test was used for categorical variables where appropriate. Odds ratio (OR with 95% confidence intervals (CIs was calculated. In addition, receiver operating characteristic curve was used to evaluate the post-trigger LH, P4, and FSH values at 12 h as predictors of oocyte maturity. Main Outcome Measures: Primary outcome: maturity rate of the oocytes. Secondary outcomes: oocyte yield, fertilization rate, availability of good quality embryos on day 3, blastocyst conversion, OHSS rates, post-trigger serum LH (IU/L, FSH (IU/L, and P4 (ng/mL levels implantation rate and clinical pregnancy rate. Results: A higher number of mature (metaphase II oocytes were obtained in Group B compared to Group A (OR of 0.47; CI: 0.38–0

  13. Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability.

    Science.gov (United States)

    Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Dore, Antonio; Aringhieri, Giacomo; Caramella, Davide

    2018-03-01

    To assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose. A series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software. Among the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists' choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them. Our results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.

  14. Repeated-dose effects of mequitazine, cetirizine and dexchlorpheniramine on driving and psychomotor performance.

    Science.gov (United States)

    Theunissen, Eef L; Vermeeren, Annemiek; Ramaekers, Johannes G

    2006-01-01

    Previous studies have demonstrated that the antihistamines mequitazine, cetirizine and dexchlorpheniramine produce mild sedation after single doses. It is unknown, however, whether acute sedation persists after repeated dosing. Therefore, this study assessed the effects of repeated dosing of these antihistamines on driving and psychomotor performance. Sixteen healthy volunteers were treated with mequitazine 10 mg q.a.m., cetirizine 10 mg q.a.m., dexchlorpheniramine Repetab 6 mg b.i.d. and placebo for four separate 8-day periods. Drug effects were assessed on days 1 and 8 using on-the-road driving tests (highway driving and car following), psychomotor tests (tracking and divided attention) and subjective questionnaires. Dexchlorpheniramine and mequitazine significantly impaired driving performance on the highway driving test on the first day; dexchlorpheniramine increased Standard Deviation of Lateral Position by 2 cm [95% confidence interval (CI) 0.5, 3.8] and mequitazine by 2.5 cm (CI 1.0, 4.3). These effects on driving performance disappeared after 8 days of treatment. No effect of treatment was found on car following, tracking and divided attention. Although subjective ratings confirmed that subjects knew their driving had been impaired in the mequitazine and dexchlorpheniramine condition after completion of the highway driving test on day 1, they did not expect their driving to be affected before the start of the test. Cetirizine did not impair performance on any of the tests. Single doses of mequitazine 10 mg and dexchlorpheniramine Repetab 6 mg cause mild driving impairment. However, when taken over several days, the impairing effect wears off, possibly as a result of tolerance.

  15. Antithrombotic effect of repeated doses of the ethanolic extract of ...

    African Journals Online (AJOL)

    2013-05-22

    May 22, 2013 ... extract of local olive (Olea europaea L.) leaves in rabbits. Abdallah M. ... olives have focused on olive oil and a few on olive leaves (OLEs). In this study .... thrombus was carefully removed, blotted on filter paper, and weighed ...

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

    Science.gov (United States)

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

    2006-06-01

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

  17. Utility of repeated praziquantel dosing in the treatment of schistosomiasis in high-risk communities in Africa: a systematic review.

    Directory of Open Access Journals (Sweden)

    Charles H King

    2011-09-01

    Full Text Available Controversy persists about the optimal approach to drug-based control of schistosomiasis in high-risk communities. In a systematic review of published studies, we examined evidence for incremental benefits from repeated praziquantel dosing, given 2 to 8 weeks after an initial dose, in Schistosoma-endemic areas of Africa.We performed systematic searches of electronic databases PubMed and EMBASE for relevant data using search terms 'schistosomiasis', 'dosing' and 'praziquantel' and hand searches of personal collections and bibliographies of recovered articles. In 10 reports meeting study criteria, improvements in parasitological treatment outcomes after two doses of praziquantel were greater for S. mansoni infection than for S. haematobium infection. Observed cure rates (positive to negative conversion in egg detection assays were, for S. mansoni, 69-91% cure after two doses vs. 42-79% after one dose and, for S. haematobium, 46-99% cure after two doses vs. 37-93% after a single dose. Treatment benefits in terms of reduction in intensity (mean egg count were also different for the two species-for S. mansoni, the 2-dose regimen yielded an weighted average 89% reduction in standardized egg counts compared to a 83% reduction after one dose; for S. haematobium, two doses gave a 93% reduction compared to a 94% reduction with a single dose. Cost-effectiveness analysis was performed based on Markov life path modeling.Although schedules for repeated treatment with praziquantel require greater inputs in terms of direct costs and community participation, there are incremental benefits to this approach at an estimated cost of $153 (S. mansoni-$211 (S. haematobium per additional lifetime QALY gained by double treatment in school-based programs. More rapid reduction of infection-related disease may improve program adherence, and if, as an externality of the program, transmission can be reduced through more effective coverage, significant additional benefits are

  18. Human pharmacology of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) after repeated doses taken 4 h apart Human pharmacology of MDMA after repeated doses taken 4 h apart.

    Science.gov (United States)

    Farré, Magí; Tomillero, Angels; Pérez-Mañá, Clara; Yubero, Samanta; Papaseit, Esther; Roset, Pere-Nolasc; Pujadas, Mitona; Torrens, Marta; Camí, Jordi; de la Torre, Rafael

    2015-10-01

    3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is a popular psychostimulant, frequently associated with multiple administrations over a short period of time. Repeated administration of MDMA in experimental settings induces tolerance and metabolic inhibition. The aim is to determine the acute pharmacological effects and pharmacokinetics resulting from two consecutive 100mg doses of MDMA separated by 4h. Ten male volunteers participated in a randomized, double-blind, crossover, placebo-controlled trial. The four conditions were placebo plus placebo, placebo plus MDMA, MDMA plus placebo, and MDMA plus MDMA. Outcome variables included pharmacological effects and pharmacokinetic parameters. After a second dose of MDMA, most effects were similar to those after a single dose, despite a doubling of MDMA concentrations (except for systolic blood pressure and reaction time). After repeated MDMA administration, a 2-fold increase was observed in MDMA plasma concentrations. For a simple dose accumulation MDMA and MDA concentrations were higher (+23.1% Cmax and +17.1% AUC for MDMA and +14.2% Cmax and +10.3% AUC for MDA) and HMMA and HMA concentrations lower (-43.3% Cmax and -39.9% AUC for HMMA and -33.2% Cmax and -35.1% AUC for HMA) than expected, probably related to MDMA metabolic autoinhibition. Although MDMA concentrations doubled after the second dose, most pharmacological effects were similar or slightly higher in comparison to the single administration, except for systolic blood pressure and reaction time which were greater than predicted. The pharmacokinetic-effects relationship suggests that when MDMA is administered at a 4h interval there exists a phenomenon of acute tolerance to its effects. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  19. Evaluation of the repeated-dose liver and gastrointestinal tract micronucleus assays with 22 chemicals using young adult rats: summary of the collaborative study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/The Japanese Environmental Mutagen Society (JEMS) - Mammalian Mutagenicity Study Group (MMS).

    Science.gov (United States)

    Hamada, Shuichi; Ohyama, Wakako; Takashima, Rie; Shimada, Keisuke; Matsumoto, Kazumi; Kawakami, Satoru; Uno, Fuyumi; Sui, Hajime; Shimada, Yasushi; Imamura, Tadashi; Matsumura, Shoji; Sanada, Hisakazu; Inoue, Kenji; Muto, Shigeharu; Ogawa, Izumi; Hayashi, Aya; Takayanagi, Tomomi; Ogiwara, Yosuke; Maeda, Akihisa; Okada, Emiko; Terashima, Yukari; Takasawa, Hironao; Narumi, Kazunori; Wako, Yumi; Kawasako, Kazufumi; Sano, Masaki; Ohashi, Nobuyuki; Morita, Takeshi; Kojima, Hajime; Honma, Masamitsu; Hayashi, Makoto

    2015-03-01

    The repeated-dose liver micronucleus (RDLMN) assay using young adult rats has the potential to detect hepatocarcinogens. We conducted a collaborative study to assess the performance of this assay and to evaluate the possibility of integrating it into general toxicological studies. Twenty-four testing laboratories belonging to the Mammalian Mutagenicity Study Group, a subgroup of the Japanese Environmental Mutagen Society, participated in this trial. Twenty-two model chemicals, including some hepatocarcinogens, were tested in 14- and/or 28-day RDLMN assays. As a result, 14 out of the 16 hepatocarcinogens were positive, including 9 genotoxic hepatocarcinogens, which were reported negative in the bone marrow/peripheral blood micronucleus (MN) assay by a single treatment. These outcomes show the high sensitivity of the RDLMN assay to hepatocarcinogens. Regarding the specificity, 4 out of the 6 non-liver targeted genotoxic carcinogens gave negative responses. This shows the high organ specificity of the RDLMN assay. In addition to the RDLMN assay, we simultaneously conducted gastrointestinal tract MN assays using 6 of the above carcinogens as an optional trial of the collaborative study. The MN assay using the glandular stomach, which is the first contact site of the test chemical when administered by oral gavage, was able to detect chromosomal aberrations with 3 test chemicals including a stomach-targeted carcinogen. The treatment regime was the 14- and/or 28-day repeated-dose, and the regime is sufficiently promising to incorporate these methods into repeated-dose toxicological studies. The outcomes of our collaborative study indicated that the new techniques to detect chromosomal aberrations in vivo in several tissues worked successfully. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Repeat Gamma-Knife Radiosurgery for Refractory or Recurrent Trigeminal Neuralgia with Consideration About the Optimal Second Dose.

    Science.gov (United States)

    Park, Seong-Cheol; Kwon, Do Hoon; Lee, Do Hee; Lee, Jung Kyo

    2016-02-01

    To investigate adequate radiation doses for repeat Gamma Knife radiosurgery (GKS) for trigeminal neuralgia in our series and meta-analysis. Fourteen patients treated by ipsilateral repeat GKS for trigeminal neuralgia were included. Median age of patients was 65 years (range, 28-78), the median target dose, 140-180). Patients were followed a median of 10.8 months (range, 1-151) after the second gamma-knife surgery. Brainstem dose analysis and vote-counting meta-analysis of 19 studies were performed. After the second gamma-knife radiosurgeries, pain was relieved effectively in 12 patients (86%; Barrow Neurological Institute Pain Intensity Score I-III). Post-gamma-knife radiosurgery trigeminal nerve deficits were mild in 5 patients. No serious anesthesia dolorosa was occurred. The second GKS radiation dose ≤ 60 Gy was significantly associated with worse pain control outcome (P = 0.018 in our series, permutation analysis of variance, and P = 0.009 in the meta-analysis, 2-tailed Fisher's exact test). Cumulative dose ≤ 140-150 Gy was significantly associated with poor pain control outcome (P = 0.033 in our series and P = 0.013 in the meta-analysis, 2-tailed Fisher's exact test). A cumulative brainstem edge dose >12 Gy tended to be associated with trigeminal nerve deficit (P = 0.077). Our study suggests that the second GKS dose is a potentially important factor. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. A GPU implementation of a track-repeating algorithm for proton radiotherapy dose calculations

    International Nuclear Information System (INIS)

    Yepes, Pablo P; Mirkovic, Dragan; Taddei, Phillip J

    2010-01-01

    An essential component in proton radiotherapy is the algorithm to calculate the radiation dose to be delivered to the patient. The most common dose algorithms are fast but they are approximate analytical approaches. However their level of accuracy is not always satisfactory, especially for heterogeneous anatomical areas, like the thorax. Monte Carlo techniques provide superior accuracy; however, they often require large computation resources, which render them impractical for routine clinical use. Track-repeating algorithms, for example the fast dose calculator, have shown promise for achieving the accuracy of Monte Carlo simulations for proton radiotherapy dose calculations in a fraction of the computation time. We report on the implementation of the fast dose calculator for proton radiotherapy on a card equipped with graphics processor units (GPUs) rather than on a central processing unit architecture. This implementation reproduces the full Monte Carlo and CPU-based track-repeating dose calculations within 2%, while achieving a statistical uncertainty of 2% in less than 1 min utilizing one single GPU card, which should allow real-time accurate dose calculations.

  2. Preclinical assessment of HIV vaccines and microbicides by repeated low-dose virus challenges.

    Directory of Open Access Journals (Sweden)

    Roland R Regoes

    2005-08-01

    Full Text Available Trials in macaque models play an essential role in the evaluation of biomedical interventions that aim to prevent HIV infection, such as vaccines, microbicides, and systemic chemoprophylaxis. These trials are usually conducted with very high virus challenge doses that result in infection with certainty. However, these high challenge doses do not realistically reflect the low probability of HIV transmission in humans, and thus may rule out preventive interventions that could protect against "real life" exposures. The belief that experiments involving realistically low challenge doses require large numbers of animals has so far prevented the development of alternatives to using high challenge doses.Using statistical power analysis, we investigate how many animals would be needed to conduct preclinical trials using low virus challenge doses. We show that experimental designs in which animals are repeatedly challenged with low doses do not require unfeasibly large numbers of animals to assess vaccine or microbicide success.Preclinical trials using repeated low-dose challenges represent a promising alternative approach to identify potential preventive interventions.

  3. Evaluating the potential of gold, silver, and silica nanoparticles to saturate mononuclear phagocytic system tissues under repeat dosing conditions.

    Science.gov (United States)

    Weaver, James L; Tobin, Grainne A; Ingle, Taylor; Bancos, Simona; Stevens, David; Rouse, Rodney; Howard, Kristina E; Goodwin, David; Knapton, Alan; Li, Xiaohong; Shea, Katherine; Stewart, Sharron; Xu, Lin; Goering, Peter L; Zhang, Qin; Howard, Paul C; Collins, Jessie; Khan, Saeed; Sung, Kidon; Tyner, Katherine M

    2017-07-17

    As nanoparticles (NPs) become more prevalent in the pharmaceutical industry, questions have arisen from both industry and regulatory stakeholders about the long term effects of these materials. This study was designed to evaluate whether gold (10 nm), silver (50 nm), or silica (10 nm) nanoparticles administered intravenously to mice for up to 8 weeks at doses known to be sub-toxic (non-toxic at single acute or repeat dosing levels) and clinically relevant could produce significant bioaccumulation in liver and spleen macrophages. Repeated dosing with gold, silver, and silica nanoparticles did not saturate bioaccumulation in liver or spleen macrophages. While no toxicity was observed with gold and silver nanoparticles throughout the 8 week experiment, some effects including histopathological and serum chemistry changes were observed with silica nanoparticles starting at week 3. No major changes in the splenocyte population were observed during the study for any of the nanoparticles tested. The clinical impact of these changes is unclear but suggests that the mononuclear phagocytic system is able to handle repeated doses of nanoparticles.

  4. Low dose epidemiologic studies

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

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

  5. Repeated low-dose exposures to sarin, soman, or VX affect acoustic startle in guinea pigs.

    Science.gov (United States)

    Smith, C D; Lee, R B; Moran, A V; Sipos, M L

    2016-01-01

    Chemical warfare nerve agents (CWNAs) are known to cause behavioral abnormalities in cases of human exposures and in animal models. The behavioral consequences of single exposures to CWNAs that cause observable toxic signs are particularly well characterized in animals; however, less is known regarding repeated smaller exposures that may or may not cause observable toxic signs. In the current study, guinea pigs were exposed to fractions (0.1, 0.2, or 0.4) of a medial lethal dose (LD50) of sarin, soman, or VX for two weeks. On each exposure day, and for a post-exposure period, acoustic startle response (ASR) was measured in each animal. Although relatively few studies use guinea pigs to measure behavior, this species is ideal for CWNA-related experiments because their levels of carboxylesterases closely mimic those of humans, unlike rats or mice. Results showed that the 0.4 LD50 doses of soman and VX transiently increased peak startle amplitude by the second week of injections, with amplitude returning to baseline by the second week post-exposure. Sarin also increased peak startle amplitude independent of week. Latencies to peak startle and PPI were affected by agent exposure but not consistently among the three agents. Most of the changes in startle responses returned to baseline following the cessation of exposures. These data suggest that doses of CWNAs not known to produce observable toxic signs in guinea pigs can affect behavior in the ASR paradigm. Further, these deficits are transient and usually return to baseline shortly after the end of a two-week exposure period. Published by Elsevier Inc.

  6. Methods for analysing cardiovascular studies with repeated measures

    NARCIS (Netherlands)

    Cleophas, T. J.; Zwinderman, A. H.; van Ouwerkerk, B. M.

    2009-01-01

    Background. Repeated measurements in a single subject are generally more similar than unrepeated measurements in different subjects. Unrepeated analyses of repeated data cause underestimation of the treatment effects. Objective. To review methods adequate for the analysis of cardiovascular studies

  7. [Study of personal best value of peak expiratory flow in patients with asthma--comparison of the highest value of daily PEF under good control and the highest value of daily PEF obtained after using repeated inhaled beta2-agonist during high-dose inhaled steroid treatment].

    Science.gov (United States)

    Watanabe, Naoto; Makino, Sohei; Kihara, Norio; Fukuda, Takeshi

    2008-12-01

    In the guideline for asthma management, it is important to find the personal best value of peak expiratory flow (best PEF). Recently, we have substituted the highest value of PEF in daily life under good control (daily highest PEF) for the best PEF. In the present study, we considered whether the daily highest PEF could be used as the best PEF or not. Subjects were 30 asthmatics who were well controlled but whose baseline PEF values were less than 80 percent of predicted values. We compared the daily highest PEF and the highest of PEF obtained after repeated inhaled beta2-agonist (salbutamol MDI every 20 minutes three times). All subjects then received 1600 microg/day of beclomethasone dipropionate (BDP) for 4 to 8 weeks. We studied the effect of high-dose inhaled steroid treatment on each PEF value and compared the daily highest PEF and the highest PEF obtained after using repeated salbutamol MDI during high dose inhaled steroid therapy on the examination day again. The baseline PEF, daily highest PEF and the highest PEF obtained after salbutamol MDI were significantly less than the each values obtained after high-dose BDP. The best PEF value of them was the value obtained after repeated salbutamol MDI during high dose BDP. We suggest that the daily highest PEF under good control is not a substitute for best PEF because it changes according to the degree of improvement of airway inflammation. We recommend that a course of high dose inhaled steroid is effective in finding the best value of PEF for each individual with moderate asthma.

  8. Cognitive enhancement and antipsychotic-like activity following repeated dosing with the selective M4 PAM VU0467154.

    Science.gov (United States)

    Gould, Robert W; Grannan, Michael D; Gunter, Barak W; Ball, Jacob; Bubser, Michael; Bridges, Thomas M; Wess, Jurgen; Wood, Michael W; Brandon, Nicholas J; Duggan, Mark E; Niswender, Colleen M; Lindsley, Craig W; Conn, P Jeffrey; Jones, Carrie K

    2018-01-01

    Although selective activation of the M 1 muscarinic acetylcholine receptor (mAChR) subtype has been shown to improve cognitive function in animal models of neuropsychiatric disorders, recent evidence suggests that enhancing M 4 mAChR function can also improve memory performance. Positive allosteric modulators (PAMs) targeting the M 4 mAChR subtype have shown therapeutic potential for the treatment of multiple symptoms observed in schizophrenia, including positive and cognitive symptoms when assessed in acute preclinical dosing paradigms. Since the cholinergic system has been implicated in multiple stages of learning and memory, we evaluated the effects of repeated dosing with the highly selective M 4 PAM VU0467154 on either acquisition and/or consolidation of learning and memory when dosed alone or after pharmacologic challenge with the N-methyl-d-aspartate subtype of glutamate receptors (NMDAR) antagonist MK-801. MK-801 challenge represents a well-documented preclinical model of NMDAR hypofunction that is thought to underlie some of the positive and cognitive symptoms observed in schizophrenia. In wildtype mice, 10-day, once-daily dosing of VU0467154 either prior to, or immediately after daily testing enhanced the rate of learning in a touchscreen visual pairwise discrimination task; these effects were absent in M 4 mAChR knockout mice. Following a similar 10-day, once-daily dosing regimen of VU0467154, we also observed 1) improved acquisition of memory in a cue-mediated conditioned freezing paradigm, 2) attenuation of MK-801-induced disruptions in the acquisition of memory in a context-mediated conditioned freezing paradigm and 3) reversal of MK-801-induced hyperlocomotion. Comparable efficacy and plasma and brain concentrations of VU0467154 were observed after repeated dosing as those previously reported with an acute, single dose administration of this M 4 PAM. Together, these studies are the first to demonstrate that cognitive enhancing and antipsychotic

  9. Dose-to-man studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Dose-to-Man Studies focused on developing computer data handling and computer modules which permit easy, rapid assessment of the dose to southeastern United States populations from routine or accidental releases of radionuclides to atmospheric and stream systems

  10. Bioequivalence and Safety of Twice-Daily Sustained-Release Paracetamol (Acetaminophen) Compared With 3- and 4-Times-Daily Paracetamol: A Repeat-Dose, Crossover Pharmacokinetic Study in Healthy Volunteers.

    Science.gov (United States)

    Liu, Dongzhou J; Collaku, Agron

    2018-01-01

    Twice-daily sustained-release (SR) paracetamol (acetaminophen) offers convenient administration to chronic users. This study investigated at steady state (during the last 24 hours of a 3-day dosing period) the pharmacokinetics, bioequivalence, and safety of twice-daily SR paracetamol compared with extended-release (ER) and immediate-release (IR) paracetamol. In this open-label, randomized, multidose, 3-way crossover study, 28 healthy subjects received paracetamol SR (2 × 1000 mg twice daily), ER (2 × 665 mg 3 times daily), and IR (2 × 500 mg 4 times daily). At steady state, twice-daily SR paracetamol was bioequivalent to ER and IR paracetamol. The 90% confidence intervals for the ratios of geometric means were within the acceptance interval for SR/ER paracetamol (AUC 0-t , 0.973-1.033; AUC 0-24 , 0.974-1.034; AUC 0-∞ , 0.948-1.011; C max , 1.082-1.212; C av , 1.011-1.106) and SR/IR paracetamol (AUC 0-t , 0.969-1.029; AUC 0-24 , 0.968-1.027; AUC 0-∞ , 0.963-1.026; C max , 0.902-1.010; C av , 1.004-1.098). Given twice daily, the SR formulation demonstrated SR properties as expected. Mean time at or above a 4 μg/mL plasma concentration of paracetamol from 2 daily doses of the SR formulation was significantly longer than that from 4 daily doses of IR paracetamol. SR formulation also had a greater T max , a longer half-life, and lower C min compared with ER and IR paracetamol. All formulations were well tolerated. © 2017, The American College of Clinical Pharmacology.

  11. Bile Salt Homeostasis in Normal and Bsep Gene Knockout Rats with Single and Repeated Doses of Troglitazone.

    Science.gov (United States)

    Cheng, Yaofeng; Chen, Shenjue; Freeden, Chris; Chen, Weiqi; Zhang, Yueping; Abraham, Pamela; Nelson, David M; Humphreys, W Griffith; Gan, Jinping; Lai, Yurong

    2017-09-01

    The interference of bile acid secretion through bile salt export pump (BSEP) inhibition is one of the mechanisms for troglitazone (TGZ)-induced hepatotoxicity. Here, we investigated the impact of single or repeated oral doses of TGZ (200 mg/kg/day, 7 days) on bile acid homoeostasis in wild-type (WT) and Bsep knockout (KO) rats. Following oral doses, plasma exposures of TGZ were not different between WT and KO rats, and were similar on day 1 and day 7. However, plasma exposures of the major metabolite, troglitazone sulfate (TS), in KO rats were 7.6- and 9.3-fold lower than in WT on day 1 and day 7, respectively, due to increased TS biliary excretion. With Bsep KO, the mRNA levels of multidrug resistance-associated protein 2 (Mrp2), Mrp3, Mrp4, Mdr1, breast cancer resistance protein (Bcrp), sodium taurocholate cotransporting polypeptide, small heterodimer partner, and Sult2A1 were significantly altered in KO rats. Following seven daily TGZ treatments, Cyp7A1 was significantly increased in both WT and KO rats. In the vehicle groups, plasma exposures of individual bile acids demonstrated variable changes in KO rats as compared with WT. WT rats dosed with TGZ showed an increase of many bile acid species in plasma on day 1, suggesting the inhibition of Bsep. Conversely, these changes returned to base levels on day 7. In KO rats, alterations of most bile acids were observed after seven doses of TGZ. Collectively, bile acid homeostasis in rats was regulated through bile acid synthesis and transport in response to Bsep deficiency and TGZ inhibition. Additionally, our study is the first to demonstrate that repeated TGZ doses can upregulate Cyp7A1 in rats. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  12. A single whole-body low dose X-irradiation does not affect L1, B1 and IAP repeat element DNA methylation longitudinally.

    Directory of Open Access Journals (Sweden)

    Michelle R Newman

    Full Text Available The low dose radioadaptive response has been shown to be protective against high doses of radiation as well as aging-induced genomic instability. We hypothesised that a single whole-body exposure of low dose radiation would induce a radioadaptive response thereby reducing or abrogating aging-related changes in repeat element DNA methylation in mice. Following sham or 10 mGy X-irradiation, serial peripheral blood sampling was performed and differences in Long Interspersed Nucleic Element 1 (L1, B1 and Intracisternal-A-Particle (IAP repeat element methylation between samples were assessed using high resolution melt analysis of PCR amplicons. By 420 days post-irradiation, neither radiation- or aging-related changes in the methylation of peripheral blood, spleen or liver L1, B1 and IAP elements were observed. Analysis of the spleen and liver tissues of cohorts of untreated aging mice showed that the 17-19 month age group exhibited higher repeat element methylation than younger or older mice, with no overall decline in methylation detected with age. This is the first temporal analysis of the effect of low dose radiation on repeat element methylation in mouse peripheral blood and the first to examine the long term effect of this dose on repeat element methylation in a radiosensitive tissue (spleen and a tissue fundamental to the aging process (liver. Our data indicate that the methylation of murine DNA repeat elements can fluctuate with age, but unlike human studies, do not demonstrate an overall aging-related decline. Furthermore, our results indicate that a low dose of ionising radiation does not induce detectable changes to murine repeat element DNA methylation in the tissues and at the time-points examined in this study. This radiation dose is relevant to human diagnostic radiation exposures and suggests that a dose of 10 mGy X-rays, unlike high dose radiation, does not cause significant short or long term changes to repeat element or global DNA

  13. Oral repeated-dose systemic and reproductive toxicity of 6:2 fluorotelomer alcohol in mice

    Directory of Open Access Journals (Sweden)

    Pushkor Mukerji

    2015-01-01

    Full Text Available 6:2 fluorotelomer alcohol (6:2 FTOH was evaluated for potential systemic repeated-dose and reproductive toxicity in mice. 6:2 FTOH was administered by oral gavage to CD-1 mice as a suspension in 0.5% aqueous methylcellulose with 0.1% Tween-80 at dosages of 1, 5, 25, or 100 mg/kg/day. The no-observed-adverse-effect level (NOAEL for systemic toxicity was 25 mg/kg/day (males and 5 mg/kg/day (females, based on effects at higher doses on mortality, clinical observations, body weight, nutritional parameters, hematology (red and white blood cell, clinical chemistry (liver-related, liver weights, and histopathology (liver, teeth, reproductive tract, and mammary gland. However, 6:2 FTOH was not a selective reproductive toxicant. The NOAEL for reproductive toxicity was >100 mg/kg/day; no effects on reproductive outcome were observed at any dosage. The NOAEL for viability and growth of the offspring was 25 mg/kg/day, based on clinical signs of delayed maturation in pups, and reductions in pup survival and pup body weight during lactation at 100 mg/kg/day. While the severity of the effects was generally greater in mice than previously reported in CD rats, the overall NOAELs were identical in both species, 5 mg/kg/day for systemic toxicity and 25 mg/kg/day for offspring viability/growth. 6:2 FTOH was not a selective reproductive toxicant in either species; no effects on reproductive outcome occurred at any dose level, and any effects observed in offspring occurred at dose levels that induced mortality and severe toxicity in maternal animals.

  14. Studies on Section XI ultrasonic repeatability

    International Nuclear Information System (INIS)

    Jamison, T.D.; McDearman, W.R.

    1981-05-01

    A block representative of a nuclear component has been welded containing intentional defects. Acoustic emission data taken during the welding correlate well with ultrasonic data. Repetitive ultrasonic examinations have been performed by skilled operators using a procedure based on that desribed in ASME Section XI. These examinations were performed by different examination teams using different ultrasonic equipment in such a manner that the effects on the repeatability of the ultrasonic test method caused by the operator and by the use of different equipment could be estimated. It was tentatively concluded that when considering a large number of inspections: (1) there is no significant difference in indication sizing between operators, and (2) there is a significant difference in amplitude and defect sizing when instruments having different, Code acceptable operating characteristics are used. It was determined that the Section XI sizing parameters follow a bivariate normal distribution. Data derived from ultrasonically and physically sizing indications in nuclear components during farication show that the Section XI technique tends to overestimate the size of the reflectors

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

    Directory of Open Access Journals (Sweden)

    Wust Peter

    2010-05-01

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

  16. Repeatability study of replicate crash tests: A signal analysis approach.

    Science.gov (United States)

    Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

    2017-10-03

    To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

  17. A double-blind, placebo-controlled, randomised, parallel-group, dose-escalating, repeat dose study in healthy volunteers to evaluate the safety, tolerability, pharmacodynamic effects and pharmacokinetics of the once daily rectal application of NRL001 suppositories for 14 days.

    Science.gov (United States)

    Bell, D; Duffin, A; Jacobs, A; Pediconi, C; Gruss, H J

    2014-03-01

    The 1R,2S stereoisomer of methoxamine hydrochloride, NRL001, is a highly selective α1-adrenoceptor agonist being developed for the local treatment of non-structural faecal incontinence caused by weak internal anal sphincter tone. This study investigated the steady state pharmacokinetics (PK) and safety of 2 g rectal suppositories containing NRL001 in different strengths (7.5, 10, 12.5 or 15 mg). Healthy volunteers aged 18-45 years received 14 daily doses of NRL001 2 g suppositories or matching placebo. In each dose group nine participants received NRL001 and three received placebo. Blood samples to determine NRL001 concentrations were taken on Days 1, 7 and 14. Cardiovascular parameters were collected via electrocardiograms, Holter monitoring (three lead Holter monitor) and vital signs. Forty-eight volunteers were enrolled; 43 completed the study and were included in the PK analysis population. AUC and Cmax broadly increased with increasing dose, Tmax generally occurred between 4.0 and 5.0 h. Although the data did not appear strongly dose proportional, dose proportionality analysis did not provide evidence against dose proportionality as the log(dose) coefficients were not significantly < 1. NRL001 did not accumulate over time for any dose. Increasing NRL001 concentrations were related to changes in vital sign variables, most notably decreased heart rate. The most commonly reported adverse events (AEs) in the active treatment groups were paraesthesia and piloerection. Treatment with NRL001 was generally well tolerated over 14 days once daily dosing and plasma NRL001 did not accumulate over time. Treatment was associated with changes in vital sign variables, most notably decreased heart rate. AEs commonly reported with NRL001 treatment were events indicative of a systemic α-adrenergic effect. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

  18. Clinical evaluation of the hypoxic cytotoxin tirapazamine (SR-4233): phase I experience with repeated dose administration during fractionated irradiation

    International Nuclear Information System (INIS)

    Hancock, Steven L.; Spencer, Sharon; Mariscal, Carol; Wooten, Ann; Wheeler, Richard; Brown, J. Martin; Fisher, Cheryl; Roemeling, Reinhard von

    1996-01-01

    Purpose: Regions of chronic or transient hypoxia are common in many human tumors and are thought to limit tumor cell killing and tumor control with conventional irradiation and some chemotherapeutic agents. Tirapazamine (3-amino-1,2,4-benzotriazine-1,4-di-N-oxide) forms a cytotoxic free radical during reductive metabolism in regions of hypoxia. In well oxygenated regions, the tirapazamine radical reacts with molecular oxygen to form the inactive parent drug. This results in markedly greater toxicity for hypoxic cells than for the well oxygenated cells that comprise most normal tissues. Tirapazamine increased the anti-tumor effects of single dose or fractionated irradiation or cis-platin chemotherapy in murine tumors,in vivo . This study evaluated the ability to repeat the administration of Tirapazamine during courses of fractionated irradiation in humans after an earlier phase I trial established a maximum tolerated dose of 390 mg per square meter of body surface area (mg/m 2 ) when given as a single dose with radiotherapy. Materials and Methods: Between December 1993 and August 1995 22 patients with locally advanced or metastatic tumors of varying histology, normal renal, hepatic, and hematologic functions, and Karnofsky performance status ≥ 60 received repeated doses of Tirapazamine during a planned, 6 weeks course of standardly fractionated radiotherapy. After anti-emetic treatment with ondansetron (32 mg) and dexamethasone (16 mg), Tirapazamine was administered during a 2 hour intravenous infusion that ended from 30 to 90 minutes before a radiation treatment. Patients were monitored for acute toxicity during the course of treatment and for a minimum of one month after radiotherapy. Results: The study was initiated with three, biweekly doses of Tirapazamine at 330 mg/m 2 . Four of 7 patients who initiated treatment at this dose refused the second (1 patient) or third dose of Tirapazamine (3 patients). Two of the three patients who received three doses

  19. Safety and Pharmacokinetic Profiles of Repeated-Dose Micafungin in Children and Adolescents Treated for Invasive Candidiasis

    Science.gov (United States)

    Benjamin, Daniel K.; Deville, Jaime G.; Azie, Nkechi; Kovanda, Laura; Roy, Mike; Wu, Chunzhang; Arrieta, Antonio

    2013-01-01

    Background Micafungin is an echinocandin with proven efficacy against a broad range of fungal infections, including those caused by Candida species. Objective To evaluate the safety and pharmacokinetics of once-daily 3 mg/kg and 4.5 mg/kg micafungin in children with proven, probable, or suspected invasive candidiasis. Methods Micafungin safety and pharmacokinetics were assessed in two Phase I, open-label, repeat-dose trials. In Study 2101, children aged 2–16 years were grouped by weight to receive 3 mg/kg (≥25 kg) or 4.5 mg/kg (<25 kg) intravenous micafungin for 10–14 days. In Study 2102, children aged 4 months to <2 years received 4.5 mg/kg micafungin. Study protocols were otherwise identical. Results Safety was analyzed in seventy-eight and nine children in Studies 2101 and 2102, respectively. Although adverse events were experienced by most children (2101: n = 62; 2102: n = 9), micafungin-related adverse events were less common (2101: n = 28; 2102: n = 1), and the number of patients discontinuing due to adverse events was low (2101: n = 4; 2102: n = 1). The most common micafungin-related adverse events were infusion-associated symptoms, pyrexia, and hypomagnesemia (Study 2101), and liver function abnormalities (Study 2102). The micafungin pharmacokinetic profile was similar to that seen in other studies conducted in children, but different than that observed in adults. Conclusions In this small cohort of children, once-daily doses of 3 mg/kg and 4.5 mg/kg micafungin were well tolerated. Pharmacokinetic data will be combined in a population pharmacokinetic analysis to support U.S. dosing recommendations in children. PMID:23958810

  20. Screening of repeated dose toxicity data present in SCC(NF)P/SCCS safety evaluations of cosmetic ingredients.

    Science.gov (United States)

    Vinken, Mathieu; Pauwels, Marleen; Ates, Gamze; Vivier, Manon; Vanhaecke, Tamara; Rogiers, Vera

    2012-03-01

    Alternative methods, replacing animal testing, are urgently needed in view of the European regulatory changes in the field of cosmetic products and their ingredients. In this context, a joint research initiative called SEURAT was recently raised by the European Commission and COLIPA, representing the European cosmetics industry, with the overall goal of developing an animal-free repeated dose toxicity testing strategy for human safety assessment purposes. Although cosmetic ingredients are usually harmless for the consumer, one of the initial tasks of this research consortium included the identification of organs that could potentially be affected by cosmetic ingredients upon systemic exposure. The strategy that was followed hereof is described in the present paper and relies on the systematic evaluation, by using a self-generated electronic databank, of published reports issued by the scientific committee of DG SANCO responsible for the safety of cosmetic ingredients. By screening of the repeated dose toxicity studies present in these reports, it was found that the liver is potentially the most frequently targeted organ by cosmetic ingredients when orally administered to experimental animals, followed by the kidney and the spleen. Combined listing of altered morphological, histopathological, and biochemical parameters subsequently indicated the possible occurrence of hepatotoxicity, including steatosis and cholestasis, triggered by a limited number of cosmetic compounds. These findings are not only of relevance for the in vitro modeling efforts and choice of compounds to be tested in the SEURAT project cluster, but also demonstrate the importance of using previously generated toxicological data through an electronic databank for addressing specific questions regarding the safety evaluation of cosmetic ingredients.

  1. Repeated dose intramuscular injection of the CIMAvax-EGF vaccine in Sprague Dawley rats induces local and systemic toxicity.

    Science.gov (United States)

    Mancebo, A; Casacó, A; González, B; Ledón, N; Sorlozabal, J; León, A; Gómez, D; González, Y; Bada, A M; González, C; Arteaga, M E; Ramírez, H; Fuentes, D

    2012-05-09

    CIMAvax-EGF consists of a human recombinant epidermal growth factor (EGF), coupled to P64k, a recombinant carrier protein from N. meningitis, and Montanide ISA 51 as adjuvant. The vaccine immunization induces a specific antibody production, inhibiting the EGF/EGF-R interaction through EGF deprivation. The objective of this study was to assess the CIMAvax-EGF toxicity in Sprague Dawley rats after intramuscular administration of repeated doses (6 months) and at the same time to determine if rat is a relevant species for studying CIMAvax-EGF vaccine. Rats were randomly distributed into four groups: control, Montanide ISA 51, treated with 1× and 15× of human total dose of the antigen. Animals were immunized weekly during 9 weeks, plus 9 immunizations every 14 days. Rats were inspected daily for clinical signs. Body weight, food consumption, and rectal temperature were measured during the administration of doses. Blood samples were collected for hematological, serum biochemical determinations and EGF titles at the beginning, three months and at the end of experimentation. Gross necropsy and histological examination of tissues were performed on animals at the end of the assay. Vaccine provoked the apparition of antibodies against EGF in the rats, demonstrating rat species relevance in these studies. Body weight gain, food and water consumption were not affected. CIMAvax-EGF and Montanide ISA 51 produced local damage at the administration site, showing multiple cysts and granulomas. Both vaccine-treated groups showed neutrophil elevation, besides an AST increase probably related to the damage at the administration site. Rectal temperature was found to be significantly higher in 15× treated group after immunizations, probably induced by the inflammatory process at the injection site. In summary, the clinical pathology findings together with the body temperature results, appear to be caused by the inflammatory reaction at the administration site of the vaccine, mainly

  2. Repeated dose 90-day oral toxicity test of G-7% NANA in rats: An application of new criterion for toxicity determination to test article-induced changes.

    Science.gov (United States)

    Heo, Hye Seon; An, MinJi; Lee, Ji Sun; Kim, Hee Kyong; Park, Yeong-Chul

    2018-06-01

    G-7% NANA is N-acetylneuraminic acid(NANA) containing 7% sialic acid isolated from glycomacropeptide (GMP), a compound of milk. Since NANA is likely to have immunotoxicity, the need to ensure safety for long-term administration has been raised. In this study, a 90-day repeated oral dose toxicity test was performed in rats using G-7% NANA in the dosages of 0, 1250, 2500 and 5000 mg/kg/day.A toxicity determination criterion based on the significant change caused by the administration of the substancewas developed for estimating NOEL, NOAEL and LOAELapplied to this study. When analyzing the immunological markers, no significant changes were observed, even if other significant changes were observed in the high dose group. In accordance with the toxicity determination criterion developed, the NOEL in male and female has been determined as 2500 mg/kg/day, and the NOAEL in females has been determined as 5000 mg/kg/day. The toxicity determination criterion, applied for the first time in the repeated dose toxicity tests, could provide a basis for distinguishing NOEL and NOAEL more clearly; nevertheless, the toxicity determination criterion needs to be supplemented by adding differentiating adverse effects and non-adverse effects based on more experiences of the repeated dose toxicity tests. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Effect of repeated small-dose γ-ray irradiation on atopic dermatitis in NC/Nga mice

    International Nuclear Information System (INIS)

    Fang, Su-Ping; Muto, Yasuko; Tago, Fumitoshi; Simura, Noriko; Kojima, Shuji

    2006-01-01

    We previously showed that several small-dose 0.5 Gy whole-body γ-ray irradiation inhibits tumor growth in mice via elevation of the interferon (IFN)-γ/interleukin 4 (IL-4) ratio concomitantly with a decrease in the percentage of B cells. Here, we examined whether repeated small-dose (0.5 Gy, 10 times) γ-ray irradiation influences atopic dermatitis in an NC/Nga mouse model. It was found that repeated γ-ray irradiation increased total IgE in comparison with the disease-control group. Levels of IL-4 and IL-5 were increased versus the disease-control group, while IFN-γ was slightly decreased, resulting in a further decrease of the IFN-γ/IL-4 ratio compared with the disease-control group. These results indicate that repeated small-dose γ-ray irradiation may exacerbate atopic dermatitis. This may be because the irradiation induces not helper T lymphocyte 1 (Th1), but Th2 polarization in this atopic mouse model, i.e., the effects of small-dose irradiation may be different in conditions involving immune hypersensitivity and impaired immunity. (author)

  4. Estimation of breast doses and breast cancer risk associated with repeated fluoroscopic chest examinations of women with tuberculosis

    International Nuclear Information System (INIS)

    Boice, J.D. Jr.; Rosenstein, M.; Trout, E.D.

    1978-01-01

    A methodology is presented to estimate cumulative breast dose and breast cancer risk for women exposed to repeated fluoroscopic chest examinations during air collapse therapy for pulmonary tuberculosis. Medical record abstraction, physician interview, patient contact, machine exposure measurements, and absorbed dose computations were combined to estimate average breast doses for 1047 Massachusetts women who were treated between 1930 and 1954. The methodology presented considers breast size and composition, patient orientation, x-ray field size and location, beam quality, type of examination, machine exposure rate, and exposure time during fluoroscopic examinations. The best estimate for the risk of radiation-induced cancer for the women living longer than 10 years after initial fluoroscopic exposure is 6.2 excess breast cancers per million woman-year-rad with 90% confidence limits of 2.8 and 10.7 cancers/10 6 WY-rad. When breast cancer risk is considered as a function of absorbed dose in the breast, instead of as a function of the number of fluoroscopic examinations, a linear dose--response relationship over the range of estimated doses is consistent with the data. However, because of the uncertainty due to small-sample variability and because of the wide range of assumptions regarding certain fluoroscopy conditions, other dose--response relationships are compatible with the data

  5. Late occurring lesions in the skin of rats after repeated doses of X-rays

    International Nuclear Information System (INIS)

    Hopewell, J.W.

    1985-01-01

    Late radiation damage, characterized by atrophy and necrosis in the skin and subcutaneous tissues, has been demonstrated in both the tail and feet of rats. The incidence of necrosis increased with total dose. These total doses, in the range 72-144 Gy, were given as 4-8 treatment of 18 Gy, each dose separated from the next by an interval of 28 days. This treatment protocol minimized acute epithelial skin reactions. The same regime applied to the skin on the back of rats resulted in a very severe acute reaction occurring after the second to fifth dose of 18 Gy. This was surprising since back skin, like tail skin, is less sensitive to large single doses of radiation than that of the foot. The late radiation reaction in the foot and tail of rats are compared and contrasted with other attempts to assess late effects in rodent skin and with late changes seen in pig skin. (author)

  6. Neurotoxicity of low-dose repeatedly intranasal instillation of nano- and submicron-sized ferric oxide particles in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing; Feng Weiyue, E-mail: fengwy@mail.ihep.ac.cn; Zhu Motao; Wang Yun; Wang Meng [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Gu Yiqun [Maternity Hospital of Haidian District (China); Ouyang Hong; Wang Huajian; Li Ming; Zhao Yuliang, E-mail: zhaoyuliang@mail.ihep.ac.cn; Chai Zhifang [Chinese Academy of Sciences, Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety and Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics (China); Wang Haifang [Peking University, College of Chemistry and Molecular Engineering (China)

    2009-01-15

    Olfactory tract has been demonstrated to be an important portal for inhaled solid nanoparticle transportation into the central nervous system (CNS). We have previously demonstrated that intranasally instilled Fe{sub 2}O{sub 3} nanoparticles could transport into the CNS via olfactory pathway. In this study, we investigated the neurotoxicity and size effect of repeatedly low-dose (130 {mu}g) intranasal exposure of nano- and submicron-sized Fe{sub 2}O{sub 3} particles (21 nm and 280 nm) to mice. The biomarkers of oxidative stress, activity of nitric oxide synthases and release of monoamine neurotransmitter in the brain were studied. Our results showed that significant oxidative stress was induced by the two sizes of Fe{sub 2}O{sub 3} particles. The activities of GSH-Px, Cu,Zn-SOD, and cNOS significantly elevated and the total GSH and GSH/GSSG ratio significantly decreased in the olfactory bulb and hippocampus after the nano- and submicron-sized Fe{sub 2}O{sub 3} particle treatment (p < 0.05). The nano-sized Fe{sub 2}O{sub 3} generally induced greater alteration and more significant dose-effect response than the submicron-sized particle did. Some slight perturbation of monoamine neurotransmitters were found in the hippocampus after exposure to the two sizes of Fe{sub 2}O{sub 3} particle. The TEM image showed that some ultrastructural alterations in nerve cells, including neurodendron degeneration, membranous structure disruption and lysosome increase in the olfactory bulb, slight dilation in the rough endoplasmic reticulum and lysosome increase in the hippocampus were induced by the nano-sized Fe{sub 2}O{sub 3} treatment. In contrast, in the submicron-sized Fe{sub 2}O{sub 3} treated mice, slightly swollen mitochondria and some vacuoles were observed in the olfactory bulb and hippocampus, respectively. These results indicate that intranasal exposure of Fe{sub 2}O{sub 3} nanoparticles could induce more severe oxidative stress and nerve cell damage in the brain than the

  7. Repeated dose oral toxicity of inorganic mercury in wistar rats: biochemical and morphological alterations

    Directory of Open Access Journals (Sweden)

    M. D. Jegoda

    2013-06-01

    Full Text Available Aim: The study was conducted to find out the possible toxic effect of mercuric chloride (HgCl2 at the histological, biochemical, and haematological levels in the wistar rats for 28 days. Materials and Methods: The biochemical and hematological alteration were estimated in four groups of rat (each group contain ten animals, which were treated with 0 (control, 2, 4, and 8 mg/kg body weight of HgCl2 through oral gavage. At the end of study all rats were sacrificed and subjected for histopathology. Result: A significantly (P < 0.05 higher level of serum alanine amino transferase (ALT, gamma Glutamyle Transferase, and creatinine were recorded in treatment groups, while the level of alkaline phosphtase (ALP was significantly decreased as compared to the control group. The toxic effect on hematoclogical parameter was characterized by significant decrease in hemoglobin, packed cell volume, total erythrocytes count, and total leukocyte count. Gross morphological changes include congestion, severe haemorrhage, necrosis, degenerative changes in kidneys, depletion of lymphocyte in spleen, decrease in concentration of mature spermatocyte, and edema in testis. It was notable that kidney was the most affected organ. Conclusion: Mercuric chloride (HgCl caused dose-dependent toxic effects on blood parameters and kidney. [Vet World 2013; 6(8.000: 563-567

  8. Effects of acute and repeated oral doses of D-tagatose on plasma uric acid in normal and diabetic humans.

    Science.gov (United States)

    Saunders, J P; Donner, T W; Sadler, J H; Levin, G V; Makris, N G

    1999-04-01

    D-tagatose, a stereoisomer of D-fructose, is a naturally occurring ketohexose proposed for use as a low-calorie bulk sweetener. Ingested D-tagatose appears to be poorly absorbed. The absorbed portion is metabolized in the liver by a pathway similar to that of D-fructose. The main purpose of this study was to determine if acute or repeated oral doses of D-tagatose would cause elevations in plasma uric acid (as is seen with fructose) in normal humans and Type 2 diabetics. In addition, effects of subchronic D-tagatose ingestion on fasting plasma phosphorus, magnesium, lipids, and glucose homeostasis were studied. Eight normal subjects and eight subjects with Type 2 diabetes participated in this two-phase study. Each group was comprised of four males and four females. In the first phase, all subjects were given separate 75 g 3-h oral glucose and D-tagatose tolerance tests. Uric acid, phosphorus, and magnesium were determined in blood samples collected from each subject at 0, 30, 60, 120, and 180 min after dose. In the 8-week phase of the study, the normals were randomly placed into two groups which received 75 g of either D-tagatose or sucrose (25 g with each meal) daily for 8 weeks. The diabetics were randomized into two groups which received either 75 g D-tagatose or no supplements of sugar daily for 8 weeks. Uric acid, phosphorus, magnesium, lipids, glycosylated hemoglobin, glucose, and insulin were determined in fasting blood plasma of all subjects at baseline (time zero) and biweekly over the 8 weeks. The 8-week test did not demonstrate an increase in fasting plasma uric acid in response to the daily intake of D-tagatose. However, a transient increase of plasma uric acid levels was observed after single doses of 75 g of D-tagatose in the tolerance test. Plasma uric acid levels were found to rise and peak at 60 min after such dosing. No clinical relevance was attributed to this treatment-related effect because excursions of plasma uric acid levels above the normal

  9. Pharmacokinetics of repeated oral doses of amlodipine and amlodipine plus telmisartan in healthy volunteers.

    Science.gov (United States)

    Stangier, J; Su, C A

    2000-12-01

    This open-label, crossover study was performed to establish if there is evidence for interaction between telmisartan, an angiotensin II antagonist, and amlodipine, a class II (dihydropyridine) calcium channel antagonist, on the basis of pharmacokinetics and safety. In a two-way crossover trial, 12 healthy Caucasian males were randomized to receive once daily for 9 days oral amlodipine 10 mg with or without oral telmisartan 120 mg. After a washout period of > or = 13 days, the subjects were switched to the other medication regimen. The geometric means of the primary pharmacokinetic parameters at steady state (day 9) for amlodipine when given alone were the following: maximum plasma concentration (Cmax) 17.7 ng/mL, area under the plasma concentration-time curve (AUC) 331 ng.h/mL, and renal clearance 39.5 mL/min, with 8% of the total amlodipine dose being excreted. When concomitant telmisartan was given, the respective values were 18.7 ng/mL, 352 ng.h/mL, and 43.0 mL/min, with 9.4% of the total amlodipine dose being excreted renally. The limits of the 90% confidence intervals (CIs) for the ratios of these steady-state parameters were 0.97 to 1.14 for Cmax and 0.98 to 1.16 for AUC; both were within the predefined reference range (0.8 to 1.25) for bioequivalence. The high intersubject variability in urinary amlodipine excretion resulted in bioequivalence not being demonstrated for renal clearance. Adverse effects were few, mild to moderate in intensity, and transient whether amlodipine was given alone or with telmisartan. Vital signs, except for blood pressure, and clinical laboratory values were unaffected by either medication. The findings of this study show that concomitant telmisartan and amlodipine may be administered as there is no clinically significant variation in primary pharmacokinetic parameters of amlodipine in the presence of telmisartan, and the safety of the combination is comparable to that of amlodipine alone.

  10. Comparison of distribution and toxicity following repeated oral dosing of different vanadium oxide nanoparticles in mice

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun-Jung, E-mail: pejtoxic@hanmail.net [Myunggok Eye Research Institute, Konyang University, Daejeon 302-718 (Korea, Republic of); Lee, Gwang-Hee [School of Civil, Environmental, and Architectural Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Yoon, Cheolho [Seoul Center, Korea Basic Science Institute, Seoul 126-16 (Korea, Republic of); Kim, Dong-Wan, E-mail: dwkim1@korea.ac.kr [School of Civil, Environmental, and Architectural Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2016-10-15

    Vanadium is an important ultra-trace element derived from fuel product combustion. With the development of nanotechnology, vanadium oxide nanoparticles (VO NPs) have been considered for application in various fields, thus the possibility of release into the environment and human exposure is also increasing. Considering that verification of bioaccumulation and relevant biological responses are essential for safe application of products, in this study, we aimed to identify the physicochemical properties that determine their health effects by comparing the biological effects and tissue distribution of different types of VO NPs in mice. For this, we prepared five types of VO NPs, commercial (C)-VO{sub 2} and -V{sub 2}O{sub 5} NPs and synthetic (S)-VO{sub 2}, -V{sub 2}O{sub 3,} and -V{sub 2}O{sub 5} NPs. While the hydrodynamic diameter of the two types of C-VO NPs was irregular and impossible to measure, those of the three types of S-VO NPs was in the range of 125–170 nm. The S- and C-V{sub 2}O{sub 5} NPs showed higher dissolution rates compared to other VO NPs. We orally dosed the five types of VO NPs (70 and 210 μg/mouse, approximately 2 and 6 mg/kg) to mice for 28 days and compared their biodistribution and toxic effects. We found that S-V{sub 2}O{sub 5} and S-V{sub 2}O{sub 3} NPs more accumulated in tissues compared to other three types of VO NPs, and the accumulated level was in order of heart>liver>kidney>spleen. Additionally, tissue levels of redox reaction-related elements and electrolytes (Na{sup +}, K{sup +}, and Ca{sup 2+}) were most clearly altered in the heart of treated mice. Notably, all S- and C-VO NPs decreased the number of WBCs at the higher dose, while total protein and albumin levels were reduced at the higher dose of S-V{sub 2}O{sub 5} and S-V{sub 2}O{sub 3} NPs. Taken together, we conclude that the biodistribution and toxic effects of VO NPs depend on their dissolution rates and size (surface area). Additionally, we suggest that further studies

  11. Low-dose metformin improves pregnancy rate in in vitro fertilization repeaters without polycystic ovary syndrome: prediction of effectiveness by multiple parameters related to insulin resistance.

    Science.gov (United States)

    Jinno, Masao; Kondou, Kenichi; Teruya, Koji

    2010-01-01

    Insulin resistance is associated with aging and stress, both common among patients repeatedly failing to conceive with in vitro fertilization (IVF repeaters). In the present study we examined whether low-dose metformin could improve the outcome in IVF repeaters without polycystic ovary syndrome (PCOS). Study I was a preliminary clinical trial aiming at defining indications for therapy; study II was a prospective randomized study. The studies involved a university hospital and a private infertility clinic. We studied 232 women without PCOS who had failed at least twice to conceive by previous IVF. Metformin (500 mg/ day) was administered for 8 to 12 weeks before and during ovarian stimulation (metformin IVF). In study I, IVF outcomes with metformin (n = 33) were compared to outcomes without metformin of previous IVF in the same subjects. A discriminant score (DS) was determined from nine parameters assessed before metformin administration to predict achievement of ongoing pregnancy by metformin IVF. In study II (n = 199), ongoing pregnancy rates were compared prospectively between groups with/without metformin and with DS above/below 0.6647. Study I. Ongoing pregnancy rate improved significantly with metformin compared with previous IVF, and pregnancy correlated significantly with a DS at an optimal threshold of 0.6647 (sensitivity, 0.90; specificity, 0.91). Study II. Ongoing pregnancy and implantation rates were significantly higher in women with a DS above 0.6647 who received metformin (56% and 33%) compared with those having a DS below 0.6647 with metformin (14% and 11%) and those having a DS above/below 0.6647 without metformin (20% and 7.1%/15% and 11%, respectively). Low-dose metformin improved pregnancy rate in IVF repeaters without PCOS, probably by decreasing insulin resistance. Indication can be determined from insulin-resistance-related multiple parameters assessed before metformin administration.

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

    Science.gov (United States)

    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

  13. Interactions between cannabidiol and Δ9-THC following acute and repeated dosing: Rebound hyperactivity, sensorimotor gating and epigenetic and neuroadaptive changes in the mesolimbic pathway.

    Science.gov (United States)

    Todd, Stephanie M; Zhou, Cilla; Clarke, David J; Chohan, Tariq W; Bahceci, Dilara; Arnold, Jonathon C

    2017-02-01

    The evidence base for the use of medical cannabis preparations containing specific ratios of cannabidiol (CBD) and Δ 9 -tetrahydrocannabinol (THC) is limited. While there is abundant data on acute interactions between CBD and THC, few studies have assessed the impact of their repeated co-administration. We previously reported that CBD inhibited or potentiated the acute effects of THC dependent on the measure being examined at a 1:1 CBD:THC dose ratio. Further, CBD decreased THC effects on brain regions involved in memory, anxiety and body temperature regulation. Here we extend on these finding by examining over 15 days of treatment whether CBD modulated the repeated effects of THC on behaviour and neuroadaption markers in the mesolimbic dopamine pathway. After acute locomotor suppression, repeated THC caused rebound locomotor hyperactivity that was modestly inhibited by CBD. CBD also slightly reduced the acute effects of THC on sensorimotor gating. These subtle effects were found at a 1:1 CBD:THC dose ratio but were not accentuated by a 5:1 dose ratio. CBD did not alter the trajectory of enduring THC-induced anxiety nor tolerance to the pharmacological effects of THC. There was no evidence of CBD potentiating the behavioural effects of THC. However we demonstrated for the first time that repeated co-administration of CBD and THC increased histone 3 acetylation (H3K9/14ac) in the VTA and ΔFosB expression in the nucleus accumbens. These changes suggest that while CBD may have protective effects acutely, its long-term molecular actions on the brain are more complex and may be supradditive. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

  14. PET functional volume delineation: a robustness and repeatability study

    International Nuclear Information System (INIS)

    Hatt, Mathieu; Cheze-le Rest, Catherine; Albarghach, Nidal; Pradier, Olivier; Visvikis, Dimitris

    2011-01-01

    Current state-of-the-art algorithms for functional uptake volume segmentation in PET imaging consist of threshold-based approaches, whose parameters often require specific optimization for a given scanner and associated reconstruction algorithms. Different advanced image segmentation approaches previously proposed and extensively validated, such as among others fuzzy C-means (FCM) clustering, or fuzzy locally adaptive bayesian (FLAB) algorithm have the potential to improve the robustness of functional uptake volume measurements. The objective of this study was to investigate robustness and repeatability with respect to various scanner models, reconstruction algorithms and acquisition conditions. Robustness was evaluated using a series of IEC phantom acquisitions carried out on different PET/CT scanners (Philips Gemini and Gemini Time-of-Flight, Siemens Biograph and GE Discovery LS) with their associated reconstruction algorithms (RAMLA, TF MLEM, OSEM). A range of acquisition parameters (contrast, duration) and reconstruction parameters (voxel size) were considered for each scanner model, and the repeatability of each method was evaluated on simulated and clinical tumours and compared to manual delineation. For all the scanner models, acquisition parameters and reconstruction algorithms considered, the FLAB algorithm demonstrated higher robustness in delineation of the spheres with low mean errors (10%) and variability (5%), with respect to threshold-based methodologies and FCM. The repeatability provided by all segmentation algorithms considered was very high with a negligible variability of <5% in comparison to that associated with manual delineation (5-35%). The use of advanced image segmentation algorithms may not only allow high accuracy as previously demonstrated, but also provide a robust and repeatable tool to aid physicians as an initial guess in determining functional volumes in PET. (orig.)

  15. Doses in mammography. Preliminary study

    International Nuclear Information System (INIS)

    Marquez P, F.; Acosta R, N.; Universidad Nacional Mayor de San Marcos, Lima; Benavente, T.; Universidad Nacional Mayor de San Marcos, Lima; Poma, M.

    2002-01-01

    Mammography is the most important method to detect lesions in the breast with this technique one can detect small tumours before clear clinical symptoms appear. Mammographic image of require high quality standards due that the extremely low contrast between the normal and pathological areas in the breast, eg.g., they have similar attenuation and absorption coefficient. The x-ray mammographic systems, used in this study are Senographe 500t and Senographe DMR, a detector with a RadCal ionization chambers calibrated to the qualities of mammographic x-ray beams, and a breast simulator that is a phantoms of polymethylmethacrylate (PMMA) of several thicknesses with the equivalence of 50% of the glandular tissue. The results obtained indicate that the values of doses at the entrance surface of a breast (DES) are greater the reference value 20 mGy to 5,0 cm of PMMA and the values of the mean glandular dose (MGD) exceed the reference value of 2,1 mGy for 5,1 cm of compressed thick breast. We consider that the values high of the EDS and MGD are due that the x-ray systems no meeting in good condition or for used of x-ray spectra no suitable, so is recommendable be carried out test of quality control to the x-ray systems and also realize studies, or characterize the of x-ray mammographic spectra

  16. Receptionist input to quality and safety in repeat prescribing in UK general practice: ethnographic case study.

    Science.gov (United States)

    Swinglehurst, Deborah; Greenhalgh, Trisha; Russell, Jill; Myall, Michelle

    2011-11-03

    To describe, explore, and compare organisational routines for repeat prescribing in general practice to identify contributors and barriers to safety and quality. Ethnographic case study. Four urban UK general practices with diverse organisational characteristics using electronic patient records that supported semi-automation of repeat prescribing. 395 hours of ethnographic observation of staff (25 doctors, 16 nurses, 4 healthcare assistants, 6 managers, and 56 reception or administrative staff), and 28 documents and other artefacts relating to repeat prescribing locally and nationally. Potential threats to patient safety and characteristics of good practice. Observation of how doctors, receptionists, and other administrative staff contributed to, and collaborated on, the repeat prescribing routine. Analysis included mapping prescribing routines, building a rich description of organisational practices, and drawing these together through narrative synthesis. This was informed by a sociological model of how organisational routines shape and are shaped by information and communications technologies. Results Repeat prescribing was a complex, technology-supported social practice requiring collaboration between clinical and administrative staff, with important implications for patient safety. More than half of requests for repeat prescriptions were classed as "exceptions" by receptionists (most commonly because the drug, dose, or timing differed from what was on the electronic repeat list). They managed these exceptions by making situated judgments that enabled them (sometimes but not always) to bridge the gap between the idealised assumptions about tasks, roles, and interactions that were built into the electronic patient record and formal protocols, and the actual repeat prescribing routine as it played out in practice. This work was creative and demanded both explicit and tacit knowledge. Clinicians were often unaware of this input and it did not feature in policy

  17. The ToxBank Data Warehouse: Supporting the Replacement of In Vivo Repeated Dose Systemic Toxicity Testing.

    Science.gov (United States)

    Kohonen, Pekka; Benfenati, Emilio; Bower, David; Ceder, Rebecca; Crump, Michael; Cross, Kevin; Grafström, Roland C; Healy, Lyn; Helma, Christoph; Jeliazkova, Nina; Jeliazkov, Vedrin; Maggioni, Silvia; Miller, Scott; Myatt, Glenn; Rautenberg, Michael; Stacey, Glyn; Willighagen, Egon; Wiseman, Jeff; Hardy, Barry

    2013-01-01

    The aim of the SEURAT-1 (Safety Evaluation Ultimately Replacing Animal Testing-1) research cluster, comprised of seven EU FP7 Health projects co-financed by Cosmetics Europe, is to generate a proof-of-concept to show how the latest technologies, systems toxicology and toxicogenomics can be combined to deliver a test replacement for repeated dose systemic toxicity testing on animals. The SEURAT-1 strategy is to adopt a mode-of-action framework to describe repeated dose toxicity, combining in vitro and in silico methods to derive predictions of in vivo toxicity responses. ToxBank is the cross-cluster infrastructure project whose activities include the development of a data warehouse to provide a web-accessible shared repository of research data and protocols, a physical compounds repository, reference or "gold compounds" for use across the cluster (available via wiki.toxbank.net), and a reference resource for biomaterials. Core technologies used in the data warehouse include the ISA-Tab universal data exchange format, REpresentational State Transfer (REST) web services, the W3C Resource Description Framework (RDF) and the OpenTox standards. We describe the design of the data warehouse based on cluster requirements, the implementation based on open standards, and finally the underlying concepts and initial results of a data analysis utilizing public data related to the gold compounds. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Dose- and time-dependent changes in tissue levels of tetrabromobisphenol A (TBBPA and its sulfate and glucuronide conjugates following repeated administration to female Wistar Han Rats

    Directory of Open Access Journals (Sweden)

    S.J. Borghoff

    Full Text Available Tetrabromobisphenol A (TBBPA, a nongenotoxic flame retardant, causes uterine tumors in female rats. A proposed mode of action (MoA for these tumors involves an increase in the bioavailability of estradiol as a result of TBBPA inhibiting estrogen sulfotransferases (ES, the enzymes responsible for inactivating and enhancing the elimination of estradiol. The objective of this study was to evaluate the effect of dose and repeated administration of TBBPA on the level of TBBPA, TBBPA-glucuronide (GA and TBBPA-sulfate (S conjugates in plasma, liver and uterus of female Wistar Han rats administered TBBPA (50, 100, 250, 500 or 1000 mg/kg for 28 consecutive days. In accordance with this objective, TBBPA sulfation was used as a surrogate for evaluating the potential for estradiol sulfation to be limited at high dose levels of TBBPA. Blood samples were collected at 4 and 8 h post-dosing on study day 7, 14, and 28, while liver and uterus were collected at the same time points following 28 days of dosing. Tissue samples were analyzed for TBBPA, TBBPA-GA and TBBPA-S by LC–MS/MS. A dose-related increase in the concentration of all three analytes occurred in plasma (day 7, 14, and 28 as well as liver and uterus tissue (day 28 at both 4 and 8 h post dose. The plasma concentration of TBBPA-GA and TBBPA-S was higher in animals dosed for 28 days compared to those dosed for 7 or 14 days showing an increase in systemic circulation of these conjugates with repeated administration. The balance of these conjugates was also different in tissues with TBBPA-S > TBBPA-GA at high doses in the liver and TBBPA-GA > TBBPA-S in both plasma and uterus. In all three tissues the ratio of TBBPA-S/TBBPA-GA showed a decreasing trend with dose, suggesting that at high TBBPA dose levels sulfation of TBBPA becomes limited. This effect was most apparent in the liver and plasma at 28 days of administration. Together these data show that administration of high doses of TBBPA

  19. A long-acting integrase inhibitor protects female macaques from repeated high-dose intravaginal SHIV challenge.

    Science.gov (United States)

    Andrews, Chasity D; Yueh, Yun Lan; Spreen, William R; St Bernard, Leslie; Boente-Carrera, Mar; Rodriguez, Kristina; Gettie, Agegnehu; Russell-Lodrigue, Kasi; Blanchard, James; Ford, Susan; Mohri, Hiroshi; Cheng-Mayer, Cecilia; Hong, Zhi; Ho, David D; Markowitz, Martin

    2015-01-14

    Long-acting GSK1265744 (GSK744 LA) is a strand transfer inhibitor of the HIV/SIV (simian immunodeficiency virus) integrase and was shown to be an effective preexposure prophylaxis (PrEP) agent in a low-dose intrarectal SHIV (simian-human immunodeficiency virus) rhesus macaque challenge model. We examined the pharmacokinetics and efficacy of GSK744 LA as PrEP against repeat high-dose intravaginal SHIV challenge in female rhesus macaques treated with Depo-Provera (depot medroxyprogesterone acetate), which promotes viral transmission vaginally. When Depo-Provera-treated female rhesus macaques were dosed with GSK744 LA (50 mg/kg) monthly, systemic and tissue drug concentrations were lower than previously observed in male rhesus macaques. GSK744 concentrations were fivefold lower on average in cervical tissues than in rectal tissues. Eight female rhesus macaques were treated with GSK744 LA at week 0, and four female rhesus macaques served as controls. All animals received a high-dose challenge of SHIV162P3 at week 1. No infection was detected in GSK744 LA-treated rhesus macaques, whereas viremia was detected 1 to 2 weeks after SHIV challenge in all control animals. The GSK744 LA-treated rhesus macaques were given a second administration of drug at week 4 and further challenged at weeks 5 and 7. GSK744 LA treatment protected six of eight female rhesus macaques against three high-dose SHIV challenges, whereas all control animals became infected after the first challenge (P = 0.0003, log-rank test). These results support further clinical development of GSK744 LA for PrEP. Copyright © 2015, American Association for the Advancement of Science.

  20. Repeated Intramuscular-dose Toxicity Test of Water-soluble Carthami Flos (WCF Pharmacopuncture in Sprague-Dawley Rats

    Directory of Open Access Journals (Sweden)

    Yoo-min Choi

    2015-03-01

    Full Text Available Objectives: Water-soluble carthami flos (WCF is a new mixture of Carthami flos (CF pharmacopuncture. We conducted a 4-week toxicity test of repeated intramuscular injections of WCF in Sprague-Dawley rats. Methods: Forty male and 40 female rats were divided into 4 groups of 10 male and 10 female SD rats: The control group received 0.5 mL/animal/day of normal saline whereas the three experimental groups received WCF at doses of 0.125, 0.25, and 0.5 mL/animal/day, respectively. For 4 weeks, the solutions were injected into the femoral muscle of the rats alternating from side to side. Clinical signs, body weights, and food consumption were observed; opthalmological examinations and urinalyses were performed. On day 29, blood samples were taken for hematological and clinical chemistry analyses. Then, necropsy was conducted in all animals to observe weights and external and histopathological changes in the bodily organs. All data were tested using a statistical analysis system (SAS. Results: No deaths were observed. Temporary irregular respiration was observed in male rats of the experimental group for the first 10 days. Body weights, food consumptions, opthalmological examinations, urinalyses, clinical chemistry analyses, organ weights and necropsy produced no findings with toxicological meaning. In the hematological analysis, delay of prothrombin time (PT was observed in male rats of the 0.25- and the 0.5-mL/animal/day groups. In the histopathological test, a dose-dependent inflammatory cell infiltration into the fascia and panniculitis in perimuscular tissues was observed in all animals of the experimental groups. However, those symptoms were limited to local injection points. No toxicological meanings, except localized changes, were noted. Conclusion: WCF solution has no significant toxicological meaning, but does produce localized symptoms. No observed adverse effect level (NOAEL of WCF in male and female rats is expected for doses over 0.5 mL/animal/day.

  1. A study on the repeatability of ultrasonic testing data

    International Nuclear Information System (INIS)

    Yoshimura, Seiichi; Fukumoto, Hiroshi

    1980-01-01

    Reliability improvement of ultrasonic testing data is strongly desired in ultrasonic testing working of nuclear power plants. This paper deals with the problems of the testing by the manual and the remote control apparatus, and with the factors which influence the repeatability of ultrasonic testing data. Following results are found in it. (1) In the testing by the manual, working time and posture influence the repeatability of testing data. (2) Glycerin in suitable for the couplant in the respect of the repeatability of testing data. In the case of using machine oil, the pressure to the probe necessitates to be over 0.2 kg/cm 2 . (3) In the testing by the remote control apparatus, working time, working environment and defect position does not influence the repeatability of testing data. (author)

  2. A Phase I randomized clinical trial testing the safety, tolerability and preliminary pharmacokinetics of the mGluR5 negative allosteric modulator GET 73 following single and repeated doses in healthy volunteers.

    Science.gov (United States)

    Haass-Koffler, Carolina L; Goodyear, Kimberly; Long, Victoria M; Tran, Harrison H; Loche, Antonella; Cacciaglia, Roberto; Swift, Robert M; Leggio, Lorenzo

    2017-11-15

    Preclinical work suggests that the metabotropic glutamate receptor subtype 5 (mGlu5) may represent a novel target to treat neuropsychiatric disorders, including alcohol use disorder and obesity. The goal of this first-in-man study was to evaluate the safety, tolerability and pharmacokinetics (PK) of GET 73 (PubChem SID: 329974174), a novel mGluR5 negative allosteric modulator. This was a double-blind, placebo-controlled, ascending dose, Phase I study conducted in healthy male volunteers in two experiments. GET 73 was administered as single ascending doses (N=48; Experiment 1; 10, 30, 100, 300, 450, 600-mg) or multiple ascending doses (N=32; Experiment 2; 100, 300, 450, 450-mg twice a day). Primary endpoints were the incidence of adverse events (AEs) among drug conditions and drug tolerability. The secondary endpoints were the PK parameters of GET 73 and its metabolite MET 2. Single GET 73 doses of up to 600-mg and repeated ascending doses of up to 450-mg twice/day were safe and well-tolerated. There were no serious or severe AEs. All AEs were mild or moderate in severity. Total GET 73 exposure increased with each increased GET 73 dose. A dose-related increase in mean maximum plasma drug concentration was observed after repeated dosing. Maximum plasma drug concentrations occurred between 0.5 and 2.05h after administration in all groups for both single and repeated doses. This first-in-human study indicates that GET 73, as single or multiple ascending doses, is safe and well-tolerated when administered to healthy male volunteers. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Safety and PK/PD correlation of TV-1106, a recombinant fused human albumin-growth hormone, following repeat dose administration to monkeys.

    Science.gov (United States)

    Ashkenazi, Nurit; Rosenstock, Moti; Hallak, Hussein; Bassan, Merav; Rasamoelisolo, Michele; Leuschner, Jost; Shinar, Doron

    TV-1106 is a recombinant human albumin genetically fused to growth hormone which is intended to reduce the frequency of injections for GH therapy users. We report the safety, tolerability, pharmacokinetics and pharmacodynamics of repeated subcutaneous injections of TV-1106 in Cynomolgus monkeys. Cynomolgus monkeys received four weekly subcutaneous injections of 0, 5, 10 or 20mg/kg TV-1106 and were monitored for safety signals throughout the study. Serum levels of TV-1106 and insulin-like growth factor 1 (IGF-1) were assayed. Treated animals showed no adverse effects or histopathological changes. TV-1106 serum concentrations showed sustained exposure to the drug. Exposure increased in a dose-dependent manner with peak concentrations at approximately 24h post-dosing and elimination half-lives in the range of 12 to 24h. IGF-1 serum concentrations were elevated throughout the entire study duration, indicative of the pharmacological response. There was a clear correlation between change in IGF-1 levels and dose or exposure to TV-1106. The safety, pharmacokinetic and pharmacodynamic findings support the further development of TV-1106 as a once-weekly administered treatment for patients with GHD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Comparison in the calculation of committed effective dose using the ICRP 30 and ICRP 60 models for a repeated incorporation by inhalation of I-125

    International Nuclear Information System (INIS)

    Carreno P, A.L.; Cortes C, A.; Alonso V, G.; Serrano P, F.

    2005-01-01

    Presently work, a comparison in the calculation of committed effective dose using the models of the ICRP 30 and those of the ICRP 60 for the analysis of internal dose due to repeated incorporation of I-125 is shown. The estimations of incorporated activity are obtained starting from the proportionate data for an exercise of inter comparison, with which it should be determined the internal dose later on. For to estimate the initial activity incorporated by repeated dose was assumed that this it was given through of multiple individual incorporations which happened in the middle points of the monitoring periods. The results using the models of the ICRP 30 and of the ICRP 60 are compared and the causes of the differences are analyzed. (Author)

  5. Exposing Students to Repeat Photography: Increasing Cultural Understanding on a Short-Term Study Abroad

    Science.gov (United States)

    Lemmons, Kelly K.; Brannstrom, Christian; Hurd, Danielle

    2014-01-01

    Traditionally, repeat photography has been used to analyze land cover change. This paper describes how repeat photography may be used as a tool to enhance the short-term study abroad experience by facilitating cultural interaction and understanding. We present evidence from two cases and suggest a five-step repeat photography method for educators…

  6. [Study on causes and treatment of repeated vulvovaginitis in girlhood].

    Science.gov (United States)

    Zhang, Di-kai; Li, Xiu-yun; Yang, Dong-zi; Kuang, Jian-quan

    2006-07-01

    To explore the causes and treatment of repeated vulvovaginitis in girlhood in order to improve its prevention and treatment. Fifty-one girls with repeated vulvovaginitis (age vulvovaginitis and 14 ones (27%) suffering from posterior recto-vaginal fistula with in 51 patients. Five girls (10%) were smitten with vulval ulcer and 3 ones (6%) had been were found with vaginal foreign bodies. One girl (2%) was smitten with adhesion of labia minora. The vaginal discharges taken from 21 girls were cultured. Seventeen cases found bacteria. The positive rate of bacteria culture in the 21 cases reached 81%, in which, E.coli accounted for 5 cases (24%), staphylococcus and streptococcus accounted for 3 cases (14%) respectively. Patients suffering from non-specific vulvovaginitis and vulval ulcer accepted external lotion, antibiotic ointment or combining with antibiotics. Patients suffering from posterior recto-vaginal fistula accepted fistulectomy. Three girls who found vaginal foreign bodies took out of foreign bodies by hysteroscope. Fifty-one girls all were cured after appropriate therapy. Vulvovaginitis is the most common gynecologic diagnosis in girlhood. The principal cause of repeated invasion is non-specific vulvovaginitis and the secondly one is posterior recto-vaginal fistula. It need overhaul during the diagnosis. It is very availability to use hysteroscopy and do bacteria culture + antibiotic sensitivity test for repeated pediatric vulvovaginitis.

  7. Study of simple sequence repeat (SSR) polymorphism for biotic ...

    African Journals Online (AJOL)

    home

    2013-10-02

    Oct 2, 2013 ... G. Siva Kumar1, K. Aruna Kumari1*, Ch. V. Durga Rani1, R. M. Sundaram2, S. Vanisree3, Md. ..... review by Jena and Mackill (2008) provided the list of .... repeat protein and is a member of a resistance gene cluster on rice.

  8. Education for patients with chronic kidney disease in Taiwan: a prospective repeated measures study.

    Science.gov (United States)

    Yen, Miaofen; Huang, Jeng-Jong; Teng, Hsiu-Lan

    2008-11-01

    To investigate the physical, knowledge and quality of life outcomes of an educational intervention for patients with early stage chronic kidney disease. A comprehensive predialysis education care team can be effective in slowing the progression of chronic kidney disease. A single group repeated measures design was used to evaluate the effects of the intervention. Participants were recruited through health department community health screen data banks. A predialysis, team-delivered educational intervention covering renal function health care, dietary management of renal function and the effects of Chinese herb medication on renal function was designed and implemented. Data were collected at baseline, six and 12 months. Study outcomes included physical indicators, knowledge (renal function protection, use of Chinese herbs and renal function and diet) and quality of life. Data were analysed using repeated measure anova to test for change over time in outcome variables. Sixty-six persons participated in this study. The predialysis educational intervention showed significant differences at the three time points in overall knowledge scores, waist-hip ratio, body mass index and global health status. Knowledge measures increased at month 6 and decreased at month 12. The primary indicator of renal function, glomerular filtration rate, remained stable throughout the 12 months of follow-up, despite the relatively older mean age of study participants. A predialysis education care team can provide effective disease-specific knowledge and may help retard deterioration of renal function in persons with early-stage chronic kidney disease. The intervention dose may need to be repeated every six months to maintain knowledge effects. A predialysis educational program with disease-specific knowledge and information is feasible and may provide positive outcomes for patients. Topics on the uses of Chinese herbs should be included for people who are likely to use alternative therapies.

  9. Dataset for Phase I randomized clinical trial for safety and tolerability of GET 73 in single and repeated ascending doses including preliminary pharmacokinetic parameters

    Directory of Open Access Journals (Sweden)

    Carolina L. Haass-Koffler

    2017-12-01

    Full Text Available The data in this article outline the methods used for the administration of GET 73 in the first time-in-human manuscript entitled “Phase I randomized clinical trial for the safety, tolerability and preliminary pharmacokinetics of the mGluR5 negative allosteric modulator GET 73 following single and repeated doses in healthy male volunteers” (Haass-Koffler et al., 2017 [1]. Data sets are provided in two different manners. The first series of tables provided includes procedural information about the experiments conducted. The next series of tables provided includes Pharmacokinetic (PK parameters for GET 73 and its main metabolite MET 2. This set of data is comprised by two experiments: Experiment 1 references a single ascending dose administration of GET 73 and Experiment 2 references a repeated ascending dose administration of GET 73. Keywords: Glutamate receptor subtype 5 (mGlu5, Allosteric modulator, GET 73, Safety, Tolerability

  10. Dataset for Phase I randomized clinical trial for safety and tolerability of GET 73 in single and repeated ascending doses including preliminary pharmacokinetic parameters.

    Science.gov (United States)

    Haass-Koffler, Carolina L; Goodyear, Kimberly; Long, Victoria M; Tran, Harrison H; Loche, Antonella; Cacciaglia, Roberto; Swift, Robert M; Leggio, Lorenzo

    2017-12-01

    The data in this article outline the methods used for the administration of GET 73 in the first time-in-human manuscript entitled "Phase I randomized clinical trial for the safety, tolerability and preliminary pharmacokinetics of the mGluR5 negative allosteric modulator GET 73 following single and repeated doses in healthy male volunteers" (Haass-Koffler et al., 2017) [1]. Data sets are provided in two different manners. The first series of tables provided includes procedural information about the experiments conducted. The next series of tables provided includes Pharmacokinetic (PK) parameters for GET 73 and its main metabolite MET 2. This set of data is comprised by two experiments: Experiment 1 references a single ascending dose administration of GET 73 and Experiment 2 references a repeated ascending dose administration of GET 73.

  11. Repeat Chlamydia trachomatis testing among heterosexual STI outpatient clinic visitors in the Netherlands: a longitudinal study.

    Science.gov (United States)

    Visser, Maartje; van Aar, Fleur; Koedijk, Femke D H; Kampman, Carolina J G; Heijne, Janneke C M

    2017-12-20

    Chlamydia infections are common in both men and women, are often asymptomatic and can cause serious complications. Repeat testing in high-risk groups is therefore indicated. In the Netherlands, guidelines on repeat chlamydia testing differ between testing facilities, and knowledge on repeat testing behaviour is limited. Here, we analyse the current repeat testing behaviour of heterosexual STI clinic visitors, and aim to identify groups for which repeat testing advice could be advantageous. Longitudinal surveillance data from all Dutch STI outpatient clinics were used, which included all STI clinic consultations carried out among heterosexual men and women between June 2014 and December 2015. Repeat testing was defined as returning to the same STI clinic between 35 days and 12 months after initial consultation. We calculated chlamydia positivity at repeat test stratified by initial test result and time between consultations. Logistic regression analyses were used to identify predictors of repeat testing, and predictors of having a chlamydia positive repeat test. In total, 140,486 consultations in 75,487 women and 46,286 men were available for analyses. Overall, 15.4% of women and 11.1% of men returned to the STI clinic within the study period. Highest chlamydia positivity at repeat test was seen 3-5 months after initial positive test. Among both women and men, repeat testing was associated with non-Western ethnicity, having had more than two sex partners in the past 6 months, reporting STI symptoms, having a history of STI, and having a chlamydia positive initial test. Among repeat testers, chlamydia positive repeat test was most strongly associated with younger age, followed by a chlamydia positive initial test. Repeat testing most often resulted in a positive test result among young heterosexuals (<25) and heterosexuals of any age with a chlamydia infection at the initial consultation. Further efforts are needed to determine optimal repeat testing strategies.

  12. Comparative analysis of transcriptomic responses to repeated-dose exposure to 2-MCPD and 3-MCPD in rat kidney, liver and testis.

    Science.gov (United States)

    Buhrke, Thorsten; Schultrich, Katharina; Braeuning, Albert; Lampen, Alfonso

    2017-08-01

    3-Chloro-1,2-propanediol (3-MCPD) and its isomer 2-chloro-1,3-propanediol (2-MCPD) are heat-induced food contaminants present in oil- and fat-containing foodstuff. Kidney and testes are among the main target organs of 3-MCPD. Almost no data on 2-MCPD toxicity are available. Here, transcriptomic responses following repeated-dose exposure of rats to non-toxic doses of 10 mg/kg body weight per day 2-MCPD or 3-MCPD for 28 days were characterized by microarray analysis of kidney, liver, and testes. 3-MCPD exerted more pronounced effects than 2-MCPD in all organs. The limited overlap between the datasets indicates that 2-MCPD and 3-MCPD do not share the same molecular mechanisms of toxicity. By combining transcriptomic data with datasets on proteomic regulation by 3-MCPD, a comprehensive view on 3-MCPD-induced regulation of glucose utilization and oxidative stress response was developed. Bioinformatic analyses revealed that Nrf2 (nuclear factor (erythroid-derived 2)-like 2) signaling is likely to be involved in mediating the oxidative stress response to 3-MCPD. In summary, this study for the first time presents data on alterations in global gene expression by two important food contaminants, 2-MCPD and 3-MCPD. Data demonstrate profound differences between the effects of the two compounds and substantially broaden our knowledge on molecular details of 3-MCPD-induced disturbance of glucose utilization and redox balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Radiation dose measurement in gastrointestinal studies

    International Nuclear Information System (INIS)

    Sulieman, A.; Elzaki, M.; Kappas, C.; Theodorou, K.

    2011-01-01

    Barium studies investigations (barium swallow, barium meal and barium enema) are the basic routine radiological examination, where barium sulphate suspension is introduced to enhance image contrast of gastrointestinal tracts. The aim of this study was to quantify the patients' radiation doses during barium studies and to estimate the organ equivalent dose and effective dose with those procedures. A total of 33 investigations of barium studies were measured by using thermoluminescence dosemeters. The result showed that the patient entrance surface doses were 12.6±10, 44.5±49 and 35.7±50 mGy for barium swallow, barium meal, follow through and enema, respectively. Effective doses were 0.2, 0.35 and 1.4 mSv per procedure for barium swallow, meal and enema respectively. Radiation doses were comparable with the previous studies. A written protocol for each procedure will reduce the inter-operator variations and will help to reduce unnecessary exposure. (authors)

  14. On model selections for repeated measurement data in clinical studies.

    Science.gov (United States)

    Zou, Baiming; Jin, Bo; Koch, Gary G; Zhou, Haibo; Borst, Stephen E; Menon, Sandeep; Shuster, Jonathan J

    2015-05-10

    Repeated measurement designs have been widely used in various randomized controlled trials for evaluating long-term intervention efficacies. For some clinical trials, the primary research question is how to compare two treatments at a fixed time, using a t-test. Although simple, robust, and convenient, this type of analysis fails to utilize a large amount of collected information. Alternatively, the mixed-effects model is commonly used for repeated measurement data. It models all available data jointly and allows explicit assessment of the overall treatment effects across the entire time spectrum. In this paper, we propose an analytic strategy for longitudinal clinical trial data where the mixed-effects model is coupled with a model selection scheme. The proposed test statistics not only make full use of all available data but also utilize the information from the optimal model deemed for the data. The performance of the proposed method under various setups, including different data missing mechanisms, is evaluated via extensive Monte Carlo simulations. Our numerical results demonstrate that the proposed analytic procedure is more powerful than the t-test when the primary interest is to test for the treatment effect at the last time point. Simulations also reveal that the proposed method outperforms the usual mixed-effects model for testing the overall treatment effects across time. In addition, the proposed framework is more robust and flexible in dealing with missing data compared with several competing methods. The utility of the proposed method is demonstrated by analyzing a clinical trial on the cognitive effect of testosterone in geriatric men with low baseline testosterone levels. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Disposition of diiosononyl phthalate and its effects on sexual development of the male fetus following repeated dosing in pregnant rats.

    Science.gov (United States)

    Clewell, Rebecca A; Sochaski, Mark; Edwards, Kendra; Creasy, Dianne M; Willson, Gabrielle; Andersen, Melvin E

    2013-01-01

    Pregnant Sprague-Dawley rats received 50, 250, and 500 mg/kg/day diisononyl phthalate (DiNP) from GD 12 to 19 via corn oil gavage to study the dose response for effects on fetal male rat sexual development as well as metabolite disposition in the dam and fetus. Monoisononyl phthalate (MiNP), mono(carboxy-isooctyl) phthalate (MCiOP), mono(hydroxyl-isononyl) phthalate (MHiNP), mono(oxo-isononyl) phthalate (MOiNP), and monoisononyl phthalate glucuronide (MiNP-G) were found in all measured tissues. MCiOP was the major metabolite, followed in decreasing order by MiNP, MHiNP, MOiNP, and MiNP-G. Percentage of dose absorbed decreased at 750 mg/kg/day. Testosterone concentration in the fetal testes was reduced at 250 and 750 mg/kg/day. Multinucleated germ cells were increased in the testes of rats at 250 and 750 mg/kg/day. The no observed effect level (NOEL) for this study was 50 mg/kg/day based on increased MNGs and reduced testes testosterone concentration in the fetal rat. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. A study on radiographic repeat rate data of several hospitals in Jeddah

    Energy Technology Data Exchange (ETDEWEB)

    Al-Malki, M.A.; Abulfaraj, W.H.; Bhuiyan, S.I.; Kinsara, A.A

    2003-07-01

    Radiographic repeat rate data in diagnostic radiology in King Fahad Hospital (KFH), King Abdulaziz Hospital (KAH), and Maternity and Children Hospital (MCH) in Jeddah, Saudi Arabia, have been studied. The study provided valuable information to suggest preventive measures to reduce repeats. The variables included in the study are exposure techniques, examination types, total number of films used, number of films repeated, the film sizes, gender, the age groups of the patients, and reason for repetition. The total number of examinations in all three hospitals is 6001 using 8887 films on 5412 patients. The average repeat rate was 7.93%, where the individual hospital repeat rates were 9.57% in the MCH, 7.84% in KAH and 7.44% in KFH. The repeat rate for children and infants was found to be undesirable. The quality assurance (QA) programme can effectively reduce the unnecessary exposure and can identify the cause of the exposure. The overexposure, underexposure and position fault were the foremost contributors for repeats and constitute 32.91%, 28.94% and 22.98% of the total respectively. The QA study identified that human error and equipment malfunction are the major contributors to these causes of repeats. The highest repetition rate was for pelvis, 13.64%, followed by skull, 11.59%, and abdomen, 10.41%. It is estimated that the total area of wasted film in all three hospitals is 74.3 m{sup 2}. As per the average repeat rate, the cost of repeat films in the entire kingdom per year has been projected to be about US$1.82 million (SR 6.83 million) in the government hospitals only. Based on the findings of this study a set of recommendations have been prescribed for the radiology department to reduce the repeat rate and to improve the safety culture. (author)

  17. A study on radiographic repeat rate data of several hospitals in Jeddah

    International Nuclear Information System (INIS)

    Al-Malki, M.A.; Abulfaraj, W.H.; Bhuiyan, S.I.; Kinsara, A.A.

    2003-01-01

    Radiographic repeat rate data in diagnostic radiology in King Fahad Hospital (KFH), King Abdulaziz Hospital (KAH), and Maternity and Children Hospital (MCH) in Jeddah, Saudi Arabia, have been studied. The study provided valuable information to suggest preventive measures to reduce repeats. The variables included in the study are exposure techniques, examination types, total number of films used, number of films repeated, the film sizes, gender, the age groups of the patients, and reason for repetition. The total number of examinations in all three hospitals is 6001 using 8887 films on 5412 patients. The average repeat rate was 7.93%, where the individual hospital repeat rates were 9.57% in the MCH, 7.84% in KAH and 7.44% in KFH. The repeat rate for children and infants was found to be undesirable. The quality assurance (QA) programme can effectively reduce the unnecessary exposure and can identify the cause of the exposure. The overexposure, underexposure and position fault were the foremost contributors for repeats and constitute 32.91%, 28.94% and 22.98% of the total respectively. The QA study identified that human error and equipment malfunction are the major contributors to these causes of repeats. The highest repetition rate was for pelvis, 13.64%, followed by skull, 11.59%, and abdomen, 10.41%. It is estimated that the total area of wasted film in all three hospitals is 74.3 m 2 . As per the average repeat rate, the cost of repeat films in the entire kingdom per year has been projected to be about US$1.82 million (SR 6.83 million) in the government hospitals only. Based on the findings of this study a set of recommendations have been prescribed for the radiology department to reduce the repeat rate and to improve the safety culture. (author)

  18. Repeated irradiations with γ-rays at a dose of 0.5 Gy may exacerbate asthma

    International Nuclear Information System (INIS)

    Fang, Su-ping; Tago, Fumitoshi; Tanaka, Takashi; Simura, Noriko; Kojima, Shuji; Muto, Yasuko; Goto, Resuke

    2005-01-01

    We previously showed that 0.5 Gy whole-body γ-ray irradiation with a single or small number of repeated exposures inhibits tumor growth in mice, via elevation of the IFNγ/IL-4 ratio concomitantly with a decrease in the percentage of B cells. Here we examined whether repeated 0.5 Gy γ-rays irradiation can improve asthma in an ovalbumin (OVA)-induced asthmatic mouse model. We found that repeated irradiation (10 times) with 0.5 Gy of γ-rays significantly increased total IgE in comparison with the disease-control group. The levels of IL-4 and IL-5 were also significantly higher in the γ-ray-irradiated group, while that of IFN-γ was significantly lower, resulting in a further decrease of the IFN-γ/IL-4 ratio from the normal value. These results indicate that the repeated irradiation with γ-rays may exacerbate asthma, and may have opposite effects on different immune reactions unlike the irradiation with a single or small number of repeated exposures. (author)

  19. Analgesia induced by repeated exposure to low dose X-rays in mice, and involvement of the accessory olfactory system in modulation of the radiation effects

    International Nuclear Information System (INIS)

    Miyachi, Yukihisa; Yamada, Takeshi

    1997-01-01

    The effects of low-dose X-rays on mouse nociceptive behavior were examined using a formalin injected test which rated the amount of time the animals spent licking the injected hind-paw. Male ICR White Swiss mice showed a marked suppression of licking behavior after repeated low-dose X-irradiation (5 cGy/day, 6 consecutive days). The most profound effect was observed on the day 30 after irradiation. The decline of licking behavior, however, was not observed at all following olfactory bulbectomy or vomeronasal tract cut. The analgesic effects could be observed in writhing animals administered acetic-acid intraperitoneally. Moreover, analgesia was totally blocked by the administration of N-nitro-L-arginine, a nitric oxide synthase inhibitor, to accessory olfactory bulbs prior to the exposure. The present results indicate that the olfactory system plays an important role in modulation of radiation-induced analgesia, and a possible involvement of nitric oxide in the formation of recognition memory subjected to repeated X-rays. Relatively higher doses (5 cGy x 9 days, 5 cGy x 12 days), however, did not induce such effects, namely, the decline of nociceptive response was limited to the animals irradiated with the smaller dose. (author)

  20. Differential effects of repeated low dose treatment with the cannabinoid agonist WIN 55,212-2 in experimental models of bone cancer pain and neuropathic pain

    DEFF Research Database (Denmark)

    Hald, Andreas; Ding, Ming; Egerod, Kristoffer Lihme

    2008-01-01

    Pain due to bone malignancies is one of the most difficult types of cancer pain to fully control and may further decrease the patients' quality of life. Animal models of chronic pain conditions resulting from peripheral inflammatory reactions or nerve injuries are responsive to treatment with can......Pain due to bone malignancies is one of the most difficult types of cancer pain to fully control and may further decrease the patients' quality of life. Animal models of chronic pain conditions resulting from peripheral inflammatory reactions or nerve injuries are responsive to treatment...... with cannabinoid agonists. However, the use of cannabinoid agonists in humans may be hampered by CNS related side effects and development of tolerance. In the present study, we investigated the effect of repeated low dose administration of the synthetic cannabinoid agonist WIN 55,212-2 on bone cancer pain...... and neuropathic pain in mice. In addition, we investigated the development of CNS related side effects and tolerance. We found that 0.5 mg/kg/day for 18 days reduced pain related behavior and expression of spinal glial fibrillary acidic protein in the bone cancer pain model but not in the neuropathic pain model...

  1. Comparison of image quality in head CT studies with different dose-reduction strategies

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke

    The number of multi-detector CT examinations is increasing rapidly. They allow high quality reformatted images providing accurate and precise diagnosis at maximum speed. Brain examinations are the most commonly requested studies, and although they come at a lower effective dose than body CT, can...... account to a considerable radiation dose as many patients undergo repeated studies. Therefore, various dose-reduction strategies are applied such as automated tube current and voltage modulation and recently different iterative reconstruction algorithms. However, the trade-off of all dose......-reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

  2. Using inter simple sequence repeat (ISSR) markers to study genetic ...

    African Journals Online (AJOL)

    This study shows that ISSR-PCR analysis is quick, reliable and produces sufficient polymorphisms for large-scale DNA fingerprinting purposes. The total of 111 bands of which 60 were polymorphic, (with 54.04%) was amplified by the six primers, an average of seven bands per primer. The total number of amplified ...

  3. t2prhd: a tool to study the patterns of repeat evolution

    Directory of Open Access Journals (Sweden)

    Pénzes Zsolt

    2008-01-01

    Full Text Available Abstract Background The models developed to characterize the evolution of multigene families (such as the birth-and-death and the concerted models have also been applied on the level of sequence repeats inside a gene/protein. Phylogenetic reconstruction is the method of choice to study the evolution of gene families and also sequence repeats in the light of these models. The characterization of the gene family evolution in view of the evolutionary models is done by the evaluation of the clustering of the sequences with the originating loci in mind. As the locus represents positional information, it is straightforward that in the case of the repeats the exact position in the sequence should be used, as the simple numbering according to repeat order can be misleading. Results We have developed a novel rapid visual approach to study repeat evolution, that takes into account the exact repeat position in a sequence. The "pairwise repeat homology diagram" visualizes sequence repeats detected by a profile HMM in a pair of sequences and highlights their homology relations inferred by a phylogenetic tree. The method is implemented in a Perl script (t2prhd available for downloading at http://t2prhd.sourceforge.net and is also accessible as an online tool at http://t2prhd.brc.hu. The power of the method is demonstrated on the EGF-like and fibronectin-III-like (Fn-III domain repeats of three selected mammalian Tenascin sequences. Conclusion Although pairwise repeat homology diagrams do not carry all the information provided by the phylogenetic tree, they allow a rapid and intuitive assessment of repeat evolution. We believe, that t2prhd is a helpful tool with which to study the pattern of repeat evolution. This method can be particularly useful in cases of large datasets (such as large gene families, as the command line interface makes it possible to automate the generation of pairwise repeat homology diagrams with the aid of scripts.

  4. Tools for analyzing genetic variants from sequencing data Case study: short tandem repeats

    OpenAIRE

    Gymrek, Melissa

    2016-01-01

    This was presented as a BitesizeBio Webinar entitled "Tools for analyzing genetic variants from sequencing data Case study: short tandem repeats"Accompanying scripts can be accessed on github:https://github.com/mgymrek/mgymrek-bitesizebio-webinar 

  5. Towards tracer dose reduction in PET studies: Simulation of dose reduction by retrospective randomized undersampling of list-mode data.

    Science.gov (United States)

    Gatidis, Sergios; Würslin, Christian; Seith, Ferdinand; Schäfer, Jürgen F; la Fougère, Christian; Nikolaou, Konstantin; Schwenzer, Nina F; Schmidt, Holger

    2016-01-01

    Optimization of tracer dose regimes in positron emission tomography (PET) imaging is a trade-off between diagnostic image quality and radiation exposure. The challenge lies in defining minimal tracer doses that still result in sufficient diagnostic image quality. In order to find such minimal doses, it would be useful to simulate tracer dose reduction as this would enable to study the effects of tracer dose reduction on image quality in single patients without repeated injections of different amounts of tracer. The aim of our study was to introduce and validate a method for simulation of low-dose PET images enabling direct comparison of different tracer doses in single patients and under constant influencing factors. (18)F-fluoride PET data were acquired on a combined PET/magnetic resonance imaging (MRI) scanner. PET data were stored together with the temporal information of the occurrence of single events (list-mode format). A predefined proportion of PET events were then randomly deleted resulting in undersampled PET data. These data sets were subsequently reconstructed resulting in simulated low-dose PET images (retrospective undersampling of list-mode data). This approach was validated in phantom experiments by visual inspection and by comparison of PET quality metrics contrast recovery coefficient (CRC), background-variability (BV) and signal-to-noise ratio (SNR) of measured and simulated PET images for different activity concentrations. In addition, reduced-dose PET images of a clinical (18)F-FDG PET dataset were simulated using the proposed approach. (18)F-PET image quality degraded with decreasing activity concentrations with comparable visual image characteristics in measured and in corresponding simulated PET images. This result was confirmed by quantification of image quality metrics. CRC, SNR and BV showed concordant behavior with decreasing activity concentrations for measured and for corresponding simulated PET images. Simulation of dose

  6. [Computer optical topography: a study of the repeatability of the results of human body model examination].

    Science.gov (United States)

    Sarnadskiĭ, V N

    2007-01-01

    The problem of repeatability of the results of examination of a plastic human body model is considered. The model was examined in 7 positions using an optical topograph for kyphosis diagnosis. The examination was performed under television camera monitoring. It was shown that variation of the model position in the camera view affected the repeatability of the results of topographic examination, especially if the model-to-camera distance was changed. A study of the repeatability of the results of optical topographic examination can help to increase the reliability of the topographic method, which is widely used for medical screening of children and adolescents.

  7. Needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer evaluated by repeated MRI.

    Science.gov (United States)

    Buus, Simon; Lizondo, Maria; Hokland, Steffen; Rylander, Susanne; Pedersen, Erik M; Tanderup, Kari; Bentzen, Lise

    To quantify needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer and propose a threshold for needle migration. Twenty-four high-risk prostate cancer patients treated with an HDR boost of 2 × 8.5 Gy were included. Patients received an MRI for planning (MRI1), before (MRI2), and after treatment (MRI3). Time from needle insertion to MRI3 was ∼3 hours. Needle migration was evaluated from coregistered images: MRI1-MRI2 and MRI1-MRI3. Dose volume histogram parameters from the treatment plan based on MRI1 were related to parameters based on needle positions in MRI2 or MRI3. Regression was used to model the average needle migration per implant and change in D90 clinical target volume, CTV prostate+3mm . The model fit was used for estimating the dosimetric impact in equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10, 15, and 19 Gy. Needle migration was on average 2.2 ± 1.8 mm SD from MRI1-MRI2 and 5.0 ± 3.0 mm SD from MRI1-MRI3. D90 CTV prostate+3mm was robust toward average needle migration ≤3 mm, whereas for migration >3 mm D90 decreased by 4.5% per mm. A 3 mm of needle migration resulted in a decrease of 0.9, 1.7, 2.3, 4.8, and 7.6 equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10, 15, and 19 Gy, respectively. Substantial needle migration in high-dose-rate brachytherapy occurs frequently in 1-3 hours following needle insertion. A 3-mm threshold of needle migration is proposed, but 2 mm may be considered for dose levels ≥15 Gy. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  8. Development of QSAR models using artificial neural network analysis for risk assessment of repeated-dose, reproductive, and developmental toxicities of cosmetic ingredients.

    Science.gov (United States)

    Hisaki, Tomoka; Aiba Née Kaneko, Maki; Yamaguchi, Masahiko; Sasa, Hitoshi; Kouzuki, Hirokazu

    2015-04-01

    Use of laboratory animals for systemic toxicity testing is subject to strong ethical and regulatory constraints, but few alternatives are yet available. One possible approach to predict systemic toxicity of chemicals in the absence of experimental data is quantitative structure-activity relationship (QSAR) analysis. Here, we present QSAR models for prediction of maximum "no observed effect level" (NOEL) for repeated-dose, developmental and reproductive toxicities. NOEL values of 421 chemicals for repeated-dose toxicity, 315 for reproductive toxicity, and 156 for developmental toxicity were collected from Japan Existing Chemical Data Base (JECDB). Descriptors to predict toxicity were selected based on molecular orbital (MO) calculations, and QSAR models employing multiple independent descriptors as the input layer of an artificial neural network (ANN) were constructed to predict NOEL values. Robustness of the models was indicated by the root-mean-square (RMS) errors after 10-fold cross-validation (0.529 for repeated-dose, 0.508 for reproductive, and 0.558 for developmental toxicity). Evaluation of the models in terms of the percentages of predicted NOELs falling within factors of 2, 5 and 10 of the in-vivo-determined NOELs suggested that the model is applicable to both general chemicals and the subset of chemicals listed in International Nomenclature of Cosmetic Ingredients (INCI). Our results indicate that ANN models using in silico parameters have useful predictive performance, and should contribute to integrated risk assessment of systemic toxicity using a weight-of-evidence approach. Availability of predicted NOELs will allow calculation of the margin of safety, as recommended by the Scientific Committee on Consumer Safety (SCCS).

  9. Effects of annealing on the sensitivity of LiF TLD-100 after repeated use for low dose measurements

    International Nuclear Information System (INIS)

    Ogunleye, O.T.; Richmond, R.G.

    1987-01-01

    The changes in sensitivity of LiF TLD-100 extruded ribbons subjected to repeated use up to 100 times were investigated. Three different annealing regimes were compared. The dosemeters were annealed at 400 0 C followed by (i) a slow or (ii) fast cooling to room temperature or (iii) utilising a 20 s readout process in the reader without a high temperature annealing at 400 0 C. Each of the three groups consisted of two sets of 20 chips each, with one set receiving 500 μ Gy of 90 Sr beta radiation and the other unirradiated. Sensitivity evaluations were performed every five cycles through the first 50 cycles, and on each tenth cycle thereafter. On the average, the fast cooled group maintained their integrity best, while a maximum variation in sensitivity of about 15% was observed in the irradiated set of the slowly cooled group. A permanent increase in sensitivity of at least 10% was observed for the set of dosemeters receiving radiation without annealing. Glow curve analyses showed an increase in the ratio of peaks 4 and 5 with repeated use of this group. (author)

  10. Development of immunity against viral and bacterial antigens after repeated exposures to suberythemal doses of ultraviolet light

    Directory of Open Access Journals (Sweden)

    S. A. Snopov

    2012-01-01

    Full Text Available The effects of ultraviolet (UV radiation on human infectious immunity are not well studied. On the one hand, solar and artificial UU sources have been shown to change cytokine levels in human skin, lymphocyte subpopulation counts in parepheral blood, lymphocyte DNA synthesis and prolifarative response to mitogens. On the other hand, there are just only one or two observations suggesting an influence of UV radiation on human infection course. For instance, UV irradiations have been reported to induce a reccurence of orofacial vesicular lesions caused by herpes siplex virus. Moreover, there is a lack of data concerning immune effects of suberythtemal doses of UV in spite of a long history of using them by Russian prophylactic medicine. In this work we questioned whether such suberythemal UV exposures can affect the immune responses of children to infectious conjunctivitis, to simultaneous measles and polio vaccinations and to simultaneous polio and diphtheria-tetanus vaccinations. In peripheral blood of vaccinated children we examined leukocyte counts (monocytes, neutrophils, eosinophils, lymphocytes, percentages of lymphocyte subpopulations (CD3+, CD20+, CD4+, CD8+, CD25+, HLADR+, concentrations of cytokines (IL-1 beta, TNF-alpha, IFN- amma и IL-10, DNA-synthetic activity of lymphocytes and titres of antibodies against measles and diphtheria toxin. We observed no local or systemic reactions to the vaccines in the UV-group while a moderate rise in body temperature occured in several children from unexposed group. In the blood of childeren from UV-group we found increases in CD25+ и HLADR+ cell percentages, IL- 1 beta and IL-10 concentrations, PWMinduced DNA synthesis in mononuclears, and no decreases in formation of antibodies against measles and diphreria. We concluded that suberythemal UV exposures of children modulated their further responses to imminisations perhaps through the activation of a T helper 2-like

  11. Prediction of response to continuous irradiation at low dose rate for repeated administrations in radiotherapy with beta emitters

    International Nuclear Information System (INIS)

    Calderon, Carlos; Gonzalez, Joaquin; Quesada, Waldo

    2009-01-01

    The absorbed dose to tumors after systemic administration of radiopharmaceuticals is not sufficient to achieve acceptable levels of probability of tumor control without compromising on critical tissue toxicity (kidney and / or bone marrow (BM)). There are reports of trials with multiple administrations, about tolerance level inter-administration intervals to allow recovery of the BM, with good results. The biokinetic behavior of some radiopharmaceuticals known makes possible the application of several administrations with short intervals of time.It is the present work combines two kinetic models of tumor growth and cell kinetics in the BM for predicting the response to continuous irradiation at low dose rate. The estimation of the effects of irradiation on tumor and kidneys was done using a formulation of the linear-quadratic model functions suitable for dose rate and multi-exponential repair. The estimation of the response in WB performed using a compartmental model previously reported. The absorbed dose to organs were calculated using the MIRD formulation taking into account the effect of irradiation cross. Biokinetic data were used for therapeutic radiopharmaceuticals 90Y, 131I and 177Lu, as well as radiobiological parameters reported for experimental animals. The effect on the response by the variation of inter-administration interval in slow-growing tumors and fast, so as the radiosensitive and radioresistant tumors. You can set conditions irradiation to an acceptable level of thrombocytopenia (onset and duration of the minimum in the curve) and renal irradiation below the limit of tolerance. It is possible to design experiments evaluation of therapeutic radiopharmaceuticals with a greater degree of refinement. (author)

  12. Computational study of the human dystrophin repeats: interaction properties and molecular dynamics.

    Directory of Open Access Journals (Sweden)

    Baptiste Legrand

    Full Text Available Dystrophin is a large protein involved in the rare genetic disease Duchenne muscular dystrophy (DMD. It functions as a mechanical linker between the cytoskeleton and the sarcolemma, and is able to resist shear stresses during muscle activity. In all, 75% of the dystrophin molecule consists of a large central rod domain made up of 24 repeat units that share high structural homology with spectrin-like repeats. However, in the absence of any high-resolution structure of these repeats, the molecular basis of dystrophin central domain's functions has not yet been deciphered. In this context, we have performed a computational study of the whole dystrophin central rod domain based on the rational homology modeling of successive and overlapping tandem repeats and the analysis of their surface properties. Each tandem repeat has very specific surface properties that make it unique. However, the repeats share enough electrostatic-surface similarities to be grouped into four separate clusters. Molecular dynamics simulations of four representative tandem repeats reveal specific flexibility or bending properties depending on the repeat sequence. We thus suggest that the dystrophin central rod domain is constituted of seven biologically relevant sub-domains. Our results provide evidence for the role of the dystrophin central rod domain as a scaffold platform with a wide range of surface features and biophysical properties allowing it to interact with its various known partners such as proteins and membrane lipids. This new integrative view is strongly supported by the previous experimental works that investigated the isolated domains and the observed heterogeneity of the severity of dystrophin related pathologies, especially Becker muscular dystrophy.

  13. The Enigma of Rapid Repeat Pregnancy: A Qualitative Study of Teen Mothers.

    Science.gov (United States)

    Conroy, K N; Engelhart, T G; Martins, Y; Huntington, N L; Snyder, A F; Coletti, K D; Cox, J E

    2016-06-01

    Rapid repeat pregnancy accounts for 18% of teen pregnancies and leads to adverse health, economic, and developmental outcomes for teen mothers and their children. Few interventions have been successful in reducing rapid repeat pregnancy. In this qualitative study we examined adolescent mothers' perceptions of their decision-making and behaviors that helped prevent or promote a rapid repeat pregnancy. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: Semistructured interviews were conducted with 31 adolescent mothers, aged 16-21 years; 15 of these subjects experienced a repeat pregnancy within a year of their first child's birth and 16 had not. Two researchers used a grounded, inductive technique to identify emergent themes; interviews were subsequently coded accordingly. Counts were tabulated of the number of times themes were endorsed among those with or without a repeat pregnancy. Four overarching themes emerged from the interviews: intentionality regarding pregnancy planning, patients' degree of independence in making contraceptive choices, sense of control over life experience, and barriers to follow-through on contraceptive planning. Teens who had not experienced a rapid repeat pregnancy more often endorsed themes of intentionality in preventing or promoting a pregnancy, independence in decision-making, and feelings of control over their experience. Ambivalence and lack of decision-making about seeking another pregnancy were frequently endorsed by mothers who had experienced a second pregnancy. Decision-making regarding seeking or preventing a rapid repeat pregnancy is complex for teen mothers; techniques to help support decision-making or to delay pregnancy until decision-repeat making is complete might be important in reducing rapid pregnancy. Copyright © 2015 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

  14. The Study on the Ferrokinetics and Acquired Immunity in Repeated Hookworm Infections

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mun Ho; Lee, Pyl Ung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1967-09-15

    In order to confirm whether acquired immunity or resistance can be developed by the repeated hookworm infections, the 150 mature actively moving filariform ancylostoma duodenale larvae obtained from the severe hookworm anemia patients were orally given to 8 healthy volunteers in three divided doses, 50 in each, at 5 day interval. Also the hematological changes as well as several ferrokinetics using {sup 59}Fe were done and were compared with 10 controls. The clinical symptoms and signs were checked every day for the first 3 weeks and then twice weekly until the end of the experiment. The appearance of the ova in the stool was examined by the formalin ether method and the ova was counted by the Stoll's method. The following laboratory tests were done:1) Red blood cell count, venous blood hematocrit (micromethod), hemoglobin count (cyanomethemoglobin method) were checked every 5 to 7 day interval. 2) Plasma iron concentration (Barkan's modified method) was determined every 2 to 3 week interval. 3) Radioisotope studies:a) Ferrokinetics: Huff et al and Bothwell's method were applied. Erythropoietic Index (% of normal)= ['Subject's turnover/100 ml whole bloodX100'] over ['Average normal turnover/100 ml whole blood'] b) Quantitative measurement of the gastrointestinal absorption of iron:Radioiron ({sup 59}Fe) balance method was applied. c) Determination of the plasma erythropoietin activity: Fried's method was applied. Following were the results: 1) The serum iron level was lower. The red cell volume was decreased, but with relative increase of plasma volume. 2) The plasma iron disappearance time was accelerated and the plasma iron turnover rate was decreased. The red cell iron turnover rate was markedly increased, while all of the red cell iron concentration, circulating red cell iron, plasma iron pool were decreased. The daily iron pool turnover and red cell renewal rate were increased. 3) The erythropoietic index, erythropoietin activity and intestinal absorption of

  15. The Study on the Ferrokinetics and Acquired Immunity in Repeated Hookworm Infections

    International Nuclear Information System (INIS)

    Lee, Mun Ho; Lee, Pyl Ung

    1967-01-01

    In order to confirm whether acquired immunity or resistance can be developed by the repeated hookworm infections, the 150 mature actively moving filariform ancylostoma duodenale larvae obtained from the severe hookworm anemia patients were orally given to 8 healthy volunteers in three divided doses, 50 in each, at 5 day interval. Also the hematological changes as well as several ferrokinetics using 59 Fe were done and were compared with 10 controls. The clinical symptoms and signs were checked every day for the first 3 weeks and then twice weekly until the end of the experiment. The appearance of the ova in the stool was examined by the formalin ether method and the ova was counted by the Stoll's method. The following laboratory tests were done:1) Red blood cell count, venous blood hematocrit (micromethod), hemoglobin count (cyanomethemoglobin method) were checked every 5 to 7 day interval. 2) Plasma iron concentration (Barkan's modified method) was determined every 2 to 3 week interval. 3) Radioisotope studies:a) Ferrokinetics: Huff et al and Bothwell's method were applied. Erythropoietic Index (% of normal)= [ S ubject's turnover/100 ml whole bloodX100 ] over [ A verage normal turnover/100 ml whole blood ] b) Quantitative measurement of the gastrointestinal absorption of iron:Radioiron ( 59 Fe) balance method was applied. c) Determination of the plasma erythropoietin activity: Fried's method was applied. Following were the results: 1) The serum iron level was lower. The red cell volume was decreased, but with relative increase of plasma volume. 2) The plasma iron disappearance time was accelerated and the plasma iron turnover rate was decreased. The red cell iron turnover rate was markedly increased, while all of the red cell iron concentration, circulating red cell iron, plasma iron pool were decreased. The daily iron pool turnover and red cell renewal rate were increased. 3) The erythropoietic index, erythropoietin activity and intestinal absorption of iron

  16. Repeat film analysis and its implications for quality assurance in dental radiology: An institutional case study

    Directory of Open Access Journals (Sweden)

    Shruthi Acharya

    2015-01-01

    Full Text Available Context: The goal of any radiologist is to produce the highest quality diagnostic radiographs, while keeping patient exposure as low as reasonably achievable (ALARA. Aims: The aim of this study was to describe the reasons for radiograph rejections through a repeat film analysis in an Indian dental school. Settings and Design: An observational study conducted in the Department of Oral Medicine and Radiology, Manipal College of Dental Sciences, Manipal. Materials and Methods: During a 6-month study period, a total of 9,495 intra-oral radiographs and 2339 extraoral radiographs taken in the Radiology Department were subjected to repeat film analysis. Statistical Analysis Used: SPSS Version 16. Descriptive analysis used. Results: The results showed that the repeat rates were 7.1% and 5.86% for intraoral and extraoral radiographs, respectively. Among the causes for errors reported, positioning error (38.7% was the most common, followed by improper angulations (26.1%, and improper film placement (11.2% for intra-oral radiographs. The study found that the maximum frequency of repeats among extraoral radiographs was for panoramic radiographs (49% followed by lateral cephalogram (33%, and paranasal sinus view (14%. It was also observed that repeat rate of intraoral radiographs was highest for internees (44.7%, and undergraduate students (28.2%. Conclusions: The study pointed to a need for more targeted interventions to achieve the goal of keeping patient exposure ALARA in a dental school setting.

  17. Topographical distribution of decrements and recovery in muscarinic receptors from rat brains repeatedly exposed to sublethal doses of soman

    International Nuclear Information System (INIS)

    Churchill, L.; Pazdernik, T.L.; Jackson, J.L.; Nelson, S.R.; Samson, F.E.; McDonough, J.H. Jr.

    1984-01-01

    [3H]Quinuclidinyl benzilate binding to rat brain muscarinic receptors decreased after repeated exposure to soman, a potent organophosphorus cholinesterase inhibitor. The topographical distribution of this decrement was analyzed by quantitative receptor autoradiography. After 4 weeks of soman, three times a week, quinuclidinyl benzilate binding decreased to 67 to 80% of control in frontal and parietal cortex, caudate-putamen, lateral septum, hippocampal body, dentate gyrus, superior colliculus, nucleus of the fifth nerve, and central grey. Minor or no decreases were observed in thalamic or hypothalamic nuclei, reticular formation, pontine nuclei, inferior colliculus, nucleus of the seventh nerve, and cerebellum. Scatchard analyses of saturation curves using frontal cortex sections from soman-treated rats revealed a decrease in maximal quinuclidinyl benzilate binding from that in control rats and a return toward control levels by 24 days without any significant change in affinity. These brain areas showing significant decrements in muscarinic receptors recovered with a similar time course. An estimate of the time for 50% recovery for some of the brain areas was 14 days for superior colliculus, 16 days for cortex, and 19 days for hippocampal body. The application of quantitative receptor autoradiography to analyze receptor alterations has been valuable in localizing the telencephalon as a region more susceptible to change in receptor concentration

  18. Topographical distribution of decrements and recovery in muscarinic receptors from rat brains repeatedly exposed to sublethal doses of soman

    Energy Technology Data Exchange (ETDEWEB)

    Churchill, L.; Pazdernik, T.L.; Jackson, J.L.; Nelson, S.R.; Samson, F.E.; McDonough, J.H. Jr.

    1984-08-01

    (3H)Quinuclidinyl benzilate binding to rat brain muscarinic receptors decreased after repeated exposure to soman, a potent organophosphorus cholinesterase inhibitor. The topographical distribution of this decrement was analyzed by quantitative receptor autoradiography. After 4 weeks of soman, three times a week, quinuclidinyl benzilate binding decreased to 67 to 80% of control in frontal and parietal cortex, caudate-putamen, lateral septum, hippocampal body, dentate gyrus, superior colliculus, nucleus of the fifth nerve, and central grey. Minor or no decreases were observed in thalamic or hypothalamic nuclei, reticular formation, pontine nuclei, inferior colliculus, nucleus of the seventh nerve, and cerebellum. Scatchard analyses of saturation curves using frontal cortex sections from soman-treated rats revealed a decrease in maximal quinuclidinyl benzilate binding from that in control rats and a return toward control levels by 24 days without any significant change in affinity. These brain areas showing significant decrements in muscarinic receptors recovered with a similar time course. An estimate of the time for 50% recovery for some of the brain areas was 14 days for superior colliculus, 16 days for cortex, and 19 days for hippocampal body. The application of quantitative receptor autoradiography to analyze receptor alterations has been valuable in localizing the telencephalon as a region more susceptible to change in receptor concentration.

  19. Comparative study of eye dose and chest dose received during radiopharmaceutical production processes

    International Nuclear Information System (INIS)

    Chindarkar, A.S.; Chavan, S.V.; Sawant, D.K.; Sahoo, L.; Gopalakrishnan, R.K.; Sneha, C.; Sachdev, S.S.; Dey, A.C.

    2018-01-01

    Radiopharmaceutical laboratory, BRIT, Vashi produces different radiopharmaceuticals of 131 I, 153 Sm, 99 Mo/ 99m Tc and 177 Lu. Principle gamma energies of these isotopes vary from 103 to 740 KeV and their maximum beta energies vary from 384 to 1214 KeV. In the light of the revised eye lens dose limit recommended in IAEA Basic Safety Standard Interim Edition No. GSR Part 3 (IAEA-2011), the study of radiation dose for eye lens was carried out using CaSO 4 : Dy based Thermo luminescence dosimeter (TLD). This TLD was worn at center of the forehead to measure eye lens dose. This TLD dose was then compared with chest TLD dose to deduce any correlation between these TLD doses. These TLD doses were assessed on quarterly basis. Eight quarter data of these TLD doses were compared

  20. Maintaining confidentiality in prospective studies: anonymous repeated measurements via email (ARME) procedure.

    Science.gov (United States)

    Carli, Vladimir; Hadlaczky, Gergö; Wasserman, Camilla; Stingelin-Giles, Nicola; Reiter-Theil, Stella; Wasserman, Danuta

    2012-02-01

    Respecting and protecting the confidentiality of data and the privacy of individuals regarding the information that they have given as participants in a research project is a cornerstone of complying with accepted research standards. However, in longitudinal studies, establishing and maintaining privacy is often challenging because of the necessity of repeated contact with participants. A novel internet-based solution is introduced here, which maintains privacy while at the same time ensures linkage of data to individual participants in a repeated measures design. With the use of the anonymous repeated measurements via email (ARME) procedure, two separate one-way communication systems are established through ad hoc email accounts and a secure study website. Strengths and limitations of the approach are discussed.

  1. A study on gamma dose rate in Seoul (I)

    International Nuclear Information System (INIS)

    Kim, You Hyun; Kim, Chang Kyun; Choi, Jong Hak; Kim, Jeong Min

    2001-01-01

    This study was conducted to find out gamma dose rate in Seoul, from January to December in 2000, and the following results were achieved : The annual gamma dose rate in Seoul was 17.24 μR/hr as average. The annual gamma dose rate in subway of Seoul was 14.96 μR/hr as average. The highest annual gamma dose rate was Dong-daemon ku. Annual gamma dose rate in Seoul was higher autumn than winter

  2. Serological analysis of human anti-human antibody responses in colon cancer patients treated with repeated doses of humanized monoclonal antibody A33.

    Science.gov (United States)

    Ritter, G; Cohen, L S; Williams, C; Richards, E C; Old, L J; Welt, S

    2001-09-15

    Mouse monoclonal antibody A33 (mAb A33) recognizes a M(r) 43,000 cell surface glycoprotein (designated A33) expressed in human colonic epithelium and colon cancer but absent from most other normal tissues. In patients, mAb A33 localizes with high specificity to colon cancer and is retained for up to 6 weeks in the cancer but cleared rapidly from normal colon (5-6 days). As a carrier of (125)I or (131)I, mAb A33 has shown antitumor activity. Induction of strong human anti-mouse antibody (immunoglobulin; HAMA) responses in patients, however, limits the use of the murine mAb A33 to very few injections. A humanized version of this antibody (huAb A33) has been prepared for Phase I and II clinical studies in patients with colon cancer. In those studies, immunogenicity of huAb A33 has been monitored using a novel, highly sensitive BIACORE method, which allows measurement of human anti-human antibodies (HAHAs) without the use of secondary reagents. We found that 63% (26 of 41) of the patients treated with repeated doses of huAb A33 developed HAHAs against a conformational antigenic determinant located in the V(L) and V(H) regions of huAb A33. Detailed serological analysis showed two distinct types of HAHAs. HAHA of type I (49% of patients) was characterized by an early onset with peak HAHA levels after 2 weeks of treatment, which declined with ongoing huAb A33 treatment. HAHA of type II (17% of patients) was characterized by a typically later onset of HAHA than in type I and by progressively increasing HAHA levels with each subsequent huAb A33 administration. Colon cancer patients with type I HAHAs did not develop infusion-related adverse events. In contrast, HAHA of type II was indicative of infusion-related adverse events. By using this new method, we were able to distinguish these two types of HAHAs in patients while on antibody treatment, allowing patients to be removed from study prior to the onset of severe infusion-related adverse events.

  3. Comparative study of radioprotective properties of serotin derivatives repeatedly applied before gamma irradiation

    International Nuclear Information System (INIS)

    Gorelova, N.V.; Antipov, V.V.; Vasin, M.V.

    1977-01-01

    In the experiments on albino mice, the phenomenon of desensitization has been studied by a specific activity and some pharmacologic properties of serotonin, mexamin and 5-acetyloxytryptamine, the time-intervals between injections of the preparations being 5, 30 and 60 minutes, 2, 3, 4, 6, 8 and 24 hours. A correlation has been found between changes in radioprotective and pharmacologic properties (as determined by the accumulation of the dye in the splenic tissue) after repeated administration of mexamin. The phenomenon of desensitization is probably dependent not only on the chemical nature and mechanism of action of the protectors but also on the conditions under which they are repeatedly applied

  4. Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides

    Science.gov (United States)

    Long, Edward R., Jr.; Long, Sheila Ann T.; Gray, Stephanie L.; Collins, William D.

    1989-01-01

    The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures.

  5. Chip-based human liver-intestine and liver-skin co-cultures--A first step toward systemic repeated dose substance testing in vitro.

    Science.gov (United States)

    Maschmeyer, Ilka; Hasenberg, Tobias; Jaenicke, Annika; Lindner, Marcus; Lorenz, Alexandra Katharina; Zech, Julie; Garbe, Leif-Alexander; Sonntag, Frank; Hayden, Patrick; Ayehunie, Seyoum; Lauster, Roland; Marx, Uwe; Materne, Eva-Maria

    2015-09-01

    Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called "human-on-a-chip" concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms. The major technical hurdle toward success in this field is the life-like combination of human barrier organ models, such as intestine, lung or skin, with parenchymal organ equivalents, such as liver, at the smallest biologically acceptable scale. Here, we report on a reproducible homeostatic long-term co-culture of human liver equivalents with either a reconstructed human intestinal barrier model or a human skin biopsy applying a microphysiological system. We used a multi-organ chip (MOC) platform, which provides pulsatile fluid flow within physiological ranges at low media-to-tissue ratios. The MOC supports submerse cultivation of an intact intestinal barrier model and an air-liquid interface for the skin model during their co-culture with the liver equivalents respectively at (1)/100.000 the scale of their human counterparts in vivo. To increase the degree of organismal emulation, microfluidic channels of the liver-skin co-culture could be successfully covered with human endothelial cells, thus mimicking human vasculature, for the first time. Finally, exposure routes emulating oral and systemic administration in humans have been qualified by applying a repeated dose administration of a model substance - troglitazone - to the chip-based co-cultures. Copyright © 2015. Published by Elsevier B.V.

  6. Georgia fishery study: implications for dose calculations

    International Nuclear Information System (INIS)

    Turcotte, M.D.S.

    1983-01-01

    Fish consumption will contribute a major portion of the estimated individual and population doses from L-Reactor liquid releases and Cs-137 remobilization in Steel Creek. It is therefore important that the values for fish consumption used in dose calculations be as realistic as possible. Since publication of the L-Reactor Environmental Information Document (EID), data have become available on sport fishing in the Savannah River. These data provide SRP with site-specific sport fish harvest and consumption values for use in dose calculations. The Georgia fishery data support the total population fish consumption and calculated dose reported in the EID. The data indicate, however, that both the EID average and maximum individual fish consumption have been underestimated, although each to a different degree. The average fish consumption value used in the EID is approximately 3% below the lower limit of the fish consumption range calculated using the Georgia data. A fish consumption value of 11.3 kg/yr should be used to recalculate dose to the average individual from L-Reactor restart. Maximum fish consumption in the EID has been underestimated by approximately 60%, and doses to the maximum individual should also be recalculated. Future dose calculations should utilize an average fish consumption value of 11.3 kg/yr, and a maximum fish consumption value of 34 kg/yr

  7. Impact of Single or Repeated Dose Intranasal Zinc-free Insulin in Young and Aged F344 Rats on Cognition, Signaling, and Brain Metabolism.

    Science.gov (United States)

    Anderson, Katie L; Frazier, Hilaree N; Maimaiti, Shaniya; Bakshi, Vikas V; Majeed, Zana R; Brewer, Lawrence D; Porter, Nada M; Lin, Ai-Ling; Thibault, Olivier

    2017-02-01

    Novel therapies have turned to delivering compounds to the brain using nasal sprays, bypassing the blood brain barrier, and enriching treatment options for brain aging and/or Alzheimer's disease. We conducted a series of in vivo experiments to test the impact of intranasal Apidra, a zinc-free insulin formulation, on the brain of young and aged F344 rats. Both single acute and repeated daily doses were compared to test the hypothesis that insulin could improve memory recall in aged memory-deficient animals. We quantified insulin signaling in different brain regions and at different times following delivery. We measured cerebral blood flow (CBF) using MRI and also characterized several brain metabolite levels using MR spectroscopy. We show that neither acute nor chronic Apidra improved memory or recall in young or aged animals. Within 2 hours of a single dose, increased insulin signaling was seen in ventral areas of the aged brains only. Although chronic Apidra was able to offset reduced CBF with aging, it also caused significant reductions in markers of neuronal integrity. Our data suggest that this zinc-free insulin formulation may actually hasten cognitive decline with age when used chronically. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Randomized, controlled, assessor-blind clinical trial to assess the efficacy of single- versus repeated-dose albendazole to treat ascaris lumbricoides, trichuris trichiura, and hookworm infection.

    Science.gov (United States)

    Adegnika, Ayola A; Zinsou, Jeannot F; Issifou, Saadou; Ateba-Ngoa, Ulysse; Kassa, Roland F; Feugap, Eliane N; Honkpehedji, Yabo J; Dejon Agobe, Jean-Claude; Kenguele, Hilaire M; Massinga-Loembe, Marguerite; Agnandji, Selidji T; Mordmüller, Benjamin; Ramharter, Michael; Yazdanbakhsh, Maria; Kremsner, Peter G; Lell, Bertrand

    2014-05-01

    In many regions where soil-transmitted helminth infections are endemic, single-dose albendazole is used in mass drug administration programs to control infections. There are little data on the efficacy of the standard single-dose administration compared to that of alternative regimens. We conducted a randomized, controlled, assessor-blinded clinical trial to determine the efficacies of standard and extended albendazole treatment against soil-transmitted helminth infection in Gabon. A total of 175 children were included. Adequate cure rates and egg reduction rates above 85% were found with a single dose of albendazole for Ascaris infection, 85% (95% confidence interval [CI], 73, 96) and 93.8% (CI, 87.6, 100), respectively, while two doses were necessary for hookworm infestation (92% [CI, 78, 100] and 92% [CI, 78, 100], respectively). However, while a 3-day regimen was not sufficient to cure Trichuris (cure rate, 83% [CI, 73, 93]), this regimen reduced the number of eggs up to 90.6% (CI, 83.1, 100). The rate ratios of two- and three-dose regimens compared to a single-dose treatment were 1.7 (CI, 1.1, 2.5) and 2.1 (CI, 1.5, 2.9) for Trichuris and 1.7 (CI, 1.0, 2.9) and 1.7 (CI, 1.0, 2.9) for hookworm. Albendazole was safe and well tolerated in all regimens. A single-dose albendazole treatment considerably reduces Ascaris infection but has only a moderate effect on hookworm and Trichuris infections. The single-dose option may still be the preferred regimen because it balances efficacy, safety, and compliance during mass drug administration, keeping in mind that asymptomatic low-level helminth carriage may also have beneficial effects. (This study has been registered at ClinicalTrials.gov under registration number NCT01192802.).

  9. Topics on study of low dose-effect relationship

    International Nuclear Information System (INIS)

    Yamada, Takeshi; Ohyama, Harumi

    1999-01-01

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

  10. An epidemiological study for the reduction of population radiation dose

    International Nuclear Information System (INIS)

    Gamo, Makoto

    1989-01-01

    The correlation of tube voltage with patient exposure was studied using effective dose as an indicator of dose reduction in intraoral radiography. The results were as follows: l. The salivary gland tissues contributed the most to the effective dose of intraoral radiography. 2. In the 50 to 90 kV range, there was no appreciable correlation between tube voltage and effective dose. 3. Therefore, it was suggested that adjusting the tube voltage for maximum image quality does not effect radiation protection. 4. This study reconfirmed the fact that increases in voltages up to 90 kV reduce skin doses. (author)

  11. Dose reduction and optimization studies (ALARA) at nuclear power facilities

    International Nuclear Information System (INIS)

    Baum, J.W.; Meinhold, C.B.

    1983-01-01

    Brookhaven National Laboratory (BNL) has been commissioned by the Nuclear Regulatory Commission (NRC) to study dose-reduction techniques and effectiveness of as low as reasonably achievable (ALARA) planning at LWR plants. These studies have the following objectives: identify high-dose maintenance tasks; identify dose-reduction techniques; examine incentives for dose reduction; evaluate cost-effectiveness and optimization of dose-reduction techniques; and compile an ALARA handbook on data, engineering modifications, cost-effectiveness calculations, and other information of interest to ALARA practioners

  12. Repeated vertebral augmentation for new vertebral compression fractures of postvertebral augmentation patients: a nationwide cohort study

    Directory of Open Access Journals (Sweden)

    Liang CL

    2015-03-01

    Full Text Available Cheng-Loong Liang,1 Hao-Kwan Wang,1 Fei-Kai Syu,2 Kuo-Wei Wang,1 Kang Lu,1 Po-Chou Liliang1 1Department of Neurosurgery, E-Da Hospital, I-Shou University, Kaohsiung City, Taiwan; 2Department of Pharmacy, China Medical University Hospital, Taichung City, Taiwan Purpose: Postvertebral augmentation vertebral compression fractures are common; repeated vertebral augmentation is usually performed for prompt pain relief. This study aimed to evaluate the incidence and risk factors of repeat vertebral augmentation.Methods: We performed a retrospective, nationwide, population-based longitudinal observation study, using the National Health Insurance Research Database (NHIRD of Taiwan. All patients who received vertebral augmentation for vertebral compression fractures were evaluated. The collected data included patient characteristics (demographics, comorbidities, and medication exposure and repeat vertebral augmentation. Kaplan–Meier and stratified Cox proportional hazard regressions were performed for analyses.Results: The overall incidence of repeat vertebral augmentation was 11.3% during the follow-up until 2010. Patients with the following characteristics were at greater risk for repeat vertebral augmentation: female sex (AOR=1.24; 95% confidence interval [CI]: 1.10–2.36, advanced age (AOR=1.60; 95% CI: 1.32–2.08, diabetes mellitus (AOR=4.31; 95% CI: 4.05–5.88, cerebrovascular disease (AOR=4.09; 95% CI: 3.44–5.76, dementia (AOR=1.97; 95% CI: 1.69–2.33, blindness or low vision (AOR=3.72; 95% CI: 2.32–3.95, hypertension (AOR=2.58; 95% CI: 2.35–3.47, and hyperlipidemia (AOR=2.09; 95% CI: 1.67–2.22. Patients taking calcium/ vitamin D (AOR=2.98; 95% CI: 1.83–3.93, bisphosphonates (AOR=2.11; 95% CI: 1.26–2.61, or calcitonin (AOR=4.59; 95% CI: 3.40–5.77 were less likely to undergo repeat vertebral augmentation; however, those taking steroids (AOR=7.28; 95% CI: 6.32–8.08, acetaminophen (AOR=3.54; 95% CI: 2.75–4.83, or nonsteroidal

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  14. Action of 50 R X-ray doses on the breeding function of C3H strain mice - effect of splitting the dose, action of repeated irradiations on successive generations

    International Nuclear Information System (INIS)

    Alix, D.

    1965-01-01

    X-rays exposure effect was studied on C3H strain mice, at the standpoint of the effects produced on breeding function. The method used with this purpose was the following: single doses 20 - 30 - 40 and 50 R/dose, fractional doses: 50 R/total dose, divided in 2 - 5 - 10 or 25 irradiations distributed in one month duration. The offsprings were irradiated at the same doses than the parents, consanguinity being maintained. Statistical treatment of results was carried out, that led at the following conclusions: 1) Couples receiving single exposure of 50 R or two exposures of 25 R at one month interval give comparable results. Fractional doses do not involve the slightest diminution of X-rays effect. 2) 30 R exposure brings about a decrease in fertility, with an increase in abortions. Fertility of 20 R irradiated couples remains below controls. 3) After ten times 5 R and twenty-five 2 R, the number of abortions is the largest. Ovarian function is particularly sensitive to X-rays; one may think that twenty-five 2 R give injuries conditioning non-viability of conception products, smaller doses should produce mutations and yield births of altered genotype individuals. (author) [fr

  15. Radiation dose to the patient in radionuclide studies

    International Nuclear Information System (INIS)

    Roedler, H.D.

    1981-01-01

    In medical radionuclide studies, the radiation risk has to be considered in addition to the general risk of administering a pharmaceutical. As radiation exposure is an essential factor in radiation risk estimation, some aspects of internal dose calculation, including radiation risk assessments, are treated. The formalism of current internal dose calculation is presented. The input data, especially the residence time and the absorbed dose per transformation, their origin and accuracy are discussed. Results of internal dose calculations for the ten most frequently used radionuclide studies are presented as somatically effective dose equivalents. The accuracy of internal dose calculation is treated in detail by considering the biokinetics of the radiopharmaceutical, the phantoms used for dose calculations, the absorbed dose per transformation, the administered activity, and the transfer of the dose, calculated for a phantom, to the patient. The internal dose calculated for a reference phantom may be assumed to be in accordance with the actual patient dose within a range described by a factor of about two to three. Finally, risk estimates for nuclear medicine procedures are quantified, being generally of sixth order. The radiation risk from the radioiodine test is comparably higher, but probably lower than calculated according to the UNSCEAR risk coefficients. However, further studies are needed to confirm these preliminary results and to improve the quantification of the radiation risk from the medical use of radionuclides. (author)

  16. Study of Optimal Perimetric Testing in Children (OPTIC: Feasibility, Reliability and Repeatability of Perimetry in Children.

    Directory of Open Access Journals (Sweden)

    Dipesh E Patel

    Full Text Available To investigate feasibility, reliability and repeatability of perimetry in children.A prospective, observational study recruiting 154 children aged 5-15 years, without an ophthalmic condition that affects the visual field (controls, identified consecutively between May 2012 and November 2013 from hospital eye clinics. Perimetry was undertaken in a single sitting, with standardised protocols, in a randomised order using the Humphrey static (SITA 24-2 FAST, Goldmann and Octopus kinetic perimeters. Data collected included test duration, subjective experience and test quality (incorporating examiner ratings on comprehension of instructions, fatigue, response to visual and auditory stimuli, concentration and co-operation to assess feasibility and reliability. Testing was repeated within 6 months to assess repeatability.Overall feasibility was very high (Goldmann=96.1%, Octopus=89% and Humphrey=100% completed the tests. Examiner rated reliability was 'good' in 125 (81.2% children for Goldmann, 100 (64.9% for Octopus and 98 (63.6% for Humphrey perimetry. Goldmann perimetry was the most reliable method in children under 9 years of age. Reliability improved with increasing age (multinomial logistic regression (Goldmann, Octopus and Humphrey, p<0.001. No significant differences were found for any of the three test strategies when examining initial and follow-up data outputs (Bland-Altman plots, n=43, suggesting good test repeatability, although the sample size may preclude detection of a small learning effect.Feasibility and reliability of formal perimetry in children improves with age. By the age of 9 years, all the strategies used here were highly feasible and reliable. Clinical assessment of the visual field is achievable in children as young as 5 years, and should be considered where visual field loss is suspected. Since Goldmann perimetry is the most effective strategy in children aged 5-8 years and this perimeter is no longer available, further

  17. Repeated sub-chronic oral toxicity study of xylooligosaccharides (XOS) in dogs.

    Science.gov (United States)

    Gao, Yonglin; Wang, Yunzhi; Li, Yanshen; Han, Rui; Li, Chunmei; Xiao, Lin; Cho, Susan; Ma, Yukui; Fang, Chao; Lee, Albert W

    2017-06-01

    In this study, Beagle dogs were administered xylooligosaccharide (XOS, CAS # 87099-0) at doses of 0, 1250, 2500, and 5000 mg/kg/day by oral gavage for 26 weeks. A 4-week recovery period was added to observe delayed or reversible toxicity. Measurements included body weight, food consumption, clinical observations, temperature, electrocardiogram (ECG), urinalysis, blood chemistry, hematology, organ weight, gross necropsy, and histopathological examination. Except for transient diarrhea or vomiting, no treatment-related adverse effects were noted. In the mid-dose groups, transitional diarrhea was observed in the initial 1-2 weeks. In the high-dose groups, diarrhea and/or vomiting were observed episodically over the duration of treatment. However, they disappeared after XOS was withdrawn in the recovery period. Although there was a tendency toward less weight gain in the high-dose group animal group, this is typical in animals and humans fed non-digestible carbohydrates. This chronic toxicity study demonstrated that the no observed adverse effect level (NOAEL) of XOS is 2500 mg/kg body weight (BW)/day. Based on body surface area (conversion factor of 0.54 for dogs to human), this corresponds to daily doses of 1350 mg/kg BW or 81-108 g XOS in human adults weighing 60-80 kg. Copyright © 2017. Published by Elsevier Inc.

  18. Preliminary study of using imaging plates to map skin dose of patients in interventional radiology procedures

    International Nuclear Information System (INIS)

    Ohuchi, H.; Satoh, T.; Eguchi, Y.; Mori, K.

    2005-01-01

    A method using europium-doped BaFBr imaging plates (IPs) has been studied for mapping entrance skin doses during interventional radiology (IR); the mapping is useful for detecting overlap between irradiation fields and determining the most exposed skin areas. IPs, which are two-dimensional radiation sensors made of photostimulated luminescence materials, have a linear dose response up to ∼100 Gy, can accurately measure doses from 1 μGy to 10 Gy and can be used repeatedly. Because the energy dependence of IPs is rather high, the IPs were characterised in this study and a sensitivity variation of ∼13% was observed for effective energies of 32.7 to 44.7 keV, which are used in IR procedures. Simulation of actual interventional cardiology procedures showed that the variation of sensitivity was within 5%, meaning that IPs are practical for measuring skin doses during IR. Moreover, the patient data can be stored online and easily called up when IR procedures must be repeated, helping to prevent radiation injuries. (authors)

  19. Implementation of repeat HIV testing during pregnancy in Kenya: a qualitative study.

    Science.gov (United States)

    Rogers, Anna Joy; Weke, Elly; Kwena, Zachary; Bukusi, Elizabeth A; Oyaro, Patrick; Cohen, Craig R; Turan, Janet M

    2016-07-11

    Repeat HIV testing in late pregnancy has the potential to decrease rates of mother-to-child transmission of HIV by identifying mothers who seroconvert after having tested negative for HIV in early pregnancy. Despite being national policy in Kenya, the available data suggest that implementation rates are low. We conducted 20 in-depth semi-structured interviews with healthcare providers and managers to explore barriers and enablers to implementation of repeat HIV testing guidelines for pregnant women. Participants were from the Nyanza region of Kenya and were purposively selected to provide variation in socio-demographics and job characteristics. Interview transcripts were coded and analyzed in Dedoose software using a thematic analysis approach. Four themes were identified a priori using Ferlie and Shortell's Framework for Change and additional themes were allowed to emerge from the data. Participants identified barriers and enablers at the client, provider, facility, and health system levels. Key barriers at the client level from the perspective of providers included late initial presentation to antenatal care and low proportions of women completing the recommended four antenatal visits. Barriers to offering repeat HIV testing for providers included heavy workloads, time limitations, and failing to remember to check for retest eligibility. At the facility level, inconsistent volume of clients and lack of space required for confidential HIV retesting were cited as barriers. Finally, at the health system level, there were challenges relating to the HIV test kit supply chain and the design of nationally standardized antenatal patient registers. Enablers to improving the implementation of repeat HIV testing included client dissemination of the benefits of antenatal care through word-of-mouth, provider cooperation and task shifting, and it was suggested that use of an electronic health record system could provide automatic reminders for retest eligibility. This study

  20. Biological effective dose studies in carcinoma of uterine cervix

    International Nuclear Information System (INIS)

    Yadav, Poonam; Ramasubramanian, V.

    2008-01-01

    Cancer of cervix is the second most common cancer worldwide among women. Several treatments related protocols of radiotherapy have been followed over few decades in its treatment for evaluating the response. These physical doses varying on the basics of fractionation size, dose rate and total dose needed to be indicated as biological effective dose (BED) to rationalize these treatments. The curative potential of radiation therapy in the management of carcinoma of the cervix is greatly enhanced by the use of intracavitary brachytherapy. Successful brachytherapy requires the high radiation dose to be delivered to the tumor where as minimum radiation dose reach to surrounding normal tissue. Present study is aimed to evaluate biologically effective dose in patients receiving high dose-rate brachytherapy plus external beam radiotherapy based on tumor cell proliferation values in cancer of the cervix patients. The study includes 30 patients' data as a retrospective analysis. In addition determine extent of a dose-response relationship existing between the biological effective dose at Point A and the bladder and rectum and the clinical outcomes

  1. Prognostic usefulness of repeated echocardiographic evaluation after acute myocardial infarction. TRACE Study Group. TRAndolapril Cardiac Evaluation

    DEFF Research Database (Denmark)

    Korup, E; Køber, L; Torp-Pedersen, C

    1999-01-01

    The prognostic value of repeated echocardiographic measurement of left ventricular function after acute myocardial infarction was evaluated. We found that repeated measurements of wall motion index in survivors of acute myocardial infarction, with no reinfarction, provide important prognostic...

  2. Studies on serum macro and micro minerals status in repeat breeder ...

    African Journals Online (AJOL)

    user01

    2014-03-05

    Mar 5, 2014 ... as well as 11.5% to gross domestic product. Repeat breeding is one of ... signs with no clinical detectable reproductive disorders. *Corresponding ... repeat breeding includes abnormal recommencement of postpartum ovarian ...

  3. Dose per unit area - a study of elicitation of nickel allergy

    DEFF Research Database (Denmark)

    Fischer, Louise Arup; Menné, Torkil; Johansen, Jeanne Duus

    2007-01-01

    BACKGROUND: Experimental sensitization depends upon the amount of allergen per unit skin area and is largely independent of the area size. OBJECTIVES: This study aimed at testing if this also applies for elicitation of nickel allergy. PATIENTS/METHODS: 20 nickel allergic individuals were tested...... with a patch test and a repeated open application test (ROAT). Nickel was applied on small and large areas. The varying parameters were area, total dose and dose per unit area. RESULTS: In the patch test, at a low concentration [15 microg nickel (microg Ni)/cm(2)], there were significantly higher scores...... on the large area with the same dose per area as the small area. At higher concentrations of nickel, no significant differences were found. In the ROAT at low concentration (6.64 microg Ni/cm(2)), it was found that the latency period until a reaction appeared was significantly shorter on the large area...

  4. Factors associated with repeated outbreak of anthrax in Bangladesh: qualitative and quantitative study

    Directory of Open Access Journals (Sweden)

    Jayedul Hassan

    2015-06-01

    Full Text Available Anthrax, caused by Bacillus anthracis is an acute, febrile disease of warm blooded animals including humans. Social norms and poverty in addition to climatic factors such as soil conditions, seasons of year, ambient temperature and rainfall influence the persistence of the B. anthracis and anthrax outbreaks. The present study was designed to reveal the factors influencing the repeated outbreak of anthrax in Bangladesh. Considering the previous outbreaks of anthrax, Sirajganj, Bogra, Kushtia, Tangail and Mymensingh districts of Bangladesh were selected for this study. To elucidate the factors, qualitative data relating to the animal management, knowledge and behavior of the people; and quantitative data relating to soil conditions, ambient temperature and rainfall were acquired, and analyzed critically. Based on the outbreak histories, a year was divided into two seasons, anthrax prone season (May-November and anthrax dry season (December-April. Anthrax spores could be isolated from 11.67% (n=14/120 of the soil samples collected from the study areas. The present study revealed that poor knowledge, lack of awareness, improper carcass disposal, inadequate vaccination, high Ca content and moisture in the soil along with high ambient temperature and rainfall during the anthrax prone season were the possible influencing factors of repeated outbreaks of anthrax in the study areas. Intensive propaganda to create public awareness of anthrax together with proper vaccination may reduce anthrax outbreaks in Bangladesh.

  5. Intradermal Inactivated Poliovirus Vaccine: A Preclinical Dose-Finding Study

    OpenAIRE

    Kouiavskaia, Diana; Mirochnitchenko, Olga; Dragunsky, Eugenia; Kochba, Efrat; Levin, Yotam; Troy, Stephanie; Chumakov, Konstantin

    2014-01-01

    Intradermal delivery of vaccines has been shown to result in dose sparing. We tested the ability of fractional doses of inactivated poliovirus vaccine (IPV) delivered intradermally to induce levels of serum poliovirus-neutralizing antibodies similar to immunization through the intramuscular route. Immunogenicity of fractional doses of IPV was studied by comparing intramuscular and intradermal immunization of Wistar rats using NanoPass MicronJet600 microneedles. Intradermal delivery of partial...

  6. A study of different dose calculation methods and the impact on the dose evaluation protocol in lung stereotactic radiation therapy

    International Nuclear Information System (INIS)

    Takada, Takahiro; Furuya, Tomohisa; Ozawa, Shuichi; Ito, Kana; Kurokawa, Chie; Karasawa, Kumiko; Miura, Kohei

    2008-01-01

    AAA (analytical anisotropic algorithm) dose calculation, which shows a better performance for heterogeneity correction, was tested for lung stereotactic radiation therapy (SBRT) in comparison to conventional PBC (pencil beam convolution method) to evaluate its impact on tumor dose parameters. Eleven lung SBRT patients who were treated with photon 4 MV beams in our department between April 2003 and February 2007 were reviewed. Clinical target volume (CTV) was delineated including the spicula region on planning CT images. Planning target volume (PTV) was defined by adding the internal target volume (ITV) and set-up margin (SM) of 5 mm from CTV, and then an multileaf collimator (MLC) penumbra margin of another 5 mm was also added. Six-port non-coplanar beams were employed, and a total prescribed dose of 48 Gy was defined at the isocenter point with four fractions. The entire treatment for an individual patient was completed within 8 days. Under the same prescribed dose, calculated dose distribution, dose volume histogram (DVH), and tumor dose parameters were compared between two dose calculation methods. In addition, the fractionated prescription dose was repeatedly scaled until the monitor units (MUs) calculated by AAA reached a level of MUs nearly identical to those achieved by PBC. AAA resulted in significantly less D95 (irradiation dose that included 95% volume of PTV) and minimal dose in PTV compared to PBC. After rescaling of each MU for each beam in the AAA plan, there was no revision of the isocenter of the prescribed dose required. However, when the PTV volume was less than 20 cc, a 4% lower prescription resulted in nearly identical MUs between AAA and PBC. The prescribed dose in AAA should be the same as that in PBC, if the dose is administered at the isocenter point. However, planners should compare DVHs and dose distributions between AAA and PBC for a small lung tumor with a PTV volume less than approximately 20 cc. (author)

  7. SU-F-T-329: Characteristic Study of a Rado-Photoluminescenct Glass Dosimeter with Accumulated Dose

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D; Chung, W; Chung, M [Kyung Hee University Hospital at Gangdong, Gangdong-gu (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

    2016-06-15

    Purpose: This study investigated the effect of accumulated dose on radiophotoluminescent glass dosimeter in megavoltage photon. Methods: 45 commercially-available radio-photoluminescence glass dosimeters (RPLGD; GD-302M, Asahi Techno Glass Co., Shizuoka, JAPAN) were irradiated to 10 × 10 cm{sup 2} open-field with 6, 10 and 15 MV photon beams at 100 cm of source to surface distance and dose maximum depths. Each energy has consists of five groups which is consists of three detectors. A group #1 and #2 was irradiated about 1 Gy to 100 Gy, and estimated the integral dose response with and without annealing procedure. A group #3 was read the dose after irradiated 10 Gy of dose by 10 times repeatedly to estimate the fading effect of RPLGD. A group #4 and #5 was produced same ways with different irradiation dose such as 50 Gy for group #4 and 100 Gy for group #5. Results: From the results of group #1 and #2, an annealed detector shows linear response to integral dose but other detectors without the annealing process, has supra linearity for integral dose especially close to 100 Gy dose. For group #3, #4 and #5, the dose response of repeated irradiation, the dose response was decreased about 15%, 12% and 7% for 6 MV, 10 MV and 15MV. Conclusion: It was found that RPLGD response to accumulated dose was supra linear and this respond was altered with amount of accumulated dose to the RPLGD. In addition, the fading effect need to be concern with RPLGD.

  8. Study of problems associated with the ultrasonic examination of repeatedly repaired austenitic stainless steel welds

    International Nuclear Information System (INIS)

    Subbaratnam, R.; Palaniappan, M.; Baskaran, A.; Chandramohan, R.

    1994-01-01

    In recent years the ultrasonic examination of austenitic stainless steel weldments has gained increased importance as an NDE technique for the volumetric examination in the nuclear power plant construction and other industries. A study has been undertaken to evaluate the effects of multiple repairs on austenitic stainless steel weldments, for the successful ultrasonic examination. The test welds have been subjected to repeated welding cycles and the ultrasonic parameters including the defect characterization have been evaluated for analysis. The paper discusses the approach followed, analysis, results obtained and the recommendations based on the above. 1 fig., 2 tabs

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  10. Dose-Escalation Study for Cardiac Radiosurgery in a Porcine Model

    Energy Technology Data Exchange (ETDEWEB)

    Blanck, Oliver, E-mail: oliver.blanck@uksh.de [Department of Radiation Oncology, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); CyberKnife Center Northern Germany, Guestrow (Germany); Bode, Frank [Medical Department II, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Gebhard, Maximilian [Institute of Pathology, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Hunold, Peter [Department of Radiology and Nuclear Medicine, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Brandt, Sebastian [Department of Anaesthesiology and Intensive Care Medicine, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Bruder, Ralf [Institute for Robotics and Cognitive Systems, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Grossherr, Martin [Department of Anaesthesiology and Intensive Care Medicine, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Vonthein, Reinhard [Institute of Medical Biometry and Statistics, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Rades, Dirk [Department of Radiation Oncology, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); Dunst, Juergen [Department of Radiation Oncology, University of Luebeck and University Medical Center Schleswig-Holstein, Campus Luebeck (Germany); University Copenhagen (Denmark)

    2014-07-01

    Purpose: To perform a proof-of-principle dose-escalation study to radiosurgically induce scarring in cardiac muscle tissue to block veno-atrial electrical connections at the pulmonary vein antrum, similar to catheter ablation. Methods and Materials: Nine mini-pigs underwent pretreatment magnetic resonance imaging (MRI) evaluation of heart function and electrophysiology assessment by catheter measurements in the right superior pulmonary vein (RSPV). Immediately after examination, radiosurgery with randomized single-fraction doses of 0 and 17.5-35 Gy in 2.5-Gy steps were delivered to the RSPV antrum (target volume 5-8 cm{sup 3}). MRI and electrophysiology were repeated 6 months after therapy, followed by histopathologic examination. Results: Transmural scarring of cardiac muscle tissue was noted with doses ≥32.5 Gy. However, complete circumferential scarring of the RSPV was not achieved. Logistic regressions showed that extent and intensity of fibrosis significantly increased with dose. The 50% effective dose for intense fibrosis was 31.3 Gy (odds ratio 2.47/Gy, P<.01). Heart function was not affected, as verified by MRI and electrocardiogram evaluation. Adjacent critical structures were not damaged, as verified by pathology, demonstrating the short-term safety of small-volume cardiac radiosurgery with doses up to 35 Gy. Conclusions: Radiosurgery with doses >32.5 Gy in the healthy pig heart can induce circumscribed scars at the RSPV antrum noninvasively, mimicking the effect of catheter ablation. In our study we established a significant dose-response relationship for cardiac radiosurgery. The long-term effects and toxicity of such high radiation doses need further investigation in the pursuit of cardiac radiosurgery for noninvasive treatment of atrial fibrillation.

  11. Intradermal inactivated poliovirus vaccine: a preclinical dose-finding study.

    Science.gov (United States)

    Kouiavskaia, Diana; Mirochnitchenko, Olga; Dragunsky, Eugenia; Kochba, Efrat; Levin, Yotam; Troy, Stephanie; Chumakov, Konstantin

    2015-05-01

    Intradermal delivery of vaccines has been shown to result in dose sparing. We tested the ability of fractional doses of inactivated poliovirus vaccine (IPV) delivered intradermally to induce levels of serum poliovirus-neutralizing antibodies similar to immunization through the intramuscular route. Immunogenicity of fractional doses of IPV was studied by comparing intramuscular and intradermal immunization of Wistar rats using NanoPass MicronJet600 microneedles. Intradermal delivery of partial vaccine doses induced antibodies at titers comparable to those after immunization with full human dose delivered intramuscularly. The results suggest that intradermal delivery of IPV may lead to dose-sparing effect and reduction of the vaccination cost. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  12. Study of teflon pads as high doses dosemeters

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  13. Estimation of dose and exposure at sentinel node study

    International Nuclear Information System (INIS)

    Skopljak, A.; Kucukalic-Selimovic, E.; Beslic, N.; Begic, A.; Begovic-Hadzimuratovic, S.; Drazeta, Z.; Beganovic, A.

    2005-01-01

    The purpose of this study was to estimate the dose end exposure in staff involved in sentinel node procedure for breast cancer patients. The Institute of Nuclear Medicine in Sarajevo uses a protocol for lymphoscintigraphy of the sentinel node whereby 13 MBq of 9 9mT c nanocoll are used. In this study, we measured radiation doses and exposure of a nuclear medicine physician and a technologist, as well as a surgeon performing sentinel node lymphoscintigraphy and biopsy. Dose and exposure were calculated using the equation in which we have gamma constant for 9 9mT c. Calculations were made for different times of exposure and distance. In Table 1. we estimated the dose and exposure during sentinel node study. Radiation levels were very low and the most exposed hospital staff performing sentinel node study were nuclear medicine physicians. The doses on the hands of surgeons were negligible 8 hours after exposure.(author)

  14. Potential Role of the Last Half Repeat in TAL Effectors Revealed by a Molecular Simulation Study

    Directory of Open Access Journals (Sweden)

    Hua Wan

    2016-01-01

    Full Text Available TAL effectors (TALEs contain a modular DNA-binding domain that is composed of tandem repeats. In all naturally occurring TALEs, the end of tandem repeats is invariantly a truncated half repeat. To investigate the potential role of the last half repeat in TALEs, we performed comparative molecular dynamics simulations for the crystal structure of DNA-bound TALE AvrBs3 lacking the last half repeat and its modeled structure having the last half repeat. The structural stability analysis indicates that the modeled system is more stable than the nonmodeled system. Based on the principle component analysis, it is found that the AvrBs3 increases its structural compactness in the presence of the last half repeat. The comparison of DNA groove parameters of the two systems implies that the last half repeat also causes the change of DNA major groove binding efficiency. The following calculation of hydrogen bond reveals that, by stabilizing the phosphate binding with DNA at the C-terminus, the last half repeat helps to adopt a compact conformation at the protein-DNA interface. It further mediates more contacts between TAL repeats and DNA nucleotide bases. Finally, we suggest that the last half repeat is required for the high-efficient recognition of DNA by TALE.

  15. Studies of absorbed dose determinations and spatial dose distributions for high energy proton beams

    International Nuclear Information System (INIS)

    Hiraoka, Takeshi

    1982-01-01

    Absolute dose determinations were made with three types of ionization chamber and a Faraday cup. Methane based tissue equivalent (TE) gas, nitrogen, carbon dioxide, air were used as an ionizing gas with flow rate of 10 ml per minute. Measurements were made at the entrance position of unmodulated beams and for a beam of a spread out Bragg peak at a depth of 17.3 mm in water. For both positions, the mean value of dose determined by the ionization chambers was 0.993 +- 0.014 cGy for which the value of TE gas was taken as unity. The agreement between the doses estimated by the ionization chambers and the Faraday cup was within 5%. Total uncertainty estimated in the ionization chamber and the Faraday cup determinations is 6 and 4%, respectively. Common sources of error in calculating the dose from ionization chamber measurements are depend on the factors of ion recombination, W value, and mass stopping power ratio. These factors were studied by both experimentally and theoretically. The observed values for the factors show a good agreement to the predicted one. Proton beam dosimetry intercomparison between Japan and the United States was held. Good agreement was obtained with standard deviation of 1.6%. The value of the TE calorimeter is close to the mean value of all. In the proton spot scanning system, lateral dose distributions at any depth for one spot beam can be simulated by the Gaussian distribution. From the Gaussian distributions and the central axis depth doses for one spot beam, it is easy to calculate isodose distributions in the desired field by superposition of dose distribution for one spot beam. Calculated and observed isodose curves were agreed within 1 mm at any dose levels. (J.P.N.)

  16. Validation of radiosterilization dose of human skin dressings for burnt treatment: preliminary study

    International Nuclear Information System (INIS)

    Castro, E.

    2008-01-01

    Full text: Due to the need for better materials to treat burnt patients, the Peruvian Institute of Nuclear Energy (IPEN) and the Rosa Guerzoni Chambergo Tissue Bank are collaborating for developing human skin dressings. Skin was procured from living donors, who surgically were performed a dermolipectomy. Exclusion criteria, stated by the Peruvian Organization for Transplant and Donation were observed. Glycerolized human skin dressings were processed at the tissue bank and sent to IPEN, where the gamma irradiation sterilizing dose was determined. The purpose of this work is to validate the radiation sterilization dose delivered to human skin dressings using the IAEA Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control. A batch of human skin dressings was tested. Average values of bioburden present in ten samples was 30 UFC/item, obtaining a sub-sterilization dose of 4 kGy. Irradiations were performed in the GammacellExcel 220. Sterility tests performed fulfilled the requirements established by the Code, achieving a validated dose value of 19.7 kGy. This preliminary study, that should be repeated in two other batches of processed human skin, allows to diminish 25 kGy the sterilizing dose to the stated above dose value, in a frame of a quality assurance system that also comprises the processes held at tissue banks previous irradiation. It also permit the availability of these materials in Peruvian hospitals. (Author)

  17. Psychological Processes and Repeat Suicidal Behavior: A Four-Year Prospective Study

    Science.gov (United States)

    2013-01-01

    Objective: Although suicidal behavior is a major public health concern, understanding of individually sensitive suicide risk mechanisms is limited. In this study, the authors investigated, for the first time, the utility of defeat and entrapment in predicting repeat suicidal behavior in a sample of suicide attempters. Method: Seventy patients hospitalized after a suicide attempt completed a range of clinical and psychological measures (depression, hopelessness, suicidal ideation, defeat, and entrapment) while in hospital. Four years later, a nationally linked database was used to determine who had been hospitalized again after a suicide attempt. Results: Over 4 years, 24.6% of linked participants were readmitted to hospital after a suicidal attempt. In univariate logistic regression analyses, defeat and entrapment as well as depression, hopelessness, past suicide attempts, and suicidal ideation all predicted suicidal behavior over this interval. However, in the multivariate analysis, entrapment and past frequency of suicide attempts were the only significant predictors of suicidal behavior. Conclusions: This longitudinal study supports the utility of a new theoretical model in the prediction of suicidal behavior. Individually sensitive suicide risk processes like entrapment could usefully be targeted in treatment interventions to reduce the risk of repeat suicidal behavior in those who have been previously hospitalized after a suicide attempt. PMID:23855989

  18. Study of genomic instability induced by low dose ionizing radiation

    International Nuclear Information System (INIS)

    Seoane, A.; Crudeli, C.; Dulout, F.

    2006-01-01

    The crews of commercial flights and services staff of radiology and radiotherapy from hospitals are exposed to low doses of ionizing radiation. Genomic instability includes those adverse effects observed in cells, several generations after the exposure occurred. The purpose of this study was to analyze the occurrence of genomic instability by very low doses of ionizing radiation [es

  19. Study of damage of graphite/epoxy composites submitted to repeated quasi-static shear loadings

    International Nuclear Information System (INIS)

    Khadhraoui-Lattreche, Malika

    1984-01-01

    Quasi static loading tests on composite materials with organic matrix allow the behaviour of the materials under repeated loadings to be studied while avoiding viscoelastic effects. In this research thesis, the author reports the study of one-directional composite samples submitted to static pure shear loadings which represent the most severe stress state for this type of material. The material behaviour has been determined by application of loads greater than the yield strength, and of zero torque unloads. This allowed cumulative residual deformations to be monitored, and the increasing evolution of this parameter to be studied with respect to the number of applied cycles. The author deduces from these results a characteristic law for the material which introduces a decoupling between the stress and the cumulative residual deformation. Thus, a method of prediction of cumulative residual deformations is developed. Besides, a brief application to another material seems to confirm this type of law, and suggests that its generalisation should be studied [fr

  20. Repeat Colonoscopy within 6 Months after Initial Outpatient Colonoscopy in Ontario: A Population-Based Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Lawrence Paszat

    2017-01-01

    Full Text Available Background. The goal of this study is to examine utilization of early repeat colonoscopy ≤ 6 months after an index procedure. Methods. We identified persons having repeat colonoscopy ≤ 6 months following outpatient colonoscopy without prior colonoscopy ≤ 5 years or prior diagnosis of colorectal cancer (CRC. We modeled repeat colonoscopy using a generalized estimating equation with an exchangeable correlation structure to account for clustering of patients by endoscopist. Results. The population included 334,663 persons, 7,892 (2.36% of whom had an early repeat colonoscopy within 6 months. Overall, endoscopist prior year colonoscopy volume was inversely related to repeat ≤ 6 months. Repeat colonoscopy ≤ 6 months varied by the clinical setting of the index colonoscopy (adjusted OR = 1.41 (95% CI 1.29–1.55 at nonhospital facilities compared to teaching or community hospitals. Among those who had polypectomy or biopsy, the adjusted OR for early repeat ≤ 6 months was elevated among those whose index colonoscopy was at a nonhospital facility (OR 1.44, 95% CI 1.30–1.60, compared to those at a teaching hospital or community hospital. Conclusions. Repeat colonoscopy ≤ 6 months after an index procedure is associated with the clinical setting of the index colonoscopy.

  1. Optimisation of CT procedures by dose reduction in abdominal-pelvic studies of chronic patients

    International Nuclear Information System (INIS)

    Calvo, D.; Rodriguez, A.M.; Peinado, M.A.; Fernandez, B.; Fernandez, B.M.; Jimenez, J.R.

    2006-01-01

    Full text of publication follows: Objectives: CT explorations are responsible of a significant increase of collective dose during last twenty years. However, by adapting the procedures to the specific diagnostic requirements of each kind of exploration, dose values can be decreased. This can be specially interesting for chronic patients who undergo several CT controls. The aim of this research is to contrast CT image diagnostic quality by comparing those techniques commonly used in our hospital with lower dose ones. Materials and methods: In a first phase, a study on phantom has been developed to evaluate image quality variations obtained with standard a several low dose techniques. Dose reduction was quantified as well by means of C.T.D.I. w measurements on an abdominal phantom. Both aspects were taken into account to determine a dose threshold below image quality degradation was considered unacceptable from a diagnostic point of view. Subsequently, a group of 50 chronic patients under follow -up was selected to undergo a control CT but with a low dose-technique. Image diagnostic quality was compared with that of previous controls obtained using the standard technique. Three experimented radiologist carried out this evaluation over a sample of six particular slices located at the abdomen and pelvis using an ordinal scale. Such a scale gradate the confidence level of the image for each radiologist. This evaluation was repeated one and two months later without knowledge of previous results to calculate inter and intra -observer variability. Conclusions: CT studies can be carried out with a significant dose reduction preserving their diagnostic capabilities. A quantitative evaluation will be offered at the end of the study, still running. (authors)

  2. A 14-day repeated-dose oral toxicological evaluation of an isothiocyanate-enriched hydro-alcoholic extract from Moringa oleifera Lam. seeds in rats.

    Science.gov (United States)

    Kim, Youjin; Jaja-Chimedza, Asha; Merrill, Daniel; Mendes, Odete; Raskin, Ilya

    2018-01-01

    A 14-d short-term oral toxicity study in rats evaluated the safety of moringa isothiocyanate-1 (MIC-1)-enriched hydro-alcoholic moringa seeds extract (MSE). Rats (5 males/5 females per group) were gavaged daily for 14 d with the vehicle control or MSE, at 78 (low), 257 (mid-low), 772 (mid-high), or 2571 (high) mg/kg bw/d, standardized to MIC-1 (30, 100, 300, or 1000 mg/kg bw/d, respectively). Toxicological endpoints included body weight and weight gain, food consumption and feed efficiency, clinical observations, hematology, gross necropsy and histopathology, and relative organ weights. Mortality was only observed in the high dose group animals, both male and female, representing decreases in body weight/weight gain and food consumption/feed efficiency. Irregular respiratory patterns and piloerection were major clinical observations found primarily in the mid-high and high dose group animals. In the high dose group, gastrointestinal distention and stomach discoloration were observed in non-surviving males and females, and degeneration and necrosis of the testicular germinal cells and epididymal cells were also observed in a non-surviving male. Increased liver weights were found in females in the mid-high and high dose groups. Animals in the low and mid-low groups did not exhibit adverse effects of MSE (100 mg/kg bw/d MIC-1). A no observed adverse effect level (NOAEL) of the standardized MSE was determined as 257 mg/kg bw/d providing 100 mg/kg bw/d MIC-1.

  3. Reasons of repeat dental treatment under general anaesthesia: A retrospective study.

    Science.gov (United States)

    Guidry, J; Bagher, S; Felemban, O; Rich, A; Loo, C

    2017-12-01

    The purpose of this chart review study was to investigate the common factors that exist in paediatric patients requiring a repeat dental treatment under general anaesthesia (GA2) within four years after the initial dental treatment under general anaesthesia (GA1). The Electronic Health Records of one to 12 year-old children who received dental treatment under general anaesthesia (GA) between April 2004 and October 2009 were identified and analysed by a single examiner. Children who had GA2, within a four year period following GA1 were categorised as cases. Children who had only one dental treatment under GA were considered the control pool. Each case was matched to three controls based on sex and age range at GA1 of ± 6 months. Other recorded variables included: date of birth, date of GAs (GA1 and GA2 for cases; GA1 for controls), type of payment, dmfs before GA1, dental treatments provided under GA, return of 1-week post-GA1 follow-up, frequency of recare/recall visits following one-year post-GA1 visit and the type and frequency of post GA1 emergency visits. Out of 581 subjects, 29 (4.99%) cases were matched to 87 controls. Medically compromised patients had four times the risk of GA2. At GA1, cases received statistically significant less sealants (p=0.026), less extractions (pdental treatment under general anaesthesia were more likely to have a repeat dental treatment under general anaesthesia within 4 years.

  4. Single molecule study of the intrinsically disordered FG-repeat nucleoporin 153.

    Science.gov (United States)

    Milles, Sigrid; Lemke, Edward A

    2011-10-05

    Nucleoporins (Nups), which are intrinsically disordered, form a selectivity filter inside the nuclear pore complex, taking a central role in the vital nucleocytoplasmic transport mechanism. These Nups display a complex and nonrandom amino-acid architecture of phenylalanine glycine (FG)-repeat clusters and intra-FG linkers. How such heterogeneous sequence composition relates to function and could give rise to a transport mechanism is still unclear. Here we describe a combined chemical biology and single-molecule fluorescence approach to study the large human Nup153 FG-domain. In order to obtain insights into the properties of this domain beyond the average behavior, we probed the end-to-end distance (R(E)) of several ∼50-residues long FG-repeat clusters in the context of the whole protein domain. Despite the sequence heterogeneity of these FG-clusters, we detected a reoccurring and consistent compaction from a relaxed coil behavior under denaturing conditions (R(E)/R(E,RC) = 0.99 ± 0.15 with R(E,RC) corresponding to ideal relaxed coil behavior) to a collapsed state under native conditions (R(E)/R(E,RC) = 0.79 ± 0.09). We then analyzed the properties of this protein on the supramolecular level, and determined that this human FG-domain was in fact able to form a hydrogel with physiological permeability barrier properties. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  5. Radiation doses to children during modified barium swallow studies

    International Nuclear Information System (INIS)

    Weir, Kelly A.; McMahon, Sandra M.; Long, Gillian; Bunch, Judith A.; Pandeya, Nirmala; Coakley, Kerry S.; Chang, Anne B.

    2007-01-01

    There are minimal data on radiation doses to infants and children undergoing a modified barium swallow (MBS) study. To document screening times, dose area product (DAP) and effective doses to children undergoing MBS and to determine factors associated with increased screening times and effective dose. Fluoroscopic data (screening time, DAP, kVp) for 90 consecutive MBS studies using pulse fluoroscopy were prospectively recorded; effective dose was calculated and data were analyzed for effects of behavior, number of swallow presentations, swallowing dysfunction and medical problems. Mean effective dose for the entire group was 0.0826 ± 0.0544 mSv, screening time 2.48 ± 0.81 min, and DAP 28.79 ± 41.72 cGy cm 2 . Significant differences were found across three age groups (≤1.0, >1.0-3.0 and >3.0 years) for effective dose (mean 0.1188, 0.0651 and 0.0529 mSv, respectively; P < 0.001), but not for screening time or DAP. Effective dose was correlated with screening time (P 0.007), DAP (P < 0.001), number of swallow presentations (P = 0.007), lower age (P = 0.017), female gender (P = 0.004), and height (P < 0.001). Screening time was correlated with total number of swallow presentations (P < 0.001) and DAP (P < 0.001). Screening times, DAP, effective dose, and child and procedural factors associated with higher effective doses are presented for children undergoing MBS studies. (orig.)

  6. Identifying the most successful dose (MSD) in dose-finding studies in cancer.

    Science.gov (United States)

    Zohar, Sarah; O'Quigley, John

    2006-01-01

    For a dose finding study in cancer, the most successful dose (MSD), among a group of available doses, is that dose at which the overall success rate is the highest. This rate is the product of the rate of seeing non-toxicities together with the rate of tumor response. A successful dose finding trial in this context is one where we manage to identify the MSD in an efficient manner. In practice we may also need to consider algorithms for identifying the MSD which can incorporate certain restrictions, the most common restriction maintaining the estimated toxicity rate alone below some maximum rate. In this case the MSD may correspond to a different level than that for the unconstrained MSD and, in providing a final recommendation, it is important to underline that it is subject to the given constraint. We work with the approach described in O'Quigley et al. [Biometrics 2001; 57(4):1018-1029]. The focus of that work was dose finding in HIV where both information on toxicity and efficacy were almost immediately available. Recent cancer studies are beginning to fall under this same heading where, as before, toxicity can be quickly evaluated and, in addition, we can rely on biological markers or other measures of tumor response. Mindful of the particular context of cancer, our purpose here is to consider the methodology developed by O'Quigley et al. and its practical implementation. We also carry out a study on the doubly under-parameterized model, developed by O'Quigley et al. but not

  7. Sodium phenylbutyrate in Huntington's disease: a dose-finding study.

    Science.gov (United States)

    Hogarth, Penelope; Lovrecic, Luca; Krainc, Dimitri

    2007-10-15

    Transcriptional dysregulation in Huntington's disease (HD) is mediated in part by aberrant patterns of histone acetylation. We performed a dose-finding study in human HD of sodium phenylbutyrate (SPB), a histone deacetylase inhibitor that ameliorates the HD phenotype in animal models. We used a dose-escalation/de-escalation design, using prespecified toxicity criteria and standard clinical and laboratory safety measures. The maximum tolerated dose was 15 g/day. At higher doses, toxicity included vomiting, lightheadedness, confusion, and gait instability. We saw no significant laboratory or electrocardiographic abnormalities. Gene expression changes in blood suggested an inverse dose-response. In conclusion, SPB at 12 to 15 g/day appears to be safe and well-tolerated in human HD. 2007 Movement Disorder Society

  8. Micro-dosing for early biokinetic studies in humans

    International Nuclear Information System (INIS)

    Stenstroem, K.; Sydoff, M.; Mattsson, S.

    2010-01-01

    Micro-dosing is a new concept in drug development that-if implemented in the pharmaceutical industry-would mean that new drugs can be tested earlier in humans than done today. The human micro-dosing concept-or 'Phase 0'-may offer improved candidate selection, reduced failure rates in the drug development line and a reduction in the use of laboratory animals in early drug development, factors which will help to speed up drug development and also reduce the costs. Micro-dosing utilises sub-pharmacological amounts of the substance to open opportunities for early studies in man. Three technologies are used for micro-dosing: accelerator mass spectrometry (AMS), positron emission tomography and liquid chromatography-tandem mass spectrometry. This paper focuses on the principle of AMS and discusses the current status of micro-dosing with AMS. (authors)

  9. Topics on study of low dose-effect relationship

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-09-01

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

  10. Dose response study of PVA-Fx gel for three dimensional dose distribution

    International Nuclear Information System (INIS)

    Brindha, S.; Ayyangar, Komanduri M.; Shen, Bin; Saw, Cheng B.

    2001-01-01

    Modern radiotherapy techniques involve complex field arrangements using conformal and intensity modulated radiation that requires three dimensional treatment planning. The verification of these plans poses even more challenge. In 1984, Gore et al., proposed that ferrous gel dosimeters combined with magnetic resonance imaging (MRI) could be used to measure three dimensional radiation dose distributions. Since then, there has been much interest in the development of gel dosimetry to aid the determination of three dimensional dose distributions during field arrangements. In this work, preparation and study of the MR characteristics of a PVA-Fx gel reported in the literature is presented

  11. Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments.

    Science.gov (United States)

    Stambaugh, Cassandra; Nelms, Benjamin E; Dilling, Thomas; Stevens, Craig; Latifi, Kujtim; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2013-09-01

    The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for volumetric modulated arc therapy (VMAT), particularly in application to hypofractionated regimens. Also, no experimental study has provided full four-dimensional (4D) dose reconstruction in this scenario. The authors demonstrate how a recently described motion perturbation method, with full 4D dose reconstruction, is applied to describe the gradient and interplay effects during VMAT lung SBRT treatments. VMAT dose delivered to a moving target in a patient can be reconstructed by applying perturbations to the treatment planning system-calculated static 3D dose. Ten SBRT patients treated with 6 MV VMAT beams in five fractions were selected. The target motion (motion kernel) was approximated by 3D rigid body translation, with the tumor centroids defined on the ten phases of the 4DCT. The motion was assumed to be periodic, with the period T being an average from the empirical 4DCT respiratory trace. The real observed tumor motion (total displacement ≤ 8 mm) was evaluated first. Then, the motion range was artificially increased to 2 or 3 cm. Finally, T was increased to 60 s. While not realistic, making T comparable to the delivery time elucidates if the interplay effect can be observed. For a single fraction, the authors quantified the interplay effect as the maximum difference in the target dosimetric indices, most importantly the near-minimum dose (D99%), between all possible starting phases. For the three- and five-fractions, statistical simulations were performed when substantial interplay was found. For the motion amplitudes and periods obtained from the 4DCT, the interplay effect

  12. Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments

    International Nuclear Information System (INIS)

    Stambaugh, Cassandra; Nelms, Benjamin E.; Dilling, Thomas; Stevens, Craig; Latifi, Kujtim; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir

    2013-01-01

    Purpose: The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for volumetric modulated arc therapy (VMAT), particularly in application to hypofractionated regimens. Also, no experimental study has provided full four-dimensional (4D) dose reconstruction in this scenario. The authors demonstrate how a recently described motion perturbation method, with full 4D dose reconstruction, is applied to describe the gradient and interplay effects during VMAT lung SBRT treatments.Methods: VMAT dose delivered to a moving target in a patient can be reconstructed by applying perturbations to the treatment planning system-calculated static 3D dose. Ten SBRT patients treated with 6 MV VMAT beams in five fractions were selected. The target motion (motion kernel) was approximated by 3D rigid body translation, with the tumor centroids defined on the ten phases of the 4DCT. The motion was assumed to be periodic, with the period T being an average from the empirical 4DCT respiratory trace. The real observed tumor motion (total displacement ≤8 mm) was evaluated first. Then, the motion range was artificially increased to 2 or 3 cm. Finally, T was increased to 60 s. While not realistic, making T comparable to the delivery time elucidates if the interplay effect can be observed. For a single fraction, the authors quantified the interplay effect as the maximum difference in the target dosimetric indices, most importantly the near-minimum dose (D 99% ), between all possible starting phases. For the three- and five-fractions, statistical simulations were performed when substantial interplay was found.Results: For the motion amplitudes and periods obtained from the

  13. Study of absorbed dose distribution to high energy electron beams

    International Nuclear Information System (INIS)

    Cecatti, E.R.

    1983-01-01

    The depth absorbed dose distribution by electron beams was studied. The influence of the beam energy, the energy spread, field size and design characteristics of the accelerator was relieved. Three accelerators with different scattering and collimation systems were studied leading todifferent depth dose distributions. A theoretical model was constructed in order to explain the increase in the depth dose in the build-up region with the increase of the energy. The model utilizes a three-dimensional formalism based on the Fermi-Eyges multiple scattering theory, with the introduction of modifications that takes into account the criation of secondary electrons. (Author) [pt

  14. Dose response of rat retinal microvessels to proton dose schedules used clinically: a pilot study

    International Nuclear Information System (INIS)

    Archambeau, John O.; Mao, Xiao W.; McMillan, Paul J.; Gouloumet, Vanessa L.; Oeinck, Steven C.; Grove, Roger; Yonemoto, Leslie T.; Slater, Jerry D.; Slater, James M.

    2000-01-01

    Purpose: This preclinical rat pilot study quantifies retinal microvessel, endothelial, and pericyte population changes produced by proton irradiation Methods and Materials: The left eyes of rats were irradiated with single doses of 8, 14, 20, and 28 Gy protons; right eyes, with two fractions. Animals were euthanized, and eyes were removed; elastase digests were prepared, and cell populations were counted in sample fields. Results were compared with unirradiated controls. Results: Progressive time- and dose-dependent endothelial cell loss occurred following all schedules. Cell loss was significantly different from control values (p 0 phase of the mitotic cycle. 28 Gy produced photoreceptor cell loss. Conclusion: The retinal digest is an elegant bioassay to quantify the microvessel population response. Single- and split-dose schedules appear to yield similar outcomes, in terms of endothelial cell density

  15. A thermoluminescence study of mineral silicates extracted from herbs in the dose range 0.5–5 Gy

    International Nuclear Information System (INIS)

    Della Monaca, Sara; Fattibene, Paola; Bortolin, Emanuela

    2013-01-01

    The presence of silicates in many personal objects suggests their potential use at low dose as fortuitous dosimeter in an accidental radiological exposure, when conventional dosimetry is not available. The goal of the present work is the dosimetric characterization of mineral silicates extracted from the plant Hibiscus Sabdariffa L, known as Jamaica flower, in the dose range 0.5–5 Gy. By studying the radiation-induced signal in time, the temperature integration region between 210 °C and 250 °C was found to be the most stable and also reduced the effects of thermal fading in the dose reconstruction process; the dose response curve was linear between 0.5 Gy and 5 Gy. By checking the change in sensitivity after repeated exposures to ionizing radiations and to high temperature heating, no variation in the glow curve shape or peak intensities were detected. To eliminate a pre-existing background signal, all the characterization measurements were performed with aliquots “annealed” by a preliminary readout of the TL. - Highlights: • Glow curves change in shape and intensity just in the first 3 days after irradiation. • The dose response is linear in the dose range 0.5–5 Gy. • The curve shape or intensity don't change after repeated exposures and heatings. • Encouraging results were obtained in the dose recovery test

  16. An effective dose of ketamine for eliminating pain during injection of propofol: a dose response study.

    Science.gov (United States)

    Wang, M; Wang, Q; Yu, Y Y; Wang, W S

    2013-09-01

    Ketamine can completely eliminate pain associated with propofol injection. However, the effective dose of ketamine to eliminate propofol injection pain has not been determined. The purpose of this study was to determine the effective dose of ketamine needed to eliminate pain in 50% and 95% of patients (ED50 and ED95, respectively) during propofol injections. This study was conducted in a double-blinded fashion and included 50 patients scheduled for elective gynecological laparoscopy under general anesthesia. The initial dose of ketamine used in the first patient was 0.25mg/kg. The dosing modifications were in increments or decrements of 0.025 mg/kg. Ketamine was administered 15 seconds before injecting propofol (2.5mg/kg), which was injected at a rate of 1mL/s. Patients were asked to rate their pain during propofol injection every 5s econds using a 0-3 pain scale. The highest pain score was recorded. The ED50, ED95 and 95% confidence intervals (CI) were determined by probit analyses. The dose of ketamine ranged from 0.175 to 0.275 mg/kg. The ED50 and ED95 of ketamine for eliminating pain during propofol injection were 0.227 mg/kg and 0.283 mg/kg, respectively (95%CI: 0.211-0.243 mg/kg and 0.26-0.364 mg/kg, respectively). Ketamine at an approximate dose of 0.3mg/kg was effective in eliminating pain during propofol injection. Copyright © 2013 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  17. Dose profile study in head CT scans using radiochromic films

    Energy Technology Data Exchange (ETDEWEB)

    Ladino G, A. M.; Prata M, A., E-mail: amlgphys@gmail.com [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  18. Dose profile study in head CT scans using radiochromic films

    International Nuclear Information System (INIS)

    Ladino G, A. M.; Prata M, A.

    2016-10-01

    Diagnostic images of computed tomography generate higher doses than other methods of diagnostic radiology using X-ray beam attenuation. Clinical applications of CT have been increased by technological advances, what leads to a wide variety of scanner in the Brazilian technological pool. It has been difficult to implement dose reduction strategies because of the lack of proper guidance on computed tomography examinations. However, CT scanners allow adjusting acquisition parameter according to the patients physical profile and diagnostic application for which the scan is intended. The knowledge of the dose distribution is important because changes in image acquisition parameters may provide dose reduction. In this study, it was used a cylindrical head phantom in PMMA with 5 openings, what allows dose measurement in 5 regions. In a GE CT scanner, Discovery model of 64 channels, the central slice of the head phantom was irradiated and the absorbed doses were measured using a pencil ionization chamber. Radiochromic film strips were placed in the peripheral and in the central region of the head phantom and was performed a scan of 10 cm in the phantom central region. The scan was performed using the head scanning protocol of the radiobiology service, with a voltage of 120 kV. After scanning, the radiochromic film strips were digitalized and their digital images were used to have the dose longitudinal profiles. The dose values recorded have variation in a range of 18.66 to 23.57 mGy. In the results it was compared the dose index values obtained by the pencil chamber measurement to the dose longitudinal profiles recorded by the film strips. (Author)

  19. Discrepancies in autobiographical memories— implications for the assessment of asylum seekers: repeated interviews study

    Science.gov (United States)

    Herlihy, Jane; Scragg, Peter; Turner, Stuart

    2002-01-01

    Objective To investigate the consistency of autobiographical memory of people seeking asylum, in light of the assumption that discrepancies in asylum seekers' accounts of persecution mean that they are fabricating their stories. Design Repeated interviews. Setting England, 1999 and 2000. Participants Community sample of 27 Kosovan and 12 Bosnian refugees. Main outcome measures Discrepancies in repeated descriptions of one traumatic and one non-traumatic event, including specific details, rated as central or peripheral to the event. Self report measures of post-traumatic stress disorder and depression. Results Discrepancies between an individual's accounts were common. For participants with high levels of post-traumatic stress, the number of discrepancies increased with length of time between interviews. More discrepancies occurred in details peripheral to the account than in details that were central to the account. Conclusion The assumption that inconsistency of recall means that accounts have poor credibility is questionable. Discrepancies are likely to occur in repeated interviews. For refugees showing symptoms of high levels of post-traumatic stress, the length of the application process may also affect the number of discrepancies. Recall of details rated by the interviewee as peripheral to the account is more likely to be inconsistent than recall of details that are central to the account. Thus, such inconsistencies should not be relied on as indicating a lack of credibility. What is already known on this topicDiscrepancies between accounts of an event are often used to judge the credibility of asylum seekersWhat this study addsDiscrepancies arise between two accounts of the same event even when there is no reason for fabricationRefugees with high levels of post-traumatic stress are more likely to give inconsistent accounts if they have a long time to wait between interviewsInterviewees are more likely to be inconsistent in details that they rate as peripheral

  20. SU-E-J-263: Repeatability of SUV and Texture Parameters in Serial PET Studies

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, J; Humm, J; Nehmeh, S; Schoder, H [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2015-06-15

    Purpose: Standardized uptake values (SUV) are standard quantitative PET measures of FDG tumor uptake used,and are used as a tool to monitor response to therapy. Textural analysis is emerging as a new tool for assessing intratumoral heterogeneity which may allow better tissue characterization and improved prediction of response and survival rate.Understanding what variations may be expected in these parameters is key in order to make decisions based on how the change throughout the course of treatment. The aim of this study was to assess repeatability in SUV measures and texture parameters,and establish criteria that differentiate changes associated with treatment rather than statistical variability. Methods: Eighty patients,167 random lesions total,were scanned in a GE Discovery STE PET/CT Scanner. One field-of-view was chosen centered on the largest lesion observed in a clinical whole-body FDG PET.Immediately following,a gated 9 min scan was acquired in list mode,without changing the patient’s position between any scans. Data was replayed into 3 time bins,3 min each,in order to insure equivalent noise characteristics in each replicate.Data was reconstructed into 128×128×47 square matrices.One VOI was drawn over each lesion for each patient and used to segment all 3 replicates. The mean.max and peak SUV were calculated for each VOI and replicate. First-order textural features were also calculated (skewness and kurtosis). Repeatability was calculated as the average standard deviation over the mean for the 3 repeated measurements for each lesion. Results: The average percent error in the SUV max,peak and mean were 3.4%(0– 12.9%),1.9% (0–7.5%),2.8% (0–12.2%),respectively.For skewness and kurtosis they were 10.9% and 17.8%. Conclusion: We have shown that there is a large variation in %error in SUV measures across patients. SUVpeak is the least variable and kurtosis and skewness parameters are less reliable thatn SUVs.Higher order textures are be.

  1. SU-E-J-263: Repeatability of SUV and Texture Parameters in Serial PET Studies

    International Nuclear Information System (INIS)

    Schwartz, J; Humm, J; Nehmeh, S; Schoder, H

    2015-01-01

    Purpose: Standardized uptake values (SUV) are standard quantitative PET measures of FDG tumor uptake used,and are used as a tool to monitor response to therapy. Textural analysis is emerging as a new tool for assessing intratumoral heterogeneity which may allow better tissue characterization and improved prediction of response and survival rate.Understanding what variations may be expected in these parameters is key in order to make decisions based on how the change throughout the course of treatment. The aim of this study was to assess repeatability in SUV measures and texture parameters,and establish criteria that differentiate changes associated with treatment rather than statistical variability. Methods: Eighty patients,167 random lesions total,were scanned in a GE Discovery STE PET/CT Scanner. One field-of-view was chosen centered on the largest lesion observed in a clinical whole-body FDG PET.Immediately following,a gated 9 min scan was acquired in list mode,without changing the patient’s position between any scans. Data was replayed into 3 time bins,3 min each,in order to insure equivalent noise characteristics in each replicate.Data was reconstructed into 128×128×47 square matrices.One VOI was drawn over each lesion for each patient and used to segment all 3 replicates. The mean.max and peak SUV were calculated for each VOI and replicate. First-order textural features were also calculated (skewness and kurtosis). Repeatability was calculated as the average standard deviation over the mean for the 3 repeated measurements for each lesion. Results: The average percent error in the SUV max,peak and mean were 3.4%(0– 12.9%),1.9% (0–7.5%),2.8% (0–12.2%),respectively.For skewness and kurtosis they were 10.9% and 17.8%. Conclusion: We have shown that there is a large variation in %error in SUV measures across patients. SUVpeak is the least variable and kurtosis and skewness parameters are less reliable thatn SUVs.Higher order textures are be

  2. Study of the Radiochromic Film for High Dose Measurement in Radiation Processing

    Directory of Open Access Journals (Sweden)

    CHEN Yi-zhen

    2016-02-01

    Full Text Available To establish the radiochromic film dosimeter for high dose level measurement during radiation processing, By corresponding formula and its preparation process research, batches of radiochromic film dosimeters were prepared using nylon as substrate and pararosaniline cyanide as dye. In Co-60 gamma reference radiation field, dosimetry response performance of radiochromic film was studied and results showed that the repeatability was good to 1.0%. The response curves demonstrated good linearity in the dose range of 5-210 kGy, and the signal of radiochromic film dosimeters after irradiation under the condition of low temperature storage within 2 weeks was stable. In addition, the radiochromic film dosimeters were not found to have noticeable dose rate dependence in the range of this experiment. In the linear dose range, radiochromic film dosimeter measures the absorbed dose, with extended uncertainty 4.2% (k=2 for Co-60 gamma rays. The film was suitable as dosimeters for the parameters measurement of the electron beam on the accelerator.

  3. Neural Plasticity Associated with Hippocampal PKA-CREB and NMDA Signaling Is Involved in the Antidepressant Effect of Repeated Low Dose of Yueju Pill on Chronic Mouse Model of Learned Helplessness

    Directory of Open Access Journals (Sweden)

    Zhilu Zou

    2017-01-01

    Full Text Available Yueju pill is a traditional Chinese medicine formulated to treat syndromes of mood disorders. Here, we investigated the therapeutic effect of repeated low dose of Yueju in the animal model mimicking clinical long-term depression condition and the role of neural plasticity associated with PKA- (protein kinase A- CREB (cAMP response element binding protein and NMDA (N-methyl-D-aspartate signaling. We showed that a single low dose of Yueju demonstrated antidepressant effects in tests of tail suspension, forced swim, and novelty-suppressed feeding. A chronic learned helplessness (LH protocol resulted in a long-term depressive-like condition. Repeated administration of Yueju following chronic LH remarkably alleviated all of depressive-like symptoms measured, whereas conventional antidepressant fluoxetine only showed a minor improvement. In the hippocampus, Yueju and fluoxetine both normalized brain-derived neurotrophic factor (BDNF and PKA level. Only Yueju, not fluoxetine, rescued the deficits in CREB signaling. The chronic LH upregulated the expression of NMDA receptor subunits NR1, NR2A, and NR2B, which were all attenuated by Yueju. Furthermore, intracerebraventricular administration of NMDA blunted the antidepressant effect of Yueju. These findings supported the antidepressant efficacy of repeated routine low dose of Yueju in a long-term depression model and the critical role of CREB and NMDA signaling.

  4. Neural Plasticity Associated with Hippocampal PKA-CREB and NMDA Signaling Is Involved in the Antidepressant Effect of Repeated Low Dose of Yueju Pill on Chronic Mouse Model of Learned Helplessness.

    Science.gov (United States)

    Zou, Zhilu; Chen, Yin; Shen, Qinqin; Guo, Xiaoyan; Zhang, Yuxuan; Chen, Gang

    2017-01-01

    Yueju pill is a traditional Chinese medicine formulated to treat syndromes of mood disorders. Here, we investigated the therapeutic effect of repeated low dose of Yueju in the animal model mimicking clinical long-term depression condition and the role of neural plasticity associated with PKA- (protein kinase A-) CREB (cAMP response element binding protein) and NMDA (N-methyl-D-aspartate) signaling. We showed that a single low dose of Yueju demonstrated antidepressant effects in tests of tail suspension, forced swim, and novelty-suppressed feeding. A chronic learned helplessness (LH) protocol resulted in a long-term depressive-like condition. Repeated administration of Yueju following chronic LH remarkably alleviated all of depressive-like symptoms measured, whereas conventional antidepressant fluoxetine only showed a minor improvement. In the hippocampus, Yueju and fluoxetine both normalized brain-derived neurotrophic factor (BDNF) and PKA level. Only Yueju, not fluoxetine, rescued the deficits in CREB signaling. The chronic LH upregulated the expression of NMDA receptor subunits NR1, NR2A, and NR2B, which were all attenuated by Yueju. Furthermore, intracerebraventricular administration of NMDA blunted the antidepressant effect of Yueju. These findings supported the antidepressant efficacy of repeated routine low dose of Yueju in a long-term depression model and the critical role of CREB and NMDA signaling.

  5. Field study to evaluate radiation doses in dental practices

    International Nuclear Information System (INIS)

    Panzer, W.; Scheurer, C.

    1984-05-01

    An inexpensive and simple test device was developed and used in a field study to evaluate entrance dose, dose to an intra-oral film, filtration and field size under routine conditions in more than 150 dental practices. The test device consists of two films of different speed and a set of 5 thin copper filters for a filter analytical determination of the radiation quality. Dentists voluntarily participating in the study were asked to expose the test device like they usually do when examining a molar tooth. The main result was the evidence of a significant dose reduction compared to the findings of similar studies performed in 1970 and 1976. This reduction is due to a general shift to lower values and a complete disappearance of values above 45 mGy (5 R) which in 1970 were still more than 15%. In the same way the number of facilities showing insufficient filtration or collimation had decreased. Nevertheless, a large spread of dose values could still be observed, ranging from less than 0.45 mGy (50 mR) to more than 26 mGy (3 R), for the entrance dose. The most striking result, however, was that such an important parameter like the speed of the films used at the respective unit turned out to have no impact on the entrance dose. (orig./HP)

  6. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    evaluating the deployment repeatability builds upon the testing or analysis of deployment kinematics (Chapter 6) and adds repetition. Introduction...material yield or failure during a test. For the purposes of this chapter, zero shift will refer to permanent changes in the structure, while reversible ...the content of other chapters in this book: Gravity Compensation (Chapter 4) and Deployment Kinematics and Dynamics (Chapter 6). Repeating the

  7. Is Forced Swimming Immobility a Good Endpoint for Modeling Negative Symptoms of Schizophrenia? - Study of Sub-Anesthetic Ketamine Repeated Administration Effects

    Directory of Open Access Journals (Sweden)

    GILDA NEVES

    2017-08-01

    Full Text Available ABSTRACT Immobility time in the forced swimming has been described as analogous to emotional blunting or apathy and has been used for characterizing schizophrenia animal models. Several clinical studies support the use of NMDA receptor antagonists to model schizophrenia in rodents. Some works describe the effects of ketamine on immobility behavior but there is variability in the experimental design used leading to controversial results. In this study, we evaluated the effects of repeated administration of ketamine sub-anesthetic doses in forced swimming, locomotion in response to novelty and novel object recognition, aiming a broader evaluation of the usefulness of this experimental approach for modeling schizophrenia in mice. Ketamine (30 mg/kg/day i.p. for 14 days induced a not persistent decrease in immobility time, detected 24h but not 72h after treatment. This same administration protocol induced a deficit in novel object recognition. No change was observed in mice locomotion. Our results confirm that repeated administration of sub-anesthetic doses of ketamine is useful in modeling schizophrenia-related behavioral changes in mice. However, the immobility time during forced swimming does not seem to be a good endpoint to evaluate the modeling of negative symptoms in NMDAR antagonist animal models of schizophrenia.

  8. Is Forced Swimming Immobility a Good Endpoint for Modeling Negative Symptoms of Schizophrenia? - Study of Sub-Anesthetic Ketamine Repeated Administration Effects.

    Science.gov (United States)

    Neves, Gilda; Borsoi, Milene; Antonio, Camila B; Pranke, Mariana A; Betti, Andresa H; Rates, Stela M K

    2017-01-01

    Immobility time in the forced swimming has been described as analogous to emotional blunting or apathy and has been used for characterizing schizophrenia animal models. Several clinical studies support the use of NMDA receptor antagonists to model schizophrenia in rodents. Some works describe the effects of ketamine on immobility behavior but there is variability in the experimental design used leading to controversial results. In this study, we evaluated the effects of repeated administration of ketamine sub-anesthetic doses in forced swimming, locomotion in response to novelty and novel object recognition, aiming a broader evaluation of the usefulness of this experimental approach for modeling schizophrenia in mice. Ketamine (30 mg/kg/day i.p. for 14 days) induced a not persistent decrease in immobility time, detected 24h but not 72h after treatment. This same administration protocol induced a deficit in novel object recognition. No change was observed in mice locomotion. Our results confirm that repeated administration of sub-anesthetic doses of ketamine is useful in modeling schizophrenia-related behavioral changes in mice. However, the immobility time during forced swimming does not seem to be a good endpoint to evaluate the modeling of negative symptoms in NMDAR antagonist animal models of schizophrenia.

  9. Dose finding study of granisetron in patients receiving high-dose cisplatin chemotherapy. The Granisetron Study Group.

    Science.gov (United States)

    Riviere, A.

    1994-01-01

    The efficacy and safety of three different doses of granisetron (2 micrograms kg-1, group A; 10 micrograms kg-1, group B; 40 micrograms kg-1, group C) were compared in a randomised, double-blind study of 157 patients due to receive high-dose cisplatin therapy (mean dose > 97 mg m-2). In each group, up to two 3 mg rescue doses of granisetron were allowed if more than mild nausea or vomiting occurred. In group A 30.8%, in group B 61.5% and in group C 67.9% of patients were complete responders (i.e. no vomiting or nothing worse than mild nausea) during the first 24 h. These differences are significant between groups A and B, and A and C. There were no statistically significant differences in any efficacy variable between the 10 micrograms kg-1 and 40 micrograms kg-1 groups, although in each case the trend favoured the higher dose. Additional rescue doses resulted in resolved or improved symptoms in 95.3% for the first rescue dose and 93.3% for the second. Over the 7 days of the study, 82.7%, 82.7% and 86.8% of patients in groups A, B and C respectively were treated with granisetron alone. Headache was the most common side-effect, reported by 9.6% of patients; the majority of headaches were mild. There was no difference between the treatment groups regarding the adverse event rate. We concluded that prophylactic doses of 10 or 40 micrograms kg-1 lead to a safe and satisfactory degree of control of nausea and vomiting induced by high-dose cisplatin. PMID:8180032

  10. Occupational dose measurement in interventional cardiology, dosimetry comparison study

    International Nuclear Information System (INIS)

    Ahmad, A.M.A.

    2008-05-01

    The number of cardiology interventional procedures has significantly increased recently. This is due to the reliability of the diagnostic equipment to diagnose many heart disease. In the procedures the x-ray used results in increasing radiation doses to the staff. The cardiologists and other staff members in interventional cardiology are usually working close to the area under examination and receive the dose primarily from scattered radiation from the patient. Therefore workers in interventional cardiology are expected to receive high doses. This study overviews the status of occupational exposure at the three cardiology centers at three different hospitals in Khartoum compared with that received by workers at other medical practices (radiotherapy, nuclear medicine and diagnostic radiology) in the Institute of Nuclear and Technology (INMO) at El Gezira. The TLD Harshaw 6600 reader was used in the assessment of effective dose for Hp (10). Two TLDs were used by each worker at the three cardiology centres, one worn under a protective apron and the other worn outside and above the apron as specified by the ICRP. Each worker at the other sections was facilitated with one dosimeter to be worn on the chest. The annual doses received by 14 cardiologists, 13 nurses and 9 technologists at the three cardiology centres were in the range: (0.84-4.77), (0.15-2.08), (0.32-1.10) mSv respectively. In the INMO the annual doses received by 7 doctors, 5 nurses and 14 technologists were in the range: (0.12-0.51), (0.11-0.65), (0.03-1.39) mSv respectively. The results showed that the annual doses received by the workers do not exceed 20 mSv. The study also indicated that doses received by workers in interventional cardiology, in particular the cardiologists are high compared to that received at the other medical sections.(Author)

  11. Thermal stability of chicken brain {alpha}-spectrin repeat 17: a spectroscopic study

    Energy Technology Data Exchange (ETDEWEB)

    Brenner, Annette K. [University of Bergen, Department of Chemistry (Norway); Kieffer, Bruno [Ecole Superieure de Biotechnologie de Strasbourg, IGBMC Biomolecular NMR Group, CNRS UMR 7104 (France); Trave, Gilles [Ecole Superieure de Biotechnologie de Strasbourg, Equipe Oncoproteines, IREBS, UMR 7242 (France); Froystein, Nils Age [University of Bergen, Department of Chemistry (Norway); Raae, Arnt J., E-mail: arnt.raae@mbi.uib.no [University of Bergen, Department of Molecular Biology (Norway)

    2012-06-15

    Spectrin is a rod-like multi-modular protein that is mainly composed of triple-helical repeats. These repeats show very similar 3D-structures but variable conformational and thermodynamical stabilities, which may be of great importance for the flexibility and dynamic behaviour of spectrin in the cell. For instance, repeat 17 (R17) of the chicken brain spectrin {alpha}-chain is four times less stable than neighbouring repeat 16 (R16) in terms of Increment G. The structure of spectrin repeats has mainly been investigated by X-ray crystallography, but the structures of a few repeats, e.g. R16, have also been determined by NMR spectroscopy. Here, we undertook a detailed characterization of the neighbouring R17 by NMR spectroscopy. We assigned most backbone resonances and observed NOE restraints, relaxation values and coupling constants that all indicated that the fold of R17 is highly similar to that of R16, in agreement with previous X-ray analysis of a tandem repeat of the two domains. However, {sup 15}N heteronuclear NMR spectra measured at different temperatures revealed particular features of the R17 domain that might contribute to its lower stability. Conformational exchange appeared to alter the linker connecting R17 to R16 as well as the BC-loop in close proximity. In addition, heat-induced splitting was observed for backbone resonances of a few spatially related residues including V99 of helix C, which in R16 is replaced by the larger hydrophobic tryptophan residue that is relatively conserved among other spectrin repeats. These data support the view that the substitution of tryptophan by valine at this position may contribute to the lower stability of R17.

  12. Mouse-specific antibody responses to a monoclonal antibody during repeated immunoscintigraphy investigations: Comparison of antibody titres and imaging studies in a rat model

    International Nuclear Information System (INIS)

    Pimm, M.V.; Gribben, S.J.; Markham, A.J.; Perkins, A.C.

    1990-01-01

    As a model for human mouse-specific antibody responses in patients undergoing immunoscintigraphy, we have investigated in rats the production of mouse-specific antibodies (MA) to the mouse monoclonal antibody 791T/36. At intervals of between 5 and 16 weeks the rats were given repeated cycles of intravenous (IV) injections of antibody with or without a simultaneous intradermal (ID) injection. The IV dose was 60 μg/kg, a dose similar to that used in many clinical immunoscintigraphy studies. The ID injection was 2 μg, which mimicks the skin test dose often given in clinical imaging protocols. The study was carried out with both 131 I-labelled antibody and with antibody labelled with 111 In by DTPA chelation. MA was measured with a passive haemagglutination assay using sheep red blood cells coated with the monoclonal antibody. Of rats given ID injections of unlabelled antibody at the same time as the IV imaging doses, 9/20 produced MA during 4 cycles of injections. In contrast, only 2/16 rats given only the IV dose produced MA. Both 131 I- and 111 In-labelled antibody appeared equally immunogenic with 5/18 and 6/18 overall responders, respectively. The production of MA was associated with a significant perturbation in the biodistribution of the IV dose of labelled antibody as seen by gamma-camera imaging of the rats given 111 In-labelled antibody. There was clearance of immune complexes to the liver, this organ accumulating up to 90% of the whole body count rate of radiolabel. MA titres of between 1/100 and 1/78000 caused equal perturbation of biodistribution, although below 1/100 the effect was more variable. (orig.)

  13. Inter- and intra-operator reliability and repeatability of shear wave elastography in the liver: a study in healthy volunteers.

    Science.gov (United States)

    Hudson, John M; Milot, Laurent; Parry, Craig; Williams, Ross; Burns, Peter N

    2013-06-01

    This study assessed the reproducibility of shear wave elastography (SWE) in the liver of healthy volunteers. Intra- and inter-operator reliability and repeatability were quantified in three different liver segments in a sample of 15 subjects, scanned during four independent sessions (two scans on day 1, two scans 1 wk later) by two operators. A total of 1440 measurements were made. Reproducibility was assessed using the intra-class correlation coefficient (ICC) and a repeated measures analysis of variance. The shear wave speed was measured and used to estimate Young's modulus using the Supersonics Imagine Aixplorer. The median Young's modulus measured through the inter-costal space was 5.55 ± 0.74 kPa. The intra-operator reliability was better for same-day evaluations (ICC = 0.91) than the inter-operator reliability (ICC = 0.78). Intra-observer agreement decreased when scans were repeated on a different day. Inter-session repeatability was between 3.3% and 9.9% for intra-day repeated scans, compared with to 6.5%-12% for inter-day repeated scans. No significant difference was observed in subjects with a body mass index greater or less than 25 kg/m(2). Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  14. Treatment dose-response in amblyopia therapy: the Monitored Occlusion Treatment of Amblyopia Study (MOTAS).

    Science.gov (United States)

    Stewart, Catherine E; Moseley, Merrick J; Stephens, David A; Fielder, Alistair R

    2004-09-01

    Amblyopia is the commonest visual disorder of childhood. Yet the contributions of the two principal treatments (spectacle wear and occlusion) to outcome are unknown. This study was undertaken to investigate the dose-response relationship of amblyopia therapy. The study comprised three distinct phases: baseline, in which repeat measures of visual function were undertaken to confirm the initial visual deficit; refractive adaptation: an 18-week period of spectacle wear with six weekly measurements of logarithm of the minimum angle of resolution (logMAR) visual acuity; occlusion: in which participants were prescribed 6 hours of "patching" per day. In the latter phase, occlusion was objectively monitored and logMAR visual acuity recorded at 2-week intervals until any observed gains had ceased. Data were obtained from 94 participants (mean age, 5.1 +/- 1.4 years) with amblyopia associated with strabismus (n = 34), anisometropia (n = 23), and both anisometropia and strabismus (n = 37). Eighty-six underwent refractive adaptation. Average concordance with patching was 48%. The relationship between logMAR visual acuity gain and total occlusion dose was monotonic and linear. Increasing dose rate beyond 2 h/d hastened the response but did not improve outcome. More than 80% of the improvement during occlusion occurred within 6 weeks. Treatment outcome was significantly better for children younger than 4 years (n = 17) than in those older than 6 years (n = 24; P = 0.0014). Continuous objective monitoring of the amount of patching therapy received has provided insight into the dose-response relationship of occlusion therapy for amblyopia. Patching is most effective within the first few weeks of treatment, even for those in receipt of a relatively small dose. Further studies are needed to elucidate the neural basis for the dose-response functions. Copyright Association for Research in Vision and Ophthalmology

  15. Once-daily dosing of saquinavir and low-dose ritonavir in HIV-1-infected individuals: a pharmacokinetic pilot study

    NARCIS (Netherlands)

    van Heeswijk, R. P.; Veldkamp, A. I.; Mulder, J. W.; Meenhorst, P. L.; Lange, J. M.; Beijnen, J. H.; Hoetelmans, R. M.

    2000-01-01

    To investigate the steady-state pharmacokinetics of a once-daily dosing regimen of saquinavir soft gelatin capsules in combination with a low dose of ritonavir in HIV-1-infected individuals. Open-label, multi-dose, pharmacokinetic pilot study. Seven HIV-1-infected individuals who were treated with

  16. Comparative study of dose descriptor in pediatric computed tomography exams

    International Nuclear Information System (INIS)

    Finatto, Jerusa Dalbosco; Silva, Ana Maria Marques da; Froner, Ana Paula Pastre; Pimentel, Juliana

    2014-01-01

    This work aims to investigate the dose descriptor, volumetric Computed Tomography Dose Index (CTDI), a pediatric patients sample undergoing to skull CT, comparing the results with the diagnostic reference levels of the literature. Were collected volumetric CTDI values of all skull CT exams performed retrospectively in children of 0-10 years of age in a period of 12 months in a large hospital size. Patients, in a total of 103, were divided into four groups, where the criterion of separation used was age, trying to use the same division used in international references dose descriptors. In all acquisitions we used the pediatric protocol and the Automatic Exposure Control (AEC) available on the equipment. The CDTI values, with and without the use of AEC for pediatric studies, were compared. There was a reduction of approximately 100% in the absorbed dose value due to the use of the AEC. From the data collected and analyzed in this work, it is concluded that the use of dose reduction systems is relevant, such as the Care Dose, to maintain volumetric CTDI values within the reference levels. Also it is important the observation of range of children age to the appropriate choice of parameters used in the test protocol. The values obtained are according to the diagnostic reference levels from the literature

  17. A systematic study on factors affecting patient dose, (1)

    International Nuclear Information System (INIS)

    Otsuka, Akiyoshi; Higashida, Yoshiharu; Utsumi, Hiromoto; Ota, Masaji; Nakanishi, Takashi

    1979-01-01

    In the study of possible reduction in irradiation dose to patients during medical treatments, the following two methods can be considered: (1) To obtain absorbed doses for each part of a body in diagnostic X-ray examinations. (2) To obtain data on factors such as the tube voltage which may affect patient dose. There are a number of reports both at home and abroad concerning the above (1), but very few reports are available concerning the above (2). Moreover, most of them are on fragmentary aspects of each factor and no systematic reports have been made. For this reason, we have taken up, as factors affecting the patient dose, the field size, the tube voltage, and by checking them again, we wanted to obtain some systematic data. Our aim has been fully attained by conducting an experiment. In the ICRP's Publ. 26 issued last year, the idea of the critical organ which had not been fully elucidated in the Publ. 9 was abandoned. As a result, assessment of the irradiation doses has become more rational and the total risk for an individual was obtained. In Japan, the idea proposed in the Publ. 9 is adopted. Therefore, in this paper, we will raise some questions regarding the assessment of the irradiation doses, pointing out at the same time the rationality of the idea put forward in Publ. 26. (author)

  18. Dose-Response for Multiple Biomarkers of Exposure and Genotoxic Effect Following Repeated Treatment of Rats with the Alkylating Agents, MMS and MNU.

    Science.gov (United States)

    Ji, Zhiying; LeBaron, Matthew J; Schisler, Melissa R; Zhang, Fagen; Bartels, Michael J; Gollapudi, B Bhaskar; Pottenger, Lynn H

    2016-05-01

    The nature of the dose-response relationship for various in vivo endpoints of exposure and effect were investigated using the alkylating agents, methyl methanesulfonate (MMS) and methylnitrosourea (MNU). Six male F344 rats/group were dosed orally with 0, 0.5, 1, 5, 25 or 50mg/kg bw/day (mkd) of MMS, or 0, 0.01, 0.1, 1, 5, 10, 25 or 50 mkd of MNU, for 4 consecutive days and sacrificed 24h after the last dose. The dose-responses for multiple biomarkers of exposure and genotoxic effect were investigated. In MMS-treated rats, the hemoglobin adduct level, a systemic exposure biomarker, increased linearly with dose (r (2) = 0.9990, P agents. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments

    Energy Technology Data Exchange (ETDEWEB)

    Stambaugh, Cassandra [Department of Physics, University of South Florida, Tampa, Florida 33612 (United States); Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Dilling, Thomas; Stevens, Craig; Latifi, Kujtim; Zhang, Geoffrey; Moros, Eduardo; Feygelman, Vladimir [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2013-09-15

    Purpose: The effects of respiratory motion on the tumor dose can be divided into the gradient and interplay effects. While the interplay effect is likely to average out over a large number of fractions, it may play a role in hypofractionated [stereotactic body radiation therapy (SBRT)] treatments. This subject has been extensively studied for intensity modulated radiation therapy but less so for volumetric modulated arc therapy (VMAT), particularly in application to hypofractionated regimens. Also, no experimental study has provided full four-dimensional (4D) dose reconstruction in this scenario. The authors demonstrate how a recently described motion perturbation method, with full 4D dose reconstruction, is applied to describe the gradient and interplay effects during VMAT lung SBRT treatments.Methods: VMAT dose delivered to a moving target in a patient can be reconstructed by applying perturbations to the treatment planning system-calculated static 3D dose. Ten SBRT patients treated with 6 MV VMAT beams in five fractions were selected. The target motion (motion kernel) was approximated by 3D rigid body translation, with the tumor centroids defined on the ten phases of the 4DCT. The motion was assumed to be periodic, with the period T being an average from the empirical 4DCT respiratory trace. The real observed tumor motion (total displacement ≤8 mm) was evaluated first. Then, the motion range was artificially increased to 2 or 3 cm. Finally, T was increased to 60 s. While not realistic, making T comparable to the delivery time elucidates if the interplay effect can be observed. For a single fraction, the authors quantified the interplay effect as the maximum difference in the target dosimetric indices, most importantly the near-minimum dose (D{sub 99%}), between all possible starting phases. For the three- and five-fractions, statistical simulations were performed when substantial interplay was found.Results: For the motion amplitudes and periods obtained from

  20. Brain pathology after mild traumatic brain injury: an exploratory study by repeated magnetic resonance examination.

    Science.gov (United States)

    Lannsjö, Marianne; Raininko, Raili; Bustamante, Mariana; von Seth, Charlotta; Borg, Jörgen

    2013-09-01

    To explore brain pathology after mild traumatic brain injury by repeated magnetic resonance examination. A prospective follow-up study. Nineteen patients with mild traumatic brain injury presenting with Glasgow Coma Scale (GCS) 14-15. The patients were examined on day 2 or 3 and 3-7 months after the injury. The magnetic resonance protocol comprised conventional T1- and T2-weighted sequences including fluid attenuated inversion recovery (FLAIR), two susceptibility-weighted sequences to reveal haemorrhages, and diffusion-weighted sequences. Computer-aided volume comparison was performed. Clinical outcome was assessed by the Rivermead Post-Concussion Symptoms Questionnaire (RPQ), Hospital Anxiety and Depression Scale (HADS) and Glasgow Outcome Scale Extended (GOSE). At follow-up, 7 patients (37%) reported ≥  3 symptoms in RPQ, 5 reported some anxiety and 1 reported mild depression. Fifteen patients reported upper level of good recovery and 4 patients lower level of good recovery (GOSE 8 and 7, respectively). Magnetic resonance pathology was found in 1 patient at the first examination, but 4 patients (21%) showed volume loss at the second examination, at which 3 of them reported GOSE scores of 8. Loss of brain volume, demonstrated by computer-aided magnetic resonance imaging volumetry, may be a feasible marker of brain pathology after mild traumatic brain injury.

  1. Use of Different Furnaces to Study Repeatability and Reproducibility of Three Pd-C Cells

    Science.gov (United States)

    Battuello, M.; Florio, M.; Girard, F.

    2010-09-01

    Three different Pd-C eutectic fixed-point cells were prepared and investigated at INRIM. Several tens of phase transition runs were carried out and recorded with both a Si-based radiation thermometer at 950 nm and a precision InGaAs-based thermometer at 1.6 μm. Two of the cells were of the same design with an inner volume of 12 cm3. The third one was smaller with a useful inner volume of 3.6 cm3. The three cells were filled with palladium powder 4N5 or 4N8 pure and graphite powder 6N pure. The repeatability and stability of the inflection point were investigated over a period of 1 year. The noticeably different external dimensions of the two cells, namely, 110 mm and 40 mm in length, allowed the influence of the longitudinal temperature distribution to be investigated. For this purpose, two different furnaces, a single-zone with SiC heaters and a three-zone with MoSi2 heaters, were used. Different operative conditions, namely, temperature steps, melting rate, longitudinal temperature distributions, and position of cells within the furnace, were tested to investigate the reproducibility of the cells. Effects on the duration and shape of the plateaux were also studied. This article gives details of the measurement setup and analyses of the melting plateaux obtained with the different conditions.

  2. Study of domain depinning during repeated polarization reversal in hard PZT ceramics using acoustic emission

    International Nuclear Information System (INIS)

    Prabakar, K; Rao, S P Mallikarjun

    2006-01-01

    Acoustic emission (AE) has been studied during repeated polarization reversals (at 50 Hz) in hard PZT-8 ceramics. The AE and hysteresis loop were monitored at regular intervals of electric field (±20 kV cm -1 peak) application till 10 8 cycles. The sample did not fatigue and an increase in saturation polarization (Ps) was observed. AE was observed with zero threshold till 10 5 cycles when the field was increasing in both half cycles of the applied field. The initial increase in AE activity with increasing number of field cycles till 10 5 was explained on the basis of defect dipoles encouraging the 90 deg. domain switches, i.e. domain depinning. The decrease in AE activity, an increase in threshold field for the observed AE and a further increase in Ps after 10 5 cycles were explained based on the changes in the orientation of defect dipoles with respect to Ps due to the applied field cycles. This was found to encourage the 180 0 domain switches but pin the 90 deg. domains. An increase in AE at 10 8 cycles after applying a higher field of ±25 kV cm -1 was found to be mainly due to microcracking

  3. Smooth muscle fatigue due to repeated urinary bladder neurostimulation: an in vivo study.

    Science.gov (United States)

    Bross, S; Schumacher, S; Scheepe, J R; Seif, C; Jünemann, K P; Alken, P

    1999-01-01

    The presented study investigates the influence of different pause lengths between two consecutive stimulations of the S3 roots on intravesical pressure during bladder neurostimulation. In eight male foxhounds (aged 7-18 months), laminectomy and placement of a modified Brindley electrode were performed. In four series with different pause lengths between two consecutive stimulations (1, 3, 5, and 15 min), the maximum intravesical pressure was measured during stimulation. The changes in intravesical pressure were registered in these four series, each series with six stimulations. A 15-min interval elapsed before the commencement of each series. In the series with a pause length of 15 min, the consecutive stimulations did not result in significant changes in maximum intravesical pressure. In the 5-min series, a significant decrease in intravesical pressure was not observed after the third stimulation. In the 3-min series, a significant decrease was seen at almost every stimulation (average decrease of 3.8% per stimulation) and in the 1-min series, a significant decrease was also observed at almost every stimulation (average decrease of 5.9% per stimulation). The results of repeated bladder neurostimulation demonstrate that the maximum intravesical pressure is dependent on the pause length between two consecutive stimulations. The detrusor muscle showed reversible and short-lived signs of fatigue. This implies the importance of a minimum 5-min interval between two subsequent stimulations. A pause length <5 min leads to a falsification of the results and thus to lower validity of the investigation.

  4. Study on the homocysteine metabolism of patients with unexplained repeated spontaneous abortion

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Objective:To study the metabolism abnormality of homocysteine(Hcy) in unexplained repeated spontaneous abortion(URSA).Methods:The level of Hcy in sera was measured with hyperpressure liquid chromatography(HPLC);Folic acid and vitamin B12 were detected by radioimmune assay;anticardiolipin antibody (ACA) was detected by ELISA.Results:(1)The level of serum Hcy in URSA group was significantly higher than that in control group,showing a statistical significant difference(P<0.01).The level of Hcy was correlated with ages,but not correlated with areas,numbers of miscarriage,gestation age,primary or secondary abortions.(2)The levels of folic acid and vitamin B12 in URSA group were significantly lower than those in control group.The levels of serum folic acid and vitamin B12 were not correlated with age,area,numbers of miscarriage and abortion periods.(3)ACA positive rate in URSA was significantly higher than that in control group.The level of Hcy in ACA(+) group was significantly higher than that in ACA(-) group among URSA patients.Conclusions:Hyperhomocysteinemia,low folic acid state,and ACA were all the independent risk factors for URSA.Lacking of folic acid and vitamin B12 is one of the important causes of hyperhomocysteinemia.ACA and hyperhomocysteinemia may have synergistic action in the occurrence of URSA.

  5. NIST mixed stain study 3: signal intensity balance in commercial short tandem repeat multiplexes.

    Science.gov (United States)

    Duewer, David L; Kline, Margaret C; Redman, Janette W; Butler, John M

    2004-12-01

    Short-tandem repeat (STR) allelic intensities were collected from more than 60 forensic laboratories for a suite of seven samples as part of the National Institute of Standards and Technology-coordinated 2001 Mixed Stain Study 3 (MSS3). These interlaboratory challenge data illuminate the relative importance of intrinsic and user-determined factors affecting the locus-to-locus balance of signal intensities for currently used STR multiplexes. To varying degrees, seven of the eight commercially produced multiplexes used by MSS3 participants displayed very similar patterns of intensity differences among the different loci probed by the multiplexes for all samples, in the hands of multiple analysts, with a variety of supplies and instruments. These systematic differences reflect intrinsic properties of the individual multiplexes, not user-controllable measurement practices. To the extent that quality systems specify minimum and maximum absolute intensities for data acceptability and data interpretation schema require among-locus balance, these intrinsic intensity differences may decrease the utility of multiplex results and surely increase the cost of analysis.

  6. A study on the evaluation of dynamic stress intensity factor in repeated impact bending test

    International Nuclear Information System (INIS)

    Sim, Jae Ki; Cho, Gyu Jae; Han, Gill Young

    1988-01-01

    The purpose of the present paper was to establish the evaluation of the dynamic stress intensity factor in repeated impact three point bending test. Contact force between the impact bar and the cracked beam (simple supported beam) was analyzed by the using Hertz's contact law. In order to clarify the validity of theoretical analysis, experiments of dynamic stress intensity factir k I (t) are made on the cracked beam. The results obtained from this study are as follow: 1. In case of impact force analysis the theoretical result was obtained by the use of the Hertz's contact law. It's result was agreemant with the experimental result. Particularly, it was good agreement in the low impact velocity range. 2. The time variation of the dynamic stress intensity was determined by using the simple formula developed in this pqper. And the validity of it's result can be confirmed by experiment. Particlarly, this theoretical analysis was a good agreement to actual phenomena on from 0.3 msec to 0.65 msec. (Author)

  7. Dose-dependent transitions in mechanisms of toxicity: case studies

    International Nuclear Information System (INIS)

    Slikker, William; Andersen, Melvin E.; Bogdanffy, Matthew S.; Bus, James S.; Cohen, Steven D.; Conolly, Rory B.; David, Raymond M.; Doerrer, Nancy G.; Dorman, David C.; Gaylor, David W.; Hattis, Dale; Rogers, John M.; Setzer, R. Woodrow; Swenberg, James A.; Wallace, Kendall

    2004-01-01

    Experience with dose response and mechanisms of toxicity has shown that multiple mechanisms may exist for a single agent along the continuum of the full dose-response curve. It is highly likely that critical, limiting steps in any given mechanistic pathway may become overwhelmed with increasing exposures, signaling the emergence of new modalities of toxic tissue injury at these higher doses. Therefore, dose-dependent transitions in principal mechanisms of toxicity may occur, and could have significant impact on the interpretation of reference data sets for risk assessment. To illustrate the existence of dose-dependent transitions in mechanisms of toxicity, a group of academic, government, and industry scientists, formed under the leadership of the ILSI Health and Environmental Sciences Institute (HESI), developed a series of case studies. These case studies included acetaminophen, butadiene, ethylene glycol, formaldehyde, manganese, methylene chloride, peroxisome proliferator-activated receptor (PPAR), progesterone/hydroxyflutamide, propylene oxide, vinyl acetate, vinyl chloride, vinylidene chloride, and zinc. The case studies formed the basis for technical discourse at two scientific workshops in 2003

  8. Psychosocial outcomes of Hong Kong Chinese diagnosed with acute coronary syndromes: a prospective repeated measures study.

    Science.gov (United States)

    Chan, Dominic S K; Chau, Janita P C; Chang, Anne M

    2007-08-01

    Western studies have suggested that emotional stress and distress impacted on the morbidity and mortality in people following acute coronary events. Symptoms of anxiety and depression have been associated with re-infarction and death, prolonged recovery and disability and depression may precipitate the client's low self-esteem. This study examined perceived anxiety, depression and self-esteem of Hong Kong Chinese clients diagnosed with acute coronary syndrome (ACS) over a 6-month period following hospital admission. To examine: A prospective, repeated measures design with measures taken on two occasions over a 6-month period; (1) within the 1st week of hospital admission following the onset of ACS and (2) at 6 months follow up. Convenient sample of 182 voluntary consented clients admitted with ACS to a major public hospital in Hong Kong who could communicate in Chinese, complete questionnaires, cognitive intact, and were haemodynamically stable and free from acute chest pain at the time of interview. Baseline data were obtained within 1 week after hospital admission. The follow-up data was collected 6 months after hospital discharge. The Chinese version of the Hospital Anxiety and Depression Scale (HADS), State Self-esteem Scale (SSES), and Rosenberg's Self-Esteem Scale (RSES) were used to assess anxiety and depression, state self-esteem, and trait self-esteem, respectively. Findings suggested gender differences in clients' perception in anxiety, depression and self-esteem. Improvements in clients' perception of these variables were evident over the 6-month period following their acute coronary events. The study confirmed the western notion that psychosocial problems are common among coronary clients and this also applies to Hong Kong Chinese diagnosed with ACS. Further studies to explore effective interventions to address these psychosocial issues are recommended.

  9. The Association Between Oxidative Stress and Depressive Symptom Scores in Elderly Population: A Repeated Panel Study

    Directory of Open Access Journals (Sweden)

    Changwoo Han

    2016-09-01

    Full Text Available Objectives Previous epidemiological studies about oxidative stress and depression are limited by hospital-based case-control design, single-time measurements of oxidative stress biomarkers, and the small number of study participants. Therefore, in this study, we analyzed the association between biomarker of oxidative stress and depressive symptom scores using repeatedly measured panel data from a community-dwelling elderly population. Methods From 2008 to 2010, a total of 478 elderly participants residing in Seoul, Korea, were evaluated three times. Participants underwent the Korean version of the Short Form Generic Depression Scale (SGDS-K test for screening depression, and urinary malondialdehyde (MDA levels were measured as an oxidative stress biomarker. We used a generalized estimating equation with a compound symmetry covariance structure to estimate the effects of oxidative stress on depressive symptom scores. Results A two-fold increase in urinary MDA concentration was significantly associated with a 33.88% (95% confidence interval [CI], 21.59% to 47.42% increase in total SGDS-K scores. In subgroup analyses by gender, a two-fold increase in urinary MDA concentration was significantly associated with increased SGDS-K scores in both men and women (men: 30.88%; 95% CI, 10.24% to 55.37%; women: 34.77%; 95% CI, 20.09% to 51.25%. In bivariate analysis after an SGDS-K score ≥8 was defined as depression, the third and the fourth urinary MDA quartiles showed a significantly increased odds ratio(OR of depression compared to the lowest urinary MDA quartile (third quartile OR, 6.51; 95% CI, 1.77 to 24.00; fourth quartile OR, 7.11; 95% CI, 1.99 to 25.42. Conclusions Our study suggests a significant association between oxidative stress and depressive symptoms in the elderly population.

  10. Sensitivity of dose-finding studies to observation errors.

    Science.gov (United States)

    Zohar, Sarah; O'Quigley, John

    2009-11-01

    The purpose of Phase I designs is to estimate the MTD (maximum tolerated dose, in practice a dose with some given acceptable rate of toxicity) while, at the same time, minimizing the number of patients treated at doses too far removed from the MTD. Our purpose here is to investigate the sensitivity of conclusions from dose-finding designs to recording or observation errors. Certain toxicities may go undetected and, conversely, certain non-toxicities may be incorrectly recorded as dose-limiting toxicities. Recording inaccuracies would be expected to have an influence on final and within trial recommendations and, in this paper, we study in greater depth this question. We focus, in particular on three designs used currently; the standard '3+3' design, the grouped up-and-down design [M. Gezmu, N. Flournoy, Group up-and-down designs for dose finding. Journal of Statistical Planning and Inference 2006; 136 (6): 1749-1764.] and the continual reassessment method (CRM, [J. O'Quigley, M. Pepe, L. Fisher, Continual reassessment method: a practical design for phase 1 clinical trials in cancer. Biometrics 1990; 46 (1): 33-48.]). A non-toxicity incorrectly recorded as a toxicity (error of first kind) has a greater influence in general than the converse (error of second kind). These results are illustrated via figures which suggest that the standard '3+3' design in particular is sensitive to errors of the second kind. Such errors can have a very important impact on drug development in that, if carried through to the Phase 2 and Phase 3 studies, we can significantly increase the probability of failure to detect efficacy as a result of having delivered an inadequate dose.

  11. Visual assessment of the cervical vertebral maturation stages: A study of diagnostic accuracy and repeatability.

    Science.gov (United States)

    Perinetti, Giuseppe; Caprioglio, Alberto; Contardo, Luca

    2014-11-01

    To evaluate the diagnostic accuracy and repeatability of the visual assessment of the cervical vertebral maturation (CVM) stages. Ten operators underwent training sessions in visual assessment of CVM staging. Subsequently, they were asked to stage 72 cases equally divided into the six stages. Such assessment was repeated twice in two sessions (T1 and T2) 4 weeks apart. A reference standard for each case was created according to a cephalometric analysis of both the concavities and shapes of the cervical vertebrae. The overall agreement with the reference standard was about 68% for both sessions and 76.9% for intrarater repeatability. The overall kappa coefficients with the reference standard were up to 0.86 for both sessions, and 0.88 for intrarater repeatability. Overall, disagreements one stage and twp stage apart were 23.5% (T1) and 5.1% (T2), respectively. Sensitivity ranged from 53.3% for CS5 (T1) to 99.9% for CS1 (T2), positive predictive values ranged from 52.4% for CS5 (T2) to 94.3% for CS6 (T1), and accuracy ranged from 83.6% for CS4 (T2) to 94.9% for CS1 (T1). Visual assessment of the CVM stages is accurate and repeatable to a satisfactory level. About one in three cases remain misclassified; disagreement is generally limited to one stage and is mostly seen in stages 4 and 5.

  12. Pulsed total dose damage effect experimental study on EPROM

    International Nuclear Information System (INIS)

    Luo Yinhong; Yao Zhibin; Zhang Fengqi; Guo Hongxia; Zhang Keying; Wang Yuanming; He Baoping

    2011-01-01

    Nowadays, memory radiation effect study mainly focus on functionality measurement. Measurable parameters is few in china. According to the present situation, threshold voltage testing method was presented on floating gate EPROM memory. Experimental study of pulsed total dose effect on EPROM threshold voltage was carried out. Damage mechanism was analysed The experiment results showed that memory cell threshold voltage negative shift was caused by pulsed total dose, memory cell threshold voltage shift is basically coincident under steady bias supply and no bias supply. (authors)

  13. Study of total ionization dose effects in electronic devices

    International Nuclear Information System (INIS)

    Nidhin, T.S.; Bhattacharyya, Anindya; Gour, Aditya; Behera, R.P.; Jayanthi, T.

    2018-01-01

    Radiation effects in electronic devices are a major challenge in the dependable application developments of nuclear power plant instrumentation and control systems. The main radiation effects are total ionization dose (TID) effects, displacement damage dose (DDD) effects and single event effects (SEE). In this study, we are concentrating on TID effects in electronic devices. The focus of the study is mainly on SRAM based field programmable gate arrays (FPGA) along with that the devices of our interest are voltage regulators, flash memory and optocoupler. The experiments are conducted by exposing the devices to gamma radiation in power off condition and the degradation in the performances are analysed

  14. Can results from animal studies be used to estimate dose or low dose effects in humans

    International Nuclear Information System (INIS)

    Thomas, J.M.; Eberhardt, L.L.

    1981-01-01

    A method has been devised to extrapolate biological equilibrium levels between animal species and subsequently to humans. Our initial premise was based on the observation that radionuclide retention is normally a function of metabolism so that direct or indirect measures could be described by a power law based on body weights of test animal species. However, we found that such interspecies comparisons ought to be based on the coefficient of the power equation rather than on the exponential parameter. The method is illustrated using retention data obtained from five non-ruminant species (including humans) that were fed radionuclides with different properties. It appears that biological equilibrium level for radionuclides in man can be estimated using data from mice, rats, and dogs. The need to extrapolate low-dose effects data obtained from small animals (usually rodents) to humans is not unique to radiation dosimetry or radiation protection problems. Therefore, some quantitative problems connected with estimating low-dose effects from other disciplines have been reviewed, both because of the concern about effects induced by the radionuclide moiety of a radiopharmaceutical and those of the nonradioactive component. The possibility of extrapolating low-dose effects calculated from animal studies to human is discussed

  15. Can results from animal studies be used to estimate dose or low dose effects in humans

    International Nuclear Information System (INIS)

    Thomas, J.M.; Eberhardt, L.L.

    1981-01-01

    We have devised a method to extrapolate biological equilibrium levels between animal species and subsequently to humans. Our initial premise was based on the observation that radionuclide retention is normally a function of metabolism so that direct or indirect measures could be described by a power law based on body weights of test animal species. However, we found that such interspecies comparisons ought to be based on the coefficient of the power equation rather than on the exponential parameter. The method is illustrated using retention data obtained from five non-ruminant species (including humans) that were fed radionuclides with different properties. It appears that biological equilibrium level for radionuclides in man can be estimated using data from mice, rats and dogs. The need to extrapolate low-dose effects data obtained from small animals (usually rodents) to humans is not unique to radiation dosimetry or radiation protection problems. Therefore, researchers have reviewed some quantitative problems connected with estimating low-dose effects from other disciplines, both because of the concern about effects induced by the radionuclide moiety of a radiopharmaceutical and those of the nonradioactive component. The possibility of extrapolating low-dose effects calculated from animal studies to humans is discussed

  16. Doses for post-Chernobyl epidemiological studies: are they reliable?

    Science.gov (United States)

    Drozdovitch, Vladimir; Chumak, Vadim; Kesminiene, Ausrele; Ostroumova, Evgenia; Bouville, André

    2016-09-01

    On 26 April 2016, thirty years will have elapsed since the occurrence of the Chernobyl accident, which has so far been the most severe in the history of the nuclear reactor industry. Numerous epidemiological studies were conducted to evaluate the possible health consequences of the accident. Since the credibility of the association between the radiation exposure and health outcome is highly dependent on the adequacy of the dosimetric quantities used in these studies, this paper makes an effort to overview the methods used to estimate individual doses and the associated uncertainties in the main analytical epidemiological studies (i.e. cohort or case-control) related to the Chernobyl accident. Based on the thorough analysis and comparison with other radiation studies, the authors conclude that individual doses for the Chernobyl analytical epidemiological studies have been calculated with a relatively high degree of reliability and well-characterized uncertainties, and that they compare favorably with many other non-Chernobyl studies. The major strengths of the Chernobyl studies are: (1) they are grounded on a large number of measurements, either performed on humans or made in the environment; and (2) extensive effort has been invested to evaluate the uncertainties associated with the dose estimates. Nevertheless, gaps in the methodology are identified and suggestions for the possible improvement of the current dose estimates are made.

  17. Local dose enhancement in radiation therapy: Monte Carlo simulation study

    International Nuclear Information System (INIS)

    Silva, Laura E. da; Nicolucci, Patricia

    2014-01-01

    The development of nanotechnology has boosted the use of nanoparticles in radiation therapy in order to achieve greater therapeutic ratio between tumor and healthy tissues. Gold has been shown to be most suitable to this task due to the high biocompatibility and high atomic number, which contributes to a better in vivo distribution and for the local energy deposition. As a result, this study proposes to study, nanoparticle in the tumor cell. At a range of 11 nm from the nanoparticle surface, results have shown an absorbed dose 141 times higher for the medium with the gold nanoparticle compared to the water for an incident energy spectrum with maximum photon energy of 50 keV. It was also noted that when only scattered radiation is interacting with the gold nanoparticles, the dose was 134 times higher compared to enhanced local dose that remained significant even for scattered radiation. (author)

  18. The Outcome of Repeated Mid Urethral Sling in SUI Treatment after Vaginal Excisions of Primary Failed Sling: Preliminary Study

    Directory of Open Access Journals (Sweden)

    Jacek Kociszewski

    2016-01-01

    Full Text Available Mid urethral sling is the standard in SUI treatment. Nevertheless, the risk of reoperation reaches 9%. There is no consensus as to the best treatment option for complications. A question is raised: what is the optimal way to achieve the best result in patients after primary failure? The aim of the study was to evaluate the outcomes of repeat MUS surgery in patients after excision of the sling with recurrent SUI. We compared its effectiveness with uncomplicated cases treated with TVT. 27 patients who underwent the repeated MUS and 50 consecutive patients after primary TVT were enrolled in the study. After 6 months, we have found that 24 (88.46% patients from repeat sling group and 48 (96% patients after primary sling were dry (1-hour pad test, 2 g or less. The difference between groups was not significant. We showed statistically significant improvement of quality of life in both groups. In conclusion, we showed that repeated sling after MUS excision is almost as effective as primary MUS. We postulate that sling excision and repeated MUS may be the best option for persistent SUI and/or complications after MUS procedures. Further multicenter observations are ongoing as to provide results on bigger group of cases.

  19. Effect of hip braces on brake response time: Repeated measures designed study.

    Science.gov (United States)

    Dammerer, Dietmar; Waidmann, Cornelia; Huber, Dennis G; Krismer, Martin; Haid, Christian; Liebensteiner, Michael C

    2017-08-01

    The question whether or not a patient with a hip brace should drive a car is of obvious importance because the advice given to patients to resume driving is often anecdotal as few scientific data are available on this specific subject. To assess driving ability (brake response time) with commonly used hip braces. Repeated measures design. Brake response time was assessed under six conditions: (1) without a brace (control), (2) with a typical postoperative hip brace with adjustable range of motion and the settings: unrestricted, (3) flexion limited to 70°, (4) extension blocked at 20° hip flexion, (5) both flexion and extension limited (20°/70°) and (6) an elastic hip bandage. Brake response time was assessed using a custom-made driving simulator as used in previous studies. The participants were a convenience sample of able-bodied participants. A total of 70 participants (35 women and 35 men) participated in our study. Mean age was 31.1 (standard deviation: 10.6; range: 21.7-66.4) years. A significant within-subject effect for brake response time was found ( p = 0.009), but subsequent post hoc analyses revealed no significant differences between control and the other settings. Based on our findings, it does not seem mandatory to recommend driving abstinence for patients wearing a hip orthosis. We suggest that our results be interpreted with caution, because (1) an underlying pathological hip condition needs to be considered, (2) the ability to drive a car safely is multifactorial and brake response time is only one component thereof and (3) brake response time measurements were performed only with healthy participants. Clinical relevance Hip braces are used in the context of joint-preserving and prosthetic surgery of the hip. Therefore, clinicians are confronted with the question whether to allow driving a car with the respective hip brace or not. Our data suggest that hip braces do not impair brake response time.

  20. Hearing loss associated with repeated MRI acquisition procedure-related acoustic noise exposure: an occupational cohort study

    NARCIS (Netherlands)

    Bongers, Suzan; Slottje, Pauline; Kromhout, Hans

    2017-01-01

    OBJECTIVE: To study the effects of repeated exposure to MRI-related acoustic noise during image acquisition procedures (scans) on hearing. METHODS: A retrospective occupational cohort study was performed among workers of an MRI manufacturing facility (n=474). Longitudinal audiometry data from the

  1. Advance of study on hormesis of low dose radiation

    International Nuclear Information System (INIS)

    Su Liaoyuan

    2003-01-01

    There have been growing interests in recent years over the effects of low doses of ionizing radiation on human. The paper gives a brief review on the LDR studies, which include LDR-induced hormesis and adaptive response, LDR experiments in vivo or in vitro and epidemiologic investigation, and clinical applications of LDR as well

  2. Population genetic study of 10 short tandem repeat loci from 600 domestic dogs in Korea.

    Science.gov (United States)

    Moon, Seo Hyun; Jang, Yoon-Jeong; Han, Myun Soo; Cho, Myung-Haing

    2016-09-30

    Dogs have long shared close relationships with many humans. Due to the large number of dogs in human populations, they are often involved in crimes. Occasionally, canine biological evidence such as saliva, bloodstains and hairs can be found at crime scenes. Accordingly, canine DNA can be used as forensic evidence. The use of short tandem repeat (STR) loci from biological evidence is valuable for forensic investigations. In Korea, canine STR profiling-related crimes are being successfully analyzed, leading to diverse crimes such as animal cruelty, dog-attacks, murder, robbery, and missing and abandoned dogs being solved. However, the probability of random DNA profile matches cannot be analyzed because of a lack of canine STR data. Therefore, in this study, 10 STR loci were analyzed in 600 dogs in Korea (344 dogs belonging to 30 different purebreds and 256 crossbred dogs) to estimate canine forensic genetic parameters. Among purebred dogs, a separate statistical analysis was conducted for five major subgroups, 97 Maltese, 47 Poodles, 31 Shih Tzus, 32 Yorkshire Terriers, and 25 Pomeranians. Allele frequencies, expected (Hexp) and observed heterozygosity (Hobs), fixation index (F), probability of identity (P(ID)), probability of sibling identity (P(ID)sib) and probability of exclusion (PE) were then calculated. The Hexp values ranged from 0.901 (PEZ12) to 0.634 (FHC2079), while the P(ID)sib values were between 0.481 (FHC2079) and 0.304 (PEZ12) and the P(ID)sib was about 3.35 × 10(-)⁵ for the combination of all 10 loci. The results presented herein will strengthen the value of canine DNA to solving dog-related crimes.

  3. Repeated CT studies of a patient with herpes simplex encephalitis during his entire clinical course

    International Nuclear Information System (INIS)

    Shiraishi, Masahiro; Fukui, Keiji; Takeda, Sadanori; Sadamoto, Kazuhiko; Kimura, Hideki; Sakaki, Saburo.

    1985-01-01

    We encountered a patient with herpes simplex encephalitis whose cerebral lesions were studied by repeated CT scannings during his entire clinical course. The purpose of this paper is to report the earliest lesions of the brain as revealed by CT scans. A 63-year-old man was admitted to our clinic complaining of headache, nausea, fever, and disorientation. On admission, a physical examination showed a high fever, while a neurological examination revealed a stiff neck, a positive Kernig's sign, and disorientation. Laboratory examinations revealed a pleocytosis of the cerebrospinal fluid. Electroencephalograms showed the so-called ''periodic sharp-and-slow-waves complex''. The complement fixation titer for herpes simplex virus was x32 in the serum and x128 in the cerebrospinal fluid, suggesting the diagnosis of herpes simplex encephalitis. We treated him with adenine arabinoside and gamma-globulin, but the patient did not recover; rather, he died of pneumonia and gastrointestinal bleeding three months later. Plain CT scans taken on the 12th day after the onset revealed a low-density area with signs of a slight mass in the region from the right island of Reil to the right uncus. Contrast-enhanced CT scans revealed an irregular enhancement in the low-density area. CT scans taken on the 19th day after the onset showed an extensive low-density area with a streak-like enhancement in the right temporal lobe, which is in aggreement with the findings reported by others as characteristic CT findings for herpes simplex encephalitis. In order to make an early diagnosis of a patient, we should pay attention to a low-density area with an irregular contrast enhancement in the region from the island of Reil to the uncus on a CT scan. (author)

  4. Parsimonious Structural Equation Models for Repeated Measures Data, with Application to the Study of Consumer Preferences

    Science.gov (United States)

    Elrod, Terry; Haubl, Gerald; Tipps, Steven W.

    2012-01-01

    Recent research reflects a growing awareness of the value of using structural equation models to analyze repeated measures data. However, such data, particularly in the presence of covariates, often lead to models that either fit the data poorly, are exceedingly general and hard to interpret, or are specified in a manner that is highly data…

  5. Estimate of dose in interventional radiology: a study of cases

    International Nuclear Information System (INIS)

    Pinto, N.; Braz, D.; Lopes, R.; Vallim, M.; Padilha, L.; Azevedo, F.; Barroso, R.

    2006-01-01

    Values of absorbed dose taken by patients and professionals involved in interventional radiology can be significant mainly for the reason of these proceedings taking long time of fluoroscopy There are many methods to estimate and reduce doses of radiation in the interventional radiology, particularly because the fluoroscopy is responsible for the high dose contribution in the patient and in the professional. The aim of this work is the thermoluminescent dosimetry to estimate the dose values of the extremities of the professionals involved in the interventional radiology and the product dose-area was investigated using a Diamentor. This evaluation is particularly useful for proceedings that interest multiple parts of the organism. In this study were used thermoluminescent dosimeters (LiF:Mg, Ti - Harshaw) to estimate the dose values of the extremities of the professionals and to calibrate them. They were irradiated with X rays at 50 mGy, in Kerma in air and read in the reader Harshaw-5500. The product dose-area (D.A.P.) were obtained through the Diamentor (M2-P.T.W.) calibrated in Cgy.cm 2 fixed in the exit of the X-rays tube. The patients of these study were divided in three groups: individuals submitted to proceedings of embolization, individuals submitted to cerebral and renal arteriography and individuals submitted to proceedings of Transjungular Inthahepatic Porta Systemic Stent Shunt (TIPS). The texts were always carried out by the same group: radiologist doctor), an auxiliary doctor and a nursing auxiliary. The section of interventional radiology has an Angiostar Plus Siemens equipment type arc C, in which there is trifocal Megalix X-ray tube and a intensifier of image from Sirecon 40-4 HDR/33 HDR. In this work the dose estimated values were 137.25 mSv/year for the doctors, 40.27 mSv/year for the nursing and 51.95 mSv/year for the auxiliary doctor and they are below the rule, but in this study it was not taken in consideration the emergency texts as they were

  6. Context matters! sources of variability in weekend physical activity among families: a repeated measures study

    Directory of Open Access Journals (Sweden)

    Robert J. Noonan

    2017-04-01

    Full Text Available Abstract Background Family involvement is an essential component of effective physical activity (PA interventions in children. However, little is known about the PA levels and characteristics of PA among families. This study used a repeated measures design and multiple data sources to explore the variability and characteristics of weekend PA among families. Methods Families (including a ‘target’ child aged 9–11 years, their primary caregiver(s and siblings aged 6–8 years were recruited through primary schools in Liverpool, UK. Participants completed a paper-based PA diary and wore an ActiGraph GT9X accelerometer on their left wrist for up to 16 weekend days. ActiGraph.csv files were analysed using the R-package GGIR version 1.1–4. Mean minutes of moderate-to-vigorous PA (MVPA for each weekend of measurement were calculated using linear mixed models, and variance components were estimated for participant (inter-individual, weekend of measurement, and residual error (intra-individual. Intraclass correlation coefficients (ICC were calculated from the proportion of total variance accounted for by inter-individual sources, and used as a measure of reliability. Diary responses were summed to produce frequency counts. To offer contextual insight into weekend PA among family units, demographic, accelerometer, and diary data were combined to form two case studies representative of low and high active families. Results Twenty-five participants from 7 families participated, including 7 ‘target’ children (mean age 9.3 ± 1.1 years, 4 boys, 6 siblings (mean age 7.2 ± 0.7 years; 4 boys and 12 adults (7 mothers and 5 fathers. There was a high degree of variability in target children’s (ICC = 0.55, siblings (ICC = 0.38, and mothers’ MVPA (ICC = 0.58, but not in fathers’ MVPA (ICC = 0.83. Children’s weekend PA was mostly unstructured in nature and undertaken with friends, whereas a greater proportion of parents’ weekend

  7. Reduction and technical simplification of testing protocol for walking based on repeatability analyses: An Interreg IVa pilot study

    Directory of Open Access Journals (Sweden)

    Nejc Sarabon

    2010-12-01

    Full Text Available The aim of this study was to define the most appropriate gait measurement protocols to be used in our future studies in the Mobility in Ageing project. A group of young healthy volunteers took part in the study. Each subject carried out a 10-metre walking test at five different speeds (preferred, very slow, very fast, slow, and fast. Each walking speed was repeated three times, making a total of 15 trials which were carried out in a random order. Each trial was simultaneously analysed by three observers using three different technical approaches: a stop watch, photo cells and electronic kinematic dress. In analysing the repeatability of the trials, the results showed that of the five self-selected walking speeds, three of them (preferred, very fast, and very slow had a significantly higher repeatability of the average walking velocity, step length and cadence than the other two speeds. Additionally, the data showed that one of the three technical methods for gait assessment has better metric characteristics than the other two. In conclusion, based on repeatability, technical and organizational simplification, this study helped us to successfully define a simple and reliable walking test to be used in the main study of the project.

  8. Repeating Marx

    DEFF Research Database (Denmark)

    Fuchs, Christian; Monticelli, Lara

    2018-01-01

    This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development...... and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show...... that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today....

  9. Deployment Repeatability

    Science.gov (United States)

    2016-08-31

    large cohort of trials to spot unusual cases. However, deployment repeatability is inherently a nonlinear phenomenon, which makes modeling difficult...and GEMS tip position were both tracked during ground testing by a laser target tracking system. Earlier SAILMAST testing in 2005 [8] used...recalls the strategy used by SRTM, where a constellation of lights was installed at the tip of the boom and a modified star tracker was used to track tip

  10. Prospective study on determinants of repeat attendance and attendance patterns in breast cancer screening using the Theory of Planned Behaviour.

    NARCIS (Netherlands)

    Drossaert, Constance H.C.; Boer, Hendrik; Seydel, E.R.

    2003-01-01

    This prospective study, using the Theory of Planned Behaviour (TPB) as a theoretical framework, was carried out to identify the determinants of repeat attendance and attendance patterns in organised breast screening. A group of 2657 women filled out a baseline questionnaire, approximately 8 weeks

  11. Assessing the repeatability of terrestrial laser scanning for monitoring gully topography: A case study from Aratula, Queensland, Australia

    Science.gov (United States)

    Goodwin, Nicholas Robert; Armston, John; Stiller, Isaac; Muir, Jasmine

    2016-06-01

    Terrestrial laser scanning (TLS) technology is a powerful tool for quantifying gully morphology and monitoring change over time. This is due to the high sampling density, sub-centimetre positional accuracies (x, y, z), flexibility of survey configurations and ability to link multiple TLS scans together. However, to ensure correct interpretation of results, research is needed to test the repeatability of TLS derived products to quantify the accuracy and separate 'false' from 'true' geomorphic change. In this study, we use the RIEGL VZ400 scanner to test the repeatability of TLS datasets for mapping gully morphology. We then quantify change following a rainfall event of approximately 100 mm. Our study site, located in south-east Queensland, Australia was chosen to be challenging from a repeatability perspective with high topographic variability. The TLS data capture involved three sets of linked scans: one survey pre-rainfall, to be compared to two surveys post-rainfall acquired on consecutive days. Change is considered negligible in the two post-rainfall scans to test survey repeatability. To verify TLS accuracy, an independent dataset of gully extent and spot heights were acquired using traditional total station techniques. Results confirm that the TLS datasets can be registered multi-temporally at sub-centimetre levels of accuracy in three dimensions. Total station and TLS elevation samples showed strong agreement with a mean error and standard deviation (SD) of residuals equal to 0.052 and 0.047 m, respectively (n = 889). Significantly, our repeatability tests found that return type and pulse deviation influence the accuracy and repeatability of DEMs in gully environments. Analysis of consecutive day datasets showed that DEMs derived from first return data recorded 40% higher SD of residual error than DEMs using multiple return data. A significant empirical relationship between pulse deviation and the variance of residuals for repeat DEMs is also shown (r2 = 0

  12. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    International Nuclear Information System (INIS)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M

    2015-01-01

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations

  13. SU-D-204-06: Dose and Image Quality Evaluation of a Low-Dose Slot-Scanning X-Ray System for Pediatric Orthopedic Studies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Hoerner, M; Lamoureux, R; Rill, L; Arreola, M [Univ Florida, Jacksonville Beach, FL (United States)

    2015-06-15

    Purpose: Children in early teens with scoliosis require repeated radiographic exams over a number of years. The EOS (EOS imaging S.A., Paris, France) is a novel low-dose slot-scanning digital radiographic system designed to produce full-spine images of a free-standing patient. The radiation dose and image quality characteristics of the EOS were evaluated relative to those of a Computed Radiography (CR) system for scoliosis imaging. Methods: For dose evaluation, a full-torso anthropomorphic phantom was scanned five times using the default standard clinical protocols for both the EOS and a CR system, which include both posteroanterior and lateral full-spine views. Optically stimulated luminescent dosimeters (OSLDs), also known as nanoDots™ (Landauer, Inc., Glenwood, IL), were placed on the phantom’s surface to measure entrance skin dose. To assess image quality, MTF curves were generated from sampling the noise levels within the high-contrast regions of a line-pair phantom. Vertical and horizontal distortions were measured for the square line-pair phantom with the EOS system to evaluate the effects of geometric magnification and misalignment with the indicated imaging plane. Results: The entrance skin dose was measured to be 0.4 to 1.1 mGy for the EOS, and 0.7 to 3.6 mGy for the CR study. MTF comparison shows that CR greatly outperforms the EOS, despite both systems having a limiting resolution at 1.8 line-pairs per mm. Vertical distortion was unaffected by phantom positioning, because of the EOS slot-scanning geometry. Horizontal distortion increased linearly with miscentering distance. Conclusion: The EOS system resulted in approximately 70% lower radiation dose than CR for full-spine images. Image quality was found to be inferior to CR. Further investigation is required to see if EOS system is an acceptable modality for performing clinically diagnostic scoliosis examinations.

  14. Dose-escalated CHOP plus etoposide (MegaCHOEP) followed by repeated stem cell transplantation for primary treatment of aggressive high-risk non-Hodgkin lymphoma

    NARCIS (Netherlands)

    Glass, B; Kloess, M; Bentz, M; Schlimok, G; Berdel, WE; Feller, A; Trumper, L; Loeffler, M; Pfreundschuh, M; Schmitz, N

    2006-01-01

    Feasibility, safety, and efficacy of a 4-course high-dose chemotherapy (HDT) protocol including autologous stem cell transplantation (SCT) after courses 2, 3, and 4 was investigated in 110 patients, aged 18 to 60 years, with primary diagnosis of aggressive NHL (aNHL), and lactic dehydrogenase (LDH)

  15. Towards more reliable automated multi-dose dispensing: retrospective follow-up study on medication dose errors and product defects.

    Science.gov (United States)

    Palttala, Iida; Heinämäki, Jyrki; Honkanen, Outi; Suominen, Risto; Antikainen, Osmo; Hirvonen, Jouni; Yliruusi, Jouko

    2013-03-01

    To date, little is known on applicability of different types of pharmaceutical dosage forms in an automated high-speed multi-dose dispensing process. The purpose of the present study was to identify and further investigate various process-induced and/or product-related limitations associated with multi-dose dispensing process. The rates of product defects and dose dispensing errors in automated multi-dose dispensing were retrospectively investigated during a 6-months follow-up period. The study was based on the analysis of process data of totally nine automated high-speed multi-dose dispensing systems. Special attention was paid to the dependence of multi-dose dispensing errors/product defects and pharmaceutical tablet properties (such as shape, dimensions, weight, scored lines, coatings, etc.) to profile the most suitable forms of tablets for automated dose dispensing systems. The relationship between the risk of errors in dose dispensing and tablet characteristics were visualized by creating a principal component analysis (PCA) model for the outcome of dispensed tablets. The two most common process-induced failures identified in the multi-dose dispensing are predisposal of tablet defects and unexpected product transitions in the medication cassette (dose dispensing error). The tablet defects are product-dependent failures, while the tablet transitions are dependent on automated multi-dose dispensing systems used. The occurrence of tablet defects is approximately twice as common as tablet transitions. Optimal tablet preparation for the high-speed multi-dose dispensing would be a round-shaped, relatively small/middle-sized, film-coated tablet without any scored line. Commercial tablet products can be profiled and classified based on their suitability to a high-speed multi-dose dispensing process.

  16. Experimental study on acquisition of knowledge through repeated education and training

    International Nuclear Information System (INIS)

    Sasou, Kunihide; Suzuki, Tomohiro; Yoshimura, Seiichi; Kitamura, Masaharu.

    1997-01-01

    Considering the educational methodology to bring up nuclear power plant operators, the experiments are conducted to discuss the relation between the educational backgrounds of subjects and the knowledge acquired through education and training and also to discuss the effects of repeated training on knowledge acquisition. The results show that the knowledge the subjects obtained through the training depends on their educational backgrounds. The subjects with the higher educational backgrounds seem to properly reorganize the knowledge for the operations with using their deep and meta knowledge. Therefore they can create anticipative responses and easily identify causes of events. The results also show that the repeated education and training given to the subjects with weaker backgrounds makes their knowledge reorganized and their ability becomes closer to the subjects' one with higher educational backgrounds. These results indicate that the knowledge acquired in the earlier stage of the education and training depends on the subjects' educational backgrounds. However, the repeated education and training compensates for the difference. It is also suggested that it will be possible to bring up operators more effectively and properly if the existence of people with different educational backgrounds is recognized and the education/training depending on the educational backgrounds are realized. (author)

  17. Study of the repeatability of histone genes in the ploidy series of wheat and Aegilops

    International Nuclear Information System (INIS)

    Vakhitov, V.A.; Kulikov, A.M.

    1986-01-01

    The hDNA content and number of histone genes in the genomes of different wheat and Aegilops species have been determined by molecular hybridization of DNA with 125 I-histone DNA of Drosophila (L-repeat) on nitrocellulose filters. It has been demonstrated that the proportion of hDNA in the total DNA of diploid and polyploid wheat species is (1.3-7.7) x 10 -3 % (57-850 genes), and in the ploidy series of Aegilops species (2.0-8.0) x 10 -3 % (89-780 genes). The repeatability of the histone genes generally increases at each ploidy level in the species with higher DNA content. At the same time, it has been demonstrated that the DNA content is not the only factor determining repeatability of the histone genes, as some diploid and allopolyploid species have similar number of these genes. It has been concluded that genetic mechanisms are involved in the regulation of the number of histone genes

  18. Early termination of prostate cancer hyperfractionated dose escalation study

    International Nuclear Information System (INIS)

    Forman, Jeffrey D; Porter, Arthur T; Kocheril, Paul; Grignon, David; Orton, Colin

    1996-01-01

    Purpose: This study was initiated to determine the maximum tolerable dose of hyperfractionated radiation in patients with locally advanced prostate cancer. Materials and Methods: Forty-nine patients with locally advanced prostate cancer (T3-T4 Nx, 0, 1 M0 and/or Gleason Score ≥ 8) were treated on the first two steps of a prospective dose-escalation study using hyperfractionated conformal radiotherapy. The first 25 patients received a minimum dose of 78Gy to the clinical tumor volume (CTV) including the prostate, seminal vesicle and a 5mm margin at 1.3Gy b.i.d. The second group (24 patients) received a minimum dose to the CTV of 82.8Gy at 1.15Gy b.i.d. Twenty eight patients received neo-adjuvant hormonal therapy in conjunction with their radiation (8 of 25 patients at 78Gy and 20 of 24 patients at 82.8Gy). Toxicity was scored according to the RTOG grading scale. Efficacy was evaluated by PSA levels and ultrasound guided biopsies. Median follow up was 36 and 18 months for the 78Gy and 82.8Gy dose levels, respectively. Results: No grade 3 or 4 gastrointestinal (GI) or genitourinary (GU) toxicity was noted. At 36 months, the actuarial probability of Grade 2 GI and GU toxicity were 16 and 20%, respectively. Twelve to 18 months following radiation, 41 patients (86%) underwent ultrasound guided biopsy. At 78Gy, 60% of 20 patients had a biopsy which was negative or showed a marked therapeutic effect. At 82.8Gy, these combined rates were 95% in the 21 patients who had biopsies. Nine patients (50%) who did not receive neo-adjuvant hormones had positive biopsies. No patient who received neo-adjuvant hormones plus 78Gy (5 patients) or 82.8Gy (18 patients) had a positive biopsy. Conclusion: Proceeding to the next dose level (87.4Gy) was justified by the lack of severe chronic toxicity. However, in view of the high rate of histologic sterilization when hyperfractionated irradiation was given in conjunction with neo-adjuvant hormonal therapy, it was felt to be unethical to

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

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

  20. Studies of the sensitivity dependence of float zone silicon diodes on gamma absorbed dose

    International Nuclear Information System (INIS)

    Pascoalino, K.C.S.; Santos, T.C. dos; Barbosa, R.F.; Camargo, F. de; Goncalves, J.A.C.; Bueno, C.C.

    2011-01-01

    Full text: Several advantages of silicon diodes which include small size, low cost, high sensitivity and wide availability, make them suitable for dosimetry and for radiation field mapping. However, the small radiation tolerance of ordinary silicon devices has imposed constraints on their application in intense radiation fields such as found in industrial radiation processes. This scenario has been changed with the development of radiation hard silicon devices to be used as track detectors in high-energy physics experiments. Particularly, in this work it is presented the dosimetric results obtained with a batch of nine junction silicon diodes developed, in the framework of CERN RD50 Collaboration, as good candidates for improved radiation hardness. These diodes were produced with 300 micrometer n-type silicon substrate grown by standard float zone technique and processed by the Microelectronics Center of Helsinki University of Technology. The samples irradiation was performed using a Co-60 irradiator (Gammacell 220) which delivers a dose-rate of 2 kGy/h. During the irradiation, the unbiased diodes were connected through low-noise coaxial cables to the input of a KEITHLEY 617 electrometer, in order to monitor the devices photocurrent as a function of the exposure time. To study the response uniformity of the batch of nine diodes as well the sensitivity dependence on the absorbed dose, they were irradiated with different doses from 5 kGy up to 50 kGy. The sensitivity response of each device was investigated through the on-line measurements of the current signals as a function of the exposure time. For doses up to 5 kGy, all diodes exhibited a current decay of almost six percent in comparison with the value registered at the start-time of the irradiation. However, this decrease in the current sensitivity is much smaller than those observed with ordinary diodes for the same absorbed dose. The dose-response curves of the devices were also investigated through the plot

  1. Action of thrice- and five-times repeated exposures of rats to a low dose of X-rays on the carbonhydrate-energy metabolism of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Mironova, T M; Cherkasova, L S; Fomichenko, V G [AN Belorusskoj SSR, Minsk. Inst. Fiziologii

    1975-01-01

    Rats have been subjected to whole-body X-irradiation either 3 times with 2- and 3-day intervals and the total dose of 40 R or 5 times with 3-day intervals and the total dose of 50 R. One day after the end of the 3 times irradiation course the following concentrational changes have been observed in brain hemispheres: increase in the biologically active glycogen-protein complex and creatine phosphate, and decrease in glucose-1-phosphate; after the 5 times irradiation course the changes have not been significant, though an elevated corticosterone level in blood has been noted in both cases. 9 to 15 days after the quintuple irradiation a discoordination of glycogenolysis processes against the background of lowered corticosterone level has been observed. The trend towards restitution of metabolism becomes apparent at the normal hormone level. The glycogenlipid complex has probably an adaptive function.

  2. Dose-effect studies with inhaled plutonium in beagles

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Data are presented for all dogs employed in current life-span dose effect studies with inhaled 239 PuO 2 , and 239 Pu nitrate. Information is presented on the estimated initial alveolar deposition, based on external thorax counts and on estimated lung weights at time of exposure. Information is also provided on the current interpretation of the most prominent clinical-pathological features associated with the death of animals

  3. Metamemory judgments and the benefits of repeated study: improving recall predictions through the activation of appropriate knowledge.

    Science.gov (United States)

    Tiede, Heather L; Leboe, Jason P

    2009-05-01

    Correspondence between judgments of learning (JOLs) and actual recall tends to be poor when the same items are studied and recalled multiple times (e.g., A. Koriat, L. Sheffer, & H. Ma'ayan, 2002). The authors investigated whether making relevant metamemory knowledge more salient would improve the association between actual and predicted recall as a function of repeated exposure to the same study list. In 2 experiments, participants completed 4 study-recall phases involving the same list of items. In addition to having participants make item-by-item JOLs during each study phase, after the 1st study-recall phase participants also generated change-in-recall estimates as to how many more or fewer words they would recall given another exposure to the same study list. This estimation procedure was designed to highlight repeated study as a factor that can contribute to recall performance. Activating metamemory knowledge about the benefits of repeated study for recall in this way allowed participants to accurately express this knowledge in a free-recall context (Experiment 2), but less so when the memory test was cued recall (Experiment 1). Copyright 2009 APA, all rights reserved.

  4. Biokinetic study of 131I following ablation dose administration

    International Nuclear Information System (INIS)

    Nascimento, A.C.H.; Lipsztein, J.L.; Lucena, E.A.; Dantas, B.M.; Rebelo, A.M.O.; Mello, R.C.

    2002-01-01

    Aim: The aim of this investigation is to study biokinetics from internally 131 I deposited for thyroid cancer patients during radioiodine therapy (2 to 3 days), after ablation dose administration (3.7 GBq). These data will help in the elaboration of a metabolic model, which will permit absorbed dose assessment for this specific case, since the biokinetic models for iodine available in scientific literature can not be applied to thyroidectomized patient's studies. Material and Methods: Four females patients, between 22 and 50 years old, without metastases, between 1.9 to 6% of remnant thyroid tissue uptake, agreed to contribute to this study. For the in vivo bioassay, periodical measurements were performed along internment time (2 to 3 days), just after Na 131 I dose administration (3.7 GBq). For this, we used the counting system for Nuclear Medicine model 13S002, IEN/CNEN- Brazil, which was adapted with lead filters, in order to allow the work with high rate counting. The measurements were performed in two geometries: thyroid region and thigh. Results: For each patient, we have done approximately 26 measurements for both geometries, starting at the first hour following dose administration until the release from hospital of patient. The results of counting rate (cps) were plotted against time (h). The measurements suggest a relation between remnant thyroid tissue uptake values and the time where counting rates start decreasing. In addition, it was observed a correlation between remnant thyroid tissue radioactive burdens and the circulating iodine through time. Conclusion: It is necessary to follow-up a greater number of patients aiming to confirm the observed correlations and with a greater number of measurements during the first 24 hours, in other to delimit the time range of increasing and decreasing counting rate

  5. Intra-voxel heterogeneity influences the dose prescription for dose-painting with radiotherapy: a modelling study

    NARCIS (Netherlands)

    Petit, S.F.; Dekker, A.L.A.J.; Seigneuric, R.; Murrer, L.H.P.; Riel, van N.A.W.; Nordsmark, M.; Overgaard, J.; Lambin, Ph.; Wouters, B.G.

    2009-01-01

    The purpose of this study was to increase the potential of dose redistribution by incorporating estimates of oxygen heterogeneity within imaging voxels for optimal dose determination. Cellular oxygen tension (pO2) distributions were estimated for imaging-size-based voxels by solving oxygen

  6. Digital repeat analysis; setup and operation.

    Science.gov (United States)

    Nol, J; Isouard, G; Mirecki, J

    2006-06-01

    Since the emergence of digital imaging, there have been questions about the necessity of continuing reject analysis programs in imaging departments to evaluate performance and quality. As a marketing strategy, most suppliers of digital technology focus on the supremacy of the technology and its ability to reduce the number of repeats, resulting in less radiation doses given to patients and increased productivity in the department. On the other hand, quality assurance radiographers and radiologists believe that repeats are mainly related to positioning skills, and repeat analysis is the main tool to plan training needs to up-skill radiographers. A comparative study between conventional and digital imaging was undertaken to compare outcomes and evaluate the need for reject analysis. However, digital technology still being at its early development stages, setting a credible reject analysis program became the major task of the study. It took the department, with the help of the suppliers of the computed radiography reader and the picture archiving and communication system, over 2 years of software enhancement to build a reliable digital repeat analysis system. The results were supportive of both philosophies; the number of repeats as a result of exposure factors was reduced dramatically; however, the percentage of repeats as a result of positioning skills was slightly on the increase for the simple reason that some rejects in the conventional system qualifying for both exposure and positioning errors were classified as exposure error. The ability of digitally adjusting dark or light images reclassified some of those images as positioning errors.

  7. Population dose from nuclear medicine studies (DOMNES). Contribution of Project DOMNES to Dose Datemed2

    International Nuclear Information System (INIS)

    Ramirez, M. L.; Ruiz, A.; Ferrer, N.; Alonso Farto, J. C.; Alvarez, C.; Rodriguez, M.

    2013-01-01

    The DOMNES Project is created in 2001 to carry out a survey on nuclear medicine procedures used in the Spanish health centers, their frequency and the doses given to patients. In addition, it reports information to Dose Data Project Med 2, focusing on radiology exams. (Author)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  9. CAG repeat polymorphisms in the androgen receptor and breast cancer risk in women: a meta-analysis of 17 studies

    Directory of Open Access Journals (Sweden)

    Mao Q

    2015-08-01

    Full Text Available Qixing Mao,1–3,* Mantang Qiu,1–3,* Gaochao Dong,3 Wenjie Xia,1–3 Shuai Zhang,1,3 Youtao Xu,1,3 Jie Wang,3 Yin Rong,1,3 Lin Xu,1,3 Feng Jiang1,3 1Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, 2Fourth Clinical College of Nanjing Medical University, 3Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People’s Republic of China *These authors contributed equally to this work Abstract: The association between polymorphic CAG repeats in the androgen receptor gene in women and breast cancer susceptibility has been studied extensively. However, the conclusions regarding this relationship remain conflicting. The purpose of this meta-analysis was to identify whether androgen receptor CAG repeat lengths were related to breast cancer susceptibility. The MEDLINE, PubMed, and EMBASE databases were searched through to December 2014 to identify eligible studies. Data and study quality were rigorously assessed by two investigators according to the Newcastle-Ottawa Quality Assessment Scale. The publication bias was assessed by the Begg’s test. Seventeen eligible studies were included in this meta-analysis. The overall analysis suggested no association between CAG polymorphisms and breast cancer risk (odds ratio [OR] 1.031, 95% confidence interval [CI] 0.855–1.245. However, in the subgroup analysis, we observed that long CAG repeats significantly increased the risk of breast cancer in the Caucasian population (OR 1.447, 95% CI 1.089–1.992. Additionally, the risk was significantly increased in Caucasian women carrying two alleles with CAG repeats ≥22 units compared with those with two shorter alleles (OR 1.315, 95% CI 1.014–1.707. These findings suggest that long CAG repeats increase the risk of breast cancer in Caucasian women. However, larger scale case-control studies are needed to validate our results. Keywords: androgen, CAG repeat polymorphism, women

  10. Repeatability of an automated Landolt C test, compared with the early treatment of diabetic retinopathy study (ETDRS) chart testing.

    Science.gov (United States)

    Ruamviboonsuk, Paisan; Tiensuwan, Montip; Kunawut, Catleya; Masayaanon, Patcharapim

    2003-10-01

    To evaluate the repeatability of visual acuity scores from the automated test and compare them with the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Instrument validation study based on a model of repeatability study in two observations. SMETHODS: a prospective, clinic-based, comparative study. A total of 206 participants without ocular diseases and refractive errors in their right eyes were randomly enrolled in the automated group in which 107 participants performed the automated test and the ETDRS group in which 99 participants read the ETDRS chart. All participants were tested with only their right eyes without corrections at 4 meters and came back to have the same tests 1 week later. The automated test used the Landolt rings as optotypes and was conducted by a low-ended personal computer with a 15-inch monitor and a wireless keyboard. The "letter" score calculated by counting every correct response to optotypes, and the "threshold curve" score interpreted from the optotype size at the midpoint of a visual acuity threshold curve. The 95% confidence interval of test-retest of visual acuity scores from the automated test are comparable to the ETDRS chart (.143 compared with.125 for letter scores,.145 compared with.122 for threshold curve scores). The score repeatabilities, calculated from the standard deviations of test-retest, from the automated test are also comparable to the ETDRS chart (.201 compared with.177 for letter scores,.206 compared with.172 for threshold curve scores). All comparisons demonstrated no statistical difference (P >.05). The automated testing system in this study enables practical measuring visual acuity by the Landolt rings. The system's repeatability, which is comparable to the ETDRS chart, supports its role as an alternative tool for measuring outcome in new clinical research. Its ability to practically generate visual acuity threshold curves may also be useful in future clinical research studies.

  11. Determinants of repeated abortion among women of reproductive age attending health facilities in Northern Ethiopia: a case–control study

    Directory of Open Access Journals (Sweden)

    Mussie Alemayehu

    2017-02-01

    Full Text Available Abstract Background Every year, an estimated 19–20 million unsafe abortions take place, almost all in developing countries, leading to 68,000 deaths and millions more injured many permanently. Many women throughout the world, experience more than one abortion in their lifetimes. Repeat abortion is an indicator of the larger problem of unintended pregnancy. This study aimed to identify determinants of repeat abortion in Tigray Region, Ethiopia. Methods Unmatched case–control study was conducted in hospitals in Tigray Region, northern Ethiopia, from November 2014 to June 2015. The sample included 105 cases and 204 controls, recruited from among women seeking abortion care at public hospitals. Clients having two or more abortions (“repeat abortion” were taken as cases and those who had a total of one abortion were taken as controls (“single abortion”. Cases were selected consecutive based on proportional to size allocation while systematic sampling was employed for controls. Data were analyzed using SPSS version 20.0. Binary and multiple variable logistic regression analyses were calculated with 95% CI. Results Mean age of cases was 24 years (±6.85 and 22 years (±6.25 for controls. 79.0% of cases had their sexual debut in less than 18 years of age compared to 57% of controls. 42.2% of controls and 23.8% of cases cited rape as the reason for having an abortion. Study participants who did not understand their fertility cycle and when they were most likely to conceive after menstruation (adjusted odds ratio [AOR] = 2.0, 95% confidence interval [CI]: 1.1–3.7, having a previous abortion using medication (AOR = 3.3, CI: 1.83, 6.11, having multiple sexual partners in the preceding 12 months (AOR = 4.4, CI: 2.39,8.45, perceiving that the abortion procedure is not painful (AOR = 2.3, CI: 1.31,4.26, initiating sexual intercourse before the age of 18 years (AOR = 2.7, CI: 1.49, 5.23 and disclosure to a third

  12. The value of repeating studies and multiple controls: replicated 28-day growth studies of rainbow trout exposed to clofibric acid.

    Science.gov (United States)

    Owen, Stewart F; Huggett, Duane B; Hutchinson, Thomas H; Hetheridge, Malcolm J; McCormack, Paul; Kinter, Lewis B; Ericson, Jon F; Constantine, Lisa A; Sumpter, John P

    2010-12-01

    Two studies to examine the effect of waterborne clofibric acid (CA) on growth-rate and condition of rainbow trout were conducted using accepted regulatory tests (Organisation for Economic Co-operation and Development [OECD] 215). The first study (in 2005) showed significant reductions after 21 d of exposure (21-d growth lowest-observed-effect concentration [LOEC] = 0.1 µg/L, 21-d condition LOEC = 0.1 µg/L) that continued to 28 d. Growth rate was reduced by approximately 50% (from 5.27 to 2.67% per day), while the condition of the fish reduced in a concentration-dependant manner. Additionally, in a concentration-dependent manner, significant changes in relative liver size were observed, such that increasing concentrations of CA resulted in smaller livers after 28-d exposure. A no-observed-effect concentration (NOEC) was not achieved in the 2005 study. An expanded second study (in 2006) that included a robust bridge to the 2005 study, with four replicate tanks of eight individual fish per concentration, did not repeat the 2005 findings. In the 2006 study, no significant effect on growth rate, condition, or liver biometry was observed after 21 or 28 d (28-d growth NOEC = 10 µg/L, 28-d condition NOEC = 10 µg/L), contrary to the 2005 findings. We do not dismiss either of these findings and suggest both are relevant and stand for comparison. However, the larger 2006 study carries more statistical power and multiple-tank replication, so probably produced the more robust findings. Despite sufficient statistical power in each study, interpretation of these and similar studies should be conducted with caution, because much significance is placed on the role of limited numbers of individual and tank replicates and the influence of control animals. Copyright © 2010 SETAC.

  13. Studies of workers exposed to low doses of external radiation

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1991-04-01

    Currently, several epidemiologic studies of workers who have been exposed occupationally to low levels of radiation are being conducted, and include studies of workers in the United States, Great Britain, and Canada involved in the production of both defense materials and nuclear power. This paper focuses on studies that evaluate the possible adverse effects resulting from external exposure to radiation. The radiation risk estimates that have been used to establish radiation protection standards for workers and others have been obtained mainly from studies of persons exposed at high doses and dose rates. However, questions remain with regard to the extrapolation process that has been necessary for estimating low-level radiation risks. Occupational studies provide a direct assessment of risk based on data on persons exposed at the actual levels of interest. If current risk estimates are correct, these studies have very little chance of detecting risk, but can still be used to provide useful upper limits on risks. The studies are also adequate to detect serious underestimation of risks. 36 refs., 3 figs., 3 tabs

  14. A study on the scattered dose in portable chest radiography

    International Nuclear Information System (INIS)

    Ahn, Bong Seon; Lee, Hwan Hyung

    2000-01-01

    The purpose of this study is to survey the present status of portable radiography and the result of free space scattered dose rate when taking a radiography at the general hospital or the university hospital in Taejon city. The results were as follows; The number of cases using portable radiography for three years increased to averages 16.2%, 7.7% per year from January 1st in 1996 to December 31st in 1998. The average of distance of adjacent patients was 219.1 cm at the ward. For portable chest radiography, the free space scattered dose rate was 10.5 mSv/hr at 50 cm distance, 1.8 mSv/hr at 100 cm distance, and 0.2 mSv/hr at 200 cm distance. Therefore, in case of portable chest radiography at the ward, the average of distance of adjacent patients is 219.1 cm, so it dose not have influence on the adjacent patient. But during the portable radiography, a guardian who is close to the patient, doctor, nurse and radiologic technologists has to set up the shield to prevent from the unnecessary radiation or the distance should be as great as possible from the mobile X-ray equipment

  15. Quantum repeated games revisited

    International Nuclear Information System (INIS)

    Frąckiewicz, Piotr

    2012-01-01

    We present a scheme for playing quantum repeated 2 × 2 games based on Marinatto and Weber’s approach to quantum games. As a potential application, we study the twice repeated Prisoner’s Dilemma game. We show that results not available in the classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games proposed by Iqbal and Toor. We point out the drawbacks that make their results unacceptable. (paper)

  16. Review of low dose-rate epidemiological studies and biological mechanisms of dose-rate effects on radiation induced carcinogenesis

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Otsuka, Kensuke; Yoshida, Kazuo

    2015-01-01

    Radiation protection system adopts the linear non-threshold model with using dose and dose-rate effectiveness factor (DDREF). The dose-rate range where DDREF is applied is below 100 mGy per hour, and it is regarded that there are no dose-rate effects at very low dose rate, less than of the order of 10 mGy per year, even from the biological risk evaluation model based on cellular and molecular level mechanisms for maintenance of genetic integrity. Among low dose-rate epidemiological studies, studies of residents in high natural background areas showed no increase of cancer risks at less than about 10 mGy per year. On the other hand, some studies include a study of the Techa River cohort suggested the increase of cancer risks to the similar degree of Atomic bomb survivor data. The difference of those results was supposed due to the difference of dose rate. In 2014, International Commission on Radiological Protection opened a draft report on stem cell biology for public consultations. The report proposed a hypothesis based on the new idea of stem cell competition as a tissue level quality control mechanism, and suggested that it could explain the dose-rate effects around a few milligray per year. To verify this hypothesis, it would be needed to clarify the existence and the lowest dose of radiation-induced stem cell competition, and to elucidate the rate of stem cell turnover and radiation effects on it. As for the turnover, replenishment of damaged stem cells would be the important biological process. It would be meaningful to collect the information to show the difference of dose rates where the competition and the replenishment would be the predominant processes. (author)

  17. A new study on the effects of low doses

    International Nuclear Information System (INIS)

    Dousset, M.; Jammet, H.

    1986-01-01

    A study conducted by prof. Rose has investigated mortality among 39540 employees of the UKAEA, from 1946 to 1978. The three main points are: 1. General mortality and mortality from malignant diseases are lower than in the population of England and Wales (74 and 79 per cent respectively), thus showing no major difference between workers monitored for exposure to radiation and other workers. 2. For monitored workers, the only death cause for which there is a statistically significant correlation with radiation exposure is prostate cancer; there are many cases especially in workers with doses exceeding 0.05 Sv (5 rem) and monitored for tritium. Such a correlation has never been found in any other epidemiologic survey of workers exposed to low-level doses, Hanford (USA) workers especially; conversely, mortality from either multiple myeloma or pancreas cancer is not found here. These facts plead for a cautious interpretation of the results as a whole. 3. A linear representation of the variations of leukemia and cancer mortality vs exposure results in lines, the slopes of which are 3 times higher than those of the lines adopted by ICRP; however, the 95% confidence intervals (-2.7 + 12.4 and -22 + 52.5) are such that the results are compatible with a null effect (slope 0) and even with a benefic effect (negative slope). They are therefore compatible with ICRP estimations. A recent attempt to evaluate the two main investigations on low-dose occupational exposures (UKAEA and Hanford) suggests a dose-response relationship very near that of ICRP [fr

  18. Repeat prenatal corticosteroid prior to preterm birth: a systematic review and individual participant data meta-analysis for the PRECISE study group (prenatal repeat corticosteroid international IPD study group: assessing the effects using the best level of evidence - study protocol

    Directory of Open Access Journals (Sweden)

    Crowther Caroline A

    2012-02-01

    Full Text Available Abstract Background The aim of this individual participant data (IPD meta-analysis is to assess whether the effects of repeat prenatal corticosteroid treatment given to women at risk of preterm birth to benefit their babies are modified in a clinically meaningful way by factors related to the women or the trial protocol. Methods/Design The Prenatal Repeat Corticosteroid International IPD Study Group: assessing the effects using the best level of Evidence (PRECISE Group will conduct an IPD meta-analysis. The PRECISE International Collaborative Group was formed in 2010 and data collection commenced in 2011. Eleven trials with up to 5,000 women and 6,000 infants are eligible for the PRECISE IPD meta-analysis. The primary study outcomes for the infants will be serious neonatal outcome (defined by the PRECISE International IPD Study Group as one of death (foetal, neonatal or infant; severe respiratory disease; severe intraventricular haemorrhage (grade 3 and 4; chronic lung disease; necrotising enterocolitis; serious retinopathy of prematurity; and cystic periventricular leukomalacia; use of respiratory support (defined as mechanical ventilation or continuous positive airways pressure or other respiratory support; and birth weight (Z-scores. For the children, the primary study outcomes will be death or any neurological disability (however defined by trialists at childhood follow up and may include developmental delay or intellectual impairment (developmental quotient or intelligence quotient more than one standard deviation below the mean, cerebral palsy (abnormality of tone with motor dysfunction, blindness (for example, corrected visual acuity worse than 6/60 in the better eye or deafness (for example, hearing loss requiring amplification or worse. For the women, the primary outcome will be maternal sepsis (defined as chorioamnionitis; pyrexia after trial entry requiring the use of antibiotics; puerperal sepsis; intrapartum fever requiring the use

  19. Repeated 28-day oral toxicity study of vinclozolin in rats based on the draft protocol for the "Enhanced OECD Test Guideline No. 407" to detect endocrine effects.

    Science.gov (United States)

    Shin, Jae-Ho; Moon, Hyun Ju; Kim, Tae Sung; Kang, Il Hyun; Ki, Ho Yeon; Choi, Kwang Sik; Han, Soon Young

    2006-09-01

    We performed a 28-day repeated-dose toxicity study of vinclozolin, a widely used fungicide, based on the draft protocol of the "Enhanced OECD Test Guideline 407" (Enhanced TG407) to investigate whether vinclozolin has endocrine-mediated properties according to this assay. Seven-week-old SD rats were administered with vinclozolin daily by oral gavage at dose rates of 0, 3.125, 12.5, 50 and 200 mg/kg/day for at least 28 days. The vinclozolin-treated male rats showed a reduction of epididymis and accessory sex organ weights and an alteration of hormonal patterns. A slight prolongation of the estrous cycle and changes in the estrogen/testosterone ratio and luteinizing hormone level were observed in vinclozolin-treated female rats. Thyroxin concentrations were decreased and thyroid-stimulating hormone concentrations were increased in both sexes; however, there were no compound-related microscopic lesions in the thyroid gland or changes in the thyroid weight. The endocrine-related effects of vinclozolin could be detected by the parameters examined in the present study based on the OECD protocol, suggesting the Enhanced TG407 protocol should be a suitable screening test for the detection of endocrine-mediated effects of chemicals.

  20. Patient dose in image guided radiotherapy: Monte Carlo study of the CBCT dose contribution

    OpenAIRE

    Leotta, Salvatore; Amato, Ernesto; Settineri, Nicola; Basile, Emilia; Italiano, Antonio; Auditore, Lucrezia; Santacaterina, Anna; Pergolizzi, Stefano

    2018-01-01

    Image Guided RadioTherapy (IGRT) is a technique whose diffusion is growing thanks to the well-recognized gain in accuracy of dose delivery. However, multiple Cone Beam Computed Tomography (CBCT) scans add dose to patients, and its contribution has to be assessed and minimized. Aim of our work was to evaluate, through Monte Carlo simulations, organ doses in IGRT due to CBCT and therapeutic MV irradiation in head-neck, thorax and pelvis districts. We developed a Monte Carlo simulation in GAMOS ...

  1. Utilization of a cloned alphoid repeating sequence of human DNA in the study of polymorphism of chromosomal heterochromatin regions

    International Nuclear Information System (INIS)

    Kruminya, A.R.; Kroshkina, V.G.; Yurov, Yu.B.; Aleksandrov, I.A.; Mitkevich, S.P.; Gindilis, V.M.

    1988-01-01

    The chromosomal distribution of the cloned PHS05 fragment of human alphoid DNA was studied by in situ hybridization in 38 individuals. It was shown that this DNA fraction is primarily localized in the pericentric regions of practically all chromosomes of the set. Significant interchromosomal differences and a weakly expressed interindividual polymorphism were discovered in the copying ability of this class of repeating DNA sequences; associations were not found between the results of hybridization and the pattern of Q-polymorphism

  2. Revisiting the TALE repeat.

    Science.gov (United States)

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  3. Use of short tandem repeat sequences to study Mycobacterium leprae in leprosy patients in Malawi and India.

    Directory of Open Access Journals (Sweden)

    Saroj K Young

    2008-04-01

    Full Text Available Inadequate understanding of the transmission of Mycobacterium leprae makes it difficult to predict the impact of leprosy control interventions. Genotypic tests that allow tracking of individual bacterial strains would strengthen epidemiological studies and contribute to our understanding of the disease.Genotyping assays based on variation in the copy number of short tandem repeat sequences were applied to biopsies collected in population-based epidemiological studies of leprosy in northern Malawi, and from members of multi-case households in Hyderabad, India. In the Malawi series, considerable genotypic variability was observed between patients, and also within patients, when isolates were collected at different times or from different tissues. Less within-patient variability was observed when isolates were collected from similar tissues at the same time. Less genotypic variability was noted amongst the closely related Indian patients than in the Malawi series.Lineages of M. leprae undergo changes in their pattern of short tandem repeat sequences over time. Genetic divergence is particularly likely between bacilli inhabiting different (e.g., skin and nerve tissues. Such variability makes short tandem repeat sequences unsuitable as a general tool for population-based strain typing of M. leprae, or for distinguishing relapse from reinfection. Careful use of these markers may provide insights into the development of disease within individuals and for tracking of short transmission chains.

  4. Genetic diversity studies in pea (Pisum sativum L.) using simple sequence repeat markers.

    Science.gov (United States)

    Kumari, P; Basal, N; Singh, A K; Rai, V P; Srivastava, C P; Singh, P K

    2013-03-13

    The genetic diversity among 28 pea (Pisum sativum L.) genotypes was analyzed using 32 simple sequence repeat markers. A total of 44 polymorphic bands, with an average of 2.1 bands per primer, were obtained. The polymorphism information content ranged from 0.657 to 0.309 with an average of 0.493. The variation in genetic diversity among these cultivars ranged from 0.11 to 0.73. Cluster analysis based on Jaccard's similarity coefficient using the unweighted pair-group method with arithmetic mean (UPGMA) revealed 2 distinct clusters, I and II, comprising 6 and 22 genotypes, respectively. Cluster II was further differentiated into 2 subclusters, IIA and IIB, with 12 and 10 genotypes, respectively. Principal component (PC) analysis revealed results similar to those of UPGMA. The first, second, and third PCs contributed 21.6, 16.1, and 14.0% of the variation, respectively; cumulative variation of the first 3 PCs was 51.7%.

  5. NMR study of hexanucleotide d(CCGCGG)2 containing two triplet repeats of fragile X syndrome

    International Nuclear Information System (INIS)

    Monleon, Daniel; Esteve, Vicent; Celda, Bernardo

    2003-01-01

    Long repeated stretches of d(CCG) and tri-nucleotide are crucial mutations that cause hereditary forms of mental retardation (fragile X-syndrome). Moreover, the alternating (CG) di-nucleotide is one of the candidates for Z-DNA conformation. Solution NMR structure of d(CCGCGG) 2 has been solved and is discussed. The determined NMR solution structure is a distorted highly bent B-DNA conformation with increased flexibility in both terminal residues. This conformation differs significantly from the Z-DNA tetramer structure reported for the same hexamer in the crystal state at similar ionic strength by Malinina and co-workers. Crystal structure of d(CCGCGG) 2 at high salt concentration includes a central alternating tetramer in Z-DNA conformation, while the initial cytosine swings out and forms a Watson-Crick base-pair with the terminal guanine of a symmetry-related molecule. In solution, NMR data for sugar ring puckering combined with restrained molecular dynamics simulations starting from a Z-DNA form show that terminal furanose residues could adopt the conformation required for aromatic bases swinging out. Therefore, tetramer formation could be considered possible once the hexanucleotide had previously adopted the Z-DNA form. This work gives some insight into correlations between anomalous crystal structures and their accessibility in the solution state

  6. Neuromuscular dose-response studies: determining sample size.

    Science.gov (United States)

    Kopman, A F; Lien, C A; Naguib, M

    2011-02-01

    Investigators planning dose-response studies of neuromuscular blockers have rarely used a priori power analysis to determine the minimal sample size their protocols require. Institutional Review Boards and peer-reviewed journals now generally ask for this information. This study outlines a proposed method for meeting these requirements. The slopes of the dose-response relationships of eight neuromuscular blocking agents were determined using regression analysis. These values were substituted for γ in the Hill equation. When this is done, the coefficient of variation (COV) around the mean value of the ED₅₀ for each drug is easily calculated. Using these values, we performed an a priori one-sample two-tailed t-test of the means to determine the required sample size when the allowable error in the ED₅₀ was varied from ±10-20%. The COV averaged 22% (range 15-27%). We used a COV value of 25% in determining the sample size. If the allowable error in finding the mean ED₅₀ is ±15%, a sample size of 24 is needed to achieve a power of 80%. Increasing 'accuracy' beyond this point requires increasing greater sample sizes (e.g. an 'n' of 37 for a ±12% error). On the basis of the results of this retrospective analysis, a total sample size of not less than 24 subjects should be adequate for determining a neuromuscular blocking drug's clinical potency with a reasonable degree of assurance.

  7. Studies on the chronic effect of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, E.S.; Chung, I.Y.; Yun, M.S.; Chae, H.S.; Lee, J.Y.

    1982-01-01

    This experiment was carried out to evaluate the chronic hazard of Co-60 low dose radiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages such as below were exposed to 60m rads/week, 500m rads/week and 60 rads/biweek whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period, from 1st week to 3rd week, from 3rd week to 52nd week, from 6th week to 52nd week, and from 22nd week to 52nd week after the birth. All experimental mice were autopsied immediately after being sacrificed at 52nd week. All major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

  8. Radiation dose of staff during positron emission tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Hachiya, Takenori; Shoji, Yasuaki; Hagami, Eiichi; Aizawa, Yasuo; Onodera, Hiroshi; Kan, Mikio; Sasaki, Nobuo; Toyoshima, Eiji; Sugawara, Shigeki

    1989-04-01

    In this paper, the radiation dose of the PET staff including blood sampling operators (medical doctors), PET operators (radio technologists), nurses, blood analysts (medical technologists), radiochemists and cyclotron operators in the cyclotron-PET unit was evaluated. The dose was measured using the film-badges for whole body and TLD ring-badges for fingers. These data were obtained from June, 1986 to May, 1987. In the average dose per month, those with the highest dose were radiochemists. The whole body dose was 1.08 mSv (108 mrem) for /gamma/-ray, 520 /mu/Sv (52 mrem) for /beta/-ray and the dose for fingers, 7.6mSv (760 mrem). The total dose per year both for /gamma/ and /beta/-ray was 19.2 mSv (1.92 rem) for whole body and 91.2 mSv (9.12 rem) for fingers. The staff with the lowest whole body dose for /gamma/-ray per month was blood analysts whose dose was 30 /mu/Sv (3 mrem). For the staff consisting of doctors, radiotechnologists and nurses, the whole body dose per month was 70-170/mu/Sv (7-17 mrem) for /gamma/-ray, 20 /mu/Sv (2 mrem) for /beta/-ray and the dose for fingers per month was 210-540 /mu/Sv (21-54 mrem). For cyclotron operators, the dose was 90 /mu/Sv (9 mrem) for /gamma/-ray, 30 /mu/Sv (3 mrem) for /beta/-ray and the dose for fingers was 160 /mu/Sv (16 mrem). For cyclotron operators and radiochemists, the whole body dose for the neutron ray was measured by solid state nuclear track detector (SSNTD), but the dose was found to be negligible. (author).

  9. Reducing dose in head CT: A phantom study

    International Nuclear Information System (INIS)

    Perez Diaz, M.; Carvalho, A. E.; Andrade, M. E.; Khoury, H. J.

    2013-01-01

    Thirty two head CT scans were acquired employing an anthropomorphic phantom which contains small lesions in posterior fosse, using 2 scanners, one with 64 slices 'Siemens Sensation' and other with 6 slices P hilip Brilliance . Parameters as Tube current (I [mA]), Collimation (C [mm]), spectrum energy (kVp) and dynamic range were changed during studies, looking for the optimal acquisition/processing conditions which permit both, good lesion detectability and the lowest dose. Air kerma (mGy) was measured with a ionization chamber and the air kerma index (Ca,100 [mGy]) was calculated as dose index. Image quality was analyzed by 5 expert criteria using a 5 points-scale (1=poor, 2=fair, 3=good, 4=very good, 5=excellent) and also using 5 Figure of merit in the spatial and frequency domains: Contrast C(%), Contrast to Noise Ratio CNR, Signal to Noise Ratio SNR, Normalized Mean Square Error (NMSE) and the Spectral Distance (SD). Objective and subjective results were correlated. We observed that doses can be diminished until a 25% respect to the usual practice with both technologies, diminishing mainly the mAs, without affecting lesion detection. As a result, we propose an optimized protocol for each scanner as follow: The use of 250 mAs, 120 kVp and the collimation of 6 slices x 1.50 mm per rotation to detect the lesions in posterior fosse with good image quality for the Philips Brilliance 6 tested, while 150 mAs, 100 kVp and slice thickness of 3 mm were needed with the Siemens Sensation 64. (Author)

  10. Doses optimization to patients in computed tomography studies

    International Nuclear Information System (INIS)

    Trujillo Z, F. E.

    2010-09-01

    in recent years the number of studies of computed tomography has been increased, as well as the technology and methodology of these, while the radiological protection to the patient has not advanced to the same step. The IAEA has implemented the Patients Radiation Protection projects, where one of the areas of more interest is the computed tomography. The present work is a brief summary of the actions to realize for the doses optimization imparted to the patients, obtaining an appropriate diagnostic quality in the images at the same time; as it was presented in the course of the project C-RLA/9/067-001. The results that were obtained between Image Quality and Dose by Radiation that is imparted to the patient are shown, as well s the exposition factors that influence in these, according to the project C-RLA/9/067-001. The main actions for the dose optimization are using tension optimized protocols (kV), of load (m As), of collimation/cut thickness, of inclination of the gantry, of the pitch/displacement by rotation, of the reconstruction algorithm (kernel), according to the diagnostic objective to reach and to the patient physical characteristics (like weight and age), as well as to use protections to shield the sensitive organs (mainly those that do not have clinical interest for the procedure). Conclusion: To establish or to begin to implement, insofar as possible, the IAEA recommendations, relating to the clinical practice of the hospitals in Mexico and to the available equipment s type. (Author)

  11. Does assessing suicidality frequently and repeatedly cause harm? A randomized control study.

    Science.gov (United States)

    Law, Mary Kate; Furr, R Michael; Arnold, Elizabeth Mayfield; Mneimne, Malek; Jaquett, Caroline; Fleeson, William

    2015-12-01

    Assessing suicidality is common in mental health practice and is fundamental to suicide research. Although necessary, there is significant concern that such assessments have unintended harmful consequences. Using a longitudinal randomized control design, the authors evaluated whether repeated and frequent assessments of suicide-related thoughts and behaviors negatively affected individuals, including those at-risk for suicide-related outcomes. Adults (N = 282), including many diagnosed with borderline personality disorder (BPD), were recruited through psychiatric outpatient clinics and from the community at large, and were randomly assigned to assessment groups. A control assessment group responded to questions regarding negative psychological experiences several times each day during a 2-week main observation phase. During the same observation period, an intensive suicide assessment group responded to the same questions, along with questions regarding suicidal behavior and ideation. Negative psychological outcomes were measured during the main observation phase (for BPD symptoms unrelated to suicide and for BPD-relevant emotions) and/or at the end of each week during the main observation phase and monthly for 6 months thereafter (for all outcomes, including suicidal ideation and behavior). Results revealed little evidence that intensive suicide assessment triggered negative outcomes, including suicidal ideation or behavior, even among people with BPD. A handful of effects did reach or approach significance, though these were temporary and nonrobust. However, given the seriousness of some outcomes, the authors recommend that researchers or clinicians who implement experience sampling methods including suicide-related items carefully consider the benefits of asking about suicide and to inform participants about possible risks. (c) 2015 APA, all rights reserved).

  12. Patient dose in image guided radiotherapy: Monte Carlo study of the CBCT dose contribution

    Directory of Open Access Journals (Sweden)

    Salvatore Leotta

    2018-02-01

    Full Text Available Image Guided RadioTherapy (IGRT is a technique whose diffusion is growing thanks to the well-recognized gain in accuracy of dose delivery. However, multiple Cone Beam Computed Tomography (CBCT scans add dose to patients, and its contribution has to be assessed and minimized. Aim of our work was to evaluate, through Monte Carlo simulations, organ doses in IGRT due to CBCT and therapeutic MV irradiation in head-neck, thorax and pelvis districts. We developed a Monte Carlo simulation in GAMOS (Geant4-based Architecture for Medicine-Oriented Simulations, reproducing an Elekta Synergy medical linac operating at 6 and 10 MV photon energy, and we set up a scalable anthropomorphic model. After a validation by comparison with the experimental quality indexes, we evaluated the average doses to all organs and tissues belonging to the model for the three cases of irradiated district. Scattered radiation in therapy is larger than that diffused by CBCT by one to two orders of magnitude.

  13. Estimation of the optimal dosing regimen of escitalopram in dogs: A dose occupancy study with [11C]DASB.

    Science.gov (United States)

    Taylor, Olivia; Van Laeken, Nick; Polis, Ingeborgh; Dockx, Robrecht; Vlerick, Lise; Dobbeleir, Andre; Goethals, Ingeborg; Saunders, Jimmy; Sadones, Nele; Baeken, Chris; De Vos, Filip; Peremans, Kathelijne

    2017-01-01

    Although the favourable characteristics of escitalopram as being the most selective serotonin reuptake inhibitor and having an increased therapeutic efficacy via binding on an additional allosteric binding site of the serotonin transporter, its dosing regimen has not yet been optimized for its use in dogs. This study aimed to estimate the optimal dosing frequency and the required dose for achieving 80% occupancy of the serotonin transporters in the basal ganglia. The dosing frequency was investigated by determining the elimination half-life after a four day oral pre-treatment period with 0.83 mg/kg escitalopram (3 administrations/day) and a subsequent i.v. injection 0.83 mg/kg. Blood samples were taken up to 12 hours after i.v. injection and the concentration of escitalopram in plasma was analysed via LC-MSMS. The dose-occupancy relationship was then determined by performing two PET scans in five adult beagles: a baseline PET scan and a second scan after steady state conditions were achieved following oral treatment with a specific dose of escitalopram ranging from 0.5 to 2.5 mg/kg/day. As the elimination half-life was determined to be 6.7 hours a dosing frequency of three administrations a day was proposed for the second part of the study. Further it was opted for a treatment period of four days, which well exceeded the minimum period to achieve steady state conditions. The optimal dosing regimen to achieve 80% occupancy in the basal ganglia and elicit a therapeutic effect, was calculated to be 1.85 mg/kg/day, divided over three administrations. Under several circumstances, such as insufficient response to other SSRIs, concurrent drug intake or in research studies focused on SERT, the use of escitalopram can be preferred over the use of the already for veterinary use registered fluoxetine, however, in case of long-term treatment with escitalopram, regularly cardiac screening is recommended.

  14. Low dose ionizing radiation exposure and cardiovascular disease mortality: cohort study based on Canadian national dose registry of radiation workers

    International Nuclear Information System (INIS)

    Zielinski, J. M.; Band, P. R.; Ashmore, P. J.; Jiang, H.; Shilnikova, N. S.; Tait, V. K.; Krewski, D.

    2009-01-01

    The purpose of our study was to assess the risk of cardiovascular disease (CVD) mortality in a Canadian cohort of 337 397 individuals (169 256 men and 168 141 women) occupationally exposed to ionizing radiation and included in the National Dose Registry (NDR) of Canada. Material and Methods: Exposure to high doses of ionizing radiation, such as those received during radiotherapy, leads to increased risk of cardiovascular diseases. The emerging evidence of excess risk of CVDs after exposure to doses well below those previously considered as safe warrants epidemiological studies of populations exposed to low levels of ionizing radiation. In the present study, the cohort consisted of employees at nuclear power stations (nuclear workers) as well as medical, dental and industrial workers. The mean whole body radiation dose was 8.6 mSv for men and 1.2 mSv for women. Results: During the study period (1951 - 1995), as many as 3 533 deaths from cardiovascular diseases have been identified (3 018 among men and 515 among women). In the cohort, CVD mortality was significantly lower than in the general population of Canada. The cohort showed a significant dose response both among men and women. Risk estimates of CVD mortality in the NDR cohort, when expressed as excess relative risk per unit dose, were higher than those in most other occupational cohorts and higher than in the studies of Japanese atomic bomb survivors. Conclusions: The study has demonstrated a strong positive association between radiation dose and the risk of CVD mortality. Caution needs to be exercised when interpreting these results, due to the potential bias introduced by dosimetry uncertainties, the possible record linkage errors, and especially by the lack of adjustment for non-radiation risk factors. (authors)

  15. Study of dose distribution in high energy photon beam used in radiotherapy

    International Nuclear Information System (INIS)

    Rafaravavy, R.; Raoelina Andriambololona; Bridier, A.

    2007-01-01

    The dose distribution in a medium traversed by a photon beam depends on beam energy, field size and medium nature. Percent depth dose (PDD), Dose Profile (DP) and Opening Collimator Factor (OCF) curves will be established to study this distribution. So, the PDD curves are composed by tree parts: the build-up region, the maximal dose and the quasi-equilibrium region. The maximum dose depth and the dose in depth increase with increasing photon beam energy but the dose surface decreases. The PDD increases with increasing field size.

  16. Comparison of Measured and Estimated CT Organ Doses for Modulated and Fixed Tube Current:: A Human Cadaver Study.

    Science.gov (United States)

    Padole, Atul; Deedar Ali Khawaja, Ranish; Otrakji, Alexi; Zhang, Da; Liu, Bob; Xu, X George; Kalra, Mannudeep K

    2016-05-01

    The aim of this study was to compare the directly measured and the estimated computed tomography (CT) organ doses obtained from commercial radiation dose-tracking (RDT) software for CT performed with modulated tube current or automatic exposure control (AEC) technique and fixed tube current (mAs). With the institutional review board (IRB) approval, the ionization chambers were surgically implanted in a human cadaver (88 years old, male, 68 kg) in six locations such as liver, stomach, colon, left kidney, small intestine, and urinary bladder. The cadaver was scanned with routine abdomen pelvis protocol on a 128-slice, dual-source multidetector computed tomography (MDCT) scanner using both AEC and fixed mAs. The effective and quality reference mAs of 100, 200, and 300 were used for AEC and fixed mAs, respectively. Scanning was repeated three times for each setting, and measured and estimated organ doses (from RDT software) were recorded (N = 3*3*2 = 18). Mean CTDIvol for AEC and fixed mAs were 4, 8, 13 mGy and 7, 14, 21 mGy, respectively. The most estimated organ doses were significantly greater (P < 0.01) than the measured organ doses for both AEC and fixed mAs. At AEC, the mean estimated organ doses (for six organs) were 14.7 mGy compared to mean measured organ doses of 12.3 mGy. Similarly, at fixed mAs, the mean estimated organ doses (for six organs) were 24 mGy compared to measured organ doses of 22.3 mGy. The differences among the measured and estimated organ doses were higher for AEC technique compared to the fixed mAs for most organs (P < 0.01). The most CT organ doses estimated from RDT software are greater compared to directly measured organ doses, particularly when AEC technique is used for CT scanning. Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  17. Studying and measuring the gamma radiation doses in Homs city

    International Nuclear Information System (INIS)

    Sofaan, A. H.

    2001-01-01

    The gamma radiation dose was measured in Homs city by using many portable dosimeters (electronic dosimeter and Geiger-Muller). The measurements were carried out in the indoor and outdoor buildings, for different time period, through one year (1999-2000). High purity germanium detector with low back ground radiation (HpGe) was used to determine radiation element contained in some building and the surrounding soil. The statistical analysis laws were applied to make sure that the measured dose distribution around average value is normal distribution. The measurement indicates that the gamma indoor dose varies from 312μSv/y to 511μSv/y, with the average annual dose of 385μSv/y. However the gamma outdoor dose rate varies from 307μSv/y to 366μSv/y with an average annual dose 385μSv/y. The annual outdoor gamma radiation dose is about %16 lower than the outdoor dose in Homs City. These measurements have indicated that environmental gamma doses in Homs City are relatively low. This is because that most of the soils and rocks in the area are limestone. (author)

  18. Occupational eye lens doses in interventional cardiology. A multicentric study

    International Nuclear Information System (INIS)

    Sánchez, R M; Vano, E; Fernández, J M; Pifarré, X; Ordiales, J M; Rovira, J J; Carrera, F; Goicolea, J; Fernández-Ortiz, A

    2016-01-01

    New European regulation regarding radiological protection of workers and more specifically the new occupational dose limit for the eye lens recently reduced to 20 mSv yr −1 may affect interventional cardiologists. This paper presents a set of measurements of occupational doses performed in five interventional cardiology centres and then compared with the new dose limit. The measurement of occupational doses was performed over the apron at chest level using electronic dosemeters recording H p (10). In one of the centres, scatter dose at goggles was also measured with optically stimulated luminescence dosemeters calibrated in terms of H p (0.07). An average H p (10) over the apron of 46 μSv/procedure was measured for cardiologists. Lower doses were noted in other professionals like second cardiologists, nurses or anaesthetists. Procedures for valvular and other structural heart diseases involved the highest occupational doses, averaging over 100 μSv/procedure. Important differences in occupational doses among centres may be indicative of different radiation protection habits. The new occupational dose limit for the eye lens is likely to be exceeded by those among the interventionalists who do not use protection tools (ceiling suspended screen and/or goggles) even with standard workloads. (paper)

  19. Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose (MTD) in Future Studies.

    Science.gov (United States)

    Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

    2015-07-01

    High doses in Tg.rasH2 carcinogenicity studies are usually set at the maximum tolerated dose (MTD), although this dose selection strategy has not been critically evaluated. We analyzed the body weight gains (BWGs), mortality, and tumor response in control and treated groups of 29 Tg.rasH2 studies conducted at BioReliance. Based on our analysis, it is evident that the MTD was exceeded at the high and/or mid-doses in several studies. The incidence of tumors in high doses was lower when compared to the low and mid-doses of both sexes. Thus, we recommend that the high dose in male mice should not exceed one-half of the estimated MTD (EMTD), as it is currently chosen, and the next dose should be one-fourth of the EMTD. Because females were less sensitive to decrements in BWG, the high dose in female mice should not exceed two-third of EMTD and the next dose group should be one-third of EMTD. If needed, a third dose group should be set at one-eighth EMTD in males and one-sixth EMTD in females. In addition, for compounds that do not show toxicity in the range finding studies, a limit dose should be applied for the 26-week carcinogenicity studies. © 2014 by The Author(s).

  20. MNS16A tandem repeat minisatellite of human telomerase gene: functional studies in colorectal, lung and prostate cancer.

    Science.gov (United States)

    Hofer, Philipp; Zöchmeister, Cornelia; Behm, Christian; Brezina, Stefanie; Baierl, Andreas; Doriguzzi, Angelina; Vanas, Vanita; Holzmann, Klaus; Sutterlüty-Fall, Hedwig; Gsur, Andrea

    2017-04-25

    MNS16A, a functional polymorphic tandem repeat minisatellite, is located in the promoter region of an antisense transcript of the human telomerase reverse transcriptase gene. MNS16A promoter activity depends on the variable number of tandem repeats (VNTR) presenting varying numbers of transcription factor binding sites for GATA binding protein 1. Although MNS16A has been investigated in multiple cancer epidemiology studies with incongruent findings, functional data of only two VNTRs (VNTR-243 and VNTR-302) were available thus far, linking the shorter VNTR to higher promoter activity.For the first time, we investigated promoter activity of all six VNTRs of MNS16A in cell lines of colorectal, lung and prostate cancer using Luciferase reporter assay. In all investigated cell lines shorter VNTRs showed higher promoter activity. While this anticipated indirect linear relationship was affirmed for colorectal cancer SW480 (P = 0.006), a piecewise linear regression model provided significantly better model fit in lung cancer A-427 (P = 6.9 × 10-9) and prostate cancer LNCaP (P = 0.039). In silico search for transcription factor binding sites in MNS16A core repeat element suggested a higher degree of complexity involving X-box binding protein 1, general transcription factor II-I, and glucocorticoid receptor alpha in addition to GATA binding protein 1.Further functional studies in additional cancers are requested to extend our knowledge of MNS16A functionality uncovering potential cancer type-specific differences. Risk alleles may vary in different malignancies and their determination in vitro could be relevant for interpretation of genotype data.

  1. Prolonged Repeated Acupuncture Stimulation Induces Habituation Effects in Pain-Related Brain Areas: An fMRI Study

    Science.gov (United States)

    Li, Chuanfu; Yang, Jun; Park, Kyungmo; Wu, Hongli; Hu, Sheng; Zhang, Wei; Bu, Junjie; Xu, Chunsheng; Qiu, Bensheng; Zhang, Xiaochu

    2014-01-01

    Most previous studies of brain responses to acupuncture were designed to investigate the acupuncture instant effect while the cumulative effect that should be more important in clinical practice has seldom been discussed. In this study, the neural basis of the acupuncture cumulative effect was analyzed. For this experiment, forty healthy volunteers were recruited, in which more than 40 minutes of repeated acupuncture stimulation was implemented at acupoint Zhusanli (ST36). Three runs of acupuncture fMRI datasets were acquired, with each run consisting of two blocks of acupuncture stimulation. Besides general linear model (GLM) analysis, the cumulative effects of acupuncture were analyzed with analysis of covariance (ANCOVA) to find the association between the brain response and the cumulative duration of acupuncture stimulation in each stimulation block. The experimental results showed that the brain response in the initial stage was the strongest although the brain response to acupuncture was time-variant. In particular, the brain areas that were activated in the first block and the brain areas that demonstrated cumulative effects in the course of repeated acupuncture stimulation overlapped in the pain-related areas, including the bilateral middle cingulate cortex, the bilateral paracentral lobule, the SII, and the right thalamus. Furthermore, the cumulative effects demonstrated bimodal characteristics, i.e. the brain response was positive at the beginning, and became negative at the end. It was suggested that the cumulative effect of repeated acupuncture stimulation was consistent with the characteristic of habituation effects. This finding may explain the neurophysiologic mechanism underlying acupuncture analgesia. PMID:24821143

  2. Depressive disorder, coronary heart disease, and stroke: dose-response and reverse causation effects in the Whitehall II cohort study.

    Science.gov (United States)

    Brunner, Eric J; Shipley, Martin J; Britton, Annie R; Stansfeld, Stephen A; Heuschmann, Peter U; Rudd, Anthony G; Wolfe, Charles D A; Singh-Manoux, Archana; Kivimaki, Mika

    2014-03-01

    Systematic reviews examining associations of depressive disorder with coronary heart disease and stroke produce mixed results. Failure to consider reverse causation and dose-response patterns may have caused inconsistencies in evidence. This prospective cohort study on depressive disorder, coronary heart disease, and stroke analysed reverse causation and dose-response effects using four 5-year and three 10-year observation cycles (total follow up 24 years) based on multiple repeat measures of exposure. Participants in the Whitehall II study (n = 10,036, 31,395 person-observations, age at start 44.4 years) provided up to six repeat measures of depressive symptoms via the 30-item General Health Questionnaire (GHQ-30) and one measure via Center for Epidemiologic Studies Depression Scale (CES-D). The cohort was followed up for major coronary events (coronary death/nonfatal myocardial infarction) and stroke (stroke death/morbidity) through the national mortality register Hospital Episode Statistics, ECG-screening, medical records, and self-report questionnaires. GHQ-30 caseness predicted stroke over 0-5 years (age-, sex- and ethnicity-adjusted HR 1.60, 95% CI 1.1-2.3) but not over 5-10 years (HR 0.94, 95% CI 0.6-1.4). Using the last 5-year observation cycle, cumulative GHQ-30 caseness was associated with incident coronary heart disease in a dose-response manner (1-2 times a case: HR 1.12, 95% CI 0.7-1.7; 3-4 times: HR 2.06, 95% CI 1.2-3.7), and CES-D caseness predicted coronary heart disease (HR 1.81, 95% CI 1.1-3.1). There was evidence of a dose-response effect of depressive symptoms on risk of coronary heart disease. In contrast, prospective associations of depressive symptoms with stroke appeared to arise wholly or partly through reverse causation.

  3. Evaluation of 90-day Repeated Dose Oral Toxicity, Glycometabolism, Learning and Memory Ability, and Related Enzyme of Chromium Malate Supplementation in Sprague-Dawley Rats.

    Science.gov (United States)

    Feng, Weiwei; Wu, Huiyu; Li, Qian; Zhou, Zhaoxiang; Chen, Yao; Zhao, Ting; Feng, Yun; Mao, Guanghua; Li, Fang; Yang, Liuqing; Wu, Xiangyang

    2015-11-01

    Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.

  4. A Study on the Exposure Parameter and the Patient Dose for Digital Radiography System in Daegoo

    International Nuclear Information System (INIS)

    Jo, Gwang Ho; Kang, Yeopng Han; Kim, Bu Sun

    2008-01-01

    Digital imaging for general radiography has many advantages over the film/screen systems, including a wider dynamic range and the ability to manipulate the images produced. The wider range means that acceptable images may by acquired at a range of dose levels, and therefore repeat exposures can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency can be reduced. Digital imaging can result in the over use of radiation, however, because there is a tendency for images to be acquired at too high a dose. We investigated the actual exposure dose conditions on general radiography and a questionnaire survey was conducted with radiotechnologiest at medical institutions using digital radiology system. As a results, the dose of exposure was not controlled with patient's figure and dose optimization but was controlled by worker's convenience and image quality. Radio-technologiests often set up the exposure dose regardless of patient figure and body part to be examined. Many organizations, such as the International Commission on Radiological Protection, recommend to keep the dose as low as possible. In addition, they strongly recommend to keep the optimal but minimal dosage by proper training programs and constant quality control, including frequent patient dose evaluations and education.

  5. Risk of solid cancer in low dose-rate radiation epidemiological studies and the dose-rate effectiveness factor.

    Science.gov (United States)

    Shore, Roy; Walsh, Linda; Azizova, Tamara; Rühm, Werner

    2017-10-01

    Estimated radiation risks used for radiation protection purposes have been based primarily on the Life Span Study (LSS) of atomic bomb survivors who received brief exposures at high dose rates, many with high doses. Information is needed regarding radiation risks from low dose-rate (LDR) exposures to low linear-energy-transfer (low-LET) radiation. We conducted a meta-analysis of LDR epidemiologic studies that provide dose-response estimates of total solid cancer risk in adulthood in comparison to corresponding LSS risks, in order to estimate a dose rate effectiveness factor (DREF). We identified 22 LDR studies with dose-response risk estimates for solid cancer after minimizing information overlap. For each study, a parallel risk estimate was derived from the LSS risk model using matching values for sex, mean ages at first exposure and attained age, targeted cancer types, and accounting for type of dosimetric assessment. For each LDR study, a ratio of the excess relative risk per Gy (ERR Gy -1 ) to the matching LSS ERR risk estimate (LDR/LSS) was calculated, and a meta-analysis of the risk ratios was conducted. The reciprocal of the resultant risk ratio provided an estimate of the DREF. The meta-analysis showed a LDR/LSS risk ratio of 0.36 (95% confidence interval [CI] 0.14, 0.57) for the 19 studies of solid cancer mortality and 0.33 (95% CI 0.13, 0.54) when three cohorts with only incidence data also were added, implying a DREF with values around 3, but statistically compatible with 2. However, the analyses were highly dominated by the Mayak worker study. When the Mayak study was excluded the LDR/LSS risk ratios increased: 1.12 (95% CI 0.40, 1.84) for mortality and 0.54 (95% CI 0.09, 0.99) for mortality + incidence, implying a lower DREF in the range of 1-2. Meta-analyses that included only cohorts in which the mean dose was LDR data provide direct evidence regarding risk from exposures at low dose rates as an important complement to the LSS risk estimates used

  6. Sibutramine in weight control: a dose-ranging, efficacy study.

    Science.gov (United States)

    Weintraub, M; Rubio, A; Golik, A; Byrne, L; Scheinbaum, M L

    1991-09-01

    We tested the safety and efficacy of sibutramine, 5 and 20 mg, and placebo on weight loss. Medication was added to caloric restriction, behavior modification, and exercise in a parallel-group, double-blind clinical trial. Participants were 130% to 180% of ideal body weight and in good health. The study lasted 12 weeks over Thanksgiving, Christmas, and New Year's Day. Weight loss during 8 weeks of study medication was: placebo, 1.4 +/- 2.1 kg (n = 19); 5 mg sibutramine, 2.9 +/- 2.3 kg (n = 18); and 20 mg sibutramine, 5.0 +/- 2.7 kg (n = 18) (p less than 0.05 sibutramine, 5 and 20 mg, versus placebo; p less than 0.05 sibutramine, 20 mg versus 5 mg). There is a significant dose-effect relationship. Five participants left the study before completion, all because of adverse events; placebo (one patient), 5 mg sibutramine (one patient), and 20 mg sibutramine (three patients). Sleep difficulties were noted by eight participants (20 mg sibutramine, seven patients; 5 mg, one patient; and placebo, no patients). Six of 21 participants receiving 20 mg complained of irritability, unusual impatience, or "excitation." Sibutramine, 5 and 20 mg, added to a multimodal program assisted participants in losing weight.

  7. Repeated exposure to the thin ideal and implications for the self : Two weight loss program studies

    NARCIS (Netherlands)

    Klesse, A.K.; Goukens, C.; Geyskens, K.; de Ruyter, K.

    2012-01-01

    Exposure to thin models results in self-esteem shifts that influence people's motivation to diet. This research study applies a goal perspective to explain the effect of exposure to thin models on dieters' motivation to lose weight. Two (one-week) weight loss program studies that included treatment

  8. Visual Perception Studies in CT images obtained lo low dose

    International Nuclear Information System (INIS)

    Adame Brooks, D.; Miller-Clemente, R. A.

    2015-01-01

    This paper has as aims to describe a strategy to evaluate the diagnostic quality of obtained images of method for dose reduction, with the purpose of determining the dose value or values from which the image quality is significantly degraded making it insufficient for the diagnostic. To complement and have an estimate of the quality of the images we established a group of measures of objective type, and the diagnostic quality of the images was evaluated through a group of observers using the analysis ROC and LROC. For ROC and LROC analyzes the behavior of the area under the curve in relation to the four proposed dose levels was obtained. For high dose levels, detection was good. The values of area under the curve decreased as the dose rate decreased, falling to values indicating low accuracy in diagnosis. This result indicates that the area under the curve decreases by the dose rate. We conclude that the objective quality measures selected are representative of the changes that occur in the resulting image and provided information on changes in the perception of observers. The experiments ROC and LROC allowed determine the range of dose values from which the image degradation causes a low accuracy in the diagnostic. (Author)

  9. Dose delivery study for a novel compact proton accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Kim Melanie

    2014-01-15

    Proton therapy has played an important role in the treatment of cancer with radiation therapy for more than 60 years. Active spot scanning to deliver highly conformal dose to the tumor has been developed. However, the availability of proton therapy to the patients is still limited, partly, due to the high costs and sizes of large proton therapy centers. Therefore, a novel compact proton single room facility based on a linear accelerator mounted on a gantry has been proposed, named TULIP (TUrning LInac for Proton therapy). This accelerator allows for active energy variation on a milliseconds time scale. This work aims to assess the possibilities of dose delivery with TULIP to exploit its beneficial features with respect to dose delivery. We developed a software tool, simulating the dose delivery to the tumor. By means of this software tool, we assessed different delivery methods and found 3D spot scanning to be superior to rotational dose delivery with regard to dose and irradiation time. In a second part, we expanded the investigations to dose delivery to moving targets. Due to fast energy variation, we found TULIP to be preferably suitable for rescanning, confirmed by irradiation times of only a few minutes.

  10. Dose delivery study for a novel compact proton accelerator

    International Nuclear Information System (INIS)

    Kraus, Kim Melanie

    2014-01-01

    Proton therapy has played an important role in the treatment of cancer with radiation therapy for more than 60 years. Active spot scanning to deliver highly conformal dose to the tumor has been developed. However, the availability of proton therapy to the patients is still limited, partly, due to the high costs and sizes of large proton therapy centers. Therefore, a novel compact proton single room facility based on a linear accelerator mounted on a gantry has been proposed, named TULIP (TUrning LInac for Proton therapy). This accelerator allows for active energy variation on a milliseconds time scale. This work aims to assess the possibilities of dose delivery with TULIP to exploit its beneficial features with respect to dose delivery. We developed a software tool, simulating the dose delivery to the tumor. By means of this software tool, we assessed different delivery methods and found 3D spot scanning to be superior to rotational dose delivery with regard to dose and irradiation time. In a second part, we expanded the investigations to dose delivery to moving targets. Due to fast energy variation, we found TULIP to be preferably suitable for rescanning, confirmed by irradiation times of only a few minutes.

  11. Repeated treatments of drooling with botulinum toxin B in neurology

    DEFF Research Database (Denmark)

    Møller, Eigild; Daugaard, Dorthe; Holm, Ole

    2015-01-01

    OBJECTIVES: To investigate efficacy, saliva flow, and composition in repeated BoNT-B treatments of drooling. MATERIALS AND METHODS: Seventeen neurological patients (median 66 years), referred for treatment of drooling participated in this observational study. Median total doses of 4000 units...

  12. Close contact dose: a radioiodine therapy case study

    International Nuclear Information System (INIS)

    Tuchyna, T.

    2002-01-01

    Full text: External radiation dose rates were measured immediately post administration and periodically thereafter at 0.3 and 1.0 m from a patient who received a 555 MBq therapeutic dose of I-131. The dose received by the partner during the close contact period of sleep was measured with an anthropomorphic RANDO phantom representing a standard man with ICRP60 organs critical for dosimetry. RANDO occupied the same bed as the patient at a skin to skin distance of 30 cm with up to 30 TLD rods (1 x 1 x 6mm, LiF:Mg) inserted at critical organ positions within the phantom. The measurements were compared with empirical estimates provided by the Close Contact Dose Spreadsheet (Cormack and Shearer, 1998). The measured external dose rate of 19.3microSv/hr obtained immediately post administration rose slightly, to 26.3microSv/hr during the first 12 hours, however subsequently demonstrated a slow decrease. The TLDs embed- ded in RANDO recorded a dose of 0.24mSv during the hours of sleep. The total dose received by the partner over the two days was 0.29mSv, which compared favourably with a figure of 0.31mSv obtained by the Close Contact Dose Spreadsheet. The doses received demonstrate the validity of restricting patient partner contact during the hours of sleep within the first few days post administration. Monitoring of the bedroom, bed linen, bathroom, toilet and personal effects showed slight levels of contamination ranging from background to 20 cps. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  13. Study on the evaluation of radiation doses in dental radiography. Doses and risks due to dental full mouth examination

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, K [Kanagawa Dental Coll., Yokosuka (Japan)

    1980-09-01

    Radiation doses and possible biological risks due to dental full mouth examination (adult: 10-film technique, child: 6-film technique) were evaluated based on preliminary experiments and statistical surveillance of patients' records. Dosimetrical studies were performed by using head and neck phantoms and a dental x-ray tube. Radiation doses were measured by x-ray films and thermoluminescence dosimeters. For the obtained doses of skin, eyes, thyroid gland and bone marrow, the biological risk of leukemia and thyroid cancer was discussed on the statistical basis of patients at Kanagawa Dental College Hospital. The major findings were as follows: The total number of patients who recieved full mouth x-ray examination at Kanagawa Dental College Hospital in 1978 was 1,099. The number of male patients was 382 (3,804 films) and that of female patients was 717 (7,138 films). In both sexes, the number of patients was the greatest in the group of 8 - 14 years of age. The collective doses of bone marrow due to full mouth 10-film examination performed at Kanagawa Dental College Hospital in 1978 were approximately 6.0 rad, which could induce leukemia with a probability of 1/8,000. The collective doses of thyroid gland were approximately 13 rad, which could induce lethal thyroid cancer with a probability of 1/15,000. The radiation dose due to the dental radiography for examination at Kanagawa Dental College Hospital was proved to be apparently below the level that could actually induce radiation injuries. But the collective radiation doses due to dental examination in Japan as a whole were approximately 8,000 times greater than that in Kanagawa Dental College Hospital.

  14. Broad and narrow personality traits as markers of one-time and repeated suicide attempts: A population-based study

    Directory of Open Access Journals (Sweden)

    Vitaro Frank

    2008-03-01

    Full Text Available Abstract Background Studying personality traits with the potential to differentiate between individuals engaging in suicide attempts of different degrees of severity could help us to understand the processes underlying the link of personality and nonfatal suicidal behaviours and to identify at-risk groups. One approach may be to examine whether narrow, i.e., lower-order personality traits may be more useful than their underlying, broad personality trait dimensions. Methods We investigated qualitative and quantitative differences in broad and narrow personality traits between one-time and repeated suicide attempters in a longitudinal, population-based sample of young French Canadian adults using two multivariate regression models. Results One broad (Compulsivity: OR = 2.0; 95% CI 1.2–3.5 and one narrow personality trait (anxiousness: OR = 1.1; 95% CI 1.01–1.1 differentiated between individuals with histories of repeated and one-time suicide attempts. Affective instability [(OR = 1.1; 95% CI 1.04–1.1] and anxiousness [(OR = .92; 95% CI .88–.95], on the other hand, differentiated between nonattempters and one-time suicide attempters. Conclusion Emotional and cognitive dysregulation and associated behavioural manifestations may be associated with suicide attempts of different severity. While findings associated with narrow traits may be easier to interpret and link to existing sociobiological theories, larger effect sizes associated with broad traits such as Compulsivity may be better suited to objectives with a more clinical focus.

  15. URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

    OpenAIRE

    Bezrati-Benayed, I.; Nasrallah, F.; Feki, M.; Chamari, K.; Omar, S.; Alouane-Trabelsi, L.; Ben Mansour, A.; Kaabachi, N.

    2014-01-01

    Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatog...

  16. PARAMETER REPEATABILITY FOR ECONOMY. A CASE STUDY OF A SIMPLE LINEAR ELECTRICAL DEVICE

    Directory of Open Access Journals (Sweden)

    Antoni Drapella

    2017-06-01

    Full Text Available This paper is the first installment of a projected three-part study devoted to both input and output parameter randomness that electrical circuit designers deal with in their work. Parts of the study will differ in the complexity of schemes considered. This paper aims at presenting the methodology while leaving aside the analysis of complex circuits. Therefore, only voltage dividers have been taken into consideration. Four probability distributions of resistor values have been tried: uniform, Gaussian, Laplace and triangular.

  17. Predicting In Vivo Effect Levels for Repeat Dose Systemic Toxicity using Chemical, Biological, Kinetic and Study Covariates

    Science.gov (United States)

    In an effort to ensure chemical safety while reducing reliance on animal testing, USEPA and L’Oréal have collaborated to address a major challenge in chemical safety assessment using alternative approaches: the prediction of points-of-departure (POD) of systemic effects. Systemic...

  18. 40 CFR 799.9365 - TSCA combined repeated dose toxicity study with the reproduction/developmental toxicity screening...

    Science.gov (United States)

    2010-07-01

    ... fecundity or well-known high incidence of developmental defects should not be used. Healthy virgin animals... p.m., Monday through Friday, except legal holidays. (1) Mitsumori, K., Kodama, Y., Uchida, O...

  19. Who repeats? A follow-up study of state hospital patients' firesetting behavior.

    Science.gov (United States)

    Geller, J L; Fisher, W H; Bertsch, G

    1992-01-01

    The authors report on a population of psychiatric patients who were studied over a 6.75 year period to determine the occurrences of firesetting behavior noted in their psychiatric inpatient records. Two groups of 50 patients each were drawn from an earlier study and were matched by sex, age, and diagnoses. One group of patients had prior firesetting behavior; the other did not. Firesetting behavior was found not only in patients originally identified as having previously engaged in this behavior, but also in those with no documented history of this act prior to the period of the study. Patients having firesetting behavior in their past psychiatric record set more actual fires. Total number of episodes of firesetting behavior, however, was not significantly different between the two groups. Results are discussed in terms of the communicative function of firesetting and the dilemma of clinical prediction.

  20. Hearing loss associated with repeated MRI acquisition procedure-related acoustic noise exposure: an occupational cohort study.

    Science.gov (United States)

    Bongers, Suzan; Slottje, Pauline; Kromhout, Hans

    2017-11-01

    To study the effects of repeated exposure to MRI-related acoustic noise during image acquisition procedures (scans) on hearing. A retrospective occupational cohort study was performed among workers of an MRI manufacturing facility (n=474). Longitudinal audiometry data from the facility's medical surveillance scheme collected from 1973 to 2010 were analysed by studying the association of cumulative exposure to MRI-related acoustic noise from voluntary (multiple) MRI scans and the hearing threshold of the volunteer. Repeated acoustic noise exposure during volunteer MRI scans was found to be associated with a small exposure-dependent increased rate change of hearing threshold level (dB/year), but the association was only found related to the number of voluntary MRI scans and not to modelled cumulative noise exposure (dB*hour) based on MRI-system type. The increased rate change of hearing threshold level was found to be statistically significant for the frequencies 500, 1000, 2000, 3000 and 4000 Hz in the right ear. From our longitudinal cohort study, it appeared that exposure to noise from voluntarily MRI scans may have resulted in a slight amount of hearing loss. Mandatory use of hearing protection might have prevented more severe hearing loss. Lack of consistency in findings between the left and right ears and between the two exposure measures prohibits definitive conclusions. Further research that addresses the study's methodological limitations is warranted to corroborate our findings. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  1. Comparative study about doses and radiological protection in gastrointestinal fluoroscopy

    International Nuclear Information System (INIS)

    Caneravo, L.V.; Borges, J.C.; Carlos, M.T.; Koch, H.A.

    1996-01-01

    The Radiation Protection and Dosimetry Institute of the National Nuclear Energy Commission (IRD/CNEN) and the Radiodiagnostic Service of the Rio de Janeiro Federal University Hospital, have been engaged in the development of quality control programs applied to radiodiagnostics, one of them concerning gastrointestinal fluoroscopy. Since fluoroscopy examinations normally deal with high doses, they represent an important fraction of public exposure. They deserve special attention and the risks to patients should be considered individually, not only as a population statistics. Another target should be the search for procedures that reduce doses to patients and, therefore, reduce dose to medical staff involved. This work describes steps followed and results obtained in the estimation of doses for patients and physicians. Investigated examinations were esophagography, gastroduodenal seriographic and colon with double contrast media, using conventional equipment with fluorescent screens, carried on by physicians engaged in the first year of medical residence. (authors). 9 refs., 1 fig., 2 tabs

  2. Study of dose profile in TC scanning of cranium

    International Nuclear Information System (INIS)

    Goncalves Junior, R.L.; Oliveira, A.H.; Mourao, A.P.

    2011-01-01

    In this paper it was obtained a dose distribution profile in computerized tomography, when a head simulator object, cylindrical and manufactured in PMMA, were swiped by using the clinical protocol or this device routine. The doses were determined with radiochromic films placed at the four cardinal points and the Center, taking as reference one of object faces. The films were calibrated with pencil ionization chamber in a independent experiment where the obtained doses in the chamber, when a unique central cut or the object were obtained, were confronted with the gray scales on the irradiated films in a similar manner, revealing he factors of conversion mGy.Gray tones -1 which made possible the determination of doses in all the scanning

  3. A systematic study on factors affecting patient dose, 2

    International Nuclear Information System (INIS)

    Otsuka, Akiyoshi; Higashida, Yoshiharu; Utsumi, Hiromoto; Ota, Masaji; Nakanishi, Takashi

    1979-01-01

    In the preceding report, we dealt with the field size and the tube voltage. This paper covers the differences in patient dose due to the focus to film distance (FFD), the patient thickness and whether the grid is used or not. Regarding the FFD, 100 cm is most commonly employed except in X-ray examinations of the chest, but from the viewpoint of the patient dose, this requires special consideration as to whether there is any theoretical basis for it. The patient thickness has a great bearing on the patient dose, but there is an individual difference, and it is almost impossible to change it artificially. However, there has been no detailed report on the relation between the patient thickness and the patient dose, therefore, this report treats of such relationship as well. Concerning the grid, consideration is given to the exposure times (Bucky factor). (author)

  4. Vocabulary Acquisition without Adult Explanations in Repeated Shared Book Reading: An Eye Movement Study

    Science.gov (United States)

    Evans, Mary Ann; Saint-Aubin, Jean

    2013-01-01

    When preschoolers listen to storybooks, are their eye movements related to their vocabulary acquisition in this context? This study addressed this question with 36 four-year-old French-speaking participants by assessing their general receptive vocabulary knowledge and knowledge of low-frequency words in 3 storybooks. These books were read verbatim…

  5. Statistical methods for conducting agreement (comparison of clinical tests) and precision (repeatability or reproducibility) studies in optometry and ophthalmology.

    Science.gov (United States)

    McAlinden, Colm; Khadka, Jyoti; Pesudovs, Konrad

    2011-07-01

    The ever-expanding choice of ocular metrology and imaging equipment has driven research into the validity of their measurements. Consequently, studies of the agreement between two instruments or clinical tests have proliferated in the ophthalmic literature. It is important that researchers apply the appropriate statistical tests in agreement studies. Correlation coefficients are hazardous and should be avoided. The 'limits of agreement' method originally proposed by Altman and Bland in 1983 is the statistical procedure of choice. Its step-by-step use and practical considerations in relation to optometry and ophthalmology are detailed in addition to sample size considerations and statistical approaches to precision (repeatability or reproducibility) estimates. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  6. simple sequence repeat (SSR)

    African Journals Online (AJOL)

    In the present study, 78 mapped simple sequence repeat (SSR) markers representing 11 linkage groups of adzuki bean were evaluated for transferability to mungbean and related Vigna spp. 41 markers amplified characteristic bands in at least one Vigna species. The transferability percentage across the genotypes ranged ...

  7. Diagnosis of cerebral metastases by means of standard doses of Gadobutrol versus a high-dose protocol. Intraindividual evaluation of a phase-II high-dose study

    International Nuclear Information System (INIS)

    Vogl, T.J.; Friebe, C.E.; Balzer, T.; Mack, M.G.; Steiner, S.; Schedel, H.; Pegios, W.; Lanksch, W.; Banzer, D.; Felix, R.

    1995-01-01

    In a clinical phase-II study 20 patients who had been diagnosed as having brain metastases with CT or MRT were studied prospectively with Gadobutrol, a new nonionic, low osmolality contrast agent. Each patient received an initial injection of 0.1 mmol/kg body weight and an additional dose of 0.2 mmol/kg Gadobutrol 10 min later. Spinecho images were obtained before and after the two applications of Gadobutrol. Dynamic scanning (Turbo-FLASH) was performed for 3 min after each injection of the contrast agent. Both quantitative and qualitative data were intraindividually evaluated. The primary tumor was a bronchial carcinoma in 11 cases; in 9 other cases there were different primary tumors. Forty-eight hours after the use of Gadobutrol there were no adverse signs in the clinical examination, vital signs or blood and urine chemistry. Statistical analysis (Friedman test and Wilcoxon test) of the C/N ratios between tumor and white matter, percentage enhancement, and visual assessment rating revealed statistically significant superiority of high-dose Gadobutrol injection in comparison to the standard dose. The percentage enhancement increased on average from 104% after 0.1 mmol/kg to 162% after 0.3 mmol/kg Gadobutrol. Qualitative delineation and contrast of the lesions increased significantly. The use of high-dose Gadobutrol improved the detection of 36 additional lesions in 6 patients. (orig./VHE) [de

  8. Study of incidence and causes of repeated mass miniature radiography of chest

    Energy Technology Data Exchange (ETDEWEB)

    Tandan, S; Bhargava, S K; Sharma, H M; Ved, P K; Singh, Dhan [T.B. Demonstration and Training Centre, Agra (India)

    1976-01-01

    A study has been conducted to find out the retake rate of mass miniature radiography of chest and causes of retake. The rate has been found to be 1.96% and common causes of retake are too light or dark film and movement (motion) other than respiratory. Precautionary measures against these causes should prevent unnecessary exposure of patients to radiation and also ensure economy.

  9. URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

    Science.gov (United States)

    Nasrallah, F.; Feki, M.; Chamari, K.; Omar, S.; Alouane-Trabelsi, L.; Ben Mansour, A.; Kaabachi, N.

    2014-01-01

    Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC) was significantly lower in sprinters than controls (34±30 vs. 74±3 µmol/mmol creatinine, p creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes. PMID:24917689

  10. URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

    Directory of Open Access Journals (Sweden)

    I. Bezrati-Benayed

    2014-07-01

    Full Text Available Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC was significantly lower in sprinters than controls (34±30 vs. 74±3 μmol/mmol creatinine, p<0.05. UC was inversely correlated with body mass (r=-0.34, p<0.01 and lean mass (r=- 0.30, p<0.05, and positively correlated with fat mass (r=0.32, p<0.05. After acute exercise, urinary creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes.

  11. Estimation of the optimal dosing regimen of escitalopram in dogs: A dose occupancy study with [11C]DASB.

    Directory of Open Access Journals (Sweden)

    Olivia Taylor

    Full Text Available Although the favourable characteristics of escitalopram as being the most selective serotonin reuptake inhibitor and having an increased therapeutic efficacy via binding on an additional allosteric binding site of the serotonin transporter, its dosing regimen has not yet been optimized for its use in dogs. This study aimed to estimate the optimal dosing frequency and the required dose for achieving 80% occupancy of the serotonin transporters in the basal ganglia. The dosing frequency was investigated by determining the elimination half-life after a four day oral pre-treatment period with 0.83 mg/kg escitalopram (3 administrations/day and a subsequent i.v. injection 0.83 mg/kg. Blood samples were taken up to 12 hours after i.v. injection and the concentration of escitalopram in plasma was analysed via LC-MSMS. The dose-occupancy relationship was then determined by performing two PET scans in five adult beagles: a baseline PET scan and a second scan after steady state conditions were achieved following oral treatment with a specific dose of escitalopram ranging from 0.5 to 2.5 mg/kg/day. As the elimination half-life was determined to be 6.7 hours a dosing frequency of three administrations a day was proposed for the second part of the study. Further it was opted for a treatment period of four days, which well exceeded the minimum period to achieve steady state conditions. The optimal dosing regimen to achieve 80% occupancy in the basal ganglia and elicit a therapeutic effect, was calculated to be 1.85 mg/kg/day, divided over three administrations. Under several circumstances, such as insufficient response to other SSRIs, concurrent drug intake or in research studies focused on SERT, the use of escitalopram can be preferred over the use of the already for veterinary use registered fluoxetine, however, in case of long-term treatment with escitalopram, regularly cardiac screening is recommended.

  12. Construction and updating of a public events questionnaire for repeated measures longitudinal studies

    Directory of Open Access Journals (Sweden)

    Martha eNoone

    2014-03-01

    Full Text Available Impairments of retrospective memory and cases of retrograde amnesia are often seen in clinical settings. A measure of the proportion of memories retained over a specified time can be useful in clinical situations and public events questionnaires may be valuable in this respect. However, consistency of retention of public events memory has rarely been studied in the same participants. In addition, when used in a research context, public events questionnaires require updating to ensure questions are of equivalent age with respect to when the test is taken. This paper describes an approach to constructing and updating a Public Events Questionnaire (PEQ for use with a sample that is recruited and followed-up over a long time-period. Internal consistency, parallel-form reliability, test-retest reliability and secondary validity analyses were examined for three versions of the PEQ that were updated every six months. Versions 2 and 3 of the questionnaire were reliable across and within versions and for recall and recognition. Change over time was comparable across each version of the PEQ. These results show that PEQs can be regularly updated in a standardised fashion to allow use throughout studies with long recruitment periods.

  13. Magnetic Resonance Spectroscopy in Patients with Insomnia: A Repeated Measurement Study.

    Directory of Open Access Journals (Sweden)

    Kai Spiegelhalder

    Full Text Available Chronic insomnia is one of the most prevalent central nervous system disorders. It is characterized by increased arousal levels, however, the neurobiological causes and correlates of hyperarousal in insomnia remain to be further determined. In the current study, magnetic resonance spectroscopy was used in the morning and evening in a well-characterized sample of 20 primary insomnia patients (12 females; 8 males; 42.7 ± 13.4 years and 20 healthy good sleepers (12 females; 8 males; 44.1 ± 10.6 years. The most important inhibitory and excitatory neurotransmitters of the central nervous system, γ-aminobutyric acid (GABA and glutamate/glutamine (Glx, were assessed in the anterior cingulate cortex (ACC and dorsolateral prefrontal cortex (DLPFC. The primary hypothesis, a diurnal effect on GABA levels in patients with insomnia, could not be confirmed. Moreover, the current results did not support previous findings of altered GABA levels in individuals with insomnia. Exploratory analyses, however, suggested that GABA levels in the ACC may be positively associated with habitual sleep duration, and, thus, reduced GABA levels may be a trait marker of objective sleep disturbances. Moreover, there was a significant GROUP x MEASUREMENT TIME interaction effect on Glx in the DLPFC with increasing Glx levels across the day in the patients but not in the control group. Therefore, Glx levels may reflect hyperarousal at bedtime in those with insomnia. Future confirmatory studies should include larger sample sizes to investigate brain metabolites in different subgroups of insomnia.

  14. Construction and updating of a public events questionnaire for repeated measures longitudinal studies.

    Science.gov (United States)

    Noone, Martha; Semkovska, Maria; Carton, Mary; Dunne, Ross; Horgan, John-Paul; O'Kane, Breige; McLoughlin, Declan M

    2014-01-01

    Impairments of retrospective memory and cases of retrograde amnesia are often seen in clinical settings. A measure of the proportion of memories retained over a specified time can be useful in clinical situations and public events questionnaires may be valuable in this respect. However, consistency of retention of public events memory has rarely been studied in the same participants. In addition, when used in a research context, public events questionnaires require updating to ensure questions are of equivalent age with respect to when the test is taken. This paper describes an approach to constructing and updating a Public Events Questionnaire (PEQ) for use with a sample that is recruited and followed-up over a long time-period. Internal consistency, parallel-form reliability, test-retest reliability, and secondary validity analyses were examined for three versions of the PEQ that were updated every 6 months. Versions 2 and 3 of the questionnaire were reliable across and within versions and for recall and recognition. Change over time was comparable across each version of the PEQ. These results show that PEQs can be regularly updated in a standardized fashion to allow use throughout studies with long recruitment periods.

  15. The effect of image quality, repeated study, and assessment method on anatomy learning.

    Science.gov (United States)

    Fenesi, Barbara; Mackinnon, Chelsea; Cheng, Lucia; Kim, Joseph A; Wainman, Bruce C

    2017-06-01

    The use of two-dimensional (2D) images is consistently used to prepare anatomy students for handling real specimen. This study examined whether the quality of 2D images is a critical component in anatomy learning. The visual clarity and consistency of 2D anatomical images was systematically manipulated to produce low-quality and high-quality images of the human hand and human eye. On day 0, participants learned about each anatomical specimen from paper booklets using either low-quality or high-quality images, and then completed a comprehension test using either 2D images or three-dimensional (3D) cadaveric specimens. On day 1, participants relearned each booklet, and on day 2 participants completed a final comprehension test using either 2D images or 3D cadaveric specimens. The effect of image quality on learning varied according to anatomical content, with high-quality images having a greater effect on improving learning of hand anatomy than eye anatomy (high-quality vs. low-quality for hand anatomy P = 0.018; high-quality vs. low-quality for eye anatomy P = 0.247). Also, the benefit of high-quality images on hand anatomy learning was restricted to performance on short-answer (SA) questions immediately after learning (high-quality vs. low-quality on SA questions P = 0.018), but did not apply to performance on multiple-choice (MC) questions (high-quality vs. low-quality on MC questions P = 0.109) or after participants had an additional learning opportunity (24 hours later) with anatomy content (high vs. low on SA questions P = 0.643). This study underscores the limited impact of image quality on anatomy learning, and questions whether investment in enhancing image quality of learning aids significantly promotes knowledge development. Anat Sci Educ 10: 249-261. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

  16. Does Repeated Ticking Maintain Tic Behavior? An Experimental Study of Eye Blinking in Healthy Individuals

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    Daniel J. V. Beetsma

    2013-01-01

    Full Text Available Tics in Tourette Syndrome (TS are often preceded by 'premonitory urges': annoying feelings or bodily sensations. We hypothesized that, by reducing annoyance of premonitory urges, tic behaviour may be reinforced. In a 2X2 experimental design in healthy participants, we studied the effects of premonitory urges (operationalized as air puffs on the eye and tic behaviour (deliberate eye blinking after a puff or a sound on changes in subjective evaluation of air puffs, and EMG responses on the m. orbicularis oculi. The experimental group with air puffs+ blinking experienced a decrease in subjective annoyance of the air puff, but habituation of the EMG response was blocked and length of EMG response increased. In the control groups (air puffs without instruction to blink, no air puffs, these effects were absent. When extrapolating to the situation in TS patients, these findings suggest that performance of tics is reinforced by reducing the subjective annoyance of premonitory urges, while simultaneously preventing habituation or even inducing sensitisation of the physiological motor response.

  17. Effect of routine repeat transurethral resection for superficial bladder cancer: a long-term observational study.

    Science.gov (United States)

    Grimm, Marc-Oliver; Steinhoff, Christine; Simon, Xenia; Spiegelhalder, Philipp; Ackermann, Rolf; Vogeli, Thomas Alexander

    2003-08-01

    We determined the long-term outcome in patients with superficial bladder cancer (Ta and T1) undergoing routine second transurethral bladder tumor resection (ReTURB) in regard to recurrence and progression. We performed an inception cohort study of 124 consecutive patients with superficial bladder cancer undergoing transurethral resection and routine ReTURB (83) between November 1993 and October 1995 at a German university hospital. Immediately after transurethral resection all lesions were documented on a designed bladder map. ReTURB of the scar from initial resection and other suspicious lesions was performed at a mean of 7 weeks. Patients were followed until recurrence or death, or a minimum of 5 years. Residual tumor was found in 33% of all ReTURB cases, including 27% of Ta and 53% of T1 disease, and in 81% at the initial resection site. Five of the 83 patients underwent radical cystectomy due to ReTURB findings. The estimated risk of recurrence after years 1 to 3 was 18%, 29% and 32%, respectively. After 5 years 63% of the patients undergoing ReTURB were still disease-free (mean recurrence-free survival 62 months, median 87). Progression to muscle invasive disease was observed in only 2 patients (3%) after a mean observation of 61 months. These data suggest a favorable outcome regarding recurrence and progression in patients with superficial bladder cancer who undergo ReTURB. ReTURB is suggested at least in those at high risk when bladder preservation is intended.

  18. Breath acidification in adolescent runners exposed to atmospheric pollution: A prospective, repeated measures observational study

    Directory of Open Access Journals (Sweden)

    Van Sickle David

    2008-03-01

    Full Text Available Abstract Background Vigorous outdoors exercise during an episode of air pollution might cause airway inflammation. The purpose of this study was to examine the effects of vigorous outdoor exercise during peak smog season on breath pH, a biomarker of airway inflammation, in adolescent athletes. Methods We measured breath pH both pre- and post-exercise on ten days during peak smog season in 16 high school athletes engaged in daily long-distance running in a downwind suburb of Atlanta. The association of post-exercise breath pH with ambient ozone and particulate matter concentrations was tested with linear regression. Results We collected 144 pre-exercise and 146 post-exercise breath samples from 16 runners (mean age 14.9 years, 56% male. Median pre-exercise breath pH was 7.58 (interquartile range: 6.90 to 7.86 and did not change significantly after exercise. We observed no significant association between ambient ozone or particulate matter and post-exercise breath pH. However both pre- and post-exercise breath pH were strikingly low in these athletes when compared to a control sample of 14 relatively sedentary healthy adults and to published values of breath pH in healthy subjects. Conclusion Although we did not observe an acute effect of air pollution exposure during exercise on breath pH, breath pH was surprisingly low in this sample of otherwise healthy long-distance runners. We speculate that repetitive vigorous exercise may induce airway acidification.

  19. Understanding how adherence goals promote adherence behaviours: a repeated measure observational study with HIV seropositive patients

    Directory of Open Access Journals (Sweden)

    Jones Gareth

    2012-08-01

    behaviours over and above the effects of the behaviour-specific thinking and ii the relationship between adherence to exercise and to medical treatment is stronger among those with more favourable views about the goal. Results from this study should identify the key contributing factors to inform subsequent adherence research and afford a more streamlined assessment matrix. The project also aims to inform patient care practices. UK Clinical Research Network registration number UKCRN 7842.

  20. Comparison in the calculation of committed effective dose using the ICRP 30 and ICRP 60 models for a repeated incorporation by inhalation of I-125; Comparacion en el calculo de la dosis efectiva comprometida usando los modelos del ICRP 30 y del ICRP 60 para una incorporacion repetida por inhalacion de I-125

    Energy Technology Data Exchange (ETDEWEB)

    Carreno P, A.L.; Cortes C, A. [CNSNS, Dr. Barragan 779, Col. Narvarte, Mexico D.F. (Mexico); Alonso V, G.; Serrano P, F. [IPN, Edificio de Fisica Avanzada Zacatenco, 07300 Mexico D.F. (Mexico)

    2005-07-01

    Presently work, a comparison in the calculation of committed effective dose using the models of the ICRP 30 and those of the ICRP 60 for the analysis of internal dose due to repeated incorporation of I-125 is shown. The estimations of incorporated activity are obtained starting from the proportionate data for an exercise of inter comparison, with which it should be determined the internal dose later on. For to estimate the initial activity incorporated by repeated dose was assumed that this it was given through of multiple individual incorporations which happened in the middle points of the monitoring periods. The results using the models of the ICRP 30 and of the ICRP 60 are compared and the causes of the differences are analyzed. (Author)

  1. Study on fine quartz pre-dose techniques

    International Nuclear Information System (INIS)

    Leung, P.L.; Stokes, M.J.; Wang Weida; Xia Junding

    1996-01-01

    When using the pre-dose technique in ceramic dating, it is essential to add a calibration dose and to eliminate the background dose. For doing this measurement the sample requires multiple activation following multiple administration of a test dose to induce simulated 'ancient' thermoluminescence (TL). However, the procedures introduce many factors that are difficultly corrected. The authors compare existing two kinds of measurement procedures and proposes a new procedure involving single activation following a single test dose administration. An experiment using the single activation procedure is carried out with natural fine quartz where the results obtained exhibit only 0.07 relative error. It appears that this new procedure increases the precision of the ancient TL measurement by about 0.04 and 0.11 over those of existing two kinds of procedures. In addition this method can give realistic values in TL dating for relatively 'young' samples aged tens to hundreds of years where the standard high temperature TL method is relatively insensitive

  2. What can be learned from epidemiologic studies of persons exposed to low doses of radiation?

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1993-04-01

    The main objective of radiation risk assessment is to determine the risk of various adverse health effects associated with exposure to low doses and low dose rates. Extrapolation of risks from studies of persons exposed at high doses (generally exceeding 1 Sv) and dose rates has been the primary approach used to achieve this objective. The study of Japanese atomic bomb survivors in Hiroshima and Nagasaki has played an especially important role in risk assessment efforts. A direct assessment of the dose-response function based on studies of persons exposed at low doses and dose rates is obviously desirable. This paper focuses on the potential of both current and future nuclear workers studies for investigating the dose-response functions at low doses, and also discusses analyses making use of the low dose portion of the atomic bomb survivor data. Difficulties in using these data are the statistical imprecision of estimated dose-response parameters, and potential bias resulting from confounding factors and from uncertainties in dose estimates

  3. Prophylactic CNS therapy in childhood leukemia. Randomized controlled study of high-dose intravenous methotrexate and cranial irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Takashi; Hiyoshi, Yasuhiko [Kurume Univ., Fukuoka (Japan). School of Medicine; Fujimoto, Takeo

    1982-12-01

    This study was designed to evaluate the efficacy of CNS-prophylaxis with high-dose methotrexate (MTX). Seventy children with previously untreated acute lymphoblastic leukemia (ALL) entered to this study between July 1978 and December 1980. According to initial white blood count (WBC), they were stratified to induce remission with; vincristine and prednine in low initial WBC ( lt 25,000/mm/sup 3/) group and these two agents plus adriamycin in high initial WBC ( gt 25,000/mm/sup 3/) group. After inducing remission, 62 children who achieved CR, received different CNS-prophlaxis; using a regimen of three doses of weekly high-dose MTX (1,000 mg/m/sup 2/) 6-hour infusion, which was repeated every 12 weeks-Group A (n = 14); high-dose MTX followed by 2400 rad cranial irradiation plus three doses of i.t. MT X-Group B (n = 15), 2400 rad cranial irradiation plus three doses of i.t. MTX-Group C (n = 16), and in 17 patients with high initial WBC, same as in Group A-Group D (n = 17). During an intravenous 6-h infusion of MTX at a dose of 1,000 mg/m/sup 2/, the CSF concentration of MTX rose to 2.3 +- 2.4 x 10/sup -6/M after initiation of infusion and remained in 10/sup -7/ M level for 48 hours. CNS-leukemia terminated complete remission in one of 14 children in Group A, two of 15 in Group B, two of 16 in Group C and two of 17 in Group D. The cumulative incidence of CNS-leukemia at 20 months calculated by the technique of Kaplan and Meier was 0% in Group A, 18.1% in Group B, 7.1% in Group C and 50.8% in Group D. There was no statistical difference among Groups A, B and C. These data suggested that CNS-prophylaxis with high-dose intravenous MTX was effective as well as 2400 rad cranial irradiation plus three doses of i.t. MTX in childhood ALL with low initial WBC.

  4. [A case-control study of factors associated with repeat teen pregnancy based on a sample from a university maternity hospital].

    Science.gov (United States)

    Silva, Andréa de Albuquerque Arruda; Coutinho, Isabela C; Katz, Leila; Souza, Alex Sandro Rolland

    2013-03-01

    Repeat teen pregnancy is a frequent issue and is considered an aggravating factor for increased maternal and fetal morbidity and social problems. The aim of the study was to identify factors associated with repeat teen pregnancy. A case-control study was conducted in 90 postpartum adolescents with more than one pregnancy (cases) and 90 adult women with a history of only one pregnancy during adolescence (controls). Statistical analysis used hierarchical logistic regression with 5% significance. Early sexual initiation (pregnancy (pregnancy, while partner change was inversely associated. Repeat teen pregnancy was mainly associated with reproductive and socioeconomic factors. Partner change appeared as a protective factor. Measures should be adopted during the postpartum period of teenage mothers in order to avoid repeat pregnancy.

  5. Study on cellular survival adaptive response induced by low dose irradiation of 153Sm

    International Nuclear Information System (INIS)

    Zhu Shoupeng; Xiao Dong

    1999-01-01

    The present study engages in determining whether low dose irradiation of 153 Sm could cut down the responsiveness of cellular survival to subsequent high dose exposure of 153 Sm so as to make an inquiry into approach the protective action of adaptive response by second irradiation of 153 Sm. Experimental results indicate that for inductive low dose of radionuclide 153 Sm 3.7 kBq/ml irradiated beforehand to cells has obvious resistant effect in succession after high dose irradiation of 153 Sm 3.7 x 10 2 kBq/ml was observed. Cells exposed to low dose irradiation of 153 Sm become adapted and therefore the subsequent cellular survival rate induced by high dose of 153 Sm is sufficiently higher than high dose of 153 Sm merely. It is evident that cellular survival adaptive response could be induced by pure low dose irradiation of 153 Sm only

  6. Public involvement in the dose reconstruction study: the colorado story

    International Nuclear Information System (INIS)

    Morin, Norma C.; Lockhart, Ann J.

    2000-01-01

    Public involvement was a critical component for building awareness, trust, and credibility for the dose reconstruction study for the Rocky Flats Nuclear Weapons Facility in Colorado. The research team developed a process to inform, involve, and encourage public participation over the nine-year study period. Key affected and interested groups with a legitimate stake in the study were identified and invited to identify concerns and offer suggestions for the study. In many cases, the public actually provided direction for the research. Many issues were studied more in-depth as result of public concern. Proactive community outreach was undertaken; quarterly public meetings and workshops were held to inform the public about the study's progress and to hear their comments. Quarterly newsletters were mailed to stake holders. A speaker's bureau was established and more than 50 presentations were made to 1,500 community members in various civic, business, neighborhood, and technical groups. Fact sheets, citizen summaries of technical reports, technical topic papers, and a video were developed to provide a complete overview of the studies and the findings at the conclusion of the project. The video was provided to local cable television stations, and publications were taken to local libraries. A web site was developed to allow the public to readily access information and to order technical reports. Public comments on draft technical reports were solicited; questions and concerns were addressed and investigated. The staff answered citizen calls, and the research team responded in writing to more than 200 issues raised by very concerned citizens. In addition, a citizen's group was formed in 1992 to conduct an independent study of plutonium levels found in soil samples collected around Rocky Flats. Made up of homeowners, public interest groups, local health departments, interested citizens, and Health Advisory Panel members, the committee arranged for sampling and analysis of

  7. Entyvio lengthen dose-interval study: lengthening vedolizumab dose interval and the risk of clinical relapse in inflammatory bowel disease.

    Science.gov (United States)

    Chan, Webber; Lynch, Nicole; Bampton, Peter; Chang, Jeff; Chung, Alvin; Florin, Timothy; Hetzel, David J; Jakobovits, Simon; Moore, Gregory; Pavli, Paul; Radford-Smith, Graham; Thin, Lena; Baraty, Brandon; Haifer, Craig; Yau, Yunki; Leong, Rupert W L

    2018-07-01

    Vedolizumab (VDZ), an α4β7 anti-integrin antibody, is efficacious in the induction and maintenance of remission in ulcerative colitis (UC) and Crohn's disease (CD). In the GEMINI long-term safety study, enrolled patients received 4-weekly VDZ. Upon completion, patients were switched to 8-weekly VDZ in Australia. The clinical success rate of treatment de-escalation for patients in remission on VDZ has not been described previously. To determine the proportion of patients who relapsed after switching from 4 to 8-weekly VDZ, the mean time to relapse, and the recapture rate when switching back to 8-weekly dosing. This was a retrospective, observational, multicenter study of patients previously recruited into GEMINI long-term safety in Australia. Data on the demographics and biochemical findings were collected. There were 34 patients [23 men, mean age 49.1 (±13.1) years] and their mean disease duration was 17.6 (±8.5) years. The mean 4-weekly VDZ infusion duration was 286.5 (±48.8) weeks. A total of five (15%) patients relapsed on dose-interval increase (4/17 UC, 1/17 CD) at a median duration from dose interval lengthening to flare of 14 weeks (interquartile range=6-25). Eighty percent (4/5) of patients re-entered remission following dose-interval decrease back to 4-weekly. No clinical predictors of relapse could be determined because of the small cohort size. The risk of patients relapsing when switching from 4 to 8-weekly VDZ ∼15% and is similar between CD and UC. Dose-interval decrease recaptures 80% of patients who relapsed. Therapeutic drug monitoring of VDZ may be of clinical relevance.

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

    Directory of Open Access Journals (Sweden)

    Salah H. Al Janaby

    2017-02-01

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

  9. Chinese herbal dose in ancient and modern times: a comparative study.

    Science.gov (United States)

    He, Shimin

    2013-04-01

    Appropriate dose guarantees Chinese herb's safety and effectiveness. There are adult dose criteria for Chinese herbs in decoction in the Pharmacopoeia of the People's Republic of China (2010 Edition) at present. But Chinese herbs have been frequently used in much higher doses than the dose criteria. This study has been conducted to test the dependability of the dose criteria. Twenty Chinese herbs were selected as representatives and their adult doses in decoction in Bei Ji Qian Jin Yao Fang, a famous ancient literature, have been reviewed and compared with those in the Pharmacopoeia of the People's Republic of China (2010 Edition). The adult dose criteria for all these 20 Chinese herbs in the Pharmacopoeia of the People's Republic of China (2010 Edition) haven't covered those in Bei Ji Qian Jin Yao Fang. Furthermore, maximal adult doses in the dose criteria are much lower than those in Bei Ji Qian Jin Yao Fang. The dose criteria in the Pharmacopoeia of the People's Republic of China (2010 Edition) are not comprehensive enough. Studying ancient literatures is an effective method to gain precious Chinese herbs' dose data and helps for new dose criteria's establishment in the future.

  10. Analysis and planning of dose-finding studies with active control

    International Nuclear Information System (INIS)

    Helms, Hans-Joachim

    2014-01-01

    In the clinical development of radiopharmaceuticals the dose finding plays an important role. The contribution is focused on the evaluation and planning of dose finding studies with active control. It is of primary interest to find the lowest dose that yields the same efficacy as the active control. Besides the target dose confidence intervals are of importance to describe the quality of the target dose estimation. The calculation of case numbers and the determination of the dose steps to be studied are challenging under practical conditions. The contribution covers the demonstration of the statistical model the parameter estimation and the asymptotic properties based on maximum likelihood theory, the spline-based evaluation of nonlinear dose finding studies with active control and the planning of design and number of cases.

  11. A comparative study on pathological features of transgenic rat lines expressing either three or four repeat misfolded tau.

    Science.gov (United States)

    Valachova, Bernadeta; Brezovakova, Veronika; Bugos, Ondrej; Jadhav, Santosh; Smolek, Tomas; Novak, Petr; Zilka, Norbert

    2018-08-01

    Human tauopathies represent a heterogeneous group of neurodegenerative disorders characterized by distinct clinical features, typical histopathological structures, and defined ratio(s) of three-repeat and four-repeat tau isoforms within pathological aggregates. How the optional microtubule-binding repeat of tau influences this differentiation of pathologies is understudied. We have previously generated and characterized transgenic rodent models expressing human truncated tau aa151-391 with either three (SHR24) or four microtubule-binding repeats (SHR72). Here, we compare the behavioral and neuropathological hallmarks of these two transgenic lines using a battery of tests for sensorimotor, cognitive, and neurological functions over the age range of 3.5-15 months. Progression of sensorimotor and neurological deficits was similar in both transgenic lines; however, the lifespan of transgenic line SHR72 expressing truncated four-repeat tau was markedly shorter than SHR24. Moreover, the expression of three or four-repeat tau induced distinct neurofibrillary pathology in these lines. Transgenic lines displayed different distribution of tau pathology and different type of neurofibrillary tangles. Our results suggest that three- and four-repeat isoforms of tau may display different modes of action in the diseased brain. © 2018 Wiley Periodicals, Inc.

  12. Laparoscopic cholecystectomy under spinal anesthesia: comparative study between conventional-dose and low-dose hyperbaric bupivacaine

    Directory of Open Access Journals (Sweden)

    Imbelloni LE

    2011-10-01

    Full Text Available Luiz Eduardo Imbelloni1, Raphael Sant'Anna2, Marcos Fornasari2, José Carlos Fialho21Department of Anesthesiology, Faculty of Medecine Nova Esperança, Hospital de Mangabeira, João Pessoa, 2Hospital Rio Laranjeiras, Rio de Janeiro, BrazilBackground: Laparoscopic cholecystectomy has the advantages of causing less postoperative pain and requiring a short hospital stay, and therefore is the treatment of choice for cholelithiasis. This study was designed to compare spinal anesthesia using hyperbaric bupivacaine given as a conventional dose by lumbar puncture or as a low-dose by thoracic puncture.Methods: A total of 140 patients with symptomatic gallstone disease were randomized to undergo laparoscopic cholecystectomy with low-pressure CO2 pneumoperitoneum under spinal anesthesia using either conventional lumbar spinal anesthesia (hyperbaric bupivacaine 15 mg and fentanyl 20 mg or low-dose thoracic spinal anesthesia (hyperbaric bupivacaine 7.5 mg and fentanyl 20 µg. Intraoperative parameters, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two treatment groups.Results: All procedures were completed under spinal anesthesia, with no cases needing conversion to general anesthesia. Values for time for block to reach the T3 dermatomal level, duration of motor and sensory block, and hypotensive events were significantly lower with low-dose bupivacaine. Postoperative pain was higher for low-dose hyperbaric bupivacaine at 6 and 12 hours. All patients were discharged after 24 hours. Follow-up 1 week postoperatively showed all patients to be satisfied and to be keen advocates of spinal anesthesia.Conclusion: Laparoscopic cholecystectomy can be performed successfully under spinal anesthesia. A small dose of hyperbaric bupivacaine 7.5 mg and 20 µg fentanyl provides adequate spinal anesthesia for laparoscopy and, in comparison with hyperbaric bupivacaine 15% and fentanyl 20 µg, causes markedly

  13. Study of dose effect relationship at low doses for non quantitative reactions of skin intestinal mucosa and lung

    International Nuclear Information System (INIS)

    Dutreix, J.; Wambersie, A.

    1977-01-01

    Most of the biological reactions observed in animal experiments or in clinical studies are non quantitative and they only allow assessing an inequality between the effects produced by different irradiations. The method used in non quantitative studies is actually based on the relative contribution of irreparable events and reparable to the cell killing. It provides for the cell population involved in non quantitative biological effects some data which can be expressed in term of a cell survival curve. Such data can be useful in Radiation therapy particularly for maximizing the difference between biological effects by a proper choice of the fraction size. The initial part of the cell survival curve, within the range of doses actually used appears to be a straight exponential. This should allow the extrapolation to very low doses in the range of interest to Radiation Protection

  14. A study of radiation exposure dose in young dental patients

    International Nuclear Information System (INIS)

    Hatakeyama, Atsushi

    1983-01-01

    In order to clarify the trend in dental radiography for young patients up to 18 years old and the accompanying radiation exposures, surveys were made at Fukuoka Dental College Hospital and thirty-five dental offices in Fukuoka city and Kitakyushu city. Each kind of radiography increased in average number with age and 16-18 group was given 4.60 times of radiography of one kind or another in the clinic of college hospital. In the dental offices, the number of radiography taken was about one-fourth that of the clinic of college hospital. Although exposure dose varies with exposure factors, distance and angle of exposure, in addition to time factor, were found to affect doses subtly. In the clinic of college hospital the average of estimated doses to organs per person per year were 105.4 mrad (25.2 mrad for 5-year-old children) in the salivary gland, 55.9 mrad (18.9 mrad for 5-year-old) in the thyroid gland, 52.1 mrad (15.0 mrad for 5-year-old) in the lens of the eye and 52.2 mrad (8.7 mrad for 5-year-old) in the sella turcica. In the dental offices, the same average of estimated doses to organs were 40.5 mrad (7.4 mrad for 5-year-old) in the salivary gland, 17.4 mrad (8.0 mrad for 5-year-old) in the thyroid gland, 12.2 mrad (6.1 mrad for 5-year-old) in the lens of eye and 13.1 mrad (1.3 mrad for 5-year-old) in the sella turcica. In all kinds of radiograpy, the estimated doses in genital glands were in μrad. In the dental offices, both the percentage of young patients to all patients and the radiographing rate were lower as compared with those in the clinic of college hospital. The estimated doses were also lower at one-half to one-fifth and those by age and by organ were found to be one-tenth or lower. (J.P.N.)

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  16. Study of dose calculation and beam parameters optimization with genetic algorithm in IMRT

    International Nuclear Information System (INIS)

    Chen Chaomin; Tang Mutao; Zhou Linghong; Lv Qingwen; Wang Zhuoyu; Chen Guangjie

    2006-01-01

    Objective: To study the construction of dose calculation model and the method of automatic beam parameters selection in IMRT. Methods: The three-dimension convolution dose calculation model of photon was constructed with the methods of Fast Fourier Transform. The objective function based on dose constrain was used to evaluate the fitness of individuals. The beam weights were optimized with genetic algorithm. Results: After 100 iterative analyses, the treatment planning system produced highly conformal and homogeneous dose distributions. Conclusion: the throe-dimension convolution dose calculation model of photon gave more accurate results than the conventional models; genetic algorithm is valid and efficient in IMRT beam parameters optimization. (authors)

  17. Expansion of protein domain repeats.

    Directory of Open Access Journals (Sweden)

    Asa K Björklund

    2006-08-01

    Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

  18. Brachial artery responses to ambient pollution, temperature, and humidity in people with type 2 diabetes: a repeated-measures study.

    Science.gov (United States)

    Zanobetti, Antonella; Luttmann-Gibson, Heike; Horton, Edward S; Cohen, Allison; Coull, Brent A; Hoffmann, Barbara; Schwartz, Joel D; Mittleman, Murray A; Li, Yongsheng; Stone, Peter H; de Souza, Celine; Lamparello, Brooke; Koutrakis, Petros; Gold, Diane R

    2014-03-01

    Extreme weather and air pollution are associated with increased cardiovascular risk in people with diabetes. In a population with diabetes, we conducted a novel assessment of vascular brachial artery responses both to ambient pollution and to weather (temperature and water vapor pressure, a measure of humidity). Sixty-four 49- to 85-year-old Boston residents with type 2 diabetes completed up to five study visits (279 repeated measures). Brachial artery diameter (BAD) was measured by ultrasound before and after brachial artery occlusion [i.e., flow-mediated dilation (FMD)] and before and after nitroglycerin-mediated dilation (NMD). Ambient concentrations of fine particulate mass (PM2.5), black carbon (BC), organic carbon (OC), elemental carbon, particle number, and sulfate were measured at our monitoring site; ambient concentrations of carbon monoxide, nitrogen dioxide, and ozone were obtained from state monitors. Particle exposure in the home and during each trip to the clinic (home/trip exposure) was measured continuously and as a 5-day integrated sample. We used linear models with fixed effects for participants, adjusting for date, season, temperature, and water vapor pressure on the day of each visit, to estimate associations between our outcomes and interquartile range increases in exposure. Baseline BAD was negatively associated with particle pollution, including home/trip-integrated BC (-0.02 mm; 95% CI: -0.04, -0.003, for a 0.28 μg/m3 increase in BC), OC (-0.08 mm; 95% CI: -0.14, -0.03, for a 1.61 μg/m3 increase) as well as PM2.5, 5-day average ambient PM2.5, and BC. BAD was positively associated with ambient temperature and water vapor pressure. However, exposures were not consistently associated with FMD or NMD. Brachial artery diameter, a predictor of cardiovascular risk, decreased in association with particle pollution and increased in association with ambient temperature in our study population of adults with type 2 diabetes. Zanobetti A, Luttmann

  19. Irradiation preservation study on Beijing roast duck by low dose

    Energy Technology Data Exchange (ETDEWEB)

    Weiguo, Wang; Yongbao, Gu; Fengmei, Li [Beijing Normal Univ., BJ (China). Inst. of Low Energy Nuclear Physics; and others

    1989-02-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as {gamma}-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome.

  20. Irradiation preservation study on Beijing roast duck by low dose

    International Nuclear Information System (INIS)

    Wang Weiguo; Gu Yongbao; Li Fengmei

    1989-01-01

    The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as γ-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome

  1. Studies on chronic effects of lower dose level irradiation

    International Nuclear Information System (INIS)

    Yun, T.G.; Yun, Y.S.; Yun, M.S.

    1980-01-01

    This experiment is being carried out to elucidate the chronic effects of Co 60 (γ-ray) - low doses irradiation on JCR mice at 3rd week, 6th week, and 5th month after their birth. Experimental mice at 3rd week of age have been irradiated with Co 60 - 60mR weekly, Co 60 - 500mR weekly and Co 60 - 61R biweekly at the dose rate of 60mR per second for 23 weeks until now. Co 60 - 61R irradiated mice were subdivided into Co 60 - alone group and Co 60 combined with red ginseng extracts group. In their survivor's rate and their body weight etc., no significant differences between control groups and test groups in these experimental mice. Experimented mice at 6 weeks and 5 months of age are also being irradiated with Co 60 in the same doses as the above for 14 weeks and 8 weeks until present. In these experimental groups, there are also no significant differences between control groups and experimental groups in their survivor's rate and their body weight

  2. An IMRT dose distribution study using commercial verification software

    International Nuclear Information System (INIS)

    Grace, M.; Liu, G.; Fernando, W.; Rykers, K.

    2004-01-01

    Full text: The introduction of IMRT requires users to confirm that the isodose distributions and relative doses calculated by their planning system match the doses delivered by their linear accelerators. To this end the commercially available software, VeriSoft TM (PTW-Freiburg, Germany) was trialled to determine if the tools and functions it offered would be of benefit to this process. The CMS Xio (Computer Medical System) treatment planning system was used to generate IMRT plans that were delivered with an upgraded Elekta SL15 linac. Kodak EDR2 film sandwiched in RW3 solid water (PTW-Freiburg, Germany) was used to measure the IMRT fields delivered with 6 MV photons. The isodose and profiles measured with the film generally agreed to within ± 3% or ± 3 mm with the planned doses, in some regions (outside the IMRT field) the match fell to within ± 5%. The isodose distributions of the planning system and the film could be compared on screen and allows for electronic records of the comparison to be kept if so desired. The features and versatility of this software has been of benefit to our IMRT QA program. Furthermore, the VeriSoft TM software allows for quick and accurate, automated planar film analysis.Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  3. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  4. Risk factors for complications in donors at first and repeat whole blood donation: a cohort study with assessment of the impact on donor return.

    Science.gov (United States)

    Wiersum-Osselton, Johanna C; Marijt-van der Kreek, Tanneke; Brand, Anneke; Veldhuizen, Ingrid; van der Bom, Johanna G; de Kort, Wim

    2014-01-01

    First-time donation is among recognised risk factors for vasovagal reactions to blood donation and reactions are known to reduce donor return. We assessed associations between potential risk factors and vasovagal reactions and needle-related complications in first-time whole blood donation in comparison to repeat donation and analysed the impact of complications on donor return. We performed a cohort study on whole blood donations in The Netherlands from 1/1/2010 to 31/12/2010 using data extracted from the blood service information system. Donation data up to 31/12/2011 were used to ascertain donor return. In 2010 28,786 donors made first whole blood donations and there were 522,958 repeat donations. Vasovagal reactions occurred in 3.9% of first donations by males and 3.5% of first donations by females compared to in 0.2% and 0.6%, respectively, of repeat donations. Associations of vasovagal reactions with other factors including age, body weight, systolic and diastolic blood pressure were similar in first-time and repeat donors. Needle-related complications occurred in 0.2% of male and 0.5% of female first-time donations and in 0.1% and 0.3%, respectively, of repeat donations. Among first-time donors, the return rate within 1 year was 82% following an uncomplicated first donation, but 55% and 61% following vasovagal reactions and needle-related complications, respectively; the corresponding percentages among repeat donors were 86%, 58% and 82%. Among first-time donors, females suffered less than males from vasovagal reactions. Other risk factors had similar associations among first-time and repeat donors. Vasovagal reactions and needle-related complications in both first-time and repeat donors are followed by reduced donor return.

  5. First Worldwide Proficiency Study on Variable-Number Tandem-Repeat Typing of Mycobacterium tuberculosis Complex Strains

    Science.gov (United States)

    de Beer, Jessica L.; Kremer, Kristin; Ködmön, Csaba; Supply, Philip

    2012-01-01

    Although variable-number tandem-repeat (VNTR) typing has gained recognition as the new standard for the DNA fingerprinting of Mycobacterium tuberculosis complex (MTBC) isolates, external quality control programs have not yet been developed. Therefore, we organized the first multicenter proficiency study on 24-locus VNTR typing. Sets of 30 DNAs of MTBC strains, including 10 duplicate DNA samples, were distributed among 37 participating laboratories in 30 different countries worldwide. Twenty-four laboratories used an in-house-adapted method with fragment sizing by gel electrophoresis or an automated DNA analyzer, nine laboratories used a commercially available kit, and four laboratories used other methods. The intra- and interlaboratory reproducibilities of VNTR typing varied from 0% to 100%, with averages of 72% and 60%, respectively. Twenty of the 37 laboratories failed to amplify particular VNTR loci; if these missing results were ignored, the number of laboratories with 100% interlaboratory reproducibility increased from 1 to 5. The average interlaboratory reproducibility of VNTR typing using a commercial kit was better (88%) than that of in-house-adapted methods using a DNA analyzer (70%) or gel electrophoresis (50%). Eleven laboratories using in-house-adapted manual typing or automated typing scored inter- and intralaboratory reproducibilities of 80% or higher, which suggests that these approaches can be used in a reliable way. In conclusion, this first multicenter study has documented the worldwide quality of VNTR typing of MTBC strains and highlights the importance of international quality control to improve genotyping in the future. PMID:22170917

  6. What is desirable and feasible in dose reconstruction for application in epidemiological studies?

    International Nuclear Information System (INIS)

    Bouville, A.; Anspaugh, L.; Beebe, G.W.

    1996-01-01

    Formal epidemiologic studies are intended to increase scientific knowledge about the quantitative risk that is associated with radiation exposure. Dosimetric data are needed for such studies. What dosimetric data are desirable? Doses are needed for a large number of people with a large gradation of radiation exposures in order to ensure a sufficient power for the epidemiological study. The characteristics of the desirable doses are, in some respects, different from those calculated for radiation protection purposes. The desirable data are: absorbed doses to the individual organs or tissues of interest, instead of effective doses; absorbed doses delivered over limited time periods, instead of committed doses; doses specific to the individuals that are subjects in the epidemiological studies, instead of average doses over population groups; and very accurate and precise doses. What dosimetric data are feasible? Most of the characteristics of the desirable dosimetric data are usually achievable. However, uncertainties can be fairly large and estimated with a large degree of subjectivity. Also, for practical reasons, it may not be feasible to estimate individual doses for all subjects

  7. Studies on reduction of dosimeter used in the product dose mapping process at Sinagama Plant

    International Nuclear Information System (INIS)

    Sofian Ibrahim; Syuhada Ramli; Cosmos George; Zarina Mohd Nor; Kamarudin Buyong; Shahidan Yob; Nor Ishadi Ismail; Mohd Sidek Othman; Ahsanulkhaliqin Abdul Wahab; Mohd Khairul Azfar Ramli

    2012-01-01

    Product dose mapping is the determination of the best product loading configuration which will be used during routine sterilization. In product dose mapping, dosimeters are placed throughout products at strategic locations to determine the zones of minimum and maximum dose. On previous Sinagama's product dose mapping method, a total of 240 unit's ceric-cerous dosimeter been used for a tote. Based on the data obtained from Irradiator Dose Mapping Report in 2004 and data from recent studies, the number of dosimeter to be used in product dose mapping can be reduced to 28 units without sacrificing precision and accuracy of the dose mapping results. This also led changes of the placing dosimeter method from Plane system to Coordinate system. Reduction of 88 % on dosimeters usage will directly reduce the cost of expenses on dosimeter, time and labor. (author)

  8. (In)Consistencies in Responses to Sodium Bicarbonate Supplementation: A Randomised, Repeated Measures, Counterbalanced and Double-Blind Study.

    Science.gov (United States)

    Froio de Araujo Dias, Gabriela; da Eira Silva, Vinicius; de Salles Painelli, Vitor; Sale, Craig; Giannini Artioli, Guilherme; Gualano, Bruno; Saunders, Bryan

    2015-01-01

    Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB). 15 physically active males (age 25±4 y; body mass 76.0±7.3 kg; height 1.77±0.05 m) completed six cycling capacity tests at 110% of maximum power output (CCT110%) following ingestion of either 0.3 g∙kg-1BM of SB (4 trials) or placebo (PL, 2 trials). Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD) was recorded as the exercise outcome. SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤ 0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05). Blood lactate was elevated following exercise in all trials (p ≤ 0.001), and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05), although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none. The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation. ClinicalTrials.gov NCT02474628.

  9. Can father inclusive practice reduce paternal postnatal anxiety? A repeated measures cohort study using the hospital anxiety and depression scale

    Directory of Open Access Journals (Sweden)

    Tohotoa Jenny

    2012-07-01

    Full Text Available Abstract Background Perinatal research on anxiety and depression has primarily focused on mothers. We have limited knowledge of fathers’ anxiety during the perinatal period yet there is evidence that the parenting capacity of a person can be compromised by anxiety and depression. The purpose of this paper is to identify the impact of a father inclusive intervention on perinatal anxiety and depression. The prime focus of the intervention was to provide education and support to fathers of breastfeeding partners with the aim of increasing both initiation and duration of breastfeeding. Methods A repeated measures cohort study was conducted during a RCT that was implemented across eight public maternity hospitals in Perth, Western Australia between May 2008 and June 2009. A baseline questionnaire which included the Hospital Anxiety and Depression Scale (HADS was administered to all participants on the first night of their hospital based antenatal education program and was repeated at six weeks postnatal. SPSS version 17 was used for reporting descriptive results. Results The mean anxiety levels at baseline for the fathers in the intervention group (n=289 and control group (n=244 were 4.58 and 4.22 respectively. At 6 weeks postnatal (only matched pairs, intervention and control group were 3.93 and 3.79. More intervention group fathers self-rated less anxiety compared to the fathers in the control group from baseline to post test (p=0.048. Depression scores for intervention fathers at baseline (mean =1.09 and at six weeks (mean=1.09 were very similar to fathers in the control group at baseline (mean=1.11 and at six weeks (mean =1.07 with no significant changes. Conclusions Both intervention and control group fathers experienced some anxiety prior to the birth of their baby, but this was rapidly reduced at six weeks. Paternal anxiety is common to new fathers and providing them with information and strategies for problem-solving can increase their

  10. (InConsistencies in Responses to Sodium Bicarbonate Supplementation: A Randomised, Repeated Measures, Counterbalanced and Double-Blind Study.

    Directory of Open Access Journals (Sweden)

    Gabriela Froio de Araujo Dias

    Full Text Available Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB.15 physically active males (age 25±4 y; body mass 76.0±7.3 kg; height 1.77±0.05 m completed six cycling capacity tests at 110% of maximum power output (CCT110% following ingestion of either 0.3 g∙kg-1BM of SB (4 trials or placebo (PL, 2 trials. Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD was recorded as the exercise outcome.SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤ 0.001; absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05. Blood lactate was elevated following exercise in all trials (p ≤ 0.001, and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05, although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none.The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation.ClinicalTrials.gov NCT02474628.

  11. Development of a radiopharmaceutical dose calculator for pediatric patients undergoing diagnostic nuclear medicine studies

    International Nuclear Information System (INIS)

    Pandey, Anil Kumar; Sharma, Sanjay Kumar; Sharma, Punit; Gupta, Priyanka; Kumar, Rakesh

    2013-01-01

    It is important to ensure that as low as reasonably achievable (ALARA) concept during the radiopharmaceutical (RPH) dose administration in pediatric patients. Several methods have been suggested over the years for the calculation of individualized RPH dose, sometimes requiring complex calculations and large variability exists for administered dose in children. The aim of the present study was to develop a software application that can calculate and store RPH dose along with patient record. We reviewed the literature to select the dose formula and used Microsoft Access (a software package) to develop this application. We used the Microsoft Excel to verify the accurate execution of the dose formula. The manual and computer time using this program required for calculating the RPH dose were compared. The developed application calculates RPH dose for pediatric patients based on European Association of Nuclear Medicine dose card, weight based, body surface area based, Clark, Solomon Fried, Young and Webster's formula. It is password protected to prevent the accidental damage and stores the complete record of patients that can be exported to Excel sheet for further analysis. It reduces the burden of calculation and saves considerable time i.e., 2 min computer time as compared with 102 min (manual calculation with the calculator for all seven formulas for 25 patients). The software detailed above appears to be an easy and useful method for calculation of pediatric RPH dose in routine clinical practice. This software application will help in helping the user to routinely applied ALARA principle while pediatric dose administration. (author)

  12. Repeated allergen exposure reduce early phase airway response and leukotriene release despite upregulation of 5-lipoxygenase pathways

    Directory of Open Access Journals (Sweden)

    Cui Zhi-Hua

    2012-03-01

    Full Text Available Abstract Background Allergen induced early phase airway response and airway plasma exudation are predominantly mediated by inflammatory mast cell mediators including histamine, cysteinyl leukotrienes (cysLTs and thromboxane A2 (TXA2. The aim of the present study was to evaluate whether repeated allergen exposure affects early phase airway response to allergen challenge. Methods A trimellitic anhydride (TMA sensitized guinea pig model was used to investigate the effects of low dose repeated allergen exposure on cholinergic airway responsiveness, early phase airway response and plasma exudation, as well as local airway production of mast cell derived cysteinyl leukotrienes and thromboxane B2 (TXB2 after allergen challenge. Results Repeated low dose allergen exposure increased cholinergic airway responsiveness. In contrast, early phase airway response and plasma exudation in response to a high-dose allergen challenge were strongly attenuated after repeated low dose allergen exposure. Inhibition of the airway response was unspecific to exposed allergen and independent of histamine receptor blocking. Furthermore, a significant reduction of cysteinyl leukotrienes and TXB2 was found in the airways of animals repeatedly exposed to a low dose allergen. However, in vitro stimulation of airway tissue from animals repeatedly exposed to a low dose allergen with arachidonic acid and calcium ionophore (A23187 induced production of cysteinyl leukotrienes and TXB2, suggesting enhanced activity of 5-lipoxygenase and cyclooxygenase pathways. Conclusions The inhibition of the early phase airway response, cysteinyl leukotriene and TXB2 production after repeated allergen exposure may result from unresponsive effector cells.

  13. Inter-Simple Sequence Repeat (ISSR Markers to Study Genetic Diversity Among Cotton Cultivars in Associated with Salt Tolerance

    Directory of Open Access Journals (Sweden)

    Ali Akbar ABDI

    2012-11-01

    Full Text Available Developing salt-tolerant crops is very important as a significant proportion of cultivated land is salt-affected. Screening and selection of salt tolerant genotypes of cotton using DNA molecular markers not only introduce tolerant cultivars useful for hybridization and breeding programs but also detect DNA regions involved in mechanism of salinity tolerance. To study this, 28 cotton cultivars, including 8 Iranian cotton varieties were grown in pots under greenhouse condition and three salt treatments were imposed with salt solutions (0, 70 and 140 mM NaCl. Eight agronomic traits including root length, root fresh weight, root dry weight, chlorophyll and fluorescence index, K+ and Na+ contents in shoot (above ground biomass, and K+/Na+ ratio were measured. Cluster analysis of cultivars based on measured agronomic traits, showed �Cindose� and �Ciacra� as the most tolerant cultivars, and �B-557� and �43347� as the most sensitive cultivars of salt damage. A total of 65 polymorphic DNA fragments were generated at 14 inter-simple sequence repeat (ISSR loci. Plants of 28 cultivars of cotton grouped into three clusters based on ISSR markers. Regression analysis of markers in relation with traits data showed that 23, 33 and 30 markers associated with the measured traits in three salt treatments respectively. These markers might help breeders in any marker assisted selection program in order to improving cotton cultivars against salt stress.

  14. Analytical studies on the impact of using repeated-rib roughness in LMR [Liquid Metal Reactor] decay heat removal systems

    International Nuclear Information System (INIS)

    Obot, N.T.; Tessier, J.H.; Pedersen, D.R.

    1988-01-01

    A numerical study was carried out to determine the effects of roughness on the thermal performance of Liquid Metal Reactor (LMR) decay heat removal systems for a range of possible design configurations and operating conditions. The ranges covered for relative rib height (e/D/sub h/), relative pitch (p/e) and flow attack angle were 0.026--0.103, 5--20 and 0--90 degrees, successively. The heat flux was varied between 1.1 and 21.5 kW/m 2 (0.1 and 2.0 kW/ft 2 ). Calculations were made for three cases: smooth duct with no ribs, ribs on both the guard vessel and collector wall, and ribs on the collector wall only. The results indicate that significant benefits, amounting to nearly two-fold reductions in guard vessel and collector wall temperatures, can be realized by placing repeated ribs on both the guard vessel and the collector wall. The magnitudes of the reduction in the reactor vessel temperature are considerably smaller. In general, the level of improvement, be it with respect to temperature or heat flux, is only mildly affected by changes in rib height or pitch but exhibits greater sensitivity to the assumed value for the system form loss. When the ribs are placed only on the collector wall, the heat removal capability is substantially reduced

  15. Film repeats in radiology department

    International Nuclear Information System (INIS)

    Suwan, A. Z.; Al-Shakharah, A. I

    1997-01-01

    During a one year period, 4910 radiographs of 55780 films were repeated. The objective of our study was to analyse and to classify the causes in order to minimize the repeats, cut the expenses and to provide optimal radiographs for accurate diagnosis. Analysis of the different factors revealed that, 43.6% of film repeats in our service were due to faults in exposure factors, centering comprises 15.9% of the repeats, while too much collimation was responsible for 7.6% of these repeats. All of which can be decreased by awareness and programmed training of technicians. Film blurring caused by patient motion was also responsible for 4.9% for radiographs reexamination, which can be minimized by detailed explanation to the patient and providing the necessary privacy. Fogging of X-Ray films by improper storage or inadequate handling or processing faults were responsible for 14.5% in repeats in our study. Methods and criteria for proper storage and handling of films were discussed. Recommendation for using modern day-light and laser processor has been high lighted. Artefacts are noticeably high in our cases, due to spinal dresses and frequent usage of precious metals for c osmotic purposes in this part of the world. The repeated films comprise 8.8% of all films We conclude that, the main factor responsible for repeats of up to 81.6% of cases was the technologists, thus emphasizing the importance of adequate training of the technologists. (authors). 15 refs., 9 figs., 1 table

  16. Public perception of drinking water safety in South Africa 2002–2009: a repeated cross-sectional study

    Science.gov (United States)

    2012-01-01

    Background In low and middle income countries, public perceptions of drinking water safety are relevant to promotion of household water treatment and to household choices over drinking water sources. However, most studies of this topic have been cross-sectional and not considered temporal variation in drinking water safety perceptions. The objective of this study is to explore trends in perceived drinking water safety in South Africa and its association with disease outbreaks, water supply and household characteristics. Methods This repeated cross-sectional study draws on General Household Surveys from 2002–2009, a series of annual nationally representative surveys of South African households, which include a question about perceived drinking water safety. Trends in responses to this question were examined from 2002–2009 in relation to reported cholera cases. The relationship between perceived drinking water safety and organoleptic qualities of drinking water, supply characteristics, and socio-economic and demographic household characteristics was explored in 2002 and 2008 using hierarchical stepwise logistic regression. Results The results suggest that perceived drinking water safety has remained relatively stable over time in South Africa, once the expansion of improved supplies is controlled for. A large cholera outbreak in 2000–02 had no apparent effect on public perception of drinking water safety in 2002. Perceived drinking water safety is primarily related to water taste, odour, and clarity rather than socio-economic or demographic characteristics. Conclusion This suggests that household perceptions of drinking water safety in South Africa follow similar patterns to those observed in studies in developed countries. The stability over time in public perception of drinking water safety is particularly surprising, given the large cholera outbreak that took place at the start of this period. PMID:22834485

  17. Public perception of drinking water safety in South Africa 2002-2009: a repeated cross-sectional study.

    Science.gov (United States)

    Wright, Jim A; Yang, Hong; Rivett, Ulrike; Gundry, Stephen W

    2012-07-27

    In low and middle income countries, public perceptions of drinking water safety are relevant to promotion of household water treatment and to household choices over drinking water sources. However, most studies of this topic have been cross-sectional and not considered temporal variation in drinking water safety perceptions. The objective of this study is to explore trends in perceived drinking water safety in South Africa and its association with disease outbreaks, water supply and household characteristics. This repeated cross-sectional study draws on General Household Surveys from 2002-2009, a series of annual nationally representative surveys of South African households, which include a question about perceived drinking water safety. Trends in responses to this question were examined from 2002-2009 in relation to reported cholera cases. The relationship between perceived drinking water safety and organoleptic qualities of drinking water, supply characteristics, and socio-economic and demographic household characteristics was explored in 2002 and 2008 using hierarchical stepwise logistic regression. The results suggest that perceived drinking water safety has remained relatively stable over time in South Africa, once the expansion of improved supplies is controlled for. A large cholera outbreak in 2000-02 had no apparent effect on public perception of drinking water safety in 2002. Perceived drinking water safety is primarily related to water taste, odour, and clarity rather than socio-economic or demographic characteristics. This suggests that household perceptions of drinking water safety in South Africa follow similar patterns to those observed in studies in developed countries. The stability over time in public perception of drinking water safety is particularly surprising, given the large cholera outbreak that took place at the start of this period.

  18. "Focused introspection" during naturally increased diuresis: description and repeatability of a method to study bladder sensation non-invasively.

    Science.gov (United States)

    De Wachter, Stefan G G; Heeringa, Rhea; Van Koeveringe, Gommert A; Winkens, Bjorn; Van Kerrebroeck, Philip E V; Gillespie, James I

    2014-06-01

    To present and describe a non-invasive method to study the origin and development of bladder filling sensation and to evaluate the repeatability of the method. Eighteen volunteers participated in the study and were given a water loading protocol consisting of 1,000 ml water intake 1 hr before the session and 200 ml every 10 min during the session. Protocol 1: To evaluate diuresis rate, seven participants were asked to void every 15 min and the voided volume was measured. Protocol 2: Eleven volunteers graded bladder sensation on regular time points, on an empty graph with time on the X-axis and intensity of sensation on the Y-axis. The protocol ended at absolute need to void (maximal intensity) and voided volumes were measured. This protocol was conducted three times with a 10 days interval. Protocol 1: The diuresis rate was not different during the sessions and showed no variation over the studied time period (P = 0.2). Protocol 2: For an individual, the diuresis rate was not different between the sessions. The curves in all patients showed a continuously increasing bladder intensity. In seven participants the curve was convex, in the other four, the curve was sigmoidal. For each individual the pattern was constant during the three sessions. A strict water loading protocol induces a constant diuresis. This allows individuals to draw an introspection bladder sensation curve with a specific shape, which can be used as a method to study the development of bladder sensation non-invasively. © 2013 Wiley Periodicals, Inc.

  19. Public perception of drinking water safety in South Africa 2002–2009: a repeated cross-sectional study

    Directory of Open Access Journals (Sweden)

    Wright Jim A

    2012-07-01

    Full Text Available Abstract Background In low and middle income countries, public perceptions of drinking water safety are relevant to promotion of household water treatment and to household choices over drinking water sources. However, most studies of this topic have been cross-sectional and not considered temporal variation in drinking water safety perceptions. The objective of this study is to explore trends in perceived drinking water safety in South Africa and its association with disease outbreaks, water supply and household characteristics. Methods This repeated cross-sectional study draws on General Household Surveys from 2002–2009, a series of annual nationally representative surveys of South African households, which include a question about perceived drinking water safety. Trends in responses to this question were examined from 2002–2009 in relation to reported cholera cases. The relationship between perceived drinking water safety and organoleptic qualities of drinking water, supply characteristics, and socio-economic and demographic household characteristics was explored in 2002 and 2008 using hierarchical stepwise logistic regression. Results The results suggest that perceived drinking water safety has remained relatively stable over time in South Africa, once the expansion of improved supplies is controlled for. A large cholera outbreak in 2000–02 had no apparent effect on public perception of drinking water safety in 2002. Perceived drinking water safety is primarily related to water taste, odour, and clarity rather than socio-economic or demographic characteristics. Conclusion This suggests that household perceptions of drinking water safety in South Africa follow similar patterns to those observed in studies in developed countries. The stability over time in public perception of drinking water safety is particularly surprising, given the large cholera outbreak that took place at the start of this period.

  20. The study of mean glandular dose in mammography in Yazd and the factors affecting it

    International Nuclear Information System (INIS)

    Bouzarjomehri, F.; Mostaar, A.; Ghasemi, A.; Ehramposh, M. H.; Khosravi, H.

    2006-01-01

    The objective of this study was to determine the mean glandular dose resulting from mammography examinations in Yazd, southeastern Iran and to identify the factors affecting it. Patients and Methods: This survey was conducted during May to December 2005 to estimate the mean glandular dose for women undergoing mammography and to report the distribution of dose. compressed breast thickness, glandular tissue content, and mammography technique used. The clinical data were collected from 946 mammograms taken from 246 women who were referred to four mammography centers. The mammography instruments in these centers were four modern units with a molybdenum anode and either molybdenum or rhodium filter. The exposure conditions of each mammogram were recorded. The breast glandular content of each mammogram was estimated by a radiologist. The mean glandular dose was calculated based on measuring the normalized entrance skin dose in air. half value layer, kVp, mAs, breast thickness and glandular content. Half value layer, kVp and entrance skin dose were measured by a solid-state detector. The analytical method of Sobol et al. was used for calculation of mean glandular dose . Results: The mean±SD mean glandular dose per film was.2±0.6 mGy for cranio caudal and 1.63±O.9 mGy for mediolateral oblique views. The mean±SD mean glandular dose per woman was 5.5 3.1.mGy. A positive correlation was found between the beam Half value layer with mean glandular dose (r=O.38) and the breast thickness with mean glandular dose (r=O.5). Conclusion: The mean±SD mean glandular dose per film of 1.42±0.8 mGy in present study was lower than most of similar reports. However, the mean mean glandular dose per woman was higher than that in other studies

  1. Relapse of imported Plasmodium vivax malaria is related to primaquine dose: a retrospective study

    Directory of Open Access Journals (Sweden)

    Townell Nicola

    2012-06-01

    Full Text Available Abstract Background Relapsing Plasmodium vivax infection results in significant morbidity for the individual and is a key factor in transmission. Primaquine remains the only licensed drug for prevention of relapse. To minimize relapse rates, treatment guidelines have recently been revised to recommend an increased primaquine dose, aiming to achieve a cumulative dose of ≥6 mg/kg, i.e. ≥420 mg in a 70 kg patient. The aims of this study were to characterize the epidemiology of P. vivax infection imported into Queensland Australia, to determine the rates of relapse, to investigate the use of primaquine therapy, and its efficacy in the prevention of relapse. Methods A retrospective study was undertaken of laboratory confirmed P. vivax infection presenting to the two major tertiary hospitals in Queensland, Australia between January 1999 and January 2011. Primaquine dosing was classified as no dose, low dose ( Results Twenty relapses occurred following 151 primary episodes of P. vivax infection (13.2%. Relapses were confirmed among 3/21 (14.2%, 9/50 (18.0%, 1/54 (1.9% and 7/18 (38.9% of patients administered no dose, low dose, high dose and unknown primaquine dose respectively. High dose primaquine therapy was associated with a significantly lower rate of relapse compared to patients who were prescribed low dose therapy (OR 11.6, 95% CI 1.5-519, p = 0.005. Conclusions Relapse of P. vivax infection is more likely in patients who received low dose primaquine therapy. This study supports the recommendations that high dose primaquine therapy is necessary to minimize relapse of P. vivax malaria.

  2. An experimental study for the reduction of population dose

    International Nuclear Information System (INIS)

    Muroi, Makoto

    1984-01-01

    It is a well-known fact that to reduce the amount of X-ray exposure, it is absolutely necessary to limit the field size to the minimum needed for the purpose of examination and size of the object. However, as dental X-ray apparatuses are not fitted with movable collimators, a fixed field size is applied to all exposures of intraoral radiography that is most frequently used for the dental region. Therefore, as one means of reducing the field size, the development of a changeable diaphragm for use in intraoral radiography has been undertaken. Also measurements were made of critical organ doses by field size and a nationwide survey was carried out to ascertain the frequency of intraoral radiography, through which review was made of the degree of contribution the changeable diaphragm could bring about in reducing the population dose. Much effort has led to success in the building of a changeable diaphragm into a central ray indicating cone which permits easy tube head alignment and maintenace of a set focus-skin distance. It was also found that approximately 50% of all intraoral radiography performed in Japan could have been accomplished by smaller field sizes. (author)

  3. Combined Study of Titanium Dioxide Nanoparticle Transport and Toxicity on Microbial Nitrifying Communities under Single and Repeated Exposures in Soil Columns.

    Science.gov (United States)

    Simonin, Marie; Martins, Jean M F; Uzu, Gaëlle; Vince, Erwann; Richaume, Agnès

    2016-10-04

    Soils are exposed to nanoparticles (NPs) as a result of their increasing use in many commercial products. Adverse effects of NPs on soil microorganisms have been reported in several ecotoxicological studies using microcosms. Although repeated exposures are more likely to occur in soils, most of these previous studies were performed as a single exposure to NPs. Contrary to single contamination, the study of multiple NP contaminations in soils requires the use of specialized setups. Using a soil column experiment, we compared the influence of single and repeated exposures (one, two, or three exposures that resulted in the same final concentration applied) on the transport of titanium dioxide (TiO 2 ) NPs through soil and the effect of these different exposure scenarios on the abundance and activity of soil nitrifying microbial communities after a 2 month incubation. The transport of TiO 2 NPs was very limited under both single and repeated exposures and was highest for the lowest concentration injected during the first application. Significant decreases in nitrification activity and ammonia-oxidizing archaea and bacteria populations were observed only for the repeated exposure scenario (three TiO 2 NP contaminations). These results suggest that, under repeated exposures, the transport of TiO 2 NPs to deep soil layers and groundwater is limited and that a chronic contamination is more harmful for the soil microbiological functioning than a single exposure.

  4. Trends in standardized mortality among individuals with schizophrenia, 1993–2012: a population-based, repeated cross-sectional study

    Science.gov (United States)

    Gatov, Evgenia; Rosella, Laura; Chiu, Maria; Kurdyak, Paul A.

    2017-01-01

    BACKGROUND: We examined mortality time trends and premature mortality among individuals with and without schizophrenia over a 20-year period. METHODS: In this population-based, repeated cross-sectional study, we identified all individual deaths that occurred in Ontario between 1993 and 2012 in persons aged 15 and over. We plotted overall and cause-specific age- and sex-standardized mortality rates (ASMRs), stratified all-cause ASMR trends by sociodemographic characteristics, and analyzed premature mortality using years of potential life lost. Additionally, we calculated mortality rate ratios (MRRs) using negative binomial regression with adjustment for age, sex, income, rurality and year of death. RESULTS: We identified 31 349 deaths among persons with schizophrenia, and 1 589 902 deaths among those without schizophrenia. Mortality rates among people with schizophrenia were 3 times higher than among those without schizophrenia (adjusted MRR 3.12, 95% confidence interval 3.06–3.17). All-cause ASMRs in both groups declined in parallel over the study period, by about 35%, and were higher for men, for those with low income and for rural dwellers. The absolute ASMR difference also declined throughout the study period (from 16.15 to 10.49 deaths per 1000 persons). Cause-specific ASMRs were greater among those with schizophrenia, with circulatory conditions accounting for most deaths between 1993 and 2012, whereas neoplasms became the leading cause of death for those without schizophrenia after 2005. Individuals with schizophrenia also died, on average, 8 years younger than those without schizophrenia, losing more potential years of life. INTERPRETATION: Although mortality rates among people with schizophrenia have declined over the past 2 decades, specialized approaches may be required to close the persistent 3-fold relative mortality gap with the general population. PMID:28923795

  5. Trends in standardized mortality among individuals with schizophrenia, 1993-2012: a population-based, repeated cross-sectional study.

    Science.gov (United States)

    Gatov, Evgenia; Rosella, Laura; Chiu, Maria; Kurdyak, Paul A

    2017-09-18

    We examined mortality time trends and premature mortality among individuals with and without schizophrenia over a 20-year period. In this population-based, repeated cross-sectional study, we identified all individual deaths that occurred in Ontario between 1993 and 2012 in persons aged 15 and over. We plotted overall and cause-specific age- and sex-standardized mortality rates (ASMRs), stratified all-cause ASMR trends by sociodemographic characteristics, and analyzed premature mortality using years of potential life lost. Additionally, we calculated mortality rate ratios (MRRs) using negative binomial regression with adjustment for age, sex, income, rurality and year of death. We identified 31 349 deaths among persons with schizophrenia, and 1 589 902 deaths among those without schizophrenia. Mortality rates among people with schizophrenia were 3 times higher than among those without schizophrenia (adjusted MRR 3.12, 95% confidence interval 3.06-3.17). All-cause ASMRs in both groups declined in parallel over the study period, by about 35%, and were higher for men, for those with low income and for rural dwellers. The absolute ASMR difference also declined throughout the study period (from 16.15 to 10.49 deaths per 1000 persons). Cause-specific ASMRs were greater among those with schizophrenia, with circulatory conditions accounting for most deaths between 1993 and 2012, whereas neoplasms became the leading cause of death for those without schizophrenia after 2005. Individuals with schizophrenia also died, on average, 8 years younger than those without schizophrenia, losing more potential years of life. Although mortality rates among people with schizophrenia have declined over the past 2 decades, specialized approaches may be required to close the persistent 3-fold relative mortality gap with the general population. © 2017 Canadian Medical Association or its licensors.

  6. Strengthening leadership as a catalyst for enhanced patient safety culture: a repeated cross-sectional experimental study.

    Science.gov (United States)

    Kristensen, Solvejg; Christensen, Karl Bang; Jaquet, Annette; Møller Beck, Carsten; Sabroe, Svend; Bartels, Paul; Mainz, Jan

    2016-05-13

    Current literature emphasises that clinical leaders are in a position to enable a culture of safety, and that the safety culture is a performance mediator with the potential to influence patient outcomes. This paper aims to investigate staff's perceptions of patient safety culture in a Danish psychiatric department before and after a leadership intervention. A repeated cross-sectional experimental study by design was applied. In 2 surveys, healthcare staff were asked about their perceptions of the patient safety culture using the 7 patient safety culture dimensions in the Safety Attitudes Questionnaire. To broaden knowledge and strengthen leadership skills, a multicomponent programme consisting of academic input, exercises, reflections and discussions, networking, and action learning was implemented among the clinical area level leaders. In total, 358 and 325 staff members participated before and after the intervention, respectively. 19 of the staff members were clinical area level leaders. In both surveys, the response rate was >75%. The proportion of frontline staff with positive attitudes improved by ≥5% for 5 of the 7 patient safety culture dimensions over time. 6 patient safety culture dimensions became more positive (increase in mean) (pculture are remarkable, and imply that strengthening the leadership can act as a significant catalyst for patient safety culture improvement. Further studies using a longitudinal study design are recommended to investigate the mechanism behind leadership's influence on patient safety culture, sustainability of improvements over time, and the association of change in the patient safety culture measures with change in psychiatric patient safety outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Repeatability of visual acuity measurement.

    Science.gov (United States)

    Raasch, T W; Bailey, I L; Bullimore, M A

    1998-05-01

    This study investigates features of visual acuity chart design and acuity testing scoring methods which affect the validity and repeatability of visual acuity measurements. Visual acuity was measured using the Sloan and British Standard letter series, and Landolt rings. Identifiability of the different letters as a function of size was estimated, and expressed in the form of frequency-of-seeing curves. These functions were then used to simulate acuity measurements with a variety of chart designs and scoring criteria. Systematic relationships exist between chart design parameters and acuity score, and acuity score repeatability. In particular, an important feature of a chart, that largely determines the repeatability of visual acuity measurement, is the amount of size change attributed to each letter. The methods used to score visual acuity performance also affect repeatability. It is possible to evaluate acuity score validity and repeatability using the statistical principles discussed here.

  8. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    Science.gov (United States)

    Osman, N. D.; Shamsuri, S. B. M.; Tan, Y. W.; Razali, M. A. S. M.; Isa, S. M.

    2017-05-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDIvol and CTDIw) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDIw ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients.

  9. A single institution study of radiation dose received from CT imaging: A comparison to Malaysian NDRL

    International Nuclear Information System (INIS)

    Osman, N D; Shamsuri, S B M; Razali, M A S M; Isa, S M; Tan, Y W

    2017-01-01

    Advancement of CT technology has led to an increase in CT scanning as it improves the diagnosis. However, it is important to assess health risk of patients associated with ionising radiation received from CT. This study evaluated current dose distributions at Advanced Medical and Dental Institute (AMDI), Malaysia and was used to establish Local Diagnostic Reference Level (LDRL). Dose indicators such as CT Dose Index (CTDI vol and CTDI w ) and Dose-Length Product (DLP) were gathered for all routine CT examinations performed at the Imaging Unit, AMDI from January 2015 to June 2016. The first and third quartile values for each dose indicator were determined. A total of 364 CT studies were performed during that period with the highest number of cases being Thorax-Abdomen-Pelvis (TAP) study (57% of total study). The CTDI w ranged between 2.0 mGy to 23.4 mGy per procedure. DLP values were ranged between 94 mGy.cm to 1687 mGy.cm. The local dose data was compared with the national DRL to monitor the current CT practice at AMDI and LDRL will be established from the calculated third quartile values of dose distribution. From the results, some of the local dose values exceeded the Malaysian and further evaluation is important to ensure the dose optimisation for patients. (paper)

  10. Take with Food: Study Tests Lowering Dose of Prostate Cancer Drug

    Science.gov (United States)

    ... Cancer Currents Blog Cancer Currents Blog Take with Food: Study Tests Lowering Dose of Prostate Cancer Drug Subscribe April ... to this page included, e.g., “Take with Food: Study Tests Lowering Dose of Prostate Cancer Drug was originally ...

  11. Repeat polymorphisms in ESR2 and AR and colorectal cancer risk and prognosis: results from a German population-based case-control study.

    Science.gov (United States)

    Rudolph, Anja; Shi, Hong; Försti, Asta; Hoffmeister, Michael; Sainz, Juan; Jansen, Lina; Hemminki, Kari; Brenner, Hermann; Chang-Claude, Jenny

    2014-11-07

    Evidence has accumulated which suggests that sex steroids influence colorectal cancer development and progression. We therefore assessed the association of repeat polymorphisms in the estrogen receptor β gene (ESR2) and the androgen receptor gene (AR) with colorectal cancer risk and prognosis. The ESR2 CA and AR CAG repeat polymorphisms were genotyped in 1798 cases (746 female, 1052 male) and 1810 controls (732 female, 1078 male), matched for sex, age and county of residence. Colorectal cancer risk associations overall and specific for gender were evaluated using multivariate logistic regression models adjusted for sex, county of residence and age. Associations with overall and disease-specific survival were evaluated using Cox proportional hazard models adjusted for established prognostic factors (diagnosis of other cancer after colorectal cancer diagnosis, detection by screening, treatment with adjuvant chemotherapy, tumour extent, nodal status, distant metastasis, body mass index, age at diagnosis and year of diagnosis) and stratified for grade of differentiation. Heterogeneity in gender specific associations was assessed by comparing models with and without a multiplicative interaction term by means of a likelihood ratio test. The average number of ESR2 CA repeats was associated with a small 5% increase in colorectal cancer risk (OR = 1.05, 95% CI 1.01-1.10) without significant heterogeneity according to gender or tumoural ESR2 expression. We found no indication for an association between the AR CAG repeat polymorphisms and risk of colorectal cancer. The ESR2 CA and AR CAG repeat polymorphisms were not associated with overall survival or disease specific survival after colorectal cancer diagnosis. Higher numbers of ESR2 CA repeats are potentially associated with a small increase in colorectal cancer risk. Our study does not support an association between colorectal cancer prognosis and the investigated repeat polymorphisms.

  12. Patch test dose-response study of p-phenylenediamine

    DEFF Research Database (Denmark)

    Sosted, Heidi; Menné, Torkil; Johansen, Jeanne Duus

    2006-01-01

    The elicitation response in allergic contact dermatitis for the hair dye substance p-phenylenediamine (PPD) is dose dependent, but threshold concentrations have not previously been investigated. 15 PPD-sensitive patients participated in a serial dilution 48-hr patch test with PPD using 8...... concentrations of PPD ranging from 1 to 10 000 on the upper back. Petrolatum was applied as control. Three concentrations (50, 100 and 500 p.p.m. PPD) were also applied to the retroauricular area and on the lateral aspects of the upper arms. 14 of the 15 participants reacted to one or more of the test samples....... The threshold value for 10% of the tested persons (ED10) based on+or stronger reactions for PPD on the back was 38 p.p.m. (CI: 4.3-100). There were no statistically significant differences in the sensitivity of the three anatomical regions. The upper back is a suitable region for patch testing patients...

  13. Dose-effect studies with inhaled plutonium oxide in beagles

    International Nuclear Information System (INIS)

    Park, J.F.; Buschbom, R.L.; Case, A.C.

    1976-01-01

    Beagle dogs given single exposure to 239 PuO 2 or 238 PuO 2 aerosols are being observed for life-span dose-effect relationships. The 239 Pu body burden of the nine dogs dying due to pulmonary fibrosis-induced insufficiency during the first 3 years after exposure was 1 to 12 μCi. One of these dogs had a pulmonary tumor. Three additional dogs with body burdens of 0.7 to 1.8 μCi died due to pulmonary neoplasia 4-1/2 years after exposure. None of the dogs exposed to 238 Pu have died during the first two postexposure years. After inhalation of 239 PuO 2 or 238 PuO 2 lymphocytopenia was the earliest observed effect, occuring 0.5 to 2 years after deposition of greater than or equal to 80 nCi plutonium in the lungs

  14. Dose-effect studies with inhaled plutonium oxide in beagles

    International Nuclear Information System (INIS)

    Park, J.F.; Buschbom, R.L.; Case, A.C.

    1977-01-01

    Beagle dogs given a single exposure to 239 PuO 2 or 238 PuO 2 aerosols are being observed for life-span dose-effect relationships. The 239 Pu body burden of the nine dogs that died of pulmonary fibrosis-induced respiratory insufficiency during the first 3 yr after exposure was 1 to 12 μCi. One of these dogs had a pulmonary tumor. Five additional dogs with body burdens of 0.7 to 1.8 μCi died due to pulmonary neoplasia 3 to 5 yr after exposure. None of the dogs exposed to 238 Pu have died during the first 3 postexposure yr. Lymphocytopenia was the earliest observed effect after inhalation of 239 PuO 2 or 238 PuO 2 , occurring 0.5 to 2 yr after deposition of greater than or equal to 80 nCi plutonium in the lungs

  15. Validation and Reliability of a Smartphone Application for the International Prostate Symptom Score Questionnaire: A Randomized Repeated Measures Crossover Study

    Science.gov (United States)

    Shim, Sung Ryul; Sun, Hwa Yeon; Ko, Young Myoung; Chun, Dong-Il; Yang, Won Jae

    2014-01-01

    Background Smartphone-based assessment may be a useful diagnostic and monitoring tool for patients. There have been many attempts to create a smartphone diagnostic tool for clinical use in various medical fields but few have demonstrated scientific validity. Objective The purpose of this study was to develop a smartphone application of the International Prostate Symptom Score (IPSS) and to demonstrate its validity and reliability. Methods From June 2012 to May 2013, a total of 1581 male participants (≥40 years old), with or without lower urinary tract symptoms (LUTS), visited our urology clinic via the health improvement center at Soonchunhyang University Hospital (Republic of Korea) and were enrolled in this study. A randomized repeated measures crossover design was employed using a smartphone application of the IPSS and the conventional paper form of the IPSS. Paired t test under a hypothesis of non-inferior trial was conducted. For the reliability test, the intraclass correlation coefficient (ICC) was measured. Results The total score of the IPSS (P=.289) and each item of the IPSS (P=.157-1.000) showed no differences between the paper version and the smartphone version of the IPSS. The mild, moderate, and severe LUTS groups showed no differences between the two versions of the IPSS. A significant correlation was noted in the total group (ICC=.935, Psmartphones could participate. Conclusions The validity and reliability of the smartphone application version were comparable to the conventional paper version of the IPSS. The smartphone application of the IPSS could be an effective method for measuring lower urinary tract symptoms. PMID:24513507

  16. Improvement in Trainees' Attitude and Resuscitation Quality With Repeated Cardiopulmonary Resuscitation Training: Cross-Sectional Simulation Study.

    Science.gov (United States)

    Kim, Jong Won; Lee, Jeong Hun; Lee, Kyeong Ryong; Hong, Dae Young; Baek, Kwang Je; Park, Sang O

    2016-08-01

    This study investigated the effect of increasing numbers of training sessions in cardiopulmonary resuscitation (CPR) on trainees' attitude and CPR quality. Cardiopulmonary resuscitation training for hospital employees was held every year from 2006 to 2010. Participants were recruited among the trainees in 2010. The trainees' attitudes toward CPR were surveyed by questionnaire, and the quality of their CPR was measured using 5-cycle 30:2 CPR on a manikin. Participants were categorized according to the number of consecutive CPR training sessions as T1 (only 2010), T2 (2009 and 2010), T3 (from 2008 to 2010) and T4-5 (from 2006 or 2007 to 2010). The trainee attitude and CPR quality were compared among the 4 groups. Of 923 CPR trainees, 267 were enrolled in the study. There was significant increase in willingness to start CPR and confidence in chest compression and mouth-to-mouth ventilation (MTMV) with increasing number of CPR training sessions attended (especially for ≥ 3 sessions). There was a significant increase in mean compression depth and decrease in percentage of chest compressions with depth of less than 38 mm in the T3 and T4-5 compared with the T1 and T2. No-flow time decreased significantly, and the percentage of MTMV with visible chest rise increased, as the number of training sessions increased. Repeated CPR training improved trainees' attitude and CPR quality. Because the number of training sessions increased (≥3), the willingness to start CPR and the confidence in skills increased significantly, and chest compression depth, no-flow time, and MTMV improved.

  17. Study on the method or reducing the operator's exposure dose from a C-Arm system

    International Nuclear Information System (INIS)

    Kim, Ki Sik; Song, Jong Nam; Kim, Seung Ok

    2016-01-01

    In this study, C-Arm equipment is being used as we intend to verify the exposure dose on the operator by the scattering rays during the operation of the C-Arm equipment and to provide an effective method of reducing the exposure dose. Exposure dose is less than the Over Tube method utilizes the C-arm equipment Under Tube the scheme, The result showed that the exposure dose on the operator decreased with a thicker shield, and as the operator moved away from the center line. Moreover, as the research time prolongated, the exposure dose increased, and among the three affixed location of the dosimeter, the most exposure dose was measured at gonadal, then followed by chest and thyroid. However, in consideration of the relationship between the operator and the patient, the distance cannot be increased infinitely and the research time cannot be decreased infinitely in order to reduce the exposure dose. Therefore, by changing the thickness of the radiation shield, the exposure dose on the operator was able to be reduced. If you are using a C-Arm equipment discomfort during surgery because the grounds that the procedure is neglected and close to the dose of radiation shielding made can only increase. Because a separate control room cannot be used for the C-Arm equipment due to its characteristic, the exposure dose on the operator needs to be reduced by reinforcing the shield through an appropriate thickness of radiation shield devices, such as apron, etc. during a treatment

  18. Design study on dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio; Kudo, Seiichi; Nishimura, Kazuya

    2001-01-01

    When we assume a severe accident in a nuclear power plant, it is required for rescue activity in the plant, accident management, repair work of failed parts and evaluation of employees to obtain radiation dose rate distribution or map in the plant and estimated dose value for the above works. However it might be difficult to obtain them accurately along the progress of the accident, because radiation monitors are not always installed in the areas where the accident management is planned or the repair work is thought for safety-related equipments. In this work, we analyzed diffusion of radioactive materials in case of a severe accident in a pressurized water reactor plant, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system by modeling a specific part of components and buildings in the plant from this design study on dose evaluation method for employees at severe accident, and then evaluated its availability. As a result, we obtained the followings: (1) A new dose evaluation method was established to predict the radiation dose rate in any point in the plant during a severe accident scenario. (2) This evaluation of total dose including moving route and time for the accident management and the repair work is useful for estimating radiation dose limit for these actions of the employees. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  19. Design study on dose evaluation method for employees at severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio [Institute of Nuclear Safety Systems Inc., Mihama, Fukui (Japan); Kudo, Seiichi [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Nishimura, Kazuya [Computer Software Development Co., Ltd., Tokyo (Japan)

    2001-09-01

    When we assume a severe accident in a nuclear power plant, it is required for rescue activity in the plant, accident management, repair work of failed parts and evaluation of employees to obtain radiation dose rate distribution or map in the plant and estimated dose value for the above works. However it might be difficult to obtain them accurately along the progress of the accident, because radiation monitors are not always installed in the areas where the accident management is planned or the repair work is thought for safety-related equipments. In this work, we analyzed diffusion of radioactive materials in case of a severe accident in a pressurized water reactor plant, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system by modeling a specific part of components and buildings in the plant from this design study on dose evaluation method for employees at severe accident, and then evaluated its availability. As a result, we obtained the followings: (1) A new dose evaluation method was established to predict the radiation dose rate in any point in the plant during a severe accident scenario. (2) This evaluation of total dose including moving route and time for the accident management and the repair work is useful for estimating radiation dose limit for these actions of the employees. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Dose painting based on tumor uptake of Cu-ATSM and FDG: a comparative study

    International Nuclear Information System (INIS)

    Clausen, Malene Martini; Hansen, Anders Elias; Lundemann, Michael; Hollensen, Christian; Pommer, Tobias; Munck af Rosenschöld, Per; Kristensen, Annemarie Thuri; Kjær, Andreas; McEvoy, Fintan J; Engelholm, Svend Aage

    2014-01-01

    Hypoxia and increased glycolytic activity of tumors are associated with poor prognosis. The purpose of this study was to investigate differences in radiotherapy (RT) dose painting based on the uptake of 2-deoxy-2-[ 18 F]-fluorodeoxyglucose (FDG) and the proposed hypoxia tracer, copper(II)diacetyl-bis(N 4 )-methylsemithiocarbazone (Cu-ATSM) using spontaneous clinical canine tumor models. Positron emission tomography/computed tomography scans of five spontaneous canine sarcomas and carcinomas were obtained; FDG on day 1 and 64 Cu-ATSM on day 2 and 3 (approx. 3 and 24 hours pi.). Sub-volumes for dose escalation were defined by a threshold-based method for both tracers and five dose escalation levels were formed in each sub-volume. Volumetric modulated arc therapy plans were optimized based on the dose escalation regions for each scan for a total of three dose plans for each dog. The prescription dose for the GTV was 45 Gy (100%) and it was linearly escalated to a maximum of 150%. The correlations between dose painting plans were analyzed with construction of dose distribution density maps and quality volume histograms (QVH). Correlation between high-dose regions was investigated with Dice correlation coefficients. Comparison of dose plans revealed varying degree of correlation between cases. Some cases displayed a separation of high-dose regions in the comparison of FDG vs. 64 Cu-ATSM dose plans at both time points. Among the Dice correlation coefficients, the high dose regions showed the lowest degree of agreement, indicating potential benefit of using multiple tracers for dose painting. QVH analysis revealed that FDG-based dose painting plans adequately covered approximately 50% of the hypoxic regions. Radiotherapy plans optimized with the current approach for cut-off values and dose region definitions based on FDG, 64 Cu-ATSM 3 h and 24 h uptake in canine tumors had different localization of the regional dose escalation levels. This indicates that 64 Cu-ATSM at two

  2. Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose in Future Studies. A Response to the Counterpoints.

    Science.gov (United States)

    Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

    2016-01-01

    We recently conducted a retrospective analysis of data collected from 29 Tg.rasH2 carcinogenicity studies conducted at our facility to determine how successful was the strategy of choosing the high dose of the 26-week studies based on an estimated maximum tolerated dose (MTD). As a result of our publication, 2 counterviews were expressed. Both counterviews illustrate very valid points in their interpretation of our data. In this article, we would like to highlight clarifications based on several points and issues they have raised in their papers, namely, the dose-level selection, determining if MTD was exceeded in 26-week studies, and a discussion on the number of dose groups to be used in the studies. © The Author(s) 2015.

  3. Interactional justice at work is related to sickness absence: a study using repeated measures in the Swedish working population.

    Science.gov (United States)

    Leineweber, Constanze; Bernhard-Oettel, Claudia; Peristera, Paraskevi; Eib, Constanze; Nyberg, Anna; Westerlund, Hugo

    2017-12-08

    Research has shown that perceived unfairness contributes to higher rates of sickness absence. While shorter, but more frequent periods of sickness absence might be a possibility for the individual to get relief from high strain, long-term sickness absence might be a sign of more serious health problems. The Uncertainty Management Model suggests that justice is particularly important in times of uncertainty, e.g. perceived job insecurity. The present study investigated the association between interpersonal and informational justice at work with long and frequent sickness absence respectively, under conditions of job insecurity. Data were derived from the 2010, 2012, and 2014 biennial waves of the Swedish Longitudinal Occupational Survey of Health (SLOSH). The final analytic sample consisted of 19,493 individuals. We applied repeated measures regression analyses through generalized estimating equations (GEE), a method for longitudinal data that simultaneously analyses variables at different time points. We calculated risk of long and frequent sickness absence, respectively in relation to interpersonal and informational justice taking perceptions of job insecurity into account. We found informational and interpersonal justice to be associated with risk of long and frequent sickness absence independently of job insecurity and demographic variables. Results from autoregressive GEE provided some support for a causal relationship between justice perceptions and sickness absence. Contrary to expectations, we found no interaction between justice and job insecurity. Our results underline the need for fair and just treatment of employees irrespective of perceived job insecurity in order to keep the workforce healthy and to minimize lost work days due to sickness absence.

  4. First worldwide proficiency study on variable-number tandem-repeat typing of Mycobacterium tuberculosis complex strains.

    NARCIS (Netherlands)

    Beer, J.L. de; Kremer, K.; Kodmon, C.; Supply, P.; Soolingen, D. van

    2012-01-01

    Although variable-number tandem-repeat (VNTR) typing has gained recognition as the new standard for the DNA fingerprinting of Mycobacterium tuberculosis complex (MTBC) isolates, external quality control programs have not yet been developed. Therefore, we organized the first multicenter proficiency

  5. Design study on dose evaluation method for employees at severe accident

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Irie, Takashi; Kohriyama, Tamio; Kudo, Seiichi; Nishimura, Kazuya

    2002-01-01

    If a severe accident occurs in a pressurized water reactor plant, it is required to estimate dose values of operators engaged in emergency such as accident management, repair of failed parts. However, it might be difficult to measure radiation dose rate during the progress of an accident, because radiation monitors are not always installed in areas where the emergency activities are required. In this study, we analyzed the transport of radioactive materials in case of a severe accident, investigated a method to obtain radiation dose rate in the plant from estimated radioactive sources, made up a prototype analyzing system from this design study, and then evaluated its availability. As a result, we obtained the following: (1) A new dose evaluation method was established to predict the radiation dose rate at any point in the plant during a severe accident scenario. (2) This evaluation of total dose including access route and time for emergency activities is useful for estimating radiation dose limit for these employee actions. (3) The radiation dose rate map is effective for identifying high radiation areas and for choosing a route with lower radiation dose rate. (author)

  6. Phase I dose-finding study of cabazitaxel administered weekly in patients with advanced solid tumours

    International Nuclear Information System (INIS)

    Fumoleau, Pierre; Trigo, Jose Manuel; Isambert, Nicolas; Sémiond, Dorothée; Gupta, Sunil; Campone, Mario

    2013-01-01

    Cabazitaxel is approved in patients with metastatic hormone-refractory prostate cancer previously treated with a docetaxel-containing regimen. This study evaluated a weekly cabazitaxel dosing regimen. Primary objectives were to report dose-limiting toxicities (DLTs) and to determine the maximum tolerated dose (MTD). Efficacy, safety and pharmacokinetics were secondary objectives. Cabazitaxel was administered weekly (1-hour intravenous infusion at 1.5–12 mg/m2 doses) for the first 4 weeks of a 5-week cycle in patients with solid tumours. Monitoring of DLTs was used to determine the MTD and the recommended weekly dose. Thirty-one patients were enrolled. Two of six patients experienced DLTs at 12 mg/m 2 , which was declared the MTD. Gastrointestinal disorders were the most common adverse event. Eight patients developed neutropenia (three ≥ Grade 3); one occurrence of febrile neutropenia was reported. There were two partial responses (in breast cancer) and 13 patients had stable disease (median duration of 3.3 months). Increases in C max and AUC 0–t were dose proportional for the 6–12 mg/m 2 doses. The MTD of weekly cabazitaxel was 12 mg/m 2 and the recommended weekly dose was 10 mg/m 2 . The observed safety profile and antitumour activity of cabazitaxel were consistent with those observed with other taxanes in similar dosing regimens. The study was registered with ClinicalTrials.gov as http://www.clinicaltrials.gov/ct2/show/NCT01755390

  7. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    International Nuclear Information System (INIS)

    Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

    2011-01-01

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80–90). The mean retreatment dose was 84.4 Gy (range, 60–90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  8. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    Energy Technology Data Exchange (ETDEWEB)

    Aubuchon, Adam C., E-mail: acaubuchon@gmail.com [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Chan, Michael D. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Lovato, James F. [Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Balamucki, Christopher J. [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Ellis, Thomas L.; Tatter, Stephen B. [Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem, NC (United States); McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States)

    2011-11-15

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  9. Evaluation of the image quality criteria and study of doses in a mammography department

    International Nuclear Information System (INIS)

    Alcantara, Marcela Costa

    2009-01-01

    The mammographic image quality criteria published by European Commission were implemented in three mammography equipment of a same radiology department in a hospital of Sao Paulo city. Among the mammography equipment, two use the screen-film system and one of them uses the indirect digital system. During the data collection, it was noted the need to conduct a study about image rejection in each mammography equipment. Therefore, this study was realized and, after that, the results in each mammography equipment of image rejection and image percentage that present each quality criterion it were compared. At the same time of this studies, it was realized other study about surface entrance dose and average glandular dose. These doses it was estimated based on different methods published by different groups of researcher, for all combinations anode filter available in the equipment. To estimate the surface entrance dose following the methodology published in Avenue's' guide and the average glandular dose following the Wu' methodology, it was developed a phantom, in different thicknesses of acrylic, to simulate a breast. Finally, the image quality it was associated with the dose received by patient. The digital equipment shows better results in the evaluation of quality criteria, lower rate of image rejection and lower values of average glandular dose and surface entrance dose in all methods studied. But it is not sufficient, because is not adequate for patients with great breast. (author)

  10. Dose-effect studies with inhaled plutonium nitrate in dogs

    International Nuclear Information System (INIS)

    Dagle, G.E.; Cannon, W.C.; Case, A.C.; Madison, R.M.; McShane, J.F.; Stevens, D.L.; Rowe, S.E.; Ragan, H.A.; Schirmer, R.E.

    1980-01-01

    Beagle dogs given a single inhalation exposure to 239 Pu(NO 3 ) 4 , and observed for life-span dose-effect relationship, died from radiation pneumonitis (four of five at the highest dosage level, in 14 to 25 mo postexposure; 1 of 20 at the medium-high dosage level, at 34 mo postexposure). There were also indications in these dogs of radiation osteosis, characterized by peritrabecular fibrosis. One dog, at 39 mo postexposure, has radiographic evidence of an osteosarcoma. Leukopenia, lymphopenia, neutropenia and decreased numbers of circulating monocytes and eosinophils occurred at the two highest dosage levels, as previously reported (Annual Report, 1978). Twelve dogs given a single inhalation exposure to 238 Pu(NO 3 ) 4 showed a more rapid translocation of 238 Pu(NO 3 ) 4 to bone and liver than was observed for 239 Pu(NO 3 ) 4 , but at 1 yr postexposure the percentage of the final body burden in bone and liver were similar for the two isotopes

  11. Dose-effect studies with inhaled plutonium oxide in beagles

    International Nuclear Information System (INIS)

    Park, J.F.; Case, A.C.; Catt, D.L.

    1978-01-01

    Beagle dogs given a single exposure to 239 PuO 2 and 238 PuO 2 aerosols are being observed for life-span dose-effect relationships. The 239 Pu body burden of the nine dogs that died of pulmonary fibrosis-induced respiratory insufficiency during the first 3 yr after exposure was 1 to 12 μCi. One of these dogs had a pulmonary tumor; nine additional dogs with body burdens of 0.6 to 1.8 μCi died due to pulmonary neoplasia 3 to 6 yr after exposure. Two of the dogs exposed to 238 Pu have died during the first 4 yr postexposure, due to bone and lung tumors, with body burdens at death of 10 μCi. Lymphocytopenia was the earliest observed effect after inhalation of 239 PuO 2 or 238 PuO 2 , occurring 0.5 to 2 yr after deposition of equal to or greater than 80 nCi plutonium in the lungs

  12. Dose-effect studies with inhaled plutonium oxide in beagles

    International Nuclear Information System (INIS)

    Park, J.F.; Case, A.C.; Catt, D.L.

    1980-01-01

    Beagle dogs given a single exposure to 239 PuO 2 and 238 PuO 2 aerosols are being observed for life-span dose-effect relationships. The 239 Pu body burden of the nine dogs that died of pulmonary-fibrosis-induced respiratory insufficiency during the first 3 yr after exposure was 1 to 12 μCi; one of these dogs had a pulmonary tumor. Seventeen additional dogs, with body burdens of 0.2 to 1.8 μCi, died due to pulmonary neoplasia 3 to 8 yr after exposure. Ten of the dogs exposed to 238 Pu have died during the first 5 1/2 yr postexposure due to bone and/or lung tumors; the body burden at death ranged from 1.5 to 10 μCi. Lymphopenia was the earliest observed effect after inhalation of 239 PuO 2 or 238 PuO 2 , occurring 0.5 to 2 yr after deposition of >80 nCi plutonium in the lungs

  13. Dose-effect studies with inhaled plutonium oxide in beagles

    International Nuclear Information System (INIS)

    Park, J.F.; Busch, R.H.; Case, A.C.

    1979-01-01

    Beagle dogs given a single exposure to 239 PuO 2 and 238 PuO 2 aerosols are being observed for life-span dose-effect relationships. The 239 Pu body burden of the nine dogs that dies of pulmonary fibrosis-induced respiratory insufficiency during the first 3 yr after exposure was 1 to 12 μCi; one of these dogs had a pulmonary tumor. Eleven additional dogs with body burdens of 0.6 to 1.8 μCi died due to pulmonary neoplasia 3 to 7 yr after exposure. Four of the dogs exposed to 238 Pu have died during the first 4 1/2 yr postexposure due to bone and/or lung tumors; the body burden at death ranged from 6 to 10 μCi. Lymphopenia was the earliest observed effect after inhalation of 239 PuO 2 or 238 PuO 2 , occurring 0.5 to 2 yr after deposition of greater than or equal to 80 nCi plutonium in the lungs

  14. Study of the equivalent dose distribution in organs and tissues using periapical odontological radiography

    International Nuclear Information System (INIS)

    Santos, H.F.S.; Cipeli, J.F.; Fortes, M.A.B.; Federico, C.A.

    2017-01-01

    In this article presents a study of the doses obtained in periapical odontological radiography in main tissues of the head, using thermoluminescent dosemeters of type TLD-700H applied to a anthropomorphic simulator. The results indicate that the skin and salivary glands received the highest doses and the risk of calculated injury was 1.44 x 10 -6 Sv -1 per radiograph

  15. Dose Response Effects of Lisdexamfetamine Dimesylate Treatment in Adults with ADHD: An Exploratory Study

    Science.gov (United States)

    Faraone, Stephen V.; Spencer, Thomas J.; Kollins, Scott H.; Glatt, Stephen J.; Goodman, David

    2012-01-01

    Objective: To explore dose-response effects of lisdexamfetamine dimesylate (LDX) treatment for ADHD. Method: This was a 4-week, randomized, double-blinded, placebo-controlled, parallel-group, forced-dose titration study in adult participants, aged 18 to 55 years, meeting "Diagnostic and Statistical Manual of Mental Disorders" (4th ed., text rev.)…

  16. Absorbed dose/melting heat dependence studies for the PVDF homopolymer

    International Nuclear Information System (INIS)

    Batista, Adriana S.M.; Gual, Maritza R.; Pereira, Claubia

    2013-01-01

    Differential Scanning Calorimetry (DSC) of gamma irradiated Poly (vinylidene Fluoride) [PVDF] homopolymer has been studied in connection with the use of material in industrial high gamma dose measurement. Interaction between gamma radiation and PVDF leads to the radio-induction of C=O and conjugated C=C bonds, as it can be inferred from previous infrared (FTIR) and ultraviolet-visible (UV-Vis) spectrometric data. These induced defects result in a decrease of the polymer crystallinity that can be followed with DSC scans, by measuring the latent heat during the melting transition (Hmelt). After a systematic investigation, we have found that Hmelt is unambiguously related to the delivered doses ranging from 100 to 2,000 kGy of gamma radiation. One the other hand, further fading investigation analysis has proved that the Hmelt x Dose relationship can be fitted by an exponential function that remains constant for several months. Both the very large range of dose measurement and also the possibility of evaluating high gamma doses until five months after irradiation make PVDF homopolymers very good candidates to be investigated as commercial high gamma dose dosimeters. The high gamma dose irradiation facilities in Brazil used to develop high dose dosimeters are all devoted to industrial and medical purposes. Therefore, in view of the uncertainties involved in the dose measurements related to the electronic equilibrium correction factors and backscattering in the isodose curves used at the irradiation setup, a validation process is required to correctly evaluate the delivered absorbed doses. The sample irradiations were performed with a Co-60 source, at 12kGy/h and 2,592 kGy/h, in the high gamma dose facilities at Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil. The comparison of the curve of the Hmelt vs Dose is presented in this paper. (author)

  17. 3D calculation of absorbed dose for 131I-targeted radiotherapy: A Monte Carlo study

    International Nuclear Information System (INIS)

    Saeedzadeh, E.; Sarkar, S.; Abbaspour Tehrani-Fard, A.; Ay, M. R.; Khosravi, H. R.; Loudos, G.

    2008-01-01

    Various methods, such as those developed by the Medical Internal Radiation Dosimetry (MIRD) Committee of the Society of Nuclear Medicine or employing dose point kernels, have been applied to the radiation dosimetry of 131 I radionuclide therapy. However, studies have not shown a strong relationship between tumour absorbed dose and its overall therapeutic response, probably due in part to inaccuracies in activity and dose estimation. In the current study, the GATE Monte Carlo computer code was used to facilitate voxel-level radiation dosimetry for organ activities measured in an. 131 I-treated thyroid cancer patient. This approach allows incorporation of the size, shape and composition of organs (in the current study, in the Zubal anthropomorphic phantom) and intra-organ and intra-tumour inhomogeneities in the activity distributions. The total activities of the tumours and their heterogeneous distributions were measured from the SPECT images to calculate the dose maps. For investigating the effect of activity distribution on dose distribution, a hypothetical homogeneous distribution of the same total activity was considered in the tumours. It was observed that the tumour mean absorbed dose rates per unit cumulated activity were 0.65 E-5 and 0.61 E-5 mGY MBq -1 s -1 for the uniform and non-uniform distributions in the tumour, respectively, which do not differ considerably. However, the dose-volume histograms (DVH) show that the tumour non-uniform activity distribution decreases the absorbed dose to portions of the tumour volume. In such a case, it can be misleading to quote the mean or maximum absorbed dose, because overall response is likely limited by the tumour volume that receives low (i.e. non-cytocidal) doses. Three-dimensional radiation dosimetry, and calculation of tumour DVHs, may lead to the derivation of clinically reliable dose-response relationships and therefore may ultimately improve treatment planning as well as response assessment for radionuclide

  18. Multiple dose study of the combined radiosensitizers Ro 03-8799 (pimonidazole) and SR 2508 (etanidazole)

    International Nuclear Information System (INIS)

    Bleehen, N.M.; Newman, H.F.; Maughan, T.S.; Workman, P.

    1989-01-01

    The hypoxic cell radiosensitizers Ro 03-8799 and SR 2508 have different clinical toxicities. The former produces an acute but transient central nervous system syndrome, whereas the latter produces cumulative peripheral neuropathy. Following single dose studies, an escalating multiple dose schedule using both drugs in combination showed no unexpected adverse reactions at lower doses. This study identifies the clinical tolerance and pharmacokinetics when doses in the region of the maximal tolerated dose are given to 26 patients receiving infusions of 0.75 g/m2 Ro 03-8799 and 2 g/m2 SR 2508 three times per week. At 15 doses, 3/4 patients experienced WHO grade 2 peripheral neuropathy, whereas at 12 doses 1/9 developed grade 2 and 6/9 developed grade 1 neuropathies. This represents a lower dose of SR 2508 than can be given alone suggesting that some interaction between the two drugs does exist in terms of chronic peripheral neurotoxicity. Pharmacokinetic studies show no adverse interactions between the two drugs and minimal inter-patient variation. From bivariate analysis, cumulative AUC for Ro 03-8799 has the most significant correlation with the development of peripheral neuropathy. Tumor drug concentrations normalized to the administered dose show mean values of 34 micrograms/g Ro 03-8799 and 76 micrograms/g SR 2508 30 minutes after infusion. These could be expected to produce a single dose sensitizer enhancement ratio of 1.5. The combination of the two sensitizers at the maximum tolerable dose may be expected to give an increased therapeutic efficacy over either drug alone

  19. Studies of health effects of low dose radiation and its application to medicare

    International Nuclear Information System (INIS)

    Yamaoka, Kiyonori; Ishida, Kenji; Iwasaki, Toshiyasu; Koana, Takao; Magae, Junji; Watanabe, Masami; Sakamoto, Kiyohiko

    2008-01-01

    The articles contain following 7 topics of low dose radiation effects. Studies of Health Effects of Low dose Radiation and Its Application to Medicare'', describes the indication of Rn therapy and investigations of its usefulness mechanism mainly in Misasa Spa, Okayama Pref. ''Challenges for the Paradigm Shift (CRIEPI Studies)'', introduces studies against the paradigm that radiation dose is linearly and proportionally hazardous. ''Studies of High Background Radiation Area (CRIEPI Studies)'', describes global HBRA studies on chromosome affection and effect of smoking in HBRA. ''Is the Radiation Effect on Man Proportional to Dose? (CRIEPI Studies)'', describes studies of immature sperm irradiated at low dose against Linear-Non-threshold Theory (LNT) hypothesis. ''Induction of Radiation Resistance by Low Dose Radiation and Assessment of Its Effect in Models of Human Diseases (CRIEPI Studies)'', explains the adoptive response in radiation effect, suppression of carcinogenesis and immune regulation by previous low dose radiation in the mouse, and improvement of diabetes in the db/db mouse. ''Modulation of Biological Effects of Low Dose Radiation: Adoptive Response, Bystander Effect, Genetic Instability and Radiation Hormesis'', summarizes findings of each item. ''Cancer Treatment with Low dose Radiation to the Whole Body'', describes basic studies in the mouse tumor in relation to suppression of carcinogenesis and metastasis, immune activation and treatment, and successful clinical studies in patients with ovary, colon cancers and malignant lymphoma where survival has been significantly improved: a base of recent European Organization for Research and Treatment of Cancer (EORTC) clinical trials. The mechanism is essentially based on immune activation of patients to cure the disease. (R.T.)

  20. Limiting CT radiation dose in children with craniosynostosis: phantom study using model-based iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Kaasalainen, Touko; Lampinen, Anniina [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); University of Helsinki, Department of Physics, Helsinki (Finland); Palmu, Kirsi [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); School of Science, Aalto University, Department of Biomedical Engineering and Computational Science, Helsinki (Finland); Reijonen, Vappu; Kortesniemi, Mika [University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Center, Radiology, POB 340, Helsinki (Finland); Leikola, Junnu [University of Helsinki and Helsinki University Hospital, Department of Plastic Surgery, Helsinki (Finland); Kivisaari, Riku [University of Helsinki and Helsinki University Hospital, Department of Neurosurgery, Helsinki (Finland)

    2015-09-15

    Medical professionals need to exercise particular caution when developing CT scanning protocols for children who require multiple CT studies, such as those with craniosynostosis. To evaluate the utility of ultra-low-dose CT protocols with model-based iterative reconstruction techniques for craniosynostosis imaging. We scanned two pediatric anthropomorphic phantoms with a 64-slice CT scanner using different low-dose protocols for craniosynostosis. We measured organ doses in the head region with metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters. Numerical simulations served to estimate organ and effective doses. We objectively and subjectively evaluated the quality of images produced by adaptive statistical iterative reconstruction (ASiR) 30%, ASiR 50% and Veo (all by GE Healthcare, Waukesha, WI). Image noise and contrast were determined for different tissues. Mean organ dose with the newborn phantom was decreased up to 83% compared to the routine protocol when using ultra-low-dose scanning settings. Similarly, for the 5-year phantom the greatest radiation dose reduction was 88%. The numerical simulations supported the findings with MOSFET measurements. The image quality remained adequate with Veo reconstruction, even at the lowest dose level. Craniosynostosis CT with model-based iterative reconstruction could be performed with a 20-μSv effective dose, corresponding to the radiation exposure of plain skull radiography, without compromising required image quality. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-11-01

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

  2. Action of 50 R X-ray doses on the breeding function of C3H strain mice - effect of splitting the dose, action of repeated irradiations on successive generations; Action de 50 R de rayons X sur la fonction de reproduction des souris de race C3H - influence du fractionnement. Action de la repetition des irradiations au cours des generations successives

    Energy Technology Data Exchange (ETDEWEB)

    Alix, D [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-07-01

    X-rays exposure effect was studied on C3H strain mice, at the standpoint of the effects produced on breeding function. The method used with this purpose was the following: single doses 20 - 30 - 40 and 50 R/dose, fractional doses: 50 R/total dose, divided in 2 - 5 - 10 or 25 irradiations distributed in one month duration. The offsprings were irradiated at the same doses than the parents, consanguinity being maintained. Statistical treatment of results was carried out, that led at the following conclusions: 1) Couples receiving single exposure of 50 R or two exposures of 25 R at one month interval give comparable results. Fractional doses do not involve the slightest diminution of X-rays effect. 2) 30 R exposure brings about a decrease in fertility, with an increase in abortions. Fertility of 20 R irradiated couples remains below controls. 3) After ten times 5 R and twenty-five 2 R, the number of abortions is the largest. Ovarian function is particularly sensitive to X-rays; one may think that twenty-five 2 R give injuries conditioning non-viability of conception products, smaller doses should produce mutations and yield births of altered genotype individuals. (author) [French] L'action d'une exposition aux rayons X de souris de race C3H a ete etudiee du point de vue des effets produits sur la fonction reproductrice. La methode utilisee fut la suivante: doses administrees en irradiation unique: 20 - 30 - 40 et 50 R/seance, en irradiations fractionnees: 50 R au total en 2 - 5 - 10 ou 25 seances reparties en un mois. Les descendants ont ete irradies aux memes doses que leurs parents, en maintenant la consanguinite. Un traitement statistique des resultats a ete effectue dont on a pu conclure : 1) Chez les couples ayant recu une seule exposition de 50 R ou deux expositions de 25 R a intervalle d'un mois les resultats sont comparables. Le fractionnement n' entrainant aucune attenuation de l'action des rayons X. 2) Une exposition de 30 R entraine une baisse de fecondite

  3. Studies of dose optimization and image quality in technological transition in mammography; Estudos de otimizacao de dose e qualidade de imagem em processos de transicao tecnologica em mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Furquim, Tania C.; Nersissian, Denise Y., E-mail: tfurquim@iee.usp.b [Universidade de Sao Paulo (IEE/USP), SP (Brazil). Inst. de Eletrotecnica e Energia

    2011-07-01

    The introduction of new technologies in mammography may improve image quality; however, it may unnecessarily increase doses if optimization processes are not studied. In this work, radiation doses of the moment of transition of conventional to digital mammography have been analyzed. The presented data have been acquired from 2005 to 2009, in hospitals and clinics of Sao Paulo city, to 4 conventional and 5 digital equipment. The results show that even after optimization processes, new technologies still impart higher doses. Thus, individualized studies are needed when technological transitions occur, in order to maintain image quality without significant dose increase. (author)

  4. Chlamydia screening is not cost-effective at low participation rates: evidence from a repeated register-based implementation study in The Netherlands

    NARCIS (Netherlands)

    de Wit, G. Ardine; Over, Eelco A. B.; Schmid, Boris V.; van Bergen, Jan E. A. M.; van den Broek, Ingrid V. F.; van der Sande, Marianne A. B.; Welte, Robert; Op de Coul, Eline L. M.; Kretzschmar, Mirjam E.

    2015-01-01

    In three pilot regions of The Netherlands, all 16-29 year olds were invited to participate in three annual rounds of Chlamydia screening. The aim of the present study is to evaluate the cost-effectiveness of repeated Chlamydia screening, based on empirical data. A mathematical model was employed to

  5. Secondhand tobacco smoke exposure and heart rate variability and inflammation among non-smoking construction workers: a repeated measures study.

    Science.gov (United States)

    Zhang, Jinming; Fang, Shona C; Mittleman, Murray A; Christiani, David C; Cavallari, Jennifer M

    2013-10-02

    Although it has been well recognized that exposure to secondhand tobacco smoke (SHS) is associated with cardiovascular mortality, the mechanisms and time course by which SHS exposure may lead to cardiovascular effects are still being explored. Non-smoking workers were recruited from a local union and monitored inside a union hall while exposed to SHS over approximately 6 hours. Participants were fitted with a continuous electrocardiographic monitor upon enrollment which was removed at the end of a 24-hr monitoring period. A repeated measures study design was used where resting ECGs and blood samples were taken from individuals before SHS exposure (baseline), immediately following SHS exposure (post) and the morning following SHS exposure (next-morning).Inflammatory markers, including high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were analyzed. Heart rate variability (HRV) was analyzed from the ECG recordings in time (SDNN, rMSSD) and frequency (LF, HF) domain parameters over 5-minute periods. SHS exposure was quantified using a personal fine particulate matter (PM2.5) monitor.Linear mixed effects regression models were used to examine within-person changes in inflammatory and HRV parameters across the 3 time periods. Exposure-response relationships with PM2.5 were examined using mixed effects models. All models were adjusted for age, BMI and circadian variation. A total of 32 male non-smokers were monitored between June 2010 and June 2012. The mean PM2.5 from SHS exposure was 132 μg/m3. Immediately following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with declines in HRV (7.8% [standard error (SE) =3%] SDNN, 8.0% (SE = 3.9%) rMSSD, 17.2% (SE = 6.3%) LF, 29.0% (SE = 10.1%) HF) and increases in WBC count 0.42 (SE = 0.14) k/μl. Eighteen hours following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with 24.2% higher CRP levels. Our study suggest that short-term SHS exposure is associated

  6. Ambient temperature and cardiovascular biomarkers in a repeated-measure study in healthy adults: A novel biomarker index approach.

    Science.gov (United States)

    Wu, Shaowei; Yang, Di; Pan, Lu; Shan, Jiao; Li, Hongyu; Wei, Hongying; Wang, Bin; Huang, Jing; Baccarelli, Andrea A; Shima, Masayuki; Deng, Furong; Guo, Xinbiao

    2017-07-01

    Associations of ambient temperature with cardiovascular morbidity and mortality have been well documented in numerous epidemiological studies, but the underlying pathways remain unclear. We investigated whether systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function may be the mechanistic pathways associated with ambient temperature. Forty study participants underwent repeated blood collections for 12 times in Beijing, China in 2010-2011. Ambient temperature and air pollution data were measured in central monitors close to student residences. We created five indices as the sum of weighted biomarker percentiles to represent the overall levels of 15 cardiovascular biomarkers in five pathways (systemic inflammation: hs-CRP, TNF-α and fibrinogen; coagulation: fibrinogen, PAI-1, tPA, vWF and sP-selectin; systemic oxidative stress: Ox-LDL and sCD36: antioxidant activity: EC-SOD and GPX1; and endothelial function: ET-1, E-selectin, ICAM-1 and VCAM-1). We used generalized mixed-effects models to estimate temperature effects controlling for air pollution and other covariates. There were significant decreasing trends in the adjusted means of biomarker indices over the lowest to the highest quartiles of daily temperatures before blood collection. A 10°C decrease at 2-d average daily temperature were associated with increases of 2.5% [95% confidence interval (CI): 0.7, 4.2], 1.6% (95% CI: 0.1, 3.1), 2.7% (95% CI: 0.5, 4.8), 5.5% (95% CI: 3.8, 7.3) and 2.0% (95% CI: 0.3, 3.8) in the indices for systemic inflammation, coagulation, systemic oxidative stress, antioxidant activity and endothelial function, respectively. In contrast, the associations between ambient temperature and individual biomarkers had substantial variation in magnitude and strength. The altered cardiovascular biomarker profiles in healthy adults associated with ambient temperature changes may help explain the temperature-related cardiovascular morbidity

  7. Reported frequency of physical activity in a large epidemiological study: relationship to specific activities and repeatability over time

    Directory of Open Access Journals (Sweden)

    Reeves Gillian K

    2011-06-01

    Full Text Available Abstract Background How overall physical activity relates to specific activities and how reported activity changes over time may influence interpretation of observed associations between physical activity and health. We examine the relationships between various physical activities self-reported at different times in a large cohort study of middle-aged UK women. Methods At recruitment, Million Women Study participants completed a baseline questionnaire including questions on frequency of strenuous and of any physical activity. About 3 years later 589,896 women also completed a follow-up questionnaire reporting the hours they spent on a range of specific activities. Time spent on each activity was used to estimate the associated excess metabolic equivalent hours (MET-hours and this value was compared across categories of physical activity reported at recruitment. Additionally, 18,655 women completed the baseline questionnaire twice, at intervals of up to 4 years; repeatability over time was assessed using the weighted kappa coefficient (κweighted and absolute percentage agreement. Results The average number of hours per week women reported doing specific activities was 14.0 for housework, 4.5 for walking, 3.0 for gardening, 0.2 for cycling, and 1.4 for all strenuous activity. Time spent and the estimated excess MET-hours associated with each activity increased with increasing frequency of any or strenuous physical activity reported at baseline (tests for trend, P weighted = 0.71 for questionnaires administered less than 6 months apart, and 52% (κweighted = 0.51 for questionnaires more than 2 years apart. Corresponding values for any physical activity were 57% (κweighted = 0.67 and 47% (κweighted = 0.58. Conclusions In this cohort, responses to simple questions on the frequency of any physical activity and of strenuous activity asked at baseline were associated with hours spent on specific activities and the associated estimated excess MET

  8. New method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. Clinical and hormonal studies

    Energy Technology Data Exchange (ETDEWEB)

    Gronroos, M.; Turunen, T.; Raekallio, J.; Ruotsalinen, P.; Salmi, T. (Turku Univ. (Finland). Dept. of Obstetrics and Gynecology)

    1982-08-01

    The authors present a new method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. The problem with this method has been how to inactivate the endometrium while maintaining the physiological function of the ovaries. In 5/29 young patients regular or irregular bleedings occurred after an endometrial dose of 11+-1 Gy. These subjects were given a repeat low dose intrauterine irradiation. Thereafter no bleedings were found in four out of five patients. Two to 9 years after the repeat irradiation the plasma levels of E/sub 1/, E/sub 2/, FSH and LH corresponded closely to those of healthy women in reproductive age in three out of five patients; some high plasma P levels indicated ovulation. In two patients the E/sub 1/, E/sub 2/, and P values were more likely postmenopausal but, on the other hand, FSH and LH values reproductive ones. 19 refs.

  9. A new method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. Clinical and hormonal studies

    International Nuclear Information System (INIS)

    Gronroos, M.; Turunen, T.; Raekallio, J.; Ruotsalinen, P.; Salmi, T.

    1982-01-01

    The authors present a new method for the induction of therapeutic amenorrhea: low dose endometrial afterloading irradiation. The problem with this method has been how to inactivate the endometrium while maintaining the physiological function of the ovaries. In 5/29 young patients regular or irregular bleedings occurred after an endometrial dose of 11+-1 Gy. These subjects were given a repeat low dose intrauterine irradiation. Thereafter no bleedings were found in four out of five patients. Two to 9 years after the repeat irradiation the plasma levels of E 1 , E 2 , FSH and LH corresponded closely to those of healthy women in reproductive age in three out of five patients; some high plasma P levels indicated ovulation. In two patients the E 1 , E 2 , and P values were more likely postmenopausal but, on the other hand, FSH and LH values reproductive ones. (author)

  10. A phase I dose-finding study of 5-azacytidine in combination with sodium phenylbutyrate in patients with refractory solid tumors.

    Science.gov (United States)

    Lin, Jianqing; Gilbert, Jill; Rudek, Michelle A; Zwiebel, James A; Gore, Steve; Jiemjit, Anchalee; Zhao, Ming; Baker, Sharyn D; Ambinder, Richard F; Herman, James G; Donehower, Ross C; Carducci, Michael A

    2009-10-01

    This was a phase I trial to determine the minimal effective dose and optimal dose schedule for 5-azacytidine (5-AC) in combination with sodium phenylbutyrate in patients with refractory solid tumors. The pharmacokinetics, pharmacodynamics, and antineoplastic effects were also studied. Three dosing regimens were studied in 27 patients with advanced solid tumors, and toxicity was recorded. The pharmacokinetics of the combination of drugs was evaluated. Repeat tumor biopsies and peripheral blood mononuclear cells (PBMC) were analyzed to evaluate epigenetic changes in response to therapy. EBV titers were evaluated as a surrogate measure for gene re-expression of epigenetic modulation in PBMC. The three dose regimens of 5-AC and phenylbutyrate were generally well tolerated and safe. A total of 48 cycles was administrated to 27 patients. The most common toxicities were bone marrow suppression-related neutropenia and anemia, which were minor. The clinical response rate was disappointing for the combination of agents. One patient showed stable disease for 5 months whereas 26 patients showed progressive disease as the best tumor response. The administration of phenylbutyrate and 5-AC did not seem to alter the pharmacokinetics of either drug. Although there were individual cases of targeted DNA methyltransferase activity and histone H3/4 acetylation changes from paired biopsy or PBMC, no conclusive statement can be made based on these limited correlative studies. The combination of 5-AC and phenylbutyrate across three dose schedules was generally well tolerated and safe, yet lacked any real evidence for clinical benefit.

  11. Repeated radiation injuries by fission products

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.

    1986-01-01

    Attention is given to repeated radiation injuries during internal irradiation of theoretical and practical interest, particularly in case of the intake into organism of young products of nuclear fission (PNF). The results of experiments with dogs with repeated radioactive iodine injury the isotopes of which (131-135sub(I)) constitute a considerable part of PNF activity are discussed. The blood reaction and protein metabolism state have been studied. Observations for dogs have been continued for about 4 years. The doses for thyroid, gastrointestinal tract and liver subjected to the most intensive irradiation consituted in the first series of experiments after the first intake about 3;0.3;0.05 Gy, after the second - 5;0.5;0.08 Gy and in the second series of experiments - 3;0.3;0.05 Gy and 0.6;0.06;0.01 Gy, respectively. Hematologic factors,thyroid function, changes in exchange and immunologic reactivity have been studied. The dogs have been under observation for 5 years. It is shown in case of repeated intake of Isup(131) PNF into animals organism in quantity which does not cause during the acute period a clinically outlined sickness, substantial differences in the organism reaction as compared with the first intake of radionuclides have not been found. The presence of residual radiation injuries did not cause charging action during the acute period during PNF and repeated intake which in the author's opinion testifies to perfection of compensator mechanisms in case of intake of such quantities of radioactive products. At the remote periods blastomogenic action manifested which is estimated as a result of general biological action of radionuclides administered to the organism. The necessity in subsequent investigations for obtaining the data on organism reactivity, clinic and pathogenesis with the aim of prophylaxis and treatment of such injuries is indicated

  12. Study of radiation dose reduction of buildings of different sizes and materials

    International Nuclear Information System (INIS)

    Furuta, Takuya; Takahashi, Fumiaki

    2015-01-01

    The dependence of radiation dose reduction on the sizes and materials of buildings was studied by numerical analyses using the Monte Carlo simulation code, PHITS. The dose rates inside the buildings were calculated by simulating gamma-ray transport from radioactive cesium deposited at the ground surface. Three building models were developed: the wooden house, the open-space concrete building, and the thin-wall building, to study the effect of building size and construction material on dose reduction inside these structures. Here the floor-area sizes of the building models were varied to clarify the influence of building configuration on dose reduction. The results demonstrated that the dose rates inside the buildings linearly decreased with increasing floor area on a logarithmic scale for all types of buildings considered. The calculated dose distribution inside a building indicated that the distance from the outer walls was a determining factor for the dose rate at each position in the building. The obtained tendency was verified by comparison with data reflecting the dose reduction of typical buildings in Japan. (author)

  13. Study of the CT peripheral dose variation in a head phantom

    International Nuclear Information System (INIS)

    Mourao, Arnaldo P.

    2009-01-01

    The computed tomography is frequently used for the brain diagnosis and it is responsible for the largest doses in the head among the X-ray examinations. Established indexes define a reference dose value for a scan routine; however the dose value has a longitudinal variation in the scan. The purpose of this study is to investigate the variation of the peripheral doses in the head scan using a polymethylmethacrylate head phantom. The studies were performed using two different computed tomography scanners in the option single slice with a routine of a head adult protocol (i.e. default protocol in the scanner software). Radiation doses were measured using thermoluminescent dosimeter (LiF - TLD) rod model, distributed inside the PMMA head phantom in periphery and central area. The results allowed registering the variation dose curve, longitudinally the scan, for the peripheral area and to determine the MSAD value. The peripheral maximum dose value measured can be compared with the maximum dose value in the center of the phantom in each different routine (author)

  14. Study the Stability of SSR Repeats of pEA29 Plasmid of the Casual Agent of Fire Blight

    Directory of Open Access Journals (Sweden)

    S. Baghaee Ravari

    2016-02-01

    Full Text Available Introduction Fire blight disease causes by Erwinia amylovora infects a wide variety of rosaceous plants. It was first recorded from pear trees in Karaj in year 1990. After that it was observed in many pear and apple orchards of the country. E. amylovora isolates differed slightly in virulence, symptoms and host range which ca be related to different plasmid content. The presence of an universal plasmid, pEA29, has been observed in majority of E. amylovora strains. Short-sequence DNA repeat with eight nt were repeated 3 to 15 times in the PstI fragment of the pEA29 plasmid. Here, the stability of SSR units and efficiency of this method to categorize strains was checked. For this reseaon two methods including amplification and cloning of whole and part of PstI fragment was done and the sequences were compared to eachother. In addition stability was evaluated based on three treatments including long time propagation, keeping strains in cold situation and re-isolation of infected tissues. Materials and Methods In this study 20 strains were purchased from the Iranian Plant Protection Research Institute. Their typical phenotypic tests were examined for all strains. All of then were checked with lateral flow immune chromatography in different serial dilutions. The pathogenicity were aassayed using complete fruit. Direct PCR with A/B primers and nested PCR with AJ75/AJ76 were applied for studied strains. Ten representative strains were selected snf part of PstI fragment amplified using RS1/RS2 primers. The PCR products were purified by QIAquick PCR purification kit (Qiagen, USA, cloned in pGEM-T and were sequenced (Macrogen Inc., Korea. Five of 10 were chosen for stability tests including long time propagation and sub culturing each two week for three months, keeping strains in refrigerator for three months and re-isolation of infected tissues. Results and Discussion In phenotypic tests all studies strains were facultative anaerobic growth, oxidase

  15. Acute caffeine effect on repeatedly measured P300

    OpenAIRE

    Pan, Jingbo; Takeshita, Tatsuya; Morimoto, Kanehisa

    2000-01-01

    The acute effect of a single-dose of caffeine on the P300 event-related brain potential (ERP) was assessed in a study using a repeatedly presented auditory oddball button-press task. A dose (5mg/kg body-weight) of either caffeine or placebo lactose, dissolved in a cup of decaffeinated coffee, was administered double-blindly to coffee drinkers who had abstained from coffee for 24hrs, with the presentation order of the sessions counterbalanced and separated by 2–4 weeks. The caffeine-treatment ...

  16. Mortality of rats under repeated +Gz acceleration in the course of radiation sickness

    International Nuclear Information System (INIS)

    Rudnicki, T.

    1985-01-01

    The influence of repeated +10G z acceleration on the mortality of rats after acute total-body irradiation was studied. No conclusive evidence was found to the effect that daily repeated exposures to 5 or 7.5 min of +10G z inertial forces essentially influence the mortality of rats after acute irradiation in the dose range 0.206-0.309 C/kg. 7 refs. (author)

  17. Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy

    International Nuclear Information System (INIS)

    Beierholm, A.R.; Behrens, C.F.; Andersen, C.E.

    2015-01-01

    Modern megavoltage x-ray radiotherapy with high spatial and temporal dose gradients puts high demands on the entire delivery system, including not just the linear accelerator and the multi-leaf collimator, but also algorithms used for optimization and dose calculations, and detectors used for quality assurance and dose verification. In this context, traceable in-phantom dosimetry using a well-characterized point detector is often an important supplement to 2D-based quality assurance methods based on radiochromic film or detector arrays. In this study, an in-house developed dosimetry system based on fiber-coupled plastic scintillator detectors was evaluated and compared with a Farmer-type ionization chamber and a small-volume ionization chamber. An important feature of scintillator detectors is that the sensitive volume of the detector can easily be scaled, and five scintillator detectors of different scintillator length were thus employed to quantify volume averaging effects by direct measurement. The dosimetric evaluation comprised several complex-shape static fields as well as simplified dynamic deliveries using RapidArc, a volumetric-modulated arc therapy modality often used at the participating clinic. The static field experiments showed that the smallest scintillator detectors were in the best agreement with dose calculations, while needing the smallest volume averaging corrections. Concerning total dose measured during RapidArc, all detectors agreed with dose calculations within 1.1 ± 0.7% when positioned in regions of high homogenous dose. Larger differences were observed for high dose gradient and organ at risk locations, were differences between measured and calculated dose were as large as 8.0 ± 5.5%. The smallest differences were generally seen for the small-volume ionization chamber and the smallest scintillators. The time-resolved RapidArc dose profiles revealed volume-dependent discrepancies between scintillator and ionization chamber response

  18. Dose Prediction for surface nuclear explosions: case studies for Semipalatinsk and Lop Nur tests

    International Nuclear Information System (INIS)

    Takada, Jun

    2008-01-01

    Dose prediction method RAPS after surface nuclear explosion has been developed by using the empirical dose function of USA nuclear test. This method which provides us external total dose, dose rate at any distant, at any time for any yield of nuclear explosion, is useful for radiation protection in case of nuclear events such as terrorism and nuclear war. The validity of RAPS has been confirmed by application to historical surface nuclear test explosions. The first test case study which was done for the first test explosion of the former USSR at the Semipalatinsk Nuclear Test Site on August 29th 1949, shows a good agreement with luminescence dosimetry on a brick. This dose prediction method was applied nuclear tests in Lop Nur. The results indicate dangerous nuclear radiation influences including fatal risk in the wide Uygur area. (author)

  19. Feasibility study for the assessment of the exposed dose with TENORM added in consumer products

    International Nuclear Information System (INIS)

    Yoo, Do Hyeon; Lee, Hyun Cheol; Shin, Wook-Geun; Min, Chul Hee; Ha, Wi-Ho; Yoo, Jae Ryong; Yoon, Seok-Won; Lee, Jiyon; Choi, Won-Chul

    2015-01-01

    Consumer products including naturally occurring radioactive material have been distributed widely in human life. The potential hazard of the excessively added technically enhanced naturally occurring radioactive material (TENORM) in consumer products should be assessed. The aim of this study is to evaluate the organ equivalent dose and the annual effective dose with the usage of the TENORM added in paints. The activities of gammas emitted from natural radionuclides in the five types of paints were measured with the high-purity germanium detector, and the annual effective dose was assessed with the computational human phantom and the Monte Carlo method. The results show that uranium and thorium series were mainly measured over the five paints. Based on the exposure scenario of the paints in the room, the highest effective dose was evaluated as <1 mSv y -1 of the public dose limit. (authors)

  20. Study of a new glass matrix by thermoluminescent technique for high-dose dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Pamela Z.; Carvalho, Gabriel S. Marchiori de; Cunha, Diego M. da; Dantas, Noelio O.; Silva, Anielle C.A.; Neves, Lucio P.; Perini, Ana P., E-mail: anapaula.perini@ufu.br [Universidade Federal de Uberlandia (UFU), MG (Brazil). Instituto de Fisica; Linda, V.E. Caldas [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Carrera, Betzabel N.S.; Watanab