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Sample records for high dose male

  1. Low-Active Male Adolescents: A Dose Response to High-Intensity Interval Training.

    Science.gov (United States)

    Logan, Greig Robert Melrose; Harris, Nigel; Duncan, Scott; Plank, Lindsay D; Merien, Fabrice; Schofield, Grant

    2016-03-01

    High-intensity interval training (HIIT) is a potential alternative to traditionally recommended steady state exercise for providing health benefits in adolescents, yet its dose-response relationship in this cohort remains unclear, as does its translatability to real-world, nonclinical settings. The present study adopts a novel dose-response design to investigate the effects of undertaking 8 wk of HIIT on the cardiometabolic health of low-active male adolescents. Twenty-six male adolescents (age 16 ± 1 yr), identified as low active by nonparticipation in structured sport and physical education classes, were randomly assigned to one of five treatment groups. Corresponding with their group numbers (1-5), participants completed a number of HIIT "sets," which consisted of 4 repeated bouts of 20-s near-maximal exertion interspersed with 10-s passive recovery. Participants performed two HIIT sessions and one resistance training session each week for 8 wk. Baseline and follow-up health measures consisted of peak oxygen uptake (V˙O2peak) with an incremental ramp test to volitional exhaustion; body composition (including visceral fat mass, body fat, and lean tissue mass) with dual-energy x-ray absorptiometry; and lipid profile, glucose, insulin, and interleukin-6 from blood analysis. All health outcomes were analyzed as percentage changes, and data were modeled using a quadratic function to explore dose-response relationships. Significant improvements were observed for V˙O2peak (∼6%), body fat percentage (∼4%), visceral fat mass (∼10%), and waist circumference-to-height ratio (∼3%), but there was no clear effect of dose across groups. Low-active adolescent males performing a single HIIT set twice weekly, in addition to one resistance training session, gained meaningful improvements in fitness and body composition. Performing additional HIIT sets provided no additional improvements to those of the lowest dose in this study.

  2. Cyp1a1(-/-) male mice: protection against high-dose TCDD-induced lethality and wasting syndrome, and resistance to intrahepatocyte lipid accumulation and uroporphyria

    International Nuclear Information System (INIS)

    Uno, Shigeyuki; Dalton, Timothy P.; Sinclair, Peter R.; Gorman, Nadia; Wang, Bin; Smith, Andrew G.; Miller, Marian L.; Shertzer, Howard G.; Nebert, Daniel W.

    2004-01-01

    To study liver toxicity and uroporphyrin (URO) accumulation and urinary excretion, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent ligand for the aryl hydrocarbon receptor (AHR), is often used as the prototype. In this study, we asked the question how important is the role of CYP1A1 in causing TCDD toxicity. Using a single large intraperitoneal dose of TCDD (200 μg/kg) and following the response over an 8-week period, we found this dose: (a) was lethal in less than 4 weeks to Cyp1a1(+/+) males but not to Cyp1a1(-/-) males or to females of either genotype; (b) caused a wasting syndrome in Cyp1a1(+/+) but not Cyp1a1(-/-) mice; (c) resulted in thymic atrophy, regardless of gender or genotype; (d) decreased spleen size and caused leukocytopenia in males but not females of either genotype; (e) caused hepatocyte hypertrophy in Cyp1a1(+/+) more so than in Cyp1a1(-/-) mice; (f) increased intrahepatocyte lipids and total liver fat content in Cyp1a1(+/+) more than Cyp1a1(-/-) males and females; and (g) caused uroporphyria in Cyp1a1(+/+) males much more than Cyp1a1(+/+) females, or in Cyp1a1(-/-) mice. Contrary to Cyp1a2(-/-) knockout mice that exhibited 15 times less accumulation of TCDD in liver than Cyp1a1/1a2(+/+) wild-type mice, Cyp1a1(-/-) mice did not show this altered TCDD distribution - indicating that CYP1A2 but not CYP1A1 is the major hepatic TCDD-binding 'sink'. Our data demonstrate that CYP1A1 contributes to high-dose TCDD-induced toxicity, uroporphyria, and lethality

  3. The ultrastructural changes in the liver cells induced by high doses of Benzodiazepine Tranquilizing drugs: An experimental transmission electron microscopic study on male guinea pigs

    International Nuclear Information System (INIS)

    Bisher, Ameen S. Ahmad

    2008-01-01

    Benzodiazepines are tranquilizing psychotropic drugs. Unfortunately, despite their therapeutic benefits, they are illegally consumed in high doses by some addicts to reach a sedative, exhilarative and euphoria state similar to that produced by narcotic substances. The present study, using transmission electron microscope on male guinea pigs, aims to investigate the potential ultrastructural changes in the liver cells induced by the high doses of Benzodiazepines. Animals in three treated groups administrated a daily combined dose consisted of (10mg Alprazolam with 10mg Diazepam/day/animal) for three different treatment periods: 7, 15, and 25 days. The ultrastructural examination of the hepatocytes of the animals treated for 15 days showed limited changes in the form of marginal heterochromatine accompanied with marginal nucleoli enlargement. On the other hand, severe ultrastructural damages are observed in the animals treated for 25 days, which appeared in the following various patterns: fatty degeneration of the hepatocytes as indicated by the accumulation of large number of lipid droplets in the cytoplasm, marked nuclear atrophy in some necrotic hepatocytes, massive nuclear degeneration in other hepatocytes, mitochondrial damages in the form of cristea destruction accompanied with abnormal oval shape, massive lysis of the cytoplasmic organelles with severe plasma membrane rupture. In conclusion, the observed ultrastructural damages in the present study may refer to the potential hepatotoxic effects of the high dose of Benzodiazepins. It is recommended that much more official restrictions should be applied on the pharmacies sector to prevent any illegal selling of these drugs in order to prevent abusers from obtaining them, as unfortunately in some developing countries the illegal selling of these drugs is known to occur due to the absence of official control. (author)

  4. Swim Training Improves HOMA-IR in Type 2 Diabetes Induced by High Fat Diet and Low Dose of Streptozotocin in Male Rats.

    Science.gov (United States)

    Ghiasi, Rafigheh; Ghadiri Soufi, Farhad; Somi, Mohammad Hossein; Mohaddes, Gisou; Mirzaie Bavil, Fariba; Naderi, Roya; Alipour, Mohammad Reza

    2015-09-01

    Insulin resistance plays a key role in the onset and development of type 2 diabetes mellitus (T2DM) and its complications. In this study, we evaluated the effect of swim training on insulin resistance in diabetic rats. Forty male Wistar rats were randomly divided into four groups (n=10): sedentary control (Con), sedentary diabetic (Dia), swim trained control (Exe) and swim trained diabetic (Dia+Exe) rats. Diabetes was induced by high fat diet (HFD) and a low dose of streptozotocin (35 mg/kg, i.p). In trained groups, one week after the induction of diabetes, animals were subjected to swimming (60 min/5 days a week) for 10 weeks. At the end of training, fasting blood sugar (FBS), oral glucose tolerance test (OGTT), fasting/basal insulin, glycosylated hemoglobin (HbA1c) levels, insulin resistance index, homeostasis model assessment method (HOMA-IR), triglycerides (TG,) total cholesterol (TCh), and high density lipoprotein (HDL) levels in blood were measured. Swimming significantly improved OGTT (PHOMA-IR (P<0.01). Swim training also significantly decreased FBS (p<0.01), fasting/basal insulin (P<0.01), HbA1C (p<0.01), TG (P<0.05), and TCh (P<0.05) levels. It also significantly increased HDL (p<0.05) level. Our findings indicate that swim training improved glycemic control and insulin sensitivity in type 2 diabetes caused by high fat diet in male rats.

  5. Chronic high-dose creatine has opposing effects on depression-related gene expression and behavior in intact and sex hormone-treated gonadectomized male and female rats.

    Science.gov (United States)

    Allen, Patricia J; DeBold, Joseph F; Rios, Maribel; Kanarek, Robin B

    2015-03-01

    Creatine is an antioxidant, neuromodulator and key regulator of energy metabolism shown to improve depressive symptoms in humans and animals, especially in females. To better understand the pharmacological effects of creatine, we examined its influence on depression-related hippocampal gene expression and behaviors in the presence and absence of sex steroids. Sham-operated and gonadectomized male and female rats were fed chow alone or chow blended with either 2% or 4% w/w creatine monohydrate for five weeks before forced swim, open field, and wire suspension tests, or seven weeks total. Before supplementation, males were chronically implanted with an empty or a testosterone-filled (T) capsule (10-mm surface release), and females were administered progesterone (P, 250 μg), estradiol benzoate (EB, 2.5 μg), EB+P, or sesame oil vehicle weekly. Relative to non-supplemented shams, all hippocampal plasticity-related mRNAs measured, including brain-derived neurotrophic factor (BDNF), tyrosine kinase B, doublecortin, calretinin, and calbindin, were downregulated in sham males given 4% creatine, and BDNF, doublecortin, and calbindin mRNAs were downregulated in sham females given 4% creatine. In contrast, combined 4% creatine+T in castrates prevented downregulation of BDNF, doublecortin, and calretinin mRNAs. Similarly, combined 4% creatine+EB+P in ovariectomized females attenuated downregulation of BDNF and calbindin mRNA levels. Moderate antidepressant and anxiolytic-like behaviors were observed in EB+P-treated ovariectomized females fed creatine, with similar trends in T-treated castrates fed creatine. Altogether, these data show that chronic, high-dose creatine has opposing effects on neuroplasticity-related genes and depressive behavior in intact and gonadectomized male and female rats. The dose and schedule of creatine used negatively impacted hippocampal neuronal integrity in otherwise healthy brains, possibly through negative compensatory changes in energy

  6. Effects of dose, species, and dosing vehicle on the disposition of methacrylonitrile (MAN) in male rats

    International Nuclear Information System (INIS)

    Sanchez, I.M.; Ghanayem, B.I.

    1991-01-01

    MAN is structurally similar to known carcinogen acrylontrile (AN), with nitriles having similar industrial uses. Current studies were designed to investigate the biological fate of 2- 14 C-MAN in rats. After gavage administration of 115, 11.5 or 1.15 mg MAN/kg in water, F344 male rats were placed in glass metabolism cages and urine, expired air and feces were collected. Rats were sacrificed at various times and concentration of MAN-derived radioactivity in tissues was determined. MAN was rapidly absorbed from the GI tract and distributed to all major tissues. Sixty-70% of the low and medium doses were exhaled as 14 CO 2 in 72 hr compared to 25% of the highest dose. While 40% of the highest dose was expired as organic volatiles in 72 hr, only 9-12% of the low and accounted for 20-30% of all doses within 72 hr after dosing. Comparison of MAN disposition in Sprague-Dawley (SD) and F344 rats at 115 mg/kg revealed that SD rats excreted a greater % of the dose as 14 CO 2 and in the urine than did F344 rats. Administration of 115 mg MAN/kg to SD male rats in safflower oil resulted in increased elimination of MAN-derived radioactivity as CO 2 , volatiles, and in the urine over that observed when administered in water. These results suggest that: (1) saturation of MAN metabolism occurs at high doses: (2) MAN metabolism and disposition differ with the strain of rats studied; (3) MAN disposition may vary with the dosing vehicle used; and (4) MAN metabolism and disposition is apparently different from that reported on AN

  7. Assessment of the Toxicity of Sub-chronic Low and High Doses of the Bio-insecticide Spinosad on the Liver, Kidney and the Cerebellum in Male Albino Mice

    Directory of Open Access Journals (Sweden)

    Sabry A El-Naggar

    2017-06-01

    Full Text Available ABSTRACT Spinosad (SPD is a highly selective insect control product. However, it was reported that SPD has toxicity toward other non-target organisms. This study was conducted to address the toxic effect of two sub-chronic low and high doses; 35 and 350 mg/kg SPD on some biochemical, histological and immunohistochemical parameters of the liver, kidney and cerebellum. Thirty-six male Swiss mice were divided into three groups of 12 mice each; first group (G1 served as a control, second group (G2 received a low sub-chronic dose of SPD that is equal to 35 mg/kg, and third group (G3 received a high sub-chronic dose of SPD that is equal to 350 mg/kg. The results showed that mice which were received 350 mg/kg SPD showed a significant decrease in the body weight and a significant increase in their relative kidney and spleen weights. They also showed a significant increase in alanine aminotransferase (ALT, triglycerides and urea levels. Histopathological examination showed cytoplasmic degeneration and cell necrosis in the liver and kidney. Immunohistochemical examination showed that cerebellum illustrated several neurodegenerative changes and a down-regulation of synaptophysin-Syp. In conclusion, exposure to a high dose of SPD that is equal to 350 mg/kg could cause a marked toxicity on the liver, kidney and cerebellum in male albino mice.

  8. Gamma dosimetry of high doses

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  9. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in male, pregnant and non-pregnant female rabbits after single high dose inhalation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Tobias [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany); Bertermann, Rüdiger [Institut für Anorganische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg (Germany); Rusch, George M. [Honeywell, P.O. Box 1057, Morristown, NJ 07962–1057 (United States); Hoffman, Gary M. [Huntingdon Life Sciences., East Millstone, NJ (United States); Dekant, Wolfgang, E-mail: dekant@toxi.uni-wuerzburg.de [Institut für Toxikologie, Universität Würzburg, Versbacher Str. 9, 97078 Würzburg (Germany)

    2012-08-15

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a novel refrigerant intended for use in mobile air conditioning. It showed a low potential for toxicity in rodents studies with most NOAELs well above 10,000 ppm in guideline compliant toxicity studies. However, a developmental toxicity study in rabbits showed mortality at exposure levels of 5,500 ppm and above. No lethality was observed at exposure levels of 2,500 and 4,000 ppm. Nevertheless, increased subacute inflammatory heart lesions were observed in rabbits at all exposure levels. Since the lethality in pregnant animals may be due to altered biotransformation of HFO-1234yf and to evaluate the potential risk to pregnant women facing a car crash, this study compared the acute toxicity and biotransformation of HFO-1234yf in male, female and pregnant female rabbits. Animals were exposed to 50,000 ppm and 100,000 ppm for 1 h. For metabolite identification by {sup 19}F NMR and LC/MS-MS, urine was collected for 48 h after inhalation exposure. In all samples, the predominant metabolites were S-(3,3,3-trifluoro-2-hydroxypropanyl)-mercaptolactic acid and N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine. Since no major differences in urinary metabolite pattern were observed between the groups, only N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine excretion was quantified. No significant differences in recovery between non-pregnant (43.10 ± 22.35 μmol) and pregnant female (50.47 ± 19.72 μmol) rabbits were observed, male rabbits exposed to 100,000 ppm for one hour excreted 86.40 ± 38.87 μmol. Lethality and clinical signs of toxicity were not observed in any group. The results suggest that the lethality of HFO-1234yf in pregnant rabbits unlikely is due to changes in biotransformation patterns or capacity in pregnant rabbits. -- Highlights: ► No lethality and clinical signs were observed. ► No differences in metabolic pattern between pregnant and non-pregnant rabbits. ► Rapid and similar metabolite

  10. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in male, pregnant and non-pregnant female rabbits after single high dose inhalation exposure

    International Nuclear Information System (INIS)

    Schmidt, Tobias; Bertermann, Rüdiger; Rusch, George M.; Hoffman, Gary M.; Dekant, Wolfgang

    2012-01-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a novel refrigerant intended for use in mobile air conditioning. It showed a low potential for toxicity in rodents studies with most NOAELs well above 10,000 ppm in guideline compliant toxicity studies. However, a developmental toxicity study in rabbits showed mortality at exposure levels of 5,500 ppm and above. No lethality was observed at exposure levels of 2,500 and 4,000 ppm. Nevertheless, increased subacute inflammatory heart lesions were observed in rabbits at all exposure levels. Since the lethality in pregnant animals may be due to altered biotransformation of HFO-1234yf and to evaluate the potential risk to pregnant women facing a car crash, this study compared the acute toxicity and biotransformation of HFO-1234yf in male, female and pregnant female rabbits. Animals were exposed to 50,000 ppm and 100,000 ppm for 1 h. For metabolite identification by 19 F NMR and LC/MS-MS, urine was collected for 48 h after inhalation exposure. In all samples, the predominant metabolites were S-(3,3,3-trifluoro-2-hydroxypropanyl)-mercaptolactic acid and N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine. Since no major differences in urinary metabolite pattern were observed between the groups, only N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine excretion was quantified. No significant differences in recovery between non-pregnant (43.10 ± 22.35 μmol) and pregnant female (50.47 ± 19.72 μmol) rabbits were observed, male rabbits exposed to 100,000 ppm for one hour excreted 86.40 ± 38.87 μmol. Lethality and clinical signs of toxicity were not observed in any group. The results suggest that the lethality of HFO-1234yf in pregnant rabbits unlikely is due to changes in biotransformation patterns or capacity in pregnant rabbits. -- Highlights: ► No lethality and clinical signs were observed. ► No differences in metabolic pattern between pregnant and non-pregnant rabbits. ► Rapid and similar metabolite

  11. Radon progeny dose conversion coefficients for Chinese males and females

    Energy Technology Data Exchange (ETDEWEB)

    Yu, K.N. E-mail: peter.yu@city.edu.hk; Cheung, T.T.K.; Haque, A.K.M.M.; Nikezic, D.; Lau, B.M.F.; Vucic, D

    2001-07-01

    The airway dimensions for Caucasian males have been scaled by multiplying by factors 0.95 and 0.88 to give those for Chinese males and females, respectively. Employing the most recent data on physical and biological parameters, the radiation doses to the basal and secretory cells due to {alpha} particles from {sup 218}Po and {sup 214}Po, homogeneously distributed in the mucous layer, have been calculated. The emission of {alpha} particles has been simulated by a Monte Carlo method. For both basal and secretory cells, the dose conversion coefficients (DCCs) for physical conditions of sleep, rest, light and heavy exercise, have been obtained for Chinese males and females for unattached progeny, and for attached progeny of diameters 0.02, 0.15, 0.25, 0.30 and 0.50 {mu}m. For basal cells, the coefficients lie in the range 0.69-6.82 mGy/(J s/m{sup 3}) or 8.7-86 mGy/WLM for unattached progeny and in the range 0.045-1.98 mGy/(J s/m{sup 3}) or 0.57-25 mGy/WLM for attached progeny. The corresponding ranges for Caucasian males are 1.27-8.81 mGy/(J s/m{sup 3}) or 16-111 mGy/WLM{sup -1} and 0.05-2.30 mGy/(J s/m{sup 3}) or 0.64-29 mGy/WLM. For secretory cells, the coefficients lie in the range 0.095-16.82 mGy/(J s/m{sup 3}) (1.2-212 mGy/WLM) for unattached progeny and in the range 0.095-6.67 mGy/(J s/m{sup 3}) (1.2-84 mGy/WLM) for attached progeny. The corresponding ranges for Caucasian males are 0.34-21.51 mGy/(J s/m{sup 3}) (4.3-271 mGy/WLM) and 0.1-7.78 mGy/(J s/m{sup 3}) (1.3-98 mGy/WLM). The overall DCCs calculated for a typical home environment are 0.59 and 0.52 mSv/(J s/m{sup 3}) (7.4 and 6.5 mSv/WLM) for Chinese males and females, respectively, which are 80 and 70% of the value, 0.73 mSv/(J s/m{sup 3}) (9.2 mSv/WLM), for Caucasian males.

  12. Beneficial effects of low dose Musa paradisiaca on the semen quality of male Wistar rats.

    Science.gov (United States)

    Alabi, A S; Omotoso, Gabriel O; Enaibe, B U; Akinola, O B; Tagoe, C N B

    2013-03-01

    This study aimed at determining the effects of administration of mature green fruits of Musa paradisiaca on the semen quality of adult male Wistar rats. THE ANIMALS USED FOR THE STUDY WERE GROUPED INTO THREE: the control group, given 2 ml of double distilled water, a low dose group given 500 mg/kg/day and a high dose group given 1000 mg/kg/day of the plantain fruits, which was made into flour, and dissolved in 2 ml of double distilled water for easy oral administration. Significant increment in the semen parameters was noticed in animals that received a lower dose of the plantain flour, but those animals who received the high dose had marked and very significant reduction in sperm cell concentration and percentage of morphologically normal spermatozoa. Musa paradisiaca should be consumed in moderate quantities in order to derive its beneficial effects of enhancing male reproductive functions.

  13. Assessment of eye, hand and male gonadal skin dose in radiotherapy

    International Nuclear Information System (INIS)

    Pushap, M.P.S.

    1979-01-01

    An attempt has been made to gauge the dose to (1) the eye, (2) the skin of the hands and (3) the gonads from radiotherapy of other parts of the body. The study has been done on actual male patients at the Jorjani Medical Centre, Tehran. The study, indicated high dose to the eye lid i.e. about 3% of the tumour dose in the case of head irradiation. The eyes and gonads lie at unequal distances from thorax, so are their doses. It is further emphasised that a minimum dose of 400 rad in three weeks to one month has been reported to be cataractogenic in man. A 50% incidence of progressive loss of vision with a dose of 750 rad to 1000 rad in three weeks to three months time has been observed. If appropriate techniques are not employed to shield the eye, even from stray radiation, such limits may easily be reached. (K.B.)

  14. Effect of Variable Doses of Zinc Oxide Nanoparticles on Male Albino Mice Behavior.

    Science.gov (United States)

    Zahra, Javeria; Iqbal, Shahid; Zahra, Kiran; Javed, Zulha; Shad, Muhammad Aslam; Akbar, Atif; Ashiq, Muhammad Naeem; Iqbal, Furhan

    2017-02-01

    Zinc oxide nanoparticles (ZnO NPs) have diverse utility these days ranging from being part of nanosensors to be ingredient of cosmetics. Present study was designed to report the effect of variable doses of ZnO NPs on selected aspects of male albino mice behavior. Nano particles were synthesized by sol-gel auto-combustion method (Data not shown here). 10 week old male albino mice were divided into four experimental groups; group A, B and C were orally supplemented with 50 (low dose), 300 (medium dose) and 600 mg/ml solvent/kg body weight (high dose) of ZnO NPs for 4 days. Group D (control) orally received 0.2 M sodium phosphate buffer (solvent for ZnO NPs) for the same duration. A series of neurological tests (Rota rod, open field, novel object and light-dark box test) were conducted in all groups and performance was compared between ZnO NPs treated and control group. Muscular functioning during rota rod test was significantly improved in all ZnO NPs treated mice as compared to control group. While no significant differences in open field, novel object and light-dark box test performance were observed when data from studied parameters of specific ZnO NPs treatment were compared with the control group indicating that applied doses of ZnO NPs did not affect the exploratory, anxiolytic behavior and object recognition capability of adult male albino mice.

  15. Optimized dose distribution of a high dose rate vaginal cylinder

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  16. A randomized phase III study comparing standard dose BEP with sequential high-dose cisplatin, etoposide, and ifosfamide (VIP) plus stem-cell support in males with poor-prognosis germ-cell cancer. An intergroup study of EORTC, GTCSG, and Grupo Germinal (EORTC 30974)

    DEFF Research Database (Denmark)

    Daugaard, G; Skoneczna, I; Aass, N

    2011-01-01

    To compare the efficacy of one cycle of standard dose cisplatin, etoposide, and ifosfamide (VIP) plus three cycles of high-dose VIP followed by stem-cell infusion [high-dose chemotherapy (HD-CT arm)] to four cycles of standard cisplatin, etoposide, and bleomycin (BEP) in patients with poor-progno...

  17. Pharmacokinetically guided dosing of (high-dose) chemotherapeutic agents

    NARCIS (Netherlands)

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

    2004-01-01

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

  18. Effects of Gamma Irradiation and Dose Accumulation on the Histology of Spodoptera littoralis (Boisd.) Male Testes

    International Nuclear Information System (INIS)

    Sallam, H.A.; El-Naggar, S.E.M.; Shibel, M.M.; El-Dossouki, S.A.

    2000-01-01

    Full-grown male pupae of the cotton leaf worm Spodoptera littoralis (Boisd.) were gamma irradiated with low doses of 25, 50, 75 or 100 Gy. The effects of accumulating doses applied to these pupae through three consequent filial generations and the retarded influence on their F 1 , F 2 and F 3 generations progeny were examined. The histological observations showed that the damage in the testes was correlated with increasing the dose applied to the male parents and was the highest among the adults of F 1 . Also, the damage at any acute dose was less than the damage occurred in the same accumulated dose. The deteriorations on the testes were more evident in case of F 1 males resulting from parental males irradiated through two or three successive generations or three accumulated doses of 25 or 50 Gy

  19. Fiber optics in high dose radiation fields

    International Nuclear Information System (INIS)

    Partin, J.K.

    1985-01-01

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

  20. Dose profile study in head CT scans using a male anthropomorphic phantom

    International Nuclear Information System (INIS)

    Gomez, Alvaro M.L.; Santana, Priscila do C.; Mourao, Arnaldo P.

    2017-01-01

    Computed tomography (CT) test is an efficient and non-invasive method to obtain data about internal structures of the human body. CT scans contribute with the highest absorbed doses in population due X-ray beam attenuation and it has raised concern in radiosensitive tissues. Techniques for the optimization of CT scanning protocols in diagnostic services have been developing with the objective of decreasing the absorbed dose in the patient, aiming image quality within acceptable parameters for diagnosis by noise control. Routine head scans were performed using GE CT scan of 64 channels programmed with automatic exposure control and voltages of 80, 100 and 120 kV attaching the noise index in approximately 0.5%, using the tool of smart mA. An anthropomorphic adult male phantom was used and radiochromic film strips were placed to measure the absorbed dose deposited in areas such as the lens, thyroid and pituitary for study of dose deposited in these important areas containing high radiosensitive tissues. Different head scans were performed using optimized values of mA.s for the different voltages. The absorbed dose measured by the film strips were in the range of the 0.58 and 44.36 mGy. The analysis of noise in the images is within the acceptable levels for diagnosis, and the optimized protocol happens with the voltage of 100 kV. The use of other voltage values can allow obtain better protocols for head scans. (author)

  1. Dose profile study in head CT scans using a male anthropomorphic phantom

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Alvaro M.L.; Santana, Priscila do C.; Mourao, Arnaldo P., E-mail: amlgphys@gmail.com, E-mail: pridili@gmail.com, E-mail: apratabhz@gmail.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear; Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    Computed tomography (CT) test is an efficient and non-invasive method to obtain data about internal structures of the human body. CT scans contribute with the highest absorbed doses in population due X-ray beam attenuation and it has raised concern in radiosensitive tissues. Techniques for the optimization of CT scanning protocols in diagnostic services have been developing with the objective of decreasing the absorbed dose in the patient, aiming image quality within acceptable parameters for diagnosis by noise control. Routine head scans were performed using GE CT scan of 64 channels programmed with automatic exposure control and voltages of 80, 100 and 120 kV attaching the noise index in approximately 0.5%, using the tool of smart mA. An anthropomorphic adult male phantom was used and radiochromic film strips were placed to measure the absorbed dose deposited in areas such as the lens, thyroid and pituitary for study of dose deposited in these important areas containing high radiosensitive tissues. Different head scans were performed using optimized values of mA.s for the different voltages. The absorbed dose measured by the film strips were in the range of the 0.58 and 44.36 mGy. The analysis of noise in the images is within the acceptable levels for diagnosis, and the optimized protocol happens with the voltage of 100 kV. The use of other voltage values can allow obtain better protocols for head scans. (author)

  2. Endorectal high dose rate brachytherapy quality assurance

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  3. Progress in high-dose radiation dosimetry

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  4. Sterility and Sexual Competitiveness of Tapachula-7 Anastrepha ludens Males Irradiated at Different Doses.

    Science.gov (United States)

    Orozco-Dávila, Dina; Adriano-Anaya, Maria de Lourdes; Quintero-Fong, Luis; Salvador-Figueroa, Miguel

    2015-01-01

    A genetic sexing strain of Anastrepha ludens (Loew), Tapachula-7, was developed by the Mexican Program Against Fruit Flies to produce and release only males in programs where the sterile insect technique (SIT) is applied. Currently, breeding are found at a massive scale, and it is necessary to determine the optimum irradiation dose that releases sterile males with minimum damage to their sexual competitiveness. Under laboratory and field conditions, we evaluated the effects of gamma irradiation at doses of 0, 20, 40, 60 and 80 Gy on the sexual competitiveness of males, the induction of sterility in wild females and offspring survivorship. The results of the study indicate that irradiation doses have a significant effect on the sexual behavior of males. A reduction of mating capacity was inversely proportional to the irradiation dose of males. It is estimated that a dose of 60 Gy can induce more than 99% sterility in wild females. In all treatments, the degree of offspring fertility was correlated with the irradiation dose of the parents. In conclusion, the results of the study indicate that a dose of 60 Gy can be applied in sterile insect technique release programs. The application of this dose in the new genetic sexing strain of A. ludens is discussed.

  5. High dose rate brachytherapy in treatment of high grade astrocytomas

    International Nuclear Information System (INIS)

    Garcia-Alejo, R.; Delgado, J.M.; Cerro, E. del; Torres, J.J.; Martinez, R.

    1996-01-01

    From May 1994 to June 1995, 18 patients with high grade astrocytomas were entered prospectively on a selective protocol combining surgery, external beam radiotherapy, stereotactic interstitial implantation with HDR Iridium 192 and chemotherapy. Only those patients with tumor size 100cc or less average dimension, high grade astrocytoma, Karnofsky 70 or greater, unilateral, circumscribed, unifocal, tumor stable or responding to external radiation and supratentorial were included in the study. Ages ranged from 16 to 69 years. There were 13 males and 5 females. Surgery consisted of biopsy only in 3 patients, subtotal resection in 11, and gross total resection in 4 patients. Focal external beam radiation portals included the contrast enhancing mass on CT scan plus a 3 cm margin. The protocol called for minimum tumor dose of 60 Gy to be given in 2 Gy daily fractions. An interstitial brachytherapy boost was to be performed two weeks after the conclusion of external beam radiation. The dose was 30 Gy in 4 fractions. The authors analyze on basis on their personal experience, the possibilities and the limits offered by this therapeutic procedure in neuro-oncology. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically possible with negligible acute morbidity and mortality, and appeared to be effective and may provide for an increase in tumor control in selected cases

  6. Low dose DDT inhibition of hepatocarcinogenesis initiated by diethylnitrosamine in male rats: Possible mechanisms

    International Nuclear Information System (INIS)

    Kushida, Masahiko; Sukata, Tokuo; Uwagawa, Satoshi; Ozaki, Keisuke; Kinoshita, Anna; Wanibuchi, Hideki; Morimura, Keiichirou; Okuno, Yasuyoshi; Fukushima, Shoji

    2005-01-01

    Previously we reported a tendency for reduction of the development of glutathione-S-transferase placental form (GST-P) positive foci, recognized as preneoplastic changes in rat liver, by a low dose of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), which belongs to the same group of hepatic cytochrome P-450 inducers as phenobarbital and is itself a non-genotoxic hepatocarcinogen. In order to clarify the biological significance of this phenomenon, we investigated the reproducibility and changes in other parameters using an initiation-promotion model in which male F344 rats were treated with DDT at doses of 0, 0.005, 0.5, 500 ppm in the diet for 11 or 43 weeks after initiation of hepatocarcinogenesis with N-diethylnitrosamine (DEN). When 500 ppm DDT was applied, the formation of GST-P positive foci and tumor were markedly elevated. In contrast, induction of GST-P positive foci and liver tumors tended to be inhibited at a dose of 0.005 ppm, correlating with protein levels of cytochrome P450 2B1 and 3A2 (CYP2B1 and 3A2) and generation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage. mRNA levels for 8-oxoguanine glycosylase 1 (OGG1), an 8-OHdG repair enzyme, connexin 32 (Cx32), a major component of Gap junctions, and hepatic nuclear factor 1α (HNF-1α), a Cx32 regulator, were inversely correlated with GST-P positive foci and tumor formation. These results indicate that low dose DDT may indeed exhibit inhibitory effects on chemically initiated-rat hepatocarcinogenicity, in contrast to the promotion observed with high doses, and that this is related to changes in metabolizing enzymes, cell communication, and DNA damage and its repair

  7. High-dose irradiation of food

    International Nuclear Information System (INIS)

    Diehl, J.F.

    1999-01-01

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

  8. Dose-response for X-ray induction of myeloid leukaemia in male CBA/H mice

    Energy Technology Data Exchange (ETDEWEB)

    Mole, R H; Papworth, D G; Corp, M J [Medical Research Council, Harwell (UK). Radiobiological Research Unit

    1983-02-01

    The form of the dose-response for induction of malignant diseases in vivo by ionizing radiation is not yet established in spite of its scientific interest and its practical importance. Considerably extended observations have confirmed that the dose-response for acute myeloid leukaemia induced in male CBA/H mice by X-ray exposure is highly curvilinear. The dose-response was well fitted by the expression aD/sup 2/esup(-..gamma..D) (D = dose) in agreement with induction at the cellular level in proportion to D/sup 2/ over the whole dose range 0.25-6.0 Gy. The factor esup(-..gamma..D) accounts for the inescapable concomitant inactivating action of the inducing irradiation. The quantitative aspects of induction of myeloid leukaemia by ionizing radiation are unlike the induction of genetic mutation or cell inactivation and suggest that interaction of two adjoining cells is an essential element in radiation leukaemogenesis.

  9. Concomitant chemoradiotherapy with high dose rate brachytherapy ...

    African Journals Online (AJOL)

    Concomitant chemoradiotherapy with high dose rate brachytherapy as a definitive treatment modality for locally advanced cervical cancer. T Refaat, A Elsaid, N Lotfy, K Kiel, W Small Jr, P Nickers, E Lartigau ...

  10. Radiation effects of high and low doses

    International Nuclear Information System (INIS)

    El-Naggar, A.M.

    1998-01-01

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

  11. Mating competitiveness of male Anopheles arabiensis mosquitoes irradiated with a partially or fully sterilizing dose in small and large laboratory cages.

    Science.gov (United States)

    Helinski, M E H; Knols, B G J

    2008-07-01

    Male mating competitiveness is a crucial parameter in many genetic control programs including the sterile insect technique (SIT). We evaluated competitiveness of male Anopheles arabiensis Patton as a function of three experimental variables: (1) small or large cages for mating, (2) the effects of either a partially sterilizing (70 Gy) or fully sterilizing (120 Gy) dose, and (3) pupal or adult irradiation. Irradiated males competed for females with an equal number of unirradiated males. Competitiveness was determined by measuring hatch rates of individually laid egg batches. In small cages, pupal irradiation with the high dose resulted in the lowest competitiveness, whereas adult irradiation with the low dose gave the highest, with the latter males being equal in competitiveness to unirradiated males. In the large cage, reduced competitiveness of males irradiated in the pupal stage was more pronounced compared with the small cage; the males irradiated as adults at both doses performed similarly to unirradiated males. Unexpectedly, males irradiated with the high dose performed better in a large cage than in a small one. A high proportion of intermediate hatch rates was observed for eggs collected in the large cage experiments with males irradiated at the pupal stage. It is concluded that irradiation of adult An. arabiensis with the partially sterilizing dose results in the highest competitiveness for both cage designs. Cage size affected competitiveness for some treatments; therefore, competitiveness determined in laboratory experiments must be confirmed by releases into simulated field conditions. The protocols described are readily transferable to evaluate male competitiveness for other genetic control techniques.

  12. Ionization chamber for high dose measurements

    International Nuclear Information System (INIS)

    Rodrigues Junior, Ary de Araujo

    2005-01-01

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

  13. Intracranial meningiomas after high-dose irradiation

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    International Nuclear Information System (INIS)

    McLaughlin, W.L.

    1985-01-01

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

  15. Dosimetric systems of high dose, dose rate and dose uniformity in food and medical products

    International Nuclear Information System (INIS)

    Vargas, J.; Vivanco, M.; Castro, E.

    2014-08-01

    In the Instituto Peruano de Energia Nuclear (IPEN) we use the chemical dosimetry Astm-E-1026 Fricke as a standard dosimetric system of reference and different routine dosimetric systems of high doses, according to the applied doses to obtain the desired effects in the treated products and the doses range determined for each type of dosimeter. Fricke dosimetry is a chemical dosimeter in aqueous solution indicating the absorbed dose by means an increase in absorbance at a specific wavelength. A calibrated spectrophotometer with controlled temperature is used to measure absorbance. The adsorbed dose range should cover from 20 to 400 Gy, the Fricke solution is extremely sensitive to organic impurities, to traces of metal ions, in preparing chemical products of reactive grade must be used and the water purity is very important. Using the referential standard dosimetric system Fricke, was determined to March 5, 2013, using the referential standard dosimetric system Astm-1026 Fricke, were irradiated in triplicate Fricke dosimeters, to 5 irradiation times (20; 30; 40; 50 and 60 seconds) and by linear regression, the dose rate of 5.400648 kGy /h was determined in the central point of the irradiation chamber (irradiator Gamma cell 220 Excel), applying the decay formula, was compared with the obtained results by manufacturers by means the same dosimetric system in the year of its manufacture, being this to the date 5.44691 kGy /h, with an error rate of 0.85. After considering that the dosimetric solution responds to the results, we proceeded to the irradiation of a sample of 200 g of cereal instant food, 2 dosimeters were placed at the lateral ends of the central position to maximum dose and 2 dosimeters in upper and lower ends as minimum dose, they were applied same irradiation times; for statistical analysis, the maximum dose rate was 6.1006 kGy /h and the minimum dose rate of 5.2185 kGy /h; with a dose uniformity of 1.16. In medical material of micro pulverized bone for

  16. Dose- dependent ameliorative effects of quercetin and l-Carnitine against atrazine- induced reproductive toxicity in adult male Albino rats.

    Science.gov (United States)

    Abdel Aziz, Rabie L; Abdel-Wahab, Ahmed; Abo El-Ela, Fatma I; Hassan, Nour El-Houda Y; El-Nahass, El-Shaymaa; Ibrahim, Marwa A; Khalil, Abdel-Tawab A Y

    2018-06-01

    This study aimed to determine the protective effects of co-administration of Quercetin (QT) or l-Carnitine (LC) against the oxidative stress induced by Atrazine (ATZ) in the reproductive system of intact male Albino rats. 36 rats were divided equally into 6 groups. Rats in the control negative "CNT" group received 1.5 ml distilled water for 21 days. All rats in the other groups received ATZ (120 mg/kg bw) through gavage. Groups 3 and 4 were co-administered with either low or high dose of QT (10 "ATZLQT" and 50 "ATZHQT" mg/kg bw, respectively). Groups 5 and 6 were co-administered with either low or high dose of LC (200 "ATZLLC" and 400 "ATZHLC" mg/kg bw, respectively). At the end of the experiment, animals were sacrificed and all samples were collected. ATZ significantly increased serum level of malondialdehyde (MDA) and decreased total antioxidant capacity (TAC). Also, ATZ increased significantly the sperm cell abnormalities and reduced both testicular IgA and serum testosterone levels. Testicular DNA laddering % and CYP17A1 mRNA expression were significantly reduced in ATZ group. Interestingly, co-administration with low dose QT or different doses of LC succeeded to counteract the negative toxic effects of ATZ on serum oxidative stress indicators, serum testosterone levels, testicular IgA level and improved testicular CYP17A1 mRNA expression. In conclusion, QT in low dose and LC in both low and high doses exerted a significant protective action against the reproductive toxicity of ATZ, while higher dose of QT failed induce immune-stimulant effect against ATZ in adult male Albino rats. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  17. Nonlinear model of high-dose implantation

    International Nuclear Information System (INIS)

    Danilyuk, A.

    2001-01-01

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

  18. High dose gamma-ray standard

    International Nuclear Information System (INIS)

    Macrin, R.; Moraru, R.

    1999-01-01

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

  19. NIST high-dose calibration services

    International Nuclear Information System (INIS)

    Humphreys, J.C.

    1989-01-01

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

  20. High-dose erythropoietin for tissue protection

    DEFF Research Database (Denmark)

    Lund, Anton; Lundby, Carsten; Olsen, Niels Vidiendal

    2014-01-01

    BACKGROUND: The discovery of potential anti-apoptotic and cytoprotective effects of recombinant human erythropoietin (rHuEPO) has led to clinical trials investigating the use of high-dose, short-term rHuEPO therapy for tissue protection in conditions such as stroke and myocardial infarction....... Experimental studies have been favourable, but the clinical efficacy has yet to be validated. MATERIALS AND METHODS: We have reviewed clinical studies regarding the use of high-dose, short-term rHuEPO therapy for tissue protection in humans with the purpose to detail the safety and efficacy of r...... no effect of rHuEPO therapy on measures of tissue protection. Five trials including 1025 patients reported safety concerns in the form of increased mortality or adverse event rates. No studies reported reduced mortality. CONCLUSIONS: Evidence is sparse to support a tissue-protective benefit of r...

  1. Effect of γ-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

    International Nuclear Information System (INIS)

    Jha, Pradeep K.; Jha, Rakhi; Gupta, B.L.; Guha, Sujoy K.

    2010-01-01

    Functional necessity to use a particular range of dose rate and total dose of γ-initiated polymerization to manufacture a novel polymeric hydrogel RISUG (reversible inhibition of sperm under guidance) made of styrene maleic anhydride (SMA) dissolved in dimethyl sulphoxide (DMSO), for its broad biomedical application explores new dimension of research. The present work involves 16 irradiated samples. They were tested by fourier transform infrared spectroscopy, matrix assisted laser desorption/ionization-TOF, field emission scanning electron microscopy, high resolution transmission electron microscopy, etc. to see the interrelation effect of gamma dose rates (8.25, 17.29, 20.01 and 25.00 Gy/min) and four sets of doses (1.8, 2.0, 2.2 and 2.4 kGy) on the molecular weight, molecular weight distribution and porosity analysis of the biopolymeric drug RISUG. The results of randomized experiment indicated that a range of 18-24 Gy/min γ-dose rate and 2.0-2.4 kGy γ-total doses is suitable for the desirable in vivo performance of the contraceptive copolymer.

  2. High dose rate brachytherapy for oral cancer

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Koizumi, Masahiko; Ogawa, Kazuhiko; Furukawa, Souhei

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

  3. High dose rate brachytherapy for oral cancer.

    Science.gov (United States)

    Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Furukawa, Souhei; Koizumi, Masahiko; Ogawa, Kazuhiko

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer.

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

    Science.gov (United States)

    Sorrentino, Annalise

    2005-04-01

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

  5. Applicability of dose conversion coefficients of ICRP 74 to Asian adult males: Monte Carlo simulation study

    International Nuclear Information System (INIS)

    Lee, Choonsik; Lee, Choonik; Lee, Jai-Ki

    2007-01-01

    International Commission on Radiological Protection (ICRP) reported comprehensive dose conversion coefficients for adult population, which is exposed to external photon sources in the Publication 74. However, those quantities were calculated from so-called stylized (or mathematical) phantoms composed of simplified mathematical surface equations so that the discrepancy between the phantoms and real human anatomy has been investigated by several authors using Caucasian-based voxel phantoms. To address anatomical and racial limitations of the stylized phantoms, several Asian-based voxel phantoms have been developed by Korean and Japanese investigators, independently. In the current study, photon dose conversion coefficients of ICRP 74 were compared with those from a total of five Asian-based male voxel phantoms, whose body dimensions were almost identical. Those of representative radio-sensitive organs (testes, red bone marrow, colon, lungs, and stomach), and effective dose conversion coefficients were obtained for comparison. Even though organ doses for testes, colon and lungs, and effective doses from ICRP 74 agreed well with those from Asian voxel phantoms within 10%, absorbed doses for red bone marrow and stomach showed significant discrepancies up to 30% which was mainly attributed to difference of phantom description between stylized and voxel phantoms. This study showed that the ICRP 74 dosimetry data, which have been reported to be unrealistic compared to those from Caucasian-based voxel phantoms, are also not appropriate for Asian population

  6. Low-dose effects of bisphenol A on early sexual development in male and female rats

    DEFF Research Database (Denmark)

    Christiansen, Sofie; Petersen, Marta Axelstad; Boberg, Julie

    2014-01-01

    the influence of BPA on early sexual development in male and female rats at dose levels covering both regulatory no observed adverse effect levels (NOAELs) (5 and 50 mg/kg bw per day) as well as doses in the microgram per kilogram dose range (0.025 and 0.25 mg/kg bw per day). Time-mated Wistar rats (n=22) were...... in both sexes indicates effects on prenatal sexual development and provides new evidence of low-dose adverse effects of BPA in rats in the microgram per kilogram dose range. The NOAEL in this study is clearly below 5 mg/kg for BPA, which is used as the basis for establishment of the current tolerable......Bisphenol A (BPA) is widely detected in human urine and blood. BPA has been reported to impair many endpoints for reproductive and neurological development; however, it is controversial whether BPA has effects in the microgram per kilogram dose range. The aim of the current study was to examine...

  7. Radiation dose reduction to the male gonads during MDCT: the effectiveness of a lead shield.

    Science.gov (United States)

    Hohl, Christian; Mahnken, Andreas H; Klotz, Ernst; Das, Marco; Stargardt, Achim; Mühlenbruch, Georg; Schmidt, Thorsten; Günther, Rolf W; Wildberger, Joachim E

    2005-01-01

    Our study was designed to quantify the effect of a standard gonad shield on the testicular radiation exposure due to scatter during routine abdominopelvic MDCT. Routine abdominopelvic MDCT was performed in 34 patients with gonadal lead shielding and 32 patients without this shielding; the testes were not exposed to the direct beam during the examination. We estimated the testicular dose administered with thermoluminescent dosimetry, taking into account each patient's body weight and body mass index (BMI). With a 1-mm lead shield, the mean testicular dose was reduced from 2.40 to 0.32 mSv, a reduction of 87%. The difference was found to be statistically significant (p Shielding the male gonads reduces the testicular radiation dose during abdominopelvic MDCT significantly and can be recommended for routine use.

  8. High dose rate endobronchial brachytherapy - treatment technique

    International Nuclear Information System (INIS)

    Carvalho, Heloisa de Andrade; Aisen, Salim; Haddad, Cecilia Maria Kalil; Nadalin, Wladimir; Pedreira Junior, Wilson Leite; Chavantes, Maria Cristina

    1998-01-01

    High dose rate endobronchial brachytherapy is efficient in symptom relief due to obstructive endobronchial malignancies. However, it's role in survival improvement for patients with lung cancer is not yet established. The use of this treatment in increasing, specially in the developing countries. The purpose of this paper is to present the treatment technique used in the Radiotherapy Department of the Hospital da Clinicas, University of Sao Paulo, based on an experience of 60 cases treated with 180 procedures. Some practical suggestions and rules adopted in the Department are described. The severe complications rate is 6.7%, demonstrating an adequate patient selection associated with the technique utilized. (author)

  9. Neuroprotective potential of high-dose biotin.

    Science.gov (United States)

    McCarty, Mark F; DiNicolantonio, James J

    2017-11-01

    A recent controlled trial has established that high-dose biotin supplementation - 100 mg, three times daily - has a stabilizing effect on progression of multiple sclerosis (MS). Although this effect has been attributed to an optimization of biotin's essential cofactor role in the brain, a case can be made that direct stimulation of soluble guanylate cyclase (sGC) by pharmacological concentrations of biotin plays a key role in this regard. The utility of high-dose biotin in MS might reflect an anti-inflammatory effect of cGMP on the cerebral microvasculature, as well on oligodendrocyte differentiation and on Schwann cell production of neurotrophic factors thought to have potential for managing MS. But biotin's ability to boost cGMP synthesis in the brain may have broader neuroprotective potential. In many types of neurons and neural cells, cGMP exerts neurotrophic-mimetic effects - entailing activation of the PI3K-Akt and Ras-ERK pathways - that promote neuron survival and plasticity. Hippocampal long term potentiation requires nitric oxide synthesis, which in turn promotes an activating phosphorylation of CREB via a pathway involving cGMP and protein kinase G (PKG). In Alzheimer's disease (AD), amyloid beta suppresses this mechanism by inhibiting sGC activity; agents which exert a countervailing effect by boosting cGMP levels tend to restore effective long-term potentiation in rodent models of AD. Moreover, NO/cGMP suppresses amyloid beta production within the brain by inhibiting expression of amyloid precursor protein and BACE1. In conjunction with cGMP's ability to oppose neuron apoptosis, these effects suggest that high-dose biotin might have potential for the prevention and management of AD. cGMP also promotes neurogenesis, and may lessen stroke risk by impeding atherogenesis and hypertrophic remodeling in the cerebral vasculature. The neuroprotective potential of high-dose biotin likely could be boosted by concurrent administration of brain

  10. Effects of testosterone dose on spatial memory among castrated adult male rats.

    Science.gov (United States)

    Wagner, Benjamin A; Braddick, Valerie C; Batson, Christopher G; Cullen, Brendan H; Miller, L Erin; Spritzer, Mark D

    2018-03-01

    Previous research on the activational effects of testosterone on spatial memory has produced mixed results, possibly because such effects are dose-dependent. We tested a wide range of testosterone doses using two spatial memory tasks: a working-reference memory version of the radial-arm maze (RAM) and an object location memory task (OLMT). Adult male Sprague-Dawley rats were castrated or sham-castrated and given daily injections of drug vehicle (Oil Sham and Oil GDX) or one of four doses of testosterone propionate (0.125, 0.250, 0.500, and 1.000 mg T) beginning seven days before the first day of behavioral tests and continuing throughout testing. For the RAM, four arms of the maze were consistently baited on each day of testing. Testosterone had a significant effect on working memory on the RAM, with the Oil Sham, 0.125 mg T, and 0.500 mg T groups performing better than the Oil GDX group. In contrast, there was no significant effect of testosterone on spatial reference memory on the RAM. For the OLMT, we tested long-term memory using a 2 h inter-trial interval between first exposure to two identical objects and re-exposure after one object had been moved. Only the 0.125 and 0.500 mg T groups showed a significant increase in exploration of the moved object during the testing trials, indicating better memory than all other groups. Testosterone replacement restored spatial memory among castrated male rats on both behavioral tasks, but there was a complex dose-response relationship; therefore, the therapeutic value of testosterone is likely sensitive to dose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Highly competitive reindeer males control female behavior during the rut.

    Directory of Open Access Journals (Sweden)

    Guillaume Body

    Full Text Available During the rut, female ungulates move among harems or territories, either to sample mates or to avoid harassment. Females may be herded by a male, may stay with a preferred male, or aggregate near a dominant male to avoid harassment from other males. In fission-fusion group dynamics, female movement is best described by the group's fission probability, instead of inter-harem movement. In this study, we tested whether male herding ability, female mate choice or harassment avoidance influence fission probability. We recorded group dynamics in a herd of reindeer Rangifer tarandus equipped with GPS collars with activity sensors. We found no evidence that the harassment level in the group affected fission probability, or that females sought high rank (i.e. highly competitive and hence successful males. However, the behavior of high ranked males decreased fission probability. Male herding activity was synchronous with the decrease of fission probability observed during the rut. We concluded that male herding behavior stabilized groups, thereby increasing average group size and consequently the opportunity for sexual selection.

  12. On the genetic risk after high dose radioiodine therapy with regard to the gonadal dose

    International Nuclear Information System (INIS)

    Ehrenheim, C.; Hauswirth, C.; Fitschen, J.; Martin, E.; Oetting, G.; Hundeshagen, H.

    1997-01-01

    Aim: The genetic risk for the offspring of patients treated with high doses of radioiodine was to be assessed with special regard to the gonadal dose caused by diagnostic and therapeutic procedures. Methods: 41 young females (aged between 19 and 39 years) and four young males (aged 26 to 36 years) treated with radioiodine because of a thyroid carcinoma were interviewed by use of a questionnaire. The course of pregnancy and birth history could be documented as well as the congenital and developmental conditions of 56 children. Results: The amount of radioactivity applied for therapy and whole body scans ranged over 4,144 and 35,15 GBq I-131; the individual gonadal dose was calculated based on the MIRD model and ranged over 0,2 and 2,2 Sv (0,51 Sv at a mean). The period of time between the last radioiodine application and confinement was at least 9 months, not exceeding 14 years. As to the course of pregnancy and birth two early abortions, one extrauterine gravidity and one premature birth due to an insufficiency of the placenta were stated. In one case a chromosomal translocation 7/14 occured as a genetic defect which lead to an interruption. The children's development was unconspicuous except of two cases of neurodermatitis as well as multiple allergies and an early closure of the anterior fontanelle in one child each. Conclusion: Although the genetic risk is supposed to increase with the gonadal dose achieved (doubling dose 1 Sv) and the increased risk of any congenital anomaly was calculated as about 13% at a mean in our patients, the rate of genetic determined diseases was not elevated (1,8% or 1/57). Thus, no increase of genetic defects or congenital malformations was reported in a total of 408 children described in the literature and in our group. (orig.) [de

  13. Performance of thermoluminescent materials for high dose dosimetry

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  14. Immune reactivity after high-dose irradiation

    International Nuclear Information System (INIS)

    Gassmann, W.; Wottge, H.U.; von Kolzynski, M.; Mueller-Ruchholtz, W.

    1986-01-01

    Immune reactivity after total-body irradiation was investigated in rats using skin graft rejection as the indicator system. After sublethal irradiation with 10.5 Gy (approximately 50% lethality/6 weeks) the rejection of major histocompatibility complex allogeneic skin grafts was delayed significantly compared with nonirradiated control animals (28 versus 6.5 days). In contrast, skin grafts were rejected after 7.5 days in sublethally irradiated animals and 7 days in lethally irradiated animals if additional skin donor type alloantigens--namely, irradiated bone marrow cells--were given i.v. either simultaneously or with a delay of not more than 24 hr after the above conditioning regimen. These reactions were alloantigen-specific. They were observed in six different strain combinations with varying donors and recipients. Starting on day 2 after irradiation, i.v. injection of bone marrow gradually lost its effectivity and skin grafts were no longer rejected with uniform rapidity; skin donor marrow given on days 4 or 8 did not accelerate skin graft rejection at all. These data show that for approximately 1-2 days after high-dose total-body irradiation rats are still capable of starting a vigorous immune reaction against i.v.-injected alloantigens. The phenomenon of impaired rejection of skin grafted immediately after high-dose irradiation appears to result from the poor accessibility of skin graft alloantigens during the early postirradiation phase when vascularization of the grafted skin is insufficient

  15. High-dose vitamin C and cancer

    Directory of Open Access Journals (Sweden)

    Ahmet Unlu, M.D.

    2016-01-01

    Full Text Available Vitamin C (ascorbic acid, ascorbate is a basic compound that is of great importance with its role in various enzymatic reactions including the synthesis of collagen, as well as with its redox functions. Vitamin C has become the center of interest in cancer studies, in consequence of the facts that connective tissue changes and vitamin C deficiency were first alleged to be associated with cancer in the 1950s; and that high doses of vitamin C was asserted to be cytotoxic for cancer cells, later on. The results of the first study carried out in the 1970s were promising; but afterwards, the studies were ascertained to be faulty. Despite the positive results achieved from some laboratory and animal experiments, randomized clinical trials did not verify those findings, and no clear benefit of vitamin C for cancer treatment could be demonstrated. As for studies, where its use in combination with other cancer treatment regimens was assessed, conflicting results were obtained. Although intake of high doses of vitamin C is alleged to be harmless, based on that it is in the group of water soluble vitamins and is not stored in the body, there are many side effects and drug interactions reported in the literature. For now, it is better to abstain from this treatment, until the benefit of the treatment (if any is clearly demonstrated, considering the potential side effects and interactions.

  16. Dose-response analysis of testosterone replacement therapy in patients with female to male gender identity disorder.

    Science.gov (United States)

    Nakamura, Aya; Watanabe, Masami; Sugimoto, Morito; Sako, Tomoko; Mahmood, Sabina; Kaku, Haruki; Nasu, Yasutomo; Ishii, Kazushi; Nagai, Atsushi; Kumon, Hiromi

    2013-01-01

    Gender identity disorder (GID) is a conflict between a person's actual physical gender and the one they identify him or herself with. Testosterone is the key agent in the medical treatment of female to male GID patients. We conducted a dose-response analysis of testosterone replacement therapy (TRT) in 138 patients to determine the onset of the therapeutic effects. The TRT consisted of intramuscular injection of testosterone enanthate and patients were divided into three groups; 250 mg every two weeks, 250 mg every three weeks and 125 mg every two weeks. The onset of deepening of voice, increase in facial hair and cessation of menses was evaluated in each group. At one month after the start of TRT, the onset of these physical changes was more prevalent in the group receiving the higher dose of testosterone, and there were dose-dependent effects observed between the three treatment groups. On the other hand, at six months after the start of TRT, most of the patients had achieved treatment responses and there were no dose-dependent effects with regard to the percentage of patients with therapeutic effects. No significant side effects were observed in any of the treatment groups. We demonstrated that the early onset of the treatment effects of TRT is dose-dependent, but within six months of starting TRT, all three doses were highly effective. Current study provides useful information to determine the initial dose of TRT and to suggest possible changes that should be made in the continuous dosage for long term TRT.

  17. The effects of simulating a realistic eye model on the eye dose of an adult male undergoing head computed tomography.

    Science.gov (United States)

    Akhlaghi, Parisa; Ebrahimi-Khankook, Atiyeh; Vejdani-Noghreiyan, Alireza

    2017-05-01

    In head computed tomography, radiation upon the eye lens (as an organ with high radiosensitivity) may cause lenticular opacity and cataracts. Therefore, quantitative dose assessment due to exposure of the eye lens and surrounding tissue is a matter of concern. For this purpose, an accurate eye model with realistic geometry and shape, in which different eye substructures are considered, is needed. To calculate the absorbed radiation dose of visual organs during head computed tomography scans, in this study, an existing sophisticated eye model was inserted at the related location in the head of the reference adult male phantom recommended by the International Commission on Radiological Protection (ICRP). Then absorbed doses and distributions of energy deposition in different parts of this eye model were calculated and compared with those based on a previous simple eye model. All calculations were done using the Monte Carlo code MCNP4C for tube voltages of 80, 100, 120 and 140 kVp. In spite of the similarity of total dose to the eye lens for both eye models, the dose delivered to the sensitive zone, which plays an important role in the induction of cataracts, was on average 3% higher for the sophisticated model as compared to the simple model. By increasing the tube voltage, differences between the total dose to the eye lens between the two phantoms decrease to 1%. Due to this level of agreement, use of the sophisticated eye model for patient dosimetry is not necessary. However, it still helps for an estimation of doses received by different eye substructures separately.

  18. The Academic Experience of Male High School Students with ADHD

    Science.gov (United States)

    Kent, Kristine M.; Pelham, William E.; Molina, Brooke S. G.; Sibley, Margaret H.; Waschbusch, Daniel A.; Yu, Jihnhee; Gnagy, Elizabeth M.; Biswas, Aparajita; Babinski, Dara E.; Karch, Kathryn M.

    2011-01-01

    This study compared the high school academic experience of adolescents with and without childhood ADHD using data from the Pittsburgh ADHD Longitudinal Study (PALS). Participants were 326 males with childhood ADHD and 213 demographically similar males without ADHD who were recruited at the start of the follow-up study. Data were collected yearly…

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  20. Dose-dependent adverse effects of salinomycin on male reproductive organs and fertility in mice.

    Directory of Open Access Journals (Sweden)

    Olajumoke Omolara Ojo

    Full Text Available Salinomycin is used as an antibiotic in animal husbandry. Its implication in cancer therapy has recently been proposed. Present study evaluated the toxic effects of Salinomycin on male reproductive system of mice. Doses of 1, 3 or 5 mg/kg of Salinomycin were administered daily for 28 days. Half of the mice were sacrificed after 24 h of the last treatment and other half were sacrificed 28 days after withdrawal of treatment. Effects of SAL on body and reproductive organ weights were studied. Histoarchitecture of testis and epididymis was evaluated along with ultrastructural changes in Leydig cells. Serum and testicular testosterone and luteinizing hormones were estimated. Superoxide dismutase, reduced glutathione, lipid peroxidation, catalase and lactate dehydrogenase activities were measured. Spermatozoa count, morphology, motility and fertility were evaluated. Expression patterns of steroidogenic acute regulatory protein (StAR and cytochrome P450 side chain cleavage proteins (CYP11A1 were assessed by Western blotting. Salinomycin treatment was lethal to few mice and retarded body growth in others with decreased weight of testes and seminal vesicles in a dose dependent manner. Seminiferous tubules in testes were disrupted and the epithelium of epididymis showed frequent occurrence of vacuolization and necrosis. Leydig cells showed hypertrophied cytoplasm with shrunken nuclei, condensed mitochondria, proliferated endoplasmic reticulum and increased number of lipid droplets. Salinomycin decreased motility and spermatozoa count with increased number of abnormal spermatozoa leading to infertility. The testosterone and luteinizing hormone levels were decreased in testis but increased in serum at higher doses. Depletion of superoxide dismutase and reduced glutathione with increased lipid peroxidation in both testis and epididymis indicated generation of oxidative stress. Suppressed expression of StAR and CYP11A1 proteins indicates inhibition of

  1. Cotton Leaf worm: Inherited Effects of Low Doses of Gamma Radiation on The Progeny of Irradiated Males. Vol. 4

    Energy Technology Data Exchange (ETDEWEB)

    Sallam, H A; El-Naggar, S M; Shible, M M [Plant Protection Department, Faculty of Agriculture, Al-Azhar University, Cairo, (Egypt); El-Dessouki, S A; El-Awady, S M [Biological Applications Department, Nuclear Research Center, Atomic Energy Authority, Cairo, (Egypt)

    1996-03-01

    Full grown male pupae of the cotton leaf worm, Spodoptera Littoralis (Boisd.) were gamma irradiated with low doses of 25, 50,75, and 100 Gy. The effects on reproduction, development and sex ratio were the biological aspects studied among P{sub 1}, F{sub 1}, F{sub 2}, F{sub 3} generations. Fecundity of normal females mated with F{sub 1} or F{sub 2} males was significantly reduced for all doses. The F{sub 1} males were more sterile than their irradiated parental males, while F{sub 2} males were more fertile F{sub 1} males. Irradiation of P{sub 1} males did not clearly affect neither the percentage of mated females nor the average number of spermatophores per mated females among the individuals of P{sub 1}, F{sub 1}, F{sub 2}, F{sub 3} generations. The percent of larvae surviving to the adult stage was gradually decreased by increasing dose to P{sub 1} male throughout the first three filial generation. The average larval and pupal durations were not affected among the progeny of P{sub 1} males for both males and females. The sex ratio among the progeny of irradiated males was nearly 1:1. 3 tabs.

  2. Cotton Leaf worm: Inherited Effects of Low Doses of Gamma Radiation on The Progeny of Irradiated Males. Vol. 4

    International Nuclear Information System (INIS)

    Sallam, H.A.; El-Naggar, S.M.; Shible, M.M.; El-Dessouki, S.A.; El-Awady, S.M.

    1996-01-01

    Full grown male pupae of the cotton leaf worm, Spodoptera Littoralis (Boisd.) were gamma irradiated with low doses of 25, 50,75, and 100 Gy. The effects on reproduction, development and sex ratio were the biological aspects studied among P 1 , F 1 , F 2 , F 3 generations. Fecundity of normal females mated with F 1 or F 2 males was significantly reduced for all doses. The F 1 males were more sterile than their irradiated parental males, while F 2 males were more fertile F 1 males. Irradiation of P 1 males did not clearly affect neither the percentage of mated females nor the average number of spermatophores per mated females among the individuals of P 1 , F 1 , F 2 , F 3 generations. The percent of larvae surviving to the adult stage was gradually decreased by increasing dose to P 1 male throughout the first three filial generation. The average larval and pupal durations were not affected among the progeny of P 1 males for both males and females. The sex ratio among the progeny of irradiated males was nearly 1:1. 3 tabs

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

    International Nuclear Information System (INIS)

    Feng Zhongsu; Xu Xiao; Liu Fen

    2008-01-01

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

  4. Chemical dosimetry principles in high dose dosimetry

    International Nuclear Information System (INIS)

    Mhatre, Sachin G.V.

    2016-01-01

    In radiation processing, activities of principal concern are process validation and process control. The objective of such formalized procedures is to establish documentary evidence that the irradiation process has achieved the desired results. The key element of such activities is inevitably a well characterized reliable dosimetry system that is traceable to recognized national and international dosimetry standards. Only such dosimetry systems can help establish the required documentary evidence. In addition, industrial radiation processing such as irradiation of foodstuffs and sterilization of health careproducts are both highly regulated, in particular with regard to dose. Besides, dosimetry is necessary for scaling up processes from the research level to the industrial level. Thus, accurate dosimetry is indispensable

  5. Onyx as radiation detector for high doses

    International Nuclear Information System (INIS)

    Teixeira, Maria Inês; Souza, Divanizia N.; Caldas, Linda V.E.

    2011-01-01

    A study of the thermoluminescent (TL) characteristics of white, black and stripped onyx samples is reported in this work. Onyx is a variety of chalcedony, a form of quartz. The onyx stone is considered nobler than marble. The irradiations were performed using a Gamma-Cell 220 system ( 60 Co). The TL emission curves presented two peaks around 150 °C and 210 °C for all samples. The dose–response curves showed a sublinear behavior between 0.5 Gy and 5 kGy, and the lower detection limit for the white onyx pellets was 1.5 mGy. The main dosimetric characteristics were studied, and the material showed good performance for high dose dosimetry.

  6. The application of high dose food irradiation

    International Nuclear Information System (INIS)

    Bruyn, I. De

    1997-01-01

    During the 1950's to end 1970's the United States Army developed the basic methodology to produce shelf stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive 'dried cooked' taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 25 to 45 kGy (depending on the product) at a temperature of between -20 and -40 Centigrade to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions. The product can be guaranteed for more than two years as long as the integrity of the packaging is maintained. (Author)

  7. The application of high dose food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bruyn, I. De [Atomic Energy Corporation of South Africa LTD, Building 2000, P.O. Box 582, Pretoria 0001, (South Africa)

    1997-12-31

    During the 1950`s to end 1970`s the United States Army developed the basic methodology to produce shelf stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive `dried cooked` taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 25 to 45 kGy (depending on the product) at a temperature of between -20 and -40 Centigrade to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions. The product can be guaranteed for more than two years as long as the integrity of the packaging is maintained. (Author)

  8. Sensation seeking in males involved in recreational high risk sports

    OpenAIRE

    M Guszkowska; A Bołdak

    2010-01-01

    The study examined sensation seeking intensity level in males involved in recreational high risk sports and investigated whether its level depends on type of sport practised. Additionally, in case of parachutists, sport experience of study participants were scrutinised with regard to its possible impact on the level of sensation seeking.The research involved 217 males aged 17 to 45, practising recreational high risk sports, namely: parachuting (n=98); wakeboarding (n=30); snowboarding (n=30);...

  9. The effect of a single dose of morphine on muscle fatigue indices in male rats

    Directory of Open Access Journals (Sweden)

    Sedigheh Amiresmaili

    2016-09-01

    Full Text Available Background and Aim: Endogenous opioids and addictive opiate drugs change many body functions. . Previous studies have referred to the effects of morphine on smooth and pulmonary muscles ., but the  effects of opioids on skeletal muscles is not known well. Thus, the current study aimed at assessing the effect of a single dose of morphine on muscle fatigue in male rats. Materials and Methods: In this experimental study, 40 male Wistar rats weighing 220-270 g were randomly divided into four equal groups: control (the mice were kept in their cages and received food and water, morphine receiving group, fatigue group (the mice in this group were kept running on  a treadmill . for120 minutes at a rate of 20 meters per minute, and morphine plus fatigue group. At the end of the experiments, blood samples were obtained from the corner of their eyes and were sent to the laboratory for measurement of muscle fatigue indexes including lactate dehydrogenase (LDH and creatine phosphokinase (CPK. Results: Administration of morphine to the fatigue group decreased running time compared with the control group (P=0.009. Furthermore, administration of morphine to the fatigue group significantly increased serum levels of LDH (P=0.009 and CPK (P=0.008. Conclusion: The present study showed that administration of a single dose of morphine in rats increases muscle fatigue biomarkers (LDH, CPK.

  10. High dose tetrabromobisphenol A impairs hippocampal neurogenesis and memory retention.

    Science.gov (United States)

    Kim, Ah Hyun; Chun, Hye Jeong; Lee, Seulah; Kim, Hyung Sik; Lee, Jaewon

    2017-08-01

    Tetrabromobisphenol A (TBBPA) is a brominated flame retardant that is commonly used in commercial and household products, such as, computers, televisions, mobile phones, and electronic boards. TBBPA can accumulate in human body fluids, and it has been reported that TBBPA possesses endocrine disruptive activity. However, the neurotoxic effect of TBBPA on hippocampal neurogenesis has not yet been investigated. Accordingly, the present study was undertaken to evaluate the effect of TBBPA on adult hippocampal neurogenesis and cognitive function. Male C57BL/6 mice were orally administrated vehicle or TBBPA (20 mg/kg, 100 mg/kg, or 500 mg/kg daily) for two weeks. TBBPA was observed to significantly and dose-dependently reduce the survival of newly generated cells in the hippocampus but not to affect the proliferation of newly generated cells. Numbers of hippocampal BrdU and NeuN positive cells were dose-dependently reduced by TBBPA, indicating impaired neurogenesis in the hippocampus. Interestingly, glial activation without neuronal death was observed in hippocampi exposed to TBBPA. Furthermore, memory retention was found to be adversely affected by TBBPA exposure by a mechanism involving suppression of the BDNF-CREB signaling pathway. The study suggests high dose TBBPA disrupts hippocampal neurogenesis and induces associated memory deficits. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Limitations of high dose carrier based formulations.

    Science.gov (United States)

    Yeung, Stewart; Traini, Daniela; Tweedie, Alan; Lewis, David; Church, Tanya; Young, Paul M

    2018-06-10

    This study was performed to investigate how increasing the active pharmaceutical ingredient (API) content within a formulation affects the dispersion of particles and the aerosol performance efficiency of a carrier based dry powder inhalable (DPI) formulation, using a custom dry powder inhaler (DPI) development rig. Five formulations with varying concentrations of API beclomethasone dipropionate (BDP) between 1% and 30% (w/w) were formulated as a multi-component carrier system containing coarse lactose and fine lactose with magnesium stearate. The morphology of the formulation and each component were investigated using scanning electron micrographs while the particle size was measured by laser diffraction. The aerosol performance, in terms of aerodynamic diameter, was assessed using the British pharmacopeia Apparatus E cascade impactor (Next generation impactor). Chemical analysis of the API was observed by high performance liquid chromatography (HPLC). Increasing the concentration of BDP in the blend resulted in increasing numbers and size of individual agglomerates and densely packed BDP multi-layers on the surface of the lactose carrier. BDP present within the multi-layer did not disperse as individual primary particles but as dense agglomerates, which led to a decrease in aerosol performance and increased percentage of BDP deposition within the Apparatus E induction port and pre-separator. As the BDP concentration in the blends increases, aerosol performance of the formulation decreases, in an inversely proportional manner. Concurrently, the percentage of API deposition in the induction port and pre-separator could also be linked to the amount of micronized particles (BDP and Micronized composite carrier) present in the formulation. The effect of such dose increase on the behaviour of aerosol dispersion was investigated to gain greater insight in the development and optimisation of higher dosed carrier-based formulations. Copyright © 2018 Elsevier B.V. All

  12. Juvenile Male Rats Exposed to a Low-Dose Mixture of Twenty-Seven Environmental Chemicals Display Adverse Health Effects

    DEFF Research Database (Denmark)

    Hadrup, Niels; Svingen, Terje; Egebjerg, Karen Mandrup

    2016-01-01

    of 27 chemicals administered orally to juvenile male rats for three months could leave a pathophysiological footprint. The mixture contained metals, perfluorinated compounds, PCB, dioxins, pesticides, heterocyclic amines, phthalate, PAHs and others, with a combined dose of 0.16 (Low dose), 0.47 (Mid...

  13. 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).

  14. The Academic Experience of Male High School Students with ADHD

    OpenAIRE

    Kent, Kristine M.; Pelham, William E.; Molina, Brooke S. G.; Sibley, Margaret H.; Waschbusch, Daniel A.; Yu, Jihnhee; Gnagy, Elizabeth M.; Biswas, Aparajita; Babinski, Dara E.; Karch, Kathryn M.

    2011-01-01

    This study compared the high school academic experience of adolescents with and without childhood ADHD using data from the Pittsburgh ADHD Longitudinal Study (PALS). Participants were 326 males with childhood ADHD and 213 demographically similar males without ADHD who were recruited at the start of the follow-up study. Data were collected yearly from parents, teachers and schools. The current study used assessment points at which the participants were currently in or had recently completed gr...

  15. ELDRS Characterization for a Very High Dose Mission

    Science.gov (United States)

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

    2010-01-01

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

  16. Pharmacokinetics of high-dose intravenous melatonin in humans

    DEFF Research Database (Denmark)

    Andersen, Lars P H; Werner, Mads U; Rosenkilde, Mette Marie

    2016-01-01

    This crossover study investigated the pharmacokinetics and adverse effects of high-dose intravenous melatonin. Volunteers participated in 3 identical study sessions, receiving an intravenous bolus of 10 mg melatonin, 100 mg melatonin, and placebo. Blood samples were collected at baseline and 0, 60......, 120, 180, 240, 300, 360, and 420 minutes after the bolus. Quantitative determination of plasma melatonin concentrations was performed using a radioimmunoassay technique. Pharmacokinetic parameters were estimated by a compartmental pharmacokinetic analysis. Adverse effects included assessments...... of sedation and registration of other symptoms. Sedation, evaluated as simple reaction times, was measured at baseline and 120, 180, 300, and 420 minutes after the bolus. Twelve male volunteers completed the study. Median (IQR) Cmax after the bolus injections of 10 mg and 100 mg of melatonin were 221...

  17. Brachytherapy treatment with high dose rate

    International Nuclear Information System (INIS)

    Santana Rodriguez, Sergio Marcelino; Rodriguez Rodriguez, Lissi Lisbet; Ciscal Chiclana, Onelio Alberto

    2009-01-01

    Retrospectively analyze results and prognostic factors of cervical cancer patients treated with radio concomitant cisplatin-based chemotherapy, radiation therapy combined modality. Methods: From January 2003 to December 2007, 198 patients with invasive cervical cancer were treated at the Oncology Department of Hospital Robau Celestino Hernandez (brachytherapy performed at INOR). The most common age group was 31 to 40 years. The histology in squamous cell carcinoma accounted for 84.3% of cases. The treatment consisted of external pelvic irradiation and vaginal brachytherapy, high dose rate. Concomitant chemotherapy consisted of cisplatin 40 mg/m2 weekly with a maximum of 70 mg for 5 weeks. Results: 66.2% of patients completed 5 cycles of chemotherapy. The median overall survival was 39 months, overall survival, disease-free survival and survival free of locoregional recurrence at 5 years of 78%, 76% and 78.6% respectively .. We found that clinical stage, histological type (adenocarcinoma worst outcome) were statistically related to level of response. Conclusions: Treatment with external pelvic radiation, brachytherapy and concurrent weekly cisplatin in patients with stage IIIB cervical cancer is feasible in the Chilean public health system, well tolerated and results comparable to international literature. (Author)

  18. Novel high dose rate lip brachytherapy technique to improve dose homogeneity and reduce toxicity by customized mold

    International Nuclear Information System (INIS)

    Feldman, Jon; Appelbaum, Limor; Sela, Mordechay; Voskoboinik, Ninel; Kadouri, Sarit; Weinberger, Jeffrey; Orion, Itzhak; Meirovitz, Amichay

    2014-01-01

    The purpose of this study is to describe a novel brachytherapy technique for lip Squamous Cell Carcinoma, utilizing a customized mold with embedded brachytherapy sleeves, which separates the lip from the mandible, and improves dose homogeneity. Seven patients with T2 lip cancer treated with a “sandwich” technique of High Dose Rate (HDR) brachytherapy to the lip, consisting of interstitial catheters and a customized mold with embedded catheters, were reviewed for dosimetry and outcome using 3D planning. Dosimetric comparison was made between the “sandwich” technique to “classic” – interstitial catheters only plan. We compared dose volume histograms for Clinical Tumor Volume (CTV), normal tissue “hot spots” and mandible dose. We are reporting according to the ICRU 58 and calculated the Conformal Index (COIN) to show the advantage of our technique. The seven patients (ages 36–81 years, male) had median follow-up of 47 months. Four patients received Brachytherapy and External Beam Radiation Therapy, 3 patients received brachytherapy alone. All achieved local control, with excellent esthetic and functional results. All patients are disease free. The Customized Mold Sandwich technique (CMS) reduced the high dose region receiving 150% (V150) by an average of 20% (range 1–47%), The low dose region (les then 90% of the prescribed dose) improved by 73% in average by using the CMS technique. The COIN value for the CMS was in average 0.92 as opposed to 0.88 for the interstitial catheter only. All differences (excluding the low dose region) were statistically significant. The CMS technique significantly reduces the high dose volume and increases treatment homogeneity. This may reduce the potential toxicity to the lip and adjacent mandible, and results in excellent tumor control, cosmetic and functionality

  19. Effect of kasoline on male rats reproductive system in control and after irradiation in low dose

    International Nuclear Information System (INIS)

    Konoplya, E.F.; Vereshchako, G.G.; Khodosovskaya, A.M.

    2006-01-01

    It was studied morphofunctional status of reproductive system and several haematological parameters of male rats after administration of kasoline without any another treatment or before following irradiation in low dose (1 Gy). Kasoline is biological active substance obtained from castoreum. In intact animals this medical drug heightened relative weight of testis, epidydimisis, prostate gland and seminal vesicles; number of mature sex cells, extracted from epidydimisis and DNA contents in testiculare tissue. Kasoline possesses specific radioprotective properties that resulted in restoration of leukocytes number in blood, in grown number of spermatozoids, extracted from epidydimisis, and considerable increase of DNA value in the testis tissue. Obtained effects were more prominent at 30 and 90 days after irradiation. (authors)

  20. Mental skills of South African male high school rugby players ...

    African Journals Online (AJOL)

    The aim of this study was to establish preliminary South African high school rugby norms for the BMSQ. The sample consisted of 152 male high school rugby players from two schools in the Ethekwini region. Preliminary norms are presented in the form of means and standard deviations. Results are compared with those of ...

  1. Acceleration of skin wound healing by low-dose indirect ionizing radiation in male rats.

    Science.gov (United States)

    Jabbari, Nasrollah; Farjah, Gholam Hossein; Ghadimi, Behnam; Zanjani, Hajar; Heshmatian, Behnam

    2017-08-01

    A recent hypothesis has revealed that low-dose irradiation (LDI) with ionizing radiation might have a promoting effect on fracture healing. The aim of this study was to investigate the influence of direct (electron beam) and indirect (gamma-ray) low-dose ionizing irradiations on the wound healing process in male rats. In 72 male rats, a full-thickness wound was incised. The animals were randomly assigned to three groups, each with 24 rats. The first two groups were named IG-I and IG-II and respectively exposed to electron and gamma-radiations (75 cGy) immediately after the surgical procedure. The third group was considered as the control (CG) and remained untreated. Skin biopsies from the subgroups were collected on days 3, 7, 15, and 21 after the operation and evaluated using histological and biomechanical methods. Data were analyzed by one-way ANOVA, followed by Tukey's post hoc test using SPSS 20 software. Histological studies of tissues showed that the mean number of fibroblasts, macrophages, blood vessel sections, and neutrophils on the third and seventh days after the surgery in the gamma-treated group was higher than that in both other groups. In contrast, on day 21, the mean number of mentioned cells in the gamma-treated group was lower than in the other two groups. In addition, the mean maximum stress value was significantly greater in the gamma-treated group. Results of this study showed that gamma-ray irradiation is effective in the acceleration of wound healing. Copyright © 2017. Published by Elsevier Taiwan.

  2. Acceleration of skin wound healing by low-dose indirect ionizing radiation in male rats

    Directory of Open Access Journals (Sweden)

    Nasrollah Jabbari

    2017-08-01

    Full Text Available A recent hypothesis has revealed that low-dose irradiation (LDI with ionizing radiation might have a promoting effect on fracture healing. The aim of this study was to investigate the influence of direct (electron beam and indirect (gamma-ray low-dose ionizing irradiations on the wound healing process in male rats. In 72 male rats, a full-thickness wound was incised. The animals were randomly assigned to three groups, each with 24 rats. The first two groups were named IG–I and IG–II and respectively exposed to electron and gamma-radiations (75 cGy immediately after the surgical procedure. The third group was considered as the control (CG and remained untreated. Skin biopsies from the subgroups were collected on days 3, 7, 15, and 21 after the operation and evaluated using histological and biomechanical methods. Data were analyzed by one-way ANOVA, followed by Tukey's post hoc test using SPSS 20 software. Histological studies of tissues showed that the mean number of fibroblasts, macrophages, blood vessel sections, and neutrophils on the third and seventh days after the surgery in the gamma-treated group was higher than that in both other groups. In contrast, on day 21, the mean number of mentioned cells in the gamma-treated group was lower than in the other two groups. In addition, the mean maximum stress value was significantly greater in the gamma-treated group. Results of this study showed that gamma-ray irradiation is effective in the acceleration of wound healing.

  3. High-dose zolpidem dependence - Psychostimulant effects? A case report and literature review

    Directory of Open Access Journals (Sweden)

    Abhijna Chandan Chattopadhyay

    2016-01-01

    Full Text Available Zolpidem, an imidazoline nonbenzodiazepine sedative drug, is used widely. Initial reports showed minimal abuse potential. However, multiple reports have appeared of dose escalation and abuse. Subjective effects of high-dose zolpidem are not known. In light of accumulating evidence of abuse potential, we hereby report a case of high-dose dependence and a review of relevant literature. A 33-year-old male presented with 5 years of daily use of 600–1700 mg of zolpidem tartrate. He reported subjective effects of euphoria, intense craving, and inability to stop use. Loss of receptor specificity, pharmacokinetic factors, and different receptor distributions can explain paradoxical stimulatory effects of high-dose zolpidem. Further studies are required to characterize subjective effects of high-dose zolpidem.

  4. High dose potassium-nitrate chemical dosimeter

    International Nuclear Information System (INIS)

    Dorda de Cancio, E.M.; Munoz, S.S.

    1982-01-01

    This dosimeter is used to control 10 kGY-order doses (1 Mrad). Nitrate suffers a radiolitic reduction phenomena, which is related to the given dose. The method to use potassium nitrate as dosimeter is described, as well as effects of the temperature of irradiation, pH, nitrate concentration and post-irradiation stability. Nitrate powder was irradiated at a Semi-Industrial Plant, at Centro Atomico Ezeiza, and also in a Gammacell-220 irradiator. The dose rates used were 2,60 and 1,80 KGY/hour, and the given doses varied between 1,0 and 150 KGY. The uncertainty was +-3% in all the range. (author) [es

  5. Dose-Effect Relationship of Alkylating Agents on Testicular Function in Male Survivors of Childhood Lymphoma.

    Science.gov (United States)

    Servitzoglou, Marina; De Vathaire, Florent; Oberlin, Odile; Patte, Catherine; Thomas-Teinturier, Cécile

    2015-01-01

    The purpose of our study was to assess the gonadal function in male survivors of childhood lymphoma. We studied 171 male survivors of childhood lymphoma (83 with B-cell non-Hodgkin lymphoma [B-NHL], 32 with T-cell non-Hodgkin lymphoma [T-NHL], 50 with Hodgkin lymphoma [HL], and 6 with anaplastic large-cell lymphoma [ALCL]), measuring follicle-stimulating hormone [FSH] and luteinizing hormone [LH] levels at a median age of 21.1 (17-30.4) years after a median delay of 9.3 (2-22.4) years from treatment. FSH levels were above normal range (≥10 IU/L) in 42.1% and LH levels ≥8 IU/L in only 8.9% of survivors. In multivariate analysis, only the following chemotherapeutic agents were associated with higher FSH or LH levels: cyclophosphamide (P alkylating agents on childhood lymphoma survivors is dose dependent and not correlated to diagnosis, age, or pubertal status at diagnosis.

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

    International Nuclear Information System (INIS)

    Sohrabi, M.

    1997-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  8. High dose radiotherapy for pituitary tumours

    International Nuclear Information System (INIS)

    Mead, K.W.

    1981-01-01

    The results of treatment of 120 pituitary tumours are presented. Based on this experience operable chromophobe adenomas are now treated with 5,000 rads in 4 weeks and inoperable ones receive an additional central dose to 7,500 rads. Pituitary Cushing's tumours are given 10,000 rads in 5 weeks using small fields and acromegalics 5,000 rads to the whole sella and 7,500 to its lower half. The absence of complications at these dose levels is attributed to the use of small fields and the precise application of treatment

  9. High dose radiotherapy for pituitary tumours

    Energy Technology Data Exchange (ETDEWEB)

    Mead, K.W. (Queensland Radium Inst., Herston (Australia))

    1981-11-01

    The results of treatment of 120 pituitary tumours are presented. Based on this experience operable chromophobe adenomas are now treated with 5,000 rads in 4 weeks and inoperable ones receive an additional central dose to 7,500 rads. Pituitary Cushing's tumours are given 10,000 rads in 5 weeks using small fields and acromegalics 5,000 rads to the whole sella and 7,500 to its lower half. The absence of complications at these dose levels is attributed to the use of small fields and the precise application of treatment.

  10. Relative safety profiles of high dose statin regimens

    Directory of Open Access Journals (Sweden)

    Carlos Escobar

    2008-06-01

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

  11. Evaluation of the dose uniformity for double-plane high dose rate interstitial breast implants with the use of dose reference points and dose non-uniformity ratio

    International Nuclear Information System (INIS)

    MAjor, T.; Polgar, C.; Somogyi, A.; Nemeth, G.

    2000-01-01

    This study investigated the influence of dwell time optimizations on dose uniformity characterized by dose values in dose points and dose non-uniformity ratio (DNR) and analyzed which implant parameters have influence on the DNR. Double-plane breast implants with catheters arranged in triangular pattern were used for the calculations. At a typical breast implant, dose values in dose reference points inside the target volume and volumes enclosed by given isodose surfaces were calculated and compared for non-optimized and optimized implants. The same 6-cm treatment length was used for the comparisons. Using different optimizations plots of dose non-uniformity ratio as a function of catheter separation, source step size, number of catheters, length of active sections were drawn and the minimum DNR values were determined. Optimization resulted in less variation in dose values over dose points through the whole volume and in the central plane only compared to the non-optimized case. At implant configurations consisting of seven catheters with 15-mm separation, 5-mm source step size and various active lengths adapted according to the type of optimization, the no optimization, geometrical (volume mode) and dose point (on dose points and geometry) optimization resulted in similar treatment volumes, but an increased high dose volume was observed due to the optimization. The dose non-uniformity ratio always had the minimum at average dose over dose normalization points, defined in the midpoints between the catheters through the implant volume. The minimum value of DNR depended on catheter separation, source step size, active length and number of catheters. The optimization had only a small influence on DNR. In addition to the reference points in the central plane only, dose points positioned in the whole implant volume can be used for evaluating the dose uniformity of interstitial implants. The dose optimization increases not only the dose uniformity within the implant but

  12. Dosimetry in high dose rate endoluminal brachytherapy

    International Nuclear Information System (INIS)

    Uno, Takashi; Kotaka, Kikuo; Itami, Jun

    1994-01-01

    In endoluminal brachytherapy for the tracheobronchial tree, esophagus, and bile duct, a reference point for dose calculation has been often settled at 1 cm outside from the middle of source travel path. In the current study, a change in the ratio of the reference point dose on the convex to concave side (Dq/Dp) was calculated, provided the source travel path bends as is the case in most endoluminal brachytherapies. Point source was presumed to move stepwise at 1 cm interval from 4 to 13 locations. Retention time at each location was calculated by personal computer so as to deliver equal dose at 1 cm from the linear travel path. With the retention time remaining constant, the change of Dq/Dp was assessed by bending the source travel path. Results indicated that the length of the source travel path and radius of its curve influenced the pattern of change in Dq/Dp. Therefore, it was concluded that the difference in reference dose on the convex and concave side of the curved path is not negligible under certain conditions in endoluminal brachytherapy. In order to maintain the ratio more than 0.9, relatively greater radius was required when the source travel path was decreased. (author)

  13. Cutaneous dosimetry at low and high dose

    International Nuclear Information System (INIS)

    Martin, M.

    2009-01-01

    As radiodermatitis is a complication related to the exposure to ionizing radiation after an accidental exposition or a medical examination (radiotherapy or interventional radiology), the author briefly reports an investigation of the response of the human keratinocyte to irradiation for different dose levels, and the search for exposure markers

  14. Gynogenesis with high doses of gamma radiation in tomatoes -Lycopersicum esculentum Mill. (L.)

    International Nuclear Information System (INIS)

    Dryanovska, O.A.

    1983-01-01

    The behaviour of male chromatin at the germination of gamma irradiated pollen from the stigma to the embrio sac in tomatoes was investigated in connection with the induced gynogenesis and the transfer of genetic information from one species to another. Two male-sterile longistil varieties of Deva and Hera were used as mothers, while mixed pollen from cultivated varieties and Lycopersicum peruvianum (L.) was irradiated at doses of 1, 5, 10 and 200 Kr with a dose rate of up to 1500 R/min. The experiment was carried out in 6 replications, with between 3 and 15 flowers for each variant and variety. The irradiated male chromatin of L. peruvianum remains in the pollen tube that has grown close to the embryo sac and stimulates the development of the embryo and endosperm. The absense of anthocyanin and the normal diploid chromosome count were the two markers for characterizing the plants obtained at high doses of gamma radiation as secondarily diploidized gynogenetic diplo-haploids during embryogenesis. It is assumed that the highly damaged male chromatin and the cytoplasm of the pollen tube retain their stimulating function under the influence of the high doses. A decisive role may be placed by certain fragments with genes from the male chromatin. The mitochondria which retain their respirative capacity and are promptly restored even after irradiation may have a stimmulating influence at the induced haploidy. The secondary diploidization normalizes the development of the organism of haploid origin and makes it possible to overcome the poor viability and the higher sterility. The genes responsible for the synthesis of anthocyanin in the irradiated male chromatin are restroyed by the high radiation doses, and this is the reason for the absence of anthocyanin in the diplo-haploid plants

  15. Sensation seeking in males involved in recreational high risk sports

    Directory of Open Access Journals (Sweden)

    M Guszkowska

    2010-09-01

    Full Text Available The study examined sensation seeking intensity level in males involved in recreational high risk sports and investigated whether its level depends on type of sport practised. Additionally, in case of parachutists, sport experience of study participants were scrutinised with regard to its possible impact on the level of sensation seeking.The research involved 217 males aged 17 to 45, practising recreational high risk sports, namely: parachuting (n=98; wakeboarding (n=30; snowboarding (n=30; scuba diving (n=22; alpinism (n=20; paragliding (n=17. The control group included 54 men not involved in sports. Polish version of Sensation Seeking Scale (SSS-IV of Zuckerman was applied.Results show, that high risk sports males are featured by stronger need of sensations in comparison to control group and this concerned all but one aspect of sensation seeking variable. The only exception was the need of intellectual stimulation. Except from the thrill and adventure seeking dimension, type of sport may also be an important determinant of sensation seeking. Men practising snowboard and wakeboard presented stronger need for sensations, especially in the dimension of experience seeking, disinhibition and boredom susceptibility. Sport experience (number of jumps in parachuting did not differentiate the level of sensation seeking among investigated parachutists. Population of sport high risk male takers was not homogeneous, and therefore in future research one should analyse specific sports (or events in a certain sport separately.

  16. Dose volume assessment of high dose rate 192IR endobronchial implants

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  17. Statistical behavior of high doses in medical radiodiagnosis; Comportamento estatistico das altas doses em radiodiagnostico medico

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Adriana Elisa, E-mail: adrianaebarboza@gmail.com, E-mail: elisa@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

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

  18. Mortality of tyrophagus putrescentiae (Schrank) females exposed to a high ratio of gamma-irradiated males as an index of radiation impact on sexual vigor of males

    International Nuclear Information System (INIS)

    Ignatowicz, S.

    1990-01-01

    A 40 or 60 krad dose of gamma radiation reduce slightly sexual activity of the males but male activity is greatly reduced as the radiation dose increases from 60 to 120 krad. Females of the mold mite, Tyrophagus, putrescentiae (Schrank), molested by males present at a 3:1 or 5:1 ratio live shorter than females kept with one male. The SAG test can be applied to compare sexual activity of males treated with different dosage of gamma irradiation

  19. measurement of high dose radiation using yellow perspex dosimeter

    International Nuclear Information System (INIS)

    Thamrin, M Thoyib; Sofyan, Hasnel

    1996-01-01

    Measurement of high dose radiation using yellow perspex dosemeter has been carried out. Dose range used was between 0.1 to 3.0 kGy. Measurement of dose rate against Fricke dosemeter as a standard dose meter From the irradiation of Fricke dosemeter with time variation of 3,6,9,12,15 and 18 minute, it was obtained average dose rate of 955.57 Gy/hour, linear equation of dose was Y= 2.333+15.776 X with its correlation factor r = 0.9999. Measurement result using yellow perspex show that correlation between net optical density and radiation dose was not linear with its equation was ODc exp. [Bo + In(dose).Bi] Value of Bo = -0.215 and Bi=0.5020. From the experiment it was suggested that routine dosimeter (yellow perspex) should be calibrated formerly against standard dosemeters

  20. Methodology of high dose research in medical radiodiagnostic

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    1991-03-01

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

  2. Study on radiation dose and its protection for the physician performing the retrograde urethrography for male

    International Nuclear Information System (INIS)

    Inui, Saburo; Suzuki, Toshiyuki; Kashino, Teiichi; Abe, Hitoshi.

    1982-01-01

    The status quo of the various techniques used in retrograde urethrography (R.U.) is examined by the questionnaire method with the data of radiation doses to medical personnels, and new methods are devised to reduce unnecessary radiation dose. Manual injection of the radio-opaquee contrast medium has been employed by 92.5% out of 8,259 physicians in 67 institutions. They expose themselves as well as patients to the radiation during the course of the examination. In most of these occasions the physician is not sufficiently protected from radiation leaving the possibility of his somatic damage. From these observations, the followings were studied: 1) Application of our newly developed protective barrier, exclusive for R.U., made of lead-impregnated acryl-resin plate (KYOW GLAS-XA). 2) Employment of the high speed screen made of rare earth metal. The results were encouraging in reducing the radiation exposure dose. In conclusion, the employment of the above two methods are efficient in obviating unnecessary radiation exposure to the physician during R.U. (author)

  3. Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

    International Nuclear Information System (INIS)

    Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

    2016-01-01

    In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

  4. High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Was, Gary; Wirth, Brian; Motta, Athur; Morgan, Dane; Kaoumi, Djamel; Hosemann, Peter; Odette, Robert

    2018-04-30

    Project Objective: The objective of this proposal is to demonstrate the capability to predict the evolution of microstructure and properties of structural materials in-reactor and at high doses, using ion irradiation as a surrogate for reactor irradiations. “Properties” includes both physical properties (irradiated microstructure) and the mechanical properties of the material. Demonstration of the capability to predict properties has two components. One is ion irradiation of a set of alloys to yield an irradiated microstructure and corresponding mechanical behavior that are substantially the same as results from neutron exposure in the appropriate reactor environment. Second is the capability to predict the irradiated microstructure and corresponding mechanical behavior on the basis of improved models, validated against both ion and reactor irradiations and verified against ion irradiations. Taken together, achievement of these objectives will yield an enhanced capability for simulating the behavior of materials in reactor irradiations

  5. An evaluation of high-dose jobs for ALARA improvement

    International Nuclear Information System (INIS)

    Mun, J. H.; Kim, H. S.

    1997-01-01

    It is well known that about 70 percent of occupational dose have incurred from maintenance jobs at outage period. To reduce occupational dose, first, the high-dose jobs at the outage period should be identified and evaluated. For this, the database program is used, which contains the ORE data of reference plants, Kori Units 3 and 4. As a result, it is found that the jobs related to steam generator are the highest dose jobs in terms of collective ORE dose. From the analysis of the job procedures of those jobs, the ALARA improvements are also derived

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-04-01

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

  7. Acute renal failure in high dose carboplatin chemotherapy

    NARCIS (Netherlands)

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

    1995-01-01

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

  8. Pharmacogenetics and Pharmacokinetics in high-dose alkylating chemotherapy

    NARCIS (Netherlands)

    Ekhart, G.C. (Corine)

    2008-01-01

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

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

    NARCIS (Netherlands)

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

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

  10. Estimation of the transit dose component in high dose rate brachytherapy

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  11. Statistical behavior of high doses in medical radiodiagnosis

    International Nuclear Information System (INIS)

    Barboza, Adriana Elisa

    2014-01-01

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

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

    Science.gov (United States)

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

    2002-06-01

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

  14. Accelerated Irradiations for High Dose Microstructures in Fast Reactor Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zhijie [Univ. of Michigan, Ann Arbor, MI (United States)

    2017-03-31

    The objective of this project is to determine the extent to which high dose rate, self-ion irradiation can be used as an accelerated irradiation tool to understand microstructure evolution at high doses and temperatures relevant to advanced fast reactors. We will accomplish the goal by evaluating phase stability and swelling of F-M alloys relevant to SFR systems at very high dose by combining experiment and modeling in an effort to obtain a quantitative description of the processes at high and low damage rates.

  15. Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

    International Nuclear Information System (INIS)

    Turesson, I.

    1990-01-01

    The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

  16. High-temperature absorbed dose measurements in the megagray range

    International Nuclear Information System (INIS)

    Balian, P.; Ardonceau, J.; Zuppiroli, L.

    1988-01-01

    Organic conductors of the tetraselenotetracene family have been tested as ''high-temperature'' absorbed dose dosimeters. They were heated up to 120 0 C and irradiated at this temperature with 1-MeV electrons in order to simulate, in a short time, a much longer γ-ray irradiation. The electric resistance increase of the crystal can be considered a good measurement of the absorbed dose in the range 10 6 Gy to a few 10 8 Gy and presumably one order of magnitude more. This dosimeter also permits on-line (in-situ) measurements of the absorbed dose without removing the sensor from the irradiation site. The respective advantages of organic and inorganic dosimeters at these temperature and dose ranges are also discussed. In this connection, we outline new, but negative, results concerning the possible use of silica as a high-temperature, high-dose dosimeter. (author)

  17. Dose reduction during CT scanning in an anthropomorphic phantom by the use of a male gonad shield.

    Science.gov (United States)

    Price, R; Halson, P; Sampson, M

    1999-05-01

    Shielding the radiosensitive gonads during X-ray exposure has been advocated for plain film radiography for many years. In the UK, gonad shields are not widely employed in routine CT scanning, possibly owing to a perceived difficulty in protecting the gonads from a multidirectional X-ray source. The increasing numbers of CT scanners in the UK, with the large doses they deliver to patients, make potential dose reduction methods an important issue. This study measures the dose reduction achievable by shielding the male gonads with a lead wrap-around protection device. The reductions in dose when shielded both from direct radiation and from indirect radiation scattered from local tissues were studied. The use of the device resulted in a statistically significant reduction in the absorbed testicular dose from both direct and scattered radiation, with no increase in the dose measured in surrounding tissues. In three clinically relevant experimental protocols where the testes were not irradiated directly, the testicular absorbed dose from indirect scatter was reduced by 77-93% of the corresponding non-shielded figure. In these three experiments, image quality was unaltered by the use of the shield. A larger dose reduction was obtained when the shield was used to protect the testes from direct irradiation. However, this was achieved at the expense of considerable image degradation from streak artefact that would effectively prevent the clinical use of the device in this setting.

  18. Radiophotoluminescence light scope for high-dose dosimetry

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  19. Relevance of high-dose chemotherapy in solid tumours

    NARCIS (Netherlands)

    Nieboer, P; de Vries, EGE; Mulder, NH; van der Graaf, WTA

    Drug resistance is a major problem in the treatment of solid tumours. Based on a steep dose-response relationship for especially alkylating agents on tumour cell survival, high-dose chemotherapy was considered of interest for the treatment of solid tumours. Results of phase 1 and 2 studies with

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  1. Male and female hypogonadism are highly prevalent in South Africans with Addison's disease.

    Science.gov (United States)

    Ross, I L; Levitt, N S; Blom, D J; Haarburger, D

    2014-09-01

    Hypogonadism may complicate Addison's disease (primary hypoadrenalism), but prevalence and metabolic sequelae of hypogonadism in Addison's disease are poorly described. We recruited patients from the South African Addison's disease national registry who received stable replacement doses of hydrocortisone and had no acute illness. Male biochemical testosterone deficiency was defined as an early morning basal testosterone10 or 12 IU/l). Testosterone deficiency did not correlate with age, disease duration or hydrocortisone dose. Untreated male hypogonadal subjects had a higher (mean ± standard deviation) BMI compared to eugonadal subjects 29.2 ± 4.9 kg/m(2) vs. 24.7 ± 3.4 kg/m(2) (p=0.01) and a higher median (interquartile range) high-sensitive-CRP 6.4 (2.5-14.0) mg/l vs. 1.45 (0.6-2.8) mg/l (p=0.002). There were no differences between the 2 groups in lipids, lipoproteins and fasting glucose. The median (interquartile range) DHEAS was lower in the hypogonadal 0.31 (0.27-0.37) μmol/l, compared with the eugonadal group 0.75 (0.50-1.51) μmol/l (p=0.005). POF was documented in 11% of female patients. Male testosterone deficiency was highly prevalent in this cohort and was primarily due to secondary hypogonadism. Only BMI and hs-CRP were increased in untreated male hypogonadal subjects. Male and female hypogonadism appears to be a common complication of Addison's disease and may contribute to its morbidity. © Georg Thieme Verlag KG Stuttgart · New York.

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  3. Augmentation index (AI) in a dose-response relationship with smoking habits in males: The Tanushimaru study.

    Science.gov (United States)

    Tsuru, Tomoko; Adachi, Hisashi; Enomoto, Mika; Fukami, Ako; Kumagai, Eita; Nakamura, Sachiko; Nohara, Yume; Kono, Shoko; Nakao, Erika; Sakaue, Akiko; Morikawa, Nagisa; Fukumoto, Yoshihiro

    2016-12-01

    We investigated the relationship between augmentation index (AI) and smoking habits in community-dwelling Japanese.This cross-sectional study enrolled 1926 subjects (769 males and 1157 females) aged 40 to 95 years who underwent a health check-up in a Japanese cohort of the Seven Countries Study, in Tanushimaru, a typical farming town in Kyushu Island in 2009. The subjects' medical history, alcohol intake, smoking habit, and current medications for hypertension, dyslipidemia, and diabetes were ascertained by questionnaire. Radial arterial pressure wave analysis was used to obtain AI. We analyzed the data stratified by gender.Age-adjusted means of AI in males showed a clear dose-response relationship in 4 categories of smoking habits (P = 0.010). There was no significant relationship between AI and smoking habits in females (P = 0.127). The significant dose-response relationship (P = 0.036) in males between AI and 4 categories of smoking habits still remained even after adjustment for age, body mass index, systolic blood pressure, estimated glomerular filtration rate, glucose, hypertensive medication, and alcohol intake.The present study demonstrated that AI values were significantly associated with smoking habits in a dose-dependent manner in Japanese males.

  4. Hypertonic Saline in Conjunction with High-Dose Furosemide Improves Dose-Response Curves in Worsening Refractory Congestive Heart Failure.

    Science.gov (United States)

    Paterna, Salvatore; Di Gaudio, Francesca; La Rocca, Vincenzo; Balistreri, Fabio; Greco, Massimiliano; Torres, Daniele; Lupo, Umberto; Rizzo, Giuseppina; di Pasquale, Pietro; Indelicato, Sergio; Cuttitta, Francesco; Butler, Javed; Parrinello, Gaspare

    2015-10-01

    Diuretic responsiveness in patients with chronic heart failure (CHF) is better assessed by urine production per unit diuretic dose than by the absolute urine output or diuretic dose. Diuretic resistance arises over time when the plateau rate of sodium and water excretion is reached prior to optimal fluid elimination and may be overcome when hypertonic saline solution (HSS) is added to high doses of furosemide. Forty-two consecutively hospitalized patients with refractory CHF were randomized in a 1:1:1 ratio to furosemide doses (125 mg, 250 mg, 500 mg) so that all patients received intravenous furosemide diluted in 150 ml of normal saline (0.9%) in the first step (0-24 h) and the same furosemide dose diluted in 150 ml of HSS (1.4%) in the next step (24-48 h) as to obtain 3 groups as follows: Fourteen patients receiving 125 mg (group 1), fourteen patients receiving 250 mg (group 2), and fourteen patients receiving 500 mg (group 3) of furosemide. Urine samples of all patients were collected at 30, 60, and 90 min, and 3, 4, 5, 6, 8, and 24 h after infusion. Diuresis, sodium excretion, osmolality, and furosemide concentration were evaluated for each urine sample. After randomization, 40 patients completed the study. Two patients, one in group 2 and one in group 3 dropped out. Patients in group 1 (125 mg furosemide) had a mean age of 77 ± 17 years, 43% were male, 6 (43%) had heart failure with a preserved ejection fraction (HFpEF), and 64% were in New York Heart Association (NYHA) class IV; the mean age of patients in group 2 (250 mg furosemide) was 80 ± 8.1 years, 15% were male, 5 (38%) had HFpEF, and 84% were in NYHA class IV; and the mean age of patients in group 3 (500 mg furosemide) was 73 ± 12 years, 54% were male, 6 (46%) had HFpEF, and 69% were in NYHA class IV. HSS added to furosemide increased total urine output, sodium excretion, urinary osmolality, and furosemide urine delivery in all patients and at all time points. The percentage increase was 18,14, and

  5. High-dose dosimetry using natural silicate minerals

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  6. High-dose dosimetry using natural silicate minerals

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  7. Treatment of the prostate cancer with high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Martinez, Alvaro; Torres Silva, Felipe

    2002-01-01

    The prostate cancer treatment in early stages is controversial. The high dose rate brachytherapy has been used like monotherapy or boost with external beam radiotherapy in advanced disease. This paper describes the technique and the advantages over other modalities

  8. Genetic injury in hybrid male mice exposed to low doses of 60CO γ-rays or fission neutrons. 1

    International Nuclear Information System (INIS)

    Grahn, D.; Carnes, B.A.; Farrington, B.H.; Lee, C.H.

    1984-01-01

    Young adult male B6CF 1 mice were exposed to single whole body doses of fission neutrons or 60 Co γ rays. Postspermatogonial dominant lethal injury, incidence of reciprocal chromosome translocations induced in spermatogonia, incidence of abnormal epididymal sperm 4-6 weeks after exposure, and testis weight loss 3-6 weeks after exposure were all measured. Significant effects were seen at 1 and 2.5 rad of neutrons consistent with extrapolation from higher doses, with the exception of dominant lethal mutations, which occurred in significant excess of expectation. Dose-response functions were linear or linear-quadratic, depending upon end point, radiation quality, and dose range. For translocation frequencies, the D 2 term was negative for neutron and positive for γ-ray irradiations. RBE values varied with dose and end point. For testis weight loss and abnormal sperm over the full dose range, the RBEs were between 5 and 6. They were between 7 and 9 at lower doses (< 10 rad) for translocations. RBEs for postimplantation and total dominant lethal rates were 5-6 above 10 rad and 10-14 below 10 rad. The RBEs for preimplant losses were between 15 and 25 above 10 rad and possibly higher below 10 rad, although the data are statistically 'noisy'. (Auth.)

  9. Sperm parameters in rats after low-dose irradiation of sex cells in male parents during two cycles of gametogenesis

    International Nuclear Information System (INIS)

    Karpenko, N.O.; Chub, N.N.; Brizgalova, G.A.

    2001-01-01

    Chronic combined (internal and external) irradiation in low doses (absorbed doses 0.4 - 3.6 cGy) during two cycles of gametogenesis results in defective stimulation of spermatogenesis in male rats and provokes genotoxic action. The offspring from fathers with 0.7 and 3.6 cGy irradiation have decreased viability and oligozoospermia in mature age. The offsprings from the father with 3.6 cGy have increased sensitivity to weak irradiation and react by increases oligozoospermia. The data are accord with the idea about more pronounced genetic radioresistance of premeiosis cells during gametogenesis

  10. Investigation of PBAT dosimetric properties for high gamma dose dosimetry

    International Nuclear Information System (INIS)

    Cunha, Elisete L.; Schimitberger, Thiago

    2017-01-01

    Poly(butylene adipate-co-terephthalate) (PBAT) is an aliphatic-aromatic copolyester which is biodegradable. It is a non-photoluminescent copolyester that becomes photoluminescent after previous exposure to gamma doses higher than 100 kGy. After the previous high energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a LED source at wavelengths ranging from 370 to 405 nm. In this work we investigated the enhancement of the photoluminescence (PL) and dosimetric properties of PBAT, after exposure to high doses of gamma radiation ranging from 50 to 4,000 kGy. In this investigation we demonstrate that increasing the PBAT film thickness by 100 μm enhances the PL output by 3.5 times, when irradiated with 500 kGy. Also, besides the already known color green brightness, the PL intensity can also be used for high dose dosimetry purposes for doses ranging from 50 to 750 kGy. The FTIR analysis has demonstrated that the there is a linear relationship between peak intensity and dose for doses ranging from 100 and 2,000 kGy for the absorbance peaks at 3,241 cm -1 and 3271 cm -1 , with linear correlation coefficients of 0.9981 and 0.9992, respectively. The results indicate that PBAT has great potential for applications in bio-imaging devices and high gamma dose dosimetry. (author)

  11. Investigation of PBAT dosimetric properties for high gamma dose dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Elisete L.; Schimitberger, Thiago, E-mail: elisete.cunha@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Oliveira, Cristiana M.; Faria, Luiz O., E-mail: farialo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Poly(butylene adipate-co-terephthalate) (PBAT) is an aliphatic-aromatic copolyester which is biodegradable. It is a non-photoluminescent copolyester that becomes photoluminescent after previous exposure to gamma doses higher than 100 kGy. After the previous high energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a LED source at wavelengths ranging from 370 to 405 nm. In this work we investigated the enhancement of the photoluminescence (PL) and dosimetric properties of PBAT, after exposure to high doses of gamma radiation ranging from 50 to 4,000 kGy. In this investigation we demonstrate that increasing the PBAT film thickness by 100 μm enhances the PL output by 3.5 times, when irradiated with 500 kGy. Also, besides the already known color green brightness, the PL intensity can also be used for high dose dosimetry purposes for doses ranging from 50 to 750 kGy. The FTIR analysis has demonstrated that the there is a linear relationship between peak intensity and dose for doses ranging from 100 and 2,000 kGy for the absorbance peaks at 3,241 cm{sup -1} and 3271 cm{sup -1}, with linear correlation coefficients of 0.9981 and 0.9992, respectively. The results indicate that PBAT has great potential for applications in bio-imaging devices and high gamma dose dosimetry. (author)

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

    Directory of Open Access Journals (Sweden)

    Sérgio Carlos Barros Esteves

    2004-10-01

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

  13. Effects of body habitus on internal radiation dose calculations using the 5-year-old anthropomorphic male models

    Science.gov (United States)

    Xie, Tianwu; Kuster, Niels; Zaidi, Habib

    2017-08-01

    Computational phantoms are commonly used in internal radiation dosimetry to assess the amount and distribution pattern of energy deposited in various parts of the human body from different internal radiation sources. Radiation dose assessments are commonly performed on predetermined reference computational phantoms while the argument for individualized patient-specific radiation dosimetry exists. This study aims to evaluate the influence of body habitus on internal dosimetry and to quantify the uncertainties in dose estimation correlated with the use of fixed reference models. The 5-year-old IT’IS male phantom was modified to match target anthropometric parameters, including body weight, body height and sitting height/stature ratio (SSR), determined from reference databases, thus enabling the creation of 125 5-year-old habitus-dependent male phantoms with 10th, 25th, 50th, 75th and 90th percentile body morphometries. We evaluated the absorbed fractions and the mean absorbed dose to the target region per unit cumulative activity in the source region (S-values) of F-18 in 46 source regions for the generated 125 anthropomorphic 5-year-old hybrid male phantoms using the Monte Carlo N-Particle eXtended general purpose Monte Carlo transport code and calculated the absorbed dose and effective dose of five 18F-labelled radiotracers for children of various habitus. For most organs, the S-value of F-18 presents stronger statistical correlations with body weight, standing height and sitting height than BMI and SSR. The self-absorbed fraction and self-absorbed S-values of F-18 and the absorbed dose and effective dose of 18F-labelled radiotracers present with the strongest statistical correlations with body weight. For 18F-Amino acids, 18F-Brain receptor substances, 18F-FDG, 18F-L-DOPA and 18F-FBPA, the mean absolute effective dose differences between phantoms of different habitus and fixed reference models are 11.4%, 11.3%, 10.8%, 13.3% and 11.4%, respectively. Total body

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  15. Proximity correction of high-dosed frame with PROXECCO

    Science.gov (United States)

    Eisenmann, Hans; Waas, Thomas; Hartmann, Hans

    1994-05-01

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

  16. Radiation dose reduction at a price: the effectiveness of a male gonadal shield during helical CT scans

    OpenAIRE

    Erdi Yusuf E; Casciotta Kevin A; Dauer Lawrence T; Rothenberg Lawrence N

    2007-01-01

    Abstract Background It is estimated that 60 million computed tomography (CT) scans were performed during 2006, with approximately 11% of those performed on children age 0–15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-around male pediatric gonad shield was used during CT scanning. This information is obtained to...

  17. [Study of genome instability using DNA fingerprinting of the offspring of male mice subjected to chronic low dose gamma irradiation].

    Science.gov (United States)

    Bezlepkin, V G; Vasil'eva, G V; Lomaeva, M G; Sirota, N P; Gaziev, A I

    2000-01-01

    By a polymerase chain reaction with an arbitrary primer (AP-PCR), the possibility of transmission of genome instability to somatic cells of the offspring (F1 generation) from male parents of mice exposed to chronic low-level gamma-radiation was studied. Male BALB/c mice 15 days after exposure to 10-50 cGy were mated with unirradiated females. Biopsies were taken from tale tips of two month-old offspring mice and DNA was isolated. The primer in the AP-PCR was a 20-mer oligonucleotide flanking the microsatellite locus Atp1b2 on chromosome 11 of the mouse. A comparative analysis of individual fingerprints of AP-PCR products on DNA-templates from the offspring of irradiated and unirradiated male mice revealed an increased variability of microsatellite-associated sequences in the genome of the offspring of the males exposed to 25 and 50 cGy. The DNA-fingerprints of the offspring of male mice exposed to chronic irradiation with the doses 10 and 25 cGy 15 days before fertilization (at the post-meiotic stage of spermatogenesis) showed an increased frequency of "non-parent bands". The results of the study point to the possibility of transmission to the offspring somatic cells of changes increasing genome instability from male parents exposed to chronic low-level radiation prior to fertilization.

  18. Radiation dose reduction at a price: the effectiveness of a male gonadal shield during helical CT scans

    International Nuclear Information System (INIS)

    Dauer, Lawrence T; Casciotta, Kevin A; Erdi, Yusuf E; Rothenberg, Lawrence N

    2007-01-01

    It is estimated that 60 million computed tomography (CT) scans were performed during 2006, with approximately 11% of those performed on children age 0–15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-around male pediatric gonad shield was used during CT scanning. This information is obtained to assist the attending radiologist in the decision to utilize such male gonadal shields in pediatric imaging practice. The dose reduction to the gonads was measured for both direct radiation and for indirect scattered radiation from the abdomen. A 6 cm 3 ion chamber (Model 10X5-6, Radcal Corporation, Monrovia, CA) was placed on a Humanoid real bone pelvic phantom at a position of the male gonads. When exposure measurements with shielding were made, a 1 mm lead wrap-around gonadal shield was placed around the ion chamber sensitive volume. The use of the shields reduced scatter dose to the gonads by a factor of about 2 with no appreciable loss of image quality. The shields reduced the direct beam dose by a factor of about 35 at the expense of extremely poor CT image quality due to severe streak artifacts. Images in the direct exposure case are not useful due to these severe artifacts and the difficulties in positioning these shields on patients in the scatter exposure case may not be warranted by the small absolute reduction in scatter dose unless it is expected that the patient will be subjected to numerous future CT scans

  19. Radiation dose reduction at a price: the effectiveness of a male gonadal shield during helical CT scans.

    Science.gov (United States)

    Dauer, Lawrence T; Casciotta, Kevin A; Erdi, Yusuf E; Rothenberg, Lawrence N

    2007-03-16

    It is estimated that 60 million computed tomography (CT) scans were performed during 2006, with approximately 11% of those performed on children age 0-15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-around male pediatric gonad shield was used during CT scanning. This information is obtained to assist the attending radiologist in the decision to utilize such male gonadal shields in pediatric imaging practice. The dose reduction to the gonads was measured for both direct radiation and for indirect scattered radiation from the abdomen. A 6 cm3 ion chamber (Model 10X5-6, Radcal Corporation, Monrovia, CA) was placed on a Humanoid real bone pelvic phantom at a position of the male gonads. When exposure measurements with shielding were made, a 1 mm lead wrap-around gonadal shield was placed around the ion chamber sensitive volume. The use of the shields reduced scatter dose to the gonads by a factor of about 2 with no appreciable loss of image quality. The shields reduced the direct beam dose by a factor of about 35 at the expense of extremely poor CT image quality due to severe streak artifacts. Images in the direct exposure case are not useful due to these severe artifacts and the difficulties in positioning these shields on patients in the scatter exposure case may not be warranted by the small absolute reduction in scatter dose unless it is expected that the patient will be subjected to numerous future CT scans.

  20. Radiation dose reduction at a price: the effectiveness of a male gonadal shield during helical CT scans

    Directory of Open Access Journals (Sweden)

    Erdi Yusuf E

    2007-03-01

    Full Text Available Abstract Background It is estimated that 60 million computed tomography (CT scans were performed during 2006, with approximately 11% of those performed on children age 0–15 years. Various types of gonadal shielding have been evaluated for reducing exposure to the gonads. The purpose of this study was to quantify the radiation dose reduction to the gonads and its effect on image quality when a wrap-around male pediatric gonad shield was used during CT scanning. This information is obtained to assist the attending radiologist in the decision to utilize such male gonadal shields in pediatric imaging practice. Methods The dose reduction to the gonads was measured for both direct radiation and for indirect scattered radiation from the abdomen. A 6 cm3 ion chamber (Model 10X5-6, Radcal Corporation, Monrovia, CA was placed on a Humanoid real bone pelvic phantom at a position of the male gonads. When exposure measurements with shielding were made, a 1 mm lead wrap-around gonadal shield was placed around the ion chamber sensitive volume. Results The use of the shields reduced scatter dose to the gonads by a factor of about 2 with no appreciable loss of image quality. The shields reduced the direct beam dose by a factor of about 35 at the expense of extremely poor CT image quality due to severe streak artifacts. Conclusion Images in the direct exposure case are not useful due to these severe artifacts and the difficulties in positioning these shields on patients in the scatter exposure case may not be warranted by the small absolute reduction in scatter dose unless it is expected that the patient will be subjected to numerous future CT scans.

  1. Estimation of individual doses from external exposures and dose-group classification of cohort members in high background radiation area in Yangjiang, China

    International Nuclear Information System (INIS)

    Yuan Yongling; Shen Hong; Sun Quanfu; Wei Luxin

    1999-01-01

    Objective: In order to estimate annual effective doses from external exposures in the high background radiation area (HBRA) and in the control area (CA) , the authors measured absorbed dose rates in air from terrestrial gamma radiation with different dosimeters. A dose group classification was an important step for analyzing the dose effects relationship among the cohort members in the investigated areas. The authors used the hamlet specific average annual effective doses of all the 526 hamlets in the investigated areas. A classification of four dose groups was made for the cohort members (high, moderate, low and control) . Methods: For the purpose of studying the dose effect relationships among the cohort members in HBRA and CA, it would be ideal that each subject has his own record of individual accumulated doses received before the evaluation. However, rt is difficult to realize it in practice (each of 106517 persons should wear TLD for a long time) . Thus the authors planned two sets of measurements. Firstly, to measure the environmental dose rates (outdoor, indoor, over the bed) in every hamlet of the investigated area (526 hamlets) , considering the occupancy factors for males and females of different age groups to convert to the annual effective dose from the data of dose rates. Secondly, to measure the individual cumulative dose with TLD for part of the subjects in the investigated areas. Results: Based on the two sets of measurements, the estimates of average annual effective doses in HBRA were 211.86 and 206.75 x 10 -5 Sv/a, respectively, 68.60 and 67.11 x 10 -5 Sv/a, respectively(gamma radiation only) . The intercomparison between these two sets of measurement showed that they were in good correlation. Thus the authors are able to yield the equations of linear regression: Y = 0.9937 + 6.0444, r = 0.9949. Conclusions: The authors took the value obtained from direct measurement as 'standard' , and 15 % for uncertainty of measurement. Since the estimates of

  2. Radiation Parameters of High Dose Rate Iridium -192 Sources

    Science.gov (United States)

    Podgorsak, Matthew B.

    A lack of physical data for high dose rate (HDR) Ir-192 sources has necessitated the use of basic radiation parameters measured with low dose rate (LDR) Ir-192 seeds and ribbons in HDR dosimetry calculations. A rigorous examination of the radiation parameters of several HDR Ir-192 sources has shown that this extension of physical data from LDR to HDR Ir-192 may be inaccurate. Uncertainty in any of the basic radiation parameters used in dosimetry calculations compromises the accuracy of the calculated dose distribution and the subsequent dose delivery. Dose errors of up to 0.3%, 6%, and 2% can result from the use of currently accepted values for the half-life, exposure rate constant, and dose buildup effect, respectively. Since an accuracy of 5% in the delivered dose is essential to prevent severe complications or tumor regrowth, the use of basic physical constants with uncertainties approaching 6% is unacceptable. A systematic evaluation of the pertinent radiation parameters contributes to a reduction in the overall uncertainty in HDR Ir-192 dose delivery. Moreover, the results of the studies described in this thesis contribute significantly to the establishment of standardized numerical values to be used in HDR Ir-192 dosimetry calculations.

  3. Differential sensitivity of long-sleep and short-sleep mice to high doses of cocaine.

    Science.gov (United States)

    de Fiebre, C M; Ruth, J A; Collins, A C

    1989-12-01

    The cocaine sensitivity of male and female long-sleep (LS) and short-sleep (SS) mice, which have been selectively bred for differential ethanol-induced "sleep-time," was examined in a battery of behavioral and physiological tests. Differences between these two mouse lines were subtle and were seen primarily at high doses. At high doses, SS mice were more sensitive than LS mice, particularly to cocaine-induced hypothermia; however, significant hypothermia was not seen except at doses which were very near to the seizure threshold. During a 60-min test of locomotor activity, LS mice showed greater stimulation of Y-maze activity by 20 mg/kg cocaine than SS mice. Consistent with the finding of subtle differences in sensitivity to low doses of cocaine. LS and SS mice did not differ in sensitivity to cocaine inhibition of synaptosomal uptake of [3H]-dopamine, [3H]-norepinephrine or [3H]-5-hydroxytryptamine. However, consistent with the finding of differential sensitivity to high doses of cocaine, SS mice were more sensitive to the seizure-producing effects of the cocaine and lidocaine, a local anesthetic. It is hypothesized that the differential sensitivity of these mouse lines to high doses of cocaine is due to differential sensitivity to cocaine's actions on systems that regulate local anesthetic effects. Selective breeding for differential duration of alcohol-induced "sleep-time" may have resulted in differential ion channel structure or function in these mice.

  4. 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)

  5. Long-Term Impact of Immunosuppressants at Therapeutic Doses on Male Reproductive System in Unilateral Nephrectomized Rats: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Yehui Chen

    2013-01-01

    Full Text Available Cyclosporine, tacrolimus, and sirolimus are commonly used in renal transplant recipients to prevent rejection. However, information for comparative effects of these agents on the male productive system is extremely limited and controversial. In a physiologically and clinically relevant rat model of unilateral nephrectomy, we demonstrated that long-term oral administration of both cyclosporine and sirolimus at doses equivalent to the therapeutic levels used for postrenal transplant patients significantly affects testicular development and the hypothalamic-pituitary-gonadal axis accompanied by profound histological changes of testicular structures on both light and electron microscopic examinations. Spermatogenesis was also severely impaired as indicated by low total sperm counts along with reduction of sperm motility and increase in sperm abnormality after treatment with these agents, which may lead to male infertility. On the other hand, treatment with therapeutic dose of tacrolimus only induced mild reduction of sperm count without histological evidence of testicular injury. The current study clearly demonstrates that commonly used immunosuppressants have various impacts on male reproductive system even at therapeutic levels. Our data provide useful information for the assessment of male infertility in renal transplant recipients who wish to father children. Clinical trials to address these issues should be urged.

  6. Investigation of polymer composite for high dose dosimetry

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  7. Investigation of polymer composite for high dose dosimetry

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-01

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

  8. Establishment of detailed eye model of adult chinese male and dose conversion coefficients calculation under neutron exposure

    International Nuclear Information System (INIS)

    Zhu, Hongyu; Qiu, Rui; Ren, Li; Zhang, Hui; Li, Junli; Wu, Zhen; Li, Chunyan

    2017-01-01

    The human eye lens is sensitive to radiation. ICRP-118 publication recommended a reduction of the occupational annual equivalent dose limit from 150 to 20 mSv, averaged over defined periods of 5 y. Therefore, it is very important to build a detailed eye model for the accurate dose assessment and radiation risk evaluation of eye lens. In this work, a detailed eye model was build based on the characteristic anatomic parameters of the Chinese adult male. This eye model includes seven main structures, which are scleral, choroid, lens, iris, cornea, vitreous body and aqueous humor. The lens was divided into sensitive volume and insensitive volume based on different cell populations. The detailed eye model was incorporated into the converted polygon-mesh version of the Chinese reference adult male whole-body surface model. After the incorporation, dose conversion coefficients for the eye lens were calculated for neutron exposure at AP, PA and LAT geometries with Geant4, the neutron energies were from 0.001 eV to 10 MeV. The calculated lens dose coefficients were compared with those of ICRP-116 publication. Significant differences up to 97.47% were found at PA geometry. This could mainly be attributed to the different geometry characteristic of eye model and parameters of head in different phantom between the present work and ICRP-116 publication. (authors)

  9. ESTABLISHMENT OF DETAILED EYE MODEL OF ADULT CHINESE MALE AND DOSE CONVERSION COEFFICIENTS CALCULATION UNDER NEUTRON EXPOSURE.

    Science.gov (United States)

    Zhu, Hongyu; Qiu, Rui; Wu, Zhen; Ren, Li; Li, Chunyan; Zhang, Hui; Li, Junli

    2017-12-01

    The human eye lens is sensitive to radiation. ICRP-118 publication recommended a reduction of the occupational annual equivalent dose limit from 150 to 20 mSv, averaged over defined periods of 5 y. Therefore, it is very important to build a detailed eye model for the accurate dose assessment and radiation risk evaluation of eye lens. In this work, a detailed eye model was build based on the characteristic anatomic parameters of the Chinese adult male. This eye model includes seven main structures, which are scleral, choroid, lens, iris, cornea, vitreous body and aqueous humor. The lens was divided into sensitive volume and insensitive volume based on different cell populations. The detailed eye model was incorporated into the converted polygon-mesh version of the Chinese reference adult male whole-body surface model. After the incorporation, dose conversion coefficients for the eye lens were calculated for neutron exposure at AP, PA and LAT geometries with Geant4, the neutron energies were from 0.001 eV to 10 MeV. The calculated lens dose coefficients were compared with those of ICRP-116 publication. Significant differences up to 97.47% were found at PA geometry. This could mainly be attributed to the different geometry characteristic of eye model and parameters of head in different phantom between the present work and ICRP-116 publication. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Peripubertal Caffeine Exposure Impairs Longitudinal Bone Growth in Immature Male Rats in a Dose- and Time-Dependent Manner.

    Science.gov (United States)

    Choi, Yun-Young; Choi, Yuri; Kim, Jisook; Choi, Hyeonhae; Shin, Jiwon; Roh, Jaesook

    2016-01-01

    This study investigated the dose- and time-dependent effects of caffeine consumption throughout puberty in peripubertal rats. A total of 85 male SD rats were randomly divided into four groups: control and caffeine-fed groups with 20, 60, or 120 mg/kg/day through oral gavage for 10, 20, 30, or 40 days. Caffeine decreased body weight gain and food consumption in a dose- and time-dependent manner, accompanied by a reduction in muscle and body fat. In addition, it caused a shortening and lightening of leg bones and spinal column. The total height of the growth plate decreased sharply at 40 days in the controls, but not in the caffeine-fed groups, and the height of hypertrophic zone in the caffeine-fed groups was lower than in the control. Caffeine increased the height of the secondary spongiosa, whereas parameters related to bone formation, such as bone area ratio, thickness and number of trabeculae, and bone perimeter, were significantly reduced. Furthermore, serum levels of IGF-1, estradiol, and testosterone were also reduced by the dose of caffeine exposure. Our results demonstrate that caffeine consumption can dose- and time-dependently inhibit longitudinal bone growth in immature male rats, possibly by blocking the physiologic changes in body composition and hormones relevant to bone growth.

  11. High-dose contrast-enhanced MRI in multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-05-01

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

  12. High-dose contrast-enhanced MRI in multiple sclerosis

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  13. Effects of acute sublethal gamma radiation exposure on aggressive behavior in male mice: A dose-response study

    International Nuclear Information System (INIS)

    Maier, D.M.; Landauer, M.R.

    1989-01-01

    The resident-intruder paradigm was used to assess the effects of gamma radiation (0, 3, 5, 7 Gray [Gy] cobalt-60) on aggressive offensive behavior in resident male mice over a 3-month period. The defensive behavior of nonirradiated intruder mice was also monitored. A dose of 3 Gy had no effect on either the residents' offensive behavior or the defensive behavior of the intruders paired with them. Doses of 5 and 7 Gy produced decreases in offensive behavior of irradiated residents during the second week postirradiation. The nonirradiated intruders paired with these animals displayed decreases in defensive behavior during this time period, indicating a sensitivity to changes in the residents' behavior. After the third week postirradiation, offensive and defensive behavior did not differ significantly between irradiated mice and sham-irradiated controls. This study suggests that sublethal doses of radiation can temporarily suppress aggressive behavior but have no apparent permanent effect on that behavior

  14. Low and high dose rate heavy ion radiation-induced intestinal and colonic tumorigenesis in APC1638N/+ mice

    Science.gov (United States)

    Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Fornace, Albert J.; Datta, Kamal

    2017-05-01

    Ionizing radiation (IR) is a recognized risk factor for colorectal cancer (CRC) and astronauts undertaking long duration space missions are expected to receive IR doses in excess of permissible limits with implications for colorectal carcinogenesis. Exposure to IR in outer space occurs at low doses and dose rates, and energetic heavy ions due to their high linear energy transfer (high-LET) characteristics remain a major concern for CRC risk in astronauts. Previously, we have demonstrated that intestinal tumorigenesis in a mouse model (APC1638N/+) of human colorectal cancer was significantly higher after exposure to high dose rate energetic heavy ions relative to low-LET γ radiation. The purpose of the current study was to compare intestinal tumorigenesis in APC1638N/+ mice after exposure to energetic heavy ions at high (50 cGy/min) and relatively low (0.33 cGy/min) dose rate. Male and female mice (6-8 weeks old) were exposed to either 10 or 50 cGy of 28Si (energy: 300 MeV/n; LET: 70 keV/μm) or 56Fe (energy: 1000 MeV/n; LET: 148 keV/μm) ions at NASA Space Radiation Laboratory in Brookhaven National Laboratory. Mice (n = 20 mice/group) were euthanized and intestinal and colon tumor frequency and size were counted 150 days after radiation exposure. Intestinal tumorigenesis in male mice exposed to 56Fe was similar for high and low dose rate exposures. Although male mice showed a decreasing trend at low dose rate relative to high dose rate exposures, the differences in tumor frequency between the two types of exposures were not statistically significant after 28Si radiation. In female mice, intestinal tumor frequency was similar for both radiation type and dose rates tested. In both male and female mice intestinal tumor size was not different after high and low dose rate radiation exposures. Colon tumor frequency in male and female mice after high and low dose rate energetic heavy ions was also not significantly different. In conclusion, intestinal and colonic tumor

  15. Establishment of a dosimetric system for high doses using glasses

    International Nuclear Information System (INIS)

    Correa Quezada, Valeria de la Asuncion

    1997-01-01

    A routine dosimetric system was developed using commercial glass samples. The dosimetric characteristics of national and imported samples were studied: batch uniformity, response repeatability, reutilization, absorbed dose response, detection range, response stability as a function of absorbed dose, storage temperature and thermal treatments pre- and post-irradiation, using the optical absorption technique. As an application, the dosimetric system was tested in a flower irradiation process at IPEN. All the obtained results show the usefulness of the proposed system for high dose dosimetry. (author)

  16. Calibration procedure for thermoluminescent dosemeters in water absorbed doses for Iridium-192 high dose rate sources

    International Nuclear Information System (INIS)

    Reyes Cac, Franky Eduardo

    2004-10-01

    Thermoluminescent dosimeters are used in brachytherapy services quality assurance programs, with the aim of guaranteeing the correct radiation dose supplied to cancer patients, as well as with the purpose of evaluating new clinical procedures. This work describes a methodology for thermoluminescent dosimeters calibration in terms of absorbed dose to water for 192 Ir high dose rate sources. The reference dose used is measured with an ionization chamber previously calibrated for 192 Ir energy quality, applying the methodology proposed by Toelli. This methodology aims to standardizing the procedure, in a similar form to that used for external radiotherapy. The work evolves the adaptation of the TRS-277 Code of the International Atomic Energy Agency, for small and big cavities, through the introduction for non-uniform experimental factor, for the absorbed dose in the neighborhood of small brachytherapy sources. In order to simulate a water medium around the source during the experimental work, an acrylic phantom was used. It guarantees the reproducibility of the ionization chamber and the thermoluminescent dosimeter's location in relation to the radiation source. The values obtained with the ionization chamber and the thermoluminescent dosimeters, exposed to a 192 Ir high dose rate source, were compared and correction factors for different source-detector distances were determined for the thermoluminescent dosimeters. A numeric function was generated relating the correction factors and the source-detector distance. These correction factors are in fact the thermoluminescent dosimeter calibration factors for the 192 Ir source considered. As a possible application of this calibration methodology for thermoluminescent dosimeters, a practical range of source-detector distances is proposed for quality control of 192 Ir high dose rate sources. (author)

  17. Acute and chronic dosing of Lepidium meyenii (Maca) on male rat sexual behavior.

    Science.gov (United States)

    Lentz, Aaron; Gravitt, Karla; Carson, Culley C; Marson, Lesley

    2007-03-01

    The use of natural remedies for the treatment of sexual disorders is under current investigation. For generations people of the rural community in Peru have used Lepidium meyenii Walpers (Maca), because of their belief that it improves fertility and sexual desire. To determine the acute and chronic effects of Maca on male sexual behavior and to examine chronic administration of Maca on anxiety. Ejaculatory and mounting behavior and postejaculatory interval. Anxiety tests using an elevated plus maze, locomotion, and social interaction with another male. Maca (25 and 100 mg/kg) was orally administered to male rats for 30 days. Male sexual behavior was monitored after acute, 7 and 21 days of treatment. Anxiety behavior and locomotion were measured at 28-29 days using the elevated plus maze and social interaction tests. Maca treatment did not produce large changes in male sexual behavior. However, an increase in ejaculation latency and postejaculatory interval was observed after both acute and 7 days of treatment. After 21 days of treatment Maca had no effect on sexual behavior. Chronic administration of Maca did not increase locomotion or anxiety. Acute and short-term administration of Maca produced a small effect of rat male sexual behavior and long-term administration did not increase anxiety.

  18. INFLUENCE OF HIGH CORTISOL DOSES UPON THE SERUM IMMUNOGLOBULIN LEVEL

    OpenAIRE

    Voja Pavlovic; Zoran Pavlovic

    2001-01-01

    The effects of Cortisol upon the serum immunoglobulin concentration areexamined. The experiment involved male guinea pigs of the body weight from 300 to400 g that were nonnally fed and lived under the common laboratory conditions. Theguinea pigs were divided into an experimental and a control group. The experimentalgroup's guinea pigs were given every day (in a 6 days' period) a subcutaneous dose of80 g of corti sol/kg/per day, while the control group ones were given only one ml ofthe physiol...

  19. Assessments for high dose radionuclide therapy treatment planning

    International Nuclear Information System (INIS)

    Fisher, D.R.

    2003-01-01

    Advances in the biotechnology of cell specific targeting of cancer and the increased number of clinical trials involving treatment of cancer patients with radiolabelled antibodies, peptides, and similar delivery vehicles have led to an increase in the number of high dose radionuclide therapy procedures. Optimised radionuclide therapy for cancer treatment is based on the concept of absorbed dose to the dose limiting normal organ or tissue. The limiting normal tissue is often the red marrow, but it may sometimes be the lungs, liver, intestinal tract, or kidneys. Appropriate treatment planning requires assessment of radiation dose to several internal organs and tissues, and usually involves biodistribution studies in the patient using a tracer amount of radionuclide bound to the targeting agent and imaged at sequential timepoints using a planar gamma camera. Time-activity curves are developed from the imaging data for the major organ tissues of concern, for the whole body and sometimes for selected tumours. Patient specific factors often require that dose estimates be customised for each patient. In the United States, the Food and Drug Administration regulates the experimental use of investigational new drugs and requires 'reasonable calculation of radiation absorbed dose to the whole body and to critical organs' using the methods prescribed by the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Review of high dose studies shows that some are conducted with minimal dosimetry, that the marrow dose is difficult to establish and is subject to large uncertainties. Despite the general availability of software, internal dosimetry methods often seem to be inconsistent from one clinical centre to another. (author)

  20. Interaction of 2-Gy Equivalent Dose and Margin Status in Perioperative High-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Martinez-Monge, Rafael; Cambeiro, Mauricio; Moreno, Marta; Gaztanaga, Miren; San Julian, Mikel; Alcalde, Juan; Jurado, Matias

    2011-01-01

    Purpose: To determine patient, tumor, and treatment factors predictive of local control (LC) in a series of patients treated with either perioperative high-dose-rate brachytherapy (PHDRB) alone (Group 1) or with PHDRB combined with external-beam radiotherapy (EBRT) (Group 2). Patient and Methods: Patients (n = 312) enrolled in several PHDRB prospective Phase I-II studies conducted at the Clinica Universidad de Navarra were analyzed. Treatment with PHDRB alone, mainly because of prior irradiation, was used in 126 patients to total doses of 32 Gy/8 b.i.d. or 40 Gy/10 b.i.d. treatments after R0 or R1 resections. Treatment with PHDRB plus EBRT was used in 186 patients to total doses of 16 Gy/4 b.i.d. or 24 Gy/6 b.i.d. treatments after R0 or R1 resections along with 45 Gy of EBRT with or without concomitant chemotherapy. Results: No dose-margin interaction was observed in Group 1 patients. In Group 2 patients there was a significant interaction between margin status and 2-Gy equivalent (Eq2Gy) dose (p = 0.002): (1) patients with negative margins had 9-year LC of 95.7% at Eq2Gy = 62.9Gy; (2) patients with close margins of >1 mm had 9-year LC of 92.4% at Eq2Gy = 72.2Gy, and (3) patients with positive/close <1-mm margins had 9-year LC of 68.0% at Eq2Gy = 72.2Gy. Conclusions: Two-gray equivalent doses ≥70 Gy may compensate the effect of close margins ≥1 mm but do not counterbalance the detrimental effect of unfavorable (positive/close <1 mm) resection margins. No dose-margin interaction is observed in patients treated at lower Eq2Gy doses ≤50 Gy with PHDRB alone.

  1. Calcium carbonate as a possible dosimeter for high irradiation doses

    International Nuclear Information System (INIS)

    Negron M, A.; Ramos B, S.; Camargo R, C.; Uribe, R. M.; Gomez V, V.; Kobayashi, K.

    2014-08-01

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

  2. Calcium carbonate as a possible dosimeter for high irradiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Ramos B, S.; Camargo R, C. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M. [Kent State University, College of Technology, Kent OH (United States); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Kobayashi, K., E-mail: negron@nucleares.unam.mx [Yokohama National University (Japan)

    2014-08-15

    The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

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

    Science.gov (United States)

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

    2011-01-01

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

  4. High-dose buprenorphine: perioperative precautions and management strategies.

    Science.gov (United States)

    Roberts, D M; Meyer-Witting, M

    2005-02-01

    Buprenorphine has been in clinical use in anaesthesia for several decades. Recently, the high-dose sublingual formulation (Subutex, Reckitt Benckiser, Slough, U.K.) has been increasingly used as maintenance therapy in opioid dependence, as an alternative to methadone and other pharmacological therapies. Buprenorphine has unique pharmacological properties making it well suited for use as a maintenance therapy in opioid dependence. However, these same properties may cause difficulty in the perioperative management of pain. Buprenorphine is a partial opioid agonist, attenuating the effects of supplemental illicit or therapeutic opioid agonists. As a result of its high receptor affinity, supplemental opioids do not readily displace buprenorphine from the opioid receptor in standard doses. High-dose buprenorphine has an extended duration of action that prolongs both of these effects. The perioperative management of patients stabilized on high-dose buprenorphine and undergoing surgery requires consideration of the likely analgesic requirements. Where possible the buprenorphine should be continued. Pain management should focus on maximizing non-opioid analgesia, local anaesthesia and non-pharmacological techniques. Where pain may not be adequately relieved by these methods, the addition of a full opioid agonist such as fentanyl or morphine at appropriate doses should be considered, accompanied by close monitoring in a high dependency unit. In situations where this regimen is unlikely to be effective, preoperative conversion to morphine or methadone may be an option. Where available, liaison with a hospital-based alcohol and drug service should always be considered.

  5. Radiobiological modelling of dose-gradient effects in low dose rate, high dose rate and pulsed brachytherapy

    International Nuclear Information System (INIS)

    Armpilia, C; Dale, R G; Sandilos, P; Vlachos, L

    2006-01-01

    This paper presents a generalization of a previously published methodology which quantified the radiobiological consequences of dose-gradient effects in brachytherapy applications. The methodology uses the linear-quadratic (LQ) formulation to identify an equivalent biologically effective dose (BED eq ) which, if applied uniformly to a specified tissue volume, would produce the same net cell survival as that achieved by a given non-uniform brachytherapy application. Multiplying factors (MFs), which enable the equivalent BED for an enclosed volume to be estimated from the BED calculated at the dose reference surface, have been calculated and tabulated for both spherical and cylindrical geometries. The main types of brachytherapy (high dose rate (HDR), low dose rate (LDR) and pulsed (PB)) have been examined for a range of radiobiological parameters/dimensions. Equivalent BEDs are consistently higher than the BEDs calculated at the reference surface by an amount which depends on the treatment prescription (magnitude of the prescribed dose) at the reference point. MFs are closely related to the numerical BED values, irrespective of how the original BED was attained (e.g., via HDR, LDR or PB). Thus, an average MF can be used for a given prescribed BED as it will be largely independent of the assumed radiobiological parameters (radiosensitivity and α/β) and standardized look-up tables may be applicable to all types of brachytherapy treatment. This analysis opens the way to more systematic approaches for correlating physical and biological effects in several types of brachytherapy and for the improved quantitative assessment and ranking of clinical treatments which involve a brachytherapy component

  6. Academic attainment and the high school science experiences among high-achieving African American males

    Science.gov (United States)

    Trice, Rodney Nathaniel

    This study examines the educational experiences of high achieving African American males. More specifically, it analyzes the influences on their successful navigation through high school science. Through a series of interviews, observations, questionnaires, science portfolios, and review of existing data the researcher attempted to obtain a deeper understanding of high achieving African American males and their limitations to academic attainment and high school science experiences. The investigation is limited to ten high achieving African American male science students at Woodcrest High School. Woodcrest is situated at the cross section of a suburban and rural community located in the southeastern section of the United States. Although this investigation involves African American males, all of whom are successful in school, its findings should not be generalized to this nor any other group of students. The research question that guided this study is: What are the limitations to academic attainment and the high school science experiences of high achieving African American males? The student participants expose how suspension and expulsion, special education placement, academic tracking, science instruction, and teacher expectation influence academic achievement. The role parents play, student self-concept, peer relationships, and student learning styles are also analyzed. The anthology of data rendered three overarching themes: (1) unequal access to education, (2) maintenance of unfair educational structures, and (3) authentic characterizations of African American males. Often the policies and practices set in place by school officials aid in creating hurdles to academic achievement. These policies and practices are often formed without meaningful consideration of the unintended consequences that may affect different student populations, particularly the most vulnerable. The findings from this study expose that high achieving African American males face major

  7. Disposition in male volunteers of a subanaesthetic intravenous dose of an oil in water emulsion of 14C-propofol.

    Science.gov (United States)

    Simons, P J; Cockshott, I D; Douglas, E J; Gordon, E A; Hopkins, K; Rowland, M

    1988-04-01

    1. An intravenous dose of 14C-propofol (0.47 mg/kg) administered to six male volunteers was rapidly eliminated with 88% recovered in the urine in 5 days and less than 2% in faeces. 2. The dose was cleared by metabolism with less than 0.3% excreted unchanged. The major metabolites were the glucuronic acid conjugate of propofol and the glucuronic acid and sulphate conjugates of its hydroxylated derivative, 2,6-diisopropyl-1,4-quinol. Propofol glucuronide accounted for about 53% of the urinary radioactivity and was the major metabolite in plasma from 30 min post dose. 3. The blood concentration of propofol declined in a biphasic manner from a maximum mean value of 0.44 microgram/ml, 2 min after injection. The half-lives of the first and second exponential phases, mean values 5 min and 97 min respectively, varied widely among subjects. A proportion of the dose was cleared slowly, probably due to slow release from less well perfused tissues. Propofol accounted for 94% of the total blood radioactivity at 2 min but only about 6% from 3 to 8 h post dose. 4. Propofol has a volume of distribution equivalent to about 3 to 4 times body weight, and a mean total body clearance of 2.2 1/min.

  8. Spectroscopic gamma camera for use in high dose environments

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Yuichiro, E-mail: yuichiro.ueno.bv@hitachi.com [Research and Development Group, Hitachi, Ltd., Hitachi-shi, Ibaraki-ken 319-1221 (Japan); Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi [Research and Development Group, Hitachi, Ltd., Hitachi-shi, Ibaraki-ken 319-1221 (Japan); Fujishima, Yasutake; Kometani, Yutaka [Hitachi Works, Hitachi-GE Nuclear Energy, Ltd., Hitachi-shi, Ibaraki-ken (Japan); Suzuki, Yasuhiko [Measuring Systems Engineering Dept., Hitachi Aloka Medical, Ltd., Ome-shi, Tokyo (Japan); Umegaki, Kikuo [Faculty of Engineering, Hokkaido University, Sapporo-shi, Hokkaido (Japan)

    2016-06-21

    We developed a pinhole gamma camera to measure distributions of radioactive material contaminants and to identify radionuclides in extraordinarily high dose regions (1000 mSv/h). The developed gamma camera is characterized by: (1) tolerance for high dose rate environments; (2) high spatial and spectral resolution for identifying unknown contaminating sources; and (3) good usability for being carried on a robot and remotely controlled. These are achieved by using a compact pixelated detector module with CdTe semiconductors, efficient shielding, and a fine resolution pinhole collimator. The gamma camera weighs less than 100 kg, and its field of view is an 8 m square in the case of a distance of 10 m and its image is divided into 256 (16×16) pixels. From the laboratory test, we found the energy resolution at the 662 keV photopeak was 2.3% FWHM, which is enough to identify the radionuclides. We found that the count rate per background dose rate was 220 cps h/mSv and the maximum count rate was 300 kcps, so the maximum dose rate of the environment where the gamma camera can be operated was calculated as 1400 mSv/h. We investigated the reactor building of Unit 1 at the Fukushima Dai-ichi Nuclear Power Plant using the gamma camera and could identify the unknown contaminating source in the dose rate environment that was as high as 659 mSv/h.

  9. A novel theory of radiation damage at high doses

    International Nuclear Information System (INIS)

    Seeger, A.; Stuttgart Univ.

    1989-01-01

    Deviations of radiation damage (in the case of metals usually monitored by the residual electrical resistivity) from proportionality with the irradiation dose have so far been analysed almost exclusively in terms of extensions of models originally developed for small doses. The present theory considers the opposite limit i.e. the quasi-saturated state. It is argued that at high doses the Lueck-Sizmann effect may result in a self-organization of clusters of vacancies and self-interstitials, forming a heterogeneous froth. Possible structures of this froth and its effect on the electrical resistivity of metals are discussed. The model is shown to account for the dependence of the ''saturation resistivity'' on the nature of the irradiation as well as for several other hitherto poorly explained observations. Among them are the electrical-resistivity variation induced by high-dose irradiation with heavy ions, the amorphization of certain alloys by high-dose electron irradiation, and the occurrence of ordered arrays of stacking-fault tetrahedra after in-situ irradiations in high-voltage electron microscopes. (author)

  10. Radiation shielding and dose rate distribution for the building of the high dose rate accelerator

    International Nuclear Information System (INIS)

    Matsuda, Koji; Takagaki, Torao; Nakase, Yoshiaki; Nakai, Yohta.

    1984-03-01

    A high dose rate electron accelerator was established at Osaka Laboratory for Radiation Chemistry, Takasaki Establishment, JAERI in the fiscal year of 1975. This report shows the fundamental concept for the radiation shielding of the accelerator building and the results of their calculations which were evaluated through the model experiments. After the construction of the building, the leak radiation was measured in order to evaluate the calculating method of radiation shielding. Dose rate distribution of X-rays was also measured in the whole area of the irradiation room as a data base. (author)

  11. Effective dose calculation in CT using high sensitivity TLDs

    International Nuclear Information System (INIS)

    Brady, Z.; Johnston, P.N.

    2010-01-01

    Full text: To determine the effective dose for common paediatric CT examinations using thermoluminescence dosimetry (TLD) mea surements. High sensitivity TLD chips (LiF:Mg,Cu,P, TLD-IOOH, Thermo Fisher Scientific, Waltham, MA) were calibrated on a linac at an energy of 6 MY. A calibration was also performed on a superricial X-ray unit at a kilovoltage energy to validate the megavoltage cali bration for the purpose of measuring doses in the diagnostic energy range. The dose variation across large organs was assessed and a methodology for TLD placement in a 10 year old anthropomorphic phantom developed. Effective dose was calculated from the TLD measured absorbed doses for typical CT examinations after correcting for the TLD energy response and taking into account differences in the mass energy absorption coefficients for different tissues and organs. Results Using new tissue weighting factors recommended in ICRP Publication 103, the effective dose for a CT brain examination on a 10 year old was 1.6 millisieverts (mSv), 4.9 mSv for a CT chest exa ination and 4.7 mSv for a CT abdomen/pelvis examination. These values are lower for the CT brain examination, higher for the CT chest examination and approximately the same for the CT abdomen/ pelvis examination when compared with effective doses calculated using ICRP Publication 60 tissue weighting factors. Conclusions High sensitivity TLDs calibrated with a radiotherapy linac are useful for measuring dose in the diagnostic energy range and overcome limitations of output reproducibility and uniformity asso ciated with traditional TLD calibration on CT scanners or beam quality matched diagnostic X-ray units.

  12. Implementation of high-dose chemical dosimetry for industrial facilities

    International Nuclear Information System (INIS)

    Conceicao, Cirilo Cezar Sant'Anna da

    2006-01-01

    The purpose of this work is the implementation of methodology for high dose measurements using chemical dosimeters in liquid phase, traceable to the international metrology system, and make available in the country, the standard of high-dose to industrial irradiation facilities and research irradiators, trough the quality program with comparative measurements and direct use of the standard dosimeters in routine. The use of these low cost dosimetry systems in industrial irradiation facilities, assists to the certification requirements and it can reduce the costs with dosimetry for approximately 20% of the total dosimetry costs, using these systems in routine measurements and validation process, largely substituting the imported PMMA dosimeters, among others. (author)

  13. Characterization of Thymol blue Radiochromic dosimeters for high dose applications

    Directory of Open Access Journals (Sweden)

    Feras M. Aldweri

    2018-03-01

    Full Text Available Thymol blue (TB solutions and Thymol blue Polyvinyl Alcohol (TB-PVA films have been introduced as Radiochromic dosimeter for high dose applications. The dosimeters were irradiated with gamma ray (60Co source from 5 to 30 kGy for film, and from 0.150 kGy to 4 kGy for solution. The optical density of unirradiated and irradiated TB solution as well as TB-PVA film dosimeters were studied in terms of absorbance at 434 nm using UV/VIS spectrophotometer. The effects of scan temperature, light pre-gamma irradiation, dose rate, relative humidity and stability of the absorbance of solutions and films after irradiation were investigated. We found the dose sensitivity of TB solution and TB-PVA film dosimeters increases significantly with increases of the absorbed dose as well as with the increases of TB dye concentrations. The useful dose range of developed TB solutions and TB-PVA films dosimeters is in the range 0.125–1 kGy and of 5–20 kGy, respectively. Keywords: Dose sensitivity, Radio-chromic dosimeter, Thymol blue, Absorbance, Concentrations

  14. Micro- and Macrosystem Predictors of High School Male Suicidal Behaviors

    Science.gov (United States)

    Beck-Cross, Cathy; Cooper, Robyn

    2015-01-01

    Suicide is the third leading cause of death among young people ages 15 to 19 years, with male adolescents four times more likely to die than their female peers. This study used Bronfenbrenner's bioecological model to examine micro- and macrosystems as predictors of suicidal behaviors through responses by male adolescents (N = 9,910) to a statewide…

  15. BH3105 type neutron dose equivalent meter of high sensitivity

    International Nuclear Information System (INIS)

    Ji Changsong; Zhang Enshan; Yang Jianfeng; Zhang Hong; Huang Jiling

    1995-10-01

    It is noted that to design a neutron dose meter of high sensitivity is almost impossible in the frame of traditional designing principle--'absorption net principle'. Based on a newly proposed principle of obtaining neutron dose equi-biological effect adjustment--' absorption stick principle', a brand-new neutron dose-equivalent meter with high neutron sensitivity BH3105 has been developed. Its sensitivity reaches 10 cps/(μSv·h -1 ), which is 18∼40 times higher than one of foreign products of the same kind and is 10 4 times higher than that of domestic FJ342 neutron rem-meter. BH3105 has a measurement range from 0.1μSv/h to 1 Sv/h which is 1 or 2 orders wider than that of the other's. It has the advanced properties of gamma-resistance, energy response, orientation, etc. (6 tabs., 5 figs.)

  16. Safety and tolerability of high doses of glucocorticoides

    Directory of Open Access Journals (Sweden)

    Rakić Branislava D.

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  18. HIGH-DOSE RATE BRACHYTHERAPY IN CARCINOMA CERVIX STAGE IIIB

    Directory of Open Access Journals (Sweden)

    Sathya Maruthavanan

    2016-07-01

    Full Text Available INTRODUCTION Radiotherapy is the standard treatment in locally advanced (IIB-IVA and early inoperable cases. The current standard of practice with curable intent is concurrent chemoradiation in which intracavitary brachytherapy is an integral component of radiotherapy. This study aims at assessing the efficacy of HDR ICBT (High-dose rate intracavitary brachytherapy in terms local response, normal tissue reactions, and feasibility. METHODS AND MATERIALS A total of 20 patients of stage IIIB cancer of the uterine cervix were enrolled in the study and were planned to receive concurrent chemotherapy weekly along with EBRT (external beam radiotherapy to a dose of 50 Gy/25 Fr. Suitability for ICBT was assessed at 40 Gy/20 Fr. 6/20 patients were suitable at 40 Gy and received HDR ICBT with a dose of 5.5 Gy to point A in 4 sessions (5.5 Gy/4 Fr. The remaining 14/20 patients completed 50 Gy and received HDR ICBT with a dose of 6 Gy to point A in 3 sessions (6 Gy/3 Fr. RESULTS A total of 66 intracavitary applications were done and only one application required dose modification due to high bladder dose, the pelvic control rate was 85% (17/20. 10% (2/20 had stable disease and 5% (1/20 had progressive disease at one year of follow up. When toxicity was considered only 15% developed grade I and grade II rectal complications. Patient compliance and acceptability was 100%. Patients were very comfortable with the short treatment time as compared with patients on LDR ICBT (low-dose rate intracavitary brachytherapy treatment interviewed during the same period. CONCLUSION This study proves that HDR brachytherapy is efficacious and feasible in carcinoma of cervix stage IIIB. It also proves that good dose distribution can be achieved with HDR intracavitary facility by the use of dose optimization. The short treatment time in HDR ICBT makes it possible to maintain this optimised dose distribution throughout the treatment providing a gain in the therapeutic ratio and

  19. The influence of high doses of radiation in citrine stones

    International Nuclear Information System (INIS)

    Teixeira, M. I.; Caldas, L. V. E.

    2014-08-01

    The possibility of using samples of Brazilian stones as quartz, amethyst, topaz, jasper, etc. for high-dose dosimetry has been studied in recent years at IPEN, using the techniques of optical absorption (Oa), thermoluminescent (Tl), optically stimulated luminescence (OSL) and resonance paramagnetic electron (EPR). In this work, the Tl properties of citrine samples were studied. They were exposed to different doses of gamma radiation ( 60 Co). The natural citrine stone was extracted from a mine in Minas Gerais state, Brazil; it is a tecto silicate ranked as one of three-dimensional structure, showing clear yellow to golden brown color. The natural citrine stone is classified as quartz (SiO 2 ), and it has a lower symmetry and more compact reticulum. The Tl emission curve showed two peaks at 160 grades C and 220 grades C. To remove the Tl peak (160 grades C) of the sintered citrine pellet glow curves, different thermal treatments were tested during several time intervals. The Tl dose-response curve between 50 Gy and 100 kGy, the reproducibility of Tl response and the lower detection dose were obtained. The results show that citrine may be useful as high-dose detectors. (Author)

  20. TL response of citrine samples for high-dose dosimetry

    International Nuclear Information System (INIS)

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

    2011-01-01

    The possibility of using samples of Brazilian stones as quartz, amethyst, topaz, etc. for high-dose dosimetry has been studied in recent years at IPEN, using the thermoluminescence technique (TL). In this work, the TL properties of citrine samples were studied. They were exposed to different doses of gamma radiation ( 60 Co). The natural citrine stone was extracted from a mine in Minas Gerais state, Brazil; it is a tectosilicate ranked as one of three-dimensional structure, showing clear yellow to golden brown color. The natural citrine stone is classified as quartz (SiO 2 ), and it has a lower symmetry and more compact reticulum. The citrine stone samples were powdered, and the selected grains were mixed with Teflon in the proportion 2 (Teflon):1 (Citrine). The mixture was pressed and sintered for production of Citrine -Teflon pellets of 50 mg. The TL emission curve showed two peaks at 160 deg C and 220 deg C. To remove the TL peak (160 deg C) of the sintered citrine pellet glow curves, different thermal treatments were tested during several time intervals. The TL dose-response curve between 50 Gy and 100 kGy, the reproducibility of TL response and the lower detection dose were obtained. The preliminary results show that citrine may be useful for high-dose dosimetry. (author)

  1. Multifocal Electroretinography after High Dose Chloroquine Therapy for Malaria

    Directory of Open Access Journals (Sweden)

    Aline Correa de Carvalho

    2013-01-01

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

  2. The influence of high doses of radiation in citrine stones

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, M. I. [Universidade Nove de Julho - UNINOVE, Rua Vergueiro 235/249, 01504-001 Sao Paulo (Brazil); Caldas, L. V. E., E-mail: miteixeira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    The possibility of using samples of Brazilian stones as quartz, amethyst, topaz, jasper, etc. for high-dose dosimetry has been studied in recent years at IPEN, using the techniques of optical absorption (Oa), thermoluminescent (Tl), optically stimulated luminescence (OSL) and resonance paramagnetic electron (EPR). In this work, the Tl properties of citrine samples were studied. They were exposed to different doses of gamma radiation ({sup 60}Co). The natural citrine stone was extracted from a mine in Minas Gerais state, Brazil; it is a tecto silicate ranked as one of three-dimensional structure, showing clear yellow to golden brown color. The natural citrine stone is classified as quartz (SiO{sub 2}), and it has a lower symmetry and more compact reticulum. The Tl emission curve showed two peaks at 160 grades C and 220 grades C. To remove the Tl peak (160 grades C) of the sintered citrine pellet glow curves, different thermal treatments were tested during several time intervals. The Tl dose-response curve between 50 Gy and 100 kGy, the reproducibility of Tl response and the lower detection dose were obtained. The results show that citrine may be useful as high-dose detectors. (Author)

  3. The Effects of Pretreatment with Various Doses of L-Arginine on Cisplatin-Induced Nephropathy of Male Rats

    Directory of Open Access Journals (Sweden)

    B Rasoulian

    2016-09-01

    Full Text Available Introduction: Cisplatin is a widely used anti-cancer drug, which its application is limited by nephrotoxicity. In this study, the effect of pretreatment with different l-arginine doses on Cisplatin-induced renal functional injury was investigated. Methods: 63 male rats were divided into 7 groups: In groups 3, 4, 5 and 6, 60 min before the Cisplatin injection (5mg/kg; L-Arginine with doses of 50,100,200 or 400mg/kg was injected, respectively. In group7, normal saline was injected before Cisplatin administration. In groups 1 and 2, normal saline was injected instead of Cisplatin. In group 2, 60min before normal saline injection, 400mg/kg L-Arginine was administered and in group1, instead of L-arginine, normal saline was injected too. Injections were intraperitoneal. 72h after Cisplatin injection, blood sampling and plasma separation were done. Urine sample was collected 24 hours before blood sampling by metabolic cage. The mean of plasma urea and creatinine levels and creatinine clearance (ml/day.kg and fractional excretion of Na (FENa, % were compared among different groups as renal functional parameters. Results: In comparison to group 7, L-arginine injection in a dose of 400mg/kg led to significant amelioration of all parameters. 200 mg/kg L-arginine administration led to significant decrease in plasma urea level and FENa. 100mg/kg L-arginine caused significant improvement in fractional excretion of sodium. L-arginine injection with 50mg/kg dose, significantly ameliorate all renal function tests instead of creatinine clearance. Conclusion: Pretreatment with L-arginine administration with 400 or 50 mg/kg doses, respectively, had the highest effect on reducing Cisplatin-induced nephropathy. L-arginine injection with intermediate doses i.e. 200 or 100 mg/kg had less effect in reducing Cisplatin-induced nephropathy and it needs more investigations.

  4. Use of glasses as radiation detectors for high doses

    International Nuclear Information System (INIS)

    Caldas, L.

    1989-08-01

    Glass samples were tested in relation to the possibility of use in high dose dosimetry in medical and industrial areas. The main characteristics were determined: detection threshold, reproducibility, response to gamma radiation of 137 Cs and 6 Co and thermal decay at ambient temperature, with the use of optical absorption and thermoluminesce techniques. (author) [pt

  5. Oval pulsed high-dose dexamethasone for myositis

    NARCIS (Netherlands)

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

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

  6. Oral pulsed high-dose dexamethasone for myositis

    NARCIS (Netherlands)

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

    2000-01-01

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

  7. High-dose acetylcysteine in idiopathic pulmonary fibrosis

    NARCIS (Netherlands)

    Demedts, Maurits; Behr, Juergen; Buhl, Roland; Costabel, Ulrich; Dekhuijzen, Richard; Jansen, Henk M.; MacNee, William; Thomeer, Michiel; Wallaert, Benoit; Laurent, François; Nicholson, Andrew G.; Verbeken, Eric K.; Verschakelen, Johny; Flower, Christopher D. R.; Capron, Frédérique; Petruzzelli, Stefano; de Vuyst, Paul; van den Bosch, Jules M. M.; Rodriguez-Becerra, Eulogio; Corvasce, Giuseppina; Lankhorst, Ida; Sardina, Marco; Montanari, Mauro

    2005-01-01

    BACKGROUND Idiopathic pulmonary fibrosis is a chronic progressive disorder with a poor prognosis. METHODS We conducted a double-blind, randomized, placebo-controlled multicenter study that assessed the effectiveness over one year of a high oral dose of acetylcysteine (600 mg three times daily) added

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

    NARCIS (Netherlands)

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

    2005-01-01

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

  9. Unusual complication and successful high-dose chemotherapy ...

    African Journals Online (AJOL)

    ... treated with high-dose chemotherapy in our institution, complicated by unusual bilateral renal vein tumour thrombi and tumour lysis syndrome. We believe this unique case highlights the need for early recognition of current and potential complications on staging computed tomography imaging, as well as successful use of ...

  10. The effects of high dose and highly fractionated radiation on distraction osteogenesis in the murine mandible

    International Nuclear Information System (INIS)

    Monson, Laura A; Cavaliere, Christi M; Deshpande, Sagar S; Ayzengart, Alexander L; Buchman, Steven R

    2012-01-01

    The ability of irradiated tissue to support bony growth remains poorly defined, although there are anecdotal cases reported showing mixed results for the use of mandibular distraction osteogenesis after radiation for head and neck cancer. Many of these reports lack objective measures that would allow adequate analysis of outcomes or efficacy. The purpose of this experiment was to utilize a rat model of mandibular distraction osteogenesis after high dose and highly fractionated radiation therapy and to evaluate and quantify distracted bone formation under these conditions. Male Sprague–Dawley rats underwent 12 fractions of external beam radiation (48 Gray) of the left mandible. Following a two week recovery period, an external frame distractor was applied and gradual distraction of the mandible was performed. Tissue was harvested after a twenty-eight day consolidation period. Gross, radiologic and histological evaluations were undertaken. Those animals subjected to pre-operative radiation showed severe attenuation of bone formation including bone atrophy, incomplete bridging of the distraction gap, and gross bony defects or non-union. Although physical lengthening was achieved, the irradiated bone consistently demonstrated marked damaging effects on the normal process of distraction osteogenesis. This murine model has provided reliable evidence of the injurious effects of high dose radiation on bone repair and regeneration in distraction osteogenesis utilizing accurate and reproducible metrics. These results can now be used to assist in the development of therapies directed at mitigating the adverse consequences of radiation on the regeneration of bone and to optimize distraction osteogenesis so it can be successfully applied to post-oncologic reconstruction

  11. A clinical comparison of high dose and low dose of Suxamethonium

    Directory of Open Access Journals (Sweden)

    RK Yadav

    2014-01-01

    Full Text Available Background: Suxamethonium having its rapid onset and short duration of action makes this drug unique amongst the neuromuscular blocking drugs described so far. However, use of suxamethonium is associated with a large number of undesirable side effects. Objective: To evaluate clinical effects of high and low dose of suxamethonium and to determine whether lower dose of suxamethonium can be used for any beneficial effects in terms of its various adverse effects e.g. cardiovascular responses, post-operative muscle pains and intraocular pressure. Methods: A total of 100 patients were included in this prospective study. All these patients on preoperative clinical evaluation were assessed to have adequate airway. All the patients were divided in two groups, low dose group (group I and High dose group (group II with 50 patients in each at random. A standard anesthetic technique was adhered to all the patients and following parameters were observed on comparative basis: a. Fasciculation and post operative myalgia. b. Cardiovascular effects, c. Intraocular pressure. Observation: The incidence of post Suxamethonium pain was significantly greater in group II. Increase in heart rate from baseline was significant in both groups. There was no significant difference between the two groups in the diastolic pressure but rise in systolic blood pressure was significant at all assessment times in both groups. This rise from control was statistically significant. Conclusion: Suxamethonium can be used in lower doses (0.5 mg/kg in elective cases without airway compromise. It gives benefits of reduced muscle pains, cardiovascular responses and intraocular hypertension. Journal of College of Medical Sciences-Nepal, 2013, Vol-9, No-2, 1-8 DOI: http://dx.doi.org/10.3126/jcmsn.v9i2.9677

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

    Directory of Open Access Journals (Sweden)

    Y. Sobita Devi

    2011-12-01

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

  13. Radiation processing and high-dose dosimetry at ANSTO

    International Nuclear Information System (INIS)

    Gant, G.J.; Saunders, M.; Banos, C.; Mo, L.; Davies, J.; Evans, O.

    2001-01-01

    The Radiation Technology group at ANSTO is part of the Physics Division and provides services and advice in the areas of gamma irradiation and high-dose dosimetry. ANSTO's irradiation facilities are designed for maximum dose uniformity and provide a precision irradiation service unique in Australia. Radiation Technology makes and sells reference and transfer standard dosimeters which are purchased by users and suppliers of commercial irradiation services in Australia and the Asia-Pacific region. A calibration service is also provided for dosimeters purchased from other suppliers

  14. Australian high-dose-rate brachytherapy protocols for gynaecological malignancy

    International Nuclear Information System (INIS)

    MacLeod, C.; Dally, M.; Stevens, M.; Thornton, D.; Carruthers, S.; Jeal, P.

    2001-01-01

    There is no consensus over the optimal dose fractionation schedules for high-dose-rate (HDR) brachytherapy used for gynaecological malignancy. In Australian public hospital departments of radiation oncology, HDR brachytherapy for gynaecological cancer is being more commonly used. A survey of public departments that are using this technology, or that plan to introduce this technology, was performed. Their current protocols are presented. In general, protocols are similar biologically; however, the practical aspects such as the number of fractions given do vary and may reflect resource restrictions or, alternatively, differences in interpretations of the literature and of the best protocols by clinicians. Copyright (2001) Blackwell Science Pty Ltd

  15. Tolerance of the Brachial Plexus to High-Dose Reirradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Allen M., E-mail: achen5@kumc.edu; Yoshizaki, Taeko; Velez, Maria A.; Mikaeilian, Argin G.; Hsu, Sophia; Cao, Minsong

    2017-05-01

    Purpose: To study the tolerance of the brachial plexus to high doses of radiation exceeding historically accepted limits by analyzing human subjects treated with reirradiation for recurrent tumors of the head and neck. Methods and Materials: Data from 43 patients who were confirmed to have received overlapping dose to the brachial plexus after review of radiation treatment plans from the initial and reirradiation courses were used to model the tolerance of this normal tissue structure. A standardized instrument for symptoms of neuropathy believed to be related to brachial plexus injury was utilized to screen for toxicity. Cumulative dose was calculated by fusing the initial dose distributions onto the reirradiation plan, thereby creating a composite plan via deformable image registration. The median elapsed time from the initial course of radiation therapy to reirradiation was 24 months (range, 3-144 months). Results: The dominant complaints among patients with symptoms were ipsilateral pain (54%), numbness/tingling (31%), and motor weakness and/or difficulty with manual dexterity (15%). The cumulative maximum dose (Dmax) received by the brachial plexus ranged from 60.5 Gy to 150.1 Gy (median, 95.0 Gy). The cumulative mean (Dmean) dose ranged from 20.2 Gy to 111.5 Gy (median, 63.8 Gy). The 1-year freedom from brachial plexus–related neuropathy was 67% and 86% for subjects with a cumulative Dmax greater than and less than 95.0 Gy, respectively (P=.05). The 1-year complication-free rate was 66% and 87%, for those reirradiated within and after 2 years from the initial course, respectively (P=.06). Conclusion: The development of brachial plexus–related symptoms was less than expected owing to repair kinetics and to the relatively short survival of the subject population. Time-dose factors were demonstrated to be predictive of complications.

  16. Precision, high dose radiotherapy: helium ion treatment of uveal melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, W.M.; Char, D.H.; Quivey, J.M.; Castro, J.R.; Chen, G.T.Y.; Collier, J.M.; Cartigny, A.; Blakely, E.A.; Lyman, J.T.; Zink, S.R.

    1985-02-01

    The authors report on 75 patients with uveal melanoma who were treated by placing the Bragg peak of a helium ion beam over the tumor volume. The technique localizes the high dose region very tightly around the tumor volume. This allows critical structures, such as the optic disc and the macula, to be excluded from the high dose region as long as they are 3 to 4 mm away from the edge of the tumor. Careful attention to tumor localization, treatment planning, patient immobilization and treatment verification is required. With a mean follow-up of 22 months (3 to 60 months) the authors have had only five patients with a local recurrence, all of whom were salvaged with another treatment. Pretreatment visual acuity has generally been preserved as long as the tumor edge is at least 4 mm away from the macula and optic disc. The only serious complication to date has been an 18% incidence of neovascular glaucoma in the patients treated at our highest dose level. Clinical results and details of the technique are presented to illustrate potential clinical precision in administering high dose radiotherapy with charged particles such as helium ions or protons.

  17. Precision, high dose radiotherapy: helium ion treatment of uveal melanoma

    International Nuclear Information System (INIS)

    Saunders, W.M.; Char, D.H.; Quivey, J.M.

    1985-01-01

    The authors report on 75 patients with uveal melanoma who were treated by placing the Bragg peak of a helium ion beam over the tumor volume. The technique localizes the high dose region very tightly around the tumor volume. This allows critical structures, such as the optic disc and the macula, to be excluded from the high dose region as long as they are 3 to 4 mm away from the edge of the tumor. Careful attention to tumor localization, treatment planning, patient immobilization and treatment verification is required. With a mean follow-up of 22 months (3 to 60 months) the authors have had only five patients with a local recurrence, all of whom were salvaged with another treatment. Pretreatment visual acuity has generally been preserved as long as the tumor edge is at least 4 mm away from the macula and optic disc. The only serious complication to date has been an 18% incidence of neovascular glaucoma in the patients treated at our highest dose level. Clinical results and details of the technique are presented to illustrate potential clinical precision in administering high dose radiotherapy with charged particles such as helium ions or protons

  18. Dimethyl sulfoxyde diethyl fumarate solution for high dose dosimetry

    International Nuclear Information System (INIS)

    Al-Kassiri, H.; Kattan, M.; Daher, Y.

    2007-06-01

    Dosimetric characterization of diethyl fumarate DEF in dimethyl sulfoxyde DMSO solution has been studied spectrophotometrically for possible application at high dose radiation dosimetry in the range (0-225 kGy). The absorption spectra of irradiated solution showed broad absorption bands between (325-400 nm) with a shoulder at 332 nm. The absorption increases as the dose is increased. Absorbance at 332 nm were measured and plotted against absorbed dose. Linear relationship and good response were found between absorbed dose and absorbance of 20% DEF concentration in the range (0-225 kGy) at the wave length, and linearity up to 250 kGy of absorbance at 332 nm .Good dose rate independence was observed in the range (14-33 kGy/h). The effect of post irradiation storage in darkness and indirect daylight conditions were not found to influence the absorption up to 700 h after irradiation. The effect of irradiation temperature within the range (0 to 60 centigrade degree) on the dosimetry performance was discussed.(author)

  19. Male gonadal dose of ionizing radiation delivered during X-ray examinations and monthly probability of pregnancy: a population-based retrospective study

    Directory of Open Access Journals (Sweden)

    Slama Remy

    2006-03-01

    Full Text Available Abstract Background Male gonadal exposure to ionizing radiation may disrupt spermatogenesis, but its influence on the fecundity of couples has been rarely studied. We aimed to characterize the influence of male gonadal dose of ionizing radiation delivered during radiodiagnostic on the monthly probability of pregnancy. Methods We recruited a random sample of women who retrospectively described 1110 periods of unprotected intercourse beginning between 1985 and 1999 and leading either to a live birth or to no pregnancy; their duration was censored after 13 months. The male partner answered a telephone questionnaire on radiodiagnostic examinations. We assigned a mean gonadal dose to each type of radiodiagnostic examination. We defined male dose for each period of unprotected intercourse as the sum of the gonadal doses of the X-ray examinations experienced between 18 years of age and the date of discontinuation of contraception. Time to pregnancy was analysed using a discrete Cox model with random effect allowing to estimate hazard ratios of pregnancy. Results After adjustment for female factors likely to influence fecundity, there was no evidence of an association between male dose and the probability of pregnancy (test of homogeneity, p = 0.55. When compared to couples with a male gonadal dose between 0.01 and 0.20 milligrays (n = 321 periods of unprotected intercourse, couples with a gonadal dose above 10 milligrays had a hazard ratio of pregnancy of 1.44 (95% confidence interval, 0.73–2.86, n = 31. Conclusion Our study provides no evidence of a long-term detrimental effect of male gonadal dose of ionizing radiation delivered during radiodiagnostic on the monthly probability of pregnancy during the year following discontinuation of contraceptive use. Classification errors due to the retrospective assessment of male gonadal exposure may have limited the statistical power of our study.

  20. Pulsed dose rate and fractionated high dose rate brachytherapy: choice of brachytherapy schedules to replace low dose rate treatments

    International Nuclear Information System (INIS)

    Visser, Andries G.; Aardweg, Gerard J.M.J. van den; Levendag, Peter C.

    1996-01-01

    Purpose: Pulsed dose rate (PDR) brachytherapy is a new type of afterloading brachytherapy (BT) in which a continuous low dose rate (LDR) treatment is simulated by a series of 'pulses,' i.e., fractions of short duration (less than 0.5 h) with intervals between fractions of 1 to a few hours. At the Dr. Daniel den Hoed Cancer Center, the term 'PDR brachytherapy' is used for treatment schedules with a large number of fractions (at least four per day), while the term 'fractionated high dose rate (HDR) brachytherapy' is used for treatment schedules with just one or two brachytherapy fractions per day. Both treatments can be applied as alternatives for LDR BT. This article deals with the choice between PDR and fractionated HDR schedules and proposes possible fractionation schedules. Methods and Materials: To calculate HDR and PDR fractionation schedules with the intention of being equivalent to LDR BT, the linear-quadratic (LQ) model has been used in an incomplete repair formulation as given by Brenner and Hall, and by Thames. In contrast to earlier applications of this model, both the total physical dose and the overall time were not kept identical for LDR and HDR/PDR schedules. A range of possible PDR treatment schedules is presented, both for booster applications (in combination with external radiotherapy (ERT) and for BT applications as a single treatment. Because the knowledge of both α/β values and the half time for repair of sublethal damage (T (1(2)) ), which are required for these calculations, is quite limited, calculations regarding the equivalence of LDR and PDR treatments have been performed for a wide range of values of α/β and T (1(2)) . The results are presented graphically as PDR/LDR dose ratios and as ratios of the PDR/LDR tumor control probabilities. Results: If the condition that total physical dose and overall time of a PDR treatment must be exactly identical to the values for the corresponding LDR treatment regimen is not applied, there appears

  1. High dose rate versus low dose rate interstitial radiotherapy for carcinoma of the floor of mouth

    International Nuclear Information System (INIS)

    Inoue, Takehiro; Inoue, Toshihiko; Yamazaki, Hideya; Koizumi, Masahiko; Kagawa, Kazufumi; Yoshida, Ken; Shiomi, Hiroya; Imai, Atsushi; Shimizutani, Kimishige; Tanaka, Eichii; Nose, Takayuki; Teshima, Teruki; Furukawa, Souhei; Fuchihata, Hajime

    1998-01-01

    Purpose: Patients with cancer of the floor of mouth are treated with radiation because of functional and cosmetic reasons. We evaluate the treatment results of high dose rate (HDR) and low dose rate (LDR) interstitial radiation for cancer of the floor of mouth. Methods and Materials: From January 1980 through March 1996, 41 patients with cancer of the floor of mouth were treated with LDR interstitial radiation using 198 Au grains, and from April 1992 through March 1996 16 patients with HDR interstitial radiation. There were 26 T1 tumors, 30 T2 tumors, and 1 T3 tumor. For 21 patients treated with interstitial radiation alone, a total radiation dose of interstitial therapy was 60 Gy/10 fractions/6-7 days in HDR and 85 Gy within 1 week in LDR. For 36 patients treated with a combination therapy, a total dose of 30 to 40 Gy of external radiation and a total dose of 48 Gy/8 fractions/5-6 days in HDR or 65 Gy within 1 week in LDR were delivered. Results: Two- and 5-year local control rates of patients treated with HDR interstitial radiation were 94% and 94%, and those with LDR were 75% and 69%, respectively. Local control rate of patients treated with HDR brachytherapy was slightly higher than that with 198 Au grains (p = 0.113). For late complication, bone exposure or ulcer occurred in 6 of 16 (38%) patients treated with HDR and 13 of 41 (32%) patients treated with LDR. Conclusion: HDR fractionated interstitial brachytherapy can be an alternative to LDR brachytherapy for cancer of the floor of mouth and eliminate radiation exposure for the medical staff

  2. Brachytherapy for early oral tongue cancer. Low dose rate to high dose rate

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Inoue, Toshihiko; Furukawa, Souhei; Kakimoto, Naoya

    2003-01-01

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n=341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer. (author)

  3. High dose calibrations at the Pacific Northwest Laboratory

    International Nuclear Information System (INIS)

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

    1988-10-01

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

  4. The possible role of low doses of Cerastes cerastes crude venom in mitigating doxorubicin induced oxidative damage in male rats

    International Nuclear Information System (INIS)

    Salama, S. F.; AL-Sadoon, M. K.

    2012-01-01

    The purpose of this study was to investigate the possible role of Cerastes cerastes crude venom (CCV) in attenuating (doxorubicin) DOX oxidative damage in male rats. Forty male rats, matched in age and weight were sorted into four groups, control, CCV-group, DOX-group and CCV + DOX-groups. DOX given as a single dose i.p. injection of 10 mg per kg body weight) induced a significant increase in serum advanced oxidation protein products (AOPP), malondialdehyde (MDA), urea, total proteins, AST, ALT, triglycerides and cholesterol. Meanwhile significant decrease in reduced glutathione (GSH), superoxide dimutase (SOD),uric acid as well as RBCs, platelet counts, hemoglobin content (Hb), haematocrit value (Hct), total leukocytes, neutrophils and lymphocytes count was recorded after 14 days. CCV i.p. injected daily at a dose of . LD50 for 14 days showed a significant decrease of the content of serum AOPP and MDA, lymphocytes and a significant increase of GSH, uric acid, RBCs count, Hb, Hct, total proteins, triglycerides, neutrophils count compared to control. In DOX+ CCV-group, CCV was given daily for 7 days before DOX, 10 mg/kg, followed by CCV for 7 more days, a significant inhibition of the serum triglycerides, cholesterol, urea and total protein, AST, ALT, AOPP, MDA, and a significant elevation of GSH, SOD, uric acid, RBCs, platelet counts, Hb, Hct, were shown as compared with DOX- group. It could be concluded that CCV at low doses can be used as a natural antioxidant to alleviate oxidative injuries of DOX.

  5. The possible role of low doses of Cerastes cerastes crude venom in mitigating doxorubicin induced oxidative damage in male rats

    International Nuclear Information System (INIS)

    Salama, S.F.; AL-Sadoon, M.K.

    2012-01-01

    The purpose of this study was to investigate the possible role of Cerastes cerastes crude venom (CCV) in attenuating (doxorubicin) DOX oxidative damage in male rats. Forty male rats, matched in age and weight were sorted into four groups, control, CCV-group, DOX-group and CCV + DOX-groups. DOX given as a single dose i.p. injection of 10 mg per kg body weight) induced a significant increase in serum advanced oxidation protein products (AOPP),malondialdehyde (MDA), urea, total proteins, AST, ALT, triglycerides and cholesterol. Meanwhile significant decrease in reduced glutathione (GSH), superoxide dimutase (SOD),uric acid as well as RBCs, platelet counts, hemoglobin content (Hb), haematocrit value (Hct), total leukocytes, neutrophils and lymphocytes count was recorded after 14 days. CCV i.p. injected daily at a dose of 1/4 LD 50 for 14 days showed a significant decrease of the content of serum AOPP and MDA, lymphocytes and a significant increase of GSH, uric acid, RBCs count, Hb, Hct, total proteins, triglycerides, neutrophils count compared to control. In DOX+ CCV-group, CCV was given daily for 7 days before DOX, 10 mg/kg, followed by CCV for 7 more days, a significant inhibition of the serum triglycerides, cholesterol, urea and total protein, AST, ALT, AOPP, MDA, and a significant elevation of GSH, SOD, uric acid, RBCs, platelet counts, Hb, Hct, were shown as compared with DOX- group. It could be concluded that CCV at low doses can be used as a natural antioxidant to alleviate oxidative injuries of DOX.

  6. Low dose rate and high dose rate intracavitary treatment for cervical cancer

    International Nuclear Information System (INIS)

    Hareyama, Masato; Oouchi, Atsushi; Shidou, Mitsuo

    1997-01-01

    From 1984 through 1993, 144 previous untreated patients with carcinoma of uterine cervix were treated with either low dose rate 137 Cs therapy (LDR) or high dose rate 60 Co therapy (HDR). The local failure rates for more than 2-years for the primary lesions were 11.8% (8 of 63 patients) for LDR and 18.0% (11 of 61 patients). Rectal complication rates were significantly lower for HDR versus LDR (14.3% VS. 32.8%. p<0.01). Also, bladder complication rates were significantly lower for HDR versus LDR (0% VS. 10.4%, p<0.005). Treatment results in term of local control were equivalent for HDR and LDR treatment. However, the incidence of complications was higher for the LDR group than for the HDR group. (author)

  7. Calculated organ doses using Monte Carlo simulations in a reference male phantom undergoing HDR brachytherapy applied to localized prostate carcinoma

    International Nuclear Information System (INIS)

    Candela-Juan, Cristian; Perez-Calatayud, Jose; Ballester, Facundo; Rivard, Mark J.

    2013-01-01

    Purpose: The aim of this study was to obtain equivalent doses in radiosensitive organs (aside from the bladder and rectum) when applying high-dose-rate (HDR) brachytherapy to a localized prostate carcinoma using 60 Co or 192 Ir sources. These data are compared with results in a water phantom and with expected values in an infinite water medium. A comparison with reported values from proton therapy and intensity-modulated radiation therapy (IMRT) is also provided. Methods: Monte Carlo simulations in Geant4 were performed using a voxelized phantom described in International Commission on Radiological Protection (ICRP) Publication 110, which reproduces masses and shapes from an adult reference man defined in ICRP Publication 89. Point sources of 60 Co or 192 Ir with photon energy spectra corresponding to those exiting their capsules were placed in the center of the prostate, and equivalent doses per clinical absorbed dose in this target organ were obtained in several radiosensitive organs. Values were corrected to account for clinical circumstances with the source located at various positions with differing dwell times throughout the prostate. This was repeated for a homogeneous water phantom. Results: For the nearest organs considered (bladder, rectum, testes, small intestine, and colon), equivalent doses given by 60 Co source were smaller (8%–19%) than from 192 Ir. However, as the distance increases, the more penetrating gamma rays produced by 60 Co deliver higher organ equivalent doses. The overall result is that effective dose per clinical absorbed dose from a 60 Co source (11.1 mSv/Gy) is lower than from a 192 Ir source (13.2 mSv/Gy). On the other hand, equivalent doses were the same in the tissue and the homogeneous water phantom for those soft tissues closer to the prostate than about 30 cm. As the distance increased, the differences of photoelectric effect in water and soft tissue, and appearance of other materials such as air, bone, or lungs, produced

  8. Dietary intake of high-dose biotin inhibits spermatogenesis in young rats.

    Science.gov (United States)

    Sawamura, Hiromi; Ikeda, Chieko; Shimada, Ryoko; Yoshii, Yui; Watanabe, Toshiaki

    2015-02-01

    To characterize a new function of the water-soluble vitamin, biotin, in reproduction and early growth in mammals, the effects of high dietary doses of biotin on early spermatogenesis were biochemically and histologically investigated in male rats. Weaned rats were fed a CE-2 (control) diet containing 0.00004% biotin, or a control diet supplemented with 0.01%, 0.1%, or 1.0% biotin. Pair-fed rats were fed a control diet that was equal in calories to the amount ingested by the 1.0% biotin group, because food intake was decreased in the 1.0% biotin group. Food intake and body weight gain were lower in the 1.0% biotin group than in the control group. The kidney, brain and testis weights were significantly lower in the 1.0% biotin group than in the pair-fed group after 6 weeks of feeding. The accumulation of biotin in the liver and testis increased in a dose-dependent manner. In the 1.0% biotin group, the number of mature sperm was markedly lower, that of sperm with morphologically abnormal heads, mainly consisting of round heads, had increased. In addition, the development of seminiferous tubules was inhibited, and few spermatogonia and no spermatocytes were histologically observed. These results demonstrated that the long-term intake of high-dose biotin inhibited spermatogenesis in young male rats. © 2014 Japanese Teratology Society.

  9. Male gonadal dose an adjuvant 3-D-pelvic irradiation after anterior resection of rectal cancer. Influence to fertility

    International Nuclear Information System (INIS)

    Piroth, M.D.; Hensley, F.; Wannenmacher, M.; Zierhut, D.

    2003-01-01

    Background: Rectal cancer is a common malignant disease and occurs not infrequently in younger men. We verified the dose to the testes from scattered radiation in adjuvant pelvic irradiation following anterior resection of rectal cancer. Patients and Method: We measured the scattered gonadal dose of 18 patients in vivo with thermoluminescence detectors, which were fixed on four defined points on the scrotum during radiation on three consecutive days. All patients were treated three-dimensionally planned using a three-field box lying in prone position in a bellyboard. A total dose of 50.4 Gy was given in 28 fractions of 1.8 Gy. From 45 up to 50.4 Gy the radiation fields were modified to lateral-opposing fields which were shortened from the top to protect the small bowel. Results: The mean gonadal dose per fraction of all patients was 0.057 Gy (median 0.05 Gy) with a range between 0.035 and 0.114 Gy. The standard deviation was 0.02 Gy. The calculated cumulative mean gonadal dose after 28 fractions was 1.60 Gy (0.98-3.19 Gy). Conclusions: Germinal epithelium is very sensitive to low-dose irradiation, according to a negative fractionation effect. It is known that gonadal total doses of 1 Gy with single doses of 0.03-0.05 Gy can result in a temporary azoospermia with following recovery in most cases. If gonadal total doses exceed 1.5 Gy a substantial increase in irreversible azoospermia must be expected. With respect to the data reported in the literature our measured mean gonadal total dose of 1.60 Gy will lead with high probability to an irreversible infertility. Because of the small number of patients in our study, the data must be interpreted with caution, however, it is very important in patient's informed consent to draw attention to the high risk of infertility. The possibility of sperm cryoconservation should be discussed with the patient. (orig.) [de

  10. [A study on male high school students' smoking patterns].

    Science.gov (United States)

    Lee, K Y

    1997-01-01

    This study aims to investigate smoking patterns in high school student and to give student smoker effective information. The sample of 250 male high school students out of two different schools in Tae-Jŏn was questioned from July 10th to 15th, 1995. In analyzing these date, the statistics shows the realities by means of number of students. The results are summarized into 17 items as follows. Regarding the level of smoking, 140 students out of 250 admit that they have ever smoked, 52.1% of smoking students say that the motivation of beginning smoking is mainly curiosity. The survey shows that 22.9% of smoking students feel very good when smoking. It also shows that 30.0% of smoking students began smoking in the first grade of high school. With regard to the volume of smoking per day, 41.4% of smoking students smoke variably, 42.1% drink when smoking, 15.0% spend more than W 70,000 a month. About the question who knows the fact of their smoking, 51.5% answer that their friends know the fact of their smoking. In regard to the reslationship between smoking and school performance, 18.2% of non smoking students make poor grades as compared with 40% of smoking students, 9.3% of smoking students say that they are satisfied with the school life, but 35.7% of them are not satisfied. Regarding the attitude to smoking teachers, 35% of smoking students state that they are affected by them. 69.3% of smoking students say that they will stop smoking, while the remaining 30.7% say that they will keep smoking. The reason of 63.9% to stop smoking is that smoking is bad for the health. The reason of 46.5% to keep smoking is the acquired habit of smoking. 97.2% know the fact that the major element of cigarettes is nicotine and it is very harmful to the health. 40.8% recognize the harmful effect of smoking by TV and radio programs. 97.2% know that smoking could cause lung cancer. From the above results. I propose as follows We should make specific plan to keep smoking by simple

  11. High-dose secondary calibration laboratory accreditation program

    Energy Technology Data Exchange (ETDEWEB)

    Humphreys, J.C. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1993-12-31

    There is a need for high-dose secondary calibration laboratories to serve the multi-billion dollar radiation processing industry. This need is driven by the desires of industry for less costly calibrations and faster calibration-cycle response time. Services needed include calibration irradiations of routine processing dosimeters and the supply of reference standard transfer dosimeters for irradiation in the production processing facility. In order to provide measurement quality assurance and to demonstrate consistency with national standards, the high-dose secondary laboratories would be accredited by means of an expansion of an existing National Voluntary Laboratory Accreditation Program. A laboratory performance criteria document is under development to implement the new program.

  12. High-dose secondary calibration laboratory accreditation program

    International Nuclear Information System (INIS)

    Humphreys, J.C.

    1993-01-01

    There is a need for high-dose secondary calibration laboratories to serve the multi-billion dollar radiation processing industry. This need is driven by the desires of industry for less costly calibrations and faster calibration-cycle response time. Services needed include calibration irradiations of routine processing dosimeters and the supply of reference standard transfer dosimeters for irradiation in the production processing facility. In order to provide measurement quality assurance and to demonstrate consistency with national standards, the high-dose secondary laboratories would be accredited by means of an expansion of an existing National Voluntary Laboratory Accreditation Program. A laboratory performance criteria document is under development to implement the new program

  13. Anticoagulation and high dose liver radiation. A preliminary report

    International Nuclear Information System (INIS)

    Lightdale, C.J.; Wasser, J.; Coleman, M.; Brower, M.; Tefft, M.; Pasmantier, M.

    1979-01-01

    Two groups of patients were observed for evidence of acute radiation hepatitis during high dose radiation to the liver. The first group of 18 patients with metastatic liver disease received an average of 4,050 rad to the whole liver. Half received anticoagulation with warfarin. One patient on anticoagulation developed evidence of acute radiation hepatitis while 2 patients did so without anticoagulation. Eleven patients with Hodgkin's disease received 4,000 rad to the left lobe of the liver during extended field radiation. Four of these 11 patients were anticoagulated to therapeutic range. Only one of the fully anticoagulated patients showed changes on liver scan consistent with radiation hepatitis whereas three did so without anticoagulation. No serious sequelae from anticoagulation occurred in either group. These preliminary data suggest that anticoagulation may be safely administered with high dose hepatic radiation and that further trials with anticoagulation are warranted

  14. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun, E-mail: zhanghangjun@gmail.com

    2014-10-15

    Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations.

  15. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo

    International Nuclear Information System (INIS)

    Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun

    2014-01-01

    Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations

  16. Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline

    DEFF Research Database (Denmark)

    Kaae, Rikke; Agertoft, Lone; Pedersen, Sören

    2004-01-01

    OBJECTIVES: To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children. METHODS: Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxi...

  17. Radiotherapy and high-dose chemotherapy in advanced Ewing's tumors

    International Nuclear Information System (INIS)

    Pape, H.; Glag, M.; Gripp, S.; Wittkamp, M.; Schmitt, G.; Laws, H.J.; Kaik, B. van; Goebel, U.; Burdach, S.; Juergens, H.

    1999-01-01

    Background: Ewing's tumors are sensitive to radio- and chemotherapy. Patients with multifocal disease suffer a poor prognosis. Patients presenting primary bone marrow involvement or bone metastases at diagnosis herald a 3-year disease-free survival below 15%. The European Intergroup Cooperative Ewing's Sarcoma Study (EICESS) has established the following indications for high-dose therapy in advanced Ewing's tumors: Patients with primary multifocal bone disease, patients with early ( [de

  18. Dose characteristics of high-energy electrons, muons and photons

    International Nuclear Information System (INIS)

    Britvich, G.I.; Krupnyj, G.I.; Peleshko, V.N.; Rastsvetalov, Ya.N.

    1980-01-01

    Differential distribution of energy release at different depth of tissue-equivalent phantoms (plexiglas, polystyrene, polyethylene) at the energy of incident electrons, muons of 0.2-40 GeV and photons with the mean energy of 3.6 GeV are measured. The error of experimental results does not exceed 7%. On the basis of the data obtained dose characteristics of electrons, muons and photons for standard geometry are estimated. For all types of irradiation the maximum value of specific equivalent dose, nremxcm 2 /part. is presented. It is shown that published values of specific equivalent dose of electron radiation are higher in all the investigated energy range from 0.2 to 40 GeV, and for muon radiation a good agreement with the present experiment is observed. The highly precise results obtained which cover the wide dynamic range according to the energy of incident particles can serve as the basis for reconsidering the existing recommendations for dose characteristics of electron radiation [ru

  19. Ion exchange resins as high-dose radiation dosimeters

    International Nuclear Information System (INIS)

    Alian, A.; Dessouki, A.; El-Assay, N.B.

    1984-01-01

    This paper reports on the possibility of using various types of ion exchange resins as high-dose radiation dosimeters, by analysis of the decrease in exchange capacity with absorbed dose. The resins studied are Sojuzchim-export-Moscow Cation Exchanger KU-2 and Anion Exchanger AV-17 and Merck Cation Exchanger I, and Merck Anion Exchangers II and III. Over the dose range 1 to 100 kGy, the systems show linearity between log absorbed dose and decrease in resin ion exchange capacity. The slope of this response function differs for the different resins, depending on their ionic form and degree of cross-linking. The radiation sensitivity increases in the order KU-2; Exchanger I; AV-17; Exchanger II; Exchanger III. Merck resins with moisture content of 21% showed considerably higher radiation sensitivity than those with 2 to 3% moisture content. The mechanism of radiation-induced denaturing of the ion exchanger resins involves cleavage and decomposition of functional substituents, with crosslinking playing a stabilizing role, with water and its radiolytic products serving to inhibit radical recombination and interfering with the protection cage effect of crosslinking. (author)

  20. PLUTONIUM/HIGH-LEVEL VITRIFIED WASTE BDBE DOSE CALCULATION

    Energy Technology Data Exchange (ETDEWEB)

    J.A. Ziegler

    2000-11-20

    The purpose of this calculation is to provide a dose consequence analysis of high-level waste (HLW) consisting of plutonium immobilized in vitrified HLW to be handled at the proposed Monitored Geologic Repository at Yucca Mountain for a beyond design basis event (BDBE) under expected conditions using best estimate values for each calculation parameter. In addition to the dose calculation, a plutonium respirable particle size for dose calculation use is derived. The current concept for this waste form is plutonium disks enclosed in cans immobilized in canisters of vitrified HLW (i.e., glass). The plutonium inventory at risk used for this calculation is selected from Plutonium Immobilization Project Input for Yucca Mountain Total Systems Performance Assessment (Shaw 1999). The BDBE examined in this calculation is a nonmechanistic initiating event and the sequence of events that follow to cause a radiological release. This analysis will provide the radiological releases and dose consequences for a postulated BDBE. Results may be considered in other analyses to determine or modify the safety classification and quality assurance level of repository structures, systems, and components. This calculation uses best available technical information because the BDBE frequency is very low (i.e., less than 1.0E-6 events/year) and is not required for License Application for the Monitored Geologic Repository. The results of this calculation will not be used as part of a licensing or design basis.

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

    International Nuclear Information System (INIS)

    Chen Ying; Luo Yisheng; Cao Zhenshan; Liu Xiulin

    2006-01-01

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

  2. Survey on patient doses in cardiology in Latin America. Criteria for high skin doses follow up

    International Nuclear Information System (INIS)

    Duran, Ariel; Duro, Ivanna; Lopez, Leonardo; Ramirez, Alfredo; Herrera, Carlos; Navarro, Joaquin; Rivarola, Carlos; Lopez, Jose A.

    2008-01-01

    Full text: As part of the International Action Plan for Protection of Patients and supporting by the IAEA, a survey on patient doses in fluoroscopy guided procedures in cardiology in Latin America has been conducted since 2006. One of the objectives of the survey was to set criteria for the identification and evaluation of high skin doses in a certain number of patients to recommend a clinical follow up for potential radiation injuries (more than 3 Gy at the skin). The used methodology for the survey was initiated with two dedicated workshops held in Santiago de Chile (2005) and San Jose de Costa Rica (2007) involving relevant cardiologists from 15 different Latin American Countries. Some sessions were also attended by experts from the Regulatory and Health Authorities. Standardized forms to collect demographic and patient dosimetric data were agreed. Considering that most of the involved centres had still not dosimeters installed in the cardiology x-ray systems, it was agreed to collect data on fluoroscopy time and total number of cine frames per procedure. Relevant factors influencing radio sensitivity of the skin were also collected. Data from 10 countries representing a sample of 709 patients were received during the first year. Procedures included were diagnostic (DG) (coronary angiography and electrophysiology studies), therapeutic (TH) (percutaneous transluminal coronary angioplasties, cardiac ablations and valvuloplasties) or including both DG and TH. A total of 26 patients (3.7%) were selected for potential high skin doses. Initial considered criteria for selection were more than 30 minutes of fluoroscopy, more than 3,000 cine frames per procedure or patients with more than 100 kg of weight. Maximum reported values were 72 minutes and 8,100 frames. In addition, 5 of these patients were diabetic, 6 have previous fluoroscopy procedures and 5 were over 95 kg. The percentage of selected cases for clinical follow up derived from potential skin injuries seem

  3. Dose specification for 192Ir high dose rate brachytherapy in terms of dose-to-water-in-medium and dose-to-medium-in-medium

    International Nuclear Information System (INIS)

    Fonseca, Gabriel Paiva; Yoriyaz, Hélio; Tedgren, Åsa Carlsson; Nilsson, Josef; Persson, Maria; Reniers, Brigitte; Verhaegen, Frank

    2015-01-01

    Dose calculation in high dose rate brachytherapy with 192 Ir is usually based on the TG-43U1 protocol where all media are considered to be water. Several dose calculation algorithms have been developed that are capable of handling heterogeneities with two possibilities to report dose: dose-to-medium-in-medium (D m,m ) and dose-to-water-in-medium (D w,m ). The relation between D m,m and D w,m for 192 Ir is the main goal of this study, in particular the dependence of D w,m on the dose calculation approach using either large cavity theory (LCT) or small cavity theory (SCT). A head and neck case was selected due to the presence of media with a large range of atomic numbers relevant to tissues and mass densities such as air, soft tissues and bone interfaces. This case was simulated using a Monte Carlo (MC) code to score: D m,m, D w,m (LCT), mean photon energy and photon fluence. D w,m (SCT) was derived from MC simulations using the ratio between the unrestricted collisional stopping power of the actual medium and water. Differences between D m,m and D w,m (SCT or LCT) can be negligible (<1%) for some tissues e.g. muscle and significant for other tissues with differences of up to 14% for bone. Using SCT or LCT approaches leads to differences between D w,m (SCT) and D w,m (LCT) up to 29% for bone and 36% for teeth. The mean photon energy distribution ranges from 222 keV up to 356 keV. However, results obtained using mean photon energies are not equivalent to the ones obtained using the full, local photon spectrum. This work concludes that it is essential that brachytherapy studies clearly report the dose quantity. It further shows that while differences between D m,m and D w,m (SCT) mainly depend on tissue type, differences between D m,m and D w,m (LCT) are, in addition, significantly dependent on the local photon energy fluence spectrum which varies with distance to implanted sources. (paper)

  4. High dose vitamin K3 infusion in advanced hepatocellular carcinoma.

    Science.gov (United States)

    Sarin, Shiv K; Kumar, Manoj; Garg, Sanjay; Hissar, Syed; Pandey, Chandana; Sharma, Barjesh C

    2006-09-01

    The survival of patients with unresectable advanced hepatocellular carcinoma (HCC) with portal vein thrombosis is dismal. Current therapeutic options have limited efficacy. Vitamin K has been shown to have antitumor effect on HCC cells both in cell lines and patients with advanced HCC. The aim of this study was to assess the clinical efficacy of high dose vitamin K3 in the treatment of advanced HCC with portal vein thrombosis. Forty-two consecutive patients with advanced HCC (Stage C according to BCLC staging system) with portal vein thrombosis were randomized into two groups: (i) high dose vitamin K3 (n = 23); and (ii) placebo (n = 19). The vitamin K3 was administered by i.v. infusion of 50 mg/day with daily increase of dose by 50 mg for 6 days, followed by 20 mg i.m. twice daily for 2 weeks. Of the 23 patients treated with vitamin K, one (4.3%) achieved complete response and three (13%) partial response, for a total of four (17.4%) objective responders overall. The overall mean survival was 8.9 +/- 8.8 months (median: 6; range 1-37 months) in the vitamin K group and 6.8 +/- 5.3 months (median: 5; range 1.5-21 months) in the placebo group (P = 0.552). The mean duration of survival was longer in patients in the vitamin K group who achieved objective response (22.5 +/- 12.2; median: 21; range 11-37 months) as compared to patients not achieving objective response (6.1 +/- 4.6; median: 5; range 1-16 months) (P = 0.0.002). Portal vein thrombosis resolved with complete patency in one (4.35%) patient. Treatment with high dose vitamin K produces objective response in 17% patients with improved survival in patients achieving objective response; however, it does not affect the overall survival.

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  6. Methodology of high dose research in medical radiodiagnostic; Metodologia de investigacao de doses elevadas em radiodiagnostico medico

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Adriana E.; Martins, Cintia P. de S., E-mail: ird@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-11-01

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

  7. Early-life exposure to Tris(1,3-dichloroisopropyl) phosphate induces dose-dependent suppression of sexual behavior in male rats.

    Science.gov (United States)

    Kamishima, Manami; Hattori, Tatsuya; Suzuki, Go; Matsukami, Hidenori; Komine, Chiaki; Horii, Yasuyuki; Watanabe, Gen; Oti, Takumi; Sakamoto, Hirotaka; Soga, Tomoko; Parhar, Ishwar S; Kondo, Yasuhiko; Takigami, Hidetaka; Kawaguchi, Maiko

    2018-05-01

    Exposure to endocrine-disrupting chemicals may adversely affect animals, particularly during development. Tris(1,3-dichloroisopropyl) phosphate (TDCIPP) is an organophosphate with anti-androgen function in vitro that is present in indoor dust at relatively high concentrations. In male rats, androgens are necessary for the development of reproductive organs, as well as the endocrine and central nervous systems. However, we currently do not know the exact effects of TDCIPP exposure through suckling on subsequent reproductive behavior in males. Here, we show that TDCIPP exposure (25-250 mg kg -1 via oral administration over 28 consecutive days post-birth) suppressed male sexual behavior and reduced testes size. These changes were dose-dependent and appeared first in adults rather than in juveniles. These results demonstrate that TDCIPP exposure led to normal body growth and appearance in juveniles, but disrupted the endocrine system and physiology in adults. Therefore, assays should be performed using adult animals to ensure accuracy, and to confirm the influence of chemical substances given during early mammalian life. Copyright © 2017 John Wiley & Sons, Ltd.

  8. Routine quality control of high dose rate brachytherapy equipment

    International Nuclear Information System (INIS)

    Guzman Calcina, Carmen S.; Almeida, Adelaide de; Rocha, Jose R. Oliveira

    2001-01-01

    A Quality Assurance program should be installed also for High Dose Rate brachytherapy, in the order to achieve a correct dose administration to the patient and for the safety to those involved directly with the treatment. The work presented here has the following purposes: Analyze the types of equipment tests presented by the official protocols (TG40, TG56 e ARCAL XXX), evaluate the brachytherapy routine tests of protocols from various national and international radiotherapy services and compare the latter with those presented in the official protocols. As a result, we conclude the following: TG56 presents a higher number of tests when compared to the other official protocols and most of the tests presented by the analyzed services are present in TG56. A suggestion for a basic protocol is presented, emphasizing the periodicity and tolerance level of each of the tests. (author)

  9. Development of miniature γ dose rate monitor with high sensitivity

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  10. High-dose dosimetry using electron spin resonance (ESR) spectroscopy

    International Nuclear Information System (INIS)

    Kojima, Takuji; Tanaka, Ryuichi

    1992-01-01

    An electron spin resonance (ESR) dosimeter capable of measuring large doses of radiation in radiotherapy and radiation processing is outlined. In particular, an alanine/ESR dosimeter is discussed, focusing on the development of elements, the development of the ESR dosimetric system, the application of alanine/ESR dosimeter, and basic researches. Rod elements for gamma radiation and x radiation and film elements for electron beams are described in detail. The following recent applications of the alanine/ESR dosimeter are introduced: using as a transfer dosimeter, applying to various types of radiation, diagnosing the deterioration of radiological materials and equipments, and applying to ESR imaging. The future subjects to be solved in the alanine/ESR dosimetric system are referred to as follows: (1) improvement of highly accurate elements suitable for the measurement of various types of radiation, (2) establishment of sensitive calibration method of the ESR equipment itself, and (3) calibration and standardization of radiation doses. (K.N.) 65 refs

  11. Use of high irradiation doses for preservation of canned beef

    International Nuclear Information System (INIS)

    Hammad, A.A.I; Salem, F.A.; El-Sahy, K.M.; Rady, A.; Badr, H.H.

    1997-01-01

    The effect of high irradiation doses (11.25,22.5 and 45 KGy) on the bacteriology, organoleptic quality and shelf - life extension of beef meat that are hermetically sealed in metal cans was investigated in comparison with commercial heat sterilization. The unirradiated cans of pre cooked (enzyme inactivated) unirradiated beef were swollen after only one month of storage at ambient temperature (20-30 degree). Application of 11.25 and 22.5 kGy to vacuum packed and enzyme inactivated beef was not enough for sterilization and only delayed swelling of beef cans. Application of 45 KGy irradiation dose prevented swelling of beef vans up to 12 months at ambient temperature and provided meat product, similar to the commercial heat sterilized one, organoleptically acceptable and microbiologically safe. Running title: Radiation sterilization of meat

  12. High and low dose-rate brachytherapy for cervical carcinoma

    International Nuclear Information System (INIS)

    Orton, C.G.

    1998-01-01

    For the brachytherapy component of the r[iation treatment of cervical carcinoma, high dose rate (HDR) is slowly replacing conventional low dose rate (LDR) due primarily to r[iation safety and other physical benefits attributed to the HDR modality. Many r[iation oncologists are reluctant to make this change because of perceived r[iobiological dis[vantages of HDR. However, in clinical practice HDR appears to be as effective as LDR but with a lower risk of late complications, as demonstrated by one randomized clinical trial and two comprehensive literature and practice surveys. The reason for this appears to be that the r[iobiological dis[vantages of HDR are outweighed by the physical [vantages. (orig.)

  13. Calibration of high-dose radiation facilities (Handbook)

    International Nuclear Information System (INIS)

    Gupta, B.L.; Bhat, R.M.

    1986-01-01

    In India at present several high intensity radiation sources are used. There are 135 teletheraphy machines and 65 high intensity cobalt-60 sources in the form of gamma chambers (2.5 Ci) and PANBIT (50 Ci). Several food irradiation facilities and a medical sterilization plant ISOMED are also in operation. The application of these high intensity sources involve a wide variation of dose from 10 Gy to 100 kGy. Accurate and reproducible radiation dosimetry is essential in the use of these sources. This handbook is especially compiled for calibration of high-dose radiation facilities. The first few chapters discuss such topics as interaction of radiation with matter, radiation chemistry, radiation processing, commonly used high intensity radiation sources and their special features, radiation units and dosimetry principles. In the chapters which follow, chemical dosimeters are discussed in detail. This discussion covers Fricke dosimeter, FBX dosimeter, ceric sulphate dosimeter, free radical dosimetry, coloured indicators for irrdiation verification. A final chapter is devoted to practical hints to be followed in calibration work. (author)

  14. Low dose versus high dose anti-snake venom therapy in the treatment of haematotoxic snake bite in South India.

    Science.gov (United States)

    Joseph, Imanto M; Kuriakose, Cijoy K; Dev, Anand Vimal; Philip, George A

    2017-10-01

    Most of the studies on the appropriate dose of anti-snake venom (ASV) are from tertiary hospitals and the guidelines are unclear. Our observational study compared the outcomes of two prevalent treatment regimes for haematotoxic snake bite in a secondary care hospital in South India. The time to normalisation of whole blood clotting time, mortality and complications were not different between the groups. The average dose of ASV required in the low and high dose groups were 106 mL and 246 mL, respectively. Consequently, patients who received low dose ASV incurred approximately 50% less expense. Urticarial rashes were also significantly fewer in the low dose group.

  15. High Doses Gamma Radiolysis of PVC: Mechanisms of Degradation

    International Nuclear Information System (INIS)

    Colombani, J.

    2006-01-01

    PVC radiolysis leads to the formation of various degradation products: radicals, gas, oxidized products or polyenes. In order to predict the formation of the degradation products with regard to irradiation and ageing parameters, it is important to improve the understanding of the radiolysis mechanisms of PVC. Thus, we used several analytical techniques (Electron Spin Resonance, Fourier Transform Infrared spectroscopy, Nuclear Magnetic Resonance, Size Exclusion Chromatography) to get information on PVC samples irradiated at high doses (up to 4MGy) under different conditions. Gamma irradiation induces the formation of various radicals into PVC. Older studies were generally focused on the effect of low dose and/or low temperature irradiations on PVC. We present here ESR signals of PVC irradiated at high doses and at room temperature. We show that peroxyl radicals are producted by radiolysis under aerobe conditions and that polyenyl radicals are formed under anaerobe conditions. PVC radiolysis induces gas production and especially hydrogen chloride. Production of hydrogen chloride is well known until 1 MGy. We have studied by FTIR, the evolution of the quantity of HCl produced until 4 MGy. We show that higher irradiation dose leads to the lower radiolytic yield of HCl (G(HCl)). Moreover, G(HCl) obtained in aerobe conditions is about fourfold as great as G(HCl) observed in anaerobe radiolysis. Propagation and termination reactions induce degradation products: polyene sequences and crosslinking reactions are observed under anaerobe conditions; oxidized products with addition of chain scissions are formed under aerobe conditions. Although the literature about PVC radiolysis is rich, the main reacting pathways are not well established. Moreover the high doses studies are almost non-existent. We show by FTIR that aerobe radiolysis induces formation of ketons and acids. NMR experiments confirme these results but also focuse on small acids formed (with 2, 3 or 4 carbons). The

  16. High-dose radioiodine therapy of Graves disease

    International Nuclear Information System (INIS)

    Solodky, V.; Fomin, D.; Pestritskaya, E.

    2015-01-01

    Full text of publication follows. Objectives: to estimate the effectiveness and safety of the disease treatment under different modes of applying RIT. Materials and methods: 67 patients with the thyrotoxicosis condition associated with Graves disease were researched. The patients were divided into 2 groups: a control group with 25 people (18 women and 7 men), who underwent a low-dose therapy of 150-500 MBq; and a main group of 42 people (32 women and 10 men), who underwent a high-dose therapy of 550 and 800 MBq. The volume of thyroid prior to the treatment made up 23.8 ± 20 ml in the main group and 30.2 ± 23 ml in the control one. The average age in the high-dose group was 44.6 ±23 years old and in the low-dose -47.2 ± 24 years old. In terms of the hormone level before the RIT, 52% of the main group patients experienced euthyroidism, while 48% - thyrotoxicosis. The corresponding indices in the control group were 42% and 58% respectively. The cessation of the thyreostatic therapy came on 5. to 21. day prior to the treatment, with the average of 14 ±7 days in both groups. The diagnosis of the disease was based on ultrasonography, planar scintigraphy, the hormone level and antibody titer. The performance was assessed through the attainment of hypo-thyrosis and the transition to a substitutive hormonal therapy with L-thyroxine in 6 months or more. The attainment of euthyroidism was seen as a partial effect due to a possibility of relapse. Results: in 6 months a positive result in the form of hypo-thyrosis was achieved for 39 patients in the main group, which accounted for 93%, and 3 patients (7%) experienced euthyroidism. No symptomatic thyrotoxicosis relapses were revealed. In the control group, hypo-thyrosis was achieved by 18 patients, which accounted for 72%; euthyroidism came up to 12%; 4 patients needed a refresher course of RIT, which made up 16% of the group. 93% of the main group patients tolerated the treatment favourably. 3 patients complained of the

  17. Clinical Efficacy of a Single Two Gram Dose of Azithromycin Extended Release for Male Patients with Urethritis

    Directory of Open Access Journals (Sweden)

    Satoshi Takahashi

    2014-04-01

    Full Text Available To clarify the clinical efficacy of a single oral 2 g dose of azithromycin extended-release for heterosexual male patients with urethritis, and the current antimicrobial sensitivity of Neisseria gonorrhoeae to azithromycin, a prospective clinical trial was conducted from 2011–2013. In patients with gonococcal urethritis, the eradication rate was 90.9% (30 of 33. The susceptibility rates of isolated Neisseria gonorrhoeae strains to ceftriaxone, spectinomycin, cefixime and azithromycin were 100%, 100%, 95.3% (41/43 and 37.2% (16/43, respectively. In the patients with nongonococcal urethritis, the eradication rate was 90.0% (45 of 50. The microbiological eradication rates for the pathogens were 90.9% (30/33 for Neisseria gonorrhoeae, 91.5% (43/47 for Chlamydia trachomatis, 71.4% (5/7 for Mycoplasma genitalium, and 100% (13/13 for Ureaplasma urealyticum. The main adverse event was diarrhea and its manifestation rate was 35.2% (32 of 120. The symptom of diarrhea was mostly temporary and resolved spontaneously. The conclusion was that the treatment regimen with a single oral 2 g dose of azithromycin extended-release would be effective for patients with urethritis. However, the antimicrobial susceptibilities of Neisseria gonorrhoeae and Mycoplasma genitalium should be carefully monitored because of possible treatment failure.

  18. Clinical Efficacy of a Single Two Gram Dose of Azithromycin Extended Release for Male Patients with Urethritis.

    Science.gov (United States)

    Takahashi, Satoshi; Kiyota, Hiroshi; Ito, Shin; Iwasawa, Akihiko; Hiyama, Yoshiki; Uehara, Teruhisa; Ichihara, Koji; Hashimoto, Jiro; Masumori, Naoya; Sunaoshi, Kenichi; Takeda, Koichi; Suzuki, Nobukazu; Hosobe, Takahide; Goto, Hirokazu; Suzuki, Hidenori; Onodera, Shoichi

    2014-04-02

    To clarify the clinical efficacy of a single oral 2 g dose of azithromycin extended-release for heterosexual male patients with urethritis, and the current antimicrobial sensitivity of Neisseria gonorrhoeae to azithromycin, a prospective clinical trial was conducted from 2011-2013. In patients with gonococcal urethritis, the eradication rate was 90.9% (30 of 33). The susceptibility rates of isolated Neisseria gonorrhoeae strains to ceftriaxone, spectinomycin, cefixime and azithromycin were 100%, 100%, 95.3% (41/43) and 37.2% (16/43), respectively. In the patients with nongonococcal urethritis, the eradication rate was 90.0% (45 of 50). The microbiological eradication rates for the pathogens were 90.9% (30/33) for Neisseria gonorrhoeae, 91.5% (43/47) for Chlamydia trachomatis, 71.4% (5/7) for Mycoplasma genitalium, and 100% (13/13) for Ureaplasma urealyticum. The main adverse event was diarrhea and its manifestation rate was 35.2% (32 of 120). The symptom of diarrhea was mostly temporary and resolved spontaneously. The conclusion was that the treatment regimen with a single oral 2 g dose of azithromycin extended-release would be effective for patients with urethritis. However, the antimicrobial susceptibilities of Neisseria gonorrhoeae and Mycoplasma genitalium should be carefully monitored because of possible treatment failure.

  19. 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.

  20. Cooperative binding mitigates the high-dose hook effect.

    Science.gov (United States)

    Roy, Ranjita Dutta; Rosenmund, Christian; Stefan, Melanie I

    2017-08-14

    The high-dose hook effect (also called prozone effect) refers to the observation that if a multivalent protein acts as a linker between two parts of a protein complex, then increasing the amount of linker protein in the mixture does not always increase the amount of fully formed complex. On the contrary, at a high enough concentration range the amount of fully formed complex actually decreases. It has been observed that allosterically regulated proteins seem less susceptible to this effect. The aim of this study was two-fold: First, to investigate the mathematical basis of how allostery mitigates the prozone effect. And second, to explore the consequences of allostery and the high-dose hook effect using the example of calmodulin, a calcium-sensing protein that regulates the switch between long-term potentiation and long-term depression in neurons. We use a combinatorial model of a "perfect linker protein" (with infinite binding affinity) to mathematically describe the hook effect and its behaviour under allosteric conditions. We show that allosteric regulation does indeed mitigate the high-dose hook effect. We then turn to calmodulin as a real-life example of an allosteric protein. Using kinetic simulations, we show that calmodulin is indeed subject to a hook effect. We also show that this effect is stronger in the presence of the allosteric activator Ca 2+ /calmodulin-dependent kinase II (CaMKII), because it reduces the overall cooperativity of the calcium-calmodulin system. It follows that, surprisingly, there are conditions where increased amounts of allosteric activator actually decrease the activity of a protein. We show that cooperative binding can indeed act as a protective mechanism against the hook effect. This will have implications in vivo where the extent of cooperativity of a protein can be modulated, for instance, by allosteric activators or inhibitors. This can result in counterintuitive effects of decreased activity with increased concentrations of

  1. High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

    Science.gov (United States)

    Kaschieva, S.; Angelov, Ch; Dmitriev, S. N.

    2018-03-01

    The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.

  2. Differences in male and female spino-pelvic alignment in asymptomatic young adults: a three-dimensional analysis using upright low-dose digital biplanar X-rays.

    Science.gov (United States)

    Janssen, Michiel M A; Drevelle, Xavier; Humbert, Ludovic; Skalli, Wafa; Castelein, René M

    2009-11-01

    A three-dimensional analysis of spino-pelvic alignment in 60 asymptomatic young adult males and females. To analyze the differences in sagittal spino-pelvic alignment in a group of asymptomatic young adult males and females and describe gender specific reference values. Several spinal disorders like idiopathic scoliosis and Scheuermann's disease have a well-known sex-related prevalence ratio. As spino-pelvic alignment plays an important role in spinal biomechanics, it is imperative to analyze possible differences between the male and female spino-pelvic alignment. Furthermore, in spinal fusion surgery, normal sagittal balance should be recreated as closely as possible. An innovative biplanar ultra low-dose radiographic technique was used to obtain three-dimensional reconstructions of the spine (T1-L5), sacrum, and pelvis in a freestanding position of 30 asymptomatic young male and 30 young female adults. Values were calculated for thoracic kyphosis (T4-T12), lumbar lordosis (L1-S1), total and regional lumbopelvic lordosis (PRT12, PRL2, PRL4, and PRL5), sagittal plumb line of T1, T4, and T9 (HAT1, HAT4, and HAT9), T1-L5 sagittal spinal inclination, T9 sagittal offset, and pelvic parameters (pelvic tilt, sacral slope, and pelvic incidence). In addition, vertebral inclination in the sagittal plane of each vertebra was measured. Differences in spino-pelvic alignment between the sexes were analyzed. The female spine was more dorsally inclined (11 degrees vs. 8 degrees ; P = 0.003). High thoracic and thoracolumbar vertebrae were more dorsally inclined in women than in men. Thoracic kyphosis, lumbar lordosis, regional lumbopelvic lordosis, sagittal plumb lines, T9 sagittal offset, and pelvic parameters were not statistically different between the sexes. These results indicate that the female spine is definitely different from the male spine. The spine as whole and individual vertebrae in certain regions of the normal spine is more backwardly inclined in females than in

  3. The status of low dose rate and future of high dose rate Cf-252 brachytherapy

    International Nuclear Information System (INIS)

    Rivard, M.J.; Wierzbicki, J.G.; Van den Heuvel, F.; Chuba, P.J.; Fontanesi, J.

    1997-12-01

    This work describes the current status of the US low dose rate (LDR) Cf-252 brachytherapy program. The efforts undertaken towards development of a high dose rate (HDR) remotely after loaded Cf-252 source, which can accommodate 1 mg or greater Cf-252, are also described. This HDR effort is a collaboration between Oak Ridge National Laboratory (ORNL), commercial remote after loader manufactures, the Gershenson Radiation Oncology Center (ROC), and Wayne State University. To achieve this goal, several advances in isotope chemistry and source preparation at ORNL must be achieved to yield a specific material source loading of greater than or equal 1 mg Cf-252 per mm3. Development work with both radioactive and non-radioactive stand-ins for Cf-252 have indicated the feasibility of fabricating such sources. As a result, the decreased catheter diameter and computer controlled source placement will permit additional sites (e.g. brain, breast, prostate, lung, parotid, etc.) to be treated effectively with Cf-252 sources. Additional work at the Radiochemical Engineering and Development Center (REDC) remains in source fabrication, after loader modification, and safe design. The current LDR Cf-252 Treatment Suite at the ROC is shielded and licensed to hold up to 1 mg of Cf-252. This was designed to maintain cumulative personnel exposure, both external to the room and in direct isotope handling, at less than 20 microSv/hr. However, cumulative exposure may be greatly decreased if a Cf-252 HDR unit is employed which would eliminate direct isotope handling and decrease treatment times from tilde 3 hours to an expected range of 3 to 15 minutes. Such a Cf-252 HDR source will also demonstrate improved dose distributions over current LDR treatments due to the ability to step the point-like source throughout the target volume and weight the dwell time accordingly

  4. The Impact of High School on the Leadership Development of African American Male Scholar-Athletes

    Science.gov (United States)

    Fuller, Rhema; Harrison, C. Keith; Bukstein, Scott; Martin, Brandon E.; Lawerence, Malia; Parks, Cliff

    2017-01-01

    The purpose of this article is to examine how the high school setting assisted the leadership development of African American males. Additionally, we explored how the leadership developed in high school was applied in the post-high school setting. We utilized purposeful sampling to identify and recruit African American male scholar-athletes (N =…

  5. 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

  6. High-pitch computed tomography coronary angiography-a new dose-saving algorithm: estimation of radiation exposure.

    Science.gov (United States)

    Ketelsen, Dominik; Buchgeister, Markus; Korn, Andreas; Fenchel, Michael; Schmidt, Bernhard; Flohr, Thomas G; Thomas, Christoph; Schabel, Christoph; Tsiflikas, Ilias; Syha, Roland; Claussen, Claus D; Heuschmid, Martin

    2012-01-01

    Purpose. To estimate effective dose and organ equivalent doses of prospective ECG-triggered high-pitch CTCA. Materials and Methods. For dose measurements, an Alderson-Rando phantom equipped with thermoluminescent dosimeters was used. The effective dose was calculated according to ICRP 103. Exposure was performed on a second-generation dual-source scanner (SOMATOM Definition Flash, Siemens Medical Solutions, Germany). The following scan parameters were used: 320 mAs per rotation, 100 and 120 kV, pitch 3.4 for prospectively ECG-triggered high-pitch CTCA, scan range of 13.5 cm, collimation 64 × 2 × 0.6 mm with z-flying focal spot, gantry rotation time 280 ms, and simulated heart rate of 60 beats per minute. Results. Depending on the applied tube potential, the effective whole-body dose of the cardiac scan ranged from 1.1 mSv to 1.6 mSv and from 1.2 to 1.8 mSv for males and females, respectively. The radiosensitive breast tissue in the range of the primary beam caused an increased female-specific effective dose of 8.6%±0.3% compared to males. Decreasing the tube potential, a significant reduction of the effective dose of 35.8% and 36.0% can be achieved for males and females, respectively (P < 0.001). Conclusion. The radiologist and the CT technician should be aware of this new dose-saving strategy to keep the radiation exposure as low as reasonablly achievable.

  7. Stock selection of high-dose-irradiation-resistant materials for filter press under high-dose irradiation operation

    International Nuclear Information System (INIS)

    Ishiyama, Shintaro; Minami, Mamoru; Hara, Kouji; Yamashita, Manabu

    2015-01-01

    In a volume reduction process for the decontamination of contained soil, the performance degradation of a filter press is expected owing to material deterioration under high-dose irradiation. Eleven-stock selection of candidate materials including polymers, fibers and rubbers for the filter press was conducted to achieve a high performance of volume reduction of contaminated soil and the following results were derived. Crude rubber and nylon were selected as prime candidates for packing, diaphragm and filter plate materials. Polyethylene was also selected as a prime candidate for the filter cloth material. (author)

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  9. Conventional-Dose versus High-Dose Chemotherapy for Relapsed Germ Cell Tumors

    Directory of Open Access Journals (Sweden)

    Deaglan J. McHugh

    2018-01-01

    Full Text Available The majority of metastatic germ cell tumors (GCTs are cured with cisplatin-based chemotherapy, but 20–30% of patients will relapse after first-line chemotherapy and require additional salvage strategies. The two major salvage approaches in this scenario are high-dose chemotherapy (HDCT with autologous stem cell transplant (ASCT or conventional-dose chemotherapy (CDCT. Both CDCT and HDCT have curative potential in the management of relapsed/refractory GCT. However, due to a lack of conclusive randomized trials, it remains unknown whether sequential HDCT or CDCT represents the optimal initial salvage approach, with practice varying between tertiary institutions. This represents the most pressing question remaining for defining GCT treatment standards and optimizing outcomes. The authors review prognostic factors in the initial salvage setting as well as the major studies assessing the efficacy of CDCT, HDCT, or both, describing the strengths and weaknesses that formed the rationale behind the ongoing international phase III “TIGER” trial.

  10. Prehospital high-dose sublingual nitroglycerin rarely causes hypotension.

    Science.gov (United States)

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

    2013-10-01

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

  11. High-dose irradiated food: Current progress, applications, and prospects

    Science.gov (United States)

    Feliciano, Chitho P.

    2018-03-01

    Food irradiation as an established and mature technology has gained more attention in the food industry for ensuring food safety and quality. Primarily used for phytosanitary applications, its use has been expanded for developing various food products for varied purposes (e.g. ready-to-eat & ready-to-cook foods, hospital diets, etc.). This paper summarized and analyzed the recent progress and application of high-dose irradiation and discussed its prospects in the field of food product development, its safety and quality.

  12. SU-F-P-19: Fetal Dose Estimate for a High-Dose Fluoroscopy Guided Intervention Using Modern Data Tools

    Energy Technology Data Exchange (ETDEWEB)

    Moirano, J [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: An accurate dose estimate is necessary for effective patient management after a fetal exposure. In the case of a high-dose exposure, it is critical to use all resources available in order to make the most accurate assessment of the fetal dose. This work will demonstrate a methodology for accurate fetal dose estimation using tools that have recently become available in many clinics, and show examples of best practices for collecting data and performing the fetal dose calculation. Methods: A fetal dose estimate calculation was performed using modern data collection tools to determine parameters for the calculation. The reference point air kerma as displayed by the fluoroscopic system was checked for accuracy. A cumulative dose incidence map and DICOM header mining were used to determine the displayed reference point air kerma. Corrections for attenuation caused by the patient table and pad were measured and applied in order to determine the peak skin dose. The position and depth of the fetus was determined by ultrasound imaging and consultation with a radiologist. The data collected was used to determine a normalized uterus dose from Monte Carlo simulation data. Fetal dose values from this process were compared to other accepted calculation methods. Results: An accurate high-dose fetal dose estimate was made. Comparison to accepted legacy methods were were within 35% of estimated values. Conclusion: Modern data collection and reporting methods ease the process for estimation of fetal dose from interventional fluoroscopy exposures. Many aspects of the calculation can now be quantified rather than estimated, which should allow for a more accurate estimation of fetal dose.

  13. Identification of dose-reduction techniques for BWR and PWR repetitive high-dose jobs

    International Nuclear Information System (INIS)

    Dionne, B.J.; Baum, J.W.

    1984-01-01

    As a result of concern about the apparent increase in collective radiation dose to workers at nuclear power plants, this project will provide information to industry in preplanning for radiation protection during maintenance operations. This study identifies Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR) repetitive jobs, and respective collective dose trends and dose reduction techniques. 3 references, 2 tables

  14. The Effect of High Dose Radioiodine Therapy on Formation of Radiation Retinopathy During Thyroid Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Tülay Kaçar Güvel

    2014-10-01

    Full Text Available Objective: Non-thyroidal complication of high-dose radioiodine therapy for thyroid carcinoma might cause salivary and lacrimal gland dysfunction, which may be transient or permanent in a dose-dependent manner. However, radiation retinopathy complicating 131I therapy, has not been previously well characterized. The aim of this study was to evaluate the extent of retinal damage among patients who had received high doses of radioiodine treatment. Methods: Forty eyes of 20 patients (3 male, 17 female who received 250-1000 mCi during 131I therapy and on ophthalmological follow up for a year after the last treatment were included in the study. Mean age of the study group was 50 years (range 25-70 years. In ophthalmologic examination, visual acuity was measured in order to determine visual loss. Intraocular pressure was measured in all the patients. Then lens examination was carried out with slit lamp biomicroscopy in order to investigate cataract or partial lens opacities. Fundus observation was carried out through the dilated pupil with slit lamp biomicroscopy using 90 D noncontact lens. Result: The best corrected visual aquity with Snellen chart was found as 1.0 in 36 eyes (90% and between 0.6 and 0.9 (10% in 4 eyes (10%. At the biomicroscopic fundus examination, retinal hemorrhage consistent with radiation retinopathy, microaneurysm, microinfarction, edema or exudation, vitreus hemorrhage, partial or total optical disc pallor indicating papillopathy in the optic disc were not observed in any of the eyes. Conclusion: This result indicates that there is not any significant correlation between repeated high-dose radioiodine therapy and radiation retinopathy in differentiated thyroid carcinomas. Even though there is not a significant restriction in use of higher doses of radioiodine therapy in differentiated thyroid carcinoma, more extensive studies are needed in order to obtain more accurate data on possible occurrence of retinopathy.

  15. Determination of the dose of gamma radiation sterilization for assessment of biological parameters of male Ceratitis capitada (Diptera: Tephritidae), tsl - Vienna 8 strain

    International Nuclear Information System (INIS)

    Rocha, Aline Cristina Pereira da

    2011-01-01

    The Vienna-8, tsl (temperature sensitive lethal) strain of Ceratitis capitata, by presenting mutations that facilitate the mass rearing and release only of sterile males in the field, has been used in (Sterile Insect Technique) programmes. The objective of this study was to determine the radiation dose that provides the highest level of sterility for Vienna-8, tsl males assessing their biological parameters that indicate the quality of sterile males to be released. Brown pupae (males) of the tsl strain were obtained from the mass rearing of the Food Irradiation and Radio entomology laboratory of CENA/USP, and they were irradiated (with gamma radiation - 60 Co) 24 hours before the emergence at rates of 0, 30, 60, 90 and 120 Gy. The determination of the sterilizing dose was based on fertility of sexually mature females of the bisexual strain and not irradiated, mated with males of different treatments. Eggs were collected daily during 6 days, were counted and it was possible to estimate fecundity, and assess the hatching rate. The emergence and flight ability were determined by following the protocol of quality control manual for FAO/IAEA/USDA (2003). To assess the longevity under nutritional stress, the insects were kept a period of 48 h after emergence in the absence of water and food, and after this period, mortality was recorded. The size of the testes (left and right) was obtained by dissecting irradiated and non-irradiated males at the eighth day of life, and measure the testes in an ocular micrometer, considering the maximum length and width of each sample. To determine the sperm number was necessary to dissect the males and break their testicles. No difference was observed in emergence rate, flight ability and longevity of irradiated and non-irradiated males, nor in the fecundity of females mated with males of different treatments. The sterilizing dose that resulted in lower fertility of females was 120 Gy, with 1.5% hatching. Considering the parameters of

  16. Secondary radiation dose during high-energy total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Janiszewska, M.; Raczkowski, M. [Lower Silesian Oncology Center, Medical Physics Department, Wroclaw (Poland); Polaczek-Grelik, K. [University of Silesia, Medical Physics Department, Katowice (Poland); Szafron, B.; Konefal, A.; Zipper, W. [University of Silesia, Department of Nuclear Physics and Its Applications, Katowice (Poland)

    2014-05-15

    The goal of this work was to assess the additional dose from secondary neutrons and γ-rays generated during total body irradiation (TBI) using a medical linac X-ray beam. Nuclear reactions that occur in the accelerator construction during emission of high-energy beams in teleradiotherapy are the source of secondary radiation. Induced activity is dependent on the half-lives of the generated radionuclides, whereas neutron flux accompanies the treatment process only. The TBI procedure using a 18 MV beam (Clinac 2100) was considered. Lateral and anterior-posterior/posterior-anterior fractions were investigated during delivery of 2 Gy of therapeutic dose. Neutron and photon flux densities were measured using neutron activation analysis (NAA) and semiconductor spectrometry. The secondary dose was estimated applying the fluence-to-dose conversion coefficients. The main contribution to the secondary dose is associated with fast neutrons. The main sources of γ-radiation are the following: {sup 56}Mn in the stainless steel and {sup 187}W of the collimation system as well as positron emitters, activated via (n,γ) and (γ,n) processes, respectively. In addition to 12 Gy of therapeutic dose, the patient could receive 57.43 mSv in the studied conditions, including 4.63 μSv from activated radionuclides. Neutron dose is mainly influenced by the time of beam emission. However, it is moderated by long source-surface distances (SSD) and application of plexiglass plates covering the patient body during treatment. Secondary radiation gives the whole body a dose, which should be taken into consideration especially when one fraction of irradiation does not cover the whole body at once. (orig.) [German] Die zusaetzliche Dosis durch sekundaere Neutronen- und γ-Strahlung waehrend der Ganzkoerperbestrahlung mit Roentgenstrahlung aus medizinischen Linearbeschleunigern wurde abgeschaetzt. Bei der Emission hochenergetischer Strahlen zur Teletherapie finden hauptsaechlich im Beschleuniger

  17. Physics and quality assurance for high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Anderson, Lowell L.

    1995-01-01

    Purpose: To review the physical aspects of high dose rate (HDR) brachytherapy, including commissioning and quality assurance, source calibration and dose distribution measurements, and treatment planning methods. Following the introduction of afterloading in brachytherapy, development efforts to make it 'remote' culminated in 1964 with the near-simultaneous appearance of remote afterloaders in five major medical centers. Four of these machines were 'high dose rate', three employing 60Co and one (the GammaMed) using a single, cable-mounted 192Ir source. Stepping-motor source control was added to the GammaMed in 1974, making it the precursor of modern remote afterloaders, which are now suitable for interstitial as well as intracavitary brachytherapy by virtue of small source-diameter and indexer-accessed multiple channels. Because the 192Ir sources currently used in HDR remote afterloaders are supplied at a nominal air-kerma strength of 11.4 cGy cm2 s-1 (10 Ci), are not collimated in clinical use, and emit a significant fraction (15%) of photons at energies greater than 600 keV, shielding and facility design must be undertaken as carefully and thoroughly as for external beam installations. Licensing requirements of regulatory agencies must be met with respect both to maximum permissible dose limits and to the existence and functionality of safety devices (door interlocks, radiation monitors, etc.). Commissioning and quality assurance procedures that must be documented for HDR remote afterloading relate to (1) machine, applicator, guide-tube, and facility functionality checks, (2) source calibration, (3) emergency response readiness, (4) planning software evaluation, and (5) independent checks of clinical dose calculations. Source calibration checks must be performed locally, either by in-air measurement of air kerma strength or with a well ionization chamber calibrated (by an accredited standards laboratory) against an in-air measurement of air kerma strength for the

  18. The usefulness of metal markers for CTV-based dose prescription in high-dose-rate interstitial brachytherapy

    International Nuclear Information System (INIS)

    Yoshida, Ken; Mitomo, Masanori; Nose, Takayuki; Koizumi, Masahiko; Nishiyama, Kinji; Yoshida, Mineo

    2002-01-01

    We employ a clinical target volume (CTV)-based dose prescription for high-dose-rate (HDR) interstitial brachytherapy. However, it is not easy to define CTV and organs at risk (OAR) from X-ray film or CT scanning. To solve this problem, we have utilized metal markers since October 1999. Moreover, metal markers can help modify dose prescription. By regulating the doses to the metal markers, refining the dose prescription can easily be achieved. In this research, we investigated the usefulness of the metal markers. Between October 1999 and May 2001, 51 patients were implanted with metal markers at Osaka Medical Center for Cancer and Cardiovascular Diseases (OMCC), Osaka National Hospital (ONH) and Sanda City Hospital (SCH). Forty-nine patients (head and neck: 32; pelvis: 11; soft tissue: 3; breast: 3) using metal markers were analyzed. During operation, we implanted 179 metal markers (49 patients) to CTV and 151 markers (26 patients) to OAR. At treatment planning, CTV was reconstructed judging from the metal markers, applicator position and operation records. Generally, we prescribed the tumoricidal dose to an isodose surface that covers CTV. We also planned to limit the doses to OAR lower than certain levels. The maximum normal tissue doses were decided 80%, 150%, 100%, 50% and 200% of the prescribed doses for the rectum, the urethra, the mandible, the skin and the large vessel, respectively. The doses to the metal markers using CTV-based dose prescription were generated. These were compared with the doses theoretically calculated with the Paris system. Treatment results were also investigated. The doses to the 158 metal markers (42 patients) for CTV were higher than ''tumoricidal dose''. In 7 patients, as a result of compromised dose prescription, 9 markers were lower than the tumoricidal dose. The other 12 markers (7%) were excluded from dose evaluation because they were judged as miss-implanted. The doses to the 142 metal markers (24 patients) for OAR were lower

  19. Proconvulsant effects of high doses of venlafaxine in pentylenetetrazole-convulsive rats

    Directory of Open Access Journals (Sweden)

    J.G. Santos Junior

    2002-04-01

    Full Text Available Venlafaxine, an atypical antidepressant drug, has been used to treat several neurological disorders, presenting excellent efficacy and tolerability. Clinical seizures after venlafaxine treatment have occasionally been reported when the drug was used at very high doses or in combination with other medications. The aim of the present study was to investigate the convulsant effects of venlafaxine in rats under controlled laboratory conditions. Adult male Wistar rats (8 per group receiving venlafaxine or saline at the doses of 25-150 mg/kg were subjected 30 min later to injections of pentylenetetrazole at the dose of 60 mg/kg. The animals receiving 75, 100 and 150 mg/kg venlafaxine presented increased severity of convulsion when compared to controls (P = 0.02, P = 0.04, and P = 0.0004, respectively. Indeed, an increased percentage of death was observed in these groups (50, 38, and 88%, respectively when compared to the percentage of death in the controls (0%. The group receiving 150 mg/kg showed an reduction in death latency (999 ± 146 s compared to controls (1800 ± 0 s; cut-off time. Indeed, in this group, all animals developed seizures prior to pentylenetetrazole administration. Surprisingly, the groups receiving venlafaxine at the doses of 25 and 50 mg/kg showed a tendency towards an increase in the latency to the first convulsion. These findings suggest that venlafaxine at doses of 25 and 50 mg/kg has some tendency to an anticonvulsant effect in the rat, whereas doses of 75, 100 and 150 mg/kg presented clear proconvulsant effects in rats submitted to the pentylenetetrazole injection. These findings are the first report in the literature concerning the role of venlafaxine in seizure genesis in the rat under controlled conditions.

  20. Clinical application of a OneDose(TM) MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast

    International Nuclear Information System (INIS)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-01-01

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose(TM) in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs. (note)

  1. Clinical application of a OneDose MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast.

    Science.gov (United States)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-07-21

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs.

  2. Selective brain responses to acute and chronic low-dose X-ray irradiation in males and females

    International Nuclear Information System (INIS)

    Silasi, Greg; Diaz-Heijtz, Rochellys; Besplug, Jill; Rodriguez-Juarez, Rocio; Titov, Viktor; Kolb, Bryan; Kovalchuk, Olga

    2004-01-01

    Radiation exposure is known to have profound effects on the brain, leading to precursor cell dysfunction and debilitating cognitive declines [Nat. Med. 8 (2002) 955]. Although a plethora of data exist on the effects of high radiation doses, the effects of low-dose irradiation, such as ones received during repetitive diagnostic and therapeutic exposures, are still under-investigated [Am. J. Otolaryngol. 23 (2002) 215; Proc. Natl. Acad. Sci. USA 97 (2000) 889; Curr. Opin. Neurol. 16 (2003) 129]. Furthermore, most studies of the biological effects of ionizing radiation have been performed using a single acute dose, while clinically and environmentally relevant exposures occur predominantly under chronic/repetitive conditions. Here, we have used a mouse model to compare the effects of chronic/repetitive and acute low-dose radiation (LDR) exposure (0.5 Gy) to ionizing radiation on the brain in vivo. We examined the LDR effects on p42/44 MAPK (ERK1/ERK2), CaMKII, and AKT signaling-the interconnected pathways that have been previously shown to be crucial for neuronal survival upon irradiation. We report perturbations in ERK1/2, AKT, and CREB upon acute and chronic/repetitive low-dose exposure in the hippocampus and frontal cortex of mice. These studies were paralleled by the analysis of radiation effects on neurogenesis and cellular proliferation. Repetitive exposure had a much more pronounced effect on cellular signaling and neurogenesis than acute exposure. These results suggest that studies of single acute exposures might be limited in terms of their predictive value. We also present the first evidence of sex differences in radiation-induced signaling in the hippocampus and frontal cortex. We show the role of estrogens in brain radiation responses and discuss the implications of the observed changes

  3. Endocrine function following high dose proton therapy for tumors of the upper clivus

    Energy Technology Data Exchange (ETDEWEB)

    Slater, J.D.; Austin-Seymour, M.; Munzenrider, J.; Birnbaum, S.; Carroll, R.; Klibanski, A.; Riskind, P.; Urie, M.; Verhey, L.; Goitein, M.

    1988-09-01

    The endocrine status of patients receiving proton radiation for tumors of the upper clivus was reviewed to evaluate the effect of high dose treatment on the pituitary gland. The fourteen patients had chordomas or low grade chondrosarcomas and were all treated by the same techniques. The median tumor dose was 69.7 Cobalt Gray Equivalent (CGE) with a range from 66.6 to 74.4 CGE. (CGE is used because modulated protons have an RBE of 1.1 compared to 60Co). The daily fraction size was 1.8-2.1 CGE. The median follow-up time is 48 months, ranging from 30 to 68 months. All treatments were planned using a computerized multi-dimensional system with the position of the pituitary outlined on the planning CT scan. Review of the dose distribution indicated that the dose to the pituitary ranged from 60.5 to 72.3 CGE, with a median of 67.6 CGE. One female patient had decreased thyroid and gonadotropin function at the time of diagnosis and has been on hormone replacement since that time. The other three females were all pre-menopausal at the time of radiotherapy. At this time four patients (3 males and 1 female) have developed endocrine abnormalities 14 to 45 months after irradiation. All four had evidence of hypothyroidism and two have also developed corticotropin deficiency. The three males had decreased testosterone levels; the female patient developed amenorrhea and hyperprolactinemia. All four are asymptomatic with ongoing hormone replacement.

  4. Endocrine function following high dose proton therapy for tumors of the upper clivus

    International Nuclear Information System (INIS)

    Slater, J.D.; Austin-Seymour, M.; Munzenrider, J.

    1988-01-01

    The endocrine status of patients receiving proton radiation for tumors of the upper clivus was reviewed to evaluate the effect of high dose treatment on the pituitary gland. The fourteen patients had chordomas or low grade chondrosarcomas and were all treated by the same techniques. The median tumor dose was 69.7 Cobalt Gray Equivalent (CGE) with a range from 66.6 to 74.4 CGE. (CGE is used because modulated protons have an RBE of 1.1 compared to 60Co). The daily fraction size was 1.8-2.1 CGE. The median follow-up time is 48 months, ranging from 30 to 68 months. All treatments were planned using a computerized multi-dimensional system with the position of the pituitary outlined on the planning CT scan. Review of the dose distribution indicated that the dose to the pituitary ranged from 60.5 to 72.3 CGE, with a median of 67.6 CGE. One female patient had decreased thyroid and gonadotropin function at the time of diagnosis and has been on hormone replacement since that time. The other three females were all pre-menopausal at the time of radiotherapy. At this time four patients (3 males and 1 female) have developed endocrine abnormalities 14 to 45 months after irradiation. All four had evidence of hypothyroidism and two have also developed corticotropin deficiency. The three males had decreased testosterone levels; the female patient developed amenorrhea and hyperprolactinemia. All four are asymptomatic with ongoing hormone replacement

  5. Radiation safety program in a high dose rate brachytherapy facility

    International Nuclear Information System (INIS)

    Rodriguez, L.V.; Hermoso, T.M.; Solis, R.C.

    2001-01-01

    The use of remote afterloading equipment has been developed to improve radiation safety in the delivery of treatment in brachytherapy. Several accidents, however, have been reported involving high dose-rate brachytherapy system. These events, together with the desire to address the concerns of radiation workers, and the anticipated adoption of the International Basic Safety Standards for Protection Against Ionizing Radiation (IAEA, 1996), led to the development of the radiation safety program at the Department of Radiotherapy, Jose R. Reyes Memorial Medical Center and at the Division of Radiation Oncology, St. Luke's Medical Center. The radiation safety program covers five major aspects: quality control/quality assurance, radiation monitoring, preventive maintenance, administrative measures and quality audit. Measures for evaluation of effectiveness of the program include decreased unnecessary exposures of patients and staff, improved accuracy in treatment delivery and increased department efficiency due to the development of staff vigilance and decreased anxiety. The success in the implementation required the participation and cooperation of all the personnel involved in the procedures and strong management support. This paper will discuss the radiation safety program for a high dose rate brachytherapy facility developed at these two institutes which may serve as a guideline for other hospitals intending to install a similar facility. (author)

  6. Dosimetric properties of commercial glasses and sand for high doses

    International Nuclear Information System (INIS)

    Teixeira, Maria Ines

    2004-01-01

    Commercial glasses (transparent and colored) produced by Cebrace, Brazil, Sao Paulo, and sand samples of different Brazilian beaches were studied, due to their low cost and easy handling, to verify the possibility of their use in high dose dosimetry. The main dosimetric characteristics were determined using a densitometer, a spectrophotometer, a thermoluminescent (TL) reader and an electronic paramagnetic resonance system. The gamma irradiations were carried out using a Gamma-Cell 220 and a panoramic source ( 60 Co) of IPEN. An optical absorption band was observed at 420 nm in the glass samples. The TL glow curves presented peaks at 205 deg C, 135 deg C, 150 deg C and 145 deg C for the transparent, bronze, brown and green glass samples, respectively. All EPR spectra of the glasses showed Fe 3+ characteristic signals at g = 4.27 and 2.01. The gamma irradiated sand samples presented two peaks at 110 deg C and 170 deg C and an EPR signal at g= 1.999. However, these materials present a pronounced thermal fading at room temperature after irradiation. With the objective to minimize this thermal fading, both glass and sand samples were submitted to different pre- and post-irradiation thermal treatments. The glass and sand samples showed the possibility of utilization for high dose dosimetry and as Yes/No irradiation detectors. (author)

  7. Audits in high dose rate brachytherapy in Brazil

    International Nuclear Information System (INIS)

    Marechal, M.H.; Rosa, L.A.; Velasco, A.; Paiva, E. de; Goncalves, M.; Castelo, L.C.

    2002-01-01

    The lack of well established dosimetry protocols for HDR sources is a point of great concern regarding the uniformity of procedures within a particular country. The main objective of this paper is to report the results of an implementation of the audit program in dosimetry of high dose rate brachytherapy sources used by the radiation therapy centers in Brazil. In Brazil, among 169 radiotherapy centers, 35 have HDR brachytherapy systems. This program started in August 2001 and until now eight radiotherapy services were audited. The audit program consists of the visit in loco to each center and the evaluation of the intensity of the source with a well type chamber specially design for HDR 192 Ir sources. The measurements was carried out with a HDR1000PLUS Brachytherapy Well Type Chamber and a MAX 4000 Electrometer, both manufactured by Standard Imaging Inc. The chamber was calibrated in air kerma strength by the Accredited Dosimetry Calibration Laboratory, Department of Medical Physics, University of Wisconsin in the USA. The same chamber was calibrated in Brazil using a 192 lr high dose rate source whose intensity was determined by 60 Co gamma rays and 250 kV x rays interpolation methodology. The Nk of 60 Co and 250 kV x rays were provided by the Brazilian National Standard Laboratory for Ionizing Radiation (LMNRI)

  8. Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

    2000-01-01

    As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

  9. Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

    2000-10-01

    As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

  10. Space and place in researching male early high school leaving in ...

    African Journals Online (AJOL)

    Space and place in researching male early high school leaving in Orange Farm Township. ... South African Journal of Education ... I reflect on the methodological processes underpinning a dissertation that investigated male learners' reasons for leaving high school early and the strategies they employed to negotiate ...

  11. Space and Place in Researching Male Early High School Leaving in Orange Farm Township

    Science.gov (United States)

    Bingma, Vangile

    2013-01-01

    I reflect on the methodological processes underpinning a dissertation that investigated male learners' reasons for leaving high school early and the strategies they employed to negotiate everyday life. A qualitative case study was conducted with nine male early high school leavers between the ages of 18 and 25, as well as 12 stakeholders involved…

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  13. High-Dose Versus Low-Dose Pitavastatin in Japanese Patients With Stable Coronary Artery Disease (REAL-CAD): A Randomized Superiority Trial.

    Science.gov (United States)

    Taguchi, Isao; Iimuro, Satoshi; Iwata, Hiroshi; Takashima, Hiroaki; Abe, Mitsuru; Amiya, Eisuke; Ogawa, Takanori; Ozaki, Yukio; Sakuma, Ichiro; Nakagawa, Yoshihisa; Hibi, Kiyoshi; Hiro, Takafumi; Fukumoto, Yoshihiro; Hokimoto, Seiji; Miyauchi, Katsumi; Yamazaki, Tsutomu; Ito, Hiroshi; Otsuji, Yutaka; Kimura, Kazuo; Takahashi, Jun; Hirayama, Atsushi; Yokoi, Hiroyoshi; Kitagawa, Kazuo; Urabe, Takao; Okada, Yasushi; Terayama, Yasuo; Toyoda, Kazunori; Nagao, Takehiko; Matsumoto, Masayasu; Ohashi, Yasuo; Kaneko, Tetsuji; Fujita, Retsu; Ohtsu, Hiroshi; Ogawa, Hisao; Daida, Hiroyuki; Shimokawa, Hiroaki; Saito, Yasushi; Kimura, Takeshi; Inoue, Teruo; Matsuzaki, Masunori; Nagai, Ryozo

    2018-05-08

    Current guidelines call for high-intensity statin therapy in patients with cardiovascular disease on the basis of several previous "more versus less statins" trials. However, no clear evidence for more versus less statins has been established in an Asian population. In this prospective, multicenter, randomized, open-label, blinded end point study, 13 054 Japanese patients with stable coronary artery disease who achieved low-density lipoprotein cholesterol (LDL-C) fashion to high-dose (pitavastatin 4 mg/d; n=6526) or low-dose (pitavastatin 1 mg/d; n=6528) statin therapy. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, or unstable angina requiring emergency hospitalization. The secondary composite end point was a composite of the primary end point and clinically indicated coronary revascularization excluding target-lesion revascularization at sites of prior percutaneous coronary intervention. The mean age of the study population was 68 years, and 83% were male. The mean LDL-C level before enrollment was 93 mg/dL with 91% of patients taking statins. The baseline LDL-C level after the run-in period on pitavastatin 1 mg/d was 87.7 and 88.1 mg/dL in the high-dose and low-dose groups, respectively. During the entire course of follow-up, LDL-C in the high-dose group was lower by 14.7 mg/dL than in the low-dose group ( P Japanese patients with stable coronary artery disease. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01042730. © 2018 The Authors.

  14. Relative Bioavailability of Fixed-Dose Combinations of Tamsulosin and Dutasteride: Results From 2 Randomized Trials in Healthy Male Volunteers.

    Science.gov (United States)

    Burns, Olivia; Zhu, John; Manyak, Michael J; Ravindranath, Ramiya; Koosha, Fariba; Haque, Nazneen; Chung, Sally

    2018-05-01

    The relative bioavailabilities of dutasteride/tamsulosin hydrochloride 0.5 mg/0.2 mg fixed-dose combination (FDC) capsules compared with coadministered reference products (1 dutasteride 0.5-mg capsule [Avodart ® ] + 1 tamsulosin hydrochloride 0.2-mg orally disintegrating tablet [Harnal D ® ]) were investigated in 2 clinical trials under fasted and fed conditions (ClinicalTrials.gov NCT02184585 and NCT02509104). Both trials were open-label, randomized, single-dose, crossover studies in healthy male adults aged 18-65 years. Trial 1 evaluated 2 formulations (FDC1 and FDC2), and trial 2 evaluated a third formulation (FDC3). The primary end points were dutasteride area under the concentration-time curve from time 0 to t (AUC (0-t) ) and peak plasma concentration (C max ) and tamsulosin AUC (0-∞) , AUC (0-t) , and C max . The formulations were considered to be bioequivalent if the 90%CIs for the geometric mean ratios for each end point were within the range of 0.80-1.25. For FDC1 in trial 1, bioequivalence criteria were not met for dutasteride C max or AUC in the fasted state or for tamsulosin C max in the fasted or fed states. For FDC2 in trial 1, all bioequivalence criteria were met except for tamsulosin C max in the fasted state. For FDC3 in trial 2, bioequivalence criteria were met for all dutasteride and tamsulosin end points in both the fed and fasted states. Safety profiles were similar for all FDC formulations and combination treatments. © 2017, The American College of Clinical Pharmacology.

  15. High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

    International Nuclear Information System (INIS)

    Ghadjar, Pirus; Bojaxhiu, Beat; Simcock, Mathew; Terribilini, Dario; Isaak, Bernhard; Gut, Philipp; Wolfensberger, Patrick; Brömme, Jens O.; Geretschläger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M.

    2012-01-01

    Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3–23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

  16. High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ghadjar, Pirus, E-mail: pirus.ghadjar@insel.ch [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Bojaxhiu, Beat [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Simcock, Mathew [Swiss Group for Clinical Cancer Research Coordinating Center, Bern (Switzerland); Terribilini, Dario; Isaak, Bernhard [Division of Medical Radiation Physics, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Gut, Philipp; Wolfensberger, Patrick; Broemme, Jens O.; Geretschlaeger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M. [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland)

    2012-07-15

    Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3-23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

  17. Epidemiology of soccer-related injuries among male high school ...

    African Journals Online (AJOL)

    Soccer in Rwandan high schools can expose players to the risk of injury warranting prevention programmes. The aim of this study was to determine the type, causes, severity and management of injuries among high school soccer players in Rwanda, in order to obtain baseline data for injury prevention programmes.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  19. Dose optimization of intra-operative high dose rate interstitial brachytherapy implants for soft tissue sarcoma

    Directory of Open Access Journals (Sweden)

    Jamema Swamidas

    2009-01-01

    Full Text Available Objective : A three dimensional (3D image-based dosimetric study to quantitatively compare geometric vs. dose-point optimization in combination with graphical optimization for interstitial brachytherapy of soft tissue sarcoma (STS. Materials and Methods : Fifteen consecutive STS patients, treated with intra-operative, interstitial Brachytherapy, were enrolled in this dosimetric study. Treatment plans were generated using dose points situated at the "central plane between the catheters", "between the catheters throughout the implanted volume", at "distances perpendicular to the implant axis" and "on the surface of the target volume" Geometrically optimized plans had dose points defined between the catheters, while dose-point optimized plans had dose points defined at a plane perpendicular to the implant axis and on the target surface. Each plan was graphically optimized and compared using dose volume indices. Results : Target coverage was suboptimal with coverage index (CI = 0.67 when dose points were defined at the central plane while it was superior when the dose points were defined at the target surface (CI=0.93. The coverage of graphically optimized plans (GrO was similar to non-GrO with dose points defined on surface or perpendicular to the implant axis. A similar pattern was noticed with conformity index (0.61 vs. 0.82. GrO were more conformal and less homogeneous compared to non-GrO. Sum index was superior for dose points defined on the surface of the target and relatively inferior for plans with dose points at other locations (1.35 vs. 1.27. Conclusions : Optimization with dose points defined away from the implant plane and on target results in superior target coverage with optimal values of other indices. GrO offer better target coverage for implants with non-uniform geometry and target volume.

  20. Space and place in researching male early high school leaving in ...

    African Journals Online (AJOL)

    question the school systems' organisational components (Coleman, 1988), curriculum .... 2001:379) because of the value placed on a high-school certificate. Early school ..... Male early high school leaving in Orange Farm Township: A hidden.

  1. Shelf-stable food through high dose irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Placek, V. E-mail: pla@ujv.cz; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M

    2004-10-01

    Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO{sub x}-containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested.

  2. High-dose processing and application to Korean space foods

    Energy Technology Data Exchange (ETDEWEB)

    Song, Beom-Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Choi, Jong-il [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Jae-Hun [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Korea Astronaut Project Division, Korea Aerospace Research Institute, Daejeon 305-333 (Korea, Republic of); Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kang, Sang-Wook; Choi, Gi-Hyuk [Korea Astronaut Project Division, Korea Aerospace Research Institute, Daejeon 305-333 (Korea, Republic of); Lee, Ju-Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Nutrition bar, Ramen (ready-to-cook noodle), and two Korean traditional foods (Kimchi, fermented vegetable; Sujeonggwa, cinnamon beverage) have been developed as space foods using high-dose gamma irradiation. Addition of calcium lactate and vitamin C, a mild heating, deep-freezing, and gamma irradiation at 25 kGy were conducted to prepare Kimchi as a ready-to-eat space food. Sterilization of Space Kimchi (SK) was confirmed by a microbiological test. The hardness of the Space Kimchi was lower than the untreated Kimchi (CON), but higher than the irradiated only Kimchi. Sensory attributes of the SK were similar to CON, and maintained during preservation at 35 {sup o}C for 30 days. The optimal doses for eliminating the contaminated microbes and maintaining the qualities of the Nutrition bars, Ramen, and Sujeonggwa were determined at 15, 10 and 6 kGy, respectively. All the Korean space food were certificated for use in space flight conditions of 30 days by the Russian Institute for Biomedical Problems.

  3. Shelf-stable food through high dose irradiation

    International Nuclear Information System (INIS)

    Placek, V.; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M.

    2004-01-01

    Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO x -containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested

  4. High dose rate brachytherapy for the palliation of malignant dysphagia

    International Nuclear Information System (INIS)

    Homs, Marjolein Y.V.; Eijkenboom, Wilhelmina M.H.; Coen, Veronique L.M.A.; Haringsma, Jelle; Blankenstein, Mark van; Kuipers, Ernst J.; Siersema, Peter D.

    2003-01-01

    Background and purpose: High dose rate (HDR) brachytherapy is a commonly used palliative treatment for esophageal carcinoma. We evaluated the outcome of HDR brachytherapy in patients with malignant dysphagia. Material and methods: A retrospective analysis over a 10-year period was performed of 149 patients treated with HDR brachytherapy, administered in one or two sessions, at a median dose of 15 Gy. Patients were evaluated for functional outcome, complications, recurrent dysphagia, and survival. Results: At 6 weeks after HDR brachytherapy, dysphagia scores had improved from a median of 3 to 2 (n=104; P<0.001), however, dysphagia had not improved in 51 (49%) patients. Procedure-related complications occurred in seven (5%) patients. Late complications, including fistula formation or bleeding, occurred in 11 (7%) patients. Twelve (8%) patients experienced minor retrosternal pain. Median survival of the patients was 160 days with a 1-year survival rate of 15%. Procedure-related mortality was 2%. At follow-up, 55 (37%) patients experienced recurrent dysphagia. In 34 (23%) patients a metal stent was placed to relieve persistent or recurrent dysphagia. Conclusion: HDR brachytherapy is a moderately effective treatment for the palliation of malignant dysphagia. The incidence of early major complications is low, however, persistent and recurrent dysphagia occur frequently, and require often additional treatment

  5. High-dose processing and application to Korean space foods

    Science.gov (United States)

    Song, Beom-Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Kang, Sang-Wook; Choi, Gi-Hyuk; Lee, Ju-Woon

    2009-07-01

    Nutrition bar, Ramen (ready-to-cook noodle), and two Korean traditional foods ( Kimchi, fermented vegetable; Sujeonggwa, cinnamon beverage) have been developed as space foods using high-dose gamma irradiation. Addition of calcium lactate and vitamin C, a mild heating, deep-freezing, and gamma irradiation at 25 kGy were conducted to prepare Kimchi as a ready-to-eat space food. Sterilization of Space Kimchi (SK) was confirmed by a microbiological test. The hardness of the Space Kimchi was lower than the untreated Kimchi (CON), but higher than the irradiated only Kimchi. Sensory attributes of the SK were similar to CON, and maintained during preservation at 35 °C for 30 days. The optimal doses for eliminating the contaminated microbes and maintaining the qualities of the Nutrition bars, Ramen, and Sujeonggwa were determined at 15, 10 and 6 kGy, respectively. All the Korean space food were certificated for use in space flight conditions of 30 days by the Russian Institute for Biomedical Problems.

  6. Tungsten and carbon surface change under high dose plasma exposure

    International Nuclear Information System (INIS)

    Martynenko, Y.V.; Khripunov, B.I.; Petrov, V.B.

    2009-01-01

    Study of surface composition dynamics has been made on the LENTA linear plasma simulator. Experiments have been made on tungsten and carbon materials subjected to steady-state plasma exposure. The achieved ion doses on the surface were 10 21 ion cm -2 . WL 10 tungsten containing 1% of La2O3 oxide and titanium-doped graphite RG-T were studied. The following experimental conditions were varied in these experiments: energy of ions, surface temperature, working gas. Irradiations of tungsten WL 10 were executed in deuterium plasma at low ion energies (about 20 eV) and at 200 eV for temperatures below 340 K. Graphite RG-T was exposed at 1300 K. Elevated surface temperature (about 1050K) was also characteristic of experiments on tungsten sample under nitrogen plasma impact (simulated inter-ELMs condition). Surface microstructure modification has been observed and surface composition changes were found on the materials showing influence of high dose plasma irradiations on element redistribution in the near surface layers. (author)

  7. High-dose processing and application to Korean space foods

    International Nuclear Information System (INIS)

    Song, Beom-Seok; Park, Jin-Gyu; Park, Jae-Nam; Han, In-Jun; Choi, Jong-il; Kim, Jae-Hun; Byun, Myung-Woo; Kang, Sang-Wook; Choi, Gi-Hyuk; Lee, Ju-Woon

    2009-01-01

    Nutrition bar, Ramen (ready-to-cook noodle), and two Korean traditional foods (Kimchi, fermented vegetable; Sujeonggwa, cinnamon beverage) have been developed as space foods using high-dose gamma irradiation. Addition of calcium lactate and vitamin C, a mild heating, deep-freezing, and gamma irradiation at 25 kGy were conducted to prepare Kimchi as a ready-to-eat space food. Sterilization of Space Kimchi (SK) was confirmed by a microbiological test. The hardness of the Space Kimchi was lower than the untreated Kimchi (CON), but higher than the irradiated only Kimchi. Sensory attributes of the SK were similar to CON, and maintained during preservation at 35 o C for 30 days. The optimal doses for eliminating the contaminated microbes and maintaining the qualities of the Nutrition bars, Ramen, and Sujeonggwa were determined at 15, 10 and 6 kGy, respectively. All the Korean space food were certificated for use in space flight conditions of 30 days by the Russian Institute for Biomedical Problems.

  8. Concept and computation of radiation dose at high energies

    International Nuclear Information System (INIS)

    Sarkar, P.K.

    2010-01-01

    Computational dosimetry, a subdiscipline of computational physics devoted to radiation metrology, is determination of absorbed dose and other dose related quantities by numbers. Computations are done separately both for external and internal dosimetry. The methodology used in external beam dosimetry is necessarily a combination of experimental radiation dosimetry and theoretical dose computation since it is not feasible to plan any physical dose measurements from inside a living human body

  9. Gonad doses for male patients from stomach examination and oral cholegraphy using the X-ray image intensifying technique and television fluoroscopy

    International Nuclear Information System (INIS)

    Steinbach, W.; Richter, K.; Koenig, W.; Menzel, B.; Reisinger, W.; Uhlich, F.

    1979-01-01

    The gonad dose was measured for male patients undergoing stomach examinations and oral cholegraphy by means of a diagnostic twelve pulse generator (TuR D 1500) and an X-ray apparatus 'Diagnost 100' (Philips-Mueller). In a small group of patients the gonad dose was ascertained per exposure to a 70 mm single spot film, to a 24 cm x 30 cm full size radiograph, and per minute of exposure to image intensifier fluoroscopy. The total gonad dose in both the diagnostic techniques was determined seperately in larger groups of patients. In stomach examination large size radiography led to a gonad dose 20 times higher than that obtained with the spot film technique, while exposure from cholegraphy was 10 times higher. The gonad dose per exposure of a single spot film was about 0.5 mrad. In examinations of the stomach the gonad dose from one minute fluroscopy was 18 times higher than the doses determined for a single spot film, and in cholegraphy it was 10 times higher. Supposing mean values of the number of radiographs and of the fluoroscopy time according to the conditions applied, the gonad dose in stomach examination from the film-screen technique is about twice that from the television image-intensifying technique. By comparison, oral cholegraphy exclusively performed by large-size radiography yielded about the same gonad dose as the spot film television technique. Total dose values determined separately confirmed these evaluations. (author)

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

    Science.gov (United States)

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

    2007-01-01

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

  11. Surface sputtering in high-dose Fe ion implanted Si

    International Nuclear Information System (INIS)

    Ishimaru, Manabu

    2007-01-01

    Microstructures and elemental distributions in high-dose Fe ion implanted Si were characterized by means of transmission electron microscopy and Rutherford backscattering spectroscopy. Single crystalline Si(0 0 1) substrates were implanted at 350 deg. C with 120 keV Fe ions to fluences ranging from 0.1 x 10 17 to 4.0 x 10 17 /cm 2 . Extensive damage induced by ion implantation was observed inside the substrate below 1.0 x 10 17 /cm 2 , while a continuous iron silicide layer was formed at 4.0 x 10 17 /cm 2 . It was found that the spatial distribution of Fe projectiles drastically changes at the fluence between 1.0 x 10 17 and 4.0 x 10 17 /cm 2 due to surface sputtering during implantation

  12. High-dose erythropoietin in patients with progressive multiple sclerosis

    DEFF Research Database (Denmark)

    Schreiber, Karen; Magyari, Melinda; Sellebjerg, Finn

    2017-01-01

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

  13. Safety handling manual for high dose rate remote afterloading system

    International Nuclear Information System (INIS)

    1999-01-01

    This manual is mainly for safety handling of 192 Ir-RALS (remote afterloading system) of high dose rate and followings were presented: Procedure and document format for the RALS therapy and for handling of its radiation source with the purpose of prevention of human errors and unexpected accidents, Procedure for preventing errors occurring in the treatment schedule and operation, and Procedure and format necessary for newly introducing the system into a facility. Consistency was intended in the description with the quality assurance guideline for therapy with small sealed radiation sources made by JASTRO (Japan Society for Therapeutic Radiology and Oncology). Use of the old type 60 Co-RALS was pointed out to be a serious problem remained and its safety handling procedure was also presented. (K.H.)

  14. Calibration of {sup 192}Ir high dose rate brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, M H [Instituto de Radioprotecao e Dozimetria, Rio de Jainero (Brazil); Almeida, C.E. de [Laboratorio de Ciencias Radiologicas, UERL, Rio de Janeiro (Brazil); Sibata, C H [Roswell Park Cancer Inst., Buffalo, NY (United States)

    1996-08-01

    A method for calibration of high dose rate sources used in afterloading brachytherapy systems is described. The calibration for {sup 192}Ir is determined by interpolating {sup 60}Co gamma-rays and 250 kV x-rays calibration factors. All measurements were done using the same build up caps as described by Goetsch et al and recommended by AAPM. The attenuation correction factors were determined to be 0.9903, 0.9928 and 0.9993 for {sup 192}Ir, {sup 60}Co and 250 kV x-ray, respectively. A wall + cap thickness of 0.421 g.cm{sup -2} is recommended for all measurements to ensure electronic equilibrium for {sup 60}Co and {sup 192}Ir gamma-ray beams. A mathematical formalism is described for determination of (N{sub x}){sub Ir}. (author). 5 refs, 1 fig.

  15. 192Ir high dose rate (HDR) interstitial brain implant: optimisation

    International Nuclear Information System (INIS)

    Tyagi, Anuj; Singh, Dinesh; Chitra, S.; Gupta, J.P.

    2001-01-01

    The new modality of stepping source dosimetry system (SSDs) illustrates a remarkable improvement in attaining the uniform and homogeneous dose distribution within the target volume. The technique enables the physicist to correct for a certain amount of misplacement or curvature of implant geometry. The short course of brachytherapy provides good palliation in terms of functional improvements with low and acceptable toxicity in high-grade glioma. With continual refinements of the technique, brachytherapy performed by a skilled brachytherapy team offers an opportunity to improve patient survival and quality of life. Since 1997, micro selectron HDR 192 Ir treatments are done including gynecological, oesophageal, breast, surface mould, soft tissue sarcoma (STS) and brain in our hospital. In this paper, procedure of interstitial brain implant in glioma as implant technique, simulation and treatment planning will be discussed

  16. Semisterility of the first male progeny of female rats given a fractionated x ray dose of 800 R with administration of cysteamine and cystamine

    Energy Technology Data Exchange (ETDEWEB)

    Baev, I; Bairakova, A

    1975-01-01

    A total of 107 male Wistar rats were obtained six months after the fractional irradiation of females at a total x ray dose of 800 R (40 R per day for 20 days). Part of the females were irradiated without protection, and the rest received 5 mg cysteamine and 20 mg cystamine per rat each day before irradiation. The irradiated females were crossed with intact males. Fifteen males obtained from unirradiated parents served as controls. Males obtained from irradiated mothers and the control males were each housed with 7 intact females on attaining reproductive age. The females were killed on the 18th day after fertilization, and the living and dead embryos and the yellow bodies in each female were determined. The embryonic lethality in the male progeny whose mothers were irradiated with a fractionated dose of 800 R was 11 percent preimplantation with 9 percent postimplantation for a total of 19 percent for irradiated mothers given no radioprotective agent compared with 7 percent preimplantation with 5.5 percent postimplantation for a total of 12.5 percent in the control rats. For the cystamine-protected mothers the corresponding embryonic lethalities were 16.1 percent preimplantation with 10.5 percent postimplantation for a total of 26.6 percent, and for the cysteamine protected mothers, 14.3 percent preimplantation with 14.2 percent postimplantation for a total of 28.5 percent. Abouthalf of the males from the first generation of irradiated females showed a lowered fertility. 10 refs.

  17. High dose rate brachytherapy for superficial cancer of the esophagus

    International Nuclear Information System (INIS)

    Maingon, Philippe; D'Hombres, Anne; Truc, Gilles; Barillot, Isabelle; Michiels, Christophe; Bedenne, Laurent; Horiot, Jean Claude

    2000-01-01

    Purpose: We analyzed our experience with external radiotherapy, combined modality treatment, or HDR brachytherapy alone to limited esophageal cancers. Methods and Materials: From 1991 to 1996, 25 patients with limited superficial esophagus carcinomas were treated by high dose rate brachytherapy. The mean age was 63 years (43-86 years). Five patients showed superficial local recurrence after external radiotherapy. Eleven patients without invasion of the basal membrane were staged as Tis. Fourteen patients with tumors involving the submucosa without spreading to the muscle were staged as T1. Treatment consisted of HDR brachytherapy alone in 13 patients, external radiotherapy and brachytherapy in 8 cases, and concomitant chemo- and radiotherapy in 4 cases. External beam radiation was administered to a total dose of 50 Gy using 2 Gy daily fractions in 5 weeks. In cases of HDR brachytherapy alone (13 patients), 6 applications were performed once a week. Results: The mean follow-up is 31 months (range 24-96 months). Twelve patients received 2 applications and 13 patients received 6 applications. Twelve patients experienced a failure (48%), 11/12 located in the esophagus, all of them in the treated volume. One patient presented an isolated distant metastasis. In the patients treated for superficial recurrence, 4/5 were locally controlled (80%) by brachytherapy alone. After brachytherapy alone, 8/13 patients were controlled (61%). The mean disease-free survival is 14 months (1-36 months). Overall survival is 76% at 1 year, 37% at 2 years, and 14% at 3 years. Overall survival for Tis patients is 24% vs. 20% for T1 (p 0.83). Overall survival for patients treated by HDR brachytherapy alone is 43%. One patient presented with a fistula with local failure after external radiotherapy and brachytherapy. Four stenosis were registered, two were diagnosed on barium swallowing without symptoms, and two required dilatations. Conclusion: High dose rate brachytherapy permits the treating

  18. "Time sequential high dose of Cytarabine in acute myelocytic leukemia "

    Directory of Open Access Journals (Sweden)

    Ghavamzadeh A

    2003-05-01

    Full Text Available Given preliminary evidence of timed, sequential chemotherapy of high dose cytosine arabinoside the current study was initiated to assess the side effects and efficacy of this regimen in patients with newly acute myelocytic leukemia (AML. Nineteen adults who referred to Hematology-Oncology and Bone Marrow Transplantation (BMT research center of Tehran University of Medical Sciences were enrolled in a trial from Aug 1999 to Nov 2000. All patients had a Karnofski classification above 60%. At this time induction therapy consisted of daunorubicin or idarubicin given at a dose of 60 mg/m² and 12 mg/m² IV respectively on days 1-3, and cytarabine (Ara-C 100 mg/m² intravenously by continuous infusion on days 1-7, followed by Ara-C 1000 mg/m² given on day 8-10 every 12 hours by IV infusion. Consolidation therapy started after 35th day. Of 19 fully evaluable patients, 10 patients achieved a complete remission, whereas 36.6% patients succumbed to death due to regeneration failure. The clinical data show that the overall survival rate from diagnosis 55.5% (95% CI, 30.8-78.5 at 6 months for the entire cohort of the patients. Disease free survival is also 50% (95% CI, 26-74. Mean duration of death due to treatment was 20 days (range 17-29 after beginning the regimen. Presenting WBC counts, French-American-British (FAB classification, sex and age were not useful prognostic variables. Fever, diarrhea, nausea and vomiting and GI hemorrhage were seen in 19, 6, 4, 7 patients respectively. It seems the 3+7+3 regimen is a promising approach for the AML patients regarding to high complete remission rate, but more supportive care should be considered. Furthermore any, benefit in long-term outcome can’t be determined regardless to the choice of post remission therapy (e.g., GCSF, appropriate antibiotics and etc.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  1. Teflon pastille use in high dose dosimetry; Utilizacao de pastilhas de teflon em dosimetria de doses altas

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Maria Ines [Associacao Educacional Nove de Julho (UNINOVE), Sao Paulo, SP (Brazil); Caldas, Linda V.E., E-mail: miteixeira@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    This paper study the Teflon, which is used as aglomerant in the confection of dosimetric pastilles, for the viabilization of this material as high dose dosimeter. This paper used the OSL technique for the characterization of dosimetric properties of Teflon. The doses-response curve has been obtained for {sup 60}Co radiation between 100 Gy and 50 kGy, and the OSL answer reproducibility. The preliminary results shown that the Teflon is a material which can be used for high dose dosimetry

  2. Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

    International Nuclear Information System (INIS)

    Braby, L. A.; Reece, W. D.; Hsu, W. H.

    2003-01-01

    Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation experiments. We have also developed 4.3 mm diameter ion chambers with both tissue equivalent and carbon walls for the purpose of measuring dose mean lineal energy due to all radiations and due to all radiations except neutrons, respectively. By adjusting the gas pressure in the ion chamber, it can be made to simulate tissue volumes from a few nanometers to a few millimeters in diameter. The charge is integrated for 0.1 seconds, and the resulting pulse height is recorded by a multi channel analyzer. The system has been used in a variety of photon and neutron radiation fields, and measured values of dose and dose mean lineal energy are consistent with values extrapolated from measurements made by other techniques at much lower dose rates. It is expected that this technique will prove to be much more reliable than extrapolations from measurements made at low dose rates because these low dose rate exposures generally do not accurately reproduce the attenuation and

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

    Directory of Open Access Journals (Sweden)

    Parvaneh Karim-Zadeh

    2003-12-01

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

  4. Development of Real-Time Measurement of Effective Dose for High Dose Rate Neutron Fields

    CERN Document Server

    Braby, L A; Reece, W D

    2003-01-01

    Studies of the effects of low doses of ionizing radiation require sources of radiation which are well characterized in terms of the dose and the quality of the radiation. One of the best measures of the quality of neutron irradiation is the dose mean lineal energy. At very low dose rates this can be determined by measuring individual energy deposition events, and calculating the dose mean of the event size. However, at the dose rates that are normally required for biology experiments, the individual events can not be separated by radiation detectors. However, the total energy deposited in a specified time interval can be measured. This total energy has a random variation which depends on the size of the individual events, so the dose mean lineal energy can be calculated from the variance of repeated measurements of the energy deposited in a fixed time. We have developed a specialized charge integration circuit for the measurement of the charge produced in a small ion chamber in typical neutron irradiation exp...

  5. Effect of inulin supplementation in male mice fed with high fat diet on ...

    African Journals Online (AJOL)

    Purpose: To evaluate the preventive and therapeutic effects of inulin supplementation in Naval Medical Research Institute (NMRI) male mice fed with high fat diet. Methods: NMRI male mice (n = 36) were divided into three groups. Control (C1), obese (O1) and experimental mice (E1) were fed during 8 weeks as follows: C1 ...

  6. Novel Use of the Contura for High Dose Rate Cranial Brachytherapy

    International Nuclear Information System (INIS)

    Scanderbeg, Daniel J.; Alksne, John F.; Lawson, Joshua D.; Murphy, Kevin T.

    2011-01-01

    A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator.

  7. Novel use of the Contura for high dose rate cranial brachytherapy.

    Science.gov (United States)

    Scanderbeg, Daniel J; Alksne, John F; Lawson, Joshua D; Murphy, Kevin T

    2011-01-01

    A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  8. Urethral stricture following high dose rate brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Sullivan, Lisa; Williams, Scott G.; Tai, Keen Hun; Foroudi, Farshad; Cleeve, L.; Duchesne, Gillian M.

    2009-01-01

    Purpose: To evaluate the incidence, timing, nature and outcome of urethral strictures following high dose rate brachytherapy (HDRB) for prostate carcinoma. Methods and materials: Data from 474 patients with clinically localised prostate cancer treated with HDRB were analysed. Ninety percent received HDRB as a boost to external beam radiotherapy (HDRBB) and the remainder as monotherapy (HDRBM). Urethral strictures were graded according to the Common Terminology Criteria for Adverse Events v3.0. Results: At a median follow-up of 41 months, 38 patients (8%) were diagnosed with a urethral stricture (6-year actuarial risk 12%). Stricture location was bulbo-membranous (BM) urethra in 92.1%. The overall actuarial rate of grade 2 or more BM urethral stricture was estimated at 10.8% (95% CI 7.0-14.9%), with a median time to diagnosis of 22 months (range 10-68 months). All strictures were initially managed with either dilatation (n = 15) or optical urethrotomy (n = 20). Second line therapy was required in 17 cases (49%), third line in three cases (9%) and 1 patient open urethroplasty (grade 3 toxicity). Predictive factors on multivariate analysis were prior trans-urethral resection of prostate (hazard ratio (HR) 2.81, 95% CI 1.15-6.85, p = 0.023); hypertension (HR 2.83, 95% CI 1.37-5.85, p = 0.005); and dose per fraction used in HDR (HR for 1 Gy increase per fraction 1.33, 95% CI 1.08-1.64, p = 0.008). Conclusions: BM urethral strictures are the most common late grade 2 or more urinary toxicity following HDR brachytherapy for prostate cancer. Most are manageable with minimally invasive procedures. Both clinical and dosimetric factors appear to influence the risk of stricture formation.

  9. High doses of the histone deacetylase inhibitor sodium butyrate trigger a stress-like response.

    Science.gov (United States)

    Gagliano, Humberto; Delgado-Morales, Raul; Sanz-Garcia, Ancor; Armario, Antonio

    2014-04-01

    The hypothalamic-pituitary-adrenal (HPA) axis is activated by a wide range of stimuli, including drugs. Here we report that in male rats, a dose of sodium butyrate (NaBu) that is typically used to inhibit histone deacetylation (1200 mg/kg) increased the peripheral levels of HPA hormones and glucose. In a further experiment, we compared the effects of two different doses of NaBu (200 and 1200 mg/kg) and equimolar saline solutions on peripheral neuroendocrine markers and brain c-Fos expression to demonstrate a specific stress-like effect of NaBu that is not related to hypertonicity and to localise putatively involved brain areas. Only the high dose of NaBu increased the plasma levels of stress markers. The equimolar (hypertonic) saline solution also activated the HPA axis and the c-Fos expression in the paraventricular nucleus of the hypothalamus (PVN), a key area for the control of the HPA axis, but the effects were of a lower magnitude than those of NaBu. Regarding other brain areas, group differences in c-Fos expression were not observed in the medial prefrontal cortex or the medial amygdala, but they were observed in the central amygdala and the lateral ventral septum. However, only the latter area of the NaBu group showed enhanced c-Fos expression that was significantly higher than that after hypertonic saline. The present data indicate that high doses of NaBu appear to act as a pharmacological stressor, and this fact should be taken into account when using this drug to study the role of epigenetic processes in learning and emotional behaviour. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Dosing algorithm to target a predefined AUC in patients with primary central nervous system lymphoma receiving high dose methotrexate.

    Science.gov (United States)

    Joerger, Markus; Ferreri, Andrés J M; Krähenbühl, Stephan; Schellens, Jan H M; Cerny, Thomas; Zucca, Emanuele; Huitema, Alwin D R

    2012-02-01

    There is no consensus regarding optimal dosing of high dose methotrexate (HDMTX) in patients with primary CNS lymphoma. Our aim was to develop a convenient dosing algorithm to target AUC(MTX) in the range between 1000 and 1100 µmol l(-1) h. A population covariate model from a pooled dataset of 131 patients receiving HDMTX was used to simulate concentration-time curves of 10,000 patients and test the efficacy of a dosing algorithm based on 24 h MTX plasma concentrations to target the prespecified AUC(MTX) . These data simulations included interindividual, interoccasion and residual unidentified variability. Patients received a total of four simulated cycles of HDMTX and adjusted MTX dosages were given for cycles two to four. The dosing algorithm proposes MTX dose adaptations ranging from +75% in patients with MTX C(24) 12 µmol l(-1). The proposed dosing algorithm resulted in a marked improvement of the proportion of patients within the AUC(MTX) target between 1000 and 1100 µmol l(-1) h (11% with standard MTX dose, 35% with the adjusted dose) and a marked reduction of the interindividual variability of MTX exposure. A simple and practical dosing algorithm for HDMTX has been developed based on MTX 24 h plasma concentrations, and its potential efficacy in improving the proportion of patients within a prespecified target AUC(MTX) and reducing the interindividual variability of MTX exposure has been shown by data simulations. The clinical benefit of this dosing algorithm should be assessed in patients with primary central nervous system lymphoma (PCNSL). © 2011 The Authors. British Journal of Clinical Pharmacology © 2011 The British Pharmacological Society.

  11. 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.)

  12. Quality of life in a cohort of high-dose benzodiazepine dependent patients.

    Science.gov (United States)

    Lugoboni, Fabio; Mirijello, Antonio; Faccini, Marco; Casari, Rebecca; Cossari, Anthony; Musi, Gessica; Bissoli, Giorgia; Quaglio, Gianluca; Addolorato, Giovanni

    2014-09-01

    Benzodiazepines (BZD) are among the most widely prescribed drugs in developed countries. Since BZD can produce tolerance and dependence even in a short time, their use is recommended for a very limited time. However, these recommendations have been largely disregarded. The chronic use of BZD causes a number of serious side effects, i.e., cognitive impairment, falls, traffic accidents, dependence and tolerance. The aim of the present study was to evaluate quality of life (QoL) in a cohort of 62 consecutive high-dose BZD-dependent patients seeking a BZD detoxification. Patients seeking BZD detoxification were evaluated using the General Health Questionnaire (GHQ-12) and the short form-36 questionnaire (SF-36). Patients showed a significant reduction of QoL as measured by either SF-36 or GHQ-12. In particular, the greater impairment was observed in the items exploring physical and emotional status. Physical functioning was the item more influenced by the length of BZD abuse. Female patients showed a greater reduction of QoL compared to male, at least in some of the explored items. Social functioning scores were greatly reduced. The present study shows for the first time that high-doses BZD dependent patients have a reduced QoL and a reduced social functioning, along with high levels of psychological distress. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Taeko; Morishima, Hiroshige [Kinki Univ., Atomic Energy Research Institute, Osaka (Japan); Tatsumi, Kusuo [Kinki Univ., Life Science Research Institute, Osaka (Japan); Nakai, Sayaka; Sugahara, Tsutomu [Health Research Foundation, Kyoto (Japan); Yuan Yongling [Labor Hygiene Institute of Hunan Prov. (China); Wei Luxin [Laboratory of Industorial Hygiene, Ministry of Health (China)

    2001-01-01

    As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: (1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. (2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

  14. Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

    International Nuclear Information System (INIS)

    Koga, Taeko; Morishima, Hiroshige; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

    2001-01-01

    As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: 1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. 2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

  15. High-dose fasudil preserves postconditioning against myocardial infarction under hyperglycemia in rats: role of mitochondrial KATP channels

    Directory of Open Access Journals (Sweden)

    Ichinomiya Taiga

    2012-03-01

    Full Text Available Abstract Background The current study was carried out to determine whether fasudil hydrochloride (fasudil, a Rho-kinase inhibitor, has myocardial postconditioning (PostC activity under hyperglycemia as well as normoglycemia, and if so, whether the effects could be mediated by mitochondrial ATP-sensitive potassium (m-KATP channels. Methods Male Sprague-Dawley rats were anesthetized with sodium pentobarbital. After opening the chest, all rats underwent 30-min coronary artery occlusion followed by 2-h reperfusion. The rats received low-dose (0.15 mg/kg or high-dose (0.5 mg/kg fasudil or diazoxide, an m-KATP channel opener, at 10 mg/kg, just before reperfusion under normoglycemic or hyperglycemic conditions. In another group, rats received 5-hydroxydecanoic acid (5HD, an m-KATP channel blocker, at 10 mg/kg, before high-dose fasudil. Myocardial infarct size was expressed as a percentage of area at risk (AAR. Results Under normoglycemia, low-dose and high-dose fasudil and diazoxide reduced myocardial infarct size (23 ± 8%, 21 ± 9% and 21 ± 10% of AAR, respectively compared with that in the control (42 ± 7%. Under hyperglycemia, low-dose fasudil (40 ± 11% and diazoxide (44 ± 14% could not exert this beneficial effect, but high-dose fasudil reduced myocardial infarct size in the same manner as under normoglycemia (21 ± 13%. 5HD prevented fasudil-induced reduction of myocardial infarct size (42 ± 13%. Conclusion Fasudil induces PostC against myocardial infarction via activation of m-KATP channels in the rat. Although hyperglycemia attenuates the PostC, high-dose fasudil can restore cardioprotection.

  16. Induction by X-rays of chromosome aberrations in male guinea-pigs and golden hamsters. 4. Dose-response for spermatogonia treated with fractionated doses

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, M F; Cox, B D [Medical Research Council, Harwell (UK). Radiobiological Research Unit

    1975-10-01

    The effect of dose fractionation on the induction of translocations by 400 and 600 rad X-rays in spermatogonia of guinea-pigs and hamsters was investigated cytologically. Three types of fractionation were used, dividing the dose into (a) two equal fractions 24h apart, (b) two equal fractions 8 weeks apart, and (c) eight or twelve equal fractions of 50 rad, at intervals of one week. The two species responded similarly throughout, but gave lower translocation yields than the mouse. The effects of the first and third types of fractionation were similar to those described previously in the mouse, and suggested that a first radiation dose modifies the spermatogonial population so that its sensitivity to a dose 24h later is altered, and that repeated radiation doses result in development of resistance to translocation induction. After 8-week fractionation, the results suggested that in guinea-pigs and hamsters, the spermatogonial population had not returned to normal by 8 weeks after the first dose, whereas in the mouse, normal sensitivity had returned by this time. The results, reported previously, of single doses of X-rays suggest that the spermatogonial population consists of sub-populations differing in sensitivity to cell killing and genetic effects. The effects of fractionated doses in the mouse suggest that the sensitive and resistant types represent different phases of the samecell type rather than two distinct types of cell. In the guinea-pig and hamster, this question remains open.

  17. Comparative study of SOI/Si hybrid substrates fabricated using high-dose and low-dose oxygen implantation

    International Nuclear Information System (INIS)

    Dong Yemin; Chen Meng; Chen Jing; Wang Xiang; Wang Xi

    2004-01-01

    Hybrid substrates comprising both silicon-on-insulator (SOI) and bulk Si regions have been fabricated using the technique of patterned separation by implantation of oxygen (SIMOX) with high-dose (1.5 x 10 18 cm -2 ) and low-dose ((1.5-3.5) x 10 17 cm -2 ) oxygen ions, respectively. Cross-sectional transmission electron microscopy (XTEM) was employed to examine the microstructures of the resulting materials. Experimental results indicate that the SOI/Si hybrid substrate fabricated using high-dose SIMOX is of inferior quality with very large surface height step and heavily damaged transitions between the SOI and bulk regions. However, the quality of the SOI/Si hybrid substrate is enhanced dramatically by reducing the implant dose. The defect density in transitions is reduced considerably. Moreover, the expected surface height difference does not exist and the surface is exceptionally flat. The possible mechanisms responsible for the improvements in quality are discussed

  18. Dose-dependent high-resolution electron ptychography

    International Nuclear Information System (INIS)

    D'Alfonso, A. J.; Allen, L. J.; Sawada, H.; Kirkland, A. I.

    2016-01-01

    Recent reports of electron ptychography at atomic resolution have ushered in a new era of coherent diffractive imaging in the context of electron microscopy. We report and discuss electron ptychography under variable electron dose conditions, exploring the prospects of an approach which has considerable potential for imaging where low dose is needed

  19. Mutation process at low or high radiation doses

    International Nuclear Information System (INIS)

    Abrahamson, S.; Wisconsin Univ., Madison

    1976-01-01

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

  20. Effects of moderate-dose versus high-dose trimethoprim on serum creatinine and creatinine clearance and adverse reactions.

    OpenAIRE

    Naderer, O; Nafziger, A N; Bertino, J S

    1997-01-01

    The effects of a 10-day course of moderate-dose (10 mg/kg/day) or high-dose (20 mg/kg/day) trimethoprim therapy on serum creatinine, measured creatinine clearance, urinary creatinine excretion, and serum folate were studied in 20 healthy volunteers. Serum creatinine concentrations increased significantly during trimethoprim therapy, began to decrease near day 10, and returned to baseline during the washout phase at both dosage levels. At the same time, measured creatinine clearance and urine ...

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  2. 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

  3. A comparison of high-dose and low-dose tranexamic acid antifibrinolytic protocols for primary coronary artery bypass surgery

    Directory of Open Access Journals (Sweden)

    Stephen M McHugh

    2016-01-01

    Full Text Available Background and Aims: Tranexamic acid (TA is used for prophylactic antifibrinolysis in coronary artery bypass surgeries to reduce bleeding. We evaluated the efficacy of two different doses of TA for prophylactic antifibrinolysis in patients undergoing primary coronary artery bypass grafting (CABG surgery in this retrospective cohort study at a tertiary care referral centre. Methods: One-hundred eighty-four patients who underwent primary CABG with cardiopulmonary bypass (CPB via sternotomy between January 2009 and June 2011 were evaluated. Pre-operative patient characteristics, intraoperative data, post-operative bleeding, transfusions, organ dysfunction and 30-day mortality were compared between high-dose TA (30 mg/kg loading dose followed by infusion of 15 mg/kg/h until the end of surgery along with 2 mg/kg priming dose in the bypass circuit and low-dose TA (15 mg/kg loading dose followed by infusion of 6 mg/kg/h until the end of surgery along with 1 mg/kg priming dose in the bypass circuit groups. Univariate comparative analysis of all categorical and continuous variables was performed between the two groups by appropriate statistical tests. Linear and logistic regression analyses were performed to control for the effect of confounding on the outcome variables. Results: Chest tube output, perioperative transfusion of blood products and incidence of re-exploration for bleeding did not differ significantly (P> 0.05 between groups. Post-operative complications and 30-day mortality were comparable between the groups. The presence of cardiogenic shock and increased pre-operative creatinine were found to be associated with increased chest tube output on the post-operative day 2 by multivariable linear regression model. Conclusions: Low-dose TA protocol is as effective as high-dose protocol for antifibrinolysis in patients undergoing primary CABG with CPB.

  4. Split high-dose oral levothyroxine treatment as a successful therapy option in myxedema coma.

    Science.gov (United States)

    Charoensri, Suranut; Sriphrapradang, Chutintorn; Nimitphong, Hataikarn

    2017-10-01

    High-dose intravenous thyroxine (T4) is the preferable treatment for myxedema coma. We describe the clinical course of a 69-year-old man who presented with myxedema coma and received oral levothyroxine (LT4) therapy (1 mg) in a split dose. This suggests split high-dose oral LT4 as a therapeutic option in myxedema coma.

  5. SU-E-T-636: Investigation of Dose Variation in High Dose Radiation Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hyvarinen, M; Leventouri, T; Casey, C; Long, S [Florida Atlantic University, Boca Raton, FL (United States); Pella, S [South Florida Radiation Oncology and Florida Atlantic University, Boca Raton, FL (United States); Dumitru, N [University of Bucharest, Bucharest-magurele, Ilfov (Romania); Herrera, R [Louis Stokes VA Medical Center, Cleveland, OH (United States)

    2014-06-15

    Purpose: The purpose of this study is to revise most of the HDR types of treatments with their applicators and their localization challenges. Since every millimeter of misplacement counts the study will look into the necessity of increasing the immobilization for several types of applicators Methods: The study took over 136 plans generated by the treatment planning system (TPS) looking into the applicator's placement in regard to the organs at risk (OR) and simulated the three possible displacements at the hottest dose point on the critical organ for several accessories to evaluate the variation of the delivered dose at the point due to the displacement. Results: Significant dose variation was obtained for the Contura, Savi, MLM and Prostate applicators. Conclusion: This study data indicates that an improvement of the immobilization devices for HDR is absolutely necessary. Better applicator fixation devices are required too. Developing new immobilization devices for all the applicators is recommended. Florida Atlantic University may provide Travel reimbursements.

  6. Indoor air radon dose assessment for elementary, middle and high schools at Ulju county in Korea

    International Nuclear Information System (INIS)

    Lee, Choong Wie; Kim, Hee Reyoung

    2016-01-01

    Ulsan is the largest industrial city and possesses the largest area among 7 metropolitan cities in Korea. Ulju county is one of the administrative districts of Ulsan, and covers over 70 % of Ulsan and is surrounded by mountain to the east and sea to the west, which has urban and rural area. Thus, there are many geological and industrial condition in its environment. Ministry of Environment (ME) of Korea is carrying out radon survey every 2 years, but this survey focuses on radon radioactivity of the houses and radon survey for schools isn't detailed. At schools, people with various age work and are educated for a specific time, therefore, it is needed to analyze the radon radioactivity concentration of indoor air to estimate the effect by the radon exposure. Indoor air radon radioactivity concentration and dose of 57 schools including elementary, middle and high schools in Ulju county were analyzed by using alpha track. It was understood that average radon concentrations of schools in Ulju county were being maintained below recommendation level although survey results of some schools showed 295 Bq/m 3 higher than regulation of Ministry of Environment for radon concentration, 148 Bq/m 3 . Indoor annual effective dose of 0.157 mSv by radon was found to be less than 7 % of the natural radiation exposure of 2.4 mSv when ICRP dose coefficient for adult male was applied. It was thought that further radon effect analysis for various ages including children was needed for more accurate dose assessment

  7. Indoor air radon dose assessment for elementary, middle and high schools at Ulju county in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Choong Wie; Kim, Hee Reyoung [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Ulsan is the largest industrial city and possesses the largest area among 7 metropolitan cities in Korea. Ulju county is one of the administrative districts of Ulsan, and covers over 70 % of Ulsan and is surrounded by mountain to the east and sea to the west, which has urban and rural area. Thus, there are many geological and industrial condition in its environment. Ministry of Environment (ME) of Korea is carrying out radon survey every 2 years, but this survey focuses on radon radioactivity of the houses and radon survey for schools isn't detailed. At schools, people with various age work and are educated for a specific time, therefore, it is needed to analyze the radon radioactivity concentration of indoor air to estimate the effect by the radon exposure. Indoor air radon radioactivity concentration and dose of 57 schools including elementary, middle and high schools in Ulju county were analyzed by using alpha track. It was understood that average radon concentrations of schools in Ulju county were being maintained below recommendation level although survey results of some schools showed 295 Bq/m{sup 3} higher than regulation of Ministry of Environment for radon concentration, 148 Bq/m{sup 3}. Indoor annual effective dose of 0.157 mSv by radon was found to be less than 7 % of the natural radiation exposure of 2.4 mSv when ICRP dose coefficient for adult male was applied. It was thought that further radon effect analysis for various ages including children was needed for more accurate dose assessment.

  8. High dose per fraction dosimetry of small fields with Gafchromic EBT2 film

    International Nuclear Information System (INIS)

    Hardcastle, Nicholas; Basavatia, Amar; Bayliss, Adam; Tome, Wolfgang A.

    2011-01-01

    Purpose: Small field dosimetry is prone to uncertainties due to the lack of electronic equilibrium and the use of the correct detector size relative to the field size measured. It also exhibits higher sensitivity to setup errors as well as large variation in output with field size and shape. Radiochromic film is an attractive method for reference dosimetry in small fields due to its ability to provide 2D dose measurements while having minimal impact on the dose distribution. Gafchromic EBT2 has a dose range of up to 40 Gy; therefore, it could potentially be useful for high dose reference dosimetry with high spatial resolution. This is a requirement in stereotactic radiosurgery deliveries, which deliver high doses per fraction to small targets. Methods: Targets of 4 mm and 12 mm diameters were treated to a minimum peripheral dose of 21 Gy prescribed to 80% of the maximum dose in one fraction. Target doses were measured with EBT2 film (both targets) and an ion chamber (12 mm target only). Measured doses were compared with planned dose distributions using profiles through the target and minimum peripheral dose coverage. Results: The measured target doses and isodose coverage agreed with the planned dose within ±1 standard deviation of three measurements, which were 2.13% and 2.5% for the 4 mm and 12 mm targets, respectively. Conclusions: EBT2 film is a feasible dosimeter for high dose per fraction reference 2D dosimetry.

  9. The application of high dose food irradiation in South Africa

    Science.gov (United States)

    de Bruyn, Ingrid Nine

    2000-03-01

    During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive "dried cooked" taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between -20 and -40°C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa.

  10. The application of high dose food irradiation in South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Bruyn, Ingrid Nine de E-mail: debruyni@mweb.co.za

    2000-03-01

    During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive 'dried cooked' taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between -20 and -40 deg. C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa. (author)

  11. High dose implantations of antimony for buried layer applications

    International Nuclear Information System (INIS)

    Gailliard, J.P.; Dupuy, M.; Garcia, M.; Roussin, J.C.

    1978-01-01

    Electrical and physical properties of high dose implantations of antimony in silicon have been studied for use in buried layer applications. The results have been obtained both on and oriented silicon wafers. Following implantations which lead to amorphization we perform an annealing at 600 0 C for 10 mn in order to recrystallize the layer. The observed electrical properties (μ, R) show that the concentration of electrically active antimony ions is greater than that predicted from the solubility of antimony in silicon. Further annealing (in the range 1050 0 - 1200 0 ) induces: firstly a precipitation of the Sb and secondly a diffusion and dissolution of the precipitates. There is a different evolution of the defects in the and silicon slices. T.E.M. reveals no defects in the wafers after one hour annealing at 1200 0 C, whereas defects and twins remain in wafers. Having obtained the evolution of R with time and temperature it is then determined the implantation and annealing conditions which lead to the low resistivity (R = 10) needed for buried layer applications. Results with very many industrially made devices are discussed

  12. Cation disorder in high-dose, neutron-irradiated spinel

    International Nuclear Information System (INIS)

    Sickafus, K.E.; Larson, A.C.; Yu, N.; Nastasi, M.; Hollenberg, G.W.; Garner, F.A.; Bradt, R.C.

    1994-08-01

    The objective of this effort is to determine whether MgAl 2 O 4 spinel is a suitable ceramic for fusion applications. Here, the crystal structures of MgAl 2 O 4 spinel single crystals irradiated to high neutron fluences [>5·10 26 n/m 2 (E n > 0.1 MeV)] were examined by neutron diffraction. Crystal structure refinement of the highest dose sample indicated that the average scattering strength of the tetrahedral crystal sites decreased by ∼ 20% while increasing by ∼ 8% on octahedral sites. Since the neutron scattering length for Mg is considerably larger than for Al, this results is consistent with site exchange between Mg 2+ ions on tetrahedral sites and Al 3+ ions on octahedral sites. Least-squares refinements also indicated that, in all irradiated samples, at least 35% of Mg 2+ and Al 3+ ions in the crystal experienced disordering replacements. This retained dpa on the cation sublattices is the largest retained damage ever measured in an irradiated spinel material

  13. The application of high dose food irradiation in South Africa

    International Nuclear Information System (INIS)

    Bruyn, Ingrid Nine de

    2000-01-01

    During the 1950s to the end of the 1970s the United States Army developed the basic methodology to produce shelf-stable irradiated meat, seafood and poultry products. These products are normally packed without gravy, sauce or brine, as liquid is not required to sterilize the product as in the canning process. This leads to the distinctive 'dried cooked' taste normally associated with roasts opposed to the casserole taste usually associated with tinned meats. The Biogam group at the Atomic Energy Corporation of South Africa is currently producing shelf-stable irradiated meats on a commercial basis. The meats are cooked, chilled, portioned, vacuum packed and irradiated to the required minimum dose of 45 kGy at a temperature of between -20 and -40 deg. C to ensure absolute sterility even under tropical conditions. The product is packaged in a high quality four layer laminate pouch and will therefore not rust or burst even under adverse weather conditions and can be guaranteed for more than two years as long as the integrity of the packaging is maintained. Safari operators in remote parts of Africa, mountaineers, yachtsmen, canoeists and geological survey teams currently use shelf-stable irradiated meat products produced in South Africa. (author)

  14. Colon mucosal cells after high-dose fractional irradiation

    International Nuclear Information System (INIS)

    Zorc-Pleskovic, R.; Vraspir-Porenta, O.; Petrovic, D.; Zorc, M.; Pleskovic, L.

    2000-01-01

    The aim of this study was to investigate histological and stereological changes in cryptal enterocytes, mucosal lymphocytes and mast cells 10 days after irradiation. For experimental model, 24 Beagle dogs 1-2 years old were used. Twelve dogs were irradiated 20 days with 32 Gy over the whole pelvis and tail. Another 12 dogs represented a control group. For the detection of apoptosis, the TUNEL technique was used. Histological and stereological analyses were performed using a Wild sampling microscope M 1000. In the irradiated group, volume density (P < 0.01), numerical density (P < 0.05) and average volume of lymphocytes (P < 0.001) were significantly lower than in the nonirradiated group. Numerical areal density of mast cells in the irradiated group was also significantly lower (P < 0.05). Volume density (P < 0.001) and average volume of mast cells (P < 0.001) were significantly higher in the irradiated group. The results of our experiments show that irradiation causes injury and loss of lymphocytes and mast cells in the colon mucosa. Apoptosis was detected in enterocytes and lymphocytes in the irradiated group and in nonirradiated group in equal numbers (2.5 ± 0.3 vs. 2.3 ± 0.3; ns.), suggesting that 10 days after high-dose irradiation, the cell loss is not due to apoptosis. (author)

  15. High dose neutron irradiation damage in beryllium as blanket material

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V.P. E-mail: fae@niiar.ru; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B. E-mail: vniinm.400@g23.relkom.ru

    2001-11-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10{sup 22} and 8.0x10{sup 22} cm{sup -2} (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10{sup 22} cm{sup -2} (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10{sup 22} cm{sup -2} (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket.

  16. High dose neutron irradiation damage in beryllium as blanket material

    International Nuclear Information System (INIS)

    Chakin, V.P.; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B.

    2001-01-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10 22 and 8.0x10 22 cm -2 (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10 22 cm -2 (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10 22 cm -2 (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket

  17. High dose progesterone effects the growth of early chick embryo

    International Nuclear Information System (INIS)

    Iqbal, I.; Qamar, K.

    2014-01-01

    Objective: To find out the effect of high dose progesterone on the development of early chick embryo. Study Design: Lab based randomized controlled trial. Place and Duration of study: This study was carried out in Army Medical College and Post Graduate Institute of Poultry Sciences, Rawalpindi from June 2010 - December 2010. Material and Methods: Forty five specific pathogen free, fertile, eggs of Fyoumi species of chick were selected at zero hour of incubation. They were incubated at 37.5oC and 75% relative humidity for 26 hrs until the embryos reached stage 8 of the development. Then on stage 8 the eggs were divided into three groups consisting of 15 eggs per group. The first group (GI) was incubated without any operation. The second (G2) and third groups (G3) were injected with two and twenty times more than physiologic does of progesterone respectively. After 48 hours of incvbation, all embryos were examined for their development under light microscopy. Results: All the embryos of G1 and G2 showed normal development according to their stage of development, while 4 out of 11 embryos of G3 were under developed and their survival rate was also less. Conclusion: Exogenous progesterone at levels twenty times above its physiologic range effects the development of chick embryos. Further studies are needed to explain the mechanisms of this effect. (author)

  18. Bioequivalence of generic lamotrigine 100-mg tablets in healthy Thai male volunteers: a randomized, single-dose, two-period, two-sequence crossover study.

    Science.gov (United States)

    Srichaiya, Arunee; Longchoopol, Chaowanee; Oo-Puthinan, Sarawut; Sayasathid, Jarun; Sripalakit, Pattana; Viyoch, Jarupa

    2008-10-01

    Lamotrigine is an antiepileptic drug which has been used in the treatment of epilepsy and bipolar disorder. A search of the literature did not find previously published bioequivalence and pharmacokinetic evaluations of lamotrigine in healthy Thai male volunteers. The aim of this study was to compare the pharmacokinetic parameters between 2 brands of lamotrigine in healthy Thai male volunteers. A randomized, single-dose, 2-period, 2-sequence, crossover study design with a 2-week washout period was conducted in healthy Thai males. Subjects were randomized to receive either the test or reference formulation in the first period. All subjects were required to be nonsmokers and without a history of alcohol or drug abuse. Plasma samples were collected over a 120-hour period after 100-mg lamotrigine administration in each period. A validated high-performance liquid chromatography ultraviolet method was used to analyze lamotrigine concentration in plasma. Pharmacokinetic parameters were determined using a noncompartmental method. Bioequivalence between the test and reference products, as defined by the US Food and Drug Administration (FDA), is determined when the ratio for the 90% CIs of the difference in the means of the log-transformed AUC(0-t), AUC(0-infinity), and C(max) of the 2 products are within 0.80 and 1.25. Adverse events were determined by measuring vital signs after dosing. Subjects were also asked if they suffered from undesirable effects such as nausea, vomiting, dizziness, and headache. This bioequivalence study was performed in 24 healthy Thai males (mean [SD] age, 20.5 [1.3] years; range, 19-24 years; weight, 62.5 [7.4] kg; height, 172.8 [6.9] cm; body mass index, 20.9 [2.0] kg/m(2)). The mean (SD) C(max) and T(max) of the test formulation of lamotrigine were 1.7 (0.3) microg/mL and 1.2 (0.9) hours, respectively. The mean (SD) C(max) and T(max) of the reference formulation of lamotrigine were 1.7 (0.3) microg/mL and 1.4 (1.0) hours, respectively. The mean

  19. A comparison of high dose Ga-67 SPECT and FDG PET imaging in malignant melanoma

    International Nuclear Information System (INIS)

    Kaliff, V.; Hicks, R.J.; Binns, D.S.; Henderson, M.A.; Ainslie, J.; Jenner, D.A.

    1998-01-01

    Full text: Ga-67 imaging for tumour localisation lost favour in the 1970's. With improvement in technology and use of higher doses, it has now found an important role in lymphoma. A similar phenomenon may be possible in the staging of melanoma. This study therefore compares high dose (370 MBq) Ga-67 imaging using a day 5 and 7 whole-body and comprehensive SPECT protocol, with (100 MBq) F-18 fluorodeoxyglucose (FDG) imaging using positron emission tomography (PET): a technique recently shown to be highly accurate in this condition. 85 patients; 46 males, mean age 52+17 yrs: range 22-83 yrs, underwent both studies within 9±16 days (max-91 days). Scans were judged as positive (+ve), negative (-ve) or equivocal (EQ) for local, regional and distant disease. Clinical follow-up resolved discordant scan findings. PET and Ga-67 results were concordant in 61 (70%) patients (19 with +ve, 37 -ve and 5 EQ scans). None of the 9 ps with one EQ and one eye scan had disease on follow-up. Follow-up was available in 4/5 patients with discordantly +ve (3 patients) or more extensive Ga-67 abnormality: 3 patients had disease confirmed, 1 patient false +ve (asymmetric lung hilum). Follow-up was available in 9/10 patients with discordantly +ve (3 patients) or more extensive PET abnormality: 4 patients had confirmed disease, l pt false +ve (bladder diverticulum). A further 4 patients had second primaries (2 rectal carcinomas, 1 plasmacytoma, 1 basal cell carcinoma). High dose Ga-67 scanning incorporating SPECT appears to be a reasonable alternative to FDG PET for screening patients with melanoma. In this series PET's main advantages were in the detection of other occult tumours, greater patient convenience and lower radiation dosimetry

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

    Directory of Open Access Journals (Sweden)

    Li-Min Liou

    2006-03-01

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

  1. The use of the mouse chimera assay to detect early embryonic damage from male mice exposed to low-dose radiation

    International Nuclear Information System (INIS)

    Oudiz, D.; Warner, P.; Walsh, K.J.; Wiley, L.

    1990-01-01

    Mouse chimeras are in vitro aggregations of two 4-cell embryos and are used to detect subtle, nonlethal changes, which are expressed as a proliferative disadvantage in exposed embryos. One of the embryos is labeled with a viable dye (FITC) in order to determine the relative cellular contribution of each embryo when the chimera is dissociated 40 hours later. This proliferative disadvantage has been seen at doses which do not produce an effect on cell number when the embryos are cultured singly. Previously, the assay has detected a decrease in cellular proliferation in embryos from male mice exposed to a single dose of x-radiation as low as 0.05 Gy. In the current study, male mice were irradiated with a single dose of 0, 0.001, 0.01, or 0.05 Gy, and then serially mated for the next 8 weeks to unexposed females. Chimeras were constructed from control and treated embryos. Embryos from males treated with 0.05 Gy exhibited a significant decrease in cellular proliferation during weeks 6 and 7 post-irradiation. A similar decrease was seen in the males treated with 0.01 Gy. No reductions were observed from embryos cultured singly in any of the treatment groups

  2. Identifying high dose activities in industrial site radiography

    International Nuclear Information System (INIS)

    Heaton, B.

    2000-01-01

    Although the radiation doses received by industrial radiographers in the UK have progressively fallen over the last few years, with most now receiving less than 1 mSv/y, a few still receive, relative to the rest, much higher doses. As a percentage of all radiographers the number stays surprisingly constant from year to year. This paper describes a survey to identify the work causing these doses and suggest possible solutions. The UK Central Index of Dose Information was interrogated to identify the industrial radiography companies having staff (not necessarily the same person) with doses of greater than 5mSv/y in the last three years for which information was available. This was 15 in total. The people on the staff receiving these doses were identified and a questionnaire sent to the companies concerned requesting information about their work. A general questionnaire about the operation of the company was also included. With the agreement of the company these questionnaires were followed up by a visit to the company to interviews a number of the management and the radiographers if available. Both groups were generally very open about their problems and every discussion had a positive outcome. Several areas of work/reasons for the doses have been identified. These are: pipeline radiography, ultra sound radiographers working on nuclear reactors, complex plant work often with several teams in the area, inability to retreat from the wind out equipment due to height or access problems, site pressure to not follow the best practices and a lack of appreciation when a dose was being received or, alternatively, carelessness. Some o these problem areas are very difficult to resolve. However ways in which the Health and Safety can help influence the doses have been identified together with practical suggestions radiographers could adopt. These will be reported. (author)

  3. Serum total homocystein, folate and vitamin B12 levels and their correlation with antipsychotic drug doses in adult male patients with chronic schizophrenia.

    Science.gov (United States)

    Eren, Esin; Yeğin, Ayşenur; Yilmaz, Necat; Herken, Hasan

    2010-01-01

    Elevated blood levels of homocysteine (hCY) have been associated with schizophrenic male patients. However, controversy remains regarding the association between lowered plasma folate and vitamin B12, hyperhomocysteinemia, and schizophrenia. Sixty-six (66) male patients with chronic schizophrenia were investigated to test the hypotheses that alterations in Hcy, folate, and vitamin B12 levels might be related to the antipsychotic drug doses used in treatment. Serum total homocysteine, folic acid, and vitamin B12 levels were determined by chemiluminescence methods in both patients and control subjects. The patients were grouped according to the antipsychotic drug doses used in their treatment. Patients had higher homocysteine levels but they did not differ from controls in terms of folate and vitamin B12 levels. On the other hand, only folate levels were negatively correlated in the patient group treated with higher therapeutic doses of chlorpromazine equivalents (> 400 mg/day) compared to the patient group with lower doses (< 400 mg/day). Our findings show that higher typical antipsychotic drugs may play a role as modifiying factor for folate metabolism in chronic schizoprenic male patients.

  4. 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

  5. High-dose-rate brachytherapy in uterine cervical carcinoma

    International Nuclear Information System (INIS)

    Patel, Firuza D.; Rai, Bhavana; Mallick, Indranil; Sharma, Suresh C.

    2005-01-01

    Purpose: High-dose-rate (HDR) brachytherapy is in wide use for curative treatment of cervical cancer. The American Brachytherapy Society has recommended that the individual fraction size be <7.5 Gy and the range of fractions should be four to eight; however, many fractionation schedules, varying from institution to institution, are in use. We use 9 Gy/fraction of HDR in two to five fractions in patients with carcinoma of the uterine cervix. We found that our results and toxicity were comparable to those reported in the literature and hereby present our experience with this fractionation schedule. Methods and Materials: A total of 121 patients with Stage I-III carcinoma of the uterine cervix were treated with HDR brachytherapy between 1996 and 2000. The total number of patients analyzed was 113. The median patient age was 53 years, and the histopathologic type was squamous cell carcinoma in 93% of patients. The patients were subdivided into Groups 1 and 2. In Group 1, 18 patients with Stage Ib-IIb disease, tumor size <4 cm, and preserved cervical anatomy underwent simultaneous external beam radiotherapy to the pelvis to a dose of 40 Gy in 20 fractions within 4 weeks with central shielding and HDR brachytherapy of 9 Gy/fraction, given weekly, and interdigitated with external beam radiotherapy. The 95 patients in Group 2, who had Stage IIb-IIIb disease underwent external beam radiotherapy to the pelvis to a dose of 46 Gy in 23 fractions within 4.5 weeks followed by two sessions of HDR intracavitary brachytherapy of 9 Gy each given 1 week apart. The follow-up range was 3-7 years (median, 36.4 months). Late toxicity was graded according to the Radiation Therapy Oncology Group criteria. Results: The 5-year actuarial local control and disease-free survival rate was 74.5% and 62.0%, respectively. The actuarial local control rate at 5 years was 100% for Stage I, 80% for Stage II, and 67.2% for Stage III patients. The 5-year actuarial disease-free survival rate was 88.8% for

  6. Blood responses under chronic low daily dose gamma irradiation: Pt. 1; Differential preclinical responses of irradiated male dogs in progression to either aplastic anemia or myeloproliferative disease

    Energy Technology Data Exchange (ETDEWEB)

    Seed, T.M.; Carnes, B.A.; Tolle, D.V.; Fritz, T.E. (Argonne National Lab., IL (USA))

    1989-01-01

    Male beagles chronically exposed to low daily doses of {sup 60}Co {gamma} rays show one of three hematopoietic patterns, which reflect three different distinctly responding subgroups: (1) low radioresistance with progressing aplastic anemia and shortened survival ({sup -S}-AA subgroup); (2) high radioresistance with a complex of progressing myeloproliferative disorders ({sup +}R-MPD group); or (3) high radioresistance with other nonMPD syndromes ({sup +}R-nonMPD group). Blood cell levels (granulocytes, monocytes, erythrocytes, lymphocytes, and platelets) were assessed and fitted to a flexible polynomial spline model. Results showed that relative to the overall magnitude of blood cell loss as well as to the maximum rate of suppression during the initial phase, the subgroups were generally ranked {sup -}S-AA >> {sup +}R-MPD > {sup +}R-nonMPD. Relative to the overall strength of the recovery response, the subgroups were generally ranked {sup +}R-MPD > {sup +}R-nonMPD >>> {sup -}S-AA. In terms of overall maintenance levels of circulating blood cells during the recovery phase, however, the {sup +}R-nonMPD subgroup consistently exhibited stronger responses than the {sup +}R-MPD subgroup. These results support our contention that selected subgroups of dogs have strong propensities to specific hematopathologies (i.e. aplastic anemia and myeloid leukemia) under chronic irradiation and that these pathology-prone animals exhibit a series of marked differential hematopoietic responses during early preclinical phases, which serve effectively to prognosticate subsequent pathological progression. (author).

  7. Efficacy and Safety of Single and Double Doses of Ivermectin versus 7-Day High Dose Albendazole for Chronic Strongyloidiasis

    Science.gov (United States)

    Suputtamongkol, Yupin; Premasathian, Nalinee; Bhumimuang, Kid; Waywa, Duangdao; Nilganuwong, Surasak; Karuphong, Ekkapun; Anekthananon, Thanomsak; Wanachiwanawin, Darawan; Silpasakorn, Saowaluk

    2011-01-01

    , and double doses of oral ivermectin respectively (P = 0.006) in modified intention to treat analysis. No serious adverse event associated with treatment was found in any of the groups. Conclusion/Significance This study confirms that both a single, and a double dose of oral ivermectin taken two weeks apart, is more effective than a 7-day course of high dose albendazole for patients with chronic infection due to S. stercoralis. Double dose of ivermectin, taken two weeks apart, might be more effective than a single dose in patients with concomitant illness. Trial Registration ClinicalTrials.gov NCT00765024 PMID:21572981

  8. Independent verification of the delivered dose in High-Dose Rate (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Portillo, P.; Feld, D.; Kessler, J.

    2009-01-01

    An important aspect of a Quality Assurance program in Clinical Dosimetry is an independent verification of the dosimetric calculation done by the Treatment Planning System for each radiation treatment. The present paper is aimed at creating a spreadsheet for the verification of the dose recorded at a point of an implant with radioactive sources and HDR in gynecological injuries. An 192 Ir source automatic differed loading equipment, GammaMedplus model, Varian Medical System with HDR installed at the Angel H. Roffo Oncology Institute has been used. The planning system implemented for getting the dose distribution is the BraquiVision. The sources coordinates as well as those of the calculation point (Rectum) are entered into the Excel-devised verification program by assuming the existence of a point source in each one of the applicators' positions. Such calculation point has been selected as the rectum is an organ at risk, therefore determining the treatment planning. The dose verification is performed at points standing at a sources distance having at least twice the active length of such sources, so they may be regarded as point sources. Most of the sources used in HDR brachytherapy with 192 Ir have a 5 mm active length for all equipment brands. Consequently, the dose verification distance must be at least of 10 mm. (author)

  9. High doses dosimetry in irradiation process in Argentine

    International Nuclear Information System (INIS)

    Dorda de Cancio, E.M.

    1997-01-01

    These report describes the lung dose dosimetry procedures of the Semi-Industrial Irradiation Plant in Ezeisa Atomic (500,00 Ci of Co 60) and Industrial Picorrad Plant (400,00 Ci of Co 60) using the nitrate dosimeter

  10. High dose rate (HDR) and low dose rate (LDR) interstitial irradiation (IRT) of the rat spinal cord

    International Nuclear Information System (INIS)

    Pop, Lucas A.M.; Plas, Mirjam van der; Skwarchuk, Mark W.; Hanssen, Alex E.J.; Kogel, Albert J. van der

    1997-01-01

    Purpose: To describe a newly developed technique to study radiation tolerance of rat spinal cord to continuous interstitial irradiation (IRT) at different dose rates. Material and methods: Two parallel catheters are inserted just laterally on each side of the vertebral bodies from the level of Th 10 to L 4 . These catheters are afterloaded with two 192 Ir wires of 4 cm length each (activity 1-2.3 mCi/cm) for the low dose rate (LDR) IRT or connected to the HDR micro-Selectron for the high dose rate (HDR) IRT. Spinal cord target volume is located at the level of Th 12 -L 2 . Due to the rapid dose fall-off around the implanted sources, a dose inhomogeneity across the spinal cord thickness is obtained in the dorso-ventral direction. Using the 100% reference dose (rate) at the ventral side of the spinal cord to prescribe the dose, experiments have been carried out to obtain complete dose response curves at average dose rates of 0.49, 0.96 and 120 Gy/h. Paralysis of the hind-legs after 5-6 months and histopathological examination of the spinal cord of each irradiated rat are used as experimental endpoints. Results: The histopathological damage seen after irradiation is clearly reflected the inhomogeneous dose distribution around the implanted catheters, with the damage predominantly located in the dorsal tract of the cord or dorsal roots. With each reduction in average dose rate, spinal cord radiation tolerance is significantly increased. When the dose is prescribed at the 100% reference dose rate, the ED 50 (induction of paresis in 50% of the animals) for the HDR-IRT is 17.3 Gy. If the average dose rate is reduced from 120 Gy/h to 0.96 or 0.49 Gy/h, a 2.9- or 4.7-fold increase in the ED 50 values to 50.3 Gy and 80.9 Gy is observed; for the dose prescribed at the 150% reference dose rate (dorsal side of cord) ED 50 values are 26.0, 75.5 and 121.4 Gy, respectively. Using different types of analysis and in dependence of the dose prescription and reference dose rate, the

  11. Prenatal and early postnatal NOAEL-dose clothianidin exposure leads to a reduction of germ cells in juvenile male mice.

    Science.gov (United States)

    Yanai, Shogo; Hirano, Tetsushi; Omotehara, Takuya; Takada, Tadashi; Yoneda, Naoki; Kubota, Naoto; Yamamoto, Anzu; Mantani, Youhei; Yokoyama, Toshifumi; Kitagawa, Hiroshi; Hoshi, Nobuhiko

    2017-07-07

    Neonicotinoids are pesticides used worldwide. They bind to insect nicotinic acetylcholine receptors (nAChRs) with high affinity. We previously reported that clothianidin (CTD), one of the latest neonicotinoids, reduced antioxidant expression and induced germ cell death in the adult testis of vertebrates. Here, we investigated the male reproductive toxicity of prenatal and early postnatal exposure to CTD, because it is likely that developmental exposure more severely affects the testis compared to adults due to the absence of the blood-testis barrier. Pregnant C57BL/6 mice were given water gel blended with CTD (0, 10 or 50 mg/kg/day; no-observed-adverse-effect-level [NOAEL for mice]: 47.2 mg/kg/day) between gestational day 1 and 14 days post-partum. We then examined the testes of male offspring at postnatal day 14. The testis weights and the numbers of germ cells per seminiferous tubule were decreased in the CTD-50 group, and abnormal tubules containing no germ cells appeared. Nevertheless, the apoptotic cell number and proliferative activity were not significantly different between the control and CTD-exposed groups. There were no significant differences in the androgen-related parameters, such as the Leydig cell volume per testis, the Sertoli cell number and the tubule diameter. The present study is the first demonstration that in utero and lactational exposures to CTD at around the NOAEL for mice reduce the germ cell number, but our findings suggest that these exposures do not affect steroidogenesis in Leydig cells during prenatal or early postnatal life.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  13. Dose conversion coefficients for high-energy photons, electrons, neutrons and protons

    CERN Document Server

    Sakamoto, Y; Sato, O; Tanaka, S I; Tsuda, S; Yamaguchi, Y; Yoshizawa, N

    2003-01-01

    In the International Commission on Radiological Protection (ICRP) 1990 Recommendations, radiation weighting factors were introduced in the place of quality factors, the tissue weighting factors were revised, and effective doses and equivalent doses of each tissues and organs were defined as the protection quantities. Dose conversion coefficients for photons, electrons and neutrons based on new ICRP recommendations were cited in the ICRP Publication 74, but the energy ranges of theses data were limited and there are no data for high energy radiations produced in accelerator facilities. For the purpose of designing the high intensity proton accelerator facilities at JAERI, the dose evaluation code system of high energy radiations based on the HERMES code was developed and the dose conversion coefficients of effective dose were evaluated for photons, neutrons and protons up to 10 GeV, and electrons up to 100 GeV. The dose conversion coefficients of effective dose equivalent were also evaluated using quality fact...

  14. High versus low-dose rate brachytherapy for cervical cancer.

    Science.gov (United States)

    Patankar, Sonali S; Tergas, Ana I; Deutsch, Israel; Burke, William M; Hou, June Y; Ananth, Cande V; Huang, Yongmei; Neugut, Alfred I; Hershman, Dawn L; Wright, Jason D

    2015-03-01

    Brachytherapy plays an important role in the treatment of cervical cancer. While small trials have shown comparable survival outcomes between high (HDR) and low-dose rate (LDR) brachytherapy, little data is available in the US. We examined the utilization of HDR brachytherapy and analyzed the impact of type of brachytherapy on survival for cervical cancer. Women with stages IB2-IVA cervical cancer treated with primary (external beam and brachytherapy) radiotherapy between 2003-2011 and recorded in the National Cancer Database (NCDB) were analyzed. Generalized linear mixed models and Cox proportional hazards regression were used to examine predictors of HDR brachytherapy use and the association between HDR use and survival. A total of 10,564 women including 2681 (25.4%) who received LDR and 7883 (74.6%) that received HDR were identified. Use of HDR increased from 50.2% in 2003 to 83.9% in 2011 (Puse of HDR. While patients in the Northeast were more likely to receive HDR therapy, there were no other clinical or socioeconomic characteristics associated with receipt of HDR. In a multivariable Cox model, survival was similar between the HDR and LDR groups (HR=0.93; 95% CI 0.83-1.03). Similar findings were noted in analyses stratified by stage and histology. Kaplan-Meier analyses demonstrated no difference in survival based on type of brachytherapy for stage IIB (P=0.68), IIIB (P=0.17), or IVA (P=0.16) tumors. The use of HDR therapy has increased rapidly. Overall survival is similar for LDR and HDR brachytherapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Escalation to High Dose Defibrotide in Patients with Hepatic Veno-Occlusive Disease

    Science.gov (United States)

    Triplett, Brandon M.; Kuttab, Hani I.; Kang, Guolian; Leung, Wing

    2015-01-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of high-dose chemotherapy regimens, such as those utilized in hematopoietic cell transplantation recipients. Defibrotide is considered a safe and effective treatment when dosed at 25 mg/kg/day. However, patients who develop VOD still have increased mortality despite the use of defibrotide. Data are limited on the use of doses above 60 mg/kg/day for persistent VOD. In this prospective clinical trial, 34 patients received escalating doses of defibrotide. For patients with persistent VOD despite doses of 60 mg/kg/day, doses were increased to a maximum of 110 mg/kg/day. There was no observed increase in toxicity until doses rose beyond 100 mg/kg/day. Patients receiving doses between 10–100 mg/kg/day experienced an average of 3 bleeding episodes per 100 days of treatment, while those receiving doses >100 mg/kg/day experienced 13.2 bleeding episodes per 100 days (p=0.008). Moreover, dose reductions due to toxicity were needed at doses of 110 mg/kg/day more often than at lower doses. Defibrotide may be safely escalated to doses well above the current standard without an increase in bleeding risk. However, the efficacy of this dose escalation strategy remains unclear, as outcomes were similar to published cohorts of patients receiving standard doses of defibrotide for VOD. PMID:26278046

  16. Escalation to High-Dose Defibrotide in Patients with Hepatic Veno-Occlusive Disease.

    Science.gov (United States)

    Triplett, Brandon M; Kuttab, Hani I; Kang, Guolian; Leung, Wing

    2015-12-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of high-dose chemotherapy regimens, such as those used in hematopoietic cell transplantation recipients. Defibrotide is considered a safe and effective treatment when dosed at 25 mg/kg/day. However, patients who develop VOD still have increased mortality despite the use of defibrotide. Data are limited on the use of doses above 60 mg/kg/day for persistent VOD. In this prospective clinical trial 34 patients received escalating doses of defibrotide. For patients with persistent VOD despite doses of 60 mg/kg/day, doses were increased to a maximum of 110 mg/kg/day. Increased toxicity was not observed until doses rose beyond 100 mg/kg/day. Patients receiving doses between 10 and 100 mg/kg/day experienced an average of 3 bleeding episodes per 100 days of treatment, whereas those receiving doses >100 mg/kg/day experienced 13.2 bleeding episodes per 100 days (P = .008). Moreover, dose reductions due to toxicity were needed at doses of 110 mg/kg/day more often than at lower doses. Defibrotide may be safely escalated to doses well above the current standard without an increase in bleeding risk. However, the efficacy of this dose-escalation strategy remains unclear, because outcomes were similar to published cohorts of patients receiving standard doses of defibrotide for VOD. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  17. Mutation frequencies in male mice and the estimation of genetic hazards of radiation in men: (specific-locus mutations/dose-rate effect/doubling dose/risk estimation)

    International Nuclear Information System (INIS)

    Russell, W.L.; Kelly, E.M.

    1982-01-01

    Estimation of the genetic hazards of ionizing radiation in men is based largely on the frequency of transmitted specific-locus mutations induced in mouse spermatogonial stem cells at low radiation dose rates. The publication of new data on this subject has permitted a fresh review of all the information available. The data continue to show no discrepancy from the interpretation that, although mutation frequency decreases markedly as dose rate is decreased from 90 to 0.8 R/min (1 R = 2.6 X 10 -4 coulombs/kg) there seems to be no further change below 0.8 R/min over the range from that dose rate to 0.0007 R/min. Simple mathematical models are used to compute: (a) a maximum likelihood estimate of the induced mutation frequency at the low dose rates, and (b) a maximum likelihood estimate of the ratio of this to the mutation frequency at high dose rates in the range of 72 to 90 R/min. In the application of these results to the estimation of genetic hazards of radiation in man, the former value can be used to calculate a doubling dose - i.e., the dose of radiation that induces a mutation frequency equal to the spontaneous frequency. The doubling dose based on the low-dose-rate data compiled here is 110 R. The ratio of the mutation frequency at low dose rate to that at high dose rate is useful when it becomes necessary to extrapolate from experimental determinations, or from human data, at high dose rates to the expected risk at low dose rates. The ratio derived from the present analysis is 0.33

  18. Skeletal muscle and performance adaptations to high-intensity training in elite male soccer players

    DEFF Research Database (Denmark)

    Fransson, Dan; Nielsen, Tobias Schmidt; Olsson, Karl

    2018-01-01

    PURPOSE: To examine the skeletal muscle and performance responses across two different exercise training modalities which are highly applied in soccer training. METHODS: Using an RCT design, 39 well-trained male soccer players were randomized into either a speed endurance training (SET; n = 21...... pronouncedly than small-sided game training, but comparable responses were in muscle ion transporters and antioxidative capacity in well-trained male soccer players....

  19. High dose-per-pulse electron beam dosimetry: Usability and dose-rate independence of EBT3 Gafchromic films.

    Science.gov (United States)

    Jaccard, Maud; Petersson, Kristoffer; Buchillier, Thierry; Germond, Jean-François; Durán, Maria Teresa; Vozenin, Marie-Catherine; Bourhis, Jean; Bochud, François O; Bailat, Claude

    2017-02-01

    The aim of this study was to assess the suitability of Gafchromic EBT3 films for reference dose measurements in the beam of a prototype high dose-per-pulse linear accelerator (linac), capable of delivering electron beams with a mean dose-rate (Ḋ m ) ranging from 0.07 to 3000 Gy/s and a dose-rate in pulse (Ḋ p ) of up to 8 × 10 6 Gy/s. To do this, we evaluated the overall uncertainties in EBT3 film dosimetry as well as the energy and dose-rate dependence of their response. Our dosimetric system was composed of EBT3 Gafchromic films in combination with a flatbed scanner and was calibrated against an ionization chamber traceable to primary standard. All sources of uncertainties in EBT3 dosimetry were carefully analyzed using irradiations at a clinical radiotherapy linac. Energy dependence was investigated with the same machine by acquiring and comparing calibration curves for three different beam energies (4, 8 and 12 MeV), for doses between 0.25 and 30 Gy. Ḋ m dependence was studied at the clinical linac by changing the pulse repetition frequency (f) of the beam in order to vary Ḋ m between 0.55 and 4.40 Gy/min, while Ḋ p dependence was probed at the prototype machine for Ḋ p ranging from 7 × 10 3 to 8 × 10 6 Gy/s. Ḋ p dependence was first determined by studying the correlation between the dose measured by films and the charge of electrons measured at the exit of the machine by an induction torus. Furthermore, we compared doses from the films to independently calibrated thermo-luminescent dosimeters (TLD) that have been reported as being dose-rate independent up to such high dose-rates. We report that uncertainty below 4% (k = 2) can be achieved in the dose range between 3 and 17 Gy. Results also demonstrated that EBT3 films did not display any detectable energy dependence for electron beam energies between 4 and 12 MeV. No Ḋ m dependence was found either. In addition, we obtained excellent consistency between films and TLDs over the entire Ḋ p

  20. Biological impact of high-dose and dose-rate radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Maliev, V.; Popov, D. [Russian Academy of Science, Vladicaucas (Russian Federation); Jones, J.; Gonda, S. [NASA -Johnson Space Center, Houston (United States); Prasad, K.; Viliam, C.; Haase, G. [Antioxida nt Research Institute, Premier Micronutrient Corporation, Novato (United States); Kirchin, V. [Moscow State Veterinary and Biotechnology Acade my, Moscow (Russian Federation); Rachael, C. [University Space Research Association, Colorado (United States)

    2006-07-01

    Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

  1. Biological impact of high-dose and dose-rate radiation exposure

    International Nuclear Information System (INIS)

    Maliev, V.; Popov, D.; Jones, J.; Gonda, S.; Prasad, K.; Viliam, C.; Haase, G.; Kirchin, V.; Rachael, C.

    2006-01-01

    Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

  2. Cancer radiotherapy based on femtosecond IR laser-beam filamentation yielding ultra-high dose rates and zero entrance dose.

    Science.gov (United States)

    Meesat, Ridthee; Belmouaddine, Hakim; Allard, Jean-François; Tanguay-Renaud, Catherine; Lemay, Rosalie; Brastaviceanu, Tiberius; Tremblay, Luc; Paquette, Benoit; Wagner, J Richard; Jay-Gerin, Jean-Paul; Lepage, Martin; Huels, Michael A; Houde, Daniel

    2012-09-18

    Since the invention of cancer radiotherapy, its primary goal has been to maximize lethal radiation doses to the tumor volume while keeping the dose to surrounding healthy tissues at zero. Sadly, conventional radiation sources (γ or X rays, electrons) used for decades, including multiple or modulated beams, inevitably deposit the majority of their dose in front or behind the tumor, thus damaging healthy tissue and causing secondary cancers years after treatment. Even the most recent pioneering advances in costly proton or carbon ion therapies can not completely avoid dose buildup in front of the tumor volume. Here we show that this ultimate goal of radiotherapy is yet within our reach: Using intense ultra-short infrared laser pulses we can now deposit a very large energy dose at unprecedented microscopic dose rates (up to 10(11) Gy/s) deep inside an adjustable, well-controlled macroscopic volume, without any dose deposit in front or behind the target volume. Our infrared laser pulses produce high density avalanches of low energy electrons via laser filamentation, a phenomenon that results in a spatial energy density and temporal dose rate that both exceed by orders of magnitude any values previously reported even for the most intense clinical radiotherapy systems. Moreover, we show that (i) the type of final damage and its mechanisms in aqueous media, at the molecular and biomolecular level, is comparable to that of conventional ionizing radiation, and (ii) at the tumor tissue level in an animal cancer model, the laser irradiation method shows clear therapeutic benefits.

  3. Share of erythema dose of solar radiation in high mountains

    International Nuclear Information System (INIS)

    Blumthaler, M.; Ambach, W.

    1987-01-01

    The erythema dose was measured using a Robertson-Berger Sunburn Meter. The spectral sensitivity of the detector is adapted to an erythema action spectrum with the optical center at about 300 nm. The erythema dose is expressed in the biologically relevant Sunburn Units (SU). The Robertson-Berger Sunburn Meter has been recommended by the WMO for global monitoring of solar UV-B erythema dose. UV-A radiation was measured with a UV-radiometer. The spectral sensitivity of the detector has a flat maximum at 345 nm and a half band width of +- 25 nm. Global radiation was measured using a pyranometer. All detectors were placed horizontally and calibrated several times. Readings were taken in intervals of one minute

  4. Secondary intracranial meningiomas after high-dose cranial irradiation: report of five cases and review of the literature

    International Nuclear Information System (INIS)

    Strojan, Primoz; Popovic, Mara; Jereb, Berta

    2000-01-01

    Purpose: To review cases of secondary intracranial meningiomas following high-dose cranial irradiation (≥ 10 Gy) identified in Slovenia between 1968 and 1998, to determine their histological profile and to review the literature on this topic. Methods and Materials: Personal files of patients treated for secondary intracranial meningioma during a 31-year period were reviewed. In cases which met the criteria for radiation-induced tumors, steroid hormone receptor and Ki-67 status were analyzed. For the literature review, computerized database systems and reference lists from respective publications were used. Results: Five patients (2 females, 3 males), 3-11 years old at the time of cranial irradiation, developed secondary meningioma after a latency period of 9.5-31.5 years. Three patients had multiple tumors and 2 developed recurrent disease. Of 9 histologically examined tumors, 5 were graded as benign and 4 as atypical meningiomas, with Ki-67 proliferative index 3.2 ± 3.6 and 10 ± 6, respectively. The ratio between positive and negative meningiomas regarding immunostaining for progesterone and estrogen receptors was eight-to-one and six-to-three, respectively. Cumulative actuarial risk of secondary meningioma in a cohort of 445 children 16 years or younger treated with high-dose cranial irradiation between 1968 and 1990 in Slovenia at 10, 20, and 25 years was 0.53%, 1.2%, and 8.18%, respectively. Out of 126 cases of radiation-induced meningiomas reported, 57% were females and 43% were males, with mean age at presentation 33 ± 17.3 years. The majority (68%) of patients was irradiated during childhood. The latency period was significantly shorter in those who aged 5 years or less at the time of cranial irradiation (p = 0.04), and in those with atypical/anaplastic tumor (p = 0.01). Correlation between radiation dose and latency period could not be found. Conclusion: Secondary meningiomas following high-dose cranial irradiation are characterized by younger age at

  5. National Estimates of Male and Female Enrolment in American High School Choirs, Bands and Orchestras

    Science.gov (United States)

    Elpus, Kenneth

    2015-01-01

    The purpose of this study was to estimate, at a national level and over time, the participation rates of males and females among those students who formally enrol in American high school music ensembles. Ten cohorts of nationally representative samples of students from 1982 and 2009 were analysed using data from High School Transcript Studies…

  6. Dose conversion coefficients for high-energy photons, electrons, neutrons and protons

    International Nuclear Information System (INIS)

    Sakamoto, Yukio

    2005-01-01

    Dose conversion coefficients for photons, electrons and neutrons based on new ICRP recommendations were cited in the ICRP Publication 74, but the energy ranges of these data were limited and there are no data for high energy radiations produced in accelerator facilities. For the purpose of designing the high intensity proton accelerator facilities at JAERI, the dose evaluation code system of high energy radiations based on the HERMES code was developed and the dose conversion coefficients of effective dose were evaluated for photons, neutrons and protons up to 10 GeV, and electrons up to 100 GeV. The dose conversion coefficients of effective dose equivalent were also evaluated using quality factors to consider the consistency between radiation weighting factors and Q-L relationship. The effective dose conversion coefficients obtained in this work were in good agreement with those recently evaluated by using FLUKA code for photons and electrons with all energies, and neutrons and protons below 500 MeV. There were some discrepancy between two data owing to the difference of cross sections in the nuclear reaction models. The dose conversion coefficients of effective dose equivalents for high energy radiations based on Q-L relation in ICRP Publication 60 were evaluated only in this work. The previous comparison between effective dose and effective dose equivalent made it clear that the radiation weighting factors for high energy neutrons and protons were overestimated and the modification was required. (author)

  7. 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.

  8. Structural Intervention With School Nurses Increases Receipt of Sexual Health Care Among Male High School Students.

    Science.gov (United States)

    Dittus, Patricia J; Harper, Christopher R; Becasen, Jeffrey S; Donatello, Robin A; Ethier, Kathleen A

    2018-01-01

    Adolescent males are less likely to receive health care and have lower levels of sexual and reproductive health (SRH) knowledge than adolescent females. The purpose of this study was to determine if a school-based structural intervention focused on school nurses increases receipt of condoms and SRH information among male students. Interventions to improve student access to sexual and reproductive health care were implemented in six urban high schools with a matched set of comparison schools. Interventions included working with school nurses to improve access to sexual and reproductive health care, including the provision of condoms and information about pregnancy and sexually transmitted disease prevention and services. Intervention effects were assessed through five cross-sectional yearly surveys, and analyses include data from 13,740 male students. Nurses in intervention schools changed their interactions with male students who visited them for services, such that, among those who reported they went to the school nurse for any reason in the previous year, those in intervention schools reported significant increases in receipt of sexual health services over the course of the study compared with students in comparison schools. Further, these results translated into population-level effects. Among all male students surveyed, those in intervention schools were more likely than those in comparison schools to report increases in receipt of sexual health services from school nurses. With a minimal investment of resources, school nurses can become important sources of SRH information and condoms for male high school students. Published by Elsevier Inc.

  9. A behavioral comparison of male and female adults with high functioning autism spectrum conditions.

    Directory of Open Access Journals (Sweden)

    Meng-Chuan Lai

    Full Text Available Autism spectrum conditions (ASC affect more males than females in the general population. However, within ASC it is unclear if there are phenotypic sex differences. Testing for similarities and differences between the sexes is important not only for clinical assessment but also has implications for theories of typical sex differences and of autism. Using cognitive and behavioral measures, we investigated similarities and differences between the sexes in age- and IQ-matched adults with ASC (high-functioning autism or Asperger syndrome. Of the 83 (45 males and 38 females participants, 62 (33 males and 29 females met Autism Diagnostic Interview-Revised (ADI-R cut-off criteria for autism in childhood and were included in all subsequent analyses. The severity of childhood core autism symptoms did not differ between the sexes. Males and females also did not differ in self-reported empathy, systemizing, anxiety, depression, and obsessive-compulsive traits/symptoms or mentalizing performance. However, adult females with ASC showed more lifetime sensory symptoms (p = 0.036, fewer current socio-communication difficulties (p = 0.001, and more self-reported autistic traits (p = 0.012 than males. In addition, females with ASC who also had developmental language delay had lower current performance IQ than those without developmental language delay (p<0.001, a pattern not seen in males. The absence of typical sex differences in empathizing-systemizing profiles within the autism spectrum confirms a prediction from the extreme male brain theory. Behavioral sex differences within ASC may also reflect different developmental mechanisms between males and females with ASC. We discuss the importance of the superficially better socio-communication ability in adult females with ASC in terms of why females with ASC may more often go under-recognized, and receive their diagnosis later, than males.

  10. Chronic High Fat Diet Consumption Impairs Metabolic Health of Male Mice.

    Science.gov (United States)

    Morselli, Eugenia; Criollo, Alfredo; Rodriguez-Navas, Carlos; Clegg, Deborah J

    We show that chronic high fat diet (HFD) feeding affects the hypothalamus of male but not female mice. In our study we demonstrate that palmitic acid and sphingolipids accumulate in the central nervous system of HFD-fed males. Additionally, we show that HFD-feeding reduces proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) thus reducing estrogen receptor α (ERα) and driving hypothalamic inflammation in male but not female mice. Hypothalamic inflammation correlates with markers of metabolic dysregulation as indicated by dysregulation in glucose intolerance and myocardial function. Lastly, we demonstrate that there are blockages in mitophagy and lipophagy in hypothalamic tissues in males. Our data suggest there is a sexually dimorphic response to chronic HDF exposure, females; despite gaining the same amount of body weight following HFD-feeding, appear to be protected from the adverse metabolic effects of the HFD.

  11. Non-acute effects of different doses of 3, 4-methylenedioxymethamphetamine on spatial memory in the Morris water maze in Sprague-Dawley male rats

    Institute of Scientific and Technical Information of China (English)

    Sara Soleimani Asl; Mohammad Hassan Farhadi; Nasser Naghdi; Samira Choopani; Alireza Samzadeh-Kermani; Mehdi Mehdizadeh

    2011-01-01

    3, 4-methylenedioxymethamphetamine (MDMA; also known as 'ecstasy') has been shown to impair learning and spatial memory in adult and neonatal rats.Many studies have focused on the acute effects of MDMA on memory.In the present study, we intraperitoneally administered MDMA (0, 5, 10, 20 mg/kg) to adult male rats to investigate the effects of different doses on rat spatial memory in the Morris water maze, body temperature, and mortality, twice a day, for 7 successive days.The results indicated that MDMA impaired spatial memory dose-dependently, with the highest dose (20 mg/kg) exerting the strongest effects.In addition, MDMA also caused hyperthermia and increased mortality in rats.

  12. Perceptions of selected science careers by African American high school males

    Science.gov (United States)

    Ijames, Erika Denise

    Research indicates that internal and external factors such as role models, stereotypes, and pressures placed on African American males by their family and friends influence their perceptions of science careers (Assibey-Mensah, 1997; Hess & Leal, 1997; Jacobowitz, 1983; Maple & Stage, 1991; Thomas, 1989; Ware & Lee, 1988). The purpose of this research was to investigate the perceptions of African American high school males about selected science careers based on apparent internal and external factors. Two questions guided this research: (1) What are high school African American males' perceptions of science careers? (2) What influences high school African American males' perceptions of science careers? This research was based on a pilot study in which African American college males perceived a selection of science careers along racial and gender lines. The follow-up investigation was conducted at Rockriver High School in Acorn County, and the participants were three college-bound African American males. The decision to choose males was based on the concept of occupational niching along gender lines. In biology, niching is defined as the role of a particular species regarding space and reproduction, and its interactions with other factors. During the seven-week period of the students' senior year, they met with the researcher to discuss their perceptions of science careers. An ethnographic approach was used to allow a richer and thicker narrative to occur. Critical theory was used to describe and interpret the voices of the participants from a social perspective. The data collected were analyzed using a constant comparative analysis technique. The participants revealed role models, negative stereotypes, peer pressure, social pressures, and misconceptions as some of the factors that influenced their perceptions of science careers. Results of this research suggest that by dispelling the misconceptions, educators can positively influence the attitudes and perceptions of

  13. IN UTERO EXPOSURE TO THE FUNGICIDE PROCYMIDONE AND DIBUTYL PHTHALATE PRODUCE DOSE ADDITIVE DISRUPTIONS OF MALE RAT SEXUAL DIFFERENTIATION

    Science.gov (United States)

    Procymidone (PRO) and dibutyl phthalate (DBP) alter male rat sexual differentiation by disrupting the androgen-signaling pathway via distinctly different cellular mechanisms of toxicity. DBP inhibits fetal Leydig cell androgen production whereas PRO binds AR and blocks androgen a...

  14. Analysis of final products from the liquid alkanes radiolysis at low dose, low temperature and high dose rate

    International Nuclear Information System (INIS)

    Tilquin, B.; Doncker, J. de.

    1991-01-01

    Yields of final products (dimers) from the radiolysis of n-hexane and 2,3-dimethylbutane are studied by capillary chromatographic techniques for trace analysis. Reaction of intermediates with the products, the alkane molecules or impurities, is reduced by using low dose (1 kGy), low temperature (195 K) and high dose rate (LINAC). Temperature is the most important experiment variable; by reducing the temperature, reactions with significant activation energies do not compete with radical-radical termination reactions. Products from LINAC radiolysis provide information about active species (reactive fragment, allylic radical...) which deserve a more detailed examination by direct methods [fr

  15. Dose accumulation of multiple high dose rate prostate brachytherapy treatments in two commercially available image registration systems.

    Science.gov (United States)

    Poder, Joel; Yuen, Johnson; Howie, Andrew; Bece, Andrej; Bucci, Joseph

    2017-11-01

    The purpose of this study was to assess whether deformable image registration (DIR) is required for dose accumulation of multiple high dose rate prostate brachytherapy (HDRPBT) plans treated with the same catheter pattern on two different CT datasets. DIR was applied to 20 HDRPBT patients' planning CT images who received two treatment fractions on sequential days, on two different CT datasets, with the same implant. Quality of DIR in Velocity and MIM image registration systems was assessed by calculating the Dice Similarity Coefficient (DSC) and mean distance to agreement (MDA) for the prostate, urethra and rectum contours. Accumulated doses from each system were then calculated using the same DIR technique and dose volume histogram (DVH) parameters compared to manual addition with no DIR. The average DSC was found to be 0.83 (Velocity) and 0.84 (MIM), 0.80 (Velocity) and 0.80 (MIM), 0.80 (Velocity) and 0.81 (MIM), for the prostate, rectum and urethra contours, respectively. The average difference in calculated DVH parameters between the two systems using dose accumulation was less than 1%, and there was no statistically significant difference found between deformably accumulated doses in the two systems versus manual DVH addition with no DIR. Contour propagation using DIR in velocity and MIM was shown to be at least equivalent to inter-observer contouring variability on CT. The results also indicate that dose accumulation through manual addition of DVH parameters may be sufficient for HDRPBT treatments treated with the same catheter pattern on two different CT datasets. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  16. Organ dose conversion coefficients for voxel models of the reference male and female from idealized photon exposures

    International Nuclear Information System (INIS)

    Schlattl, H; Zankl, M; Petoussi-Henss, N

    2007-01-01

    A new series of organ equivalent dose conversion coefficients for whole body external photon exposure is presented for a standardized couple of human voxel models, called Rex and Regina. Irradiations from broad parallel beams in antero-posterior, postero-anterior, left- and right-side lateral directions as well as from a 360 deg. rotational source have been performed numerically by the Monte Carlo transport code EGSnrc. Dose conversion coefficients from an isotropically distributed source were computed, too. The voxel models Rex and Regina originating from real patient CT data comply in body and organ dimensions with the currently valid reference values given by the International Commission on Radiological Protection (ICRP) for the average Caucasian man and woman, respectively. While the equivalent dose conversion coefficients of many organs are in quite good agreement with the reference values of ICRP Publication 74, for some organs and certain geometries the discrepancies amount to 30% or more. Differences between the sexes are of the same order with mostly higher dose conversion coefficients in the smaller female model. However, much smaller deviations from the ICRP values are observed for the resulting effective dose conversion coefficients. With the still valid definition for the effective dose (ICRP Publication 60), the greatest change appears in lateral exposures with a decrease in the new models of at most 9%. However, when the modified definition of the effective dose as suggested by an ICRP draft is applied, the largest deviation from the current reference values is obtained in postero-anterior geometry with a reduction of the effective dose conversion coefficient by at most 12%

  17. Organ dose conversion coefficients for voxel models of the reference male and female from idealized photon exposures

    Science.gov (United States)

    Schlattl, H.; Zankl, M.; Petoussi-Henss, N.

    2007-04-01

    A new series of organ equivalent dose conversion coefficients for whole body external photon exposure is presented for a standardized couple of human voxel models, called Rex and Regina. Irradiations from broad parallel beams in antero-posterior, postero-anterior, left- and right-side lateral directions as well as from a 360° rotational source have been performed numerically by the Monte Carlo transport code EGSnrc. Dose conversion coefficients from an isotropically distributed source were computed, too. The voxel models Rex and Regina originating from real patient CT data comply in body and organ dimensions with the currently valid reference values given by the International Commission on Radiological Protection (ICRP) for the average Caucasian man and woman, respectively. While the equivalent dose conversion coefficients of many organs are in quite good agreement with the reference values of ICRP Publication 74, for some organs and certain geometries the discrepancies amount to 30% or more. Differences between the sexes are of the same order with mostly higher dose conversion coefficients in the smaller female model. However, much smaller deviations from the ICRP values are observed for the resulting effective dose conversion coefficients. With the still valid definition for the effective dose (ICRP Publication 60), the greatest change appears in lateral exposures with a decrease in the new models of at most 9%. However, when the modified definition of the effective dose as suggested by an ICRP draft is applied, the largest deviation from the current reference values is obtained in postero-anterior geometry with a reduction of the effective dose conversion coefficient by at most 12%.

  18. Effects of body habitus on internal radiation dose calculations using the 5-year-old anthropomorphic male models

    DEFF Research Database (Denmark)

    Xie, Tianwu; Kuster, Niels; Zaidi, Habib

    2017-01-01

    Xtended general purpose Monte Carlo transport code and calculated the absorbed dose and effective dose of five 18F-labelled radiotracers for children of various habitus. For most organs, the S-value of F-18 presents stronger statistical correlations with body weight, standing height and sitting height than BMI...... and SSR. The self-absorbed fraction and self-absorbed S-values of F-18 and the absorbed dose and effective dose of 18F-labelled radiotracers present with the strongest statistical correlations with body weight. For 18F-Amino acids, 18F-Brain receptor substances, 18F-FDG, 18F-L-DOPA and 18F-FBPA, the mean...... absolute effective dose differences between phantoms of different habitus and fixed reference models are 11.4%, 11.3%, 10.8%, 13.3% and 11.4%, respectively. Total body weight, standing height and sitting height have considerable effects on human internal dosimetry. Radiation dose calculations...

  19. Development of a program for calculation of second dose and securities in brachytherapy high dose rate

    International Nuclear Information System (INIS)

    Esteve Sanchez, S.; Martinez Albaladejo, M.; Garcia Fuentes, J. D.; Bejar Navarro, M. J.; Capuz Suarez, B.; Moris de Pablos, R.; Colmenares Fernandez, R.

    2015-01-01

    We assessed the reliability of the program with 80 patients in the usual points of prescription of each pathology. The average error of the calculation points is less than 0.3% in 95% of cases, finding the major differences in the axes of the applicators (maximum error -0.798%). The program has proved effective previously testing him with erroneous dosimetry. Thanks to the implementation of this program is achieved by the calculation of the dose and part of the process of quality assurance program in a few minutes, highlighting the case of HDR prostate due to having a limited time. Having separate data sheet allows each institution to its protocols modify parameters. (Author)

  20. Radiation exposure for 'caregivers' during high-dose outpatient radioiodine therapy

    International Nuclear Information System (INIS)

    Marriott, C. J.; Webber, C. E.; Gulenchyn, K. Y.

    2007-01-01

    On 27 occasions, radiation doses were measured for a family member designated as the 'caregiver' for a patient receiving high-dose radioiodine outpatient therapy for differentiated thyroid carcinoma. For 25 of the administrations, patients received 3.7 GBq of 131 I. Radiation doses for the designated caregivers were monitored on an hourly basis for 1 week using electronic personal dosemeters. The average penetrating dose was 98±64 μSv. The maximum penetrating dose was 283 μSv. Measured dose rate profiles showed that, on average, one-third of the caregiver dose was received during the journey home from hospital. The mean dose rate profile showed rapid clearance of 131 I with three distinct phases. The corresponding clearance half-times were 131 I contaminating the home. (authors)

  1. The development of radiocaries after high-dose irradiation

    International Nuclear Information System (INIS)

    Willich, N.; Gundacker, K.; Rohloff, R.

    1988-01-01

    39 patients, who were irradiated with doses of 50 to 70 Gy for ENT-tumors over a period of 3.5 months to three years prior to the examination, showed a rapidly progressing caries of the teeth inside the target volume. The teeth outside the target volume developed a caries of less extent. Radiation induced xerostomia, effects of the irradiation of the soft tissues, nutrition habits and hygienics are discussed as causes for the damage of the teeth. (orig.) [de

  2. The Psychosocial Factors Contributing to the Underrepresentation of African American Males in Advanced High School Mathematics Courses

    Science.gov (United States)

    Rowlett, Joel Everett

    2013-01-01

    This case study examined the beliefs of African American males on the psychosocial and pedagogical factors contributing to the underrepresentation of African American males in advanced high school math courses. Six 11th grade African American male juniors from a large, comprehensive, Southeastern high school served as individual cases. Within- and…

  3. A profile of sexually active male adolescent high school students in Lima, Peru

    Directory of Open Access Journals (Sweden)

    Chirinos Jesús L.

    2000-01-01

    Full Text Available To document knowledge and attitudes regarding sexuality and sexual practices of male adolescent high school students in Lima, Peru, a self-administered, anonymous survey was completed by 991 male adolescents aged 12-19 as part of a School-Based Sex Education Intervention model. Questions concerned sociodemographic information; family characteristics; personal activities; knowledge and attitudes regarding sexuality; sexual experience; and contraceptive use. Knowledge related to sexuality was limited. Males tended to mainly discuss sexuality with their male peers (49.8%. Attitudes towards sexual activity and condom use were largely positive, although some males expressed ambivalent feelings towards the latter. Of the sample, 43% had ever had sex; age at first sexual intercourse was 13 years. While 88% of the sample would use condoms, 74% also gave reasons for not using them. Sexual activity was related to age, ever having repeated a grade, living with only one parent or in a mixed family, activities such as going to parties, use of alcohol, tobacco, and drugs, and viewing pornographic videos or magazines. Many male adolescents were at risk of causing an unintended pregnancy or acquiring an STD.

  4. High dose rate 192Ir calibration: Indonesia experiences

    International Nuclear Information System (INIS)

    Nasukha; Tjiptanto, D.; Darmasyah, R.; Kurniawan, B.

    2002-01-01

    Indonesia with a population of more than 200 Million people which spread on about 5000 islands, up to now only has 23 radiotherapy centers and some not active anymore. As mention by Parkin et al that Cervix/Utery and breast cancer are the most estimated numbers of new cases of cancers in women for developing countries, stomach and lung cancers in men. Indonesia as a developing country is likely similar to other developing countries on numbers of new cases of cancers in women. But quite different in men, in Indonesia the most common cancers are nasopharynx and thyroid cancers. The use of lr-192 sources in high dose-rate (HDR) remotely afterloaded brachytherapy treatments have greatly increased in recent years and variety of such sources are commercially available. Nine radiotherapy centers in Indonesia installed Nucletron microSelectron HDR remote afterloader. Based on the data of CiptoMangunkusurno Hospital, Jakarta that the most common cancers are the cervix, breast, nasopharynx and thyroid cancers which of percentage are about 31%, 25 %, 13%, and 6 % respectively. It means that the use of HDR 192 Ir brachytherapy has to be an effective tool in the treatments. Two methods have been studied and applied to calibrate HDR 192 Ir brachytherapy in Indonesia, especially for Nucletron microSelectron HDR 192 lr remote afterloader brachytherapy. Calibration of HDR 192 Ir brachytherapy source has been done by Cavity lonization Chamber and with Well Type lonization Chamber. First, 0.6 cc of NE Farmer type dosimeter that was calibrated to 60 Co and 250 kV of x-rays in air kerma was used in this experiment. Position of measurement (detector and source) at the center of the room and about 1 meter from the floor. Eight variation of distances from 10 cm to 40 cms have been carried out measurement as recommended by IAEA-TECDOC-1079. Correction have been given for scatters, non-uniformity, and attenuation. To solve the problem of scatter correction factor was used Matlab programming

  5. Dramatic response to high-dose icotinib in a lung adenocarcinoma patient after erlotinib failure.

    Science.gov (United States)

    Guan, Yin; Zhao, Hong; Meng, Jing; Yan, Xiang; Jiao, ShunChang

    2014-02-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) retreatment is rarely administered for non-small cell lung cancer (NSCLC) patients who did not respond to previous TKI treatment. A high dose of TKI may overcome resistance to the standard dose of TKI and have different effectiveness toward cancer compared with the standard dose of TKI. This manuscript describes a dramatic and durable response to high-dose icotinib in a NSCLC patient who did not respond to a previous standard dose of erlotinib. The treatment extended the life of the patient for one additional year. A higher dose of icotinib deserves further study not only for patients whose therapy failed with the standard dose of TKI but also for newly diagnosed NSCLC patients with a sensitive mutation. Serial mutation testing during disease development is necessary for analysis and evaluation of EGFR TKI treatment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Transperineal high-dose-rate interstitial radiation therapy in the management of gynecologic malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Itami, Jun; Hara, Ryuseke; Kozuka, Takuyou; Yamashita, Hideomi; Nakajima, Kaori; Shibata, Kouji; Abe, Yoshihisa; Fuse, Masashi; Ito, Masashi [International Medical Center of Japan, Tokyo (Japan). Dept. of Radiation Therapy and Oncology

    2003-11-01

    Background: High-dose-rate interstitial radiation therapy is a newly introduced modality, and its role in the management of gynecologic malignancies remains to be studied. Clinical experience in high-dose-rate interstitial radiation therapy was retrospectively investigated. Patients and Methods: Eight patients with primary and nine with recurrent gynecologic malignancies underwent high-dose-rate interstitial radiation therapy with/without external-beam irradiation. Fractional dose of the high-dose-rate interstitial radiation therapy ranged between 4 and 6 Gy with total doses of 15-54 Gy. Interstitial irradiation was performed twice daily with an interval of > 6 h. Results: 2-year local control rate was 75% for primary treatment and 47% for treatment of recurrence (p = 0.46). Maximum tumor size had a statistically significant impact on local control (p < 0.002). Grade 2 and 4 late complications were seen in five patients, and the incidence was significantly higher in patients with a larger volume enclosed by the prescribed fractional dose of high-dose-rate interstitial radiation therapy. The incidence of grade 2 and 4 complications at 18 months was 78% and 0% with a volume > 100 cm{sup 3} and {<=} 100 cm{sup 3}, respectively (p < 0.04). Conclusion: Although high-dose-rate interstitial radiation therapy is a promising modality, it must be applied cautiously to patients with bulky tumors because of the high incidence of serious complications. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

  8. The Role of High Dose Interleukin-2 in the Era of Targeted Therapy.

    Science.gov (United States)

    Gills, Jessie; Parker, William P; Pate, Scott; Niu, Sida; Van Veldhuizen, Peter; Mirza, Moben; Holzbeierlein, Jeffery M; Lee, Eugene K

    2017-09-01

    We assessed survival outcomes following high dose interleukin-2 in a contemporary cohort of patients during the era of targeted agents. We retrospectively reviewed the records of patients with metastatic renal cell carcinoma treated with high dose interleukin-2 between July 2007 and September 2014. Clinicopathological data were abstracted and patient response to therapy was based on RECIST (Response Evaluation Criteria In Solid Tumors), version 1.1 criteria. The Kaplan-Meier method was used to estimate progression-free and overall survival in the entire cohort, the response to high dose interleukin-2 in regard to previous targeted agent therapy and the response to the targeted agent in relation to the response to high dose interleukin-2. We identified 92 patients, of whom 87 had documentation of a response to high dose interleukin-2. Median overall survival was 34.4 months from the initiation of high dose interleukin-2 therapy in the entire cohort. Patients who received targeted therapy before high dose interleukin-2 had overall survival (median 34.4 and 30.0 months, p = 0.88) and progression-free survival (median 1.5 and 1.7 months, p = 0.8) similar to those in patients who received no prior therapy, respectively. Additionally, patients with a complete or partial response to high dose interleukin-2 had similar outcomes for subsequent targeted agents compared to patients whose best response was stable or progressive disease (median overall survival 30.1 vs 25.4 months, p = 0.4). Our data demonstrate that patient responses to high dose interleukin-2 and to targeted agents before and after receiving high dose interleukin-2 are independent. As such, carefully selected patients should be offered high dose interleukin-2 for the possibility of a complete and durable response without the fear of limiting the treatment benefit of targeted agents. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  9. Moderate- vs high-dose methadone in the treatment of opioid dependence: a randomized trial.

    Science.gov (United States)

    Strain, E C; Bigelow, G E; Liebson, I A; Stitzer, M L

    1999-03-17

    Methadone hydrochloride treatment is the most common pharmacological intervention for opioid dependence, and recent interest has focused on expanding methadone treatment availability beyond traditional specially licensed clinics. However, despite recommendations regarding effective dosing of methadone, controlled clinical trials of higher-dose methadone have not been conducted. To compare the relative clinical efficacy of moderate- vs high-dose methadone in the treatment of opioid dependence. A 40-week randomized, double-blind clinical trial starting in June 1992 and ending in October 1995. Outpatient substance abuse treatment research clinic at the Johns Hopkins University Bayview Campus, Baltimore, Md. One hundred ninety-two eligible clinic patients. Daily oral methadone hydrochloride in the dose range of 40 to 50 mg (n = 97) or 80 to 100 mg (n = 95), with concurrent substance abuse counseling. Opioid-positive urinalysis results and retention in treatment. By intent-to-treat analysis through week 30 patients in the high-dose group had significantly lower rates of opioid-positive urine samples compared with patients in the moderate-dose group (53.0% [95% confidence interval [CI], 46.9%-59.2%] vs 61.9% [95% CI, 55.9%-68.0%]; P = .047. These differences persisted during withdrawal from methadone. Through day 210 no significant difference was evident between dose groups in treatment retention (high-dose group mean retention, 159 days; moderate-dose group mean retention, 157 days). Nineteen (33%) of 57 patients in the high-dose group and 11 (20%) of 54 patients in the moderate-dose group completed detoxification. Both moderate- and high-dose methadone treatment resulted in decreased illicit opioid use during methadone maintenance and detoxification. The high-dose group had significantly greater decreases in illicit opioid use.

  10. Variable effects of high-dose adrenaline relative to standard-dose adrenaline on resuscitation outcomes according to cardiac arrest duration.

    Science.gov (United States)

    Jeung, Kyung Woon; Ryu, Hyun Ho; Song, Kyung Hwan; Lee, Byung Kook; Lee, Hyoung Youn; Heo, Tag; Min, Yong Il

    2011-07-01

    Adjustment of adrenaline (epinephrine) dosage according to cardiac arrest (CA) duration, rather than administering the same dose, may theoretically improve resuscitation outcomes. We evaluated variable effects of high-dose adrenaline (HDA) relative to standard-dose adrenaline (SDA) on resuscitation outcomes according to CA duration. Twenty-eight male domestic pigs were randomised to the following 4 groups according to the dosage of adrenaline (SDA 0.02 mg/kg vs. HDA 0.2mg/kg) and duration of CA before beginning cardiopulmonary resuscitation (CPR): 6 min SDA, 6 min HDA, 13 min SDA, or 13 min HDA. After the predetermined duration of untreated ventricular fibrillation, CPR was provided. All animals in the 6 min SDA, 6 min HDA, and 13 min HDA groups were successfully resuscitated, while only 4 of 7 pigs in the 13 min SDA group were successfully resuscitated (p=0.043). HDA groups showed higher right atrial pressure, more frequent ventricular ectopic beats, higher blood glucose, higher troponin-I, and more severe metabolic acidosis than SDA groups. Animals of 13 min groups showed more severe metabolic acidosis and higher troponin-I than animals of 6 min groups. All successfully resuscitated animals, except two animals in the 13 min HDA group, survived for 7 days (p=0.121). Neurologic deficit score was not affected by the dose of adrenaline. HDA showed benefit in achieving restoration of spontaneous circulation in 13 min CA, when compared with 6 min CA. However, this benefit did not translate into improved long-term survival or neurologic outcome. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  11. Genotoxic effects of high dose rate X-ray and low dose rate gamma radiation in ApcMin/+ mice.

    Science.gov (United States)

    Graupner, Anne; Eide, Dag M; Brede, Dag A; Ellender, Michele; Lindbo Hansen, Elisabeth; Oughton, Deborah H; Bouffler, Simon D; Brunborg, Gunnar; Olsen, Ann Karin

    2017-10-01

    Risk estimates for radiation-induced cancer in humans are based on epidemiological data largely drawn from the Japanese atomic bomb survivor studies, which received an acute high dose rate (HDR) ionising radiation. Limited knowledge exists about the effects of chronic low dose rate (LDR) exposure, particularly with respect to the application of the dose and dose rate effectiveness factor. As part of a study to investigate the development of colon cancer following chronic LDR vs. acute HDR radiation, this study presents the results of genotoxic effects in blood of exposed mice. CBAB6 F1 Apc +/+ (wild type) and Apc Min/+ mice were chronically exposed to estimated whole body absorbed doses of 1.7 or 3.2 Gy 60 Co-γ-rays at a LDR (2.2 mGy h -1 ) or acutely exposed to 2.6 Gy HDR X-rays (1.3 Gy min -1 ). Genotoxic endpoints assessed in blood included chromosomal damage (flow cytometry based micronuclei (MN) assay), mutation analyses (Pig-a gene mutation assay), and levels of DNA lesions (Comet assay, single-strand breaks (ssb), alkali labile sites (als), oxidized DNA bases). Ionising radiation (ca. 3 Gy) induced genotoxic effects dependent on the dose rate. Chromosomal aberrations (MN assay) increased 3- and 10-fold after chronic LDR and acute HDR, respectively. Phenotypic mutation frequencies as well as DNA lesions (ssb/als) were modulated after acute HDR but not after chronic LDR. The Apc Min/+ genotype did not influence the outcome in any of the investigated endpoints. The results herein will add to the scant data available on genotoxic effects following chronic LDR of ionising radiation. Environ. Mol. Mutagen. 58:560-569, 2017. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.

  12. Effects of low dose gamma radiation on the early growth of red pepper and the resistance to subsquent high dose of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. S.; Baek, M. H.; Kim, D. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

    2001-05-01

    Red pepper (capsicum annuum L. cv. Jokwang and cv. Johong) seeds were irradiated with the dose of 0{approx}50 Gy to investigated the effect of the low dose gamma radiation on the early growth and resistance to subsequent high dose of radiation. The effect of the low dose gamma radiation on the early growth and resistance to subsequenct high dose of radiation were enhanced in Johong cultivar but not in Jokwang cultivar. Germination rate and early growth of Johong cultivar were noticeably increased at 4 Gy-, 8 Gy- and 20 Gy irradiation group. Resistance to subsequent high dose of radiation of Johong cultivar were increased at almost all of the low dose irradiation group. Especially it was highest at 4 Gy irradiation group. The carotenoid contents and enzyme activity on the resistance to subsequent high dose of radiation of Johong cultivar were increased at the 4 Gy and 8 Gy irradiation group.

  13. Pharmacokinetics of Imipenem/Cilastatin Burn Intensive Care Unit Patients Undergoing High-Dose Continuous Venovenous Hemofiltration.

    Science.gov (United States)

    Boucher, Bradley A; Hudson, Joanna Q; Hill, David M; Swanson, Joseph M; Wood, G Christopher; Laizure, S Casey; Arnold-Ross, Angela; Hu, Zhe-Yi; Hickerson, William L

    2016-12-01

    High-dose continuous venovenous hemofiltration (CVVH) is a continuous renal replacement therapy (CRRT) used frequently in patients with burns. However, antibiotic dosing is based on inference from studies assessing substantially different methods of CRRT. To address this knowledge gap for imipenem/cilastatin (I/C), we evaluated the systemic and extracorporeal clearances (CLs) of I/C in patients with burns undergoing high-dose CVVH. Prospective clinical pharmacokinetic study. Ten adult patients with burns receiving I/C for a documented infection and requiring high-dose CVVH were studied. Blood and effluent samples for analysis of I/C concentrations were collected for up to 6 hours after the I/C infusion for calculation of I/C total CL (CL T otal ), CL by CVVH (CL HF ), half-life during CVVH, volume of distribution at steady state (Vd ss ), and the percentage of drug eliminated by CVVH. In this patient sample, the mean age was 50 ± 17 years, total body surface area burns was 23 ± 27%, and 80% were male. Nine patients were treated with high-dose CVVH for acute kidney injury and one patient for sepsis. The mean delivered CVVH dose was 52 ± 14 ml/kg/hour (range 32-74 ml/kg/hr). The imipenem CL HF was 3.27 ± 0.48 L/hour, which accounted for 23 ± 4% of the CL T otal (14.74 ± 4.75 L/hr). Cilastatin CL HF was 1.98 ± 0.56 L/hour, which accounted for 45 ± 19% of the CL T otal (5.16 + 2.44 L/hr). The imipenem and cilastatin half-lives were 1.77 ± 0.38 hours and 4.21 ± 2.31 hours, respectively. Imipenem and cilastatin Vd ss were 35.1 ± 10.3 and 32.8 ± 13.8 L, respectively. Efficient removal of I/C by high-dose CVVH, a high overall clearance, and a high volume of distribution in burn intensive care unit patients undergoing this CRRT method warrant aggressive dosing to treat serious infections effectively depending on the infection site and/or pathogen. © 2016 Pharmacotherapy Publications, Inc.

  14. The Gender Role Perceptions of Male Students at a Prestigious, Single-Gender, Catholic High School

    Science.gov (United States)

    Thompson, Franklin T.; Austin, William P.

    2010-01-01

    This study utilized a data set of categorical responses measuring the gender role views of students (N = 701) from a prestigious, Midwestern, all-male, Catholic high school. Incongruence between student self-perceptions and the realities of gender role miseducation and the embracement of sexist ideology were readily apparent. Findings suggest that…

  15. Influence of Mentoring on African American and Hispanic Males in High School

    Science.gov (United States)

    Smith, Jacqueline A.

    2016-01-01

    The mixed method research study was designed to evaluate the effects on a mentoring initiative on 40 African American and Hispanic males in an urban high school. The study took place over a three-month period in a traditional public school with 2,000 students. Data collection methods used included individual interview with student mentees, surveys…

  16. When Police Intervene: Race, Gender, and Discipline of Black Male Students at an Urban High School

    Science.gov (United States)

    Hines-Datiri, Dorothy

    2015-01-01

    Courtney and Dennis, two African American male students at McDowell High, were arrested at school for throwing water balloons during senior prank week. The principal assigned two police officers to the magnet school to oversee the implementation of a new discipline protocol. However, several members of the school staff were ill-informed about the…

  17. Conjoint moderate or high risk alcohol and tobacco use among male out-patients in Thailand

    Directory of Open Access Journals (Sweden)

    Supa Pengpid

    2016-03-01

    Full Text Available Objective: To better understand conjoint alcohol and tobacco use among male hospital out-patients, the purposes of this study were: (1 to assess the prevalence of conjoint use and (2 to determine the factors associated with the conjoint alcohol use and tobacco use. Methods: In a cross-sectional survey, consecutive male out-patients from four district hospitals in Nakhon Pathom province in Thailand were assessed with the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST, Hospital Anxiety and Depression Scale (HADS, selfreported chronic conditions and health-seeking behaviour. The sample included 2208 study participants, with a mean age of 36.2 years (SD = 11.7 and an age range of 18–60 years. Results: Overall, 34.5% of the male hospital out-patients were conjoint moderate or high-risk alcohol and tobacco users, and 31.1% were moderate or high-risk alcohol or tobacco users. In multivariate analysis, younger age, having primary or less education, being separated, divorced or widowed, not having diabetes and not being obese were associated with conjoint moderate or high-risk alcohol and tobacco use. Conclusion: High prevalence and several risk factors of conjoint alcohol and tobacco use were found among hospital male out-patients. The findings of this study call for dual-intervention approaches for both alcohol and tobacco.

  18. The Effects of Home-School Dissonance on African American Male High School Students

    Science.gov (United States)

    Brown-Wright, Lynda; Tyler, Kenneth Maurice

    2010-01-01

    The current study examined associations between home-school dissonance and several academic and psychological variables among 80 African American male high school students. Regression analyses revealed that home-school dissonance significantly predicted multiple academic and psychological variables, including amotivation, academic cheating,…

  19. The neuropsychology of male adults with high-functioning autism or Asperger syndrome

    NARCIS (Netherlands)

    Wilson, C.E.; Happé, F.; Wheelwright, S.J.; Ecker, C.; Lombardo, M.V.; Johnston, P.; Daly, E.; Murphy, C.M.; Spain, D.; Lai, M-C.; Chakrabarti, B; Sauter, D.A.; MRC AIMS Consortium, [Unknown; Baron-Cohen, S.; Murphy, D.G.M.

    2014-01-01

    Autism Spectrum Disorder (ASD) is diagnosed on the basis of behavioral symptoms, but cognitive abilities may also be useful in characterizing individuals with ASD. One hundred seventy-eight high-functioning male adults, half with ASD and half without, completed tasks assessing IQ, a broad range of

  20. The clinical pharmacology of alkylating agents in high-dose chemotherapy

    NARCIS (Netherlands)

    Huitema, A. D.; Smits, K. D.; Mathôt, R. A.; Schellens, J. H.; Rodenhuis, S.; Beijnen, J. H.

    2000-01-01

    Alkylating agents are widely used in high-dose chemotherapy regimens in combination with hematological support. Knowledge about the pharmacokinetics and pharmacodynamics of these agents administered in high doses is critical for the safe and efficient use of these regimens. The aim of this review is

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

    Directory of Open Access Journals (Sweden)

    Moride Yola

    2001-11-01

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

  2. Risks Associated with High-Dose Lactobacillus rhamnosus in an Escherichia coli Model of Piglet Diarrhoea

    DEFF Research Database (Denmark)

    Li, Xiao-Qiong; Zhu, Yao-Hong; Zhang, Hong-Fu

    2012-01-01

    might be more effective than a high dose at ameliorating diarrhoea. There is a risk that high-dose L. rhamnosus pretreatment may negate the preventative effects, thus decreasing the prophylactic benefits against potential enteric pathogens. Our data suggest a safe threshold for preventative use...

  3. Characterization of Radiation Hardened Bipolar Linear Devices for High Total Dose Missions

    Science.gov (United States)

    McClure, Steven S.; Harris, Richard D.; Rax, Bernard G.; Thorbourn, Dennis O.

    2012-01-01

    Radiation hardened linear devices are characterized for performance in combined total dose and displacement damage environments for a mission scenario with a high radiation level. Performance at low and high dose rate for both biased and unbiased conditions is compared and the impact to hardness assurance methodology is discussed.

  4. An Open-label, Single-dose, Pharmacokinetic Study of Factor VIII Activity After Administration of Moroctocog Alfa (AF-CC) in Male Chinese Patients With Hemophilia A.

    Science.gov (United States)

    Liu, Hongzhong; Wu, Runhui; Hu, Pei; Sun, Feifei; Xu, Lihong; Liang, Yali; Nepal, Sunil; Qu, Peng Roger; Huard, Francois; Korth-Bradley, Joan M

    2017-07-01

    Hemophilia A represents up to 80% of all hemophilia cases in China. In patients with this condition, bleeding can be prevented and controlled by administering clotting factor VIII (FVIII). Since their initial availability, recombinant FVIII products have undergone several iterations to enhance their safety. Moroctocog alfa albumin-free cell culture (AF-CC) is among the third generation of recombinant FVIII products and received regulatory approval in China in August 2012. The present study characterizes the single-dose pharmacokinetic parameters of FVIII activity (FVIII:C) after administration of moroctocog alfa (AF-CC) in male Chinese patients with hemophilia A. This multicenter, open-label, single-dose study enrolled 13 male Chinese patients diagnosed with severe hemophilia A (FVIII:C hemophilia A. The pharmacokinetic profile in older patients was similar to that previously reported with recombinant FVIII products in studies with a predominantly white population; younger patients had reduced exposure to FVIII:C. The single doses of moroctocog alfa (AF-CC) were well tolerated; 2 cases of transient, low-titer FVIII inhibitor development were observed. ClinicalTrials.gov identifier: NCT02461992. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

  5. Radiotherapy high energy surface dose measurements: effects of chamber polarity

    International Nuclear Information System (INIS)

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

    2004-01-01

    Full text: The effects of chamber polarity have been investigated for the measurement of 6MV and 18MV x-ray surface dose using a parallel plate ionization chamber. Results have shown that a significant difference in measured ionization is recorded between to polarities at 6MV and 18MV at the phantom surface. A polarity ratio ranging from 1 062 to 1 005 is seen for 6MV x-rays at the phantom surface for field sizes 5cm x 5cm to 40cm x 40cm when comparing positive to negative polarity. These ratios range from 1.024 to 1.004 for 18MV x-rays with the same field sizes. When these charge reading are compared to the D max readings of the same polarity it is found that these polarity effects are minimal for the calculation of percentage dose results with variations being less than 1% of maximum. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  6. Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

    International Nuclear Information System (INIS)

    Jeong, Shin Young; Lee, Jaetae

    2010-01-01

    Radioactive iodine ( 131 I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, 131 I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the 131 I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of 131 I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of 131 I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with 131 I-induced sialadenitis that is unresponsive to medical treatment.

  7. Radiation Sialadenitis Induced by High-dose Radioactive Iodine Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Shin Young; Lee, Jaetae [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2010-06-15

    Radioactive iodine ({sup 131}I) is accumulated in the thyroid tissue and plays an important role in the treatment of differentiated papillary and follicular cancers after thyroidectomy. Simultaneously, {sup 131}I is concentrated in the salivary glands and secreted into the saliva. Dose-related damage to the salivary parenchyma results from the {sup 131}I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of {sup 131}I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, candidiasis, and neoplasia. Prevention of {sup 131}I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration. Recently interventional sialoendoscopy has been introduced an effective tool for the management of patients with {sup 131}I-induced sialadenitis that is unresponsive to medical treatment.

  8. Fast, three-dimensional, MR Imaging for polymer gel dosimetric applications involving high dose and steep dose gradients

    International Nuclear Information System (INIS)

    Sandilos, Panagiotis; Baras, Panagiotis; Georgiou, Evangelos; Dardoufas, Konstantinos; Karaiskos, Pantelis; Papagiannis, Panagiotis; Paschalis, Theodoros; Tatsis, Elias; Torrens, Michael; Vlahos, Lampros

    2006-01-01

    Polymer gels constitute water equivalent integrating detectors, which, combined with magnetic resonance imaging (MRI), can provide accurate three dimensional (3D) dose distributions in contemporary radiotherapy applications where the small field dimensions and steep dose gradients induce limitations to conventional dosimeters. One of the main obstacles for adapting the method for routine use in the clinical setting is the cost effectiveness of the MRI readout method. Currently, optimized Carr-Purcell-Meiboom-Gill (CPMG) multiple spin echo imaging pulse sequences are commonly used which however result in long imaging times. This work evaluates the efficiency of 3D, dual-echo, k-space segmented turbo spin echo (TSE) scanning sequences for accurate dosimetry with sub-millimetre spatial resolution in strenuous radiation therapy applications. PABIG polymer gel dosimeters were irradiated with an 192 Ir High Dose Rate brachytherapy source, the 4 mm and 8 mm collimator helmets of a gamma knife unit and a custom made x-knife collimator of 1 cm diameter. Profile and dose distribution measurements using TSE are benchmarked against corresponding findings obtained by the commonly used, but time consuming, CPMG sequence as well as treatment planning calculations, Monte Carlo (MC) simulations and film measurements. The implementation of a high Turbo factor was found to provide comparable accuracy, allowing a 64-fold MRI scan acceleration compared to conventional multi-echo sequences. The availability of TSE sequences in typical MRI installations greatly facilitates the introduction of polymer gel dosimetry in the clinical environment as a practicable tool for the determination of full 3D dose distributions in contemporary radiotherapy applications

  9. Fast, three-dimensional, MR Imaging for polymer gel dosimetric applications involving high dose and steep dose gradients

    Energy Technology Data Exchange (ETDEWEB)

    Sandilos, Panagiotis [Department of Radiology, Medical School, University of Athens, Areteion Hospital, 76 Vas. Sofias Ave., 115 28 Athens (Greece); Baras, Panagiotis [Philips Hellas Medical Systems, 44 Kifissias Ave., Maroussi 151 25, Athens (Greece); Georgiou, Evangelos [Medical Physics Department, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece); Dardoufas, Konstantinos [Department of Radiology, Medical School, University of Athens, Areteion Hospital, 76 Vas. Sofias Ave., 115 28 Athens (Greece): Hygeia Hospital, Kiffisias Avenue and 4 Erythrou Stavrou, Marousi, 151 23 Athens (Greece); Karaiskos, Pantelis [Medical Physics Department, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece): Hygeia Hospital, Kiffisias Avenue and 4 Erythrou Stavrou, Marousi, 151 23 Athens (Greece)]. E-mail: p.karaiskos@hygeia.gr; Papagiannis, Panagiotis [Physics Department, Nuclear and Particle Physics Section, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece); Paschalis, Theodoros [Department of Radiology, Medical School, University of Athens, Areteion Hospital, 76 Vas. Sofias Ave., 115 28 Athens (Greece); Tatsis, Elias [Department of Radiology, Medical School, University of Athens, Areteion Hospital, 76 Vas. Sofias Ave., 115 28 Athens (Greece); Torrens, Michael [Hygeia Hospital, Kiffisias Avenue and 4 Erythrou Stavrou, Marousi, 151 23 Athens (Greece); Vlahos, Lampros [Department of Radiology, Medical School, University of Athens, Areteion Hospital, 76 Vas. Sofias Ave., 115 28 Athens (Greece)

    2006-12-20

    Polymer gels constitute water equivalent integrating detectors, which, combined with magnetic resonance imaging (MRI), can provide accurate three dimensional (3D) dose distributions in contemporary radiotherapy applications where the small field dimensions and steep dose gradients induce limitations to conventional dosimeters. One of the main obstacles for adapting the method for routine use in the clinical setting is the cost effectiveness of the MRI readout method. Currently, optimized Carr-Purcell-Meiboom-Gill (CPMG) multiple spin echo imaging pulse sequences are commonly used which however result in long imaging times. This work evaluates the efficiency of 3D, dual-echo, k-space segmented turbo spin echo (TSE) scanning sequences for accurate dosimetry with sub-millimetre spatial resolution in strenuous radiation therapy applications. PABIG polymer gel dosimeters were irradiated with an {sup 192}Ir High Dose Rate brachytherapy source, the 4 mm and 8 mm collimator helmets of a gamma knife unit and a custom made x-knife collimator of 1 cm diameter. Profile and dose distribution measurements using TSE are benchmarked against corresponding findings obtained by the commonly used, but time consuming, CPMG sequence as well as treatment planning calculations, Monte Carlo (MC) simulations and film measurements. The implementation of a high Turbo factor was found to provide comparable accuracy, allowing a 64-fold MRI scan acceleration compared to conventional multi-echo sequences. The availability of TSE sequences in typical MRI installations greatly facilitates the introduction of polymer gel dosimetry in the clinical environment as a practicable tool for the determination of full 3D dose distributions in contemporary radiotherapy applications.

  10. A blinded, randomized, controlled trial of three doses of high-dose insulin in poison-induced cardiogenic shock.

    Science.gov (United States)

    Cole, J B; Stellpflug, S J; Ellsworth, H; Anderson, C P; Adams, A B; Engebretsen, K M; Holger, J S

    2013-05-01

    High dose insulin (HDI) has proven superior to glucagon and catecholamines in the treatment of poison-induced cardiogenic shock (PICS) in previous animal studies. Standard recommendations for dosing of insulin vary and the optimal dose of HDI in PICS has not been established. Our hypothesis was a dose of 10 U/kg/hr of HDI would be superior to 1 U/kg/hr with cardiac output (CO) as our primary outcome measure in pigs with propranolol-induced PICS. This was a blinded, prospective, randomized trial with 4 arms consisting of 4 pigs in each arm. The arms were as follows: placebo (P), 1 U/kg/hr (HDI-1), 5 U/kg/hr (HDI-5), and 10 U/kg/hr (HDI-10). Cardiogenic shock was induced with a bolus of 0.5 mg/kg of propranolol followed by an infusion of 0.25 mg/kg/min until the point of toxicity, defined as 0.75 x (HR x MAP) was reached. At this point the propranolol infusion was decreased to 0.125 mg/kg/min and a 20 mL/kg bolus of normal saline (NS) was administered. The protocol was continued for 6 hours or until the animals died. 2 pigs died in the P arm, 1 pig died each in the HDI-1 and HDI-5 arms, and all pigs lived in the HDI-10 arm. There was a statistically significant difference in dose by time interaction on CO of 1.13 L/min over the 6 hr study period (p = < 0.001). There was also a statistically significant difference in dose by time interaction on MAP, HR, and systemic vascular resistance (SVR). No statistically significant difference was found between any of the arms regarding glucose utilization. HDI was statistically and clinically significantly superior to placebo in this propranolol model of PICS. Furthermore a dose response over time was found where CO increased corresponding to increases in doses of HDI.

  11. High dose vitamin D may improve lower urinary tract symptoms in postmenopausal women.

    Science.gov (United States)

    Oberg, Johanna; Verelst, Margareta; Jorde, Rolf; Cashman, Kevin; Grimnes, Guri

    2017-10-01

    Lower urinary tract symptoms (LUTS) are common in postmenopausal women, and have been reported inversely associated with vitamin D intake and serum 25-hydroxyvitamin D (25(OH)D) levels. The aim of this study was to investigate if high dose vitamin D supplementation would affect LUTS in comparison to standard dose. In a randomized controlled study including 297 postmenopausal women with low bone mineral density, the participants were allocated to receive capsules of 20 000IU of vitamin D 3 twice a week (high dose group) or similar looking placebo (standard dose group). In addition, all the participants received 1g of calcium and 800IU of vitamin D daily. A validated questionnaire regarding LUTS was filled in at baseline and after 12 months. At baseline, 76 women in the high dose group and 82 in the standard dose group reported any LUTS. Levels of serum 25(OH)D increased significantly more in the high dose group (from 64.7 to 164.1nmol/l compared to from 64.1 to 81.8nmol/l, p<0.01). No differences between the groups were seen regarding change in LUTS except for a statistically significant reduction in the reported severity of urine incontinence in the high dose group as compared to the standard dose group after one year (p<0.05). The results need confirmation in a study specifically designed for this purpose. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The Effects of Different Doses of Curcuma longa Aqueous Extract on Memory Retention and Retrieval in Male Mice

    Directory of Open Access Journals (Sweden)

    2016-12-01

    Full Text Available Background and Objectives: Curcumin belongs to ginger family, which is used as food and drug from ancient times. Different studies have shown beneficial effects of curcumin on peptic ulcer, rheumatoid arthritis, asthma, and various types of cancer. In this study, the effect of different doses of Curcuma longa aqueous extract on memory retention and retrieval of mice, was investigated using passive avoidance apparatus. Methods: Mice were divided into 6 groups of 8 each for memory retention test and 6 groups of 8 each for memory retrieval test {experimental groups receiving the extract intraperitoneally at doses of 100, 200, 400, 800mg/kg, blank group, and control group}. In memory retention test, the curcumin extract was administered immediately after electric shock, while in the memory retrieval test, it was administered 24 h after receiving electric shock. To compare the complete stepping in the experiment days, One-way ANOVA and post-test LSD were used. The level of significance was considered p<0.05. Results: In this study, curcuma longa aqueous extract significantly increased memory retention and retrieval on the 4th day compared to blank and control groups. The best response for memory retention was obtained at the dose of 100mg/kg and for memory retrieval at the dose of 200mg/kg. Conclusion: According to the results of this study, it seems that Curcuma longa aqueous extract improves memory retention and retrieval in healthy mice.  

  13. Comparisons of Perceived Training Doses in Champion Collegiate-Level Male and Female Cross-country Runners and Coaches over the Course of a Competitive Season.

    Science.gov (United States)

    Barnes, Kyle R

    2017-10-17

    Session rating of perceived exertion (sRPE) is a practical tool for coaches to assess internal training load of their athletes. In a sport like cross-country running, that is individual in nature, but has a team training and competition component, information about the association between external and internal load is lacking. Furthermore, there is a need for studies that examine perception of training doses across multiple training cycles including the competitive season as well as between male and female athletes. Session RPE, duration, and training load (TL RPE  = sRPE × duration) of 25 highly trained male and female cross-country runners and their coaches were recorded for every training session (110 days) throughout a collegiate cross-country season. Intensity (sRPE), duration, and TL RPE were compared between coaches and runners by gender separately. Training sessions were also analyzed by those intended by the coaches to be easy, moderate, and hard as well as by training period. Data from 3024 training sessions were collected, 62% of which were considered "easy," 18% "moderate," and 20% "hard." Men and women rated coach-intended easy sessions significantly harder during each month of the season (effect size (ES) > 2.9, p sessions significantly higher than coaches (ES ≥ 1.0, p ≤ 0.002), whereas females rated hard intensity sessions significantly lower than coaches (ES > 0.5, p sessions (ES  0.05) or females and coach's moderate sessions (ES  0.05). Training intensity and TL RPE tended to increase throughout the season (p > 0.05), with a significant increase in moderate and hard intensity sessions in the last training period (p training throughout the cross-country season. Given the success of the athletes in this study, these results show how a simple system for monitoring training such as the sRPE method may improve control of training variables and provide a useful tool for coaches to evaluate training load placed on

  14. Evaluation of Low- Versus High-dose Valganciclovir for Prevention of Cytomegalovirus Disease in High-risk Renal Transplant Recipients.

    Science.gov (United States)

    Gabardi, Steven; Asipenko, Natalya; Fleming, James; Lor, Kevin; McDevitt-Potter, Lisa; Mohammed, Anisa; Rogers, Christin; Tichy, Eric M; Weng, Renee; Lee, Ruth-Ann

    2015-07-01

    Despite proven efficacy of prolonged cytomegalovirus (CMV) prophylaxis using valganciclovir 900 mg/day, some centers use 450 mg/day due to reported success and cost savings. This multicenter, retrospective study compared the efficacy and safety of 6 months of low-dose versus high-dose valganciclovir prophylaxis in high-risk, donor-positive/recipient-negative, renal transplant recipients (RTR). Two hundred thirty-seven high-risk RTR (low-dose group = valganciclovir 450 mg/day [n = 130]; high-dose group = valganciclovir 900 mg/day [n = s7]) were evaluated for 1-year CMV disease prevalence. Breakthrough CMV, resistant CMV, biopsy-proven acute rejection (BPAR), graft loss, opportunistic infections (OI), new-onset diabetes after transplantation (NODAT), premature valganciclovir discontinuation, renal function and myelosuppression were also assessed. Patient demographics and transplant characteristics were comparable. Induction and maintenance immunosuppression were similar, except for more early steroid withdrawal in the high-dose group. Similar proportions of patients developed CMV disease (14.6% vs 24.3%; P = 0.068); however, controlling CMV risk factor differences through multivariate logistic regression revealed significantly lower CMV disease in the low-dose group (P = 0.02; odds ratio, 0.432, 95% confidence interval, 0.211-0.887). Breakthrough and resistant CMV occurred at similar frequencies. There was no difference in renal function or rates of biopsy-proven acute rejection, graft loss, opportunistic infections, or new-onset diabetes after transplantation. The high-dose group had significantly lower mean white blood cell counts at months 5 and 6; however, premature valganciclovir discontinuation rates were similar. Low-dose and high-dose valganciclovir regimens provide similar efficacy in preventing CMV disease in high-risk RTR, with a reduced incidence of leukopenia associated with the low-dose regimen and no difference in resistant CMV. Low-dose valganciclovir

  15. A Peer-Led High School Transition Program Increases Graduation Rates Among Latino Males.

    Science.gov (United States)

    Johnson, Valerie L; Simon, Patricia; Mun, Eun-Young

    2014-01-01

    The present study investigated the impact of a manualized high school transition program, the Peer Group Connection (PGC) program, on the graduation rate at a low-income, Mid-Atlantic high school. The program utilized twelfth grade student peer leaders to create a supportive environment for incoming ninth grade students. Results of a randomized control trial demonstrated that male students who participated in the program during ninth grade were significantly more likely to graduate from high school within four years than male students in the control group (81% versus 63%). Findings suggest that peers can be effective in delivering a school-based, social emotional learning intervention and that it is possible to intervene in the ninth grade to influence the probability of high school graduation.

  16. Problems Concerning Dose Assessments in Epidemiology of High Background Radiation Areas of Yangjiang, China (invited paper)

    International Nuclear Information System (INIS)

    Wei, L.X.; Yuan, Y.L.

    1998-01-01

    The purpose of this study on radiation levels and dose assessments in the epidemiology of a high background radiation area (HBRA) and the control area (CA) is to respond to the needs of epidemiology in these areas, where the inhabitants are continuously exposed to low dose, low dose rate ionising radiation. A brief description is given of how the research group evaluated the feasibility of the investigation by analysing the population size and the radiation levels, how simple reliable methods were used to get the individual annual dose for every cohort member, and how the cohort members were classified into various dose groups for dose-effect relationship analysis. Finally, the use of dose group classification for cancer mortality studies is described. (author)

  17. A hybrid evolutionary algorithm for multi-objective anatomy-based dose optimization in high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Lahanas, M; Baltas, D; Zamboglou, N

    2003-01-01

    Multiple objectives must be considered in anatomy-based dose optimization for high-dose-rate brachytherapy and a large number of parameters must be optimized to satisfy often competing objectives. For objectives expressed solely in terms of dose variances, deterministic gradient-based algorithms can be applied and a weighted sum approach is able to produce a representative set of non-dominated solutions. As the number of objectives increases, or non-convex objectives are used, local minima can be present and deterministic or stochastic algorithms such as simulated annealing either cannot be used or are not efficient. In this case we employ a modified hybrid version of the multi-objective optimization algorithm NSGA-II. This, in combination with the deterministic optimization algorithm, produces a representative sample of the Pareto set. This algorithm can be used with any kind of objectives, including non-convex, and does not require artificial importance factors. A representation of the trade-off surface can be obtained with more than 1000 non-dominated solutions in 2-5 min. An analysis of the solutions provides information on the possibilities available using these objectives. Simple decision making tools allow the selection of a solution that provides a best fit for the clinical goals. We show an example with a prostate implant and compare results obtained by variance and dose-volume histogram (DVH) based objectives

  18. Comparison of high-dose-rate and low-dose-rate brachytherapy in the treatment of endometrial carcinoma

    International Nuclear Information System (INIS)

    Fayed, Alaa; Mutch, David G.; Rader, Janet S.; Gibb, Randall K.; Powell, Matthew A.; Wright, Jason D.; El Naqa, Issam; Zoberi, Imran; Grigsby, Perry W.

    2007-01-01

    Purpose: To compare the outcomes for endometrial carcinoma patients treated with either high-dose-rate (HDR) or low-dose-rate (LDR) brachytherapy. Methods and Materials: This study included 1,179 patients divided into LDR (1,004) and HDR groups (175). Patients with International Federation of Gynecology and Obstetrics (FIGO) surgical Stages I-III were included. All patients were treated with postoperative irradiation. In the LDR group, the postoperative dose applied to the vaginal cuff was 60-70 Gy surface doses to the vaginal mucosa. The HDR brachytherapy prescription was 6 fractions of 2 Gy each to a depth of 0.5 cm from the surface of the vaginal mucosa. Overall survival, disease-free survival, local control, and complications were endpoints. Results: For all stages combined, the overall survival, disease-free survival, and local control at 5 years in the LDR group were 70%, 69%, and 81%, respectively. For all stages combined, the overall survival, disease-free survival, and local control at 5 years in the HDR group were 68%, 62%, and 78%, respectively. There were no significant differences in early or late Grade III and IV complications in the HDR or LDR groups. Conclusion: Survival outcomes, pelvic tumor control, and Grade III and IV complications were not significantly different in the LDR brachytherapy group compared with the HDR group

  19. Evaluation of the fluence to dose conversion coefficients for high energy neutrons using a voxel phantom coupled with the GEANT4 code

    CERN Document Server

    Paganini, S

    2005-01-01

    Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from Galactic cosmic radiation. Crews of future high-speed commercial flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the male adult voxels phantom MAX, developed in the Nuclear Energy Department of Pernambuco Federal University in Brazil, has been coupled with the Monte Carlo simulation code GEANT4. This toolkit, distributed and upgraded from the international scientific community of CERN/Switzerland, simulates thermal to ultrahigh energy neutrons transport and interactions in the matter. The high energy neutrons are pointed as the component that contribute about 70% of the neutron effective dose that represent the 35% to 60% total dose at aircraft altitude. In this research calculations of conversion coefficients from fluence to effective dose are performed for neutrons of energies from 100 MeV ...

  20. Social Cognitive Theory and Physical Activity Among Korean Male High-School Students.

    Science.gov (United States)

    Lee, Chung Gun; Park, Seiyeong; Lee, Seung Hwan; Kim, Hyunwoo; Park, Ji-Won

    2018-02-01

    The most critical step in developing and implementing effective physical activity interventions is to understand the determinants and correlates of physical activity, and it is strongly suggested that such effort should be based on theories. The purpose of this study is to test the direct, indirect, and total effect of social cognitive theory constructs on physical activity among Korean male high-school students. Three-hundred and forty-one 10th-grade male students were recruited from a private single-sex high school located in Seoul, South Korea. Structural equation modeling was used to test the expected relationships among the latent variables. The proposed model accounted for 42% of the variance in physical activity. Self-efficacy had the strongest total effect on physical activity. Self-efficacy for being physically active was positively associated with physical activity ( p social cognitive theory is a useful framework to understand physical activity among Korean male adolescents. Physical activity interventions targeting Korean male high-school students should focus on the major sources of efficacy.

  1. High-dose rate fractionated interstitial radiotherapy for oropharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nose, Takayuki; Inoue, Toshihiko; Inoue, Takehiro; Teshima, Teruki; Murayama, Shigeyuki [Osaka Univ. (Japan). Faculty of Medicine

    1995-03-01

    The limitations of treating oropharyngeal cancer patients with definitive external radiotherapy are the complications of salivary glands, taste buds, mandible and temporomandibular joints. To avoid these complications we started interstitial radiotherapy as boost after 46 Gy of external radiotherapy. Ten cases (retromolar trigone; 1, soft palate; 1, base of tongue; 3, lateral wall; 5) were treated with this method and seven cases were controlled locally. With short follow-up period, xerostomia and dysgeusia are less than definitive external radiotherapy as clinical impression and no in-field recurrences have been experienced. With markedly increased tumor dose, the local control rate can be improved. This treatment method will be an alternative to definitive external radiotherapy to gain better QOL and higher control rate. (author).

  2. The high dose and low dose food irradiation programmes in the United States of America

    International Nuclear Information System (INIS)

    Brynjolfsson, A.

    1978-01-01

    Many highly acceptable shelf-stable irradiated food items have been developed in the United States of America. The most extensive wholesomeness studies ever carried out on any food-processing method continue to indicate that irradiated foods are wholesome. (author)

  3. High-dose myeloablative versus conventional low-dose radioimmunotherapy (RIT) of mantle cell lymphoma (MCL) with the chimeric anti-CD20 antibody C2B8

    International Nuclear Information System (INIS)

    Behr, T.M.; Gotthardt, M.; Schipperm, M.L.; Gratz, S.; Behe, M.P.; Brittinger, G.; Woermann, B.; Becker, W.

    2002-01-01

    CD20 has been used as target molecule for low-dose as well as high-dose, myeloablative RIT of B-cell NHL. MCL is an especially aggressive, prognostically unfavorable form of B-cell NHL. The aim of this study was to investigate whether high-dose, myeloablative RIT with the 131 I-labeled chimeric anti-CD20 antibody C2B8 (rituxan, Mabthera, Roche) may be therapeutically more effective than conventional low-dose therapy in MCL. A total of twelve patients with chemorefractory or relapsed mantle cell lymphoma were studied so far (all of them having relapsed after high-dose chemotherapy, seven of them combined with 12 Gy TBI). A diagnostic-dosimetric study was performed with 10 mCi of 131 I-C2B8 at a protein dose of 2.5 mg/kg. In case of splenic pooling, the protein dose was increased until a more 'favorable' biodistribution was obtained. Therapy was performed with conventional (30-75 mCi; n=4) or myeloablative activities (261-515 mCi; n=8) of 131 I-C2B8 at the previously optimized protein dose, aiming at whole-body doses of ≤ 0.8 Gy (for low-dose RIT) or lung doses of ≤ 27 Gy (for high-dose RIT). Clinical follow-up was obtained for up to 42 months. Overall, in 11 patients the 2.5 mg/kg protein dose was used, whereas in one patient with marked splenomegaly, 10 mg/kg were necessary to overcome the splenic antigenic sink. In the high-dose patients, non-hematologic toxicity was restricted to mild to moderate nausea, fever, transient bilirubin or liver enzyme elevations. Despite thyroid blocking, 6/8 high-dose (in contrast to 0/4 low-dose) patients developed hypothyroidism, requiring thyroxine substitution at 6-18 months after RIT. The response rate in the low-dose arm was only 1(PR)/4, whereas 7/8 high-dose patients experienced complete and the remainder a partial remission. 6 high-dose patients are still in CR (one of them relapsed locally at 3 months, one systemically at 26 months after RIT), and 7 are still alive for up to 42+ months. In contrast to low-dose therapy

  4. Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer; Avaliacao da dose no reto em pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do cancer do colo uterino

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jetro Pereira de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina; Rosa, Luiz Antonio Ribeiro da [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], e-mail: lrosa@ird.gov.br; Batista, Delano Valdivino Santos; Bardella, Lucia Helena [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil). Unit of Medical Physics; Carvalho, Arnaldo Rangel [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. of Thermoluminescent Dosimetry

    2009-03-15

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

  5. High gamma dose response of the electrical properties of polyethylene terephthalate thin films

    International Nuclear Information System (INIS)

    Radwan, R.M.

    2007-01-01

    Electrical properties of polyethylene terephthalate (PET), irradiated with gamma rays, have been investigated. The PET films were irradiated with high gamma dose levels in the range from 100 to 2000 kGy. The changes in the DC (σ DC ) and the ac (σ ac ) conductivities, with the dose, have been performed. The effect of gamma irradiation on the dielectric constant (ε') and loss (ε'') has been determined. Also, the dose dependence of the frequency exponent index (S), the resonance frequency (Fc) and the hopping frequency (ω P ) have been obtained. The obtained results show that increasing gamma dose leads to slight increase in σ DC , σ ac and ε', while no change was observed in ε'' value. Meanwhile, S, Fc and ω P are inversely proportional to the dose. Accordingly, the study suggests the possibility of using PET films in electronic components (capacitors, resistors, etc.), especially that operate at high gamma dose environments for the frequency independent applications

  6. Effects of prenatal exposure to a low dose atrazine metabolite mixture on pubertal timing and prostate development of male Long-Evans rats

    Energy Technology Data Exchange (ETDEWEB)

    Stanko, Jason [National Institute of Environmental Health Sciences (NIEHS); Enoch, Rolondo [North Carolina Central University, Durham; Rayner, Jennifer L [ORNL; Davis, Christine [U.S. Environmental Protection Agency; Wolf, Douglas [U.S. Environmental Protection Agency; Malarkey, David [University of North Carolina, Chapel Hill; Fenton, Suzanne [National Institute of Environmental Health Sciences (NIEHS)

    2010-12-01

    The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and deisopropylatrazine. Pregnant Long-Evans rats were treated by gavage with 0.09, 0.87, or 8.73 mg AMM/kg body weight (BW), vehicle, or 100 mg ATR/kg BW positive control, on gestation days 15 19. Preputial separation was significantly delayed in 0.87 mg and 8.73 mg AMM-exposed males. AMM-exposed males demonstrated a significant treatment-related increase in incidence and severity of inflammation in the prostate on postnatal day (PND) 120. A dose-dependent increase in epididymal fat masses and prostate foci were grossly visible in AMM-exposed offspring. These results indicate that a short, late prenatal exposure to mixture of chlorotriazine metabolites can cause chronic prostatitis in male LE rats. The mode of action for these effects is presently unclear.

  7. Plasma Doping - Enabling Technology for High Dose Logic and Memory Applications

    International Nuclear Information System (INIS)

    Miller, T.; Godet, L.; Papasouliotis, G. D.; Singh, V.

    2008-01-01

    As logic and memory device dimensions shrink with each generation, there are more high dose implants at lower energies. Examples include dual poly gate (also referred to as counter-doped poly), elevated source drain and contact plug implants. Plasma Doping technology throughput and dopant profile benefits at these ultra high dose and lower energy conditions have been well established [1,2,3]. For the first time a production-worthy plasma doping implanter, the VIISta PLAD tool, has been developed with unique architecture suited for precise and repeatable dopant placement. Critical elements of the architecture include pulsed DC wafer bias, closed-loop dosimetry and a uniform low energy, high density plasma source. In this paper key performance metrics such as dose uniformity, dose repeatability and dopant profile control will be presented that demonstrate the production-worthiness of the VIISta PLAD tool for several high dose applications.

  8. Effect of source and dose of probiotics and exogenous fibrolytic enzymes (EFE) on intake, feed efficiency, and growth of male buffalo (Bubalus bubalis) calves.

    Science.gov (United States)

    Malik, Raman; Bandla, Srinivas

    2010-08-01

    Probiotics of Lactobacillus acidophilus, Saccharomyces cerevisiae, and Aspergillus niger and three commercial exogenous fibrolytic enzymes (EFE) were tested in vitro to select best source and optimum dose followed by in vivo studies on male buffalo calves. Bacterial (P calves with concentrate supplement (CS). Calves were randomly divided into three groups either without probiotics and EFE (CG) or with probiotics (EG(1)) or probiotics combined with EFE (EG(2)) on wheat straw diet. Organic matter, neutral detergent fiber, and acid detergent fiber digestibility was improved significantly. Average daily weight gain (ADG) and feed efficiency were significantly higher (P feed efficiency was 2.6% or 1.6% more (P calves.

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  10. Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

    International Nuclear Information System (INIS)

    Cantinha, Rebeca S.; Nakano, Eliana; Silva, Luanna R.S.

    2009-01-01

    Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of 60 Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD 50 obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

  11. Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

    Energy Technology Data Exchange (ETDEWEB)

    Cantinha, Rebeca S.; Nakano, Eliana [Instituto Butantan, Sao Paulo, SP (Brazil). Lab. de Parasitologia], e-mail: rebecanuclear@gmail.com, e-mail: eliananakano@butantan.gov.br; Borrely, Sueli I. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes], e-mail: sborrely@ipen.br; Amaral, Ademir; Melo, Ana M.M.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR)], e-mail: amaral@ufpe.br; Silva, Luanna R.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia. Lab. de Radiobiologia], e-mail: amdemelo@hotmail.com, e-mail: luannaribeiro_lua@hotmail.com

    2009-07-01

    Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of {sup 60}Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD{sub 50} obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

  12. Methylation changes in muscle and liver tissues of male and female mice exposed to acute and chronic low-dose X-ray-irradiation

    International Nuclear Information System (INIS)

    Kovalchuk, Olga; Burke, Paula; Besplug, Jill; Slovack, Mark; Filkowski, Jody; Pogribny, Igor

    2004-01-01

    The biological and genetic effects of chronic low-dose radiation (LDR) exposure and its relationship to carcinogenesis have received a lot of attention in the recent years. For example, radiation-induced genome instability, which is thought to be a precursor of tumorogenesis, was shown to have a transgenerational nature. This indicates a possible involvement of epigenetic mechanisms in LDR-induced genome instability. Genomic DNA methylation is one of the most important epigenetic mechanisms. Existing data on radiation effects on DNA methylation patterns is limited, and no one has specifically studied the effects of the LDR. We report the first study of the effects of whole-body LDR exposure on global genome methylation in muscle and liver tissues of male and female mice. In parallel, we evaluated changes in promoter methylation and expression of the tumor suppressor gene p16 INKa and DNA repair gene O 6 -methylguanine-DNA methyltransferase (MGMT). We observed different patterns of radiation-induced global genome DNA methylation in the liver and muscle of exposed males and females. We also found sex and tissue-specific differences in p16 INKa promoter methylation upon LDR exposure. In male liver tissue, p16 INKa promoter methylation was more pronounced than in female tissue. In contrast, no significant radiation-induced changes in p16 INKa promoter methylation were noted in the muscle tissue of exposed males and females. Radiation also did not significantly affect methylation status of MGMT promoter. We also observed substantial sex differences in acute and chronic radiation-induced expression of p16 INKa and MGMT genes. Another important outcome of our study was the fact that chronic low-dose radiation exposure proved to be a more potent inducer of epigenetic effects than the acute exposure. This supports previous findings that chronic exposure leads to greater genome destabilization than acute exposure

  13. High-dose-rate brachytherapy in the treatment of uterine cervix cancer. Analysis of dose effectiveness and late complications

    International Nuclear Information System (INIS)

    Ferrigno, Robson; Novaes, Paulo Eduardo Ribeiro dos Santos; Pellizzon, Antonio Cassio Assis; Maia, Maria Aparecida Conte; Fogarolli, Ricardo Cesar; Gentil, Andre Cavalcanti; Salvajoli, Joao Victor

    2001-01-01

    Purpose: This retrospective analysis aims to report results of patients with cervix cancer treated by external beam radiotherapy (EBR) and high-dose-rate (HDR) brachytherapy. Methods and Materials: From September 1992 to December 1996, 138 patients with FIGO Stages II and III and mean age of 56 years were treated. Median EBR to the whole pelvis was 45 Gy in 25 fractions. Parametrial boost was performed in 93% of patients, with a median dose of 14.4 Gy. Brachytherapy with HDR was performed during EBR or following its completion with a dose of 24 Gy in four weekly fractions of 6 Gy to point A. Median overall treatment time was of 60 days. Patient age, tumor stage, and overall treatment time were variables analyzed for survival and local control. Cumulative biologic effective dose (BED) at rectal and bladder reference points were correlated with late complications in these organs and dose of EBR at parametrium was correlated with small bowel complications. Results: Median follow-up time was 38 months. Overall survival, disease-free survival, and local control at 5 years was 53.7%, 52.7%, and 62%, respectively. By multivariate and univariate analysis, overall treatment time up to 50 days was the only statistically significant adverse variable for overall survival (p=0.003) and actuarial local control (p=0.008). The 5-year actuarial incidence of rectal, bladder, and small bowel late complications was 16%, 11%, and 14%, respectively. Patients treated with cumulative BED at rectum points above 110 Gy 3 and at bladder point above 125 Gy 3 had a higher but not statistically significant 5-year actuarial rate of complications at these organs (18% vs. 12%, p=0.49 and 17% vs. 9%, p=0.20, respectively). Patients who received parametrial doses larger than 59 Gy had a higher 5-year actuarial rate of complications in the small bowel; however, this was not statistically significant (19% vs. 10%, p=0.260). Conclusion: This series suggests that 45 Gy to the whole pelvis combined with

  14. Controversies in external beam and high dose rate brachytherapy of oesophageal cancer

    International Nuclear Information System (INIS)

    Sur, R.K.; Levin, V.C.; Malas, Simon; Donde, Bernard

    1994-01-01

    Various controversies in the treatment of oesophageal carcinoma with external beam radiotherapy and high dose rate intracavitary irradiation have been reviewed. Conflicting results from different parts of the world has made it difficult to optimize the radiation dose that may give the best results. More studies and longer follow-up are needed before a definite conclusion can be made on the optimization of dose. (author). 18 refs., 2 tabs

  15. Alanine-EPR dosimetry system for high industrial as well radiotherapeutic dose measurement

    International Nuclear Information System (INIS)

    Dobrovodsky, J.; Bukovjan, J.

    2005-01-01

    Slovak Institute of Metrology is developing new metrology standard for high doses, based on the alanine-EPR as a reference dosimetry system. A Bruker e-scan EPR analyser developed specifically for alanine dosimetry has improved stability of EPR measurement, especially at lower dose range. The standard e-scan system provides sensitivity below 1 Gray. After further improvement of the system and lowering of dose determination expanded uncertainty down below 1 %, its utilisation for radiotherapy field is expected (authors)

  16. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Froehlich, Georgina; Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor

    2010-01-01

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D min ) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D r ) and urethra (D u ), dose to volume of 2 cm 3 of the rectum (D 2ccm ), and 0.1 cm 3 and 1% of the urethra (D 0.1ccm and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V p ) was 27.1 cm 3 . The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D min was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D 2ccm = 49% for the rectum, D 0.1ccm = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D r , D 2ccm ) = 0.69, R(D u , D 0.1ccm ) = 0.64, R(D u , D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric

  17. Dosimetric Evaluation of High-Dose-Rate Interstitial Brachytherapy Boost Treatments for Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Georgina [Semmelweis Univ., Budapest (Hungary); Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary); Agoston, Peter; Loevey, Jozsef; Somogyi, Andras; Fodor, Janos; Polgar, Csaba; Major, Tibor [Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary)

    2010-07-15

    Purpose: to quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Material and methods: treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D{sub min}) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D{sub r}) and urethra (D{sub u}), dose to volume of 2 cm{sup 3} of the rectum (D{sub 2ccm}), and 0.1 cm{sup 3} and 1% of the urethra (D{sub 0.1ccm} and D1) were determined. Nonparametric correlation analysis was performed between these parameters. Results: the median number of needles was 16, the mean prostate volume (V{sub p}) was 27.1 cm{sup 3}. The mean V90, V100, V150, and V200 were 90%, 97%, 39% and 13%, respectively. The mean D90 was 109%, and the D{sub min} was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D{sub 2ccm} = 49% for the rectum, D{sub 0.1ccm} = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D{sub r}, D{sub 2ccm}) = 0.69, R(D{sub u}, D{sub 0.1ccm}) = 0.64, R(D{sub u}, D1) = 0.23. Conclusion: US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose

  18. Dosimetric evaluation of high-dose-rate interstitial brachytherapy boost treatments for localized prostate cancer.

    Science.gov (United States)

    Fröhlich, Georgina; Agoston, Péter; Lövey, József; Somogyi, András; Fodor, János; Polgár, Csaba; Major, Tibor

    2010-07-01

    To quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D(min)) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D(r)) and urethra (D(u)), dose to volume of 2 cm(3) of the rectum (D(2ccm)), and 0.1 cm(3) and 1% of the urethra (D(0.1ccm) and D1) were determined. Nonparametric correlation analysis was performed between these parameters. The median number of needles was 16, the mean prostate volume (V(p)) was 27.1 cm(3). The mean V90, V100, V150, and V200 were 99%, 97%, 39%, and 13%, respectively. The mean D90 was 109%, and the D(min) was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D(2ccm) = 49% for the rectum, D(0.1ccm) = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D(r),D(2ccm)) = 0.69, R(D(u),D0.(1ccm)) = 0.64, R(D(u),D1) = 0.23. US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric parameter is recommended.

  19. Breast Cancer Knowledge Among Male High School Students in Saudi Arabia.

    Science.gov (United States)

    Al-Amoudi, Samia; AlHomied, Moaiad Tariq Abdul-Aziz; AlSayegh, Nasser Youssef Nasser; Radi, Osama Naseem Ismail; Zagzoog, Mohammed Majed Suliman; Aloufi, Omar Faisal Mubarak; Al-Harbi, Abdullah Abdulkarim Ali; Tayeb, Safwan; Hassanien, Mohammed; Al-Ahwal, Mahmoud; Eldeek, Basem; Harakeh, Steve

    2016-12-01

    Breast cancer (BC) accounts for 24 % of all women cancer cases diagnosed in Saudi Arabia each year. Awareness is extremely important in combating this disease. This study was undertaken to assess male high school students' response to BC. This cross-sectional survey was performed on male high school students across schools in Jeddah. A questionnaire gathered data on respondent demographics, beliefs about BC, BC risk factors, early screening methods, and role of men in BC. Statistical analysis was done using SPSS 20. A total of 824 students participated, with an average age of 17.0 years. There was more than 50 % agreement that early detection of BC enhances the chances of recovery, that BC is treatable, and that clinical breast examination and breastfeeding provide protection from BC. Around half the survey population thought that BC was fatal and contagious. Fewer than 50 % thought that BC was inherited and related to smoking, consumption of contraceptive pills, repeated exposure to radiation, obesity, and wearing a bra and that breast tumors were all malignant and spread to different parts of the body. Others knew that mammograms should be performed periodically. A high percentage persuaded their relatives to have mammograms and provided them with psychological support. Knowledge of BC among male high school students in Saudi Arabia is still limited, and, therefore, programs and activities need to be established to increase awareness among high school students.

  20. Brachytherapy guideline in prostate cancer (high and low dose rate)

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, Samir Abdallah; Pimentel, Leonardo [Sociedade Brasileira de Radioterapia (SBR), Rio de Janeiro, RJ (Brazil)

    2017-04-15

    Through the elaboration of seven relevant clinical questions related to the proposed theme, we sought to present the main evidences regarding safety, toxicity and effectiveness of the presented radiotherapy (RT) techniques. The study population consisted of male patients of all ages with early primary prostate cancer and candidates for treatment with curative intent. For this, a systematic review of the literature was carried out in primary scientific databases (MEDLINE - PubMed; Embase - Elsevier; LILACS - BIREME; Cochrane Library -Record of Controlled Trials). All articles available through February 22, 2015 were considered. The search strategy used in MEDLINE searches is described in Appendix 1. The articles were selected based on critical evaluation, seeking the best evidence available. The recommendations were elaborated from discussions held with a drafting group composed of four members of the Brazilian Society of Radiotherapy. The guideline was reviewed by an independent group, which specializes in evidence-based clinical guidelines. After completion, the guideline was released for public consultation for 15 days; the suggestions obtained were forwarded to the authors for evaluation and possible insertion in the final text. (author)

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  2. Preservation of Minced Meats by Using Medium and High-doses Irradiation

    International Nuclear Information System (INIS)

    Hammad, A.A.I.; Swailam, H.M.H.; Taha, S.M.A.

    2003-01-01

    The effect of medium (2.5-10 kGy) dose irradiation and high(20-70 kGy) dose irradiation on the microbiological, chemical and organoleptic properties of minced meat samples was studied. It was found that irradiation dose of only 5 kGy greatly reduced all microbial counts and completely eliminated all non-spore forming pathogenic bacteria contaminated minced meat samples. Consequently this irradiation dose extended the refrigerated (3 degree ±1) storage life of these products for more than 8 weeks. This irradiation dose almost did not affect the chemical composition, particularly the main amino acids and main fatty acids of minced meat samples. Panelists could not differentiate between irradiated minced meat samples at this dose and unirradiated samples. High doses irradiation, i.e.40 and 70 kGy were sufficient and efficient in sterilization of minced meat samples and in obtaining long-stable minced meat products (Two years) at ambient temperature. These irradiation doses slightly reduced (not more than 7%) aspartic acid, glutamic acid, methionine and lysine of minced meat. It also decreased the relative percentage of total unsaturated fatty acids by not more than 17 % . These high irradiation doses caused loss of C 18:3 and C 20:1

  3. The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate

    International Nuclear Information System (INIS)

    Sminia, Peter; Schneider, Christoph J.; Fowler, Jack F.

    2002-01-01

    Background and Purpose: Indications of the existence of long repair half-times on the order of 2-4 h for late-responding human normal tissues have been obtained from continuous hyperfractionated accelerated radiotherapy (CHART). Recently, these data were used to explain, on the basis of the biologically effective dose (BED), the potential superiority of fractionated high-dose rate (HDR) with large fraction sizes of 5-7 Gy over continuous low-dose rate (LDR) irradiation at 0.5 Gy/h in cervical carcinoma. We investigated the optimal fraction size in HDR brachytherapy and its dependency on treatment choices (overall treatment time, number of HDR fractions, and time interval between fractions) and treatment conditions (reference low-dose rate, tissue repair characteristics). Methods and Materials: Radiobiologic model calculations were performed using the linear-quadratic model for incomplete mono-exponential repair. An irradiation dose of 20 Gy was assumed to be applied either with HDR in 2-12 fractions or continuously with LDR for a range of dose rates. HDR and LDR treatment regimens were compared on the basis of the BED and BED ratio of normal tissue and tumor, assuming repair half-times between 1 h and 4 h. Results: With the assumption that the repair half-time of normal tissue was three times longer than that of the tumor, hypofractionation in HDR relative to LDR could result in relative normal tissue sparing if the optimum fraction size is selected. By dose reduction while keeping the tumor BED constant, absolute normal tissue sparing might therefore be achieved. This optimum HDR fraction size was found to be largely dependent on the LDR dose rate. On the basis of the BED NT/TUM ratio of HDR over LDR, 3 x 6.7 Gy would be the optimal HDR fractionation scheme for replacement of an LDR scheme of 20 Gy in 10-30 h (dose rate 2-0.67 Gy/h), while at a lower dose rate of 0.5 Gy/h, four fractions of 5 Gy would be preferential, still assuming large differences between tumor

  4. Effects of low priming dose irradiation on cell cycle arrest of HepG2 cells caused by high dose irradiation

    International Nuclear Information System (INIS)

    Xia Jingguang; Jin Xiaodong; Chinese Academy of Sciences, Beijing; Li Wenjian; Wang Jufang; Guo Chuanling; Gao Qingxiang

    2005-01-01

    Human hepatoma cells hepG2 were irradiated twice by 60 Co γ-rays with a priming dose of 5 cGy and a higher dose of 3 Gy performed 4h or 8h after the low dose irradiation. Effects of the priming dose irradiation on cell cycle arrest caused by high dose were examined with flow cytometry. Cells in G 2 /M phase accumulated temporarily after the 5 cGy irradiation, and proliferation of tumor cells was promoted significantly by the low dose irradiation. After the 3 Gy irradiation, G 2 phase arrest occurred, and S phase delayed temporally. In comparison with 3 kGy irradiation only, the priming dose delivered 4h prior to the high dose irradiation facilitated accumulation of hepG2 cells in G 2 /M phase, whereas the priming dose delivered 8h prior to the high dose irradiation helped the cells to overcome G 2 arrest. It was concluded that effects of the priming dose treatment on cell cycle arrest caused by high dose irradiation were dependent on time interval between the two irradiations. (authors)

  5. Gafchromic EBT-XD film: Dosimetry characterization in high-dose, volumetric-modulated arc therapy.

    Science.gov (United States)

    Miura, Hideharu; Ozawa, Shuichi; Hosono, Fumika; Sumida, Naoki; Okazue, Toshiya; Yamada, Kiyoshi; Nagata, Yasushi

    2016-11-08

    Radiochromic films are important tools for assessing complex dose distributions. Gafchromic EBT-XD films have been designed for optimal performance in the 40-4,000 cGy dose range. We investigated the dosimetric characteristics of these films, including their dose-response, postexposure density growth, and dependence on scanner orientation, beam energy, and dose rate with applications to high-dose volumetric-modulated arc therapy (VMAT) verification. A 10 MV beam from a TrueBeam STx linear accelerator was used to irradiate the films with doses in the 0-4,000 cGy range. Postexposure coloration was analyzed at postirradiation times ranging from several minutes to 48 h. The films were also irradiated with 6 MV (dose rate (DR): 600 MU/min), 6 MV flattening filter-free (FFF) (DR: 1,400 MU/ min), and 10 MV FFF (DR: 2,400 MU/min) beams to determine the energy and dose-rate dependence. For clinical examinations, we compared the dose distribu-tion measured with EBT-XD films and calculated by the planning system for four VMAT cases. The red channel of the EBT-XD film exhibited a wider dynamic range than the green and blue channels. Scanner orientation yielded a variation of ~ 3% in the net optical density (OD). The difference between the film front and back scan orientations was negligible, with variation of ~ 1.3% in the net OD. The net OD increased sharply within the first 6 hrs after irradiation and gradually afterwards. No significant difference was observed for the beam energy and dose rate, with a variation of ~ 1.5% in the net OD. The gamma passing rates (at 3%, 3 mm) between the film- measured and treatment planning system (TPS)-calculated dose distributions under a high dose VMAT plan in the absolute dose mode were more than 98.9%. © 2016 The Authors.

  6. Adjuvant high-dose-rate brachytherapy after external beam radiotherapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Oezyar, Enis; Yildz, Ferah; Akyol, Fadil H.; Atahan, I. Lale

    2002-01-01

    Purpose: To compare the local control and survival rates obtained with either external beam radiation therapy (ERT) and adjuvant high-dose-rate (HDR) brachytherapy (BRT) or ERT alone in patients with nasopharyngeal cancer. Methods and Materials: Between December 1993 and December 1999, 144 patients (106 male, 38 female) with the diagnosis of nasopharyngeal cancer were treated with either ERT and adjuvant HDR BRT (Group A) or ERT alone (Group B) at our department. BRT was not applied in 38 patients for the following reasons: (1) Unit was unavailable (n=13), (2) Patient was younger than 18 years (n=17), (3) Patient received accelerated hyperfractionated ERT (n=6), and (4) Patient refused BRT (n=2). The median age for whole group was 43 (range: 9-82 years). According to the AJCC-1997 staging system, there were 11 (7.6%), 35 (24.3%), 38 (26.4%), and 60 (41.7%) patients in Stage I, II, III, and IV, respectively. There were 57 (39.6%) patients with T1, 41 (28.5%) with T2, 20 (13.9%) with T3, and 26 (18.1%) with T4 tumors. Histopathologic diagnosis was WHO 2-3 in 137 (95.2%) patients. ERT doses ranged between 58.8 and 74 Gy (median: 66 Gy). There were significantly more patients with young age, N2 status, and Stage III disease in Group B and with Stage II disease in Group A. Significantly more patients received chemotherapy in Group B. BRT with an HDR 192 Ir microSelectron afterloading unit was delivered in 106 patients at the conclusion of ERT using a single-channel nasal applicator. Dose was prescribed at 1 cm from the source, and total dose of 12 Gy in 3 fractions on 3 consecutive days was given immediately after ERT. Besides radiotherapy, 82 (56.9%) patients received cisplatin-based chemotherapy, as well. Follow-up time ranged between 12 and 80 months (median: 32 months). Results: The two groups were comparable in terms of local recurrence, locoregional failure, regional failure, and rate of distant metastasis. Local failure was observed in 11 (10.3%) out of 106

  7. High Throughput Determinations of Critical Dosing Parameters (IVIVE workshop)

    Science.gov (United States)

    High throughput toxicokinetics (HTTK) is an approach that allows for rapid estimations of TK for hundreds of environmental chemicals. HTTK-based reverse dosimetry (i.e, reverse toxicokinetics or RTK) is used in order to convert high throughput in vitro toxicity screening (HTS) da...

  8. Inhibitory Effect of High Dose of the Flavonoid Quercetin on Amygdala Electrical Kindling in Rats

    Directory of Open Access Journals (Sweden)

    Tourandokht Baluchnejadmojarad

    2010-05-01

    Full Text Available A B S T R A C T Introduction: Epilepsy is a chronic neurological disorder in which patients experience spontaneous recurrent seizures. Although the most commonly recommended therapy is drug treatment, some patients do not achieve adequate control of their seizures on existing drugs. New medications with novel mechanisms of action are needed to help those patients whose seizures are resistant to currently-available drugs. Therefore, the anti-convulsant effect of a high dose of quercetin was evaluated in amygdala kindling model in male rats. Methods: Rats were divided into sham-operated group, quercetintreated SH, kindled, and quercetin-treated kindled rats. Quercetin was administered i.p. one day before amygdale kindling for 3 weeks (40 mg/kg/day. The parameters seizure stage, AD duration, the latency to the onset of stage 4, and the duration of stage 5 were analyzed. Results: The results showed that quercetin pretreatment causes a lower seizure intensity in treated kindled rats (p<0.05-0.01, a lower after-discharge duration (p<0.05-0.01, and a higher latency to stage IV (p<0.05 as compared to untreated kindled ones. Discussion: To conclude, chronic administration of quercetin inhibits amygdala electrical kindling and more studies are warranted to clarify its underlying mechanisms.

  9. Efficacy and tolerability of high-dose phenobarbital in children with focal seizures.

    Science.gov (United States)

    Okumura, Akihisa; Nakahara, Eri; Ikeno, Mitsuru; Abe, Shinpei; Igarashi, Ayuko; Nakazawa, Mika; Takasu, Michihiko; Shimizu, Toshiaki

    2016-04-01

    We retrospectively reviewed the outcomes of children with focal epilepsy treated with oral high-dose phenobarbital. We reviewed data on children (agedphenobarbital (>5 mg/kg/day to maintain a target serum level >40 μg/mL) for at least 6 months. Seizure frequency was evaluated after phenobarbital titration, and 1 and 2 years after high-dose phenobarbital treatment commenced. Treatment was judged effective when seizure frequencies fell by ⩾75%. Seven boys and eight girls were treated. The median age at commencement of high-dose phenobarbital therapy was 30 months. The maximal serum phenobarbital level ranged from 36.5 to 62.9 μg/mL. High-dose PB was effective in seven. In two patients, treatment was transiently effective, but seizure frequency later returned to the baseline. High-dose PB was ineffective in six. No significant association between effectiveness and any clinical variable was evident. Drowsiness was recorded in nine patients, but no patient developed a behavioral problem or hypersensitivity. Oral high-dose phenobarbital was effective in 7 of 15 patients with focal epilepsy and well tolerated. High-dose PB may be useful when surgical treatment is difficult. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  10. Routine chest and abdominal high-pitch CT: An alternative low dose protocol with preserved image quality

    International Nuclear Information System (INIS)

    Amacker, Nadja A.; Mader, Caecilia; Alkadhi, Hatem; Leschka, Sebastian; Frauenfelder, Thomas

    2012-01-01

    Objective: To investigate the radiation dose and image quality of the high-pitch dual source computer tomography (DSCT) for routine chest and abdominal scans. Methods: 130 consecutive patients (62 female, 68 male, median age 55 years) were included. All patients underwent 128-slice high-pitch DSCT (chest n = 99; abdomen n = 84) at a pitch of 3.2. Two observers independently rated image quality using a 4-point score (1: excellent to 4: non-diagnostic). Image noise was measured and operational radiation dose quantities were recorded. An additional group of 132 patients (chest, n = 80; abdomen n = 52) scanned with standard-pitch CT matched for age, gender, and body mass index (BMI) served as control group. Results: Interobserver agreement for image quality rating was good (k = 0.74). Subjective image quality of high-pitch CT was diagnostic in all patients (median score chest; 2, median score abdomen: 2). Image noise of high-pitch CT was comparable to standard-pitch for the chest (p = 0.32) but increased in the abdomen (p < 0.0001). For high-pitch CT radiation dose was 4.4 ± 0.9 mSv (chest) and 6.5 ± 1.2 mSv (abdomen). These values were significantly lower compared to standard-pitch CT (chest: 5.5 ± 1.2 mSv; abdomen: 11.3 ± 3.8 mSv). Conclusion: Based on the technical background high-pitch dual source CT may serve as an alternative scan mode for low radiation dose routine chest and abdominal CT.

  11. 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.

  12. Applichation of the sulphate ceric dosimetric in the high doses range

    International Nuclear Information System (INIS)

    Prieto Miranda, F.

    1991-01-01

    The ceric-cerous dosimetric system is one of the system more employed in the high dose dosimetry. The spectrophotometric procedure to measure the ceric-concentration is an usual analityc method to determine the absorbed dose. On the other hand, due at increase employ of the irradiation process control. In this paper is realized the ceric-cerous dosimetric calibration in the dose range of 0,6 - 5 kGy and the application in the irradiation process control to differents absorbed dose values

  13. Dose for background radioactivity in areas with high radioactivity levels in the Pinar del Rio province

    International Nuclear Information System (INIS)

    Alcaide Orpi, J.; Oliveira Acosta, J.; Valdes Hernadez, G.M.; Leal Ramirez, M.R.; Blanco Jorrin, N.

    1998-01-01

    The objective the work is to know the areas with high natural radiation doses, for they were used it the data obtained by the studies it has more than enough favorability for radioactive minerals carried out in different regions to the Pinar del Rio province in the 1986 to 1993 years and the doses calculations they were carried out according to the effective methodology

  14. High-dose chemotherapy : studies on supportive care, quality of life and late effects of treatment

    NARCIS (Netherlands)

    Nieboer, Peter

    2008-01-01

    Drug resistance is a major problem in the treatment of malignancies. Based on steep dose-response relationship for certain chemotherapeutic drugs in vitro on tumor cell survival, high-dose chemotherapy was considered of interest for the treatment of malignancies. Introduction of autologous

  15. Extra-high doses detected in the enamel of human teeth in the Techa riverside region

    Energy Technology Data Exchange (ETDEWEB)

    Shishkina, E.A., E-mail: ElenaA.Shishkina@gmail.com [Urals Research Center for Radiation Medicine, 68A, Vorovsky Str., 454076 Chelyabinsk (Russian Federation); Degteva, M.O.; Tolstykh, E.I.; Volchkova, A. [Urals Research Center for Radiation Medicine, 68A, Vorovsky Str., 454076 Chelyabinsk (Russian Federation); Ivanov, D.V. [Institute of Metal Physics, Russian Academy of Sciences, 18 S. Kovalevsky Str, 620041 Yekaterinburg (Russian Federation); Wieser, A. [Helmholtz Zentrum Muenchen, German Research Centre for Environmental Health, D-85764 Neuherberg (Germany); Della Monaca, S. [Istituto Superiore di Sanita, 00161 Rome (Italy); Istituto Regina Elena, 00144 Rome (Italy); Fattibene, P. [Istituto Superiore di Sanita, 00161 Rome (Italy); Istituto Nazionale di Fisica Nucleare, 00161 Rome (Italy)

    2011-09-15

    During the long-term study of tooth enamel by EPR dosimetry for population exposed to radiation due to contamination of the Techa River, it was found out that for some of the tooth donors the dose accumulated in tooth enamel could be as high as several tens of Gy. Such doses were absorbed only in tooth enamel and they should not be associated with exposures to other organs or the whole body. The nature of such doses was discussed in a number of previous papers where it was shown that the source of such doses is {sup 90}Sr incorporated in the calcified dental tissues. However, among specialists in radiation dosimetry who were not involved in the biokinetic studies, the nature and dosimetric significance of extra-high doses in tooth enamel are still raising questions. The aim of the current paper is to summarize the accumulated information on extra-high doses in the teeth of the Techa riverside residents, describe the dose levels observed, explain the nature of extra-high doses in the enamel and discuss their informative value. The paper includes an overview of already published findings and an analysis of information collected in the data bank of the Urals Research Center for Radiation Medicine (URCRM), Chelyabinsk, Russia, which has not been published before.

  16. Maternal high-dose folic acid during pregnancy and asthma medication in the offspring

    NARCIS (Netherlands)

    Zetstra-van der Woude, Priscilla A.; De Walle, Hermien E. K.; Hoek, Annemieke; Bos, H. Jens; Boezen, H. Marike; Koppelman, Gerhard H.; de Jong-van den Berg, Lolkje T. W.; Scholtens, Salome

    2014-01-01

    Purpose Low-dose folic acid supplementation (0.5 mg) taken during pregnancy has been associated with an increased risk for childhood asthma. The effect of high-dose folic acid (5 mg) advised to women at risk for having a child with neural tube defect has not been assessed so far. Our aim was to

  17. o-Toluidine blood protein adducts: HPLC analysis with fluorescence detection after a single dose in the adult male rat

    International Nuclear Information System (INIS)

    Cheever, K.L.; DeBord, G.D.; Swearengin, T.F.

    1991-01-01

    Hemoglobin (Hb) and albumin (Alb) adducts of the suspect human carcinogen o-toluidine (OT) were quantified in blood samples collected f