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Sample records for lethal dose ld50

  1. Acute Oral Toxicity of Tetrodotoxin in Mice: Determination of Lethal Dose 50 (LD50 and No Observed Adverse Effect Level (NOAEL

    Directory of Open Access Journals (Sweden)

    Paula Abal

    2017-02-01

    Full Text Available Tetrodotoxin (TTX is starting to appear in molluscs from the European waters and is a hazard to seafood consumers. This toxin blocks sodium channels resulting in neuromuscular paralysis and even death. As a part of the risk assessment process leading to a safe seafood level for TTX, oral toxicity data are required. In this study, a 4-level Up and Down Procedure was designed in order to determine for the first time the oral lethal dose 50 (LD50 and the No Observed Adverse Effect Level (NOAEL in mice by using an accurate well-characterized TTX standard.

  2. Alternative methods for the median lethal dose (LD(50)) test: the up-and-down procedure for acute oral toxicity.

    Science.gov (United States)

    Rispin, Amy; Farrar, David; Margosches, Elizabeth; Gupta, Kailash; Stitzel, Katherine; Carr, Gregory; Greene, Michael; Meyer, William; McCall, Deborah

    2002-01-01

    The authors have developed an improved version of the up-and-down procedure (UDP) as one of the replacements for the traditional acute oral toxicity test formerly used by the Organisation for Economic Co-operation and Development member nations to characterize industrial chemicals, pesticides, and their mixtures. This method improves the performance of acute testing for applications that use the median lethal dose (classic LD50) test while achieving significant reductions in animal use. It uses sequential dosing, together with sophisticated computer-assisted computational methods during the execution and calculation phases of the test. Staircase design, a form of sequential test design, can be applied to acute toxicity testing with its binary experimental endpoints (yes/no outcomes). The improved UDP provides a point estimate of the LD50 and approximate confidence intervals in addition to observed toxic signs for the substance tested. It does not provide information about the dose-response curve. Computer simulation was used to test performance of the UDP without the need for additional laboratory validation.

  3. Determination of gamma radiation lethal dose (LD50) and resveratrol cytotoxicity level in tumor cells line

    International Nuclear Information System (INIS)

    Magalhaes, Vanessa D.; Rogero, Sizue O.; Rogero, Jose R.; Cruz, Aurea S.

    2011-01-01

    Cancer is a disease with high incidence and it is considered a worldwide public health problem. Resveratrol is a polyphenol occurring naturally in a wide variety of plants according to response of ultraviolet radiation (UV) exposition or according to mechanical stress resulting of pathogens or chemical and physical agents. This polyphenol possesses a pharmacological activity of carcinogenesis inhibition in multiple levels. It also protects cells by scavenging the free radicals which are considered toxic products. These free radicals are formed of natural process of cell aging and also by incidence of ionizing radiation in the organism. Thus, resveratrol is considered as a cell radioprotector. On the other hand, in some elevated concentrations resveratrol may be considered as a radiosensitizing. The aim of this work was the determination of radiation lethal dose (LD 50 ) and also verifies the cytotoxicity level of resveratrol in tumor cells line: muco epidermoid pulmonary carcinoma cells (NCI-H292) and rhabdomyosarcoma cells (RD). The cytotoxicity test was performed by neutral red uptake assay. The results of resveratrol IC 50% in NCI-H292 cells was 192μM and in RD cells was 128μM; and RD cells gamma radiation LD 50 was 435Gy. (author)

  4. Determination of gamma radiation lethal dose (LD{sub 50}) and resveratrol cytotoxicity level in tumor cells line

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Vanessa D.; Rogero, Sizue O.; Rogero, Jose R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cruz, Aurea S. [Instituto Adolfo Lutz (IAL-SP) Secao de Culturas Celulares, SP (Brazil)

    2011-07-01

    Cancer is a disease with high incidence and it is considered a worldwide public health problem. Resveratrol is a polyphenol occurring naturally in a wide variety of plants according to response of ultraviolet radiation (UV) exposition or according to mechanical stress resulting of pathogens or chemical and physical agents. This polyphenol possesses a pharmacological activity of carcinogenesis inhibition in multiple levels. It also protects cells by scavenging the free radicals which are considered toxic products. These free radicals are formed of natural process of cell aging and also by incidence of ionizing radiation in the organism. Thus, resveratrol is considered as a cell radioprotector. On the other hand, in some elevated concentrations resveratrol may be considered as a radiosensitizing. The aim of this work was the determination of radiation lethal dose (LD{sub 50}) and also verifies the cytotoxicity level of resveratrol in tumor cells line: muco epidermoid pulmonary carcinoma cells (NCI-H292) and rhabdomyosarcoma cells (RD). The cytotoxicity test was performed by neutral red uptake assay. The results of resveratrol IC{sub 50%} in NCI-H292 cells was 192{mu}M and in RD cells was 128{mu}M; and RD cells gamma radiation LD{sub 50} was 435Gy. (author)

  5. Penentuan Nilai Ld50 Ekstrak Etanol Bawang Bombay (Allium Cepa L.) Pada Mencit Jantan

    OpenAIRE

    Amalia, Nofria Rizki

    2017-01-01

    131501110 LD50 (Lethal Dose50) merupakan salah satu parameter yang dapat menentukan derajat toksisitas suatu bahan. Uji toksisitas ini mengevaluasi besarnya dosis yang dapat menimbulkan efek toksik dan kematian pada hewan uji. Bawang bombay (Allium cepa L.) memiliki khasiat sebagaiantibakteri, antioksidan, antimutagenik, dan antiinflamasi. Tujuandaripenelitianiniadalahuntuk menentukan nilai LD50dariekstraketanolbawang bombaypadamencitjantan. Penelitianinimerupakanpenelitianeksperimental...

  6. Sensitivity of species to chemicals: dose-response characteristics for various test types (LC(50), LR(50) and LD(50)) and modes of action.

    Science.gov (United States)

    Hendriks, A Jan; Awkerman, Jill A; de Zwart, Dick; Huijbregts, Mark A J

    2013-11-01

    While variable sensitivity of model species to common toxicants has been addressed in previous studies, a systematic analysis of inter-species variability for different test types, modes of action and species is as of yet lacking. Hence, the aim of the present study was to identify similarities and differences in contaminant levels affecting cold-blooded and warm-blooded species administered via different routes. To that end, data on lethal water concentrations LC50, tissue residues LR50 and oral doses LD50 were collected from databases, each representing the largest of its kind. LC50 data were multiplied by a bioconcentration factor (BCF) to convert them to internal concentrations that allow for comparison among species. For each endpoint data set, we calculated the mean and standard deviation of species' lethal level per compound. Next, the means and standard deviations were averaged by mode of action. Both the means and standard deviations calculated depended on the number of species tested, which is at odds with quality standard setting procedures. Means calculated from (BCF) LC50, LR50 and LD50 were largely similar, suggesting that different administration routes roughly yield similar internal levels. Levels for compounds interfering biochemically with elementary life processes were about one order of magnitude below that of narcotics disturbing membranes, and neurotoxic pesticides and dioxins induced death in even lower amounts. Standard deviations for LD50 data were similar across modes of action, while variability of LC50 values was lower for narcotics than for substances with a specific mode of action. The study indicates several directions to go for efficient use of available data in risk assessment and reduction of species testing. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Radiotoxicity of α-emitter 211At for testes and its LD50 in mice

    International Nuclear Information System (INIS)

    Lin Ning; Jin Jiannan; Xia Qingjie; Zhang Shuyuan

    1998-01-01

    The radiotoxicity of α-emitter 211 At for testes in NIH strain mice was investigated by a singular i.p. injection with 5.55 x 10 5 Bq of Na 211 At, and the histopathological change of testicular cells was observed. Testes mass decreased rapidly at 6∼30 days post-injection. Histopathological observation revealed that some cells of interstitial tissue are irradiated to death at 6 days, the seminiferous tubules become empty at 30 days post-injection, and there is no spermatogenesis any more at this time. Additionally, the lethal dose (LD 50 ) of 211 At in the mice was investigated also by i.p injection and a LD 50 /7 of 8.14 x 10 4 Bq/g was measured

  8. Lethal dose of gamma radiation for eggs of Corcyra cephalonica (Stainton, 1865) (Lepidoptera: Pyralidae), rice moth

    International Nuclear Information System (INIS)

    Aguilar, J.A.D.; Arthur, V.

    1994-01-01

    The aim of this experiment was to observe the effects of gamma radiation on rice moth Corcyra cephalonica (STAINTON, 1865) eggs. The doses utilized in this experiment were 0; 25; 50; 75; 100; 125; 150; 175; 200 Gy. The experiment was carried out in a climatic room at 25 ± 2 0 C and 70 ± 10% R.H. It was observed that lethal dose LD50 and LD100 for eggs from adults reared by artificial diet were 16 and 75 Gy, respectively. (author). 14 refs, 1 fig, 1 tab

  9. Lethal doses of ionizing radiation versus endogenous level of superoxide dismutase

    Energy Technology Data Exchange (ETDEWEB)

    Lipecka, K; Domanski, T; Dniaszewska, K; Grabowska, B; Pietrowicz, D; Lindner, P; Cisowska, B; Gorski, H [Military Medical Academy, Lodz (Poland). Inst. of Occupational Medicine

    1982-06-22

    The stability of superoxide dismutase (SOD) as well as its activity distribution in a human population were investigated. The SOD activity level of the erythrocytes proved to be an index for the endogenous SOD activity in the whole body. In a rat population, having similar SOD frequency distribution as a human population, the mortality due to acute irradiation depended on the SOD level; after a single acute dose approximating the lethal dose (LD/sub 50/30/) the survival depended distinctly on the endogenous SOD activity level.

  10. Hematologic syndrome in man modeled from mammalian lethality

    International Nuclear Information System (INIS)

    Jones, T.D.

    1981-01-01

    Data on acute radiation lethality due to failure of the hematologic system in rats, mice, dogs, swine, monkeys and man are analyzed. Based on the available data, the mortality incidences for 1-100% levels can be computed directly if one has only an estimate of the dose lethal to 50% of the population (LD 50 ) for the mammalian strain and radiation environment of interest. The sole restriction is that the dose profile to the marrow be moderately uniform. If an LD 50 for any exposure situation has been measured, then one can readily scale to any desired situation through implicit-biological and empirical-physical relationships. The LD 50 for man, exposed to an isotropic cloud of photons, and knowledge of the bone-marrow dose profiles readily permit evaluation of the model for other levels of human mortality from different irradiating particles, partial body irradiation and spatially dependent and/or mixed radiation environments. (author)

  11. Caffeine protects mice against whole-body lethal dose of {gamma}-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    George, K.C.; Hebbar, S.A.; Kale, S.P.; Kesavan, P.C. [Biosciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    1999-06-01

    Administration of caffeine (1,3,7-trimethylxanthine), a major component of coffee, to Swiss mice at doses of 80 or 100 mg/kg body weight 60 min prior to whole-body lethal dose of {gamma}-irradiation (7.5 Gy) resulted in the survival of 70 and 63% of animals, respectively, at the above doses in contrast to absolutely no survivors (LD-100/25 days) in the group exposed to radiation alone. Pre-treatment with a lower concentration of caffeine (50 mg/kg) did not confer any radioprotection. The protection exerted by caffeine (80 mg/kg), however, was reduced from 70 to 50% if administered 30 min prior to irradiation. The trend statistics reveal that a dose of 80 mg/kg administered 60 min before whole-body exposure to 7.5 Gy is optimal for maximal radioprotection. However, caffeine (80 mg/kg) administered within 3 min after irradiation offered no protection. While there is documentation in the literature that caffeine is an antioxidant and radioprotector against the toxic pathway of radiation damage in a wide range of cells and organisms, this is the first report demonstrating unequivocally its potent radioprotective action in terms of survival of lethally whole-body irradiated mice. (author)

  12. Effect of Linezolid on the 50% Lethal Dose and 50% Protective Dose in Treatment of Infections by Gram-Negative Pathogens in Naive and Immunosuppressed Mice and on the Efficacy of Ciprofloxacin in an Acute Murine Model of Septicemia

    Science.gov (United States)

    Marra, Andrea; Lamb, Lucinda; Medina, Ivette; George, David; Gibson, Glenn; Hardink, Joel; Rugg, Jady; Van Deusen, Jeffrey

    2012-01-01

    Murine models of infection were used to study the effect of linezolid on the virulence of Gram-negative bacteria and to assess potential pharmacodynamic interactions with ciprofloxacin in the treatment of these infections, prompted by observations from a recent clinical trial. Naive and immunosuppressed mice were challenged with Klebsiella pneumoniae 53A1109, K. pneumoniae GC6658, and Pseudomonas aeruginosa UC12120 in acute sepsis and pulmonary infection models, using different serial dilutions of these pathogens (groups of 8 animals each). Linezolid (100 mg/kg/dose) was administered orally at 0.5 and 4.0 h postchallenge in the sepsis model and at 4 h postchallenge followed by 2 days of twice-daily treatment in the pulmonary model. Further, ciprofloxacin alone and in combination with oral linezolid was investigated in the sepsis model. Survival was assessed for 4 and 10 days postchallenge in the systemic and respiratory models, respectively. The data were fitted to a nonlinear regression analysis to determine 50% lethal doses (LD50s) and 50% protective doses (PD50s). A clinically relevant, high-dose regimen of linezolid had no significant effect on LD50 in these models. This lack of effect was independent of immune status. A combination of oral ciprofloxacin with linezolid yielded lower PD50s than oral ciprofloxacin alone (ciprofloxacin in combination, 8.4 to 32.7 mg/kg; oral ciprofloxacin, 39.4 to 88.3 mg/kg). Linezolid did not improve the efficacy of subcutaneous ciprofloxacin (ciprofloxacin in combination, 2.0 to 2.4 mg/kg; subcutaneous ciprofloxacin, 2.0 to 2.8 mg/kg). In conclusion, linezolid does not seem to potentiate infections caused by Gram-negative pathogens or to interact antagonistically with ciprofloxacin. PMID:22710118

  13. Optimization of irradiation conditions for determination of LD50 in pigs

    International Nuclear Information System (INIS)

    Prochazka, Z.; Hampl, J.; Sedlacek, M.; Rodak, L.

    1975-01-01

    Radiation LDsub(50/30) values were determined in 36 twelve-week-old pigs (with a mean body weight of 21 kg) exposed to whole-body X-ray irradiation on a revolvable table rotated at a rate of 2.5 rpm using the following conditions: 180 kV, 15 mA, focal distance 79 cm, HVT 0.9 mm Cu, dose rate 2.42 x 10 -3 to 2.68 x 10 -3 C kg -1 min -1 (9.4 to 10.4 R/min) depending upon the animal size. The coefficient of mean irradiation uniformity was 1.4. Under these conditions the LDsub(50/30) for pigs was found to be 5.89 x 10 -2 C kg -1 , (228.3 R) with the biological range of effectiveness being 5.22 x 10 -2 to 6.90 x 10 -2 C kg -1 (202.4 to 267.6 R) Further experiments on 77 pigs showed that the LD 50 determined in this study had actually the median lethal effect. (orig.) [de

  14. Determination of lethal doses 50 and 100 of propofol in lipid emulsion nor nanoemulsion intraperitoneally in miceDeterminação das doses letal 50 e 100 do propofol em nanoemulsão ou em emulsão lipídica pela via intraperitoneal em camundongos

    Directory of Open Access Journals (Sweden)

    Martielo Ivan Gehrcke

    2012-10-01

    Full Text Available The formulation of a drug can interfere with its absorption into the circulatory system and may result in changes in the dose required to achieve that particular effect. The aim of this study was to determine the lethal dose 50 (LD 50 and 100 (LD100 of a nanoemulsion of propofol and the lipid emulsion in mice intraperitoneally. One hundred sixty animals weighing 36.47±4.6g, which were distributed randomly into two groups: NANO and EMU who received propofol 1% in the nanoemulsion and lipid emulsion, respectively, intraperitoneally. Began with a dose of 250mg/kg (n=10 and from this isdecreased or increased the dose until achieving 0 and 100% of deaths in each group thus formed were seven subgroups in NANO (each subgroup n = 10 at doses 200, 250, 325, 350, 400, 425 and 475 mg/kg and in EMU eight subgroups (n= 10 each subset 250, 325, 350, 400, 425, 475, 525 and 575 mg/kg. In the CONTROL group (n=10 animals received saline in the largest volume used in the other groups to rule out death by the volume injected. Analysis of LD 50 and LD 100 were obtained by linear regression. The LD 50 was 320, 95 mg / kg and 4243, 51mg / kg and the LD 100 was445.99 mg / kg and 595.31 mg / kg to groups NANO and EMU, respectively. It follows that nanoemulsion is propofol in 25% more potent compared to the lipid emulsionintraperitoneally. A formulação de um fármaco pode interferir na sua absorção para o sistema circulatório, podendo resultar em alterações da dose necessária para que se consiga determinado efeito. O objetivo deste estudo foi determinar as doses letais 50 (DL 50 e 100 (DL100 do propofol em nanoemulsão e emulsão lipídica em camundongos pela via intraperitoneal. Foram utilizados 160 animais pesando 36,47 ± 4,6g, os quais foram distribuídos aleatoriamente em dois grupos: NANO e EMU que receberam propofol à 1% em nanoemulsão e em emulsão lipídica, respectivamente, pela via intraperitoneal. Iniciou-se com a dose de 250mg/kg (n=10 e a partir

  15. The Hematopoietic Syndrome of the Acute Radiation Syndrome in Rhesus Macaques: A Systematic Review of the Lethal Dose Response Relationship.

    Science.gov (United States)

    MacVittie, Thomas J; Farese, Ann M; Jackson, William

    2015-11-01

    Well characterized animal models that mimic the human response to potentially lethal doses of radiation are required to assess the efficacy of medical countermeasures under the criteria of the U.S. Food and Drug Administration "animal rule." Development of a model requires the determination of the radiation dose response relationship and time course of mortality and morbidity across the hematopoietic acute radiation syndrome. The nonhuman primate, rhesus macaque, is a relevant animal model that may be used to determine the efficacy of medical countermeasures to mitigate major signs of morbidity and mortality at selected lethal doses of total body irradiation. A systematic review of relevant studies that determined the dose response relationship for the hematopoietic acute radiation syndrome in the rhesus macaque relative to radiation quality, dose rate, and exposure uniformity has never been performed. The selection of data cohorts was made from the following sources: Ovid Medline (1957-present), PubMed (1954-present), AGRICOLA (1976-present), Web of Science (1954-present), and U.S. HHS REPORT (2002 to present). The following terms were used: Rhesus, total body-irradiation, total body x irradiation, TBI, irradiation, gamma radiation, hematopoiesis, LD50/60, Macaca mulatta, whole-body irradiation, nonhuman primate, NHP, monkey, primates, hematopoietic radiation syndrome, mortality, and nuclear radiation. The reference lists of all studies, published and unpublished, were reviewed for additional studies. The total number of hits across all search sites was 3,001. There were a number of referenced, unpublished, non-peer reviewed government reports that were unavailable for review. Fifteen studies, 11 primary (n = 863) and four secondary (n = 153) studies [n = 1,016 total nonhuman primates (NHP), rhesus Macaca mulatta] were evaluated to provide an informative and consistent review. The dose response relationships (DRRs) were determined for uniform or non-uniform total

  16. In vitro cell culture lethal dose submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: carolina_sm@hotmail.com; Ikeda, Tamiko I.; Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2009-07-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that {sup 60}Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  17. In vitro cell culture lethal dose submitted to gamma radiation

    International Nuclear Information System (INIS)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto; Ikeda, Tamiko I.; Cruz, Aurea S.

    2009-01-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that 60 Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  18. Universal LD50 predictions using deep learning

    Science.gov (United States)

    NICEATM Predictive Models for Acute Oral Systemic Toxicity LD50 entry Risa R. Sayre (sayre.risa@epa.gov) & Christopher M. Grulke Our approach uses an ensemble of multilayer perceptron regressions to predict rat acute oral LD50 values from chemical features. Features were genera...

  19. Interaction of radiation, Dihydroxyanthraquinone, and Adriamycin on the induction of acute lethality in mice

    International Nuclear Information System (INIS)

    Kimler, B.F.; Cox, G.G.; Reddy, E.K.

    1984-01-01

    The acute lethality induced by combinations of radiation, Dihydroxyanthraquinone (DHAQ), and Adriamycin (ADR) was investigated in mice. Whole-body irradiation produced acute lethality, with an LD-50/30 of approximately 6.5 Gy. ADR and DHAQ produced LD-50/30's of 14 and 4 mg/kg, respectively. When 10 mg/kg doses were fractionated into 5 x 2 mg/kg daily doses, both drugs were equally or more efficient at producing mortality, 90% by day 30. When 4 Gy radiation was combined with 5 mg/kg ADR or 5 mg/kg DHAQ, a response no greater than that produced by drug alone was obtained. However, when 5 mg/kg ADR was administered concomitantly with 5 mg/kg DHAQ, there was a less-than-additive induction of lethality, resulting in only 21% mortality by day 20. ADR and DHAQ (at doses of 5 mg/kg) were combined but with a 1 day interval between drugs, the protective effect was lost and animals died earlier than after either agent alone. At present, no definite explanation is available for this unusual protective effect of ADR against acute lethality induced by DHAQ

  20. The LD50 associated with exposure to the atomic bombing of Hiroshima

    International Nuclear Information System (INIS)

    Fujita, Shoichiro; Kato, Hiroo; Schull, W.J.

    1989-01-01

    Data on a total of 7,593 persons in Hiroshima who were in 2,518 wooden Japanese houses and exposed to A-bomb within 1.6 km from the hypocenter have been used to estimate the LD 50/60 . The effect of radiation shielding for these people in particularly well-characterized in the new dosimetry system DS86. A range of values emerge, varying slightly with the method of estimation used. This range, derived from DS86 marrow doses, and based on a linear fit to equally weighted estimates of the probabilities of death at various doses, is 2.3-2.6 Gy. A linear estimate in which the probabilities of death at the various doses are weighted by the inverse of their variances is somewhat lower, 2.2 Gy. These values may be underestimates of actual LD 50/60 because of inclusion of deaths in the first day, and the severely injured (burns, trauma) who survived the first day but succumbed later to their injuries. (author)

  1. Lethal dose determination of Cobalt-60 for adult Tribolium castaneum (Coleoptera: Tenebrionidae) and Cryptolestes ferrugineus (Coleoptera: Laemophloeidae)

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Anderson Aparecido, E-mail: potenza@biologico.sp.gov.br [Instituto Biologico, Centro de Pesquisa e Desenvolvimento de Protecao Ambiental, Sao Paulo, SP (Brazil); Potenza, Marcos Roberto, E-mail: fcreis@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Reis, Fabricio Caldeira; Sato, Mario Eidi, E-mail: mesato@biologico.sp.gov.br [Instituto Biologico, Centro Experimental Central, Laboratorio de Acarologia, Campinas, SP (Brazil)

    2015-07-01

    The insect infestation is a major problem in the grain storage. The pesticides are most widely used method for disinfestation and prevention. Treatment with gamma irradiation may increase the product shelf life without encountering formation of waste can be used in packaged foods and ready for commercialization, representing an important alternative to the use of pesticides. This study aimed to determine the immediate lethal dose of gamma radiation for adults of Tribolium castaneum and Cryptolestes ferrugineus. The study was conducted in the Instituto Biologico and the radiations held at the Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN, Sao Paulo city, using a multipurpose irradiator Cobalt-60 with 3.31 dose rate and 3.23 kGy in months of November/2014 and January/2015. Each experimental unit consisted of 20 adult insects, confined in a 10 mL polyethylene container. The experimental plots in number 10 per dose were subjected to increasing doses of gamma radiation: 0; 0.5; 0.75; 1.0; 1.25; 1.50; 1.75; 2.00; 2:50 and 3.00 kGy. Mortality was assessed within two to four hours after irradiation. The data were submitted to Probit analysis, using the POLO PLUS program. The LD90 to control 90% (LD90) to control adult Cryptolestes ferrugineus and Tribolium castaneum were 2.73 and 2.91 kGy, respectively. (author)

  2. Lethal dose determination of Cobalt-60 for adult Tribolium castaneum (Coleoptera: Tenebrionidae) and Cryptolestes ferrugineus (Coleoptera: Laemophloeidae)

    International Nuclear Information System (INIS)

    Farias, Anderson Aparecido; Potenza, Marcos Roberto; Reis, Fabricio Caldeira; Sato, Mario Eidi

    2015-01-01

    The insect infestation is a major problem in the grain storage. The pesticides are most widely used method for disinfestation and prevention. Treatment with gamma irradiation may increase the product shelf life without encountering formation of waste can be used in packaged foods and ready for commercialization, representing an important alternative to the use of pesticides. This study aimed to determine the immediate lethal dose of gamma radiation for adults of Tribolium castaneum and Cryptolestes ferrugineus. The study was conducted in the Instituto Biologico and the radiations held at the Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN, Sao Paulo city, using a multipurpose irradiator Cobalt-60 with 3.31 dose rate and 3.23 kGy in months of November/2014 and January/2015. Each experimental unit consisted of 20 adult insects, confined in a 10 mL polyethylene container. The experimental plots in number 10 per dose were subjected to increasing doses of gamma radiation: 0; 0.5; 0.75; 1.0; 1.25; 1.50; 1.75; 2.00; 2:50 and 3.00 kGy. Mortality was assessed within two to four hours after irradiation. The data were submitted to Probit analysis, using the POLO PLUS program. The LD90 to control 90% (LD90) to control adult Cryptolestes ferrugineus and Tribolium castaneum were 2.73 and 2.91 kGy, respectively. (author)

  3. 40 CFR 159.165 - Toxicological and ecological studies.

    Science.gov (United States)

    2010-07-01

    ... the median lethal dose (LD50), median lethal concentration (LC50) or irritation indices, are not... lethal dose (LD50), median lethal concentration (LC50), or median effective concentration (EC50). (2) At... less of the lowest LC50 or LD50 for a similar species. (4) For plants when tested at the maximum label...

  4. 用SPSS软件计算新药的LD50%The Calculation of LD50 in New Drugs with Software SPSS

    Institute of Scientific and Technical Information of China (English)

    周一平

    2003-01-01

    [目的]应用SPSS软件进行新药LD50的计算.[方法]将数据直接在视窗系统中输入和分析选项.[结果]自动输出相关参数和量效曲线.[结论]SPSS计算LD50简单、快速、直观和方便.

  5. A comparison of the survival (LD/sub 50/30/) of a number of inbred mouse strains after X and 60Co gamma irradiation

    International Nuclear Information System (INIS)

    Vacha, J.; Znojil, V.; Hola, J.; Sikulova, J.

    1984-01-01

    The value of LD/sub 50/30/ for X and 60 Co gamma radiation was ascertained for several inbred mouse strains and the significance of interstrain differences in these parameters determined. The rank order of strains according to LD/sub 50/30/ differs as between the two types of radiation with the exception of the strains BALB/c and B10.LP/Ph, which are the least resistant to radiation-induced lethality with both types of radiation. The strain C57BL/10ScSnPh is highly resistant to X irradiation. The relative biological effectiveness of 60 Co gamma radiation as compared with X-radiation from the point of view of lethality fluctuates between 0.748 and 0.952 in individual strains, with a mean value of 0.866 +- 0.033. The RBE values do not correlate with the radiosensitivity of the strain, but they do correlate with the relative contribution to erythropoiesis of the spleen. (author)

  6. Comparison of the survival (LD/sub 50/30/) of a number of inbred mouse strains after X and /sup 60/Co gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Vacha, J.; Znojil, V.; Hola, J.; Sikulova, J. (Ceskoslovenska Akademie Ved, Brno. Biofysikalni Ustav)

    1984-01-01

    The value of LD/sub 50/30/ for X and /sup 60/Co gamma radiation was ascertained for several inbred mouse strains and the significance of interstrain differences in these parameters determined. The rank order of strains according to LD/sub 50/30/ differs as between the two types of radiation with the exception of the strains BALB/c and B10.LP/Ph, which are the least resistant to radiation-induced lethality with both types of radiation. The strain C57BL/10ScSnPh is highly resistant to X irradiation. The relative biological effectiveness of /sup 60/Co gamma radiation as compared with X-radiation from the point of view of lethality fluctuates between 0.748 and 0.952 in individual strains, with a mean value of 0.866 +- 0.033. The RBE values do not correlate with the radiosensitivity of the strain, but they do correlate with the relative contribution to erythropoiesis of the spleen.

  7. Survival of bone marrow-engrafted mice subsequent to protection from lethal radiation by WR 2721

    International Nuclear Information System (INIS)

    Kinnamon, K.E.; Ketterling, L.L.; Ledney, G.D.; Lorenz, G.B.; Mioduszewski, R.J.; Stampfli, H.F.

    1980-01-01

    For the first time data are presented for animals treated with bone marrow cells after lethal radiation exposure while protected with WR 2721 (the single radioprotective chemical compound with the highest known dose reduction factor). The LD 50 30 (lethal dose to 50% in 30 days) for mice exposed to whole-body 60 Co radiation was elevated from 824 +- 8 rad in unprotected and untreated mice to (a) 1181 +- 33 rad in animals which received syngeneic bone marrow cells after exposure; (b) 1342 +- 27 rad in animals which received WR 2721 before radiation exposure; and (c) 1608 +- 33 rad in animals receiving both the radioprotective agent before exposure and bone marrow engraftment after exposure

  8. TOKSISITAS AKUT (LD50 DAN UJI GELAGAT EKSTRAK DAUN TEH HIJAU (CAMELLIA SINENSIS (LINN. KUNZE PADA MENCIT

    Directory of Open Access Journals (Sweden)

    Dian Sundari

    2012-09-01

    Full Text Available Among many kind of drinks, tea is the most preferable drink for Indonesian people. Compare to other drinks, tea has a lot of benefit to our healthy. Tea are able to prevent some diseases and help for recover process from simple diseasessuch as influenza, to chronic hard disease; that could cause death such as cancer. Variety of tea can be selected referring to the flavor. Acute toxicity test (Lethal Dose has been conducted of the extract of green tea leave (Camellia sinensis (Linn., Kunze. to the safety and symptom test as well. The test used mice as an animal experiments. The acute toxicity test use Weil, C.S (1915 method for the acute toxicity test and Paget. GE and Barnes, JM (1964 method for symptom test, high dosage under LD50 value are given to the mice, while green tea leave extract is made by percolation according to the method in Indonesian Pharmacope III. One kilogram of green tea powder produced an extract of 375 g or 37.5% of rendemen (sample. The result showed, the LD50 value of green lea leave extract was 3.303 (2.10 - 5.14 mg/10 g body weight i.p. By extrapolating the value as per oral in mice based on Gleason test (1969, the extract was classified as a Practically Non Toxic (PNT. The symptom test proved that green tea leave extract in a dosage of 2,7 mg/10 g body weight influenced the nerve system.   Key words : Camelia Sibebsis (Linn, Kunze, Green Tea, Safety, Toxicology

  9. Galantamine is a novel post-exposure therapeutic against lethal VX challenge

    International Nuclear Information System (INIS)

    Hilmas, Corey J.; Poole, Melissa J.; Finneran, Kathryn; Clark, Matthew G.; Williams, Patrick T.

    2009-01-01

    The ability of galantamine hydrobromide (GAL HBr) treatment to antagonize O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX)-induced lethality, impairment of muscle tension, and electroencephalographic (EEG) changes was assessed in guinea pigs. Guinea pigs were challenged with 16.8 μg/kg VX (2LD50). One min after challenge, animals were administered 0.5 mg/kg atropine sulfate (ATR) and 25 mg/kg pyridine-2-aldoxime methochloride (2-PAM). In addition, guinea pigs were given 0, 1, 2, 4, 8 or 10 mg/kg GAL as a post-exposure treatment immediately prior to ATR and 2-PAM. Animals were either monitored for 24-h survival, scheduled for electroencephalography (EEG) recording, or euthanized 60 min later for measurement of indirectly-elicited muscle tension in the hemidiaphragm. Post-exposure GAL therapy produced a dose-dependent increase in survival from lethal VX challenge. Optimal clinical benefits were observed in the presence of 10 mg/kg GAL, which led to 100% survival of VX-challenged guinea pigs. Based on muscle physiology studies, GAL post-exposure treatment protected the guinea pig diaphragm, the major effector muscle of respiration, from fatigue, tetanic fade, and muscular paralysis. Protection against the paralyzing effects of VX was dose-dependent. In EEG studies, GAL did not alter seizure onset for all doses tested. At the highest dose tested (10 mg/kg), GAL decreased seizure duration when administered as a post-exposure treatment 1 min after VX. GAL also reduced the high correlation associated between seizure activity and lethality after 2LD50 VX challenge. GAL may have additional benefits both centrally and peripherally that are unrelated to its established mechanism as a reversible acetylcholinesterase inhibitor (AChEI).

  10. Derivation of hazardous doses for amphibians acutely exposed to ionising radiation

    International Nuclear Information System (INIS)

    Fuma, Shoichi; Watanabe, Yoshito; Kawaguchi, Isao; Takata, Toshitaro; Kubota, Yoshihisa; Ban-nai, Tadaaki; Yoshida, Satoshi

    2012-01-01

    Derivation of effect benchmark values for each taxonomic group, which has been difficult due to lack of experimental effects data, is required for more adequate protection of the environment from ionising radiation. Estimation of effects doses from nuclear DNA mass and subsequent species sensitivity distribution (SSD) analysis were proposed as a method for such a derivation in acute irradiation situations for assumed nuclear accident scenarios. As a case study, 5% hazardous doses (HD 5 s), at which only 5% of species are acutely affected at 50% or higher lethality, were estimated on a global scale. After nuclear DNA mass data were obtained from a database, 50% lethal doses (LD 50 s) for 4.8 and 36% of the global Anura and Caudata species, respectively, were estimated by correlative equations between nuclear DNA mass and LD 50 s. Differences between estimated and experimental LD 50 s were within a factor of three. The HD 5 s obtained by the SSD analysis of these estimated LD 50 s data were 5.0 and 3.1 Gy for Anura and Caudata, respectively. This approach was also applied to the derivation of regional HD 5 s. The respective HD 5 s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan. This HD 5 value for the Japanese Anura was significantly higher than the global value, while Caudata had no significant difference in global and Japanese HD 5 s. These results suggest that this approach is also useful for derivation of regional benchmark values, some of which are likely different from the global values. - Highlights: ► A possible method was proposed for derivation of an effect benchmark value for each taxonomic group. ► 50% lethal doses were estimated from nuclear DNA mass in amphibian species. ► 5% hazardous doses (HD 5 s) were estimated by species sensitivity distribution. ► Respective HD 5 s were 5.0 and 3.1 Gy for Anura and Caudata globally. ► Respective HD 5 s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan.

  11. [Acute lethal effect of the commercial formulation of the insecticides Imidacloprid, Spinosad y Thiocyclam hidrogenoxalate in Bombus atratus (Hymenoptera: Apidae) workers].

    Science.gov (United States)

    Riaño Jiménez, Diego; Cure, José Ricardo

    2016-12-01

    The effect of insecticides on bees has gained great attention, however, there are few studies that explore this issue on Neotropical bees. Bombus atratus is a neotropical species broadly distributed in Colombia and is considered an important pollinator of both Andean ecosystems and agroecosystems. However, as for many wild bees species, the effect of insecticides on B. atratus is unknow. In this study we determined the acute median lethal dose (LD50) of commercial formulations of insecticides Imidacloprid, Spinosad and Thiocyclam hydrogen oxalate, widely used in Colombia to control several pests of important crops. The LD50 was carried out by oral and contact routes, following and modifying the EPPO and OECD guidelines to perform LD50 on A. mellifera. We evaluated five doses for each route and insecticide, in a total of 25 medium-size workers for each dose by duplicate. Mortality was registered at 24, 48 and 72 hours after the experiment; and data were analyzed with the Probit regression model. For Imidacloprid, contacts and oral LD50 were 0.048 µg/bee and 0.010 µg/bee, respectively. For Thiocyclam hydrogen oxalate, topical and oral LD50 were 0.244 µg/bee and 0.056 µg/bee, respectively. For Spinosad, the oral LD50 corresponded to 0.28 µg/bee; it was not possible to establish the LD50 for the contact route. The Hazard Quotient (HQ) and Index of Relative Toxicity indicated that all three active ingredients are highly toxic. We discussed the risk of the insecticides use on B. atratus, considering their chemical nature.

  12. Dependence between LD50 for Rodents and LC50 for Adult Fish and Fish Embryos.

    Science.gov (United States)

    Zolotarev, K V; Belyaeva, N F; Mikhailov, A N; Mikhailova, M V

    2017-02-01

    We revealed empirical dependences between common logarithm of a ratio of rat oral LD 50 to LC a 50 for adult fish and lgP for 50 different chemicals; and common logarithm of a ratio of the oral LD 50 in rodents to LC e 50 for fish embryos and lgP for 30 different chemicals. The dependences were obtained by constructing a trend line between experimental points and calculation of Pearson's R correlation coefficient as a measure of regression significance. These dependences can show the influence of substance lipophilicity on its toxicity for aquatic organisms comparing to mammals.

  13. Priming dose of phenylhydrazine protects against hemolytic and lethal effects of 2-butoxyethanol

    International Nuclear Information System (INIS)

    Palkar, Prajakta S.; Philip, Binu K.; Reddy, Ramesh N.; Mehendale, Harihara M.

    2007-01-01

    Protection against a high dose of a toxicant by prior exposure to another toxicant is called heteroprotection. Our objective was to establish a heteroprotection model in RBCs. Female Sprague Dawley rats treated with an LD90 dose of 2-butoxyethanol (BE, 1500 mg/kg in water, 5 ml/kg po) 14 days after priming with 0.9% NaCl suffered 90% mortality by 15 days, whereas all rats receiving the LD90 dose of BE 14 days after priming with phenylhydrazine (PHZ, 125 mg/kg in 0.9% NaCl, 3 ml/kg po) survived. Hematocrit decreased from normal 45% to 24% by day 3 after PHZ priming and improved thereafter. Increasing the time interval between the priming and LD90 dose to 21 days abolished the heteroprotection. RBCs obtained on days 7 and 14 after PHZ priming unlike those on day 21 were resilient to the hemotoxic metabolite of BE, butoxyacetic acid (BAA). Unaltered hepatic alcohol and aldehyde dehydrogenase activities upon PHZ priming suggested that bioactivation of BE to BAA was unaffected. Lower renal (6 and 12 h) and hepatic (12 h) BAA levels and 3 fold higher excretion of BAA in PHZ-primed rat urine suggested a protective role of toxicokinetics. Higher erythropoietin, reticulocytes, and resiliency of PHZ-primed rat RBCs indicated that newly formed RBCs are resilient to hemolytic BAA. The antioxidant levels in the PHZ-primed rat RBCs did not indicate a protective role in heteroprotection. In conclusion, the resistance of PHZ-primed rats against BE-induced hemotoxicity and lethality is mediated by a combination of altered toxicokinetics, robust erythropoiesis, and resiliency of new RBCs

  14. Models for pulmonary lethality and morbidity after irradiation from internal and external sources

    International Nuclear Information System (INIS)

    Scott, B.R.; Filipy, R.E.; Hahn, E.F.

    1989-05-01

    This report provides a hazard-function model for estimating the risk of death from radiation pneumonitis and/or pulmonary fibrosis following a light-water nuclear power accident. A similar model is also provided for estimating the prevalence of respiratory functional morbidity among those that survive death from acute effects. Hazard-function models for lethality and for morbidity were constructed using the cumulative hazard estimator H, which is related to the risk estimator R through the equation R = 1-exp(-H). The estimator H can be calculated using information provided in the report. The method of calculation depends on the exposure scenario. In general, the total normalized dose X for lethality or for morbidity is calculated. For lethality, X = 1 corresponds to a median lethal dose (LD 50 ); for morbidity, X = 1 corresponds to a median effective dose (ED 50 ). H is related to X by the equation H = 1n(2)X/sup V/, where V depends on the type of radiation (or radiations) involved. Contributions to X can arise from each of two main modes of exposure: (1) brief exposure of the lung, at a relatively high dose rate, to mainly external gammas, followed by (2) chronic internal alpha, and/or beta, and/or gamma irradiation of the lung. Equations are provided for calculating the contributions to X from both modes of exposure. 73 refs., 16 figs., 2 tabs

  15. Perbandingan Pemberian Brodifakum Ld50 Dan Ld100 Terhadap Perubahan Gambaran Histopatologi Usus Halus Tikus Wistar

    OpenAIRE

    Al Ayoubi, Alfian Salahudin; Dhanardhono, Tuntas; Bhima, Sigit Kirana Lintang

    2016-01-01

    Background : Brodifacoum is an anticoagulant substance which usually used as pest control, but this substance has a poisoning effect the body. Brodifacoum is absorbed through gastrointestinal tract which can cause the disorder of blod clotting by slowing down the process of epoxide reductase of vitamin-K.Aim : To know the comparison of Histopathology Rattus norvegicus Intestine against brodifacoum administration LD50 and LD100.Methods :This study was an experimental study with post test only ...

  16. Frequencies of aneuploidy and dominant lethal mutations in young female mice induced by low dose γ-rays

    International Nuclear Information System (INIS)

    Yao Suyan; Zhang Chaoyang; Dai Lianlian; Gao Changwen

    1991-01-01

    Relationship between aneuploidy, dominant lethal mutations and doses in young feral mice induced by low dose γ-rays was examined. The results suggest that the frequencies of aneuploidy of embryos increased at 0.15 Gy, but increases at over 0.50 Gy after irradiation in groups. The frequencies of aneuploidy and dominant lethal mutations increased with increasing doses and fitted linear relationship. This dose-response relationship of trisomic was not significant. The frequency of dominant lethal mutations induced by 60 Co γ irradiation is 5.59%. The effect of dominant lethal mutation is higher than that of the aneuploidy

  17. Perbandingan Pemberian Brodifakum Ld50 Dan Ld100 Terhadap Perubahan Gambaran Patologi Anatomi Gaster Tikus Wistar

    OpenAIRE

    Renardi P., Ricky; Dhanardhono, Tuntas; Bhima, Sigit Kirana Lintang

    2015-01-01

    Background : Brodifakum is a substance that often used as rat poison and disrupt the process of blood coagulation.As a result of this disorder can cause bleeding in vital organs of rat. This study was conducted to assess the gastric anatomic pathology due to Brodifakum. Aim : To know the comparison of Anatomical Pathology Rattus norvegicus Gastric againstbrodifacoum administration LD50 and LD100.Methods :This study was an experimental study with post test only group design. The sample of this...

  18. Hormone-dependence of sarin lethality in rats: Sex differences and stage of the estrous cycle

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Carl D., E-mail: carl.d.smith179.mil@mail.mil; Wright, Linnzi K.M.; Garcia, Gregory E.; Lee, Robyn B.; Lumley, Lucille A.

    2015-09-15

    Chemical warfare nerve agents (CWNAs) are highly toxic compounds that cause a cascade of symptoms and death, if exposed casualties are left untreated. Numerous rodent models have investigated the toxicity and mechanisms of toxicity of CWNAs, but most are limited to male subjects. Given the profound physiological effects of circulating gonadal hormones in female rodents, it is possible that the daily cyclical fluctuations of these hormones affect females' sensitivity to the lethal effects of CWNAs, and previous reports that included female subjects did not control for the stage of the hormonal cycle. The aim of the current study was to determine the 24-hour median lethal dose (LD{sub 50}) of the CWNA sarin in male, ovariectomized (OVEX) female, and female rats during different stages of the estrous cycle (diestrus, proestrus, and estrus). Additionally, baseline activity levels of plasma acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were measured to determine differences among the groups. Results indicated that females in proestrus had a significantly higher LD{sub 50} of sarin compared to OVEX and estrous females. Although some sex differences were observed in the activity levels of plasma esterases, they were not consistent and likely not large enough to significantly affect the LD{sub 50}s. These results suggest that hormonal cyclicity can influence the outcome of CWNA-related studies using female rodents, and that this variability can be minimized by controlling for the stage of the cycle. Additional research is necessary to determine the precise mechanism of the observed differences because it is unlikely to be solely explained by plasma esterase activity. - Highlights: • The LD{sub 50} of sarin was determined in female rats throughout the stages of the estrous cycle. • Females in proestrus had a significantly higher LD{sub 50} compared to estrous or ovariectomized females. • No sex differences were observed between male and female

  19. Relative biological effectiveness measurements using murine lethality and survival of intestinal and hematopoietic stem cells after Fermilab neutrons compared to JANUS reactor neutrons and 60Co gamma rays

    International Nuclear Information System (INIS)

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

    1984-01-01

    The relative biological effectiveness (RBE) of the 25-MeV (average energy) neutron beam at the Fermi National Accelerator Laboratory was measured using murine bone marrow (LD/sub 50/30/) and gut (LD/sub 50/6/) lethality and killing of hematopoietic colony forming units (CFU-S) or intestinal clonogenic cells (ICC). The LD/sub 50/30/ and LD/sub 50/6/ for mice exposed to the Fermilab neutron beam were 6.6 and 8.7 Gy, respectively, intermediate between those of JANUS neutrons and 60 Co γ rays. The D 0 values for CFU-S and ICC were 47 cGy and 1.05 Gy, respectively, also intermediate between the lowest values found for JANUS neutrons and the highest values found after 60 Co γ rays. The split-dose survival ratios for CFU-S at intervals of 1-6 hr between doses were essentially 1.0 for both neutron sources. The 3-hr split-dose survival ratios for ICC were 1.0 for JANUS neutrons, 1.85 for Fermilab neutrons, and 6.5 for 60 Co γ rays. The RBE estimates for LD/sub 50/30/ were 1.5 and 2.3 for Fermilab and JANUS neutrons, respectively. Based on LD/sub 50/6/, the RBEs were 1.9 (Fermilab) and 3.0 (JANUS). The RBEs for CFU-S D 0 were 1.4 (Fermilab) and 1.9 (JANUS) and for jejunal microcolony D 0 1.4 (Fermilab) and 2.8 (JANUS)

  20. Report on the changes of LD50 of Bee venom Herbal Acupuncture

    Directory of Open Access Journals (Sweden)

    Ki Rok Kwon

    2005-02-01

    Full Text Available Objectives : This experiment was conducted to reevaluate LD50 of Korean bee venom acupuncture as many changes have occurred over the years. Methods : ICR mice were used as the experiment animals and bee venom acupuncture was manufactured under the protocols of Korean Institute of herbal Acupuncture. Based on the previous reports, experiment was divided into pre and main sections. Results : 1. Presumed LD50 value is at 5.25mg/kg. 2. Deaths of experiment animals occurred within 48 hours. 3. Reduced toxicity of the bee venom acupuncture is likely to be the results of more refined manufacturing process and production. Conclusion : Comparing with the values of the previous results, toxicity of the bee venom acupuncture showed significant changes and more accurate findings on LD50 value must be accomplished to lead further studies on the bee venom acupuncture.

  1. Left ventricular function during lethal and sublethal endotoxemia in swine

    International Nuclear Information System (INIS)

    Goldfarb, R.D.; Nightingale, L.M.; Kish, P.; Weber, P.B.; Loegering, D.J.

    1986-01-01

    Previous studies suggested that after a median lethal dose (LD 50 ) of endotoxin, cardiac contractility was depressed in nonsurviving dogs. The canine cardiovascular system is unlike humans in that dogs have a hepatic vein sphincter that is susceptible to adrenergic stimulation capable of raising hepatic and splanchnic venous pressures. The authors retested the hypothesis that lethality after endotoxin administration is associated with cardiac contractile depression in pigs, because of the hepatic circulation in this species is similar to that of humans. They compared cardiac mechanical function of pigs administered a high dose (250 μg/kg) or a low dose (100 μg/kg) endotoxin by use of the slope of the end-systolic pressure-diameter relationship (ESPDR) as well as other measurements of cardiac performance. In all the pigs administered a high dose, ESPDR demonstrated a marked, time-dependent depression whereas we observed no significant ESPDR changes after low endotoxin doses. The other cardiodynamic variables were uninterpretable, due to the significant changes in heart rate, end-diastolic diameter (preload), and aortic diastolic pressure (afterload). Plasma myocardia depressant factor activity accumulated in all endotoxin-administered animals, tending to be greater in the high-dose group. In this group, both subendocardial blood flow and global function were depressed, whereas pigs administered the low dose endotoxin demonstrated slight, but nonsignificant, increases in flow and function. These observations indicate that myocardial contractile depression is associated with a lethal outcome to high doses of endotoxin. Myocardial perfusion was measured using radiolabeled microspheres infused into the left atria

  2. Biological effects of nuclear war: Acute effects of radiation; the LD-50 value

    International Nuclear Information System (INIS)

    Ohkita, T.; Rotblat, J.

    1987-01-01

    Recent surveys carried out in Japan in connection with the reassessment of the dosimetry for long-term effects provided an opportunity for another look at the acute effects of radiation and a recalculation of the LD-50 value. The recalculation gave an LD-50 value which is two to three times lower than had been assumed before. It means that in a nuclear war the number of fatalities due to exposure to radiation would be considerably higher than thought hitherto. 11 refs, 5 figs, 2 tabs

  3. Toxicidad oral a 60 días del aceite de sacha inchi (Plukenetia volubilis L. y linaza (Linum usitatissimum L. y determinación de la dosis letal 50 en roedores Oral toxicity at 60-days of sacha inchi oil (Plukenetia volubilis L. and linseed (Linum usitatissimum L., and determination of lethal dose 50 in rodents

    Directory of Open Access Journals (Sweden)

    Arilmi Gorriti

    2010-09-01

    Full Text Available Objetivos. Evaluar la toxicidad oral a 60 días y determinar la dosis letal 50 (DL 50 de los aceites crudos de sacha inchi (Plukenetia volubilis L. y linaza (Linum ussitatisimum en ratas Holtzman y en ratones cepa Balb C57, respectivamente. Materiales y métodos. Para la evaluación de la toxicidad oral a dosis repetida por 60 días se utilizó 24 ratas macho Holtzman divididos en tres grupos de ocho cada uno, los grupos fueron: solución salina fisiológica 4 mL/kg (SSF, aceite de sacha inchi 0,5 mL/kg (SI05 y aceite de linaza 0,5 mL/kg (L05, durante el experimento se controló semanalmente el peso corporal y signos de toxicidad en los grupos investigados, así como colesterol total, HDL, triglicéridos, glucosa, urea, TGP y fosfatasa alcalina a los 30 y 60 días de iniciado el experimento. Para la evaluación de la DL50 se usó ratones macho cepa Balb C57 en grupos de diez animales, se administró por vía oral dosis crecientes de aceites crudos hasta alcanzar 1 mL/kg (37 g/kg; Resultados. Los parámetros séricos en las ratas indican que no existe toxicidad alguna a los 60 días y que la administración de los aceites disminuyeron los niveles de colesterol, triglicéridos e incrementaron el HDL con respecto al grupo control. La DL50 muestra que los aceites crudos de sacha inchi y linaza presentan dosis por encima de los 37 g/kg de masa corporal. Conclusiones. Los aceites de sacha inchi y linaza son inocuos a 60 días y presentan una DL50 por encima de los 37 g/kg de animal.Objectives. To evaluate the oral toxicity at 60 days and to determine the lethal dose 50 (LD 50 of raw sacha inchi (Plukenetia volubilis L. and linseed (Linum ussitatisimum oils in Holtzman rats and mice of the strain Balb C57 respectively. Materials and methods. For the evaluation of the oral toxicity of repeated doses for 60 days, 24 male Holtzman rats were used, divided in three groups of 8 each, the groups were: physiologic saline solution 4 mL/kg (FSS, sacha inchi oil

  4. Phytochemistry, Brine shrimp lethality and mice acute oral toxicity studies on seed extracts of Vernonia anthelmintica.

    Science.gov (United States)

    Jamil, Subia; Khan, Rafeeq Alam; Afroz, Syeda; Ahmed, Shadab

    2016-11-01

    Despite the widespread use of Vernonia anthelmintica seeds in traditional medicine, the need to establish the safety of the Vernonia anthelmintica is required to ascertain the safe use of this herbal medicine. The aim of the present study is to establish the acute toxicity profile of different extracts of Vernonia anthelmintica. Hexane and ethanol extract of Vernonia Anthelmintica has been studied for its brine shrimp lethality potential. Water decoction (WDVA), Hexane (HEVA) and Ethanol (EEVA) extracts of Vernonia anthelmintica has also been evaluated for their in-vivo acute oral toxicity in mice by Lorke's method. Phytochemistry of all three extracts was also evaluated for the presence of their secondary metabolites. All three extracts showed the presence of flavonoids and terpenoids, while alkaloids, tannins and fixed oils were present in HEVA and EEVA. Furthermore EEVA also showed presence of carbohydrates and HEVA also showed the presence of cardiac glycosides. Ethanol and hexane extracts of Vernonia anthelmintica showed a positive cytotoxicity in brine shrimp lethality test at 24 hours with LC50 104.16 (224.0-48.05)μg/ml and 216.11μg/ml (378.2-128.7) respectively as compared to standard drug etoposide LC50 7.46μg/ml. The oral LD50 for EEVA, HEVA and WDVA in mice by Lorke's method was greater than 5000mg/kg. The result of brine shrimp lethality test clearly exhibited the presence of bioactive compounds with cytotoxic potential; however seems to be safe for oral use since LD50 was higher than 5000mg/kg and thus safety of acute dosing in vivo practices is justified.

  5. Dosis letal 50 de lorazepam en ratón (Mus musculus Albino, cepa suizo-icr

    Directory of Open Access Journals (Sweden)

    Francisco Alejandro Múnera G.

    2000-10-01

    Full Text Available Objective: The lethal dose 50 (LD50 of  lorazepam in albino mice (Musmusculus, swiss ICR strain, was determined as a first step in the study of the conjoint toxicity of admixtures of scopolamine and benzodiazepines ("new burundanga". Method: Sixty adult male mice were randomly assigned to five experimental groups and to a control one. The dose of lorazepam administered intraperitoneally to each group was: group 1,10 mg kg_1; group 11,20 mg kgI; group 111,40mg kgL; group IV,80mgkg'; group V,160mg kg-l.The control group received only the vehicle solution. Mortality was recorded during 15 days after injection. Necropsies were performed to all the mice dead during the assay and to the survivors. Data were processed using probit analysis and survival analysis. Results: Estimated LD50 were 90.71 mg kg- 1, with 95% confidence range of 65,02to 150,13mg kg- 1.Deaths occurred within the first six days after injection of doses higher than 80 mg kg:', mostly during the first 48 hours. Conclusions: The estimated LD50 of  lorazepam in this experiment almost doubles the reported one, this finding suggests a higher resistance of the mice strain used in this experiment The critic period for lorazepam poisoning spans the first 48 hours.

  6. Acute and Cumulative Effects of Unmodified 50-nm Nano-ZnO on Mice.

    Science.gov (United States)

    Kong, Tao; Zhang, Shu-Hui; Zhang, Ji-Liang; Hao, Xue-Qin; Yang, Fan; Zhang, Cai; Yang, Zi-Jun; Zhang, Meng-Yu; Wang, Jie

    2018-01-02

    Nanometer zinc oxide (nano-ZnO) is widely used in diverse industrial and agricultural fields. Due to the extensive contact humans have with these particles, it is crucial to understand the potential effects that nano-ZnO have on human health. Currently, information related to the toxicity and mechanisms of nano-ZnO is limited. The aim of the present study was to investigate acute and cumulative toxic effects of 50-nm unmodified ZnO in mice. This investigation will seek to establish median lethal dose (LD50), a cumulative coefficient, and target organs. The acute and cumulative toxicity was investigated by Karber's method and via a dose-increasing method, respectively. During the experiment, clinical signs, mortality, body weights, hematology, serum biochemistry, gross pathology, organ weight, and histopathology were examined. The LD50 was 5177-mg/kg·bw; the 95% confidence limits for the LD50 were 5116-5238-mg/kg·bw. It could be concluded that the liver, kidney, lung, and gastrointestinal tract were target organs for the 50-nm nano-ZnO acute oral treatment. The cumulative coefficient (K) was 1.9 which indicated that the cumulative toxicity was apparent. The results also indicated that the liver, kidney, lung, and pancrea were target organs for 50-nm nano-ZnO cumulative oral exposure and might be target organs for subchronic and chronic toxicity of oral administered 50-nm ZnO.

  7. Evaluation of Inhaled Versus Deposited Dose Using the Exponential Dose-Response Model for Inhalational Anthrax in Nonhuman Primate, Rabbit, and Guinea Pig.

    Science.gov (United States)

    Gutting, Bradford W; Rukhin, Andrey; Mackie, Ryan S; Marchette, David; Thran, Brandolyn

    2015-05-01

    The application of the exponential model is extended by the inclusion of new nonhuman primate (NHP), rabbit, and guinea pig dose-lethality data for inhalation anthrax. Because deposition is a critical step in the initiation of inhalation anthrax, inhaled doses may not provide the most accurate cross-species comparison. For this reason, species-specific deposition factors were derived to translate inhaled dose to deposited dose. Four NHP, three rabbit, and two guinea pig data sets were utilized. Results from species-specific pooling analysis suggested all four NHP data sets could be pooled into a single NHP data set, which was also true for the rabbit and guinea pig data sets. The three species-specific pooled data sets could not be combined into a single generic mammalian data set. For inhaled dose, NHPs were the most sensitive (relative lowest LD50) species and rabbits the least. Improved inhaled LD50 s proposed for use in risk assessment are 50,600, 102,600, and 70,800 inhaled spores for NHP, rabbit, and guinea pig, respectively. Lung deposition factors were estimated for each species using published deposition data from Bacillus spore exposures, particle deposition studies, and computer modeling. Deposition was estimated at 22%, 9%, and 30% of the inhaled dose for NHP, rabbit, and guinea pig, respectively. When the inhaled dose was adjusted to reflect deposited dose, the rabbit animal model appears the most sensitive with the guinea pig the least sensitive species. © 2014 Society for Risk Analysis.

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

    Science.gov (United States)

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

    2011-12-01

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

  9. Effect of dose-rate on the frequency of X-linked lethal mutation in the nematode Panagrellus redivivus

    International Nuclear Information System (INIS)

    Ager, D.

    1984-01-01

    A total X-ray dose of 50 Gy was applied to the nematode Panagrellus redivivus using dose-rates ranging from 0.23 Gy/min to 10.49 Gy/min, and the frequency of lethal X-chromosomes was determined. This frequency ranged from approximately 1.6% at the lower dose-rate to 4.3% at the highest dose-rate, indicating a dose-rate dependency of mutation frequency in the spermatogonia and oogonia of this organism. (orig.)

  10. 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)

  11. 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)

  12. RBE/absorbed dose relationship of d(50)-Be neutrons determined for early intestinal tolerance in mice

    International Nuclear Information System (INIS)

    Gueulette, J.; Wambersie, A.

    1978-01-01

    RBE/absorbed dose relationship of d(50)-Be neutrons (ref.: 60 Co) was determined using intestinal tolerance in mice (LD50) after single and fractionated irradiation. RBE is 1.8 for a single fraction (about 1000 rad 60 Co dose); it increases when decreasing dose and reaches the plateau value of 2.8 for a 60 Co dose of about 200 rad. This RBE value is used for the clinical applications with the cyclotron 'Cyclone' at Louvain-la-Neuve [fr

  13. The recovery of bone marrow derived GM-CFU in baboons unilaterally exposed to a total body LD50/30d mixed neutron-gamma irradiation

    International Nuclear Information System (INIS)

    Herodin, F.; Orfeuvre, H.; Janodet, D.; Mestries, J.C.; Fatome, M.

    1990-01-01

    The unilateral exposure of baboons to a total body LD 50/30d mixed neutron/gamma irradiation was characterized to be non uniform in dose distribution. The pattern of recovery of granulocyte-macrophage progenitors in bone marrow samples collected from entrance and exit sides respectively is consistent with this observed heterogeneity [fr

  14. Relative effect of radiation dose rate on hemopoietic and nonhemopoietic lethality of total-body irradiation

    International Nuclear Information System (INIS)

    Peters, L.J.; McNeill, J.; Karolis, C.; Thames, H.D. Jr.; Travis, E.L.

    1986-01-01

    Experiments were undertaken to determine the influence of dose rate on the toxicity of total-body irrdiation (TBI) with and without syngeneic bone-marrow rescue in mice. The results showed a much greater dose-rate dependence for death from nonhemopoietic toxicity than from bone-marrow ablation, with the ratio of LD 50 's increasing from 1.73 at 25 cGy/min to 2.80 at 1 cGy/min. At the higher dose rates, dose-limiting nonhemopoietic toxicity resulted from late organ injury, affecting the lungs, kidneys, and liver. At 1 cGy/min the major dose-limiting nonhemopoietic toxicity was acute gastrointestinal injury. The implications of these results in the context of TBI in preparation for bone-marrow transplantation are discussed. 15 refs., 4 figs

  15. Stand van zaken LD50/LC50 testen : Verfijning, vermindering en vervanging van dierproeven en mogelijkheden tot interventies

    OpenAIRE

    van der Ven L; Ezendam J; VTS; V&Z

    2014-01-01

    Het RIVM heeft geïnventariseerd hoeveel proefdieren worden gebruikt voor testen die uitzoeken bij welke dosering of concentratie van een stof 50 procent van de dieren sterft (zogeheten LD50/LC50-testen). Deze testen zijn in principe verboden en worden alleen met ontheffing toegepast als er geen alternatieve methoden mogelijk zijn. De inventarisatie is op verzoek van de staatssecretaris van Economische Zaken gemaakt. Hieruit blijkt dat in Nederland jaarlijks voor dit type testen tussen de 570 ...

  16. X-ray lethality in diabetic rats

    International Nuclear Information System (INIS)

    Cember, H.; Thorson, T.M. Jr.

    1978-01-01

    Rats were made diabetic with streptozotocin and were irradiated with X-rays at various exposure levels in order to determine the LD-50/30 day dose. Non-diabetic control rats were exposed in a similar manner. The LD-50 exposures for the diabetic rats and the control rats were 436 R, and 617 R respectively. In view of the high prevalence of diabetes among the adult population, this finding may have important implications for diabetic workers who may be exposed accidentally to high levels of ionizing radiation

  17. LD-aminopterin in the canine homologue of human atopic dermatitis: a randomized, controlled trial reveals dosing factors affecting optimal therapy.

    Science.gov (United States)

    Zebala, John A; Mundell, Alan; Messinger, Linda; Griffin, Craig E; Schuler, Aaron D; Kahn, Stuart J

    2014-01-01

    Options are limited for patients with atopic dermatitis (AD) who do not respond to topical treatments. Antifolate therapy with systemic methotrexate improves the disease, but is associated with adverse effects. The investigational antifolate LD-aminopterin may offer improved safety. It is not known how antifolate dose and dosing frequency affect efficacy in AD, but a primary mechanism is thought to involve the antifolate-mediated accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). However, recent in vitro studies indicate that AICAR increases then decreases as a function of antifolate concentration. To address this issue and understand how dosing affects antifolate efficacy in AD, we examined the efficacy and safety of different oral doses and schedules of LD-aminopterin in the canine model of AD. This was a multi-center, double-blind trial involving 75 subjects with canine AD randomized to receive up to 12 weeks of placebo, once-weekly (0.007, 0.014, 0.021 mg/kg) or twice-weekly (0.007 mg/kg) LD-aminopterin. The primary efficacy outcome was the Global Score (GS), a composite of validated measures of disease severity and itch. GS improved in all once-weekly cohorts, with 0.014 mg/kg being optimal and significant (43%, P<0.01). The majority of improvement was seen by 8 weeks. In contrast, GS in the twice-weekly cohort was similar to placebo and worse than all once-weekly cohorts. Adverse events were similar across all treated cohorts and placebo. Once-weekly LD-aminopterin was safe and efficacious in canine AD. Twice-weekly dosing negated efficacy despite having the same daily and weekly dose as effective once-weekly regimens. Optimal dosing in this homologue of human AD correlated with the concentration-selective accumulation of AICAR in vitro, consistent with AICAR mediating LD-aminopterin efficacy in AD.

  18. LD-aminopterin in the canine homologue of human atopic dermatitis: a randomized, controlled trial reveals dosing factors affecting optimal therapy.

    Directory of Open Access Journals (Sweden)

    John A Zebala

    Full Text Available Options are limited for patients with atopic dermatitis (AD who do not respond to topical treatments. Antifolate therapy with systemic methotrexate improves the disease, but is associated with adverse effects. The investigational antifolate LD-aminopterin may offer improved safety. It is not known how antifolate dose and dosing frequency affect efficacy in AD, but a primary mechanism is thought to involve the antifolate-mediated accumulation of 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR. However, recent in vitro studies indicate that AICAR increases then decreases as a function of antifolate concentration. To address this issue and understand how dosing affects antifolate efficacy in AD, we examined the efficacy and safety of different oral doses and schedules of LD-aminopterin in the canine model of AD.This was a multi-center, double-blind trial involving 75 subjects with canine AD randomized to receive up to 12 weeks of placebo, once-weekly (0.007, 0.014, 0.021 mg/kg or twice-weekly (0.007 mg/kg LD-aminopterin. The primary efficacy outcome was the Global Score (GS, a composite of validated measures of disease severity and itch. GS improved in all once-weekly cohorts, with 0.014 mg/kg being optimal and significant (43%, P<0.01. The majority of improvement was seen by 8 weeks. In contrast, GS in the twice-weekly cohort was similar to placebo and worse than all once-weekly cohorts. Adverse events were similar across all treated cohorts and placebo.Once-weekly LD-aminopterin was safe and efficacious in canine AD. Twice-weekly dosing negated efficacy despite having the same daily and weekly dose as effective once-weekly regimens. Optimal dosing in this homologue of human AD correlated with the concentration-selective accumulation of AICAR in vitro, consistent with AICAR mediating LD-aminopterin efficacy in AD.

  19. Effects of gamma irradiation on fresh and dry weights of plant parts in Physalis L

    International Nuclear Information System (INIS)

    Raghava, R.P.; Raghava, Nisha

    1989-01-01

    20 KR irradiations on Physalis peruviana L. and P. angulta L. seem to be the best dose for plant growth. 40 and 50 KR doses were inhibitory to both, and 50 KR was found to be almost lethal (LD 50 ). (author). 14 refs

  20. LD50 and inviably dose of gamma radiation for Musca domestica L., 1758 (diptera: muscidae) pupae aged 1, 2, 3 and 4 days

    International Nuclear Information System (INIS)

    Itepan, Natanael M.; Itepan, Sara E.D.Z.

    2013-01-01

    This experiment was carried out in Biological Control of Domestic Fly 'Eduardo Hiroshi Mizumoto' Laboratory at Entomology and Acarology Department (LEA/ESALQ/USP) and in Food Irradiation and Radioentomology Laboratory (LIARE/CENA/USP). The gamma radiation source that was used is a Co-60 irradiator model Gammabeam-650 of the Atomic Energy of Canada Ltd. whose activity in the beginning of the experiments was 9.8x10 13 Bq. (2,644 Ci). The lots of pupae of Musca domestica had been kept in acclimatized room with 25 ± 2 deg C of temperature and 70 ± 5% of relative humidity, until reaching the desired ages. Lots of pupae of M. domestica that had been used, gotten by the flotation process. They had been irradiated with the ages of 1, 2, 3 and 4 days. The used doses for 1 day pupae was 0 (control) 2.5, 5, 7.5, 10, 12.5, 15, 17.5 20, 22.5, 25, 27.5 and 30 Gy; for 2 days pupae: 0 (control), 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 and 300 Gy; for 3 days pupae: 0 (control), 0, 40, 80, 120, 160, 200, 240, 280, 320 and 360 Gy; and for 4 days pupae: 0 (control), 40; 80; 120; 160, 200, 240, 280, 320, 360, 400 480 and 520 Gy. The dose rate was about 1,500Gy/hr. At these age intervals, the dose to prevent adult emergence was 25, 220, 360 and 520 Gy and the LD50 was 14.28, 128.04, 243.09 e 353.57 Gy, respectively. (author)

  1. LD50 and inviably dose of gamma radiation for Musca domestica L., 1758 (diptera: muscidae) pupae aged 1, 2, 3 and 4 days

    Energy Technology Data Exchange (ETDEWEB)

    Itepan, Natanael M., E-mail: nmitepan@ifsp.edu.br [Instituto Federal de Sao Paulo (IFSP), Piracicaba, SP (Brazil); Itepan, Sara E.D.Z., E-mail: sarazenitepan@ig.com.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia Ciencias e Letras; Arthur, Valter, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    This experiment was carried out in Biological Control of Domestic Fly 'Eduardo Hiroshi Mizumoto' Laboratory at Entomology and Acarology Department (LEA/ESALQ/USP) and in Food Irradiation and Radioentomology Laboratory (LIARE/CENA/USP). The gamma radiation source that was used is a Co-60 irradiator model Gammabeam-650 of the Atomic Energy of Canada Ltd. whose activity in the beginning of the experiments was 9.8x10{sup 13} Bq. (2,644 Ci). The lots of pupae of Musca domestica had been kept in acclimatized room with 25 ± 2 deg C of temperature and 70 ± 5% of relative humidity, until reaching the desired ages. Lots of pupae of M. domestica that had been used, gotten by the flotation process. They had been irradiated with the ages of 1, 2, 3 and 4 days. The used doses for 1 day pupae was 0 (control) 2.5, 5, 7.5, 10, 12.5, 15, 17.5 20, 22.5, 25, 27.5 and 30 Gy; for 2 days pupae: 0 (control), 20, 40, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280 and 300 Gy; for 3 days pupae: 0 (control), 0, 40, 80, 120, 160, 200, 240, 280, 320 and 360 Gy; and for 4 days pupae: 0 (control), 40; 80; 120; 160, 200, 240, 280, 320, 360, 400 480 and 520 Gy. The dose rate was about 1,500Gy/hr. At these age intervals, the dose to prevent adult emergence was 25, 220, 360 and 520 Gy and the LD50 was 14.28, 128.04, 243.09 e 353.57 Gy, respectively. (author)

  2. Induction of dominant lethal mutations by alkylating agnets in germ-cells of the silkworm, Bombyx mori

    International Nuclear Information System (INIS)

    Murota, Tetsuo; Murakami, Akio.

    1977-01-01

    The comparison of the intensity of activity was made by measuring radiation equivalent chemical (REC) dose in the experiment of the induction of dominant lethal mutation, using the germ cells of pupae five days before the moths will be hatched. The alkylating agents employed in the experiment are methyl methanesulfonate (MMS), ethyl methanesulfonate (EMS), diethyl sulfate (DSC) and mitomycine-C (MC). X-ray irradiation was employed in order to indicate the capability of inducing mutation of the alkylating agents with the radiation equivalent chemical dose (REC dose). The dose-hatchability curves for the alkylating agents showed sigmoidal fashion as observed in X-ray, regardless of germ cells. The REC value at LD (50) was estimated by comparing the relative mutagenic capability of these chemicals. In sperm, EMS and DES with concentration of 1.0 x 10 -7 M/g showed the same lethality as about 2.3 kR and 0.6 kR of X-ray. However, no significant reduction of embryonic lethality after the treatment of pupae with MC (up to 2.1 x 10 -7 M/g) and MMS (up to 1.0 x 10 -6 M/g) was observed. As the results, the order of mutagenic effectiveness was as follows: EMS>DES>MMS approximately equal to MC. When oocytes in the mid-pupae were treated with MMS, EMS and MC with concentration of 1.0 x 10 -7 M/g, MMS and EMS showed the same effects as 12.8 kR and 0.6 kR. Surprisingly, MC showed the same lethality as 232.3 kR. This extremely high sensitivity of oocytes to MC may be ascribed to the inhibiting effect of the drug on the meiotic division. (Iwakiri, K.)

  3. LD50 and repellent effects of essential oils from Argentinian wild plant species on Varroa destructor.

    Science.gov (United States)

    Ruffinengo, Sergio; Eguaras, Martin; Floris, Ignazio; Faverin, Claudia; Bailac, Pedro; Ponzi, Marta

    2005-06-01

    The repellent and acaricidal effects of some essential oils from the most typical wild plant species of northern Patagonia, Argentina, on Varroa destructor Anderson & Trueman were evaluated using a complete exposure test. Honey bees, Apis mellifera L., and mites (five specimens of each per dish) were introduced in petri dishes having different oil concentrations (from 0.1 to 25 micro per cage). Survival of bees and mites was registered after 24, 48, and 72 h. An attraction/repellence test was performed using a wax tube impregnated with essential oil and another tube containing wax only. The lowest LD50 values for mites were registered for Acantholippia seriphioides (A. Gray) Mold. (1.27 microl per cage) and Schinus molle L. (2.65 microl per cage) after 24 h, and for Wedelia glauca (Ortega) O. Hoffm. ex Hicken (0.59 microl per cage) and A. seriphioides (1.09 microl per cage) after 72 h of treatment. The oil with the highest selectivity ratio (A. mellifera LD50/V. destructor LD50) was the one extracted from S. molle (>16). Oils of Lippia junelliana (Mold.) Troncoso, Minthostachys mollis (HBK) Grieseb., and Lippia turbinata Grieseb. mixed with wax had repellent properties. None of the oils tested had attractive effects on Varroa mites.

  4. Studies on ’Macaca mulatta’ Infected with Rocky Mountain Spotted Fever

    Science.gov (United States)

    1976-09-10

    Mountain spotted fever (RMSF) rickettsiae. The LD50 in monkeys of the yolk-sac-grown seed stock was 10 to the 1.35th power plaque-forming units. Blood...acid glycoprotein, haptoglobin and albumin) were measured during a study in 16 male rhesus monkeys to determine the median lethal dose (LD50) of Rocky

  5. A critical role of acute bronchoconstriction in the mortality associated with high-dose sarin inhalation: Effects of epinephrine and oxygen therapies

    Energy Technology Data Exchange (ETDEWEB)

    Gundavarapu, Sravanthi; Zhuang, Jianguo; Barrett, Edward G.; Xu, Fadi; Russell, Robert G.; Sopori, Mohan L., E-mail: msopori@lrri.org

    2014-01-15

    Sarin is an organophosphate nerve agent that is among the most lethal chemical toxins known to mankind. Because of its vaporization properties and ease and low cost of production, sarin is the nerve agent with a strong potential for use by terrorists and rouge nations. The primary route of sarin exposure is through inhalation and, depending on the dose, sarin leads to acute respiratory failure and death. The mechanism(s) of sarin-induced respiratory failure is poorly understood. Sarin irreversibly inhibits acetylcholine esterase, leading to excessive synaptic levels of acetylcholine and, we have previously shown that sarin causes marked ventilatory changes including weakened response to hypoxia. We now show that LD{sub 50} sarin inhalation causes severe bronchoconstriction in rats, leading to airway resistance, increased hypoxia-induced factor-1α, and severe lung epithelium injury. Transferring animals into 60% oxygen chambers after sarin exposure improved the survival from about 50% to 75% at 24 h; however, many animals died within hours after removal from the oxygen chambers. On the other hand, if LD{sub 50} sarin-exposed animals were administered the bronchodilator epinephrine, > 90% of the animals survived. Moreover, while both epinephrine and oxygen treatments moderated cardiorespiratory parameters, the proinflammatory cytokine surge, and elevated expression of hypoxia-induced factor-1α, only epinephrine consistently reduced the sarin-induced bronchoconstriction. These data suggest that severe bronchoconstriction is a critical factor in the mortality induced by LD{sub 50} sarin inhalation, and epinephrine may limit the ventilatory, inflammatory, and lethal effects of sarin. - Highlights: • Inhalation exposure of rats to LD{sub 50} sarin causes death through respiratory failure. • Severe bronchoconstriction is the major cause of sarin-induced respiratory failure. • Transfer of sarin exposed rats to 60% oxygen improves the mortality temporarily.

  6. Sterilization and lethal gamma radiation doses on adults and eggs of Sitotroga Cerealella (OLIVIER)

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Bovi, O.A.; Arthur, V.

    1975-04-01

    The influence of lethal doses of radiation from a cobalt 60 gamma source on eggs, adults and fertitility of Sitotroga Cerealella (Olivier) is described. Eggs irradiated with a dose of 14 Krad still showed viability of 16.1%. On longevity doses up to 70 Krad were usually non lethal but some variation could be observed related to the larval diet. Females fertilized by males irradiated with a dose of 70 Krad produced 36% fertile eggs. When the females were irradiated with the same dose, their fertility dropped to 2.2% and when both sexes were irradiated with a 60 Krad dose, the fertility was 28.8%

  7. The lethality test used for estimating the potency of antivenoms against Bothrops asper snake venom: pathophysiological mechanisms, prophylactic analgesia, and a surrogate in vitro assay.

    Science.gov (United States)

    Chacón, Francisco; Oviedo, Andrea; Escalante, Teresa; Solano, Gabriela; Rucavado, Alexandra; Gutiérrez, José María

    2015-01-01

    The potency of antivenoms is assessed by analyzing the neutralization of venom-induced lethality, and is expressed as the Median Effective Dose (ED50). The present study was designed to investigate the pathophysiological mechanisms responsible for lethality induced by the venom of Bothrops asper, in the experimental conditions used for the evaluation of the neutralizing potency of antivenoms. Mice injected with 4 LD50s of venom by the intraperitoneal route died within ∼25 min with drastic alterations in the abdominal organs, characterized by hemorrhage, increment in plasma extravasation, and hemoconcentration, thus leading to hypovolemia and cardiovascular collapse. Snake venom metalloproteinases (SVMPs) play a predominat role in lethality, as judged by partial inhibition by the chelating agent CaNa2EDTA. When venom was mixed with antivenom, there was a venom/antivenom ratio at which hemorrhage was significantly reduced, but mice died at later time intervals with evident hemoconcentration, indicating that other components in addition to SVMPs also contribute to plasma extravasation and lethality. Pretreatment with the analgesic tramadol did not affect the outcome of the neutralization test, thus suggesting that prophylactic (precautionary) analgesia can be introduced in this assay. Neutralization of lethality in mice correlated with neutralization of in vitro coagulant activity in human plasma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Lethal critical body residues as measures of Cd, Pb, and Zn bioavailability and toxicity in the earthworm Eisenia fetida

    Energy Technology Data Exchange (ETDEWEB)

    Conder, J.M.; Lanno, R.P. [Oklahoma State Univ., Dept. of Zoology, Stillwater, OK (United States)

    2003-07-01

    Background. Earthworm heavy metal concentrations (critical body residues, CBRs) may be the most relevant measures of heavy metal bioavailability in soils and may be linkable to toxic effects in order to better assess soil ecotoxicity. However, as earthworms possess physiological mechanisms to secrete and/or sequester absorbed metals as toxicologically inactive forms, total earthworm metal concentrations may not relate well with toxicity. Objective. The objectives of this research were to: i) develop LD{sub 50}s (total earthworm metal concentration associated with 50% mortality) for Cd, Pb, and Zn; ii) evaluate the LD{sub 50} for Zn in a lethal Zn-smelter soil; iii) evaluate the lethal mixture toxicity of Cd, Pb, and Zn using earthworm metal concentrations and the toxic unit (TU) approach; and iv) evaluate total and fractionated earthworm concentrations as indicators of sublethal exposure. Methods. Earthworms (Eisenia fetida (Savigny)) were exposed to artificial soils spiked with Cd, Pb, Zn, and a Cd-Pb-Zn equitoxic mixture to estimate lethal CBRs and mixture toxicity. To evaluate the CBR developed for Zn, earthworms were also exposed to Zn-contaminated field soils receiving three different remediation treatments. Earthworm metal concentrations were measured using a procedure devised to isolate toxicologically active metal burdens via separation into cytosolic and pellet fractions. (orig.)

  9. Insect radiosensitivity: dose curves and dose-fractionation studies of dominant lethal mutations in the mature sperm of 4 insect species

    International Nuclear Information System (INIS)

    LaChance, L.E.; Graham, C.K.

    1984-01-01

    Males of 4 species of insects: Musca domestica L. (housefly) (Diptera), Oncopeltus fasciatus (Dallas) (milkweed bug) (Hemiptera), Anagasta kuhniella (Zeller) (mealmoth) (Lepidoptera) and Heliothis virescens (Fab.) (tobacco budworm) (Lepidoptera) were irradiated as adults. Dose-response curves for the induction of dominant lethal mutations in the mature sperm were constructed. The curves were analyzed mathematically and compared with theoretical computer simulated curves requiring 1, 2, 4, 8 and 16 'hits' for the induction of a dominant lethal mutation. The 4 species belonging to 3 different orders of insects showed a wide range in radiation sensitivity and vastly different dose-response curves. When the data were analyzed by several mathematical models the authors found that a logistic response curve gave reasonably good fit with vastly different parameters for the 4 species. Dose-fractionation experiments showed no reduction in the frequency of lethal mutations induced in any species when an acute dose was fractionated into 2 equal exposures separated by an 8-h period. (Auth.)

  10. Stroop Color-Word Test: A Screening Measure of Selective Attention to Differentiate LD From Non LD Children.

    Science.gov (United States)

    Lazarus, Philip J.; And Others

    1984-01-01

    Used the Stroop Color-Word Test to measure selective attention in learning disabled (N=45) and nonLD (N=50) children. Results indicated that LD children have a significant weakness in the process of selective attention compared to the nonLD children. Findings suggested that the Stroop is an effective screening measure. (JAC)

  11. Dose rate estimates from irradiated light-water-reactor fuel assemblies in air

    International Nuclear Information System (INIS)

    Lloyd, W.R.; Sheaffer, M.K.; Sutcliffe, W.G.

    1994-01-01

    It is generally considered that irradiated spent fuel is so radioactive (self-protecting) that it can only be moved and processed with specialized equipment and facilities. However, a small, possibly subnational, group acting in secret with no concern for the environment (other than the reduction of signatures) and willing to incur substantial but not lethal radiation doses, could obtain plutonium by stealing and processing irradiated spent fuel that has cooled for several years. In this paper, we estimate the dose rate at various distances and directions from typical pressurized-water reactor (PWR) and boiling-water reactor (BWR) spent-fuel assemblies as a function of cooling time. Our results show that the dose rate is reduced rapidly for the first ten years after exposure in the reactor, and that it is reduced by a factor of ∼10 (from the one year dose rate) after 15 years. Even for fuel that has cooled for 15 years, a lethal dose (LD50) of 450 rem would be received at 1 m from the center of the fuel assembly after several minutes. However, moving from 1 to 5 m reduces the dose rate by over a factor of 10, and moving from 1 to 10 m reduces the dose rate by about a factor of 50. The dose rates 1 m from the top or bottom of the assembly are considerably less (about 10 and 22%, respectively) than 1 m from the center of the assembly, which is the direction of the maximum dose rate

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

    Science.gov (United States)

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

    2012-03-01

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

  13. Comparison of waterborne and intraperitoneal exposure to fipronil in the Caspian white fish (Rutilus frisii) on acute toxicity and histopathology

    OpenAIRE

    Ardeshir, Rashid Alijani; Zolgharnein, Hossein; Movahedinia, Abdolali; Salamat, Negin; Zabihi, Ebrahim

    2017-01-01

    Fipronil is an effective insecticide widely used in agriculture with potential ecotoxicological consequences. The median lethal dose (LD50) and concentration (LC50) of fipronil in 16.3 g Caspian white fish, Rutilus frisii kutum fingerlings were determined. To determine the LD50, a total of 133 fish were assigned to 19 tanks (7 fish/tank) including one control and 6 treatment groups (300, 450, 550, 650, 750, 850 mg/kg). Fish were injected intraperitoneally and monitored at 96 h. The LD50 of...

  14. Variability of LD50 Values from Rat Oral Acute Toxicity Studies: Implications for Alternative Model Development

    Science.gov (United States)

    Alternative models developed for estimating acute systemic toxicity are generally evaluated using in vivo LD50 values. However, in vivo acute systemic toxicity studies can produce variable results, even when conducted according to accepted test guidelines. This variability can ma...

  15. Low doses effects of ionizing radiation on Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Durand, J.; Broock, M. van; Gillette, V.H.

    2000-01-01

    The exposure of living cells to low doses of ionizing radiation induce in response the activation of cellular protection mechanisms against subsequent larger doses of radiation. This cellular adaptive response may vary depending on radiation intensity and time of exposure, and also on the testing probes used whether they were mammalian cells, yeast, bacteria and other organisms or cell types. The mechanisms involved are the genome activation, followed by DNA repair enzymes synthesis. Due to the prompt cell response, the cell cycle can be delayed, and the secondary detoxification of free radicals and/or activation of membrane bound receptors may proceed. All these phenomena are submitted to intense scientific research nowadays, and their elucidation will depend on the complexity of the organism under study. In the present work, the effects of low doses of ionizing radiation (gamma rays) over a suspension of the yeast Saccharomyces cerevisiae (Baker's yeast) was studied, mainly in respect to survival rate and radio-adaptive response. At first, the yeast surviving curve was assessed towards increasing doses, and an estimation of Lethal Dose 50 (LD50) was made. The irradiation tests were performed at LINAC (electrons Linear Accelerator) where electron energy reached approximately 2.65 MeV, and gamma-radiation was produced for bremsstrahlung process over an aluminium screen target. A series of experiments of conditioning doses was performed and an increment surviving fraction was observed when the dose was 2.3 Gy and a interval time between this and a higher dose (challenging dose) of 27 Gy was 90 minutes. A value of 58 ± 4 Gy was estimated for LD50, at a dose rate of 0.44 ± 0.03 Gy/min These quantities must be optimized. Besides data obtained over yeast survival, an unusual increasing amount of tiny yeast colonies appeared on the agar plates after incubation, and this number increased as increasing the time exposure. Preliminary results indicate these colonies as

  16. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species

    Directory of Open Access Journals (Sweden)

    Laura M. Addy-Orduna

    2011-01-01

    Full Text Available It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp., shiny cowbirds (Molothrus bonariensis, and eared doves (Zenaida auriculata. Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD50 and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be substantially more sensitive to formulated beta-cyfluthrin (LD50=(170±41 mg/kg than the other two species tested (LD50=(2234±544 mg/kg and LD50=(2271±433 mg/kg, resp.. The LD50 obtained for canaries was also considerably lower than typical toxicity values available in the literature for pyrethroids. This study emphasizes the need for testing a broader range of species with potentially toxic insecticides, using modern up and down test designs with minimal numbers of birds.

  17. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species.

    Science.gov (United States)

    Addy-Orduna, Laura M; Zaccagnini, María-Elena; Canavelli, Sonia B; Mineau, Pierre

    2011-01-01

    It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp.), shiny cowbirds (Molothrus bonariensis), and eared doves (Zenaida auriculata). Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD(50)) and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be substantially more sensitive to formulated beta-cyfluthrin (LD(50) = (170 ± 41) mg/kg) than the other two species tested (LD(50) = (2234 ± 544) mg/kg and LD(50) = (2271 ± 433) mg/kg, resp.). The LD(50) obtained for canaries was also considerably lower than typical toxicity values available in the literature for pyrethroids. This study emphasizes the need for testing a broader range of species with potentially toxic insecticides, using modern up and down test designs with minimal numbers of birds.

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

    International Nuclear Information System (INIS)

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

    1988-01-01

    Early and late murine tissue responses to single or fractionated low doses of heavy charged particles, fission-spectrum neutrons or gamma rays are considered. Damage to the hematopoietic system is emphasized, but results on acute lethality, host response to challenge with transplanted leukemia cells and life-shortening are presented. Low dose rates per fraction were used in some neutron experiments. Split-dose lethality studies (LD 50/30) with fission neutrons indicated greater accumulation of injury during a 9 fraction course (over 17 days) than was the case for γ-radiation. When total doses of 96 or 247 cGy of neutrons or γ rays were given as a single dose or in 9 fractions, a significant sparing effect on femur CFU-S depression was observed for both radiation qualities during the first 11 days, but there was not an earlier return to normal with dose fractionation. During the 9 fraction sequence, a significant sparing effect of low dose rate on CFU-S depression was observed in both neutron and γ-irradiated mice. CFU-S content at the end of the fractionation sequence did not correlate with measured LD 50/30. Sustained depression of femur and spleen CFU-S and a significant thrombocytopenia were observed when a total neutron dose of 240 cGy was given in 72 fractions over 24 weeks at low dose rates. The temporal aspects of CFU-S repopulation were different after a single versus fractionated neutron doses. The sustained reduction in the size of the CFU-S population was accompanied by an increase in the fraction in DNA synthesis. The proliferation characteristics and effects of age were different for radial CFU-S population closely associated with bone, compared with the axial population that can be readily aspirated from the femur. In aged irradiated animals, the CFU-S proliferation/redistribution response to typhoid vaccine showed both an age and radiation effect. 63 refs., 6 figs., 7 tabs

  19. Tityus serrulatus Scorpion Venom: In Vitro Tests and Their Correlation with In Vivo Lethal Dose Assay

    Directory of Open Access Journals (Sweden)

    Daniela Cajado-Carvalho

    2017-11-01

    Full Text Available Scorpion stings are the main cause of human envenomation in Brazil and, for the treatment of victims, the World Health Organization (WHO recommends the use of antivenoms. The first step to achieve effective antivenom is to use a good quality venom pool and to evaluate it, with LD50 determination as the most accepted procedure. It is, however, time-consuming and requires advanced technical training. Further, there are significant ethical concerns regarding the number of animals required for testing. Hence, we investigated the correspondence between LD50 results, in vitro assays, and a strong correlation with proteolytic activity levels was observed, showing, remarkably, that proteases are potential toxicity markers for Tityus serrulatus venom. The comparison of reversed-phase chromatographic profiles also has a potential application in venoms’ quality control, as there were fewer neurotoxins detected in the venom with high LD50 value. These results were confirmed by mass spectrometry analysis. Therefore, these methods could precede the LD50 assay to evaluate the venom excellence by discriminating—and discarding—poor-quality batches, and, consequently, with a positive impact on the number of animals used. Notably, proposed assays are fast and inexpensive, being technically and economically feasible in Tityus serrulatus venom quality control to produce effective antivenoms.

  20. Induction and evaluation of useful mutants in cassava (Manihot esculenta) and yam (Diascorea sp.) by gamma radiation

    International Nuclear Information System (INIS)

    Klu, G.Y.P.

    1987-11-01

    Stem cuttings of the cassava cultivar ''Bosom'' were irradiated with gamma rays. A dose of 5000 rad was lethal, but a dose of 3000 rad was found to allow sprouting of 50% of the buds. For tuber cuttings of yam, the LD50 was found to be around 2000 rad. 6 refs, 1 tab

  1. Insoluble glycogen, a metabolizable internal adsorbent, decreases the lethality of endotoxin shock in rats

    Directory of Open Access Journals (Sweden)

    S. Sipka

    1997-01-01

    Full Text Available Insoluble glycogen is an enzymatically modified form of naturally occurring soluble glycogen with a great adsorbing capacity. It can be metabolized by phagocytes to glucose. In this study we used insoluble glycogen intravenously in the experimental endotoxin shock of rats. Wistar male rats were sensitized to endotoxin by Pb acetate. The survival of rats were compared in groups of animals endotoxin shock treated and non-treated with insoluble glycogen. Furthermore, we have determined in vitro the binding capacity of insoluble glycogen for endotoxin, tumour necrosis factor alpha, interleukin-1 and secretable phospholipase A2. Use of 10 mg/kg dose of insoluble glycogen could completely prevent the lethality of shock induced by LD50 quantity of endotoxin in rats. All animals treated survived. Insoluble glycogen is a form of ‘metabolizable internal adsorbents’. It can potentially be used for treatment of septic shock.

  2. Effects of pentachlorophenol on survival of earthworms (Lumbricus terrestris) and phagocytosis by their immunoactive coelomocytes

    Energy Technology Data Exchange (ETDEWEB)

    Giggleman, M.A.; Fitzpatrick, L.C.; Goven, A.J. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Denton, TX (United States)

    1998-12-01

    Earthworms, Lumbricus terrestris, exposed for 96 h to filter paper saturated with five nominal concentrations of pentachlorophenol, exhibited a 50% lethal concentration (LC50) of 25.0 {micro}g PCP/cm{sup 2} and corresponding whole worm body burden-based 50% lethal dose (LD50) of 877.7 {micro}g PCP/g dry mass. Linear regression modeling showed that worms increased body concentrations (BC = {micro}g PCP/g dry tissue mass) with increasing exposure concentrations (EC) according to BC = 113.5 + 29.5EC. Phagocytosis of yeast cells by immunoactive coelomocytes was suppressed only at body concentrations (863.3 {micro}g PCP/g dry mass) that approximated the calculated LD50 and overlapped those demonstrating lethality, indicating a sharp transition between sublethal and lethal toxicity. An exposure concentration of 15 {micro}g PCP/cm{sup 2} produced significant suppression of phagocytosis of yeast cells by immunoactive coelomocytes. However, the average measured body burden from this group approximated the estimated LD50, indicating a sharp toxic response slope. Exposure to 10 {micro}g PCP/cm{sup 2} with a corresponding body concentration of 501.3 {micro}g PCP/g dry mass did not affect phagocytosis. The importance of body burden data is emphasized.

  3. Comparative influence of dose rate and radiation nature, on lethality after big mammals irradiation

    International Nuclear Information System (INIS)

    Destombe, C.; Le Fleche, Ph.; Grasseau, A.; Reynal, A.

    1997-01-01

    For the same dose and the 30 days lethality as biological criterion, the dose rate influence is more important than the radiation nature on the results of an big mammals total body irradiation. (authors)

  4. In vivo toxic and lethal cardiovascular effects of a synthetic polymeric 1,3-dodecylpyridinium salt in rodents

    International Nuclear Information System (INIS)

    Grandic, Marjana; Sepcic, Kristina; Turk, Tom; Juntes, Polona; Frangez, Robert

    2011-01-01

    APS12-2 is one in a series of synthetic analogs of the polymeric alkylpyridinium salts isolated from the marine sponge Reniera sarai. As it is a potential candidate for treating non small cell lung cancer (NSCLC), we have studied its possible toxic and lethal effects in vivo. The median lethal dose (LD 50 ) of APS12-2 in mice was determined to be 11.5 mg/kg. Electrocardiograms, arterial blood pressure and respiratory activity were recorded under general anesthesia in untreated, pharmacologically vagotomized and artificially ventilated rats injected with APS12-2. In one group, the in vivo effects of APS12-2 were studied on nerve-evoked muscle contraction. Administration of APS12-2 at a dose of 8 mg/kg caused a progressive reduction of arterial blood pressure to a mid-circulatory value, accompanied by bradycardia, myocardial ischemia, ventricular extrasystoles, and second degree atrio-ventricular block. Similar electrocardiogram and arterial blood pressure changes caused by APS12-2 (8 mg/kg) were observed in animals pretreated with atropine and in artificially ventilated animals, indicating that hypoxia and cholinergic effects do not play a crucial role in the toxicity of APS12-2. Application of APS12-2 at sublethal doses (4 and 5.5 mg/kg) caused a decrease of arterial blood pressure, followed by an increase slightly above control values. We found that APS12-2 causes lysis of rat erythrocytes in vitro, therefore it is reasonable to expect the same effect in vivo. Indeed, hyperkalemia was observed in the blood of experimental animals. Hyperkalemia probably plays an important role in APS12-2 cardiotoxicity since no evident changes in histopathology of the heart were found. However, acute lesions were observed in the pulmonary vessels of rats after application of 8 mg/kg APS12-2. Predominant effects were dilation of interalveolar blood vessels and lysis of aggregated erythrocytes within their lumina. - Highlights: → LD 50 estimated in mice (11.5 mg/kg) revealed that

  5. Improving reptile ecological risk assessment: oral and dermal toxicity of pesticides to a common lizard species (Sceloporus occidentalis).

    Science.gov (United States)

    Weir, Scott M; Yu, Shuangying; Talent, Larry G; Maul, Jonathan D; Anderson, Todd A; Salice, Christopher J

    2015-08-01

    Reptiles have been understudied in ecotoxicology, which limits consideration in ecological risk assessments. The goals of the present study were 3-fold: to improve oral and dermal dosing methodologies for reptiles, to generate reptile toxicity data for pesticides, and to correlate reptile and avian toxicity. The authors first assessed the toxicity of different dosing vehicles: 100 μL of water, propylene glycol, and acetone were not toxic. The authors then assessed the oral and dermal toxicity of 4 pesticides following the up-and-down procedure. Neither brodifacoum nor chlorothalonil caused mortality at doses ≤ 1750 μg/g. Under the "neat pesticide" oral exposure, endosulfan (median lethal dose [LD50] = 9.8 μg/g) was more toxic than λ-cyhalothrin (LD50 = 916.5 μg/g). Neither chemical was toxic via dermal exposure. An acetone dosing vehicle increased λ-cyhalothrin toxicity (oral LD50 = 9.8 μg/g; dermal LD50 = 17.5 μg/g), but not endosulfan. Finally, changes in dosing method and husbandry significantly increased dermal λ-cyhalothrin LD50s, which highlights the importance of standardized methods. The authors combined data from the present study with other reptile LD50s to correlate with available avian data. When only definitive LD50s were used in the analysis, a strong correlation was found between avian and reptile toxicity. The results suggest it is possible to build predictive relationships between avian and reptile LD50s. More research is needed, however, to understand trends associated with chemical classes and modes of action. © 2015 SETAC.

  6. Biological Effects of Ionizing Radiation; Efectos Biologicos de la Radiacion Ionizante

    Energy Technology Data Exchange (ETDEWEB)

    Durand, J L [Instituto Balseiro, Universidad Nacional de Cuyo, Centro Atomico Bariloche (Argentina)

    2000-07-01

    The aim of this work is to verify the existence of the adaptive response phenomenon induced by low doses of ionizing radiation in living cells.A wild-type yeast Saccharomyces cerevisiae (Baker's yeast) was chosen as the biological target.As a parameter to quantify the sensibility of the target to radiation, the Lethal Dose 50 (LD50 ) was observed. In our experimental condition a value of (60 {+-} 1) Gy was measured for LD50 with Dose Rate of (0.44 {+-} 0.03) Gy/min. The method employed to show up the adaptive response phenomenon consisted in exposing the sample to low ''conditioning'' doses, which would initiate these mechanisms. Later the samples with and without conditioning were exposed to higher ''challenging'' doses (such as LD50), and the surviving fractions were compared. In order to maximize the differences, the doses and the time between irradiations were varied. The best results were obtained with both a conditioning dose of (0.44 {+-} 0.03) Gy and a waiting time of 2 hs until the application of the challenging dose. Following this procedures the 80% of the conditioned samples has survived, after receiving the application of the LD50. The adaptive response phenomenon was also verified for a wide range of challenging doses.

  7. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Durand, J.L.

    2000-01-01

    The aim of this work is to verify the existence of the adaptive response phenomenon induced by low doses of ionizing radiation in living cells.A wild-type yeast Saccharomyces cerevisiae (Baker's yeast) was chosen as the biological target.As a parameter to quantify the sensibility of the target to radiation, the Lethal Dose 50 (LD50 ) was observed. In our experimental condition a value of (60 ± 1) Gy was measured for LD50 with Dose Rate of (0.44 ± 0.03) Gy/min. The method employed to show up the adaptive response phenomenon consisted in exposing the sample to low ''conditioning'' doses, which would initiate these mechanisms. Later the samples with and without conditioning were exposed to higher ''challenging'' doses (such as LD50), and the surviving fractions were compared. In order to maximize the differences, the doses and the time between irradiations were varied. The best results were obtained with both a conditioning dose of (0.44 ± 0.03) Gy and a waiting time of 2 hs until the application of the challenging dose. Following this procedures the 80% of the conditioned samples has survived, after receiving the application of the LD50. The adaptive response phenomenon was also verified for a wide range of challenging doses

  8. Effect of radiation dose rate and cyclophosphamide on pulmonary toxicity after total body irradiation in a mouse model

    International Nuclear Information System (INIS)

    Safwat, Akmal; Nielsen, Ole S.; El-Badawy, Samy; Overgaard, Jens

    1996-01-01

    Purpose: Interstitial pneumonitis (IP) is still a major complication after total body irradiation (TBI) and bone marrow transplantation (BMT). It is difficult to determine the exact role of radiation in this multifactorial complication, especially because most of the experimental work on lung damage was done using localized lung irradiation and not TBI. We have thus tested the effect of radiation dose rate and combining cyclophosphamide (CTX) with single fraction TBI on lung damage in a mouse model for BMT. Methods and Materials: TBI was given as a single fraction at a high dose rate (HDR, 0.71 Gy/min) or a low dose rate (LDR, 0.08 Gy/min). CTX (250 mg/kg) was given 24 h before TBI. Bone marrow transplantation (BMT) was performed 4-6 h after the last treatment. Lung damage was assessed using ventilation rate (VR) and lethality between 28 and 180 days (LD (50(28))-180 ). Results: The LD 50 for lung damage, ± standard error (SE), increased from 12.0 (± 0.2) Gy using single fraction HDR to 15.8 (± 0.6) Gy using LDR. Adding CTX shifted the dose-response curves towards lower doses. The LD 50 values for the combined treatment were 5.3 (± 0.2) and 3.5 (± 0.2) Gy for HDR and LDR, respectively. This indicates that the combined effect of CTX and LDR was more toxic than that of combined CTX and HDR. Lung damage evaluated by VR demonstrated two waves of VR increase. The first wave of VR increase occurred after 6 weeks using TBI only and after 3 weeks in the combined CTX-TBI treatment, irrespective of total dose or dose rate. The second wave of VR elevation resembled the IP that follows localized thoracic irradiation in its time of occurrence. Conclusions: Lung damage following TBI could be spared using LDR. However, CTX markedly enhances TBI-induced lung damage. The combination of CTX and LDR is more toxic to the lungs than combining CTX and HDR

  9. Low dose CT perfusion in acute ischemic stroke.

    Science.gov (United States)

    Murphy, Amanda; So, Aaron; Lee, Ting-Yim; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I

    2014-12-01

    The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54% male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p test post hoc analysis (p 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements.

  10. Acute oral toxicity test of chemical compounds in silkworms.

    Science.gov (United States)

    Usui, Kimihito; Nishida, Satoshi; Sugita, Takuya; Ueki, Takuro; Matsumoto, Yasuhiko; Okumura, Hidenobu; Sekimizu, Kazuhisa

    2016-02-01

    This study performed an acute oral toxicity test of 59 compounds in silkworms. These compounds are listed in OECD guidelines as standard substances for a cytotoxicity test, and median lethal dose (LD(50)) werecalculated for each compound. Acute oral LD(50) values in mammals are listed in OECD guidelines and acute oral LD(50) values in silkworms were determined in this study. R(2) for the correlation between LD(50) values in mammals and LD(50) values in silkworms was 0.66. In addition, the acute oral toxicity test in silkworms was performed by two different facilities, and test results from the facilities were highly reproducible. These findings suggest that an acute oral toxicity test in silkworms is a useful way to evaluate the toxicity of compounds in mammals.

  11. LD-cladding-pumped 50 pm linewidth Tm 3+ -doped silica fiber laser.

    Science.gov (United States)

    Yunjun, Zhang; Baoquan, Yao; Youlun, Ju; Hui, Zhou; Yuezhu, Wang

    2008-05-26

    We report on a Tm(3+)-doped fiber laser source operating at 1936.4 nm with a very narrow linewidth (50 pm) laser output. Up to 2.4 W cw laser power was obtained from an 82 cm long Tm(3+)-doped multimode-core fiber cladding pumped by a 792 nm laser diode (LD). The fiber laser cavity included a high-reflective dichroic and a low-reflective FBG output coupler. The multimode fiber Bragg grating (FBG) transmission spectrum and output laser spectrum were measured. By adjusting the distance between the dichroic and the Tm(3+)-doped fiber end, the multipeak laser spectrum changed to a single-peak laser spectrum.

  12. Synergistic potential of dillapiole-rich essential oil with synthetic pyrethroid insecticides against fall armyworm

    OpenAIRE

    Fazolin, Murilo; Estrela, Joelma Lima Vidal; Medeiros, André Fábio Monteiro; Silva, Iriana Maria da; Gomes, Luiara Paiva; Silva, Maria Samylla de Farias

    2016-01-01

    ABSTRACT: The objective of this study was to evaluate the synergy and response homogeneity of the Spodoptera frugiperda larvae population to the Piper aduncum essential oil in combination with pyrethroid insecticides (alpha-cypermethrin, beta-cypermethrin, fenpropathrin, and gamma-cyhalothrin) compared to piperonylbutoxide (PBO) as positive control. Synergism (SF) comparisons were obtained using lethal concentration (LC50) and lethal dose (LD50) ratios of insecticides individually and in thei...

  13. Antihypertensive Activity of Aqueous-Methanol Extract of Berberis ...

    African Journals Online (AJOL)

    HP

    Median lethal dose (LD50) and sub-chronic toxicity of the extract were also determined ... possible mode(s) of action, side effects, toxicity ... medicinal uses. Berberis ... evaluate the possible antihypertensive effect of this plant. EXPERIMENTAL.

  14. Low dose CT perfusion in acute ischemic stroke

    International Nuclear Information System (INIS)

    Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I.; So, Aaron; Lee, Ting-Yim

    2014-01-01

    The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

  15. Efficacy of the Tertiary Oxime Monoisonitrosoacetone (MINA) Against Lethal Sarin Intoxication in the Guinea Pig

    Science.gov (United States)

    2007-10-01

    Sarin 5a. CONTRACT NUMBER Intoxication in the Guinea Pig 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Koplovitz, I and...efficacy of MINA as a treatment for lethal sarin (GB) intoxication in guinea pigs . Male animals were challenged subcutaneously (s.c.) with 2 LD50s...oximes that are readily able to enter the brain. 15. SUBJECT TERMS oximes, brain, sarin, reactivation, nerve agents, guinea pigs 16. SECURITY

  16. Cytopathogenic effects in enterocytelike Caco-2 cells differentiate virulent from avirulent Listeria strains.

    OpenAIRE

    Pine, L; Kathariou, S; Quinn, F; George, V; Wenger, J D; Weaver, R E

    1991-01-01

    We have developed a simple test that differentiates between virulent and avirulent Listeria species as defined by the mouse 50% lethal doses (LD50S). The assay is based on trypan blue-revealed cytopathogenic effects that are produced during the infection of the human enterocytelike cell line Caco-2. These effects were elicited only by Listeria strains that had an intraperitoneal mouse LD50 less than 10(8) and were not produced by nonhemolytic, avirulent strains of Listeria monocytogenes gener...

  17. NATO Planning Guide for the Estimation of CBRN Casualties

    Science.gov (United States)

    2014-11-01

    of icon movement, changes in breathing rate (e.g. due to sprinting to cover), and changing defensive postures (e.g. due to warning and response...4 300 0 1 2 4 400 0 0 1 4 700 0 0 0 4 * According to the default value for Tdeath-CN-SL4, death would be modeled at this point. Table 4-46...SD.2 KIA Killed in action kg Kilogram kJ/m2 Kilojoule per square meter kPa Kilopascal LD50 Median lethal dose; dose resulting in lethality for 50

  18. Derangement of cellular plasma membranes due to non-lethal radiation doses

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Kubasova, T.; Somosy, Z.; Horvath, L.

    1983-01-01

    Earlier observations in the laboratory on fibroblasts and various blood cells of animal and human origins pointed to alteration of concanavalin A binding sites of plasma membranes as well as to concomitant morphological changes and scanning electron microscopic appearance of cell surfaces following sub-lethal doses of X-, fission neutron and beta irradiations. The effects appeared early and existed temporarily; their intensities and the restitution of membrane function depended on radiation doses, types and conditions of cells. In the present paper further aspects of structural and functional derangements of plasma membranes are introduced which were provoked by X- and tritium beta irradiation in the dose range up to 2.5 Gy and in the concentration range from 3.7 kBq/mL, respectively. The state of membrane structure was followed by bindings of various ligands of different receptor requirements, concanavalin A, cationized ferritin and polio virus. In the case of X-irradiation the binding conditions suggest the shift of overall negative surface charges to less negative ones. It was also found that radiation-induced phenomena appear on the cell surface unevenly. Long- and short-term treatments of cells with 3 H-thymidine and 3 H-water also perturb the plasma membrane; beta irradiation affects it directly. Membrane structure and function are suggested to offer good biological models to study correlation of energy deposition and biological effects, both restricted to domains of nanometre range. The data give evidence for radiation-induced membrane alterations in the sub-lethal or non-lethal ranges which might have consequences in the development of stochastic and non-stochastic effects. (author)

  19. Low dose CT perfusion in acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Amanda; Symons, Sean; Jakubovic, Raphael; Zhang, Liying; Aviv, Richard I. [Sunnybrook Health Sciences Centre, Toronto, ON (Canada); So, Aaron; Lee, Ting-Yim [Robarts Research Institute, London, Ontario (Canada)

    2014-12-15

    The purpose of this investigation is to determine if CT perfusion (CTP) measurements at low doses (LD = 20 or 50 mAs) are similar to those obtained at regular doses (RD = 100 mAs), with and without the addition of adaptive statistical iterative reconstruction (ASIR). A single-center, prospective study was performed in patients with acute ischemic stroke (n = 37; 54 % male; age = 74 ± 15 years). Two CTP scans were performed on each subject: one at 100 mAs (RD) and one at either 50 or 20 mAs (LD). CTP parameters were compared between the RD and LD scans in regions of ischemia, infarction, and normal tissue. Differences were determined using a within-subjects ANOVA (p < 0.05) followed by a paired t test post hoc analysis (p < 0.01). At 50 mAs, there was no significant difference between cerebral blood flow (CBF), cerebral blood volume (CBV), or time to maximum enhancement (Tmax) values for the RD and LD scans in the ischemic, infarcted, or normal contralateral regions (p < 0.05). At 20 mAs, there were significant differences between the RD and LD scans for all parameters in the ischemic and normal tissue regions (p > 0.05). CTP-derived CBF and CBV are not different at 50 mAs compared to 100 mAs, even without the addition of ASIR. Current CTP protocols can be modified to reduce the effective dose by 50 % without altering CTP measurements. (orig.)

  20. Animal mortality resulting from uniform exposures to photon radiations: Calculated LD50s and a compilation of experimental data

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Wells, S.M.; Young, R.W.

    1986-12-01

    Studies conducted during the 1950s and 1960s of radiation-induced mortality to diverse animal species under various exposure protocols were compiled into a mortality data base. Some 24 variables were extracted and recomputed from each of the published studies, which were collected from a variety of available sources, primarily journal articles. Two features of this compilation effort are (1) an attempt to give an estimate of the uniform dose received by the bone marrow in each treatment so that interspecies differences due to body size were minimized and (2) a recomputation of the LD 50 where sufficient experimental data are available. Exposure rates varied in magnitude from about 10 -2 to 10 3 R/min. This report describes the data base, the sources of data, and the data-handling techniques; presents a bibliography of studies compiled; and tabulates data from each study. 103 refs., 44 tabs

  1. Blue light induced reactive oxygen species from flavin mononucleotide and flavin adenine dinucleotide on lethality of HeLa cells.

    Science.gov (United States)

    Yang, Ming-Yeh; Chang, Chih-Jui; Chen, Liang-Yü

    2017-08-01

    Photodynamic therapy (PDT) is a safe and non-invasive treatment for cancers and microbial infections. Various photosensitizers and light sources have been developed for clinical cancer therapies. Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) are the cofactor of enzymes and are used as photosensitizers in this study. Targeting hypoxia and light-triggering reactive oxygen species (ROS) are experimental strategies for poisoning tumor cells in vitro. HeLa cells are committed to apoptosis when treated with FMN or FAD and exposed to visible blue light (the maximum emitted wavelength of blue light is 462nm). Under blue light irradiation at 3.744J/cm 2 (=0.52mW/cm 2 irradiated for 2h), the minimal lethal dose is 3.125μM and the median lethal doses (LD 50 ) for FMN and FAD are 6.5μM and 7.2μM, respectively. Individual exposure to visible blue light irradiation or riboflavin photosensitizers does not produce cytotoxicity and no side effects are observed in this study. The western blotting results also show that an intrinsic apoptosis pathway is activated by the ROS during photolysis of riboflavin analogues. Blue light triggers the cytotoxicity of riboflavins on HeLa cells in vitro. Based on these results, this is a feasible and efficient of PDT with an intrinsic photosensitizer for cancer research. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Radiation lethality in the opossum

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, N.; Bushong, S.C.; North, L.B.; Thornby, J.

    1976-12-01

    Groups of male opossum (Didelphis virginiana) at 6 months of age were exposed to 350, 500, 550, 600, 650, 700, and 750 rad of whole-body /sup 60/Co radiation at a midline dose rate of 125 rad/min. The 30-day LD/sub 50/ was 511 rad with 95% confidence limits of 454 to 576 rad. The overall mean survival time was 17.9 days and the highest incidence of death occurred on the 16th day.

  3. Radiation lethality in the opossum

    International Nuclear Information System (INIS)

    Prasad, N.; Bushong, S.C.; North, L.B.; Thornby, J.

    1976-01-01

    Groups of male opossum (Didelphis virginiana) at 6 months of age were exposed to 350, 500, 550, 600, 650, 700, and 750 rad of whole-body 60 Co radiation at a midline dose rate of 125 rad/min. The 30-day LD 50 was 511 rad with 95% confidence limits of 454 to 576 rad. The overall mean survival time was 17.9 days and the highest incidence of death occurred on the 16th day

  4. Analgesic and anti-inflammatory activities of the n-butanol fraction of ...

    African Journals Online (AJOL)

    BF) using standard procedures. The median lethal dose (LD50) of the fraction was determined using Lorke's method and the analgesic effect was evaluated using acetic acid-induced writhing test in mice, while the anti-inflammatory activity was ...

  5. Standardization of anti-lethal toxin potency test of antivenoms prepared from two different Agkistrodon halys venoms

    Directory of Open Access Journals (Sweden)

    K. H. Lee

    2006-01-01

    Full Text Available In Korea, antivenoms for the treatment of patients bitten by venomous snakes have been imported from Japan or China. Although there is cross-reactivity between these antibodies and venoms from snakes indigenous to Korea (e.g. Agkistrodon genus, protection is not optimal. Antivenoms specifically prepared to neutralize Korean snake venoms could be more effective, with fewer side effects. To this end, we established an infrastructure to develop national standards and created a standardized method to evaluate the efficacy of two horse-derived antivenoms using mouse lethal toxin test. Additionally, we determined the antivenoms neutralizing activity against lethal doses (LD50 of Agkistrodon halys (from Japan and Jiangzhe Agkistrodon halys (from China venoms. We also performed cross-neutralization tests using probit analysis on each pairing of venom and antivenom in order to check the possibility of using Jiangzhe A. halys venom as a substitute for A. halys venom, the current standard. Slope of A. halys venom with A. halys antivenom was 10.2 and that of A. halys venom with Jiangzhe A. halys antivenom was 9.6. However, Slope of Jiangzhe A. halys venom with A. halys antivenom was 4.7 while that of Jiangzhe A. halys venom with Jiangzhe A. halys antivenom was 11.5. Therefore, the significant difference in slope patterns suggests that Jiangzhe A. halys venom cannot be used as a substitute for the standard venom to test the anti-lethal toxin activity of antivenoms (p<0.05.

  6. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    International Nuclear Information System (INIS)

    Shamma, M.; Al-Adawi, M.; Sharabi, N.

    2002-11-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays. (author)

  7. Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

    CERN Document Server

    Shamma, M A; Sharabi, N

    2002-01-01

    The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays.

  8. Gamma-ray mutagenic effect on adzuki bean and the optimum dose

    International Nuclear Information System (INIS)

    Shen Huifang; Li Guozhu

    2012-01-01

    Dry seeds of three kinds of adzuki beans (Jinhong1, Jihong9218, and Jingnong6) were irradiated by 60 Co γ-rays to 100, 200, 300, 400, 500 and 600 Gy. The radiation effects on seedlings were analyzed to estimate the optimum dose, which was 400 to 600 Gy, based on the average half lethal dose (LD 50 ) of 473.3 Gy for the three kinds of adzuki beans. The M 1 γ-ray mutagenic effects were studied by farming the three kinds of adzuki beans irradiated to 350, 500 and 650 Gy. It was found that the beans treated with higher doses had obvious inhibition on germination rate, seedling development, with significant or very significant difference compared with the CK. There was significantly negative correlation between seedling emergences, seedling height and doses. Irradiation affected mature plants by reducing plant height, decreasing nodes number of main stem, pods number per plant, seeds per pod and shortening pod length with significant. The order of radio-sensitivity to γ-rays was as follows: Jinhong1, Jihong9218, and Jingnong6. (authors)

  9. A preliminary safety evaluation of polyhexamethylene guanidine hydrochloride.

    Science.gov (United States)

    Asiedu-Gyekye, Isaac Julius; Mahmood, Seidu Abdulai; Awortwe, Charles; Nyarko, Alexander Kwadwo

    2014-01-01

    Polyhexamethylene guanidine hydrochloride (PHMGH) is used worldwide as an antimicrobial agent with broad spectra of activity and also for treating pool water. This non-GLP preliminary study aims at investigating in a subchronic toxicity study possible effects at supra-optimal doses of this biocide. Both acute and subchronic toxicity studies were conducted. LD(50) for PHMGH was estimated to be 600 mg/kg (ie LC(50) 2 ml of 7.5% solution) when administered as a single dose by gavage via a stomach tube in accordance with the expected route of administration. The acute studies showed that the median lethal dose (LD(50)) of 600 mg/kg was accompanied by signs of neurotoxicity. Haematological and biochemical parameters of subchronic toxicity studies were non-significant. Subchronic doses of 0.006 mg/kg, 0.012 mg/kg and 0.036 mg/kg were administered. 20% of the animals at a dose of 0.006 mg/kg and 0.036 mg/kg showed mild degrees of hydropic changes in proximal tubules while 10% of animals at all the doses had their liver tissues showing local areas of mild pericentral hepatocytes degeneration. PHMGH did not produce any major organ defect with regard to the kidney, heart, and liver. The LD(50) was much higher than the recommended dosage by a factor of about 50,000. The recommended residual concentration is far less than the median lethal dose using rats as test subjects. These results could serve as a basis for investigating the full toxicological profile if it is to be used for the treatment of raw water to make it potable. © The Author(s) 2014.

  10. Animal mortality resulting from uniform exposures to photon radiations: Calculated LD/sub 50/s and a compilation of experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.D.; Morris, M.D.; Wells, S.M.; Young, R.W.

    1986-12-01

    Studies conducted during the 1950s and 1960s of radiation-induced mortality to diverse animal species under various exposure protocols were compiled into a mortality data base. Some 24 variables were extracted and recomputed from each of the published studies, which were collected from a variety of available sources, primarily journal articles. Two features of this compilation effort are (1) an attempt to give an estimate of the uniform dose received by the bone marrow in each treatment so that interspecies differences due to body size were minimized and (2) a recomputation of the LD/sub 50/ where sufficient experimental data are available. Exposure rates varied in magnitude from about 10/sup -2/ to 10/sup 3/ R/min. This report describes the data base, the sources of data, and the data-handling techniques; presents a bibliography of studies compiled; and tabulates data from each study. 103 refs., 44 tabs.

  11. Toxicity and motor changes in Africanized honey bees (Apis mellifera L.) exposed to fipronil and imidacloprid.

    Science.gov (United States)

    Bovi, Thaís S; Zaluski, Rodrigo; Orsi, Ricardo O

    2018-01-01

    This study evaluated the in vitro toxicity and motor activity changes in African-derived adult honey bees (Apis mellifera L.) exposed to lethal or sublethal doses of the insecticides fipronil and imidacloprid. Mortality of bees was assessed to determine the ingestion and contact lethal dose for 24 h using probit analysis. Motor activities in bees exposed to lethal (LD50) and sublethal doses (1/500th of the lethal dose) of both insecticides were evaluated in a behavioral observation box at 1 and 4 h. Ingestion and contact lethal doses of fipronil were 0.2316 ? 0.0626 and 0.0080 ? 0.0021 μg/bee, respectively. Ingestion and contact lethal doses of imidacloprid were 0.1079 ? 0.0375 and 0.0308 ? 0.0218 μg/bee, respectively. Motor function of bees exposed to lethal doses of fipronil and imidacloprid was impaired; exposure to sublethal doses of fipronil but not imidacloprid impaired motor function. The insecticides evaluated in this study were highly toxic to African-derived A. mellifera and caused impaired motor function in these pollinators.

  12. Pluripotent stem cells with normal or reduced self renewal survive lethal irradiation

    International Nuclear Information System (INIS)

    Brecher, G.; Neben, S.; Yee, M.; Bullis, J.; Cronkite, E.P.

    1988-01-01

    Transfusion with 10,000 or 20,000 marrow cells resulted in 30+ days survival of 15%-50% of mice exposed to an Ld90 or LD100 or radiation. The use of congenic mice with alloenzyme markers permitted the identification of host and donor cells in the peripheral blood of transfused animals. Donor cells were present initially in all hosts. Between 55% and 92% of the animals became 100% host type by 12-24 weeks after transfusion in three separate experiments. To explore whether the temporary repopulation by donor cells was due to short-lived stem cells, the marrows of several primary hosts were transfused into secondary, lethally irradiated hosts. Some of the retransplanted primary donor and host cells persisted only temporarily. It is suggested that some of the donor stem cells in both the primary and secondary hosts had an intrinsically shortened life span

  13. Straightening Beta: Overdispersion of Lethal Chromosome Aberrations following Radiotherapeutic Doses Leads to Terminal Linearity in the Alpha–Beta Model

    Directory of Open Access Journals (Sweden)

    Igor Shuryak

    2017-12-01

    Full Text Available Recent technological advances allow precise radiation delivery to tumor targets. As opposed to more conventional radiotherapy—where multiple small fractions are given—in some cases, the preferred course of treatment may involve only a few (or even one large dose(s per fraction. Under these conditions, the choice of appropriate radiobiological model complicates the tasks of predicting radiotherapy outcomes and designing new treatment regimens. The most commonly used model for this purpose is the venerable linear-quadratic (LQ formalism as it applies to cell survival. However, predictions based on the LQ model are frequently at odds with data following very high acute doses. In particular, although the LQ predicts a continuously bending dose–response relationship for the logarithm of cell survival, empirical evidence over the high-dose region suggests that the survival response is instead log-linear with dose. Here, we show that the distribution of lethal chromosomal lesions among individual human cells (lymphocytes and fibroblasts exposed to gamma rays and X rays is somewhat overdispersed, compared with the Poisson distribution. Further, we show that such overdispersion affects the predicted dose response for cell survival (the fraction of cells with zero lethal lesions. This causes the dose response to approximate log-linear behavior at high doses, even when the mean number of lethal lesions per cell is well fitted by the continuously curving LQ model. Accounting for overdispersion of lethal lesions provides a novel, mechanistically based explanation for the observed shapes of cell survival dose responses that, in principle, may offer a tractable and clinically useful approach for modeling the effects of high doses per fraction.

  14. The LDsub(50/30) and the survival time in whole-body gamma-irradiated conventional and germfree Minnesota miniature piglets

    International Nuclear Information System (INIS)

    Mandel, L.; Travnicek, J.; Talafantova, M.; Zahradnickova, M.

    1980-01-01

    The median lethal exposure causing the death in 30 days after single whole-body gamma-irradiation (the LD 50/30) was found to be 2731 MBq (73.8 mC/kg) for conventional piglets, but 3226 MBq (87.2 mC/kg) for germ-free piglets both irradiated 14 days after birth. After lethal exposures, the survival time in germ-free piglets was prolonged for 7 days in comparison with conventional piglets. (author)

  15. The comparative study of Yaz and Ovocept-ld on patients with simple ovarian cysts referring to Iran-Isfahan Shariati Hospital

    Directory of Open Access Journals (Sweden)

    Soheyla Riahinejad

    2014-01-01

    Full Text Available Background: Functional ovarian cysts include follicular, corpus luteum, and theca lutein cysts are the most common adnexal masses (about 50% in women of reproductive age. Treatment with the combined monophasic oral contraceptives reduces functional ovarian cysts. Yaz (drospirenone/ethinyl estradiol is a low-dose combined oral contraceptive pill containing 20 μg ethinyl estradiol and 3 mg drospirenone. In addition to contraceptive effects, Yaz has anti-mineralocorticoid and anti-adrenergic effects. Ovocept- low-dose LD is also a low-dose combined oral contraceptive drug containing 30 μg ethinyl estradiol and 3 mg norgestrol. Ovocept-LD has some side-effects such as weight gain, spotting, breast tenderness, nausea, and headache. Materials and Methods: Being a clinical study, the present research was carried out on 42 patients with the simple ovarian cysts from 2010 to 2012. 84 Patients were assigned to A and B groups. Group A received Yaz once a day for a period of 28 days and group B received Ovocept-LD once a day for a period of 21 days. After treating by Yaz and Ovocept-LD, Cysts were evaluated by ultrasound. Results were analyzed by the SPSS software. A P < 0.05 was considered the significance threshold. Results : Obtained results indicated that both Yaz and Ovocept-LD had an effect on the simple ovarian cysts. Statistical tests, however, has shown that the effect of Yaz has been significantly more than that of Ovocept-LD. Conclusion: Given the faster and better recovery effect, and the lesser side effects of Yaz as compared to Ovocept-LD, it is recommended to use Yaz for the simple ovarian cysts.

  16. Prediction of pesticide acute toxicity using two-dimensional chemical descriptors and target species classification

    Science.gov (United States)

    Previous modelling of the median lethal dose (oral rat LD50) has indicated that local class-based models yield better correlations than global models. We evaluated the hypothesis that dividing the dataset by pesticidal mechanisms would improve prediction accuracy. A linear discri...

  17. High-dose versus low-dose local anaesthetic for transversus abdominis plane block post-Caesarean delivery analgesia: a meta-analysis.

    Science.gov (United States)

    Ng, S C; Habib, A S; Sodha, S; Carvalho, B; Sultan, P

    2018-02-01

    The optimal local-anaesthetic (LA) dose for transversus-abdominis-plane (TAP) block is unclear. In this meta-analysis, we aimed to determine whether TAP blocks for Caesarean delivery (CD) with low-dose (LD) LA demonstrated non-inferiority in terms of analgesic efficacy, compared with high-dose (HD) LA. A literature search was performed for randomised controlled trials examining the analgesic efficacy of TAP blocks vs control after CD. The different dosing used in these studies was classified as HD or LD (bupivacaine equivalents >50 or ≤50 mg per block side, respectively). The pooled results of each dose group vs control were indirectly compared using the Q test. The primary outcome was 24 h opioid consumption. Secondary outcomes included 6 and 24 h postoperative pain scores, time to first analgesia, 6 h opioid consumption, opioid-related side-effects, and maternal satisfaction. Fourteen studies consisting of 770 women (389 TAP and 381 control) were included. Compared with controls, the 24 h opioid consumption (milligram morphine equivalents) was lower in HD [mean difference (MD) 95% confidence interval (CI) -22.41 (-38.56, -6.26); P=0.007; I 2 =93%] and LD [MD 95% CI -16.29 (-29.74, -2.84); P=0.02; I 2 =98%] TAP groups. However, no differences were demonstrated between the HD and LD groups (P=0.57). There were also no differences between the HD and LD groups for the 6 h opioid consumption, time to first analgesia, 6 and 24 h pain scores, postoperative nausea and vomiting, pruritus, and maternal satisfaction. Low-dose TAP blocks for Caesarean delivery provide analgesia and opioid-sparing effects comparable with the high-dose blocks. This suggests that lower doses can be used to reduce local anaesthetic toxicity risk without compromising the analgesic efficacy. Copyright © 2017 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

  18. Lithium-methomyl induced seizures in rats: A new model of status epilepticus?

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Rafal M [Department of Toxicology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Blaszczak, Piotr [Department of Toxicology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Dekundy, Andrzej [Department of Toxicology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Parada-Turska, Jolanta [Department of Rheumatology and Connective Tissue Diseases, Medical University, Jaczewskiego 8, 20-090 Lublin (Poland); Calderazzo, Lineu [Department of Neurology and Neurosurgery, Laboratory of Experimental Neurology, Escola Paulista de Medicina, R. Botucatu 862, BR-04023 Sao Paulo, S.P. (Brazil); Cavalheiro, Esper A [Department of Neurology and Neurosurgery, Laboratory of Experimental Neurology, Escola Paulista de Medicina, R. Botucatu 862, BR-04023 Sao Paulo, S.P. (Brazil); Turski, Waldemar A [Department of Toxicology, Institute of Agricultural Medicine, Jaczewskiego 2, 20-950 Lublin (Poland); Department of Experimental and Clinical Pharmacology, Medical University, Jaczewskiego 8, 20-090 Lublin (Poland)

    2007-03-15

    Behavioral, electroencephalographic (EEG) and neuropathological effects of methomyl, a carbamate insecticide reversibly inhibiting acetylcholinesterase activity, were studied in naive or lithium chloride (24 h, 3 mEq/kg, s.c.) pretreated male Wistar rats. In naive animals, methomyl with equal potency produced motor limbic seizures and fatal status epilepticus. Thus, the CD50 values (50% convulsant dose) for these seizure endpoints were almost equal to the LD50 (50% lethal dose) of methomyl (13 mg/kg). Lithium pretreated rats were much more susceptible to convulsant, but not lethal effect of methomyl. CD50 values of methomyl for motor limbic seizures and status epilepticus were reduced by lithium pretreatment to 3.7 mg/kg (a 3.5-fold decrease) and 5.2 mg/kg (a 2.5-fold decrease), respectively. In contrast, lithium pretreatment resulted in only 1.3-fold decrease of LD50 value of methomyl (9.9 mg/kg). Moreover, lithium-methomyl treated animals developed a long-lasting status epilepticus, which was not associated with imminent lethality observed in methomyl-only treated rats. Scopolamine (10 mg/kg) or diazepam (10 mg/kg) protected all lithium-methomyl treated rats from convulsions and lethality. Cortical and hippocampal EEG recordings revealed typical epileptic discharges that were consistent with behavioral seizures observed in lithium-methomyl treated rats. In addition, convulsions induced by lithium-methomyl treatment were associated with widespread neurodegeneration of limbic structures. Our observations indicate that lithium pretreatment results in separation between convulsant and lethal effects of methomyl in rats. As such, seizures induced by lithium-methomyl administration may be an alternative to lithium-pilocarpine model of status epilepticus, which is associated with high lethality.

  19. Lithium-methomyl induced seizures in rats: A new model of status epilepticus?

    International Nuclear Information System (INIS)

    Kaminski, Rafal M.; Blaszczak, Piotr; Dekundy, Andrzej; Parada-Turska, Jolanta; Calderazzo, Lineu; Cavalheiro, Esper A.; Turski, Waldemar A.

    2007-01-01

    Behavioral, electroencephalographic (EEG) and neuropathological effects of methomyl, a carbamate insecticide reversibly inhibiting acetylcholinesterase activity, were studied in naive or lithium chloride (24 h, 3 mEq/kg, s.c.) pretreated male Wistar rats. In naive animals, methomyl with equal potency produced motor limbic seizures and fatal status epilepticus. Thus, the CD50 values (50% convulsant dose) for these seizure endpoints were almost equal to the LD50 (50% lethal dose) of methomyl (13 mg/kg). Lithium pretreated rats were much more susceptible to convulsant, but not lethal effect of methomyl. CD50 values of methomyl for motor limbic seizures and status epilepticus were reduced by lithium pretreatment to 3.7 mg/kg (a 3.5-fold decrease) and 5.2 mg/kg (a 2.5-fold decrease), respectively. In contrast, lithium pretreatment resulted in only 1.3-fold decrease of LD50 value of methomyl (9.9 mg/kg). Moreover, lithium-methomyl treated animals developed a long-lasting status epilepticus, which was not associated with imminent lethality observed in methomyl-only treated rats. Scopolamine (10 mg/kg) or diazepam (10 mg/kg) protected all lithium-methomyl treated rats from convulsions and lethality. Cortical and hippocampal EEG recordings revealed typical epileptic discharges that were consistent with behavioral seizures observed in lithium-methomyl treated rats. In addition, convulsions induced by lithium-methomyl treatment were associated with widespread neurodegeneration of limbic structures. Our observations indicate that lithium pretreatment results in separation between convulsant and lethal effects of methomyl in rats. As such, seizures induced by lithium-methomyl administration may be an alternative to lithium-pilocarpine model of status epilepticus, which is associated with high lethality

  20. The effects of radiation dose-rate and quality on the induction of dominant lethals in mouse spermatids

    International Nuclear Information System (INIS)

    Searle, A.G.; Beechey, G.V.

    1981-01-01

    Hybrid male mice were given 3 Gy (300 rad) doses of X- or γ-irradiation at dose-rates of either 0.6 or 0.002 Gy/min for each radiation. Germ-cells treated as spermatids were tested for dominant lethality. Effects on spermatogonia were evaluated by studying testis-weight, sperm-count and sperm abnormalities. The rate of induction of dominant lethal mutations was 2.1 times as high after acute X-irradiation as after protracted γ-irradiation. Most of this difference resulted from the change in radiation quality, since the relative effectiveness of X- versus γ-irradiation was 1.9 at low and 1.6 at high dose rates. For each radiation, however, fewer dominant lethals were induced at low dose-rates than at high (low/high ratios of 0.8 and 0.9 respectively) although differences did not reach a significant level. There were no statistically significant effects of dose rate on testis-weight of sperm-count in the X-ray series, but there were significantly less severe effects on both with protraction of the γ-irradiation. Evidence for effects of radiation quality on these characters was conflicting. Frequencies of abnormal spermatozoa were markedly increased 7 weeks after irradiation but there were no consistent effects of radiation intensity or quality. (orig.)

  1. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation

    International Nuclear Information System (INIS)

    Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P.

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of γ radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [fr

  2. The involvement of IL-17A in the murine response to sub-lethal inhalational infection with Francisella tularensis.

    Directory of Open Access Journals (Sweden)

    Gal Markel

    2010-06-01

    Full Text Available Francisella tularensis is an intercellular bacterium often causing fatal disease when inhaled. Previous reports have underlined the role of cell-mediated immunity and IFNgamma in the host response to Francisella tularensis infection.Here we provide evidence for the involvement of IL-17A in host defense to inhalational tularemia, using a mouse model of intranasal infection with the Live Vaccine Strain (LVS. We demonstrate the kinetics of IL-17A production in lavage fluids of infected lungs and identify the IL-17A-producing lymphocytes as pulmonary gammadelta and Th17 cells. The peak of IL-17A production appears early during sub-lethal infection, it precedes the peak of immune activation and the nadir of the disease, and then subsides subsequently. Exogenous airway administration of IL-17A or of IL-23 had a limited yet consistent effect of delaying the onset of death from a lethal dose of LVS, implying that IL-17A may be involved in restraining the infection. The protective role for IL-17A was directly demonstrated by in vivo neutralization of IL-17A. Administration of anti IL-17A antibodies concomitantly to a sub-lethal airway infection with 0.1xLD(50 resulted in a fatal disease.In summary, these data characterize the involvement and underline the protective key role of the IL-17A axis in the lungs from inhalational tularemia.

  3. Vitamin D supplementation in nursing home patients: randomized controlled trial of standard daily dose versus individualized loading dose regimen.

    Science.gov (United States)

    Wijnen, Hugo; Salemink, Dayenne; Roovers, Lian; Taekema, Diana; de Boer, Hans

    2015-05-01

    Supplementation of cholecalciferol 800 IU daily appears to be insufficient to raise vitamin D levels to >75 nmol/l in nursing home (NH) patients. Our objective was to compare the efficacy of an individualized cholecalciferol loading dose (LD) regimen and a daily dose (DD) regimen of cholecalciferol 800 IU in reaching 25-OH vitamin D (25OHD) levels >75 nmol/l. A total of 30 NH patients with 25OHD levels 50 nmol/l were included. Patients were randomized using the minimization method in the LD or DD group. The cholecalciferol LD, calculated with an algorithm based on serum 25OHD level and body weight, was administered in divided doses of 50,000 IU twice a week, followed by a monthly maintenance dose of either 50,000 or 25,000 IU. The DD regimen consisted of cholecalciferol 800 IU daily for 26 weeks. Serum 25OHD, calcium, creatinine, phosphate, and parathyroid hormone were measured, and 2-minute walking test, handgrip strength, and timed get up and go test were assessed at baseline (T 0), after 5 weeks (T 5), 12 weeks (T 12), and 26 weeks (T 26). The primary endpoint was the percentage of patients with 25OHD levels >75 nmol/l at T 5. Secondary endpoints were the proportion of patients with 25OHD levels >75 nmol/l at T 26, safety of LD regimen, and improvement of performance tests with normalization of vitamin D levels. Median baseline 25OHD levels (interquartile range) were comparable between the 14 DD and 16 LD patients: 20.9 (15.9-29.6) and 21.7 (16.4-32.8) nmol/l, respectively. Levels of 25OHD >75 nmol/l at T 5 were reached in 79 % of the 14 LD patients, but in none of the 13 DD patients (p 75 nmol/l were reached in 83 % of the 12 LD patients and in 30 % of the ten DD patients (p tests was observed. In NH patients with severe 25OHD deficiency, an individualized calculated cholecalciferol LD is likely to be superior to a DD of cholecalciferol 800 IU in terms of the ability to rapidly normalize vitamin D levels.

  4. Data base on animal mortality

    International Nuclear Information System (INIS)

    Jones, T.D.

    1987-01-01

    A data base on animal mortality has been compiled. The literature on LD 50 and the dose-response function for radiation-induced lethality, reflect several inconsistencies - primarily due to dose assignments and to analytical methods and/or mathematical models used. Thus, in order to make the individual experiments which were included in the data base as consistent as possible, an estimate of the uniform dose received by the bone marrow in each treatment group was made so that the interspecies differences are minimized. The LD 50 was recalculated using a single estimation procedure for all studies for which sufficient experimental data are available. For small animals such as mice, the dose to the hematopoietic system is approximately equal to the treatment dose, but for large animals the marrow dose may be about half of the treatment dose

  5. Toxicidade para lagartas de Phthorimaea operculella (Zell. dos aleloquímicos 2-tridecanona e 2-undecanona presentes em tomateiro (Lycopersicon spp. Toxicity of 2-tridecanone and 2-undecanone allelochemicals present in tomato (Lycopersicon spp. for Phthorimaea operculella (Zell. larvae

    Directory of Open Access Journals (Sweden)

    M.U. Ventura

    1995-12-01

    Full Text Available Avaliou-se a toxicidade para Phthorimaea operculella (Zell. dos aleloquímicos 2-trídecanona e 2-undecanona, presentes nos exsudatos glandulares dos tricomas de Lycopersicon spp. Determinou-se a toxicidade dos exsudatos de L. hirsutum f. glabratum PI134417 (DL50, do 2-tridecanona (dose letal: DL50 e concentração letal: CL50 e do 2-undecanona (CL50 para lagartas de primeiro ínstar desse inseto. A DL50 foi de 5,54 glândulas e 775,53 ng por lagarta, respectivamente. Em relação à concentração letal, o 2-tridecanona foi mais tóxico do que o 2-undecanona. A toxicidade (CL50 do 2-tridecanona aumentou com a elevação da temperatura de 27 para 32°C e para o 2-undecanona ocorreu o inverso. Concluiu-se que estes compostos podem ter grande importância na resistência do tomateiro para esta praga.This research deals with the toxicity of 2-tridecanone and 2-undecanone allelochemicals, present in the grandular trichomes of Lycopersicon spp., to Phthorimaea operculella (Zell.. The toxicity of the exsudates of L. hirsutum f. glabratum PI 134117 (LD50, of the 2-tridecanone (lethal dose: LD50and lethal concentration: LC50 and 2-undecanone (LC50 to first instar larvae of this pest were determined. The LD50value was 5.54 glands and 775.53 ng per larvae, respectively. With respect to the lethal concentration, the 2-tridecanone was more toxic than the 2-undecanone. The toxicity (CL50 of the 2-tridecanone increased with the elevation of the temperature from 27 to 32°C, but decreased with the 2-undecanone. It was concluded that these compounds can have great importance in the resistance of the tomato plant to this pest.

  6. Relationship of dose rate and total dose to responses of continuously irradiated beagles

    International Nuclear Information System (INIS)

    Fritz, T.E.; Norris, W.P.; Tolle, D.V.; Seed, T.M.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.

    1978-01-01

    Young-adult beagles were exposed continuously (22 hours/day) to 60 Co γ rays in a specially constructed facility. The exposure rates were either 5, 10, 17, or 35 R/day, and the exposures were terminated at either 600, 1400, 2000, or 4000 R. A total of 354 dogs were irradiated; 221 are still alive as long-term survivors, some after more than 2000 days. The data on survival of these dogs, coupled with data from similar preliminary experiments, allow an estimate of the LD 50 for γ-ray exposures given at a number of exposure rates. They also allow comparison of the relative importance of dose rate and total dose, and the interaction of these two variables, in the early and late effects after protracted irradiation. The LD 50 for the beagle increases from 258 rad delivered at 15 R/minute to approximately 3000 rad at 10 R/day. Over this entire range, the LD 50 is dependent upon hematopoietic damage. At 5 R/day and less, no meaningful LD 50 can be determined; there is nearly normal continued hematopoietic function, survival is prolonged, and the dogs manifest varied individual responses in other organ systems. Although the experiment is not complete, interim data allow several important conclusions. Terminated exposures, while not as effective as radiation continued until death, can produce myelogenous leukemia at the same exposure rate, 10 R/day. More importantly, at the same total accumulated dose, lower exposure rates are more damaging than higher rates on the basis of the rate and degree of hematological recovery that occurs after termination of irradiation. Thus, the rate of hematologic depression, the nadir of the depression, and the rate of recovery are dependent upon exposure rate; the latter is inversely related and the former two are directly related to exposure rate

  7. Relationship of dose rate and total dose to responses of continuously irradiated beagles

    International Nuclear Information System (INIS)

    Fritz, T.E.; Norris, W.P.; Tolle, D.V.; Seed, T.M.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.

    1978-01-01

    Young-adult beagles were exposed continuously (22 hours/day) to 60 Co gamma rays in a specially constructed facility. The exposure rates were 5, 19, 17 or 35 R/day, and the exposures were terminated at 600, 1400, 2000 or 4000 R. A total of 354 dogs were irradiated; 221 are still alive as long-term survivors, some after more than 2000 days. The data on survival of these dogs, coupled with data from similar preliminary experiments, allow an estimate of the LD 50 for gamma-ray exposures given at a number of exposure rates. They also allow comparison of the relativeimportance of dose rate and total dose, and the interaction of these two variables, in the early and late effects after protracted irradiation. The LD 50 for the beagle increases from 344 R (258 rads) delivered at 15 R/minute to approximately 4000 R (approximately 3000 rads) at 10 R/day. Over this entire range, the LD 50 is dependent upon haematopoietic damage. At 5 R/day and less, no definitive LD 50 can be determined; there is nearly normal continued haematopoietic function, survival is prolonged, and the dogs manifest varied individual responses in the organ systems. Although the experiment is not complete, interim data allow serveral important conclusions. Terminated exposures, while not as effective as irradiation continued until death, can produce myelogenous leukaemia at the same exposure rate, 10 R/day. More importantly, at the same total accumulated dose, lower exposure rates appear more damaging than higher rates on the basis of the rate and degree of haematological recovery that occurs after termination of irradiation. Thus, the rate of haematologic depression, the nadir of the depression and the rate of recovery are dependent upon exposure rate; the latter is inversely related and the first two are directly related to exposure rate. ( author)

  8. Dose response toxic effects of different oximes in vivo: pathohystological evaluation

    International Nuclear Information System (INIS)

    Jacevic, V.

    2009-01-01

    The acute toxicity of oximes is crucial for the assessment of a dose applied as a treatment for organophosphorus intoxications. This is why we decided to investigate which morphological lesions could be produced in Wistar rats after treatment with increasing doses of HI-6, Obidoxime, K027, K048, and K075. In the first part of this study, tested oximes were preliminarily tested in order to obtain their LD50 values. Survival rates were monitored 24 hours after application of each oxime. In separate experiment animals were sacrificed 7 days after single im application of 0.1 LD50 and 0.5 LD50 of each oxime, and hearts, diaphragms and musculus popliteus were obtained for pathohistological analysis. Tissue damage score (TDS) was based on an estimation scale from 0 (no damage) to 5 (strong damage, massive necrotic fields). In rats treated with of 0.1 LD50 of HI-6 and K027 microscopic findings were similar to those evaluated in the control groups, only. More intensive alterations, but still mild and reversible degenerative and vascular changes, were established in tissue samples after treatment with 0.1 LD50 of Obidoxime, K048 and K075, but their values were also similar to the control group. Acute lesions were developed in tissue samples within 7 days following treatment with 0.5 LD50 of all oximes. The most severe tissue alterations were found in rats treated with 0.5 LD50 of K048 and K075 (p < 0.001 vs. control and HI-6). These observations of the earliest tissues events are helping to guide of applications of novel development oximes.(author)

  9. Dose response and mutation induction by ion beam irradiation in buckwheat

    International Nuclear Information System (INIS)

    Morishita, T.; Yamaguchi, H.; Degi, K.; Shikazono, N.; Hase, Y.; Tanaka, A.; Abe, T.

    2003-01-01

    The biological effects of ion beams were investigated to pursue the development of a method for breeding by mutation in buckwheat. Common buckwheat (Botansoba, Bot) and tartary buckwheat (Rotundatiem, Rot) seeds were exposed to various ions in linear energy transfer (LET) at 9-630 keV/μm. The lethal dose 50 (LD 50 ) of ion beams were 10-300 Gy (Bot) and 30-500 Gy (Rot). It was indicated that a penetrating depth in excess of 1.7 mm is necessary to thoroughly saturate the target, and ions with a penetrating depth of less than 2.2 mm were affected by the presence of hulls. The maximum values of the relative biological effectiveness were 17.7 (Rot) and 22.5 (Bot) at 305 keV/μm. The effective cross sections increased with the LET, and the maximum values were 2.7 (Rot) and 3.0 μm 2 (Bot). The mutation induction effects of He and C ions were higher than those of gamma rays

  10. Experimental Salmonella typhimurium infections in rats. II. Active and passive immunization as protection against a lethal bacterial dose

    DEFF Research Database (Denmark)

    Hougen, H P; Jensen, E T; Klausen, B

    1990-01-01

    Immunization against a lethal dose of Salmonella typhimurium was studied in athymic and thymus-bearing LEW rats. Active immunization was performed with formalin-killed whole cell vaccine or sublethal infection prior to the lethal infection. After vaccination with killed bacteria the euthymic...... from immunized thymus grafted animals provided only limited protective effect, and treatment with cells from athymic animals had no effect. The study shows that although isogeneic thymus-grafted nude rats become resistent to reinfection with S. typhimurium, only large doses of spleen cells from...

  11. Formulated Beta-Cyfluthrin Shows Wide Divergence in Toxicity among Bird Species

    OpenAIRE

    Addy-Orduna, Laura M.; Zaccagnini, María-Elena; Canavelli, Sonia B.; Mineau, Pierre

    2011-01-01

    It is generally assumed that the toxicity of pyrethroid insecticides to birds is negligible, though few species have been tested. The oral acute toxicity of formulated beta-cyfluthrin was determined for canaries (Serinus sp.), shiny cowbirds (Molothrus bonariensis), and eared doves (Zenaida auriculata). Single doses were administered to adults by gavage. Approximate lethal doses 50 (LD50) and their confidence intervals were determined by approximate D-optimal design. Canaries were found to be...

  12. Comparison of Weibull and Probit Analysis in Toxicity Testing of ...

    African Journals Online (AJOL)

    HP

    Keywords: Hunteria umbellata, Weibull model, Acute toxicity, Median lethal dose (LD50). Received: 7 November ... (PBPK) models [14,15], and (v) biologically-. Based Models: Moolgavkar-Venzon-Kundson. (MVK) model [16] and Ellwein and Cohen model [17]. ... Nigeria, Ibadan, where a sample with number. FHI107618 ...

  13. Effect of exposure routes on the relationships of lethal toxicity to rats from oral, intravenous, intraperitoneal and intramuscular routes.

    Science.gov (United States)

    Ning, Zhong H; Long, Shuang; Zhou, Yuan Y; Peng, Zi Y; Sun, Yi N; Chen, Si W; Su, Li M; Zhao, Yuan H

    2015-11-01

    The lethal toxicity values (log 1/LD(50)) of 527 aliphatic and aromatic compounds in oral, intravenous, intramuscular and intraperitoneal routes were used to investigate the relationships of log 1/LD(50) from different exposure routes. Regression analysis shows that the log 1/LD(50) values are well correlated between intravenous and intraperitoneal or intramuscular injections. However, the correlations between oral and intravenous or intraperitoneal routes are relatively poor. Comparison of the average residuals indicates that intravenous injection is the most sensitive exposure route and oral administration is the least sensitive exposure route. This is attributed to the difference in kinetic process of toxicity testing. The toxic effect of a chemical can be similar or significantly different between exposure routes, depending on the absorption rates of chemicals into blood. Inclusion of hydrophobic parameter and fractions of ionic forms can improve the correlations between intravenous and intraperitoneal or oral routes, but not between intraperitoneal and oral routes. This is due to the differences of absorption rate in different exposure environments from different routes. Several factors, such as experimental uncertainty, metabolism and toxic kinetics, can affect the correlations between intravenous and intraperitoneal or oral routes. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. IV. Effect of 60Co gamma rays on survival rate of China aster plants (Callistephus chinensis Nees in M1 generations - under field conditions

    Directory of Open Access Journals (Sweden)

    A. Wosińska

    2013-12-01

    Full Text Available Studies were undertaken on the effect of different doses of gamma radiation on survival rate of plants (germinated from irradiated seeds for 5 China aster varieties specified at florescence time. During their growth under field conditions (from planting time to blooming lethal effect of the radiation occurred in plants of all varieties and its level depended on dose and variety. Effect of 3 kR and 6 kR doses differed depending on variety and was not always harmful, but following irradiation with doses exceeding 6 kR a considerable decrease in survival rate was observed. Radioresistance of studied varieties - measured both: by LD50 and LDl00 - differed; depending on variety, LD50 and LDl00 values fluctuated: from 6 to 9 kR and 12 to 15 kR respectively.

  15. An acute toxicity study of Heliotropium scottae Rendle in mice.

    Science.gov (United States)

    Wahome, W M; Muchiri, D J; Mugera, G M

    1994-08-01

    Twenty-four hour ip median lethal doses (LD50) of freeze-dried aqueous extracts of Heliotropium scottae Rendle leaves and stems in mice were determined and clinical signs noted. The LD50 of the leaf extract was 3.0 g/kg, while that of the stems was 3.5 g/kg. Clinical signs were excitement, prostration, rapid breathing, gasping for breath and death. The signs were the same for both the leaf and stem extracts. It was concluded that both the leaves and stems of H scottae have slight acute toxicity.

  16. Sensitiveness of jasmine cuttings to gamma radiation

    International Nuclear Information System (INIS)

    Devaiah, K.A.; Srivastava, H.C.

    1989-01-01

    Half lethal dose (LD 50 ) gamma radiation for five genotypes of jasmine and the effect of such radiation on their rooting parameters were studied. The LD 50 was close to 2.5 krad for Jasminum grandiflorum var. Pink Pin, 0.5 krad for var. Pink Thrum, 2.5 krad for J. flexile Valh., 1 krad for J. calophyllum Wall and 2 krad for J. sambac Ait var. 'Gundumalli'. Percentage of rooting, number of roots per cutting, length and thickness of roots decreased with increase in intensity of gamma irradiation. (author) 8 refs.; 4 tabs

  17. Acute toxicity of organophosphorus compounds in guinea pigs is sex- and age-dependent and cannot be solely accounted for by acetylcholinesterase inhibition.

    Science.gov (United States)

    Fawcett, William P; Aracava, Yasco; Adler, Michael; Pereira, Edna F R; Albuquerque, Edson X

    2009-02-01

    This study was designed to test the hypothesis that the acute toxicity of the nerve agents S-[2-(diisopropylamino)ethyl]-O-ethyl methylphosphonothioate (VX), O-pinacolyl methylphosphonofluoridate (soman), and O-isopropyl methylphosphonofluoridate (sarin) in guinea pigs is age- and sex-dependent and cannot be fully accounted for by the irreversible inhibition of acetylcholinesterase (AChE). The subcutaneous doses of nerve agents needed to decrease 24-h survival of guinea pigs by 50% (LD(50) values) were estimated by probit analysis. In all animal groups, the rank order of LD(50) values was sarin > soman > VX. The LD(50) value of soman was not influenced by sex or age of the animals. In contrast, the LD(50) values of VX and sarin were lower in adult male than in age-matched female or younger guinea pigs. A colorimetric assay was used to determine the concentrations of nerve agents that inhibit in vitro 50% of AChE activity (IC(50) values) in guinea pig brain extracts, plasma, red blood cells, and whole blood. A positive correlation between LD(50) values and IC(50) values for AChE inhibition would support the hypothesis that AChE inhibition is a major determinant of the acute toxicity of the nerve agents. However, such a positive correlation was found only between LD(50) values and IC(50) values for AChE inhibition in brain extracts from neonatal and prepubertal guinea pigs. These results demonstrate for the first time that the lethal potencies of some nerve agents in guinea pigs are age- and sex-dependent. They also support the contention that mechanisms other than AChE inhibition contribute to the lethality of nerve agents.

  18. Toxicity of Imidacloprid to the Stingless Bee Scaptotrigona postica Latreille, 1807 (Hymenoptera: Apidae).

    Science.gov (United States)

    Soares, Hellen Maria; Jacob, Cynthia Renata Oliveira; Carvalho, Stephan Malfitano; Nocelli, Roberta Cornélio Ferreira; Malaspina, Osmar

    2015-06-01

    The stingless bee Scaptotrigona postica is an important pollinator of native and cultivated plants in Brazil. Among the factors affecting the survival of these insects is the indiscriminate use of insecticides, including the neonicotinoid imidacloprid. This work determined the toxicity of imidacloprid as the topical median lethal dose (LD50) and the oral median lethal concentration (LC50) as tools for assessing the effects of this insecticide. The 24 and 48 h LD50 values were 25.2 and 24.5 ng of active ingredient (a.i.)/bee, respectively. The 24 and 48 h LC50 values were 42.5 and 14.3 ng a.i./µL of diet, respectively. Ours results show the hazard of imidacloprid and the vulnerability of stingless bees to it, providing relevant toxicological data that can used in mitigation programs to ensure the conservation of this species.

  19. Subacute Low Dose Nerve Agent Exposure Causes DNA Fragmentation in Guinea Pig Leukocytes

    Science.gov (United States)

    2005-10-01

    1 SUBACUTE LOW DOSE NERVE AGENT EXPOSURE CAUSES DNA FRAGMENTATION IN GUINEA PIG LEUKOCYTES. Jitendra R. Dave1, John R. Moffett1, Sally M...DNA fragmentation in blood leukocytes from guinea pigs by ‘Comet’ assay after exposure to soman at doses ranging from 0.1LD50 to 0.4 LD50, once per...computer. Data obtained for exposure to soman demonstrated significant increases in DNA fragmentation in circulating leukocytes in CWNA treated guinea pigs as

  20. Ultra-low dose of Mycobacterium tuberculosis aerosol creates partial infection in mice.

    Science.gov (United States)

    Saini, Divey; Hopkins, Gregory W; Seay, Sarah A; Chen, Ching-Ju; Perley, Casey C; Click, Eva M; Frothingham, Richard

    2012-03-01

    A murine low dose (LD) aerosol model is commonly used to test tuberculosis vaccines. Doses of 50-400 CFU (24h lung CFU) infect 100% of exposed mice. The LD model measures progression from infection to disease based on organ CFU at defined time points. To mimic natural exposure, we exposed mice to an ultra-low dose (ULD) aerosol. We estimated the presented dose by sampling the aerosol. Female C57BL/6 mice were exposed to Mycobacterium tuberculosis H37Rv aerosol at 1.0, 1.1, 1.6, 5.4, and 11 CFU presented dose, infecting 27%, 36%, 36%, 100%, and 95% of mice, respectively. These data are compatible with a stochastic infection event (Poisson distribution, weighted R(2)=0.97) or with a dose-response relationship (sigmoid distribution, weighted R(2)=0.97). Based on the later assumption, the ID50 was 1.6CFU presented dose (95% confidence interval, 1.2-2.1). We compared organ CFU after ULD and LD aerosols (5.4 vs. 395CFU presented dose). Lung burden was 30-fold lower in the ULD model at 4 weeks (3.4 vs. 4.8 logs, pLD aerosols had greater within-group CFU variability. Exposure to ULD aerosols leads to infection in a subset of mice, and to persistently low organ CFU. The ULD aerosol model may resemble human pulmonary tuberculosis more closely than the standard LD model, and may be used to identify host or bacterial factors that modulate the initial infection event. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Successful Treatment of Acute Lethal Dose of Acrylamide Poisoning

    Directory of Open Access Journals (Sweden)

    Ali Banagozar Mohammadi

    2015-03-01

    Full Text Available Background: Acrylamide (C3H5NO is a vinyl monomer. This water-soluble crystalline solid is a colorless, odorless agent which is used in scientific laboratories and some industries. Acrylamide has cellular oxidative effects. Acute or chronic poisoning with this agent happens as a result of skin, respiratory, or oral contacts. Clinical manifestations depend on the dose, duration, and frequency of contact. Management of these patients consists of conservative and palliative therapies to reduce the oxidative effects. Case: The case was a 29-year-old girl with a Master of Sciences degree in genetics who worked in a university research center with previous history of depression. She had ingested 100cc of 30% Acrylamide solution for intentional suicide attempt. The patient was successfully managed using N-acetyl cysteine, vitamin C, and melatonin. Conclusion: Early diagnosis and appropriate treatment with recommended agents together with supportive therapies can save the life of patients exposed to potentially lethal doses of acrylamide, although intentional or accidental.

  2. Delayed neurotoxicity - do trichlorphon and/or dichlorvos cause delayed neuropathy in man or in test animals?

    Science.gov (United States)

    Johnson, M K

    1981-01-01

    Many, but not all, reports of delayed neuropathy associated with acute poisoning by trichlorphon refer to cases in U.S.S.R. Adulteration of technical trichlorphon with the ethyl analogue would greatly increase the neurotoxic hazard but analysis of a few samples has not revealed such impurities. Simultaneous ingestion of alcohol does not appear to increase neuropathic hazard. In hens double doses of trichlorphon each exceeding unprotected LD50 can produce moderate neuropathy associated with appropriately high inhibitions of neurotoxic esterase. Similar results are obtained with 2 doses of 10 x LD50 of dichlorvos. In vitro the inhibitory power of dichlorvos against neurotoxic esterase of hen brain is 0.02 x the power against acetylcholinesterase. This ratio correlates reasonably with the ratio of LD50/neuropathic dose. The factor for human brain enzymes is 0.06 suggesting that man is more susceptible to neuropathic effects of near-lethal doses of circulating dichlorvos. It is concluded that the only neuropathic hazard to man from good quality trichlorphon arises from rapid ingestion of massive doses. To obtain critical levels of inhibition of neurotoxic esterase and to cause neuropathy in man by repeated doses would require each dose to be severely toxic. Dichlorvos ingested in large doses is likely to kill rather than to cause neuropathy.

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

    Science.gov (United States)

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

    2016-01-01

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

  4. Comparative studies of dose-response curves for recessive lethal mutations induced by ethylnitrosourea in spermatogonia and in spermatozoa of Drosophila melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, I.; Ayaki, T.; Ohshima, K.

    1984-01-01

    Induction of recessive lethal mutation by N-ethyl-N-nitrosourea (ENU) was studied for the second chromosome of spermatogonia and spermatozoa in Drosophila melanogaster. ENU (0.03, 0.3, and 1.0 mM) was given to flies by dissolving it in feeding sucrose solution. When plotted against absorbed doses of ENU, the observed frequencies to recessive lethals showed a linear relationship for induction in spermatozoa but a sigmoidal relationship for induction in spermatogonia. These results suggest that in spermatogonia ENU-induced mutational damage is more repairable in a lower dose range of ENU. Mosaic lethal mutations were induced by ENU but not in spermatogonia.

  5. Protection of lethally irradiated mice with allogeneic fetal liver cells: influence of irradiation dose on immunologic reconstitution

    International Nuclear Information System (INIS)

    Tulunay, O.; Good, R.A.; Yunis, E.J.

    1975-01-01

    After lethal irradiation long-lived, immunologically vigorous C3Hf mice were produced by treatment with syngeneic fetal liver cells or syngeneic newborn or adult spleen cells. Treatment of lethally irradiated mice with syngeneic or allogeneic newborn thymus cells or allogeneic newborn or adult spleen cells regularly led to fatal secondary disease or graft-versus-host reactions. Treatment of the lethally irradiated mice with fetal liver cells regularly yielded long-lived, immunologically vigorous chimeras. The introduction of the fetal liver cells into the irradiated mice appeared to be followed by development of immunological tolerance of the donor cells. The findings suggest that T-cells at an early stage of differentiation are more susceptible to tolerance induction than are T-lymphocytes at later stages of differentiation. These investigations turned up a perplexing paradox which suggests that high doses of irradiation may injure the thymic stroma, rendering it less capable of supporting certain T-cell populations in the peripheral lymphoid tissue. Alternatively, the higher and not the lower dose of irradiation may have eliminated a host cell not readily derived from fetal liver precursors which represents an important helper cell in certain cell-mediated immune functions, e.g., graft-versus-host reactions, but which is not important in others, e.g., allograft rejections. The higher dose of lethal irradiation did not permit development or maintenance of a population of spleen cells that could initiate graft-versus-host reactions but did permit the development of a population of donor cells capable of achieving vigorous allograft rejection

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

    Science.gov (United States)

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

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

  7. DistiLD Database

    DEFF Research Database (Denmark)

    Palleja, Albert; Horn, Heiko; Eliasson, Sabrina

    2012-01-01

    Genome-wide association studies (GWAS) have identified thousands of single nucleotide polymorphisms (SNPs) associated with the risk of hundreds of diseases. However, there is currently no database that enables non-specialists to answer the following simple questions: which SNPs associated...... with diseases are in linkage disequilibrium (LD) with a gene of interest? Which chromosomal regions have been associated with a given disease, and which are the potentially causal genes in each region? To answer these questions, we use data from the HapMap Project to partition each chromosome into so-called LD...... blocks, so that SNPs in LD with each other are preferentially in the same block, whereas SNPs not in LD are in different blocks. By projecting SNPs and genes onto LD blocks, the DistiLD database aims to increase usage of existing GWAS results by making it easy to query and visualize disease...

  8. Develop a Biomedical Database on the Medical Aspects of Chemical Defense. Volume 2

    Science.gov (United States)

    1981-10-23

    THE MOUSE AND RATS, DAM GREATLY ENHANCED THE DES- TRUCTION OF SARIN; AT 1 MM DAM, SARIN IN THE RAT WAS COMPLETELY HYDROLYZED IN 2 MIN. RESULTS CONFIRMED...EARLIER FINDINGS THAT DAM UNTIL SARIN IS HYDROLYZED . A SUBSEQUENT PAPER FROM THIS STUDY DEALS WITH SOMAN. BASIS KEY :24 RECORD SECURITY :0 I I, I...NT Rabbits NT Rats RT Animal testing UF Animals, laboratory Lacunae Lanthanum 7439-91-0 LD50 NT -ethal dose UF Lethal dose 50 Lecithins General term

  9. Sub-Lethal Dose of Shiga toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cythoarquitecture.

    Directory of Open Access Journals (Sweden)

    Luciana eD’Alessio

    2016-02-01

    Full Text Available Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test, and ultrastructural analysis (transmission electron microscope. Intravenous administration of vehicle (control group, sub-lethal dose of 0.5 ηg and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n=6. Blood–Brain Barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance.

  10. 108 - 114_Tanko_ Anti-Diabetic

    African Journals Online (AJOL)

    pc

    2017-06-01

    Jun 1, 2017 ... excessive nicotinamide adenine dinucleotide phosphate- oxidase ... Acute toxicity study. The lethal dose (LD50) of the plant extract was determined by the method of Lorke (1983) using 12 mice. In the first phase, mice were divided into 3 groups of 3 ... They were observed for 24 hours for signs of toxicity.

  11. The Efficacy of Reduced-dose Dasatinib as a Subsequent Therapy in Patients with Chronic Myeloid Leukemia in the Chronic Phase: The LD-CML Study of the Kanto CML Study Group

    Science.gov (United States)

    Iriyama, Noriyoshi; Ohashi, Kazuteru; Hashino, Satoshi; Kimura, Shinya; Nakaseko, Chiaki; Takano, Hina; Hino, Masayuki; Uchiyama, Michihiro; Morita, Satoshi; Sakamoto, Junichi; Sakamaki, Hisashi; Inokuchi, Koiti

    2017-01-01

    Objective The aim of this study was to prospectively investigate the efficacy and safety profiles of low-dose dasatinib therapy (50 mg once daily). Methods Patients with chronic myeloid leukemia in the chronic phase (CML-CP) who were being treated with low-dose imatinib (≤200 mg/day), but were resistant to this agent were enrolled in the current study (referred to as the LD-CML study). Results There subjects included 9 patients (4 men and 5 women); all were treated with dasatinib at a dose of 50 mg once daily. Among 8 patients who had not experienced major molecular response (MMR; BCR-ABL1 transcript ≤0.1% according to International Scale [IS]) at study enrollment, 5 attained MMR by 12 months. In particular, 3 of 9 patients demonstrated a deep molecular response (DMR; IS ≤0.0069%) by 18 months. Five patients developed lymphocytosis accompanied by cytotoxic lymphocyte predominance. There was no mortality or disease progression, and all continue to receive dasatinib therapy at 18 months with only 2 patients requiring dose reduction. Toxicities were mild-to-moderate, and pleural effusion was observed in 1 patient (grade 1). Conclusion Low-dose dasatinib can attain MMR and DMR without severe toxicity in patients with CML-CP who are unable to achieve MMR with low-dose imatinib. Switching to low-dose dasatinib should therefore be considered for patients in this setting, especially if they are otherwise considering a cessation of treatment. PMID:29033428

  12. Galleria mellonella infection model demonstrates high lethality of ST69 and ST127 uropathogenic E. coli.

    Directory of Open Access Journals (Sweden)

    Majed F Alghoribi

    Full Text Available Galleria mellonella larvae are an alternative in vivo model for investigating bacterial pathogenicity. Here, we examined the pathogenicity of 71 isolates from five leading uropathogenic E. coli (UPEC lineages using G. mellonella larvae. Larvae were challenged with a range of inoculum doses to determine the 50% lethal dose (LD50 and for analysis of survival outcome using Kaplan-Meier plots. Virulence was correlated with carriage of a panel of 29 virulence factors (VF. Larvae inoculated with ST69 and ST127 isolates (10(4 colony-forming units/larvae showed significantly higher mortality rates than those infected with ST73, ST95 and ST131 isolates, killing 50% of the larvae within 24 hours. Interestingly, ST131 isolates were the least virulent. We observed that ST127 isolates are significantly associated with a higher VF-score than isolates of all other STs tested (P≤0.0001, including ST69 (P<0.02, but one ST127 isolate (strain EC18 was avirulent. Comparative genomic analyses with virulent ST127 strains revealed an IS1 mediated deletion in the O-antigen cluster in strain EC18, which is likely to explain the lack of virulence in the larvae infection model. Virulence in the larvae was not correlated with serotype or phylogenetic group. This study illustrates that G. mellonella are an excellent tool for investigation of the virulence of UPEC strains. The findings also support our suggestion that the incidence of ST127 strains should be monitored, as these isolates have not yet been widely reported, but they clearly have a pathogenic potential greater than that of more widely recognised clones, including ST73, ST95 or ST131.

  13. Acute toxicity and mutagenesis of three metabolites mixture of nitrobenzene in mice.

    Science.gov (United States)

    Wang, Guixia; Zhang, Xiuying; Yao, Chunzhu; Tian, Meizhan

    2011-03-01

    Nitrobenzene is a synthetic compound, more than 95% of which is used in the production of aniline. Nitrobenzene has been demonstrated to be substantially metabolized to p-Nitrophenol, p-Aminophenol and p-Nitroaniline in food animals (e.g., bovines, fowls). There have been no studies on the acute toxicity and the mutagenesis of the mixture of the three metabolites mentioned above. The aim of the present study is to testify the acute toxicity and the mutagenesis of the three metabolites mixture. Seventy Kunming mice (half male, half female) received an intragastric administration exposure to metabolites-containing suspension of 750, 638, 542, 461, 392, 333 mg kg(-1) body weight and 0.5% sodium carboxymethyl cellulose (control), followed by a 14-day observation. The medial lethal dose (LD(50)) concentration for nitrobenzene metabolites mixture in this study was 499.92 mg/kg. Their mutagenic toxicology was studied through micronucleus and sperm abnormality test. Kunming mice were twice intragastrically exposed to 1/5 LD(50), 1/10 LD(50), 1/20 LD(50) mg kg(-1) nitrobenzene metabolites-containing suspension spaced 24-h apart. Cyclophosphamide, pure water and sodium carboxymethyl cellulose served as doses of the positive group, the negative group and the solvent control group, respectively. The incidence of micronucleus and sperm abnormality increased significantly in the 1/5 LD(50) and 1/10 LD(50) group compared with the negative and solvent control group. A dose-related increase in the incidence of micronucleus and sperm abnormality was noted. In conclusion, the three metabolites mixture of nitrobenzene was secondary toxicity and mutagenic substances in mice.

  14. Influence of radioprotectors on total body weight evolution and on oxygen consumption in lethal dose irradiated animals. (Preliminary study)

    International Nuclear Information System (INIS)

    Fatome, M.; Martine, G.; Bargy, E.; Andrieu, L.

    Comparison of total body weight evolution and oxygen consumption in lethal dose irradiated animals, protected by various well known radioprotective substances, isolated or in mixture, with evolution and consumption of non protected animals irradiated at the same dose and with these of check animals [fr

  15. Study of radioprotective effect of the resveratrol;Estudo do efeito radioprotetor do resveratrol

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina dos Santos

    2009-07-01

    Resveratrol (3,4,5 trihydroxystilbene), a phenolic phytoalexin occurring naturally in a wide variety of plants, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is present at high levels and is considered one of the highest antioxidant constituents. This high capacity to scavenge the free radicals generated by several biologic processes by resveratrol can provide a prevention of human cardiovascular diseases and several types of cancer. The main objective of this study was to determine the in vitro radioprotective effect of resveratrol in cell culture with the aid of the tests of cytotoxicity of resveratrol (IC50%) and lethal dose 50% of gamma radiation (LD50). Studies of the level of resveratrol toxicity, found by cytotoxicity test performed by neutral red uptake assay, and lethal dose 50% (LD50) of gamma radiation from source of Cobalt-60 (Co-60) was performed in cell culture NCTC Clone 929 from ATCC. The IC50% of resveratrol was about 50 M/L. The DL50 of gamma radiation showed a value of about 354 Gy. On the basis of these biological results, it was performed studies of radioprotective effect of resveratrol on the same experimental conditions, verifying that the resveratrol in concentrations between 12.5 M/L and 25 M/L showed a more pronounced radioprotective effect. (author)

  16. Study of radioprotective effect of the resveratrol

    International Nuclear Information System (INIS)

    Moreno, Carolina dos Santos

    2009-01-01

    Resveratrol (3,4,5 trihydroxystilbene), a phenolic phytoalexin occurring naturally in a wide variety of plants, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is present at high levels and is considered one of the highest antioxidant constituents. This high capacity to scavenge the free radicals generated by several biologic processes by resveratrol can provide a prevention of human cardiovascular diseases and several types of cancer. The main objective of this study was to determine the in vitro radioprotective effect of resveratrol in cell culture with the aid of the tests of cytotoxicity of resveratrol (IC50%) and lethal dose 50% of gamma radiation (LD50). Studies of the level of resveratrol toxicity, found by cytotoxicity test performed by neutral red uptake assay, and lethal dose 50% (LD50) of gamma radiation from source of Cobalt-60 (Co-60) was performed in cell culture NCTC Clone 929 from ATCC. The IC50% of resveratrol was about 50 M/L. The DL50 of gamma radiation showed a value of about 354 Gy. On the basis of these biological results, it was performed studies of radioprotective effect of resveratrol on the same experimental conditions, verifying that the resveratrol in concentrations between 12.5 M/L and 25 M/L showed a more pronounced radioprotective effect. (author)

  17. Insecticide susceptibility of Nezara viridula (Heteroptera: Pentatomidae) and three other stink bug species composing a soybean pest complex in Japan.

    Science.gov (United States)

    Takeuchi, Hiroaki; Endo, Nobuyuki

    2012-06-01

    The susceptibility of the stink bug species Nezara viridula (L.), Nezara antennata Scott, Piezodorus hybneri (Gmelin), and Riptortus pedestris (F.) to insecticides was tested, establishing their 50% lethal dose (LD50) values as baseline data. Third instars and adults of the four species were treated by topical application with seven insecticides: fenitrothion, fenthion, etofenprox, silafluofen, dinotefuran, clothianidin, and ethiprole. The weight of the stink bug and weight of the insecticide applied to each bug were used as explanatory variables in the probit regression analysis. The effect of the body weight on the dose-response relationship, the proportional model, was not uniform among the tested insecticide-stink bug combinations. However, the basic model fit all combinations and could estimate LD50 values successfully. Therefore, LD50 values at the medium (average) weight estimated by the basic model were selected to describe the susceptibility of the stink bugs. The LD50 value of silafluofen for N. viridula adults, and that of silafluofen and etofenprox for N. antennata adults, was at least 2,338 ng greater than the other species exposed to each insecticide. Almost all of the LD50 values for adults were over 10 times greater than those of the same species' nymphs treated with the same insecticide. Thus monitoring of occurring species and their developmental stages is important for controlling effectively the stink bug pest complex by insecticides, especially by silafluofen or etofenprox. The estimated LD50 values can be used as baseline data to compare the susceptibility of the species collected in another year or location.

  18. Toxicological Evaluation of Tetrameles nudiflora Methanolic Extract

    Directory of Open Access Journals (Sweden)

    Sofna DS Banjarnahor

    2015-01-01

    Full Text Available Exploration of Mekongga national park resulted in novel finding of anticancer property from Tetrameles nudiflora. The investigation of toxic features of T. nudiflora is vital for further studies of its pharmacological activities. Acute toxicity test was done on methanolic extracts of T. nudiflora in DDY mice. Animal models were ordered into five groups. Group 1 was given 1 ml solution of 2.5% Tween 80 in a sole oral dose. The remaining groups were appointed a sole dose of 1, 2, 4 and 8 g/kg body weight T. nudiflora, respectively. Toxic effects of the extract were evaluated on the basis of behavioral observations in the form of locomotor activity; curiosity; defecation; urination and also animal mortality. Observations were carried out for 14 days. No significant changes in body weight and behavioral activities were recorded. Mortality was recorded up to 22% of the male group, and 11% of the female group. The T. nudiflora extracts tested for toxicity against brine shrimp had 50% lethal concentration (LC50 values of 46.67 μg/ml. It can be concluded that methanol extracts of T. nudiflora are potential to be explored as anticancer (LC50= 46.67 μg/ml. The extract is slightly toxic in male mice with Lethal Dose 50 (LD50 12.6 g/kg body weight, and practically nontoxic for female (LD50>15 g/kg body weight

  19. Chloroquine Improves Survival and Hematopoietic Recovery After Lethal Low-Dose-Rate Radiation

    International Nuclear Information System (INIS)

    Lim Yiting; Hedayati, Mohammad; Merchant, Akil A.; Zhang Yonggang; Yu, Hsiang-Hsuan M.; Kastan, Michael B.; Matsui, William; DeWeese, Theodore L.

    2012-01-01

    Purpose: We have previously shown that the antimalarial agent chloroquine can abrogate the lethal cellular effects of low-dose-rate (LDR) radiation in vitro, most likely by activating the ataxia-telangiectasia mutated (ATM) protein. Here, we demonstrate that chloroquine treatment also protects against lethal doses of LDR radiation in vivo. Methods and Materials: C57BL/6 mice were irradiated with a total of 12.8 Gy delivered at 9.4 cGy/hour. ATM null mice from the same background were used to determine the influence of ATM. Chloroquine was administered by two intraperitoneal injections of 59.4 μg per 17 g of body weight, 24 hours and 4 hours before irradiation. Bone marrow cells isolated from tibia, fibula, and vertebral bones were transplanted into lethally irradiated CD45 congenic recipient mice by retroorbital injection. Chimerism was assessed by flow cytometry. In vitro methylcellulose colony-forming assay of whole bone marrow cells and fluorescence activated cell sorting analysis of lineage depleted cells were used to assess the effect of chloroquine on progenitor cells. Results: Mice pretreated with chloroquine before radiation exhibited a significantly higher survival rate than did mice treated with radiation alone (80% vs. 31%, p = 0.0026). Chloroquine administration before radiation did not affect the survival of ATM null mice (p = 0.86). Chloroquine also had a significant effect on the early engraftment of bone marrow cells from the irradiated donor mice 6 weeks after transplantation (4.2% vs. 0.4%, p = 0.015). Conclusion: Chloroquine administration before radiation had a significant effect on the survival of normal but not ATM null mice, strongly suggesting that the in vivo effect, like the in vitro effect, is also ATM dependent. Chloroquine improved the early engraftment of bone marrow cells from LDR-irradiated mice, presumably by protecting the progenitor cells from radiation injury. Chloroquine thus could serve as a very useful drug for protection

  20. Effects of lethal dose of γ-irradiation on intestinal enzymes of the pigeons Columba livia intermedia Strickland

    International Nuclear Information System (INIS)

    Gadhia, P.K.

    1979-01-01

    Effect of γ-irradiation with lethal dose (1000 rads) on alkaline phosphatase and glucose-6-phosphatase have been studied in two different regions (duodenum and ileum) of small intestine of pigeons. The enzymes were studied at different intervals like 2, 4, 6 and 8 days after irradiation. The sp. activities of enzyme increased significantly both in duodenum and ileum. However, significant increase in alkaline phosphatase and glucose-6-phosphatase were observed at the 2nd and the 4th days post-irradiation respectively. The increase in enzyme activities may present de novo synthesis of these enzymes after lethal dose of irradiation. The histologic picture revealed that after the 4th day of irradiation, the number of goblet cells increased and after the 6th day crypt-villus system was destroyed completely as compared to sham-irradiated pigeons. (author)

  1. Effects of lethal dose of. gamma. -irradiation on intestinal enzymes of the pigeons Columba livia intermedia Strickland

    Energy Technology Data Exchange (ETDEWEB)

    Gadhia, P.K. (South Gujarat Univ., Surat (India). Dept. of Biosciences); Shah, V.C. (Gujarat Univ. School of Sciences, Ahmedabad (India))

    1979-09-01

    Effect of ..gamma..-irradiation with lethal dose (1000 rads) on alkaline phosphatase and glucose-6-phosphatase have been studied in two different regions (duodenum and ileum) of small intestine of pigeons. The enzymes were studied at different intervals like 2, 4, 6 and 8 days after irradiation. The sp. activities of enzyme increased significantly both in duodenum and ileum. However, significant increase in alkaline phosphatase and glucose-6-phosphatase were observed at the 2nd and the 4th days post-irradiation respectively. The increase in enzyme activities may present de novo synthesis of these enzymes after lethal dose of irradiation. The histologic picture revealed that after the 4th day of irradiation, the number of goblet cells increased and after the 6th day crypt-villus system was destroyed completely as compared to sham-irradiated pigeons.

  2. Dose and time-dependent effects of cyanide on thiosulfate sulfurtransferase, 3-mercaptopyruvate sulfurtransferase, and cystathionine λ-lyase activities.

    Science.gov (United States)

    Singh, Poonam; Rao, Pooja; Bhattacharya, Rahul

    2013-12-01

    We assessed the dose-dependent effect of potassium cyanide (KCN) on thiosulfate sulfurtransferase (TST), 3-mercaptopyruvate sulfurtransferase (3-MPST), and cystathionine λ-lyase (CST) activities in mice. The time-dependent effect of 0.5 LD50 KCN on cyanide level and cytochrome c oxidase (CCO), TST, 3-MPST, and CST activities was also examined. Furthermore, TST, 3-MPST, and CST activities were measured in stored mice cadavers. Hepatic and renal TST activity increased by 0.5 LD50 KCN but diminished by ≥2.0 LD50. After 0.5 LD50 KCN, the elevated hepatic cyanide level was accompanied by increased TST, 3-MPST, and CST activities, and CCO inhibition. Elevated renal cyanide level was only accompanied by increased 3-MPST activity. No appreciable change in enzyme activities was observed in mice cadavers. The study concludes that high doses of cyanide exert saturating effects on its detoxification enzymes, indicating their exogenous use during cyanide poisoning. Also, these enzymes are not reliable markers of cyanide poisoning in autopsied samples. © 2013 Wiley Periodicals, Inc.

  3. Chick embryo chorioallantoic membrane (CAM): an alternative predictive model in acute toxicological studies for anti-cancer drugs.

    Science.gov (United States)

    Kue, Chin Siang; Tan, Kae Yi; Lam, May Lynn; Lee, Hong Boon

    2015-01-01

    The chick embryo chorioallantoic membrane (CAM) is a preclinical model widely used for vascular and anti-vascular effects of therapeutic agents in vivo. In this study, we examine the suitability of CAM as a predictive model for acute toxicology studies of drugs by comparing it to conventional mouse and rat models for 10 FDA-approved anticancer drugs (paclitaxel, carmustine, camptothecin, cyclophosphamide, vincristine, cisplatin, aloin, mitomycin C, actinomycin-D, melphalan). Suitable formulations for intravenous administration were determined before the average of median lethal dose (LD50) and median survival dose (SD(50)) in the CAM were measured and calculated for these drugs. The resultant ideal LD(50) values were correlated to those reported in the literature using Pearson's correlation test for both intravenous and intraperitoneal routes of injection in rodents. Our results showed moderate correlations (r(2)=0.42 - 0.68, PLD(50) values obtained using the CAM model with LD(50) values from mice and rats models for both intravenous and intraperitoneal administrations, suggesting that the chick embryo may be a suitable alternative model for acute drug toxicity screening before embarking on full toxicological investigations in rodents in development of anticancer drugs.

  4. Experimental prophylaxis and therapy of radiation damage by newly synthesized S-heteryl mercaptoalkyl N-aryl hydrazidimides

    Energy Technology Data Exchange (ETDEWEB)

    Pantev, T P

    1975-01-01

    The synthesis is described of representatives of a new class of potential antiradiation agents, the S-heteryl mercaptoalkyl N-aryl hydrazidimices (MHA), obtained by molecular combination of three basic groups of radioprotectors. Toxicity characteristics (LD/sub 100/, LD/sub 50/, and maximum tolerable doses) indicated the compounds tested to be no more toxic for mide and rats than most of the established radioprotective agents. Under acute X-irradiation conditions with minimum absolutely lethal doses, 6 out of the 14 compounds tested showed clear-cut protective properties in mice. These 6 compounds also raised by 20 to 50% the survival of lethally irradiated rats. The most effective preparation was Y-64 (S-2-benzimidazolyl mercaptopropio N-p-tolyl hydrazidimide). This compound is observed to protect hematopoietic tissue in mice (Dose Reduction Factor of 1.29) and rats (Dose Reduction Factor of 1.52) given X-ray doses in the range of 400 to 900 R. With acute gamma irradiation, Y-64, as well as cysteamine, ensured survival of a larger amount of hematopoietic stem cells in bone marrow (using exogenous spleen colony techniques) and a more rapid recovery rate of the stem cell pool. With fractionated X-rays (5 x 100 R daily), Y-64 failed to increase survival, showing, nevertheless, a favorable effect on hematopoietic indices. When administered postradiation, Y-64 failed to influence the course of acute radiation disease in lethally irradiated mice; but, reducing hematopoietic damage, it raised by 40% the survival of lethally irradiated rats. No effect was observed with Y-64 post treatment following either fractionated irradiation (15 x 100 R daily) given to rats or prolonged gamma irradiation (0.28 R/min) to mice. The studies shed light on the mechanism of action of MHA.

  5. Incidence of lactase deficiency (LD) in gastroduodenal ulcer and gastric carcinoma

    International Nuclear Information System (INIS)

    Bahk, Yong Whee; Ahn, Kwan Shik; Kim, Chung Ja

    1974-01-01

    Lactase deficiency (LD) has been described in associated with peptic ulcer disease of the upper gastrointestinal tract, but little has been known as to the incidence of LD in the patients with ulcer disease of the upper GI tract or with gastric carcinoma. The purpose of the present study is to investigate the incidence of LD in gastric and/or duodenal ulcer disease and in gastric carcinoma, and to hypothesize the possible effect of these diseases on LD. Clinical materials consisted of 40 cases of active duodenal ulcer disease, 19 cases of benign gastric ulcer, 5 cases of multiple ulcers both in the stomach and duodenum, and 32 cases of gastric carcinoma. We used the lactose-barium test in diagnosing LD. X-ray findings were assessed according to the criteria described by Laws et al. and Preger and Amberg in the small-bowel film obtained at 30 minutes after the ingestion of some 200 ml of lactose-barium meal which contained 50 gm of lactose. Our clinical study revealed that the incidence of LD in duodenal ulcer was 50%, in gastric ulcer 57.9%, in gastric and duodenal ulcer 60%, and in gastric carcinoma 46.9%. The difference of incidence between each disease were statistically not significant, but the difference between the disease group and normal control was highly significant. The incidence of LD in disease group was nearly twice as high as that of normal control (27.7%). It is speculated that high incidence of LD in peptic ulcer disease of upper GI tract in particular may be associated with high acidity, the analog of which is found in Zollinger-Ellison syndrome. But high acidity is not a prominent feature in gastric carcinoma which is attended by almost equally high incidence of LD. It is therefore likely that the intolerability to lactose is caused by much complicated mechanism of versatile factors

  6. Incidence of lactase deficiency (LD) in gastroduodenal ulcer and gastric carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yong Whee; Ahn, Kwan Shik; Kim, Chung Ja [St. Mary' s Hospital, Catholic Medical College, Seoul (Korea, Republic of)

    1974-04-15

    Lactase deficiency (LD) has been described in associated with peptic ulcer disease of the upper gastrointestinal tract, but little has been known as to the incidence of LD in the patients with ulcer disease of the upper GI tract or with gastric carcinoma. The purpose of the present study is to investigate the incidence of LD in gastric and/or duodenal ulcer disease and in gastric carcinoma, and to hypothesize the possible effect of these diseases on LD. Clinical materials consisted of 40 cases of active duodenal ulcer disease, 19 cases of benign gastric ulcer, 5 cases of multiple ulcers both in the stomach and duodenum, and 32 cases of gastric carcinoma. We used the lactose-barium test in diagnosing LD. X-ray findings were assessed according to the criteria described by Laws et al. and Preger and Amberg in the small-bowel film obtained at 30 minutes after the ingestion of some 200 ml of lactose-barium meal which contained 50 gm of lactose. Our clinical study revealed that the incidence of LD in duodenal ulcer was 50%, in gastric ulcer 57.9%, in gastric and duodenal ulcer 60%, and in gastric carcinoma 46.9%. The difference of incidence between each disease were statistically not significant, but the difference between the disease group and normal control was highly significant. The incidence of LD in disease group was nearly twice as high as that of normal control (27.7%). It is speculated that high incidence of LD in peptic ulcer disease of upper GI tract in particular may be associated with high acidity, the analog of which is found in Zollinger-Ellison syndrome. But high acidity is not a prominent feature in gastric carcinoma which is attended by almost equally high incidence of LD. It is therefore likely that the intolerability to lactose is caused by much complicated mechanism of versatile factors.

  7. LC and LD50 values of Bacillus thuringiensis Serovar japonensis strain buibui toxin to Oriental beetle and northern masked chafer larvae (Coleoptera: Scarabaeidae).

    Science.gov (United States)

    Mashtoly, Tamer A; El-Zemaity, Mohamed El-Said; Hussien, Mohamed I; Alm, Steven R

    2009-10-01

    Bacillus thuringiensis serovar japonensis strain Buibui has the potential to be an important control agent for pest scarabs. Bioassays were designed to test B. t. japonensis against two of the major turf and ornamental scarab pests infesting turfgrasses and ornamentals and to serve as a basis for further tests against other scarab pests. LC and LD50 values of B. t. serovarjaponensis strain Buibui toxin and spores were determined by four different bioassays for the oriental beetle, Anomala orientalis (Waterhouse), and northern masked chafer, Cyclocephala borealis Arrow. Oriental beetle larvae were bioassayed in autoclaved and nonautoclaved soil from where they were collected (Kingston, RI [native]), in nonautoclaved soil from where the northern masked chafer larvae were collected (Groton, CT [foreign]), and per os. Northern masked chafer larvae were bioassayed in autoclaved and nonautoclaved soil from where they were collected (Groton, CT [native]), in nonautoclaved soil from where the oriental beetle larvae were collected (Kingston, RI [foreign]) and per os. LC50 values of 3.93 microg toxin/g autoclaved native soil, 1.80 microg toxin/g nonautoclaved native soil, and 0.42 microg toxin/g nonautoclaved foreign soil and an LD50 value of 0.41 microg per os were determined at 14 d forA. orientalis. LC50 values of 588.28 microg toxin/g autoclaved native soil, 155.10 microg toxin/g nonautoclaved native soil, 265.32 microg toxin/g nonautoclaved foreign soil, and LD50 of 5.21 microg per os were determined at 14 d (soils) and 10 d (per os) for C. borealis. There were significant differences in LC50 values for oriental beetles in autoclaved, nonautoclaved native soil and nonautoclaved foreign soil. There were significant differences in LCo values for northern masked chafers in autoclaved and nonautoclaved native soil. B. t. japonensis can be applied now for control of oriental beetles at rates that are economically competitive with synthetic chemicals. If we can determine the

  8. Studying the ability of mutation and selection of promising lines of Brassia verrucosa Lindl. by gamma Irradiation in combination with In-Vitro technique

    International Nuclear Information System (INIS)

    Le Thi Thuy Linh; Le Van Thuc; Dang Thi Dien; Han Huynh Dien; Le Thi Bich Thy

    2015-01-01

    Mutation research by gamma irradiation is an effective technique in producing new plant breeding. In this study, we optimized some elements on the propagation process of Warty Brassia (Brassia verrucosa Lindl.) in vitro; determination of lethal dose (LD50) of Warty Brassia bud clusters in vitro; initial evaluating of gamma irradiation effects on the morphology of Warty Brassia in vitro. The results showed that, the appropriate medium for meristem-tip culture was on VW medium (Vacin and Went, 1949) containing 1 g/l activated charcoal (AC), 10% coconut water (CW), 50 g/l potato and 20 g/l sucrose; medium for in vitro shoot multiplication was on VW medium supplemented with 0.5 mg/l NAA, 0.3 mg/l BA, 1 g/l AC, 10% CW, 50 g/l potato and 20 g/l sucrose; medium for in vitro root induction was on VW medium supplemented with 0.5 mg/l NAA, 1 g/l AC, 10% CW, 50 g/l potato and 20 g/l sucrose. The plantlets were acclimatized and transplanted to 50% sphagnum moss and 50% coconut fiber, the survival rate was 94.7%; the LD50 values were in the range of 40 - 50 Gy; the stimulation dose was 10 Gy; the highest variation rate was on the dose of 40 Gy; the absolute lethal dose was 80 Gy. 6 variations of Warty Brassia in vitro were obtained including the variant of morphology, structure and diameter of pseudo-bulb were very difference comparing to control. The following study are evaluating of the growth and the phenotypic changing of potential variant types of Warty Brassia in green house. (author)

  9. Optimization of antiscorpion venom production

    Directory of Open Access Journals (Sweden)

    O. Ozkan

    2006-01-01

    Full Text Available The present study was carried out to produce highly efficient antivenom from a small number of telsons in a short time. Venom solution was prepared through maceration of telsons from Androctonus crassicauda (Olivier, 1807 collected in the Southeastern Anatolia Region, Turkey. Lethal dose 50% (LD50 of the venom solution injected into mice was 1 ml/kg (95% confidence interval; 0.8-1.3, according to probit analysis. Different adjuvants (Freund's Complete Adjuvant, Freund's Incomplete Adjuvant, and 0.4% aluminium phosphate, at increasing doses and combined with venom, were subcutaneously injected into horses on days 0, 14, 21, 28, 35, and 42 of the experiment. Antivenom was collected from the immunized horses on days 45, 48, and 51 using the pepsin digestive method. The antivenom effective dose 50% (ED50 in mice was 0.5 ml (95% confidence interval; 0.40-0.58, according to probit analysis. It was concluded that 0.5 ml antivenom neutralized a venom dose 35-fold higher than the venom LD50. Thus, highly potent antivenom could be produced from about 238 telsons in 51 days.

  10. Effect of radiosterilization of some antihistamines on their toxicity

    International Nuclear Information System (INIS)

    El-Sayed, M.E.; Roushdy, H.M.; Naiema, M.; Seham, H.M.H.

    1985-01-01

    The effect of gamma irradiation of pgeniramine maleate and menhydrinate solutions at the radiation levels of 15,25 and 50KGY on their toxicity has been investigated. Irradiation of pheniramine maleate and dimenhydrinate solutions at dose levels of 15,25 and 50KGY resulted in no significant change in neither the gross toxicity of the two drugs nor in their LD 50's on rats. Pheniramine maleate and dimenhydrinate whether irradiated or not, resulted in no significant increase in serum GPT or alkaline phosphatase activities when given at a dose of 15mg/Kg suggesting no significant alteration to liver function in rats. Higher doses of the two antihistaminics, namely, the minimal lethal doses and the LD 50's induced hydropic degeneration of liver cells, lymphocytic infiltration of the portal tract and focal areas of necrosis of hepatic cells mostly in the central lobule. Fatty infiltration was observed with dimenhydrinate. Radiation treatment of those antihistamines up to 50KGY resulting in no alteration in their toxicity projects the high radiation stability of pheniramine maleate and dimenhydrinate and confirms gamma irradiation is a successful method for their sterilization

  11. Modification of damage following low doses

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  12. Induction of P450 genes in Nilaparvata lugens and Sogatella furcifera by two neonicotinoid insecticides.

    Science.gov (United States)

    Yang, Yuan-Xue; Yu, Na; Zhang, Jian-Hua; Zhang, Yi-Xi; Liu, Ze-Wen

    2018-06-01

    Nilaparvata lugens and Sogatella furcifera are two primary planthoppers on rice throughout Asian countries and areas. Neonicotinoid insecticides, such as imidacloprid (IMI), have been extensively used to control rice planthoppers and IMI resistance consequently occurred with an important mechanism from the over-expression of P450 genes. The induction of P450 genes by IMI may increase the ability to metabolize this insecticide in planthoppers and increase the resistance risk. In this study, the induction of P450 genes was compared in S. furcifera treated with IMI and nitromethyleneimidazole (NMI), in two planthopper species by IMI lethal dose that kills 85% of the population (LD 85 ), and in N. lugens among three IMI doses (LD 15 , LD 50 and LD 85 ). When IMI and NMI at the LD 85 dose were applied to S. furcifera, the expression changes in most P450 genes were similar, including the up-regulation of nine genes and down-regulation of three genes. In terms of the expression changes in 12 homologous P450 genes between N. lugens and S. furcifera treated with IMI at the LD 85 dose, 10 genes had very similar patterns, such as up-regulation in seven genes, down-regulation in one gene and no significant changes in two genes. When three different IMI doses were applied to N. lugens, the changes in P450 gene expression were much different, such as up-regulation in four genes at all doses and dose-dependent regulation of the other nine genes. For example, CYP6AY1 could be induced by all IMI doses, while CYP6ER1 was only up-regulated by the LD 50 dose, although both genes were reported important in IMI resistance. In conclusion, P450 genes in two planthopper species showed similar regulation patterns in responding to IMI, and the two neonicotinoid insecticides had similar effects on P450 gene expression, although the regulation was often dose-dependent. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  13. Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms

    Directory of Open Access Journals (Sweden)

    Eduardo Sánchez

    2016-01-01

    Full Text Available Biofilm is a complex microbial community highly resistant to antimicrobials. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms. Preliminary screening by diffusion well assay showed the antimicrobial activity of Prosopis laevigata, Opuntia ficus-indica, and Gutierrezia microcephala. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF was evaluated before and after the addition of plant extracts (MBC × 0.75. Opuntia ficus-indica caused the major reduction on SBF in dose-dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salina L.. Lethal Dose concentration (LD50 values of the plant extracts was calculated. LD50 values for P. laevigata and G. microcephala were 141.6 and 323.3 µg/mL, respectively, while O. ficus-indica showed a slight lethality with 939.2 µg/mL. Phytochemical analyses reveal the presence of flavonoids, tannins, and coumarines.

  14. Toxicity and hazard of vanadium to mallard ducks (Anas platyrhynchos) and Canada geese (Branta canadensis)

    Science.gov (United States)

    Rattner, Barnett A.; McKernan, Moira A.; Eisenreich, Karen M.; Link, William A.; Olsen, Glenn H.; Hoffman, David J.; Knowles, K.A.; McGowan, Peter C.

    2006-01-01

    A recent Canada goose (Branta canadensis) die-off at a petroleum refinery fly ash pond in Delaware was attributed to vanadium (V) toxicity. Because of the paucity of V toxicity data for wild birds, a series of studies was undertaken using the forms of V believed to have resulted in this incident. In 7-d single oral dose trials with mallard drakes (Anas platyrhynchos), the estimated median lethal dose (LD50) for vanadium pentoxide was 113 mg/kg body weight, while the LD50 for sodium metavanadate was 75.5 mg/kg. Sodium metavanadate was found to be even more potent (LD50 = 37.2 mg/kg) in male Canada geese. The most distinctive histopathological lesion of both forms of V was lympho-granulocytic enteritis with hemorrhage into the intestinal lumen. Vanadium accumulation in liver and kidney was proportional to the administered dose, and predictive analyses based on these data suggest that V concentrations of 10 μg/g dry weight (dw) in liver and 25 μg/g dw in kidney are associated with mortality (>90% confidence that exposure is >LD50) in mallards acutely exposed to sodium metavanadate. Chronic exposure to increasing dietary concentrations of sodium metavanadate (38.5 to 2651 ppm) over 67 d resulted in V accumulation in liver and kidney (25.2 and 13.6 μg/g dw, respectively), mild intestinal hemorrhage, blood chemistry changes, and evidence of hepatic oxidative stress in mallards, although some of these responses may have been confounded by food avoidance and weight loss. Dietary exposure of mallards to 250 ppm sodium metavanadate for 4 wk resulted in modest accumulation of V in liver and kidney (<5 μg/g dw) and mild intestinal hemorrhage. Based on these data and other observations, it is unlikely that chronic low-level dietary exposure to V poses a direct lethal hazard to wildlife. However, point sources, such as the V-laden fly ash pond encountered by geese at the petroleum refinery in Delaware, may pose a significant hazard to water birds.

  15. Toxicity studies of drugs and chemicals in animals: An overview

    Directory of Open Access Journals (Sweden)

    S. Saganuwan

    2017-12-01

    Full Text Available Toxicity study is the investigation of either short or long-term toxic effects of a drug or chemical on animals. The toxicity is dose-dependent as asserted by Paracelsus over 500 years ago. However, short-term toxic effect is determined using median lethal dose (LD50 first introduced by Trevan in 1927 and revised many times. Presently there is a growing preponderance of rejection of scientific papers on acute toxicity study, simply because of the belief that in the current hazard and safety as-sessment of drugs and chemicals, LD50 values are no longer used. In view of this, literature search was carried out with a view to investigating the relevance of LD50 in development and assessment of drugs and chemicals. The findings revealed that in the past, many animals had been used for LD50 determination. OECD has reduced the number of test animals to 5–15 and presently it is further re-duced to 2–6. Acute toxicity study is being carried out in medicinal plants research and in the study of patent medicine. Although the application of LD50 has been drastically reduced, it is still applied and accepted in some parts of the world. Moreover, animals on which LD50 tests are conducted, should be allowed to die to see the end effect of the test drug or chemical because euthanisia of test animals may mask some toxicity signs of the test agents. Therefore, toxicity study of drugs and chemicals is a sci-entific process necessary for discovery and development of drugs as well as identification of potential toxicants.

  16. Ornithogalum virens as a plant assay for beta and gamma radiation effects

    International Nuclear Information System (INIS)

    Herron, V.J.

    1979-01-01

    The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute ( 60 Co) and chronic ( 137 Cs) gamma radiation and internal beta radiation ( 32 P), lethality (LD 50 , LD 100 ), growth inhibition, and chromosome aberrations were investigated. The LD 50 and LD 100 for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation

  17. Evaluation of the Insecticidal Efficacy of Wild Type and Recombinant Baculoviruses.

    Science.gov (United States)

    Popham, Holly J R; Ellersieck, Mark R; Li, Huarong; Bonning, Bryony C

    2016-01-01

    A considerable amount of work has been undertaken to genetically enhance the efficacy of baculovirus insecticides. Following construction of a genetically altered baculovirus, laboratory bioassays are used to quantify various parameters of insecticidal activity such as the median lethal concentration (or dose) required to kill 50 % of infected larvae (LC50 or LD50), median survival of larvae infected (ST50), and feeding damage incurred by infected larvae. In this chapter, protocols are described for a variety of bioassays and the corresponding data analyses for assessment of the insecticidal activity of baculovirus insecticides.

  18. Toxicity studies of drugs and chemicals in animals: An overview

    OpenAIRE

    S. Saganuwan

    2017-01-01

    Toxicity study is the investigation of either short or long-term toxic effects of a drug or chemical on animals. The toxicity is dose-dependent as asserted by Paracelsus over 500 years ago. However, short-term toxic effect is determined using median lethal dose (LD50) first introduced by Trevan in 1927 and revised many times. Presently there is a growing preponderance of rejection of scientific papers on acute toxicity study, simply because of the belief that in the current hazard and safety ...

  19. Orientation of streptococcus agalactiae irradiation dose for subclinical mastitis vaccine in dairy cows

    International Nuclear Information System (INIS)

    Tuasikal, B.J.; Estuningsih, S.; Pasaribu, F.H.; Wibawan, I.W.T.

    2012-01-01

    An experiment to determine the effect of gamma-ray irradiation in debilitating Streptococcus agalactiae as a cause of subclinical mastitis (inflammation of the udder) in cows has been conducted. S. agalactiae bacteria was isolated from subclinical mastitis found in dairy cows in the field was then observed for its cell growth. The bacteria which have reached mid-log phase of growth, were divided into 5 treatment groups, of which each was irradiated at dose level of 0; 25; 50; 75; and 100Gy. Irradiated bacteria subsequently were grown on Brain Heart Infusion agar (BHI), and each of its colonies was counted for LD50 determination. The obtained curves from irradiated treatment bacterial shown viability percentage by the linier equation of Y = 95.414 e -0,0371X ; R 2 = 0.9979, while Y = % viability and X = dose of irradiation. The calculation done in this experiment shows that irradiation dose of 17.4 Gy weaken the bacteria pathogenicity of S. agalactiae to the level of LD 50 . (author)

  20. Toxicology Studies on Lewisite and Sulfur Mustard Agents: Modified Dominant Lethal Study of Sulfur Mustard in Rats Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sasser, L. B.; Cushing, J. A.; Kalkwarf, D. R.; Buschbom, R. L.

    1989-05-01

    Occupational health standards have not been established for sulfur mustard (HD) [bis{2-chloroethyl)-sulfide) ' a strong alkylating agent with known mutagenic properties. Little, however, is known about the mutagenic activity of HD in mammalian species and data regarding the dominant lethal effects of HD are ambiguous. The purpose of this study was to determine the dominant lethal effect in male and female rats orally exposed to HD. The study was conducted in two phases; a female dominant lethal phase and a male dominant lethal phase. Sprague-Dawley rats of each sex were administered 0.08, 0.20, or 0.50 mg/kg HD in sesame oil 5 days/week for 10 weeks. For the female phase, treated or untreated males were mated with treated females and their fetuses were evaluated at approximately 14 days after copulation. For the male dominant lethal phase, treated males cohabited with untreated femal (during 5 days of each week for 10 weeks) and females were sacrificed for fetal evaluation 14 days after the midweek of cohabitation during each of the 10 weeks. The appearance and behavior of the rats were unremarkable throughout the experiment and there were no treatment-related deaths. Growth rates were reduced in both female and male rats treated with 0.50 mg/kg HD. Indicators of reproductive performance did not demonstrate significant female dominant lethal effects, although significant male dominant lethal effects were observed at 2 and 3 week post-exposure. These effects included increases of early fetal resorptions and preimplantation losses and decreases of total live embryo implants. These effects were most consistently observed at a dose of 0.50 mg/kg, but frequently occurred at the lower doses. Although no treatment-related effects on male reproductive organ weights or sperm motility were found, a significant increase in the percentage of abnormal sperm was detected in males exposed to 0. 50 mg/kg HD. The timing of these effects is consistent with an effect during the

  1. Modification of radiation induced genetic damage and impaired DNA synthesis by thiourea treatment in Solanum incanum L

    International Nuclear Information System (INIS)

    Kumar, Girish

    1991-01-01

    Modification of induced genetic damage after exposure to LD 50 and LD 90 doses of 60 Co gamma-irradiation on dormant seeds of Solanum incanum L. by pre- and post-treatments of thiourea was investigated. Thiourea pre-treatment reduced cellular lesions, growth injury and the death of seedlings, while post-treatment increased lethality. Incorporation of 3 H-tymidine into DNA fraction gradually increased with 10 -4 to 10 -2 M thiourea treatment when applied before irradiation. Post-treatment of the thiourea, on the other hand, not only showed poor labelling of DNA but also delayed its synthesis. (author)

  2. TOXICOLOGICAL STUDIES ON MALACHITE GREEN - A TRIPHENYLMETHANE DYE

    DEFF Research Database (Denmark)

    Cleinmensen, Steen; Jensen, Jørn C.; Jensen, Niels J.

    1984-01-01

    The oral LD50 for malachite green oxalate was found to be 275 mg/kg in rats while the approximate lethal dose for NMRI mice was 50 mg/kg. No systemic effects were seen after dermal application of 2,000 mg/kg. Repeated administration in the diet for 28 days to rats produced only minor changes...... in serum urea and aspartate aminotransferase levels. The rats at the highest dose level showed decreased weight gain and appeared clinically to have elevated motor activity. No sex differences were observed in either acute or prolonged experiments. In accord with human experience malachite green...

  3. Enhancement of Hsp70 synthesis protects common carp, Cyprinus carpio L., against lethal ammonia toxicity.

    Science.gov (United States)

    Sung, Y Y; Roberts, R J; Bossier, P

    2012-08-01

    Exposure to TEX-OE®, a patented extract of the prickly pear cactus (Opuntia ficus indica) containing chaperone-stimulating factor, was shown to protect common carp, Cyprinus carpio L., fingerlings against acute ammonia stress. Survival was enhanced twofold from 50% to 95% after exposure to 5.92 mg L(-1) NH(3) , a level determined in the ammonia challenge bioassay as the 1-h LD50 concentration for this species. Survival of TEX-OE®-pre-exposed fish was enhanced by 20% over non-exposed controls during lethal ammonia challenge (14.21 mg L(-1)  NH(3) ). Increase in the levels of gill and muscle Hsp70 was evident in TEX-OE®-pre-exposed fish but not in the unexposed controls, indicating that application of TEX-OE® accelerated carp endogenous Hsp70 synthesis during ammonia perturbation. Protection against ammonia was correlated with Hsp70 accretion. © 2012 Blackwell Publishing Ltd.

  4. Near-term and late biological effects of acute and low-dose-rate continuous gamma-ray exposure in dogs and monkeys

    International Nuclear Information System (INIS)

    Spalding, J.F.; Holland, L.M.

    1979-07-01

    Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (inury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with gamma rays at 35 r/day until death to determine the amount of radiation-induced injry remaining in conditioned animals as a reduction in mean survival time. Dogs (50%) and monkeys (8%) died from injury incurred during conditioning exposures. Thus, the comparative response (in terms of lethality) of dogs and monkeys to dose protraction by acute dose fractionation was similar to what we would expect from a single acute dose. The mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approx. 1400 h). Thus, the hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35-R/day gamma-ray challenge exposure were greater (significant in dogs but not in monkeys) than for their control counterparts. Thus, long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than 4 times the acute LD 50 30 in dogs and approximately 2 times that in monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 Rat/day

  5. Academic procrastination and feelings toward procrastination in LD and non-LD students: Preliminary insights for future intervention.

    Science.gov (United States)

    Hen, Meirav

    2018-01-01

    Academic procrastination is a prevalent behavior that negatively influences students' performance and well-being. The growing number of students with learning disabilities (LD) in higher education communities leads to the need to study and address academic procrastination in this unique population of students and to develop ways to prevent and intervene. The present study examined the difference in academic procrastination between LD, non-LD, and supported LD college students in Israel. Findings indicated a significant difference between the three groups, both in academic procrastination and in the desire to change this behavior. Interestingly, supported LD students were similar to non-LD students in all parameters of academic procrastination; however, they expressed less desire to change this behavior than unsupported LD students. These findings highlight the effect of general academic support on academic procrastination in LD students. Future studies will need to further explore the specific elements of support that most contribute to the reduction of academic procrastination in LD students. Specific support programs for academic procrastination in LD students who take into account the findings of these future studies can then be developed and studied.

  6. Evidence for a decreased susceptibility to acute radiation lethality in young lambs

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, P B [Department of Scientific and Industrial Research, Lower Hutt (New Zealand). Inst. of Nuclear Sciences; Pfeffer, A T [Ministry of Agriculture and Fisheries, Upper Hutt (New Zealand). Wallaceville Animal Research Centre

    1980-08-01

    The survival of 2- to 4-day old Romney-lambs was studied following bilateral /sup 60/Co irradiation at about 3.5 R/min (the exposure rate in air at the mid-line of the animal). Probit analysis of the data yielded an LDsub(50/60) of 900 R with 95% confidence limits of 700-1150 R. Mature sheep irradiated under similar conditions are known to have an LDsub(50/60) in the region of 250-350 R. These data indicate that very young lambs were less susceptible to radiation-induced hemopoietic failure than adults. Dorset Horn lambs and Romneys born by caesarian section also exhibited low susceptibility when irradiated at 2-4 days of age. There are few data available on LD/sub 50/ values for very young, large mammals (as opposed to rodents). Consideration must be given to the possibility that large mammals may be less sensitive to radiation-induced lethality shortly after birth than they are at maturity. Further work on the radiation response as a function of age after birth seems warranted and suggestions for some of the parameters which require investigation are made.

  7. The AFRRI TRIGA reactor: a summary of applications in mouse studies - 345

    International Nuclear Information System (INIS)

    Ledney, G.D.; Elliott, T.B.

    2010-01-01

    The AFRRI TRIGA reactor was used to simulate nuclear weapon mixed-field radiation injuries with and without additional tissue trauma. The severity of reactor-produced mixed-field radiations over that of γ-photon irradiation was evaluated in mice. Lethal doses (LDs) to 50% of groups of mice were determined for marrow cell (LD 50/30 , the dose required to kill 50% of the subjects within 30 days) and intestinal cell (LD 50/6 , the dose required to kill 50% of the subjects within 6 days) injury. As neutron (n) proportions in the total (t) radiation dose (D n /D t ) increased LD values decreased. Relative biological effectiveness (RBE) values for reactor-generated D n /D t used 60 Co γ photons and 250-kVp x-rays as reference standards. RBEs for irradiated mice increased as D n /D t increased and was further increased by wound trauma. Compared to γ-photon irradiation, mixed-field irradiation delayed wound closure times 25% to 50%. WR-151327 (200 mg/kg), a radioprotective chemical, injected i.p. into mice prior to either radiation quality alone or into combined injured mice increased 30-day survival and reduced susceptibility to challenge with Klebsiella pneumoniae. Protection against irradiation and resistance to bacterial challenge afforded by the WR compound was greater for γ-photon irradiation than for mixed-field irradiation. The TRIGA reactor can be used to simulate nuclear radiation-induced situations that include traumas or infections. Countermeasures for increasing survival after mixed-field irradiation may be more difficult than for γ-photon irradiated casualties. (authors)

  8. Allopurinol, indomethacin and riboflavin enhance radiation lethality in mice

    International Nuclear Information System (INIS)

    Floersheim, G.L.

    1994-01-01

    Two widely used drugs, allopurinol and indomethacin, and the vitamin riboflavin increased the response of mice to ionizing radiation. In mice a dose of 10.5 Gy of γ rays from a 60 Co source resulted in a dose-dependent shortening of survival times after pretreatment with the three agents, applied at doses which were well tolerated alone. When the dose dependency of these drugs on the influence on survival was tested, two response patterns emerged. Indomethacin (25 mg/kg) shifted the survival curve to the left and reduced the LD 50 from ∼6.5 Gy to ∼4.5 Gy. Allopurinol (100 mg/kg) diminished the survival rate to approximately 50% irrespective of the radiation dose (ranging from 0.75 to 6.0 Gy). A similar though less striking trend was seen with riboflavin (120 mg/kg), which reduced the survival rate to approximately 65% in the dose range from 3 to 6 Gy. Mortality in mice treated with allopurinol or riboflavin and irradiated with nonlethal exposures (from radiation alone) occurred within the first few days after irradiation, suggesting a different type of injury than is usually associated with radiation death. Although doses of the three drugs used clinically are clearly lower than those providing enhanced radioresponse in our experiments, subtle and nonovert injury caused by combined exposure to the drugs and radiation cannot be completely excluded. 31 refs., 4 figs., 5 tabs

  9. Modification of radiation sensitivity by salts of the metals beryllium and indium and the rare earths cerium, lanthanum and scandium

    International Nuclear Information System (INIS)

    Floersheim, G.L.

    1995-01-01

    The LD 50 of 46 salts of metals and rare earths (lanthanoids) was determined in mice. Half the LD 50 of the compounds was then combined with lethal radiation (10.5 Gy) and the modification of survival time was scored. Only the metals beryllium and indium and the rare earths cerium, lanthanum and scandium displayed activity in our assay. There were then tested at a wider range of lower doses and reduced survival time in a dose-dependent fashion. This appears to be compatible with enhancement of radiation sensitivity. The interaction of these metals and rare earths with radiation adds a new facet to their toxicological spectrum and, by enhancing radiation effects, may influence estimates of risk. On the other hand, radiosensitizing properties of the metals may be useful for further development of compounds to be used as adjuncts in specific situations of cancer radiotherapy. 31 refs., 1 fig., 1 tab

  10. Protective effect of WR-2823 in irradiated mice

    International Nuclear Information System (INIS)

    Milovanovicj, A.; Tanasijevicj, D.; Cvetkovicj, M.; Cjosicj, M.; Chizmicj, Z.

    1987-01-01

    A chemical compound named WR-2823 has been synthetised. The acute toxicity after IP application has been investigated and LD 50 estimated. The protective ability of the radioprotector has been investigated in mice with gamma rays of 60 Co, or at the origin of 252 Cf. High protective potency in mice, treated with lethal doses of gamma rays and neutrons have been estimated. (author) 8 refs.; 1 tab

  11. Perna perna (LINNAEUS, 1758) mussels irradiated by 60CO gamma rays cytotoxicity evaluation

    International Nuclear Information System (INIS)

    Martini, Gisela A.; Pusceddu, Fabio H.; Rogero, Sizue O.; Rogero, Jose Roberto

    2013-01-01

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to 60 Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  12. Perna perna (LINNAEUS, 1758) mussels irradiated by {sup 60}CO gamma rays cytotoxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Gisela A.; Pusceddu, Fabio H.; Rogero, Sizue O.; Rogero, Jose Roberto, E-mail: gisela.martini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to {sup 60}Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  13. Influence of vaccination with Bordetella pertussis cells on haemopoiesis in sublethally irradiated mice and their radiation lethality

    International Nuclear Information System (INIS)

    Kwiek, S.; Bitny-Szlachto, S.

    1978-01-01

    Post-irradiation lethality of CFW mice has turned out to be enhanced by vaccination with Bordetella pertussis cells 10 min., 48 hrs. prior or 48 hrs. after the exposure to X-rays. The sensitization factor was found to be 1.23, as it revealed by decrease of radiation LD 50 . Granulopoiesis and erythropoiesis proved to be stimulated by vaccination, in mice irradiated with 200 or 400 R but not in those after 600 R. Direct radiosensitivity of CFU was not altered by vaccination, but the subsequent loss of bone marrow stem cells was enhanced in vaccinated mice. On the other hand, endocolonization of spleens with bone marrow stem cells has turned out to be highly enhanced by the vaccine, resulting in confluent growth of colonies. This effect of the vaccine was not abolished by hydroxyurea given 15 min. or 1 hr. after vaccination. Enhanced post-irradiation lethality is considered to result from fall of the bone marrow stem cell pool below the level indispensable to ensure the post-irradiation recovery of the haemopoietic system. (author)

  14. Dose-response and histopathological study, with special attention to the hypophysis, of the differential effects of domoic acid on rats and mice.

    Science.gov (United States)

    Vieira, Andrés Crespo; Martínez, J Manuel Cifuentes; Pose, Roberto Bermúdez; Queijo, Álvaro Antelo; Posadas, Nuria Alemañ; López, Luis M Botana

    2015-05-01

    The effects of the neurotoxin domoic acid (DA) in the central nervous system of rodents (essentially rats and mice) after intraperitoneal administration have been profusely studied in the past. These observations have shown that the toxin induces similar symptoms and pathology in both species, but the lethality varies greatly. This article addresses the common and specific histopathological effects in rats and mice and the difference in sensitivity of these species to DA. Various sublethal and lethal doses were employed in mice (from 3 mg/kg to 8 mg/kg) to observe their neurotoxicity by using different histological techniques, and these results were compared with the pathological effects after the administration of LD50 in rats (2.5 mg/kg). Additionally we also detected the presence of this toxin in various tissues by means of immunohistochemistry. Our results showed that rats are more vulnerable than mice to the neurotoxic effects of DA after intraperitoneal inoculation: lethality was extremely high in rats and the toxin produced hippocampal damage in rats surviving the intoxication, while lesions were not observed in DA-inoculated mice. As for similarities between rats and mice, both displayed similar clinical signs and in both the toxin was detected in the hypophysis by immunohistochemistry, a brain region not reported to date as target of the toxin. © 2015 Wiley Periodicals, Inc.

  15. Determination of carcinogenic threshold limit values using the tumorigenic dose rate 50% (TD50)

    International Nuclear Information System (INIS)

    Bonvalot, Y.; Oudiz, A.; Hubert, P.; Abenhaim, L.

    1989-01-01

    The objective of the present study is to propose a simple procedure for the determination of Occupational Limit Values (OLVs) based on the TD 50 concept (Tumorigenic Dose Rate 50%). The TD 50 concept was introduced by Peto R. and al. to help classify chemical substances according to their carcinogenic potency. The TD 50 is that dose rate (in mg/KXg body weight/day) which, if administered chronically for the standard lifespan of the species will halve the probability of remaining tumorless throughout that period. Using TD 50 values available for 776 substances, the procedure presented here allows one to determine OLVs corresponding to a fixed excess risk. It is based on a mathematical high-to-low doses extrapolation of the TD 50 . OLVs obtained with this procedure are compared with currently available TLVs and other occupational guidelines. (author)

  16. Prediction of Acute Mammalian Toxicity Using QSAR Methods: A Case Study of Sulfur Mustard and Its Breakdown Products

    Directory of Open Access Journals (Sweden)

    John Wheeler

    2012-07-01

    Full Text Available Predicting toxicity quantitatively, using Quantitative Structure Activity Relationships (QSAR, has matured over recent years to the point that the predictions can be used to help identify missing comparison values in a substance’s database. In this manuscript we investigate using the lethal dose that kills fifty percent of a test population (the LD50 for determining relative toxicity of a number of substances. In general, the smaller the LD50 value, the more toxic the chemical, and the larger the LD50 value, the lower the toxicity. When systemic toxicity and other specific toxicity data are unavailable for the chemical(s of interest, during emergency responses, LD50 values may be employed to determine the relative toxicity of a series of chemicals. In the present study, a group of chemical warfare agents and their breakdown products have been evaluated using four available rat oral QSAR LD50 models. The QSAR analysis shows that the breakdown products of Sulfur Mustard (HD are predicted to be less toxic than the parent compound as well as other known breakdown products that have known toxicities. The QSAR estimated break down products LD50 values ranged from 299 mg/kg to 5,764 mg/kg. This evaluation allows for the ranking and toxicity estimation of compounds for which little toxicity information existed; thus leading to better risk decision making in the field.

  17. Use of ionizing radiations In vitro for the production of new varieties of flowers: Tiny rose

    International Nuclear Information System (INIS)

    Gonzalez J, J.; Cruz G, M.T.

    1993-01-01

    The miniature rose (Rosa Chinensis) is one of the ornamental plants with more potential in the International flower market. Its great propagation difficulty has impede the mass production. The aim of this work is to produce a new variety of miniature rose with optimal market characteristics using the biotechnology of irradiation of meristems In vitro to induce mutations in ornamental plants. As a first stage in this work, the micro propagation In vitro and the determination of lethal dose 50 (LD 50 ) were carried out. (Author)

  18. Lethal mutation of internal irradiation brown planthopper (Nilaparvita lugens Stal)

    International Nuclear Information System (INIS)

    Wahid, R.A.

    1988-01-01

    The moulting IVth of BPH nympha were irradiated internally with radiophosphorous 32-P 1 uCi/ml, 10 uCi/ml, 50 uCi/ml, 100 uCi/ml, and 500 uCi/ml concentrations respectivelly. An observation was carried out to determines heredity of hopper sterilities from the mating groups of R male x N female, R male x R female, and N male x R female. The 32-P concentration below of 50 uCi/ml seemed to be the substerile dose, however, the dominant lethal mutation has been visually shown by R male x R female F1 mating group. The hereditary lines of F1, F2, F3, and F4 of the hopper sterilities wich were indicated by the nympha hatch ability have some significant correlations (r1= -0.77, r2= -0.92, r3= -0.93 and r4= -0.85). Thus, the resesif lethal mutations visually showed by F3 and F4 from all of the 100 uCi/ml and 50 uCi/ml treated groups. (author). 10 refs, 2 figs, 2 tabs

  19. Dose-rate models for human survival after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1987-01-01

    This paper reviews new estimates of the LD 50 in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD 50 s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively

  20. Guava (Psidium guajava L) improvement using in vivo and in vitro induced mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Zamir, R. [Nuclear Institute for Food and Agriculture (NIFA), Peshawar (Pakistan); Ali, N.; Shah, S. Tariq; Mohammad, T. [N.W.F.P. Agricultural University Peshawar, Peshawar (Pakistan); Ahmad, J. [Center of Biotechnology, University of Peshawar, Peshawar (Pakistan)

    2009-05-15

    In-vitro mutagenesis followed by micropropagation via axillary bud proliferation in shoot tips of guava (Psidium guajava L.) cultivar Safeda was carried out. Shoot tips were irradiated with 15 to 90Gy gamma rays radiations using {sup 60}Co gamma cell source and cultured on MS medium containing 3.0% sucrose, BAP and glutamine. Shoots proliferation was observed 7 weeks after culture initiation. Higher shoot proliferation rates were recorded on MS medium supplemented with 1.0 mgL{sup -1} BAP and 250 mgL{sup -1} glutamine. Rooting was observed on half-strength MS medium supplemented with IAA and IBA. Radio sensitivity test was assessed by determining the percentage of shoot tips survival and shoot proliferation rates. The LD50 (The dose at which 50% of the population killed) was observed on 45 Gy. The doses above 75 Gy were found to be lethal to all explants. Similarly, seeds and bud woods of guava Cv. Safeda were exposed to gamma rays at 0.05 to 0.3 kGy and 20 to 100 Gy respectively using {sup 60}Co gamma source. The LD50 for seeds was determined at 0.19 kGy, and 0.3 kGy was found to be lethal. Seeds irradiated with low doses germinated earlier as compared to those which received higher doses of irradiation. The LD50 for surviving bud woods grafted on the rootstocks in the nursery was determined at 60 Gy. There was constant and continuous reduction in the survival rates of buds as the doses increased. The bud woods of guava Cv. Safeda were more radiosensitive than seeds of the same cultivar. The most favourable doses were established between 0.15 and 0.2 KGy and led to mutations such as: highest number of fruits (40), highest fruit size (59mm) and highest fruit weight of (128.38g). The highest number of seeds (300) and 100 seed-weight (2.29g) were recorded at 0.05KGy while the lowest number of seeds (167) and the lowest 100 seed-weight of 1.56g was observed in the 0.30KGy treatments. (author)

  1. Lethal dose and clinical signs of Aeromonas hydrophila in Arapaima gigas (Arapaimidae), the giant fish from Amazon.

    Science.gov (United States)

    Dias, Marcia K R; Sampaio, Luciana S; Proietti-Junior, Aldo A; Yoshioka, Eliane T O; Rodrigues, Dália P; Rodriguez, Anselmo F R; Ribeiro, Ricardo A; Faria, Fernando S E D V; Ozório, Rodrigo O A; Tavares-Dias, Marcos

    2016-05-30

    Aeromonas hydrophila is causing substantial economic losses in world aquaculture. This study determined the tolerance limit (LD50-96h) of A. hydrophila in Arapaima gigas, and also investigated the clinical signs after intradermal inoculation. Arapaima gigas fingerlings were inoculated intraperitoneally with 0 (control), 1.0×10(5), 1.0×10(6), 1.0×10(7), 1.0×10(9) and 1.0×10(10)CFU/mL of A. hydrophila for the determination of LD50-96h, which was 1.8×10(8)CFU/mL. In another trial with intradermal inoculation of 1.8×10(8)CFU/mL A. hydrophila, there was a 91.6% of mortality between 8 and 23h, and several clinical signs were found. As follows: depigmentation in the tegument, lesions in the tail and fins, loss of balance, reduction of respiratory movements, hemorrhagic foci, necrotic hemorrhages in the kidney, liver and swim bladder, splenomegaly, ascites in the abdominal cavity and hyperemia, enlargement of the gall bladder, among other clinical signs observed. The results showed that A. gigas has a relative tolerance to A. hydrophila when compared to other Neotropical fish species. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Intraperitoneal fipronil effects on liver histopathological, biochemistry and morphology in Caspian kutum, Rutilus frisii kutum (Kamenskii, 1901

    Directory of Open Access Journals (Sweden)

    R. Alijani Ardeshir

    2017-12-01

    Full Text Available Fipronil is a relatively new insecticide in agriculture with health and environmental effects. This is the first report studying effect of fipronil on fish administered via intraperitoneal route. Intraperitoneal LD50  of fipronil in 16.3 g Caspian kutum, Rutilus frisii kutum, fingerlings was determined using a total of 133 fish in 19 tanks (7 fish/tank including one control and 6 treatment groups (300, 450, 550, 650, 750, 850 mg/kg. Fish were injected intraperitoneally and monitored at 96 h. The LD50 of fipronil was 632 mg/kg in Caspian kutum. Sub-lethal test doses of 10, 20, and 30% of the LD50 at 96 h were used to assess the effect of fipronil on the fish’s liver.  The blood plasma of 90 fish were used (18 at each test dose and in controls on days 7 and 14 for biochemistry. The hepatosomatic index (HSI of the livers were obtained and histopathology done on the same days. Pyknosis, sinusoid dilation and vacuolization were common histological changes, and these changes became more severe in a time and dose dependent manner. This dependence was also observed for HSI and the liver biochemical test (alanine and aspartate transaminase. Liver histological alterations showed that fipronil can be a potential factor in liver carcinoma.

  3. Acute and Subchronic Toxicity of Self Nanoemulsifying Drug Delivery Systems (SNEDDS) from Chloroform Bay Leaf Extract (Eugenia Polyantha W.) with Palm Kernel Oil as A Carrier

    Science.gov (United States)

    Prihapsara, F.; Mufidah; Artanti, A. N.; Harini, M.

    2018-03-01

    The present study was aimed to study the acute and subchronic toxicity of Self Nanoemulsifying Drug Delivery Systems (SNEDDS) from chloroform bay leaf extract with Palm Kernel Oil as carrier. In acute toxicity test, five groups of rat (n=5/groups) were orally treated with Self Nanoemulsifying Drug Delivery Systems (SNEDDS) from chloroform bay leaf extract with doses at 48, 240, 1200 and 6000 mg/kg/day respectively, then the median lethal dose LD50, advers effect and mortality were recorded up to 14 days. Meanwhile, in subchronic toxicity study, 4 groups of rats (n=6/group) received by orally treatment of SNEDDS from chloroform bay leaf extract with doses at 91.75; 183.5; 367 mg/kg/day respectively for 28 days, and biochemical, hematological and histopatological change in tissue such as liver, kidney, and pancreatic were determined. The result show that LD50 is 1045.44 mg/kg. Although histopathological examination of most of the organs exhibited no structural changes, some moderate damage was observed in high‑ dose group animals (367 mg/kg/day). The high dose of SNEDDS extract has shown mild signs of toxicity on organ function test.

  4. Irradiation sensibility of different provenances of Jatropha curcas L. seeds

    International Nuclear Information System (INIS)

    Yang Qing; Xu Congheng; Peng Daiping; Duan Zhubiao; Han Lei; Sun Qixiang; Peng Zhenhua

    2007-01-01

    The irradiation sensibility of 10 provenances of Jatropha curcas L. seeds to 60 Co γ-rays was studied. The results showed that the relationship between relative germination rate of the seeds and the doses of irradiation was negative correlation, and the difference of relative germination rate among different doses treatment was significant at 5% probability level or highly significant at 1% probability level. For seeds of different provenances, the correlation coefficient of linear regression was from -0.89--0.96, and the medial lethal doses (LD 50) of 10 provinces was from 127 Gy to 184 Gy. According to the LD 50, we could divided 10 provinces of J. curcas L. into sensitive provenance, transitional provenances and obtuse provenances. The provenances of Yuanjiang , Yunan (184 Gy) belonged to sensitive provenance; the provenances of Zhenfeng, Guizhou (127 Gy) and the provenances of Yuedong, Hainan (141 Gy) belonged to obtuse provenance; other 7 provenances belonged to transitional provenances. The results provided important experiment basis for germ plasma resources innovation of J. curcas L. (authors)

  5. Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R

    International Nuclear Information System (INIS)

    Atsmon, Jacob; Brill-Almon, Einat; Nadri-Shay, Carmit; Chertkoff, Raul; Alon, Sari; Shaikevich, Dimitri; Volokhov, Inna; Haim, Kirsten Y.; Bartfeld, Daniel; Shulman, Avidor; Ruderfer, Ilya; Ben-Moshe, Tehila; Shilovitzky, Orit; Soreq, Hermona; Shaaltiel, Yoseph

    2015-01-01

    PRX-105 is a plant-derived recombinant version of the human ‘read-through’ acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50 nmol/kg PRX-105, 2 min before being exposed to 1.33 × LD 50 and 1.5 × LD 50 of toxin and 10 min after exposure to 1.5 × LD 50 survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200 mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t ½ ) in mice was 994 (± 173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t ½ in humans was substantially longer than in mice (average 26.7 h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation. - Highlights: • PRX-105 is a PEGylated plant-derived recombinant human acetylcholinesterase-R. • PRX-105 is a promising bio-scavenger for organophosphorous toxins at lethal doses. • PRX-105 was shown to protect animals both prophylactically and post-poisoning. • First-in-human study exhibited its safety

  6. Preclinical and first-in-human evaluation of PRX-105, a PEGylated, plant-derived, recombinant human acetylcholinesterase-R

    Energy Technology Data Exchange (ETDEWEB)

    Atsmon, Jacob [Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University (Israel); Brill-Almon, Einat; Nadri-Shay, Carmit; Chertkoff, Raul; Alon, Sari [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Shaikevich, Dimitri; Volokhov, Inna; Haim, Kirsten Y. [Clinical Research Center, Tel Aviv Sourasky Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University (Israel); Bartfeld, Daniel [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Shulman, Avidor, E-mail: avidors@protalix.com [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Ruderfer, Ilya; Ben-Moshe, Tehila; Shilovitzky, Orit [Protalix Biotherapeutics, Science Park, Carmiel (Israel); Soreq, Hermona [Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem (Israel); Shaaltiel, Yoseph [Protalix Biotherapeutics, Science Park, Carmiel (Israel)

    2015-09-15

    PRX-105 is a plant-derived recombinant version of the human ‘read-through’ acetylcholinesterase splice variant (AChE-R). Its active site structure is similar to that of the synaptic variant, and it displays the same affinity towards organophosphorus (OP) compounds. As such, PRX-105 may serve as a bio-scavenger for OP pesticides and chemical warfare agents. To assess its potential use in prophylaxis and treatment of OP poisoning we conducted several preliminary tests, reported in this paper. Intravenous (IV) PRX-105 was administered to mice either before or after exposure to an OP toxin. All mice who received an IV dose of 50 nmol/kg PRX-105, 2 min before being exposed to 1.33 × LD{sub 50} and 1.5 × LD{sub 50} of toxin and 10 min after exposure to 1.5 × LD{sub 50} survived. The pharmacokinetic and toxicity profiles of PRX-105 were evaluated in mice and mini-pigs. Following single and multiple IV doses (50 to 200 mg/kg) no deaths occurred and no significant laboratory and histopathological changes were observed. The overall elimination half-life (t{sub ½}) in mice was 994 (± 173) min. Additionally, a first-in-human study, to assess the safety, tolerability and pharmacokinetics of the compound, was conducted in healthy volunteers. The t{sub ½} in humans was substantially longer than in mice (average 26.7 h). Despite the small number of animals and human subjects who were assessed, the fact that PRX-105 exerts a protective and therapeutic effect following exposure to lethal doses of OP, its favorable safety profile and its relatively long half-life, renders it a promising candidate for treatment and prophylaxis against OP poisoning and warrants further investigation. - Highlights: • PRX-105 is a PEGylated plant-derived recombinant human acetylcholinesterase-R. • PRX-105 is a promising bio-scavenger for organophosphorous toxins at lethal doses. • PRX-105 was shown to protect animals both prophylactically and post-poisoning. • First-in-human study

  7. High-throughput, signature-tagged mutagenic approach to identify novel virulence factors of Yersinia pestis CO92 in a mouse model of infection.

    Science.gov (United States)

    Ponnusamy, Duraisamy; Fitts, Eric C; Sha, Jian; Erova, Tatiana E; Kozlova, Elena V; Kirtley, Michelle L; Tiner, Bethany L; Andersson, Jourdan A; Chopra, Ashok K

    2015-05-01

    The identification of new virulence factors in Yersinia pestis and understanding their molecular mechanisms during an infection process are necessary in designing a better vaccine or to formulate an appropriate therapeutic intervention. By using a high-throughput, signature-tagged mutagenic approach, we created 5,088 mutants of Y. pestis strain CO92 and screened them in a mouse model of pneumonic plague at a dose equivalent to 5 50% lethal doses (LD50) of wild-type (WT) CO92. From this screen, we obtained 118 clones showing impairment in disseminating to the spleen, based on hybridization of input versus output DNA from mutant pools with 53 unique signature tags. In the subsequent screen, 20/118 mutants exhibited attenuation at 8 LD50 when tested in a mouse model of bubonic plague, with infection by 10/20 of the aforementioned mutants resulting in 40% or higher survival rates at an infectious dose of 40 LD50. Upon sequencing, six of the attenuated mutants were found to carry interruptions in genes encoding hypothetical proteins or proteins with putative functions. Mutants with in-frame deletion mutations of two of the genes identified from the screen, namely, rbsA, which codes for a putative sugar transport system ATP-binding protein, and vasK, a component of the type VI secretion system, were also found to exhibit some attenuation at 11 or 12 LD50 in a mouse model of pneumonic plague. Likewise, among the remaining 18 signature-tagged mutants, 9 were also attenuated (40 to 100%) at 12 LD50 in a pneumonic plague mouse model. Previously, we found that deleting genes encoding Braun lipoprotein (Lpp) and acyltransferase (MsbB), the latter of which modifies lipopolysaccharide function, reduced the virulence of Y. pestis CO92 in mouse models of bubonic and pneumonic plague. Deletion of rbsA and vasK genes from either the Δlpp single or the Δlpp ΔmsbB double mutant augmented the attenuation to provide 90 to 100% survivability to mice in a pneumonic plague model at 20

  8. An in vitro based investigation of the cytotoxic effect of water extracts of the Chinese herbal remedy LD on cancer cells

    Directory of Open Access Journals (Sweden)

    Jones Lucy A

    2009-09-01

    Full Text Available Abstract Background Long Dan Xie Gan Wan (LD, a Chinese herbal remedy formulation, is traditionally used to treat a range of conditions, including gall bladder diseases, hepatitis, hyperthyroidism, migraines but it is not used for the management or treatment of cancer. However some of its herbal constituents, specifically Radix bupleuri, Radix scutellariae and Rhizoma alismatis have been shown to inhibit the growth of cancer cells. Thus, the aim of the study was to investigate the impact of LD on cancer cells in vitro. Methods HL60 and HT29 cancer cell lines were exposed to water extracts of LD (1:10, 1:50, 1:100 and/or 1:1000 prepared from a 3 mg/30 ml stock and for both cell lines growth, apoptotic induction, alterations in cell cycle characteristics and genotoxicity were investigated. The specificity of the action of LD on these cancer cell lines was also investigated by determining its effect on human peripheral blood lymphocytes. Preliminary chemical analysis was carried out to identify cytotoxic constituents of LD using HPLC and LCMS. Results LD was significantly cytotoxic to, and induced apoptosis in, both cell lines. Apoptotic induction appeared to be cell cycle independent at all concentrations of LD used (1:10, 1:50 and 1:100 for the HL60 cell lines and at 1:10 for the HT29 cell line. At 1:50 and 1:100 apoptotic induction by LD appeared to be cell cycle dependent. LD caused significant genotoxic damage to both cell lines compared to their respective controls. The specificity study showed that LD exerted a moderate cytotoxic action against non-proliferating and proliferating blood lymphocytes but not apoptosis. Chemical analysis showed that a number of fractions were found to exert a significant growth inhibitory effect. However, the molecular weights of compounds within these fractions did not correspond to those from the herbal constituents of LD. Conclusion It is possible that LD may have some chemotherapeutic potential. However

  9. Response of mouse lung to irradiation at different dose-rates

    International Nuclear Information System (INIS)

    Hill, R.P.

    1983-01-01

    Groups of LAF1 mice were given thoracic irradiation using 60 Co γ-rays at dose-rates of 0.05 Gy/min (LDR) or 1.1 Gy/min (HDR) and the death of the animals was monitored as a function of time. It was found that the time pattern of animal deaths was similar for the two different dose-rates. Dose response curves for animals dying at various times up to 500 days after irradiation were calculated and the LD 50 values determined. The curves for the LD 50 values, plotted as a function of the time at analysis for treatment at HDR or LDR, were essentially parallel to each other but separated by a factor (LDR/HDR) of about 1.8. This indicates that the sparing effect of LDR treatment is the same for deaths occurring during the early pneumonitis phase or during the late fibrotic phase of lung damage. The available information on the response of patients to whole thoracic irradiation, given for either palliation or piror to bone marrow transplantation, suggests that for similar dose-rates to those studied here the ratio (LDR/HDR) is only 1.2 to 1.3. This difference between the animal and human data may reflect the modifying effect of the large doses of cytotoxic drugs used in combination with the irradiation of bone marrow transplant patients

  10. Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine

    International Nuclear Information System (INIS)

    Gasinska, A.

    1995-01-01

    The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. α/β coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction α/β for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). α/β coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method α/β for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of α/β coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (F r ) was much bigger for photons. For X-rays it was 50% for early and 63% for late effects. In case of

  11. Inorganic and organic mercury chloride toxicity to Coturnix: Sensitivity related to age and quantal assessment of physiologic responses

    Science.gov (United States)

    Hill, E.F.

    1982-01-01

    The toxicities of mercuric chloride (HgCl(,2)) and methylmercuric chloride (CH(,3)HgCl) were compared for coturnix (Coturnix coturnix japonica) from hatching to adulthood. Comparisons were based on: (1) Median lethal dosages (LD50) derived by administering single peroral and single intramuscular dosages of mercury, (2) median lethal concentrations (LC50) derived by feeding mercury for 5 days, (3) median toxic concentrations (TC50) derived by feeding mercury 9 weeks and measuring plasma enzyme activity, plasma electrolytes, and other blood constituents, and (4) transient changes of various blood chemistries following a single peroral dose of mercury. Acute peroral and intramuscular LD50s for HgCl(,2) and CH(,3)HgCl increased by two- to threefold for coturnix chicks from hatching to 4 weeks of age. Concomitantly, the LC50s also increased, but the important difference between test procedures was that with both single dose routes of exposure the toxicity ratios, i.e., HgCl(,2)/CH(,3)HgCl, at each age were about 2 to 2.5 compared to about 100 for the LC50s. For example, at 2 weeks of age the peroral LD50s for HgCl(,2) and CH(,3)HgCl were 42 and 18 mg/kg; the dietary LC50s were 5086 and 47 ppm for HgCl(,2) and CH(,3)HgCl. The 9 week feeding trial was not associated with gross effects from either HgCl(,2) at 0.5 to 32 ppm or CH(,3)HgCl at 0.125 to 8 ppm. However, subtle responses were detected for the plasma enzymes aspartate aminotransferase, lactate dehydrogenase, and ornithine carbamoyl transferase and could be quantified by probit analysis. This quantal procedure was based on establishment of a normal value for each enzyme and classing outliers as respondents. A 'hazard index' based on the TC50 for an enzyme divided by the LD50 or LC50 was introduced. The single oral dosages of HgCl(,2) and CH(,3)HgCl showed that ratios of alanine aminotransferase, lactate dehydrogenase, and orinthine carbamoyl transferase for the liver and kidneys of adult coturnix were opposite from

  12. Determination of Drug Toxicity Using 3D Spheroids Constructed From an Immortal Human Hepatocyte Cell Line

    Science.gov (United States)

    Fey, Stephen J.; Wrzesinski, Krzysztof

    2012-01-01

    Numerous publications have documented that the immortal cells grown in three-dimensional (3D) cultures possess physiological behavior, which is more reminiscent of their parental organ than when the same cells are cultivated using classical two-dimensional (2D) culture techniques. The goal of this study was to investigate whether this observation could be extended to the determination of LD50 values and whether 3D data could be correlated to in vivo observations. We developed a noninvasive means to estimate the amount of protein present in a 3D spheroid from it is planar area (± 21%) so that a precise dose can be provided in a manner similar to in vivo studies. This avoided correction of the actual dose given based on a protein determination after treatment (when some cells may have lysed). Conversion of published in vitro LC50 data (mM) for six common drugs (acetaminophen, amiodarone, diclofenac, metformin, phenformin, and valproic acid) to LD50 data (mg compound/mg cellular protein) showed that the variation in LD50 values was generally less than that suggested by the original LC50 data. Toxicological analysis of these six compounds in 3D spheroid culture (either published or presented here) demonstrated similar LD50 values. Although in vitro 2D HepG2 data showed a poor correlation, the primary hepatocyte and 3D spheroid data resulted in a much higher degree of correlation with in vivo lethal blood plasma levels. These results corroborate that 3D hepatocyte cultures are significantly different from 2D cultures and are more representative of the liver in vivo. PMID:22454432

  13. Plasma microRNA profiles distinguish lethal injury in acetaminophen toxicity: A research study

    Institute of Scientific and Technical Information of China (English)

    Jeanine Ward; Shashi Bala; Jan Petrasek; Gyongyi Szabo

    2012-01-01

    AIM:To investigate plasma microRNA (miRNA) profiles indicative of hepatotoxicity in the setting of lethal acetaminophen (APAP) toxicity in mice.METHODS:Using plasma from APAP poisoned mice,either lethally (500 mg/kg) or sublethally (150 mg/kg) dosed,we screened commercially available murine microRNA libraries (SABiosciences,Qiagen Sciences,MD) to evaluate for unique miRNA profiles between these two dosing parameters.RESULTS:We distinguished numerous,unique plasma miRNAs both up- and downregulated in lethally compared to sublethally dosed mice.Of note,many of the greatest up- and downregulated miRNAs,namely 574-5p,466g,466f-3p,375,29c,and 148a,have been shown to be associated with asthma in prior studies.Interestingly,a relationship between APAP and asthma has been previously well described in the literature,with an as yet unknown mechanism of pathology.There was a statistically significant increase in alanine aminotransferase levels in the lethal compared to sublethal APAP dosing groups at the 12 h time point (P <0.001).There was 90% mortality in the lethally compared to sublethally dosed mice at the 48 h time point (P =0.011).CONCLUSION:We identified unique plasma miRNAs both up- and downregulated in APAP poisoning which are correlated to asthma development.

  14. Radio-sensitivity and mutability in lentil (Lens culinars Medik.) as related to seed size

    International Nuclear Information System (INIS)

    Malik, I.A.; Chaudhry, M.S.; Ashraf, M.; Erskine, W.

    1998-01-01

    Eight diverse genotypes of lentil (Lens culinaris Medikus) were irradiated with 0, 10, 20, 30 and 40 kR of gamma rays. The mean lethal dose (LD50) for survival was 25.0 kR, radiation sensitivity varying over genotypes from 51.6 to 16.2 kR. The optimum irradiation dose to produce chlorophyll mutants was 21.8 kR, and that for morphological mutants was 21.4 kR. Correlations were made between a group of traits measuring radio-sensitivity and mutability, and a range of other plant characters. Most correlation coefficients between the two character groups were non-significant [it

  15. Chemical protection against gastrointestinal radiation injury in mice by WR 2822, WR 2823, or WR 109342 after 4 MeV x ray or fission neutron irradiation

    International Nuclear Information System (INIS)

    Connor, A.M.; Sigdestad, C.P.

    1982-01-01

    Three compounds were tested for their radioprotective properties against the effects of 4 MeV X rays or fission neutron irradiation. The endpoints tested were lethality, intestinal crypt survival, and DNA synthesizing cellularity. Two of the compounds tested; S-2(4-aminobutylamino) ethylphosphorothioc acid (WR 2822) and the aminopentylamino derivative (WR 109342). All drugs were administered via intraperitoneal injections at their approximately maximum tolerated dose. WR 2822 was shown to have a slight protective effect against X rays and neutrons. The dose modification factor (DMF) for gastrointestinal death (LD/sub 50(6)/) was 1.23 for X rays and 1.51 for neutrons. The assay for intestinal crypt survival produced DMF's of 1.44 (X rays) and 1.4 (neutrons). WR 2823 also showed a protective action in these assays. The DMF for LD/sub 50(6)/ was 1.32 (X rays) and 1.42 (neutrons). WR 109342 was found to be extremely toxic and had no significant protective effects. All three drugs were more toxic and demonstrated less protection in most of these assays than the benchmark radioprotective agent WR 2721, although WR 2822 protected against lethal effects of fission neutrons almost as well as WR 2721. Both WR 2822 and WR 2823 produced greater protection in the crypt survival assays for fission neutron irradiation than WR 2721

  16. Local inflammation, lethality and cytokine release in mice injected with Bothrops atrox venom

    Directory of Open Access Journals (Sweden)

    S. F. Barros

    1998-01-01

    Full Text Available We have provided evidence that: (a lethality of mice to crude Bothrops venom varies according the isogenic strain (A/J > C57Bl/6 > A/Sn > BALB/c > C3H/ HePas > DBA/2 > C3H/He; (bBALB/c mice (LD50=100.0 μg were injected i.p. with 50 μg of venom produced IL-6, IL-10, INF-γ, TNF-α and NO in the serum. In vitro the cells from the mice injected and challenged with the venom only released IL-10 while peritoneal macrophages released IL-10, INF-γ and less amounts of IL-6; (c establishment of local inflammation and necrosis induced by the venom, coincides with the peaks of TNF-α, IFN-γ and NO and the damage was neutralized when the venom was incubated with a monoclonal antibody against a 60 kDa haemorrhagic factor. These results suggest that susceptibility to Bothrops a trox venom is genetically dependent but MHC independent; that IL-6, IL10, TNF-α, IFN-γ and NO can be involved in the mediation of tissue damage; and that the major venom component inducers of the lesions are haemorrhagins.

  17. Toxicological Evaluation of Essential Oil From the Leaves of Croton argyrophyllus (Euphorbiaceae) on Aedes aegypti (Diptera: Culicidae) and Mus musculus (Rodentia: Muridae).

    Science.gov (United States)

    Cruz, R C D; Silva, S L C E; Souza, I A; Gualberto, S A; Carvalho, K S; Santos, F R; Carvalho, M G

    2017-07-01

    Plant-derived essential oils can be used as insecticides for vector control. However, to establish their safety, it is necessary to perform toxicological studies. Herein, we evaluated the chemical composition and insecticidal activity of the essential oil from the leaves of Croton argyrophyllus on the third- and fourth-instar larvae and adult Aedes aegypti (L., 1762). We also evaluated the acute toxicity of the essential oil in adult female Mus musculus. The lethal concentration 50 (LC50) and 90 (LC90) of C. argyrophyllus essential oil on larvae of Ae. aegypti were 0.31 and 0.70 mg ml-1, respectively, and 5.92 and 8.94 mg ml-1, respectively, on Ae. aegypti adults. The major components of the essential oil were spathulenol (22.80%), (E)-caryophyllene (15.41%), α-pinene (14.07%), and bicyclogermacrene (10.43%). It also displayed acute toxicity in adults of Mus musculus; the intraperitoneal and oral lethal dose 50 (LD50) were 2,000 mg kg-1 and 2,500 mg kg-1, respectively. The results showed that the essential oil from C. argyrophyllus leaves has insecticidal activity on Ae. aegypti larvae and adults at an average lethal concentration below the median lethal dose needed to cause acute toxicity in the common mouse. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Assessment of A Simple Compound-Saving Method To Study Insecticidal Activity of Natural Extracts and Pure Compounds Against Mosquito Larvae.

    Science.gov (United States)

    Falkowski, Michaël; Jahn-Oyac, Arnaud; Ferrero, Emma; Issaly, Jean; Eparvier, Véronique; Girod, Romain; Rodrigues, Alice M S; Stien, Didier; Houël, Emeline; Dusfour, Isabelle

    2016-12-01

    Research on natural insecticides has intensified with the spread of resistance to chemicals among insects, particularly disease vectors. To evaluate compounds, the World Health Organization (WHO) has published standardized procedures. However, those may be excessively compound-consuming when it comes to assessing the activity of natural extracts and pure compounds isolated in limited amount. As part of our work on the discovery of new mosquito larvicides from Amazonian plants, we developed a compound-saving assay in 5-ml glass tubes instead of WHO larval 100-ml cups. Comparing activity of synthetic and natural chemicals validated the glass tube assay. Raw data, lethal doses that kill 50% (LD 50 ) and 90% (LD 90 ) at 24 and 48 h, were highly correlated (0.68 natural extracts and molecules, identifying active compounds using 10 times less material than in the WHO protocol.

  19. The paradox of human equivalent dose formula: A canonical case study of abrus precatorius aqueous leaf extract in monogastric animals

    Directory of Open Access Journals (Sweden)

    Saganuwan Alhaji Saganuwan

    2016-03-01

    Full Text Available There is abundant literature on the toxicity of A. precatorius seeds. However there is a need to define the toxicity limit of the Abrus precatorius leaf in monogastric animals. Human Equivalent Dose (HED which is equal to animal dose multiplied by animal km (metabolism constant divided by human km was used to project the LD50 of fifteen monogastric animals , where human km factor is body weight (kg divided by body surface area (m2. Human Equivalent No-observable Adverse Effect Doses were determined by multiplying the animal no-observable adverse effect dose by animal weight (Wa divided by human weight (Wh. The LD50 of the aqueous leaf extract of Abrus precatorius in mice was estimated to be between 2559.5 and 3123.3 mg/kg body weight. The LD50 extrapolated from mouse to rat (1349.3-1646.6 mg/kg, hamster (1855.3-2264.1 mg/kg, guinea pig (1279.5-1561.4 mg/kg, rabbit (618.4-754.7 mg/kg, monkey (593.7-724.5 mg/kg, cat (392.7-479.2 mg/kg, dog and baboon (371.1-452.8 mg/kg, child (297-362 mg/kg and adult human (197.8-241.5 mg/kg body weight respectively could be a reality. The therapeutic safe dose range for the animals was 1-12.5 mg/kg body weight for a period of 7 days, but at a dose (≤ 200 mg/kg body weight the leaf extract showed haematinic effect. However, at a higher dose (> 200 mg/kg, the extract showed haemolytic activity in rats, whereas at a dose (≥25.0 mg/kg, the leaf extract might be organotoxic in hamster, guinea pig, rabbit, monkey, cat, dog, baboon, child and adult human if administered orally for a period of 7 days.

  20. UV-induced lethal sectoring and pure mutant clones in yeast.

    Science.gov (United States)

    Hannan, M A; Duck, P; Nasim, A

    1976-08-01

    The induction of lethal sectoring and pure mutant clones by ultraviolet light has been studied in a homogeneous G1 population of Saccharomyces cerevisiae grown in a normal growth medium. At the lowest UV dose of 250 ergs, which corresponds to a shoulder in the survival curve, all mutants appeared as pure clones. At higher doses the frequency of mosaic mutants progressively increased. These results indicate a relationship between the highest frequency of complete mutants and the maximum repair activity. In addition, the frequency of lethal sectoring at all doses tested was too low to account for the origin of pure mutant clones.

  1. Doses-effect regression equations for some growth indicators of rice plantules from CO60 irradiated seeds

    International Nuclear Information System (INIS)

    Lopez, R.C.; Gonzalez, L.M.; Garcia, D.

    1993-01-01

    In the present work, dose-effect regression equations for energy and percentage germination, size, root length and dry mass of plantules from which values of DL-50 middle lethal dose were calculated and likely or unlikely equivalencies among them were established

  2. Effects of chronic γ-irradiation on growth and survival of the Tohoku hynobiid salamander, Hynobius lichenatus

    Energy Technology Data Exchange (ETDEWEB)

    Fuma, Shoichi [Project for Environmental Dynamics and Radiation Effects, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Une, Yumi [Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 (Japan); Ihara, Sadao [Hokkaido University of Education Kushiro Campus, 1-15-55 Shiroyama, Kushiro, Hokkaido 085-8580 Japan (Japan); Matsui, Kumi [Laboratory of Veterinary Physiology 1, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 (Japan); Kudo, Tomoo; Tokiwa, Toshihiro [Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 (Japan); Kubota, Yoshihisa; Soeda, Haruhi [Project for Environmental Dynamics and Radiation Effects, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Ishikawa, Takahiro [Department of Technical Support and Development, Research, Development and Support Centre, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Doi, Kazutaka [Project for Human Health, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan); Watanabe, Yoshito; Yoshida, Satoshi [Project for Environmental Dynamics and Radiation Effects, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 Japan (Japan)

    2014-09-15

    The Tohoku hynobiid salamanders, Hynobius lichenatus, were chronically irradiated with γ-rays from embryonic to juvenile stages for 450 days. At 490 μGy h{sup −1} or lower dose rates, growth and survival were not significantly affected by irradiation, and any morphological aberrations and histological damages were not observed. At 4600 μGy h{sup −1}, growth was severely inhibited, and all the individuals died mostly at the juvenile stage. Chronic LD{sub 50} was 42 Gy as a total dose. In the liver, the number of hematopoietic cells was significantly reduced in the living juveniles, and these cells disappeared in the dead juveniles. In the spleen, mature lymphocytes were depleted in the living larvae, and almost all the heamtopoietic cells disappeared in the dead juveniles. These results suggest that this salamander died due to acute radiation syndrome, i.e., hematopoietic damage and subsequent sepsis caused by immune depression. The death would be also attributed to skin damage inducing infection. At 18,000 μGy h{sup −1}, morphological aberrations and severe growth inhibition were observed. All the individuals died at the larval stage due to a multiple organ failure. Chronic LD{sub 50} was 28 Gy as a total dose. Assuming that chronic LD{sub 50} was 42 Gy at lower dose rates than 4600 μGy h{sup −1}, a chronic median lethal dose rate could be estimated to be <340 μGy h{sup −1} for the whole life (>14 years). These results suggest that, among guidance dose rates, i.e., 4–400 μGy h{sup −1}, proposed by various organisations and research programmes for protection of amphibians and taxonomic groups or ecosystems including amphibians, most of them would protect this salamander but the highest value may not on the whole life scale. - Highlights: • The salamanders, Hynobius lichenatus, were chronically γ-irradiated for 450 days. • At 490 μGy h{sup −1} or lower, irradiation did not significantly affect growth and survival. • All the individuals

  3. Protection against soman-induced seizures in rats: relationship among doses of prophylactics, soman, and adjuncts

    International Nuclear Information System (INIS)

    Myhrer, Trond; Nguyen, Nga H.T.; Andersen, Jannike M.; Aas, Paal

    2004-01-01

    The combined effects of physostigmine and procyclidine (antagonizing muscarinic, nicotinic, and NMDA receptors) were tested against various doses of soman. Physostigmine (0.1 mg/kg) in combination with procyclidine doses of 1, 3, or 6 mg/kg effectively prevented the development of convulsions and hippocampally monitored seizures when the doses of soman were 1.3, 1.6, or 2 x LD50, respectively. Results from [ 3 H]MK-801-binding experiments showed that procyclidine inhibits the phencyclidine site at the NMDA receptor in a concentration-dependent manner. Physostigmine (0.1 mg/kg) and procyclidine in a dose of 1 mg/kg did not prevent convulsions or seizures when the soman dose was 1.6 x LD50. Subsequent treatment with scopolamine in doses of 0.5 or 1 mg/kg immediately after (3 min) seizure onset showed that only the highest dose produced a reliable termination. When scopolamine (1 mg/kg) was given later (10 min) after onset of seizures, no effect was obtained. The sustained seizures were subsequently treated with diazepam (10 mg/kg) and pentobarbital (30 mg/kg) and finally terminated 25 min after onset. In rats given inadequate prophylaxis, both modified convulsions and seizures were seen. It is suggested that moderate doses of prophylactics should be preferred to avoid adverse effects on cognitive functions because insufficient prophylaxis can be compensated for by adjunct treatment

  4. Mouse dendritic cells pulsed with capsular polysaccharide induce resistance to lethal pneumococcal challenge: roles of T cells and B cells.

    Directory of Open Access Journals (Sweden)

    Noam Cohen

    Full Text Available Mice are exceedingly sensitive to intra-peritoneal (IP challenge with some virulent pneumococci (LD50 = 1 bacterium. To investigate how peripheral contact with bacterial capsular polysaccharide (PS antigen can induce resistance, we pulsed bone marrow dendritic cells (BMDC of C57BL/6 mice with type 4 or type 3 PS, injected the BMDC intra-foot pad (IFP and challenged the mice IP with supra-lethal doses of pneumococci. We examined the responses of T cells and B cells in the draining popliteal lymph node and measured the effects on the bacteria in the peritoneum and blood. We now report that: 1 The PS co-localized with MHC molecules on the BMDC surface; 2 PS-specific T and B cell proliferation and IFNγ secretion was detected in the draining popliteal lymph nodes on day 4; 3 Type-specific resistance to lethal IP challenge was manifested only after day 5; 4 Type-specific IgM and IgG antibodies were detected in the sera of only some of the mice, but B cells were essential for resistance; 5 Control mice vaccinated with a single injection of soluble PS did not develop a response in the draining popliteal lymph node and were not protected; 6 Mice injected with unpulsed BMDC also did not resist challenge: In unprotected mice, pneumococci entered the blood shortly after IP inoculation and multiplied exponentially in both blood and peritoneum killing the mice within 20 hours. Mice vaccinated with PS-pulsed BMDC trapped the bacteria in the peritoneum. The trapped bacteria proliferated exponentially IP, but died suddenly at 18-20 hours. Thus, a single injection of PS antigen associated with intact BMDC is a more effective vaccine than the soluble PS alone. This model system provides a platform for studying novel aspects of PS-targeted vaccination.

  5. Susceptibility and pathological consequences of catla, Catla catla (Hamilton experimentally infected with Edwardsiella tarda

    Directory of Open Access Journals (Sweden)

    Devi Thongam Bidya

    2016-12-01

    Full Text Available The present study tested the susceptibility and pathological changes of catla, Catla catla (Hamilton infected with Edwardsiella tarda (ET-PG-29. The bacterium was isolated from the kidney of a diseased pangas catfish. To determine the median lethal dose (LD50, C. catla were challenged with this bacterium (108-103 CFU ml-1, and the LD50 was calculated as 105.5 CFU ml-1. Another set of healthy C. catla were injected intraperitoneally with the LD50 dose to induce edwardsiellosis. The clinical signs of the infected C. catla were observed and recorded. Tissues such as kidney, liver, intestine, heart, and gill from the infected fish with clinical signs of edwardsiellosis were used for histopathology. The clinical and gross signs were first visible at 1 d post-injection, and the infected fish showed typical signs of hemorrhagic septicemia. The most striking histopathological features were found in the kidney which showed multi-focal necrosis with the formation of granuloma indicating an inflammatory response against the pathogen. The intestine displayed goblet cell hyperplasia, the liver showed hydropic degeneration with hyperemic central veins, and there was inflammation of gill lamellae and cardiac myositis associated with leucocyte infiltration. Collectively, the results confirmed the susceptibility of C. catla to E. tarda infection and that this bacterium is a threat to C. catla in aquaculture practices.

  6. Dosing-time contributes to chronotoxicity of clofarabine in mice via means other than pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Jia-Jie Luan

    2016-05-01

    Full Text Available To evaluate the time- and dose-dependent toxicity of clofarabine in mice and to further define the chronotherapy strategy of it in leukemia, we compared the mortality rates, LD50s, biochemical parameters, histological changes and organ indexes of mice treated with clofarabine at various doses and time points. Plasma clofarabine levels and pharmacokinetic parameters were monitored continuously for up to 8 hours after the single intravenous administration of 20 mg/kg at 12:00 noon and 12:00 midnight by high performance liquid chromatography (HPLC-UV method. Clofarabine toxicity in all groups fluctuated in accordance with circadian rhythms in vivo. The toxicity of clofarabine in mice in the rest phase was more severe than the active one, indicated by more severe liver damage, immunodepression, higher mortality rate, and lower LD50. No significant pharmacokinetic parameter changes were observed between the night and daytime treatment groups. These findings suggest the dosing-time dependent toxicity of clofarabine synchronizes with the circadian rhythm of mice, which might provide new therapeutic strategies in further clinical application.

  7. The relationship between total cholinesterase activity and mortality in four butterfly species

    Science.gov (United States)

    Bargar, Timothy A.

    2012-01-01

    The relationship between total cholinesterase activity (TChE) and mortality in four butterfly species (great southern white [Ascia monuste], common buckeye [Junonia coenia], painted lady [Vanessa cardui], and julia butterflies [Dryas julia]) was investigated. Acute contact toxicity studies were conducted to evaluate the response (median lethal dose [LD50] and TChE) of the four species following exposure to the organophosphate insecticide naled. The LD50 for these butterflies ranged from 2.3 to 7.6 μg/g. The average level of TChE inhibition associated with significant mortality ranged from 26 to 67%, depending on the species. The lower bounds of normal TChE activity (2 standard deviations less than the average TChE for reference butterflies) ranged from 8.4 to 12.3 μM/min/g. As a percentage of the average reference TChE activity for the respective species, the lower bounds were similar to the inhibition levels associated with significant mortality, indicating there was little difference between the dose resulting in significant TChE inhibition and that resulting in mortality.

  8. Radiosensitivity of lentil beam (Lens culinaris L.) to gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Kyu; Ryu, Jaihyunk; Jeong, Sang Wook; Kim, Jin Baek; Kang, Si Young; Kwon, Soon Jae [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2017-02-15

    We examined damages from gamma-irradiation and determined the optimal gamma ray dose for mutation breeding in lentil (Lens culinaris L.) bean. Four individual lines (L-C, L-2, L-8 and L-9), that have remarkable adaptability in South Korea were gamma-irradiated at doses of 50, 70, 100, 200, 300, 400, and 500 Gy. The germination rate of seed decreased as the dose increased over 50 Gy in all lines. However, LD{sub 50} and RD{sub 50} were different among lines. The median lethal doses (LD50) were approximately 127 (L-C), 74 (L-2), 95 (L-8), and 144 (L-9) Gy. The median reduction doses (RD{sub 50}) for plant height, number of leaves, root length, and flash weight were 156, 176, 150, and 180 Gy for L-C, 253, 198, 127, and 142 Gy for L-2, 188, 175, 200, and 190 Gy for L-8, and 162, 210, 224, and 184 for L-9, respectively. The growth characteristics of the M1 generation decreased as the dose increased over 70 Gy. The optimal doses of gamma irradiation for mutation breeding of lentil were determined to be 70 Gy (L-2, L-8) and 100 Gy (L-C, L-9). We performed the comet assay to observe nuclear DNA damage induced by gamma-irradiation. In comet assay, a clear difference was identified over 100 Gy treatments. With increasing doses of gamma-ray in the range of 50 to 500 Gy, the rate of head DNA was decreased significantly from 97.5% to 81.6%. Tail length was consecutively increased from 1.9 μm to 17.4 μm. Our result provides basic information for construction of mutant pools in lentils.

  9. Radiosensitivity of lentil beam (Lens culinaris L.) to gamma-irradiation

    International Nuclear Information System (INIS)

    Lee, Min Kyu; Ryu, Jaihyunk; Jeong, Sang Wook; Kim, Jin Baek; Kang, Si Young; Kwon, Soon Jae

    2017-01-01

    We examined damages from gamma-irradiation and determined the optimal gamma ray dose for mutation breeding in lentil (Lens culinaris L.) bean. Four individual lines (L-C, L-2, L-8 and L-9), that have remarkable adaptability in South Korea were gamma-irradiated at doses of 50, 70, 100, 200, 300, 400, and 500 Gy. The germination rate of seed decreased as the dose increased over 50 Gy in all lines. However, LD_5_0 and RD_5_0 were different among lines. The median lethal doses (LD50) were approximately 127 (L-C), 74 (L-2), 95 (L-8), and 144 (L-9) Gy. The median reduction doses (RD_5_0) for plant height, number of leaves, root length, and flash weight were 156, 176, 150, and 180 Gy for L-C, 253, 198, 127, and 142 Gy for L-2, 188, 175, 200, and 190 Gy for L-8, and 162, 210, 224, and 184 for L-9, respectively. The growth characteristics of the M1 generation decreased as the dose increased over 70 Gy. The optimal doses of gamma irradiation for mutation breeding of lentil were determined to be 70 Gy (L-2, L-8) and 100 Gy (L-C, L-9). We performed the comet assay to observe nuclear DNA damage induced by gamma-irradiation. In comet assay, a clear difference was identified over 100 Gy treatments. With increasing doses of gamma-ray in the range of 50 to 500 Gy, the rate of head DNA was decreased significantly from 97.5% to 81.6%. Tail length was consecutively increased from 1.9 μm to 17.4 μm. Our result provides basic information for construction of mutant pools in lentils

  10. Possibilities for prognostication of radiation injury in rats by leucocyte nucleic acid levels

    International Nuclear Information System (INIS)

    Minkova, M.; Pantev, T.

    1988-01-01

    The possibilities to prognosticate acute radiation injury by the changes in the amount of nucleic acids in the leucocytes was studied. Experiments were carried out on male Wistar albino rats, gamma-irradiated with nonlethal and sublethal doses of 0.5, 2 and 4 Gy and lethal dose of 8 Gy (LD 90/30 ). The nucleic acid content and the total leucocyte count were determined at definite intervals on days 1-30. The changes in the nucleic acids in nonlethally and sublethally irradiated animals had phase nature, with a clear-cut abortive increase in their amount on days 7-10. In lethally irradiated animals the phase character of the changes was lost and the abortive peak disappeared. By reducing the effectiveness of the lethal radiation dose survival of the population increased from 10-75% through physical and from 10-70% - through chemical protection. The nucleic acid dynamics showed features typical for an injury with possible survival - appearance of abortive peak and resumption of their normal values. It is assumed that determination of leucocyte nucleic acid content may be used for early prognostication of radiation injury, as it allows keen differentiation of the lethal from nonlethal outcome of radiation sickness. The absence of abortive peak (over 50%) by day 14 post-irradiation is a poor prognostic sign

  11. Biochemical Properties and Mechanism of Action of Enterocin LD3 Purified from Enterococcus hirae LD3.

    Science.gov (United States)

    Gupta, Aabha; Tiwari, Santosh Kumar; Netrebov, Victoria; Chikindas, Michael L

    2016-09-01

    Enterocin LD3 was purified using activity-guided multistep chromatography techniques such as cation-exchange and gel-filtration chromatography. The preparation's purity was tested using reverse-phase ultra-performance liquid chromatography. The specific activity was tested to be 187.5 AU µg(-1) with 13-fold purification. Purified enterocin LD3 was heat stable up to 121 °C (at 15 psi pressure) and pH 2-6. The activity was lost in the presence of papain, reduced by proteinase K, pepsin and trypsin, but was unaffected by amylase and lipase, suggesting proteinaceous nature of the compound and no role of carbohydrate and lipid moieties in the activity. MALDI-TOF/MS analysis of purified enterocin LD3 resolved m/z 4114.6, and N-terminal amino acid sequence was found to be H2NQGGQANQ-COOH suggesting a new bacteriocin. Dissipation of membrane potential, loss of internal ATP and bactericidal effect were recorded when indicator strain Micrococcus luteus was treated with enterocin LD3. It inhibited Gram-positive and Gram-negative bacteria including human pathogens such as Staphylococcus aureus, Pseudomonas fluorescens, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexneri, Listeria monocytogenes, Escherichia coli O157:H7, E. coli (urogenic, a clinical isolate) and Vibrio sp. These properties of purified enterocin LD3 suggest its applications as a food biopreservative and as an alternative to clinical antibiotics.

  12. Acute and sub-lethal response to mercury in Arctic and boreal calanoid copepods.

    Science.gov (United States)

    Overjordet, Ida Beathe; Altin, Dag; Berg, Torunn; Jenssen, Bjørn Munro; Gabrielsen, Geir Wing; Hansen, Bjørn Henrik

    2014-10-01

    Acute lethal toxicity, expressed as LC50 values, is a widely used parameter in risk assessment of chemicals, and has been proposed as a tool to assess differences in species sensitivities to chemicals between climatic regions. Arctic Calanus glacialis and boreal Calanus finmarchicus were exposed to mercury (Hg(2+)) under natural environmental conditions including sea temperatures of 2° and 10°C, respectively. Acute lethal toxicity (96 h LC50) and sub-lethal molecular response (GST expression; in this article gene expression is used as a synonym of gene transcription, although it is acknowledged that gene expression is also regulated, e.g., at translation and protein stability level) were studied. The acute lethal toxicity was monitored for 96 h using seven different Hg concentrations. The sub-lethal experiment was set up on the basis of nominal LC50 values for each species using concentrations equivalent to 50, 5 and 0.5% of their 96 h LC50 value. No significant differences were found in acute lethal toxicity between the two species. The sub-lethal molecular response revealed large differences both in response time and the fold induction of GST, where the Arctic species responded both faster and with higher mRNA levels of GST after 48 h exposure. Under the natural exposure conditions applied in the present study, the Arctic species C. glacialis may potentially be more susceptible to mercury exposure on the sub-lethal level. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Effects of sub-lethal dose of γ-irradiation on lysosomal enzymes in tissue of pigeon

    International Nuclear Information System (INIS)

    Shah, V.C.; Gadhia, P.K.

    1979-01-01

    Effects of total body γ-irradiation with sub-lethal dose (300 rad) on three lysosomal enzymes namely acid phosphatase, ribonuclease-II and deoxyribonuclease-II have been studied in pigeons. Liver, kidney and spleen were the tissues studied at different intervals like 1-h, 24-h, 48-h, and 72-h of irradiation. The specific activities ('crude' fraction) of acid phosphatase and ribonuclease-II increased significantly in spleen and liver at 48-h of irradiation. The activity of deoxyribonuclease-II in liver and spleen was increased only at 72-h post-irradiation. On the other hand, the total activities of three lysosomal enzymes did not show remarkable change throughout 72-h of irradiation. (author)

  14. Todralazine protects zebra fish from lethal doses of ionizing radiation: role of hematopoietic stem cell expansion

    International Nuclear Information System (INIS)

    Dimri, Manali; Joshi, Jaidev; Indracanti, Prem Kumar

    2013-01-01

    Radiation induced cell killing and hematopoietic stem cell depletion leads to compromised immune functions and opportunistic infections which significantly affect the recovery and survival upon irradiation. Any agent which can expand residual hematopoietic stem cells in irradiated organism can render protection from the effects of lethal doses of ionizing radiation. Johns Hopkins Clinical compound library (JHCCL) was screened for protection against lethal doses of ionizing radiation using developing zebra fish as a model organism. Modulation of radiation induced reactive oxygen species by the small molecules were done by DCFDA staining and for visual identification and quantification of apoptosis acridine orange assay, flow cytometry were employed respectively. Hematopoietic stem cell expansion potential was assessed by quantifying runx1 expression, a marker for definitive stem cells, were done by RT-PCR and by the kinetics of recovery from chemically induced anaemia. Todralazine hydrochloride from JHCCL exhibited promising results with potential anti radiation effects. A dose of 5μM was found to be the most effective and has rendered significant organ and whole body protection (100% survival advantage over a period of 6 days) against 20 Gy. However todralazine did not modulated radiation induced free radicals (monitored within 2 h of irradiation) and apoptosis in zebra fish embryos analysed at 8 and 24h post irradiation. Flow cytometric quantification of pre G1 population suggested the same. Chemoinformatics approaches were further carried out to elucidate possible targets which are contributing to its radioprotection potential. Structural similarity search suggested several targets and possible hematopoietic stem cell expanding potential. Treatment of zebra fish embryos with todralazine has lead to significant proliferation of hematopoietic stem cell as indicated by increase in expression of runx1. HSC expanding potential of todralazine was further supported by

  15. Acute and sub-chronic toxicity evaluations of aqueous extract from stem bark of Grewia mollis (Malvaceae in rats

    Directory of Open Access Journals (Sweden)

    Pongri Adarki

    2017-09-01

    Full Text Available Introduction: Different parts of Grewia mollis Juss. (Malvaceae are commonly used in folk medicine to treat several ailments, including diarrhea, ulcers, rickets, cough and fever. Although several studies have proved its therapeutic effectiveness, there are very few toxicological studies on the plant. Objectives: This study was carried out to evaluate the acute and sub-chronic toxicity of the aqueous extract of G. mollis stem bark (GM in animals. Methods: In the acute study, rats were orally administrated with GM at doses of 150, 300, 600, 1200, 2400, 4800 and 9600 mg/kg to determine the oral medial lethal dose (LD50. In the chronic study, rats received three doses of GM (150, 300 and 600 mg/kg for 28 days. After the treatments, food intake, body weights, biochemical, hematological and histopathological parameters were analyzed. Results: The LD50 was estimated to be >9600 mg/kg. No significant alterations in the animal’s body weight gain, relative organs weight, serum biochemical analysis, hematological or histopathological analyses of liver, kidneys, lungs, heart and spleen were observed. Conclusions: The results of this study provided evidence that oral administration of GM at dose of 600 mg/kg is relatively safe in rats and may not exert severe toxic effects.

  16. First Chemical Evaluation and Toxicity of Casinga-cheirosa to Balb-c Male Mice

    Directory of Open Access Journals (Sweden)

    Dirce M. Estork

    2014-04-01

    Full Text Available Laetia suaveolens, known as “casinga-cheirosa”, crude extract EB719 has previously shown cytotoxic activity against prostate cancer and squamous cell carcinoma. For the first time, seven molecules were isolated from its apolar—α-tocopherol (1 and sitosterol (2—and polar—3-O-caffeoylquinic acid (3, 4-O-caffeoylquinic acid (4, 5-O-feruloylquinic acid (5, hyperoside (6, and isoquercitrin (7—fractions. Acute toxicity was determined in a two-stage experiment: (1 a reduced number of Balb-c male mice received 5000 mg/kg of EB719 to allow evaluation of general activity and other 27 parameters, plus death, up to the establishment of non-lethal dose (NLD, as well as lethal dose 50% (LD50; (2 NLD was administered and diazepam introduced as reference drug. EB719 showed LD50 = 178.0 mg/kg, and NLD 156.3 mg/kg. In stage one EB719 did not influence general activity, but provoked impairment in grasp reflexes, tail squeeze and breathing; piloerection and cyanosis were increased. In stage two, alterations occurred in auricular reflex, piloerection and breathing after diazepam administration, but not in response to EB719. Intestinal hemorrhage caused by local bleeding was observed after necropsy, and may be the main cause of animals’ death other than a systemic effect of the extract. Although the isolated compounds are biologically and pharmacologically active in both men and animal systems, it is premature to relate their occurrence in EB719 to the observed intestine hemorrhage in mice.

  17. Low-dose CT pulmonary angiography on a 15-year-old CT scanner: a feasibility study

    Directory of Open Access Journals (Sweden)

    Moritz Kaup

    2016-12-01

    Full Text Available Background Computed tomography (CT low-dose (LD imaging is used to lower radiation exposure, especially in vascular imaging; in current literature, this is mostly on latest generation high-end CT systems. Purpose To evaluate the effects of reduced tube current on objective and subjective image quality of a 15-year-old 16-slice CT system for pulmonary angiography (CTPA. Material and Methods CTPA scans from 60 prospectively randomized patients (28 men, 32 women were examined in this study on a 15-year-old 16-slice CT scanner system. Standard CT (SD settings were 100 kV and 150 mAs, LD settings were 100 kV and 50 mAs. Attenuation of the pulmonary trunk, various anatomic landmarks, and image noise were quantitatively measured; contrast-to-noise ratios (CNR and signal-to-noise ratios (SNR were calculated. Three independent blinded radiologists subjectively rated each image series using a 5-point grading scale. Results CT dose index (CTDI in the LD series was 66.46% lower compared to the SD settings (2.49 ± 0.55 mGy versus 7.42 ± 1.17 mGy. Attenuation of the pulmonary trunk showed similar results for both series (SD 409.55 ± 91.04 HU; LD 380.43 HU ± 93.11 HU; P = 0.768. Subjective image analysis showed no significant differences between SD and LD settings regarding the suitability for detection of central and peripheral PE (central SD/LD, 4.88; intra-class correlation coefficients [ICC], 0.894/4.83; ICC, 0.745; peripheral SD/LD, 4.70; ICC, 0.943/4.57; ICC, 0.919; all P > 0.4. Conclusion The LD protocol, on a 15-year-old CT scanner system without current high-end hardware or post-processing tools, led to a dose reduction of approximately 67% with similar subjective image quality and delineation of central and peripheral pulmonary arteries.

  18. Experimental Tityus serrulatus scorpion envenomation: age- and sex-related differences in symptoms and mortality in mice

    Directory of Open Access Journals (Sweden)

    Pucca MB

    2011-01-01

    Full Text Available Among the various methods for evaluating animal venom toxicity, the calculation of the median lethal dose (LD50 is the most widely used. Although different protocols can be used to calculate the LD50, the source of the venom and the method of extraction, as well as the strain, age, and sex of the animal model employed, should be taken into consideration. The objective of the present study was to evaluate the influence of sex and age on the toxicity of Tityus serrulatus scorpion venom in Swiss mice. Although the symptoms of envenomation were similar in male and female animals, female mice proved to be more resistant to the venom. In females, age had no impact on the susceptibility to scorpion envenomation. Male mice were more sensitive to T. serrulatus venom. Moreover, in males, age was an important parameter since sensitivity to the venom increased with age.

  19. Influence Analysis of Shell Material and Charge on Shrapnel Lethal Power

    Directory of Open Access Journals (Sweden)

    Wang Lin

    2015-01-01

    Full Text Available To compare the shrapnel lethal power with different shell material and charge, LS-DYNA was used to numerically simulate four kinds of shrapnel lethal power. The shell material was 58SiMn, 50SiMnVB or 40Cr, whereas the charge was RL-F. And the shell material was 58SiMn, whereas the charge was TNT. The shell rupture process and lethal power test were analyzed. The results show that, the lethal power of RL-F charge increase by 25%, 45%, 14% compared with the TNT charge, whereas the shell material was 58SiMn, 50SiMnVB, 40Cr. And then the guarantee range and lethal power can be improved by using the high explosive and changing shell material, whereas the projectile shape coefficient is invariable.

  20. Radiosensitivity of amphibia

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, S [National Inst. of Radiological Sciences, Chiba (Japan)

    1975-04-01

    Radiosensitivity (semi-lethal dose) and the damages of radiation in the amphibia were studied by /sup 3/H-TdR from the standpoint of cellular kinetics. The cell mitosis cycle of the amphibia required a long time. The functional cell regeneration and the physiological function of the cell were slower than in mice. The reason for the low radiosensitivity of the amphibia was discussed relative to the environmental factor of temperature. Because the amphibia change body temperature according to environmental temperature, the danger of radiation damage, the actual lethal dose and the period of survival were influenced by the environmental temperature. Acute radiation danger to amphibia was essentially the same as the danger to mammalia, both young and old. LD/sub 50/ irradiation effects varied among the species. The cell regeneration, turn over, and the mitosis in the amphibia, were affected by environmental temperature, however, the courses proceeded slower than those of the mammalia. Therefore, the question remains, whether the comparison of the radiosensitivities of amphibia with other classes of animal by LDsub(50/30) irradiation was appropriate.

  1. Disinfestation of Averrhoa carambola infested with Anastrepha obliqua (Macquart, 1835) (Diptera - Tephritidae) using gamma radiation

    International Nuclear Information System (INIS)

    Arthur, V.; Wiendl, F.M.

    1994-01-01

    The disinfestation dose of gamma radiation in Averrhoa carambola infested with larvae of Anastrepha obliqua was determined. Fruits were collected in the field, each having about 11 larvae in the last instar. Fruits were irradiated with the following ganna radiation doses: 0 (control), 50, 150, 300, 600 and 900 Gy. Each treatment consisted of 9 fruits (3 replications) giving the amount of 99 larvae for each treatment. After irradiation the fruits were kept in a climatic chamber with the temperature adjusted to 25± 5 0 C and relative humidity of 70± 5 0 C, until larvae left the fruit and became transformed into pupae and adults. The lethal dose (LD 100 ) of gamma radiation for larvae in the fuits was 600 Gy and the dose of 50 Gy inhibited completely the total emergency of adults. (author). 19 refs, 1 figs, 1 tab

  2. Disinfestation of Averrhoa carambola infested with Anastrepha obliqua (Macquart, 1835) (Diptera - Tephritidae) using gamma radiation; Desinfestacao de Averrhoa carambola infestada por Anastrepha obliqua (Macquart, 1835) (Diptera - Tephritidae) atraves de radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, V.; Wiendl, F.M. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1994-05-01

    The disinfestation dose of gamma radiation in Averrhoa carambola infested with larvae of Anastrepha obliqua was determined. Fruits were collected in the field, each having about 11 larvae in the last instar. Fruits were irradiated with the following ganna radiation doses: 0 (control), 50, 150, 300, 600 and 900 Gy. Each treatment consisted of 9 fruits (3 replications) giving the amount of 99 larvae for each treatment. After irradiation the fruits were kept in a climatic chamber with the temperature adjusted to 25{+-} 5{sup 0} C and relative humidity of 70{+-} 5{sup 0} C, until larvae left the fruit and became transformed into pupae and adults. The lethal dose (LD{sub 100}) of gamma radiation for larvae in the fuits was 600 Gy and the dose of 50 Gy inhibited completely the total emergency of adults. (author). 19 refs, 1 figs, 1 tab.

  3. Development of Plant Mutation Breeding Techniques and Mutants Using by Ion Beam

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Si Yong; Song, Hi Sup; Park, In Sook; Kim, Dong Sub; Lee, Hye Jeong

    2005-06-15

    In recent, Japanese scientists have revealed that high liner energy transfer (LET) heavy-ion beams have relative high biological effectiveness (RBE) and seem to be more effective for induced plant mutation than low LET radiation i.e., X-rays, gamma rays and electrons. This study was conducted to develop basic induced mutation techniques of ion-beam using the MC-50 cyclotron (50MeV) at the Korea Institute of Radiological and Medical Science. For the irradiation of ion-beam, not only dry seeds of Arabidopsis, tabacco, Zosiagrass, radish, rice and perilla were packed with thin plastic film to be a monolayer of seeds for homogenous irradiation, but also calli of Zosiagrass and Chrysanthemum were placed in the plastic petridish (diameter 5.5cm) with agar medium. They were irradiated with a proton beam of MC-50 cyclotron with various dose ranges of 10 to 5000Gy depend on plant materials and then measured germination rate and early growth of M1 plants. Arabidopsis, tabacco, and Zosiagrass showed little inhibition of germination and early growth at doses tested over than 1000 Gy. In particular, Arabidopsis showed less growth inhibition than 50 % even at dose of 5000Gy. On the other hand, radish, perilla and rice were not only sensitively inhibited at the lower doses, but also linearly decreased with accordance with the increasing irradiation dose. The lethal dose 50 (LD50) for two cultivars of perilla was estimated to be at approximately 25-30Gy. All M1 plants of rice did not growth over than 500Gy. These results indicate that the significant difference in sensitivity or in LD50 to irradiation of MC-50 proton beam was observed among plant species and materials.

  4. Stress and radioresistance (genetic aspects)

    International Nuclear Information System (INIS)

    Lyubaschevsky, N.M.; Grigorkina, E.B.

    1995-01-01

    Inbred mice and randomly bred stock were exposed to long-term adrenaline and hypothermia stress effects for unification of their functional status, followed by acute total gamma irradiation by equal-effect doses (LD 50/30 ). The significant reduction of lethality distribution in inbred mice after combined stress and radiation effects was observed. The spread of lethality in random bred stock was increased as compared to the control group. The post-irradiation mortality in experimental animals differed only slightly from the values in the control groups. Conclusions are drawn about the principal meaning of genotype in radiosensitivity, about the role of an organism's functional status in determination of death date and about the possible epigenetic structuralisation of linear mice by radioresistance. (Author)

  5. The relative biological effectiveness (RBE) of high-energy electrons, x-rays and Co-60 gamma-rays

    International Nuclear Information System (INIS)

    Kiyono, Kunihiro

    1974-01-01

    Linac (Mitsubishi-Shimizu 15 MeV medical linear accelerator) electron beams with actual generated energies of 8, 10, 12 and 15 MeV were compared with X-ray beams having energies of 8 and 10 MV. The RBE values were calculated from 50 percent hatch-ability (LD 50 ) in silk-worm embryos, 30-days lethality (LDsub(50/30)) in ddY mice, and mean lethal dose (Do) in cultured mouse YL cells or human FL cells. To estimate the RBE in clinical experiments, LRD (leukocyte reduction dose) value was calculated for each patient irradiated on the chest or lumbar vertebrae. It was concluded that there is little difference in practical significance between 8 to 10 MV X-rays and 8 to 15 MeV electrons, and that the biological effects of Linac radiations are about 90 to 100 percent of the effect of 60 Co gamma rays. The RBE values gradually decreased, contrary to the elevation of energy between 8 and 15 MeV for electrons and between 8 and 10 MV for X-rays. These values were compared with those of earlier reviews of work in this field, and were briefly discussed. (Evans, J.)

  6. Cheap streak camera based on the LD-S-10 intensifier tube

    Science.gov (United States)

    Dashevsky, Boris E.; Krutik, Mikhail I.; Surovegin, Alexander L.

    1992-01-01

    Basic properties of a new streak camera and its test results are reported. To intensify images on its screen, we employed modular G1 tubes, the LD-A-1.0 and LD-A-0.33, enabling magnification of 1.0 and 0.33, respectively. If necessary, the LD-A-0.33 tube may be substituted by any other image intensifier of the LDA series, the choice to be determined by the size of the CCD matrix with fiber-optical windows. The reported camera employs a 12.5- mm-long CCD strip consisting of 1024 pixels, each 12 X 500 micrometers in size. Registered radiation was imaged on a 5 X 0.04 mm slit diaphragm tightly connected with the LD-S- 10 fiber-optical input window. Electrons escaping the cathode are accelerated in a 5 kV electric field and focused onto a phosphor screen covering a fiber-optical plate as they travel between deflection plates. Sensitivity of the latter was 18 V/mm, which implies that the total deflecting voltage was 720 V per 40 mm of the screen surface, since reversed-polarity scan pulses +360 V and -360 V were applied across the deflection plate. The streak camera provides full scan times over the screen of 15, 30, 50, 100, 250, and 500 ns. Timing of the electrically or optically driven camera was done using a 10 ns step-controlled-delay (0 - 500 ns) circuit.

  7. LD5o of the bacteria Aeromonas hydrophila to matrinxã, Brycon amazonicus DL5o da bactéria Aeromonas hydrophila para o matrinxã, Brycon amazonicus

    Directory of Open Access Journals (Sweden)

    Sarah Ragonha de Oliveira

    2011-01-01

    Full Text Available In order to determine the lethal dose (96-h LD50 of the bacteria Aeromonas hydrophila to matrinxã, Brycon amazonicus, to be applied in challenge tests, 90 fish (63.23 ± 6.39 g were divided into five treatments, with different bacterial solutions: T1 - Control (0.9% NaCl saline solution; T2 (4 x 10(11 cells/ mL; T3 (5 x 10(11 cells/ mL; T4 (1.36 x 10(12 cells/ mL and T5 (3.06 x 10(12 cells/ mL. Fish were previously anesthetized with benzocaine (60 mg L-1, inoculated in the peritoneal cavity with the bacterial suspensions and then distributed into fifteen 80-L test chambers, where the water variables were monitored and fish mortality was observed. The experiment was randomly designed in three replicates and the 96-h LD50 was estimated according to the trimmed Spearman-Karber method. Water quality variables remained within adequate ranges for fish health and performance. Fish mortality rate increased with the bacterial concentrations of A. hydrophila (T1 = 0%; T2 = 16.66%; T3 = 44.44%; T4 = 72.22% and T5 = 100%, and the first mortalities were observed after 57 h, although the signs of the bacterial infection were already observed 24 h after the inoculation. The results indicate that the 96-h LD50 value of A. hydrophila to matrinxã is 6.66 x 10(11 cells/ mL.Para determinar a dose letal (DL50 96-h da bactéria Aeromonas hydrophila para o matrinxã, Brycon amazonicus, com aplicabilidade para testes de desafio, foram utilizados 90 peixes (63,23 ± 6,39 g, divididos em cinco tratamentos, com diferentes soluções bacterianas: T1 - Controle (solução salina 0,9% NaCl; T2 (4 x 10(11 células/ mL; T3 (5 x 10(11 células/ mL-1; T4 (1,36 x 10(12 células/mL-1 e T5 (3,06 x 10(12 células/ mL-1. Os peixes foram previamente anestesiados com benzocaína (60 mg L-1, inoculados na cavidade peritoneal com as suspensões bacterianas e distribuídos em 15 aquários de vidro de 80 L de capacidade, com aeração constante. O experimento teve duração de 96 h, no

  8. Dose Response for Monokaryon mycelium of Pleurotus pulmonarius After Acute Gamma Radiation

    International Nuclear Information System (INIS)

    Wan Safina Wan Abdul Razak; Azhar Mohamad; Nie, H.J.

    2016-01-01

    Pleurotus pulmonarius is locally known as Grey oyster. The species is popular and widely cultivated throughout the world mostly in Asia Europe as their simple and low cost production technology and higher biological efficiency. Mutation induction is an alternative ways for improving available commercial strain for better quality traits. Dose response is important in evaluating effects of mutagenesis via acute gamma radiation. Monokaryon mycelium of Pleurotus pulmonarius was exposed to acute gamma radiation ranged from 0 Gy, 0.1 kGy, 0.2 kGy, 0.3 kGy, 0.4 kGy, 0.5 kGy, 0.6 kGy, 0.7 kGy, 0.8 kGy, 0.9 kGy, 1.0 kGy, 1.5 Gy, 2.0 kGy, 3.0 kGy and 4.0 kGy at dose rate 0.013 kGy/ min. growth performance was measured at 2 days interval to get the LD_5_0. Increasing of the irradiation dose found to decrease the growth performance of the monokaryon mycelium. LD_5_0 was revealed at 1.56 kGy for mono karyon mycelium. Discoveries of the works are important for the improvement of Pleurotus species via acute gamma radiation and benefiting to growers and mushroom industries. (author)

  9. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, M; Guenet, J -L; Maas, J; Nizza, P

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

  10. Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P

    1966-05-01

    Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

  11. Resveratrol radiomodifier effect on Danio rerio embriolarval assay

    Energy Technology Data Exchange (ETDEWEB)

    Damasceno, Kelme C.; Mamede, Fernanda C.S.; Cavalcante, Adriana K.; Rogero, Sizue O.; Rogero, José R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ferreira, Monica L., E-mail: kelmecardoso@gmail.com, E-mail: monica.lopesferreira@butantan.gov.br [Instituto Butantan, São Paulo, SP (Brazil)

    2017-07-01

    The ionizing radiation can cause fatal damages to cells by the direct interaction with DNA and RNA or a series of toxic reactions occasioning chemical and biological changes. There are compounds with radioprotective potential, like resveratrol. For use these compounds it is necessary to know their toxicity and interaction with the organism. Resveratrol is a substance found in peanuts, grapes and wine and its production occurs in plants as a response to physical, chemical and biological stress. Some studies have indicated that it has many health benefits. Danio rerio (zebrafish) is a vertebrate animal and has become the model of several studies related to human diseases, due to its genomes similarity of 70 %, rapid embryonic development and the transparency of the eggs, which make it possible to observe the effects during the test period. The aim of the present study was to verify the resveratrol radiomodifier effect on zebrafish during the embryolarval development by modified Fish Embryo Acute Toxicity (FET) based on OECD236 and the obtained lethal concentration of resveratrol (LC50) was 66.9 mg.L{sup -1}. Before, to understand the effects of radiation, was carried out the gamma radiation lethal dose (LD50) assay and the LD50 was 25 Gy. With these results the project will continue later to finish the study of the radiomodifier effect of resveratrol in the presence of gamma radiation. (author)

  12. Resveratrol radiomodifier effect on Danio rerio embriolarval assay

    International Nuclear Information System (INIS)

    Damasceno, Kelme C.; Mamede, Fernanda C.S.; Cavalcante, Adriana K.; Rogero, Sizue O.; Rogero, José R.; Ferreira, Monica L.

    2017-01-01

    The ionizing radiation can cause fatal damages to cells by the direct interaction with DNA and RNA or a series of toxic reactions occasioning chemical and biological changes. There are compounds with radioprotective potential, like resveratrol. For use these compounds it is necessary to know their toxicity and interaction with the organism. Resveratrol is a substance found in peanuts, grapes and wine and its production occurs in plants as a response to physical, chemical and biological stress. Some studies have indicated that it has many health benefits. Danio rerio (zebrafish) is a vertebrate animal and has become the model of several studies related to human diseases, due to its genomes similarity of 70 %, rapid embryonic development and the transparency of the eggs, which make it possible to observe the effects during the test period. The aim of the present study was to verify the resveratrol radiomodifier effect on zebrafish during the embryolarval development by modified Fish Embryo Acute Toxicity (FET) based on OECD236 and the obtained lethal concentration of resveratrol (LC50) was 66.9 mg.L -1 . Before, to understand the effects of radiation, was carried out the gamma radiation lethal dose (LD50) assay and the LD50 was 25 Gy. With these results the project will continue later to finish the study of the radiomodifier effect of resveratrol in the presence of gamma radiation. (author)

  13. Passive dosing of polycyclic aromatic hydrocarbon (PAH) mixtures to terrestrial springtails: linking mixture toxicity to chemical activities, equilibrium lipid concentrations, and toxic units.

    Science.gov (United States)

    Schmidt, Stine N; Holmstrup, Martin; Smith, Kilian E C; Mayer, Philipp

    2013-07-02

    A 7-day mixture toxicity experiment with the terrestrial springtail Folsomia candida was conducted, and the effects were linked to three different mixture exposure parameters. Passive dosing from silicone was applied to tightly control exposure levels and compositions of 12 mixture treatments, containing the polycyclic aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. Springtail lethality was then linked to sum chemical activities (∑a), sum equilibrium lipid concentrations (∑C(lipid eq.)), and sum toxic units (∑TU). In each case, the effects of all 12 mixture treatments could be fitted to one sigmoidal exposure-response relationship. The effective lethal chemical activity (La50) of 0.027 was well within the expected range for baseline toxicity of 0.01-0.1. Linking the effects to the lipid-based exposure parameter yielded an effective lethal concentration (LC(lipid eq 50)) of 133 mmol kg(-1) lipid in good correspondence with the lethal membrane burden for baseline toxicity (40-160 mmol kg(-1) lipid). Finally, the effective lethal toxic unit (LTU50) of 1.20 was rather close to the expected value of 1. Altogether, passive dosing provided tightly controlled mixture exposure in terms of both level and composition, while ∑a, ∑C(lipid eq.), and ∑TU allowed baseline toxicity to be linked to mixture exposure.

  14. Effect of large doses of 131I-19-iodocholesterol on metapyralone-induced adrenal cortical hyperplasia in dogs

    International Nuclear Information System (INIS)

    Anderson, B.G.; Beierwaltes, W.H.; Nishiyama, R.H.; Ice, R.D.

    1975-01-01

    The potential use of 131 I-19-iodocholesterol to treat ACTH excess Cushing's disease was evaluated in the dog. Three normal female dogs were given LD 50 radiation doses of 131 I-19-iodocholesterol without producing gross or histopathologically demonstrable change of the adrenals at autopsy 3 months later. The adrenal cortices of three dogs were made hyperplastic (to simulate the adrenal cortex in Cushing's disease) with ACTH and three with Metapyralone. In addition these six dogs were given LD 50 doses of 131 I-19-iodocholesterol. Three months after treatment, the adrenal glands of the ACTH-treated dogs were not enlarged, the cortex was thicker than normal, and there were no changes attributable to irradiation. At 3 months, the Metapyralone-treated dogs had enlarged adrenals, widening of the adrenal cortex, and no necrosis or other changes attributable to irradiation. It is concluded that a therapeutic trial of 131 I-19-iodocholesterol in the treatment of Cushing's disease is not indicated. (auth)

  15. Improving Test-Taking Skills of LD Adolescents.

    Science.gov (United States)

    Markel, Geraldine

    1981-01-01

    A multicomponent model to improve test taking skills of learning disabled (LD) adolescents is proposed to encourage anxiety management, problem solving skills, assertiveness, study skills, and student confidence and control. The role of the LD consultant in this process is described. (CL)

  16. Chronic Exposure of Corals to Fine Sediments: Lethal and Sub-Lethal Impacts

    Science.gov (United States)

    Flores, Florita; Hoogenboom, Mia O.; Smith, Luke D.; Cooper, Timothy F.; Abrego, David; Negri, Andrew P.

    2012-01-01

    Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS) for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata) more than the upright branching species (Acropora millepora). The lowest sediment treatments that caused full colony mortality were 30 mg l−1 TSS (25 mg cm−2 day−1) for M. aequituberculata and 100 mg l−1 TSS (83 mg cm−2 day−1) for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue. PMID:22662225

  17. Chronic exposure of corals to fine sediments: lethal and sub-lethal impacts.

    Directory of Open Access Journals (Sweden)

    Florita Flores

    Full Text Available Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata more than the upright branching species (Acropora millepora. The lowest sediment treatments that caused full colony mortality were 30 mg l(-1 TSS (25 mg cm(-2 day(-1 for M. aequituberculata and 100 mg l(-1 TSS (83 mg cm(-2 day(-1 for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue.

  18. Myrtaceae Plant Essential Oils and their β-Triketone Components as Insecticides against Drosophila suzukii

    Directory of Open Access Journals (Sweden)

    Chung Gyoo Park

    2017-06-01

    Full Text Available Spotted wing drosophila (SWD, Drosophila suzukii (Matsumura, Diptera: Drosophilidae is recognized as an economically important pest in North America and Europe as well as in Asia. Assessments were made for fumigant and contact toxicities of six Myrtaceae plant essential oils (EOs and their components to find new alternative types of insecticides active against SWD. Among the EOs tested, Leptospermum citratum EO, consisting mainly of geranial and neral, exhibited effective fumigant activity. Median lethal dose (LD50; mg/L values of L. citratum were 2.39 and 3.24 for males and females, respectively. All tested EOs except Kunzea ambigua EO exhibited effective contact toxicity. LD50 (µg/fly values for contact toxicity of manuka and kanuka were 0.60 and 0.71, respectively, for males and 1.10 and 1.23, respectively, for females. The LD50 values of the other 3 EOs-L. citratum, allspice and clove bud were 2.11–3.31 and 3.53–5.22 for males and females, respectively. The non-polar fraction of manuka and kanuka did not show significant contact toxicity, whereas the polar and triketone fractions, composed of flavesone, isoleptospermone and leptospermone, exhibited efficient activity with the LD50 values of 0.13–0.37 and 0.22–0.57 µg/fly for males and females, respectively. Our results indicate that Myrtaceae plant EOs and their triketone components can be used as alternatives to conventional insecticides.

  19. Quantitative aspects of repair of potentially lethal damage in mammalian cells

    International Nuclear Information System (INIS)

    Iliakis, G.; Pohlit, W.

    1979-01-01

    Stationary cultures of Ehrlich ascites tumour cells were irradiated with X-rays and then immediately or after a time interval tsub(rep) plated to measure the survival. The increase in survival observed after delayed plating was interpreted as repair of potentially lethal damage. A cybernetic model was used to analyse these data. Three states of damage were assumed for the cells. In state A the cells could grow to macrocolonies, in state B the cells suffered potentially lethal damage and could grow to macrocolonies only if they were allowed to repair the damage and in state C the cells were lethally damaged. A method of deriving the values of the parameters of the model from the experimental data was given. The dependence of the reaction rate constant of the repair potentially lethal damage on the dose D was used to derive a possible mechanism for the production of the shoulder in the dose effect curve. Finally this model was compared with other models of radiation action in living cells. (author)

  20. Radiation-induced rectal complications are not influenced by age: a dose fractionation study in the rat.

    Science.gov (United States)

    van den Aardweg, Gerard J M J; Olofsen-van Acht, Manouk J J; van Hooije, Christel M C; Levendag, Peter C

    2003-05-01

    Radiation-induced complications of the rectum are an important dose-limiting factor in radiotherapy of pelvic malignancies. In general, animal studies demonstrated no differences in acute and late normal tissue toxicity with age, but little is known about rectal complications in relation to age. For this purpose, an extensive histological and dose fractionation study was carried out on the rectum of young (12 weeks) and older (77-80 weeks) rats. In this paper, the results of dose fractionation are presented in relation to age at the time of irradiation. Young and older animals were irradiated with single and fractionated doses. After irradiation, rectal complications could lead to occlusion and stenosis, eventually resulting in the clinical symptoms of a megacolon and a possible fistula. For each dose group, cumulative survival rates were obtained with Kaplan-Meier analysis, from which dose-effect curves and the associated LD(50) values for a megacolon/fistula were calculated. The majority of responders died between 8 and 24 weeks after irradiation, irrespective of age. For both age groups, only the fractionation data showed a reduction in the mean latency with increasing dose. In the older age group, 39% of the responders developed a fistula compared to 26% for the younger animals. The LD(50) values increased from around 30 Gy after single doses to nearly 65 Gy after 10 fractions. The increases in LD(50) values with the number of fractions were independent of the age of the rats. For each of the dose fractionation schedules, log-rank testing indicated no significant differences in cumulative survival rates between younger and older animals (P > 0.10). The high alpha/beta ratios obtained for both the young and older animals strongly suggested that the late rectal complications were a consequence of early epithelial injury. Associated histological findings indicated that blood vessel damage, which was already evident at a high incidence at 4 weeks after irradiation

  1. Experimental study on central nervous toxicity of 'misonidazole' a hypoxic cell radiosensitizer

    International Nuclear Information System (INIS)

    Takahashi, Iku

    1981-01-01

    'Misonidazole', a radiosensitizer for hypoxic cells is expected to be applied to the treatment of malignant tumors, but its side effect becomes a subject of study, because its effective dose is close to its lethal dose. The auther performed experiments with mice on the central nervous toxicity, which is the most lethal of the side effects of Misonidazole, with the following results; 1. The abrupt death seen after the administration of a large dose of Misonidazole was attributable to the central nervous toxicity. LD 50 for d.d. strain mouse was 1.55 mg per body weight g. 2. The used mice always developed convulsion before death. But the administration of anticonvulsant failed to free them from death. 3. Autopsy findings were such abnormal ones as the degeneration and exfoliation of nerve cells and diapedetic focus. After sacrifice, however, no findings indicative of disturbance of central nerve could be detected. 4. Misonidazole, even in a small divided dose, left intracerebral retention, though slightly, indicating that its accumulation in the brain would be increased with increase in the dose. 5. The disturbance of central nerve was not exacerbated by the whole brain irradiation with Misonidazole. (author)

  2. Pedigree analyses of yeast cells recovering from DNA damage allow assignment of lethal events to individual post-treatment generations

    International Nuclear Information System (INIS)

    Klein, F.; Karwan, A.; Wintersberger, U.

    1990-01-01

    Haploid cells of Saccharomyces cerevisiae were treated with different DNA damaging agents at various doses. A study of the progeny of individual such cells allowed the assignment of lethal events to distinct post treatment generations. By microscopically inspecting those cells which were not able to form visible colonies the authors could discriminate between cells dying from immediately effective lethal hits and those generating microcolonies probably as a consequence of lethal mutation(s). The experimentally obtained numbers of lethal events were mathematically transformed into mean probabilities of lethal fixations at taking place in cells of certain post treatment generations. Such analyses give detailed insight into the kinetics of lethality as a consequence of different kinds of DNA damage. For example, X-irradiated cells lost viability mainly by lethal hits, only at a higher dose also lethal mutations fixed in the cells that were in direct contact with the mutagen, but not in later generations, occurred. Ethyl methanesulfonate (EMS)-treated cells were hit by 00-fixations in a dose dependent manner. The distribution of all sorts of lethal fixations taken together, which occurred in the EMS-damaged cell families, was not random. For comparison analyses of cells treated with methyl methanesulfonate, N-methyl-N'-nitro-N-nitrosoguanidine and nitrous acid are also reported

  3. Detoxification of Salmonella typhimurium lipopolysaccharide by ionizing radiation.

    Science.gov (United States)

    Previte, J J; Chang, Y; el-Bisi, H M

    1967-05-01

    The efficiency of ionizing radiation in detoxifying the lethal determinant(s) of the lipopolysaccharide (LPS) of Salmonella typhimurium, S. enteritidis, and Escherichia coli in aqueous solution and associated with heat-killed S. typhimurium cells in suspension decreased with doses above 1 Mrad. The 50% end point of inactivation was more than 7.0 Mrad for heat-killed salmonellae and 4.8, 4.5, and 1.0 Mrad for the LPS of S. typhimurium, S. enteritidis, and E. coli, respectively. After exposure to 20 Mrad, S. typhimurium LPS retained a small portion of its lethal properties although the ld(50) was much greater than 9.5 mg per 20-g mouse. However, at -184 C, no inactivation of the lethal determinant(s) occurred after exposure to as much as 20 Mrad. This demonstrated the significance of the indirect effect and the mobility and formation of free radicals. At 22 C, the optical density at 400 mmu increased and the pH decreased with increasing radiation dose, but no qualitative changes were observed in the infrared spectrum. No change was observed in the pyrogenicity of S. typhimurium LPS; a slight decrease in antigenicity was revealed when 6 days, but not when 1 day, elapsed between vaccination and challenge in the mouse protection test. The results were interpreted as evidence of the existence of two or more lethal and antigenic determinants. The differential effect of radiation on these properties and on the pyrogenic component(s) probably are indicative of separate functional sites for lethal, antigenic, and pyrogenic activities.

  4. LD, interpersonal understanding, and social behavior in the classroom.

    Science.gov (United States)

    Kravetz, S; Faust, M; Lipshitz, S; Shalhav, S

    1999-01-01

    This study used Baron and Kenny's (1986) criteria for mediation to investigate the extent to which interpersonal understanding mediates the relation between learning disabilities (LD) and social adaptation in the classroom. Twenty-two children with and 22 children without a diagnosis of LD completed a semistructured developmental clinical interview measure of interpersonal understanding. They were also rated by their fourth- and fifth-grade teachers on a measure of social adaptation in the classroom. Interpersonal understanding and social adaptation in the classroom were found to be positively correlated. Children with LD exhibited less interpersonal understanding and social adaptation. Although this group difference on social adaptation was greatly reduced when interpersonal understanding was statistically controlled, it remained statistically significant. These results suggest that reduced social adaptation in the classroom and lower interpersonal understanding are both associated with a diagnosis of LD. However, they do not conclusively support the claim that interpersonal understanding mediates the relation between LD and social adaptation. Thus, whether the social difficulties of people with LD stem from the same complex phenomena that produce these people's learning problems remains an open question.

  5. A novel highly reproducible and lethal nonhuman primate model for orthopox virus infection.

    Directory of Open Access Journals (Sweden)

    Marit Kramski

    Full Text Available The intentional re-introduction of Variola virus (VARV, the agent of smallpox, into the human population is of great concern due its bio-terroristic potential. Moreover, zoonotic infections with Cowpox (CPXV and Monkeypox virus (MPXV cause severe diseases in humans. Smallpox vaccines presently available can have severe adverse effects that are no longer acceptable. The efficacy and safety of new vaccines and antiviral drugs for use in humans can only be demonstrated in animal models. The existing nonhuman primate models, using VARV and MPXV, need very high viral doses that have to be applied intravenously or intratracheally to induce a lethal infection in macaques. To overcome these drawbacks, the infectivity and pathogenicity of a particular CPXV was evaluated in the common marmoset (Callithrix jacchus.A CPXV named calpox virus was isolated from a lethal orthopox virus (OPV outbreak in New World monkeys. We demonstrated that marmosets infected with calpox virus, not only via the intravenous but also the intranasal route, reproducibly develop symptoms resembling smallpox in humans. Infected animals died within 1-3 days after onset of symptoms, even when very low infectious viral doses of 5x10(2 pfu were applied intranasally. Infectious virus was demonstrated in blood, saliva and all organs analyzed.We present the first characterization of a new OPV infection model inducing a disease in common marmosets comparable to smallpox in humans. Intranasal virus inoculation mimicking the natural route of smallpox infection led to reproducible infection. In vivo titration resulted in an MID(50 (minimal monkey infectious dose 50% of 8.3x10(2 pfu of calpox virus which is approximately 10,000-fold lower than MPXV and VARV doses applied in the macaque models. Therefore, the calpox virus/marmoset model is a suitable nonhuman primate model for the validation of vaccines and antiviral drugs. Furthermore, this model can help study mechanisms of OPV pathogenesis.

  6. Comparative toxicity and efficacy of engineered anthrax lethal toxin variants with broad anti-tumor activities.

    Science.gov (United States)

    Peters, Diane E; Hoover, Benjamin; Cloud, Loretta Grey; Liu, Shihui; Molinolo, Alfredo A; Leppla, Stephen H; Bugge, Thomas H

    2014-09-01

    We have previously designed and characterized versions of anthrax lethal toxin that are selectively cytotoxic in the tumor microenvironment and which display broad and potent anti-tumor activities in vivo. Here, we have performed the first direct comparison of the safety and efficacy of three engineered anthrax lethal toxin variants requiring activation by either matrix-metalloproteinases (MMPs), urokinase plasminogen activator (uPA) or co-localized MMP/uPA activities. C57BL/6J mice were challenged with six doses of engineered toxins via intraperitoneal (I.P.) or intravenous (I.V.) dose routes to determine the maximum tolerated dose for six administrations (MTD6) and dose-limiting toxicities. Efficacy was evaluated using the B16-BL6 syngraft model of melanoma; mice bearing established tumors were treated with six I.P. doses of toxin and tumor measurements and immunohistochemistry, paired with terminal blood work, were used to elaborate upon the anti-tumor mechanism and relative efficacy of each variant. We found that MMP-, uPA- and dual MMP/uPA-activated anthrax lethal toxins exhibited the same dose-limiting toxicity; dose-dependent GI toxicity. In terms of efficacy, all three toxins significantly reduced primary B16-BL6 tumor burden, ranging from 32% to 87% reduction, and they also delayed disease progression as evidenced by dose-dependent normalization of blood work values. While target organ toxicity and effective doses were similar amongst the variants, the dual MMP/uPA-activated anthrax lethal toxin exhibited the highest I.P. MTD6 and was 1.5-3-fold better tolerated than the single MMP- and uPA-activated toxins. Overall, we demonstrate that this dual MMP/uPA-activated anthrax lethal toxin can be administered safely and is highly effective in a preclinical model of melanoma. This modified bacterial cytotoxin is thus a promising candidate for further clinical development and evaluation for use in treating human cancers. Published by Elsevier Inc.

  7. Resistance to pyrethroid insecticides in house flies, Musca domestica L., (Diptera: Muscidae) collected from urban areas in Punjab, Pakistan.

    Science.gov (United States)

    Khan, Hafiz Azhar Ali; Akram, Waseem; Fatima, Ammara

    2017-12-01

    House flies are one of the major public health pests in urban settings. People usually use insecticides containing pyrethroids for the management of house flies; however, there is a lack of information on pyrethroid resistance in house flies from urban areas. In the present study, resistance to four pyrethroids (beta-cyfluthrin, deltamethrin, permethrin, transfluthrin) was assessed in house flies collected from urban areas of Punjab, Pakistan. Significant levels of resistance to all the pyrethroids were found in different strains of house flies. The resistance ratios (RRs) at the median lethal dose (LD 50 ) level were in the range of 5.25- to 11.02-fold for beta-cyfluthrin, 7.22- to 19.31-fold for deltamethrin, 5.36- to 16.04-fold for permethrin, and 9.05- to 35.50-fold for transfluthrin. Pairwise comparison of the log LD 50 s revealed a highly significant correlation (p house flies from urban areas of Punjab. Regular resistance monitoring surveys and integrated approaches for the management of house flies are needed to retain the efficacy of these insecticides for a longer period of time.

  8. Differential susceptibility of primary cultured human skin cells to hypericin PDT in an in vitro model.

    Science.gov (United States)

    Popovic, A; Wiggins, T; Davids, L M

    2015-08-01

    Skin cancer is the most common cancer worldwide, and its incidence rate in South Africa is increasing. Photodynamic therapy (PDT) has been shown to be an effective treatment modality, through topical administration, for treatment of non-melanoma skin cancers. Our group investigates hypericin-induced PDT (HYP-PDT) for the treatment of both non-melanoma and melanoma skin cancers. However, a prerequisite for effective cancer treatments is efficient and selective targeting of the tumoral cells with minimal collateral damage to the surrounding normal cells, as it is well established that cancer therapies have bystander effects on normal cells in the body, often causing undesirable side effects. The aim of this study was to investigate the cellular and molecular effects of HYP-PDT on normal primary human keratinocytes (Kc), melanocytes (Mc) and fibroblasts (Fb) in an in vitro tissue culture model which represented both the epidermal and dermal cellular compartments of human skin. Cell viability analysis revealed a differential cytotoxic response to a range of HYP-PDT doses in all the human skin cell types, showing that Fb (LD50=1.75μM) were the most susceptible to HYP-PDT, followed by Mc (LD50=3.5μM) and Kc (LD50>4μM HYP-PDT) These results correlated with the morphological analysis which displayed distinct morphological changes in Fb and Mc, 24h post treatment with non-lethal (1μM) and lethal (3μM) doses of HYP-PDT, but the highest HYP-PDT doses had no effect on Kc morphology. Fluorescent microscopy displayed cytoplasmic localization of HYP in all the 3 skin cell types and additionally, HYP was excluded from the nuclei in all the cell types. Intracellular ROS levels measured in Fb at 3μM HYP-PDT, displayed a significant 3.8 fold (phuman skin cells thus highlighting the efficacy and indeed, the potential bystander effect of if administered in vivo. This study contributes toward our knowledge of the cellular response of the epidermis to photodynamic therapies and

  9. Adaptive iterative dose reduction (AIDR) 3D in low dose CT abdomen-pelvis: Effects on image quality and radiation exposure

    International Nuclear Information System (INIS)

    Ang, W C; Hashim, S; Karim, M K A; Bahruddin, N A; Salehhon, N; Musa, Y

    2017-01-01

    The widespread use of computed tomography (CT) has increased the medical radiation exposure and cancer risk. We aimed to evaluate the impact of AIDR 3D in CT abdomen-pelvic examinations based on image quality and radiation dose in low dose (LD) setting compared to standard dose (STD) with filtered back projection (FBP) reconstruction. We retrospectively reviewed the images of 40 patients who underwent CT abdomen-pelvic using a 80 slice CT scanner. Group 1 patients ( n =20, mean age 41 ± 17 years) were performed at LD with AIDR 3D reconstruction and Group 2 patients ( n =20, mean age 52 ± 21 years) were scanned with STD using FBP reconstruction. Objective image noise was assessed by region of interest (ROI) measurements in the liver and aorta as standard deviation (SD) of the attenuation value (Hounsfield Unit, HU) while subjective image quality was evaluated by two radiologists. Statistical analysis was used to compare the scan length, CT dose index volume (CTDI vol ) and image quality of both patient groups. Although both groups have similar mean scan length, the CTDI vol significantly decreased by 38% in LD CT compared to STD CT ( p <0.05). Objective and subjective image quality were statistically improved with AIDR 3D ( p <0.05). In conclusion, AIDR 3D enables significant dose reduction of 38% with superior image quality in LD CT abdomen-pelvis. (paper)

  10. LD pumped Nd: YLF amplification technology

    International Nuclear Information System (INIS)

    Qin Xingwu; Li Mingzhong; Luo Yiming; Sui Zhan; Ding Lei; Liang Yue; Zhao Runchang; Chen Lianming

    2003-01-01

    A Ring-LD-pumped Nd: YLF laser amplifier system is theoretically and experimentally discussed. A structure of off-axes double passes amplifier is used. The results of experiment shown that 109 mJ output energy with a net gain of 1115 is obtained under 150 μJ input energy; a compact side-pumped structure is used to obtain a high transferring efficiency of LD array, 1.01 J output energy is achieved at 1053 nm. (authors)

  11. Toxicity status and antiulcerative potential of Sansevieria trifasciata leaf extract in Wistar rats.

    Science.gov (United States)

    Ighodaro, Osasenaga Macdonald; Adeosun, Abiola Muhammad; Ojiko, Barinemene Francis; Akorede, Abeeb Taiwo; Fuyi-Williams, Oyindamola

    2017-01-01

    The lethal dose 50% (LD 50 ) and antiulcerative potentials of Sansevieria trifasciata (ST) leaf extract were investigated. LD 50 was determined through two routes of administration (intraperitoneal [i.p] and oral [p.o]) using the method of Lorke. The antiulcerative activity was evaluated in indomethacin-induced ulcer model (40 mg/kg body weight [BW], i.p, single dose) against a reference drug, cimetidine (100 mg/kg BW, p.o). ST was assessed at two different doses (200 and 400 mg/kg BW, p.o). Treatments were done twice daily at 8 h interval for 7 days before indomethacin administration. The i.p LD 50 was determined as 774.60 mg/kg BW and oral administration of the extract at 18,000 mg/kg BW dosage did not cause any negative behavioral changes in the animals, and no mortality was recorded after 24 h of the experiment. ST-pre-treated animals showed some improvement against indomethacin-induced ulceration. The extract curtailed indomethacin-induced reduction in gastric volume (36.1%), free acidity (55.3%), total acidity (35.6%) while minimizing the increase in pH by 13.3%. Moreover, the extract showed 17.92% and 14.96% ulcer protective ability at 200 and 400 mg/kg BW, respectively. The phytochemical analysis of ST extract revealed the presence of phytoconstituents such as glycosides, saponins, flavonoids, terpenoids, alkaloids, tannins, anthraquinone, and glycosides. ST apparently has a promising antiulcerative potential, and is safe for use in folk medicine. This valuable medicinal property is probably due to the array of important phytochemicals contained in the plant as observed in this study. However, a further study involving bioassay-guided identification of the main antiulcerative compound in ST is required to establish the use of the plant as a viable antiulcerative agent.

  12. Sensitivity of shovelnose sturgeon (Scaphirhynchus platorynchus) and pallid sturgeon (S. albus) early life stages to 3,30,4,40,5-pentachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure

    Science.gov (United States)

    Buckler, Justin; Candrl, James S.; McKee, Michael J.; Papoulias, Diana M.; Tillitt, Donald E.; Galat, David L.

    2015-01-01

    Concern exists that polychlorinated biphenyls (PCBs) may be contributing to the current decline of shovelnose sturgeon (Scaphirhynchus platorynchus) and the US federally endangered pallid sturgeon (Scaphirhynchus albus). Waterborne exposures with newly fertilized eggs were used to assess developmental and morphological effects of 2 of the most potent aryl hydrocarbon receptor (AhR) agonists, 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on early life stage shovelnose and pallid sturgeon. No dose-related effects of PCB-126 were observed on percent development or hatch in either species at concentrations as high as 1711 ng/g egg. Effects of TCDD on percent development were not assessed in shovelnose sturgeon. However, percent development was not affected by TCDD in pallid sturgeon, and percent hatch was unaffected by TCDD doses as high as 60 ng/g egg to 81 ng/g egg in either species. Morphological pathologies such as yolk sac edema and craniofacial deformities were typical of AhR agonist exposure and were similar in both species. Calculated PCB-126 50% lethal dose (LD50, 95% fiducial limits) values were 196 ng/g egg (188–203 ng/g) for shovelnose and 159 ng/g egg (122–199 ng/g) for pallid sturgeon. Likewise, calculated TCDD LD50 values were 13 ng/g egg (11–15 ng/g) for shovelnose and 12 ng/g egg (10–14 ng/g) for pallid sturgeon. These LD50 values are among the highest recorded in early life stage fish, suggesting that early life stage Scaphirhynchus sturgeon may be comparatively insensitive to AhR agonists.

  13. RBE of Cf-252 neutrons as determined by its lethal, mutagenic, and cytogenetic effects on human cells

    International Nuclear Information System (INIS)

    Ban, Sadayuki

    1989-01-01

    To assess the biological effects of neutrons, a man-made spontaneously fissioning isotope, Cf-252, is useful as an experimental model to obtain basic biological data on mixed radiation of gamma-rays and neutrons. The paper describes the lethal effect of Cf-252 radiation on human skin fibroblasts, its lethal and mutagenic effect on HeLa MR cells, and the micronuclei inducing effect on human peripheral lymphocytes. Dose-survival responses of three fibroblast cell strains exposed to Cf-252 radiation are measured. Individual difference is larger than the experimental fluctuation. D 10 values of each strain are obtained from the linear model and linear-quadratic model. Though the dose rate of X-ray is higher than that of Cf-252 radiations, the mean value of RBE(n+γ) is simply obtained as 1.86+0.31 (RBE:relative biological effectiveness). RBE(n) of Cf-252 neutrons to high-dose-rate X-rays is 2.29. After X-ray irradiation, the survival curve of HeLa MR cells gives an extrapolation number of 3.6. It is 1.3 after Cf-252 irradiation. At 50% survival, RBE(n+γ) and RBE(n) are 2.05 and 2.6, respectively. At 10% survival they are 2.05 and 2.6. The mutation frequencies after X-ray irradiation showed a significant non-linear increase with dose. Those after Cf-252 irradiation increase linearly with dose. (N.K.)

  14. Estimation of dependence between mean of fractionation of photons and neutrons dose and intensity of post-irradiation reaction of mouse large intestine; Ocena zaleznosci pomiedzy sposobem frakcjonowania dawki fotonow i neutronow a nasileniem popromiennego odczynu jelita grubego myszy

    Energy Technology Data Exchange (ETDEWEB)

    Gasinska, A. [Oncology Center, Cracow (Poland)

    1995-12-31

    The aim of the work was verification of mouse large intestine tolerance on fractionated 250 kV X-rays and 2.3 MeV neutrons doses. Two cm of large intestine of mouse CBA/HT strain were irradiated with various fraction doses: from 0.25 to 35 Gy of X-rays and 0.05-12 Gy of neutrons. The measure of injury was handicap of intestine function. Early post-irradiation reaction was measured by loss of body weight (2-3 weeks after irradiation) and mouse mortality (till 2 months after irradiation, LD50/2). The late reaction was measured on the base of maximal body weight in 1 year period after irradiation, deformation of excrements (after 10 months) and death of animals (till 12. month after irradiation, LD50/12). Fractionation of X-ray dose influenced on decrease of intensification of late irradiation effects. After fractionation of neutrons this effect has not been observed. {alpha}/{beta} coefficient for X-rays was 19.9 Gy [15.2; 27.0] for body weight nadir, 13.4 Gy [9.3; 19.5] for early mortality (LD50/2), 6.4 Gy [3.6;11.0] for maximal body weight and 6.9 [4.2; 10.8] for late mortality (LD50/12). Analysis of influence of low doses of photons 90.25-4 Gy) and neutrons (0.05-0.8 Gy) showed trend to reduction {alpha}/{beta} for photons only (LD50/2=5.4 Gy; LD50/12=4.6 Gy). {alpha}/{beta} coefficient for neutrons was defined by LQ model only for maximal body weight and was 19.9 Gy [9.5; 61.0]. In application of graphic method {alpha}/{beta} for neutrons was 230 Gy for early and 48 Gy for late effects. Lower values of {alpha}/{beta} coefficient for late irradiation effects for photon radiation demonstrate the big influence of fractionation of photons dose on large intestine tolerance (decrease intensity in all biological effects). Author did not observe increase of intestine tolerance in fractionation of neutrons dose. Effect of irradiation damages repair in interfraction pauses, measured by percent of regenerated dose (F{sub r}) was much bigger for photons. For X-rays it was 50

  15. Manifestations of radiation syndrome in pigs

    International Nuclear Information System (INIS)

    Kljajic, R.; Masic, Z.; Petrovic, B.; Ciganovic, P.

    1996-01-01

    Clinical and hematological changes in pigs after one-time acute radiation by high-energy-X-rays were described. The of animals was performed by using the linear accelerator of industrial type, with X-rays of 4 MeV, with semi-lethal dose (LD 50/30 = 3.20 Gy) bilaterally (50% of the dose from each side). The radiation syndrome in pigs developed through 4 stages of the disease: the prodromal stadium (1-3 days), the latent stadium (3-7 days), the stadium of expressed clinical symptoms (7-18 days) and the stadium of recovery (after 25 days). The basic characteristic of the disease was a strong haemorrhagic diathesis with expressed blood spots on the skin and bleedings from the nose and the anus as well as a rush decrease of blood dementia (leukocytes and thrombocytes) already 24 hours after radiation. (author)

  16. IAS 39 og konverterbar gæld

    DEFF Research Database (Denmark)

    Fredslund Møller, Peder; Thinggaard, Frank

    , at der er en betydelig beholdning af konverterbare realkreditlån, som der skal aflægges regnskab for. Denne artikel har til formål at belyse de alternativer, der findes i IAS39 til regnskabsmæssig behandling af konverterbar gæld. I juli 2008 kom der en tilføjelse til IAS 39, "Eligible Hedged Items". Den......: 1. dagsværdimetode, hvor "hele det konverterbare lån", dvs. både den "rene gæld" og den indbyggede indfrielsesoption, der iflg. IAS 39 udgør de to komponenter i et konverterbart lån, føres til dagsværdi, 2. udskillelsesmetode, hvor der anvendes amortiseret kostpris for den "rene gæld" og dagsværdi...

  17. Evaluation of the bioactivities of some Myanmar medicinal plants using brine shrimp (Artemia salina) toxicity test

    International Nuclear Information System (INIS)

    Sabai; Khin Khin Win Aung; Nwe Ni Thin; Kyi Shwe; Tin Myint Htwe

    2001-01-01

    For a variety of toxic substances, brine shrimp larvae (Artemia salina) are usually used as a simple bioassay method and it is also applied for natural product research. The brine shrimp larvae (nauplii) are obtained by natural hatching method from Artemia cysts. By using the larvae, the results from these experiments lead to the lethal dose, LD 50 values of extracts of selected medicinal plants. Activities of a broad range of plant extracts are manifested as toxicity to the brine shrimp. Screening results with six plant extracts are compared with pure caffeine. This method is rapid, reliable, inexpensive and convenient. (author)

  18. Effects of gamma irradiation on different phases of coffee borer Hypothenemus hampei (Ferrari, 1867)

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Silva, A.L. da.

    1974-10-01

    Two experiments carried out in order to determine immediate lethal doses (LD sub(I)) for gamma irradiation of larvae, pupae and adults hypothenemus hampei (Ferrari, 1867) are presented. One experiment aimed only the determination of LD sub(I) for the adults of the coffee borer-outside the coffee-berries. The other to obtain the equivalent data for insects inside the coffee-berry, for all phases of the development cycle of the insect. It was found that LD sub(I) for larvae was around 350 Krad and for pupae around 400 Krad. For the adults, the LD sub(I) for insects outside the coffee-berry was 475 Krad and 525 for insects inside the coffee-berry. It was found that smaller doses caused a pronunced decrease in the insect lifetime, lifetime decrease proportionally as the irradiation dose increase. According to the results obtained, is postulated that this species of coffee-borer may be considered resistant to gamma radiation [pt

  19. Mosquitocidal Activity and Mode of Action of the Isoxazoline Fluralaner

    OpenAIRE

    Jiang, Shiyao; Tsikolia, Maia; Bernier, Ulrich R.; Bloomquist, Jeffrey R.

    2017-01-01

    Mosquitoes, such as Aedes aegypti and Anopheles gambiae, are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC50 (lethal concentration for 50% mortality) values of 1.8 ppb and 0.4 ppb, respectively. Following topical application to adult Ae. aegypti, fluralaner toxicity reached a plateau in about 3 days, with 1- and 3-day LD50 (lethal do...

  20. Analysis of dose-incidence relationships for marrow failure in different species, in terms of radiosensitivity of tissue-rescuing units

    International Nuclear Information System (INIS)

    Hendry, J.H.; Roberts, S.A.

    1990-01-01

    The analysis of 68 published sets of dose-incidence data for marrow failure in different species, using a double-log mortality function, indicates: (a) There is more heterogeneity, i.e. greater sums-of-squares per degree of freedom, within the data sets for mouse than for larger species (monkey, dog, sheep, goat, pig). (b) For mice the curves for acute doses are characterized by a D0 of about 100 cGy for tissue-rescuing units (or target cells), which are depleted at most to about 3 x 10(-4) at LD50. (c) Larger species are much less tolerant to target-cell depletion, the corresponding level being consistently in the range of 10(-2)-10(-3) at LD50. Also, the D0 is often lower (approximately 55 cGy), which is compatible in the dog with such a value for hemopoietic progenitor cells. (d) With larger species there is an unexpected reduction in heterogeneity when the dose rate is lower, which gives a D0 lower than expected and a higher extrapolate. It is concluded that the position and slope of the dose-incidence curves are compatible with interpretations based primarily on target-cell number and survival characteristics, modified by additional heterogeneity factors

  1. The Social Acceptance of Secondary School Students with Learning Disabilities (LD

    Directory of Open Access Journals (Sweden)

    Teja Lorger

    2015-06-01

    Full Text Available This paper aims to shed light on the level of social acceptance among students with learning disabilities (LD in various secondary school vocational programs in comparison with their peers without disabilities. Our findings are based on an empirical study that comprised 417 students, of whom 85 were students with LD. Based on sociometric analyses of all participating classes, we determined that students with LD were less integrated into the classroom in comparison to their peers without LD. The results of the sociometric analysis show statistically significant differences in the sociometric position between students with LD and students without LD. While students with LD were most frequently perceived as rejected, students without LD were seen as popular or average. In addition, students with LD see themselves as less socially self-efficient compared to their peers. The results of our study mostly refer to boys, because the sample comprised 359 boys and 58 girls. We believe that pro-inclusion teachers with appropriately developed strategies for strengthening students’ social skills, as well as positive attitudes and sufficient knowledge about the special needs of students can have a significant impact on the social acceptance of students with special needs in the classroom community.

  2. Rifaximin diminishes neutropenia following potentially lethal whole-body radiation.

    Science.gov (United States)

    Jahraus, Christopher D; Schemera, Bettina; Rynders, Patricia; Ramos, Melissa; Powell, Charles; Faircloth, John; Brawner, William R

    2010-07-01

    Terrorist attacks involving radiological or nuclear weapons are a substantial geopolitical concern, given that large populations could be exposed to potentially lethal doses of radiation. Because of this, evaluating potential countermeasures against radiation-induced mortality is critical. Gut microflora are the most common source of systemic infection following exposure to lethal doses of whole-body radiation, suggesting that prophylactic antibiotic therapy may reduce mortality after radiation exposure. The chemical stability, easy administration and favorable tolerability profile of the non-systemic antibiotic, rifaximin, make it an ideal potential candidate for use as a countermeasure. This study evaluated the use of rifaximin as a countermeasure against low-to-intermediate-dose whole-body radiation in rodents. Female Wistar rats (8 weeks old) were irradiated with 550 cGy to the whole body and were evaluated for 30 d. Animals received methylcellulose, neomycin (179 mg/kg/d) or variably dosed rifaximin (150-2000 mg/kg/d) one hour after irradiation and daily throughout the study period. Clinical assessments (e.g. body weight) were made daily. On postirradiation day 30, blood samples were collected and a complete blood cell count was performed. Animals receiving high doses of rifaximin (i.e. 1000 or 2000 mg/kg/d) had a greater increase in weight from the day of irradiation to postirradiation day 30 compared with animals that received placebo or neomycin. For animals with an increase in average body weight from irradiation day within 80-110% of the group average, methylcellulose rendered an absolute neutrophil count (ANC) of 211, neomycin rendered an ANC of 334, rifaximin 300 mg/kg/d rendered an ANC of 582 and rifaximin 1000 mg/kg/d rendered an ANC of 854 (P = 0.05 for group comparison). Exposure to rifaximin after near-lethal whole-body radiation resulted in diminished levels of neutropenia.

  3. Students classified as LD and the college foreign language requirement: a quantitative analysis.

    Science.gov (United States)

    Sparks, R L; Philips, L; Ganschow, L; Javorsky, J

    1999-01-01

    This study was conducted to determine whether students classified as learning disabled (LD) who were permitted to substitute courses for the college foreign language (FL) requirement at one university would display significant cognitive and academic achievement differences when grouped by level of discrepancy between IQ and achievement, by discrepancy between achievement according to different measures, and by level of performance on phonological-orthographic processing measures, on the Modern Language Aptitude Test (MLAT), and in FL courses. Results showed that there were no differences among students with different levels of discrepancy (i.e., 1.50 SD) on MLAT and American College Testing (ACT) scores, graduating grade point average (GPA) or college FL GPA. Results also showed that among students who scored below versus at or above the 25th percentile on phonological-orthographic processing measures, there were no differences on measures of IQ, ACT, MLAT, and GPA, as well as most measures of academic achievement. Implications for the use of the LD label to grant FL course substitutions or waivers, use of the MLAT in the diagnostic and course substitution/waiver process, and the validity and reliability of traditional criteria for the classification as LD are discussed.

  4. Evaluating the lethal and pre-lethal effects of a range of fungi against adult Anopheles stephensi mosquitoes

    Directory of Open Access Journals (Sweden)

    Blanford Simon

    2012-11-01

    Full Text Available Abstract Background Insecticide resistance is seriously undermining efforts to eliminate malaria. In response, research on alternatives to the use of chemical insecticides against adult mosquito vectors has been increasing. Fungal entomopathogens formulated as biopesticides have received much attention and have shown considerable potential. This research has necessarily focused on relatively few fungal isolates in order to ‘prove concept’. Further, most attention has been paid to examining fungal virulence (lethality and not the other properties of fungal infection that might also contribute to reducing transmission potential. Here, a range of fungal isolates were screened to examine variation in virulence and how this relates to additional pre-lethal reductions in feeding propensity. Methods The Asian malaria vector, Anopheles stephensi was exposed to 17 different isolates of entomopathogenic fungi belonging to species of Beauveria bassiana, Metarhizium anisopliae, Metarhizium acridum and Isaria farinosus. Each isolate was applied to a test substrate at a standard dose rate of 1×109 spores ml-1 and the mosquitoes exposed for six hours. Subsequently the insects were removed to mesh cages where survival was monitored over the next 14 days. During this incubation period the mosquitoes’ propensity to feed was assayed for each isolate by offering a feeding stimulant at the side of the cage and recording the number probing. Results and conclusions Fungal isolates showed a range of virulence to A. stephensi with some causing >80% mortality within 7 days, while others caused little increase in mortality relative to controls over the study period. Similarly, some isolates had a large impact on feeding propensity, causing >50% pre-lethal reductions in feeding rate, whereas other isolates had very little impact. There was clear correlation between fungal virulence and feeding reduction with virulence explaining nearly 70% of the variation in

  5. Survival patterns and hemopathological responses of dogs under continuous gamma irradiation

    International Nuclear Information System (INIS)

    Seed, T.M.; Fritz, T.E.; Tolle, D.V.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.; Kaspar, L.V.; Cullen, S.M.; Carnes, B.A.

    1983-01-01

    Survival curves were constructed and analyzed relative to contributing hematopathological responses for groups of beagles exposed continuously for duration of life to low daily doses of whole body 60 Co gamma irradiation (27.3 rads/day to 4 rads/day). The survival curves versus time were progressively displaced toward longer survival as rates of exposure were reduced from the relatively high dose rate of 27.3 rads/day to the low dose rate of 4.0 rads/day. Average survival times increased from 57 days at 27.3 rads/day to 1830 days at 4.0 rads/day, representing fractional increased life-spans from 1.5% to 50.8%, respectively. Survival curves versus total dose were markedly displaced along the cumulative radiation dose axis at the extreme dose rates (i.e., 27.3 and 4.0 rads/day), but not at the intermediate dose rates (i.e., 13.4 and 7.9 rads/day) in which the upper linear portions of the survival curves are superimposed. From these dose-dependent survival curves, LD 50 values for whole body gamma irradiation, delivered chronically at 27.3, 13.4, 7.9, and 4.0 rads per day were estimated to be 1442, 2124, 2039, and 7161 rads, respectively. Both time- and dose-dependent survival curves for the intermediate dose rates, in contrast to the extreme dose rates, exhibited pronounced transitions in the lethality rate below the 50% survival level. These lethality rate transitions occurred at approx. 2500 rads of accumulated dose and were attributed to a shift in the spectrum of developing hematopathologies: namely, from a predominance of the acutely ablative radiation-induced lymphohematopoietic syndromes (i.e., septicemias and aplastic anemias) to a predominance of the late arising hematopoietic neoplasias (myelogenous leukemia and related myeloproliferative disorders)

  6. Platelet reactivity in response to loading dose of atorvastatin or rosuvastatin in patients with stable coronary disease before percutaneous coronary intervention: The STATIPLAT randomized study.

    Science.gov (United States)

    Godino, Cosmo; Pavon, Anna Giulia; Mangieri, Antonio; Salerno, Anna; Cera, Michela; Monello, Alberto; Chieffo, Alaide; Magni, Valeria; Cappelletti, Alberto; Margonato, Alberto; Colombo, Antonio

    2017-08-01

    The acute effects of statin loading dose (LD) on platelet reactivity in patients with chronic stable angina (CSA) are not completely clear. We hypothesized that LDs of atorvastatin and rosuvastatin have different pharmacodynamic acute effects on platelet aggregability in CSA patients with baseline normal platelet reactivity while on dual antiplatelet therapy (DAPT). From September 2011 to February 2014, all consecutive CSA patients on chronic DAPT (aspirin and clopidogrel) were evaluated before elective percutaneous coronary intervention (PCI). An initial assessment of platelet reactivity in response to thrombin receptor agonist, ADP, and ASP (respectively, indicative of the response to clopidogrel and aspirin) was performed with impedance aggregometry. Patients with high platelet reactivity to ADP test (area under the curve >47) were excluded. The remaining patients were randomized into 3 treatment groups: Group A, atorvastatin LD 80 mg; Group B, rosuvastatin LD 40 mg; and Group C, no statin LD (control group). A second assessment of platelet reactivity was performed ≥12 hours after statin LD. 682 patients were screened and 145 were randomized into the 3 groups. At baseline and after statin LD, no significant difference was found in platelet reactivity in response to 3 different agonists between the 3 groups. Subgroup analysis showed that platelet reactivity to ADP test was significantly lower in patients chronically treated with low-dose statins (n = 94) compared with statin-naïve patients (n = 51; 15.32 ± 1.50 vs 18.59 ± 1.30; P = 0.007). Loading dose of atorvastatin (80 mg) or rosuvastatin (40 mg) did not induce significant variation in platelet reactivity in CSA patients with baseline reduced platelet reactivity as in chronic DAPT. Our data confirm that chronic concomitant treatment with low-dose statins and clopidogrel resulted in significantly lower platelet reactivity compared with clopidogrel alone. © 2017 Wiley Periodicals, Inc.

  7. Chimeric anti-staphylococcal enterotoxin B antibodies and lovastatin act synergistically to provide in vivo protection against lethal doses of SEB.

    Directory of Open Access Journals (Sweden)

    Mulualem E Tilahun

    Full Text Available Staphylococcal enterotoxin B (SEB is one of a family of toxins secreted by Staphylococcus aureus that act as superantigens, activating a large fraction of the T-cell population and inducing production of high levels of inflammatory cytokines that can cause toxic shock syndrome (TSS and death. Extracellular engagement of the TCR of T-cells and class II MHC of antigen presenting cells by SEB triggers the activation of many intracellular signaling processes. We engineered chimeric antibodies to block the extracellular engagement of cellular receptors by SEB and used a statin to inhibit intracellular signaling. Chimeric human-mouse antibodies directed against different neutralizing epitopes of SEB synergistically inhibited its activation of human T-cells in vitro. In the in vivo model of lethal toxic shock syndrome (TSS in HLA-DR3 transgenic mice, two of these antibodies conferred significant partial protection when administered individually, but offered complete protection in a synergistic manner when given together. Similarly, in vivo, lovastatin alone conferred only partial protection from TSS similar to single anti-SEB antibodies. However, used in combination with one chimeric neutralizing anti-SEB antibody, lovastatin provided complete protection against lethal TSS in HLA-DR3 transgenic mice. These experiments demonstrate that in vivo protection against lethal doses of SEB can be achieved by a statin of proven clinical safety and chimeric human-mouse antibodies, agents now widely used and known to be of low immunogenicity in human hosts.

  8. Comparative toxicity and efficacy of engineered anthrax lethal toxin variants with broad anti-tumor activities

    International Nuclear Information System (INIS)

    Peters, Diane E.; Hoover, Benjamin; Cloud, Loretta Grey; Liu, Shihui; Molinolo, Alfredo A.; Leppla, Stephen H.; Bugge, Thomas H.

    2014-01-01

    We have previously designed and characterized versions of anthrax lethal toxin that are selectively cytotoxic in the tumor microenvironment and which display broad and potent anti-tumor activities in vivo. Here, we have performed the first direct comparison of the safety and efficacy of three engineered anthrax lethal toxin variants requiring activation by either matrix-metalloproteinases (MMPs), urokinase plasminogen activator (uPA) or co-localized MMP/uPA activities. C57BL/6J mice were challenged with six doses of engineered toxins via intraperitoneal (I.P.) or intravenous (I.V.) dose routes to determine the maximum tolerated dose for six administrations (MTD6) and dose-limiting toxicities. Efficacy was evaluated using the B16-BL6 syngraft model of melanoma; mice bearing established tumors were treated with six I.P. doses of toxin and tumor measurements and immunohistochemistry, paired with terminal blood work, were used to elaborate upon the anti-tumor mechanism and relative efficacy of each variant. We found that MMP-, uPA- and dual MMP/uPA-activated anthrax lethal toxins exhibited the same dose-limiting toxicity; dose-dependent GI toxicity. In terms of efficacy, all three toxins significantly reduced primary B16-BL6 tumor burden, ranging from 32% to 87% reduction, and they also delayed disease progression as evidenced by dose-dependent normalization of blood work values. While target organ toxicity and effective doses were similar amongst the variants, the dual MMP/uPA-activated anthrax lethal toxin exhibited the highest I.P. MTD6 and was 1.5–3-fold better tolerated than the single MMP- and uPA-activated toxins. Overall, we demonstrate that this dual MMP/uPA-activated anthrax lethal toxin can be administered safely and is highly effective in a preclinical model of melanoma. This modified bacterial cytotoxin is thus a promising candidate for further clinical development and evaluation for use in treating human cancers. - Highlights: • Toxicity and anti

  9. Comparative toxicity and efficacy of engineered anthrax lethal toxin variants with broad anti-tumor activities

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Diane E. [Proteases and Tissue Remodeling Section, Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Program of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA (United States); Hoover, Benjamin [Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD (United States); Cloud, Loretta Grey [Proteases and Tissue Remodeling Section, Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Liu, Shihui [Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD (United States); Molinolo, Alfredo A. [Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Leppla, Stephen H. [Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD (United States); Bugge, Thomas H., E-mail: thomas.bugge@nih.go [Proteases and Tissue Remodeling Section, Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States)

    2014-09-01

    We have previously designed and characterized versions of anthrax lethal toxin that are selectively cytotoxic in the tumor microenvironment and which display broad and potent anti-tumor activities in vivo. Here, we have performed the first direct comparison of the safety and efficacy of three engineered anthrax lethal toxin variants requiring activation by either matrix-metalloproteinases (MMPs), urokinase plasminogen activator (uPA) or co-localized MMP/uPA activities. C57BL/6J mice were challenged with six doses of engineered toxins via intraperitoneal (I.P.) or intravenous (I.V.) dose routes to determine the maximum tolerated dose for six administrations (MTD6) and dose-limiting toxicities. Efficacy was evaluated using the B16-BL6 syngraft model of melanoma; mice bearing established tumors were treated with six I.P. doses of toxin and tumor measurements and immunohistochemistry, paired with terminal blood work, were used to elaborate upon the anti-tumor mechanism and relative efficacy of each variant. We found that MMP-, uPA- and dual MMP/uPA-activated anthrax lethal toxins exhibited the same dose-limiting toxicity; dose-dependent GI toxicity. In terms of efficacy, all three toxins significantly reduced primary B16-BL6 tumor burden, ranging from 32% to 87% reduction, and they also delayed disease progression as evidenced by dose-dependent normalization of blood work values. While target organ toxicity and effective doses were similar amongst the variants, the dual MMP/uPA-activated anthrax lethal toxin exhibited the highest I.P. MTD6 and was 1.5–3-fold better tolerated than the single MMP- and uPA-activated toxins. Overall, we demonstrate that this dual MMP/uPA-activated anthrax lethal toxin can be administered safely and is highly effective in a preclinical model of melanoma. This modified bacterial cytotoxin is thus a promising candidate for further clinical development and evaluation for use in treating human cancers. - Highlights: • Toxicity and anti

  10. Effects of red and blue LD lights on the growth of lettuce

    International Nuclear Information System (INIS)

    Mori, Y.; Takatsuji, M.; Yasuoka, T.

    2003-01-01

    In this study, Lactuca sativa L. cv. “Red Fire” was cultivated under visible laser diodes (LD) light alone, using red and blue LD for digital versatile discs (DVD). Relative growth rate, photosynthetic rate and vitamin C content were measured, and compared with those obtained using light emitting diodes (LED). When the lettuce was cultivated under LD light, the relative growth rate and net photosynthetic rate were decreased compared to those under LED light. The rates were decreased by 10% and 20% or more under red LD light and under a combination of red and blue LD lights, respectively. However, the vitamin C content was higher when grown under LD light than LED light. Considering the high output and high electrical-to-optical power conversion efficiency of LD, LD are potential light sources for plant cultivation when their prices decrease

  11. LD in AD 2000.

    Science.gov (United States)

    Smith, Bert Kruger

    The author discusses potential problems and benefits for learning disabled (LD) students in the year 2000. Considered are developments in three areas: human engineering (such as the role of amniocentesis in prevention of disabilities), education (including new audiovisual technology and a restructuring of secondary education), and human…

  12. Dose responses of in vivo- and in vitro-produced strains of gypsy moth (Lepidoptera: Lymantriidae) nucleopolyhedrovirus (LdMNPV) applied with and without the virus enhancer Blankophor BBH

    Science.gov (United States)

    John D. Podgwaite; James M. Slavicek; Kevin W. Thorpe; Ralph E. Webb; Roger W. Fuester; Vincent D' Amico; Randel A. Peiffer; Michael A. Valenti

    2013-01-01

    The gypsy moth, Lymantria dispar L., nucleopolyhedrovirus (LdMNPV) product Gypchek is a microbial pesticide produced by the USDA Forest Service. Gypchek is a mixture of LdMNPV genotypes produced in vivo. Commercial interests prefer to develop a stable, high-potency genotype that can be produced at low cost, preferably in vitro. We sprayed 2 LdMNPV...

  13. Lethal Area 50 in Patients with Burn Injuries in North West, Iran

    Directory of Open Access Journals (Sweden)

    Ahmad Mirza Aghazadeh

    2018-03-01

    Full Text Available Introduction: In view of their considerably high rates of mortality and morbidity, burns are still viewed as one of the most important health-threatening environmental hazards imposing a significant burden on the health care system in low and middle-income countries. This study seeks to determine the lethal area fifty percent (LA50 in all burn patients admitted over a period of five years and the factors influencing mortality in burn injuries. Methods: This study was a cross-sectional carried out from 2010 to 2014 in Sina Hospital of Tabriz, 1226 participant including 319 women, 346 men, 272 girls, and 289 boys were selected through stratified sampling. The demographic and clinical data of patients ( their age, gender, burn type, TBSA, the season and consequences of burning were all extracted and then analyzed, using descriptive statistics (measures of central tendency and variability and inferential statistics(chi-square and linear regressionat a significance level of 0.05. The LA50 was calculated through determining the relationship between the total body surface area and mortality rate (The extent of the body burns measured and recorded based on Lando Chart in hospitals. Results: The highest (47.6% and the lowest (3.8% rates of burns were observed among those aged below 16 and above 65, respectively. The majority of the participants were residents of cities (55.4%, married (34.6%, illiterate (56.6%, and housewives (14.8%. Most burns were caused by accidents (98.4% at home (90.6%. Most patients had suffered first- and second-degree burns (68.4%, with no inhalation damages (99.5%. Hot liquids were the main culprit in most of the burns (58.7% and the upper extremities were the most frequently affected areas (34.8%. There was .99 rise in mortality for every percent increase in TBSA, and there seemed to be a significant relationship between the age level and the eventual outcome- the higher the age, the more likely for the incident to end in death

  14. Triazole incorporated thiazoles as a new class of anticonvulsants: design, synthesis and in vivo screening.

    Science.gov (United States)

    Siddiqui, Nadeem; Ahsan, Waquar

    2010-04-01

    Various 3-[4-(substituted phenyl)-1,3-thiazol-2-ylamino]-4-(substituted phenyl)-4,5-dihydro-1H-1,2,4-triazole-5-thiones (7a-t) were designed keeping in view the structural requirements suggested in the pharmacophore model for anticonvulsant activity. Thiazole and triazole moieties being anticonvulsants were clubbed together to get the titled compounds and their in vivo anticonvulsant screening were performed by two most adopted seizure models, maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ). Two compounds 7d and 7f showed significant anticonvulsant activity in both the screens with ED(50) values 23.9 mg/kg and 13.4 mg/kg respectively in MES screen and 178.6 mg/kg and 81.6 mg/kg respectively in scPTZ test. They displayed a wide margin of safety with Protective index (PI), median hypnotic dose (HD(50)) and median lethal dose (LD(50)) much higher than the standard drugs. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  15. Progeny of Spalangia endius Walker, 1839 (Hymenoptera: Pteromalidae) in Musca domestica L., 1758 (Diptera: Muscidae) non-viable pupae irradiated by gamma Cobalt-60 and cold stored

    International Nuclear Information System (INIS)

    Itepan, Sara Eloiza Zen.

    1992-06-01

    This study was designed to test acceptability of cold stored irradiated and non-irradiated pupae of Musca domestica L., 1758 (Diptera: Muscidae) by the parasitoid Spalangia endius Walker, 1839 (Hymenoptera: Pteromalidae). The work was carried out in the laboratory of the Entomology Section of the Center of Nuclear Energy in Agriculture (CENA/USP) and in the laboratory of Biological Control of House Flies Eduardo Hiroshi Mizumoto of Entomology Department of the College of Agriculture Luiz de Queiroz (ESALQ/USP), Piracicaba, Sao Paulo, Brazil. The gamma radiation source used was a Cobalt-60 irradiator, Gamma bean-650, with an initial activity of 1,6265 x 10 4 Bq (6,746 Ci). The radiation LD 50 e LD 100 , using a dose ratio of 1457 Gy/h, for 12, 24, 36, 48, 60 and 72 hours old pupae and resulted in 15.35; 15.69; 11.30; 49.4; 142.78 and 175 Gy for LD 50 and 20, 22.5; 32.5; 175; 225 and 300 Gy for LD'1 00 respectively. Following exposure, the pupae were kept in climate chamber at 27 ± 3 0 C and 75 ± % of relative humidity, until all adults had emerged. In succession, 24, 48 and 72 hour-old pupae were exposed to gamma irradiation with a dose of 1440 Gy/hour, in their respective lethal doses. Following the exposure the pupae were stored at cool temperature (10 ± 2 0 C) for different periods of time (5, 15, 20 and 30 days). The same treatment was given for non-irradiated pupae. After the storage period the pupae were expose for 24 h to S. endius in a ratio of 1:10 parasitoid-host. It was not observed any statistical difference (Turkey 5%) in progeny of males and females emerged from irradiated and non-irradiated pupae. There was a preference of the parasitoid to pupae of 48 hours old followed by 24 and 72 hours old for storage period more than 5 days and shorter than 20 days. (author). 50 refs., 6 figs., 17 tabs

  16. Effects of gamma radiation on in vitro plantlets of Alpinia purpurata

    International Nuclear Information System (INIS)

    Fereol, L.; Louis, S.; Luce, L.

    1996-01-01

    Two cultivars of Alpinia purpurata were propagated by in vitro culture to provide numerous convenient plantlets that were exposed to 0, 15, 30, or 45 Gy of gamma rays to study their radiosensitivity. The plants of the C1 and C2 clonal generations showed decreases in plant survival rate, fresh weight gain and micropropagation rate with increasing doses of gamma radiation. On the basis of survival, LD 50 was approximately 30 Gy. The 45 Gy dose drastically affects the different responses studied. It proved lethal or induced dwarf plants. Some plantlets, produced in vitro from treated plants, showed morphological abnormalities of leaves or of whole plants. This technique has potential for increasing the genetic variation in Alpinia purpurata. (author)

  17. Distribution of Pyrethroid Resistant Populations of Triatoma infestans in the Southern Cone of South America.

    Directory of Open Access Journals (Sweden)

    Marinely Bustamante Gomez

    2016-03-01

    Full Text Available A number of studies published during the last 15 years showed the occurrence of insecticide resistance in Triatoma infestans populations. The different toxicological profiles and mechanisms of resistance to insecticides is due to a genetic base and environmental factors, being the insecticide selective pressure the best studied among the last factors. The studies on insecticide resistance on T. infestans did not consider the effect of environmental factors that may influence the distribution of resistance to pyrethroid insecticides. To fill this knowledge gap, the present study aims at studying the association between the spatial distribution of pyrethroid resistant populations of T. infestans and environmental variables.A total of 24 articles reporting on studies that evaluated the susceptibility to pyrethroids of 222 field-collected T. infestans populations were compiled. The relationship between resistance occurrence (according to different criteria with environmental variables was studied using a generalized linear model. The lethal dose that kills 50% of the evaluated population (LD50 showed a strong linear relationship with the corresponding resistance ratio (RR50. The statistical descriptive analysis of showed that the frequency distribution of the Log (LD50 is bimodal, suggesting the existence of two statistical groups. A significant model including 5 environmental variables shows the geographic distribution of high and low LD50 groups with a particular concentration of the highest LD50 populations over the region identified as the putative center of dispersion of T. infestans.The occurrence of these two groups concentrated over a particular region that coincides with the area where populations of the intermediate cytogenetic group were found might reflect the spatial heterogeneity of the genetic variability of T. infestans, that seems to be the cause of the insecticide resistance in the area, even on sylvatic populations of T. infestans

  18. Preliminary assays for lemongrass essential oil ecotoxicological test in D. similis and C. silvestrii submitted to gamma radiation

    International Nuclear Information System (INIS)

    Gimiliani, Giovana T.; Rogero, Sizue O.; Rogero, Jose R.; Cruz, Aurea S.

    2011-01-01

    Pharmaceutical products are of great interest in ecotoxicological studies due to being found some of these products in the superficial waters and sediments, water and sewage treatment effluents. It was verified an increase of insect repellent chemical products in the aquatic environment because of the increase of diseases transmitted by mosquitoes like dengue. As these compounds show toxicity, the use of essential oils natural products with repellent properties is increasing and the literature about the impact in the aquatic environment is scarce. The hydric frame would suffer natural radiation and radiations from energy generation nuclear plants impacts fall out of tests and nuclear accidents. There is no universal definition of environmental protection and there are few studies on radiation effects in the aquatic environment. In this study was determined the lemon grass essential oil toxicity level as well as the lethal dose of ionizing radiation, LD 50 , in aquatic organisms. Cytotoxicity test was performed by in vitro neutral red uptake method in NCTC clone L929 cell line. In the LD 50 test aquatic organisms were submitted to gamma radiation. The essential oil of lemongrass Cymbopogon flexuosus showed cytotoxicity index IC 50 about 50μg.mL -1 . The LD 50 for Daphnia similis was 242 Gy and Ceriodaphnia silvestrii about 525 Gy. Studies will be continued with acute and chronic ecotoxicological tests of lemongrass essential oil in natural organisms and in organisms submitted to gamma radiation, utilizing the results obtained in this work. (author)

  19. The Meaning-making of Dag Hammarskjöld

    Directory of Open Access Journals (Sweden)

    Kristian Stålne

    2011-10-01

    Full Text Available Dag Hammarskjöld, United Nations’ second Secretary-General 1954-1961, is getting recent attention for two reasons: he is going to front the new Swedish 1000-kronor note, the highest value; and this September it was 50 years since he was killed in an airplane crash in UN service in Congo. With that event, the most successful career in an international service that a Swede has ever had was terminated prematurely, a service that would set an unmistakable imprint on the UN organization as well as on the world stage of politics. But what made Dag Hammarskjöld such an exceptional leader and how did he view the world and his role in it? He was not only exceptional as a leader and world-centric visionary; he was also a mystic and an aesthetician with a highly analytic mind. What is unique is the fact that large parts of his thinking and personal struggling are available to the world through a dense material of his speeches and personal writings. This has made it possible to analyse the stages of development represented in them. Using ego development theory, described by Jane Loevinger as well as Robert Kegan, I offer the analysis that his writings, including during his most severe personal crisis, indicate he passed through a transition between the individualist and autonomous stages.

  20. Acute, reproductive toxicity and two-generation teratology studies of a standardized quassinoid-rich extract of Eurycoma longifolia Jack in Sprague-Dawley rats.

    Science.gov (United States)

    Low, Bin-Seng; Das, Prashanta Kumar; Chan, Kit-Lam

    2014-07-01

    The roots of Eurycoma longifolia Jack are popularly sought as herbal medicinal supplements to improve libido and general health amongst the local ethnic population. The major quassinoids of E. longifolia improved spermatogenesis and fertility but toxicity studies have not been well documented. The reproductive toxicity, two generation of foetus teratology and the up-and-down acute toxicity were investigated in Sprague-Dawley rats orally treated with quassinoid-rich E. longifolia extract (TAF273). The results showed that the median lethal dose (LD50 ) of TAF273 for female and male rats was 1293 and >2000 mg/kg, respectively. Fertility index and litter size of the TAF273 treated were significantly increased when compared with those of the non-treated animals. The TAF273-treated dams decreased in percentage of pre-implantation loss, post-implantation loss and late resorption. No toxic symptoms were observed on the TAF273-treated pregnant female rats and their foetuses were normal. The no-observed adverse effect level (NOAEL) obtained from reproductive toxicity and teratology studies of TAF273 in rats was 100 mg/kg body weight/day, being more than 10-fold lower than the LD50 value. Thus, any human dose derived from converting the rat doses of 100 mg/kg and below may be considered as safe for further clinical studies. Copyright © 2013 John Wiley & Sons, Ltd.

  1. Comparison of the cytokine immune response to pathogenic Yersinia enterocolitica bioserotype 1B/O:8 and 2/O:9 in susceptible BALB/C and resistant C57BL/6 mice.

    Science.gov (United States)

    Wang, Xin; Gu, Wenpeng; Qiu, Haiyan; Xia, Shengli; Zheng, Han; Xiao, Yuchun; Liang, Junrong; Jing, Huaiqi

    2013-10-01

    We investigated the lethality of pathogenic Yersinia enterocolitica bioserotypes 1B/O:8 and 2/O:9 in susceptible BALB/C and resistant C57BL/6 mice; the cytokine alterations and histopathological changes were observed comparing the two strains in BALB/C mice. The data showed the 50% lethal dose (LD50) for the pathogenic Y. enterocolitica bioserotype 1B/O:8 was 10³ cfu in both BALB/C and C57BL/6 mice; while the LD50 for the 2/O:9 was 10⁸ cfu in BALB/C mice and 10⁹ cfu in C57BL/6 mice, a large difference. After infection with the two strains in BALB/C mice, GM-CSF (granulocyte-macrophage colony stimulating factor), IFN-γ (interferon-γ), IL-1β (interleukin-1β), IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, and TNF-α (tumor necrosis factor-α) appeared as a cytokine storm in a short period, reached peak values, and then quickly decreased. This appeared important for the immune response and cytokine immunopathogenesis in pathogenic Y. enterocolitica infections. In the initial infection stage, GM-CSF, IL-6, and TNF-α of 2/O:9 were higher than 1B/O:8; and subsequently the status was reversed. However, levels of IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-10, IL-12 following infection with 1B/O:8 were always higher than with 2/O:9. The histopathological changes in the liver and spleen in BALB/C mice infected with the two strains were similar at different times and doses. These observations show the different immunological effects and changes for pathogenic Y. enterocolitica 1B/O:8 and 2/O:9 infections using the mouse model. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Free radical scavenging and the expression of potentially lethal damage in X-irradiated repair-deficient Escherichia coli

    International Nuclear Information System (INIS)

    Billen, D.

    1987-01-01

    When cells are exposed to ionizing radiation, they suffer lethal damage (LD), potentially lethal damage (PLD), and sublethal damage (SLD). All three forms of damage may be caused by direct or indirect radiation action or by the interaction of indirect radiation products with direct DNA damage. In this report I examine the expression of LD and PLD caused by the indirect action of X rays in isogenic, repair-deficient Escherichia coli. The radiosensitivity of a recA mutant, deficient both in pre- and post replication recombination repair and SOS induction (inducible error-prone repair), was compared to that of a recB mutant which is recombination deficient but SOS proficient and to a previously studied DNA polymerase 1-deficient mutant (polA) which lacks the excision repair pathway. Indirect damage by water radicals (primarily OH radicals) was circumvented by the presence of 2 M glycerol during irradiation. Indirect X-ray damage by water radicals accounts for at least 85% of the PLD found in exposed repair-deficient cells. The DNA polymerase 1-deficient mutant is most sensitive to indirect damage with the order of sensitivity polA1 greater than recB greater than or equal to recA greater than wild type. For the direct effects of X rays the order of sensitivity is recA greater than recB greater than polA1 greater than wild type. The significance of the various repair pathways in mitigating PLD by direct and indirect damage is discussed

  3. Effects of acute and repeated oral exposure to the organophosphate insecticide chlorpyrifos on open-field activity in chicks.

    Science.gov (United States)

    Al-Badrany, Y M A; Mohammad, F K

    2007-11-01

    The effects of the organophosphate insecticide chlorpyrifos on 5min open-field activity were examined in a 7-15 days old chick model. Chlorpyrifos was acutely administered taking into account cholinesterase inhibition and determination of the acute (24h) median lethal dose (LD50). The oral LD50 value of chlorpyrifos in chicks was 18.14mg/kg, with cholinergic toxicosis observed on intoxicated chicks. Chlorpyrifos at the dose rates of 5,10 and 20mg/kg orally produced within 2h signs of cholinergic toxicosis in the chicks and significantly inhibited plasma (40-70%), whole brain (43-69%) and liver (31-46%) cholinesterase activities in a dose-dependent manner. Chlorpyrifos at 2 and 4mg/kg, orally did not produce overt signs of cholinergic toxicosis, but decreased (30, 60 and 90min after dosing) the general locomotor activity of the chicks as seen by a significant increase in the latency to move from the central square of the open-field arena, decreases in the numbers of lines crossed and vocalization score. Repeated daily chlorpyrifos treatments (2 and 4mg/kg, orally) for seven consecutive days also caused hypoactivity in chicks in the open-field behavioral paradigm. Only the high dose of chlorpyrifos (4mg/kg, orally) given repeatedly for 7 days caused significant cholinesterase inhibition in the whole brain (37%) and the liver (22%). In conclusion, chlorpyrifos at single or short-term repeated doses-induced behavioral changes in 7-15 days old chicks, in a model that could be used for further neurobehavioral studies involving subtle effects of organophosphates on chicks.

  4. LD to IC

    CERN Multimedia

    Association du personnel

    2010-01-01

    LC to IC – Publication of posts: Following the publication of new LD to IC posts, we regret that a large number of post descriptions are not available in both CERN official languages, English and French. Consequently, the Staff Association has decided to provide assistance to those who need it with the translation of one or more posts of interest. To do this, please contact the Staff Association secretariat, tel. 72819 or 72761 or 74224.

  5. Toxicity of binary chemical munition destruction products: methylphosphonic acid, methylphosphinic acid, 2-diisopropylaminoethanol, DF neutralent, and QL neutralent.

    Science.gov (United States)

    Watson, Rebecca E; Hafez, Ahmed M; Kremsky, Jonathan N; Bizzigotti, George O

    2007-01-01

    This paper reports the toxicity and environmental impact of neutralents produced from the hydrolysis of binary chemical agent precursor chemicals DF (methylphosphonic difluoride) and QL (2-[bis(1-methylethyl)amino]ethyl ethyl methylphosphonite). Following a literature review of the neutralent mixtures and constituents, basic toxicity tests were conducted to fill data gaps, including acute oral and dermal median lethal dose assays, the Ames mutagenicity test, and ecotoxicity tests. For methylphosphonic acid (MPA), a major constituent of DF neutralent, the acute oral LD(50) in the Sprague-Dawley rat was measured at 1888 mg/kg, and the Ames test using typical tester strains of Salmonella typhimurium and Escherichia coli was negative. The 48-h LC(50) values for pH-adjusted DF neutralent with Daphnia magna and Cyprinodon variegatus were > 2500 mg/L and 1593 mg/L, respectively. The acute oral LD(50) values in the rat for QL neutralent constituents methylphosphinic acid (MP) and 2-diisopropylaminoethanol (KB) were both determined to be 940 mg/kg, and the Ames test was negative for both. Good Laboratory Practice (GLP)-compliant ecotoxicity tests for MP and KB gave 48-h D. magna EC(50) values of 6.8 mg/L and 83 mg/L, respectively. GLP-compliant 96-h C. variegatus assays on MP and KB gave LC(50) values of 73 and 252 mg/L, respectively, and NOEC values of 22 and 108 mg/L. QL neutralent LD(50) values for acute oral and dermal toxicity tests were both > 5000 mg/kg, and the 48-h LD(50) values for D. magna and C. variegatus were 249 and 2500 mg/L, respectively. Using these data, the overall toxicity of the neutralents was assessed.

  6. Cartap and carbofuran induced alterations in serum lipid profile of Wistar rats.

    Science.gov (United States)

    Rai, Devendra K; Rai, Prashant Kumar; Gupta, Aradhna; Watal, Geeta; Sharma, Bechan

    2009-04-01

    Wistar rats of 6-8 weeks in age weighing between 120-150 g were exposed to the fixed doses of each of the carbamate pesticides such as cartap (50% LD(50)) and carbofuran (50% LD(50)) as well as a combination of these two with 25% LD(50) of each for one week. The effect of treatments was studied in terms of serum lipid parameters such as high-density lipoprotein, total cholesterol, triglyceride, low-density lipoprotein and very low-density lipoprotein. Treatment with individual doses of carbofuran (50% LD(50)) and cartap (50 % LD(50)) caused significant alterations in the levels of serum lipid parameters. The pesticides treatment resulted in marked decrease in the level of serum high-density lipoprotein where as that of other lipids got significantly elevated. Further, the rats exhibited relatively higher impact of pesticides when treated with the compounds in combination (25 % LD(50) of each). The results indicated that these compounds when used together may exert enhanced effect on the levels of serum lipids in rat.

  7. An improved brine shrimp larvae lethality microwell test method.

    Science.gov (United States)

    Zhang, Yi; Mu, Jun; Han, Jinyuan; Gu, Xiaojie

    2012-01-01

    This article described an improved brine shrimp larvae lethality microwell test method. A simply designed connecting vessel with alternative photoperiod was used to culture and collect high yield of active Artemia parthenogenetica nauplii for brine shrimp larvae lethality microwell test. Using this method, pure A. parthenogenetica nauplii suspension was easily cultured and harvested with high density about 100-150 larvae per milliliter and the natural mortality was reduced to near zero by elimination of unnecessary artificial disturbance. And its sensitivity was validated by determination of LC(50)-24 h of different reference toxicants including five antitumor agents, two pesticides, three organic pollutants, and four heavy metals salts, most of which exhibited LC(50)-24 h between 0.07 and 58.43 mg/L except for bleomycin and mitomycin C with LC(50)-24 h over 300 mg/L.

  8. Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Becce, Fabio [University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Universite Catholique Louvain, Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Ben Salah, Yosr; Berg, Bruno C. vande; Lecouvet, Frederic E.; Omoumi, Patrick [Universite Catholique Louvain, Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Verdun, Francis R. [University of Lausanne, Institute of Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Meuli, Reto [University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland)

    2013-07-15

    To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %. (orig.)

  9. Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction

    International Nuclear Information System (INIS)

    Becce, Fabio; Ben Salah, Yosr; Berg, Bruno C. vande; Lecouvet, Frederic E.; Omoumi, Patrick; Verdun, Francis R.; Meuli, Reto

    2013-01-01

    To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %. (orig.)

  10. Soluble factor(s) from bone marrow cells can rescue lethally irradiated mice by protecting endogenous hematopoietic stem cells.

    Science.gov (United States)

    Zhao, Yi; Zhan, Yuxia; Burke, Kathleen A; Anderson, W French

    2005-04-01

    Ionizing radiation-induced myeloablation can be rescued via bone marrow transplantation (BMT) or administration of cytokines if given within 2 hours after radiation exposure. There is no evidence for the existence of soluble factors that can rescue an animal after a lethal dose of radiation when administered several hours postradiation. We established a system that could test the possibility for the existence of soluble factors that could be used more than 2 hours postirradiation to rescue animals. Animals with an implanted TheraCyte immunoisolation device (TID) received lethal-dose radiation and then normal bone marrow Lin- cells were loaded into the device (thereby preventing direct interaction between donor and recipient cells). Animal survival was evaluated and stem cell activity was tested with secondary bone marrow transplantation and flow cytometry analysis. Donor cell gene expression of five antiapoptotic cytokines was examined. Bone marrow Lin- cells rescued lethally irradiated animals via soluble factor(s). Bone marrow cells from the rescued animals can rescue and repopulate secondary lethally irradiated animals. Within the first 6 hours post-lethal-dose radiation, there is no significant change of gene expression of the known radioprotective factors TPO, SCF, IL-3, Flt-3 ligand, and SDF-1. Hematopoietic stem cells can be protected in lethally irradiated animals by soluble factors produced by bone marrow Lin- cells.

  11. Effect of combined treatments of neutron radiation and plant growth regulator (GA) on seed germination and growth of rice

    International Nuclear Information System (INIS)

    Xie Chonghua; Wang Dan; Chen Yongjun; Wang Ying; Luo Jie; Liao Wei; Zheng Chun

    2007-01-01

    Rice seeds were irradiated with fast-neutron impulse pile and then were treated with different concentration of GA 3 . The effect of combined treatments on seeds germination and seedling growth were studied. The results showed that lethal pouring dose of neutron radiation on Hongai B and CB was 486 x 10 10 /cm 2 , Mianhui 2009 was 900 x 10 10 /cm 2 and Mianhui 2095 and Minghui 63 were 1350 x 10 10 /cm 2 . Semi-lethal pouring dose (LD 50 ) of neutron radiation on Hongai Band CB was 198-486 x 10 10 /cm 2 , Mianhui 2009 was about 486 x 10 10 /cm 2 , Minghui 63 was 629.49 x 10 10 /cm 2 and Mianhui 2095 is 774.69 x 10 10 /cm 2 . Radiation sensitivity of rice is Hongai B, CB>Mianhui 2009>Minghui 63>Mianhui 2095. GA 3 is a kind of efficient chemical radiation protection. 40 and 80 mg/L are the proper GA 3 concentrations of neutron irradiated rice seeds. (authors)

  12. Testing of selected pharmacological agents for capturing waterfowl [Annual Progress Report

    Science.gov (United States)

    Cline, D.R.

    1970-01-01

    The response of game-farm mallards (Frost strain) to seven pharmacological immobilizing agents was evaluated in Phase I of a planned four-phase study. A limited amount of testing was also done with wild mallards. Single dosages were administered to determine the mean effective dose (ED50) and mean lethal dose (LD50), The therapeutic index, or safety factor (LD50/ED50), and palatability were also established. Optimum dosage rates of compounds administered orally on baits were not considered in this phase of the study. Compounds were-administered by intubation and calculated in terms of mg/kg. All except one compound produced narcosis within 5 minutes at the effective dose rate.Immobilization periods for the seven compounds ranged from 7-24 minutes, and recovery periods from 1.0-6.5 hours. Such wide variations in actions of the compounds can be attributed to a compound's rate of absorption, the ease with which it passes the blood-brain barrier, its solubility in tissues, and its rate of metabolism in the liver and kidneys. Length of both the immobilization and recovery periods were extended when dosages were increased. There was no delayed mortality among survivors with any of the seven compounds at either the ED50 or LD50. Females were generally more sensitive to the anesthetizing agents than males. The ED50 for wild mallards was substantially higher than that for the experimental game-farm birds for the two compounds on which this was tested.Tribromoethanol (Avertin of Winthrop Laboratories) satisfied all test criteria an Phase I and will be subjected to more intensive investigation in ensuing tests. Thiopental sodium (Pentothal of Amdal Company) and pentobarbital sodium (Nembutal of Abbott Laboratories) were judged to be marginal. Although their therapeutic indexes were good (5.00), recovery periods were prolonged and toxic convulsions occurred at medium to high dose rates as the LD50 was approached.Alpha-chloralose (Fisher Scientific) proved least promising of

  13. Construction and Verification of PLC LD-programs by LTL-specification

    Directory of Open Access Journals (Sweden)

    E. V. Kuzmin

    2013-01-01

    Full Text Available An approach to construction and verification of PLC LD-programs for discrete problems is proposed. For the specification of the program behavior, we use the linear-time temporal logic LTL. Programming is carried out in the LD-language (Ladder Diagram according to an LTL-specification. The correctness analysis of an LTL-specification is carried out by the symbolic model checking tool Cadence SMV. A new approach to programming and verification of PLC LD-programs is shown by an example. For a discrete problem, we give a LD-program, its LTL-specification and an SMV-model. The purpose of the article is to describe an approach to programming PLC, which would provide a possibility of LD-program correctness analysis by the model checking method. Under the proposed approach, the change of the value of each program variable is described by a pair of LTL-formulas. The first LTL-formula describes situations which increase the value of the corresponding variable, the second LTL-formula specifies conditions leading to a decrease of the variable value. The LTL-formulas (used for speci- fication of the corresponding variable behavior are constructive in the sense that they construct the PLC-program (LD-program, which satisfies temporal properties expressed by these formulas. Thus, the programming of PLC is reduced to the construction of LTLspecification of the behavior of each program variable. In addition, an SMV-model of a PLC LD-program is constructed according to LTL-specification. Then, the SMV-model is analysed by the symbolic model checking tool Cadence SMV.

  14. Dominant lethal and ovarian effects of plutonium-239 in female mice

    International Nuclear Information System (INIS)

    Searle, A.G.; Beechey, C.V.; Green, D.; Howells, G.R.

    1982-01-01

    (C3H x 101)F 1 female mice were injected intravenously with 239 Pu in trisodium citrate, then mated in pairs to strain CBA males, to test for dominant lethality. In the first experiment 10μCi kg -1 and in the second 20μCi kg -1 body mass was injected. Matings were after 6 days in the first experiment (estimated ovarian absorbed dose of 0.1 Gy) and after 3,6 or 12 weeks in the second (estimated ovarian doses of 1.11, 2.45 and 5.91 Gy respectively). No evidence of dominant lethal induction was found in the first experiment, but in the second there was a significant increase over controls in pre-implantation loss in all three series. Post-implantation lethality increased significantly (by 12%) only after 12 weeks' exposure. With the 6- and 12-week exposures (especially the latter) luteal counts fell, fewer females becoming pregnant than in controls. This is attributed to oocyte killing by the α-particles. Histological and autoradiographic investigations showed a marked reduction in ovarian size and follicular numbers with fission-tracks clustered mainly over the medullary stroma. The preimplantation loss may stem from lowered fertilization of oocytes because of their damage, so that the best measure of dominant lethality is that based on post-implantation death. (author)

  15. Determining lethal dose of gamma radiation on different stages of Tribolium Cosmonauts H b s t

    International Nuclear Information System (INIS)

    Zolfagharieh, H.R.; Majd, F.; Torshyzie, M.; Babaie, M.

    1992-10-01

    Pest infestation causes great losses to stored grain through out the world. This is specially true in developing countries where the technology is less advanced, and climatic conditions are extremely favourable for the development of pests. Irradiation is on approved method of direct control for stored-product insect in wheat and wheat flour in many countries, and in dictation are that it will soon be approved for all grain, grain products and other dry food commodities. Radiation doses required to kill or sterilized the most important storage pests in all stages are known. However irradiation is very effective in preventing insect development and in producing sterility. A detailed analysis of the radiosensitivity of stored-product insects shows the different groups of pests have very different sensitivities and quarantine doses can be tailored to kill or sterilize the species of quarantine concern. The effect of irradiation on insects are many, and varied, depending primarily on the species, stage, age and physical factors. The aim is to survey the effect of gamma radiation on stored pest, which can categorized under following classes: 1-The effect of gamma radiation on different stages grow of tribolium castaneum (H B S T); 2-Determination of lethal doses.; 3-The study of gamma radiation on products. In summary these information indicated that fairly low dosages of gamma radiation could be used on commodities such as bulk grain in which some infestation by insect stages of irradiation would be required on products such package foods where hundred percent mortality must be obtain. (author)

  16. Substantial dose reduction in modern multi-slice spiral computed tomography (MSCT)-guided craniofacial and skull base surgery

    International Nuclear Information System (INIS)

    Widmann, G.; Fasser, M.; Jaschke, W.; Bale, R.; Schullian, P.; Zangerl, A.; Puelacher, W.; Kral, F.; Riechelmann, H.

    2012-01-01

    Purpose: Reduction of the radiation exposure involved in image-guided craniofacial and skull base surgery is an important goal. The purpose was to evaluate the influence of low-dose protocols in modern multi-slice spiral computed tomography (MSCT) on target registration errors (TREs). Materials and Methods: An anthropomorphic skull phantom with target markers at the craniofacial bone and the anterior skull base was scanned in Sensation Open (40-slice), LightSpeed VCT (64-slice) and Definition Flash (128-slice). Identical baseline protocols (BP) at 120 kV/100 mAs were compared to the following low-dose protocols (LD) in care dose/dose modulation: (LD-I) 100 kV/35ref. mAs, (LD-II) 80 kV/40 - 41ref. mAs, and (LD-III) 80 kV/15 - 17ref. mAs. CTDIvol and DLP were obtained. TREs using an optical navigation system were calculated for all scanners and protocols. Results were statistically analyzed in SPSS and compared for significant differences (p ≤ 0.05). Results: CTDIvol for the Sensation Open/LightSpeed VCT/Definition Flash showed: (BP) 22.24 /32.48 /14.32 mGy; (LD-I) 4.61 /3.52 /1,62 mGy; (LD-II) 3.15 /2.01 /0.87 mGy; and (LD-III) na/0.76 /0.76 mGy. Differences between the BfS (Bundesamt fuer Strahlenschutz) reference CTDIvol of 9 mGy and the lowest CTDIvol were approximately 3-fold for Sensation Open, and 12-fold for the LightSpeed VCT and Definition Flash. A total of 33 registrations and 297 TRE measurements were performed. In all MSCT scanners, the TREs did not significantly differ between the low-dose and the baseline protocols. Conclusion: Low-dose protocols in modern MSCT provided substantial dose reductions without significant influence on TRE and should be strongly considered in image-guided surgery. (orig.)

  17. Induced Mutation in Strawberry by Using Gamma Radiation

    International Nuclear Information System (INIS)

    Phadvibulya, Valailak; Puripanyavanich, Vichai; Pipattanawongse, Narongchai; Yeesawasdi, Voravit; Teja, Waich

    2003-12-01

    The culture of strawberry plants variety Tio ga were irradiated with gamma rays at doses of 0, 20, 40, 60, 80, 100,120 and 140 Gy. They were transferred to the MS medium supplemented with BA 0.1 mg/l. It was found that radiation dose which caused 50% lethality (LD 50 ) was 80 Gy. The survival plants were transferred to rooting medium (MS medium) and then transplanted to field for stolon production and yield investigation. Two lines with good fruit quality were obtained after selection till M 1 V 5 . They were planted for further testing. In experiment II, The culture of strawberry plants varieties Royal 20, Royal 70, SM and Dover were irradiated with gamma rays at doses of 0, 40 and 60 Gy. They were transplanted to field for stolon and yield production. Three lines from Royal 70 were obtained after selection till M 1 V 4 . In experiment III, the culture of strawberry plants varieties Royal 20, Royal 50, Royal 70, Nyoho and Selva were irradiated with gamma rays at the same doses as experiment II. Nine lines from Royal 70 and four lines from Nyoho with good characters were selected for further testing

  18. Students classified as LD who received course substitutions for the college foreign language requirement: a replication study.

    Science.gov (United States)

    Sparks, Richard L; Philips, Lois G; Javorsky, James

    2002-01-01

    This replication study examined whether 158 college students classified as learning disabled (LD) who were granted course substitutions for the foreign language (FL) requirement would display significant cognitive and academic achievement differences when grouped by levels of IQ-achievement and achievement-achievement discrepancy and by level of performance on an FL aptitude test (Modern Language Aptitude Test; MLAT), phonological/orthographic processing measures, and in FL courses. The results showed that there were few differences among groups with differing levels of IQ-achievement or achievement-achievement discrepancy (i.e., 1.50 SD) on MLAT and American College Testing (ACT) scores, graduating grade point average (GPA), or college FL GPA. The results also showed that between groups who scored at or above versus below the 15th percentile (i.e., or = 1.0 SD) for classification as LD. These findings suggest that many traditional assumptions about LD and FL learning are likely to be false.

  19. Safety of methionine, a novel biopesticide, to adult and larval honey bees (Apis mellifera L.).

    Science.gov (United States)

    Weeks, Emma N I; Schmehl, Daniel R; Baniszewski, Julie; Tomé, Hudson V V; Cuda, James P; Ellis, James D; Stevens, Bruce R

    2018-03-01

    Methionine is an essential/indispensible amino acid nutrient required by adult and larval honey bees (Apis mellifera L. [Hymenoptera: Apidae]). Bees are unable to rear broods on pollen deficient in methionine, and reportedly behaviorally avoid collecting pollen or nectar from florets deficient in methioinine. In contrast, it has been demonstrated that methionine is toxic to certain pest insects; thus it has been proposed as an effective biopesticide. As an ecofriendly integrated pest management agent, methionine boasts a novel mode of action differentiating it from conventional pesticides, while providing non-target safety. Pesticides that minimize collateral effects on bees are desirable, given the economic and ecological concerns about honey bee health. The aim of the present study was to assess the potential impact of the biopesticide methionine on non-target adult and larval honey bees. Acute contact adult toxicology bioassays, oral adult assessments and chronic larval toxicity assessments were performed as per U.S. Environmental Protection Agency (EPA) requirements. Our results demonstrated that methionine fits the U.S. EPA category of practically nontoxic (i.e. lethal dose to 50% mortality or LD 50 > 11µg/bee) to adult honey bees. The contact LD 50 was > 25µg/bee and the oral LD 50 was > 100µg/bee. Mortality was observed in larval bees that ingested DL-methionine (effective concentration to 50% mortality or EC 50 560µg/bee). Therefore, we conclude that methionine poses little threat to the health of the honey bee, due to unlikely exposure at concentrations shown to elicit toxic effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Effect of low doses of ionizing radiation, azoxystrobin and selected heavy metals on the model organism of species Artemia franciscana; Posobenie nizkych davok ionizujuceho ziarenia, azoxystrobinu a vybranych tazkych kovov na modelovy organizmus druhu Artemia franciscana

    Energy Technology Data Exchange (ETDEWEB)

    Spalkova, M.; Danova, D. [Univerzita veterinarskeho lekarstva a farmacie, Katedra biologie a genetiky, Ustav biologie, zoologie a radiobiologie, 04181 Kosice (Slovakia); Falis, M. [Univerzita veterinarskeho lekarstva a farmacie, Katedra farmakologie a toxikologie, Ustav toxikologie, 04181 Kosice (Slovakia); Zdarsky, M. [Veterinarni a farmaceuticka univerzita Brno, Ustav biochemie, chemie a biofyziky, 61242 Brno (Czech Republic)

    2013-04-16

    The aim of our study was to observe the effect of low doses of ionizing radiation, azoxystrobin, zinc and chrome on the lethality of Artemia franciscana. Significant increase of the lethality was observed after 72 and 96 hours of exposure to azoxystrobin and chrome as well as to azoxystrobin, chrome and irradiation. On the other hand, we observed significant decrease of the lethality in the groups exposed to pesticide and chrome or pesticide and zinc in combination with ionizing radiation with the dose of 50 Gy at time interval of 96 hours in comparison to non-irradiated groups. (authors)

  1. Dose-rate models for human survival after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1986-01-01

    This paper reviews new estimates of the L 50 in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD 50 s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively

  2. Susceptibility to cartap-induced lethal effect and diaphragmatic injury via ocular exposure in rabbits.

    Science.gov (United States)

    Liao, Jiunn-Wang; Pang, Victor Fei; Jeng, Chian-Ren; Chang, Shao-Kuang; Hwang, Jenn-Sheng; Wang, Shun-Cheng

    2003-11-05

    Cartap is extensively used to control agricultural pests. Pertinent literatures have indicated that it causes no eye irritation [D.E. Ray, Insecticides derived from plants and other organisms, in: W.J. Hayes, E.R. Laws (Eds.), Handbook of Insecticide Toxicology, Classes of Insecticides, vol. 2, Academic Press, New York, 1991, p. 611; C. Tomlin, Cartap, in: C. Tomlin (Ed.), The Insecticide Manual, 12th ed., British Crop Protection Council, Surrey, UK, 2000, p. 144]; however, the instillation of a little cartap through the eye has caused death in rabbits. The aim of this study was to determine the ocular toxicity of cartap in New Zealand White rabbits. Cartap was directly instilled into the low conjunctival sac of eyes, at doses of 0, 5, 7.5, 10 and 12.5 mg/kg body weight. The changes in the enzymes and isoenzymes of creatine kinase (CK), lactate dehydrogenase (LD), as well as pathological changes in the muscles of the heart, thigh and diaphragm were determined in the cartap-treated rabbits. Moreover, the neuromuscular effect of cartap was examined using the isolated rabbit phrenic-nerve diaphragm model. The results indicated that rabbits developed severe signs and they died within 20 min of ocular instillation. The ocular LD50 of cartap was 8.1 mg/kg body weight. Treatment with cartap increased the activities of CK and LD enzymes and their isoenzymes, CK-1, CK-2, and CK-3 in serum, and CK-3 and LD-5 in the diaphragm. Microscopically, hypercontraction bands and the rupture of myofibers of the diaphragm were observed in dead rabbits. Cartap did not affect nerve-evoked twitch but induced irreversible contracture and twitch depression on the isolated rabbit's diaphragm. These results indicate that the rabbit is susceptible to cartap toxicity; the effect of cartap caused contracture and damage to the diaphragm might play a pivotal role in respiratory paralysis and death of rabbits during intoxication.

  3. Low-Dose Involved-Field Radiation in the Treatment of Non-Hodgkin Lymphoma: Predictors of Response and Treatment Failure

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Andrea L., E-mail: alrusso@partners.org [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Chen, Yu-Hui [Biostatistics Core, Dana Farber Cancer Institute, Boston, Massachusetts (United States); Martin, Neil E.; Vinjamoori, Anant; Luthy, Sarah K. [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Freedman, Arnold [Department of Hematologic Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Michaelson, Evan M.; Silver, Barbara; Mauch, Peter M.; Ng, Andrea K. [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

    2013-05-01

    Purpose: To investigate clinical and pathologic factors significant in predicting local response and time to further treatment after low-dose involved-field radiation therapy (LD-IFRT) for non-Hodgkin lymphoma (NHL). Methods and Materials: Records of NHL patients treated at a single institution between April 2004 and September 2011 were retrospectively reviewed. Low-dose involved-field radiation therapy was given as 4 Gy in 2 fractions over 2 consecutive days. Treatment response and disease control were determined by radiographic studies and/or physical examination. A generalized estimating equation model was used to assess the effect of tumor and patient characteristics on disease response. A Cox proportional hazards regression model was used to assess time to further treatment. Results: We treated a total of 187 sites in 127 patients with LD-IFRT. Histologies included 66% follicular, 9% chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma, 10% marginal zone, 6% mantle cell lymphoma (MCL), and 8% other. Median follow-up time was 23.4 months (range, 0.03-92.2 months). The complete response, partial response, and overall response rates were 57%, 25%, and 82%, respectively. A CLL histology was associated with a lower response rate (odds ratio 0.2, 95% confidence interval 0.1-0.5, P=.02). Tumor size, site, age at diagnosis, and prior systemic therapy were not associated with response. The median time to first recurrence was 13.6 months. Those with CLL and age ≤50 years at diagnosis had a shorter time to further treatment for local failures (hazard ratio [HR] 3.63, P=.01 and HR 5.50, P=.02, respectively). Those with CLL and MCL had a shorter time to further treatment for distant failures (HR 11.1 and 16.3, respectively, P<.0001). Conclusions: High local response rates were achieved with LD-IFRT across most histologies. Chronic lymphocytic leukemia and MCL histologies and age ≤50 years at diagnosis had a shorter time to further treatment after LD-IFRT.

  4. Comparison of the lethal effects of chemical warfare nerve agents across multiple ages.

    Science.gov (United States)

    Wright, Linnzi K M; Lee, Robyn B; Vincelli, Nicole M; Whalley, Christopher E; Lumley, Lucille A

    2016-01-22

    Children may be inherently more vulnerable than adults to the lethal effects associated with chemical warfare nerve agent (CWNA) exposure because of their closer proximity to the ground, smaller body mass, higher respiratory rate, increased skin permeability and immature metabolic systems. Unfortunately, there have only been a handful of studies on the effects of CWNA in pediatric animal models, and more research is needed to confirm this hypothesis. Using a stagewise, adaptive dose design, we estimated the 24h median lethal dose for subcutaneous exposure to seven CWNA in both male and female Sprague-Dawley rats at six different developmental times. Perinatal (postnatal day [PND] 7, 14 and 21) and adult (PND 70) rats were more susceptible than pubertal (PND 28 and 42) rats to the lethal effects associated with exposure to tabun, sarin, soman and cyclosarin. Age-related differences in susceptibility were not observed in rats exposed to VM, Russian VX or VX. Published by Elsevier Ireland Ltd.

  5. Antitoxin activity of aqueous extract of Cyclea peltata root against Naja naja venom.

    Science.gov (United States)

    Sivaraman, Thulasi; Sreedevi, N S; Meenatchisundaram, S; Vadivelan, R

    2017-01-01

    Snakebites are a significant and severe global health problem. Till date, anti-snake venom serum is the only beneficial remedy existing on treating the snakebite victims. As antivenom was reported to induce early or late adverse reactions to human beings, snake venom neutralizing potential for Cyclea peltata root extract was tested for the present research by ex vivo and in vivo approaches on Naja naja toxin. Ex vivo evaluation of venom toxicity and neutralization assays was carried out. The root extracts from C. peltata were used to evaluate the Ex vivo neutralization tests such as acetylcholinesterase, protease, direct hemolysis assay, phospholipase activity, and procoagulant activity. Gas chromatography-mass spectrometry (GC-MS) analysis from root extracts of C. peltata was done to investigate the bioactive compounds. The in vivo calculation of venom toxicity (LD 50 ) of N. naja venom remained to be 0.301 μg. C. peltata root extracts were efficiently deactivated the venom lethality, and effective dose (ED 50 ) remained to be 7.24 mg/3LD 50 of N. naja venom. C. peltata root extract was found effective in counteracting all the lethal effects of venom. GC-MS analysis of the plant extract revealed the presence of antivenom compounds such as tetradecanoic and octadecadienoic acid which have neutralizing properties on N. naja venom. The result from the ex vivo and in vivo analysis indicates that C. peltata plant root extract possesses significant compounds such as tetradecanoic acid hexadecanoic acid, heptadecanoic acid, and octadecadienoic acid which can counteract the toxins present in N. naja .

  6. LD2SNPing: linkage disequilibrium plotter and RFLP enzyme mining for tag SNPs

    Directory of Open Access Journals (Sweden)

    Cheng Yu-Huei

    2009-06-01

    Full Text Available Abstract Background Linkage disequilibrium (LD mapping is commonly used to evaluate markers for genome-wide association studies. Most types of LD software focus strictly on LD analysis and visualization, but lack supporting services for genotyping. Results We developed a freeware called LD2SNPing, which provides a complete package of mining tools for genotyping and LD analysis environments. The software provides SNP ID- and gene-centric online retrievals for SNP information and tag SNP selection from dbSNP/NCBI and HapMap, respectively. Restriction fragment length polymorphism (RFLP enzyme information for SNP genotype is available to all SNP IDs and tag SNPs. Single and multiple SNP inputs are possible in order to perform LD analysis by online retrieval from HapMap and NCBI. An LD statistics section provides D, D', r2, δQ, ρ, and the P values of the Hardy-Weinberg Equilibrium for each SNP marker, and Chi-square and likelihood-ratio tests for the pair-wise association of two SNPs in LD calculation. Finally, 2D and 3D plots, as well as plain-text output of the results, can be selected. Conclusion LD2SNPing thus provides a novel visualization environment for multiple SNP input, which facilitates SNP association studies. The software, user manual, and tutorial are freely available at http://bio.kuas.edu.tw/LD2NPing.

  7. Effect of lethal and sub-lethal concentrations of tobacco (Nicotiana ...

    African Journals Online (AJOL)

    Lethal and sub-lethal bioassays on Clarias gariepinus were conducted to evaluate the toxicity of tobacco (Nicotiana tobaccum) leaf dust on weight gain and haematological indices of Clarias gariepinus (mean weight 10.5±0.70g) in glass aquaria with aeration system. The concentrations used during the lethal exposure are: ...

  8. Stem cell factor enhances the survival of murine intestinal stem cells after photon irradiation

    International Nuclear Information System (INIS)

    Leigh, B.R.; Khan, W.; Hancock, S.L.

    1995-01-01

    Recombinant rat stem cell factor (SCF) has been shown to decrease lethality in mice exposed to total-body irradiation (TBI) in the lower range of lethality through radioprotection of hematopoietic stem cells and acceleration of bone marrow repopulation. This study evaluates the effect of SCF on the survival of the intestinal mucosal stem cell after TBI. This non-hematopoietic cell is clinically relevant. Gastrointestinal toxicity is common during and after abdominal and pelvic radiation therapy and limits the radiation dose in these regions. As observed with bone marrow, the administration of SCF to mice prior to TBI enhanced the survival of mouse duodenal crypt stem cells. The maximum enhancement of survival was seen when 100 μ/kg of SCF was given intraperitoneally 8 h before irradiation. This regimen increased the survival of duodenal crypt stem cells after 12.0 Gy TBI from 22.5 ± 0.7 per duodenal cross section for controls to 30.0 ± 1.7 after treatment with SCF (P=0.03). The TBI dose producing 50% mortality of 6 days (LD 50/6 ) was increased from 14.9 Gy for control mice to 19.0 Gy for mice treated with SCF (dose modification factor = 1.28). These findings demonstrate that SCF (dose modification factor = 1.28). These findings demonstrate that SCF has radioprotective effects on a non-hematopoietic stem cell population and suggest that SCF may be of clinical value in preventing radiation injury to the intestine. 29 refs., 4 figs

  9. Lethal and mutagenic effects of XeCl laser radiation on Escherichia coli bacteria

    International Nuclear Information System (INIS)

    Tiflova, O.A.; Karu, T.J.; Furzikov, N.P.; Karbysheva, E.A.

    1987-01-01

    The survival rate and reversion to tryptophan-independence of Escherichia coli after XeCl laser irradiation (λ=308 nm) within the dose range deom 10 3 to 10 5 J/m 2 have been studied to show that LD 37 is 10 4 J/m 2 , the survival rate at a maximum dose of 10 5 J/m 2 is 1 per cent, and the number of mutants per 10 6 cells survived is 100

  10. Protection of melanized Cryptococcus neoformans from lethal dose gamma irradiation involves changes in melanin's chemical structure and paramagnetism.

    Directory of Open Access Journals (Sweden)

    Abdelahad Khajo

    Full Text Available Certain fungi thrive in highly radioactive environments including the defunct Chernobyl nuclear reactor. Cryptococcus neoformans (C. neoformans, which uses L-3,4-dihydroxyphenylalanine (L-DOPA to produce melanin, was used here to investigate how gamma radiation under aqueous aerobic conditions affects the properties of melanin, with the aim of gaining insight into its radioprotective role. Exposure of melanized fungal cell in aqueous suspensions to doses of γ-radiation capable of killing 50 to 80% of the cells did not lead to a detectable loss of melanin integrity according to EPR spectra of melanin radicals. Moreover, upon UV-visible (Xe-lamp illumination of melanized cells, the increase in radical population was unchanged after γ-irradiation. Gamma-irradiation of frozen cell suspensions and storage of samples for several days at 77 K however, produced melanin modification noted by a reduced radical population and reduced photoresponse. More direct evidence for structural modification of melanin came from the detection of soluble products with absorbance maxima near 260 nm in supernatants collected after γ-irradiation of cells and cell-free melanin. These products, which include thiobarbituric acid (TBA-reactive aldehydes, were also generated by Fenton reagent treatment of cells and cell-free melanin. In an assay of melanin integrity based on the metal (Bi(+3 binding capacity of cells, no detectable loss in binding was detected after γ-irradiation. Our results show that melanin in C. neoformans cells is susceptible to some damage by hydroxyl radical formed in lethal radioactive aqueous environments and serves a protective role in melanized fungi that involves sacrificial breakdown.

  11. In vivo assessment of the hepatotoxicity of a new Nostoc isolate from the Nile River: Nostoc sp. strain NRI.

    Science.gov (United States)

    Abu-Serie, Marwa M; Nasser, Nermine; Abd El-Wahab, Abeer; Shehawy, Rehab; Pienaar, Harrison; Baddour, Nahed; Amer, Ranya

    2018-03-01

    Nostoc sp. is one of the most widely distributed cyanobacterial genera that produce potentially protein phosphatase (PP) inhibitor; microcystins (MCs). MCs have posed a worldwide concern due to predominant hepatotoxicity to human health. We have previously isolated a Nostoc strain (NR1) from the Nile River (the main water supply in Egypt) and this strain exerted production of rare and highly toxic MC; demethylated microcystin-LR. There is no data concerning risk factors of liver diseases for human and animal exposure to NR1-contaminated drinking water yet. It is thus important to evaluate acute (LD 50 dose), subacute (0.01% and 10% of LD 50 dose) and subchronic (0.01% and 10% of LD 50 dose) hepatotoxicity's NR1 extract using experimental mice. Mice groups, who orally received 0.01% LD 50 , represented a permissible concentration of the World Health Organization (WHO) for MC in drinking water. Several parameters were detected, including hepatotoxicity (i.e. PP activity, liver function, oxidative stress markers and DNA fragmentation), pro-inflammatory cytokine (TNF-α) and liver histopathology. Our results demonstrated LD 50 of NR1 extract was at 15,350 mg/kg body weight and caused hepatotoxicity that attributed to PP inhibition and a significant increase of hepatic damage biomarkers with lipid accumulation. Moreover, NR1 extract induced hepatic oxidative damage that may have led to DNA fragmentation and production of TNF-α. As demonstrated from the histopathological study, NR1 extract caused a severe collapse of cytoskeleton with subsequent focal degeneration of hepatocytes, necroinflammation and steatosis. The grade of hepatotoxicity in subacute (10% of LD 50 ) group was higher than that in the subchronic (10% of LD 50 and 0.01% of LD 50 , WHOch, respectively) groups. No significant hepatotoxicity was detectable for subacute (0.01% of LD 50 , WHOac) group. NR1 is therefore considered as one of the harmful and life-threatening cyanobacteria for Egyptian people

  12. Design of high precision temperature control system for TO packaged LD

    Science.gov (United States)

    Liang, Enji; Luo, Baoke; Zhuang, Bin; He, Zhengquan

    2017-10-01

    Temperature is an important factor affecting the performance of TO package LD. In order to ensure the safe and stable operation of LD, a temperature control circuit for LD based on PID technology is designed. The MAX1978 and an external PID circuit are used to form a control circuit that drives the thermoelectric cooler (TEC) to achieve control of temperature and the external load can be changed. The system circuit has low power consumption, high integration and high precision,and the circuit can achieve precise control of the LD temperature. Experiment results show that the circuit can achieve effective and stable control of the laser temperature.

  13. Interaction of Low Doses of Ionizing Radiation, Potassium Dichromate and Cadmium Chloride in Artemia franciscana Biotest

    Directory of Open Access Journals (Sweden)

    K. Beňová

    2007-01-01

    Full Text Available The influence of cadmium chloride (at concentrations of 100 and 200 mg l-1 and potassium dichromate (at a concentration of 50 mg l-1 along with the effect of gamma radiation 60Co (at a dose of 10 and 50 Gy on lethality to Artemia franciscana was investigated. Four different interactions were studied, namely, those of potassium dichromate and gamma radiation, cadmium chloride and gamma radiation, and combinations of potassium dichromate and cadmium chloride in interaction with gamma radiation. A significant (α = 0.05 decrease was observed in lethality due to exposure to radiation (10 Gy in comparison with action of only potassium dichromate and cadmium chloride or their combination without exposure to gamma rays. These results support the theory of hormesis.

  14. Reproductive-phase and interphase lethal cell damage after irradiation and treatment with cytostatics

    International Nuclear Information System (INIS)

    Hagemann, G.

    1979-01-01

    After X-ray irradiation of manual cells, two lethal fractions occur due to reproductive and interphase death under low and high radiation doses. The damage kinetics on which this fact is based is compared with hypothetical tumour frequencies and leucemia induction caused in experiments. The reproductive-lethal damage can be manifested by means of colony size spectrometry, with the median colony size class differences (MCD) serving as measure for the damage found. The simultaneous effects of the cytostatics BLEOMYCIN or ICRF 159 and X-rays on reproductive lethal and interphase-lethal damage are measured by means of MCD and survival fraction, and the additive and intensifying effect' is judged with the help of suitably defined terms. This shows that the clinically used ICRF 159 has an additive effect on interphase-lethal and a sub-additive effect on reproductive-lethal cell damage. Thus, favourable results may be expected for the electivity factor in fractionated irradiation and with regard to delayed damage in healthy tissue. (orig.) 891 MG/orig. 892 RDG [de

  15. Design of LD in-band direct-pumping side surface polished micro-rod Nd:YVO4 laser

    International Nuclear Information System (INIS)

    Zhang Wen-Qi; Wang Fei; Liu Qiang; Gong Ma-Li

    2016-01-01

    To diminish the thermal load, two ways, that is, in-band direct pumping and micro-rod crystal, could be adopted at the same time. The efficiency of LD in-band direct-pumping side surface polished micro-rod Nd:YVO 4 laser is numerically analyzed. By optimizing parameters such as crystal length, laser mode radius, pump beam radius, doping concentration and crystal cross-section size, the overall efficiency can reach over 50%. It is found that with micro-rod crystal implemented in the laser oscillator, high overall efficiency LD in-band direct-pumping Nd:YVO 4 laser could be realized. High efficiency combined with low thermal load makes this laser an outstanding scheme for building high-power Nd:YVO 4 lasers. (paper)

  16. Optimal Mutagen Doses for Emiliania huxleyi

    Science.gov (United States)

    Byrne, P.

    2016-02-01

    Emiliania huxleyi (E. huxleyi) is one of the most prominent coccolithophores. Given favorable conditions, E. huxleyi blooms can reach sizes exceeding 100,000km2, with densities of 107 cells per L (Olson & Strom 2002). With increasing demand and limited supply of fossil fuels, it has become increasingly popular to look toward alternative renewable fuel sources. E. Huxleyi store energy predominately as uniquely structured polyunsaturated long chain (C37-39) alkenes, alkenones and alkenoates (abbreviated as PULCAs) (Eltgroth et al 2005). Unlike the stored energy of macroalgae and higher order plants, triacylglycerols (TAGs), PULCAs provide a similar composition to native petroleum crude oils (Yamane 2013), which offers a more cost effective and higher yielding extraction process (Wu et al 1999). A number of factors have been shown to influence the alkenone content of E. huxleyi, such as nitrogen deficiency, phosphate limitation (Li et al 2014), and temperature (Shiraiwa et al 2005). For these reasons E. huxleyi has the potential to be an attractive system for algal biofuel. The broad and long-term objective of our research is to elucidate the alkenone biosynthesis pathway in E. Huxleyi, using random mutagenesis techniques. We propose to use UV light and methylmethane sulfonate (MMS) to create a mutant population, from which clones unable to synthesize alkenones will be selected. Identifying genes whose specific mutations underlie the loss-of-function phenotype will then reveal genes of interest. The aim of this research was to determine the UV and MMS dose response rates for E. huxleyi to ascertain optimal doses defined as a 50% survival rate for each of the two mutagens. Preliminary data indicate that E. huxleyi appear to be highly sensitive to UV mutagenesis, with an LD50 of 0.57mJ/cm2 for the calcifying strain M217 and 0.96mJ/cm2 for the non-calcifying strain CCMP1516. Both calcifying and non-calcifying strains exhibit similar LD50 values for MMS at 1-2% (v/v).

  17. [The activity of blood cholinesterase in rats exposed to dimehypo].

    Science.gov (United States)

    Wan, Weiguo; Xu, Mailing; Zou, Hejian; Lu, Ailing; Shen, Xinyu; Chen, Yuming

    2002-12-01

    To determine whether and to what degree the activity of cholinesterase(ChE) is inhibited by dimehypo at different doses of dimehypo [scientific name: 2-dimethylamine-1,3-bi(sodium hyposulfit)]. Rats were dosed with dimehypo or methamidophos orally, and were randomly divided into four subgroups according to the pesticide doses, which were 1/16, 1/8, 1/4 and 1/2 of LD50 respectively(the LD50 of dimethypo and methamidophos is 342 mg/kg and 20 mg/kg respectively). The activity of ChE in blood was determined before and 30 min, 1, 2, 4 and 24 h after exposure. The modified Ellman Method was employed to measure the activity of ChE. 1/16 LD50 dose of dimehypo did not affect the activity of ChE. When the dose increased, the activity of ChE decreased accordingly. 1/2 LD50 dose of dimehypo inhibited the activity of ChE by 35.9% compared with that of control group(P dimehypo at various doses was significantly lower than that in the rats dosed with corresponding doses of methamidophos(P dimehypo may inhibit the activity of ChE. However, as compared with methamidophos, dimehypo is a weaker inhibitor of ChE.

  18. Preliminary assays for lemongrass essential oil ecotoxicological test in D. similis and C. silvestrii submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gimiliani, Giovana T.; Rogero, Sizue O.; Rogero, Jose R., E-mail: gtgimiliani@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Culturas Celulares

    2011-07-01

    Pharmaceutical products are of great interest in ecotoxicological studies due to being found some of these products in the superficial waters and sediments, water and sewage treatment effluents. It was verified an increase of insect repellent chemical products in the aquatic environment because of the increase of diseases transmitted by mosquitoes like dengue. As these compounds show toxicity, the use of essential oils natural products with repellent properties is increasing and the literature about the impact in the aquatic environment is scarce. The hydric frame would suffer natural radiation and radiations from energy generation nuclear plants impacts fall out of tests and nuclear accidents. There is no universal definition of environmental protection and there are few studies on radiation effects in the aquatic environment. In this study was determined the lemon grass essential oil toxicity level as well as the lethal dose of ionizing radiation, LD{sub 50}, in aquatic organisms. Cytotoxicity test was performed by in vitro neutral red uptake method in NCTC clone L929 cell line. In the LD{sub 50} test aquatic organisms were submitted to gamma radiation. The essential oil of lemongrass Cymbopogon flexuosus showed cytotoxicity index IC{sub 50} about 50{mu}g.mL{sup -1}. The LD{sub 50} for Daphnia similis was 242 Gy and Ceriodaphnia silvestrii about 525 Gy. Studies will be continued with acute and chronic ecotoxicological tests of lemongrass essential oil in natural organisms and in organisms submitted to gamma radiation, utilizing the results obtained in this work. (author)

  19. Adaptation of Lorke's method to determine and compare ED50 values: the cases of two anticonvulsants drugs.

    Science.gov (United States)

    Garrido-Acosta, Osvaldo; Meza-Toledo, Sergio Enrique; Anguiano-Robledo, Liliana; Valencia-Hernández, Ignacio; Chamorro-Cevallos, Germán

    2014-01-01

    We determined the median effective dose (ED50) values for the anticonvulsants phenobarbital and sodium valproate using a modification of Lorke's method. This modification allowed appropriate statistical analysis and the use of a smaller number of mice per compound tested. The anticonvulsant activities of phenobarbital and sodium valproate were evaluated in male CD1 mice by maximal electroshock (MES) and intraperitoneal administration of pentylenetetrazole (PTZ). The anticonvulsant ED50 values were obtained through modifications of Lorke's method that involved changes in the selection of the three first doses in the initial test and the fourth dose in the second test. Furthermore, a test was added to evaluate the ED50 calculated by the modified Lorke's method, allowing statistical analysis of the data and determination of the confidence limits for ED50. The ED50 for phenobarbital against MES- and PTZ-induced seizures was 16.3mg/kg and 12.7mg/kg, respectively. The sodium valproate values were 261.2mg/kg and 159.7mg/kg, respectively. These results are similar to those found using the traditional methods of finding ED50, suggesting that the modifications made to Lorke's method generate equal results using fewer mice while increasing confidence in the statistical analysis. This adaptation of Lorke's method can be used to determine median letal dose (LD50) or ED50 for compounds with other pharmacological activities. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. The novel nomogram of Gleason sum upgrade: possible application for the eligible criteria of low dose rate brachytherapy.

    Science.gov (United States)

    Budäus, Lars; Graefen, Markus; Salomon, Georg; Isbarn, Hendrik; Lughezzani, Giovanni; Sun, Maxine; Chun, Felix K H; Schlomm, Thorsten; Steuber, Thomas; Haese, Alexander; Koellermann, Jens; Sauter, Guido; Fisch, Margit; Heinzer, Hans; Huland, Hartwig; Karakiewicz, Pierre I

    2010-10-01

    To examine the rate of Gleason sum upgrading (GSU) from a sum of 6 to a Gleason sum of ≥7 in patients undergoing radical prostatectomy (RP), who fulfilled the recommendations for low dose rate brachytherapy (Gleason sum 6, prostate-specific antigen ≤10 ng/mL, clinical stage ≤T2a and prostate volume ≤50 mL), and to test the performance of an existing nomogram for prediction of GSU in this specific cohort of patients. The analysis focused on 414 patients, who fulfilled the European Society for Therapeutic Radiation and Oncology and American Brachytherapy Society criteria for low dose rate brachytherapy (LD-BT) and underwent a 10-core prostate biopsy followed by RP. The rate of GSU was tabulated and the ability of available clinical and pathological parameters for predicting GSU was tested. Finally, the performance of an existing GSU nomogram was explored. The overall rate of GSU was 35.5%. When applied to LD-BT candidates, the existing nomogram was 65.8% accurate versus 70.8% for the new nomogram. In decision curve analysis tests, the new nomogram fared substantially better than the assumption that no patient is upgraded and better than the existing nomogram. GSU represents an important issue in LD-BT candidates. The new nomogram might improve patient selection for LD-BT and cancer control outcome by excluding patients with an elevated probability of GSU. © 2010 The Japanese Urological Association.

  1. Antimalarial efficacy of Albizia lebbeck (Leguminosae) against Plasmodium falciparum in vitro & P. berghei in vivo.

    Science.gov (United States)

    Kalia, Shagun; Walter, Neha Sylvia; Bagai, Upma

    2015-12-01

    Albizia lebbeck Benth. (Leguminosae) has long been used in Indian traditional medicine. The current study was designed to test antimalarial activity of ethanolic bark extract of A. lebbeck (EBEAL). EBEAL was prepared by soxhlet extraction and subjected to phytochemical analysis. The extract was evaluated for its in vitro antimalarial activity against Plasmodium falciparum chloroquine (CQ) sensitive (MRC2) and CQ resistant (RKL9) strains. Cytotoxicity (CC 50 ) of extract against HeLa cells was evaluated. Median lethal dose (LD 50 ) was determined to assess safety of EBEAL in BALB/c mice. Schizonticidal (100-1000 mg/kg) and preventive (100-750 mg/kg) activities of EBEAL were evaluated against P. berghei. Curative activity (100-750 mg/kg) of extract was also evaluated. Phytochemical screening revealed presence of alkaloids, flavonoids, phenols, saponins, terpenes and phytosterols. The extract exhibited IC 50 of 8.2 µg/ml (MRC2) and 5.1 µg/ml (RKL9). CC 50 of extract on HeLa cell line was calculated to be >1000 µg/ml. EBEAL showed selectivity indices (SI) of >121.9 and >196.07 against MRC2 and RKL9 strains of P. falciparum, respectively. LD 50 of EBEAL was observed to be >5 g/kg. Dose-dependent chemosuppression was observed with significant ( p50 >100 mg/kg. Significant (P50 mg/kg concentration of extract on D7. The present investigation reports antiplasmodial efficacy of EBEAL in vitro against P. falciparum as evident by high SI values. ED 50 of <100 mg/kg against P. berghei categorizes EBEAL as active antimalarial. Further studies need to be done to exploit its antiplasmodial activity further.

  2. The Asd+-DadB+ Dual-Plasmid System Offers a Novel Means To Deliver Multiple Protective Antigens by a Recombinant Attenuated Salmonella Vaccine

    Science.gov (United States)

    Xin, Wei; Wanda, Soo-Young; Zhang, Xiangmin; Santander, Javier; Scarpellini, Giorgio; Ellis, Karen; Alamuri, Praveen

    2012-01-01

    We developed means to deliver multiple heterologous antigens on dual plasmids with non-antibiotic-resistance markers in a single recombinant attenuated vaccine strain of Salmonella enterica serotype Typhimurium. The first component of this delivery system is a strain of S. Typhimurium carrying genomic deletions in alr, dadB, and asd, resulting in obligate requirements for diaminopimelic acid (DAP) and d-alanine for growth. The second component is the Asd+-DadB+ plasmid pair carrying wild-type copies of asdA and dadB, respectively, to complement the mutations. To evaluate the protection efficacy of the dual-plasmid vaccine, S. Typhimurium strain χ9760 (a strain with multiple attenuating mutations: Δasd Δalr ΔdadB ΔrecF) was transformed with Asd+ and DadB+ plasmids specifying pneumococcal antigens PspA and PspC, respectively. Both plasmids were stable in χ9760 for 50 generations when grown in nonselective medium. This was significantly (P < 0.05) greater than the stability seen in its recF+ counterpart χ9590 and could be attributed to reduced interplasmid recombination in χ9760. Oral immunization of BALB/c mice with 1 × 109 CFU of χ9760 (carrying Asd+-PspA and DadB+-PspC plasmids) elicited a dominant Th1-type serum IgG response against both antigens and protected mice against intraperitoneal challenge with 200 50% lethal doses (LD50s) of virulent Streptococcus pneumoniae strain WU2 or intravenous challenge with 100 LD50s of virulent S. pneumoniae strain L81905 or intranasal challenge with a lethal dose of S. pneumoniae A66.1 in a pneumonia model. Protection offered by χ9760 was superior to that offered by the mixture of two strains, χ9828 (Asd+-PspA) and χ11026 (DadB+-PspC). This novel dual-plasmid system marks a remarkable improvement in the development of live bacterial vaccines. PMID:22868499

  3. The Asd(+)-DadB(+) dual-plasmid system offers a novel means to deliver multiple protective antigens by a recombinant attenuated Salmonella vaccine.

    Science.gov (United States)

    Xin, Wei; Wanda, Soo-Young; Zhang, Xiangmin; Santander, Javier; Scarpellini, Giorgio; Ellis, Karen; Alamuri, Praveen; Curtiss, Roy

    2012-10-01

    We developed means to deliver multiple heterologous antigens on dual plasmids with non-antibiotic-resistance markers in a single recombinant attenuated vaccine strain of Salmonella enterica serotype Typhimurium. The first component of this delivery system is a strain of S. Typhimurium carrying genomic deletions in alr, dadB, and asd, resulting in obligate requirements for diaminopimelic acid (DAP) and d-alanine for growth. The second component is the Asd(+)-DadB(+) plasmid pair carrying wild-type copies of asdA and dadB, respectively, to complement the mutations. To evaluate the protection efficacy of the dual-plasmid vaccine, S. Typhimurium strain χ9760 (a strain with multiple attenuating mutations: Δasd Δalr ΔdadB ΔrecF) was transformed with Asd(+) and DadB(+) plasmids specifying pneumococcal antigens PspA and PspC, respectively. Both plasmids were stable in χ9760 for 50 generations when grown in nonselective medium. This was significantly (P < 0.05) greater than the stability seen in its recF(+) counterpart χ9590 and could be attributed to reduced interplasmid recombination in χ9760. Oral immunization of BALB/c mice with 1 × 10(9) CFU of χ9760 (carrying Asd(+)-PspA and DadB(+)-PspC plasmids) elicited a dominant Th1-type serum IgG response against both antigens and protected mice against intraperitoneal challenge with 200 50% lethal doses (LD(50)s) of virulent Streptococcus pneumoniae strain WU2 or intravenous challenge with 100 LD(50)s of virulent S. pneumoniae strain L81905 or intranasal challenge with a lethal dose of S. pneumoniae A66.1 in a pneumonia model. Protection offered by χ9760 was superior to that offered by the mixture of two strains, χ9828 (Asd(+)-PspA) and χ11026 (DadB(+)-PspC). This novel dual-plasmid system marks a remarkable improvement in the development of live bacterial vaccines.

  4. Radiation dose reduction in digital breast tomosynthesis (DBT) by means of deep-learning-based supervised image processing

    Science.gov (United States)

    Liu, Junchi; Zarshenas, Amin; Qadir, Ammar; Wei, Zheng; Yang, Limin; Fajardo, Laurie; Suzuki, Kenji

    2018-03-01

    To reduce cumulative radiation exposure and lifetime risks for radiation-induced cancer from breast cancer screening, we developed a deep-learning-based supervised image-processing technique called neural network convolution (NNC) for radiation dose reduction in DBT. NNC employed patched-based neural network regression in a convolutional manner to convert lower-dose (LD) to higher-dose (HD) tomosynthesis images. We trained our NNC with quarter-dose (25% of the standard dose: 12 mAs at 32 kVp) raw projection images and corresponding "teaching" higher-dose (HD) images (200% of the standard dose: 99 mAs at 32 kVp) of a breast cadaver phantom acquired with a DBT system (Selenia Dimensions, Hologic, CA). Once trained, NNC no longer requires HD images. It converts new LD images to images that look like HD images; thus the term "virtual" HD (VHD) images. We reconstructed tomosynthesis slices on a research DBT system. To determine a dose reduction rate, we acquired 4 studies of another test phantom at 4 different radiation doses (1.35, 2.7, 4.04, and 5.39 mGy entrance dose). Structural SIMilarity (SSIM) index was used to evaluate the image quality. For testing, we collected half-dose (50% of the standard dose: 32+/-14 mAs at 33+/-5 kVp) and full-dose (standard dose: 68+/-23 mAs at 33+/-5 kvp) images of 10 clinical cases with the DBT system at University of Iowa Hospitals and Clinics. NNC converted half-dose DBT images of 10 clinical cases to VHD DBT images that were equivalent to full dose DBT images. Our cadaver phantom experiment demonstrated 79% dose reduction.

  5. Biostatnet workshop on Biomedical (Big) Data & DoReMi LD-RadStats: Workshop for statisticians interested in contributing to EU low dose radiation research

    CERN Document Server

    Calle, MLuz; Cardis, Elisabeth; Einbeck, Jochen; Gómez, Guadalupe; Puig, Pere

    2017-01-01

    This two-part volume gathers extended conference abstracts corresponding to selected talks from the "Biostatnet workshop on Biomedical (Big) Data" and from the "DoReMi LD-RadStats: Workshop for statisticians interested in contributing to EU low dose radiation research", which were held at the Centre de Recerca Matemàtica (CRM) in Barcelona from November 26th to 27th, 2015, and at the Institut de Salut Global ISGlobal (former CREAL) from October 26th to 28th, 2015, respectively. Most of the contributions are brief articles, presenting preliminary new results not yet published in regular research journals. The first part is devoted to the challenges of analyzing so called "Biomedical Big Data", tremendous amounts of biomedical and health data that are generated every day due to the use of recent technological advances such as massive genomic sequencing, electronic health records or high-resolution medical imaging, among others. The analysis of this information poses significant challenges for researchers in th...

  6. Effects of sublethal doses of chlorfluazuron on the ovarian ...

    African Journals Online (AJOL)

    AJB_YOMI

    2011-10-12

    Oct 12, 2011 ... eggs (Perveen, 2000a). The objectives of this research were to determine the effects of sublethal doses of chlorfluazuron (LD10or LD30) on the amounts of ovarianprotein, lipid, carbohydrates, DNA, and RNA, and ecdysteroid titres in different developmental stages of S. litura, a major crop pest around the ...

  7. Desinfestação de Averrhoa carambola infestada por Anastrepha obliqua (Macquart, 1835 (diptera -Tephritidae através de radiação gama Desinfestation of Averrhoa carambola infested with Anastrepha obliqua (mac. 1835 (diptera - Tephritidae using gamma radiation

    Directory of Open Access Journals (Sweden)

    V. Arthur

    1994-08-01

    Full Text Available O experimento teve por objetivo determinar a dose de desinfestação para Averrhoa carambola infestada por larvas de Anastrepha obliqua. Para realização do experimento coletou-se frutos do campo e fez-se urna amostragem prévia, constatando-se que cada fruta continha em média 11 larvas de último instar do referido inseto praga. Esses frutos foram irradiados com as seguintes doses de radiação gama: 0 (test., 50, 150, 300, 600 e 900 Gy. Cada tratamento constou de 3 repetições num total de 9 frutas e aproximadamente 99 larvas por tratamento. Após a irradiação as frutas foram colocadas em câmara climatizada com 25 ± 5°C de temperatura e umidade relativa de 70 ± 5% onde aguardou-se que as larvas deixassem os frutos e se transformassem em pupas e posteriormente em adultos. Pelos resultados obtidos concluiu-se que a dose letal para (LD100 para larvas em frutos de carambola foi 600 Gy e a que impediu a emergência dos adultos foi a de 50 Gy.The aim of this experiment was to determine the desinfestation dose of gamma radiation in Averrhoa carambola infested with larvae of Anastrepha obliqua. Fruits were collected in the field, each having about 11 larvae in the last instar. Fruits were irradiated with the following gamma radiation doses: 0 (control, 50, 150, 300, 600 and 900 Gy. Each treatment consisted of 9 fruits (3 replications giving the amount of 99 larvae for each treatment. After irradiation the fruits were kept in a climatic chamber with the temperature adjusted to 25 ± 5°C and relative humidity of 70 ± 5%, until larvae left the fruit and became transformed into pupae and adults. The lethal dose (LD100 of gamma radiation for larvae in the fruits was 600 Gy and the dose of 50 Gy inhibited completely the total emergency of adults.

  8. New dose-mortality data based on 3-D radiation shielding calculation for concrete buildings at Nagasaki

    International Nuclear Information System (INIS)

    Rhoades, W.A.; Childs, R.L.; Ingersoll, D.T.

    1988-01-01

    The analysis of radiation doses received during the World War II attack on Nagasaki provides an important source of biochemical information. More than 40 years after the war, it has been possible to make a satisfactory calculation of the doses to personnel inside reinforced concrete buildings by use of a 3-dimensional discrete ordinates code, TORT. The results were used to deduce a new value of the LD50 parameter that is in good agreement with traditional values. The new discrete ordinates software appears to have potential application to conventional radiation transport calculations as well. 9 refs., 3 figs., 2 tabs

  9. Acute oral toxicity of 3-MCPD mono- and di-palmitic esters in Swiss mice and their cytotoxicity in NRK-52E rat kidney cells.

    Science.gov (United States)

    Liu, Man; Gao, Bo-Yan; Qin, Fang; Wu, Ping-Ping; Shi, Hai-Ming; Luo, Wei; Ma, Ai-Niu; Jiang, Yuan-Rong; Xu, Xue-Bing; Yu, Liang-Li Lucy

    2012-10-01

    The acute oral toxicity of 1-palmitoyl-3-chloropropanediol (3-MCPD 1-monopalmitate) and 1,2-bis-palmitoyl-3-chloropropanediol (3-MCPD dipalmitate) in Swiss mice were examined, along with their cytotoxicity in NRK-52E rat kidney cells. LD50 (median lethal dose) value of 3-MCPD 1-monopalmitate was determined 2676.81 mg/kg body weight (BW). The results showed that 3-MCPD 1-monopalmitate dose-dependently decreased the mean body weight, and caused significant increase of serum urea nitrogen and creatinine in dead mice compared to the control and survived mice. Major histopathological changes in mice fed 3-MCPD 1-monopalmitate were renal tubular necrosis, protein casts and spermatids decrease in the seminiferous tubules. According to the limit test for 3-MCPD dipalmitate, LD50 value of 3-MCPD dipalmitate was presumed to be greater than 5000 mg/kg BW. Obvious changes were not observed on mean body weight, absolute and relative organ weight or serum urea nitrogen and creatinine levels in mice fed 3-MCPD dipalmitate. However, renal tubular necrosis, protein casts and spermatids decrease were also observed in the dead mice. In addition, MTT and LDH assay results only showed the cytotoxicity of 3-MCPD 1-monopalmitate in NRK-52E rat kidney cells in a dose-dependent manner. Together, the results indicated a greater toxicity of 3-MCPD 1-monopalmitate compared to 3-MCPD dipalmitate. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Lethality Index 2008-2014: Less shootings, same lethality, more opacity

    Directory of Open Access Journals (Sweden)

    Carlos Silva Forné

    2017-11-01

    Full Text Available This article evaluates the use of lethal force by Mexican federal security forces during shootings with presumed members of organized crime from 2008-2014. The authors use official data and press reports on deaths and wounded in shootings to construct indicators such as the number of dead civilians over the number of dead officials from the federal security forces and the number of dead civilians over the number of wounded civilians. In a context where certain factors that contribute to an excessive use of force become more common, the results of the study show a growing use of lethal force. This raises questions over the possible excessive use of lethal force as a normal or systematic practice. The study also shows a growing context of opacity in the information available to evaluate the use of lethal force and the general lack of a legal framework to regulate the use of lethal force in Mexico.

  11. Mechanisms of thallium-201 myocardial accumulation

    International Nuclear Information System (INIS)

    Wackers, F.J.Th.; Samson, G.

    1980-01-01

    The practical advantages of 201 Tl over other suitable myocardial imaging agents such as potassium-43 ( 43 K), rubidium-81 ( 81 Rb), and cesium-129 ( 129 Cs), are its relatively low energy photons which makes it possible to employ high-resolution low-energy collimators and its physical half-life of 73 hr which provides sufficiently long shelf-life for practical clinical imaging. Toxicological considerations do not play a role using 201 Tl as thallous chloride. The concentration of thallous chloride in a dose of 2 mCi of 201 Tl is less than 4μg. The LD 50 of thallous chloride is a factor 10 4 more. The minimal lethal dose in man is reported to be 12 mg/kg. The kinetics of 201 Tl, its tissue distributions and radiation doses are assessed, and the effect of cardiac drugs on thallium-201 uptake are discussed. (Auth.)

  12. Acute toxicity of four anticholinesterase insecticides to American kestrels, eastern screech-owls and northern bobwhites

    Science.gov (United States)

    Wiemeyer, Stanley N.; Sparling, D.W.

    1991-01-01

    American kestrels (Falco sparverius), eastern screech-owls (Otus asio), and northern bobwhites (Colinus virginianus) were given single acute oral doses of four widely diverse anticholinesterase pesticides: EPN, fenthion, carbofuran, and monocrotophos. LD50s, based on birds that died within 5 d of dosage, were computed for each chemical in each species. Sex differences in the sensitivity of northern bobwhites in reproductive condition were examined. American kestrels were highly sensitive to all chemicals tested (LD50s 0.6--4.0 mg/kg). Eastern screech-owls were highly tolerant to EPN (LD50 274 mg/kg) but sensitive to the remaining chemicals (LD50s 1.5-3.9 mg/kg). Northern bobwhites were highly sensitive to monocrotophos (LD50 0.8 mg/kg) and less sensitive to the remaining chemicals (LD50s 4.6--31 mg/kg). Female bobwhites (LD50 3.1 mg/kg) were more sensitive to fenthion than males (LD50 7.0 mg/kg). Mean percent depression of brain cho[inesterase (ChE) of birds that died on the day of dosing exceeded 65% for all chemicals in all species. The response of one species to a given pesticide should not be used to predict the sensitivity of other species to the same pesticide. The need for research on several topics is discussed

  13. Dose-rate models for human survival after exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1986-01-01

    This paper reviews new estimates of the L/sub 50/ in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD/sub 50/s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively.

  14. Strong lethality and teratogenicity of strobilurins on Xenopus tropicalis embryos: Basing on ten agricultural fungicides

    International Nuclear Information System (INIS)

    Li, Dan; Liu, Mengyun; Yang, Yongsheng; Shi, Huahong; Zhou, Junliang; He, Defu

    2016-01-01

    Agricultural chemical inputs have been considered as a risk factor for the global declines in amphibian populations, yet the application of agricultural fungicides has increased dramatically in recent years. Currently little is known about the potential toxicity of fungicides on the embryos of amphibians. We studied the effects of ten commonly used fungicides (four strobilurins, two SDHIs, two triazoles, fludioxonil and folpet) on Xenopus tropicalis embryos. Lethal and teratogenic effects were respectively examined after 48 h exposure. The median lethal concentrations (LC50s) and the median teratogenic concentrations (TC50s) were determined in line with actual exposure concentrations. These fungicides except two triazoles showed obvious lethal effects on embryos; however LC50s of four strobilurins were the lowest and in the range of 6.81–196.59 μg/L. Strobilurins, SDHIs and fludioxonil induced severe malformations in embryos. Among the ten fungicides, the lowest TC50s were observed for four strobilurins in the range of 0.61–84.13 μg/L. The teratogenicity shared similar dose–effect relationship and consistent phenotypes mainly including microcephaly, hypopigmentation, somite segmentation and narrow fins. The findings indicate that the developmental toxicity of currently-used fungicides involved with ecologic risks on amphibians. Especially strobilurins are highly toxic to amphibian embryos at μg/L level, which is close to environmentally relevant concentrations. - Highlights: • Effects of ten agricultural fungicides were tested on Xenopus tropicalis embryos. • Strobilurin fungicides showed strong lethal and teratogenic effects on embryos. • Lowest LC50 and TC50 were observed for strobilurins in ten fungicides. • μg/L level of toxic concentrations for strobilurins was environmentally relevant. • Teratogenicity shared similar dose–effect relationship and main phenotypes. - Strobilurins induced strong lethality and teratogenicity on Xenopus

  15. Anticonvulsant properties of methanol leaf extract of Laggera Aurita Linn. F. (Asteraceae) in laboratory animals.

    Science.gov (United States)

    Malami, S; Kyari, H; Danjuma, N M; Ya'u, J; Hussaini, I M

    2016-09-15

    Preparation of Laggera aurita Linn. (Asteraceae) is widely used in traditional medicine to treat various kinds of diseases such as epilepsy, malaria, fever, pain and asthma. Its efficacy is widely acclaimed among communities in Northern Nigeria. The present study is aimed at establishing the possible anticonvulsant effects of the methanol leaf extract of Laggera aurita using acute and chronic anticonvulsant models. Median lethal dose (LD50) was determined in mice and rats via oral and intraperitoneal routes. Anticonvulsant screening of the extract was performed using maximal electroshock-induced seizure test in day-old chicks; pentylenetetrazole-, strychnine- and picrotoxin- induced seizure models in mice. Similarly; its effects on pentylenetetrazole-induce kindling in rats as well as when co-administered with fluphenamic and cyproheptadine in mice, were evaluated. Median lethal dose (LD50) values were found to be >5000mg/kg, p.o. and 2154mg/kg, i.p., each for both rats and mice. The extract showed dose dependent protection against tonic hind limb extension (THLE) and significantly (p<0.05) decreased the mean recovery from seizure in the maximal electroshock-induced seizure. In the pentylenetetrazole-induced seizure model, the extract offered 50% protection at 600mg/kg and also increased the mean onset of seizure at all doses with significant (p<0.05) increase at the highest dose (600mg/kg). Similarly the extract produced significant (p<0.05) increase in the onset of seizures in both strychnine- and picrotoxin- induced seizure models, at all the doses except at 150mg/kg for the picrotoxin model. Co-administration of fluphenamic acid (FFA) (5mg/kg) and the extract (600mg/kg) showed an enhanced effect with percentage protection of 70% while co-administration of FFA (5mg/kg) and phenytoin (5mg/kg) as well phenytoin (5mg/kg) and the extract (600mg/kg) produced an additive effect. Administration of the extract (600mg/kg), phenytoin (20mg/kg) and cyproheptadine (4mg

  16. A bacterial cocaine esterase protects against cocaine-induced epileptogenic activity and lethality.

    Science.gov (United States)

    Jutkiewicz, Emily M; Baladi, Michelle G; Cooper, Ziva D; Narasimhan, Diwahar; Sunahara, Roger K; Woods, James H

    2009-09-01

    Cocaine toxicity results in cardiovascular complications, seizures, and death and accounts for approximately 20% of drug-related emergency department visits every year. Presently, there are no treatments to eliminate the toxic effects of cocaine. The present study hypothesizes that a bacterial cocaine esterase with high catalytic efficiency would provide rapid and robust protection from cocaine-induced convulsions, epileptogenic activity, and lethality. Cocaine-induced paroxysmal activity and convulsions were evaluated in rats surgically implanted with radiotelemetry devices (N=6 per treatment group). Cocaine esterase was administered 1 minute after a lethal dose of cocaine or after cocaine-induced convulsions to determine the ability of the enzyme to prevent or reverse, respectively, the effects of cocaine. The cocaine esterase prevented all cocaine-induced electroencephalographic changes and lethality. This effect was specific for cocaine because the esterase did not prevent convulsions and death induced by a cocaine analog, (-)-2beta-carbomethoxy-3beta-phenyltropane. The esterase prevented lethality even after cocaine-induced convulsions occurred. In contrast, the short-acting benzodiazepine, midazolam, prevented cocaine-induced convulsions but not the lethal effects of cocaine. The data showed that cocaine esterase successfully degraded circulating cocaine to prevent lethality and that cocaine-induced convulsions alone are not responsible for the lethal effects of cocaine in this model. Therefore, further investigation into the use of cocaine esterase for treating cocaine overdose and its toxic effects is warranted.

  17. The score statistic of the LD-lod analysis: detecting linkage adaptive to linkage disequilibrium.

    Science.gov (United States)

    Huang, J; Jiang, Y

    2001-01-01

    We study the properties of a modified lod score method for testing linkage that incorporates linkage disequilibrium (LD-lod). By examination of its score statistic, we show that the LD-lod score method adaptively combines two sources of information: (a) the IBD sharing score which is informative for linkage regardless of the existence of LD and (b) the contrast between allele-specific IBD sharing scores which is informative for linkage only in the presence of LD. We also consider the connection between the LD-lod score method and the transmission-disequilibrium test (TDT) for triad data and the mean test for affected sib pair (ASP) data. We show that, for triad data, the recessive LD-lod test is asymptotically equivalent to the TDT; and for ASP data, it is an adaptive combination of the TDT and the ASP mean test. We demonstrate that the LD-lod score method has relatively good statistical efficiency in comparison with the ASP mean test and the TDT for a broad range of LD and the genetic models considered in this report. Therefore, the LD-lod score method is an interesting approach for detecting linkage when the extent of LD is unknown, such as in a genome-wide screen with a dense set of genetic markers. Copyright 2001 S. Karger AG, Basel

  18. Insecticidal Properties of a Highly Potent Wax Isolated from Dolichandra cynanchoides Cham

    Directory of Open Access Journals (Sweden)

    Georgina Díaz Napal

    2016-08-01

    Full Text Available Bioassay-guided fractionation of an ethanolic extract of the aerial parts of Dolichandra cynanchoides Cham. (Bignoniaceae led to the isolation of a natural wax with anti-insect activity against Spodoptera frugiperda (Noctuidae and Epilachna paenulata (Coleptera. The compound was identified spectroscopically as an ester of a C27 fatty acid and a C25 alcohol, pentacosyl heptacosanoate (1. The effective doses of 1 for 50% feeding inhibition (ED50 of S. frugiperda and E. paenulata were 0.82 and 8.53 µg/cm2, respectively, in a choice test, while azadirachtin showed ED50 of 0.10 and 0.59 µg/cm2, respectively. In a no-choice test, both insects refused to feed on leaves treated with 1 at doses of 0.1 µg/cm2 or greater inhibiting larval growth and dramatically reducing survival. The lethal doses 50 (LD50 of 1 were 0.39 and 0.68 µg/cm2 for S. frugiperda and E. paenulata, respectively. These results indicate that 1 has potential for development as botanical insecticides. Similar esters might be obtainable in large quantities as many edible crops produce wax esters that are discarded during food processing. Research on these materials could lead to the detection of similar waxes with insecticidal activity.

  19. 5-Lipoxygenase Deficiency Reduces Acetaminophen-Induced Hepatotoxicity and Lethality

    Directory of Open Access Journals (Sweden)

    Miriam S. N. Hohmann

    2013-01-01

    Full Text Available 5-Lipoxygenase (5-LO converts arachidonic acid into leukotrienes (LTs and is involved in inflammation. At present, the participation of 5-LO in acetaminophen (APAP-induced hepatotoxicity and liver damage has not been addressed. 5-LO deficient (5-LO-/- mice and background wild type mice were challenged with APAP (0.3–6 g/kg or saline. The lethality, liver damage, neutrophil and macrophage recruitment, LTB4, cytokine production, and oxidative stress were assessed. APAP induced a dose-dependent mortality, and the dose of 3 g/kg was selected for next experiments. APAP induced LTB4 production in the liver, the primary target organ in APAP toxicity. Histopathological analysis revealed that 5-LO-/- mice presented reduced APAP-induced liver necrosis and inflammation compared with WT mice. APAP-induced lethality, increase of plasma levels of aspartate aminotransferase and alanine aminotransferase, liver cytokine (IL-1β, TNF-α, IFN-γ, and IL-10, superoxide anion, and thiobarbituric acid reactive substances production, myeloperoxidase and N-acetyl-β-D-glucosaminidase activity, Nrf2 and gp91phox mRNA expression, and decrease of reduced glutathione and antioxidant capacity measured by 2,2′-azinobis(3-ethylbenzothiazoline 6-sulfonate assay were prevented in 5-LO-/- mice compared to WT mice. Therefore, 5-LO deficiency resulted in reduced mortality due to reduced liver inflammatory and oxidative damage, suggesting 5-LO is a promising target to reduce APAP-induced lethality and liver inflammatory/oxidative damage.

  20. Study On In Vitro Variation Generation Of Cymbidium Labell Anna Belle By Gamma Co-60 Irradiation

    International Nuclear Information System (INIS)

    Nguyen Huynh Phuong Uyen; Vo Thi Thu Ha; Le Quang Luan

    2011-01-01

    Radiation ionization is one of useful methods for mutation breeding of plants. In this study, γ-ray (Co-60) was used for generating morphological variations of Cymbidium Labell Anna Belle. The lethal doses of 50% samples (LD 50 ) after 4 months cultivation were determined at 35.0 Gy for protocorm like bodies (PLBs), 37.4 Gy for in vitro shoot bubs and 70.1 Gy for plantlets. PLBs were found as suitable samples for generation of variation of mentioned Cymbidium. The dose range from 20 to 50 Gy was determined with a high ability of variation on C. Labell Anna Belle. The highest frequency of variation was obtained ca. 3.82 x 10 -3 at the dose of 30 Gy. 157 in vitro variant plantlets were selected in M 1 V 1 generation, among variations, the variations were mainly found with 5 following types: removal of chlorophyll (8 plantlets), the leaves become shorter (64 plantlets), the leaves become longer (64 plantlets), increase of leaf number (11 plantlets) and the colour of pericardium was changed from green into violet (10 plantlets). Twenty one variant lines were selected in M 1 V 2 generation. (author)

  1. Synthesis and radioprotective study of novel amino-alkyl dithiocarbamic acid derivatives against γ-irradiation in mice

    International Nuclear Information System (INIS)

    Hosseinimehr, S. J.; Beiki, D.; Kebriaeezadeh, A.; Khalaj, A.; Pirali Hamedani, M.; Akhlaghpoor, S.; Esmaeili, H.; Barazesh, A. R.

    2009-01-01

    The aim of this study was to evaluate the radioprotective capacity of some novel amino alkylated dithiocarbamic acid potassium salts against γ-irradiation in mice. Materials and Methods: Eight compounds containing 2-aminoethyl-, 3-aminopropyl-, 4-aminobutyl-, 5-aminopentyl-, 6-aminohexyl-, 7-amino heptyl-, 8-amino octyl and 9-amino nonyl of dithiocarbamate derivatives were prepared. Male NMRI mice were injected intraperitoneally with a geometric progression of doses (300 -1000 mg/kg), through the dose response range for lethal toxicity. To evaluate the radioprotective activity, one-half of the toxic LD 50 of each compound were injected intraperitoneally to groups of twenty mice, 30 minutes prior to γ-irradiation. The treated animals were kept for 30 days, and the lethality was recorded each day. Results: Among Eight compounds of alkyl dithiocarbamic acid derivatives, 5-aminopentyl, 7-amino heptyl, 8-amino octyl and 9-amino nonyl dithiocarbamic acid mono potassium salts are new compounds. All evaluated compounds showed a concentration dependent effect on the survival in mice. The LD 50 values were found to be more than 599 mg/kg. The percentages of 30-day survival of mice for 2-aminoethyl, 7-amino heptyl and 8-amino octyl dithiocarbamic acid derivatives were 7%, 40% and 13.5%, respectively, when injected 30 minutes before γ-irradiation. Other compounds had no radioprotective effects. Statistical analysis showed a significant difference between the treated and control groups for the 7-amino heptyl derivative (p<0.05). Conclusion: Among the compounds investigated in this study, 7-amino heptyl dithiocarbamate derivative showed more radioprotective effects in comparison with the others. Although it seems that the radioprotective effects in these derivatives correlate with the size of the alkyl chain, more experiments are required to support this hypothesis.

  2. Cadmium distribution and selected tissue histology in rats following administration of cadmium chloride and/or gamma radiation

    International Nuclear Information System (INIS)

    Kundomal, Y.R.

    1981-01-01

    Sprague-Dawley rats were injected IP with CdCl 2 or distilled water, and/or given a total-body irradiation. Three lethality studies, acute Cd, chronic Cd, and acute radiation, were performed to determine the sublethal doses for the co-insult study. Lethal doses (LD 50 ) were obtained by probit analysis. Cd concentrations were determined by the atomic absorption spectrophotometry. The analysis of variance was used to test the data. LD/sub 50(30)/ values obtained for respective male and female rats were: 5.99 and 7.13 mg/kg of body wt for acute Cd; 4.25 and 5.99 mg/kg of body wt for chronic Cd; and 733 and 729 R for acute radiation. On days 1, 7 and 21 post-irradiation, rats given Cd singly or in combination with radiation showed a high accumulation and retention of metal in the liver and kidney. Then followed in order of decreasing Cd concentrations were: spleen, intestine, stomach, heart, testis, lung, blood cells, brain, and muscle. High Cd concentrations in the liver and kidney persisted over a 21-day observation period; the concentrations in the other tissues decreased, some to control values. Radiation was not an antagonist on Cd concentrations or retentions in these tissues except the heart, in which radiation contributed to the clearance of Cd. Radiation did not act as a synergistic agent on Cd concentrations or retentions in any of the tissues analyzed. Radiation singly had no morphological or physiological effects on the parameters of this study. Based on the high Cd concentrations in these tissues, histological examinations of the liver and kidney sections were made. In the high co-insult groups slight abnormalities, such as pyknotic nuclei in the liver and cellular disorganization and larger lumens in the kidney were observed

  3. Dominant lethal mutations and histological changes produced in mouse oocytes by gamma irradiation

    International Nuclear Information System (INIS)

    Vyglenov, A.; Baev, I.; Rupova, I.; Kusheva, R.

    1976-01-01

    Mouse female were exposed to a total dose of 500 or 1000 rad 137 Cs gamma rays delivered at 0.01 rad/min. Effects were scored at 1, 5, 7, and 10 weeks after cessation of treatment. Histologically, ovaria in the 500 rad group showed a decrease up to 11% in follicle numbers as compared to controls; with the prolongation of the time after exposure, a further fall in follicle numbers is observed. In the 1000 rad group, depopulation of ovaria was complete. With the 500 rad dose, total dominant lethality was found to be increased for any of the time intervals between radiation exposure and conception; postimplantation dominant lethality was comparatively low, with similar scores between the weeks investigated. (author)

  4. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; van de Geijn, J.; Goffman, T. (ROB, DCT, NCI, NIH, Bethesda, Maryland 20892 (US))

    1991-05-01

    In the conventional linear--quadratic model of single-dose response, the {alpha} and {beta} terms reflect lethal damage created {ital during} the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD.

  5. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    International Nuclear Information System (INIS)

    Chen, J.; van de Geijn, J.; Goffman, T.

    1991-01-01

    In the conventional linear--quadratic model of single-dose response, the α and β terms reflect lethal damage created during the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with ''unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD

  6. Importance of dose metrics for lethal and sublethal sediment metal toxicity in the oligochaete worm Lumbriculus variegatus

    Energy Technology Data Exchange (ETDEWEB)

    Penttinen, O.P.; Kilpi-Koski, J.; Toivainen, K. [Helsinki Univ., Lahti (Finland). Dept. of Ecology end Environmental Sciences; Jokela, M. [Mikkeli Univ. of Applied Sciences, Mikkeli (Finland); Vaeisaenen, A. [Jyvaeskylae Univ. (Finland). Dept. of Chemistry

    2008-02-15

    Background, aims, and scope. There is an increasing demand for controlled toxicity tests to predict biological effects related to sediment metal contamination. In this context, questions of metal-specific factors, sensitivity of toxicity endpoints, and variability in exposure duration arise. In addition, the choice of the dose metrics for responses is equally important and is related to the applicability of the concept of critical body residue (CBR) in exposure assessments, as well as being the main focus of this study. Methods. Experiments were conducted to assess toxicity of Cd, Cr, Cu and Pb to the oligochaete worm Lumbriculus variegatus with the aim of determining CBRs for two response metrics. Mortality and feeding activity of worms exposed to sediment-spiked metals were used as end-points in connection with residue analyses from both the organisms and the surrounding media. Results. LC50 values were 0.3, 1.4, 5.2, and 6.7 mg/L (from 4.7 {mu}mol/L to 128.0 {mu}mol/L), and the order of toxicity, from most toxic to least toxic, was Cu > Cd > Pb>Cr. By relating toxicity to body residue, variability in toxicity among the metals decreased and the order of toxicity was altered. The highest lethal residue value was obtained for Cu (10.8 mmol/kg) and the lowest was obtained for Cd (2.3 mmol/kg). In the 10-d sublethal test, both time and metal exposure were an important source of variation in the feeding activity of worms. The significant treatment effects were observed from worms exposed to Cd or Pb, with the controls yielding the highest feeding rate. However, quantitative changes in the measured end-point did not correlate with the exposure concentrations or body residues, which remained an order of magnitude lower than in the acute exposures. (orig.)

  7. Lethal and Sub-lethal Effects of Four Insecticides on the Aphidophagous Coccinellid Adalia bipunctata (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Depalo, Laura; Lanzoni, Alberto; Masetti, Antonio; Pasqualini, Edison; Burgio, Giovanni

    2017-12-05

    Conventional insecticide assays, which measure the effects of insecticide exposure on short-term mortality, overlook important traits, including persistence of toxicity or sub-lethal effects. Therefore, such approaches are especially inadequate for prediction of the overall impact of insecticides on beneficial arthropods. In this study, the side effects of four modern insecticides (chlorantraniliprole, emamectin benzoate, spinosad, and spirotetramat) on Adalia bipunctata (L.) (Coleoptera: Coccinellidae) were evaluated under laboratory conditions by exposition on treated potted plants. In addition to investigation of acute toxicity and persistence of harmful activity in both larvae and adults of A. bipunctata, demographic parameters were evaluated, to provide a comprehensive picture of the nontarget effects of these products. Field doses of the four insecticides caused detrimental effects to A. bipunctata; but in different ways. Overall, spinosad showed the best toxicological profile among the products tested. Emamectin benzoate could be considered a low-risk insecticide, but had high persistence. Chlorantraniliprole exhibited lethal effects on early instar larvae and adults, along with a long-lasting activity, instead spirotetramat showed a low impact on larval and adult mortality and can be considered a short-lived insecticide. However, demographic analysis demonstrated that chlorantraniliprole and spirotetramat caused sub-lethal effects. Our findings highlight that sole assessment of mortality can lead to underestimation of the full impact of pesticides on nontarget insects. Demographic analysis was demonstrated to be a sensitive method for detection of the sub-lethal effects of insecticides on A. bipunctata, and this approach should be considered for evaluation of insecticide selectivity. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. LD/sub 50/ and selenium concentration in organs of rabbit following oral application of sodium selenite and toxicity verification of Ursoselevit-Praemix

    Energy Technology Data Exchange (ETDEWEB)

    Berschneider, F.; Hess, M.; Neuffer, K.; Willer, S.

    1976-07-01

    LC/sub 50/24 hr/ was established in the first of a series of experiments on 72 rabbits for orally applied sodium selenite. The dosage was 8.62 mg/kg live weight, the confidence interval being (1 - ..cap alpha.. = 0.95) +/- 0.13 mg/kg. The value was four times as high following intravenous application. Complete lethality was recorded from 15 mg Na/sub 2/SeO/sub 3//kg live weight within 21 hours. Thirty-six animals were involved in the second experiment of the series. They had 50 or 100 percent Ursoselevit-Praemix (30 ppm Se) in their rations. Body mass development of the test animals was superior to that recorded from the controls in the first 50 days, after which limit the former declined strongly in a few days. Their general condition worsened. Postmortem finding, following slaughter, included catarrhal enteritis, toxic liver dystrophy, scattered pulpous tumors in the spleen, and interstitial nephritis. In the third experiment (50 percent Ursoselevit-Praemix with 60 ppm Se in the rations), the test animals developed better than the controls during the first two months, after which point they exhibited the same clinical symptoms as those observed in the second experiment, stopped putting on weight, and eventually turned cachectic. The pathomorphological findings were identical with those obtained from the second experiment. The selenium concentrations in the organs of the test animals all were much higher than those of the controls. Their amounts in excess to base values were up to eleven times in the blood, nine times in the liver, twelve times in the kidneys, and 13 times in the muscles. 11 references, 2 figures, 2 tables.

  9. Estimation of mutation rates induced by large doses of gamma, proton and neutron irradiation of the X-chromosome of the nematode Panagrellus redivivus

    International Nuclear Information System (INIS)

    Denich, K.T.R.; Samoiloff, M.R.

    1984-01-01

    The radiation-resistant free-living nematode Panagrellus redivivus was used to study mutation rates in oocytes, following gamma, proton and neutron irradiation in the dose range 45-225 grays. γ-Radiation produced approximately 0.001 lethal X-chromosomes per gray over the range tested. Proton or neutron irradiation produced approximately 0.003 lethal X-chromosomes per gray at lower doses, with the mutation rate dropping to 0.001 lethal X-chromosome per gray at the higher doses. These results suggest a dose-dependent mutation-repair system. Cell lethality was also examined. γ-Radiation produced the greatest amount of cell lethality at all doses, while neutron irradiation had no cell lethal effect at any of the doses examined. (orig.)

  10. Clinical Pharmacokinetics of IPX066: Evaluation of Dose Proportionality and Effect of Food in Healthy Volunteers.

    Science.gov (United States)

    Yao, Hsuan-Ming; Hsu, Ann; Gupta, Suneel; Modi, Nishit B

    2016-01-01

    IPX066 is an oral, extended-release capsule formulation of carbidopa-levodopa (CD-LD) available in 4 strengths. The goals of this investigation were to assess the dose proportionality of IPX066 and to study the effects of a high-fat, high-calorie meal and of sprinkling the capsule contents on applesauce on the pharmacokinetics of IPX066 in healthy volunteers. Three open-label studies were conducted. In the first study, subjects received 1 capsule of each IPX066 strength (23.75-95, 36.25-145, 48.75-195, and 61.25-245 mg of CD-LD). In the second study, subjects received 1 and 2 capsules of IPX066 245-mg LD under fasting conditions. In the third study, subjects received 2 capsules of IPX066 245-mg LD under 3 conditions: fasting; following a high-fat, high-calorie breakfast; and with the capsule contents sprinkled on applesauce under fasting conditions. Peak plasma concentrations (Cmax) and systemic exposure (AUCt, AUCinf) for LD and CD increased dose-proportionally over the range of the IPX066 capsule strengths. Comparison of 1 and 2 IPX066 245-mg LD capsules showed dose-proportional pharmacokinetics for Cmax and AUCt. Sprinkling the capsule contents on applesauce did not affect the pharmacokinetics. A high-fat, high-calorie meal delayed the initial increase in LD concentration by approximately 1 to 2 hours, reduced Cmax by 21%, and increased AUCinf by 13% compared with the fasted state. IPX066 shows dose-proportional pharmacokinetics. Sprinkling the capsule contents on applesauce does not affect the pharmacokinetics; a high-fat, high-calorie meal delayed absorption by 1 to 2 hours, slightly reduced Cmax, and slightly increased extent of absorption.

  11. Viljandimaa ettevõtete TOP 50

    Index Scriptorium Estoniae

    2005-01-01

    Viljandimaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Viljandimaa ettevõtete üld- ja finantsandmed

  12. Jõgevamaa ettevõtete TOP 50

    Index Scriptorium Estoniae

    2005-01-01

    Jõgevamaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Jõgevamaa ettevõtete üld- ja finantsandmed

  13. Sterilizing effects and lethal effects of gamma radiation on different phases of life cycle of the sitotroga cerealella (Olivier) in rice and maize

    International Nuclear Information System (INIS)

    Arthur, V.

    1985-01-01

    The objective of this research to verify the effects of the gamma radiation on different phases of the life cycle of the gamma radiation on different phases of the life cycle of the moth grain Angoumois, Sitotroga cerealella (Olivier, 1819). For all the treatment with gamma radiation a Cobalt-60 source type Gammabeam-650 was used and the activity was approximately 3.1 x 10 sup(14) Bq., with dose rate of 3.01 kGy per hour. The LD sub(100) of gamma radiation for eggs of insects reared in rice and maize were respectively 100 Gy and 125 Gy. The sterilizing doses in adults which were irradiated at immature phases (larvae and pupae) were 100 Gy and 200 Gy in rice and 150 Gy and 250 Gy in maize, respectively. The sterilizing doses for females and males in maize were respectively 350 Gy and 500 Gy. The LD sub(100) for adult females were 4500 Gy and 4750 Gy for males, both in rice. The LD sub(100), for adult reared on maize was 4750 Gy for both sexes. (author)

  14. Acute Contact Toxicity Test of Oxalic Acid on Honeybees in the Southwestern Zone of Uruguay Prueba de Toxicidad Aguda por Contacto de Ácido Oxálico en Abejas de la Zona Sudoeste de Uruguay

    Directory of Open Access Journals (Sweden)

    Leonidas Carrasco-Letelier

    2012-06-01

    Full Text Available This work studies the acute contact toxicity of oxalic acid (OA on a honeybee polyhybrid subspecies (Apis mellifera, which is the dominant biotype in southwestern zone of Uruguay (SWZU and the country's most important honey-producing region. We determined the mean lethal dose (LD50, as well as the no observed effect level (NOEL and the lowest observed effect level (LOEL values. We also estimated the total number of honeybees per hive in the test area. The aim was to assess the relationship between the maximum OA dose used in Uruguay (3.1 g OA per hive and the toxicological parameters of honeybees from SWZU. The current dose of 3.1 g OA per hive corresponds to 132.8 OA per honeybee since determined NOEL is 400 OA per honeybee; our results indicate that the current dose could be increased to 9.3 g OA per hive. The results also highlight some differences between the LD50 value in SWZU honeybees (548.95 OA per honeybee and some published LD50 values for other honeybee subspecies.Este trabajo estudió la toxicidad aguda por contacto del ácido oxálico (AO sobre una subespecie poli-híbrida de abejas (Apis mellifera, la cual es el biotipo dominante en la zona sudoeste de Uruguay (SWZU, la región más importante para la producción de miel en este país. Este estudio determinó la dosis letal 50 (DL50, así como el nivel de efecto no observado (NOEL, el nivel de efecto mínimo observado (LOEL, y el número total de individuos por colmena. El propósito fue evaluar la relación entre la dosis máxima de AO usada en Uruguay (3.1 g AO por colmena y los parámetros toxicológicos de las abejas de la SWZU. Los resultados mostraron que es posible elevar la dosis actual de AO por colmena a 9.3 g, ya que la dosis actual de 3.1 g de AO corresponde a 132.8 AO por abeja, y el NOEL determinado es 400 AO por abeja. Los resultados también destacaron algunas diferencias entre la DL50 de las abejas del SWZU (548.95 AO por abeja y algunos valores de DL50 publicados

  15. Measurements of Chlorpyrifos Levels in Forager Bees and Comparison with Levels that Disrupt Honey Bee Odor-Mediated Learning Under Laboratory Conditions.

    Science.gov (United States)

    Urlacher, Elodie; Monchanin, Coline; Rivière, Coraline; Richard, Freddie-Jeanne; Lombardi, Christie; Michelsen-Heath, Sue; Hageman, Kimberly J; Mercer, Alison R

    2016-02-01

    Chlorpyrifos is an organophosphate pesticide used around the world to protect food crops against insects and mites. Despite guidelines for chlorpyrifos usage, including precautions to protect beneficial insects, such as honeybees from spray drift, this pesticide has been detected in bees in various countries, indicating that exposure still occurs. Here, we examined chlorpyrifos levels in bees collected from 17 locations in Otago, New Zealand, and compared doses of this pesticide that cause sub-lethal effects on learning performance under laboratory conditions with amounts of chlorpyrifos detected in the bees in the field. The pesticide was detected at 17 % of the sites sampled and in 12 % of the colonies examined. Amounts detected ranged from 35 to 286 pg.bee(-1), far below the LD50 of ~100 ng.bee(-1). We detected no adverse effect of chlorpyrifos on aversive learning, but the formation and retrieval of appetitive olfactory memories was severely affected. Chlorpyrifos fed to bees in amounts several orders of magnitude lower than the LD50, and also lower than levels detected in bees, was found to slow appetitive learning and reduce the specificity of memory recall. As learning and memory play a central role in the behavioral ecology and communication of foraging bees, chlorpyrifos, even in sublethal doses, may threaten the success and survival of this important insect pollinator.

  16. Mathematical modeling improves EC50 estimations from classical dose-response curves.

    Science.gov (United States)

    Nyman, Elin; Lindgren, Isa; Lövfors, William; Lundengård, Karin; Cervin, Ida; Sjöström, Theresia Arbring; Altimiras, Jordi; Cedersund, Gunnar

    2015-03-01

    The β-adrenergic response is impaired in failing hearts. When studying β-adrenergic function in vitro, the half-maximal effective concentration (EC50 ) is an important measure of ligand response. We previously measured the in vitro contraction force response of chicken heart tissue to increasing concentrations of adrenaline, and observed a decreasing response at high concentrations. The classical interpretation of such data is to assume a maximal response before the decrease, and to fit a sigmoid curve to the remaining data to determine EC50 . Instead, we have applied a mathematical modeling approach to interpret the full dose-response curve in a new way. The developed model predicts a non-steady-state caused by a short resting time between increased concentrations of agonist, which affect the dose-response characterization. Therefore, an improved estimate of EC50 may be calculated using steady-state simulations of the model. The model-based estimation of EC50 is further refined using additional time-resolved data to decrease the uncertainty of the prediction. The resulting model-based EC50 (180-525 nm) is higher than the classically interpreted EC50 (46-191 nm). Mathematical modeling thus makes it possible to re-interpret previously obtained datasets, and to make accurate estimates of EC50 even when steady-state measurements are not experimentally feasible. The mathematical models described here have been submitted to the JWS Online Cellular Systems Modelling Database, and may be accessed at http://jjj.bio.vu.nl/database/nyman. © 2015 FEBS.

  17. Repair of radiation injury by transplantation of hemopoietic tissue

    International Nuclear Information System (INIS)

    Smith, L.H.

    1978-01-01

    The following topics are discussed: endogenous repair of tissue by surviving cells; exogenous repair by transplantation of tissue from unirradiated donor; repair of hematopoietic tissue following sublethal exposure or exposure in the LD 1 to LD 100 range; early studies on regeneration of hematopoietic tissue in x-irradiated dogs by giving bone marrow; hypotheses as to how bone marrow injections result in regeneration of blood-forming tissue; effects of rat bone marrow transplants on survival of lethally irradiated mice; and effect of tissue transplants on dose-response curve

  18. Description of histopathological changes induced by the venom of the Persian Gulf Lionfish (Pterois russelli) in a mouse model of multiorgan toxicity.

    Science.gov (United States)

    Memar, Bahareh; Jamili, Shahla; Shahbazzadeh, Delavar; Pooshang Bagheri, Kamran

    2016-11-01

    Pterois russelli is a venomous fish belongs to Scorpaenidae family. Envenomation by the Persian Gulf lionfish is associated with local pain, marked inflammation and local heat. The present study was aimed to document the histopathological changes in liver, heart, lung, kidney and alterations in release of critical enzymes such as LDH, CK. AST, ALT and ALP induced by the administration of various doses of P. russelli venom in a mouse model. LD50 of venom was determined by intravenous injection in Balb/c mice. Histopathological alterations of lung, liver, heart and kidney following injection of one LD50, 1/2 and 1/3 LD50 doses of the venom were evaluated. Simultaneously, release of LDH, CK, AST, ALT and ALP were measured in serum following administration of 1/2 and1/3 LD50 doses of the venom too. LD50 was calculated as 10.5 mg/kg. The level of all enzymes were increased after 3 h and significantly raised after 24 h and rapidly reduced after 48 h. Histological studies showed that one LD50 and 1/2 LD50 doses of the venom induced significant histological alterations in the lungs, liver, heart and kidneys including congestion, hemorrhage, necrosis, apoptosis, edema, and infiltration of inflammatory cells. The results indicate that the venom of P. russelli has nephrotoxic, hepatotoxic, cardiotoxic and pneumotoxic effects in mouse model. Among four examined vital organs, the highest critical events were seen in liver. The findings are useful to give new insight in the fish's venom studies. Gathering the data resulted from this study together will be directed us toward a good aspect concerning the toxicity of potential therapeutic molecules in the venom of lionfish. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Reducing dosing frequency of carbidopa/levodopa: double-blind crossover study comparing twice-daily bilayer formulation of carbidopa/levodopa (IPX054) versus 4 daily doses of standard carbidopa/levodopa in stable Parkinson disease patients.

    Science.gov (United States)

    Hinson, Vanessa K; Goetz, Christopher G; Leurgans, Sue; Fan, Wenqing; Nguyen, Tiffany; Hsu, Ann

    2009-01-01

    We compared IPX054, a bilayer tablet of immediate- and extended-release carbidopa/levodopa (CD/LD) given twice daily to standard CD/LD given 4 times daily in patients with stable Parkinson disease (PD). Twelve PD patients with no or mild fluctuations on CD/LD 25/100 mg 4 times daily were randomized to a double-blind crossover comparison with IPX054 (50/200 mg) twice daily. At the end of each 2-week treatment, patients were video recorded while performing a modified Unified Parkinson's Disease Rating Scale motor examination and Rush Dyskinesia Rating Scale at 30-minute intervals over 8.5 hours. The primary outcome measure was the number of videotape epochs rated as "ON" without troublesome dyskinesia by a blinded observer (Wilcoxon signed rank tests). The 9 men and 3 women had a mean age of 69 years and mean PD duration of 6 years. IPX054 and CD/LD showed no significant differences in the primary outcome measure (mean number of video epochs rated as ON without troublesome dyskinesia; P = 0.14). The mean time to ON was improved with IPX054 (P = 0.014), and the mean modified Unified Parkinson's Disease Rating Scale scores slightly favored IPX054 (14.4 vs 16.9; P = 0.052). Mean Rush Dyskinesia Rating Scale scores were not significantly different between IPX054 and CD/LD (0.45 vs 0.69; P = 0.25). No patient developed troublesome dyskinesias. In stable PD patients, no difference was detected between twice-daily treatment with IPX054 and CD/LD given 4 times daily. In this group, substitution with IPX054 reduced dosing frequency while maintaining CD/LD efficacy. In clinical practice, this ease of administration may offer improved treatment compliance.

  20. A hepatic protein, fetuin-A, occupies a protective role in lethal systemic inflammation.

    Directory of Open Access Journals (Sweden)

    Wei Li

    2011-02-01

    Full Text Available A liver-derived protein, fetuin-A, was first purified from calf fetal serum in 1944, but its potential role in lethal systemic inflammation was previously unknown. This study aims to delineate the molecular mechanisms underlying the regulation of hepatic fetuin-A expression during lethal systemic inflammation (LSI, and investigated whether alterations of fetuin-A levels affect animal survival, and influence systemic accumulation of a late mediator, HMGB1.LSI was induced by endotoxemia or cecal ligation and puncture (CLP in fetuin-A knock-out or wild-type mice, and animal survival rates were compared. Murine peritoneal macrophages were challenged with exogenous (endotoxin or endogenous (IFN-γ stimuli in the absence or presence of fetuin-A, and HMGB1 expression and release was assessed. Circulating fetuin-A levels were decreased in a time-dependent manner, starting between 26 h, reaching a nadir around 24-48 h, and returning towards base-line approximately 72 h post onset of endotoxemia or sepsis. These dynamic changes were mirrored by an early cytokine IFN-γ-mediated inhibition (up to 50-70% of hepatic fetuin-A expression. Disruption of fetuin-A expression rendered animals more susceptible to LSI, whereas supplementation of fetuin-A (20-100 mg/kg dose-dependently increased animal survival rates. The protection was associated with a significant reduction in systemic HMGB1 accumulation in vivo, and parallel inhibition of IFN-γ- or LPS-induced HMGB1 release in vitro.These experimental data suggest that fetuin-A is protective against lethal systemic inflammation partly by inhibiting active HMGB1 release.

  1. Use of butterflies as nontarget insect test species and the acute toxicity and hazard of mosquito control insecticides.

    Science.gov (United States)

    Hoang, Tham C; Pryor, Rachel L; Rand, Gary M; Frakes, Robert A

    2011-04-01

    Honeybees are the standard insect test species used for toxicity testing of pesticides on nontarget insects for the U.S. Environmental Protection Agency (U.S. EPA) under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA). Butterflies are another important insect order and a valued ecological resource in pollination. The current study conducted acute toxicity tests with naled, permethrin, and dichlorvos on fifth larval instar (caterpillars) and adults of different native Florida, USA, butterfly species to determine median lethal doses (24-h LD50), because limited acute toxicity data are available with this major insect group. Thorax- and wing-only applications of each insecticide were conducted. Based on LD50s, thorax and wing application exposures were acutely toxic to both caterpillars and adults. Permethrin was the most acutely toxic insecticide after thorax exposure to fifth instars and adult butterflies. However, no generalization on acute toxicity (sensitivity) of the insecticides could be concluded based on exposures to fifth instars versus adult butterflies or on thorax versus wing exposures of adult butterflies. A comparison of LD50s of the butterflies from this study (caterpillars and adults) with honeybee LD50s for the adult mosquito insecticides on a µg/organism or µg/g basis indicates that several butterfly species are more sensitive to these insecticides than are honeybees. A comparison of species sensitivity distributions for all three insecticides shows that permethrin had the lowest 10th percentile. Using a hazard quotient approach indicates that both permethrin and naled applications in the field may present potential acute hazards to butterflies, whereas no acute hazard of dichlorvos is apparent in butterflies. Butterflies should be considered as potential test organisms when nontarget insect testing of pesticides is suggested under FIFRA. Copyright © 2011 SETAC.

  2. In vivo studies on detoxifying actions of aqueous bark extract of Prosopis cineraria against crude venom from Indian cobra (Naja naja

    Directory of Open Access Journals (Sweden)

    Thirunavukkarasu Sivaraman

    2013-12-01

    Full Text Available Detoxification effect of aqueous, methanol and petroleum ether extracts of medicinal plants such as Aristolochia bracteolata, Mucuna pruriens, Prosopis cineraria and Rauvolfia tetraphylla was systematically screened against lethality of crude venom of Naja naja using Swiss albino mice as animal models. We have herein demonstrated that aqueous bark extract of P. cineraria has substantial anti-venom potential vis-à-vis other extracts used in the present study. The aqueous extract at the dose of 14 mg/kg b.w. was able to almost completely neutralize the lethal activity of 3LD50 (1.12 mg/kg b.w. of the cobra venom and the extract did not cause any types of adverse side-effects to the animal models. The investigation justifies not only the veraciousness of the extract used by traditional healers of Asian subcontinent as antidotes to snake venoms and also suggests that the aqueous extract should contain specific inhibitors to most principle toxic components of the crude venom.

  3. Effects of Gamma Radiation on the Cigarette Beetle, Lasioderma serricorne (F.)

    International Nuclear Information System (INIS)

    Kongratarpon, Titima; Tauthong, Pensook; Sutantawong, Manon; Wongpiyasatid, Arune

    2003-06-01

    Effects of gamma radiation on eggs, larvae, pupae and adult stages of the cigarette beetle were studied. The LD 50 and LD 99 of gamma radiation to the eggs (7±1 days) were 327 Gy and 834 Gy respectively on the 3 rd day after irradiation. At 300 Gy the eggs were able to hatch but died in the pupal stage. None of the eggs hatched when treated with 800 Gy and other doses. The LD 50 and LD 99 to the last instar larvae (7±1 days) were 505 Gy and 1,547 Gy on the 12 th day after irradiation. The mortality of last instar larvae varied directly with the irradiation dose, no larvae could survive when irradiated at 1,500 Gy and above. At the dose lower than 1,200 Gy, some pupation was observed but no adult emergence occurred. The LD 50 and LD 99 of gamma radiation to pupae (4±1days) were 548 Gy and 1,578 Gy on the 12 th day after irradiation. The pupal mortality varied directlty with the dose. No adult emergence was obtained after irradiated at 1,500 Gy. At 300 Gy, the adults emerged with deformity and sterility. The LD 50 and LD 99 to adults (3±1 days) were 931 and 1,746 Gy respectively on the 12 th day after irradiation. The mortality of adults increased when irradiated at higher dose and none of the eggs hatched after treated adults with 300 Gy. The dosage of 300 Gy was high enough to inhibit the development of all stages. Melanization occurred in untreated young larvae after killing by freezing. Some parts of larval body became dark brown to black while the rest of the body was yellow-white or greyed-yellow. In the treated young larvae, non-melanization to slight melanization occurred at 100, 300 and 500 Gy. The degree of melanization in treated young larvae decreased with the increasing doses. In treated old larvae, the melanization increased with the increasing doses

  4. 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

  5. Radiation effects on cultured mouse embryos in relation to cell division cycle

    International Nuclear Information System (INIS)

    Domon, M.

    1982-01-01

    The authors have worked with mouse embryos in vitro asking first, what are the suitable parameters to define the radiation sensitivity of embryos, and second what is a major factor determining it. The LD 50 was adopted as a parameter of the radiation sensitivity of a population in a mouse embryo system in culture. The fertilized ova were collected into Whitten's medium at various times during the pronuclear and 2-cell stages of development. They were irradiated in chambers with X-rays at doses of 0 to 800 rads. After the embryos were cultured, a set of the lethal fractions for various X-ray doses were obtained. Regarding the radiation sensitivity variation of the embryos, the LD 50 varied from 100 to 200 rads during the pronuclear stage and from 100 to 600 rads during the 2-cell stage. The embryos during the pronuclear stage were most radioresistant at early G 2 phase, followed by an increase in the sensitivity. The embryos during the 2-cell stage were also most radioresistant at early G 2 phase and were more sensitive when they got close to either the first or the second cleavage division. Furthermore, it seems that the factor 6 of the large variation was due to the extremely long G 2 period, 14 hrs for the 2-cell embryos. That is, the pooled 2-cell embryos were in a relative sense well synchronized with G 2 phase. In contrast, the synchrony was poor during the pronuclear stage, which led to less variation of the LD 50 for the pronuclear embryos. It is concluded that during the early cleavage stages of mice, radiosensitivity is mainly governed by the content of cells of various cell cycle ages in the embryo. (Namekawa, K.)

  6. Reproductive activities of Heliotropium indicum isolate against Helopeltis theivora and toxicity evaluation in mice.

    Science.gov (United States)

    Dolui, A K; Debnath, Manabendra; De, B; Kumar, Atul

    2012-05-01

    A new compound E was isolated from the methanolic extract of the leaves of Heliotropium indicum by chromatographic fractionation. In the present study, the effect of the compound E on reproduction of Helopeltis theivora has been evaluated. The acute toxicity study (LD50) and sub-acute toxicity studies (haematological, biochemical and histopathological parameters) in albino Swiss mice were carried out to evaluate the safety aspect of the compound E. The compound showed significant inhibitory effect on the reproductive life of H. theivora. The oviposition period, fecundity and hatching percentage of H. theivora were found to be 15.67 days, 39.33 and 28.00% respectively after treatment with 2% compound E, whereas the control value were found to be 20.33 days, 77.67 and 77.33% respectively. The LD50 of the compound was found to be 780 mg kg(-1) in Swiss albino female mice. The compound did not show any toxicity in mice at sub-lethal dose treatment (78 mg kg(-1) b. wt., once daily) for 21 days as evident from different haematological, biochemical and histopathological parameters in compound E treated group when compared with control.

  7. Seaweed tablet: a natural source of iodine

    International Nuclear Information System (INIS)

    Briones, Annabelle V.; Ambal, Wilhelmina O.; Monroyo, Evangelina C.; Bonifacio, Teresita S.; Sison, Fe M.

    1997-01-01

    Species of seaweeds namely: Halymenia durvillaei, Laurencia flexilis and Sargassum gigantifolium were processed into dried form and formulated as tablet. Prior to tablet formulation, the seaweeds were assayed for iodine and trace elements. The seaweeds that exhibited significance values of iodine and trace elements were further analyzed for the presence of heavy metals followed by acute oral toxicity test (LD 50 ). Among the seaweeds evaluated, H. durvilaei was found to contain high level of iodine (0.255% w/w) and magnesium (1.65% w/w) with sufficient amount of zinc (25.69 ppm) and phosporous (11.68 ppm). Analysis of heavy metals showed minute amount of mercury (0.0055 ppm), cadmium (0.67 ppm) and lead (1.80 ppm). The median lethal dose (LD 50 ) of H. durvillaei administered orally in Swiss male mice is 119.1489 ± 4.9873 g/kg. Tablet formulation was based on the U.S. recommended daily allowance of 0.15 mg. of iodine per adult and children. The final product was comparable to imported Kelp pills (available in the local market) in terms of physical properties and iodine content. (Author)

  8. The effects of repeated low-dose sarin exposure

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  9. Use of gamma rays for in vitro mutation induction in taro

    International Nuclear Information System (INIS)

    Medero Vega, Victor R.; Lopez Torres, J.; Basail Perez, Milagros

    2015-01-01

    A methodology for genetic improvement of taro (Colocasia esculenta) for in vitro mutation induction using physical mutagens to guarantee the increased variability and the possibility of selecting superior genotypes to commercial clones with higher yield potential, better nutritional quality and response to biotic and abiotic stress was established. Irradiations were performed at the National Center for Studies Applied to Nuclear Energy (CEADEN). Nine radiation doses with Co 60 gamma rays (10, 15, 20, 25, 30, 35, 40, 50 and 60 Gy) were studied. The control was based on three clones: 'INIVIT MC-2001', 'INIVIT MC-2006' and 'INIVIT MC-2012'. 50 meristematic apices per clone were used. The survival percentages of explants were evaluated after 30 days of culture for the calculation of the dose-effect curve. The survival percentage of in vitro produced plants in field conditions and the agronomic response 9 months after plantation were evaluated. The Median Lethal Dose (LD 50 ) for the genotypes studied was 20 Gy, and doses higher than 25 Gy to cause practically 100% deaths of explants irradiated were also determined. Two possible mutants with better agronomic characteristics than the donor and better response to water stress were selected in field conditions. (Author)

  10. Low-dose CT detects more progression of bone formation in comparison to conventional radiography in patients with ankylosing spondylitis: results from the SIAS cohort.

    Science.gov (United States)

    de Koning, Anoek; de Bruin, Freek; van den Berg, Rosaline; Ramiro, Sofia; Baraliakos, Xenofon; Braun, Juergen; van Gaalen, Floris A; Reijnierse, Monique; van der Heijde, Désirée

    2018-02-01

    To compare the CT Syndesmophyte Score (CTSS) for low-dose CT (ldCT) with the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) for conventional radiographs (CR) in patients with ankylosing spondylitis (AS). Patients with AS in the Sensitive Imaging in Ankylosing Spondylitis cohort had lateral cervical and lumbar spine CR and whole spine ldCT at baseline and 2 years. CR and ldCT images were scored by two readers, paired by patient, blinded to time order, per imaging modality. For the total score analysis, we used average scores of readers per corner on CR or quadrant on ldCT. For the syndesmophyte analysis we used individual reader and consensus scores, regarding new or growing syndesmophyte at the same corner/quadrant. 50 patients were included in the syndesmophyte analysis and 37 in the total score analysis. Mean (SD) status scores for mSASSS (range 0-72) and CTSS (range 0-552) at baseline were 17.9 (13.8) and 161.6 (126.6), and mean progression was 2.4 (3.8) and 17.9 (22.1). Three times as many patients showed new or growing syndesmophytes at ≥3 quadrants on ldCT compared with ≥3 corners on CR for individual readers; for consensus this increased to five times. In 50 patients, 36 new or growing syndesmophytes are seen on CR compared with 151 on ldCT, most being found in the thoracic spine. ldCT, covering the whole spine, detects more progression in the form of new and growing syndesmophytes in patients with AS compared with CR, which is limited to the cervical and lumbar spine. Most progression occurred in the thoracic spine. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Lethality of gamma radiation and malathion to the indian meal moth, plodia interpunctella

    International Nuclear Information System (INIS)

    Eesa, N.M.; Moursy, L.E.

    1991-01-01

    The lethality of gamma radiation and the organo phosphorous insecticide, malathion, as well as the combined action of both was determined for the five larval instars of the indian meal moth, plodia interpunctella (Hubner). The younger instars were more susceptible to both gamma radiation and malathion. The L D 50 values of gamma radiation increased gradually with the instar. Malathion was highly toxic to the first four instars, but the fifth instar required a much larger dose. Gamma radiation combined with malathion at the L D 25 values was antagonistic when evaluated against each of the five larval instars of the indian meal moth. Thus, the use of gamma radiation with malathion does not seem to be a promising control strategy. However, further research investigations are needed to confirm this finding.3 tab

  12. Empirical complexities in the genetic foundations of lethal mutagenesis.

    Science.gov (United States)

    Bull, James J; Joyce, Paul; Gladstone, Eric; Molineux, Ian J

    2013-10-01

    From population genetics theory, elevating the mutation rate of a large population should progressively reduce average fitness. If the fitness decline is large enough, the population will go extinct in a process known as lethal mutagenesis. Lethal mutagenesis has been endorsed in the virology literature as a promising approach to viral treatment, and several in vitro studies have forced viral extinction with high doses of mutagenic drugs. Yet only one empirical study has tested the genetic models underlying lethal mutagenesis, and the theory failed on even a qualitative level. Here we provide a new level of analysis of lethal mutagenesis by developing and evaluating models specifically tailored to empirical systems that may be used to test the theory. We first quantify a bias in the estimation of a critical parameter and consider whether that bias underlies the previously observed lack of concordance between theory and experiment. We then consider a seemingly ideal protocol that avoids this bias-mutagenesis of virions-but find that it is hampered by other problems. Finally, results that reveal difficulties in the mere interpretation of mutations assayed from double-strand genomes are derived. Our analyses expose unanticipated complexities in testing the theory. Nevertheless, the previous failure of the theory to predict experimental outcomes appears to reside in evolutionary mechanisms neglected by the theory (e.g., beneficial mutations) rather than from a mismatch between the empirical setup and model assumptions. This interpretation raises the specter that naive attempts at lethal mutagenesis may augment adaptation rather than retard it.

  13. High-dose mode of mortality in Tribolium: A model system for study of radiation injury and repair in non-proliferative tissues

    International Nuclear Information System (INIS)

    Cheng, Chihing Christina.

    1989-01-01

    With appropriate doses of ionizing radiation, both the acute, or lethal-midlethal, dose-independent pattern of mortality, and the hyperacute, dose-dependent pattern, were demonstrated within a single insect genus (Tribolium). This demonstration provides resolution of apparently contradictory reports of insect radiation responses in terms of doses required to cause lethality and those based on survival time as a function of dose. A dose-dependent mortality pattern was elicited in adult Tribolium receiving high doses, viz., 300 Gy or greater; its time course was complete in 10 days, before the dose-independent pattern of mortality began. Visual observations of heavily-irradiated Tribolium suggested neural and/or neuromuscular damage, as had been previously proposed by others for lethally-irradiated wasps, flies, and mosquitoes. Results of experiments using fractionated high doses supported the suggestion that the hyperacute or high-dose mode of death is the result of damage to nonproliferative tissues. Relative resistance of a strain to the hyperacute or high-dose mode of death was not correlated with resistance to the midlethal mode, which is believed to be the result of damage to the proliferative cells of the midgut. Using the high-dose mode of death as a model of radiation damage to nonproliferative tissues, the effects of age, and of a moderate priming dose were assessed. Beetles showed age-related increase in sensitivity to the high-dose mode of death, suggesting a decline in capacity to repair radiation damage to postmitotic tissue. This correlated with a decrease (50%) in the amount of repair reflected in the sparing effect of dose-fractionation (SDF) between the age of 1 to 3 months. The age related increase in radiosensitivity was reduced by a moderate priming dose (40 or 65 Gy) given at a young age

  14. Toxicity status and anti-ulcerative potential of Sanseviera trifasciata leaf extract in wistar rats

    Directory of Open Access Journals (Sweden)

    Osaseaga Macdonald Ighodaro

    2017-06-01

    Full Text Available Aims: The lethal dose (LD50 and anti-ulcerative potentials of Sansevieria trifasciata (ST leaf extract were investigated. Methods: LD50 was determined through two routes of administration (intraperitoneal and oral using the method of Lorke. The anti-ulcerative activity was evaluated in indomethacin-induced ulcer model (40 mg/kg BW, i.p, single dose against a reference drug, Cimetidine (100 mg/kg BW, per ox (p.o. ST was assessed at two different doses (200 and 400 mg/kg BW, p.o. Treatments were done twice daily at 8 h interval for 7 days prior to indomethacin injection. Results: The intraperitoneal (i.p LD50 was determined as 774.60 mg/kg BW and oral administration of the extract at 18,000 mg/kg BW dosage did not cause any negative behavioral changes in the animals, and no mortality was recorded after 24h of the experiment. ST- pre-treated animals showed some improvement against indomethacin-induced ulceration. The extract was able to an extent prevent indomethacin-induced reduction in gastric volume (36.1 %, free acidity (55.3 %, total acidity (35.6 % while minimizing increase in pH by (13.3 %. Moreover, the extract showed 17.92% and 14.96 % ulcer-protective ability at 200 and 400 mg/kg BW respectively. The phytochemical analysis of ST extract revealed the presence of phytoconstituents such as glycosides, saponins, flavonoids, terpenoids, alkaloids, tannins, Anthraquinone and glycosides. Conclusions: Sansevieria trifasciata apparently has a promising anti-ulcerative potential, and is safe for use in folk medicine. This valuable medicinal property is probably due to the array of important phytochemicals contained in the plant as observed in this study. However, further study involving bioassay-guided identification of the main anti-ulcerative compound in ST is required to establish the use of the plant as a viable anti-ulcerative agent. [J Complement Med Res 2017; 6(2.000: 234-239

  15. Histopathological effects of lethal and sub-lethal concentrations of ...

    African Journals Online (AJOL)

    The histopathological effects of lethal and sub-lethal concentrations of glyphosate on African catfish Clarias gariepinus were investigated. C. gariepinus juveniles were assessed in a static renewal bioassay for 96 hours (acute toxicity) and 28 days (chronic toxicity) using varying concentrations (0.0 mg/l 20.0 mg/l, 30.0 mg/l, ...

  16. Dominant lethal effect of gamma radiation of 60Co in Biomphalaria glabrata (SAY, 1818)

    International Nuclear Information System (INIS)

    Tallarico, Lenita de Freitas

    2003-01-01

    Germ cell mutations are used in ecotoxicological studies as biomarkers of population effects and indicators of ecological changes. Biomphalaria glabrata, a freshwater mollusk, is a good experimental model for biomonitoring studies due to its biological characteristics and the ecological importance of this invertebrate group. The dominant lethal test was established in B. glabrata for the detection of germ cell mutations. Results with chemical mutagens showed that this system is efficient, specific and sensitive in the evaluation of germ cell mutations induced by reference mutagens. In this work, the dominant lethal effects of gamma radiation of 60 Co were studied. A preliminary experiment was done to establish the dose range and to estimate the chronology of spermatogenesis in B. glabrata. This estimate is possible because of the uniformity in response to ionizing radiation between germ cells at homologous stages of spermatogenesis in widely different species. In general, pre-meiotic germ cells are less sensitive to the induction of lethal dominant mutations than post-meiotic cells. This effect can be attributed to: young gametogenic cells - mitotically active - have greater repair ability from sub-lethal DNA damage and there is a selective elimination of the damaged cells. In our system: induction of lethal dominant mutations causes an increase in the frequency of malformations and, cytotoxic effect is displayed as a reduction in the crossing rates. Total duration of spermatogenesis was estimated in approximately 36 days, with the following distribution of stages: 1 to 13 days - spermatogonia, 14 to 20 days - spermatocytes, 21 to 36 days - spermatids and spermatozoa. Based on this chronology, irradiated wild-type snails with 2,5; 10 and 20Gy and crossed with non-irradiated albino snails after 7, 17, 23, 30 and 36 days. The frequencies of malformations in the heterozygous wild-type offspring of the nonirradiated albino snails were used as indicator of germ cell

  17. Acute and sub-lethal exposure to copper oxide nanoparticles causes oxidative stress and teratogenicity in zebrafish embryos.

    Science.gov (United States)

    Ganesan, Santhanamari; Anaimalai Thirumurthi, Naveenkumar; Raghunath, Azhwar; Vijayakumar, Savitha; Perumal, Ekambaram

    2016-04-01

    Nano-copper oxides are a versatile inorganic material. As a result of their versatility, the immense applications and usage end up in the environment causing a concern for the lifespan of various beings. The ambiguities surround globally on the toxic effects of copper oxide nanoparticles (CuO-NPs). Hence, the present study endeavored to study the sub-lethal acute exposure effects on the developing zebrafish embryos. The 48 hpf LC50 value was about 64 ppm. Therefore, we have chosen the sub-lethal dose of 40 and 60 ppm for the study. Accumulation of CuO-NPs was evidenced from the SEM-EDS and AAS analyzes. The alterations in the AChE and Na(+)/K(+)-ATPase activities disrupted the development process. An increment in the levels of oxidants with a concomitant decrease in the antioxidant enzymes confirmed the induction of oxidative stress. Oxidative stress triggered apoptosis in the exposed embryos. Developmental anomalies were observed with CuO-NPs exposure in addition to oxidative stress in the developing embryos. Decreased heart rate and hatching delay hindered the normal developmental processes. Our work has offered valuable data on the connection between oxidative stress and teratogenicity leading to lethality caused by CuO-NPs. A further molecular mechanism unraveling the uncharted connection between oxidative stress and teratogenicity will aid in the safe use of CuO-NPs. Copyright © 2015 John Wiley & Sons, Ltd.

  18. A preliminary study on doses of 60Co-γ ray for mutation breeding of Roegneria

    International Nuclear Information System (INIS)

    Jiang Yun; Lin Yang; Xuan Pu; Luo Xiaomei; Zhang Haiqin

    2011-01-01

    Six groups from three species of Roegneria were radiated with eight ladders of 60 Co-γ ray for finding the most suitable absorbed dose. The dose ladders were CK (0 Gy), 50 Gy, 100 Gy, 150 Gy, 200 Gy, 250 Gy, 300 Gy and 400 Gy. The half-lethal dose of six gourps, generated by multi-Target Single Hit Model Equation, were from 59.6 Gy to 172.8 Gy. Germination percentage of seeds, height of seeding, plant survival percentage and setting percentage were investigated. The most suitable absorbed doses of each species primerly were deduced from these data. The research provide a valuable reference for Roegneria mutation breeding on chousing the absorbed does. (authors)

  19. Semi-lethal high temperature and heat tolerance of eight Camellia species

    OpenAIRE

    He, XY; Ye, H; Ma, JL; Zhang, RQ; Chen, GC; Xia, YY

    2012-01-01

    Annual leaf segments of eight Camellia species were used to study the heat tolerance by an electrical conductivity method, in combination with a Logistic equation to ascertain the semi-lethal high temperature by fitting the cell injury rate curve. Te relationship between the processing temperature and the cell injury rate in Camellia showed a typical "S" shaped curve, following the Logistic model. Te correlation coeficient was above 0.95. Te semi-lethal high temperature LT50 of the eight Came...

  20. Venomics, lethality and neutralization of Naja kaouthia (monocled cobra) venoms from three different geographical regions of Southeast Asia.

    Science.gov (United States)

    Tan, Kae Yi; Tan, Choo Hock; Fung, Shin Yee; Tan, Nget Hong

    2015-04-29

    Previous studies showed that venoms of the monocled cobra, Naja kaouthia from Thailand and Malaysia are substantially different in their median lethal doses. The intraspecific venom variations of N. kaouthia, however, have not been fully elucidated. Here we investigated the venom proteomes of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V) through reverse-phase HPLC, SDS-PAGE and tandem mass spectrometry. The venom proteins comprise 13 toxin families, with three-finger toxins being the most abundant (63-77%) and the most varied (11-18 isoforms) among the three populations. NK-T has the highest content of neurotoxins (50%, predominantly long neurotoxins), followed by NK-V (29%, predominantly weak neurotoxins and some short neurotoxins), while NK-M has the least (18%, some weak neurotoxins but less short and long neurotoxins). On the other hand, cytotoxins constitute the main bulk of toxins in NK-M and NK-V venoms (up to 45% each), but less in NK-T venom (27%). The three venoms show different lethal potencies that generally reflect the proteomic findings. Despite the proteomic variations, the use of Thai monovalent and Neuro polyvalent antivenoms for N. kaouthia envenomation in the three regions is appropriate as the different venoms were neutralized by the antivenoms albeit at different degrees of effectiveness. Biogeographical variations were observed in the venom proteome of monocled cobra (Naja kaouthia) from Malaysia, Thailand and Vietnam. The Thai N. kaouthia venom is particularly rich in long neurotoxins, while the Malaysian and Vietnamese specimens were predominated with cytotoxins. The differentially expressed toxin profile accounts for the discrepancy in the lethal dose of the venom from different populations. Commercially available Thai antivenoms (monovalent and polyvalent) were able to neutralize the three venoms at different effective doses, hence supporting their uses in the three regions. While dose adjustment according to

  1. Evidence for Radiation-Induced Disseminated Intravascular Coagulation as a Major Cause of Radiation-Induced Death in Ferrets

    Energy Technology Data Exchange (ETDEWEB)

    Krigsfeld, Gabriel S.; Savage, Alexandria R.; Billings, Paul C.; Lin, Liyong; Kennedy, Ann R., E-mail: akennedy@mail.med.upenn.edu

    2014-03-15

    Purpose: The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Methods and Materials: Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. Results: The lethal dose of radiation to 50% of the population (LD{sub 50}) of the ferrets was established at ∼1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Conclusions: Data presented here provide evidence that death at the LD{sub 50} in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals.

  2. Immunomodulatory Properties and Molecular Effects in Inflammatory Diseases of Low-Dose X-Irradiation

    International Nuclear Information System (INIS)

    Rödel, Franz; Frey, Benjamin; Manda, Katrin; Hildebrandt, Guido; Hehlgans, Stephanie; Keilholz, Ludwig; Seegenschmiedt, M. Heinrich; Gaipl, Udo S.; Rödel, Claus

    2012-01-01

    Inflammatory diseases are the result of complex and pathologically unbalanced multicellular interactions. For decades, low-dose X-irradiation therapy (LD-RT) has been clinically documented to exert an anti-inflammatory effect on benign diseases and chronic degenerative disorders. By contrast, experimental studies to confirm the effectiveness and to reveal underlying cellular and molecular mechanisms are still at their early stages. During the last decade, however, the modulation of a multitude of immunological processes by LD-RT has been explored in vitro and in vivo. These include leukocyte/endothelial cell adhesion, adhesion molecule and cytokine/chemokine expression, apoptosis induction, and mononuclear/polymorphonuclear cell metabolism and activity. Interestingly, these mechanisms display comparable dose dependences and dose-effect relationships with a maximum effect in the range between 0.3 and 0.7 Gy, already empirically identified to be most effective in the clinical routine. This review summarizes data and models exploring the mechanisms underlying the immunomodulatory properties of LD-RT that may serve as a prerequisite for further systematic analyses to optimize low-dose irradiation procedures in future clinical practice.

  3. Immunomodulatory Properties and Molecular Effects in Inflammatory Diseases of Low-Dose X-Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rödel, Franz [Department of Radiotherapy and Oncology, University Hospital of Frankfurt, Johann Wolfgang-Goethe Universität, Frankfurt am Main (Germany); Frey, Benjamin [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen (Germany); Manda, Katrin; Hildebrandt, Guido [Department of Radiotherapy and Radiation Oncology, University of Rostock, Rostock (Germany); Hehlgans, Stephanie [Department of Radiotherapy and Oncology, University Hospital of Frankfurt, Johann Wolfgang-Goethe Universität, Frankfurt am Main (Germany); Keilholz, Ludwig [Department of Radiotherapy, Clinical Center Bayreuth, Bayreuth (Germany); Seegenschmiedt, M. Heinrich [Strahlenzentrum Hamburg Medizinisches Versorgungszentrum, Hamburg (Germany); Gaipl, Udo S. [Department of Radiation Oncology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen (Germany); Rödel, Claus, E-mail: franz.roedel@kgu.de [Department of Radiotherapy and Oncology, University Hospital of Frankfurt, Johann Wolfgang-Goethe Universität, Frankfurt am Main (Germany)

    2012-09-25

    Inflammatory diseases are the result of complex and pathologically unbalanced multicellular interactions. For decades, low-dose X-irradiation therapy (LD-RT) has been clinically documented to exert an anti-inflammatory effect on benign diseases and chronic degenerative disorders. By contrast, experimental studies to confirm the effectiveness and to reveal underlying cellular and molecular mechanisms are still at their early stages. During the last decade, however, the modulation of a multitude of immunological processes by LD-RT has been explored in vitro and in vivo. These include leukocyte/endothelial cell adhesion, adhesion molecule and cytokine/chemokine expression, apoptosis induction, and mononuclear/polymorphonuclear cell metabolism and activity. Interestingly, these mechanisms display comparable dose dependences and dose-effect relationships with a maximum effect in the range between 0.3 and 0.7 Gy, already empirically identified to be most effective in the clinical routine. This review summarizes data and models exploring the mechanisms underlying the immunomodulatory properties of LD-RT that may serve as a prerequisite for further systematic analyses to optimize low-dose irradiation procedures in future clinical practice.

  4. Synergistic potential of dillapiole-rich essential oil with synthetic pyrethroid insecticides against fall armyworm

    Directory of Open Access Journals (Sweden)

    Murilo Fazolin

    2016-03-01

    Full Text Available ABSTRACT: The objective of this study was to evaluate the synergy and response homogeneity of the Spodoptera frugiperda larvae population to the Piper aduncum essential oil in combination with pyrethroid insecticides (alpha-cypermethrin, beta-cypermethrin, fenpropathrin, and gamma-cyhalothrin compared to piperonylbutoxide (PBO as positive control. Synergism (SF comparisons were obtained using lethal concentration (LC50 and lethal dose (LD50 ratios of insecticides individually and in their respective synergistic combinations with essential oil and PBO. Dose/concentration-mortality slope curves were used to establish relative toxicity increase promoted by synergism. They also determined homogeneity response. Residual contact revealed significant potentiation for commercial insecticides formulated with beta-cypermethrin (SF=9.05-0.5 and fenpropathrin (SF=34.05-49.77 when combined with the P. aduncum essential oil. For topical contact, significant potentiation occurred only for alpha-cypermethrin (SF=7.55-3.68, fenpropathrin (SF=3.37-1.21, and gamma-cyhalothrin (SF=5.79-10.48 insecticides when combined with essential oil. With the exception of fenpropathrin and gamma-cyhalothrin, insecticides synergistic combinations presented homogeneous response by topical as well as residual contact at least with essential oil. The SF significance values ​​of the P. aduncum essential oil combined with alpha-cypermethrin, beta-cypermethrin, fenpropathrin, and gamma-cyhalothrin insecticides indicated potential for this oil to be used as an alternative to PBO.

  5. Acute, Sub-lethal Cyanide Poisoning in Mice is Ameliorated by Nitrite Alone: Complications Arising from Concomitant Administration of Nitrite and Thiosulfate as an Antidotal Combination

    Science.gov (United States)

    Cambal, Leah K.; Swanson, Megan R.; Yuan, Quan; Weitz, Andrew C.; Li, Hui-Hua; Pitt, Bruce R.; Pearce, Linda L.; Peterson, Jim

    2011-01-01

    Sodium nitrite alone is shown to ameliorate sub-lethal cyanide toxicity in mice when given from ~1 hour before until 20 minutes after the toxic dose as demonstrated by the recovery of righting ability. An optimum dose (12 mg/kg) was determined to significantly relieve cyanide toxicity (5.0 mg/kg) when administered to mice intraperitoneally. Nitrite so administered was shown to rapidly produce NO in the bloodsteam as judged by the dose dependent appearance of EPR signals attributable to nitrosylhemoglobin and methemoglobin. It is argued that antagonism of cyanide inhibition of cytochrome c oxidase by NO is the crucial antidotal activity rather than the methemoglobin-forming action of nitrite. Concomitant addition of sodium thiosulfate to nitrite-treated blood resulted in the detection of sulfidomethemoblobin by EPR spectroscopy. Sulfide is a product of thiosulfate hydrolysis and, like cyanide, is known to be a potent inhibitor of cytochrome c oxidase; the effects of the two inhibitors being essentially additive under standard assay conditions, rather than dominated by either one. The findings afford a plausible explanation for an observed detrimental effect in mice associated with the use of the standard nitrite-thiosulfate combination therapy at sub-lethal levels of cyanide intoxication. PMID:21534623

  6. Clinical Symptoms and Histological Changes in Poecilia reticulata following Gamma-Ray Irradiation

    Directory of Open Access Journals (Sweden)

    K. Beňová

    2006-01-01

    Full Text Available Lethality, food intake, clinical symptoms and terminal histological changes were followed after gamma-irradiation with doses of 10, 20, 30, 35 and 40 Gy in guppy, Poecilia reticulata. Clinical symptoms, food intake and longevity were also monitored in the progeny of fish irradiated with a dose of 10 Gy. In the first days after irradiation timidity and lethargy were observed. After doses of 30, 35 and 40 Gy, these symptoms were accompanied with anorexia. The most prominent clinical symptoms observed were emaciation, hampered breathing, exophthalmia and haemorrhages. Histological findings corresponded with these symptoms. In the fish irradiated with 10 or 20 Gy the progeny survived, after a dose of 30 Gy the progeny died within 24 hours after birth and after doses of 35 and 40 Gy dead progeny was born. The survival data provide an estimate of LD50/30 equal to 29 Gy. Higher relative mortality and more severe clinical symptoms were observed in females. The progeny of irradiated parent fish grew and survived for 3 months maximum.

  7. Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

    Science.gov (United States)

    Tooming, Ene; Merivee, Enno; Must, Anne; Sibul, Ivar; Williams, Ingrid

    2014-06-01

    Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear. Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L(-1) caused initial short-term (24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates. Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75,000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field. © 2013 Society of Chemical Industry.

  8. Fabrication of LD-3 Polymer Directional Couplers

    National Research Council Canada - National Science Library

    Chen, Ray T

    1998-01-01

    .... LD-3 polymer directional couplers arc designed and fabricated to operate at 1.3 microns. Waveguide propagation losses, device characterization, demonstration of cross coupling and packaged device pictures are presented in this final report.

  9. Effect of sublethal levels of ionizing radiation on a predator-prey interaction

    International Nuclear Information System (INIS)

    Chee, P.C.

    1976-01-01

    The predator-prey interaction studied was that between the largemouth bass (Micropterus salmoides) and the fathead minnow (Pimephales promelas) in an artificial test environment. Experiments were first conducted to determine the 50% lethal dose at 30 days of the minnow. Three different dose rates were used to test the effect of dose rate on the 50% lethal dose value. After the 50% lethal dose was determined the predator-prey interaction experiment was conducted using 30% of the 50% lethal dose as the highest radiation dose, this dose being considered the upper limit to sublethal radiation levels. A 4 x 4 Latin square design was chosen for the experiment, with four treatment levels (control plus three radiation levels) and four replicates. In each test 10 prey minnow were offered to one predator bass and the number of prey left after 14 days was the parameter of interest. A predator-prey interaction experiment using a single high level of radiation and two types of controls as conducted to ascertain the ability of the test environment to detect changes in the predator-prey interaction. The two types of controls were irradiated prey not exposed to predation and non-irradiated prey exposed to predation. An experiment was also conducted to test the correlation between the physical activity patterns of minnow and different doses of radiation. At a dose rate of 37.8 rad/min the 50% lethal dose at 30 days for minnow was found to be 2650 rad. It was found that dose rate had a strong influence on the 50% lethal dose. In the predator-prey interaction test it was found that the 14-day survival rate of prey was unaffected by sublethal levels of ionizing radiation. No significant correlation was detected between the physical activity patterns of minnow and radiation dose

  10. Influence of paternal 252Cf neutron exposure on abnormal sperm, embryonal lethality, and liver tumorigenesis in the F1 offspring of mice

    International Nuclear Information System (INIS)

    Watanabe, Hiromitsu; Takahashi, Tadateru; Lee, Juing-Yi

    1996-01-01

    Experiments were conducted to determine whether neutron-induced genetic damage in parental germline cells can lead to the development of cancer in the offspring. Seven-week-old C3H male mice were irradiated with 252 Cf neutrons at a dose of 0, 50, 100, or 200 cGy. Two weeks or 3 months after irradiation, the male mice were mated with virgin 9-week-old C57BL females. Two weeks after irradiation, the irradiated male mice showed an increased incidence of sperm abnormalities, which led to embryo lethalities in a dose-dependent manner when they were mated with unirradiated female mice. Furthermore, liver tumors in male offspring of male mice in the 50 cGy group were significantly increased in 19 of 44 (43.2%) animals, in clear contrast to the unirradiated group (1 of 31; 3.2%) (P 1 generation may be caused by genetic transmission of hepatoma-associated trait (s) induced by 252 Cf neutron irradiation. (author)

  11. Low Dose Sarin Leads To Murine Cardiac Dysfunction

    Science.gov (United States)

    2010-03-01

    hypoxia resulting from bronco -constriction also affects the cardiovascular system by reinforcing sympathetic tone, while ACh induced epinephrine...3000 4000 5000 6000 7000 8000 Septum LV Wall Total LV Ca rd io m yo cy te Si ze (P ix el s/ nu cl ei ) Control 0.4 LD50 0.5 LD50 * pɘ.05 vs... el s/ nu cl ei ) Control Sarin (Combined Groups) * pɘ.05 vs. control ** pɘ.01 vs. control † pɘ.001 vs. control 59 Results of Collagen

  12. Anticonvulsant properties of the total alkaloid fraction of Rauvolfia ligustrina Roem. et Schult. in male mice

    Directory of Open Access Journals (Sweden)

    Lucindo J. Quintans-Júnior

    Full Text Available Rauvolfia ligustrina Roem et. Schult (Apocynaceae, commonly known as "paratudo" and "arrebenta-boi" is a small tree found in Brazilian Northeastern. Previous studies have demonstrated depressant and anticonvulsant properties of the ethanol extract of Rauvolfia ligustrina. The aim of the present study was the determination of the lethal dose 50% (LD50 and the effects of total alkaloid fraction (TAF of the aerial parts of R. ligustrina in animal models of convulsion. It was found that the acute toxicity of TAF was 127.8 (112.5-145.2 mg/kg (i.p. in mice. TAF (20 mg/kg, ip significantly increased (p < 0.05 the latencies of clonic seizures induced by pentylenetetrazol (PTZ and picrotoxin (PIC. However, TAF did not protect the animals in maximal electroshock (MES induced seizures. These results suggest that TAF of R. ligustrina possesses anticonvulsant properties.

  13. Thrombolytic effects of Douchi Fibrinolytic enzyme from Bacillus subtilis LD-8547 in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Yuan Jun

    2012-07-01

    Full Text Available Abstract Background Today, thrombosis is one of the most widely occurring diseases in modern life. Drugs with thrombolytic functions are the most effective methods in the treatment of thrombosis. Among them, Douchi fibrinolytic enzyme (DFE is a promising agent. DFE was isolated from Douchi, a typical and popular soybean-fermented food in China, and it can dissolve fibrin directly and efficiently. A strain, Bacillus subtilis LD-8547 produced DFE with high fibrinolytic activity has been isolated in our lab previously. Results In the study, thrombolytic effect of DFE from Bacillus subtilis LD-8547 was studied in vitro and in vivo systematically. The results showed that DFE played a significant role in thrombolysis and anticoagulation in vitro. And the thrombolytic effects correlated with DFE in a dose-dependent manner. In vivo, the acute toxicity assay showed that DFE had no obvious acute toxicity to mice. Test of carrageenan-induced thrombosis in mice indicated that the DFE significantly prevented tail thrombosis, and arterial thrombosis model test indicated that Douchi fibrinolytic enzyme DFE had thrombolytic effect on carotid thrombosis of rabbits in vivo. Other results in vivo indicated that DFE could increase bleeding and clotting time obviously. Conclusions The DFE isolated from Bacillus subtilis LD-8547 has obvious thrombolytic effects in vitro and in vivo. This function demonstrates that this enzyme can be a useful tool for preventing and treating clinical thrombus.

  14. Proteome-level assessment of origin, prevalence and function of Leucine-Aspartic Acid (LD) motifs

    KAUST Repository

    Alam, Tanvir

    2018-03-11

    Short Linear Motifs (SLiMs) contribute to almost every cellular function by connecting appropriate protein partners. Accurate prediction of SLiMs is difficult due to their shortness and sequence degeneracy. Leucine-aspartic acid (LD) motifs are SLiMs that link paxillin family proteins to factors controlling (cancer) cell adhesion, motility and survival. The existence and importance of LD motifs beyond the paxillin family is poorly understood. To enable a proteome-wide assessment of these motifs, we developed an active-learning based framework that iteratively integrates computational predictions with experimental validation. Our analysis of the human proteome identified a dozen proteins that contain LD motifs, all being involved in cell adhesion and migration, and revealed a new type of inverse LD motif consensus. Our evolutionary analysis suggested that LD motif signalling originated in the common unicellular ancestor of opisthokonts and amoebozoa by co-opting nuclear export sequences. Inter-species comparison revealed a conserved LD signalling core, and reveals the emergence of species-specific adaptive connections, while maintaining a strong functional focus of the LD motif interactome. Collectively, our data elucidate the mechanisms underlying the origin and adaptation of an ancestral SLiM.

  15. Protective immunity against tularemia provided by an adenovirus-vectored vaccine expressing Tul4 of Francisella tularensis.

    Science.gov (United States)

    Kaur, Ravinder; Chen, Shan; Arévalo, Maria T; Xu, Qingfu; Chen, Yanping; Zeng, Mingtao

    2012-03-01

    Francisella tularensis, a category A bioterrorism agent, is a highly infectious organism that is passed on via skin contact and inhalation routes. A live attenuated vaccine strain (LVS) has been developed, but it has not been licensed for public use by the FDA due to safety concerns. Thus, there exists a need for a safer and improved vaccine. In this study, we have constructed a replication-incompetent adenovirus, Ad/opt-Tul4, carrying a codon-optimized gene for expression of a membrane protein, Tul4, of F. tularensis LVS. Its ability to protect against lethal challenge and its immunogenicity were evaluated in a murine model. An intramuscular injection of a single dose (1 × 10(7) PFU) of Ad/opt-Tul4 elicited a robust Tul4-specific antibody response. Assays suggest a Th1-driven response. A single dose elicited 20% protection against challenge with 100 × 50% lethal dose (LD(50)) F. tularensis LVS; two additional booster shots resulted in 60% protection. In comparison, three doses of 5 μg recombinant Tul4 protein did not elicit significant protection against challenge. Therefore, the Ad/opt-Tul4 vaccine was more effective than the protein vaccine, and protection was dose dependent. Compared to LVS, the protection rate is lower, but an adenovirus-vectored vaccine may be more attractive due to its enhanced safety profile and mucosal route of delivery. Furthermore, simple genetic modification of the vaccine may potentially produce antibodies protective against a fully virulent strain of F. tularensis. Our data support the development and further research of an adenovirus-vectored vaccine against Tul4 of F. tularensis LVS.

  16. Mosquitocidal Activity and Mode of Action of the Isoxazoline Fluralaner.

    Science.gov (United States)

    Jiang, Shiyao; Tsikolia, Maia; Bernier, Ulrich R; Bloomquist, Jeffrey R

    2017-02-06

    Mosquitoes, such as Aedes aegypti and Anopheles gambiae , are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC 50 (lethal concentration for 50% mortality) values of 1.8 ppb and 0.4 ppb, respectively. Following topical application to adult Ae. aegypti , fluralaner toxicity reached a plateau in about 3 days, with 1- and 3-day LD 50 (lethal dose for 50% mortality) values of 1.3 ng/mg and 0.26 ng/mg, suggesting a slowly developing toxicity. Fipronil outperformed fluralaner by up to 100-fold in adult topical, glass contact, and feeding assays on Ae. aegypti . These data show that fluralaner does not have exceptional toxicity to mosquitoes in typical exposure paradigms. In electrophysiological recordings on Drosophila melanogaster larval central nervous system, the effectiveness of fluralaner for restoring nerve firing after gamma-aminobutyric acid (GABA) treatment, a measure of GABA antagonism, was similar in susceptible Oregon-R and cyclodiene-resistant rdl -1675 strains, with EC 50 (half maximal effective concentration) values of 0.34 µM and 0.29 µM. Although this finding suggests low cross resistance in the presence of rdl , the moderate potency, low contact activity, and slow action of fluralaner argue against its use as an adult mosquitocide for vector control.

  17. Application of a Pelletron accelerator to study total dose radiation effects on 50 GHz SiGe HBTs

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, K.C.; Pushpa, N.; Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Tripathi, Ambuj [Inter University Accelerator Centre (IUAC), New Delhi 110 067 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Total dose effects of 50 MeV Li3+ ion on 50 GHz SiGe HBTs is investigated. Black-Right-Pointing-Pointer Ion irradiated results were compared with Co-60 gamma results. Black-Right-Pointing-Pointer 50 MeV Li ions create more damage in E-B spacer oxide when compared to Co-60 gamma radiation. Black-Right-Pointing-Pointer Co-60 gamma radiation create more damage in STI oxide when compared to 50 MeV Li ions. Black-Right-Pointing-Pointer Worst case total dose radiation effects can be studied using Pelletron accelerator facilities. - Abstract: We have investigated the effects of 50 MeV lithium ion irradiation on the DC electrical characteristics of first-generation silicon-germanium heterojunction bipolar transistors (50 GHz SiGe HBTs) in the dose range of 600 krad to 100 Mrad. The results of 50 MeV Li{sup 3+} ion irradiation on the SiGe HBTs are compared with 63 MeV proton and Co-60 gamma irradiation results in the same dose range in order to understand the damage induced by different LET species. The radiation response of emitter-base (EB) spacer oxide and shallow trench isolation (STI) oxide to different irradiation types are discussed in this paper. We have also focused on the efficacy in the application of a Pelletron accelerator to study total dose irradiation studies in SiGe HBTs.

  18. Comparison of Lethal Concentrations (LC50-96 H of Cdcl2, Crcl3, and Pb (NO32 in Common Carp (Cyprinus carpio and Sutchi Catfish (Pangasius Hypophthalmus

    Directory of Open Access Journals (Sweden)

    Zeynab Abedi

    2012-11-01

    Full Text Available Background: The present study compared lethal concentrations (LC50-96 h of CdCl2, CrCl3, and Pb (NO32 between two scaled and scaleless freshwater fish species: Cyprinus carpio (Cyprinidae and Pangasius hypophthalmus (Pangasiidae. Methods: The experimental fishes were obtained from fish markets/ponds with average lengths and weights of approximately 11.68 ±1.92 and 9.8±1.9 cm, and 25.92±6.3 and 18.61±3.22 g for C. carpio and P. hypophthalmus, respectively. The fishes were exposed to different concentrations of cadmium (Cd (0, 10, 20, 40, 80, 100, 120, 200 mg L−1 lead (Pb (0, 20, 40, 50, 60, 90, 150 mg L−1, and chromium (Cr (0, 5, 10, 20, 30, 40 mg L−1 for 96 h. Physicochemical parameters, such as dissolved oxygen, pH, and temperature of aquaria as well as mortality rate of the fishes, were monitored daily. Results: The 50% lethal concentrations (LC50-96 h of CdCl2, CrCl3, and Pb (NO32 for P. hypophthalmus were found at 64.89, 7.46, and 48.06 mg L−1, and those of CdCl 2, CrCl 3, Pb (NO32 for C. carpio were detected at 84.8, 17.05, and 77.33 mg L−1. The ratios of heavy metal toxicity factors (TF were greater for common carp compared to those for the catfish. Conclusion: Our preliminary findings suggest that common carp C. carpio with higher LC50 (and LC100 values appears to be more tolerant to heavy metals exposure than the catfish (P. hypophthalmus. This may be due to the resistance to the heavy metals through protection from the carp's scaled body versus scaleless body of the catfish.

  19. Azadirachtin effects on mating success, gametic abnormalities and progeny survival in Drosophila melanogaster (Diptera).

    Science.gov (United States)

    Oulhaci, Chemseddine M; Denis, Béatrice; Kilani-Morakchi, Samira; Sandoz, Jean-Christophe; Kaiser, Laure; Joly, Dominique; Aribi, Nadia

    2018-01-01

    Azadirachtin is a prominent natural pesticide and represents an alternative to conventional insecticides. It has been successfully used against insect pests. However, its effects on reproduction require further analysis. Here we investigated lethal and sublethal effects of azadirachtin, on treated adults in a model insect, Drosophila melanogaster (Meigen). Dose-mortality relationships as well as several parameters of reproduction (mating, spermatogenesis, oogenesis and fertility) were examined. Neem-Azal, a commercial formulation of azadirachtin, applied topically on newly emerged adults, increased mortality with a positive dose-dependent relationship. The LD 50 (0.63 μg) was determined 24 h after treatment using a non-linear regression. Adults surviving this dose had a mating success that was divided by 3 and a progeny production reduced by half when males were treated, and even more when females were treated. When combining probability of survival, of mating and reduced progeny, it appeared that LD 50 induced a 98% reduction in reproductive rates. Reduced progeny was partially explained by the effect of adult treatment on gametes number and abnormalities. The number of cysts and the apical nuclei positions within the cysts decreased by 29.7% and 20%, respectively, in males. In females, the number of oocytes per ovary and the volume of basal oocytes also decreased by 16.1% and 32.4%, respectively. Azadirachtin causes significant toxic effects in both sexes and decreases the fecundity and fertility of D. melanogaster. Females are more sensitive to azadirachtin. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  20. Measurement of oxygen enhancement ratio for sub-lethal region using saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Nairy, Rajesha K.; Anjaria, K.B.; Bhat, Nagesh N.; Chaurasia, Rajesh K.; Balakrishnan, Sreedevi; Yerol, Narayana

    2013-01-01

    Oxygen is one of the best known modifiers of radiation sensitivity and the biological effects is greater in the presence of oxygen, and significant modifying effect will be observed only for low LET radiations. The reduced oxygen availability is sensed which trigger homeostatic responses, which impact on virtually all areas of biology and medicine. Failure to achieve complete response following radiotherapy of large tumors is attributed to the presence of radio-resistant hypoxic cells, therefore clarifying the mechanism of the oxygen effect is important. In the present study, a mutant type diploid yeast strain, Saccharomyces cerevisiae D7 was used to study Oxygen Enhancement Ratio (OER) using 60 Co gamma radiation. Cells were washed thrice by centrifugation (2000 g for 5 min) and re-suspended to a cell concentration of 1x108 cells mL-1 in a sterile polypropylene vial for irradiation (sub-lethal dose range, 0-100 Gy). Hypoxic conditions were achieved by incubating the cells in airtight vials at 30℃ for 30 min prior to irradiation. The gene conversion and back mutation analysis were carried out according to the standard protocol. Gene conversion is the radio-sensitive biological endpoint, that can be studied in Saccharomyces cerevisiae D7 yeast cells at trp locus in tryptophan (Trp- medium) deficient medium. The dose response relation at euoxic and hypoxic condition in sub-lethal doses are found to be linear and is represented by Y (Euoxic) = (6.54±0.102) D with R2=0.999 and for hypoxic condition Y(Hypoxic) = (3.346±0.033) D with R2=0.996. The OER can be calculated by dividing the euoxic slope with hypoxic slope, and is 1.95. Back mutation, which is a result of reversion of Isoleucine auxotrophs to prototrophs gives very good information at sub-lethal doses. The dose response relation between back mutated cells and radiation doses at Euoxic and hypoxic condition can be represented as Y(Euoxic) = (2.85±0.126) D with R2= 0.976 and for hypoxic condition Y

  1. Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae.

    Science.gov (United States)

    Toyoshima, Yoshiyuki; Takahashi, Akemi; Tanaka, Hisaki; Watanabe, Jun; Mogi, Yoshinobu; Yamazaki, Tatsuo; Hamada, Ryoko; Iwashita, Kazuhiro; Satoh, Katsuya; Narumi, Issay

    2012-12-01

    Aspergillus oryzae is a fungus that is used widely in traditional Japanese fermentation industries. In this study, the lethal and mutagenic effects of different linear energy transfer (LET) radiation in freeze-dried conidia of A. oryzae were investigated. The lethal effect, which was evaluated by a 90% lethal dose, was dependent on the LET value of the ionizing radiation. The most lethal ionizing radiation among that tested was (12)C(5+) ion beams with an LET of 121keV/μm. The (12)C(5+) ion beams had a 3.6-times higher lethal effect than low-LET (0.2keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. (12)C(6+) ion beams with an LET of 86keV/μm were the most effective in inducing selenate resistance. The mutant frequency following exposure to (12)C(6+) ion beams increased with an increase in dose and reached 3.47×10(-3) at 700Gy. In the dose range from 0 to 700Gy, (12)C(5+) ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67×10(-3)) at 400Gy. To elucidate the characteristics of mutation induced by ionizing radiation, mutations in the sulphate permease gene (sB) and ATP sulfurylase gene (sC) loci, the loss of function of which results in a selenate resistant phenotype, were compared between (12)C(5+) ion beams and γ-rays. We detected all types of transversions and transitions. For frameshifts, the frequency of a +1 frameshift was the highest in all cases. Although the incidence of deletions >2bp was generally low, deletions >20bp were characteristic for (12)C(5+) ion beams. γ-rays had a tendency to generate mutants carrying a multitude of mutations in the same locus. Both forms of radiation also induced genome-wide large-scale mutations including chromosome rearrangements and large deletions. These results provide new basic insights into the mutation breeding of A. oryzae using ionizing radiation. Crown Copyright © 2012. Published

  2. X-ray induced dominant lethal mutations in mature and immature oocytes of guinea-pigs and golden hamsters

    International Nuclear Information System (INIS)

    Cox, B.D.; Lyon, M.F.

    1975-01-01

    The induction of dominant lethal mutations by doses of 100-400 rad X-rays in oocytes of the guinea-pig and golden hamster was studied using criteria of embryonic mortality. For both species higher yields were obtained from mature than from immature oocytes. Data on fertility indicated that in the golden hamster immature oocytes were more sensitive to killing by X-rays than mature oocytes but that the converse was true in the guinea-pig. The dose-response relationship for mutation to dominant lethals in pre-ovulatory oocytes of guinea-pigs and golden hamsters was linear, both when based on pre- and post-implantation loss only. The rate per unit dose was higher for the golden hamster, and the old golden hamsters were possibly slightly more sensitive than young ones

  3. Acute contact toxicity test of insecticides (Cipermetrina 25, Lorsban 48E, Thionex 35) on honeybees in the southwestern zone of Uruguay.

    Science.gov (United States)

    Carrasco-Letelier, Leonidas; Mendoza-Spina, Yamandú; Branchiccela, María Belén

    2012-07-01

    Glyphosate-resistant soybean cultivation is expanding rapidly in Uruguay, with its land area having increased by 95 times during the past 10 years. Because of the region's Neotropical conditions, insecticide use is required to ensure adequate soybean productivity. However, in areas shared by soybean crops and beekeepers - such as the southwestern zone of Uruguay (SWZU) - the use of insecticides can increase the risks of honeybee death and honey contamination. Uruguayan commercial and legal guidelines set out practices and field doses designed to prevent acute intoxication with insecticides. However, honeybees in the SWZU are predominantly a polyhybrid subspecies different from that used to set international reference values, and hence they may have a different acute toxicity response, thus rendering such precautions ineffective. The aim of this work was to assess the acute toxicity response of polyhybrid honeybees in the SWZU to cypermethrin (commercial formulation: Cipermetrina 25 Agrin®), chlorpyrifos (commercial formulation: Lorsban 48E®), and endosulfan (commercial formulation: Thionex 35®). Acute toxicity bioassays were conducted to determine the median lethal dose (LD(50)) of each insecticide for the honeybees. The results indicate that, compared with EU reference values, SWZU honeybees have a higher toxicological sensitivity to chlorpyrifos and endosulfan, and a lower toxicological sensitivity to cypermethrin, based on the commercial formulations tested. However, when these results were adjusted according to their field dose equivalents, only chlorpyrifos emerged as a potential problem for beekeeping, as the maximum recommended field dose of Lorsban 48E® for soybean crops in Uruguay is 23 times the corresponding LD(50) for honeybees in the SWZU. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. MO-DE-207A-09: Low-Dose CT Image Reconstruction Via Learning From Different Patient Normal-Dose Images

    Energy Technology Data Exchange (ETDEWEB)

    Han, H; Xing, L [Stanford University, Palo Alto, CA (United States); Liang, Z [Stony Brook University, Stony Brook, NY (United States)

    2016-06-15

    Purpose: To investigate a novel low-dose CT (LdCT) image reconstruction strategy for lung CT imaging in radiation therapy. Methods: The proposed approach consists of four steps: (1) use the traditional filtered back-projection (FBP) method to reconstruct the LdCT image; (2) calculate structure similarity (SSIM) index between the FBP-reconstructed LdCT image and a set of normal-dose CT (NdCT) images, and select the NdCT image with the highest SSIM as the learning source; (3) segment the NdCT source image into lung and outside tissue regions via simple thresholding, and adopt multiple linear regression to learn high-order Markov random field (MRF) pattern for each tissue region in the NdCT source image; (4) segment the FBP-reconstructed LdCT image into lung and outside regions as well, and apply the learnt MRF prior in each tissue region for statistical iterative reconstruction of the LdCT image following the penalized weighted least squares (PWLS) framework. Quantitative evaluation of the reconstructed images was based on the signal-to-noise ratio (SNR), local binary pattern (LBP) and histogram of oriented gradients (HOG) metrics. Results: It was observed that lung and outside tissue regions have different MRF patterns predicted from the NdCT. Visual inspection showed that our method obviously outperformed the traditional FBP method. Comparing with the region-smoothing PWLS method, our method has, in average, 13% increase in SNR, 15% decrease in LBP difference, and 12% decrease in HOG difference from reference standard for all regions of interest, which indicated the superior performance of the proposed method in terms of image resolution and texture preservation. Conclusion: We proposed a novel LdCT image reconstruction method by learning similar image characteristics from a set of NdCT images, and the to-be-learnt NdCT image does not need to be scans from the same subject. This approach is particularly important for enhancing image quality in radiation therapy.

  5. MO-DE-207A-09: Low-Dose CT Image Reconstruction Via Learning From Different Patient Normal-Dose Images

    International Nuclear Information System (INIS)

    Han, H; Xing, L; Liang, Z

    2016-01-01

    Purpose: To investigate a novel low-dose CT (LdCT) image reconstruction strategy for lung CT imaging in radiation therapy. Methods: The proposed approach consists of four steps: (1) use the traditional filtered back-projection (FBP) method to reconstruct the LdCT image; (2) calculate structure similarity (SSIM) index between the FBP-reconstructed LdCT image and a set of normal-dose CT (NdCT) images, and select the NdCT image with the highest SSIM as the learning source; (3) segment the NdCT source image into lung and outside tissue regions via simple thresholding, and adopt multiple linear regression to learn high-order Markov random field (MRF) pattern for each tissue region in the NdCT source image; (4) segment the FBP-reconstructed LdCT image into lung and outside regions as well, and apply the learnt MRF prior in each tissue region for statistical iterative reconstruction of the LdCT image following the penalized weighted least squares (PWLS) framework. Quantitative evaluation of the reconstructed images was based on the signal-to-noise ratio (SNR), local binary pattern (LBP) and histogram of oriented gradients (HOG) metrics. Results: It was observed that lung and outside tissue regions have different MRF patterns predicted from the NdCT. Visual inspection showed that our method obviously outperformed the traditional FBP method. Comparing with the region-smoothing PWLS method, our method has, in average, 13% increase in SNR, 15% decrease in LBP difference, and 12% decrease in HOG difference from reference standard for all regions of interest, which indicated the superior performance of the proposed method in terms of image resolution and texture preservation. Conclusion: We proposed a novel LdCT image reconstruction method by learning similar image characteristics from a set of NdCT images, and the to-be-learnt NdCT image does not need to be scans from the same subject. This approach is particularly important for enhancing image quality in radiation therapy.

  6. New observations on chronic intoxication by very small doses of sodium fluosilicate

    Energy Technology Data Exchange (ETDEWEB)

    Cristiani, H; Chausse, P

    1927-01-01

    It was determined that daily doses of approximately 0.1 of the lethal dose of sodium fluoride produced a fluoric cachexia in guinea pigs which caused the death of the animals in 2 or 3 months. Animals which were given 0.02 of the lethal dose of sodium fluoride were apparently in good health for a period of 10 months. However, after two or three years cachexia was likely to appear.

  7. Lethal/sublethal responses of Daphnia magna to acute norfloxacin contamination and changes in phytoplankton-zooplankton interactions induced by this antibiotic

    Science.gov (United States)

    Pan, Ying; Yan, Shi-Wei; Li, Ruo-Zhu; Hu, Yi-Wen; Chang, Xue-Xiu

    2017-01-01

    Although the well-known antibiotic norfloxacin (NOR) is recognized as an important environmental pollutant, little is known about its impacts on ecological processes, particularly on species interactions. In this paper, we quantified Daphnia magna (Crustacea, Cladocera) responses in mortality rate at lethal NOR concentrations (0, 25, 50, 100, 200, 300 and 400 mg L-1), and in heartbeat rate, swimming behavior and feeding rate (on the green alga Chlorella pyrenoidosa) at sublethal NOR concentrations (0, 25, 50 and 100 mg L-1) to determine the effects of this antibiotic in plankton systems. In 96-h-long lethal experiment, mortality rates of D. magna increased significantly with increasing NOR concentration and exposure time. In sublethal experiments, heartbeat rate decreased, while time ratio of vertical to horizontal swimming (TVH) and the duration of quiescence increased in D. magna individuals exposed to increasing NOR concentrations after 4 and 12 h of exposure. These collectively led to decreases in both average swimming ability and feeding rate, consistent with the positive relationship between average swimming ability and feeding rate. Overall, results indicate that, by affecting zooplankton heartbeat rate and behavior, NOR decreased feeding efficiency of D. magna even at low doses, therefore, it might seriously compromise ecosystem health and function.

  8. Fluence to Effective Dose and Effective Dose Equivalent Conversion Coefficients for Photons from 50 KeV to 10 GeV

    International Nuclear Information System (INIS)

    Ferrari, A.; Pelliccioni, M.; Pillon, M.

    1996-07-01

    Effective dose equivalent and effective dose per unit photon fluence have been calculated by the FLUKA code for various geometrical conditions of irradiation of an anthropomorphic phantom placed in a vacuum. Calculations have been performed for monoenergetic photons of energy ranging from 50 keV to 10 GeV. The agreement with the results of other authors, when existing, is generally very satisfactory

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

    Science.gov (United States)

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

    2017-11-01

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

  10. Theories of Lethal Mutagenesis: From Error Catastrophe to Lethal Defection.

    Science.gov (United States)

    Tejero, Héctor; Montero, Francisco; Nuño, Juan Carlos

    2016-01-01

    RNA viruses get extinct in a process called lethal mutagenesis when subjected to an increase in their mutation rate, for instance, by the action of mutagenic drugs. Several approaches have been proposed to understand this phenomenon. The extinction of RNA viruses by increased mutational pressure was inspired by the concept of the error threshold. The now classic quasispecies model predicts the existence of a limit to the mutation rate beyond which the genetic information of the wild type could not be efficiently transmitted to the next generation. This limit was called the error threshold, and for mutation rates larger than this threshold, the quasispecies was said to enter into error catastrophe. This transition has been assumed to foster the extinction of the whole population. Alternative explanations of lethal mutagenesis have been proposed recently. In the first place, a distinction is made between the error threshold and the extinction threshold, the mutation rate beyond which a population gets extinct. Extinction is explained from the effect the mutation rate has, throughout the mutational load, on the reproductive ability of the whole population. Secondly, lethal defection takes also into account the effect of interactions within mutant spectra, which have been shown to be determinant for the understanding the extinction of RNA virus due to an augmented mutational pressure. Nonetheless, some relevant issues concerning lethal mutagenesis are not completely understood yet, as so survival of the flattest, i.e. the development of resistance to lethal mutagenesis by evolving towards mutationally more robust regions of sequence space, or sublethal mutagenesis, i.e., the increase of the mutation rate below the extinction threshold which may boost the adaptability of RNA virus, increasing their ability to develop resistance to drugs (including mutagens). A better design of antiviral therapies will still require an improvement of our knowledge about lethal

  11. Mechanisms of Enhanced Cell Killing at Low Doses: Implications for Radiation Risk

    International Nuclear Information System (INIS)

    Johnston, Peter J.; Wilson, George D.

    2003-01-01

    We have shown that cell lethality actually measured after exposure to low-doses of low-LET radiation, is markedly enhanced relative to the cell lethality previously expected by extrapolation of the high-dose cell-killing response. Net cancer risk is a balance between cell transformation and cell kill and such enhanced lethality may more than compensate for transformation at low radiation doses over a least the first 10 cGy of low-LET exposure. This would lead to a non-linear, threshold, dose-risk relationship. Therefore our data imply the possibility that the adverse effects of small radiation doses (<10 cGy) could be overestimated in specific cases. It is now important to research the mechanisms underlying the phenomenon of low-dose hypersensitivity to cell killing, in order to determine whether this can be generalized to safely allow an increase in radiation exposure limits. This would have major cost-reduction implications for the whole EM program

  12. An orally available, small-molecule polymerase inhibitor shows efficacy against a lethal morbillivirus infection in a large animal model.

    Science.gov (United States)

    Krumm, Stefanie A; Yan, Dan; Hovingh, Elise S; Evers, Taylor J; Enkirch, Theresa; Reddy, G Prabhakar; Sun, Aiming; Saindane, Manohar T; Arrendale, Richard F; Painter, George; Liotta, Dennis C; Natchus, Michael G; von Messling, Veronika; Plemper, Richard K

    2014-04-16

    Measles virus is a highly infectious morbillivirus responsible for major morbidity and mortality in unvaccinated humans. The related, zoonotic canine distemper virus (CDV) induces morbillivirus disease in ferrets with 100% lethality. We report an orally available, shelf-stable pan-morbillivirus inhibitor that targets the viral RNA polymerase. Prophylactic oral treatment of ferrets infected intranasally with a lethal CDV dose reduced viremia and prolonged survival. Ferrets infected with the same dose of virus that received post-infection treatment at the onset of viremia showed low-grade viral loads, remained asymptomatic, and recovered from infection, whereas control animals succumbed to the disease. Animals that recovered also mounted a robust immune response and were protected against rechallenge with a lethal CDV dose. Drug-resistant viral recombinants were generated and found to be attenuated and transmission-impaired compared to the genetic parent virus. These findings may pioneer a path toward an effective morbillivirus therapy that could aid measles eradication by synergizing with vaccination to close gaps in herd immunity due to vaccine refusal.

  13. Effect of organically bound tritium (OBT) on pre-implantation mouse embryos in vitro

    International Nuclear Information System (INIS)

    Yamada, Takeshi; Ohyama, Harumi

    1989-01-01

    Effect of organically bound tritium (OBT), such as tritiated thymidine and tritium-labeled amino acids, on mouse preimplantation embryos was examined in vitro. Mouse zygotes fertilized in vitro (BC3F 1 eggs x ICR sperm) were cultured in the media containing OBT in various concentrations up to the blastocyst stage. The LD 50 in terms of tritium concentrations in the culture medium were determined by measuring tritium concentrations in the medium to inhibit 50 % of embryos to form blastocyst in vitro. Tritium activities in the embryos were measured at various times during culture of embryos at LD 50 concentration in order to estimate absorbed radiation dose in embryonic cells. The LD 50 values obtained indicate that OBT could inhibit the embryonic development 1000 times more effectively that tritiated water (HTO). However, differences in LD 50 values in terms of absorbed radiation dose between OBT and HTO is not so essential, and might be explained by localized spatial distribution of OBT within the cell. (author)

  14. Effect of dose of gamma-rays and ethylmethane sulphonate on the germination and survival of induced mutations in pigeonpea

    Energy Technology Data Exchange (ETDEWEB)

    Premsekar, S [Central Inst. for Cotton Research, Coimbatore (India). Regional Station; Appadurai, R [Tamil Nadu Agricultural Univ., Coimbatore (India)

    1981-06-01

    The LD/sub 50/ values for germination and survival of the induced mutants (M/sub 1/) of pigeonpea (Cajanus cajan (Linn.) Millsp.) were attained with 20 and 15 krad when gamma-rays were used, and 30 and 40 mM concentration when EMS was used. In the combination treatments the half-kill dose for germination and survival was reached even at the low dose combination of 5 krad gamma-ray + 20 mM EMS. Higher doses resulted in lower pollen and seed fertility. The sterility was much enhanced in the combined treatments. The number of pods, seed yield and weight of seeds could be stimulated with 10 and 15 krad doses of gamma-rays and 20 mM of EMS. In combination treatments such a stimulatory effect was noticed in seed weight only.

  15. Non-contrast CT at comparable dose to an abdominal radiograph in patients with acute renal colic; impact of iterative reconstruction on image quality and diagnostic performance.

    Science.gov (United States)

    McLaughlin, P D; Murphy, K P; Hayes, S A; Carey, K; Sammon, J; Crush, L; O'Neill, F; Normoyle, B; McGarrigle, A M; Barry, J E; Maher, M M

    2014-04-01

    The aim was to assess the performance of low-dose non-contrast CT of the urinary tract (LD-CT) acquired at radiation exposures close to that of abdominal radiography using adaptive statistical iterative reconstruction (ASiR). Thirty-three patients with clinically suspected renal colic were prospectively included. Conventional dose (CD-CT) and LD-CT data sets were contemporaneously acquired. LD-CT images were reconstructed with 40 %, 70 % and 90 % ASiR. Image quality was subjectively and objectively measured. Images were also clinically interpreted. Mean ED was 0.48 ± 0.07 mSv for LD-CT compared with 4.43 ± 3.14 mSv for CD-CT. Increasing the percentage ASiR resulted in a step-wise reduction in mean objective noise (p ASiR LD-CT images had higher diagnostic acceptability and spatial resolution than 90 % ASiR LD-CT images (p ASiR LD-CT with two false positives and 16 false negatives (diameter = 2.3 ± 0.7 mm) equating to a sensitivity and specificity of 72 % and 94 %. Seventy % ASiR LD-CT had a sensitivity and specificity of 87 % and 100 % for detection of calculi >3 mm. Reconstruction of LD-CT images with 70 % ASiR resulted in superior image quality than FBP, 40 % ASIR and 90 % ASIR. LD-CT with ASIR demonstrates high sensitivity and specificity for detection of calculi >3 mm. • Low-dose CT studies for urinary calculus detection were performed with a mean dose of 0.48 ± 0.07 mSv • Low-dose CT with 70 % ASiR detected calculi >3 mm with a sensitivity and specificity of 87 % and 100 % • Reconstruction with 70 % ASiR was superior to filtered back projection, 40 % ASiR and 90 % ASiR images.

  16. On the radiation exposure dose and health management history during 50 years of x-ray working

    International Nuclear Information System (INIS)

    Yoshida, Tomihiro

    1981-01-01

    My X-ray working history has become 50 years at the end of April, 1980. At this chance, the following data were summarized; the case numbers of X-ray photographs (517,132 cases), total amounts of radiation exposure dose (66.85 roentgen) and the results of blood test, which were experienced during past 50 years. The amounts of exposure dose during 35 years till 1965 were measured using my own method, which measured the film blackening as 30 milli-roentgen per week by certain standard method. After 1966 till 1980, the exposure dose were recorded using that of the film-badge service of Nippon Hoan Yohin Kyokai. The total amounts of exposure dose during 50 years were about 1/4 of D = 5 (N - 18). The results of blood test during last 27 years were found to be normal values. Then, it is happy to say that my body has been protected completely, from radiation hazard as a result of taking radiation protection and checking blood test always at my daily radiation works. The data of my own experiences during 50 years are summarized and reported in this paper. (author)

  17. Hypoglycemic Effect of Aqueous and Methanolic Extract of Artemisia afra on Alloxan Induced Diabetic Swiss Albino Mice

    Directory of Open Access Journals (Sweden)

    Idris Ahmed Issa

    2015-01-01

    Full Text Available Diabetes mellitus is metabolic syndrome that causes disability, early death, and many other complications. Currently insulin and many synthetic drugs are used in diabetes treatment. However, these pharmaceutical drugs are too expensive particularly for sub-Saharan population in addition to their undesirable side effects. The present study was aimed to evaluate antidiabetic effect and toxicity level of Artemisia afra which was collected from its natural habitat in Bale Zone, around Goba town, 455 km southeast of Addis Ababa. Air dried aerial parts of Artemisia afra were separately extracted with both distilled water and 95% methanol. Oral acute toxicity test was conducted on healthy Swiss albino mice. Antidiabetic effect of the aqueous and methanolic extracts of Artemisia afra was separately evaluated on alloxan induced diabetic mice at doses of 500, 750, and 1000 mg/Kg body weight orally. The results indicate that mean lethal dose (LD50 for aqueous extract of Artemisia afra was 9833.4 mg/Kg. Blood glucose level was significantly decreased by 24% (p<0.005 and 56.9% (p<0.0004 in groups that received aqueous extract of Artemisia afra at dose of 500 mg/Kg and 750 mg/Kg, respectively. The methanolic extract of Artemisia afra also significantly lowered blood glucose by 49.8% (p<0.0001 at doses of 1000 mg/kg on the 5th hr. Aqueous extract of Artemisia afra was regarded as nontoxic and safe since its LD50 was found above 5000 mg/Kg. Aqueous extract showed higher effect at relatively lower dose as compared to methanolic extract. The aqueous extract was screened positive for phytochemicals like flavonoids, polyphenols, and tannins that were reported to have antioxidant activity.

  18. Rõivatööstuse TOP 50

    Index Scriptorium Estoniae

    2005-01-01

    Rõivatööstuse TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Rõivatööstuse TOP-i firmade üld- ja finantsandmed

  19. Study of interaction of low doses of ionizing radiation with selected pesticides on Artemia franciscana

    Directory of Open Access Journals (Sweden)

    Michaela Špalková

    2015-01-01

    Full Text Available The aim of our study was to observe the effect of low doses of ionizing radiation, azoxystrobin and glyphosate separately as well as in their mutual combinations on the lethality of Artemia franciscana. Increasing intensity of agricultural production leads to continual exposure of animals to pesticide residues. Animals could be exposed to these negative factors in case of possible nuclear accident. A total of 1000 nauplia, randomly placed in 20 groups (1 control and 19 experimental groups, were irradiated with gamma rays (0, 20, 30, 40 or 50 Gy and were kept in solution of standardized sea water and standardized sea water with addition of pesticides (azoxystrobin at a concentration of 0.0001 g·l-1 and glyphosate at a concentration of 0.5 g·l-1 individually or in combination. A significant increase of lethality was observed after 48, 72 and 96 h of exposure to only azoxystrobin, but also in the group exposed to the combined effect of azoxystrobin and glyphosate at all time intervals. On the other hand, a significant decrease of lethality was observed in those groups exposed to ionizing radiation even at the dose of 30 Gy at all time intervals compared to non-irradiated groups. These results confirm the toxicity of azoxystrobin to aquatic organisms; non-toxicity of glyphosate to crustaceans and support the theory of radiation hormesis at the level of 30 Gy radiation dose.

  20. Occurrence of Edwardsiella tarda in wild European eels Anguilla anguilla from Mediterranean Spain.

    Science.gov (United States)

    Alcaide, Elena; Herraiz, Sonia; Esteve, Consuelo

    2006-11-21

    Pure cultures of Edwarsiella tarda were isolated from body ulcers and internal organs of wild European eels caught in a Mediterranean freshwater coastal lagoon (Albufera Lake, Valencia, Spain) over a 1 yr period. Overall, the E. tarda isolation rate from wild eels was 9%, but this increased to 22.8% in diseased individuals. All 22 E. tarda isolates belonged to the 'wild-type' biogroup of the species and were virulent for eels (lethal dose that kills 50% of exposed individuals [LD50 dose]: 10(4.85) to 10(6.83) CFU ind.(-1)), and therefore represented the aetiological agent of the haemorrhagic disease observed in wild European eels. The E. tarda isolates and E. tarda CECT 894T type strain were biochemically and serologically related and resistant to macrolides, antifolates, and glycopeptides, but only the isolates from wild eels were resistant to clindamicyn. This study is the first description of edwardsiellosis in a wild European eel population, and alerts us to the presence of E. tarda in natural wetland environments in Mediterranean Europe.

  1. Antimalarial efficacy of Albizia lebbeck (Leguminosae against Plasmodium falciparum in vitro & P. berghei in vivo

    Directory of Open Access Journals (Sweden)

    Shagun Kalia

    2015-01-01

    Full Text Available Background & objectives: Albizia lebbeck Benth. (Leguminosae has long been used in Indian traditional medicine. The current study was designed to test antimalarial activity of ethanolic bark extract of A. lebbeck (EBEAL. Methods: EBEAL was prepared by soxhlet extraction and subjected to phytochemical analysis. The extract was evaluated for its in vitro antimalarial activity against Plasmodium falciparum chloroquine (CQ sensitive (MRC2 and CQ resistant (RKL9 strains. Cytotoxicity (CC 50 of extract against HeLa cells was evaluated. Median lethal dose (LD 50 was determined to assess safety of EBEAL in BALB/c mice. Schizonticidal (100-1000 mg/kg and preventive (100-750 mg/kg activities of EBEAL were evaluated against P. berghei. Curative activity (100-750 mg/kg of extract was also evaluated. Results: Phytochemical screening revealed presence of alkaloids, flavonoids, phenols, saponins, terpenes and phytosterols. The extract exhibited IC 50 of 8.2 µg/ml (MRC2 and 5.1 µg/ml (RKL9. CC 50 of extract on HeLa cell line was calculated to be >1000 µg/ml. EBEAL showed selectivity indices (SI of >121.9 and >196.07 against MRC2 and RKL9 strains of P. falciparum, respectively. LD 50 of EBEAL was observed to be >5 g/kg. Dose-dependent chemosuppression was observed with significant ( p100 mg/kg. Significant (P<0.001 curative and repository activities were exhibited by 750 mg/kg concentration of extract on D7. Interpretation & conclusions: The present investigation reports antiplasmodial efficacy of EBEAL in vitro against P. falciparum as evident by high SI values. ED 50 of <100 mg/kg against P. berghei categorizes EBEAL as active antimalarial. Further studies need to be done to exploit its antiplasmodial activity further.

  2. Low-Dose CT for Evaluation of Suspected Urolithiasis: Diagnostic Yield for Assessment of Alternative Diagnoses.

    Science.gov (United States)

    Weinrich, Julius Matthias; Bannas, Peter; Regier, Marc; Keller, Sarah; Kluth, Luis; Adam, Gerhard; Henes, Frank Oliver

    2018-03-01

    The purpose of this study is to assess the diagnostic yield of low-dose (LD) CT for alternative diagnoses in patients with suspected urolithiasis. In this retrospective study, we included 776 consecutive patients who underwent unenhanced abdominal CT for evaluation of suspected urolithiasis. All examinations were performed with an LD CT protocol; images were reconstructed using iterative reconstruction. The leading LD CT diagnosis was recorded for each patient and compared with the final clinical diagnosis, which served as the reference standard. The mean (± SD) effective dose of CT was 1.9 ± 0.6 mSv. The frequency of urolithiasis was 82.5% (640/776). LD CT reached a sensitivity of 94.1% (602/640), a specificity of 100.0% (136/136), and an accuracy of 95.1% (738/776) for the detection of urolithiasis. In 93 of 136 patients (68.4%) without urolithiasis, alternative diagnoses were established as the final clinical diagnoses. Alternative diagnoses were most commonly located in the genitourinary (n = 53) and gastrointestinal (n = 18) tracts. LD CT correctly provided alternative diagnoses for 57 patients (61.3%) and was false-negative for five patients (5.4%). The most common clinical alternative diagnoses were urinary tract infections (n = 22). Seven diagnoses missed at LD CT were located outside the FOV. For 43 of all 776 patients (5.5%), neither LD CT nor clinical workup could establish a final diagnosis. The sensitivity, specificity, and accuracy of LD CT for the detection of alternative diagnoses were 91.9% (57/62), 95.6% (43/45), and 93.5% (100/107), respectively. LD CT enables the diagnosis of most alternative diagnoses in the setting of suspected urolithiasis. The most frequent alternative diagnoses missed by LD CT are urinary tract infections or diagnoses located outside the FOV of the abdominopelvic CT scan.

  3. Recombinant raccoon pox vaccine protects mice against lethal plague

    Science.gov (United States)

    Osorio, J.E.; Powell, T.D.; Frank, R.S.; Moss, K.; Haanes, E.J.; Smith, S.R.; Rocke, T.E.; Stinchcomb, D.T.

    2003-01-01

    Using a raccoon poxvirus (RCN) expression system, we have developed new recombinant vaccines that can protect mice against lethal plague infection. We tested the effects of a translation enhancer (EMCV-IRES) in combination with a secretory (tPA) signal or secretory (tPA) and membrane anchoring (CHV-gG) signals on in vitro antigen expression of F1 antigen in tissue culture and the induction of antibody responses and protection against Yersinia pestis challenge in mice. The RCN vector successfully expressed the F1 protein of Y. pestis in vitro. In addition, the level of expression was increased by the insertion of the EMCV-IRES and combinations of this and the secretory signal or secretory and anchoring signals. These recombinant viruses generated protective immune responses that resulted in survival of 80% of vaccinated mice upon challenge with Y. pestis. Of the RCN-based vaccines we tested, the RCN-IRES-tPA-YpF1 recombinant construct was the most efficacious. Mice vaccinated with this construct withstood challenge with as many as 1.5 million colony forming units of Y. pestis (7.7×104 LD50). Interestingly, vaccination with F1 fused to the anchoring signal (RCN-IRES-tPA-YpF1-gG) elicited significant anti-F1 antibody titers, but failed to protect mice from plague challenge. Our studies demonstrate, in vitro and in vivo, the potential importance of the EMCV-IRES and secretory signals in vaccine design. These molecular tools provide a new approach for improving the efficacy of vaccines. In addition, these novel recombinant vaccines could have human, veterinary, and wildlife applications in the prevention of plague.

  4. Microbiological aspects relating to the choice of radiation sterilization dose

    International Nuclear Information System (INIS)

    Whitby, J.L.

    1993-01-01

    Ionizing radiation is widely used for sterilization of single-use medical devices, and it is employed for its lethal effect on microbial life. Microbes are capable of regenerating from a single surviving cell, and individual cells of some microbial species are highly resistant to the lethal effects of radiation. It is necessary to employ radiation doses far in excess of those lethal to man or animals to ensure that no viable microbe remains to repopulate the device or the patient at the time that the device is used. Ionizations induce the production of short-lived free radicals that also induce lethal changes in cells. The sensitivity of microbial species to these changes varies markedly but since the changes are induced within the cell, each cell has to sustain the necessary amount of lethal damage before death will occur. Therefore the death of cells will occur in the exponential mode the surviving fraction decreasing with increasing dose. Using a semi-logarithmic plot, curves of three types may be generated, a simple exponential curve with a constant slope over the whole dose range, one where an initial shoulder is followed by a constant slope, and curves which are concave, and only seen in mixed bacterial populations of differing radiation resistance. (author)

  5. INSECTICIDAL AND OXIDATIVE EFFECTS OF AZADIRACHTIN ON THE MODEL ORGANISM Galleria mellonella L. (LEPIDOPTERA: PYRALIDAE).

    Science.gov (United States)

    Dere, Beyza; Altuntaş, Hülya; Nurullahoğlu, Z Ulya

    2015-07-01

    The insecticidal effects, specifically, changes in hemolymph total protein and malondialdehyde (MDA) levels, and antioxidant enzyme activities of azadirachtin (AZA) given to the wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae) larvae via force feeding were investigated. Bioassays showed that the LD50 and LD99 (lethal dose) values of AZA were 2.1 and 4.6 μg/larva, respectively. Experimental analyses were performed with five doses of AZA (0.5, 1, 1.5, 2, and 3 μg/larva). Total protein level in larval hemolymph increased at all AZA doses at 24 h whereas a considerable decrease was observed at 2 and 3 μg/larva doses, and only an increase displayed at 1.5 μg/larva at 72 h. The level of MDA increased at 2 and 3 μg/larva doses at 24 h compared with controls. This trend was also observed at 1.5, 2, and 3 μg/larva doses at 72 h and MDA levels were lower when compared with those of 24 h at all doses except for 1.5 μg/larva dose. Catalase activity decreased at 1, 1.5, and 2 μg/larva doses at 24 h whereas increased at all doses except for 0.5 μg/larva at 72 h compared with controls. AZA led to a decline in superoxide dismutase activity at all experimental doses at 24 and 72 h except for 3 μg/larva doses at 72 h. An increase in glutathione-S-transferase (GST) activity was evident at all AZA doses at 24 h. AZA displayed 68% decline in GST activity at 72 h post treatments when compared to 24 h. Consequently, We infer that the toxicity of AZA extends beyond its known actions in molting processes to redox homeostasis. © 2015 Wiley Periodicals, Inc.

  6. Water soluble vitamin E (TMG) as a radioprotector.

    Science.gov (United States)

    Nair, Cherupally Krishnan K; Devi, Pathirissery Uma; Shimanskaya, R; Kunugita, N; Murase, Hironobu; Gu, Yeun-Hwa; Kagiya, Tsutomu V

    2003-12-01

    Tocopherol monoglucoside (TMG), a water soluble derivative of vitamin E offers protection against deleterious effects of ionizing radiation, both under in vivo and in vitro conditions, to biological systems. TMG was found to be a potent antioxidant and an effective free radical scavenger. It forms a phenoxyl radical similar to trolox upon reaction with various one-electron oxidants. TMG protected DNA from radiation-induced strand breaks. It also protected thymine glycol formation induced by gamma-radiation. Gamma-radiation-induced loss of viability of EL-tumor cells and peroxidation of lipids in microsomal and mitochondrial membranes were prevented by TMG. TMG was nontoxic to mice when administered orally up to 7.0 g/kg body weight. The LD50 dose of TMG for ip administration in mice was 1.15 g/kg body wt. In rats, following oral and ip administration of TMG, the absorption (distribution) half lives were 5.8 and 3.0 min respectively and elimination half lives were 6.7 and 3.1 min respectively. Embryonic mortality resulting from exposure of pregnant mice to ionizing radiation (2 Gy) was reduced by 75% by ip administration of TMG (0.6 g/kg, body wt) prior to irradiation. TMG offered protection to mice against whole body gamma-radiation-induced lethality and weight loss. The LD50(30) of mice increased from 6 to 6.72 Gy upon post irradiation administration of a single dose of TMG (0.6 g/kg, body wt) by ip.

  7. General characteristics and comparative evaluation of radioprotective properties of adrenomimetics of the arylalxylamine series in experiments on mice

    International Nuclear Information System (INIS)

    Kulinskij, V.I.; Yashunskij, V.G.

    1979-01-01

    The radioprotective effect (RPE) of some arylalkylamines (AAA), mesaton and its nearest analogs has been studied in experiments on mice at subcutaneous injection 15 min prior to irradiation at the dose of 800 rad. It has been found that AAA is characterized by a low protective dose (25-50μmol/kg), a stable and high RPE 80-88% survival; dose reduction factor of 1.3-1.4 and low toxicity (LD 50 =4-8mmol/kg). The investigated AAA do not give in to aminothiols in effeciency and surpass the known aminothiols and indolylalkylamines in the pharmacological spectrum, K-LD 50 /ED 50 (200-500)

  8. Hiiumaa ettevõtete TOP 50

    Index Scriptorium Estoniae

    2005-01-01

    Hiiumaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Hiiumaa ettevõtete üld- ja finantsandmed; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20. Vt samas: Teeli Remmalg: Hiiumaal jätkub plastitööstuse võidumarss

  9. Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Suzuki, Kayo [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Nakamoto, Yuji [Kyoto University Hospital, Department of Diagnostic Radiology, Kyoto (Japan); Onishi, Yumiko; Sakamoto, Setsu; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Senda, Michio [Institute of Biomedical Research and Innovation, Department of Molecular Imaging, Kobe (Japan); Kita, Masato [Kobe City Medical Center General Hospital, Department of Obstetrics and Gynecology, Kobe (Japan)

    2010-08-15

    To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated {sup 18}F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer. A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months. Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT. PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations. (orig.)

  10. In vitro function of the aryl hydrocarbon receptor predicts in ...

    Science.gov (United States)

    Differences in sensitivity to dioxin-like compounds (DLCs) among species and taxa presents a major challenge to ecological risk assessments. Activation of the aryl hydrocarbon receptor (AHR) regulates adverse effects associated with exposure to DLCs in vertebrates. Prior investigations demonstrated that sensitivity to activation of the AHR1 (50% effect concentration; EC50) in an in vitro luciferase reporter gene (LRG) assay was predictive of the sensitivity of embryos (lethal dose to cause 50% lethality; LD50) across all species of birds for all DLCs. However, nothing was known about whether sensitivity to activation of the AHR is predictive of sensitivity of embryos of fishes to DLCs. Therefore, this study investigated in vitro sensitivities of AHR1s and AHR2s to the model DLC, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), among eight species of fish of known sensitivities of embryos to TCDD. AHR1s and AHR2s of all fishes were activated by TCDD in vitro. There was no significant linear relationship between in vitro sensitivity of AHR1 and in vivo sensitivity among the investigated fishes (R2 = 0.33, p = 0.23). However, there was a significant linear relationship between in vitro sensitivity of AHR2 and in vivo sensitivity among the investigated fishes (R2 = 0.97, p = fishes was compared to the previously generated linear relationship between in vitro s

  11. Ekspedeerimisettevõtete TOP 50

    Index Scriptorium Estoniae

    2006-01-01

    Ilmunud ka: Delovõje Vedomosti : Transport i Logistika nr. 11, 29. nov. lk. 32-35. Ekspedeerimisettevõtete TOP. Vt. samas: Käibe TOP 10; Käibekasvu TOP 10; Kasumi TOP 10; Kasumikasvu TOP 10; Rentaabluse TOP 10; ROE TOP 10; Ekspedeerimisettevõtete üld- ja finantsandmed. Ajal. Delovõje Vedomosti : Transport i Logistika toodud ainult Ekspedeerimisettevõtete TOP 50

  12. Võrumaa ettevõtete TOP 50 aastal 2003

    Index Scriptorium Estoniae

    2004-01-01

    Võrumaa ettevõtete TOP 50 aastal 2003. Käibe TOP 40. Kasumi TOP 40. Käibe kasvu TOP 20. Kasumi kasvu TOP 20. Rentaabluse TOP 20. Omakapitali tootlikkuse TOP 20. Võrumaa firmade üld- ja finantsandmed

  13. Caracterização da dose letal mínima por irradiação gama para Penicillium citrinum Characterization of minimum lethal dosis of gama irradiation to Penicillium citrinum

    Directory of Open Access Journals (Sweden)

    A. N. Norberg

    1993-12-01

    Full Text Available O uso das radiações ionizantes na destruição de microrganismos responsáveis pela deterioração de alimentos ou causadores de infecções ou toxinfecções alimentares, constituiu-se aplicação da energia nuclear, para fins verdadeiramente pacíficos. Penicillium citrinum é um fungo produtor de micotoxinas, responsáveis por intoxicações em humanos e animais que se utilizam de alimentos contaminados. Há escassez de informações sobre a resistência do P. citrinum à irradiação gama; assim esta pesquisa objetivou determinar a dose letal por irradiação gama para esse microrganismo. Foram irradiadas 76 suspensões, contendo aproximadamente 100.000 esporos por mililitro, com doses entre 0,2 e 2,2 KGy (KiloGray, sendo os sobreviventes re-irradiados com doses até 3,0 KGy. O fungo foi totalmente destruído com dose de 2,2 KGy. P. citrinum descendentes dos sobreviventes de 2,0 KGy, quando re-irradiados também foram totalmente destruídos com dose de 2,2 KGy. Observou-se um aumento da resistência às doses mais baixas em relação ao fungo não irradiadoThe use of nuclear power through radiation for the destruction of microrganisms which cause food decay, and toxicosis, is specifically for peaceful purposes. Penicillium citrinum is a fungus which produce mycotoxins responsible for intoxication in humans and animals as a result of eating contaminated food. There is little informations on the resistance of P. citrinum to radiation. The objective of this research is to determine the lethal dose of gama radiation for these microrganisms. Seventy six suspensions containing approximately 100,000 spores/ml received a dose of radiation between 0.2 and 2.2 KGy (KiloGray, being one sample still alive re-irradiated with doses up to 3.0 KGy. The fungus were totally destroyed with a 2.2 KGy. Seventy six suspensions containing approximately 100,000 spores/ml received a dose of radiation between 0.2 and 2.2 KGy, being one sample still alive re

  14. Availability of endogenous peptides limits expression of an M3a-Ld major histocompatibility complex class I chimera

    Science.gov (United States)

    1994-01-01

    Taking advantage of our understanding of the peptide specificity of the major histocompatibility complex class I-b molecule M3a, we sought to determine why these molecules are poorly represented on the cell surface. To this end we constructed a chimeric molecule with the alpha 1 and alpha 2 domains of M3a and alpha 3 of Ld thereby allowing use of available monoclonal antibodies to quantify surface expression. Transfected, but not control, B10.CAS2 (H-2M3b) cells were lysed readily by M3a-restricted monoclonal cytotoxic T lymphocytes. Thus, the chimera bound, trafficked, and presented endogenous mitochondrial peptides. However, despite high levels of M3a-Ld mRNA, transfectants were negative by surface staining. This finding was consistent with inefficient trafficking to the cell surface. Incubation at 26 degrees C, thought to permit trafficking of unoccupied heavy (H) chains, resulted in detectable cell surface expression of chimeric molecules. Incubation with exogenous peptide at 26 degrees C (but not at 37 degrees C) greatly enhanced expression of M3a-Ld molecules in a dose- dependent manner, suggesting stabilization of unoccupied molecules. Stable association of beta 2-microglobulin with the chimeric H chain was observed in labeled cell lysates only in the presence of exogenous specific peptide, indicating that peptide is required for the formation of a ternary complex. These results indicate that surface expression of M3a-Ld is limited largely by the steady-state availability of endogenous peptides. Since most known M3a-binding peptides are N- formylated, native M3a may normally be expressed at high levels only during infection by intracellular bacteria. PMID:8270862

  15. Effect of sublethal doses of radiation and cystamine on the dynamics of Rana temporaria L. larvae development

    International Nuclear Information System (INIS)

    Popov, D.V.

    1979-01-01

    The longevity of Rana temporaria L. larvae in the 45th stage of development is studied after irradiation in sublethal doses (10.000-20.000 R) and irradiation with preliminary cystamine protection. It has been shown that the protective effect of cystamine is revealed in partial normalization of the larvae development rate but does not eliminate the typical anomalies of extremity development and does not prolong the time of animal survival. It has been found that LD 50/30 dose for R. temporaria tadpoles in the 45th stage of development is slightly higher than 10.000 R. The selective effect of X-radiation on the formative bonds at cornea induction in Anura larvae is concluded

  16. Lactose malabsorption diagnosed by 50-g dose is inferior to assess clinical intolerance and to predict response to milk withdrawal than 25-g dose in an endemic area.

    Science.gov (United States)

    Ghoshal, Uday C; Kumar, Sunil; Misra, Asha; Mittal, Balraj

    2013-09-01

    Lactose malabsorption (LM), diagnosed currently using lactose hydrogen breath and tolerance tests (LHBT, LTT) with a high, nonphysiological dose (50-g), may mimic irritable bowel syndrome (IBS). In LM-endemic areas, clinically significant malabsorption (lactose intolerance) may be better diagnosed using a lesser dose, and positive results so obtained may predict response to milk withdrawal more effectively. Fifty patients each with IBS (Rome III) were evaluated using LHBT and LTT with 50-g, 25-g, and 12-g lactose. Sensitivity and specificity of LHBT and LTT with different dosages (gold standard: lactase gene C/T-13910 polymorphism) and symptom development were evaluated. Effect of milk withdrawal was studied. Of 150 patients, 37/50 (74%) and 28/50 (56%) had LM by LHBT and LTT using 50-g lactose; 41/50 (82%) and 31/50 (62%) had LM using 25-g lactose, and 14/50 (28%) and 29/50 (58%) using 12-g lactose, respectively. Sensitivity and specificity of LHBT using 50-g, 25-g, and 12-g lactose were 92.6%, 52.0%, and 94%, 60%, and 36.4%, 88.2%, and those of LTT, 92%, 80.0%, and 84.8%, 82.4%, and 66.7%, 58.8%, respectively. Breath hydrogen correlated with lactose dose. Though patients developing symptoms with 50-g lactose exhaled more hydrogen than those remaining asymptomatic, hydrogen levels did not differ following 25-g and 12-g dosages in relation to symptom development. Patients' milk intake was 335 ± 92 mL/d (≈ 16.7 ± 9.6-g lactose). Positive LHBT using 25-g dose better predicted symptom resolution than by 50-g and 12-g lactose. Twenty-five gram is the ideal dose of lactose for LHBT and LTT in LM-endemic areas. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  17. Postnatal Deletion of Fat Storage-inducing Transmembrane Protein 2 (FIT2/FITM2) Causes Lethal Enteropathy.

    Science.gov (United States)

    Goh, Vera J; Tan, Jolene S Y; Tan, Bryan C; Seow, Colin; Ong, Wei-Yi; Lim, Yen Ching; Sun, Lei; Ghosh, Sujoy; Silver, David L

    2015-10-16

    Lipid droplets (LDs) are phylogenetically conserved cytoplasmic organelles that store neutral lipids within a phospholipid monolayer. LDs compartmentalize lipids and may help to prevent cellular damage caused by their excess or bioactive forms. FIT2 is a ubiquitously expressed transmembrane endoplasmic reticulum (ER) membrane protein that has previously been implicated in LD formation in mammalian cells and tissue. Recent data indicate that FIT2 plays an essential role in fat storage in an in vivo constitutive adipose FIT2 knock-out mouse model, but the physiological effects of postnatal whole body FIT2 depletion have never been studied. Here, we show that tamoxifen-induced FIT2 deletion using a whole body ROSA26CreER(T2)-driven FIT2 knock-out (iF2KO) mouse model leads to lethal intestinal pathology, including villus blunting and death of intestinal crypts, and loss of lipid absorption. iF2KO mice lose weight and die within 2 weeks after the first tamoxifen dose. At the cellular level, LDs failed to form in iF2KO enterocytes after acute oil challenge and instead accumulated within the ER. Intestinal bile acid transporters were transcriptionally dysregulated in iF2KO mice, leading to the buildup of bile acids within enterocytes. These data support the conclusion that FIT2 plays an essential role in regulating intestinal health and survival postnatally. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Formative assessment with IMS LD and IMS QTI

    NARCIS (Netherlands)

    Tattersall, Colin; Burgos, Daniel; Vogten, Hubert

    2006-01-01

    The presentation descibes work on the integtation of LD and QTI, and the realisation of this research via CCSI. Furthermore, the presentation describes ongoing work in TENCompetence in the area of assessment.

  19. Anti-Hyperlipidaemic and Heart Rate Lowering Effects of Aqueous ...

    African Journals Online (AJOL)

    The anti-hyperlipidaemic and heart rate lowering potential of aqueous leaf extract of Viscum album (mistletoe) in hypercholesterolaemic rats was investigated in this study. The lethality studies showed that the aqueous extract of the plant had an LD50 value of 452.20mg/kg by intraperitoneal route. There were significant ...

  20. OH radicals from the indirect actions of X-rays induce cell lethality and mediate the majority of the oxygen enhancement effect.

    Science.gov (United States)

    Hirayama, Ryoichi; Ito, Atsushi; Noguchi, Miho; Matsumoto, Yoshitaka; Uzawa, Akiko; Kobashi, Gen; Okayasu, Ryuichi; Furusawa, Yoshiya

    2013-11-01

    We examined OH radical-mediated indirect actions from X irradiation on cell killing in wild-type Chinese hamster ovary cell lines (CHO and AA8) under oxic and hypoxic conditions, and compared the contribution of direct and indirect actions under both conditions. The contribution of indirect action on cell killing can be estimated from the maximum degree of protection by dimethylsulfoxide, which suppresses indirect action by quenching OH radicals without affecting the direct action of X rays on cell killing. The contributions of indirect action on cell killing of CHO cells were 76% and 50% under oxic and hypoxic conditions, respectively, and those for AA8 cells were 85% and 47%, respectively. Therefore, the indirect action on cell killing was enhanced by oxygen during X irradiation in both cell lines tested. Oxygen enhancement ratios (OERs) at the 10% survival level (D10 or LD90) for CHO and AA8 cells were 2.68 ± 0.15 and 2.76 ± 0.08, respectively. OERs were evaluated separately for indirect and direct actions, which gave the values of 3.75 and 2.01 for CHO, and 4.11 and 1.32 for AA8 cells, respectively. Thus the generally accepted OER value of ∼3 is best understood as the average of the OER values for both indirect and direct actions. These results imply that both indirect and direct actions on cell killing require oxygen for the majority of lethal DNA damage, however, oxygen plays a larger role in indirect than for direct effects. Conversely, the lethal damage induced by the direct action of X rays are less affected by oxygen concentration.

  1. Testing of new hypoxic cell sensitizers in vivo

    International Nuclear Information System (INIS)

    Stone, H.B.; Sinesi, M.S.

    1982-01-01

    We tested five agents as potential sensitizers of hypoxic cells in vivo in mammary tumors in C3H mice in comparison with misonidazole. The LD/sub 50/2/ for desmethylmisonidazole was 2.7 mg/g body wt, compared to 1.3 for misonidazole. It was as effective in reducing the TCD 50 of MDAH-MCa-4 as were equitoxic doses of misonidazole. the LD/sub 50/2/ of SR-2508 was 3.3 mg/g and was as effective a sensitizer as misonidazole. Ro 07-0741 was more toxic, with an LD/sub 50/2/ of 0.6 mg/g, but was as effective as misonidazole at equitoxic doses. NP-1 was also more toxic than misonidazole (LA/sub 50/2/ = 04 mg/g) but was a less effective sensitizer. Rotenone, which causes sensitization by inhibiting cellular respiration, thus increasing the diffusion distance of oxygen, was extremely toxic (LD/sub 50/2/ - 0.003 mg/g), and systemic respiratory inhibition and the radioprotective effects of the dimethyl sulfoxide used to dissolve it rendered it totally ineffective as a sensitizer in vivo

  2. The essential oil of Brazilian pepper, Schinus terebinthifolia Raddi in larval control of Stegomyia aegypti (Linnaeus, 1762).

    Science.gov (United States)

    Silva, Ary G; Almeida, Drielle L; Ronchi, Silas N; Bento, Amarildo C; Scherer, Rodrigo; Ramos, Alessandro C; Cruz, Zilma Ma

    2010-08-27

    The ability of mosquitoes of the genus Aedes and its allies, such as Stegomyia, to transmit diseases such as dengue and yellow fever, makes them important in public health. This study aims to evaluate the use of the essential oil of Brazilian pepper in biological control of by assessing and quantifying the larvicidal effect against S. aegypti, the only available access to dengue control, and test its risk of genotoxicity with Salmonella typhimurium as an indicator of safety for its environmental use. The density of the oil was 0.8622 g mL-1. Gas chromatography coupled with mass spectrometry revealed six major constituents: δ-3-carene (55.43%), α-pinene (16.25%), sylvestrene (10.67%), germacrene D (2.17), β-myrcene (1.99%), and isoterpinolene (1.4%). The minimum inhibitory dose to larvae development was 862.20 μg mL-1. The median lethal dose (LD50) of the essential oil for larvae was between the concentrations of 172.44-344.88 μg mL-1. There was no mutagenic risk for the essential oil, since there were no biochemical or morphological changes in S. typhimurium after exposure to the essential oil. The minimum inhibitory essential oil concentration and the median lethal dose pointed to the value of the use of water dispersions of Brazilian pepper essential oil as an environmental safe natural larvicidal for S. aegypti.

  3. Effect of gamma irradiation on Lasioderma serricorne (Fabricius, 1792) (Coleoptera, Anobidae)

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Arthur, V.

    1975-01-01

    The results obtained when studying the effect of gamma-irradiation during the different phases of the development cycle of Lasioderma serricorne (Fabr.,1792) is presented. Lethal doses for eggs and adults, as well as hatching of adults when irradiation was applied to larvae and pupae were determined. Also determined was the fertility of adults when the pupae, or the adults themselves, were irradiated. As a result, inhibition of larval hatching was obtained with a dose of 5 krad, and a immediate lethal dose (LD(sub)I) for adults of more than 475 krad was found. Doses for larvae irradiation which resulted in non-hatching of adults were over 27 krad. 30 krad were not sufficient for pupae to inhibit hatching. 10 krad doses can be considered as sterilizing doses for pupae or adults, as the appliance of 10 krad doses to pupae resulted in only 0,217% fertility, whereas a dose of 9 krad in adults caused a progeny of only 0,25%, in comparison to the control [pt

  4. 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

  5. Effect of salinity on the upper lethal temperature tolerance of early-juvenile red drum.

    Science.gov (United States)

    McDonald, Dusty; Bumguardner, Britt; Cason, Paul

    2015-10-01

    Previous work investigating the temperature tolerance of juvenile red drum ranging 18-50mm TL found evidence for positive size dependence (smaller fish less tolerant to higher temperatures) suggesting smaller size classes (temperatures. Here, we explored the upper lethal temperature tolerance (ULT) in smaller-sized red drum which ranged from 10 to 20mm TL across multiple salinities to further understand the thermal limitations of this propagated game fish. In order to investigate the combined effect of temperature and salinity on ULT, temperature trials were conducted under three levels of salinity which commonly occur along the coast of Texas (25, 35, and 45ppt). The rate of temperature increase (+0.25°C/h) was designed to mimic a natural temperature increase of a summer day in Texas. We determined that the lethal temperature at 50% (LT50) did not differ between the three salinities examined statistically; median lethal temperature for individuals exposed to 25ppt ranged from 36.4 to 37.7°C, 35ppt ranged from 36.4 to 37.7°C, and 45ppt ranged from 36.1 to 37.4°C. Further, LT50 data obtained here for early-juvenile red drum did not differ from data of a similar experiment examining 25mm TL sized fish. Published by Elsevier Ltd.

  6. Vasoactive and radioprotective properties of isothiourea derivatives having NOS-inhibitory activity

    Energy Technology Data Exchange (ETDEWEB)

    Filimonova, Marina V.; Shevchenko, Ludmila I.; Ulyanenko, Stepan E.; Makarchuk, Victorya M.; Kuznetsova, Mary N.; Shevchuk, Aza S.; Lushnikova, Galina A.; Chesnakova, Ekaterina A. [Medical Radiological Research Center Health Ministry of Russia, 4, Korolev street, Obninsk, 249036, Kaluga region (Russian Federation)

    2014-07-01

    We studied vasoactive and radioprotective properties of new original N-acyl, S-alkyl isothiourea derivatives which are potent inhibitors of nitric oxide synthases (preferably eNOS and iNOS). These compounds have a moderate toxicity (LD50 - 400-550 mg/kg), and are stable in aqueous solutions. In hemodynamic studies, these compounds exhibited high vasotropic activity. The use of these compounds in doses of 5-15 mg/kg (0,01-0,03 LD{sub 50}) in the experimental animals in a state of the severe hemorrhagic or endo-toxic shock causes a potent vasopressor effect, accompanied by a significant and continuous rise in blood pressure. The increasing of vascular tone developed over 2-5 min after injection and persisted for at least 60-90 minutes, excelling at least 3-5 times the duration of α1-adreno-mimetic vasopressor action. The rapid increase in vascular tone under the influence of these compounds in normo-tonic animals caused protective baroreflex to prevent high blood pressure. At doses of 10-15 mg/kg the reflex reaction was mild, but at higher doses (30-40 mg/kg) the reaction was fierce and prolonged, and was accompanied by severe bradycardia, decreasing of the cardiac output and a significant weakening of the peripheral blood flow. In all cases, the hemodynamic response was reflexive and easily eliminated by atropine. The ability of these compounds to induce circulatory hypoxia was the basis for the study of their radioprotective properties. The study of radioprotective effect on the survival of animals exposed to lethal doses of γ-radiation (10 Gy) and on the survival of hematopoietic clonogenic cells showed that these compounds in doses of 80-150 mg/kg (0,2-0,3 LD50) have considerable radioprotective action, which is comparable with the protective effect of the maximum tolerated dose of cystamine. The factor of change in dose for γ-radiation, estimated by the LD{sub 50}, was 1,42-1,58. We also investigated the ability of the test compounds, due to their hypoxic

  7. Suicide Lethality: A Concept Analysis.

    Science.gov (United States)

    DeBastiani, Summer; De Santis, Joseph P

    2018-02-01

    Suicide is a significant health problem internationally. Those who complete suicide may have different behaviors and risk factors than those who attempt a non-fatal suicide. The purpose of this article is to analyze the concept of suicide lethality and propose a clear definition of the concept through the identification of antecedents, attributes, and consequences. A literature search for articles published in the English language between 1970 and 2016 was conducted using MEDLINE, the Cochrane Library, Pubmed, Psychlit, Ovid, PsycINFO, and Proquest. The bibliographies of all included studies were also reviewed to identify additional relevant citations. A concept analysis was conducted on the literature findings using six stages of Walker and Avant's method. The concept analysis differentiated between suicide, lethality, suicidal behavior, and suicide lethality. Presence of a suicide plan or a written suicide note was not found to be associated with the majority of completed suicides included in the definition of suicide lethality. There are a few scales that measure the lethality of a suicide attempt, but none that attempt to measure the concept of suicide lethality as described in this analysis. Clarifying the concept of suicide lethality encourages awareness of the possibility of different suicidal behaviors associated with different suicide outcomes and will inform the development of future nursing interventions. A clearer definition of the concept of suicide lethality will guide clinical practice, research, and policy development aimed at suicide prevention.

  8. Morfologic anomalies in the spermatozoid heads caused by isolated and combined effects of external ionizing radiation and chemical factor

    International Nuclear Information System (INIS)

    Shopova, V.; Nechev, Khr.; Sylovski, P.

    1985-01-01

    The test for recording morphologic anomalies in the spermatozoid heads and the genotoxic effect of isolated and combined treatment with the preparation chloracetophone and external ionizing radiation was applied on of mice line C 57 Bl. Evaluation of the morphologic anomalies in the spermatozoa rested upon two staining method, one of which helped to distinguish the acrosome. It was demonstrated that chloracetophone given in a single high dose (1/2 and 1/4 LD 50 ) was genotoxic. Ionizing radiation induced the expected positive effect. After combined application of 5x1/5 LD 50 chloracetophone and 1 and 4 Gy irradiation dose, it was the effect of radiation that was recorded. Only in the group in which both noxious agents were combined in effective doses (1/2 LD 50 chloracetophone and 1 Gy) there was a tendency toward additive effect

  9. Lethal Zika Virus Disease Models in Young and Older Interferon α/β Receptor Knock Out Mice

    Directory of Open Access Journals (Sweden)

    Andrea Marzi

    2018-04-01

    Full Text Available The common small animal disease models for Zika virus (ZIKV are mice lacking the interferon responses, but infection of interferon receptor α/β knock out (IFNAR−/− mice is not uniformly lethal particularly in older animals. Here we sought to advance this model in regard to lethality for future countermeasure efficacy testing against more recent ZIKV strains from the Asian lineage, preferably the American sublineage. We first infected IFNAR−/− mice subcutaneously with the contemporary ZIKV-Paraiba strain resulting in predominantly neurological disease with ~50% lethality. Infection with ZIKV-Paraiba by different routes established a uniformly lethal model only in young mice (4-week old upon intraperitoneal infection. However, intraperitoneal inoculation of ZIKV-French Polynesia resulted in uniform lethality in older IFNAR−/− mice (10–12-weeks old. In conclusion, we have established uniformly lethal mouse disease models for efficacy testing of antivirals and vaccines against recent ZIKV strains representing the Asian lineage.

  10. Low-dose myocardial blood flow imaging using 82Rb-PET (RUBILOW 2.0)

    DEFF Research Database (Denmark)

    Hoff, Camilla Molich; Tolbod, Lars Poulsen; Harms, Hans

    2017-01-01

    Aim: Relative and absolute measures of myocardial blood flow (MBF) can be derived from a 82Rb PET/CT scan using list mode data to extract static, gated and dynamic PET series. High doses of 82Rb are used to maximize image quality in especially static images. High doses require large eluate volumes......, may degrade scanner dead time performance at first pass and decreases generator lifetime. Lower doses will expand the availability of 82Rb PET/CT and lower doses to personnel and patients. The aim of the current study was to examine MBF with a low dose (LD) 82Rb protocol compared to the institution......’s standard (STD) protocol. Methods: Twenty-one patients referred to 82Rb PET were included in the study. Patients were examined during rest and stress with repeated LD (740 MBq) and STD dose (1110 MBq) Rb-PET during the same imaging session. Regional and global rest and stress MBF values, total perfusion...

  11. Lethal Effects of Lambda-Cyhalothrin and Demand® CS on Asian Longhorned Beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae): Implications for Population Suppression, Tree Protection, Eradication and Containment

    Science.gov (United States)

    We evaluated the 24h contact toxicity of lambda-cyhalothrin for adult Asian longhorned beetle, Anoplophora glabripennis Motschulsky, using topical application. Results showed that beetles are sensitive to lambda-cyhalothrin: the LD50 and LD90 were 0.13639 and 0.78461µg/beetle, respectively. Residual...

  12. The effect of gamma radiation on the rice moth, Corcyra Cephalonica (Staint). Part II irradiation of the eggs, pupae, and adults

    International Nuclear Information System (INIS)

    Loaharanu, S.; Sutantawong, M.; Ungsunanatwiwat, A.

    1971-01-01

    The 1-3 days old eggs of the rice moth were exposed to gamma rays at 0, 3, 6, 12.5 and 25 krads. The LD 50 and LD 99 for eggs was estimated as 9 and 42 krads respectively. A dose of 25 krads caused 100% mortality in larvae irradiated as egg stage. Mixed ages of 1-7 days old pupae were subjected to 0, 6, 12.5, 25, 50 and 100 Krads of gamma rays. Based on number of adults emerged, the LD 50 and LD 99 for pupae were estimated as 19 and 110 krads. Mixed sexes of 1-3 days old adult moths were also exposed to gamma rays. The LD 50 and LD 99 for adults appeared to be 60 and 170 krads respectively. Irradiation of both sexes of adult moths at 25 and 50 krads, led to complete infertility in eggs deposited

  13. Effect of gamma irradiation on the hatchability and embryonic development of quail eggs

    International Nuclear Information System (INIS)

    Oroszlany, P.; Sinkovicsne Hlubik, I.

    1979-01-01

    The effect of different doses of gamma irradiation on the embryonic development of quail and hen's eggs was examined. The goals of the examinations were to determine the LD 50 and LD 100 values, to establish the effect of single and multiple irradiation on embryonic development and to get some information on the embryonation of eggs produced by quails and their progeny grown from irradiated eggs. It was shown that 200 rad dose has significant stimulation effect of the hatching results of quail eggs. The LD 50 and LD 100 values were about 800 to 850 rad and 1600 rad, respectively. Repeated irradiation on the progeny-generations proved to be unambiguously deleterious on embryonation. High doses changed the rhythm of embryonal mortality, showing a peak under the irradiation and in the first three days of incubation, and significantly enhanced the number of teratological types. (author)

  14. Acute and subchronic toxicity of the antitumor agent rhodium (II citrate in Balb/c mice after intraperitoneal administration

    Directory of Open Access Journals (Sweden)

    Marcella L.B. Carneiro

    2015-01-01

    Full Text Available This study aimed to investigate potential acute and subchronic toxicity of rhodium (II citrate in female Balb/c mice after intraperitoneal injections. In the acute test, independent groups received five doses; the highest dose (107.5 mg/kg was equivalent to 33 times that used in our previous reports. The other doses were chosen as proportions of the highest, being 80.7 (75%, 53.8 (50%, 26.9 (25% or 13.8 mg/kg (12.5%. Animals were monitored over 38 days and no severe signs of toxicity were observed, according to mortality, monitoring of adverse symptoms, hematological, biochemical and genotoxic parameters. We conclude that the median lethal dose (LD50 could be greater than 107.5 mg/kg. In the subchronic test, five doses of Rh2Cit (80, 60, 40, 20 or 10 mg/kg were evaluated and injections were conducted on alternate days, totaling five applications per animal. Paclitaxel (57.5 mg/kg and saline solution were controls. Clinical observations, histopathology of liver, lung and kidneys and effects on hematological, biochemistry and genotoxic records indicated that Rh2Cit induced no severe toxic effects, even at an accumulated dose up to 400 mg/kg.We suggest Rh2Cit has great potential as an antitumor drug without presenting acute and subchronic toxicity.

  15. The Antinociceptive Effects of Tramadol and/or Gabapentin on Rat Neuropathic Pain Induced by a Chronic Constriction Injury.

    Science.gov (United States)

    Corona-Ramos, Janette Nallely; De la O-Arciniega, Minarda; Déciga-Campos, Myrna; Medina-López, José Raúl; Domínguez-Ramírez, Adriana Miriam; Jaramillo-Morales, Osmar Antonio; Espinosa-Juárez, Josué Vidal; López-Muñoz, Francisco Javier

    2016-08-01

    Preclinical Research The current work evaluates the interaction between two commonly used drugs, tramadol (Tra) and gabapentin (Gbp). Dose-response curves (DRC) and isobolographic analysis were used to confirm their synergistic antihyperalgesic and anti-allodynic responses in a rat neuropathic pain model involving chronic constriction injury of the sciatic nerve and in von Frey and acetone tests. Tra and Gbp produced dose-dependent antihyperalgesic and anti-allodynic effects. Dose-response studies of combinations of Tra and Gbp in combination showed the DRC was leftward-shifted compared to the DRCs for each compound alone. One combination demonstrated both antihyperalgesic and anti-allodynic effects greater than those observed after individual administration. The remaining combinations demonstrated an additive effect. The Tra+Gbp combination demonstrated a potentiative effect with smaller doses of Tra. Additionally, it was determined lethal dose 50 (LD50 ) of Tra alone and tramadol + Gbp 10 using mice to 48 h post administration. The DRC (death) were similar for Tra alone and in Tra in combination, despite the improved effectiveness of Tra in the presence of GBP, 10 mg/kg. A combination of these drugs could be effective in neuropathic pain therapy because they can produce potentiative (at a low dose) or additive effects. Drug Dev Res 77 : 217-226, 2016.   © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Läänemaa ettevõtete TOP 50

    Index Scriptorium Estoniae

    2005-01-01

    Läänemaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Läänemaa ettevõtete üld- ja finantsandmed

  17. Synergistic effects of chlorpyrifos with piperonyl butoxide (pbo against the lesser mealworm, Alphitobius diaperinus (Panzer (Coleoptera: Tenebrionidae

    Directory of Open Access Journals (Sweden)

    Akter Mst Yeasmin

    2014-12-01

    Conclusions: The study suggests that the mortality rate of lesser meal worm is increase with the increase of insecticide dose. The LD50 values of the insecticides are inversely related to the toxicity of the insecticides i.e. higher the LD50 value lower the toxicity of the insecticide.

  18. Evaluation of the OSI LD1200 optical diskdrive

    International Nuclear Information System (INIS)

    Burger, J.M.

    1986-01-01

    This document describes the testing of a laser-diskdrive of Optical Storage International, model LD1200. The aim was to test the hardware and media reliability and to verify some of the vendor supplied specifications. (Auth.)

  19. Fundamental image quality limits for microcomputed tomography in small animals

    International Nuclear Information System (INIS)

    Ford, N.L.; Thornton, M.M.; Holdsworth, D.W.

    2003-01-01

    resolution to improve, by decreasing the detector element size to tens of microns or less, high quality images will be limited by the x-ray dose administered. For the highest quality images, these doses will approach the lethal dose or LD50 for the animals. Approaching the lethal dose will affect the way experiments are planned, and may reduce opportunities for experiments involving imaging the same animal over time. Dose considerations will become much more important for live small-animal imaging as the limits of resolution are tested

  20. Low survival of mice following lethal gamma-irradiation after administration of inhibitors of prostaglandin synthesis

    International Nuclear Information System (INIS)

    Hofer, M.; Pospisil, M.; Tkadlecek, L.; Viklicka, S.; Pipalova, I.; Hola, J.

    1992-01-01

    An impairment was observed of the survival of mice subjected to whole-body gamma-irradiation with a lethal dose of 10 Gy and treated with a repeated postirradiation administration of the prostaglandin synthesis inhibitors (PGSIs) indomethacin or diclofenac. Morphological examination of the gastrointestinal tract and estimation of the blood loss into its lumen in animals treated with diclofenac did not show serious damage such as hemorrhages or perforation, but revealed structural injury to the intestinal mucosa indicating inflammatory processes. The lesions found are supposed to be connected with increased intestinal permeability which leads to endotoxin escape from the gut and a subsequent increased mortality rate of irradiated animals. It may be concluded that PGSIs are not suitable for the management of radiation sickness after an exposure to lethal doses of ionizing radiation. (author) 2 tabs., 4 figs., 20 refs

  1. Interactive lethal and mutagenic effects of ultraviolet light and bleomycin in yeast: synergism or antagonism?

    Science.gov (United States)

    Lillo, O L; Severgnini, A A; Nunes, E M

    1997-11-01

    The mutagenic interactions of ultraviolet light and bleomycin in haploid populations of Saccharomyces cerevisiae were analyzed. Survival and mutation frequency as a function of different bleomycin concentrations after one conditioning dose of UV radiation were determined. Furthermore, corresponding interaction functions and sensitization factors were calculated. A synergistic interaction between UV light and bleomycin was shown for both lethal and mutagenic events when the cells were in nutrient broth during the treatments. Conversely, the interaction between UV light and bleomycin was antagonistic when the cells were in deionized water during the treatment. The magnitude of lethal and mutagenic interactions depends on dose, and thus presumably on the number of lesions. The observed interactions between UV light and bleomycin suggest that the mechanism that is most likely involved is the induction of repair systems with different error probabilities during the delay of cell division.

  2. Impact of enhancin genes on potency of LdNPV in gypsy moth

    Science.gov (United States)

    Kelli Hoover; Jim McNeil; Alyssa Gendron; James. Slavicek

    2011-01-01

    Lymantria dispar nucleopolyhedrovirus (LdNPV) contains two enhancin genes (E1 and E2) encoding proteases that degrade key peritrophic matrix (PM) proteins, thereby promoting infection and mortality by the virus. In a previous study, gypsy moth larvae inoculated with LdNPV in which both E1 and E2 were deleted (double deletion virus) resulted in a non-...

  3. Restoring efficiency of hemopoietic cell transplantation in a mouse lethally irradiated by a total exposure to X rays

    International Nuclear Information System (INIS)

    Doria, Gino

    1959-10-01

    This research thesis reports the study of possibility of treatments (or restoration) of a mouse which has been submitted to a lethal dose of X rays. More particularly, the author compared the restoring efficiency of bone marrow and fetal liver injected in a mouse which had been lethally irradiated by a total exposure to X rays. He also studied the functional status of the hemopoietic graft, and the emergence of the secondary disease in mice which had been as well lethally irradiated and then restored by injection of bone marrow and fetal liver. The author then addressed the influence of the induction of immune tolerance of the host with respect to the donor on the survival of a mouse lethally irradiated and restored by homologue bone marrow [fr

  4. Fetal dose from radiotherapy photon beams: Physical basis, techniques to estimate radiation dose outside of the treatment field, biological effects and professional considerations

    International Nuclear Information System (INIS)

    Stovell, Marilyn; Blackwell, C. Robert

    1997-01-01

    Purpose/Objective: The presentation will review: 1. The physical basis of radiation dose outside of the treatment field. 2. Techniques to estimate and reduce fetal dose. 3. Clinical examples of fetal dose estimation and reduction. 4. Biological effects of fetal irradiation. 5. Professional considerations. Approximately 4000 women per year in the United States require radiotherapy during pregnancy. This report presents data and techniques that allow the medical physicist to estimate the radiation dose the fetus will receive and to reduce this dose with appropriate shielding. Out-of-beam data are presented for a variety of photon beams, including cobalt-60 gamma rays and x rays from 4 to 18 MV. Designs for simple and inexpensive to more complex and expensive types of shielding equipment are described. Clinical examples show that proper shielding can reduce the radiation dose to the fetus by 50%. In addition, a review of the biological aspects of irradiation enables estimates of the risks of lethality, growth retardation, mental retardation, malformation, sterility, cancer induction, and genetic defects to the fetus. A summary of professional considerations/recommendations is also provided as a guide for the radiation oncologist and medical physicist

  5. Acute and subchronic toxicity of naturally weathered Exxon Valdez crude oil in mallards and ferrets

    International Nuclear Information System (INIS)

    Stubblefield, W.A.; Hancock, G.A.; Ford, W.H.; Ringer, R.K.

    1995-01-01

    The toxic properties of naturally weathered Exxon Valdez crude oil (WEVC) were assessed in a battery of acute and subchronic toxicity tests using mallards, Anas platyrhynchos, and European ferrets, Mustela putorius. Adult mallard acute oral toxicity study results indicated no mortalities or signs o toxicity, i.e., no-observed-adverse-effect level (NOAEL) and median lethal dose (LD50) > 5,000 mg/kg. Acute oral feeding and food avoidance tests with ducklings also indicated no toxicity (NOAEL and LC50 > 50,000 mg/kg diet) with no evidence of food avoidance (FAC50 > 20,000 mg/kg diet). No mortalities or toxic signs were noted in a 14-d feeding study with adult birds at dietary concentrations up to 100,000 mg WEVC/kg diet. Among clinical and physiological end points evaluated, the only significant difference noted was an increase in liver: body weight ratios in the 100,000-mg WEVC/kg diet dose group. No differences in clinical chemistry or hematological parameters were noted, and there were no consistent differences in histological evaluations of organ tissues. Daily oral doses of up to 5,000 mg/kg of WEVC over 5 d resulted in minimal effects on ferrets. Increased serum albumin concentrations were observed in the 5,000-mg/kg dose group females and decreased spleen weights were noted in females of all WEVC treatment groups. No other significant observations were noted

  6. Development of quantitative structure-activity relationship (QSAR) models to predict the carcinogenic potency of chemicals

    International Nuclear Information System (INIS)

    Venkatapathy, Raghuraman; Wang Chingyi; Bruce, Robert Mark; Moudgal, Chandrika

    2009-01-01

    Determining the carcinogenicity and carcinogenic potency of new chemicals is both a labor-intensive and time-consuming process. In order to expedite the screening process, there is a need to identify alternative toxicity measures that may be used as surrogates for carcinogenic potency. Alternative toxicity measures for carcinogenic potency currently being used in the literature include lethal dose (dose that kills 50% of a study population [LD 50 ]), lowest-observed-adverse-effect-level (LOAEL) and maximum tolerated dose (MTD). The purpose of this study was to investigate the correlation between tumor dose (TD 50 ) and three alternative toxicity measures as an estimator of carcinogenic potency. A second aim of this study was to develop a Classification and Regression Tree (CART) between TD 50 and estimated/experimental predictor variables to predict the carcinogenic potency of new chemicals. Rat TD 50 s of 590 structurally diverse chemicals were obtained from the Cancer Potency Database, and the three alternative toxicity measures considered in this study were estimated using TOPKAT, a toxicity estimation software. Though poor correlations were obtained between carcinogenic potency and the three alternative toxicity (both experimental and TOPKAT) measures for the CPDB chemicals, a CART developed using experimental data with no missing values as predictor variables provided reasonable estimates of TD 50 for nine chemicals that were part of an external validation set. However, if experimental values for the three alternative measures, mutagenicity and logP are not available in the literature, then either the CART developed using missing experimental values or estimated values may be used for making a prediction

  7. Determination of the Median Lethal Dose and Electrophoretic Pattern of Hottentotta saulcyi (Scorpiones, Buthidae Scorpion Venom

    Directory of Open Access Journals (Sweden)

    ErsenAydın Yağmur

    2015-10-01

    Full Text Available Background: In this study, we investigated the lethal potency, electrophoretic protein pattern and in vivo effects of Hottentotta saulcyi scorpion venom in mice.Methods: Scorpions were collected at night, by using a UV lamp from Mardin Province, Turkey. Venom was obtained from mature H. saulcyi scorpions by electrical stimulation of the telson. The lethality of the venom was determined by i.v. injections using Swiss mice. In vivo effects of the venom were assessed by using the intraperitoneal route (ip injections into mice (20±1g and monitored for 24 h. The protein profiles of the scorpion venom were analyzed by NuPAGE® Novex® 4–12 % gradient Bis-Tris gel followed by Coomassie blue staining.Results: The lethal assay of the venom was 0.73 mg/kg in mice. We determined the electrophoretic protein pattern of this scorpion venom to be 4, 6, 9, 31, 35, 40, 46 and 69 kDa by SDS-PAGE. Analysis of electrophoresis indicated that H. saulcyi scorpion intoxicated mice exhibited autonomic nervous system symptoms (tachypnea, restlessness, hyperexcitability, convulsions, salivation, lacrimation, weakness.Conclusions: Hottentotta saulcyi scorpion venom includes short-chain neurotoxins and long-chain neurotoxins according to the electrophoretic protein patterns. The stings of H. saulcyi scorpion must be considered of risk for humans in the southeastern region, Turkey.

  8. Nils Silfverskiöld (1888-1957) and gastrocnemius contracture.

    Science.gov (United States)

    Singh, Dishan

    2013-06-01

    Nils Silfverskiöld was an orthopaedic surgeon, Swedish aristocrat, bon vivant, Olympic gymnast, left wing intellectual and anti-Nazi who described that the force required to dorsiflex the ankle in spastic equinus contracture decreased with knee flexion in isolated gastrocnemius contracture. He advocated detaching the origins of the gastrocnemii from the femur and reattaching them to the tibia. The Silfverskiöld knee flexion test has now also been adapted to distinguish between isolated gastrocnemius contracture and combined shortening of the gastrocnemius-soleus complex in non-spastic contracture by measuring the range of ankle dorsiflexion with the knee flexed and the knee straight. Copyright © 2012 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  9. Lethal and Sublethal Effects of Fenpropathrin on the Biological Performance of Scolothrips longicornis (Thysanoptera: Thripidae)

    DEFF Research Database (Denmark)

    Pakyari, Hajar; Enkegaard, Annie

    2013-01-01

    Determination of negative nontarget effects of pesticides on beneficial organisms by measuring only lethal effects is likely to underestimate effects of sublethal doses. In this study, the sublethal effects of fenpropathrin on the predatory thrips Scolothrips longicornis Priesner (Thysanoptera: T...

  10. Diagnostic accuracy of low-dose versus ultra-low-dose CT for lumbar disc disease and facet joint osteoarthritis in patients with low back pain with MRI correlation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sun Hwa [Inje University College of Medicine, Department of Emergency Medicine, Sanggye Paik Hospital, Nowon-gu (Korea, Republic of); Yun, Seong Jong; Jo, Hyeon Hwan; Kim, Dong Hyeon [Republic of Korea Air Force, Department of Radiology, Aerospace Medical Center, Cheongwon-gun, Chungcheongbuk-do (Korea, Republic of); Song, Jae Gwang [Republic of Korea Air Force, Department of Orthopedic Surgery, Aerospace Medical Center, Cheongwon-gun, Chungcheongbuk-do (Korea, Republic of); Park, Yong Sung [Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Department of Radiology, Seoul (Korea, Republic of)

    2018-04-15

    To compare the image quality, radiation dose, and diagnostic performance between low-dose (LD) and ultra-low-dose (ULD) lumbar-spine (L-spine) CT with iterative reconstruction (IR) for patients with chronic low back pain (LBP). In total, 260 patients with chronic LBP who underwent L-spine CT between November 2015 and September 2016 were prospectively enrolled. Of these, 143 underwent LD-CT with IR and 117 underwent ULD-CT with IR. The patients were divided according to their body mass index (BMI) into BMI1 (<22.9 kg/m{sup 2}), BMI2 (23.0-24.9 kg/m{sup 2}), and BMI3 (≥25 kg/m{sup 2}) groups. Two blinded radiologists independently evaluated the signal-to-noise ratio (SNR), qualitative image quality, and final diagnoses (lumbar disc disease and facet joint osteoarthritis). L-spine MRIs interpreted by consensus were used as the reference standard. All data were statistically analyzed. ULD protocol showed significantly lower SNR for all patients (p < 0.001) except the vertebral bodies and lower qualitative image quality for BMI3 patients (p ≤ 0.033). There was no statistically significant difference between ULD (sensitivity, 95.1-98.1%; specificity, 92.5-98.7%; accuracy, 94.6-98.0%) and LD protocols (sensitivity, 95.6-100%; specificity, 95.5-98.9%; accuracy, 97.4-98.1%), (all p≥0.1) in the BMI1 and BMI2; while dose was 60-68% lower with the ULD protocol. Interobserver agreements were excellent or good with regard to image quality and final diagnoses. For the BM1 and BMI2 groups, ULD-CT provided an acceptable image quality and exhibited a diagnostic accuracy similar to that of LD-CT. These findings suggest that it is a useful diagnostic tool for patients with chronic LBP who exhibit a BMI of <25 kg/m{sup 2}. (orig.)

  11. Diagnostic accuracy of low-dose versus ultra-low-dose CT for lumbar disc disease and facet joint osteoarthritis in patients with low back pain with MRI correlation

    International Nuclear Information System (INIS)

    Lee, Sun Hwa; Yun, Seong Jong; Jo, Hyeon Hwan; Kim, Dong Hyeon; Song, Jae Gwang; Park, Yong Sung

    2018-01-01

    To compare the image quality, radiation dose, and diagnostic performance between low-dose (LD) and ultra-low-dose (ULD) lumbar-spine (L-spine) CT with iterative reconstruction (IR) for patients with chronic low back pain (LBP). In total, 260 patients with chronic LBP who underwent L-spine CT between November 2015 and September 2016 were prospectively enrolled. Of these, 143 underwent LD-CT with IR and 117 underwent ULD-CT with IR. The patients were divided according to their body mass index (BMI) into BMI1 (<22.9 kg/m 2 ), BMI2 (23.0-24.9 kg/m 2 ), and BMI3 (≥25 kg/m 2 ) groups. Two blinded radiologists independently evaluated the signal-to-noise ratio (SNR), qualitative image quality, and final diagnoses (lumbar disc disease and facet joint osteoarthritis). L-spine MRIs interpreted by consensus were used as the reference standard. All data were statistically analyzed. ULD protocol showed significantly lower SNR for all patients (p < 0.001) except the vertebral bodies and lower qualitative image quality for BMI3 patients (p ≤ 0.033). There was no statistically significant difference between ULD (sensitivity, 95.1-98.1%; specificity, 92.5-98.7%; accuracy, 94.6-98.0%) and LD protocols (sensitivity, 95.6-100%; specificity, 95.5-98.9%; accuracy, 97.4-98.1%), (all p≥0.1) in the BMI1 and BMI2; while dose was 60-68% lower with the ULD protocol. Interobserver agreements were excellent or good with regard to image quality and final diagnoses. For the BM1 and BMI2 groups, ULD-CT provided an acceptable image quality and exhibited a diagnostic accuracy similar to that of LD-CT. These findings suggest that it is a useful diagnostic tool for patients with chronic LBP who exhibit a BMI of <25 kg/m 2 . (orig.)

  12. Non-contrast CT at comparable dose to an abdominal radiograph in patients with acute renal colic; impact of iterative reconstruction on image quality and diagnostic performance

    OpenAIRE

    McLaughlin, P. D.; Murphy, K. P.; Hayes, S. A.; Carey, K.; Sammon, J.; Crush, L.; O’Neill, F.; Normoyle, B.; McGarrigle, A. M.; Barry, J. E.; Maher, M. M.

    2014-01-01

    Objectives The aim was to assess the performance of low-dose non-contrast CT of the urinary tract (LD-CT) acquired at radiation exposures close to that of abdominal radiography using adaptive statistical iterative reconstruction (ASiR). Methods Thirty-three patients with clinically suspected renal colic were prospectively included. Conventional dose (CD-CT) and LD-CT data sets were contemporaneously acquired. LD-CT images were reconstructed with 40 %, 70 % and 90 % ASiR. Image quality was sub...

  13. Mosquitocidal Activity and Mode of Action of the Isoxazoline Fluralaner

    Directory of Open Access Journals (Sweden)

    Shiyao Jiang

    2017-02-01

    Full Text Available Mosquitoes, such as Aedes aegypti and Anopheles gambiae, are important vectors of human diseases. Fluralaner, a recently introduced parasiticide, was evaluated as a mosquitocide in this study. On Ae. aegypti and An. gambiae fourth-instar larvae, fluralaner had 24-h LC50 (lethal concentration for 50% mortality values of 1.8 ppb and 0.4 ppb, respectively. Following topical application to adult Ae. aegypti, fluralaner toxicity reached a plateau in about 3 days, with 1- and 3-day LD50 (lethal dose for 50% mortality values of 1.3 ng/mg and 0.26 ng/mg, suggesting a slowly developing toxicity. Fipronil outperformed fluralaner by up to 100-fold in adult topical, glass contact, and feeding assays on Ae. aegypti. These data show that fluralaner does not have exceptional toxicity to mosquitoes in typical exposure paradigms. In electrophysiological recordings on Drosophila melanogaster larval central nervous system, the effectiveness of fluralaner for restoring nerve firing after gamma-aminobutyric acid (GABA treatment, a measure of GABA antagonism, was similar in susceptible Oregon-R and cyclodiene-resistant rdl-1675 strains, with EC50 (half maximal effective concentration values of 0.34 µM and 0.29 µM. Although this finding suggests low cross resistance in the presence of rdl, the moderate potency, low contact activity, and slow action of fluralaner argue against its use as an adult mosquitocide for vector control.

  14. On the mutagenicity of methadone hydrochloride. Induced dominant lethal mutation and spermatocyte chromosomal aberrations in treated males.

    Science.gov (United States)

    Badr, F M; Rabouh, S A; Badr, R S

    1979-11-01

    The mutagenicity of methadone hydrochloride was tested in male mice using the dominant lethal mutation technique and the spermatocyte test of treated mice. Male mice of C3H inbred strain received one of the following doses, 1, 2, 4 or 6 mg/kg body weight once a day for 3 consecutive days. Another group of mice served as control and received saline instead. Treated males were then mated to virgin females at 3-day intervals for a period of 45 days. Pregnant females were dissected at mid-term and the corpora lutea and intrauterine contents were recorded. The spermatocytes of treated males were examined 45-50 d after treatments with methadone and abnormal pairing configurations were scored. The methadone treatment was found to increase the rate of preimplantation deaths consistently in all post-meiotic stages with all doses used. In addition, the higher doses, 4 and 6 mg, affected spermatogonia stages. Quantitatively, the dose-response relationship cannot be demonstrated though the spectrum of effect increased with higher doses as more spermatogenesis stages became more sensitive to the treatment. In many cases the frequency of live implants showed a positive correlation with preimplantation deaths in contrast with the frequency of early deaths which showed only sporadic variation. The mutation indices based on total embryonic death indicate that methadone hydrochloride affected several stages of germ-cell maturation namely, spermatozoa (M.I. 14-35), late spermatids (M.I. 15-48), early spermatids (M.I. 14-50), late spermatocytes (M.I. 15-43) and spermatogonial stages (M.I. 12-63). Chromosome analysis at diakinesis-metaphase 1 revealed significant increase in the frequency of sex chromosome and autosome univalents with different doses of methadone. The smallest dose applied was quite effective and the data represent direct dose-response relationship. Of the multivalent configuration, the most frequent type was chain quadrivalents. The frequencies of total translocations

  15. Impact of acute alcohol consumption on lethality of suicide methods.

    Science.gov (United States)

    Park, C Hyung Keun; Yoo, Seong Ho; Lee, Jaewon; Cho, Sung Joon; Shin, Min-Sup; Kim, Eun Young; Kim, Se Hyun; Ham, Keunsoo; Ahn, Yong Min

    2017-05-01

    The influence of acute alcohol consumption on the factors related to suicide remains understudied. Thus, the present study investigated the relationship between blood alcohol content (BAC) and the lethality of suicide methods. Autopsy data on 315 South Korean suicide completers with a positive BAC were collected from a nationwide pool between May 2015 and November 2015, and the methods were dichotomised as suicide methods of low lethality (SMLL; drug/chemical overdose and sharp objects, n=67) and suicide methods of high lethality (SMHL; everything else, n=243). BAC at the time of autopsy and various suicide-related factors of these two groups were compared with logistic regression analyses. Compared to suicide completers with a BAC in the lowest range of 0.011-0.049%, suicide completers with a BAC in the range of 0.150-0.199% were more likely to use SMHL (odds ratio [OR]: 3.644, 95% confidence interval [CI]: 1.221-10.874). Additionally, the adoption of SMHL was significantly associated with the absence of a psychiatric illness (OR: 0.433, 95% CI: 0.222-0.843) and a younger age; the OR for high BAC among subjects in their 40s was 0.266 (95% CI: 0.083-0.856); in their 50s, 0.183 (95% CI: 0.055-0.615); and in their 60s, 0.057 (95% CI: 0.015-0.216). The relationship between BAC and suicide method lethality was represented by a bell-shaped pattern in which suicide methods of high lethality were more likely to be used by suicide completers with mid-range BAC levels. The increased impulsivity and impairments in particular executive functions, including planning and organization, associated with acute alcohol use may influence the selection of a particular suicide method based on its lethality. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Ida-Virumaa ettevõtete TOP 50

    Index Scriptorium Estoniae

    2005-01-01

    Ilmunud ka: Delovõje Vedomosti-Severo-Vostok 7. sept. lk. 4. Ida-Virumaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Ida-Virumaa ettevõtete üld- ja finantsandmed

  17. The Effect of A Single Sub-Lethal Dose of Whole Body Irradiation on the Small Intestine of Rats

    International Nuclear Information System (INIS)

    Al-Ramli, M. A.; Kubba, M. A.; Al-Bassam, L. S.; Belhaj, K.; Al-shawish, N. M.

    2007-01-01

    The effect of whole body radiation with a single sub-lethal dose at 4 Gy on rat small intestine was studied histologically and quantitatively. Irradiated animals were euthanized at 24 hours, 3, 7, 14, 21 and 28 days post- irradiation. Crypts of Leiberkuhn and peyer's patches were especially targeted by irradiation. The crypts showed severe cellular fragmentation in the germinal cellular compartments twenty Four hours after irradiation resulting in partial denudation of villi especially at their Tips. At three days, these cells resumed their proliferative activity with the appearance of unusually large numbers of mitotic figures. Cellular regeneration in the crypts and on the villous surface showed improvement with advancing time till day 28 when the villi had complete epithelial covering and the proliferative activity of the germinal cryptic cells returned to normal. The quantitative study included the measurement of about fifty villi at each time after irradiation. A significant decrease in villous length was noticed at twenty four hours post-irradiation compared to the control values. The length of villi plateaued at about this level till day twenty one when it slightly increased to reach a sub normal mean length on day 28. We concluded that whole body irradiation with a single dose at 4 Gy was enough to induce cryptic cellular necrosis with sloughing of epithelial villous columnar covering. This cellular damage was, however, sub- total since quick regenerative cellular activity was noticed three days post-irradiation. The decrease in the villous length paralleled the cryptic cellular damage whereas full recovery was not achieved despite obvious cellular regeneration.

  18. High-power and highly reliable 638-nm band BA-LD for CW operation

    Science.gov (United States)

    Nishida, Takehiro; Kuramoto, Kyosuke; Abe, Shinji; Kusunoki, Masatsugu; Miyashita, Motoharu; Yagi, Tetsuya

    2018-02-01

    High-power laser diodes (LDs) are strongly demanded as light sources of display applications. In multiple spatial light modulator-type projectors or liquid crystal displays, the light source LDs are operated under CW condition. The high-power 638-nm band broad-area LD for CW operation was newly developed. The LD consisted of two stripes with each width of 75 μm to reduce both an optical power density at a front facet and a threshold current. The newly improved epitaxial technology was also applied to the LD to suppress an electron overflow from an active layer. The LD showed superior output characteristics, such as output of 1.77 W at case temperature of 55 °C with wall plug efficiency (WPE) of 23%, which was improved by 40% compared with the current product. The peak WPE at 25 °C reached 40.6% under the output power of 2.37 W, CW, world highest.

  19. Mutagenic effects of carbon ion beam irradiations on dry Lotus japonicus seeds

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shanwei [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou, Libin, E-mail: libinzhou@impcas.ac.cn [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Li, Wenjian; Du, Yan [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); Yu, Lixia; Feng, Hui; Mu, Jinhu [Biophysics Group, Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Road, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Yuze [College of Life Science and Technology, Gansu Agricultural University, No. 1 Yingmen Village, Anning District, Lanzhou, Gansu Province 730070 (China)

    2016-09-15

    Carbon ion beam irradiation is a powerful method for creating mutants and has been used in crop breeding more and more. To investigate the effects of carbon ion beams on Lotus japonicus, dry seeds were irradiated by 80 MeV/u carbon ion beam at dosages of 0, 100, 200, 300, 400, 500 and 600 Gy. The germination rate, survival rate and root length of M{sub 1} populations were explored and the dose of 400 Gy was selected as the median lethal dose (LD{sub 50}) for a large-scale mutant screening. Among 2472 M{sub 2} plants, 127 morphological mutants including leaf, stem, flower and fruit phenotypic variation were found, and the mutation frequency was approximately 5.14%. Inter simple sequence repeat (ISSR) assays were utilized to investigate the DNA polymorphism between seven mutants and eight plants without phenotypic variation from M{sub 2} populations. No remarkable differences were detected between these two groups, and the total polymorphic rate was 0.567%.

  20. The effect of gamma radiation on the rice moth, Corcyra Cephalonica (Staint). Part II irradiation of the eggs, pupae, and adults

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, S; Sutantawong, M; Ungsunanatwiwat, A

    1972-12-31

    The 1-3 days old eggs of the rice moth were exposed to gamma rays at 0, 3, 6, 12.5 and 25 krads. The LD{sub 50} and LD{sub 99} for eggs was estimated as 9 and 42 krads respectively. A dose of 25 krads caused 100% mortality in larvae irradiated as egg stage. Mixed ages of 1-7 days old pupae were subjected to 0, 6, 12.5, 25, 50 and 100 Krads of gamma rays. Based on number of adults emerged, the LD{sub 50} and LD{sub 99} for pupae were estimated as 19 and 110 krads. Mixed sexes of 1-3 days old adult moths were also exposed to gamma rays. The LD{sub 50} and LD{sub 99} for adults appeared to be 60 and 170 krads respectively. Irradiation of both sexes of adult moths at 25 and 50 krads, led to complete infertility in eggs deposited.