In vitro cell culture lethal dose submitted to gamma radiation

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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)

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)

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

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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.

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

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.

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

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)

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

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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.

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.

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

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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.

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.

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

Effect of single dose, fractionated, and hyperfractionated trunk irradiation on weight gain, respiration frequency, and survival in rats

International Nuclear Information System (INIS)

Kimler, B.F.; Giri, P.G.S.; Giri, U.P.; Cox, G.G.

1986-01-01

It is concluded that, in this rat trunk irradiation model, fractionation of a single dose into two equal doses separated by 4-6 h produced a sparing effect of approx. 5Gy as measured by delay in weight gain; approx. 4Gy as measured by increased respiration frequency; and approx. 6Gy as measured by survival. Fractionation into daily doses or hyperfractionation into twice-daily doses permitted an approximate doubling of the dose required for the same suppression of weight gain. For the respiration rates and survival endpoints, fractionation or hyperfractionation produced an even greater sparing effect since there was no increase in the respiration frequency at twice the doses that would produce changes if delivered within a few hours; and since essentially no lethality was observed at twice the doses that would kill 70%-100% of animals if delivered in one day. (UK)

Novel Insect-Specific Eilat Virus-Based Chimeric Vaccine Candidates Provide Durable, Mono- and Multivalent, Single-Dose Protection against Lethal Alphavirus Challenge.

Science.gov (United States)

Erasmus, Jesse H; Seymour, Robert L; Kaelber, Jason T; Kim, Dal Y; Leal, Grace; Sherman, Michael B; Frolov, Ilya; Chiu, Wah; Weaver, Scott C; Nasar, Farooq

2018-02-15

Most alphaviruses are mosquito borne and exhibit a broad host range, infecting many different vertebrates, including birds, rodents, equids, humans, and nonhuman primates. Recently, a host-restricted, mosquito-borne alphavirus, Eilat virus (EILV), was described with an inability to infect vertebrate cells based on defective attachment and/or entry, as well as a lack of genomic RNA replication. We investigated the utilization of EILV recombinant technology as a vaccine platform against eastern (EEEV) and Venezuelan equine encephalitis viruses (VEEV), two important pathogens of humans and domesticated animals. EILV chimeras containing structural proteins of EEEV or VEEV were engineered and successfully rescued in Aedes albopictus cells. Cryo-electron microscopy reconstructions at 8 and 11 Å of EILV/VEEV and EILV/EEEV, respectively, showed virion and glycoprotein spike structures similar to those of VEEV-TC83 and other alphaviruses. The chimeras were unable to replicate in vertebrate cell lines or in brains of newborn mice when injected intracranially. Histopathologic examinations of the brain tissues showed no evidence of pathological lesions and were indistinguishable from those of mock-infected animals. A single-dose immunization of either monovalent or multivalent EILV chimera(s) generated neutralizing antibody responses and protected animals against lethal challenge 70 days later. Lastly, a single dose of monovalent EILV chimeras generated protective responses as early as day 1 postvaccination and partial or complete protection by day 6. These data demonstrate the safety, immunogenicity, and efficacy of novel insect-specific EILV-based chimeras as potential EEEV and VEEV vaccines. IMPORTANCE Mostly in the last decade, insect-specific viruses have been discovered in several arbovirus families. However, most of these viruses are not well studied and largely have been ignored. We explored the use of the mosquito-specific alphavirus EILV as an alphavirus vaccine

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)

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

Antimalarial iron chelator, FBS0701, shows asexual and gametocyte Plasmodium falciparum activity and single oral dose cure in a murine malaria model.

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Patricia Ferrer

Full Text Available Iron chelators for the treatment of malaria have proven therapeutic activity in vitro and in vivo in both humans and mice, but their clinical use is limited by the unsuitable absorption and pharmacokinetic properties of the few available iron chelators. FBS0701, (S3"-(HO-desazadesferrithiocin-polyether [DADFT-PE], is an oral iron chelator currently in Phase 2 human studies for the treatment of transfusional iron overload. The drug has very favorable absorption and pharmacokinetic properties allowing for once-daily use to deplete circulating free iron with human plasma concentrations in the high µM range. Here we show that FBS0701 has inhibition concentration 50% (IC(50 of 6 µM for Plasmodium falciparum in contrast to the IC(50 for deferiprone and deferoxamine at 15 and 30 µM respectively. In combination, FBS0701 interfered with artemisinin parasite inhibition and was additive with chloroquine or quinine parasite inhibition. FBS0701 killed early stage P. falciparum gametocytes. In the P. berghei Thompson suppression test, a single dose of 100 mg/kg reduced day three parasitemia and prolonged survival, but did not cure mice. Treatment with a single oral dose of 100 mg/kg one day after infection with 10 million lethal P. yoelii 17XL cured all the mice. Pretreatment of mice with a single oral dose of FBS0701 seven days or one day before resulted in the cure of some mice. Plasma exposures and other pharmacokinetics parameters in mice of the 100 mg/kg dose are similar to a 3 mg/kg dose in humans. In conclusion, FBS0701 demonstrates a single oral dose cure of the lethal P. yoelii model. Significantly, this effect persists after the chelator has cleared from plasma. FBS0701 was demonstrated to remove labile iron from erythrocytes as well as enter erythrocytes to chelate iron. FBS0701 may find clinically utility as monotherapy, a malarial prophylactic or, more likely, in combination with other antimalarials.

Comparison of single, fractionated and hyperfractionated irradiation on the development of normal tissue damage in rat lung

International Nuclear Information System (INIS)

Giri, P.G.S.; Kimler, B.F.; Giri, U.P.; Cox, G.G.; Reddy, E.K.

1985-01-01

The effect of fractionated thoracic irradiation on the development of normal tissue damage in rats was compared to that produced by single doses. Animals received a single dose of 15 Gy, 30 Gy in 10 daily fractions of 3 Gy each (fractionation), or 30 Gy in 30 fractions of 1 Gy each 3 times a day (hyperfractionation). The treatments produced minimal lethality since a total of only 6 animals died between days 273 and 475 after the initiation of treatment, with no difference in survival observed between the control and any of the 3 treated groups. Despite the lack of lethality, evidence of lung damage was obtained by histological examination. Animals that had received either single doses or fractionated doses had more of the pulmonary parenchyma involved than did animals that had received hyperfractionated doses. The authors conclude that, in the rat lung model, a total radiation dose of 30 Gy fractionated over 14 days produces no more lethality nor damage to lung tissue than does 15 Gy delivered as a single dose. However, long-term effects as evidenced by deposits of collagen and development of fibrosis are significantly reduced by hyperfractionation when compared to single doses and daily fractionation

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

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

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.

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

Single-dose Intramuscular-injection Toxicology Test of Water-soluble Carthami-flos and Cervi cornu parvum Pharmacopuncture in a Rat Model

Directory of Open Access Journals (Sweden)

Sunju Park

2015-09-01

Full Text Available Objectives: The aim of the study is to investigate both the single-dose intramuscular injection toxicity and the approximate lethal dose of water-soluble Carthami-flos and Cervi cornu parvum pharmacopuncture (WCFC in male and female Sprague-Dawley (SD rats. Methods: The study was conducted at Biotoxtech Co. according to the Good Laboratory Practice (GLP regulation and the toxicity test guidelines of the Ministry of Food and Drug Safety (MFDS after approval of the Institutional Animal Care and Use Committee. Dosages for the control, high dose, middle dose and low dose groups were 0.5 mL/animal of saline and 0.5, 0.25 and 0.125 mL/animal of WCFC, respectively. WCFC was injected into the muscle of the left femoral region by using a disposable syringe (1 mL, 26 gauge. The general symptoms and mortality were observed 30 minutes, 1, 2, 4, and 6 hours after the first injection and then daily for 14 days after the injection. The body weights of the SD rats were measured on the day of the injection (before injection and on the third, seventh, and fourteenth days after the injection. Serum biochemical and hematologic tests, necropsy examinations, and histopathologic examinations at the injection site were performed after the observation period. Results: No deaths, abnormal clinical symptoms, or significant weight changes were observed in either male or female SD rats in the control or the test (0.125, 0.25, and 0.5 mL/animal groups during the observation period. No significant differences in hematology and serum biochemistry and no macroscopic abnormalities at necropsy were found. No abnormal reactions at injection sites were noted on the topical tolerance tests. Conclusion: The results of this single-dose toxicity study show that WCFC is safe, its lethal doses in male and female SD rats being estimated to be higher than 0.5 mL/animal.

Residual toxicity in hematopoietic cells following a single dose of methylnitrosourea

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Inoue, T.; Cronkite, E.P.; Commerford, S.L.; Carsten, A.L.

1984-01-01

The residual injury to the proliferation capability of hemopoietic stem cells (CFU-S) which results from their exposure to leukemogenic agents was evaluated in mice given a single leukemogenic dose of methol nitrosourea. Bone marrow cellularity, splenic weight, number of CFU-S and the proportion of cycling to noncycling CFU-S were measured in an effort to detect acute and residual injury to the CFU-S from mice given MNU 21 and 3 days earlier. Marrow cells were also transferred into lethally irradiated mice to observe the self-renewal capability of the CFU-S in the recipient spleen and bone marrow. The results of these measurements show that the CFU-S in marrow from mice given 50 mg/kg of MNU 21 days earlier still have a defective ability for self-renewal, although the total cellularity, number of CFU-S and proportion of cycling and noncycling CFU-S in the donor have returned to the normal range. The relationship of this self-renewal defect to the development of leukemia after this leukemogenic dose of MNU is not known. 21 references, 9 figures, 3 tables.

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

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.

Effect of mutagen combined action on Chlamydomonas reinhardtii cells. II. Dependence of lethal effect on mutagen dose and on conditions of cultivation following mutagen action. [In Slovak

Energy Technology Data Exchange (ETDEWEB)

Podstavkova, S; Vlcek, D; Dubovsky, J [Komenskeho Univ., Bratislava (Czechoslovakia). Prirodovedecka Fakulta

1978-01-01

The effect of UV radiation and UV radiation combined with alkylnitrosourea derivatives (N-methyl-N-nitrosourea and N-ethyl-N-nitrosourea) was observed on survival of cells of the algae Chlamydomonas reinhardtii. In particular, single parts were evaluated of the overall lethal effect - dying of cells before division and dying of cells after division. It was found that the combined action of low doses of UV radiation and alkylnitrosoureas result in a pronounced protective effect which manifests itself by a higher frequency of surviving cells than was that effected by the action of alkylnitrosoureas alone. As a result of combined action with higher doses of UV radiation this effect is lost, and the resultant values will come close to the theoretically anticipated values. This gradual transition from a protective to an additive effect mainly manifests itself by changes in the proportion of cells dying before division.

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.

A Pilot Study on Single-dose Toxicity Testing of Scolopendrid Pharmacopuncture in Sprague-Dawley Rats

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Ilhong Son

2014-06-01

Full Text Available Objectives:This study was performed to analyze single dose toxicity and the lethal dose of Scolopendrid Pharmacopuncture in rats. Methods:All experiments were conducted at the Korea Testing & Research Institute (KTR, an institution authorized to perform non-clinical studies, under the regulations of Good Laboratory Practice (GLP. Sprague-Dawley rats were chosen for the pilot study. Doses of Scolopendrid pharmacopuncture, 0.1, 0.5, and 1.0 mL, were administered to the experimental group, and 1.0 mL doses of normal saline solution were administered to the control group. This study was conducted under the approval of the Institutional Animal Ethic Committee. Results:No deaths or abnormalities occurred in any of the groups. No significant changes in the weight, hematological parameters or clinical chemistry were noted between the control group and the experimental group. To check for abnormalities in organs and tissues, we used microscopy to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs or tissues. Conclusion:The above findings suggest Scolopendrid Pharmacopuncture is a relatively safe to use for treatment. Further studies on the subject should be conducted to yield more concrete evidence.

Synthetic lethality between gene defects affecting a single non-essential molecular pathway with reversible steps.

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Andrei Zinovyev

2013-04-01

Full Text Available Systematic analysis of synthetic lethality (SL constitutes a critical tool for systems biology to decipher molecular pathways. The most accepted mechanistic explanation of SL is that the two genes function in parallel, mutually compensatory pathways, known as between-pathway SL. However, recent genome-wide analyses in yeast identified a significant number of within-pathway negative genetic interactions. The molecular mechanisms leading to within-pathway SL are not fully understood. Here, we propose a novel mechanism leading to within-pathway SL involving two genes functioning in a single non-essential pathway. This type of SL termed within-reversible-pathway SL involves reversible pathway steps, catalyzed by different enzymes in the forward and backward directions, and kinetic trapping of a potentially toxic intermediate. Experimental data with recombinational DNA repair genes validate the concept. Mathematical modeling recapitulates the possibility of kinetic trapping and revealed the potential contributions of synthetic, dosage-lethal interactions in such a genetic system as well as the possibility of within-pathway positive masking interactions. Analysis of yeast gene interaction and pathway data suggests broad applicability of this novel concept. These observations extend the canonical interpretation of synthetic-lethal or synthetic-sick interactions with direct implications to reconstruct molecular pathways and improve therapeutic approaches to diseases such as cancer.

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

Vaxchora: A Single-Dose Oral Cholera Vaccine.

Science.gov (United States)

Cabrera, Adriana; Lepage, Jayne E; Sullivan, Karyn M; Seed, Sheila M

2017-07-01

To review trials evaluating the efficacy and safety of Vaxchora, a reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine for the prevention of travel-related cholera caused by V cholerae serogroup O1. A literature search was conducted using MEDLINE (1946 to January week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical trials published in English since 2010. ClinicalTrials.gov was used as a source for unpublished data. Additional data sources were obtained through bibliographic review of selected articles. Studies that addressed the safety and efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera vaccine, were selected for analysis. Approval of Vaxchora, was based on efficacy of the vaccine in human trials demonstrating 90.3% protection among those challenged with V cholerae 10 days after vaccination and in immunogenicity studies with 90% systemic vibriocidal antibody conversion at 6 months after a single-dose of vaccine. Tolerability was acceptable, with the most common adverse effects reported to be fatigue, headache, and abdominal pain. Vaxchora is the only FDA-approved, single-dose oral vaccine for the prevention of cholera caused by V cholerae serogroup O1 in adult travelers from the United States going to cholera-affected areas. Safety and efficacy has not been established in children, immunocompromised persons, and pregnant or breastfeeding women or those living in cholera-endemic areas.

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)

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

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

Gluconeogenesis in lethally X-irradiated rats

International Nuclear Information System (INIS)

Paulikova, E.; Ahlers, I.; Praslicka, M.

1983-01-01

The in vivo incorporation of U- 14 C-alanine into blood glucose and liver glycogen was measured in rats irradiated with a single whole body lethal dose of X-rays. Changes in gluconeogenic enzyme activities were studied in the liver. Increased incorporation of 14 C-alanine into blood glucose and liver glycogen were found after irradiation. Liver phosphoenolpyruvate carboxykinase and glycogenic activity underwent almost parallel changes and were significantly elevated from the 6th to the 48th hour, with resultant accumulation of glycogen. Glucose-6-phosphatase activity was depressed and there was a negative correlation between it and liver glycogen concentration. Maximum fructose-1,6-diphosphatase activity was found at 48 hours. The results show that glycogen accumulation in the liver and the raised blood glucose level in X-irradiated rats are based on raised gluconeogenesis. (author)

Gluconeogenesis in lethally X-irradiated rats

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Paulikova, E.; Ahlers, I.; Praslicka, M. (Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie)

1983-02-01

The in vivo incorporation of U-/sup 14/C-alanine into blood glucose and liver glycogen was measured in rats irradiated with a single whole body lethal dose of X-rays. Changes in gluconeogenic enzyme activities were studied in the liver. Increased incorporation of /sup 14/C-alanine into blood glucose and liver glycogen were found after irradiation. Liver phosphoenolpyruvate carboxykinase and glycogenic activity underwent almost parallel changes and were significantly elevated from the 6th to the 48th hour, with resultant accumulation of glycogen. Glucose-6-phosphatase activity was depressed and there was a negative correlation between it and liver glycogen concentration. Maximum fructose-1,6-diphosphatase activity was found at 48 hours. The results show that glycogen accumulation in the liver and the raised blood glucose level in X-irradiated rats are based on raised gluconeogenesis.

Tolerance of the human spinal cord to single dose radiosurgery

International Nuclear Information System (INIS)

Ryu, S.; Zhu, G.; Yin, F.-F.; Ajlouni, M.; Kim, J.H.

2003-01-01

Tolerance of the spinal cord to the single dose of radiation is not well defined. Although there are cases of human spinal cord tolerance from re-irradiation to the same cord level, the information about the tolerance of human spinal cord to single large dose of radiosurgery is not available. We carried out spinal radiosurgery to treat spinal metastasis and studied the single dose tolerance of the human spinal cord in an ongoing dose escalation paradigm. A total of 39 patients with 48 lesions of spinal metastasis were treated with single dose radiosurgery at Henry Ford Hospital. The radiosurgery dose was escalated from 8 Gy to 16 Gy at 2 Gy increment. The radiation dose was prescribed to periphery of the spinal tumor. The radiation dose to the spinal cord was estimated by computerized dosimetry. The median follow-up time was 10 months (range 6-18 months) from the radiosurgery. The endpoint of the study was to demonstrate the efficacy of the spinal radiosurgery and to determine the tolerance of human spinal cord to single dose radiosurgery. The dose to the spinal cord was generally less than 50 % of the prescribed radiation dose. The volume of the spinal cord that received higher than this dose was less than 20 % of the anterior portion of the spinal cord. Maximum single dose of 8 Gy was delivered to the anterior 20 % of the spinal cord in this dose escalation study. The dose volume histogram will be presented. There was no acute or subacute radiation toxicity detected clinically and radiologically during the maximum follow-up of 20 months. Further dose escalation is in progress. The single tolerance dose of the human spinal cord appears to be at least 8 Gy when it was given to the 20 % of the cord volume, although the duration of follow up is not long enough to detect severe late cord toxicity. This study offers a valuable radiobiological basis of the normal spinal cord tolerance, and opens spinal radiosurgery as a safe treatment for spinal metastasis

Metabolic changes after non-lethal X-irradiation of rats. I

International Nuclear Information System (INIS)

Ahlersova, E.; Ahlers, I.; Slavkovska, E.; Praslicka, M.

1981-01-01

Male rats of the Wistar strain were fasted overnight prior to exposure to single whole-body X-ray dose of 2.39 Gy (250 R). Irradiated and sham-irradiated rats were pair-fed for 5 days, in the following period they were fed ad libitum. The levels of corticosterone and immunoreactive insulin in serum, glucose in blood, glycogen in liver, heart and skeletal muscle were determined 1 and 6 h, 1, 2, 3, 7, 14, 21, 28, and 38 days after irradiation and sham-irradiation. Irradiation of rats resulted, in one hour, in a decrease and, in two days, in an increase in blood glucose level. A marked increase in liver glycogen persisted from 6 h to 21 days after irradiation. The level of glycogen in the skeletal muscle was reduced after 6 h and increased on days 3 and 14. Heart muscle glycogen declined within the first 24 h and rose at 14 days after exposure. The kinetics of changes in the heart and skeletal muscle glycogen following non-lethal irradiation was similar and indicated an overlap of changes produced by fasting with those brought about by irradiation, particularly during the first week. Corticosterone in serum was markedly increased in rats 24 and 72 h after irradiation compared to pair-fed controls. The serum insulin concentration did not change after irradiation, except for a single increase on day 21. Irradiation with non-lethal doses produced changes in the parameters of the carbohydrate metabolism studied, except for serum insulin which reflected the changes in the nutrition regimen upon pair-feeding rather than the effect of ionizing irradiation. (author)

Single-dose ceftriaxone for chancroid.

Science.gov (United States)

Bowmer, M I; Nsanze, H; D'Costa, L J; Dylewski, J; Fransen, L; Piot, P; Ronald, A R

1987-01-01

Men with genital ulcers that were culture positive for Haemophilus ducreyi were treated with intramuscular ceftriaxone and randomized to three different dose regimens. All but 1 of 50 men treated with 1 g of intramuscular ceftriaxone were cured. Similarly, 0.5 and 0.25 g cured 43 of 44 men and 37 of 38 men, respectively. A single dose of 250 mg of intramuscular ceftriaxone is an effective treatment for chancroid. PMID:3566241

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)

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)

Measurement of the equivalent dose in quartz using a regenerative-dose single-aliquot protocol

International Nuclear Information System (INIS)

Murray, A.S.; Roberts, R.G.

1998-01-01

The principles behind a regenerative-dose single-aliquot protocol are outlined. It is shown for three laboratory-bleached Australian sedimentary quartz samples that the relative change in sensitivity of the optically stimulated luminescence (OSL) during a repeated measurement cycle (consisting of a dose followed by a 10 s preheat at a given temperature and then a 100 s exposure to blue/green light at 125 deg. C) is very similar to that of the 110 deg. C thermoluminescence (TL) peak measured during the preheat cycle. The absolute change in the TL sensitivity with preheat temperature is different for samples containing a natural or a regenerative dose. Furthermore, the absolute change in sensitivity in both the OSL and TL signals is non-linear with regeneration cycle, but the relative change in the OSL signal compared to the following 110 deg. C TL measurement is well approximated by a straight line. Both signals are thought to use the same luminescence centres, and so some common behaviour is not unexpected. A new regenerative-dose protocol is presented which makes use of this linear relationship to correct for sensitivity changes with regeneration cycle, and requires only one aliquot for the estimation of the equivalent dose (D e ). The protocol has been applied to quartz from nine Australian sites. To illustrate the value of the regenerative-dose single-aliquot approach, the apparent values of D e for 13 samples, containing doses of between 0.01 and 100 Gy, have been measured at various preheat temperatures of between 160 and 300 deg. C, using a single aliquot for each D e measurement. Excellent agreement is found between these single-aliquot estimates of D e and those obtained from additive-dose multiple-aliquot and single-aliquot protocols, over the entire dose range

A single-aliquot OSL protocol using bracketing regenerative doses to accurately determine equivalent doses in quartz

CERN Document Server

Folz, E

1999-01-01

In most cases, sediments show inherent heterogeneity in their luminescence behaviours and bleaching histories, and identical aliquots are not available: single-aliquot determination of the equivalent dose (ED) is then the approach of choice and the advantages of using regenerative protocols are outlined. Experiments on five laboratory bleached and dosed quartz samples, following the protocol described by Murray and Roberts (1998. Measurement of the equivalent dose in quartz using a regenerative-dose single aliquot protocol. Radiation Measurements 27, 171-184), showed the hazards of using a single regeneration dose: a 10% variation in the regenerative dose yielded some equivalent dose estimates that differed from the expected value by more than 5%. A protocol is proposed that allows the use of different regenerative doses to bracket the estimated equivalent dose. The measured ED is found to be in excellent agreement with the known value when the main regeneration dose is within 10% of the true equivalent dose.

A single-aliquot OSL protocol using bracketing regenerative doses to accurately determine equivalent doses in quartz

International Nuclear Information System (INIS)

Folz, Elise; Mercier, Norbert

1999-01-01

In most cases, sediments show inherent heterogeneity in their luminescence behaviours and bleaching histories, and identical aliquots are not available: single-aliquot determination of the equivalent dose (ED) is then the approach of choice and the advantages of using regenerative protocols are outlined. Experiments on five laboratory bleached and dosed quartz samples, following the protocol described by Murray and Roberts (1998. Measurement of the equivalent dose in quartz using a regenerative-dose single aliquot protocol. Radiation Measurements 27, 171-184), showed the hazards of using a single regeneration dose: a 10% variation in the regenerative dose yielded some equivalent dose estimates that differed from the expected value by more than 5%. A protocol is proposed that allows the use of different regenerative doses to bracket the estimated equivalent dose. The measured ED is found to be in excellent agreement with the known value when the main regeneration dose is within 10% of the true equivalent dose

Single-Dose Lignocaine-Based Blood Cardioplegia in Single Valve Replacement Patients

Directory of Open Access Journals (Sweden)

Jaydip Ramani

Full Text Available Abstract OBJECTIVE: Myocardial protection is the most important in cardiac surgery. We compared our modified single-dose long-acting lignocaine-based blood cardioplegia with short-acting St Thomas 1 blood cardioplegia in patients undergoing single valve replacement. METHODS: A total of 110 patients who underwent single (aortic or mitral valve replacement surgery were enrolled. Patients were divided in two groups based on the cardioplegia solution used. In group 1 (56 patients, long-acting lignocaine based-blood cardioplegia solution was administered as a single dose while in group 2 (54 patients, standard St Thomas IB (short-acting blood-based cardioplegia solution was administered and repeated every 20 minutes. All the patients were compared for preoperative baseline parameters, intraoperative and all the postoperative parameters. RESULTS: We did not find any statistically significant difference in preoperative baseline parameters. Cardiopulmonary bypass time were 73.8±16.5 and 76.4±16.9 minutes (P=0.43 and cross clamp time were 58.9±10.3 and 66.3±11.2 minutes (P=0.23 in group 1 and group 2, respectively. Mean of maximum inotrope score was 6.3±2.52 and 6.1±2.13 (P=0.65 in group 1 and group 2, respectively. We also did not find any statistically significant difference in creatine-phosphokinase-MB (CPK-MB, Troponin-I levels, lactate level and cardiac functions postoperatively. CONCLUSION: This study proves the safety and efficacy of long-acting lignocaine-based single-dose blood cardioplegia compared to the standard short-acting multi-dose blood cardioplegia in patients requiring the single valve replacement. Further studies need to be undertaken to establish this non-inferiority in situations of complex cardiac procedures especially in compromised patients.

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)

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

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.

A single dose of an inhibitor of cyclooxygenase 2, meloxicam, administered shortly after irradiation increases survival of lethally irradiated mice

Czech Academy of Sciences Publication Activity Database

Hofer, Michal; Pospíšil, Milan; Dušek, L.; Hoferová, Zuzana; Weiterová, Lenka

2011-01-01

Roč. 176, č. 2 (2011), s. 269-272 ISSN 0033-7587 R&D Projects: GA ČR(CZ) GA305/08/0158 Grant - others:GA ČR(CZ) GAP303/11/0128 Program:GA Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : cyclooxygenase-2 inhibition * lethal irradiation * survival Subject RIV: BO - Biophysics Impact factor: 2.684, year: 2011

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)

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

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

Insulin-Like Growth Factor 1 Mitigates Hematopoietic Toxicity After Lethal Total Body Irradiation

Energy Technology Data Exchange (ETDEWEB)

Zhou, Dunhua; Deoliveira, Divino; Kang, Yubin; Choi, Seung S. [Department of Medicine, Duke University Medical Center, Durham, North Carolina (United States); Li, Zhiguo [Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina (United States); Chao, Nelson J. [Department of Medicine, Duke University Medical Center, Durham, North Carolina (United States); Department of Pathology, Duke University Medical Center, Durham, North Carolina (United States); Department of Immunology, Duke University Medical Center, Durham, North Carolina (United States); Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina (United States); Chen, Benny J., E-mail: chen0032@mc.duke.edu [Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina (United States); Department of Medicine, Duke University Medical Center, Durham, North Carolina (United States)

2013-03-15

Purpose: To investigate whether and how insulin-like growth factor 1 (IGF-1) mitigates hematopoietic toxicity after total body irradiation. Methods and Materials: BALB/c mice were irradiated with a lethal dose of radiation (7.5 Gy) and treated with IGF-1 at a dose of 100 μg/dose intravenously once a day for 5 consecutive days starting within 1 hour after exposure. Survival and hematopoietic recovery were monitored. The mechanisms by which IGF-1 promotes hematopoietic recovery were also studied by use of an in vitro culture system. Results: IGF-1 protected 8 of 20 mice (40%) from lethal irradiation, whereas only 2 of 20 mice (10%) in the saline control group survived for more than 100 days after irradiation. A single dose of IGF-1 (500 μg) was as effective as daily dosing for 5 days. Positive effects were noted even when the initiation of treatment was delayed as long as 6 hours after irradiation. In comparison with the saline control group, treatment with IGF-1 significantly accelerated the recovery of both platelets and red blood cells in peripheral blood, total cell numbers, hematopoietic stem cells, and progenitor cells in the bone marrow when measured at day 14 after irradiation. IGF-1 protected both hematopoietic stem cells and progenitor cells from radiation-induced apoptosis and cell death. In addition, IGF-1 was able to facilitate the proliferation and differentiation of nonirradiated and irradiated hematopoietic progenitor cells. Conclusions: IGF-1 mitigates radiation-induced hematopoietic toxicity through protecting hematopoietic stem cells and progenitor cells from apoptosis and enhancing proliferation and differentiation of the surviving hematopoietic progenitor cells.

Insulin-Like Growth Factor 1 Mitigates Hematopoietic Toxicity After Lethal Total Body Irradiation

International Nuclear Information System (INIS)

Zhou, Dunhua; Deoliveira, Divino; Kang, Yubin; Choi, Seung S.; Li, Zhiguo; Chao, Nelson J.; Chen, Benny J.

2013-01-01

Purpose: To investigate whether and how insulin-like growth factor 1 (IGF-1) mitigates hematopoietic toxicity after total body irradiation. Methods and Materials: BALB/c mice were irradiated with a lethal dose of radiation (7.5 Gy) and treated with IGF-1 at a dose of 100 μg/dose intravenously once a day for 5 consecutive days starting within 1 hour after exposure. Survival and hematopoietic recovery were monitored. The mechanisms by which IGF-1 promotes hematopoietic recovery were also studied by use of an in vitro culture system. Results: IGF-1 protected 8 of 20 mice (40%) from lethal irradiation, whereas only 2 of 20 mice (10%) in the saline control group survived for more than 100 days after irradiation. A single dose of IGF-1 (500 μg) was as effective as daily dosing for 5 days. Positive effects were noted even when the initiation of treatment was delayed as long as 6 hours after irradiation. In comparison with the saline control group, treatment with IGF-1 significantly accelerated the recovery of both platelets and red blood cells in peripheral blood, total cell numbers, hematopoietic stem cells, and progenitor cells in the bone marrow when measured at day 14 after irradiation. IGF-1 protected both hematopoietic stem cells and progenitor cells from radiation-induced apoptosis and cell death. In addition, IGF-1 was able to facilitate the proliferation and differentiation of nonirradiated and irradiated hematopoietic progenitor cells. Conclusions: IGF-1 mitigates radiation-induced hematopoietic toxicity through protecting hematopoietic stem cells and progenitor cells from apoptosis and enhancing proliferation and differentiation of the surviving hematopoietic progenitor cells

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

The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, Andrew S.; Jain, Mayank

2012-01-01

The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely...... to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution....... This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally...

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)

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)

A Recombinant Adenovirus Expressing Ovine Interferon Tau Prevents Influenza Virus-Induced Lethality in Mice.

Science.gov (United States)

Martín, V; Pascual, E; Avia, M; Rangel, G; de Molina, A; Alejo, A; Sevilla, N

2016-01-06

Ovine interferon tau (IFN-τ) is a unique type I interferon with low toxicity and a broad host range in vivo. We report the generation of a nonreplicative recombinant adenovirus expressing biologically active IFN-τ. Using the B6.A2G-Mx1 mouse model, we showed that single-dose intranasal administration of recombinant Ad5-IFN-τ can effectively prevent lethality and disease induced by highly virulent hv-PR8 influenza virus by activating the interferon response and preventing viral replication. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Single- and multiple-dose pharmacokinetics and absolute bioavailability of tedizolid.

Science.gov (United States)

Flanagan, Shawn; Fang, Edward; Muñoz, Kelly A; Minassian, Sonia L; Prokocimer, Philippe G

2014-09-01

Tedizolid phosphate is a novel antibacterial under investigation for the treatment of gram-positive infections. This study was conducted to assess the pharmacokinetics, safety, and tolerability of intravenous tedizolid phosphate as well as the oral bioavailability of tedizolid phosphate. Double-blind, single-ascending dose, multiple-dose pharmacokinetics study, as well as tolerability and open-label crossover studies. Single center in the United States (Covance Clinical Research Unit, Madison, WI) between September 2009 and January 2010. Ninety healthy volunteers. Single intravenous (IV) doses of tedizolid phosphate 50 mg (lead-in) and 100-400 mg. Single oral and IV dose of tedizolid phosphate 200 mg in crossover fashion. Multiple IV doses of tedizolid phosphate 200 and 300 mg for up to 7 days. A dose-dependent increase was observed in the maximum plasma concentration (1.2-5.1 μg/ml) and the area under the concentration-time curve (17.4-58.7 μg × hr/ml) of tedizolid (the microbiologically active moiety of tedizolid phosphate) after single IV doses of tedizolid phosphate 100-400 mg. Administration of IV tedizolid phosphate 200 mg once/day for 7 days resulted in minimal (28%) tedizolid accumulation. The absolute oral bioavailability of tedizolid after a single 200-mg dose of tedizolid phosphate was 91%; pharmacokinetic parameters of tedizolid were similar with oral and IV administration. Treatment-related adverse events occurred in 41% of subjects. Most adverse events were related to infusion site and became more frequent with multiple dosing. In an additional 3-day tolerability study, IV tedizolid phosphate 200 mg and placebo were similarly tolerated, based on visual infusion phlebitis scores. These results from a population of healthy volunteers support once/day dosing of tedizolid phosphate 200 mg with both the oral and IV formulations, without the need for dose adjustment when switching administration routes. © 2014 Cubist Pharmaceuticals. Pharmacotherapy

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.

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

single dose pharmacokinetics of mefloquine in healthy nigerian

African Journals Online (AJOL)

BSN

Mefloquine 500mg single dose was administered and blood samples were collected ... particle size ODS Hypersil (HETP, Macclesfield, UK) at a pressure of 55 Mpa .... dose to area under the plasma drug concentration - time curve, assuming ...

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.

An antivector vaccine protects against a lethal vector-borne pathogen.

Directory of Open Access Journals (Sweden)

Milan Labuda

2006-04-01

Full Text Available Vaccines that target blood-feeding disease vectors, such as mosquitoes and ticks, have the potential to protect against the many diseases caused by vector-borne pathogens. We tested the ability of an anti-tick vaccine derived from a tick cement protein (64TRP of Rhipicephalus appendiculatus to protect mice against tick-borne encephalitis virus (TBEV transmitted by infected Ixodes ricinus ticks. The vaccine has a "dual action" in immunized animals: when infested with ticks, the inflammatory and immune responses first disrupt the skin feeding site, resulting in impaired blood feeding, and then specific anti-64TRP antibodies cross-react with midgut antigenic epitopes, causing rupture of the tick midgut and death of engorged ticks. Three parameters were measured: "transmission," number of uninfected nymphal ticks that became infected when cofeeding with an infected adult female tick; "support," number of mice supporting virus transmission from the infected tick to cofeeding uninfected nymphs; and "survival," number of mice that survived infection by tick bite and subsequent challenge by intraperitoneal inoculation of a lethal dose of TBEV. We show that one dose of the 64TRP vaccine protects mice against lethal challenge by infected ticks; control animals developed a fatal viral encephalitis. The protective effect of the 64TRP vaccine was comparable to that of a single dose of a commercial TBEV vaccine, while the transmission-blocking effect of 64TRP was better than that of the antiviral vaccine in reducing the number of animals supporting virus transmission. By contrast, the commercial antitick vaccine (TickGARD that targets only the tick's midgut showed transmission-blocking activity but was not protective. The 64TRP vaccine demonstrates the potential to control vector-borne disease by interfering with pathogen transmission, apparently by mediating a local cutaneous inflammatory immune response at the tick-feeding site.

The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

International Nuclear Information System (INIS)

Thomsen, Kristina J.; Murray, Andrew; Jain, Mayank

2012-01-01

The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution. This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally, it is an implicit assumption in such analysis that any over-dispersion is not significantly dose dependent. In this study we have undertaken laboratory investigations of the dose dependency of over-dispersion using a well-bleached modern sample with an average measured dose of 36 ± 3 mGy. This sample was prepared as heated (750 °C for 1 h), bleached and untreated portions which were then given uniform gamma doses ranging from 100 mGy to 208 Gy. We show that for these samples the relative laboratory over-dispersion is not constant as a function of dose and that the over-dispersion is smaller in heated samples. We also show that the dim grains in the distributions have a greater over-dispersion than the bright grains, implying that insensitive samples will have greater values of over-dispersion than sensitive samples.

Single Dose Versus 3 Doses of Intramuscular Benzathine Penicillin for Early Syphilis in HIV: A Randomized Clinical Trial.

Science.gov (United States)

Andrade, Roberto; Rodriguez-Barradas, Maria C; Yasukawa, Kosuke; Villarreal, Erick; Ross, Michael; Serpa, Jose A

2017-03-15

Patients coinfected with syphilis and human immunodeficiency virus (HIV) may have a slower decrease in rapid plasma reagin (RPR) titers. Currently a single dose of 2.4 million units of intramuscular benzathine penicillin G (BPG) is recommended for the treatment of early syphilis. Some observational studies have suggested that this regimen may lead to high failure rates in coinfected patients. We conducted an open-label randomized clinical trial to compare the efficacy of single-dose and 3-dose regimens of BPG for the treatment of early syphilis in HIV-infected individuals. RPR titers were monitored every 3 months. Treatment success was defined as a decrease in RPR titers of ≥2 dilutions (4-fold) during a 12-month follow-up period. Sixty-four patients were included. In the intention-to-treat analysis, treatment success rates were 80% (28 of 35 subjects) and 93% (27 of 29 subjects) in the single-dose and 3-dose regimens, respectively (absolute difference, 13% [95% confidence interval {CI}, -5% to 30%; P = .17). In the per-protocol analysis, success rates were 93% (27 of 29) and 100% in the single-dose and 3-dose regimens, respectively (absolute difference, 7% [95% CI, -7% to 22%]; P = .49). CD4 T-cell count, RPR titer and syphilis stage did not affect treatment results. When compared with a single dose of BPG, a 3-dose regimen did not improve syphilis serological outcomes. Our results support the Centers for Disease Control and Prevention recommendation of a single dose of BPG in HIV-infected patients with early syphilis. NCT02611765. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Efficacy of Single-Dose and Triple-Dose Albendazole and Mebendazole against Soil-Transmitted Helminths and Taenia spp.: A Randomized Controlled Trial

Science.gov (United States)

Steinmann, Peter; Utzinger, Jürg; Du, Zun-Wei; Jiang, Jin-Yong; Chen, Jia-Xu; Hattendorf, Jan; Zhou, Hui; Zhou, Xiao-Nong

2011-01-01

Background The control of soil-transmitted helminth (STH) infections currently relies on the large-scale administration of single-dose oral albendazole or mebendazole. However, these treatment regimens have limited efficacy against hookworm and Trichuris trichiura in terms of cure rates (CR), whereas fecal egg reduction rates (ERR) are generally high for all common STH species. We compared the efficacy of single-dose versus triple-dose treatment against hookworm and other STHs in a community-based randomized controlled trial in the People's Republic of China. Methodology/Principal findings The hookworm CR and fecal ERR were assessed in 314 individuals aged ≥5 years who submitted two stool samples before and 3–4 weeks after administration of single-dose oral albendazole (400 mg) or mebendazole (500 mg) or triple-dose albendazole (3×400 mg over 3 consecutive days) or mebendazole (3×500 mg over 3 consecutive days). Efficacy against T. trichiura, Ascaris lumbricoides, and Taenia spp. was also assessed. Albendazole cured significantly more hookworm infections than mebendazole in both treatment regimens (single dose: respective CRs 69% (95% confidence interval [CI]: 55–81%) and 29% (95% CI: 20–45%); triple dose: respective CRs 92% (95% CI: 81–98%) and 54% (95% CI: 46–71%)). ERRs followed the same pattern (single dose: 97% versus 84%; triple dose: 99.7% versus 96%). Triple-dose regimens outperformed single doses against T. trichiura; three doses of mebendazole – the most efficacious treatment tested – cured 71% (95% CI: 57–82%). Both single and triple doses of either drug were highly efficacious against A. lumbricoides (CR: 93–97%; ERR: all >99.9%). Triple dose regimens cured all Taenia spp. infections, whereas single dose applications cured only half of them. Conclusions/Significance Single-dose oral albendazole is more efficacious against hookworm than mebendazole. To achieve high CRs against both hookworm and T. trichiura, triple-dose regimens are

Efficacy of single dose of a bivalent vaccine containing inactivated Newcastle disease virus and reassortant highly pathogenic avian influenza H5N1 virus against lethal HPAI and NDV infection in chickens.

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Dong-Hun Lee

Full Text Available Highly pathogenic avian influenza (HPAI and Newcastle disease (ND are 2 devastating diseases of poultry, which cause great economic losses to the poultry industry. In the present study, we developed a bivalent vaccine containing antigens of inactivated ND and reassortant HPAI H5N1 viruses as a candidate poultry vaccine, and we evaluated its immunogenicity and protective efficacy in specific pathogen-free chickens. The 6:2 reassortant H5N1 vaccine strain containing the surface genes of the A/Chicken/Korea/ES/2003(H5N1 virus was successfully generated by reverse genetics. A polybasic cleavage site of the hemagglutinin segment was replaced by a monobasic cleavage site. We characterized the reverse genetics-derived reassortant HPAI H5N1 clade 2.5 vaccine strain by evaluating its growth kinetics in eggs, minimum effective dose in chickens, and cross-clade immunogenicity against HPAI clade 1 and 2. The bivalent vaccine was prepared by emulsifying inactivated ND (La Sota strain and reassortant HPAI viruses with Montanide ISA 70 adjuvant. A single immunization with this vaccine induced high levels of hemagglutination-inhibiting antibody titers and protected chickens against a lethal challenge with the wild-type HPAI and ND viruses. Our results demonstrate that the bivalent, inactivated vaccine developed in this study is a promising approach for the control of both HPAI H5N1 and ND viral infections.

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

International Nuclear Information System (INIS)

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

1984-01-01

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

The effect of a single lethal X-irradiation exposure on the activity of lipoprotein lipase in the tissues of the rat

International Nuclear Information System (INIS)

Sedlakova, A.; Ahlers, I.; Praslicka, M.

1979-01-01

Wistar male rats, both fed and fasting for 16 h prior to irradiation, were exposed to a single lethal X-ray dose of 387 mC/kg (1500R). The activity of lipoprotein lipase in white adipose (epididymal) tissue and heart muscle and the concentration of serum triglycerides were determined at 1, 6, 24, 48, and 72 h after irradiation. In the early time periods, at 1 and 6 h after exposure, the activity of lipoprotein lipase decreased in adipose tissue and increased in heart muscle of the irradiated fed rats; in fasting rats it decreased in heart muscle at 1 h after exposure. The concentration of serum triglycerides increased at 1 h and decreased at 6 h after exposure in fed rats. In these rats, alterations in serum triglycerides correlated with changes in lipoprotein lipase activity in adipose tissue. Alterations observed at the later time periods were more dependent on the time interval between irradiation and the analysis. Lipoprotein lipase activity increased with time after irradiation up to the maximal values at 72 h. Fasting prior to and after irradiation substantially modified the response of animals to radiation. (author)

Evaluation of the sterility of single-dose medications used in a multiple-dose fashion.

Science.gov (United States)

Martin, Elizabeth P; Mukherjee, Jean; Sharp, Claire R; Sinnott-Stutzman, Virginia B

2017-11-01

Bacterial proliferation was evaluated in single-dose medications used in a multi-dose fashion and when medications were intentionally inoculated with bacteria. Of 5 experimentally punctured medications, 1 of 75 vials (50% dextrose) became contaminated. When intentionally inoculated, hydroxyethyl starch and heparinized saline supported microbial growth. Based on these findings, it is recommended that hydroxyethyl starch and heparinized saline not be used in a multi-dose fashion.

Low-dose radiation-induced endothelial cell retraction

International Nuclear Information System (INIS)

Kantak, S.S.; Onoda, J.M.; Diglio, C.A.; Harper Hospital, Detroit, MI

1993-01-01

The data presented here are representative of a series of studies designed to characterize low-dose radiation effects on pulmonary microvascular endothelium. Data suggest that post-irradiation lung injuries (e.g. oedema) may be induced with only a single fraction of therapeutic radiation, and thus microscopic oedema may initiate prior to the lethal effects of radiation on the microvascular endothelium, and much earlier than would be suggested by the time course for clinically-detectable oedema. (author)

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

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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.

Single-dose-response curves of murine gastrointestinal crypt stem cells

International Nuclear Information System (INIS)

Masuda, K.; Withers, H.R.; Mason, K.A.; Chen, K.Y.

1977-01-01

Dose-response curves for the reproductive capacity of crypt stem cells of murine colonic, jejunal, and gastric mucosae exposed in situ to multifractionated gamma ray exposures were analyzed and single-dose-survival curves of these cells were constructed. The following conclusions were drawn: (1) The single-dose-response curves bend downward over a dose range of approximately 200 to 1500 rad; (2) cell death seems to be due to nonrepairable damage at doses less than 250 rad for colon, and 220 rad for jejunum; (3) there are 21, 110, and 140 stem cells per crypt of gastric, colonic, and jejunal mucosa, respectively; and (4) jejunal stem cells are the most radiosensitive and gastric mucosal stem cells are the most resistant

Single-dose radiotherapy for painful bone metastases

International Nuclear Information System (INIS)

Kal, H.B.

1999-01-01

Background: External beam radiotherapy is frequently applied for palliative treatment of painful bone lesions with a variety of fractionation schemes. There is a continuous interest to administer only 1 or a few dose fractions for inducing pain relief. Methods: A review of the literature was made with the aim to determine whether a treatment can be deduced that is simple and effective. The linear-quadratic (L-Q) concept was applied to compare reported therapy schemes which each other for the iso-effect pain relief. Results: Single-dose and fractionated radiotherapy resulted in partial or complete pain relief in about 80% of the patients. Complete responses have been observed in about 43% of the patients. For patients responding to treatment, the duration of pain relief is at least 3 to 4 months with reported duration of up to 1 year or even longer. Conclusion: Based on this review of literature data concerning randomized trials a treatment with a single dose of 8 Gy is effective for inducing pain relief. (orig.) [de

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)

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)

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.

Potential of neurotoxicity after a single oral dose of 4-bromo-, 4-chloro-, 4-fluoro- or 4-iodoaniline in rats.

Science.gov (United States)

Okazaki, Yoshimasa; Yamashita, Kotaro; Ishii, Hiroyuki; Sudo, Masato; Tsuchitani, Minoru

2003-01-01

The potential for neurotoxicity after a single oral dose of four halogenated aniline derivatives--4-bromoaniline (4-BA), 4-chloroaniline (4-CA), 4- fluoroaniline (4-FA) and 4-iodoaniline (4-IA)--was given to rats was investigated at or near the lethal dosage level. Hindlimb paralysis was found in the 4-BA, 4-CA and 4-FA groups on clinical observation, with the maximum incidence of 100% in the 4-BA and 4-FA groups and 66.7% in the 4-CA group. Detailed clinical observations with functional tests identified the following effects: reduced response of hindlimb extensor thrust, gait abnormality in the open field and decreased grip strength in the fore- or hindlimbs in the 4-BA, 4-CA and 4-FA groups; decreased number of supported rearing episodes in the open field in the 4-BA and 4-CA groups; abnormal landing in the aerial righting reflex in the 4-BA and 4-FA groups; and prolonged surface righting reflex in the 4-BA group. Spongy change in the white matter of the spinal cord and brainstem and nerve fibre degeneration in the peripheral nerves were found in all haloaniline-treated groups. The central and peripheral nervous systems were most severely affected in the 4-BA group and the lesions in the 4-IA group were limited in grade. This study demonstrates that a bolus dose of 4-haloanilines to rats induces a neurotoxicity similar in character to that evoked by the parent aniline. The decreasing order of neurotoxic potential appears to be 4-BA > 4-FA > or = 4-CA > 4-IA when comparing at or near the lethal dosage level. Copyright 2003 John Wiley & Sons, Ltd.

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

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

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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.

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: ...

Changes in rat liver and adipose tissue lipogenesis after single lethal X-irradiation: modification by the restricted food intake

International Nuclear Information System (INIS)

Sedlakova, A.; Ahlers, I.; Praslicka, M.

1981-01-01

Male rats of Wistar strain were adapted during a 4-week period to the nutritional regimes of meal feeding (MF) and ad libitum (AL) and were irradiated with the single whole-body lethal X-ray dose 14.35 Gy after 22 h of fasting. Within the intervals 1, 24, 48 and 72 h after irradiation lipogenesis changes in the liver were studied by measuring 1- 14 C-acetate incorporation (74 KBq) in the total lipids, fatty acids and cholesterol, and in the white adipose tissue pieces by measuring U- 14 C-glucose incorporation (74 KBq) in the total lipids, fatty acids and glyceride glycerol. Lipogenesis increased in the liver of the irradiated rats as compared with sham irradiated rats and reached the maximal values at 72 h after irradiation in AL animals and at 48 h after irradiation in MF animals. Lipogenesis in the adipose tissue decreased in the irradiated rats as compared with the sham irradiated ones and continued to decrease with the post-irradiation period. The adaptation to the nutritional regime of meal feeding markedly modified lipogenesis in the liver and the adipose tissue of the irradiated rats. Long-term fasting (before and after irradiation) was supposed to be another modifying factor in the lipogenesis changes. Lipogenesis changes in the liver depended on the MF nutritional regime. (author)

Changes in rat liver and adipose tissue lipogenesis after single lethal X-irradiation: modification by the restricted food intake

Energy Technology Data Exchange (ETDEWEB)

Sedlakova, A; Ahlers, I; Praslicka, M [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

1981-01-01

Male rats of Wistar strain were adapted during a 4-week period to the nutritional regimes of meal feeding (MF) and ad libitum (AL) and were irradiated with the single whole-body lethal X-ray dose 14.35 Gy after 22 h of fasting. Within the intervals 1, 24, 48 and 72 h after irradiation lipogenesis changes in the liver were studied by measuring 1-/sup 14/C-acetate incorporation (74 KBq) in the total lipids, fatty acids and cholesterol, and in the white adipose tissue pieces by measuring U-/sup 14/C-glucose incorporation (74 KBq) in the total lipids, fatty acids and glyceride glycerol. Lipogenesis increased in the liver of the irradiated rats as compared with sham irradiated rats and reached the maximal values at 72 h after irradiation in AL animals and at 48 h after irradiation in MF animals. Lipogenesis in the adipose tissue decreased in the irradiated rats as compared with the sham irradiated ones and continued to decrease with the post-irradiation period. The adaptation to the nutritional regime of meal feeding markedly modified lipogenesis in the liver and the adipose tissue of the irradiated rats. Long-term fasting (before and after irradiation) was supposed to be another modifying factor in the lipogenesis changes. Lipogenesis changes in the liver depended on the MF nutritional regime.

Single point estimation of phenytoin dosing: a reappraisal.

Science.gov (United States)

Koup, J R; Gibaldi, M; Godolphin, W

1981-11-01

A previously proposed method for estimation of phenytoin dosing requirement using a single serum sample obtained 24 hours after intravenous loading dose (18 mg/Kg) has been re-evaluated. Using more realistic values for the volume of distribution of phenytoin (0.4 to 1.2 L/Kg), simulations indicate that the proposed method will fail to consistently predict dosage requirements. Additional simulations indicate that two samples obtained during the 24 hour interval following the iv loading dose could be used to more reliably predict phenytoin dose requirement. Because of the nonlinear relationship which exists between phenytoin dose administration rate (RO) and the mean steady state serum concentration (CSS), small errors in prediction of the required RO result in much larger errors in CSS.

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

Back to the future: revisiting HIV-1 lethal mutagenesis

Science.gov (United States)

Dapp, Michael J.; Patterson, Steven E.; Mansky, Louis M.

2012-01-01

The concept of eliminating HIV-1 infectivity by elevating the viral mutation rate was first proposed over a decade ago, even though the general concept had been conceived earlier for RNA viruses. Lethal mutagenesis was originally viewed as a novel chemotherapeutic approach for treating HIV-1 infection in which use of a viral mutagen would over multiple rounds of replication lead to the lethal accumulation of mutations, rendering the virus population non infectious – known as the slow mutation accumulation model. There have been limitations in obtaining good efficacy data with drug leads, leaving some doubt into clinical translation. More recent studies of the APOBEC3 proteins as well as new progress in the use of nucleoside analogs for inducing lethal mutagenesis have helped to refocus attention on rapid induction of HIV-1 lethal mutagenesis in a single or limited number of replication cycles leading to a rapid mutation accumulation model. PMID:23195922

Pharmacokinetics of sulfamethoxazole and trimethoprim in Pacific white shrimp, Litopenaeus vannamei, after oral administration of single-dose and multiple-dose.

Science.gov (United States)

Ma, Rongrong; Wang, Yuan; Zou, Xiong; Hu, Kun; Sun, Beibei; Fang, Wenhong; Fu, Guihong; Yang, Xianle

2017-06-01

The tissue distribution and depletion of sulfamethoxazole (SMZ) and trimethoprim (TMP) were studied in Pacific white shrimp, Litopenaeus vannamei, after single-dose and multiple-dose oral administration of SMZ-TMP (5:1) via medicated feed. In single-dose oral administration, shrimps were fed once at a dose of 100 mg/kg (drug weight/body weight). In multiple-dose oral administration, shrimps were fed three times a day for three consecutive days at a dose of 100mg/kg. The results showed the kinetic characteristic of SMZ was different from TMP in Pacific white shrimp. In the single-dose administration, the SMZ was widely distributed in the tissues, while TMP was highly concentrated in the hepatopancreas. The t 1/2z values of SMZ were larger and persist longer than TMP in Pacific white shrimp. In the multiple-dose administration, SMZ accumulated well in the tissues, and reached steady state level after successive administrations, while TMP did not. TMP concentration even appeared the downward trend with the increase of drug times. Compared with the single dose, the t 1/2z values of SMZ in hepatopancreas (8.22-11.33h) and muscle (6.53-10.92h) of Pacific white shrimps rose, but the haemolymph dropped (13.76-11.03) in the multiple-dose oral administration. Meanwhile, the corresponding values of TMP also rose in hepatopancreas (4.53-9.65h) and muscle (2.12-2.71h), and declined in haemolymph (7.38-5.25h) following single-dose and multiple-dose oral administration in Pacific white shrimps. In addition, it is worth mentioning that the ratios of SMZ and TMP were unusually larger than the general aim ratio. Copyright © 2017 Elsevier B.V. All rights reserved.

Efficacy and Safety of Single and Double Doses of Ivermectin versus 7-Day High Dose Albendazole for Chronic Strongyloidiasis

Science.gov (United States)

Suputtamongkol, Yupin; Premasathian, Nalinee; Bhumimuang, Kid; Waywa, Duangdao; Nilganuwong, Surasak; Karuphong, Ekkapun; Anekthananon, Thanomsak; Wanachiwanawin, Darawan; Silpasakorn, Saowaluk

2011-01-01

Background Strongyloidiasis, caused by an intestinal helminth Strongyloides stercoralis, is common throughout the tropics. It remains an important health problem due to autoinfection, which may result in hyperinfection and disseminated infection in immunosuppressed patients, especially patients receiving chemotherapy or corticosteroid treatment. Ivermectin and albendazole are effective against strongyloidiasis. However, the efficacy and the most effective dosing regimen are to be determined. Methods A prospective, randomized, open study was conducted in which a 7-day course of oral albendazole 800 mg daily was compared with a single dose (200 microgram/kilogram body weight), or double doses, given 2 weeks apart, of ivermectin in Thai patients with chronic strongyloidiasis. Patients were followed-up with 2 weeks after initiation of treatment, then 1 month, 3 months, 6 months, 9 months, and 1 year after treatment. Combination of direct microscopic examination of fecal smear, formol-ether concentration method, and modified Koga agar plate culture were used to detect strongyloides larvae in two consecutive fecal samples in each follow-up visit. The primary endpoint was clearance of strongyloides larvae from feces after treatment and at one year follow-up. Results Ninety patients were included in the analysis (30, 31 and 29 patients in albendazole, single dose, and double doses ivermectin group, respectively). All except one patient in this study had at least one concomitant disease. Diabetes mellitus, systemic lupus erythrematosus, nephrotic syndrome, hematologic malignancy, solid tumor and human immunodeficiency virus infection were common concomitant diseases in these patients. The median (range) duration of follow-up were 19 (2–76) weeks in albendazole group, 39 (2–74) weeks in single dose ivermectin group, and 26 (2–74) weeks in double doses ivermectin group. Parasitological cure rate were 63.3%, 96.8% and 93.1% in albendazole, single dose oral ivermectin

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).

Efficacy of various single-dose regimens of ceftriaxone in ...

African Journals Online (AJOL)

The therapeutic efficacy of single intramuscular doses of ceftriaxone (Rocephin; Roche) (62,S, 125 and 250 mg), administered without probenecid, was evaluated in 167 adult males with uncomplicated acute gonococcal urethritis. Cure rates of 100% were achieved at 62,5 mg and 250 mg. In the 125 mg dose group, ...

SINGLE-DOSE VERSUS 3-DAY PROPHYLAXIS WITH CIPROFLOXACIN IN TRANSURETHRAL SURGERY - A CLINICAL-TRIAL

NARCIS (Netherlands)

BIJL, W; JANKNEGT, RA

1993-01-01

in 235 patients who underwent transurethral surgery, perioperative oral ciprofloxacin prophylaxis was given as a single dose 500 mg versus a 3-day regimen. Out of 180 evaluable patients, 84 received a single dose and 96 received a 3-day course. In the single dose prophylaxis group there were 5

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.

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.

Single event effects and total ionizing dose effects of typical VDMOSFET devices

International Nuclear Information System (INIS)

Lou Jianshe; Cai Nan; Liu Jiaxin; Wu Qinzhi; Wang Jia

2012-01-01

In this work, single event effects and total ionizing dose effects of typical VDMOSFET irradiated by 60 Co γ-rays and 252 Cf source were studied. The single event burnout and single event gate rupture (SEB/SEGR) effects were investigated, and the relationship between drain-source breakdown voltage and ionizing dose was obtained. The results showed that the VDMOSFET devices were sensitive to SEB and SEGR, and measures to improve their resistance to SEB and SEGR should be considered seriously for their space applications. The drain-source breakdown voltage was sensitive to total ionizing dose effects as the threshold voltage. In assessing the devices' resistance to the total ionizing dose effects, both the threshold voltage and the drain-source breakdown voltage should be taken into account. (authors)

5-Lipoxygenase Deficiency Reduces Acetaminophen-Induced Hepatotoxicity and Lethality

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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.

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)

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.

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.)

Tuning of the Lethal Response to Multiple Stressors with a Single-Site Mutation during Clinical Infection by Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Krishan Kumar

2017-10-01

Full Text Available The agr system of Staphylococcus aureus promotes invasion of host tissues, and as expected, agents that block agr quorum sensing have anti-infective properties. Paradoxically, agr-defective mutants are frequently recovered from patients, especially those persistently infected with S. aureus. We found that an agr deficiency increased survival of cultured bacteria during severe stress, such as treatment with gentamicin, ciprofloxacin, heat, or low pH. With daptomycin, deletion of agr decreased survival. Therefore, agr activity can be either detrimental or protective, depending on the type of lethal stress. Deletion of agr had no effect on the ability of the antimicrobials to block bacterial growth, indicating that agr effects are limited to lethal action. Thus, the effect of an agr deletion is on bacterial tolerance, not resistance. For gentamicin and daptomycin, activity can be altered by agr-regulated secreted factors. For ciprofloxacin, a detrimental function was downregulation of glutathione peroxidase (bsaA, an enzyme responsible for defense against oxidative stress. Deficiencies in agr and bsaA were epistatic for survival, consistent with agr having a destructive role mediated by reactive oxygen species. Enhanced susceptibility to lethal stress by wild-type agr, particularly antimicrobial stress, helps explain why inactivating mutations in S. aureus agr commonly occur in hospitalized patients during infection. Moreover, the agr quorum-sensing system of S. aureus provides a clinically relevant example in which a single-step change in the response to severe stress alters the evolutionary path of a pathogen during infection.

Prevention of lethal graft-versus-host disease in mice by monoclonal antibodies directed against T cells or their subsets.I.Evidence for the induction of a state of tolerance based on suppression

NARCIS (Netherlands)

Knulst, A.C.; Tibbe, G.J.M.; Noort, W.A.; Bril-Bazuin, C.; Benner, R.; Savelkoul, H.F.J.

1994-01-01

Lethal GVHD in the fully allogeneic BALB/c (donor)-(C57BL x CBA)F1 (recipient) mouse strain combination could be prevented by a single dose of IgG2b monoclonal antibodies (moAb) directed to T cells. The influence of the time of administration of this moAb after GVHD induction and the effect of

Dose optimisation in single plane interstitial brachytherapy

DEFF Research Database (Denmark)

Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette Benedicte

2006-01-01

patients,       treated for recurrent rectal and cervical cancer, flexible catheters were       sutured intra-operatively to the tumour bed in areas with compromised       surgical margin. Both non-optimised, geometrically and graphically       optimised CT -based dose plans were made. The overdose index...... on the       regularity of the implant, such that the benefit of optimisation was       larger for irregular implants. OI and HI correlated strongly with target       volume limiting the usability of these parameters for comparison of dose       plans between patients. CONCLUSIONS: Dwell time optimisation significantly......BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

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.

Effective dose to staff from interventional procedures: Estimations from single and double dosimetry

International Nuclear Information System (INIS)

Kuipers, G.; Velders, X. L.

2009-01-01

The exposure of 11 physicians performing interventional procedures was measured by means of two personal dosemeters. One personal dosemeter was worn outside the lead apron and an additional under the lead apron. The study was set up in order to determine the added value of a dosemeter worn under the lead apron. With the doses measured, the effective doses of the physicians were estimated using an algorithm for single dosimetry and two algorithms for double dosimetry. The effective doses calculated with the single dosimetry algorithm ranged from 0.11 to 0.85 mSv in 4 weeks. With the double dosimetry algorithms, the effective doses ranged from 0.02 mSv to 0.47 mSv. The statistical analysis revealed no significant differences in the accuracy of the effective doses calculated with single or double dosimetry algorithms. It was concluded that the effective dose cannot be considered a more accurate estimate when two dosemeters are used instead of one. (authors)

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, ...

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

Failure Rate of Single Dose Methotrexate in Managment of Ectopic Pregnancy

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Feras Sendy

2015-01-01

Full Text Available Background. One of the treatment modalities for ectopic pregnancy is methotrexate. The purpose of this study is to identify the failure rate of methotrexate in treating patients with ectopic pregnancy as well as the risk factors leading to treatment failure. Methods. A retrospective chart review of 225 patients who received methotrexate as a primary management option for ectopic pregnancy. Failure of single dose of methotrexate was defined as drop of BHCG level less than or equal to 14% in the seventh day after administration of methotrexate. Results. 225 patients had methotrexate. Most of the patients (151 (67% received methotrexate based on the following formula: f 50 mg X body surface area. Single dose of methotrexate was successful in 72% (162/225 of the patients. 28% (63/225 were labeled as failure of single dose of methotrexate because of suboptimal drop in BhCG. 63% (40/63 of failure received a second dose of methotrexate, and 37% (23/63 underwent surgical treatment. Among patient who received initial dose of methotrexate, 71% had moderate or severe pain, and 58% had ectopic mass size of more than 4 cm on ultrasound. Conclusion. Liberal use of medical treatment of ectopic pregnancy results in 71% success rate.

Failure rate of single dose methotrexate in managment of ectopic pregnancy.

Science.gov (United States)

Sendy, Feras; AlShehri, Eman; AlAjmi, Amani; Bamanie, Elham; Appani, Surekha; Shams, Taghreed

2015-01-01

Background. One of the treatment modalities for ectopic pregnancy is methotrexate. The purpose of this study is to identify the failure rate of methotrexate in treating patients with ectopic pregnancy as well as the risk factors leading to treatment failure. Methods. A retrospective chart review of 225 patients who received methotrexate as a primary management option for ectopic pregnancy. Failure of single dose of methotrexate was defined as drop of BHCG level less than or equal to 14% in the seventh day after administration of methotrexate. Results. 225 patients had methotrexate. Most of the patients (151 (67%)) received methotrexate based on the following formula: f 50 mg X body surface area. Single dose of methotrexate was successful in 72% (162/225) of the patients. 28% (63/225) were labeled as failure of single dose of methotrexate because of suboptimal drop in BhCG. 63% (40/63) of failure received a second dose of methotrexate, and 37% (23/63) underwent surgical treatment. Among patient who received initial dose of methotrexate, 71% had moderate or severe pain, and 58% had ectopic mass size of more than 4 cm on ultrasound. Conclusion. Liberal use of medical treatment of ectopic pregnancy results in 71% success rate.

Correlation between the single, high dose of ingested baclofen and clinical symptoms

Directory of Open Access Journals (Sweden)

Jacek Sein Anand

2017-12-01

There is a statistically significant correlation between the dose of ingested baclofen and the presence of acute respiratory failure, and duration of mechanical ventilation. Patients who have taken a single dose of baclofen of 200 mg, or higher, should be managed in centres able to provide continuous monitoring of life functions. Those with a higher level of a single dose of baclofen ingestion (>500 mg, should be hospitalized in a Toxicology Unit or Intensive Care Unit able to provide airway support and mechanical ventilation.

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

Annotating novel genes by integrating synthetic lethals and genomic information

Directory of Open Access Journals (Sweden)

Faty Mahamadou

2008-01-01

Full Text Available Abstract Background Large scale screening for synthetic lethality serves as a common tool in yeast genetics to systematically search for genes that play a role in specific biological processes. Often the amounts of data resulting from a single large scale screen far exceed the capacities of experimental characterization of every identified target. Thus, there is need for computational tools that select promising candidate genes in order to reduce the number of follow-up experiments to a manageable size. Results We analyze synthetic lethality data for arp1 and jnm1, two spindle migration genes, in order to identify novel members in this process. To this end, we use an unsupervised statistical method that integrates additional information from biological data sources, such as gene expression, phenotypic profiling, RNA degradation and sequence similarity. Different from existing methods that require large amounts of synthetic lethal data, our method merely relies on synthetic lethality information from two single screens. Using a Multivariate Gaussian Mixture Model, we determine the best subset of features that assign the target genes to two groups. The approach identifies a small group of genes as candidates involved in spindle migration. Experimental testing confirms the majority of our candidates and we present she1 (YBL031W as a novel gene involved in spindle migration. We applied the statistical methodology also to TOR2 signaling as another example. Conclusion We demonstrate the general use of Multivariate Gaussian Mixture Modeling for selecting candidate genes for experimental characterization from synthetic lethality data sets. For the given example, integration of different data sources contributes to the identification of genetic interaction partners of arp1 and jnm1 that play a role in the same biological process.

Protect Patients by Using Single- and Multi-Dose Vials Correctly

Centers for Disease Control (CDC) Podcasts

2014-07-10

CDC’s One & Only Campaign urges healthcare providers to recognize the differences between single-dose and multi-dose vials, and to understand appropriate use of each container type.  Created: 7/10/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/10/2014.

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)

Developing a single-aliquot protocol for measuring equivalent dose in biogenic carbonates

International Nuclear Information System (INIS)

Stirling, R.J.; Duller, G.A.T.; Roberts, H.M.

2012-01-01

Exploiting biogenic carbonates as thermoluminescence dosimeters requires an understanding of trap kinetics and an appropriate sequence with which to measure equivalent dose. The trap kinetics of two high temperature peaks (peaks II and III) from calcitic snail opercula have been investigated resulting in the calculation of lifetimes of 7.4 × 10 7 and 1.4 × 10 11 years for the two peaks respectively. Two measurement sequences, based upon changes in the application and measurement of a test dose, have been applied to peaks II and III, and though both methods were equally successful in dose recovery and production of a dose response curve some differences were observed. Primarily, the use of method 1 lead to dose dependant sensitivity change implying competition effects occurring during irradiation; method 2 did not experience this phenomenon. As a consequence method 2 was chosen as the most appropriate protocol for single-aliquot dating of this material. When assessing the TL behaviour of the two peaks, peak II performed poorly in dose recovery experiments recovering a dose 60–100% larger than that applied. Disproportionate growth of peak II in response to a beta dose applied prior to measurement, compared to growth following regeneration doses indicated that peak II was not suitable for use in single-aliquot protocols. However, dose recovery results for peak III were all within errors of unity of the given dose, and peak III was therefore chosen as the most appropriate peak for TL dosimetry in these single-aliquot procedures. The lifetime of charge in peak III is sufficient to date over many millions of years, and furthermore using the chosen method 2 the dose response curve has a D 0 of 3,250 ± 163 Gy allowing dating to over 3 million years.

Impact of multiple-dose versus single-dose inhaler devices on COPD patients’ persistence with long-acting β2-agonists: a dispensing database analysis

Science.gov (United States)

van Boven, Job FM; van Raaij, Joost J; van der Galiën, Ruben; Postma, Maarten J; van der Molen, Thys; Dekhuijzen, PN Richard; Vegter, Stefan

2014-01-01

Background: With a growing availability of different devices and types of medication, additional evidence is required to assist clinicians in prescribing the optimal medication in relation to chronic obstructive pulmonary disease (COPD) patients’ persistence with long-acting β2-agonists (LABAs). Aims: To assess the impact of the type of inhaler device (multiple-dose versus single-dose inhalers) on 1-year persistence and switching patterns with LABAs. Methods: A retrospective observational cohort study was performed comparing a cohort of patients initiating multiple-dose inhalers and a cohort initiating single-dose inhalers. The study population consisted of long-acting bronchodilator naive COPD patients, initiating inhalation therapy with mono-LABAs (formoterol, indacaterol or salmeterol). Analyses were performed using pharmacy dispensing data from 1994 to 2012, obtained from the IADB.nl database. Study outcomes were 1-year persistence and switching patterns. Results were adjusted for initial prescriber, initial medication, dosing regimen and relevant comorbidities. Results: In all, 575 patients initiating LABAs were included in the final study cohort. Among them, 475 (83%) initiated a multiple-dose inhaler and 100 (17%) a single-dose inhaler. Further, 269 (47%) initiated formoterol, 9 (2%) indacaterol and 297 (52%) salmeterol. There was no significant difference in persistence between users of multiple-dose or single-dose inhalers (hazard ratio: 0.98, 95% confidence interval: 0.76–1.26, P=0.99). Over 80% re-started or switched medication. Conclusions: There seems no impact of inhaler device (multiple-dose versus single-dose inhalers) on COPD patients’ persistence with LABAs. Over 80% of patients who initially seemed to discontinue LABAs, re-started their initial medication or switched inhalers or medication within 1 year. PMID:25274453

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.)

Variable dose rate single-arc IMAT delivered with a constant dose rate and variable angular spacing

International Nuclear Information System (INIS)

Tang, Grace; Earl, Matthew A; Yu, Cedric X

2009-01-01

Single-arc intensity-modulated arc therapy (IMAT) has gained worldwide interest in both research and clinical implementation due to its superior plan quality and delivery efficiency. Single-arc IMAT techniques such as the Varian RapidArc(TM) deliver conformal dose distributions to the target in one single gantry rotation, resulting in a delivery time in the order of 2 min. The segments in these techniques are evenly distributed within an arc and are allowed to have different monitor unit (MU) weightings. Therefore, a variable dose-rate (VDR) is required for delivery. Because the VDR requirement complicates the control hardware and software of the linear accelerators (linacs) and prevents most existing linacs from delivering IMAT, we propose an alternative planning approach for IMAT using constant dose-rate (CDR) delivery with variable angular spacing. We prove the equivalence by converting VDR-optimized RapidArc plans to CDR plans, where the evenly spaced beams in the VDR plan are redistributed to uneven spacing such that the segments with larger MU weighting occupy a greater angular interval. To minimize perturbation in the optimized dose distribution, the angular deviation of the segments was restricted to ≤± 5 deg. This restriction requires the treatment arc to be broken into multiple sectors such that the local MU fluctuation within each sector is reduced, thereby lowering the angular deviation of the segments during redistribution. The converted CDR plans were delivered with a single gantry sweep as in the VDR plans but each sector was delivered with a different value of CDR. For four patient cases, including two head-and-neck, one brain and one prostate, all CDR plans developed with the variable spacing scheme produced similar dose distributions to the original VDR plans. For plans with complex angular MU distributions, the number of sectors increased up to four in the CDR plans in order to maintain the original plan quality. Since each sector was

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

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

The population genetics of X-autosome synthetic lethals and steriles.

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Lachance, Joseph; Johnson, Norman A; True, John R

2011-11-01

Epistatic interactions are widespread, and many of these interactions involve combinations of alleles at different loci that are deleterious when present in the same individual. The average genetic environment of sex-linked genes differs from that of autosomal genes, suggesting that the population genetics of interacting X-linked and autosomal alleles may be complex. Using both analytical theory and computer simulations, we analyzed the evolutionary trajectories and mutation-selection balance conditions for X-autosome synthetic lethals and steriles. Allele frequencies follow a set of fundamental trajectories, and incompatible alleles are able to segregate at much higher frequencies than single-locus expectations. Equilibria exist, and they can involve fixation of either autosomal or X-linked alleles. The exact equilibrium depends on whether synthetic alleles are dominant or recessive and whether fitness effects are seen in males, females, or both sexes. When single-locus fitness effects and synthetic incompatibilities are both present, population dynamics depend on the dominance of alleles and historical contingency (i.e., whether X-linked or autosomal mutations occur first). Recessive synthetic lethality can result in high-frequency X-linked alleles, and dominant synthetic lethality can result in high-frequency autosomal alleles. Many X-autosome incompatibilities in natural populations may be cryptic, appearing to be single-locus effects because one locus is fixed. We also discuss the implications of these findings with respect to standing genetic variation and the origins of Haldane's rule.

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

Single toxin dose-response models revisited

Energy Technology Data Exchange (ETDEWEB)

Demidenko, Eugene, E-mail: eugened@dartmouth.edu [Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Hanover, NH03756 (United States); Glaholt, SP, E-mail: sglaholt@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States); Kyker-Snowman, E, E-mail: ek2002@wildcats.unh.edu [Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH03824 (United States); Shaw, JR, E-mail: joeshaw@indiana.edu [Indiana University, School of Public & Environmental Affairs, Bloomington, IN47405 (United States); Chen, CY, E-mail: Celia.Y.Chen@dartmouth.edu [Department of Biological Sciences, Dartmouth College, Hanover, NH03755 (United States)

2017-01-01

The goal of this paper is to offer a rigorous analysis of the sigmoid shape single toxin dose-response relationship. The toxin efficacy function is introduced and four special points, including maximum toxin efficacy and inflection points, on the dose-response curve are defined. The special points define three phases of the toxin effect on mortality: (1) toxin concentrations smaller than the first inflection point or (2) larger then the second inflection point imply low mortality rate, and (3) concentrations between the first and the second inflection points imply high mortality rate. Probabilistic interpretation and mathematical analysis for each of the four models, Hill, logit, probit, and Weibull is provided. Two general model extensions are introduced: (1) the multi-target hit model that accounts for the existence of several vital receptors affected by the toxin, and (2) model with a nonzero mortality at zero concentration to account for natural mortality. Special attention is given to statistical estimation in the framework of the generalized linear model with the binomial dependent variable as the mortality count in each experiment, contrary to the widespread nonlinear regression treating the mortality rate as continuous variable. The models are illustrated using standard EPA Daphnia acute (48 h) toxicity tests with mortality as a function of NiCl or CuSO{sub 4} toxin. - Highlights: • The paper offers a rigorous study of a sigmoid dose-response relationship. • The concentration with highest mortality rate is rigorously defined. • A table with four special points for five morality curves is presented. • Two new sigmoid dose-response models have been introduced. • The generalized linear model is advocated for estimation of sigmoid dose-response relationship.

Single-dose volume regulation algorithm for a gas-compensated intrathecal infusion pump.

Science.gov (United States)

Nam, Kyoung Won; Kim, Kwang Gi; Sung, Mun Hyun; Choi, Seong Wook; Kim, Dae Hyun; Jo, Yung Ho

2011-01-01

The internal pressures of medication reservoirs of gas-compensated intrathecal medication infusion pumps decrease when medication is discharged, and these discharge-induced pressure drops can decrease the volume of medication discharged. To prevent these reductions, the volumes discharged must be adjusted to maintain the required dosage levels. In this study, the authors developed an automatic control algorithm for an intrathecal infusion pump developed by the Korean National Cancer Center that regulates single-dose volumes. The proposed algorithm estimates the amount of medication remaining and adjusts control parameters automatically to maintain single-dose volumes at predetermined levels. Experimental results demonstrated that the proposed algorithm can regulate mean single-dose volumes with a variation of 98%. © 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

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.

Lethal modifications of DNA via the transmutation of 32P and 33P incorporated in the genome of the S13 bacteriophage

International Nuclear Information System (INIS)

Cols, P.; Apelgot, S.; Guille, E.

1988-01-01

When circular single-standard DNA of phage S13 is labelled with 32 P or 33 P, the transmutations very efficiently bring about a loss of phage infectiousness (efficiency = 1 for 32 P and 0.73 for 33 P). For both radionuclides, the lethal efficiencies as well as the lethal events are different. In the case of 32 P, the lethal event is the loss of the circular integrity of the DNA molecule, occurring as a consequence of a systematic single strand-break caused by each 32 P decay (100%). Conversely, in the case of 33 P, the lethal events are either a single strand-break (40%) or a local stereochemical modification (33%). The same primary event, the substitution at each 33 P decay of a phosphate by a sulfate molecule, leads to one of these lethal events in relation to the decay site. Moreover, neither the phage adsorption nor its genome injection into bacteria depends on the physical state of the genome, and thus lethality is revealed at only the genetic level. (orig.)

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.

Low-dose cyclophosphamide administered as daily or single dose enhances the antitumor effects of a therapeutic HPV vaccine

Science.gov (United States)

Peng, Shiwen; Lyford-Pike, Sofia; Akpeng, Belinda; Wu, Annie; Hung, Chien-Fu; Hannaman, Drew; Saunders, John R.; Wu, T.-C.

2012-01-01

Although therapeutic HPV vaccines are able to elicit systemic HPV-specific immunity, clinical responses have not always correlated with levels of vaccine-induced CD8+ T cells in human clinical trials. This observed discrepancy may be attributable to an immunosuppressive tumor microenvironment in which the CD8+ T cells are recruited. Regulatory T cells (Tregs) are cells that can dampen cytotoxic CD8+ T-cell function. Cyclophosphamide (CTX) is a systemic chemotherapeutic agent, which can eradicate immune cells, including inhibitory Tregs. The optimal dose and schedule of CTX administration in combination with immunotherapy to eliminate the Treg population without adversely affecting vaccine-induced T-cell responses is unknown. Therefore, we investigated various dosing and administration schedules of CTX in combination with a therapeutic HPV vaccine in a preclinical tumor model. HPV tumor-bearing mice received either a single preconditioning dose or a daily dose of CTX in combination with the pNGVL4a-CRT/E7(detox) DNA vaccine. Both single and daily dosing of CTX in combination with vaccine had a synergistic anti-tumor effect as compared to monotherapy alone. The potent antitumor responses were attributed to the reduction in Treg frequency and increased infiltration of HPV16 E7-specific CD8+ T cells, which led to higher ratios of CD8+/Treg and CD8+/CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs). There was an observed trend toward decreased vaccine-induced CD8+ T-cell frequency with daily dosing of CTX. We recommend a single, preconditioning dose of CTX prior to vaccination due to its efficacy, ease of administration, and reduced cumulative adverse effect on vaccine-induced T cells. PMID:23011589

Low-dose ketoconazole-fluconazole combination versus fluconazole in single doses for the treatment of vaginal candidiasis

Directory of Open Access Journals (Sweden)

Jan Susilo

2011-08-01

Full Text Available Background: Vaginal candidiasis (VC is one of the most common fungal diseases. Candida albicans is the most common causative fungus and has been isolated from more than 80% of specimens obtained from women with VC. Ketoconazole is the first orally active antifungal, the dosage for VC is 200 mg twice daily for 5 days. Fluconazole is the newer oral antifungal, its dosage for VC is a single oral dose of 150 mg. Since fluconazole 150 mg is considerably expensive, a single dose of 100 mg ketoconazole and 40 mg fluconazole in combination has been tested for the treatment of VC. The results showed that from 11 women with confirmed VC, 1-2 weeks after drug administration, the mycological culture was negative in 8 women, positive in 1 woman, and 2 woman lost to follow-up. This promising result led to the present study with the objective to confirm the efficacy and safety of the above combination in a formal clinical trial.Methods: A total of 165 female patients, aged 18 years or older, with the diagnosis of VC from clinical symptoms (pruritus or burning or excessive discharge and positive microscopic smear (pseudohyphae and/or yeast cells were randomized to receive a single dose of either keto-fluco combination (n = 85 or fluconazole (n = 80, and returnedfor follow-up visit on day 8.Results: Among these patients, 39 patients had negative baseline culture, leaving 126 patients eligible for efficacy evaluation. The mycological eradication in the keto-fluco group was 74.5% (41 patients from a total of 55 patients with available mycological culture, while that in the fluconazole group was 70.2% (40 patients from 57 patients with available culture and this difference was not significant. The clinical favorable response (clinical cure and clinical improvement in the keto-fluco arm (n = 60 was 98.3%, while that in the fluconazole group (n = 66 was 100%. Adverse events were found in 5 patients, 3 patients in the keto-fluco group (3/85 = 3.5% and 2

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

Implementation research: reactive mass vaccination with single-dose oral cholera vaccine, Zambia.

Science.gov (United States)

Poncin, Marc; Zulu, Gideon; Voute, Caroline; Ferreras, Eva; Muleya, Clara Mbwili; Malama, Kennedy; Pezzoli, Lorenzo; Mufunda, Jacob; Robert, Hugues; Uzzeni, Florent; Luquero, Francisco J; Chizema, Elizabeth; Ciglenecki, Iza

2018-02-01

To describe the implementation and feasibility of an innovative mass vaccination strategy - based on single-dose oral cholera vaccine - to curb a cholera epidemic in a large urban setting. In April 2016, in the early stages of a cholera outbreak in Lusaka, Zambia, the health ministry collaborated with Médecins Sans Frontières and the World Health Organization in organizing a mass vaccination campaign, based on single-dose oral cholera vaccine. Over a period of 17 days, partners mobilized 1700 health ministry staff and community volunteers for community sensitization, social mobilization and vaccination activities in 10 townships. On each day, doses of vaccine were delivered to vaccination sites and administrative coverage was estimated. Overall, vaccination teams administered 424 100 doses of vaccine to an estimated target population of 578 043, resulting in an estimated administrative coverage of 73.4%. After the campaign, few cholera cases were reported and there was no evidence of the disease spreading within the vaccinated areas. The total cost of the campaign - 2.31 United States dollars (US$) per dose - included the relatively low cost of local delivery - US$ 0.41 per dose. We found that an early and large-scale targeted reactive campaign using a single-dose oral vaccine, organized in response to a cholera epidemic within a large city, to be feasible and appeared effective. While cholera vaccines remain in short supply, the maximization of the number of vaccines in response to a cholera epidemic, by the use of just one dose per member of an at-risk community, should be considered.

Repair of potentially lethal and sublethal radiation damage in x-irradiated ascites tumor cells

International Nuclear Information System (INIS)

Tsuboi, Atsushi; Okamoto, Mieko; Tsuchiya, Takehiko.

1985-01-01

The ability of cells to repair cellular radiation damage during the growth of TMT-3 ascites tumor and the effect of host reaction on the repair ability were examined by using an in vitro assay of cell clonogenicity after in situ irradiation of tumor cells. In single-dose experiments, the repair of potentially lethal radiation damage (PLD) was observed in stationary phase cells (12-day tumor) of the unirradiated host, but not in exponential phase cells (3-day tumor) of the unirradiated host animals. However, if previously irradiated host animals were used, even the exponentially growing tumor cells showed repair of PLD. In two-dose experiments, the ability to repair sublethal radiation damage (SLD) in exponential phase tumor cells was less than that of stationary phase cells in the unirradiated host. In the pre-irradiated host, the extent of the repair in exponential phase cells was somewhat enhanced. These results suggest that irradiation of host animals might suppress a factor that inhibits repair, resulting in enhancement of the repair capability of tumor cells. (author)

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

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.

[Lethal effect after transmutation of 33P incorporated into bacteriophage S 13 and mechanisms of DNA double helix rupture].

Science.gov (United States)

Apelgot, S

1980-04-01

The experiments show the lethal effect of the beta decay of 33P incorporated in DNA of bacteriophage S 13. The lethal efficiency is high, 0.72 at 0 degrees C and 0.55 at--197 degrees C. The presence of a radical scavenger like AET has no influence. It was found previously that for such phages with single-stranded DNA, the lethal efficiency of 32P decay is unity, and that the lethal event is a DNA single-strand break, owing to the high energy of the nucleogenic 32S atom. As the recoil energy of the 33S atom is too low to account for such a break, it is suggested that the reorganization of the phosphate molecule into sulphate is able to bring about a DNA single-strand break with an efficiency as high as 0.7, at 0 degrees C. A model for the DNA double-strand-break produced by a transmutation processes is suggested.

TESS-based dose-response using pediatric clonidine exposures.

Science.gov (United States)

Benson, Blaine E; Spyker, Daniel A; Troutman, William G; Watson, William A

2006-06-01

The toxic and lethal doses of clonidine in children are unclear. This study was designed to determine whether data from the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) could be utilized to determine a dose-response relationship for pediatric clonidine exposure. 3,458 single-substance clonidine exposures in children TESS from January 2000 through December 2003 were examined. Dose ingested, age, and medical outcome were available for 1550 cases. Respiratory arrest cases (n = 8) were classified as the most severe of the medical outcome categories (Arrest, Major, Moderate, Mild, and No effect). Exposures reported as a "taste or lick" (n = 51) were included as a dose of 1/10 of the dosage form involved. Dose ranged from 0.4 to 1980 (median 13) microg/kg. Weight was imputed based on a quadratic estimate of weight for age. Dose certainty was coded as exact (26% of cases) or not exact (74%). Medical outcome (response) was examined via logistic regression using SAS JMP (release 5.1). The logistic model describing medical outcome (P TESS data can provide the basis for a statistically sound description of dose-response for pediatric clonidine poisoning exposures.

Inactivation of CDK2 is synthetically lethal to MYCN over-expressing cancer cells

Science.gov (United States)

Molenaar, Jan J.; Ebus, Marli E.; Geerts, Dirk; Koster, Jan; Lamers, Fieke; Valentijn, Linda J.; Westerhout, Ellen M.; Versteeg, Rogier; Caron, Huib N.

2009-01-01

Two genes have a synthetically lethal relationship when the silencing or inhibiting of 1 gene is only lethal in the context of a mutation or activation of the second gene. This situation offers an attractive therapeutic strategy, as inhibition of such a gene will only trigger cell death in tumor cells with an activated second oncogene but spare normal cells without activation of the second oncogene. Here we present evidence that CDK2 is synthetically lethal to neuroblastoma cells with MYCN amplification and over-expression. Neuroblastomas are childhood tumors with an often lethal outcome. Twenty percent of the tumors have MYCN amplification, and these tumors are ultimately refractory to any therapy. Targeted silencing of CDK2 by 3 RNA interference techniques induced apoptosis in MYCN-amplified neuroblastoma cell lines, but not in MYCN single copy cells. Silencing of MYCN abrogated this apoptotic response in MYCN-amplified cells. Inversely, silencing of CDK2 in MYCN single copy cells did not trigger apoptosis, unless a MYCN transgene was activated. The MYCN induced apoptosis after CDK2 silencing was accompanied by nuclear stabilization of P53, and mRNA profiling showed up-regulation of P53 target genes. Silencing of P53 rescued the cells from MYCN-driven apoptosis. The synthetic lethality of CDK2 silencing in MYCN activated neuroblastoma cells can also be triggered by inhibition of CDK2 with a small molecule drug. Treatment of neuroblastoma cells with roscovitine, a CDK inhibitor, at clinically achievable concentrations induced MYCN-dependent apoptosis. The synthetically lethal relationship between CDK2 and MYCN indicates CDK2 inhibitors as potential MYCN-selective cancer therapeutics. PMID:19525400

Single-dose radiosurgical treatment for hepatic metastases - therapeutic outcome of 138 treated lesions from a single institution

International Nuclear Information System (INIS)

Habermehl, Daniel; Herfarth, Klaus K; Bermejo, Justo Lorenzo; Hof, Holger; Rieken, Stefan; Kuhn, Sabine; Welzel, Thomas; Debus, Jürgen; Combs, Stephanie E

2013-01-01

Local ablative therapies such as stereotactically guided single-dose radiotherapy or helical intensity-modulated radiotherapy (tomotherapy) with high single-doses are successfully applied in many centers in patients with liver metastasis not suitable for surgical resection. This study presents results from more than 10 years of clinical experience and evaluates long-term outcome and efficacy of this therapeutic approach. From 1997 to 2009 a total of 138 intrahepatic tumors of 90 patients were irradiated with single doses of 17 to 30 Gy (median dose 24 Gy). Median age of the patients was 64 years (range 31–89 years). Most frequent underlying tumor histologies were colorectal adenocarcinoma (70 lesions) and breast cancer (27 lesions). In 35 treatment sessions multiple targets were simultaneously irradiated (up to four lesions at once). Local progression-free (PFS) and overall survival (OS) after treatment were investigated using uni- and multiple survival regression models. Median overall survival of all patients was 24.3 months. Local PFS was 87%, 70% and 59% after 6, 12 and 18 months, respectively. Median time to local progression was 25.5 months. Patients with a single lesion and no further metastases at time of RT had a favorable median PFS of 43.1 months according to the Kaplan-Meier estimator. The type of tumor showed a statistical significant influence on local PFS, with a better prognosis for breast cancer histology than for colorectal carcinoma in uni- and multiple regression analysis (p = 0.05). Multiple regression analysis revealed no influence of planning target volume (PTV), patient age and radiation dose on local PFS. Treatment was well tolerated with no severe adverse events. This study confirms safety of SBRT in liver lesions, with 6- and 12 months local control of 87% and 70%. The dataset represents the clinical situation in a large oncology setting, with many competing treatment options and heterogeneous patient characteristics

Hypertrophic Cardiomyopathy After a Single Dose of Dexamethasone in a Preterm Infant

Directory of Open Access Journals (Sweden)

Yusuf Kale

2015-08-01

Full Text Available Dexamethasone is widely used in preterm infants with severe pulmonary disease. Hypertrophic cardiomyopathy (HCM is a transient side effect observed after multiple doses of dexamethasone. We report a preterm infant with myocardial hypertrophy after a single dose of dexamethasone (0.5 mg/kg used to treat laryngeal edema secondary to prolonged intubation. A benign course was observed without left ventricular outflow tract obstruction and with recovery within 4 weeks. Myocardial effects of dexamethasone may be independent of dose and duration of treatment. The risk/benefit ratio must be carefully considered before using even a single dose of dexamethasone in preterm infants.

Coronary vasodilatory action after a single dose of nicorandil

NARCIS (Netherlands)

H. Suryapranata (Harry); P.W.J.C. Serruys (Patrick); P.J. de Feyter (Pim); P.D. Verdouw (Pieter); P.G. Hugenholtz (Paul)

1988-01-01

textabstractCoronary hemodynamics and vasodilatory effects on major epicardial arteries were investigated after a single dose of nicorandil in 22 patients undergoing cardiac catheterization for suspected coronary artery disease. Nicorandil, 20 mg, was administered sublingually to 11 consecutive

Esophageal Toxicity From High-Dose, Single-Fraction Paraspinal Stereotactic Radiosurgery

International Nuclear Information System (INIS)

Cox, Brett W.; Jackson, Andrew; Hunt, Margie; Bilsky, Mark; Yamada, Yoshiya

2012-01-01

Purpose: To report the esophageal toxicity from single-fraction paraspinal stereotactic radiosurgery (SRS) and identify dosimetric and clinical risk factors for toxicity. Methods and Materials: A total of 204 spinal metastases abutting the esophagus (182 patients) were treated with high-dose single-fraction SRS during 2003-2010. Toxicity was scored using the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 4.0. Dose-volume histograms were combined to generate a comprehensive atlas of complication incidence that identifies risk factors for toxicity. Correlation of dose-volume factors with esophageal toxicity was assessed using Fisher’s exact test and logistic regression. Clinical factors were correlated with toxicity. Results: The median dose to the planning treatment volume was 24 Gy. Median follow-up was 12 months (range, 3-81). There were 31 (15%) acute and 24 (12%) late esophageal toxicities. The rate of grade ≥3 acute or late toxicity was 6.8% (14 patients). Fisher’s exact test resulted in significant median splits for grade ≥3 toxicity at V12 = 3.78 cm 3 (relative risk [RR] 3.7, P=.05), V15 = 1.87 cm 3 (RR 13, P=.0013), V20 = 0.11 cm 3 (RR 6, P=0.01), and V22 = 0.0 cm 3 (RR 13, P=.0013). The median split for D2.5 cm 3 (14.02 Gy) was also a significant predictor of toxicity (RR 6; P=.01). A highly significant logistic regression model was generated on the basis of D2.5 cm 3 . One hundred percent (n = 7) of grade ≥4 toxicities were associated with radiation recall reactions after doxorubicin or gemcitabine chemotherapy or iatrogenic manipulation of the irradiated esophagus. Conclusions: High-dose, single-fraction paraspinal SRS has a low rate of grade ≥3 esophageal toxicity. Severe esophageal toxicity is minimized with careful attention to esophageal doses during treatment planning. Iatrogenic manipulation of the irradiated esophagus and systemic agents classically associated with radiation recall reactions are

Single-dose and steady-state pharmacokinetics of diltiazem administered in two different tablet formulations

DEFF Research Database (Denmark)

Christrup, Lona Louring; Bonde, J; Rasmussen, S N

1992-01-01

Single-dose and steady state pharmacokinetics of diltiazem administered in two different oral formulations were assessed with particular reference to rate and extent of absorption. Following single dose administration a significant difference in tmax was observed (2.9 +/- 1.9 and 6.8 +/- 2.6 hr r...

Caracterização da dose letal mínima por irradiação gama para Penicillium citrinum Characterization of minimum lethal dosis of gama irradiation to Penicillium citrinum

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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

γ-ray dose rate effect in DNA double-strand break repair deficient murine cells

International Nuclear Information System (INIS)

Li Liya; Li Peiwen

2002-01-01

Objective: To analyze the dose rate effect and potentially lethal damage repair in DNA double-strand break repair deficient murine cells (SCID) irradiated by γ-ray. Methods: The wild type (CB.17+/+) and SCID cells were exposed to γ-ray at high and low dose rates. The high dose rate exposure was fractionated into two equal doses at 24 h intervals. The survival rates of irradiated cells were calculated by clone-forming analysis. Results: When γ-ray was given to wild type (CB.17+/+) cells in two fractions at 24 h intervals, the survival rate was significantly higher than that when the same total dose was given singly. In contrast, there was no difference in the survival rates between the single and fractionated exposure in SCID cells. SCID cells were more sensitive than CB.17+/+ cells to both low and high dose rates γ-ray exposure for cell killing. The survival rate by low dose rate exposure was significantly higher than that by high dose rate exposure, not only in CB.17+/+ cells but also in SCID cells. Conclusions: SCID cells are deficient in repairing γ-ray induced double-strand breaks. There is dose rate effect in both SCID and CB.17+/+ cells

Single-dose radiation therapy for prevention of heterotopic ossification after total hip arthroplasty

International Nuclear Information System (INIS)

Healy, W.L.; Lo, T.C.; Covall, D.J.; Pfeifer, B.A.; Wasilewski, S.A.

1990-01-01

Single-dose radiation therapy was prospectively evaluated for its efficacy in prevention of heterotopic ossification in patients at high risk after total hip arthroplasty. Thirty-one patients (34 hips) were treated between 1981 and 1988. Risk factors for inclusion in the protocol included prior evidence of heterotopic ossification, ankylosing spondylitis, and diffuse idiopathic skeletal hyperostosis. Patients with hypertrophic osteoarthritis or traumatic arthritis with osteophytes were not included. Operations on 34 hips included 19 primary total and 11 revision total hip arthroplasties and 4 excisions of heterotopic ossification. All patients received radiotherapy to the hip after operation with a single dose of 700 centigray. Radiotherapy is recommended on the first postoperative day. After this single-dose radiation treatment, no patient had clinically significant heterotopic ossification. Recurrent disease developed in two hips (6%), as seen on radiography (grades 2 and 3). This series documents a 100% clinical success rate and a 94% radiographic success rate in preventing heterotopic ossification in patients at high risk after total hip arthroplasty. Single-dose radiotherapy is as effective as other radiation protocols in preventing heterotopic ossification after total hip arthroplasty. It is less expensive and easier to administer than multidose radiotherapy

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

Changes in tumor cell response due to prolonged dose delivery times in fractionated radiation therapy

International Nuclear Information System (INIS)

Paganetti, Harald

2005-01-01

Purpose: Dynamic radiation therapy, such as intensity-modulated radiation therapy, delivers more complex treatment fields than conventional techniques. The increased complexity causes longer dose delivery times for each fraction. The cellular damage after a full treatment may depend on the dose rate, because sublethal radiation damage can be repaired more efficiently during prolonged dose delivery. The goal of this study was to investigate the significance of this effect in fractionated radiation therapy. Methods and Materials: The lethal/potentially lethal model was used to calculate lesion induction rates for repairable and nonrepairable lesions. Dose rate effects were analyzed for 9 different cell lines (8 human tumor xenografts and a C3H10T1/2 cell line). The effects of single-fraction as well as fractionated irradiation for different dose rates were studied. Results: Significant differences can be seen for dose rates lower than about 0.1 Gy/min for all cell lines considered. For 60 Gy delivered in 30 fractions, the equivalent dose is reduced by between 1.3% and 12% comparing 2 Gy delivery over 30 min per fraction with 2 Gy delivery over 1 min per fraction. The effect is higher for higher doses per fraction. Furthermore, the results show that dose rate effects do not show a simple correlation with the α/β ratio for ratios between 3 Gy and 31 Gy. Conclusions: If the total dose delivery time for a treatment fraction in radiation therapy increases to about 20 min, a correction for dose rate effects may have to be considered in treatment planning. Adjustments in effective dose may be necessary when comparing intensity-modulated radiation therapy with conventional treatment plans

Lifetime radiation risks from low-dose rate radionuclides in beagles

International Nuclear Information System (INIS)

Goldman, M.; Rosenblatt, L.S.

1985-01-01

One of the largest, long-term (25-yr) animal studies on the effects of low-dose internal irradiation is almost completed. Some 335 beagles were given continuous exposure to graded 90 Sr [low linear energy transfer (LET)] in their diets (D-dogs) through adulthood. A second group (R-dogs) was given fractionated doses of 225 Ra (high LET) as young adults. A third group of 44 was given a single injection of 90 Sr as adults (S-dogs) to compare single to continuous dosages. All dogs were followed through their lifetimes. Only one of the 848 dogs is still alive. The animals were whole-body counted over their entire life span and were examined frequently for assessment of medical status. There were no acute radiation lethalities. Analyses of the large data base from these dogs have begun and preliminary indications are that 90 Sr, which was tested over a 1500-fold skeletal dose rate range, does not cause significant life shortening at average accumulation skeletal doses of ∼2500 rads (25 Gy) and that a curvilinear dose response curve for life shortening was seen at higher accumulation doses. The data will be discussed in terms of modern epidemiological concepts and quantifications will be related to certain parameters of human risk from acute or chronic radiation exposures

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.

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)

Effective dose comparison between stitched and single FOV in CBCT protocols for complete dental arcade

International Nuclear Information System (INIS)

Soares, Maria Rosangela; Batista, Wilson Otto; Antonio, Patricia Lara de; Caldas, Linda V.E.; Maia, Ana F.

2015-01-01

Objective: The objective of this study was to assess and compare protocols with a single field of view and multiple stitched field of view with a similar clinical purpose by means of effective dose value. Materials and methods: Measurements of absorbed dose were performed with thermoluminescent dosemeters inserted in the position of organs/tissues of a female anthropomorphic phantom and from these values the effective dose was calculated, utilizing weighting factor tissue-ICRP 103 (2007). Results: The results obtained in this study for effective dose are within the range of 43.1 µSv and 111.5 µSv for equipment using protocols with single FOV and in the range of 44.5 µSv and 236.2 µSv for equipments that using protocols with stitched field of view. Conclusions: In terms of the value of effective dose, stitched FOV protocols do not have any advantage over the single field of view protocols. This results suggest the necessity for knowledge of the exposure parameters and effective dose values associated with each image protocol. - Highlights: • The study relies on the comparison of two protocols with similar goals of CBCT: stitched protocols and single protocols. • The stitched FOV protocol is more specific and it is good option when want imaging only of some dental units. • In relation the effective dose, single FOV protocols presents advantage over the stitched FOV protocols. • Know the exposure parameters and effective dose values associated with each image protocol is necessity for request the best CBCT tomographic image

Single-dose and multiple-dose pharmacokinetics and dose proportionality of intravenous and intramuscular HPβCD-diclofenac (Dyloject) compared with other diclofenac formulations.

Science.gov (United States)

Mermelstein, Fred; Hamilton, Douglas A; Wright, Curtis; Lacouture, Peter G; Ramaiya, Atulkumar; Carr, Daniel B

2013-10-01

To evaluate single- and repeated-dose pharmacokinetics (PK) and dose proportionality of hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac compared with Voltarol after intravenous (IV) and intramuscular (IM) administration. Study 1: Single-dose randomized four-way crossover study. Study 2: Multiple-dose randomized three-way crossover study. Clinical research center. Healthy adult volunteers. Study 1: Subjects received HPβCD-diclofenac and Voltarol, IV and IM, with a 5-day washout between treatment periods. Study 2: Subjects received two doses of IV HPβCD-diclofenac and oral Cataflam once every 6 hours for four doses with a 48-hour washout period between treatment periods. Study 1: IV HPβCD-diclofenac had a higher peak plasma concentration (Cmax ) and earlier time to reach maximum plasma concentration (Tmax ), but equivalent plasma exposure (area under the curve from time zero to t [AUC0-t ]) to IV Voltarol. The geometric mean ratio of HPβCD-diclofenac (IV) to Voltarol (IV) for AUC0-t was 106.27%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IM) for AUC0-t was 110.91%. The geometric mean ratio of HPβCD-diclofenac (IV) to HPβCD-diclofenac (IM) for AUC0-t was 101.25%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IV) for AUC0-t was 104.96%. Study 2: Cmax for diclofenac was 2904 and 6031 ng/ml after the first IV dose of 18.75 and 37.5 mg HPβCD-diclofenac, respectively, and was 3090 and 5617 ng/ml after the fourth dose, indicating no accumulation. Plasma exposures to 18.75 mg (866 ng·hour/ml) and 37.5 mg (1843 ng·hour/ml) IV HPβCD-diclofenac bracketed that of oral Cataflam 50 mg (1473 ng·hour/ml). Study 1: Bioavailability in terms of AUC after IV administration was equivalent for HPβCD-diclofenac compared with Voltarol and after IM administration of HPβCD-diclofenac and Voltarol. Bioavailability in terms of AUC after IM administration of HPβCD-diclofenac was equivalent to IV administration of HP�

Single- and multiple-dose pharmacokinetics, pharmacodynamics, and safety of apixaban in healthy Chinese subjects

Directory of Open Access Journals (Sweden)

Cui Y

2013-12-01

Full Text Available Yimin Cui,1 Yan Song,2 Jessie Wang,2 Zhigang Yu,2 Alan Schuster,2 Yu Chen Barrett,2 Charles Frost2 1Peking University First Hospital, Beijing, People's Republic of China; 2Bristol-Myers Squibb, Princeton, NJ, USA Background: The pharmacokinetics (PK, pharmacodynamics (PD, and safety of apixaban were assessed in healthy Chinese subjects in this randomized, placebo-controlled, double-blind, single-sequence, single- and multiple-dose study. Subjects and methods: Eighteen subjects 18–45 years of age were randomly assigned (2:1 ratio to receive apixaban or matched placebo. Subjects received a single 10 mg dose of apixaban or placebo on day 1, followed by 10 mg apixaban or placebo twice daily for 6 days (days 4–9. The PK and PD of apixaban were assessed by collecting plasma samples for 72 hours following the dose on day 1 and the morning dose on day 9, and measuring apixaban concentration and anti-Xa activity. Safety was assessed via physical examinations, vital sign measurements, electrocardiograms, and clinical laboratory evaluations. Results: PK analysis showed similar characteristics of apixaban after single and multiple doses, including a median time to maximum concentration of ~3 hours, mean elimination half-life of ~11 hours, and renal clearance of ~1.2 L/hour. The accumulation index was 1.7, consistent with twice-daily dosing and the observed elimination half-life. Single-dose data predict multiple-dose PK, therefore apixaban PK are time-independent. The relationship between anti-Xa activity and plasma apixaban concentrations appears to be linear. Apixaban was safe and well tolerated, with no bleeding-related adverse events reported. Conclusion: Apixaban was safe and well tolerated in healthy Chinese subjects. Apixaban PK and PD were predictable and consistent with findings from previous studies in Asian and non-Asian subjects. The administration of apixaban does not require any dose modification based on race. Keywords: apixaban, oral

Relationship of DNA repair and chromosome aberrations to potentially lethal damage repair in X-irradiated mammalian cells

International Nuclear Information System (INIS)

Fornace, A.J. Jr.; Nagasawa, H.; Little, J.B.

1980-01-01

By the alkaline elution technique, the repair of x-ray-induced DNA single strand breaks and DNA-protein cross-links was investigated in stationary phase, contact-inhibited mouse cells. During the first hour of repair, approximately 90% of x-ray induced single strand breaks were rejoined whereas most of the remaining breaks were rejoined more slowly during the next 5 h. The number of residual non-rejoined single strand breaks was approximately proportional to the x-ray dose at early repair times. DNA-protein cross-links were removed at a slower rate - T 1/2 approximately 10 to 12 h. Cells were subcultured at low density at various times after irradiation and scored for colony survival, and chromosome aberrations in the first mitosis after sub-culture. Both cell lethality and the frequency of chromosome aberrations decreased during the first several hours of repair, reaching a minimum level by 6 h; this decrease correlated temporally with the repair of the slowly rejoining DNA strand breaks. The possible relationship of DNA repair to changes in survival and chromosome aberrations is discussed

Management of urinary tract infections in pregnancy: a review with comments on single dose therapy.

Science.gov (United States)

Zinner, S H

1992-01-01

Most investigators agree that the adverse effects of urinary tract infections in pregnancy can be abrogated by effective early detection and treatment. However, the optimal methods for screening and treatment remain controversial. Although single-dose therapy has not been applied to pregnant women with acute pyelonephritis, most but not all studies which have compared single-dose with longer courses of beta-lactam or other antibiotics in pregnant asymptomatic bacteriuric women have shown no differences in outcome. This paper reviews recent trials of single-dose treatment of bacteriuria in pregnant women.

Marrow toxicity of fractionated vs. single dose total body irradiation is identical in a canine model

International Nuclear Information System (INIS)

Storb, R.; Raff, R.F.; Graham, T.; Appelbaum, F.R.; Deeg, H.J.; Schuening, F.G.; Shulman, H.; Pepe, M.

1993-01-01

The authors explored in dogs the marrow toxicity of single dose total body irradiation delivered from two opposing 60 Co sources at a rate of 10 cGy/min and compared results to those seen with total body irradiation administered in 100 cGy fractions with minimum interfraction intervals of 6 hr. Dogs were not given marrow transplants. They found that 200 cGy single dose total body irradiation was sublethal, with 12 of 13 dogs showing hematopoietic recovery and survival. Seven of 21 dogs given 300 cGy single dose total body irradiation survived compared to 6 of 10 dogs given 300 cGy fractionated total body irradiation. One of 28 dogs given 400 cGy single dose total body irradiation survived compared to none of six given fractionated radiation. With granulocyte colony stimulating factor (GCSF) administered from day 0-21 after 400 cGy total body irradiation, most dogs survived with hematological recovery. Because of the almost uniform success with GCSF after 400 cGy single dose total body irradiation, a study of GCSF after 400 cGy fractionated total body irradiation was deemed not to be informative and, thus, not carried out. Additional comparisons between single dose and fractionated total body irradiation were carried out with GCSF administered after 500 and 600 cGy of total body irradiation. As with lower doses of total body irradiation, no significant survival differences were seen between the two modes of total body irradiation, and only 3 of 26 dogs studied survived with complete hematological recovery. Overall, therefore, survival among dogs given single dose total body irradiation was not different from that of dogs given fractionated total body irradiation (p = .67). Similarly, the slopes of the postirradiation declines of granulocyte and platelet counts and the rates of their recovery in surviving dogs given equal total doses of single versus fractionated total body irradiation were indistinguishable. 24 refs., 3 figs., 2 tabs

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

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.

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

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.

Response of mouse tongue epithelium to single doses of bleomycin and radiation

International Nuclear Information System (INIS)

Dorr, W.; Hirler, E.; Honig, M.

1993-01-01

Both bleomycin (BLM) and local X-irradiation (25 kV) induce denudation in the tongue epithelium of the C3H-Neuherberg mouse in a dose-dependent manner. In the present study the effect of BLM alone and of combined single doses of drug and radiation were studied using the incidence of epithelial denudation as the end-point. In 'time-line' experiments, 8 mg/kg BLM were given before or after graded doses of X-rays. BLM treatment required a reduction of the radiation dose (ED 50 ) from 15 Gy to 5-7 Gy, independent of sequence or time interval. In contrast, the time course of the response was clearly dependent on the treatment interval. Latency decreased when the drug was injected less than 2 h before irradiation with minimum latency observed at 30 min. Isobologram analysis of experiments with varying combinations of X-rays and BLM demonstrated that small drug doses were relatively more effective than larger doses, suggesting an upward concavity of the BLM dose-effective curve in vivo, i.e. a 'negative shoulder' of the curve in the low dose region. In contrast to the response to X-rays alone, which has a constant latent time to ulcer of 10 days, the latency in combined treatment was clearly shortened with increasing drug dose and at high doses eventually approximated the epithelial turnover time of 5 days. The data suggest that BLM both as a single agent and in combination with X-rays reduced the probability of abortive divisions and through this effect shortened the latent time to epithelial denudation. (author)

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...

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)

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)

Repair of sublethal damage in mammalian cells irradiated at ultrahigh dose rates

International Nuclear Information System (INIS)

Gerweck, L.E.; Epp, E.R.; Michaels, H.B.; Ling, C.C.; Peterson, E.C.

1979-01-01

The lethal response of asynchronous Chinese hamster ovary (CHO) cells exposed to single and split doses of radiation at conventional or ultrahigh dose rates has been examined to determine whether repair of sublethal damage occurs in cells irradiated at ultrahigh dose rates. The high-intensity irradiations were performed with electrons delivered in single 3-nsec pulses from a 600-kV field emission source under medium-removed, thin-layer conditions. Conventional dose-rate experiments were done under identical thin-layer conditions with 50-kVp x rays, or under full-medium conditions with 280-kVp x rays. Oxygenated cells were irradiated and maintained at 22 to 24 0 C between exposures. Survival did not increase as the time between two doses of pulsed electrons increased from 0 to 4 min, indicating no evidence of fast repair. However, increased survival was observed when 30 to 90 min was allowed to elapse between the split doses. The half-time for maximum repair was approx. = 30 min irrespective of the exposure conditions and radiation modality used. Observed repair ratios increased from approx. = 2 to 4 as the single-dose surviving fraction decreased from 10 -2 to 5 x 10 -4 . Over this survival range the repair ratios, measured at the same value of surviving fraction, were independent of dose rate. The observed repair ratios imply that the shoulder regions of the nonfractionated x-ray and pulsed-electron survival curves were not completely restored between the split doses. However, the fraction of the shoulder restored between split doses of radiation was dose-rate-independent. It is concluded that sublethal damage can be repaired in oxygenated CHO cells irradiated at dose rates of the order of 10 11 rad/sec

Single-dose intravenous iron infusion or oral iron for treatment of fatigue after postpartum haemorrhage

DEFF Research Database (Denmark)

Holm, C; Thomsen, L L; Norgaard, A

2017-01-01

BACKGROUND AND OBJECTIVES: To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage. MATERIALS AND METHODS: Single-centre, open-label, ran......BACKGROUND AND OBJECTIVES: To evaluate the clinical efficacy of a single-dose intravenous infusion of iron isomaltoside compared with current treatment practice with oral iron measured by physical fatigue in women after postpartum haemorrhage. MATERIALS AND METHODS: Single-centre, open...

Dose/dose-rate responses of shrimp larvae to UV-B radiation

International Nuclear Information System (INIS)

Damkaer, D.M.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm -2 sub([DNA]) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm -2 sub([DNA]). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation. (orig.)

Dose/dose-rate responses of shrimp larvae to UV-B radiation

Energy Technology Data Exchange (ETDEWEB)

Damkaer, D.M.; Dey, D.B.; Heron, G.A.

1981-01-01

Previous work indicated dose-rate thresholds in the effects of UV-B on the near-surface larvae of three shrimp species. Additional observations suggest that the total dose response varies with dose-rate. Below 0.002 Wm/sup -2/sub((DNA)) irradiance no significant effect is noted in activity, development, or survival. Beyond that dose-rate threshold, shrimp larvae are significantly affected if the total dose exceeds about 85 Jm/sup -2/sub((DNA)). Predictions cannot be made without both the dose-rate and the dose. These dose/dose-rate thresholds are compared to four-year mean dose/dose-rate solar UV-B irradiances at the experimental site, measured at the surface and calculated for 1 m depth. The probability that the shrimp larvae would receive lethal irradiance is low for the first half of the season of surface occurrence, even with a 44% increase in damaging UV radiation.

The frequency of allelic lethals and complementation maps in natural populations of drosophila melanogaster from Mexico

Directory of Open Access Journals (Sweden)

Salceda Victor M.

2004-01-01

Full Text Available Departing from a previous study on the genetic loads affecting the second chromosome of Drosophila melanogaster in four natural populations, 171 lethal chromosomes were recovered and maintained as a balanced stocks in the condition Cy L / 1 (l=lethal; of those lethais 24 correspond to population A, 50 to populations B and C and 47 to population D. later on an intra-population allelism test for the four populations was performed for each one. A total of 3807 inter lethal crosses were done yielding a total of i 10 allelic combinations, from them the respective percentage of allelism for each population was calculated and they are as follow: 3.98 % for population A, 1.80 % for population B, 3.67 % for population C and 2.96 % for population D. the observed values for the frequency of allelism in these populations are not significantly different from those reported by other authors in similar studies in natural and/or experimental populations. Beside these values the frequency for singles, doubles, triplets and even quadruplets present in each population were determined, they shown the presence of various complementation maps due to the clustering of few different lethals: also a large complementation map formed by a large cluster involving the presence of 26 different lethals found in population D all of them combined constituting a single unit was found.

A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin.

Science.gov (United States)

Belda, Walter; Di Chiacchio, Nilton G; Di Chiacchio, Nilton; Romiti, Ricardo; Criado, Paulo R; Velho, Paulo Eduardo N Ferreira

2009-06-01

A study was conducted in São Paulo, Brazil, to compare azithromycin with thiamphenicol for the single-dose treatment of chancroid. In all, 54 men with chancroid were tested. The etiology was determined by clinical characterization and direct bacterioscopy with Gram staining. None of the patients had positive serology or dark-field examination indicating active infection with Treponema pallidum. Genital infections due to Neisseria gonorrhoeae and herpes simplex virus were excluded by polymerase chain reaction testing. For 54 patients with chancroid, cure rates with single-dose treatment were 73% with azithromycin and 89% with thiamphenicol. HIV seropositivity was found to be associated with treatment failure (p=0.001). The treatment failed in all HIV positive patients treated with azithromycin (p=0.002) and this drug should be avoided in these co-infected patients. In the view of the authors, thiamphenicol is the most indicated single-dose regimen for chancroid treatment.

A Cohort Study of Preoperative Single Dose Versus Four Doses of Antibiotics for Patients With Non-Complicated Acute Appendicitis

Directory of Open Access Journals (Sweden)

Salah H. Al Janaby

2017-02-01

Full Text Available Objective: To Test the efficacy of single preoperative dose of Cefotaxime 1gm and Metronidazole 500mg in reducing the surgical site infections (SSIs after open appendectomy in patients with non-complicated appendicitis (NCA Place and Duration of Study: Al Hilla General Teaching Hospital, Babel Governorate-Iraq, from January 2013 to January 2014. Patients & Methods: 100 patients, who underwent appendectomy for NCA and fulfilled the selection criteria, were randomized into two groups. The patients in group A received a single dose of pre-operative antibiotics (Cefotaxime sodium and metronidazole, while the group B patients received three more dose of the same antibiotics postoperatively. Patients of both groups were followed-up for 30 days to assess the postoperative infective complications. Results: Group A had 48, while group B comprised of 52 patients. The groups were comparable in the baseline characteristics. Statistically, P value in rates of SSIs between both the groups was 0.9182. None of the patients developed intra-abdominal collection. Conclusion: Single dose of pre-operative antibiotics (Cefotaxime and metronidazole was sufficient in reducing the SSIs after appendectomy for NPA. Postoperative antibiotics did not add an appreciable clinical benefit in these patients. Key words: Preoperative antibiotics, Appendectomy, Surgical site infection, Non-complicated appendicitis Abbreviations: SSI: Surgical Site Infection, NCA: non-complicated appendicitis CDC Center of Disease Control.

Single and 30 fraction tumor control doses correlate in xenografted tumor models: implications for predictive assays

International Nuclear Information System (INIS)

Gerweck, Leo E.; Dubois, Willum; Baumann, Michael; Suit, Herman D.

1995-01-01

Purpose/Objective: In a previous publication we reported that laboratory assays of tumor clonogen number, in combination with intrinsic radiosensitivity measured in-vitro, accurately predicted the rank-order of single fraction 50% tumor control doses, in six rodent and xenografted human tumors. In these studies, tumor hypoxia influenced the absolute value of the tumor control doses across tumor types, but not their rank-order. In the present study we hypothesize that determinants of the single fraction tumor control dose, may also strongly influence the fractionaled tumor control doses, and that knowledge of tumor clonogen number and their sensitivity to fractionated irradiation, may be useful for predicting the relative sensitivity of tumors treated by conventional fractionated irradiation. Methods/Materials: Five tumors of human origin were used for these studies. Special care was taken to ensure that all tumor control dose assays were performed over the same time frame, i.e., in-vitro cells of a similar passage were used to initiate tumor sources which were expanded and used in the 3rd or 4th generation. Thirty fraction tumor control doses were performed in air breathing mice, under normal blood flow conditions (two fractions/day). The results of these studies have been previously published. For studies under uniformly (clamp) hypoxic conditions, tumors arising from the same transplantation were randomized into single or fractionated dose protocols. For estimation of the fractionated TCD50 under hypoxic conditions, tumors were exposed to six 5.4 Gy fractions (∼ 2 Gy equivalent under air), followed by graded 'top-up' dose irradiation for determination of the TCD50; the time interval between doses was 6-9 hours. The single dose equivalent of the six 5.4 Gy doses was used to calculate an extrapolated 30 fraction hypoxic TCD50. Results: Fractionation substantially increased the dose required for tumor control in 4 of the 5 tumors investigated. For these 4 tumors

Differential replication of Foot-and-mouth disease viruses in mice determine lethality.

Science.gov (United States)

Cacciabue, Marco; García-Núñez, María Soledad; Delgado, Fernando; Currá, Anabella; Marrero, Rubén; Molinari, Paula; Rieder, Elizabeth; Carrillo, Elisa; Gismondi, María Inés

2017-09-01

Adult C57BL/6J mice have been used to study Foot-and-mouth disease virus (FMDV) biology. In this work, two variants of an FMDV A/Arg/01 strain exhibiting differential pathogenicity in adult mice were identified and characterized: a non-lethal virus (A01NL) caused mild signs of disease, whereas a lethal virus (A01L) caused death within 24-48h independently of the dose used. Both viruses caused a systemic infection with pathological changes in the exocrine pancreas. Virus A01L reached higher viral loads in plasma and organs of inoculated mice as well as increased replication in an ovine kidney cell line. Complete consensus sequences revealed 6 non-synonymous changes between A01L and A10NL genomes that might be linked to replication differences, as suggested by in silico prediction studies. Our results highlight the biological significance of discrete genomic variations and reinforce the usefulness of this animal model to study viral determinants of lethality. Copyright © 2017 Elsevier Inc. All rights reserved.

Efficacy of various single-dose regimens of ceftriaxone in ...

African Journals Online (AJOL)

1990-08-18

Aug 18, 1990 ... The therapeutic efficacy of single intramuscular doses of ceftriaxone (Rocephin; Roche) (62,S, 125 and 250 mg), admini- stered without probenecid, was evaluated in 167 adult males with uncomplicated acute gonococcal urethritis. Cure rates of 100% were achieved at 62,5 mg and 250 mg. In the 125 mg.

Protective effect of hypoxia in the ram testis during single and split-dose X-irradiation

International Nuclear Information System (INIS)

Vliet, J. van; Wensing, C.J.G.; Bootsma, A.L.; Peperzeel, H.A. van; Schipper, J.

1988-01-01

Spertogonial stem-cell survival in the ram was studied after single (6Gy) and split-dose X-irradiation both under normal and hypoxic conditions. Hypoxia was induced by inflation of an occluder implanted around the testicular artery. The occluders were inflated about 10 min before irradiation and deflated immediately after. Stem-cell survival was measured at 5 or 7 weeks after irradiation by determination of the Repopulation Index (RI) in histological testis sections. The RI-values after fractionated irradiation were only half those after single dose irradiation. Hypoxia had a protective effect on the stem-cell survival. After split-dose irradiation under hypoxic conditions two times more stem cells survived than under normal oxic conditions; the RI-values increased from 34% (oxic) to 68% (hypoxic). This effect of hypoxia was also found after single dose irradiation where the RI-values increased from 68% (oxic) to 84% (hypoxic). The development of the epithelium in repopulated tubules was also studied. Under hypoxia, a significantly higher fraction of tubules with complete epithelium was found after single (38 vs. 4%) as well as after split-dose irradiation (12 vs. 0%)

Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

Science.gov (United States)

Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

2017-02-01

This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

The D1 method: career dose estimation from a combination of historical monitoring data and a single year's dose data

International Nuclear Information System (INIS)

Sont, W.N.

1995-01-01

A method is introduced to estimate career doses from a combination of historical monitoring data and a single year's dose data. This method, called D1 eliminates the bias arising from incorporating historical dose data from times when occupational doses were generally much higher than they are today. Doses calculated by this method are still conditional on the preservation of the status quo in the effectiveness of radiation protection. The method takes into account the variation of the annual dose, and of the probability of being monitored, with the time elapsed since the start of a career. It also allows for the calculation of a standard error of the projected career dose. Results from recent Canadian dose data are presented. (author)

Single dose (400 mg) versus 7 day (200 mg) daily dose itraconazole in the treatment of tinea versicolor: a randomized clinical trial.

Science.gov (United States)

Wahab, M A; Ali, M E; Rahman, M H; Chowdhury, S A; Monamie, N S; Sultana, N; Khondoker, L

2010-01-01

Tinea (pityriasis) versicolor is a superficial fungal infection and one of the most commonly found pigmentary disorders of skin caused by the yeast Malassezia. Multiple topical as well as systemic therapies are available for treatment. Systemic therapies are used for extensive disease, frequent relapse or where topical agents have failed. The aim that translates the rationale of the study was to compare the efficacy, safety, tolerability and cost effectiveness of single dose 400mg versus 7 day 200 mg daily dose of itraconazole in the treatment of tinea versicolor. A clinical study was done to compare the efficacy of single dose (400 mg) of itraconazole and 7 day 200 mg daily dose of itraconazole in the treatment of extensive tinea versicolor. Total 60 patients (aged 18-50 years) were selected for the study during the period of June 2007 to May 2008 in the department of Dermatology of three different hospitals in Bangladesh. Cases having with extensive involvement, diagnosed clinically and confirmed by wood's lamp and KOH microscopy were taken. Patients were randomly allocated into equal groups. Group A was given single dose 400 mg itraconazole and Group B was given 7 day 200 mg daily itraconazole. Fifty three (88%) male and 7(12%) female were included in the study. The mean age of group A was 32.37+/-9 years and in group B 33.23+/-8 years. The mean duration of the disease in group A was 2.63+/-2 months and 2.76+/-2 months in group B. In group A clinical responders was found cure 22(73.33%) and improvement 5(16.33%) and in group B it was found cure 24(79.99%) and improvement 4(13.33%). The measure at the End point (EP1) equals to 90% response and in-group B it was found cure 24 (79.99%) and improvement 4(13.33%). (Here the End point EP2) equals to 93.33%. The EP clinical analysis however shows 91.66% response. Both single dose and 7 day daily dose of itraconazole can be effective in the treatment of tinea versicolor with extensive involvement but single dose appears

TESS-based dose-response using pediatric clonidine exposures

International Nuclear Information System (INIS)

Benson, Blaine E.; Spyker, Daniel A.; Troutman, William G.; Watson, William A.

2006-01-01

Objective: The toxic and lethal doses of clonidine in children are unclear. This study was designed to determine whether data from the American Association of Poison Control Centers Toxic Exposure Surveillance System (TESS) could be utilized to determine a dose-response relationship for pediatric clonidine exposure. Methods: 3458 single-substance clonidine exposures in children <6 years of age reported to TESS from January 2000 through December 2003 were examined. Dose ingested, age, and medical outcome were available for 1550 cases. Respiratory arrest cases (n = 8) were classified as the most severe of the medical outcome categories (Arrest, Major, Moderate, Mild, and No effect). Exposures reported as a 'taste or lick' (n = 51) were included as a dose of 1/10 of the dosage form involved. Dose ranged from 0.4 to 1980 (median 13) μg/kg. Weight was imputed based on a quadratic estimate of weight for age. Dose certainty was coded as exact (26% of cases) or not exact (74%). Medical outcome (response) was examined via logistic regression using SAS JMP (release 5.1). Results: The logistic model describing medical outcome (P < 0.0001) included Log dose/kg (P 0.0000) and Certainty (P = 0.045). Conclusion: TESS data can provide the basis for a statistically sound description of dose-response for pediatric clonidine poisoning exposures

A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin

Directory of Open Access Journals (Sweden)

Walter B. Junior

Full Text Available A study was conducted in São Paulo, Brazil, to compare azithromycin with thiamphenicol for the single-dose treatment of chancroid. In all, 54 men with chancroid were tested. The etiology was determined by clinical characterization and direct bacterioscopy with Gram staining. None of the patients had positive serology or dark-field examination indicating active infection with Treponema pallidum. Genital infections due to Neisseria gonorrhoeae and herpes simplex virus were excluded by polymerase chain reaction testing. For 54 patients with chancroid, cure rates with single-dose treatment were 73% with azithromycin and 89% with thiamphenicol. HIV seropositivity was found to be associated with treatment failure (p=0.001. The treatment failed in all HIV positive patients treated with azithromycin (p=0.002 and this drug should be avoided in these co-infected patients. In the view of the authors, thiamphenicol is the most indicated single-dose regimen for chancroid treatment.

Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae

International Nuclear Information System (INIS)

Toyoshima, Yoshiyuki; Takahashi, Akemi; Tanaka, Hisaki; Watanabe, Jun; Mogi, Yoshinobu; Yamazaki, Tatsuo; Hamada, Ryoko; Iwashita, Kazuhiro; Satoh, Katsuya; Narumi, Issay

2012-01-01

Highlights: ► We investigated the effects of different LET radiation in A. oryzae. ► Both γ-rays and ion beams induced base substitutions, frameshifts, deletions. ► Both γ-rays and ion beams induced genome-wide large-scale mutations in A. oryzae. ► Some differences in the types and frequencies of mutations were found. ► Our results provide new basic insights into the mutation breeding of A. oryzae. - Abstract: 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 121 keV/μm. The 12 C 5+ ion beams had a 3.6-times higher lethal effect than low-LET (0.2 keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. 12 C 6+ ion beams with an LET of 86 keV/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 700 Gy. In the dose range from 0 to 700 Gy, 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 400 Gy. 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 >2 bp was generally low

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)

Lethal Effect of Gamma Irradiation on the Potato Tuber Moth, Phthorimaea operculella (Zeller) and its Effect on Certain Physicochemical Properties of Potato Tubers

International Nuclear Information System (INIS)

Aly, G.M.; Rizk, S. A.; Abdalla, R.S.; Sobeiha, A.M.K.; Dahroug, S.M.

2012-01-01

Exposure of 4-day-old eggs of Phthorimaea operculella (Zeller) to a dose level of 800 Gy of gamma radiation caused complete mortality and prevent egg hatching after 4 days from exposure to radiation. This dose level was considered as the lethal dose for the egg stage. The dose levels of 700 and 2800 Gy were considered lethal for the full grown larvae after periods of 9 and 1 days elapsed respectively from exposure to gamma radiation .The percent larval mortality increased with the increase of both the dose level applied and the time elapsed after exposure to gamma radiation. Irradiation of full grown pupae at the dose level 1900 Gy resulted in a complete reduction of adult emergence, reached 100 % . It could be concluded that gamma irradiation with a dose level 2800 Gy caused complete mortality to different stages of Phthorimaea operculella. Moreover, the physical and chemical properties of irradiated potato tubers did not significantly differ as compared to unirradiated tubers .This obtained, fatal irradiation dose did not exceed the safe limits recommended by the international organization FAO/WHO.

Five-Year Outcomes of High-Dose Single-Fraction Spinal Stereotactic Radiosurgery

International Nuclear Information System (INIS)

Moussazadeh, Nelson; Lis, Eric; Katsoulakis, Evangelia; Kahn, Sweena; Svoboda, Marek; DiStefano, Natalie M.; McLaughlin, Lily; Bilsky, Mark H.; Yamada, Yoshiya; Laufer, Ilya

2015-01-01

Purpose: To characterize local tumor control and toxicity risk in very long-term survivors (>5 years) after high-dose spinal image guided, intensity modulated radiation therapy delivered as single-dose stereotactic radiosurgery (SRS). Previously published spinal SRS outcome analyses have included a heterogeneous population of cancer patients, mostly with short survival. This is the first study reporting the long-term tumor control and toxicity profiles after high-dose single-fraction spinal SRS. Methods and Materials: The study population included all patients treated from June 2004 to July 2009 with single-fraction spinal SRS (dose 24 Gy) who had survived at least 5 years after treatment. The endpoints examined included disease progression, surgical or radiation retreatment, in-field fracture development, and radiation-associated toxicity, scored using the Radiation Therapy Oncology Group radiation morbidity scoring criteria and the Common Terminology Criteria for Adverse Events, version 4.0. Local control and fracture development were assessed using Kaplan-Meier analysis. Results: Of 278 patients, 31 (11.1%), with 36 segments treated for spinal tumors, survived at least 5 years after treatment and were followed up radiographically and clinically for a median of 6.1 years (maximum 102 months). The histopathologic findings for the 5-year survivors included radiation-resistant metastases in 58%, radiation-sensitive metastases in 22%, and primary bone tumors in 19%. In this selected cohort, 3 treatment failures occurred at a median of 48.6 months, including 2 recurrences in the radiation field and 1 patient with demonstrated progression at the treatment margins. Ten lesions (27.8%) were associated with acute grade 1 cutaneous or gastrointestinal toxicity. Delayed toxicity ≥3 months after treatment included 8 cases (22.2%) of mild neuropathy, 2 (5.6%) of gastrointestinal discomfort, 8 (22.2%) of dermatitides, and 3 (8.3%) of myalgias/myositis. Thirteen

Five-Year Outcomes of High-Dose Single-Fraction Spinal Stereotactic Radiosurgery

Energy Technology Data Exchange (ETDEWEB)

Moussazadeh, Nelson [Division of Neurological Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, New York (United States); Lis, Eric [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Katsoulakis, Evangelia [Department of Radiation Oncology, New York Methodist Hospital, Brooklyn, New York (United States); Kahn, Sweena; Svoboda, Marek; DiStefano, Natalie M.; McLaughlin, Lily [Division of Neurological Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Bilsky, Mark H. [Division of Neurological Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, New York (United States); Yamada, Yoshiya [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Laufer, Ilya, E-mail: lauferi@mskcc.org [Division of Neurological Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, New York (United States)

2015-10-01

Purpose: To characterize local tumor control and toxicity risk in very long-term survivors (>5 years) after high-dose spinal image guided, intensity modulated radiation therapy delivered as single-dose stereotactic radiosurgery (SRS). Previously published spinal SRS outcome analyses have included a heterogeneous population of cancer patients, mostly with short survival. This is the first study reporting the long-term tumor control and toxicity profiles after high-dose single-fraction spinal SRS. Methods and Materials: The study population included all patients treated from June 2004 to July 2009 with single-fraction spinal SRS (dose 24 Gy) who had survived at least 5 years after treatment. The endpoints examined included disease progression, surgical or radiation retreatment, in-field fracture development, and radiation-associated toxicity, scored using the Radiation Therapy Oncology Group radiation morbidity scoring criteria and the Common Terminology Criteria for Adverse Events, version 4.0. Local control and fracture development were assessed using Kaplan-Meier analysis. Results: Of 278 patients, 31 (11.1%), with 36 segments treated for spinal tumors, survived at least 5 years after treatment and were followed up radiographically and clinically for a median of 6.1 years (maximum 102 months). The histopathologic findings for the 5-year survivors included radiation-resistant metastases in 58%, radiation-sensitive metastases in 22%, and primary bone tumors in 19%. In this selected cohort, 3 treatment failures occurred at a median of 48.6 months, including 2 recurrences in the radiation field and 1 patient with demonstrated progression at the treatment margins. Ten lesions (27.8%) were associated with acute grade 1 cutaneous or gastrointestinal toxicity. Delayed toxicity ≥3 months after treatment included 8 cases (22.2%) of mild neuropathy, 2 (5.6%) of gastrointestinal discomfort, 8 (22.2%) of dermatitides, and 3 (8.3%) of myalgias/myositis. Thirteen

Comparison of single-grain and small-aliquot OSL dose estimates in < 3000 years old river sediments from South India

DEFF Research Database (Denmark)

Thomas, P.J.; Jain, M.; Juyal, N.

2005-01-01

We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there wa......We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples......, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from similar to 1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons...... perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal. (c) 2004 Elsevier Ltd. All rights reserved....

The effects of single and fractionated irradiation of the trunk in rats

International Nuclear Information System (INIS)

Giri, P.G.S.; Kimler, B.F.; Giri, U.P.; Cox, G.G.; Reddy, E.K.

1985-01-01

The effect of whole trunk irradiation on the development of functional damage was investigated in rats. Rats were restrained without anesthesia such that only the trunk (from clavicle to pelvic girdle) was irradiated with a Cs-137 irradiator at a dose rate of 8.5 Gy/min. Rats received single doses of 9.4, 11.7, 14.1, or 16.4 Gy; or total doses of 11.7, 14.1, 16.4, 18.8, or 21.1 Gy in two equal fractions separated by 4-6 hr. Except for the highest dose in both schedules, there was no lethality; 16.4 Gy reduced survival to 45% and 21.1 Gy in two fractions reduced survival to 77% by day 150. From day 10 to day 150 there was a dose-dependent reduction in weight for both schedules, with the two-dose response displaced from the single dose response by ≅ 6 Gy. A whole-body plethysmograph was used to measure respiration frequency. There was no increase in respiration frequency compared to control animals, except for the highest single dose - 16.4 Gy producing an increase that was manifested from 10 to 150 days. The authors conclude that, in this rat trunk irradiation model, fractionation into two equal doses separated by 4-6 hr produces a sparing effect of ≅ 6 Gy as measured by delay in weight gain (presumably a result of irradiation of the abdomen); and ≥ 6 Gy as measured by survival and increased respiration frequency (a result of irradiation of the thorax)

Correlation between induced embryo toxicity and absorption dose of enriched uranium in testes

International Nuclear Information System (INIS)

Zhu Shoupeng; Lun Mingyue

1996-01-01

Doses of enriched uranium in testes inducing dominant lethality and skeletal abnormalities in offsprings are estimated. When intra-testicular injection dose is 0.4∼60 μg enriched uranium; from intake to insemination, testes could receive 9.14 x 10 -5 ∼1.38 x 10 -2 Gy radiation dose. Experimental results show that with the increase in the absorption dose, the number of living fetuses in a litter decreases, dominant lethality and skeletal abnormalities rise. It should be noted that relationship between the injected dose (I in μg) and the incidence of dominant skeletal abnormalities (S in %) in the offsprings can be represented by equation: S = 28.84 + 0.84I

Correlation between induced embryo toxicity and absorption dose of enriched uranium in testes

Energy Technology Data Exchange (ETDEWEB)

Shoupeng, Zhu; Mingyue, Lun [Suzhou Medical Coll., JS (China)

1996-08-01

Doses of enriched uranium in testes inducing dominant lethality and skeletal abnormalities in offsprings are estimated. When intra-testicular injection dose is 0.4{approx}60 {mu}g enriched uranium; from intake to insemination, testes could receive 9.14 x 10{sup -5}{approx}1.38 x 10{sup -2} Gy radiation dose. Experimental results show that with the increase in the absorption dose, the number of living fetuses in a litter decreases, dominant lethality and skeletal abnormalities rise. It should be noted that relationship between the injected dose (I in {mu}g) and the incidence of dominant skeletal abnormalities (S in %) in the offsprings can be represented by equation: S = 28.84 + 0.84I.

Comparison of single-grain and small-aliquot OSL dose estimates in <3000 years old river sediments from South India

International Nuclear Information System (INIS)

Thomas, P.J.; Jain, M.; Juyal, N.; Singhvi, A.K.

2005-01-01

We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from ∼1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons for the discrepancy between single-grain and small-aliquot dose estimates are discussed. Although there is no satisfactory explanation for this discrepancy, we speculate that the difference in the stimulation wavelengths, 470+/-30nm in the case of single-aliquot and 532nm in the case of single grains, could perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal

Single-dose Rituximab Therapy for Refractory Idiopathic Membranous Nephropathy: A Single-center Experience

OpenAIRE

Katsuno, Takayuki; Ozaki, Takenori; Kim, Hangsoo; Kato, Noritoshi; Suzuki, Yasuhiro; Akiyama, Shinichi; Ishimoto, Takuji; Kosugi, Tomoki; Tsuboi, Naotake; Ito, Yasuhiko; Maruyama, Shoichi

2017-01-01

To date, a recognized treatment for refractory membranous nephropathy (MN) has not been established. Recently, several reports have indicated the efficacy of rituximab as a novel treatment option. However, only a few published accounts exist of rituximab therapy for idiopathic MN (IMN) in the Asian population. We present the cases of three IMN patients who were treated with single-dose rituximab after they showed no response to conventional therapies, including corticosteroids, cyclosporine, ...

Improved long-term survival after intra-operative single high-dose ATG-Fresenius induction in renal transplantation: a single centre experience.

Science.gov (United States)

Kaden, Jürgen; May, Gottfried; Völp, Andreas; Wesslau, Claus

2009-01-01

In organ grafts donor-specific sensitization is initiated immediately after revascularization. Therefore, in 1990 we introduced the intra-operative single high-dose ATG-Fresenius (ATG-F) induction in addition to standard triple drug therapy (TDT) consisting of steroids, azathioprine and cyclosporin. A total of 778 first renal transplantations from deceased donors, performed between 1987 and 1998, were included in this evaluation. This retrospective analysis of clinic records and electronic databases presents data of all recipients of first kidney grafts who received two different ATG-F inductions (1(st) group: 9 mg/kg body weight as single high-dose intra-operatively, n=484; 2(nd) group: 3 mg/kg body weight on 7 or 8 consecutive days as multiple-dose starting also intra-operatively, n=78) and standard TDT alone (3(rd) group: TDT alone, n=216). The 10-year patient survival rates were 72.6+/-2.6% (TDT + ATG-F single high-dose), 79.5+/-5.1% (TDT + ATG-F multiple-dose) and 67.2+/-3.7%% (TDT alone; Kaplan-Meier estimates with standard errors; ATG-F vs TDT alone, p=0.001). The 10-year graft survival rates with censoring of patients that died with a functioning graft were 73.8+/-2.4%, 57.7+/-5.8% and 58.4+/-3.6% (Kaplan-Meier estimates with standard errors; 1(st) vs 2(nd )and 3(rd) group, respectively, p<0.001) and the 10-year graft survival rates with patient death counted as graft failure were 58.3+/-2.7%, 55.7+/-5.8% and 48.2+/-3.5% (Kaplan-Meier estimates with standard errors; ATG-F single high-dose vs TDT, p=0.023). In pre-sensitized recipients there were also significant differences in favour of ATG-F, more notably in the single high-dose ATG-F induction. A total of 69% of the patients in the two cohorts receiving ATG-F did not experience any transplant rejections compared to 56% in patients undergoing TDT alone (p=0.018). The incidence of infectious complications was comparable across all groups. According to evidence obtained from the routine documentation of 778

Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration

International Nuclear Information System (INIS)

Touboul, Emmanuel; Al Halabi, Assem; Buffat, Laurent; Merienne, Louis; Huart, Judith; Schlienger, Michel; Lefkopoulos, Dimitrios; Mammar, Hamid; Missir, Odile; Meder, Jean-Francois; Laurent, Alex; Housset, Martin

1998-01-01

Purpose: Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans. Methods and Materials: From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 ± 230 mm 3 (median 968 mm 3 ; range 62-11, 250 mm 3 ). The mean minimum target dose (D min ) was 19 ± 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 ± 300 mm 3 (median 1200 mm 3 ; range 75-14 900 mm 3 ). The mean maximum dose (D max ) was 34.5 ± 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 ± 2.3 months (median 37.5; range 7-117). Results: The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 ± 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), D min by steps of 5 Gy (p = 0.005), targeted volume of the nidus (≤968 mm 3 vs. >968 mm 3 ; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the D min [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p min but does not seem to be influenced by D max and the targeted volume of the nidus

Application of the luminescence single-aliquot technique for dose estimation in the Marmara Sea

International Nuclear Information System (INIS)

Tanir, Guenes; Sencan, Emine; Boeluekdemir, M. Hicabi; Tuerkoez, M. Burak; Tel, Eyuep

2005-01-01

The aim of this study is to obtain the equivalent dose, which is the important quantity for all the studies related to the use of luminescence in dating sediments. Recent advances in luminescence dating have led to increasing application of the technique to sediment from the depositional environmental samples. The sample used in this study is the active main fault sample that was collected from the Sea of Marmara in NW Turkey. Equivalent dose was measured using both the multiple-aliquots and the single-aliquot techniques. In this study single aliquot regeneration on additive dose (SARA) procedure was also used. The result obtained was not in agreement with the results evaluated from the multiple-aliquots procedure. So a simple modification was suggested for SARA procedure. In our modified procedure the calculated dose (D) values were obtained by using the additive dose protocol instead of regeneration protocol

Effect of Low-Dose (Single-Dose Magnesium Sulfate on Postoperative Analgesia in Hysterectomy Patients Receiving Balanced General Anesthesia

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Arman Taheri

2015-01-01

Full Text Available Background and Aim. Aparallel, randomized, double blinded, placebo-controlled trial study was designed to assess the efficacy of single low dose of intravenous magnesium sulfate on post-total abdominal hysterectomy (TAH pain relief under balanced general anesthesia. Subject and Methods. Forty women undergoing TAH surgery were assigned to two magnesium sulfate (N=20 and normal saline (N=20 groups randomly. The magnesium group received magnesium sulfate 50 mg·kg−1 in 100 mL of normal saline solution i.v as single-dose, just 15 minutes before induction of anesthesia whereas patients in control group received 100 mL of 0.9% sodium chloride solution at the same time. The same balanced general anesthesia was induced for two groups. Pethidine consumption was recorded over 24 hours precisely as postoperative analgesic. Pain score was evaluated with Numeric Rating Scale (NRS at 0, 6, 12, and 24 hours after the surgeries. Results. Postoperative pain score was lower in magnesium group at 6, 12, and 24 hours after the operations significantly (P<0.05. Pethidine requirement was significantly lower in magnesium group throughout 24 hours after the surgeries (P=0.0001. Conclusion. Single dose of magnesium sulfate during balanced general anesthesia could be considered as effective and safe method to reduce postoperative pain and opioid consumption after TAH.

Evaluation of the Pharmacokinetics of Single- and Multiple-dose Buprenorphine Buccal Film in Healthy Volunteers.

Science.gov (United States)

Bai, Stephen A; Xiang, Qinfang; Finn, Andrew

2016-02-01

Buprenorphine, a partial μ-receptor agonist, is approved for the management of moderate to severe pain, but it has low oral bioavailability. Two open-label studies were performed to determine the pharmacokinetic profile of buprenorphine from buccal film formulations of buprenorphine. Both studies enrolled healthy volunteers, aged 18 to 55 years, who received concurrent oral naltrexone to reduce adverse events (AEs); subjects with a history or evidence of substance abuse or current use of any product affecting cytochrome P450 3A4 activity were excluded. The first study (n = 25) was a 5-period crossover trial with 4 single doses (75 and 300 and 300 and 1200 μg) of 2 formulations (F14 and F24) of buccal buprenorphine (BBUP) and a 300-μg intravenous dose of buprenorphine with a 7-day washout between periods. In the second study, each subject (n = 10) received 6 doses of 4 BBUP strengths (60, 120, 180, and 240 μg BID) in a dose-escalation design. Plasma concentrations of buprenorphine and norbuprenorphine were assayed, and pharmacokinetics were summarized with descriptive statistics and analyzed by using a linear mixed effects model (single-dose study). AEs were recorded. In the single-dose study, the 2 formulations exhibited comparable bioavailability of 46% to 51% that was independent of dose, with a single buprenorphine peak concentration from each BBUP dose occurring at 2.5 to 3 hours. The mean buprenorphine Cmax across the doses ranged from 0.17 ng/mL for the 75-µg dose to 1.43 ng/mL for the 1200-µg dose. AUC0-∞, AUC0-last, and Cmax were proportional to the dose of BBUP administered. Cmax of norbuprenorphine after BBUP administration was approximately one tenth that of buprenorphine Cmax. In the multiple-dose study, steady state was reached within 3 days of BID dosing. There was a linear increase in exposure across the dose range from 60 to 240 μg BID. Treatment-emergent AEs in both studies were consistent with those reported with opiate administration to

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

Toxicity studies on the radioprotective agent WR-2721 in CDF1 mice and beagle dogs

International Nuclear Information System (INIS)

Palmer, T.E.; Glaza, S.M.; Dickie, B.C.; Weltman, R.H.; Greenspun, K.S.

1985-01-01

WR-2721, S-2-(3-aminopropylamino)ethylphosphorothioic acid, is used extensively to protect normal cells during the irradiation of neoplastic cells. Dose levels for human radiotherapy are based on results obtained from laboratory animal lethality and toxicity studies. WR-2721 was administered intravenously to CDF1 mice and beagle dogs. Single dose lethality studies in mice showed the average 1/10 of the lethal dose, the median lethal dose and 9/10 the lethal dose to be 508 (1523 mg/m2), 589 (1766 mg/m2), and 682 mg/kg (2047 mg/m2), respectively. The lethal dose for female mice was lower than that for males. The 1/10 lethal dose in mice was slightly toxic to dogs; 1/10 of that dose was nontoxic. The lethal dose for dogs (6000 mg/m2) was higher than that for mice (2000 mg/m2). Clinical signs of toxicosis in the single-dose mouse toxicity study were evident in the 1st week following treatment and declined during the recovery period; signs of toxicosis were transient in dogs. Acute drug-induced pathologic changes included elevated BUN and SGOT levels, lymphoid necrosis, and renal tubular degeneration in mice. These changes were evident in the 1st week following treatment, but had dissipated by study termination. Generalized vascular changes (congestion, hemorrhage, and edema) and renal tubular degeneration occurred in treated dogs that had died or were killed moribund 7 days postinjection. These findings indicate sex-dependent and interspecies variation in the toxicity of WR-2721 with acute, but reversible, pathologic changes

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

Is a single dose of meningococcal serogroup C conjugate vaccine sufficient for protection? experience from the Netherlands

Directory of Open Access Journals (Sweden)

Kaaijk Patricia

2012-02-01

Full Text Available Abstract Background The first meningococcal serogroup C (MenC conjugate vaccine was licensed in 1999 and introduced in the United Kingdom. Countries that have implemented the MenC vaccine since then in their national immunisation programmes use different schedules. Nevertheless, all involved countries seem to experience substantial declines in the incidence of MenC disease. Discussion Since 2001, the MenC conjugate vaccine has been implemented in the Netherlands by offering a single dose to all children aged 14 months. Prior to the introduction of the vaccine into the national immunisation programme, a catch-up vaccination campaign was initiated in which a single dose of the MenC conjugate vaccine was offered to all children aged from 14 months up to and including 18 years. Since then, there has been no report of any case of MenC disease among immunocompetent vaccinees. Administration of a single dose of MenC conjugate vaccine after infancy could be beneficial considering the already complex immunisation schedules with large numbers of vaccinations in the first year of life. The present paper deals with the advantages and critical aspects of a single dose of the MenC conjugate vaccine. Summary A single dose of MenC conjugate vaccine at the age of 14 months in combination with a catch up vaccine campaign appeared to be a successful strategy to prevent MenC disease in the Netherlands, thereby confirming that a single dose of the vaccine could sufficiently protect against disease. Nevertheless, this approach can only be justified in countries with a relatively low incidence of serogroup C meningococcal disease in the first year of life. Furthermore, a good surveillance programme is recommended for timely detection of vaccine breakthroughs and outbreaks among non-vaccinees, since long-term protection after a single dose in the second year of life cannot currently be guaranteed.

Tolerization with BLP down-regulates HMGB1 a critical mediator of sepsis-related lethality.

LENUS (Irish Health Repository)

Coffey, J Calvin

2012-02-03

Tolerization with bacterial lipoprotein (BLP) affords a significant survival benefit in sepsis. Given that high mobility group box protein-1 (HMGB1) is a recognized mediator of sepsis-related lethality, we determined if tolerization with BLP leads to alterations in HMGB1. In vitro, BLP tolerization led to a reduction in HMGB1 gene transcription. This was mirrored at the protein level, as HMGB1 protein expression and release were reduced significantly in BLP-tolerized human THP-1 monocytic cells. BLP tolerance in vivo led to a highly significant, long-term survival benefit following challenge with lethal dose BLP in C57BL\\/6 mice. This was associated with an attenuation of HMGB1 release into the circulation, as evidenced by negligible serum HMGB1 levels in BLP-tolerized mice. Moreover, HMGB1 levels in peritoneal macrophages from BLP-tolerized mice were reduced significantly. Hence, tolerization with BLP leads to a down-regulation of HMGB1 protein synthesis and release. The improved survival associated with BLP tolerance could thus be explained by a reduction in HMGB1, were the latter associated with lethality in BLP-related sepsis. In testing this hypothesis, it was noted that neutralization of HMGB1, using anti-HMGB1 antibodies, abrogated BLP-associated lethality almost completely. To conclude, tolerization with BLP leads to a down-regulation of HMGB1, thus offering a novel means of targeting the latter. HMGB1 is also a mediator of lethality in BLP-related sepsis.

Influence Of Quinolone Lethality on Irradiated Anaerobic Growth of Escherichia Coli

International Nuclear Information System (INIS)

Ibrahim, I.M.; El-Kabbany, H.M.; El-Esseily, E.SH.

2012-01-01

Bacteriostatic and bactericidal activities were measured with wild type cells and isomerase mutants of Escherichia coli for ciprofloxacin, formation of quinolone-gyrase-DNA complexes, observed as a sodium dodecyl sulfate (SDS) dependent drop in cell lysate viscosity, occurred during aerobic and anaerobic growth and in the presence and in the absence of chloramphenicol. Quinolone activity against Escherichia coli was examined during aerobic growth, aerobic treatment with chloramphenicol, and anaerobic growth. Nalidixic acid, norfloxacin and ciprofloxacin were lethal for cultures growing aerobically, and the bacteriostatic activity of each quinolone was unaffected by anaerobic growth. However, lethal activity was distinct for each quinolone with cells treated aerobically with chloramphenicol or grown anaerobically. Nalidixic acid failed to kill cells under both conditions, norfloxacin killed cells when they were grown anaerobically but not when they were treated with chloramphenicol, ciprofloxacin killed cells under both conditions but required higher concentrations than those required with cells grown aerobically, C-methoxy fluoro quinolone was equally lethal under all conditions. However, lethal chromosome fragmentation, detected as a drop in viscosity in the absence of SDS, was occurred with nalidixic acid treatment only under aerobic conditions in the absence of chloramphenicol, thus, all quinolones tested appeared to form reversible bacteriostatic complexes containing broken DNA during aerobic growth, during anaerobic growth, and when protein synthesis is blocked. The ability to fragment chromosomes rapidly kill cells under these conditions depends on quinolone structure. The radiation of sublethal dose was 3 Gy at rate of 0.6 Gy/min was shown as non-significant result

Genetic interaction motif finding by expectation maximization – a novel statistical model for inferring gene modules from synthetic lethality

Directory of Open Access Journals (Sweden)

Ye Ping

2005-12-01

Full Text Available Abstract Background Synthetic lethality experiments identify pairs of genes with complementary function. More direct functional associations (for example greater probability of membership in a single protein complex may be inferred between genes that share synthetic lethal interaction partners than genes that are directly synthetic lethal. Probabilistic algorithms that identify gene modules based on motif discovery are highly appropriate for the analysis of synthetic lethal genetic interaction data and have great potential in integrative analysis of heterogeneous datasets. Results We have developed Genetic Interaction Motif Finding (GIMF, an algorithm for unsupervised motif discovery from synthetic lethal interaction data. Interaction motifs are characterized by position weight matrices and optimized through expectation maximization. Given a seed gene, GIMF performs a nonlinear transform on the input genetic interaction data and automatically assigns genes to the motif or non-motif category. We demonstrate the capacity to extract known and novel pathways for Saccharomyces cerevisiae (budding yeast. Annotations suggested for several uncharacterized genes are supported by recent experimental evidence. GIMF is efficient in computation, requires no training and automatically down-weights promiscuous genes with high degrees. Conclusion GIMF effectively identifies pathways from synthetic lethality data with several unique features. It is mostly suitable for building gene modules around seed genes. Optimal choice of one single model parameter allows construction of gene networks with different levels of confidence. The impact of hub genes the generic probabilistic framework of GIMF may be used to group other types of biological entities such as proteins based on stochastic motifs. Analysis of the strongest motifs discovered by the algorithm indicates that synthetic lethal interactions are depleted between genes within a motif, suggesting that synthetic

Bile duct evaluation of potential living liver donors with Gd-EOB-DTPA enhanced MR cholangiography: Single-dose, double dose or half-dose contrast enhanced imaging

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Kinner, Sonja, E-mail: Sonja.Kinner@uni-due.de [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Steinweg, Verena [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Maderwald, Stefan [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany); Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Radtke, Arnold; Sotiropoulos, Georgios [Department of General Surgery, University Hospital Essen (Germany); Forsting, Michael; Schroeder, Tobias [Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen (Germany)

2014-05-15

Introduction: Detailed knowledge of the biliary anatomy is essential to avoid complications in living donor liver transplantation. The aim of this study was to determine the optimal dosage of Gd-EOB-DTPA for contrast-enhanced magnetic resonance cholangiography (ce-MRC) with reference to contrast-enhanced CT cholangiography (ce-CTC). Materials and methods: 30 potential living liver donors (PLLD) underwent both ce-CTC and ce-MRC. Ten candidates each received single, double or half-dose Gd-EOB-DTPA. Ce-MRC images with and without inversion recovery pulses (T1w ± IR) were acquired 20–30 min after intravenous contrast injection. Image data was quantitatively and qualitatively reviewed by two radiologists based on a on a 5-point scale. Data sets were compared using a Mann–Whitney-U-test or Wilcoxon-rank-sum-test. Kappa values were also calculated. Results: All image series provided sufficient diagnostic information both showing normal biliary anatomy and variant bile ducts. Ce-CTC showed statistically significant better results compared to all ce-MRC data sets. T1w MRC with single dose Gd-EOB-DTPA proved to be superior to half and double dose in subjective and objective evaluation without a statistically significant difference. Conclusions: Ce-MRC is at any dosage inferior to ce-CTC. As far as preoperative planning of bile duct surgery is focused on the central biliary anatomy, ce-MRC can replace harmful ce-CTC strategies, anyway. Best results were seen with single dose GD-EOB-DTPA on T1w MRC+IR.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Lethal and mutagenic effects of ion beams and γ-rays in Aspergillus oryzae

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Toyoshima, Yoshiyuki, E-mail: toyoshima@yamasa.com [Soy Sauce Laboratory, Yamasa Corporation, 2-10-1 Araoicho, Choshi, Chiba 288-0056 (Japan); Takahashi, Akemi; Tanaka, Hisaki; Watanabe, Jun; Mogi, Yoshinobu; Yamazaki, Tatsuo [Soy Sauce Laboratory, Yamasa Corporation, 2-10-1 Araoicho, Choshi, Chiba 288-0056 (Japan); Hamada, Ryoko; Iwashita, Kazuhiro [Fundamental Research Division, National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashihiroshima, Hiroshima 739-0046 (Japan); Satoh, Katsuya; Narumi, Issay [Ion Beam Mutagenesis Research Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

2012-12-15

Highlights: ► We investigated the effects of different LET radiation in A. oryzae. ► Both γ-rays and ion beams induced base substitutions, frameshifts, deletions. ► Both γ-rays and ion beams induced genome-wide large-scale mutations in A. oryzae. ► Some differences in the types and frequencies of mutations were found. ► Our results provide new basic insights into the mutation breeding of A. oryzae. - Abstract: 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 {sup 12}C{sup 5+} ion beams with an LET of 121 keV/μm. The {sup 12}C{sup 5+} ion beams had a 3.6-times higher lethal effect than low-LET (0.2 keV/μm) γ-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. {sup 12}C{sup 6+} ion beams with an LET of 86 keV/μm were the most effective in inducing selenate resistance. The mutant frequency following exposure to {sup 12}C{sup 6+} ion beams increased with an increase in dose and reached 3.47 × 10{sup −3} at 700 Gy. In the dose range from 0 to 700 Gy, {sup 12}C{sup 5+} ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67 × 10{sup −3}) at 400 Gy. 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 {sup 12}C{sup 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

Lethal photosensitization of biofilm-grown bacteria

Science.gov (United States)

Wilson, Michael

1997-12-01

Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

Science.gov (United States)

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Single and Multiple Ascending-dose Studies of Oral Delafloxacin: Effects of Food, Sex, and Age.

Science.gov (United States)

Hoover, Randall; Hunt, Thomas; Benedict, Michael; Paulson, Susan K; Lawrence, Laura; Cammarata, Sue; Sun, Eugene

2016-01-01

The objective of this report is describe the results of 2 studies that examined the pharmacokinetic parameters, safety profile, and tolerability of single and multiple ascending doses of oral delafloxacin and the effects of food, sex, and age on oral delafloxacin pharmacokinetic parameters, safety profile, and tolerability. The first study contained 3 parts and used unformulated delafloxacin in a capsule. Part 1 was a randomized, double-blind, placebo-controlled, single (50, 100, 200, 400, 800, 1200, and 1600 mg) ascending-dose study of oral delafloxacin in healthy men. Part 2 was a single-dose crossover study in which 20 men received 250 mg delafloxacin with or without food. Part 2 also included a parallel group, double-blind, placebo-controlled study in 16 women and 16 elderly men and women who were randomized (3:1) to receive 250 mg delafloxacin or placebo. Part 3 was a randomized, double-blind, placebo-controlled, multiple (100, 200, 400, 800, 1200 mg once daily for 5 days) ascending-dose study of oral delafloxacin in healthy men. The second study was a single-dose, randomized, 3-period crossover study in which participants received 900 mg delafloxacin (2 × 450-mg tablets) under fasted conditions, with a high-fat meal, or fasted with a high-fat meal 2 hours after dosing. Serial blood samples were collected, and plasma pharmacokinetic parameters of delafloxacin were determined. Delafloxacin Cmax and AUC0-∞ increased with increasing oral dose over the dose range of 50 to 1600 mg. The increases in delafloxacin AUC0-∞ were dose proportional at doses of ≥200 mg. Steady state was reached by day 3 of dosing with minimal accumulation of delafloxacin. The Cmax of delafloxacin was decreased slightly in the presence of food. No sex difference in delafloxacin pharmacokinetic parameters was observed. In the elderly men and women, mean delafloxacin Cmax and AUC0-∞ were 35% higher than observed for young adults, which could be partially explained by a decrease in

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

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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

Study on children patient dose in single-detector and multi-detector row helical computed tomography

International Nuclear Information System (INIS)

Lu Heqing; Zhu Guoying; Zhuo Weihai; Liu Haikuan; Guo Changyi

2008-01-01

Objective: To study and evaluate the radiation dose of children patient in single-detector and multi-detector row helical CT scan. Methods: The head and body CT dose index of 21 CT scanners were tested. Then the values of CTDI w , CTDI vol and DLP were calculated combining with the parameters of routine head and chest scan for children of 0-1 year old group, 5 years old group, 10 years old group and adults. The effective doses of children of every age group and adults in routine head and chest scan were subsequently estimated from effective dose per DLP by age and the calculated values of DLP. Results: CTDI per mAs is greater in the head than that in the body. In head routine scan, the effective doses of 0-1 year old group,5 years old group and 10 year old group were 2.2, 1.3 and 1.1 mSv, respectively. In chest routine scan, the effective doses of 0-1 year old group,5 years old group and 10 years old group were 5.3, 3.1 and 3.4 mSv, respectively. Effective doses to children per mAs are equally 1.8 times higher than corresponding values for adults. The CTDI vol , DLP and effective dose to children in head routine scan for MDCT were greater those that for single-detector CT and dual- detector CT. The CTDI vol , DLP and effective dose to children in chest routine scan for MDCT and dual-detector row CT were smaller than that for single-detector row CT. Conclusions: Children me more radiation risk in CT examination as compared with adults. So we should strictly abide by justification of children CT examination, and optimize the parameters of CT scan rationally in order to reduce the radiation dose to children patient as much as possible. (authors)

LET dependence of linear and quadratic terms in dose-response relationships for cellular damage: correlations with the dimensions and structures of biological targets

International Nuclear Information System (INIS)

Barendsen, G.W.; Amsterdam Univ.

1990-01-01

To apply information from microdosimetric studies and from cellular responses to the development and testing of hypotheses about mechanisms of radiation action, it is necessary to correlate these data with insights concerning dimensions and structures of cellular constituents and macromolecules. This approach is illustrated by the correlation of cross sections for inactivation with dimensions of the cell nucleus in dependence on the culture conditions and by the comparison of the derived dimensions of critical targets with DNA packing and chromatin structure in cells. A model is suggested in which lethal and potentially lethal damage induced in mammalian cells by single ionising particles involves the induction of two DNA double strand breaks in close proximity in a chromatin fibre, while accumulation of damage causing the contribution, which increases with the square of the dose, might be associated with interaction of single DSBs produced at larger distances. (author)

Acoustic neuromas: single dose vs fractionated therapy

Energy Technology Data Exchange (ETDEWEB)

Fuss, M; Debus, J; Lohr, F; Engenhart-Cabillic, R; Wannenmacher, M

1997-07-01

Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

Seed irradiation with continuously increasing doses of thermal neutrons

International Nuclear Information System (INIS)

Uhlik, J.; Pfeifer, M.; Pittermann, P.

1977-01-01

In the 'Raman' pea cv. the biological activity of thermal neutrons was investigated after irradiation of a 780 mm column of seeds for 3000 and 4167 seconds with a flux of 5.607 x 10 9 n.cm -2 per second. For different fractions of the seed column the average density of the neutron flux was calculated. It was proved that for the described method of seed irradiation it was sufficient to determine only the dose approaching the lethal dose. If a sufficiently high column of seeds is used part of the column of seeds will be irradiated with the optimum range of doses. The advantages of the suggested method of irradiation are not only smaller time and technological requirements resulting from the need for the determination of only the critical lethal dose of radiation by means of inhibition tests performed with seedlings, but also a simpler irradiation procedure. The suggested method of irradiation is at least nine times cheaper. (author)

Single dose oral ketoprofen and dexketoprofen for acute postoperative pain in adults.

Science.gov (United States)

Barden, Jodie; Derry, Sheena; McQuay, Henry J; Moore, R Andrew

2009-10-07

Ketoprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID) used to treat acute and chronic painful conditions. Dexketoprofen is the (S)-enantiomer, which is believed to confer analgesia. Theoretically dexketoprofen is expected to provide equivalent analgesia to ketoprofen at half the dose, with a consequent reduction in gastrointestinal adverse events. To assess efficacy, duration of action, and associated adverse events of single dose oral ketoprofen and dexketoprofen in acute postoperative pain in adults. We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to August 2009. Randomised, double blind, placebo-controlled trials of single dose orally administered ketoprofen and dexketoprofen in adults with moderate to severe acute postoperative pain. Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals was collected. Fourteen studies compared ketoprofen (968 participants) at mainly 25 mg and 50 mg with placebo (520 participants). Seven studies compared dexketoprofen (681 participants) at mainly 10 mg to 25 mg with placebo (289 participants). Studies were of adequate reporting quality, and participants had pain following dental, orthopaedic, obstetric, gynaecological and general surgery. There was considerable clinical heterogeneity between studies in dental and other types of surgery, particularly bunionectomy, which limited analysis.Ketoprofen at doses between 12.5 mg and 100 mg produced NNTs for at least 50% pain relief over 4 to 6

Effect of propranolol in head tremor: quantitative study following single-dose and sustained drug administration.

Science.gov (United States)

Calzetti, S; Sasso, E; Negrotti, A; Baratti, M; Fava, R

1992-12-01

The effect of the beta-adrenoceptor antagonist propranolol has been investigated in nine patients suffering from isolated (six patients) or prominent (three patients) essential tremor of the head. In a double-blind, placebo-controlled study the tremorolytic efficacy of propranolol has been assessed by a quantitative accelerometric method after a single oral dose (120 mg) and following 2 weeks of sustained treatment with two different dosage regimens of the drug (120 and 240 mg daily). As compared with placebo, a significant reduction in tremor magnitude was found following a single oral dose but not on sustained administration of the beta-blocker at either dosage. The results suggest that the efficacy of sustained propranolol on isolated or prominent essential head tremor is less predictable and satisfactory than expected on the basis of the single-dose response, as compared with hand tremor.

A linear-quadratic model of cell survival considering both sublethal and potentially lethal radiation damage

International Nuclear Information System (INIS)

Rutz, H.P.; Coucke, P.A.; Mirimanoff, R.O.

1991-01-01

The authors assessed the dose-dependence of repair of potentially lethal damage in Chinese hamster ovary cells x-irradiated in vitro. The recovery ratio (RR) by which survival (SF) of the irradiated cells was enhanced increased exponentially with a linear and a quadratic component namely ζ and ψ: RR=exp(ζD+ψD 2 ). Survival of irradiated cells can thus be expressed by a combined linear-quadratic model considering 4 variables, namely α and β for the capacity of the cells to accumulate sublethal damage, and ζ and ψ for their capacity to repair potentially lethal damage: SF=exp((ζ-α)D+ (ψ-β)D 2 ). author. 26 refs.; 1 fig.; 1 tab

Pharmacokinetics of lansoprazole and its main metabolites after single and multiple intravenous doses in healthy Chinese subjects.

Science.gov (United States)

Zhang, Dan; Zhang, Yanan; Liu, Man; Wang, Xiaolin; Yang, Man; Han, Jing; Liu, Huichen

2013-09-01

The aim of the study was to evaluate and compare the pharmacokinetics of lansoprazole (LPZ) and its main metabolites, 5'-hydroxy lansoprazole (HLPZ) and lansoprazole sulfone (LPZS), after single and multiple intravenous (i.v.) doses of LPZ in healthy Chinese subjects. Twelve subjects (six males and six females) were given a single dose of LPZ by i.v. infusion on day 1, and multiple doses from day 2 to day 6. Blood samples were collected at designated time points for analysis of plasma concentrations of LPZ, HLPZ and LPZS by an LC-MS/MS method. LPZ was generally well tolerated in healthy Chinese subjects. After single and multiple i.v. doses of 30 mg LPZ, the C max values of LPZ, HLPZ and LPZS were 1490 ± 290 and 1450 ± 280, 175 ± 71 and 154 ± 56, and 51.3 ± 82.9 and 74.1 ± 158.7 ng/mL, with the AUC0-t values 3280 ± 2550 and 4260 ± 3880, 381 ± 128 and 389 ± 111, and 389 ± 1204 and 700 ± 2255 ng h/mL, respectively. The t 1/2 and CL values of LPZ after single and multiple i.v. doses were 1.48 ± 1.03 and 2.19 ± 1.03 h, and 11.67 ± 4.49 and 9.56 ± 4.08 L/h, respectively. Compared with the pharmacokinetics of LPZ after a single dose, t 1/2 increased markedly, CL decreased significantly and AUC increased by over 20 % after multiple doses. The results indicated that there was drug accumulation of LPZ after multiple i.v. doses, and there was no gender-related difference in pharmacokinetics of LPZ and its two metabolites.

A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles.

Science.gov (United States)

Kurosawa, Yuko; Nirengi, Shinsuke; Homma, Toshiyuki; Esaki, Kazuki; Ohta, Mitsuhiro; Clark, Joseph F; Hamaoka, Takafumi

2015-06-25

Our aim was to determine the quantitative effects of a single-dose of Nattokinase (NK) administration on coagulation/fibrinolysis parameters comprehensively in healthy male subjects. A double-blind, placebo-controlled cross-over NK intervention study was carried out in 12 healthy young males. Following the baseline blood draw, each subject was randomized to receive either a single-dose of 2,000 FU NK (NSK-SD, Japan Bio Science Laboratory Co., Ltd) or placebo with subsequent cross-over of the groups. Subjects donated blood samples at 2, 4, 6 and 8 hours following administration for analysis of coagulation/fibrinolysis parameters. As a result, D-dimer concentrations at 6, and 8 hours, and blood fibrin/fibrinogen degradation products at 4 hours after NK administration elevated significantly (p < 0.05, respectively). Factor VIII activity declined at 4 and 6 hours (p < 0.05, respectively), blood antithrombin concentration was higher at 2 and 4 hours (p < 0.05, respectively), and the activated partial thromboplastin time prolonged significantly at 2 and 4 hours following NK administration (p < 0.05 and p < 0.01, respectively). All the changes, however, were within the normal range. In conclusion, thus, a single-dose of NK administration appears enhancing fibrinolysis and anti-coagulation via several different pathways simultaneously.

Presence of virus neutralizing antibodies in cerebral spinal fluid correlates with non-lethal rabies in dogs.

Directory of Open Access Journals (Sweden)

Clement W Gnanadurai

Full Text Available Rabies is traditionally considered a uniformly fatal disease after onset of clinical manifestations. However, increasing evidence indicates that non-lethal infection as well as recovery from flaccid paralysis and encephalitis occurs in laboratory animals as well as humans.Non-lethal rabies infection in dogs experimentally infected with wild type dog rabies virus (RABV, wt DRV-Mexico correlates with the presence of high level of virus neutralizing antibodies (VNA in the cerebral spinal fluid (CSF and mild immune cell accumulation in the central nervous system (CNS. By contrast, dogs that succumbed to rabies showed only little or no VNA in the serum or in the CSF and severe inflammation in the CNS. Dogs vaccinated with a rabies vaccine showed no clinical signs of rabies and survived challenge with a lethal dose of wild-type DRV. VNA was detected in the serum, but not in the CSF of immunized dogs. Thus the presence of VNA is critical for inhibiting virus spread within the CNS and eventually clearing the virus from the CNS.Non-lethal infection with wt RABV correlates with the presence of VNA in the CNS. Therefore production of VNA within the CNS or invasion of VNA from the periphery into the CNS via compromised blood-brain barrier is important for clearing the virus infection from CNS, thereby preventing an otherwise lethal rabies virus infection.

Effect of different radiation doses on pupae of cabbage butterfly, (pieris brassicae)

International Nuclear Information System (INIS)

Sattar, A.; Khattak, S.U.

1989-01-01

The lots of 12 pupae, 3-2 days old, were irradiated at different radiation doses for each treatment. There was no emergence at 40 Krad showing that this dose was the lethal dose for the pupae of this insects. There was a significant reduction in adult emergence below this dose. (A.B.)

Factors influencing circadian rhythms in acetaminophen lethality.

Science.gov (United States)

Schnell, R C; Bozigian, H P; Davies, M H; Merrick, B A; Park, K S; McMillan, D A

1984-01-01

Experiments were conducted to examine the effects of changes in lighting schedules and food consumption on circadian rhythms in acetaminophen lethality and hepatic glutathione levels in male mice. Under a normal lighting schedule (light: 06.00-18.00 h), male mice exhibited a circadian rhythm in acetaminophen lethality (peak: 18.00 h; nadir: 06.00, 10.00 h) and an inverse rhythm in hepatic glutathione concentrations (peak: 06.00, 10.00 h; nadir: 18.00 h). Under a reversed lighting schedule (light: 18.00-06.00 h) the glutathione rhythm was reversed and the rhythm in acetaminophen lethality was altered showing greater sensitivity to the drug. Under continuous light, there was a shift in the acetaminophen lethality and the hepatic glutathione rhythms. Under continuous dark, both rhythms were abolished. Under a normal lighting regimen, hepatic glutathione levels were closely correlated with food consumption; i.e., both were increased during the dark phase and decreased during the light phase. Fasting the mice for 12 h abolished the rhythms in acetaminophen lethality and hepatic glutathione levels; moreover, the lethality was increased and the hepatic glutathione levels were decreased. These experiments show that both lighting schedules and feeding can alter the circadian rhythms in acetaminophen lethality and hepatic glutathione levels in male mice.

CD4 T cell-mediated protection from lethal influenza: perforin and antibody-mediated mechanisms give a one-two punch.

Science.gov (United States)

Brown, Deborah M; Dilzer, Allison M; Meents, Dana L; Swain, Susan L

2006-09-01

The mechanisms whereby CD4 T cells contribute to the protective response against lethal influenza infection remain poorly characterized. To define the role of CD4 cells in protection against a highly pathogenic strain of influenza, virus-specific TCR transgenic CD4 effectors were generated in vitro and transferred into mice given lethal influenza infection. Primed CD4 effectors conferred protection against lethal infection over a broad range of viral dose. The protection mediated by CD4 effectors did not require IFN-gamma or host T cells, but did result in increased anti-influenza Ab titers compared with untreated controls. Further studies indicated that CD4-mediated protection at high doses of influenza required B cells, and that passive transfer of anti-influenza immune serum was therapeutic in B cell-deficient mice, but only when CD4 effectors were present. Primed CD4 cells also acquired perforin (Pfn)-mediated cytolytic activity during effector generation, suggesting a second mechanism used by CD4 cells to confer protection. Pfn-deficient CD4 effectors were less able to promote survival in intact BALB/c mice and were unable to provide protection in B cell-deficient mice, indicating that Ab-independent protection by CD4 effectors requires Pfn. Therefore, CD4 effectors mediate protection to lethal influenza through at least two mechanisms: Pfn-mediated cytotoxicity early in the response promoted survival independently of Ab production, whereas CD4-driven B cell responses resulted in high titer Abs that neutralized remaining virus.

Comparative pharmacokinetics of oxytetracycline in blunt-snout bream (Megalobrama amblycephala) with single and multiple-dose oral administration.

Science.gov (United States)

Li, Ru-Qin; Ren, Yu-Wei; Li, Jing; Huang, Can; Shao, Jun-Hui; Chen, Xiao-Xuan; Wu, Zhi-Xin

2015-06-01

Research into the pharmacokinetics and residue elimination of oxytetracycline (OTC) is important both to determine the optimal dosage regimens and to establish a safe withdrawal time in fish. A depletion study is presented here for OTC in Megalobrama amblycephala with a single-dose (100 mg/kg) and multiple-dose (100 mg/kg for five consecutive days) oral administration. The study was conducted at 25 °C. As a result, a one-compartment model was developed. For the single dose, the absorption half-life was 5.79, 9.40, 6.96, and 8.06 h in the plasma, liver, kidney, and muscle, respectively. However, the absorption half-life was 3.62, 7.33, 4.59, and 6.02 h with multiple-dose oral administration. The elimination half-time in the plasma, liver, kidney, and muscle was 58.63, 126.43, 65.1, and 58.85 h when M. amblycephala was treated with a single dose. However, the elimination half-time changed to 91.75, 214.87, 126.22, and 135.84 h with multiple-dose oral administration.

Experience of micromultileaf collimator linear accelerator based single fraction stereotactic radiosurgery: Tumor dose inhomogeneity, conformity, and dose fall off

Energy Technology Data Exchange (ETDEWEB)

Hong, Linda X.; Garg, Madhur; Lasala, Patrick; Kim, Mimi; Mah, Dennis; Chen, Chin-Cheng; Yaparpalvi, Ravindra; Mynampati, Dinesh; Kuo, Hsiang-Chi; Guha, Chandan; Kalnicki, Shalom [Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Neurosurgery, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Epidemiology and Population Health, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States); Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

2011-03-15

Purpose: Sharp dose fall off outside a tumor is essential for high dose single fraction stereotactic radiosurgery (SRS) plans. This study explores the relationship among tumor dose inhomogeneity, conformity, and dose fall off in normal tissues for micromultileaf collimator (mMLC) linear accelerator (LINAC) based cranial SRS plans. Methods: Between January 2007 and July 2009, 65 patients with single cranial lesions were treated with LINAC-based SRS. Among them, tumors had maximum diameters {<=}20 mm: 31; between 20 and 30 mm: 21; and >30 mm: 13. All patients were treated with 6 MV photons on a Trilogy linear accelerator (Varian Medical Systems, Palo Alto, CA) with a tertiary m3 high-resolution mMLC (Brainlab, Feldkirchen, Germany), using either noncoplanar conformal fixed fields or dynamic conformal arcs. The authors also created retrospective study plans with identical beam arrangement as the treated plan but with different tumor dose inhomogeneity by varying the beam margins around the planning target volume (PTV). All retrospective study plans were normalized so that the minimum PTV dose was the prescription dose (PD). Isocenter dose, mean PTV dose, RTOG conformity index (CI), RTOG homogeneity index (HI), dose gradient index R{sub 50}-R{sub 100} (defined as the difference between equivalent sphere radius of 50% isodose volume and prescription isodose volume), and normal tissue volume (as a ratio to PTV volume) receiving 50% prescription dose (NTV{sub 50}) were calculated. Results: HI was inversely related to the beam margins around the PTV. CI had a ''V'' shaped relationship with HI, reaching a minimum when HI was approximately 1.3. Isocenter dose and mean PTV dose (as percentage of PD) increased linearly with HI. R{sub 50}-R{sub 100} and NTV{sub 50} initially declined with HI and then reached a plateau when HI was approximately 1.3. These trends also held when tumors were grouped according to their maximum diameters. The smallest tumor group

Incorporating single-side sparing in models for predicting parotid dose sparing in head and neck IMRT

International Nuclear Information System (INIS)

Yuan, Lulin; Wu, Q. Jackie; Yin, Fang-Fang; Yoo, David; Jiang, Yuliang; Ge, Yaorong

2014-01-01

Purpose: Sparing of single-side parotid gland is a common practice in head-and-neck (HN) intensity modulated radiation therapy (IMRT) planning. It is a special case of dose sparing tradeoff between different organs-at-risk. The authors describe an improved mathematical model for predicting achievable dose sparing in parotid glands in HN IMRT planning that incorporates single-side sparing considerations based on patient anatomy and learning from prior plan data. Methods: Among 68 HN cases analyzed retrospectively, 35 cases had physician prescribed single-side parotid sparing preferences. The single-side sparing model was trained with cases which had single-side sparing preferences, while the standard model was trained with the remainder of cases. A receiver operating characteristics (ROC) analysis was performed to determine the best criterion that separates the two case groups using the physician's single-side sparing prescription as ground truth. The final predictive model (combined model) takes into account the single-side sparing by switching between the standard and single-side sparing models according to the single-side sparing criterion. The models were tested with 20 additional cases. The significance of the improvement of prediction accuracy by the combined model over the standard model was evaluated using the Wilcoxon rank-sum test. Results: Using the ROC analysis, the best single-side sparing criterion is (1) the predicted median dose of one parotid is higher than 24 Gy; and (2) that of the other is higher than 7 Gy. This criterion gives a true positive rate of 0.82 and a false positive rate of 0.19, respectively. For the bilateral sparing cases, the combined and the standard models performed equally well, with the median of the prediction errors for parotid median dose being 0.34 Gy by both models (p = 0.81). For the single-side sparing cases, the standard model overestimates the median dose by 7.8 Gy on average, while the predictions by the combined

Pharmacokinetics and Safety of Intravenous Murepavadin Infusion in Healthy Adult Subjects Administered Single and Multiple Ascending Doses.

Science.gov (United States)

Wach, Achim; Dembowsky, Klaus; Dale, Glenn E

2018-04-01

Murepavadin is the first in class of the outer membrane protein-targeting antibiotics (OMPTA) and a pathogen-specific peptidomimetic antibacterial with a novel, nonlytic mechanism of action targeting Pseudomonas aeruginosa Murepavadin is being developed for the treatment of hospital-acquired bacterial pneumonia (HABP) and ventilator-associated bacterial pneumonia (VABP). The pharmacokinetics (PK) and safety of single and multiple doses of murepavadin were investigated in healthy male subjects. Part A of the study was a double-blind, randomized, placebo-controlled, single-ascending-dose investigation in 10 sequential cohorts where each cohort comprised 6 healthy male subjects; 4 subjects were randomized to murepavadin, and 2 subjects were randomized to placebo. Part B was a double-blind, randomized, placebo-controlled, multiple-ascending-dose investigation in 3 sequential cohorts. After a single dose of murepavadin, the geometric mean half-life (2.52 to 5.30 h), the total clearance (80.1 to 114 ml/h/kg), and the volume of distribution (415 to 724 ml/kg) were consistent across dose levels. The pharmacokinetics of the dosing regimens evaluated were dose proportional and linear. Murepavadin was well tolerated, adverse events were transient and generally mild, and no dose-limiting toxicity was identified. Copyright © 2018 American Society for Microbiology.

Determination of burial dose in incompletely bleached fluvial samples using single grains of quartz

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, Lars

2007-01-01

We determine the burial dose in three known-age incompletely bleached fluvial samples using single grains of quartz. Estimation of burial dose in incompletely bleached samples requires that the characteristics of the well-bleached part of the distribution are known in order to distinguish between...... well-bleached and poorly bleached grains. It is especially important to investigate if the uncertainties assigned to individual estimates of dose adequately describe the observed variability in well-bleached dose distributions. We investigate this by quantifying the overdispersion in laboratory-bleached...

Pharmacokinetics of voriconazole after oral administration of single and multiple doses in Hispaniolan Amazon parrots (Amazona ventralis).

Science.gov (United States)

Sanchez-Migallon Guzman, David; Flammer, Keven; Papich, Mark G; Grooters, Amy M; Shaw, Shannon; Applegate, Jeff; Tully, Thomas N

2010-04-01

To determine the pharmacokinetics and safety of voriconazole administered orally in single and multiple doses in Hispaniolan Amazon parrots (Amazona ventralis). 15 clinically normal adult Hispaniolan Amazon parrots. Single doses of voriconazole (12 or 24 mg/kg) were administered orally to 15 and 12 birds, respectively; plasma voriconazole concentrations were determined at intervals via high-pressure liquid chromatography. In a multiple-dose trial, voriconazole (18 mg/kg) or water was administered orally to 6 and 4 birds, respectively, every 8 hours for 11 days (beginning day 0); trough plasma voriconazole concentrations were evaluated on 3 days. Birds were monitored daily, and clinicopathologic variables were evaluated before and after the trial. Voriconazole elimination half-life was short (0.70 to 1.25 hours). In the single-dose experiments, higher drug doses yielded proportional increases in the maximum plasma voriconazole concentration (C(max)) and area under the curve (AUC). In the multiple-dose trial, C(max), AUC, and plasma concentrations at 2 and 4 hours were decreased on day 10, compared with day 0 values; however, there was relatively little change in terminal half-life. With the exception of 1 voriconazole-treated parrot that developed polyuria, adverse effects were not evident. In Hispaniolan Amazon parrots, oral administration of voriconazole was associated with proportional kinetics following administration of single doses and a decrease in plasma concentration following administration of multiple doses. Oral administration of 18 mg of voriconazole/kg every 8 hours would require adjustment to maintain therapeutic concentrations during long-term treatment. Safety and efficacy of voriconazole treatment in this species require further investigation.

Dose-response tests and semi-field evaluation of lethal and sub-lethal effects of slow release pyriproxyfen granules (Sumilarv®0.5G) for the control of the malaria vectors Anopheles gambiae sensu lato.

Science.gov (United States)

Mbare, Oscar; Lindsay, Steven W; Fillinger, Ulrike

2013-03-14

Recently research has shown that larviciding can be an effective tool for integrated malaria vector control. Nevertheless, the uptake of this intervention has been hampered by the need to re-apply larvicides frequently. There is a need to explore persistent, environmentally friendly larvicides for malaria vector control to reduce intervention efforts and costs by reducing the frequency of application. In this study, the efficacy of a 0.5% pyriproxyfen granule (Surmilarv®0.5G, Sumitomo Chemicals) was assessed for the control of Anopheles gambiae sensu stricto and Anopheles arabiensis, the major malaria vectors in sub-Saharan Africa. Dose-response and standardized field tests were implemented following standard procedures of the World Health Organization's Pesticide Evaluation Scheme to determine: (i) the susceptibility of vectors to this formulation; (ii) the residual activity and appropriate retreatment schedule for field application; and, (iii) sub-lethal impacts on the number and viability of eggs laid by adults after exposure to Sumilarv®0.5G during larval development. Anopheles gambiae s.s. and An. arabiensis were highly susceptible to Sumilarv®0.5G. Estimated emergence inhibition (EI) values were very low and similar for both species. The minimum dosage that completely inhibited adult emergence was between 0.01-0.03 parts per million (ppm) active ingredient (ai). Compared to the untreated control, an application of 0.018 ppm ai prevented 85% (95% confidence interval (CI) 82%-88%) of adult emergence over six weeks under standardized field conditions. A fivefold increase in dosage of 0.09 ppm ai prevented 97% (95% CI 94%-98%) emergence. Significant sub-lethal effects were observed in the standardized field tests. Female An. gambiae s.s. that were exposed to 0.018 ppm ai as larvae laid 47% less eggs, and females exposed to 0.09 ppm ai laid 74% less eggs than females that were unexposed to the treatment. Furthermore, 77% of eggs laid by females exposed to 0

Experimental evaluation of the relationship between lethal or non-lethal virulence and transmission success in malaria parasite infections

Directory of Open Access Journals (Sweden)

Nithiuthai S

2004-09-01

Full Text Available Abstract Background Evolutionary theory suggests that the selection pressure on parasites to maximize their transmission determines their optimal host exploitation strategies and thus their virulence. Establishing the adaptive basis to parasite life history traits has important consequences for predicting parasite responses to public health interventions. In this study we examine the extent to which malaria parasites conform to the predicted adaptive trade-off between transmission and virulence, as defined by mortality. The majority of natural infections, however, result in sub-lethal virulent effects (e.g. anaemia and are often composed of many strains. Both sub-lethal effects and pathogen population structure have been theoretically shown to have important consequences for virulence evolution. Thus, we additionally examine the relationship between anaemia and transmission in single and mixed clone infections. Results Whereas there was a trade-off between transmission success and virulence as defined by host mortality, contradictory clone-specific patterns occurred when defining virulence by anaemia. A negative relationship between anaemia and transmission success was found for one of the parasite clones, whereas there was no relationship for the other. Notably the two parasite clones also differed in a transmission phenotype (gametocyte sex ratio that has previously been shown to respond adaptively to a changing blood environment. In addition, as predicted by evolutionary theory, mixed infections resulted in increased anaemia. The increased anaemia was, however, not correlated with any discernable parasite trait (e.g. parasite density or with increased transmission. Conclusions We found some evidence supporting the hypothesis that there is an adaptive basis correlating virulence (as defined by host mortality and transmission success in malaria parasites. This confirms the validity of applying evolutionary virulence theory to biomedical

Single dose planning for radioiodine-131 therapy of Graves' disease

International Nuclear Information System (INIS)

Kita, Tamotsu; Yokoyama, Kunihiko; Kinuya, Seigo; Taki, Junichi; Michigishi, Takatoshi; Tonami, Norihisa

2004-01-01

Patients with Graves' disease were studied one year after radioiodine-131 therapy to assess the relationship between the effectiveness of the therapy and the radioiodine doses used. Patients were classified into three groups according to thyroid function as hyperthyroidism, euthyroidism and hypothyroidism at one year after I-131 therapy. In these groups we compared the mean values of dose, dose per thyroid weight calculated with I-123 uptake before the therapy (pre D/W), dose per thyroid weight calculated with therapeutic I-131 uptake (post D/W), and absorbed dose. No significant differences were found between the three groups in terms of dose or pre D/W. The mean values of post D/W and absorbed dose in the non-hyperthyroid (euthyroid and hypothyroid) group were significantly greater than those in the hyperthyroid group. Post D/W of 6.3 MBq/g was a threshold separating the non-hyperthyroid group from the hyperthyroid group. There was no correlation between pre D/W and post D/W; however, the mean post D/W was significantly greater than the mean pre D/W. All patients with pre D/W above 6.3 MBq/g showed non-hyperthyroidism at one year after the radioiodine treatment. No indicators before the radioiodine therapy had significant relationships with the effectiveness of the therapy at one year after the treatment. However, the single therapy planned for setting the pre D/W above 6.3 MBq/g will certainly make the patients non-hyperthyroid. As this proposal of dose planning is based on a small number of patients, further study is needed. (author)

Correlation between γ-ray-induced DNA double-strand breakage and cell killing after biologically relevant doses: analysis by pulsed-field gel electrophoresis

International Nuclear Information System (INIS)

Murray, D.

1994-01-01

We examined the degree of correlation between γ-ray-induced lethality and DNA double-strand breaks (dsbs) after biologically relevant doses of radiation. Radiation lethality was modified by treating 14 C-labelled Chinese hamster ovary cells with either of two aminothiols (WR-1065 or WR-255591) and the associated effect on dsb induction was determined by pulsed-field gel electrophoresis (PFGE). The use of phosphorimaging to analyse the distribution of 14 C-activity in the gel greatly improved the low-dose resolution of the PFGE assay. Both WR-1065 and WR-255591 protected against dsb induction and lethality to a similar extent after low doses of radiation. although this correlation broke down when supralethal doses were used to induce dsbs. Thus, the level of dsbs induced in these cells as measured by PFGE after survival-curve doses of γ-radiation is consistently predictive of the degree of lethality obtained, implying a cause-effect relationship between these two parameters and confirming previous results obtained using the neutral filter elution assay for dsbs. (author)

Diabetes susceptibility of BALB/cBOM mice treated with streptozotocin. Inhibition by lethal irradiation and restoration by splenic lymphocytes

International Nuclear Information System (INIS)

Paik, S.G.; Blue, M.L.; Fleischer, N.; Shin, S.

1982-01-01

In genetically susceptible strains of mice, repeated injections of a subdiabetogenic dose of streptozotocin induces the development of progressive insulin-dependent hyperglycemia. We showed previously that host T-cell functions play an obligatory etiologic role in this experimental disease by demonstrating that the athymic nude mouse is resistant to diabetes induction unless its T-cell functions are reconstituted by thymus graft. Here we show that lethal irradiation of euthymic (+/nu) mice of BALB/cBOM background causes selective resistance of the mice to the diabetogenic effects of the multiple low doses of streptozotocin without affecting their sensitivity to a high pharmacologic dose of the toxin. We also show that reconstitution of the irradiated mice with splenic lymphocytes causes the restoration of diabetes susceptibility. Lethally irradiated mice thus represent a useful experimental model for analyzing the host functions involved in the development of this disease. These results provide an additional support for the hypothesis that the induction of diabetes in this model system is mediated by an autoimmune amplification mechanism

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.)

The lethal effect of longwave ultraviolet light and PUVA. An analysis based upon human mesenchymal cells in vitro

International Nuclear Information System (INIS)

Jongh, G. de; Bergers, M.; Boezeman, J.B.M.; Verhagen, A.R.; Mier, P.D.

1984-01-01

The lethal effect of UVA and PUVA radiation was studied in cultures of fresh and mature monocytes. UVA radiation alone was shown to possess a lethal effect at doses which are attained in the dermis in vivo. The synergistic action of 8-methoxypsoralen and UVA radiation predominated in PUVA radiation, but again a residual effect of UVA alone was demonstrated mathematically. Mature cells were less sensitive than fresh monocytes. The results indicate that a monolayer culture of non-dividing, mesenchymal cells offers considerable advantages over in vivo systems as a model for the study of phototoxicity. (author)

Absorption, Distribution, and Excretion of 14C-APX001 after Single-Dose Administration to Rats and Monkeys

OpenAIRE

Mansbach, Robert; Shaw, Karen J; Hodges, Michael R; Coleman, Samantha; Fitzsimmons, Michael E

2017-01-01

Abstract Background APX001 is a small-molecule therapeutic agent in clinical development for the treatment of invasive fungal infections (IFI). Methods The absorption, distribution and excretion profiles of [14C]APX001-derived radioactivity were determined in rats (albino and pigmented) and monkeys. Rats (some implanted with bile duct cannulae) were administered a single 100 mg/kg oral dose or a 30 mg/kg intravenous (IV) dose. Monkeys were administered a single 6 mg/kg IV dose. Samples of blo...

Improved metabolic control in tetrahydrobiopterin (BH4), responsive phenylketonuria with sapropterin administered in two divided doses vs. a single daily dose.

Science.gov (United States)

Kör, Deniz; Yılmaz, Berna Şeker; Bulut, Fatma Derya; Ceylaner, Serdar; Mungan, Neslihan Önenli

2017-07-26

Phenylketonuria (PKU) often requires a lifelong phenylalanine (Phe)-restricted diet. Introduction of 6R-tetrahydrobiopterin (BH4) has made a huge difference in the diets of patients with PKU. BH4 is the co-factor of the enzyme phenylalanine hydroxylase (PAH) and improves PAH activity and, thus, Phe tolerance in the diet. A limited number of published studies suggest a pharmacodynamic profile of BH4 more suitable to be administered in divided daily doses. After a 72-h BH4 loading test, sapropterin was initiated in 50 responsive patients. This case-control study was conducted by administering the same daily dose of sapropterin in group 1 (n=24) as a customary single dose or in two divided doses in group 2 (n=26) over 1 year. Mean daily consumption of Phe increased significantly after the first year of BH4 treatment in group 2 compared to group 1 (p<0.05). At the end of the first year of treatment with BH4, another dramatic difference observed between the two groups was the ability to transition to a Phe-free diet. Eight patients from group 2 and two from group 1 could quit dietary restriction. When given in two divided daily doses, BH4 was more efficacious than a single daily dose in increasing daily Phe consumption, Phe tolerance and the ability to transition to a Phe-unrestricted diet at the end of the first year of treatment.

Single dose of fluoxetine increases muscle activation in chronic stroke patients.

NARCIS (Netherlands)

van Genderen, Hanneke Irene; Nijlant, Juliette M.M.; van Putten, Michel Johannes Antonius Maria; Movig, Kris L.L.; IJzerman, Maarten Joost

2009-01-01

Objectives: This pilot study explores the influence of a single dose of fluoxetine (20 mg) on the muscle activation patterns and functional ability of the muscles in the lower part of the arm in chronic stroke patients. Methods: A crossover, placebo-controlled clinical trial was conducted in 10

A single 2 g oral dose of extended-release azithromycin for treatment of gonococcal urethritis.

Science.gov (United States)

Yasuda, Mitsuru; Ito, Shin; Kido, Akira; Hamano, Kiminari; Uchijima, Yutaka; Uwatoko, Noriyasu; Kusuyama, Hiroyuki; Watanabe, Akiko; Miyamura, Ryuzou; Miyata, Kazutoyo; Deguchi, Takashi

2014-11-01

We treated gonococcal urethritis in men with a single 2 g dose of azithromycin extended-release formulation (azithromycin-SR) to determine its microbiological outcomes and tolerability. We enrolled 189 Japanese men with gonococcal urethritis between April 2009 and December 2013. The patients were given a single 2 g dose of azithromycin-SR. Microbiological efficacy was evaluated by the results of the post-treatment molecular testing of Neisseria gonorrhoeae. MIC testing was performed only for pretreatment isolates of N. gonorrhoeae collected from the patients. We evaluated 130 patients for microbiological outcomes. Of these patients, 122 (93.8%) were judged to be microbiologically cured on the basis of negative test results. All isolates for which the azithromycin MICs were ≤0.25 mg/L were eradicated, whereas 5 of 12 isolates for which the MICs were 1 mg/L persisted after the treatment. Forty-six adverse events occurred in 41 patients. However, all adverse events were classified as mild. The eradication rate of N. gonorrhoeae was 93.8% in men with gonococcal urethritis treated with a single 2 g dose of azithromycin-SR. The breakpoint MIC of a 2 g dose of azithromycin-SR for gonococcal urethritis associated with clinical treatment failures appeared to be 1 mg/L. With regard to side effects of higher doses of azithromycin, the 2 g dose of azithromycin-SR appeared to improve tolerability. However, the widespread use of a high-dose regimen of azithromycin might lead to the development of further resistance to azithromycin. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Single dose oral piroxicam for acute postoperative pain

Science.gov (United States)

Moore, R Andrew; Edwards, Jayne; Loke, Yoon; Derry, Sheena; McQuay, Henry J

2014-01-01

Background This is an updated version of the original Cochrane review published in Issue 2, 2000. Piroxicam is a non-steroidal anti-inflammatory drug (NSAID) with analgesic properties, and is used mainly for treating rheumatic disorders. Some drugs have been directly compared against each other within a trial setting to determine their relative efficacies, whereas other have not. It is possible, however, to compare analgesics indirectly by examining the effectiveness of each drug against placebo when used in similar clinical situations. Objectives To determine the analgesic efficacy and adverse effects of single-dose piroxicam compared with placebo in moderate to severe postoperative pain. To compare the effects of piroxicam with other analgesics. Search methods Published studies were identified from systematic searching of MEDLINE, Biological Abstracts, EMBASE, CENTRAL and the Oxford Pain Relief Database in December 2007. Additional studies were identified from the reference lists of retrieved reports. Selection criteria The following inclusion criteria were used: full journal publication, randomised placebo controlled trial, double-blind design, adult participants, postoperative pain of moderate to severe intensity at the baseline assessment, postoperative administration of oral or intramuscular piroxicam. Data collection and analysis Summed pain intensity and pain relief data were extracted and converted into dichotomous information to yield the number of participants obtaining at least 50% pain relief. This was used to calculate estimates of relative benefit and number-needed-to-treat-to-benefit (NNT) for one participant to obtain at least 50% pain relief. Information was collected on adverse effects and estimates of relative risk and number-needed-to-treat-to-harm (NNH) were calculated. Main results In this update no further studies were found. The original search identified three studies (141 participants) which compared oral piroxicam 20 mg with placebo and

Compendium of Single Event Effects, Total Ionizing Dose, and Displacement Damage for Candidate Spacecraft Electronics for NASA

Science.gov (United States)

LaBel, Kenneth A.; OBryan, Martha V.; Chen, Dakai; Campola, Michael J.; Casey, Megan C.; Pellish, Jonathan A.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Ladbury, Raymond L.;

Effects of β-arabinofuranosyladenine on the growth and repair of potentially lethal damage in Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Iliakis, G.

1980-01-01

β-D-Arabinofuranosyladenine (β-araA) inhibit the growth of Ehrlich ascites tumor cells by selective inhibition of DNA polymerases. RNA and protein synthesis are not significantly affected. Addition of β-araA to the cells after irradiation resulted in a concentration-dependent decrease in survival, presumably due to the inhibition of the repair of potentially lethal damage. Since β-araA selectively inhibits DNA polymerases it is suggested that repair of potentially lethal damage involves steps at the DNA level which require some polymerization. These repair steps take place in the DNA with a velocity comparable to that of the repair of potentially lethal damage. The inhibition of the repair of potentially lethal damage by β-araA was modified by the addition of deoxyadenosine; this supports the finding that β-araA acts competitively against dATP at the molecular level. The inhibition of the repair of potentially lethal damage by β-araA, which is partly reversible, resulted in a concentration-dependent modification of the survival curve. At low concentrations of β-araA a dose-modifying decrease in survival was observed. At higher concentrations (more than 12 μM) the decrease in survival resulted in a decrease of the shoulder width of the survival curve. Eventually an exponential curve was obtained. We suggest therefore that the shoulder of the survival curve results from some repair or potentially lethal damage. Preliminary information has been obtained on the time course of this repair

Lethal and sub-lethal effects of five pesticides used in rice farming on the earthworm Eisenia fetida

NARCIS (Netherlands)

Rico, Andreu; Sabater, Consuelo; Castillo, María Ángeles

2016-01-01

The toxicity of five pesticides typically used in rice farming (trichlorfon, dimethoate, carbendazim, tebuconazole and prochloraz) was evaluated on different lethal and sub-lethal endpoints of the earthworm Eisenia fetida. The evaluated endpoints included: avoidance behaviour after an exposure

Lethal Epistaxis.

Science.gov (United States)

Byard, Roger W

2016-09-01

Epistaxis or nosebleed refers to bleeding from the nostrils, nasal cavity, or nasopharynx. Occasional cases may present with torrential lethal hemorrhage. Three cases are reported to demonstrate particular features: Case 1: A 51-year-old woman with lethal epistaxis with no obvious bleeding source; Case 2: A 77-year-old man with treated nasopharyngeal carcinoma who died from epistaxis arising from a markedly neovascularized tumor bed; Case 3: A 2-year-old boy with hemophilia B who died from epistaxis with airway obstruction in addition to gastrointestinal bleeding. Epistaxis may be associated with trauma, tumors, vascular malformations, bleeding diatheses, infections, pregnancy, endometriosis, and a variety of different drugs. Careful dissection of the nasal cavity is required to locate the site of hemorrhage and to identify any predisposing conditions. This may be guided by postmortem computerized tomographic angiography (PCTA). Despite careful dissection, however, a source of bleeding may never be identified. © 2016 American Academy of Forensic Sciences.

Single fixed-dose oral dexketoprofen plus tramadol for acute postoperative pain in adults.

Science.gov (United States)

Derry, Sheena; Cooper, Tess E; Phillips, Tudor

2016-09-22

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. A new combination of dexketoprofen (a nonsteroidal anti-inflammatory drug) plus tramadol (an opioid) has been tested in acute postoperative pain conditions. It is not yet licensed for use. This review is one of a series on oral analgesics for acute postoperative pain. Individual reviews have been brought together in two overviews to provide information about the relative efficacy and harm of the different interventions. To assess the analgesic efficacy and adverse effects of a single fixed-dose of oral dexketoprofen plus tramadol, compared with placebo, for moderate to severe postoperative pain in adults, using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes. A secondary objective was to compare the combination with the individual analgesics alone. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via CRSO, MEDLINE via Ovid, and Embase via Ovid from inception to 31 May 2016. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries. Randomised, double-blind trials of oral dexketoprofen plus tramadol administered as a single oral dose, for the relief of acute postoperative pain in adults, and compared to placebo. Two review authors independently considered trials for inclusion in the review, examined issues of study quality and potential bias, and extracted data. For dichotomous outcomes, we calculated risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) for dexketoprofen plus tramadol, compared with placebo with 95% confidence intervals (CI). We collected information on the number of participants with at least 50% of

Lethal infection thresholds of Paenibacillus larvae for honeybee drone and worker larvae (Apis mellifera).

Science.gov (United States)

Behrens, Dieter; Forsgren, Eva; Fries, Ingemar; Moritz, Robin F A

2010-10-01

We compared the mortality of honeybee (Apis mellifera) drone and worker larvae from a single queen under controlled in vitro conditions following infection with Paenibacillus larvae, a bacterium causing the brood disease American Foulbrood (AFB). We also determined absolute P. larvae cell numbers and lethal titres in deceased individuals of both sexes up to 8 days post infection using quantitative real-time PCR (qPCR). Our results show that in drones the onset of infection induced mortality is delayed by 1 day, the cumulative mortality is reduced by 10% and P. larvae cell numbers are higher than in worker larvae. Since differences in bacterial cell titres between sexes can be explained by differences in body size, larval size appears to be a key parameter for a lethal threshold in AFB tolerance. Both means and variances for lethal thresholds are similar for drone and worker larvae suggesting that drone resistance phenotypes resemble those of related workers. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Characteristics of repair following very low doses

International Nuclear Information System (INIS)

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

1987-01-01

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

The effects of peritoneal dialysis on the single dose and steady state pharmacokinetics of valproic acid in a uremic epileptic child.

Science.gov (United States)

Orr, J M; Farrell, K; Abbott, F S; Ferguson, S; Godolphin, W J

1983-01-01

The pharmacokinetics of valproic acid (VPA) have been studied during peritoneal dialysis in a uremic male epileptic child following a single 500 mg dose and after multiple doses over 5 months (700 mg daily) of valproic acid as the syrup. Serum level decline was biphasic in both instances with a terminal half-life of 27.2 after the single dose and 10.2 h at steady-state. Total serum clearance was 0.0236 l/h/kg after the single dose and increased to 0.0408 l/h/kg after 5 months. Free (intrinsic) serum clearances were 0.1489 and 0.1518 l/h/kg and serum free fractions were 0.224 and 0.272 respectively for the single dose and steady-state studies. Peritoneal dialysis for periods of 12 or 24 h removed an average of 4.5% of the VPA dose.

The effects of gut commensal bacteria depletion on mice exposed to acute lethal irradiation

International Nuclear Information System (INIS)

Hou Bing; Xu Zhiwei; Zhang Chenggang

2007-01-01

The prevention and management of bacterial infection are the mainstays of therapies for irradiation victims. However, worries about adverse effects arise from gut commensal flora depletion owing to the broad-spectrum antibiotics treatment. In the present study, we investigated the effects of gut bacteria depletion on the mice receiving total-body irradiation (TBI) at a single dose of 12 Gy. One group of mice was merely exposed to TBI but was free of antibiotic treatment throughout the experiment, while the other two groups of mice were additionally given broad-spectrum antibiotics, either from 2 weeks before or immediately after irradiation. The survival time of each animal in each group was recorded for analysis. Results showed that the mean survival time of mice was longest in the group without antibiotic treatment and shortest in the group treated with broad-spectrum antibiotics from 2 weeks before TBI. In conclusion, our data suggested that depletion of gut commensal bacteria with broad-spectrum antibiotics seemed deleterious for mammals receiving lethal TBI. (author)

A Systematic Review on Effect of Single-Dose Preoperative Antibiotics at Surgical Osteotomy Extraction of Lower Third Molars

DEFF Research Database (Denmark)

Marcussen, Karoline Brørup; Laulund, Anne Sofie; Jørgensen, Henrik L

2016-01-01

PURPOSE: We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of a single dose of preoperative antibiotic administered perorally, intravenously, intramuscularly, or topically for preventing infection and alveolar osteitis in lower third molar...... that penicillin V was effective in reducing the incidence of alveolar osteitis (OR = 0.1; 95% CI, 0.03 to 0.30; P ≤ .0001). CONCLUSIONS: A single oral dose of 2 g of amoxicillin before lower third molar osteotomy surgical extraction significantly decreased the incidence of SSI. A single dose of 0.8 g...... of penicillin V before lower third molar osteotomy surgical extraction significantly decreased the incidence of alveolar osteitis....

Monte Carlo dose calculation of microbeam in a lung phantom

International Nuclear Information System (INIS)

Company, F.Z.; Mino, C.; Mino, F.

1998-01-01

Full text: Recent advances in synchrotron generated X-ray beams with high fluence rate permit investigation of the application of an array of closely spaced, parallel or converging microplanar beams in radiotherapy. The proposed techniques takes advantage of the hypothesised repair mechanism of capillary cells between alternate microbeam zones, which regenerates the lethally irradiated endothelial cells. The lateral and depth doses of 100 keV microplanar beams are investigated for different beam dimensions and spacings in a tissue, lung and tissue/lung/tissue phantom. The EGS4 Monte Carlo code is used to calculate dose profiles at different depth and bundles of beams (up to 20x20cm square cross section). The maximum dose on the beam axis (peak) and the minimum interbeam dose (valley) are compared at different depths, bundles, heights, widths and beam spacings. Relatively high peak to valley ratios are observed in the lung region, suggesting an ideal environment for microbeam radiotherapy. For a single field, the ratio at the tissue/lung interface will set the maximum dose to the target volume. However, in clinical application, several fields would be involved allowing much greater doses to be applied for the elimination of cancer cells. We conclude therefore that multifield microbeam therapy has the potential to achieve useful therapeutic ratios for the treatment of lung cancer

Effects of DDE and PCB (Aroclor 1260) on experimentally poisoned little brown bats (Myotis lucifugus): Lethal brain concentrations

Science.gov (United States)

Clark, D.R.; Stafford, C.J.

1981-01-01

Adult female little brown bats (Myotis lucifugus) were collected in a church attic in North East, Cecil County, Md. Mealworms (Tenebrio molitor) containing organochlorine pollutants were fed to the bats as follows: 5 bats were dosed at 480 ppm DDE, 12 at 150 ppm DDE, 5 at 1000 ppm polychlorinated biphenyl (PCB; Aroclor 1260), and 12 at 15 ppm PCB. Seven other bats were fed untreated mealworms. The objective was to elevate brain levels of DDE and PCB to lethality and measure these concentrations. During 40 d of dosage, one DDE-dosed bat and two PCB-dosed bats died after exhibiting the prolonged tremor that characterizes organochlorine poisoning. After dosage, surviving bats were starved to elevate brain levels of toxicants, and three additional DDE-dosed bats had tremors before dying. The mean brain concentration of DDE diagnostic of death was estimated as 603 ppm, range 540-670 ppm. This mean is 16-18% higher than means for Mexican free-tailed bats (Tadarida brasiliensis) and common grackles (Quiscalus quiscula), and may indicate less sensitivity. Lethal brain concentrations of Aroclor 1260 were 1300 and 1500 ppm. Such values appear to be higher than values (Aroclor 1254) for brown-headed cowbirds (Molothrus ater). During starvation, DDE-dosed bats lost weight about 24% faster than controls. If smaller amounts of stored DDE cause increases in metabolic rates of nonfeeding bats, as during hibernation or migration, the result could be premature energy depletion and increased mortality.

Single-dose monomeric HA subunit vaccine generates full protection from influenza challenge

CSIR Research Space (South Africa)

Mallajosyula, JK

2014-03-01

Full Text Available 50% survival, or 100% survival with adjuvant, compared with 10% survival after vaccination with a commercially available H 1 N 1 vaccine. TMV-HA is an effective dose-sparing influenza vaccine, using a single-step process to rapidly generate large...

Sources of variability in OSL dose measurements using single grains of quartz

DEFF Research Database (Denmark)

Thomsen, Kristina Jørkov; Murray, A.S.; Bøtter-Jensen, L.

2005-01-01

spread. In this preliminary study, dose distributions have been studied using single grains of heated and laboratory irradiated quartz. By heating the sample, the contribution from incomplete zeroing was excluded and at the same time the sample was sensitised. The laboratory gamma irradiation...

Effects of a preovulatory single low dose of mifepristone on ovarian function

NARCIS (Netherlands)

van der Stege, Jolande G.; Pahl-van Beest, Elske H.; Beerthuizen, Rob J. C. M.; van Lunsen, Rik H. W.; Scholten, Piet C.; Bogchelman, Dick H.

Objectives To investigate the effect of a single low dose of mifepristone on ovarian function, when administered in the preovulatory period. Methods Healthy women with regular menstrual cycles were studied during two consecutive menstrual cycles. Either mifepristone or placebo was given in a

Dominant lethals following administration of tritium (THO) to rat males

International Nuclear Information System (INIS)

Yagova, A.; Baev, I.; Bajrakova, A.

1976-01-01

Adult rat males were given a single intraperitoneal tritium (THO) injection at 0,01 or 0,001 mCi/g body weight (1/100 or 1/1000 of LDsub(50/30), respectively). Twelve days after treatment each male was mated to 3-5 intact females, and the latter were replaced by fresh ones every 12 following days over a 120-day period. Mated females were killed to score conceptions, corpora lutea, and live and dead embryos. Estimations were made of F 1 prenatal death rate (according to Bateman, 1958) and the frequency of induction of dominant lethal mutations (according to Roehrborn, 1970). The results observed indicated paternal exposure to tritium (THO) to produce dominant lethals both in pre- and post-meiotic germ cells in the rat. The extent of the genetic damage studied was found to depend on the amount of activity administered as well as on the time interval between treatment and conception. (author)

Optimizing a single fixed dose of Iodine-131 in Graves' Disease (An Experience)

International Nuclear Information System (INIS)

Khan, S.H.

2007-01-01

Full text: Kashmir is a Himalayan mountain state of India enclosed by high snow capped ridges of Pir Panjal Mountains at an average height of 4000-5000 meters above the sea level. For most of the 4 million inhabitants in this land locked valley, agriculture horticulture and handcrafts are the main source of income. Due to long and severe winters the terraced farming on the mountain slopes yield just a single crop of rice which is barely sufficient to meet the local needs of this staple diet. People are relatively poor with low annual per capita income. Goiter is endemic in the Valley of Kashmir. In a published report the overall prevalence of goiter among the school going children in Kashmir between the ages of 5 years is 45.2% (+ SEM) with urinary iodine excretion of 49 + 3.55 μg per gram of creatinine. The extremely shy people of Kashmir are casual towards the aesthetic aspects of their goiters but nevertheless seek medical advice when associated with physical symptoms. In a published study of 203 patients of thyrotoxicosis from Kashmir, Graves' disease was the commonest cause, accounting for 63% of patients. One hundred and twentyone patients of Graves' disease were prospectively studied for their response to a single fixed dose of I-131. Patients were randomly treated with two different fixed doses of I- 131. Sixty four patients belonging to Group-I received a fixed dose of 185 MBq (Low Dose) and 57 patients belonging to Group -2 received 370 MBq (High Dose) of I- 131. Following therapy all patients were evaluated at 3 months. Patients with normal or reduced thyroid hormone levels were termed as responders and those with persistently elevated levels of thyroid hormone were termed as non responders. The response rates among the two groups were analyzed for their statistical significance. Patients treated with the high fixed dose of 370 MBq revealed good response to therapy achieving a rate of 91.22%, while the response rate in the group of patients treated with

Functional and morphological changes in pig skin after single or fractionated doses in x rays

International Nuclear Information System (INIS)

Young, C.M.A.; Hopewell, J.W.

1982-01-01

The flank skin of pigs has been treated with either single or fractionated doses of x-irradiation. A single dose (2070 cGy) was compared with treatment given as 6 fractions in 18 days (6f/18 days; 3780 cGy) or 30 fractions in 39 days (30f/39 days; 8000 cGy). The doses were selected on the basis that similar levels of late tissue damage would result. Radiation induced changes in the skin were assessed by observing the skin reactions and by the measurement of isotope clearance (functional study), relative field contraction, dermal and epidermal thickness and dermal vascular density (morphological studies). In the three treatment groups the early radiation reaction varied considerably. In the first wave reaction (3 to 6 weeks after treatment) bright red erythema was recorded in many fields but moist desquamation developed only in the 30f/39 days treatment group. The second wave (10-16 weeks) was characterized by an ischemic mauve/dusky reaction. Dermal necrosis developed in 50% of the single dose fields. In the 30f/39 days regimen persistent moist desquamation progressed to dermal necrosis. Neither desquamation nor necrosis developed after 6f/18 days. Different levels of vascular damage in the dermis were assessed using an isotope clearance technique; for example in the early reaction significant changes were recorded in the papillary dermis (faster clearance) prior to the development of moist desquamation (30f/39 days) and in the reticular dermis (slower clearance) before necrosis (single dose). Changes in clearance rates have been correlated with changes in the vascular density and thickness of the dermis. Between 26 and 52 weeks (the late reaction) relative field contraction was slightly greater in the 30f/39 days group than in the other treatment groups

Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

International Nuclear Information System (INIS)

Leith, J.L.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Walton, R.E.; Woodruff, K.H.; Howard, J.

1980-01-01

The response of rat spinal cord to irradiation with accelerated heavy ions, in particular carbon and neon ions has been studied. Two different ionization regions in the modified Bragg curve for each ion have been studied for both single and fractionated exposures. We have defined the paralytic response as a function of dose and dose per fraction, and we have determined RBE and repair values. The response of rat spinal cord is both dose and LET dependent, which allows the derivation of RBE and repair values

Lethal congenital contracture syndrome (LCCS) and other lethal arthrogryposes in Finland--an epidemiological study.

Science.gov (United States)

Pakkasjärvi, Niklas; Ritvanen, Annukka; Herva, Riitta; Peltonen, Leena; Kestilä, Marjo; Ignatius, Jaakko

2006-09-01

Arthrogryposis multiplex congenita is a heterogeneous group of disorders characterized by multiple contractures with an estimated frequency of 1 in 3,000 births. With improving diagnostic methods, increasing numbers of fetuses with arthrogryposis are found. The pathogenetic mechanisms are relatively well known but the epidemiology and genetics of the prenatally lethal forms of arthrogryposis are less well known. In this study we collected all cases of a multiple contractures diagnosed in Finland during 1987-2002 including live born infants, stillbirths, and terminated pregnancies. Ninety-two cases of 214 suffered intrauterine demise (68 selective pregnancy terminations and 24 stillbirths) and 58 died in infancy. In 141 out of these cases the diagnosis could be included within lethal arthrogryposes, with a prevalence of 1 in 6,985 (1.43/10,000) births. Of these, 59 had spinal cord pathology at autopsy and thus were of neurogenic origin. Thirty-nine cases had lethal congenital contracture syndrome (LCCS) clinically characterized by total immobility of the fetus at all ultrasound examinations (12 weeks or later), multiple joint contractures in both upper and lower limbs, hydrops, and fetal death before the 32nd week of pregnancy. LCCS is noted as a unique Finnish disorder with a prevalence of 1 in 25,250 (0.40/10,000) births and is a major cause of lethal arthrogryposis in Finland.

Cell kinetic changes in the follicular epithelium of pig skin after irradiation with single and fractionated doses of X rays

International Nuclear Information System (INIS)

Morris, G.M.; Hopewell, J.W.

1989-01-01

Changes in cell kinetics of the follicular epithelium of the pig were studied after x-irradiation with single and fractionated doses (30 fractions/39 days) and compared with previous epidermal data. In the follicular epithelium there was an initial degenerative phase, when the rate of cell depletion was independent of radiation dose and mode of administration. Repopulation was seen between the 14th and 18th days after single doses (15 or 20 Gy) and by the 28th day after the start of irradiation with fractionated doses (52.3-80.0 Gy). The degree of cell depletion and subsequent rate of repopulation were independent of dose. The regenerative phase was characterized by an increased cell proliferation. Islands of cells with appearance similar to cells in the normal follicular epithelium, were seen 18 days after a single dose of 20 Gy and 42 days after the start of fractionated irradiation. Compared with the epidermis, the follicular epithelium exhibited considerably less evidence of damage after both single and fractionated doses. There was a lower incidence of degenerate cells and reduced levels of cell depletion in the follicular epithelium. (author)

Sources of variability in OSL dose measurements using single grains of quartz

International Nuclear Information System (INIS)

Thomsen, K.J.; Murray, A.S.; Boetter-Jensen, L.

2005-01-01

In luminescence-based measurements of dose distributions in unheated mineral samples, the observed spread in dose values is usually attributed to four main factors: fluctuations in the number of photons counted, incomplete zeroing of any prior trapped charge (including signals arising from thermal transfer), heterogeneity in dosimetry, and instrument reproducibility. For correct interpretation of measured dose distributions in retrospective dosimetry, it is important to understand the relative importance of these components, and to establish whether other factors also contribute to the observed spread. In this preliminary study, dose distributions have been studied using single grains of heated and laboratory irradiated quartz. By heating the sample, the contribution from incomplete zeroing was excluded and at the same time the sample was sensitised. The laboratory gamma irradiation was designed to deliver a uniform dose to the sample. Thus it was anticipated that statistical fluctuations in the number of photons counted and instrument reproducibility, both quantifiable entities, should be able to account for all the observed variance in the measured dose distributions. We examine this assumption in detail, and discuss the origins and importance of the residual variance in our data

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

Evaluation of sphingolipids in Wistar rats treated to prolonged and single oral doses of fumonisin b₁.

Science.gov (United States)

Direito, Glória M; Almeida, Adriana P; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

2009-01-01

The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B(1) (FB(1)). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB(1). Prolonged exposure to FB(1) caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB(1). Animals receiving a single dose of FB(1) presented variations in Sa and So levels and in the Sa/So ratio.

Genetic effects of low x-ray doses. Progress report, October 1, 1975--September 30, 1976

International Nuclear Information System (INIS)

Abrahamson, S.; Meyer, H.U.

1976-09-01

Experiments on dose-kinetics of x-ray induced sexlinked lethal mutations in Drosophila oogonia were continued. A wide range of doses was tested, with special emphasis on the low-dose range (20 to 500R). This year more data were added for O R, 200, 500, 1500R and some high doses. Oogonia of adult females were irradiated, and only one daughter from each experimental parent-female was analyzed for a new lethal in her maternal X-chromosome. Thus no clusters of mutations of identical origin are encountered. The extensive accumulated data do not support the linearity principle, firmly established for recessive mutations induced in mature spermatozoa for high doses down to very low x-ray doses. A mathematical model describing the mutational yield is included that suggests that recessive mutations, like chromosome aberrations, result from both one-track and two-track events, with the latter playing an increasingly important role at higher doses

Single dose toxicity and biodistribution studies of [{sup 18}F] fluorocholine

Energy Technology Data Exchange (ETDEWEB)

Campos, Danielle C.; Santos, Priscilla F., E-mail: dcc@cdtn.br [Universidade Federal de Minas Gereais (INCT-MM/UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina. Instituto Nacional de Ciencia e Tecnologia de Medicina Molecular; Silveira, Marina B.; Ferreira, Soraya Z.; Malamut, Carlos; Silva, Juliana B. da, E-mail: radiofarmacoscdtn@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos; Souza, Cristina M.; Campos, Liliane C.; Ferreira, Enio; Araujo, Marina R.; Cassali, Geovanni D., E-mail: cassalig@icb.ufmg.br [Universidade Federal de Minas Gerais (LPC/UFMG), Belo Horizonte, MG (Brazil). Lab. de Patologia Comparada

2013-07-01

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

Concentrations of amoxicillin and clindamycin in teeth following a single dose of oral medication.

Science.gov (United States)

Schüssl, Yvonne; Pelz, Klaus; Kempf, Jürgen; Otten, Jörg-Elard

2014-01-01

The main purpose of this study is the detection of amoxicillin and clindamycin concentrations in teeth. Eleven patients received 2 g of amoxicillin, and 11 patients received 600 mg of clindamycin in a single dose of oral medication at least 60 min prior to tooth extraction due to systemic diseases. The concentrations were determined in crowns and roots separately using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Amoxicillin (13 samples) and clindamycin (12 samples) were detected in the samples of the root and crown preparations of the extracted teeth. The mean concentration of amoxicillin was 0.502 μg/g in the roots and 0.171 μg/g in the crowns. The mean concentration of clindamycin was 0.270 μg/g in the roots and 0.064 μg/g in the crowns. A single dose of oral amoxicillin and clindamycin leads to concentrations of both antibiotics in teeth which exceed the minimal inhibition concentration of some oral bacteria. The proof of antibacterial activity in dental hard tissue after oral single-dose application is new. The antimicrobial effect of amoxicillin and clindamycin concentrations in roots of teeth may be of clinical relevance to bacterial reinfection from dentinal tubules.

Fixed-dose combinations of drugs versus single-drug formulations for treating pulmonary tuberculosis

Science.gov (United States)

Gallardo, Carmen R; Rigau Comas, David; Valderrama Rodríguez, Angélica; Roqué i Figuls, Marta; Parker, Lucy Anne; Caylà, Joan; Bonfill Cosp, Xavier

2016-01-01

Background People who are newly diagnosed with pulmonary tuberculosis (TB) typically receive a standard first-line treatment regimen that consists of two months of isoniazid, rifampicin, pyrazinamide, and ethambutol followed by four months of isoniazid and rifampicin. Fixed-dose combinations (FDCs) of these drugs are widely recommended. Objectives To compare the efficacy, safety, and acceptability of anti-tuberculosis regimens given as fixed-dose combinations compared to single-drug formulations for treating people with newly diagnosed pulmonary tuberculosis. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL, published in the Cochrane Library, Issue 11 2015); MEDLINE (1966 to 20 November 2015); EMBASE (1980 to 20 November 2015); LILACS (1982 to 20 November 2015); the metaRegister of Controlled Trials; and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), without language restrictions, up to 20 November 2015. Selection criteria Randomized controlled trials that compared the use of FDCs with single-drug formulations in adults (aged 15 years or more) newly diagnosed with pulmonary TB. Data collection and analysis Two review authors independently assessed studies for inclusion, and assessed the risk of bias and extracted data from the included trials. We used risk ratios (RRs) for dichotomous data and mean differences (MDs) for continuous data with 95% confidence intervals (CIs). We attempted to assess the effect of treatment for time-to-event measures with hazard ratios and their 95% CIs. We used the Cochrane 'Risk of bias' assessment tool to determine the risk of bias in included trials. We used the fixed-effect model when there was little heterogeneity and the random-effects model with moderate heterogeneity. We used an I² statistic value of 75% or greater to denote significant heterogeneity, in which case we did not perform a

Absorbed dose optimization in the microplanar beam radiotherapy

International Nuclear Information System (INIS)

Company, F.Z.; Jaric, J.; Allen, B.J.

1996-01-01

Full text: Recent advances in synchrotron generated X-ray beams with high fluence rate, small divergence and sharply defined microbeam margins permit investigation of the application of an array of closely spaced, parallel or converging microbeams for radiotherapy. The proposed technique takes advantage of the repair mechanism hypothesis of capillary endothelial cells between alternate microbeam zones, which regenerates the lethally irradiated capillaries. Unlike a pencil beam, more accurate dose calculation, beam width and spacing are essential to minimise radiation damage to normal tissue cells outside the target. The absorbed dose between microbeam zones should be kept below the threshold for irreversible radiation damage. Thus the peak-to-valley ratio for the dose distribution should be optimized. The absorbed dose profile depends on the energy of the incident beam and the composition and density of the medium. Using Monte Carlo computations, the radial absorbed dose of single 24 x 24 μm 2 cross-section X-ray beams of different energies in a tissue/lung/tissue phantom was investigated. The results indicated that at 100 keV, closely spaced square cross-sectional microbeams can be applied to the lung. A bundle of parallel 24 μm-wide planar microbeams spaced at 200 μm intervals provides much more irradiation coverage of tissue than is provided by a bundle of parallel, square cross-sectional microbeam, although the former is associated with much smaller Peak (maximum absorbed dose on the beam axis) -to-Valley ( minimum interbeam absorbed dose ) ratios than the latter. In this study the lateral and depth dose of single and multiple microplanar beams with beam dimensions of width 24 μm and 48 μm and height 2-20 cm with energy of 100 keV in a tissue/lung/tissue phantom are investigated. The EGS4 Monte Carlo code is used to calculate dose profiles at different depths and bundles of beams (2 x 2 cm 2 to 20 x 20 cm 2 square cross section) with a 150 μm 200 μm and

Single-shot, high-dose rabbit ATG for rejection prophylaxis after kidney transplantation

NARCIS (Netherlands)

R. Zietse (Bob); E.P.M. van Steenberge (E. P M); C.J. Hesse (Cees); L.B. Vaessen (L.); J.N.M. IJzermans (Jan); W. Weimar (Willem)

1993-01-01

textabstractWe studied the effects of a single intravenous injection of rabbit ATG (RIVM, Bilthoven, The Netherlands) in a dose of 8 mg/kg body weight administered 6 h after kidney transplantation on graft survival, rejection incidence, T-cell subsets, and cost-effectiveness. A total of 58 (37

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-10-01

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

Radiotherapy for calcaneodynia. Results of a single center prospective randomized dose optimization trial

Energy Technology Data Exchange (ETDEWEB)

Ott, O.J.; Jeremias, C.; Gaipl, U.S.; Frey, B.; Schmidt, M.; Fietkau, R. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

2013-04-15

The aim of this work was to compare the efficacy of two different dose fractionation schedules for radiotherapy of patients with calcaneodynia. Between February 2006 and April 2010, 457 consecutive evaluable patients were recruited for this prospective randomized trial. All patients received radiotherapy using the orthovoltage technique. One radiotherapy series consisted of 6 single fractions/3 weeks. In case of insufficient remission of pain after 6 weeks a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. Endpoint was pain reduction. Pain was measured before, immediately after, and 6 weeks after radiotherapy using a visual analogue scale (VAS) and a comprehensive pain score (CPS). The overall response rate for all patients was 87 % directly after and 88 % 6 weeks after radiotherapy. The mean VAS values before, immediately after, and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 65.5 {+-} 22.1 and 64.0 {+-} 20.5 (p = 0.188), 34.8 {+-} 24.7 and 39.0 {+-} 26.3 (p = 0.122), and 25.1 {+-} 26.8 and 28.9 {+-} 26.8 (p = 0.156), respectively. The mean CPS before, immediately after, and 6 weeks after treatment was 10.1 {+-} 2.7 and 10.0 {+-} 3.0 (p = 0.783), 5.6 {+-} 3.7 and 6.0 {+-} 3.9 (p = 0.336), 4.0 {+-} 4.1 and 4.3 {+-} 3.6 (p = 0.257), respectively. No statistically significant differences between the two single dose trial arms for early (p = 0.216) and delayed response (p = 0.080) were found. Radiotherapy is an effective treatment option for the management of calcaneodynia. For radiation protection reasons, the dose for a radiotherapy series is recommended not to exceed 3-6 Gy. (orig.)

Controlled single-blind clinical evaluation of low-dose mammographic screen: film systems

International Nuclear Information System (INIS)

Sickles, E.A.; Genant, H.K.

1979-01-01

The ability of five low-dose mammographic screen-film systems to portray normal and abnormal breast structures was evaluated in parallel with a study of physical image properties. Single-blind evaluations of the visibility of normal breast architecture, mass lesions, and calcifications were made on the mammograms of 100 patients radiographed with each of the systems. There was increased noise and slightly poorer resolution of the faster recording systems, but there was no difference in final diagnostic impressions among the five systems. These results suggest that the faster systems will result in substantial dose reduction without sacrificing diagnostic accuracy

Single versus double dose praziquantel comparison on efficacy and Schistosoma mansoni re-infection in preschool-age children in Uganda

DEFF Research Database (Denmark)

Nalugwa, Allen; Nuwaha, Fred; Tukahebwa, Edridah Muheki

2015-01-01

BACKGROUND: Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel...... (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda. METHODOLOGY/PRINCIPAL FINDINGS: Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially...... all children were treated with a single standard oral dose 40 mg/kg body weight of PZQ. Two weeks later a second dose was administered to children in the double dose treatment arm. Side effects were monitored at 30 minutes to 24 hours after each treatment. Efficacy in terms of CRs and ERRs for the two...

Bronchodilator Efficacy of Single Doses of Indacaterol in Japanese Patients with COPD: A Randomised, Double-Blind, Placebo-Controlled Trial

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Motokazu Kato

Full Text Available ABSTRACT: Background: Indacaterol is an investigational, novel, inhaled once-daily ultra-long-acting beta-2 agonist for the treatment of chronic obstructive pulmonary disease (COPD. This study evaluated the 24-h bronchodilatory efficacy and safety of indacaterol in Japanese patients with COPD. Methods: This Phase-II, randomised, placebo-controlled, crossover study comprised four double-blind, single-dose treatment periods (washout between periods: 14-28 days. Japanese patients aged 40-75 years with moderate-to-severe COPD were randomised to receive single doses of indacaterol (150, 300, or 600 μg or placebo via a single-dose dry-powder inhaler. Efficacy (primary endpoint: standardised FEV1AUC22-24h and safety were assessed for 24 h post-dose in each treatment period. Results: Of the 50 patients randomised (92% male; mean age, 67.2 years, 45 completed the study. Standardised FEV1AUC22-24h was significantly higher for all indacaterol doses as compared with placebo, with clinically relevant differences of 130, 160, and 170 mL for 150, 300, and 600 μg, respectively (P < 0.001. The improvement in FEV1 was seen as early as 5 min post-dose with indacaterol and sustained for 24 h (P < 0.001 vs placebo at all time points. All indacaterol doses were well tolerated and showed no clinically meaningful effect on pulse rate, blood pressure, QTc interval, and laboratory parameters when compared with placebo. Conclusions: In the Japanese COPD population studied, single doses of indacaterol (150, 300, and 600 μg provided sustained 24-h bronchodilation, with onset of action within 5 min post-dose. All doses were well tolerated. These results are consistent with data from Caucasian populations. KEY WORDS: beta2-agonists, bronchodilator, COPD, efficacy, indacaterol

Increased apoptotic potential and dose-enhancing effect of gold nanoparticles in combination with single-dose clinical electron beams on tumor-bearing mice

International Nuclear Information System (INIS)

Chang Mengya; Chen Yuhung; Chang Chihjui; Chen Helen H-W; Wu Chaoliang; Shiau Aili

2008-01-01

High atomic number material, such as gold, may be used in conjunction with radiation to provide dose enhancement in tumors. In the current study, we investigated the dose-enhancing effect and apoptotic potential of gold nanoparticles in combination with single-dose clinical electron beams on B16F10 melanoma tumor-bearing mice. We revealed that the accumulation of gold nanoparticles was detected inside B16F10 culture cells after 18 h of incubation, and moreover, the gold nanoparticles were shown to be colocalized with endoplasmic reticulum and Golgi apparatus in cells. Furthermore, gold nanoparticles radiosensitized melanoma cells in the colony formation assay (P=0.02). Using a B16F10 tumor-bearing mouse model, we further demonstrated that gold nanoparticles in conjunction with ionizing radiation significantly retarded tumor growth and prolonged survival compared to the radiation alone controls (P<0.05). Importantly, an increase of apoptotic signals was detected inside tumors in the combined treatment group (P<0.05). Knowing that radiation-induced apoptosis has been considered a determinant of tumor responses to radiation therapy, and the length of tumor regrowth delay correlated with the extent of apoptosis after single-dose radiotherapy, these results may suggest the clinical potential of gold nanoparticles in improving the outcome of melanoma radiotherapy. (author)

The effect of sub-lethal damage repair and exchange on the final slope of cell survival curves

International Nuclear Information System (INIS)

Carlone, M.C.; Wilkins, D.E.; Raaphorst, G.P.

2003-01-01

Full text: The Lea-Catcheside dose rate protraction factor, G, is the most widely used model to describe the effects of dose rate on cell survival. In the linear quadratic formalism, this factor modifies the beta component of cell killing; G is greatest for acute irradiations while vanishing at low dose rates. We have found a simple compartmental model that can derive the Lea-Catcheside function. This compartmental model clearly shows that the G function can only be derived using a little known assumption: the diminution of sub-lethal damage due to exchange of repairable lesions is negligible compared to that due to repair. This assumption was explicitly stated by Lea, but it does not appear to have been restated or verified since very early work on cell survival. The implication of this assumption is that sub-lethal damage can be modeled without considering exchange, which is evidenced by the fact that the G function does not contain parameters relating to exchange. By using a new model that fully accounts for repair and exchange of sublethal lesions, a cell survival expression that has a modified G function, but that retains the linear quadratic formalism, can be obtained. At low doses, this new model predicts linear-quadratic behavior, but the behavior gradually changes to mono-exponential at high doses, which is consistent with experimental observations. Modeling cell survival of well-known survival curves using the modified linear quadratic model shows statistically significant improvement in the fits to the cell survival data as compared to best fits obtained with the linear quadratic model. It is shown that these improvements in fits are due to a superior representation of the high dose region of the survival curve

Efficacy of prophylactic single-dose therapy using fluoroquinolone for prostate brachytherapy

International Nuclear Information System (INIS)

Nomura, Takeo; Hirai, Kenichi; Yamasaki, Mutsushi; Inoue, Toru; Takahashi, Mika; Kawashima, Takayuki; Sato, Fuminori; Mimata, Hiromitsu

2012-01-01

There is little definitive evidence to guide the use of prophylactic antibiotics for prostate brachytherapy. The purpose of this study is to evaluate the incidence of postimplant infections in patients who receive antimicrobial prophylaxis with pazufloxacin (PZFX). A total of 84 patients who underwent prostate brachytherapy received a single intravenous dose of PZFX at 500 mg perioperatively for 1 day. No postimplant antibiotic medication was prescribed. Urinalysis, plasma white blood cell (WBC) count, and C reactive protein (CRP) levels were evaluated before the implantation, on the day after implantation, and on the 7th and 28th days after brachytherapy. None of the 84 patients (0.0%) developed a symptomatic urinary tract infection or had febrile infectious complications after brachytherapy. There were statistically significant elevations in the levels of erythrocytes, leukocytes, bacteria in urine, plasma WBC and CRP postoperatively, but these values did not exceed the normal range or were only slightly elevated on the day after brachytherapy (day 1) and on day 7. All laboratory examinations had returned to the normal range on day 28. Single-dose therapy with fluoroquinolone helps to prevent infections after prostate brachytherapy. (author)

Molecular analysis of two mouse dilute locus deletion mutations: Spontaneous dilute lethal20J and radiation-induced dilute prenatal lethal Aa2 alleles

International Nuclear Information System (INIS)

Strobel, M.C.; Seperack, P.K.; Copeland, N.G.; Jenkins, N.A.

1990-01-01

The dilute (d) coat color locus of mouse chromosome 9 has been identified by more than 200 spontaneous and mutagen-induced recessive mutations. With the advent of molecular probes for this locus, the molecular lesion associated with different dilute alleles can be recognized and precisely defined. In this study, two dilute mutations, dilute-lethal20J (dl20J) and dilute prenatal lethal Aa2, have been examined. Using a dilute locus genomic probe in Southern blot analysis, we detected unique restriction fragments in dl20J and Aa2 DNA. Subsequent analysis of these fragments showed that they represented deletion breakpoint fusion fragments. DNA sequence analysis of each mutation-associated deletion breakpoint fusion fragment suggests that both genomic deletions were generated by nonhomologous recombination events. The spontaneous dl20J mutation is caused by an interstitial deletion that removes a single coding exon of the dilute gene. The correlation between this discrete deletion and the expression of all dilute-associated phenotypes in dl20J homozygotes defines the dl20J mutation as a functional null allele of the dilute gene. The radiation-induced Aa2 allele is a multilocus deletion that, by complementation analysis, affects both the dilute locus and the proximal prenatal lethal-3 (pl-3) functional unit. Molecular analysis of the Aa2 deletion breakpoint fusion fragment has provided access to a previously undefined gene proximal to d. Initial characterization of this new gene suggests that it may represent the genetically defined pl-3 functional unit

Effect of single lithium doses on haemopoiesis regeneration after radiation exposure in mice

International Nuclear Information System (INIS)

Krajewski, K.

1988-01-01

The reported experiment failed to demonstrate any effect of single doses of lithium carbonate on haemopoiesis regeneration in experimental haematological syndrome of acute radiation sickness. The effects of gamma radiation on blood formation are shown. 3 figs., 6 refs. (author)

Mechanistic and single-dose in vivo therapeutic studies of Cry5B anthelmintic action against hookworms.

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Yan Hu

Full Text Available Hookworm infections are one of the most important parasitic infections of humans worldwide, considered by some second only to malaria in associated disease burden. Single-dose mass drug administration for soil-transmitted helminths, including hookworms, relies primarily on albendazole, which has variable efficacy. New and better hookworm therapies are urgently needed. Bacillus thuringiensis crystal protein Cry5B has potential as a novel anthelmintic and has been extensively studied in the roundworm Caenorhabditis elegans. Here, we ask whether single-dose Cry5B can provide therapy against a hookworm infection and whether C. elegans mechanism-of-action studies are relevant to hookworms.To test whether the C. elegans invertebrate-specific glycolipid receptor for Cry5B is relevant in hookworms, we fed Ancylostoma ceylanicum hookworm adults Cry5B with and without galactose, an inhibitor of Cry5B-C. elegans glycolipid interactions. As with C. elegans, galactose inhibits Cry5B toxicity in A. ceylanicum. Furthermore, p38 mitogen-activated protein kinase (MAPK, which controls one of the most important Cry5B signal transduction responses in C. elegans, is functionally operational in hookworms. A. ceylanicum hookworms treated with Cry5B up-regulate p38 MAPK and knock down of p38 MAPK activity in hookworms results in hypersensitivity of A. ceylanicum adults to Cry5B attack. Single-dose Cry5B is able to reduce by >90% A. ceylanicum hookworm burdens from infected hamsters, in the process eliminating hookworm egg shedding in feces and protecting infected hamsters from blood loss. Anthelmintic activity is increased about 3-fold, eliminating >97% of the parasites with a single 3 mg dose (∼30 mg/kg, by incorporating a simple formulation to help prevent digestion in the acidic stomach of the host mammal.These studies advance the development of Cry5B protein as a potent, safe single-dose anthelmintic for hookworm therapy and make available the information of how

Changes in activities of adaptive liver enzymes in rats after non-lethal x-irradiation

International Nuclear Information System (INIS)

Toropila, M.; Ahlersova, E.; Ahlers, I.; Benova, K.

1998-01-01

The effect of a single dose of whole-body X-irradiation of 2.39 Gy (250 R) on the activities of selected adaptive rat liver enzymes and blood serum corticosterone concentrations was followed for a period of 28 days. Rats of Wistar strain SPF breeding (VELAZ Prague) were used. Both irradiated and control animals were fed in pairs with the same amount of feed as was consumed by irradiated animals in the pilot experiment. The feed intake of irradiated animals decreased significantly until the fourth day. During the rest of the experimental period no significant differences were recorded in feed intake between the experimental and control groups. The activity of tyrosine aminotransferase (TAT) in the liver of irradiated animals increased, with the exception of the initial period. Similar changes were recorded in the activity of tryptophane-2-3 dioxygenase (TO). A significant increase on the third day and a significant decrease from the seventh day after irradiation was recorded in the activity of aspartate aminotransferase (AST). Similar changes were observed with alanine aminotransferase (ALT). It is necessary to stress that the activity of this enzyme decreased also on the first day after irradiation. Until the third day there was a marked increase of serum corticosterone in the irradiated animals. The results point not only towards significant changes to the parameters observed, caused by a non-lethal irradiation dose, but also towards the importance of the nutritional regime, so-called paired feeding

The Effect of Nicotine Administration on Physical and Psychological Signs of Withdrawal Syndrome Induced by Single or Frequent Doses of Morphine in Rats

OpenAIRE

Mohammad Allahtavakoli; Fatemeh Amin; Elham Hakimizadeh; Ali Roohbakhsh; Sayed Ali Haeri Rohani; Ahmad Taghavi Rafsanjani; Abbas Haghparast; Ali Shamsizadeh

2012-01-01

Introduction. Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Materials and methods. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later t...

Radiation hardening at 77 K in Zn and Cu single crystals at low doses

International Nuclear Information System (INIS)

Gonzalez, H.C.; Bisogni, E.A.

1980-01-01

There is controversy about radiation hardening phenomenon and its additivity with other hardening mechanisms. The purpose of this work is to contribute to the understanding of this subject, through measurements made in Zn and Cu single crystals. Post-irradiation measurements of yield stress of Zn, made on different single crystals, show a direct proportionality to the 0.5 power of the dose. It is determined that for a dose greater than 3.7 x 10 16 neutrons cm -2 s -1 there is always cleavage. The maximum critical resolved shear stress measured is about 8.82 MPa. In order to study additivity it is necessary to lower experimental errors. A micro tensile machine is designed to operate in the CNEA facility RA1 in a bath of liquid N 2 . Experimental measurements of yield stress with dose are carried out in-situ on the same single crystals. Experimental results on Cu and Zn show that radiation induced yield stress increases with a 0.5 power law. It must be taken into account that the definition of radiation induced yield stress stands for radiation created obstacles operating alone. The radiation induced yield stress adds algebraically to the athermal component of the initial yield stress but is not exactly additive to the other thermally activated mechanisms. A gradual transition from one to the other type of obstacles is observed. (author)

Pharmacokinetics of a telmisartan/rosuvastatin fixed-dose combination: a single-dose, randomized, open-label, 2-period crossover study in healthy Korean subjects.

Science.gov (United States)

Chae, Dong Woo; Son, Mijeong; Kim, Yukyung; Son, Hankil; Jang, Seong Bok; Seo, Jeong Min; Nam, Su Youn; Park, Kyungsoo

2015-10-01

As hypertension and dyslipidemia are frequent comorbidities, antihypertensive drugs and lipid-lowering agents are often prescribed together for their treatment. Telmisartan and rosuvastatin are widely used together to treat hypertension and dyslipidemia. A combination formulation of these two drugs would improve patient compliance due to ease of dosing. The purpose of this study was to assess bioequivalence of single-dose administration of a newly-developed fixed-dose combination (FDC) tablet containing telmisartan/rosuvastatin 80/20 mg (test treatment) and coadministration of a telmisartan 80-mg tablet and a rosuvastatin 20-mg tablet (reference treatment) in healthy Korean male volunteers. This was a single-dose, randomized, open-label, 2-period crossover study enrolling healthy males aged 20 - 50 years with BMI between 18.5 and 25 kg/m2. Each subject received a single dose of the reference and test treatments with a 14-day washout period. Blood sampling was performed at prespecified intervals for up to 72 hours after dosing. Primary pharmacokinetic parameters were Cmax, AUClast, and AUC0-∞ of telmisartan, rosuvastatin, and N-desmethyl rosuvastatin. Bioequivalence was assessed by determining whether the 90% confidence intervals (CIs) of the geometric mean ratios (test treatment/reference treatment) of these parameters were within the standard range of 80% to 125%. Adverse events were monitored via regular interviews with the subjects and by physical examinations. 60 subjects were enrolled and 55 completed the study. The 90% CIs of the geometric mean ratios of Cmax, AUClast, and AUC00-∞ were 0.9262-1.1498, 0.9294-1.0313, and 0.9312-1.0320 for telmisartan, 0.9041-1.0428, 0.9262-1.0085, and 0.9307-1.0094 for rosuvastatin, and 0.8718-1.0022, 0.8901-0.9904, and 0.8872-0.9767 for N-desmethyl rosuvastatin, respectively. There was no statistical difference in the incidence of adverse events (AEs) (all of which were mild or moderate) between the reference and test

Effects of DDE on experimentally poisoned free-tailed bats (Tadarida brasiliensis): Lethal brain concentrations

Science.gov (United States)

Clark, D.R.; Kroll, J.C.

1977-01-01

Adult female free-tailed bats (Tadarida brasiliensis) were collected at Bracken Cave, Texas, and shipped to the Patuxent Wildlife Research Center. Treated mealworms (Tenebrio molitor) containing 107 ppm DDE were fed to 17 bats; five other bats were fed untreated mealworms. After 40 days on dosage, during which one dosed bat was killed accidentally, four dosed bats were frozen and the remaining 17 were starved to death. The objective was to elevate brain levels of DDE to lethality and measure these concentrations. After the feeding period, dosed bats weighed less than controls. After starvation, the body condition of dosed bats was poorer than that of controls even though there was no difference in the amounts of carcass fat. During starvation, dosed bats lost weight faster than controls. Also, four dosed bats exhibited the prolonged tremoring that characterizes DDE poisoning. DDE increased in brains of starving bats as fat was metabolized. The estimated mean brain concentration of DDE diagnostic of death was 519 ppm with a range of 458-564 ppm. These values resemble diagnostic levels known for two species of passerine birds, but they exceed published levels for two free-tailed bats from Carlsbad Caverns, New Mexico.

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Misonidazole cytotoxicity in vivo: a comparison of large single doses with smaller doses and extended contact of the drug with tumor cells

International Nuclear Information System (INIS)

Conroy, P.J.; Sutherland, R.M.; Passalacqua, W.

1980-01-01

Experiments were performed to determine the kinetics and magnitude of misonidazole cytotoxicity in EMT6/Ro tumors using an in vivo-in vitro clonogenicity assay. A comparison was made between the cytotoxic effects of large single doses with smaller doses of misonidazole administered ip and those produced on extended contact of the drug with tumor cells using a continuous iv drug infusion system. After a single ip dose of 1 mg/g, cytotoxicity was maximum at 18 to 24 h; by 72 h the clonogenic cells per tumor had returned to control levels. The maximum cytotoxicity was greater (a decrease of 10 times) if the animals were kept at 37 0 C compared with ambient conditions (a decrease of 4.5 times) where the body temperature would decrease due to the drug. A dose-response curve performed with the animals at 37 0 C showed no significant cytotoxicity at 18 h after single ip doses of 0.5 mg/g or less. Other experiments were carried out at 37 0 C using a drug continuous infusion system. Two profiles were studied: (a) continuous constant rate infusion over 3 days of constant serum and tumor levels of both 100 and 200 μg/ml and (b) continuous variable rate infusion where the maximum serum levels reached 80 or 200 μg/ml after 2 to 4 h and decayed with a half-life of 12 h as in humans. Significant cytotoxicity was obtained under both of these conditions. Maximum cytotoxicity occurred at about 24 h in both types of experiments and amounted to decreases of clonogenic tumor cells of 4.5 and 7 times for 100 and 200 μg/ml, respectively, after constant rate infusion and 2 to 4 times for 80 and 200 μg/ml, respectively, after variable rate infusion. Because of the relatively rapid recovery in the number of clonogenic tumor cells by 72 h, the cytotoxic effects were not reflected as changes in tumor size even when the animals were maintained at 37 0 C

Interpretation of proton relative biological effectiveness using lesion induction, lesion repair, and cellular dose distribution

International Nuclear Information System (INIS)

Paganetti, H.

2005-01-01

Phenomenological biophysical models have been successfully used to estimate the relative biological effectiveness (RBE) of ions. The predictive power of these models is limited because they require measured dose-response data that are not necessarily available for all clinically relevant end points. Furthermore, input parameters often lack mechanistic interpretation. In order to link RBE to more fundamental biological parameters we combine the concepts of two well-established biophysical models, i.e., the phenomenological 'track structure' model and the more mechanistic 'lethal lesion/potentially lethal lesion' (LPL) model. We parametrize a relation between RBE, dose homogeneity in the cell nucleus and induction rates for different lesion types. The macroscopic dose-response relationship is described in the LPL model and the microscopic, subcellular, relationship is determined by the local dose deposition pattern. The formalism provides a framework for a mechanistic interpretation of RBE values

Female Rats are Less Susceptible during Puberty to Lethal Effects of Percutaneous Exposure to VX

Science.gov (United States)

2015-12-17

lethal dose determination for percutaneous exposure to soman and VX in guinea pigs and the effectiveness of decontamination with M291 SDK or SANDIA...di-isopropylamino) ethyl] methyl phosphonthioate) through pig , human and guinea pig skin in vitro, Toxicol. In Vitro 20 (2006) 1532–1536. [6] R... production and transepidermal water loss [TEWL]) change with age [3,14,15]. As reviewed in Ref. [28], the barrier function of the stratum corneum is

Dual-sided reading versus single-sided reading: comparison of image quality and radiation dose between the two computed radiography system

International Nuclear Information System (INIS)

Song Shaojuan; Qi Hengtao; Zhao Yongxia; Jiao Fanglian

2007-01-01

Objective: To assess and compare the difference in image quality and exposure dose between single-sided reading image plate (IP) and dual-sided reading IP. Methods: A contrast-detail phantom CDRAD 2.0 was exposed by single-sided and dual-sided reading IP with different mAs sets. The entrance surface doses were recorded for all images. Images were then presented to two radiologists on a high resolution monitor of diagnosis workstation. The image quality figure (IQF) was measured for each image. Statistical analysis was performed using Spearman's correlation test and Wilcoxon signed-rank test to compare the difference in image quality and exposure dose between single-sided IP and dual-sided reading IP. Results: With different tube current dosage of 5.6, 12.0, 20.0, 25.0, and 40.0 mAs, IQF values of single-sided reading IP were 47.95, 37.68, 34.31, 28.61, and 24.65, respectively, while those of dual- sided reading IP were 38.83, 29.81, 29.65, 25.16, and 21.43, respectively. The IQF difference between them showed statistical significance (P<0.05). Conclusion: Image quality of dual-sided reading IP has been proved to be far superior to that of single-sided reading IP, in particular for low contrast detail. The image quality of single-sided reading IP is similar to that of dual-sided reading IP only at high dose levels. The clinical application of dual-sided reading IP will reduce the exposure dose by about 25% compared with single-sided reading IP. (authors)

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

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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.

Accelerated repopulation of mouse tongue epithelium during fractionated irradiations or following single doses

International Nuclear Information System (INIS)

Doerr, W.; Kummermehr, J.

1990-01-01

Mouse tongue mucosa was established as an animal model to study repopulation after large single doses or during continuous irradiation. A top-up irradiation technique was used employing priming doses or fractionated treatment to the whole snout (300 kV X-rays) followed by local test doses (25 kV X-rays) to elicit denudation in a confined field of the inferior tongue surface. Clearcut quantal dose-response curves of ulcer incidence were obtained to all protocols; animal morbidity, i.e. body weight loss was minimal. Repopulation following priming doses of 10 and 13 Gy started with a delay of at least 3 days and then progressed rapidly to nearly restore original tissue tolerance by day 11. During continuous fractionation over 1 to 3 weeks with 5 fractions/week and doses per fraction of 2.5, 3 and 3.5 Gy, repopulation was small in week one but subsequently increased to fully compensate the weekly dose at all dose levels. Additional measurements of cell density during a 4 weeks course of 5 x 3 Gy or 5 x 4 Gy per week showed only moderate depletion to 67% of the control figures. The fact that rapid repopulation is achieved at relatively moderate damage levels should be taken into account when the timing of a treatment split is considered. (author). 18 refs.; 7 figs.; 1 tab

Protection of melanized Cryptococcus neoformans from lethal dose gamma irradiation involves changes in melanin's chemical structure and paramagnetism.

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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.

Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

DEFF Research Database (Denmark)

Bøtter-Jensen, L.; Solongo, S.; Murray, A.S.

2000-01-01

We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks acid unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient...... dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only...

Response of rat spinal cord to single and fractionated doses of accelerated heavy ions

International Nuclear Information System (INIS)

Leith, J.T.; McDonald, M.; Powers-Risius, P.; Bliven, S.F.; Howard, J.

1982-01-01

The thoraco-lumbar (T12-L1) region of the spinal cord of rats was exposed to either single or fractionated (four daily exposures) doses of X rays (230 kVp) or heavy ions. The heavy ions used were carbon and neon, and the relative biological effectiveness (RBE) of both the plateau ionization region and the midpeak region of 4-cm spread-out Bragg peaks of each heavy ion were investigated. For single doses of carbon and neon ions in the plateau ionization region, RBE values of 1.45 +/- 0.25 (propagated 95% confidence limits) and 1.46 +/- 0.33, respectively, were obtained. In the spread peak regions for carbon and neon ions, the RBE values were 1.48 +/- 0.18 and 1.86 +/- 0.42, respectively. These values were obtained using the dose needed to produce 50% paralysis in a group of irradiated rats as the isoeffect comparison dose (ED 50 dose). Similarly, in groups of rats receiving four daily exposures, the RBE values for carbon and neon ions in the plateau ionization region were 1.31 +/- 0.27 and 1.80 +/- 0.24, respectively. In the spread peak regions of ionization for carbon and neon ions, the RBE values were 1.95 +/- 0.19 and 2.18 +/- 0.23, respectively. Similar values for RBE were obtained using changes in the activity of enzymes in spinal cord tissue (cyclic nucleotide phosphohydrolase and γ-glutamyl transpeptidase). Also, it was estimated that, for X irradiation, the fractional amount of dose repaired (at the ED 50 dose) was 0.64 +/- 0.10 (95% confidence limits). For carbon and neon ions in the plateau ionization region, the values for the fractional amount of dose repaired were 0.70 +/- 0.27 and 0.48 +/- 0.20, and for carbon and neon ions in the spread peak region of ionization, the fractional repair values were 0.40 +/- 0.10 and 0.52 +/- 0.17. Spinal cord tissue therefore shows a high capacity for subeffective damage repair

Pharmacokinetics of pregabalin controlled-release in healthy volunteers: effect of food in five single-dose, randomized, clinical pharmacology studies.

Science.gov (United States)

Chew, Marci L; Plotka, Anna; Alvey, Christine W; Pitman, Verne W; Alebic-Kolbah, Tanja; Scavone, Joseph M; Bockbrader, Howard N

2014-09-01

The pharmacokinetic properties of the immediate-release (IR) and the recently developed controlled-release (CR) formulation of pregabalin are dose proportional. Pregabalin IR can be taken with or without food. This analysis characterizes the effect of food on pregabalin CR. The objectives of this analysis were: (1) to evaluate the effect of administration time and fat or caloric content of an accompanying meal on the pharmacokinetic properties of a single dose of pregabalin CR (330 mg) relative to a single dose of pregabalin IR (300 mg); (2) to evaluate the pharmacokinetic properties of a single dose of pregabalin CR administered fasted relative to a single dose of pregabalin CR administered immediately after food; and (3) to determine the safety and tolerability of single-dose administration of pregabalin CR and IR with and without food. The effect of food on the pharmacokinetic properties of pregabalin CR was determined in five phase I, open-label, single-dose, crossover studies (24-28 participants/study). Caloric and fat content of meals were varied and treatments were administered in the morning, at midday, or in the evening. Blood samples were collected up to 48 h post-dose. Pharmacokinetic parameters were estimated from plasma concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout all studies. One hundred and twenty-eight healthy participants (19-54 years of age) received pregabalin. Peak plasma concentrations (C max) were lower for CR than the respective pregabalin IR doses, and time to C max occurred later. When pregabalin CR was administered with food at midday or in the evening, total exposures [area under the plasma concentration-time curve from time zero extrapolated to infinite time (AUC∞)] were equivalent for pregabalin CR and IR formulations regardless of fat or caloric content. When pregabalin CR was administered with an 800-1,000 calorie medium-fat breakfast, AUC∞ was equivalent for

Sub-lethal irradiation of human colorectal tumor cells imparts enhanced and sustained susceptibility to multiple death receptor signaling pathways.

Directory of Open Access Journals (Sweden)

Victoria Ifeadi

Full Text Available BACKGROUND: Death receptors (DR of the TNF family function as anti-tumor immune effector molecules. Tumor cells, however, often exhibit DR-signaling resistance. Previous studies indicate that radiation can modify gene expression within tumor cells and increase tumor cell sensitivity to immune attack. The aim of this study is to investigate the synergistic effect of sub-lethal doses of ionizing radiation in sensitizing colorectal carcinoma cells to death receptor-mediated apoptosis. METHODOLOGY/PRINCIPAL FINDINGS: The ability of radiation to modulate the expression of multiple death receptors (Fas/CD95, TRAILR1/DR4, TRAILR2/DR5, TNF-R1 and LTβR was examined in colorectal tumor cells. The functional significance of sub-lethal doses of radiation in enhancing tumor cell susceptibility to DR-induced apoptosis was determined by in vitro functional sensitivity assays. The longevity of these changes and the underlying molecular mechanism of irradiation in sensitizing diverse colorectal carcinoma cells to death receptor-mediated apoptosis were also examined. We found that radiation increased surface expression of Fas, DR4 and DR5 but not LTβR or TNF-R1 in these cells. Increased expression of DRs was observed 2 days post-irradiation and remained elevated 7-days post irradiation. Sub-lethal tumor cell irradiation alone exhibited minimal cell death, but effectively sensitized three of three colorectal carcinoma cells to both TRAIL and Fas-induced apoptosis, but not LTβR-induced death. Furthermore, radiation-enhanced Fas and TRAIL-induced cell death lasted as long as 5-days post-irradiation. Specific analysis of intracellular sensitizers to apoptosis indicated that while radiation did reduce Bcl-X(L and c-FLIP protein expression, this reduction did not correlate with the radiation-enhanced sensitivity to Fas and/or TRAIL mediated apoptosis among the three cell types. CONCLUSIONS/SIGNIFICANCE: Irradiation of tumor cells can overcome Fas and TRAIL

Mining of lethal recessive genetic variation in Danish cattle

DEFF Research Database (Denmark)

Das, Ashutosh

2015-01-01

in fertility. The primary objective of this PhD projekt was to identify recessive lethal gentic variants in the main Danish dairy cattle breed. Holstein-Friesian utilzing next generation sequencing (NGS) data. This study shows a potential for the use of the NGS-based reverse genetic approach in identifying...... lethal or semi-lethal recessive gentic variation...

Single dose oral flurbiprofen for acute postoperative pain in adults

Science.gov (United States)

Sultan, Asquad; McQuay, Henry J; Moore, R Andrew; Derry, Sheena

2014-01-01

Background Flurbiprofen is a non-selective non-steroidal anti-inflammatory drug (NSAID), related to ibuprofen and naproxen, used to treat acute and chronic painful conditions. There is no systematic review of its use in acute postoperative pain. Objectives To assess efficacy, duration of action, and associated adverse events of single dose oral flurbiprofen in acute postoperative pain in adults. Search methods We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to January 2009. Selection criteria Randomised, double blind, placebo-controlled trials of single dose orally administered flurbiprofen in adults with moderate to severe acute postoperative pain. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk (RR) and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected. Main results Eleven studies compared flurbiprofen (699 participants) with placebo (362 participants) in studies lasting 6 to 12 hours. Studies were of adequate reporting quality, and most participants had pain following dental extractions. The dose of flurbiprofen used was 25 mg to 100 mg, with most information for 50 mg and 100 mg. The NNT for at least 50% pain relief over 4 to 6 hours for flurbiprofen 50 mg compared with placebo (692 participants) was 2.7 (2.3 to 3.3) and for 100 mg (416 participants) it was 2.5 (2.0 to 3.1). With flurbiprofen 50 mg and 100 mg 65% to 70% of participants experienced at least 50% pain relief, compared with 25% to 30% with placebo. Rescue medication was used by 25

Monte Carlo uncertainty analysis of dose estimates in radiochromic film dosimetry with single-channel and multichannel algorithms.

Science.gov (United States)

Vera-Sánchez, Juan Antonio; Ruiz-Morales, Carmen; González-López, Antonio

2018-03-01

To provide a multi-stage model to calculate uncertainty in radiochromic film dosimetry with Monte-Carlo techniques. This new approach is applied to single-channel and multichannel algorithms. Two lots of Gafchromic EBT3 are exposed in two different Varian linacs. They are read with an EPSON V800 flatbed scanner. The Monte-Carlo techniques in uncertainty analysis provide a numerical representation of the probability density functions of the output magnitudes. From this numerical representation, traditional parameters of uncertainty analysis as the standard deviations and bias are calculated. Moreover, these numerical representations are used to investigate the shape of the probability density functions of the output magnitudes. Also, another calibration film is read in four EPSON scanners (two V800 and two 10000XL) and the uncertainty analysis is carried out with the four images. The dose estimates of single-channel and multichannel algorithms show a Gaussian behavior and low bias. The multichannel algorithms lead to less uncertainty in the final dose estimates when the EPSON V800 is employed as reading device. In the case of the EPSON 10000XL, the single-channel algorithms provide less uncertainty in the dose estimates for doses higher than four Gy. A multi-stage model has been presented. With the aid of this model and the use of the Monte-Carlo techniques, the uncertainty of dose estimates for single-channel and multichannel algorithms are estimated. The application of the model together with Monte-Carlo techniques leads to a complete characterization of the uncertainties in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Enhanced lethal effect of combined ACNU with x-ray on cultured HeLaS3 cells

International Nuclear Information System (INIS)

Kanazawa, Haruyuki; Miyamoto, Tadaaki

1983-01-01

The combined effects of ACNU and X-irradiation on cultured HeLaS 3 cells were investigated. Pretreatment with either ACNU or X-ray induced a substantial reduction in shoulder width the D 0 value of the dose-response curve for the other agent, given later was unchanged. ACNU did not inhibit the recovery of sublethal damage (SLD) induced by X-ray when this treatment preceded the spilit-dose experiment. Our results indicate that some cell damage induced by each agent is transmissible to the progeny of the surviving cells and that the interaction of ACNU and X-irradiation was lethal to the cells. (author)

Protective Monotherapy Against Lethal Ebola Virus Infection by a Potently Neutralizing Antibody

Science.gov (United States)

2016-07-11

were 49   identified and enrolled in VRC200 clinical trial #NCT00067054 after giving signed 50   informed consent . Peripheral blood mononuclear...illness 56   when administered one day after lethal challenge. Treatment with a single human 57   mAb suggests a simplified therapeutic strategy for...efforts to simplify the ZMapp regimen to contain fewer mAbs have not been successful in 75   the macaque EVD model (7). We sought to isolate

Potentiation of radiation lethality by Topotecan, a Topoisomerase I inhibitor

International Nuclear Information System (INIS)

Lamond, J.P.; Kinsella, T.J.; Boothman, D.A.

1995-01-01

Purpose/Objective: Topotecan is a water soluble Topoisomerase I (Topo I) inhibitor that has demonstrated antineoplastic activity in phase I/II trials of solid tumors (such as non-small cell lung, small cell lung, ovarian, esophageal and head and neck primaries) and leukemias. We sought to determine (1) if Topotecan potentiated the lethal effects of ionizing radiation, and (2) the characteristics of the synergistic effect. Materials and Methods: Human radioresistant melanoma (U1-Mel) and glioma (D54) cells were grown in Dulbecco's modified Eagle's medium (DME) with 10% fetal calf serum (FCS) until confluence-arrest. Cells were x-irradiated (0-700 cGy) and exposed to various Topotecan concentrations (2-100μM), either before (for 4 hours), during, or after (for 4 hours) irradiation. Appropriate controls were also performed. Survival was determined via colony forming assays. Survival curves were normalized to correct for drug cytotoxicities and variations in initial viable cells plated. In another set of experiments, U1-Mel cells were exposed to 10 μM Topotecan either before, during or after 400 cGy, as described above. A modification of the SDS and KCl assay was used to quantify Topo I-DNA complexes via glass fiber filter binding. All experiments were performed at least 7 times in duplicate. Results: Potentiation of radiation lethality was seen in the U1-Mel and D54 cell lines. The synergistic effects were (1) dependent on drug concentration, with lethality enhancement and minimal drug lethality alone in the 2-10 μM range (2) dependent on timing, with synergy present only when the drug was present at the time of, or shortly after irradiation, and (3) irreversible, with inhibition of potential lethal damage repair (PLDR). The dose enhancement ratios (DER) for 4 μM Topotecan in the U1-Mel cells was 1.7 - 2.4, depending on the survival endpoints that were used. The DER for 2 μM Topotecan in D54 cells was 3.0 - 4.0. The U1-Mel cells that were exposed to Topotecan

The clinic and pathologic picture in the lethal dose irradiated ewes

International Nuclear Information System (INIS)

Halagan, J.; Stanikova, A.; Maracek, I.

2004-01-01

The history of clinical symptoms as well as pathologic histological and morphological changes after long/lasting gamma irradiation were estimated in seven clinical healthy ewes. The animals were irradiated continually seven days with totally 6.7 Gy per ewe. Clinically recognizable symptoms of the radiation sickness were observed commencing the 4 th after last dose of irradiation. Sharp increase of the body temperature, heart and respiratory frequency rate as well as apathy, anorexia, arrhythmia, dyspnoe, diarrhea, dehydration, polyuria were prevalent in clinical founding . All of the animals were death in course of seven days after last irradiated dose. The gastrointestinal radiation syndrome was typical evidence of gastrointestinal tract and the general hemorrhagic enhancing of the gamma irradiation damage effects was confirmed. (authors)

Evaluation of Sphingolipids in Wistar Rats Treated to Prolonged and Single Oral Doses of Fumonisin B1

Science.gov (United States)

Direito, Glória M.; Almeida, Adriana P.; Aquino, Simone; dos Reis, Tatiana Alves; Pozzi, Claudia Rodrigues; Corrêa, Benedito

2009-01-01

The objective of the present study was to evaluate sphingolipid levels (sphingosine-So and sphinganine-Sa) and to compare the Sa/So ratio in liver, serum and urine of Wistar rats after prolonged administration (21 days) of fumonisin B1 (FB1). In parallel, the kinetics of sphingolipid elimination in urine was studied in animals receiving a single dose of FB1. Prolonged exposure to FB1 caused an increase in Sa levels in urine, serum and liver. The most marked effect on sphingolipid biosynthesis was observed in animals treated with the highest dose of FB1. Animals receiving a single dose of FB1 presented variations in Sa and So levels and in the Sa/So ratio. PMID:19333435

A simulation study on the dose distribution for a single beam of the gamma knife

International Nuclear Information System (INIS)

Chen, Chin-cheng; Jiang, Shiang-Huei; Lee, Chung-chi; Shiau, Cheng-Ying

2000-01-01

The purpose of this study is to evaluate the impact of the tissue heterogeneity on the dose distribution for a single beam of the gamma knife. The EGS4 Monte Carlo code was used to simulate both depth and radial profiles of the radiation dose in homogeneous and heterogeneous phantoms, respectively. The results are compared with the dose distribution calculated using the mathematical model of Gamma Plan, the treatment planning system of the gamma knife. The skull and sinus heterogeneity were simulated by a Teflon shell and an air shell, respectively. It was found that the tissue heterogeneity caused significant perturbation on the absolute depth dose at the focus as well as on the depth-dose distribution near the phantom surface and/or at the interface but little effect on the radial dose distribution. The effect of the beam aperture on the depth-dose distribution was also investigated in this study. (author)

Pathological changes of pesticide poisonings in birds (experimental mercury poisoning in ducks and fowls)

Energy Technology Data Exchange (ETDEWEB)

Tishkov, A I

1974-01-01

The mercury compounds granosan (ethylmercury chloride), agrozan, mercuran and mercurhexan were given to 80 ducks and 142 fowls in single, lethal doses or as repeated doses of one-tenth to one-eightieth of the lethal dose. Characteristic post mortem findings were: severe disorders of haematopoiesis; degenerative changes in the liver, kidneys and myocardium; inflammatory and necrotic processes in the digestive tract; non-reactive necrosis in the liver and kidneys.

An explanation for the multiplicative and the additive dose-effect relationship with the single-hit model

International Nuclear Information System (INIS)

Kottbauer, M.M.; Fleck, C.M.; Schoellnberger, H.

1997-01-01

For solid tumors and for leukemia the excess cancer rate after a single radiation dose D is different. The multiplicative model describes the excess solid tumor probability rate which is proportional to the background rate of cancer and dependent on dose D. The additive model describes the excess probability rate for leukaemia which is proportional to the dose D but unrelated to the spontaneous rate of cancer. A second great difference between the two models is the duration of the increased cancer probability rate. The multiplicative mode predicts that the additional cancer risk persist the whole lifetime after exposure and the additive model predicts excess risk over a period of time. With the Single-hit model (SHM) which is a multistage cancer model both dose-response relationships can be described. It will be shown that only small differences in the derivation will lead to the different relationships. We then analyze the incidence data of leukemia (1950-1987) and of all solid tumors (1958-1987) of the atomic bomb survivors. (author)

The influence of continuous γ-irradiation at decreasing dose-rate on the survival rote and induction of gene mutations in cultured Chinese hamster cells

International Nuclear Information System (INIS)

Feoktistova, T.P.; Elisova, E.V.; Stavrakova, N.M.

1991-01-01

Continuous γ-irradiation at decreasing dose-rate was shown to be less effective than acute exposure with regard to the lethal effect and frequency of mutations of resistance to 6-thioguanine in cultured Chinese hamster cells. The cell population subjected to continuons irradiation was d more radioresistant than the intact one. Lethal and genetic effects of continuous irradiation at decreasing dose-rate were mainly determined by the contribution of the radiation dose received during the first 24 h of exposure

Evidence for single-dose protection by the bivalent HPV vaccine-Review of the Costa Rica HPV vaccine trial and future research studies.

Science.gov (United States)

Kreimer, Aimée R; Herrero, Rolando; Sampson, Joshua N; Porras, Carolina; Lowy, Douglas R; Schiller, John T; Schiffman, Mark; Rodriguez, Ana Cecilia; Chanock, Stephen; Jimenez, Silvia; Schussler, John; Gail, Mitchell H; Safaeian, Mahboobeh; Kemp, Troy J; Cortes, Bernal; Pinto, Ligia A; Hildesheim, Allan; Gonzalez, Paula

2018-01-20

The Costa Rica Vaccine Trial (CVT), a phase III randomized clinical trial, provided the initial data that one dose of the HPV vaccine could provide durable protection against HPV infection. Although the study design was to administer all participants three doses of HPV or control vaccine, 20% of women did not receive the three-dose regimens, mostly due to involuntary reasons unrelated to vaccination. In 2011, we reported that a single dose of the bivalent HPV vaccine could be as efficacious as three doses of the vaccine using the endpoint of persistent HPV infection accumulated over the first four years of the trial; findings independently confirmed in the GSK-sponsored PATRICIA trial. Antibody levels after one dose, although lower than levels elicited by three doses, were 9-times higher than levels elicited by natural infection. Importantly, levels remained essentially constant over at least seven years, suggesting that the observed protection provided by a single dose might be durable. Much work has been done to assure these non-randomized findings are valid. Yet, the group of recipients who received one dose of the bivalent HPV vaccine in the CVT and PATRICIA trials was small and not randomly selected nor blinded to the number of doses received. The next phase of research is to conduct a formal randomized, controlled trial to evaluate the protection afforded by a single dose of HPV vaccine. Complementary studies are in progress to bridge our findings to other populations, and to further document the long-term durability of antibody response following a single dose. Published by Elsevier Ltd.

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.

The effect of single and double doses of gamma radiation on pre-rigor mortis filleted saithe

International Nuclear Information System (INIS)

Underdahl, B.; Lunde, G.

1973-01-01

Saithe, caught off the western coast of Norway, were filleted immediately after killing, packed in plastic bags and irradiated using a cobalt-60 source at the Institutt for Atomenergi, Kjeller. The doses were 50, 100, 150, 50+50 and 50+100 krad. All samples were analysed for their total bacterial count, proteolytic activity, ammonia, total volatile acids, trimethylamine oxide, tri- and dimethylamine and formaldehyde. The organoleptic quality was evaluated by a panel of tasters. Double doses were more effective in reducing the total bacterial count than an equivalent single dose. A close relation was found between the bacterial count and the proteolytic activity. The trimethylamine oxide concentration was found to vary between 33 and 44 mg/100 g muscle, decreasing rapidly in non-irradiated fillets to 3 mg/100 g. In non-irradiated fillets trimethylamine oxide was mainly reduced to trimethylamine and in irradiated fillets to dimethylamine and formaldehyde. A split dose of 50+50 krad may have a favourable effect on the total bacterial number, but the analyses of proteolytic activity, the volatile acids and the trimethylamine indicate that a higher proportion of spoilage bacteria survive. The low proteolytic activity and the high content of DMA/FA prove that the split doses of 50+100 krad as compared with a single dose of 150 krad are particularly favourable in the case of saithe. (Auth.)

Vaginal bleeding following the use of a single dose of 1.5mg ...

African Journals Online (AJOL)

Introduction: Recent studies have shown that a single dose of 1.5 mg levonorgestrel is an effective and safe emergency contraceptive but detailed information on its menstrual side effects is lacking. This study assessed the vaginal bleeding patterns in healthy women who used the medication for emergency contraception.

Quantitative assessment of changes in the dermal fibroblast population of pig skin after single doses of X-rays

Energy Technology Data Exchange (ETDEWEB)

Hamlet, R.; Hopewell, J.W.

1988-10-01

Changes in the density of fibroblast nuclei in reticular dermis of pigs was studied from 6 to 104 weeks after a single dose of 15.4 Gy of X-rays. The largest decrease in fibroblasts occurred between 12 and 26 weeks after irradiation; after this there was only a slight fall in fibroblast number until 104 weeks when observations ceased. At 26 weeks and later times after irradiation reduction in the density of fibroblast nuclei in the reticular dermis was dose-dependent for single doses in the range 8.0-20.7 Gy. The dose-response curve had an initial shoulder, after which the fall in the fibroblast nuclear density was linearly related to dose. Data obtained between 26 weeks and 104 weeks after irradiation, could be fitted by the same dose-response curve. The fall in the counts of fibroblast nuclei was compared with earlier studies. The loss of fibroblasts occurred after an initial reduction in blood flow in the pig skin but was concomitant with general reduction in dermal thickness.

Can a single dose of human papillomavirus (HPV) vaccine prevent cervical cancer? Early findings from an Indian study.

Science.gov (United States)

Sankaranarayanan, Rengaswamy; Joshi, Smita; Muwonge, Richard; Esmy, Pulikottil Okkuru; Basu, Partha; Prabhu, Priya; Bhatla, Neerja; Nene, Bhagwan M; Shaw, Janmesh; Poli, Usha Rani Reddy; Verma, Yogesh; Zomawia, Eric; Pimple, Sharmila; Tommasino, Massimo; Pawlita, Michael; Gheit, Tarik; Waterboer, Tim; Sehr, Peter; Pillai, Madhavan Radhakrishna

2018-03-15

Human papillomavirus (HPV) vaccination is a major strategy for preventing cervical and other ano-genital cancers. Worldwide HPV vaccination introduction and coverage will be facilitated if a single dose of vaccine is as effective as two or three doses or demonstrates significant protective effect compared to 'no vaccination'. In a multi-centre cluster randomized trial of two vs three doses of quadrivalent HPV vaccination (Gardasil™) in India, suspension of the vaccination due to events unrelated to the study led to per protocol and partial vaccination of unmarried 10-18 year old girls leading to four study groups, two by design and two by default. They were followed up for the primary outcomes of immunogenicity in terms of L1 genotype-specific binding antibody titres, neutralising antibody titres, and antibody avidity for the vaccine-targeted HPV types and HPV infections. Analysis was per actual number of vaccine doses received. This study is registered with ISRCTN, number ISRCTN98283094; and with ClinicalTrials.gov, number NCT00923702. Of the 17,729 vaccinated girls, 4348 (25%) received three doses on days 1, 60, 180 or later, 4979 (28%) received two doses on days 1 and 180 or later, 3452 (19%) received two doses on days 1 and 60, and 4950 (28%) received one dose. One dose recipients demonstrated a robust and sustained immune response against HPV 16 and 18, albeit inferior to that of 3- or 2-doses and the antibody levels were stable over a 4 year period. The frequencies of cumulative incident and persistent HPV 16 and 18 infections up to 7 years of follow-up were similar and uniformly low in all the vaccinated study groups; the frequency of HPV 16 and 18 infections were significantly higher in unvaccinated age-matched control women than among vaccine recipients. The frequency of vaccine non-targeted HPV types was similar in the vaccinated groups but higher in the unvaccinated control women. Our results indicate that a single dose of quadrivalent HPV

Lethal effects of solar radiation in proficient and deficient bacteria in repair systems

International Nuclear Information System (INIS)

Sousa Neto, A. de.

1980-01-01

A study of the lethal action of solar radiation on strains of E.coli K12, proficient or deficient in repair systems, as well as the wild type strain gene products are involved in repair of damage induced by solar radiation. The inactivation of the various bacterial strains (normalized to a dose equivalent to radiation at a wavelength 254 nm) suggests that the more energetic wavelengths of the solar spectrum (290-320 nm) could be responsible for the primary damage that occurs in the DNA. The reduction in the shoulder of the survival curve in wild type strains in indicative of induction of sub-lethal damage in this region of the curve. Analysing solar inactivation curves of the bacterial strains (normalised by spore dosimetry) together with those of the same strains irradiated with UV at 254 nm, it was evident that 254 nm is not the ideal wavelength for comparison. This analysis also indicated that in addition to damage to DNA, other factors are involved in the solar radiation inactivation of wild type strains. (author)

Forecasting of the lethality in cases of nonuniform accidental irradiation (experimental studies at external gamma irradiation of rats)

International Nuclear Information System (INIS)

Ingilizova, K.

1983-01-01

A model is suggested that enables the prediction of death probability for the body (L) within the whole lethality dose range (DL 0 -DL 100 ), on the basis of predetermined physical characteristics: in cases of uneven external wholebody irradiation. Some biological effects of 4 variants of uneven irradiation have been studied, i.e. ventro-dorsal (V-D), dorso-ventral (D-V), cranio-caudal (Cr-Ca) and caudo-cranial (Ca-Cr). The following basic conclusions have been drawn: 1. The study of the biological effects of uneven irradiation, when estimated by the lethality factor, points out the lower efficiency of the former, if compared to even irradiation. 2. The even irradiation lethality in the conducted experiments, according to the ALE data and the postradiation mortality dynamics, is determined basically by the damage of the bloodforming tissue and the animals die of bone marrow syndrome. 3. The uneven irradiation, estimated by the total weight factor, is of lower efficiency than the even one. 4. The radiation-induced hypoplasia of the studied organs is exponential in character. 5. An original model for predicting radiation mortality in cases of uneven irradiation has been constructed. The model gives the possibility of relating the alterations in the index of biological efficiency reduction to the wholebody irradiation factor, as well as to the two systems with highest radiosensitivity: red bone marrow and the small intestine. The model helps determining the numerical value of death probability, depending on the average body irradiation doses and the integral unevenness factors for RBM. (author)

Comparison of scatter doses from a multislice and a single slice CT scanner

International Nuclear Information System (INIS)

Burrage, J. W.; Causer, D. A.

2006-01-01

During shielding calculations for a new multislice CT (MSCT) scanner it was found that the manufacturer's data indicated significantly higher external scatter doses than would be generated for a single slice CT (SSCT). Even allowing for increased beam width, the manufacturer's data indicated that the scatter dose per scan was higher by a factor of about 3 to 4. The magnitude of the discrepancy was contrary to expectations and also contrary to a statement by the UK ImPACT group, which indicated that when beam width is taken into account, the scatter doses should be similar. The matter was investigated by comparing scatter doses from an SSCT and an MSCT. Scatter measurements were performed at three points using a standard perspex CTDI phantom, and CT dose indices were also measured to compare scanner output. MSCT measurements were performed with a 40 mm wide beam, SSCT measurements with a 10 mm wide beam. A film badge survey was also performed after the installation of the MSCT scanner to assess the adequacy of lead shielding in the room. It was found that the scatter doses from the MSCT were lower than indicated by the manufacturer's data. MSCT scatter doses were approximately 4 times higher than those from the SSCT, consistent with expectations due to beam width differences. The CT dose indices were similar, and the film badge survey indicated that the existing shielding, which had been adequate for the SSCT, was also adequate for the MSCT

Single dose oral ketoprofen or dexketoprofen for acute postoperative pain in adults.

Science.gov (United States)

Gaskell, Helen; Derry, Sheena; Wiffen, Philip J; Moore, R Andrew

2017-05-25

This review is an update of "Single dose oral ketoprofen and dexketoprofen for acute postoperative pain in adults" last updated in Issue 4, 2009. Ketoprofen is a non-selective nonsteroidal anti-inflammatory drug (NSAID) used to treat acute and chronic painful conditions. Dexketoprofen is the (S)-enantiomer, which is believed to confer analgesia. Theoretically dexketoprofen is expected to provide equivalent analgesia to ketoprofen at half the dose, with a consequent reduction in gastrointestinal adverse events. This review is one of a series on oral analgesics for acute postoperative pain. Individual reviews have been brought together in two overviews to provide information about the relative efficacy and harm of the different interventions. To assess the efficacy and safety of single dose oral ketoprofen and oral dexketoprofen compared with placebo for acute postoperative pain, using methods that permit comparison with other analgesics evaluated in the same way, and criteria of efficacy recommended by an in-depth study at the individual patient level. For this update, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from 2009 to 28 March 2017. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries. Randomised, double-blind, placebo-controlled trials of single dose orally administered ketoprofen or dexketoprofen in adults with moderate to severe acute postoperative pain. Two review authors independently considered studies for inclusion in the review, examined issues of study quality and potential bias, and extracted data. For dichotomous outcomes, we calculated risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or harmful outcome (NNH) with 95% confidence intervals (CI) for ketoprofen and dexketoprofen, compared with placebo, where there were sufficient data. We collected information on the number of participants with at least 50

The effectiveness of small doses of ionizing radiations for the induction of cell reproductive death, chromosomal changes and malignant transformation

International Nuclear Information System (INIS)

Barendsen, G.W.

1976-01-01

For reproductive death of mammalian cells, accumulation of damage induced by two or more particles is frequently predominant at doses of X-rays or γ-rays in excess of 500 rad. For doses of less than 100 rad of X-rays, damage due to single particles generally provides the largest contribution to cell lethality, but the relative effectiveness depends strongly on the type of cell investigated and on the conditions of exposure and environment. In addition, a marked dependence on LET is observed. For LET values at which the relative contribution of accumulation of damage has become negligible, a significant influence of dose-modifying factors such as the presence of oxygen may still be evident. This implies that 'single particle damage' is not necessarily independent of modifying factors. A similar conclusion can be derived from data on some types of micro-organisms. For the induction of chromosome aberrations, published data show that the relative contributions of the two types of mechanisms mentioned, may depend on the type of aberration studied. For tumor induction the relative contributions of the two mechanisms cannot in general be derived from incidence versus dose relations because of the influence of promoting, permitting and inhibiting conditions and the influence of cell reproductive death

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.)

Attention benefits after a single dose of metadoxine extended release in adults with predominantly inattentive ADHD.

Science.gov (United States)

Manor, Iris; Rubin, Jonathan; Daniely, Yaron; Adler, Lenard A

2014-09-01

To assess the first-dose effectiveness and tolerability of metadoxine extended release (MDX) in adults with predominantly inattentive attention-deficit/hyperactivity disorder (ADHD-PI). In this double-blind, placebo-controlled, crossover study, adults with ADHD-PI were randomized 1:1:1 to receive a single dose of MDX 1400 mg, MDX 700 mg, and placebo (ClinicalTrials.gov identifier: NCT01685281). The primary efficacy end point was the mean change in the Test of Variables of Attention (TOVA) ADHD score from baseline to 3 to 5 hours after drug administration. Secondary assessments included TOVA subscores, TOVA response rates (defined as an increase of 0.8 points in the TOVA ADHD score), and the Cambridge Neuropsychological Automated Test Battery. Safety assessments included adverse events and vital signs. The intention-to-treat population included 36 patients (52.8% men; mean age, 32 years). The efficacy of MDX 1400 mg was demonstrated by a statistically significant difference in the mean (± SD) change in the TOVA ADHD score at baseline to 3 to 5 hours after drug administration compared with placebo (2.0 [4.2]; P = 0.009). The TOVA response time variability subscore was significantly different between MDX 1400 mg and placebo (mean difference, 7.9 [19.2] points; P = 0.022). Significantly more adults responded to single-dose MDX 1400 mg versus placebo (97.1% vs 71.4%, P = 0.006). There were no statistically significant differences between MDX 700 mg and placebo on any measures. Exploratory analyses of the Cambridge Neuropsychological Automated Test Battery did not yield significant findings. Fatigue and headache were the 2 most frequently reported adverse events. There were no clinically significant abnormalities in laboratory values, vital signs measurements, Columbia-Suicide Severity Rating Scale scores, or electrocardiographic parameters. Single-dose MDX 1400 mg significantly improved sustained and selective attention in adults with ADHD-PI as measured by the TOVA

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

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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

Venomics, lethality and neutralization of Naja kaouthia (monocled cobra) venoms from three different geographical regions of Southeast Asia.

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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

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

Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

Energy Technology Data Exchange (ETDEWEB)

Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K

2000-07-01

A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (autho000.

Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

International Nuclear Information System (INIS)

Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K.

2000-01-01

A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (author)

Quantitative determination of the contribution of indirect and direct radiation action to the production of lethal lesions in mammalian cells

International Nuclear Information System (INIS)

Pohlit, W.; Drenkard, S.

1985-01-01

For quantitative models of radiation action in living cells it is necessary to know what fraction of the absorbed dose affects the target molecule by direct radiation action and what fraction by indirect radiation action. Mammalian cells were irradiated in suspension, saturated with N 2 O or CO 2 . With these gases the production of OH-radicals is changed by a factor of two in aqueous solutions and a corresponding change in cell survival would be expected, if only indirect radiation action is involved in the production of lethal lesions in the living cell. No difference could be detected, however, and it is concluded that indirect radiation action does not contribute to radiation lethality in mammalian cells. (author)

Single dose oral ibuprofen plus paracetamol (acetaminophen) for acute postoperative pain.

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Derry, Christopher J; Derry, Sheena; Moore, R Andrew

2013-06-24

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. Some combinations of ibuprofen and paracetamol are available for use without prescription in some acute pain situations. To assess the efficacy and adverse effects of single dose oral ibuprofen plus paracetamol for acute postoperative pain using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 4 of 12, 2013), MEDLINE (1950 to May 21st 2013), EMBASE (1974 to May 21st 2013), the Oxford Pain Database, ClinicalTrials.gov, and reference lists of articles. Randomised, double-blind clinical trials of single dose, oral ibuprofen plus paracetamol compared with placebo or the same dose of ibuprofen alone for acute postoperative pain in adults. Two review authors independently considered trials for inclusion in the review, assessed quality, and extracted data. We used validated equations to calculate the area under the pain relief versus time curve and derive the proportion of participants with at least 50% of maximum pain relief over six hours. We calculated relative risk (RR) and number needed to treat to benefit (NNT) for ibuprofen plus paracetamol, ibuprofen alone, or placebo. We used information on use of rescue medication to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. We also collected information on adverse events. Searches identified three studies involving 1647 participants. Each of them examined several dose combinations. Included studies provided data from 508 participants for the comparison of ibuprofen 200 mg + paracetamol 500 mg with placebo, 543

Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

Science.gov (United States)

Huttner, Angela; Agnandji, Selidji Todagbe; Combescure, Christophe; Fernandes, José F; Bache, Emmanuel Bache; Kabwende, Lumeka; Ndungu, Francis Maina; Brosnahan, Jessica; Monath, Thomas P; Lemaître, Barbara; Grillet, Stéphane; Botto, Miriam; Engler, Olivier; Portmann, Jasmine; Siegrist, Denise; Bejon, Philip; Silvera, Peter; Kremsner, Peter; Siegrist, Claire-Anne

2018-04-04

The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose

Poly(ADP-ribose) metabolism in X-irradiated Chinese hamster cells: its relation to repair of potentially lethal damage

International Nuclear Information System (INIS)

Ben-Hur, E.; Elkind, M.M.

1984-01-01

Nicotinamide-adenine dinucleotide (NAD + ) is the substrate used by cells in poly(ADP-ribose) synthesis. X-irradiation of log-phase Chinese hamster cells caused a rapid decrease in NAD + levels which was linearly dependent on radiation dose. The activity of ADP-ribosyl transferase (ADPRT) also increased linearly with radiation dose. The decrease of NAD + was slower, and the increase in ADPRT activity was less pronounced, in a radiation sensitive line, V79-AL162/S-10. An inhibitor of ADPRT, m-aminobenzamide, largely prevented the depletion of cellular NAD + and reduced the rate at which ADPRT activity disappeared during post-irradiation incubation. Post-irradiation treatment with hypertonic buffer or with medium containing D 2 O-which inhibit repair of radiation-induced potentially lethal damage-enhanced the depletion of NAD + and prevented the reduction in ADPRT activity following irradiation. The characteristics of the effects of treatment with hypertonic buffer on NAD + metabolism were qualitatively similar to the effects that such treatment has on radiation-induced cell killing. These results suggest that poly(ADP-ribose) synthesis after irradiation plays a role in the repair of potentially lethal damage. (author)

Protective Effect of Phillyrin on Lethal LPS-Induced Neutrophil Inflammation in Zebrafish

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Liling Yang

2017-10-01

Full Text Available Background/Aims: Forsythia suspensa Vahl. (Oleaceae fruits are widely used in traditional Chinese medicine to treat pneumonia, typhoid, dysentery, ulcers and oedema. Antibacterial and anti-inflammatory activities have been reported for phillyrin (PHN, the main ingredient in Forsythia suspensa Vahl fruits, in vitro. However, the underlying mechanisms in vivo remain poorly defined. In this study, we discovered that PHN exerted potent anti-inflammatory effects in lethal LPS-induced neutrophil inflammation by suppressing the MyD88-dependent signalling pathway in zebrafish. Methods: LPS-yolk microinjection was used to induce a lethal LPS-infected zebrafish model. The effect of PHN on the survival of zebrafish challenged with lethal LPS was evaluated using survival analysis. The effect of PHN on neutrophil inflammation grading in vivo was assessed by tracking neutrophils with a transgenic line. The effects of PHN on neutrophil production and migration were analysed by SB+ cell counts during consecutive hours after modelling. Additionally, key cytokines and members of the MyD88 signalling pathway that are involved in inflammatory response were detected using quantitative RT-PCR. To assess gene expression changes during consecutive hours after modelling, the IL-1β, IL-6, TNF-α, MyD88, TRIF, ERK1/2, JNK, IκBa and NF-κB expression levels were measured. Results: PHN could protect zebrafish against a lethal LPS challenge in a dose-dependent manner, as indicated by decreased neutrophil infltration, reduced tissue necrosis and increased survival rates. Up-regulated IL-1β, IL-6 and TNF-α expression also showed the same tendencies of depression by PHN. Critically, PHN significantly inhibited the LPS-induced activation of MyD88, IκBa, and NF-κB but did not affect the expression of ERK1/2 MAPKs or JNK MAPKs in LPS-stimulated zebrafish. Additionally, PHN regulated the MyD88/IκBα/NF-κB signalling pathway by controlling IκBα, IL-1β, IL-6, and TNF

Single-dose Toxicity of ShinYangHur Herbal Acupuncture

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Eunhye Cha

2015-06-01

Full Text Available Objectives: This study was carried out to analyze the single-dose toxicity of ShinYangHur (SYH herbal acupuncture injected into the muscles of Sprague-Dawley (SD rats. Methods: The SYH herbal acupuncture was made in a clean room at the Korean Pharmacopuncture Institute (KPI, Korea-Good Manufacturing Practice, K-GMP. After the mixing process with sterile distilled water, the pH was controlled to between 7.0 and 7.5. Then, NaCl was added to make a 0.9% isotonic solution by using sterilized equipment. All experiments were conducted at Biotoxtech, an institution authorized to perform non clinical studies under the regulations of Good Laboratory Practice (GLP. SD rats were chosen for the pilot study. Doses of SYH herbal acupuncture, 0.25, 0.5, and 1.0 mL, were administered to the experimental groups, and a dose of normal saline solution, 1.0 mL, was administered to the control group. This study was conducted under the approval of the Institutional Animal Ethics Committee. Results: No deaths or abnormalities occurred in any of the four groups. No significant changes in weight, hematological parameters or clinical chemistry between the control group and the experimental groups were observed. To check for abnormalities in organs and tissues, we used microscopy was used to examine representative histological sections of each specified organ; the results showed no significant differences in any of the organs or tissues. Conclusion: The above outcomes suggest that treatment with SYH herbal acupuncture is relatively safe. Further studies on this subject are needed to yield more concrete evidence.

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

Science.gov (United States)

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

2006-06-01

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

Pharmacokinetics of colistin methanesulfonate (CMS) in healthy Chinese subjects after single and multiple intravenous doses.

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Zhao, Miao; Wu, Xiao-Jie; Fan, Ya-Xin; Zhang, Ying-Yuan; Guo, Bei-Ning; Yu, Ji-Cheng; Cao, Guo-Ying; Chen, Yuan-Cheng; Wu, Ju-Fang; Shi, Yao-Guo; Li, Jian; Zhang, Jing

2018-05-01

The high prevalence of extensively drug-resistant Gram-negative pathogens has forced clinicians to use colistin as a last-line therapy. Knowledge on the pharmacokinetics of colistin methanesulfonate (CMS), an inactive prodrug, and colistin has increased substantially; however, the pharmacokinetics in the Chinese population is still unknown due to lack of a CMS product in China. This study aimed to evaluate the pharmacokinetics of a new CMS product developed in China in order to optimise dosing regimens. A total of 24 healthy subjects (12 female, 12 male) were enrolled in single- and multiple-dose pharmacokinetic (PK) studies. Concentrations of CMS and formed colistin in plasma and urine were measured, and PK analysis was conducted using a non-compartmental approach. Following a single CMS dose [2.36 mg colistin base activity (CBA) per kg, 1 h infusion], peak concentrations (C max ) of CMS and formed colistin were 18.0 mg/L and 0.661 mg/L, respectively. The estimated half-life (t 1/2 ) of CMS and colistin were 1.38 h and 4.49 h, respectively. Approximately 62.5% of the CMS dose was excreted via urine within 24 h after dosing, whilst only 1.28% was present in the form of colistin. Following multiple CMS doses, colistin reached steady-state within 24 h; there was no accumulation of CMS, but colistin accumulated slightly (R AUC  = 1.33). This study provides the first PK data in the Chinese population and is essential for designing CMS dosing regimens for use in Chinese hospitals. The urinary PK data strongly support the use of intravenous CMS for serious urinary tract infections. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Evaluation of preclinical single and multiple dose toxicity and efficacy of 213 Bi-labeled plasminogen activator inhibitor 2 for breast and prostate cancer

International Nuclear Information System (INIS)

Rizvi, S.; Li, Y.; Allen, B.; Littlejohn, T.; Ranson, M.; Links, M.; Irving, D.; Andrews, J.

2003-01-01

The aim of the study was to evaluate the single and multiple dose toxicity (maximum tolerated dose or MTD) regimes for 213 Bi-labeled PAI2. Dose range of 2-8 mCi/kg was used for the single dose toxicity studies. It was found that end point (20% weight loss and/or distressed behaviour) was not reached for the highest dose either with single or multiple dose injections. For multiple dose toxicity studies, the dose levels ranged between 0.4 - 2 mCi/kg, and were administered daily for 5 days. The highest level tested (2mCi/kg/day x 5) was the maximum tolerated dose as 3/6 mice succumbed to the endpoints. However, histological examination of major organs showed no adverse morphological changes. From these toxicity studies, we concluded that either a dose of 1.6mCi/kg of 213 Bi-PAI2 per day for 5 days or a single injection of 8 mCi/kg can be administered without reaching the endpoints. These dose levels were used for efficacy trials. The efficacy studies were conducted to examine if the 1.6mCi/kgday x 5 multiple dose schedule (sub-maximum tolerated dose) showed efficacy against established and early stage human breast and prostate tumours in mice. Statistical analyses of the data indicate a significant tumour growth rate delay and increased time to reach tumour size endpoint for alpha-PAI2 treatment compared to control tumours, in both pre-tumour stage and established tumour models

Recombinant Parainfluenza Virus 5 Expressing Hemagglutinin of Influenza A Virus H5N1 Protected Mice against Lethal Highly Pathogenic Avian Influenza Virus H5N1 Challenge

Science.gov (United States)

Li, Zhuo; Mooney, Alaina J.; Gabbard, Jon D.; Gao, Xiudan; Xu, Pei; Place, Ryan J.; Hogan, Robert J.; Tompkins, S. Mark

2013-01-01

A safe and effective vaccine is the best way to prevent large-scale highly pathogenic avian influenza virus (HPAI) H5N1 outbreaks in the human population. The current FDA-approved H5N1 vaccine has serious limitations. A more efficacious H5N1 vaccine is urgently needed. Parainfluenza virus 5 (PIV5), a paramyxovirus, is not known to cause any illness in humans. PIV5 is an attractive vaccine vector. In our studies, a single dose of a live recombinant PIV5 expressing a hemagglutinin (HA) gene of H5N1 (rPIV5-H5) from the H5N1 subtype provided sterilizing immunity against lethal doses of HPAI H5N1 infection in mice. Furthermore, we have examined the effect of insertion of H5N1 HA at different locations within the PIV5 genome on the efficacy of a PIV5-based vaccine. Interestingly, insertion of H5N1 HA between the leader sequence, the de facto promoter of PIV5, and the first viral gene, nucleoprotein (NP), did not lead to a viable virus. Insertion of H5N1 HA between NP and the next gene, V/phosphorprotein (V/P), led to a virus that was defective in growth. We have found that insertion of H5N1 HA at the junction between the small hydrophobic (SH) gene and the hemagglutinin-neuraminidase (HN) gene gave the best immunity against HPAI H5N1 challenge: a dose as low as 1,000 PFU was sufficient to protect against lethal HPAI H5N1 challenge in mice. The work suggests that recombinant PIV5 expressing H5N1 HA has great potential as an HPAI H5N1 vaccine. PMID:23077314

Lethality of Rendang packaged in multilayer retortable pouch with sterilization process

Science.gov (United States)

Praharasti, A. S.; Kusumaningrum, A.; Frediansyah, A.; Nurhikmat, A.; Khasanah, Y.; Suprapedi

2017-01-01

Retort Pouch had become a choice to preserve foods nowadays, besides the used of the can. Both had their own advantages, and Retort Pouch became more popular for the reason of cheaper and easier to recycle. General Method usually used to estimate the lethality of commercial heat sterilization process. Lethality value wa s used for evaluating the efficacy of the thermal process. This study aimed to find whether different layers of pouch materials affect the lethality value and to find differences lethality in two types of multilayer retort pouch, PET/Aluminum Foil/Nylon/RCPP and PET/Nylon/Modified Aluminum/CPP. The result showed that the different layer arrangement was resulted different Sterilization Value (SV). PET/Nylon/Modified Aluminum/CPP had better heat penetration, implied by the higher value of lethality. PET/Nylon/Modified Aluminum/CPP had the lethality value of 6,24 minutes, whereas the lethality value of PET/Aluminum Foil/Nylon/RCPP was 3,54 minutes.

A luminescence imaging system for the routine measurement of single-grain OSL dose distributions

DEFF Research Database (Denmark)

Kook, Myung Ho; Lapp, Torben; Murray, Andrew

2015-01-01

the potential of an electron multiplying charge-coupled device (EMCCD), providing extremely low level light detection. We characterize the performance of the device by discussing reproducibility and evaluating uncertainties in OSL signals. Finally we derive a typical single grain natural dose distribution...

Remifentanil dose for laryngeal mask airway insertion with a single standard dose of propofol during emergency airway management in elderly patients.

Science.gov (United States)

Ryu, Junghee; Oh, Ah Young; Baek, Ji-Seok; Kim, Jin-Hee; Park, Sang-Heon; Noh, Jae-Mun

2014-04-01

This study determined the dose of remifentanil to use during insertion of a Classic™ laryngeal mask airway (LMA, The Laryngeal Mask Co., Nicosia, Cyprus) in elderly patients during emergency airway management when combined with a single dose of propofol. Patients aged 65-80 years were enrolled. Anesthesia was induced with propofol 1 mg/kg, and then a blinded dose of remifentanil was infused over 30 s after confirming the patient's loss of consciousness. The dose of remifentanil was determined using Dixon's up-and-down method, starting at 0.5 µg/kg (a step size of 0.1 µg/kg). Insertion of the LMA was attempted 60 s after loss of consciousness. In total, 23 patients were recruited and the mean age ± standard deviation was 72 ± 3 years. The effective dose for successful LMA insertion in 50% of the patients (ED50) was 0.20 ± 0.05 µg/kg. No patient needed more than 0.3 µg/kg. Remifentanil 0.20 ± 0.05 µg/kg with propofol 1 mg/kg resulted in excellent LMA insertion in 50% of elderly patients without significant hemodynamic changes during emergency airway management.

Spatial resolution of 2D ionization chamber arrays for IMRT dose verification: single-detector size and sampling step width

International Nuclear Information System (INIS)

Poppe, Bjoern; Djouguela, Armand; Blechschmidt, Arne; Willborn, Kay; Ruehmann, Antje; Harder, Dietrich

2007-01-01

The spatial resolution of 2D detector arrays equipped with ionization chambers or diodes, used for the dose verification of IMRT treatment plans, is limited by the size of the single detector and the centre-to-centre distance between the detectors. Optimization criteria with regard to these parameters have been developed by combining concepts of dosimetry and pattern analysis. The 2D-ARRAY Type 10024 (PTW-Freiburg, Germany), single-chamber cross section 5 x 5 mm 2 , centre-to-centre distance between chambers in each row and column 10 mm, served as an example. Additional frames of given dose distributions can be taken by shifting the whole array parallel or perpendicular to the MLC leaves by, e.g., 5 mm. The size of the single detector is characterized by its lateral response function, a trapezoid with 5 mm top width and 9 mm base width. Therefore, values measured with the 2D array are regarded as sample values from the convolution product of the accelerator generated dose distribution and this lateral response function. Consequently, the dose verification, e.g., by means of the gamma index, is performed by comparing the measured values of the 2D array with the values of the convolution product of the treatment planning system (TPS) calculated dose distribution and the single-detector lateral response function. Sufficiently small misalignments of the measured dose distributions in comparison with the calculated ones can be detected since the lateral response function is symmetric with respect to the centre of the chamber, and the change of dose gradients due to the convolution is sufficiently small. The sampling step width of the 2D array should provide a set of sample values representative of the sampled distribution, which is achieved if the highest spatial frequency contained in this function does not exceed the 'Nyquist frequency', one half of the sampling frequency. Since the convolution products of IMRT-typical dose distributions and the single

Effect of restricted access to food on metabolic changes in lethally X-irradiated rats. I

International Nuclear Information System (INIS)

Toropila, M.; Ahlers, I.; Ahlersova, E.; Praslicka, M.

1982-01-01

Differences in the reaction of glucose in blood and in that of glycogen in liver in animals with free access to food and in those with restricted food intake to lethal irradiation by X-rays were studied. SPF bred male rats of the Wistar strain were fed by common laboratory diet and by tap water ad libitum (AL group) or food was accessible to them (in unlimited amounts) only in the period between 09.00 a. m. and 11.00 a. m. (meal-fed group, MF), all under standard laboratory conditions. After more than three weeks of adaptation to the nutrition patterns and 22 h after the last food intake, animals of both groups were irradiated with a single whole-body 14.35 Gy dose of X-rays and/or sham irradiated, respectively. Glucose concentration in blood was increased in both groups during the experiment; terminal hyperglycaemia was more expressed in the MF group. Due to the high initial glycogen concentration in the liver of MF irradiated animals the accumulation of glycogen was substantially lower and started later than in irradiated AL animals. (author)

Postirradiation expression of lethal mutations in an immortalized human keratinocyte cell line

International Nuclear Information System (INIS)

O'Reilly, S.; Mothersill, C.; Seymour, C.B.

1994-01-01

The quantification of the extent of delayed cell death and the rate and pattern of its occurrence in relation to the cell division cycle is important in radiotherapy and also in radiation transformation studies related to protection and dose limits. Here the numbers of lethal mutations occurring over 45 population doublings (clonal expansion to about 10 13 cells per cell originally surviving irradiation) was measured in an HPV 16 immortalized human keratinocyte cell lines used for transformation studies. The results showed that when postirradiation (dose range 1-6 Gy) growth curves were constructed, the difference in slopes could be accounted for entirely by correcting for the non-clonogenic fraction in the cell count, excluding a longer cell generation time as an explanation. When the cell loss was examined over the entire growth period of 6 weeks (about 45 doublings of the cell population), it was found to be dose dependent for the first two passages, but then to become more independent of dose. The results allow a time/cell generation dependent factor to be derived for the cell line and used in survival curve equations where effects of radiation are being measured at times distant from the original exposure. (author)

Fasting protects mice from lethal DNA damage by promoting small intestinal epithelial stem cell survival.

Science.gov (United States)

Tinkum, Kelsey L; Stemler, Kristina M; White, Lynn S; Loza, Andrew J; Jeter-Jones, Sabrina; Michalski, Basia M; Kuzmicki, Catherine; Pless, Robert; Stappenbeck, Thaddeus S; Piwnica-Worms, David; Piwnica-Worms, Helen

2015-12-22

Short-term fasting protects mice from lethal doses of chemotherapy through undetermined mechanisms. Herein, we demonstrate that fasting preserves small intestinal (SI) architecture by maintaining SI stem cell viability and SI barrier function following exposure to high-dose etoposide. Nearly all SI stem cells were lost in fed mice, whereas fasting promoted sufficient SI stem cell survival to preserve SI integrity after etoposide treatment. Lineage tracing demonstrated that multiple SI stem cell populations, marked by Lgr5, Bmi1, or HopX expression, contributed to fasting-induced survival. DNA repair and DNA damage response genes were elevated in SI stem/progenitor cells of fasted etoposide-treated mice, which importantly correlated with faster resolution of DNA double-strand breaks and less apoptosis. Thus, fasting preserved SI stem cell viability as well as SI architecture and barrier function suggesting that fasting may reduce host toxicity in patients undergoing dose intensive chemotherapy.

Single-dose and steady-state pharmacokinetics of tenofovir disoproxil fumarate in human immunodeficiency virus-infected children.

Science.gov (United States)

Hazra, Rohan; Balis, Frank M; Tullio, Antonella N; DeCarlo, Ellen; Worrell, Carol J; Steinberg, Seth M; Flaherty, John F; Yale, Kitty; Poblenz, Marianne; Kearney, Brian P; Zhong, Lijie; Coakley, Dion F; Blanche, Stephane; Bresson, Jean Louis; Zuckerman, Judith A; Zeichner, Steven L

2004-01-01

Tenofovir disoproxil fumarate (DF) is a potent nucleotide analog reverse transcriptase inhibitor approved for the treatment of human immunodeficiency virus (HIV)-infected adults. The single-dose and steady-state pharmacokinetics of tenofovir were evaluated following administration of tenofovir DF in treatment-experienced HIV-infected children requiring a change in antiretroviral therapy. Using increments of tenofovir DF 75-mg tablets, the target dose was 175 mg/m(2); the median administered dose was 208 mg/m(2). Single-dose pharmacokinetics were evaluated in 18 subjects, and the geometric mean area under the concentration-time curve from 0 h to infinity (AUC(0- infinity )) was 2,150 ng. h/ml and the geometric mean maximum concentration (C(max)) was 266 ng/ml. Subsequently, other antiretrovirals were added to each patient's regimen based upon treatment history and baseline viral resistance results. Steady-state pharmacokinetics were evaluated in 16 subjects at week 4. The steady-state, geometric mean AUC for the 24-h dosing interval was 2,920 ng. h/ml and was significantly higher than the AUC(0- infinity ) after the first dose (P = 0.0004). The geometric mean C(max) at steady state was 302 ng/ml. Tenofovir DF was generally very well tolerated. Steady-state tenofovir exposures in children receiving tenofovir DF-containing combination antiretroviral therapy approached values seen in HIV-infected adults (AUC, approximately 3,000 ng. h/ml; C(max), approximately 300 ng/ml) treated with tenofovir DF at 300 mg.

PHARMACOKINETICS OF SINGLE-DOSE ORALLY ADMINISTERED CIPROFLOXACIN IN CALIFORNIA SEA LIONS (ZALOPHUS CALIFORNIANUS).

Science.gov (United States)

Barbosa, Lorraine; Johnson, Shawn P; Papich, Mark G; Gulland, Frances

2015-06-01

Ciprofloxacin is commonly selected for clinical use due to its broad-spectrum efficacy and is a frequently administered antibiotic at The Marine Mammal Center, a marine mammal rehabilitation facility. Ciprofloxacin is used for treatment of California sea lions ( Zalophus californianus ) suffering from a variety of bacterial infections at doses extrapolated from other mammalian species. However, as oral absorption is variable both within and across species, a more accurate determination of appropriate dosage is needed to ensure effective treatment and avoid emergence of drug-resistant bacterial strains. A pharmacokinetic study was performed to assess plasma concentrations of ciprofloxacin in California sea lions after a single oral dose. Twenty healthy California sea lions received a single 10-mg/kg oral dose of ciprofloxacin administered in a herring fish. Blood was then collected at two of the following times from each individual: 0.5, 0.75, 1, 2, 4, 8, 10, 12, 18, and 24 hr postingestion. Plasma ciprofloxacin concentration was assessed via high-performance liquid chromatography. A population pharmacokinetics model demonstrated that an oral ciprofloxacin dose of 10 mg/kg achieved an area under the concentration vs. time curve of 6.01 μg hr/ml. Absorption was rapid, with ciprofloxacin detectable in plasma 0.54 hr after drug administration; absorption half-life was 0.09 hr. A maximum plasma concentration of 1.21 μg/ml was observed at 1.01 hr, with an elimination half-life of 3.09 hr. Ciprofloxacin administered orally at 10 mg/kg produced therapeutic antibacterial exposure for only some of the most susceptible bacterial organisms commonly isolated from California sea lions.

Pharmacokinetic Effects of Antidrug Antibodies Occurring in Healthy Subjects After a Single Dose of Intravenous Infliximab.

Science.gov (United States)

Ehrenpreis, Eli D

2017-12-01

Infliximab pharmacokinetic studies have been performed in patients receiving chronic infliximab therapy. In these patients, infliximab antidrug antibodies (ADAs) increase infliximab clearance and decrease serum levels and drug efficacy. This study analyzed the pharmacokinetic effect of infliximab ADAs in healthy subjects receiving a single dose of intravenous infliximab. Data were obtained from a single-blind, parallel-group, single-dose study of healthy subjects receiving 5 mg/kg of intravenous SB2 (infliximab biosimilar), EU-sourced Remicade (EU-IFX) or US-sourced Remicade (US-IFX). Serum infliximab was measured at 1, 2, 3, 6, 12, 24, 48, and 72 h and at 5, 7, 14, 21, 28, 42, 56, and 70 days after administration. ADAs were measured pre-dose and at 29 and 71 days. Data from the first ten subjects randomized to each treatment arm were utilized for this study. A two-compartment model of the serum infliximab vs. time curve was developed using nonlinear regression. At 10 weeks, 11 subjects (37%) developed ADAs. ADAs were detected in four subjects after SB2, one subject after EU-IFX, and six subjects after US-IFX infusion. Of these, neutralizing antibodies occurred in one subject after SB2, in no subjects after EU-IFX, and in three subjects after US-IFX infusion. Infliximab clearance was increased in subjects with ADAs vs. those without ADAs (12.89 ± 2.69 vs. 9.90 ± 1.74 ml/h; p ADAs (282.4 ± 56.4 vs. 343.3 ± 61.9 h; p ADAs are common in healthy subjects after a single intravenous dose of infliximab and result in faster infliximab clearance, shorter elimination time, and lower serum infliximab levels. These data confirm that ADAs are common with biologic therapy and significantly impact the efficacy of these drugs.

[Bladder tumor lethality. Results in the autonomous community of Rioja between 1975-1991].

Science.gov (United States)

Fernández Fernández, A; Gil Fabra, J; Fernández Ruíz, M; Angulo Castellanos, M G; Blanco Martín, E; Otero Mauricio, G

1998-01-01

Between 1975-1991, a total of 557 cases of bladder carcinoma were identified in the Autonomous Community of La Rioja (CAR) which were followed up to December 1994. The overall lethality was 21.9%. 492 cases with 22.35% lethality were identified in males. In females, however, there was 65 cases with 18.46% lethality. The comparison of males and females lethality resulted in p = 0.525. Lethality between cases diagnosed within each 5-year period analyzed is: 1975-1981: 177 cases, lethality 23.72%. 1982-1986: 168 cases, lethality 30.95%. 1987-1991: 212 cases, lethality 13.20%. Between the first and the second 5-year periods, p = 0.132; between the first and third 5-year periods p = 0.007 and between the second and third 5-year periods p CAR for a 22.35% lethality. Lethality is higher in males that in females but the difference is not statistically significant. In the last 5-year period assessed, 1987-1991, a reduction of lethality from bladder neoplasms has been documented.

Population Pharmacokinetic Modelling of FE 999049, a Recombinant Human Follicle-Stimulating Hormone, in Healthy Women After Single Ascending Doses

DEFF Research Database (Denmark)

Rose, Trine Høyer; Röshammar, Daniel; Erichsen, Lars

2016-01-01

reproductive technologies. Methods: Serum FSH levels were measured following a single subcutaneous FE 999049 injection of 37.5, 75, 150, 225 or 450 IU in 27 pituitary-suppressed healthy female subjects participating in this first-in-human single ascending dose trial. Data was analysed by nonlinear mixed...... volume of distribution (V/F) estimates were found to increase with body weight. Body weight was included as an allometrically scaled covariate with a power exponent of 0.75 for CL/F and 1 for V/F. Conclusions: The single-dose pharmacokinetics of FE 999049 were adequately described by a population...

Effects of single and split doses of cobalt-60 gamma rays and 14 MeV neutrons on mouse stem cell spermatogonia.

Science.gov (United States)

Hacker-Klom, U B; Köhnlein, W; Göhde, W

2000-12-01

The long-term effects of ionizing radiation on male gonads may be the result of damage to spermatogonial stem cells. Doses of 10 cGy to 15 Gy (60)Co gamma rays or 10 cGy to 7 Gy 14 MeV neutrons were given to NMRI mice as single or split doses separated by a 24-h interval. The ratios of haploid spermatids/2c cells and the coefficients of variation of DNA histogram peaks as measures of both the cytocidal and the clastogenic actions of radiation were analyzed by DNA flow cytometry after DAPI staining. The coefficient of variation is not only a statistical examination of the data but is also used here as a measure of residual damage to DNA (i.e. a biological dosimeter). Testicular histology was examined in parallel. At 70 days after irradiation, the relative biological effectiveness for neutrons at 50% survival of spermatogonial stem cells was 3.6 for single doses and 2.8 for split doses. The average coefficient of variation of unirradiated controls of elongated spermatids was doubled when stem cells were irradiated with single doses of approximately 14 Gy (60)Co gamma rays or 3 Gy neutrons and observed 70 days later. Split doses of (60)Co gamma rays were more effective than single doses, doubling DNA dispersion at 7 Gy. No fractionation effect was found with neutrons with coefficients of variation.

Using the OSL single-aliquot regenerative-dose protocol with quartz extracted from building materials in retrospective dosimetry

International Nuclear Information System (INIS)

Boetter-Jensen, L.; Solongo, S.; Murray, A.S.; Banerjee, D.; Jungner, H.

2000-01-01

We report on the application of the single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence signal from quartz extracted from fired bricks and unfired mortar in retrospective dosimetry. The samples came from a radioactive materials storage facility, with ambient dose rates of about 0.1 mGy/h. A detailed dose-depth profile was analysed from one brick, and compared with dose records from area TL dosemeters. Small-aliquot dose-distributions were analysed from the mortar samples; one associated with the exposed brick, and one from a remote site exposed only to background radiation. We conclude that unfired materials have considerable potential in retrospective dosimetry

Repair of potentially lethal radiation damage: comparison of neutron and x-ray RBE and implications for radiation therapy

International Nuclear Information System (INIS)

Hall, E.J.; Kraljevic, U.

1976-01-01

Experiments with Chinese hamster cells have shown that neutron irradiation does not result in repair of potentially lethal damage (PLD), i.e., that which can be influenced by changes in environmental conditions following irradiation. Since PLD is presumed to be repaired in tumors but not in normal tissues, this absence of differential sparing of tumor cells relative to normal tissues--a feature characteristic of irradiation with x rays--represents an advantage of neutrons in addition to their reduced oxygen effect. At a given dose, the difference in relative biological effectiveness (RBE) between tumors and normal tissues corresponds to a 5 percent increase in tumor dose with no concomitant increase in dose to normal tissues, which could be significant in cancer therapy

Cell lethality after selective irradiation of the DNA replication fork

International Nuclear Information System (INIS)

Hofer, K.G.; Warters, R.L.

1985-01-01

It has been suggested that nascent DNA located at the DNA replication fork may exhibit enhanced sensitivity to radiation damage. To evaluate this hypothesis, Chinese hamster ovary cells (CHO) were labeled with 125 I-iododeoxyuridine ( 125 IUdR) either in the presence or absence of aphidicolin. Aphidicolin (5 μg/ml) reduced cellular 125 IUdR incorporation to 3-5% of the control value. The residual 125 I incorporation appeared to be restricted to low molecular weight (sub-replicon sized) fragments of DNA which were more sensitive to micrococcal nuclease attack and less sensitive to high salt DNase I digestion than randomly labeled DNA. These findings suggest that DNA replicated in the presence of aphidicolin remains localized at the replication fork adjacent to the nuclear matrix. Based on these observations an attempt was made to compare the lethal consequences of 125 I decays at the replication fork to that of 125 I decays randomly distributed over the entire genome. Regardless of the distribution of decay events, all treatment groups exhibited identical dose-response curves (D 0 : 101 125 I decays/cell). Since differential irradiation of the replication complex did not result in enhanced cell lethality, it can be concluded that neither the nascent DNA nor the protein components (replicative enzymes, nuclear protein matrix) associated with the DNA replication site constitute key radiosensitive targets within the cellular genome. (orig.)

8 Gy single-dose radiotherapy is effective in metastatic spinal cord compression: Results of a phase III randomized multicentre Italian trial

International Nuclear Information System (INIS)

Maranzano, Ernesto; Trippa, Fabio; Casale, Michelina; Costantini, Sara; Lupattelli, Marco; Bellavita, Rita; Marafioti, Luigi; Pergolizzi, Stefano; Santacaterina, Anna; Mignogna, Marcello; Silvano, Giovanni; Fusco, Vincenzo

2009-01-01

Background and purpose: In a previous randomized trial we showed that the short-course radiotherapy (RT) regimen of 8 Gy x 2 was feasible in patients with metastatic spinal cord compression (MSCC) and short life expectancy. This phase III trial was planned to determine whether in the same category of patients 8 Gy single-dose is as effective as 8 Gy x 2. Materials and methods: Three hundred and twenty-seven patients with MSCC and short life expectancy were randomly assigned to a short-course of 8 Gy x 2 or to 8 Gy single-dose RT. Median follow-up was 31 months (range, 4-58). Results: A total of 303 (93%) patients are assessable, 150 treated with the short-course and 153 with the single-dose RT. No difference in response was found between the two RT schedules adopted. Median duration of response was 5 and 4.5 months for short-course and single-dose RT (p = 0.4), respectively. The median overall survival was 4 months for all cases. Light acute toxicity was registered in a minority of cases. Late toxicity was never recorded. Conclusions: Both RT schedules adopted were effective. As already shown in several trials evaluating RT regimens in uncomplicated painful bone metastases, also MSCC patients may achieve palliation with minimal toxicity and inconvenience with a single-dose of 8 Gy.

The Effect of Nicotine Administration on Physical and Psychological Signs of Withdrawal Syndrome Induced by Single or Frequent Doses of Morphine in Rats

Directory of Open Access Journals (Sweden)

Mohammad Allahtavakoli

2012-07-01

Full Text Available Introduction. Morphine addiction and morphine withdrawal syndrome are the two main problems of today’s human society. The present study has investigated the effects of nicotine on the strength of physical and psychological dependency in single and repeated doses morphine administrated rats. Materials and methods. Male Wistar rats were subjected to morphine consumption with single or frequent dose protocols. In the single dose protocol, rats received only one dose of morphine and 24hrs later they also received one dose of nicotine 30 min prior to injection of naloxone. In the repeated dose protocol, rats received incremental doses of morphine for 7 days and 24hr after the last dose (the 8th day were given naloxone. However, the nicotine regimen of this group was injected 15 min before the morphine injection, for 4 days, from the 4th to the 7th day. Five minutes after naloxone injection, each rat′s behavior was captured for 30 min, and then physical and psychological signs of withdrawal syndrome were recorded. Data were analyzed by ANOVA followed by Tukey tests and p<0.05 was considered as significant difference. Findings. Results showed that the injection of frequent and single doses of morphine lead to morphine dependency. In single dose protocol, nicotine consumption attenuated the signs of withdrawal syndrome, especially weight of excrement and total withdrawal score. In frequent dose protocol, in addition to these effects, nicotine induced weight loss and place aversion. Conclusion. The inhibitory effects of nicotine on signs of withdrawal syndrome may involve a dopaminergic portion of the central nervous system and is mediated by central nicotinic receptors. There is also a cross-dependence between nicotine and morphine.

A Single-Dose, Single-Period Pharmacokinetic Assessment of an Extended-Release Orally Disintegrating Tablet of Methylphenidate in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder.

Science.gov (United States)

Childress, Ann; Newcorn, Jeffrey; Stark, Jeffrey G; McMahen, Russ; Tengler, Mark; Sikes, Carolyn

2016-08-01

To determine the pharmacokinetic (PK) profile of a proprietary formulation of methylphenidate (MPH) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) in a phase 1 study. Methylphenidate extended-release orally disintegrating tablets (MPH XR-ODTs) combine two technologies in a single-tablet formulation-an extended-release profile that was designed for once-daily dosing in an ODT that does not require water or chewing for ingestion. This was a single-dose, open-label, single-period, single-treatment study, in which 32 children with ADHD who were receiving MPH in doses of 40 or 60 mg before beginning the study each received a 60-mg dose (2 × 30 mg) of MPH XR-ODT. The following plasma PK parameters of MPH were determined for participants grouped by age (6-7, 8-9, 10-12, and 13-17 years old): maximum concentration (Cmax), time to maximum concentration (Tmax), elimination half-life (T½), area under the curve from 0 hours to infinity (AUCinf), oral clearance (CL/F), and volume of distribution in the terminal phase (Vz/F). Safety and tolerability were also assessed. A total of 32 participants received the study drug. For all participants, plasma concentration-time profiles of MPH exhibited a broad peak after administration of MPH XR-ODT through ∼8 hours, indicating extended release from the formulation, followed by an apparent first-order elimination phase. As age increased, MPH exposure decreased and mean estimates of CL/F increased; however, weight-normalized CL/F values were comparable across age groups. Similarly, mean estimates of Vz/F increased with age, but weight-normalization decreased differences across age groups, with the exception of the youngest age group, which had higher values. All adverse events (AEs) were mild. This XR-ODT formulation of MPH demonstrated weight-normalized clearance rates that were consistent across all age groups, a PK profile consistent with once-daily dosing, and an AE profile consistent with

Disposition and metabolism of codeine after single and chronic doses in one poor and seven extensive metabolisers.

Science.gov (United States)

Chen, Z R; Somogyi, A A; Reynolds, G; Bochner, F

1991-04-01

1. The pharmacokinetics, metabolism and partial clearances of codeine to morphine, norcodeine and codeine-6-glucuronide after single (30 mg) and chronic (30 mg 8 h for seven doses) administration of codeine were studied in eight subjects (seven extensive and one poor metaboliser of dextromethorphan). Codeine, codeine-6-glucuronide, morphine and norcodeine were measured by high performance liquid chromatographic assays. 2. After the single dose, the time to achieve maximum plasma codeine concentrations was 0.97 +/- 0.31 h (mean +/- s.d.) and for codeine-6-glucuronide it was 1.28 +/- 0.49 h. The plasma AUC of codeine-6-glucuronide was 15.8 +/- 4.5 times higher than that of codeine. The AUC of codeine in saliva was 3.4 +/- 1.1 times higher than that in plasma. The elimination half-life of codeine was 3.2 +/- 0.3 h and that of codeine-6-glucuronide was 3.2 +/- 0.9 h. 3. The renal clearance of codeine was 183 +/- 59 ml min-1 and was inversely correlated with urine pH (r = 0.81). These data suggest that codeine undergoes filtration at the glomerulus, tubular secretion and passive reabsorption. The renal clearance of codeine-6-glucuronide was 55 +/- 21 ml min-1, and was not correlated with urine pH. Its binding to human plasma was less than 10%. These data suggest that codeine-6-glucuronide undergoes filtration at the glomerulus and tubular reabsorption. This latter process is unlikely to be passive. 4. After chronic dosing, the pharmacokinetics of codeine and codeine-6-glucuronide were not significantly different from the single dose pharmacokinetics. 5. After the single dose, 86.1 +/- 11.4% of the dose was recovered in urine, of which 59.8 +/- 10.3% was codeine-6-glucuronide, 7.1 +/- 1.1% was total morphine, 6.9 +/- 2.1% was total norcodeine and 11.8 +/- 3.9% was unchanged codeine. These recoveries were not significantly different (P greater than 0.05) after chronic administration. 6. After the single dose, the partial clearance to morphine was 137 +/- 31 ml min-1 in

Palonosetron-A Single-Dose Antiemetic Adjunct for Hepatic Artery Radioembolization: A Feasibility Study

International Nuclear Information System (INIS)

Siddiqi, Nasir H.; Khan, Atif J.; Devlin, Phillip M.

2009-01-01

Nausea and vomiting may occur in a significant minority of patients following hepatic artery embolization with yttrium-90 spheres (K. T. Sato et al. Radiology 247:507-515, 2008). This encumbers human and economic resources and undercuts the assertion that it is as a well-tolerated outpatient treatment. A single intravenous dose of palonosetron HCl was administered before hepatic artery embolization with yttrium-90 spheres to ameliorate posttreatment nausea and vomiting, in 23 consecutive patients. The patients were discharged the day of procedure on oral antiemetics, steroids, and blockers of gastric acid release. All patients had clinical and laboratory evaluation at 2 weeks after the procedure. The data were gathered and reviewed retrospectively. At 2-week follow-up, none reported significant nausea, vomiting, additional antiemetic use, need for parenteral therapy, hospital readmission, or palonosetron-related side effects. All patients recovered from postembolization symptoms within a week after treatment. In conclusion, this retrospective study suggests that single-dose palonosetron is feasible, safe, and effective for acute and delayed nausea and vomiting in this group of patients. The added cost may be offset by benefits.

Effects of local single and fractionated X-ray doses on rat bone marrow blood flow and red blood cell volume

International Nuclear Information System (INIS)

Pitkaenen, M.A.; Hopewell, J.W.

1985-01-01

Time and dose dependent changes in blood flow and red blood cell volume were studied in the locally irradiated bone marrow of the rat femur after single and fractionated doses of X-rays. With the single dose of 10 Gy the bone marrow blood flow although initially reduced returned to the control levels by seven months after irradiation. With doses >=15 Gy the blood flow was still significantly reduced at seven months. The total dose levels predicted by the nominal standard dose equation for treatments in three, six or nine fractions produced approximately the same degree of reduction in the bone marrow blood flow seven months after the irradiation. However, the fall in the red blood cell volume was from 23 to 37% greater in the three fractions groups compared with that in the nine fractions groups. Using the red blood cell volume as a parameter the nominal standard dose formula underestimated the severity of radiation damage in rat bone marrow at seven months for irradiation with small numbers of large dose fractions. (orig.) [de

RBE-LET relationships for different types of lethal radiation damage in mammalian cells: comparison with DNA dsb and an interpretation of differences in radiosensitivity

NARCIS (Netherlands)

Barendsen, G. W.

1994-01-01

Relative biological effectiveness (RBE), as a function of linear energy transfer (LET), is evaluated for different types of damage contributing to mammalian cell reproductive death. Survival curves are analysed assuming a linear-quadratic dose dependence of lethal lesions. The linear term represents

Study on dose-effect relationship of radiation-induced DNA damage using single cell gel electrophoresis

International Nuclear Information System (INIS)

Liu Qiang; Jiang Enhai; Li Jin; Tang Weisheng; Wang Zhiquan; Zhao Yongcheng; Fan Feiyue

2006-01-01

Objective: To explore a new, simple and quick radiation biodosimeter, which can be applied to estimate biological dose in case of radiation accident. Methods: DNA double-strand break were detected using neutral single cell gel electrophoresis (SCGE), and all the indexes of comet assay including HDNA%, TDNA%, CL, TL, TM, and OTM were analyzed by CASP (Comet Assay Software Project). The curve of dose-effect was fitted using SPSS 12.0 software. Results: Statistically significant dose-effect relationships were observed in all the indexes of comet assay, OTM was superior to other indexes. Conclusions: Application of neutral comet assay combined with CASP analysis could serve as a new radiation biodosimeter. (authors)

Humanitarian Algorithms : A Codified Key Safety Switch Protocol for Lethal Autonomy

OpenAIRE

Nyagudi, Nyagudi Musandu

2014-01-01

With the deployment of lethal autonomous weapons, there is the requirement that any such platform complies with the precepts of International Humanitarian Law. Humanitarian Algorithms[9: p. 9] ensure that lethal autonomous weapon systems perform military/security operations, within the confines of International Humanitarian Law. Unlike other existing techniques of regulating lethal autonomy this scheme advocates for an approach that enables Machine Learning. Lethal autonomous weapons must be ...

A STUDY OF IMMUNOGENIC AND PROTECTIVE PROPERTIES OF THE HEAT-STABLE LETHAL TOXIN OF YERSINIA PSEUDOTUBERCULOSIS AND ITS EFFECTS UPON HEMATOLOGICAL AND BLOOD CYTOKINE PARAMETERS OF LABORATORY MICE

Directory of Open Access Journals (Sweden)

A. V. Tsybulsky

2014-01-01

Full Text Available The article presents some data concerning antigenic and immunogenic properties of the lethal heat-stable toxin (HST from Yersinia pseudotuberculosis, a protein with molecular weight of 45 kDa. The mice,following double immunization with HST at a dose of 0.1 mg per mouse, displayed higher antibody production, in comparison with a dose of 0.01 mg/mouse. The appropriate differences were revealed with regard ofleukocyte responses, i.e., development of leukopenia, neutropenia, lymphopenia upon immunization with the 0.01 mg of HST per mouse, whereas leukocytosis, and increase in lymphocytes and monocytes was detected after a dose of 0.1 mg/mouse. We detected some doseependent differences in cytokine-modulating activity. I.e., at HST dose of 0.01 mg per mouse, we detected mostly proinflammatory, acutehase responses, whereas a dose of 0.1 mg/mice caused induction of . IFNγ and cytokines promoting lymphocyte proliferation and antibody production by day +17. Upon double immunization of mice, the toxin showed protective properties when injecting them with lethal dose of Y. pseudotuberculosis. A lagging activation of antibody producers duringHST response suggests a need for searching effective adjuvant tools of enhancement and acceleration of specific humoral immune reactions against this antigen.

Loss of ATM kinase activity leads to embryonic lethality in mice

DEFF Research Database (Denmark)

Daniel, J.A.; Pellegrini, M.; Filsuf, D.

2012-01-01

whether the functions of ATM are mediated solely by its kinase activity, we generated two mouse models containing single, catalytically inactivating point mutations in Atm. In this paper, we show that, in contrast to Atm-null mice, both D2899A and Q2740P mutations cause early embryonic lethality in mice......, without displaying dominant-negative interfering activity. Using conditional deletion, we find that the D2899A mutation in adult mice behaves largely similar to Atm-null cells but shows greater deficiency in homologous recombination (HR) as measured by hypersensitivity to poly (adenosine diphosphate...

Regulatory T Cell Responses in Participants with Type 1 Diabetes after a Single Dose of Interleukin-2: A Non-Randomised, Open Label, Adaptive Dose-Finding Trial

Science.gov (United States)

Todd, John A.; Porter, Linsey; Smyth, Deborah J.; Rainbow, Daniel B.; Ferreira, Ricardo C.; Yang, Jennie H.; Bell, Charles J. M.; Schuilenburg, Helen; Challis, Ben; Clarke, Pamela; Coleman, Gillian; Dawson, Sarah; Goymer, Donna; Kennet, Jane; Brown, Judy; Greatorex, Jane; Goodfellow, Ian; Evans, Mark; Mander, Adrian P.; Bond, Simon; Wicker, Linda S.

2016-01-01

Background Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target. Aldesleukin (Proleukin; recombinant human IL-2), which is administered at high doses to activate the immune system in cancer immunotherapy, is now being repositioned to treat inflammatory and autoimmune disorders at lower doses by targeting Tregs. Methods and Findings To define the aldesleukin dose response for Tregs and to find doses that increase Tregs physiologically for treatment of T1D, a statistical and systematic approach was taken by analysing the pharmacokinetics and pharmacodynamics of single doses of subcutaneous aldesleukin in the Adaptive Study of IL-2 Dose on Regulatory T Cells in Type 1 Diabetes (DILT1D), a single centre, non-randomised, open label, adaptive dose-finding trial with 40 adult participants with recently diagnosed T1D. The primary endpoint was the maximum percentage increase in Tregs (defined as CD3+CD4+CD25highCD127low) from the baseline frequency in each participant measured over the 7 d following treatment. There was an initial learning phase with five pairs of participants, each pair receiving one of five pre-assigned single doses from 0.04 × 106 to 1.5 × 106 IU/m2, in order to model the dose-response curve. Results from each participant were then incorporated into interim statistical modelling to target the two doses most likely to induce 10% and 20% increases in Treg frequencies. Primary analysis of the evaluable population (n = 39) found that the optimal doses of aldesleukin to induce 10% and 20% increases in Tregs were 0.101 × 106 IU/m2 (standard error [SE] = 0.078, 95% CI = −0

Non-Lethal Weapons Program

Science.gov (United States)

Sheets Frequently Asked Questions Non-Lethal Weapons FAQs Active Denial System FAQs Human Electro -Muscular Incapacitation FAQs Related Links Business Opportunities Contact JNLWD Congressional Engagement , Wednesday, Sept 20, 2017. The Active Denial System, blunt-impact munitions, dazzling lasers, LRAD 100X

Pharmacokinetics of diclofenac in pigs after intramuscular administration of a single dose

OpenAIRE

Pejčić Zorica; Pokrajac Milena; Jezdimirović Milanka

2006-01-01

The pharmacokinetics of diclofenac was studied in 10 clinically normal male Yorkshire pigs, following intramuscular (i.m) administration of a single dose of diclofenac-sodium (2.5 mg/kg body weight). Diclofenac serum concentrations were determined by high pressure- liquid-chromatography (HPLC), with UV detection (226 nm). Following i.m. administration all individual diclofenac serum levels best fitted the one-compartment open model for extravascular administration. The maximal diclofenac seru...

A quantitative assessment of changes in the dermal fibroblast population of pig skin after single doses of X-rays

International Nuclear Information System (INIS)

Hamlet, R.; Hopewell, J.W.

1988-01-01

Changes in the density of fibroblast nuclei in reticular dermis of pigs was studied from 6 to 104 weeks after a single dose of 15.4 Gy of X-rays. The largest decrease in fibroblasts occurred between 12 and 26 weeks after irradiation; after this there was only a slight fall in fibroblast number until 104 weeks when observations ceased. At 26 weeks and later times after irradiation reduction in the density of fibroblast nuclei in the reticular dermis was dose-dependent for single doses in the range 8.0-20.7 Gy. The dose-response curve had an initial shoulder, after which the fall in the fibroblast nuclear density was linearly related to dose. Data obtained between 26 weeks and 104 weeks after irradiation, could be fitted by the same dose-response curve. The fall in the counts of fibroblast nuclei was compared with earlier studies. The loss of fibroblasts occurred after an initial reduction in blood flow in the pig skin but was concomitant with general reduction in dermal thickness. (author)

Biological impact of high-dose and dose-rate radiation exposure

International Nuclear Information System (INIS)

Maliev, V.; Popov, D.; Jones, J.; Gonda, S.; Prasad, K.; Viliam, C.; Haase, G.; Kirchin, V.; Rachael, C.

2006-01-01

Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

Biological impact of high-dose and dose-rate radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Maliev, V.; Popov, D. [Russian Academy of Science, Vladicaucas (Russian Federation); Jones, J.; Gonda, S. [NASA -Johnson Space Center, Houston (United States); Prasad, K.; Viliam, C.; Haase, G. [Antioxida nt Research Institute, Premier Micronutrient Corporation, Novato (United States); Kirchin, V. [Moscow State Veterinary and Biotechnology Acade my, Moscow (Russian Federation); Rachael, C. [University Space Research Association, Colorado (United States)

2006-07-01

Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

Treatment of chronic spontaneous urticaria with a single dose of omalizumab: A study of four cases

Directory of Open Access Journals (Sweden)

Radhakrishnan Subramaniyan

2016-01-01

Full Text Available Background: Chronic spontaneous urticaria (CSU has a detrimental effect on patients′ emotional and physical quality of life. Omalizumab, an anti-immunoglobulin E humanized monoclonal antibody, has been shown to be very effective in the treatment of refractory chronic urticaria patients but may not be an economically viable option for all CSU patients. However, we present a case series where a single dose of omalizumab gave sustained relief of symptoms in patients with CSU, which may be an economical option. Aims: The aim of this study is to assess the efficacy of a single dose of omalizumab in the treatment of CSU. Materials and Methods: Four patients of CSU whose disease was not controlled with four times the licensed dose of tablet fexofenadine 180 mg were exhibited one subcutaneous injection of omalizumab and were followed up at 4 weekly intervals for 24 weeks for Weekly Urticaria Activity Score 7 (UAS7 and Dermatology Life Quality Index (DLQI. Results: A sharp decline in UAS7 and DLQI was documented in 7-10 days. The decline was maintained up to 16 weeks in one case and 20 weeks in the other three cases. Both the scores at the end of the follow-up period of 24 weeks were better than the pre-omalizumab scores. Conclusion: The results of this case series indicate the efficacy of a single-dose omalizumab in treating moderate to severe refractory CSU. Further studies are required to identify the minimum frequency of administering omalizumab to effectively control CSU. This would greatly reduce the cost of this novel therapy.

Effect of a single dose of dextromethorphan on psychomotor performance and working memory capacity.

Science.gov (United States)

Al-Kuraishy, Hayder M; Al-Gareeb, Ali I; Ashor, Ammar Waham

2012-04-01

Previous studies show that the prolonged use of dextromethorphan produces cognitive deterioration in humans. The aim of this study was to investigate the effect of a single dose of dextroemthrophan on psychomotor performance and working memory capacity. This is a randomized, double-blind, controlled, and prospective study. Thirty-six (17 women, 19 men) medical students enrolled in the study; half of them (7 women, 11 men) were given placebo, while the other half (10 women, 8 men) received dextromethorphan. The choice reaction time, critical flicker fusion threshold, and N-back working memory task were measured before and after 2 h of taking the drugs. Dextromethorphan showed a significant deterioration in the 3-back working memory task (P0.05). On the other hand, placebo showed no significant changes as regards the choice reaction time, critical flicker fusion threshold, and N-back working memory task (P>0.05). A single dose of dextromethorphan has no effect on attention and arousal but may significantly impair the working memory capacity.

Distribution of 99Tcm-rh-Annexin vin tumor and expression relationship of bcl-2, bax after a single dose of chemotherapy

International Nuclear Information System (INIS)

Zhang Xin; Li Yaming; Zhang Yanjun; Tao Li; Zhu Yi; Yang Chun; Ji Xiaopeng; Zhao Ming; Tian Aijuan; Zhang Jianying; Zhao Zhenzhen

2007-01-01

The expression of bcl-2 and bax after the single dose of chemotherapy with 99 Tc m -rh-Annexin V as the tracer of tumor apoptosis imaging is studied. tumor cell apoptosis is examined by TUNEL methods, and the expression of bcl-2 and bax in tumor are determined by immunohistochemical methods. Single dose of chemotherapy significantly increased the tumor uptake of 99 Tc m -rh-annexin V and the positive number of TUNEL, as well as the expression of bax (P 99 Tc m -rh-annexin V in tumor reflectes not only the degree of apoptosis of tumor cells, but also the change of bax expression after the single dose of chemotherapy. (authors)

Effects of single dose X-irradiation on the guinea-pig spinal cord

Energy Technology Data Exchange (ETDEWEB)

Knowles, J F [Medical Research Council, Harwell (UK). Radiobiological Research Unit

1981-09-01

Lumbar or cervical regions of the guinea-pig spinal cord were irradiated with a single dose of 250 kV X-rays. The latency for paralysis, whether of hind- or fore-limbs, and the histopathology of the radiation-induced cord lesions depended critically on the radiation dose. There were definite but only minor differences between the reactions of lumbar and cervical cord to the same radiation dose. After 30 or 40 Gy there was white matter necrosis but after 20 Gy widespread demyelination associated with vacuolar spaces occurred. After irradiation of the lumbar cord with 30-40 Gy, the lesions in the guinea-pig differed from those reported in the rat. White-matter necrosis in the guinea-pig cord was only occasionally associated with spinal nerve root necrosis, whereas in the rat, nerve-root necrosis with sparing of the white matter was the main lesion. After 20 Gy to the cervical or lumbar cord the guinea-pig showed widespread demyelination and vacuolation whereas in rats vascular lesions were the main result.

Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

International Nuclear Information System (INIS)

Lee, Eun-Jung; Kim, Jun Won; Yoo, Hyun; Kwak, Woori; Choi, Won Hoon; Cho, Seoae; Choi, Yu Jeong; Lee, Yoon-Jin; Cho, Jaeho

2015-01-01

We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm 2 fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL-33

Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Jung, E-mail: forejs2@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jun Won, E-mail: JUNWON@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Yoo, Hyun, E-mail: gochunghee@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kwak, Woori, E-mail: asleo02@snu.ac.kr [Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-747 (Korea, Republic of); Choi, Won Hoon, E-mail: wonhoon@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Cho, Seoae, E-mail: seoae@cnkgenomics.com [C& K Genomics, Seoul National University Mt.4-2, Main Bldg. #514, SNU Research Park, NakSeoungDae, Gwanakgu, Seoul 151-919 (Korea, Republic of); Choi, Yu Jeong, E-mail: yunk9275@daum.net [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Lee, Yoon-Jin, E-mail: yjlee8@kirams.re.kr [Division of Radiation Effects, Research Center for Radiotherapy, Korea Institute of Radiological & Medical Sciences, Seoul 139-760 (Korea, Republic of); Cho, Jaeho, E-mail: jjhmd@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of)

2015-08-14

We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm{sup 2} fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL

Non-Lethal Weapons: Opportunities for R&D

Science.gov (United States)

2004-12-01

during the Vietnam War. US; emulsifying agents are used in food processing, drilling fluids, cosmetics , pharmaceuticals, heavy- duty cleaners, textile...conducted in a professional manner, with no threat to public safety or the environment. 11 References [1] Fenton , G., (2001). NLW Technology Taxonomy...W.A., Mason, R.L., Collins, K.R., (2000). Non-Lethal Applicants of Slippery Substances. NDIA Non-Lethal Defense IV. [24] Fenton , G., (2000). Overview

Administration of single-dose GnRH agonist in the luteal phase in ICSI cycles: a meta-analysis

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Oliveira João

2010-09-01

Full Text Available Abstract Background The effects of gonadotrophin-releasing hormone agonist (GnRH-a administered in the luteal phase remains controversial. This meta-analysis aimed to evaluate the effect of the administration of a single-dose of GnRH-a in the luteal phase on ICSI clinical outcomes. Methods The research strategy included the online search of databases. Only randomized studies were included. The outcomes analyzed were implantation rate, clinical pregnancy rate (CPR per transfer and ongoing pregnancy rate. The fixed effects model was used for odds ratio. In all trials, a single dose of GnRH-a was administered at day 5/6 after ICSI procedures. Results All cycles presented statistically significantly higher rates of implantation (P Conclusions These findings demonstrate that the luteal-phase single-dose GnRH-a administration can increase implantation rate in all cycles and CPR per transfer and ongoing pregnancy rate in cycles with GnRH antagonist ovarian stimulation protocol. Nevertheless, by considering the heterogeneity between the trials, it seems premature to recommend the use of GnRH-a in the luteal phase. Additional randomized controlled trials are necessary before evidence-based recommendations can be provided.

Fluralaner as a single dose oral treatment for Caparinia tripilis in a pygmy African hedgehog.

Science.gov (United States)

Romero, Camilo; Sheinberg Waisburd, Galia; Pineda, Jocelyn; Heredia, Rafael; Yarto, Enrique; Cordero, Alberto M

2017-12-01

African pygmy hedgehogs (Atelerix albiventris) are popular pets belonging to the Erinaceidae family of spined mammals. Amongst the most common skin diseases occurring in this species is infestation caused by the mite Caparinia spp. Due to their skin anatomy and spiny coat, detection of skin lesions in these hedgehogs can be difficult. This may result in delays in seeking medical care, which may lead to secondary bacterial infection and self-inflicted trauma. Multiple therapies have been used in the treatment of this skin condition including ivermectin, amitraz, fipronil and selamectin. A drug which could be administered as a single oral dose would be advantageous to these pets and their owners. To evaluate the effect of a single oral dose (15 mg/kg) of fluralaner on Caparinia tripilis infestation in the African pygmy hedgehog. A 10-month-old African pygmy hedgehog weighing 184 g. Response to treatment was monitored by dermatological examination and superficial skin scrapings repeated at 7, 14, 21, 30, 60, 90 and 120 days following fluralaner administration. On Day 7 after treatment, adult mites were observed exhibiting normal movement. On Day 14, only dead mites were observed. No life stages of the mites were found after Day 21. A single oral dose at 15 mg/kg of fluralaner was effective within 21 days after treatment for capariniasis in this case. Further studies are required to evaluate the drug's safety and toxicology in hedgehogs, and to confirm efficacy. © 2017 ESVD and ACVD.

Frequency of wound infection in non-perforated appendicitis with use of single dose perforative antibiotics

International Nuclear Information System (INIS)

Ali, K.; Latif, H.; Ahmad, S.

2015-01-01

Antibiotics are used both pre and post-operatively in acute appendicitis for preventing wound infection. It has been observed that the routine use of post-operative antibiotics is not necessary in cases of non-perforated appendicitis as only prophylactic antibiotics are sufficient to prevent wound infection. The aim of this study was to see the frequency of wound infection in non-perforated appendicitis with single dose preoperative antibiotics only. Method: This observational study was conducted at the Department of Surgery, Ayub Medical College, Abbottabad from May to November 2014. A total of 121 patients with non-perforated appendicitis were included in the study. Only single dose preoperative antibiotics were used. The patients were followed for wound infection till 8th post-operative day. Results: 121 patients, 56(46.28%) male and 65(53.72%) female were included in the study. The mean age of patients was 27.41 ± 7.12 years with an age range of 18 to 45 years. In the entire series, 7(5.78%) patients developed wound infection. The infection was minor which settled with conservative therapy. Prophylactic antibiotics were found efficacious in 114(94.21%) patients. There was no significant association between wound infection and age and gender. Conclusion: Single dose preoperative antibiotics were found effective in controlling post-operative wound infection without the need of extending the antibiotics to post-operative period in cases of non-perforated appendicitis. (author)

Effect of single oral dose of tramadol on gastric secretions pH

Directory of Open Access Journals (Sweden)

Khan Mueen Ullah

2015-01-01

Full Text Available Background: Tramadol is an atypical analgesic agent. It has been shown that intramuscular or intravenous injection tramadol is able to inhibit M3 muscarinic receptors. Tramadol is able to mediate smooth muscles contraction and glandular secretions. We have evaluated the effects of single oral dose of tramadol given preoperatively on gastric juices pH in patients electively scheduled for laparoscopic cholecystectomy. Materials and Methods: Sixty adult, American Society of Anesthesiologist I and II patients scheduled for laparoscopic cholecystectomy were included in the study. Patients were randomly assigned to receive either placebo (n = 30 or oral tramadol 50 mg (n = 30. General anesthesia was induced using propofol, fentanyl and cisatracurium. After induction of anesthesia 5 ml of gastric fluid was aspirated through orogastric tube. The gastric fluid pH was measured using pH meter. Result: There was no significant difference in the pH between the groups. Gastric pH of the placebo and tramadol groups was 1.97 versus 1.98 (P = 0.092 respectively. Conclusion: Preoperatively single oral dose of tramadol was unable to elevate the desired level of gastric acid secretions pH (>2.5. This may be due to pharmacokinetic disparity between the analgesic and pH elevating properties of tramadol.

[Underlying Mechanisms of Methamphetamine-Induced Self-Injurious Behavior and Lethal Effects in Mice].

Science.gov (United States)

Mori, Tomohisa; Sawaguchi, Toshiko

2018-01-01

Relatively high doses of psychostimulants induce neurotoxicity on the dopaminergic system and self-injurious behavior (SIB) in rodents. However the underlying neuronal mechanisms of SIB remains unclear. Dopamine receptor antagonists, N-methyl-D-aspartic acid (NMDA) receptor antagonists, Nitric Oxide Synthase (NOS) inhibitors and free radical scavengers significantly attenuate methamphetamine-induced SIB. These findings indicate that activation of dopamine as well as NMDA receptors followed by radical formation and oxidative stress, especially when mediated by NOS activation, is associated with methamphetamine-induced SIB. On the other hand, an increase in the incidence of polydrug abuse is a major problem worldwide. Coadministered methamphetamine and morphine induced lethality in more than 80% in mice, accompanied by an increase in the number of poly (ADP-ribose) polymerase (PARP)-immunoreactive cells in the heart, kidney and liver. The lethal effect and the increase in the incidence of rupture or PARP-immunoreactive cells induced by the coadministration of methamphetamine and morphine were significantly attenuated by pretreatment with a phospholipase A2 inhibitor or a radical scavenger, or by cooling of body from 30 to 90 min after drug administration. These results suggest that free radicals play an important role in the increased lethality induced by the coadministration of methamphetamine and morphine. Therefore, free radical scavengers and cooling are beneficial for preventing death that is induced by the coadministration of methamphetamine and morphine. These findings may help us better understand for masochistic behavior, which is a clinical phenomenon on SIB, as well as polydrug-abuse-induced acute toxicity.

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.

Serum tocopherol levels in very preterm infants after a single dose of vitamin E at birth.

Science.gov (United States)

Bell, Edward F; Hansen, Nellie I; Brion, Luc P; Ehrenkranz, Richard A; Kennedy, Kathleen A; Walsh, Michele C; Shankaran, Seetha; Acarregui, Michael J; Johnson, Karen J; Hale, Ellen C; Messina, Lynn A; Crawford, Margaret M; Laptook, Abbot R; Goldberg, Ronald N; Van Meurs, Krisa P; Carlo, Waldemar A; Poindexter, Brenda B; Faix, Roger G; Carlton, David P; Watterberg, Kristi L; Ellsbury, Dan L; Das, Abhik; Higgins, Rosemary D

2013-12-01

Our aim was to examine the impact of a single enteral dose of vitamin E on serum tocopherol levels. The study was undertaken to see whether a single dose of vitamin E soon after birth can rapidly increase the low α-tocopherol levels seen in very preterm infants. If so, this intervention could be tested as a means of reducing the risk of intracranial hemorrhage. Ninety-three infants vitamin E or placebo by gastric tube within 4 hours of birth. The vitamin E group received 50 IU/kg of vitamin E as dl-α-tocopheryl acetate (Aquasol E). The placebo group received sterile water. Blood samples were taken for measurement of serum tocopherol levels by high-performance liquid chromatography before dosing and 24 hours and 7 days after dosing. Eighty-eight infants received the study drug and were included in the analyses. The α-tocopherol levels were similar between the groups at baseline but higher in the vitamin E group at 24 hours (median 0.63 mg/dL vs. 0.42 mg/dL, P = .003) and 7 days (2.21 mg/dL vs 1.86 mg/dL, P = .04). There were no differences between groups in γ-tocopherol levels. At 24 hours, 30% of vitamin E infants and 62% of placebo infants had α-tocopherol levels vitamin E raised serum α-tocopherol levels, but to consistently achieve α-tocopherol levels >0.5 mg/dL, a higher dose or several doses of vitamin E may be needed.

Effect of single-dose radiation on cell survival and growth hormone secretion by rat anterior pituitary cells

International Nuclear Information System (INIS)

Hochberg, Z.; Kuten, A.; Hertz, P.; Tatcher, M.; Kedar, A.; Benderly, A.

1983-01-01

Cranial irradiation has been shown to impair growth hormone secretion in children. In this study a cell culture of dispersed rat anterior pituitary cells was exposed to single doses of radiation in the range of 100 to 1500 rad. Survival curves were obtained for the different anterior pituitary cell lines, and growth hormone secretion was measured in the tissue culture medium. Both survival and growth hormone secretion curves showed an initial shoulder in the range of 0 to 300 rad, followed by a decline between 300 to 750 rad. It is concluded that growth hormone secreting acidophilic pituicytes are sensitive to radiation at single doses greater than 300 rad

Single-dose and fractionated irradiation of four human lung cancer cell lines in vitro

International Nuclear Information System (INIS)

Brodin, O.; Lennartsson, L.; Nilsson, S.

1991-01-01

Four established human lung cancer cell lines were exposed to single-dose irradiation. The survival curves of 2 small cell lung carcinomas (SCLC) were characterized by a limited capacity for repair with small and moderate shoulders with extrapolation numbers (n) of 1.05 and 1.60 respectively. Two non-small cell lung carcinoma (NSCLC) cell lines, one squamous cell (SQCLC) and one large cell (LCLC) had large shoulders with n-values of 73 and 15 respectively. The radiosensitivity when measured as D 0 did not, however, differ as much from cell line to cell line, with values from 1.22 to 1.65. The surviving fraction after 2 Gy (SF2) was 0.24 and 0.42 respectively in the SCLC cell lines and 0.90 and 0.88 respectively in the NSCLC cell lines. Fractionated irradiation delivered according to 3 different schedules was also investigated. All the schedules delivered a total dose of 10 Gy in 5 days and were applied in 1, 2 and 5 Gy dose fractions respectively. Survival followed the pattern found after single-dose irradiation; it was lowest in the SCLC cell line with the lowest SF and highest in the two NSCLC cell lines. In the SCLC cell lines all schedules were approximately equally efficient. In the LCLC and in the SQCLC cell lines, the 5 Gy schedule killed more cells than the 1 and 2 Gy schedules. The results indicate that the size of the shoulder of the survival curve is essential when choosing the most tumoricidal fractionation schedule. (orig.)

Psychosocial influences on prisoner suicide: a case-control study of near-lethal self-harm in women prisoners.

Science.gov (United States)

Marzano, Lisa; Hawton, Keith; Rivlin, Adrienne; Fazel, Seena

2011-03-01

We examined the psychosocial influences on female prisoner suicide by carrying out a study of near-lethal self-harm. We interviewed 60 women prisoners who had recently engaged in near-lethal self-harm (cases) and 60 others who had never carried out near-lethal acts in prison (controls) from all closed female prison establishments in England and Wales, using mixed quantitative and qualitative methods. We gathered information on socio-demographic and criminological variables, life events and childhood trauma, exposure to suicidal behaviour, contributory and precipitating factors for near-lethal self-harm, social support and psychological characteristics. While socio-demographic factors were only modestly associated with near-lethal self-harm, being on remand, in single cell accommodation, and reporting negative experiences of imprisonment were strong correlates. Recent life events and past trauma, including different forms of childhood abuse, were also significantly associated with near-lethal self-harm, as were a family history of suicide and high scores on measures of depression, aggression, impulsivity and hostility, and low levels of self-esteem and social support. Our findings underline the importance of both individual and prison-related factors for suicide in custody, and hence the need for a comprehensive approach to suicide prevention in women's prisons. Given the multiple needs of female prisoners at-risk of self-harm and suicide, complex psychosocial interventions are likely to be required, including interventions for abused and bereaved women, and initiatives to improve staff-prisoner relationships and reduce bullying. The findings of this research may provide insights into factors leading to suicidal behaviour in other forensic and institutional settings, such as detention centres and psychiatric hospitals, and may assist in developing suicide prevention policies for prisoners and other at-risk populations. Copyright © 2011 Elsevier Ltd. All rights

Study of single dose toxic test of Sweet Bee Venom in Beagle Dogs