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Sample records for radiation induced sterility

  1. Radiation sterilization of ketoprofen

    NASA Astrophysics Data System (ADS)

    Katušin-Ražem, Branka; Hamitouche, Katia; Maltar-Strmečki, Nadica; Kos, Karmen; Pucić, Irina; Britvić-Budicin, Smiljana; Ražem, Dušan

    2005-06-01

    Radiation sterilization of ketoprofen (KP) dry powder was investigated by selected physico-chemical methods. High-performance liquid chromatography, ultraviolet spectrophotometry, infrared spectrophotometry, differential scanning calorimetry, X-ray diffraction and electron spin resonance spectroscopy did not show any significant degradation at sterilization dose 25 kGy. To determine the nature, extent and direction of radiation-induced changes, KP was irradiated to extremely high doses, much higher than necessary to achieve sterility. The irradiated KP did not show any difference of XRD patterns up to 200 kGy; with DSC and IR some changes were detected only above 1000 and 2000 kGy, respectively; HPLC has shown about 5% destruction at 2000 kGy. Acetyl benzophenon (AcBph) was generated by irradiation with G(AcBph)=(1.6±0.1)×10 -8 mol J -1. Ames test has shown no mutagenicity of KP irradiated with 3000 kGy or of the oily mixure of radiolytic products isolated from it. Solid KP has proven to be very stable on irradiation, and irradiation has been found to be a suitable method for its sterilization.

  2. Radiation-induced metabolomic changes in sterile male Μοnochamus alternatus (Coleoptera: Cerambycidae).

    PubMed

    Qu, L J; Wang, L J; Zhang, Y A; Wang, Q H; Wang, Y Z; Zhao, T H; Cai, W Z

    2014-01-01

    Radiation-induced sterile insect technique is a biologically based, environment-friendly method for the suppression or eradication of a number of insect pests. Although the basic mechanisms underlying the technology have been well studied, little is known about the cell responses in organisms. Characterization of the metabolic shift associated with radiation exposure in sterile insects would be helpful for understanding the detailed mechanism underlying this technique and promote its practical application. In this article, a metabolomic study was performed to characterize the global metabolic changes induced by radiation using untreated and 40 Gy (60)Coγ-irradiated testes of Japanese pine sawyer, Monochamus alternatus Hope. Differential metabolites were detected and tentatively identified. Many key metabolites in glycolysis and the tricarboxylic acid cycle, as well as most fatty and amino acids, were elevated in irradiated male M. alternatus, presumably resulting from depression of glycolysis and the tricarboxylic acid cycle, each of which are important pathways for energy generation Adenosine Triphosphate (ATP) in insect spermatozoa. The findings in this article will contribute to our knowledge of the characteristic metabolic changes associated with irradiation sterility and understand the molecular mechanisms underlying radiation-induced sterile insect technique.

  3. Auditing radiation sterilization facilities

    NASA Astrophysics Data System (ADS)

    Beck, Jeffrey A.

    The diversity of radiation sterilization systems available today places renewed emphasis on the need for thorough Quality Assurance audits of these facilities. Evaluating compliance with Good Manufacturing Practices is an obvious requirement, but an effective audit must also evaluate installation and performance qualification programs (validation_, and process control and monitoring procedures in detail. The present paper describes general standards that radiation sterilization operations should meet in each of these key areas, and provides basic guidance for conducting QA audits of these facilities.

  4. Radiation-induced sterility for pupal and adult stages of the malaria mosquito Anopheles arabiensis

    PubMed Central

    Helinski, Michelle EH; Parker, Andrew G; Knols, Bart GJ

    2006-01-01

    Background In the context of the Sterile Insect Technique (SIT), radiation-induced sterility in the malaria mosquito Anopheles arabiensis Patton (Diptera: Culicidae) was studied. Male mosquitoes were exposed to gamma rays in the pupal or adult stage and dose-sterility curves were determined. Methods Pupae were irradiated shortly before emergence (at 22–26 hrs of age), and adults <24 hrs post emergence. Doses tested ranged between 0 and 100 Gy. The effects of irradiation on adult emergence, male survival, induced sterility and insemination capability were evaluated. Emergence and insemination data were analysed using independent t-tests against the control. Correlation analyses were performed for insemination rate and dose and insemination and fecundity. Male survival was analysed using Kaplan-Meier survival analyses. Finally, the calculated residual fertility values were inverse-normal transformed and linear regression analyses performed. Results Irradiation of pupae, for all doses tested, had no effect on adult emergence. Survival curves of males irradiated as pupae or adults were similar or even slightly higher than non-irradiated males. Overall, adults appeared to be slightly more susceptible to irradiation, although no significant differences for individual doses were observed. In the pupal stage, a significant negative correlation was found between insemination and dose, but the correlation-coefficient was associated with less than 25% of the total variation. A review of the literature indicated that An. arabiensis is more radiation resistant than other anopheline mosquitoes. Conclusion The optimal dose for male insects to be released in an SIT programme depends on their level of sterility and competitiveness. The use of semi-sterilizing doses to produce more competitive insects is discussed. The most convenient developmental stage for mosquito irradiation on a mass-scale are pupae, but pupal irradiation resulted in a lower insemination rate at the highest

  5. Radiation sterilization of skin allograft

    NASA Astrophysics Data System (ADS)

    Kairiyama, E.; Horak, C.; Spinosa, M.; Pachado, J.; Schwint, O.

    2009-07-01

    In the treatment of burns or accidental loss of skin, cadaveric skin allografts provide an alternative to temporarily cover a wounded area. The skin bank facility is indispensable for burn care. The first human skin bank was established in Argentina in 1989; later, 3 more banks were established. A careful donor selection is carried out according to the national regulation in order to prevent transmissible diseases. As cadaveric human skin is naturally highly contaminated, a final sterilization is necessary to reach a sterility assurance level (SAL) of 10 -6. The sterilization dose for 106 batches of processed human skin was determined on the basis of the Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control (2004) and ISO 11137-2 (2006). They ranged from 17.6 to 33.4 kGy for bioburdens of >10-162.700 CFU/100 cm 2. The presence of Gram negative bacteria was checked for each produced batch. From the analysis of the experimental results, it was observed that the bioburden range was very wide and consequently the estimated sterilization doses too. If this is the case, the determination of a tissue-specific dose per production batch is necessary to achieve a specified requirement of SAL. Otherwise if the dose of 25 kGy is preselected, a standardized method for substantiation of this dose should be done to confirm the radiation sterilization process.

  6. Transgenic technologies to induce sterility.

    PubMed

    Catteruccia, Flaminia; Crisanti, Andrea; Wimmer, Ernst A

    2009-11-16

    The last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT) against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes.

  7. Radiation sterilization of new drug delivery systems

    PubMed Central

    Abuhanoğlu, Gürhan

    2014-01-01

    Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, microemulsion, and liposomal systems, have been sterilized by gamma (γ) and beta (β) rays, and more recently, by e-beam sterilization. In this review, the sterilization of new drug delivery systems was discussed other than conventional drug delivery systems by γ irradiation. PMID:24936306

  8. Radiation sterilization of new drug delivery systems.

    PubMed

    Abuhanoğlu, Gürhan; Ozer, A Yekta

    2014-06-01

    Radiation sterilization has now become a commonly used method for sterilization of several active ingredients in drugs or drug delivery systems containing these substances. In this context, many applications have been performed on the human products that are required to be sterile, as well as on pharmaceutical products prepared to be developed. The new drug delivery systems designed to deliver the medication to the target tissue or organ, such as microspheres, nanospheres, microemulsion, and liposomal systems, have been sterilized by gamma (γ) and beta (β) rays, and more recently, by e-beam sterilization. In this review, the sterilization of new drug delivery systems was discussed other than conventional drug delivery systems by γ irradiation.

  9. Radappertization (Radiation Sterilization) of Foods

    DTIC Science & Technology

    1976-12-01

    Street, Westport, c·r 06880; 1974. S-78-P EVALUATION OF THE TINPLATE CONTAINER FOR PACKAGING OF IRRADIA- TION STERILIZED FOODS. J. J. Killoran, E... TINPLATE CAN FOR PACKAGING OF RADAPPERTIZED BEEF UNDER PRODUCTION CONDITIONS. J. J. Killoran, J. J. Hawker, and E. Wierbicki. 5-12𔄂-P RELIABILITY OF

  10. Radiation sterilization of tissue allografts: A review

    PubMed Central

    Singh, Rita; Singh, Durgeshwer; Singh, Antaryami

    2016-01-01

    Tissue substitutes are required in a number of clinical conditions for treatment of injured and diseased tissues. Tissues like bone, skin, amniotic membrane and soft tissues obtained from human donor can be used for repair or reconstruction of the injured part of the body. Allograft tissues from human donor provide an excellent alternative to autografts. However, major concern with the use of allografts is the risk of infectious disease transmission. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Gamma radiation has several advantages and is the most suitable method for sterilization of biological tissues. This review summarizes the use of gamma irradiation technology as an effective method for sterilization of biological tissues and ensuring safety of tissue allografts. PMID:27158422

  11. Radiation sterilization of tissue allografts: A review.

    PubMed

    Singh, Rita; Singh, Durgeshwer; Singh, Antaryami

    2016-04-28

    Tissue substitutes are required in a number of clinical conditions for treatment of injured and diseased tissues. Tissues like bone, skin, amniotic membrane and soft tissues obtained from human donor can be used for repair or reconstruction of the injured part of the body. Allograft tissues from human donor provide an excellent alternative to autografts. However, major concern with the use of allografts is the risk of infectious disease transmission. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Gamma radiation has several advantages and is the most suitable method for sterilization of biological tissues. This review summarizes the use of gamma irradiation technology as an effective method for sterilization of biological tissues and ensuring safety of tissue allografts.

  12. RADIATION STERILIZATION OF COCOA POWDERS

    DTIC Science & Technology

    treatment on chocolate coatings, cocoa , and chocolate syrup. In all experimentation with gamma radiation, FLAVOR is the critical problem. At dosage...products of high fat content usually show marked changes in flavor. For example: cocoas , milk and bittersweet coatings, and cocoa utter. Inversely, no...off-flavors were detectable in chocolate syrups which have a low fat content. Some resistance to bloom can be achieved but at the loss of other

  13. Sterilization of skin allografts by ionizing radiation.

    PubMed

    Bourroul, Selma Cecília; Herson, Marisa Roma; Pino, Eddy; Matho, Monica Beatriz

    2002-11-01

    The skin has a fundamental role in the viability of human body. In the case of extensive wounds, skin allografts provide an alternative to cover temporarily the damaged areas. After donor screening and preservation in glycerol 85%, the skin can be stored in a Skin Bank. Glycerol at this concentration has a bacteriostatic effect after certain time of preservation. On the other hand, skin sterilization by ionizing radiation may reduce the quarentine period for transplantation in patients. The objective of this work was to evaluate allograft sterilization using two sources of ionizing radiation. Through the analysis of stress-strain, it was intended to verify possible effects of the radiation on the structure of preserved grafts. Three groups of skin samples were selected. The first group was maintained in the initial conditions, not irradiated. The second was exposed to cobalt-60, while the third one was irradiated using an Dynamitron Accelerator JOB188 electron beam. The irradiation dose was 25 kGy for both tests. Both irradiation sources, and the Instron Universal Machine used for biomechanical experiments, are installed at the Centro de Tecnologia das Radiações/Instituto de Pesquisas Energéticas e Nucleares (São Paulo, Brazil). According to the preliminary results, biomechanical characteristics of the samples irradiated seem to be maintained with regard to the non irradiated group.

  14. Radiation Sterilization of Prototype Military Foods

    PubMed Central

    Anellis, Abe; Berkowitz, D.; Jarboe, C.; El-Bisi, H. M.

    1967-01-01

    Ten lots of diced cured ham, packed in cans, were inoculated with approximately 106Clostridium botulinum spores per can. Each lot was seeded with a different strain (five type A and five type B strains). All cans were irradiated to various dose levels with Co60. Evidence provided by swelling, toxicity, and recoverable C. botulinum with 6,350 cans demonstrated that: (i) 4.5 Mrad was more than adequate as a sterilization dose; (ii) the minimal experimental sterilizing dose (ESD) based on nonswollen nontoxic endpoints was 2.0 < ESD ≤ 2.5 Mrad, and based on non-spoiled sterile cans was 3.0 < ESD ≤ 3.5 Mrad (the latter was supported by the computed theoretical 12D dose); (iii) D values calculated from botulinal survival data indicated that, as a group, the type A strains were more radioresistant than type B strains; strains 12885A and 41B, with respective D values of 0.242 and 0.175, represented the most resistant of each type; (iv) swollen cans did not always contain toxin, nor were toxic cans always swollen; (v) viable C. botulinum can exist for 6 months at 30 C without producing visible or toxic spoilage at doses of 3.0 Mrad and lower, including, in some instances, 0.0 Mrad; and (vi) a phenomenon similar to heat activation of spores occurred at sublethal radiation doses. Images Fig. 1 PMID:5340164

  15. Radiation sterilization of enzyme hybrids with biodegradable polymers

    NASA Astrophysics Data System (ADS)

    Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

    2002-03-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate "hybrid" biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of 60Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification.

  16. Radiation treatment for sterilization of packaging materials

    NASA Astrophysics Data System (ADS)

    Haji-Saeid, Mohammad; Sampa, Maria Helena O.; Chmielewski, Andrzej G.

    2007-08-01

    Treatment with gamma and electron radiation is becoming a common process for the sterilization of packages, mostly made of natural or synthetic plastics, used in the aseptic processing of foods and pharmaceuticals. The effect of irradiation on these materials is crucial for packaging engineering to understand the effects of these new treatments. Packaging material may be irradiated either prior to or after filling. The irradiation prior to filling is usually chosen for dairy products, processed food, beverages, pharmaceutical, and medical device industries in the United States, Europe, and Canada. Radiation effects on packaging material properties still need further investigation. This paper summarizes the work done by different groups and discusses recent developments in regulations and testing procedures in the field of packaging technology.

  17. Twenty years of radiation sterilization in Croatia

    NASA Astrophysics Data System (ADS)

    Ražem, Dus̆an

    2004-09-01

    The development of radiation processing in Croatia is described from its inception 20 years ago up to the present time. Annual throughputs of treated materials are given by the categories of materials and pertaining volumes. The pasteurization of hard gelatine capsules occured during the early stages, while sterilization of disposable medical supplies has been dominant in the later stages. Irradiation of foods and of cosmetics and toiletries has been a minor fraction of the total throughput. Since the recovery of everyday life and economy of the country after the war, the total throughput has increased steadily to reach 13,000 m 3 kGy in 2002, 90% of which are medical supplies. Estimates of the present maximum capacity of 30,000 m 3 kGy and of future needs indicate that the present rate of growth could be sustained for the next several years only, unless a major upgrading is undertaken. An estimate of potential future needs is made.

  18. Stabilization of methacrylic polymers against sterilizing radiation

    SciTech Connect

    Keating, P.J.; Roach, D.E.

    1992-04-07

    This patent describes a method for preparing a polymer with improved resistance to sterilizing radiation. It comprises preparing a polymer comprising at least 50% of units derived from one or more alkyl methacrylates and, optionally, units derived from one or more other monomers selected from vinyl or vinylidene monomers; admixing the polymer with from about one-half to about two percent by weight of the monomers of at least one aliphatic alcohol, the alcohol containing up to ten carbon atoms, no ultraviolet stabilizer being present, so as to distribute the alcohol essentially uniformly throughout the polymer, wherein an impact modifier is admixed with the polymer prior to admixing the at least one alcohol.

  19. Sterilizing effects of cobalt-60 and cesium-137 radiation on male sea lampreys

    USGS Publications Warehouse

    Hanson, L.H.

    1990-01-01

    Male spawning-run sea lampreys Petromyzon marinus were exposed to various doses of cobalt-60 or cesium-137 radiation in an attempt to sterilize them for use in a program for controlling sea lampreys through the release of sterile males. Males captured and irradiated during the early part of the upstream migration were not effectively sterilized at the doses tested. After irradiation, the sea lampreys were more susceptible to fungal infections by Saprolegnia sp., and many died without attempting to spawn. Males captured and irradiated during the middle and late parts of the spawning migration were effectively sterilized at a dose of 2,000 rads. However, some radiation-induced mortality was observed in males captured and irradiated during the middle part of the spawning migration. Radiation is not as effective as the chemosterilant bisazir for sterilizing male sea lampreys.

  20. Radiation sterilization of traditional medicine drugs in Vietnam

    NASA Astrophysics Data System (ADS)

    Hang, N. D.; Canh, T. T.; Thuy, T. T.

    1995-02-01

    With the application of Gamma Co-60 radiation sterilization in pharmaceutical industry, attention should be paid to the possibilities of sterilizing traditional medicine drugs produced in Vietnam. In this paper the opinion which traditional medicine drugs can be satisfactorily sterilized by irradiation is based on the changes of physical and chemical properties of the products and microbiological examinations. The sterilizing radiation dose were calculated and the results are the following (in Mrad) Rheumatine-2.2, Hasinh-3.3, snake extract-1.8, Samcotgiao-2.2. The changes of physical and chemical properties of the products and their toxicity after irradiation have been shown to be not over the levels of allowance.

  1. Radiation sterilization of antibiotic liposome formulations: A case study

    NASA Astrophysics Data System (ADS)

    Botelho, M. L.; Cabo Verde, S.; Alves, L.; Belchior, A.; Reymão, J.; Trabulo, S.; Gaspar, M. M.; Cruz, M. E. M.; Simões, S.

    2007-08-01

    New liposome formulations for antimycobacterial purpose are under development in Portugal. The drug must be submitted to a sterilization process. In order to find out if gamma radiation could be applied, microbiological and chemical studies were developed based on ISO standards. The bioburden was determined, the main critical points of line production were detected and the sterilization dose was determined based on a chart control for bioburden. A preliminary maximum acceptable dose for product was found out based on the main functional parameters.

  2. Sterilization of bone allografts by microwave and gamma radiation.

    PubMed

    Singh, Rita; Singh, Durgeshwer

    2012-09-01

    Bone allografts are used to enhance healing in osteotomies, arthrodesis, fractures and to replace bone loss resulting from tumour or trauma. However, a major concern associated with the bone allografts is the potential for disease transmission. Various sterilization techniques have been developed to prevent infection through allografts. This study was undertaken with the aim of exploring the use of microwave radiation for sterilization of bone allografts and to compare with gamma radiation sterilization. Bone allografts were processed from femoral heads obtained from living donors. The effect of microwave and gamma radiation on the bacteria isolated from bone allograft was evaluated. The microwave radiation treatment was performed at 2450 MHz (frequency) for varying lengths of time at maximum power 900 Watts (W). Viability of three Gram-positive bacteria - Bacillus subtilis, Corynebacterium, Staphylococcus aureus and three Gram-negative bacteria - Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa was examined after irradiation of bacterial suspensions and contaminated processed bone allografts. The sterility test of microwave and gamma irradiated bone allograft was carried out in accordance with ISO (International Organization for Standardization) 11737-2. Microwave irradiation (2450 MHz and 900 W) of bacterial isolates resulted in complete inactivation within 60 seconds. The contaminated bone samples showed no growth of organisms after 2 minutes of exposure to microwave irradiation. No viable counts were detected in bone grafts inoculated with Gram-negative bacterial species on gamma irradiation to a dose of 15 kGy. Bones contaminated with Gram-positive bacteria required a higher dose of 20 kGy for complete inactivation. The study shows that sterilization of contaminated femoral head bone allografts can be achieved by short exposure of 2 min to 2450 MHz and 900 W microwave radiation.

  3. Targeted Gene Silencing to Induce Permanent Sterility

    PubMed Central

    Dissen, Gregory A.; Lomniczi, Alejandro; Boudreau, Ryan L.; Chen, Yong Hong; Davidson, Beverly L.; Ojeda, Sergio R.

    2012-01-01

    Contents A nonsurgical method to induce sterility would be a useful tool to control feral populations of animals. Our laboratories have experience with approaches aimed at targeting brain cells in vivo with vehicles that deliver a payload of either inhibitory RNAs or genes intended to correct cellular dysfunction. A combination/modification of these methods may provide a useful framework for the design of approaches that can be used to sterilize cats and dogs. For this approach to succeed it has to meet several conditions: It needs to target a gene essential for fertility. It must involve a method that can selectively silence the gene of interest. It also needs to deliver the silencing agent via a minimally invasive method. Finally, the silencing effect needs to be sustained for many years, so that expansion of the targeted population can be effectively prevented. In this article we discuss this subject and provide a succinct account of our previous experience with: a) molecular reagents able to disrupt reproductive cyclicity when delivered to regions of the brain involved in the control of reproduction, and b) molecular reagents able to ameliorate neuronal disease when delivered systemically using a novel approach of gene therapy. PMID:22827375

  4. Radiation sterilization of medical products in the Philippines

    NASA Astrophysics Data System (ADS)

    Singson, C.; Carmona, C.; de Guzman, Z.; Barrun, W.; Lanuza, L.

    This paper presents the results of a comprehensive investigation of the biological, microbiological, physico-chemical, and dosimetry aspects of using gamma irradiation for the sterilization of locally manufactured medical products and pharmaceuticals. The objective of this study is to determine the technological feasibility of radiation sterilization for the said products in the Philippines. Hence, the materials used were directly obtained from local manufacturers. They are polyvinyl chloride or polyethylene based medical plastic disposables namely: absorbent cotton, surgical gauze, bandage, visceral packs, and some antibiotics and opthalmic ointments. The gamma facility of the Philippine Atomic Energy Commission was used for the irradiation. Result of biological studies indicate no signs of toxicity on experimental mice injected with extracts from irradiated samples. The contaminants are identified as Pseudomonas Sp. Staphyloccocus Aureus and Bacillus Subtilis. The D 10 values of survivors of higher doses ranged below 0.235 Megarad suggesting that these contaminants can be eliminated by the generally used sterilizing dose of 2.5 Mrads. The physico-chemical tests did not indicate any significant degradation of the irradiated products. Opthalmic and topical antibiotic ointments showed no marked decrease in potency. Fading tests on dosimeters used showed that red perspex is a more efficient dosimeter than clear perspex when irradiation time is prolonged. These studies indicated that radiation sterilization is technically feasible for locally manufactured medical products.

  5. Radiation sterilization and identification of gizzard slices

    NASA Astrophysics Data System (ADS)

    Zhu, S.; Fu, C.; Jiang, W.; Yao, D.; Zhao, K.; Zhang, Y.

    1998-06-01

    An orthogonal test of 4 factors of radiation dose, storage temperature, storage time, and sanitation of cutting places was carried out to optimize the conditions for disinfection of gizzard slices. In the optimized condition, both the sanitary quality and the shelf-life of gizzard slices were improved. To identify irradiated gizzard slices, the sensory change, and the levels of water-soluble nitrogen, amino acid, total volatile basic nitrogen, peroxide value, vitamin C consumption and KMnO 4 consumption were determinated. No significant change was observed except for the color which was light brown on the surface of irradiated slices.

  6. X-ray-induced sterility in Aedes albopictus (Diptera: Culicidae) and male longevity following irradiation.

    PubMed

    Yamada, H; Parker, A G; Oliva, C F; Balestrino, F; Gilles, J R L

    2014-07-01

    The mosquito Aedes albopictus (Skuse, 1895) is a potent vector of several arboviral diseases, most notably chikungunya and dengue fever. In the context of the sterile insect technique (SIT), the sterilization of the male mosquitoes before their release can be achieved by gamma-ray irradiation. As gamma-ray irradiators are becoming increasingly problematic to purchase and transport, the suitability of an X-ray irradiator as an alternative for the sterilization of Ae. albopictus males was studied. The sterilization of up to 200,000 pupae at one time can be achieved with relative ease, and the sterility results obtained were comparable with those achieved by gamma irradiation, where 99% sterility is induced with a dose of 40 Gy. A significant reduction of longevity was observed in the latter stages of the males' life after irradiation treatments, especially at doses > 40 Gy, which is consistent with the negative effects on longevity induced by similar radiation doses using gamma rays. Females irradiated at 40 Gy were not only 100% sterile, but also failed to oviposit entirely, i.e., all of the females laid 0 eggs. Overall, it was found that the X-ray irradiator is generally suitable for the sterilization process for sterile insect technique programs, as it showed a high processing capacity, practicality, high effectiveness, and reproducibility.

  7. Sterilization.

    PubMed

    Peterson, Herbert B

    2008-01-01

    Worldwide, sterilization (tubal sterilization and vasectomy) is used by more people than any other method of contraception. All techniques of tubal sterilization in widespread use in the United States have low risks of surgical complications. Although tubal sterilization is highly effective, the risk of pregnancy varies by age and method of occlusion. Pregnancies can occur many years after the procedure, and when they do, the risk of ectopic gestation is high. There is now strong evidence against the existence of a post-tubal ligation syndrome of menstrual abnormalities. Although women who have undergone tubal sterilization are more likely than other women to undergo hysterectomy subsequently, there is no known biologic basis for this relationship. Although sterilization is intended to be permanent, expressions of regret and requests for reversal are not uncommon and are much more likely to occur among women sterilized at young ages. Tubal sterilization has little or no effect on sexual function for most women. Vasectomy is less likely than tubal sterilization to result in serious complications. Minor complications, however, are not uncommon. Vasectomy does not increase the risk of heart disease, and available evidence argues against an increase in the risk of prostate cancer, testicular cancer, or overall mortality. Whether a postvasectomy pain syndrome exists remains controversial. Although the long-term effectiveness of vasectomy is less well-studied than that for tubal sterilization, it seems likely to be at least as effective. Intrauterine devices and progestin implants are long-acting, highly effective alternatives to sterilization.

  8. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    NASA Astrophysics Data System (ADS)

    Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

    2007-11-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  9. A study on radiation sterilization of medical devices in the South of China

    NASA Astrophysics Data System (ADS)

    Zhutang, Wen; Riyou, Lou; Meilan, Li; Xueqin, Liu; Najie, Lin; Mingsheng, Zeng

    1993-10-01

    In this paper, directing at the peculiarity of south China, the technique and quality control of Co-80 r radiation sterilization of medical devices have been studied. Radiation dose setting is determined by the AAMI method. Experiment shows that radiation treatment has no effect upon the attributes of the products. Under the same condition of packing and environment, storing time of radiation sterilization is 4 times than that of sterilization by heat. Clinical appliances of 1000 carton products show that radiation sterilization products are safe and reliable.

  10. Sterilization using a microwave-induced argon plasma system at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Park, Bong Joo; Lee, D. H.; Park, J.-C.; Lee, I.-S.; Lee, K.-Y.; Hyun, S. O.; Chun, M.-S.; Chung, K.-H.

    2003-11-01

    The use of microwave plasma for sterilization is relatively new. The advantages of this method are the relatively low temperature, time-savings and its nontoxic nature, in contrast to traditional methods such as heat and gas treatment, and radiation. This study investigated the sterilization effects of microwave-induced argon plasma at atmospheric pressure on materials contaminated with various microorganisms, such as bacteria and fungi. A low-cost and reliable 2.45 GHz, waveguide-based applicator was designed to generate microwave plasma at atmospheric pressure. This system consisted of a 1 kW magnetron power supply, a WR-284 copper waveguide, an applicator including a tuning section, and a nozzle section. Six bacterial and fungal strains were used for the sterilization test. The results showed that regardless of the strain, all the bacteria used in this study were fully sterilized within 20 seconds and all the fungi were sterilized within 1 second. These results show that this sterilization method is easy to use, requires significantly less time than the other traditional methods and established plasma sterilization methods, and it is nontoxic. It can be used in the field of sterilization in medical and dental clinics as well as in laboratory settings.

  11. Radiation Sterilization of Prototype Military Foods. III. Pork Loin

    PubMed Central

    Anellis, Abe; Berkowitz, D.; Jarboe, C.; El-Bisi, H. M.

    1969-01-01

    Ten lots of pork loin, packed in cans, were inoculated with approximately 106Clostridium botulinum spores per can. Each lot was seeded with a different strain; five type A and five type B strains were used. The pack comprised 5,690 cans, including controls, and contained about 109 spores per dose. The cans were irradiated with Co60 in the range of 0 to 5.0 Mrad (0.5 Mrad increments) at 5 to 25 C, incubated for 6 months at 30 C, and examined for swelling, toxicity, and recoverable C. botulinum. The minimal experimental sterilizing dose (ESD) based on nonswollen, nontoxic, but nonsterile end points was 2.5 < ESD ≤ 3.0 Mrad, and based on non-spoiled sterile cans was 3.5 < ESD ≤ 4.0 Mrad. The theoretical minimal radiation dose (MRD), the 12D equivalent, varied with the method of computation: 4.74, 4.33 ± 0.17, and 4.19 to 4.99 Mrad were obtained by the Weibull, Spearman-K̈arber, and Schmidt-Nank techniques, respectively. Calculation of D and MRD values by the conventional Schmidt-Nank method produced increasing values with rising dosage; this finding was compared with the data derived by the other two methods of calculation. Suggestions for estimating the MRD of a prototype radiation process are offered. PMID:4905038

  12. Radiation sterilization of prototype military foods. 3. Pork loin.

    PubMed

    Anellis, A; Berkowitz, D; Jarboe, C; el-Bisi, H M

    1969-10-01

    Ten lots of pork loin, packed in cans, were inoculated with approximately 10(6)Clostridium botulinum spores per can. Each lot was seeded with a different strain; five type A and five type B strains were used. The pack comprised 5,690 cans, including controls, and contained about 10(9) spores per dose. The cans were irradiated with Co(60) in the range of 0 to 5.0 Mrad (0.5 Mrad increments) at 5 to 25 C, incubated for 6 months at 30 C, and examined for swelling, toxicity, and recoverable C. botulinum. The minimal experimental sterilizing dose (ESD) based on nonswollen, nontoxic, but nonsterile end points was 2.5 < ESD sterile cans was 3.5 < ESD radiation dose (MRD), the 12D equivalent, varied with the method of computation: 4.74, 4.33 +/- 0.17, and 4.19 to 4.99 Mrad were obtained by the Weibull, Spearman-Karber, and Schmidt-Nank techniques, respectively. Calculation of D and MRD values by the conventional Schmidt-Nank method produced increasing values with rising dosage; this finding was compared with the data derived by the other two methods of calculation. Suggestions for estimating the MRD of a prototype radiation process are offered.

  13. Physical and biological characterization of a seawater ultraviolet radiation sterilizer

    NASA Astrophysics Data System (ADS)

    Torrentera, Laura; Uribe, Roberto M.; Rodríguez, Romana R.; Carrillo, Ricardo E.

    1994-03-01

    The physical and biological characterization of a seawater ultraviolet (UV) sterilizer is described. The physical characterization was performed using radiochromic dye films by evaluating the uniformity of the radiant exposure along each lamp, the effect of the radiation from one lamp on the array of adjacent lamps, and by measuring the UV radiation absorption of seawater with respect to distilled water. The biological characterization was performed by measuring the amount of reduction of bacteria in stored seawater after different filtration and UV treatments. Among the filtration methods tested, differential filtration (5, 3 and 0.45 μm filters connected in series) caused the highest bacterial reduction factor of 60%. UV radiant exposures of 212, 424, 636 and 848 J m -2 yielded bacteria reduction factors of 99.86, 99.969, 99.997 and 100%, respectively, for populations of Vibrio and Pseudomonas bacteria present in stored seawater. It is concluded that the system is useful for water disinfection when 1, 2 or 3 lamps are on; when 4 lamps are used the treated water becomes sterile.

  14. Surgical sterilization: an underutilized procedure for evaluating the merits of induced sterility

    USGS Publications Warehouse

    Kennelly, James J.; Converse, Kathryn A.

    1993-01-01

    Despite more than 4 decades of effort, development of effective wildlife damage control programs based on sterilization of target species has met with limited success. This is partly due to the fact that investigators have assumed, rather than empirically tested, whether the reproductive strategies of the target populations were vulnerable to the planned treatment. Equally important, methods selected to include sterility usually involve a chemical agent that can affect sociosexual behaviors of the nuisance population. In this report, we illustrate how surgically induced sterility circumvents both problems--how the concept without the potentially confounding secondary effects of a chemical. We assessed the merits of initiating research to develop a male chemosterilant for Norway rats, red-winged blackbirds, beaver, and Canada geese by inducing sterility surgically. The infidelity of many red-winged females to their polygynous territorial male was surprising and argued against searching for a male sterilant. On the other hand, beaver and Canada goose studies confirmed previous reports that both form par-bonds and are monogamous. Both should be vulnerable to a male chemosterilant approach, and research toward this goal is justified.

  15. The feasibility of gamma radiation sterilization for decellularized tracheal grafts.

    PubMed

    Johnson, Christopher M; Guo, DeHuang; Ryals, Stephanie; Postma, Gregory N; Weinberger, Paul M

    2017-08-01

    The most promising stem cell-derived tracheal transplantation approach is dependent upon the use of decellularized tracheal grafts. It has been assumed that a sterilization step, such as gamma radiation, would damage the delicate extracellular matrix of the graft, thus rendering it less viable for cellular repopulation, although this has not been thoroughly investigated. Laboratory-based comparative analysis. Fifteen murine tracheas of strain C57/B-6 mice were obtained. Thirteen were subjected to a detergent-enzymatic decellularization process. Of these decellularized tracheas (DT), eight were irradiated, exposing five tracheas to a radiation level of 25 kGy (DT25) and three to 5 kGy (DT5). Two were left untreated. The two untreated tracheas, two DTs, and two DT25s were prepared and examined using both scanning and transmission electron microscopy. Bioburden calculations were obtained from three DTs, three DT25s, and three DT5s by homogenization, serial dilution, and streak plating. Electron microscopy of untreated fresh tracheas and DTs showed a slight qualitative degradation of cartilage ultrastructure due to the decellularization process. In contrast, examination of DT25 shows significant degradation including poor overall preservation of cartilage architecture with disorganized collagen fibers. The nonirradiated DTs had a calculated bacterial bioburden of 7.8 × 10(7) to 3.4 × 10(8) colony-forming units per gram. Both the DT25 and DT5 specimens were found to have a bioburden of zero. Gamma radiation at 25 kGy degrades the architecture of decellularized tracheal grafts. These ultrastructural changes may prove detrimental to graft viability; however, bioburden calculations suggest that a 5 kGy radiation dose may be sufficient for sterilization. NA Laryngoscope, 127:E258-E264, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  16. [Treatment of anovulatory cycle induced sterility].

    PubMed

    Botella Llusia, J

    1983-03-01

    Of all the clinical aspects of human sterility, the anovulatory cycle is undoubtedly 1 that has produced the widest range of therapuetic successes. While in other fields progress has been very slow (male sterility or tubal obstruction), ovarian pharmacoendocrinology has shown several advances over recent years. This progress is due partly to new chemicals such as urinary menopausal gonadotropins, LH-RH, and their analogues Clomiphene and Bromocriptine. Contributing further to these good results is a greater knowledge of the etiology of anovulation and a more accurate selection of cases for treatment.

  17. Sterilization.

    PubMed

    Rioux, M H

    1979-05-01

    The history of sterilization in North America has included enactment of laws in 37 U. S. states and 2 Canadian provinces allowing the procedure to be performed to eliminate undesirable, genetically-transmitted traits. These eugenic laws applied to any of the following categories of persons: mentally regarded, mentally ill, epileptic, criminal, alcoholic, or poor people. Pressure from geneticists, lawyers, and others concerned with the implications of such laws, led to their repeal in many places. Noneugenic and nontherapeutic sterilization is today a recognized medical practice. Legally, such procedures must meet the following criteria: 1) informed consent; 2) individual benefit; and 3) performance with reasonable care and skill. If these criteria are met, doctors are protected from legal liability. The most legal, social, and ethical ambiguities arise in cases where nontherapeutic sterilization is performed on individuals unable to give consent, e.g., minors or mentally handicapped persons.

  18. Ultraviolet radiation for the sterilization of contact lenses

    SciTech Connect

    Gritz, D.C.; Lee, T.Y.; McDonnell, P.J.; Shih, K.; Baron, N. )

    1990-10-01

    Two sources of ultraviolet (UV) radiation with peak wavelengths in the UV-C or UV-B ranges were compared for their ability to sterilize contact lenses infected with Pseudomonas aeruginosa, Streptococcus pneumoniae, Acanthamoeba castellani, Candida albicans, and Aspergillus niger. Also examined was the effect of prolonged UV light exposure on soft and rigid gas permeable (RGP) contact lenses. The UV-C lamp (253.7 nm, 250 mW/cm2 at 1 cm) was germicidal for all organisms within 20 minutes but caused destruction of the soft lens polymers within 6 hours of cumulative exposure. UV-C caused damage to RGP lenses in less than 100 hours. The UV-B lamp (290-310 nm, 500 mW/cm2 at 1 cm) was germicidal for all organisms tested (except Aspergillus) with a 180-minute exposure and caused less severe changes in the soft lens polymers than did the UV-C lamp, although cumulative exposure of 300 hours did substantially weaken the soft lens material. RGP materials were minimally affected by exposure to 300 hours of UV-B. Ultraviolet light is an effective germicidal agent but is injurious to soft lens polymers; its possible utility in the sterilization of RGP lenses and lens cases deserves further study.

  19. Automated technological radiation installation for sterilization of medical goods

    NASA Astrophysics Data System (ADS)

    Auslender, V. L.; Bryazgin, A. A.; Voronin, L. A.; Polyakov, V. A.; Grodetskiy, V. P.; Izhboldin, I. K.; Mirsaetov, O. M.; Petrov, A. M.; Obidin, Yu. T.; Ponomaryov, V. N.

    1998-06-01

    Last years most of the developed countries are using radiation method based on electron accelerators for sterilization of medical goods as mostly safe and ecologically pure from all known methods. The report describes in details the automated installation for sterilization of single-use syringes working in the city of Izhevsk, Russia. The syringes are irradiated from two sides inside the packs containing 250 units each. The packs are automatically turned on the inclined part of the conveyor under influence of their own weight. The syringes are posed vertically along the beam fall. The ration of maximal absorbed dose to minimal is 1.4. The productive rate of installation is no less 100 000 syringes per hour. The installation is based on the linear pulse electron accelerator ILU-6. It is the single cavity machine with electron energy up to 2.5 MeV and average beam power up to 20 kW. The pulse nature of the current and automatic control system permit to vary the absorbed dose in great range. The electron energy, beam current, pulse repetition rate, beam position in the extracted window and transportation of the treated products are computer controlled.

  20. Reducing the radiation sterilization dose improves mechanical and biological quality while retaining sterility assurance levels of bone allografts.

    PubMed

    Nguyen, Huynh; Cassady, Alan I; Bennett, Michael B; Gineyts, Evelyne; Wu, Andy; Morgan, David A F; Forwood, Mark R

    2013-11-01

    Bone allografts carry a risk of infection, so terminal sterilization by gamma irradiation at 25kGy is recommended; but is deleterious to bone quality. Contemporary bone banking significantly reduces initial allograft bioburden, questioning the need to sterilize at 25kGy. We inoculated allograft bone with Staphylococcus epidermidis and Bacillus pumilus, then exposed them to gamma irradiation at 0, 5, 10, 15, 20 and 25kGy. Mechanical and biological properties of allografts were also assessed. Our aim was to determine an optimal dose that achieves sterility assurance while minimizing deleterious effects on allograft tissue. 20-25kGy eliminated both organisms at concentrations from 10(1) to 10(3)CFU, while 10-15kGy sterilized bone samples to a bioburden concentration of 10(2)CFU. Irradiation did not generate pro-inflammatory bone surfaces, as evidenced by macrophage activation, nor did it affect attachment or proliferation of osteoblasts. At doses ≥10kGy, the toughness of cortical bone was reduced (P<0.05), and attachment and fusion of osteoclasts onto irradiated bone declined at 20 and 25kGy (P<0.05). There was no change in collagen cross-links, but a significant dose-response increase in denatured collagen (P<0.05). Our mechanical and cell biological data converge on 15kGy as a threshold for radiation sterilization of bone allografts. Between 5 and 15kGy, bone banks can undertake validation that provides allografts with an acceptable sterility assurance level, improving their strength and biocompatibility significantly. The application of radiation sterilization doses between 5 and 15kGy will improve bone allograft mechanical performance and promote integration, while retaining sterility assurance levels. Improved quality of allograft bone will promote superior clinical outcomes. © 2013.

  1. Radiation sterilization of medical devices. Effects of ionizing radiation on ultra-high molecular-weight polyethylene

    NASA Astrophysics Data System (ADS)

    Buchalla, R.; Schüttler, C.; Bögl, K. W.

    1995-02-01

    Sterilization by ionizing radiation has become, next to ethylene oxide treament, the most important "cold" sterilization process for medical devices made from plastics. The effects of ionizing radiation on the most important polymer for medical devices, ultra-high molecular-weight polyethylene, are briefly described in this review.

  2. Degradation of Biochemical Activity in Soil Sterilized by Dry Heat and Gamma Radiation

    NASA Technical Reports Server (NTRS)

    Shih, K. L.; Souza, K. A.

    1978-01-01

    The effect of soil sterilization by dry heat (0.08% relative humidity), gamma radiation, or both on soil phosphatase, urease, and decarboxylase activity was studied. Soil sterilized by a long exposure to dry heat at relatively low temperatures (eight weeks at 100.5 C) retained higher activities than did soil exposed to a higher temperature (two weeks at 124.5 C), while all activity was destroyed by four days at 148.5 C. Sterilization with 7.5 Mrads destroyed less activity than did heat sterilization. The effect of several individually nonsterizing doses of heat radiation is described.

  3. Degradation of Biochemical Activity in Soil Sterilized by Dry Heat and Gamma Radiation

    NASA Technical Reports Server (NTRS)

    Shih, K. L.; Souza, K. A.

    1978-01-01

    The effect of soil sterilization by dry heat (0.08% relative humidity), gamma radiation, or both on soil phosphatase, urease, and decarboxylase activity was studied. Soil sterilized by a long exposure to dry heat at relatively low temperatures (eight weeks at 100.5 C) retained higher activities than did soil exposed to a higher temperature (two weeks at 124.5 C), while all activity was destroyed by four days at 148.5 C. Sterilization with 7.5 Mrads destroyed less activity than did heat sterilization. The effect of several individually nonsterizing doses of heat radiation is described.

  4. Chemical analysis applied to the radiation sterilization of solid ketoprofen

    NASA Astrophysics Data System (ADS)

    Colak, S.; Maquille, A.; Tilquin, B.

    2006-01-01

    The aim of this work is to investigate the feasibility of radiation sterilization of ketoprofen from a chemical point of view. Although irradiated ketoprofen has already been studied in the literature [Katusin-Razem et al., Radiat. Phys. Chem. 73 111-116 (2005)], new results, on the basis of electron spin resonance (ESR) measurements and the use of hyphenated techniques (GC-MS and LC-MS), are obtained. The ESR spectra of irradiated ketoprofen consists of four unresolved resonance peaks and the mean G-value of ketoprofen is found to be 4 +/- 0.9 nmoles/J, which is very small. HPLC-UV analyses indicate that no significant loss of ketoprofen is detected after irradiation. LC-MS-MS analyses show that the structures of the non-volatile final products are similar to ketoprofen. Benzaldehyde is detected in the irradiated samples after dynamic-extraction GC-MS. The analyses show that ketoprofen is radioresistant and therefore might be radiosterilized.

  5. Radiation chemistry of amino acids, peptides and proteins in relation to the radiation sterilization of high-protein foods

    SciTech Connect

    Garrison, W. M.

    1981-12-01

    An important source of information on the question of whether or not toxic or other deleterious substances are formed in the radiation sterilization of foods is the chemical study of reaction products and reaction mechanisms in the radiolysis of individual food components. The present evaluation of the radiation chemistry of amino acids, peptides, and proteins outlines the various radiation-induced processes which lead to amino acid degradation and to the synthesis of amino acid derivatives of higher molecular weight. Among the latter are the ..cap alpha..,..cap alpha..'-diamino dicarboxylic acids which are formed as major products in the radiolysis of peptides both in aqueous solution and in the solid state. The ..cap alpha..,..cap alpha..'-diamino acids are of particular interest as irradiation products because they represent a class of compounds not normally encountered in plant and animal protein sources. Such compounds have, however, been isolated from certain types of bacteria and bacterial products. All of the available data strongly suggest that the ..cap alpha..,..cap alpha..'-diamino acids are produced in significant yield in the radiation sterilization of high protein foods. The importance of initiating extensive chemical and biological studies of these and of other high molecular weight products in irradiated food is emphasized.

  6. [Radiation sterilization of units of a Mars descent module--a miniature meteorological station].

    PubMed

    Paramonov, D V; Trofimov, V I; Aleksashkin, S N; Khamidullina, N M; Novikova, N D; Deshevaia, E A; Polikarpov, N A

    2010-01-01

    Subject of the test was a procedure of electron sterilization of Mars descent module units. As a result, data on distribution of absorbed dose field across the surface and by the entire volume of the mockup of a miniature meteorological station (MMS) were obtained In addition, electron sterilization technology was developed and the range of absorbed dose from electron radiation that will sterilize reliably packaged MMS hardware were defined in the interval from 30 to 40 kGy.

  7. Radiation and ethylene oxide terminal sterilization experiences with drug eluting stent products.

    PubMed

    Lambert, Byron J; Mendelson, Todd A; Craven, Michael D

    2011-12-01

    Radiation and ethylene oxide terminal sterilization are the two most frequently used processes in the medical device industry to render product within the final sterile barrier package free from viable microorganisms. They are efficacious, safe, and efficient approaches to the manufacture of sterile product. Terminal sterilization is routinely applied to a wide variety of commodity healthcare products (drapes, gowns, etc.) and implantable medical devices (bare metal stents, heart valves, vessel closure devices, etc.) along with products used during implantation procedures (catheters, guidewires, etc.). Terminal sterilization is also routinely used for processing combination products where devices, drugs, and/or biologics are combined on a single product. High patient safety, robust standards, routine process controls, and low-cost manufacturing are appealing aspects of terminal sterilization. As the field of combination products continues to expand and evolve, opportunity exists to expand the application of terminal sterilization to new combination products. Material compatibility challenges must be overcome to realize these opportunities. This article introduces the reader to terminal sterilization concepts, technologies, and the related standards that span different industries (pharmaceutical, medical device, biopharmaceuticals, etc.) and provides guidance on the application of these technologies. Guidance and examples of the application of terminal sterilization are discussed using experiences with drug eluting stents and bioresorbable vascular restoration devices. The examples provide insight into selecting the sterilization method, developing the process around it, and finally qualifying/validating the product in preparation for regulatory approval and commercialization. Future activities, including new sterilization technologies, are briefly discussed.

  8. Ultraviolet Radiation in Wound Care: Sterilization and Stimulation

    PubMed Central

    Gupta, Asheesh; Avci, Pinar; Dai, Tianhong; Huang, Ying-Ying; Hamblin, Michael R.

    2013-01-01

    Significance Wound care is an important area of medicine considering the increasing age of the population who may have diverse comorbidities. Light-based technology comprises a varied set of modalities of increasing relevance to wound care. While low-level laser (or light) therapy and photodynamic therapy both have wide applications in wound care, this review will concentrate on the use of ultraviolet (UV) radiation. Recent Advances UVC (200–280 nm) is highly antimicrobial and can be directly applied to acute wound infections to kill pathogens without unacceptable damage to host tissue. UVC is already widely applied for sterilization of inanimate objects. UVB (280–315 nm) has been directly applied to the wounded tissue to stimulate wound healing, and has been widely used as extracorporeal UV radiation of blood to stimulate the immune system. UVA (315–400 nm) has distinct effects on cell signaling, but has not yet been widely applied to wound care. Critical Issues Penetration of UV light into tissue is limited and optical technology may be employed to extend this limit. UVC and UVB can damage DNA in host cells and this risk must be balanced against beneficial effects. Chronic exposure to UV can be carcinogenic and this must be considered in planning treatments. Future Directions New high-technology UV sources, such as light-emitting diodes, lasers, and microwave-generated UV plasma are becoming available for biomedical applications. Further study of cellular signaling that occurs after UV exposure of tissue will allow the benefits in wound healing to be better defined. PMID:24527357

  9. BASICS OF STERILE COMPOUNDING: Sterilization Methods in Sterile Product Manufacturing.

    PubMed

    Akers, Michael J

    2015-01-01

    Sterilization methods to produce sterile preparations include heat, gas, radiation, and filtration. This article focuses on heat, gas, and radiation sterilization, plus a brief introduction to bright-light sterilization. Microbiology basics and microbial death kinetics, key to understanding why these sterilization methods work, will also be briefly discussed. Filtration sterilization will be covered in a separate article.

  10. Gamma Radiation Sterilization Reduces the High-cycle Fatigue Life of Allograft Bone.

    PubMed

    Islam, Anowarul; Chapin, Katherine; Moore, Emily; Ford, Joel; Rimnac, Clare; Akkus, Ozan

    2016-03-01

    Sterilization by gamma radiation impairs the mechanical properties of bone allografts. Previous work related to radiation-induced embrittlement of bone tissue has been limited mostly to monotonic testing which does not necessarily predict the high-cycle fatigue life of allografts in vivo. We designed a custom rotating-bending fatigue device to answer the following questions: (1) Does gamma radiation sterilization affect the high-cycle fatigue behavior of cortical bone; and (2) how does the fatigue life change with cyclic stress level? The high-cycle fatigue behavior of human cortical bone specimens was examined at stress levels related to physiologic levels using a custom-designed rotating-bending fatigue device. Test specimens were distributed among two treatment groups (n = 6/group); control and irradiated. Samples were tested until failure at stress levels of 25, 35, and 45 MPa. At 25 MPa, 83% of control samples survived 30 million cycles (run-out) whereas 83% of irradiated samples survived only 0.5 million cycles. At 35 MPa, irradiated samples showed an approximately 19-fold reduction in fatigue life compared with control samples (12.2 × 10(6) ± 12.3 × 10(6) versus 6.38 × 10(5) ± 6.81 × 10(5); p = 0.046), and in the case of 45 MPa, this reduction was approximately 17.5-fold (7.31 × 10(5) ± 6.39 × 10(5) versus 4.17 × 10(4) ± 1.91 × 10(4); p = 0.025). Equations to estimate high-cycle fatigue life of irradiated and control cortical bone allograft at a certain stress level were derived. Gamma radiation sterilization severely impairs the high cycle fatigue life of structural allograft bone tissues, more so than the decline that has been reported for monotonic mechanical properties. Therefore, clinicians need to be conservative in the expectation of the fatigue life of structural allograft bone tissues. Methods to preserve the fatigue strength of nonirradiated allograft bone tissue are needed. As opposed to what monotonic tests might suggest, the cyclic

  11. Review and state of the art on radiation sterilization of medical devices

    NASA Astrophysics Data System (ADS)

    Dorpema, J. W.

    Review and state of art of radiation sterilization Radiation as a sterilization method was designed in the years 1950-1960. The decade afterwards the application for sterilization of medical products and devices was developped. Extensive studies performed on both the physical, chemical and (micro) biological aspects revealed the requirements for safety and efficacy. These efforts were highly stimulated by the IAEA and resulted in a elegant sterilization method. In product manufacturing, where sterilization represents a final step in the production sequence, radiation has eversince reached its widest application in the field of medical devices. As a spin off it initiated new ideas and approaches towards sterilization in general. Consequently sterility was redefined in terms of a probabilistic concept (10-6) and the bioburden determination method was introduced as a tool for both quality control and potential instrument for dose setting. However these refinements also created controversies, whereby the dose requirements became divided for Europe and North America. Moreover studies recently performed in Europe suggest even a further extension of this opinion gap. Detailed studies, on the clinical effects of low dose treated products (12.5 - 17.5 kGy) are needed to counterbalance the dose suggestions extracted from statistically based dose determinations (> 28 kGy ) and the microbiological resistance determinations ( > 28 - 30 kGy). Dose setting based on risk classification could be considered for distinct product categories. In the mean time a general acceptance of the originally, in the early seventhies, established minimum dose of 25 kGy would seem a reasonable compromise. As the interest for radiation sterilization as the favourable, non polluting and simple method is increasing rapidly over the last five years, both gamma- and beta driven sterilization plants will be needed. Harmonization on sterilization dose therfore requires high priority.

  12. Sterilization by gamma radiation of antibiotic impregnated polymethylmethacrylate and plaster of Paris beads. A pilot study.

    PubMed

    Trencart, P; Elce, Y A; Rodriguez Batista, E; Michaud, G

    2014-01-01

    Ethylene oxide is currently recommended for sterilization of antibiotic impregnated beads; however this method carries health risks to personnel and is becoming less available. To perform a pilot study of the effect of radiation for sterilization of polymethylmethacrylate (PMMA) and plaster of Paris (POP) beads impregnated with amikacin, enrofloxacin, and ceftiofur. Radiation would effectively sterilize the beads without affecting the efficacy of the antibiotic. Beads of PMMA and POP were prepared in a clean but non-sterile manner with one of the three antibiotics (amikacin, enrofloxacin, ceftiofur) or no antibiotic. Beads were then exposed to radiation for a total dose of 0 kiloGray (kGy), 10 kGy and 25 kGy. Beads were incubated on Mueller-Hinton agar plates seeded with Escherichia coli, Staphylococcus aureus or Pseudomonas aeruginosa for 24 hours or cultured in brain-heart infusion broth for 48 hours. Zones of inhibition were measured on the agar plates and statistics were performed on the diameters of the zones of inhibition using an analysis of variance. There were no differences in the diameters of inhibition for all levels of radiation for all PMMA beads. The same was true with POP beads with the exception of enrofloxacin which had a significantly decreased zone of inhibition with increased levels of radiation, though the clinical significance of this finding was not assessed. Only beads without antibiotics and not exposed to radiation had bacterial growth. Radiation may be an effective method of sterilization for antibiotic impregnated beads.

  13. Dark radiation sterile neutrino candidates after Planck data

    SciTech Connect

    Valentino, Eleonora Di; Melchiorri, Alessandro; Mena, Olga E-mail: alessandro.melchiorri@roma1.infn.it

    2013-11-01

    Recent Cosmic Microwave Background (CMB) results from the Planck satellite, combined with previous CMB data and Hubble constant measurements from the Hubble Space Telescope, provide a constraint on the effective number of relativistic degrees of freedom 3.62{sup +0.50}{sub −0.48} at 95% CL. New Planck data provide a unique opportunity to place limits on models containing relativistic species at the decoupling epoch. We present here the bounds on sterile neutrino models combining Planck data with galaxy clustering information. Assuming N{sub eff} active plus sterile massive neutrino species, in the case of a Planck+WP+HighL+HST analysis we find m{sub ν,} {sub sterile}{sup eff} < 0.36 eV and 3.14 < N{sub eff} < 4.15 at 95% CL, while using Planck+WP+HighL data in combination with the full shape of the galaxy power spectrum from the Baryon Oscillation Spectroscopic Survey BOSS Data Relase 9 measurements, we find that 3.30 < N{sub eff} < 4.43 and m{sub ν,} {sub sterile}{sup eff} < 0.33 eV both at 95% CL with the three active neutrinos having the minimum mass allowed in the normal hierarchy scheme, i.e. ∑m{sub ν} ∼ 0.06 eV. These values compromise the viability of the (3+2) massive sterile neutrino models for the parameter region indicated by global fits of neutrino oscillation data. Within the (3+1) massive sterile neutrino scenario, we find m{sub ν,} {sub sterile}{sup eff} < 0.34 eV at 95% CL. While the existence of one extra sterile massive neutrino state is compatible with current oscillation data, the values for the sterile neutrino mass preferred by oscillation analyses are significantly higher than the current cosmological bound. We review as well the bounds on extended dark sectors with additional light species based on the latest Planck CMB observations.

  14. Dark radiation sterile neutrino candidates after Planck data

    NASA Astrophysics Data System (ADS)

    Di Valentino, Eleonora; Melchiorri, Alessandro; Mena, Olga

    2013-11-01

    Recent Cosmic Microwave Background (CMB) results from the Planck satellite, combined with previous CMB data and Hubble constant measurements from the Hubble Space Telescope, provide a constraint on the effective number of relativistic degrees of freedom 3.62+0.50-0.48 at 95% CL. New Planck data provide a unique opportunity to place limits on models containing relativistic species at the decoupling epoch. We present here the bounds on sterile neutrino models combining Planck data with galaxy clustering information. Assuming Neff active plus sterile massive neutrino species, in the case of a Planck+WP+HighL+HST analysis we find mν, sterileeff < 0.36 eV and 3.14 < Neff < 4.15 at 95% CL, while using Planck+WP+HighL data in combination with the full shape of the galaxy power spectrum from the Baryon Oscillation Spectroscopic Survey BOSS Data Relase 9 measurements, we find that 3.30 < Neff < 4.43 and mν, sterileeff < 0.33 eV both at 95% CL with the three active neutrinos having the minimum mass allowed in the normal hierarchy scheme, i.e. ∑mν ~ 0.06 eV. These values compromise the viability of the (3+2) massive sterile neutrino models for the parameter region indicated by global fits of neutrino oscillation data. Within the (3+1) massive sterile neutrino scenario, we find mν, sterileeff < 0.34 eV at 95% CL. While the existence of one extra sterile massive neutrino state is compatible with current oscillation data, the values for the sterile neutrino mass preferred by oscillation analyses are significantly higher than the current cosmological bound. We review as well the bounds on extended dark sectors with additional light species based on the latest Planck CMB observations.

  15. Evaluation of plastic packaging materials used in radiation sterilized medical products and food

    NASA Astrophysics Data System (ADS)

    Fengmei, L. L.; Ying, W. W.; Xiaoguang, L. L.; Baoyu, Y. Y.

    2000-03-01

    This paper studied the results of evaluation on resistance to radiation, moisture permeability, bacteria permeability, tensile strength, elongation at break and sealing ability for several plastic films available on the market. The result shows that nylon, sarin, and polyethylene complex films, high and low density polyethylene films are applicable for packing of radiation sterilized products.

  16. Low-temperature low-damage sterilization based on UV radiation through plasma immersion

    NASA Astrophysics Data System (ADS)

    Pollak, J.; Moisan, M.; Kéroack, D.; Boudam, M. K.

    2008-07-01

    This paper introduces a new type of high-frequency (HF) sustained discharge where the HF field applicator is a planar transmission line that allows us to fill with plasma a long chamber of rectangular cross-section (typically 1 m × 15 cm × 5 cm). Peculiar interesting features of this plasma source are a low gas temperature (typically below 40 °C in the 1 Torr range in argon), broadband impedance matching with no need for retuning, stability and reproducibility of the discharge (non-resonant behaviour). This type of plasma source could be useful for web processing; nonetheless, it is applied here to plasma sterilization, taking advantage of its low gas temperature to inactivate microorganisms on polymer-made medical devices to avoid damaging them. The predominant biocide species are the UV photons emitted by the discharge whereas most plasma sterilization techniques call for reactive species such as O atoms and OH molecules, which induce significant erosion damage on polymers. Polystyrene microspheres are actually observed to be erosion-free under the current plasma sterilization conditions (scanning electron micrographs have been examined). Moreover, inactivation is quite fast: 106 B. atrophaeus spores deposited on a Petri dish are inactivated in less than 1 min. Correlation of the UV radiation with the spore inactivation rate is examined by (i) considering the emitted light intensity integrated over the 112-180 nm vacuum UV (VUV) range with a photomultiplier; (ii) looking with an optical spectrometer at the emission spectrum over the 200-400 nm UV range; (iii) using absorption spectroscopy to determine the role of the VUV argon resonant lines (105 and 107 nm) on spore inactivation. It is found that the test-reference spores are mainly inactivated by VUV photons (112-180 nm) that are primarily emitted by impurities present in the argon plasma.

  17. Design of sterile mucoadhesive hydrogels for use in drug delivery: effect of radiation on network structure.

    PubMed

    Singh, Baljit; Varshney, Lalit; Sharma, Vikrant

    2014-09-01

    Radiation induced graft copolymerization is pure, sterile and additive free method for the synthesis of hydrogels for biomedical applications. In the present work, attempt has been made to prepare the biocompatible, mucoadhesive hydrogels based on natural polysaccharide sterculia gum and polyvinylpyrrolidone (PVP) for use as drug delivery devices. The effect of gamma radiation on swelling and various network parameters of hydrogels such as the polymer volume fraction in the swollen state (ϕ), molecular weight of the polymer chain between two neighboring cross links (M¯c), crosslink density (ρ), and mesh size (ξ) have been studied. Hydrogels have been characterized with scanning electron micrographs (SEMs), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction study (XRD), thermo gravimetric analysis (TGA) and swelling studies. Swelling and mesh size decreased while gel strength and crosslink density increased with increase in radiation dose. The swelling of hydrogels and release of drug ciprofloxacin from drug loaded hydrogels occurred through non-Fickian diffusion mechanism. These hydrogels have been observed to have non-thrombogenic, haemo-compatible and mucoadhesive nature and could be used as mucoadhesive drug delivery system to deliver drug to gastro intestinal tract (GIT) in controlled manner.

  18. Radiation-induced gliomas

    PubMed Central

    Prasad, Gautam; Haas-Kogan, Daphne A.

    2013-01-01

    Radiation-induced gliomas represent a relatively rare but well-characterized entity in the neuro-oncologic literature. Extensive retrospective cohort data in pediatric populations after therapeutic intracranial radiation show a clearly increased risk in glioma incidence that is both patient age- and radiation dose/volume-dependent. Data in adults are more limited but show heightened risk in certain groups exposed to radiation. In both populations, there is no evidence linking increased risk associated with routine exposure to diagnostic radiation. At the molecular level, recent studies have found distinct genetic differences between radiation-induced gliomas and their spontaneously-occurring counterparts. Clinically, there is understandable reluctance on the part of clinicians to re-treat patients due to concern for cumulative neurotoxicity. However, available data suggest that aggressive intervention can lead to improved outcomes in patients with radiation-induced gliomas. PMID:19831840

  19. Development of radiation sterilized dip slides for enumerating lactic acid bacteria and total count in foodstuffs

    NASA Astrophysics Data System (ADS)

    Eisenberg, E.; Padova, R.; Kirsch, E.; Weissman, Sh.; Hirshfeld, T.; Shenfeld, A.

    APT agar (APT) used for enumeration of lactic acid bacteria and Plate Count agar (PCA) applied for total count were sterilized by gamma radiation using radiation dose of 10-15 kGy. Radiosterilized PCA and APT modified by adding catalase prior to irradiation, or APT with increased content of yeast extract performed, as well as, the heat sterilized commercial media. Growth performance was evaluated on several strains of microorganisms, as well as, by enumeration of bacteria in food products. Radiosterilization of culture media in final packaging, can be applied to produce dip slide kits containing PCA or APT.

  20. New U(1) gauge model of radiative lepton masses with sterile neutrino and dark matter

    DOE PAGES

    Adhikari, Rathin; Borah, Debasish; Ma, Ernest

    2016-02-23

    Here, an anomaly-free U(1) gauge extension of the standard model (SM) is presented. Only one Higgs doublet with a nonzero vacuum expectation is required as in the SM. New fermions and scalars as well as all SM particles transform nontrivially under this U(1), resulting in a model of three active neutrinos and one sterile neutrino, all acquiring radiative masses. Charged-lepton masses are also radiative as well as the mixing between active and sterile neutrinos. At the same time, a residual Z2 symmetry of the U(1) gauge symmetry remains exact, allowing for the existence of dark matter.

  1. The radiation enhancement of the sterility assurance levels of sterile fluids — A case study

    NASA Astrophysics Data System (ADS)

    Plessis, T. A. Du.; Rosekilly, I. C.

    1995-02-01

    A study was undertaken to determine the effect of low-dose gamma irradiation on aseptically admixed total parenteral nutrition (TPN) solutions to which large inocula of three test bacterial species, recognised as common contaminants of these products, were added. Attainable SALs of TPN solutions containing test bacteria were subsequently calculated. Results showed that a minimum absorbed radiation dose as low as 1.5 kGy improved the SAL of aseptically prepared TPN solutions from a SAL of 10 -3 to a value of less than 10 -8 for the microorganisms investigated. No measurable changes in amino acid, electrolyte, glucose and lipid components of the solutions were detected up to a dose of 8.3 kGy. Practical experience applying this radiation treatment of TPNs rendered excellent results leading to the routine application of the process in South Africa.

  2. The development of new radiation protocols for insect sterilization using long wavelength x-rays

    NASA Astrophysics Data System (ADS)

    Urquidi, Jacob; Brar, Ramaninder K.; Rodriguez, Stacy; Hansen, Immo

    2015-07-01

    Control of insect species for the protection of crops, livestock, and prevention of disease such as dengue fever and malaria is a high priority in today's global economy. Traditional methods such as pesticides have fallen out of favor because its effects are indiscriminate as well as adverse and unpredictable impacts on the environment. Modern novel techniques such as genetic modification have had trouble gaining traction due to ethics concerns and the potential for unforeseen side effects. One approach that has gained traction and has proven its efficacy is the use of ionizing radiation to affect sterility in insect species in order to scale back their population. Known as Sterile Insect Technique (SIT), it has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipertans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. We have investigated the effect of treatment with x-rays of different wavelengths on x-ray sterilized mosquito males. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males' longevity as well as an increase on the efficacy of sterilization while employing a substantially lower dose.

  3. The development of new radiation protocols for insect sterilization using long wavelength x-rays

    SciTech Connect

    Urquidi, Jacob Brar, Ramaninder K.; Rodriguez, Stacy; Hansen, Immo

    2015-07-23

    Control of insect species for the protection of crops, livestock, and prevention of disease such as dengue fever and malaria is a high priority in today’s global economy. Traditional methods such as pesticides have fallen out of favor because its effects are indiscriminate as well as adverse and unpredictable impacts on the environment. Modern novel techniques such as genetic modification have had trouble gaining traction due to ethics concerns and the potential for unforeseen side effects. One approach that has gained traction and has proven its efficacy is the use of ionizing radiation to affect sterility in insect species in order to scale back their population. Known as Sterile Insect Technique (SIT), it has proven very effective in eradicating certain dipteran insect populations. However, when standard sterilization methods developed for dipertans are applied to mosquito populations significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. We have investigated the effect of treatment with x-rays of different wavelengths on x-ray sterilized mosquito males. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males’ longevity as well as an increase on the efficacy of sterilization while employing a substantially lower dose.

  4. Radiation-induced pneumothorax

    SciTech Connect

    Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

    1983-01-01

    Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis.

  5. Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

    NASA Astrophysics Data System (ADS)

    Singh, Durgeshwer; Singh, Rita

    2012-11-01

    Wound debridement is essential for the removal of necrotic or nonviable tissue from the wound surface to create an environment conducive to healing. Nonsurgical enzymatic debridement is an attractive method due to its effectiveness and ease of use. Papain is a proteolytic enzyme derived from the fruit of Carica papaya and is capable of breaking down a variety of necrotic tissue substrates. The present study was focused on the use of gamma radiation for sterilization of papain dressing with wound debriding activity. Membranes with papain were prepared using 0.5% chitin in lithium chloride/dimethylacetamide solvent and sterilized by gamma radiation. Fluid absorption capacity of chitin-papain membranes without glycerol was 14.30±6.57% in 6 h. Incorporation of glycerol resulted in significant (p<0.001) increase in the absorption capacity. Moisture vapour transmission rate of the membranes was 4285.77±455.61 g/m2/24 h at 24 h. Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings. Infrared (IR) spectral scanning has shown that papain was stable on gamma irradiation at 25-35 kGy. The irradiated chitin-papain membranes were impermeable to different bacterial strains and also exhibited strong bactericidal action against both Gram-positive and Gram-negative bacteria. The fluid handling characteristics and the antimicrobial properties of chitin-papain membranes sterilized by gamma radiation were found suitable for use as wound dressing with debriding activity.

  6. Cosmology favoring extra radiation and sub-eV mass sterile neutrinos as an option.

    PubMed

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G; Tamborra, Irene; Wong, Yvonne Y Y

    2010-10-29

    Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{s} and effective number N{s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{s} is in the sub-eV range.

  7. Cosmology Favoring Extra Radiation and Sub-eV Mass Sterile Neutrinos as an Option

    SciTech Connect

    Hamann, Jan; Hannestad, Steen; Raffelt, Georg G.; Tamborra, Irene; Wong, Yvonne Y. Y.

    2010-10-29

    Precision cosmology and big-bang nucleosynthesis mildly favor extra radiation in the Universe beyond photons and ordinary neutrinos, lending support to the existence of low-mass sterile neutrinos. We use the WMAP 7-year data, small-scale cosmic microwave background observations from ACBAR, BICEP, and QuAD, the SDSS 7th data release, and measurement of the Hubble parameter from HST observations to derive credible regions for the assumed common mass scale m{sub s} and effective number N{sub s} of thermally excited sterile neutrino states. Our results are compatible with the existence of one or perhaps two sterile neutrinos, as suggested by LSND and MiniBooNE, if m{sub s} is in the sub-eV range.

  8. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Mondelaers, Win; Lahorte, Philippe

    This chapter is part one of a review in which the production and application of radiation-induced bioradicals is discussed. Bioradicals play a pivotal role in the complex chain of processes starting with the absorption of radiation in biological materials and ending with the radiation-induced biological after-effects. The general aspects of the four consecutive stages (physical, physicochemical, chemical and biological) are discussed from an interdisciplinary point of view. The close relationship between radiation dose and track structure, induced DNA damage and cell survival or killing is treated in detail. The repair mechanisms that cells employ, to insure DNA stability following irradiation, are described. Because of their great biomedical importance tumour suppressor genes involved in radiation-induced DNA repair and in checkpoint activation will be treated briefly, together with the molecular genetics of radiosensitivity. Part two of this review will deal with modern theoretical methods and experimental instrumentation for quantitative studies in this research field. Also an extensive overview of the applications of radiation-induced bioradicals will be given. A comprehensive list of references allows further exploration of this research field, characterised in the last decade by a substantial advance, both in fundamental knowledge and in range of applications.

  9. Induction of sterility in Anastrepha Fraterculus (Diptera: Tephritidae) by gamma radiation

    SciTech Connect

    Allinghi, A.; Gramajo, C.; Willink, E.; Vilardi, J.

    2007-03-15

    In relation to the application of the sterile insect technique (SIT) for the South American fruit fly Anastrepha fraterculus (Wiedemann), we analyzed the effect on adult fertility of different doses of gamma irradiation and the age of pupae at the time of irradiation. In a first experiment, we applied doses of 50, 70, and 90 Gy to pupae at 24, 48, 72, and 96 h before adult emergence. In a second experiment we irradiated pupae 48 h before emergence with 20, 40, and 60 Gy and estimated male and female fertility and sperm transfer by irradiated males. The results indicated pupal age at irradiation does not significantly affect male fertility. If males irradiated with 60 Gy are crossed to non-irradiated females the fertility is about 1%. Females irradiated with 40 Gy did not lay eggs independently of the male to which they mated. No significant effects of radiation were observed with respect to the ability of males to transfer sperm. A dose of 70 Gy applied 48 h before adult emergence induces 100% sterility in both males and females. (author) [Spanish] Para la aplicacion de la tecnica del insecto esteril (TIE) en Anastrepha fraterculus (Wiedemann), en este trabajo analizamos el efecto de diferentes dosis de irradiacion gamma y la edad optima de la pupa al momento de la irradiacion. En el primer experimento se evaluaron las dosis de 50, 70, y 90 Gy en pupas de 24, 48, 72, y 96 h antes de la emergencia del adulto. En el segundo experimento se irradiaron pupas 48 h antes de la emergencia con dosis de 20, 40, 60 Gy y se estimo la fertilidad de los machos y las hembras, y la transferencia de espermas por los machos irradiados. Los resultados indicaron que la irradiacion no modifico significativamente la fertilidad de los machos. En las cruzas de machos irradiados a 60 Gy con hembras no irradiadas se observo 1% de eclosion larvaria, mientras que las hembras irradiadas a 40 Gy no pusieron huevos. La irradiacion no afecto significativamente la transferencia de espermas de los

  10. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Lahorte, Philippe; Mondelaers, Wim

    This chapter represents the second part of a review in which the production and application of radiation-induced radicals in biological matter are discussed. In part one the general aspects of the four stages (physical, physicochemical, chemical and biological) of interaction of radiation with matter in general and biological matter in particular, were discussed. Here an overview is presented of modem technologies and theoretical methods available for studying these radiation effects. The relevance is highlighted of electron paramagnetic resonance spectroscopy and quantum chemical calculations with respect to obtaining structural information on bioradicals, and a survey is given of the research studies in this field. We also discuss some basic aspects of modem accelerator technologies which can be used for creating radicals and we conclude with an overview of applications of radiation processing in biology and related fields such as biomedical and environmental engineering, food technology, medicine and pharmacy.

  11. Evaluation of safety and efficacy of radiation-sterilized bone allografts in reconstructive oral surgery.

    PubMed

    Krasny, Marta; Krasny, Kornel; Kamiński, Artur; Zadurska, Małgorzata; Piekarczyk, Piotr; Fiedor, Piotr

    2013-09-01

    Bone grafting allows reconstruction of the atrophied or destroyed alveolar process. In orthopaedics and traumatology allogeneic grafting has been used to restore defects of osseous tissue for over 60 years. In order to improve safety of the graft recipient, sterilized allogeneic grafts have been use. The aim of the study was to assess the direct and long-term outcomes following augmentation of atrophied alveolar processes with the use of radiation-sterilized allogeneic bone grafts. Sixty-eight patients were surgically treated between 2004 and 2011: 29 underwent open sinus floor elevation, post-extraction alveoli augmentation was performed in 16 subjects and 23 underwent reconstruction of the atrophied alveolar process. Augmentation of bone defects used bone granulate in 63 patients and bone blocks stabilized with titanium screws in 5 patients. PRF membranes collected from the patient's blood were also used in all the procedures. In each of the cases optimal dimensions of the alveolar process were obtained allowing embedment of BIOMET 3I dental implant/-s. In all the patients the defects were successfully restored with implant-supported prostheses. Radiation-sterilized allogeneic bone grafts proved to be safe and effective for the patients and manageable for the surgeon constituting a good alternative to autogeneic material.

  12. Studies on the disposable obstetrical dressings sterilized by radiation and the effect of its application

    NASA Astrophysics Data System (ADS)

    Haiqiao, Wang; Sujing, Sun

    1993-10-01

    In order to attain an optimum sterilization treatment to obstetric dressings, a new product made by us, with 60Coγ-ray, the effects of radiation on standard bacteria pseudomonas aeruginosa ATcc27853, Escherichia coli ATcc25922, Staphylococcus aureus ATcc25923, Clostridium PB6KA, short Bacillus E60163202 and HBSAg were studied. Results showed that at the absorbed dose of 10 kGy, all the bacteria, bacillus and HBSAg were killed off, and sterilized with the dose, the dressings can completely accord with the demands of hygiene, which was further confirmed by microbiological and poisonous tests and the effects of clinical application. In Nov. 1988, the dressings was awarded the excellent prize in the 1st international exhibition of patent, new technique and new equipment in Guangzhou; its effective application is also reported in the paper.

  13. Radiation Induced Oral Mucositis

    PubMed Central

    PS, Satheesh Kumar; Balan, Anita; Sankar, Arun; Bose, Tinky

    2009-01-01

    Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i) With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii) who also received concomitant chemotherapy; (iii) who received a total dose over 5,000 cGy; and (iv) who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene PMID:20668585

  14. Radiation-induced schwannomas

    SciTech Connect

    Rubinstein, A.B.; Reichenthal, E.; Borohov, H.

    1989-06-01

    The histopathology and clinical course of three patients with schwannomas of the brain and high cervical cord after therapeutic irradiation for intracranial malignancy and for ringworm of the scalp are described. Earlier reports in the literature indicated that radiation of the scalp may induce tumors in the head and neck. It is therefore suggested that therapeutic irradiation in these instances was a causative factor in the genesis of these tumors.

  15. Radiation Induced Genomic Instability

    SciTech Connect

    Morgan, William F.

    2011-03-01

    Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a “mutator phenotype” (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target – the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend

  16. The Efficacy of Ultraviolet Radiation for Sterilizing Tools Used for Surgically Implanting Transmitters into Fish

    SciTech Connect

    Walker, Ricardo W.; Markillie, Lye Meng; Colotelo, Alison HA; Gay, Marybeth E.; Woodley, Christa M.; Brown, Richard S.

    2013-02-28

    Telemetry is frequently used to examine the behavior of fish, and the transmitters used are normally surgically implanted into the coelom of fish. Implantation requires the use of surgical tools such as scalpels, forceps, needle holders, and sutures. When several fish are implanted consecutively for large telemetry studies, it is common for surgical tools to be sterilized or, at minimum, disinfected between each use so that pathogens that may be present are not spread among fish. However, autoclaving tools can take a long period of time, and chemical sterilants or disinfectants can be harmful to both humans and fish and have varied effectiveness. Ultraviolet (UV) radiation is commonly used to disinfect water in aquaculture facilities. However, this technology has not been widely used to sterilize tools for surgical implantation of transmitters in fish. To determine its efficacy for this application, Pacific Northwest National Laboratory researchers used UV radiation to disinfect surgical tools (i.e., forceps, needle holder, stab scalpel, and suture) that were exposed to one of four aquatic organisms that typically lead to negative health issues for salmonids. These organisms included Aeromonas salmonicida, Flavobacterium psychrophilum, Renibacterium salmoninarum, and Saprolegnia parasitica. Surgical tools were exposed to the bacteria by dipping them into a confluent suspension of three varying concentrations (i.e., low, medium, high). After exposure to the bacterial culture, tools were placed into a mobile Millipore UV sterilization apparatus. The tools were then exposed for three different time periods—2, 5, or 15 min. S. parasitica, a water mold, was tested using an agar plate method and forceps-pinch method. UV light exposures of 5 and 15 min were effective at killing all four organisms. UV light was also effective at killing Geobacillus stearothermophilus, the organism used as a biological indicator to verify effectiveness of steam sterilizers. These

  17. Molecular mapping of a new induced gene for nuclear male sterility in sunflower (Helianthus annuus L.)

    USDA-ARS?s Scientific Manuscript database

    A new NMS line, NMS HA89-872, induced by mitomycin C and streptomycin carries a single recessive male-sterile gene ms6. An F2 population of 88 plants was obtained from a cross between nuclear male-sterile mutant NMS HA89-872 (msms) and male-fertile line RHA271 (MsMs). 225 SSR primers and 9 RFLP-deri...

  18. Sterilization System

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Cox Sterile Products, Inc.'s Rapid Heat Transfer Sterilizer employs a heat exchange process that induces rapid air movement; the air becomes the heat transfer medium, maintaining a uniform temperature of 375 degrees Fahrenheit. It features pushbutton controls for three timing cycles for different instrument loads, a six-minute cycle for standard unpackaged instruments, eight minutes for certain specialized dental/medical instruments and 12 minutes for packaged instruments which can then be stored in a drawer in sterile condition. System will stay at 375 degrees all day. Continuous operation is not expensive because of the sterilizer's very low power requirements.

  19. High temperature-induced sterility in the female Nile tilapia, Oreochromis niloticus.

    PubMed

    Pandit, Narayan Prasad; Bhandari, Ramji Kumar; Kobayashi, Yasuhisa; Nakamura, Masaru

    2015-03-01

    High temperature treatments induce germ cell loss in gonads of vertebrate animals, including fish. It could be a reliable source for induction of sterility if the treatments led to a permanent loss of germ cells. Here we report that heat treatment at 37 °C for 45-60 days caused a complete loss of germ cells in female Nile tilapia, Oreochromis niloticus, and that sterility was achieved in fish at all stages of their life cycle. Unlike previous observations, germ cells did not repopulate even after returning them to the water at control conditions suggesting permanent depletion of germ cells. Gonadal somatic cells immunopositive for 3β-hydroxysteroid dehydrogenase (3β-HSD) were clustered at one end of the germ cell depleted gonads close to the blood vessel. Serum level of testosterone, 11-ketotestosterone, and 17β-estradiol was significantly decreased in sterile fish compared to control. Body weight of sterile fish was higher than control fish at the end of experiment. Our observations of increased growth and permanent sterilization in the high temperature-treated fish suggest that this method could be an appropriate and eco-friendly tool for inducing sterility in fish with a higher thermal tolerance.

  20. Trend of radiation sterilization business in Japan and how to develop new applications

    NASA Astrophysics Data System (ADS)

    Takahashi, T.

    2004-09-01

    There are thick and high barriers against promotion of radiation processing, especially in Japan. These are regulation, material, cost and consumer's emotion. Release of validation guidelines for sterilization from the Japanese government in 1997 based on ISO11137 and ISO9001 made it easy for us to use irradiation. Most remarkable regulation impacting on a switch to irradiation from ethylene oxide (EtO) was pollutant release and transfer registers (PRTR) proclaimed in 2001 and enforced in 2002. EtO gas is included in the list of poisonous materials. In addition, the government published brochures and distributed them to all manufacturers to improve the employee's health and to keep work area clean. These governmental movements are pushing EtO users to decide if they will continue or give up EtO. To enhance irradiation business, both regulation and de-regulation are important factors.

  1. Radiative neutrino mass matrix for three active plus one sterile species

    SciTech Connect

    Gaur, N.; Ghosal, A.; Ma, E.; Roy, P.

    1998-10-01

    A simple unifying mass matrix is presented for the three active and one sterile neutrinos {nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}, and {nu}{sub s}, using an extension of the radiative mechanism proposed some time ago by Zee. The total neutrino-oscillation data are explained by the scheme {nu}{sub e}{leftrightarrow}{nu}{sub s} (solar), {nu}{sub {mu}}{leftrightarrow}{nu}{sub {tau}} (atmospheric) and {nu}{sub e}{leftrightarrow}{nu}{sub {mu}} (LSND). We obtain the interesting approximate relationship ({Delta}m{sup 2}){sub atm}{approx_equal}2[({Delta}m{sup 2}){sub solar}({Delta}m{sup 2}){sub LSND}]{sup 1/2} which is well satisfied by the data. {copyright} {ital 1998} {ital The American Physical Society}

  2. Effects of gamma radiation sterilization and strain rate on compressive behavior of equine cortical bone.

    PubMed

    Tüfekci, Kenan; Kayacan, Ramazan; Kurbanoğlu, Cahit

    2014-06-01

    Gamma radiation has been widely used for sterilization of bone allograft. However, sterilization by gamma radiation damages the material properties of bone which is a major clinical concern since bone allograft is used in load bearing applications. While the degree of this damage is well investigated for quasi-static and cyclic loading conditions, there does not appear any information on mechanical behavior of gamma-irradiated cortical bone at high speed loading conditions. In this study, the effects of gamma irradiation on high strain rate compressive behavior of equine cortical bone were investigated using a Split Hopkinson Pressure Bar (SHPB). Quasi-static compression testing was also performed. Equine cortical bone tissue from 8year old retired racehorses was divided into two groups: non-irradiated and gamma-irradiated at 30kGy. Quasi-static and high strain rate compression tests were performed at average strain rates of 0.0045/s and 725/s, respectively. Agreeing with previous results on the embrittlement of cortical bone when gamma-irradiated, the quasi-static results showed that gamma-irradiation significantly decreased ultimate strength (9%), ultimate strain (27%) and toughness (41%), while not having significant effect on modulus of elasticity, yield strain and resilience. More importantly, contrary to what is typically observed in quasi-static loading, the gamma-irradiated bone under high speed loading showed significantly higher modulus of elasticity (45%), ultimate strength (24%) and toughness (26%) than those of non-irradiated bone, although the failure was at a similar strain. Under high speed loading, the mechanical properties of bone allografts were not degraded by irradiation, in contrast to the degradation measured in this and prior studies under quasi-static loading. This result calls into question the assumption that bone allograft is always degraded by gamma irradiation, regardless of loading conditions. However, it needs further investigation

  3. Microbiological safety and clinical efficacy of radiation sterilized amniotic membranes for treatment of second-degree burns.

    PubMed

    Singh, Rita; Purohit, Sumita; Chacharkar, M P; Bhandari, P S; Bath, A S

    2007-06-01

    Amniotic membranes collected from the placentae of screened donors were processed and sterilized by gamma irradiation at 25 kGy. The sterility assurance level (SAL) of gamma irradiated amniotic membranes and clinical efficacy in second-degree burn wound healing were evaluated. Processed air-dried amniotic tissue from 159 batches of processing was checked for the bioburden level before sterilization. About 39% of the tissues had bioburden in the range of 10(1)-10(2)/100 cm(2) and 54.8% in the range of 10(2)-10(3)/100 cm(2). Based on the bioburden of the processed tissue prior to sterilization and the D(10) value of 2.3 kGy for the radiation resistant reference strain Bacillus pumilus, the sterility assurance level of the amniotic membranes irradiated at 25 kGy is found to be 10(-7) to 10(-11). The burn wound healing rate was compared between the radiation sterilized amniotic membranes and glycerol preserved amniotic membranes. Fifty patients with partial-thickness burns (up to 70% TBSA) were selected for the study. The scalds constituted 82% (41 patients) whereas flame burns accounted for 18% (9 patients). Various aspects like ease of application, patient comfort, development of fluid under the membrane, bacterial culture of drained fluid, rate of epithelialization, development of hypertrophic scars, keloids, unstable scars and restriction of joint movements were recorded with the application of gamma irradiated and glycerol preserved membranes. Radiation sterilized amniotic membranes had advantage over the glycerolized membranes with respect to the ease of application. Five patients with glycerol preserved membranes and four with gamma irradiated membranes developed fluid. The bacteriology of fluid showed Pseudomonas aeruginosa in four cases, Staphylococcus aureus in two cases, Escherichia coli in two cases and Acinetobacter in one case. The application of radiation sterilized amniotic membranes on the burn wound favoured epithelialization. In all the patients

  4. Effect of radiation sterilization and aging on ultrahigh molecular weight polyethylene

    SciTech Connect

    Roe, R.J.; Grood, E.S.; Shastri, R.; Gosselin, C.A.; Noyes, F.R.

    1981-03-01

    The mechanical properties of polyethylene components used in prosthesis are altered after fabrication by the sterilization procedure and by the environmental and mechanical aging which occurs after implantation. To assess the importance and extent of these alterations, ultrahigh molecular weight polyethylenes from two sources, Hercules 1900 and RCH 1000C, were subjected to gamma-ray irradiation and aging in serum and argon environments. Changes induced by these treatments in the structural and mechanical parameters have been determined by a variety of experimental techniques. The effect of irradiation is to introduce crosslinks and to increase the degree of crystallinity resulting in changes in the tensile properties in the direction of higher stiffness and reduced ductility. Aging for six months produced similar changes with subtle differences. The results suggest that the initially low degree of crystallinity which results from the sluggish mobility of the very long chain molecules offers the opportunity for significant changes in the properties during use in the long run.

  5. Radiation-induced disease.

    PubMed

    Bobrow, M

    1993-01-01

    The term radiation covers a wide spectrum of forms of energy, most of which have at one stage or another been suspected of causing human ill health. In general, study of the effects of radiation on health involves a mix of scientific disciplines, from population epidemiology to physics, which are seldom if ever found in a single scientist. As a result, interdisciplinary communication is of the utmost importance, and is a potent source of misunderstanding and misinformation. The forms of radiation which have been most specifically associated with health effects include ionizing and ultraviolet radiation. Claimed effects of electromagnetic and microwave radiation (excluding thermal effects) are too indefinite for detailed consideration. Ionizing radiation is a well-documented mutagen, which clearly causes cancers in humans, and human exposure has been increased by atomic weapons testing and medical and industrial uses of radioactivity. There is also a growing awareness of the possible role of some types of natural radiation, such as radon, in causing disease. Ultraviolet radiation is also associated with cancers, and is suspected of involvement in the increasing incidence of skin cancers in European populations. Factors thought to underlie recent changes in exposure to these mutagens are discussed.

  6. Radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

    Kronenberg, A.

    1994-01-01

    Quantitative assessment of the heritable somatic effects of ionizing radiation exposures has relied upon the assumption that radiation-induced lesions were 'fixed' in the DNA prior to the first postirradiation mitosis. Lesion conversion was thought to occur during the initial round of DNA replication or as a consequence of error-prone enzymatic processing of lesions. The standard experimental protocols for the assessment of a variety of radiation-induced endpoints (cell death, specific locus mutations, neoplastic transformation and chromosome aberrations) evaluate these various endpoints at a single snapshot in time. In contrast with the aforementioned approaches, some studies have specifically assessed radiation effects as a function of time following exposure. Evidence has accumulated in support of the hypothesis that radiation exposure induces a persistent destabilization of the genome. This instability has been observed as a delayed expression of lethal mutations, as an enhanced rate of accumulation of non-lethal heritable alterations, and as a progressive intraclonal chromosomal heterogeneity. The genetic controls and biochemical mechanisms underlying radiation-induced genomic instability have not yet been delineated. The aim is to integrate the accumulated evidence that suggests that radiation exposure has a persistent effect on the stability of the mammalian genome.

  7. Radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

    Kronenberg, A.

    1994-01-01

    Quantitative assessment of the heritable somatic effects of ionizing radiation exposures has relied upon the assumption that radiation-induced lesions were 'fixed' in the DNA prior to the first postirradiation mitosis. Lesion conversion was thought to occur during the initial round of DNA replication or as a consequence of error-prone enzymatic processing of lesions. The standard experimental protocols for the assessment of a variety of radiation-induced endpoints (cell death, specific locus mutations, neoplastic transformation and chromosome aberrations) evaluate these various endpoints at a single snapshot in time. In contrast with the aforementioned approaches, some studies have specifically assessed radiation effects as a function of time following exposure. Evidence has accumulated in support of the hypothesis that radiation exposure induces a persistent destabilization of the genome. This instability has been observed as a delayed expression of lethal mutations, as an enhanced rate of accumulation of non-lethal heritable alterations, and as a progressive intraclonal chromosomal heterogeneity. The genetic controls and biochemical mechanisms underlying radiation-induced genomic instability have not yet been delineated. The aim is to integrate the accumulated evidence that suggests that radiation exposure has a persistent effect on the stability of the mammalian genome.

  8. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays.

    PubMed

    De Guzman, Zenaida M; Cervancia, Cleofas R; Dimasuay, Kris Genelyn B; Tolentino, Mitos M; Abrera, Gina B; Cobar, Ma Lucia C; Fajardo, Alejandro C; Sabino, Noel G; Manila-Fajardo, Analinda C; Feliciano, Chitho P

    2011-10-01

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a ⁶⁰Co source. Surviving spores were counted and used to estimate the decimal reduction (D₁₀) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10⁵- 9 × 10³ spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D(min)) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to γ-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials.

  9. Steric-electronic effects in malarial peptides inducing sterile immunity

    SciTech Connect

    Moreno-Vranich, Armando; Patarroyo, Manuel E.

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Is it evident that the residues position are relevant regarding of {phi} angular value. Black-Right-Pointing-Pointer The geometry considered for detailing the alterations undergone by HABPs. Black-Right-Pointing-Pointer The inter planar interactions ruled by clashes between the atoms making them up. -- Abstract: Conserved Plasmodium falciparum high activity binding peptides' (HABPs) most relevant proteins involved in malaria parasite invasion are immunologically silent; critical binding residues must therefore be specifically replaced to render them highly immunogenic and protection-inducing. Such changes have a tremendous impact on these peptides' steric-electronic effects, such as modifications to peptide length peptide bonds and electronic orbitals' disposition, to allow a better fit into immune system MHCII molecules and better interaction with the TCR which might account for the final immunological outcome.

  10. Radiation-induced cardiovascular effects

    NASA Astrophysics Data System (ADS)

    Tapio, Soile

    Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

  11. Converting from ETO to radiation sterilization: Educating the medical supply industry

    NASA Astrophysics Data System (ADS)

    Bedward, D. A.; Brinston, R. M.; Kotler, J.

    1995-02-01

    In this paper the authors examine some relevant factors influencing the conversion from ethylene oxide sterilization to gamma sterilization. Marketing tactics to promote and stimulate this activity are reviewed. TEAM GAMMA, an educational vehicle developed by Nordion International Inc. is described from the concept acceptance to the very positive results obtained. The structure of this multi disciplinary team of consultants is described. Topics presented by this team include sterilization basics, material compatibility, device design manufacturing and other aspects of the sterilization process. The authors conclude that assisting in the education of the medical device manufacturers regarding the conversion from EtO to gamma processing provides payback for Nordion and the gamma processing industry. This assessment is based on the results of the ten seminars presented to date.

  12. Reflection effects during the radiation sterilization of ultra high molecular weight polyethylene for total knee replacements.

    PubMed

    Barron, Declan; Birkinshaw, Colin; Collins, Maurice N

    2015-08-01

    Ultra high molecular weight polyethylene has been subject to γ irradiation whilst in contact with a stainless steel backing. This leads to reflection of the incident radiation and to backscattered electrons, both of which contribute to an effective increase in dose received. Radiation induced damage through scission of inter-lamellae tie chains results in an increase in crystallinity. At a nominal received dose of 100 kGy the effect of the metal backing is to increase crystallinity by approximately a third relative to the increase observed in materials irradiated in the absence of the backing. The metal backing induced reflections cause a bimodal recrystallization distribution giving rise to a more refined crystal population. As implant materials are subject to intermittent, but high, stress levels it is clearly of importance to examine how these reflection induced structural changes influence mechanical properties. Stress/strain results have indicated that subsequent yielding behavior is governed by the counteracting mechanisms of crystal growth and lamella reorganization mechanisms and in metal backed components the resulting morphological inhomogeneity may have important property consequences for wear induced failures in total knee replacement materials.

  13. Comparison of the effects of gamma radiation and low temperature hydrogen peroxide gas plasma sterilization on the molecular structure, fatigue resistance, and wear behavior of UHMWPE.

    PubMed

    Goldman, M; Pruitt, L

    1998-06-05

    The effects of gamma radiation and low temperature hydrogen peroxide gas plasma (HPGP) sterilization on structure and cyclic mechanical properties were examined for orthopedic grade ultra-high-molecular-weight polyethylene (UHMWPE) and compared to each other as well as to no sterilization (control). Density was monitored with a density gradient column and was found to be directly influenced by the sterilization method employed: Gamma radiation led to an increase, while plasma did not. Oxidation of the polymer was studied by observing changes in the carbonyl peak with Fourier transform infrared spectrometry and was found to be strongly affected by both gamma radiation and subsequent aging, while plasma sterilization had little effect. Gamma radiation resulted in embrittlement of the polymer and a decreased resistance to fatigue crack propagation. This mechanical degradation was a direct consequence of postradiation oxidation and molecular evolution of the polymer and was not observed in the plasma-sterilized polymer. Both gamma radiation and plasma sterilization led to improved wear performance of the UHMWPE compared to the nonsterile control material.

  14. A novel screen for genes associated with pheromone-induced sterility

    PubMed Central

    Camiletti, Alison L.; Percival-Smith, Anthony; Croft, Justin R.; Thompson, Graham J.

    2016-01-01

    For honey bee and other social insect colonies the ‘queen substance’ regulates colony reproduction rendering workers functionally sterile. The evolution of worker reproductive altruism is explained by inclusive fitness theory, but little is known of the genes involved or how they regulate the phenotypic expression of altruism. We previously showed that application of honeybee queen pheromone to virgin fruit flies suppresses fecundity. Here we exploit this finding to identify genes associated with the perception of an ovary-inhibiting social pheromone. Mutational and RNAi approaches in Drosophila reveal that the olfactory co-factor Orco together with receptors Or49b, Or56a and Or98a are potentially involved in the perception of queen pheromone and the suppression of fecundity. One of these, Or98a, is known to mediate female fly mating behaviour, and its predicted ligand is structurally similar to a methyl component of the queen pheromone. Our novel approach to finding genes associated with pheromone-induced sterility implies conserved reproductive regulation between social and pre-social orders, and further helps to identify candidate orthologues from the pheromone-responsive pathway that may regulate honeybee worker sterility. PMID:27786267

  15. A Mutant dec-1 Transgene Induces Dominant Female Sterility in Drosophila melanogaster

    PubMed Central

    Spangenberg, Daniel K.; Waring, Gail L.

    2007-01-01

    The Drosophila dec-1 gene produces three proproteins required for female fertility and eggshell assembly. The three proproteins are distinguished by their C termini. Fc106, the most abundant proprotein, is cleaved within the vitelline membrane to three mature derivatives in a developmentally regulated manner. To define sequences within fc106 that are critical for its function, we created wild-type and mutant versions of an fc106 cDNA transgene. The functional consequences of the mutations were assessed in dec-14, a female-sterile splicing mutant that does not produce the fc106 isoform. The fertility of dec-14 females was restored by the introduction of either a wild-type transgene or a transgene bearing a C-terminal deletion that included fc106-specific sequences. Surprisingly, the removal of internal coding sequences created an aberrant DEC-1 proprotein that induced female sterility when introduced into wild-type flies. Dominant female sterility was not associated with larger deletions that included the fc106 N terminus, suggesting that abnormal juxtaposition of N- and C-terminal sequences in the aberrant proprotein interfered with endogenous DEC-1 proteins. Changes in the fractionation behavior of the endogenous fc106 C-terminal derivative, s60, and morphological changes in the endochorion in response to expression of the aberrant proprotein support this interpretation. PMID:18039879

  16. Imprints of C P violation induced by sterile neutrinos in T2K data

    NASA Astrophysics Data System (ADS)

    Klop, N.; Palazzo, A.

    2015-04-01

    We investigate the impact of light (˜ eV ) sterile neutrinos in the long-baseline experiment T2K. We show that, within the 3 +1 scheme, for mass-mixing parameters suggested by the short-baseline anomalies, the interference among the sterile and the atmospheric oscillation frequencies induces a new term in the νμ→νe transition probability, which has the same order of magnitude of the standard 3-flavor solar-atmospheric interference term. We show, for the first time, that current T2K data, taken together with the results of the θ13-dedicated reactor experiments, are sensitive to two of the three C P -violating phases involved in the 3 +1 scheme. Both the standard C P phase and the new one (δ13≡δ and δ14 in our parameterization choice) tend to have a common best-fit value δ13≃δ14≃-π /2 . Quite intriguingly, the inclusion of sterile neutrino effects leads to better agreement between the two estimates of θ13 obtained, respectively, from reactors and T2K, which in the 3-flavor framework are slightly different.

  17. Hospital waste sterilization: A technical and economic comparison between radiation and microwaves treatments

    NASA Astrophysics Data System (ADS)

    Tata, A.; Beone, F.

    1995-09-01

    Hospital waste (HW) disposal is becoming a problem of increasing importance in almost all industrially advanced countries. In Italy the yearly hospital waste production is about 250,000 tons and only 60,000 tons are treated by incineration at present time. As by a recent Italian law a meaningful percentage of HW (50 to 60%), corresponding to food residuals, plastics, paper, various organic materials, etc., could be landfilled as municipal refuses if preliminarily submitted to a suitable sterilization treatment. Under this perspective, sterilization/sanitation techniques represent now a technically and commercially viable alternative to HW thermal destruction that, besides, is more and more socially and politically less accepted. Electron Beam (EB) and Microwave (MW) treatments are two of the most interesting and emerging HW sterilization techniques, and, based on engineering real data, a technical and economic comparison is carried out, focusing vantages and limits of each process.

  18. The backcross sterility technique

    Treesearch

    V. C. Mastro; A. Pellegrini-Toole

    1991-01-01

    The sterile insect technique (SIT) and the induced inherited (F1) sterility technique have been investigated for a number of lepidopterous pests, including the gypsy moths. Another technique, backcross sterility, which could potentially prove as or more useful for control of pest species has been developed for the control of only one lepidopteran...

  19. Four-segmented Rift Valley fever virus induces sterile immunity in sheep after a single vaccination.

    PubMed

    Wichgers Schreur, Paul J; Kant, Jet; van Keulen, Lucien; Moormann, Rob J M; Kortekaas, Jeroen

    2015-03-17

    Rift Valley fever virus (RVFV), a mosquito-borne virus in the Bunyaviridae family, causes recurrent outbreaks with severe disease in ruminants and occasionally humans. The virus comprises a segmented genome consisting of a small (S), medium (M) and large (L) RNA segment of negative polarity. The M-segment encodes a glycoprotein precursor (GPC) protein that is co-translationally cleaved into Gn and Gc, which are required for virus entry and fusion. Recently we developed a four-segmented RVFV (RVFV-4s) by splitting the M-genome segment, and used this virus to study RVFV genome packaging. Here we evaluated the potential of a RVFV-4s variant lacking the NSs gene (4s-ΔNSs) to induce protective immunity in sheep. Groups of seven lambs were either mock-vaccinated or vaccinated with 10(5) or 10(6) tissue culture infective dose (TCID50) of 4s-ΔNSs via the intramuscular (IM) or subcutaneous (SC) route. Three weeks post-vaccination all lambs were challenged with wild-type RVFV. Mock-vaccinated lambs developed high fever and high viremia within 2 days post-challenge and three animals eventually succumbed to the infection. In contrast, none of the 4s-ΔNSs vaccinated animals developed clinical signs during the course of the experiment. Vaccination with 10(5) TCID50 via the IM route provided sterile immunity, whereas a 10(6) dose was required to induce sterile immunity via SC vaccination. Protection was strongly correlated with the presence of RVFV neutralizing antibodies. This study shows that 4s-ΔNSs is able to induce sterile immunity in the natural target species after a single vaccination, preferably administrated via the IM route.

  20. Damage of office supply, personal use items, and over-the-counter medical devices after sterilization by ethylene oxide gas, electron beam, and gamma radiation.

    PubMed

    Lucas, Anne D; Merritt, Katharine; Hitchins, Victoria M

    2004-01-01

    After letters containing Bacillus anthracis spores entered the U.S. mail in 2001, a problem emerged regarding how to decontaminate the letters, packages, and personal items in offices that received these letters. The effects of three sterilization methods (i.e. ethylene oxide gas [EO], electron beam [e-beam] radiation, and gamma radiation) were evaluated for a variety of office supply and equipment, personal use items, and over-the-counter medical devices. No single sterilization method was suitable for all items that could be mailed or found in an office. Damage or discoloration was evident for some items by each sterilization method. There were changes in the color of certain items, such as some of the packaging material, some pacifiers, some of the fabrics, and the nylon stockings after e-beam and gamma radiation. Both e-beam and gamma radiation damaged all film samples. Following EO sterilization and normal aeration, there were a number of samples with high (above 250 microg/g) levels of EO and samples with detectable ethylene chlorohydrin levels. The data would suggest that certain items exposed to EO sterilization must be further aerated prior to use, or discarded. Generic descriptions of products (such as plastics) or grouping of items (such as condoms) were not sufficient to predict what is safe in terms of EO residual levels remaining on an item. Successful decontamination of a wide variety of items will require careful selection of different sterilization methods.

  1. Radiation-induced bladder carcinoma

    SciTech Connect

    Uyama, T.; Nakamura, S.; Moriwaki, S.

    1981-01-01

    Two cases are presented of radiation-induced bladder carcinoma which followed prior irradiation for cervical carcinoma of the uterus. One was a sixty-eight-year-old woman with bladder carcinoma fourteen years after irradiation (total dose of 4,500 rad) for cervical carcinoma of the uterus. The other was a sixty-four-year-old woman with bladder carcinoma twenty-five years after irradiation with 150-K volt apparatus for cervical carcinoma of the uterus. From the late radiation change of the skin, it was estimated that the total dose of prior radiation might be 4,000 rad or more. Both had high-grade, high-stage transitional cell bladder carcinoma, and the former was with marked mucus-forming adenomatous metaplasia.

  2. Radiation-Induced Oral Mucositis

    PubMed Central

    Maria, Osama Muhammad; Eliopoulos, Nicoletta; Muanza, Thierry

    2017-01-01

    Radiation-induced oral mucositis (RIOM) is a major dose-limiting toxicity in head and neck cancer patients. It is a normal tissue injury caused by radiation/radiotherapy (RT), which has marked adverse effects on patient quality of life and cancer therapy continuity. It is a challenge for radiation oncologists since it leads to cancer therapy interruption, poor local tumor control, and changes in dose fractionation. RIOM occurs in 100% of altered fractionation radiotherapy head and neck cancer patients. In the United Sates, its economic cost was estimated to reach 17,000.00 USD per patient with head and neck cancers. This review will discuss RIOM definition, epidemiology, impact and side effects, pathogenesis, scoring scales, diagnosis, differential diagnosis, prevention, and treatment. PMID:28589080

  3. Radiation-Induced Oral Mucositis.

    PubMed

    Maria, Osama Muhammad; Eliopoulos, Nicoletta; Muanza, Thierry

    2017-01-01

    Radiation-induced oral mucositis (RIOM) is a major dose-limiting toxicity in head and neck cancer patients. It is a normal tissue injury caused by radiation/radiotherapy (RT), which has marked adverse effects on patient quality of life and cancer therapy continuity. It is a challenge for radiation oncologists since it leads to cancer therapy interruption, poor local tumor control, and changes in dose fractionation. RIOM occurs in 100% of altered fractionation radiotherapy head and neck cancer patients. In the United Sates, its economic cost was estimated to reach 17,000.00 USD per patient with head and neck cancers. This review will discuss RIOM definition, epidemiology, impact and side effects, pathogenesis, scoring scales, diagnosis, differential diagnosis, prevention, and treatment.

  4. Entanglement-induced quantum radiation

    NASA Astrophysics Data System (ADS)

    Iso, Satoshi; Tatsukawa, Rumi; Ueda, Kazushige; Yamamoto, Kazuhiro

    2017-08-01

    Quantum entanglement of the Minkowski vacuum state between left and right Rindler wedges generates thermal behavior in the right Rindler wedge, which is known as the Unruh effect. In this paper, we show that there is another consequence of this entanglement, namely entanglement-induced quantum radiation emanating from a uniformly accelerated object. We clarify why it is in agreement with our intuition that incoming and outgoing energy fluxes should cancel each other out in a thermalized state.

  5. Enhancement of the kinetics of the aeration of ethylene oxide sterilized polymers using microwave radiation.

    PubMed

    Matthews, I P; Gibson, C; Samuel, A H

    1989-02-01

    Ethylene oxide (EO) is used extensively to sterilize medical supplies that are heat sensitive. EO residues in materials post sterilization can present a hazard to patients at the point of use. Protracted aeration (i.e. degassing) times are necessary post sterilization to reduce EO residues to an accepted level. The sorption of EO into polyvinylchloride was found to be an active process given that at sorption equilibrium (i.e. when the net flow of diffusant into the host material has reduced to zero) the number of molecules of EO per unit volume was greater in PVC than in its external environment. The diffusion coefficient (D) was concentration (c) dependent and the relationship which best describes this dependence was D(c) alpha ln c. The diffusion of EO was dramatically accelerated (as evidenced by a time saving in degassing of up to 400%) if microwave heating (2.45 GHz) was used instead of conventional heating for the same macroscopic temperature. The values of activation energy for diffusion were obtained from the respective Arrhenius plots of diffusion coefficient versus inverse temperature for each process. In general, even small reductions in activation energy can greatly increase the specific rate of reaction. The relative efficacy of microwaves in eliminating EO residues as evidenced by this data occurs as a result of microwaves reducing the activation energy for diffusion by almost a factor of two. The relative efficiency of microwave desorption compared to conventional aeration offers considerable gains in the cost-effectiveness of gas sterilization since it will permit a much greater throughput of material, thereby obviating the need for excessively large inventories of equipment.

  6. The effect of gamma radiation on sterility and mating ability of brown planthopper, Nilaparvata lugens(Stål) in field cage

    NASA Astrophysics Data System (ADS)

    Limohpasmanee, W.; Kongratarpon, T.; Tannarin, T.

    2017-06-01

    The brown planthopper, Nilaparvata lugens(Stål) is the major rice pest in Thailand. Adults and nymphs suck the sap from the rice plant causing it to wilt and transmitting the grassy stunt and the ragged stunt diseases. The population suppression by the sterile insect technique is overwhelmingly a function of mating between sterile males and wild females. The objectives of these experiments were to determine the suitable dose which induces partially sterile in N. lugens and their effect on wild population in the field cages. One-day-old 4th and 5th instar nymphs and adults were irradiated in a 60Co irradiator at the doses of 30, 60, 90 and 120 Gy. It was found that irradiation at the dose of 90 Gy induced complete sterility in female and 78.47 % sterility in males. The inherited sterility were transferred to their progenies and induced 51.46 and 77.00 % sterility in F-1 males and females. The irradiation as the mention dose did not affect mating ability. The competitiveness index was increased when the ratio of irradiated males per normal male was increased. The releasing irradiated males at 10 fold of normal males in field cages could suppress F-1 population 80.11 % and suppress F-2 population 80.32 % when compare with the control. This technique may be applied to delay and/or reduce seasonal increase of brown planthopper.

  7. Expression of a pathogen-induced cysteine protease (AdCP) in tapetum results in male sterility in transgenic tobacco.

    PubMed

    Shukla, Pawan; Singh, Naveen Kumar; Kumar, Dilip; Vijayan, Sambasivam; Ahmed, Israr; Kirti, Pulugurtha Bharadwaja

    2014-06-01

    Usable male sterility systems have immense potential in developing hybrid varieties in crop plants, which can also be used as a biological safety containment to prevent horizontal transgene flow. Barnase-Barstar system developed earlier was the first approach to engineer male sterility in plants. In an analogous situation, we have evolved a system of inducing pollen abortion and male sterility in transgenic tobacco by expressing a plant gene coding for a protein with known developmental function in contrast to the Barnase-Barstar system, which deploys genes of prokaryotic origin, i.e., from Bacillus amyloliquefaciens. We have used a plant pathogen-induced gene, cysteine protease for inducing male sterility. This gene was identified in the wild peanut, Arachis diogoi differentially expressed when it was challenged with the late leaf spot pathogen, Phaeoisariopsis personata. Arachis diogoi cysteine protease (AdCP) was expressed under the strong tapetum-specific promoter (TA29) and tobacco transformants were generated. Morphological and histological analysis of AdCP transgenic plants showed ablated tapetum and complete pollen abortion in three transgenic lines. Furthermore, transcript analysis displayed the expression of cysteine protease in these male sterile lines and the expression of the protein was identified in western blot analysis using its polyclonal antibody raised in the rabbit system.

  8. De Novo Assembly and Transcriptome Analysis of Wheat with Male Sterility Induced by the Chemical Hybridizing Agent SQ-1

    PubMed Central

    Zhang, Gaisheng; Ju, Lan; Zhang, Jiao; Yu, Yongang; Niu, Na; Wang, Junwei; Ma, Shoucai

    2015-01-01

    Wheat (Triticum aestivum L.), one of the world’s most important food crops, is a strictly autogamous (self-pollinating) species with exclusively perfect flowers. Male sterility induced by chemical hybridizing agents has increasingly attracted attention as a tool for hybrid seed production in wheat; however, the molecular mechanisms of male sterility induced by the agent SQ-1 remain poorly understood due to limited whole transcriptome data. Therefore, a comparative analysis of wheat anther transcriptomes for male fertile wheat and SQ-1–induced male sterile wheat was carried out using next-generation sequencing technology. In all, 42,634,123 sequence reads were generated and were assembled into 82,356 high-quality unigenes with an average length of 724 bp. Of these, 1,088 unigenes were significantly differentially expressed in the fertile and sterile wheat anthers, including 643 up-regulated unigenes and 445 down-regulated unigenes. The differentially expressed unigenes with functional annotations were mapped onto 60 pathways using the Kyoto Encyclopedia of Genes and Genomes database. They were mainly involved in coding for the components of ribosomes, photosynthesis, respiration, purine and pyrimidine metabolism, amino acid metabolism, glutathione metabolism, RNA transport and signal transduction, reactive oxygen species metabolism, mRNA surveillance pathways, protein processing in the endoplasmic reticulum, protein export, and ubiquitin-mediated proteolysis. This study is the first to provide a systematic overview comparing wheat anther transcriptomes of male fertile wheat with those of SQ-1–induced male sterile wheat and is a valuable source of data for future research in SQ-1–induced wheat male sterility. PMID:25898130

  9. Involvement of Prostaglandins and Histamine in Radiation-Induced Temperature Responses in Rats

    DTIC Science & Technology

    1990-01-01

    saline. PGE2 and PGD2 were stored at -20"C and central administration of naloxone, a p- receptor antagonist, were dissolved in sterile saline before the...cimetidine are specific HI and H2 receptor antagonists. re- nized only PGE2 - and radiation-induced hNperthermia in- spectively. Mepyramine antagonized...administration of PGE2 and PGD2 induced hyper- and hy- quently release PGD2 as a major cyclooxygenase metabo- pothermia. respectively. Administration

  10. Postpartum Sterilization

    MedlinePlus

    ... How is postpartum sterilization performed? • What kind of anesthesia is used for postpartum sterilization? • How long does ... with stitches and a bandage. What kind of anesthesia is used for postpartum sterilization? Often, the type ...

  11. Xenotransplantation exposes the etiology of azoospermia factor (AZF) induced male sterility.

    PubMed

    Barr, Justinn; Gordon, Daniel; Schedl, Paul; Deshpande, Girish

    2015-03-01

    Ramathal et al. have employed an elegant xenotransplantation technique to study the fate of human induced pluripotent stem cells (hiPSCs) from fertile males and from males carrying Y chromosome deletions of the azoospermia factor (AZF) region. When placed in a mouse testis niche, hiPSCs from fertile males differentiate into germ cell-like cells (GCLCs). Highlighting the crucial role of cell autonomous factors in male sterility, hiPSCs derived from azoospermic males prove to be less successful under similar circumstances. Their studies argue that the agametic "Sertoli cell only" phenotype of two of the AZF deletions likely arises from a defect in the maintenance of germline stem cells (GSCs) rather than from a defect in their specification. These observations underscore the importance of the dialogue between the somatic niche and its inhabitant stem cells, and open up interesting questions concerning the functioning of the somatic niche and how it communicates to the GSCs. © 2015 WILEY Periodicals, Inc.

  12. Influence of sterilization on the mineralization of titanium implants induced by incubation in various biological model fluids.

    PubMed

    Serro, A P; Saramago, B

    2003-11-01

    The aim of this work was to investigate the effect of the sterilization processes on the mineralization of titanium implants induced by incubation in various biological model fluids. Titanium samples were submitted to the following sterilization processes used for implant materials: steam autoclaving, glow discharge Ar plasma treatment and gamma-irradiation. The modification of the treated surfaces was evaluated by contact angle determinations, X-ray photoelectron spectroscopy (XPS), laser profilometry and X-ray diffraction. The most significant modifications were detected on the wettability: while the samples treated with Ar plasma became highly hydrophilic (water contact angle approximately 0 degrees), gamma-irradiation and steam sterilization induced an increase in the hydrophobicity. After being sterilized, the samples were incubated for one week in three biological model fluids: Hanks' Balanced Salt Solution, Kokubo's simulated body fluid (SBF) and a fluid, designated by SBF0, with the same composition of SBF but without buffer TRIS. The level of mineralization of the incubated Ti samples, assessed by dynamic contact angle analysis, scanning electron microscopy, electron dispersive spectroscopy and XPS, indicated that the early stages of mineralization are essentially independent of the sterilization method. In contrast, the incubating fluid plays a determinant role, SBFO being the most efficient medium for biomineralization of titanium.

  13. Treatment of Radiation-Induced Urethral Strictures.

    PubMed

    Hofer, Matthias D; Liu, Joceline S; Morey, Allen F

    2017-02-01

    Radiation therapy may result in urethral strictures from vascular damage. Most radiation-induced urethral strictures occur in the bulbomembranous junction, and urinary incontinence may result as a consequence of treatment. Radiation therapy may compromise reconstruction due to poor tissue healing and radionecrosis. Excision and primary anastomosis is the preferred urethroplasty technique for radiation-induced urethral stricture. Principles of posterior urethroplasty for trauma may be applied to the treatment of radiation-induced urethral strictures. Chronic management with suprapubic tube is an option based on patient comorbidities and preference.

  14. Cytological and comparative proteomic analyses on male sterility in Brassica napus L. induced by the chemical hybridization agent monosulphuron ester sodium

    USDA-ARS?s Scientific Manuscript database

    Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Monosulphuron ester sodium (MES), a new acetolactate synthase-inhibitor herbicide belonging to the sulphonylurea family, has been developed as an effective CHA to induce male sterility i...

  15. [Inheritance of reversions to male fertility in male-sterile sorghum hybrids with 9E cytoplasm male sterility induced by environmental conditions].

    PubMed

    Elkonin, L A; Gerashchenkov, G A; Domanina, I V; Rozhnova, N A

    2015-03-01

    sorghum hybrids in the 9E cytoplasm. These data demonstrate that methylation of nuclear genes in sterility-inducing cytoplasm may be one of mechanisms causing the CMS phenomenon.

  16. Raman spectral markers of collagen denaturation and hydration in human cortical bone tissue are affected by radiation sterilization and high cycle fatigue damage.

    PubMed

    Flanagan, Christopher D; Unal, Mustafa; Akkus, Ozan; Rimnac, Clare M

    2017-11-01

    Thermal denaturation and monotonic mechanical damage alter the organic and water-related compartments of cortical bone. These changes can be detected using Raman spectroscopy. However, less is known regarding Raman sensitivity to detect the effects of cyclic fatigue damage and allograft sterilization doses of gamma radiation. To determine if Raman spectroscopic biomarkers of collagen denaturation and hydration are sensitive to the effects of (a) high cycle fatigue damage and (b) 25kGy irradiation. Unirradiated and gamma-radiation sterilized human cortical bone specimens previously tested in vitro under high-cycle (> 100,000 cycles) fatigue conditions at 15MPa, 25MPa, 35MPa, 45MPa, and 55MPa cyclic stress levels were studied. Cortical bone Raman spectral profiles from wavenumber ranges of 800-1750cm(-1) and 2700-3800cm(-1) were obtained and compared from: a) non-fatigue vs fatigue fracture sites and b) radiated vs. unirradiated states. Raman biomarker ratios 1670/1640 and 3220/2949, which reflect collagen denaturation and organic matrix (mainly collagen)-bound water, respectively, were assessed. One- and two-way ANOVA analyses were utilized to identify differences between groups along with interaction effects between cyclic fatigue and radiation-induced damage. Cyclic fatigue damage resulted in increases in collagen denaturation (1670/1640: 1.517 ± 0.043 vs 1.579 ± 0.021, p < 0.001) and organic matrix-bound water (3220/2949: 0.109 ± 0.012 vs 0.131 ± 0.008, p < 0.001). Organic matrix-bound water increased secondary to 25kGy irradiation (3220/2949: 0.105 ± 0.010 vs 0.1161 ± 0.009, p = 0.003). Organic matrix-bound water was correlated positively with collagen denaturation (r = 0.514, p < 0.001). Raman spectroscopy can detect the effects of cyclic fatigue damage and 25kGy irradiation via increases in organic matrix (mainly collagen)-bound water. A Raman measure of collagen denaturation was sensitive to cyclic fatigue damage but not 25kGy irradiation. Collagen

  17. Radiation-induced moyamoya syndrome

    SciTech Connect

    Desai, Snehal S.; Paulino, Arnold C. . E-mail: apaulino@tmh.tmc.edu; Mai, Wei Y.; Teh, Bin S.

    2006-07-15

    Purpose: The moyamoya syndrome is an uncommon late complication after radiotherapy (RT). Methods and Materials: A PubMed search of English-language articles, with radiation, radiotherapy, and moyamoya syndrome used as search key words, yielded 33 articles from 1967 to 2002. Results: The series included 54 patients with a median age at initial RT of 3.8 years (range, 0.4 to 47). Age at RT was less than 5 years in 56.3%, 5 to 10 years in 22.9%, 11 to 20 years in 8.3%, 21 to 30 years in 6.3%, 31 to 40 years in 2.1%, and 41 to 50 years in 4.2%. Fourteen of 54 patients (25.9%) were diagnosed with neurofibromatosis type 1 (NF-1). The most common tumor treated with RT was low-grade glioma in 37 tumors (68.5%) of which 29 were optic-pathway glioma. The average RT dose was 46.5 Gy (range, 22-120 Gy). For NF-1-positive patients, the average RT dose was 46.5 Gy, and for NF-1-negative patients, it was 58.1 Gy. The median latent period for development of moyamoya syndrome was 40 months after RT (range, 4-240). Radiation-induced moyamoya syndrome occurred in 27.7% of patients by 2 years, 53.2% of patients by 4 years, 74.5% of patients by 6 years, and 95.7% of patients by 12 years after RT. Conclusions: Patients who received RT to the parasellar region at a young age (<5 years) are the most susceptible to moyamoya syndrome. The incidence for moyamoya syndrome continues to increase with time, with half of cases occurring within 4 years of RT and 95% of cases occurring within 12 years. Patients with NF-1 have a lower radiation-dose threshold for development of moyamoya syndrome.

  18. Influence of molecular weight on the resistance of polylactide fibers by radiation sterilization

    SciTech Connect

    Horacek, I.; Kudlacek, L. . Dept. of Fibres and Textile Chemistry)

    1993-10-05

    The mechanical properties and in vitro degradability of poly(L-lactide) fibers with different average molecular weights, prepared by a dry spinning-hot drawing process from CHCl[sub 3] solutions, were studied in relation to the [gamma]-irradiation dose. In the range of molecular weight of 1.6--3.6 [times] 10[sup 5], no differences were found in the relative decrease of tensile strength after irradiation of 25 kGy. Changes of the elongation at break are discussed in terms of a network solution theory. In vitro degradation of the fibers is also discussed in network solution theory terms. Regardless of the courses of degradation curves, it may be stated that all prepared fibers could be sterilized by [gamma]-rays and the rate of degradation was not affected by the irradiation dose.

  19. Hypopharyngeal carcinoma after radiation for tuberculosis: radiation-induced carcinoma.

    PubMed

    van der Putten, Lisa; de Bree, Remco; Kuik, Dirk J; Rietveld, Derek H F; Langendijk, Johannes A; Leemans, C René

    2010-09-01

    Radiation may cause radiation-induced cancers after a long latency period. In a group of 111 patients surgically treated for hypopharyngeal carcinoma, patients previously treated with radiotherapy for tuberculosis in the neck were compared to patients without previous radiotherapy. Seven patients (7.4%) underwent radiotherapy (median age 15 years) and developed a hypopharyngeal carcinoma (median age 70 years, median latency period 54.4 year). Considering this long latency period and the localisation in the previous radiation field these tumours can be classified as potentially radiation-induced carcinomas. Patients with potentially radiation-induced carcinomas were significantly older when the hypopharyngeal carcinoma was diagnosed (p=0.048), were more frequently females (p=0.05) and had a worse 5-year regional control rate (p=0.048). When radiotherapy is considered in young patients the risk of induction of tumours has to be kept in mind. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Comparison of structural changes in skin and amnion tissue grafts for transplantation induced by gamma and electron beam irradiation for sterilization.

    PubMed

    Mrázová, H; Koller, J; Kubišová, K; Fujeríková, G; Klincová, E; Babál, P

    2016-06-01

    Sterilization is an important step in the preparation of biological material for transplantation. The aim of the study is to compare morphological changes in three types of biological tissues induced by different doses of gamma and electron beam radiation. Frozen biological tissues (porcine skin xenografts, human skin allografts and human amnion) were irradiated with different doses of gamma rays (12.5, 25, 35, 50 kGy) and electron beam (15, 25, 50 kGy). Not irradiated specimens served as controls. The tissue samples were then thawn and fixed in 10 % formalin, processed by routine paraffin technique and stained with hematoxylin and eosin, alcian blue at pH 2.5, orcein, periodic acid Schiff reaction, phosphotungstic acid hematoxylin, Sirius red and silver impregnation. The staining with hematoxylin and eosin showed vacuolar cytoplasmic changes of epidermal cells mainly in the samples of xenografts irradiated by the lowest doses of gamma and electron beam radiation. The staining with orcein revealed damage of fine elastic fibers in the xenograft dermis at the dose of 25 kGy of both radiation types. Disintegration of epithelial basement membrane, especially in the xenografts, was induced by the dose of 15 kGy of electron beam radiation. The silver impregnation disclosed nuclear chromatin condensation mainly in human amnion at the lowest doses of both radiation types and disintegration of the fine collagen fibers in the papillary dermis induced by the lowest dose of electron beam and by the higher doses of gamma radiation. Irradiation by both, gamma rays and the electron beam, causes similar changes on cells and extracellular matrix, with significant damage of the basement membrane and of the fine and elastic and collagen fibers in the papillary dermis, the last caused already by low dose electron beam radiation.

  1. Lead-induced oxidative damage in steriled seedlings of Nymphoides peltatum.

    PubMed

    Qiao, Xuqiang; Shi, Guoxin; Chen, Lin; Tian, Xiuli; Xu, Xiaoying

    2013-07-01

    The effects of increasing concentrations of lead (Pb) on Pb accumulation and its influence on nutrient elements, malondialdehyde (MDA) content, generation of superoxide anion (O2(-·)), hydrogen peroxide (H2O2) content, antioxidant enzymes activities, soluble protein, and photosynthetic pigment, as well as chloroplast ultrastructure in steriled seedlings of Nymphoides peltata (S. G. Gmel.) Kuntze were investigated in order to understand Pb-induced toxicity. The accumulation of Pb was found to increase in a concentration-dependent manner. Nutrient elements (Ca, K, Fe, Mn, and Mo) were also affected. MDA content and O2(-·) generation rate increased progressively, while H2O2 content first boosted up at a low Pb concentration of 12.5 μM but then declined. Guaiacol peroxidase and catalase activities increased alternately, while superoxide dismutase activity gradually fell. Negative correlations were found between Pb and soluble protein and photosynthetic pigment. Moreover, Pb exposure resulted in a significant damage of chloroplasts. Taken together, these findings supported the hypothesis that Nymphoides peltatum underwent oxidative stress induced by Pb. In addition, both the disorder of nutrient elements and the damage to the ultrastructure of chloroplasts were indicative of general disarray in the cellular functions exerted by Pb.

  2. Factors that modify radiation-induced carcinogenesis.

    PubMed

    Kennedy, Ann R

    2009-11-01

    It is known that numerous factors can influence radiation carcinogenesis in animals; these factors include the specific characteristics of the radiation (radiation type and dose, dose-rate, dose-fractionation, dose distribution, etc.) as well as many other contributing elements that are not specific to the radiation exposure, such as animal genetic characteristics and age, the environment of the animal, dietary factors and whether specific modifying agents for radiation carcinogenesis have been utilized in the studies. This overview focuses on the modifying factors for radiation carcinogenesis, in both in vivo and in vitro systems, and includes a discussion of agents that enhance (e.g., promoting agents) or suppress (e.g., cancer preventive agents) radiation-induced carcinogenesis. The agents that enhance or suppress radiation carcinogenesis in experimental model systems have been shown to lead to effects equally as large as other known modifying factors for radiation-induced carcinogenesis (e.g., dose-rate, dose-fractionation, linear energy transfer). It is known that dietary factors play an important role in determining the yields of radiation-induced cancers in animal model systems, and it is likely that they also influence radiation-induced cancer risks in human populations.

  3. Radiation-induced genomic instability: radiation quality and dose response

    NASA Technical Reports Server (NTRS)

    Smith, Leslie E.; Nagar, Shruti; Kim, Grace J.; Morgan, William F.

    2003-01-01

    Genomic instability is a term used to describe a phenomenon that results in the accumulation of multiple changes required to convert a stable genome of a normal cell to an unstable genome characteristic of a tumor. There has been considerable recent debate concerning the importance of genomic instability in human cancer and its temporal occurrence in the carcinogenic process. Radiation is capable of inducing genomic instability in mammalian cells and instability is thought to be the driving force responsible for radiation carcinogenesis. Genomic instability is characterized by a large collection of diverse endpoints that include large-scale chromosomal rearrangements and aberrations, amplification of genetic material, aneuploidy, micronucleus formation, microsatellite instability, and gene mutation. The capacity of radiation to induce genomic instability depends to a large extent on radiation quality or linear energy transfer (LET) and dose. There appears to be a low dose threshold effect with low LET, beyond which no additional genomic instability is induced. Low doses of both high and low LET radiation are capable of inducing this phenomenon. This report reviews data concerning dose rate effects of high and low LET radiation and their capacity to induce genomic instability assayed by chromosomal aberrations, delayed lethal mutations, micronuclei and apoptosis.

  4. Radiation-induced genomic instability: radiation quality and dose response

    NASA Technical Reports Server (NTRS)

    Smith, Leslie E.; Nagar, Shruti; Kim, Grace J.; Morgan, William F.

    2003-01-01

    Genomic instability is a term used to describe a phenomenon that results in the accumulation of multiple changes required to convert a stable genome of a normal cell to an unstable genome characteristic of a tumor. There has been considerable recent debate concerning the importance of genomic instability in human cancer and its temporal occurrence in the carcinogenic process. Radiation is capable of inducing genomic instability in mammalian cells and instability is thought to be the driving force responsible for radiation carcinogenesis. Genomic instability is characterized by a large collection of diverse endpoints that include large-scale chromosomal rearrangements and aberrations, amplification of genetic material, aneuploidy, micronucleus formation, microsatellite instability, and gene mutation. The capacity of radiation to induce genomic instability depends to a large extent on radiation quality or linear energy transfer (LET) and dose. There appears to be a low dose threshold effect with low LET, beyond which no additional genomic instability is induced. Low doses of both high and low LET radiation are capable of inducing this phenomenon. This report reviews data concerning dose rate effects of high and low LET radiation and their capacity to induce genomic instability assayed by chromosomal aberrations, delayed lethal mutations, micronuclei and apoptosis.

  5. Radiation-induced gene responses

    SciTech Connect

    Woloschak, G.E.; Paunesku, T.; Shearin-Jones, P.; Oryhon, J.

    1996-12-31

    In the process of identifying genes that are differentially regulated in cells exposed to ultraviolet radiation (UV), we identified a transcript that was repressed following the exposure of cells to a combination of UV and salicylate, a known inhibitor of NF-kappaB. Sequencing this band determined that it has identify to lactate dehydrogenase, and Northern blots confirmed the initial expression pattern. Analysis of the sequence of the LDH 5` region established the presence of NF-kappaB, Sp1, and two Ap-2 elements; two partial AP- 1; one partial RE, and two halves of E-UV elements were also found. Electromobility shift assays were then performed for the AP-1, NF- kappaB, and E-UV elements. These experiments revealed that binding to NF-kappaB was induced by UV but repressed with salicylic acid; UV did not affect AP-1 binding, but salicylic acid inhibited it alone or following UV exposure; and E-UV binding was repressed by UV, and salicylic acid had little effect. Since the binding of no single element correlated with the expression pattern of LDH, it is likely that multiple elements govern UV/salicylate-mediated expression.

  6. Necrosis-Induced Sterile Inflammation Mediated by Interleukin-1α in Retinal Pigment Epithelial Cells

    PubMed Central

    Liu, Yang; Kimura, Kazuhiro; Orita, Tomoko; Sonoda, Koh-Hei

    2015-01-01

    Endogenous danger signals released from necrotic cells contribute to retinal inflammation. We have now investigated the effects of necrotic cell extracts prepared from ARPE-19 human retinal pigment epithelial cells (ANCE) on the release of proinflammatory cytokines and chemokines by healthy ARPE-19 cells. ANCE were prepared by subjection of ARPE-19 cells to freeze-thaw cycles. The release of various cytokines and chemokines from ARPE-19 cells was measured with a multiplex assay system or enzyme-linked immunosorbent assays. The expression of interleukin (IL)–1α and the phosphorylation and degradation of the endogenous nuclear factor–κB (NF-κB) inhibitor IκB-α were examined by immunoblot analysis. Among the various cytokines and chemokines examined, we found that ANCE markedly stimulated the release of the proinflammatory cytokine IL-6 and the chemokines IL-8 and monocyte chemoattractant protein (MCP)–1 by ARPE-19 cells. ANCE-induced IL-6, IL-8, and MCP-1 release was inhibited by IL-1 receptor antagonist and by an IKK2 inhibitor (a blocker of NF-κB signaling) in a concentration-dependent manner, but was not affected by a pan-caspase inhibitor (Z-VAD-FMK). Recombinant IL-1α also induced the secretion of IL-6, IL-8, and MCP-1 from ARPE-19 cells, and IL-1α was detected in ANCE. Furthermore, ANCE induced the phosphorylation and degradation of IκB-α in ARPE-19 cells. Our findings thus suggest that IL-1α is an important danger signal that is released from necrotic retinal pigment epithelial cells and triggers proinflammatory cytokine and chemokine secretion from intact cells in a manner dependent on NF-κB signaling. IL-1α is therefore a potential therapeutic target for amelioration of sterile inflammation in the retina. PMID:26641100

  7. Substantiation of 25 kGy radiation sterilization dose for banked air dried amniotic membrane and evaluation of personnel skill in influencing finished product bioburden.

    PubMed

    Marsit, Nagi; Dwejen, Samira; Saad, Ibrahim; Abdalla, Sedigh; Shaab, Arej; Salem, Salma; Khanfas, Enas; Hasan, Anas; Mansur, Mohamed; Abdul Sammad, Mohamed

    2014-12-01

    Preparation of amniotic membrane (AM) by air drying method followed by radiation sterilization is simple and valuable approach; sterility and quality of the final AM product are depending on the quality management system at the tissue bank. Validation and substantiation of radiation sterilization dose (RSD) for tissue allografts is an essential step for the development and validation of the standard operating procedures (SOP). Application of SOP is perfectly relying on trained staff. Skills differences among personnel involved in AM preparation could have an effect on microbiological quality of the finished product and subsequently on the RSD required. AM were processed by four different couples of the tissue bank technicians. The AM grafts were randomly selected and subjected to bioburden test to validate and substantiate the 25 kGy RSD. Bioburden test for AM grafts were also useful to evaluate the skill of the tissue bank technicians and thus, to validate the current SOP for air dried AM. Moreover, the effect of placental source on bioburden counts on AM grafts was assessed. Substantiation of the 25 kGy RSD at a sterility assurance level of 10(-1), and sample item portion = 1, was carried out using Method VD max (25) of the International Organization for Standardization, document no. 11137-2 (ISO in Sterilization of healthcare products-radiation-part 2: establishing the sterilization dose, Method VDmax-substantiation of 25 kGy or 15 kGy as the sterilization dose, International Standard Organization, 2006). The results showed that there were no significant differences in the bioburdens of the four batches (α = 1 %), this means no significant differences in the skill of the four couples of the tissue bank technicians in terms of their ability to process AM according to the air dried AM SOP. The 25 kGy RSD was validated and substantiated as a valid sterilization dose for the AM prepared with the current established SOP at the Biotechnology Research Center

  8. Effect of ionizing radiation dose, temperature, and atmosphere on the survival of Salmonella typhimurium in sterile, mechanically deboned chicken meat

    SciTech Connect

    Thayer, D.W.; Boyd, G. )

    1991-02-01

    The response to gamma radiation (0 to 3.60 kGy; 100 krad = 1 kGy) of Salmonella typhimurium was tested in otherwise sterile, mechanically deboned chicken meat (MDCM) in the absence of competing microflora. Response was determined at temperatures of -20 to +20 C and when the MDCM was packaged in vacuum or in the presence of air. A central composite response-surface design was used to test the response of the pathogen to the treatments in a single experiment. Predictive equations were developed from the analyses of variances of the resulting data. The accuracy of each predictive equation was tested by further studies of the effects of gamma radiation on S. typhimurium in the presence or absence of air at -20, 0, and +20 C. All data were then analyzed to refine the predictive equations further. Both the original and the refined equations adequately predicted the response of S. typhimurium in MDCM to gamma radiation doses up to 3.60 kGy in the presence of air or in vacuo. Gamma irradiation was significantly more lethal for S. typhimurium in the presence of air and at higher temperatures. The final equations predict a reduction in the number of surviving Salmonella in MDCM irradiated to 1.50 kGy at -20 C of 2.53 logs in air or 2.12 logs if irradiated in vacuum. If the contaminated MDCM were to receive a dose of 3.0 kGy at -20 C in air, the number of Salmonella would be decreased by 4.78 logs, and if irradiated in vacuum, by 4.29 logs.

  9. Bulbophyllum sterile petroleum ether fraction induces apoptosis in vitro and ameliorates tumor progression in vivo.

    PubMed

    Biswas, Subhankar; Pardeshi, Rashmi; Reddy, Neetinkumar D; Shoja, Muhammed Haneefa; Nayak, Pawan G; Setty, M Manjunath; Pai, K Sreedhara R

    2016-12-01

    Orchids of the genus Bulbophyllum have been reported to possess antitumor activity. Present study investigated the possible antitumor activity of the active fraction of bulb and root of Bulbophyllum sterile. Alcoholic extract along with petroleum ether, dichloromethane and ethyl acetate fractions were subjected to SRB assay in HCT-116, MDA-MB-231 and A549 cell lines. The active fractions were further evaluated for apoptosis, expression of apoptotic signaling proteins, comet assay and cell cycle analysis. Furthermore, they were assessed for in vivo antitumor activity in Ehrlich ascites carcinoma model. Petroleum fraction of bulbs (PFB) and roots (PFR) was found to be most active in HCT-116 cell lines with IC50 value of 94.2±6.0 and 75.7±9.8, respectively. Apoptosis was evident from acridine orange/ethidium bromide staining along with the expression of phospho-p53 and phospho-Bad. Both PFB and PFR arrested G2/M phase of the cell cycle with 32.6% and 49.4% arrest, respectively compared to 17.5% arrest with control. An increase in mean life span and hepatic antioxidant levels was observed with PFB and PFR treatment in EAC inoculated mice. The results suggested that the active fractions of bulbs and roots possess anticancer activity likely by inducing apoptosis through phospho-p53 dependent pathway. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Radiation-induced thyroid disease

    SciTech Connect

    Maxon, H.R.

    1985-09-01

    Ionizing radiation has been demonstrated to result in a number of changes in the human thyroid gland. At lower radiation dose levels (between 10 and 1500 rads), benign and malignant neoplasms appear to be the dominant effect, whereas at higher dose levels functional changes and thyroiditis become more prevalent. In all instances, the likelihood of the effect is related to the amount and type of radiation exposure, time since exposure, and host factors such as age, sex, and heredity. The author's current approach to the evaluation of patients with past external radiation therapy to the thyroid is discussed. The use of prophylactic thyroxine (T4) therapy is controversial. While T4 therapy may not be useful in preventing carcinogenesis when instituted many years after radiation exposure, theoretically T4 may block TSH secretion and stimulation of damaged cells to undergo malignant transformation when instituted soon after radiation exposure.

  11. Physico-chemical aspects of the drugs radiation sterilization in commercial packing (applied scientific problems of radiation pharmaceutical chemistry)

    SciTech Connect

    Safarov, S.A.

    1993-12-31

    The results of studies on the simultaneous radiosterilization of direct and bifurcational trachea prostheses made of silicon-organic rubber of soft elastic consistency, with polyethylenterephthalate and polyamid cuffs, and radiation chemical grafting of polymeric layer and linking with functional groups of the graft sulfanilamide and antibiotics layer are discussed. Radiopharmaceuticals are also described.

  12. N2O induces mitotic polyploidization in anther somatic cells and restores fertility in sterile interspecific hybrid lilies

    PubMed Central

    Nukui, Shotarou; Kitamura, Satomi; Hioki, Tomoyo; Ootsuka, Hideaki; Miyoshi, Kazumitsu; Satou, Takao; Takatori, Yuka; Oomiya, Tomo; Okazaki, Keiichi

    2011-01-01

    Fertile plants undergoing male gametogenesis can be treated with nitrous oxide (N2O) gas to obtain 2n male gametes. N2O treatment is also expected to restore the fertility of interspecific hybrids through meiotic restitution or mitotic amphidiploidization. However, this technique has few applications to date, and it is un-known how N2O treatment restores fertility in sterile hybrids. To establish optimal N2O treatment conditions and determine its cytological mechanism of action, we treated various sized floral buds with N2O gas at different anther developmental stages from fertile and sterile hybrid lilies. N2O treatment using the optimal 1–4 mm floral buds induced mitotic polyploidization of male archesporial cells to produce 2n pollen in fertile hybrid lilies. In sterile hybrid lilies, N2O treatment doubled the chromosome number in male archesporial cells followed by homologous chromosome pairing and normal meiosis in pollen mother cells (PMC), resulting in restoration of pollen fertility. Backcrossing the resultant fertile pollen to Lilium × formolongi produced many triploid BC1 plants. Thus N2O treatment at the archesporial cell proliferating stage effectively overcame pollen sterility in hybrid lilies, resulting in fertile, 2n pollen grains that could produce progeny. The procedure presented here will promote interspecific or interploidy hybridization of lilies. PMID:23136469

  13. Reversible Sterilization

    ERIC Educational Resources Information Center

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  14. Reversible Sterilization

    ERIC Educational Resources Information Center

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  15. Effect of UV radiation on a thermostable superoxide dismutase purified from a thermophilic bacterium isolated from a sterilization drying oven.

    PubMed

    Monsalves, María T; Amenábar, Maximiliano J; Ollivet-Besson, Gabriela P; Blamey, Jenny M

    2013-07-01

    A thermostable superoxide dismutase from a thermophilic bacterium, called Geobacillus wiegeli (GWE1), isolated from the interior of a sterilization drying oven, was purified by anion-exchange and molecular size-exclusion liquid chromatography. On the basis of SDS-PAGE, the purified enzyme was found to be homogeneous and showed an estimated subunit molecular mass of 23.9 kDa. The holoenzyme is a homotetramer of 97.3 kDa. Superoxide dismutase exhibited maximal activity at pH 8.5 and at temperature around 60 ºC. The enzyme was thermostable maintaining 50% of its activity even after 4.5 hours incubation at 60 ºC and more than 70% of its activity after 30 min at 80 ºC. When the microorganism was irradiated with UVA, an increase in the specific activity of superoxide dismutase was observed which was correlated with decreasing levels of anion superoxide, indicating the direct involvement of this enzyme in the capture of reactive oxygen species. This study reports the effects of UV radiation on a superoxide dismutase from a thermophilic bacterium isolated from an anthropogenic environment.

  16. Designing tragacanth gum based sterile hydrogel by radiation method for use in drug delivery and wound dressing applications.

    PubMed

    Singh, Baljit; Varshney, Lalit; Francis, Sanju; Rajneesh

    2016-07-01

    Present article discusses synthesis and characterization of the sterile and pure hydrogel wound dressings which were prepared through radiation method by using polyvinyl alcohol (PVA), tragacanth gum (TG) and sodium alginate (SA). The polymer films were characterized by SEM, Cryo-SEM, FTIR, solid state C(13) NMR and XRD, TGA, and DSC. Some important biological properties such as O2 permeability, water vapor transmission rate, microbial permeability, haemolysis, thrombogenic behavior, antioxidant activity, bio-adhesion and mechanical properties were also studied. The hydrogel film showed thrombogenicity (82.43±1.54%), haemolysis (0.83±0.09%), oxygen permeability (6.433±0.058mg/L) and water vapor permeability (197.39±25.34g/m(2)/day). Hydrogel films were found biocompatible and impermeable to microbes. The release of antibiotic drug moxifloxacin occurred through non-Fickian mechanism and release profile was best fitted in Hixson-Crowell model for drug release. Overall, these results indicate the suitability of these hydrogels in wound dressing applications.

  17. Radiation-induced lung injury

    SciTech Connect

    Rosiello, R.A.; Merrill, W.W. )

    1990-03-01

    The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

  18. Radiation-induced accelerated coronary arteriosclerosis

    SciTech Connect

    Mittal, B.; Deutsch, M.; Thompson, M.; Dameshek, H.L.

    1986-07-01

    There is a paucity of information on radiation-induced coronary heart disease. A young patient with myocardial infarction following mediastinal irradiation is described. The role of radiotherapy and chemotherapy on the subsequent development of coronary heart disease is discussed.

  19. Gaseous mercury emissions from unsterilized and sterilized soils: the effect of temperature and UV radiation.

    PubMed

    Choi, Hyun-Deok; Holsen, Thomas M

    2009-05-01

    Mercury (Hg) emissions from the soils taken from two different sites (deciduous and coniferous forests) in the Adirondacks were measured in outdoor and laboratory experiments. Some of the soil samples were irradiated to eliminate biological activity. The result from the outdoor measurements with different soils suggests the Hg emission from the soils is partly limited by fallen leaves covering the soils which helps maintain relatively high soil moisture and limits the amount of heat and solar radiation reaching the soil surface. In laboratory experiments exposure to UV-A (365 nm) had no significant effect on the Hg emissions while the Hg emissions increased dramatically during exposure to UV-B (302 nm) light suggesting UV-B directly reduced soil-associated Hg. Overall these results indicate that for these soils biotic processes have a relatively constant and smaller influence on the Hg emission from the soil than the more variable abiotic processes.

  20. Ultraviolet radiation induced discharge laser

    DOEpatents

    Gilson, Verle A.; Schriever, Richard L.; Shearer, James W.

    1978-01-01

    An ultraviolet radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

  1. Molecular pathways: radiation-induced cognitive impairment.

    PubMed

    Greene-Schloesser, Dana; Moore, Elizabeth; Robbins, Mike E

    2013-05-01

    Each year, approximately 200,000 patients in the United States will receive partial- or whole-brain irradiation for the treatment of primary or metastatic brain cancer. Early and delayed radiation effects are transient and reversible with modern therapeutic standards; yet, late radiation effects (≥6 months postirradiation) remain a significant risk, resulting in progressive cognitive impairment. These risks include functional deficits in memory, attention, and executive function that severely affect the patient's quality of life. The mechanisms underlying radiation-induced cognitive impairment remain ill defined. Classically, radiation-induced alterations in vascular and neuroinflammatory glial cell clonogenic populations were hypothesized to be responsible for radiation-induced brain injury. Recently, preclinical studies have focused on the hippocampus, one of two sites of adult neurogenesis within the brain, which plays an important role in learning and memory. Radiation ablates hippocampal neurogenesis, alters neuronal function, and induces neuroinflammation. Neuronal stem cells implanted into the hippocampus prevent the decrease in neurogenesis and improve cognition after irradiation. Clinically prescribed drugs, including PPARα and PPARγ agonists, as well as RAS blockers, prevent radiation-induced neuroinflammation and cognitive impairment independent of improved neurogenesis. Translating these exciting findings to the clinic offers the promise of improving the quality of life of brain tumor patients who receive radiotherapy. ©2013 AACR.

  2. Radiation-induced sarcoma of the thyroid

    SciTech Connect

    Griem, K.L.; Robb, P.K.; Caldarelli, D.D.; Templeton, A.C. )

    1989-08-01

    A 23-year-old white man presented with a thyroid mass 12 years after receiving high-dose radiotherapy for a T2 and N1 lymphoepithelioma of the nasopharynx. Following subtotal thyroidectomy, a histopathologic examination revealed liposarcoma of the thyroid gland. The relationship between sarcomas and irradiation is described and Cahan and colleagues' criteria for radiation-induced sarcomas are reviewed. To our knowledge, we are presenting the first such case of a radiation-induced sarcoma of the thyroid gland.

  3. Role of the Nalp3 inflammasome in acetaminophen-induced sterile inflammation and liver injury

    SciTech Connect

    Williams, C. David; Antoine, Daniel J.; Shaw, Patrick J.; Benson, Craig; Farhood, Anwar; Williams, Dominic P.; Kanneganti, Thirumala-Devi; Park, B. Kevin; Jaeschke, Hartmut

    2011-05-01

    Acetaminophen (APAP) overdose is the leading cause of acute liver failure in the US and UK. Recent studies implied that APAP-induced injury is partially mediated by interleukin-1{beta} (IL-1{beta}), which can activate and recruit neutrophils, exacerbating injury. Mature IL-1{beta} is formed by caspase-1, dependent on inflammasome activation. The objective of this invetstigation was to evaluate the role of the Nalp3 inflammasome on release of damage associated molecular patterns (DAMPs), hepatic neutrophil accumulation and liver injury (ALT, necrosis) after APAP overdose. Mice deficient for each component of the Nalp3 inflammasome (caspase-1, ASC and Nalp3) were treated with 300 mg/kg APAP for 24 h; these mice had similar neutrophil recruitment and liver injury as APAP-treated C57Bl/6 wildtype animals. In addition, plasma levels of DAMPs (DNA fragments, keratin-18, hypo- and hyper-acetylated forms of high mobility group box-1 protein) were similarly elevated with no significant difference between wildtype and gene knockout mice. In addition, aspirin treatment, which has been postulated to attenuate cytokine formation and the activation of the Nalp3 inflammasome after APAP, had no effect on release of DAMPs, hepatic neutrophil accumulation or liver injury. Together, these data confirm the release of DAMPs and a sterile inflammatory response after APAP overdose. However, as previously reported minor endogenous formation of IL-1{beta} and the activation of the Nalp3 inflammasome have little impact on APAP hepatotoxicity. It appears that the Nalp3 inflammasome is not a promising therapeutic target to treat APAP overdose.

  4. A live-attenuated Zika virus vaccine candidate induces sterilizing immunity in mouse models.

    PubMed

    Shan, Chao; Muruato, Antonio E; Nunes, Bruno T D; Luo, Huanle; Xie, Xuping; Medeiros, Daniele B A; Wakamiya, Maki; Tesh, Robert B; Barrett, Alan D; Wang, Tian; Weaver, Scott C; Vasconcelos, Pedro F C; Rossi, Shannan L; Shi, Pei-Yong

    2017-06-01

    Zika virus (ZIKV) infection of pregnant women can cause a wide range of congenital abnormalities, including microcephaly, in the infant, a condition now collectively known as congenital ZIKV syndrome. A vaccine to prevent or significantly attenuate viremia in pregnant women who are residents of or travelers to epidemic or endemic regions is needed to avert congenital ZIKV syndrome, and might also help to suppress epidemic transmission. Here we report on a live-attenuated vaccine candidate that contains a 10-nucleotide deletion in the 3' untranslated region of the ZIKV genome (10-del ZIKV). The 10-del ZIKV is highly attenuated, immunogenic, and protective in type 1 interferon receptor-deficient A129 mice. Crucially, a single dose of 10-del ZIKV induced sterilizing immunity with a saturated neutralizing antibody titer, which no longer increased after challenge with an epidemic ZIKV, and completely prevented viremia. The immunized mice also developed a robust T cell response. Intracranial inoculation of 1-d-old immunocompetent CD-1 mice with 1 × 10(4) infectious focus units (IFU) of 10-del ZIKV caused no mortality, whereas infections with 10 IFU of wild-type ZIKV were lethal. Mechanistically, the attenuated virulence of 10-del ZIKV may be due to decreased viral RNA synthesis and increased sensitivity to type-1-interferon inhibition. The attenuated 10-del ZIKV was incapable of infecting mosquitoes after oral feeding of spiked-blood meals, representing an additional safety feature. Collectively, the safety and efficacy results suggest that further development of this promising, live-attenuated ZIKV vaccine candidate is warranted.

  5. Overexpression of phytosulfokine-α induces male sterility and cell growth by regulating cell wall development in Arabidopsis.

    PubMed

    Yu, Liangliang; Liu, Yan; Liu, Yumin; Li, Qiong; Tang, Guirong; Luo, Li

    2016-12-01

    Over-production of functional PSK-α in Arabidopsis caused increases in both plant cell growth and biomass and induced male sterility by regulating cell wall development. Phytosulfokine-α (PSK-α) is a novel disulfated pentapeptide hormone that is involved in promoting plant cell growth. Although a role for PSK-α in stimulating protoplast expansion has been suggested, how PSK-α regulates cell growth in planta remains poorly understood. In this study, we found that overexpression of the normal PSK-α precursor gene AtPSK4, which resulted in high levels of PSK-α, caused longer roots and larger leaves with enlarged cells. As expected, these changes were not observed in transgenic plants overexpressing mutated AtPSK4, which generated unsulfated PSK-α. These findings confirmed the role of PSK-α in promoting plant cell growth. Furthermore, we found that overexpressing AtPSK4, but not mutated AtPSK4, induced a phenotype of male sterility that resulted from the failure of fibrous cell wall development in the endothecium. In addition, overexpressing AtPSK4 enhanced expression of a number of genes encoding expansins, which are involved in cell wall loosening. Accordingly, in addition to its role in cell growth, we propose a novel function for PSK-α signaling in the modulation of plant male sterility via regulation of cell wall development.

  6. Radiation induced detwinning in nanotwinned Cu

    SciTech Connect

    Chen, Youxing; Wang, Haiyan; Kirk, Mark A.; Li, Meimei; Wang, Jian; Zhang, Xinghang

    2016-11-15

    Superior radiation tolerance has been experimentally examined in nanotwinned metals. The stability of nanotwinned structure under radiation is the key factor for advancing the application of nanotwinned metals for nuclear reactors. We thus performed in situ radiation tests for nanotwinned Cu with various twin thicknesses inside a transmission electron microscope. We found that there is a critical twin thickness (10 nm), below which, radiation induced detwinning is primarily accomplished through migration of incoherent twin boundaries. Lastly, detwinning is faster for thinner twins in this range, while thicker twins are more stable.

  7. Radiation-induced vaginal stenosis: current perspectives

    PubMed Central

    Morris, Lucinda; Do, Viet; Chard, Jennifer; Brand, Alison H

    2017-01-01

    Treatment of gynecological cancer commonly involves pelvic radiation therapy (RT) and/or brachytherapy. A commonly observed side effect of such treatment is radiation-induced vaginal stenosis (VS). This review analyzed the incidence, pathogenesis, clinical manifestation(s) and assessment and grading of radiation-induced VS. In addition, risk factors, prevention and treatment options and follow-up schedules are also discussed. The limited available literature on many of these aspects suggests that additional studies are required to more precisely determine the best management strategy of this prevalent group after RT. PMID:28496367

  8. Triptolide Mitigates Radiation-Induced Pulmonary Fibrosis.

    PubMed

    Yang, Shanmin; Zhang, Mei; Chen, Chun; Cao, Yongbin; Tian, Yeping; Guo, Yangsong; Zhang, Bingrong; Wang, Xiaohui; Yin, Liangjie; Zhang, Zhenhuan; O'Dell, Walter; Okunieff, Paul; Zhang, Lurong

    2015-11-01

    Triptolide (TPL) may mitigate radiation-induced late pulmonary side effects through its inhibition of global pro-inflammatory cytokines. In this study, we evaluated the effect of TPL in C57BL/6 mice, the animals were exposed to radiation with vehicle (15 Gy), radiation with TPL (0.25 mg/kg i.v., twice weekly for 1, 2 and 3 months), radiation and celecoxib (CLX) (30 mg/kg) and sham irradiation. Cultured supernatant of irradiated RAW 264.7 and MLE-15 cells and lung lysate in different groups were enzyme-linked immunosorbent assays at 33 h. Respiratory rate, pulmonary compliance and pulmonary density were measured at 5 months in all groups. The groups exposed to radiation with vehicle and radiation with TPL exhibited significant differences in respiratory rate and pulmonary compliance (480 ± 75/min vs. 378 ± 76/min; 0.6 ± 0.1 ml/cm H2O/p kg vs. 0.9 ± 0.2 ml/cm H2O/p kg). Seventeen cytokines were significantly reduced in the lung lysate of the radiation exposure with TPL group at 5 months compared to that of the radiation with vehicle group, including profibrotic cytokines implicated in pulmonary fibrosis, such as IL-1β, TGF- β1 and IL-13. The radiation exposure with TPL mice exhibited a 41% reduction of pulmonary density and a 25% reduction of hydroxyproline in the lung, compared to that of radiation with vehicle mice. The trichrome-stained area of fibrotic foci and pathological scaling in sections of the mice treated with radiation and TPL mice were significantly less than those of the radiation with vehicle-treated group. In addition, the radiation with TPL-treated mice exhibited a trend of improved survival rate compared to that of the radiation with vehicle-treated mice at 5 months (83% vs. 53%). Three radiation-induced profibrotic cytokines in the radiation with vehicle-treated group were significantly reduced by TPL treatment, and this partly contributed to the trend of improved survival rate and pulmonary density and function and the decreased severity of

  9. Radiation-induced instability and its relation to radiation carcinogenesis

    NASA Technical Reports Server (NTRS)

    Ullrich, R. L.; Ponnaiya, B.

    1998-01-01

    PURPOSE: A model that identifies radiation-induced genetic instability as the earliest cellular event in the multi-step sequence leading to radiation-induced cancer was previously proposed. In this paper ongoing experiments are discussed which are designed to test this model and its predictions in mouse mammary epithelial cells. RESULTS: Several lines of evidence are presented that appear to support this model: first, the development of delayed mutations in p53 following irradiation in altered growth variants; secondly, the high frequencies for the induction of both instability and transformation following irradiation in mammary epithelial cells; and finally, the demonstration that susceptibility to the induction of cytogenetic instability is a heritable trait that correlates with susceptibility to transformation and radiation-induced mammary cancer. Mice resistant to transformation and mammary cancer development are also resistant to the development of instability after irradiation. In contrast, mice sensitive to transformation and cancer are also sensitive to the development of cytogenetic instability. CONCLUSIONS: Data from this laboratory and from the studies cited above suggest a specific, and perhaps unique, role for radiation-induced instability as a critical early event associated with initiation of the carcinogenic process.

  10. Radiation-induced instability and its relation to radiation carcinogenesis

    NASA Technical Reports Server (NTRS)

    Ullrich, R. L.; Ponnaiya, B.

    1998-01-01

    PURPOSE: A model that identifies radiation-induced genetic instability as the earliest cellular event in the multi-step sequence leading to radiation-induced cancer was previously proposed. In this paper ongoing experiments are discussed which are designed to test this model and its predictions in mouse mammary epithelial cells. RESULTS: Several lines of evidence are presented that appear to support this model: first, the development of delayed mutations in p53 following irradiation in altered growth variants; secondly, the high frequencies for the induction of both instability and transformation following irradiation in mammary epithelial cells; and finally, the demonstration that susceptibility to the induction of cytogenetic instability is a heritable trait that correlates with susceptibility to transformation and radiation-induced mammary cancer. Mice resistant to transformation and mammary cancer development are also resistant to the development of instability after irradiation. In contrast, mice sensitive to transformation and cancer are also sensitive to the development of cytogenetic instability. CONCLUSIONS: Data from this laboratory and from the studies cited above suggest a specific, and perhaps unique, role for radiation-induced instability as a critical early event associated with initiation of the carcinogenic process.

  11. [Quantification of radiation-induced genetic risk].

    PubMed

    Ehling, U H

    1987-05-01

    Associated with technical advances of our civilization is a radiation- and chemically-induced increase in the germ cell mutation rate in man. This would result in an increase in the frequency of genetic diseases and would be detrimental to future generations. It is the duty of our generation to keep this risk as low as possible. The estimation of the radiation-induced genetic risk of human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage does not. The different methods to estimate the radiation-induced genetic risk will be discussed. The accuracy of the predicted results will be evaluated by a comparison with the observed incidence of dominant mutations in offspring born to radiation exposed survivors of the Hiroshima and Nagasaki atomic bombings. These methods will be used to predict the genetic damage from the fallout of the reactor accident at Chernobyl. For the exposure dose we used the upper limits of the mean effective life time equivalent dose from the fallout values in the Munich region. According to the direct method for the risk estimation we will expect for each 100 to 500 spontaneous dominant mutations one radiation-induced mutation in the first generation. With the indirect method we estimate a ratio of 100 dominant spontaneous mutations to one radiation-induced dominant mutation. The possibilities and the limitations of the different methods to estimate the genetic risk will be discussed. The discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized.

  12. Evaluation of potential induced radioactivity in medical products as a function of electron energy in electron beam sterilization

    NASA Astrophysics Data System (ADS)

    Smith, Mark A.

    2012-01-01

    Commercial sterilization of medical devices may be performed using electron beam irradiators at various electron energies. The potential for activating components of the devices has been discussed, with current standards stating that electron energy greater than 10 MeV requires assessment of potential induced radioactivity. This paper evaluates the potential for induced activity in medical products sterilized in electron beam as a function of the electron maximum energy. Monte Carlo simulation of a surrogate medical device was used to calculate photon and neutron fields resulting from electron irradiation, which were used to calculate concentrations for several radionuclides. The experiments confirmed that 10 MeV is a conservative assumption for limiting induced radioactivity. However, under the conditions as evaluated, which is a limited total quantity of metal in the material being irradiated and absent a limited number of elements; the amount of induced activity at 12 MeV could also be considered insignificant. The comparison of the sum-of-fractions to the US Nuclear Regulatory Commission exempt concentration limits is less than unity for all energies below 12.1 MeV, which suggests that there is minimal probability of significant induced activity at energies above the 10 MeV upper energy limit.

  13. Cytological and Comparative Proteomic Analyses on Male Sterility in Brassica napus L. Induced by the Chemical Hybridization Agent Monosulphuron Ester Sodium

    PubMed Central

    Li, Zhanjie; Cui, Jianmin; Hu, Shengwu; Zhao, Huixian; Chen, Mingshun

    2013-01-01

    Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Monosulphuron ester sodium (MES), a new acetolactate synthase-inhibitor herbicide belonging to the sulphonylurea family, has been developed as an effective CHA to induce male sterility in rapeseed (Brassica napus L.). To understand MES-induced male sterility in rapeseed better, comparative cytological and proteomic analyses were conducted in this study. Cytological analysis indicated that defective tapetal cells and abnormal microspores were gradually generated in the developing anthers of MES-treated plants at various development stages, resulting in unviable microspores and male sterility. A total of 141 differentially expressed proteins between the MES-treated and control plants were revealed, and 131 of them were further identified by MALDI-TOF/TOF MS. Most of these proteins decreased in abundance in tissues of MES-treated rapeseed plants, and only a few increased. Notably, some proteins were absent or induced in developing anthers after MES treatment. These proteins were involved in several processes that may be crucial for tapetum and microspore development. Down-regulation of these proteins may disrupt the coordination of developmental and metabolic processes, resulting in defective tapetum and abnormal microspores that lead to male sterility in MES-treated plants. Accordingly, a simple model of CHA-MES-induced male sterility in rapeseed was established. This study is the first cytological and dynamic proteomic investigation on CHA-MES-induced male sterility in rapeseed, and the results provide new insights into the molecular events of male sterility. PMID:24244648

  14. Cytological and comparative proteomic analyses on male sterility in Brassica napus L. induced by the chemical hybridization agent monosulphuron ester sodium.

    PubMed

    Cheng, Yufeng; Wang, Qian; Li, Zhanjie; Cui, Jianmin; Hu, Shengwu; Zhao, Huixian; Chen, Mingshun

    2013-01-01

    Male sterility induced by a chemical hybridization agent (CHA) is an important tool for utilizing crop heterosis. Monosulphuron ester sodium (MES), a new acetolactate synthase-inhibitor herbicide belonging to the sulphonylurea family, has been developed as an effective CHA to induce male sterility in rapeseed (Brassica napus L.). To understand MES-induced male sterility in rapeseed better, comparative cytological and proteomic analyses were conducted in this study. Cytological analysis indicated that defective tapetal cells and abnormal microspores were gradually generated in the developing anthers of MES-treated plants at various development stages, resulting in unviable microspores and male sterility. A total of 141 differentially expressed proteins between the MES-treated and control plants were revealed, and 131 of them were further identified by MALDI-TOF/TOF MS. Most of these proteins decreased in abundance in tissues of MES-treated rapeseed plants, and only a few increased. Notably, some proteins were absent or induced in developing anthers after MES treatment. These proteins were involved in several processes that may be crucial for tapetum and microspore development. Down-regulation of these proteins may disrupt the coordination of developmental and metabolic processes, resulting in defective tapetum and abnormal microspores that lead to male sterility in MES-treated plants. Accordingly, a simple model of CHA-MES-induced male sterility in rapeseed was established. This study is the first cytological and dynamic proteomic investigation on CHA-MES-induced male sterility in rapeseed, and the results provide new insights into the molecular events of male sterility.

  15. Fatal or harmless: extreme bistability induced by sterilizing, sexually transmitted pathogens.

    PubMed

    Berec, Luděk; Maxin, Daniel

    2013-02-01

    Models of sexually transmitted infections have become a fixture of mathematical epidemiology. A common attribute of all these models is treating reproduction and mating, and hence pathogen transmission, as uncoupled events. This is fine for humans, for example, where only a tiny fraction of sexual intercourses ends up with having a baby. But it can be a deficiency for animals in which mating and giving birth are tightly coupled, and mating thus mediates both reproduction and pathogen transmission. Here, we model dynamics of sterilizing, sexually transmitted infections in such animals, assuming structural consistency between the processes of reproduction and pathogen transmission. We show that highly sterilizing, sexually transmitted pathogens trigger bistability in the host population. In particular, the host population can end up in two extreme alternative states, disease-free persistence and pathogen-driven extinction, depending on its initial state. Given that sterilizing, sexually transmitted infections that affect animals are abundant, our results might implicate an effective pest control tactic that consists of releasing the corresponding pathogens, possibly after genetically enhancing their sterilization power.

  16. Specific panicle responses resulting from MSMA-induced straighthead sterility in rice

    USDA-ARS?s Scientific Manuscript database

    Straighthead is a physiological disorder of rice causing sterility. A particular characteristic of straighthead is panicles that remain upright because of the light weight of the unfilled grains and hulls which may be distorted into a crescent or parrot-beak shape. Monosodium acid methanearsonate (M...

  17. Radiation-induced Genomic Instability and Radiation Sensitivity

    SciTech Connect

    Varnum, Susan M.; Sowa, Marianne B.; Kim, Grace J.; Morgan, William F.

    2013-01-19

    The obvious relationships between reactive oxygen and nitrogen species, mitochondrial dysfunction, inflammatory type responses and reactive chemokines and cytokines suggests a general stress response induced by ionizing radiation most likely leads to the non-targeted effects described after radiation exposure. We argue that true bystander effects do not occur in the radiation therapy clinic. But there is no question that effects outside the target volume do occur. These “out of field effects” are considered very low dose effects in the context of therapy. So what are the implications of non-targeted effects on radiation sensitivity? The primary goal of therapy is to eradicate the tumor. Given the genetic diversity of the human population, lifestyle and environment factors it is likely some combination of these will influence patient outcome. Non-targeted effects may contribute to a greater or lesser extent. But consider the potential situation involving a partial body exposure due to a radiation accident or radiological terrorism. Non-targeted effects suggest that the tissue at risk for demonstrating possible detrimental effects of radiation exposure might be greater than the volume actually irradiated.

  18. Radiation Sterilization of Prototype Military Foods: Low-Temperature Irradiation of Codfish Cake, Corned Beef, and Pork Sausage 1

    PubMed Central

    Anellis, Abe; Berkowitz, D.; Swantak, W.; Strojan, C.

    1972-01-01

    “Screening” packs comprising 10 lots each of codfish cake, corned beef, and pork sausage, each lot containing about 106 spores of a different strain (five type A and five type B) of Clostridium botulinum per can, were irradiated at −30 ± 10 C with a series of increasing doses (20 replicate cans/dose) of 60Co gamma rays. The cans were incubated for 3 months at 30 C and examined for swelling, toxin, and recoverable botulinal cells. Based on the latter criterion of spoilage, median lethal dose (LD50) and D values were estimated for each strain in each food. The most resistant strain in codfish cake, corned beef, and pork sausage was, respectively, 53B, 77A, and 41B. There was no clear-cut trend in the comparative order of resistance between the two antigenic types among the three foods. LD50 values gave essentially the same order of resistances as the D values and may be used interchangeably with the latter for the 10 test organisms. “Clearance” packs consisting of the most resistant strain (about 107 spores/can) with its respective food were irradiated with a variety of doses at −30 ± 10 C, using 100 replicate cans/dose (about 109 spores/dose). These packs were incubated for 6 months at 30 C and assayed for the three types of spoilage. Based on recoverable cells, the experimental sterilizing doses (ESD) for codfish cake, corned beef, and pork sausage were 2.5< ESD ≤ 3.0, 2.0 < ESD ≤ 2.5, and 1.5 < ESD ≤ 2.0 Mrad, in that order. Assuming exponential spore death, the 12D values, or minimal radiation doses (MRD), were 3.24, 2.44, and 2.65 Mrad, respectively. Estimation of the MRD values by a method which assumes that spore death in the cans follows a normal distribution, yielded 3.09, 2.57, and 2.39 Mrad, respectively. Weibull analyis of the pooled 10-strain viable cell spoilage data of the screening packs for codfish cake or corned beef suggested that spore death in the cans follows a normal distribution yielded 3.09, 2.57, pooled data were not

  19. Epigenetics in radiation-induced fibrosis.

    PubMed

    Weigel, C; Schmezer, P; Plass, C; Popanda, O

    2015-04-23

    Radiotherapy is a major cancer treatment option but dose-limiting side effects such as late-onset fibrosis in the irradiated tissue severely impair quality of life in cancer survivors. Efforts to explain radiation-induced fibrosis, for example, by genetic variation remained largely inconclusive. Recently published molecular analyses on radiation response and fibrogenesis showed a prominent role of epigenetic gene regulation. This review summarizes the current knowledge on epigenetic modifications in fibrotic disease and radiation response, and it points out the important role for epigenetic mechanisms such as DNA methylation, microRNAs and histone modifications in the development of this disease. The synopsis illustrates the complexity of radiation-induced fibrosis and reveals the need for investigations to further unravel its molecular mechanisms. Importantly, epigenetic changes are long-term determinants of gene expression and can therefore support those mechanisms that induce and perpetuate fibrogenesis even in the absence of the initial damaging stimulus. Future work must comprise the interconnection of acute radiation response and long-lasting epigenetic effects in order to assess their role in late-onset radiation fibrosis. An improved understanding of the underlying biology is fundamental to better comprehend the origin of this disease and to improve both preventive and therapeutic strategies.

  20. Radiation induced conductivity in space dielectric materials

    SciTech Connect

    Hanna, R.; Paulmier, T. Belhaj, M.; Dirassen, B.; Molinie, P.; Payan, D.; Balcon, N.

    2014-01-21

    The radiation-induced conductivity of some polymers was described mainly in literature by a competition between ionization, trapping/detrapping, and recombination processes or by radiation assisted ageing mechanisms. Our aim is to revise the effect of the aforementioned mechanisms on the complex evolution of Teflon{sup ®} FEP under space representative ionizing radiation. Through the definition of a new experimental protocol, revealing the effect of radiation dose and relaxation time, we have been able to demonstrate that the trapping/recombination model devised in this study agrees correctly with the observed experimental phenomenology at qualitative level and allows describing very well the evolution of radiation induced conductivity with irradiation time (or received radiation dose). According to this model, the complex behavior observed on Teflon{sup ®} FEP may be basically ascribed to the competition between electron/hole pairs generation and recombination: electrons are deeply trapped and act as recombination centers for free holes. Relaxation effects have been characterized through successive irradiations steps and have been again well described with the defined model at qualitative level: recombination centers created by the irradiation induce long term alteration on the electric properties, especially the effective bulk conductivity. One-month relaxation does not allow a complete recovery of the material initial charging behavior.

  1. Imaging radiation-induced normal tissue injury.

    PubMed

    Robbins, Mike E; Brunso-Bechtold, Judy K; Peiffer, Ann M; Tsien, Christina I; Bailey, Janet E; Marks, Lawrence B

    2012-04-01

    Technological developments in radiation therapy and other cancer therapies have led to a progressive increase in five-year survival rates over the last few decades. Although acute effects have been largely minimized by both technical advances and medical interventions, late effects remain a concern. Indeed, the need to identify those individuals who will develop radiation-induced late effects, and to develop interventions to prevent or ameliorate these late effects is a critical area of radiobiology research. In the last two decades, preclinical studies have clearly established that late radiation injury can be prevented/ameliorated by pharmacological therapies aimed at modulating the cascade of events leading to the clinical expression of radiation-induced late effects. These insights have been accompanied by significant technological advances in imaging that are moving radiation oncology and normal tissue radiobiology from disciplines driven by anatomy and macrostructure to ones in which important quantitative functional, microstructural, and metabolic data can be noninvasively and serially determined. In the current article, we review use of positron emission tomography (PET), single photon emission tomography (SPECT), magnetic resonance (MR) imaging and MR spectroscopy to generate pathophysiological and functional data in the central nervous system, lung, and heart that offer the promise of, (1) identifying individuals who are at risk of developing radiation-induced late effects, and (2) monitoring the efficacy of interventions to prevent/ameliorate them.

  2. Radiation induced conductivity in space dielectric materials

    NASA Astrophysics Data System (ADS)

    Hanna, R.; Paulmier, T.; Molinie, P.; Belhaj, M.; Dirassen, B.; Payan, D.; Balcon, N.

    2014-01-01

    The radiation-induced conductivity of some polymers was described mainly in literature by a competition between ionization, trapping/detrapping, and recombination processes or by radiation assisted ageing mechanisms. Our aim is to revise the effect of the aforementioned mechanisms on the complex evolution of Teflon® FEP under space representative ionizing radiation. Through the definition of a new experimental protocol, revealing the effect of radiation dose and relaxation time, we have been able to demonstrate that the trapping/recombination model devised in this study agrees correctly with the observed experimental phenomenology at qualitative level and allows describing very well the evolution of radiation induced conductivity with irradiation time (or received radiation dose). According to this model, the complex behavior observed on Teflon® FEP may be basically ascribed to the competition between electron/hole pairs generation and recombination: electrons are deeply trapped and act as recombination centers for free holes. Relaxation effects have been characterized through successive irradiations steps and have been again well described with the defined model at qualitative level: recombination centers created by the irradiation induce long term alteration on the electric properties, especially the effective bulk conductivity. One-month relaxation does not allow a complete recovery of the material initial charging behavior.

  3. A report on radiation-induced gliomas

    SciTech Connect

    Salvati, M.; Artico, M.; Caruso, R.; Rocchi, G.; Orlando, E.R.; Nucci, F. )

    1991-01-15

    Radiation-induced gliomas are uncommon, with only 73 cases on record to date. The disease that most frequently occasioned radiation therapy has been acute lymphoblastic leukemia (ALL). Three more cases are added here, two after irradiation for ALL and one after irradiation for tinea capitis. In a review of the relevant literature, the authors stress the possibility that the ALL-glioma and the retinoblastoma-glioma links point to syndromes in their own right that may occur without radiation therapy.56 references.

  4. Radiation-induced intestinal pseudoobstruction

    SciTech Connect

    Perino, L.E.; Schuffler, M.D.; Mehta, S.J.; Everson, G.T.

    1986-10-01

    A case of intestinal pseudoobstruction occurring 30 yr after radiation therapy is described. Mechanical causes of obstruction were excluded by laparotomy. Histology of full-thickness sections of the small bowel revealed vascular ectasia and sclerosis, serosal fibrosis, neuronal proliferation within the submucosa, and degeneration of the muscle fibers of the circular layer of the muscularis propria. On the basis of the clinical and histologic findings we conclude that, in this patient, intestinal pseudoobstruction was due to muscular and neuronal injury from abdominal irradiation.

  5. Radiation-induced amorphization of intermetallic compounds

    NASA Astrophysics Data System (ADS)

    Lam, N. Q.; Sabochick, M. J.; Okamoto, P. R.

    1994-06-01

    In the present paper, important results of our recent computer simulation of radiation-induced amorphization in the ordered compounds CuTi and Cu4Ti3 are summarized. The energetic, structural, thermodynamic and mechanical responses of these intermetallics during chemical disordering, point-defect production and heating were simulated, using molecular dynamics and embedded-atom potentials. From the atomistic details obtained, the critical role of radiation-induced structural disorder in driving the crystalline-to-amorphous phase transformation is discussed.

  6. Radiation-induced valvular heart disease.

    PubMed

    Gujral, Dorothy M; Lloyd, Guy; Bhattacharyya, Sanjeev

    2016-02-15

    Radiation to the mediastinum is a key component of treatment with curative intent for a range of cancers including Hodgkin's lymphoma and breast cancer. Exposure to radiation is associated with a risk of radiation-induced heart valve damage characterised by valve fibrosis and calcification. There is a latent interval of 10-20 years between radiation exposure and development of clinically significant heart valve disease. Risk is related to radiation dose received, interval from exposure and use of concomitant chemotherapy. Long-term outlook and the risk of valve surgery are related to the effects of radiation on mediastinal structures including pulmonary fibrosis and pericardial constriction. Dose prediction models to predict the risk of heart valve disease in the future and newer radiation techniques to reduce the radiation dose to the heart are being developed. Surveillance strategies for this cohort of cancer survivors at risk of developing significant heart valve complications are required. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  7. Quercetin inhibits radiation-induced skin fibrosis.

    PubMed

    Horton, Jason A; Li, Fei; Chung, Eun Joo; Hudak, Kathryn; White, Ayla; Krausz, Kristopher; Gonzalez, Frank; Citrin, Deborah

    2013-08-01

    Radiation induced fibrosis of the skin is a late toxicity that may result in loss of function due to reduced range of motion and pain. The current study sought to determine if oral delivery of quercetin mitigates radiation-induced cutaneous injury. Female C3H/HeN mice were fed control chow or quercetin-formulated chow (1% by weight). The right hind leg was exposed to 35 Gy of X rays and the mice were followed serially to assess acute toxicity and hind leg extension. Tissue samples were collected for assessment of soluble collagen and tissue cytokines. Human and murine fibroblasts were subjected to clonogenic assays to determine the effects of quercetin on radiation response. Contractility of fibroblasts was assessed with a collagen contraction assay in the presence or absence of quercetin and transforming growth factor-β (TGF-β). Western blotting of proteins involved in fibroblast contractility and TGF-β signaling were performed. Quercetin treatment significantly reduced hind limb contracture, collagen accumulation and expression of TGF-β in irradiated skin. Quercetin had no effect on the radioresponse of fibroblasts or murine tumors, but was capable of reducing the contractility of fibroblasts in response to TGF-β, an effect that correlated with partial stabilization of phosphorylated cofilin. Quercetin is capable of mitigating radiation induced skin fibrosis and should be further explored as a therapy for radiation fibrosis.

  8. Quercetin Inhibits Radiation-Induced Skin Fibrosis

    PubMed Central

    Horton, Jason A.; Li, Fei; Chung, Eun Joo; Hudak, Kathryn; White, Ayla; Krausz, Kristopher; Gonzalez, Frank; Citrin, Deborah

    2013-01-01

    Radiation induced fibrosis of the skin is a late toxicity that may result in loss of function due to reduced range of motion and pain. The current study sought to determine if oral delivery of quercetin mitigates radiation-induced cutaneous injury. Female C3H/HeN mice were fed control chow or quercetin-formulated chow (1% by weight). The right hind leg was exposed to 35 Gy of X rays and the mice were followed serially to assess acute toxicity and hind leg extension. Tissue samples were collected for assessment of soluble collagen and tissue cytokines. Human and murine fibroblasts were subjected to clonogenic assays to determine the effects of quercetin on radiation response. Contractility of fibroblasts was assessed with a collagen contraction assay in the presence or absence of quercetin and transforming growth factor-β (TGF-β). Western blotting of proteins involved in fibroblast contractility and TGF-β signaling were performed. Quercetin treatment significantly reduced hind limb contracture, collagen accumulation and expression of TGF-β in irradiated skin. Quercetin had no effect on the radioresponse of fibroblasts or murine tumors, but was capable of reducing the contractility of fibroblasts in response to TGF-β, an effect that correlated with partial stabilization of phosphorylated cofilin. Quercetin is capable of mitigating radiation induced skin fibrosis and should be further explored as a therapy for radiation fibrosis. PMID:23819596

  9. Food irradiation and sterilization

    NASA Astrophysics Data System (ADS)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  10. Radiation-induced meningiomas in pediatric patients

    SciTech Connect

    Moss, S.D.; Rockswold, G.L.; Chou, S.N.; Yock, D.; Berger, M.S.

    1988-04-01

    Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature.

  11. Radiation-induced meningiomas in pediatric patients.

    PubMed

    Moss, S D; Rockswold, G L; Chou, S N; Yock, D; Berger, M S

    1988-04-01

    Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature.

  12. Radiation-induced mutations and plant breeding

    SciTech Connect

    Naqvi, S.H.M.

    1985-01-01

    Ionizing radiation could cause genetic changes in an organism and could modify gene linkages. The induction of mutation through radiation is random and the probability of getting the desired genetic change is low but can be increased by manipulating different parameters such as dose rate, physical conditions under which the material has been irradiated, etc. Induced mutations have been used as a supplement to conventional plant breeding, particularly for creating genetic variability for specific characters such as improved plant structure, pest and disease resistance, and desired changes in maturity period; more than 200 varieties of crop plants have been developed by this technique. The Pakistan Atomic Energy Commission has used this technique fruitfully to evolve better germplasm in cotton, rice, chickpea, wheat and mungbean; some of the mutants have become popular commercial varieties. This paper describes some uses of radiation induced mutations and the results achieved in Pakistan so far.

  13. Comparative transcriptome analysis reveals carbohydrate and lipid metabolism blocks in Brassica napus L. male sterility induced by the chemical hybridization agent monosulfuron ester sodium.

    PubMed

    Li, Zhanjie; Cheng, Yufeng; Cui, Jianmin; Zhang, Peipei; Zhao, Huixian; Hu, Shengwu

    2015-03-17

    Chemical hybridization agents (CHAs) are often used to induce male sterility for the production of hybrid seeds. We previously discovered that monosulfuron ester sodium (MES), an acetolactate synthase (ALS) inhibitor of the herbicide sulfonylurea family, can induce rapeseed (Brassica napus L.) male sterility at approximately 1% concentration required for its herbicidal activity. To find some clues to the mechanism of MES inducing male sterility, the ultrastructural cytology observations, comparative transcriptome analysis, and physiological analysis on carbohydrate content were carried out in leaves and anthers at different developmental stages between the MES-treated and mock-treated rapeseed plants. Cytological analysis revealed that the plastid ultrastructure was abnormal in pollen mother cells and tapetal cells in male sterility anthers induced by MES treatment, with less material accumulation in it. However, starch granules were observed in chloroplastids of the epidermis cells in male sterility anthers. Comparative transcriptome analysis identified 1501 differentially expressed transcripts (DETs) in leaves and anthers at different developmental stages, most of these DETs being localized in plastid and mitochondrion. Transcripts involved in metabolism, especially in carbohydrate and lipid metabolism, and cellular transport were differentially expressed. Pathway visualization showed that the tightly regulated gene network for metabolism was reprogrammed to respond to MES treatment. The results of cytological observation and transcriptome analysis in the MES-treated rapeseed plants were mirrored by carbohydrate content analysis. MES treatment led to decrease in soluble sugars content in leaves and early stage buds, but increase in soluble sugars content and decrease in starch content in middle stage buds. Our integrative results suggested that carbohydrate and lipid metabolism were influenced by CHA-MES treatment during rapeseed anther development, which might

  14. Cataracts induced by microwave and ionizing radiation

    SciTech Connect

    Lipman, R.M.; Tripathi, B.J.; Tripathi, R.C.

    1988-11-01

    Microwaves most commonly cause anterior and/or posterior subcapsular lenticular opacities in experimental animals and, as shown in epidemiologic studies and case reports, in human subjects. The formation of cataracts seems to be related directly to the power of the microwave and the duration of exposure. The mechanism of cataractogenesis includes deformation of heat-labile enzymes, such as glutathione peroxide, that ordinarily protect lens cell proteins and membrane lipids from oxidative damage. Oxidation of protein sulfhydryl groups and the formation of high-molecular-weight aggregates cause local variations in the orderly structure of the lens cells. An alternative mechanism is thermoelastic expansion through which pressure waves in the aqueous humor cause direct physical damage to the lens cells. Cataracts induced by ionizing radiation (e.g., X-rays and gamma rays) usually are observed in the posterior region of the lens, often in the form of a posterior subcapsular cataract. Increasing the dose of ionizing radiation causes increasing opacification of the lens, which appears after a decreasing latency period. Like cataract formation by microwaves, cataractogenesis induced by ionizing radiation is associated with damage to the lens cell membrane. Another possible mechanism is damage to lens cell DNA, with decreases in the production of protective enzymes and in sulfur-sulfur bond formation, and with altered protein concentrations. Until further definitive conclusions about the mechanisms of microwaves and ionizing radiation induced cataracts are reached, and alternative protective measures are found, one can only recommend mechanical shielding from these radiations to minimize the possibility of development of radiation-induced cataracts. 74 references.

  15. Applied radiation physics: The use of x-rays for the structural characterization of aqueous emulsions and the development of new insect sterilization protocols

    NASA Astrophysics Data System (ADS)

    Brar, Ramaninder K.

    significant complications arise, such as an inability to compete with non-irradiated males and high mortality rates. To improve mosquito SIT, we have developed new radiation protocols for insect sterilization using long wavelength x-rays. Our results have demonstrated that longer wavelength x-rays have a significant effect on the outcome of the sterile males' longevity as well as on the efficacy of sterilization while employing a substantially lower dose.

  16. Sterile Neutrinos

    NASA Astrophysics Data System (ADS)

    Palazzo, Antonio

    2016-05-01

    Several anomalies recorded in short-baseline neutrino experiments suggest the possibility that the standard 3-flavor framework may be incomplete and point towards a manifestation of new physics. Light sterile neutrinos provide a credible solution to these puzzling results. Here, we present a concise review of the status of the neutrino oscillations within the 3+1 scheme, the minimal extension of the standard 3-flavor framework endowed with one sterile neutrino species. We emphasize the potential role of LBL experiments in the searches of CP violation related to sterile neutrinos and their complementarity with the SBL experiments.

  17. Radiation-induced brain injury: A review

    PubMed Central

    Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G.; Wheeler, Kenneth T.; Chan, Michael D.

    2012-01-01

    Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their

  18. Bile acids in radiation-induced diarrhea

    SciTech Connect

    Arlow, F.L.; Dekovich, A.A.; Priest, R.J.; Beher, W.T.

    1987-10-01

    Radiation-induced bowel disease manifested by debilitating diarrhea is an unfortunate consequence of therapeutic irradiation for pelvic malignancies. Although the mechanism for this diarrhea is not well understood, many believe it is the result of damage to small bowel mucosa and subsequent bile acid malabsorption. Excess amounts of bile acids, especially the dihydroxy components, are known to induce water and electrolyte secretion and increase bowel motility. We have directly measured individual and total bile acids in the stool samples of 11 patients with radiation-induced diarrhea and have found bile acids elevated two to six times normal in eight of them. Our patients with diarrhea and increased bile acids in their stools had prompt improvement when given cholestyramine. They had fewer stools and returned to a more normal life-style.

  19. Sterile-filtered saliva is a strong inducer of IL-6 and IL-8 in oral fibroblasts.

    PubMed

    Cvikl, Barbara; Lussi, Adrian; Moritz, Andreas; Sculean, Anton; Gruber, Reinhard

    2015-03-01

    Saliva has been implicated to support oral wound healing, a process that requires a transient inflammatory reaction. However, definitive proof that saliva can provoke an inflammatory response remained elusive. We investigated the ability of freshly harvested and sterile-filtered saliva to cause an inflammatory response of oral fibroblasts and epithelial cells. The expression of cytokines and chemokines was assessed by microarray, RT-PCR, immunoassays, and Luminex technology. The involvement of signaling pathways was determined by Western blot analysis and pharmacologic inhibitors. We report that sterile-filtered whole saliva was a potent inducer of IL-6 and IL-8 in fibroblasts from the gingiva, the palate, and the periodontal ligament, but not of oral epithelial cells. This strong inflammatory response requires nuclear factor-kappa B and mitogen-activated protein kinase signaling. The pro-inflammatory capacity is heat stable and has a molecular weight of <40 kDa. Genome-wide microarrays and Luminex technology further revealed that saliva substantially increased expression of other inflammatory genes and various chemokines. To preclude that the observed pro-inflammatory activity is the result of oral bacteria, sterile-filtered parotid saliva, collected under almost aseptic conditions, was used and also increased IL-6 and IL-8 expression in gingiva fibroblasts. The inflammatory response was, furthermore, independent of MYD88, an adapter protein of the Toll-like receptor signaling pathway. We conclude that saliva can provoke a robust inflammatory response in oral fibroblasts involving the classical nuclear factor-kappa B and mitogen-activated protein kinase signaling pathway. Since fibroblasts but not epithelial cells show a strong inflammatory response, saliva may support the innate immunity of defect sites exposing the oral connective tissue.

  20. Ionizing Radiation-induced Diseases in Korea

    PubMed Central

    Jeong, Meeseon; Moon, Kieun; Jo, Min-Heui; Kang, Seong-Kyu

    2010-01-01

    Radiation risk has become well known through epidemiological studies of clinically or occupationally exposed populations, animal experiments, and in vitro studies; however, the study of radiation related or induced disease has been limited in Korea. This study is to find the level of occupational radiation exposure for various kinds of accidents, compensated occupational diseases, related studies, and estimations on future occupational disease risks. Research data of related institutions were additionally investigated. About 67% of 62,553 radiation workers had no exposure or less than 1.2 mSv per year. The 5 reported cases on radiation accident patients in Korea occurred during nondestructive testing. According to the recent rapid increase in the number of workers exposed to radiation, a higher social recognition of cancer, and an increasing cancer mortality rate, it is expected that occupational disease compensation will rapidly increase as well. Therefore, it is important to develop scientific and objective decision methods, such as probability of causation and screening dose in the establishment of an exposure and health surveillance system. PMID:21258594

  1. Tubal Sterilization

    MedlinePlus

    ... pregnancy. Tubal sterilization is a permanent form of birth control. It is one of the most effective options for preventing pregnancy. But it is difficult to reverse. It doesn’t protect against sexually ...

  2. Postpartum Sterilization

    MedlinePlus

    ... a few hours or days following delivery. For women who have had a cesarean delivery, it is done right after the baby is born. How is postpartum sterilization performed? For women who have had a vaginal delivery, a small ...

  3. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    SciTech Connect

    Rauch, Philipp J.; Park, Henry S.; Knisely, Jonathan P.S.; Chiang, Veronica L.; Vortmeyer, Alexander O.

    2012-05-01

    Purpose: Recently, single-fraction, high-dosed focused radiation therapy such as that administered by Gamma Knife radiosurgery has been used increasingly for the treatment of metastatic brain cancer. Radiation therapy to the brain can cause delayed leukoencephalopathy, which carries its own significant morbidity and mortality. While radiosurgery-induced leukoencephalopathy is known to be clinically different from that following fractionated radiation, pathological differences are not well characterized. In this study, we aimed to integrate novel radiographic and histopathologic observations to gain a conceptual understanding of radiosurgery-induced leukoencephalopathy. Methods and Materials: We examined resected tissues of 10 patients treated at Yale New Haven Hospital between January 1, 2009, and June 30, 2010, for brain metastases that had been previously treated with Gamma Knife radiosurgery, who subsequently required surgical management of a symptomatic regrowing lesion. None of the patients showed pathological evidence of tumor recurrence. Clinical and magnetic resonance imaging data for each of the 10 patients were then studied retrospectively. Results: We provide evidence to show that radiosurgery-induced leukoencephalopathy may present as an advancing process that extends beyond the original high-dose radiation field. Neuropathologic examination of the resected tissue revealed traditionally known leukoencephalopathic changes including demyelination, coagulation necrosis, and vascular sclerosis. Unexpectedly, small and medium-sized vessels revealed transmural T-cell infiltration indicative of active vasculitis. Conclusions: We propose that the presence of a vasculitic component in association with radiation-induced leukoencephalopathy may facilitate the progressive nature of the condition. It may also explain the resemblance of delayed leukoencephalopathy with recurring tumor on virtually all imaging modalities used for posttreatment follow-up.

  4. Sterile neutrinos

    SciTech Connect

    Kopp, J.; Machado, P. A. N.

    2016-06-21

    We characterize statistically the indications of a presence of one or more light sterile neutrinos from MiniBooNE and LSND data, together with the reactor and gallium anomalies, in the global context. The compatibility of the aforementioned signals with null results from solar, atmospheric, reactor, and accelerator experiments is evaluated. We conclude that a severe tension is present in the global fit, and therefore the addition of eV-scale sterile neutrinos does not satisfactorily explain the anomalies.

  5. Sterile neutrinos

    NASA Astrophysics Data System (ADS)

    Kopp, J.; Machado, P. A. N.; Maltoni, M.; Schwetz, T.

    2016-06-01

    We characterize statistically the indications of a presence of one or more light sterile neutrinos from MiniBooNE and LSND data, together with the reactor and gallium anomalies, in the global context. The compatibility of the aforementioned signals with null results from solar, atmospheric, reactor, and accelerator experiments is evaluated. We conclude that a severe tension is present in the global fit, and therefore the addition of eV-scale sterile neutrinos does not satisfactorily explain the anomalies.

  6. [Evaluation of the influence of sterilization method on the stability of carboxymethyl cellulose wound dressing].

    PubMed

    Muselík, Jan; Wojnarová, Lenka; Masteiková, Ruta; Sopuch, Tomáš

    2013-04-01

    Carboxymethyl cellulose, especially its sodium salt, is a versatile pharmaceutical excipient. From a therapeutic point of view, sodium salt of carboxymethyl cellulose is used in the production of modern wound dressings to allow moist wound healing. Wound dressings must be sterile and stable throughout their shelf life and have to be able to withstand different temperature conditions. At the present time, a number of sterilization methods are available. In the case of polymeric materials, the selected sterilization process must not induce any changes in the polymer structure, such as polymer chains cleavage, changes in cross-linking, etc. This paper evaluates the influence of different sterilization methods (γ-radiation, β-radiation, ethylene oxide) on the stability of carboxymethyl cellulose and the results of long-term and accelerated stability testing. Evaluation of samples was performed using size-exclusion chromatography. The obtained results showed that ethylene oxide sterilization was the least aggressive variant of the sterilization methods tested. When the γ-radiation sterilization was used, the changes in the size of the carboxymethyl cellulose molecule occurred. In the course of accelerated and long term stability studies, no further degradation changes were observed, and thus sterilized samples are suitable for long term storage.

  7. The role of d-dimer as first marker of thrombophilia in women affected by sterility: implications in pathophysiology and diagnosis of thrombophilia induced sterility

    PubMed Central

    Di Micco, Pierpaolo; D'Uva, Maristella; Strina, Ida; Mollo, Antonio; Amato, Valeria; Niglio, Alferio; De Placido, Giuseppe

    2004-01-01

    Background D-dimer is considered a marker of hypercoagulable state and of endogenous fibrinolysis, so increased d-dimer is detectable in patients affected by thrombosis. Yet, several studies showed that also infertility, in particular secondary infertility due to recurrent fetal losses, has been often related to thrombotic events, in particular in women carrying thrombotic risk factors such as inherited thrombophilia (MTHFRC677T, PTHRA20210G, Factor V Leiden polimorphisms and/or inhAfter this screening we selected 39erited protein C, protein S, AT III deficiency) or acquired thrombophilia (primary antiphospholipid syndrome, acquired protein C, protein S, AT III deficiency, drugs induced thrombophilia). However, because its high predictive negative value in case of suspected thrombosis, increased d-dimer has been often associated to subclinical thrombophilia. The aim of this study is to investigate the role of d-dimer as first marker of thrombophilia in women affected by unexplained infertility and subsequently to search the cause of increased d-dimer, such as inherited and/or acquired thrombophilia. Patients and Methods We selected 79 patients with unexplained primary or secondary infertility. We excluded 40 patients affected by hydrosalpinx, uterine fibroids, uterine malformations, endocrinological and immunological diseases, luteal insufficiency, cytogenetical alterations. All remaining 39 patients were tested for d-dimer and divided in two groups: the patients of group A (25 patients) showed increased plasma d-dimer, in group B were included 14 patients with normal plasma level of d-dimer. After this step all 39 patients were screened for MTHFRC677T, PTHRA20210G, Factor V Leiden polimorphisms, protein C, protein S, AT III, anticardiolipin IgM and IgG, lupus anticoagulant. In the control group were included 15 age matched women without sterility problems referred to our outpatient's section of vascular medicine for suspected deep venous thrombosis. Statistical

  8. Radiation-induced mutation at minisatellite loci

    SciTech Connect

    Dubrova, Y.E. |; Nesterov, V.N.; Krouchinsky, N.G.

    1997-10-01

    We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of {gamma}-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure {sup 137}Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed.

  9. Mouse models for radiation-induced cancers.

    PubMed

    Rivina, Leena; Davoren, Michael J; Schiestl, Robert H

    2016-09-01

    Potential ionising radiation exposure scenarios are varied, but all bring risks beyond the simple issues of short-term survival. Whether accidentally exposed to a single, whole-body dose in an act of terrorism or purposefully exposed to fractionated doses as part of a therapeutic regimen, radiation exposure carries the consequence of elevated cancer risk. The long-term impact of both intentional and unintentional exposure could potentially be mitigated by treatments specifically developed to limit the mutations and precancerous replication that ensue in the wake of irradiation The development of such agents would undoubtedly require a substantial degree of in vitro testing, but in order to accurately recapitulate the complex process of radiation-induced carcinogenesis, well-understood animal models are necessary. Inbred strains of the laboratory mouse, Mus musculus, present the most logical choice due to the high number of molecular and physiological similarities they share with humans. Their small size, high rate of breeding and fully sequenced genome further increase its value for use in cancer research. This chapter will review relevant m. musculus inbred and F1 hybrid animals of radiation-induced myeloid leukemia, thymic lymphoma, breast and lung cancers. Method of cancer induction and associated molecular pathologies will also be described for each model. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Key role for neutrophils in radiation-induced antitumor immune responses: Potentiation with G-CSF

    PubMed Central

    Takeshima, Tsuguhide; Pop, Laurentiu M.; Laine, Aaron; Iyengar, Puneeth; Vitetta, Ellen S.; Hannan, Raquibul

    2016-01-01

    Radiation therapy (RT), a major modality for treating localized tumors, can induce tumor regression outside the radiation field through an abscopal effect that is thought to involve the immune system. Our studies were designed to understand the early immunological effects of RT in the tumor microenvironment using several syngeneic mouse tumor models. We observed that RT induced sterile inflammation with a rapid and transient infiltration of CD11b+Gr-1high+ neutrophils into the tumors. RT-recruited tumor-associated neutrophils (RT-Ns) exhibited an increased production of reactive oxygen species and induced apoptosis of tumor cells. Tumor infiltration of RT-Ns resulted in sterile inflammation and, eventually, the activation of tumor-specific cytotoxic T cells, their recruitment into the tumor site, and tumor regression. Finally, the concurrent administration of granulocyte colony-stimulating factor (G-CSF) enhanced RT-mediated antitumor activity by activating RT-Ns. Our results suggest that the combination of RT and G-CSF should be further evaluated in preclinical and clinical settings. PMID:27651484

  11. Study of chemical and radiation induced carcinogenesis

    SciTech Connect

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  12. Radiation-induced heart disease in rats

    SciTech Connect

    Lauk, S.; Kiszel, Z.; Buschmann, J.; Trott, K.R.

    1985-04-01

    After local irradiation of the rat heart with X ray doses of over 10 Gy (single dose), animals developed symptoms of radiation-induced heart disease, which at higher doses would lead to fatal cardiac failure. The LD 50 at 1 year was between 15 Gy and 20 Gy. The pericardium and epicardium responded to irradiation with exudative pericarditis after 4 months. Focal myocardial damage was secondary to progressive capillary damage.

  13. Heat pump processes induced by laser radiation

    NASA Technical Reports Server (NTRS)

    Garbuny, M.; Henningsen, T.

    1980-01-01

    A carbon dioxide laser system was constructed for the demonstration of heat pump processes induced by laser radiation. The system consisted of a frequency doubling stage, a gas reaction cell with its vacuum and high purity gas supply system, and provisions to measure the temperature changes by pressure, or alternatively, by density changes. The theoretical considerations for the choice of designs and components are dicussed.

  14. Radiation induced fracture of the scapula

    SciTech Connect

    Riggs, J.H. III; Schultz, G.D.; Hanes, S.A. )

    1990-10-01

    A case of radiation induced osteonecrosis resulting in a fracture of the scapula in a 76-yr-old female patient with a history of breast carcinoma is presented. Diagnostic imaging, laboratory recommendations and clinical findings are discussed along with an algorithm for the safe management of patients with a history of cancer and musculoskeletal complaints. This case demonstrates the necessity of a thorough investigation of musculoskeletal complaints in patients with previous bone-seeking carcinomas.

  15. A genetic resource for early-morning flowering trait of wild rice Oryza officinalis to mitigate high temperature-induced spikelet sterility at anthesis

    PubMed Central

    Ishimaru, Tsutomu; Hirabayashi, Hideyuki; Ida, Masashi; Takai, Toshiyuki; San-Oh, Yumiko A.; Yoshinaga, Satoshi; Ando, Ikuo; Ogawa, Tsugufumi; Kondo, Motohiko

    2010-01-01

    Background and Aims High temperatures over 32–36 °C at anthesis induce spikelet sterility in rice. The use of a germplasm with an early-morning flowering (EMF) trait has been hypothesized as a way of avoiding this problem. In this study, the effect of the EMF trait on avoiding high temperature-induced sterility at anthesis by flowering at a cooler temperature in the early morning was evaluated. Methods The EMF trait was introgressed from wild rice (Oryza officinalis) into the rice cultivar ‘Koshihikari’ (O. sativa). First, spikelets of the EMF line and Koshihikari were subjected to rising temperatures during the daytime in the greenhouse to test for differences in spikelet sterility. Secondly, spikelets of both plants were exposed to 26, 34 and 38 °C at anthesis and to 38 °C beginning at least 1 h after flowering, in the growth chambers at 70 % relative humidity, to test for differences in tolerance to high temperatures. Key Results Spikelets of the EMF line started and completed flowering a few hours earlier than Koshihikari. In a greenhouse experiment, spikelets of Koshihikari opened after the air temperature reached 35 °C, but those of the EMF line could open at cooler temperatures. Under these conditions, spikelet sterility significantly increased in Koshihikari, but did not in the EMF line. The number of sterile spikelets increased as their flowering time was delayed in Koshihikari. Furthermore, the chamber experiments revealed that 60 % of the spikelets from both lines were sterile when exposed to 38 °C at anthesis, indicating that tolerance of high temperature was similar in both genotypes. Conclusions Reduced sterility in the EMF line subjected to rising temperatures at anthesis in the greenhouse was attributed to an earlier flowering time compared with Koshihikari. The EMF trait of wild rice is effective in mitigating anticipated yield loss due to global warming by escaping high-temperature stress at anthesis during the daytime. PMID:20566680

  16. Role of neurotensin in radiation-induced hypothermia in rats

    SciTech Connect

    Kandasamy, S.B.; Hunt, W.A.; Harris, A.H. )

    1991-05-01

    The role of neurotensin in radiation-induced hypothermia was examined. Intracerebroventricular (ICV) administration of neurotensin produced dose-dependent hypothermia. Histamine appears to mediate neurotensin-induced hypothermia because the mast cell stabilizer disodium cromoglycate and antihistamines blocked the hypothermic effects of neurotensin. An ICV pretreatment with neurotensin antibody attenuated neurotensin-induced hypothermia, but did not attenuate radiation-induced hypothermia, suggesting that radiation-induced hypothermia was not mediated by neurotensin.

  17. Hysteroscopic sterilization.

    PubMed

    Cooper, J M

    1992-06-01

    After a brief history of sterilization, this article is devoted to hysteroscopic techniques and instrumentation, and a presentation of hysteroscopic sterilization techniques: electrocoagulation techniques, hysteroscopic injection of chemicals, and hysteroscopically directed placement of intratubal mechanical devices (ceramic plugs, polyethylene plugs, preformed silicone plugs, nylon intratubal plugs, and formed-in-place silicone rubber plugs. Problems are identified that are common to all hysteroscopic sterilization techniques. There are also practical considerations which limit the development of hysteroscopic sterilization techniques, and these considerations are presented. Various means have been used historically to block the tubal ostia, including the insertion of nitric acid in 1984, but it was not until 1927 that the hysteroscope was used for sterilization. Hysteroscopy itself was discovered in 1869 for diagnosis of intrauterine diseases. Even with the hysteroscope and the 1934 procedure of using an electric current in the tubal ostia, hysteroscopic sterilization was little used. In 1973 a convention was convened to discuss the use of the procedure and the ramifications. Currently, the hysteroscope is a modified cytoscope with a 4 mm wide telescope with a fore-oblique lens, a 7 mm wide metallic sheath, a fiberoptic bundle for transmission of light, and additional instruments for intrauterine manipulation or surgical intervention. Under local anesthesia, sterilization is effected by 1) destruction of the interstitial portion of the oviduct by thermal energy, 2) injection techniques for the delivery of sclerosing substances or tissue adhesives, or 3) mechanical occlusive devices or plugs to block the oviduct. Recent uterine, cervical, or adnexal infections and pregnancy prevent the performance of sterilization, because infections are exacerbated by the procedure. Uterine perforation is a complication. Other complications involve allergic reactions to the

  18. Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus.

    PubMed

    Walther, L E; Asenov, D R; Di Martino, E

    2011-04-01

    Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

  19. Radiation induced dynamic mutations and transgenerational effects.

    PubMed

    Niwa, Ohtsura

    2006-01-01

    Many studies have confirmed that radiation can induce genomic instability in whole body systems. Although the molecular mechanisms underlying induced genomic instability are not known at present, this interesting phenomenon could be the manifestation of a cellular fail-safe system in which fidelity of repair and replication is down-regulated to tolerate DNA damage. Two features of genomic instability namely, delayed mutation and untargeted mutation, require two mechanisms of ;damage memory' and ;damage sensing, signal transduction and execution' to induce mutations at a non damaged-site. In this report, the phenomenon of transgenerational genomic instability and possible mechanisms are discussed using mouse data collected in our laboratory as the main bases.

  20. Radiation induced genomic instability in bystander cells

    NASA Astrophysics Data System (ADS)

    Zhou, H.; Gu, S.; Randers-Pehrson, G.; Hei, T.

    There is considerable evidence that exposure to ionizing radiation may induce a heritable genomic instability that leads to a persisting increased frequency of genetic and functional changes in the non-irradiated progeny of a wide variety of irradiated cells Genomic instability is measured as delayed expressions in chromosomal alterations micronucleus formation gene mutations and decreased plating efficiency During the last decade numerous studies have shown that radiation could induce bystander effect in non-irradiated neighboring cells similar endpoints have also been used in genomic instability studies Both genomic instability and the bystander effect are phenomena that result in a paradigm shift in our understanding of radiation biology In the past it seemed reasonable to assume that the production of single- and double-strand DNA breaks are due to direct energy deposition of energy by a charged particle to the nucleus It turns out that biology is not quite that simple Using the Columbia University charged particle microbeam and the highly sensitive human hamster hybrid AL cell mutagenic assay we irradiated 10 of the cells with a lethal dose of 30 alpha particles through the nucleus After overnight incubation the remaining viable bystander cells were replated in dishes for colony formation Clonal isolates were expanded and cultured for 6 consecutive weeks to assess plating efficiency and mutation frequency Preliminary results indicated that there was no significant decrease in plating efficiency among the bystander colonies when compared with

  1. Radiation biology of mosquitoes

    PubMed Central

    Helinski, Michelle EH; Parker, Andrew G; Knols, Bart GJ

    2009-01-01

    There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators. PMID:19917076

  2. Radiation induced carcinoma of the larynx

    SciTech Connect

    Amendola, B.E.; Amendola, M.A.; McClatchey, K.D.

    1985-07-01

    A squamous cell carcinoma presented in a 20 year old female nonsmoker three years after receiving a high dosage of radiation therapy to the base of the skull, face and entire neuroaxis and intense combination chemotherapy for a parameningeal rhabdomyosarcoma of the paranasal sinuses is reported. The larynx received a dose of about 3,500 rads over an eight week period. This dosage in conjunction with the associated intense chemotherapy regimen given to the patient may explain the appearance of a radiation induced tumor in an unusually short latent period. This certainly represents a risk in young patients in whom an aggressive combined approach is taken and the physician should be aware of.

  3. Management of radiation-induced rectal bleeding.

    PubMed

    Laterza, Liboria; Cecinato, Paolo; Guido, Alessandra; Mussetto, Alessandro; Fuccio, Lorenzo

    2013-11-01

    Pelvic radiation disease is one of the major complication after radiotherapy for pelvic cancers. The most commonly reported symptom is rectal bleeding which affects patients' quality of life. Therapeutic strategies for rectal bleeding are generally ignored and include medical, endoscopic, and hyperbaric oxygen treatments. Most cases of radiation-induced bleeding are mild and self-limiting, and treatment is normally not indicated. In cases of clinically significant bleeding (i.e. anaemia), medical therapies, including stool softeners, sucralfate enemas, and metronidazole, should be considered as first-line treatment options. In cases of failure, endoscopic therapy, mainly represented by argon plasma coagulation and hyperbaric oxygen treatments, are valid and complementary second-line treatment strategies. Although current treatment options are not always supported by high-quality studies, patients should be reassured that treatment options exist and success is achieved in most cases if the patient is referred to a dedicated centre.

  4. Estimation of radiation-induced cancer from three-dimensional dose distributions: Concept of organ equivalent dose

    SciTech Connect

    Schneider, Uwe . E-mail: uwe.schneider@psi.ch; Zwahlen, Daniel; Ross, Dieter; Kaser-Hotz, Barbara

    2005-04-01

    Purpose: Estimates of secondary cancer risk after radiotherapy are becoming more important for comparative treatment planning. Modern treatment planning systems provide accurate three-dimensional dose distributions for each individual patient. These data open up new possibilities for more precise estimates of secondary cancer incidence rates in the irradiated organs. We report a new method to estimate organ-specific radiation-induced cancer incidence rates. The concept of an organ equivalent dose (OED) for radiation-induced cancer assumes that any two dose distributions in an organ are equivalent if they cause the same radiation-induced cancer incidence. Methods and Materials: The two operational parameters of the OED concept are the organ-specific cancer incidence rate at low doses, which is taken from the data of the atomic bomb survivors, and cell sterilization at higher doses. The effect of cell sterilization in various organs was estimated by analyzing the secondary cancer incidence data of patients with Hodgkin's disease who were treated with radiotherapy in between 1962 and 1993. The radiotherapy plans used at the time the patients had been treated were reconstructed on a fully segmented whole body CT scan. The dose distributions were calculated in individual organs for which cancer incidence data were available. The model parameter that described cell sterilization was obtained by analyzing the dose and cancer incidence rates for the individual organs. Results: We found organ-specific cell radiosensitivities that varied from 0.017 for the mouth and pharynx up to 1.592 for the bladder. Using the two model parameters (organ-specific cancer incidence rate and the parameter characterizing cell sterilization), the OED concept can be applied to any three-dimensional dose distribution to analyze cancer incidence. Conclusion: We believe that the concept of OED presented in this investigation represents a first step in assessing the potential risk of secondary

  5. Sterile connector.

    PubMed

    Tenczar, F J

    1976-01-01

    Fabrication of a sterile connector for joining a supply source to an independent delivery location through a contaminated environment requires four design steps: 1) alignment of connector housings; 2) exclusion of the contaminated environment; 3) sterilization of the excluded region; and 4) penetration within the sterilized area followed by coupling of the protected internal conduits. Protective covers for connectors now in use may be modified to provide penetrable terminal barrier membranes that can be joined to exclude the environment. An adhesive containing an antimicrobiologic agent would set the stage for a controlled mechanical penetration of the decontaminated fused barriers. In another design concept, plastic barrier membranes without preliminary adhesions are simultaneously fused, sterilized, and penetrated by a nichrome wire heated to approximately 288 C. A system can be designed that is compatible, at the option of the user, with either of these methods. The more economical mechanical approach could then be used for parenteral fluid therapy while the nichrome wire technique would be reserved for more complex processing methods (frozen erythrocytes) or when storage of the resulting component is a factor.

  6. The sterile inflammatory response.

    PubMed

    Rock, Kenneth L; Latz, Eicke; Ontiveros, Fernando; Kono, Hajime

    2010-01-01

    The acute inflammatory response is a double-edged sword. On the one hand, it plays a key role in initial host defense, particularly against many infections. On the other hand, its aim is imprecise, and as a consequence, when it is drawn into battle, it can cause collateral damage in tissues. In situations where the inciting stimulus is sterile, the cost-benefit ratio may be high; because of this, sterile inflammation underlies the pathogenesis of a number of diseases. Although there have been major advances in our understanding of how microbes trigger inflammation, much less has been learned about this process in sterile situations. This review focuses on a subset of the many sterile stimuli that can induce inflammation-specifically dead cells and a variety of irritant particles, including crystals, minerals, and protein aggregates. Although this subset of stimuli is structurally very diverse and might appear to be unrelated, there is accumulating evidence that the innate immune system may recognize them in similar ways and stimulate the sterile inflammatory response via common pathways. Here we review established and emerging data about these responses.

  7. Radiation-induced osteosarcoma of the sphenoid bone

    SciTech Connect

    Tanaka, S.; Nishio, S.; Morioka, T.; Fukui, M.; Kitamura, K.; Hikita, K. )

    1989-10-01

    The case of a patient who developed osteosarcoma in the sphenoid bone 15 years after radiation therapy for a craniopharyngioma is reported. Radiation-induced osteosarcoma of the sphenoid bone has not been reported previously. Reported cases of radiation-induced osteosarcomas are reviewed.

  8. Radiation-induced injury of the esophagus

    SciTech Connect

    Lepke, R.A.; Libshitz, H.I.

    1983-08-01

    Forty patients with functional or morphologic esophageal abnormalities following radiotherapy were identified. Abnormalities included abnormal motility with and without mucosal edema, stricture, ulceration and pseudodiverticulum, and fistula. Abnormal motility occurred 4 to 12 weeks following radiotherapy alone and as early as 1 week after therapy when concomitant chemotherapy had been given. Strictures developed 4 to 8 months following completion of radiotherapy. Ulceration, pseudodiverticulum, and fistula formation did not develop in a uniform time frame. Radiation-induced esophageal injury is more frequent when radiotherapy and chemotherapy are combined than it is with radiotherapy alone.

  9. Radiation-induced esophagitis in lung cancer

    PubMed Central

    Baker, Sarah; Fairchild, Alysa

    2016-01-01

    Radiation-induced esophagitis is the most common local acute toxicity of radiotherapy (RT) delivered for the curative or palliative intent treatment of lung cancer. Although concurrent chemotherapy and higher RT dose are associated with increased esophagitis risk, advancements in RT techniques as well as adherence to esophageal dosimetric constraints may reduce the incidence and severity. Mild acute esophagitis symptoms are generally self-limited, and supportive management options include analgesics, acid suppression, diet modification, treatment for candidiasis, and maintenance of adequate nutrition. Esophageal stricture is the most common late sequela from esophageal irradiation and can be addressed with endoscopic dilatation. Approaches to prevent or mitigate these toxicities are also discussed. PMID:28210168

  10. Radiation-induced segregation, hardening, and IASCC

    SciTech Connect

    Eason, E.D.; Nelson, E.E.

    1995-12-31

    Intergranular cracking has been discovered after extended radiation exposure in several boiling water reactor (BWR) internal components made of austenitic stainless steel and nickel-based alloys. There are fewer field observations of intergranular cracking in pressurized water reactors (PWR), but failures have occurred in bolts, springs, and fuel cladding. There is concern for other PWR components, some of which will receive greater radiation doses than BWR components during the plant lifetime. This paper presents the results of an investigation on the connection between radiation induced segregation, hardening and irradiation-assisted stress corrosion cracking (IASCC). A data base was developed containing the available data on austenitic stainless steel where the grain boundary composition was measured by Field Emission Gun-Scanning Transmission Election Microscopy (FEG-STEM), the stress corrosion susceptibility was measured by constant extension rate tests (CERT) in light water reactor environments, some estimate of irradiated strength was available and the irradiation was conducted in a power reactor. The data base was analyzed using advanced data analysis techniques, including tree-structured pattern recognition and transformation analysis codes. The most sensitive variables and optimal modeling forms were identified using these techniques, then preliminary models were calibrated using nonlinear least squares. The results suggest that more than one mechanism causes IASCC.

  11. Radiation-induced uterine changes: MR imaging

    SciTech Connect

    Arrive, L.; Chang, Y.C.; Hricak, H.; Brescia, R.J.; Auffermann, W.; Quivey, J.M.

    1989-01-01

    To assess the capability of magnetic resonance (MR) imaging to demonstrate postirradiation changes in the uterus, MR studies of 23 patients who had undergone radiation therapy were retrospectively examined and compared with those of 30 patients who had not undergone radiation therapy. MR findings were correlated with posthysterectomy histologic findings. In premenopausal women, radiation therapy induced (a) a decrease in uterine size demonstrable as early as 3 months after therapy ended; (b) a decrease in signal intensity of the myometrium on T2-predominant MR images, reflecting a significant decrease in T2 relaxation time, demonstrable as early as 1 month after therapy; (c) a decrease in thickness and signal intensity of the endometrium demonstrable on T2-predominant images 6 months after therapy; and (d) loss of uterine zonal anatomy as early as 3 months after therapy. In postmenopausal women, irradiation did not significantly alter the MR imaging appearance of the uterus. These postirradiation MR changes in both the premenopausal and postmenopausal uteri appeared similar to the changes ordinarily seen on MR images of the nonirradiated postmenopausal uterus.

  12. Designing a program to assess potential induced radioactivity in electron beam sterilization of medical devices

    NASA Astrophysics Data System (ADS)

    Smith, Mark; Logar, John; Vrain, Olivier

    2014-12-01

    ISO 11137-1:2006 requires that the potential for induced radioactivity be evaluated for medical devices irradiated with electrons with energy more than 10 MeV. For a manufacturing operation where new devices are being developed, a practical program for making such an evaluation needs to be engrained in the process. A program was developed such that the induced radioactivity evaluation is imbedded in the development of the irradiation process.

  13. Mouse models of radiation-induced cancers.

    PubMed

    Rivina, Leena; Schiestl, Robert

    2013-01-01

    Radiation-induced (RI) secondary cancers were not a major clinical concern even as little as 15 years ago. However, advances in cancer diagnostics, therapy, and supportive care have saved numerous lives and many former cancer patients are now living for 5, 10, 20, and more years beyond their initial diagnosis. The majority of these patients have received radiotherapy as a part of their treatment regimen and are now beginning to develop secondary cancers arising from normal tissue exposure to damaging effects of ionizing radiation. Because historically patients rarely survived past the extended latency periods inherent to these RI cancers, very little effort was channeled towards the research leading to the development of therapeutic agents intended to prevent or ameliorate oncogenic effects of normal tissue exposure to radiation. The number of RI cancers is expected to increase very rapidly in the near future, but the field of cancer biology might not be prepared to address important issues related to this phenomena. One such issue is the ability to accurately differentiate between primary tumors and de novo arising secondary tumors in the same patient. Another issue is the lack of therapeutic agents intended to reduce such cancers in the future. To address these issues, large-scale epidemiological studies must be supplemented with appropriate animal modeling studies. This work reviews relevant mouse (Mus musculus) models of inbred and F1 animals and methodologies of induction of most relevant radiation-associated cancers: leukemia, lymphoma, and lung and breast cancers. Where available, underlying molecular pathologies are included. © 2013 Elsevier Inc. All rights reserved.

  14. Radar detection of radiation-induced ionization in air

    DOEpatents

    Gopalsami, Nachappa; Heifetz, Alexander; Chien, Hual-Te; Liao, Shaolin; Koehl, Eugene R.; Raptis, Apostolos C.

    2015-07-21

    A millimeter wave measurement system has been developed for remote detection of airborne nuclear radiation, based on electromagnetic scattering from radiation-induced ionization in air. Specifically, methods of monitoring radiation-induced ionization of air have been investigated, and the ionized air has been identified as a source of millimeter wave radar reflection, which can be utilized to determine the size and strength of a radiation source.

  15. Trifluoroethanol-induced conformational transition of the C-terminal sterile alpha motif (SAM) of human p73.

    PubMed

    Neira, José L; Cámara-Artigas, Ana

    2017-04-01

    The alpha splice variant of p73 (p73α), a homologue of the tumour suppressor p53, has at its C terminus a sterile alpha motif (SAM); this domain, SAMp73, is involved in lipid binding and it is thought to mediate in protein-protein interactions. As SAMp73 is a 68-residue-long helical bundle, it could be a good model to study the (2,2,2-trifluoroethanol) TFE-induced conformational transitions of α-helical proteins. Furthermore, as SAMp73 binds to lipids through a well-known polypeptide patch, we can test whether TFE is a good mimic of lipids and membranes. To address those questions, we used several biophysical probes, namely, fluorescence, circular dichroism, 1D, 2D and 3D-NMR spectroscopies, and dynamic light scattering. The TFE-induced conformational transition of SAMp73 was complex, involving several species as detected by the biophysical probes. The last TFE-induced transition occurred at a concentration of TFE of ∼20% (v/v), where the protein lost its compactness. None of those TFE-induced species accumulated during the two-state folding of SAMp73 in aqueous solution. The final state at 40% TFE was highly helical, but its structure was not rigid. For SAMp73, TFE did not properly mimic a membrane-like environment, since at very low TFE concentrations, other residues, together with those known to interact with lipids, were also affected by the co-solvent. Comparison with studies on isolated peptides, comprising the helical regions of SAMp73, suggests that peptides were good models of the intact protein in TFE.

  16. Radiation induced micrencephaly in guinea pigs

    SciTech Connect

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1991-01-01

    A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between radiation and small head size in humans at low doses as reported by Miller and Mulvihill. 16 refs., 13 tabs.

  17. Temporary sterility induced by intrascrotal deposition of silastic-polyvinylpyrrolidone-prostaglandin F2alpha tubes in the rabbit: effect on fetal survival after regain of fertility.

    PubMed

    Saksena, S K; Lau, I F

    1979-09-01

    In male rabbits of proven fertility, the intrascrotal deposition of two Silastic-polyvinylpyrrolidone tubes containing 3 mg of prostaglandin F2alpha (PGF2alpha)/tube induced within 2 to 4 weeks temporary sterility which lasted for 10 to 14 weeks. Associated with induced sterility were reduction in testicular weight, increase in abnormal spermatozoa (8% to 78% versus 0 to 3.7%), and reduction in sperm motility along the reproductive tract and in the semen for a period of 6 to 7 weeks. During the period of temporary sterility the weight of the epididymis, the sexual drive, and semen volume remained unaltered. Normal fertility was associated with an increase in testicular weight, reduction in the proportion of abnormal sperm, and improved sperm motility. In addition to an altered spermatogenesis, the integrity of mature spermatozoa seemed to be severely affected after PGF2alpha treatment. The reduced number of viable young sired by males that recovered from temporary sterility (pregnancy wastage 35%) as compared with sham-treated controls (pregnancy wastage 3%) suggests that a small percentage of spermatozoa might still be defective at the time of testing. A longer waiting period might be needed to ensure a completely normal reproductive process.

  18. Developing transgenic Anopheles mosquitoes for the sterile insect technique.

    PubMed

    Nolan, Tony; Papathanos, Philippos; Windbichler, Nikolai; Magnusson, Kalle; Benton, Jason; Catteruccia, Flaminia; Crisanti, Andrea

    2011-01-01

    In the last 10 years the availability of the genome sequence of Anopheles gambiae and the development of a transgenic technology for several species of Anopheles mosquitoes have, in combination, helped in enabling us to gain several insights into the biology of these mosquitoes that is relevant to their capacity as vectors of the malaria parasite. While this information is anticipated to inform many novel vector control strategies, the technique most likely to benefit in the near future from the availability of a reliable transgenic technology is the sterile insect technique (SIT), which relies on releasing large numbers of sterile insects to compete for mates in the wild, leading to population suppression. Although SIT has been proven to work reliably for many insects, the construction of suitable strains, and induction of sterility, has until now been a laborious process, combining classical genetics with radiation-induced sterility. Using transgenesis to create strains of Anopheles suitable for SIT could potentially offer several advantages over current approaches, in that the basic design of transgenic constructs designed for other insects should be rapidly transferable to mosquitoes, and induction of sterility as a product of the transgenic modification could obviate the requirement for radiation and its associated deleterious effects. In this paper the progress of different transgenic approaches in constructing tools for SIT will be reviewed.

  19. Structural mechanical properties of radiation-sterilized human Bone-Tendon-Bone grafts preserved by different methods.

    PubMed

    Gut, Grzegorz; Marowska, Joanna; Jastrzebska, Anna; Olender, Ewa; Kamiński, Artur

    2016-06-01

    To avoid the risk of infectious disease transmission from donor to recipient, allografts should be terminally sterilized. In the previous paper (Kaminski et al. in Cell Tissue Bank 10:215-219, 2009) we presented the effect of various methods of preservation (deep fresh freezing, glycerolization, lyophilization), followed by irradiation with different doses of electron beam (EB), on material (intrinsic) mechanical properties of human patellar tendons cut out as for anterior cruciate ligament reconstruction, obtained in failure tensile test. As structural mechanical properties are equally important to predict the behaviour of the graft as a whole functional unit, the purpose of the present paper was to show the results for failure load and elongation, obtained in the same experiment. Paired Bone-Tendon-Bone grafts (BTB) were prepared from cadaveric human patella tendons with both patellar and tibial attachments. They were preserved by deep freezing, glycerolization or lyophilization and subsequently EB-irradiated with the doses of 25, 35, 50 or 100 kGy (fresh-frozen grafts) or a single dose of 35 kGy (glycerolized and lyophilized grafts). Each experimental (irradiated) group was provided with control (non-irradiated), donor-matched group. The specimens from all groups were subjected to mechanical failure tensile test with the use of Instron system in order to measure their structural properties (failure load and elongation). All lyophilized grafts were rehydrated before mechanical testing. In our study we did not observe significant deterioration of structural mechanical properties of BTB grafts processed by fresh-freezing and then terminal sterilized with growing doses of EB up to 100 kGy. In contrast, BTB grafts processed by glycerolization or lyophilization and irradiated with 35 kGy showed significant decrease of failure load. Obtained results suggest that deep-frozen irradiated grafts retain their initial mechanical properties to an extent which does not

  20. A STUDY ON MICROWAVE INSTABILITY INDUCED RADIATION.

    SciTech Connect

    MURPHY,J.B.; WANG,J.M.

    1999-03-29

    It has been shown in the context of a solvable model that the microwave instability can be described in terms of ''coherent states'' [1]. Building on this model, we first show that the simplicity of the model arises from the fact that the key integral-differential equation can be reduced to the Karhunen-Loeve equation of the theory of stochastic processes. We present results on the correlation functions of the electric field. In particular, for the second order correlation function, we show that a relation akin to the Hanbury Brown-Twiss correlation holds for the coherent states of the microwave-instability induced radiation. We define an entropy-like quantity and we introduce a Wigner distribution function representation.

  1. Transesophageal Echocardiography and Radiation-induced Damages

    PubMed Central

    Cottini, Marzia; Polizzi, Vincenzo; Pino, Paolo Giuseppe; Buffa, Vitaliano; Musumeci, Francesco

    2016-01-01

    The long-term sequelae of mantle therapy include, especially lung and cardiac disease but also involve the vessels and the organs in the neck and thorax (such as thyroid, aorta, and esophagus). We presented the case of 66-year-old female admitted for congestive heart failure in radiation-induced heart disease. The patient had undergone to massive radiotherapy 42 years ago for Hodgkin's disease (type 1A). Transesophageal echocardiography was performed unsuccessfully with difficulty because of the rigidity and impedance of esophageal walls. Our case is an extraordinary report of radiotherapy's latency effect as a result of dramatic changes in the structure of mediastinum, in particular in the esophagus, causing unavailability of a transesophageal echocardiogram. PMID:27867461

  2. [Medical prevention and treatment of radiation-induced pulmonary complications].

    PubMed

    Vallard, A; Rancoule, C; Le Floch, H; Guy, J-B; Espenel, S; Le Péchoux, C; Deutsch, É; Magné, N; Chargari, C

    2017-08-01

    Radiation-induced lung injuries mainly include the (acute or sub-acute) radiation pneumonitis, the lung fibrosis and the bronchiolitis obliterans organizing pneumonia (BOOP). The present review aims at describing the diagnostic process, the current physiopathological knowledge, and the available (non dosimetric) preventive and curative treatments. Radiation-induced lung injury is a diagnosis of exclusion, since clinical, radiological, or biological pathognomonic evidences do not exist. Investigations should necessarily include a thoracic high resolution CT-scan and lung function tests with a diffusing capacity of the lung for carbon monoxide. No treatment ever really showed efficacy to prevent acute radiation-induced lung injury, or to treat radiation-induced lung fibrosis. The most promising drugs in order to prevent radiation-induced lung injury are amifostine, angiotensin-converting-enzyme inhibitors and pentoxifylline. Inhibitors of collagen synthesis are currently tested at a pre-clinical stage to limit the radiation-induced lung fibrosis. Regarding available treatments of radiation-induced pneumonitis, corticoids can be considered the cornerstone. However, no standardized program or guidelines concerning the initial dose and the gradual tapering have been scientifically established. Alternative treatments can be prescribed, based on clinical cases reporting on the efficacy of immunosuppressive drugs. Such data highlight the major role of the lung dosimetric protection in order to efficiently prevent radiation-induced lung injury. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  3. Sterilization of products contaminated with Pyronema domesticum.

    PubMed

    Lampe, Carol M; Hansen, Joyce M; Rymer, Therese M; Sargent, Harold

    2009-01-01

    Product recalls due to non-sterility occurred between 1993 and 1994 among manufacturers that were sterilizing cotton products sourced from China using ethylene oxide (EO). The primary contaminant was identified as a pyrophilous mold from the class Discomycetes, Pyronema domesticum. Multiple references suggest this organism has special needs for reproducing and maintaining the two assumed resistant stages of this organism (ascospores and sclerotia). Sterilization resistance studies were performed using a China-sourced cotton product that was naturally contaminated with P. domesticum. These studies showed the organisms to have: 1) a low resistance to moist heat sterilization at 250 degrees F (121 degrees C); a resistance to radiation no greater than that predicted by the bioburden-based resistance model (i.e., Population C) used for dose determination Method 1 described in ANSI/AAMI/ISO 11137-2:2006--Sterilization of health care products--Radiation--Part 2: Establishing the sterilization dose; and 3) a high resistance to EO processing.

  4. An efferocytosis-induced, IL-4–dependent macrophage-iNKT cell circuit suppresses sterile inflammation and is defective in murine CGD

    PubMed Central

    Zeng, Melody Yue; Pham, Duy; Bagaitkar, Juhi; Liu, Jianyun; Otero, Karel; Shan, Ming; Wynn, Thomas A.; Brombacher, Frank; Brutkiewicz, Randy R.; Kaplan, Mark H.

    2013-01-01

    Efferocytosis of apoptotic neutrophils by macrophages following tissue injury is fundamental to the resolution of inflammation and initiation of tissue repair. Using a sterile peritonitis model in mice, we identified interleukin (IL)-4–producing efferocytosing macrophages in the peritoneum that activate invariant natural killer T (iNKT) cells to produce cytokines including IL-4, IL-13, and interferon-γ. Importantly, IL-4 from macrophages contributes to alternative activation of peritoneal exudate macrophages and augments type 2 cytokine production from NKT cells to suppress inflammation. The increased peritonitis in mice deficient in IL-4, NKT cells, or IL-4Rα expression on myeloid cells suggested that each is a key component for resolution of sterile inflammation. The reduced NAD phosphate oxidase is also critical for this model, because in mice with X-linked chronic granulomatous disease (X-CGD) that lack oxidase subunits, activation of iNKT cells by X-CGD peritoneal exudate macrophages was impaired during sterile peritonitis, resulting in enhanced and prolonged inflammation in these mice. Therefore, efferocytosis-induced IL-4 production and activation of IL-4–producing iNKT cells by macrophages are immunomodulatory events in an innate immune circuit required to resolve sterile inflammation and promote tissue repair. PMID:23426944

  5. Obstructive jaundice due to radiation-induced hepatic duct stricture

    SciTech Connect

    Chandrasekhara, K.L.; Iyer, S.K.

    1984-10-01

    A case of obstructive jaundice due to radiation-induced hepatic duct stricture is reported. The patient received postoperative radiation for left adrenal carcinoma, seven years prior to this admission. The sequelae of hepatobiliary radiation and their management are discussed briefly.

  6. Radiation health: mechanisms of radiation-induced cataracts in astronauts.

    PubMed

    Frey, Mary Anne

    2009-06-01

    Dr. Blakely and colleagues have conducted a series of experiments to explain the molecular basis by which space radiation causes cataracts, particularly with regard to elucidating how space radiation alters gene expression profiles in the process of lens cell differentiation. To do this, they "developed an in vitro model of differentiating human lens epithelial cells...that mimicked the normal growth environment in the tissue" (2). They have shown that radiation, especially high-LET (linear energy transfer) iron ion radiation, affects gene and protein expression of many cells involved in lens cell differentiation and cell cycle regulation. They have also developed a schematic model to explain the action of ionizing radiation on specific molecules leading to perturbations in cell cycle regulation and ultimately affecting lens cell differentiation. These results can provide a basis for developing countermeasures to protect astronauts in long-duration spaceflight and for improving risk assessments of space-radiation-caused cataracts. This research can also benefit individuals on Earth who are exposed to clinical and occupational radiation.

  7. Rennet-induced aggregation and curd formation from skimmed milk powders prepared under different sterilizing conditions.

    PubMed

    Miyamoto, Yuka; Matsumiya, Kentaro; Kubouchi, Hiroaki; Noda, Masayuki; Nishimura, Kimio; Matsumura, Yasuki

    2009-09-01

    Heat treatment during the production of skimmed milk powder causes denaturation of proteins, thereby affecting the physicochemical properties of the skimmed milk powder. To understand the effects of heat treatment on the sensitivity of the casein micelles in skimmed milk powders, low heating type (L), normal heating type (N), high heating type (H), and super-high heating type (SH), to reaction with rennet, rennet-induced curd formation was investigated. A well-developed network structure with wide spaces was observed only in the curd derived from the solution of type L skimmed milk powder. SDS-PAGE suggested that there was no difference in the amount of glycomacropeptide generated from kappa-casein in the four types of skimmed milk powder, but casein micelles in the solution of type L skimmed milk powder formed aggregates most effectively. These results are discussed with respect to the thermal denaturation of proteins in skimmed milk powder.

  8. Inducible Sterilization of Zebrafish by Disruption of Primordial Germ Cell Migration

    PubMed Central

    Wong, Ten-Tsao; Collodi, Paul

    2013-01-01

    During zebrafish development, a gradient of stromal-derived factor 1a (Sdf1a) provides the directional cue that guides the migration of the primordial germ cells (PGCs) to the gonadal tissue. Here we describe a method to produce large numbers of infertile fish by inducing ubiquitous expression of Sdf1a in zebrafish embryos resulting in disruption of the normal PGC migration pattern. A transgenic line of zebrafish, Tg(hsp70:sdf1a-nanos3, EGFP), was generated that expresses Sdf1a under the control of the heat-shock protein 70 (hsp70) promoter and nanos3 3?UTR. To better visualize the PGCs, the Tg(hsp70:sdf1a-nanos3, EGFP) fish were crossed with another transgenic line, Tg(kop:DsRed-nanos3), that expresses DsRed driven by the PGC-specific kop promoter. Heat treatment of the transgenic embryos caused an induction of Sdf1a expression throughout the embryo resulting in the disruption of their normal migration. Optimal embryo survival and disruption of PGC migration was achieved when transgenic embryos at the 4- to 8-cell stage were incubated at 34.5°C for 18 hours. Under these conditions, disruption of PGC migration was observed in 100% of the embryos. Sixty-four adult fish were developed from three separate batches of heat-treated embryos and all were found to be infertile males. When each male was paired with a wild-type female, only unfertilized eggs were produced and histological examination revealed that each of the adult male fish possessed severely under-developed gonads that lacked gametes. The results demonstrate that inducible Sdf1a expression is an efficient and reliable strategy to produce infertile fish. This approach makes it convenient to generate large numbers of infertile adult fish while also providing the capability to maintain a fertile brood stock. PMID:23826390

  9. Radiation-Induced Alopecia after Endovascular Embolization under Fluoroscopy

    PubMed Central

    Ounsakul, Vipawee; Iamsumang, Wimolsiri

    2016-01-01

    Radiation-induced alopecia after fluoroscopically guided procedures is becoming more common due to an increasing use of endovascular procedures. It is characterized by geometric shapes of nonscarring alopecia related to the area of radiation. We report a case of a 46-year-old man presenting with asymptomatic, sharply demarcated rectangular, nonscarring alopecic patch on the occipital scalp following cerebral angiography with fistula embolization under fluoroscopy. His presentations were compatible with radiation-induced alopecia. Herein, we also report a novel scalp dermoscopic finding of blue-grey dots in a target pattern around yellow dots and follicles, which we detected in the lesion of radiation-induced alopecia. PMID:28074164

  10. Thermodynamic models of radiation-induced processes in solids

    NASA Astrophysics Data System (ADS)

    Yurov, V. M.; Eremin, E. N.; Kasymov, S. S.; Laurinas, V. CH; Chernyavskii, A. V.

    2017-01-01

    A thermodynamic model is proposed to qualitatively describe the radiation-induced processes in solids: temperature dependence of the X-ray radio luminescence output, dependence of these processes on the excitation density, energy accumulating in a solid under exposure to ionizing radiation and its temperature dependence. The proposed model and the formula derived can be used to develop radiation-resistant and radiation-sensitive materials.

  11. Effects of gamma radiation on development, sterility, fecundity, and sex ratio of Dermanyssus gallinae (DeGeer) (Acari: Dermanyssidae)

    SciTech Connect

    Entrekin, D.L.; Oliver, J.H. Jr.; Pound, J.M.

    1987-06-01

    Protonymphal Dermanyssus gallinae were irradiated with 0.50, 0.75, 1.0, 3.0, and 6.0 krad of gamma radiation and subsequently monitored regarding their developmental, feeding, and mating success. Also, sex ratios of adults treated as protonymphs were recorded as were sex ratios of embryos and F1 adults produced by these adults. Doses up to 1.0 krad did not prevent development of treated protonymphs to the adult stage or stop mating. Three krad reduced the number of treated protonymphs attaining adulthood and 6.0-krad treatment prevented all mites from developing to the adult stage. Egg (embryo) production was normal for mites treated with 0.50 krad, but significantly curtailed by doses of 0.75 krad and greater. Radiation doses used in this study did not appear to affect the normal variable sex ratios observed in untreated mites.

  12. Male-sterile and cleistogamous phenotypes in tall fescue induced by chimeric repressors of SUPERWOMAN1 and OsMADS58.

    PubMed

    Sato, Hiroko; Yoshida, Kouki; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Takamizo, Tadashi

    2012-02-01

    Since tall fescue (Festuca arundinacea Schreb.) is an anemophilous (wind-pollinated) grass species, male sterility is strongly desired for transgenic tall fescue to prevent pollen dispersal. To create male-sterile tall fescue, we applied Chimeric REpressor gene-Silencing Technology (CRES-T) based on rice APETALA3 (AP3) and AGAMOUS (AG) orthologues that specify the formation of stamens. We fused the coding regions of rice AP3 orthologue SUPERWOMAN1 (SPW1), and rice AG orthologues, Os12g0207000, Os01g0886200 and OsMADS58, respectively with the artificial sequence encoding the modified EAR-like motif repression domain (SRDX). We first introduced Os12g0207000SRDX, Os01g0886200SRDX and OsMADS58SRDX into rice for evaluation of their abilities to induce male sterility. The transgenic rice expressing OsMADS58SRDX had reiterated formation of lodicule-like organs instead of stamens and carpel, a typical phenotype of ag mutant. Thus, we found that OsMADS58SRDX was most suitable for our purpose. Next, we introduced SPW1SRDX and OsMADS58SRDX into tall fescue. Although the transgenic tall fescue did not have the stamen alterations seen in SPW1SRDX and OsMADS58SRDX rice, they either produced no pollen or produced immature pollen; thus, the anthers were not dehiscent and the plants were male-sterile. In addition to the male sterility, SPW1SRDX tall fescue showed a cleistogamous (closed) phenotype in which anthers were not observed outside the glumes, with thin, abnormally elongated lodicules. Some lines of OsMADS58SRDX tall fescue showed a cleistogamous phenotype in which the lodicules were homeotically transformed into lemma-like organs. In both cases, cleistogamous phenotype was associated with morphological changes to the lodicules. We also obtained a mild phenotype of OsMADS58SRDX tall fescue, which exhibited only the male sterility. In this study, we produced novel male-sterile phenotypes using chimeric repressors and thus suggest CRES-T as a tool for transgenic improvement

  13. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    NASA Astrophysics Data System (ADS)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  14. Analog of microwave-induced resistance oscillations induced in GaAs heterostructures by terahertz radiation

    NASA Astrophysics Data System (ADS)

    Herrmann, T.; Dmitriev, I. A.; Kozlov, D. A.; Schneider, M.; Jentzsch, B.; Kvon, Z. D.; Olbrich, P.; Bel'kov, V. V.; Bayer, A.; Schuh, D.; Bougeard, D.; Kuczmik, T.; Oltscher, M.; Weiss, D.; Ganichev, S. D.

    2016-08-01

    We report on the study of terahertz radiation-induced MIRO-like oscillations of magnetoresistivity in GaAs heterostructures. Our experiments provide an answer on two most intriguing questions—effect of radiation helicity and the role of the edges—yielding crucial information for an understanding of the MIRO (microwave-induced resistance oscillations) origin. Moreover, we demonstrate that the range of materials exhibiting radiation-induced magneto-oscillations can be largely extended by using high-frequency radiation.

  15. Modelling stellar proton event-induced particle radiation dose on close-in exoplanets

    NASA Astrophysics Data System (ADS)

    Atri, Dimitra

    2017-02-01

    Kepler observations have uncovered the existence of a large number of close-in exoplanets and serendipitously of stellar superflares with emissions several orders of magnitude higher than those observed on the Sun. The interaction between the two and their implications on planetary habitability are of great interest to the community. Stellar proton events (SPEs) interact with planetary atmospheres, generate secondary particles and increase the radiation dose on the surface. This effect is amplified for close-in exoplanets and can be a serious threat to potential planetary life. Monte Carlo simulations are used to model the SPE-induced particle radiation dose on the surface of such exoplanets. The results show a wide range of surface radiation doses on planets in close-in configurations with varying atmospheric column depths, magnetic moments and orbital radii. It can be concluded that for close-in exoplanets with sizable atmospheres and magnetospheres, the radiation dose contributed by stellar superflares may not be high enough to sterilize a planet (for life as we know it) but can result in frequent extinction level events. In light of recent reports, the interaction of hard-spectrum SPEs with the atmosphere of Proxima Centauri b is modelled and their implications on its habitability are discussed.

  16. [Spontaneous and radiation-induced chromosome breaks].

    PubMed

    Lebedeva, L I; Chubykin, V L

    1975-01-01

    It is shown by the study of the location of acentric fragments of chromosomes at metaphase and anaphase in the root cells of pea (cultivar "Capital"), in the cornea of rats (strain Wistar), in the bone marrow of mice (strain BALB), in the cultures of embryonic fibroblasts of mice (strain C57B1) and of embryonic human fibroblasts that some fragments are situated outside the equatorial plates, while others are situated within the plane of the equatorial plate. The fragments of the first type initiate mainly spontaneously, while the fragments of the second type are mainly induced by irradiation. These principles are observed in all the types of animal and plant cells studied. The location of the fragments observed in non-radiated cells could be explained if it be assumed, that all the chromosome breaks are realized before the prometaphase and by the beginning of the prometaphase the fragments are randomly distributed within the volume of the nucleus. At the prometaphase most fragments move from the equator to the pole of the cell and thus at the metaphase and anaphase are found to be located outside the equatorial plate. For the explanation of the observed ratio of the two types of fragments in an irradiated cell it is assumed that chromosome fragments resulting from breaks induced by irradiation are completely detached from chromosomes only after the beginning of the prometaphase. Possibly, the process of development of breaks is also not yet completed by this time, it continues and is completed at the metaphase, partially, at the anaphase of the mitosis.

  17. Radiation-induced degradation of DNA bases

    NASA Astrophysics Data System (ADS)

    Douki, T.; Delatour, T.; Martini, R.; Cadet, J.

    1999-01-01

    Radio-induced degradation of DNA involves radical processes. A series of lesions among the major bases degradation products has been measured in isolated DNA exposed to gamma radiation in aerated aqueous solution. Degradation can be accounted for by the formation of hydroxyl radicals upon radiolysis of water (indirect effect). The four bases are degraded in high yield. Direct effect has been mimicked by photo-induced electron abstraction from the bases producing their radical cation. Quantification of the modified bases showed that guanine is the preferential target. This can be explained by its lower oxidation potential and charge transfer phenomena. La décomposition radio-induite de l'ADN fait intervenir des processus radicalaires. Une série de lésions choisies parmi les produits majeurs de dégradation des bases a été mesurée dans de l'ADN isolé exposé au rayonnement en solution aqueuse aérée. Les modifications sont alors dues aux radicaux hydroxyles produits par la radiolyse de l'eau (effet indirect) et les quatre bases sont efficacement dégradées. L'arrachement d'électrons aux bases par photosensibilisation pour produire leur radical cation, a été utilisé comme modèle de l'effet direct. La quantification des bases modifiées montre que la guanine est préférentiellement dégradée. Cette observation peut s'expliquer par le plus faible potentiel d'oxydation de cette base ainsi que par les phénomènes de transfert de charge vers les guanines.

  18. Radiation-induced degradation of aqueous fluoranthene

    NASA Astrophysics Data System (ADS)

    Popov, Petar; Getoff, Nikola

    2005-01-01

    The radiation-induced degradation of fluoranthene (FA) in slightly alkaline aqueous solution was investigated in the presence of air as well as of N 2O. Depending on the starting FA-concentration the determined Gi(-FA) was 0.34 for 1×10 -5 mol/l FA upto 0.67 for 4.6×10 -5 mol/l FA. As major radiolytic products found by HPLC-analysis were: 9-fluorene carboxylic acid ( Gi =0.006), 9-fluorenone ( Gi=0.004) and fluorene ( Gi=0.002) in addition to a mixture of carboxylic acids and aldehydes. In the presence of N 2O (90% OH, 10% H) practically the same products were observed, however in this case the yield of the carboxylic acids was about 2-times higher than in solutions saturated with air, but 4-times less aldehydes, resp. For illustration of the rather complicated degradation process a probable reaction mechanism is presented.

  19. Pathogenesis and Prevention of Radiation-induced Myocardial Fibrosis

    PubMed

    Liu, Li Kun; Ouyang, Weiwei; Zhao, Xing; Su, Sheng Fa; Yang, Yan; Ding, Wen Jin; Luo, Da Xian; He, Zhi Xu; Lu, Bing

    2017-03-01

    Radiation therapy is one of the most important methods for the treatment of malignant tumors. However, in radiotherapy for thoracic tumors such as breast cancer, lung cancer, esophageal cancer, and mediastinal lymphoma, the heart, located in the mediastinum, is inevitably affected by the irradiation, leading to pericardial disease, myocardial fibrosis, coronary artery disease, valvular lesions, and cardiac conduction system injury, which are considered radiation-induced heart diseases. Delayed cardiac injury especially myocardial fibrosis is more prominent, and its incidence is as high as 20–80%. Myocardial fibrosis is the final stage of radiation-induced heart diseases, and it increases the stiffness of the myocardium and decreases myocardial systolic and diastolic function, resulting in myocardial electrical physiological disorder, arrhythmia, incomplete heart function, or even sudden death. This article reviews the pathogenesis and prevention of radiation-induced myocardial fibrosis for providing references for the prevention and treatment of radiation-induced myocardial fibrosis. Creative Commons Attribution License

  20. The "drought-inducible" histone H1s of tobacco play no role in male sterility linked to alterations in H1 variants.

    PubMed

    Przewloka, Marcin R; Wierzbicki, Andrzej T; Slusarczyk, Joanna; Kuraś, Mieczyslaw; Grasser, Klaus D; Stemmer, Christian; Jerzmanowski, Andrzej

    2002-07-01

    Tobacco ( Nicotiana tabacum L.) has two major H1 variants (H1A and H1B), which account for over 80% of chromatin linker histones, and four minor variants: H1C, H1D, H1E and H1F. We have shown previously [M. Prymakowska-Bosak et al. (1999) Plant Cell 11:2317-2329] that reversal of the natural proportion of major to minor H1 variants in transgenic tobacco plants results in a characteristic male-sterility phenotype identical to that occurring in many plant species subjected to water deficit at the time of male meiosis. It has been proposed by others that the drought-induced arrest of male gametophyte development is linked to decreased sugar delivery to reproductive tissues. Within the family of angiosperm H1s there is a well-defined class of minor H1 variants named "drought inducible" because some of its members have been shown to be induced by water deficit. We have identified and cloned the tobacco H1C gene, which, based on sequence similarity, represents a "drought-inducible" minor H1 variant. Analysis of the un-translated mRNA and promoter regions of H1C suggests a regulation by sucrose concentration. Antisense silencing of H1C and its close homologue H1D in plants that do not express H1A and H1B does not affect the characteristic H1A(-)/ H1B(-) male-sterility phenotype. Silencing of H1C and H1D also has no effect on growth and development of plants. Our findings demonstrate that H1C and H1D are dispensable for normal growth and development of tobacco, and that the compensatory up-regulation of "drought-inducible" H1s observed in H1A(-)/ H1B(-) plants is not the direct cause of male sterility linked to alterations in H1 variants.

  1. Ionizing Radiation-Induced Endothelial Cell Senescence and Cardiovascular Diseases

    PubMed Central

    Wang, Yingying; Boerma, Marjan; Zhou, Daohong

    2016-01-01

    Exposure to ionizing radiation induces not only apoptosis but also senescence. While the role of endothelial cell apoptosis in mediating radiation-induced acute tissue injury has been extensively studied, little is known about the role of endothelial cell senescence in the pathogenesis of radiation-induced late effects. Senescent endothelial cells exhibit decreased production of nitric oxide and expression of thrombomodulin, increased expression of adhesion molecules, elevated production of reactive oxygen species and inflammatory cytokines and an inability to proliferate and form capillary-like structures in vitro. These findings suggest that endothelial cell senescence can lead to endothelial dysfunction by dysregulation of vasodilation and hemostasis, induction of oxidative stress and inflammation and inhibition of angiogenesis, which can potentially contribute to radiation-induced late effects such as cardiovascular diseases (CVDs). In this article, we discuss the mechanisms by which radiation induces endothelial cell senescence, the roles of endothelial cell senescence in radiation-induced CVDs and potential strategies to prevent, mitigate and treat radiation-induced CVDs by targeting senescent endothelial cells. PMID:27387862

  2. Radiation induces senescence and a bystander effect through metabolic alterations.

    PubMed

    Liao, E-C; Hsu, Y-T; Chuah, Q-Y; Lee, Y-J; Hu, J-Y; Huang, T-C; Yang, P-M; Chiu, S-J

    2014-05-22

    Cellular senescence is a state of irreversible growth arrest; however, the metabolic processes of senescent cells remain active. Our previous studies have shown that radiation induces senescence of human breast cancer cells that display low expression of securin, a protein involved in control of the metaphase-anaphase transition and anaphase onset. In this study, the protein expression profile of senescent cells was resolved by two-dimensional gel electrophoresis to investigate associated metabolic alterations. We found that radiation induced the expression and activation of glyceraldehyde-3-phosphate dehydrogenase that has an important role in glycolysis. The activity of lactate dehydrogenase A, which is involved in the conversion of pyruvate to lactate, the release of lactate and the acidification of the extracellular environment, was also induced. Inhibition of glycolysis by dichloroacetate attenuated radiation-induced senescence. In addition, radiation also induced activation of the 5'-adenosine monophosphate-activated protein kinase (AMPK) and nuclear factor kappa B (NF-κB) pathways to promote senescence. We also found that radiation increased the expression of monocarboxylate transporter 1 (MCT1) that facilitates the export of lactate into the extracellular environment. Inhibition of glycolysis or the AMPK/NF-κB signalling pathways reduced MCT1 expression and rescued the acidification of the extracellular environment. Interestingly, these metabolic-altering signalling pathways were also involved in radiation-induced invasion of the surrounding, non-irradiated breast cancer and normal endothelial cells. Taken together, radiation can induce the senescence of human breast cancer cells through metabolic alterations.

  3. Dose-dependent radiation-induced hypotension in the canine

    SciTech Connect

    Cockerham, L.G.; Hampton, J.D.; Doyle, T.F.

    1986-01-01

    Radiation-induced early transient incapacitation (ETI) is often accompanied by severe systemic hypotension. However, postradiation hypotension does not occur with equal frequency in all species and is not reported with consistency in the canine. In an attempt to clarify the differences in reported canine post-radiation blood pressures, canine systemic blood pressures were determined both before and after exposure to gamma radiation of either 80 or 100 Gy. Data obtained from six sham-radiated beagles and 12 radiated beagles indicated that 100-Gy, whole-body, gamma radiation produced a decrease in systemic mean blood pressure while 80-Gy, whole-body, gamma radiation did not. Analysis of this data could be consistent with a quantal response to a gamma radiation dose between 80 Gy and 100 Gy.

  4. Plasma Sterilization: New Epoch in Medical Textiles

    NASA Astrophysics Data System (ADS)

    Senthilkumar, P.; Arun, N.; Vigneswaran, C.

    2015-04-01

    Clothing is perceived to be second skin to the human body since it is in close contact with the human skin most of the times. In hospitals, use of textile materials in different forms and sterilization of these materials is an essential requirement for preventing spread of germs. The need for appropriate disinfection and sterilization techniques is of paramount importance. There has been a continuous demand for novel sterilization techniques appropriate for use on various textile materials as the existing sterilization techniques suffer from various technical and economical drawbacks. Plasma sterilization is the alternative method, which is friendlier and more effective on the wide spectrum of prokaryotic and eukaryotic microorganisms. Basically, the main inactivation factors for cells exposed to plasma are heat, UV radiation and various reactive species. Plasma exposure can kill micro-organisms on a surface in addition to removing adsorbed monolayer of surface contaminants. Advantages of plasma surface treatment are removal of contaminants from the surface, change in the surface energy and sterilization of the surface. Plasma sterilization aims to kill and/or remove all micro-organisms which may cause infection of humans or animals, or which can cause spoilage of foods or other goods. This review paper emphasizes necessity for sterilization, essentials of sterilization, mechanism of plasma sterilization and the parameters influencing it.

  5. Selenomethionine protects against adverse biological effects induced by space radiation.

    PubMed

    Kennedy, Ann R; Ware, Jeffrey H; Guan, Jun; Donahue, Jeremiah J; Biaglow, John E; Zhou, Zhaozong; Stewart, Jelena; Vazquez, Marcelo; Wan, X Steven

    2004-01-15

    Ionizing radiation-induced adverse biological effects impose serious challenges to astronauts during extended space travel. Of particular concern is the radiation from highly energetic, heavy, charged particles known as HZE particles. The objective of the present study was to characterize HZE particle radiation-induced adverse biological effects and evaluate the effect of D-selenomethionine (SeM) on the HZE particle radiation-induced adverse biological effects. The results showed that HZE particle radiation can increase oxidative stress, cytotoxicity, and cell transformation in vitro, and decrease the total antioxidant status in irradiated Sprague-Dawley rats. These adverse biological effects were all preventable by treatment with SeM, suggesting that SeM is potentially useful as a countermeasure against space radiation-induced adverse effects. Treatment with SeM was shown to enhance ATR and CHK2 gene expression in cultured human thyroid epithelial cells. As ionizing radiation is known to result in DNA damage and both ATR and CHK2 gene products are involved in DNA damage, it is possible that SeM may prevent HZE particle radiation-induced adverse biological effects by enhancing the DNA repair machinery in irradiated cells.

  6. Lipotransfer for radiation-induced skin fibrosis.

    PubMed

    Kumar, R; Griffin, M; Adigbli, G; Kalavrezos, N; Butler, P E M

    2016-07-01

    Radiation-induced fibrosis (RIF) is a late complication of radiotherapy that results in progressive functional and cosmetic impairment. Autologous fat has emerged as an option for soft tissue reconstruction. There are also sporadic reports suggesting regression of fibrosis following regional lipotransfer. This systematic review aimed to identify cellular mechanisms driving RIF, and the potential role of lipotransfer in attenuating these processes. PubMed, OVID and Google Scholar databases were searched to identify all original articles regarding lipotransfer for RIF. All articles describing irradiated fibroblast or myofibroblast behaviour were included. Data elucidating the mechanisms of RIF, role of lipotransfer in RIF and methods to quantify fibrosis were extracted. Ninety-eight studies met the inclusion criteria. A single, definitive model of RIF is yet to be established, but four cellular mechanisms were identified through in vitro studies. Twenty-one studies identified connective tissue growth factor and transforming growth factor β1 cytokines as drivers of fibrotic cascades. Hypoxia was demonstrated to propagate fibrogenesis in three studies. Oxidative stress from the release of reactive oxygen species and free radicals was also linked to RIF in 11 studies. Purified autologous fat grafts contain cellular and non-cellular properties that potentially interact with these processes. Six methods for quantifying fibrotic changes were evaluated including durometry, ultrasound shear wave elastography, thermography, dark field imaging, and laser Doppler and laser speckle flowmetry. Understanding how lipotransfer causes regression of RIF remains unclear; there are a number of new hypotheses for future research. © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.

  7. MSI's unique, multi-functional contract sterilization facility

    NASA Astrophysics Data System (ADS)

    Morganstern, Kennard H.

    Medical Sterilization Inc. is a unique company supplying sterilization services to regional hospitals in the New York area and also providing contract sterilization and radiation processing services to industry. The evolution from a concept to an operational entity is reviewed in this report.

  8. Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

    NASA Astrophysics Data System (ADS)

    Bednarz, Bryan; Besemer, Abigail

    2017-09-01

    The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

  9. Low-oxygen atmospheric treatment improves the performance of irradiation-sterilized male cactus moths used in SIT.

    PubMed

    López-Martínez, Giancarlo; Carpenter, James E; Hight, Stephen D; Hahn, Daniel A

    2014-02-01

    As part of sterile insect technique (SIT) programs, irradiation can effectively induce sterility in insects by damaging genomic DNA. However, irradiation also induces other off-target side effects that reduce the quality and performance of sterilized males. Thus, treatments that reduce off-target effects of irradiation on male performance while maintaining sterility can improve the feasibility and economy of SIT programs. Exposure to ionizing radiation induces the formation of damaging free radicals in biological systems that may reduce sterile male performance. Here, we test whether exposure to an anoxic environment for 1 h before and during irradiation improves male performance, while maintaining sterility in males of the cactus moth, Cactoblastis cactorum (Berg). We show that exposure to 1 h of anoxia increases the moth's antioxidant capacity and that irradiation in anoxia after 1 h of anoxic conditioning decreases irradiation-induced oxidative damage to the moth's lipids and proteins. Anoxia treatment that reduced oxidative damage after irradiation also produced moths with greater flight performance, mating success, and longevity, while maintaining F1 male sterility at acceptable levels for SIT. We conclude that anoxia pretreatment followed by irradiation in anoxia is an efficient way to improve the quality of irradiated moths and perhaps lower the number of moths needed for release SIT moth operations.

  10. Radiation-Induced Impairment of Neuronal Excitability

    DTIC Science & Technology

    1988-01-01

    population spike. A dose rate of 20 Gy/min shifts to the left the dose response curve for radiation at 5 Gy/min. At 5 Gy/min, significant deficits...postsynaptic damage is likely to result from a different molecular mechanism. 100 , , t 50 0) 000 FIUR 2 6 5 200Radiation Dose (Gy) FIGURE 2 Dose response curve of

  11. Simulating Space Radiation-Induced Breast Tumor Incidence Using Automata.

    PubMed

    Heuskin, A C; Osseiran, A I; Tang, J; Costes, S V

    2016-07-01

    Estimating cancer risk from space radiation has been an ongoing challenge for decades primarily because most of the reported epidemiological data on radiation-induced risks are derived from studies of atomic bomb survivors who were exposed to an acute dose of gamma rays instead of chronic high-LET cosmic radiation. In this study, we introduce a formalism using cellular automata to model the long-term effects of ionizing radiation in human breast for different radiation qualities. We first validated and tuned parameters for an automata-based two-stage clonal expansion model simulating the age dependence of spontaneous breast cancer incidence in an unexposed U.S. We then tested the impact of radiation perturbation in the model by modifying parameters to reflect both targeted and nontargeted radiation effects. Targeted effects (TE) reflect the immediate impact of radiation on a cell's DNA with classic end points being gene mutations and cell death. They are well known and are directly derived from experimental data. In contrast, nontargeted effects (NTE) are persistent and affect both damaged and undamaged cells, are nonlinear with dose and are not well characterized in the literature. In this study, we introduced TE in our model and compared predictions against epidemiologic data of the atomic bomb survivor cohort. TE alone are not sufficient for inducing enough cancer. NTE independent of dose and lasting ∼100 days postirradiation need to be added to accurately predict dose dependence of breast cancer induced by gamma rays. Finally, by integrating experimental relative biological effectiveness (RBE) for TE and keeping NTE (i.e., radiation-induced genomic instability) constant with dose and LET, the model predicts that RBE for breast cancer induced by cosmic radiation would be maximum at 220 keV/μm. This approach lays the groundwork for further investigation into the impact of chronic low-dose exposure, inter-individual variation and more complex space radiation

  12. Clinical and dosimetric factors of radiation-induced esophageal injury: Radiation-induced esophageal toxicity

    PubMed Central

    Qiao, Wen-Bo; Zhao, Yan-Hui; Zhao, Yan-Bin; Wang, Rui-Zhi

    2005-01-01

    AIM: To analyze the clinical and dosimetric predictive factors for radiation-induced esophageal injury in patients with non-small-cell lung cancer (NSCLC) during three-dimensional conformal radiotherapy (3D-CRT). METHODS: We retrospectively analyzed 208 consecutive patients (146 men and 62 women) with NSCLC treated with 3D-CRT. The median age of the patients was 64 years (range 35-87 years). The clinical and treatment parameters including gender, age, performance status, sequential chemotherapy, concurrent chemotherapy, presence of carinal or subcarinal lymph nodes, pretreatment weight loss, mean dose to the entire esophagus, maximal point dose to the esophagus, and percentage of volume of esophagus receiving >55 Gy were studied. Clinical and dosimetric factors for radiation-induced acute and late grade 3-5 esophageal injury were analyzed according to Radiation Therapy Oncology Group (RTOG) criteria. RESULTS: Twenty-five (12%) of the two hundred and eight patients developed acute or late grade 3-5 esophageal injury. Among them, nine patients had both acute and late grade 3-5 esophageal injury, two died of late esophageal perforation. Concurrent chemotherapy and maximal point dose to the esophagus ≥60 Gy were significantly associated with the risk of grade 3-5 esophageal injury. Fifty-four (26%) of the two hundred and eight patients received concurrent chemotherapy. Among them, 25 (46%) developed grade 3-5 esophageal injury (P = 0.0001<0.01). However, no grade 3-5 esophageal injury occurred in patients who received a maximal point dose to the esophagus <60 Gy (P = 0.0001<0.01). CONCLUSION: Concurrent chemotherapy and the maximal esophageal point dose ≥60 Gy are significantly associated with the risk of grade 3-5 esophageal injury in patients with NSCLC treated with 3D-CRT. PMID:15849822

  13. Heavy-ion radiation induced bystander effect in mice

    NASA Astrophysics Data System (ADS)

    Liang, Shujian; Sun, Yeqing; Zhang, Meng; Wang, Wei; Cui, Changna

    2012-07-01

    Radiation-induced bystander effect is defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, Low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic, metabolomics and proteomics play significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male mice head were exposed to 2000mGy dose of 12C heavy-ion radiation and the distant organ liver was detected on 1h, 6h, 12h and 24h after radiation, respectively. MSAP was used to monitor the level of polymorphic DNA methylation changes. The results show that heavy-ion irradiate mouse head can induce liver DNA methylation changes significantly. The percent of DNA methylation changes are time-dependent and highest at 6h after radiation. We also prove that the hypo-methylation changes on 1h and 6h after irradiation. But the expression level of DNA methyltransferase DNMT3a is not changed. UPLC/Synapt HDMS G2 was employed to detect the proteomics of bystander liver 1h after irradiation. 64 proteins are found significantly different between treatment and control group. GO process show that six of 64 which were unique in irradiation group are associated with apoptosis and DNA damage response. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

  14. Radiation-induced charge trapping in bipolar base oxides

    SciTech Connect

    Fleetwood, D.M.; Riewe, L.C.; Witczak, Schrimpf, R.D.

    1996-03-01

    Capacitance-voltage and thermally stimulated current methods are used to investigate radiation induced charge trapping in bipolar base oxides. Results are compared with models of oxide and interface trap charge buildup at low electric fields.

  15. Sterilization of collagen scaffolds designed for peripheral nerve regeneration: Effect on microstructure, degradation and cellular colonization.

    PubMed

    Monaco, Graziana; Cholas, Rahmatullah; Salvatore, Luca; Madaghiele, Marta; Sannino, Alessandro

    2017-02-01

    In this study we investigated the impact of three different sterilization methods, dry heat (DHS), ethylene oxide (EtO) and electron beam radiation (β), on the properties of cylindrical collagen scaffolds with longitudinally oriented pore channels, specifically designed for peripheral nerve regeneration. Scanning electron microscopy, mechanical testing, quantification of primary amines, differential scanning calorimetry and enzymatic degradation were performed to analyze possible structural and chemical changes induced by the sterilization. Moreover, in vitro proliferation and infiltration of the rat Schwann cell line RSC96 within the scaffolds was evaluated, up to 10days of culture. No major differences in morphology and compressive stiffness were observed among scaffolds sterilized by the different methods, as all samples showed approximately the same structure and stiffness as the unsterilized control. Proliferation, infiltration, distribution and morphology of RSC96 cells within the scaffolds were also comparable throughout the duration of the cell culture study, regardless of the sterilization treatment. However, we found a slight increase of chemical crosslinking upon sterilization (EtOsterilized scaffolds. The results demonstrated that β irradiation impaired the scaffold properties to a greater extent, whereas EtO exposure appeared as the most suitable method for the sterilization of the proposed scaffolds. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Radiation-induced myeloid leukemia in murine models

    PubMed Central

    2014-01-01

    The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included. PMID:25062865

  17. Radiation-induced myeloid leukemia in murine models.

    PubMed

    Rivina, Leena; Davoren, Michael; Schiestl, Robert H

    2014-07-25

    The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included.

  18. Genetic variation in radiation-induced cell death.

    PubMed

    Smirnov, Denis A; Brady, Lauren; Halasa, Krzysztof; Morley, Michael; Solomon, Sonia; Cheung, Vivian G

    2012-02-01

    Radiation exposure through environmental, medical, and occupational settings is increasingly common. While radiation has harmful effects, it has utility in many applications such as radiotherapy for cancer. To increase the efficacy of radiation treatment and minimize its risks, a better understanding of the individual differences in radiosensitivity and the molecular basis of radiation response is needed. Here, we integrated human genetic and functional genomic approaches to study the response of human cells to radiation. We measured radiation-induced changes in gene expression and cell death in B cells from normal individuals. We found extensive individual variation in gene expression and cellular responses. To understand the genetic basis of this variation, we mapped the DNA sequence variants that influence expression response to radiation. We also identified radiation-responsive genes that regulate cell death; silencing of these genes by small interfering RNA led to an increase in radiation-induced cell death in human B cells, colorectal and prostate cancer cells. Together these results uncovered DNA variants that contribute to radiosensitivity and identified genes that can be targeted to increase the sensitivity of tumors to radiation.

  19. [Optimal terms for sterilization].

    PubMed

    Ribic-Pucelj, M

    1980-01-01

    Sterilization can be performed in the immediate postpartum, post abortion, or as an interval procedure. Traditionally, postpartum sterilization should be performed within the first two days after delivery, thereafter the risk for infection is believed to increase. Sterilization and artificial abortion are performed as concomitant procedures, while interval sterilization is carried out at least six weeks after the termination of pregnancy. Though many authors consider the sterilization in the immediate postpartum and postabortion period safe enough, the comparative studies show that interval sterilization has less complications. Postpartum (postabortion) sterilization has much more disadvantages than advantages in comparison to interval sterilization. The main advantage of postpartum sterilization is only one hospitalization while disadvantages are the increased risk of hemorrhage, uterine perforation, thromboembolic disease, infection, technical difficulties, and psychological problems. For these reasons interval sterilization is recommended.

  20. Radiation-induced coronary artery disease

    SciTech Connect

    Dunsmore, L.D.; LoPonte, M.A.; Dunsmore, R.A.

    1986-07-01

    This report describes three patients who developed myocardial infarction at an untimely age, 4 to 12 years after radiation therapy for Hodgkin's disease. These cases lend credence to the cause and effect relation of such therapy to coronary artery disease.

  1. Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

    PubMed Central

    Rana, Sudha; Kumar, Raj; Sultana, Sarwat; Sharma, Rakesh Kumar

    2010-01-01

    Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation. PMID:21829314

  2. [Update in radiation-induced neoplasms: genetic studies].

    PubMed

    Chauveinc, Laurent; Lefevre, Sandrine; Malfoy, Bernard; Dutrillaux, Bernard

    2002-02-01

    Radiation induced tumors are a possible (very) late complications of radiotherapy. The evaluation of the risks of radiation-induced tumors has been presented in different epidemiological studies, with the evaluation of the relative risk for different tissues. But, the genetic studies are rare, and no global theory exists. Two cytogenetic profiles are described, one with translocations and one with genetic material losses, evoking two different genetic evolutions. Two questions are stated. What are the radiation-induced genetic mechanisms? Is it possible to differentiate the radiation-induced and spontaneous tumors with genetic approaches? With 37 cytogenetic cases, 12 analyzed in our laboratory, the radiation-induced tumors were characterized by genetic material losses. An anti-oncogenic evolution is probable. A new molecularly study confirm these results. Only thyroid tumors do not have this evolution. For tumors with simple karyotype, like meningioma, radiation-induced tumors seem to be more complex than spontaneous tumors. But for the others, the differentiation is impossible to be done with cytogenetic. The mechanism of the chromosomic material losses in unknown, but some hypothesis are discussed.

  3. Risk and survival outcomes of radiation-induced CNS tumors.

    PubMed

    Lee, Jessica W; Wernicke, A Gabriella

    2016-08-01

    Patients treated with cranial radiation are at risk of developing secondary CNS tumors. Understanding the incidence, treatment, and long-term outcomes of radiation-induced CNS tumors plays a role in clinical decision-making and patient education. Additionally, as meningiomas and pituitary tumors have been detected at increasing rates across all ages and may potentially be treated with radiation, it is important to know and communicate the risk of secondary tumors in children and adults. After conducting an extensive literature search, we identified publications that report incidence and long-term outcomes of radiation-induced CNS tumors. We reviewed 14 studies in children, which reported that radiation confers a 7- to 10-fold increase in subsequent CNS tumors, with a 20-year cumulative incidence ranging from 1.03 to 28.9 %. The latency period for secondary tumors ranged from 5.5 to 30 years, with gliomas developing in 5-10 years and meningiomas developing around 15 years after radiation. We also reviewed seven studies in adults, where the two strongest studies showed no increased risk while the remaining studies found a higher risk compared to the general population. The latency period for secondary CNS tumors in adults ranged from 5 to 34 years. Treatment and long-term outcomes of radiation-induced CNS tumors have been documented in four case series, which did not conclusively demonstrate that secondary CNS tumors fared worse than primary CNS tumors. Radiation-induced CNS tumors remain a rare occurrence that should not by itself impede radiation treatment. Additional investigation is needed on the risk of radiation-induced tumors in adults and the long-term outcomes of these tumors.

  4. Atomic evidence that modification of H-bonds established with amino acids critical for host-cell binding induces sterile immunity against malaria

    SciTech Connect

    Patarroyo, Manuel E.; Cifuentes, Gladys; Pirajan, Camilo; Moreno-Vranich, Armando; Vanegas, Magnolia

    2010-04-09

    Based on the 3D X-ray crystallographic structures of relevant proteins of the malaria parasite involved in invasion to host cells and 3D NMR structures of High Activity Binding Peptides (HABPs) and their respective analogues, it was found that HABPs are rendered into highly immunogenic and sterile immunity inducers in the Aotus experimental model by modifying those amino acids that establish H-bonds with other HABPs or binding to host's cells. This finding adds striking and novel physicochemical principles, at the atomic level, for a logical and rational vaccine development methodology against infectious disease, among them malaria.

  5. Characterization of chemical-induced sterile inflammation in vitro: application of the model compound ketoconazole in a human hepatic co-culture system.

    PubMed

    Wewering, Franziska; Jouy, Florent; Wissenbach, Dirk K; Gebauer, Scarlett; Blüher, Matthias; Gebhardt, Rolf; Pirow, Ralph; von Bergen, Martin; Kalkhof, Stefan; Luch, Andreas; Zellmer, Sebastian

    2017-02-01

    Liver injury as a result of a sterile inflammation is closely linked to the activation of immune cells, including macrophages, by damaged hepatocytes. This interaction between immune cells and hepatocytes is as yet not considered in any of the in vitro test systems applied during the generation of new drugs. Here, we established and characterized a novel in vitro co-culture model with two human cell lines, HepG2 and differentiated THP-1. Ketoconazole, an antifungal drug known for its hepatotoxicity, was used as a model compound in the testing of the co-culture. Single cultures of HepG2 and THP-1 cells were studied as controls. Different metabolism patterns of ketoconazole were observed for the single and co-culture incubations as well as for the different cell types. The main metabolite N-deacetyl ketoconazole was found in cell pellets, but not in supernatants of cell cultures. Global proteome analysis showed that the NRF2-mediated stress response and the CXCL8 (IL-8) pathway were induced by ketoconazole treatment under co-culture conditions. The upregulation and ketoconazole-induced secretion of several pro-inflammatory cytokines, including CXCL8, TNF-α and CCL3, was observed in the co-culture system only, but not in single cell cultures. Taking together, we provide evidence that the co-culture model applied might be suitable to serve as tool for the prediction of chemical-induced sterile inflammation in liver tissue in vivo.

  6. UV – INDUCED SYNTHESIS OF AMINO ACIDS FROM AQUEOUS STERILIZED SOLUTION OF AMMONIUM FORMATE AND AMMONIA UNDER HETROGENEOUS CONDITIONS

    PubMed Central

    Bisht, G.; Bisht, L. S.

    1990-01-01

    Irradiation of sterilized aqueous solution of ammonium formate and ammonia with UV light in the presence and or absence of certain inorganic sensitizers for 25 hrs. gave six ninhydrin positive products in appreciable amounts. Out of the six products observed fiver were characterized as lysine, serine, glutemic acid, n-amino butyric acid and leucine. The sensitizing effect of additives on ammonium formate was observed in the order; uranium oxide > ammonium formate > ferric oxide > arsenic oxide. PMID:22556511

  7. The second intron of AGAMOUS drives carpel- and stamen-specific expression sufficient to induce complete sterility in Arabidopsis.

    PubMed

    Liu, Zongrang; Liu, Zhongchi

    2008-05-01

    Gene containment technologies that prevent transgene dispersal through pollen, fruit and seed are in immediate demand to address concerns of gene flow from transgenic crops into wild species or close relatives. In this study, we isolated the enhancer element of Arabidopsis AGAMOUS that drives gene expression specifically in stamens and carpels. By fusing this AG enhancer to a minimal 35S promoter fragment, two tissue-specific promoters, fAGIP and rAGIP in forward and reverse orientations, respectively, were created and fused to the GUS reporter. Transgenic Arabidopsis plants harboring either fAGIP::GUS or rAGIP::GUS displayed similar GUS expression specifically in carpel and stamen tissues and their primordial cells. To test their utility for engineering sterility, the promoters were fused to the Diphtheria toxin A (DT-A) gene coding for a ribosome inactivating protein as well as the Barnase gene coding for an extracellular ribonuclease, and tested for tissue-specific ablation. Over 89% of AGIP::DT-A and 68% of AGIP::Barnase transgenic plants displayed specific and precise ablation of stamens and carpels and are completely sterile. These transgenic plants showed normal vegetative development with prolonged vegetative growth. To evaluate the stability of the sterile phenotype, 16 AGIP::DT-A lines underwent two consecutive cutback generations and showed no reversion of the floral phenotype. This study demonstrates a simple, precise and efficient approach to achieve absolute sterility through irreversible ablation of both male and female floral organs. This approach should have a practical application for transgene containment in ornamental, landscaping, and woody species, whose seeds and fruits are of no economic value.

  8. Radiation-induced malignant and atypical peripheral nerve sheath tumors

    SciTech Connect

    Foley, K.M.; Woodruff, J.M.; Ellis, F.T.; Posner, J.B.

    1980-04-01

    The reported peripheral nerve complications of therapeutic irradiation in humans include brachial and lumbar plexus fibrosis and cranial and peripheral nerve atrophy. We have encountered 9 patients with malignant (7) and atypical (2) peripheral nerve tumors occurring in an irradiated site suggesting that such tumors represent another delayed effect of radiation treatment on peripheral nerve. In all instances the radio-theray was within an acceptable radiation dosage, yet 3 patients developed local radiation-induced skin and bony abnormalities. The malignant peripheral nerve sheath tumors developed only in the radiation port. Animal studies support the clinical observation that malignant peripheral nerve sheath tumors can occur as a delayed effect of irradiation.

  9. Pathology and biology of radiation-induced cardiac disease

    PubMed Central

    Tapio, Soile

    2016-01-01

    Heart disease is the leading global cause of death. The risk for this disease is significantly increased in populations exposed to ionizing radiation, but the mechanisms are not fully elucidated yet. This review aims to gather and discuss the latest data about pathological and biological consequences in the radiation-exposed heart in a comprehensive manner. A better understanding of the molecular and cellular mechanisms underlying radiation-induced damage in heart tissue and cardiac vasculature will provide novel targets for therapeutic interventions. These may be valuable for individuals clinically or occupationally exposed to varying doses of ionizing radiation. PMID:27422929

  10. Radiation Induced DNA Double-Strand Breaks in Radiology.

    PubMed

    Kuefner, M A; Brand, M; Engert, C; Schwab, S A; Uder, M

    2015-10-01

    Shortly after the discovery of X-rays, their damaging effect on biological tissues was observed. The determination of radiation exposure in diagnostic and interventional radiology is usually based on physical measurements or mathematical algorithms with standardized dose simulations. γ-H2AX immunofluorescence microscopy is a reliable and sensitive method for the quantification of radiation induced DNA double-strand breaks (DSB) in blood lymphocytes. The detectable amount of these DNA damages correlates well with the dose received. However, the biological radiation damage depends not only on dose but also on other individual factors like radiation sensitivity and DNA repair capacity. Iodinated contrast agents can enhance the x-ray induced DNA damage level. After their induction DSB are quickly repaired. A protective effect of antioxidants has been postulated in experimental studies. This review explains the prinicple of the γ-H2AX technique and provides an overview on studies evaluating DSB in radiologic examinations. Radiologic examinations including CT and angiography induce DNA double-strand breaks. Even after mammography a slight but significant increase is detectable in peripheral blood lymphocytes. The number of radiation induced double-strand breaks correlates well with the radiation dose. Individual factors including radiation sensitivity, DNA repair capacity and the application of iodinated contrast media has an influence on the DNA damage level. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Faecal microbiota transplantation protects against radiation-induced toxicity.

    PubMed

    Cui, Ming; Xiao, Huiwen; Li, Yuan; Zhou, Lixin; Zhao, Shuyi; Luo, Dan; Zheng, Qisheng; Dong, Jiali; Zhao, Yu; Zhang, Xin; Zhang, Junling; Lu, Lu; Wang, Haichao; Fan, Saijun

    2017-04-01

    Severe radiation exposure may cause acute radiation syndrome, a possibly fatal condition requiring effective therapy. Gut microbiota can be manipulated to fight against many diseases. We explored whether intestinal microbe transplantation could alleviate radiation-induced toxicity. High-throughput sequencing showed that gastrointestinal bacterial community composition differed between male and female mice and was associated with susceptibility to radiation toxicity. Faecal microbiota transplantation (FMT) increased the survival rate of irradiated animals, elevated peripheral white blood cell counts and improved gastrointestinal tract function and intestinal epithelial integrity in irradiated male and female mice. FMT preserved the intestinal bacterial composition and retained mRNA and long non-coding RNA expression profiles of host small intestines in a sex-specific fashion. Despite promoting angiogenesis, sex-matched FMT did not accelerate the proliferation of cancer cells in vivo FMT might serve as a therapeutic to mitigate radiation-induced toxicity and improve the prognosis of tumour patients after radiotherapy.

  12. Thermodynamic processes induced by coherent radiation

    NASA Technical Reports Server (NTRS)

    Garbuny, M.

    1977-01-01

    It is shown by quantum statistics that under certain stated conditions the entropy of coherent radiation is zero and it is still negligible for multimode laser operation. This makes possible gas kinetic processes which, to a small extent, have already been observed or even utilized, but which can be greatly enhanced by an optimized choice of molecular structures and radiation conditions. Radiative cooling of gases is discussed in detail. The conditions for maximum heat withdrawal are derived, and it is proposed that the processes of cooling and relaxation heating can be sufficiently separated in time to achieve certain effects and thermodynamic cycles. One of these is the complete conversion, possible in principle, of coherent radiation into work. This concept is based on a heat pump process followed by heat-to-work conversion, the heat rejected being just equal to that withdrawn by radiation. The conditions for complete conversion turn out to be the same as for maximum heat withdrawal. The feasibility of these processes depends on the degree to which practical conditions can be met, and on the validity of certain assumptions which have to await experimental verification.

  13. Thermodynamic processes induced by coherent radiation

    NASA Technical Reports Server (NTRS)

    Garbuny, M.

    1977-01-01

    It is shown by quantum statistics that under certain stated conditions the entropy of coherent radiation is zero and it is still negligible for multimode laser operation. This makes possible gas kinetic processes which, to a small extent, have already been observed or even utilized, but which can be greatly enhanced by an optimized choice of molecular structures and radiation conditions. Radiative cooling of gases is discussed in detail. The conditions for maximum heat withdrawal are derived, and it is proposed that the processes of cooling and relaxation heating can be sufficiently separated in time to achieve certain effects and thermodynamic cycles. One of these is the complete conversion, possible in principle, of coherent radiation into work. This concept is based on a heat pump process followed by heat-to-work conversion, the heat rejected being just equal to that withdrawn by radiation. The conditions for complete conversion turn out to be the same as for maximum heat withdrawal. The feasibility of these processes depends on the degree to which practical conditions can be met, and on the validity of certain assumptions which have to await experimental verification.

  14. Optical imaging of radiation-induced metabolic changes in radiation-sensitive and resistant cancer cells

    NASA Astrophysics Data System (ADS)

    Alhallak, Kinan; Jenkins, Samir V.; Lee, David E.; Greene, Nicholas P.; Quinn, Kyle P.; Griffin, Robert J.; Dings, Ruud P. M.; Rajaram, Narasimhan

    2017-06-01

    Radiation resistance remains a significant problem for cancer patients, especially due to the time required to definitively determine treatment outcome. For fractionated radiation therapy, nearly 7 to 8 weeks can elapse before a tumor is deemed to be radiation-resistant. We used the optical redox ratio of FAD/(FAD+NADH) to identify early metabolic changes in radiation-resistant lung cancer cells. These radiation-resistant human A549 lung cancer cells were developed by exposing the parental A549 cells to repeated doses of radiation (2 Gy). Although there were no significant differences in the optical redox ratio between the parental and resistant cell lines prior to radiation, there was a significant decrease in the optical redox ratio of the radiation-resistant cells 24 h after a single radiation exposure (p=0.01). This change in the redox ratio was indicative of increased catabolism of glucose in the resistant cells after radiation and was associated with significantly greater protein content of hypoxia-inducible factor 1 (HIF-1α), a key promoter of glycolytic metabolism. Our results demonstrate that the optical redox ratio could provide a rapid method of determining radiation resistance status based on early metabolic changes in cancer cells.

  15. Radioprotectors and Mitigators of Radiation-Induced Normal Tissue Injury

    PubMed Central

    Cotrim, Ana P.; Hyodo, Fuminori; Baum, Bruce J.; Krishna, Murali C.; Mitchell, James B.

    2010-01-01

    Radiation is used in the treatment of a broad range of malignancies. Exposure of normal tissue to radiation may result in both acute and chronic toxicities that can result in an inability to deliver the intended therapy, a range of symptoms, and a decrease in quality of life. Radioprotectors are compounds that are designed to reduce the damage in normal tissues caused by radiation. These compounds are often antioxidants and must be present before or at the time of radiation for effectiveness. Other agents, termed mitigators, may be used to minimize toxicity even after radiation has been delivered. Herein, we review agents in clinical use or in development as radioprotectors and mitigators of radiation-induced normal tissue injury. Few agents are approved for clinical use, but many new compounds show promising results in preclinical testing. PMID:20413641

  16. Hyperprolactinemia from radiation-induced hypothalamic hypopituitarism

    SciTech Connect

    Corkill, G.; Hanson, F.W.; Gold, E.M.; White, V.A.

    1980-01-01

    In 1975 Samaan et al., described the effects of radiation damage of the hypothalamus in 15 patients with head and neck cancer. Shalet et al., in 1977 described endocrine morbidity in adults who as children had been irradiated for brain tumors. This report describes instances of hyperprolactinemia and associated hypothalamic, pituitary, and thyroid dysfunction following irradiation of a young adult female for brain neoplasia.

  17. RADIATION INDUCED VULCANIZATION OF RUBBER LATEX

    DOEpatents

    Mesrobian, R.B.; Ballantine, D.S.; Metz, D.J.

    1964-04-28

    A method of vulcanizing rubber latex by exposing a mixture containing rubber latex and from about 15 to about 21.3 wt% of 2,5-dichlorostyrene to about 1.1 megarads of gamma radiation while maintaining the temperature of the mixture at a temperature ranging between from about 56 to about 59 deg C is described. (AEC)

  18. Neutron Radiation Induced Degradation of Diode Characteristics

    DTIC Science & Technology

    1992-12-01

    de fluance utilis6 dans ce travail (diode du type 3). La plupart des r~sultats anterieurs sur les, diodes A jonction p-n correspondent aux rdsultats...termes des thories pour une jonction p-n et pour les effects de radiations sur semiconducteurs. II est prddit qu’une diode du type 3 pourrait &tre

  19. Factors Associated with Occurrence of Radiation-induced Optic Neuropathy at "Safe" Radiation Dosage.

    PubMed

    Doroslovački, Pavle; Tamhankar, Madhura A; Liu, Grant T; Shindler, Kenneth S; Ying, Gui-Shuang; Alonso-Basanta, Michelle

    2017-07-13

    Radiation-induced optic neuropathy (RION) is a rare, and often visually devastating, complication of radiation therapy (RT) near the anterior visual pathways. A retrospective case series of patients who developed RION at a tertiary medical center, followed by a case-control study comparing RION cases with matched controls who received RT. Thirteen patients (18 eyes) with RION were identified. Radiation modalities included external beam photon radiation, whole brain radiation, stereotactic radiosurgery, proton beam, and unknown. Most patients received doses below published "safe" thresholds (<55 Gy; <8-10 Gy for stereotactic radiosurgery). There was no statistically significant difference in prevalence of vasculopathic factors between cases and controls; on subgroup analysis in three patients who received surprisingly low radiation doses, smoking (p=0.05) and hypertension (p=0.02) appeared more prevalent. RION can occur at doses below published "safe" thresholds and with different RT modalities. Smoking and hypertension might be risk factors for RION.

  20. Novel Radiomitigator for Radiation-Induced Bone Loss

    NASA Technical Reports Server (NTRS)

    Schreurs, A-S; Shirazi-fard, Y.; Terada, M.; Alwood, J. S.; Steczina, S.; Medina, C.; Tahimic, C. G. T.; Globus, R. K.

    2016-01-01

    Radiation-induced bone loss can occur with radiotherapy patients, accidental radiation exposure and during long-term spaceflight. Bone loss due to radiation is due to an early increase in oxidative stress, inflammation and bone resorption, resulting in an imbalance in bone remodeling. Furthermore, exposure to high-Linear Energy Transfer (LET) radiation will impair the bone forming progenitors and reduce bone formation. Radiation can be classified as high-LET or low-LET based on the amount of energy released. Dried Plum (DP) diet prevents bone loss in mice exposed to total body irradiation with both low-LET and high-LET radiation. DP prevents the early radiation-induced bone resorption, but furthermore, we show that DP protects the bone forming osteoblast progenitors from high-LET radiation. These results provide insight that DP re-balances the bone remodeling by preventing resorption and protecting the bone formation capacity. This data is important considering that most of the current osteoporosis treatments only block the bone resorption but do not protect bone formation. In addition, DP seems to act on both the oxidative stress and inflammation pathways. Finally, we have preliminary data showing the potential of DP to be radio-protective at a systemic effect and could possible protect other tissues at risk of total body-irradiation such as skin, brain and heart.

  1. Characterization of radiation-induced emesis in the ferret

    SciTech Connect

    King, G.L.

    1988-01-01

    Forty-eight ferrets (Mustela putorius furo) were individually head-shielded and radiated with bilateral cobalt 60 gamma radiation at 100 cGy min at doses ranging between 49 and 601 cGy. The emetic threshold was observed at 69 cGy, the ED 50 was calculated as 77 cGy, and 100% incidence of emesis occurred at 201 cGy. With increasing doses of radiation, the latency to first emesis after radiation decreased dramatically, whereas the duration of the prodromal period increased. Two other sets of experiments suggest that dopaminergic mechanisms play a minor role in radiation-induced emesis in the ferret. Twenty-two animals were injected either intravenously or subcutaneously with 30 to 300 micrograms /kg of apomorphine. Fewer than 50% of the animals vomited to 300 micrograms/kg apomorphine; central dopaminergic receptor activation was apparent at all doses. Another eight animals received 1 mg/kg domperidone prior to either 201 (n=4) or 401 (n=4) cGy radiation and their emetic responses were compared with NaCi-injected-irradiated controls (n=8). At 201 cGy, domperidone significantly reduced only the total time in emetic behavior. At 401 cGy, domperidone had no salutary effect on radiation-induced emesis. The emetic responses of the ferret to radiation and apomorphine are compared with these responses in other vomiting species.

  2. Characterization of radiation-induced emesis in the ferret

    SciTech Connect

    King, G.L.

    1988-06-01

    Forty-eight ferrets (Mustela putorius furo) were individually head-shielded and radiated with bilateral /sup 60/Co gamma radiation at 100 cGy min-1 at doses ranging between 49 and 601 cGy. The emetic threshold was observed at 69 cGy, the ED50 was calculated at 77 cGy, and 100% incidence of emesis occurred at 201 cGy. With increasing doses of radiation, the latency to first emesis after radiation decreased dramatically, whereas the duration of the prodromal period increased. Two other sets of experiments suggest that dopaminergic mechanisms play a minor role in radiation-induced emesis in the ferret. Twenty-two animals were injected either intravenously or subcutaneously with 30 to 300 micrograms/kg of apomorphine. Fewer than 50% of the animals vomited to 300 micrograms/kg apomorphine; central dopaminergic receptor activation was apparent at all doses. Another eight animals received 1 mg/kg domperidone prior to either 201 (n = 4) or 401 (n = 4) cGy radiation and their emetic responses were compared with NaCl-injected-irradiated controls (n = 8). At 201 cGy, domperidone significantly reduced only the total time in emetic behavior. At 401 cGy, domperidone had no salutary effect on radiation-induced emesis. The emetic responses of the ferret to radiation and apomorphine are compared with these responses in other vomiting species.

  3. Use of probiotics for prevention of radiation-induced diarrhea

    PubMed Central

    Delia, P; Sansotta, G; Donato, V; Frosina, P; Messina, G; De Renzis, C; Famularo, G

    2007-01-01

    AIM: To investigate the efficacy of a high-potency probiotic preparation on prevention of radiation-induced diarrhea in cancer patients. METHODS: This was a double-blind, placebo-controlled trial. Four hundred and ninety patients who underwent adjuvant postoperative radiation therapy after surgery for sigmoid, rectal, or cervical cancer were assigned to either the high-potency probiotic preparation VSL#3 (one sachet t.i.d.,) or placebo starting from the first day of radiation therapy. Efficacy endpoints were incidence and severity of radiation-induced diarrhea, daily number of bowel movements, and the time from the start of the study to the use of loperamide as rescue medication. RESULTS: More placebo patients had radiation-induced diarrhea than VSL#3 patients (124 of 239 patients, 51.8%, and 77 of 243 patients, 31.6%; P < 0.001) and more patients given placebo suffered grade 3 or 4 diarrhea compared with VSL#3 recipients (55.4% and 1.4%, P < 0.001). Daily bowel movements were 14.7 ± 6 and 5.1 ± 3 among placebo and VSL#3 recipients (P < 0.05), and the mean time to the use of loperamide was 86 ± 6 h for placebo patients and 122 ± 8 h for VSL#3 patients (P < 0.001). CONCLUSION: Probiotic lactic acid-producing bacteria are an easy, safe, and feasible approach to protect cancer patients against the risk of radiation-induced diarrhea. PMID:17352022

  4. Radiation-induced cognitive impairment-from bench to bedside

    PubMed Central

    Greene-Schloesser, Dana; Robbins, Mike E.

    2012-01-01

    Approximately 100 000 patients per year in the United States with primary and metastatic brain tumor survive long enough (>6 months) to develop radiation-induced brain injury. Before 1970, the human brain was thought to be radioresistant; the acute central nervous system (CNS) syndrome occurs after single doses of ≥30 Gy, and white matter necrosis can occur at fractionated doses of ≥60 Gy. Although white matter necrosis is uncommon with modern radiation therapy techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become increasingly important, having profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenic mechanisms involved in radiation-induced cognitive impairment. Although reductions in hippocampal neurogenesis and hippocampal-dependent cognitive function have been observed in rodent models, it is important to recognize that other brain regions are affected; non–hippocampal-dependent reductions in cognitive function occur. Neuroinflammation is viewed as playing a major role in radiation-induced cognitive impairment. During the past 5 years, several preclinical studies have demonstrated that interventional therapies aimed at modulating neuroinflammation can prevent/ameliorate radiation-induced cognitive impairment independent of changes in neurogenesis. Translating these exciting preclinical findings to the clinic offers the promise of improving the quality of life in patients with brain tumors who receive radiation therapy. PMID:23095829

  5. Histological changes induced by 15 F CO2 laser microprobe especially designed for root canal sterilization: an in-vivo study

    NASA Astrophysics Data System (ADS)

    Kesler, Gavriel; Koren, Rumelia; Gal, Rivka

    1998-04-01

    Until now, no suitable delivery fiber existed for CO2 laser endodontic radiation in the apical region where it is most difficult to eliminate the pulp tissue using conventional methods. To overcome this problem, we designed a microprobe that reaches closer to the apex, distributing the energy density to a smaller area of the root canal, thus favorably increasing the thermal effects. The 15 F CO2 microprobe is a flexible, hollow, metal fiber, 300 micrometer in diameter and 20 mm in length, coupled onto a handpiece, with the following radiation parameters: wavelength -- 10.6 micrometer; pulse duration -- 50m/sec; energy per pulse 0.25 joule; energy density -- 353.7J/cm2 per pulse; power on tissue -- 5 W. The study was conducted on 30 vital maxillary or mandibulary; central, lateral, or premolar teeth destined for extraction due to periodontal problems. Twenty were experimentally treated with pulsed CO2 laser delivered by this newly developed fiber after conventional root canal preparation. Temperature measured at three points on the root surface during laser treatment did not exceed 38 degrees Celsius. Ten teeth represented the control group in which only root canal preparation was performed in the conventional method. Histological examination of the laser treated teeth showed coagulation necrosis and vacuolization of remaining pulp tissue in the root canal periphery. Primary and secondary dentin appeared normal, in all cases treated with 15 F CO2 laser. Gramm stain and bacteriologic examination revealed complete sterilization. These results demonstrate the unique capabilities of this special microprobe in sterilization of the root canal, and no thermal damage to the surrounding tissue.

  6. Case 242: Radiation-induced Angiosarcoma.

    PubMed

    Disharoon, Meredith; Kozlowski, Kamilia F; Kaniowski, Jessica M

    2017-06-01

    History In 2004, this woman received a diagnosis of invasive mammillary carcinoma, tubular variant, strongly positive for estrogen and progesterone receptors. Her lesion was found at screening mammography performed at an outside institution when she was 59 years old. She underwent partial mastectomy, with partial axillary node dissection and sentinel node mapping. A 0.6 × 0.5 cm Nottingham grade 1 infiltrating ductal carcinoma was removed from the right upper outer quadrant, margins were free of tumor, and there was no angiolymphatic invasion. The six dissected lymph nodes were negative for malignancy. Her surgical history was otherwise unremarkable. Her medical history was positive for hypercholesterolemia and depression. Pertinent family history included breast cancer in both her mother and her sister. Given the patient's age, tumor size, lack of nodal involvement, and clear surgical margins, she met recommended MammoSite criteria, and she underwent accelerated partial breast radiation. She subsequently received 340 cGy of radiation twice a day for a total dose of 3400 cGy in 10 administrations in February 2005. Accelerated partial breast radiation treatment was completed in February 2005, and she received subsequent routine care. Prior to 2014, the only postoperative complication was a chronic radiation bed seroma, which required periodic percutaneous drainage. She did not develop postsurgical lymphedema. In December 2013, 9 years after accelerated partial breast radiation treatment, she experienced progressive painful pruritic breast fullness, skin dimpling, and skin discoloration of the mastectomy scar and radiation bed. She sought medical care in January 2014 after she noticed a periareolar ulcerating skin plaque, more noticeable nipple retraction, and new onset of retroareolar aching. At physical examination ( Fig 1 ), there was generalized periareolar erythema, dimpling, firmness, and fixation involving the central breast and right upper outer quadrant

  7. Sterilization of glycerin.

    PubMed

    McCluskey, Susan V

    2008-06-15

    The sterilization of glycerin is described. Glycerin is used in a wide variety of pharmaceutical formulations, including oral, otic, ophthalmic, topical, and parenteral preparations. Of the myriad uses for glycerin, some require a sterile solution. Due to the nature of dry heat sterilization with resulting equipment and validation needs, sterile filtration is the preferred sterilization method for glycerin at the Mayo Clinic Pharmacy Services Production Laboratory in Rochester, Minnesota. A practical procedure was attained with the use of a chemically compatible 0.22-microm capsule filter, peristaltic pump, and sterile tubing. The sterile tubing is attached firmly, with a twisting motion, to the hose barb ends of the filter. The peristaltic pump is set at minimum speed, and a sterile syringe is used to capture the sterile glycerin filtrate. After filtration, filter integrity testing using the bubble point test is performed on the filter used to sterilize the solution. Packaging was then completed by placing glycerin aliquots into unit-of-use sterile syringes, placing a sterile tip cap on each syringe, and labeling the syringe. End testing is needed for preparations, such as sterile glycerin, that are made from nonsterile components, regardless of sterilization technique. This quality-control testing includes but is not limited to visual checks, pH checks, and tests for bacterial endotoxins, particulate matter, and sterility. Beyond-use dating is then assigned based on chemical, physical, microbiological, and packaging considerations. A practical method for sterilization of glycerin by compounding pharmacists is attainable through the use of membrane filtration. Sterility assurance is achieved through appropriate validation, and quality-control checks must be completed before release of the injectable preparation.

  8. Influence of Radiation Sterilization on Properties of Biodegradable Lactide/Glycolide/Trimethylene Carbonate and Lactide/Glycolide/ε-caprolactone Porous Scaffolds with Shape Memory Behavior

    PubMed Central

    Rychter, Piotr; Śmigiel-Gac, Natalia; Pamuła, Elżbieta; Smola-Dmochowska, Anna; Janeczek, Henryk; Prochwicz, Wojciech; Dobrzyński, Piotr

    2016-01-01

    The aim of the study was the evaluation of gamma irradiation and electron beams for sterilization of porous scaffolds with shape memory behavior obtained from biodegradable terpolymers: poly(l-lactide-co-glycolide-co-trimethylene carbonate) and poly(l-lactide-co-glycolide-co-ɛ-caprolactone). The impact of mentioned sterilization techniques on the structure of the scaffolds before and after the sterilization process using irradiation doses ranged from 10 to 25 kGy has been investigated. Treatment of the samples with gamma irradiation at 15 kGy dose resulted in considerable drop in glass transition temperature (Tg) and number average molecular weight (Mn). For comparison, after irradiation of the samples using an electron beam with the same dose, no significant changes in structure or properties of examined scaffolds have been noticed. Higher doses of irradiation via electron beam caused essential changes of the scaffolds’ pores resulting in partial melting of their surface. Nevertheless, obtained results have revealed that sterilization with electron beam, when compared to gamma irradiation, is a better method because it does not affect significantly the physicochemical properties of the scaffolds. Both used methods of sterilization did not influence the shape memory behavior of the examined materials. PMID:28787864

  9. Radiation recall dermatitis induced by trastuzumab.

    PubMed

    Moon, Dochang; Koo, Ja Seung; Suh, Chang-Ok; Yoon, Chang Yun; Bae, Jaehyun; Lee, Soohyeon

    2016-01-01

    We report a case of radiation recall dermatitis caused by trastuzumab. A 55-year-old woman with metastatic breast cancer received palliative first-line trastuzumab/paclitaxel and a salvage partial mastectomy with lymph node dissection was subsequently performed. In spite of the palliative setting, the pathology report indicated that no residual carcinoma was present, and then she underwent locoregional radiotherapy to ensure a definitive response. After radiotherapy, she has maintained trastuzumab monotherapy. Nine days after the fifth cycle of trastuzumab monotherapy, dermatitis in previously irradiated skin developed, with fever. Radiation recall dermatitis triggered by trastuzumab is extremely rare. A high fever developed abruptly with a skin rash. This may be the first case of this sort to be reported.

  10. Mitigation of radiation induced surface contamination

    DOEpatents

    Klebanoff, Leonard E.; Stulen, Richard H.

    2003-01-01

    A process for mitigating or eliminating contamination and/or degradation of surfaces having common, adventitious atmospheric contaminants adsorbed thereon and exposed to radiation. A gas or a mixture of gases is introduced into the environment of a surface(s) to be protected. The choice of the gaseous species to be introduced (typically a hydrocarbon gas, water vapor, or oxygen or mixtures thereof) is dependent upon the contaminant as well as the ability of the gaseous species to bind to the surface to be protected. When the surface and associated bound species are exposed to radiation reactive species are formed that react with surface contaminants such as carbon or oxide films to form volatile products (e.g., CO, CO.sub.2) which desorb from the surface.

  11. DECOHERENCE EFFECTS OF MOTION-INDUCED RADIATION

    SciTech Connect

    P. NETO; D. DALVIT

    2000-12-01

    The radiation pressure coupling with vacuum fluctuations gives rise to energy damping and decoherence of an oscillating particle. Both effects result from the emission of pairs of photons, a quantum effect related to the fluctuations of the Casimir force. We discuss different alternative methods for the computation of the decoherence time scale. We take the example of a spherical perfectly-reflecting particle, and consider the zero and high temperature limits. We also present short general reviews on decoherence and dynamical Casimir effect.

  12. Variations in the structure and transcription of the mitochondrial atp and cox genes in wild Solanum species that induce male sterility in eggplant (S. melongena).

    PubMed

    Yoshimi, M; Kitamura, Y; Isshiki, S; Saito, T; Yasumoto, K; Terachi, T; Yamagishi, H

    2013-07-01

    In order to determine the molecular basis of cytoplasmic male sterility (CMS) in alloplasmic lines of eggplant, the genomic structures and transcription patterns of mitochondrial ATP synthase subunit (atp) and cytochrome oxidase subunit (cox) genes were studied for wild and cultivated eggplants. Alloplasmic eggplant lines with cytoplasms of wild Solanum species showing either anther indehiscent type of CMS or non-pollen production type of CMS were studied with the cultivated eggplant Solanum melongena, used as a control. Southern hybridization of the mitochondrial genes indicated the difference between the two types of CMS and showed complete identity within each type. The cytoplasmic patterns of all wild species differed from that of the cultivated eggplant. Thus, the cytoplasm of the six wild eggplants and the one cultivated eggplant was classified into three groups. Male sterile plants of both types of CMS showed novel transcription patterns of atp1, whereas a different transcription pattern of cox2 was observed only in the anther indehiscent type. Based on these differences, we determined the DNA sequences of about a 4 kbp segment in the atp1 region. Although the coding and 3' flanking regions were almost identical among the cytoplasms, the 5' flanking region was completely different and novel open reading frames (orfs) were found for each of the CMS types and the cultivated eggplant. The cytoplasm of Solanum kurzii inducing the anther indehiscent type CMS had orf312, and those of Solanum aethiopicum and Solanum grandifolium of non-pollen production type CMS had orf218. The correspondence between the transcription patterns of these orfs and phenotypic expression of male sterility strongly suggests that these orfs are causal genes for each type of CMS.

  13. Sterile insect technique: A model for dose optimisation for improved sterile insect quality

    SciTech Connect

    Parker, A.

    2007-03-15

    The sterile insect technique (SIT) is an environment-friendly pest control technique with application in the area-wide integrated control of key pests, including the suppression or elimination of introduced populations and the exclusion of new introductions. Reproductive sterility is normally induced by ionizing radiation, a convenient and consistent method that maintains a reasonable degree of competitiveness in the released insects. The cost and effectiveness of a control program integrating the SIT depend on the balance between sterility and competitiveness, but it appears that current operational programs with an SIT component are not achieving an appropriate balance. In this paper we discuss optimization of the sterilization process and present a simple model and procedure for determining the optimum dose. (author) [Spanish] La tecnica de insecto esteril (TIE) es una tecnologia de control de plagas favorable para el medio ambiente con una aplicacion de un control integrado de plagas claves para toda la area, incluyendo la supresion o eliminacion de poblaciones introducidas y la exclusion de nuevas introducciones. La esterilidad reproductiva es normalmente inducida por radiacion ionizada, un metodo conveniente y consistente que mantiene un grado razonable para la capacidad de competencia en insectos liberados. El costo y la eficacia de un programa de control que incluye TIE dependen en tener un balance entre la esterilidad y la capacidad para competir, pero parece que los programas operacionales corrientes con TIS como un componente no estan logrando el tener un balance apropiado. En esta publicacion, nosotros discutimos la optimizacion del proceso de esterilizacion y presentamos un modelo y procedimiento sencillos para determinar la dosis optima. (author)

  14. [Nonsurgical treatment of chronic radiation-induced hemorrhagic proctitis].

    PubMed

    de Parades, Vincent; Bauer, Pierre; Marteau, Philippe; Chauveinc, Laurent; Bouillet, Thierry; Atienza, Patrick

    2008-01-01

    The incidence of radiation-induced chronic hemorrhagic proctitis is less than 10 to 20%. The onset of this proctitis is delayed relative to the radiation therapy and generally develops from 6 to 24 months later. There are numerous predisposing factors, the most important of which is the radiation therapy dose: risk increases exponentially above 40-45 Gy. Its pathophysiology involves progressive obliterating endarteritis and transmural interstitial fibrosis, which induce chronic ischemia that is irreversible and progressive during the years after radiation therapy. Its diagnosis depends most often on the combination of clinical history and typical endoscopic appearance (congestive mucosa and/or telangiectases). Topical administrative of sucralfate or corticosteroids as well as argon plasma coagulation, with formalin treatment if necessary, provides relief for most patients.

  15. Sterilizing the Poor

    ERIC Educational Resources Information Center

    Rothman, Sheila M.

    1977-01-01

    Suggests that freedom for the middle classes may mean vulnerability for the poor. The enthusiasm for sterilization may be so intense as to deprive the poor of their right not to be sterilized. (Author/AM)

  16. [Complications of tubal sterilization].

    PubMed

    Schreiner, W E

    1986-05-01

    In Europe and the US, tubal sterilization by laparoscopy has become the most widely used technique for female sterilization. The overall rate of intra- and postoperative complications differs between 0.145% and 0.85% in the numerous studies which have been done. This means 1 severe complication in 120-700 laparoscopic sterilizations. The lethality of tubal sterilization by laparoscopy lies between 3-10 deaths/100,000 interventions. The so-called "post-tubal ligation syndrome" is a rare complication. The overall pregnancy rate after tubal sterilization is 3-10/1000 women. The rate of ectopic pregnancy is very high and varies between 13.6% and 90%. Only 5% of the sterilized women show dissatisfaction. Several factors are relevant with regard to psychological sequelae and must be considered before tubal sterilization can be performed. 1 of the most important is the individual comprehensive counselling of the female or the couple prior to the sterilization.

  17. Process and Radiation Induced Defects in Electronic Materials and Devices

    NASA Technical Reports Server (NTRS)

    Washington, Kenneth; Fogarty, T. N.

    1997-01-01

    Process and radiation induced defects are characterized by a variety of electrical techniques, including capacitance-voltage measurements and charge pumping. Separation of defect type into stacking faults, displacement damage, oxide traps, interface states, etc. and their related causes are discussed. The defects are then related to effects on device parameters. Silicon MOS technology is emphasized. Several reviews of radiation effects and silicon processing exist.

  18. Process and Radiation Induced Defects in Electronic Materials and Devices

    NASA Technical Reports Server (NTRS)

    Washington, Kenneth; Fogarty, T. N.

    1997-01-01

    Process and radiation induced defects are characterized by a variety of electrical techniques, including capacitance-voltage measurements and charge pumping. Separation of defect type into stacking faults, displacement damage, oxide traps, interface states, etc. and their related causes are discussed. The defects are then related to effects on device parameters. Silicon MOS technology is emphasized. Several reviews of radiation effects and silicon processing exist.

  19. Radiation-induced impacts on the degradation of 2,4-D and the microbial population in soil microcosms.

    PubMed

    Niedrée, Bastian; Vereecken, Harry; Burauel, Peter

    2013-01-01

    In a soil microcosm experiment, the influence of low-level (137)Cs and (90)Sr contamination on the degradation of (14)C-ring-labeled 2,4-dichlorophenoxyacetic acid (2,4-D) was studied. Two differently treated soils (one native soil and one soil sterilized and reinoculated with a biotic soil aliquot) were artificially contaminated with various concentrations of (137)Cs and (90)Sr as nitrate salts. The cumulative doses increased up to 4 Gy for 30 days of incubation in soil microcosms. Changes in microbial community structure were observed with help of the denaturing gradient gel electrophoresis (DGGE). A radiation-induced impact appeared only in the microcosms treated with 30 times the maximum contamination appearing in the exclusion zone around reactor 4 in Chernobyl. In contrast to the less contaminated soils, the mineralization of 2,4-D was delayed for 4 days before it recovered. Slight shifts in the microbial communities could be traced to radiation effects. However, other parameters had a major impact on mineralization and community structure. Thus the sterilization and reinoculation and, of course, application of the 2,4-D were predominantly reflected in the (14)CO(2) emissions and the DGGE gel patterns. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Apparatus Circulates Sterilizing Gas

    NASA Technical Reports Server (NTRS)

    Cross, John H.; Schwarz, Ray P.

    1991-01-01

    Apparatus circulates sterilizing gas containing ethylene oxide and chlorofluorocarbon through laboratory or medical equipment. Confines sterilizing gas, circulating it only through parts to be treated. Consists of two units. One delivers ethylene oxide/chlorofluorocarbon gas mixture and removes gas after treatment. Other warms, humidifies, and circulates gas through equipment to be treated. Process provides reliable sterilization with negligible residual toxicity from ethylene oxide. Particularly suitable for sterilization of interiors of bioreactors, heart/lung machines, dialyzers, or other equipment including complicated tubing.

  1. Radiation-induced cataract in astronauts and cosmonauts.

    PubMed

    Rastegar, Noushin; Eckart, Peter; Mertz, Manfred

    2002-07-01

    Opacification of the ocular lens is an important effect of exposure to ionizing radiation. Astronauts and cosmonauts are exposed to relatively high doses of all types of radiation in space, including high-energy particle radiation. A study was initiated to examine the lenses of the eyes of astronauts/cosmonauts to detect signs of radiation-induced cataracts. The aim of this study was to take a first step towards gaining improved, quantitative insight into the risk of radiation-induced cataract associated with long space missions. The lenses of 21 former astronauts and cosmonauts were examined, using an upgraded Topcon SL-45 B Scheimpflug camera system. The degrees of opacification in this group of astronauts and cosmonauts were compared with the measurements in a reference group. This reference group was established by examining a cohort of 395 persons using the same Scheimpflug system. Initial results indicated that opacity values in most of the astronauts and cosmonauts were slightly to strongly increased in regions IV (posterior cortex) and V (posterior capsule), compared with the average opacity values for the respective age-group of the reference cohort. The aim of this study - to conduct first examinations of astronauts' and cosmonauts' ocular lenses with regard to signs of radiation-induced cataract - was successfully achieved in a total of 21 astronauts and cosmonauts using a Scheimpflug camera system. It is planned to examine a larger group of astronauts and cosmonauts in the future.

  2. Inhibition of radiation-induced polyuria by histamine receptor antagonists

    SciTech Connect

    Donlon, M.A.; Melia, J.A.; Helgeson, E.A.; Wolfe, W.W.

    1986-03-01

    In previous studies the authors have demonstrated that gamma radiation results in polyuria, which is preceded by polydypsia. This suggests that the increased thirst elicited by radiation causes increased urinary volume (UV). Histamine, which is released following radiation exposure, also elicits drinking by nonirradiated rats when administered exogenously. In this study the authors have investigated both the role of water deprivation and the effect of histamine receptor antagonists (HRA) on radiation-induced polyuria. Sprague-Dawley rats were housed individually in metabolic cages. Water was allowed ad libitum except in deprivation experiments where water was removed for 24 hr immediately following radiation. Cimetidine (CIM), an H2 HRA, and dexbromopheniramine (DXB), an H1 HRA, were administered i.p. (16 and 1 mg/kg, respectively) 30 min prior to irradiation (950 rads from a cobalt source). UV was determined at 24-hr intervals for 3 days preceding irradiation and 24 hr postirradiation. UV in DXB treated rats was significantly reduced 24 hr postirradiation (CON = 427 +/- 54%; DXB = 247 +/- 39% of preirradiated CON) compared to postirradiation control values. CIM did not affect postirradiation UV. These data suggest that radiation-induced polyuria is caused by polydypsia which is, in part, mediated by histamine induced by an H1 receptor.

  3. Exaggerated radiation-induced fibrosis in patients with systemic sclerosis

    SciTech Connect

    Varga, J.; Haustein, U.F.; Creech, R.H.; Dwyer, J.P.; Jimenez, S.A. )

    1991-06-26

    Four patients with stable systemic sclerosis and limited skin involvement received radiation for the treatment of solid malignant neoplasms. Following localized irradiation, each patient developed an exaggerated cutaneous and internal fibrotic reaction in the irradiated areas. The surface area of fibrosis extended beyond the radiation portals employed, and the fibrotic process was poorly responsive to antifibrotic therapy. Three of the patients died of complications caused by fibrous encasement of internal organs. The extent and severity of postradiation fibrosis in these patients was distinctly unusual. These observations suggest that patients with systemic sclerosis are particularly susceptible to developing excessive radiation-induced fibrosis.

  4. Peroxidase changes in barley induced by ionizing and thermal radiation.

    PubMed

    Sah, N K; Pramanik, S; Raychaudhuri, S S

    1996-01-01

    Thermal and ionizing (gamma-ray) radiations were used to induce damage to barley seeds (IB65). The activity and isozyme banding patterns of peroxidase were compared. It was found that both physical agents caused damage to barley seeds (as observed from seedling height), but their action on peroxidase activity is not similar. Gamma-Rays enhance peroxidase activity. Thermal radiation, on the other hand, tends to reduce it but fails to alter the number of peroxidase isozymes. It is conjectured that the pathways of damage by thermal and ionizing radiations are not the same.

  5. [Mechanism of cytogenetic adaptive response induced by low dose radiation].

    PubMed

    Cai, L; Liu, S

    1990-11-01

    Cytogenetic observation on human lymphocytes indicated that pre-exposure of 10, 50 and 75 mGy X-rays could induced the adaptive response. Experimental results with different temperature treatment showed that the adaptive response induced by low dose radiation could be enhanced by 41 degrees C and 43 degrees C, but inhibited by 4 degrees C in addition the treatment by 41 degrees C for one hour could also cause the adaptive response as did low dose radiation. Results showed that adaptive response induced by low dose radiation (10 or 50 mGy X-rays) could be eliminated by the protein synthesis inhibitor, implying that the adaptive response is related with the metabolism of cells, especially with the production of certain protective proteins.

  6. Mechanisms of radiation-induced neoplastic cell transformation

    SciTech Connect

    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  7. Low dose radiation-induced endothelial cell retraction.

    PubMed

    Kantak, S S; Diglio, C A; Onoda, J M

    1993-09-01

    We characterized in vitro the effects of gamma-radiation (12.5-100 cGy) on pulmonary microvascular endothelial cell (PMEC) morphology and F-actin organization. Cellular retraction was documented by phase-contrast microscopy and the organization of actin microfilaments was determined by immunofluorescence. Characterization included radiation dose effects, their temporal duration and reversibility of the effects. A dose-dependent relationship between the level of exposure (12.5-100 cGy) and the rate and extent of endothelial retraction was observed. Moreover, analysis of radiation-induced depolymerization of F-actin microfilament stress fibres correlated positively with the changes in PMEC morphology. The depolymerization of the stress fibre bundles was dependent on radiation dose and time. Cells recovered from exposure to reform contact inhibited monolayers > or = 24 h post-irradiation. Concomitantly, the depolymerized microfilaments reorganized to their preirradiated state as microfilament stress fibres arrayed parallel to the boundaries of adjacent contact-inhibited cells. The data presented here are representative of a series of studies designed to characterize low-dose radiation effects on pulmonary microvascular endothelium. Our 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.

  8. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    NASA Technical Reports Server (NTRS)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable

  9. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    NASA Technical Reports Server (NTRS)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable

  10. Radiation Induced Vaccination to Breast Cancer

    DTIC Science & Technology

    2016-12-01

    PET / CT imaging...8 10 time [wk] surivin T cells N01 N01* N03 N05 N09 N10 N14 N02 N04 N15 U03 U07 1mg 10mg healthy controls su rv iv in -r ea ct iv e C D 8+ T c el...r ea ct iv e C D 8+ T c el ls [% o f C D 8+ ] A’ B’ C’ 19 FIGURE 4: Breast cancer patients responded to 10mg Fesolimumab and Radiation

  11. H- - H Collision Induced Radiative Transitions

    NASA Astrophysics Data System (ADS)

    Dadonova, A. V.; Devdariani, A. Z.

    2012-12-01

    Exchange interaction leads to the formation of gerade and ungerade states of temporary molecules (quasimolecules) formed during the H- +H slow collisions. The work deals with the radiation produced by optical transitions between those states. The main characteristics involved in the description of optical transitions in quasimolecules, i.e., energy terms, an optical dipole transition moments, have been calculated in the frame of zero-range potentials model. The main feature of calculations is that the results can be expressed analytically in closed forms via the Lambert W function.

  12. Plasma-Based Sterilization

    DTIC Science & Technology

    2003-07-20

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP014940 TITLE: Plasma-Based Sterilization DISTRIBUTION: Approved for...compilation report: ADP014936 thru ADP015049 UNCLASSIFIED Plasma-Based Sterilization Mounir Laroussi Electrical & Computer Engineering Department Old...Dominion University Norfolk, VA 23529 Rapid, safe, and effective sterilization is of the utmost importance when it comes to protecting the public in

  13. Radiation-induced nonlinear optical response of quartz fibers

    NASA Astrophysics Data System (ADS)

    Plaksin, O. A.

    2006-10-01

    The intensity of radiation-induced luminescence and transient optical losses in KU-1 (Russia) and K-3 (Japan) quartz glass optical tibers irradiated in a fast pulsed fission reactor (a pulse duration of 80 μs and a neutron flux up to 7 × 1016 cm 2 s 2) has been measured in the visible range. The intensity of the fast luminescence component nonlinearly depends on the neutron flux. The luminescence intensity and the transient optical losses depend on the probe light intensity. Suppression of radiation-induced luminescence is observed at wavelengths that are longer or shorter than the probe light wavelength. Light probing leads to an increase in transient optical losses and a more rapid recovery of transparency. A model of two photon fluxes is proposed to analyze the relationship of the effects of suppression of radiation-induced luminescence and the increase in optical losses upon light probing. The effect of suppression of radiation-induced luminescence can be used to control the optical properties of fibers in radiation fields.

  14. Radiation-induced endometriosis in Macaca mulatta

    SciTech Connect

    Fanton, J.W.; Golden, J.G. )

    1991-05-01

    Female rhesus monkeys received whole-body doses of ionizing radiation in the form of single-energy protons, mixed-energy protons, X rays, and electrons. Endometriosis developed in 53% of the monkeys during a 17-year period after exposure. Incidence rates for endometriosis related to radiation type were: single-energy protons, 54%; mixed-energy protons, 73%; X rays, 71%; and electrons, 57%. The incidence of endometriosis in nonirradiated control monkeys was 26%. Monkeys exposed to single-energy protons, mixed-energy protons, and X rays developed endometriosis at a significantly higher rate than control monkeys (chi 2, P less than 0.05). Severity of endometriosis was staged as massive, moderate, and minimal. The incidence of these stages were 65, 16, and 19%, respectively. Observations of clinical disease included weight loss in 43% of the monkeys, anorexia in 35%, space-occupying masses detected by abdominal palpation in 55%, abnormal ovarian/uterine anatomy on rectal examination in 89%, and radiographic evidence of abdominal masses in 38%. Pathological lesions were endometrial cyst formation in 69% of the monkeys, adhesions of the colon in 66%, urinary bladder in 50%, ovaries in 86%, and ureters in 44%, focal nodules of endometrial tissue throughout the omentum in 59%, and metastasis in 9%. Clinical management of endometriosis consisted of debulking surgery and bilateral salpingo-oophorectomy combined in some cases with total abdominal hysterectomy. Postoperative survival rates at 1 and 5 years for monkeys recovering from surgery were 48 and 36%, respectively.

  15. The influence of infrared radiation on short-term ultraviolet-radiation-induced injuries

    SciTech Connect

    Kaidbey, K.H.; Witkowski, T.A.; Kligman, A.M.

    1982-05-01

    Because heat has been reported to influence adversely short- and long-term ultraviolet (UV)-radiation-induced skin damage in animals, we investigated the short-term effects of infrared radiation on sunburn and on phototoxic reactions to topical methoxsalen and anthracene in human volunteers. Prior heating of the skin caused suppression of the phototoxic response to methoxsalen as evidenced by an increase in the threshold erythema dose. Heat administered either before or after exposure to UV radiation had no detectable influence on sunburn erythema or on phototoxic reactions provoked by anthracene.

  16. Panretinal photocoagulation for radiation-induced ocular ischemia

    SciTech Connect

    Augsburger, J.J.; Roth, S.E.; Magargal, L.E.; Shields, J.A.

    1987-08-01

    We present preliminary findings on the effectiveness of panretinal photocoagulation in preventing neovascular glaucoma in eyes with radiation-induced ocular ischemia. Our study group consisted of 20 patients who developed radiation-induced ocular ischemia following cobalt-60 plaque radiotherapy for a choroidal or ciliary body melanoma. Eleven of the 20 patients were treated by panretinal photocoagulation shortly after the diagnosis of ocular ischemia, but nine patients were left untreated. In this non-randomized study, the rate of development of neovascular glaucoma was significantly lower (p = 0.024) for the 11 photocoagulated patients than for the nine who were left untreated.

  17. The Mechanisms of Radiation-Induced Bystander Effect

    PubMed Central

    Najafi, M; Fardid, R; Hadadi, Gh; Fardid, M

    2014-01-01

    The radiation-induced bystander effect is the phenomenon which non-irradiated cells exhibit effects along with their different levels as a result of signals received from nearby irradiated cells. Responses of non-irradiated cells may include changes in process of translation, gene expression, cell proliferation, apoptosis and cells death. These changes are confirmed by results of some In-Vivo studies. Most well-known important factors affecting radiation-induced bystander effect include free radicals, immune system factors, expression changes of some genes involved in inflammation pathway and epigenetic factors. PMID:25599062

  18. Intraoperative radiation therapy-induced sarcomas in dogs

    SciTech Connect

    Hoekstra, H.J.; Sindelar, W.F.; Kinsella, T.J.; Mehta, D.M. )

    1989-12-01

    In a canine model the tolerance of normal and surgically manipulated tissue to intraoperative radiotherapy (IORT) was investigated to provide guidelines for the clinical use of IORT in human cancer patients. A dose of 20 Gy IORT, with or without external beam radiotherapy, was generally well tolerated without significant increased treatment morbidity. Higher doses of IORT (over 30 Gy) have produced radiation-induced sarcomas in some animals followed over a long period. Therefore IORT should be used only in human cancer patients in well controlled studies, in which complications are well documented, and the possibility of radiation-induced malignancies in long-term survival should be considered.

  19. [Symptoms, diagnosis and treatment of radiation-induced enteritis].

    PubMed

    Sinkó, Dániel; Baranyai, Zsolt; Nemeskéri, Csaba; Teknos, Dániel; Jósa, Valéria; Hegedus, László; Mayer, Arpád

    2010-09-05

    The number of radiotherapy in the treatment of malignant diseases is increasing worldwide. During the radiotherapy of tumors in the minor pelvis and abdomen intestinal inflammation of different degree may occur even if special attention is paid. Irradiation to the minor pelvis causes in half of the cases radiation induced acute enteritis, whereas in 25% chronic enteritis and colitis will develop. Chronic enteritis following radiotherapy raises a number of diagnostic and therapeutic problems that can be solved only with cooperation of different specialties. Authors present a short review regarding therapeutical options of radiation induced enteritis.

  20. Radiation-induced genomic instability and its implications for radiation carcinogenesis

    NASA Technical Reports Server (NTRS)

    Huang, Lei; Snyder, Andrew R.; Morgan, William F.

    2003-01-01

    Radiation-induced genomic instability is characterized by an increased rate of genetic alterations including cytogenetic rearrangements, mutations, gene amplifications, transformation and cell death in the progeny of irradiated cells multiple generations after the initial insult. Chromosomal rearrangements are the best-characterized end point of radiation-induced genomic instability, and many of the rearrangements described are similar to those found in human cancers. Chromosome breakage syndromes are defined by chromosome instability, and individuals with these diseases are cancer prone. Consequently, chromosomal instability as a phenotype may underlie some fraction of those changes leading to cancer. Here we attempt to relate current knowledge regarding radiation-induced chromosome instability with the emerging molecular information on the chromosome breakage syndromes. The goal is to understand how genetic and epigenetic factors might influence the onset of chromosome instability and the role of chromosomal instability in carcinogenesis.

  1. Radiation-induced genomic instability and its implications for radiation carcinogenesis

    NASA Technical Reports Server (NTRS)

    Huang, Lei; Snyder, Andrew R.; Morgan, William F.

    2003-01-01

    Radiation-induced genomic instability is characterized by an increased rate of genetic alterations including cytogenetic rearrangements, mutations, gene amplifications, transformation and cell death in the progeny of irradiated cells multiple generations after the initial insult. Chromosomal rearrangements are the best-characterized end point of radiation-induced genomic instability, and many of the rearrangements described are similar to those found in human cancers. Chromosome breakage syndromes are defined by chromosome instability, and individuals with these diseases are cancer prone. Consequently, chromosomal instability as a phenotype may underlie some fraction of those changes leading to cancer. Here we attempt to relate current knowledge regarding radiation-induced chromosome instability with the emerging molecular information on the chromosome breakage syndromes. The goal is to understand how genetic and epigenetic factors might influence the onset of chromosome instability and the role of chromosomal instability in carcinogenesis.

  2. Ionizing radiation-induced mutagenesis: radiation studies in Neurospora predictive for results in mammalian cells

    NASA Technical Reports Server (NTRS)

    Evans, H. H.; DeMarini, D. M.

    1999-01-01

    Ionizing radiation was the first mutagen discovered and was used to develop the first mutagenicity assay. In the ensuing 70+ years, ionizing radiation became a fundamental tool in understanding mutagenesis and is still a subject of intensive research. Frederick de Serres et al. developed and used the Neurospora crassa ad-3 system initially to explore the mutagenic effects of ionizing radiation. Using this system, de Serres et al. demonstrated the dependence of the frequency and spectra of mutations induced by ionizing radiation on the dose, dose rate, radiation quality, repair capabilities of the cells, and the target gene employed. This work in Neurospora predicted the subsequent observations of the mutagenic effects of ionizing radiation in mammalian cells. Modeled originally on the mouse specific-locus system developed by William L. Russell, the N. crassa ad-3 system developed by de Serres has itself served as a model for interpreting the results in subsequent systems in mammalian cells. This review describes the primary findings on the nature of ionizing radiation-induced mutagenesis in the N. crassa ad-3 system and the parallel observations made years later in mammalian cells.

  3. Ionizing radiation-induced mutagenesis: radiation studies in Neurospora predictive for results in mammalian cells

    NASA Technical Reports Server (NTRS)

    Evans, H. H.; DeMarini, D. M.

    1999-01-01

    Ionizing radiation was the first mutagen discovered and was used to develop the first mutagenicity assay. In the ensuing 70+ years, ionizing radiation became a fundamental tool in understanding mutagenesis and is still a subject of intensive research. Frederick de Serres et al. developed and used the Neurospora crassa ad-3 system initially to explore the mutagenic effects of ionizing radiation. Using this system, de Serres et al. demonstrated the dependence of the frequency and spectra of mutations induced by ionizing radiation on the dose, dose rate, radiation quality, repair capabilities of the cells, and the target gene employed. This work in Neurospora predicted the subsequent observations of the mutagenic effects of ionizing radiation in mammalian cells. Modeled originally on the mouse specific-locus system developed by William L. Russell, the N. crassa ad-3 system developed by de Serres has itself served as a model for interpreting the results in subsequent systems in mammalian cells. This review describes the primary findings on the nature of ionizing radiation-induced mutagenesis in the N. crassa ad-3 system and the parallel observations made years later in mammalian cells.

  4. Modulation of Radiation-Induced Apoptosis by Thiolamines

    NASA Technical Reports Server (NTRS)

    Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

    1997-01-01

    Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

  5. Modulation of Radiation-Induced Apoptosis by Thiolamines

    NASA Technical Reports Server (NTRS)

    Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

    1997-01-01

    Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

  6. Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.

    NASA Astrophysics Data System (ADS)

    Matsumoto, H.; Ohnishi, T.

    There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

  7. Atorvastatin Ameliorates Radiation-Induced Cardiac Fibrosis in Rats.

    PubMed

    Zhang, KunYi; He, XuYu; Zhou, Yingling; Gao, Lijuan; Qi, Zhengyu; Chen, Jiyan; Gao, Xiuren

    2015-12-01

    Radiation-induced heart injury is one of the major side effects of radiotherapy for thoracic malignancies. Previous studies have shown that radiotherapy induced myocardial fibrosis and intensified myocardial remodeling. In this study, we investigated whether atorvastatin could inhibit radiation-induced heart fibrosis in Sprague-Dawley rats, which were randomly divided into six groups: control; radiation only; and four treatment groups receiving atorvastatin plus radiation (E1, E2, E3 and E4). All rats, except the control group, received local heart irradiation in 7 daily fractions of 3 Gy for a total of 21 Gy. Rats in groups E1 (10 mg/kg/day) and E2 (20 mg/kg/day) received atorvastatin and radiation treatment until week 12 after exposure. Rats in groups E3 (10 mg/kg/day) and E4 (20 mg/kg/day) received atorvastatin treatment from 3 months before irradiation to week 12 after irradiation. The expressions of TGF-β1, Smad2, Smad3, fibronectin, ROCK I and p-Akt in heart tissues were evaluated using real-time PCR or Western blot analyses. Atorvastatin significantly reduced the expression of TGF-β1, Smad3/P-Smad3, ROCK I and p-Akt in rats of the E1-E4 groups and in a dose-dependent manner. Fibronectin exhibited a similar pattern of expression changes. In addition, echocardiography showed that atorvastatin treatment can inhibit the increase of left ventricular end-diastolic dimension, left ventricular end-systolic diameter and left ventricular posterior wall thickness, and prevent the decrease of ejection fraction and fraction shortening in E1-E4 groups compared with the radiation only group. This study demonstrated that radiation exposure increased the expression of fibronectin in cardiac fibroblasts and induced cardiac fibrosis through activation of the TGF-β1/Smad3, RhoA/ROCK, and PI3K/AKT signaling pathways. Statins ameliorated radiation-induced cardiac fibrosis in Sprague-Dawley rats. Our results suggest that atorvastatin is effective for the treatment of radiation-induced

  8. Performance evaluation of solar water sterilization system

    SciTech Connect

    Saitoh, Takeo; El-Ghetany, H.H.

    1998-07-01

    In most countries, the contaminated water is the major cause of most of the water-born diseases. Solar energy can be used in this field because the inactivation of micro-organisms is done by the ultraviolet solar radiation. A pilot solar system for sterilizing the contaminated water is designed, constructed and tested. The experimental data showed good viability for using solar energy in the sterilization process. A mathematical model of the solar sterilizer is also presented. The governing equations are solved numerically using fourth-order Runge-Kutta method. The effects of environmental conditions (ambient temperature, wind speed and solar radiation) on the solar sterilizer performance are examined. It is found that the system is affected by the ambient temperature, wind speed, ultraviolet solar radiation intensity, level of contamination of water, quantity of water being exposed, contact area between the transparent water container in the solar sterilizer and absorber plate and system geometrical parameters. It is pointed that, for a partial cloud condition, low ambient temperature and high wind speed the thermal efficiency of the solar sterilizer was minimum.

  9. The axiverse induced dark radiation problem

    NASA Astrophysics Data System (ADS)

    Acharya, Bobby; Pongkitivanichkul, Chakrit

    2016-04-01

    The string/ M theory Axiverse — a plethora of very light Axion Like Particles (ALPs) with a vast range of masses — is arguably a generic prediction of string/ M theory. String/ M theory also tends to predict that the early Universe is dominated by moduli fields. When the heavy moduli decay, before nucleosynthesis, they produce dark radiation in the form of relativistic ALPs. Generically one estimates that the number of relativistic species grows with the number of axions in the Axiverse, in contradiction to the observations that N eff ≤ 4. We explain this problem in detail and suggest some possible solutions to it. The simplest solution requires that the lightest modulus decays only into its own axion superpartner plus Standard Model particles and this severely constrains the moduli Kahler potential and mass matrix.

  10. Human amniotic fluid stem cells have a potential to recover ovarian function in mice with chemotherapy-induced sterility

    PubMed Central

    2013-01-01

    Background Human amniotic fluid cells (hAFCs) may differentiate into multiple cell lineages and thus have a great potential to become a donor cell source for regenerative medicine. The ability of hAFCs to differentiate into germ cell and oocyte-like cells has been previously documented. Herein we report the potential use of hAFCs to help restore follicles in clinical condition involving premature ovarian failure. Results Human amniotic fluid was obtained via amniocentesis, yielding a subpopulation of cloned hAFCs that was able to form embryoid bodies (EBs) and differentiate into three embryonic germ layers. Moreover, culture of EBs in medium containing human follicular fluid (HFF) or a germ cell maturation factor cocktail (FAC), expressed germ cells markers such as BLIMP1, STELLA, DAZL, VASA, STRA8, SCP3, SCP1, and GDF9. Furthermore, one cell line was grown from clone cells transfected with lentivirus-GFP and displaying morphological characteristics of mesenchymal cells, had the ability to restore ovarian morphology following cell injection into the ovaries of mice sterilized by intraperitoneal injection of cyclophosphamide and busulphan. Restored ovaries displayed many follicle-enclosed oocytes at all stages of development, but no oocytes or follicles were observed in sterilized mice whose ovaries had been injected with medium only (control). Notably, identification of GFP-labeled cells and immunostaining with anti–human antigen-specific antibodies demonstrated that grafted hAFCs survived and differentiated into granulosa cells which directed oocyte maturation. Furthermore, labeling of ovarian tissue for anti-Müllerian hormone expression, a functional marker of folliculogenesis, was strong in hAFCs-transplanted ovaries but inexistent in negative controls. Conclusion These findings highlight the possibility of using human amniotic fluid-derived stem cells in regenerative medicine, in particular in the area of reproductive health. PMID:24006896

  11. Radiation-induced cardiomyopathy as a function of radiation beam gating to the cardiac cycle

    NASA Astrophysics Data System (ADS)

    Gladstone, David J.; Flanagan, Michael F.; Southworth, Jean B.; Hadley, Vaughn; Thibualt, Melissa Wei; Hug, Eugen B.; Hoopes, P. Jack

    2004-04-01

    Portions of the heart are often unavoidably included in the primary treatment volume during thoracic radiotherapy, and radiation-induced heart disease has been observed as a treatment-related complication. Such complications have been observed in humans following radiation therapy for Hodgkin's disease and treatment of the left breast for carcinoma. Recent attempts have been made to prevent re-stenosis following angioplasty procedures using external beam irradiation. These attempts were not successful, however, due to the large volume of heart included in the treatment field and subsequent cardiac morbidity. We suggest a mechanism for sparing the heart from radiation damage by synchronizing the radiation beam with the cardiac cycle and delivering radiation only when the heart is in a relatively hypoxic state. We present data from a rat model testing this hypothesis and show that radiation damage to the heart can be altered by synchronizing the radiation beam with the cardiac cycle. This technique may be useful in reducing radiation damage to the heart secondary to treatment for diseases such as Hodgkin's disease and breast cancer.

  12. Radiation-induced dural fibrosarcoma with unusually short latent period

    SciTech Connect

    Ghatak, N.R.; Aydin, F.; Leshner, R.T. Tulane Univ., New Orleans, LA )

    1993-05-01

    Although rare, the occurrence of radiation-induced intracranial neoplasms of various types is well known. Among these tumors, fibrosarcomas, especially in the region of seila turcica, seem to be the most common type. These tumors characteristically occur after a long latent period, usually several years, following radiation therapy. The authors now report a case of apparently radiation-induced fibrosarcoma with some unusual features in a 10-year-old boy who was treated with radiation for medulloblastoma. He received a total dose of 53.2 Gy radiation delivered at 1.8 per fraction with 6 MV acceleration using the standard craniospinal technique. An MRI at 15 months after the completion of radiotherapy showed a mass over the cerebral convexity, which increased two-fold in size within a period of 4 months. A well circumscribed tumor was removed from the fronto-parietal convexity. The tumor measured 5x4.5x1.5 cm and was attached to the dura with invasion of the overlying bone. Histologically, it displayed the characteristic features of a low-grade fibrosarcoma. The patient remains free of tumor 18 months after the surgery. This case emphasizes the potential risk for the development of a second neoplasm following therapeutic radiation and also documents, to the authors' knowledge, the shortest latent period reported so far between administration of radiotherapy and development of an intracranial tumor.

  13. Radiation-Induced Bystander Response: Mechanism and Clinical Implications

    PubMed Central

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    Significance: Absorption of energy from ionizing radiation (IR) to the genetic material in the cell gives rise to damage to DNA in a dose-dependent manner. There are two types of DNA damage; by a high dose (causing acute or deterministic effects) and by a low dose (related to chronic or stochastic effects), both of which induce different health effects. Among radiation effects, acute cutaneous radiation syndrome results from cell killing as a consequence of high-dose exposure. Recent advances: Recent advances in radiation biology and oncology have demonstrated that bystander effects, which are emerged in cells that have never been exposed, but neighboring irradiated cells, are also involved in radiation effects. Bystander effects are now recognized as an indispensable component of tissue response related to deleterious effects of IR. Critical issues: Evidence has indicated that nonapoptotic premature senescence is commonly observed in various tissues and organs. Senesced cells were found to secrete various proteins, including cytokines, chemokines, and growth factors, most of which are equivalent to those identified as bystander factors. Secreted factors could trigger cell proliferation, angiogenesis, cell migration, inflammatory response, etc., which provide a tissue microenvironment assisting tissue repair and remodeling. Future directions: Understandings of the mechanisms and physiological relevance of radiation-induced bystander effects are quite essential for the beneficial control of wound healing and care. Further studies should extend our knowledge of the mechanisms of bystander effects and mode of cell death in response to IR. PMID:24761341

  14. Radiation-induced conductivity control in polyaniline blends/composites

    NASA Astrophysics Data System (ADS)

    Güven, Olgun

    2007-08-01

    Polyaniline (PANI) blends with chlorine-containing polymers and copolymers and composites with HCl-releasing compounds were prepared to investigate their radiation response in terms of induced conductivities. Blends of non-conductive PANI with poly(vinyl chloride) (PVC), poly(vinylidene chloride- co-vinyl acetate), [P(VDC- co-VAc)], poly(vinylidene chloride- co-vinyl chloride), [P(VDC- co-VC)] were prepared in the form of as-cast films. A number of blends which are different in composition were exposed to gamma radiation and accelerated electrons to various doses, and the effects of irradiation type and composition of polymers on the conductivity of films were investigated by using conductivity measurements and UV-vis and FT-IR spectroscopy. The results clearly showed that ionizing radiation is an effective tool to induce and control conductivity in the blends of PANI-base with chlorine-carrying polymers as well as its composites prepared from HCl-releasing compounds such as chloral hydrate. The main mechanism behind this radiation-induced conductivity is in situ doping of PANI-base with HCl released from partner polymers and low molecular weight compounds by the effect of radiation.

  15. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice.

    PubMed

    Lee, Seung Jun; Yi, Chin-ok; Heo, Rok Won; Song, Dae Hyun; Cho, Yu Ji; Jeong, Yi Yeong; Kang, Ki Mun; Roh, Gu Seob; Lee, Jong Deog

    2015-01-01

    Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-α, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-β1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis.

  16. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice

    PubMed Central

    Lee, Seung Jun; Yi, Chin-ok; Heo, Rok Won; Song, Dae Hyun; Cho, Yu Ji; Jeong, Yi Yeong; Kang, Ki Mun; Roh, Gu Seob; Lee, Jong Deog

    2015-01-01

    Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-α, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-β1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis. PMID:26114656

  17. Stimulation of respiration in rat thymocytes induced by ionizing radiation.

    PubMed

    Gudz, T I; Pandelova, I G; Novgorodov, S A

    1994-04-01

    The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La3+ and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation.

  18. Dynamics of radiation-induced amorphization in intermetallic compounds

    SciTech Connect

    Lam, N.Q.; Okamoto, P.R. ); Devanathan, R. Northwestern Univ., Evanston, IL . Dept. of Materials Science and Engineering); Meshii, M. . Dept. of Materials Science and Engineering)

    1992-06-01

    Recent progress in molecular-dynamics simulations of radiation-induced crystalline-to-amorphous transition in intermetallic compounds and the relationship between amorphization and melting are discussed. By focusing on the mean-square static displacement, which provides a generic measure of energy stored in the lattice in the forms of chemical and topological disorder, a unified description of solid-state amorphization as a disorder-induced, isothermal melting process can be developed within the framework of a generalized Lindemann criterion.

  19. Interleukin-32 Positively Regulates Radiation-Induced Vascular Inflammation

    SciTech Connect

    Kobayashi, Hanako; Yazlovitskaya, Eugenia M.; Lin, P. Charles

    2009-08-01

    Purpose: To study the role of interleukin-32 (IL-32), a novel protein only detected in human tissues, in ionizing radiation (IR)-induced vascular inflammation. Methods and Materials: Irradiated (0-6 Gy) human umbilical vein endothelial cells treated with or without various agents-a cytosolic phospholipase A2 (cPLA2) inhibitor, a cyclooxygenase-2 (Cox-2) inhibitor, or lysophosphatidylcholines (LPCs)-were used to assess IL-32 expression by Northern blot analysis and quantitative reverse transcriptase-polymerase chain reaction. Expression of cell adhesion molecules and leukocyte adhesion to endothelial cells using human acute monocytic leukemia cell line (THP-1) cells was also analyzed. Results: Ionizing radiation dramatically increased IL-32 expression in vascular endothelial cells through multiple pathways. Ionizing radiation induced IL-32 expression through nuclear factor {kappa}B activation, through induction of cPLA2 and LPC, as well as induction of Cox-2 and subsequent conversion of arachidonic acid to prostacyclin. Conversely, blocking nuclear factor {kappa}B, cPLA2, and Cox-2 activity impaired IR-induced IL-32 expression. Importantly, IL-32 significantly enhanced IR-induced expression of vascular cell adhesion molecules and leukocyte adhesion on endothelial cells. Conclusion: This study identifies IL-32 as a positive regulator in IR-induced vascular inflammation, and neutralization of IL-32 may be beneficial in protecting from IR-induced inflammation.

  20. Radiation-induced DNA damage and chromatin structure

    NASA Technical Reports Server (NTRS)

    Rydberg, B.; Chatterjee, A. (Principal Investigator)

    2001-01-01

    DNA lesions induced by ionizing radiation in cells are clustered and not randomly distributed. For low linear energy transfer (LET) radiation this clustering occurs mainly on the small scales of DNA molecules and nucleosomes. For example, experimental evidence suggests that both strands of DNA on the nucleosomal surface can be damaged in single events and that this damage occurs with a 10-bp modulation because of protection by histones. For high LET radiation, clustering also occurs on a larger scale and depends on chromatin organization. A particularly significant clustering occurs when an ionizing particle traverses the 30 nm chromatin fiber with generation of heavily damaged DNA regions with an average size of about 2 kbp. On an even larger scale, high LET radiation can produce several DNA double-strand breaks in closer proximity than expected from randomness. It is suggested that this increases the probability of misrejoining of DNA ends and generation of lethal chromosome aberrations.

  1. Factors that modify risks of radiation-induced cancer

    SciTech Connect

    Fabrikant, J.I.

    1988-11-01

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors).

  2. Radiation Induced Cystitis and Proctitis - Prediction, Assessment and Management.

    PubMed

    Mallick, Supriya; Madan, Renu; Julka, Pramod K; Rath, Goura K

    2015-01-01

    Cystitis and proctitis are defined as inflammation of bladder and rectum respectively. Haemorrhagic cystitis is the most severe clinical manifestation of radiation and chemical cystitis. Radiation proctitis and cystitis are major complications following radiotherapy. Prevention of radiation-induced haemorrhagic cystitis has been investigated using various oral agents with minimal benefit. Bladder irrigation remains the most frequently adopted modality followed by intra-vesical instillation of alum or formalin. In intractable cases, surgical intervention is required in the form of diversion ureterostomy or cystectomy. Proctitis is more common in even low dose ranges but is self-limiting and improves on treatment interruption. However, treatment of radiation proctitis is broadly non-invasive or invasive. Non-invasive treatment consists of non-steroid anti-inflammatory drugs (NSAIDs), anti-oxidants, sucralfate, short chain fatty acids and hyperbaric oxygen. Invasive treatment consists of ablative procedures like formalin application, endoscopic YAG laser coagulation or argon plasma coagulation and surgery as a last resort.

  3. The Dose Window for Radiation-Induced Protective Adaptive Responses

    PubMed Central

    Mitchel, Ronald E. J.

    2009-01-01

    Adaptive responses to low doses of low LET radiation occur in all organisms thus far examined, from single cell lower eukaryotes to mammals. These responses reduce the deleterious consequences of DNA damaging events, including radiation-induced or spontaneous cancer and non-cancer diseases in mice. The adaptive response in mammalian cells and mammals operates within a certain window that can be defined by upper and lower dose thresholds, typically between about 1 and 100 mGy for a single low dose rate exposure. However, these thresholds for protection are not a fixed function of total dose, but also vary with dose rate, additional radiation or non-radiation stressors, tissue type and p53 functional status. Exposures above the upper threshold are generally detrimental, while exposures below the lower threshold may or may not increase either cancer or non-cancer disease risk. PMID:20585438

  4. Radiation-induced DNA damage and chromatin structure

    NASA Technical Reports Server (NTRS)

    Rydberg, B.; Chatterjee, A. (Principal Investigator)

    2001-01-01

    DNA lesions induced by ionizing radiation in cells are clustered and not randomly distributed. For low linear energy transfer (LET) radiation this clustering occurs mainly on the small scales of DNA molecules and nucleosomes. For example, experimental evidence suggests that both strands of DNA on the nucleosomal surface can be damaged in single events and that this damage occurs with a 10-bp modulation because of protection by histones. For high LET radiation, clustering also occurs on a larger scale and depends on chromatin organization. A particularly significant clustering occurs when an ionizing particle traverses the 30 nm chromatin fiber with generation of heavily damaged DNA regions with an average size of about 2 kbp. On an even larger scale, high LET radiation can produce several DNA double-strand breaks in closer proximity than expected from randomness. It is suggested that this increases the probability of misrejoining of DNA ends and generation of lethal chromosome aberrations.

  5. Pulsed radiation-induced attenuation in certain optical fibers

    SciTech Connect

    Weiss, J.D. )

    1992-05-01

    Using the X-ray pulse from the HERMES II simulation machine at Sandia National Laboratories, the pulsed radiation-induced attenuation was measured in two optical fibers considered to be 'nonrad-hard': the 50-micron-core, graded-index fiber from Corning and the plastic (PMMA) fiber from the Mitsubishi Rayon Company. These fibers were exposed to radiation up to doses of 19.5 and 28 krad(Si), respectively. In addition, fits of their post-radiation recovery were made to the geminate recombination model, from which the recombination-rate and generation constants, characteristic of this theory, were determined. These parameters should be useful in determining the response of the fibers to radiation conditions other than those encountered here. 18 refs.

  6. Radiation-induced mutagenicity and lethality in Salmonella typhimurium

    SciTech Connect

    Isildar, M.; Bakale, G.

    1983-01-01

    The mutagenic and lethal effects of ionizing radiation on histidine-deficient auxotrophs of Salmonella typhimurium were studied to improve the understanding of radiation damage to DNA. The auxotrophs were divided into two groups - one which is sensitive to base-pair substitutions and another sensitive to frameshifts. These groups were composed of parent-daughter pairs in which the chemical mutagenicity enhancing plasmid, pKM101, is absent in the parent strain and present in the daughter. Co-60 ..gamma..-radiation and 250 kV x-rays were used to irradiate the bacteria. Irradiation of the frameshift - sensitive strains which carry the pKm101 plasmid doubled the absolute number of induced revertants whereas irradiation of the base-pair substitution sensitive strain which also carries the pKm101 plasmid produced nearly no change in the number of induced revertants. A nearly negligible effect on the mutation rate was observed for all parent strains. (ACR)

  7. Radiation-induced decomposition of explosives under extreme conditions

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael; Yang, Wenge; Liermann, Peter

    2008-11-03

    We present high-pressure and high temperature studies of the synchrotron radiation-induced decomposition of powder secondary high explosives pentaerythritol tetranitrate (PETN) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) using white beam synchrotron radiation at the 16 BM-B and 16 BM-D sectors of the HP-CAT beamline at the Advanced Photon Source. The radiation-induced decomposition rate TATB showed dramatic slowing with pressure up to 26.6 GPa (the highest pressure studied), implying a positive activation volume of the activated complex. The decomposition rate of PETN varied little with pressure up to 15.7 GPa (the highest pressure studied). Diffraction line intensities were measured as a function of time using energy-dispersive methods. By measuring the decomposition rate as a function of pressure and temperature, kinetic and other constants associated with the decomposition reactions were extracted.

  8. Radioadaptive response for protection against radiation-induced teratogenesis.

    PubMed

    Okazaki, Ryuji; Ootsuyama, Akira; Norimura, Toshiyuki

    2005-03-01

    To clarify the characteristics of the radioadaptive response in mice, we compared the incidence of radiation-induced malformations in ICR mice. Pregnant ICR mice were exposed to a priming dose of 2 cGy (667 muGy/min) on day 9.5 of gestation and to a challenging dose of 2 Gy (1.04 Gy/min) 4 h later and were killed on day 18.5 of gestation. The incidence of malformations and prenatal death and fetal body weights were studied. The incidence of external malformations was significantly lower (by approximately 10%) in the primed (2 cGy + 2 Gy) mice compared to the unprimed (2 Gy alone) mice. However, there were no differences in the incidence of prenatal death or the skeletal malformations or the body weights between primed and unprimed mice. These results suggest that primary conditioning with low doses of radiation suppresses radiation-induced teratogenesis.

  9. Modulation of radiation-induced hemopoietic suppression by acute thrombocytopenia

    SciTech Connect

    Ebbe, S.; Phalen, E.; Threatte, G.; Londe, H.

    1985-01-01

    Modifications of radiation-induced hemopoietic suppression by acute thrombocytopenia were evaluated. Immediately before or after exposure to sublethal irradiation, mice were given a single injection of anti-mouse platelet serum (APS), normal heterologous serum, neuraminidase (N'ase), or saline, or no further treatment was provided. Hemopoiesis was evaluated by blood cell counts, hematocrits, and incorporation of (75Se)selenomethionine into platelets. APS and N'ase induced an acute thrombocytopenia from which there was partial recovery before the platelet count started to fall from the radiation. During the second post-treatment week, both thrombocytopoiesis and erythropoiesis were greater in mice that received APS or N'ase in addition to radiation than in control irradiated mice. Differences in leukopoiesis were not apparent. Therefore, both thrombocytopoiesis and erythropoiesis appeared to be responsive to a stimulus generated by acute thrombocytopenia in sublethally irradiated mice.

  10. Radiation-induced transient darkening of optically transparent polymers

    SciTech Connect

    Downey, S.W.; Builta, L.A.; Carlson, R.L.; Czuchlewski, S.J.; Moir, D.C.

    1986-11-15

    Results are presented for the radiation-induced transient darkening of thin organic polymer films normally used as Cerenkov light emissions sources. The radiation source is a 27-MeV, 10-..mu..C, 200-ns electron beam generated by the PHERMEX accelerator. The typical dose for a single pulse is 5 Mrad. At this dose, the broadband time-resolved percent transmission above 520 nm was measured for four common polymers: polyimide (Kapton-H), polyethylene terephthalate (Mylar), cellulose acetate, and high-density polyethylene. Kapton was found to darken the most and polyethylene darkened the least. The recovery time to normal transmission for Kapton was found to be greater than 10--20 ..mu..s. The radiation-induced attenuation coefficient is shown to depend on electronic band energy separation. The results show that Kapton is not the material of choice for a Cerenkov light source.

  11. Mechanisms of radiation-induced gene responses

    SciTech Connect

    Woloschak, G.E.; Paunesku, T.

    1996-10-01

    In the process of identifying genes differentially expressed in cells exposed ultraviolet radiation, we have identified a transcript having a 26-bp region that is highly conserved in a variety of species including Bacillus circulans, yeast, pumpkin, Drosophila, mouse, and man. When the 5` region (flanking region or UTR) of a gene, the sequence is predominantly in +/+ orientation with respect to the coding DNA strand; while in the coding region and the 3` region (UTR), the sequence is most frequently in the +/-orientation with respect to the coding DNA strand. In two genes, the element is split into two parts; however, in most cases, it is found only once but with a minimum of 11 consecutive nucleotides precisely depicting the original sequence. The element is found in a large number of different genes with diverse functions (from human ras p21 to B. circulans chitonase). Gel shift assays demonstrated the presence of a protein in HeLa cell extracts that binds to the sense and antisense single-stranded consensus oligomers, as well as to the double- stranded oligonucleotide. When double-stranded oligomer was used, the size shift demonstrated as additional protein-oligomer complex larger than the one bound to either sense or antisense single-stranded consensus oligomers alone. It is speculated either that this element binds to protein(s) important in maintaining DNA is a single-stranded orientation for transcription or, alternatively that this element is important in the transcription-coupled DNA repair process.

  12. Radiation-Induced Notch Signaling in Breast Cancer Stem Cells

    SciTech Connect

    Lagadec, Chann; Vlashi, Erina; Alhiyari, Yazeed; Phillips, Tiffany M.; Bochkur Dratver, Milana; Pajonk, Frank

    2013-11-01

    Purpose: To explore patterns of Notch receptor and ligand expression in response to radiation that could be crucial in defining optimal dosing schemes for γ-secretase inhibitors if combined with radiation. Methods and Materials: Using MCF-7 and T47D breast cancer cell lines, we used real-time reverse transcription–polymerase chain reaction to study the Notch pathway in response to radiation. Results: We show that Notch receptor and ligand expression during the first 48 hours after irradiation followed a complex radiation dose–dependent pattern and was most pronounced in mammospheres, enriched for breast cancer stem cells. Additionally, radiation activated the Notch pathway. Treatment with a γ-secretase inhibitor prevented radiation-induced Notch family gene expression and led to a significant reduction in the size of the breast cancer stem cell pool. Conclusions: Our results indicate that, if combined with radiation, γ-secretase inhibitors may prevent up-regulation of Notch receptor and ligand family members and thus reduce the number of surviving breast cancer stem cells.

  13. [Update - health risks induced by ionizing radiation from diagnostic imaging].

    PubMed

    Knüsli, Claudio; Walter, Martin

    2013-12-01

    Ionizing radiation is the most thoroughly investigated exogenous noxa. Since the early 20th century it is well known that using ionizing radiation in diagnostic procedures causes cancer - physicians themselves frequently being struck by this disease in those early days of radiology. Radiation protection therefore plays an important role. Below doses of 100 Millisievert (mSv) however much research has to be accomplished yet because not only malignant tumors, but cardiovascular diseases, malformations and genetic sequelae attributable to low dose radiation have been described. Unborns, children and adolescents are highly vulnerable. Dose response correlations are subject to continuing discussions because data stem mostly from calculations studying Japanese atomic bomb survivors. Radiation exposure is not exactly known, and it is unknown, if observations of radiation induced diseases in this ethnicity can be generalized. Nowadays the main source of low dose ionizing radiation from medical diagnostics is due to computertomography (CT). Large recent clinical studies from the UK and Australia investigating cancer incidence after exposition to CT in childhood and adolescence confirm that low doses in the range of 5 mSv already significantly increase the risk of malignant diseases during follow up. Imaging techniques as ultrasound and magnetic resonance tomography therefore should be preferred whenever appropriate.

  14. Poor outcome in radiation-induced constrictive pericarditis

    SciTech Connect

    Karram, T.; Rinkevitch, D.; Markiewicz, W. )

    1993-01-15

    The purpose was to compare the outcome of patients with radiation-induced constrictive pericarditis versus patients with constiction due to another etiology. Twenty patients with constrictive pericarditis were seen during 1975-1986 at a single medical center. Six had radiation-induced constrictive pericarditis (Group A). The etiology was idiopathic in ten subjects and secondary to carcinomatous encasement, chronic renal failure, purulent infection and tuberculosis in one patient each (Group B, N = 14). Meang age was 53.4 [+-] 15.5 years. Extensive pericardiectomy was performed in 3/6 Group A and 13/14 Group B patients. All Group A patients died, 4 weeks - 11 years post-diagnosis (median = 10 months). Two Group A patients died suddenly, one died post-operatively of respiratory failure, another of pneumonia and two of recurrent carcinoma. Thirteen Group B patients are alive (median follow-up = 72 months). The only death in this group was due to metastatic cancer. The poor outcome with radiation-induced constriction is probably multi-factorial. Poor surgical outcome is to be expected in patients with evidence of recurrent tumor, high-dose irradiation, pulmonary fibrosis or associated radiation-induced myocardinal, valvular or coronary damage.

  15. Radiation-induced augmentation of the immune response

    SciTech Connect

    Anderson, R.E.; Lefkovits, I.; Troup, G.M.

    1980-01-01

    Radiation-induced augmentation of the immune response has been shown to occur both in vivo and in vitro. Evidence is presented to implicate injury to an extremely radiosensitive T cell in the expression of this phenomenon. Experiments are outlined which could be employed to support or reflect this hypothesis.

  16. Radiation-induced xerostomia: pathophysiology, clinical course and supportive treatment.

    PubMed

    Guchelaar, H J; Vermes, A; Meerwaldt, J H

    1997-07-01

    Xerostomia, or oral dryness, is one of the most common complaints experienced by patients who have had radiotherapy of the oral cavity and neck region. The hallmarks of radiation-induced damage are acinar atrophy and chronic inflammation of the salivary glands. The early response, resulting in atrophy of the secretory cells without inflammation might be due to radiation-induced apoptosis. In contrast, the late response with inflammation could be a result of radiation-induced necrosis. The subjective complaint of a dry mouth appears to be poorly correlated with objective findings of salivary gland dysfunction. Xerostomia, with secondary symptoms of increased dental caries, difficulty in chewing, swallowing and speaking, and an increased incidence of oral candidiasis, can have a significant effect on the quality of life. At present there is no causal treatment for radiation-induced xerostomia. Temporary symptomatic relief can be offered by moistening agents and saliva substitutes, and is the only option for patients without residual salivary function. In patients with residual salivary function, oral administration of pilocarpine 5-10 mg three times a day is effective in increasing salivary flow and improving the symptoms of xerostomia, and this therapy should be considered as the treatment of choice. Effectiveness of sialogogue treatment requires residual salivary function, which emphasizes the potential benefit from sparing normal tissue during irradiation. The hypothesis concerning the existence of early apoptotic and late necrotic effects of irradiation on the salivary glands theoretically offers a way of achieving this goal.

  17. SPHINX Measurements of Radiation Induced Conductivity of Foam

    SciTech Connect

    Ballard, W.P.; Beutler, D.E.; Burt, M.; Dudley, K.J.; Stringer, T.A.

    1998-12-14

    Experiments on the SPHINX accelerator studying radiation-induced conductivity (RIC) in foam indicate that a field-exclusion boundary layer model better describes foam than a Maxwell-Garnett model that treats the conducting gas bubbles in the foam as modifying the dielectric constant. In both cases, wall attachment effects could be important but were neglected.

  18. Effect of sodium meclofenamate on ultraviolet radiation induced carcinogenesis

    SciTech Connect

    Ambrus, J.L.; Ambrus, C.M.; Pickren, J.W.; Klein, E.

    1984-01-01

    Sodium meclofenamate (Meclomen), an antiprostaglandin antileukotriene agent, was found in previous studies to protect primates against x-ray induced brain edema, esophagitis and cystitis. In the present study, it appeared to protect hairless mice against the carcinogenic effect of ultraviolet B-radiation.

  19. Radiation-Induced Immune Modulation in Prostate Cancer

    DTIC Science & Technology

    2007-01-01

    postulate that radiation-induced TNFR I probably acts as a “ brake ” on immunity. Because of the high risk of the proposed experiment and high...the rest of body shielded. Tumor diameters were measured in three mutually orthogonal dimensions at 2–3 day intervals with a vernier caliper and the

  20. Data acquisition system used in radiation induced electrical degradation experiments

    SciTech Connect

    White, D.P.

    1995-04-01

    Radiation induced electrical degradation (RIED) of ceramic materials has recently been reported and is the topic of much research at the present time. The object of this report is to describe the data acquisition system for an experiment designed to study RIED at the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory.

  1. Prevention of Radiation-Induced Breast Cancer by Amifostine

    DTIC Science & Technology

    2006-06-01

    acetylcysteine and captopril . 4 Task 2. To determine if post-irradiation amifostine treatment can reduce the frequency of radiation-induced ductal...similar to amifostine but more suited to oral administration such as WR- 3689, WR151327, N-acetylcysteine and captopril . The first task is to

  2. Prevention of Radiation-Induced Breast Cancer by Amifostine

    DTIC Science & Technology

    2009-01-01

    acetylcysteine and captopril . 4 Task 2. To determine if post-irradiation amifostine treatment can reduce the frequency of radiation-induced ductal...similar to amifostine but more suited to oral administration such as WR- 3689, WR151327, N-acetylcysteine and captopril . The first task is to

  3. Prevention of Radiation-Induced Breast Cancer by Amifostine

    DTIC Science & Technology

    2007-12-01

    and captopril . 4 Task 2. To determine if post-irradiation amifostine treatment can reduce the frequency of radiation-induced ductal dysplasia...amifostine but more suited to oral administration such as WR- 3689, WR151327, N-acetylcysteine and captopril . The first task is to determine if

  4. Caffeine ameliorates radiation-induced skin reactions in mice but does not influence tumour radiation response.

    PubMed

    Hebbar, S A; Mitra, A K; George, K C; Verma, N C

    2002-03-01

    Intramuscular administration of caffeine at a dose of 80 mg kg(-1) body weight to the gastrocnemius muscles of Swiss mice 5 min prior to local irradiation (35 Gy) of the leg delayed the progression of radiation-induced skin reactions in such animals. While 90% epilation with reddening of the skin was noted in animals treated with radiation alone, animals pretreated with caffeine suffered only partial hair loss with slight reddening of the skin on the 16th and 20th days post-irradiation. Beyond the 28th day, damage scores in irradiated feet for both the groups were similar (score 3) and remained unchanged until the 32nd day and then decreased and disappeared completely in both treatment groups by the 40th day after irradiation. In addition, the effect of caffeine on the radiation response of a mouse fibrosarcoma was investigated. Results showed that intratumoral administration of caffeine at a dose of 80 mg kg(-1) body weight 5 min prior to local exposure of tumours to 10 Gy of 60Co gamma-rays did not influence the response of tumours to radiation. The present study thus showed that although caffeine ameliorated radiation-induced skin reactions in the mouse leg, it did not affect the tumour radiation response, indicating its potential application in cancer radiotherapy.

  5. Sterilization of silicone-based hydrogels for biomedical application using ozone gas: Comparison with conventional techniques.

    PubMed

    Galante, Raquel; Ghisleni, Daniela; Paradiso, Patrizia; Alves, Vitor D; Pinto, Terezinha J A; Colaço, Rogério; Serro, Ana Paula

    2017-09-01

    Sterilization of hydrogels is challenging due to their often reported sensitivity to conventional methods involving heat or radiation. Although aseptic manufacturing is a possibility, terminal sterilization is safer in biological terms, leading to a higher overall efficiency, and thus should be used whenever it is possible. The main goal of this work was to study the applicability of an innovative ozone gas terminal sterilization method for silicone-based hydrogels and compare its efficacy and effects with those of traditional sterilization methods: steam heat and gamma irradiation. Ozone gas sterilization is a method with potential interest since it is reported as a low cost green method, does not leave toxic residues and can be applied to thermosensitive materials. A hydrogel intended for ophthalmological applications, based on tris(trimethylsiloxy)silyl] propyl methacrylate, was prepared and extensively characterized before and after the sterilization procedures. Alterations regarding transparency, swelling, wettability, ionic permeability, friction coefficient, mechanical properties, topography and morphology and chemical composition were monitored. Efficacy of the ozonation was accessed by performing controlled contaminations and sterility tests. In vitro cytotoxicity testes were also performed. The results show that ozonation may be applied to sterilize the studied material. A treatment with 8 pulses allowed sterilizing the material with bioburdens≤10(3)CFU/mL, preserving all the studied properties within the required known values for contact lenses materials. However, a higher exposure (10 pulses) led to some degradation of the material and induced mild cytotoxicity. Steam heat sterilization led to an increase of swelling capacity and a decrease of the water contact angle. Regarding gamma irradiation, the increase of irradiation dose led to an increase of the friction coefficient. The higher dose (25kGy) originated surface degradation and affected the

  6. Torin2 Suppresses Ionizing Radiation-Induced DNA Damage Repair.

    PubMed

    Udayakumar, Durga; Pandita, Raj K; Horikoshi, Nobuo; Liu, Yan; Liu, Qingsong; Wong, Kwok-Kin; Hunt, Clayton R; Gray, Nathanael S; Minna, John D; Pandita, Tej K; Westover, Kenneth D

    2016-05-01

    Several classes of inhibitors of the mammalian target of rapamycin (mTOR) have been developed based on its central role in sensing growth factor and nutrient levels to regulate cellular metabolism. However, its ATP-binding site closely resembles other phosphatidylinositol 3-kinase-related kinase (PIKK) family members, resulting in reactivity with these targets that may also be therapeutically useful. The ATP-competitive mTOR inhibitor, Torin2, shows biochemical activity against the DNA repair-associated proteins ATM, ATR and DNA-PK, which raises the possibility that Torin2 and related compounds might radiosensitize cancerous tumors. In this study Torin2 was also found to enhance ionizing radiation-induced cell killing in conditions where ATM was dispensable, confirming the requirement for multiple PIKK targets. Moreover, Torin2 did not influence the initial appearance of γ-H2AX foci after irradiation but significantly delayed the disappearance of radiation-induced γ-H2AX foci, indicating a DNA repair defect. Torin2 increased the number of radiation-induced S-phase specific chromosome aberrations and reduced the frequency of radiation-induced CtIP and Rad51 foci formation, suggesting that Torin2 works by blocking homologous recombination (HR)-mediated DNA repair resulting in an S-phase specific DNA repair defect. Accordingly, Torin2 reduced HR-mediated repair of I-Sce1-induced DNA damage and contributed to replication fork stalling. We conclude that radiosensitization of tumor cells by Torin2 is associated with disrupting ATR- and ATM-dependent DNA damage responses. Our findings support the concept of developing combination cancer therapies that incorporate ionizing radiation therapy and Torin2 or compounds with similar properties.

  7. Minimal role for the circumsporozoite protein in the induction of sterile immunity by vaccination with live rodent malaria sporozoites.

    PubMed

    Mauduit, Marjorie; Tewari, Rita; Depinay, Nadya; Kayibanda, Michèle; Lallemand, Eliette; Chavatte, Jean-Marc; Snounou, Georges; Rénia, Laurent; Grüner, Anne Charlotte

    2010-05-01

    Immunization with live Plasmodium sporozoites under chloroquine prophylaxis (Spz plus CQ) induces sterile immunity against sporozoite challenge in rodents and, more importantly, in humans. Full protection is obtained with substantially fewer parasites than with the classic immunization with radiation-attenuated sporozoites. The sterile protection observed comprised a massive reduction in the hepatic parasite load and an additional effect at the blood stage level. Differences in the immune responses induced by the two protocols occur but are as yet little characterized. We have previously demonstrated that in mice immunized with irradiated sporozoites, immune responses against the circumsporozoite protein (CSP), the major component of the sporozoite's surface and the leading malaria vaccine candidate, were not essential for sterile protection. Here, we have employed transgenic Plasmodium berghei parasites in which the endogenous CSP was replaced by that of Plasmodium yoelii, another rodent malaria species, to assess the role of CSP in the sterile protection induced by the Spz-plus-CQ protocol. The data demonstrated that this role was minor because sterile immunity was obtained irrespective of the origin of CSP expressed by the parasites in this model of protection. The immunity was obtained through a single transient exposure of the host to the immunizing parasites (preerythrocytic and erythrocytic), a dose much smaller than that required for immunization with radiation-attenuated sporozoites.

  8. Radiation-Induced Attenuation of Perfluorinated Polymer Optical Fibers for Radiation Monitoring.

    PubMed

    Stajanca, Pavol; Krebber, Katerina

    2017-08-25

    Due to some of their unique properties, optical fiber dosimeters are attractive and extensively researched devices in several radiation-related areas. This work evaluates the performance and potential of commercial perfluorinated polymer optical fibers (PF-POFs) for radiation monitoring applications. Gamma radiation-induced attenuation (RIA) of two commercial PF-POFs is evaluated in the VIS spectral region. Influence of a dose rate and temperature on RIA measurement is investigated, along with defect stability and measurement repeatability. Co-extruded PF-POFs are identified as more suitable for radiation monitoring applications due to lower dose-rate dependence. With co-extruded PF-POF, RIA measurement holds potential for highly-sensitive radiation monitoring with good reproducibility. The results show that operation in the blue part of the spectrum provides most favorable performance in terms of the largest nominal radiation sensitivity, lower temperature, and dose-rate dependence as well as higher defect stability. We demonstrate for the first time to our knowledge, that PF-POFs can be used for distributed detection of radiation with doses down to tens of Grays. The off-the-shelf, user-friendly PF-POF could be of interest as a cheap, disposable sensor for various applications, especially of a more qualitative nature.

  9. The radiation-induced changes in rectal mucosa: Hyperfractionated vs. hypofractionated preoperative radiation for rectal cancer

    SciTech Connect

    Starzewski, Jacek J.; Pajak, Jacek T.; Pawelczyk, Iwona; Lange, Dariusz; Golka, Dariusz . E-mail: dargolka@wp.pl; Brzeziska, Monika; Lorenc, Zbigniew

    2006-03-01

    Purpose: The purpose of the study was the qualitative and quantitative evaluation of acute radiation-induced rectal changes in patients who underwent preoperative radiotherapy according to two different irradiation protocols. Patients and Methods: Sixty-eight patients with rectal adenocarcinoma underwent preoperative radiotherapy; 44 and 24 patients underwent hyperfractionated and hypofractionated protocol, respectively. Fifteen patients treated with surgery alone served as a control group. Five basic histopathologic features (meganucleosis, inflammatory infiltrations, eosinophils, mucus secretion, and erosions) and two additional features (mitotic figures and architectural glandular abnormalities) of radiation-induced changes were qualified and quantified. Results: Acute radiation-induced reactions were found in 66 patients. The most common were eosinophilic and plasma-cell inflammatory infiltrations (65 patients), erosions, and decreased mucus secretion (54 patients). Meganucleosis and mitotic figures were more common in patients who underwent hyperfractionated radiotherapy. The least common were the glandular architectural distortions, especially in patients treated with hypofractionated radiotherapy. Statistically significant differences in morphologic parameters studied between groups treated with different irradiation protocols were found. Conclusion: The system of assessment is a valuable tool in the evaluation of radiation-induced changes in the rectal mucosa. A greater intensity of regenerative changes was found in patients treated with hyperfractionated radiotherapy.

  10. Sterilization of endoscopic instruments.

    PubMed

    Sabnis, Ravindra B; Bhattu, Amit; Vijaykumar, Mohankumar

    2014-03-01

    Sterilization of endoscopic instruments is an important but often ignored topic. The purpose of this article is to review the current literature on the sterilization of endoscopic instruments and elaborate on the appropriate sterilization practices. Autoclaving is an economic and excellent method of sterilizing the instruments that are not heat sensitive. Heat sensitive instruments may get damaged with hot sterilization methods. Several new endoscopic instruments such as flexible ureteroscopes, chip on tip endoscopes, are added in urologists armamentarium. Many of these instruments are heat sensitive and hence alternative efficacious methods of sterilization are necessary. Although ethylene oxide and hydrogen peroxide are excellent methods of sterilization, they have some drawbacks. Gamma irradiation is mainly for disposable items. Various chemical agents are widely used even though they achieve high-level disinfection rather than sterilization. This article reviews various methods of endoscopic instrument sterilization with their advantages and drawbacks. If appropriate sterilization methods are adopted, then it not only will protect patients from procedure-related infections but prevent hypersensitive allergic reactions. It will also protect instruments from damage and increase its longevity.

  11. Another look at sterilization.

    PubMed

    Willson, P D

    1977-03-01

    R.T. Ravenhol, Director of Office of Population at the U.S. Agency for International Development (AID), reports that voluntary sterilization is currently the foremost means of fertility control in the world. According to AID estimates, 65,000,000 couples had chosen voluntary sterilization by the end of 1975. In order to expand its support for voluntary sterilization, AID wants to offer more of its resources to services, equipment, biomedical research, physician training, and public education. The International Project of the Association for Voluntary Sterilization has been most active in the provision of voluntary sterilization. Funded by AID it has spent over $6 million on voluntary sterilization services, equipment, physician training, and conferences in over 50 countries since it was established in 1972. There is concern that the current acceptance of voluntary sterilization maybe jeopardized by lack of understanding about and sensitivity to sterilization's use. Voluntary and compulsory sterilization are at opposite ends of a spectrum, and for those involved in family planning in developing countries, there is the question of whether there is really massive demand for voluntary sterilization in developing countries and whether sterilization is truly voluntary. There has also been concern about voluntarism and informed consent in the U.S. domestic programs, and this has affected international projects. To stress the importance of voluntarism, AID contracts and grants, effective 1977, must include an extensive statement regarding voluntarism to ensure compliance with the court decision prohibiting federally funded sterilizations for minors and mental or legal incompetents. Additionally, AID contracts must require documented informed consent, and individuals choosing sterilizations need to receive a description of the risks and benefits as well as a statement that the procedure is irreversible.

  12. Radiation induced viscous flow in amorphous thin films

    NASA Astrophysics Data System (ADS)

    Mayr, S. G.; Ashkenazy, Y.; Averback, R. S.

    2003-03-01

    We investigate surface roughness and stress relaxation in amorphous thin films during ion beam irradiation by a combination of experiments and molecular dynamics simulations. These experiments show, that smoothing occurs by a viscous mechanism. With computer simulations we investigate the model system CuTi, and find that radiation induced viscous flow is independent of the recoil energy between 100 and 15keV, when compared on the basis of defect production. Additionally we can identify a threshold recoil energy for flow of approximately 10eV. We show, that point defects can mediate the flow, by injection of interstitial and vacancy-like defects, which induce the same amount of flow as recoil events. The results are compared with the thermal spike model of radiation induced viscous flow.

  13. Nature of radiation-induced defects in quartz

    SciTech Connect

    Wang, Bu; Yu, Yingtian; Bauchy, Mathieu; Pignatelli, Isabella; Sant, Gaurav

    2015-07-14

    Although quartz (α-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage has not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si–O connectivity defects, e.g., small Si–O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on E′ centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependence on the incident energy, of the amount of each type of the point defects formed, and quantify unambiguously the threshold displacement energies for both O and Si atoms. These results provide a comprehensive basis to assess the nature and extent of radiation damage in quartz.

  14. Radiation-induced skin carcinomas of the head and neck

    SciTech Connect

    Ron, E.; Modan, B.; Preston, D.; Alfandary, E.; Stovall, M.; Boice, J.D. Jr. )

    1991-03-01

    Radiation exposures to the scalp during childhood for tinea capitis were associated with a fourfold increase in skin cancer, primarily basal cell carcinomas, and a threefold increase in benign skin tumors. Malignant melanoma, however, was not significantly elevated. Overall, 80 neoplasms were identified from an extensive search of the pathology logs of all major hospitals in Israel and computer linkage with the national cancer registry. Radiation dose to the scalp was computed for over 10,000 persons irradiated for ringworm (mean 7 Gy), and incidence rates were contrasted with those observed in 16,000 matched comparison subjects. The relative risk of radiogenic skin cancer did not differ significantly between men or women or by time since exposure; however, risk was greatest following exposures in early childhood. After adjusting for sex, ethnic origin, and attained age, the estimated excess relative risk was 0.7 per Gy and the average excess risk over the current follow-up was 0.31/10(4) PY-Gy. The risk per Gy of radiation-induced skin cancer was intermediate between the high risk found among whites and no risk found among blacks in a similar study conducted in New York City. This finding suggests the role that subsequent exposure to uv radiation likely plays in the expression of a potential radiation-induced skin malignancy.

  15. Evidence for Radiation-Induced Disseminated Intravascular Coagulation as a Major Cause of Radiation-Induced Death in Ferrets

    PubMed Central

    Krigsfeld, Gabriel S.; Savage, Alexandria R.; Billings, Paul C.; Lin, Liyong; Kennedy, Ann R.

    2014-01-01

    Purpose/Objectives(s) The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events (SPEs), as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Methods and Materials Ferrets were exposed to 0 – 2 Gray (Gy) of whole body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. Results The lethal dose of radiation to 50% of the population, known as the LD50, of ferrets was established at ~ 1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 post-irradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early times post-irradiation when coagulopathies were present and progressively becoming more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Conclusions The data presented here provide evidence that death at the LD50 in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is solely due to the cell killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation induced death at relatively low doses in large mammals. PMID:24495588

  16. Evidence for radiation-induced disseminated intravascular coagulation as a major cause of radiation-induced death in ferrets.

    PubMed

    Krigsfeld, Gabriel S; Savage, Alexandria R; Billings, Paul C; Lin, Liyong; Kennedy, Ann R

    2014-03-15

    The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. The lethal dose of radiation to 50% of the population (LD50) of the ferrets was established at ∼ 1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Data presented here provide evidence that death at the LD50 in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Evidence for Radiation-Induced Disseminated Intravascular Coagulation as a Major Cause of Radiation-Induced Death in Ferrets

    SciTech Connect

    Krigsfeld, Gabriel S.; Savage, Alexandria R.; Billings, Paul C.; Lin, Liyong; Kennedy, Ann R.

    2014-03-15

    Purpose: The studies reported here were performed as part of a program in space radiation biology in which proton radiation like that present in solar particle events, as well as conventional gamma radiation, were being evaluated in terms of the ability to affect hemostasis. Methods and Materials: Ferrets were exposed to 0 to 2 Gy of whole-body proton or gamma radiation and monitored for 30 days. Blood was analyzed for blood cell counts, platelet clumping, thromboelastometry, and fibrin clot formation. Results: The lethal dose of radiation to 50% of the population (LD{sub 50}) of the ferrets was established at ∼1.5 Gy, with 100% mortality at 2 Gy. Hypocoagulability was present as early as day 7 postirradiation, with animals unable to generate a stable clot and exhibiting signs of platelet aggregation, thrombocytopenia, and fibrin clots in blood vessels of organs. Platelet counts were at normal levels during the early time points postirradiation when coagulopathies were present and becoming progressively more severe; platelet counts were greatly reduced at the time of the white blood cell nadir of 13 days. Conclusions: Data presented here provide evidence that death at the LD{sub 50} in ferrets is most likely due to disseminated intravascular coagulation (DIC). These data question the current hypothesis that death at relatively low doses of radiation is due solely to the cell-killing effects of hematopoietic cells. The recognition that radiation-induced DIC is the most likely mechanism of death in ferrets raises the question of whether DIC is a contributing mechanism to radiation-induced death at relatively low doses in large mammals.

  18. Characteristics of Surface Sterilization using ECR Plasma

    NASA Astrophysics Data System (ADS)

    Yonesu, Akira; Hara, Kazufumi; Nishikawa, Tatsuya; Hayashi, Nobuya

    2015-09-01

    Plasma sterilization techniques have superior characteristics such as a short treatment times, non-toxicity and low thermal damages on the sterilized materials. In plasma sterilization, microorganisms can be sterilized by active radicals, energetic charged particles, and vacuum UV radiation. The influence of each factor depends on the plasma operating parameters. Microwave discharges under the electron cyclotron resonance (ECR) condition produce higher electron temperature and density plasma as compared with other plasma generation techniques. In the present study, characteristics of surface sterilization using ECR plasma have been investigated.The experiment was performed in the vacuum chamber which contains a magnet holder. A pair of rectangular Sm-Co permanent magnets is aligned parallel to each other within the magnet holder. The region of the magnetic field for ECR exists near the magnet holder surface. When the microwave is introduced into the vacuum chamber, a ECR plasma is produced around surface of the magnet holder. High energy electrons and oxygen radicals were observed at ECR zone by electric probe method and optical spectroscopic method. Biological indicators (B.I.) having spore of 106 was sterilized in 2min for oxygen discharge. The temperature of the B.I. installation position was about 55°. The sterilization was achieved by the effect of oxygen radicals and high energy electrons.

  19. Intercellular Adhesion Molecule 1 Knockout Abrogates Radiation Induced Pulmonary Inflammation

    NASA Astrophysics Data System (ADS)

    Hallahan, Dennis E.; Virudachalam, Subbulakshmi

    1997-06-01

    Increased expression of intercellular adhesion molecule 1 (ICAM-1; CD54) is induced by exposure to ionizing radiation. The lung was used as a model to study the role of ICAM-1 in the pathogenesis of the radiation-induced inflammation-like response. ICAM-1 expression increased in the pulmonary microvascular endothelium and not in the endothelium of larger pulmonary vessels following treatment of mice with thoracic irradiation. To quantify radiation-induced ICAM-1 expression, we utilized fluorescence-activated cell sorting analysis of anti-ICAM-1 antibody labeling of pulmonary microvascular endothelial cells from human cadaver donors (HMVEC-L cells). Fluorochrome conjugates and UV microscopy were used to quantify the fluorescence intensity of ICAM in the irradiated lung. These studies showed a dose- and time-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium. Peak expression occurred at 24 h, while threshold dose was as low as 2 Gy. To determine whether ICAM-1 is required for inflammatory cell infiltration into the irradiated lung, the anti-ICAM-1 blocking antibody was administered by tail vein injection to mice following thoracic irradiation. Inflammatory cells were quantified by immunofluorescence for leukocyte common antigen (CD45). Mice treated with the anti-ICAM-1 blocking antibody showed attenuation of inflammatory cell infiltration into the lung in response to ionizing radiation exposure. To verify the requirement of ICAM-1 in the inflammation-like radiation response, we utilized the ICAM-1 knockout mouse. ICAM-1 was not expressed in the lungs of ICAM-1-deficient mice following treatment with thoracic irradiation. ICAM-1 knockout mice had no increase in the inflammatory cell infiltration into the lung in response to thoracic irradiation. These studies demonstrate a radiation dose-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium, and show that ICAM-1 is required for inflammatory cell infiltration

  20. Radiation-induced fibrosis: mechanisms and implications for therapy

    PubMed Central

    Straub, Jeffrey M.; New, Jacob; Hamilton, Chase D.; Lominska, Chris; Shnayder, Yelizaveta

    2015-01-01

    Purpose Radiation-induced fibrosis (RIF) is a long-term side effect of external beam radiation therapy for the treatment of cancer. It results in a multitude of symptoms that significantly impact quality of life. Understanding the mechanisms of RIF-induced changes is essential to developing effective strategies to prevent long-term disability and discomfort following radiation therapy. In this review, we describe the current understanding of the etiology, clinical presentation, pathogenesis, treatment, and directions of future therapy for this condition. Methods A literature review of publications describing mechanisms or treatments of RIF was performed. Specific databases utilized included PubMed and clinicaltrials.gov, using keywords “Radiation-Induced Fibrosis,” “Radiotherapy Complications,” “Fibrosis Therapy,” and other closely related terms. Results RIF is the result of a misguided wound healing response. In addition to causing direct DNA damage, ionizing radiation generates reactive oxygen and nitrogen species that lead to localized inflammation. This inflammatory process ultimately evolves into a fibrotic one characterized by increased collagen deposition, poor vascularity, and scarring. Tumor growth factor beta serves as the primary mediator in this response along with a host of other cytokines and growth factors. Current therapies have largely been directed toward these molecular targets and their associated signaling pathways. Conclusion Although RIF is widely prevalent among patients undergoing radiation therapy and significantly impacts quality of life, there is still much to learn about its pathogenesis and mechanisms. Current treatments have stemmed from this understanding, and it is anticipated that further elucidation will be essential for the development of more effective therapies. PMID:25910988

  1. Radiation-induced fibrosis: mechanisms and implications for therapy.

    PubMed

    Straub, Jeffrey M; New, Jacob; Hamilton, Chase D; Lominska, Chris; Shnayder, Yelizaveta; Thomas, Sufi M

    2015-11-01

    Radiation-induced fibrosis (RIF) is a long-term side effect of external beam radiation therapy for the treatment of cancer. It results in a multitude of symptoms that significantly impact quality of life. Understanding the mechanisms of RIF-induced changes is essential to developing effective strategies to prevent long-term disability and discomfort following radiation therapy. In this review, we describe the current understanding of the etiology, clinical presentation, pathogenesis, treatment, and directions of future therapy for this condition. A literature review of publications describing mechanisms or treatments of RIF was performed. Specific databases utilized included PubMed and clinicaltrials.gov, using keywords "Radiation-Induced Fibrosis," "Radiotherapy Complications," "Fibrosis Therapy," and other closely related terms. RIF is the result of a misguided wound healing response. In addition to causing direct DNA damage, ionizing radiation generates reactive oxygen and nitrogen species that lead to localized inflammation. This inflammatory process ultimately evolves into a fibrotic one characterized by increased collagen deposition, poor vascularity, and scarring. Tumor growth factor beta serves as the primary mediator in this response along with a host of other cytokines and growth factors. Current therapies have largely been directed toward these molecular targets and their associated signaling pathways. Although RIF is widely prevalent among patients undergoing radiation therapy and significantly impacts quality of life, there is still much to learn about its pathogenesis and mechanisms. Current treatments have stemmed from this understanding, and it is anticipated that further elucidation will be essential for the development of more effective therapies.

  2. Modeling radiation induced segregation in Iron-Chromium alloys

    SciTech Connect

    Senninger, Oriane; Soisson, Frederic; Martinez Saez, Enrique; Nastar, Maylise; Fu, Chu-Chun; Brechet, Yves

    2015-10-16

    Radiation induced segregation in ferritic Fe-Cr alloys is studied by Atomistic Kinetic Monte Carlo simulations that include di usion of chemical species by vacancy and interstitial migration, recombination, and elimination at sinks. The parameters of the di usion model are tted to DFT calculations. Transport coe cients that control the coupling between di usion of defects and chemical species are measured in dilute and concentrated alloys. Radiation induced segregation near grain boundaries is directly simulated with this model. We nd that the di usion of vacancies toward sinks leads to a Cr depletion. Meanwhile, the di usion of self-interstitials causes an enrichment of Cr in the vicinity of sinks. For concentrations lower than 15%Cr, we predict that sinks will be enriched with Cr for temperatures lower than a threshold. When the temperature is above this threshold value, the sinks will be depleted in Cr. These results are compared to previous experimental studies and models. Cases of radiation induced precipitation and radiation accelerated precipitation are considered.

  3. Radiation-induced transmissable chromosomal instability in haemopoietic stem cells

    NASA Astrophysics Data System (ADS)

    Kadhim, M. A.; Wright, E. G.

    Heritable radiation-induced genetic alterations have long been assumed to be ``fixed'' within the first cell division. However, there is a growing body of evidence that a considerable fraction of cells surviving radiation exposure appear normal, but a variety of mutational changes arise in their progeny due to a transmissible genomic instability. In our investigations of G-banded metaphases, non-clonal cytogenetic aberrations, predominantly chromatid-type aberrations, have been observed in the clonal descendants of murine and human haemopoietic stem cells surviving low doses (~1 track per cell) of alpha-particle irradiations. The data are consistent with a transmissible genetic instability induced in a stem cell resulting in a diversity of chromosomal aberrations in its clonal progeny many cell divisions later. Recent studies have demonstrated that the instability phenotype persists in vivo and that the expression of chromosomal instability has a strong dependence on the genetic characteristics of the irradiated cell. At the time when cytogenetic aberrations are detected, an increased incidence of hprt mutations and apoptotic cells have been observed in the clonal descendants of alpha-irradiated murine haemopoietic stem cells. Thus, delayed chromosomal abnormalities, delayed cell death by apoptosis and late-arising specific gene mutations may reflect diverse consequences of radiation-induced genomic instability. The relationship, if any, between these effects is not established. Current studies suggest that expression of these delayed heritable effects is determined by the type of radiation exposure, type of cell and a variety of genetic factors.

  4. Modeling radiation induced segregation in Iron-Chromium alloys

    DOE PAGES

    Senninger, Oriane; Soisson, Frederic; Martinez Saez, Enrique; ...

    2015-10-16

    Radiation induced segregation in ferritic Fe-Cr alloys is studied by Atomistic Kinetic Monte Carlo simulations that include di usion of chemical species by vacancy and interstitial migration, recombination, and elimination at sinks. The parameters of the di usion model are tted to DFT calculations. Transport coe cients that control the coupling between di usion of defects and chemical species are measured in dilute and concentrated alloys. Radiation induced segregation near grain boundaries is directly simulated with this model. We nd that the di usion of vacancies toward sinks leads to a Cr depletion. Meanwhile, the di usion of self-interstitials causesmore » an enrichment of Cr in the vicinity of sinks. For concentrations lower than 15%Cr, we predict that sinks will be enriched with Cr for temperatures lower than a threshold. When the temperature is above this threshold value, the sinks will be depleted in Cr. These results are compared to previous experimental studies and models. Cases of radiation induced precipitation and radiation accelerated precipitation are considered.« less

  5. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    SciTech Connect

    Guy, J.; Mancuso, A.; Beck, R.; Moster, M.L.; Sedwick, L.A.; Quisling, R.G.; Rhoton, A.L. Jr.; Protzko, E.E.; Schiffman, J. )

    1991-03-01

    Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

  6. Chromosome aberrations induced by high-LET radiations

    NASA Technical Reports Server (NTRS)

    Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Cucinotta, Francis A.

    2004-01-01

    Measurements of chromosome aberrations in peripheral blood lymphocytes are currently the most sensitive and reliable indicator of radiation exposure that can be used for biological dosimetry. This technique has been implemented recently to study radiation exposures incurred by astronauts during space flight, where a significant proportion of the dose is delivered by high-LET particle exposure. Traditional methods for the assessing of cytogenetic damage in mitotic cells collected at one time point after exposure may not be suitable for measuring high-LET radiation effects due to the drastic cell cycle perturbations and interphase cell death induced by this type of exposure. In this manuscript we review the recent advances in methodology used to study high-LET induced cytogenetic effects and evaluate the use of chemically-induced Premature Chromosome Condensation (PCC) as an alternative to metaphase analysis. Published data on the cytogenetic effects of in vitro exposures of high-LET radiation is reviewed, along with biodosimetry results from astronauts after short or long space missions.

  7. Chromosome aberrations induced by high-LET radiations

    NASA Technical Reports Server (NTRS)

    Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Cucinotta, Francis A.

    2004-01-01

    Measurements of chromosome aberrations in peripheral blood lymphocytes are currently the most sensitive and reliable indicator of radiation exposure that can be used for biological dosimetry. This technique has been implemented recently to study radiation exposures incurred by astronauts during space flight, where a significant proportion of the dose is delivered by high-LET particle exposure. Traditional methods for the assessing of cytogenetic damage in mitotic cells collected at one time point after exposure may not be suitable for measuring high-LET radiation effects due to the drastic cell cycle perturbations and interphase cell death induced by this type of exposure. In this manuscript we review the recent advances in methodology used to study high-LET induced cytogenetic effects and evaluate the use of chemically-induced Premature Chromosome Condensation (PCC) as an alternative to metaphase analysis. Published data on the cytogenetic effects of in vitro exposures of high-LET radiation is reviewed, along with biodosimetry results from astronauts after short or long space missions.

  8. Chromosome aberrations induced by high-LET radiations.

    PubMed

    Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Cucinotta, Francis A

    2004-12-01

    Measurements of chromosome aberrations in peripheral blood lymphocytes are currently the most sensitive and reliable indicator of radiation exposure that can be used for biological dosimetry. This technique has been implemented recently to study radiation exposures incurred by astronauts during space flight, where a significant proportion of the dose is delivered by high-LET particle exposure. Traditional methods for the assessing of cytogenetic damage in mitotic cells collected at one time point after exposure may not be suitable for measuring high-LET radiation effects due to the drastic cell cycle perturbations and interphase cell death induced by this type of exposure. In this manuscript we review the recent advances in methodology used to study high-LET induced cytogenetic effects and evaluate the use of chemically-induced Premature Chromosome Condensation (PCC) as an alternative to metaphase analysis. Published data on the cytogenetic effects of in vitro exposures of high-LET radiation is reviewed, along with biodosimetry results from astronauts after short or long space missions.

  9. Crosstalk between telomere maintenance and radiation effects: A key player in the process of radiation-induced carcinogenesis

    PubMed Central

    Shim, Grace; Ricoul, Michelle; Hempel, William M.; Azzam, Edouard I.; Sabatier, Laure

    2014-01-01

    It is well established that ionizing radiation induces chromosomal damage, both following direct radiation exposure and via non-targeted (bystander) effects, activating DNA damage repair pathways, of which the proteins are closely linked to telomeric proteins and telomere maintenance. Long-term propagation of this radiation-induced chromosomal damage during cell proliferation results in chromosomal instability. Many studies have shown the link between radiation exposure and radiation-induced changes in oxidative stress and DNA damage repair in both targeted and non-targeted cells. However, the effect of these factors on telomeres, long established as guardians of the genome, still remains to be clarified. In this review, we will focus on what is known about how telomeres are affected by exposure to low- and high-LET ionizing radiation and during proliferation, and will discuss how telomeres may be a key player in the process of radiation-induced carcinogenesis. PMID:24486376

  10. Oxidative Stress Mediates Radiation Lung Injury by Inducing Apoptosis

    SciTech Connect

    Zhang Yu; Zhang Xiuwu; Rabbani, Zahid N.; Jackson, Isabel L.; Vujaskovic, Zeljko

    2012-06-01

    Purpose: Apoptosis in irradiated normal lung tissue has been observed several weeks after radiation. However, the signaling pathway propagating cell death after radiation remains unknown. Methods and Materials: C57BL/6J mice were irradiated with 15 Gy to the whole thorax. Pro-apoptotic signaling was evaluated 6 weeks after radiation with or without administration of AEOL10150, a potent catalytic scavenger of reactive oxygen and nitrogen species. Results: Apoptosis was observed primarily in type I and type II pneumocytes and endothelium. Apoptosis correlated with increased PTEN expression, inhibition of downstream PI3K/AKT signaling, and increased p53 and Bax protein levels. Transforming growth factor-{beta}1, Nox4, and oxidative stress were also increased 6 weeks after radiation. Therapeutic administration of AEOL10150 suppressed pro-apoptotic signaling and dramatically reduced the number of apoptotic cells. Conclusion: Increased PTEN signaling after radiation results in apoptosis of lung parenchymal cells. We hypothesize that upregulation of PTEN is influenced by Nox4-derived oxidative stress. To our knowledge, this is the first study to highlight the role of PTEN in radiation-induced pulmonary toxicity.

  11. Radiation induced degradation of dyes--an overview.

    PubMed

    Rauf, M A; Ashraf, S Salman

    2009-07-15

    Synthetic dyes are a major part of our life. Products ranging from clothes to leather accessories to furniture all depend on extensive use of organic dyes. An unfortunate side effect of extensive use of these chemicals is that huge amounts of these potentially carcinogenic compounds enter our water supplies. Various advanced oxidation processes (AOPs) including the use of high-energy radiation have been developed to degrade these compounds. In this review, dye decoloration and degradation as a result of its exposure to high energy radiation such as gamma radiation and pulsed electron beam are discussed in detail. The role of various transient species such as H, OH and e(aq)(-) are taken into account as reported by various researchers. Literature citations in this area show that e(aq)(-) is very effective in decolorization but is less active in the further degradation of the products formed. The degradation of the dyes is initiated exclusively by OH attack on electron-rich sites of the dye molecules. Additionally, various parameters that affect the efficiency of radiation induced degradation of dyes, such as effect of radiation dose, oxygen, pH, hydrogen peroxide, added ions and dye classes are also reviewed and summarized. Lastly, pilot plant application of radiation for wastewater treatment is briefly discussed.

  12. Radiation-induced volatile hydrocarbon production in platelets

    SciTech Connect

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets.

  13. Skeletal Scintigraphy in Radiation-Induced Fibrosis With Lymphedema.

    PubMed

    Wang, Jieqi; Iranmanesh, Arya M; Oates, M Elizabeth

    2017-03-01

    Despite increasing reliance on CT, MRI, and FDG PET/CT for oncological imaging, whole-body skeletal scintigraphy remains a frontline modality for staging and surveillance of osseous metastatic disease. We present a 54-year-old woman with metastatic breast cancer who received palliative external-beam radiation to the left ilium. Serial follow-up Tc-MDP bone scans demonstrated progressive soft-tissue uptake in her left lower extremity, extending from thigh to leg, with associated enlargement and skin thickening, consistent with lymphedema related to radiation-induced fibrosis. Correlative abdominopelvic CT scans confirmed fibrotic changes in the left thigh.

  14. Challenges and Opportunities in Radiation-induced Hemorrhagic Cystitis

    PubMed Central

    Zwaans, Bernadette M.M.; Nicolai, Heinz G.; Chancellor, Michael B.; Lamb, Laura E.

    2016-01-01

    As diagnosis and treatment of cancer is improving, medical and social issues related to cancer survivorship are becoming more prevalent. Hemorrhagic cystitis (HC), a rare but serious disease that may affect patients after pelvic radiation or systemic chemotherapy, has significant unmet medical needs. Although no definitive treatment is currently available, various interventions are employed for HC. Effects of nonsurgical treatments for HC are of modest success and studies aiming to control radiation-induced bladder symptoms are lacking. In this review, we present current and advanced therapeutic strategies for HC to help cancer survivors deal with long-term urologic health issues. PMID:27601964

  15. Follistatin attenuates radiation-induced fibrosis in a murine model

    PubMed Central

    Forrester, Helen B.; de Kretser, David M.; Leong, Trevor; Hagekyriakou, Jim; Sprung, Carl N.

    2017-01-01

    Purpose Fibrosis can be a disabling, severe side effect of radiotherapy that can occur in patients, and for which there is currently no effective treatment. The activins, proteins which are members of the TGFβ superfamily, have a major role in stimulating the inflammatory response and subsequent fibrosis. Follistatin is an endogenous protein that binds the activins virtually irreversibly and inhibits their actions. These studies test if follistatin can attenuate the fibrotic response using a murine model of radiation-induced fibrosis. Experimental design C57BL/6 mice were subcutaneously injected with follistatin 24 hours prior to irradiation. Mice were irradiated in a 10 x 10 mm square area of the right hind leg with 35 Gy and were given follistatin 24 hours before radiation and three times a week for six months following. Leg extension was measured, and tissue was collected for histological and molecular analysis to evaluate the progression of the radiation-induced fibrosis. Results Leg extension was improved in follistatin treated mice compared to vehicle treated mice at six months after irradiation. Also, epidermal thickness and cell nucleus area of keratinocytes were decreased by the follistatin treatment compared to the cells in irradiated skin of control mice. Finally, the gene expression of transforming growth factor β1 (Tgfb1), and smooth muscle actin (Acta2) were decreased in the irradiated skin and Acta2 and inhibin βA subunit (Inhba) were decreased in the irradiated muscle of the follistatin treated mice. Conclusions Follistatin attenuated the radiation-induced fibrotic response in irradiated mice. These studies provide the data to support further investigation of the use of follistatin to reduce radiation-induced fibrosis in patients undergoing radiotherapy for cancer. PMID:28301516

  16. Follistatin attenuates radiation-induced fibrosis in a murine model.

    PubMed

    Forrester, Helen B; de Kretser, David M; Leong, Trevor; Hagekyriakou, Jim; Sprung, Carl N

    2017-01-01

    Fibrosis can be a disabling, severe side effect of radiotherapy that can occur in patients, and for which there is currently no effective treatment. The activins, proteins which are members of the TGFβ superfamily, have a major role in stimulating the inflammatory response and subsequent fibrosis. Follistatin is an endogenous protein that binds the activins virtually irreversibly and inhibits their actions. These studies test if follistatin can attenuate the fibrotic response using a murine model of radiation-induced fibrosis. C57BL/6 mice were subcutaneously injected with follistatin 24 hours prior to irradiation. Mice were irradiated in a 10 x 10 mm square area of the right hind leg with 35 Gy and were given follistatin 24 hours before radiation and three times a week for six months following. Leg extension was measured, and tissue was collected for histological and molecular analysis to evaluate the progression of the radiation-induced fibrosis. Leg extension was improved in follistatin treated mice compared to vehicle treated mice at six months after irradiation. Also, epidermal thickness and cell nucleus area of keratinocytes were decreased by the follistatin treatment compared to the cells in irradiated skin of control mice. Finally, the gene expression of transforming growth factor β1 (Tgfb1), and smooth muscle actin (Acta2) were decreased in the irradiated skin and Acta2 and inhibin βA subunit (Inhba) were decreased in the irradiated muscle of the follistatin treated mice. Follistatin attenuated the radiation-induced fibrotic response in irradiated mice. These studies provide the data to support further investigation of the use of follistatin to reduce radiation-induced fibrosis in patients undergoing radiotherapy for cancer.

  17. Genetic Screen Reveals Link between the Maternal Effect Sterile Gene mes-1 and Pseudomonas aeruginosa-induced Neurodegeneration in Caenorhabditis elegans*

    PubMed Central

    Wu, Qiuli; Cao, Xiou; Yan, Dong; Wang, Dayong; Aballay, Alejandro

    2015-01-01

    Increasing evidence indicates that immune responses to microbial infections may contribute to neurodegenerative diseases. Here, we show that Pseudomonas aeruginosa infection of Caenorhabditis elegans causes a number of neural changes that are hallmarks of neurodegeneration. Using an unbiased genetic screen to identify genes involved in the control of P. aeruginosa-induced neurodegeneration, we identified mes-1, which encodes a receptor tyrosine kinase-like protein that is required for unequal cell divisions in the early embryonic germ line. We showed that sterile but not fertile mes-1 animals were resistant to neurodegeneration induced by P. aeruginosa infection. Similar results were observed using animals carrying a mutation in the maternal effect gene pgl-1, which is required for postembryonic germ line development, and the germ line-deficient strains glp-1 and glp-4. Additional studies indicated that the FOXO transcription factor DAF-16 is required for resistance to P. aeruginosa-induced neurodegeneration in germ line-deficient strains. Thus, our results demonstrate that P. aeruginosa infection results in neurodegeneration phenotypes in C. elegans that are controlled by the germ line in a cell-nonautonomous manner. PMID:26475858

  18. Genetic Screen Reveals Link between the Maternal Effect Sterile Gene mes-1 and Pseudomonas aeruginosa-induced Neurodegeneration in Caenorhabditis elegans.

    PubMed

    Wu, Qiuli; Cao, Xiou; Yan, Dong; Wang, Dayong; Aballay, Alejandro

    2015-12-04

    Increasing evidence indicates that immune responses to microbial infections may contribute to neurodegenerative diseases. Here, we show that Pseudomonas aeruginosa infection of Caenorhabditis elegans causes a number of neural changes that are hallmarks of neurodegeneration. Using an unbiased genetic screen to identify genes involved in the control of P. aeruginosa-induced neurodegeneration, we identified mes-1, which encodes a receptor tyrosine kinase-like protein that is required for unequal cell divisions in the early embryonic germ line. We showed that sterile but not fertile mes-1 animals were resistant to neurodegeneration induced by P. aeruginosa infection. Similar results were observed using animals carrying a mutation in the maternal effect gene pgl-1, which is required for postembryonic germ line development, and the germ line-deficient strains glp-1 and glp-4. Additional studies indicated that the FOXO transcription factor DAF-16 is required for resistance to P. aeruginosa-induced neurodegeneration in germ line-deficient strains. Thus, our results demonstrate that P. aeruginosa infection results in neurodegeneration phenotypes in C. elegans that are controlled by the germ line in a cell-nonautonomous manner. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    NASA Astrophysics Data System (ADS)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together

  20. New sterilization technologies alternative to ethylene oxide

    NASA Astrophysics Data System (ADS)

    Tabrizian, Maryam; Lerouge, Sophie; Debrie, Anne; Yahia, L'Hocine

    1997-06-01

    Sterilization of biomedical devices may induce bulk and surface modification, responsible for the decrease or loss of their biofunctionality. Pure ethylene oxide (EO) at low temperature and new alternative techniques such as cold gas plasma sterilization have been developed for heat-sensitive polymers. There is a lack of the knowledge concerning their safety in terms of materials damage and consequences on the biofunctionality of sterilized devices. The objective of our work consists in studying bulk and surface changes in biomedical devices induced by these two sterilization techniques. Samples from PVC, Polyurethane, Polyacrylate and Polyethylene-based medical devices are subjected to 1, 5, and 10 sterilization cycles by Steri-Vac-3M (pure EO), Sterrad-100$TM, J&J (gas plasma + H2O2), and studied by X-rays photoelectron spectroscopy. Preliminary results show an increasing in Oxygen/Carbon ratio by a factor of 1.3 to 4.4 between the first and tenth cycle indicating the surface oxidation by gas plasma sterilization processes. Some changes in C-C chemical bounding are associated with EO sterilization.

  1. Chronic radiation-induced dermatitis: challenges and solutions

    PubMed Central

    Spałek, Mateusz

    2016-01-01

    Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients’ quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF). RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and radiomics that allow scientists and clinicians to select patients who are at risk of the development of chronic radiation dermatitis. Novel treatment methods and clinical

  2. Opportunities for nutritional amelioration of radiation-induced cellular damage

    NASA Technical Reports Server (NTRS)

    Turner, Nancy D.; Braby, Leslie A.; Ford, John; Lupton, Joanne R.

    2002-01-01

    The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic radiation exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic radiation. Therefore, radiation poses a major, currently unresolvable risk for astronauts, especially for long-duration space flights. The major detrimental radiation effects that are of primary concern for long-duration space flights are damage to the lens of the eye, damage to the immune system, damage to the central nervous system, and cancer. In addition to the direct damage to biological molecules in cells, radiation exposure induces oxidative damage. Many natural antioxidants, whether consumed before or after radiation exposure, are able to confer some level of radioprotection. In addition to achieving beneficial effects from long-known antioxidants such as vitamins E and C and folic acid, some protection is conferred by several recently discovered antioxidant molecules, such as flavonoids, epigallocatechin, and other polyphenols. Somewhat counterintuitive is the protection provided by diets containing elevated levels of omega-3 polyunsaturated fatty acids, considering they are thought to be prone to peroxidation. Even with the information we have at our disposal, it will be difficult to predict the types of dietary modifications that can best reduce the risk of radiation exposure to astronauts, those living on Earth, or those enduring diagnostic or therapeutic radiation exposure. Much more work must be done in humans, whether on Earth or, preferably, in space, before we are able to make concrete recommendations.

  3. Opportunities for nutritional amelioration of radiation-induced cellular damage

    NASA Technical Reports Server (NTRS)

    Turner, Nancy D.; Braby, Leslie A.; Ford, John; Lupton, Joanne R.

    2002-01-01

    The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic radiation exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic radiation. Therefore, radiation poses a major, currently unresolvable risk for astronauts, especially for long-duration space flights. The major detrimental radiation effects that are of primary concern for long-duration space flights are damage to the lens of the eye, damage to the immune system, damage to the central nervous system, and cancer. In addition to the direct damage to biological molecules in cells, radiation exposure induces oxidative damage. Many natural antioxidants, whether consumed before or after radiation exposure, are able to confer some level of radioprotection. In addition to achieving beneficial effects from long-known antioxidants such as vitamins E and C and folic acid, some protection is conferred by several recently discovered antioxidant molecules, such as flavonoids, epigallocatechin, and other polyphenols. Somewhat counterintuitive is the protection provided by diets containing elevated levels of omega-3 polyunsaturated fatty acids, considering they are thought to be prone to peroxidation. Even with the information we have at our disposal, it will be difficult to predict the types of dietary modifications that can best reduce the risk of radiation exposure to astronauts, those living on Earth, or those enduring diagnostic or therapeutic radiation exposure. Much more work must be done in humans, whether on Earth or, preferably, in space, before we are able to make concrete recommendations.

  4. Opportunities for nutritional amelioration of radiation-induced cellular damage.

    PubMed

    Turner, Nancy D; Braby, Leslie A; Ford, John; Lupton, Joanne R

    2002-10-01

    The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic radiation exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic radiation. Therefore, radiation poses a major, currently unresolvable risk for astronauts, especially for long-duration space flights. The major detrimental radiation effects that are of primary concern for long-duration space flights are damage to the lens of the eye, damage to the immune system, damage to the central nervous system, and cancer. In addition to the direct damage to biological molecules in cells, radiation exposure induces oxidative damage. Many natural antioxidants, whether consumed before or after radiation exposure, are able to confer some level of radioprotection. In addition to achieving beneficial effects from long-known antioxidants such as vitamins E and C and folic acid, some protection is conferred by several recently discovered antioxidant molecules, such as flavonoids, epigallocatechin, and other polyphenols. Somewhat counterintuitive is the protection provided by diets containing elevated levels of omega-3 polyunsaturated fatty acids, considering they are thought to be prone to peroxidation. Even with the information we have at our disposal, it will be difficult to predict the types of dietary modifications that can best reduce the risk of radiation exposure to astronauts, those living on Earth, or those enduring diagnostic or therapeutic radiation exposure. Much more work must be done in humans, whether on Earth or, preferably, in space, before we are able to make concrete recommendations.

  5. Chronic radiation-induced dermatitis: challenges and solutions.

    PubMed

    Spałek, Mateusz

    2016-01-01

    Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients' quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF). RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and radiomics that allow scientists and clinicians to select patients who are at risk of the development of chronic radiation dermatitis. Novel treatment methods and clinical

  6. [Sterilization of women].

    PubMed

    Hirsch, H A

    1984-09-01

    Voluntary sterilization is a permanent method of contraception. Therefore medical counseling of patients desiring sterilization is of utmost importance and should include documented incidence of failure (i.e., pregancy), complication risks, and if necessary, the various factors influencing successful reversal, although it should be emphasized that reversal can never be guaranteed. Laproscopic sterilization has proven very successful. Comparison of the advantages and disadvantages of the most used methods appears in Table 7. The most commonly used method is bipolar electrocoagulation in the isthmic tubal section. Unipolar electrocoagulation should not be used. Hysterectomy is too major an operation to be used solely for sterilization purposes, and is indicated only when other procedures have been eliminated. Pregnancy in failed sterilizations is approximately 8-10/1000 using the current methods, and an overwhelming number of these pregnancies are extrauterine. The rate of complications is lowest in laparoscopic interval sterilizations using local anesthesia. Approximately 1% of sterilized women desired reversal, despite preoperative counseling. The success rate of reversal is most favorable when the sterilization was perfomed in the isthmic tubal section with little destruction of tissue (by the clip method), the tubal segments are long, and the time since sterilization is less than 5 years. Reversal is not possible after fimbriectomy.

  7. Ability of radiation therapists to assess radiation-induced skin toxicity.

    PubMed

    Acharya, Urvi; Cox, Jennifer; Rinks, Marianne; Gaur, Pankaj; Back, Michael

    2013-06-01

    Radiation therapy has seen enhancement of the radiation therapist (RT) role, with RTs and nurses performing duties that were traditionally in the radiation oncologist's (RO) domain. This study aimed to assess whether RTs can consistently grade radiation-induced skin toxicity and their concordance with the gradings given by ROs. Digital photographs of skin reactions were taken at weeks 1, 3 and 6 of radiotherapy on nine patients with breast cancer. The randomly ordered photographs were reviewed once by eight ROs and four RO registrars and on two occasions separated by 6 weeks by 17 RTs. All graded the skin toxicities using the revised Radiation Therapy Oncology Group system. No significant difference was seen between the median scores of the RTs at the first scoring session and the RO/Registrar group. The RTs at both measurement times showed greater inter-rater reliability than the RO/Registrars (W = 0.6866, time 1 and 0.6981 time 2, vs. 0.6517), with the experienced RTs the most consistent (W = 0.7078). The RTs also showed high intra-rater reliability (rho = 0.8461, P < 0.0010). These results from RTs with no specific preparation indicate that experienced RTs could assess breast cancer skin toxicity as part of their role. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

  8. Cosmic-ray induced radiation in low-orbit space objects

    SciTech Connect

    Sandmeier, H.A.

    1980-09-01

    The induced radiation whole body dose received by astronauts in earth orbit is calculated. The induced radiation results from the interaction of primary cosmic rays with the mass of the satellite or space station. (ACR)

  9. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    NASA Technical Reports Server (NTRS)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low

  10. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    NASA Technical Reports Server (NTRS)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low

  11. Barriers to Radiation-Induced In Situ Tumor Vaccination

    PubMed Central

    Wennerberg, Erik; Lhuillier, Claire; Vanpouille-Box, Claire; Pilones, Karsten A.; García-Martínez, Elena; Rudqvist, Nils-Petter; Formenti, Silvia C.; Demaria, Sandra

    2017-01-01

    The immunostimulatory properties of radiation therapy (RT) have recently generated widespread interest due to preclinical and clinical evidence that tumor-localized RT can sometimes induce antitumor immune responses mediating regression of non-irradiated metastases (abscopal effect). The ability of RT to activate antitumor T cells explains the synergy of RT with immune checkpoint inhibitors, which has been well documented in mouse tumor models and is supported by observations of more frequent abscopal responses in patients refractory to immunotherapy who receive RT during immunotherapy. However, abscopal responses following RT remain relatively rare in the clinic, and antitumor immune responses are not effectively induced by RT against poorly immunogenic mouse tumors. This suggests that in order to improve the pro-immunogenic effects of RT, it is necessary to identify and overcome the barriers that pre-exist and/or are induced by RT in the tumor microenvironment. On the one hand, RT induces an immunogenic death of cancer cells associated with release of powerful danger signals that are essential to recruit and activate dendritic cells (DCs) and initiate antitumor immune responses. On the other hand, RT can promote the generation of immunosuppressive mediators that hinder DCs activation and impair the function of effector T cells. In this review, we discuss current evidence that several inhibitory pathways are induced and modulated in irradiated tumors. In particular, we will focus on factors that regulate and limit radiation-induced immunogenicity and emphasize current research on actionable targets that could increase the effectiveness of radiation-induced in situ tumor vaccination. PMID:28348554

  12. Secretion of Protective Antigens by Tissue-Stage Nematode Larvae Revealed by Proteomic Analysis and Vaccination-Induced Sterile Immunity

    PubMed Central

    Hewitson, James P.; Ivens, Al C.; Harcus, Yvonne; Filbey, Kara J.; McSorley, Henry J.; Murray, Janice; Bridgett, Stephen; Ashford, David; Dowle, Adam A.; Maizels, Rick M.

    2013-01-01

    Gastrointestinal nematode parasites infect over 1 billion humans, with little evidence for generation of sterilising immunity. These helminths are highly adapted to their mammalian host, following a developmental program through successive niches, while effectively down-modulating host immune responsiveness. Larvae of Heligmosomoides polygyrus, for example, encyst in the intestinal submucosa, before emerging as adult worms into the duodenal lumen. Adults release immunomodulatory excretory-secretory (ES) products, but mice immunised with adult H. polygyrus ES become fully immune to challenge infection. ES products of the intestinal wall 4th stage (L4) larvae are similarly important in host-parasite interactions, as they readily generate sterile immunity against infection, while released material from the egg stage is ineffective. Proteomic analyses of L4 ES identifies protective antigen targets as well as potential tissue-phase immunomodulatory molecules, using as comparators the adult ES proteome and a profile of H. polygyrus egg-released material. While 135 proteins are shared between L4 and adult ES, 72 are L4 ES-specific; L4-specific proteins correspond to those whose transcription is restricted to larval stages, while shared proteins are generally transcribed by all life cycle forms. Two protein families are more heavily represented in the L4 secretome, the Sushi domain, associated with complement regulation, and the ShK/SXC domain related to a toxin interfering with T cell signalling. Both adult and L4 ES contain extensive but distinct arrays of Venom allergen/Ancylostoma secreted protein-Like (VAL) members, with acetylcholinesterases (ACEs) and apyrase APY-3 particularly abundant in L4 ES. Serum antibodies from mice vaccinated with L4 and adult ES react strongly to the VAL-1 protein and to ACE-1, indicating that these two antigens represent major vaccine targets for this intestinal nematode. We have thus defined an extensive and novel repertoire of H

  13. Probabilistic methodology for estimating radiation-induced cancer risk

    SciTech Connect

    Dunning, D.E. Jr.; Leggett, R.W.; Williams, L.R.

    1981-01-01

    The RICRAC computer code was developed at Oak Ridge National Laboratory to provide a versatile and convenient methodology for radiation risk assessment. The code allows as input essentially any dose pattern commonly encountered in risk assessments for either acute or chronic exposures, and it includes consideration of the age structure of the exposed population. Results produced by the analysis include the probability of one or more radiation-induced cancer deaths in a specified population, expected numbers of deaths, and expected years of life lost as a result of premature fatalities. These calculatons include consideration of competing risks of death from all other causes. The program also generates a probability frequency distribution of the expected number of cancers in any specified cohort resulting from a given radiation dose. The methods may be applied to any specified population and dose scenario.

  14. UV laser radiation-induced modifications and microstructuring of glass

    NASA Astrophysics Data System (ADS)

    Talkenberg, Marc; Kreutz, Ernst-Wolfgang; Horn, Alexander; Jacquorie, Michael; Poprawe, Reinhart

    2002-06-01

    Modifications and microstructures are generated on the surface and in the volume of silicate glasses using pulsed UV laser radiation of small pulse length. During the interaction of pulsed excimer laser radiation and frequency-trippled Nd:YAG laser radiation with intensities below the removal-threshold of the cerium- and silver-doped multi-component silicate glass absorption centers in the UV are induced. Subsequent thermal treatment and wet chemical etching results in crystallization of the laser-illuminated absorbing region and in the fabrication of microstructures on the surface. Processing of sodalime- and boro-silicate glass with pulsed ArF excimer laser radiation and frequency-doubled Nd:YAG laser radiation with intensities above the removal-threshold leads to microstructures including the generation of microcracks on the surface and in the bulk. The dynamics and the transmission of the expanding plasma and changes in the refractive index of the glass are investigated with speckle photography using the pump and probe method. The determination of plasma emission and crack generation is carried out using high speed and Nomarski photography. Morphological and chemical properties of the debris generated under defined processing gas atmospheres are investigated with REM, white light interferometry, XPS and EPMA. Induced absorption and changes of the crystalline- phase are probed using optical-spectroscopy and XRD as well REM. On the basis of these investigations the processes of the generation of induced absorption centers and crystallization on the one hand and the generation of cracks and debris on the other hand as well as the quality of the produced microstructures is discussed.

  15. Sterilization. Disciplined microbial control.

    PubMed

    Miller, C H

    1991-04-01

    The goal of instrument processing is to protect patients by preventing cross-contamination from instruments. The processing involves a series of sequential steps aimed at removing and killing microbes on contaminated instruments and maintaining those instruments in an aseptic state until they are reused. These steps must be conducted carefully to assure success and to reduce chances of disease spread or physical injury to those handling the contaminated instruments. Presoaking begins the cleaning process and facilitates terminal cleaning by ultrasonic or manual scrubbing. If instruments are not properly cleaned, subsequent sterilization may be jeopardized by insulation of blood- or saliva-coated microbes from the sterilizing agent. Items that would be destroyed by heat should be cleaned and sterilized in a properly prepared glutaraldehyde solution. Cleaned instruments must be packaged prior to heat sterilization to protect them from recontamination after sterilization and before reuse. Sterilization of cleaned, packaged instruments in steam, chemical vapor, or dry heat sterilizers must involve proper loading, processing, drying, and cooling. Routine use of spore tests and chemical indicators will provide quality assessment of packaging procedures and operation of the sterilizer, as well as assist in identifying processed packages during distribution. Using the results of sterilization monitoring to adjust procedures as a means of assuring sterilization provides quality assurance to the office staff and to the patients that the instruments have been properly processed. Carefully handling storage and distribution of the sterilized instrument packs or trays reduces the chances for recontamination until the instruments are reused. Instrument processing is a major part of the office infection control program. It must be performed in a controlled manner with proper monitoring to achieve the desired outcome of patient protection.

  16. Capecitabine-induced radiation recall phenomenon: a case report

    PubMed Central

    Aguilar, José

    2013-01-01

    Radiation recall dermatitis is defined as an inflammatory reaction of the skin at the site of previous irradiation. Different drugs have been associated with triggering this phenomenon, and it can also affect other areas and organs where previous radiotherapy has been administered. The time gap between the inflammatory reaction and previous radiation can range from days to several years. We report a case of capecitabine-induced Radiation Therapy Oncology Group (RTOG) grade 4 (ulcerating dermatitis) recall skin toxicity of skin irradiated 3 years previously. To our knowledge, this is the first reported case of capecitabine-induced RTOG grade 4 (ulcerating dermatitis) recall skin toxicity of previously irradiated skin. Clinicians should be aware of this phenomenon, even when considering patients for whom it has been a long time since previous radiation therapy. This unusual and late drug side effect should be borne in mind in the differential diagnosis and management of advanced-disease patients as it may be confused with local relapse or infectious complication of previously operated areas. PMID:24555020

  17. Oligomer formation in the radiation-induced polymerization of styrene

    NASA Astrophysics Data System (ADS)

    Harayma, Hiroshi; Al-Sheikhly, Mohamad; Silverman, Joseph

    2003-12-01

    Analyses of the oligomers formed in radiation-induced polymerization of purified styrene were performed. The principal dimeric products were cis- and trans-diphenyl-cyclobutane with a relatively small amount of 1-phenyltetralin; the trimeric products were the optical isomers of 1-phenyl-4-[1'-phenylethyl-(1')]-tetralin in gamma-ray and 60 MeV proton irradiation. Oligomer formation increased with increasing dose, but more gradually than the linear formation of high polymer with dose. The yield was 0.25-3.1 μmol/J at low doses and decreased to an asymptotic value of 0.15 at higher doses. It appears that oligomers act as chain transfer agents during the polymerization reaction which would account for the observed decrease in molecular weight of the high polymer with increase in dose. Although the thermal and radiation-induced polymerization of styrene have different initiation steps, the oligomers produced by both reactions are similar in composition.

  18. Image reconstruction with acoustic radiation force induced shear waves

    NASA Astrophysics Data System (ADS)

    McAleavey, Stephen A.; Nightingale, Kathryn R.; Stutz, Deborah L.; Hsu, Stephen J.; Trahey, Gregg E.

    2003-05-01

    Acoustic radiation force may be used to induce localized displacements within tissue. This phenomenon is used in Acoustic Radiation Force Impulse Imaging (ARFI), where short bursts of ultrasound deliver an impulsive force to a small region. The application of this transient force launches shear waves which propagate normally to the ultrasound beam axis. Measurements of the displacements induced by the propagating shear wave allow reconstruction of the local shear modulus, by wave tracking and inversion techniques. Here we present in vitro, ex vivo and in vivo measurements and images of shear modulus. Data were obtained with a single transducer, a conventional ultrasound scanner and specialized pulse sequences. Young's modulus values of 4 kPa, 13 kPa and 14 kPa were observed for fat, breast fibroadenoma, and skin. Shear modulus anisotropy in beef muscle was observed.

  19. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    NASA Astrophysics Data System (ADS)

    Jiang, Erkang; Wu, Lijun

    2009-04-01

    In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy α-particle irradiated and non-irradiated bystander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensitive to damage signals. Treated by c-PTIO(2-(4-carboxy-phenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide), a nitric oxide (NO) scavenger, the MN frequencies were effectively inhibited, showing that nitric oxide might be very important in mediating the enhanced damage. These results indicated that caffeine enhanced the low dose α-particle radiation-induced damage in irradiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE).

  20. [Radiation-induced and therapy-related AML/MDS].

    PubMed

    Inaba, Toshiya

    2009-10-01

    Radiation induced acute myeloid leukemia (AML) was recognized a century ago, soon after mankind found radiation. Atomic bomb survivors developed de novo AML with relatively short latency with very high frequency. By contrast, excess occurrence of myelodysplastic syndrome (MDS) as well as solid tumors was found decades late. This difference may be due to etiology that many de novo AML patients harbor chimeric leukemogenic genes caused by chromosomal translocations, while MDS patients rarely carry chimeras. In addition, epigenetic change would play important roles. Therapy related leukemia is mainly caused by topoisomerase II inhibitors that cause de novo AML with an 11q23 translocation or by alkyrating agents that induce MDS/AML with an AML1 point mutation and monosomy 7.

  1. Dose and volume impact on radiation-induced xerostomia.

    PubMed

    Marmiroli, Luca; Salvi, Giovanna; Caiazza, Adolfo; Di Rienzo, Luigi; Massaccesi, Mariangela; Murino, Paola; Macchia, Gabriella

    2005-01-01

    Radiation-induced xerostomia consists in the chronic dryness of the mouth caused by parotid gland irradiation. Parotid glands produce approximately 60% of saliva while the rest is secreted by submandibular and accessory salivary glands. Methods of measuring the salivary output are essentially represented by 99mTc-pertechnate scintigraphy or simpler albeit less accurate methods in stimulated or unstimulated saliva. There are subjective and objective criteria of classification and grading of the secretion of saliva. Radiation-induced xerostomia, namely the residual salivary gland function is evidently associated with the mean dose absorbed. The salivary output tends to decrease after the end of radiotherapy. The partial dose-volume is substantially correlated with the mean dose to the whole gland. As for ipsilateral irradiation for head and neck cancer, conformal RT or IMRT allow to spare the contralateral parotid gland without increasing the risk of contralateral nodal recurrences. The monitoring system of late toxicity used by the authors is presented.

  2. Perinatal radiation-induced renal damage in the beagle

    SciTech Connect

    Jaenke, R.S.; Angleton, G.M. )

    1990-04-01

    The developing perinatal kidney is particularly sensitive to radiation. The pathogenesis of the radiation-induced lesion is related to the destruction of outer cortical developing nephrons and direct radiation injury with secondary hemodynamic alterations in remnant nephrons. In this study, which is part of a life span investigation of the effects of whole-body gamma radiation during prenatal and early postnatal life, dogs were given 0, 0.16, 0.83, or 1.25 Gy irradiation at either 55 days postcoitus or 2 days postpartum and were examined morphometrically and histopathologically at 70 days of age. Although irradiated dogs showed no reduction in the total number of nephrons per kidney, there was a significant increase in the total number and relative percentage of immature, dysplastic glomeruli. In addition, deeper cortical glomeruli of irradiated kidneys exhibited mesangial sclerosis similar to that associated with progressive renal failure in our previous studies. These findings are in accord with those reported at doses of 2.24 to 3.57 Gy and demonstrate that the perinatal kidney is affected by radiation doses much lower than previously demonstrated.

  3. Ionizing Radiation-Induced Cataract in Interventional Cardiology Staff

    PubMed Central

    Bitarafan Rajabi, Ahmad; Noohi, Feridoun; Hashemi, Hassan; Haghjoo, Majid; Miraftab, Mohammad; Yaghoobi, Nahid; Rastgou, Fereydon; Malek, Hadi; Faghihi, Hoshang; Firouzabadi, Hassan; Asgari, Soheila; Rezvan, Farhad; Khosravi, Hamidreza; Soroush, Sara; Khabazkhoob, Mehdi

    2015-01-01

    Background: The use of ionizing radiation has led to advances in medical diagnosis and treatment. Objectives: The purpose of this study was to determine the risk of radiation cataractogenesis in the interventionists and staff performing various procedures in different interventional laboratories. Patients and Methods: This cohort study included 81 interventional cardiology staff. According to the working site, they were classified into 5 groups. The control group comprised 14 professional nurses who did not work in the interventional sites. Participants were assigned for lens assessment by two independent trained ophthalmologists blinded to the study. Results: The electrophysiology laboratory staff received higher doses of ionizing radiation (17.2 ± 11.9 mSv; P < 0.001). There was a significant positive correlation between the years of working experience and effective dose in the lens (P < 0.001). In general, our findings showed that the incidence of lens opacity was 79% (95% CI, 69.9-88.1) in participants with exposure (the case group) and our findings showed that the incidence of lenses opacity was 7.1% (95% CI:2.3-22.6) with the relative risk (RR) of 11.06 (P < 0.001). Conclusions: We believe that the risk of radiation-induced cataract in cardiology interventionists and staff depends on their work site. As the radiation dose increases, the prevalence of posterior eye changes increases. PMID:25789258

  4. Prosthodontic management of radiation induced xerostomic patient using flexible dentures

    PubMed Central

    Murthy, Varsha; V, Yuvraj; Nair, Preeti P; Thomas, Shaji

    2012-01-01

    Xerostomia causes discomfort for complete denture wearers as the tissues become dry and friable due to lack of lubricating properties of saliva. Common problems faced by such patients are glossitis, mucositis, angular chelitis, dysgeusia and difficulty in chewing and swallowing. This case report describes a new method in addressing such issues by using flexible complete denture construction in radiation induced xerostomic patient with minimal tissue damage during and after denture construction procedures. PMID:22605708

  5. Radiation-Induce Immune Modulation in Prostate Cancer

    DTIC Science & Technology

    2005-01-01

    Riverside, CA Invited Seminar: "The Proteasome as a Senor of Stress " 3/17/04 UCLA Department of Dentistry Monthly Seminar, Los Angeles, CA Invited...affects protective antitutnor imnmunity induced by Chymotrypsin-like activity was measured using 100 pM SucLLVY-7- AdVMARTI/DC vaccination amido -4...adjuvant activity was heightened if the cells were first stressed by radiation, indicating that injury can modulate this effect. In situ induction of

  6. Radiation-induced decomposition of PETN and TATB under pressure

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael; Liermann, Hanns-Peter; Yang, Wenge

    2008-10-02

    We have investigated decomposition of PETN and TATB induced by white synchrotron X-ray radiation in a diamond anvil cell at ambient temperature and two pressures, nearly ambient and about 6 GPa. The decomposition rate of TATB decreases significantly when it is pressurized to 5.9 GPa. The measurements were highly reproducible and allowed us to obtain decomposition rates and the order parameters of the reactions.

  7. Interlaboratory comparison of radiation-induced attenuation in optical fibers

    SciTech Connect

    Friebele, E.J.; Lyons, P.B.; Blackburn, J.C.; Henschel, H.; Johan, A.; Krinsky, J.A.; Robinson, A.; Schneider, W.; Smith, D.; Taylor, E.W.; Los Alamos National Lab., NM; Harry Diamond Labs., Adelphi, MD; Fraunhofer-Institut fuer Naturwissenschaftlich-Technische Trendanalysen , Euskirchen; Direction des Recherches, Etudes et Techni

    1989-08-01

    A comparison of the losses induced in step index multimode, graded index multimode and single mode fibers by pulsed radiation exposure has been made among 12 laboratories over a period of 5 years. The recoveries of the incremental attenuations from 10{sup -9} to 10{sup 1} s are reported. Although a standard set of measurement parameters was attempted, differences between the laboratories are evident; possible origins for these are discussed. 18 refs., 18 figs., 7 tabs.

  8. Perturbation-induced radiation by the Ablowitz-Ladik soliton.

    PubMed

    Doktorov, E V; Matsuka, N P; Rothos, V M

    2003-12-01

    An efficient formalism is elaborated to analytically describe dynamics of the Ablowitz-Ladik soliton in the presence of perturbations. This formalism is based on using the Riemann-Hilbert problem and provides the means of calculating evolution of the discrete soliton parameters, as well as shape distortion and perturbation-induced radiation effects. As an example, soliton characteristics are calculated for linear damping and quintic perturbations.

  9. Non-Mendelian Female Sterility in DROSOPHILA MELANOGASTER: Influence of Aging and Thermic Treatments. III. Cumulative Effects Induced by These Factors

    PubMed Central

    Bucheton, Alain

    1979-01-01

    Crosses between various strains of Drosophila melanogaster may give rise to a female sterility of non-Mendelian determination. Reduced fertility is observed in females, known as SF females, bred from crosses between females of "reactive" strains and males of "inducer" strains. The reduced fertility of the SF females is the result of an interaction between an extrachromosomal property, the reactivity, and a chromosomal factor, I. The extrachromosomal property varies considerably in its ability to reduce fertility. The fertility reduction of the SF females corresponds to what is known as the reactivity level of their reactive mothers. Two nongenetic factors can modify the level of reactivity: aging and temperature. The action of aging is cumulative. When the flies of a reactive strain are submitted at each generation to the action of this factor, the level of reactivity of this strain is gradually modified. The modifications induced are reversible. Indeed, when such a modified strain is returned to standard breeding conditions, the reactivity returns progressively to its initial level. The effect of thermic treatments also seems to be cumulative and reversible. PMID:121289

  10. Intravesical Liposomal Tacrolimus Protects Against Radiation Cystitis Induced by 3-Beam Targeted Bladder Radiation

    PubMed Central

    Raja, Rajaganapathy Bharathi; Janicki, Joseph J.; Levanovich, Peter; Tyagi, Pradeep; Hafron, Jason; Chancellor, Michael B.; Krueger, Sarah; Marples, Brian

    2015-01-01

    Purpose This study primarily sought to determine if the Small Animal Radiation Research Platform (SARRP) can create a rat radiation cystitis (RC) model via targeted bladder irradiation (phase I). The response to treatment of early phase RC in rats via transurethral catheter instillation of liposomal tacrolimus (lipo-tacrolimus) was examined in phase II. Materials and Methods In phase I, 16 adult female Sprague-Dawley rats were used and their metabolic urination patterns were analyzed before and after exposure to 20, 30, or 40 Gy radiation. In phase II, irradiated rats were randomly assigned to receive a single instillation of either saline or lipo-tacrolimus. Results The 40 Gy radiation dose induced statistically significant reductions in inter-micturition intervals (IMI) compared to the lower doses of radiation. 40 Gy radiation caused a significant reduction in mean IMI by approximately 20 minutes (p < 0.0001). Histological analysis indicated degenerative type epithelial changes and urothelial swelling, with evidence of pseudocarcinomatous epithelial hyperplasia. Therefore, 40 Gy was chosen for the phase II efficacy study. There was no measurable change in total voided urine volume after irradiation or after instillation of lipo-tacrolimus or saline. Lipo-tacrolimus treatment significantly increased post-irradiation IMI values by approximately 30 minutes (p < 0.001) back to baseline levels. Conclusions The RC rat model demonstrated a dose-dependent decrease in IMI without inducing short-term skin or gastrointestinal damage. This study demonstrated that lipo-tacrolimus may be a promising new intravesical therapy for the rare and serious condition of RC. PMID:25839382

  11. UV radiation induces CXCL5 expression in human skin.

    PubMed

    Reichert, Olga; Kolbe, Ludger; Terstegen, Lara; Staeb, Franz; Wenck, Horst; Schmelz, Martin; Genth, Harald; Kaever, Volkhard; Roggenkamp, Dennis; Neufang, Gitta

    2015-04-01

    CXCL5 has recently been identified as a mediator of UVB-induced pain in rodents. To compare and to extend previous knowledge of cutaneous CXCL5 regulation, we performed a comprehensive study on the effects of UV radiation on CXCL5 regulation in human skin. Our results show a dose-dependent increase in CXCL5 protein in human skin after UV radiation. CXCL5 can be released by different cell types in the skin. We presumed that, in addition to immune cells, non-immune skin cells also contribute to UV-induced increase in CXCL5 protein. Analysis of monocultured dermal fibroblasts and keratinocytes revealed that only fibroblasts but not keratinocytes displayed up regulated CXCL5 levels after UV stimulation. Whereas UV treatment of human skin equivalents, induced epidermal CXCL5 mRNA and protein expression. Up regulation of epidermal CXCL5 was independent of keratinocyte differentiation and keratinocyte-keratinocyte interactions in epidermal layers. Our findings provide first evidence on the release of CXCL5 in UV-radiated human skin and the essential role of fibroblast-keratinocyte interaction in the regulation of epidermal CXCL5.

  12. Radiation-induced grain boundary segregation in austenitic stainless steels

    SciTech Connect

    Bruemmer, S.M.; Charlot, L.A.; Vetrano, J.S.; Simonen, E.P.

    1994-11-01

    Radiation-induced segregation (RIS) to grain boundaries in Fe-Ni-Cr-Si stainless alloys has been measured as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550{degrees}C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350{degrees}C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Although interfacial compositions were similar, the width of radiation-induced enrichment or depletion profiles increased consistently with increasing dose or temperature. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si peaked at levels approaching 10 at% after irradiation doses to 10 dpa at an intermediate temperature of 325{degrees}C. No evidence of grain boundary silicide precipitation was detected after irradiation at any temperature. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Comparisons to reported RIS in neutron-irradiated stainless steels revealed similar grain boundary compositional changes for both major alloying and impurity elements.

  13. UV and ionizing radiations induced DNA damage, differences and similarities

    NASA Astrophysics Data System (ADS)

    Ravanat, Jean-Luc; Douki, Thierry

    2016-11-01

    Both UV and ionizing radiations damage DNA. Two main mechanisms, so-called direct and indirect pathways, are involved in the degradation of DNA induced by ionizing radiations. The direct effect of radiation corresponds to direct ionization of DNA (one electron ejection) whereas indirect effects are produced by reactive oxygen species generated through water radiolysis, including the highly reactive hydroxyl radicals, which damage DNA. UV (and visible) light damages DNA by again two distinct mechanisms. UVC and to a lesser extend UVB photons are directly absorbed by DNA bases, generating their excited states that are at the origin of the formation of pyrimidine dimers. UVA (and visible) light by interaction with endogenous or exogenous photosensitizers induce the formation of DNA damage through photosensitization reactions. The excited photosensitizer is able to induce either a one-electron oxidation of DNA (type I) or to produce singlet oxygen (type II) that reacts with DNA. In addition, through an energy transfer from the excited photosensitizer to DNA bases (sometime called type III mechanism) formation of pyrimidine dimers could be produced. Interestingly it has been shown recently that pyrimidine dimers are also produced by direct absorption of UVA light by DNA, even if absorption of DNA bases at these wavelengths is very low. It should be stressed that some excited photosensitizers (such as psoralens) could add directly to DNA bases to generate adducts. The review will described the differences and similarities in terms of damage formation (structure and mechanisms) between these two physical genotoxic agents.

  14. Radiation-induced lichen sclerosus of the vulva : First report in the medical literature.

    PubMed

    Edwards, Lisa R; Privette, Emily D; Patterson, James W; Tchernev, Georgi; Chokoeva, Anastasiya Atanasova; Wollina, Uwe; Lotti, Torello; Wilson, Barbara B

    2017-03-01

    A 67-year-old woman presented with a firm plaque in the perineal region, 16 months after diagnosis of a high-grade basaloid squamous cell carcinoma of the vagina and treatment by external beam radiation therapy and vaginal cuff brachytherapy. The differential diagnosis included radiation-induced morphea, radiation dermatitis, or, possibly, radiation-induced lichen sclerosus. Biopsy findings, including special staining, confirmed the diagnosis of radiation-induced lichen sclerosus. To our knowledge, this is the first report of radiation-induced lichen sclerosus of the vulvar region.

  15. Irradiation Biology of Male Brown Marmorated Stink Bugs: Is there scope for the Sterile Insect Technique?

    PubMed

    Welsh, T; Stringer, L D; Caldwell, R; Carpenter, J E; Suckling, D M

    2017-10-05

    Brown marmorated stink bugs, Halyomorpha halys Stål (Hemiptera: Pentatomidae), are regularly intercepted, but there are few eradication tools. Currently, no sterile insect technique program exists for Hemiptera. Adult males were irradiated at 4-60 Gy, mated and their progeny reared for two generations, with mortality assessed at F1 egg, F1 adult and F2 egg stages. The F1 eggs showed a dose response to irradiation between 4 and 36 Gy, with 97% sterility at 16 Gy, and higher doses producing complete egg mortality. Only rare F1 survivors had progeny, but the F2 generation showed identical responses between maternal and paternal lines; most egg batches showed either very low or very high mortality. Irradiation with 16 Gy resulted in 98.5% sterility, cumulative over F1 and F2. Lack of a dose response at the F2 generation precludes the use of irradiation-induced inherited sterility. The conventional sterile insect technique appears possible by irradiation of males from ∼12-16 Gy. The effect of radiation dose on females is not known, thus we cannot conclude whether bi-sex release is feasible so for now the release of males only is recommended. More work is needed on the competitive fitness of irradiated males, and logistics such as mass rearing or field collection, in order to determine the feasibility of the approach.

  16. Oviposition preference of Cactoblastis cactorum (Lepidoptera:Pyralidae)in caged choice experiments and the influence of risk assessment of F1 sterility

    USDA-ARS?s Scientific Manuscript database

    Releases of lepidopteran biological control agents have successfully controlled invasive weed species. However, issues with non-target effects of released exotic agents have resulted in stringent pre-release host specificity testing. Use of inherited (F1) sterility, a radiation induced genetic con...

  17. Radiation-induced esophageal injury: A spectrum from esophagitis to cancer

    SciTech Connect

    Vanagunas, A.; Jacob, P.; Olinger, E. )

    1990-07-01

    Radiation esophagitis is a common but frequently unrecognized complication of therapeutic radiation to the neck, chest, or mediastinum. The spectrum of injury ranges from acute self-limited esophagitis to life-threatening esophageal perforation. Complications such as stricture or primary esophageal cancer may occur many years after irradiation, and their linkage to radiation may not be considered. Five cases of radiation-induced injury are described, and the spectrum of radiation-induced esophageal injury is reviewed.

  18. Supercritical carbon dioxide-based sterilization of decellularized heart valves.

    PubMed

    Hennessy, Ryan S; Jana, Soumen; Tefft, Brandon J; Helder, Meghana R; Young, Melissa D; Hennessy, Rebecca R; Stoyles, Nicholas J; Lerman, Amir

    2017-02-01

    The goal of this research project encompasses finding the most efficient and effective method of decellularized tissue sterilization. Aortic tissue grafts have been utilized to repair damaged or diseased valves. Although, the tissues for grafting are collected aseptically, it does not eradicate the risk of contamination nor disease transfer. Thus, sterilization of grafts is mandatory. Several techniques have been applied to sterilize grafts; however, each technique shows drawbacks. In this study, we compared several sterilization techniques: supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide for impact on the sterility and mechanical integrity of porcine decellularized aortic valves. Valve sterility was characterized by histology, microbe culture, and electron microscopy. Uniaxial tensile testing was conducted on the valve cusps along their circumferential orientation to study these sterilization techniques on their integrity. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile. The tensile strength of supercritical carbon dioxide treated valves (4.28 ± 0.22 MPa) was higher to those valves treated with electrolyzed water, gamma radiation, ethanol-peracetic acid and hydrogen peroxide (1.02 ± 0.15, 1.25 ± 0.25, 3.53 ± 0.41 and 0.37 ± 0.04 MPa, respectively). Superior sterility and integrity were found in the decellularized porcine aortic valves with supercritical carbon dioxide sterilization. This sterilization technique may hold promise for other decellularized soft tissues. Sterilization of grafts is essential. Supercritical carbon dioxide, electrolyzed water, gamma radiation, ethanol-peracetic acid, and hydrogen peroxide techniques were compared for impact on sterility and mechanical integrity of porcine decellularized aortic valves. Ethanol-peracetic acid and supercritical carbon dioxide treated valves were found to be sterile using histology, microbe

  19. [Radiation-induced tumors of the nervous system in man].

    PubMed

    Hubert, D; Bertin, M

    1993-11-01

    The risk of developing a tumor of the nervous system in humans is analysed in several studies of populations, exposed to ionising radiation for medical reasons, or exposed to military or occupational radiation. The main data come from series of patients who underwent radiotherapy during childhood: a high incidence of tumors of the nervous system is found after irradiation of one to a few grays as treatment of a benign disease (especially tinea capitis), as well as after irradiation at higher doses of a few tens of grays for the treatment of cancer (in particular cerebral irradiation in acute lymphoblastic leukaemia). The type of radiation-induced tumors is variable, but meningioma is more frequent after low doses and glioma and sarcoma after higher doses used in the treatment of neoplastic diseases. A dose-effect relationship appeared between the risk of tumor of the nervous system and the radiation dose. The risk was higher when radiation was delivered at a younger age. Much less data are available after radiotherapy in the adulthood, but an increased risk of cerebral tumor appears in the series of ankylosing spondylitis patients. As for the exposures to radiodiagnosis exams, the main problem is the risk of cerebral tumor in children whose mother has undergone abdominal or pelvic X-rays during pregnancy. No risk of neurologic tumor was found in the A-bomb survivors irradiated at Hiroshima and Nagasaki. Occupational exposure to ionising radiation has been incriminated in the first radiologists exposed to high doses. In nuclear industry workers, the results of epidemiological studies are contradictory and at the present time it is not possible to link their radiologic exposure with a risk of tumor of the nervous system. In populations living near nuclear plants, mortality due to tumors of the nervous system was not increased.

  20. Effects of Sterilizing Agents on Microorganisms

    DTIC Science & Technology

    1963-03-01

    vided either is valid at high temperatures. (4) Radiation La Bree, T. R., Fields, M. L., Desrosier, N. W. sterilization may become useful in the beverage ...e’sters, nisin , (’thhvln oxide, diepoxvbutane, (ight chemical formulations upon microbial numbers in hydrogen peroxide, formaldehyde

  1. IAEA/FAO interregional training course on use of radiation in insect control and entomology with special emphasis on the sterile insect technique. Final report, May 4--June 15, 1994

    SciTech Connect

    1994-12-31

    The principal focus of the course was the application of Radiation in Entomology to achieve Area Wide Pest Suppression or Eradication. To achieve this objective formal lectures, discussion groups, laboratory exercises and field trips were held covering the details of: (1) principles, programs and research of all aspects of the Sterile Insect Technique; (2) insect biology and control; (3) integrated pest management; (4) population dynamics and models related to the development of SIT and insect population suppression; (5) fundamentals of computers for helping in development of SIT; (6) the importance of economic considerations in formulating area wide pest management programs. The course included tours of local laboratories of the University, USDA, and the State Division of Plant Industry (DPI), and a site visit to a citrus production area in which the pest-free zone concept of pest management for fruit export is utilized.

  2. Radiation induced genome instability: multiscale modelling and data analysis

    NASA Astrophysics Data System (ADS)

    Andreev, Sergey; Eidelman, Yuri

    2012-07-01

    Genome instability (GI) is thought to be an important step in cancer induction and progression. Radiation induced GI is usually defined as genome alterations in the progeny of irradiated cells. The aim of this report is to demonstrate an opportunity for integrative analysis of radiation induced GI on the basis of multiscale modelling. Integrative, systems level modelling is necessary to assess different pathways resulting in GI in which a variety of genetic and epigenetic processes are involved. The multilevel modelling includes the Monte Carlo based simulation of several key processes involved in GI: DNA double strand breaks (DSBs) generation in cells initially irradiated as well as in descendants of irradiated cells, damage transmission through mitosis. Taking the cell-cycle-dependent generation of DNA/chromosome breakage into account ensures an advantage in estimating the contribution of different DNA damage response pathways to GI, as to nonhomologous vs homologous recombination repair mechanisms, the role of DSBs at telomeres or interstitial chromosomal sites, etc. The preliminary estimates show that both telomeric and non-telomeric DSB interactions are involved in delayed effects of radiation although differentially for different cell types. The computational experiments provide the data on the wide spectrum of GI endpoints (dicentrics, micronuclei, nonclonal translocations, chromatid exchanges, chromosome fragments) similar to those obtained experimentally for various cell lines under various experimental conditions. The modelling based analysis of experimental data demonstrates that radiation induced GI may be viewed as processes of delayed DSB induction/interaction/transmission being a key for quantification of GI. On the other hand, this conclusion is not sufficient to understand GI as a whole because factors of DNA non-damaging origin can also induce GI. Additionally, new data on induced pluripotent stem cells reveal that GI is acquired in normal mature

  3. Theoretical evaluation of induced radioactivity in food products by electron — or X-ray beam sterilization

    NASA Astrophysics Data System (ADS)

    Leboutet, H.; Aucouturier, J.

    We evaluate first the energy density for electrons or X-ray beams necessary to produce a reference level of 1 kilogray at the maximum of dose, as a function of energy, for electrons and bremsstrahlung photons ( BX rays), based on experimental data obtained on radio-therapy beams, from 4 to 32 MeV, and irradiation beams from production plant CARIC. Then from the production of neutrons on the tungsten target and from (γ n) reactions on the deuterium content of the irradiated food, the slowing down and capture of these neutrons is estimated. Radioisotopes can be produced by (γ n) reactions on iodine, and to a lesser extent on tin, lead, barium, etc., but the major contribution is neutron activation, where the more critical elements are sodium, chlorine, potassium, magnesium, phosphorus, calcium. Induced activity is compared to natural activity coming from potassium 40, carbon 14 and radium, contained in all foods. We conclude that for electrons up to 1 Mrad the induced activity remains of the order of a few percent of natural activity, for energies below 10-11 MeV. Bremsstrahlung X-ray irradiations can give comparable levels as soon as the energy of the generating electron beam is above 3 MeV. The induced activity decays within a few days. There is only a small increase of induced activity as the energy changes from 5 to 10 MeV, for the same total applied dose.

  4. Hydrogen Protects Mice from Radiation Induced Thymic Lymphoma in BALB/c Mice

    PubMed Central

    Zhao, Luqian; Zhou, Chuanfeng; Zhang, Jian; Gao, Fu; Li, Bailong; Chuai, Yunhai; Liu, Cong; Cai, Jianming

    2011-01-01

    Ionizing radiation (IR) is a well-known carcinogen, however the mechanism of radiation induced thymic lymphoma is not well known. Moreover, an easy and effective method to protect mice from radiation induced thymic lymphoma is still unknown. Hydrogen, or H2, is seldom regarded as an important agent in medical usage, especially as a therapeutic gas. Here in this study, we found that H2 protects mice from radiation induced thymic lymphoma in BALB/c mice. PMID:21448340

  5. Comparison of different types of phacoemulsification tips. II. Morphologic alterations induced by multiple steam sterilization cycles with and without use of enzyme detergents.

    PubMed

    Tsaousis, Konstantinos T; Werner, Liliana; Reiter, Nicholas; Perez, Jesus Paulo; Li, He J; Guan, Jia J; Mamalis, Nick

    2016-09-01

    To evaluate the alterations in the morphology and elemental composition of reusable phacoemulsification tips after cleaning and sterilization. John A. Moran Eye Center, Salt Lake City, Utah, USA. Experimental study. For the main experiment, 2 types of reusable phacoemulsification needles were studied. One tip of each type underwent 1, 2, and 3 autoclave sterilizations with the use of detergents followed by thorough rinsing with sterile water between cycles. Another set of tips underwent the same procedure but without rinsing. Subsequently, phaco tips were examined through scanning electron microscopy and energy-dispersive x-ray spectroscopy to assess morphologic changes and surface deposits. In a second experiment, tips of 8 different types (both reusable and single use) underwent 10 sterilization autoclave cycles without detergents. Residues, mostly comprised of carbon-containing material, were found in extensive areas of tips that were sterilization with enzymes and without rinsing. Smaller and fewer residues were found in tips after sterilization with the use of enzymes and thorough rinsing. Tips that underwent autoclave sterilization without detergents had no bulky deposits on their surface; they mostly had thin layers of sodium and chloride or material discoloration. Rinsing the phaco tips significantly reduced the size and number of residues after use of enzymatic detergents. However, detergent residues were detected on phaco tip surfaces even after thorough rinsing with sterile water. No major noticeable changes were observed in either single-use or reusable phaco tips after 10 cycles of sterilization without detergents. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Heat induced damage detection in composite materials by terahertz radiation

    NASA Astrophysics Data System (ADS)

    Radzieński, Maciej; Mieloszyk, Magdalena; Rahani, Ehsan Kabiri; Kundu, Tribikram; Ostachowicz, Wiesław

    2015-03-01

    In recent years electromagnetic Terahertz (THz) radiation or T-ray has been increasingly used for nondestructive evaluation of various materials such as polymer composites and porous foam tiles in which ultrasonic waves cannot penetrate but T-ray can. Most of these investigations have been limited to mechanical damage detection like inclusions, cracks, delaminations etc. So far only a few investigations have been reported on heat induced damage detection. Unlike mechanical damage the heat induced damage does not have a clear interface between the damaged part and the surrounding intact material from which electromagnetic waves can be reflected back. Difficulties associated with the heat induced damage detection in composite materials using T-ray are discussed in detail in this paper. T-ray measurements are compared for different levels of heat exposure of composite specimens.

  7. Gamma radiation induces hydrogen absorption by copper in water

    NASA Astrophysics Data System (ADS)

    Lousada, Cláudio M.; Soroka, Inna L.; Yagodzinskyy, Yuriy; Tarakina, Nadezda V.; Todoshchenko, Olga; Hänninen, Hannu; Korzhavyi, Pavel A.; Jonsson, Mats

    2016-04-01

    One of the most intricate issues of nuclear power is the long-term safety of repositories for radioactive waste. These repositories can have an impact on future generations for a period of time orders of magnitude longer than any known civilization. Several countries have considered copper as an outer corrosion barrier for canisters containing spent nuclear fuel. Among the many processes that must be considered in the safety assessments, radiation induced processes constitute a key-component. Here we show that copper metal immersed in water uptakes considerable amounts of hydrogen when exposed to γ-radiation. Additionally we show that the amount of hydrogen absorbed by copper depends on the total dose of radiation. At a dose of 69 kGy the uptake of hydrogen by metallic copper is 7 orders of magnitude higher than when the absorption is driven by H2(g) at a pressure of 1 atm in a non-irradiated dry system. Moreover, irradiation of copper in water causes corrosion of the metal and the formation of a variety of surface cavities, nanoparticle deposits, and islands of needle-shaped crystals. Hence, radiation enhanced uptake of hydrogen by spent nuclear fuel encapsulating materials should be taken into account in the safety assessments of nuclear waste repositories.

  8. G2-chromosome aberrations induced by high-LET radiations

    NASA Astrophysics Data System (ADS)

    Kawata, T.; Durante, M.; Furusawa, Y.; George, K.; Ito, H.; Wu, H.; Cucinotta, F. A.

    We report measurements of initial G2-chromatid breaks in normal human fibroblasts exposed to various types of high-LET particles. Exponentially growing AG 1522 cells were exposed to γ-rays or heavy ions. Chromosomes were prematurely condensed by calyculin A. Chromatid-type breaks and isochromatid-type breaks were scored separately. The dose response curves for the induction of total chromatid breaks (chromatid-type + isochromatid-type) and chromatid-type breaks were linear for each type of radiation. However, dose response curves for the induction of isochromatid-type breaks were linear for high-LET radiations and linear-quadratic for γ-rays. Relative biological effectiveness (RBE), calculated from total breaks, showed a LET dependent tendency with a peak at 55 keV/μm silicon (2.7) or 80 keV/μm carbon (2.7) and then decreased with LET (1.5 at 440 keV/μm). RBE for chromatid-type break peaked at 55 keV/μm (2.4) then decreased rapidly with LET. The RBE of 440 keV/μm iron particles was 0.7. The RBE calculated from induction of isochromatid-type breaks was much higher for high-LET radiations. It is concluded that the increased production of isochromatid-type breaks, induced by the densely ionizing track structure, is a signature of high-LET radiation exposure.

  9. Gamma radiation induces hydrogen absorption by copper in water

    PubMed Central

    Lousada, Cláudio M.; Soroka, Inna L.; Yagodzinskyy, Yuriy; Tarakina, Nadezda V.; Todoshchenko, Olga; Hänninen, Hannu; Korzhavyi, Pavel A.; Jonsson, Mats

    2016-01-01

    One of the most intricate issues of nuclear power is the long-term safety of repositories for radioactive waste. These repositories can have an impact on future generations for a period of time orders of magnitude longer than any known civilization. Several countries have considered copper as an outer corrosion barrier for canisters containing spent nuclear fuel. Among the many processes that must be considered in the safety assessments, radiation induced processes constitute a key-component. Here we show that copper metal immersed in water uptakes considerable amounts of hydrogen when exposed to γ-radiation. Additionally we show that the amount of hydrogen absorbed by copper depends on the total dose of radiation. At a dose of 69 kGy the uptake of hydrogen by metallic copper is 7 orders of magnitude higher than when the absorption is driven by H2(g) at a pressure of 1 atm in a non-irradiated dry system. Moreover, irradiation of copper in water causes corrosion of the metal and the formation of a variety of surface cavities, nanoparticle deposits, and islands of needle-shaped crystals. Hence, radiation enhanced uptake of hydrogen by spent nuclear fuel encapsulating materials should be taken into account in the safety assessments of nuclear waste repositories. PMID:27086752

  10. Radiation-induced volatile hydrocarbon production in platelets. Scientific report

    SciTech Connect

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Thrombocytopenia plays an important role in the development of the post-irradiation hemorrhagic syndrome. Although destruction of platelet precursors in bone marrow is a major effect of high-dose radiation exposure, the effects of radiation on preformed platelets are unclear. The latter is also of concern with respect to blood-banking practices since platelets are often irradiated at doses in the range of 20-50 Gy before transfusions to prevent graft-versus-host disease. With increasing emphasis on allogenic and autologous bone-marrow transplantation, transfusions of irradiated platelets are likely to rise. Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets.

  11. Radiation-induced immune responses: mechanisms and therapeutic perspectives

    PubMed Central

    Jeong, Hoibin; Bok, Seoyeon; Hong, Beom-Ju; Choi, Hyung-Seok

    2016-01-01

    Recent advancement in the radiotherapy technology has allowed conformal delivery of high doses of ionizing radiation precisely to the tumors while sparing large volume of the normal tissues, which have led to better clinical responses. Despite this technological advancement many advanced tumors often recur and they do so within the previously irradiated regions. How could tumors recur after receiving such high ablative doses of radiation? In this review, we outlined how radiation can elicit anti-tumor responses by introducing some of the cytokines that can be induced by ionizing radiation. We then discuss how tumor hypoxia, a major limiting factor responsible for failure of radiotherapy, may also negatively impact the anti-tumor responses. In addition, we highlight how there may be other populations of immune cells including regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs) that can be recruited to tumors interfering with the anti-tumor immunity. Finally, the impact of irradiation on tumor hypoxia and the immune responses according to different radiotherapy regimen is also delineated. It is indeed an exciting time to see that radiotherapy is being combined with immunotherapy in the clinic and we hope that this review can add an excitement to the field. PMID:27722125

  12. Gamma radiation induces hydrogen absorption by copper in water.

    PubMed

    Lousada, Cláudio M; Soroka, Inna L; Yagodzinskyy, Yuriy; Tarakina, Nadezda V; Todoshchenko, Olga; Hänninen, Hannu; Korzhavyi, Pavel A; Jonsson, Mats

    2016-04-18

    One of the most intricate issues of nuclear power is the long-term safety of repositories for radioactive waste. These repositories can have an impact on future generations for a period of time orders of magnitude longer than any known civilization. Several countries have considered copper as an outer corrosion barrier for canisters containing spent nuclear fuel. Among the many processes that must be considered in the safety assessments, radiation induced processes constitute a key-component. Here we show that copper metal immersed in water uptakes considerable amounts of hydrogen when exposed to γ-radiation. Additionally we show that the amount of hydrogen absorbed by copper depends on the total dose of radiation. At a dose of 69 kGy the uptake of hydrogen by metallic copper is 7 orders of magnitude higher than when the absorption is driven by H2(g) at a pressure of 1 atm in a non-irradiated dry system. Moreover, irradiation of copper in water causes corrosion of the metal and the formation of a variety of surface cavities, nanoparticle deposits, and islands of needle-shaped crystals. Hence, radiation enhanced uptake of hydrogen by spent nuclear fuel encapsulating materials should be taken into account in the safety assessments of nuclear waste repositories.

  13. Radiation-induced recurrent intestinal pseudo-obstruction

    SciTech Connect

    Conklin, J.L.; Anuras, S.

    1981-06-01

    The syndrome of intestinal pseudo-obstruction is a complex of signs and symptoms of intestinal obstruction without evidence of mechanical obstruction of the intestinal lumen. A patient with radiation-induced intestinal pseudoobstruction is described. The patient is a 74-year old woman with a history of chronic diarrhea, recurrent episodes of crampy abdominal pain, nausea and vomiting since receiving a 13,000 rad radiation dose to the pelvis in 1954. She has been hospitalized on many occasions for symptoms and signs of bowel obstruction. Upper gastrointestinal contrast roentgenograms with small bowel follow-through done during these episodes revealed multiple dilated loops of small bowel with no obstructing lesion. Barium enemas revealed no obstructing lesion. Each episode resolved with conservative therapy. Other secondary causes for intestinal pseudo-obstruction were ruled out in our patient. She gave no history of familial gastrointestinal disorders. Although postirradiation motility abnormalities have been demonstrated experimentally this is the first report of radiation induced intestinal pseudo-obstruction.

  14. Radiation-induced thymine base damage in replicating chromatin

    SciTech Connect

    Warters, R.L.; Childers, T.J.

    1982-06-01

    The efficiency of radiation-induced production of 5',6'-dihydroxydihydrothymine (t/sup ..gamma../)-type damage was determined in nascent and mature chromatin DNA for the dose range of 50 to 150 krad. These large doses affected neither the total fraction of nuclear DNA in chromatin subunits nor the nucleosome subunit repeat length. The DNA in nascent chromatin, however, was found to be 3.3 times more sensitive than mature chromatin DNA to ..gamma..-ray (/sup 137/Cs)-induced t/sup ..gamma../-type damage, while thymine damage of this type was uniformly distributed in the nucleosomal DNA of mature chromatin (i.e., in the nucleosome core and spacer DNA). The half-time for the transition of nascent DNA sensitivity to mature chromatin DNA sensitivity levels was the same as the half-time at 37/sup 0/C for the maturation of nascent into mature chromatin structure. The rate at which nascent chromatin matured was unaffected by radiation doses as large as 150 krad. The most logical explanation for the greater sensitivity of nascent DNA to radiation is the decreased concentration of histone chromosomal proteins in nascent chromatin.

  15. Sensitivity to Radiation-Induced Cancer in Hemochromatosis

    SciTech Connect

    Bull. Richard J.; Anderson, Larry E.

    2000-06-01

    The objectives of this pilot project using HFE-knockout homozygotes and heterozygotes are to (1) determine whether the knock-out mice have greater sensitivity to radiation-induced cancer of the colon, liver and breast, (2) establish the dependence of this sensitivity on the accumulation of iron, (3) determine the extent to which cell replication and apoptosis occur in these target tissues with varying iron load, and (4) correlate the increases in sensitivity with changes in insulin-related signaling in tumors and normal tissue from each target organ. Three experimental designs will be used in the pilot project. The sequence of experiments is designed to first explore the influence of iron load on the response and demonstrate that HFE knockout mice are more sensitive than the wild type to radiation-induced cancer in one or more of three target tissues (liver, colon and breast). The dose response relationships with a broader set of radiation doses will be explored in the second experiment. The final experiment is designed to explore the extent to which heterozygotes display the increased susceptibility to cancer induction and to independently assess the importance of iron load to the initiation versus promotion of tumors.

  16. Epigenetic determinants of space radiation-induced cognitive dysfunction

    PubMed Central

    Acharya, Munjal M.; Baddour, Al Anoud D.; Kawashita, Takumi; Allen, Barrett D.; Syage, Amber R.; Nguyen, Thuan H.; Yoon, Nicole; Giedzinski, Erich; Yu, Liping; Parihar, Vipan K.; Baulch, Janet E.

    2017-01-01

    Among the dangers to astronauts engaging in deep space missions such as a Mars expedition is exposure to radiations that put them at risk for severe cognitive dysfunction. These radiation-induced cognitive impairments are accompanied by functional and structural changes including oxidative stress, neuroinflammation, and degradation of neuronal architecture. The molecular mechanisms that dictate CNS function are multifaceted and it is unclear how irradiation induces persistent alterations in the brain. Among those determinants of cognitive function are neuroepigenetic mechanisms that translate radiation responses into altered gene expression and cellular phenotype. In this study, we have demonstrated a correlation between epigenetic aberrations and adverse effects of space relevant irradiation on cognition. In cognitively impaired irradiated mice we observed increased 5-methylcytosine and 5-hydroxymethylcytosine levels in the hippocampus that coincided with increased levels of the DNA methylating enzymes DNMT3a, TET1 and TET3. By inhibiting methylation using 5-iodotubercidin, we demonstrated amelioration of the epigenetic effects of irradiation. In addition to protecting against those molecular effects of irradiation, 5-iodotubercidin restored behavioral performance to that of unirradiated animals. The findings of this study establish the possibility that neuroepigenetic mechanisms significantly contribute to the functional and structural changes that affect the irradiated brain and cognition. PMID:28220892

  17. Pharmacological Protection From Radiation {+-} Cisplatin-Induced Oral Mucositis

    SciTech Connect

    Cotrim, Ana P.; Yoshikawa, Masanobu; Sunshine, Abraham N.; Zheng Changyu; Sowers, Anastasia L.; Thetford, Angela D.; Cook, John A.; Mitchell, James B.; Baum, Bruce J.

    2012-07-15

    Purpose: To evaluate if two pharmacological agents, Tempol and D-methionine (D-met), are able to prevent oral mucositis in mice after exposure to ionizing radiation {+-} cisplatin. Methods and Materials: Female C3H mice, {approx}8 weeks old, were irradiated with five fractionated doses {+-} cisplatin to induce oral mucositis (lingual ulcers). Just before irradiation and chemotherapy, mice were treated, either alone or in combination, with different doses of Tempol (by intraperitoneal [ip] injection or topically, as an oral gel) and D-met (by gavage). Thereafter, mice were sacrificed and tongues were harvested and stained with a solution of Toluidine Blue. Ulcer size and tongue epithelial thickness were measured. Results: Significant lingual ulcers resulted from 5 Multiplication-Sign 8 Gy radiation fractions, which were enhanced with cisplatin treatment. D-met provided stereospecific partial protection from lingual ulceration after radiation. Tempol, via both routes of administration, provided nearly complete protection from lingual ulceration. D-met plus a suboptimal ip dose of Tempol also provided complete protection. Conclusions: Two fairly simple pharmacological treatments were able to markedly reduce chemoradiation-induced oral mucositis in mice. This proof of concept study suggests that Tempol, alone or in combination with D-met, may be a useful and convenient way to prevent the severe oral mucositis that results from head-and-neck cancer therapy.

  18. Pharmacological protection from radiation ± Cisplatin - induced oral mucositis

    PubMed Central

    Cotrim, Ana P.; Yoshikawa, Masanobu; Sunshine, Abraham N.; Zheng, Changyu; Sowers, Anastasia L.; Thetford, Angela D.; Cook, John A.; Mitchell, James B.; Baum, Bruce J.

    2011-01-01

    Purpose To evaluate if two pharmacological agents, Tempol and D-methionine (D-met), are able to prevent oral mucositis in mice following exposure to ionizing radiation ± Cisplatin. Methods and Materials Female C3H mice, ~8 weeks old, were irradiated with five fractionated doses ± Cisplatin to induce oral mucositis (lingual ulcers). Just prior to irradiation and chemotherapy, mice were treated, either alone or in combination, with different doses of Tempol (by intraperitoneal, ip, injection or topically, as an oral gel) and D-met (by gavage). Thereafter, mice were sacrificed, tongues harvested and stained with a solution of Toluidine Blue. Ulcer size and tongue epithelial thickness were measured. Results Significant lingual ulcers resulted from 5 × 8 Gy radiation fractions, which were enhanced with Cisplatin treatment. D-met provided stereospecific partial protection from lingual ulceration after radiation. Tempol, via both routes of administration, provided nearly complete protection from lingual ulceration. D-met plus a suboptimal ip dose of Tempol also provided complete protection. Conclusions Two fairly simple pharmacological treatments were able to markedly reduce chemoradiation-induced oral mucositis in mice. This proof of concept study suggests that Tempol, alone or in combination with D-met, may be a useful and convenient way to prevent the severe oral mucositis that results from head and neck cancer therapy. PMID:22197226

  19. [Radiation-induced genomic instability: phenomenon, molecular mechanisms, pathogenetic significance].

    PubMed

    Mazurik, V K; Mikhaĭlov, V F

    2001-01-01

    The recent data on the radiation-induced genome instability as a special state of progeny of cells irradiated in vitro as well as after a whole body exposure to ionizing radiation, that make these cells considerably different from normal, unirradiated cells, were considered. This state presents a number of cytogenetical, molecular-biological, cytological and biochemical manifestations untypical for normal cells. The state is controlled by the mechanisms of regulation of checkpoints of cell cycle, and apoptosis, that is under gene p53 control. The proof has been found that this state transfers from irradiated maternal cells to their surviving progeny by the epigenetical mechanisms and would exist until the cells restore the original state of response on the DNA damage. From the point of view of the genome instability conception, that considers the chromatine rearrangement as the adaptive-evolution mechanism of adaptation of the species to changeable environmental conditions, the radiation-induced genome instability may be considered as transition of irradiated progeny to the state of read these to adaptation changes with two alternative pathways. The first leads to adaptation to enviromental conditions and restoring of normal cell functions. The second presents the cell transition into the transformed state with remain genome instability and with increase of tumour growth probability.

  20. [Sterilization and eugenics].

    PubMed

    Shasha, Shaul M

    2011-04-01

    The term "eugenics" was coined by Francis Galton in 1883 and was defined as the science of the improvement of the human race by better breeding. "Positive eugenics" referred to methods of encouraging the "most fit" to reproduce more often, while "negative eugenics" was related to ways of discouraging or preventing the "less fit" from reproducing by birth control and sterilization. Many western countries adopted eugenics programs including Britain, Canada, Norway, Australia, Switzerland and others. In Sweden more then 62,000 "unfits" were forcibly sterilized. Many states in the U.S.A. had adopted marriage laws with eugenics criteria including forced sterilization. Approximately 64,000 individuals were sterilized. Eugenics considerations also lay behind the adoption of the Immigration Restriction Act of 1924. The Largest plan on eugenics was adopted by the Nazi regime in Germany. Hundreds of thousands of people, who were viewed as being "unfit", were forcibly sterilized by different methods: Surgical sterilization or castration with severe complications and high mortality rates. X-ray irradiation. The method was suggested by Brack, and tested by Schuman using prisoners in Block No. 10 in Auschwitz and Birkenau. Experiments were also performed by Brack on prisoners using the "window method". "Klauberg method"--injection of irritating materials into the uterus. Experiments were conducted using the plant Caladium Seguinum which was believed to have sterilization and castration properties.

  1. Alectinib induced CNS radiation necrosis in an ALK+NSCLC patient with a remote (7 years) history of brain radiation.

    PubMed

    Ou, Sai-Hong Ignatius; Weitz, Michael; Jalas, John R; Kelly, Daniel F; Wong, Vanessa; Azada, Michele C; Quines, Oliver; Klempner, Samuel J

    2016-06-01

    Alectinib is a second generation ALK inhibitor that has significant clinical activity in central nervous system (CNS) metastases in anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). Pseudoprogression (PsP) due to radiation necrosis during alecitnib treatment of central nervous system (CNS) metastases from ALK-rearranged NSCLC as been reported. Hence, distinguishing radiation-related PsP from alectinib-induced radiographic changes is important to avoid erroneous early trial discontinuation and abandonment of an effective treatment. However, it remains difficult to assess casuality of radiation necrosis is related to recent direct radiation or induced by alectinib treatment or both. It is also unknown how long from previous radiation can alectinib still induce radiation necrosis. Here we reported a crizotinib-refractory ALK-positive NSCLC patient who develop radiation necrosis in one of his metastatic CNS lesions after approximately 12 months of alectinib treatment who otherwise had on-going CNS response on alectinib. His most recent radiation to his CNS metastases was 7 years prior to the start of alectinib. This case illustrates that in the setting of pror CNS radiation, given the significant clinical activity of alectinib in CNS metastases in ALK-positive NSCLC patients the risk of CNS radiation necrosis remains long after previous radiation to the CNS metastases has been completed and can occur after durable response of treatment.

  2. white anther: A Petunia Mutant That Abolishes Pollen Flavonol Accumulation, Induces Male Sterility, and Is Complemented by a Chalcone Synthase Transgene1

    PubMed Central

    Napoli, Carolyn A.; Fahy, Deirdre; Wang, Huai-Yu; Taylor, Loverine P.

    1999-01-01

    A mutation in an inbred line of petunia (Petunia hybrida) produces a reduction in the deep-purple corolla pigmentation and changes the anther color from yellow to white. In addition, the mutant, designated white anther (wha), is functionally male sterile. The inability of pollen from wha plants to germinate in vitro provides a physiological basis for the lack of seed set observed in self-crosses of the mutant. Biochemical complementation with nanomolar amounts of kaempferol, a flavonol aglycone, confirms that the inability of the wha pollen to germinate is due to a lack of this essential compound. Transgenic complementation with a functional ChsA (Chalcone synthase A) cDNA suggests that the genetic lesion responsible for the wha phenotype is in Chs, the gene for the first enzyme in the flavonol biosynthesis pathway. The genetic background of the parental line, as well as the pollen phenotype, allowed us to deduce that the wha mutation is in ChsA. To our knowledge, wha is the first induced, nontransgenic Chs mutant described in petunia, and analysis of the mutation confirms earlier molecular and genetic observations that only two Chs genes (A and J) are expressed in reproductive tissues and that they are differentially regulated in corolla and anther. PMID:10364414

  3. white anther: A petunia mutant that abolishes pollen flavonol accumulation, induces male sterility, and is complemented by a chalcone synthase transgene

    PubMed

    Napoli; Fahy; Wang; Taylor

    1999-06-01

    A mutation in an inbred line of petunia (Petunia hybrida) produces a reduction in the deep-purple corolla pigmentation and changes the anther color from yellow to white. In addition, the mutant, designated white anther (wha), is functionally male sterile. The inability of pollen from wha plants to germinate in vitro provides a physiological basis for the lack of seed set observed in self-crosses of the mutant. Biochemical complementation with nanomolar amounts of kaempferol, a flavonol aglycone, confirms that the inability of the wha pollen to germinate is due to a lack of this essential compound. Transgenic complementation with a functional ChsA (Chalcone synthase A) cDNA suggests that the genetic lesion responsible for the wha phenotype is in Chs, the gene for the first enzyme in the flavonol biosynthesis pathway. The genetic background of the parental line, as well as the pollen phenotype, allowed us to deduce that the wha mutation is in ChsA. To our knowledge, wha is the first induced, nontransgenic Chs mutant described in petunia, and analysis of the mutation confirms earlier molecular and genetic observations that only two Chs genes (A and J) are expressed in reproductive tissues and that they are differentially regulated in corolla and anther.

  4. Connecting radiation-induced bystander effects and senescence to improve radiation response prediction.

    PubMed

    Poleszczuk, Jan; Krzywon, Aleksandra; Forys, Urszula; Widel, Maria

    2015-05-01

    For the last two decades radiation-induced bystander effects (RIBEs) have attracted significant attention due to their possible implications for radiotherapy. However, despite extensive research, the molecular pathways associated with RIBEs are still not completely known. In the current study we investigated the role of senescence in the bystander response. Irradiated (2, 4, 6 and 8 Gy) human colorectal carcinoma cells (HCT116) with p53(+/+) (wild-type) or p53(-/-) (knockout) gene were co-incubated with nonirradiated cells of the same type. Clonogenic and senescence assays were used for both irradiated and co-incubated bystander cell populations. We also performed additional measurements on the number of remaining cells after the whole co-incubation period. For radiation doses larger than 2 Gy we observed much larger fractions of senescent cells in p53-positive populations compared to their p53-negative counterparts (15.81% vs. 3.63% in the irradiated population; 2.89% vs. 1.05% in the bystander population; 8 Gy; P < 0.05). Statistically significant differences between cell lines in the clonogenic cell surviving fraction were observed for doses higher than 4 Gy (1.61% for p53(+/+) vs. 0.19% for p53(-/-) in irradiated population; 3.57% for +/+ vs. 50.39% for -/- in bystander population; 8 Gy; P < 0.05). Our main finding was that the number of senescent cells in the irradiated population correlated strongly with the clonogenic cell surviving fraction (R = -0.98, P < 0.001) and the number of senescent cells (R = 0.97, P < 0.001) in the bystander population. We also extended the standard linear-quadratic radiation response model by incorporating the influence of the signals released by the senescent cells, which accurately described the radiation response in the bystander population. Our findings suggest that radiation-induced senescence might be a key player in RIBE, i.e., the strength of RIBE depends on the amount of radiation-induced senescence.

  5. Evaluation of the Contribution of Multiple DAMPs and DAMP Receptors in Cell Death-Induced Sterile Inflammatory Responses

    PubMed Central

    Patel, Zubin; Rock, Kenneth L.

    2014-01-01

    When cells die by necrosis in vivo they stimulate an inflammatory response. It is thought that this response is triggered when the injured cells expose proinflammatory molecules, collectively referred to as damage associated molecular patterns (DAMPs), which are recognized by cells or soluble molecules of the innate or adaptive immune system. Several putative DAMPs and/or their receptors have been identified, but whether and how much they participate in responses in vivo is incompletely understood, and they have not previously been compared side-by-side in the same models. This study focuses on evaluating the contribution of multiple mechanisms that have been proposed to or potentially could participate in cell death-induced inflammation: The third component of complement (C3), ATP (and its receptor P2X7), antibodies, the C-type lectin receptor Mincle (Clec4e), and protease-activated receptor 2 (PAR2). We investigate the role of these factors in cell death-induced inflammation to dead cells in the peritoneum and acetaminophen-induced liver damage. We find that mice deficient in antibody, C3 or PAR2 have impaired inflammatory responses to dying cells. In contrast there was no reduction in inflammation to cell death in the peritoneum or liver of mice that genetically lack Mincle, the P2X7 receptor or that were treated with apyrase to deplete ATP. These results indicate that antibody, complement and PAR2 contribute to cell death-induced inflammation but that Mincle and ATP- P2X7 receptor are not required for this response in at least 2 different in vivo models. PMID:25127469

  6. ER stress induced by ionising radiation in IEC-6 cells.

    PubMed

    Zhang, Bo; Wang, Yan; Pang, Xueli; Su, Yongping; Ai, Guoping; Wang, Tao

    2010-06-01

    Ionising radiation (IR) can evoke a series of biochemical events inside the cell. However, whether IR can directly induce endoplasmic reticulum (ER) stress is not clear. In our previous study, we found that there might be a causative link between IR and ER stress. In this study, we further characterised the type of ER stress induced by IR. Rat intestinal epithelial cells IEC-6 were irradiated at a dose of 10 Gy, and total RNA and proteins were harvested at indicated time points. The mRNA and protein expression of immunoglobulin heavy chain binding protein (BiP) and glucose regulated protein 94 (GRP94) was detected along with proteins associated with ER stress signal pathways. Our results indicated that IR induced up-regulation of ER stress marker including BiP and GRP94 at protein and mRNA levels in IEC-6 cells. Increased phosphorylation of eukaryotic translation initiation factor 2 (eIF2alpha) and induced mRNA splicing of X-box binding protein 1 (XBP1) suggested that PERK (interferon-induced double-stranded RNA-activated protein kinase (PRKR) -like endoplasmic reticulum kinase) and IRE1 (inositol requirement 1) signal transduction pathways were involved in this kind of ER stress. However, the active form of activating transcription factor 6 (ATF6) did not change significantly in irradiated cells, which suggested that the ATF6 pathway was not involved. Thus, we concluded that IR could induce moderate ER stress directly in IEC-6 cells.

  7. Plasma-Aided Sterilization*

    NASA Astrophysics Data System (ADS)

    Laroussi, Mounir; Rader, Mark; Dyer, Fred; Dever, Maureen; Alexeff, Igor

    1996-11-01

    The use of plasma as a sterilization agent was known for some time.In this paper we present recent work using atmospheric pressure plasmas to sterilize liquid and solid matter: The plasma can be a glow discharge or a corona discharge. The results show that sterilization occurs with treatment times which vary from a few seconds to a few minutes. The forseen applications of this method are in the medical, pharmaceutical, and food packaging industry. *Work supported in part by The Air Force Office of Scientific Research.

  8. Changes induced by UV radiation during virgin olive oil storage.

    PubMed

    Luna, G; Morales, M T; Aparicio, R

    2006-06-28

    The effects of UV radiation on the chemical and sensory characteristics of virgin olive oils (cv. Arbequina and Picual) were assessed. Even small doses of UV radiation induced oxidation of the virgin olive oil samples. Total phenols and fatty acids contents decreased during the process as well as the intensity of the bitter and fruity sensory attributes, while the intensity of the rancid sensory attribute notably increased. Acetaldehyde, 2-butenal, 2-pentenal, octane, octanal, hexanal, nonanal, and 2-decenal were the volatile compounds most affected, showing an important increase during the irradiation process. Nonanal, hexanal, and pentanal showed high correlation with the rancid sensory attribute (90%, 86%, and 86%, respectively). 2-Decenal and nonanal concentrations allowed us to predict the alteration level of the samples by mean of multiple Ridge regression.

  9. Radiation-induced cerebral meningioma: a recognizable entity.

    PubMed

    Rubinstein, A B; Shalit, M N; Cohen, M L; Zandbank, U; Reichenthal, E

    1984-11-01

    The authors retrospectively analyzed the clinical and histopathological findings in 201 patients with intracranial meningiomas operated on in the period 1978 to 1982. Forty-three of the patients (21.4%) had at some previous time received radiation treatment to their scalp, the majority for tinea capitis. The findings in these 43 irradiated patients were compared with those in the 158 non-irradiated patients. Several distinctive clinical and histological features were identified in the irradiated group, which suggest that radiation-induced meningiomas can be defined as a separate nosological subgroup. The use of irradiation in large numbers of children with tinea capitis in the era prior to the availability of griseofulvin may be responsible for a significantly increased incidence of intracranial meningiomas.

  10. Tissue deformation induced by radiation force from Gaussian transducers.

    PubMed

    Myers, Matthew R

    2006-05-01

    Imaging techniques based upon the tissue mechanical response to an acoustic radiation force are being actively researched. In this paper a model for predicting steady-state tissue displacement induced by a radiation force arising from the absorption of Gaussian ultrasound beams is presented. A simple analytic expression is derived that agrees closely with the numerical quadrature of the displacement convolution integrals. The analytic result reveals the dependence of the steady-state axial displacement upon the operational parameters, e.g., an inverse proportional relationship to the tissue shear modulus. The derivation requires that the transducer radius be small compared to the focal length, but accurate results were obtained for transducer radii comparable to the focal length. Favorable comparisons with displacement predictions for non-Gaussian transducers indicate that the theory is also useful for a broader range of transducer intensity profiles.

  11. Modification of microcrystalline cellulose by gamma radiation-induced grafting

    NASA Astrophysics Data System (ADS)

    Madrid, Jordan F.; Abad, Lucille V.

    2015-10-01

    Modified microcrystalline cellulose (MCC) was prepared through gamma radiation-induced graft polymerization of glycidyl methacrylate (GMA). Simultaneous grafting was employed wherein MCC with GMA in methanol was irradiated with gamma radiation in nitrogen atmosphere. The effects of different experimental factors such as monomer concentration, type of solvent and absorbed dose on the degree of grafting, Dg, were studied. The amount of grafted GMA, expressed as Dg, was determined gravimetrically. Information from grafted samples subjected to Fourier transformed infrared spectroscopy (FTIR) in attenuated total reflectance (ATR) mode showed peaks corresponding to GMA which indicates successful grafting. The X-ray diffraction (XRD) analysis revealed that the crystalline region of MCC was not adversely affected after grafting with GMA. The thermogravimetric analysis (TGA) data showed that the decomposition of grafted MCC occurred at higher temperature compared to the base MCC polymer.

  12. Treatment of radiation- and chemotherapy-induced stomatitis

    SciTech Connect

    Carnel, S.B.; Blakeslee, D.B.; Oswald, S.G.; Barnes, M. )

    1990-04-01

    Severe stomatitis is a common problem encountered during either radiation therapy or chemotherapy. Most therapeutic regimens are empirical, with no scientific basis. The purpose of this study is to determine the efficacy of various topical solutions in the treatment of radiation- or chemotherapy-induced stomatitis. Eighteen patients were entered into a prospective double-blinded study to test several topical solutions: (1) viscous lidocaine with 1% cocaine; (2) dyclonine hydrochloride 1.0% (Dyclone); (3) kaolin-pectin solution, diphenhydramine plus saline (KBS); and (4) a placebo solution. Degree of pain relief, duration of relief, side effects, and palatability were evaluated. The results showed that Dyclone provided the most pain relief. Dyclone and viscous lidocaine with 1% cocaine provided the longest pain relief, which averaged 50 minutes This study provides objective data and defines useful guidelines for treatment of stomatitis.

  13. Potential targets for intervention in radiation-induced heart disease.

    PubMed

    Boerma, M; Hauer-Jensen, M

    2010-11-01

    Radiotherapy of thoracic and chest wall tumors, if all or part of the heart was included in the radiation field, can lead to radiation-induced heart disease (RIHD), a late and potentially severe side effect. RIHD presents clinically several years after irradiation and manifestations include accelerated atherosclerosis, pericardial and myocardial fibrosis, conduction abnormalities, and injury to cardiac valves. The pathogenesis of RIHD is largely unknown, and a treatment is not available. Hence, ongoing pre-clinical studies aim to elucidate molecular and cellular mechanisms of RIHD. Here, an overview of recent pre-clinical studies is given, and based on the results of these studies, potential targets for intervention in RIHD are discussed.

  14. Genomic Instability Induced by High and Low Let Ionizing Radiation

    NASA Astrophysics Data System (ADS)

    Limoli, C. L.; Ponnaiya, B.; Corcoran, J. J.; Giedzinski, E.; Kaplan, M. I.; Hartmann, A.; Morgan, W. F.

    Genomic instability is the increased rate of acquisition of alterations in the mammalian genome, and includes such diverse biological endpoints as chromosomal destabilization, aneuploidy, micronucleus formation, sister chromatid exchange, gene mutation and amplification, variations in colony size, reduced plating efficiency, and cellular transformation. Because these multiple endpoints persist long after initial radiation exposure, genomic instability has been proposed to operate as a driving force contributing to genetic plasticity and carcinogenic potential. Many of these radiation-induced endpoints depend qualitatively and quantitatively on genetic background, dose and LET. Differences in the frequency and temporal expression of chromosomal instability depend on all three of the foregoing factors. On the other hand, many of these endpoints appear independent of dose and show bystander effects, implicating non-nuclear targets and epigenetic regulatory mechanisms. The present work will survey results concerning the LET dependence of genomic instability and the role of epigenetic mechanisms, with a particular emphasis on the endpoint of chromosomal in tability

  15. DNA Prime/Adenovirus Boost Malaria Vaccine Encoding P. falciparum CSP and AMA1 Induces Sterile Protection Associated with Cell-Mediated Immunity

    PubMed Central

    Chuang, Ilin; Sedegah, Martha; Cicatelli, Susan; Spring, Michele; Polhemus, Mark; Tamminga, Cindy; Patterson, Noelle; Guerrero, Melanie; Bennett, Jason W.; McGrath, Shannon; Ganeshan, Harini; Belmonte, Maria; Farooq, Fouzia; Abot, Esteban; Banania, Jo Glenna; Huang, Jun; Newcomer, Rhonda; Rein, Lisa; Litilit, Dianne; Richie, Nancy O.; Wood, Chloe; Murphy, Jittawadee; Sauerwein, Robert; Hermsen, Cornelus C.; McCoy, Andrea J.; Kamau, Edwin; Cummings, James; Komisar, Jack; Sutamihardja, Awalludin; Shi, Meng; Epstein, Judith E.; Maiolatesi, Santina; Tosh, Donna; Limbach, Keith; Angov, Evelina; Bergmann-Leitner, Elke; Bruder, Joseph T.; Doolan, Denise L.; King, C. Richter; Carucci, Daniel; Dutta, Sheetij; Soisson, Lorraine; Diggs, Carter; Hollingdale, Michael R.; Ockenhouse, Christian F.; Richie, Thomas L.

    2013-01-01

    Background Gene-based vaccination using prime/boost regimens protects animals and humans against malaria, inducing cell-mediated responses that in animal models target liver stage malaria parasites. We tested a DNA prime/adenovirus boost malaria vaccine in a Phase 1 clinical trial with controlled human malaria infection. Methodology/Principal Findings The vaccine regimen was three monthly doses of two DNA plasmids (DNA) followed four months later by a single boost with two non-replicating human serotype 5 adenovirus vectors (Ad). The constructs encoded genes expressing P. falciparum circumsporozoite protein (CSP) and apical membrane antigen-1 (AMA1). The regimen was safe and well-tolerated, with mostly mild adverse events that occurred at the site of injection. Only one AE (diarrhea), possibly related to immunization, was severe (Grade 3), preventing daily activities. Four weeks after the Ad boost, 15 study subjects were challenged with P. falciparum sporozoites by mosquito bite, and four (27%) were sterilely protected. Antibody responses by ELISA rose after Ad boost but were low (CSP geometric mean titer 210, range 44–817; AMA1 geometric mean micrograms/milliliter 11.9, range 1.5–102) and were not associated with protection. Ex vivo IFN-γ ELISpot responses after Ad boost were modest (CSP geometric mean spot forming cells/million peripheral blood mononuclear cells 86, range 13–408; AMA1 348, range 88–1270) and were highest in three protected subjects. ELISpot responses to AMA1 were significantly associated with protection (p = 0.019). Flow cytometry identified predominant IFN-γ mono-secreting CD8+ T cell responses in three protected subjects. No subjects with high pre-existing anti-Ad5 neutralizing antibodies were protected but the association was not statistically significant. Significance The DNA/Ad regimen provided the highest sterile immunity achieved against malaria following immunization with a gene-based subunit vaccine (27%). Protection was

  16. Radiation-Induced Lymphocyte Apoptosis to Predict Radiation Therapy Late Toxicity in Prostate Cancer Patients

    SciTech Connect

    Schnarr, Kara; Boreham, Douglas; Sathya, Jinka; Julian, Jim; Dayes, Ian S.

    2009-08-01

    Purpose: To examine a potential correlation between the in vitro apoptotic response of lymphocytes to radiation and the risk of developing late gastrointestinal (GI)/genitourinary (GU) toxicity from radiotherapy for prostate cancer. Methods and Materials: Prostate cancer patients formerly enrolled in a randomized study were tested for radiosensitivity by using a radiation-induced lymphocyte apoptosis assay. Apoptosis was measured using flow cytometry-based Annexin-FITC/7AAD and DiOC{sub 6}/7AAD assays in subpopulations of lymphocytes (total lymphocytes, CD4+, CD8+ and CD4-/CD8-) after exposure to an in vitro dose of 0, 2, 4, or 8 Gy. Results: Patients with late toxicity after radiotherapy showed lower lymphocyte apoptotic responses to 8 Gy than patients who had not developed late toxicity (p = 0.01). All patients with late toxicity had apoptosis levels that were at or below the group mean. The negative predictive value in both apoptosis assays ranged from 95% to 100%, with sensitivity values of 83% to 100%. Apoptosis at lower dose points and in lymphocyte subpopulations had a weaker correlation with the occurrence of late toxicity. Conclusions: Lymphocyte apoptosis after 8 Gy of radiation has the potential to predict which patients will be spared late toxicity after radiation therapy. Further research should be performed to identify the specific subset of lymphocytes that correlates with late toxicity, followed by a corresponding prospective study.

  17. Influence of radiation quality on mouse chromosome 2 deletions in radiation-induced acute myeloid leukaemia.

    PubMed

    Brown, Natalie; Finnon, Rosemary; Manning, Grainne; Bouffler, Simon; Badie, Christophe

    2015-11-01

    Leukaemia is the prevailing neoplastic disorder of the hematopoietic system. Epidemiological analyses of the survivors of the Japanese atomic bombings show that exposure to ionising radiation (IR) can cause leukaemia. Although a clear association between radiation exposure and leukaemia development is acknowledged, the underlying mechanisms remain incompletely understood. A hemizygous deletion on mouse chromosome 2 (del2) is a common feature in several mouse strains susceptible to radiation-induced acute myeloid leukaemia (rAML). The deletion is an early event detectable 24h after exposure in bone marrow cells. Ultimately, 15-25% of exposed animals develop AML with 80-90% of cases carrying del2. Molecular mapping of leukaemic cell genomes identified a minimal deleted region (MDR) on chromosome 2 (chr2) in which a tumour suppressor gene, Sfpi1 is located, encoding the transcription factor PU.1, essential in haematopoiesis. The remaining copy of Sfpi1 has a point mutation in the coding sequence for the DNA-binding domain of the protein in 70% of rAML, which alters a single CpG sequence in the codon for arginine residue R235. In order to identify chr2 deletions and Sfpi.1/PU.1 loss, we performed array comparative genomic hybridization (aCGH) on a unique panel of 79rAMLs. Using a custom made CGH array specifically designed for mouse chr2, we analysed at unprecedentedly high resolution (1.4M array- 148bp resolution) the size of the MDR in low LET and high-LET induced rAMLs (32 X-ray- and 47 neutron-induced). Sequencing of Sfpi1/PU.1DNA binding domain identified the presence of R235 point mutations, showing no influence of radiation quality on R235 type or frequency. We identified for the first time rAML cases with complex del2 in a subset of neutron-induced AMLs. This study allowed us to re-define the MDR to a much smaller 5.5Mb region (still including Sfpi1/PU.1), identical regardless of radiation quality. Crown Copyright © 2015. Published by Elsevier B.V. All rights

  18. Role of Oxidative Damage in Radiation-Induced Bone Loss

    NASA Technical Reports Server (NTRS)

    Schreurs, Ann-Sofie; Alwood, Joshua S.; Limoli, Charles L.; Globus, Ruth K.

    2014-01-01

    used an array of countermeasures (Antioxidant diets and injections) to prevent the radiation-induced bone loss, although these did not prevent bone loss, analysis is ongoing to determine if these countermeasure protected radiation-induced damage to other tissues.

  19. Radiation-Induced Phase Transformations in Ilmenite-Group Minerals

    SciTech Connect

    Mitchell, J. N.

    1997-12-31

    Transmission electron microscopy (TEM) is a powerful tool for characterizing and understanding radiation-induced structural changes in materials. We have irradiated single crystals of ilmenite (FeTiO{sub 3}) and geikielite (MgTiO{sub 3}) using ions and electrons to better understand the response of complex oxides to radiation. Ion irradiation experiments of bulk single crystals at 100 K show that ilmenite amorphized at doses of less than 1x10(exp15) Ar(2+)/sq cm and at a damage level in the peak damage region of 1 displacement per atom (dpa). Transmission electron microscopy and electron diffraction of a cross-sectioned portion of this crystal confirmed the formation of a 150 am thick amorphous layer. Geikielite proved to be more radiation resistant, requiring a flux of 2x10(exp 15) Xe(2+)/sq cm to induce amorphization at 100 K. This material did not amorphize at 470 K, despite a dose of 2.5 x10(exp 16) Xe(2+)/sq cm and a damage level as high as 25 dpa. Low temperature irradiations of electron- transparent crystals with 1 MeV Kr(+) also show that ilmenite amorphized after a damage level of 2.25 dpa at 175 K.Similar experiments on geikielite show that the microstructure is partially amorphous and partially crystalline after 10 dpa at 150 K. Concurrent ion and electron irradiation of both materials with 1 MeV Kr(+) and 0.9 MeV electrons produced dislocation loops in both materials, but no amorphous regions were formed. Differences in the radiation response of these isostructural oxides suggests that in systems with Mg-Fe solid solution, the Mg-rich compositions may be more resistant to structural changes.

  20. [Radiation-induced cancers: state of the art in 1997].

    PubMed

    Cosset, J M

    1997-01-01

    Scientists now have available a large amount of data dealing with radiation-induced neoplasms. These data went back to anecdotal observations which were made in the very first years of utilization of X-rays and radioactive elements. In fact, it is essentially the strict follow-up of the Japanese populations irradiated by the Hiroshima and Nagasaki bombing which allowed a more precise evaluation of the carcinogenicity of ionizing radiations. Further refinements came from therapeutical irradiations: it is now possible to study large cohorts of patients given well-known doses in well-defined volumes and followed for more than 20 years. Last but not least, a significant increase in the incidence and mortality of thyroid cancer has been detected in children contaminated by iodine radioisotopes after the Tchernobyl accident. Recently, some data suggested the emergence of "clusters" of leukemias close to some nuclear facilities, but this question remains highly polemical, both in France and in the UK. Other questions are still waiting for a precise answer; of course, the extrapolation of our available data to very low doses delivered at very low dose rates, but also the carcinogenic risk at high doses. For these "high" doses (about 30 to 70 Gy), a competition between mutagenesis and cell killing was expected, so that these dose levels were expected to be less carcinogenic than lower (a few sieverts) doses. Actually, recent data suggest that the carcinogenic risk goes on increasing up to relatively important doses. In addition, carcinogenic factors, such as tabacco, anticancer chemotherapy and individual susceptibility, are found more and more to be closely intricated with ionizing radiation in the genesis of a given cancer. Even if a number of questions are still pending, the already available data allow specialists, both in medicine and radioprotection, to edict strict rules which can be reasonably expected to have significantly reduced the risk of radiation-induced

  1. Biological Sterilization of Returned Mars Samples

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Albert, F. G.; Combie, J.; Bodnar, R. J.; Hamilton, V. E.; Jolliff, B. L.; Kuebler, K.; Wang, A.; Lindstrom, D. J.; Morris, P. A.

    1999-01-01

    Martian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.

  2. Biological Sterilization of Returned Mars Samples

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Albert, F. G.; Combie, J.; Bodnar, R. J.; Hamilton, V. E.; Jolliff, B. L.; Kuebler, K.; Wang, A.; Lindstrom, D. J.; Morris, P. A.

    1999-01-01

    Martian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.

  3. Nocifensive Behaviors in Mice with Radiation-Induced Oral Mucositis.

    PubMed

    Nolan, Michael W; Long, C Tyler; Marcus, Karen L; Sarmadi, Shayan; Roback, Donald M; Fukuyama, Tomoki; Baeumer, Wolfgang; Lascelles, B Duncan X

    2017-02-10

    Oral mucositis can result in significant dysphagia, and is the most common dose-limiting acute toxicity in head and neck cancer patients receiving chemoradiotherapy. There is a critical need to determine the cellular and molecular mechanisms that underlie radiotherapy-associated discomfort in patients with mucositis. The objective was to induce oral mucositis in mice, using a clinical linear accelerator, and to quantify resultant discomfort, and characterize peripheral sensitization. A clinical linear accelerator was used to deliver ionizing radiation to the oral cavity of mice. Mucositis severity scoring, and various behavioral assays were performed to quantify bouts of orofacial wiping and scratching, bite force, gnawing behavior and burrowing activity. Calcium imaging was performed on neurons of the trigeminal ganglia. Glossitis was induced with a single fraction of at least 27 Gy. Body weight decreased and subsequently returned to baseline, in concert with development and resolution of mucositis, which was worst at day 10 and 11 postirradiation, however was resolved within another 10 days. Neither bite force, nor gnawing behavior were measurably affected. However, burrowing activity was decreased, and both facial wiping and scratching were increased while mice had visible mucositis lesions. Sensory nerves of irradiated mice were more responsive to histamine, tumor necrosis factor alpha and capsaicin. Radiation-induced glossitis is associated with hyper-reactivity of sensory neurons in the trigeminal ganglia of mice, and is accompanied by several behaviors indicative of both itch and pain. These data validate an appropriate model for cancer treatment related discomfort in humans.

  4. DNA damage in cells exhibiting radiation-induced genomic instability

    SciTech Connect

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesis that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.

  5. DNA damage in cells exhibiting radiation-induced genomic instability

    DOE PAGES

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesismore » that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.« less

  6. Galactic cosmic ray-induced radiation dose on terrestrial exoplanets.

    PubMed

    Atri, Dimitra; Hariharan, B; Grießmeier, Jean-Mathias

    2013-10-01

    This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground- and space-based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets that reside in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Planetary systems around M dwarfs are considered to be prime candidates to search for life beyond the Solar System. Such planets are likely to be tidally locked and have close-in habitable zones. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in the case of super-Earths. Such exoplanets are subjected to a high flux of galactic cosmic rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin that strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another factor governing the radiation dose is the depth of the planetary atmosphere. The higher the depth of the planetary atmosphere, the lower the flux of secondary particles will be on the surface. If the secondary particles are energetic enough, and their flux is sufficiently high, the radiation from muons can also impact the subsurface regions, such as in the case of Mars. If the radiation dose is too high, the chances of sustaining a long-term biosphere on the planet are very low. We have examined the dependence of the GCR-induced radiation dose on the strength of the planetary magnetic field and its atmospheric depth, and found that the latter is the decisive factor for the protection of a planetary biosphere.

  7. [Radiation induced lung injuries secondary to radiotherapy for breast cancer].

    PubMed

    Toma, Claudia Lucia; Ciprut, Tudor; Bugarin, Svetlana; Roşca, Dorina; Bogdan, Miron Alexandru

    2011-01-01

    Modern radiotherapy decreased the number and severity of the effects of irradiation on the lung. Yet, the increased cancer incidence makes the related radiation injuries to remain actual, radiotherapy being frequently used in cancer treatment. Aim of the study consists in analysis of the radiological pattern of radiation induced lung disease due to radiotherapy for breast cancer. Sixty-eight female patients were evaluated for clinical and radiological suspicion of radiation pneumonitis after radiotherapy for breast cancer between 2001 and 2009 in "Marius Nasta" Institute of Pneumophtiziology, Bucharest. The following procedures were performed: medical history, physical examination, chest radiography and CT-scan (in a subgroup of 27 patients). Radiotherapy toxicity was evaluated based on the RTOG/EORTC (Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer) classification and radiological lesions based on Arriagada classification. Fifty patients (73.5%) were symptomatic (fever, dry cough, dyspnea, chest pain, fatigability), the other 18 were asymptomatic. Symptoms were mild to moderate corresponding to grade 1 (27 patients, 39.7%) or grade 2 (23 patients, 33.8%) according to RTOG/EORTC scale. All patients had radiological lesions: 25 patients (36.7%) had grade 2 lesions (linear opacities), 25 patients (36.7%) had grade 3 lesions (patchy opacities) and 18 patients (26.5%) had grade 4 lesions (dense opacities), according to Arriagada classification. Symptoms were more frequent in patients with extensive lesions on chest radiography. CT-scan, performed in 27 patients, showed more accurate images. Chest radiography remains the simplest method in screening for radiation pneumonitis and monitoring its outcome. Adverse effects secondary to radiotherapy are usually mild and self-limited, and the most difficult task remains the differential diagnosis with infections and cancer relapse.

  8. Inhibition of radiation-induced skin fibrosis with imatinib.

    PubMed

    Horton, Jason A; Chung, Eun Joo; Hudak, Kathryn E; Sowers, Anastasia; Thetford, Angela; White, Ayla O; Mitchell, James B; Citrin, Deborah E

    2013-03-01

    Dermal fibrosis is a disabling late toxicity of radiotherapy. Several lines of evidence suggest that overactive signaling via the Platelet-derived growth factor receptor-beta (PDGFR-β) and V-abl Abelson murine leukemia viral oncogene homolog 1 (cAbl) may be etiologic factors in the development of radiation-induced fibrosis. We tested the hypothesis that imatinib, a clinically available inhibitor of PDGFR-β, Mast/stem cell growth factor receptor (c-kit) and cAbl, would reduce the severity of dermal fibrosis in a murine model. The right hind legs of female C3H/HeN mice were exposed to 35 Gy of X-rays. Cohorts of mice were maintained on chow formulated with imatinib 0.5 mg/g or control chow for the duration of the experiment. Bilateral hind limb extension was measured serially to assess fibrotic contracture. Immunohistochemistry and biochemical assays were used to evaluate the levels of collagen and cytokines implicated in radiation-induced fibrosis. Imatinib treatment significantly reduced hind limb contracture and dermal thickness after irradiation. Immunohistochemical studies demonstrated a substantial reduction in PDGFR-β phosphorylation. We also observed reduced Transforming Growth factor-β (TGF-β) and collagen expression in irradiated skin of imatinib-treated mice, suggesting that imatinib may suppress the fibrotic process by interrupting cross-talk between these pathways. Taken together, these results support that imatinib may be a useful agent in the prevention and treatment of radiation-induced dermal fibrosis.

  9. Erythrocyte Stiffness during Morphological Remodeling Induced by Carbon Ion Radiation

    PubMed Central

    Zhang, Baoping; Liu, Bin; Zhang, Hong; Wang, Jizeng

    2014-01-01

    The adverse effect induced by carbon ion radiation (CIR) is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy) or X-rays (2, 4, 6, and 12 Gy) for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-α1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy). The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-α1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study provides a new

  10. Lack of photoprotection against UVB-induced erythema by immediate pigmentation induced by 382 nm radiation

    SciTech Connect

    Black, G.; Matzinger, E.; Gange, R.W.

    1985-11-01

    Immediate pigment darkening (IPD) was induced on the backs of 11 human volunteers of skin types III and IV by exposing the skin to UVA radiation (382 nm). The minimum erythema dose (MED) of UVB radiation was also determined by exposing sites to graduated doses of 304 nm radiation. The order of exposure of distinct anatomic areas was as follow: UVB followed by IPD induction; IPD induction followed by UVB; IPD induction followed 3 h later by UVB; and UVB only. Erythema responses induced by UVB were graded by inspection 24 h later and the MEDs in the 4 areas were compared. The induction of IPD before UVB exposure caused no significant change in the MED compared to sites receiving UVB only, or receiving UVA radiation after UVB, confirming that the IPD reaction does not protect against UVB-induced erythema. There was also no evidence of photorecovery, i.e., an increase in the MED of UVB resulting from exposure to longer wavelength, UV or visible radiation following UVB exposure.

  11. Sterilization of space hardware.

    NASA Technical Reports Server (NTRS)

    Pflug, I. J.

    1971-01-01

    Discussion of various techniques of sterilization of space flight hardware using either destructive heating or the action of chemicals. Factors considered in the dry-heat destruction of microorganisms include the effects of microbial water content, temperature, the physicochemical properties of the microorganism and adjacent support, and nature of the surrounding gas atmosphere. Dry-heat destruction rates of microorganisms on the surface, between mated surface areas, or buried in the solid material of space vehicle hardware are reviewed, along with alternative dry-heat sterilization cycles, thermodynamic considerations, and considerations of final sterilization-process design. Discussed sterilization chemicals include ethylene oxide, formaldehyde, methyl bromide, dimethyl sulfoxide, peracetic acid, and beta-propiolactone.

  12. Sterilization of space hardware.

    NASA Technical Reports Server (NTRS)

    Pflug, I. J.

    1971-01-01

    Discussion of various techniques of sterilization of space flight hardware using either destructive heating or the action of chemicals. Factors considered in the dry-heat destruction of microorganisms include the effects of microbial water content, temperature, the physicochemical properties of the microorganism and adjacent support, and nature of the surrounding gas atmosphere. Dry-heat destruction rates of microorganisms on the surface, between mated surface areas, or buried in the solid material of space vehicle hardware are reviewed, along with alternative dry-heat sterilization cycles, thermodynamic considerations, and considerations of final sterilization-process design. Discussed sterilization chemicals include ethylene oxide, formaldehyde, methyl bromide, dimethyl sulfoxide, peracetic acid, and beta-propiolactone.

  13. Female Sterilization (Tubal Ligation)

    MedlinePlus

    ... when you want to have it done. Some women are sterilized right after they have a baby or an abortion, ... videos on Youtube © 1998-2017 | Center for Young Women's Health, Boston Children's Hospital. All rights reserved.

  14. Measurements of prompt radiation induced conductivity of Kapton.

    SciTech Connect

    Preston, Eric F.; Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  15. Radiation-Induced Premelting of Ice at Silica Interfaces

    SciTech Connect

    Schoeder, S.; Reichert, H.; Schroeder, H.; Mezger, M.; Okasinski, J. S.; Dosch, H.; Honkimaeki, V.; Bilgram, J.

    2009-08-28

    The existence of surface and interfacial melting of ice below 0 deg. C has been confirmed by many different experimental techniques. Here we present a high-energy x-ray reflectivity study of the interfacial melting of ice as a function of both temperature and x-ray irradiation dose. We found a clear increase of the thickness of the quasiliquid layer with the irradiation dose. By a systematic x-ray study, we have been able to unambiguously disentangle thermal and radiation-induced premelting phenomena. We also confirm the previously announced very high water density (1.25 g/cm{sup 3}) within the emerging quasiliquid layer.

  16. A model of radiatively induced quark and lepton mass model

    NASA Astrophysics Data System (ADS)

    Nomura, Takaaki

    2017-07-01

    We discuss a radiatively induced quark and lepton mass model in the rst and second generation introducing extra U(1) gauge symmetry, discrete Z 2 symmetry, vector-like fermions and exotic scalar elds. Then we analyze the allowed parameter regions which simultaneously satisfy the constraints of FCNCs for the quark sector and of LFVs including μ - e conversion, observed quark mass and mixing, and the lepton mass and mixing. In addition, the typical value for the (g - 2) μ in our model is presented. We also show extension of the model in which Majorana type neutrino masses are generated at the two loop level.

  17. Mechanisms of Radiation Induced Effects in Carbon Nanotubes

    DTIC Science & Technology

    2016-10-01

    kilogram ( C kg –1 ) rad [absorbed dose] 1 × 10 –2 joule per kilogram (J kg –1 ) [gray (Gy)] rem [equivalent and effective dose] 1 × 10–2 joule per...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-17-5 Mechanisms of Radiation-Induced...CLASSIFICATION OF: a. REPORT b. ABSTRACT c . THIS PAGE 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 00-10-2016 Final Oct 5, 2010 - Dec 31, 2015 Mechanisms of

  18. Measurements of prompt radiation induced conductivity in Teflon (PTFE).

    SciTech Connect

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, E.

    2013-05-01

    We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon.

  19. Radiation-Induced Premelting of Ice at Silica Interfaces

    NASA Astrophysics Data System (ADS)

    Schöder, S.; Reichert, H.; Schröder, H.; Mezger, M.; Okasinski, J. S.; Honkimäki, V.; Bilgram, J.; Dosch, H.

    2009-08-01

    The existence of surface and interfacial melting of ice below 0°C has been confirmed by many different experimental techniques. Here we present a high-energy x-ray reflectivity study of the interfacial melting of ice as a function of both temperature and x-ray irradiation dose. We found a clear increase of the thickness of the quasiliquid layer with the irradiation dose. By a systematic x-ray study, we have been able to unambiguously disentangle thermal and radiation-induced premelting phenomena. We also confirm the previously announced very high water density (1.25g/cm3) within the emerging quasiliquid layer.

  20. Facial reconstruction for radiation-induced skin cancer

    SciTech Connect

    Panje, W.R.; Dobleman, T.J. )

    1990-04-01

    Radiation-induced skin cancers can be difficult to diagnose and treat. Typically, a patient who has received orthovoltage radiotherapy for disorders such as acne, eczema, tinea capitis, skin tuberculosis, and skin cancer can expect that aggressive skin cancers and chronic radiodermatitis may develop subsequently. Cryptic facial cancers can lead to metastases and death. Prophylactic widefield excision of previously irradiated facial skin that has been subject to multiple recurrent skin cancers is suggested as a method of deterring future cutaneous malignancy and metastases. The use of tissue expanders and full-thickness skin grafts offers an expedient and successful method of subsequent reconstruction.