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Sample records for irradiation induced alteration

  1. Ultraviolet Irradiation-Induced Volume Alteration of Corneal Epithelial Cells

    PubMed Central

    Wang, Ling; Lu, Luo

    2016-01-01

    Purpose The purpose of the study is to understand how extracellular stresses, such as ultraviolet (UV) irradiation, affect corneal epithelial cells. Cell volume changes, damage to corneal epithelial integrity, and cellular responses were assessed after exposure to UVC stresses. Methods Primary human and rabbit corneal epithelial cells were exposed to UVC light in culture conditions. Ultraviolet C irradiation–induced changes in cell size and volume were measured by real-time microscopy and self-quenching of the fluorescent dye calcein, respectively. The effects of UVC irradiation on Src and focal adhesion kinase (FAK) phosphorylation and FAK-dependent integrin signaling were detected by ELISA, immunoblotting, and immunostaining. Results Ultraviolet C irradiation induced both size and volume shifts in human and rabbit corneal epithelial cells. Ultraviolet C irradiation-induced decrease of cell volume elicited activation of Src and FAK, characterized by increased phosphorylations of SrcY416, FAKY397, and FAKY925. In addition, immunostaining studies showed UVC irradiation–induced increases in phosphorylation of FAK and formation of integrin β5 clustering. Application of Kv channel blockers, including 4-aminopyridine (4-AP), α-DTX, and depressing substance-1 (BDS-1), effectively suppressed UVC irradiation–induced cell volume changes, and subsequently inhibited UVC irradiation–induced phosphorylation of Src/FAK, and formation of integrin β5 clustering, suggesting UVC irradiation–induced volume changes and Src/FAK activation. Hyperosmotic pressure–induced volume decreases were measured in comparison with effects of UVC irradiation on volume and Src/FAK activation. However, Kv channel blocker, 4-AP, had no effect on hyperosmotic pressure–induced responses. Conclusions The present study demonstrates that UVC irradiation–induced decreases in cell volume lead to Src/FAK activation due to a rapid loss of K ions through membrane Kv channels. PMID:27978555

  2. Radiation-Induced Epigenetic Alterations after Low and High LET Irradiations

    SciTech Connect

    Aypar, Umut; Morgan, William F.; Baulch, Janet E.

    2011-02-01

    Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding the delayed, non-targeted effects of radiation including radiationinduced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET x-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NFκB), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. MiRNA shown to be altered in expression level after x-ray irradiation are involved in chromatin remodeling and DNA methylation. Different and higher incidence of epigenetic changes were observed after exposure to low LET x-rays than high LET Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This study also shows that the irradiated cells acquire epigenetic changes even though they are chromosomally stable suggesting that epigenetic aberrations may arise in the cell without initiating RIGI.

  3. Altered gastric emptying and prevention of radiation-induced vomiting in dogs. [Cobalt 60 irradiation

    SciTech Connect

    Dubois, A.; Jacobus, J.P.; Grissom, M.P.; Eng, R.R.; Conklin, J.J.

    1984-03-01

    The relation between radiation-induced vomiting and gastric emptying is unclear and the treatment of this condition is not established. We explored, therefore, (a) the effect of cobalt 60 irradiation on gastric emptying of solids and liquids and (b) the possibility of preventing radiation-induced vomiting with the dopamine antagonist, domperidone. Twenty dogs were studied on two separate days, blindly and in random order, after i.v. injection of either a placebo or 0.06 mg/kg domperidone. On a third day, they received 8 Gy (800 rads) whole body irradiation with cobalt 60 gamma-rays after either placebo (n . 10) or domperidone (n . 10). Before each study, each dog was fed chicken liver tagged in vivo with 99mTc-sulfur colloid (solid marker), and water containing 111In-diethylenetriamine pentaacetic acid (liquid marker). Dogs were placed in a Pavlov stand for the subsequent 3 h and radionuclide imaging was performed at 10-min intervals. Irradiation produced vomiting in 9 of 10 dogs given placebo but only in 1 of 10 dogs pretreated with domperidone (p less than 0.01). Gastric emptying of liquids and solids was significantly suppressed by irradiation (p less than 0.01) after both placebo and domperidone. These results demonstrate that radiation-induced vomiting is accompanied by suppression of gastric emptying. Furthermore, domperidone prevents vomiting produced by ionizing radiation but does not alter the accompanying delay of gastric emptying.

  4. Trauma-induced alterations in cognition and Arc expression are reduced by previous exposure to 56Fe irradiation.

    PubMed

    Rosi, Susanna; Belarbi, Karim; Ferguson, Ryan A; Fishman, Kelly; Obenaus, Andre; Raber, Jacob; Fike, John R

    2012-03-01

    Exposure to ionizing irradiation may affect brain functions directly, but may also change tissue sensitivity to a secondary insult such as trauma, stroke, or degenerative disease. To determine if a low dose of particulate irradiation sensitizes the brain to a subsequent injury, C56BL6 mice were exposed to brain only irradiation with 0.5 Gy of (56) Fe ions. Two months later, unilateral traumatic brain injury was induced using a controlled cortical impact system. Three weeks after trauma, animals received multiple BrdU injections and 30 days later were tested for cognitive performance in the Morris water maze. All animals were able to locate the visible and hidden platform during training; however, treatment effects were seen when spatial memory retention was assessed in the probe trial (no platform). Although sham and irradiated animals showed spatial memory retention, mice that received trauma alone did not. When trauma was preceded by irradiation, performance in the water maze was not different from sham-treated animals, suggesting that low-dose irradiation had a protective effect in the context of a subsequent traumatic injury. Measures of hippocampal neurogenesis showed that combined injury did not induce any changes greater that those seen after trauma or radiation alone. After trauma, there was a significant decrease in the percentage of neurons expressing the behaviorally induced immediate early gene Arc in both hemispheres, without associated neuronal loss. After combined injury there were no differences relative to sham-treated mice. Our results suggest that combined injury resulted in decreased alterations of our endpoints compared to trauma alone. Although the underlying mechanisms are not yet known, these results resemble a preconditioning, adaptive, or inducible-like protective response, where a sublethal or potentially injurious stimulus (i.e., irradiation) induces tolerance to a subsequent and potentially more damaging insult (trauma).

  5. Optical alteration of complex organics induced by ion irradiation:. 1. Laboratory experiments suggest unusual space weathering trend

    NASA Astrophysics Data System (ADS)

    Moroz, Lyuba; Baratta, Giuseppe; Strazzulla, Giovanni; Starukhina, Larissa; Dotto, Elisabetta; Barucci, Maria Antonietta; Arnold, Gabriele; Distefano, Elisa

    2004-07-01

    Most ion irradiation experiments relevant to primitive outer Solar System objects have been performed on ice and silicate targets. Here we present the first ion irradiation experiments performed on natural complex hydrocarbons (asphaltite and kerite). These materials are very dark in the visible and have red-sloped spectra in the visible and near-infrared. They may be comparable in composition and structure to refractory organic solids on the surfaces of primitive outer Solar System objects. We irradiated the samples with 15-400 keV H +, N +, Ar ++, and He + ions and measured their reflectance spectra in the range of 0.3-2.5 μm before ion implantation and after each irradiation step. The results show that irradiation-induced carbonization gradually neutralizes the spectral slopes of these red organic solids. This implies a similar space weathering trend for the surfaces of airless bodies optically dominated by spectrally red organic components. The reduction of spectral slope was observed in all experiments. Irradiation with 30 keV protons, which transfers energy to the target mostly via electronic (inelastic) collisions, showed lower efficiency than the heavier ions. We found that spectral alteration in our experiments increased with increasing contribution of nuclear versus electronic energy loss. This implies that nuclear (elastic) energy deposition plays an important role in changing the optical properties of irradiated refractory complex hydrocarbon materials. Finally, our results indicated that temperature variations from 40 K to room temperature did not influence the spectral properties of these complex hydrocarbon solids.

  6. Ionizing irradiation-induced radical stress stalls live meiotic chromosome movements by altering the actin cytoskeleton

    PubMed Central

    Illner, Doris; Scherthan, Harry

    2013-01-01

    Meiosis generates haploid cells or spores for sexual reproduction. As a prelude to haploidization, homologous chromosomes pair and recombine to undergo segregation during the first meiotic division. During the entire meiotic prophase of the yeast Saccharomyces cerevisiae, chromosomes perform rapid movements that are suspected to contribute to the regulation of recombination. Here, we investigated the impact of ionizing radiation (IR) on movements of GFP–tagged bivalents in live pachytene cells. We find that exposure of sporulating cultures with >40 Gy (4-krad) X-rays stalls pachytene chromosome movements. This identifies a previously undescribed acute radiation response in yeast meiosis, which contrasts with its reported radioresistance of up to 1,000 Gy in survival assays. A modified 3′-end labeling assay disclosed IR-induced dsDNA breaks (DSBs) in pachytene cells at a linear dose relationship of one IR-induced DSB per cell per 5 Gy. Dihydroethidium staining revealed formation of reactive oxygen species (ROS) in irradiated cells. Immobility of fuzzy-appearing irradiated bivalents was rescued by addition of radical scavengers. Hydrogen peroxide-induced ROS did reduce bivalent mobility similar to 40 Gy X IR, while they failed to induce DSBs. IR- and H2O2-induced ROS were found to decompose actin cables that are driving meiotic chromosome mobility, an effect that could be rescued by antioxidant treatment. Hence, it appears that the meiotic actin cytoskeleton is a radical-sensitive system that inhibits bivalent movements in response to IR- and oxidant-induced ROS. This may be important to prevent motility-driven unfavorable chromosome interactions when meiotic recombination has to proceed in genotoxic environments. PMID:24046368

  7. Posttreatment with sodium arsenite alters the mutational spectrum induced by ultraviolet light irradiation in Chinese hamster ovary cells

    SciTech Connect

    Yang, Jia-Ling; Chen, Mei-Fang; Wu, Cheng-Wen; Lee, Te-Chang )

    1992-01-01

    Arsenic, a potent carcinogen, fails to induce gene mutations in mammalian cells. However, posttreatment of ultraviolet light (UV)-irradiated cells with sodium arsenite synergstically enhances the mutation frequency on the hypoxanthine (Guanine) phosphoribosyltransferase locus. To investigate the molecular mechanism of the comutagenic effects of sodium arsenite, the authors characterized the alternations of nucleotide sequences in 30 UV-induced and 39 sodium arsenite enhanced hprt mutants from CHinese hamster ovary K1 cells by direct sequencing of mRNA-PCR amplified cDNA. The majority of sequence alterations derived from UV irradiation (80%) and from sodium arsenite posttreatment (70%) were single base substitutions. UV irradiation induced all types of base substitutions. Among them, 57% were transversions. The frequency of transversion increased to 70% in sodium arsenite enhanced mutants. While base substitutions observed in UV-induced mutants were evenly distributed along with the whole coding region, exons 3 and 8 were most frequently mutated in sodium arsenite enhanced mutants. Sodium arsenite posttreatment did not alter the strand bias for mutation induction, i.e., 73% and 78%, of the mutations were located on the non-transcribed strand in UV-induced and sodium arsenite enhanced mutants, respectively. In contrast to UV-induced mutations, bases at the 5' position of TT and the 3' position of CT sequences were the most frequent mutation sites observed in sodium arsenite enhanced mutants. The authors hypothesize that sodium arsenite may interfere with the process of mutation fixation of TT and CT dimers during DNA replication. 50 refs., 2 figs., 6 tabs.

  8. Early and late radiation-induced skin alterations. Part II: Nursing care of irradiated skin.

    PubMed

    Sitton, E

    1992-07-01

    Teaching patients how to care for irradiated skin during and after a course of radiation therapy is a major concern of oncology nurses. Part I of this two-part article (ONF 19(5):801-807) focused on the mechanisms of skin injury. Many topical preparations are available for skin care. When these substances are applied, both the active ingredient and the vehicle must be appropriate for the condition being treated. Preparations may be applied to the skin as liquids (e.g., lotions, solutions, tinctures used in wet dressings, soaks, baths) or solids (e.g., powders, creams, ointments). As skin reaction progresses during a course of radiation therapy, recommendations for skin care will change. Healing of injury occurs in three stages: inflammation, proliferation, and maturation. Wound healing proceeds more rapidly in a moist environment, and a variety of occlusive dressings can be used with moist desquamation.

  9. Assessment of alterations in X-ray irradiation-induced DNA damage of glioma cells by using proton nuclear magnetic resonance spectroscopy.

    PubMed

    Li, Hongxia; Xu, Yanjie; Shi, Wenqi; Li, Fuyan; Zeng, Qingshi; Yi, Cui

    2017-03-01

    Glioma is one of the most common types of brain tumors. DNA damage is closely associated with glioma cell apoptosis induced by X-ray irradiation. Alterations of metabolites in glioma can be detected noninvasively by proton nuclear magnetic resonance (1H NMR) spectroscopy. To noninvasively explore the micro mechanism in X-ray irradiation-induced apoptosis, the relationship between metabolites and DNA damage in glioma cells was investigated. Three glioma cell lines (C6, U87 and U251) were randomly designated as control (0Gy) and treatment groups (1, 5, 10, 15Gy). After X-ray exposure, each group was separated into four parts: (i) to detect metabolites by 1H NMR spectroscopy; (ii) to make cell colonies; (iii) to detect cell cycle distribution and apoptosis rate by flow cytometry; and (iv) to measure DNA damage by comet assay. The metabolite ratios of lactate/creatine and succinate/creatine decreased (lactate/creatine: C6, 22.17-66.27%; U87, 15.93-44.56%; U251, 26.27-74.48%. succinate/creatine: C6, 14.41-48.35%; U87, 22.03-70.62%; U251, 17.33-60.06%) and choline/creatine increased (C6, 52.22-389.68%; U87, 56.15-82.36%; U251, 31.87-278.62%) in the treatment groups compared with the control group (each P<0.05), which linearly depended on DNA damage. An increasing dose of X-ray irradiation increased numbers of apoptotic cells (P<0.01), and the DNA damage parameters were dose-dependent (P<0.05). The colony-forming rate declined (P<0.01) and the percentage of cells at G1 stage increased when exposed to 1Gy X-ray (three cell lines, P<0.05). Metabolite alterations detected by 1H NMR spectroscopy can be used to determine DNA damage induced by X-ray irradiation. 1H NMR spectroscopy is a noninvasive method to predict DNA damage of glioma cell at the micro level.

  10. [Functional alterations in the retina following a 10 Gy gamma irradiation localized in the eye].

    PubMed

    Bagot, J D; Courant, D; Court, L

    1980-11-17

    A single-eye irradiation of 10 Gy (0.8 Gy. min-1) induces impairments of the electrical responses of the rabbit retina in dark adaptation. These are associated with reversible alteration of the photoreceptors and the preganglionic neurons and a disturbance of all the mechanisms of adaptation. Possible relationships between these functional alterations and the effects of irradiation are discussed.

  11. Purple grape juice as a protector against acute x-irradiation induced alterations on mobility, anxiety, and feeding behaviour in mice.

    PubMed

    Soares, Félix A A; Dalla Corte, Cristiane L; Andrade, Edson R; Marina, Raquel; González, Paquita; Barrio, Juan P

    2014-04-01

    The aim of this work was to test the hypothesis that a moderate intake of organic purple grape juice shows a positive radiomodifier effect over early behavioural damage following acute X-irradiation in mice. Anxiety-, locomotion-, and feeding-related responses to 6 Gy total body X-irradiation (TBI) were studied via open field, Rotarod, and feeding/drinking recording. Thirty-two male mice weighing 25-30 g were grouped according grape juice (J) or water (W) ad libitum drinking and either non-irradiated (N) or irradiated (R). 24 h post-TBI the access frequency to the center and corners of the open field was decreased, and the total stay in the corners increased, in RW vs. NW mice. Anxiety-related parameters decreased in RJ vs. RW mice. Rotarod latency times increased 72 h post-TBI in RJ vs RW mice. No overall changes in food and drink intake were observed along the experimental period. On the irradiation day, bout number was increased and bout duration was decreased in RW mice. The changes were reversed by purple grape juice intake. Grape juice intake before and after TBI can overcome several radiation-induced changes in behaviour within 24-72 hours after sub-lethal X-irradiation. This beneficial effect on short-term anxiety and mobilityrelated activities could probably be included in the list of flavonoid bio-effects. The present findings could be relevant in designing preventive interventions aimed to enhance body defense mechanisms against short-term irradiation damage.

  12. Alterations in rat cardiac myosin isozymes induced by whole-body irradiation are prevented by 3,5,3'-L-triiodothyronine

    SciTech Connect

    Litten, R.Z.; Fein, H.G.; Gainey, G.T.; Walden, T.L.; Smallridge, R.C. )

    1990-01-01

    Changes in cardiac myosin isozymes and serum thyroid hormone levels were investigated in rats following 10 Gy whole-body gamma irradiation. The percent beta-myosin heavy chain increased from 21.3 {plus minus} 1.8 to 28.1 {plus minus} 6.8 (NS) at 3-day postirradiation, 37.7 {plus minus} 1.9 (P less than .001) at 6-day postirradiation, and 43.8 {plus minus} 3.3 (P less than .001) at 9-day postirradiation. Along with the change in myosin isozymes was a significant 53% decrease (P less than .001) in the serum thyroxine (T4) level by day 3 postirradiation, remaining depressed through day 9 postirradiation. The serum 3,5,3'-triiodothyronine (T3) level, however, was normal until day 9, when significant depression was also observed. In contrast, the thyroid-stimulating hormone (TSH) level was significantly increased by fourfold at day 3, returning to near normal values by day 9 postirradiation. Daily injections of physiological doses of T3 (0.3 microgram/100 g body weight) prevented the change in the myosin isozymes following whole-body irradiation. Daily pharmacological injections of T3 (3.0 micrograms/100 g body weight) to the irradiated rats produced a further decrease in the percent beta-myosin heavy chain (below control values) indicating tissue hyperthyroidism. Thus, this study suggests that the change in myosin isozymes following whole-body irradiation is caused by an alteration in thyroid hormone activity.

  13. Effect of low dose electron beam irradiation on the alteration layer formed during nuclear glass leaching

    NASA Astrophysics Data System (ADS)

    Mougnaud, S.; Tribet, M.; Renault, J.-P.; Jollivet, P.; Panczer, G.; Charpentier, T.; Jégou, C.

    2016-12-01

    This investigation concerns borosilicate glass leaching mechanisms and the evolution of alteration layer under electron beam irradiation. A simple glass doped with rare earth elements was selected in order to access mechanistic and structural information and better evaluate the effects of irradiation. It was fully leached in initially pure water at 90 °C and at high glass surface area to solution volume ratio (S/V = 20 000 m-1) in static conditions. Under these conditions, the system quickly reaches the residual alteration rate regime. A small particle size fraction (2-5 μm) was sampled in order to obtain a fairly homogeneous altered material enabling the use of bulk characterization methods. External irradiations with 10 MeV electrons up to a dose of 10 MGy were performed either before or after leaching, to investigate respectively the effect of initial glass irradiation on its alteration behavior and the irradiation stability of the alteration layer. Glass dissolution rate was analyzed by regular leachate samplings and the alteration layer structure was characterized by Raman, luminescence (continuous or time-resolved), and 29Si MAS NMR and EPR spectroscopy. It was shown that the small initial glass evolutions under irradiation did not induce any modification of the leaching kinetic nor of the structure of the alteration layer. The alteration process seemed to "smooth over" the created defects. Otherwise, the alteration layer and initial glass appeared to have different behaviors under irradiation. No Eu3+ reduction was detected in the alteration layer after irradiation and the defect creation efficiency was much lower than for initial glass. This can possibly be explained by the protective role of pore water contained in the altered material (∼20%). Moreover, a slight depolymerization of the silicon network of the altered glass under irradiation with electrons was evidenced, whereas in the initial glass it typically repolymerizes.

  14. High salt stress induces swollen prothylakoids in dark-grown wheat and alters both prolamellar body transformation and reformation after irradiation.

    PubMed

    Abdelkader, Amal F; Aronsson, Henrik; Solymosi, Katalin; Böddi, Bela; Sundqvist, Christer

    2007-01-01

    High salinity causes ion imbalance and osmotic stress in plants. Leaf sections from 8-d-old dark-grown wheat (Triticum aestivum cv. Giza 168) were exposed to high salt stress (600 mM) and the native arrangements of plastid pigments together with the ultrastructure of the plastids were studied using low-temperature fluorescence spectroscopy and transmission electron microscopy. Although plastids from salt-treated leaves had highly swollen prothylakoids (PTs) the prolamellar bodies (PLBs) were regular. Accordingly, a slight intensity decrease of the short-wavelength protochlorophyllide (Pchlide) form was observed, but no change was found in the long-wavelength Pchlide form emitting at 656 nm. After irradiation, newly formed swollen thylakoids showed traversing stromal strands. The PLB dispersal was partly inhibited and remnants of the PLBs formed an electron-dense structure, which remained after prolonged (8 h) irradiation. The difference in fluorescence emission maximum of the main chlorophyll form in salt-stressed leaves (681 nm) and in control leaves (683 nm) indicated a restrained formation of the photosynthetic apparatus. Overall chlorophyll accumulation during prolonged irradiation was inhibited. Salt-stressed leaves returned to darkness after 3 h of irradiation had, compared with the control, a reduced amount of Pchlide and reduced re-formation of regular net-like PLBs. Instead, the size of the electron-dense structures increased. This study reports, for the first time, the salt-induced swelling of PTs and reveals traversing stromal strands in newly formed thylakoids. Although the PLBs were intact and the Pchlide fluorescence emission spectra appeared normal after salt stress in darkness, plastid development to chloroplasts was highly restricted during irradiation.

  15. Thalidomide combined with irradiation alters the activity of two proteases.

    PubMed

    Şimşek, Ece; Aydemir, Esra; Korcum, Aylin Fidan; Fişkın, Kayahan

    2015-02-01

    The aim of the present study was to investigate the effects of thalidomide, a drug known for its anti‑angiogenic and antitumor properties, at its cytotoxic dose previously determined as 40 µg/ml (according to four cytotoxic test results). The effect of the drug alone and in combination with radiotherapy using Cobalt 60 (60Co) at 45 Gy on the enzymatic activity of substance‑P degrading A disintegrin and metalloproteinase (ADAM)10 and neprilysin (NEP) was investigated in the mouse breast cancer cell lines 4T1 and 4T1 heart metastases post‑capsaicin (4THMpc). Thalidomide (40 µg/ml) exerted differing effects on the activities of ADAM10 and NEP enzymes. In 4T1 cells, 40 µg/ml thalidomide alone did not alter ADAM10 enzyme activity. 60Co irradiation at 45 Gy alone caused a 42% inhibition in ADAM10 activity, however, the inhibition increased to 89% when combined therapy was used. By contrast, in the 4THMpc cell line, 40 µg/ml thalidomide alone induced a 66.6% increase in ADAM10 enzyme activity. Radiotherapy alone and thalidomide with 60Co combined therapy caused a 33.3 and 40% inhibition of ADAM10 activity, respectively. In 4T1 cells, thalidomide alone caused a 40.9% increase in NEP activity. Radiation therapy alone or in combination with the drug caused a 40.7% increase in NEP activity. In more aggressive 4THMpc cells, thalidomide alone caused a 26.6% increase in NEP activity. Radiotherapy alone and combined therapy caused a 33.3 and 37% increase in enzyme activity, respectively. To the best of our knowledge, the present study is the first to demonstrate that thalidomide alone or in combination with radiotherapy exhibits significant cytotoxic effects on 4T1 and 4THMpc mouse breast cancer cell lines indicating that this drug affects the enzymatic activity of ADAM10 and NEP in vitro.

  16. Prenatal exposure to gamma/neutron irradiation: Sensorimotor alterations and paradoxical effects on learning

    SciTech Connect

    Di Cicco, D.; Antal, S.; Ammassari-Teule, M. )

    1991-01-01

    The effects of prenatal exposure on gamma/neutron radiations (0.5 Gy at about the 18th day of fetal life) were studied in a hybrid strain of mice (DBA/Cne males x C57BL/Cne females). During ontogeny, measurements of sensorimotor reflexes revealed in prenatally irradiated mice (1) a delay in sensorial development, (2) deficits in tests involving body motor control, and (3) a reduction of both motility and locomotor activity scores. In adulthood, the behaviour of prenatally irradiated and control mice was examined in the open field test and in reactivity to novelty. Moreover, their learning performance was compared in several situations. The results show that, in the open field test, only rearings were more frequent in irradiated mice. In the presence of a novel object, significant sex x treatment interactions were observed since ambulation and leaning against the novel object increased in irradiated females but decreased in irradiated males. Finally, when submitted to different learning tasks, irradiated mice were impaired in the radial maze, but paradoxically exhibited higher avoidance scores than control mice, possibly because of their low pain thresholds. Taken together, these observations indicate that late prenatal gamma/neutron irradiation induces long lasting alterations at the sensorimotor level which, in turn, can influence learning abilities of adult mice.

  17. Polymer Morphological Change Induced by Terahertz Irradiation.

    PubMed

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-07

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced "softly," without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10-20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm(2), which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  18. Ionising irradiation alters the dynamics of human long interspersed nuclear elements 1 (LINE1) retrotransposon.

    PubMed

    Tanaka, Atsushi; Nakatani, Youko; Hamada, Nobuyuki; Jinno-Oue, Atsushi; Shimizu, Nobuaki; Wada, Seiichi; Funayama, Tomoo; Mori, Takahisa; Islam, Salequl; Hoque, Sheikh Ariful; Shinagawa, Masahiko; Ohtsuki, Takahiro; Kobayashi, Yasuhiko; Hoshino, Hiroo

    2012-09-01

    It is important to identify the mechanism by which ionising irradiation induces various genomic alterations in the progeny of surviving cells. Ionising irradiation activates mobile elements like retrotransposons, although the mechanism of its phenomena consisting of transcriptions and insertions of the products into new sites of the genome remains unclear. In this study, we analysed the effects of sparsely ionising X-rays and densely ionising carbon-ion beams on the activities of a family of active retrotransposons, long interspersed nuclear elements 1 (L1). We used the L1/reporter knock-in human glioma cell line, NP-2/L1RP-enhanced GFP (EGFP), that harbours full-length L1 tagged with EGFP retrotransposition detection cassette (L1RP-EGFP) in the chromosomal DNA. X-rays and carbon-ion beams similarly increased frequencies the transcription from L1RP-EGFP and its retrotransposition. Short-sized de novo L1RP-EGFP insertions with 5'-truncation were induced by X-rays, while full-length or long-sized insertions (>5 kb, containing ORF1 and ORF2) were found only in cell clones irradiated by the carbon-ion beams. These data suggest that X-rays and carbon-ion beams induce different length of de novo L1 insertions, respectively. Our findings thus highlight the necessity to investigate the mechanisms of mutations caused by transposable elements by ionising irradiation.

  19. Dose-Dependent Metabolic Alterations in Human Cells Exposed to Gamma Irradiation

    PubMed Central

    Kwon, Yong-Kook; Ha, In Jin; Bae, Hyun-Whee; Jang, Won Gyo; Yun, Hyun Jin; Kim, So Ra; Lee, Eun Kyeong; Kang, Chang-Mo; Hwang, Geum-Sook

    2014-01-01

    Radiation exposure is a threat to public health because it causes many diseases, such as cancers and birth defects, due to genetic modification of cells. Compared with the past, a greater number of people are more frequently exposed to higher levels of radioactivity today, not least due to the increased use of diagnostic and therapeutic radiation-emitting devices. In this study, ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS)-based metabolic profiling was used to investigate radiation- induced metabolic changes in human fibroblasts. After exposure to 1 and 5 Gy of γ-radiation, the irradiated fibroblasts were harvested at 24, 48, and 72 h and subjected to global metabolite profiling analysis. Mass spectral peaks of cell extracts were analyzed by pattern recognition using principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The results showed that the cells irradiated with 1 Gy returned to control levels at 72 h post radiation, whereas cells irradiated with 5 Gy were quite unlike the controls; therefore, cells irradiated with 1 Gy had recovered, whereas those irradiated with 5 Gy had not. Lipid and amino acid levels increased after the higher-level radiation, indicating degradation of membranes and proteins. These results suggest that MS-based metabolite profiling of γ-radiation-exposed human cells provides insight into the global metabolic alterations in these cells. PMID:25419661

  20. Anti-inflammatory effect of selenium nanoparticles on the inflammation induced in irradiated rats.

    PubMed

    El-Ghazaly, M A; Fadel, N; Rashed, E; El-Batal, A; Kenawy, S A

    2017-02-01

    Selenium (Se) has been reported to possess anti-inflammatory properties, but its bioavailability and toxicity are considerable limiting factors. The present study aimed to investigate the possible anti-inflammatory and analgesic effects of selenium nanoparticles (Nano-Se) on inflammation induced in irradiated rats. Paw volume and nociceptive threshold were measured in carrageenan-induced paw edema and hyperalgesia model. Leukocytic count, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), thiobarbituric acid reactive substances (TBAR), and total nitrate/nitrite (NOx) were estimated in the exudate collected from 6 day old air pouch model. Irradiated rats were exposed to 6 Gy gamma (γ)-irradiation. Nano-Se were administered orally in a dose of 2.55 mg/kg once before carrageenan injection in the first model and twice in the second model. The paw volume but not the nociceptive response produced by carrageenan in irradiated rats was higher than that induced in non-irradiated rats. Nano-Se were effective in reducing the paw volume in non-irradiated and irradiated rats but it did not alter the nociceptive threshold. The inflammation induced in irradiated rats increased all the estimated parameters in the exudate whereas; Nano-Se decreased their elevation in non-irradiated and irradiated rats. Nano-Se possess a potential anti-inflammatory activity on inflammation induced in irradiated rats.

  1. RESTORATION INDUCED BY CATALASE IN IRRADIATED MICROORGANISMS

    PubMed Central

    Latarjet, Raymond; Caldas, Luis Renato

    1952-01-01

    1. E. coli, strain K-12, and B. megatherium 899, irradiated in strict but still undefined physiological conditions with certain heavy doses of ultraviolet light, are efficiently restored by catalase, which acts on or fixes itself upon the bacteria in a few minutes. This restoration (C. R.), different from photorestoration, is aided by a little visible light. 2. At 37° the restorability lasts for about 2 hours after UV irradiation; the restored cells begin to divide at the same time as the normal survivors. 3. C. R. is not produced after x-irradiation. 4. B. megatherium Mox and E. coli, strain B/r show little C. R.; E. coli strain B shows none. None of these three strains is lysogenic, whereas the two preceding catalase-restorable strains are. 5. Phage production in the system "K-12 infected with T2 phage" is restored by catalase after UV irradiation, whereas phage production in the system "infected B" is not. 6. With K-12, catalase does not prevent the growth of phage and the lysis induced by UV irradiation (Lwoff's phenomenon). 7. Hypotheses are discussed concerning: (a) the chemical nature of this action of catalase; (b) a possible relation between C. R. and lysogenicity of the sensitive bacteria; (c) the consequences of such chemical restorations on the general problem of cell radiosensitivity. PMID:14898028

  2. Polymer Morphological Change Induced by Terahertz Irradiation

    PubMed Central

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-01-01

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10−20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules. PMID:27272984

  3. Polymer Morphological Change Induced by Terahertz Irradiation

    NASA Astrophysics Data System (ADS)

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-01

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced “softly,” without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10‑20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm2, which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  4. Antitumor Immunity Induced after α Irradiation123

    PubMed Central

    Gorin, Jean-Baptiste; Ménager, Jérémie; Gouard, Sébastien; Maurel, Catherine; Guilloux, Yannick; Faivre-Chauvet, Alain; Morgenstern, Alfred; Bruchertseifer, Frank; Chérel, Michel; Davodeau, François; Gaschet, Joëlle

    2014-01-01

    Radioimmunotherapy (RIT) is a therapeutic modality that allows delivering of ionizing radiation directly to targeted cancer cells. Conventional RIT uses β-emitting radioisotopes, but recently, a growing interest has emerged for the clinical development of α particles. α emitters are ideal for killing isolated or small clusters of tumor cells, thanks to their specific characteristics (high linear energy transfer and short path in the tissue), and their effect is less dependent on dose rate, tissue oxygenation, or cell cycle status than γ and X rays. Several studies have been performed to describe α emitter radiobiology and cell death mechanisms induced after α irradiation. But so far, no investigation has been undertaken to analyze the impact of α particles on the immune system, when several studies have shown that external irradiation, using γ and X rays, can foster an antitumor immune response. Therefore, we decided to evaluate the immunogenicity of murine adenocarcinoma MC-38 after bismuth-213 (213Bi) irradiation using a vaccination approach. In vivo studies performed in immunocompetent C57Bl/6 mice induced a protective antitumor response that is mediated by tumor-specific T cells. The molecular mechanisms potentially involved in the activation of adaptative immunity were also investigated by in vitro studies. We observed that 213Bi-treated MC-38 cells release “danger signals” and activate dendritic cells. Our results demonstrate that α irradiation can stimulate adaptive immunity, elicits an efficient antitumor protection, and therefore is an immunogenic cell death inducer, which provides an attractive complement to its direct cytolytic effect on tumor cells. PMID:24862758

  5. Cadmium Nanowire Formation Induced by Ion Irradiation

    SciTech Connect

    Jiang, Weilin; Weber, William J.; Wang, Chong M.; Young, James S.; Boatner, Lynn A.; Lian, Jie; Wang, Lumin; Ewing, Rodney C.

    2005-07-04

    One-dimensional nanostructures, such as nanowires, of semiconductors and metals are of great technological interest due to their potential for many advanced technology applications. Utilization of these materials versus their bulk counterparts will not only allow for device miniaturisation, but also may improve device performance or create new functions. Here we report a novel method for the synthesis of crystalline Cd-nanowires without involving either templates or a “seeded” structure. Ion irradiation at low temperatures (≤ 295 K) has been used to induce material decomposition and phase segregation in a cadmium niobate pyrochlore (Cd2Nb2O7) wafer. During the formation and rupture of the gas-filled blisters in the material, soft metallic Cd is extruded/extracted as nanowires through pores in the exfoliated layer. The entire process may be readily controlled by changing the ion irradiation conditions (e.g., ion species, dose and energy) with minimal thermal constraints.

  6. Alterations in immune responses in prenatally irradiated dogs

    SciTech Connect

    Nold, J.B.; Benjamin, S.A.; Miller, G.K.

    1988-09-01

    Immunologic responses were studied in beagle dogs following prenatal (35 days gestation) irradiation to evaluate the effects of ionizing radiation on the developing immune system. Each dog received 1.5 Gy /sup 60/Co gamma irradiation or sham irradiation. Prenatally irradiated dogs exhibited a significant reduction in primary humoral antibody responses to inoculated sheep red blood cells, a T-dependent antigen, and a concurrent decrease in T-helper lymphocyte subpopulations in the peripheral blood at 3 to 4 months of age. Similarly, irradiated fetuses have been shown to have defects in epitheliostromal development of the thymus. It is suggested that the postnatal immunologic deficits may relate to the prenatal thymic injury.

  7. Life span alteration after irradiation in Drosophila melanogaster strains with mutations of Hsf and Hsps.

    PubMed

    Moskalev, A; Shaposhnikov, M; Turysheva, E

    2009-02-01

    The life span alteration after gamma-irradiation and/or paraquat treatment in Drosophila in wild type strain Canton-S and strains with mutations of heat shock factor (1-4 alleles) and heat shock proteins (Hsp70Ba ( 304 ), Hsp83 ( e6A ), Hsp22 ( EY09909 ), Hsp67Bb ( EY099099 )) was investigated. Chronic low-dose rate gamma-irradiation (0.017 and 0.17 cGy/h) on pre-imago stages was used as a priming dose (absorbed doses were 4 and 40 cGy). Paraquat, a free radical inducing agent, was a challenging factor (20 mM for 1 day). It was shown that chronic irradiation led to adaptive response in both sexes except homozygous males and females with mutations of Hsf ( 4 ) and Hsp70Ba ( 304 ). The gender-specific differences in stress response were discovered in wild type strain Canton-S, Hsp22 ( EY09909 ) Hsp67Bb ( EY09909 ) homozygotes and Hsp83 ( e6A ) heterozygotes: the adaptive response persisted in males, but not in females. Thus, Drosophila Hsp and Hsf mutation homozygotes did not demonstrate the adaptive response in the majority of cases, implying an important role of those genes in radiation hormesis and adaptation to stresses.

  8. Local brain heavy ion irradiation induced Immunosuppression

    NASA Astrophysics Data System (ADS)

    Lei, Runhong; Deng, Yulin; Huiyang Zhu, Bitlife.; Zhao, Tuo; Wang, Hailong; Yu, Yingqi; Ma, Hong; Wang, Xiao; Zhuang, Fengyuan; Qing, Hong

    Purpose: To investigate the long term effect of acute local brain heavy ion irradiation on the peripheral immune system in rat model. Methodology: Only the brain of adult male Wistar rats were radiated by heavy ions at the dose of 15 Gy. One, two and three months after irradiation, thymus and spleen were analyzed by four ways. Tunel assay was performed to evaluate the percentage of apoptotic cells in thymus and spleen, level of Inflammatory cytokines (IL-2, IL-6, SSAO, and TNF-α) was detected by ELISA assay, the differentiation of thymus T lymphocyte subsets were measured by flow cytometry and the relative expression levels of genes related to thymus immune cell development were measured by using quantitative real-time PCR. Results: Thymus and spleen showed significant atrophy from one month to three months after irradiation. A high level of apoptosis in thymus and spleen were obtained and the latter was more vulnerable, also, high level of inflammatory cytokines were found. Genes (c-kit, Rag1, Rag2 and Sca1) related to thymus lymphocytes’ development were down-regulated. Conclusion: Local area radiation in the rat brain would cause the immunosuppression, especially, the losing of cell-mediated immune functions. In this model, radiation caused inflammation and then induced apoptosis of cells in the immune organs, which contributed to immunosuppression.

  9. Altered motility causes the early gastrointestinal toxicity of irradiation

    SciTech Connect

    Erickson, B.A.; Moulder, J.E.; Otterson, M.F.; Sarna, S.K. )

    1994-03-01

    This article reviews studies of large and small intestinal contractile activity following radiation exposure. Studies of motility utilize strain gauge transducers surgically implanted on the seromuscular layer of the small intestine. All studies were performed in mixed breed dogs to record the occurrence of normal contractions, giant migrating contractions (GMCs) and retrograde giant contractions (RGCs) before, during and after irradiation (22.5 Gy in 9 fractions at 3 fractions/week). Giant migrating contractions and retrograde giant contractions are infrequent in the healthy state. However, in diseased states, GMCs are associated with abdominal cramps and diarrhea, and RGCs precede vomiting. In fasted animals, fractionated abdominal irradiation dramatically increased the frequency of GMCs, with the incidence peaking after the second dose. The increased frequency of GMCS occurred as early as a few hours after the first radiation fraction, and returned to normal within days of cessation of radiation. RGCs were also significantly increased after abdominal irradiation. The frequency of RGCs was greatest on the first and sixth dose of radiation. Clinically, the dogs developed nausea, vomiting and diarrhea as early as the first day of irradiation. In dogs studied in the fed state, decreased amplitude, duration, and frequency of postprandial contractions occurred. These changes may slow intestinal transit during irradiation. Radiation also produced a striking increase in the frequency of colonic GMCs; these changes in colonic motor activity were associated with diarrhea as early as the second irradiation. Changes in GI motility during fractionated irradiation precede the appearance of histopathological lesions in the GI tract. Thus, the symptoms of nausea, vomiting, and diarrhea experienced during radiotherapy (particularly those within the first week) are directly related to changes in bowel motility. 41 refs., 7 figs., 1 tab.

  10. Chromosomal instability induced by heavy ion irradiation

    NASA Technical Reports Server (NTRS)

    Limoli, C. L.; Ponnaiya, B.; Corcoran, J. J.; Giedzinski, E.; Morgan, W. F.

    2000-01-01

    PURPOSE: To establish the dose-response relationship for the induction of chromosomal instability in GM10115 cells exposed to high-energy iron ions (1 GeV/nucleon, mean LET 146 keV/microm) and gold ions (11 GeV/nucleon, mean LET 1450 keV/microm). Past work has established that sparsely ionizing X-rays can induce a long-lived destabilization of chromosomes in a dose-dependent manner at an incidence of approximately 3% per gray. The present investigation assesses the capacity of High-Z and High-energy (HZE) particles to elicit this same endpoint. MATERIALS AND METHODS: Clonal populations derived from single progenitor cells surviving heavy-ion irradiation were analyzed cytogenetically to identify those clones showing a persistent destablization of chromosomes. RESULTS: Dose-response data, with a particular emphasis at low dose (< 1.0 Gy), indicate a frequency of approximately 4% per gray for the induction of chromosomal instability in clones derived from single progenitor cells surviving exposure to iron ions. The induction of chromosomal instability by gold ions was, however, less responsive to applied dose, as the observed incidence of this phenotype varied from 0 to 10% over 1-8 Gy. Both iron and gold ions gave dose-dependent increases in the yield of chromosomal aberrations (both chromosome- and chromatid-type) measured at the first mitosis following irradiation, as well as shoulderless survival curves having D0=0.87 and 1.1 Gy respectively. CONCLUSIONS: Based on the present dose-response data, the relative biological effectiveness of iron ions is 1.3 for the induction of chromosomal instability, and this indicates that heavy ions are only slightly more efficient than X-rays at eliciting this delayed phenotype.

  11. Hypergravity-induced altered behavior in Drosophila

    NASA Astrophysics Data System (ADS)

    Hosamani, Ravikumar; Wan, Judy; Marcu, Oana; Bhattacharya, Sharmila

    2012-07-01

    Microgravity and mechanical stress are important factors of the spaceflight environment, and affect astronaut health and behavior. Structural, functional, and behavioral mechanisms of all cells and organisms are adapted to Earth's gravitational force, 1G, while altered gravity can pose challenges to their adaptability to this new environment. On ground, hypergravity paradigms have been used to predict and complement studies on microgravity. Even small changes that take place at a molecular and genetic level during altered gravity may result in changes in phenotypic behavior. Drosophila provides a robust and simple, yet very reliable model system to understand the complexity of hypergravity-induced altered behavior, due to availability of a plethora of genetic tools. Locomotor behavior is a sensitive parameter that reflects the array of molecular adaptive mechanisms recruited during exposure to altered gravity. Thus, understanding the genetic basis of this behavior in a hypergravity environment could potentially extend our understanding of mechanisms of adaptation in microgravity. In our laboratory we are trying to dissect out the cellular and molecular mechanisms underlying hypergravity-induced oxidative stress, and its potential consequences on behavioral alterations by using Drosophila as a model system. In the present study, we employed pan-neuronal and mushroom body specific knock-down adult flies by using Gal4/UAS system to express inverted repeat transgenes (RNAi) to monitor and quantify the hypergravity-induced behavior in Drosophila. We established that acute hypergravity (3G for 60 min) causes a significant and robust decrease in the locomotor behavior in adult Drosophila, and that this change is dependent on genes related to Parkinson's disease, such as DJ-1α , DJ-1β , and parkin. In addition, we also showed that anatomically the control of this behavior is significantly processed in the mushroom body region of the fly brain. This work links a molecular

  12. Ascorbate, added after irradiation, reduces the mutant yield and alters the spectrum of CD59- mutations in A(L) cells irradiated with high LET carbon ions

    NASA Technical Reports Server (NTRS)

    Ueno, Akiko; Vannais, Diane; Lenarczyk, Marek; Waldren, Charles A.; Chatterjee, A. (Principal Investigator)

    2002-01-01

    It has been reported that X-ray induced HPRT- mutation in cultured human cells is prevented by ascorbate added after irradiation. Mutation extinction is attributed to neutralization by ascorbate, of radiation-induced long-lived radicals (LLR) with half-lives of several hours. We here show that post-irradiation treatment with ascorbate (5 mM added 30 min after radiation) reduces, but does not eliminate, the induction of CD59- mutants in human-hamster hybrid A(L) cells exposed to high-LET carbon ions (LET of 100 KeV/microm). RibCys, [2(R,S)-D-ribo-1',2',3',4'-Tetrahydroxybutyl]-thiazolidene-4(R)-ca riboxylic acid] (4 mM) gave a similar but lesser effect. The lethality of the carbon ions was not altered by these chemicals. Preliminary data are presented that ascorbate also alters the spectrum of CD59- mutations induced by the carbon beam, mainly by reducing the incidence of small mutations and mutants displaying transmissible genomic instability (TGI), while large mutations are unaffected. Our results suggest that LLR are important in initiating TGI.

  13. Genomic Instability Induced by Low Dose Irradiation

    SciTech Connect

    Evans, Helen H. Sedwick, David W. Veigl, Martina L.

    2006-07-15

    The goal of this project was to determine if genomic instability could be initiated by poorly repaired DNA damage induced by low doses of ionizing radiation leading to a mutator phenotype. Human cells were irradiated, then transfected with an unirradiated reporter gene at various times AFTER exposure. The vector carried an inactive GFP gene that fluoresced when the gene was activated by a delayed mutation. Fluorescent cells were measured in the interval of 50 hours to four days after transfection. The results showed that delayed mutations occurred in these cells after exposure to relatively low doses (0.3-1.0 Gy) of low or high ionizing radiation, as well as after treatment with hyrodgen peroxide (30-100 micromolar). The occurrence was both dose and time dependent, often decreasing at higher doses and later times. No marked difference was observed between the response of mis-match repair-proficient and -deficient cell lines. Although the results were quite reproducible within single experiments, difficulties were observed from experiment to experiment. Different reagents and assays were tested, but no improvement resulted. We concluded that this method is not sufficiently robust or consisent to be useful in the assay of the induction of genomic instability by low doses of radiation, at least in these cell lines under our conditions.

  14. Radiation-induced alterations of fracture healing biomechanics

    SciTech Connect

    Pelker, R.R.; Friedlaender, G.E.; Panjabi, M.M.; Kapp, D.; Doganis, A.

    1984-01-01

    The effects of irradiation on the normal temporal progression of the physical properties of healing fractures were studied in a rat model. Fractures were surgically produced in the femur, stabilized with an intramedullary pin, and irradiated. One group of rats was exposed to 2,500 rads in divided doses over 2 weeks, beginning 3 days after fracture, and compared to a control group with fractures which were not irradiated. Animals were sacrificed at periodic intervals and the bones were tested to failure in torsion. The torque, stiffness, and energy increased and the angle decreased for the nonirradiated specimens in the expected fashion. This progression was deleteriously altered in the irradiated femurs.

  15. Hemopathologic consequences of protracted gamma irradiation: alterations in granulocyte reserves and granulocyte mobilization

    SciTech Connect

    Seed, T.M.; Cullen, S.M.; Kaspar, L.V.; Tolle, D.V.; Fritz, T.E.

    1980-07-01

    Aplastic anemia and myelogenous leukemia are prominent pathologic effects in beagles exposed to continuous, daily, low-dose gamma irradiation. In the present work, granulocyte reserves and related mobilization functions have been sequentially assessed by the endotoxin stress assay during the preclinical and clinical phases of these hemopoietic disorders. Characteristic patterns of granulocyte reserve mobilization are described that reflect given stages of pathologic progression. For radiation-induced leukemia, a five-stage pattern has been proposed. In contrast, a simple pattern of progressive, time-dependent contraction of granulocyte reserves and mobilization capacity was noted in the development of terminal aplastic anemia. Early preclinical phases of radiation-induced leukemia appear to involve an extensive depletion of the granulocyte reserves (phase I) during the first approx. 200 days of exposure followed by a partial renewal of the reserves and associated mobilization functions between approx. 200 and 400 days (phase II). Sustained, subnormal granulocyte mobilizations (phase III) following endotoxin stress typify the responses of dogs during the intermediate phase, whereas late preclinical, preleukemic stages (phase IV) are characterized by a further expansion of the reserves and in the mobilization capacities, particularly of the less mature granulocytes. Such late alterations in the pattern of granulocyte mobilization, together with other noted cellular aberrancies in the peripheral blood and marrow, appear to indicate leukemia (phase V) onset.

  16. CCR2 deficiency prevents neuronal dysfunction and cognitive impairments induced by cranial irradiation

    PubMed Central

    Belarbi, Karim; Jopson, Timothy; Arellano, Carla; Fike, John R.; Rosi, Susanna

    2013-01-01

    Cranial irradiation can lead to long-lasting cognitive impairments in patients receiving radiotherapy for the treatment of malignant brain tumors. Recent studies have suggested inflammation as a major contributor to these deficits; we determined if the chemokine receptor 2 (CCR2) was a mediator of cognitive impairments induced by irradiation. Two-month-old male Ccr2 knockout (−/−) and wild-type (WT) mice received 10 Gy cranial irradiation or sham-treatment. One month after irradiation, bromodeoxyuridine was injected intraperitoneally for seven consecutive days to label newly generated cells. At two months post-irradiation, cognitive function was assessed by novel object recognition and Morris water maze. Our results demonstrate that CCR2 deficiency prevented hippocampus-dependent spatial learning and memory impairments induced by cranial irradiation. Hippocampal gene expression analysis showed that irradiation induced CCR2 ligands such as CCL8, and CCR2 deficiency reduced this induction. Irradiation reduced the number of adult-born neurons in both WT and Ccr2−/− mice, but the distribution pattern of the adult-born neurons through the granule cell layer was only altered in WT mice. Importantly, CCR2 deficiency normalized the fraction of pyramidal neurons expressing the plasticity-related immediate early gene Arc. These data offer new insight into the mechanism(s) of radiation-injury and suggest that CCR2 is a critical mediator hippocampal neuronal dysfunction and hippocampal cognitive impairments after irradiation. Targeting CCR2 signaling could conceivably provide an effective approach to reduce or prevent the incidence and severity of this serious side effect of ionizing irradiation. PMID:23243025

  17. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    SciTech Connect

    Lee, Won Hee; Warrington, Junie P.; Sonntag, William E.; Lee, Yong Woo

    2012-04-01

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy {gamma}-rays or a fractionated dose of 40 Gy {gamma}-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  18. CCR2 deficiency prevents neuronal dysfunction and cognitive impairments induced by cranial irradiation.

    PubMed

    Belarbi, Karim; Jopson, Timothy; Arellano, Carla; Fike, John R; Rosi, Susanna

    2013-02-01

    Cranial irradiation can lead to long-lasting cognitive impairments in patients receiving radiotherapy for the treatment of malignant brain tumors. Recent studies have suggested inflammation as a major contributor to these deficits; we determined if the chemokine (C-C motif) receptor 2 (CCR2) was a mediator of cognitive impairments induced by irradiation. Two-month-old male Ccr2 knockout (-/-) and wild-type mice received 10 Gy cranial irradiation or sham-treatment. One month after irradiation, bromodeoxyuridine was injected intraperitoneally for seven consecutive days to label newly generated cells. At two months postirradiation, cognitive function was assessed by novel object recognition and Morris water maze. Our results show that CCR2 deficiency prevented hippocampus-dependent spatial learning and memory impairments induced by cranial irradiation. Hippocampal gene expression analysis showed that irradiation induced CCR2 ligands such as CCL8 and CCR2 deficiency reduced this induction. Irradiation reduced the number of adult-born neurons in both wild-type and Ccr2(-/-) mice, but the distribution pattern of the adult-born neurons through the granule cell layer was only altered in wild-type mice. Importantly, CCR2 deficiency normalized the fraction of pyramidal neurons expressing the plasticity-related immediate early gene Arc. These data offer new insight into the mechanism(s) of radiation-injury and suggest that CCR2 is a critical mediator of hippocampal neuronal dysfunction and hippocampal cognitive impairments after irradiation. Targeting CCR2 signaling could conceivably provide an effective approach to reduce or prevent the incidence and severity of this serious side effect of ionizing irradiation.

  19. Irradiation strongly reduces tumorigenesis of human induced pluripotent stem cells.

    PubMed

    Inui, Shoki; Minami, Kazumasa; Ito, Emiko; Imaizumi, Hiromasa; Mori, Seiji; Koizumi, Masahiko; Fukushima, Satsuki; Miyagawa, Shigeru; Sawa, Yoshiki; Matsuura, Nariaki

    2017-03-03

    Induced pluripotent stem (iPS) cells have demonstrated they can undergo self-renewal, attain pluripotency, and differentiate into various types of functional cells. In clinical transplantation of iPS cells, however, a major problem is the prevention of tumorigenesis. We speculated that tumor formation could be inhibited by means of irradiation. Since the main purpose of this study was to explore the prevention of tumor formation in human iPS (hiPS) cells, we tested the effects of irradiation on tumor-associated factors such as radiosensitivity, pluripotency and cell death in hiPS cells. The irradiated hiPS cells showed much higher radiosensitivity, because the survival fraction of hiPS cells irradiated with 2 Gy was < 10%, and there was no change of pluripotency. Irradiation with 2 and 4 Gy caused substantial cell death, which was mostly the result of apoptosis. Irradiation with 2 Gy was detrimental enough to cause loss of proliferation capability and trigger substantial cell death in vitro. The hiPS cells irradiated with 2 Gy were injected into NOG mice (NOD/Shi-scid, IL-2 Rγnull) for the analysis of tumor formation. The group of mice into which hiPS cells irradiated with 2 Gy was transplanted showed significant suppression of tumor formation in comparison with that of the group into which non-irradiated hiPS cells were transplanted. It can be presumed that this diminished rate of tumor formation was due to loss of proliferation and cell death caused by irradiation. Our findings suggest that tumor formation following cell therapy or organ transplantation induced by hiPS cells may be prevented by irradiation.

  20. Ultraviolet irradiation of diacetylenic liposomes as a strategy to improve size stability and to alter protein binding without cytotoxicity enhancement.

    PubMed

    Temprana, C Facundo; Amor, M Silvia; Femia, A Lis; Gasparri, Julieta; Taira, M Cristina; del Valle Alonso, Silvia

    2011-06-01

    Membrane-modification effects, induced by ultraviolet (UV) irradiation in diacetylenic liposomes, were analyzed upon contact with cells, biological membranes, and proteins. Liposomes formulated with mixtures of unsaturated 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine and saturated 1,2-dimyristoyl-sn-glycero-3-phosphocholine, in a 1:1 molar ratio, were compared with those that were UV-irradiated and analyzed in several aspects. Membrane polymerization inherence on size stability was studied as well as its impact on mitochondrial and microsomal membrane peroxidation induction, hemolytic activity, and cell viability. Moreover, in order to gain insight about the possible irradiation effect on interfacial membrane properties, interaction with bovine serum albumin (BSA), lysozyme (Lyso), and apolipoprotein (apoA-I) was studied. Improved size stability was found for polymerized liposomes after a period of 30 days at 4°C. In addition, membrane irradiation had no marked effect on cell viability, hemolysis, or induction of microsomal and mitochondrial membrane peroxidation. Interfacial membrane characteristics were found to be altered after polymerization, since a differential protein binding for polymerized or nonpolymerized membranes was observed for BSA and Lyso, but not for apoA-I. The substantial contribution of this work is the finding that even when maintaining the same lipid composition, changes induced by UV irradiation are sufficient to increase size stability and establish differences in protein binding, in particular, reducing the amount of bound Lyso and BSA, without increasing formulation cytotoxicity. This work aimed at showing that the usage of diacetylenic lipids and UV modification of membrane interfacial properties should be strategies to be taken into consideration when designing new delivery systems.

  1. Postnatal irradiation-induced hippocampal neuropathology, cognitive impairment and aging.

    PubMed

    Tang, Feng Ru; Loke, Weng Keong; Khoo, Boo Cheong

    2017-04-01

    Irradiation of the brain in early human life may set abnormal developmental events into motion that last a lifetime, leading to a poor quality of life for affected individuals. While the effect of irradiation at different early developmental stages on the late human life has not been investigated systematically, animal experimental studies suggest that acute postnatal irradiation with ⩾0.1Gy may significantly reduce neurogenesis in the dentate gyrus and endotheliogenesis in cerebral vessels and induce cognitive impairment and aging. Fractionated irradiation also reduces neurogenesis. Furthermore, irradiation induces hippocampal neuronal loss in CA1 and CA3 areas, neuroinflammation and reduces gliogenesis. The hippocampal neurovascular niche and the total number of microvessels are also changed after radiation exposures. Each or combination of these pathological changes may cause cognitive impairment and aging. Interestingly, acute irradiation of aged brain with a certain amount of radiation has also been reported to induce brain hormesis or neurogenesis. At molecular levels, inflammatory cytokines, chemokines, neural growth factors, neurotransmitters, their receptors and signal transduction systems, reactive oxygen species are involved in radiation-induced adverse effect on brain development and functions. Further study at different omics levels after low dose/dose rate irradiation may not only unravel the mechanisms of radiation-induced adverse brain effect or hormesis, but also provide clues for detection or diagnosis of radiation exposure and for therapeutic approaches to effectively prevent radiation-induced cognitive impairment and aging. Investigation focusing on radiation-induced changes of critical brain development events may reveal many previously unknown adverse effects.

  2. Neutron irradiation induced amorphization of silicon carbide

    SciTech Connect

    Snead, L.L.; Hay, J.C.

    1998-09-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 {times} 10{sup 25} n/m{sup 2}. Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density ({minus}10.8%), elastic modulus as measured using a nanoindentation technique ({minus}45%), hardness as measured by nanoindentation ({minus}45%), and standard Vickers hardness ({minus}24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C.

  3. Xylosylated-proteoglycan-induced Golgi alterations.

    PubMed Central

    Kanwar, Y S; Rosenzweig, L J; Jakubowski, M L

    1986-01-01

    The effect of p-nitrophenyl beta-D-xylopyranoside on the Golgi apparatus and proteoglycans (PG) of the renal glomerulus was investigated in an isolated kidney organ perfusion system and monitored by utilizing [35S]sulfate as the PG precursor. By electron microscopy, a selective intracytoplasmic vesiculization of Golgi apparatus of visceral epithelium was observed in the beta-xyloside-treated kidneys. Electron microscopic autoradiography revealed most grains localized to the intracytoplasmic Golgi-derived vesicles, while very few grains were associated with the extracellular matrix membranes. Biochemically, a 2.3-fold increase in cellular matrix and a reduction by a factor of 1.7 in extracellular matrix of [35S]sulfate incorporation was observed. Besides a larger macromolecular form (Kavg = 0.25; Mr = 130,000), lower molecular weight PGs were recovered in the cellular (Kavg = 0.46, Mr = 30,000) and matrical (Kavg = 0.42, Mr = 45,000) compartments after xyloside treatment. The xyloside treatment increased the incorporated radioactivity, mostly included in free glycosaminoglycans and small PGs, in the media fraction by 3.8-fold. These data indicate that xyloside induces a dramatic imbalance in the de novo-synthesized PGs of cellular and extracellular compartments and that cellular accumulation of xylosylated (sulfated) PGs selectively alters the Golgi apparatus of the glomerular epithelial cell, the cell that actively synthesizes PGs. Images PMID:3462708

  4. Abrogation of Early Apoptosis Does Not Alter Late Inhibition of Hippocampal Neurogenesis After Irradiation

    SciTech Connect

    Li Yuqing; Aubert, Isabelle; Wong, C. Shun

    2010-07-15

    Purpose: Irradiation of the adult brain results in acute apoptosis of neural progenitors and vascular endothelial cells, as well as late dysfunction of neural progenitors and inhibition of neurogenesis. We sought to determine whether the early apoptotic response has a causative role in late inhibition of neurogenesis after cranial irradiation. Methods and Materials: Using a genetic approach with p53 and smpd1 transgenic mice and a pharmacologic approach with basic fibroblast growth factor (bFGF) to abrogate the early apoptotic response, we evaluated the late inhibition of neurogenesis in the hippocampal dentate gyrus after cranial irradiation. Results: In dentate gyrus, subgranular neural progenitors underwent p53-dependent apoptosis within 24 h after irradiation. Despite a near abrogation of neural progenitor apoptosis in p53-/- mice, the reduction in newborn neurons in dentate gyrus at 9 weeks after irradiation in p53-/- mice was not different from that observed in wildtype controls. Endothelial cell apoptosis after radiation is mediated by membrane damage initiated by activation of acid sphingomyelinase (ASMase). Deletion of the smpd1 gene (which encodes ASMase) attenuated the apoptotic response of endothelial cells. At 9 weeks after irradiation, the inhibition of hippocampal neurogenesis was not rescued by ASMase deficiency. Intravenous administration of bFGF protected both endothelial cells and neural progenitors against radiation-induced apoptosis. There was no protection against inhibition of neurogenesis at 9 weeks after irradiation in bFGF-treated mice. Conclusion: Early apoptotic death of neural progenitors, endothelial cells, or both does not have a causative association with late inhibition of neurogenesis after irradiation.

  5. Neutron irradiation induced amorphization of silicon carbide

    NASA Astrophysics Data System (ADS)

    Snead, L. L.; Hay, J. C.

    1999-07-01

    This paper provides the properties of bulk stoichiometric silicon carbide which has been amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60°C to a total fast neutron fluence of 2.6 × 10 25 n/m 2. Amorphization was seen in both materials as evidenced by TEM, electron diffraction and X-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (-10.8%), elastic modulus as measured using a nanoindentation technique (-45%), hardness as measured by nanoindentation (-45%), and standard Vickers hardness (-24%). Similar property changes are observed for the amorphized CVD SiC. Using measured thermal conductivity data for the CVD SiC sample, the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than ˜125°C.

  6. Irradiation spectrum and ionization-induced diffusion effects in ceramics

    SciTech Connect

    Zinkle, S.J.

    1997-08-01

    There are two main components to the irradiation spectrum which need to be considered in radiation effects studies on nonmetals, namely the primary knock-on atom energy spectrum and ionizing radiation. The published low-temperature studies on Al{sub 2}O{sub 3} and MgO suggest that the defect production is nearly independent of the average primary knock-on atom energy, in sharp contrast to the situation for metals. On the other hand, ionizing radiation has been shown to exert a pronounced influence on the microstructural evolution of both semiconductors and insulators under certain conditions. Recent work on the microstructure of ion-irradiated ceramics is summarized, which provides evidence for significant ionization-induced diffusion. Polycrystalline samples of MgO, Al{sub 2}O{sub 3}, and MgAl{sub 2}O{sub 4} were irradiated with various ions ranging from 1 MeV H{sup +} to 4 MeV Zr{sup +} ions at temperatures between 25 and 650{degrees}C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructural of the irradiated specimens. Dislocation loop nucleation was effectively suppressed in specimens irradiated with light ions, whereas the growth rate of dislocation loops was enhanced. The sensitivity to irradiation spectrum is attributed to ionization-induced diffusion. The interstitial migration energies in MgAl{sub 2}O{sub 4} and Al{sub 2}O{sub 3} are estimated to be {le}0.4 eV and {le}0.8 eV, respectively for irradiation conditions where ionization-induced diffusion effects are expected to be negligible.

  7. Effects of Altered Levels of Extracellular Superoxide Dismutase and Irradiation on Hippocampal Neurogenesis in Female Mice

    SciTech Connect

    Zou, Yani; Leu, David; Chui, Jennifer; Fike, John R.; Huang, Ting-Ting

    2013-11-15

    Purpose: Altered levels of extracellular superoxide dismutase (EC-SOD) and cranial irradiation have been shown to affect hippocampal neurogenesis. However, previous studies were only conducted in male mice, and it was not clear if there was a difference between males and females. Therefore, female mice were studied and the results compared with those generated in male mice from an earlier study. Methods and Materials: Female wild-type, EC-SOD-null (KO), and EC-SOD bigenic mice with neuronal-specific expression of EC-SOD (OE) were subjected to a single dose of 5-Gy gamma rays to the head at 8 weeks of age. Progenitor cell proliferation, differentiation, and long-term survival of newborn neurons were determined. Results: Similar to results from male mice, EC-SOD deficiency and irradiation both resulted in significant reductions in mature newborn neurons in female mice. EC-SOD deficiency reduced long-term survival of newborn neurons whereas irradiation reduced progenitor cell proliferation. Overexpression of EC-SOD corrected the negative impacts from EC-SOD deficiency and irradiation and normalized the production of newborn neurons in OE mice. Expression of neurotrophic factors brain-derived neurotrophic factor and neurotrophin-3 were significantly reduced by irradiation in wild-type mice, but the levels were not changed in KO and OE mice even though both cohorts started out with a lower baseline level. Conclusion: In terms of hippocampal neurogenesis, EC-SOD deficiency and irradiation have the same overall effects in males and females at the age the studies were conducted.

  8. DNA damage response induces structural alterations in histone H3–H4

    PubMed Central

    Izumi, Yudai; Fujii, Kentaro; Yamamoto, Satoshi; Matsuo, Koichi; Namatame, Hirofumi; Taniguchi, Masaki; Yokoya, Akinari

    2017-01-01

    Synchrotron-radiation circular-dichroism spectroscopy was used to reveal that the DNA damage response induces a decrement of α-helix and an increment of β-strand contents of histone H3–H4 extracted from X-ray–irradiated human HeLa cells. The trend of the structural alteration was qualitatively opposite to that of our previously reported results for histone H2A–H2B. These results strongly suggest that histones share roles in DNA damage responses, particularly in DNA repair processes and chromatin remodeling, via a specific structural alteration of each histone. PMID:27672100

  9. Gastroprotective effect of kefir on ulcer induced in irradiated rats.

    PubMed

    Fahmy, Hanan A; Ismail, Amel F M

    2015-03-01

    The current study was designed to investigate the protective effect of kefir milk on ethanol-induced gastric ulcers in γ-irradiated rats. The results of the present study revealed that treatment with γ-irradiation and/or ethanol showed a significant increase in ulcers number, total acidity, peptic, H(+)K(+)ATPase, MMP-2 and MMP-9 activities and MDA level, which were accompanied by a significant decrease in the mucus content, the stomach GSH level, the GSH-Px activity and DNA damage. Pre-treatment with kefir milk exert significant improvement in all the tested parameters. Kefir milk exerts comparable effect to that of the antiulcer drug ranitidine. In conclusion, the present study revealed that oral administration of kefir milk prevents ethanol-induced gastric ulcer in γ-irradiated rats that could attribute to its antioxidant, anti-apoptotic and radio-protective activities.

  10. A preclinical rodent model of acute radiation-induced lung injury after ablative focal irradiation reflecting clinical stereotactic body radiotherapy.

    PubMed

    Hong, Zhen-Yu; Lee, Hae-June; Choi, Won Hoon; Lee, Yoon-Jin; Eun, Sung Ho; Lee, Jung Il; Park, Kwangwoo; Lee, Ji Min; Cho, Jaeho

    2014-07-01

    In a previous study, we established an image-guided small-animal micro-irradiation system mimicking clinical stereotactic body radiotherapy (SBRT). The goal of this study was to develop a rodent model of acute phase lung injury after ablative irradiation. A radiation dose of 90 Gy was focally delivered to the left lung of C57BL/6 mice using a small animal stereotactic irradiator. At days 1, 3, 5, 7, 9, 11 and 14 after irradiation, the lungs were perfused with formalin for fixation and paraffin sections were stained with hematoxylin and eosin (H&E) and Masson's trichrome. At days 7 and 14 after irradiation, micro-computed tomography (CT) images of the lung were taken and lung functional measurements were performed with a flexiVent™ system. Gross morphological injury was evident 9 days after irradiation of normal lung tissues and dynamic sequential events occurring during the acute phase were validated by histopathological analysis. CT images of the mouse lungs indicated partial obstruction located in the peripheral area of the left lung. Significant alteration in inspiratory capacity and tissue damping were detected on day 14 after irradiation. An animal model of radiation-induced lung injury (RILI) in the acute phase reflecting clinical stereotactic body radiotherapy was established and validated with histopathological and functional analysis. This model enhances our understanding of the dynamic sequential events occurring in the acute phase of radiation-induced lung injury induced by ablative dose focal volume irradiation.

  11. Nature of nontargeted radiation effects observed during fractionated irradiation-induced thymic lymphomagenesis in mice.

    PubMed

    Tsuji, Hideo; Ishii-Ohba, Hiroko; Shiomi, Tadahiro; Shiomi, Naoko; Katsube, Takanori; Mori, Masahiko; Nenoi, Mitsuru; Ohno, Mizuki; Yoshimura, Daisuke; Oka, Sugako; Nakabeppu, Yusaku; Tatsumi, Kouichi; Muto, Masahiro; Sado, Toshihiko

    2013-05-01

    Changes in the thymic microenvironment lead to radiation-induced thymic lymphomagenesis, but the phenomena are not fully understood. Here we show that radiation-induced chromosomal instability and bystander effects occur in thymocytes and are involved in lymphomagenesis in C57BL/6 mice that have been irradiated four times with 1.8-Gy γ-rays. Reactive oxygen species (ROS) were generated in descendants of irradiated thymocytes during recovery from radiation-induced thymic atrophy. Concomitantly, descendants of irradiated thymocytes manifested DNA lesions as revealed by γ-H2AX foci, chromosomal instability, aneuploidy with trisomy 15 and bystander effects on chromosomal aberration induction in co-cultured ROS-sensitive mutant cells, suggesting that the delayed generation of ROS is a primary cause of these phenomena. Abolishing the bystander effect of post-irradiation thymocytes by superoxide dismutase and catalase supports ROS involvement. Chromosomal instability in thymocytes resulted in the generation of abnormal cell clones bearing trisomy 15 and aberrant karyotypes in the thymus. The emergence of thymic lymphomas from the thymocyte population containing abnormal cell clones indicated that clones with trisomy 15 and altered karyotypes were prelymphoma cells with the potential to develop into thymic lymphomas. The oncogene Notch1 was rearranged after the prelymphoma cells were established. Thus, delayed nontargeted radiation effects drive thymic lymphomagenesis through the induction of characteristic changes in intrathymic immature T cells and the generation of prelymphoma cells.

  12. Early stages of irradiation induced dislocations in urania

    NASA Astrophysics Data System (ADS)

    Chartier, A.; Onofri, C.; Van Brutzel, L.; Sabathier, C.; Dorosh, O.; Jagielski, J.

    2016-10-01

    The early stages of nucleation and growth of dislocations by irradiation in urania is clarified based on the combination of experiments and atomistic calculations. It is established that irradiation induced dislocations follow a five stage process: (i) point defects are first created by irradiation, (ii) they aggregate into clusters, (iii) from which nucleate Frank loops, (iv) which transform into unfaulted loops via Shockley that in turn grow, and (v) finally reorganize into forest dislocations. Stages (i)-(iii) participate in the lattice expansion while the onset of lattice contraction starts with stage (iv), i.e., when unfaulted loops nucleate. Irradiation induced dislocations operate in the spontaneous recombination regime, to be opposed to the thermal diffusion regime. Body of arguments collaborates to this statement, the main one is the comparison between characteristic distances estimated from the dose rate (Vat/(K0×τ ) ) 1/3 and from the diffusion coefficient (D×τ ) 1/2 . Such a comparison identifies materials under irradiation as belonging either into the recombination regime or not.

  13. Influence of absorption induced thermal initiation pathway on irradiance threshold for laser induced breakdown

    PubMed Central

    Varghese, Babu; Bonito, Valentina; Jurna, Martin; Palero, Jonathan; Verhagen, Margaret Hortonand Rieko

    2015-01-01

    We investigated the influence of thermal initiation pathway on the irradiance threshold for laser induced breakdown in transparent, absorbing and scattering phantoms. We observed a transition from laser-induced optical breakdown to laser-induced thermal breakdown as the absorption coefficient of the medium is increased. We found that the irradiance threshold after correction for the path length dependent absorption and scattering losses in the medium is lower due to the thermal pathway for the generation of seed electrons compared to the laser-induced optical breakdown. Furthermore, irradiance threshold gradually decreases with the increase in the absorption properties of the medium. Creating breakdown with lower irradiance threshold that is specific at the target chromophore can provide intrinsic target selectivity and improve safety and efficacy of skin treatment methods that use laser induced breakdown. PMID:25909007

  14. Irradiation enhances dendritic cell potential antitumor activity by inducing tumor cell expressing TNF-α.

    PubMed

    Chang, Lijia; Zhang, Zhengzheng; Chen, Fang; Zhang, Wen; Song, Shuang; Song, Shuxia

    2017-03-01

    Dendritic cells (DCs)-based tumor vaccines have shown to be the promising methods for inducing therapeutic antitumor response. However, DCs alone rarely carry curative antitumor activity, and the immunosuppressive microenvironment may contribute to this defect of DC vaccinal function. Irradiation in combination with DCs has been shown to promote immune-mediated tumor destruction in preclinical studies. However, little is known about how irradiation alters the tumor microenvironment, and what host pathways modulate the activity of administrated DCs. In this study, BALB/c mice and the 4T1 breast cancer cell line were used in a tumor-bearing model. The tumor-bearing mice were irradiated locally up to 10 Gy for 3 consecutive days or a single dose of 30 Gy using a cesium source. Studies of dynamic change of the tumor microenvironment in irradiated versus untreated tumors revealed that there was no obvious change on IL-10, IL-6 and TGF-β expression or production, whereas increased TNF-α level within the first 2 weeks of irradiation. The increased TNF-α level is exactly right timing window for DCs injection, corresponding to the significant elevation of intratumoral CD8(+) T infiltration and the regression of tumor size. With attention to scheduling, combination X-ray with DCs i.t. injection may offer a practical strategy to improve treatment outcomes.

  15. Genetic Background Modulates Gene Expression Profile Induced by Skin Irradiation in Ptch1 Mice

    SciTech Connect

    Galvan, Antonella; Noci, Sara; Mancuso, Mariateresa; Pazzaglia, Simonetta; Saran, Anna; Dragani, Tommaso A.

    2008-12-01

    Purpose: Ptch1 germ-line mutations in mice predispose to radiation-induced basal cell carcinoma of the skin, with tumor incidence modulated by the genetic background. Here, we examined the possible mechanisms underlying skin response to radiation in F1 progeny of Ptch1{sup neo67/+} mice crossed with either skin tumor-susceptible (Car-S) or -resistant (Car-R) mice and X-irradiated (3 Gy) at 2 days of age or left untreated. Methods and Materials: We conducted a gene expression profile analysis in mRNA samples extracted from the skin of irradiated or control mice, using Affymetrix whole mouse genome expression array. Confirmation of the results was done using real-time reverse-transcriptase polymerase chain reaction. Results: Analysis of the gene expression profile of normal skin of F1 mice at 4 weeks of age revealed a similar basal profile in the nonirradiated mice, but alterations in levels of 71 transcripts in irradiated Ptch1{sup neo67/+} mice of the Car-R cross and modulation of only eight genes in irradiated Ptch1{sup neo67/+} mice of the Car-S cross. Conclusions: These results indicate that neonatal irradiation causes a persistent change in the gene expression profile of the skin. The tendency of mice genetically resistant to skin tumorigenesis to show a more complex pattern of transcriptional response to radiation than do genetically susceptible mice suggests a role for this response in genetic resistance to basal cell tumorigenesis.

  16. Modulation of radiation-induced alteration in the antioxidant status of mice by naringin.

    PubMed

    Jagetia, Ganesh Chandra; Reddy, Tiyyagura Koti

    2005-07-01

    The alteration in the antioxidant status and lipid peroxidation was investigated in Swiss albino mice treated with 2 mg/kg b.wt. naringin, a citrus flavoglycoside, before exposure to 0.5, 1, 2, 3, and 4 Gy gamma radiation. Lipid peroxidation, glutathione, glutathione peroxidase, catalase and superoxide dismutase were determined in the liver and small intestine of mice treated or not with naringin at 0.5, 1, 2, 4 and 8 h post-irradiation. Whole-body irradiation of mice caused a dose-dependent elevation in the lipid peroxidation while a dose-dependent depletion was observed for glutathione, glutathione peroxidase, superoxide dismutase and catalase in both liver as well as small intestine. Treatment of mice with 2 mg/kg b. wt. naringin inhibited the radiation-induced elevation in the lipid peroxidation as well as depletion of glutathione, glutathione peroxidase, superoxide dismutase and catalase in liver and small intestine. Radiation-induced lipid peroxidation increased with time, which was greatest at 2 h post-irradiation and declined thereafter in the liver and small intestine. Similarly, a maximum decline in the glutathione glutathione peroxidase, and superoxide dismutase was observed at 1 h, while catalase showed a maximum decline at 2 h post-irradiation. Our study demonstrates that naringin protects mouse liver and intestine against the radiation-induced damage by elevating the antioxidant status and reducing the lipid peroxidation.

  17. Solar ultraviolet irradiation induces decorin degradation in human skin likely via neutrophil elastase.

    PubMed

    Li, Yong; Xia, Wei; Liu, Ying; Remmer, Henriette A; Voorhees, John; Fisher, Gary J

    2013-01-01

    Exposure of human skin to solar ultraviolet (UV) irradiation induces matrix metalloproteinase-1 (MMP-1) activity, which degrades type I collagen fibrils. Type I collagen is the most abundant protein in skin and constitutes the majority of skin connective tissue (dermis). Degradation of collagen fibrils impairs the structure and function of skin that characterize skin aging. Decorin is the predominant proteoglycan in human dermis. In model systems, decorin binds to and protects type I collagen fibrils from proteolytic degradation by enzymes such as MMP-1. Little is known regarding alterations of decorin in response to UV irradiation. We found that solar-simulated UV irradiation of human skin in vivo stimulated substantial decorin degradation, with kinetics similar to infiltration of polymorphonuclear (PMN) cells. Proteases that were released from isolated PMN cells degraded decorin in vitro. A highly selective inhibitor of neutrophil elastase blocked decorin breakdown by proteases released from PMN cells. Furthermore, purified neutrophil elastase cleaved decorin in vitro and generated fragments with similar molecular weights as those resulting from protease activity released from PMN cells, and as observed in UV-irradiated human skin. Cleavage of decorin by neutrophil elastase significantly augmented fragmentation of type I collagen fibrils by MMP-1. Taken together, these data indicate that PMN cell proteases, especially neutrophil elastase, degrade decorin, and this degradation renders collagen fibrils more susceptible to MMP-1 cleavage. These data identify decorin degradation and neutrophil elastase as potential therapeutic targets for mitigating sun exposure-induced collagen fibril degradation in human skin.

  18. Irradiation-induced effects of proton irradiation on zirconium carbides with different stoichiometries

    SciTech Connect

    Y. Huang; B.R. Maier; T.R. Allen

    2014-10-01

    Zirconium carbide (ZrC) is being considered for utilization in deep burn TRISO fuel particles for hightemperature, gas-cooled reactors. Zirconium carbide has a cubic B1 type crystal structure along with a very high melting point (3420 ?C), exceptional hardness and good thermal and electrical conductivities. Understanding the ZrC irradiation response is crucial for establishing ZrC as an alternative component in TRISO fuel. Until now, very few studies on irradiation effects on ZrC have been released and fundamental aspects of defect evolution and kinetics are not well understood although some atomistic simulations and phenomenological studies have been performed. This work was carried out to understand the damage evolution in float-zone refined ZrC with different stoichiometries. Proton irradiations at 800 ?C up to doses of 3 dpa were performed on ZrCx (where x ranges from 0.9 to 1.2) to investigate the damage evolution. The irradiation-induced defects, such as density of dislocation loops, at different stoichiometries and doses which were characterized by transmission electron microscopy (TEM) is presented and discussed.

  19. Universal edge bands induced by linearly polarized irradiation on phosphorene

    NASA Astrophysics Data System (ADS)

    Yang, Mou; Zhang, Wen-Lian; Cai, Zhi-Jun; Wang, Rui-Qiang; Bai, Yan-Kui

    2017-01-01

    Phosphorene (a monolayer of black phosphorus) is a large gap semiconductor with high mobility and has great application potential. Numerical calculations reveal that phosphorene is a topologically trivial material and can only host edge bands on specified edges such as the zigzag edge. A linearly polarized irradiation on the phosphorene lattice results in the dynamic gaps in the quasi-energy spectrum. We found that the irradiation polarized in the zigzag direction induces new edge bands within the dynamic gaps on any type of edge (zigzag, armchair, or other bearded edge). We proposed a new gauge independent quantity, δ +g, to account for the appearence of universal edge bands, where δ is the detune and g is the light induced valence-conduction band transition element. The number of edge bands in the dynamic gaps is reflected by the winding number of it.

  20. Prenatal irradiation-induced brain neuropathology and cognitive impairment.

    PubMed

    Yang, Bo; Ren, Bo Xu; Tang, Feng Ru

    2017-01-01

    Embryo/fetus is much more radiosensitive than neonatal and adult human being. The main potential effects of pre-natal radiation exposure on the human brain include growth retardation, small head/brain size, mental retardation, neocortical ectopias, callosal agenesis and brain tumor which may result in a lifetime poor quality of life. The patterns of prenatal radiation-induced effects are dependent not only on the stages of fetal development, the sensitivity of tissues and organs, but also on radiation sources, doses, dose rates. With the increased use of low dose radiation for diagnostic or radiotherapeutic purposes in recent years, combined with postnatal negative health effect after prenatal radiation exposure to fallout of Chernobyl nuclear power plant accident, the great anxiety and unnecessary termination of pregnancies after the nuclear disaster, there is a growing concern about the health effect of radiological examinations or therapies in pregnant women. In this paper, we reviewed current research progresses on pre-natal ionizing irradiation-induced abnormal brain structure changes. Subsequent postnatal neuropsychological and neurological diseases were provided. Relationship between irradiation and brain aging was briefly mentioned. The relevant molecular mechanisms were also discussed. Future research directions were proposed at the end of this paper. With limited human data available, we hoped that systematical review of animal data could relight research interests on prenatal low dose/dose rate irradiation-induced brain microanatomical changes and subsequent neurological and neuropsychological disorders.

  1. A Mouse Model of Fatigue Induced by Peripheral Irradiation.

    PubMed

    Wolff, Brian S; Renner, Michael A; Springer, Danielle A; Saligan, Leorey N

    2017-03-17

    Cancer-related fatigue (CRF) is a distressing and costly condition that often affects patients receiving cancer treatments, including radiation therapy. Here we describe a method using targeted peripheral irradiation to induce fatigue-like behavior in mice. With appropriate shielding, the irradiation targets the lower abdominal/pelvic region of the mouse, sparing the brain, in an effort to model radiation treatment received by individuals with pelvic cancers. We deliver an irradiation dose that is sufficient to induce fatigue-like behavior in mice, measured by voluntary wheel-running activity (VWRA), without causing obvious morbidity. Since wheel running is a normal, voluntary behavior in mice, its use should have little confounding effect on other behavioral tests or biological measures. Hence, wheel running can be used as a feasible outcome measure in understanding the behavioral and biological correlates of fatigue. CRF is a complex condition with frequent comorbidities, and likely has causes related both to cancer and its various treatments. The methods described in this paper are useful for investigating radiation-induced changes that contribute to the development of CRF and, more generally, to explore the biological networks that can explain the development and persistence of a peripherally-triggered but centrally-driven behavior like fatigue.

  2. Efavirenz Induces Neuronal Autophagy and Mitochondrial Alterations

    PubMed Central

    Purnell, Phillip R.

    2014-01-01

    Efavirenz (EFV) is a non-nucleoside reverse-transcriptase inhibitor in wide use for the treatment of human immunodeficiency virus infection. Although EFV is generally well tolerated, neuropsychiatric toxicity has been well documented. The toxic effects of EFV in hepatocytes and keratinocytes have been linked to mitochondrial perturbations and changes in autophagy. Here, we studied the effect of EFV on mitochondria and autophagy in neuronal cell lines and primary neurons. In SH-SY5Y cells, EFV induced a drop in ATP production, which coincided with increased autophagy, mitochondrial fragmentation, and mitochondrial depolarization. EFV-induced mitophagy was also detected by colocalization of mitochondria and autophagosomes and use of an outer mitochondrial membrane tandem fluorescent vector. Pharmacologic inhibition of autophagy with 3-methyladenine increased the cytotoxic effect of EFV, suggesting that autophagy promotes cell survival. EFV also reduces ATP production in primary neurons, induces autophagy, and changes mitochondrial morphology. Overall, EFV is able to acutely induce autophagy and mitochondrial changes in neurons. These changes may be involved in the mechanism leading to central nervous system toxicity observed in clinical EFV use. PMID:25161171

  3. Laser-induced alteration of contaminated papers

    NASA Astrophysics Data System (ADS)

    Rudolph, P.; Ligterink, F. J.; Pedersoli, J. L., Jr.; Scholten, H.; Schipper, D.; Havermans, J. B. G. A.; Aziz, H. A.; Quillet, V.; Kraan, M.; van Beek, B.; Corr, S.; Hua-Ströfer, H.-Y.; Stokmans, J.; Dalen, P. van; Kautek, W.

    Cleaning of paper objects represents one of the most complex cases of laser ablation, since low volumes of dispersed material phases are evaporated while a sensitive and fragile fibrous organic matrix has to be preserved. Conventional chemical and mechanical cleaning methods suffer from the common phenomenon that the foreign matter is diluted into the substrate rather than removed. The application of a laser beam allows highly localized and optically specific interaction. However, the occurrence of extreme temperatures and light intensities may cause irreversible alteration of the paper matrix. Further, incomplete removal and/or chemical conversion of contaminations may result in insufficient cleaning or affect the ageing behaviour. Laser treatments were performed by Q-switched Nd:YAG lasers at three wavelengths (355 nm, 532 nm, and 1064 nm). Papers contaminated with inks and adhesive-tape remnants served as model samples. Multispectral imaging and colorimetric results served to quantify and systematize the results.

  4. Irradiation-induced patterning in dilute Cu-Fe alloys

    NASA Astrophysics Data System (ADS)

    Stumphy, B.; Chee, S. W.; Vo, N. Q.; Averback, R. S.; Bellon, P.; Ghafari, M.

    2014-10-01

    Compositional patterning in dilute Cu1-xFex (x ≈ 12%) induced by 1.8 MeV Kr+ irradiation was studied as a function of temperature using atom probe tomography. Irradiation near room temperature led to homogenization of the sample, whereas irradiation at 300 °C and above led to precipitation and macroscopic coarsening. Between these two temperatures the irradiated alloys formed steady state patterns of composition where precipitates grew to a fixed size. The size in this regime increased somewhat with temperature. It was also observed that the steady state concentrations of Fe in Cu matrix and Cu in the Fe precipitates both greatly exceeded their equilibrium solubilities, with the degree of supersaturation in each phase decreasing with increasing temperature. In the macroscopic coarsening regime, the Fe-rich precipitates showed indications of a “cherry-pit” structure, with Cu precipitates forming within the Fe precipitates. In the patterning regime, interfaces between Fe-rich precipitates and the Cu-rich matrix were irregular and diffuse.

  5. Anatomical alterations of Phaseolus vulgaris L. mature leaves irradiated with X-rays.

    PubMed

    De Micco, V; Arena, C; Aronne, G

    2014-01-01

    The cultivation of higher plants in Space involves not only the development of new agro-technologies for the design of ecologically closed Space greenhouses, but also understanding of the effects of Space factors on biological systems. Among Space factors, ionising radiation is one of the main constraints to the growth of organisms. In this paper, we analyse the effect of low-LET radiation on leaf histology and cytology in Phaseolus vulgaris L. plants subjected to increasing doses of X-rays (0.3, 10, 50, 100 Gy). Leaves irradiated at tissue maturity were compared with not-irradiated controls. Semi-thin sections of leaves were analysed through light and epi-fluorescence microscopy. Digital image analysis was applied to quantify anatomical parameters, with a specific focus on the occurrence of signs of structural damage as well as alterations at subcellular level, such as the accumulation of phenolic compounds and chloroplast size. Results showed that even at high levels of radiation, general anatomical structure was not severely perturbed. Slight changes in mesophyll density and cell enlargement were detected at the highest level of radiation. However, at 100 Gy, higher levels of phenolic compounds accumulated along chloroplast membranes: this accompanied an increase in number of chloroplasts. The reduced content of chlorophylls at high levels of radiation was associated with reduced size of the chloroplasts. All data are discussed in terms of the possible role of cellular modifications in the maintenance of high radioresistance and photosynthetic efficiency.

  6. Epigenetic Alterations Induced by Bacterial Lipopolysaccharides.

    PubMed

    Chiariotti, Lorenzo; Coretti, Lorena; Pero, Raffaela; Lembo, Francesca

    2016-01-01

    Lipopolysaccharide (LPS) is one of the principal bacterial products known to elicit inflammation. Cells of myeloid lineage such as monocytes and macrophages, but also epithelial cells give rise to an inflammatory response upon LPS stimulation. This phenomenon implies reprogramming of cell specific gene expression that can occur through different mechanisms including epigenetic modifications. Given their intrinsic nature, epigenetic modifications may be involved both in the acute response to LPS and in the establishment of a preconditioned genomic state (epigenomic memory) that may potentially influence the host response to further contacts with microorganisms. Information has accumulated during the last years aimed at elucidating the epigenetic mechanisms which underlie the cellular LPS response. These findings, summarized in this chapter, will hopefully be a good basis for a definition of the complete cascade of LPS-induced epigenetic events and their biological significance in different cell types.

  7. Irradiation induced structural change in Mo2Zr intermetallic phase

    DOE PAGES

    Gan, J.; Keiser, Jr., D. D.; Miller, B. D.; ...

    2016-05-14

    The Mo2Zr phase has been identified as a major interaction product at the interface of U-10Mo and Zr. Transmission electron microscopy in-situ irradiation with Kr ions at 200 °C with doses up to 2.0E+16 ions/cm2 was carried out to investigate the radiation stability of the Mo2Zr. The Mo2Zr undergoes a radiation-induced structural change, from a large cubic (cF24) to a small cubic (cI2), along with an estimated 11.2% volume contraction without changing its composition. The structural change begins at irradiation dose below 1.0E+14 ions/cm2. Furthermore, the transformed Mo2Zr phase demonstrates exceptional radiation tolerance with the development of dislocations without bubblemore » formation.« less

  8. Cytogenetic Alterations in Preimplantation Mice Embryos Following Male Mouse Gonadal Gamma-irradiation: Comparison of Two Methods for Reproductive Toxicity Screening

    PubMed Central

    Salimi, Mahdieh; Mozdarani, Hossein; Nazari, Elmina

    2014-01-01

    Background Genome instability is a main cause of chromosomal alterations in both somatic and germ cells when exposed to environmental, physical and chemical genotoxicants. Germ cells especially spermatozoa are more vulnerable to suffering from DNA damaging agents during spermatogenesis and also more potent in transmitting genome instability to next generation. Methods To investigate the effects of γ-rays on inducing abnormalities manifested as numerical Chromosome Aberrations (CA) and Micronucleus (MN) in preimplantation embryos, adult male NMRI mice were irradiated with 4 Gy of γ-rays. They were then mated at weekly intervals with superovulated, non-irradiated female mice in 6 successive weeks. About 68 hr post coitous, four to eight cell embryos were retrieved and fixed on slides using standard methods in order to screen for CA and MN. Results In embryos generated from irradiated mice, the frequency of aneuploidy and MN increased dramatically at all post-irradiation sampling times as compared to the control (p<0.01). The frequency of embryos expressed MN was much higher than chromosomally abnormal embryos, although the trend of MN formation was similar to chromosomal abnormalities seen in corresponding sampling times. Conclusion Irradiation of sperms at any stages of spermatogenesis may lead to stable chromosomal abnormalities affecting pairing and disjunction of chromosomes in successive preimplantation embryos that are expressed as MN. Although chromosome analysis of embryos showed various types of chromosomal abnormalities, MN assay provide a simpler and faster technique for investigating the genotoxicity of agents affecting embryos at preimplantation stages. PMID:25215176

  9. Tolerance development to cadmium-induced alteration of drug action.

    PubMed

    Roberts, S A; Miya, T S; Schnell, R C

    1976-05-01

    Cadmium administration potentiates the duration of hexobarbital-induced hypnosis and inhibits the rate of hepatic microsomal metabolism of this drug in the male rat. The threshold dose of cadmium required to produce these alterations in drug action is 0.84 mg Ck/kg. If subthreshold doses of cadmium (0.21 or 0.42 mg Cd/kg) are administered prior to the 0.84 mg Cd/kg dose, the cadmium-induced alterations in drug action are no longer observed.

  10. Ultraviolet irradiation induces the accumulation of chondroitin sulfate, but not other glycosaminoglycans, in human skin.

    PubMed

    Werth, Benjamin Boegel; Bashir, Muhammad; Chang, Laura; Werth, Victoria P

    2011-01-01

    Ultraviolet (UV) light alters cutaneous structure and function. Prior work has shown loss of dermal hyaluronan after UV-irradiation of human skin, yet UV exposure increases total glycosaminoglycan (GAG) content in mouse models. To more fully describe UV-induced alterations to cutaneous GAG content, we subjected human volunteers to intermediate-term (5 doses/week for 4 weeks) or single-dose UV exposure. Total dermal uronyl-containing GAGs increased substantially with each of these regimens. We found that UV exposure substantially increased dermal content of chondroitin sulfate (CS), but not hyaluronan, heparan sulfate, or dermatan sulfate. UV induced the accumulation of both the 4-sulfated (C4S) and 6-sulfated (C6S) isoforms of CS, but in distinct distributions. Next, we examined several CS proteoglycan core proteins and found a significant accumulation of dermal and endothelial serglycin, but not of decorin or versican, after UV exposure. To examine regulation in vitro, we found that UVB in combination with IL-1α, a cytokine upregulated by UV radiation, induced serglycin mRNA in cultured dermal fibroblasts, but did not induce the chondroitin sulfate synthases. Overall, our data indicate that intermediate-term and single-dose UVB exposure induces specific GAGs and proteoglycan core proteins in human skin in vivo. These molecules have important biologic functions and contribute to the cutaneous response to UV.

  11. Defect-induced magnetism in graphite through neutron irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Yutian; Pochet, Pascal; Jenkins, Catherine A.; Arenholz, Elke; Bukalis, Gregor; Gemming, Sibylle; Helm, Manfred; Zhou, Shengqiang

    2014-12-01

    We have investigated the variation in the magnetization of highly ordered pyrolytic graphite (HOPG) after neutron irradiation, which introduces defects in the bulk sample and consequently gives rise to a large magnetic signal. We observe strong paramagnetism in HOPG, increasing with the neutron fluence. The induced paramagnetism can be well correlated with structural defects by comparison with density-functional theory calculations. In addition to the in-plane vacancies, the transplanar defects also contribute to the magnetization. The lack of any magnetic order between the local moments is possibly due to the absence of hydrogen/nitrogen chemisorption, or the magnetic order cannot be established at all in the bulk form.

  12. Study of neutron irradiation-induced colors in Brazilian topaz

    NASA Astrophysics Data System (ADS)

    Leal, A. S.; Krambrock, K.; Ribeiro, L. G. M.; Menezes, M. Â. B. C.; Vermaercke, P.; Sneyers, L.

    2007-09-01

    In this work, preliminary results of the investigation of the coloring mechanisms in topaz from different regions of Brazil, irradiated by the TRIGA MARK I IPR-R1 and BR1 nuclear reactors of the CDTN/CNEN (Brazil) and SCK.CEN(Belgium), respectively, are presented . The samples were analyzed by the k0-NAA method for impurities and total activity. The color and color centers were investigated by optical absorption and electron paramagnetic resonance (EPR) spectroscopy. The total integrated flux dependence of the induced blue colors and color centers is discussed.

  13. Polymer hydrophilicity and hydrophobicity induced by femtosecond laser direct irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Z. K.; Zheng, H. Y.; Lim, C. P.; Lam, Y. C.

    2009-09-01

    Controlled modification of surface wettability of polymethyl methacrylate (PMMA) was achieved by irradiation of PMMA surface with femtosecond laser pulses at various laser fluences and focus distances. Fluences from 0.40 to 2.1 J/cm2 produced a hydrophobic surface and 2.1 to 52.7 J/cm2 (maximum investigated) produced a hydrophilic surface. Fluences less than 0.31 J/cm2 had no effect on the wettability of the raw PMMA. This change in wettability was caused dominantly by laser induced chemical structure modification and not by a change in surface roughness.

  14. Irradiation-induced amorphization of AlPO 4

    NASA Astrophysics Data System (ADS)

    Sreeram, A. N.; Hobbs, L. W.; Bordes, N.; Ewing, R. C.

    1996-08-01

    AlPO 4, in the mineral form berlinite, is isostructural with α-quartz. We have investigated the irradiation-induced amorphization of hydrothermally-grown berlinite and found that — like quartz and other silicas but unlike most other phosphates — it undergoes solid-state radiolyis, with an efficiency fifty times that of quartz at room temperature, and amorphizes at an absorbed ionization dose of about 1 GGy. High-resolution TEM revealed that — unlike quartz in which small amorphous inclusions nucleate — electron-irradiated AlPO 4 proceeds uniformly to an aperiodic state, much as do cristobalite and tridymite, and 20 times faster. It was found also to amorphize under 1.5 MeV Kr + ion irradiation at a collisional energy density (10 eV/atom) similar to that for quartz and in keeping with the degree of structural freedom afforded by its tetrahedral network structure. The critical ion fluence for amorphization was found to increase by a factor of 5 between 300 and 600 K. Radial distribution functions derived from energy-filtered electron diffraction patterns from regions amorphized by electrons resemble those of electron-amorphized quartz with some additional features.

  15. Hydrogen-Rich Water Ameliorates Total Body Irradiation-Induced Hematopoietic Stem Cell Injury by Reducing Hydroxyl Radical

    PubMed Central

    Xue, Xiaolei; Han, Xiaodan; Li, Yuan; Lu, Lu; Li, Deguan

    2017-01-01

    We examined whether consumption of hydrogen-rich water (HW) could ameliorate hematopoietic stem cell (HSC) injury in mice with total body irradiation (TBI). The results indicated that HW alleviated TBI-induced HSC injury with respect to cell number alteration and to the self-renewal and differentiation of HSCs. HW specifically decreased hydroxyl radical (∙OH) levels in the c-kit+ cells of 4 Gy irradiated mice. Proliferative bone marrow cells (BMCs) increased and apoptotic c-kit+ cells decreased in irradiated mice uptaken with HW. In addition, the mean fluorescence intensity (MFI) of γ-H2AX and percentage of 8-oxoguanine positive cells significantly decreased in HW-treated c-kit+ cells, indicating that HW can alleviate TBI-induced DNA damage and oxidative DNA damage in c-kit+ cells. Finally, the cell cycle (P21), cell apoptosis (BCL-XL and BAK), and oxidative stress (NRF2, HO-1, NQO1, SOD, and GPX1) proteins were significantly altered by HW in irradiated mouse c-kit+ cells. Collectively, the present results suggest that HW protects against TBI-induced HSC injury. PMID:28243358

  16. Selective Induced Altered Coccidians to Immunize and Prevent Enteritis

    PubMed Central

    2016-01-01

    Microbiomic flora in digestive tract is pivotal to the state of our health and disease. Antibiotics affect GI, control composition of microbiome, and shift equilibrium from health into disease status. Coccidiosis causes gastrointestinal inflammation. Antibiotic additives contaminate animal products and enter food chain, consumed by humans with possible allergic, antibiotic resistance and enigmatic side effects. Purposed study induced nonpathogenic, immunogenic organisms to protect against disease and abolish antibiotics' use in food animals and side effects in man. Diverse species of Coccidia were used as model. Immature organisms were treated with serial purification procedure prior to developmental stages to obtain altered strains. Chicks received oral gavage immunized with serial low doses of normal or altered organisms or sham treatment and were challenged with high infective normal organisms to compare pathogenicity and immunogenicity. Mature induced altered forms of E. tenella and E. necatrix lacked developmental stage of “sporocysts” and contained free sporozoites. In contrast, E. maxima progressed to normal forms or did not mature at all. Animals that received altered forms were considerably protected with higher weight gain and antibody titers against challenge infection compared to those that received normal organisms (p < 0.05). This is the first report to induce selected protective altered organisms for possible preventive measures to minimize antibiotic use in food animals. PMID:27721824

  17. Bystander Effects Induced by Medium From Irradiated Cells: Similar Transcriptome Responses in Irradiated and Bystander K562 Cells

    SciTech Connect

    Herok, Robert; Konopacka, Maria; Polanska, Joanna; Swierniak, Andrzej; Rogolinski, Jacek; Jaksik, Roman; Hancock, Ronald; Rzeszowska-Wolny, Joanna

    2010-05-01

    Purpose: Cells exposed to ionizing radiation release factors that induce deoxyribonucleic acid damage, chromosomal instability, apoptosis, and changes in the proliferation rate of neighboring unexposed cells, phenomena known as bystander effects. This work analyzes and compares changes in global transcript levels induced by direct irradiation and by bystander effects in K562 (human erythroleukemia) cells. Methods and Materials: Cells were X-irradiated with 4 Gy or transferred into culture medium collected from cells 1 h after irradiation (irradiation-conditioned medium). Global transcript profiles were assessed after 36 h of growth by use of Affymetrix microarrays (Affymetrix, Santa Clara, CA) and the kinetics of change of selected transcripts by quantitative reverse transcriptase-polymerase chain reaction. Results: The level of the majority (72%) of transcripts changed similarly (increase, decrease, or no change) in cells grown in irradiation-conditioned medium or irradiated, whereas only 0.6% showed an opposite response. Transcript level changes in bystander and irradiated cells were significantly different from those in untreated cells grown for the same amount of time and were confirmed by quantitative reverse transcriptase-polymerase chain reaction for selected genes. Signaling pathways in which the highest number of transcripts changed in both conditions were found in the following groups: neuroactive ligand-receptor, cytokine-cytokine receptor interaction, Janus Kinase-Signal Transducers and Activators of Transcription (JAK-STAT) and Mitogen-Activated Protein Kinase (MAPK) In control cells more transcripts were downregulated than in irradiated and bystander cells with transcription factors YBX1 and STAT5B, heat shock protein HSPA1A, and ribonucleic acid helicase DDX3X as examples. Conclusions: The transcriptomes of cells grown in medium from X-irradiated cells or directly irradiated show very similar changes. Signals released by irradiated cells may cause

  18. Magnetic strip patterns induced by focused ion beam irradiation

    SciTech Connect

    Makarov, D.; Tibus, S.; Rettner, C. T.; Thomson, T.; Terris, B. D.; Schrefl, T.; Albrecht, M.

    2008-03-15

    Focused ion beam exposure was used to locally alter the magnetic properties of a continuous Co/Pd multilayer film with perpendicular magnetic anisotropy. The saturation magnetization, coercivity, and magnetic anisotropy of the films can be tuned by Ga irradiation depending on exposure dose. As a result, a periodic strip pattern consisting of 80 nm wide exposed strips which are magnetically soft, separated by 170 nm wide magnetically hard, unexposed areas was created. Due to strong magnetostatic coupling between the strips, a number of magnetic domain configurations could be stabilized and these have been observed by magnetic force microscopy and magneto-optic Kerr effect measurements. The magnetic domain configurations and their reversal behavior were investigated by micromagnetic simulations as a function of exposure dose and strip period.

  19. A priming dose of protons alters the early cardiac cellular and molecular response to 56Fe irradiation

    PubMed Central

    Ramadan, Samy S.; Sridharan, Vijayalakshmi; Koturbash, Igor; Miousse, Isabelle R.; Hauer-Jensen, Martin; Nelson, Gregory A.; Boerma, Marjan

    2015-01-01

    Purpose Recent evidence suggests that the heart may be injured by ionizing radiation at lower doses than was previously thought. This raises concerns about the cardiovascular risks from exposure to radiation during space travel. Since space travel is associated with exposure to both protons from solar particle events and heavy ions from galactic cosmic rays, we here examined the effects of a “priming” dose of protons on the cardiac cellular and molecular response to a “challenge” dose of 56Fe in a mouse model. Methods Male C57BL/6 mice at 10 weeks of age were exposed to sham-irradiation, 0.1 Gy of protons (150 MeV), 0.5 Gy of 56Fe (600 MeV/n), or 0.1 Gy of protons 24 hours prior to 0.5 Gy of 56Fe. Hearts were obtained at 7 days post-irradiation and western-blots were used to determine protein markers of cardiac remodeling, inflammatory infiltration, and cell death. Results Exposure to 56Fe caused an increase in expression of α-smooth muscle cell actin, collagen type III, the inflammatory cell markers mast cell tryptase, CD2 and CD68, the endothelial glycoprotein thrombomodulin, and cleaved caspase 3. Of all proteins investigated, protons at a dose of 0.1 Gy induced a small increase only in cleaved caspase 3 levels. On the other hand, exposure to protons 24 hours before 56Fe prevented all of the responses to 56Fe. Conclusions This study shows that a low dose of protons may prime the heart to respond differently to a subsequent challenge dose of heavy ions. Further investigation is required to identify responses at additional time points, consequences for cardiac function, threshold dose levels, and mechanisms by which a proton priming dose may alter the response to heavy ions. PMID:26948008

  20. A priming dose of protons alters the early cardiac cellular and molecular response to 56Fe irradiation

    NASA Astrophysics Data System (ADS)

    Ramadan, Samy S.; Sridharan, Vijayalakshmi; Koturbash, Igor; Miousse, Isabelle R.; Hauer-Jensen, Martin; Nelson, Gregory A.; Boerma, Marjan

    2016-02-01

    Purpose: Recent evidence suggests that the heart may be injured by ionizing radiation at lower doses than was previously thought. This raises concerns about the cardiovascular risks from exposure to radiation during space travel. Since space travel is associated with exposure to both protons from solar particle events and heavy ions from galactic cosmic rays, we here examined the effects of a ;priming; dose of protons on the cardiac cellular and molecular response to a ;challenge; dose of 56Fe in a mouse model. Methods: Male C57BL/6 mice at 10 weeks of age were exposed to sham-irradiation, 0.1 Gy of protons (150 MeV), 0.5 Gy of 56Fe (600 MeV/n), or 0.1 Gy of protons 24 hours prior to 0.5 Gy of 56Fe. Hearts were obtained at 7 days post-irradiation and western-blots were used to determine protein markers of cardiac remodeling, inflammatory infiltration, and cell death. Results: Exposure to 56Fe caused an increase in expression of α-smooth muscle cell actin, collagen type III, the inflammatory cell markers mast cell tryptase, CD2 and CD68, the endothelial glycoprotein thrombomodulin, and cleaved caspase 3. Of all proteins investigated, protons at a dose of 0.1 Gy induced a small increase only in cleaved caspase 3 levels. On the other hand, exposure to protons 24 hours before 56Fe prevented all of the responses to 56Fe. Conclusions: This study shows that a low dose of protons may prime the heart to respond differently to a subsequent challenge dose of heavy ions. Further investigation is required to identify responses at additional time points, consequences for cardiac function, threshold dose levels, and mechanisms by which a proton priming dose may alter the response to heavy ions.

  1. Virus Innexins induce alterations in insect cell and tissue function

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polydnaviruses are dsDNA viruses that induce immune and developmental alterations in their caterpillar hosts. Characterization of polydnavirus gene families and family members is necessary to understand mechanisms of pathology and evolution of these viruses, and may aid to elucidate the role of host...

  2. Survival fraction and phenotype alterations of Xenopus laevis embryos at 3 Gy, 150 kV X-ray irradiation.

    PubMed

    Carotenuto, Rosa; Tussellino, Margherita; Mettivier, Giovanni; Russo, Paolo

    2016-11-25

    To determine the radiosensitivity of Xenopus laevis embryos, aquatic organism model, for toxicity studies utilizing X-rays at acute high dose levels, by analysing its survival fraction and phenotype alterations under one-exposure integral dose. We used the standard Frog Embryo Teratogenesis Assay Xenopus test during the early stages of X. laevis development. The embryos were harvested until st. 46 when they were irradiated. The radiation effects were checked daily for a week and the survival, malformations and growth inhibition were assessed. Sibling tadpoles as control organisms were used. Statistical analysis was performed to assess the extent of any damage. Irradiation was performed with an X-ray tube operated at 150 kV. The tube containing the tadpoles was exposed to an air kerma of 3 Gy as measured in air with an in-beam ionization chamber. After one week, survival fraction of irradiated embryos was 58%, while for control embryos it was 81%. Hence, irradiation with 150 kV, 3 Gy X-rays produced a 23% decrease of survival in regard to unirradiated embryos. The 70% of the irradiated embryos showed an altered distribution of the skin pigmentation, in particular on the dorsal area and in the olfactory pits, where the pigment concentration increased by a factor 2. In conclusion exposure of X. laevis to 3 Gy, 150 kV X-rays induced a reduction of embryos survival and a significant modification of pigmentation. The authors think that X. laevis embryos, at st 46, is a suitable biological model for large scale investigations on the effects of ionizing radiation.

  3. Altered energy metabolism in an irradiated population of lizards at the Nevada Test Site

    SciTech Connect

    Nagy, K.A.; Medica, P.A.

    1985-07-01

    Field metabolic rates (via doubly labeled water), body compartmentalization of energy stores, and energy assimilation efficiencies were measured to assess all avenues of energy utilization in Uta stansburiana living in a low-level ..gamma..-irradiated plot in Rock Valley, Nevada. Comparison of energy budgets for radiation-sterilized females with those of nonirradiated control lizards revealed several substantial differences. Sterile females were heavier, mainly because they had extraordinarily large energy (fat) storage depots. Sterile females had much lower rates of energy expenditure via respiration and lower rates of energy intake by feeding. These differences are interpreted as indirect responses to radiation-induced sterility. There is little evidence of direct radiation effects on physiological functions other than reproduction.

  4. Complex nanoprecipitate structures induced by irradiation in immiscible alloy systems

    NASA Astrophysics Data System (ADS)

    Shu, Shipeng; Bellon, P.; Averback, R. S.

    2013-04-01

    We investigate the fundamentals of compositional patterning induced by energetic particle irradiation in model A-B substitutional binary alloys using kinetic Monte Carlo simulations. The study focuses on a type of nanostructure that was recently observed in dilute Cu-Fe and Cu-V alloys, where precipitates form within precipitates, a morphology that we term “cherry-pit” structures. The simulations show that the domain of stability of these cherry-pit structures depends on the thermodynamic and kinetic asymmetry between the A and B elements. In particular, both lower solubilities and diffusivities of A in B compared to those of B in A favor the stabilization of these cherry-pit structures for A-rich average compositions. The simulation results are rationalized by extending the analytic model introduced by Frost and Russell for irradiation-induced compositional patterning so as to include the possible formation of pits within precipitates. The simulations indicate also that the pits are dynamical structures that undergo nearly periodic cycles of nucleation, growth, and absorption by the matrix.

  5. Depot risperidone-induced adverse metabolic alterations in female rats.

    PubMed

    Horska, Katerina; Ruda-Kucerova, Jana; Karpisek, Michal; Suchy, Pavel; Opatrilova, Radka; Kotolova, Hana

    2017-04-01

    Atypical antipsychotics are associated with adverse metabolic effects including weight gain, increased adiposity, dyslipidaemia, alterations in glucose metabolism and insulin resistance. Increasing evidence suggests that metabolic dysregulation precedes weight gain development. The aim of this study was to evaluate alterations in adipokines, hormones and basic serum biochemical parameters induced by chronic treatment with depot risperidone at two doses (20 and 40 mg/kg) in female Sprague-Dawley rats. Dose-dependent metabolic alterations induced by risperidone after 6 weeks of treatment were revealed. Concomitant to weight gain and increased liver weight, an adverse lipid profile with an elevated triglyceride level was observed in the high exposure group, administered a 40 mg/kg dose repeatedly, while the low dose exposure group, administered a 20 mg/kg dose, developed weight gain without alterations in the lipid profile and adipokine levels. An initial peak in leptin serum level after the higher dose was observed in the absence of weight gain. This finding may indicate that the metabolic alterations observed in this study are not consequent to body weight gain. Taken together, these data may support the primary effects of atypical antipsychotics on peripheral tissues.

  6. Ion irradiation induced disappearance of dislocations in a nickel-based alloy

    NASA Astrophysics Data System (ADS)

    Chen, H. C.; Li, D. H.; Lui, R. D.; Huang, H. F.; Li, J. J.; Lei, G. H.; Huang, Q.; Bao, L. M.; Yan, L.; Zhou, X. T.; Zhu, Z. Y.

    2016-06-01

    Under Xe ion irradiation, the microstructural evolution of a nickel based alloy, Hastelloy N (US N10003), was studied. The intrinsic dislocations are decorated with irradiation induced interstitial loops and/or clusters. Moreover, the intrinsic dislocations density reduces as the irradiation damage increases. The disappearance of the intrinsic dislocations is ascribed to the dislocations climb to the free surface by the absorption of interstitials under the ion irradiation. Moreover, the in situ annealing experiment reveals that the small interstitial loops and/or clusters induced by the ion irradiation are stable below 600 °C.

  7. Radio-induced alteration in cordierite - Implications for petrology, gemmology and materials science

    NASA Astrophysics Data System (ADS)

    Krickl, R.; Nasdala, L.; Grambole, D.; Kaindl, R.

    2009-04-01

    Cordierite is a common metamorphic and magmatic mineral, which is used as petrologic tool for reconstructing the history of its host rock. Further applications include cordierite gemstones and the use of synthetic analogs in ceramics. Cordierite is stable over a wide temperature and pressure range and relatively resistant to chemical alteration; however, its properties can be significantly changed upon the impact of external irradiation. In the course of a comprehensive study, natural radiohaloes in cordierite (a widespread feature caused by the impact of alpha-particles originating from radioactive inclusions) as well as artificial analogs produced by implantation of 8.8 MeV He2+ ions were investigated using modern micro-techniques. Additional irradiation experiments were performed using O6+ ions, electrons and gamma-rays. Ion irradiation causes yellow colouration that is strongly pleochroic, and fades at higher doses. The possibility of radiation-treatment for enhancing the quality of gem-cordierite is discussed. While samples remain crystalline up to doses of 1016 He2+/cm2, the same material is fully amorphised when irradiated with the same dose of 30 MeV O6+ ions. These different observations may help to estimate the performance assessment of cordierite-ceramics in radiated environments. A very important result concerning the petrological use of cordierite is the radio-induced transformation of channel constituents: Inside the irradiated areas the vibrational bands of CO2 decrease in intensity, whereas two new bands appear at 2135 cm-1 (both IR- and Raman-active; cf. Nasdala et al., 2006) and 1550 cm-1 (only Raman-activ). They are assigned to stretching vibrations of carbon monoxide and molecular oxygen, respectively, thus indicating a radio-chemical transformation 2CO2 → 2CO + O2 in alpha-irradiated cordierite. This study yields the first spectroscopic evidence for the irradiation-induced formation of molecular oxygen in cordierite. Polarised vibrational

  8. Irradiation-Induced Thermal Effects in Alloyed Metal Fuel of Fast Reactors

    NASA Astrophysics Data System (ADS)

    Kryukov, F. N.; Nikitin, O. N.; Kuzmin, S. V.; Belyaeva, A. V.; Gilmutdinov, I. F.; Grin, P. I.; Zhemkov, I. Yu

    2017-01-01

    The paper presents the results of studying alloyed metal fuel after irradiation in a fast reactor. Determined is the mechanism of fuel irradiation swelling, mechanical interaction between fuel and cladding, and distribution of fission products. Experience gained in fuel properties and behavior under irradiation as well as in irradiation-induced thermal effects occurred in alloyed metal fuel provides for a fuel pin design to have a burnup not less than 20% h. a.

  9. Growth Enhancement of Radish Sprouts Induced by Low Pressure O2 Radio Frequency Discharge Plasma Irradiation

    NASA Astrophysics Data System (ADS)

    Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu; Hayashi, Nobuya

    2012-01-01

    We studied growth enhancement of radish sprouts (Raphanus sativus L.) induced by low pressure O2 radio frequency (RF) discharge plasma irradiation. The average length of radish sprouts cultivated for 7 days after O2 plasma irradiation is 30-60% greater than that without irradiation. O2 plasma irradiation does not affect seed germination. The experimental results reveal that oxygen related radicals strongly enhance growth, whereas ions and photons do not.

  10. Gamma irradiation alters fatigue-crack behavior and fracture toughness in 1900H and GUR 1050 UHMWPE.

    PubMed

    Cole, Jantzen C; Lemons, Jack E; Eberhardt, Alan W

    2002-01-01

    Pitting and delamination remain causative factors of polyethylene failure in total knee replacement. Gamma irradiation induces cross linking in ultra-high-molecular-weight polyethylene, which has been shown to improve wear resistance. Irradiation may reduce fracture toughness and fatigue strength, however, and the effects of irradiation are dependent upon the resin, processing technique, and radiation dose. The effects of varying levels of gamma irradiation (0, 33, 66, and 100 kGy) on the fracture toughness and fatigue-crack resistance of UHMWPE, isostatically molded from 1900H and GUR 1050 resins, were examined. Paris law regressions were performed to quantify fatigue-crack propagation rates as functions of change in stress intensity, and J-integral methods were used to quantify the elastic-plastic fracture toughness. The results indicated that gamma irradiation reduced the resistance of both materials to fatigue-crack growth, and that the reductions were radiation dosage and resin dependent. Irradiation at any level was detrimental to the fracture toughness of the 1900H specimens. Irradiation at 33 kGy increased fracture toughness for the GUR 1050 specimens, and substantial reductions were observed only at the highest irradiation level. Scanning electron microscopy of the fracture surface revealed diamond-like fracture patterns of the nonirradiated specimens indicative of ductile, multilevel fracture. Pronounced striations were apparent on these fracture surfaces, oriented perpendicular to the direction of crack growth. The striations appeared as folds in surface layers of the GUR 1050 specimens. At the highest irradiation levels, the striations were nearly eliminated on the fracture surfaces of the 1900H specimens, and were markedly less severe for the GUR 1050. These results demonstrated that at higher irradiation levels the materials became more brittle in fatigue, with less ductile folding and tearing of the fracture surfaces.

  11. Pharmacological alterations that could underlie radiation-induced changes in associative memory and anxiety.

    PubMed

    Caceres, L G; Cid, M P; Uran, S L; Zorrilla Zubilete, M A; Salvatierra, N A; Guelman, L R

    2013-10-01

    It is widely known that ionizing radiation is a physical agent broadly used to kill tumor cells during human cancer therapy. Unfortunately, adjacent normal tissues can concurrently undergo undesirable cell injury. Previous data of our laboratory demonstrated that exposure of developing rats to ionizing radiations induced a variety of behavioral differences respect to controls, including changes in associative memory and in anxiety state. However, there is a lack of data concerning modifications in different related pharmacological intermediaries. Therefore, the aim of the present study was to investigate whether the behavioral differences observed in young animals irradiated at birth might be underlain by early changes in PKCß1 levels which, in turn, could lead to changes in hippocampal GABAergic neurotransmission. Male Wistar rats were irradiated with 5Gy of X rays between 24 and 48 h after birth. Different pharmacological markers related to the affected behavioral tasks were assessed in control and irradiated hippocampus at 15 and 30 days, namely GABAA receptor, GAD65-67, ROS and PKCß1. Results showed that all measured parameters were increased in the hippocampus of 30-days-old irradiated animals. In contrast, in the hippocampus of 15-days-old irradiated animals only the levels of PKCß1 were decreased. These data suggest that PKCß1 might constitute a primary target for neonatal radiation damage on the hippocampus. Therefore, it could be hypothesized that an initial decrease in the levels of this protein can trigger a subsequent compensatory increase that, in turn, could be responsible for the plethora of biochemical changes that might underlie the previously observed behavioral alterations.

  12. Ion-irradiation-induced hardening in Inconel 718

    NASA Astrophysics Data System (ADS)

    Hunn, J. D.; Lee, E. H.; Byun, T. S.; Mansur, L. K.

    2001-07-01

    Inconel 718 is a material under consideration for areas in the target region of the spallation neutron source (SNS), now under construction at Oak Ridge National Laboratory (ORNL) in the US. In these positions, displacement damage from protons and neutrons will affect the mechanical properties. In addition, significant amounts of helium and hydrogen will build up in the material due to transmutation reactions. Nanoindentation measurements of solution-annealed (SA) Inconel 718 specimens, implanted with Fe-, He-, and H-ions to simulate SNS target radiation conditions, have shown that hardening occurs due to ion-induced displacement damage as well as due to the build-up of helium bubbles in the irradiated layer. Precipitation-hardened (PH) Inconel 718 also exhibited hardening by helium build-up but showed softening as a function of displacement damage due to dissolution of the γ ' and γ″ precipitates.

  13. Arsenic-induced Histological Alterations in Various Organs of Mice

    PubMed Central

    Noman, Abu Shadat Mohammod; Dilruba, Sayada; Mohanto, Nayan Chandra; Rahman, Lutfur; Khatun, Zohora; Riad, Wahiduzzaman; Al Mamun, Abdullah; Alam, Shahnur; Aktar, Sharmin; Chowdhury, Srikanta; Saud, Zahangir Alam; Rahman, Zillur; Hossain, Khaled; Haque, Azizul

    2015-01-01

    Deposition of arsenic in mice through groundwater is well documented but little is known about the histological changes of organs by the metalloid. Present study was designed to evaluate arsenic-induced histological alterations in kidney, liver, thoracic artery and brain of mice which are not well documented yet. Swiss albino male mice were divided into 2 groups and treated as follows: Group 1: control, 2: arsenic (sodium arsenite at 10 mg/kg b.w. orally for 8 wks). Group 2 showed marked degenerative changes in kidney, liver, thoracic artery, and brain whereas Group 1 did not reveal any abnormalities on histopathology. We therefore concluded that arsenic induces histological alterations in the tested organs. PMID:26740907

  14. Commercial sunscreen formulations: UVB irradiation stability and effect on UVB irradiation-induced skin oxidative stress and inflammation.

    PubMed

    Vilela, Fernanda M P; Oliveira, Franciane M; Vicentini, Fabiana T M C; Casagrande, Rubia; Verri, Waldiceu A; Cunha, Thiago M; Fonseca, Maria J V

    2016-10-01

    Evidence shows that sunscreens undergo degradation processes induced by UV irradiation forming free radicals, which reduces skin protection. In this regard, the biological effects of three commercial sunscreen formulations upon UVB irradiation in the skin were investigated. The three formulations had in common the presence of benzophenone-3 added with octyl methoxycinnamate or octyl salycilate or both, which are regular UV filters in sunscreens. The results show that formulations F1 and F2 presented partial degradation upon UVB irradiation. Formulations F1 and F2 presented higher skin penetration profiles than F3. None of the formulations avoided UVB irradiation-induced GSH depletion, but inhibited reduction of SOD activity, suggesting the tested formulations did not present as a major mechanism inhibiting all UVB irradiation-triggered oxidative stress pathways. The formulations avoided the increase of myeloperoxidase activity and cytokine production (IL-1β and TNF-α), but with different levels of protection in relation to the IL-1β release. Concluding, UVB irradiation can reduce the stability of sunscreens, which in turn, present the undesirable properties of reaching viable skin. Additionally, the same SPF does not mean that different sunscreens will present the same biological effects as SPF is solely based on a skin erythema response. This found opens up perspectives to consider additional studies to reach highly safe sunscreens.

  15. 60Co irradiation of Shiga toxin (Stx)-producing Escherichia coli induces Stx phage.

    PubMed

    Yamamoto, Tatsuo; Kojio, Seiichi; Taneike, Ikue; Nakagawa, Saori; Iwakura, Nobuhiro; Wakisaka-Saito, Noriko

    2003-05-16

    Shiga toxin (Stx)-producing Escherichia coli (STEC), an important cause of hemolytic uremic syndrome, was completely killed by (60)Co irradiation at 1 x l0(3) gray (1 kGy) or higher. However, a low dose of irradiation (0.1-0.3 kGy) markedly induced Stx phage from STEC. Stx production was observed in parallel to the phage induction. Inactivation of Stx phage required a higher irradiation dose than that for bacterial killing. Regarding Stx, cytotoxicity was susceptible to irradiation, but cytokine induction activity was more resistant than Stx phage. The findings suggest that (1). although (60)Co irradiation is an effective means to kill the bacteria, it does induce Stx phage at a lower irradiation dose, with a risk of Stx phage transfer and emergence of new Stx-producing strains, and (2). irradiation differentially inactivates some activities of Stx.

  16. Valproic acid inhibits irradiation-induced epithelial-mesenchymal transition and stem cell-like characteristics in esophageal squamous cell carcinoma

    PubMed Central

    Kanamoto, Ayako; Ninomiya, Itasu; Harada, Shinichi; Tsukada, Tomoya; Okamoto, Koichi; Nakanuma, Shinichi; Sakai, Seisho; Makino, Isamu; Kinoshita, Jun; Hayashi, Hironori; Oyama, Katsunobu; Miyashita, Tomoharu; Tajima, Hidehiro; Takamura, Hiroyuki; Fushida, Sachio; Ohta, Tetsuo

    2016-01-01

    Esophageal carcinoma is one of the most aggressive malignancies, and is characterized by poor response to current therapy and a dismal survival rate. In this study we investigated whether irradiation induces epithelial-mesenchymal transition (EMT) in esophageal squamous cell carcinoma (ESCC) TE9 cells and whether the classic histone deacetylase (HDAC) inhibitor valproic acid (VPA) suppresses these changes. First, we showed that 2 Gy irradiation induced spindle cell-like morphologic changes, decreased expression of membranous E-cadherin, upregulated vimentin expression, and altered the localization of β-catenin from its usual membrane-bound location to cytoplasm in TE9 cells. Irradiation induced upregulation of transcription factors including Slug, Snail, and Twist, which regulate EMT. Stimulation by irradiation resulted in increased TGF-β1 and HIF-1α expression and induced Smad2 and Smad3 phosphorylation. Furthermore, irradiation enhanced CD44 expression, indicating acquisition of cancer stem-like cell properties. In addition, irradiation enhanced invasion and migration ability with upregulation of matrix metalloproteinases. These findings indicate that single-dose irradiation can induce EMT in ESCC cells. Second, we found that treatment with 1 mM VPA induced reversal of EMT caused by irradiation in TE9 cells, resulting in attenuated cell invasion and migration abilities. These results suggest that VPA might have clinical value to suppress irradiation-induced EMT. The reversal of EMT by HDAC inhibitors may be a new therapeutic strategy to improve the effectiveness of radiotherapy in ESCC by inhibiting the enhancement of invasion and metastasis. PMID:27826618

  17. Functional changes induced by chronic UVA irradiation to cultured human dermal fibroblasts.

    PubMed

    Naru, E; Suzuki, T; Moriyama, M; Inomata, K; Hayashi, A; Arakane, K; Kaji, K

    2005-12-01

    Ultraviolet (UV) irradiation induces damage of the skin, and in particular, photoageing is known to be the result of chronic UV irradiation. Many investigations have attempted to clarify the mechanisms of photoageing induced by chronic UVA irradiation, but consensus has not been achieved yet by in vivo experiments, mostly due to differences among UV sources and animals used for experiments. In vitro experiments have shown that a single exposure to UVA irradiation causes overexpression of matrix metalloproteinases and denaturation of collagen, but the mechanisms of the photoageing effects of chronic UVA irradiation are still unclear. To examine the effects of chronic UVA irradiation, we used an in vitro fibroblast cellular ageing system as a model of photoageing. Chronic UVA irradiation of normal human fibroblasts induced shortening of the cellular life span and an increase of cellular diameter, in parallel with expression of senescence-associated beta-galactosidase. Extracellular degradation enzyme, matrix metalloproteinase 1 (MMP-1) was overexpressed after repeated UVA irradiation, but tissue inhibitor of metalloproteinase 1 (TIMP-1) expression was hardly changed by chronic UVA irradiation. We conclude that chronic UVA irradiation of normal human fibroblasts induces cellular functional changes, leading to accelerated cellular ageing and MMP-1 overexpression.

  18. Altered Gravity Induces Oxidative Stress in Drosophila Melanogaster

    NASA Technical Reports Server (NTRS)

    Bhattacharya, Sharmila; Hosamani, Ravikumar

    2015-01-01

    Altered gravity environments can induce increased oxidative stress in biological systems. Microarray data from our previous spaceflight experiment (FIT experiment on STS-121) indicated significant changes in the expression of oxidative stress genes in adult fruit flies after spaceflight. Currently, our lab is focused on elucidating the role of hypergravity-induced oxidative stress and its impact on the nervous system in Drosophila melanogaster. Biochemical, molecular, and genetic approaches were combined to study this effect on the ground. Adult flies (2-3 days old) exposed to acute hypergravity (3g, for 1 hour and 2 hours) showed significantly elevated levels of Reactive Oxygen Species (ROS) in fly brains compared to control samples. This data was supported by significant changes in mRNA expression of specific oxidative stress and antioxidant defense related genes. As anticipated, a stress-resistant mutant line, Indy302, was less vulnerable to hypergravity-induced oxidative stress compared to wild-type flies. Survival curves were generated to study the combined effect of hypergravity and pro-oxidant treatment. Interestingly, many of the oxidative stress changes that were measured in flies showed sex specific differences. Collectively, our data demonstrate that altered gravity significantly induces oxidative stress in Drosophila, and that one of the organs where this effect is evident is the brain.

  19. Tea tree oil-induced transcriptional alterations in Staphylococcus aureus.

    PubMed

    Cuaron, Jesus A; Dulal, Santosh; Song, Yang; Singh, Atul K; Montelongo, Cesar E; Yu, Wanqin; Nagarajan, Vijayaraj; Jayaswal, Radheshyam K; Wilkinson, Brian J; Gustafson, John E

    2013-03-01

    Tea tree oil (TTO) is a steam distillate of Melaleuca alternifolia that demonstrates broad-spectrum antibacterial activity. This study was designed to document how TTO challenge influences the Staphylococcus aureus transcriptome. Overall, bioinformatic analyses (S. aureus microarray meta-database) revealed that both ethanol and TTO induce related transcriptional alterations. TTO challenge led to the down-regulation of genes involved with energy-intensive transcription and translation, and altered the regulation of genes involved with heat shock (e.g. clpC, clpL, ctsR, dnaK, groES, groEL, grpE and hrcA) and cell wall metabolism (e.g. cwrA, isaA, sle1, vraSR and vraX). Inactivation of the heat shock gene dnaK or vraSR which encodes a two-component regulatory system that responds to peptidoglycan biosynthesis inhibition led to an increase in TTO susceptibility which demonstrates a protective role for these genes in the S. aureus TTO response. A gene (mmpL) encoding a putative resistance, nodulation and cell division efflux pump was also highly induced by TTO. The principal antimicrobial TTO terpene, terpinen-4-ol, altered ten genes in a transcriptional direction analogous to TTO. Collectively, this study provides additional insight into the response of a bacterial pathogen to the antimicrobial terpene mixture TTO.

  20. Quality of gamma ray-irradiated iceberg lettuce and treatments to minimize irradiation-induced disorders

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irradiation of Iceberg lettuce was recently approved by the FDA to enhance microbial safety and to extend shelf-life at doses up to 4 kGy. However, the radiation tolerance of whole head lettuce is unclear. The present study was conducted to investigate the effects of irradiation on the quality of he...

  1. Artificial sweeteners induce glucose intolerance by altering the gut microbiota.

    PubMed

    Suez, Jotham; Korem, Tal; Zeevi, David; Zilberman-Schapira, Gili; Thaiss, Christoph A; Maza, Ori; Israeli, David; Zmora, Niv; Gilad, Shlomit; Weinberger, Adina; Kuperman, Yael; Harmelin, Alon; Kolodkin-Gal, Ilana; Shapiro, Hagit; Halpern, Zamir; Segal, Eran; Elinav, Eran

    2014-10-09

    Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage.

  2. Antioxidant enzymes and the mechanism of the bystander effect induced by ultraviolet C irradiation of A375 human melanoma cells.

    PubMed

    Ghosh, Rita; Guha, Dipanjan; Bhowmik, Sudipta; Karmakar, Sayantani

    2013-09-18

    Irradiated cells generate dynamic responses in non-irradiated cells; this signaling phenomenon is known as the bystander effect (BE). Factors secreted by the irradiated cells communicate some of these signals. Conditioned medium from UVC-irradiated A375 human melanoma cells was used to study the BE. Exposure of cells to conditioned medium induce cell-cycle arrest at the G2/M transition. Although conditioned medium treatment, by itself, did not alter cell viability, treated cells were more resistant to the lethal action of UVC or H2O2. This protective effect of conditioned medium was lost within 8h. Apoptotic or autophagic cell death was not involved in this resistance. Exposure to conditioned medium did not influence the rate of DNA repair, as measured by NAD(+) depletion. The activities of catalase and superoxide dismutase were elevated in cells exposed to conditioned medium, but returned to normal levels by 8h post-treatment. These results indicate a close correlation between BE-stimulated antioxidant activity and cellular sensitivity. Cell-cycle arrest and stimulation of antioxidant activity may account for the resistance to killing that was observed in bystander cells exposed to UVC or H2O2 treatment and are consistent with the role of the BE as a natural defense function triggered by UVC irradiation.

  3. Protection against Whole Body γ-Irradiation Induced Oxidative Stress and Clastogenic Damage in Mice by Ginger Essential Oil.

    PubMed

    Jeena, Kottarapat; Liju, Vijayasteltar B; Ramanath, Viswanathan; Kuttan, Ramadasan

    2016-01-01

    Radioprotective effects of ginger essential oil (GEO) on mortality, body weight alteration, hematological parameters, antioxidant status and chromosomal damage were studied in irradiated mice. Regression analysis of survival data in mice exposed to radiation yielded LD50/30 as 7.12 and 10.14 Gy for control (irradiation alone) and experimental (GEO-treated irradiated) mice, respectively, with a dose reduction factor (DRF) of 1.42. In mice exposed to whole-body gamma-irradiation (6 Gy), GEO pre-treatment at 100 and 500 mg/kg b.wt (orally) significantly ameliorated decreased hematological and immunological parameters. Radiation induced reduction in intestinal tissue antioxidant enzyme levels such as superoxide dismutase, catalase, glutathione peroxidase and glutathione was also reversed following administration of GEO. Tissue architecture of small intestine which was damaged following irradiation was improved upon administration of GEO. Anticlastogenic effects of GEO were studied by micronuclei assay, chromosomal aberration and alkaline gel electrophoresis assay. GEO significantly decreased the formation of micronuclei, increased the P/N ratio, inhibited the formation of chromosomal aberrations and protected agaisnt cellular DNA damage in bone marrow cells as revealed by comet assay. These results are supportive of use of GEO as a potential radioprotective compound.

  4. Alteration of Heterogeneous Ice Nucleation Properties Induced by Particle Aging

    NASA Astrophysics Data System (ADS)

    Sullivan, R. C.; Polen, M.; Beydoun, H.; Lawlis, E.; Ahern, A.; Jahn, L.; Hill, T. C. J.

    2015-12-01

    Aerosol particles that can serve as ice nuclei frequently experience rapid and extensive chemical aging during atmospheric transport. This is known to significantly alter some ice nucleation modes of the few types of ice nucleation particle systems where aging effects have been simulated, such as for mineral dust. Yet much of our understanding of atmospheric particle freezing properties is derived from measurements of fresh or unaged particles. We know almost nothing regarding how atmospheric aging might alter the freezing properties of biomass burning aerosol or biological particle nucleants. We have investigated the effects of simulated aging using a chamber reactor on the heterogeneous ice nucleation properties of biomass burning aerosol (BBA) and ice-active bacteria particles. Some types of aging were found to enhance the freezing ability of BBA, exhibited as a shift in a portion of the droplet freezing curve to warmer temperatures by a few °C. Ice-active bacteria were found to consistently loose their most ice-active nucleants after repeated aging cycles. The bacterial systems always retained significantly efficient ice active sites that still allowed them to induce freezing at mild/warm temperatures, despite this decrease in freezing ability. A comprehensive series of online single-particle mass spectrometry and offline spectromicroscopic analysis of individual particles was used to determine how the aging altered the aerosol's composition, and gain mechanistic insights into how this in turn altered the freezing properties. Our new ice nucleation framework that uses a continuous distribution of ice active site ability (contact angle) was used to interpret the droplet freezing spectra and understand how aging alters the internal and external variability, and rigidity, of the ice active sites.

  5. Light-induced voltage alteration for integrated circuit analysis

    DOEpatents

    Cole, Jr., Edward I.; Soden, Jerry M.

    1995-01-01

    An apparatus and method are described for analyzing an integrated circuit (IC), The invention uses a focused light beam that is scanned over a surface of the IC to generate a light-induced voltage alteration (LIVA) signal for analysis of the IC, The LIVA signal may be used to generate an image of the IC showing the location of any defects in the IC; and it may be further used to image and control the logic states of the IC. The invention has uses for IC failure analysis, for the development of ICs, for production-line inspection of ICs, and for qualification of ICs.

  6. Light-induced voltage alteration for integrated circuit analysis

    DOEpatents

    Cole, E.I. Jr.; Soden, J.M.

    1995-07-04

    An apparatus and method are described for analyzing an integrated circuit (IC). The invention uses a focused light beam that is scanned over a surface of the IC to generate a light-induced voltage alteration (LIVA) signal for analysis of the IC. The LIVA signal may be used to generate an image of the IC showing the location of any defects in the IC; and it may be further used to image and control the logic states of the IC. The invention has uses for IC failure analysis, for the development of ICs, for production-line inspection of ICs, and for qualification of ICs. 18 figs.

  7. Molecular alteration and carbonization of aspartic acid upon N + ion irradiation

    NASA Astrophysics Data System (ADS)

    Cui, F. Z.; Sun, S. Q.; Zhang, D. M.; Ma, Z. L.; Chen, G. Q.

    2000-06-01

    Structural changes of aspartic acid (Asp) irradiated by nitrogen ions of 30 keV were studied using Fourier transform infrared (FTIR) spectroscopy. Significant decreases of the intensities of COO -, NH 3+, COOH and CH 2 vibrations in the FTIR spectra, compared with those of unirradiated Asp, were observed for the sample irradiated at the fluence of 1×10 16 ions/cm 2. The decrease rates of the intensities of COO -, NH 3+, COOH and CH 2 vibrations with respect to the increasing irradiation fluences up to 4×10 16 ions/cm 2 were different. The results were attributable to the nonstoichiometrical desorption of corresponding volatile species such as H 2, NH 3+ and CO 2. The radiolysis residue of Asp after irradiation at a high fluence of 1×10 17 ions/cm 2 was analyzed and fatty acid was detected.

  8. Protective Effects of Hong Shan Capsule against Lethal Total-Body Irradiation-Induced Damage in Wistar Rats

    PubMed Central

    Li, Jianzhong; Xu, Jing; Xu, Weiheng; Qi, Yang; Lu, Yiming; Qiu, Lei; Hu, Zhenlin; Chu, Zhiyong; Chai, Yifeng; Zhang, Junping

    2015-01-01

    Hong Shan Capsule (HSC), a crude drug of 11 medicinal herbs, was used in clinical practice for the treatment of radiation injuries in China. In this study, we investigated its protection in rats against acute lethal total-body irradiation (TBI). Pre-administration of HSC reduced the radiation sickness characteristics, while increasing the 30-day survival of the irradiated rats. Administration of HSC also reduced the radiation sickness characteristics and increased the 30-day survival of mice after exposure to lethal TBI. Ultrastructural observation illustrated that the pretreatment of rats with HSC significantly attenuated the TBI-induced morphological changes in the different organs of irradiated rats. Gene expression profiles revealed the dramatic effect of HSC on alterations of gene expression caused by lethal TBI. Pretreatment with HSC prevented differential expression of 66% (1398 genes) of 2126 genes differentially expressed in response to TBI. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 32 pathways, such as pathways in cancer and the mitogen-activated protein kinase (MAPK) signaling pathway. Our analysis indicated that the pretreatment of rats with HSC modulated these pathways induced by lethal TBI, such as multiple MAPK pathways, suggesting that pretreatment with HSC might provide protective effects on lethal TBI mainly or partially through the modulation of these pathways. Our data suggest that HSC has the potential to be used as an effective therapeutic or radio-protective agent to minimize irradiation damage. PMID:26274957

  9. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus

    PubMed Central

    Craciunescu, Corneliu N.; Wu, Renan; Zeisel, Steven H.

    2006-01-01

    Diethanolamine (DEA) is present in many consumer products such as shampoo. Dermal administration of DEA diminishes hepatic stores of the essential nutrient choline, and we previously reported that dietary choline deficiency during pregnancy reduces neurogenesis and increases apoptosis in the hippocampus of fetal rats and mice. Therefore, DEA could also alter brain development. Timed-pregnant C57BL/6 mice were dosed dermally from gestation day 7 through 17 with DEA at 0, 20, 80, 160, 320, and 640 mg/kg body/day. At doses of DEA > 80 mg/kg body/day, we observed decreased litter size. In fetuses (embryonic day 17) collected from dams treated dermally with 80 mg/kg body/day DEA, we observed decreased neural progenitor cell mitosis at the ventricular surface of the ventricular zone of the hippocampus [to 56±14% (SE) histone 3 (H3) phosphorylation as compared to controls; P < 0.01]. We also observed increased apoptosis in fetal hippocampus (to 170±10% of control measured using TUNEL and to 178±7% of control measured using activated caspase 3; P < 0.01). Thus, maternal exposure to DEA reduces the number of neural progenitor cells in hippocampus by two mechanisms, and this could permanently alter memory function in offspring of mothers exposed to this common ingredient of shampoos and soaps.—Craciunescu, C. N., Wu, R., Zeisel, S. H. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus. PMID:16873886

  10. Aging induced endoplasmic reticulum stress alters sleep and sleep homeostasis.

    PubMed

    Brown, Marishka K; Chan, May T; Zimmerman, John E; Pack, Allan I; Jackson, Nicholas E; Naidoo, Nirinjini

    2014-06-01

    Alterations in the quality, quantity, and architecture of baseline and recovery sleep have been shown to occur during aging. Sleep deprivation induces endoplasmic reticular (ER) stress and upregulates a protective signaling pathway termed the unfolded protein response. The effectiveness of the adaptive unfolded protein response is diminished by age. Previously, we showed that endogenous chaperone levels altered recovery sleep in Drosophila melanogaster. We now report that acute administration of the chemical chaperone sodium 4-phenylbutyrate (PBA) reduces ER stress and ameliorates age-associated sleep changes in Drosophila. PBA consolidates both baseline and recovery sleep in aging flies. The behavioral modifications of PBA are linked to its suppression of ER stress. PBA decreased splicing of X-box binding protein 1 and upregulation of phosphorylated elongation initiation factor 2 α, in flies that were subjected to sleep deprivation. We also demonstrate that directly activating ER stress in young flies fragments baseline sleep and alters recovery sleep. Alleviating prolonged or sustained ER stress during aging contributes to sleep consolidation and improves recovery sleep or sleep debt discharge.

  11. Hydrogen peroxide-induced structural alterations of RNAse A.

    PubMed

    Lasch, P; Petras, T; Ullrich, O; Backmann, J; Naumann, D; Grune, T

    2001-03-23

    Proteins exposed to oxidative stress are degraded via proteolytic pathways. In the present study, we undertook a series of in vitro experiments to establish a correlation between the structural changes induced by mild oxidation of the model protein RNase A and the proteolytic rate found upon exposure of the modified protein toward the isolated 20 S proteasome. Fourier transform infrared spectroscopy was used as a structure-sensitive probe. We report here strong experimental evidence for oxidation-induced conformational rearrangements of the model protein RNase A and, at the same time, for covalent modifications of amino acid side chains. Oxidation-related conformational changes, induced by H(2)O(2) exposure of the protein may be monitored in the amide I region, which is sensitive to changes in protein secondary structure. A comparison of the time- and H(2)O(2) concentration-dependent changes in the amide I region demonstrates a high degree of similarity to spectral alterations typical for temperature-induced unfolding of RNase A. In addition, spectral parameters of amino acid side chain marker bands (Tyr, Asp) revealed evidence for covalent modifications. Proteasome digestion measurements on oxidized RNase A revealed a specific time and H(2)O(2) concentration dependence; at low initial concentration of the oxidant, the RNase A turnover rate increases with incubation time and concentration. Based on these experimental findings, a correlation between structural alterations detected upon RNase A oxidation and proteolytic rates of RNase A is established, and possible mechanisms of the proteasome recognition process of oxidatively damaged proteins are discussed.

  12. Fibrinogen Induces Alterations of Endothelial Cell Tight Junction Proteins

    PubMed Central

    PATIBANDLA, PHANI K.; TYAGI, NEETU; DEAN, WILLIAM L.; TYAGI, SURESH C.; ROBERTS, ANDREW M.; LOMINADZE, DAVID

    2009-01-01

    We previously showed that an elevated content of fibrinogen (Fg) increased formation of filamentous actin and enhanced endothelial layer permeability. In the present work we tested the hypothesis that Fg binding to endothelial cells (ECs) alters expression of actin-associated endothelial tight junction proteins (TJP). Rat cardiac microvascular ECs were grown in gold plated chambers of an electrical cell-substrate impedance system, 8-well chambered, or in 12-well plates. Confluent ECs were treated with Fg (2 or 4 mg/ml), Fg (4 mg/ml) with mitogen-activated protein kinase (MEK) kinase inhibitors (PD98059 or U0126), Fg (4 mg/ml) with anti-ICAM-1 antibody or BQ788 (endothelin type B receptor blocker), endothelin-1, endothelin-1 with BQ788, or medium alone for 24 h. Fg induced a dose-dependent decrease in EC junction integrity as determined by transendothelial electrical resistance (TEER). Western blot analysis and RT-PCR data showed that the higher dose of Fg decreased the contents of TJPs, occludin, zona occluden-1 (ZO-1), and zona occluden-2 (ZO-2) in ECs. Fg-induced decreases in contents of the TJPs were blocked by PD98059, U0126, or anti-ICAM-1 antibody. While BQ788 inhibited endothelin-1-induced decrease in TEER, it did not affect Fg-induced decrease in TEER. These data suggest that Fg increases EC layer permeability via the MEK kinase signaling pathway by affecting occludin, ZO-1, and ZO-2, TJPs, which are bound to actin filaments. Therefore, increased binding of Fg to its major EC receptor, ICAM-1, during cardiovascular diseases may increase microvascular permeability by altering the content and possibly subcellular localization of endothelial TJPs. PMID:19507189

  13. Molecular alterations in tumorigenic human bronchial and breast epithelial cells induced by high let radiation

    NASA Astrophysics Data System (ADS)

    Hei, T. K.; Zhao, Y. L.; Roy, D.; Piao, C. Q.; Calaf, G.; Hall, E. J.

    Carcinogenesis is a multi-stage process with sequence of genetic events governing the phenotypic expression of a series of transformation steps leading to the development of metastatic cancer. In the present study, immortalized human bronchial (BEP2D) and breast (MCF-10F) cells were irradiated with graded doses of either 150 keV/μm alpha particles or 1 GeV/nucleon 56Fe ions. Transformed cells developed through a series of successive steps before becoming tumorigenic in nude mice. Cell fusion studies indicated that radiation-induced tumorigenic phenotype in BEP2D cells could be completely suppressed by fusion with non-tumorigenic BEP2D cells. The differential expressions of known genes between tumorigenic bronchial and breast cells induced by alpha particles and their respective control cultures were compared using cDNA expression array. Among the 11 genes identified to be differentially expressed in BEP2D cells, three ( DCC, DNA-PK and p21 CIPI) were shown to be consistently down-regulated by 2 to 4 fold in all the 5 tumor cell lines examined. In contrast, their expressions in the fusion cell lines were comparable to control BEP2D cells. Similarly, expression levels of a series of genes were found to be altered in a step-wise manner among tumorigenic MCF-10F cells. The results are highly suggestive that functional alterations of these genes may be causally related to the carcinogenic process.

  14. Reduction and transformation of fluorinated graphene induced by ultraviolet irradiation.

    PubMed

    Ren, Mengmeng; Wang, Xu; Dong, Changshuai; Li, Baoyin; Liu, Yang; Chen, Teng; Wu, Peng; Cheng, Zheng; Liu, Xiangyang

    2015-10-07

    The effect of ultraviolet irradiation on fluorinated graphene (FG) dispersed in toluene was investigated for the first time. The chemical and physical characteristics of FG before and after ultraviolet irradiation were analyzed by UV-vis, FTIR, XPS,EDS, oxygen flask combustion (OFC), XRD, TGA, Raman, SEM, TEM and fluorescence spectroscopy. It is found that the F/C ratio initially decreases rapidly and then slowly with irradiation time, finally to 0.179 after irradiation for 48 h. The nature of partial C-F bonds transforms from covalent to "semi-covalent" bonding in the process of irradiation. The restoration of new sp(2) clusters is fast at the early stage within 6 h of irradiation, promoting the structural rearrangement. The morphology of irradiated fluorinated graphene (iFG) is not significantly destroyed by ultraviolet while more overlapped sheets are formed due to quick defluorination. Photoluminescence (PL) properties show that "blue emission" located at 432 nm is enhanced due to the recovery of sp(2) domains. In particular, compared to non-aromatic solvents, there is a "synergistic effect" between aromatic solvents and ultraviolet in the defluorination process. FG is unstable and shows some structural transformations under ultraviolet irradiation, which can be used to tune its structure and properties.

  15. Radioprotective effect of Curcuma longa extract on γ-irradiation-induced oxidative stress in rats.

    PubMed

    Nada, Ahmed S; Hawas, Asrar M; Amin, Nour El-Din; Elnashar, Magdy M; Abd Elmageed, Zakaria Y

    2012-04-01

    This study was conducted to evaluate the modulatory effect of aqueous extract of Curcuma longa (L.) against γ-irradiation (GR), which induces biochemical disorders in male rats. The sublethal dose of GR was determined in primary hepatocytes. Also, the effect of C. longa extract was examined for its activity against GR. In rats, C. longa extract was administered daily (200 mg/kg body mass) for 21 days before, and 7 days after GR exposure (6.5 Gy). The lipid profile and antioxidant status, as well as levels of transaminases, interleukin-6 (IL-6), and tumour necrosis factor α (TNFα) were assessed. The results showed that in hepatocytes, the aqueous extract exhibited radioprotective activity against exposure to GR. Exposure of untreated rats to GR resulted in transaminase disorders, lipid abnormalities, elevation of lipid peroxidation, trace element alterations, release of IL-6 and TNF, and decrease in glutathione and protein level of superoxide dismutase-1 (SOD-1) and peroxiredoxin-1 (PRDX-1). However, treatment of rats with this extract before and after GR exposure improved antioxidant status and minimized the radiation-induced increase in inflammatory cytokines. Changes occurred in the tissue levels of trace elements, and the protein levels of SOD-1 and PRDX-1 were also modulated by C. longa extract. Overall, C. longa exerted a beneficial radioprotective effect against radiation-induced oxidative stress in male rats by alleviating pathological disorders and modulating antioxidant enzymes.

  16. Microcirculation alterations in experimentally induced gingivitis in dogs.

    PubMed

    Matsuo, Masato; Okudera, Toshimitsu; Takahashi, Shun-Suke; Wada-Takahashi, Satoko; Maeda, Shingo; Iimura, Akira

    2017-01-01

    The present study aimed to morphologically examine the gingival microvascular network using a microvascular resin cast (MRC) technique, and to investigate how inflammatory disease functionally affects gingival microcirculation using laser Doppler flowmetry (LDF). We used four beagle dogs with healthy periodontal tissue as experimental animals. To cause periodontal inflammation, dental floss was placed around the cervical neck portions of the right premolars. The unmanipulated left premolars served as controls, and received plaque control every 7 days. After 90 days, gingivitis was induced in the experimental side, while the control side maintained healthy gingiva. To perform morphological examinations, we used an MRC method involving the injection of low-viscosity synthetic resin into the blood vessels, leading to peripheral soft-tissue dissolution and permitting observation of the bone, teeth, and vascular cast. Gingival blood flow was estimated using an LDF meter. The control gingival vasculature showed hairpin-loop-like networks along the tooth surface. The blood vessels had diameters of 20-40 μm and were regularly arranged around the cervical portion. On the other hand, the vasculature in the experimental group was twisted and gathered into spiral forms, with blood vessels that had uneven surfaces and smaller diameters of 8-10 μm. LDF revealed reduced gingival blood flow in the group with experimentally induced gingivitis compared to controls. The actual measurements of gingival blood flow by LDF were in agreement with the alterations that would be expected based on the gingivitis-induced morphological alterations observed with the MRC technique.

  17. Major alteration of the pathological phenotype in gamma irradiated mdx soleus muscles

    SciTech Connect

    Weller, B.; Karpati, G.; Lehnert, S.; Carpenter, S. )

    1991-07-01

    Two thousand rads of gamma irradiation delivered to the lower legs of ten day old normal and x-chromosome linked muscular dystrophy (mdx) mice caused significant inhibition of tibial bone and soleus muscle fiber growth. In the irradiated mdx solei, there was a major loss of muscle fibers, lack of central nucleation, and some endomysial fibrosis. These features were caused by a failure of regeneration of muscle fibers due to impaired proliferative capacity of satellite cells. Gamma irradiation transforms the late pathological phenotype of mdx muscles, so that in one major aspect (muscle fiber loss) they resemble muscles in Duchenne muscular dystrophy. However, extensive endomysial fibrosis which is another characteristic feature of Duchenne muscular dystrophy did not develop. This experimental model could be useful for the functional investigation of possible beneficial effects of therapeutic interventions in mdx dystrophy.

  18. Treadmill Exercise Induces Hippocampal Astroglial Alterations in Rats

    PubMed Central

    Bernardi, Caren; Tramontina, Ana Carolina; Nardin, Patrícia; Biasibetti, Regina; Costa, Ana Paula; Vizueti, Adriana Fernanda; Batassini, Cristiane; Tortorelli, Lucas Silva; Wartchow, Krista Minéia; Dutra, Márcio Ferreira; Bobermin, Larissa; Sesterheim, Patrícia; Quincozes-Santos, André; de Souza, Jaqueline; Gonçalves, Carlos Alberto

    2013-01-01

    Physical exercise effects on brain health and cognitive performance have been described. Synaptic remodeling in hippocampus induced by physical exercise has been described in animal models, but the underlying mechanisms remain poorly understood. Changes in astrocytes, the glial cells involved in synaptic remodeling, need more characterization. We investigated the effect of moderate treadmill exercise (20 min/day) for 4 weeks on some parameters of astrocytic activity in rat hippocampal slices, namely, glial fibrillary acidic protein (GFAP), glutamate uptake and glutamine synthetase (GS) activities, glutathione content, and S100B protein content and secretion, as well as brain-derived neurotrophic factor (BDNF) levels and glucose uptake activity in this tissue. Results show that moderate treadmill exercise was able to induce a decrease in GFAP content (evaluated by ELISA and immunohistochemistry) and an increase in GS activity. These changes could be mediated by corticosterone, whose levels were elevated in serum. BDNF, another putative mediator, was not altered in hippocampal tissue. Moreover, treadmill exercise caused a decrease in NO content. Our data indicate specific changes in astrocyte markers induced by physical exercise, the importance of studying astrocytes for understanding brain plasticity, as well as reinforce the relevance of physical exercise as a neuroprotective strategy. PMID:23401802

  19. Hesperidin a flavanoglycone protects against gamma-irradiation induced hepatocellular damage and oxidative stress in Sprague-Dawley rats.

    PubMed

    Pradeep, Kannampalli; Park, Sang Hyun; Ko, Kyong Cheol

    2008-06-10

    Oxidative stress plays a pivotal role in the pathogenesis and progression of gamma-irradiation induced cellular damage and the administration of dietary antioxidants has been suggested to protect against the subsequent tissue damage. Here, we present the data to explore the hepatoprotective and antioxidant effect of hesperidin, a naturally occurring citrus flavanoglycone, against gamma-irradiation induced oxidative damage in the liver of rats. Healthy male Sprague-Dawley rats were exposed to gamma-irradiation (1 Gy, 3 Gy and 5 Gy) and were administered hesperidin (50 mg/kg and 100 mg/kg, b.w, orally) for 7 days post irradiation. The changes in body weight, liver weight, spleen index, serum and liver aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (gamma-GT) and serum ceruloplasmin levels were determined along with differences in the liver histopathology. Liver thiobarbuturic acid reactive substance as an index for lipid peroxidation and the levels of enzymatic antioxidants like superoxide dismutase, catalase, glutathione peroxidase and the status of non-enzymatic antioxidants as an index for oxidative stress were also determined. Exposure to gamma-irradiation resulted in hepatocellular damage in a dose-dependent manner, featuring a significantly decreased body weight and liver weight and higher levels of serum AST, ALT, ALP, LDH and gamma-GT levels and a simultaneous decrease in their levels in the liver tissue. Oxidative stress was evidenced by elevated levels of lipid peroxidation and a decrease in the levels of key enzymatic and non-enzymatic antioxidants in the liver. However, the gamma-irradiation induced toxic effects were dramatically and dose-dependently inhibited by hesperidin treatment as observed by the restoration in the altered levels of the marker enzymes, lipid peroxidation, enzymatic and non-enzymatic antioxidants. The results of the biochemical

  20. Irradiance and Temperature Dependence of Photo-Induced Orientation in Two Azobenzene-Based Polymers

    DTIC Science & Technology

    1998-06-23

    and Almeria Natansohn* Department of Chemistry, Queen’s University, Kingston, Ontario, K7L 3N6 Paul Rochon Department of Physics, Royal Military...1. IRRADIANCE AND TEMPERATURE DEPENDENCE OF PHOTO-INDUCED ORIENTATION IN TWO AZOBENZENE-BASED POLYMERS Dennis Hore and Almeria Natansohn...IRRADIANCE AND TEMPERATURE DEPENDENCE OF PHOTO-INDUCED ORIENTATION IN TWO AZOBENZENE-BASED POLYMERS Dennis Hore and Almeria Natansohn Department of

  1. UV irradiation induced transformation of TiO2 nanoparticles in water: aggregation and photoreactivity.

    PubMed

    Sun, Jing; Guo, Liang-Hong; Zhang, Hui; Zhao, Lixia

    2014-10-21

    Transformation of nanomaterials in aqueous environment has significant impact on their behavior in engineered application and natural system. In this paper, UV irradiation induced transformation of TiO2 nanoparticles in aqueous solutions was demonstrated, and its effect on the aggregation and photocatalytic reactivity of TiO2 was investigated. UV irradiation of a TiO2 nanoparticle suspension accelerated nanoparticle aggregation that was dependent on the irradiation duration. The aggregation rate increased from <0.001 nm/s before irradiation to 0.027 nm/s after 50 h irradiation, resulting in aggregates with a hydrodynamic diameter of 623 nm. The isoelectric point of the suspension was lowered from 7.0 to 6.4 after irradiation, indicating less positive charges on the surface. ATR-FTIR spectra displayed successive growth of surface hydroxyl groups with UV irradiation which might be responsible for the change of surface charge and aggregation rate. UV irradiation also changed the photocatalytic degradation rate of Rhodamine B by TiO2, which initially increased with irradiation time, then decreased. Based on the photoluminescence decay and photocurrent collection data, the change was attributed to the variation in interparticle charge transfer kinetics. These results highlight the importance of light irradiation on the transformation and reactivity of TiO2 nanomaterials.

  2. Free surface damage induced by irradiation of BCC iron

    NASA Astrophysics Data System (ADS)

    Korchuganov, Aleksandr V.

    2016-11-01

    The influence of the crystallographic orientation of bcc iron samples on the character of structural changes near the free surface irradiated with ions was studied in the framework of a molecular dynamics method. Irradiation of the (111) surface leads to the formation of craters surrounded by atoms escaped on the surface (adatoms). In the case of the (110) surface irradiation, a vacancy-type dislocation loop with the Burgers vector a <100> or a/2 <111> was formed. The number of adatoms and survived point defects was greater in the sample with the (110) surface than in the sample with the (111) surface for the atomic displacement cascade energies lower than 20 keV. The influence of the irradiated surface orientation on the number of generated point defects decreased with the increasing atomic displacement cascade energy.

  3. Prevention by alpha-difluoromethylornithine of skin carcinogenesis and immunosuppression induced by ultraviolet irradiation.

    PubMed

    Gensler, H L

    1991-01-01

    Administration of alpha-difluoromethylornithine (DFMO) to mice was found to inhibit both the cutaneous carcinogenesis and the immunosuppression induced by ultraviolet B (UVB) irradiation. BALB/cAnNTacfBR mice were given 1% F2MeOrn in their drinking water throughout the experiment. After 3 weeks, mice received UVB irradiation consisting of five 30-min exposures per week to banks of six FS40 Westinghouse sunlamps. In the photocarcinogenesis study, mice received a total dose of approximately 1273 kJ m-2. Skin cancer incidence in UV-irradiated mice was 38% 28 weeks after the first UV exposure; DFMO reduced this incidence to 9% (P = 0.025, log-rank test). Although DFMO has been demonstrated to be chemopreventive of chemical carcinogenesis, this is the first report that it is effective against cancers induced by a physical carcinogen. The immunosuppression induced by UVB irradiation prevents the host from rejecting antigenic, syngeneic UV-induced tumors, which normal mice can reject. The level of immunosuppression in UV-irradiated mice treated with DFMO was measured by a passive-transfer assay. Splenocytes from UV-irradiated mice to naive mice prevented the recipients from rejecting 20/24 UV-induced tumor challenges, whereas splenocytes from UV-irradiated mice treated with DFMO did not prevent recipients from rejecting such challenges (2/24 grew). The difference between these values was significant (P less than 0.001, two-sample test for binomial proportions). Phenotypic analysis of splenocytes used in the passive transfer, using a biotin-avidin-immunoperoxidase technique, revealed that DFMO treatment prevented the reduction of Ia expression normally seen in UV-irradiated mice. Thus, administration of DFMO reduced skin carcinogenesis and immunosuppression induced by UVB irradiation.

  4. Thermal Effects Induced by Laser Irradiation of Solids

    SciTech Connect

    Galovic, S.

    2004-12-01

    A part of incident energy is absorbed within the irradiated sample when a solid is exposed to the influence of laser radiation, to more general electromagnetic radiation within the wide range of wavelengths (from microwaves, to infrared radiation to X-rays), or to the energy of particle beams (electronic, protonic, or ionic). The absorption process signifies a highly selective excitation of the electronic state of atoms or molecules, followed by thermal and non-thermal de-excitation processes. Non-radiation de-excitation-relaxation processes induce direct sample heating. In addition, a great number of non-thermal processes (e.g., photoluminescence, photochemistry, photovoltage) may also induce heat generation as a secondary process. This method of producing heat is called the photothermal effect.The photothermal effect and subsequent propagation of thermal waves on the surface and in the volume of the solid absorbing the exciting beam may produce the following: variations in the temperature on the surfaces of the sample; deformation and displacement of surfaces; secondary infrared radiation (photothermal radiation); the formation of the gradient of the refractivity index; changes in coefficients of reflection and absorbtion; the generation of sound (photoacoustic generation), etc. These phenomena may be used in the investigation and measurement of various material properties since the profile and magnitude of the generated signal depend upon the nature of material absorbing radiation. A series of non-destructive spectroscopic, microscopic and defectoscopic detecting techniques, called photothermal methods, is developed on the basis of the above-mentioned phenomena.This paper outlines the interaction between the intensity modulated laser beam and solids, and presents a mathematical model of generated thermal sources. Generalized models for a photothermal response of optically excited materials have been obtained, including thermal memory influence on the propagation

  5. Morphological change of skin fibroblasts induced by UV Irradiation is involved in photoaging.

    PubMed

    Yamaba, Hiroyuki; Haba, Manami; Kunita, Mayumi; Sakaida, Tsutomu; Tanaka, Hiroshi; Yashiro, Youichi; Nakata, Satoru

    2016-08-01

    Human dermal fibroblasts (HDFs) are typically flattened or extensible shaped and play a critical role in the metabolism of extracellular matrix components. As the properties of fibroblasts in the dermis are considered to be influenced by their morphology, we investigated the morphological changes induced in fibroblasts by ultraviolet (UV) irradiation as well as the relationship between these changes and collagen metabolism. In this study, we showed that UVA exposure induced morphological changes and reduced collagen contents in HDFs. These morphological changes were accompanied a reduction in actin filaments and upregulation of the actin filament polymerization inhibitor, capping protein muscle Z-line ɑ1 (CAPZA1). External actin filament growth inhibitors also affected the shape of HDFs and reduced collagen levels. These results suggest that UVA exposure may inhibit the polymerization of actin filaments and induce morphological changes in skin fibroblasts. These morphological changes in fibroblasts may accelerate reductions in collagen synthesis. This mechanism may be one of the processes responsible for collagen reductions observed in photoaged skin. When natural materials that suppress these morphological changes in HDFs were evaluated, we found that an extract of Lilium 'Casa Blanca' (LCB) suppressed UVA-induced alterations in the shape of HDFs, which are typically followed by inhibition of collagen reduction. An analysis of the active compounds in LCB extract led to the identification of regaloside I, which had a structure of phenylpropanoid glycerol glucoside, as the active compound inhibiting the upregulation of CAPZA1. Therefore, inhibition of UVA-induced morphological changes in HDFs is considered to be promising way for the suppression of collagen reduction in photoaging.

  6. Heavy-ion irradiation induced diamond formation in carbonaceous materials.

    SciTech Connect

    Daulton, T. L.

    1999-01-08

    The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond.

  7. Epigenetic Alterations Induced by Ambient Particulate Matter in Mouse Macrophages

    PubMed Central

    Miousse, Isabelle R.; Chalbot, Marie-Cécile G.; Aykin-Burns, Nükhet; Wang, Xiaoying; Basnakian, Alexei; Kavouras, Ilias G.; Koturbash, Igor

    2014-01-01

    Respiratory mortality and morbidity has been associated with exposure to particulate matter (PM). Experimental evidence suggests involvement of cytotoxicity, oxidative stress, and inflammation in the development of PM-associated pathological states; however, the exact mechanisms remain unclear. In the current study, we analyzed short-term epigenetic response to PM10 (particles with aerodynamic diameter less than 10 μm) exposure in mouse ascitic RAW264.7 macrophages (BALB/C Abelson murine leukemia virus-induced tumor). Ambient PM10 was collected using a high volume sampler in Little Rock, AR. Analysis revealed that PM10 was composed mainly of Al and Fe, and the water soluble organic fraction was dominated by aliphatic and carbohydrate fragments and minor quantities of aromatic components. Exposure to PM10 compromised the cellular epigenome at concentrations 10–200 μg/ml. Specifically, epigenetic alterations were evident as changes in the methylation and expression of repetitive element-associated DNA and associated DNA methylation machinery. These results suggest that epigenetic alterations, in concert with cytotoxicity, oxidative stress, and inflammation, might contribute to the pathogenesis of PM-associated respiratory diseases. PMID:24535919

  8. Thermally-induced voltage alteration for integrated circuit analysis

    DOEpatents

    Cole, Jr., Edward I.

    2000-01-01

    A thermally-induced voltage alteration (TIVA) apparatus and method are disclosed for analyzing an integrated circuit (IC) either from a device side of the IC or through the IC substrate to locate any open-circuit or short-circuit defects therein. The TIVA apparatus uses constant-current biasing of the IC while scanning a focused laser beam over electrical conductors (i.e. a patterned metallization) in the IC to produce localized heating of the conductors. This localized heating produces a thermoelectric potential due to the Seebeck effect in any conductors with open-circuit defects and a resistance change in any conductors with short-circuit defects, both of which alter the power demand by the IC and thereby change the voltage of a source or power supply providing the constant-current biasing. By measuring the change in the supply voltage and the position of the focused and scanned laser beam over time, any open-circuit or short-circuit defects in the IC can be located and imaged. The TIVA apparatus can be formed in part from a scanning optical microscope, and has applications for qualification testing or failure analysis of ICs.

  9. AEM and AES of radiation-induced segregation in proton-irradiated stainless steels

    SciTech Connect

    Kenik, E.A.; Carter, R.D.; Damcott, D.L.; Atzmon, M.; Was, G.S.

    1994-06-01

    In order to avoid complications from long-term induced radioactivity of neutron-irradiated specimens, 4 type 304L alloys were irradiated to 1 dpa with 3.4 MeV protons at 400 C. Analytical electron microscopy and Auger electron spectrometry were used to measure composition at and near grain boundaries in controlled purity alloys. As a result of the narrow RIS profiles (<20 nm width) at grain boundaries induced in these materials by low temperature irradiation and the finite size of the excited volume for x-ray microanalysis, the measured profiles are convolutions of these two factors.

  10. Acute systemic rapamycin induces neurobehavioral alterations in rats.

    PubMed

    Hadamitzky, Martin; Herring, Arne; Keyvani, Kathy; Doenlen, Raphael; Krügel, Ute; Bösche, Katharina; Orlowski, Kathrin; Engler, Harald; Schedlowski, Manfred

    2014-10-15

    Rapamycin is a drug with antiproliferative and immunosuppressive properties, widely used for prevention of acute graft rejection and cancer therapy. It specifically inhibits the activity of the mammalian target of rapamycin (mTOR), a protein kinase known to play an important role in cell growth, proliferation and antibody production. Clinical observations show that patients undergoing therapy with immunosuppressive drugs frequently suffer from affective disorders such as anxiety or depression. However, whether these symptoms are attributed to the action of the distinct compounds remains rather elusive. The present study investigated in rats neurobehavioral consequences of acute rapamycin treatment. Systemic administration of a single low dose rapamycin (3mg/kg) led to enhanced neuronal activity in the amygdala analyzed by intracerebral electroencephalography and FOS protein expression 90min after drug injection. Moreover, behavioral investigations revealed a rapamycin-induced increase in anxiety-related behaviors in the elevated plus-maze and in the open-field. The behavioral alterations correlated to enhanced amygdaloid expression of KLK8 and FKBP51, proteins that have been implicated in the development of anxiety and depression. Together, these results demonstrate that acute blockade of mTOR signaling by acute rapamycin administration not only causes changes in neuronal activity, but also leads to elevated protein expression in protein kinase pathways others than mTOR, contributing to the development of anxiety-like behavior. Given the pivotal role of the amygdala in mood regulation, associative learning, and modulation of cognitive functions, our findings raise the question whether therapy with rapamycin may induce alterations in patients neuropsychological functioning.

  11. Ion beam damage assessment and waveguide formation induced by energetic Si-ion irradiation in lanthanum aluminate crystal

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Huang, Q.; Crespillo, M. L.; Qiao, M.; Liu, P.; Wang, X. L.

    2017-02-01

    Lanthanum aluminate (LaAlO3) crystal has emerged as one of the most valuable functional-materials, and its physical, electronic and optical properties strongly depend on the crystal structure, which can be easily altered in an irradiation environment and therefore affect the performance of LaAlO3-based devices. On the other hand, the preparation of LaAlO3 waveguide is also a scientific challenge for its potential application prospects in optoelectronics field. In this work, the damage evolution behavior of LaAlO3 crystal under Si-ion irradiation has been discussed in detail utilizing complementary characterization techniques, and then, single-mode waveguide of LaAlO3 crystal in the visible band can be obtained based on ion-irradiation-induced lattice damage behavior. Waveguide optical-coupling techniques are used to show its competitive features. Thus, novel optical waveguides with optimized features in LaAlO3 crystals can be tailored by a proper selection of ion mass, energy and fluence using the modification of the target material during ion irradiation process.

  12. Ultraviolet irradiation induces CYR61/CCN1, a mediator of collagen homeostasis, through activation of transcription factor AP-1 in human skin fibroblasts.

    PubMed

    Quan, Taihao; Qin, Zhaoping; Xu, Yiru; He, Tianyuan; Kang, Sewon; Voorhees, John J; Fisher, Gary J

    2010-06-01

    UV irradiation from the sun elevates the production of collagen-degrading matrix metalloproteinases (MMPs) and reduces the production of new collagen. This imbalance of collagen homeostasis impairs the structure and function of the dermal collagenous extracellular matrix (ECM), thereby promoting premature skin aging (photoaging). We report here that aberrant dermal collagen homeostasis in UV-irradiated human skin is mediated in part by a CCN-family member, cysteine-rich protein-61 (CYR61/CCN1). CYR61 is significantly elevated in acutely UV-irradiated human skin in vivo, and UV-irradiated human skin fibroblasts. Knockdown of CYR61 significantly attenuates UV irradiation-induced inhibition of type-I procollagen and upregulation of MMP-1. Determination of CYR61 mRNA and protein indicates that the primary mechanism of CYR61 induction by UV irradiation is transcriptional. Analysis of CYR61 proximal promoter showed that a sequence conforming to the consensus binding site for transcription factor activator protein-1 (AP-1) is required for promoter activity. UV irradiation increased the binding of AP-1-family members c-Jun and c-Fos to this AP-1 site. Furthermore, functional blockade of c-Jun or knockdown of c-Jun significantly reduced the UV irradiation-induced activation of CYR61 promoter and CYR61 gene expression. These data show that CYR61 is transcriptionally regulated by UV irradiation through transcription factor AP-1, and mediates altered collagen homeostasis that occurs in response to UV irradiation in human skin fibroblasts.

  13. Laser Irradiation-Induced DNA Methylation Changes Are Heritable and Accompanied with Transpositional Activation of mPing in Rice

    PubMed Central

    Li, Siyuan; Xia, Qiong; Wang, Fang; Yu, Xiaoming; Ma, Jian; Kou, Hongping; Lin, Xiuyun; Gao, Xiang; Liu, Bao

    2017-01-01

    DNA methylation is an integral component of the epigenetic code in most higher eukaryotes. Exploring the extent to which DNA methylation can be altered under a specific condition and its heritability is important for elucidating the biological functions of this epigenetic modification. Here, we conducted MSAP analysis of rice plants with altered phenotypes subsequent to a low-dose Nd3+YAG laser irradiation. We found that all four methylation patterns at the 5′-CCGG sites that are analyzable by MSAP showed substantial changes in the immediately treated M0 plants. Interestingly, the frequencies of hypo- and hypermethylation were of similar extents, which largely offset each other and render the total methylation levels unchanged. Further analysis revealed that the altered methylation patterns were meiotically heritable to at least the M2 generation but accompanied with further changes in each generation. The methylation changes and their heritability of the metastable epigenetic state were verified by bisulfite sequencing of portion of the retrotranspon, Tos17, an established locus for assessing DNA methylation liability in rice. Real-time PCR assay indicated that the expression of various methylation-related chromatin genes was perturbed, and a Pearson correlation analysis showed that many of these genes, especially two AGOs (AGO4-1 and AGO4-2), were significantly correlated with the methylation pattern alterations. In addition, excisions of a MITE transposon, mPing, occurred rampantly in the laser irradiated plants and their progenies. Together, our results indicate that heritable DNA methylation changes can be readily induced by low-dose laser irradiation, and which can be accompanied by transpostional activation of transposable elements. PMID:28377781

  14. Galantamine reverses scopolamine-induced behavioral alterations in Dugesia tigrina.

    PubMed

    Ramakrishnan, Latha; Amatya, Christina; DeSaer, Cassie J; Dalhoff, Zachary; Eggerichs, Michael R

    2014-09-01

    In planaria (Dugesia tigrina), scopolamine, a nonselective muscarinic receptor antagonist, induced distinct behaviors of attenuated motility and C-like hyperactivity. Planarian locomotor velocity (pLMV) displayed a dose-dependent negative correlation with scopolamine concentrations from 0.001 to 1.0 mM, and a further increase in scopolamine concentration to 2.25 mM did not further decrease pLMV. Planarian hyperactivity counts was dose-dependently increased following pretreatment with scopolamine concentrations from 0.001 to 0.5 mM and then decreased for scopolamine concentrations ≥ 1 mM. Planarian learning and memory investigated using classical Pavlovian conditioning experiments demonstrated that scopolamine (1 mM) negatively influenced associative learning indicated by a significant decrease in % positive behaviors from 86 % (control) to 14 % (1 mM scopolamine) and similarly altered memory retention, which is indicated by a decrease in % positive behaviors from 69 % (control) to 27 % (1 mM scopolamine). Galantamine demonstrated a complex behavior in planarian motility experiments since co-application of low concentrations of galantamine (0.001 and 0.01 mM) protected planaria against 1 mM scopolamine-induced motility impairments; however, pLMV was significantly decreased when planaria were tested in the presence of 0.1 mM galantamine alone. Effects of co-treatment of scopolamine and galantamine on memory retention in planaria via classical Pavlovian conditioning experiments showed that galantamine (0.01 mM) partially reversed scopolamine (1 mM)-induced memory deficits in planaria as the % positive behaviors increased from 27 to 63 %. The results demonstrate, for the first time in planaria, scopolamine's effects in causing learning and memory impairments and galantamine's ability in reversing scopolamine-induced memory impairments.

  15. Direct experimental evidence for differing reactivity alterations of minerals following irradiation. The case of calcite and quartz

    DOE PAGES

    Pignatelli, Isabella; Kumar, Aditya; Field, Kevin G.; ...

    2016-01-29

    Concrete, used in the construction of nuclear power plants (NPPs), may be exposed to radiation emanating from the reactor core. Until recently, concrete has been assumed immune to radiation exposure. Direct evidence acquired on Ar+ -ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. More specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%,more » and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica. However, calcite shows little change in dissolution rate - although its density noted to reduce by 9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral's atomic network that is characterized by the number of topological constraints (nc) that are imposed on the atoms in the network. Our outcomes have major implications on the durability of concrete structural elements formed with calcitic or quartzitic aggregates in nuclear power plants.« less

  16. Direct experimental evidence for differing reactivity alterations of minerals following irradiation. The case of calcite and quartz

    SciTech Connect

    Pignatelli, Isabella; Kumar, Aditya; Field, Kevin G.; Wang, Bu; Yu, Yingtian; Le Pape, Yann; Bauchy, Mathieu; Sant, Gaurav

    2016-01-29

    Concrete, used in the construction of nuclear power plants (NPPs), may be exposed to radiation emanating from the reactor core. Until recently, concrete has been assumed immune to radiation exposure. Direct evidence acquired on Ar+ -ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. More specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%, and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica. However, calcite shows little change in dissolution rate - although its density noted to reduce by 9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral's atomic network that is characterized by the number of topological constraints (nc) that are imposed on the atoms in the network. Our outcomes have major implications on the durability of concrete structural elements formed with calcitic or quartzitic aggregates in nuclear power plants.

  17. Cellular proliferation and infiltration following interstitial irradiation of normal dog brain is altered by an inhibitor of polyamine synthesis

    SciTech Connect

    Fike, J.R.; Gobbel, G.T.; Chou, D.

    1995-07-15

    The objectives of this study were to quantitatively define proliferative and infiltrative cell responses after focal {sup 125}I irradiation of normal brain, and to determine the effects of an intravenous infusion of {alpha}-defluoromethylornithine (DFMO) on those responses. Adult beagle dogs were irradiated using high activity {sup 125}I sources. Cellular responses were quantified using a histomorphometric analysis. After radiation alone, cellular events included a substantial acute inflammatory response followed by increased BrdU labeling and progressive increases in numbers of capillaries and astrocytes. {alpha}-Difluoromethylornithine treatment significantly affected the measured cell responses. As in controls, an early inflammatory response was measured, but after 2 weeks there were more PMNs/unit area than in controls. The onset of measurable BrdU labeling was delayed in DFMO-treated animals, and the magnitude of labeling was significantly reduced. Increases in astrocyte and vessel numbers/mm{sup 2} were observed after a 2-week delay. At the site of implant, astrocytes from DFMO-treated dogs were significantly smaller than those from controls. There is substantial cell proliferation and infiltration in response to interstitial irradiation of normal brain, and these responses are significantly altered by DFMO treatment. Although the precise mechanisms by which DFMO exerts its effects in this model are not known, the results from this study suggest that modification of radiation injury may be possible by manipulating the response of normal cells to injury. 57 refs., 6 figs.

  18. Direct Experimental Evidence for Differing Reactivity Alterations of Minerals following Irradiation: The Case of Calcite and Quartz

    PubMed Central

    Pignatelli, Isabella; Kumar, Aditya; Field, Kevin G.; Wang, Bu; Yu, Yingtian; Le Pape, Yann; Bauchy, Mathieu; Sant, Gaurav

    2016-01-01

    Concrete, used in the construction of nuclear power plants (NPPs), may be exposed to radiation emanating from the reactor core. Until recently, concrete has been assumed immune to radiation exposure. Direct evidence acquired on Ar+-ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. More specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%, and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica. Calcite however, shows little change in dissolution rate - although its density noted to reduce by ≈9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral’s atomic network that is characterized by the number of topological constraints (nc) that are imposed on the atoms in the network. The outcomes have major implications on the durability of concrete structural elements formed with calcite or quartz bearing aggregates in nuclear power plants. PMID:26822012

  19. Direct Experimental Evidence for Differing Reactivity Alterations of Minerals following Irradiation: The Case of Calcite and Quartz.

    PubMed

    Pignatelli, Isabella; Kumar, Aditya; Field, Kevin G; Wang, Bu; Yu, Yingtian; Le Pape, Yann; Bauchy, Mathieu; Sant, Gaurav

    2016-01-29

    Concrete, used in the construction of nuclear power plants (NPPs), may be exposed to radiation emanating from the reactor core. Until recently, concrete has been assumed immune to radiation exposure. Direct evidence acquired on Ar(+)-ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. More specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%, and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica. Calcite however, shows little change in dissolution rate - although its density noted to reduce by ≈9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral's atomic network that is characterized by the number of topological constraints (nc) that are imposed on the atoms in the network. The outcomes have major implications on the durability of concrete structural elements formed with calcite or quartz bearing aggregates in nuclear power plants.

  20. Direct Experimental Evidence for Differing Reactivity Alterations of Minerals following Irradiation: The Case of Calcite and Quartz

    NASA Astrophysics Data System (ADS)

    Pignatelli, Isabella; Kumar, Aditya; Field, Kevin G.; Wang, Bu; Yu, Yingtian; Le Pape, Yann; Bauchy, Mathieu; Sant, Gaurav

    2016-01-01

    Concrete, used in the construction of nuclear power plants (NPPs), may be exposed to radiation emanating from the reactor core. Until recently, concrete has been assumed immune to radiation exposure. Direct evidence acquired on Ar+-ion irradiated calcite and quartz indicates, on the contrary, that, such minerals, which constitute aggregates in concrete, may be significantly altered by irradiation. More specifically, while quartz undergoes disordering of its atomic structure resulting in a near complete lack of periodicity, calcite only experiences random rotations, and distortions of its carbonate groups. As a result, irradiated quartz shows a reduction in density of around 15%, and an increase in chemical reactivity, described by its dissolution rate, similar to a glassy silica. Calcite however, shows little change in dissolution rate - although its density noted to reduce by ≈9%. These differences are correlated with the nature of bonds in these minerals, i.e., being dominantly ionic or covalent, and the rigidity of the mineral’s atomic network that is characterized by the number of topological constraints (nc) that are imposed on the atoms in the network. The outcomes have major implications on the durability of concrete structural elements formed with calcite or quartz bearing aggregates in nuclear power plants.

  1. Fracture-aperture alteration induced by calcite precipitation

    NASA Astrophysics Data System (ADS)

    Jones, T.; Detwiler, R. L.

    2013-12-01

    Mineral precipitation significantly alters the transport properties of fractured rock. Chemical solubility gradients that favor precipitation induce mineral growth, which decreases the local aperture and alters preferential flow paths. Understanding the resulting development of spatial heterogeneities is necessary to predict the evolution of transport properties in the subsurface. We present experimental results that quantify the relationship between mineral precipitation and aperture alteration in a transparent analog fracture, 7.62cm x 7.62cm, with a uniform aperture of ~200 μm. Prior to flow experiments, a pump circulated a super-saturated calcite solution over the bottom glass, coating the glass surface with calcite. This method of seeding resulted in clusters of calcite crystals with large reactive surface area and provided micro-scale variability in the aperture field. A continuous flow syringe pump injected a reactive fluid into the fracture at 0.5 ml/min. The fluid was a mixture of sodium bicarbonate (NaHCO3, 0.02M) and calcium chloride (CaCl2 0.0004M) with a saturation index, Ω, of 8.51 with respect to calcite. A strobed LED panel backlit the fracture and a high-resolution CCD camera monitored changes in transmitted light intensity. Light transmission techniques provided a quantitative measurement of fracture aperture over the flow field. Results from these preliminary experiments showed growth near the inlet of the fracture, with decreasing precipitation rates in the flow direction. Over a period of two weeks, the fracture aperture decreased by 17% within the first 4mm of the inlet. Newly precipitated calcite bridged individual crystal clusters and smoothed the reacting surface. This observation is an interesting contradiction to the expectation of surface roughening induced by mineral growth. Additionally, the aperture decreased uniformly across the width of the fracture due to the initial aperture distribution. Future experiments of precipitation

  2. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation.

    PubMed

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  3. Nitric oxide-mediated bystander signal transduction induced by heavy-ion microbeam irradiation

    NASA Astrophysics Data System (ADS)

    Tomita, Masanori; Matsumoto, Hideki; Funayama, Tomoo; Yokota, Yuichiro; Otsuka, Kensuke; Maeda, Munetoshi; Kobayashi, Yasuhiko

    2015-07-01

    In general, a radiation-induced bystander response is known to be a cellular response induced in non-irradiated cells after receiving bystander signaling factors released from directly irradiated cells within a cell population. Bystander responses induced by high-linear energy transfer (LET) heavy ions at low fluence are an important health problem for astronauts in space. Bystander responses are mediated via physical cell-cell contact, such as gap-junction intercellular communication (GJIC) and/or diffusive factors released into the medium in cell culture conditions. Nitric oxide (NO) is a well-known major initiator/mediator of intercellular signaling within culture medium during bystander responses. In this study, we investigated the NO-mediated bystander signal transduction induced by high-LET argon (Ar)-ion microbeam irradiation of normal human fibroblasts. Foci formation by DNA double-strand break repair proteins was induced in non-irradiated cells, which were co-cultured with those irradiated by high-LET Ar-ion microbeams in the same culture plate. Foci formation was suppressed significantly by pretreatment with an NO scavenger. Furthermore, NO-mediated reproductive cell death was also induced in bystander cells. Phosphorylation of NF-κB and Akt were induced during NO-mediated bystander signaling in the irradiated and bystander cells. However, the activation of these proteins depended on the incubation time after irradiation. The accumulation of cyclooxygenase-2 (COX-2), a downstream target of NO and NF-κB, was observed in the bystander cells 6 h after irradiation but not in the directly irradiated cells. Our findings suggest that Akt- and NF-κB-dependent signaling pathways involving COX-2 play important roles in NO-mediated high-LET heavy-ion-induced bystander responses. In addition, COX-2 may be used as a molecular marker of high-LET heavy-ion-induced bystander cells to distinguish them from directly irradiated cells, although this may depend on the time

  4. Neonatal Irradiation Leads to Persistent Proteome Alterations Involved in Synaptic Plasticity in the Mouse Hippocampus and Cortex.

    PubMed

    Kempf, Stefan J; Sepe, Sara; von Toerne, Christine; Janik, Dirk; Neff, Frauke; Hauck, Stefanie M; Atkinson, Michael J; Mastroberardino, Pier G; Tapio, Soile

    2015-11-06

    Recent epidemiological data indicate that radiation doses as low as those used in computer tomography may result in long-term neurocognitive side effects. The aim of this study was to elucidate long-term molecular alterations related to memory formation in the brain after low and moderate doses of γ radiation. Female C57BL/6J mice were irradiated on postnatal day 10 with total body doses of 0.1, 0.5, or 2.0 Gy; the control group was sham-irradiated. The proteome analysis of hippocampus, cortex, and synaptosomes isolated from these brain regions indicated changes in ephrin-related, RhoGDI, and axonal guidance signaling. Immunoblotting and miRNA-quantification demonstrated an imbalance in the synapse morphology-related Rac1-Cofilin pathway and long-term potentiation-related cAMP response element-binding protein (CREB) signaling. Proteome profiling also showed impaired oxidative phosphorylation, especially in the synaptic mitochondria. This was accompanied by an early (4 weeks) reduction of mitochondrial respiration capacity in the hippocampus. Although the respiratory capacity was restored by 24 weeks, the number of deregulated mitochondrial complex proteins was increased at this time. All observed changes were significant at doses of 0.5 and 2.0 Gy but not at 0.1 Gy. This study strongly suggests that ionizing radiation at the neonatal state triggers persistent proteomic alterations associated with synaptic impairment.

  5. Melatonin protects rat liver against irradiation-induced oxidative injury.

    PubMed

    Koc, Mehmet; Taysi, Seyithan; Buyukokuroglu, Mehmet Emin; Bakan, Nuri

    2003-09-01

    The aim of this study was to investigate the antioxidant roles of different doses of melatonin (5 and 10 mg x kg (-1) ) against gamma-irradiation-caused oxidative damage in liver tissue after total body irradiation (TBI) with a single dose of 6.0 Gy. Fifty adult rats were divided into 5 equal groups, 10 rats each. Groups I and II were injected with 5 and 10 mg x kg (-1) of melatonin, and group III was injected with an isotonic NaCl solution. Group IV was injected with only 5 mg x kg (-1) of melatonin. Group V was reserved as a sham control. Following a 30-min-period, 6.0 Gy TBI was given to groups 1, 2 and 3 in a single fraction. The liver malondialdehyde (MDA) levels, super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured in all groups. TBI resulted in a significant increase in the liver tissue MDA levels and a decrease of SOD and GSH-Px activities. The results demonstrated that the liver tissue MDA levels in irradiated rats that were pretreated with melatonin (5 or 10 mg x kg (-1) ) were significantly decreased, while the SOD and GSH-Px activities were significantly increased. Decreasing the MDA levels by melatonin was dose dependent, but the liver tissue SOD and GSH activities were not. The data obtained in this study suggest that melatonin administration prior to irradiation may prevent liver damage by irradiation.

  6. Irradiation-induced composition patterns in binary solid solutions

    SciTech Connect

    Dubey, Santosh; El-Azab, Anter

    2013-09-28

    A theoretical/computational model for the irradiation-driven compositional instabilities in binary solid solutions has been developed. The model is suitable for investigating the behavior of structural alloys and metallic nuclear fuels in a reactor environment as well as the response of alloy thin films to ion beam irradiation. The model is based on a set of reaction-diffusion equations for the dynamics of vacancies, interstitials, and lattice atoms under irradiation. The dynamics of these species includes the stochastic generation of defects by collision cascades as well as the defect reactions and diffusion. The atomic fluxes in this model are derived based on the transitions of lattice defects. The set of reaction-diffusion equations are stiff, hence a stiffly stable method, also known as the Gear method, has been used to numerically approximate the equations. For the Cu-Au alloy in the solid solution regime, the model results demonstrate the formation of compositional patterns under high-temperature particle irradiation, with Fourier space properties (Fourier spectrum, average wavelength, and wavevector) depending on the cascade damage characteristics, average composition, and irradiation temperature.

  7. Heavy ion irradiation induced dislocation loops in AREVA's M5® alloy

    NASA Astrophysics Data System (ADS)

    Hengstler-Eger, R. M.; Baldo, P.; Beck, L.; Dorner, J.; Ertl, K.; Hoffmann, P. B.; Hugenschmidt, C.; Kirk, M. A.; Petry, W.; Pikart, P.; Rempel, A.

    2012-04-01

    Pressurized water reactor (PWR) Zr-based alloy structural materials show creep and growth under neutron irradiation as a consequence of the irradiation induced microstructural changes in the alloy. A better scientific understanding of these microstructural processes can improve simulation programs for structural component deformation and simplify the development of advanced deformation resistant alloys. As in-pile irradiation leads to high material activation and requires long irradiation times, the objective of this work was to study whether ion irradiation is an applicable method to simulate typical PWR neutron damage in Zr-based alloys, with AREVA's M5® alloy as reference material. The irradiated specimens were studied by electron backscatter diffraction (EBSD), positron Doppler broadening spectroscopy (DBS) and in situ transmission electron microscopy (TEM) at different dose levels and temperatures. The irradiation induced microstructure consisted of - and -type dislocation loops with their characteristics corresponding to typical neutron damage in Zr-based alloys; it can thus be concluded that heavy ion irradiation under the chosen conditions is an excellent method to simulate PWR neutron damage.

  8. In Vivo Bystander Effect: Cranial X-Irradiation Leads to Elevated DNA Damage, Altered Cellular Proliferation and Apoptosis, and Increased p53 Levels in Shielded Spleen

    SciTech Connect

    Koturbash, Igor; Loree, Jonathan; Kutanzi, Kristy; Koganow, Clayton; Pogribny, Igor; Kovalchuk, Olga

    2008-02-01

    Purpose: It is well accepted that irradiated cells may 'forward' genome instability to nonirradiated neighboring cells, giving rise to the 'bystander effect' phenomenon. Although bystander effects were well studied by using cell cultures, data for somatic bystander effects in vivo are relatively scarce. Methods and Materials: We set out to analyze the existence and molecular nature of bystander effects in a radiation target-organ spleen by using a mouse model. The animal's head was exposed to X-rays while the remainder of the body was completely protected by a medical-grade shield. Using immunohistochemistry, we addressed levels of DNA damage, cellular proliferation, apoptosis, and p53 protein in the spleen of control animals and completely exposed and head-exposed/body bystander animals. Results: We found that localized head radiation exposure led to the induction of bystander effects in the lead-shielded distant spleen tissue. Namely, cranial irradiation led to increased levels of DNA damage and p53 expression and also altered levels of cellular proliferation and apoptosis in bystander spleen tissue. The observed bystander changes were not caused by radiation scattering and were observed in two different mouse strains; C57BL/6 and BALB/c. Conclusion: Our study proves that bystander effects occur in the distant somatic organs on localized exposures. Additional studies are required to characterize the nature of an enigmatic bystander signal and analyze the long-term persistence of these effects and possible contribution of radiation-induced bystander effects to secondary radiation carcinogenesis.

  9. [Low level laser irradiation in the visible spectra induces HeLa cells proliferation].

    PubMed

    Yang, Hong-qin; Wang, Yu-hua; Chen, Jiang-xu; Zheng, Li-qin; Xie, Shu-sen

    2012-04-01

    The aim of this in vitro study was to evaluate the effects of low level laser irradiation on the proliferation of HeLa cells using 405 nm diode laser, 514 nm argon laser, 633 nm He-Ne laser, or 785 nm diode laser, The cells were seeded on 96-well microplates for 24 h in 5% fetal bovine serum containing medium, then irradiated with the laser at dose of 100 and 1 000 J x m(-2), respectively. At the time point of 24, 48, 72 h after irradiation, cell viability was assessed by MTT assay. The results show that 405, 633 and 785 nm laser irradiation induces wavelength-dependent and time-dependent proliferation. 633 nm laser irradiation results in a stimulatory proliferation effect that is most significant, whereas 514 nm laser irradiation produces little increase in cell proliferation. Low level laser irradiation increases cell proliferation in a dose-dependent manner. 1 000 J x m(-2) laser irradiation is more effective in increasing cell proliferation than 100 J x m(-2) laser irradiation using 405 nm diode laser, 633 nm He-Ne laser, or 785 nm diode laser, but not as effective as using 514 nm argon laser.

  10. microRNA Alterations Driving Acute and Late Stages of Radiation-Induced Fibrosis in a Murine Skin Model

    SciTech Connect

    Simone, Brittany A.; Ly, David; Savage, Jason E.; Hewitt, Stephen M.; Dan, Tu D.; Ylaya, Kris; Shankavaram, Uma; Lim, Meng; Jin, Lianjin; Camphausen, Kevin; Mitchell, James B.; Simone, Nicole L.

    2014-09-01

    Purpose: Although ionizing radiation is critical in treating cancer, radiation-induced fibrosis (RIF) can have a devastating impact on patients' quality of life. The molecular changes leading to radiation-induced fibrosis must be elucidated so that novel treatments can be designed. Methods and Materials: To determine whether microRNAs (miRs) could be responsible for RIF, the fibrotic process was induced in the right hind legs of 9-week old CH3 mice by a single-fraction dose of irradiation to 35 Gy, and the left leg served as an unirradiated control. Fibrosis was quantified by measurements of leg length compared with control leg length. By 120 days after irradiation, the irradiated legs were 20% (P=.013) shorter on average than were the control legs. Results: Tissue analysis was done on muscle, skin, and subcutaneous tissue from irradiated and control legs. Fibrosis was noted on both gross and histologic examination by use of a pentachrome stain. Microarrays were performed at various times after irradiation, including 7 days, 14 days, 50 days, 90 days, and 120 days after irradiation. miR-15a, miR-21, miR-30a, and miR-34a were the miRs with the most significant alteration by array with miR-34a, proving most significant on confirmation by reverse transcriptase polymerase chain reaction, c-Met, a known effector of fibrosis and downstream molecule of miR-34a, was evaluated by use of 2 cell lines: HCT116 and 1522. The cell lines were exposed to various stressors to induce miR changes, specifically ionizing radiation. Additionally, in vitro transfections with pre-miRs and anti-miRs confirmed the relationship of miR-34a and c-Met. Conclusions: Our data demonstrate an inverse relationship with miR-34a and c-Met; the upregulation of miR-34a in RIF causes inhibition of c-Met production. miRs may play a role in RIF; in particular, miR-34a should be investigated as a potential target to prevent or treat this devastating side effect of irradiation.

  11. Analysis of chromosomal alterations induced by asbestos and ceramic fibers.

    PubMed

    Dopp, E; Schiffmann, D

    1998-08-01

    increase of chromosomal breakage in the pericentric heterochromatin regions of chromosomes 1 and 9 in AFC after exposure to asbestos and ceramic fibers. The number of hyperdiploid cells was also significantly increased. These results show that asbestos as well as ceramic fibers are inducers of structural and numerical chromosomal alterations.

  12. The Role of DNA Methylation Changes in Radiation-Induced Transgenerational Genomic Instability and Bystander Effects in cranial irradiated Mice

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Sun, Yeqing; Gao, Yinglong; Zhang, Baodong

    Heavy-ion radiation could lead to genome instability in the germline, and therefore to transgenerational genome and epigenome instability in offspring of exposed males. The exact mechanisms of radiation-induced genome instability in directly exposed and in bystander organ remain obscure, yet accumulating evidence points to the role of DNA methylation changes in genome instability development. The potential of localized body-part exposures to affect the germline and thus induce genome and epigenome changes in the progeny has not been studied. To investigate whether or not the paternal cranial irradiation can exert deleterious changes in the protected germline and the offsprings, we studied the alteration of DNA methylation in the shielded testes tissue. Here we report that the localized paternal cranial irradiation results in a significant altered DNA methylation in sperm cells and leads to a profound epigenetic dysregulation in the unexposed progeny conceived 3 months after paternal exposure. The possible molecular mechanisms and biological consequences of the observed changes are discussed. Keywords: Heavy-ion radiation; Transgenerational effect; Genomic Instability Bystander Effects; DNA methylation.

  13. Distinct photoresponse in graphene induced by laser irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Wen Hui; Nan, Hai Yan; Liu, Qi; Liang, Zheng; Yu, Zhi Hao; Liu, Feng Yuan; Hu, Wei Da; Zhang, Wei; Wang, Xin Ran; Ni, Zhen Hua

    2015-01-01

    The graphene-based photodetector with tunable p-p+-p junctions was fabricated through a simple laser irradiation process. Distinct photoresponse was observed at the graphene (G)-laser irradiated graphene (LIG) junction by scanning photocurrent measurements, and its magnitude can be modulated as a result of a positive correlation between the photocurrent and doping concentration in LIG region. Detailed investigation suggests that the photo-thermoelectric effect, instead of the photovoltaic effect, dominates the photocurrent generation at the G-LIG junctions. Such a simple and low-cost technique offers an alternative way for the fabrication of graphene-based optoelectronic devices.

  14. Irradiation-induced heterogeneous nucleation in uranium dioxide

    NASA Astrophysics Data System (ADS)

    Martin, G.; Garcia, P.; Sabathier, C.; Van Brutzel, L.; Dorado, B.; Garrido, F.; Maillard, S.

    2010-07-01

    Using classical molecular dynamics simulations, we have studied the first stages of defect cluster formation resulting from 10 keV displacement cascades in uranium dioxide. Nanometre size cavities and dislocation loops are shown to appear as a result of the irradiation process. A specifically designed TEM experiment involving He implanted thin foils have also been carried out to support this modelling work. These results, in conjunction with several other observations taken from the literature of ion implanted or neutron irradiated uranium dioxide, suggest a radiation damage controlled heterogeneous mechanism for insoluble fission product segregation in UO 2.

  15. Distinct photoresponse in graphene induced by laser irradiation

    SciTech Connect

    Wang, Wen Hui; Nan, Hai Yan; Liu, Qi; Ni, Zhen Hua; Liang, Zheng; Yu, Zhi Hao; Liu, Feng Yuan; Wang, Xin Ran; Hu, Wei Da; Zhang, Wei

    2015-01-12

    The graphene-based photodetector with tunable p-p{sup +}-p junctions was fabricated through a simple laser irradiation process. Distinct photoresponse was observed at the graphene (G)-laser irradiated graphene (LIG) junction by scanning photocurrent measurements, and its magnitude can be modulated as a result of a positive correlation between the photocurrent and doping concentration in LIG region. Detailed investigation suggests that the photo-thermoelectric effect, instead of the photovoltaic effect, dominates the photocurrent generation at the G-LIG junctions. Such a simple and low-cost technique offers an alternative way for the fabrication of graphene-based optoelectronic devices.

  16. Native and irradiation-induced monovacancies in n -type and semi-insulating GaAs

    SciTech Connect

    Corbel, C.; Pierre, F. ); Hautojaervi, P.; Saarinen, K. ); Moser, P. )

    1990-05-15

    Defects induced by electron irradiation in semi-insulating and {ital n}-type GaAs crystals have been characterized by positron-lifetime measurements. We conclude that electron irradiation with energies of 1.5--3 MeV produces negative monovacancies and negative ions at low and room temperature. The results also show that the native monovacancy defects in lightly {ital n}-type GaAs change their properties under irradiation. We relate this change to the existence of an ionization level {minus}{r arrow}0 or 0{r arrow}+ of the native monovacancy defects in the upper half of the band gap. We propose that irradiation produces negative Ga{sub As} antisites and negative {ital V}{sub Ga} vacancies. In {ital n}-type GaAs the behavior of the native defects under irradiation is in agreement with their earlier assignment to {ital V}{sub As}.

  17. Laser irradiation affects enzymatic antioxidant system of streptozotocin-induced diabetic rats.

    PubMed

    Ibuki, Flavia Kazue; Simões, Alyne; Nicolau, José; Nogueira, Fernando Neves

    2013-05-01

    The aim of the present study was to analyze the effect of low-power laser irradiation in the antioxidant enzymatic system of submandibular (SMG) and parotid (PG) salivary glands of streptozotocin-induced diabetic rats. The animals were randomly divided into six groups: three diabetic groups (D0, D5, and D20) and three non-diabetic groups (C0, C5, and C20), according to laser dose received (0, 5, and 20 J/cm(2), respectively). Areas of approximately 1 cm(2) were demarcated in the salivary glands (each parotid and both submandibular glands) and after irradiated according to Simões et.al. (Lasers Med Sci 24:202-208, 2009). A diode laser (660 nm/100 mW) was used, with laser beam spot of 0.0177 cm(2). The group treated with 5 J/cm(2) laser dose was subjected to irradiation for 1 min and 4 s (total irradiation time) and the group treated with 20 J/cm(2) laser dose was subjected to irradiation for 4 min and 16 s. Twenty-four hours after irradiation the animals were euthanized and the salivary glands were removed for biochemical analysis. The total antioxidant values (TA), the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase enzymes were determined. SOD and CAT activities, as well as TA were higher in SMG of irradiated diabetic rats. However, in SMG of non-diabetic rats, laser irradiation decreased TA values and led to an increase in the CAT activity. In addition, there was a decrease in the activity of CAT in PG of diabetic and non-diabetic animals after laser irradiation. According to the results of the present study, low-power laser irradiation can affect the enzymatic antioxidant system of salivary glands of streptozotocin-induced diabetic rats.

  18. Radiation-Induced Alterations in Mouse Brain Development Characterized by Magnetic Resonance Imaging

    SciTech Connect

    Gazdzinski, Lisa M.; Cormier, Kyle; Lu, Fred G.; Lerch, Jason P.; Wong, C. Shun; Nieman, Brian J.

    2012-12-01

    Purpose: The purpose of this study was to identify regions of altered development in the mouse brain after cranial irradiation using longitudinal magnetic resonance imaging (MRI). Methods and Materials: Female C57Bl/6 mice received a whole-brain radiation dose of 7 Gy at an infant-equivalent age of 2.5 weeks. MRI was performed before irradiation and at 3 time points following irradiation. Deformation-based morphometry was used to quantify volume and growth rate changes following irradiation. Results: Widespread developmental deficits were observed in both white and gray matter regions following irradiation. Most of the affected brain regions suffered an initial volume deficit followed by growth at a normal rate, remaining smaller in irradiated brains compared with controls at all time points examined. The one exception was the olfactory bulb, which in addition to an early volume deficit, grew at a slower rate thereafter, resulting in a progressive volume deficit relative to controls. Immunohistochemical assessment revealed demyelination in white matter and loss of neural progenitor cells in the subgranular zone of the dentate gyrus and subventricular zone. Conclusions: MRI can detect regional differences in neuroanatomy and brain growth after whole-brain irradiation in the developing mouse. Developmental deficits in neuroanatomy persist, or even progress, and may serve as useful markers of late effects in mouse models. The high-throughput evaluation of brain development enabled by these methods may allow testing of strategies to mitigate late effects after pediatric cranial irradiation.

  19. Irradiation-induced permeability in pyrocarbon coatings. Final report of work conducted under PWS FD-12

    SciTech Connect

    Kania, M.J.; Thiele, B.A.; Homan, F.J.

    1982-10-01

    Two US irradiation experiments were planned to provide information to supplement data from the German program on irradiation-induced permeability in pyrocarbon coatings. Hopefully, the data from both programs could be combined to define the onset of neutron-induced permeability in a variety of Biso coatings produced with different process variables (coating temperature, coating gases, and coating rates). The effort was not successful. None of the preirradiation characterization procedures were able to adequately predict irradiation performance. A large amount of within-batch scatter was observed in the fission gas and cesium release data along with significant within-batch variation in coating properties. Additional preirradiation characterization might result in a procedure that could successfully predict irradiation performance, but little can be done about the within-batch variation in coating properties. This variation is probably the result of random movement of particles within the coating furnace during pyrocarbon deposition. 19 figures, 4 tables.

  20. Study on DNA Damage Induced by Neon Beam Irradiation in Saccharomyces Cerevisiae

    NASA Astrophysics Data System (ADS)

    Lu, Dong; Li, Wenjian; Wu, Xin; Wang, Jufang; Ma, Shuang; Liu, Qingfang; He, Jinyu; Jing, Xigang; Ding, Nan; Dai, Zhongying; Zhou, Jianping

    2010-12-01

    Yeast strain Saccharomyces cerevisiae was irradiated with different doses of 85 MeV/u 20Ne10+ to investigate DNA damage induced by heavy ion beam in eukaryotic microorganism. The survival rate, DNA double strand breaks (DSBs) and DNA polymorphic were tested after irradiation. The results showed that there were substantial differences in DNA between the control and irradiated samples. At the dose of 40 Gy, the yeast cell survival rate approached 50%, DNA double-strand breaks were barely detectable, and significant DNA polymorphism was observed. The alcohol dehydrogenase II gene was amplified and sequenced. It was observed that base changes in the mutant were mainly transversions of T→G and T→C. It can be concluded that heavy ion beam irradiation can lead to change in single gene and may be an effective way to induce mutation.

  1. [Induced radioactivity in irradiated foods by X ray or gamma ray].

    PubMed

    Miyahara, Makoto

    2007-01-01

    In the course of the archival studies on safety of irradiated foods by the US Army, experimental records conducted by Glass & Smith, and Kruger & Wilson were investigated, based on our experimental experience. Food irradiation by Co-60 or 4 approximately 24MeV X ray can induce small amount of radioactivity in the foods. The principal mechanisms of the nuclear reactions are (gamma, n). The resulting nuclear products found in irradiated target solutions were Ba-135m, Pb-204m, Hg-199m, Ag-107m,Ag-109m, Cd-111m,Cd-113m, Sn-117m, Sn-119m, Sr-87m, Nb-93m, In113m, In-115m, Te-123m, Te-125m, Lu-178m Hf-160m by the (gamma, n) reaction. The total radio-activities in beef, bacon, shrimp, chicken, and green beans were counted at 60 days after irradiation by Cs-137, Co-60, and fuel element. The activities more than background were found in irradiated bacon and beef by Co-60. and activities were found in most foods when foods were irradiated by high energy X ray and the fuel element. The results were understood as the neutron activation by (gamma, n) or (n, gamma) reaction. Therefore, high energy X ray and spent fuel element were not used for food irradiation. As the results of this study Co-60 has been used with small amount of induced radioactivity in food.

  2. Neutron irradiation induced microstructural changes in NBG-18 and IG-110 nuclear graphites

    SciTech Connect

    Karthik, Chinnathambi; Kane, Joshua; Butt, Darryl P.; Windes, William E.; Ubic, Rick

    2015-05-01

    This paper reports the neutron-irradiation-induced effects on the microstructure of NBG-18 and IG-110 nuclear graphites. The high-temperature neutron irradiation at two different irradiation conditions was carried out at the Advanced Test Reactor National User Facility at the Idaho National Laboratory. NBG-18 samples were irradiated to 1.54 dpa and 6.78 dpa at 430 °C and 678 °C respectively. IG-110 samples were irradiated to 1.91 dpa and 6.70 dpa at 451 °C and 674 °C respectively. Bright-field transmission electron microscopy imaging was used to study the changes in different microstructural components such as filler particles, microcracks, binder and quinoline-insoluble (QI) particles. Significant changes have been observed in samples irradiated to about 6.7 dpa. The closing of pre-existing microcracks was observed in both the filler and the binder phases. The binder phase exhibited substantial densification with near complete elimination of the microcracks. The QI particles embedded in the binder phase exhibited a complete microstructural transformation from rosettes to highly crystalline solid spheres. The lattice images indicate the formation of edge dislocations as well as extended line defects bridging the adjacent basal planes. The positive climb of these dislocations has been identified as the main contributor to the irradiation-induced swelling of the graphite lattice.

  3. 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.

  4. Drought induces alterations in the stomatal development program in Populus.

    PubMed

    Hamanishi, Erin T; Thomas, Barb R; Campbell, Malcolm M

    2012-08-01

    Much is known about the physiological control of stomatal aperture as a means by which plants adjust to water availability. By contrast, the role played by the modulation of stomatal development to limit water loss has received much less attention. The control of stomatal development in response to water deprivation in the genus Populus is explored here. Drought induced declines in stomatal conductance as well as an alteration in stomatal development in two genotypes of Populus balsamifera. Leaves that developed under water-deficit conditions had lower stomatal indices than leaves that developed under well-watered conditions. Transcript abundance of genes that could hypothetically underpin drought-responsive changes in stomatal development was examined, in two genotypes, across six time points, under two conditions, well-watered and with water deficit. Populus homologues of STOMAGEN, ERECTA (ER), STOMATA DENSITY AND DISTRIBUTION 1 (SDD1), and FAMA had variable transcript abundance patterns congruent with their role in the modulation of stomatal development in response to drought. Conversely, there was no significant variation in transcript abundance between genotypes or treatments for the Populus homologues of YODA (YDA) and TOO MANY MOUTHS (TMM). The findings highlight the role that could be played by stomatal development during leaf expansion as a longer term means by which to limit water loss from leaves. Moreover, the results point to the key roles played by the regulation of the homologues of STOMAGEN, ER, SDD1, and FAMA in the control of this response in poplar.

  5. Oxidation and disorder in few-layered graphene induced by the electron-beam irradiation

    SciTech Connect

    Xu Zhiwei; Wang Rui; Qian Xiaoming; Chen Lei; Li Jialu; Song Xiaoyan; Liu Liangsen; Chen Guangwei

    2011-05-02

    Structural changes caused by an electron beam with the high irradiation energy of 5 MeV were investigated in few-layered graphene. Both the original and the irradiated few-layered graphene were characterized by x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy. It was found that a typical diffraction peak of graphene oxide emerged and this may be attributed to a partial oxidation in few-layered graphene which was induced by the irradiation. In addition, the graphitic structure of few-layered graphene was found to be disordered according to the increased intensity ratio of D to G band.

  6. Irradiation-induced grain growth in nanocrystalline reduced activation ferrite/martensite steel

    SciTech Connect

    Liu, W. B.; Chen, L. Q.; Zhang, C. Yang, Z. G.; Ji, Y. Z.; Zang, H.; Shen, T. L.

    2014-09-22

    In this work, we investigate the microstructure evolution of surface-nanocrystallized reduced activation ferrite/martensite steels upon high-dose helium ion irradiation (24.3 dpa). We report a significant irradiation-induced grain growth in the irradiated buried layer at a depth of 300–500 nm, rather than at the peak damage region (at a depth of ∼840 nm). This phenomenon can be explained by the thermal spike model: minimization of the grain boundary (GB) curvature resulting from atomic diffusion in the cascade center near GBs.

  7. Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo

    PubMed Central

    Brönnimann, Daniel; Bouchet, Audrey; Schneider, Christoph; Potez, Marine; Serduc, Raphaël; Bräuer-Krisch, Elke; Graber, Werner; von Gunten, Stephan; Laissue, Jean Albert; Djonov, Valentin

    2016-01-01

    Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25–100 μm wide) and minibeams (200–800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a+ thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool. PMID:27640676

  8. Increased metallothionein content in rat liver induced by x irradiation and exposure to high oxygen tension

    SciTech Connect

    Shiraishi, N.; Aono, K.; Utsumi, K.

    1983-08-01

    X irradiation and exposure to high oxygen tension are known to induce lipid peroxidation. The effects of these stresses on hepatic content of metallothionein, which may be involved in the regulation of zinc and copper metabolism, have been studied. The amount of metallothionein in rat liver was increased 11-fold by a high dose of X irradiation (1000 R). Increased metallothionein content (about 15 times) was also observed in liver of rats exposed to high oxygen tension for 3 days.

  9. Enhanced growth and experimental metastasis of chemically induced tumor in ultraviolet irradiated syngeneic mice.

    PubMed

    Gensler, H L; Chen, H

    1991-05-01

    Recent studies have shown that ultraviolet (UV) irradiation induces a systemic effect which enhances subsequent tumor induction by benzo[a]pyrene in a manner which is dependent on the dose of benzo[a]pyrene. The present study was designed to test whether UV-B irradiation renders mice susceptible to subcutaneous or intravenous injection of a regressor tumor induced by benzo[a]pyrene. The sources of UV-B irradiation were banks of 6 Westinghouse FS-40 sunlamps, situated 20 cm above the mouse cages. Female BALB/cAnNHsd received five 30-min dorsal UV-B radiation treatments per week for 12 weeks, resulting in a total dose of approx. 6.4 x 10(5) J m-2. Two to seven days after termination of UV treatments, syngeneic regressor tumor cells (BP2) induced by benzo[a]pyrene were injected subcutaneously or intravenously into irradiated mice and unirradiated controls. By 38 days post subcutaneous implantation, 24/30 and 3/30 BP2 implants were detectable in the irradiated and unirradiated mice, respectively. Ultraviolet irradiated mice were also unable to reject lung colonies resulting from intravenous administration of BP2 cells, although they were rejected by unirradiated mice. The mean number of lung colonies per mouse was 16- to 35-fold greater in UV irradiated mice than in unirradiated controls, at 14 to 17 days post injection. Thus, UV irradiation rendered mice, with no known exposure to benzo[a]pyrene, susceptible to a subcutaneous or intravenous injection of a regressor tumor induced by benzo[a]pyrene.

  10. Resistance induced by normal and irradiated Schistosoma mansoni: ability of various worm stages to serve as inducers and targets in mice

    SciTech Connect

    Dean, D.A.; Cioli, D.; Bukowski, M.A.

    1981-09-01

    Lung stage schistosomula exposed to 50 kilorads of gamma irradiation induced significant resistance to challenge infection with Schistosoma mansoni following intravenous (tail or mesenteric vein), intramuscular, or intraperitoneal injection into mice. Similar or higher levels were induced with irradiated cercariae, while irradiated 3- or 4-week-old worms induced little resistance. Non-irradiated day 6 and day 12 lung schistosomula injected into mice immunized with irradiated cercariae were susceptible to elimination, though to a lesser extent than a challenge infection administered at the cercarial stage. Day 20 liver worms injected into a mesenteric vein were not susceptible to irradiated cercaria-induced resistance. In contrast, cercariae, day 6 lung schistosomula, day 12 lung schistosomula and day 20 liver worms were all susceptible to the resistance induced by a chronic (non-irradiated) infection.

  11. Modifications in stromal extracellular matrix of aged corneas can be induced by ultraviolet A irradiation

    PubMed Central

    Gendron, Sébastien P; Rochette, Patrick J

    2015-01-01

    With age, structural and functional changes can be observed in human cornea. Some studies have shown a loss of corneal transparency and an increase in turbidity associated with aging. These changes are caused by modifications in the composition and arrangement of extracellular matrix in the corneal stroma. In human skin, it is well documented that exposure to solar radiation, and mainly to the UVA wavelengths, leads to phenotypes of photoaging characterized by alteration in extracellular matrix of the dermis. Although the cornea is also exposed to solar radiation, the extracellular matrix modifications observed in aging corneas have been mainly attributed to chronological aging and not to solar exposure. To ascertain the real implication of UVA exposure in extracellular matrix changes observed with age in human cornea, we have developed a model of photoaging by chronically exposing corneal stroma keratocytes with a precise UVA irradiation protocol. Using this model, we have analyzed UVA-induced transcriptomic and proteomic changes in corneal stroma. Our results show that cumulative UVA exposure causes changes in extracellular matrix that are found in corneal stromas of aged individuals, suggesting that solar exposure catalyzes corneal aging. Indeed, we observe a downregulation of collagen and proteoglycan gene expression and a reduction in proteoglycan production and secretion in response to cumulative UVA exposure. This study provides the first evidence that chronic ocular exposure to sunlight affects extracellular matrix composition and thus plays a role in corneal changes observed with age. PMID:25728164

  12. Radiation-Induced Topological Disorder in Irradiated Network Structures

    SciTech Connect

    Hobbs, Linn W.

    2002-12-21

    This report summarizes results of a research program investigating the fundamental principles underlying the phenomenon of topological disordering in a radiation environment. This phenomenon is known popularly as amorphization, but is more formally described as a process of radiation-induced structural arrangement that leads in crystals to loss of long-range translational and orientational correlations and in glasses to analogous alteration of connectivity topologies. The program focus has been on a set compound ceramic solids with directed bonding exhibiting structures that can be described as networks. Such solids include SiO2, Si3N4, SiC, which are of interest to applications in fusion energy production, nuclear waste storage, and device manufacture involving ion implantation or use in radiation fields. The principal investigative tools comprise a combination of experimental diffraction-based techniques, topological modeling, and molecular-dynamics simulations that have proven a rich source of information in the preceding support period. The results from the present support period fall into three task areas. The first comprises enumeration of the rigidity constraints applying to (1) more complex ceramic structures (such as rutile, corundum, spinel and olivine structures) that exhibit multiply polytopic coordination units or multiple modes of connecting such units, (2) elemental solids (such as graphite, silicon and diamond) for which a correct choice of polytope is necessary to achieve correct representation of the constraints, and (3) compounds (such as spinel and silicon carbide) that exhibit chemical disorder on one or several sublattices. With correct identification of the topological constraints, a unique correlation is shown to exist between constraint and amorphizability which demonstrates that amorphization occurs at a critical constraint loss. The second task involves the application of molecular dynamics (MD) methods to topologically-generated models

  13. Electron-irradiation-induced crystallization of amorphous orthophosphates

    SciTech Connect

    Meldrum, A.; Ewing, R.C.; Boatner, L.A.

    1996-12-01

    Amorphous LaPO{sub 4}, EuPO{sub 4}, GdPO{sub 4}, ScPO{sub 4}, and fluorapatite [Ca{sub 5}(PO{sub 4}){sub 3}F] were irradiated by electron beam in a TEM. Irradiations were done at -150 to 300 C, 80 to 200 keV, and current densities from 0.3 to 16 A/cm{sup 2}. In all cases, the materials crystallized to form a randomly oriented polycrystalline assemblage. Crystallization is driven dominantly by inelastic processes, although ballistic collisions with target nuclei can be important above 175 keV, particularly in apatite. Using a high current density, crystallization is so fast that continuous lines of crystallites can be ``drawn`` on the amorphous matrix.

  14. Cardiolipin-Specific Peroxidase Reactions of Cytochrome c in Mitochondria During Irradiation-Induced Apoptosis

    SciTech Connect

    Belikova, Natalia A.; Jiang Jianfei; Tyurina, Yulia Y.; Zhao Qing; Epperly, Michael W.; Greenberger, Joel; Kagan, Valerian E.

    2007-09-01

    Purpose: To determine whether cytochrome c (cyt c) content and associated cardiolipin oxidation can be determinants of cell sensitivity to irradiation-induced apoptosis. Methods and Materials: The small interfering RNA (siRNA) approach was used to engineer HeLa cells with lowered contents of cyt c (14%, HeLa 1.2 cells). Cells were treated by {gamma}-irradiation (in doses of 5-40 Gy). Lipid oxidation was characterized by electrospray ionization mass spectrometry analysis and fluorescence high-performance liquid chromatography-based Amplex Red assay. Release of a proapoptotic factor (cyt c, Smac/DIABLO) was detected by Western blotting. Apoptosis was revealed by caspase-3/7 activation and phosphatidylserine externalization. Results: Irradiation caused selective accumulation of hydroperoxides in cardiolipin (CL) but not in other phospholipids. HeLa 1.2 cells responded by a lower irradiation-induced accumulation of CL oxidation products than parental HeLa cells. Proportionally decreased release of a proapoptotic factor, Smac/DIABLO, was detected in cyt c-deficient cells after irradiation. Caspase-3/7 activation and phosphatidylserine externalization were proportional to the cyt c content in cells. Conclusions: Cytochrome c is an important catalyst of CL peroxidation, critical to the execution of the apoptotic program. This new role of cyt c in irradiation-induced apoptosis is essential for the development of new radioprotectors and radiosensitizers.

  15. Nonlinear broadband photoluminescence of graphene induced by femtosecond laser irradiation

    SciTech Connect

    Liu, Wei-Tao; Wu, S.W.; Schuck, P.J.; Salmeron, Miquel; Shen, Y.R.; Wang, F.

    2010-07-01

    Upon femtosecond laser irradiation, a bright, broadband photoluminescence is observed from graphene at frequencies well above the excitation frequency. Analyses show that it arises from radiative recombination of a broad distribution of nonequilibrium electrons and holes, generated by rapid scattering between photoexcited carriers within tens of femtoseconds after the optical excitation. Its highly unusual characteristics come from the unique electronic and structural properties of graphene.

  16. Protective Effect of Carvacrol on Oxidative Stress and Cellular DNA Damage Induced by UVB Irradiation in Human Peripheral Lymphocytes.

    PubMed

    Aristatile, Balakrishnan; Al-Numair, Khalid S; Al-Assaf, Abdullah H; Veeramani, Chinnadurai; Pugalendi, Kodukkur Viswanathan

    2015-11-01

    Exposure to ultraviolet B (UVB; 280-320 nm) radiation induces the formation of reactive oxygen species (ROS) in the biological system. In this study, we examined the protective effect of carvacrol on UVB-induced lipid peroxidation and oxidative DNA damage with reference to alterations in cellular an-tioxidant status in human lymphocytes. A series of in vitro assays (hydroxyl radical, superoxide, nitric oxide, DPPH (2,2-Diphenyl-1-picryl hydrazyl), and ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assays) demonstrate antioxidant property of carvacrol in our study. UVB exposure significantly increased thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LHPs), % tail DNA and tail moment; decreased % cell viability and antioxidant status in UVB-irradiated lymphocytes. Treatment with carvacrol 30 min prior to UVB-exposure resulted in a significant decline of TBARS, LHP, % tail DNA, and tail moment and increased % cell viability as carvacrol concentration increased. UVB irradiated lymphocytes with carvacrol alone (at 10 μg/mL) gave no significant change in cell viability, TBARS, LHP, % tail DNA, and tail moment when compared with normal lymphocytes. On the basis of our results, we conclude that carvacrol, a dietary antioxidant, mediates its protective effect through modulation of UVB-induced ROS.

  17. Cranial irradiation induces bone marrow-derived microglia in adult mouse brain tissue.

    PubMed

    Okonogi, Noriyuki; Nakamura, Kazuhiro; Suzuki, Yoshiyuki; Suto, Nana; Suzue, Kazutomo; Kaminuma, Takuya; Nakano, Takashi; Hirai, Hirokazu

    2014-07-01

    Postnatal hematopoietic progenitor cells do not contribute to microglial homeostasis in adult mice under normal conditions. However, previous studies using whole-body irradiation and bone marrow (BM) transplantation models have shown that adult BM cells migrate into the brain tissue and differentiate into microglia (BM-derived microglia; BMDM). Here, we investigated whether cranial irradiation alone was sufficient to induce the generation of BMDM in the adult mouse brain. Transgenic mice that express green fluorescent protein (GFP) under the control of a murine stem cell virus (MSCV) promoter (MSCV-GFP mice) were used. MSCV-GFP mice express GFP in BM cells but not in the resident microglia in the brain. Therefore, these mice allowed us to detect BM-derived cells in the brain without BM reconstitution. MSCV-GFP mice, aged 8-12 weeks, received 13.0 Gy irradiation only to the cranium, and BM-derived cells in the brain were quantified at 3 and 8 weeks after irradiation. No BM-derived cells were detected in control non-irradiated MSCV-GFP mouse brains, but numerous GFP-labeled BM-derived cells were present in the brain stem, basal ganglia and cerebral cortex of the irradiated MSCV-GFP mice. These BM-derived cells were positive for Iba1, a marker for microglia, indicating that GFP-positive BM-derived cells were microglial in nature. The population of BMDM was significantly greater at 8 weeks post-irradiation than at 3 weeks post-irradiation in all brain regions examined. Our results clearly show that cranial irradiation alone is sufficient to induce the generation of BMDM in the adult mouse.

  18. Radiation-induced apoptosis in SCID mice spleen after low dose irradiation

    NASA Astrophysics Data System (ADS)

    Takahashi, A.; Kondo, N.; Inaba, H.; Uotani, K.; Kiyohara, Y.; Ohnishi, K.; Ohnishi, T.

    To assess the radioadaptive response of the whole body system in mice, we examined the temporal effect of low dose priming as an indicator of challenging irradiation-induced apoptosis through a p53 tumor suppressor protein- mediated signal transduction pathway. The p53 protein also plays an important role both in cell cycle control and DNA repair through cellular signal transduction. Using severe combined immunodeficiency mice defective in DNA-dependent protein kinase catalytic subunit, we examined the role of DNA-dependent protein kinase activity in radioadaptation induced by low dose irradiation. Specific pathogen free 5-week-old female severe combined immunodeficiency mice and the parental mice (CB-17 Icr +/ + were irradiated with X-ray at 3.0 C3y at 1, 2, 3 or 4 weeks after the conditioning irradiation at 0.15, 0.30, 0.45 or 0.60 Gy. The mice spleens were fixed for immunohistochemistry 12 h after the challenging irradiation. The p53-dependent apoptosis related Bax proteins on formalin-fixed paraffin-embedded sections were stained by the avidin-biotin peroxidase complex method The apoptosis incidence in the sections was measured by hematoxylin-eosin staining. The frequency of Bax- and apoptosis-positive cells increased up to 12 h after the challenging irradiation in the spleen of both mice. However, these cells were not observed after a low dose irradiation at 0.15-0.60 Gy When pre-irradiation at 0.45 Gy 2 weeks before the challenging irradiation at 3.0 Gy was performed, Bax accumulation and apoptosis induced by challenging irradiation were depressed in the spleens of CB-17 Icr +/ + mice, but not in severe combined immunodeficiency mice. These data suggest that DNA-dependent protein kinase might play a major role in radioadaptation induced by pre-irradiation with a low dose in mice spleen. We expect that the present findings will provide useful information in the health care of space crews.

  19. Hydrological Alterations Due to Climate-Induced Regional Vegetation Change

    NASA Astrophysics Data System (ADS)

    White, A. B.; Vivoni, E. R.; Springer, E. P.

    2010-12-01

    An extended, severe drought in the southwestern U.S. from 2000 to 2003 was accompanied by increased temperatures and bark beetle infestations, inducing the large-scale mortality of woody overstory (Pinus edulis). The consequential redistribution of water, radiation, and nutrient availability modified the ecosystem phenology, species composition, and forced the ecosystem to transition into a new state. We hypothesize that the hydrological processes in the ecosystem were also altered due to the mortality. Thus, our objective is to investigate changes in the soil-vegetation-atmosphere continuum at the watershed scale. The Rio Ojo Caliente Basin is a subbasin of the Upper Rio Grande, located mostly in New Mexico, and is approximately 1,000 km2. Examining a remotely-sensed vegetation index (1-km AVHRR NDVI from 1990 to 2006), there is an increasing trend in the NDVI from 1989 to 1999 (pre-mortality period), a decreasing trend from 2000 to 2003 (mortality period), and a dramatic increasing trend from 2004 to 2006 (post-mortality period) in which the NDVI rebounds to nearly pre-mortality magnitudes. This pattern exists across varying spatial scales (plot to watershed to region) and signifies a profound alteration in the ecosystem, for while the vegetation composition was altered to a great degree, the system rapidly returned to a homeostatic state balancing resource supply and use during the post-mortality period. To investigate hydrological changes due to the mortality, we employ a physically-based, distributed hydrologic model, tRIBS (TIN-based Real-Time Integrated Basin Simulator) for the Rio Ojo Caliente Basin. STATSGO 1-km soils data, 10-meter National Elevation Dataset DEMs, Carson National Forest vegetation species data, and MM5-downscaled NCEP/NCAR Reanalysis-I meteorologic data are used as model inputs. A combination of MODIS and AVHRR remote-sensing data, values from the literature, and field data from a long-term, pi {n}on-juniper (PJ) observation site in Los

  20. Apoptosis and morphological alterations after UVA irradiation in red blood cells of p53 deficient Japanese medaka (Oryzias latipes).

    PubMed

    Sayed, Alla El-Din Hamid; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi

    2016-08-01

    Morphological alterations in red blood cells were described as hematological bioindicators of UVA exposure to investigate the sensitivity to UVA in wild type Japanese medaka (Oryzias latipes) and a p53 deficient mutant. The fewer abnormal red blood cells were observed in the p53 mutant fish under the control conditions. After exposure to different doses of UVA radiation (15min, 30min and 60min/day for 3days), cellular and nuclear alterations in red blood cells were analyzed in the UVA exposed fish compared with non-exposed controls and those alterations included acanthocytes, cell membrane lysis, swollen cells, teardrop-like cell, hemolyzed cells and sickle cells. Those alterations were increased after the UVA exposure both in wild type and the p53 deficient fish. Moreover, apoptosis analyzed by acridine orange assay showed increased number of apoptosis in red blood cells at the higher UVA exposure dose. No micronuclei but nuclear abnormalities as eccentric nucleus, nuclear budding, deformed nucleus, and bilobed nucleus were observed in each group. These results suggested that UVA exposure induced both p53 dependent and independent apoptosis and morphological alterations in red blood cells but less sensitive to UVA than Wild type in medaka fish.

  1. Oxidative damage of DNA induced by X-irradiation decreases the uterine endometrial receptivity which involves mitochondrial and lysosomal dysfunction

    PubMed Central

    Gao, Wei; Liang, Jin-Xiao; Liu, Shuai; Liu, Chang; Liu, Xiao-Fang; Wang, Xiao-Qi; Yan, Qiu

    2015-01-01

    X irradiation may lead to female infertility and the mechanism is still not clear. After X irradiation exposure, significantly morphological changes and functional decline in endometrial epithelial cells were observed. The mitochondrial and lysosomal dysfunction and oxidative DNA damage were noticed after X irradiation. In addition, pretreatment with NAC, NH4Cl or Pep A reduced the X irradiation induced damages. These studies demonstrate that the oxidative DNA damage which involved dysfunctional lysosomal and mitochondrial contribute to X irradiation-induced impaired receptive state of uterine endometrium and proper protective reagents can be helpful in improving endometrial function. PMID:26064230

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

    PubMed

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

    2017-02-01

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

  3. [X-ray irradiation induces apoptosis of mouse GC1 sperm cells via nuclear translocation of apoptosis-inducing factor].

    PubMed

    Yang, Huiying; Ding, Jingbin; Wang, Zhijun; Ding, Juan; Xia, Xinshe; Zhao, Wei

    2017-03-01

    Objective To study the effect of X-ray irradiation on the localization of apoptosis inducing factor (AIF) in mouse GC1 sperm cells. Methods After GC1 cells were treated with 0, 3, 6 and 9 Gy X irradiation, BrdU incorporation assay was performed to detect the proliferation of GC1 cells. Forty-eight hours after irradiation, the nuclear condensation was observed by DAPI staining. The subcellular localization of AIF was showed using the immunofluorescence staining, both in the whole cell extracts and in nuclear extracts, and the expression levels of AIF were detected using Western blot analysis. Results With the increase of X-ray irradiation dose, the proliferation of GC1 cells significantly decreased, and the activity of cells was weakened. After 6 Gy irradiation, in nuclear extracts, but not in the whole cell extracts, the protein AIF was upregulated significantly. It meant the nuclear translocation of protein AIF. Conclusion X-ray irradiation induces the apoptosis of mouse GC1 sperm cells, meanwhile, the nuclear translocation of AIF occurs.

  4. Transcranial low-level infrared laser irradiation ameliorates depression induced by reserpine in rats.

    PubMed

    Mohammed, Haitham S

    2016-11-01

    Transcranial low-level infrared laser is a modality of therapy based on the principle of photons delivered in a non-invasive manner through the skull for the treatment of some neurological conditions such as psychological disorders, traumatic brain injuries, and neurodegenerative diseases among others. In the present study, effects of low-level infrared laser irradiation with different radiation powers (80, 200, and 400 mW, continuous wave) were investigated on normal animals subjected to forced swimming test (FST). Results indicated that there are changes in FST parameters in animals irradiated with laser; the lowest dose provoked a significant increase in animal activity (swimming and climbing) and a significant decrease in animal's immobility, while the highest laser dose resulted in a complete inverse action by significantly increasing animal immobility and significantly decreasing animal activity with respect to control animals. The lowest dose (80 mW) of transcranial laser irradiation has then utilized on animals injected with a chronic dose of reserpine (0.2 mg/kg i.p. for 14 days) served as an animal model of depression. Laser irradiation has successfully ameliorated depression induced by reserpine as indicated by FST parameters and electrocorticography (ECoG) spectral analysis in irradiated animals. The findings of the present study emphasized the beneficial effects of low-level infrared laser irradiation on normal and healthy animals. Additionally, it indicated the potential antidepressant activity of the low dose of infrared laser irradiation.

  5. Increased EZH2 and decreased osteoblastogenesis during local irradiation-induced bone loss in rats

    PubMed Central

    Guo, Changjun; Li, Changwei; Yang, Kai; Kang, Hui; Xu, Xiaoya; Xu, Xiangyang; Deng, Lianfu

    2016-01-01

    Radiation therapy is commonly used to treat cancer patients but exhibits adverse effects, including insufficiency fractures and bone loss. Epigenetic regulation plays an important role in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Here, we reported local bone changes after single-dose exposure to 137CS irradiation in rats. Femur bone mineral density (BMD) and trabecular bone volume in the tibia were significantly decreased at 12 weeks after irradiation. Micro-CT results showed that tBMD, Tb.h and Tb.N were also significantly reduced at 12 weeks after irradiation exposure. ALP-positive OB.S/BS was decreased by 42.3% at 2 weeks after irradiation and was decreased by 50.8% at 12 weeks after exposure. In contrast to the decreased expression of Runx2 and BMP2, we found EZH2 expression was significantly increased at 2 weeks after single-dose 137CS irradiation in BMSCs. Together, our results demonstrated that single-dose 137CS irradiation induces BMD loss and the deterioration of bone microarchitecture in the rat skeleton. Furthermore, EZH2 expression increased and osteoblastogenesis decreased after irradiation. The underlying mechanisms warrant further investigation. PMID:27499068

  6. Schisandrin B protects against solar irradiation-induced oxidative stress in rat skin tissue.

    PubMed

    Lam, Philip Y; Yan, Chung Wai; Chiu, Po Yee; Leung, Hoi Yan; Ko, Kam Ming

    2011-04-01

    Schisandrin B (Sch B) and schisandrin C (Sch C), but not schisandrin A and dimethyl diphenyl bicarboxylate, protected rat skin tissue against solar irradiation-induced oxidative injury, as evidenced by a reversal of solar irradiation-induced changes in cellular reduced glutathione and α-tocopherol levels, as well as antioxidant enzyme activities and malondialdehyde production. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production in rat skin microsomes. Taken together, Sch B or Sch C, by virtue of its pro-oxidant action and the subsequent eliciting of a glutathione antioxidant response, may prevent photo-aging of skin.

  7. Detection of radiation-induced hydrocarbons in baked sponged cake prepared with irradiated liquid egg

    NASA Astrophysics Data System (ADS)

    Schulzki, G.; Spiegelberg, A.; Bögl, K. W.; Schreiber, G. A.

    1995-02-01

    For identification of irradiated food, radiation-induced volatile hydrocarbons (HC) are determined by gas chromatography in the non-polar fraction of fat. However, in complex food matrices the detection is often disturbed by fat-associated compounds. On-line coupling of high performance liquid chromatography (LC) and gas chromatography (GC) is very efficient to remove such compounds from the HC fraction. The high sensitivity of this fast and efficient technique is demonstrated by the example of detection of radiation-induced HC in fat isolated from baked sponge cake which had been prepared with irradiated liquid egg.

  8. Modelling irradiation-induced softening in BCC iron by crystal plasticity approach

    NASA Astrophysics Data System (ADS)

    Xiao, Xiazi; Terentyev, Dmitry; Yu, Long; Song, Dingkun; Bakaev, A.; Duan, Huiling

    2015-11-01

    Crystal plasticity model (CPM) for BCC iron to account for radiation-induced strain softening is proposed. CPM is based on the plastically-driven and thermally-activated removal of dislocation loops. Atomistic simulations are applied to parameterize dislocation-defect interactions. Combining experimental microstructures, defect-hardening/absorption rules from atomistic simulations, and CPM fitted to properties of non-irradiated iron, the model achieves a good agreement with experimental data regarding radiation-induced strain softening and flow stress increase under neutron irradiation.

  9. [High-dose radiation-induced meningioma following prophylactic cranial irradiation for acute lymphoblastic leukaemia].

    PubMed

    Matsuda, Ryosuke; Nikaido, Yuji; Yamada, Tomonori; Mishima, Hideaki; Tamaki, Ryo

    2005-03-01

    A 12 year-old girl was treated with prophylatic cranial irradiation for acute lymphoblastic leukaemia (ALL). At the age of 39, she was admitted to our hospital for status epilepticus. Computed tomography demonstrated two, enhancing bilateral sided intracranial tumors. After surgery, this patient presented meningiomas which histologically, were of the meningothelial type. The high cure rate in childhood ALL, attributable to aggressive chemotherapy and prophylatic cranial irradiation, is capable of inducing secondary brain tumor. Twelve cases of high-dose radiation-induced meningioma following ALL are also reviewed.

  10. Blue light irradiation-induced oxidative stress in vivo via ROS generation in rat gingival tissue.

    PubMed

    Yoshida, Ayaka; Shiotsu-Ogura, Yukako; Wada-Takahashi, Satoko; Takahashi, Shun-suke; Toyama, Toshizo; Yoshino, Fumihiko

    2015-10-01

    It has been reported that oxidative stress with reactive oxygen species (ROS) generation is induced by blue light irradiation to a living body. Only limited research has been reported in dental field on the dangers of blue light, mostly focusing on cytotoxicity associated with heat injury of dental pulp. We thus performed an in vivo study on oral tissue exposed to blue light. ROS generated upon blue light irradiation of flavin adenine dinucleotide were measured by electron spin resonance spectroscopy. After blue light irradiation, the palatal gingiva of Wistar rats were isolated. Collected samples were subjected to biochemical analysis of lipid peroxidation and glutathione. Singlet oxygen was generated by blue light irradiation, but was significantly quenched in an N-acetyl-L-cysteine (NAC) concentration-dependent manner. Blue light significantly accelerated oxidative stress and increased the oxidized glutathione levels in gingival tissue. These effects were also inhibited by NAC pre-administration. The results suggest that blue light irradiation at clinical levels of tooth bleaching treatment may enhance lipid peroxidation by the induction of oxidative stress and the consumption of a significant amount of intracellular glutathione. In addition, NAC might be an effective supplement for the protection of oral tissues against blue light irradiation-induced oxidative damage.

  11. Proton Irradiation Alters Expression of FGF-2 In Human Lens Epithelial Cells

    NASA Technical Reports Server (NTRS)

    Blakely, E. A.; Bjornstad, K. A.; Chang, P. Y.; McNamara, M. P.; Chang, E.

    1999-01-01

    We are investigating a role for proton radiation-induced changes in FGF-2 gene expression as part of the mechanism(s) underlying lens cell injury. Radiation injury to the human lens is associated with the induction of cataract following exposure to protons.

  12. Ion irradiation-induced diffusion in bixbyite-fluorite related oxides: Dislocations and phase transformation

    NASA Astrophysics Data System (ADS)

    Rolly, Gaboriaud; Fabien, Paumier; Bertrand, Lacroix

    2014-05-01

    Ion-irradiation induced diffusion and the phase transformation of a bixbyite-fluorite related rare earth oxide thin films are studied. This work is focused on yttrium sesquioxide, Y2O3, thin films deposited on Si (1 0 0) substrates using the ion beam sputtering technique (IBS). As-deposited samples were annealed ant then irradiated at cryogenic temperature (80 K) with 260 keV Xe2+ at different fluences. The irradiated thin oxide films are characterized by X-ray diffraction. A cubic to monoclinic phase transformation was observed. Analysis of this phenomenon is done in terms of residual stresses. Stress measurements as a function of irradiation fluences were realised using the XRD-sin2ψ method. Stress evolution and kinetic of the phase transformation are compared and leads to the role-played by the nucleation of point and extended defects.

  13. He+ irradiation induced cracking and exfoliating on the surface of Ti3AlC2

    NASA Astrophysics Data System (ADS)

    Shen, H. H.; Ao, L.; Li, F. Z.; Peng, S. M.; Zhang, H. B.; Sun, K.; Zu, X. T.

    2017-03-01

    We report a systematic study of the effects of a 400 keV helium ion beam irradiation on the surface morphology and crystal structure of Ti3AlC2 by combined scanning electron microscopy, grazing incidence X-ray diffraction and transmission electron microscopy. Helium irradiation experiments were performed at both room temperature and 500 °C, respectively, with fluence up to 2.0 × 1017 He+/cm2. After irradiation, intragranular orientated cracks grew along the (10 1 bar 0)Ti3AlC2 plane and the surface has started to exfoliate. The formation of the cracks is mainly attributed to the reduction of the lattice parameter along the a direction induced by ion irradiation, and the crack growth is affected by the grain size and the content of impurity phase TiAl3. The surface exfoliation is due to the blistering of He bubbles at the projected depth.

  14. A revised description of graphite irradiation induced creep

    NASA Astrophysics Data System (ADS)

    Davies, Mark A.; Bradford, Mark

    2008-10-01

    The UK fleet of advanced gas-cooled reactors (AGR) have been operating for a substantial period of time and rely on data obtained from material test reactor (MTR) programs, dating back to the 1960s and through to the end of the 1980s, to support current and future operation. Historically an empirical approach to the irradiation behaviour of graphite has been used and, due to the nature of the available MTR data and the lack of a consistent set of data containing all the relevant measurements, this is still largely the case at present. Differences in interpretation of the available MTR data can have a significant impact on the assessed integrity of core components. Consequently, a thorough review of the basis of the current models is being carried out, and new models are being developed as necessary. This paper presents some new interpretations of the available low fluence MTR data for irradiation creep and application of a revised model to some high fluence MTR data.

  15. Classification System for Identifying Women at Risk for Altered Partial Breast Irradiation Recommendations After Breast Magnetic Resonance Imaging

    SciTech Connect

    Kowalchik, Kristin V.; Vallow, Laura A.; McDonough, Michelle; Thomas, Colleen S.; Heckman, Michael G.; Peterson, Jennifer L.; Adkisson, Cameron D.; Serago, Christopher; McLaughlin, Sarah A.

    2013-09-01

    Purpose: To study the utility of preoperative breast MRI for partial breast irradiation (PBI) patient selection, using multivariable analysis of significant risk factors to create a classification rule. Methods and Materials: Between 2002 and 2009, 712 women with newly diagnosed breast cancer underwent preoperative bilateral breast MRI at Mayo Clinic Florida. Of this cohort, 566 were retrospectively deemed eligible for PBI according to the National Surgical Adjuvant Breast and Bowel Project Protocol B-39 inclusion criteria using physical examination, mammogram, and/or ultrasound. Magnetic resonance images were then reviewed to determine their impact on patient eligibility. The patient and tumor characteristics were evaluated to determine risk factors for altered PBI eligibility after MRI and to create a classification rule. Results: Of the 566 patients initially eligible for PBI, 141 (25%) were found ineligible because of pathologically proven MRI findings. Magnetic resonance imaging detected additional ipsilateral breast cancer in 118 (21%). Of these, 62 (11%) had more extensive disease than originally noted before MRI, and 64 (11%) had multicentric disease. Contralateral breast cancer was detected in 28 (5%). Four characteristics were found to be significantly associated with PBI ineligibility after MRI on multivariable analysis: premenopausal status (P=.021), detection by palpation (P<.001), first-degree relative with a history of breast cancer (P=.033), and lobular histology (P=.002). Risk factors were assigned a score of 0-2. The risk of altered PBI eligibility from MRI based on number of risk factors was 0:18%; 1:22%; 2:42%; 3:65%. Conclusions: Preoperative bilateral breast MRI altered the PBI recommendations for 25% of women. Women who may undergo PBI should be considered for breast MRI, especially those with lobular histology or with 2 or more of the following risk factors: premenopausal, detection by palpation, and first-degree relative with a history of

  16. Altered Affinity Maturation in Primary Response to (4-hydroxy-3-nitrophenyl) Acetyl (NP) after Autologous Reconstitution of Irradiated C57BL/6 Mice

    PubMed Central

    De Trez, Carl; Van Acker, Annette; Vansanten, Georgette; Urbain, Jacques; Brait, Maryse

    2002-01-01

    Immune responses developing in irradiated environment are profoundly altered. The memory anti-arsonate response of A/J mice is dominated by a major clonotype encoded by a single gene segment combination called CRIA. In irradiated and autoreconstituted A/J mice, the level of anti-ARS antibodies upon secondary immunization is normal but devoid of CRIA antibodies. The affinity maturation process and the somatic mutation frequency are reduced. Isotype switching and development of germinal centers (GC) are delayed. The primary antibody response of C57BL/6 mice to the hapten (4-hydroxy-3-nitrophenyl) acetyl (NP)-Keyhole Limpet Hemocyanin (KLH) is dominated by antibodies encoded by a family of closely related VH genes associated with the expression of the λ1 light chain.We investigated the anti-NP primary response in irradiated and autoreconstituted C57BL/6 mice. We observed some splenic alterations as previously described in the irradiated A/J model. Germinal center reaction is delayed although the extrafollicular foci appearance is unchanged. Irradiated C57BL/6 mice are able to mount a primary anti-NP response dominated by λ1 positive antibodies but fail to produce high affinity NP-binding IgGl antibodies. Following a second antigenic challenge, irradiated mice develop enlarged GC and foci. Furthermore, higher affinity NP-binding IgG1 antibodies are detected. PMID:12885152

  17. Radiation-induced bystander effect in non-irradiated glioblastoma spheroid cells.

    PubMed

    Faqihi, Fahime; Neshastehriz, Ali; Soleymanifard, Shokouhozaman; Shabani, Robabeh; Eivazzadeh, Nazila

    2015-09-01

    Radiation-induced bystander effects (RIBEs) are detected in cells that are not irradiated but receive signals from treated cells. The present study explored these bystander effects in a U87MG multicellular tumour spheroid model. A medium transfer technique was employed to induce the bystander effect, and colony formation assay was used to evaluate the effect. Relative changes in expression of BAX, BCL2, JNK and ERK genes were analysed using RT-PCR to investigate the RIBE mechanism. A significant decrease in plating efficiency was observed for both bystander and irradiated cells. The survival fraction was calculated for bystander cells to be 69.48% and for irradiated cells to be 34.68%. There was no change in pro-apoptotic BAX relative expression, but anti-apoptotic BCL2 showed downregulation in both irradiated and bystander cells. Pro-apoptotic JNK in bystander samples and ERK in irradiated samples were upregulated. The clonogenic survival data suggests that there was a classic RIBE in U87MG spheroids exposed to 4 Gy of X-rays, using a medium transfer technique. Changes in the expression of pro- and anti-apoptotic genes indicate involvement of both intrinsic apoptotic and MAPK pathways in inducing these effects.

  18. Naringenin Inhibits UVB Irradiation-Induced Inflammation and Oxidative Stress in the Skin of Hairless Mice.

    PubMed

    Martinez, Renata M; Pinho-Ribeiro, Felipe A; Steffen, Vinicius S; Caviglione, Carla V; Vignoli, Josiane A; Barbosa, Décio S; Baracat, Marcela M; Georgetti, Sandra R; Verri, Waldiceu A; Casagrande, Rubia

    2015-07-24

    Ultraviolet B (UVB) irradiation may cause inflammation- and oxidative-stress-dependent skin cancer and premature aging. Naringenin (1) has been reported to have anti-inflammatory and antioxidant properties, but its effects and mechanisms on UVB irradiation-induced inflammation and oxidative stress are still not known. Thus, the present study aimed to investigate the potential of naringenin to mitigate UVB irradiation-induced inflammation and oxidative damage in the skin of hairless mice. Skin edema, myeloperoxidase (neutrophil marker) and matrix metalloproteinase-9 (MMP-9) activity, and cytokine production were measured after UVB irradiation. Oxidative stress was evaluated by 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) scavenging ability, ferric reducing antioxidant power (FRAP), reduced glutathione levels, catalase activity, lipid peroxidation products, superoxide anion production, and gp91phox (NADPH oxidase subunit) mRNA expression by quantitative PCR. The intraperitoneal treatment with naringenin reduced skin inflammation by inhibiting skin edema, neutrophil recruitment, MMP-9 activity, and pro-inflammatory (TNF-α, IFN-γ, IL-1β, IL-4, IL-5, IL-6, IL-12, IL-13, IL-17, IL-22, and IL-23) and anti-inflammatory (TGF-β and IL-10) cytokines. Naringenin also inhibited oxidative stress by reducing superoxide anion production and the mRNA expression of gp91phox. Therefore, naringenin inhibits UVB irradiation-induced skin damage and may be a promising therapeutic approach to control skin disease.

  19. A Mouse Ear Model for Bystander Studies Induced by Microbeam Irradiation

    PubMed Central

    Buonanno, M.; Randers-Pehrson, G.; Smilenov, L. B.; Kleiman, N. J.; Young, E.; Ponnayia, B.; Brenner, D. J.

    2015-01-01

    Radiation-induced bystander effects have been observed in vitro and in cell and tissue culture models, however, there are few reported studies showing these effects in vivo. To our knowledge, this is the first reported study on bystander effects induced by microbeam irradiation in an intact living mammal. The mouse ear was used to investigate radiation-induced bystander effects in keratinocytes, utilizing a 3 MeV proton microbeam (LET 13.1 keV/µm) with a range in skin of about 135 µm. Using a custom-designed holder, the ear of an anesthetized C57BL/6J mouse was flattened by gentle suction and placed over the microbeam port to irradiate cells along a 35 µm wide, 6 mm long path. Immunohistochemical analysis of γ-H2AX foci formation in tissue sections revealed, compared to control tissue, proton-induced γ-H2AX foci formation in one of the two epidermal layers of the mouse ear. Strikingly, a higher number of cells than expected showed foci from direct irradiation effects. Although the proton-irradiated line was ~35 µm wide, the average width spanned by γ-H2AX-positive cells exceeded 150 µm. Cells adjacent to or in the epidermal layer opposite the γ-H2AX-positive region did not exhibit foci. These findings validate this mammalian model as a viable system for investigating radiation-induced bystander effects in an intact living organism. PMID:26207682

  20. Lipopolysaccharide-induced inflammation aggravates irradiation-induced injury to the young mouse brain.

    PubMed

    Roughton, Karolina; Andreasson, Ulf; Blomgren, Klas; Kalm, Marie

    2013-01-01

    Radiotherapy is an effective treatment strategy in the treatment of brain tumors, but it is also a major cause of long-term complications, especially in survivors of pediatric brain tumors. Cognitive decline caused by cranial radiotherapy is thought, at least partly, to depend on injury to stem and progenitor cells in the dentate gyrus of the hippocampus. This study investigated the effects of lipopolysaccharide (LPS)-induced inflammation at the time of irradiation (IR) in the growing mouse brain. A single injection of LPS (0.3 mg/kg) was administered 24 h prior to cranial IR of 14-day-old male mice. LPS pretreatment increased the levels of the chemokine CCL2 and the cytokine IL-1β in the brain by 440 and 560%, respectively, compared to IR alone. IR disrupted hippocampal neurogenesis and the growth of the dentate gyrus, and the mice pretreated with LPS displayed an even more pronounced lack of growth than the vehicle-treated group 2 months after IR. The density of microglia was not affected, but LPS-pretreated mice displayed 48% fewer bromodeoxyuridine-positive cells and 43% fewer doublecortin-positive cells in the granule cell layer 2 months after IR compared with the vehicle-treated group. In conclusion, an ongoing inflammation in the brain at the time of IR further enhanced the IR-induced loss of neurogenesis, and may aggravate future cognitive deficits in patients treated with cranial radiotherapy.

  1. Chronic low-dose γ-irradiation of Drosophila melanogaster larvae induces gene expression changes and enhances locomotive behavior

    PubMed Central

    Kim, Cha Soon; Seong, Ki Moon; Lee, Byung Sub; Lee, In Kyung; Yang, Kwang Hee; Kim, Ji-Young; Nam, Seon Young

    2015-01-01

    Although radiation effects have been extensively studied, the biological effects of low-dose radiation (LDR) are controversial. This study investigates LDR-induced alterations in locomotive behavior and gene expression profiles of Drosophila melanogaster. We measured locomotive behavior using larval pupation height and the rapid iterative negative geotaxis (RING) assay after exposure to 0.1 Gy γ-radiation (dose rate of 16.7 mGy/h). We also observed chronic LDR effects on development (pupation and eclosion rates) and longevity (life span). To identify chronic LDR effects on gene expression, we performed whole-genome expression analysis using gene-expression microarrays, and confirmed the results using quantitative real-time PCR. The pupation height of the LDR-treated group at the first larval instar was significantly higher (∼2-fold increase in PHI value, P < 0.05). The locomotive behavior of LDR-treated male flies (∼3 − 5 weeks of age) was significantly increased by 7.7%, 29% and 138%, respectively (P < 0.01), but pupation and eclosion rates and life spans were not significantly altered. Genome-wide expression analysis identified 344 genes that were differentially expressed in irradiated larvae compared with in control larvae. We identified several genes belonging to larval behavior functional groups such as locomotion (1.1%), oxidation reduction (8.0%), and genes involved in conventional functional groups modulated by irradiation such as defense response (4.9%), and sensory and perception (2.5%). Four candidate genes were confirmed as differentially expressed genes in irradiated larvae using qRT-PCR (>2-fold change). These data suggest that LDR stimulates locomotion-related genes, and these genes can be used as potential markers for LDR. PMID:25792464

  2. Irradiation-induced embrittlement of a 2.25Cr1Mo steel

    NASA Astrophysics Data System (ADS)

    Song, S.-H.; Faulkner, R. G.; Flewitt, P. E. J.; Smith, R. F.; Marmy, P.; Victoria, M.

    2000-07-01

    Irradiation-induced embrittlement of a 2.25Cr1Mo is investigated by means of small punch testing and scanning electron microscopy (SEM). The ductile-brittle transition temperature (DBTT) determined by the small punch test is much lower than that determined by the standard Charpy test. There are some irradiation-induced embrittlement effects after the steel is irradiated at about 270°C for 46 days with a neutron dose rate of 1.05×10 -8 dpa s -1 and at about 400°C for 86 days with a neutron dose rate of 1.75×10 -8 dpa s -1. In addition, there is some temper embrittlement after the steel is aged at about 400°C for 86 days.

  3. Schisandrin B protects against solar irradiation-induced oxidative injury in BJ human fibroblasts.

    PubMed

    Chiu, Po Yee; Lam, Philip Y; Yan, Chung Wai; Ko, Kam Ming

    2011-06-01

    The effects of schisandrin B (Sch B) and its analogs on solar irradiation-induced oxidative injury were examined in BJ human fibroblasts. Sch B and schisandrin C (Sch C) increased cellular reduced glutathione (GSH) level and protected against solar irradiation-induced oxidative injury. The photoprotection was paralleled by decreases in the elastases-type protease activity and matrix-metalloproteinases-1 expression in solar-irradiated fibroblasts. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production. The results suggest that by virtue of its pro-oxidant action and the subsequent glutathione antioxidant response, Sch B or Sch C may offer the prospect of preventing skin photo-aging.

  4. Protective effects of shikonin on brain injury induced by carbon ion beam irradiation in mice.

    PubMed

    Gan, Lu; Wang, Zhen Hua; Zhang, Hong; Zhou, Rong; Sun, Chao; Liu, Yang; Si, Jing; Liu, Yuan Yuan; Wang, Zhen Guo

    2015-02-01

    Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group (P<0.01), while obviously reduced the MDA and PCO contents and the ROS levels derived from of the brain mitochondria. The shikonin also noticeably improved the spatial memory deficits caused by carbon ion beam irradiation. All results demonstrated that shikonin could improve the irradiated brain injury which might resulted from its modulation effects on the oxidative stress induced by the 12C6+ ion beam.

  5. The effect of full/partial UV-irradiation of TiO2 films on altering the behavior of fibrinogen and platelets.

    PubMed

    Chen, Jiang; Zhao, Ansha; Chen, Huiqing; Liao, Yuzhen; Yang, Ping; Sun, Hong; Huang, Nan

    2014-10-01

    Titanium oxide (TiO2) thin film is a potential candidate for the surface modification of blood-contacting devices. It has previously been reported that ultraviolet light (UV) irradiation could alter the biocompatibility of TiO2 films. However, the effect of UV-irradiated TiO2 films on blood compatibility has rarely been reported. This study attempts to determine: (1) whether UV-irradiation of TiO2 films enhances their blood compatibility, (2) the interaction between UV-irradiated TiO2 films, fibrinogen (Fgn), and platelets, especially how Fgn and platelets respond to the geometry of the partially UV-irradiated TiO2 film surface. Anatase TiO2 films were subjected to full and partial UV-irradiation. Full UV-irradiation improved the blood compatibility of TiO2 films by almost completely inhibiting the adhesion and activation of platelets, strongly suppressing the adsorption and conformational change of Fgn, and preventing the formation of fibrin fibers. Additionally, hemolysis was not observed. After partial UV-irradiation, the regions where Fgn adsorption was reduced (Fgn-dark regions) were formed at regions where UV-irradiation had occurred, but were extended in comparison with the UV-irradiated regions, which could be related to the generation and diffusion of reactive oxygen species (ROS) on the UV-irradiated TiO2 surface. It is worthwhile to study how ROS altered the nature of TiO2 films, thereby enhancing their blood compatibility. Furthermore, platelets were found adhering to the Fgn-adsorbed regions (Fgn-bright regions) selectively, suggesting that the inhibition of platelet adhesion could be related to the suppression of Fgn adsorption on the UV-irradiated TiO2 surface. It was also noted that platelet surface coverage (Sp) was not linearly correlated with Fgn-bright region surface coverage (Sf), which indicated that the adhesion and spreading of platelets were regulated by both Sf and the geometry of Fgn.

  6. Below-ambient levels of UV induce chloroplast structural change and alter starch metabolism.

    PubMed

    Fagerberg, W R

    2007-01-01

    Electromagnetic radiation (EMR) in the 400-700 nm bandwidth of photosynthetically active radiation (PAR) has been established as an important source of energy for photosynthesis and environmental signals regulating many aspects of green-plant life. Above-ambient levels of UV-B radiation (290-320 nm) under high-PAR conditions have been shown to elicit responses in chloroplasts of Brassica napus similar to those of chloroplasts at low-PAR exposure (W. Fagerberg and J. Bornman, Physiol. Plant. 101: 833-844, 1997). The question arises as to whether UV at normal levels can also evoke similar responses. Here we provide evidence that even below-ambient levels of UV-B (1/28 ambient; Durham, N.H., U.S.A., 1200 hours, March) were capable of inducing an increase in thylakoid surface area relative to the chloroplast volume typical of a low-PAR response (shade response) in sunflowers. This response occurred even though leaves were concurrently exposed to PAR levels that normally induce a "sun" or high-PAR response in the absence of UV-B. Subambient levels of UV-B were also associated with a decrease in chloroplast and starch volume. Exposure to levels of UV-A 1/10 of ambient appeared to enhance the high-PAR response of the chloroplast, characterized by an increase in the amounts of stored starch, an increase in chloroplast volume density ratio values, and a decrease in thylakoid surface area density ratios relative to the high-light controls. These effects were opposite to those seen in UV-B-exposed tissue. In a general sense, subambient levels of UV-B evoked a response similar to that elicited by low-PAR irradiance, while subambient UV-A elicited responses similar to those typical of high-PAR irradiance. The fact that below-ambient levels of UV altered a normal chloroplast structural response to PAR provides evidence that UV may be an important environmental signal for plants.

  7. Ion irradiation induced defect evolution in Ni and Ni-based FCC equiatomic binary alloys

    NASA Astrophysics Data System (ADS)

    Jin, K.; Bei, H.; Zhang, Y.

    2016-04-01

    In order to explore the chemical effects on radiation response of alloys with multi-principal elements, defect evolution under Au ion irradiation was investigated in the elemental Ni, equiatomic NiCo and NiFe alloys. Single crystals were successfully grown in an optical floating zone furnace and their (100) surfaces were irradiated with 3 MeV Au ions at fluences ranging from 1 × 1013 to 5 × 1015 ions cm-2 at room temperature. The irradiation-induced defect evolution was analyzed by using ion channeling technique. Experiment shows that NiFe is more irradiation-resistant than NiCo and pure Ni at low fluences. With continuously increasing the ion fluences, damage level is eventually saturated for all materials but at different dose levels. The saturation level in pure Ni appears at relatively lower irradiation fluence than the alloys, suggesting that damage accumulation slows down in the alloys. Under high-fluence irradiations, pure Ni has wider damage ranges than the alloys, indicating that defects in pure Ni have high mobility.

  8. Ion irradiation induced defect evolution in Ni and Ni-based FCC equiatomic binary alloys

    SciTech Connect

    Jin, Ke; Zhang, Yanwen; Bei, Hongbin

    2016-01-01

    In order to explore the chemical effects on radiation response of alloys with multi-principal elements, defect evolution under Au ion irradiation was investigated in the elemental Ni, equiatomic NiCo and NiFe alloys. Single crystals were successfully grown in an optical floating zone furnace and their (100) surfaces were irradiated with 3 MeV Au ions at fluences ranging from 1 × 1013 to 5 × 1015 ions cm–2 at room temperature. The irradiation-induced defect evolution was analyzed by using ion channeling technique. Experiment shows that NiFe is more irradiation-resistant than NiCo and pure Ni at low fluences. With continuously increasing the ion fluences, damage level is eventually saturated for all materials but at different dose levels. The saturation level in pure Ni appears at relatively lower irradiation fluence than the alloys, suggesting that damage accumulation slows down in the alloys. Here, under high-fluence irradiations, pure Ni has wider damage ranges than the alloys, indicating that defects in pure Ni have high mobility.

  9. Ion irradiation induced defect evolution in Ni and Ni-based FCC equiatomic binary alloys

    DOE PAGES

    Jin, Ke; Zhang, Yanwen; Bei, Hongbin

    2016-01-01

    In order to explore the chemical effects on radiation response of alloys with multi-principal elements, defect evolution under Au ion irradiation was investigated in the elemental Ni, equiatomic NiCo and NiFe alloys. Single crystals were successfully grown in an optical floating zone furnace and their (100) surfaces were irradiated with 3 MeV Au ions at fluences ranging from 1 × 1013 to 5 × 1015 ions cm–2 at room temperature. The irradiation-induced defect evolution was analyzed by using ion channeling technique. Experiment shows that NiFe is more irradiation-resistant than NiCo and pure Ni at low fluences. With continuously increasing themore » ion fluences, damage level is eventually saturated for all materials but at different dose levels. The saturation level in pure Ni appears at relatively lower irradiation fluence than the alloys, suggesting that damage accumulation slows down in the alloys. Here, under high-fluence irradiations, pure Ni has wider damage ranges than the alloys, indicating that defects in pure Ni have high mobility.« less

  10. Irradiation-induced Ag nanocluster nucleation in silicate glasses: Analogy with photography

    SciTech Connect

    Espiau de Lamaestre, R.; Bea, H.; Bernas, H.; Belloni, J.; Marignier, J. L.

    2007-11-15

    The synthesis of Ag nanoclusters in soda lime silicate glasses and silica was studied by optical absorption and electron spin resonance experiments under both low (gamma ray) and high (MeV ion) deposited energy density irradiation conditions. Both types of irradiation create electrons and holes whose density and thermal evolution--notably via their interaction with defects--are shown to determine the clustering and growth rates of Ag nanocrystals. We thus establish the influence of redox interactions of defects and silver (poly)ions. The mechanisms are similar to the latent image formation in photography: Irradiation-induced photoelectrons are trapped within the glass matrix, notably on dissolved noble metal ions and defects, which are thus neutralized (reverse oxidation reactions are also shown to exist). Annealing promotes metal atom diffusion, which, in turn, leads to cluster nuclei formation. The cluster density depends not only on the irradiation fluence but also--and primarily--on the density of deposited energy and the redox properties of the glass. Ion irradiation (i.e., large deposited energy density) is far more effective in cluster formation, despite its lower neutralization efficiency (from Ag{sup +} to Ag{sup 0}) as compared to gamma photon irradiation.

  11. The p75 neurotrophin receptor regulates cranial irradiation-induced hippocampus-dependent cognitive dysfunction.

    PubMed

    Ding, Xin; Wu, Hao-Hao; Ji, Sheng-Jun; Cai, Shang; Dai, Pei-Wen; Xu, Mei-Ling; Zhang, Jun-Jun; Zhang, Qi-Xian; Tian, Ye; Ma, Quan-Hong

    2017-03-23

    Cognitive deficits, characterized by progressive problems with hippocampus-dependent learning, memory and spatial processing, are the most serious complication of cranial irradiation. However, the underlying mechanisms remain obscure. The p75 neurotrophin receptor (p75NTR) is involved in a diverse arrays of cellular responses, including neurite outgrowth, neurogenesis, and negative regulation of spine density, which are associated with various neurological disorders. In this study, male Sprague-Dawley (SD) rats received 10 Gy cranial irradiation. Then, we evaluated the expression of p75NTR in the hippocampus after cranial irradiation and explored its potential role in radiation-induced synaptic dysfunction and memory deficits. We found that the expression of p75NTR was significantly increased in the irradiated rat hippocampus. Knockdown of p75NTR by intrahippocampal infusion of AAV8-shp75 ameliorated dendritic spine abnormalities, and restored synapse-related protein levels, thus preventing memory deficits, likely through normalization the phosphor-AKT activity. Moreover, viral-mediated overexpression of p75NTR in the normal hippocampus reproduced learning and memory deficits. Overall, this study demonstrates that p75NTR is an important mediator of irradiation-induced cognitive deficits by regulating dendritic development and synapse structure.

  12. The fine structure of electron irradiation induced EL2-like defects in n-GaAs

    NASA Astrophysics Data System (ADS)

    Tunhuma, S. M.; Auret, F. D.; Legodi, M. J.; Diale, M.

    2016-04-01

    Defects induced by electron irradiation in n-GaAs have been studied using deep level transient spectroscopy (DLTS) and Laplace DLTS (L-DLTS). The E0.83 (EL2) is the only defect observed prior to irradiation. Ru/n-GaAs Schottky diodes were irradiated with high energy electrons from a Sr-90 radionuclide up to a fluence of 2.45 × 1013 cm-2. The prominent electron irradiation induced defects, E0.04, E0.14, E0.38, and E0.63, were observed together with the metastable E0.17. Using L-DLTS, we observed the fine structure of a broad base EL2-like defect peak. This was found to be made up of the E0.75, E0.83, and E0.85 defects. Our study reveals that high energy electron irradiation increases the concentration of the E0.83 defect and introduces a family of defects with electronic properties similar to those of the EL2.

  13. Irradiation-induced structural changes in surveillance material of VVER 440-type weld metal

    NASA Astrophysics Data System (ADS)

    Grosse, M.; Denner, V.; Böhmert, J.; Mathon, M.-H.

    2000-01-01

    The irradiation-induced microstructural changes in surveillance materials of the VVER 440-type weld metal Sv-10KhMFT were investigated by small angle neutron scattering (SANS) and anomalous small angle X-ray scattering (SAXS). Due to the high fluence, a strong effect was found in the SANS experiment. No significant effect of the irradiation is detected by SAXS. The reason for this discrepancy is the different scattering contrast of irradiation-induced defects for neutrons and X-rays. An analysis of the SAXS shows that the scattering intensity is mainly caused by vanadium-containing (VC) precipitates and grain boundaries. Both types of scattering defects are hardly changed by irradiation. Neutron irradiation rather produces additional scattering defects of a few nanometers in size. Assuming these defects are clusters containing copper and other foreign atoms with a composition according to results of atom probe field ion microscopy (APFIM) investigations, both the high SANS and the low SAXS effect can be explained.

  14. Volatile evolution from polymer materials induced by irradiation with He ++ ions and comparative pyrolysis experiments

    NASA Astrophysics Data System (ADS)

    Murphy, J. J.; Patel, M.; Skinner, A. R.; Horn, I. M.; Powell, S. J.; Smith, P. F.

    2004-02-01

    Irradiation of polymer samples using an accelerated beam of He ++ ions passed through a 10 μm thick window of Havar foil has been performed. Such an irradiation simulates the effects of large α radiation doses on a vastly reduced time-scale. The experimental set up was designed so that the irradiated materials were contained within a small sample chamber. This chamber was isolated from the main vacuum chamber of the ion beam by means of the Havar foil window. A mass spectrometer linked directly to the sample chamber was used to analyse gaseous products evolved from the materials under irradiation. Samples of a material in which the polymer phase was an ethylenevinylacetate/polyvinylalcohol composite material indicated increased CO 2 and CO evolution upon irradiation. This material, however, evolved a considerable amount of volatiles even without irradiation and so a detailed mechanistic interpretation of the results is not possible. A foamed poly(siloxane) material evolved a number of volatile species upon irradiation and possible chemical degradation mechanisms are commented upon. The sample was extremely resistant to radiation induced degradation as measured by volatile evolution though, so again a detailed mechanistic analysis is not possible. Samples of a polyester based polyurethane evolved CO 2, CO and a number of high mass volatile species. Assignment of chemical structures to the main molecular ions allows deductions about the chemistry underlying radiation induced change to be made. Furthermore, identification of trends in volatile production allows information about potential degradation mechanisms to be deduced. To assess the contribution of sample heating on volatile evolution a series of pyrolysis experiments were performed. These indicate no evolution of volatiles below 100 °C and evolution of volatiles possessing masses of greater than 50 amu only at temperature of above 300 °C.

  15. Thermal effects in tissues induced by interstitial irradiation of near infrared laser with a cylindrical diffuser

    NASA Astrophysics Data System (ADS)

    Le, Kelvin; Johsi, Chet; Figueroa, Daniel; Goddard, Jessica; Li, Xiaosong; Towner, Rheal A.; Saunders, Debra; Smith, Nataliya; Liu, Hong; Hode, Tomas; Nordquist, Robert E.; Chen, Wei R.

    2011-03-01

    Laser immunotherapy (LIT), using non-invasive laser irradiation, has resulted in promising outcomes in the treatment of late-stage cancer patients. However, the tissue absorption of laser light limits the clinical applications of LIT in patients with dark skin, or with deep tumors. The present study is designed to investigate the thermal effects of interstitial irradiation using an 805-nm laser with a cylindrical diffuser, in order to overcome the limitations of the non-invasive mode of treatment. Cow liver and rat tumors were irradiated using interstitial fiber. The temperature increase was monitored by thermocouples that were inserted into the tissue at different sites around the cylinder fiber. Three-dimensional temperature distribution in target tissues during and after interstitial laser irradiation was also determined by Proton Resonance Frequency. The preliminary results showed that the output power of laser and the optical parameters of the target tissue determined the light distribution in the tissue. The temperature distributions varied in the tissue according to the locations relative to the active tip of the cylindrical diffuser. The temperature increase is strongly related to the laser power and irradiation time. Our results using thermocouples and optical sensors indicated that the PRF method is reliable and accurate for temperature determination. Although the inhomogeneous biological tissues could result in temperature fluctuation, the temperature trend still can be reliable enough for the guidance of interstitial irradiation. While this study provides temperature profiles in tumor tissue during interstitial irradiation, the biological effects of the irradiation remain unclear. Future studies will be needed, particularly in combination with the application of immunostimulant for inducing tumor-specific immune responses in the treatment of metastatic tumors.

  16. Irradiation-induced disordering and amorphization of Al3Ti-based intermetallic compounds

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Yong; Kim, Il-Hyun; Motta, Arthur T.; Ulmer, Christopher J.; Kirk, Marquis A.; Ryan, Edward A.; Baldo, Peter M.

    2015-12-01

    An in situ ion-irradiation study, simultaneously examined using transmission electron microscopy, was performed to investigate irradiation-induced disordering and amorphization of Al3Ti-based intermetallic compounds. Thin foil samples of two crystalline structures: D022-structured Al3Ti and L12-structured (Al,Cr)3Ti were irradiated using 1.0 MeV Kr ions at a temperature range from 40 K to 573 K to doses up to 4.06 × 1015 ions/cm2. The results showed that both the compounds underwent an order-disorder transformation under irradiation, where both Al3Ti and (Al,Cr)3Ti ordered structures were fully transformed to the disordered face-centered cubic (FCC) structure except at the highest irradiation temperature of 573 K. A slightly higher irradiation dose was required for order-disorder transformation in case of Al3Ti as compared to (Al,Cr)3Ti at a given temperature. However, their amorphization resistances were different: while the disordered FCC (Al,Cr)3Ti amorphized at the irradiation dose of 6.25 × 1014 ions/cm2 (0.92 dpa) at 40 K and 100 K, the Al3Ti compound with the same disordered FCC structure maintained crystallinity up to 4.06 × 1015 ions/cm2 (5.62 dpa) at 40 K. The critical temperature for amorphization of (Al,Cr)3Ti under Kr ion irradiation is likely between 100 K and room temperature and the critical temperature for disordering between room temperature and 573 K.

  17. High-dose irradiation induces cell cycle arrest, apoptosis, and developmental defects during Drosophila oogenesis.

    PubMed

    Shim, Hee Jin; Lee, Eun-Mi; Nguyen, Long Duy; Shim, Jaekyung; Song, Young-Han

    2014-01-01

    Ionizing radiation (IR) treatment induces a DNA damage response, including cell cycle arrest, DNA repair, and apoptosis in metazoan somatic cells. Because little has been reported in germline cells, we performed a temporal analysis of the DNA damage response utilizing Drosophila oogenesis as a model system. Oogenesis in the adult Drosophila female begins with the generation of 16-cell cyst by four mitotic divisions of a cystoblast derived from the germline stem cells. We found that high-dose irradiation induced S and G2 arrests in these mitotically dividing germline cells in a grp/Chk1- and mnk/Chk2-dependent manner. However, the upstream kinase mei-41, Drosophila ATR ortholog, was required for the S-phase checkpoint but not for the G2 arrest. As in somatic cells, mnk/Chk2 and dp53 were required for the major cell death observed in early oogenesis when oocyte selection and meiotic recombination occurs. Similar to the unscheduled DNA double-strand breaks (DSBs) generated from defective repair during meiotic recombination, IR-induced DSBs produced developmental defects affecting the spherical morphology of meiotic chromosomes and dorsal-ventral patterning. Moreover, various morphological abnormalities in the ovary were detected after irradiation. Most of the IR-induced defects observed in oogenesis were reversible and were restored between 24 and 96 h after irradiation. These defects in oogenesis severely reduced daily egg production and the hatch rate of the embryos of irradiated female. In summary, irradiated germline cells induced DSBs, cell cycle arrest, apoptosis, and developmental defects resulting in reduction of egg production and defective embryogenesis.

  18. Plasmonic enhancement of the vanadium dioxide phase transition induced by low-power laser irradiation

    NASA Astrophysics Data System (ADS)

    Ferrara, Davon W.; MacQuarrie, Evan R.; Diez-Blanco, Victor; Nag, Joyeeta; Kaye, Anthony B.; Haglund, Richard F.

    2012-08-01

    Nanocomposites consisting of gold nanoparticle (NP) arrays and vanadium dioxide (VO2) thin films are noteworthy for the tunability of both their thermal and optical properties. The localized surface plasmon resonance (LSPR) of the Au can be tuned when its dielectric environment is modulated by the semiconducting-to-metal phase transition (SMT) of the VO2; the LSPR itself can be altered by changing the shape of the NPs and the pitch of the NP array. In principle, then it should be possible to choose a combination of VO2 film and Au LSPR properties that maximizes the overall optical response of the nanocomposite. To demonstrate this effect, transient transmission measurements were conducted on lithographically fabricated arrays of Au NPs of diameter 140 nm, array spacing 350 nm, and covered with a 60 nm thick films of VO2 via pulsed laser deposition. Both Au::VO2 nanocomposites and bare VO2 film were irradiated with a shuttered 785 nm pump laser, and their optical response was probed at 1550 nm by a fixed-frequency diode laser. The Au::VO2 nanocomposite exhibited an increased effective absorption coefficient 1.5 times that of the plain film and required 37 % less laser power to induce the SMT. The time-dependent temperature rise in the film as a function of laser intensity was calculated from these measurements and compared with both analytic and finite-element models. Our results suggest that Au::VO2 nanocomposites may be useful in applications such as thermal-management coatings for energy efficient "smart" windows.

  19. In-Utero Low-Dose Irradiation Leads to Persistent Alterations in the Mouse Heart Proteome

    PubMed Central

    Bakshi, Mayur V.; Azimzadeh, Omid; Merl-Pham, Juliane; Verreet, Tine; Hauck, Stefanie M.; Benotmane, Mohammed A.; Atkinson, Michael J.; Tapio, Soile

    2016-01-01

    Prenatal exposure to stress such as increased level of reactive oxygen species or antiviral therapy are known factors leading to adult heart defects. The risks following a radiation exposure during fetal period are unknown, as are the mechanisms of any potential cardiac damage. The aim of this study was to gather evidence for possible damage by investigating long-term changes in the mouse heart proteome after prenatal exposure to low and moderate radiation doses. Pregnant C57Bl/6J mice received on embryonic day 11 (E11) a single total body dose of ionizing radiation that ranged from 0.02 Gy to 1.0 Gy. The offspring were sacrificed at the age of 6 months or 2 years. Quantitative proteomic analysis of heart tissue was performed using Isotope Coded Protein Label technology and tandem mass spectrometry. The proteomics data were analyzed by bioinformatics and key changes were validated by immunoblotting. Persistent changes were observed in the expression of proteins representing mitochondrial respiratory complexes, redox and heat shock response, and the cytoskeleton, even at the low dose of 0.1 Gy. The level of total and active form of the kinase MAP4K4 that is essential for the embryonic development of mouse heart was persistently decreased at the radiation dose of 1.0 Gy. This study provides the first insight into the molecular mechanisms of cardiac impairment induced by ionizing radiation exposure during the prenatal period. PMID:27276052

  20. Helium-induced weld cracking in irradiated 304 stainless steel

    SciTech Connect

    Birchenall, A.K. )

    1989-01-01

    This report consists of slide notes for presentation to The Metallurgical Society of the American Institute of Mining, Metallurgical and Petroleum Engineers (AIME). The meeting in question will be held October 3, 1989 in Indianapolis. This presentation will be the second of three consecutive talks contributed by SRL personnel dealing with helium-induced weld cracking.

  1. Gamma-tocopherol-N,N-dimethylglycine ester as a potent post-irradiation mitigator against whole body X-irradiation-induced bone marrow death in mice.

    PubMed

    Anzai, Kazunori; Ueno, Megumi; Matsumoto, Ken-Ichiro; Ikota, Nobuo; Takata, Jiro

    2014-01-01

    We examined the radioprotective and mitigative effects of gamma-tocopherol-N,N-dimethylglycine ester (GTDMG), a novel water-soluble gamma-tocopherol derivative, against X-irradiation-induced bone marrow death in mice. Mice (C3H, 10 weeks, male) were injected intraperitoneally with GTDMG suspended in a 0.5% methyl cellulose solution before or after receiving of 7.5-Gy whole body X-irradiation. GTDMG significantly enhanced the 30-day survival rate when given 30 min before or immediately after the irradiation. Its mitigative activity (administered after exposure) was examined further in detail. The optimal concentration of GTDMG given immediately after irradiation was around 100 mg/kg body weight (bw) and the 30-day survival rate was 97.6 ± 2.4%. When GTDMG was administered 1, 10 and 24 h post-irradiation, the survival rate was 85.7 ± 7.6, 75.0 ± 9.7 and 36.7 ± 8.8%, respectively, showing significant mitigation even at 24 h after irradiation (P < 0.05). The value of the dose reduction factor (100 mg/kg bw, given intraperitoneally (i.p.) immediately after irradiation) was 1.25. GTDMG enhanced the recovery of red blood cell-, white blood cell-, and platelet-counts after irradiation and significantly increased the number of endogenous spleen colonies (P < 0.05). Subcutaneous (s.c.) administration also had mitigative effects. In conclusion, GTDMG is a potent radiation mitigator.

  2. Chemical patterning of Ag(111): Spatially confined oxide formation induced by electron beam irradiation

    SciTech Connect

    Guenther, S.; Reichelt, R.; Wintterlin, J.; Barinov, A.; Mentes, T. O.; Nino, M. A.; Locatelli, A.

    2008-12-08

    Low energy electron irradiation of a Ag(111) surface during NO{sub 2} adsorption at 300 K induces formation of Ag oxide. Using a spatially confined electron beam, small Ag{sub 2}O spots could be grown with a sharp, {approx}100 nm wide, boundary to the nonirradiated metallic surface. Since the structure size will mainly depend on the sharpness of the irradiating electron beam, this process has the potential of a single step nanostructuring process. Temperature treatment offers an easy way to manipulate the boundary between oxide and metallic silver by steering a chemical front.

  3. Reversible Hydrophobic to Hydrophilic Transition in Graphene via Water Splitting Induced by UV Irradiation

    PubMed Central

    Xu, Zhemi; Ao, Zhimin; Chu, Dewei; Younis, Adnan; Li, Chang Ming; Li, Sean

    2014-01-01

    Although the reversible wettability transition between hydrophobic and hydrophilic graphene under ultraviolet (UV) irradiation has been observed, the mechanism for this phenomenon remains unclear. In this work, experimental and theoretical investigations demonstrate that the H2O molecules are split into hydrogen and hydroxyl radicals, which are then captured by the graphene surface through chemical binding in an ambient environment under UV irradiation. The dissociative adsorption of H2O molecules induces the wettability transition in graphene from hydrophobic to hydrophilic. Our discovery may hold promise for the potential application of graphene in water splitting. PMID:25245110

  4. Ageing and thermal recovery of paramagnetic centers induced by electron irradiation in yttria-stabilized zirconia

    NASA Astrophysics Data System (ADS)

    Costantini, J. M.; Beuneu, F.

    We have used electron spin resonance spectroscopy to study the defects induced in yttria-stabilized zirconia (YSZ) single crystals by 2.5-MeV electron irradiations. Two paramagnetic centers are produced: the first one with an axial <111> symmetry is similar to the trigonal Zr3+ electron center (T center) found after X-ray irradiation or thermo-chemical reduction, whereas the second one is a new oxygen hole center with an axial <100> symmetry different from the orthorhombic O- center induced by X-ray irradiation. At a fluence around 10(18) e/cm(2) , both centers are bleached out near 600 K, like the corresponding X-ray induced defects. At a fluence around 10(19) e/cm(2) , defects are much more stable, since complete thermal bleaching occurs near 1000 K. Accordingly, ageing of as-irradiated samples shows that high-dose defects at more stable than the low-dose ones.

  5. Electron Irradiation Induced Phase Transition of an Amorphous Phase and Face-Centered Cubic Solid Solutions in Zr66.7Pd33.3 Metallic Glass

    NASA Astrophysics Data System (ADS)

    Nagase, Takeshi; Hosokawa, Takashi; Umakoshi, Yukichi

    2007-02-01

    Both amorphization and crystallization were observed in Zr66.7Pd33.3 metallic glass under electron irradiation. The melt-spun amorphous phase was not stable under 2.0 MV electron irradiation and two kinds of fcc-solid solution were precipitated through electron irradiation induced crystallization at 103 and 298 K. The fcc-solid solution obtained by electron irradiation induced crystallization at 298 K transformed to an amorphous phase during irradiation at 103 K. Electron irradiation induced phase transformation behavior in Zr66.7Pd33.3 metallic glass can be explained by phase stability of an amorphous phase and crystalline phases against electron irradiation.

  6. Total body 100-mGy X-irradiation does not induce Alzheimer's disease-like pathogenesis or memory impairment in mice

    PubMed Central

    Wang, Bing; Tanaka, Kaoru; Ji, Bin; Ono, Maiko; Fang, Yaqun; Ninomiya, Yasuharu; Maruyama, Kouichi; Izumi-Nakajima, Nakako; Begum, Nasrin; Higuchi, Makoto; Fujimori, Akira; Uehara, Yoshihiko; Nakajima, Tetsuo; Suhara, Tetsuya; Ono, Tetsuya; Nenoi, Mitsuru

    2014-01-01

    The cause and progression of Alzheimer's disease (AD) are poorly understood. Possible cognitive and behavioral consequences induced by low-dose radiation are important because humans are exposed to ionizing radiation from various sources. Early transcriptional response in murine brain to low-dose X-rays (100 mGy) has been reported, suggesting alterations of molecular networks and pathways associated with cognitive functions, advanced aging and AD. To investigate acute and late transcriptional, pathological and cognitive consequences of low-dose radiation, we applied an acute dose of 100-mGy total body irradiation (TBI) with X-rays to C57BL/6J Jms mice. We collected hippocampi and analyzed expression of 84 AD-related genes. Mouse learning ability and memory were assessed with the Morris water maze test. We performed in vivo PET scans with 11C-PIB, a radiolabeled ligand for amyloid imaging, to detect fibrillary amyloid beta peptide (Aβ) accumulation, and examined characteristic AD pathologies with immunohistochemical staining of amyloid precursor protein (APP), Aβ, tau and phosphorylated tau (p-tau). mRNA studies showed significant downregulation of only two of 84 AD-related genes, Apbb1 and Lrp1, at 4 h after irradiation, and of only one gene, Il1α, at 1 year after irradiation. Spatial learning ability and memory were not significantly affected at 1 or 2 years after irradiation. No induction of amyloid fibrillogenesis or changes in APP, Aβ, tau, or p-tau expression was detected at 4 months or 2 years after irradiation. TBI induced early or late transcriptional alteration in only a few AD-related genes but did not significantly affect spatial learning, memory or AD-like pathological change in mice. PMID:23908553

  7. Total body 100-mGy X-irradiation does not induce Alzheimer's disease-like pathogenesis or memory impairment in mice.

    PubMed

    Wang, Bing; Tanaka, Kaoru; Ji, Bin; Ono, Maiko; Fang, Yaqun; Ninomiya, Yasuharu; Maruyama, Kouichi; Izumi-Nakajima, Nakako; Begum, Nasrin; Higuchi, Makoto; Fujimori, Akira; Uehara, Yoshihiko; Nakajima, Tetsuo; Suhara, Tetsuya; Ono, Tetsuya; Nenoi, Mitsuru

    2014-01-01

    The cause and progression of Alzheimer's disease (AD) are poorly understood. Possible cognitive and behavioral consequences induced by low-dose radiation are important because humans are exposed to ionizing radiation from various sources. Early transcriptional response in murine brain to low-dose X-rays (100 mGy) has been reported, suggesting alterations of molecular networks and pathways associated with cognitive functions, advanced aging and AD. To investigate acute and late transcriptional, pathological and cognitive consequences of low-dose radiation, we applied an acute dose of 100-mGy total body irradiation (TBI) with X-rays to C57BL/6J Jms mice. We collected hippocampi and analyzed expression of 84 AD-related genes. Mouse learning ability and memory were assessed with the Morris water maze test. We performed in vivo PET scans with (11)C-PIB, a radiolabeled ligand for amyloid imaging, to detect fibrillary amyloid beta peptide (Aβ) accumulation, and examined characteristic AD pathologies with immunohistochemical staining of amyloid precursor protein (APP), Aβ, tau and phosphorylated tau (p-tau). mRNA studies showed significant downregulation of only two of 84 AD-related genes, Apbb1 and Lrp1, at 4 h after irradiation, and of only one gene, Il1α, at 1 year after irradiation. Spatial learning ability and memory were not significantly affected at 1 or 2 years after irradiation. No induction of amyloid fibrillogenesis or changes in APP, Aβ, tau, or p-tau expression was detected at 4 months or 2 years after irradiation. TBI induced early or late transcriptional alteration in only a few AD-related genes but did not significantly affect spatial learning, memory or AD-like pathological change in mice.

  8. Molecular weight changes induced in an anionic polydimethylsiloxane by gamma irradiation in vacuum

    NASA Astrophysics Data System (ADS)

    Satti, Angel J.; Andreucetti, Noemí A.; Ciolino, Andrés E.; Vitale, Cristian; Sarmoria, Claudia; Vallés, Enrique M.

    2010-11-01

    An anionic almost monodisperse linear polydimethylsiloxane (PDMS) was subjected to gamma irradiation under vacuum at room temperature. The molecular weight changes induced by the radiation process have been investigated using size exclusion chromatography (SEC) with refraction index (RI) and multi angle laser light scattering (MALLS) detectors, to obtain the number and weight average molecular weights of the irradiated samples. The analysis of the data indicates that crosslinking reactions predominated over scission reactions. The results obtained by an SEC-RI have confirmed the presence of small, but measurable amounts of scission. A previously developed mathematical model of the irradiation process that accounts for simultaneous scission and crosslinking and allows for both H- and Y-crosslinks, fitted well the measured molecular weight data. This prediction is in accordance with the experimental data obtained by 29Si-Nuclear Magnetic Resonance spectroscopy (NMR) and previously reported data for commercial linear PDMS ( Satti et al., 2008).

  9. Irradiation-induced nano-voids in strained tin precipitates in silicon

    NASA Astrophysics Data System (ADS)

    Gaiduk, P. I.; Lundsgaard Hansen, J.; Nylandsted Larsen, A.

    2014-04-01

    We report on self-assembling of spherically shaped voids in nanometer size strained Sn precipitates after irradiation with He+ ions in different conditions. It is found that high-temperature irradiation induces vacancies which are collected by compressively strained Sn precipitates enhancing of out-diffusion of Sn atoms from the precipitates. Nano-voids formation takes place simultaneously with a β- to α-phase transformation in the Sn precipitates. Post-irradiation thermal treatment leads to the removal of voids and a backward transformation of the Sn phase to β-phase. Strain-enhanced separation of point defects along with vacancy assisted Sn out-diffusion and precipitate dissolution are discussed.

  10. Radiation-Induced Centers in Lead Silicate Glasses Irradiated by Stationary and Pulsed Electron Beams

    NASA Astrophysics Data System (ADS)

    Zhidkov, I. S.; Zatsepin, A. F.; Konev, S. F.; Cholakh, S. O.

    2015-08-01

    Radiation-induced centers formed in heavy flint glasses irradiated by electron beams are investigated by the methods of optical and EPR spectroscopy. It is revealed that stable and short-living optical absorption centers of close natures are formed under irradiation by fast electrons. A correlation is established between the stable optical absorption bands and the EPR signals interpreted as signals of the (Pb2+)/h+ hole centers. The shortliving color centers are formed due to short-term distortion of the O-Pb bonds, and the stable centers are formed due to the spatial separation, thermalization, and subsequent stabilization of excited electrons and holes in tails of the localized states. Irradiation by electron beams leads to a change in the spectral characteristics of the fundamental absorption edge and, in particular, of the Urbach energy that determines the degree of structural disorder.

  11. Investigation on Large Molecule Permeation through Liposome Lipid Bilayer Induced by Microplasma Irradiation

    NASA Astrophysics Data System (ADS)

    Nagaiwa, Hidenori; Aibara, Daijiro; Ikeda, Yoshihisa; Motomura, Hideki; Kido, Yugo; Satoh, Susumu; Tachibana, Kunihide; Jinno, Masahumi

    2015-09-01

    The authors have been developing a novel gene transfection method using microplasma irradiation. In order to clarify the mechanism of large molecule permeation process through the lipid bilayer, plasma induced outflow of hydrophilic fluorescent dye molecules, which were encapsulated in the liposome, was observed. By microplasma irradiation on the liposome suspension, the dyes flowed out from the inside of the liposomes. The outflow of the dyes was enhanced by longer plasma irradiation time. Investigation of the outflow mechanism, i.e. permeation enhancement of the lipid bilayer or burst of the liposome, is under progress. This work was partly supported by JSPS KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas (Number 25108509,15H00896) and a grant from Ehime University.

  12. Laser-induced point-defect reaction in proton-irradiated SiC

    NASA Astrophysics Data System (ADS)

    Zimbone, M.; Litrico, G.; Barbera, M.; Baratta, G. A.; Foti, G.

    2009-01-01

    The defects produced in 4H-SiC epitaxial layers by irradiation with 200-keV H+ were characterized by low-temperature photoluminescence. These defects induce sharp luminescent lines, the so-called alphabet lines. Their intensity shows an evolution under UV-laser irradiation not previously observed. By monitoring the change in the resulting photoluminescence spectra versus time, we distinguish two original ‘families’ of peaks called PB1 and PB2. They display a different, and opposite, behaviour with laser irradiation but they are strongly correlated. In particular, the recovering rate of the PB1 family and the growth rate of the PB2 family are the same, indicating a structural rearrangement of defects.

  13. Characterization of 3 MeV H + irradiation induced defects in nuclear grade graphite

    NASA Astrophysics Data System (ADS)

    Kim, Eung-Seon; Kim, Yong-Wan

    2010-09-01

    Atomistic structure change in a nuclear grade graphite irradiated at 353 K to 3.4×10 17 ion/cm 2 with 3 MeV H + was characterized by measuring positron lifetime and Raman spectrum at room temperature. It is evident from the positron lifetime results that the pre-existing structural defect is disoriented crystalline boundaries, and vacancy clusters ranging from di- to quadruple-vacancies were newly formed after ion irradiation. The relative intensity ratio of the Raman D and G peaks increased from 0.25 to 0.67 after ion irradiation. The concentration of radiation-induced vacancies was reasonably estimated by the Raman intensity ratio.

  14. Gamma-ray irradiation induced bulk photochromism in WO3-P2O5 glass

    NASA Astrophysics Data System (ADS)

    Shen, Wei; Baccaro, Stefania; Cemmi, Alessia; Xu, Xiaoqing; Chen, Guorong

    2015-11-01

    In the present work, photochromism of WO3-P2O5 glass under gamma-ray irradiation was reported. As-prepared glass samples with different WO3 content are all optically transparent in the visible wavelength range thanks to the addition of a small amount of oxidizing couple Sb2O3-NaNO3. The photochromic properties are identified by transmission spectra of the glasses before and after irradiation. The results show that the irradiation induced darkening results from the reduction of W6+ to W5+ or W4+. The existence of WO6 clusters in glasses of high WO3 content is proved by XPS, which is the main reason for the obvious photochromic effects. The WO3-P2O5 glass is a promising candidate in gamma-ray sensitive detector.

  15. Induced parthenogenesis by gamma-irradiated pollen in loquat for haploid production

    PubMed Central

    Blasco, Manuel; Badenes, María Luisa; del Mar Naval, María

    2016-01-01

    Successful haploid induction in loquat (Eriobotrya japonica (Thunb.) Lindl.) through in situ-induced parthenogenesis with gamma-ray irradiated pollen has been achieved. Female flowers of cultivar ‘Algerie’ were pollinated using pollen of cultivars ‘Changhong-3’, ‘Cox’ and ‘Saval Brasil’ irradiated with two doses of gamma rays, 150 and 300 Gy. The fruits were harvested 90, 105 and 120 days after pollination (dap). Four haploid plants were obtained from ‘Algerie’ pollinated with 300-Gy-treated pollen of ‘Saval Brasil’ from fruits harvested 105 dap. Haploidy was confirmed by flow cytometry and chromosome count. The haploids showed a very weak development compared to the diploid plants. This result suggests that irradiated pollen can be used to obtain parthenogenetic haploids. PMID:27795686

  16. Deep levels induced by high fluence proton irradiation in undoped GaAs diodes

    SciTech Connect

    Castaldini, A.; Cavallini, A.; Polenta, L.; Canali, C.; Nava, F.; Ferrini, R.; Galli, M.

    1998-12-31

    Semi-insulating liquid encapsulated Czochralski grown GaAs has been investigated after irradiation at high fluences of high-energy protons. Electron beam induced current observations of scanning electron microscopy evidenced a radiation stimulated ordering. An analysis has been carried out of the deep levels associated with defects as a function of the irradiation fluence, using complementary current transient spectroscopies. By increasing the irradiation fluence, the concentration of the native traps at 0.37 eV together with that of the EL2 defect significantly increases and, at the same time, two new electron traps at 0.15 eV and 0.18 eV arise and quickly increase in density.

  17. Irradiation-induced nano-voids in strained tin precipitates in silicon

    SciTech Connect

    Gaiduk, P. I.; Lundsgaard Hansen, J. Nylandsted Larsen, A.

    2014-04-14

    We report on self-assembling of spherically shaped voids in nanometer size strained Sn precipitates after irradiation with He{sup +} ions in different conditions. It is found that high-temperature irradiation induces vacancies which are collected by compressively strained Sn precipitates enhancing of out-diffusion of Sn atoms from the precipitates. Nano-voids formation takes place simultaneously with a β- to α-phase transformation in the Sn precipitates. Post-irradiation thermal treatment leads to the removal of voids and a backward transformation of the Sn phase to β-phase. Strain-enhanced separation of point defects along with vacancy assisted Sn out-diffusion and precipitate dissolution are discussed.

  18. Pattern-induced magnetic anisotropy in FePt thin films by ion irradiation

    SciTech Connect

    Jaafar, M.; Sanz, R.; McCord, J.; Jensen, J.; Schaefer, R.; Vazquez, M.; Asenjo, A.

    2011-03-01

    The magnetic properties of FePt thin films have been modified by exposing the samples to irradiation of 4 MeV Cl{sup 2+} ions. Patterned magnetic films, without modified topographical profile, were fabricated by irradiating the films through a shadowing micrometric mask. The structural changes, ascribed to the ion-beam-induced amorphization of the thin films, promote the modification of the magnetic anisotropy. In particular, the out-of-plane component of the magnetization decreases simultaneously with an enhancement of in-plane anisotropy by increasing ion fluence. Moreover, the nonirradiated regions present unexpected anisotropic behavior owing to the stray field of the irradiated regions. The control of this effect, which can have unwished consequences for the patterning of magnetic properties by ion bombardment, needs to be suitably addressed.

  19. Isolation of the role of radiation-induced segregation in irradiation-assisted stress corrosion cracking of proton-irradiated austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Busby, Jeremy Todd

    2001-11-01

    The role of radiation-induced segregation (RIS) in irradiation-assisted stress corrosion cracking (IASCC) was studied in order to better understand the underlying mechanisms of IASCC. High-purity 304L (HP-304L), commercial purity 304 (CP-304) and commercial purity 316 (CP-316) stainless steel alloys were irradiated with 3.2 MeV protons at 400°C (HP-304L) and 360°C (CP-304 and CP-316) to doses ranging from 0.1 and 5.0 dpa. Grain boundary chemistry was measured using scanning transmission electron microscopy with energy-dispersive spectroscopy (STEM/EDS) in both unirradiated and irradiated samples. Unirradiated and irradiated samples of the two commercial purity alloys were also strained to failure in an aqueous environment representative of boiling water reactor cores. The cracking susceptibility and RIS in the proton-irradiated CP-304 is very similar to that from the neutron-irradiated samples. The CP-316 alloy did not crack. Radiation-induced segregation, cracking susceptibility, and dislocation loop microstructure developed at the same rate as a function of dose in the CP-304 alloy. To isolate the effects of RIS in IASCC, post-irradiation annealing was utilized. Simulations of post-irradiation annealing of RIS and dislocation loop microstructure show that dislocation loops are removed preferentially over RIS due to the density of vacancies required and kinetic considerations. Experimental anneals were conducted on HP-304L samples irradiated to 1.0 dpa and CP-304 samples irradiated to 1.0 and 2.5 dpa. Post-irradiation anneals were performed at temperatures ranging from 400°C to 650°C for times between 45 minutes and 5 hours. At all temperatures, the hardness and dislocation densities decreased with increasing annealing time much faster than RIS did. Annealing at 600°C for 90 minutes removed virtually all dislocation microstructure while leaving RIS intact. Cracking susceptibility in the CP-304 alloy was mitigated rapidly during post-irradiation annealing

  20. The effects of celecoxib, a COX-2 selective inhibitor, on acute inflammation induced in irradiated rats.

    PubMed

    Khayyal, M T; El-Ghazaly, Mona A; El-Hazek, R M; Nada, A S

    2009-10-01

    The potential value of selective and non-selective COX-2 inhibitors in preventing some of the biochemical changes induced by ionizing radiation was studied in rats exposed to carrageenan-induced paw edema and 6-day-old air pouch models. The animals were exposed to different exposure levels of gamma-radiation, namely either to single doses of 2 and 7.5 Gy or a fractionated dose level of 7.5 Gy delivered as 0.5 Gy twice weekly for 7.5 weeks. The inflammatory response produced by carrageenan in irradiated rats was markedly higher than that induced in non-irradiated animals, and depended on the extent of irradiation. Celecoxib, a selective COX-2 inhibitor, in doses of 3, 5, 10, and 15 mg/kg was effective in reducing paw edema in irradiated and non-irradiated rats in a dose-dependent manner as well as diclofenac (3 mg/kg), a non-selective COX inhibitor. Irradiation of animals before the induction of the air pouch by an acute dose of 2 Gy led to a significant increase in leukocytic count, as well as in the level of interleukin-6 (IL-6), interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), LTB(4), PGE(2) (as an index of COX-2 activity), TXB(2) (as an index of COX-1 activity), and the plasma level of MDA. This increase in level of these parameters was more marked than that observed in the non-irradiated animals subjected to the inflammagen. The blood GSH level was not affected by the dose of irradiation used, whereas superoxide dismutase (SOD) activity was suppressed. In many respects, celecoxib (5 mg/kg) was as potent as diclofenac in decreasing the elevated levels of IL-6, IL-1beta, TNF-alpha, LTB(4), PGE(2), but lacked any significant effect on TXB(2) level. Since it is mostly selective for COX-2 with a rare effect on COX-1 enzyme, both drugs at the selected dose levels showed no effect on level of MDA, GSH, and SOD activity.

  1. Developmental toxicity and oxidative stress induced by gamma irradiation in zebrafish embryos.

    PubMed

    Hu, Miao; Hu, Nan; Ding, Dexin; Zhao, Weichao; Feng, Yongfu; Zhang, Hui; Li, Guangyue; Wang, Yongdong

    2016-11-01

    This study aimed to evaluate the biological effects of gamma irradiation on zebrafish embryos. Different doses of gamma rays (0.01, 0.05, 0.1, 0.5 and 1 Gy) were used to irradiate zebrafish embryos at three developmental stages (stage 1, 6 h post-fertilization (hpf); stage 2, 12 hpf; stage three, 24 hpf), respectively. The survival, malformation and hatching rates of the zebrafish embryos were measured at the morphological endpoint of 96 hpf. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed. Morphology analysis showed that gamma irradiation inhibited hatching and induced developmental toxicity in a dose-dependent manner. Interestingly, after irradiation the malformation rate changed not only in a dose-dependent manner but also in a developmental stage-dependent manner, indicating that the zebrafish embryos at stage 1 were more sensitive to gamma rays than those at other stages. Biochemical analysis showed that gamma irradiation modulated the activities of antioxidant enzymes in a dose-dependent manner. A linear relationship was found between GPx activity and irradiation dose in 0.1-1 Gy group, and GPx was a suitable biomarker for gamma irradiation in the dose range from 0.1 to 1 Gy. Furthermore, the activities of SOD, CAT, GR and GPx of the zebrafish embryos at stage 3 were found to be much higher than those at other stages, indicating that the zebrafish embryos at stage 3 had a greater ability to protect against gamma rays than those at other stages, and thus the activities of antioxidant enzymes changed in a developmental stage-dependent manner.

  2. Ion irradiation induced evolution of nanostructure in a graded multi-trilayer system

    NASA Astrophysics Data System (ADS)

    Roy, Sumalay; Ghatak, J.; Dev, B. N.

    2012-02-01

    Nanostructural modifications in a double-graded Pt/Ni/C multi-trilayer, due to irradiation by an energetic ion-beam, have been analyzed using X-ray reflectivity (XRR), X-ray standing wave (XSW) and cross-sectional transmission electron microscopy (X-TEM) techniques. 2 MeV Au2+ ions were rastered on Pt/Ni/C multi-trilayer samples producing a uniformly irradiated area at ion-fluences ranging from 1 × 1014 ions/cm2 to 2 × 1015 ions/cm2. Ion irradiation induced modifications of microstructural parameters, e.g., layer thicknesses and electron densities of individual layers and interface roughnesses have been obtained from XRR analysis. Pt- and Ni-fluorescence yield from the as-deposited sample under the XSW condition show the distinct existence of Pt and Ni layers. The almost indistinguishable Pt- and Ni-fluorescence data over the first order Bragg peak from the sample irradiated at the highest ion-fluence, suggest complete mixing of Pt and Ni. Strong mixing between Pt and Ni in the ion irradiated samples is also corroborated by XRR results. X-TEM studies reveal the individual layer structure in the as-deposited sample. This layer structure is lost in the sample irradiated at the highest ion fluence indicating a complete mixing between Pt and Ni layers and nanoscale grain growth of Pt-Ni alloys. Additionally, formation of Pt-Ni alloy nano-clusters in the C-layers is observed. The results are understood in the light of the positive heat of mixing between Pt and C, and Ni and C and the negative heat of mixing between Pt and Ni. The effect of heat of mixing becomes dominant at high fluence irradiation.

  3. Biochemical and topological analysis of bovine sperm cells induced by low power laser irradiation

    NASA Astrophysics Data System (ADS)

    Dreyer, T. R.; Siqueira, A. F. P.; Magrini, T. D.; Fiorito, P. A.; Assumpção, M. E. O. A.; Nichi, M.; Martinho, H. S.; Milazzotto, M. P.

    2011-07-01

    Low-level laser irradiation (LLLI) increases ATP production and energy supply to the cell which could increase sperm motility, acrossomal reaction and consequently the fertilizing potential. The aim of this study was to characterize the biochemical and topological changes induced by low power laser irradiation on bull sperm cells. Post-thawing sperm were irradiated with a 633nm laser with fluence rates of 30, 150 and 300mJ.cm-2 (power of 5mW for 1, 5 and 10minutes, respectively); 45, 230, and 450mJ.cm-2 (7.5mW for 1, 5 and 10 minutes); and 60, 300 and 600mJ.cm-2 (10mW for 1, 5 and 10 minutes). Biochemical and metabolical changes were analyzed by FTIR and flow cytometry; oxygen reactive species production was assessed by TBARS and the morphological changes were evaluated by AFM. Motility had no difference among times or powers of irradiation. Increasing in ROS generation was observed with power of 5mW compared to 7.5 and 10mW, and with 10min of irradiation in comparison with 5 and 1min of irradiation. This higher ROS generation was related to an increase in acrossomal and plasma membrane damage. FTIR results showed that the amount of lipids was inversely proportional to the quantity of ROS generated. AFM images showed morphological differences in plasma/acrossomal membrane, mainly on the equatorial region. We conclude that LLLI is an effective method to induce changes on sperm cell metabolism but more studies are necessary to establish an optimal dose to increase the fertility potential of these cells.

  4. Proton irradiation induced defects in GaN: Rutherford backscattering and thermally stimulated current studies

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Nishikata, N.; Kamioka, K.; Kuriyama, K.; Kushida, K.

    2016-03-01

    The proton irradiation induced defects in GaN are studied by combining elastic recoil detection analysis (ERDA), thermally stimulated current (TSC), and Rutherford backscattering spectroscopy (RBS) measurements. The proton irradiation (peak concentration: 1.0 × 1015 cm-2) into GaN films with a thickness of 3 μm is performed using a 500 keV implanter. The proton concentration by a TRIM simulation is maximum at 3600 nm in depth, which means that the proton beam almost passes through the GaN film. The carrier concentration decreases three orders of magnitude to 1015 cm-3 by the proton irradiation, suggesting the existence of the proton irradiation-induced defects. The ERDA measurements using the 1.5 MeV helium beam can evaluate hydrogen from the surface to ∼300 nm. The hydrogen concentration at ∼220 nm is ∼8.3 × 1013 cm-2 and ∼1.0 × 1014 cm-2 for un-irradiated and as-irradiated samples, respectively, suggesting that electrical properties are almost not affected by hydrogen. TSC measurements show a broad spectrum at around 110 K which can be divided into three traps, P1 (ionization energy 173 meV), P2 (251 meV), and P3 (330 meV). The peak intensity of P1 is much larger than that of P2 and P3. These traps are related to the N vacancy and/or complex involving N vacancy (P1), neutral Ga vacancy (VGa) (P2), and complex involving VGa (P3). The Ga displacement concentration evaluated by RBS measurements is 1.75 × 1019 cm-3 corresponding to 1/1000 of the Ga concentration in GaN. The observed Ga displacement may be origins of P2 and P3 traps.

  5. Structural modifications induced by ion irradiation and temperature in boron carbide B4C

    NASA Astrophysics Data System (ADS)

    Victor, G.; Pipon, Y.; Bérerd, N.; Toulhoat, N.; Moncoffre, N.; Djourelov, N.; Miro, S.; Baillet, J.; Pradeilles, N.; Rapaud, O.; Maître, A.; Gosset, D.

    2015-12-01

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B4C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B4C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (Se ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B4C structure under irradiation.

  6. Light-induced fading of the PSL signal from irradiated herbs and spices

    NASA Astrophysics Data System (ADS)

    Alberti, A.; Corda, U.; Fuochi, P.; Bortolin, E.; Calicchia, A.; Onori, S.

    2007-08-01

    Reliability of the photo-stimulated luminescence (PSL) technique, as screening method for irradiated food identification, has been tested with three kinds of herbs and spices (oregano, red pepper and fennel), prepared in two different ways (granular: i.e. seeds and flakes, or powdered), over a long period of storage with different light exposures. The irradiated samples kept in the dark gave always a positive response (the sample is correctly classified as "irradiated") for the overall examination period. The samples kept under ambient light conditions, in typical commercial glass containers, exhibited a reduction of the PSL signal, more or less pronounced depending on the type of food and packaging. The different PSL response of the irradiated samples is to be related to the quantity and quality of the mineral debris present in the individual food. It was also found that, for the same type of food, the light-induced fading was much stronger for the flaked and seed samples than for the corresponding powder samples, the penetrating capability of light being much more inhibited in powdered than in whole seeds or flaked form samples. The observed light bleaching of the PSL signal in irradiated herbs and spices is of practical relevance since it may lead to false negative classifications.

  7. Hesperidin methyl chalcone inhibits oxidative stress and inflammation in a mouse model of ultraviolet B irradiation-induced skin damage.

    PubMed

    Martinez, Renata M; Pinho-Ribeiro, Felipe A; Steffen, Vinicius S; Caviglione, Carla V; Vignoli, Josiane A; Baracat, Marcela M; Georgetti, Sandra R; Verri, Waldiceu A; Casagrande, Rubia

    2015-07-01

    Hesperidin methyl chalcone (HMC) is a safe flavonoid used to treat chronic venous diseases, but its effects and mechanisms on UVB irradiation-induced inflammation and oxidative stress have never been described in vivo. Thus, the purpose of this study was to evaluate the effects of systemic administration of HMC in skin oxidative stress and inflammation induced by UVB irradiation. To induce skin damage, hairless mice were exposed to an acute UVB irradiation dose of 4.14 J/cm(2), and the dorsal skin samples were collected to evaluate oxidative stress and inflammatory response. The intraperitoneal treatment with HMC at the dose of 300 mg/kg inhibited UVB irradiation-induced skin edema, neutrophil recruitment, and matrix metalloproteinase-9 activity. HMC also protected the skin from UVB irradiation-induced oxidative stress by maintaining ferric reducing antioxidant power (FRAP), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) scavenging ability and antioxidant levels (reduced glutathione and catalase). Corroborating, HMC inhibited UVB irradiation-induced superoxide anion generation and gp91phox (NADPH oxidase subunit) mRNA expression. Furthermore, the antioxidant effect of HMC resulted in lower production of inflammatory mediators, including lipid hydroperoxides and a wide range of cytokines. Taken together, these results unveil a novel applicability of HMC in the treatment of UVB irradiation-induced skin inflammation and oxidative stress.

  8. EPR spectra induced by gamma-irradiation of some dry medical herbs

    NASA Astrophysics Data System (ADS)

    Yordanov, N. D.; Lagunov, O.; Dimov, K.

    2009-04-01

    The radiation-induced EPR spectra in some medical herbs are reported. The samples studied are: (i) leaves of nettle, common balm, peppermint and thyme; (ii) stalks of common balm, thyme, milfoil, yarrow and marigold; (iii) blossoms of yarrow and marigold; (iv) blossoms and leaves of hawthorn and tutsan; and (v) roots of common valerian, nettle, elecampane (black and white), restharrows and carlina. Before irradiation all samples exhibit one weak anisotropic singlet EPR line with effective g-value of 2.0050±0.0002. The radiation-induced spectra fall into three groups. EPR spectra of irradiated blossoms of yarrow and marigold, stalks of common balm, thyme, tutsan and yarrow as well as roots of common valerian, nettle and elecampane (black and white) show "cellulose-like" EPR spectrum typical for irradiated plants. It is characterized by one intense central line with g=2.0050±0.0005 and two weak satellite lines situated ca. 30 G left and right to it. EPR spectra of gamma-irradiated restharrows and carlina are complex. They may be represented by one triplet corresponding to the "cellulose-like" EPR spectrum, one relatively intense singlet, situated in the center of the spectrum, and five weak additional satellite lines left and right to the center. The last spectrum was assigned as "carbohydrate-like" type. Only one intense EPR singlet with g=2.0048±0.0005 was recorded after irradiation of leaves of nettle and common balm. The lifetime of the radiation-induced EPR spectra was followed for a period of 3 months.

  9. A Mouse Ear Model for Bystander Studies Induced by Microbeam Irradiation.

    PubMed

    Buonanno, M; Randers-Pehrson, G; Smilenov, L B; Kleiman, N J; Young, E; Ponnayia, B; Brenner, D J

    2015-08-01

    Radiation-induced bystander effects have been observed in vitro and in cell and tissue culture models, however, there are few reported studies showing these effects in vivo. To our knowledge, this is the first reported study on bystander effects induced by microbeam irradiation in an intact living mammal. The mouse ear was used to investigate radiation-induced bystander effects in keratinocytes, utilizing a 3 MeV proton microbeam (LET 13.1 keV/μm) with a range in skin of about 135 μm. Using a custom-designed holder, the ear of an anesthetized C57BL/6J mouse was flattened by gentle suction and placed over the microbeam port to irradiate cells along a 35 μm wide, 6 mm long path. Immunohistochemical analysis of γ-H2AX foci formation in tissue sections revealed, compared to control tissue, proton-induced γ-H2AX foci formation in one of the two epidermal layers of the mouse ear. Strikingly, a higher number of cells than expected showed foci from direct irradiation effects. Although the proton-irradiated line was ~35 μm wide, the average width spanned by γ-H2AX-positive cells exceeded 150 μm. Cells adjacent to or in the epidermal layer opposite the γ-H2AX-positive region did not exhibit foci. These findings validate this mammalian model as a viable system for investigating radiation-induced bystander effects in an intact living organism.

  10. Uranium-induced sensory alterations in the zebrafish Danio rerio.

    PubMed

    Faucher, K; Floriani, M; Gilbin, R; Adam-Guillermin, C

    2012-11-15

    The effect of chronic exposure to uranium ions (UO(2)(2+)) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 μg l(-1) for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes>olfactory bulbs>skin>muscles>brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.

  11. Targeted Cytoplasmic Irradiation with Alpha Particles Induces Mutations in Mammalian Cells

    NASA Astrophysics Data System (ADS)

    Wu, Li-Jun; Randers-Pehrson, Gerhard; Xu, An; Waldren, Charles A.; Geard, Charles R.; Yu, Zengliang; Hei, Tom K.

    1999-04-01

    Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human-hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.

  12. UV-induced self-aggregation of E. coli after low and medium pressure ultraviolet irradiation.

    PubMed

    Kollu, Kerim; Örmeci, Banu

    2015-07-01

    Presence of aggregated bacteria has been shown to decrease the efficacy of ultraviolet (UV) disinfection and there is some indication that UV irradiation may promote aggregation of bacteria among themselves. This study aims to provide an in-depth understanding of the effect of UV light on inducing self-aggregation of Escherichia coli bacteria by using microscopy and particle counter analysis techniques. The bacteria were observed and quantified before and after UV irradiation by employing size and concentration parameters. Four doses of low-pressure (LP) UV irradiation, 20, 40, 60 and 80 mJ/cm(2), and two doses of medium-pressure (MP) UV irradiation, 40 and 80 mJ/cm(2), were tested. At all LP UV doses tested, a significant increase in particle size was observed following UV exposure, indicating UV-induced self-aggregation. However, the magnitude of UV dose did not seem to have an impact. In the MP UV experiments, only a dose of 80 mJ/cm(2) had a significant impact on the formation of aggregates upon UV exposure. Changing the light intensity and exposure time to deliver the same LP UV dose resulted in different levels of aggregation. The results indicated that UV light intensity and wavelength may play a role in aggregation of bacteria.

  13. Ion irradiation induced nanocrystal formation in amorphous Zr 55Cu 30Al 10Ni 5 alloy

    NASA Astrophysics Data System (ADS)

    Carter, Jesse; Fu, E. G.; Martin, Michael; Xie, Guoqiang; Zhang, X.; Wang, Y. Q.; Wijesundera, D.; Wang, X. M.; Chu, Wei-Kan; McDeavitt, Sean M.; Shao, Lin

    2009-09-01

    Ion irradiation can be used to induce partial crystallization in metallic glasses to improve their surface properties. We investigated the microstructural changes in ribbon Zr 55Cu 30Al 10Ni 5 metallic glass after 1 MeV Cu-ion irradiation at room temperature, to a fluence of 1.0 × 10 16 cm -2. In contrast to a recent report by others that there was no irradiation induced crystallization in the same alloy [S. Nagata, S. Higashi, B. Tsuchiya, K. Toh, T. Shikama, K. Takahiro, K. Ozaki, K. Kawatusra, S. Yamamoto, A. Inouye, Nucl. Instr. and Meth. B 257 (2007) 420], we have observed nanocrystals in the as-irradiated samples. Two groups of nanocrystals, one with diameters of 5-10 nm and another with diameters of 50-100 nm are observed by using high resolution transmission electron microscopy. Experimentally measured planar spacings ( d-values) agree with the expectations for Cu 10Zr 7, NiZr 2 and CuZr 2 phases. We further discussed the possibility to form a substitutional intermetallic (Ni xCu 1-x)Zr 2 phase.

  14. Systemic modulation by ultraviolet irradiation of cutaneous N-methyl-N'-nitro-N-nitrosoguanidine-induced carcinogenesis.

    PubMed

    Gensler, H L

    1992-01-10

    Ultraviolet irradiation can systemically enhance subsequent skin cancer induction by benzo[a]pyrene, methylcholanthrene, or UV radiation. The present study was designed to determine whether UVB irradiation influences host susceptibility to the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Female C3H/HeJ mice were exposed dorsally to UVB radiation from banks of 6 Westinghouse FS40 sun lamps. The mice received a total UV dose of approximately 8.1 x 10(5) J m-2 over a 15-week period. After termination of UVB treatments, ventral tumors were induced by 4 applications of 30 mumol of MNNG at 8-day intervals. At 20 weeks after the first MNNG treatment, UVB-irradiated mice had 7-fold more MNNG-induced, ventral tumors than did the unirradiated control mice (P = 0.026, Wilcoxon rank sum test). Ventral application of MNNG after cessation of dorsal UVB exposure, but before UV tumor appearance, did not influence photocarcinogenesis. These results demonstrate that UV irradiation can systemically decrease host resistance to tumor induction by the methylating agent, MNNG.

  15. Localization of pellicle-induced open contacts using Charge-Induced Voltage Alteration

    SciTech Connect

    Cole, E.I. Jr.; Soden, J.M.

    1993-08-01

    The recently developed Charge-Induced Voltage Alteration (CIVA) technique for localizing open metal conductors was used successfully to identify transistors with electrically open metal-1 contacts to silicon. The transistors were in the I/O port circuitry of a failing microcontroller and were completely covered by a metal-2 power bus. The root cause of the open contacts was a subtle scratch in the pellicle over the contact reticle. The scratch prevented full exposure of the photoresist, resulting in incomplete removal of the interlevel oxide in several contact windows. In addition to this powerful new application of CIVA, a number of failure analysis techniques utilizing both the electrical and physical properties of the failing microcontrollers were employed to identify and confirm the open contacts. These techniques are reviewed and recommendations are given for improved pellicle/reticle inspection.

  16. Nickel-induced heritable alterations in retroviral transforming gene expression.

    PubMed Central

    Biggart, N W; Gallick, G E; Murphy, E C

    1987-01-01

    Determination of the mutagenic effects of carcinogenic nickel compounds has been difficult because, like many metals, nickel is poorly or nonmutagenic in procaryotic mutagenicity assays. We attempted to characterize nickel-induced genetic lesions by assessing the effect of nickel chloride on the conditionally defective expression of the v-mos transforming gene in normal rat kidney cells infected with the Murine sarcoma virus mutant ts110 (MuSVts110) retrovirus. MuSVts110 contains an out-of-frame gag gene-mos gene junction that prevents the expression of the v-mos gene at the nonpermissive temperature (39 degrees C). In MuSVts110-infected cells (6m2 cells) grown at 33 degrees C, however, this defect can be suppressed by a splicing event that restores the mos reading frame, allowing the expression of a gag-mos fusion protein which induces the transformed phenotype. The capacity to splice the viral transcript at 33 degrees C, but not at 39 degrees C, is an intrinsic property of the viral RNA. This property allowed us to target the MuSVts110 genome using a positive selection scheme whereby nickel was used to induce genetic changes which resulted in expression of the transformed phenotype at 39 degrees C. We treated 6m2 cells with NiCl2 and isolated foci consisting of cells which had reverted to the transformed phenotype at 39 degrees C. We found that brief nickel treatment increased the reversion frequency of 6m2 cells grown at 39 degrees C sevenfold over the spontaneous reversion frequency. The nickel-induced revertants displayed the following heritable characteristics: They stably maintained the transformed phenotype at 39 degrees C; unlike the MuSVts110 RNA in 6m2 cells, the nickel-induced revertant viral RNA could be spliced efficiently at 39 degrees C; as a consequence of the enhanced accumulation of spliced viral RNA, the nickel-induced revertants produced substantial amounts of the transforming v-mos protein P85gag-mos at 39 degrees C; the nickel-induced

  17. Radiation cataractogenesis induced by neutron or gamma irradiation in the rat lens is reduced by vitamin E

    SciTech Connect

    Ross, W.M.; Creighton, M.O.; Trevithick, J.R. )

    1990-09-01

    Although cataract of the eye lens is a known late effect of ionizing radiation exposure, most of the experimental work to date has concentrated on single, acute high doses or multiple, fractionated, chronic exposures. Many papers have dealt with biochemical alterations in metabolism and cellular components, with microscopic and electron microscopic lesions to the epithelial and cortical layers, and with clinical cataract formation. However, the minimum cataractogenic dose for rats has for many years been considered to be about 2 Gy for a single, acute dose of low LET radiation. Our purpose in designing this pilot study was three fold: firstly, to determine whether any physical damage could be detected after low, acute exposure to neutron radiation (10 and 100 cGy); secondly, to compare the relative effectiveness of fast (14 MeV) neutrons with gamma-rays; and thirdly, to investigate the possibility that vitamin E could protect the lenses from radiation damage. The results revealed that morphological damage was already discernible within minutes after exposure to neutrons or gamma-rays, that it became greater after 24 hours, that neutrons were more damaging than gamma-rays, and that vitamin E could effectively reduce the cataractogenic damage induced by ionizing radiation. Control, non-irradiated lenses with or without vitamin E, either in vivo or in vitro, showed no damage. Also, it appeared that in vitro irradiation was more damaging to lenses than in vivo irradiation, so this culture technique may prove to be a sensitive tool for assessing early damage caused by ionizing radiation.

  18. Alterations in glucose kinetics induced by pentobarbital anesthesia

    SciTech Connect

    Lang, C.H.; Bagby, G.J.; Spitzer, J.J.

    1986-03-05

    Pentobarbital is a common anesthetic agent used in animal research that is known to alter sympathetic function and may also affect carbohydrate metabolism. The in vivo effects of iv pentobarbital on glucose homeostasis were studied in chronically catheterized fasted rats. Whole body glucose kinetics, assessed by the constant iv infusion of (6-/sup 3/H)- and (U-/sup 14/C)-glucose, were determined in all rats in the conscious state. Thereafter, glucose metabolism was followed over the next 4 hr in 3 subgroups of rats; conscious, anesthetized with body temperature maintained, and anesthetized with body temperature not maintained. Hypothermia (a 5/sup 0/C decrease) developed spontaneously in anesthetized rats kept at ambient temperature (22/sup 0/C). No differences were seen in MABP and heart rate between conscious and normothermic anesthetized rats; however, hypothermic anesthetized rats showed a decrease in MABP (20%) and heart rate (35%). Likewise, plasma glucose and lactate concentrations, the rate of glucose appearance (Ra), recycling and metabolic clearance (MCR) did not differ between conscious and normothermic anesthetized animals. In contrast, hypothermic anesthetized rats showed a 50% reduction in plasma lactate, a 40% drop in glucose Ra, and a 30-40% decrease in glucose recycling and MCR. Thus, pentobarbital does not appear to alter in vivo glucose kinetics, compared to unanesthetized controls, provided that body temperature is maintained.

  19. Alcohol induced alterations to the human fecal VOC metabolome.

    PubMed

    Couch, Robin D; Dailey, Allyson; Zaidi, Fatima; Navarro, Karl; Forsyth, Christopher B; Mutlu, Ece; Engen, Phillip A; Keshavarzian, Ali

    2015-01-01

    Studies have shown that excessive alcohol consumption impacts the intestinal microbiota composition, causing disruption of homeostasis (dysbiosis). However, this observed change is not indicative of the dysbiotic intestinal microbiota function that could result in the production of injurious and toxic products. Thus, knowledge of the effects of alcohol on the intestinal microbiota function and their metabolites is warranted, in order to better understand the role of the intestinal microbiota in alcohol associated organ failure. Here, we report the results of a differential metabolomic analysis comparing volatile organic compounds (VOC) detected in the stool of alcoholics and non-alcoholic healthy controls. We performed the analysis with fecal samples collected after passage as well as with samples collected directly from the sigmoid lumen. Regardless of the approach to fecal collection, we found a stool VOC metabolomic signature in alcoholics that is different from healthy controls. The most notable metabolite alterations in the alcoholic samples include: (1) an elevation in the oxidative stress biomarker tetradecane; (2) a decrease in five fatty alcohols with anti-oxidant property; (3) a decrease in the short chain fatty acids propionate and isobutyrate, important in maintaining intestinal epithelial cell health and barrier integrity; (4) a decrease in alcohol consumption natural suppressant caryophyllene; (5) a decrease in natural product and hepatic steatosis attenuator camphene; and (6) decreased dimethyl disulfide and dimethyl trisulfide, microbial products of decomposition. Our results showed that intestinal microbiota function is altered in alcoholics which might promote alcohol associated pathologies.

  20. Altered brain energetics induces mitochondrial fission arrest in Alzheimer's Disease.

    PubMed

    Zhang, Liang; Trushin, Sergey; Christensen, Trace A; Bachmeier, Benjamin V; Gateno, Benjamin; Schroeder, Andreas; Yao, Jia; Itoh, Kie; Sesaki, Hiromi; Poon, Wayne W; Gylys, Karen H; Patterson, Emily R; Parisi, Joseph E; Diaz Brinton, Roberta; Salisbury, Jeffrey L; Trushina, Eugenia

    2016-01-05

    Altered brain metabolism is associated with progression of Alzheimer's Disease (AD). Mitochondria respond to bioenergetic changes by continuous fission and fusion. To account for three dimensional architecture of the brain tissue and organelles, we applied 3-dimensional electron microscopy (3D EM) reconstruction to visualize mitochondrial structure in the brain tissue from patients and mouse models of AD. We identified a previously unknown mitochondrial fission arrest phenotype that results in elongated interconnected organelles, "mitochondria-on-a-string" (MOAS). Our data suggest that MOAS formation may occur at the final stages of fission process and was not associated with altered translocation of activated dynamin related protein 1 (Drp1) to mitochondria but with reduced GTPase activity. Since MOAS formation was also observed in the brain tissue of wild-type mice in response to hypoxia or during chronological aging, fission arrest may represent fundamental compensatory adaptation to bioenergetic stress providing protection against mitophagy that may preserve residual mitochondrial function. The discovery of novel mitochondrial phenotype that occurs in the brain tissue in response to energetic stress accurately detected only using 3D EM reconstruction argues for a major role of mitochondrial dynamics in regulating neuronal survival.

  1. Alcohol Induced Alterations to the Human Fecal VOC Metabolome

    PubMed Central

    Couch, Robin D.; Dailey, Allyson; Zaidi, Fatima; Navarro, Karl; Forsyth, Christopher B.; Mutlu, Ece; Engen, Phillip A.; Keshavarzian, Ali

    2015-01-01

    Studies have shown that excessive alcohol consumption impacts the intestinal microbiota composition, causing disruption of homeostasis (dysbiosis). However, this observed change is not indicative of the dysbiotic intestinal microbiota function that could result in the production of injurious and toxic products. Thus, knowledge of the effects of alcohol on the intestinal microbiota function and their metabolites is warranted, in order to better understand the role of the intestinal microbiota in alcohol associated organ failure. Here, we report the results of a differential metabolomic analysis comparing volatile organic compounds (VOC) detected in the stool of alcoholics and non-alcoholic healthy controls. We performed the analysis with fecal samples collected after passage as well as with samples collected directly from the sigmoid lumen. Regardless of the approach to fecal collection, we found a stool VOC metabolomic signature in alcoholics that is different from healthy controls. The most notable metabolite alterations in the alcoholic samples include: (1) an elevation in the oxidative stress biomarker tetradecane; (2) a decrease in five fatty alcohols with anti-oxidant property; (3) a decrease in the short chain fatty acids propionate and isobutyrate, important in maintaining intestinal epithelial cell health and barrier integrity; (4) a decrease in alcohol consumption natural suppressant caryophyllene; (5) a decrease in natural product and hepatic steatosis attenuator camphene; and (6) decreased dimethyl disulfide and dimethyl trisulfide, microbial products of decomposition. Our results showed that intestinal microbiota function is altered in alcoholics which might promote alcohol associated pathologies. PMID:25751150

  2. Change in Ion Beam Induced Current from Si Metal-Oxide-Semiconductor Capacitors after Gamma-Ray Irradiation

    SciTech Connect

    Ohshima, T.; Onoda, S.; Hirao, T.; Takahashi, Y.; Vizkelethy, G.; Doyle, B. L.

    2009-03-10

    To investigate the effects of gamma-ray irradiation on transient current induced in MOS capacitors by heavy ion incidence, Si MOS capacitors were irradiated with gamma-rays up to 60.9 kGy(SiO2). The change in Transient Ion Beam Induced Current (TIBIC) signals due to gamma-ray irradiation was investigated using 15 MeV-oxygen ion microbeams. After gamma-ray irradiation, the peak current of the TIBIC signal vs. bias voltage curve shifted toward negative voltages. This shift can be interpreted in terms of the charge trapped in the oxide. In this dose range, no significant effects of the interface traps induced by gamma-ray irradiation on the TIBIC signals were observed.

  3. Single-Limb Irradiation Induces Local and Systemic Bone Loss in a Murine Model.

    PubMed

    Wright, Laura E; Buijs, Jeroen T; Kim, Hun-Soo; Coats, Laura E; Scheidler, Anne M; John, Sutha K; She, Yun; Murthy, Sreemala; Ma, Ning; Chin-Sinex, Helen J; Bellido, Teresita M; Bateman, Ted A; Mendonca, Marc S; Mohammad, Khalid S; Guise, Theresa A

    2015-07-01

    Increased fracture risk is commonly reported in cancer patients receiving radiotherapy, particularly at sites within the field of treatment. The direct and systemic effects of ionizing radiation on bone at a therapeutic dose are not well-characterized in clinically relevant animal models. Using 20-week-old male C57Bl/6 mice, effects of irradiation (right hindlimb; 2 Gy) on bone volume and microarchitecture were evaluated prospectively by microcomputed tomography and histomorphometry and compared to contralateral-shielded bone (left hindlimb) and non-irradiated control bone. One week postirradiation, trabecular bone volume declined in irradiated tibias (-22%; p < 0.0001) and femurs (-14%; p = 0.0586) and microarchitectural parameters were compromised. Trabecular bone volume declined in contralateral tibias (-17%; p = 0.003), and no loss was detected at the femur. Osteoclast number, apoptotic osteocyte number, and marrow adiposity were increased in irradiated bone relative to contralateral and non-irradiated bone, whereas osteoblast number was unchanged. Despite no change in osteoblast number 1 week postirradiation, dynamic bone formation indices revealed a reduction in mineralized bone surface and a concomitant increase in unmineralized osteoid surface area in irradiated bone relative to contralateral and non-irradiated control bone. Further, dose-dependent and time-dependent calvarial culture and in vitro assays confirmed that calvarial osteoblasts and osteoblast-like MC3T3 cells were relatively radioresistant, whereas calvarial osteocyte and osteocyte-like MLO-Y4 cell apoptosis was induced as early as 48 hours postirradiation (4 Gy). In osteoclastogenesis assays, radiation exposure (8 Gy) stimulated murine macrophage RAW264.7 cell differentiation, and coculture of irradiated RAW264.7 cells with MLO-Y4 or murine bone marrow cells enhanced this effect. These studies highlight the multifaceted nature of radiation-induced bone loss by demonstrating direct

  4. Measurement of Irradiated Pyroprocessing Samples via Laser Induced Breakdown Spectroscopy

    SciTech Connect

    Phongikaroon, Supathorn

    2016-10-31

    The primary objective of this research is to develop an applied technology and provide an assessment to remotely measure and analyze the real time or near real time concentrations of used nuclear fuel (UNF) dissolute in electrorefiners. Here, Laser-Induced Breakdown Spectroscopy (LIBS), in UNF pyroprocessing facilities will be investigated. LIBS is an elemental analysis method, which is based on the emission from plasma generated by focusing a laser beam into the medium. This technology has been reported to be applicable in the media of solids, liquids (includes molten metals), and gases for detecting elements of special nuclear materials. The advantages of applying the technology for pyroprocessing facilities are: (i) Rapid real-time elemental analysis|one measurement/laser pulse, or average spectra from multiple laser pulses for greater accuracy in < 2 minutes; (ii) Direct detection of elements and impurities in the system with low detection limits|element specific, ranging from 2-1000 ppm for most elements; and (iii) Near non-destructive elemental analysis method (about 1 g material). One important challenge to overcome is achieving high-resolution spectral analysis to quantitatively analyze all important fission products and actinides. Another important challenge is related to accessibility of molten salt, which is heated in a heavily insulated, remotely operated furnace in a high radiation environment with an argon atmosphere.

  5. Low molecular weight heparin restores antithrombin III activity from hyperglycemia induced alterations.

    PubMed

    Ceriello, A; Marchi, E; Palazzni, E; Quatraro, A; Giugliano, D

    1990-01-01

    Alteration of antithrombin III (ATIII) activity, glycemia level dependent, exists in diabetes mellitus. In this study the ability of a low molecular weight heparin (LMWH) (Fluxum, Alfa-Wassermann S.p.A., Bologna, Italy), as well as unfractioned héparin, to preserve ATIII activity from glucose-induced alterations, both in vitro and in vivo, is reported. The subcutaneous and intravenous LMWH and heparin administration increases basal depressed ATIII activity in diabetic patients. Heparin shows an equivalent effect on both anti-IIa and anti-Xa activity of ATIII, while LMWH is more effective in preserving the anti-Xa activity. Similarity, heparin preserves ATIII activity from hyperglycemia-induced alterations, during hyperglycemic clamp, and LMWH infusion is able to preserve a significant amount of anti-Xa activity from glucose-induced alterations. Since diabetic patients show a high incidence of thrombotic accidents, LMWH appears to be a promising innovation for the prevention of diabetic thrombophylia.

  6. Identification of altered metabolic pathways of γ-irradiated rice mutant via network-based transcriptome analysis.

    PubMed

    Hwang, Sun-Goo; Kim, Dong Sub; Hwang, Jung Eun; Park, Hyeon Mi; Jang, Cheol Seong

    2015-12-01

    In order to develop rice mutants for crop improvement, we applied γ-irradiation mutagenesis and selected a rice seed color mutant (MT) in the M14 targeting-induced local lesions in genome lines. This mutant exhibited differences in germination rate, plant height, and root length in seedlings compared to the wild-type plants. We found 1645 different expressed probes of MT by microarray hybridization. To identify the modified metabolic pathways, we conducted integrated genomic analysis such as weighted correlation network analysis with a module detection method of differentially expressed genes (DEGs) in MT on the basis of large-scale microarray transcriptional profiling. These modules are largely divided into three subnetworks and mainly exhibit overrepresented gene ontology functions such as oxidation-related function, ion-binding, and kinase activity (phosphorylation), and the expressional coherences of module genes mainly exhibited in vegetative and maturation stages. Through a metabolic pathway analysis, we detected the significant DEGs involved in the major carbohydrate metabolism (starch degradation), protein degradation (aspartate protease), and signaling in sugars and nutrients. Furthermore, the accumulation of amino acids (asparagine and glutamic acid), sucrose, and starch in MT were affected by gamma rays. Our results provide an effective approach for identification of metabolic pathways associated with useful agronomic traits in mutation breeding.

  7. Altered microRNA expression patterns in irradiated hematopoietic tissues suggest a sex-specific protective mechanism

    SciTech Connect

    Ilnytskyy, Yaroslav; Zemp, Franz J.; Koturbash, Igor; Kovalchuk, Olga

    2008-12-05

    To investigate involvement of miRNAs in radiation responses we used microRNAome profiling to analyze the sex-specific response of radiation sensitive hematopoietic lymphoid tissues. We show that radiation exposure resulted in a significant and sex-specific deregulation of microRNA expression in murine spleen and thymus tissues. Among the regulated miRNAs, we found that changes in expression of miR-34a and miR-7 may be involved in important protective mechanisms counteracting radiation cytotoxicity. We observed a significant increase in the expression of tumor-suppressor miR-34a, paralleled by a decrease in the expression of its target oncogenes NOTCH1, MYC, E2F3 and cyclin D1. Additionally, we show that miR-7 targets the lymphoid-specific helicase LSH, a pivotal regulator of DNA methylation and genome stability. While miR-7 was significantly down-regulated LSH was significantly up-regulated. These cellular changes may constitute an attempt to counteract radiation-induced hypomethylation. Tissue specificity of miRNA responses and possible regulation of miRNA expression upon irradiation are discussed.

  8. Alcohol-induced alterations in dopamine modulation of prefrontal activity.

    PubMed

    Trantham-Davidson, Heather; Chandler, L Judson

    2015-12-01

    Long-term alcohol use leads to persistent cognitive deficits that may be associated with maladaptive changes in the neurocircuitry that mediates executive functions. Impairments caused by these changes can persist well into abstinence and have a negative impact on quality of life and job performance, and can increase the probability of relapse. Many of the changes that affect cognitive function appear to involve dysregulation of the mesocortical dopamine system. This includes changes in dopamine release and alterations in dopamine receptor expression and function in the medial prefrontal cortex (PFC). This review summarizes the cellular effects of acute and chronic ethanol exposure on dopamine release and dopamine receptor function in the PFC with the goal of providing greater understanding of the effects of alcohol-use disorders on the dopamine system and how this relates to deficits in the executive function of the PFC.

  9. Alcohol-induced alterations in dopamine modulation of prefrontal activity

    PubMed Central

    Trantham-Davidson, Heather; Chandler, L. Judson

    2015-01-01

    Long-term alcohol use leads to persistent cognitive deficits that may be associated with maladaptive changes in the neurocircuitry that mediates executive functions. Impairments caused by these changes can persist well into abstinence and have a negative impact on quality of life and job performance, and can increase the probability of relapse. Many of the changes that affect cognitive function appear to involve dysregulation of the mesocortical dopamine system. This includes changes in dopamine release and alterations in dopamine receptor expression and function in the medial prefrontal cortex (PFC). This review summarizes the cellular effects of acute and chronic ethanol exposure on dopamine release and dopamine receptor function in the PFC with the goal of providing greater understanding of the effects of alcohol-use disorders on the dopamine system and how this relates to deficits in the executive function of the PFC. PMID:26558348

  10. The alteration of copper homeostasis in inflammation induced by lipopolysaccharides.

    PubMed

    Han, Ming; Lin, Zhexuan; Zhang, Yuan

    2013-08-01

    Significant changes of copper homeostasis were triggered by lipopolysaccharides, which result in systemic inflammatory response and contribute to hepatic injury. Administration of lipopolysaccharides resulted in the increase of plasma "free" copper and total copper concentrations, whereas, the decrease of "free" copper and total copper contents in liver tissue. Copper-associated proteins were detected and showed a down-regulation of X-linked inhibitor of apoptosis protein, and up-regulation of copper metabolism domain containing 1 and copper transporter 1. The alteration of these proteins would lower the apoptotic threshold. Meanwhile, the increasing of circulation copper might cause oxidative injury through Fenton reaction and contribute to tissue injury. Our findings underscored the possibility that these changes in systemic copper homeostasis might provide a novel insight of the characteristic of the acute phase of inflammatory response and the underlying influence on tissue injury.

  11. Hepatoepigenetic Alterations in Viral and Nonviral-Induced Hepatocellular Carcinoma

    PubMed Central

    Setshedi, Mashiko; Hairwadzi, Henry N.

    2016-01-01

    Hepatocellular carcinoma (HCC) is a major public health concern and one of the leading causes of tumour-related deaths worldwide. Extensive evidence endorses that HCC is a multifactorial disease characterised by hepatic cirrhosis mostly associated with chronic inflammation and hepatitis B/C viral infections. Interaction of viral products with the host cell machinery may lead to increased frequency of genetic and epigenetic aberrations that cause harmful alterations in gene transcription. This may provide a progressive selective advantage for neoplastic transformation of hepatocytes associated with phenotypic heterogeneity of intratumour HCC cells, thus posing even more challenges in HCC treatment development. Epigenetic aberrations involving DNA methylation, histone modifications, and noncoding miRNA dysregulation have been shown to be intimately linked with and play a critical role in tumour initiation, progression, and metastases. The current review focuses on the aberrant hepatoepigenetics events that play important roles in hepatocarcinogenesis and their utilities in the development of HCC therapy. PMID:28105421

  12. Thiamine deficiency induced neurochemical, neuroanatomical, and neuropsychological alterations: a reappraisal.

    PubMed

    Nardone, Raffaele; Höller, Yvonne; Storti, Monica; Christova, Monica; Tezzon, Frediano; Golaszewski, Stefan; Trinka, Eugen; Brigo, Francesco

    2013-01-01

    Nutritional deficiency can cause, mainly in chronic alcoholic subjects, the Wernicke encephalopathy and its chronic neurological sequela, the Wernicke-Korsakoff syndrome (WKS). Long-term chronic ethanol abuse results in hippocampal and cortical cell loss. Thiamine deficiency also alters principally hippocampal- and frontal cortical-dependent neurochemistry; moreover in WKS patients, important pathological damage to the diencephalon can occur. In fact, the amnesic syndrome typical for WKS is mainly due to the damage in the diencephalic-hippocampal circuitry, including thalamic nuclei and mammillary bodies. The loss of cholinergic cells in the basal forebrain region results in decreased cholinergic input to the hippocampus and the cortex and reduced choline acetyltransferase and acetylcholinesterase activities and function, as well as in acetylcholine receptor downregulation within these brain regions. In this narrative review, we will focus on the neurochemical, neuroanatomical, and neuropsychological studies shedding light on the effects of thiamine deficiency in experimental models and in humans.

  13. Inactivation of AMPKα1 induces asthenozoospermia and alters spermatozoa morphology.

    PubMed

    Tartarin, Pauline; Guibert, Edith; Touré, Aminata; Ouiste, Claire; Leclerc, Jocelyne; Sanz, Nieves; Brière, Sylvain; Dacheux, Jean-Louis; Delaleu, Bernadette; McNeilly, Judith R; McNeilly, Alan S; Brillard, Jean-Pierre; Dupont, Joëlle; Foretz, Marc; Viollet, Benoit; Froment, Pascal

    2012-07-01

    AMP-activated protein kinase (AMPK), a key regulator of cellular energy homeostasis, is present in metabolic tissues (muscle and liver) and has been identified as a modulator of the female reproductive functions. However, its function in the testis has not yet been clearly defined. We have investigated the potential role of AMPK in male reproduction by using transgenic mice lacking the activity of AMPK catalytic subunit α1 gene [α1AMPK knockout (KO)]. In the testis, the α1AMPK subunit is expressed in germ cells and also in somatic cells (Sertoli and Leydig cells). α1AMPK KO male mice show a decrease in fertility, despite no clear alteration in the testis morphology or sperm production. However, in α1AMPK(-/-) mice, we demonstrate that spermatozoa have structural abnormalities and are less motile than in control mice. These spermatozoa alterations are associated with a 50% decrease in mitochondrial activity, a 60% decrease in basal oxygen consumption, and morphological defects. The α1AMPK KO male mice had high androgen levels associated with a 5- and 3-fold increase in intratesticular cholesterol and testosterone concentrations, respectively. High concentrations of proteins involved in steroid production (3β-hydroxysteroid dehydrogenase, cytochrome steroid 17 alpha-hydroxylase/17,20 lysate, and steroidogenic acute regulatory protein) were also detected in α1AMPK(-/-) testes. In the pituitary, the LH and FSH concentrations tended to be lower in α1AMPK(-/-) male mice, probably due to the negative feedback of the high testosterone levels. These results suggest that total α1AMPK deficiency in male mice affects androgen production and quality of spermatozoa, leading to a decrease in fertility.

  14. Altered brain network modules induce helplessness in major depressive disorder

    PubMed Central

    Peng, Daihui; Shi, Feng; Shen, Ting; Peng, Ziwen; Zhang, Chen; Liu, Xiaohua; Qiu, Meihui; Liu, Jun; Jiang, Kaida; Shen, Dinggang

    2017-01-01

    Objective The abnormal brain functional connectivity (FC) has been assumed to be a pathophysiological aspect of major depressive disorder (MDD). However, it is poorly understood, regarding the underlying patterns of global FC network and their relationships with the clinical characteristics of MDD. Methods Resting-state functional magnetic resonance imaging data were acquired from 16 first episode, medication-naïve MDD patients and 16 healthy control subjects. The global FC network was constructed using 90 brain regions. The global topological patterns, e.g., small-worldness and modularity, and their relationships with depressive characteristics were investigated. Furthermore, the participant coefficient and module degree of MDD patients were measured to reflect the regional roles in module network, and the impairment of FC was examined by network based statistic. Results Small-world property was not altered in MDD. However, MDD patients exhibited 5 atypically reorganized modules compared to the controls. A positive relationship was also found among MDD patients between the intra-module I and helplessness factor evaluated via the Hamilton Depression Scale. Specifically, eight regions exhibited the abnormal participant coefficient or module degree, e.g., left superior orbital frontal cortex and right amygdala. The decreased FC was identified among the sub-network of 24 brain regions, e.g., frontal cortex, supplementary motor area, amygdala, thalamus, and hippocampus. Limitation The limited size of MDD samples precluded meaningful study of distinct clinical characteristics in relation to aberrant FC. Conclusions The results revealed altered patterns of brain module network at the global level in MDD patients, which might contribute to the feelings of helplessness. PMID:25033474

  15. Vanadium exposure-induced neurobehavioral alterations among Chinese workers.

    PubMed

    Li, Hong; Zhou, Dinglun; Zhang, Qin; Feng, Chengyong; Zheng, Wei; He, Keping; Lan, Yajia

    2013-05-01

    Vanadium-containing products are manufactured and widely used in the modern industry. Yet the neurobehavioral toxicity due to occupational exposure to vanadium remained elusive. This cross-sectional study was designed to examine the neurotoxic effects of occupational vanadium exposure. A total of 463 vanadium-exposed workers (exposed group) and 251 non-exposed workers (control group) were recruited from a Steel and Iron Group in Sichuan, China. A WHO-recommended neurobehavioral core test battery (NCTB) and event-related auditory evoked potentials test (P300) were used to assess the neurobehavioral functions of all study subjects. A general linear model was used to compare outcome scores between the two groups while controlling for possible confounders. The exposed group showed a statistically significant neurobehavioral alteration more than the control group in the NCTB tests. The exposed workers also exhibited an increased anger-hostility, depression-dejection and fatigue-inertia on the profile of mood states (p<0.05). Performances in the simple reaction time, digit span, benton visual retention and pursuit aiming were also poorer among exposed workers as compared to unexposed control workers (p<0.05). Some of these poor performances in tests were also significantly related to workers' exposure duration. P300 latencies were longer in the exposed group than in the control (p<0.05). Longer mean reaction times and more counting errors were also found in the exposed workers (p<0.05). Given the findings of our study and the limitations of neurobehavioral workplace testing, we found evidence of altered neurobehavioral outcomes by occupational exposure to vanadium.

  16. Detection of some irradiated spices on the basis of radiation induced damage of starch

    NASA Astrophysics Data System (ADS)

    Farkas, J.; Sharif, M. M.; Koncz, Á.

    Untreated and irradiated samples of spices were suspended in water, alkalized, and after heat-gelatinization, the apparent viscosity was determined by a rotational viscometer. Several spices, i.e. white pepper, black pepper, nutmeg and ginger showed considerable loss of viscosity as a function of γ-radiation dose in the dose range required for microbial decontamination of natural spices. Less promising results were obtained with spices such as allspice, garlic powder, and onion powder forming low-viscosity heat-treated suspensions even when unirradiated viscometric studies were also performed with a number of pepper samples of various origin to estimate the "natural" variation of rheological properties. Irradiation and storage studies were performed with ground black pepper samples of moisture contents in equilibrium with air of 25%, 50% and 75% R.H., respectively, either untreated or irradiated with 4, 8, 16 or 32 kGy, to study the effect of equilibrium relative humidity and storage time on detectability of radiation treatment. During the entire storage period of 100 days, statistically significant differences of the apparent viscosities of heat-gelatinized suspensions remained detectable between untreated samples and those irradiated with 8 kGy or higher doses. The apparent viscosity of high-moisture (75% E.R.H.) untreated samples was decreasing during long-term storage. Differences between viscosities of untreated and irradiated samples were enlarged when measured at elevated temperatures such as 50°C in the rotational viscometer, or in the boiling-water bath of a falling number apparatus. Other analytical indices such as onset and peak temperatures of gelatinization endotherms by DSC (damaged starch content), by colorimetry, reducing sugar content, alcohol-induced turbidity of hot water extracts of pepper samples, have been changed less dramatically by irradiation than the apparent viscosity of the gelatinized suspensions

  17. Modulatory effects of new curcumin analogues on gamma-irradiation - Induced nephrotoxicity in rats.

    PubMed

    Ismail, Amel F M; Zaher, Nashwa H; El-Hossary, Ebaa M; El-Gazzar, Marwa G

    2016-12-25

    In the present study, a new series of 2-amino-pyran-3-carbonitrile derivatives of curcumin 2-7 have been synthesized via one-pot simple and efficient protocol, involving the reaction of curcumin 1 with substituted-benzylidene-malononitrile to modify the 1,3-diketone moiety. The structures of the synthesized compounds 2-7 were elucidated by microanalytical and spectral data, which were found consistent with the assigned structures. The nephroprotective mechanism of these new curcumin analogues was evaluated on the post-gamma-irradiation (7 Gy) - induced nephrotoxicity in rats. Activation of Nrf2 by these curcumin analogues is responsible for the amendment of the antioxidant status, impairment of NF-κB signal, thus attenuate the nephrotoxicity induced post-γ-irradiation exposure. 4-Chloro-phenyl curcumin analogue 7 showed the most potent activity. In conclusion, the results of the present study demonstrate a promising role of these new curcumin analogues to attenuate the early symptoms of nephrotoxicity induced by γ-irradiation in rats via activation of Nrf2 gene expression. These new curcumin analogues need further toxicological investigations to assess their therapeutic index.

  18. Irradiation-induced grain growth and defect evolution in nanocrystalline zirconia with doped grain boundaries.

    PubMed

    Dey, Sanchita; Mardinly, John; Wang, Yongqiang; Valdez, James A; Holesinger, Terry G; Uberuaga, Blas P; Ditto, Jeff J; Drazin, John W; Castro, Ricardo H R

    2016-06-22

    Grain boundaries are effective sinks for radiation-induced defects, ultimately impacting the radiation tolerance of nanocrystalline materials (dense materials with nanosized grains) against net defect accumulation. However, irradiation-induced grain growth leads to grain boundary area decrease, shortening potential benefits of nanostructures. A possible approach to mitigate this is the introduction of dopants to target a decrease in grain boundary mobility or a reduction in grain boundary energy to eliminate driving forces for grain growth (using similar strategies as to control thermal growth). Here we tested this concept in nanocrystalline zirconia doped with lanthanum. Although the dopant is observed to segregate to the grain boundaries, causing grain boundary energy decrease and promoting dragging forces for thermally activated boundary movement, irradiation induced grain growth could not be avoided under heavy ion irradiation, suggesting a different growth mechanism as compared to thermal growth. Furthermore, it is apparent that reducing the grain boundary energy reduced the effectiveness of the grain boundary as sinks, and the number of defects in the doped material is higher than in undoped (La-free) YSZ.

  19. Irradiation-induced grain growth and defect evolution in nanocrystalline zirconia with doped grain boundaries

    DOE PAGES

    Dey, Sanchita; Mardinly, John; Wang, Yongqiang; ...

    2016-05-27

    Grain boundaries are effective sinks for radiation-induced defects, ultimately impacting the radiation tolerance of nanocrystalline materials (dense materials with nanosized grains) against net defect accumulation. However, irradiation-induced grain growth leads to grain boundary area decrease, shortening potential benefits of nanostructures. A possible approach to mitigate this is the introduction of dopants to target a decrease in grain boundary mobility or a reduction in grain boundary energy to eliminate driving forces for grain growth (using similar strategies as to control thermal growth). Here, in this study, we tested this concept in nanocrystalline zirconia doped with lanthanum. Although the dopant is observedmore » to segregate to the grain boundaries, causing grain boundary energy decrease and promoting dragging forces for thermally activated boundary movement, irradiation induced grain growth could not be avoided under heavy ion irradiation, suggesting a different growth mechanism as compared to thermal growth. Furthermore, it is apparent that reducing the grain boundary energy reduced the effectiveness of the grain boundary as sinks, and the number of defects in the doped material is higher than in undoped (La-free) YSZ.« less

  20. Irradiation-induced grain growth and defect evolution in nanocrystalline zirconia with doped grain boundaries

    SciTech Connect

    Dey, Sanchita; Mardinly, John; Wang, Yongqiang; Valdez, James Anthony; Holesinger, Terry George; Uberuaga, Blas P.; Ditto, Jeff J.; Drazin, John W.; Castro, Ricardo H. R.

    2016-05-27

    Grain boundaries are effective sinks for radiation-induced defects, ultimately impacting the radiation tolerance of nanocrystalline materials (dense materials with nanosized grains) against net defect accumulation. However, irradiation-induced grain growth leads to grain boundary area decrease, shortening potential benefits of nanostructures. A possible approach to mitigate this is the introduction of dopants to target a decrease in grain boundary mobility or a reduction in grain boundary energy to eliminate driving forces for grain growth (using similar strategies as to control thermal growth). Here, in this study, we tested this concept in nanocrystalline zirconia doped with lanthanum. Although the dopant is observed to segregate to the grain boundaries, causing grain boundary energy decrease and promoting dragging forces for thermally activated boundary movement, irradiation induced grain growth could not be avoided under heavy ion irradiation, suggesting a different growth mechanism as compared to thermal growth. Furthermore, it is apparent that reducing the grain boundary energy reduced the effectiveness of the grain boundary as sinks, and the number of defects in the doped material is higher than in undoped (La-free) YSZ.

  1. PEDF-induced alteration of metabolism leading to insulin resistance.

    PubMed

    Carnagarin, Revathy; Dharmarajan, Arunasalam M; Dass, Crispin R

    2015-02-05

    Pigment epithelium-derived factor (PEDF) is an anti-angiogenic, immunomodulatory, and neurotrophic serine protease inhibitor protein. PEDF is evolving as a novel metabolic regulatory protein that plays a causal role in insulin resistance. Insulin resistance is the central pathogenesis of metabolic disorders such as obesity, type 2 diabetes mellitus, polycystic ovarian disease, and metabolic syndrome, and PEDF is associated with them. The current evidence suggests that PEDF administration to animals induces insulin resistance, whereas neutralisation improves insulin sensitivity. Inflammation, lipolytic free fatty acid mobilisation, and mitochondrial dysfunction are the proposed mechanism of PEDF-mediated insulin resistance. This review summarises the probable mechanisms adopted by PEDF to induce insulin resistance, and identifies PEDF as a potential therapeutic target in ameliorating insulin resistance.

  2. Mechanically induced alterations in cultured skeletal muscle growth

    NASA Technical Reports Server (NTRS)

    Vandenburgh, H. H.; Hatfaludy, S.; Karlisch, P.; Shansky, J.

    1991-01-01

    Model systems are available for mechanically stimulating cultured skeletal muscle cells by passive tensile forces which simulate those found in vivo. When applied to embryonic muscle cells in vitro these forces induce tissue organogenesis, metabolic adaptations, and muscle cell growth. The mechanical stimulation of muscle cell growth correlates with stretch-induced increases in the efflux of prostaglandins PGE2 and PGF2(alpha) in a time and frequency dependent manner. These prostaglandins act as mechanical 'second messengers' regulating skeletal muscle protein turnover rates. Since they also effect bone remodelling in response to tissue loading and unloading, secreted prostaglandins may serve as paracrine growth factors, coordinating the growth rates of muscle and bone in response to external mechanical forces. Cell culture model systems will supplement other models in understanding mechanical transduction processes at the molecular level.

  3. Alteration of fibroblast phenotype by asbestos-induced autoantibodies.

    PubMed

    Pfau, Jean C; Li, Sheng'ai; Holland, Sara; Sentissi, Jami J

    2011-06-01

    Pulmonary fibrosis is a relentlessly progressive disease for which the etiology can be idiopathic or associated with environmental or occupational exposures. There is not a clear explanation for the chronic and progressive nature of the disease, leaving treatment and prevention options limited. However, there is increasing evidence of an autoimmune component, since fibrotic diseases are often accompanied by production of autoantibodies. Because exposure to silicates such as silica and asbestos can lead to both autoantibodies and pulmonary/pleural fibrosis, these exposures provide an excellent tool for examining the relationship between these outcomes. This study explored the possibility that autoantibodies induced by asbestos exposure in mice would affect fibroblast phenotype. L929 fibroblasts and primary lung fibroblasts were treated with serum IgG from asbestos- or saline-treated mice, and tested for binding using cell-based ELISA, and for phenotypic changes using immunofluorescence, laser scanning cytometry and Sirius Red collagen assay. Autoantibodies in the serum of C57Bl/6 mice exposed to asbestos (but not sera from untreated mice) bound to mouse fibroblasts. The autoantibodies induced differentiation to a myofibroblast phenotype, as demonstrated by increased expression of smooth muscle α-actin (SMA), which was lost when the serum was cleared of IgG. Cells treated with purified IgG of exposed mice produced excess collagen. Using ELISA, we tested serum antibody binding to DNA topoisomerase (Topo) I, vimentin, TGFβ-R, and PDGF-Rα. Antibodies to DNA Topo I and to PDGF-Rα were detected, both of which have been shown by others to be able to affect fibroblast phenotype. The anti-fibroblast antibodies (AFA) also induced STAT-1 activation, implicating the PDGF-R pathway as part of the response to AFA binding. These data support the hypothesis that asbestos induces AFA that modify fibroblast phenotype, and suggest a mechanism whereby autoantibodies may mediate

  4. Anoxia-conditioning hormesis alters the relationship between irradiation doses for survival and sterility in the cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most important components of a Sterile Insect Technique (SIT) program is appropriate irradiation dose. Knowing the organismal dose-response enables the selection of a dose that induces the highest level of sterility while preserving the sexual competitiveness and quality of the sterile in...

  5. Combined changes in Wnt signaling response and contact inhibition induce altered proliferation in radiation-treated intestinal crypts

    PubMed Central

    Dunn, S.-J.; Osborne, J. M.; Appleton, P. L.; Näthke, I.

    2016-01-01

    Curative intervention is possible if colorectal cancer is identified early, underscoring the need to detect the earliest stages of malignant transformation. A candidate biomarker is the expanded proliferative zone observed in crypts before adenoma formation, also found in irradiated crypts. However, the underlying driving mechanism for this is not known. Wnt signaling is a key regulator of proliferation, and elevated Wnt signaling is implicated in cancer. Nonetheless, how cells differentiate Wnt signals of varying strengths is not understood. We use computational modeling to compare alternative hypotheses about how Wnt signaling and contact inhibition affect proliferation. Direct comparison of simulations with published experimental data revealed that the model that best reproduces proliferation patterns in normal crypts stipulates that proliferative fate and cell cycle duration are set by the Wnt stimulus experienced at birth. The model also showed that the broadened proliferation zone induced by tumorigenic radiation can be attributed to cells responding to lower Wnt concentrations and dividing at smaller volumes. Application of the model to data from irradiated crypts after an extended recovery period permitted deductions about the extent of the initial insult. Application of computational modeling to experimental data revealed how mechanisms that control cell dynamics are altered at the earliest stages of carcinogenesis. PMID:27053661

  6. Targeting Pro-Apoptotic TRAIL Receptors Sensitizes HeLa Cervical Cancer Cells to Irradiation-Induced Apoptosis

    SciTech Connect

    Maduro, John H.; Vries, Elisabeth de; Meersma, Gert-Jan; Hougardy, Brigitte; Zee, Ate G.J. van der; Jong, Steven de

    2008-10-01

    Purpose: To investigate the potential of irradiation in combination with drugs targeting the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor (DR)4 and DR5 and their mechanism of action in a cervical cancer cell line. Methods and Materials: Recombinant human TRAIL (rhTRAIL) and the agonistic antibodies against DR4 and DR5 were added to irradiated HeLa cells. The effect was evaluated with apoptosis and cytotoxicity assays and at the protein level. Membrane receptor expression was measured with flow cytometry. Small-interfering RNA against p53, DR4, and DR5 was used to investigate their function on the combined effect. Results: rhTRAIL and the agonistic DR4 and DR5 antibodies strongly enhanced 10-Gy-induced apoptosis. This extra effect was 22%, 23%, and 29% for rhTRAIL, DR4, and DR5, respectively. Irradiation increased p53 expression and increased the membrane expression of DR5 and DR4. p53 suppression, as well as small-interfering RNA against DR5, resulted in a significant downregulation of DR5 membrane expression but did not affect apoptosis induced by irradiation and rhTRAIL. After small-interfering RNA against DR4, rhTRAIL-induced apoptosis and the additive effect of irradiation on rhTRAIL-induced apoptosis were abrogated, implicating an important role for DR4 in apoptosis induced through irradiation in combination with rhTRAIL. Conclusion: Irradiation-induced apoptosis is strongly enhanced by targeting the pro-apoptotic TRAIL receptors DR4 or DR5. Irradiation results in a p53-dependent increase in DR5 membrane expression. The sensitizing effect of rhTRAIL on irradiation in the HeLa cell line is, however especially mediated through the DR4 receptor.

  7. Alterations in locomotor activity induced by radioprotective doses of 16,16-dimethyl prostaglandin E2

    SciTech Connect

    Landauer, M.R.; Walden, T.L.; Davis, H.D.; Dominitz, J.A.

    1987-01-01

    16,16-Dimethyl prostaglandin E2 (DiPGE2) is an effective radioprotectant when administered before irradiation. A notable side effect of this compound is sedation. In separate experiments, the dose-response determinations of the time course of locomotor activity and 30-day survival after 10 Gy gamma irradiation (LD100) were made. Adult male CD2F1 mice were injected subcutaneously with vehicle or DiPGE2 in doses ranging from 0.01 to 40 micrograms per mouse. A dose of 0.01 micrograms did not result in alterations in locomotor behaviour or enhance survival. Doses greater than 1 microgram produced ataxia and enhanced radiation survival in a dose-dependent fashion. Full recovery of locomotor activity did not occur until 6 and 30 hr after injection for the 10 microgram and 40 microgram groups, respectively. Radioprotection was observed when DiPGE2 was administered preirradiation but not postirradiation. Doses of 1 and 10 micrograms were maximally effective as a radioprotectant if injected 5 min prior to irradiation (80%-90% survival). A dose of 40 micrograms resulted in 100% survival when injected 5-30 min before irradiation. Therefore, increasing doses of DiPGE2 resulted in an enhanced effectiveness as a radioprotectant. However, the doses that were the most radioprotective were also the most debilitating to the animal.

  8. Light-Induced Alterations in Striatal Neurochemical Profiles

    NASA Technical Reports Server (NTRS)

    Sroufe, Angela E.; Whittaker, J. A.; Patrickson, J. W.

    1997-01-01

    Much of our present knowledge regarding circadian rhythms and biological activity during space flight has been derived from those missions orbiting the Earth. During space missions, astronauts can become exposed to bright/dark cycles that vary considerably from those that entrain the mammalian biological timing system to the 24-hour cycle found on Earth. As a spacecraft orbits the Earth, the duration of the light/dark period experienced becomes a function of the time it takes to circumnavigate the planet which in turn depends upon the altitude of the craft. Orbiting the Earth at an altitude of 200-800 km provides a light/dark cycle lasting between 80 and 140 minutes, whereas a voyage to the moon or even another planet would provide a light condition of constant light. Currently, little is known regarding the effects of altered light/dark cycles on neurochemical levels within the central nervous system (CNS). Many biochemical, physiological and behavioral phenomena are under circadian control, governed primarily by the hypothalamic suprachiasmatic nucleus. As such, these phenomena are subject to influence by the environmental light/dark cycle. Circadian variations in locomotor and behavioral activities have been correlated to both the environmental light/dark cycle and to dopamine (DA) levels within the CNS. It has been postulated by Martin-Iverson et al. that DA's role in the control of motor activity is subject to modulation by circadian rhythms (CR), environmental lighting and excitatory amino acids (EAAs). In addition, DA and EAA receptor regulated pathways are involved in both the photic entrainment of CR and the control of motor activity. The cellular mechanisms by which DA and EAA-receptor ligands execute these functions, is still unclear. In order to help elucidate these mechanisms, we set out to determine the effects of altered environmental light/dark cycles on CNS neurotransmitter levels. In this study, we focused on the striatum, a region of the brain

  9. Shape- and size-controllable microstructure on glass surface induced by femtosecond laser irradiation.

    PubMed

    Teng, Yu; Zhou, Jiajia; Luo, Fangfang; Ma, Zhijun; Lin, Geng; Qiu, Jianrong

    2010-07-01

    Controllable microstructures are formed on a glass surface after irradiation of a focused 800 nm, 250 KHz femtosecond laser beam. Field-emission scanning electron microscope and 3D measuring laser microscope images reveal that the induced structures are circular and linear protuberances and can be controlled from 10 microm to hundreds of micrometers in width, and from 1 microm to tens of micrometers in height. The protuberance structure is proposed to be formed as a consequence of the laser-induced high temperature and pressure owing to linear and nonlinear absorption near the laser focal point, and low softening and melting temperature of the glass sample.

  10. Defect-induced magnetism in neutron irradiated 6H-SiC single crystals.

    PubMed

    Liu, Yu; Wang, Gang; Wang, Shunchong; Yang, Jianhui; Chen, Liang; Qin, Xiubo; Song, Bo; Wang, Baoyi; Chen, Xiaolong

    2011-02-25

    Defect-induced magnetism is firstly observed in neutron irradiated SiC single crystals. We demonstrated that the intentionally created defects dominated by divacancies (V(Si)V(C)) are responsible for the observed magnetism. First-principles calculations revealed that defect states favor the formation of local moments and the extended tails of defect wave functions make long-range spin couplings possible. Our results confirm the existence of defect-induced magnetism, implying the possibility of tuning the magnetism of wide band-gap semiconductors by defect engineering.

  11. Effects of a low-level semiconductor gallium arsenide laser on local pathological alterations induced by Bothrops moojeni snake venom.

    PubMed

    Aranha de Sousa, Elziliam; Bittencourt, José Adolfo Homobono Machado; Seabra de Oliveira, Nayana Keyla; Correia Henriques, Shayanne Vanessa; dos Santos Picanço, Leide Caroline; Lobato, Camila Pena; Ribeiro, José Renato; Pereira, Washington Luiz Assunção; Carvalho, José Carlos Tavares; da Silva, Jocivânia Oliveira

    2013-10-01

    Antivenom therapy has been ineffective in neutralizing the tissue damage caused by snakebites. Among therapeutic strategies to minimize effects after envenoming, it was hypothesized that a low level laser would reduce complications and reduce the severity of local snake venom effects. In the current study, the effect of a low-level semiconductor gallium arsenide (GaAs) laser on the local pathological alterations induced by B. moojeni snake venom was investigated. The experimental groups consisted of five male mice, each administered either B. moojeni venom (VB), B. moojeni venom + antivenom (VAV), B. moojeni venom + laser (VL), B. moojeni venom + antivenom + laser (VAVL), or sterile saline solution (SSS) alone. Paw oedema was induced by intradermal administration of 0.05 mg kg(-1) of B. moojeni venom and was expressed in mm of directly induced oedema. Mice received by subcutaneous route 0.20 mg kg(-1) of venom for evaluating nociceptive activity and the time (in seconds) spent in licking and biting the injected paw was taken as an indicator of pain response. Inflammatory infiltration was determined by counting the number of leukocytes present in the gastrocnemius muscle after venom injection (0.10 mg kg(-1)). For histological examination of myonecrosis, venom (0.10 mg kg(-1)) was administered intramuscularly. The site of venom injection was irradiated by the GaAs laser and some animals received antivenom intraperitoneally. The results indicated that GaAs laser irradiation can help in reducing some local effects produced by the B. moojeni venom in mice, stimulating phagocytosis, proliferation of myoblasts and the regeneration of muscle fibers.

  12. Alterations in glucose kinetics induced by pentobarbital anesthesia

    SciTech Connect

    Lang, C.H.; Bagby, G.J.; Hargrove, D.M.; Hyde, P.M.; Spitzer, J.J. )

    1987-12-01

    Because pentobarbital is often used in investigations related to carbohydrate metabolism, the in vivo effect of this drug on glucose homeostasis was studied. Glucose kinetics assessed by the constant intravenous infusion of (6-{sup 3}H)- and (U-{sup 14}C)glucose, were determined in three groups of catheterized fasted rats: conscious, anesthetized and body temperature maintained, and anesthetized but body temperature not maintained. After induction of anesthesia, marked hypothermia developed in rats not provided with external heat. Anesthetized rats that developed hypothermia showed a decrease in mean arterial blood pressure (25%) and heart rate (40%). Likewise, the plasma lactate concentration and the rates of glucose appearance, recycling, and metabolic clearance were reduced by 30-50% in the hypothermic anesthetized rats. Changes in whole-body carbohydrate metabolism were prevented when body temperature was maintained. Because plasma pentobarbital levels were similar between the euthermic and hypothermic rats during the first 2 h of the experiment, the rapid reduction in glucose metabolism in this latter group appears related to the decrease in body temperature. The continuous infusion of epinephrine produced alterations in glucose kinetics that were not different between conscious animals and anesthetized rats with body temperature maintained. Thus pentobarbital-anesthetized rats became hypothermic when kept at room temperature and exhibited marked decreases in glucose metabolism. Such changes were absent when body temperature was maintained during anesthesia.

  13. Inhibiting the repair of DNA damage induced by gamma irradiation in rat thymocytes

    SciTech Connect

    Smit, J.A.; Stark, J.H.

    1994-01-01

    This study assessed the ability of 11 established and potential radiosensitizing agents to retard the repair of radiation-induced DNA damage with a view to enhancing the immunosuppressive effects of in vivo lymphoid irradiation. The capability of irradiated rat thymocytes to repair DNA damage was assessed by an adaptation of the fluorimetric unwinding method. Three compounds, 3-aminobenzamide (3-AB), novobiocin and flavone-8-acetic acid (FAA), inhibited repair significantly. We also report the effect of low-dose irradiation combined with repair inhibitors on the relationship between DNA strand breaks, fragmentation, cell viability and use of nicotinamide adenine dinucleotide (NAD). DNA fragmentation was increased by 1 mM/l FAA, 1 mM/l novobiocin and 50 {mu}M/l RS-61443 within 3 h of incubation. The latter two compounds also proved cytotoxic. All three drugs augmented the effect of ionizing radiation on the use of NAD. Of the agents investigated, FAA showed the most promise for augmenting the immunosuppressive action of irradiation at nontoxic, pharmacokinetically achievable concentrations. 33 refs., 1 fig., 2 tabs.

  14. Spatially-Selective Membrane Permeabilization Induced by Cell-Solution Electrode Atmospheric Pressure Plasma Irradiation

    NASA Astrophysics Data System (ADS)

    Sasaki, Shota; Hokari, Yutaro; Kanzaki, Makoto; Kaneko, Toshiro

    2015-09-01

    Gene transfection, which is the process of deliberately introducing nucleic acids into cells, is expected to play an important role in medical treatment because the process is necessary for gene therapy and creation of induced pluripotent stem (iPS) cells. However, the conventional transfection methods have some problems, so we focus attention on promising transfection methods by atmospheric pressure plasma (APP). We have previously reported that the cell membrane permeability, which is closely related with gene transfection, is improved using a cell-solution electrode for generating He-APP. He-APP is irradiated to the solution containing the adherent cells and delivery materials such as fluorescent dyes (YOYO-1) and plasmid DNA (GFP). In case of YOYO-1 delivery, more than 80% of cells can be transferred only in the plasma-irradiated area and the spatially-selective membrane permeabilization is realized by the plasma irradiation. In addition, it is confirmed that plasmid DNA is transfected and the GFP genes are expressed using same APP irradiation system with no obvious cellular damage.

  15. The Role of DNA Methylation Changes in Radiation-Induced Bystander Effects in cranial irradiated Mice

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Sun, Yeqing; Xue, Bei; Wang, Xinwen; Wang, Jiawen

    2016-07-01

    Heavy-ion radiation could lead to bystander effect in neighboring non-hit cells by signals released from directly-irradiated cells. The exact mechanisms of radiation-induced bystander effect in distant organ remain obscure, yet accumulating evidence points to the role of DNA methylation changes in bystander effect. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male Balb/c and C57BL mice were cranial exposed to 40, 200, 2000mGy dose of carbon heavy-ion radiation, while the rest of the animal body was shielded. The γH2AX foci as the DNA damage biomarker in directly irradiation organ ear and the distant organ liver were detected on 0, 1, 2, 6, 12 and 24h after radiation, respectively. Methylation-sensitive amplifcation polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that cranial irradiated mice could induce the γH2AX foci and genomic DNA methylation changes significantly in both the directly irradiation organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate were highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation in ear. The global DNA methylation changes tended to occur in the CG sites. We also found that the numbers of γH2AX foci and the genomic methylation changes of heavy-ion radiation-induced bystander effect in liver could be obvious 1 h after radiation and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in both directly radiation organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo. Keywords: Heavy-ion radiation; Bystander effect; DNA methylation; γH2

  16. Particle irradiation induces FGF2 expression in normal human lens cells

    NASA Technical Reports Server (NTRS)

    Chang, P. Y.; Bjornstad K, A.; Chang, E.; McNamara, M.; Barcellos-Hoff, M. H.; Lin, S. P.; Aragon, G.; Polansky, J. R.; Lui, G. M.; Blakely, E. A.

    2000-01-01

    Particle Irradiation Induces FGF2 Expression in Normal Human Lens Cells. Particle radiations, including both proton and helium-ion beams, have been used to successfully treat choroidal melanoma, but with the complication of radiation-induced cataract. We have investigated a role for radiation-induced changes in the expression of basic fibroblast growth factor (FGF2) gene expression as part of the mechanism(s) underlying lens cell injury associated with cataract. Normal human lens epithelial (HLE) cells were cultured in vitro on extracellular matrix (ECM) originated from bovine corneal endothelial cells. This study reports evidence for rapid but transient induction of FGF2 transcripts, an increase of between 5- and 8-fold, within 0.5 h after exposure to particle radiation, followed by another wave of increased transcription at 2-3 h postirradiation. Immunofluorescence results confirm the enhanced levels of FGF2 protein rapidly after exposure to protons or helium ions, followed by another wave of increased activity unique to helium at 6 h postirradiation. This second wave of increased immunoreactivity was not observed in the proton-irradiated samples. Total FGF2 protein analysis after helium-ion exposures shows induced expression of three FGF2 isoforms, with an increase of up to 2-fold in the 18-kDa low-molecular-weight species. Studies of the effects of protons on individual FGF2 protein isoforms are in progress. Several mechanisms involving a role for FGF2 in radiation-induced cataract are discussed.

  17. Prevention of chemically induced two-stage skin carcinogenesis in mice by systemic effects of ultraviolet irradiation.

    PubMed

    Gensler, H L

    1988-05-01

    Systemic effects of UVB irradiation (280 to 320 nm) have been shown to enhance subsequent carcinogenesis induced by UV irradiation or by high doses of benzo[a]pyrene. In the present study, we asked whether the systemic effects of UVB irradiation would influence subsequent chemical tumorigenesis induced by the initiation-promotion protocol. A group of B6D2F1/J mice were irradiated dorsally with five 30-min treatments per week for 11.5 weeks. The irradiation source was a bank of six unfiltered Westinghouse FS40 sun lamps. One week later, irradiated and unirradiated mice were initiated ventrally with 100 micrograms of 7,12-dimethylbenz[a]anthracene. Four days later, ventral 12-O-tetradecanoylphorbol-13-acetate treatments were begun. After 20 weeks of promotion, there were 75% fewer tumors per mouse in the irradiated mice than in unirradiated mice. Thus, systemic effects of UVB irradiation resulted in inhibition of chemical carcinogenesis induced with an initiation-promotion protocol.

  18. Alterations in repair of alkylating agent-induced DNA damage in polyamine-depleted human cells.

    PubMed

    Snyder, R D; Bhatt, S

    1993-08-16

    Treatment of HeLa cells with the polyamine biosynthesis inhibitors difluoromethylornithine (DFMO) and/or methylglyoxal bis(guanylhydrazone) (MGBG) results in marked depression in levels of the cellular polyamines putrescine, spermidine and spermine. Cells in this polyamine-depleted state exhibited increased sensitivity to monofunctional alkylating agents, manifested as decreased cloning ability and retardation of the DNA excision repair process. DFMO treatment did not alter the initial level of interaction of radiolabeled alkylating agent with cellular DNA, but combined treatment with DFMO and MGBG reduced covalent binding, probably through effects on cell cycling. Polyamine supplementation had no effects on initial yield of DNA single-strand breaks in drug-treated cells. The repair defect appeared similar to that observed previously in polyamine-depleted cells following X-irradiation and UV irradiation, namely retarded sealing of DNA strand breaks. It was not possible to reverse the effects of these inhibitors by short periods of polyamine loading, despite the fact that all three polyamines could be restored to near-normal levels. These findings provide the first demonstration of altered response of polyamine-depleted cells to monofunctional alkylating agents and contribute to our understanding of altered responses of polyamine-depleted cancer cells to a variety of DNA-reactive chemotherapeutic drugs.

  19. Altered Acer Rubrum Fecundity Induced By Chemical Climate Change

    NASA Astrophysics Data System (ADS)

    Deforest, J. L.; Peters, A.

    2014-12-01

    Red maple (Acer rubrum L.) is becoming the most dominating tree in North American eastern deciduous forests. Concurrently, human activities have altered the chemical climate of terrestrial ecosystems via acidic deposition, which increases the available of nitrogen (N), while decreasing phosphorus (P) availability. Once a minor forest component prior to European settlement, the abundance of red maple may be a symptom of the modern age. The current paradigm explaining red maple's rise to prominence concerns fire suppression that excludes competitors. However, this still does not explain why red maple is unique compared to other functionally similar trees. The objective of this study was to investigate the interactive influence of acid rain mitigation on the fecundity of red maple. Objectives were achieved by measuring flowering, seed production, germination, and growth from red maple on plots that have been experimentally manipulated to increase soil pH, P, or both in three unglaciated eastern deciduous hardwood forests. At least 50% of the red maple population is seed bearing in our control soils, however the median percent of seed-bearing trees declined to zero when mitigating soils from acidic deposition. This can be explained by the curious fact that red maple is polygamodioecious, or has labile sex-expression, in which an individual tree can change its sex-expression in response to the environment. Furthermore, seed-bearing trees in the mitigated plots grew less, produced less seeds, and germinated at lower rates than their counterparts in control soils. Our results provide evidence that chemical climate change could be the primary contributing factor accelerating the dominance of red maple in eastern North American forests. Our observations can provide a boarder conceptual framework for understanding how nutrient limitations can be applied beyond plant productivity towards explaining distribution changes in vegetation.

  20. Dielectric-thickness dependence of damage induced by electron-beam irradiation of MNOS gate pattern

    NASA Astrophysics Data System (ADS)

    Matsui, Miyako; Mine, Toshiyuki; Hozawa, Kazuyuki; Watanabe, Kikuo; Inoue, Jiro; Nagaishi, Hiroshi

    2007-03-01

    We analyzed the electron-irradiation damage induced by electron-beam inspection of MNOS capacitors with various gate-dielectric thicknesses. Damage induced in a MNOS capacitor with SiON dielectric for high-performance CMOS devices was compared with that induced on a MOS capacitor with SiO II dielectric. We found that there is no remarkable difference between the damage to MOS capacitors and that to MNOS capacitors. The induced damage strongly depends on the thickness of the gate dielectric. Damages were induced when a higher-energy electron-beam, whose electron range was larger than the thickness of the gate electrode, was irradiated. When the electron beam was irradiated to a MOS capacitor with gate-dielectric thickness of 10.0 nm the flat-band-voltage shifted due to the created traps. When the electron beam was scanned to a MOS or MNOS capacitor with gate-dielectric thickness of 4.0 nm, Vfb shifted by less than 6 mV. However, the leakage-current density increased to 10 -7 A/cm2 at gate-electrode voltage of 3.0 V. On the other hand, when the electron beam was scanned on a MNOS capacitor with 2.5-nm-thick SiON dielectric, even the leakage current density was not increased. Accordingly, for damage-free inspection when gate-dielectric thickness is 4.0 nm or more, the electron-beam energy should be lower so that the electron range is smaller than the thickness of the gate electrode.

  1. Plasma-induced Escape and Alterations of Planetary Atmospheres

    NASA Astrophysics Data System (ADS)

    Johnson, R. E.; Tucker, O. J.; Ewrin, J.; Cassidy, T. A.; Leblanc, F.

    2009-12-01

    The atmospheres of planets and planetary satellites are typically imbedded in space plasmas. Depending on the interaction with the induced or intrinsic fields energetic ions can have access to the thermosphere and the corona affecting their composition and thermal structure and causing loss to space. These processes are often lumped together as ‘atmospheric sputtering’ (Johnson 1994). In this talk I will review the results of simulations of the plasma bombardment at a number of solar system bodies and use those data to describe the effect on the upper atmosphere and on escape. Of considerable recent interest is the modeling of escape from Titan. Prior to Cassini’s tour of the Saturnian system, plasma-induced escape was suggested to be the dominant loss process, but recent models of enhanced thermal escape, often referred to as ‘slow hydrodynamic’ escape, have been suggested to lead to much larger Titan atmospheric loss rates (Strobel 2008; Cui et al. 2008). Such a process has been suggested to be active at some point in time on a number of solar system bodies. I will present hybrid fluid/ kinetic models of the upper atmosphere of certain bodies in order to test both the plasma-induced and thermal escape processes. Preliminary results suggest that the loss rates estimated using the ‘slow hydrodynamic’ escape process can be orders of magnitude too large. The implications for Mars, Titan and Pluto will be discussed. Background for this talk is contained in the following papers (Johnson 2004; 2009; Chaufray et al. 2007; Johnson et al. 2008; 2009; Tucker and Johnson 2009). References: Chaufray, J.Y., R. Modolo, F. Leblanc, G. Chanteur, R.E. Johnson, and J.G. Luhmann, Mars Solar Wind interaction: formation of the Martian corona and atmosphric loss to space, JGR 112, E09009, doi:10.1029/2007JE002915 (2007) Cui, J., Yelle, R. V., Volk, K. Distribution and escape of molecular hydrogen in Titan's thermosphere and exosphere. J. Geophys. Res. 113, doi:10

  2. Light-Induced Alterations in Basil Ganglia Kynurenic Acid Levels

    NASA Technical Reports Server (NTRS)

    Sroufe, Angela E.; Whittaker, J. A.; Patrickson, J. W.; Orr, M. C.

    1997-01-01

    The metabolic synthesis, release and breakdown of several known CNS neurotransmitters have been shown to follow a circadian pattern entrained to the environmental light/dark cycle. The levels of excitatory amino acid (EAA) transmitters such as glutamate, have been shown to vary with environmental lighting conditions. Kynurenic Acid (KA), an endogenous tryptophan metabolite and glutamate receptor antagonist, has been reported to have neuroprotective effects against EAA-induced excitotoxic cell damage. Changes in KA's activity within the mammalian basal ganglia has been proposed as being contributory to neurotoxicity in Huntington's Disease. It is not known whether CNS KA levels follow a circadian pattern or exhibit light-induced fluctuations. However, because the symptoms of certain degenerative motor disorders seem to fluctuate with daily 24 hour rhythm, we initiated studies to determine if basal ganglia KA were influenced by the daily light/dark cycle and could influence motor function. Therefore in this study, HPLC-EC was utilized to determine if basal ganglia KA levels in tissue extracts from adult male Long-Evans rats (200-250g) entrained to 24 and 48 hours constant light and dark conditions, respectively. Samples were taken one hour before the onset of the subjective day and one hour prior to the onset of the subjective night in order to detect possible phase differences in KA levels and to allow for accumulation of factors expressed in association with the light or dark phase. Data analysis revealed that KA levels in the basal ganglia vary with environmental lighting conditions; being elevated generally during the dark. Circadian phase differences in KA levels were also evident during the subjective night and subjective day, respectively. Results from these studies are discussed with respect to potential cyclic changes in neuronal susceptibility to excitotoxic damage during the daily 24 hour cycle and its possible relevance to future therapeutic approaches in

  3. Swift heavy ion irradiation of ZnO nanoparticles embedded in silica: Radiation-induced deoxidation and shape elongation

    SciTech Connect

    Amekura, H.; Tsuya, D.; Mitsuishi, K.; Nakayama, Y.; Okubo, N.; Ishikawa, N.; Singh, U. B.; Khan, S. A.; Avasthi, D. K.; Mohapatra, S.

    2013-11-11

    ZnO nanoparticles (NPs) embedded in amorphous SiO{sub 2} were irradiated with 200 MeV Xe{sup 14+} swift heavy ions (SHIs) to a fluence of 5.0 × 10{sup 13} ions/cm{sup 2}. Optical linear dichroism was induced in the samples by the irradiation, indicating shape transformation of the NPs from spheres to anisotropic ones. Transmission electron microscopy observations revealed that some NPs were elongated to prolate shapes; the elongated NPs consisted not of ZnO but of Zn metal. The SHI irradiation induced deoxidation of small ZnO NPs and successive shape elongation of the deoxidized metal NPs.

  4. Post-irradiation dietary vitamin E does not affect the development of radiation-induced lung damage in rats.

    PubMed

    Wiegman, Erwin M; van Gameren, Mieke M; Kampinga, Harm H; Szabó, Ben G; Coppes, Rob P

    2004-07-01

    The purpose of this study was to investigate whether application of post-irradiation vitamin E, an anti-oxidant, could prevent the development of radiation induced lung damage. Wistar rats were given vitamin E enriched or vitamin E deprived food starting from 4 weeks after 18Gy single dose irradiation of the right thorax. Neither breathing frequencies nor CT density measurements revealed differences between the groups. It is concluded that post-irradiation vitamin E does not influence radiation-induced fibrosis to the lung.

  5. Radiation-induced functional connectivity alterations in nasopharyngeal carcinoma patients with radiotherapy

    PubMed Central

    Ma, Qiongmin; Wu, Donglin; Zeng, Ling-Li; Shen, Hui; Hu, Dewen; Qiu, Shijun

    2016-01-01

    Abstract The study aims to investigate the radiation-induced brain functional alterations in nasopharyngeal carcinoma (NPC) patients who received radiotherapy (RT) using functional magnetic resonance imaging (fMRI) and statistic scale. The fMRI data of 35 NPC patients with RT and 24 demographically matched untreated NPC patients were acquired. Montreal Cognitive Assessment (MoCA) was also measured to evaluate their global cognition performance. Multivariate pattern analysis was performed to find the significantly altered functional connections between these 2 groups, while the linear correlation level was detected between the altered functional connections and the MoCA scores. Forty-five notably altered functional connections were found, which were mainly located between 3 brain networks, the cerebellum, sensorimotor, and cingulo-opercular. With strictly false discovery rate correction, 5 altered functional connections were shown to have significant linear correlations with the MoCA scores, that is, the connections between the vermis and hippocampus, cerebellum lobule VI and dorsolateral prefrontal cortex, precuneus and dorsal frontal cortex, cuneus and middle occipital lobe, and insula and cuneus. Besides, the connectivity between the vermis and hippocampus was also significantly correlated with the attention score, 1 of the 7 subscores of the MoCA. The present study provides new insights into the radiation-induced functional connectivity impairments in NPC patients. The results showed that the RT may induce the cognitive impairments, especially the attention alterations. The 45 altered functional connections, especially the 5 altered functional connections that were significantly correlated to the MoCA scores, may serve as the potential biomarkers of the RT-induced brain functional impairments and provide valuable targets for further functional recovery treatment. PMID:27442663

  6. Radiation-induced functional connectivity alterations in nasopharyngeal carcinoma patients with radiotherapy.

    PubMed

    Ma, Qiongmin; Wu, Donglin; Zeng, Ling-Li; Shen, Hui; Hu, Dewen; Qiu, Shijun

    2016-07-01

    The study aims to investigate the radiation-induced brain functional alterations in nasopharyngeal carcinoma (NPC) patients who received radiotherapy (RT) using functional magnetic resonance imaging (fMRI) and statistic scale.The fMRI data of 35 NPC patients with RT and 24 demographically matched untreated NPC patients were acquired. Montreal Cognitive Assessment (MoCA) was also measured to evaluate their global cognition performance. Multivariate pattern analysis was performed to find the significantly altered functional connections between these 2 groups, while the linear correlation level was detected between the altered functional connections and the MoCA scores.Forty-five notably altered functional connections were found, which were mainly located between 3 brain networks, the cerebellum, sensorimotor, and cingulo-opercular. With strictly false discovery rate correction, 5 altered functional connections were shown to have significant linear correlations with the MoCA scores, that is, the connections between the vermis and hippocampus, cerebellum lobule VI and dorsolateral prefrontal cortex, precuneus and dorsal frontal cortex, cuneus and middle occipital lobe, and insula and cuneus. Besides, the connectivity between the vermis and hippocampus was also significantly correlated with the attention score, 1 of the 7 subscores of the MoCA.The present study provides new insights into the radiation-induced functional connectivity impairments in NPC patients. The results showed that the RT may induce the cognitive impairments, especially the attention alterations. The 45 altered functional connections, especially the 5 altered functional connections that were significantly correlated to the MoCA scores, may serve as the potential biomarkers of the RT-induced brain functional impairments and provide valuable targets for further functional recovery treatment.

  7. Cyclooxygenase inhibition does not alter methacholine-induced sweating.

    PubMed

    Fujii, Naoto; McGinn, Ryan; Paull, Gabrielle; Stapleton, Jill M; Meade, Robert D; Kenny, Glen P

    2014-11-01

    Cholinergic agents (e.g., methacholine) induce cutaneous vasodilation and sweating. Reports indicate that either nitric oxide (NO), cyclooxygenase (COX), or both can contribute to cholinergic cutaneous vasodilation. Also, NO is reportedly involved in cholinergic sweating; however, whether COX contributes to cholinergic sweating is unclear. Forearm sweat rate (ventilated capsule) and cutaneous vascular conductance (CVC, laser-Doppler perfusion units/mean arterial pressure) were evaluated in 10 healthy young (24 ± 4 yr) adults (7 men, 3 women) at four skin sites that were continuously perfused via intradermal microdialysis with 1) lactated Ringer (control), 2) 10 mM ketorolac (a nonselective COX inhibitor), 3) 10 mM N(G)-nitro-l-arginine methyl ester (l-NAME, a nonselective NO synthase inhibitor), or 4) a combination of 10 mM ketorolac + 10 mM l-NAME. At the four skin sites, methacholine was simultaneously infused in a dose-dependent manner (1, 10, 100, 1,000, 2,000 mM). Relative to the control site, forearm CVC was not influenced by ketorolac throughout the protocol (all P > 0.05), whereas l-NAME and ketorolac + l-NAME reduced forearm CVC at and above 10 mM methacholine (all P < 0.05). Conversely, there was no main effect of treatment site (P = 0.488) and no interaction of methacholine dose and treatment site (P = 0.711) on forearm sweating. Thus forearm sweating (in mg·min(-1)·cm(-2)) from baseline up to the maximal dose of methacholine was not different between the four sites (at 2,000 mM, control 0.50 ± 0.23, ketorolac 0.44 ± 0.23, l-NAME 0.51 ± 0.22, and ketorolac + l-NAME 0.51 ± 0.23). We show that both NO synthase and COX inhibition do not influence cholinergic sweating induced by 1-2,000 mM methacholine.

  8. Irradiation induced structural change in Mo2Zr intermetallic phase

    SciTech Connect

    Gan, J.; Keiser, Jr., D. D.; Miller, B. D.; Eriksson, N.; Sohn, Y. H.; Kirk, M.

    2016-05-14

    The Mo2Zr phase has been identified as a major interaction product at the interface of U-10Mo and Zr. Transmission electron microscopy in-situ irradiation with Kr ions at 200 °C with doses up to 2.0E+16 ions/cm2 was carried out to investigate the radiation stability of the Mo2Zr. The Mo2Zr undergoes a radiation-induced structural change, from a large cubic (cF24) to a small cubic (cI2), along with an estimated 11.2% volume contraction without changing its composition. The structural change begins at irradiation dose below 1.0E+14 ions/cm2. Furthermore, the transformed Mo2Zr phase demonstrates exceptional radiation tolerance with the development of dislocations without bubble formation.

  9. The effect of electronic energy loss on irradiation-induced grain growth in nanocrystalline oxides.

    PubMed

    Zhang, Yanwen; Aidhy, Dilpuneet S; Varga, Tamas; Moll, Sandra; Edmondson, Philip D; Namavar, Fereydoon; Jin, Ke; Ostrouchov, Christopher N; Weber, William J

    2014-05-07

    Grain growth of nanocrystalline materials is generally thermally activated, but can also be driven by irradiation at much lower temperature. In nanocrystalline ceria and zirconia, energetic ions deposit their energy to both atomic nuclei and electrons. Our experimental results have shown that irradiation-induced grain growth is dependent on the total energy deposited, where electronic energy loss and elastic collisions between atomic nuclei both contribute to the production of disorder and grain growth. Our atomistic simulations reveal that a high density of disorder near grain boundaries leads to locally rapid grain movement. The additive effect from both electronic excitation and atomic collision cascades on grain growth demonstrated in this work opens up new possibilities for controlling grain sizes to improve functionality of nanocrystalline materials.

  10. Increased P16 DNA Methylation in Mouse Thymic Lymphoma Induced by Irradiation

    PubMed Central

    Song, Wengang; Liu, Yongzhe; Liu, Ying; Zhang, Cong; Yuan, Bao; Zhang, Lianbo; Sun, Shilong

    2014-01-01

    DNA methylation is an important part of epigenetics. In this study, we examined the methylation state of two CpG islands in the promoter of the p16 gene in radiation-induced thymic lymphoma samples. The mRNA and protein levels of P16 were significantly reduced in radiation-induced thymic lymphoma tissue samples. Twenty-three CpG sites of the CpG islands in the p16 promoter region were detected, and the methylation percentages of −71, −63, −239, −29, −38, −40, −23, 46 CpG sites were significantly higher in radiation-induced thymic lymphoma tissue samples than those in matched non-irradiated thymus tissue samples. This study provides new evidence for the methylation state of p16 in the radiation-induced thymic lymphoma samples, which suggests that the methylation of these CpG sites in the p16 promoter may reduce its expression in the thymic lymphoma after irradiation. PMID:24747802

  11. Suppressor lymphocytes induced by epicutaneous sensitization of UV-irradiated mice control multiple immunological pathways.

    PubMed Central

    Ullrich, S E; Yee, G K; Kripke, M L

    1986-01-01

    The purpose of this study was to determine whether the formation of hapten-specific suppressor T lymphocytes induced by the epicutaneous sensitization of UV-irradiated mice could suppress other hapten-specific immune responses in addition to contact hypersensitivity (CHS). Suppressor cells were induced by applying trinitrochlorobenzene (TNCB) to the unexposed skin of mice irradiated several days earlier with 40 kJ/m2 UVB (280-320 nm) radiation. Previous work demonstrated that the spleens of such animals contain Lyt-1+, 2-T lymphocytes which prevent the induction of CHS to TNCB when transferred to normal mice, and inhibit proliferation of normal lymphocytes in vitro to TNP-modified syngeneic cells. These studies show that addition of T lymphocytes from UV-irradiated, TNCB-sensitized mice to cultures of normal lymphocytes and TNP-modified syngeneic cells inhibited the generation of TNP-specific cytotoxic T lymphocytes (CTL). The inhibition was dose-dependent and occurred only when the suppressor cells were present during the first 24 hr of culture. The suppressor cells had no effect on the activity of preformed CTL. In addition, injection of the suppressor lymphocytes into mice at the time of i.v. injection of TNP-modified sheep red blood cells (TNP-SRBC) reduced the number of direct plaque-forming cells against TNP, but had no effect on the production of antibody against SRBC. Cells that inhibited anti-TNP antibody formation were Thy-1+, Lyt-1+, 2-. These results indicate that hapten-specific suppressor cells from UV-irradiated mice prevent the activation of several different hapten-specific immunological pathways. PMID:2940172

  12. Irradiation With Carbon Ion Beams Induces Apoptosis, Autophagy, and Cellular Senescence in a Human Glioma-Derived Cell Line

    SciTech Connect

    Jinno-Oue, Atsushi; Shimizu, Nobuaki; Hamada, Nobuyuki; Wada, Seiichi; Tanaka, Atsushi; Shinagawa, Masahiko; Ohtsuki, Takahiro; Mori, Takahisa; Saha, Manujendra N.; Hoque, Ariful S.; Islam, Salequl; Kogure, Kimitaka; Funayama, Tomoo; Kobayashi, Yasuhiko

    2010-01-15

    Purpose: We examined biological responses of human glioma cells to irradiation with carbon ion beams (C-ions). Methods and Materials: A human glioma-derived cell line, NP-2, was irradiated with C-ions. Apoptotic cell nuclei were stained with Hoechst 33342. Induction of autophagy was examined either by staining cells with monodansylcadaverine (MDC) or by Western blotting to detect conversion of microtuble-associated protein light chain 3 (MAP-LC3) (LC3-I) to the membrane-bound form (LC3-II). Cellular senescence markers including induction of senescence-associated beta-galactosidase (SA-beta-gal) were examined. The mean telomere length of irradiated cells was determined by Southern blot hybridization. Expression of tumor suppressor p53 and cyclin/cyclin-dependent kinase inhibitor p21{sup WAF1/CIP1} in the irradiated cells was analyzed by Western blotting. Results: When NP-2 cells were irradiated with C-ions at 6 Gy, the major population of the cells died of apoptosis and autophagy. The residual fraction of attached cells (<1% of initially irradiated cells) could not form a colony: however, they showed a morphological phenotype consistent with cellular senescence, that is, enlarged and flattened appearance. The senescent nature of these attached cells was further indicated by staining for SA-beta-gal. The mean telomere length was not changed after irradiation with C-ions. Phosphorylation of p53 at serine 15 as well as the expression of p21{sup WAF1/CIP1} was induced in NP-2 cells after irradiation. Furthermore, we found that irradiation with C-ions induced cellular senescence in a human glioma cell line lacking functional p53. Conclusions: Irradiation with C-ions induced apoptosis, autophagy, and cellular senescence in human glioma cells.

  13. Irradiation creep in austenitic and ferritic steels irradiated in a tailored neutron spectrum to induce fusion reactor levels of helium

    SciTech Connect

    Grossbeck, M.L.; Gibson, L.T.; Jitsukawa, S.

    1996-04-01

    Six austenitic stainless steels and two ferritic alloys were irradiated sequentially in two research reactors where the neutron spectrum was tailored to produce a He production rate typical of a fusion device. Irradiation began in the Oak Ridge Research Reactor where an atomic displacement level of 7.4 dpa was achieved and was then transferred to the High Flux Isotope Reactor for the remainder of the irradiation to a total displacement level of 19 dpa. Temperatures of 60 and 330{degree}C are reported on. At 330{degree}C irradiation creep was found to be linear in stress and fluence with rates in the range of 1.7 - 5.5 x 10{sup -4}% MPa{sup -1} dpa{sup -1}. Annealed and cold-worked materials exhibited similar creep rates. There is some indication that austenitic alloys with TiC or TiO precipitates had a slightly higher irradiation creep rate than those without. The ferritic alloys HT-9 and Fe-16Cr had irradiatoin creep rates about 0.5 x 10{sup -4}% MPa{sup -1} dpa{sup -1}. No meaningful data could be obtained from the tubes irradiated at 60{degree}C because of damage to the tubes.

  14. Induced defences alter the strength and direction of natural selection on reproductive traits in common milkweed.

    PubMed

    Thompson, K A; Cory, K A; Johnson, M T J

    2017-01-30

    Evolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. Recent evidence indicates that constitutive antiherbivore defences can alter natural selection on reproductive traits, but it is unclear whether induced defences will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. In a factorial field experiment using common milkweed, Asclepias syriaca L., we induced plant defences using jasmonic acid (JA) and imposed foliar damage using scissors. We found that JA-induced plants experienced selection for more inflorescences that were smaller in size (fewer flowers), whereas control plants only experienced a trend towards selection for larger inflorescences (more flowers); all effects were independent of foliar damage. Our results demonstrate that induced defences can alter both the strength and direction of selection on reproductive traits, and suggest that antiherbivore defences may promote the evolution of plant reproductive diversity.

  15. Local and systemic biochemical alterations induced by Bothrops atrox snake venom in mice

    PubMed Central

    de Souza, Carlos AT; Kayano, Anderson M; Setúbal, Sulamita S; Pontes, Adriana S; Furtado, Juliana L; Kwasniewski, Fábio H; Zaqueo, Kayena D; Soares, Andreimar M; Stábeli, Rodrigo G; Zuliani, Juliana P

    2012-01-01

    The local and systemic alterations induced by Bothrops atrox snake venom (BaV) injection in mice were studied. BaV induced superoxide production by migrated neutrophils, mast cell degranulation and phagocytosis by macrophages. Moreover, BaV caused hemorrhage in dorsum of mice after 2hr post- injection. Three hours post-injection in gastrocnemius muscle, we also observed myonecrosis, which was assessed by the determination of serum and tissue CK besides the release of urea, but not creatinine and uric acid, indicating kidney alterations. BaV also induced the release of LDH and transaminases (ALT and AST) indicating tissue and liver abnormalities. In conclusion, the data indicate that BaV induces events of local and systemic importance. PMID:23487552

  16. Enhanced lithium-induced brain recovery following cranial irradiation is not impeded by inflammation.

    PubMed

    Malaterre, Jordane; McPherson, Cameron S; Denoyer, Delphine; Lai, Emily; Hagekyriakou, Jim; Lightowler, Sally; Shudo, Koishi; Ernst, Matthias; Ashley, David M; Short, Jennifer L; Wheeler, Greg; Ramsay, Robert G

    2012-06-01

    Radiation-induced brain injury occurs in many patients receiving cranial radiation therapy, and these deleterious effects are most profound in younger patients. Impaired neurocognitive functions in both humans and rodents are associated with inflammation, demyelination, and neural stem cell dysfunction. Here we evaluated the utility of lithium and a synthetic retinoid receptor agonist in reducing damage in a model of brain-focused irradiation in juvenile mice. We found that lithium stimulated brain progenitor cell proliferation and differentiation following cranial irradiation while also preventing oligodendrocyte loss in the dentate gyrus of juvenile mice. In response to inflammation induced by radiation, which may have encumbered the optimal reparative action of lithium, we used the anti-inflammatory synthetic retinoid Am80 that is in clinical use in the treatment of acute promyelocytic leukemia. Although Am80 reduced the number of cyclooxygenase-2-positive microglial cells following radiation treatment, it did not enhance lithium-induced neurogenesis recovery, and this alone was not significantly different from the effect of lithium on this proinflammatory response. Similarly, lithium was superior to Am80 in supporting the restoration of new doublecortin-positive neurons following irradiation. These data suggest that lithium is superior in its restorative effects to blocking inflammation alone, at least in the case of Am80. Because lithium has been in routine clinical practice for 60 years, these preclinical studies indicate that this drug might be beneficial in reducing post-therapy late effects in patients receiving cranial radiotherapy and that blocking inflammation in this context may not be as advantageous as previously suggested.

  17. Characteristics and mechanism of cell apoptosis induced by high fluence low-power laser irradiation

    NASA Astrophysics Data System (ADS)

    Wu, Shengnan; Xing, Da

    2008-02-01

    High fluence low-power laser irradiation (LPLI) can induce cell apoptosis which is mediated by a high level of mitochondrial reactive oxygen species (ROS) production; however the mechanism is still unclear. Here, we further studied the mitochondrial signaling pathways involved in the apoptotic process. Activation of caspase-9 indicated an apoptotic process occurred under the high fluence LPLI treatment. Increasing of dichlorodihydrofluorescein diacetate (H IIDCFDA) fluorescence products showed a high level of mitochondrial ROS generation after irradiation. Cyclosporine A (CsA) has been reported to inhibit some kinds of apoptosis, which are especially mediated by ROS. The question is whether CsA has some effect on high fluence LPLI induced apoptosis. Results showed that CsA significantly delayed mitochondria depolarization, observably delayed cell death in response to high fluence LPLI treatment demonstrating a significant protective role of CsA on the apoptotic process. These results suggest that high fluence LPLI induced cell apoptosis via some CsA-sensitive mitochondrial signal pathways.

  18. Topical Administration of Manuka Oil Prevents UV-B Irradiation-Induced Cutaneous Photoaging in Mice

    PubMed Central

    Kwon, Oh Sook; Yang, Beom Seok

    2013-01-01

    Manuka tree is indigenous to New Zealand, and its essential oil has been used as a traditional medicine to treat wounds, fever, and pain. Although there is a growing interest in the use of manuka oil for antiaging skin care products, little is known about its bioactivity. Solar ultraviolet (UV) radiation is the primary environmental factor causing skin damage and consequently premature aging. Therefore, we evaluated manuka oil for its effects against photoaging in UV-B-irradiated hairless mice. Topical application of manuka oil suppressed the UV-B-induced increase in skin thickness and wrinkle grading in a dose-dependent manner. Application of 10% manuka oil reduced the average length, depth, and % area of wrinkles significantly, and this was correlated with inhibition of loss of collagen fiber content and epidermal hyperplasia. Furthermore, we observed that manuka oil could suppress UV-B-induced skin inflammation by inhibiting the production of inflammatory cytokines. Taken together, this study provides evidence that manuka oil indeed possesses antiphotoaging activity, and this is associated with its inhibitory activity against skin inflammation induced by UV irradiation. PMID:23762170

  19. Irradiation exposure modulates central opioid functions

    SciTech Connect

    Dougherty, P.M.; Dafny, N.

    1987-11-01

    Exposure to low doses of gamma irradiation results in the modification of both the antinociceptive properties of morphine and the severity of naloxone-precipitated withdrawal in morphine-dependent rats. To better define the interactions between gamma irradiation and these opiate-mediated phenomena, dose-response studies were undertaken of the effect of irradiation on morphine-induced antinociception, and on the naloxone-precipitated withdrawal syndrome of morphine-dependent rats. In addition, electrophysiologic studies were conducted in rats after irradiation exposure and morphine treatment correlating with the behavioral studies. The observations obtained demonstrated that the antinociceptive effects of morphine as well as naloxone-precipitated withdrawal were modified in a dose-dependent manner by irradiation exposure. In addition, irradiation-induced changes in the evoked responses obtained from four different brain regions demonstrated transient alterations in both baseline and morphine-treated responses that may reflect the alterations observed in the behavioral paradigms. These results suggest that the effects of irradiation on opiate activities resulted from physiologic alterations of central endogenous opioid systems due to alterations manifested within peripheral targets.

  20. Diallyl disulfide attenuated carbon ion irradiation-induced apoptosis in mouse testis through changing the ratio of Tap73/ΔNp73 via mitochondrial pathway.

    PubMed

    Di, Cui-xia; Han, Lu; Zhang, Hong; Xu, Shuai; Mao, Ai-hong; Sun, Chao; Liu, Yang; Si, Jing; Li, Hong-yan; Zhou, Xin; Liu, Bing; Miao, Guo-ying

    2015-11-03

    Diallyl disulfide (DADS), a major organosulfur compound derived from garlic, has various biological properties, including anti-cancer effects. However, the protective mechanism of DADS against radiation-induced mouse testis cell apoptosis has not been elucidated. In this study, the magnitude of radiation effects evoked by carbon ion irradiation was marked by morphology changes, significant rise in apoptotic cells, activation expression of p53, up regulation the ratio of pro-apoptotic Tap73/anti-apoptotic ΔNp73, as well as alterations of crucial mediator of the mitochondrial pathway. Interestingly, pretreatment with DADS attenuated carbon ion irradiation-induced morphology damages and apoptotic cells. Additionally, DADS elevated radiation-induced p53 and p21 expression, suggesting that p53 might be involved in the inhibition of cell cycle progression through up regulation of p21. Furthermore, administration with DADS prevented radiation-induced Tap73/ΔNp73 expression and consequently down regulated Bax/Bcl-2 ratio, cytochrome c release and caspase-3 expression, indicating that the balance between Tap73 and ΔNp73 had potential to activate p53 responsive genes. Thus, our results showed that radio protection effect of DADS on mouse testis is mediated by blocking apoptosis through changing the ratio of Tap73/ΔNp73 via mitochondrial pathway, suggesting that DADS could be used as a potential radio protection agent for the testis against heavy-ion radiation.

  1. Diallyl disulfide attenuated carbon ion irradiation-induced apoptosis in mouse testis through changing the ratio of Tap73/ΔNp73 via mitochondrial pathway

    PubMed Central

    Di, Cui-xia; Han, Lu; Zhang, Hong; Xu, Shuai; Mao, Ai-hong; Sun, Chao; Liu, Yang; Si, Jing; Li, Hong-yan; Zhou, Xin; Liu, Bing; Miao, Guo-ying

    2015-01-01

    Diallyl disulfide (DADS), a major organosulfur compound derived from garlic, has various biological properties, including anti-cancer effects. However, the protective mechanism of DADS against radiation-induced mouse testis cell apoptosis has not been elucidated. In this study, the magnitude of radiation effects evoked by carbon ion irradiation was marked by morphology changes, significant rise in apoptotic cells, activation expression of p53, up regulation the ratio of pro-apoptotic Tap73/anti-apoptotic ΔNp73, as well as alterations of crucial mediator of the mitochondrial pathway. Interestingly, pretreatment with DADS attenuated carbon ion irradiation-induced morphology damages and apoptotic cells. Additionally, DADS elevated radiation-induced p53 and p21 expression, suggesting that p53 might be involved in the inhibition of cell cycle progression through up regulation of p21. Furthermore, administration with DADS prevented radiation-induced Tap73/ΔNp73 expression and consequently down regulated Bax/Bcl-2 ratio, cytochrome c release and caspase-3 expression, indicating that the balance between Tap73 and ΔNp73 had potential to activate p53 responsive genes. Thus, our results showed that radio protection effect of DADS on mouse testis is mediated by blocking apoptosis through changing the ratio of Tap73/ΔNp73 via mitochondrial pathway, suggesting that DADS could be used as a potential radio protection agent for the testis against heavy-ion radiation. PMID:26526304

  2. RelA-Mediated BECN1 Expression Is Required for Reactive Oxygen Species-Induced Autophagy in Oral Cancer Cells Exposed to Low-Power Laser Irradiation

    PubMed Central

    Wu, Chieh-Shan; Chen, Chien-Hsun; Wu, Sam; Chang, Hsueh-Wei; Kuo, Soong-Yu; Fu, Earl; Liu, Pei-Feng; Hsieh, Yao-Dung

    2016-01-01

    Low-power laser irradiation (LPLI) is a non-invasive and safe method for cancer treatment that alters a variety of physiological processes in the cells. Autophagy can play either a cytoprotective role or a detrimental role in cancer cells exposed to stress. The detailed mechanisms of autophagy and its role on cytotoxicity in oral cancer cells exposed to LPLI remain unclear. In this study, we showed that LPLI at 810 nm with energy density 60 J/cm2 increased the number of microtubule associated protein 1 light chain 3 (MAP1LC3) puncta and increased autophagic flux in oral cancer cells. Moreover, reactive oxygen species (ROS) production was induced, which increased RelA transcriptional activity and beclin 1 (BECN1) expression in oral cancer cells irradiated with LPLI. Furthermore, ROS scavenger or knockdown of RelA diminished LPLI-induced BECN1 expression and MAP1LC3-II conversion. In addition, pharmacological and genetic ablation of autophagy significantly enhanced the effects of LPLI-induced apoptosis in oral cancer cells. These results suggest that autophagy may be a resistant mechanism for LPLI-induced apoptosis in oral cancer cells. PMID:27632526

  3. RelA-Mediated BECN1 Expression Is Required for Reactive Oxygen Species-Induced Autophagy in Oral Cancer Cells Exposed to Low-Power Laser Irradiation.

    PubMed

    Shu, Chih-Wen; Chang, Hong-Tai; Wu, Chieh-Shan; Chen, Chien-Hsun; Wu, Sam; Chang, Hsueh-Wei; Kuo, Soong-Yu; Fu, Earl; Liu, Pei-Feng; Hsieh, Yao-Dung

    2016-01-01

    Low-power laser irradiation (LPLI) is a non-invasive and safe method for cancer treatment that alters a variety of physiological processes in the cells. Autophagy can play either a cytoprotective role or a detrimental role in cancer cells exposed to stress. The detailed mechanisms of autophagy and its role on cytotoxicity in oral cancer cells exposed to LPLI remain unclear. In this study, we showed that LPLI at 810 nm with energy density 60 J/cm2 increased the number of microtubule associated protein 1 light chain 3 (MAP1LC3) puncta and increased autophagic flux in oral cancer cells. Moreover, reactive oxygen species (ROS) production was induced, which increased RelA transcriptional activity and beclin 1 (BECN1) expression in oral cancer cells irradiated with LPLI. Furthermore, ROS scavenger or knockdown of RelA diminished LPLI-induced BECN1 expression and MAP1LC3-II conversion. In addition, pharmacological and genetic ablation of autophagy significantly enhanced the effects of LPLI-induced apoptosis in oral cancer cells. These results suggest that autophagy may be a resistant mechanism for LPLI-induced apoptosis in oral cancer cells.

  4. Analysis of expression pathways alterations of Arabidopsis thaliana induced by a Necrosis- and Ethylene-inducing protein

    NASA Astrophysics Data System (ADS)

    Sinigaglia, Marialva; Castro, Mauro A. A.; Echeverrigaray, Sérgio; Pereira, Gonçalo A. G.; Mombach, José C. M.

    2009-10-01

    A major goal in post-genomic biology is the description of physiological functions in terms of gene pathway behavior. In this work, we present the first investigation of expression alterations in ninety-three pathways representing physiological functions of the plant A. thaliana induced by a P. parasitica elicitor (NLPpp) using microarray data publicly available at the AtGenExpress database. Using a novel statistical analysis developed to detect pathway alterations, we identified the gene pathways, hereby called groups of functionally associated genes (defined according to the TAIR/Gene Ontology and other databases), that are significantly altered in response to the elicitor. Instead of looking at individual gene responses, our analysis allowed a detailed characterization of the time ordering of pathways alterations in response to the NLPpp, their physiological implications and specificity. We also observed the activation of genes associated with vesicle trafficking and ROS production implying the initiation of the senescence of the wounded plant tissue.

  5. Vulnerability of conditional NCAM-deficient mice to develop stress-induced behavioral alterations.

    PubMed

    Bisaz, Reto; Sandi, Carmen

    2012-03-01

    Previous studies in rodents showed that chronic stress induces structural and functional alterations in several brain regions, including shrinkage of the hippocampus and the prefrontal cortex, which are accompanied by cognitive and emotional disturbances. Reduced expression of the neural cell adhesion molecule (NCAM) following chronic stress has been proposed to be crucially involved in neuronal retraction and behavioral alterations. Since NCAM gene polymorphisms and altered expression of alternatively spliced NCAM isoforms have been associated with bipolar depression and schizophrenia in humans, we hypothesized that reduced expression of NCAM renders individuals more vulnerable to the deleterious effects of stress on behavior. Here, we specifically questioned whether mice in which the NCAM gene is inactivated in the forebrain by cre-recombinase under the control of the calcium-calmodulin-dependent kinase II promoter (conditional NCAM-deficient mice), display increased vulnerability to stress. We assessed the evolving of depressive-like behaviors and spatial learning and memory impairments following a subchronic stress protocol (2 weeks) that does not result in behavioral dysfunction, nor in altered NCAM expression, in wild-type mice. Indeed, while no behavioral alterations were detected in wild-type littermates after subchronic stress, conditional NCAM-deficient mice showed increased immobility in the tail suspension test and deficits in reversal spatial learning in the water maze. These findings indicate that diminished NCAM expression might be a critical vulnerability factor for the development of behavioral alterations by stress and further support a functional involvement of NCAM in stress-induced cognitive and emotional disturbances.

  6. Environmentally Induced Epigenetic Transgenerational Inheritance of Altered SRY Genomic Binding During Gonadal Sex Determination.

    PubMed

    Skinner, Michael K; Bhandari, Ramji K; Haque, M Muksitul; Nilsson, Eric E

    2015-12-01

    A critical transcription factor required for mammalian male sex determination is SRY (sex determining region on the Y chromosome). The expression of SRY in precursor Sertoli cells is one of the initial events in testis development. The current study was designed to determine the impact of environmentally induced epigenetic transgenerational inheritance on SRY binding during gonadal sex determination in the male. The agricultural fungicide vinclozolin and vehicle control (DMSO) exposed gestating females (F0 generation) during gonadal sex determination promoted the transgenerational inheritance of differential DNA methylation in sperm of the F3 generation (great grand-offspring). The fetal gonads in F3 generation males were used to identify potential alterations in SRY binding sites in the developing Sertoli cells. Chromatin immunoprecipitation with an SRY antibody followed by genome-wide promoter tiling array (ChIP-Chip) was used to identify alterations in SRY binding. A total of 81 adjacent oligonucleotide sites and 173 single oligo SRY binding sites were identified to be altered transgenerationally in the Sertoli cell vinclozolin lineage F3 generation males. Observations demonstrate the majority of the previously identified normal SRY binding sites were not altered and the altered SRY binding sites were novel and new additional sites. The chromosomal locations, gene associations and potentially modified cellular pathways were investigated. In summary, environmentally induced epigenetic transgenerational inheritance of germline epimutations appears to alter the cellular differentiation and development of the precursor Sertoli cell SRY binding during gonadal sex determination that influence the developmental origins of adult onset testis disease.

  7. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    NASA Astrophysics Data System (ADS)

    Liu, Hanzhou; Yu, Ming; Deng, Bo; Li, Linfan; Jiang, Haiqing; Li, Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA).

  8. Electrical potentials in bone induced by ultrasound irradiation in the megahertz range

    NASA Astrophysics Data System (ADS)

    Okino, M.; Coutelou, S.; Mizuno, K.; Yanagitani, T.; Matsukawa, M.

    2013-09-01

    Low frequency mechanical studies have reported the contribution of stress-induced electrical potentials to bone metabolism. However, the healing mechanism of bone fractures by low intensity ultrasound is not yet clear. We demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. Electrical potentials were obtained from the output of bovine cortical bone transducers. In the range of 0.7-2.5 MHz, sensitivities of bone transducers were around 1/1000 of a poly (vinylidene fluoride) ultrasonic transducer and did not depend on magnitude and alignment of hydroxyapatite crystallites in bone.

  9. Soft-mold-induced self-construction of polymer patterns under microwave irradiation

    NASA Astrophysics Data System (ADS)

    Ko, Fu-Hsiang; Wu, Chia-Tien; Chen, Mei-Fen; Chen, Jem-Kun; Chu, Tieh-Chi

    2007-05-01

    In this study, the authors used a soft-mold-induced self-construction method to fabricate three-dimensional patterns under microwave irradiation for 1min. The authors estimated the actual pattern growth temperature using a fluorescence probe technique. The temperature at which pattern growth originated was, by necessity, higher than the glass transition temperature of the novolak resist. Electrostatic forces and surface tension effects under the electromagnetic field contributed significantly to the pattern growth, and the use of an antisticking agent allowed easy demolding.

  10. Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements.

    SciTech Connect

    Peng, B.; Locascio, M.; Zapol, P.; Li, S.; Mielke, S. L.; Schatz, G. C.; Espinosa, H. D.; Northwestern Univ.

    2008-01-01

    The excellent mechanical properties of carbon nanotubes are being exploited in a growing number of applications from ballistic armour to nanoelectronics. However, measurements of these properties have not achieved the values predicted by theory due to a combination of artifacts introduced during sample preparation and inadequate measurements. Here we report multiwalled carbon nanotubes with a mean fracture strength >100 GPa, which exceeds earlier observations by a factor of approximately three. These results are in excellent agreement with quantum-mechanical estimates for nanotubes containing only an occasional vacancy defect, and are {approx}80% of the values expected for defect-free tubes. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging was used to directly determine the number of fractured shells and the chirality of the outer shell. Electron irradiation at 200 keV for 10, 100 and 1,800 s led to improvements in the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. Computer simulations also illustrate the effects of various irradiation-induced crosslinking defects on load sharing between the shells.

  11. Irradiation-induced precipitation and mechanical properties of vanadium alloys at <430 C

    SciTech Connect

    Chung, H.M.; Gazda, J.; Smith, D.L.

    1998-09-01

    Recent attention to V-base alloys has focused on the effect of low-temperature (<430 C) irradiation on tensile and impact properties of V-4Cr-4Ti. In previous studies, dislocation channeling, which causes flow localization and severe loss of work-hardening capability, has been attributed to dense, irradiation-induced precipitation of very fine particles. However, efforts to identify the precipitates were unsuccessful until now. In this study, analysis by transmission electron microscopy (TEM) was conducted on unalloyed V, V-5Ti, V-3Ti-1Si, and V-4Cr-4Ti specimens that were irradiated at <430 C in conventional and dynamic helium charging experiments. By means of dark-field imaging and selected-area-diffraction analysis, the characteristic precipitates were identified to be (V,Ti{sub 1{minus}x})(C,O,N). In V-3Ti-1Si, precipitation of (V,Ti{sub 1{minus}x})(C,O,N) was negligible at <430 C, and as a result, dislocation channeling did not occur and work-hardening capability was high.

  12. Atomistic simulation of Er irradiation induced defects in GaN nanowires

    SciTech Connect

    Ullah, M. W. Kuronen, A.; Djurabekova, F.; Nordlund, K.; Stukowski, A.

    2014-09-28

    Classical molecular dynamics simulation was used to irradiate a GaN nanowire with rear-earth erbium (Er). Ten cumulative irradiations were done using an ion energy of 37.5 keV on a 10 × 10 nm²surface area which corresponds to a fluence of 1 × 10¹³ cm⁻². We studied the location and types of defects produced in the irradiation. Er implantation leads to a net positive (expansion) strain in the nanowire and especially at the top region a clear expansion has been observed in the lateral and axial directions. The lattice expansion is due to the hydrostatic strain imposed by a large number of radiation induced defects at the top of the NW. Due to the large surface-to-volume ratio, most of the defects were concentrated at the surface region, which suggests that the experimentally observed yellow luminescence (YL) in ion implanted GaN NWs arises from surface defects. We observed big clusters of point defects and vacancy clusters which are correlated with stable lattice strain and the YL band, respectively.

  13. Microstructural evolution of nuclear grade graphite induced by ion irradiation at high temperature environment

    NASA Astrophysics Data System (ADS)

    Tsai, Shuo-Cheng; Huang, E.-Wen; Kai, Ji-Jung; Chen, Fu-Rong

    2013-03-01

    This study simulates the Wigner Effect of nuclear-grade graphite in a High Temperature Gas-cooled Reactor (HTGR). The graphite was artificially irradiated with 3 MeV C2+ ions to mimic the fast neutron-radiation damage of the HTGR core environment. The irradiation temperatures were controlled between the range of 500-800 °C in a high vacuum environment of 10-7 torr. This high-dosage radiation creates enormous amounts of Frenkel pairs, which induce lattice swelling. These Frenkel vacancies and interstitials generate new strain fields and, hence, store energy in the distorted crystalline structure. The structural integrity of nuclear grade graphite was quantified using high-resolution transmission electron microscopy (HRTEM). The microstructure was estimated by the fast Fourier transform of HRTEM images. Within the samples irradiated with 10 dpa at 600 °C, the d-spacing of {0 0 0 2} expanded from 0.336 nm to 0.396 nm accompanying with the greatest distorted graphite microstructure. The c-axis of graphite swelled approximately 18% and the disorder coefficient was 1.10 ± 0.17 (1/nm). The synchrotron X-ray experimental results, gauged from 500 μm3 volume, suggesting that the ion-implanted graphite only deformed locally and epitaxially. This study also presents possible mechanisms.

  14. Microstructural analysis of ion-irradiation-induced hardening in inconel 718

    NASA Astrophysics Data System (ADS)

    Hashimoto, N.; Hunn, J. D.; Byun, T. S.; Mansur, L. K.

    2003-05-01

    As an assessment for a possible accelerator beam line window material for the US Spallation Neutron Source (SNS) target, performance, radiation-induced hardening and microstructural evolution in Inconel 718 were investigated in both solution annealed (SA) and precipitation hardened (PH) conditions. Irradiations were carried out using 3.5 MeV Fe +, 370 keV He + and 180 keV H + either singly or simultaneously at 200 °C to simulate the damage and He/H production in the SNS target vessel wall. This resulted in systematic hardening in SA Inconel and gradual net softening in the PH material. TEM microstructural analysis showed the hardening was associated with the formation of small loop and faulted loop structures. Helium-irradiated specimens included more loops and cavities than Fe + ion-irradiated specimens. Softening of the PH material was due to dissolution of the γ '/γ ″ precipitates. High doses of helium were implanted in order to study the effect of high retention of gaseous transmutation products. Simultaneous with the hardening and/or softening due to the displacement damage cascade, helium filled cavities produced additional hardening at high concentrations.

  15. Resveratrol ameliorates ionizing irradiation-induced long-term hematopoietic stem cell injury in mice.

    PubMed

    Zhang, Heng; Zhai, Zhibin; Wang, Yueying; Zhang, Junling; Wu, Hongying; Wang, Yingying; Li, Chengcheng; Li, Deguan; Lu, Lu; Wang, Xiaochun; Chang, Jianhui; Hou, Qi; Ju, Zhenyu; Zhou, Daohong; Meng, Aimin

    2013-01-01

    Our recent studies showed that total body irradiation (TBI) induces long-term bone marrow (BM) suppression in part by induction of hematopoietic stem cell (HSC) senescence through NADPH oxidase 4 (NOX4)-derived reactive oxygen species (ROS). Therefore, in this study we examined whether resveratrol (3,5,4'-trihydroxy-trans-stilbene), a potent antioxidant and a putative activator of Sirtuin 1 (Sirt1), can ameliorate TBI-induced long-term BM injury by inhibiting radiation-induced chronic oxidative stress and senescence in HSCs. Our results showed that pretreatment with resveratrol not only protected mice from TBI-induced acute BM syndrome and lethality but also ameliorated TBI-induced long-term BM injury. The latter effect is probably attributable to resveratrol-mediated reduction of chronic oxidative stress in HSCs, because resveratrol treatment significantly inhibited TBI-induced increase in ROS production in HSCs and prevented mouse BM HSCs from TBI-induced senescence, leading to a significant improvement in HSC clonogenic function and long-term engraftment after transplantation. The inhibition of TBI-induced ROS production in HSCs is probably attributable to resveratrol-mediated downregulation of NOX4 expression and upregulation of Sirt1, superoxide dismutase 2 (SOD2), and glutathione peroxidase 1 expression. Furthermore, we showed that resveratrol increased Sirt1 deacetylase activity in BM hematopoietic cells; and Ex527, a potent Sirt1 inhibitor, can attenuate resveratrol-induced SOD2 expression and the radioprotective effect of resveratrol on HSCs. These findings demonstrate that resveratrol can protect HSCs from radiation at least in part via activation of Sirt1. Therefore, resveratrol has the potential to be used as an effective therapeutic agent to ameliorate TBI-induced long-term BM injury.

  16. ALTERED RA SIGNALING IN THE GENESIS OF ETHANOL-INDUCED LIMB DEFECTS

    EPA Science Inventory

    Altered RA Signaling in the Genesis of Ethanol-Induced Limb Defects

    Johnson CS(1), Sulik KK(1,2) Hunter, ES III(3)
    (1) Dept of Cell and Developmental Biology, UNC-Chapel Hill (2) Bowles Center for Alcohol Studies, UNC-CH (3) NHEERL, ORD, US EPA, RTP, NC

    Administr...

  17. Outcome of Children with Hyperventilation-Induced High-Amplitude Rhythmic Slow Activity with Altered Awareness

    ERIC Educational Resources Information Center

    Barker, Alexander; Ng, Joanne; Rittey, Christopher D. C.; Kandler, Rosalind H.; Mordekar, Santosh R.

    2012-01-01

    Hyperventilation-induced high-amplitude rhythmic slow activity with altered awareness (HIHARS) is increasingly being identified in children and is thought to be an age-related non-epileptic electrographic phenomenon. We retrospectively investigated the clinical outcome in 15 children (six males, nine females) with HIHARS (mean age 7y, SD 1y 11mo;…

  18. Changes of amino acid gradients in brain tissues induced by microwave irradiation and other means

    SciTech Connect

    Baxter, C.F.; Parsons, J.E.; Oh, C.C.; Wasterlain, C.G.; Baldwin, R.A. )

    1989-09-01

    Focused microwave irradiation to the head (FMI) has been used extensively by neurochemists for rapid inactivation of enzymatic activity in brain tissues and the preservation, for in vitro analysis, of in vivo substrate concentrations. Periodically the suitability of this technique for regional studies has been questioned. Evidence has now been obtained, on the basis of altered concentration gradients for GABA and taurine from the Substantia Nigra (SN) to an Adjacent Dorsal Area (ADJ), that FMI not only inactivates enzymes, but also facilitates rapid diffusion of small molecules from areas of high concentrations to adjacent areas of lower concentration. To a lesser extent, the implantation of plastic injection cannulas also decreased these concentration gradients. These results offer clear evidence that FMI is ill suited and unreliable for studies designed to map and compare the in vivo regional concentrations of diffusible organic molecules (such as amino acids) in brain tissues. Any invasive technique that compromises membrane barriers is likely to produce smaller similar effects.

  19. Novobiocin treatment reverses radiation-induced alterations in higher-order DNA structure in L5178Y nucleoids

    SciTech Connect

    Kapiszewska, M.; Lange, C.S. )

    1991-09-01

    The authors have studied the effect of novobiocin treatment on radiation-induced damage and its repair in higher-order DNA structure in two mouse leukemia cell lines differing in their radiosensitivity, L5178Y-R (LY-R) and L5178Y-S (LY-S). They used the fluorescent halo technique to measure alterations in the superhelical density and the topological constraints of DNA in LY-R and LY-S nucleoids. The results for untreated cells show that both cell lines reached maximal DNA unwinding at the same concentration of propidium iodide (PI), whereas LY-S nucleoids were less efficient in their ability to rewind their DNA. The loop size did not differ significantly between the cell lines. Incubation of LY-R and LY-S cells with novobiocin at a concentration which does not influence survival (0.1 mM for 45 min), but inhibits DNA synthesis in LY-R cells (by 28%) to a greater extent than in LY-S cells (by 10%), also causes more DNA unwinding in LY-R nucleoids than in LY-S nucleoids. However, a decreased superhelical density was observed in nucleoids from both cell lines. Novobiocin applied before, and present during, irradiation prevents radiation-induced alterations in DNA supercoiling more efficiently in LY-R than in LY-S cells. The presence of novobiocin during the repair period increased DNA rewinding to levels not significantly different from control values in nucleoids from both cell lines.

  20. Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses.

    PubMed

    Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

    2016-11-23

    Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy.

  1. Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses

    PubMed Central

    Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M.; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

    2016-01-01

    Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy. PMID:27886076

  2. Gamma-irradiation and UV-C light-induced lipid peroxidation: a Fourier transform-infrared absorption spectroscopic study.

    PubMed

    Kinder, R; Ziegler, C; Wessels, J M

    1997-05-01

    Fourier transform-infrared spectroscopy of dry, multibilayer films has been used to study gamma-radiation and UV-C light induced lipid peroxidation in 1,2-dilinoleoyl-sn-glycero-3-phosphocholine liposomes. The observed spectral changes were compared with the results obtained from measurement of hydroperoxides, conjugated dienes and to the formation of thiobarbituric acid reactive substances, such as malondialdehyde (MDA) or MDA-like substances. Upon irradiation a decrease in intensity of the asymmetric C - H stretching vibration (va(CH2)) of the isolated cis C = C - H groups (3010 cm-1) was observed. Directly correlated with the decrease of the va(CH2) absorption was a shift of the asymmetric phosphate ester stretching vibration (va(P = O)) towards smaller wavenumbers (1260-->1244 cm-1), indicating that the lipid peroxidation induced molecular alterations in the fatty acid chains influence the packing of the phospholipids in dry multibilayer films. In addition, the formation of a new absorption band at 1693 cm-1 could be detected, the intensity of which was comparable with the formation of thiobarbituric acid reactive substances and, therefore, attributed to the (C = O) stretching of alpha, beta unsaturated aldehydes. Dose-dependent studies using ionizing radiation showed that the decrease of va(CH2) was directly correlated with an increase in absorption of the conjugated dienes at 234 nm and with the formation of hydroperoxides suggesting that the absorption at 3010 cm-1 is solely due to isolated cis C = C - H groups and hence subject to the early stages of the radical chain reaction. UV-C light induced lipid peroxidation revealed a non-linear decrease of I3010, which was directly correlated with the formation of hydroperoxides. The observed early saturation of the conjugated dienes was attributed to an early photodecomposition of the conjugated double bonds.

  3. Cell Cycle Checkpoint Proteins p21 and Hus1 Regulating Intercellular Signaling Induced By Alpha Particle Irradiation

    NASA Astrophysics Data System (ADS)

    Wu, Lijun; Zhao, Ye; Wang, Jun; Hang, Haiying

    In recent years, the attentions for radiation induced bystander effects (RIBE) have been paid on the intercellular signaling events connecting the irradiated and non-irradiated cells. p21 is a member of the Cip/Kip family and plays essential roles in cell cycle progression arrest after cellular irradiation. DNA damage checkpoint protein Hus1 is a member of the Rad9-Rad1-Hus1 complex and functions as scaffold at the damage sites to facilitate the activation of downstream effectors. Using the medium trasfer method and the cells of MEF, MEF (p21-/-), MEF (p21-/-Hus1-/-) as either medium donor or receptor cells, it was found that with 5cGy alpha particle irradiation, the bystander cells showed a significant induction of -H2AX for normal MEFs (p¡0.05). However, the absence of p21 resulted in deficiency in inducing bystander effects. Further results indicated p21 affected the intercellular DNA damage signaling mainly through disrupting the production or release of the damage signals from irradiated cells. When Hus1 and p21 were both knocked out, an obvious induction of -H2AX recurred in bystander cells and the induction of -H2AX was GJIC (gap junction-mediated intercellular communication) dependent, indicating the interrelationship between p21 and Hus1 regulated the production and relay of DNA damage signals from irradiated cells to non-irradiated bystander cells.

  4. Gamma irradiation induces acetylcholine-evoked, endothelium-independent relaxation and activatesk-channels of isolated pulmonary artery of rats

    SciTech Connect

    Eder, Veronique . E-mail: eder@med.univ-tours.fr; Gautier, Mathieu; Boissiere, Julien; Girardin, Catherine; Rebocho, Manuel; Bonnet, Pierre

    2004-12-01

    Purpose: To test the effects of irradiation (R*) on the pulmonary artery (PA). Methods and materials: Isolated PA rings were submitted to gamma irradiation (cesium, 8 Gy/min{sup -1}) at doses of 20 Gy-140 Gy. Rings were placed in an organ chamber, contracted with serotonin (10{sup -4} M 5-hydroxytryptamine [5-HT]), then exposed to acetylcholine (ACh) in incremental concentrations. Smooth muscle cell (SMC) membrane potential was measured with microelectrodes. Results: A high dose of irradiation (60 Gy) increased 5HT contraction by 20%, whereas lower (20 Gy) doses slightly decreased it compared with control. In the absence of the endothelium, 5-HT precontracted rings exposed to 20 Gy irradiation developed a dose-dependent relaxation induced by acetylcholine (EI-ACh) with maximal relaxation of 60 {+-} 17% (n = 13). This was totally blocked by L-NAME (10{sup -4} M), partly by 7-nitro indazole; it was abolished by hypoxia and iberiotoxin, decreased by tetra-ethyl-ammonium, and not affected by free radical scavengers. In irradiated rings, hypoxia induced a slight contraction which was never observed in control rings. No differences in SMC membrane potential were observed between irradiated and nonirradiated PA rings. Conclusion: Irradiation mediates endothelium independent relaxation by a mechanism involving the nitric oxide pathway and K-channels.

  5. Human Apurinic/Apyrimidinic Endonuclease siRNA Inhibits the Angiogenesis Induced by X-Ray Irradiation in Lung Cancer Cells

    PubMed Central

    Gu, Xianqing; Cun, Yanping; Li, Mengxia; Qing, Yi; Jin, Feng; Zhong, Zhaoyang; Dai, Nan; Qian, Chengyuan; Sui, Jiangdong; Wang, Dong

    2013-01-01

    Objective: Radiotherapy is an important and effective treatment method for non-small cell lung cancer (NSCLC). Nonetheless, radiotherapy can alter the expression of proangiogenic molecules and induce angiogenesis. Human apurinic/apyrimidinic endonuclease (APE1) is a multifunctional protein, which has DNA repair and redox function. Our previous studies indicated APE1 is also a crucial angiogenic regulator. Thus, we investigated the effect of APE1 on radiation-induced angiogenesis in lung cancer and its underlying mechanism. Methods: Tumor specimens of 136 patients with NSCLC were obtained from 2003 to 2008. The APE1 and vascular endothelial growth factor (VEGF) expression, as well as microvessel density (MVD) were observed with immunohistochemistry in tumor samples. Human lung adenocarcinoma A549 cells were treated with Ad5/F35-APE1 siRNA and/or irradiation, and then the cells were used for APE1 analysis by Western blot and VEGF analysis by RT-PCR and ELISA. To elucidate the underline mechanism of APE1 on VEGF expression, HIF-1α protein level was determined by Western blot, and the DNA binding activity of HIF-1α was detected by EMSA. Transwell migration assay and capillary-like structure assay were used to observe the migration and capillary-like structure formation ability of human umbilical veins endothelial cells (HUVECs) that were co-cultured with Ad5/F35-APE1 siRNA and (or) irradiation treated A549 cells culture medium. Results: The high expression rates of APE1 and VEGF in NSCLC were 77.94% and 66.18%, respectively. The expressions of APE1 was significantly correlated with VEGF and MVD (r=0.369, r=0.387). APE1 and VEGF high expression were significantly associated with reduced disease free survival (DFS) time. The high expressions of APE1 and VEGF on A549 cells were concurrently induced by X-ray irradiation in a dose-dependent manner. Silencing of APE1 by Ad5/F35-APE1 siRNA significantly decreased DNA binding activity of HIF-1α and suppressed the expression

  6. Ion irradiation induced element-enriched and depleted nanostructures in Zr-Al-Cu-Ni metallic glass

    SciTech Connect

    Chen, H. C.; Liu, R. D.; Yan, L. E-mail: zhouxingtai@sinap.ac.cn; Zhou, X. T. E-mail: zhouxingtai@sinap.ac.cn; Cao, G. Q.; Wang, G.

    2015-07-21

    The microstructural evolution of a Zr-Al-Cu-Ni metallic glass induced by irradiation with Ar ions was investigated. Under ion irradiation, the Cu- and Ni-enriched nanostructures (diameter of 30–50 nm) consisted of crystalline and amorphous structures were formed. Further, Cu- and Ni-depleted nanostructures with diameters of 5–20 nm were also observed. The formation of these nanostructures can be ascribed to the migration of Cu and Ni atoms in the irradiated metallic glass.

  7. Electron-beam irradiation induced conductivity in ZnS nanowires as revealed by in situ transmission electron microscope

    NASA Astrophysics Data System (ADS)

    Liu, Baodan; Bando, Yoshio; Wang, Mingsheng; Zhi, Chunyi; Fang, Xiaosheng; Tang, Chengchun; Mitome, Masanori; Golberg, Dmitri

    2009-08-01

    Electron transport variations in individual ZnS nanowires synthesized through a chemical vapor deposition process were in situ studied in transmission electron microscope under convergent electron-beam irradiation (EBI). It was found that the transport can dramatically be enhanced using proper irradiation conditions. The conductivity mechanism was revealed based on a detailed study of microstructure and composition evolutions under irradiation. EBI-induced Zn-rich domains' appearance and related O doping were mainly responsible for the conductivity improvements. First-principles theoretical calculations additionally indicated that the generation of midbands within a ZnS band gap might also contribute to the improved conductivity.

  8. Radiation-induced effects on murine kidney tumor cells: role in the interaction of local irradiation and immunotherapy.

    PubMed

    Younes, E; Haas, G P; Dezso, B; Ali, E; Maughan, R L; Montecillo, E; Pontes, J E; Hillman, G G

    1995-06-01

    Local tumor irradiation enhances the effect of interleukin-2 (IL-2) therapy in the Renca murine renal adenocarcinoma model. To investigate the mechanism(s) of this interaction, we studied the in vitro and in vivo effects of irradiation on the tumor cells. Tumor cells from in situ irradiated renal tumors had diminished proliferation in vitro. A similar growth inhibition was noted following injection of irradiated Renca cells into naive mice, but this effect could be overcome by injecting more cells. Histologic evaluation of tumors derived from irradiated cells revealed a decrease in mitosis and an increase in multinucleated giant cells, apoptosis and micronecrosis. The presence of irradiated tumor reduced the growth of nonirradiated tumor cells when both were injected into separate flanks of the same animal, suggesting that irradiated tumor cells may trigger a systemic antitumor response. Interleukin-2 therapy given after injection of irradiated tumor cells caused a significant increase in leukocytic infiltrates and micronecrosis. Our findings indicate that radiation directly affects tumor growth and induces a systemic mechanism which could be enhanced by IL-2.

  9. Jeju ground water containing vanadium induced immune activation on splenocytes of low dose γ-rays-irradiated mice.

    PubMed

    Ha, Danbee; Joo, Haejin; Ahn, Ginnae; Kim, Min Ju; Bing, So Jin; An, Subin; Kim, Hyunki; Kang, Kyung-goo; Lim, Yoon-Kyu; Jee, Youngheun

    2012-06-01

    Vanadium, an essential micronutrient, has been implicated in controlling diabetes and carcinogenesis and in impeding reactive oxygen species (ROS) generation. γ-ray irradiation triggers DNA damage by inducing ROS production and causes diminution in radiosensitive immunocytes. In this study, we elucidate the immune activation capacities of Jeju water containing vanadium on immunosuppression caused by γ-ray irradiation, and identify its mechanism using various low doses of NaVO(3). We examined the intracellular ROS generation, DNA damage, cell proliferation, population of splenocytes, and cytokine/antibody profiles in irradiated mice drinking Jeju water for 180 days and in non-irradiated and in irradiated splenocytes both of which were treated with NaVO(3). Both Jeju water and 0.245 μM NaVO(3) attenuated the intracellular ROS generation and DNA damage in splenocytes against γ-ray irradiation. Splenocytes were significantly proliferated by the long-term intake of Jeju water and by 0.245 μM NaVO(3) treatment, and the expansion of B cells accounted for the increased number of splenocytes. Also, 0.245 μM NaVO(3) treatment showed the potency to amplify the production of IFN-γ and total IgG in irradiated splenocytes, which correlated with the expansion of B cells. Collectively, Jeju water containing vanadium possesses the immune activation property against damages caused by γ-irradiation.

  10. Physiological and molecular characterization of the enhanced salt tolerance induced by low-dose gamma irradiation in Arabidopsis seedlings

    SciTech Connect

    Qi, Wencai; Zhang, Liang; Xu, Hangbo; Wang, Lin; Jiao, Zhen

    2014-07-25

    Highlights: • 50-Gy gamma irradiation markedly promotes the seedling growth under salt stress in Arabidopsis. • The contents of H{sub 2}O{sub 2} and MDA are obviously reduced by low-dose gamma irradiation under salt stress. • Low-dose gamma irradiation stimulates the activities of antioxidant enzymes under salt stress. • Proline accumulation is required for the low-gamma-ray-induced salt tolerance. • Low gamma rays differentially regulate the expression of genes related to salt stress. - Abstract: It has been established that gamma rays at low doses stimulate the tolerance to salt stress in plants. However, our knowledge regarding the molecular mechanism underlying the enhanced salt tolerance remains limited. In this study, we found that 50-Gy gamma irradiation presented maximal beneficial effects on germination index and root length in response to salt stress in Arabidopsis seedlings. The contents of H{sub 2}O{sub 2} and MDA in irradiated seedlings under salt stress were significantly lower than those of controls. The activities of antioxidant enzymes and proline levels in the irradiated seedlings were markedly increased compared with the controls. Furthermore, transcriptional expression analysis of selected genes revealed that some components of salt stress signaling pathways were stimulated by low-dose gamma irradiation under salt stress. Our results suggest that gamma irradiation at low doses alleviates the salt stress probably by modulating the physiological responses as well as stimulating the stress signal transduction in Arabidopsis seedlings.

  11. Irradiation-induced impurity segregation and ductile-to-brittle transition temperature shift in high chromium ferritic/martensitic steels

    NASA Astrophysics Data System (ADS)

    Lu, Z.; Faulkner, R. G.; Flewitt, P. E. J.

    2007-08-01

    A model is presented to predict irradiation-induced impurity segregation and its contribution to the ductile-to-brittle transition temperature (DBTT) shift in high chromium ferritic steels. The hardening contribution (dislocation loops, voids and precipitates) is also considered in this study. The predicted results are compared with the experimental DBTT shifts data for irradiated 9Cr1MoVNb and 12Cr1MoVW steels with different grain sizes.

  12. An in situ transmission electron microscopy study of the ion irradiation induced amorphisation of silicon by He and Xe

    DOE PAGES

    Edmondson, P. D.; Abrams, K. J.; Hinks, J. A.; ...

    2015-11-21

    We used transmission electron microscopy with in situ ion irradiation to examine the ion-beam-induced amorphisation of crystalline silicon under irradiation with light (He) and heavy (Xe) ions at room temperature. Analysis of the electron diffraction data reveal the heterogeneous amorphisation mechanism to be dominant in both cases. Moreover, for the differences in the amorphisation curves are discussed in terms of intra-cascade dynamic recovery, and the role of electronic and nuclear loss mechanisms.

  13. DNA Methylation Patterns in Rat Mammary Carcinomas Induced by Pre- and Post-Pubertal Irradiation

    PubMed Central

    Takabatake, Masaru; Blyth, Benjamin J.; Daino, Kazuhiro; Imaoka, Tatsuhiko; Nishimura, Mayumi; Fukushi, Masahiro; Shimada, Yoshiya

    2016-01-01

    Several lines of evidence indicate one’s age at exposure to radiation strongly modifies the risk of radiation-induced breast cancer. We previously reported that rat mammary carcinomas induced by pre- and post-pubertal irradiation have distinct gene expression patterns, but the changes underlying these differences have not yet been characterized. The aim of this investigation was to see if differences in CpG DNA methylation were responsible for the differences in gene expression between age at exposure groups observed in our previous study. DNA was obtained from the mammary carcinomas arising in female Sprague-Dawley rats that were either untreated or irradiated (γ-rays, 2 Gy) during the pre- or post-pubertal period (3 or 7 weeks old). The DNA methylation was analyzed using CpG island microarrays and the results compared to the gene expression data from the original study. Global DNA hypomethylation in tumors was accompanied by gene-specific hypermethylation, and occasionally, by unique tumor-specific patterns. We identified methylation-regulated gene expression candidates that distinguished the pre- and post-pubertal irradiation tumors, but these represented only 2 percent of the differentially expressed genes, suggesting that methylation is not a major or primary mechanism underlying the phenotypes. Functional analysis revealed that the candidate methylation-regulated genes were enriched for stem cell differentiation roles, which may be important in mammary cancer development and worth further investigation. However, the heterogeneity of human breast cancer means that the interpretation of molecular and phenotypic differences should be cautious, and take into account the co-variates such as hormone receptor status and cell-of-origin that may influence the associations. PMID:27711132

  14. Epigenetic alteration to activate Bmp2-Smad signaling in Raf-induced senescence

    PubMed Central

    Fujimoto, Mai; Mano, Yasunobu; Anai, Motonobu; Yamamoto, Shogo; Fukuyo, Masaki; Aburatani, Hiroyuki; Kaneda, Atsushi

    2016-01-01

    AIM: To investigate epigenomic and gene expression alterations during cellular senescence induced by oncogenic Raf. METHODS: Cellular senescence was induced into mouse embryonic fibroblasts (MEFs) by infecting retrovirus to express oncogenic Raf (RafV600E). RNA was collected from RafV600E cells as well as MEFs without infection and MEFs with mock infection, and a genome-wide gene expression analysis was performed using microarray. The epigenomic status for active H3K4me3 and repressive H3K27me3 histone marks was analyzed by chromatin immunoprecipitation-sequencing for RafV600E cells on day 7 and for MEFs without infection. These data for Raf-induced senescence were compared with data for Ras-induced senescence that were obtained in our previous study. Gene knockdown and overexpression were done by retrovirus infection. RESULTS: Although the expression of some genes including secreted factors was specifically altered in either Ras- or Raf-induced senescence, many genes showed similar alteration pattern in Raf- and Ras-induced senescence. A total of 841 commonly upregulated 841 genes and 573 commonly downregulated genes showed a significant enrichment of genes related to signal and secreted proteins, suggesting the importance of alterations in secreted factors. Bmp2, a secreted protein to activate Bmp2-Smad signaling, was highly upregulated with gain of H3K4me3 and loss of H3K27me3 during Raf-induced senescence, as previously detected in Ras-induced senescence, and the knockdown of Bmp2 by shRNA lead to escape from Raf-induced senescence. Bmp2-Smad inhibitor Smad6 was strongly repressed with H3K4me3 loss in Raf-induced senescence, as detected in Ras-induced senescence, and senescence was also bypassed by Smad6 induction in Raf-activated cells. Different from Ras-induced senescence, however, gain of H3K27me3 did not occur in the Smad6 promoter region during Raf-induced senescence. When comparing genome-wide alteration between Ras- and Raf-induced senescence, genes

  15. Utility of Dexrazoxane for the Attenuation of Epirubicin-Induced Genetic Alterations in Mouse Germ Cells

    PubMed Central

    Ahmad, Sheikh F.; Ansaria, Mushtaq A.; Nadeem, Ahmed; Al-Shabanah, Othman A.; Al-Harbi, Mohammed M.; Bakheet, Saleh A.

    2016-01-01

    Dexrazoxane has been approved to treat anthracycline-induced cardiomyopathy and extravasation. However, the effect of dexrazoxane on epirubicin-induced genetic alterations in germ cells has not yet been reported. Thus, the aim of this study was to determine whether dexrazoxane modulates epirubicin-induced genetic damage in the germ cells of male mice. Our results show that dexrazoxane was not genotoxic at the tested doses. Furthermore, it protected mouse germ cells against epirubicin-induced genetic alterations as detected by the reduction in disomic and diploid sperm, spermatogonial chromosomal aberrations, and abnormal sperm heads. The attenuating effect of dexrazoxane was greater at higher dose, indicating a dose-dependent effect. Moreover, sperm motility and count were ameliorated by dexrazoxane pretreatment. Epirubicin induced marked biochemical changes characteristic of oxidative DNA damage including elevated 8-hydroxy-2ʹ-deoxyguanosine levels and reduction in reduced glutathione. Pretreatment of mice with dexrazoxane before epirubicin challenge restored these altered endpoints. We conclude that dexrazoxane may efficiently mitigate the epirubicin insult in male germ cells, and prevent the enhanced risk of abnormal reproductive outcomes and associated health risks. Thus, pretreating patients with dexrazoxane prior to epirubicin may efficiently preserve not only sperm quality but also prevent the transmission of genetic damage to future generations. PMID:27690233

  16. Involvement of SULF2 in y-irradiation-induced invasion and resistance of cancer cells by inducing IL-6 expression.

    PubMed

    Jung, Chan-Hun; Ho, Jin-Nyoung; Park, Jong Kuk; Kim, Eun Mi; Hwang, Sang-Gu; Um, Hong-Duck

    2016-03-29

    Cancer cells that survive radiotherapy often display enhanced invasiveness and resistance to death stimuli. Previous findings have suggested that ionizing radiation (IR) induces such undesirable effects by stimulating the STAT3/Bcl-XL pathway. To identify novel cellular components that mediate these actions of IR, we irradiated lung cancer cells with sublethal doses of y-rays and screened for the induction of IR-responsive genes by microarray analysis. The genes encoding 2 extracellular proteins, SULF2 and IL-6, were found to be upregulated, and these results were confirmed by polymerase chain reactions and western blot analyses. Because the IR-mediated induction of SULF2 was a novel finding, we also confirmed the phenomenon in vivo using xenograft tumors in mice. Analyses of signaling processes revealed that IR induced SULF2 expression via p53, which then promoted IL-6 expression by stabilizing β-catenin, followed by stimulation of the STAT3/Bcl-XL pathway. Consistently, both SULF2 and IL-6 mediated IR-induced invasion and resistance to death stimuli. To investigate whether SULF2 contributes to IR-induced tumor metastasis, we irradiated tumors in mice with sublethal doses of IR. This treatment promoted the entry of tumor cells into the blood stream (intravasation), which was abolished by downregulating SULF2 expression in tumor cells. These results demonstrated that SULF2 can mediate the detrimental effects of IR in vivo. Therefore, SULF2 may be potentially used as a therapeutic and diagnostic target to predict and overcome the malignant effects of IR, particularly in tumors expressing p53 wild-type.

  17. Involvement of SULF2 in γ-irradiation-induced invasion and resistance of cancer cells by inducing IL-6 expression

    PubMed Central

    Jung, Chan-Hun; Ho, Jin-Nyoung; Park, Jong Kuk; Kim, Eun Mi; Hwang, Sang-Gu; Um, Hong-Duck

    2016-01-01

    Cancer cells that survive radiotherapy often display enhanced invasiveness and resistance to death stimuli. Previous findings have suggested that ionizing radiation (IR) induces such undesirable effects by stimulating the STAT3/Bcl-XL pathway. To identify novel cellular components that mediate these actions of IR, we irradiated lung cancer cells with sublethal doses of γ-rays and screened for the induction of IR-responsive genes by microarray analysis. The genes encoding 2 extracellular proteins, SULF2 and IL-6, were found to be upregulated, and these results were confirmed by polymerase chain reactions and western blot analyses. Because the IR-mediated induction of SULF2 was a novel finding, we also confirmed the phenomenon in vivo using xenograft tumors in mice. Analyses of signaling processes revealed that IR induced SULF2 expression via p53, which then promoted IL-6 expression by stabilizing β-catenin, followed by stimulation of the STAT3/Bcl-XL pathway. Consistently, both SULF2 and IL-6 mediated IR-induced invasion and resistance to death stimuli. To investigate whether SULF2 contributes to IR-induced tumor metastasis, we irradiated tumors in mice with sublethal doses of IR. This treatment promoted the entry of tumor cells into the blood stream (intravasation), which was abolished by downregulating SULF2 expression in tumor cells. These results demonstrated that SULF2 can mediate the detrimental effects of IR in vivo. Therefore, SULF2 may be potentially used as a therapeutic and diagnostic target to predict and overcome the malignant effects of IR, particularly in tumors expressing p53 wild-type. PMID:26895473

  18. Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Tsuneda, H.; Matsukawa, S.; Takayanagi, S.; Mizuno, K.; Yanagitani, T.; Matsukawa, M.

    2015-02-01

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity.

  19. A simple assay for the study of human hair follicle damage induced by ionizing irradiation.

    PubMed

    Poeggeler, Burkhard; Bodó, Enikö; Nadrowitz, Roger; Dunst, Juergen; Paus, Ralf

    2010-08-01

    Due to its rapidly proliferating matrix keratinocytes, the hair follicle is highly sensitive to ionizing irradiation (IR)-induced skin damage and thus an instructive and clinically relevant model organ for investigating the effects of IR on rapidly dividing epithelial-mesenchymal interaction systems. Here, we have assessed the impact of IR on organ-cultured human scalp hair follicles. We show that IR significantly inhibits the proliferation and induces apoptosis of hair follicle matrix keratinocytes, disrupts normal hair follicle pigmentation, and upregulates a number of quantitative toxicity and viability markers (oxidative stress indicators, DNA oxidative damage, LDH release). This introduces human hair follicle organ culture as an excellent novel research tool for radiobiology and invites exploitation as a preclinical assay system for testing candidate radioprotectants.

  20. Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    SciTech Connect

    Tsuneda, H.; Matsukawa, S.; Takayanagi, S.; Matsukawa, M.; Mizuno, K.; Yanagitani, T.

    2015-02-16

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity.

  1. Reorientation of the crystalline planes in confined single crystal nickel nanorods induced by heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Misra, Abha; Tyagi, Pawan K.; Rai, Padmnabh; Misra, D. S.; Ghatak, Jay; Satyam, P. V.; Avasthi, D. K.

    2006-08-01

    In a recent letter Tyagi et al. [Appl. Phys. Lett. 86, 253110 (2005)] have reported the special orientation of nickel planes inside multiwalled carbon nanotubes (MWCNTs) with respect to the tube axis. Heavy ion irradiation has been performed with 1.5MeV Au2+ and 100MeV Au7+ ions on these nickel filled MWCNTs at fluences ranging from 1012to1015ions/cm2 at room temperature. Ion-induced modifications have been studied using high-resolution transmission electron microscopy. The diffraction pattern and the lattice imaging showed the presence of ion-induced planar defects on the tube walls and completely amorphized encapsulated nickel nanorods. The results are discussed in terms of thermal spike model.

  2. Low-power laser irradiation inhibits amyloid beta-induced cell apoptosis

    NASA Astrophysics Data System (ADS)

    Zhang, Heng; Wu, Shengnan

    2011-03-01

    The deposition and accumulation of amyloid-β-peptide (Aβ) in the brain are considered a pathological hallmark of Alzheimer's disease(AD). Apoptosis is a contributing pathophysiological mechanism of AD. Low-power laser irradiation (LPLI), a non-damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. Recently, low-power laser irradiation (LPLI) has been applied to moderate AD. In this study, Rat pheochromocytoma (PC12) cells were treated with amyloid beta 25-35 (Aβ25-35) for induction of apoptosis before LPLI treatment. We measured cell viability with CCK-8 according to the manufacture's protocol, the cell viability assays show that low fluence of LPLI (2 J/cm2 ) could inhibit the cells apoptosis. Then using statistical analysis of proportion of apoptotic cells by flow cytometry based on Annexin V-FITC/PI, the assays also reveal that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis. Taken together, we demonstrated that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis, these results directly point to a therapeutic strategy for the treatment of AD through LPLI.

  3. The combined effect of resveratrol and diphenyleneiodonium on irradiation-induced injury to the hematopoietic system.

    PubMed

    Zhang, Junling; Han, Xiaodan; Huang, Song; Lu, Lu; Li, Deguan; Meng, Aimin

    2017-02-01

    Both resveratrol(Res) and diphenyleneiodonium(DPI) have been shown to have radioprotective effects on hematopoietic system injury. However, the cooperative effect of Res and DPI are unknown. In this study, we explored the radioprotective effect of the combination of Res and DPI both in vitro and in vivo. Our results showed that the combined treatment of Res and DPI was more effective in protecting irradiated BMMNCs in terms of cell viability, colony-forming ability, and reconstitution ability in vitro compared with Res or DPI treatment alone. However, in mice, the combination of Res and DPI had no enhanced protection on 4Gy total body irradiation (TBI)-induced hematopoietic system injury, including TBI-induced myelosuppression, induction of the splenic index, and increases in HSC/HPC numbers and the colony-forming ability of BMCs,compared to Res or DPI alone. An exception was the number of BMCs. These studies illustrated the inconsistency between experiments carried out in vitro and in vivo and suggest an interaction between Res or DPI in vivo.

  4. Proteomic Analysis Implicates Dominant Alterations of RNA Metabolism and the Proteasome Pathway in the Cellular Response to Carbon-Ion Irradiation

    PubMed Central

    Xie, Da-Fei; Xie, Yi; Liu, Xiao-Dan; Wang, Qi; Sui, Li; Song, Man; Zhang, Hong; Zhou, Jianhua; Zhou, Ping-Kun

    2016-01-01

    Radiotherapy with heavy ions is considered advantageous compared to irradiation with photons due to the characteristics of the Braggs peak and the high linear energy transfer (LET) value. To understand the mechanisms of cellular responses to different LET values and dosages of heavy ion radiation, we analyzed the proteomic profiles of mouse embryo fibroblast MEF cells exposed to two doses from different LET values of heavy ion 12C. Total proteins were extracted from these cells and examined by Q Exactive with Liquid Chromatography (LC)—Electrospray Ionization (ESI) Tandem MS (MS/MS). Using bioinformatics approaches, differentially expressed proteins with 1.5 or 2.0-fold changes between different dosages of exposure were compared. With the higher the dosage and/or LET of ion irradiation, the worse response the cells were in terms of protein expression. For instance, compared to the control (0 Gy), 771 (20.2%) proteins in cells irradiated at 0.2 Gy of carbon-ion radiation with 12.6 keV/μm, 313 proteins (8.2%) in cells irradiated at 2 Gy of carbon-ion radiation with 12.6 keV/μm, and 243 proteins (6.4%) in cells irradiated at 2 Gy of carbon-ion radiation with 31.5 keV/μm exhibited changes of 1.5-fold or greater. Gene ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Munich Information Center for Protein Sequences (MIPS) analysis, and BioCarta analysis all indicated that RNA metabolic processes (RNA splicing, destabilization and deadenylation) and proteasome pathways may play key roles in the cellular response to heavy-ion irradiation. Proteasome pathways ranked highest among all biological processes associated with heavy carbon-ion irradiation. In addition, network analysis revealed that cellular pathways involving proteins such as Col1a1 and Fn1 continued to respond to high dosages of heavy-ion irradiation, suggesting that these pathways still protect cells against damage. However, pathways such as those involving Ikbkg1 responded

  5. The effect of processing treatments on the radiation-induced ESR signal in the cuticle of irradiated Norwat lobster ( Nephrops norvegicus).

    NASA Astrophysics Data System (ADS)

    Stewart, Eileen M.; Stevenson, M. Hilary; Gray, Richard; McMurray, Cecil H.

    1993-07-01

    Cooked, frozen or chilled whole tails of Norway lobster were either not irradiated or given doses of 1, 2, 3, 4 or 5 kGy using a cobalt 60 source. The cuticle was removed, freeze-dried and ground before determination of the free radical concentration using electron spin resonance (ESR) spectroscopy. The ESR signal strength increased linearly with increasing irradiation dose. In comparison to the chilled samples, cooking before irradiation significantly increased (69%) signal intensity whereas cooking after irradiation decreased (27%) signal strength. Irradiating the samples in the frozen state did not significantly alter the free radical concentration in the cuticle.

  6. Influence of irradiation-induced disorder on the Peierls transition in TTF-TCNQ microdomains

    NASA Astrophysics Data System (ADS)

    Solovyeva, Vita; Cmyrev, Anastasia; Sachser, Roland; Reith, Heiko; Huth, Michael

    2011-09-01

    The combined influence of electron irradiation-induced defects, substrate-induced strain and finite size effects on the electronic transport properties of individual micron-sized thin film growth domains of the organic charge transfer compound tetrathiafulvalene- tetracyanoquinodimethane (TTF-TCNQ) have been studied. The TTF-TCNQ domains have been isolated and electrically contacted by focused ion beam etching and focused ion and electron-beam-induced deposition, respectively. This allowed us to measure the temperature-dependent resistivity and the current-voltage characteristics of individual domains. The dependence of the resistivity on temperature follows a variable-range hopping behaviour which shows a crossover of the exponents as the Peierls transition is approached. The low temperature behaviour is analysed within the segmented rod model of Fogler, Teber and Shklovskii which was developed for charge-ordered quasi one-dimensional electron crystals (Fogler et al 2004 Phys. Rev. B 69 035413). The effect of substrate-induced biaxial strain on the Peierls transition temperature is discussed with regard to its interplay with the defect-induced changes.

  7. Altered autophagic flux enhances inflammatory responses during inflammation-induced preterm labor

    PubMed Central

    Agrawal, Varkha; Jaiswal, Mukesh K.; Mallers, Timothy; Katara, Gajendra K.; Gilman-Sachs, Alice; Beaman, Kenneth D.; Hirsch, Emmet

    2015-01-01

    Cellular organelles and proteins are degraded and recycled through autophagy, a process during which vesicles known as autophagosomes fuse with lysosomes. Altered autophagy occurs in various diseases, but its role in preterm labor (PTL) is unknown. We investigated the role of autophagic flux in two mouse models of PTL compared to controls: 1) inflammation-induced PTL (IPTL), induced by toll-like receptor agonists; and 2) non-inflammation (hormonally)-induced PTL (NIPTL). We demonstrate that the autophagy related genes Atg4c and Atg7 (involved in the lipidation of microtubule-associated protein 1 light chain 3 (LC3) B-I to the autophagosome-associated form, LC3B-II) decrease significantly in uterus and placenta during IPTL but not NIPTL. Autophagic flux is altered in IPTL, as shown by the accumulation of LC3B paralogues and diminishment of lysosome associated membrane protein (LAMP)-1, LAMP-2 and the a2 isoform of V-ATPase (a2V, an enzyme involved in lysosome acidification). These alterations in autophagy are associated with increased activation of NF-κB and proinflammatory cytokines/chemokines in both uterus and placenta. Similar changes are seen in macrophages exposed to TLR ligands and are enhanced with blockade of a2V. These novel findings represent the first evidence of an association between altered autophagic flux and hyper-inflammation and labor in IPTL. PMID:25797357

  8. A single transient episode of hyperammonemia induces long-lasting alterations in protein kinase A.

    PubMed

    Montoliu, Carmina; Piedrafita, Blanca; Serra, Miguel A; del Olmo, Juan A; Rodrigo, José M; Felipo, Vicente

    2007-01-01

    Hepatic encephalopathy in patients with liver disease is associated with poor prognosis. This could be due to the induction by the transient episode of hepatic encephalopathy of long-lasting alterations making patients more susceptible. We show that a single transient episode of hyperammonemia induces long-lasting alterations in signal transduction. The content of the regulatory subunit of the protein kinase dependent on cAMP (PKA-RI) is increased in erythrocytes from cirrhotic patients. This increase is reproduced in rats with portacaval anastomosis and in rats with hyperammonemia without liver failure, suggesting that hyperammonemia is responsible for increased PKA-RI in patients. We analyzed whether there is a correlation between ammonia levels and PKA-RI content in patients. All cirrhotic patients had increased content of PKA-RI. Some of them showed normal ammonia levels but had suffered previous hyperammonemia episodes. This suggested that a single transient episode of hyperammonemia could induce the long-lasting increase in PKA-RI. To assess this, we injected normal rats with ammonia and blood was taken at different times. Ammonia returned to basal levels at 2 h. However, PKA-RI was significantly increased in blood cells from rats injected with ammonia 3 wk after injection. In conclusion, it is shown that a single transient episode of hyperammonemia induces long-lasting alterations in signal transduction both in blood and brain. These alterations may contribute to the poor prognosis of patients suffering hepatic encephalopathy.

  9. Helminth-induced alterations of the gut microbiota exacerbate bacterial colitis.

    PubMed

    Su, C; Su, L; Li, Y; Long, S R; Chang, J; Zhang, W; Walker, W A; Xavier, R J; Cherayil, B J; Shi, H N

    2017-03-29

    Infection with the intestinal helminth parasite Heligmosomoides polygyrus exacerbates the colitis caused by the bacterial enteropathogen Citrobacter rodentium. To clarify the underlying mechanism, we analyzed fecal microbiota composition of control and helminth-infected mice and evaluated the functional role of compositional differences by microbiota transplantation experiments. Our results showed that infection of Balb/c mice with H. polygyrus resulted in significant changes in the composition of the gut microbiota, characterized by a marked increase in the abundance of Bacteroidetes and decreases in Firmicutes and Lactobacillales. Recipients of the gut microbiota from helminth-infected wide-type, but not STAT6-deficient, Balb/c donors had increased fecal pathogen shedding and significant worsening of Citrobacter-induced colitis compared to recipients of microbiota from control donors. Recipients of helminth-altered microbiota also displayed increased regulatory T cells and IL-10 expression. Depletion of CD4(+)CD25(+) T cells and neutralization of IL-10 in recipients of helminth-altered microbiota led to reduced stool C. rodentium numbers and attenuated colitis. These results indicate that alteration of the gut microbiota is a significant contributor to the H. polygyrus-induced exacerbation of C. rodentium colitis. The helminth-induced alteration of the microbiota is Th2-dependent and acts by promoting regulatory T cells that suppress protective responses to bacterial enteropathogens.Mucosal Immunology advance online publication 29 March 2017 doi:10.1038/mi.2017.20.

  10. Metformin ameliorates ionizing irradiation-induced long-term hematopoietic stem cell injury in mice.

    PubMed

    Xu, Guoshun; Wu, Hongying; Zhang, Junling; Li, Deguan; Wang, Yueying; Wang, Yingying; Zhang, Heng; Lu, Lu; Li, Chengcheng; Huang, Song; Xing, Yonghua; Zhou, Daohong; Meng, Aimin

    2015-10-01

    Exposure to ionizing radiation (IR) increases the production of reactive oxygen species (ROS) not only by the radiolysis of water but also through IR-induced perturbation of the cellular metabolism and disturbance of the balance of reduction/oxidation reactions. Our recent studies showed that the increased production of intracellular ROS induced by IR contributes to IR-induced late effects, particularly in the hematopoietic system, because inhibition of ROS production with an antioxidant after IR exposure can mitigate IR-induced long-term bone marrow (BM) injury. Metformin is a widely used drug for the treatment of type 2 diabetes. Metformin also has the ability to regulate cellular metabolism and ROS production by activating AMP-activated protein kinase. Therefore, we examined whether metformin can ameliorate IR-induced long-term BM injury in a total-body irradiation (TBI) mouse model. Our results showed that the administration of metformin significantly attenuated TBI-induced increases in ROS production and DNA damage and upregulation of NADPH oxidase 4 expression in BM hematopoietic stem cells (HSCs). These changes were associated with a significant increase in BM HSC frequency, a considerable improvement in in vitro and in vivo HSC function, and complete inhibition of upregulation of p16(Ink4a) in HSCs after TBI. These findings demonstrate that metformin can attenuate TBI-induced long-term BM injury at least in part by inhibiting the induction of chronic oxidative stress in HSCs and HSC senescence. Therefore, metformin has the potential to be used as a novel radioprotectant to ameliorate TBI-induced long-term BM injury.

  11. Pathogenic mechanisms involved in the hematological alterations of arenavirus-induced hemorrhagic fevers.

    PubMed

    Schattner, Mirta; Rivadeneyra, Leonardo; Pozner, Roberto G; Gómez, Ricardo M

    2013-01-21

    Viral hemorrhagic fevers (VHFs) caused by arenaviruses are acute diseases characterized by fever, headache, general malaise, impaired cellular immunity, eventual neurologic involvement, and hemostatic alterations that may ultimately lead to shock and death. The causes of the bleeding are still poorly understood. However, it is generally accepted that these causes are associated to some degree with impaired hemostasis, endothelial cell dysfunction and low platelet counts or function. In this article, we present the current knowledge about the hematological alterations present in VHF induced by arenaviruses, including new aspects on the underlying pathogenic mechanisms.

  12. Pathogenic Mechanisms Involved in the Hematological Alterations of Arenavirus-induced Hemorrhagic Fevers

    PubMed Central

    Schattner, Mirta; Rivadeneyra, Leonardo; Pozner, Roberto G.; Gómez, Ricardo M.

    2013-01-01

    Viral hemorrhagic fevers (VHFs) caused by arenaviruses are acute diseases characterized by fever, headache, general malaise, impaired cellular immunity, eventual neurologic involvement, and hemostatic alterations that may ultimately lead to shock and death. The causes of the bleeding are still poorly understood. However, it is generally accepted that these causes are associated to some degree with impaired hemostasis, endothelial cell dysfunction and low platelet counts or function. In this article, we present the current knowledge about the hematological alterations present in VHF induced by arenaviruses, including new aspects on the underlying pathogenic mechanisms. PMID:23337384

  13. Crowding-Induced Structural Alterations of Random-Loop Chromosome Model

    NASA Astrophysics Data System (ADS)

    Kim, Jun Soo; Backman, Vadim; Szleifer, Igal

    2011-04-01

    We investigate structural alterations of random-loop polymers due to changes in the crowding condition, as a model to study environmental effects on the structure of chromosome subcompartments. The polymer structure is changed in a nonmonotonic fashion with an increasing density of crowders: condensed at small volume fractions; decondensed at high crowding volume fractions. The nonmonotonic behavior is a manifestation of the nontrivial distance dependence of the depletion interactions. We also show that crowding-induced structural alterations affect the access of binding proteins to the surface of polymer segments and are distinguished from structural changes due to the increased number of specific polymer loops.

  14. Preparation and evaluation of swelling induced-orally disintegrating tablets by microwave irradiation.

    PubMed

    Sano, Syusuke; Iwao, Yasunori; Kimura, Susumu; Itai, Shigeru

    2011-09-15

    A major challenge in the development of orally disintegrating tablets (ODTs) is to achieve a good balance between tablet hardness and disintegration time. In this study, an advanced method was demonstrated to improve these opposing properties in a molded tablet using a one-step procedure that exploits the swelling induced by microwave treatment. Wet molded tablets consisting of the delta form of mannitol and silicon dioxide were prepared and microwave-heated to generate water vapor inside the tablets. This induced either swelling or shrinking of tablets, in the extent of each being dependent on tablet formulation and manufacturing conditions. A two-level full factorial design method was used to evaluate the effects of several variables in formulation and manufacturing conditions on the tablet properties, hardness, disintegration time and change in shape. The variables investigated in this study were: ratio of silicon dioxide in formulation, water volume added in granulation, ratio of water absorbed by silicon dioxide prior to granulation, and microwave irradiation time. Swelling of tablet by microwave irradiation was observed in the batches with high ratio of silicon dioxide and low levels of water volume. The disintegration time was clearly shortened by induction of the swelling, while tablet hardness increased. We demonstrated that the water vapor generated by microwave irradiation promoted a change in the crystalline form of mannitol from delta to beta, and that this may have contributed to an increase in tablet hardness. Additionally, it was found that new solid bridges were formed between the granules in the tablet via the pathway from dissolution of mannitol in water vapor to congelation, resulting in an increase in tablet hardness. Thus, both tablet hardness and disintegration properties of the molded tablets were improved by the proposed one-step method and the appropriate ranges for variables are indicated. In addition, multiple regression modeling was

  15. Cytoplasmic Irradiation Induces Metabolic Shift in Human Small Airway Epithelial Cells via Activation of Pim-1 Kinase.

    PubMed

    Wu, Jinhua; Zhang, Qin; Wuu, Yen-Ruh; Zou, Sirui; Hei, Tom K

    2017-02-07

    The unique cellular and molecular consequences of cytoplasmic damage caused by ionizing radiation were studied using a precision microbeam irradiator. Our results indicated that targeted cytoplasmic irradiation induced metabolic shift from an oxidative to glycolytic phenotype in human small airway epithelial cells (SAE). At 24 h postirradiation, there was an increase in the mRNA expression level of key glycolytic enzymes as well as lactate secretion in SAE cells. Using RNA-sequencing analysis to compare genes that were responsive to cytoplasmic versus nuclear irradiation, we found a glycolysis related gene, Pim-1, was significantly upregulated only in cytoplasmic irradiated SAE cells. Inhibition of Pim-1 activity using the selective pharmaceutic inhibitor Smi-4a significantly reduced the level of lactate production and glucose uptake after cytoplasmic irradiation. In addition, Pim-1 also inhibited AMPK activity, which is a well-characterized negative regulator of glycolysis. Distinct from the glycolysis induced by cytoplasmic irradiation, targeted nuclear irradiation also induced a transient and minimal increase in glycolysis that correlated with increased expression of Hif-1α. In an effort to explore the underline mechanism, we found that inhibition of mitochondria fission using the cell-permeable inhibitor mdivi-1 suppressed the induction of Pim-1, thus confirming Pim-1 upregulation as a downstream effect of mitochondrial dysfunction. Our data show and, for the first time, that cytoplasmic irradiation mediate expression level of Pim-1, which lead to glycolytic shift in SAE cells. Additionally, since glycolysis is frequently linked to cancer cell metabolism, our findings further suggest a role of cytoplasmic damage in promoting neoplastic changes.

  16. Damage and strain in single-layer graphene induced by very-low-energy electron-beam irradiation

    SciTech Connect

    Murakami, Katsuhisa; Fujita, Jun-ichi; Kadowaki, Takuya

    2013-01-28

    From the analysis of the ratio of D peak intensity to G peak intensity in Raman spectroscopy, electron beam irradiation with energies of 100 eV was found to induce damage in single-layer graphene. The damage becomes larger with decreasing electron beam energy. Internal strain in graphene induced by damage under irradiation is further evaluated based on G peak shifts. The dose-dependent internal strain was approximately 2.22% cm{sup 2}/mC at 100 eV and 2.65 Multiplication-Sign 10{sup -2}% cm{sup 2}/mC at 500 eV. The strain induced by the irradiation showed strong dependence on electron energy.

  17. Use of synchrotron medical microbeam irradiation to investigate radiation-induced bystander and abscopal effects in vivo.

    PubMed

    Fernandez-Palomo, Cristian; Bräuer-Krisch, Elke; Laissue, Jean; Vukmirovic, Dusan; Blattmann, Hans; Seymour, Colin; Schültke, Elisabeth; Mothersill, Carmel

    2015-09-01

    The question of whether bystander and abscopal effects are the same is unclear. Our experimental system enables us to address this question by allowing irradiated organisms to partner with unexposed individuals. Organs from both animals and appropriate sham and scatter dose controls are tested for expression of several endpoints such as calcium flux, role of 5HT, reporter assay cell death and proteomic profile. The results show that membrane related functions of calcium and 5HT are critical for true bystander effect expression. Our original inter-animal experiments used fish species whole body irradiated with low doses of X-rays, which prevented us from addressing the abscopal effect question. Data which are much more relevant in radiotherapy are now available for rats which received high dose local irradiation to the implanted right brain glioma. The data were generated using quasi-parallel microbeams at the biomedical beamline at the European Synchrotron Radiation Facility in Grenoble France. This means we can directly compare abscopal and "true" bystander effects in a rodent tumour model. Analysis of right brain hemisphere, left brain and urinary bladder in the directly irradiated animals and their unirradiated partners strongly suggests that bystander effects (in partner animals) are not the same as abscopal effects (in the irradiated animal). Furthermore, the presence of a tumour in the right brain alters the magnitude of both abscopal and bystander effects in the tissues from the directly irradiated animal and in the unirradiated partners which did not contain tumours, meaning the type of signal was different.

  18. Alteration of liver glycopatterns during cirrhosis and tumor progression induced by HBV.

    PubMed

    Qin, Yannan; Zhong, Yaogang; Ma, Tianran; Wu, Fei; Wu, Haoxiang; Yu, Hanjie; Huang, Chen; Li, Zheng

    2016-04-01

    The incidence of hepatocellular carcinoma (HCC) is closely correlated with hepatitis B virus (HBV)-induced liver cirrhosis. Structural changes in the glycans of serum and tissue proteins are reliable indicators of liver damage. However, little is known about the alteration of liver glycopatterns during cirrhosis and tumor progression induced by HBV infection. This study compared the differential expression of liver glycopatterns in 7 sets of normal pericarcinomatous tissues (PCTs), cirrhotic, and tumor tissues from patients with liver cirrhosis and HCC induced by HBV using lectin microarrays. Fluorescence-based lectin histochemistry and lectin blotting were further utilized to validate and assess the expression and distribution of certain glycans in 9 sets of corresponding liver tissue sections. Eight lectins (e.g., Jacalin and AAL) revealed significant difference in cirrhotic tissues versus PCTs. Eleven lectins (e.g., EEL and SJA) showed significant alteration during cirrhotic and tumor progression. The expression of Galα1-3(Fucα1-2)Gal (EEL) and fucosyltransferase 1 was mainly increasing in the cytoplasm of hepatocytes during PCTs-cirrhotic-tumor tissues progression, while the expression of T antigen (ACA and PNA) was decreased sharply in cytoplasm of tumor hepatocytes. Understanding the precision alteration of liver glycopatterns related to the development of hepatitis, cirrhosis, and tumor induced by HBV infection may help elucidate the molecular mechanisms underlying the progression of chronic liver diseases and develop new antineoplastic therapeutic strategies.

  19. Phenobarbital induces alterations in the proteome of hepatocytes and mesenchymal cells of rat livers.

    PubMed

    Klepeisz, Philip; Sagmeister, Sandra; Haudek-Prinz, Verena; Pichlbauer, Melanie; Grasl-Kraupp, Bettina; Gerner, Christopher

    2013-01-01

    Preceding studies on the mode of action of non-genotoxic hepatocarcinogens (NGCs) have concentrated on alterations induced in hepatocytes (HCs). A potential role of non-parenchymal liver cells (NPCs) in NGC-driven hepatocarcinogenesis has been largely neglected so far. The aim of this study is to characterize NGC-induced alterations in the proteome profiles of HCs as well as NPCs. We chose the prototypic NGC phenobarbital (PB) which was applied to male rats for a period of 14 days. The livers of PB-treated rats were perfused by collagenase and the cell suspensions obtained were subjected to density gradient centrifugation to separate HCs from NPCs. In addition, HCs and NPC isolated from untreated animals were treated with PB in vitro. Proteome profiling was done by CHIP-HPLC and ion trap mass spectrometry. Proteome analyses of the in vivo experiments showed many of the PB effects previously described in HCs by other methods, e.g. induction of phase I and phase II drug metabolising enzymes. In NPCs proteins related to inflammation and immune regulation such as PAI-1 and S100-A10, ADP-ribosyl cyclase 1 and to cell migration such as kinesin-1 heavy chain, myosin regulatory light chain RLC-A and dihydropyrimidinase-related protein 1 were found to be induced, indicating major PB effects on these cells. Remarkably, in vitro treatment of HCs and NPCs with PB hardly reproduced the proteome alterations observed in vivo, indicating differences of NGC induced responses of cells at culture conditions compared to the intact organism. To conclude, the present study clearly demonstrated that PB induces proteome alterations not only in HCs but also in NPCs. Thus, any profound molecular understanding on the mode of action of NGCs has to consider effects on cells of the hepatic mesenchyme.

  20. Prenatal caffeine ingestion induces transgenerational neuroendocrine metabolic programming alteration in second generation rats

    SciTech Connect

    Luo, Hanwen; Deng, Zixin; Liu, Lian; Shen, Lang; Kou, Hao; He, Zheng; Ping, Jie; Xu, Dan; Ma, Lu; Chen, Liaobin; Wang, Hui

    2014-02-01

    Our previous studies have demonstrated that prenatal caffeine ingestion induces an increased susceptibility to metabolic syndrome with alterations of glucose and lipid metabolic phenotypes in adult first generation (F1) of intrauterine growth retardation (IUGR) rats, and the underlying mechanism is originated from a hypothalamic–pituitary–adrenal (HPA) axis-associated neuroendocrine metabolic programming alteration in utero. This study aims to investigate the transgenerational effects of this programming alteration in adult second generation (F2). Pregnant Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. Four groups in F2 were set according to the cross-mating between control and caffeine-induced IUGR rats. F2 were subjected to a fortnight ice water swimming stimulus on postnatal month 4, and blood samples were collected before and after stress. Results showed that the majority of the activities of HPA axis and phenotypes of glucose and lipid metabolism were altered in F2. Particularly, comparing with the control group, caffeine groups had an enhanced corticosterone levels after chronic stress. Compared with before stress, the serum glucose levels were increased in some groups whereas the triglyceride levels were decreased. Furthermore, total cholesterol gain rates were enhanced but the high-density lipoprotein-cholesterol gain rates were decreased in most caffeine groups after stress. These transgenerational effects were characterized partially with gender and parental differences. Taken together, these results indicate that the reproductive and developmental toxicities and the neuroendocrine metabolic programming mechanism by prenatal caffeine ingestion have transgenerational effects in rats, which may help to explain the susceptibility to metabolic syndrome and associated diseases in F2. - Highlights: • Caffeine-induced neuroendocrine metabolic programming of HPA has hereditary effect. • Caffeine-induced

  1. Pioglitazone in adult rats reverses immediate postnatal overfeeding-induced metabolic, hormonal, and inflammatory alterations.

    PubMed

    Boullu-Ciocca, S; Tassistro, V; Dutour, A; Grino, M

    2015-12-01

    Immediate postnatal overfeeding in rats, obtained by reducing the litter size, results in early-onset obesity. Such experimental paradigm programs overweight, insulin resistance, dyslipidemia, increased adipose glucocorticoid metabolism [up-regulation of glucocorticoid receptor (GR) and 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1)], and overexpression of proinflammatory cytokines in mesenteric adipose tissue (MAT) in adulthood. We studied the effects of pioglitazone, a PPARγ agonist, treatment on the above-mentioned overfeeding-induced alterations. Nine-month-old rats normofed or overfed during the immediate postnatal period were given pioglitazone (3 mg/kg/day) for 6 weeks. Pioglitazone stimulated weight gain and induced a redistribution of adipose tissue toward epididymal location with enhanced plasma adiponectin. Treatment normalized postnatal overfeeding-induced metabolic alterations (increased fasting insulinemia and free fatty acids) and mesenteric overexpression of GR, 11β-HSD11, CD 68, and proinflammatory cytokines mRNAs, including plasminogen-activator inhibitor type 1. Mesenteric GR mRNA levels correlated positively with mesenteric proinflammatory cytokines mRNA concentrations. In vitro incubation of MAT obtained from overfed rats demonstrated that pioglitazone induced a down-regulation of GR gene expression and normalized glucocorticoid-induced stimulation of 11β-HSD1 and plasminogen-activator inhibitor type 1 mRNAs. Our data show for the first time that the metabolic, endocrine, and inflammatory alterations induced by early-onset postnatal obesity can be reversed by pioglitazone at the adulthood. They demonstrate that pioglitazone, in addition to its well-established effect on adipose tissue redistribution and adiponectin secretion, reverses programing-induced adipose GR, 11β-HSD1, and proinflammatory cytokines overexpression, possibly through a GR-dependent mechanism.

  2. Curcumin Attenuates Gentamicin-Induced Kidney Mitochondrial Alterations: Possible Role of a Mitochondrial Biogenesis Mechanism.

    PubMed

    Negrette-Guzmán, Mario; García-Niño, Wylly Ramsés; Tapia, Edilia; Zazueta, Cecilia; Huerta-Yepez, Sara; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; Aparicio-Trejo, Omar Emiliano; Madero, Magdalena; Pedraza-Chaverri, José

    2015-01-01

    It has been shown that curcumin (CUR), a polyphenol derived from Curcuma longa, exerts a protective effect against gentamicin- (GM-) induced nephrotoxicity in rats, associated with a preservation of the antioxidant status. Although mitochondrial dysfunction is a hallmark in the GM-induced renal injury, the role of CUR in mitochondrial protection has not been studied. In this work, LLC-PK1 cells were preincubated 24 h with CUR and then coincubated 48 h with CUR and 8 mM GM. Treatment with CUR attenuated GM-induced drop in cell viability and led to an increase in nuclear factor (erythroid-2)-related factor 2 (Nrf2) nuclear accumulation and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) cell expression attenuating GM-induced losses in these proteins. In vivo, Wistar rats were injected subcutaneously with GM (75 mg/Kg/12 h) during 7 days to develop kidney mitochondrial alterations. CUR (400 mg/Kg/day) was administered orally 5 days before and during the GM exposure. The GM-induced mitochondrial alterations in ultrastructure and bioenergetics as well as decrease in activities of respiratory complexes I and IV and induction of calcium-dependent permeability transition were mostly attenuated by CUR. Protection of CUR against GM-induced nephrotoxicity could be in part mediated by maintenance of mitochondrial functions and biogenesis with some participation of the nuclear factor Nrf2.

  3. Microcystin-LR and Cylindrospermopsin Induced Alterations in Chromatin Organization of Plant Cells

    PubMed Central

    Máthé, Csaba; M-Hamvas, Márta; Vasas, Gábor

    2013-01-01

    Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-induced changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins induce the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister chromatid segregation during mitosis. Thus, MCY and CYN are probably inducing alterations of chromosome number. MCY induces programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR induces histone H3 hyperphosphorylation leading to incomplete chromatid segregation and the formation of micronuclei. CYN induces the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization. PMID:24084787

  4. Curcumin Attenuates Gentamicin-Induced Kidney Mitochondrial Alterations: Possible Role of a Mitochondrial Biogenesis Mechanism

    PubMed Central

    Negrette-Guzmán, Mario; García-Niño, Wylly Ramsés; Tapia, Edilia; Zazueta, Cecilia; Huerta-Yepez, Sara; León-Contreras, Juan Carlos; Hernández-Pando, Rogelio; Aparicio-Trejo, Omar Emiliano; Madero, Magdalena; Pedraza-Chaverri, José

    2015-01-01

    It has been shown that curcumin (CUR), a polyphenol derived from Curcuma longa, exerts a protective effect against gentamicin- (GM-) induced nephrotoxicity in rats, associated with a preservation of the antioxidant status. Although mitochondrial dysfunction is a hallmark in the GM-induced renal injury, the role of CUR in mitochondrial protection has not been studied. In this work, LLC-PK1 cells were preincubated 24 h with CUR and then coincubated 48 h with CUR and 8 mM GM. Treatment with CUR attenuated GM-induced drop in cell viability and led to an increase in nuclear factor (erythroid-2)-related factor 2 (Nrf2) nuclear accumulation and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) cell expression attenuating GM-induced losses in these proteins. In vivo, Wistar rats were injected subcutaneously with GM (75 mg/Kg/12 h) during 7 days to develop kidney mitochondrial alterations. CUR (400 mg/Kg/day) was administered orally 5 days before and during the GM exposure. The GM-induced mitochondrial alterations in ultrastructure and bioenergetics as well as decrease in activities of respiratory complexes I and IV and induction of calcium-dependent permeability transition were mostly attenuated by CUR. Protection of CUR against GM-induced nephrotoxicity could be in part mediated by maintenance of mitochondrial functions and biogenesis with some participation of the nuclear factor Nrf2. PMID:26345660

  5. Metabolic alterations by indoxyl sulfate in skeletal muscle induce uremic sarcopenia in chronic kidney disease

    PubMed Central

    Sato, Emiko; Mori, Takefumi; Mishima, Eikan; Suzuki, Arisa; Sugawara, Sanae; Kurasawa, Naho; Saigusa, Daisuke; Miura, Daisuke; Morikawa-Ichinose, Tomomi; Saito, Ritsumi; Oba-Yabana, Ikuko; Oe, Yuji; Kisu, Kiyomi; Naganuma, Eri; Koizumi, Kenji; Mokudai, Takayuki; Niwano, Yoshimi; Kudo, Tai; Suzuki, Chitose; Takahashi, Nobuyuki; Sato, Hiroshi; Abe, Takaaki; Niwa, Toshimitsu; Ito, Sadayoshi

    2016-01-01

    Sarcopenia is associated with increased morbidity and mortality in chronic kidney disease (CKD). Pathogenic mechanism of skeletal muscle loss in CKD, which is defined as uremic sarcopenia, remains unclear. We found that causative pathological mechanism of uremic sarcopenia is metabolic alterations by uremic toxin indoxyl sulfate. Imaging mass spectrometry revealed indoxyl sulfate accumulated in muscle tissue of a mouse model of CKD. Comprehensive metabolomics revealed that indoxyl sulfate induces metabolic alterations such as upregulation of glycolysis, including pentose phosphate pathway acceleration as antioxidative stress response, via nuclear factor (erythroid-2-related factor)-2. The altered metabolic flow to excess antioxidative response resulted in downregulation of TCA cycle and its effected mitochondrial dysfunction and ATP shortage in muscle cells. In clinical research, a significant inverse association between plasma indoxyl sulfate and skeletal muscle mass in CKD patients was observed. Our results indicate that indoxyl sulfate is a pathogenic factor for sarcopenia in CKD. PMID:27830716

  6. DNA demethylation caused by 5-Aza-2′-deoxycytidine induces mitotic alterations and aneuploidy

    PubMed Central

    Lentini, Laura; Cilluffo, Danilo; Di Leonardo, Aldo

    2016-01-01

    Aneuploidy, the unbalanced number of chromosomes in a cell, is considered a prevalent form of genetic instability and is largely acknowledged as a condition implicated in tumorigenesis. Epigenetic alterations like DNA hypomethylation have been correlated with cancer initiation/progression. Furthermore, a growing body of evidence suggests the involvement of epigenome-wide disruption as a cause of global DNA hypomethylation in aneuploidy generation. Here, we report that the DNA hypomethylating drug 5-aza-2′-deoxycytidine (DAC), affects the correct ploidy of nearly diploid HCT-116 human cells by altering the methylation pattern of the chromosomes. Specifically, we show that a DAC-induced reduction of 5-Methyl Cytosine at the pericentromeric region of chromosomes correlates with aneuploidy and mitotic defects. Our results suggest that DNA hypomethylation leads to aneuploidy by altering the DNA methylation landscape at the centromere that is necessary to ensure proper chromosomes segregation by recruiting the proteins necessary to build up a functional kinetochore. PMID:26771138

  7. Metabolic alterations induced in cultured skeletal muscle by stretch-relaxation activity

    NASA Technical Reports Server (NTRS)

    Hatfaludy, Sophia; Shansky, Janet; Vandenburgh, Herman H.

    1989-01-01

    Muscle cells differentiated in vitro are repetitively stretched and relaxed in order to determine the presence of short- and long-term alterations occurring in glucose uptake and lactate efflux that are similar to the metabolic alterations occurring in stimulated organ-cultured muscle and in vivo skeletal muscle during the active state. It is observed that whereas mechanical stimulation increases these metabolic parameters within 4-6 h of starting activity, unstimulated basal rates in control cultures also increase during this period of time, and by 8 h, their rates have reached or exceeded the rates in continuously stimulated cells. Measurements of these parameters in media of different compositions show that activity-induced long-term alterations in the parameters occur independently of growth factors in serium and embryo extracts.

  8. Dart model for irradiation-induced swelling of dispersion fuel elements including aluminum-fuel interaction

    SciTech Connect

    Rest, J.; Hofman, G.L.

    1997-06-01

    The Dispersion Analysis Research Tool (DART) contains models for fission-gas induced fuel swelling, interaction of fuel with the matrix aluminum, resultant reaction-product swelling, and calculation of the stress gradient within the fuel particle. The effects of an aluminide shell on fuel particle swelling are evaluated. Validation of the model is demonstrated by a comparison of DART calculations of fuel swelling of U{sub 3}SiAl-Al and U{sub 3}Si{sub 2}-Al for various dispersion fuel element designs with the data. DART results are compared with data for fuel swelling Of U{sub 3}SiAl-Al in plate, tube, and rod configurations as a function of fission density. Plate and tube calculations were performed at a constant fuel temperature of 373 K and 518 K, respectively. An irradiation temperature of 518 K results in a calculated aluminide layer thickness for the Russian tube that is in the center of the measured range (16 {mu}m). Rod calculations were performed with a temperature gradient across the rod characterized by surface and central temperatures of 373 K and 423 K, respectively. The effective yield stress of irradiated Al matrix material and the aluminide was determined by comparing the results of DART calculations with postirradiation immersion volume measurement of U{sub 3}SiAl plates. The values for the effective yield stress were used in all subsequent simulations. The lower calculated fuel swelling in the rod-type element is due to an assumed biaxial stress state. Fuel swelling in plates results in plate thickness increase only. Likewise, in tubes, only the wall thickness increases. Irradiation experiments have shown that plate-type dispersion fuel elements can develop blisters or pillows at high U-235 burnup when fuel compounds exhibiting breakaway swelling are used at moderate to high fuel volume fractions. DART-calculated interaction layer thickness and fuel swelling follows the trends of the observations. 3 refs., 2 figs.

  9. The effect of sunscreen on skin elastase activity induced by ultraviolet-A irradiation.

    PubMed

    Tsukahara, Kazue; Moriwaki, Shigeru; Hotta, Mitsuyuki; Fujimura, Tsutomu; Sugiyama-Nakagiri, Yoriko; Sugawara, Satoshi; Kitahara, Takashi; Takema, Yoshinori

    2005-12-01

    It has been reported that application of sunscreens prevents the photoaging of skin in animal models and in humans. We irradiated the dorsal skin of hairless mice with ultraviolet-A (UVA), and investigated the effects of sunscreens on skin elastase activity and on skin properties. Six-week-old female HR/ICR hairless mice were used in these experiments. After being treated with either a UVA sunscreen (also containing ultraviolet-B (UVB) sunscreen to eliminate any slight UVB in the UVA lamps; Protection Factor of UVA (PFA)=6, Sun Protection Factor (SPF)=20) or a vehicle, the dorsal skins of mice were irradiated with the UVA lamps at 22.3 J/cm(2)/d, 5 times a week. At the end of 15 weeks skin properties were evaluated and elastase activities were measured. In the vehicle control group, UVA irradiation increased the brightness and yellowing of the skin, decreased the water content of the stratum corneum, increased skin thickness, decreased skin elasticity, increased skin elastase activity, and decreased the ability of the skin to recover in a pinch test, as compared to an unirradiated group. All these differences were statistically significant. In the UVA sunscreen group, both the UVA induced skin damage and the increase in skin elastase activity were significantly inhibited, as compared to the vehicle group. However, as compared to the unirradiated group, skin elastase activity was significantly increased and immediate extensibility of skin (Ue) was significantly decreased, thereby indicating that the UVA sunscreen did not prevent photoaging to the same level as the unirradiated group. These results suggest the partial efficacy of the topical photoprotection from UVA by the sunscreen in inhibiting elastase activation, and also suggest the possibility of reducing photoaging.

  10. Stimulation of hematopoietic stem cells by interferon inducer in nonhuman primates receiving fractionated total body irradiation

    SciTech Connect

    Lvovsky, E.A.; Levine, P.H.; Bengali, Z.; Leiseca, S.A.; Cicmanec, J.L.; Robinson, J.E.; Bautro, N.; Levy, H.B.; Scott, R.M.

    1982-10-01

    Interferon response and hematopoietic stem cells (spleen colony forming units-CFU-S) were studied in rhesus monkeys subjected to fractionated total body irradiation (FTBI). An interferon inducer, a nuclease resistant complex of polyinosinic-polycytidylic acid with poly-L-lysine and carboxmethylcellulose(-poly(ICLC)) was used. Poly(ICLC) at 3.75 mg/m/sup 2/ was given I.V. to 7 monkeys, 5 of which, starting 24 hours later, received 50 rad of 4 MV X rays twice a week for 2.5 weeks (total of 250 rad). Another group of 4 monkeys received FTBI only. Although the initial interferon response was similar in both groups treated with poly(ICLC)-800 international units (IU), the animals receiving FTBI showed reduced interferon levels after 100 rad. These animals, however, did not develop the hyporesponsiveness to subsequent poly(ICLC) injections that was observed in non-irradiated monkeys. Stabile interferon response (30-100 IU) in the FTBI group paralleled the prolonged persistence of the drug in their serum. Bone marrow (BM) aspirates from animals receiving FTBI and poly(ICLC) contained more CFU-S per 10/sup 6/ nucleated cells than those treated with poly(ICLC) alone or FTBI alone. FTBI with and without poly(ICLC) led to thrombocytopenia and leukopenia. Lower white blood cell (WBC) count was found in irradiated animals treated with poly(ICLC). Partial alopecia was observed in animals receiving poly(ICLC). Two animals--one in the poly(ICLC) and FTBI group and the other receiving FTBI alone, died with thrombocytopenia and leukopenia.

  11. Stimulation of hematopoietic stem cells by interferon inducer in nonhuman primates receiving fractionated total body irradiation

    SciTech Connect

    Lvovsky, E.A.; Levine, P.H.; Bengali, Z.; Leiseca, S.A.; Cicmanec, J.L.; Robinson, J.E.; Bautro, N.; Levy, H.B.; Scott, R.M.

    1982-10-01

    Interferon response and hematopoietic stem cells (spleen colony forming units--CFU-S) were studied in rhesus monkeys subjected to fractionated total body irradiation (FTBI). An interferon inducer, a nuclease resistant complex of polyinosinic-polycytidylic acid with poly-L-lysine and carboxmethylcellulose(-poly(ICLC)) was used. Poly(ICLC) at 3.75 mg/m/sup 2/ was given I.V. to 7 monkeys, 5 of which, starting 24 hours later, received 50 rad of 4 MV X rays twice a week at 2.5 weeks (total of 250 rad). Another group of 4 monkeys received FTBI only. Although the initial interferon response was similar in both groups treated wih poly(ICLC)--800 international units (IU), the animals that receiving FTBI showed reduced interferon levels after 100 rad. These animals, however, did not develop the hyporesponsiveness to subsequent poly(ICLC) injections that was observed in non-irradiated monkeys. Stabile interferon response (30-100 IU) in the FTBI group paralleled the prolonged persistence of the drug in their serum. Bone marrow (BM) aspirates from animals receiving FTBI and poly(ICLC) contained more CFU-S per 10/sup 6/ nucleated cells than those treated with poly(ICLC) along or FTBI with and without poly(ICLC) lead to thrombocytopenia and leukopenia. Lower white blood cell (WBC) count was found in irradiated animals treated with poly(ICLC). Partial alopecia was observed in animals receiving poly(ICLC). Two animals--one in the poly(ICLC) and FTBI group and the other receiving FTBI along, died with thrombocytopenia and leukopenia.

  12. Hyperoxia, but not thoracic X-irradiation, potentiates bleomycin- and cyclophosphamide-induced lung damage in mice

    SciTech Connect

    Hakkinen, P.J.; Whiteley, J.W.; Witschi, H.R.

    1982-08-01

    The intraperitoneal administration of cyclophosphamide or bleomycin to BALB/c mice resulted in lung cell damage followed by cellular proliferation, which was quantitated by measuring the increase in thymidine incorporation into pulmonary DNA. We have previously shown that administration of the antioxidant butylated hydroxytoluene produces lung damage that can be potentiated by both hyperoxia and thoracic X-irradiation. In the present study we show that hyperoxic exposure also potentiates bleomycin- and cyclophosphamide-induced acute lung damage. However, thoracic X-irradiation does not potentiate bleomycin- and cyclophosphamide-induced lung toxicity.

  13. Nanopatterns induced by pulsed laser irradiation on the surface of an Fe-Al alloy and their magnetic properties

    SciTech Connect

    Yoshida, Yutaka; Oosawa, Kazuya; Watanabe, Seiichi; Kaiju, Hideo; Kondo, Kenji; Ishibashi, Akira; Yoshimi, Kyosuke

    2013-05-06

    We have studied nanopatterns induced by nanosecond pulsed laser irradiation on (111) plane surfaces of a polycrystalline iron-aluminum alloy and evaluated their magnetic properties. Multiple nanosecond pulsed laser irradiation induces a wavelength-dependent surface transformation of the lattice structure from a B2-type to a supersaturated body centered cubic lattice. The selective formation of surface nanopatterns consisting of holes, stripes, polygonal networks, and dot-like nanoprotrusions can be observed. Furthermore, focused magneto-optical Kerr effect measurements reveal that the magnetic properties of the resultant nanostructured region changes from a paramagnetic to a ferromagnetic phase in accordance with the number of laser pulses.

  14. IL-4 Inhibits IL-1β-Induced Depressive-Like Behavior and Central Neurotransmitter Alterations.

    PubMed

    Park, Hyun-Jung; Shim, Hyun-Soo; An, Kyungeh; Starkweather, Angela; Kim, Kyung Soo; Shim, Insop

    2015-01-01

    It has been known that activation of the central innate immune system or exposure to stress can disrupt balance of anti-/proinflammatory cytokines. The aim of the present study was to investigate the role of pro- and anti-inflammatory cytokines in the modulation of depressive-like behaviors, the hormonal and neurotransmitter systems in rats. We investigated whether centrally administered IL-1β is associated with activation of CNS inflammatory pathways and behavioral changes and whether treatment with IL-4 could modulate IL-1β-induced depressive-like behaviors and central neurotransmitter systems. Infusion of IL-4 significantly decreased IL-1β-induced anhedonic responses and increased social exploration and total activity. Treatment with IL-4 markedly blocked IL-1β-induced increase in PGE2 and CORT levels. Also, IL-4 reduced IL-1β-induced 5-HT levels by inhibiting tryptophan hydroxylase (TPH) mRNA and activating serotonin transporter (SERT) in the hippocampus, and levels of NE were increased by activating tyrosine hydroxylase (TH) mRNA expression. These results demonstrate that IL-4 may locally contribute to the regulation of noradrenergic and serotonergic neurotransmission and may inhibit IL-1β-induced behavioral and immunological changes. The present results suggest that IL-4 modulates IL-1β-induced depressive behavior by inhibiting IL-1β-induced central glial activation and neurotransmitter alterations. IL-4 reduced central and systemic mediatory inflammatory activation, as well as reversing the IL-1β-induced alterations in neurotransmitter levels. The present findings contribute a biochemical pathway regulated by IL-4 that may have therapeutic utility for treatment of IL-1β-induced depressive behavior and neuroinflammation which warrants further study.

  15. IL-4 Inhibits IL-1β-Induced Depressive-Like Behavior and Central Neurotransmitter Alterations

    PubMed Central

    Park, Hyun-Jung; Shim, Hyun-Soo; An, Kyungeh; Starkweather, Angela; Kim, Kyung Soo; Shim, Insop

    2015-01-01

    It has been known that activation of the central innate immune system or exposure to stress can disrupt balance of anti-/proinflammatory cytokines. The aim of the present study was to investigate the role of pro- and anti-inflammatory cytokines in the modulation of depressive-like behaviors, the hormonal and neurotransmitter systems in rats. We investigated whether centrally administered IL-1β is associated with activation of CNS inflammatory pathways and behavioral changes and whether treatment with IL-4 could modulate IL-1β-induced depressive-like behaviors and central neurotransmitter systems. Infusion of IL-4 significantly decreased IL-1β-induced anhedonic responses and increased social exploration and total activity. Treatment with IL-4 markedly blocked IL-1β-induced increase in PGE2 and CORT levels. Also, IL-4 reduced IL-1β-induced 5-HT levels by inhibiting tryptophan hydroxylase (TPH) mRNA and activating serotonin transporter (SERT) in the hippocampus, and levels of NE were increased by activating tyrosine hydroxylase (TH) mRNA expression. These results demonstrate that IL-4 may locally contribute to the regulation of noradrenergic and serotonergic neurotransmission and may inhibit IL-1β-induced behavioral and immunological changes. The present results suggest that IL-4 modulates IL-1β-induced depressive behavior by inhibiting IL-1β-induced central glial activation and neurotransmitter alterations. IL-4 reduced central and systemic mediatory inflammatory activation, as well as reversing the IL-1β-induced alterations in neurotransmitter levels. The present findings contribute a biochemical pathway regulated by IL-4 that may have therapeutic utility for treatment of IL-1β-induced depressive behavior and neuroinflammation which warrants further study. PMID:26417153

  16. Hypofractionated Irradiation Has Immune Stimulatory Potential and Induces a Timely Restricted Infiltration of Immune Cells in Colon Cancer Tumors

    PubMed Central

    Frey, Benjamin; Rückert, Michael; Weber, Julia; Mayr, Xaver; Derer, Anja; Lotter, Michael; Bert, Christoph; Rödel, Franz; Fietkau, Rainer; Gaipl, Udo S.

    2017-01-01

    In addition to locally controlling the tumor, hypofractionated radiotherapy (RT) particularly aims to activate immune cells in the RT-modified microenvironment. Therefore, we examined whether hypofractionated RT can activate dendritic cells (DCs), induce immune cell infiltration in tumors, and how the chronology of immune cell migration into tumors occurs to gain knowledge for future definition of radiation breaks and inclusion of immunotherapy. Colorectal cancer treatments offer only limited survival benefit, and immunobiological principles for additional therapies need to be explored with preclinical models. The impact of hypofractionated RT on CT26 colon cancer tumor cell death, migration of DCs toward supernatants (SN) of tumor cells, and activation of DCs by SN were analyzed. The subcutaneous tumor of a BALB/c-CT26 mouse model was locally irradiated with 2 × 5 Gy, the tumor volume was monitored, and the infiltration of immune cells in the tumor was determined by flow cytometry daily. Hypofractionated RT induced a mixture of apoptotic and necrotic CT26 cells, which is known to be in particular immunogenic. DCs that migrated toward SN of CT26 cells particularly upregulated the activation markers CD80 and CD86 when in contact with SN of irradiated tumor cells. After hypofractionated RT, the tumor outgrowth was significantly retarded and in the irradiated tumors an increased infiltration of macrophages (CD11bhigh/F4-80+) and DCs (MHC-II+), but only between day 5 and 10 after the first irradiation, takes place. While CD4+ T cells migrated into non-irradiated and irradiated tumors, CD8+ T cells were only found in tumors that had been irradiated and they were highly increased at day 8 after the first irradiation. Myeloid-derived suppressor cells and regulatory T cells show regular turnover in irradiated and non-irradiated tumors. Tumor cell-specific anti-IgM antibodies were enhanced in the serum of animals with irradiated tumors. We conclude that

  17. Hypofractionated Irradiation Has Immune Stimulatory Potential and Induces a Timely Restricted Infiltration of Immune Cells in Colon Cancer Tumors.

    PubMed

    Frey, Benjamin; Rückert, Michael; Weber, Julia; Mayr, Xaver; Derer, Anja; Lotter, Michael; Bert, Christoph; Rödel, Franz; Fietkau, Rainer; Gaipl, Udo S

    2017-01-01

    In addition to locally controlling the tumor, hypofractionated radiotherapy (RT) particularly aims to activate immune cells in the RT-modified microenvironment. Therefore, we examined whether hypofractionated RT can activate dendritic cells (DCs), induce immune cell infiltration in tumors, and how the chronology of immune cell migration into tumors occurs to gain knowledge for future definition of radiation breaks and inclusion of immunotherapy. Colorectal cancer treatments offer only limited survival benefit, and immunobiological principles for additional therapies need to be explored with preclinical models. The impact of hypofractionated RT on CT26 colon cancer tumor cell death, migration of DCs toward supernatants (SN) of tumor cells, and activation of DCs by SN were analyzed. The subcutaneous tumor of a BALB/c-CT26 mouse model was locally irradiated with 2 × 5 Gy, the tumor volume was monitored, and the infiltration of immune cells in the tumor was determined by flow cytometry daily. Hypofractionated RT induced a mixture of apoptotic and necrotic CT26 cells, which is known to be in particular immunogenic. DCs that migrated toward SN of CT26 cells particularly upregulated the activation markers CD80 and CD86 when in contact with SN of irradiated tumor cells. After hypofractionated RT, the tumor outgrowth was significantly retarded and in the irradiated tumors an increased infiltration of macrophages (CD11b(high)/F4-80(+)) and DCs (MHC-II(+)), but only between day 5 and 10 after the first irradiation, takes place. While CD4(+) T cells migrated into non-irradiated and irradiated tumors, CD8(+) T cells were only found in tumors that had been irradiated and they were highly increased at day 8 after the first irradiation. Myeloid-derived suppressor cells and regulatory T cells show regular turnover in irradiated and non-irradiated tumors. Tumor cell-specific anti-IgM antibodies were enhanced in the serum of animals with irradiated tumors. We conclude that

  18. Respiration Induced Heart Motion and Indications of Gated Delivery for Left-Sided Breast Irradiation

    SciTech Connect

    Qi, X. Sharon; Hu, Angela; Wang Kai; Newman, Francis; Crosby, Marcus; Hu Bin; White, Julia; Li, X. Allen

    2012-04-01

    Purpose: To investigate respiration-induced heart motion for left-sided breast irradiation using a four-dimensional computed tomography (4DCT) technique and to determine novel indications to assess heart motion and identify breast patients who may benefit from a gated treatment. Methods and Materials: Images of 4DCT acquired during free breathing for 20 left-sided breast cancer patients, who underwent whole breast irradiation with or without regional nodal irradiation, were analyzed retrospectively. Dose distributions were reconstructed in the phases of 0%, 20%, and 50%. The intrafractional heart displacement was measured in three selected transverse CT slices using D{sub LAD} (the distance from left ascending aorta to a fixed line [connecting middle point of sternum and the body] drawn on each slice) and maximum heart depth (MHD, the distance of the forefront of the heart to the line). Linear regression analysis was used to correlate these indices with mean heart dose and heart dose volume at different breathing phases. Results: Respiration-induced heart displacement resulted in observable variations in dose delivered to the heart. During a normal free-breathing cycle, heart-induced motion D{sub LAD} and MHD changed up to 9 and 11 mm respectively, resulting in up to 38% and 39% increases of mean doses and V{sub 25.2} for the heart. MHD and D{sub LAD} were positively correlated with mean heart dose and heart dose volume. Respiratory-adapted gated treatment may better spare heart and ipsilateral-lung compared with the conventional non-gated plan in a subset of patients with large D{sub LAD} or MHD variations. Conclusion: Proposed indices offer novel assessment of heart displacement based on 4DCT images. MHD and D{sub LAD} can be used independently or jointly as selection criteria for respiratory gating procedure before treatment planning. Patients with great intrafractional MHD variations or tumor(s) close to the diaphragm may particularly benefit from the gated

  19. Roles of charged particles and reactive species on cell membrane permeabilization induced by atmospheric-pressure plasma irradiation

    NASA Astrophysics Data System (ADS)

    Sasaki, Shota; Kanzaki, Makoto; Hokari, Yutaro; Tominami, Kanako; Mokudai, Takayuki; Kanetaka, Hiroyasu; Kaneko, Toshiro

    2016-07-01

    As factors that influence cell membrane permeabilization during direct and indirect atmospheric-pressure plasma irradiation, charged particle influx, superoxide anion radicals (O2 -•), and hydrogen peroxide (H2O2) in plasma-irradiated solution were evaluated. These are the three strong candidate factors and might multiply contribute to cell membrane permeabilization. In particular, a shorter plasma diffusion distance leads to the enhancement of the direct effects such as charged particle influx and further increase cell membrane permeability. In addition, O2 -• dissipates over time (a life span of the order of minutes) in plasma-irradiated water, and the deactivation of a plasma-irradiated solution in term of cell membrane permeabilization occurs in a life span of the same order. These results could promote the understanding of the mechanism of plasma-induced cell membrane permeabilization.

  20. Irradiation-induced changes of the atomic distributions around the interfaces of carbides in a nuclear reactor pressure vessel steel

    NASA Astrophysics Data System (ADS)

    Toyama, T.; Tsuchiya, N.; Nagai, Y.; Almazouzi, A.; Hatakeyama, M.; Hasegawa, M.; Ohkubo, T.; van Walle, E.; Gerard, R.

    2010-10-01

    Irradiation-induced changes of the atomic distributions of solute and impurity elements around carbides in a reactor pressure vessel steel of a Belgium nuclear power reactor were investigated by laser-assisted local electrode-type three-dimensional atom probe, before and after in-service irradiation of 12 years. Before irradiation, nano-scale Fe-Mn-Cr-Mo carbides were found to be intragranular. The atomic distributions of Mn, Cr and Mo inside the carbide indicate that their concentrations around the inner carbide-matrix interface were enhanced, while a clear segregation of P at the interface was observed. After irradiation, the Mn concentration in the carbide increased substantially. In addition, the enhancement of Mn, Cr and Mo concentrations around the interface and the segregation of P were markedly intensified.

  1. Acute and long-term alterations in the granulocyte/macrophage progenitor cell (GM-CFC) compartment of dogs after partial-body irradiation: irradiation of the upper body with a single myeloablative dose

    SciTech Connect

    Nothdurft, W.; Calvo, W.; Klinnert, V.; Steinbach, K.H.; Werner, C.; Fliedner, T.M.

    1986-06-01

    The acute and long-term effects of a single dose of partial-body irradiation on the granulocyte/macrophage progenitor cell compartment were studied in dogs. A myeloablative dose of 11.7 Gy (dose rate 6.5 cGy/min) was given to the upper body which contains approximately 70% of the total bone marrow mass. The lower part of the body was shielded by a lead box. In the non-irradiated bone marrow, the concentration of the GM-CFC/10(5) mononuclear cells was slightly decreased within the first 7 days and showed some fluctuations around the normal value for several weeks thereafter. In the irradiated bone marrow, virtually no GM-CFC could be detected on day 1 after exposure. Beginning on day 7, a continuous increase took place up to day 21 when the GM-CFC concentration reached between 25% (sternum) and 43% (humerus) of the initial value. No further increase took place up to day 80. Between day 120 and 380 a secondary increase was observed which reached near-normal bone marrow GM-CFC concentrations. The blood GM-CFC concentration first showed a strong depression followed by a transient increase between day 10 and 30. This coincided with GM-CFC normalization in the protected bone marrow as well as with the initial phase of regeneration in the irradiated sites. A prolonged secondary long-lasting depression between day 33 and 120 amounted to 20 to 50% of normal values. This depression was closely related to the stagnation in the GM-CFC recovery in the irradiated bone marrow sites. The GM-CFC concentration in the blood was supranormal at day 380 when the bone marrow GM-CFC had recovered. The colony stimulating activity in the serum showed an increase within the first 20 days after exposure. Within the same interval the bone marrow GM-CFC concentration experienced the strongest alterations, and was inversely related to the changes in the blood granulocyte values.

  2. Protective effect of alprazolam against sleep deprivation-induced behavior alterations and oxidative damage in mice.

    PubMed

    Singh, Anant; Kumar, Anil

    2008-04-01

    Sleep deprivation is considered as a risk factor for various diseases. Sleep deprivation leads to behavioral, hormonal, neurochemical and biochemical alterations in the animals. The present study was designed to explore the possible involvement of GABAergic mechanism in protective effect of alprazolam against 72h sleep deprivation-induced behavior alterations and oxidative damage in mice. In the present study, sleep deprivation caused anxiety-like behavior, weight loss, impaired ambulatory movements and oxidative damage as indicated by increase in lipid peroxidation, nitrite level and depletion of reduced glutathione and catalase activity in sleep-deprived mice brain. Treatment with alprazolam (0.25 and 0.5 mg/kg, ip) significantly improved behavioral alterations. Biochemically, alprazolam treatment significantly restored depleted reduced glutathione, catalase activity, reversed raised lipid peroxidation and nitrite level. Combination of flumazenil (0.5 mg/kg) and picrotoxin (0.5 mg/kg) with lower dose of alprazolam (0.25mg/kg) significantly antagonized protective effect of alprazolam. However, combination of muscimol (0.05 mg/kg) with alprazolam (0.25 mg/kg, ip) potentiated protective effect of alprazolam. On the basis of these results, it might be suggested that alprazolam might produce protective effect by involving GABAergic system against sleep deprivation-induced behavior alterations and related oxidative damage.

  3. Anthropogenic habitat alteration induces rapid morphological divergence in a native stream fish

    PubMed Central

    Franssen, Nathan R

    2011-01-01

    Anthropogenic habitat alteration creates novel environments that can alter selection pressures. Construction of reservoirs worldwide has disturbed riverine ecosystems by altering biotic and abiotic environments of impounded streams. Changes to fish communities in impoundments are well documented, but effects of those changes on native species persisting in reservoirs, which are presumably subjected to novel selective pressures, are largely unexplored. I assessed body shape variation of a native stream fish in reservoir habitats and streams from seven reservoir basins in the Central Plains of the USA. Body shape significantly and consistently diverged in reservoirs compared with stream habitats within reservoir basins; individuals from reservoir populations were deeper-bodied and had smaller heads compared with stream populations. Individuals from reservoir habitats also exhibited lower overall shape variation compared with stream individuals. I assessed the contribution of genotypic divergence and predator-induced phenotypic plasticity on body shape variation by rearing offspring from a reservoir and a stream population with or without a piscivorous fish. Significant population-level differences in body shape persisted in offspring, and both populations demonstrated similar predator-induced phenotypic plasticity. My results suggest that, although components of body shape are plastic, anthropogenic habitat modification may drive trait divergence in native fish populations in reservoir-altered habitats. PMID:25568023

  4. Alteration of epithelial cell lysosomal integrity induced by bacterial cholesterol‐dependent cytolysins

    PubMed Central

    Malet, Julien Karim

    2016-01-01

    Abstract Bacterial pathogens can interfere during infection with host cell organelles, such as mitochondria, the endoplasmic reticulum‐Golgi system or nuclei. As important cellular functions are often compartmentalized in these organelles, their targeting allows pathogens to manipulate key host functions during infection. Here, we identify lysosomes as a new class of organelles targeted by the pathogenic bacterium Listeria monocytogenes. We demonstrate that extracellular Listeria, via secretion of the pore‐forming toxin listeriolysin O, alters lysosomal integrity in epithelial cells but not in macrophages. Listeriolysin O induces lysosomal membrane permeabilization and release of lysosomal content, such as cathepsins proteases, which remain transiently active in the host cytosol. We furthermore show that other bacterial pore‐forming toxins, such as perfringolysin O and pneumolysin, also induce lysosomes alteration. Together, our data unveil a novel activity of bacterial cholesterol‐dependent cytolysins. PMID:27739224

  5. Target irradiation induced bystander effects between stem-like and non stem-like cancer cells.

    PubMed

    Liu, Yu; Kobayashi, Alisa; Maeda, Takeshi; Fu, Qibin; Oikawa, Masakazu; Yang, Gen; Konishi, Teruaki; Uchihori, Yukio; Hei, Tom K; Wang, Yugang

    2015-03-01

    Tumors are heterogeneous in nature and consist of multiple cell types. Among them, cancer stem-like cells (CSCs) are suggested to be the principal cause of tumor metastasis, resistance and recurrence. Therefore, understanding the behavior of CSCs in direct and indirect irradiations is crucial for clinical radiotherapy. Here, the CSCs and their counterpart non stem-like cancer cells (NSCCs) in human HT1080 fibrosarcoma cell line were sorted and labeled, then the two cell subtypes were mixed together and chosen separately to be irradiated via a proton microbeam. The radiation-induced bystander effect (RIBE) between the CSCs and NSCCs was measured by imaging 53BP1 foci, a widely used indicator for DNA double strand break (DSB). CSCs were found to be less active than NSCCs in both the generation and the response of bystander signals. Moreover, the nitric oxide (NO) scavenger c-PTIO can effectively alleviate the bystander effect in bystander NSCCs but not in bystander CSCs, indicating a difference of the two cell subtypes in NO signal response. To our knowledge, this is the first report shedding light on the RIBE between CSCs and NSCCs, which might contribute to a further understanding of the out-of-field effect in cancer radiotherapy.

  6. Radiation-induced degradation of cyclohexanebutyric acid in aqueous solutions by gamma ray irradiation

    NASA Astrophysics Data System (ADS)

    Jia, Wenbao; He, Yanquan; Ling, Yongsheng; Hei, Daqian; Shan, Qing; Zhang, Yan; Li, Jiatong

    2015-04-01

    The radiation-induced degradation of cyclohexanebutyric acid under gamma ray irradiation was investigated. Degradation experiments were performed with 100 mL sealed Pyrex glass vessels loaded with 80 mL of cyclohexanebutyric acid solutions at various initial concentrations of 10, 20, and 40 mg L-1. The absorbed doses were controlled at 0, 0.65, 1.95, 3.25, 6.5, 9.75, and 13 kGy. The results showed that gamma ray irradiation could effectively degrade cyclohexanebutyric acid in aqueous solutions. The removal rate of cyclohexanebutyric acid increased significantly with the increase of absorbed dose and the decrease of its initial concentration. At the same time, the removal of chemical oxygen demand (COD) was as effective as that of cyclohexanebutyric acid. The kinetic studies showed that the degradation of cyclohexanebutyric acid followed pseudo first-order reaction. Above all, the proposed mechanism obtained when NaNO2, NaNO3 and tert-butanol were added showed that the •OH radical played a major role in the gamma degradation process of cyclohexanebutyric acid, while •H and eaq- played a minor role in the gamma degradation process. The degradation products were identified by Fourier transform infrared spectroscopy (FTIR) and gas chromatography/mass spectrometry (GC/MS) during cyclohexanebutyric acid degradation.

  7. Interaction of irradiation-induced prismatic dislocation loops with free surfaces in tungsten

    NASA Astrophysics Data System (ADS)

    Fikar, Jan; Gröger, Roman; Schäublin, Robin

    2017-02-01

    The prismatic dislocation loops appear in metals as a result of high-energy irradiation. Understanding their formation and interaction is important for quantification of irradiation-induced deterioration of mechanical properties. Characterization of dislocation loops in thin foils is commonly made using transmission electron microscopy (TEM), but the results are inevitably influenced by the proximity of free surfaces. The prismatic loops are attracted to free surfaces by image forces. Depending on the type, size and depth of the loop in the foil, they can escape to the free surface, thus invalidating TEM observations and conclusions. In this article small prismatic hexagonal and circular dislocation loops in tungsten with the Burgers vectors 1/2 < 1 1 1 > and < 1 0 0 > are studied by molecular statics simulations using three embedded atom method (EAM) potentials. The calculated image forces are compared to known elastic solutions. A particular attention is paid to the critical stress to move edge dislocations. The escape of the loop to the free surface is quantified by a combination of atomistic simulations and elastic calculations. For example, for the 1/2 < 1 1 1 > loop with diameter 7.4 nm in a 55 nm thick foil we calculated that about one half of the loops will escape to the free surface. This implies that TEM observations detect only approx. 50% of the loops that were originally present in the foil.

  8. Silicon nanowire arrays-induced graphene oxide reduction under UV irradiation.

    PubMed

    Fellahi, Ouarda; Das, Manash R; Coffinier, Yannick; Szunerits, Sabine; Hadjersi, Toufik; Maamache, Mustapha; Boukherroub, Rabah

    2011-11-01

    This paper reports on efficient UV irradiation-induced reduction of exfoliated graphene oxide. Direct illumination of an aqueous solution of graphene oxide at λ = 312 nm for 6 h resulted in the formation of graphene nanosheets dispersible in water. X-Ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, atomic force microscopy (AFM) and electrochemical measurements (cyclic voltammetry and electrochemical impedance spectroscopy) suggest a restoration of the sp(2) carbon network. The results were compared with graphene nanosheets prepared by photochemical irradiation of a GO aqueous solution in the presence of hydrogenated silicon nanowire (SiNW) arrays or silicon nanowire arrays decorated with silver (SiNW/Ag NPs) or copper nanoparticles (SiNW/Cu NPs). Graphene nanosheets obtained by illumination of the GO aqueous solution at 312 nm for 6 h in the presence of SiNW/Cu NPs exhibited superior electrochemical charge transfer characteristics. This is mainly due to the higher amount of sp(2)-hybridized carbon in these graphene sheets found by XPS analysis. The high level of extended conjugated carbon network was also evident by the water insoluble nature of the resulting graphene nanosheets, which precipitated upon photochemical reduction.

  9. Ordered YBCO sub-micron array structures induced by pulsed femtosecond laser irradiation.

    PubMed

    Luo, C W; Lee, C C; Li, C H; Shih, H C; Chen, Y-J; Hsieh, C C; Su, C H; Tzeng, W Y; Wu, K H; Juang, J Y; Uen, T M; Chen, S P; Lin, J-Y; Kobayashi, T

    2008-12-08

    We report on the formation of organized sub-micron YBa(2)Cu(3)O(7) (YBCO) dots induced by irradiating femtosecond laser pulses on YBCO films prepared by pulse laser deposition with fluence in the range of 0.21 approximately 0.53 J/cm(2). The morphology of the YBCO film surface depends strongly on the laser fluences irradiated. At lower laser fluence (approximately 0.21 J/cm(2)) the morphology was pattern of periodic ripples with sub-micrometer spacing. Slightly increasing the laser fluence to 0.26 J/cm(2) changes the pattern into organized sub-micron dots with diameters ranging from 100 nm to 800 nm and height of 150 nm. Further increase of the laser fluence to over 0.32 J/cm(2), however, appeared to result in massive melting and led to irregular morphology. The mechanism and the implications of the current findings will be discussed. Arrays of YBCO sub-micron dots with T(c) = 89.7 K were obtained.

  10. Ionizing irradiation induces acute haematopoietic syndrome and gastrointestinal syndrome independently in mice.

    PubMed

    Leibowitz, Brian J; Wei, Liang; Zhang, Lin; Ping, Xiaochun; Epperly, Michael; Greenberger, Joel; Cheng, Tao; Yu, Jian

    2014-03-18

    The role of bone marrow (BM) and BM-derived cells in radiation-induced acute gastrointestinal (GI) syndrome is controversial. Here we use bone marrow transplantation (BMT), total body irradiation (TBI) and abdominal irradiation (ABI) models to demonstrate a very limited, if any, role of BM-derived cells in acute GI injury and recovery. Compared with WT BM recipients, mice receiving BM from radiation-resistant PUMA KO mice show no protection from crypt and villus injury or recovery after 15 or 12 Gy TBI, but have a significant survival benefit at 12 Gy TBI. PUMA KO BM significantly protects donor-derived pan-intestinal haematopoietic (CD45+) and endothelial (CD105+) cells after IR. We further show that PUMA KO BM fails to enhance animal survival or crypt regeneration in radiosensitive p21 KO-recipient mice. These findings clearly separate the effects of radiation on the intestinal epithelium from those on the BM and endothelial cells in dose-dependent acute radiation toxicity.

  11. Gamma irradiation induced in situ synthesis of lead sulfide nanoparticles in poly(vinyl alcohol) hydrogel

    NASA Astrophysics Data System (ADS)

    Kuljanin-Jakovljević, Jadranka Ž.; Radosavljević, Aleksandra N.; Spasojević, Jelena P.; Carević, Milica V.; Mitrić, Miodrag N.; Kačarević-Popović, Zorica M.

    2017-01-01

    In this study, the nanocomposites based on semiconductor lead sulfide (PbS) nanoparticles and poly(vinyl alcohol) (PVA) were investigated. The gamma irradiation induced in situ incorporation of PbS nanoparticles in crosslinked polymer network i.e. PVA hydrogel was performed. PVA hydrogel was previously obtained also under the influence of gamma irradiation. UV-Vis absorption and X-ray diffraction measurements were employed to investigate optical and structural properties of PbS nanoparticles, respectively, and obtained results indicates the presence of nanoparticles with approximately 6 nm in diameter and face centered cubic rock-salt crystal structure. The porous morphology was confirmed by scanning electron microscopy. Swelling data revealed that investigated hydrogels (PVA and PbS-PVA nanocomposite) shows non-Fickian diffusion, indicating that both diffusion and polymer relaxation processes controlled the fluid transport. The values of diffusion coefficients have an order of magnitude 10-9 cm2/s (typical values for water diffusion in polymers) and the best fit with the experimental results showed the Etters approximation. Comparing the thermal properties of PbS-PVA xerogel nanocomposite with PVA xerogel it was observed that incorporation of PbS nanoparticles in crosslinked PVA matrix just slightly enhanced the thermal stability of nanocomposite.

  12. Point defects induced in ion irradiated 4H-SiC probed by exciton lines

    NASA Astrophysics Data System (ADS)

    Litrico, G.; Zimbone, M.; Calcagno, L.; Musumeci, P.; Baratta, G. A.; Fotil, G.

    2009-05-01

    The defects produced in 4H-SiC epitaxial layers by irradiation with a 200 keV H+ ion beam in the fluence range 6.5 × 1011-1.8 × 1013 ions/cm2 are investigated by Low Temperature Photoluminescence (LTPL-40 K). The defects produced by ion beam irradiation induce the formation of some sharp lines called "alphabet lines" in the photoluminescence spectra in the 425-443 nm range, due to the recombination of excitons at structural defects. From the LTPL lines intensity trend, as function of proton fluence, it is possible to single out two groups of peaks: the P1 lines (e, f, g) and the P2 lines (a, b, c, d) that exhibit different trends with the ion fluence. The P1 group normalized yield increases with ion fluence, reaches a maximum at 2.5 × 1012 ions/cm2 and then decreases. The P2 group normalized yield, instead, exhibits a formation threshold at low fluence, then increases until a maximum value at a fluence of 3.5 × 1012 ions/cm2 and decreases at higher fluence, reaching a value of 50% of the maximum yield. The behaviour of P1 and P2 lines, with ion fluence, indicates a production of point defects at low fluence, followed by a subsequent local rearrangement creating complex defects at high fluence.

  13. Oxygen Attachment on Alkanethiolate SAMs Induced by Low-Energy Electron Irradiation

    PubMed Central

    Massey, Sylvain; Bass, Andrew D.; Steffenhagen, Marie; Sanche, Léon

    2013-01-01

    Reactions of 18O2 with self-assembled monolayer (SAM) films of 1-dodecanethiol, 1-octadecanethiol, 1-butanethiol, and benzyl mercaptan chemisorbed on gold, were studied by the electron stimulated desorption (ESD) of anionic fragments over the incident electron energy range 2–20 eV. Dosing the SAMs with 18O2 at 50 K, results in the ESD of 18O− and 18OH−. Electron irradiation of samples prior to 18O2 deposition demonstrates that intensity of subsequent 18O− and 18OH− desorption signals increase with electron fluence and that absent electron pre-irradiation, no 18O− and 18OH− ESD signals are observed, since oxygen is unable to bind to the SAMs. A minimum incident electron energy of 6–7 eV is required to initiate the binding of 18O2 to the SAMs. O2 binding is proposed to proceed by the formation of CHx−1• radicals via resonant dissociative electron attachment and non-resonant C–H dissociation processes. The weaker signals of 18O− and 18OH− from short-chain SAMs are related to the latter’s resistance to electron induced damage, due to the charge-image dipole quenching and electron delocalization. Comparison between the present results and those for DNA oligonucleotides self-assembled on Au [Mirsaleh-Kohan, N. et al. J. Chem. Phys. 2012, 136, 235104] indicates that the oxygen binding mechanism is common to both systems. PMID:23537075

  14. Ionizing irradiation induces acute haematopoietic syndrome and gastrointestinal syndrome independently in mice

    PubMed Central

    Leibowitz, Brian J.; Wei, Liang; Zhang, Lin; Ping, Xiaochun; Epperly, Michael; Greenberger, Joel; Cheng, Tao; Yu, Jian

    2015-01-01

    The role of bone marrow (BM) and BM-derived cells in radiation-induced acute gastrointestinal (GI) syndrome is controversial. Here we use bone marrow transplantation (BMT), total body irradiation (TBI) and abdominal irradiation (ABI) models to demonstrate a very limited, if any, role of BM-derived cells in acute GI injury and recovery. Compared with WT BM recipients, mice receiving BM from radiation-resistant PUMA KO mice show no protection from crypt and villus injury or recovery after 15 or 12 Gy TBI, but have a significant survival benefit at 12 Gy TBI. PUMA KO BM significantly protects donor-derived pan-intestinal haematopoietic (CD45 +) and endothelial (CD105 +) cells after IR. We further show that PUMA KO BM fails to enhance animal survival or crypt regeneration in radiosensitive p21 KO-recipient mice. These findings clearly separate the effects of radiation on the intestinal epithelium from those on the BM and endothelial cells in dose-dependent acute radiation toxicity. PMID:24637717

  15. Analysis of Obstacle Hardening Models Using Dislocation Dynamics: Application to Irradiation-Induced Defects

    NASA Astrophysics Data System (ADS)

    Sobie, Cameron; Bertin, Nicolas; Capolungo, Laurent

    2015-08-01

    Irradiation hardening in -iron represents a critical factor in nuclear reactor design and lifetime prediction. The dispersed barrier hardening, Friedel Kroupa Hirsch (FKH), and Bacon Kocks Scattergood (BKS) models have been proposed to predict hardening caused by dislocation obstacles in metals, but the limits of their applicability have never been investigated for varying defect types, sizes, and densities. In this work, dislocation dynamics calculations of irradiation-induced obstacle hardening in the athermal case were compared to these models for voids, self-interstitial atom (SIA) loops, and a combination of the two types. The BKS model was found to accurately predict hardening due to voids, whereas the FKH model was superior for SIA loops. For both loops and voids, the hardening from a normal distribution of defects was compared to that from the mean size, and was shown to have no statistically significant dependence on the distribution. A mean size approach was also shown to be valid for an asymmetric distribution of voids. A non-linear superposition principle was shown to predict the hardening from the simultaneous presence of voids and SIA loops.

  16. Displacement damage effects on CMOS APS image sensors induced by neutron irradiation from a nuclear reactor

    SciTech Connect

    Wang, Zujun Huang, Shaoyan; Liu, Minbo; Xiao, Zhigang; He, Baoping; Yao, Zhibin; Sheng, Jiangkun

    2014-07-15

    The experiments of displacement damage effects on CMOS APS image sensors induced by neutron irradiation from a nuclear reactor are presented. The CMOS APS image sensors are manufactured in the standard 0.35 μm CMOS technology. The flux of neutron beams was about 1.33 × 10{sup 8} n/cm{sup 2}s. The three samples were exposed by 1 MeV neutron equivalent-fluence of 1 × 10{sup 11}, 5 × 10{sup 11}, and 1 × 10{sup 12} n/cm{sup 2}, respectively. The mean dark signal (K{sub D}), dark signal spike, dark signal non-uniformity (DSNU), noise (V{sub N}), saturation output signal voltage (V{sub S}), and dynamic range (DR) versus neutron fluence are investigated. The degradation mechanisms of CMOS APS image sensors are analyzed. The mean dark signal increase due to neutron displacement damage appears to be proportional to displacement damage dose. The dark images from CMOS APS image sensors irradiated by neutrons are presented to investigate the generation of dark signal spike.

  17. Microwave radiation (2450 MHz) alters the endotoxin-induced hypothermic response of rats

    SciTech Connect

    Smialowicz, R.J.; Compton, K.L.; Riddle, M.M.; Rogers, R.R.; Brugnolotti, P.L.

    1980-01-01

    The parenteral administration of bacterial endotoxin to rats causes a hypothermia that is maximal after approximately 90 minutes. When endotoxin-injected rats were held in a controlled environment at 22 degree C and 50% relative humidity and exposed for 90 minutes to microwaves (2450 MHz, CW) at 1 mW/cm2, significant increases were observed in body temperature compared with endotoxin-treated, sham-irradiated rats. The magnitude of the response was related to power density (10 mW/cm2 greater than 5 mW/cm2 greater than 1 mW/cm2). Saline-injected rats exposed for 90 minutes at 5 mW/cm2 (specific absorption rate approximately 1.0 mW/g) showed no significant increase in body temperature compared with saline-injected, sham-irradiated rats. The hypothermia induced by endotoxin in rats was also found to be affected by ambient temperature alone. Increases in ambient temperature above 22 degree C in the absence of microwaves caused a concomitant increase in body temperature. This study reveals that subtle microwave heating is detectable in endotoxin-treated rats that have impaired thermoregulatory capability. These results indicate that the interpretation of microwave-induced biological effects observed in animals at comparable rates and levels of energy absorption should include a consideration of the thermogenic potential of microwave.

  18. Chronic ultraviolet exposure-induced p53 gene alterations in sencar mouse skin carcinogenesis model

    SciTech Connect

    Tong, Ying; Smith, M.A.; Tucker, S.B.

    1997-06-27

    Alterations of the tumor suppressor gene p53 have been found in ultraviolet radiation (UVR) related human skin cancers and in UVR-induced murine skin tumors. However, links between p53 gene alterations and the stages of carcinogenesis induced by UVR have not been clearly defined. We established a chronic UVR exposure-induced Sencar mouse skin carcinogenesis model to determine the frequency of p53 gene alterations in different stages of carcinogenesis, including UV-exposed skin, papillomas, squamous-cell carcinomas (SCCs), and malignant spindle-cell tumors (SCTs). A high incidence of SCCs and SCTs were found in this model. Positive p53 nuclear staining was found in 10137 (27%) of SCCs and 12124 (50%) of SCTs, but was not detected in normal skin or papillomas. DNA was isolated from 40 paraffin-embedded normal skin, UV-exposed skin, and tumor sections. The p53 gene (exons 5 and 6) was amplified from the sections by using nested polymerase chain reaction (PCR). Subsequent single-strand conformation polymorphism (SSCP) assay and sequencing analysis revealed one point mutation in exon 6 (coden 193, C {r_arrow} A transition) from a UV-exposed skin sample, and seven point mutations in exon 5 (codens 146, 158, 150, 165, and 161, three C {r_arrow} T, two C {r_arrow} A, one C {r_arrow} G, and one A {r_arrow} T transition, respectively) from four SCTs, two SCCs and one UV-exposed skin sample. These experimental results demonstrate that alterations in the p53 gene are frequent events in chronic UV exposure-induced SCCs and later stage SCTs in Sencar mouse skin. 40 refs., 5 figs., 1 tab.

  19. Exercise-induced hemostatic alterations are detectable by rotation thrombelastography (ROTEM): A marathon study.

    PubMed

    Sucker, Christoph; Zotz, Rainer B; Senft, Beate; Scharf, Rudiger E; Kröger, Knut; Erbel, Raimund; Möhlenkamp, Stefan

    2010-10-01

    Rotation thrombelastography (ROTEM) provides a whole blood assay that allows the assessment of plasmic- and platelet-related hemostasis in a single-step procedure. In our current study, we focused on the capability of the method to detect hemostatic alterations induced by physical exercise, enrolling 33 healthy participants of the Dusseldorf Marathon 2006. Venous blood drawn immediately before and after finishing the marathon was analyzed by a rotational thrombelastograph (Pentapharm, Munich, Germany). On initiation of blood coagulation by recalcification, standard ROTEM parameters were determined. Comparison of the results obtained before and after the physical exercise was performed using the Student t test for paired samples. As a result, the mean clotting time (CT) determined from blood samples obtained immediately after the marathon was significantly shorter (662.9 + or - 67.8 seconds vs 505.6 + or - 97.3 seconds, P = .002) and the mean maximal clot firmness was significantly broader (48.4 +/- 6.6 mm vs 51.5 +/- 4.5 mm, P = .0004) when compared to results obtained before the physical exercise. Differences between mean clot formation times (CFTs; 280.6 + 96 seconds vs 270.4 + or - 73.8 seconds) and mean alpha angles (45.9 degrees + or - 8 degrees vs 47.8 degrees + or - 5.8 degrees ) before and after the marathon were not statistically significant. Remarkably, some participants showed opposed results, particularly prolongation of CT and narrowing of maximum clot firmness (MCF). Our study demonstrates that ROTEM is sensitive to exercise-induced hemostatic alterations. The method appears to be capable of detecting even distinct changes in hemostasis in a single-step procedure. Further analyses are needed to clarify which hemostasis parameters influence ROTEM results and which ROTEM results are independent predictors of exercise-induced alterations of plasmic and platelet function. This might help to explain interindividual differences in exercise-induced

  20. Altered Gastric Emptying and Prevention of Radiation-Induced Vomiting in Dogs

    DTIC Science & Technology

    1984-03-01

    nausea and vomiting is common10ily oh- of 10 dog$ pt’etrtolted wvith domperidone (p) < 0.01). served. These symptoms can occur after total body Gastric...Gastroenterol of radiotherapy-induced nausea and vomiting . Postgrad Med 1981;16(Suppl 67):33-6. 1979;55(Suppl 1):50-4. V.a, ...00_© 000 ’-- Altered gastric emptying and prevention of radiation-induced vomiting in dogs A. Dubois cc I J. P. Jacobus M. P. Grissom R.R. Eng J. J

  1. Effects of heavy particle irradiation and diet on amphetamine- and lithium chloride-induced taste avoidance learning in rats

    NASA Technical Reports Server (NTRS)

    Rabin, Bernard M.; Shukitt-Hale, Barbara; Szprengiel, Aleksandra; Joseph, James A.

    2002-01-01

    Rats were maintained on diets containing either 2% blueberry or strawberry extract or a control diet for 8 weeks prior to being exposed to 1.5 Gy of 56Fe particles in the Alternating Gradient Synchrotron at Brookhaven National Laboratory. Three days following irradiation, the rats were tested for the effects of irradiation on the acquisition of an amphetamine- or lithium chloride-induced (LiCl) conditioned taste avoidance (CTA). The rats maintained on the control diet failed to show the acquisition of a CTA following injection of amphetamine. In contrast, the rats maintained on antioxidant diets (strawberry or blueberry extract) continued to show the development of an amphetamine-induced CTA following exposure to 56Fe particles. Neither irradiation nor diet had an effect on the acquisition of a LiCl-induced CTA. The results are interpreted as indicating that oxidative stress following exposure to 56Fe particles may be responsible for the disruption of the dopamine-mediated amphetamine-induced CTA in rats fed control diets; and that a reduction in oxidative stress produced by the antioxidant diets functions to reinstate the dopamine-mediated CTA. The failure of either irradiation or diet to influence LiCl-induced responding suggests that oxidative stress may not be involved in CTA learning following injection of LiCl.

  2. Ozone-induced injury and oxidative stress in bronchiolar epithelium are associated with altered pulmonary mechanics.

    PubMed

    Sunil, Vasanthi R; Vayas, Kinal N; Massa, Christopher B; Gow, Andrew J; Laskin, Jeffrey D; Laskin, Debra L

    2013-06-01

    In these studies, we analyzed the effects of ozone on bronchiolar epithelium. Exposure of rats to ozone (2 ppm, 3 h) resulted in rapid (within 3 h) and persistent (up to 72 h) histological changes in the bronchiolar epithelium, including hypercellularity, loss of cilia, and necrotizing bronchiolitis. Perivascular edema and vascular congestion were also evident, along with a decrease in Clara cell secretory protein in bronchoalveolar lavage, which was maximal 24 h post-exposure. Ozone also induced the appearance of 8-hydroxy-2'-deoxyguanosine, Ym1, and heme oxygenase-1 in the bronchiolar epithelium. This was associated with increased expression of cleaved caspase-9 and beclin-1, indicating initiation of apoptosis and autophagy. A rapid and persistent increase in galectin-3, a regulator of epithelial cell apoptosis, was also observed. Following ozone exposure (3-24 h), increased expression of cyclooxygenase-2, inducible nitric oxide synthase, and arginase-1 was noted in bronchiolar epithelium. Ozone-induced injury and oxidative stress in bronchiolar epithelium were linked to methacholine-induced alterations in pulmonary mechanics. Thus, significant increases in lung resistance and elastance, along with decreases in lung compliance and end tidal volume, were observed at higher doses of methacholine. This indicates that ozone causes an increase in effective stiffness of the lung as a consequence of changes in the conducting airways. Collectively, these studies demonstrate that bronchiolar epithelium is highly susceptible to injury and oxidative stress induced by acute exposure to ozone; moreover, this is accompanied by altered lung functioning.

  3. Mannosylated lipoarabinomannan antagonizes Mycobacterium tuberculosis-induced macrophage apoptosis by altering Ca+2-dependent cell signaling.

    PubMed

    Rojas, M; García, L F; Nigou, J; Puzo, G; Olivier, M

    2000-07-01

    Mycobacterium tuberculosis-induced macrophage apoptosis can be inhibited by mannosylated lipoarabinomannan (ManLAM), although it induces tumor necrosis factor (TNF)-alpha and NO production, which participate in apoptosis induction. ManLAM also modulates Ca(+2)-dependent intracellular events, and Ca(+2) participates in apoptosis in different systems. Ca(+2) was assessed for involvement in M. tuberculosis-induced macrophage apoptosis and for modulation by ManLAM. The role of Ca(+2) was supported by the blockade of apoptosis by cAMP inhibitors and the Ca(+2) chelator, BAPTA/AM. These agents also inhibited caspase-1 activation and cAMP-responsive element-binding protein translocation without affecting TNF-alpha production. Infection of macrophages with M. tuberculosis induced an influx of Ca(+2) that was prevented by ManLAM. Similarly, M. tuberculosis infection-altered mitochondrial permeability transition was prevented by ManLAM and BAPTA/AM. Finally, ManLAM and BAPTA/AM reversed the effects of M. tuberculosis on p53 and Bcl-2 expression. ManLAM counteracts the alterations of calcium-dependent intracellular events that occur during M. tuberculosis-induced macrophage apoptosis.

  4. Tumor-induced lymph node alterations detected by MRI lymphography using gadolinium nanoparticles.

    PubMed

    Partridge, S C; Kurland, B F; Liu, C-L; Ho, R J Y; Ruddell, A

    2015-10-26

    Contrast-enhanced MRI lymphography shows potential to identify alterations in lymph drainage through lymph nodes (LNs) in cancer and other diseases. MRI studies have typically used low molecular weight gadolinium contrast agents, however larger gadolinium-loaded nanoparticles possess characteristics that could improve the specificity and sensitivity of lymphography. The performance of three gadolinium contrast agents with different sizes and properties was compared by 3T MRI after subcutaneous injection. Mice bearing B16-F10 melanoma footpad tumors were imaged to assess tumor-induced alterations in lymph drainage through tumor-draining popliteal and inguinal LNs versus contralateral uninvolved drainage. Gadolinium lipid nanoparticles were able to identify tumor-induced alterations in contrast agent drainage into the popliteal LN, while lower molecular weight or albumin-binding gadolinium agents were less effective. All of the contrast agents distributed in foci around the cortex and medulla of tumor-draining popliteal LNs, while they were restricted to the cortex of non-draining LNs. Surprisingly, second-tier tumor-draining inguinal LNs exhibited reduced uptake, indicating that tumors can also divert LN drainage. These characteristics of tumor-induced lymph drainage could be useful for diagnosis of LN pathology in cancer and other diseases. The preferential uptake of nanoparticle contrasts into tumor-draining LNs could also allow selective targeting of therapies to tumor-draining LNs.

  5. Fractal parameterization analysis of ferroelectric domain structure evolution induced by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Maslovskaya, A. G.; Barabash, T. K.

    2017-01-01

    The article presents some results of fractal analysis of ferroelectric domain structure images visualized with scanning electron microscope (SEM) techniques. The fractal and multifractal characteristics were estimated to demonstrate self-similar organization of ferroelectric domain structure registered with static and dynamic contrast modes of SEM. Fractal methods as sensitive analytical tools were used to indicate degree of domain structure and domain boundary imperfections. The electron irradiation-induced erosion effect of ferroelectric domain boundaries in electron beam-stimulated polarization current mode of SEM is characterized by considerable raising of fractal dimension. For dynamic contrast mode of SEM there was revealed that complication of domain structure during its dynamics is specified by increase in fractal dimension of images and slight raising of boundary fractal dimension.

  6. {gamma} Irradiation-induced degradation of organochlorinated pollutants in fatty esters and in Cod

    SciTech Connect

    Lepine, F.L.; Brochu, F.; Milot, S.

    1995-02-01

    The {gamma} irradiation-induced degradation of 2,2-bis(4-chlorophenyl)-1,1,1-trichloroethane (DDT), 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (DDD), and 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) dissolved in methyl myristate and methyl oleate was studied. DDT and DDE produced DDD and 2,2-bis(4-chlorophenyl)chloroethylene (DDMU) respectively, in agreement with a previous study performed with aliphatic solvents. The degradation of these two former compounds was larger in methyl myristate than in methyl oleate and addition products between methyl myristate and the organochlorines were found. While DDD, DDE, and many PCB congeners in a cod sample were not measurably degraded at 15 KGy, DDT underwent 30% degradation. 9 refs., 1 fig., 2 tabs.

  7. Magnetic properties on the surface of FeAl stripes induced by nanosecond pulsed laser irradiation

    NASA Astrophysics Data System (ADS)

    Kaiju, H.; Yoshida, Y.; Watanabe, S.; Kondo, K.; Ishibashi, A.; Yoshimi, K.

    2014-05-01

    We demonstrate the formation of magnetic nanostripes on the surface of Fe52Al48 induced by nanosecond pulsed laser irradiation and investigate their magnetic properties. The magnetic stripe consists of a disordered A2 phase of Fe-Al alloys with Al-oxide along the [110] direction on the (111)-oriented plane. According to the focused magneto-optical Kerr effect measurement, the coercive force of the magnetic stripe obeys the 1/cos θ law, where θ is the field rotation angle estimated from the stripe direction. Also, the jump field can be observed in the magnetic hysteresis loop. These results indicate that the magnetization reversal in the magnetic stripe originates from the domain pinning, showing that the magnetization rotates incoherently.

  8. Thermally stimulated current studies on neutron irradiation induced defects in GaN

    NASA Astrophysics Data System (ADS)

    Kuriyama, K.; Ooi, M.; Onoue, A.; Kushida, K.; Okada, M.; Xu, Q.

    2006-03-01

    The evaluation of the neutron irradiation induced defects in GaN is studied using a thermally stimulated current (TSC) method with excitation above (below) the energy band gap using ultraviolet (blue, green, red, and infrared) emitting diodes. Annealing at 1000°C, a broad TSC spectrum for excitation by the ultraviolet light is resolved by five traps, P1 (ionization energy is 200meV), P2 (270meV), P3 (380meV), P4 (490meV), and P5 (595meV). Infrared illumination shows a remarkable reduction in TSC for the P2 and P3 traps, indicating the photoquenching behavior. The possible origins of the observed five traps are discussed.

  9. Radiation-induced effects in the electron-beam irradiation of dietary flavonoids

    NASA Astrophysics Data System (ADS)

    Tamba, M.; Torreggiani, A.

    2004-09-01

    The harmful effects of oxidative processes in living organisms can be reduced by the dietary intake of flavonoids, a class of phenolic compounds ubiquitous in plants and widely found in a number of fruits, vegetables and beverages. Many fruits and vegetables are treated by irradiation to solve preservation problems and a radical-induced degradation of nutrients, including polyphenols, may occur. The free radical chemistry of two abundant flavonoids in food, catechin and quercetin, have been investigated by using pulse radiolysis technique. The central role of the phenoxyl-type radical and the strong influence of the state of protonation of the compounds on the pathway of formation and decay of the corresponding oxidized radicals has been evidenced from the spectral properties and chemical reactivity of the radicals derived from the attack of several oxidizing species ( ṡOH, N 3ṡ SO 4-ṡ).

  10. Orientation relationship formed during irradiation induced precipitation of W in Cu

    NASA Astrophysics Data System (ADS)

    Tai, Kaiping; Averback, Robert S.; Bellon, Pascal; Vo, Nhon; Ashkenazy, Yinon; Dillon, Shen J.

    2014-11-01

    Irradiation of dilute Cu-W alloys with 1.8 MeV Kr+ between 300 K and 573 K is found to induce nucleation of a high density of W nano-precipitates. HRTEM and aberration-corrected STEM reveal that the ∼3 nm precipitates have a preferred orientation relationship with the matrix. A variant of the Bain relationship exists with preferred alignment occurring along Cu<2 2 0> || W<010>, with small angular differences amongst the particles, which is compensated by interfacial dislocations or strain. The formation mechanism for such an orientation relationship is rationalized on the basis that small W clusters form within the local melt of an energetic displacements cascade, resulting in the partial alignment of the nanoprecipitates with the Cu lattice as the Cu solidifies.

  11. Study of nanostructure growth with nanoscale apex induced by femtosecond laser irradiation at megahertz repetition rate

    PubMed Central

    2013-01-01

    Leaf-like nanostructures with nanoscale apex are induced on dielectric target surfaces by high-repetition-rate femtosecond laser irradiation in ambient conditions. We have recently developed this unique technique to grow leaf-like nanostructures with such interesting geometry without the use of any catalyst. It was found to be possible only in the presence of background nitrogen gas flow. In this synthesis method, the target serves as the source for building material as well as the substrate upon which these nanostructures can grow. In our investigation, it was found that there are three possible kinds of nanotips that can grow on target surfaces. In this report, we have presented the study of the growth mechanisms of such leaf-like nanostructures under various conditions such as different laser pulse widths, pulse repetition rates, dwell times, and laser polarizations. We observed a clear transformation in the kind of nanotips that grew for the given laser conditions. PMID:23607832

  12. Swift heavy ion irradiation induced phase transformation in calcite single crystals

    NASA Astrophysics Data System (ADS)

    Nagabhushana, H.; Nagabhushana, B. M.; Lakshminarasappa, B. N.; Singh, Fouran; Chakradhar, R. P. S.

    2009-11-01

    Ion irradiation induced phase transformation in calcite single crystals have been studied by means of Raman and infrared spectroscopy using 120 MeV Au 9+ ions. The observed bands have been assigned according to group theory analysis. For higher fluence of 5×10 12 ion/cm 2, an extra peak on either side of the 713 cm -1 peak and an increase in the intensity of 1085 cm -1 peak were observed in Raman studies. FTIR spectra exhibit extra absorption bands at 674, 1589 cm -1 and enhancement in bands at 2340 and 2374 cm -1 was observed. This might be due to the phase transformation from calcite to vaterite. The damage cross section ( σ) for all the Raman and FTIR active modes was determined. The increase of FWHM, shift in peak positions and appearance of new peaks indicated that calcite phase is converted into vaterite.

  13. Alteration of resonance structure of water and bioliquids in microwave band under the influence of He-Ne laser irradiation

    NASA Astrophysics Data System (ADS)

    Brill, Gregory E.; Petrosyan, Voldemar I.; Zhytenyova, Elina A.; Sinitsyn, Nickolay I.; Kiritchuk, Vyacheslav F.; Martinov, Lev A.

    2001-07-01

    By means of the new method of transmission-resonance EHF/SHF radiowave spectroscopy alteration of the resonance structure of water, whole blood, blood plasma, serum and erythrocytes haemolysate under the influence of He-Ne laser radiation was established.

  14. Effects of prenatal irradiation with an accelerated heavy-ion beam on postnatal development in rats: II. Further study on neurophysiologic alterations

    NASA Astrophysics Data System (ADS)

    Wang, B.; Murakami, M.; Eguchi-Kasai, K.; Nojima, K.; Shang, Y.; Tanaka, K.; Watanabe, K.; Fujita, K.; Moreno, S. G.; Coffigny, H.; Hayata, I.

    Organogenesis is a highly radiosensitive period, study of prenatal exposure to high LET heavy ion beams on postnatal development is important for clarifying the radiation risk in space and promoting the evidence-based mechanism research. The effects from heavy ion irradiations are not well studied as those for low LET radiations such as X-rays in this field, even the ground-based investigations remain to be addressed. Using the Heavy Ion Medical Accelerator in Chiba (HIMAC) and Wistar rats, postnatal neurophysiological development in offspring was investigated following exposure of pregnant rats to accelerated neon-ion beams with a LET value of about 30 keV/μm at a dose range from 0.1 to 2.0 Gy on the 15th day of gestation. The age for appearance of four physiologic markers and attainment of five neonatal reflexes, and gain in body weight were monitored. Male offspring were evaluated as young adults using two behavioral tests including open field and hole-board dipping tests. The effects of X-rays at 200 kVp measured for the same biological end points were studied for comparison. For most of the endpoints at early age, significant neurophysiological alteration was observed even in offspring receiving 0.1 Gy of accelerated neon ions but not X-rays. All offspring receiving 2.0 Gy of accelerated neon ions died prior to weaning. Offspring prenatally irradiated with neon ions generally showed higher incidences of prenatal death, increased preweaning mortality, markedly delayed accomplishment in physiological markers and reflexes, significantly lower body weight and reduced ratios of main organ weight to body weight, and altered behavior compared to those exposed to X-rays at doses of 0.1 1.5 Gy. These findings indicate that irradiations with neon ions at 0.1 1.5 Gy on day 15 of gestation caused varied developmental alterations in offspring, and efficient dose leading to the detrimental effects seemed to be lower than that of X-rays.

  15. Bog blueberry anthocyanins alleviate photoaging in ultraviolet-B irradiation-induced human dermal fibroblasts.

    PubMed

    Bae, Ji-Young; Lim, Soon Sung; Kim, Sun Ju; Choi, Jung-Suk; Park, Jinseu; Ju, Sung Mi; Han, Seoung Jun; Kang, Il-Jun; Kang, Young-Hee

    2009-06-01

    Fruits of bog blueberry (Vaccinium uliginosum L.) are rich in anthocyanins that contribute pigmentation. Anthocyanins have received much attention as agents with potentials preventing chronic diseases. This study investigated the capacity of anthocyanin-rich extract from bog blueberry (ATH-BBe) to inhibit photoaging in UV-B-irradiated human dermal fibroblasts. BBe anthocyanins were detected as cyanidin-3-glucoside, petunidin-3-glucoside, malvidin-3-glucoside, and delphinidin3-glucoside. ATH-BBe attenuated UV-B-induced toxicity accompanying reactive oxygen species (ROS) production and the resultant DNA damage responsible for activation of p53 and Bad. Preincubation of ATH-BBe markedly suppressed collagen degradation via blunting production of collagenolytic matrix metalloproteinases (MMP). Additionally, ATH-BBe enhanced UV-B-downregulated procollagen expression at transcriptional levels. We next attempted to explore whether ATH-BBe mitigated the MMP-promoted collagen degradation through blocking nuclear factor kappaB (NF-kappaB) activation and MAPK-signaling cascades. UV-B radiation enhanced nuclear translocation of NF-kappaB, which was reversed by treatment with ATH-BBe. The UV-B irradiation rapidly activated apoptosis signal-regulating kinase-1 (ASK-1)-signaling cascades of JNK and p38 mitogen-activated protein kinase (p38 MAPK), whereas ATH-BBe hampered phosphorylation of c-Jun, p53, and signal transducers and activators of transcription-1 (STAT-1) linked to these MAPK signaling pathways. ATH-BBe diminished UV-B augmented-release of inflammatory interleukin (IL)-6 and IL-8. These results demonstrate that ATH-BBe dampens UV-B-triggered collagen destruction and inflammatory responses through modulating NF-kappaB-responsive and MAPK-dependent pathways. Therefore, anthocyanins from edible bog blueberry may be protective against UV-induced skin photoaging.

  16. Observation and analysis on skin cancer induced by UVB irradiation using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Wang, Yunxia; Wu, Shulian; Li, Hui; Zheng, Xiaoxiao

    2014-09-01

    Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the prevalent skin cancers, which have a quite high incidence in the white race. In recent years, however, their incidences have been increasing in the yellow race, resulting in a great threat to the public health. According to researches, chronics UVB irradiation (280nm~320nm) is the major culprit of skin cancer in humans. In our study, the model of UVB induced skin cancer was established firstly. Optical coherence tomography (OCT) combined with the histopathology was exploited to monitor the morphologic and histological changes of the process of UVB induced skin cancer. Meanwhile, this canceration process was systematically studied and analyzed from the perspective of tissue optics. The attenuation coefficient (μt) has a rising trend in the epidermis, but which shows a downward trend in the dermis. The results are conducive to understand the process of UVB-induced skin cancer and further be able to provide a reference for medical researchers.

  17. Low-power laser irradiation inhibits Aβ25-35-induced cell apoptosis through Akt activation

    NASA Astrophysics Data System (ADS)

    Zhang, Zhigang; Tang, Yonghong

    2009-08-01

    Low-power laser irradiation (LPLI) can modulate various cellular processes such as proliferation, differentiation and apoptosis. Recently, LPLI has been applied to moderate Alzheimer's disease (AD), but the underlying mechanism remains unknown. The protective role of LPLI against the amyloid beta peptide (Aβ), a major constituent of AD plaques, has not been studied. PI3K/Akt pathway is extremely important in protecting cells from apoptosis caused by diverse stress stimuli. However, whether LPLI can inhibit Aβ-induced apoptosis through Akt activation is still unclear. In current study, using FRET (fluorescence resonance energy transfer) technique, we investigated the activity of Akt in response to LPLI treatment. B kinase activity reporter (BKAR), a recombinant FRET probe of Akt, was utilized to dynamically detect the activation of Akt after LPLI treatment. The results show that LPLI promoted the activation of Akt. Moreover, LPLI inhibits apoptosis induced by Aβ25-35 and the apoptosis inhibition can be abolished by wortmannin, a specific inhibitor of PI3K/Akt. Taken together, these results suggest that LPLI can inhibit Aβ25-35-induced cell apoptosis through Akt activation.

  18. Effects of carotenoids on damage of biological lipids induced by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Saito, Takeshi; Fujii, Noriko

    2014-05-01

    Carotenoids are considered to be involved in the radioresistant mechanisms of radioresistant bacteria. In these bacterial cells, carotenoids are present in biological lipids, and therefore may be related to the radiation-induced damage of lipids. However, only limited data are available for the role of carotenoids in such damage. In this study, we irradiated an α-linolenic acid-benzene solution with gamma rays and analyzed the resulting oxidative degradation and peroxidation damage in the presence or absence of two typical carotenoids: β-carotene and astaxanthin. The analyses revealed that oxidative degradation and peroxidation of α-linolenic acid, as evaluated by the amount of malondialdehyde and conjugated diene formed, respectively, increased in a dose-dependent manner. Moreover, 8.5×10-3 M β-carotene inhibited gamma radiation-induced oxidative degradation of α-linolenic acid, whereas 5.0×10-5 and 5.0×10-6 M β-carotene, and 5.0×10-7 and 5.0×10-8 M astaxanthin promoted degradation. In contrast, neither β-carotene nor astaxanthin affected peroxidation of α-linolenic acid. These results suggest that an optimum concentration of carotenoids in radioresistant bacteria protects biological lipid structures from radiation-induced damage.

  19. The effects of low-intensity laser irradiation on the fatigue induced by dysfunction of mitochondria

    NASA Astrophysics Data System (ADS)

    Xu, Xiao-Yang; Liu, Timon C.; Duan, Rui; Liu, Xiao-Guang

    2003-12-01

    Exercise-induced fatigue has long been an important field in sports medicine. The electron leak of mitochondrial respiratory chain during the ATP synthesis integrated with proton leak and O-.2 can decrease the efficiency of ATP synthesis in mitochondria. And the exercise-induced fatigue occur followed by the decrease of performance. If the dysfunction of mitochondria can be avoided, the fatigue during the exercise may be delayed and the performance may be enhanced. Indeed there are some kind of materials can partially prevent the decrease of ATP synthesis efficiency in mitochondria. But the side effects and safety of these materials is still needed to be studied. Low intensity laser can improve the mitochondria function. It is reasonable to consider that low intensity laser therapy may become the new and more effective way to delay or elimination the fatigue induced by dysfunction of mitochondria. Because the effect of laser irradiation may not be controlled exactly when study in vivo, we use electrical stimulation of C2C12 muscle cells in culture to define the effect of low intensity laser on the dysfunction of mitochondria, and to define the optimal laser intensity to prevent the decrease of ATP synthesis efficiency. Our study use the C2C12 muscle cells in culture to define some of the mechanisms involved in the contractile-induced changes of mitochondrial function firstly in sports medicine and may suggest a useful study way to other researchers. We also give a new way to delay or eliminating the fatigue induced by dysfunction of mitochondria without side effect.

  20. Ionizing irradiation induces apoptotic damage of salivary gland acinar cells via NADPH oxidase 1-dependent superoxide generation

    SciTech Connect

    Tateishi, Yoshihisa Sasabe, Eri; Ueta, Eisaku; Yamamoto, Tetsuya

    2008-02-08

    Reactive oxygen species (ROS) have important roles in various physiological processes. Recently, several novel homologues of the phagocytic NADPH oxidase have been discovered and this protein family is now designated as the Nox family. We investigated the involvement of Nox family proteins in ionizing irradiation-induced ROS generation and impairment in immortalized salivary gland acinar cells (NS-SV-AC), which are radiosensitive, and immortalized ductal cells (NS-SV-DC), which are radioresistant. Nox1-mRNA was upregulated by {gamma}-ray irradiation in NS-SV-AC, and the ROS level in NS-SV-AC was increased to approximately threefold of the control level after 10 Gy irradiation. The increase of ROS level in NS-SV-AC was suppressed by Nox1-siRNA-transfection. In parallel with the suppression of ROS generation and Nox1-mRNA expression by Nox1-siRNA, ionizing irradiation-induced apoptosis was strongly decreased in Nox1-siRNA-transfected NS-SV-AC. There were no large differences in total SOD or catalase activities between NS-SV-AC and NS-SV-DC although the post-irradiation ROS level in NS-SV-AC was higher than that in NS-SV-DC. In conclusion, these results indicate that Nox1 plays a crucial role in irradiation-induced ROS generation and ROS-associated impairment of salivary gland cells and that Nox1 gene may be targeted for preservation of the salivary gland function from radiation-induced impairment.

  1. Ultraviolet light-emitting diode irradiation-induced cell death in HL-60 human leukemia cells in vitro

    PubMed Central

    XIE, DONG; SUN, YAN; WANG, LINGZHEN; LI, XIAOLING; ZANG, CHUANNONG; ZHI, YUNLAI; SUN, LIRONG

    2016-01-01

    Ultraviolet (UV) radiation is considered to be a potent cell-damaging agent in various cell lineages; however, the effect of UV light-emitting diode (LED) irradiation on human cells remains unclear. The aim of the present study was to examine the effect of UV LED irradiation emitting at 280 nm on cultured HL-60 human leukemia cells, and to explore the underlying mechanisms. HL-60 cells were irradiated with UV LED (8, 15, 30 and 60 J/m2) and incubated for 2 h after irradiation. The rates of cell proliferation and apoptosis, the cell cycle profiles and the mRNA expression of B-cell lymphoma 2 (Bcl-2) were detected using cell counting kit-8, multicaspase assays, propidium iodide staining and reverse transcription-quantitative polymerase chain reaction, respectively. The results showed that UV LED irradiation (8–60 J/m2) inhibited the proliferation of HL-60 cells in a dose-dependent manner. UV LED at 8–30 J/m2 induced dose-dependent apoptosis and G0/G1 cell cycle arrest, and inhibited the expression of Bcl-2 mRNA, while UV LED at 60 J/m2 induced necrosis. In conclusion, 280 nm UV LED irradiation inhibits proliferation and induces apoptosis and necrosis in cultured HL-60 cells. In addition, the cell cycle arrest at the G0/G1 phase and the downregulation of Bcl-2 mRNA expression were shown to be involved in UV LED-induced apoptosis. PMID:26820261

  2. Protective effects of sodium selenite supplementation against irradiation-induced damage in non-cancerous human esophageal cells.

    PubMed

    Puspitasari, Irma M; Yamazaki, Chiho; Abdulah, Rizky; Putri, Mirasari; Kameo, Satomi; Nakano, Takashi; Koyama, Hiroshi

    2017-01-01

    The administration of radioprotective compounds is one approach to preventing radiation damage in non-cancerous tissues. Therefore, radioprotective compounds are crucial in clinical radiotherapy. Selenium is a radioprotective compound that has been used in previous clinical studies of radiotherapy. However, evidence regarding the effectiveness of selenium in radiotherapy and the mechanisms underlying the selenium-induced reduction of the side effects of radiotherapy remains insufficient. To further investigate the effectiveness of selenium in radiotherapy, the present study examined the protective effects of sodium selenite supplementation administered prior to X-ray radiation treatment in CHEK-1 non-cancerous human esophageal cells. Sodium selenite supplementation increased glutathione peroxidase 1 (GPx-1) activity in a dose- and time-dependent manner. The sodium selenite dose that induced the highest GPx-1 activity was determined to be 50 nM for 72 h prior to radiotherapy. The half-maximal inhibitory concentration of sodium selenite in CHEK-1 cells was 3.6 µM. Sodium selenite supplementation increased the survival rate of the cells in a dose-dependent manner and enhanced the degree of cell viability at 72 h post-irradiation (P<0.05). Combined treatment with 50 nM sodium selenite and 2 gray (Gy) X-ray irradiation decreased the number of sub-G1 cells from 5.9 to 4.2% (P<0.05) and increased the proportion of G1 cells from 58.8 to 62.1%, compared with 2 Gy X-ray irradiation alone; however, this difference was not statistically significant (P=1.00). Western blot analysis revealed that treatment with 2 Gy X-ray irradiation significantly increased the expression levels of cleaved poly (ADP-ribose) polymerase (PARP; P<0.05). In addition, combined treatment with 50 nM sodium selenite and 2 Gy X-ray irradiation reduced the expression levels of cleaved PARP protein, compared with 2 Gy X-ray irradiation alone; however, this reduction was not statistically significant (P=0

  3. Protective effects of sodium selenite supplementation against irradiation-induced damage in non-cancerous human esophageal cells

    PubMed Central

    Puspitasari, Irma M.; Yamazaki, Chiho; Abdulah, Rizky; Putri, Mirasari; Kameo, Satomi; Nakano, Takashi; Koyama, Hiroshi

    2017-01-01

    The administration of radioprotective compounds is one approach to preventing radiation damage in non-cancerous tissues. Therefore, radioprotective compounds are crucial in clinical radiotherapy. Selenium is a radioprotective compound that has been used in previous clinical studies of radiotherapy. However, evidence regarding the effectiveness of selenium in radiotherapy and the mechanisms underlying the selenium-induced reduction of the side effects of radiotherapy remains insufficient. To further investigate the effectiveness of selenium in radiotherapy, the present study examined the protective effects of sodium selenite supplementation administered prior to X-ray radiation treatment in CHEK-1 non-cancerous human esophageal cells. Sodium selenite supplementation increased glutathione peroxidase 1 (GPx-1) activity in a dose- and time-dependent manner. The sodium selenite dose that induced the highest GPx-1 activity was determined to be 50 nM for 72 h prior to radiotherapy. The half-maximal inhibitory concentration of sodium selenite in CHEK-1 cells was 3.6 µM. Sodium selenite supplementation increased the survival rate of the cells in a dose-dependent manner and enhanced the degree of cell viability at 72 h post-irradiation (P<0.05). Combined treatment with 50 nM sodium selenite and 2 gray (Gy) X-ray irradiation decreased the number of sub-G1 cells from 5.9 to 4.2% (P<0.05) and increased the proportion of G1 cells from 58.8 to 62.1%, compared with 2 Gy X-ray irradiation alone; however, this difference was not statistically significant (P=1.00). Western blot analysis revealed that treatment with 2 Gy X-ray irradiation significantly increased the expression levels of cleaved poly (ADP-ribose) polymerase (PARP; P<0.05). In addition, combined treatment with 50 nM sodium selenite and 2 Gy X-ray irradiation reduced the expression levels of cleaved PARP protein, compared with 2 Gy X-ray irradiation alone; however, this reduction was not statistically significant (P=0

  4. RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration

    SciTech Connect

    Rousseau, Matthieu; Gaugler, Marie-Helene; Rodallec, Audrey; Bonnaud, Stephanie; Paris, Francois; Corre, Isabelle

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer We explore the role of RhoA in endothelial cell response to ionizing radiation. Black-Right-Pointing-Pointer RhoA is rapidly activated by single high-dose of radiation. Black-Right-Pointing-Pointer Radiation leads to RhoA/ROCK-dependent actin cytoskeleton remodeling. Black-Right-Pointing-Pointer Radiation-induced apoptosis does not require the RhoA/ROCK pathway. Black-Right-Pointing-Pointer Radiation-induced alteration of endothelial adhesion and migration requires RhoA/ROCK. -- Abstract: Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15 Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial

  5. Alcohol induced epigenetic alterations to developmentally crucial genes regulating neural stemness and differentiation

    PubMed Central

    Veazey, Kylee J.; Carnahan, Mindy N.; Muller, Daria; Miranda, Rajesh C.; Golding, Michael C.

    2013-01-01

    Background From studies using a diverse range of model organisms, we now acknowledge that epigenetic changes to chromatin structure provide a plausible link between environmental teratogens and alterations in gene expression leading to disease. Observations from a number of independent laboratories indicate ethanol has the capacity to act as a powerful epigenetic disruptor and potentially derail the coordinated processes of cellular differentiation. In this study, we sought to examine whether primary neurospheres cultured under conditions maintaining stemness were susceptible to alcohol-induced alterations of the histone code. We focused our studies on trimethylated histone 3 lysine 4 and trimethylated histone 3 lysine 27, as these are two of the most prominent post-translational histone modifications regulating stem cell maintenance and neural differentiation. Methods Primary neurosphere cultures were maintained under conditions promoting the stem cell state and treated with ethanol for five days. Control and ethanol treated cellular extracts were examined using a combination of quantitative RT-PCR and chromatin immunoprecipitation techniques. Results We find that the regulatory regions of genes controlling both neural precursor cell identity and processes of differentiation exhibited significant declines in the enrichment of the chromatin marks examined. Despite these widespread changes in chromatin structure, only a small subset of genes including Dlx2, Fabp7, Nestin, Olig2, and Pax6 displayed ethanol induced alterations in transcription. Unexpectedly, the majority of chromatin modifying enzymes examined including members of the Polycomb Repressive Complex displayed minimal changes in expression and localization. Only transcripts encoding Dnmt1, Uhrf1, Ehmt1, Ash2l, Wdr5, and Kdm1b exhibited significant differences. Conclusions Our results indicate primary neurospheres maintained as stem cells in vitro are susceptible to alcohol-induced perturbation of the

  6. Magnetism in C{sub 60} films induced by proton irradiation

    SciTech Connect

    Mathew, S.; Satpati, B.; Joseph, B.; Dev, B. N.; Nirmala, R.; Malik, S. K.; Kesavamoorthy, R.

    2007-02-15

    It is shown that polycrystalline fullerene thin films on hydrogen-passivated Si(111) substrates irradiated by 2 MeV protons display ferromagneticlike behavior at 5 K. At 300 K, both the pristine and the irradiated film show diamagnetic behavior. Magnetization data in the temperature range of 2-300 K in 1 T applied field, for the irradiated film show much stronger temperature dependence compared to the pristine film. Possible origins of ferromagneticlike signals in the irradiated films are discussed.

  7. Phenotypic and Functional Alterations of Dendritic Cells Induced by Human Herpesvirus 6 Infection

    PubMed Central

    Kakimoto, Miki; Hasegawa, Atsuhiko; Fujita, Shigeru; Yasukawa, Masaki

    2002-01-01

    Human herpesvirus 6 (HHV-6) has a tropism for T lymphocytes and monocytes/macrophages, suggesting that HHV-6 infection affects the immunosurveillance system. In the present study, we investigated the HHV-6-induced phenotypic and functional alterations of dendritic cells (DCs), which are professional antigen-presenting cells. HHV-6 infection of monocyte-derived immature DCs appeared to induce the up-regulation of CD80, CD83, CD86, and HLA class I and class II molecules, suggesting that HHV-6 infection induces the maturation of DCs. In addition, the antigen capture capacity of DCs was found to decrease following infection with HHV-6. In contrast to up-regulation of mature-DC-associated surface molecules on HHV-6-infected DCs, their capacity for presentation of alloantigens and exogenous virus antigens to T lymphocytes decreased significantly from that of uninfected DCs. In contrast, there appeared to be no reduction in the capacity for presentation of an HLA class II-binding peptide to the peptide-specific CD4+ T lymphocytes. These data indicate that HHV-6 infection induces phenotypic alterations and impairs the antigen presentation capacity of DCs. The present data also suggest that the dysfunction of HHV-6-infected DCs is attributable mainly to impairment of the antigen capture and intracellular antigen-processing pathways. PMID:12239310

  8. A Model for Precise and Uniform Pelvic- and Limb-Sparing Abdominal Irradiation to Study the Radiation-Induced Gastrointestinal Syndrome in Mice Using Small Animal Irradiation Systems

    PubMed Central

    Brodin, N. Patrik; Velcich, Anna; Guha, Chandan

    2017-01-01

    Background and Purpose: Currently, no readily available mitigators exist for acute abdominal radiation injury. Here, we present an animal model for precise and homogenous limb-sparing abdominal irradiation (LSAIR) to study the radiation-induced gastrointestinal syndrome (RIGS). Materials and Methods: The LSAIR technique was developed using the small animal radiation research platform (SARRP) with image guidance capabilities. We delivered LSAIR at doses between 14 and 18 Gy on 8- to 10-week-old male C57BL/6 mice. Histological analysis was performed to confirm that the observed mortality was due to acute abdominal radiation injury. Results: A steep dose–response relationship was found for survival, with no deaths seen at doses below 16 Gy and 100% mortality at above 17 Gy. All deaths occurred between 6 and 10 days after irradiation, consistent with the onset of RIGS. This was further confirmed by histological analysis showing clear differences in the number of regenerative intestinal crypts between animals receiving sublethal (14 Gy) and 100% lethal (18 Gy) radiation. Conclusion: The developed LSAIR technique provides uniform dose delivery with a clear dose response, consistent with acute abdominal radiation injury on histological examination. This model can provide a useful tool for researchers investigating the development of mitigators for accidental or clinical high-dose abdominal irradiation. PMID:28203121

  9. Free Radical-Induced Chain Breakage in Irradiated Aqueous Solutions of DNA

    DTIC Science & Technology

    1974-03-01

    FIGURES Figure 1. Formation of ionic phosphate in irradiated solutions of calf thymus DNA after treatment with acid phospho- monoesterase...6 Figure 2. Formation of ionic phosphate In irradiated solutions of calf thymus DNA without enzyme treatment 7 LIST OF TABLES Table...time. Labile phosphate groups produced in irradiated DNA were assayed as inorganic phosphate ( phosphate ion) following incubation of samples with acid

  10. Synthesis of atom probe experiments on irradiation-induced solute segregation in French ferritic pressure vessel steels

    NASA Astrophysics Data System (ADS)

    Auger, P.; Pareige, P.; Welzel, S.; Van Duysen, J.-C.

    2000-08-01

    Microstructural changes due to neutron irradiation cause an evolution of the mechanical properties of reactor pressure vessels (RPV) steels. This paper aims at identifying and characterising the microstructural changes which have been found to be responsible in part for the observed embrittlement. This intensive work relies principally on an atom probe (AP) study of a low Cu-level French RPV steel (Chooz A). This material has been irradiated in in-service conditions for 0-16 years in the frame of the surveillance program. Under this aging condition, solute clustering occurs (Cu, Ni, Mn, Si, P, …). In order to identify the role of copper, experiments were also carried out on Fe-Cu model alloys submitted to different types of irradiations (neutron, electron, ion). Cu-cluster nucleation appears to be directly related to the presence of displacement cascades during neutron (ion) irradiation. The operating basic physical process is not clearly identified yet. A recovery of the mechanical properties of the irradiated material can be achieved by annealing treatments (20 h at 450°C in the case of the RPV steel under study, following microhardness measurements). It has been shown that the corresponding microstructural evolution was a rapid dissolution of the high number density of irradiation-induced solute clusters and the precipitation of a very low number density of Cu-rich particles.

  11. Radiation-damage-induced phasing: a case study using UV irradiation with light-emitting diodes.

    PubMed

    de Sanctis, Daniele; Zubieta, Chloe; Felisaz, Franck; Caserotto, Hugo; Nanao, Max H

    2016-03-01

    Exposure to X-rays, high-intensity visible light or ultraviolet radiation results in alterations to protein structure such as the breakage of disulfide bonds, the loss of electron density at electron-rich centres and the movement of side chains. These specific changes can be exploited in order to obtain phase information. Here, a case study using insulin to illustrate each step of the radiation-damage-induced phasing (RIP) method is presented. Unlike a traditional X-ray-induced damage step, specific damage is introduced via ultraviolet light-emitting diodes (UV-LEDs). In contrast to UV lasers, UV-LEDs have the advantages of small size, low cost and relative ease of use.

  12. Irradiance dependence of the He-Ne laser-induced protection against UVC radiation in E. coli strains.

    PubMed

    Kohli, Roma; Gupta, Pradeep Kumar

    2003-03-01

    He-Ne laser pre-irradiation-induced protection against UVC damage was investigated in wild-type E. coli K12 strain AB1157 and its isogenic DNA repair mutant strains. At a dose of 7 kJ/m(2), pre-irradiation was observed to induce protection in recA proficient strains (AB1157 and uvrA(-) AB1886) at both the irradiances investigated (2 and 100 W/m(2)). However, at the same dose (7 kJ/m(2)), while no protection was observed at 100 W/m(2) in the recA(-) strain, some protection appeared to be there at 2 W/m(2). Mechanistic studies carried out on these strains at the two irradiances suggest that, whereas the protection observed at 100 W/m(2) is mediated by singlet oxygen, that observed at 2 W/m(2) is not. Further, the fact that protection at 100 W/m(2) was observed only in recA proficient strains suggests that it may arise due to the induction of DNA repair processes controlled by the recA gene. The latter may arise due to the oxidative stress produced by singlet oxygen generated by He-Ne laser irradiation. In contrast, the protection observed at 2 W/m(2) appears to be independent of the DNA repair proficiency of the strain.

  13. Rifaximin Alters Intestinal Bacteria and Prevents Stress-Induced Gut Inflammation and Visceral Hyperalgesia in Rats

    PubMed Central

    Xu, Dabo; Gao, Jun; Gillilland, Merritt; Wu, Xiaoyin; Song, Il; Kao, John Y.; Owyang, Chung

    2014-01-01

    Background & Aims Rifaximin is used to treat patients with functional gastrointestinal disorders, but little is known about its therapeutic mechanism. We propose that rifaximin modulates the ileal bacterial community, reduces subclinical inflammation of the intestinal mucosa, and improves gut barrier function to reduce visceral hypersensitivity. Methods We induced visceral hyperalgesia in rats, via chronic water avoidance or repeat restraint stressors, and investigated whether rifaximin altered the gut microbiota, prevented intestinal inflammation, and improved gut barrier function. Quantitative polymerase chain reaction and 454 pyrosequencing were used to analyze bacterial 16S rRNA in ileal contents from the rats. Reverse transcription, immunoblot, and histologic analyses were used to evaluate levels of cytokines, the tight junction protein occludin, and mucosal inflammation, respectively. Intestinal permeability and rectal sensitivity were measured. Results Water avoidance and repeat restraint stress each led to visceral hyperalgesia, accompanied by mucosal inflammation and impaired mucosal barrier function. Oral rifaximin altered the composition of bacterial communities in the ileum (Lactobacillus species became the most abundant) and prevented mucosal inflammation, impairment to intestinal barrier function, and visceral hyperalgesia in response to chronic stress. Neomycin also changed the composition of the ileal bacterial community (Proteobacteria became the most abundant species). Neomycin did not prevent intestinal inflammation or induction of visceral hyperalgesia induced by water avoidance stress. Conclusions Rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus. These changes prevent intestinal abnormalities and visceral hyperalgesia in response to chronic psychological stress. PMID:24161699

  14. Cross-Species Analysis of Nicotine-Induced Proteomic Alterations in Pancreatic Cells

    PubMed Central

    Paulo, Joao A.; Urrutia, Raul; Kadiyala, Vivek; Banks, Peter

    2014-01-01

    Background Toxic compounds in tobacco, such as nicotine, may have adversely affect pancreatic function. We aim to determine nicotine-induced protein alterations in pancreatic cells, which may reveal a link between nicotine exposure and pancreatic disease. Methods We compared the proteomic alterations induced by nicotine treatment in cultured pancreatic cells (mouse, rat and human stellate cells and human duct cells) using mass spectrometry-based techniques, specifically GeLC-MS/MS and spectral counting. Results We identified thousands of proteins in pancreatic cells, hundreds of which were identified exclusively or in higher abundance in either nicotine-treated or untreated cells. Inter-species comparisons of stellate cell proteins revealed several differentially-abundant proteins (in nicotine treated versus untreated cells) common among the 3 species. Proteins appearing in all nicotine-treated stellate cells include amyloid beta (A4), procollagen type VI alpha 1, integral membrane protein 2B,and Toll interacting protein. Conclusions Proteins which were differentially expressed upon nicotine treatment across cell lines, were enriched in certain pathways, including nAChR, cytokine, and integrin signaling. At this analytical depth, we conclude that similar pathways are affected by nicotine, but alterations at the protein level among stellate cells of different species vary. Further interrogation of such pathways will lead to insights into the potential effect of nicotine on pancreatic cells at the biomolecular level and the extension of this concept to the effect of nicotine on pancreatic disease. PMID:23456891

  15. Alterations in left ventricular diastolic function in conscious dogs with pacing-induced heart failure

    NASA Technical Reports Server (NTRS)

    Komamura, K.; Shannon, R. P.; Pasipoularides, A.; Ihara, T.; Lader, A. S.; Patrick, T. A.; Bishop, S. P.; Vatner, S. F.

    1992-01-01

    We investigated in conscious dogs (a) the effects of heart failure induced by chronic rapid ventricular pacing on the sequence of development of left ventricular (LV) diastolic versus systolic dysfunction and (b) whether the changes were load dependent or secondary to alterations in structure. LV systolic and diastolic dysfunction were evident within 24 h after initiation of pacing and occurred in parallel over 3 wk. LV systolic function was reduced at 3 wk, i.e., peak LV dP/dt fell by -1,327 +/- 105 mmHg/s and ejection fraction by -22 +/- 2%. LV diastolic dysfunction also progressed over 3 wk of pacing, i.e., tau increased by +14.0 +/- 2.8 ms and the myocardial stiffness constant by +6.5 +/- 1.4, whereas LV chamber stiffness did not change. These alterations were associated with increases in LV end-systolic (+28.6 +/- 5.7 g/cm2) and LV end-diastolic stresses (+40.4 +/- 5.3 g/cm2). When stresses and heart rate were matched at the same levels in the control and failure states, the increases in tau and myocardial stiffness were no longer observed, whereas LV systolic function remained depressed. There were no increases in connective tissue content in heart failure. Thus, pacing-induced heart failure in conscious dogs is characterized by major alterations in diastolic function which are reversible with normalization of increased loading condition.

  16. Regional alterations of type I collagen in rat tibia induced by skeletal unloading

    NASA Technical Reports Server (NTRS)

    Shiiba, Masashi; Arnaud, Sara B.; Tanzawa, Hideki; Kitamura, Eiji; Yamauchi, Mitsuo

    2002-01-01

    Skeletal unloading induces loss of mineral density in weight-bearing bones that leads to inferior bone mechanical strength. This appears to be caused by a failure of bone formation; however, its mechanisms still are not well understood. The objective of this study was to characterize collagen, the predominant matrix protein in bone, in various regions of tibia of rats that were subjected to skeletal unloading by 4 weeks tail suspension. Sixteen male Sprague-Dawley rats (4 months old) were divided into tail suspension and ambulatory controls (eight rats each). After the tail suspension, tibias from each animal were collected and divided into five regions and collagen was analyzed. The collagen cross-linking and the extent of lysine (Lys) hydroxylation in unloaded bones were significantly altered in proximal epiphysis, diaphysis, and, in particular, proximal metaphysis but not in distal regions. The pool of immature/nonmineralized collagen measured by its extractability with a chaotropic solvent was significantly increased in proximal metaphysis. These results suggest that skeletal unloading induced an accumulation of post-translationally altered nonmineralized collagen and that these changes are bone region specific. These alterations might be caused by impaired osteoblastic function/differentiation resulting in a mineralization defect.

  17. Neuroplastic reactivity of fish induced by altered gravity conditions: a review of recent results

    NASA Astrophysics Data System (ADS)

    Rahmann, H.; Anken, R. H.

    A review is being presented concerning behavioural, biochemical, histochemical and electronmicroscopical data on the influence of altered gravitational forces on the swimming performance and on the neuronal differentiation of the brain of cichlid fish larvae and adult swordtail fish that had been exposed to hyper-gravity (3g in laboratory centrifuges), hypo-gravity (>10^-2g in a fast-rotating clinostat) and to near weightlessness (10^-4g aboard the spacelab D-2 mission). After long-term alterations of gravity (and parallel light deprivation), initial disturbances in the swimming behaviour followed by a stepwise regain of normal swimming modes are induced. Parallely, neuroplastic reactivities on different levels of investigation were found, such as adaptive alterations of activities of various enzymes in whole brain as well as in specific neuronal integration centers and an intraneuronal reactivity on ultrastructural level in individual brain parts and in the sensory epithelia of the inner ear. Taken together, these data reveal distinct adaptive neuroplastic reactions of fish to altered gravity conditions.

  18. Role of neutrophilic inflammation in ozone-induced epithelial alterations in the nasal airways of rats

    NASA Astrophysics Data System (ADS)

    Cho, Hye Youn

    Ozone is a principal oxidant air pollutant in photochemical smog. Epithelial cells lining the centriacinar region of lung and the proximal aspects of nasal passage are primary target sites for ozone-induced injury in laboratory animals. Acute exposure of rats to high ambient concentrations of ozone (e.g., 0.5 ppm) results in neutrophilic inflammation, epithelial hyperplasia and mucous cell metaplasia (MCM) in the nasal transitional epithelium (NTE) lining the proximal nasal airways. The principal purpose of the present study was to investigate the role of pre-metaplastic cellular responses, especially neutrophilic inflammation, in the pathogenesis of ozone-induced MCM in rat NTE. For this purpose, three specific hypotheses-based whole-animal inhalation studies were conducted. Male F344/N rats were exposed in whole-body inhalation chambers to 0 (filtered air) or 0.5 ppm ozone for 1-3 days (8 h/day). Histochemical, immunochemical, molecular and morphometric techniques were used to investigate the ozone-induced cellular and molecular events in the NTE. Two in vitro studies were also conducted to examine the effects of ozone-inducible cytokines (i.e., tumor necrosis factor-alpha; TNF- a, and interleukin-6; IL-6) on mucin gene (rMuc-5AC) expression. Ozone induced a rapid increase of rMuc-5AC mRNA in nasal tissues within hours after the start of exposure. It preceded the appearance of MCM, and persisted with MCM. Ozone-induced neutrophilic inflammation accompanied the mucin gene upregulation, but was resolved when MCM first appeared in the NTE. Antibody-mediated depletion of circulating neutrophils attenuated ozone-induced MCM, although it did not affect the ozone-induced epithelial hyperplasia and mucin mRNA upregulation. In another study, it was found that preexisting neutrophilic rhinitis induced by endotoxin augmented the ozone-induced MCM. However, pre-existing rhinitis did not alter the severity of ozone-induced epithelial hyperplasia and mucin gene upregulation

  19. Non-random distribution of DNA double-strand breaks induced by particle irradiation

    NASA Technical Reports Server (NTRS)

    Lobrich, M.; Cooper, P. K.; Rydberg, B.; Chatterjee, A. (Principal Investigator)

    1996-01-01

    Induction of DNA double-strand breaks (dsbs) in mammalian cells is dependent on the spatial distribution of energy deposition from the ionizing radiation. For high LET particle radiations the primary ionization sites occur in a correlated manner along the track of the particles, while for X-rays these sites are much more randomly distributed throughout the volume of the cell. It can therefore be expected that the distribution of dsbs linearly along the DNA molecule also varies with the type of radiation and the ionization density. Using pulsed-field gel and conventional gel techniques, we measured the size distribution of DNA molecules from irradiated human fibroblasts in the total range of 0.1 kbp-10 Mbp for X-rays and high LET particles (N ions, 97 keV/microns and Fe ions, 150 keV/microns). On a mega base pair scale we applied conventional pulsed-field gel electrophoresis techniques such as measurement of the fraction of DNA released from the well (FAR) and measurement of breakage within a specific NotI restriction fragment (hybridization assay). The induction rate for widely spaced breaks was found to decrease with LET. However, when the entire distribution of radiation-induced fragments was analysed, we detected an excess of fragments with sizes below about 200 kbp for the particles compared with X-irradiation. X-rays are thus more effective than high LET radiations in producing large DNA fragments but less effective in the production of smaller fragments. We determined the total induction rate of dsbs for the three radiations based on a quantitative analysis of all the measured radiation-induced fragments and found that the high LET particles were more efficient than X-rays at inducing dsbs, indicating an increasing total efficiency with LET. Conventional assays that are based only on the measurement of large fragments are therefore misleading when determining total dsb induction rates of high LET particles. The possible biological significance of this non

  20. Preparation of reduced graphene oxide by infrared irradiation induced photothermal reduction

    NASA Astrophysics Data System (ADS)

    Guo, Honglei; Peng, Mao; Zhu, Zhongming; Sun, Lina

    2013-09-01

    We present a green and scalable route toward the formation of reduced graphene oxide (r-GO) by photothermal reduction induced by infrared (IR) irradiation, utilizing a bathroom IR lamp as the source of IR light. Thermogravimetric analysis, Raman, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the reduction of r-GO by IR light. Ultraviolet-visible-infrared spectra indicate that adsorption of IR light by original GO films is less than that of UV and visible light; but when GO is exposed to IR light, its adsorption of IR light increases very rapidly with time. The influence of the power density of the IR light on the structure and properties of r-GO was investigated. At high IR power density, the reduction reaction was so fierce that r-GO became highly porous due to the rapid degassing and exfoliation of GO sheets. The r-GO powder revealed good performance as the anode material for lithium ion batteries. At relatively low IR power density, the reduction process was found to be mild but relatively slow. Crack-free and uniform conductive r-GO thin films with a volume conductivity of 1670 S m-1 were then prepared by two-step IR irradiation, i.e. first at low IR power density and then at high IR power density. Moreover, the r-GO films were also observed to exhibit obvious and reversible IR light-sensing behavior.We present a green and scalable route toward the formation of reduced graphene oxide (r-GO) by photothermal reduction induced by infrared (IR) irradiation, utilizing a bathroom IR lamp as the source of IR light. Thermogravimetric analysis, Raman, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the reduction of r-GO by IR light. Ultraviolet-visible-infrared spectra indicate that adsorption of IR light by original GO films is less than that of UV and visible light; but when GO is exposed to IR light, its adsorption of IR light increases very rapidly with time. The influence of the power