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406 records returned

Quantification of radiation-induced single-strand breaks in plasmid DNA using a TUNEL/ELISA-based assay.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To accurately quantify the number of single-strand breaks (SSBs) induced in plasmid DNA molecules after irradiation, a new type of assay methodology has been explored. The new method is based on the TUNEL (terminal deoxynucleotide transferase dUTP nick end-labeling) assay that was adopted for use under ELISA (enzyme-linked immunosorbent assay) conditions. The assay was found to both improve the quantification and reduce the uncertainties in measurement of SSBs compared with the commonly used agarose gel electrophoresis (AGE) method. Together with AGE, the new method can provide the additional data necessary for an accu...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Smiałek MA, Moore SA, Mason NJ, Shuker DE Tags: Radiat Res Source Type: journals

5,6-Dihydrothymine impairs the base excision repair pathway of a closely opposed AP site or single-strand break.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Ionizing radiation can induce clustered DNA damage (two or more lesions formed within one to two helical turns of DNA by passage of a single ionization track). Using oligonucleotide constructs containing clustered DNA lesions at defined positions, evidence is presented demonstrating that a persistent 5,6-dihydrothymine (DHT) lesion reduces the efficiency of rejoining, in mammalian nuclear extracts, of an opposing AP site or SSB when within 5 bp. The efficiency of repair of the SSB is reduced when DHT is present on the opposing strand in both the 3' and 5' orientation; however, the efficiency of the repair of the AP sit...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Byrne S, Cunniffe S, O'Neill P, Lomax ME Tags: Radiat Res Source Type: journals

Comparative analysis of cell killing and autosomal mutation in mouse kidney epithelium exposed to 1 GeV/nucleon iron ions in vitro or in situ.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study addresses the cytotoxic and mutagenic effects of 1 GeV/nucleon iron ions in mouse kidney epithelium. Mutant fractions were measured for an endogenous autosomal locus (Aprt) that detects all types of mutagenic events contributing to human cancer. Results for kidneys irradiated in situ are compared with results for kidney cells from the same strain exposed in vitro. The results demonstrate dose-dependent cell killing in vitro and for cells explanted 3-4 months postirradiation in situ, but in situ exposures were less likely to result in cell death than in vitro exposures. Prolonged incubation in situ (8-9 months) f...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Kronenberg A, Gauny S, Kwoh E, Connolly L, Dan C, Lasarev M, Turker MS Tags: Radiat Res Source Type: journals

Comparison of autosomal mutations in mouse kidney epithelial cells exposed to iron ions in situ or in culture.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Exposure to accelerated iron ions represents a significant health risk in the deep space environment because it induces mutations that can cause cancer. A mutation assay was used to determine the full spectrum of autosomal mutations induced by exposure to 2 Gy of 1 GeV/nucleon iron ions in intact kidney epithelium, and the results were compared with mutations induced in cells of a kidney epithelial cell line exposed in vitro. A molecular analysis for loss of heterozygosity (LOH) for polymorphic loci on chromosome 8, which harbors Aprt, demonstrated iron-ion induction of mitotic recombination, interstitial deletion, and...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Turker MS, Connolly L, Dan C, Lasarev M, Gauny S, Kwoh E, Kronenberg A Tags: Radiat Res Source Type: journals

No evidence for a different RBE between pulsed and continuous 20 MeV protons.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To obtain greater insight into the future potential of tumor radiotherapy using proton beams generated from high-intensity lasers, it is important to characterize the ionization quality of the new beams by measuring the relative biological effectiveness (RBE) under conditions where the full dose at one irradiation site will be deposited by a few proton pulses less than 1 ns in duration. HeLa cells attached to a Mylar foil were irradiated with 70 kV X rays to obtain a reference dose-response curve or with 3 Gy of 20 MeV protons at the Munich tandem accelerator (Garching), either using a continuous mode where a cell samp...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Schmid TE, Dollinger G, Hauptner A, Hable V, Greubel C, Auer S, Friedl AA, Molls M, Röper B Tags: Radiat Res Source Type: journals

Cyclosporin A inhibits UV-radiation-induced membrane damage but is unable to inhibit carboxyatractyloside-induced permeability transition.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This work was undertaken to gain further information on the chemical characteristics of the membrane entity involved in the formation of the nonspecific pore. Mitochondria were subjected to oxidative stress by exposure to UV radiation. The results indicate that ultraviolet C radiation induces structural modifications in the adenine nucleotide translocase that lead to membrane permeability transition. Membrane leakage was assessed by measuring mitochondrial Ca2+ transport, the transmembrane electric gradient, and mitochondrial swelling. UV-irradiated mitochondria were unable to retain matrix Ca2+ or to maintain a high l...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: García N, Zazueta C, El-Hafidi M, Pavón N, Martínez-Abundis E, Hernández-Esquivel L, Chávez E Tags: Radiat Res Source Type: journals

Decrease in tumor cell oxygen consumption after treatment with vandetanib (ZACTIMA; ZD6474) and its effect on response to radiotherapy.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We investigated the early effects of vandetanib (ZACTIMA; ZD6474), an inhibitor of VEGFR-dependent angiogenesis, on tumor oxygenation and on the possible consequences of combining vandetanib with radiotherapy. Tumor oxygenation, perfusion, cellular consumption of oxygen, and radiation sensitivity were studied in transplantable liver tumors after daily doses of vandetanib (25 mg kg(-1) i.p.). Measurements of oxygenation (pO(2)) and tumor cell oxygen consumption were carried out using electron paramagnetic resonance (EPR), and perfusion parameters were assessed by dynamic contrast-enhanced magnetic resonance imaging (DCE...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Ansiaux R, Dewever J, Grégoire V, Feron O, Jordan BF, Gallez B Tags: Radiat Res Source Type: journals

Radiotherapy in conjunction with 7-hydroxystaurosporine: a multimodal approach with tumor pO2 as a potential marker of therapeutic response.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We report the effect of 20 Gy radiation given in conjunction with UCN-01 on the pO2 and growth of subcutaneous RIF-1 tumors. Multisite EPR oximetry was used for repeated, non-invasive tumor pO2 measurements. The effect of UCN-01 and/or 20 Gy on tumor pO2 and tumor volume was investigated to determine therapeutic outcomes. Untreated RIF-1 tumors were hypoxic with a tissue pO2 of 5-7 mmHg. Treatment with 20 Gy or UCN-01 significantly reduced tumor growth, and a modest increase in tumor pO2 was observed in tumors treated with 20 Gy. However, irradiation with 20 Gy 12 h after UCN-01 treatment resulted in a significant inhibiti...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Khan N, Mupparaju SP, Hou H, Lariviere JP, Demidenko E, Swartz HM, Eastman A Tags: Radiat Res Source Type: journals

In vivo assessment of dose volume and dose gradient effects on the tolerance dose of small liver volumes after single-fraction high-dose-rate 192Ir irradiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of this study was to assess the dependence of the normal liver tissue threshold dose on the volume exposed and the catheter geometry-dependent dose gradients for single-fraction high-dose-rate brachytherapy of malignant liver lesions. A total of 50 patients with malignant liver tumors treated with CT-guided high-dose-rate 192Ir brachytherapy were included. Dose planning was performed using a three-dimensional CT data set acquired after percutaneous applicator positioning. Magnetic resonance imaging (MRI), performed 6 and 12 weeks after therapy, was analyzed retrospectively. All MRI data sets were merged with 3D...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Wybranski C, Seidensticker M, Mohnike K, Kropf S, Wust P, Ricke J, Lüdemann L Tags: Radiat Res Source Type: journals

Application of high-resolution 1H MAS NMR spectroscopy to the analysis of intact bones from mice exposed to gamma radiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Herein we demonstrate that high-resolution magic angle spinning (MAS) 1H NMR can be used to profile the pathology of bone marrow rapidly and with minimal sample preparation. The spectral resolution obtained allows several metabolites to be analyzed quantitatively. The level of NMR-detectable metabolites in the epiphysis + metaphysis sections of mouse femur were significantly higher than that observed in the diaphysis of the same femur. The major metabolite damage to bone marrow resulting from either 3.0 Gy or 7.8 Gy of whole-body gamma radiation 4 days after exposure were (1) decreased total choline content, (2) increa...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Zhang Q, Hu JZ, Rommereim DN, Murphy MK, Phipps RP, Huso DL, Dicello JF Tags: Radiat Res Source Type: journals

A confirmation study of Russian and Ukrainian data on effects of 2450 MHz microwave exposure on immunological processes and teratology in rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In a series of Russian and Ukrainian papers published from 1974-1986, it was reported that 30-day whole-body exposures to continuous-wave (CW) radiofrequency (RF) radiation at 2375 MHz and 5 W/m(2) disrupted the antigenic structure of rat brain tissue. The authors suggested that this action caused an autoimmune response in exposed animals. Moreover, these studies reported that blood serum from exposed rats injected into intact nonexposed female rats on the 10th day of pregnancy led to increased postimplantation embryo mortality and decreased fetus size and body weight. Because the results of these studies served in par...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: de Gannes FP, Taxile M, Duleu S, Hurtier A, Haro E, Geffard M, Ruffié G, Billaudel B, Lévêque P, Dufour P, Lagroye I, Veyret B Tags: Radiat Res Source Type: journals

Gamma knife radiosurgery treatment planning for small animals using high-resolution 7T micro-magnetic resonance imaging.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Gamma Knife stereotactic radiosurgery is capable of providing small, high gradient dose distributions to a target with a high level of precision, which makes it an excellent choice for studies of focal irradiations with small animals. However, the Gamma Knife stereotactic radiosurgery process makes use of a human-sized fiducial marker system that requires a field of view of at least 200 mm(2) to relate computed tomography and magnetic resonance images to the Gamma Knife treatment planning software. Thus the Gamma Knife fiducial marker system is five to six times larger than a typical small animal subject. The required ...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Wiant D, Atwood TF, Olson J, Papagikos M, Forbes ME, Riddle DR, Bourland JD Tags: Radiat Res Source Type: journals

An alpha-particle irradiator for radiobiological research and its implementation for bystander effect studies.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
An experimental system based on an improved version of an existing alpha-particle irradiator has been developed for radiobiological studies, in particular those investigating bystander effects. It consists of a 20-mm-diameter stainless steel chamber that can be equipped alternatively with 244Cm or 241Am sources of different activities. Mylar-based petri dishes 56 mm in diameter were specially designed to house adaptors for permeable membrane inserts that reproduce the geometry of commercial cell culture insert companion plates. Characterization of the radiation field at the cell level was performed by experimental meas...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Esposito G, Antonelli F, Belli M, Campa A, Simone G, Sorrentino E, Tabocchini MA Tags: Radiat Res Source Type: journals

Therapeutic dose from a pyroelectric electron accelerator.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We report on the evaluation of the feasibility of using a portable pyroelectric electron accelerator to deliver a therapeutic dose to tissue. Such a device could be mass produced as a handheld, battery-powered instrument. Experiments were conducted with several crystal sizes in which the crystal was heated inside a vacuum chamber and the emitted electrons were allowed to penetrate a thin beryllium window into the surrounding air. A Faraday cup was used to count the number of electrons that exited the window. The energy of these electrons was determined by measuring the energy spectrum of the X rays that resulted from the e...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Fullem TZ, Fazel KC, Geuther JA, Danon Y Tags: Radiat Res Source Type: journals

Lack of teratogenicity after combined exposure of pregnant mice to CDMA and WCDMA radiofrequency electromagnetic fields.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Concern about the possible adverse effects of radiofrequency (RF)-field exposure on public health has increased because of the extensive use of wireless mobile phones and other telecommunication devices in daily life. The murine fetus is a very sensitive indicator of the effects of stress or stimuli in the environment. Therefore, we investigated the teratogenic effects of multi-signal radiofrequency electromagnetic fields (RF EMFs) on mouse fetuses. Pregnant mice were simultaneously exposed to two types of RF signals, single code division multiple access (CDMA) and wideband code division multiple access (WCDMA). Mice r...
Source: Radiation Research - November 1, 2009 Category: Physics Authors: Lee HJ, Lee JS, Pack JK, Choi HD, Kim N, Kim SH, Lee YS Tags: Radiat Res Source Type: journals

Recognition of O6MeG Lesions by MGMT and Mismatch Repair Proficiency may be a Prerequisite for Low-Dose Radiation Hypersensitivity.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Low-dose hyper-radiosensitivity (HRS) is the phenomenon whereby cells exposed to radiation doses of less than approximately 0.5 Gy exhibit increased cell killing relative to that predicted from back-extrapolating high-dose survival data using a linear-quadratic model. While the exact mechanism remains to be elucidated, the involvement of several molecular repair pathways has been documented. These processes in turn are also associated with the response of cells to O6-methylguanine (O6MeG) lesions. We propose a model in which the level of low-dose cell killing is determined by the efficiency of both pre-replica...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Martin L, Marples B, Coffey M, Lawler M, Hollywood D, Marignol L Tags: Radiat Res Source Type: journals

Synthetic protection short interfering RNA screen reveals glyburide as a novel radioprotector.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract To assist in screening existing drugs for use as potential radioprotectors, we used a human unbiased 16,560 short interfering RNA (siRNA) library targeting the druggable genome. We performed a synthetic protection screen that was designed to identify genes that, when silenced, protected human glioblastoma T98G cells from gamma-radiation-induced cell death. We identified 116 candidate protective genes, then identified 10 small molecule inhibitors of 13 of these candidate gene products and tested their radioprotective effects. Glyburide, a clinically used second-generation hypoglycemic drug, effectively decrease...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Jiang J, McDonald PR, Dixon TM, Franicola D, Zhang X, Nie S, Epperly LD, Huang Z, Kagan VE, Lazo JS, Epperly MW, Greenberger JS Tags: Radiat Res Source Type: journals

High content analysis of human fibroblast cell cultures after exposure to space radiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Space travel imposes risks to human health, in large part by the increased radiation levels compared to those on Earth. To understand the effects of space radiation on humans, it is important to determine the underlying cellular mechanisms. While general dosimetry describes average radiation levels accurately, it says little about the actual physiological impact and does not provide biological information about individual cellular events. In addition, there is no information about the nature and magnitude of a systemic response through extra- and intercellular communication. To assess the stress response in hu...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Dieriks B, De Vos W, Meesen G, Van Oostveldt K, De Meyer T, Ghardi M, Baatout S, Van Oostveldt P Tags: Radiat Res Source Type: journals

Induction of Cytokine Gene Expression in Human Thyroid Epithelial Cells Irradiated with HZE Particles (Iron Ions).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Gene expression profiles were examined using cDNA microarray technology in human thyroid epithelial (Htori-3) cells exposed to a low, non-toxic dose (10 cGy) of radiation from HZE particles in the form of iron ions in the absence or presence of selenomethionine (SeM). A total of 215 genes were differentially regulated 2 h after exposure to a 10-cGy dose of iron-ion radiation. In the microarray analysis, SeM had profound effects on the radiation-induced expression of several specific genes, which includes PLAU, IGFBP3, FOLR1, B4GALT1 and COL1A1. Of particular interest to us was a gene cluster, "secreted protein...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Sanzari JK, Nuth M, Kennedy AR Tags: Radiat Res Source Type: journals

Reversible effect of magnetic fields on human lymphocyte activation patterns: different sensitivity of naive and memory lymphocyte subsets.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the effects of magnetic fields after 24 and 48 h of cell culture were analyzed. We found that the CD4(+)CD45RA(-) T subset were more sensitive after 2 h of exposure. Decreases in the release/content of IFN-gamma, in cell proliferation and in intracellular free calcium concentrations were observed in exposed CD4(+)CD45RA(-) T cells compared to CD4(+)CD45RA(+) T cells. The results suggest that exposure to the magnetic fields induces a delay in the response to stimulants and that modifications are rapidly reversible, at least after a short exposure. PMID: 19772465 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Salerno S, La Mendola C, La Manna MP, Casto AL, Caccamo N, Salerno A Tags: Radiat Res Source Type: journals

Photodynamic treatment of culture medium containing serum induces long-lasting toxicity in vitro.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study we endeavored to determine whether the application of PDT to culture medium could affect cell survival. Culture medium [RPMI 1640 supplemented with fetal calf serum (FCS)] was incubated with Rose Bengal and irradiated before being added to cells for various contact times as a replacement for untreated medium. Cells were then kept in darkness until the survival assay. Treated medium reduced cell survival by up to 40% after 30 min of contact for 10 microg/ml of Rose Bengal and 20 J/cm(2). Rose Bengal or m-THPC alone or irradiated in water had no effect. This effect was dependent on the doses of Rose Bengal and ...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Olivier D, Douillard S, Lhommeau I, Patrice T Tags: Radiat Res Source Type: journals

Chk2 Protects against Radiation-Induced Genomic Instability.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract The murine Chk2 kinase is activated after exposure to ionizing radiation and is necessary for p53-dependent apoptosis, but the role Chk2 plays in determining genomic stability is poorly understood. By analyzing the sensitivity of Chk2-deficient murine and human cells to a range of DNA-damaging agents, we show that Chk2 deficiency results in resistance to agents that generate double-strand breaks but not to other forms of damage. Surprisingly, the absence of Chk2 results in increased sensitivity to UV-radiation-induced DNA damage. Defective apoptosis after radiation-induced DNA damage may result in genomic inst...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Maclaren A, Slavin D, McGowan CH Tags: Radiat Res Source Type: journals

Biological effects of high-energy neutrons measured in vivo using a vertebrate model.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Interaction of solar protons and galactic cosmic radiation with the atmosphere and other materials produces high-energy secondary neutrons from below 1 to 1000 MeV and higher. Although secondary neutrons may provide an appreciable component of the radiation dose equivalent received by space and high-altitude air travelers, the biological effects remain poorly defined, particularly in vivo in intact organisms. Here we describe the acute response of Japanese medaka ( Oryzias latipes ) embryos to a beam of high-energy spallation neutrons that mimics the energy spectrum of secondary neutrons encountered aboard spa...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Kuhne WW, Gersey BB, Wilkins R, Wu H, Wender SA, George V, Dynan WS Tags: Radiat Res Source Type: journals

Deoxyribonuclease I is Essential for DNA Fragmentation Induced by Gamma Radiation in Mice.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, our results suggested that DNase I-mediated mechanism of DNA damage and subsequent tissue injury are essential in gamma-radiation-induced cell death in radiosensitive organs. PMID: 19772469 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Apostolov EO, Soultanova I, Savenka A, Bagandov OO, Yin X, Stewart AG, Walker RB, Basnakian AG Tags: Radiat Res Source Type: journals

Biodistribution of (10)B for Boron Neutron Capture Therapy (BNCT) in a Mouse Model after Injection of Sodium Mercaptoundecahydro-closo-dodecaborate and l-para-Boronophenylalanine.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study compares in a mouse model the (10)B uptake in different organs as delivered by l-para-boronophenylalanine (BPA, 700 mg/kg body weight, i.p.) and/or sodium mercaptoundecahydro-closo-dodecaborate (BSH, 200 mg/kg body weight, i.p). After BSH injection, the (10)B concentration was high in kidneys (20 +/- 12 microg/g) and liver (20 +/- 12 microg/g) but was low in brain (1.0 +/- 0.8 microg/g) and muscle (1.9 +/- 1.2 microg/g). After BPA injection, the (10)B concentration was high in kidneys (38 +/- 25 microg/g) and spleen (17 +/- 8 microg/g) but low in brain (5 +/- 3 microg/g). After combined BPA and BSH injection, th...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Wittig A, Huiskamp R, Moss RL, Bet P, Kriegeskotte C, Scherag A, Hilken G, Sauerwein WA Tags: Radiat Res Source Type: journals

Gene expression changes in medical workers exposed to radiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract The use of nuclear resources for medical purposes causes considerable concern about occupational exposure. Nevertheless, little information is available regarding the effects of low-dose irradiations protracted over time. We used oligomicroarrays to identify the genes that are transcriptionally regulated by persistent exposure to extremely low doses of ionizing radiation in 28 exposed professionals (mean cumulative effective dose +/- SD, 19 +/- 38 mSv) compared with a matched sample of nonexposed subjects. We identified 256 modulated genes from peripheral blood mononuclear cells profiles, and the main biologic...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Morandi E, Severini C, Quercioli D, Perdichizzi S, Mascolo MG, Horn W, Vaccari M, Nucci MC, Lodi V, Violante FS, Bolognesi C, Grilli S, Silingardi P, Colacci A Tags: Radiat Res Source Type: journals

Radiation risk modeling of thyroid cancer with special emphasis on the chernobyl epidemiological data.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Two recent studies analyzed thyroid cancer incidence in Belarus and Ukraine during the period from 1990 to 2001, for the birth cohort 1968 to 1985, and the related (131)I exposure associated with the Chernobyl accident in 1986. Contradictory age-at-exposure and time-since-exposure effect modifications of the excess relative risk (ERR) were reported. The present study identifies the choice of baseline modeling method as the reason for the conflicting results. Various quality-of-fit criteria favor a parametric baseline model to various categorical baseline models. The model with a parametric baseline results in ...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Walsh L, Jacob P, Kaiser JC Tags: Radiat Res Source Type: journals

Modification of Mortality and Tumorigenesis by Tocopherol-mono-glucoside (TMG) Administered after X Irradiation in Mice and Rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract The effects of TMG [2-(alpha-d-glucopyranosyl) methyl-2,5,7,8-tetramethylchroman-6-ol], a water-soluble vitamin E derivative, administered after irradiation on the mortality of X-irradiated mice and on the development of tumors in the mammary and pituitary glands in rats were investigated. When TMG (650 mg/kg) was administered intraperitoneally (i.p.) to C3H mice immediately after whole-body exposure to 7 Gy radiation, the 30-day survival was significantly higher than that of the control mice. The i.p. administration of TMG at 4 h after irradiation significantly improved survival compared to that of the contro...
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Ueno M, Inano H, Onoda M, Murase H, Ikota N, Kagiya TV, Anzai K Tags: Radiat Res Source Type: journals

The Age at which Cancer Occurs-An Overlooked Parameter!Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 19772474 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Ducoff HS Tags: Radiat Res Source Type: journals

Patricia w. Durbin (1927-2009).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 19772475 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - September 25, 2009 Category: Physics Authors: Tenforde TS Tags: Radiat Res Source Type: journals

Radiofrequency radiation and gene/protein expression: a review.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Mobile telecommunications have developed considerably in recent years. With the proliferation of wireless technologies, there is much public anxiety about the potential health impact associated with exposure to radiofrequency (RF) radiation from these novel products. Contradictory scientific evidence, often reported in the popular media, has further fueled public concern. Some epidemiological studies have reported that ipsilateral use of a mobile phone is associated with an increased risk for brain tumors, while other studies have reported an association between brain tumor risk and mobile phone use for longer...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: McNamee JP, Chauhan V Tags: Radiat Res Source Type: journals

Distribution of double-strand breaks induced by ionizing radiation at the level of single DNA molecules examined by atomic force microscopy.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We present the results of radiation-induced fragmentation of plasmid DNA analyzed by atomic force microscopy (AFM) to allow the visualization of individual DNA molecules. Linear PhiX174 plasmid DNA was exposed to a wide range of doses of low-LET X rays and high-LET carbon, nickel and uranium ions. The induced DNA fragments were detected and measured based on the recorded AFM images and fragment length distributions were derived for each radiation type and dose. The results show a dose- and radiation type-dependent DNA fragmentation with a significantly larger fraction of short fragments produced by high-LET radiation compa...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Psonka-Antonczyk K, Elsässer T, Gudowska-Nowak E, Taucher-Scholz G Tags: Radiat Res Source Type: journals

Induction of DNA Strand Breaks, Base Lesions and Clustered Damage Sites in Hydrated Plasmid DNA Films by Ultrasoft X Rays around the Phosphorus K Edge.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract To characterize the DNA damage induced by K-shell ionization of phosphorus atom in DNA backbone on the level of hydration, the yields of DNA strand breaks and base lesions arising from the interaction of ultrasoft X rays with energies around the phosphorus K edge were determined using dry and fully hydrated pUC18 plasmid DNA samples. Base lesions and bistranded clustered DNA damage sites were revealed by postirradiation treatment with the base excision repair proteins endonuclease III (Nth) and formamidopyrimidine-DNA glycosylase (Fpg). The yield of prompt single-strand breaks (SSBs) with dry DNA irradiated at...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Yokoya A, Cunniffe SM, Watanabe R, Kobayashi K, O'Neill P Tags: Radiat Res Source Type: journals

Low-dose radiation-induced senescent stromal fibroblasts render nearby breast cancer cells radioresistant.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract In addition to cell cycle arrest, DNA repair or/and apoptosis, ionizing radiation can also induce premature senescence, which could lead to very different biological consequences depending on the cell type. We show in this report that low-dose radiation-induced senescent stromal fibroblasts stimulate proliferation of cocultured breast carcinoma cells. Such effects of senescent fibroblasts appear to result from their ability to induce the expression in carcinoma cells of mitotic genes and subsequent mitotic division. The elevated proliferation of breast carcinoma cells correlates with resistance to radiation as...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Tsai KK, Stuart J, Chuang YY, Little JB, Yuan ZM Tags: Radiat Res Source Type: journals

Radiation sensitivities in the terminal stages of megakaryocytic maturation and platelet production.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract These studies examined the effects of X radiation and interleukin 3 (IL-3), which is an effective cytokine for the generation of megakaryocytopoiesis from X-irradiated hematopoietic stem/progenitor cells, on the terminal process of human megakaryocytopoiesis and thrombopoiesis. Mature megakaryocytes were induced by culturing CD34(+) cells from normal human peripheral blood in a serum-free liquid culture stimulated with thrombopoietin. The experiments contained the following groups: control cultures with nonirradiated cells incubated for 15 days; cultures treated with IL-3 on day 7 or day 11, cultures irradiate...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Monzen S, Osuda K, Miyazaki Y, Hayashi N, Takahashi K, Kashiwakura I Tags: Radiat Res Source Type: journals

Geldanamycin Analog 17-DMAG Inhibits iNOS and Caspases in Gamma-Irradiated Human T Cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Inducible nitric oxide synthase (iNOS) expression and NO production increase after radiation exposure. We showed previously that inhibiting iNOS expression prevents hemorrhage injury; we therefore investigated whether inhibiting iNOS expression also limits radiation injury. Human Jurkat T cells were exposed to gamma radiation (2, 4, 6 or 8 Gy), and cell lysates were collected for analysis at selected times afterward. Radiation exposure increased iNOS expression within 4 h postirradiation by increasing the levels of the iNOS transcription factors NF-kappaB and KLF6. By 24 h postirradiation cell viability was re...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Kiang JG, Smith JT, Agravante NG Tags: Radiat Res Source Type: journals

Protective Effect of Lecithinized SOD on Reactive Oxygen Species-Induced Xerostomia.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we examined the ability of the antioxidant superoxide dismutase (SOD) to restore radiation-induced salivary gland dysfunction using a mouse model of radiation-induced salivary gland hypofunction and ultraviolet B (UVB)-irradiated human salivary gland cells. We administered lecithinized SOD (PC-SOD) prior to and after irradiation and measured the amount of saliva secreted. To confirm ROS generation, flow cytometry was performed using an oxidant-sensitive fluorescent dye, dihydroethidium, and CM-H(2)DCFDA. While no significant decrease in saliva secretion was observed after irradiation in the mice that were tr...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Tai Y, Inoue H, Sakurai T, Yamada H, Morito M, Ide F, Mishima K, Saito I Tags: Radiat Res Source Type: journals

Dynamic contrast-enhanced magnetic resonance imaging of tumors: preclinical validation of parametric images.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study shows that DCE-MRI can provide valid quantitative parametric images of the tumor microenvironment in preclinical cancer models and thus supports the suggestion that DCE-MRI may be developed to be a clinically useful method for individualization of microenvironment-based cancer treatment, a possibility that merits increased clinical interest. PMID: 19708783 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Egeland TA, Simonsen TG, Gaustad JV, Gulliksrud K, Ellingsen C, Rofstad EK Tags: Radiat Res Source Type: journals

In Vitro and In Vivo Optimization of an Anti-glioma Modality Based on Synchrotron X-Ray Photoactivation of Platinated Drugs.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract For the past 5 years, a radio-chemotherapy approach based on the photoactivation of platinum atoms (PAT-Plat) consisting of treating tumors with platinated compounds and irradiating them above the platinum K edge (78.4 keV) has been developed at the European Synchrotron Radiation Facility (Grenoble, France). Compared to other preclinical modalities, PAT-Plat provides the highest survivals of rats bearing the rodent F98 glioma. However, further investigations are required to optimize its efficiency and to allow its clinical application. Here we examined in vitro and in vivo whether monochromatic X rays are more...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Biston MC, Joubert A, Charvet AM, Balosso J, Foray N Tags: Radiat Res Source Type: journals

Effects of Head-Only Exposure of Rats to GSM-900 on Blood-Brain Barrier Permeability and Neuronal Degeneration.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Salford et al. reported in 2003 that a single 2-h exposure to GSM-900 mobile telephony signals induced brain damage (increased permeability of the blood-brain barrier and presence of dark neurons) 50 days after exposure. In our study, 16 Fischer 344 rats (14 weeks old) were exposed head-only to the GSM-900 signal for 2 h at various brain-averaged SARs (0, 0.14 and 2.0 W/kg) or were used as cage or positive controls. Albumin leakage and neuron degeneration were evaluated 14 and 50 days after exposure. No apoptotic neurons were found 14 days after the last exposure using the TUNEL method. No statistically signif...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: de Gannes FP, Billaudel B, Taxile M, Haro E, Ruffié G, Lévêque P, Veyret B, Lagroye I Tags: Radiat Res Source Type: journals

Ionizing Radiation and Leukemia Mortality among Japanese Atomic Bomb Survivors, 1950-2000.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract This paper provides the first comprehensive report on mortality by type of leukemia among the Japanese atomic bomb survivors in the Life Span Study (LSS). Analyses include 310 deaths due to leukemia during the period 1950-2000 among 86,611 people in the LSS. Poisson regression methods were used to evaluate associations between estimated bone marrow dose and leukemia mortality. Attention was given to variation in the radiation dose-leukemia mortality association by time since exposure, age at exposure, city and sex. The excess relative rate per gray of acute myeloid leukemia was best described by a quadratic do...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Richardson D, Sugiyama H, Nishi N, Sakata R, Shimizu Y, Grant EJ, Soda M, Hsu WL, Suyama A, Kodama K, Kasagi F Tags: Radiat Res Source Type: journals

Stochastic population dynamic effects for lung cancer progression.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract The multistage paradigm is widely used in quantitative analyses of radiation-influenced carcinogenesis. Steps such as initiation, promotion and transformation have been investigated in detail. However, progression, a later step during which malignant cells produced in the earlier steps can develop into clinical cancer, has received less attention in computational radiobiology; it has often been approximated deterministically as a fixed, comparatively short, lag time. This approach overlooks important mechanisms in progression, including stochastic extinction, possible radiation effects on tumor growth, immune ...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Fakir H, Tan WY, Hlatky L, Hahnfeldt P, Sachs RK Tags: Radiat Res Source Type: journals

Formalization and theoretical analysis of the local effect model.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract The Local Effect Model (LEM) is a track-structure model that was developed to predict the biological response of a cell to irradiation with any ion. Because it needs to be studied both experimentally and theoretically, a mathematical formalization of the LEM based on three main postulates and three secondary approximations is proposed for a more detailed analysis. The general relationship that links cell survival to the mean number of lethal events is deduced. A Monte Carlo simulation is also proposed to calculate the local dose. It is shown that the local dose is highly heterogeneous even for uniform X irradi...
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Beuve M Tags: Radiat Res Source Type: journals

Corrections.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Authors: PMID: 19708789 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - August 29, 2009 Category: Physics Tags: Radiat Res Source Type: journals

Radiation research editors' award.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
PMID: 19708790 [PubMed - in process] (Source: Radiation Research)
Source: Radiation Research - August 29, 2009 Category: Physics Authors: Carlson DJ Tags: Radiat Res Source Type: journals

Rad1, rad10 and rad52 Mutations Reduce the Increase of Microhomology Length during Radiation-Induced Microhomology-Mediated Illegitimate Recombination in Saccharomyces cerevisiae.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Illegitimate recombination can repair DNA double-strand breaks in one of two ways, either without sequence homology or by using a few base pairs of homology at the junctions. The second process is known as microhomology-mediated recombination. Previous studies showed that ionizing radiation and restriction enzymes increase the frequency of microhomology-mediated recombination in trans during rejoining of unirradiated plasmids or during integration of plasmids into the genome. Here we show that radiation-induced microhomology-mediated recombination is reduced by deletion of RAD52, RAD1 and RAD10 but is not affe...
Source: Radiation Research - July 28, 2009 Category: Physics Authors: Chan CY, Schiestl RH Tags: Radiat Res Source Type: journals

Extensive Repair of DNA Double-Strand Breaks in Cells Deficient in the DNA-PK-Dependent Pathway of NHEJ after Exclusion of Heat-Labile Sites.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Double-strand breaks (DSBs) can be generated in the DNA of mammalian cells when heat-labile sites induced by ionizing radiation within a clustered DNA damage site are thermally transformed to single-strand breaks (SSBs) and combine with other SSBs or heat-labile sites in the opposite DNA strand. When this thermal transformation of heat-labile sites to SSBs occurs during DNA preparation using high-temperature lysis, the DSB yield is overestimated by including DSBs not present in the tested cell. Low-temperature lysis avoids this artifact but shows slower repair kinetics for prompt DSBs than high-temperature lys...
Source: Radiation Research - July 28, 2009 Category: Physics Authors: Singh SK, Wu W, Wu W, Wang M, Iliakis G Tags: Radiat Res Source Type: journals

Lack of DNA Polymerase theta (POLQ) Radiosensitizes Bone Marrow Stromal Cells In Vitro and Increases Reticulocyte Micronuclei after Total-Body Irradiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Mammalian POLQ (pol theta) is a specialized DNA polymerase with an unknown function in vivo. Roles have been proposed in chromosome stability, as a backup enzyme in DNA base excision repair, and in somatic hypermutation of immunoglobulin genes. The purified enzyme can bypass AP sites and thymine glycol. Mice defective in POLQ are viable and have been reported to have elevated spontaneous and radiation-induced frequencies of micronuclei in circulating red blood cells. To examine the potential roles of POLQ in hematopoiesis and in responses to oxidative stress responses, including ionizing radiation, bone marrow...
Source: Radiation Research - July 28, 2009 Category: Physics Authors: Goff JP, Shields DS, Seki M, Choi S, Epperly MW, Dixon T, Wang H, Bakkenist CJ, Dertinger SD, Torous DK, Wittschieben J, Wood RD, Greenberger JS Tags: Radiat Res Source Type: journals

Protective effects of dietary antioxidants on proton total-body irradiation-mediated hematopoietic cell and animal survival.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Dietary antioxidants have radioprotective effects after gamma-radiation exposure that limit hematopoietic cell depletion and improve animal survival. The purpose of this study was to determine whether a dietary supplement consisting of l-selenomethionine, vitamin C, vitamin E succinate, alpha-lipoic acid and N-acetyl cysteine could improve survival of mice after proton total-body irradiation (TBI). Antioxidants significantly increased 30-day survival of mice only when given after irradiation at a dose less than the calculated LD(50/30); for these data, the dose-modifying factor (DMF) was 1.6. Pretreatment of a...
Source: Radiation Research - July 28, 2009 Category: Physics Authors: Wambi CO, Sanzari JK, Sayers CM, Nuth M, Zhou Z, Davis J, Finnberg N, Lewis-Wambi JS, Ware JH, El-Deiry WS, Kennedy AR Tags: Radiat Res Source Type: journals

Up-regulation of 8-oxo-dGTPase Activity of MTH1 Protein in the Brain, Testes and Kidneys of Mice Exposed to (137)Cs gamma Radiation.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Abstract Mammalian MTH1 protein is an antimutagenic (2'-deoxy)ribonucleoside 5'-triphosphate pyrophosphohydrolase that prevents the incorporation of oxidatively modified nucleotides into nucleic acids. It decomposes most specifically the miscoding products of oxidative damage to purine nucleic acid precursors (e.g. 8-oxo-dGTP, 2-oxo-dATP, 2-oxo-ATP, 8-oxo-GTP) that may cause point mutations or transcription errors when incorporated into DNA and RNA, respectively. The increased expression of MTH1 mRNA and MTH1 protein was previously proposed as a molecular marker of oxidative stress. Therefore, we hypothesized that incr...
Source: Radiation Research - July 28, 2009 Category: Physics Authors: Bialkowski K, Szpila A, Kasprzak KS Tags: Radiat Res Source Type: journals