Abstract：
:The lactose operon functions under the control of the repressor-operator system. Binding of the repressor to the operator prevents the expression of the structural genes. This interaction can be destroyed by the binding of an inducer to the repressor. If ionizing radiations damage the partners, a dramatic dysfunction of the regulation system may be expected. We showed previously that gamma irradiation hinders repressor-operator binding through protein damage. Here we show that irradiation of the repressor abolishes the binding of the gratuitous inducer isopropyl-1-beta-D-thiogalactoside (IPTG) to the repressor. The observed lack of release of the repressor from the complex results from the loss of the ability of the inducer to bind to the repressor due to the destruction of the IPTG binding site. Fluorescence measurements show that both tryptophan residues located in or near the IPTG binding site are damaged. Since tryptophan damage is strongly correlated with the loss of IPTG binding ability, we conclude that it plays a critical role in the effect. A model was built that takes into account the kinetic analysis of damage production and the observed protection of its binding site by IPTG. This model satisfactorily accounts for the experimental results and allows us to understand the radiation-induced effects.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Gillard N,Spotheim-Maurizot M,Charlier Mdoi
10.1667/rr3336subject
Has Abstractpub_date
2005-04-01 00:00:00pages
433-46issue
4eissn
0033-7587issn
1938-5404pii
RR3336journal_volume
163pub_type
杂志文章abstract：:Alteration of adhesion molecule expression on endothelial cells has a direct connection with ionizing radiation-induced atherosclerosis, which is an adverse effect observed after radiotherapy. However, minimal attention has been given to monocytes/macrophages role in atherosclerosis development, which are exposed to t...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3119.1
更新日期：2013-01-01 00:00:00
abstract：:This laboratory previously demonstrated that hyperbaric oxygen and hyperbaric carbogen improved oxygenation in the R3230Ac tumor, but normobaric 100% O2 and carbogen did not. The current study assessed tumor growth after exposure to radiation plus either hyperbaric oxygen, carbogen or carbogen/nicotinamide and the rel...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-06-01 00:00:00
abstract：:The immunocytochemical response to DNA damage induced by low-energy bismuth and carbon ions was investigated in normal human fibroblasts. Inside the nuclei, the traversing charged particles lead to the accumulation of proteins related to DNA lesions and repair along the ion trajectories. Irradiation under a standard g...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2003)159[0676:biohct]2.0.co;2
更新日期：2003-05-01 00:00:00
abstract：:Mathematical analysis of cell survival allows parameter estimation for radiobiological models and selection of an appropriate model. To our knowledge, no rigorous comparisons on the accuracy of various methods used for such analysis have been performed. In this study we compared three methods: 1. maximization of binom...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14195.1
更新日期：2016-03-01 00:00:00
abstract：:Previous studies identified radiation therapy as a key modifier of basal cell carcinoma (BCC) risk in survivors of hematopoietic cell transplantation (HCT). In the present analysis, risk of BCC was analyzed in relation to age at transplant, attained age, race, total-body irradiation (TBI), and radiation fractionation ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1469.1
更新日期：2009-02-01 00:00:00
abstract：:The molecular structure of mutants induced in human lymphoblast cells by 500 cGy X rays in the presence of the radioprotector cysteamine (25 mM) has been compared with that induced by an equally mutagenic treatment of 150 cGy X rays alone. Sets of mutants at the hypoxanthine-guanine phosphoribosyl transferase locus we...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-05-01 00:00:00
abstract：:An understanding of proton radiobiology is critical for optimization of both proton radiotherapy and assessment of carcinogenesis risk from space radiation. Although the physical aspects of proton beam radiobiology is well understood, the biological aspects, particularly the complex biological end points, have been un...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：10.1667/RR2839.1
更新日期：2013-03-01 00:00:00
abstract：:A standardized dichlorofluorescin (DCF) fluorometric assay capable of measuring radiation-induced oxidative stress was used to determine the effectiveness of protons and high-mass, high-atomic number (Z) and high-energy (HZE) particles to produce oxidative stress in vitro. Protons were found to be about equally as eff...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2005)163[0364:doosib]2.0.co;2
更新日期：2005-04-01 00:00:00
abstract：:Cataract is one of the major morbidities in the U.S. population and it has long been appreciated that high and acutely delivered radiation doses of 1 Gy or more can induce cataract. Some more recent studies, in particular those of the U.S. Radiologic Technologists, have suggested that cataract may be induced by much l...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15529.1
更新日期：2020-08-01 00:00:00
abstract：:The effects of amiloride (an inhibitor of Na+/H+ antiport), DIDS (an inhibitor of Na(+)-coupled and Na(+)-independent HCO3-/Cl- exchange) and nigericin (K+/H+ ionophore) alone and in various combinations on the intracellular pH (pHi) and thermosensitivity of SCK tumor cells were studied. Hyperthermia alone at 43 degre...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-01-01 00:00:00
abstract：:Most plutonium-induced bone tumors in beagles arise in trabecular bone sites surrounded by hematopoietic tissue. The microvasculature and the relative incorporation of 241Pu (a low energy beta emitter) on trabecular bone surfaces from red and fatty marrow sites were studied in the adult beagle. The vascular volume, as...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1984-08-01 00:00:00
abstract：:Numerous studies have shown that histone deacetylase inhibitors (HDACis) improve cellular acetylation while also enhancing the radiation sensitivity. In this work, however, we confirmed that low-dose trichostatin A (TSA) as a typical HDACi could reduce rather than increase the radiosensitivity of cancer cells, while t...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RADE-20-00145.1
更新日期：2021-01-29 00:00:00
abstract：:This study was designed to determine changes in cell numbers, proliferation (using Ki-67) and EGFR expression in mouse bladder urothelium during the early and late radiation response. Groups of mice were irradiated with a single dose of 20 Gy and assayed 0-360 days later. Urothelial cells were counted. After immunohis...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1759.1
更新日期：2010-04-01 00:00:00
abstract：:Three somatic mutation assays were evaluated in men exposed to low-dose, whole-body, ionizing radiation. Blood samples were obtained between 1992 and 1999 from 625 Russian Chernobyl cleanup workers and 182 Russian controls. The assays were chromosome translocations in lymphocytes detected by FISH, hypoxanthine phospho...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2002)158[0424:tsgbac]2.0.co;2
更新日期：2002-10-01 00:00:00
abstract：:The concentrations of uranium isotopes and their decay products 226Ra, 222Rn, 210Pb and 210po have been analyzed in the mineral spring waters of a highly radioactive region of Brazil: Aguas da Prata. This region is located in the Poços de Caldas Plateau, one of the largest weathered alkaline intrusions in the world. D...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1998-08-01 00:00:00
abstract：:The A31-11 mouse BALB/3T3 cell system was adapted for the study of malignant transformation induced by 5.3 MeV alpha particles from a specially constructed 238Pu source. The biologic effects were compared to those of 220 kVp X rays. The alpha-radiation survival curve showed a D0 of 70 rad and a relative biological eff...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-11-01 00:00:00
abstract：:Our goal was to determine whether esophageal progenitor cells could be isolated from adult mouse esophagus or bone marrow and shown to home to and proliferate in the irradiated esophagus of recipient mice. Esophageal progenitor cells were isolated from adult male C3H/HeNsd or C57BL/6J green fluorescent protein (GFP(+)...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3224
更新日期：2004-09-01 00:00:00
abstract：:The present paper describes experiments conducted over the last several years which have focused primarily on the development of mammary tumors in BALB/c mice after neutron and gamma irradiation. Time-dose relationships for induction of mammary and lung tumors following irradiation with fission-spectrum neutrons and 1...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-10-01 00:00:00
abstract：:The concept of curvature in dose-response relationships figures prominently in radiation biology, encompassing a wide range of interests including radiation protection, radiotherapy and fundamental models of radiation action. In this context, the ability to detect even small amounts of curvature becomes important. Sta...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14520.1
更新日期：2017-01-01 00:00:00
abstract：:While impairment of thyroid function has been demonstrated for high-dose external radiation (e.g., for Hodgkin's disease), the long-term functional effects of low-dose external radiation have not been fully explored. One hundred fifty-three subjects with a past history of thymic irradiation during infancy were stratif...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-06-01 00:00:00
abstract：:The success of boron neutron capture therapy (BNCT) mainly depends on the boron concentration in the tumor and a high tumor/normal tissue (T/N) boron ratio or a high tumor/blood (T/B) boron ratio. Therefore, the effective enhancement of boron ratios is the first priority. Our study investigated whether a low-dose of γ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RADE-20-00102.1
更新日期：2021-01-29 00:00:00
abstract：:Braun, R. D., Lanzen, J. L., Turnage, J. A., Rosner, G. and Dewhirst, M. W. Effects of the Interaction between Carbogen and Nicotinamide on R3230 Ac Tumor Blood Flow in Fischer 344 Rats. Radiat. Res. 155, 724-733 (2001). The purpose of this study was to determine whether there are interactions between carbogen breathi...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)155[0724:eotibc]2.0.co;2
更新日期：2001-05-01 00:00:00
abstract：:1-(2-Fluoro-4-iodo-2,4-dideoxy-beta-L-xylopyranosyl)-2-nitroimidazole (FIAZP) has been synthesized and labeled with radioiodine (125I). Radioiodinated FIAZP is one of a series of sugar-coupled 2-nitroimidazoles developed in our laboratory as probes for noninvasive scintigraphic assessment of tumor hypoxia. An in vivo ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-12-01 00:00:00
abstract：:Energy deposition clusters in the nanometer scale have been investigated systematically in electron, proton, and alpha-particle tracks. The mean absolute frequency distributions of ionization clusters in nanometer sites have been computed. For locally multiply damaged sites and especially for double-strand breaks, the...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-06-01 00:00:00
abstract：:To compare the effects of exposure to a near-resonant frequency of microwaves at two orientations with a higher frequency exposure, five rhesus monkeys were exposed for 4 hr to 225 MHz, electric field oriented parallel to the long axis of the body (225 MHz-E), and to 225 MHz, magnetic field orientation (225 MHz-H), or...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:Clinicians involved in conventional radiation therapy are very concerned about the dose-response relationships of normal tissues. Before proceeding to new clinical protocols, radiation biologists involved with conformal proton therapy believe it is necessary to quantify the dose response and tolerance of the organs an...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/r3016
更新日期：2003-07-01 00:00:00
abstract：:We studied the role of cysteine as an intracellular radiation protector under conditions in which both oxygen and thiols were monitored at 37 degrees C. In HCT-116 human colon cancer cells, the intracellular cysteine content affects the radiation survival dramatically at intermediate oxygen levels, but not at zero or ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)156[0388:tkmfro]2.0.co;2
更新日期：2001-10-01 00:00:00
abstract：:The use of tritium-labeled thymidine (3H-TdR) in biological research made it necessary to develop a quick and accurate method for determination of tritium activity in tissue. After 3H-TdR incorporation into the root tip meristem of Vicia faba, total 3H activity as well as 3H-DNA activity was measured by liquid scintil...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1968-12-01 00:00:00
abstract：:We have tested an 836.55 MHz field with North American Digital Cellular (NADC) modulation in a 2-year animal bioassay that included fetal exposure. In offspring of pregnant Fischer 344 rats, we tested both spontaneous tumorigenicity and the incidence of induced central nervous system (CNS) tumors after a single dose o...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1999-09-01 00:00:00
abstract：:The present study, the ninth in a series that began in 1961, extends the time of surveillance 3 more years and covers the period 1950-1985. It is based on the recently revised doses, termed the DS86. The impact of the change from the T65D to the DS86 on the dose-response relationships for cancer mortality was describe...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-02-01 00:00:00
