Abstract：
:Previous studies showed that a 6-week pretreatment of rats with testosterone plus estradiol enhanced the recovery of spermatogenesis 9 weeks after gamma irradiation, resulting in a dose-modifying factor (DMF) of about 2. To test whether the effect of the hormone treatment was mediated through changes in oxygen tension, thiol levels or DNA repair, we irradiated the testes of rats with neutrons, which depend less on these factors than does low-LET radiation for their cytotoxic action. Control rats and rats treated with testosterone plus estradiol were irradiated with 0.7-2.7 Gy of cyclotron-generated high-energy neutrons. The recovery of spermatogenesis was assessed 9 weeks after irradiation by testis weights, sperm counts and the tubule repopulation indices. Greater recovery of spermatogenesis was observed for all end points, with a DMF of about 2 for rats treated with testosterone plus estradiol compared to the irradiated, cholesterol-treated rats. The equal protection factors for neutrons and gamma rays indicate that oxygen, thiols and repair of DNA damage are unlikely to be involved in the protective effect of the hormone treatment.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Wilson G,Kangasniemi M,Meistrich MLsubject
Has Abstractpub_date
1999-07-01 00:00:00pages
51-6issue
1eissn
0033-7587issn
1938-5404journal_volume
152pub_type
杂志文章abstract：:In the analysis of the effects of radiation or drugs on clonogenic survival data of mammalian cells, it is often advantageous to compare entire dose-response curves generated under different experimental conditions rather than to conduct single-dose comparisons. We propose a two-stage method for the global comparison ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-08-01 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：:Beagle dogs had signs of restrictive lung disease 1 to 5 years after exposure by inhalation to 239PuO2 aerosols. The 239PuO2 aerosols were monodisperse with activity median aerodynamic diameters of 0.75, 1.5, or 3.0 microns. The plutonium particles produced protracted alpha irradiation of the lungs. Ten dogs had speci...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-08-01 00:00:00
abstract：:The potential for radiogenic neoplasia from charged-particle irradiation has been estimated using the Harderian gland of the mouse as a test system. Particles ranging in Z from Z = 1 (proton) to Z = 41 (niobium), in energy from 228 to 670A MeV, and in LET from 0.4 to 464 keV/microns were produced at the Lawrence Berke...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-12-01 00:00:00
abstract：:The distribution and kinetics of proximal tubular cells with abnormally large nuclei, which were observed in irradiated mouse kidneys before any other obvious histological effects, were investigated. Six months after the administration of 13 or 15 Gy, little histopathological change was noted, in the kidneys of C3H mi...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-07-01 00:00:00
abstract：:Experimental measurements of the radial restricted linear energy transfer (LETr) for alpha beams of 18.3 MeV/n in tissue-equivalent gas were presented. The radial dose distribution for the alpha beam was deduced from the restricted LET measurements. A differential W value for the alpha particle in the tissue-equivalen...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-12-01 00:00:00
abstract：:We examined the effects of X irradiation on activation of the promoter of the human HSP70B gene, which is activated only after heat shock. The HSP70B promoter was ligated to the bacterial beta-galactosidase (beta-gal) gene, and the reporter plasmid was transfected into NCI-H1299 carcinoma cells. The expression of the ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1998-02-01 00:00:00
abstract：:To determine whether different agents that enhance the expression of potentially lethal X-ray damage (PLD) interact with the same or different lesions (or spectrum of lesions), cell killing was measured in three kinds of experiments: (1) When cells were irradiated in G1 phase and treated with caffeine or hydroxyurea a...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-11-01 00:00:00
abstract：:On future missions into deep space, astronauts will be required to work more autonomously than on previous missions, and thus their ability to perform executive functions could be critical to mission success. In this study, we determined the effect that ≤15 cGy of 600 MeV/n 56Fe particles has on attentional set-shifti...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15085.1
更新日期：2018-12-01 00:00:00
abstract：:We have used Escherichia coli B/r to test the proposal that hydroxyl radicals (.OH) are major contributors to lethal damage when bacteria in equilibrium with air or 100% nitrogen are exposed to ionizing radiation. In addition, we have tested the hypothesis that oxygen sensitizes bacterial cells to radiation by reactin...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-02-01 00:00:00
abstract：:A recent publication by Leith et al. (Cancer Res. 51, 4111-4113, 1991) showed that administration of epidermal growth factor (EGF) (0.25 mg/kg; q.i.d. x 7) to mice bearing xenografted A431 human epidermoid cancers produced increased tumor growth and a reduction of the percentage of hypoxic cells within neoplasms. In c...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1992-11-01 00:00:00
abstract：:Cells that have been grown as multicell tumor spheroids exhibit radioresistance compared to the same cells grown in monolayers. Comparison of potentially lethal damage (PLD) repair and its kinetics was made between 9L cells grown as spheroids and confluent monolayers. Survival curves of cells plated immediately after ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-06-01 00:00:00
abstract：:While lifespan studies provide basic information for estimating the risk of ionizing radiation, findings on the effect of low-dose/low-dose-rate irradiation on the lifespan of mammals are controversial. Here we evaluate the effect of continuous exposure to low-dose-rate γ radiation on the lifespan of mice with acceler...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR2977.1
更新日期：2013-06-01 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：:Carcinogenesis is a multistep process, involving the irreversible conversion of a stem cell to a terminal-differentiation-resistant cell ("initiation"), followed by the clonal expansion of this cell ("promotion") and by the acquisition of other genetic alterations leading to malignancy ("progression"). The initiation ...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：
更新日期：1990-09-01 00:00:00
abstract：:Mutation and killing induced by X radiation and 60CO gamma radiation were studied in six different histidine-requiring auxotrophs of Salmonella typhimurium. Strain TA100, which is sensitive to base-pair substitutions, and strains TA2637 and TA98, which are sensitive to frameshifts, carry the pKM101 plasmid and exhibit...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1984-11-01 00:00:00
abstract：:We have studied the effect on sister chromatid exchange (SCE) induction in 9L rat brain tumor cells caused by combination treatment with BCNU and X rays. Over the dose and concentration ranges used in these experiments, BCNU induced relatively large numbers of SCEs, while X rays induced few SCEs. When cells were X irr...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1984-01-01 00:00:00
abstract：:Human keratinocytes show a bystander effect when exposed to low doses of low-LET radiation. In this paper, data are presented showing a method of correcting the overall survival curve to enable analysis of the relative contributions of the bystander effect and the effect attributable to direct interaction of the radia...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2000)153[0508:rcobat]2.0.co;2
更新日期：2000-05-01 00:00:00
abstract：:The correlation between the protein content of nuclei and heat-induced cell killing was determined for HeLa cells with various levels of thermotolerance. Thermotolerance was induced by heating cells at 45 degrees C for 15 or 30 min and then incubating them at 37 degrees C for 5 or 24 h. This procedure resulted in four...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：:The LD50 of 46 salts of metals and rare earths (lanthanoids) was determined in mice. Half the LD50 of the compounds was then combined with lethal radiation (10.5 Gy) and the modification of survival time was scored. Only the metals beryllium and indium and the rare earths cerium, lanthanum and scandium displayed activ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-03-01 00:00:00
abstract：:Clustered DNA damage is considered an important factor in determining the biological consequences of ionizing radiation. In this study, we successfully estimated the localization of abasic sites (APs) in DNA exposed to ionizing radiation using fluorescence resonance energy transfer (FRET) without any involvement of re...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR13780.1
更新日期：2015-01-01 00:00:00
abstract：:The mortality experience between 1956 and 1985 of 8977 males employed by Atomic Energy of Canada Limited is reported. A total of 4260 men, 47% of the cohort, were exposed to low doses of external ionizing radiation at low dose rates, with a mean cumulative equivalent dose of 52.1 mSv. For cancers as a whole the excess...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-03-01 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：:Dose-spread kernels can be used to calculate the dose distribution in a photon beam by convolving the kernel with the primary fluence distribution. The theoretical relationships between various types and components of dose-spread kernels relative to photon attenuation coefficients are explored. These relations can be ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-02-01 00:00:00
abstract：:The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting con...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-04-01 00:00:00
abstract：:The purpose of this study was to develop a rat orthotopic lung tumor model with a solitary intrapulmonary nodule to study the effects of high-dose radiation. A549-Luc non-small cell lung cancer (NSCLC) cells were implanted into nude rats in the intercostal space between ribs 5 and 6 of the right lung. Bioluminescence ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR2157.1
更新日期：2010-07-01 00:00:00
abstract：:The aim of this study was to test the efficacy of captopril, an angiotensin-converting enzyme inhibitor and a known suppressor of fibrosis, in preventing late radiation-induced cardiac pathology. Myocardial functional, histochemical and ultrastructural-morphometric studies were done on perfused hearts of rats isolated...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1993-02-01 00:00:00
abstract：:Previously, we described the radiation-induced (RI) 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) effect as the increased MTT metabolization at the intermediate dose region after the irradiation of an MCF-7/6 cell monolayer with an X-ray dose gradient. We wondered if the cell monolayer at the inte...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3070.1
更新日期：2013-04-01 00:00:00
abstract：:We have assessed the effects of two radiomodifying conditions, glutathione (GSH) depletion and hypoxia, on the formation and repair of radiation-induced chromatin damage, specifically DNA-protein cross-links (DPC). As measured by a nitrocellulose filter-binding assay, untreated V79 cells contain a low level of DPC (1-...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-10-01 00:00:00
abstract：:C57BL/6J male mice were inoculated with 5 X 10(5) B16a melanoma cells. Seven days post-inoculation, when the tumor had grown to 8.0-10.0 mm in diameter, 120 tumor-bearing mice were randomly divided into three groups: (1) sham-irradiated controls, (2) mice receiving 200 cGy five times a week for 6 weeks, and (3) mice r...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-05-01 00:00:00
