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 degrees C for 2 h decreased pHi of SCK cells by 0.15-0.20 pH units, as measured fluorometrically using the pH-sensitive dye BCECF. When the cells were treated with 0.5 mM amiloride at 37 degrees C, the pHi declined by 0.10-0.15 pH units at an extracellular pH (pHe) of both 7.2 and 6.6. Amiloride at 0.5 mM enhanced the thermal damage to SCK cells at pHe 6.6 but not at pHe 7.2. DIDS alone at 0.1 mM exerted no effect on pHi or cellular thermosensitivity. DIDS, however, enhanced the effects of amiloride in decreasing pHi and in increasing the thermoresponse of SCK cells, particularly at pHe 6.6. Treatment of the cells with nigericin at 0.1-1.0 micrograms/ml lowered the pHi and enhanced the thermosensitivity of the cells in a dose-dependent manner. Reductions in pHi and increases in thermosensitivity by nigericin at the lower concentration at pHe 6.6 were far greater than at pHe 7.2. When a mixture of 1.0 micrograms/ml nigericin, 0.5 mM amiloride, and 0.1 mM DIDS was present in the medium, the pHi rapidly decreased by about 0.3 and 0.4 pH units at pHe 7.2 and 6.6, respectively. This drug combination was also extremely effective in sensitizing SCK cells to heat, particularly at pHe 6.6. The fact that the thermosensitization by these drugs at pHe 6.6 is more pronounced than at pHe 7.2 and that intratumor environments are known to be acidic strongly suggested that it may then be possible to enhance the thermal damage with such drugs preferentially in tumors relative to normal tissues.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Lyons JC,Kim GE,Song CWsubject
Has Abstractpub_date
1992-01-01 00:00:00pages
79-87issue
1eissn
0033-7587issn
1938-5404journal_volume
129pub_type
杂志文章abstract::Human T lymphocytes can be used to determine the frequency and molecular spectrum of somatic cell gene mutations induced by ionizing radiations both in vivo and in vitro. In vitro exposure of these G0 cells to low-LET 137Cs gamma rays results in the induction of HPRT mutations and a predominant molecular spectrum of D...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
abstract::We studied heat-induced apoptosis and loss of clonogenicity in Rat-1 fibroblasts, thermotolerant Rat-1 (TT Rat-1), Rat-1 transfected with the human hsp-70 gene (M21) and Rat-1 transfected with the human c-myc proto-oncogene (Rat-1:myc). Relative to Rat-1, TT Rat-1 and M21 cells are heat-resistant, but Rat-1:myc cells ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1996-03-01 00:00:00
abstract::A standard Fricke dosimeter was used to measure the absorbed dose via the oxidation yields of Fe3+ ions in an aqueous environment induced by soft X rays within the "water window" spectral range. We also exploited the property of a neutral solution containing terephthalic acid as a tool for selective detection of OH ra...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15520.1
更新日期:2020-04-01 00:00:00
abstract::Two very different techniques for measuring the energy of neutrons in the energy range 0.1-10 MeV are presented and compared. A recoil-proton spectrometer is used to determine the energy spectra of neutrons produced by the d(4)-Be and p(4)-Be reactions down to the low-energy threshold of 0.7 MeV. The same radiation fi...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::There has been ongoing debate and discussion concerning whether the funding source influenced the outcome of research on human health effects from exposure to radiofrequency fields (RF, electromagnetic waves that carry energy as they propagate in air and dense media). In a study of 225 publications, in which we sought...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15364.1
更新日期:2019-10-01 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::In this study, we sought to determine how diffusion-weighted imaging (DWI) and proton magnetic resonance spectroscopy (1H-MRS) features are associated with histopathological results, and explored the cellular mechanisms of DWI and 1H-MRS in early radiosensitivity of transplanted liver tumors. VX2 tumors were implanted...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15140.1
更新日期:2019-01-01 00:00:00
abstract::It has been acknowledged for many years that radiation exposure induces delayed, non-targeted effects in the progeny of the irradiated cell. Evidence is beginning to demonstrate that among these delayed effects of radiation are epigenetic aberrations, including altered DNA methylation. To test the hypothesis that diff...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR2390.1
更新日期:2011-05-01 00:00:00
abstract::If the limited life span of hematopoietic tissues in vitro is due to a finite proliferative capacity of individual stem cells, one might expect tissues of young donors to possess a greater proliferative capacity and to contain a larger population of primitive stem cells than those of older donors. To test this hypothe...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1987-10-01 00:00:00
abstract::After a planned or unplanned radiation exposure, determination of absorbed dose has great clinical importance, informing treatment and triage decisions in the exposed individuals. Biodosimetry approaches allow for determination of dose in the absence of physical measurement apparatus. The current state-of-the-art biod...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15283.1
更新日期:2019-05-01 00:00:00
abstract::The effect of both hyperthermia and verapamil on cytotoxicity and transport of melphalan was studied in a pleiotropic drug-resistant Chinese hamster ovary cell line (CHRC5) and in the drug-sensitive parent line (AuxB1). The CHRC5 cell line was selected for resistance to colchicine but is also cross-resistant to other ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1995-07-01 00:00:00
abstract::Proteinase-activated receptor 2 (Par2, F2rl1, also designated PAR-2 or PAR2) is prominently expressed in the intestine and has been suggested as a mediator of inflammatory, mitogenic and fibrogenic responses to injury. Mast cell proteinases and pancreatic trypsin, both of which have been shown to affect the intestinal...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3080
更新日期:2003-11-01 00:00:00
abstract::This review was initiated in response to concerns that ionizing radiation could be a cause of melanoma. Studies presenting the relative risks for melanoma after external ionizing radiation exposure were in seven categories: (1) The Canadian Radiation Dose Registry, (2) nuclear industry workers, (3) subjects near nucle...
journal_title:Radiation research
pub_type: 杂志文章,评审
doi:10.1667/rr3447.1
更新日期:2005-11-01 00:00:00
abstract::Chinese hamster V79 cells grown for several hours in suspension culture form spheroids which are more resistant to killing by ionizing radiation than cells grown on petri dishes, a phenomenon known as the "contact effect." Previous results using the alkali-unwinding assay as a measure of DNA damage have implicated dif...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-01-01 00:00:00
abstract::The appearance of prostaglandins and thromboxane in mouse serum after X irradiation was observed by simultaneous quantitative analysis using gas chromatography/mass spectrometry/selected ion monitoring with stable isotope dilution methods. Mice of two strains (C57BL/CN Jcl and BALB/c) showed similar responses to X irr...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1998-01-01 00:00:00
abstract::Evaluation of the characteristics of accelerator-based thermal neutron fields is recognized as an important issue when discussing the effectiveness of boron neutron capture therapy (BNCT). In this study, we propose that the radiation chemical yield (G value) of hydroxyl radicals (Goh•) can be considered a universal pa...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15318.1
更新日期:2019-05-01 00:00:00
abstract::Radiation of the esophagus of C3H/HeNsd mice with 35 or 37 Gy of 6 MV X rays induces significantly increased RNA transcription for interleukin 1 (Il1), tumor necrosis factor alpha (Tnf), interferon gamma inducing factor (Ifngr), and interferon gamma (Ifng). These elevations are associated with DNA damage that is detec...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)155[0002:morice]2.0.co;2
更新日期:2001-01-01 00:00:00
abstract::Radiation is an independent risk factor for cardiovascular and cerebrovascular disease in cancer patients. Modern radiotherapy techniques reduce the volume of the heart and major coronary vessels exposed to high doses, but some exposure is often unavoidable. Radiation damage to the myocardium is caused primarily by in...
journal_title:Radiation research
pub_type: 杂志文章,评审
doi:10.1667/RR1862.1
更新日期:2010-12-01 00:00:00
abstract::The induction of chromosome aberrations in human lymphocytes irradiated in vitro with X rays generated at a tube voltage of 29 kV was examined to assess the maximum low-dose RBE (RBE(M)) relative to higher-energy X rays or 60Co gamma rays. Since blood was taken from the same male donor whose blood had been used for pr...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2002)158[0771:teokxr]2.0.co;2
更新日期:2002-12-01 00:00:00
abstract::Microwave radiation produces hyperthermia. The mammalian thermoregulatory system defends against changes in temperature by mobilizing diverse control mechanisms. Neurotransmitters play a major role in eliciting thermoregulatory responses. The involvement of adrenergic and muscarinic cholinergic receptors was investiga...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1987-01-01 00:00:00
abstract::Several studies over recent years have highlighted the possibility that radiation can induce transmissible genomic instability. Most of these involve in vitro irradiation and usually in vitro culture. Here it is reported that the short-half-life bone-seeking alpha-particle emitter (224)Ra did not induce excess transmi...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)155[0345:lodtci]2.0.co;2
更新日期:2001-02-01 00:00:00
abstract::Current lung cancer risk estimates after exposure to low-linear energy transfer radiation such as X rays are based on studies of people exposed to such radiation at high dose rates, for example the atomic bomb survivors. Radiobiology and animal experiments suggest that risks from exposure at low to moderate dose rates...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1995-06-01 00:00:00
abstract::Phosphorylated ATM immunofluorescence staining was used to investigate the dose-response relationship for the number of DNA double-strand breaks (DSBs) induced in primary normal human fibroblasts irradiated with doses from 1.2 to 200 mGy. The induction of DSBs showed a supralinear dose-response relationship. Radiation...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1255.1
更新日期:2008-09-01 00:00:00
abstract::A statistical technique is given which can be used to estimate the parameters of the two-component model for cell survival from quantal response multifraction data. The method is a nonlinear logistic regression and relies on a mild assumption relating the probability of death to cell survival level. The method is demo...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1985-12-01 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::While the link between risk of leukemia and acute radiation exposure is well established for large doses received acutely, uncertainty remains around the translation of these risk estimates to occupational exposure scenarios where the doses are low and accumulated over time, possibly over many years. We present leukem...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15358.1
更新日期:2019-11-01 00:00:00
abstract::Although tissue mast cells are derived from the bone marrow, some descendants of bone marrow-derived precursors retain the ability to proliferate and differentiate into mast cells even after localization in the skin. The purpose of the present study was to determine the D0 values for mast-cell precursors in the bone m...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
abstract::Mice were irradiated with 1 Gy of fission neutrons. At intervals up to 15 days after irradiation undifferentiated spermatogonia were counted in whole mounts of seminiferous tubules in up to eight stages of the epithelial cycle. From Day 6 onward lower numbers of spermatogonia were found in the areas which were in stag...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1984-03-01 00:00:00
abstract::This study was designed to determine whether patients taking angiotensin-converting enzyme (ACE) inhibitors while receiving radiation therapy for lung cancer are protected from developing symptomatic radiation pneumonitis. The records of 213 eligible patients receiving thoracic irradiation for lung cancer with curativ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2000)153[0405:caceip]2.0.co;2
更新日期:2000-04-01 00:00:00
abstract::Dose-response relationships observed in laboratory animals can be used to identify possible human risk factors and may also be used in a quantitative manner when human data are not available. This paper presents an analysis of the dose dependency of osteosarcoma incidence in beagle dogs given a single inhalation expos...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1992-10-01 00:00:00