Abstract：
:The efficacy of photodynamic therapy is dependent upon the optical dose rate or upon the fractionation schedule on the light. These effects are thought to be limited by the time required for oxygen diffusion from the capillaries, since this therapy can consume oxygen faster than it can be supplied to tissues distant from the blood vessels. Oxygen diffusion and consumption by metabolic and photochemical mechanisms have been modeled here to compare theoretical predictions with experimental results of varying light fractionations and delivered dose rates. The mathematics of the problem have been described in the literature, and the present study extends these calculations to allow a more direct and quantitative comparison with fractionation experiments, using both analytical and numerical arguments. The optimum fraction time was found to depend only on the intercapillary spacing and not on the intensity of irradiation or the concentration of photosensitizer. The calculations indicate that experimentally observed optimum fractionation times of 30 and 60 s correspond to a distance from capillary to cell of approximately 1 mm. These results suggest that the fractionated light irradiation experiments need careful interpretation, and some possible reasons for longer optimum fractionation times are discussed.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Pogue BW,Hasan Tdoi
10.2307/3579621subject
Has Abstractpub_date
1997-05-01 00:00:00pages
551-9issue
5eissn
0033-7587issn
1938-5404journal_volume
147pub_type
杂志文章abstract：:Deep-space travel presents risks of exposure to ionizing radiation composed of a spectrum of low-fluence protons (1H) and high-charge and energy (HZE) iron nuclei (e.g., 56Fe). When exposed to galactic cosmic rays, each cell in the body may be traversed by 1H every 3-4 days and HZE nuclei every 3-4 months. The effects...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14667.1
更新日期：2017-08-01 00:00:00
abstract：:The capacity of plateau-phase Chinese hamster V79 and normal and transformed C3H-10T1/2 cells for repair of potentially lethal radiation damage (PLD) was evaluated for cells irradiated alone or given combined treatments of heat and radiation. The data show that all cell lines tested could repair PLD and that transform...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-01-01 00:00:00
abstract：:The effects of the methylxanthine, caffeine, on heat sensitization was investigated using Chinese hamster ovary (CHO) cells. Caffeine sensitized CHO cells to heat killing by reducing both the shoulder and the slope of the 44 degrees C survival curve. Heating was performed in suspension by addition of cells to preheate...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-09-01 00:00:00
abstract：:Vascular injury after radiation exposure contributes to multiple types of tissue injury through a cascade of events. Some of the earliest consequences of radiation damage include increased vascular permeability and promotion of inflammation, which is partially manifested by increased leukocyte-endothelial (L/E) intera...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14896.1
更新日期：2018-07-01 00:00:00
abstract：:The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq 239Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq 226Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq 228Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq 228Th/kg, and 12 dogs inj...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-06-01 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：:The mutagenic activity of green (532 nm) and infrared (1064 nm) ultra-short laser light pulses was tested in cultured Syrian hamster fibroblasts by a hypoxanthine phosphoribosyl-transferase (HPRT) mutagenesis assay. In 18 irradiation trials, cells were exposed to eight consecutive 100-ps pulses of either 532 nm or 106...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-04-01 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
abstract：:Alteration of the radiation-induced changes in wound contraction, collagen synthesis and wound histology by ascorbic acid was studied in mice exposed to 10, 16 and 20 Gy of fractionated (2 Gy/fraction) gamma radiation. The animals were given double-distilled water or ascorbic acid daily before exposure to 2 Gy/day of ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2003)159[0371:eoteoa]2.0.co;2
更新日期：2003-03-01 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：:The relationship between intracellular and extracellular pH was investigated in a murine tumor and normal tissue, prior to and following glucose injection. Isotransplants of the murine tumor FSa-II in the dorsum of the hind foot and leg muscle, were investigated in nonanesthetized mice. Extracellular pH was measured w...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-05-01 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：:Evaluation of the probability of biological phenomena per cell by colony formation, requires knowledge not only of the number of cells at risk but also of their microdistribution. In the present study, the influence of cellular multiplicity (number of cells per potential colony-forming unit) on the determination of ra...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-06-01 00:00:00
abstract：:The present study was undertaken to standardize a dichlorofluorescein (DCF) assay for measurement of radiation-induced oxidation of dichlorofluorescin (DCFH) substrate in MCF-10 cells. This assay was highly sensitive and capable of detecting increased DCFH oxidation in the cells exposed to gamma radiation at doses as ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3299
更新日期：2005-02-01 00:00:00
abstract：:Domestic radon risk estimates are typically based either on data for uranium miners or on data derived from A-bomb survivors; comparison of domestic radon risk estimates derived from these two disparate sources represents an important test of their reliability. There is currently a significant discrepancy of about a f...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1995-04-01 00:00:00
abstract：:In recent years, there has been increasing concern over the possibility of a radiological or nuclear incident occurring somewhere in the world. Intelligence agencies frequently report that terrorist groups and rogue nations are seeking to obtain radiological or nuclear weapons of mass destruction. In addition, there e...
journal_title：Radiation research
pub_type：
doi：10.1667/RR14810.1
更新日期：2017-08-01 00:00:00
abstract：:Dose-response curves were measured for the formation of direct-type DNA products in X-irradiated d(GCACGCGTGC)(2)prepared as dry films and as crystalline powders. Damage to deoxyribose (dRib) was assessed by HPLC measurements of strand break products containing 3' or 5' terminal phosphate and free base release. Base d...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1058.1
更新日期：2007-09-01 00:00:00
abstract：:Human erythrocytes were isolated from the blood of healthy donors and then incubated in the presence of suspensions of alpha-tocopherol for 30 min at 37 degrees C. Unabsorbed tocopherol was removed by centrifugation using several washes of isotonic phosphate-buffered saline. Washed erythrocytes were resuspended to 0.0...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-08-01 00:00:00
abstract：:Exposure of humans and rodents to radiofrequency (RF) cell phone fields has been reported to alter a number of stress- related parameters. To study this potential relationship in more detail, tube-restrained immobilized Fischer 344 rats were exposed in the near field in a dose-dependent manner to pulse-modulated (11 p...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)155[0584:eoiace]2.0.co;2
更新日期：2001-04-01 00:00:00
abstract：:Human peripheral blood samples collected from three healthy human volunteers were exposed in vitro to pulsed-wave 2450 MHz radiofrequency (RF) radiation for 2 h. The RF radiation was generated with a net forward power of 21 W and transmitted from a standard gain rectangular antenna horn in a vertically downward direct...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2000)153[0479:pddihb]2.0.co;2
更新日期：2000-04-01 00:00:00
abstract：:To estimate the effect of 50 Hz magnetic-field exposure on genome-wide gene expression, the yeast Saccharomyces cerevisiae was used as a model for eukaryotes. 2D PAGE (about 1,000 spots) for protein and cDNA microarray (about 5,900 genes) analysis for mRNA were performed. The cells were exposed to 50 Hz vertical magne...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3006
更新日期：2003-07-01 00:00:00
abstract：:Wortmannin has been shown to be an efficient radiosensitizer. Since wortmannin is able to inhibit DNA-dependent protein kinase (DNA-PK) and double-strand break (DSB) rejoining, it is believed that its mechanism of radiation sensitization is through the inhibition of DNA-PK-mediated repair of DSBs. However, since wortm...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1999-02-01 00:00:00
abstract：:A study has been made of methods for rapidly inactivating cells of E. coli at neutral pH to prevent enzymatic, chemical, or physical modification to DNA damaged by irradiation. The radiation was delivered in a fraction of a second using an electron accelerator. Cell inactivation was with ethanol or a solution (CSE) co...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-11-01 00:00:00
abstract：:As part of a long-term study of the effects of irradiation during development, prenatal and early neonatal mortality were evaluated for beagles exposed in utero at 8 days postcoitus (dpc), 28 dpc, 55 dpc, or 2 days postpartum. Mean doses used were 0,0.16, or 0.83 Gy. A decrease in whelping rates was observed for femal...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-07-01 00:00:00
abstract：:Many studies have demonstrated the effect of oncogene transfection on the radiation sensitivity of primary rat embryo fibroblasts. Our results indicate that transformation by H-ras plus v-myc oncogenes confers radiation resistance to a much greater extent than transformation by either gene alone. We have further shown...
journal_title：Radiation research
pub_type： 杂志文章,评审
doi：
更新日期：1994-04-01 00:00:00
abstract：:Gleevec, a selective tyrosine kinase inhibitor, retarded the growth of anaplastic thyroid cancer cell lines in vitro and in vivo through selective inhibition of ABL tyrosine kinase activity. In the present study, we investigated the ability of Gleevec to modulate the in vitro and in vivo radiation response of anaplast...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3466.1
更新日期：2006-01-01 00:00:00
abstract：:Radiation-induced complications of the respiratory system are a common side effect of thoracic radiotherapy with no viable treatment option. Here, we investigated the potential therapeutic effect of the orphan drug pirfenidone for treating radiation-induced pulmonary fibrosis. C57BL/6 mice received a single fraction o...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15017.1
更新日期：2018-10-01 00:00:00
abstract：:To improve radioimmunotherapy with Auger electron emitters, we assessed whether the biological efficiency of (125)I varied according to its localization. A-431 and SK-OV-3 carcinoma cells were incubated with increasing activities (0-4 MBq/ml) of (125)I-labeled vectors targeting the cell membrane, the cytoplasm or the ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR1359.1
更新日期：2008-08-01 00:00:00
abstract：:We describe a rapid assay to predict intrinsic radiosensitivity of normal tissues based on the radiation-induced cytotoxic response of a number of types of white blood cells. Twenty-four hours after irradiation, leukocytes were prepared for analysis by flow cytometry. Radiation-induced cytotoxicity was characterized b...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-01-01 00:00:00
abstract：:Deep underground laboratories (DULs) were originally created to host particle, astroparticle or nuclear physics experiments requiring a low-background environment with vastly reduced levels of cosmic-ray particle interference. More recently, the range of science projects requiring an underground experiment site has gr...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR15083.1
更新日期：2018-09-01 00:00:00
