All issues
Volume 51 (2010)
- Issue 6 Pages 627-
- Issue 5 Pages 493-
- Issue 4 Pages 355-
- Issue 3 Pages 223-
- Issue 2 Pages 97-
- Issue 1 Pages 1-
Volume 51, Issue 2
Displaying 1-15 of 15 articles from this issue
- |<
- <
- 1
- >
- >|
Reviews
-
Koichi CHIDA, Mamoru KATO, Yutaka KAGAYA, Masayuki ZUGUCHI, Haruo SAIT ...2010 Volume 51 Issue 2 Pages 97-105
Published: 2010
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSAlthough the wide acceptance of interventional radiology (IVR) procedures has led to increasing numbers of interventions being performed, the radiation doses from IVR are higher. Increasing numbers of case reports of patient radiation injury resulting from IVR are being published. Therefore, radiation protection during IVR poses a very important problem. To protect against radiation injury, the evaluation of radiation dose is essential. The radiation dose must be evaluated for each IVR x-ray machine and each laboratory, because it varies greatly. To obtain this information easily, and to ensure practical use of the radiation information, good relationships between interventionists and medical physicists are essential.View full abstractDownload PDF (617K) -
Tetsuya SAKASHITA, Takako TAKANAMI, Sumino YANASE, Nobuyuki HAMADA, Mi ...2010 Volume 51 Issue 2 Pages 107-121
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: March 06, 2010JOURNAL FREE ACCESSThe study of radiation effect in Caenorhabditis (C.) elegans has been carried out over three decades and now allow for understanding at the molecular, cellular and individual levels. This review describes the current knowledge of the biological effects of ionizing irradiation with a scope of the germ line, aging and behavior. In germ cells, ionizing radiation induces apoptosis, cell cycle arrest and DNA repair. Lots of molecules involved in these responses and functions have been identified in C. elegans, which are highly conserved throughout eukaryotes. Radiosensitivity and the effect of heavy-ion microbeam irradiation on germ cells with relationship between initiation of meiotic recombination and DNA lesions are discussed. In addition to DNA damage, ionizing radiation produces free radicals, and the free radical theory is the most popular aging theory. A first signal transduction pathway of aging has been discovered in C. elegans, and radiation-induced metabolic oxidative stress is recently noted for an inducible factor of hormetic response and genetic instability. The hormetic response in C. elegans exposed to oxidative stress is discussed with genetic pathways of aging. Moreover, C. elegans is well known as a model organism for behavior. The recent work reported the radiation effects via specific neurons on learning behavior, and radiation and hydrogen peroxide affect the locomotory rate similarly. These findings are discussed in relation to the evidence obtained with other organisms. Altogether, C. elegans may be a good "in vivo" model system in the field of radiation biology.View full abstractDownload PDF (1135K)
Regular Papers
-
Hashem MIRI HAKIMABAD, Lalle RAFAT MOTAVALLI2010 Volume 51 Issue 2 Pages 123-130
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: March 03, 2010JOURNAL FREE ACCESSThe preliminary design studies for developing a prompt-γ rays in vivo neutron activation analysis facility are in construction at Neutron Activation Research Centre of Ferdowsi University of Mashhad. In this work, activation rate distribution is studied in different bilateral configurations in order to reduce the CV of activation rate distribution throughout the body to less than 10%. It means that the maximum RMS deviation from the mean value of distribution must be smaller than 0.5%. The best case includes two pairs of 241Am-Be neutron sources. Each pair (with 70 cm distance between two sources) is positioned within up and down 40 × 110 cm2 area graphite collimators. Also, four moderator/reflector objects are added to transversal body surfaces with 5 cm thick water and 3 cm thick graphite. The proper thickness of polyethylene pre-moderators is chosen 8 mm. The RMS deviation of distribution is 0.3% with the mean activation rate of 1.85 × 10–6 cm–3.View full abstractDownload PDF (666K) -
Hideyuki HARADA, Hirohisa KATAGIRI, Minoru KAMATA, Yasuo YOSHIOKA, Hir ...2010 Volume 51 Issue 2 Pages 131-136
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: November 23, 2009JOURNAL FREE ACCESSWe evaluated the radiological response and clinical outcome in patients with femoral bone metastases after radiotherapy. 102 consecutive patients with femoral metastases without pathological fracture were treated by surgery or radiotherapy between 2002 and 2005. Twelve of them initially treated with surgery were excluded from this study. The remaining 90 patients with 102 lesions underwent radiation therapy as the initial treatment. Twelve patients who died within 30 days by disease progression and 6 who were lost to follow-up were excluded. The remaining 72 patients with 84 lesions including 43 impending fractures were enrolled in this analysis. Radiological changes were categorized into complete response, partial response, no change, and progressive disease based on plain radiograph findings. Pain relief was reviewed for 77 painful lesions. The median radiation dose was 30 Gy. No re-irradiation was performed. 35 lesions (42%) achieved radiological responses median 3 months after radiotherapy. Pain relief was obtained in 36 of 77 lesions (47%). There was no significant correlation between radiological response and pain relief (P = 0.166). Eleven lesions eventually required surgery and considered as treatment failure. The treatment failure rate in the radiological progressive disease (PD) group (8/19, 42%) was significantly higher than that in the non-PD group (3/65, 5%) (P < 0.001). Among 43 impending fracture lesions, 15 lesions (36%) experienced radiological response and 35 lesions (81%) required no surgical interventions. Our data suggest that radiotherapy can enable metastatic bone healing and avoid surgery in many lesions. However, radiological PD lesions often require surgery after radiotherapy.View full abstractDownload PDF (284K) -
Naoki HAYASHI, Kenji TAKAHASHI, Ikuo KASHIWAKURA2010 Volume 51 Issue 2 Pages 137-144
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: January 07, 2010JOURNAL FREE ACCESSIn our previous study (Life Sciences 84: 598, 2009), we demonstrated that placental/umbilical cord blood-derived mesenchymal stem cell-like stromal cells have the effect to support the regeneration of freshly prepared X-irradiated hematopoietic stem/progenitor cells (HSPCs). Generally, HSPCs are supplied from companies, institutions, and cell banks that cryopreserve them for clinical and experimental use. In this study, the influence of cryopreservation on the responses of HSPCs to irradiation and co-culture with stromal cells is assessed. After cryopreservation with the optimal procedure, 2 Gy-irradiated HSPCs were cultured with or without stromal cells supplemented with combination of interleukin-3, stem cell factor, and thrombopoietin. The population of relatively immature CD34+/CD38– cells in cryopreserved cells was significantly higher than in fresh cells prior to cryopreservation; furthermore, the hematopoietic progenitor populations of CD34+/CD45RA+ cells and CD34+/CD117+ cells in cryopreserved cells were significantly lower than that in fresh cells. However, the rate of expansion in the cryopreserved HSPCs was lower than in the fresh HSPCs. In the culture of cryopreserved cells irradiated with 2 Gy, the growth rates of CD34+ cells, CD34+/CD38– cells, and hematopoietic progenitors were greater than growth rates of their counterparts in the culture of fresh cells. Surprisingly, the effect to support the hematopoiesis in co-culture with stromal cells was never observed in the X-irradiated HSPCs after cryopreservation. The present results demonstrated that cryopreserving process increased the rate of immature and radio-resistant HSPCs but decreased the effects to support the hematopoiesis by stromal cells, thus suggesting that cryopreservation changes the character of HSPCs.View full abstractDownload PDF (603K) -
Tetsuo YAMAMOTO, Manabu KINOSHITA, Nariyoshi SHINOMIYA, Sadayuki HIROI ...2010 Volume 51 Issue 2 Pages 145-156
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: December 04, 2009JOURNAL FREE ACCESSWhile bone marrow or stem cell transplantation can rescue bone marrow aplasia in patients accidentally exposed to a lethal radiation dose, radiation-induced irreversible gastrointestinal damage (GI syndrome) is fatal. We investigated the effects of ascorbic acid on radiation-induced GI syndrome in mice. Ascorbic acid (150 mg/kg/day) was orally administered to mice for 3 days, and then the mice underwent whole body irradiation (WBI). Bone marrow transplantation (BMT) 24 h after irradiation rescued mice receiving a WBI dose of less than 12 Gy. No mice receiving 14 Gy-WBI survived, because of radiation-induced GI syndrome, even if they received BMT. However, pretreatment with ascorbic acid significantly suppressed radiation-induced DNA damage in the crypt cells and prevented denudation of intestinal mucosa; therefore, ascorbic acid in combination with BMT rescued mice after 14 Gy-WBI. DNA microarray analysis demonstrated that irradiation up-regulated expressions of apoptosis-related genes in the small intestine, including those related to the caspase-9-mediated intrinsic pathway as well as the caspase-8-mediated extrinsic pathway, and down-regulated expressions of these genes in ascorbic acid-pretreated mice. Thus, pretreatment with ascorbic acid may effectively prevent radiation-induced GI syndrome.View full abstractDownload PDF (1071K) -
- Delineation of GTV by Evaluating SUV -Fumiaki UTO, Eiji SHIBA, Seiitchi ONOUE, Hitoshi YOSHIMURA, Mami TAKAD ...2010 Volume 51 Issue 2 Pages 157-164
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: December 01, 2009JOURNAL FREE ACCESSWe assessed the usefulness of PET/CT images to determine the target volume in radiotherapy planning by evaluating the standardized uptake value (SUV). We evaluated the imaging conditions and image-reconstruction conditions of PET/CT useful for treatment planning by collecting 18F-FDG images of acrylic spheres (10–48 mm in diameter) in a phantom. The 18F-FDG concentration in the spheres was 10-fold higher than that of the phantom. The contours were delineated according to the SUV by the threshold and regions of interest (ROI) methods. Comparisons of two- and three-dimensional (2D and 3D) acquisition images indicated that the sharpness and quantitative qualities of the sphere boundaries were better in the former than in the latter. In the extraction of outlines using the SUV, outlines obtained at an SUV of 40–50% of the maximum agreed well with the actual acrylic sphere size. 2D acquisition images are more suitable for delineating target volume contours, although 3D acquisition images are more popular in diagnostic imaging. An SUV of 40–50% of the maximum is suggested to be appropriate for GTV contouring of sphere tumors with homogenously distributed 18F-FDG.View full abstractDownload PDF (817K) -
Masayuki HIDAKA, Shoji ODA, Yoshikazu KUWAHARA, Manabu FUKUMOTO, Hiros ...2010 Volume 51 Issue 2 Pages 165-171
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: December 01, 2009JOURNAL FREE ACCESSIt was reported that the radiation-sensitive Medaka mutant "ric1" has a defect in the repair of DNA double-strand breaks (DSBs) induced by γ-rays during early embryogenesis. To study the cellular response of a ric1 mutant to ionizing radiation (IR), we established the mutant embryonic cell lines RIC1-e9, RIC1-e42, RIC1-e43. Following exposure to γ-irradiation, the DSBs in wild-type cells were repaired within 1 h, while those in RIC1 cells were not rejoined even after 2 h. Cell death was induced in the wild-type cells with cell fragmentation, but only a small proportion of the RIC1 cells underwent cell death, and without cell fragmentation. Although both wild-type and RIC1 cells showed mitotic inhibition immediately after γ-irradiation, cell division was much slower to resume in the wild-type cells (20 h versus 12 h). In both wild-type and RIC1 cells, Ser139 phosphorylated H2AX (γH2AX) foci were formed after γ-irradiation, however, the γH2AX foci disappeared more quickly in the RIC1 cell lines. These results suggest that the instability of γH2AX foci in RIC1 cells cause an aberration of the DNA damage response. As RIC1 cultured cells showed similar defective DNA repair as ric1 embryos and RIC1 cells revealed defective cell death and cell cycle checkpoint, they are useful for investigating DNA damage responses in vitro.View full abstractDownload PDF (592K) -
Shang-Wen CHEN, Ji-An LIANG, An-Chang SHIAU, Chun-Yen YU, Yao-Ching HU ...2010 Volume 51 Issue 2 Pages 173-179
Published: 2010
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSThis study aimed to assess the dose-rate effect of 192Ir source activity on pelvic control and late complications following high-dose-rate intracavitary brachytherapy (HDRICB) for cervical cancer patients. Two hundred and twelve patients were enrolled in this study. They were treated with external beam radiotherapy to the pelvis, after which HDRICB was performed using 192Ir remote after-loading at 1-week intervals for 4 or 5 sessions. Source activity was defined as the average of source activity in each HDRICB session. Dose-rate effect was analyzed after stratification of stage and biologically effective dose (BED). The 5-year pelvic relapse-free survival was 88% for all patients. Forty-two patients developed late rectal complications (13 grade 1, 23 grade 2, 6 grade 3–4). Twenty-seven patients had grade 2 and higher late bladder complications (14 grade 2, 13 grade 3–4). There was no dose-rate effect on pelvic control or complications when source activity was stratified. Multivariate analysis demonstrated a high risk of grade 2 and higher rectal sequelae in patients whose rectal BED ≥ 110 Gy3 (p = 0.039, hazard ratio 2.05). The high risk factors for grade 2 and higher bladder complications were a bladder BED ≥ 100 Gy3 (p = 0.03, hazard ratio 4.37). This study demonstrated no dose-rate effect of 192Ir source in HDRICB for cervical cancer in terms of pelvic control or radiation injuries. Careful monitoring of the BED values for rectum and bladder is a scrutinizing factor for minimizing late sequelae.View full abstractDownload PDF (349K) -
Yoichiro HOSOKAWA, Yasunori SAKAKURA, Kazuharu IRIE, Kohsei KUDO, Ikuo ...2010 Volume 51 Issue 2 Pages 181-186
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: January 07, 2010JOURNAL FREE ACCESSIrradiation before tooth extraction delays wound healing in the alveolar socket. This study examined the influences of local and whole body irradiation before tooth extraction on appearance of osteoblasts in the alveolar bone of rat maxillary first molars because bone formation is observed at the initial phase of wound healing. Several osteoblasts were generated 3 days after tooth extraction, and the number of cells increased day by day. Morphological studies showed there were little differences between local irradiation and non-irradiated controls. In contrast, the extraction wound in the whole body irradiation group showed delayed healing, and there was poor granulation tissue and very few osteoblasts at the bottom of the socket. An ultrastructural study showed that the osteoblasts in the extraction socket of whole body irradiation rats were smaller, and had poorly developed organelles. Injection of bone marrow cells to whole body-irradiated animals immediately after tooth extraction partially restored the number of osteoblasts. New periosteal bone formations outside of sockets showed little delay in the whole body irradiation group. These findings suggest that bone formation in the wound healing of extraction socket requires bone marrow cells from hematopoietic organs such as the bone marrow as well as local sources around the alveolar socket, during the initial phase of wound healing.View full abstractDownload PDF (843K) -
Seiji YAMASAKI, Eri SHIMADA, Tomoe KUWANO, Tae KAWANO, Naoto NOGUCHI2010 Volume 51 Issue 2 Pages 187-196
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: January 29, 2010JOURNAL FREE ACCESSMost trichomes on the surface of cucumber (Cucumis sativus L.) cotyledons consist of three cells. We previously showed that continuous UV-B (290–320 nm) irradiation induces rapid cellular expansion and the accumulation of polyphenolic compounds, possibly stress lignin, in epidermal cells around these trichomes.1) To examine the mechanism of the UV-B-induced cellular expansion and to determine which step is stimulated by UV-B irradiation in the lignin synthesis pathway, we investigated relative DNA contents in epidermal cells, including trichomes, and enzyme activity and gene expression in the phenylpropanoid pathway. UV-B irradiation increased the ploidy level over 15 days, specifically in the epidermal cells surrounding trichomes, but not in the other epidermal cells or trichomes. In epidermal cells surrounding trichomes, UV-B irradiation induced peroxidase (POX) activity from days 7 to 15. In cotyledons, UV-B exposure induced CS-POX1 and CS-POX3 gene expression within 2 days, and it also induced two other enzymes in the phenylpropanoid pathway, sinapyl alcohol dehydrogenase and coniferyl alcohol dehydrogenase, from days 9 to 11. Thus, exposure to UV-B induces expansion, endoreduplication, POX activity, and the accumulation of polyphenolic compounds in epidermal cells surrounding the trichomes of cucumber cotyledons. Because polyphenolic compounds such as lignin absorb UV-B, our data indicate a physiological protective mechanism against UV-B irradiation in cucumber.View full abstractDownload PDF (1062K) -
Ayanori MURATAKA, Satoru ENDO, Yasuaki KOJIMA, Kiyoshi SHIZUMA2010 Volume 51 Issue 2 Pages 197-203
Published: 2010
Released on J-STAGE: March 25, 2010
Advance online publication: January 29, 2010JOURNAL FREE ACCESSPhotoactivation of nuclear isomer 115mIn with a halflife of 4.48 h occurs by 60Co γ-ray irradiation. This is because the resonance γ-ray absorption occurs at 1078 keV level for stable 115In, and that energy γ-rays are produced by Compton scattering of 60Co primary γ-rays. In this work, photoactivation of 115mIn was applied to estimate the dose rate distribution around a 60Co irradiation source utilizing a standard dose rate taken by alanine dosimeter. The 115mIn photoactivation was measured at 10 to 160 cm from the 60Co source. The derived dose rate distribution shows a good agreement with both alanine dosimeter data and Monte Carlo simulation. It is found that angular distribution of the dose rate along a circumference at radius 2.8 cm from the central axis shows ± 10% periodical variation reflecting the radioactive strength of the source rods, but less periodic distribution at radius 10 and 20 cm. The 115mIn photoactivation along the vertical direction in the central irradiation port strongly depends on the height and radius as indicated by Monte Carlo simulation. It is demonstrated that 115mIn photoactivation is a convenient method to estimate the dose rate distribution around a 60Co source.View full abstractDownload PDF (1276K) -
Ki-Bum KIM, Hae-Ok BYUN, Na-Kyung HAN, Young-Gyu KO, Hyung-Do CHOI, Na ...2010 Volume 51 Issue 2 Pages 205-213
Published: 2010
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSAlthough many in vitro studies have previously been conducted to elucidate the biological effects of radio frequency (RF) radiation over the past decades, the existence and nature of any effects is still inconclusive. In an effort to further elucidate this question, we have monitored changes in protein expression profiles in RF-exposed MCF7 human breast cancer cells using two-dimensional gel electrophoresis. MCF7 cells were exposed to 849 MHz RF radiation for 1 h per day for three consecutive days at specific absorption rates (SARs) of either 2 W/Kg or 10 W/kg. During exposure, the temperature in the exposure chamber was kept in an isothermal condition. Twenty-four hours after the final RF exposure, the protein lysates from MCF cells were prepared and two-dimensional electrophoretic analyses were conducted. The protein expression profiles of the MCF cells were not significantly altered as the result of RF exposure. None of the protein spots on the two-dimensional electrophoretic gels showed reproducible changes in three independent experiments. To determine effect of RF radiation on protein expression profiles more clearly, three spots showing altered expression without reproducibility were identified using electrospray ionization tandem mass spectrometry analysis and their expressions were examined with RT-PCR and Western blot assays. There was no alteration in their mRNA and protein levels. As we were unable to observe any significant and reproducible changes in the protein expression profiles of the RF radiation-exposed MCF7 cells using high throughput and non-high throughput techniques, it seems unlikely that RF exposure modulates the protein expression profile.View full abstractDownload PDF (581K) -
Shingo KATO, Dang Ngoc Linh TRAN, Tatsuya OHNO, Takashi NAKANO, Hiroki ...2010 Volume 51 Issue 2 Pages 215-221
Published: 2010
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSThis study evaluated the efficacy of computed tomography (CT)-based three-dimensional (3D) dose-volume parameters of the rectum as predictor for late rectal complication (LRC) in cervical cancer patients treated with radiotherapy alone. Eighty-four patients treated with a combination of external radiotherapy and high-dose-rate intracavitary brachytherapy between January 2000 and December 2004 were retrospectively analyzed. Brachytherapy was prescribed with standard 2D planning. Patients underwent pelvic CT at brachytherapy. The external rectal wall was contoured on the CT images, and the minimum doses delivered to 0.1cc, 1cc, and 2cc of the most irradiated rectal volumes were calculated with dose-volume histograms. The International Commission of Radiation Units and Measurements (ICRU) rectal point dose was also calculated by conventional method. Total dose (external radiotherapy plus brachytherapy) to the rectum was transformed to the biologically equivalent dose in 2-Gy fractions with α/β of 3 Gy (D0.1cc, D1cc, D2cc and DICRU). The relationships between these dosimetric parameters and the incidence of LRC were analyzed. The 5-year overall actuarial rate of LRC was 26.4%. The values of D0.1cc, D1cc, and D2cc were significantly higher in patients with LRC than in those without (p < 0.001), but the difference in the values of DICRU was not statistically significant (p = 0.10). The rate of LRC increased significantly with increasing D0.1cc, D1cc, and D2cc (p = 0.001). However, no positive dose-response relationship was observed between DICRU and the rate of LRC (p = 0.42). The present study has suggested that CT-based 3D dose-volume parameters of the rectum may be effective for predicting LRC.View full abstractDownload PDF (621K)
Miscellaneou
-
2010 Volume 51 Issue 2 Pages Cover02_1-Cover02_8
Published: 2010
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSDownload PDF (626K)
- |<
- <
- 1
- >
- >|