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Showing 57 results for Yu
Dr. M.r. Adhvaryu, S.p. Srivastav, S.n. Vaniawala, M.n. Reddy, Volume 6, Issue 1 (6-2008)
Abstract
Background: Synthetic radio-protective agents like
aminothiols are toxic and FDA approved agent
amifostine is no exception. Some Ayurvedic herbs have
shown radioprotective potential. This study was carried
out to test and compare the radioprotective potential
of Curcuma longa (CL) Tinospora cordifolia (TC),
Zizyphus mauritiana (ZM) and Ocimum sanctum (OS)
against 2Gy gamma irradiation in Swiss albino mice.
Materials and Methods: Adult Swiss albino mice
from random breed colony were divided in to 6 groups
(n=9), sham-control (SCT), radiation control (RACT),
and four herb + radiation groups respectively. All
except SCT were exposed to whole body 2 Gy of
gamma radiation in a teletherapy unit and SCT was
sham exposed on day 7 of herb pretreatment
(200mg/kg-bw orally by gavage). Chromosomal
studies from the bone marrow of femur by routine
metaphase preparation after colchicine treatment
were done in 3 animals from each group at 24, 72 and
168 hours after exposure. Results: All four herbs
showed significant radio-protective effects at 24 hrs.
OS, TC and ZM showed nearly similar activity while CL
showing the lowest activity. However the effects at 72
and 168 hrs showed highest protection by CL followed
by ZM |“| TC > OS respectively suggesting that the well
studied OS was less effective at 72 and 168 hrs.
Conclusion: All the four herbs showed radioprotective
potential with different efficacies at
different time interval. Iran. J. Radiat. Res., 2008 6 (1): 19-
30
Dr. M.n. Salihin Yusoff, A. Zakaria, Volume 6, Issue 4 (3-2009)
Abstract
Background: Butterworth, Gaussian, Hamming, Hanning, and Parzen are commonly used SPECT filters during filtered back-projection (FBP) reconstruction, which greatly affect the quality and size accuracy of image. Materials and Methods: This study involved a cardiac phantom in which 1.10 cm thick cold defect was inserted into its myocardium wall and filled with 4.0 μCi/ml (0.148 MBq/ml) 99mTc concentration. The cardiac insert was then put into a cylindrical tank which was filled with 1.2 μCi/ml (0.044 MBq/ml) 99mTc concentration as background. 272 combinations of filter parameters were selected from those filters and applied on image. The measurements of count in myocardium, background, and defect regions of interest (ROI) were performed on each filtered image. Those measurements were then used to calculate contrast, signal-to-noise ratio (SNR), and defect size. For every filter, each criterion was graded (1 to 100) and then summed at their specific setting for total comparison. Results: The results show that, the different filter types produced myocardial image with different contrast, SNR, and defect size. For contrast and SNR, Gaussian filter was the best, while Parzen filter was the best in producing accurate defect size. However, Butterworth filter was found the best for trade off between contrast, SNR, and defect size accuracy. Conclusion: Selection of filter should consider the type of analysis, whether qualitatively or quantitatively. Qualitative analysis depends on image quality which is denoted by high contrast and SNR, thus Gaussian filter was suggested. Instead, the Butterworth filter was suggested for quantitative analysis as it is greatly dependent on both, image quality and size accuracy. Iran. J. Radiat. Res., 2009 6 (4): 173-182
Dr. M.n. Salihin Yusoff, A. Zakaria, Volume 8, Issue 1 (6-2010)
Abstract
Background: We investigated whether the lungheart
ratio parameter (LHR) can be used to identify
the optimum cut off frequency for Butterworth filter in
99mTc myocardial SPECT imaging. Materials and
Methods: This study involved a cardiac phantom
system consisting of cardiac insert in which 1.10 cm
cold defect was inserted into its myocardium wall and
filled with 4.0 μCi/ml (0.148 MBq/ml) 99mTc
concentration. The cardiac insert was then put into a
cylindrical tank which filled with six different 99mTc
concentrations as background. Thus, six target background
concentrations ratios (T/B) were carried
out. The LHR was determined for every SPECT raw
image obtained corresponding to each T/B. Then,
130 different combinations of filter parameters from
Butterworth filter were utilized to reconstruct each
SPECT raw image. The determination of count in
myocardium, background, and defect regions of
interest (ROI) were performed for every reconstructed
image. All the count values were then used to calculate
contrast, signal-to-noise ratio (SNR), and defect
size. Each criterion was graded (1 to 100) and then
summed together to obtain total grade. The optimum
cut off frequency for each LHR was determined from
the total grade. The relation between optimum cut off
frequency for Butterworth filter and LHR was
established using linear regression. Results: There
were good relationship between the optimum Butterworth
cut off frequency and LHR (R2 = 0.864, p <
0.01). The optimal cut off frequency correspond to
the change in LHR can be expressed by the equation:
Optimum cut off frequency = 0.715*LHR + 0.227.
Conclusion: This study suggests that the optimum cut
off frequency for Butterworth filter should be determined
by referring to LHR in each patient study. Iran.
J. Radiat. Res., 2010 8 (1): 17-24
Y.j. Go, J.h. Shin, K.s. Jeong, S.j. Park, S.h. Kim, S.y. Ryu, C.h. Kim, E.j. Kim, Dr. Ch.m. Kang, Dr. Th. Kim, Volume 8, Issue 4 (3-2011)
Abstract
Background: The purpose of this paper is to
establish an easy and reliable biodosimeter protocol
to evaluate the biological effects of proton beams.
Materials and Methods: Human peripheral blood
lymphocytes were irradiated using proton beams (LET:
34.6 keV μm−1), and the chromosome aberrations
induced were analyzed using cytokinesis-blocked (CB)
micronucleus (MN) assay. To determine the efficiency
of MN assay in estimating the doses received by
50MeV proton beams and to monitor predicted dose
of victims in accidental exposure, here we have
evaluated the performance of MN analysis in a
simulated situation after exposure with proton
beams. Peripheral lymphocytes were irradiated by
50MeV proton beams up to 6Gy and analyzed by
Giemsa staining of CB MN assay. Results: The
detected MN was found to be a significant dose-effect
curve in the manner of dose-dependent increase
after exposure with proton beams in vitro. When
plotting on a linear scale against radiation dose, the
line of best fit was Y=0.004+(1.882x10-2±9.701x10-5) D+(1.43x10-3±1.571x10-5)D2. Our results show a
trend towards increase of the number of MN with
increasing dose. It was linear-quadratic and has a
significant relationship between the frequencies of
MN and dose (R2= 0.9996). The number of MN in
lymphocyte that was observed in control group is
5.202±0.04/cell. Conclusion: Hence, this simple
protocol will be particularly useful for helping physicians
to decide medical therapy for the initial treatment
of victims with rapid and precise dose estimation
after accidental radiation exposure. Also it has
potential for use as a valuable biomarker to evaluate
the biological effectiveness for cancer therapy with
proton beams. Iran. J. Radiat. Res., 2011 8(4): 231-236
A. Termizi Ramli, Dr. A.s. Aliyu, E.h. Agba, M.a. Saleh, Volume 12, Issue 1 (1-2014)
Abstract
Background: Human is exposed to radiation in their environment with or without their consent and the exposure to natural background radiation is an unpreventable event on earth. Materials and Methods: An in situ assessment of the indoor and outdoor background radiation in Akwanga and Keffi towns of Nasarawa state Nigeria was carried out using a halogen-quenched Geiger Muller (GM) detector (Inspector alert Nuclear radiation monitor SN: 3544). Each of these towns was divided into at least 20 sampling areas where at least ten readings were taken in order to have a reliable data. Results: The mean indoor and outdoor annual effective dose of Akwanga were 1.29± 0.13mSv/yr and 0.31±0.04 mSv/yr respectively and that of Keffi were 1.08± 0.15mSv/yr and 0.25±0.04 mSv/yr respectively. The radiation levels in both highly populated towns were found to be within the safe limit for areas of normal background set by UNSCEAR (2.4 mSv/yr). Conclusion: These results would serve as a baseline upon which other exposures would be assessed and in the future, serve as reference for dosimetry and decontamination in situations of radiation poisoning of these towns.
Z. Hua, Dr. W. Zhen-Yu, Y. Xin, Y. Lin, Z. Li-Li, B. Hai-Na, L. Xiao-Yu, Volume 12, Issue 2 (4-2014)
Abstract
Background: Ionizing radiation induces the production of reactive oxygen species (ROS), which play an important causative role in cell death. The aim of this study was to investigate the protective effects of sulfated derivatives of neutral polysaccharides extracted from Auricularia auricular (SNAAP). Materials and Methods: Whole blood samples from healthy donors treated with SNAAP at different concentrations (20, 60, 100 &mug/mL) were exposed to various doses of X-rays. Wistar rat spleen lymphocytes, in cultures, were treated with SNAAP at different concentrations (20, 60, 100 &mug/mL) in the presence p.o 12 hours prior to 8 Gy gamma radiation exposure. Animals were administered with SNAAP at doses of 50, 100 or 200 mg/kg body weight d p.o 7 days prior to sub-lethal doses (6 Gy) of whole body gamma radiation exposure. Results: SNAAP is an effective radio protector against X-ray radiation induced in vitro cellular damage in human peripheral blood. Furthermore, to support this finding the effect of SNAAP on a rat’s spleen lymphocytes, when cultured and examined 24 hours after exposure to 8 Gy &gamma of radiation, demonstrated the effect of polysaccharides on a rat’s spleen lymphocytes, pretreated by the SNAAP, can increase the cell viability compared with irradiated group at a concentration of 20, 60 and 100 &mug/mL. Likewise, this radiation-induced therapy decreased each mouse’s body weight and effectively stimulated the immune system of all radiated mice. Moreover, when induced by Co60, the SNAAP decreased the level of malondialdehyde (MDA) and increased the myeloperoxidase (MPO) and the glutathione peroxidase (GSH-Px) activity in the whole blood supply of the irradiated mice. Conclusion: These encouraging results support further research into the clinical pharmacology of SNAAP as a novel agent for human radiation protection.
Dr. Sh. Fang, Y. Sun, M.p.h. Yuan Wang, Volume 12, Issue 2 (4-2014)
Abstract
Primary rhabdomyosarcoma (RMS) of the kidney is a rare malignant mesenchymal tumor with an aggressive clinical course. Adult renal RMS is typically a pleomorphic histologic subtype and only a few cases have ever been reported. We herein present a new case of renal RMS of the embryonal histologic subtype in a 26-year-old woman.
Dr. S Qibin, H. Weiguo, C. Yuxin, Xubin, C. Hao, Volume 12, Issue 3 (7-2014)
Abstract
Background: Radiation-induced lung injury is a refractory side effect in lung cancer radiotherapy, the mechanism still remains unclear, hence an appropriate animal mode may become useful to investigate it. Materials and Methods: 50 female Wistar rats were randomly divided into 5 groups, average 10 rats/cage: A. control group B. 3Gy×10f C. 6Gy×5f D. 12.5Gy×1f E.15.3Gy×1f. By different doses of radiation to the right lung of rats under American Varian linear accelerator, all the rats were executed at 30days after irradiation, lung tissues were collected to observe the pathological changes by HE staining , and additional lung tissues were extracted mRNA to measure gene expression of TNF-a and IL-18 by qRT-PCR. Results: In contrast to the control group, congestion, gore, edema, broadening alveolar interval and the bulla can be observed after irradiation. 3Gy×10f radiation led to most rat death because of frequent anaesthesia. 12.5Gy×1f radiation induced mild lung injury. 6Gy×5f and 15.3Gy×1f radiation induced remarkable lung injury. However, 15.3Gy×1f was seldom adopted in clinical settings. The measurement of cytokine variation by qRT-PCR also indicated that 6Gy×5f radiation stimulated the most obvious elevation of IL-18, while 15.3Gy×1f radiation elevated TNF-a most. Conclusion: A rat model of radiation-induced lung injury was appropriately established, 6Gy×5f radiation was the most suitable radiation method for establishing this rat model.
R. Chang-Li, C. Yu-Xin, W. Lu-Zhou, Wu-Bing, Dr. S. Qi-Bin, Volume 13, Issue 1 (1-2015)
Abstract
Background: 3DCRT (three-dimensional conformal radiotherapy) and IMRT (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. However, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. The purpose of this study is to evaluate the impact of respiratory motion on dose distributions of 3D-CRT and dynamic IMRT by simulating the respiratory motion, and provide suggestions to optimize treatment planning. Materials and Methods: American Sun Nuclear Mapcheck 2D-ARRAY was placed on a moving platform to simulate the respiratory motion. The dose distributions were measured with a Sun Nuclear Mapcheck 2D-ARRAY on the moving platform. The motion cycle was 3.5s, the amplitude was ±3mm, ±5mm, ±10mm, ±15mm. Dosimetric distribution between 3DCRT and IMRT plans were contrasted byγ-passing rate analysis. SPSS 13.0 software was used for data processing and analysis. Results: The respiratory motion could blur the target dose distribution of 3D-CRT and IMRT. The pass rate (3% 3mm) in 3DCRT was larger than that in IMRT. The Mapcheck software reflected that, the respiratory motion largely affected the marginal dose distribution of 3D-CRT, while affected the whole target volumes of IMRT. Conclusions: Respiratory motion has a greater impact on the dose distribution of IMRT than on 3D-CRT. As for tumors with large motion amplitude, it is advisable to use 3DCRT rather than IMRT techniques.
Dr. Z. Salehi, W.a. Kamil, B.m. Biswal, A.l. Yusoff, Volume 13, Issue 1 (1-2015)
Abstract
Background: The purpose of this study was to find the accurate absorbed dose in the femur bone marrow during the X-ray radiography for constant mAs and AEC techniques. Materials and Methods: The DOSXYZnrc was used to simulate radiation doses in two human femurs during diagnostic radiography. EGSnrc phantoms produced from actual CT images of human femurs were modified by adding seven micrometre layers of marrow tissues. The X-ray machine was simulated using BEAMnrc using 30 billions particles for different combinations of energies and filters. The resultant data was used to in DOSXYSnrc simulations to evaluate the absorbed dose in the human femur. Results: In the head of the femur, for 2.5 mm aluminium filtered 85 kVp X-ray set at 50 mAs, the absorbed dose in the marrow was found to be 1.360 mGy, ~ 36% of the absorbed dose in the cortical bone. It was also found that for the constant mAs technique, the radiation dose in the marrow over the studied energies and filter combination, ranges from 0.356 mGy to 2.403 mGy, with higher dose recorded for higher kVp settings. However, for the AEC technique, the dose is lower for higher kVp settings. For a typical setting, viz. 85 kVp, 6 mAs at 48 inches SID, the bone marrow absorbed dose was found to be 0.186 mGy for the constant mAs technique and 0.0308 mGy for the AEC technique. Conclusion: It was confirmed that the radiation dose is lower when the AEC exposure technique is used as opposed to using constant mAs technique. For the AEC technique, typical dose to the bone marrow was found to be ~ 0.05 mGy, decreasing with both kVp settings and beam filtration. For constant mAs technique, the typical dose to bone marrow is found to be higher, ~ 0.2 mGy, decreasing with the amount of filtration used but increasing with the kVp setting.
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