• Title/Summary/Keyword: Low Dose Exposure

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Comparative effect of genistein and daidzein on the expression of MCP-l, eNOS, and cell adhesion molecules in TNF-${\alpha}$-stimulated HUVECs

  • Cho, Hye-Yeon;Park, Chung-Mu;Kim, Mi-Jeong;Chinzorig, Radnaabazar;Cho, Chung-Won;Song, Young-Sun
    • Nutrition Research and Practice
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    • v.5 no.5
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    • pp.381-388
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    • 2011
  • We compared the effects of genistein and daidzein on the expression of chemokines, cell adhesion molecules (CAMs), and endothelial nitric oxide synthase (eNOS) in tumor necrosis factor (TNF)-${\alpha}$-stimulated human umbilical vascular endothelial cells (HUVECs). TNF-${\alpha}$ exposure significantly increased expression of monocyte chemoattractant protein (MCP)-l, vascular adhesion molecule (VCAM)-1, and intercellular adhesion molecule-1. Genistein significantly decreased MCP-l and VCAM-l production in a dose-dependent manner, whereas CAM expression was not significantly lowered by genistein treatment. However, daidzein slightly decreased MCP-l production. The effects of genistein and daidzein on MCP-l secretion coincided with mRNA expression. Pre-treatment with either genistein or daidzein elevated eNOS expression and nitric oxide production disturbed by TNF-${\alpha}$ exposure. A low concentration of isoflavones significantly inhibited nuclear factor (NF)${\kappa}$B activation, whereas a high dose slightly ameliorated these inhibitive effects. These results suggest that genistein had a stronger effect on MCP-l and eNOS expression than that of daidzein. Additionally, NF${\kappa}$B transactivation might be partially related to the down-regulation of these mRNAs in TNF-${\alpha}$-stimulated HUVECs.

Anticancer and Radiosensitization Efficacy of Nanocomposite Withania somnifera Extract in Mice Bearing Tumor Cells

  • Abdallah, Nadia M;Noaman, Eman;Eltahawy, Noaman A;Badawi, Abdelfattah M;Kandil, Eman;Mansour, NA;Mohamed, Hebatallah E
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.9
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    • pp.4367-4375
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    • 2016
  • The objective of the present study was to evaluate the anticancer and radio-sensitizing efficacy of a Withania somnifera extract/Gadolinium III oxide nanocomposite (WSGNC) in mice. WSGNC was injected to solid Ehrlich carcinoma-bearing mice via i.p. (227 mg/kg body weight) 3 times/week during 3 weeks. Irradiation was performed by whole body fractionated exposure to 6Gy, applied in 3 doses of 2 Gy/week over 3 weeks. Biochemical analyses as well as DNA fragmentation were performed. Treatment of solid Ehrlich carcinoma bearing mice with WSGNC combined with ${\gamma}$-radiation led to a significant decrease in the tumor size and weight associated with a significant decrease in mitochondrial enzyme activities, GSH content and SOD activity as well as a significant increase in caspase-3 activity, MDA concentration and DNA fragmentation in cancer tissues. Combined treatment of WSGNC and low dose of ${\gamma}$-radiation showed great amelioration in lipid peroxidation and antioxidant status (GSH content and SOD activity) in liver tissues in animals bearing tumors. It is concluded that WSGNC can be considered as a radio-sensitizer and anticancer modulator, suggesting a possible role in reducing the radiation exposure dose during radiotherapy.

Automatic Control of Fraction of Inspired Oxygen in Neonatal Oxygen Therapy using Fuzzy Logic Control

  • Chanyagorn, Pornchai;Kiratiwudhikul, Phattaradanai
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.2
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    • pp.107-116
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    • 2016
  • Premature babies of less than 37 weeks gestation might require oxygen therapy as an integral part of treatment and respiratory support. Because of their under-developed lungs, these so-called "preemies" might contract respiratory distress syndrome (RDS). To treat RDS, neonatal oxygen therapy is administered, where controlled oxygen gas is measured as a fraction of inspired oxygen ($FiO_2$). However, exposure to high oxygen content during long treatment could cause oxygen intoxication, which might cause permanent blindness due to retinopathy of prematurity (ROP), whereas insufficient oxygen exposure could cause severe hypoxia. A doctor would use oxygen saturation ($SpO_2$) data and prescribe a dose of $FiO_2$ to maintain $SpO_2$ within a suitable range. One objective is to maintain $SpO_2$ within the acceptable range using $FiO_2$ that is as low as possible. Adjustment of $FiO_2$ would normally be done by nurses every 15 to 30 minutes, which might not be safe in many situations. An error in $FiO_2$ adjustment during a manual procedure could be as large as +/- 2.5%. This paper presents a system that can determine an $FiO_2$ value suitable to the current $SpO_2$ and that automatically adjusts $FiO_2$ with an error clearance of +/- 0.25%.

Immunomodulatory effects of silymarin after subacute exposure to mice: A tiered approach immunotoxicity screening

  • Karimi, Gholamreza;Hassanzadeh-Josan, Samed;Memar, Bahram;Esmaeili, Seyed-Alireza;Riahi-Zanjani, Bamdad
    • Journal of Pharmacopuncture
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    • v.21 no.2
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    • pp.90-97
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    • 2018
  • Silymarin is a flavonoid complex extracted from the Silybum marianum plant with a wide range of pharmacological and biochemical effects. In the present study, the immunomodulatory effects of silymarin were investigated in BALB/c mice. Silymarin was administered daily by intraperitoneal injection at doses of 50, 100 and 150 mg/kg for 14 consecutive days. Following the exposure, host hematological parameters, spleen cellularity and histopathological examination, as well as delayed-type hypersensitivity (DTH) responses, hemagglutination titers (HA), splenocyte cytokine production and lymphocyte proliferation assay were studied in all of the test groups of animals. The results showed that the low dose of silymarin (50 mg/kg) could stimulate both cellular and humoral immune functions in the treated hosts. In addition, silymarin at 100 mg/kg appeared to impact on DTH responses and lymphoproliferation. Based on the finding here, it would seem that silymarin has efficient immunostimulant properties. As a recommendation, the application of silymarin along with acupuncture technique (herbal acupuncture) can be thought as a good plan to modulate and enhance the immune system for the management of several immunodeficiency disorders. However, further studies are required to demonstrate this hypothesis.

Evaluation of radiological safety according to accident scenarios for commercialization of spent resin mixture treatment device

  • Choi, Woo Nyun;Byun, Jaehoon;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2606-2613
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    • 2022
  • Spent resin often exceeds radiation limits for safe disposal, creating a need for commercial-scale treatment techniques to reduce resin radioactivity. In this study, the radiological safety of a commercialized spent resin treatment device with a treatment capacity of 1 ton/day was evaluated. The results confirm that the device is radiologically safe in the event of an accident. This device desorbs 14C from the spent resin, allowing disposal as low-level waste instead of intermediate-level waste. The device also reduces overall waste by recycling the extracted 14C. Potential accident scenarios were explored to enable dose assessments for both internal and external exposure while preventing further spillage of the device and processing the spilled resin. The scenarios involved the development of a surface fracture on the resin mixture separator and microwave systems, which were operated under pressure and temperature of 0-6 bar and 0-150 ℃, respectively. In the case of accidents with separator and microwave device, the maximum allowable working time of worker were derived, respectively, considering external and internal exposures. When wearing the respirator corresponding to APF 50, in the case of the microwave device accident scenario, the radiological safety was confirmed when the maximum worker worked within 132.1 h.

Reduced Effect of kV-CBCT Dose by Use of Shielding Materials in Radiation Therapy (방사선 치료 시 차폐물질 사용에 따른 kV-CBCT 선량감소 효과)

  • Jo, Hyeonjong;Park, Euntae;Kim, Junghoon
    • Journal of the Korean Society of Radiology
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    • v.12 no.4
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    • pp.467-474
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    • 2018
  • CBCT is useful for improving the accuracy of the treatment site, but Repeated use increases the exposure dose. In this study, we aimed to provide basic data for dose reduction in CBCT implementation by dataization the simulating and dose reduction effect using shielding substance. Material in this study, Analyzation the photon beam by simulate the CBCT Through MCNPX and then calculate the absorption dose of body organ at shooting moment of thoracic abdominal position as target UF-Revise simulated body. At this time. Dose reduction effects at this time were evaluated according to the texture of materials and presence of shielding materials( lead, antimony, barium, sulfate, tungsten, bismuth). When CBCT was taken without shielding, the dose was calculated to be high in the breast and spine, and the dose in the esophagus and lung was calculated to be low. The doses according to the shield material were calculated as barium sulfate, antimony, bismuth, lead, and tungsten. The shielding rate was the highest in the thymus (73.6%) and the breast (59.9%) compared with the dose reduction according to presence or absence of the shield. However, it showed the lowest shielding rate in lung (2.1%) and spine (12.6%).

Influences of the Plant Growth under Beta-Rays Irradiation at Low Dose (저 선량 베타선의 조사에 의한 식물의 생장에 미치는 영향)

  • Lee, Byung-Koo;Im, In-Chul;Kim, Jong-Eon
    • Journal of radiological science and technology
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    • v.33 no.2
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    • pp.143-148
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    • 2010
  • This study is to analyze effects of the growth of Chunhyang Young Radish (CYR) and Altari Radish (AR) according to the exposure for 31 days at low dose ${\beta}$-rays. This test has one contrast sample and eleven test samples each as to AR and CYR. The seeds from contrast and test sample were planted in the culture soil after 8 seeds were chosen from each with identical condition. The accumulated dose of test samples has been measured at consistent time on a daily basis for 31 days. The growing process and germination have been measured twice at consistent time in each week. The number of leaves, length of first leave and weight have been acquired average value by measuring for 20 and 25 days, respectively after being planted. The result of test sample in case of 25 days shows that 5% increase in length and 36% increase in weight for AR each at accumulated dose 0.01 Gy compared to the contrast sample. And the length of CYR has increased by 13~17% and 1% at accumulated dose 0.01~0.08 Gy and 0.3 Gy compared to the contrast sample. For the weight at accumulated dose 0.05 Gy and 0.23 Gy has increased by 36% and 2% compared to contrast sample. As to the number of leaves, AR has increased by 0~50% at accumulated dose 0.01-0.32 Gy compared to contrast sample. It also shows that the CYR has increased to 0~67% at accumulated dose 0.01-0.62 Gy compared to contrast sample. As a result of this study, it indicates that both AR and CYR has generally increased in their length, weight, and the number of leaves at low level accumulated dose part 0.01~0.2 Gy. The size of cell, area of nucleus and density of cell for test sample has been observed quite similar to the ones from contrast sample through microscope. In conclusion, AR and CYR irradiated by ${\beta}$-rays have estimated that they are achieved a rapid growth at low level accumulated dose region corresponding to its radiation hormesis theory. Further studies need to confirm the correlation between the radiation hormesis and the growth of the plants.

Effects of Gamma Irradiation on Quality Characteristics of Low-salt Fermented Pollack Theragra chalcogramma Roe (감마선 조사가 저염 명란(Theragra chalcogramma) 젓갈의 품질에 미치는 영향)

  • Nam, Ki-Ho;Lee, Hyun-Jin;Park, No-Hyun;Kim, Dong-Hwan;Song, Min-Gyu;Kim, Jong-Il;Oh, Kwang-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.3
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    • pp.302-309
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    • 2022
  • Low-salt fermented pollack Theragra chalcogramma roe (Myungran Jeotgal, MJ), a traditional Korean fermented seafood, was prepared using a commercially available method and irradiated using gamma rays (0-10.0 kGy) to investigate the effect of gamma irradiation (GI) on food quality. After irradiation with 2.5 kGy gamma rays, the number of viable cells in MJ was reduced by one log compared to that observed in non-irradiated MJ, and no living cells were detected after 7.5 kGy GI. Though up to 2.5 kGy GI had no effect on color quality, over 7.5 kGy GI resulted in significantly poor quality MJ surface color. Saturated fatty acid contents increased slightly in irradiated MJ, while those of polyenes and monoenes decreased slightly as the GI dose increased. Exposure of MJ to GI had no effect on the free amino acid and mineral composition. These results demonstrated that the appropriate GI dose for MJ ranged from 2.5 to 5.0 kGy, which may be recommended for industrial application.

Dosimetric comparison between modulated arc therapy and static intensity modulated radiotherapy in thoracic esophageal cancer: a single institutional experience

  • Choi, Kyu Hye;Kim, Jina;Lee, Sea-Won;Kang, Young-nam;Jang, HongSeok
    • Radiation Oncology Journal
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    • v.36 no.1
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    • pp.63-70
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    • 2018
  • Purpose: The objective of this study was to compare dosimetric characteristics of three-dimensional conformal radiotherapy (3D-CRT) and two types of intensity-modulated radiotherapy (IMRT) which are step-and-shoot intensity modulated radiotherapy (s-IMRT) and modulated arc therapy (mARC) for thoracic esophageal cancer and analyze whether IMRT could reduce organ-at-risk (OAR) dose. Materials and Methods: We performed 3D-CRT, s-IMRT, and mARC planning for ten patients with thoracic esophageal cancer. The dose-volume histogram for each plan was extracted and the mean dose and clinically significant parameters were analyzed. Results: Analysis of target coverage showed that the conformity index (CI) and conformation number (CN) in mARC were superior to the other two plans (CI, p = 0.050; CN, p = 0.042). For the comparison of OAR, lung V5 was lowest in s-IMRT, followed by 3D-CRT, and mARC (p = 0.033). s-IMRT and mARC had lower values than 3D-CRT for heart $V_{30}$ (p = 0.039), $V_{40}$ (p = 0.040), and $V_{50}$ (p = 0.032). Conclusion: Effective conservation of the lung and heart in thoracic esophageal cancer could be expected when using s-IMRT. The mARC was lower in lung $V_{10}$, $V_{20}$, and $V_{30}$ than in 3D-CRT, but could not be proven superior in lung $V_5$. In conclusion, low-dose exposure to the lung and heart were expected to be lower in s-IMRT, reducing complications such as radiation pneumonitis or heart-related toxicities.

Radiation Doses and Quality Assurance in Cone Beam CT(CBCT) (임상가를 위한 특집 4 - CBCT 검사법의 정도관리 및 선량)

  • Choi, Yong-Suk;Kim, Gyu-Tae;Hwang, Eui-Hwan
    • The Journal of the Korean dental association
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    • v.52 no.3
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    • pp.153-163
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    • 2014
  • 3-dimensional information for anatomic stucture plays a role as integral part in clinical aspect of dental practice. CBCT(cone beam computed tomography) has been accepted as useful diagnostic tool offering Volume data and images for evaluating teeth and jaws in lower radiation dose than conventional CT. CBCT equipment is essential for the quality assurance of it to ensure continued satisfactory performance and result of adequate images. Dental practitioner and oral and maxillofacial radiologist should have a responsibility and critical thinking to deliver this technology to patients in a responsible way, so that diaganostic value is maximised and radiation doses kept as low as resonably achievable. CBCT imaging modality should be used only after a review of the patient's health and imaging history and the completion of a thorough clinical examination. Clinical guidelines are systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances Dental practitioners should prescribe CBCT imaging only when they expect that the diagnostic yield will benefit patient care, enhance patient safety or improve clinical outcomes significantly. Knowledge of patient dose is essential for clinicians who are making the decision regarding the justification of the exposure. There are some limitation in the measurement of patient dose in CBCT for the approval and adaptation of conventinal methodolgy in CT. It is also important to ensure that doses are optimised and in line with any national and international guidelines. The higher radiation doses of CBCT compared with conventional radiography, mean that high standards must be maintained. The Quality Assurance(QA) programme should entail surveys and checks that are performed according to a regular timetable. QA programme should be maintained by staff to ensure adherence to the programme and to raise its importance among staff.