• 한국의학물리학회지:의학물리
• /
• 제25권2호
• /
• pp.65-71
• /
• 2014

A Varian Portal Dosimetry system was compared to an isocentrically mounted MapCHECK 2 diode array for volumetric modulated arc therapy (VMAT) QA. A Varian TrueBeam STx with an aS-1000 digital imaging panel was used to acquire VMAT QA images for 13 plans using four photon energies (6, 8, 10 and 15 MV). The EPID-based QA images were compared to the Portal Dose Image Prediction calculated in the Varian Eclipse treatment planning system (TPS). An isocentrically mounted Sun Nuclear MapCHECK 2 diode array with 5 cm water-equivalent buildup was also used for the VMAT QAs and the measurements were compared to a composite dose plane from the Eclipse TPS. A ${\gamma}$ test was implemented in the Sun Nuclear Patient software with 10% threshold and absolute comparison at 1%/1 mm (dose difference/distance-to-agreement), 2%/2 mm, and 3%/3 mm criteria for both QA methods. The two-tailed paired Student's t-test was employed to analyze the statistical significance at 95% confidence level. The average ${\gamma}$ passing rates were greater than 95% at 3%/3 mm using both methods for all four energies. The differences in the average passing rates between the two methods were within 1.7% and 1.6% of each other when analyzed at 2%/2 mm and 3%/3 mm, respectively. The EPID passing rates were somewhat better than the MapCHECK 2 when analyzed at 1%/1 mm; the difference was lower for 8 MV and 10 MV. However, the differences were not statistically significant for all criteria and energies (p-values >0.05). The EPID-based QA showed large off-axis over-response and dependence of ${\gamma}$ passing rate on energy, while the MapCHECK 2 was susceptible to the MLC tongue-and-groove effect. The two fluence-based QA techniques can be an alternative tool of VMAT QA to each other, if the limitations of each QA method (mechanical sag, detector response, and detector alignment) are carefully considered.

• Journal of Radiation Protection and Research
• /
• 제22권2호
• /
• pp.85-95
• /
• 1997

전통적으로 개인방사선감시에 열형광선량계와 필름배지가 공식개인선량계로 이용되어 왔고 현재까지도 여전히 가장 보편적으로 사용되고 있지만, 최근에는 Si 다이오드와 G-M관을 이용한 능동형 전자개인선량계가 개발 보급되고 있다. 전자개인선량계는 누적선량을 곧바로 알 수 있다는 분명한 장점을 가지고 있을 뿐만 아니라 선량률에 관한 정보도 제공하므로 높은 비용부담에도 불구하고 피폭관리의 용이함으로 인해 주목을 받고 있다. 이에 세 종류의 전자개인선량계 즉, EPD2, STEPHEN6000, PD-3i에 대하여 재현성, 정확성, 선형성, 에너지와 방향 의존성, 반응시간을 포함하는 선량계의 전반적인 성능을 실험적으로 평가한 후 판단기준으로 IEC standard 그리고 Ontario Hydro standard와 비교함으로써 전자개인선량계가 방사선방호의 핵심인 개인선량측정에 충분한 신뢰도를 제공하여 공식선량계로 적합한가를 논의하였다. STEPHEN6000 및 PD-3i는 표층선량 측정능력의 보완이 필요하였다.

• 동의생리병리학회지
• /
• 제17권6호
• /
• pp.1514-1518
• /
• 2003

Angelica sinensis radix, Danggui, is a traditional oriental medication, which has been used to modulate immune response. We report here that aqueous extract of Angelica sinensis radix (ASR) can induces NO production, and inhibit LPS-induced NO production in dose-dependent manner in RAW 264.7 macrophage cells. ASR also induces iNOS mRNA and iNOS protein expression, and exhibit inhibitory effect on iNOS mRNA and protein expression in a dose-dependent manner in LPS-stimulated RAW 264.7 macrophage cells. Cytokines involved in the regulation of inflammatory reaction and immune response may play a role in the pathogenesis. ASR induces. pro-inflammatory cytokine gene expression (IL-1α, IL-1β and IL-6 gene) in a dose-dependent manner, and inhibits the expressions of these cytokines in LPS-stimulated RAW 264.7 macrophage cells. These data indicate that (1) ASR may be a potential therapeutic modulator of NO synthesis in various pathological conditions, and (2) the immunomodulatory effects of ASR may be, in part, associated with the inducing or suppression of pro-inflammatory cytokine gene expressions.

• 동의생리병리학회지
• /
• 제27권1호
• /
• pp.78-82
• /
• 2013

It has been reported that Scolopendra morsitans L.(SML) has beneficial effects on human health and diverse diseases. The purpose of this study was to investigate the anti-inflammatory effects of ether extract from Scolopendra morsitans L. on lipopolysaccharide(LPS)-induced inflammatory response. Thus, we examined the inhibitory effect of SML ether fraction on LPS-induced increase of inflammatory mediators(NO, iNOS, COX-2, and $I{\kappa}B{\alpha}$) and pro-inflammatory cytokines(TNF-${\alpha}$) in RAW 264.7 cells. In the present study, SML ether extract itself decreased cell viability in a dose dependent manner(> 100 ${\mu}g/ml$). In addition, LPS increased NO production, iNOS expression and phosphorylation of $I{\kappa}-B{\alpha}$, which were blocked by the treatment of SML ether fraction in a dose dependent manner. Furthermore, the treatment of LPS increased TNF-${\alpha}$ production. However, the pretreatment of SML ether fraction prevented the LPS-induced TNF-${\alpha}$ production in dose dependant manner. Taken together, our results suggest that SML may be a beneficial drug against inflammatory diseases such as sepsis.

• Toxicological Research
• /
• 제26권3호
• /
• pp.217-222
• /
• 2010

Many studies have reported that bleomycin, anti-cancer drug, induces pulmonary fibrosis as a side effect. However, few investigations have focused on the dose-response effects of bleomycin on pulmonary fibrosis. Therefore, in the present study, we investigated the effects of different doses of bleomycin in male mice. ICR mice were given 3 consecutive doses of bleomycin: 1, 2, or 4 mg/kg in bleomycin-treated (BT) groups and saline only in vehicle control (VC) groups. The animals were sacrificed at 7 and 24 days postinstillation. The severity of pulmonary fibrosis was evaluated according to inflammatory cell count and lactate dehydrogenase (LDH) activity in the broncho alveolar lavage fluid (BALF), and lung tissues were histologically evaluated after hematoxylin and eosin (H&E), and Masson's trichrome staining. BT groups exhibited changed cellular profiles in BAL fluid compared to the VC group, which had an increased number of total cells, neutrophils, and lymphocytes and a modest increase in the number of macrophages at 7 days post-bleomycin instillation. Moreover, BT groups showed a dose-dependent increase in LDH levels and inflammatory cell counts. However, at 24 days after treatment, collagen deposition, interstitial thickening, and granulomatous lesions were observed in the alveolar spaces in addition to a decrease in inflammatory cells. These results indicate that pulmonary fibrosis induced by 4 mg/kg bleomycin was more severe than that induced by 1 or 2 mg/kg. These data will be utilized in experimental animal models and as basic data to evaluate therapeutic candidates through non-invasive monitoring using the pulmonary fibrosis mouse model established in this study.

• Food Science and Biotechnology
• /
• 제15권2호
• /
• pp.270-276
• /
• 2006

We evaluated the effects of extracts of Tsunokaori tangor peel on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ in RAW 264.7 cells. The ethyl acetate fraction of Tsunokaori tangor peel (EA-TTP) markedly inhibited the production of NO and $PGE_2$ in LPS-stimulated RAW 264.7 cells. Consistent with these findings, the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins were down-regulated in a dose-dependent manner. Additionally, EA-TTP decreased the expression iNOS mRNA but not COX-2 mRNA. To determine the upstream signaling mechanism for the down-regulation of LPS-induced iNOS expression, we investigated the effect of EA-TTP on the degradation and re-synthesis of $I{\kappa}B{\alpha}$. EA-TTP dose-dependently delayed $I{\kappa}B{\alpha}$ degradation and increased $I{\kappa}B{\alpha}$ re-appearance following degradation, suggesting this as the mechanism by which EA-TTP suppressed iNOS gene expression. The EA-TTP also dose-dependently reduced the expression of the cellular stress-response protein heme oxygenase-1, and inhibited the LPS-induced sustained activation of extracellar signal-regulated kinase (ERK).

• 한국연초학회지
• /
• 제32권1호
• /
• pp.19-27
• /
• 2010

The aim of this study is to compare the sensitivity of both two NCI-H292 and A549 cell types to acute inflammatory responses induced by cigarette smoke. For this, we treated two kinds of smoke fractions derived from 2R4F reference cigarettes: total particulate matter(TPM) collected onto a Cambridge filter pad and gas/vapor phase(GVP) prepared by bubbling through in buffer solution. When we measured cellular cytotoxicity by neutral red uptake assay after treatment for 24 hours, TPM and GVP induced cytotoxic effect in a dose-dependent manner in the range of 10-$100{\mu}g$/mL and 60-$300 {\mu}g$/mL., respectively, in both cell types without any cellular difference. Additionally, when we examined acute inflammatory responses by analyzing cytokines secreted into culture media including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), interleukin-8(IL-8), and transforming growth factor-$\alpha$(TGF-$\alpha$) as well as matrix metalloproteinase-1(MMP-1), the treatment with smoke fractions increased those marker proteins in a dose-dependent manner in NCI-H292. Meanwhile, in A549 cells only MMP-1 was observed to be increased in a dose-dependent fashion. Collectively, our data indicate that NCI-H292 cell type is more sensitive to cigarette smoke-induced inflammatory response than A549 cells. This suggests that NCI-H292 could be useful as an in vitro evaluation tool to assess harmful effects of cigarette smoke.

• Journal of Radiation Protection and Research
• /
• 제28권4호
• /
• pp.327-335
• /
• 2003

The commercially available neutron survey meter, the REM500, which uses a tissue equivalent proportional counter (TEPC) and the self-constructed TEPC were used to determine the microdosimetric quantities of several neutron calibration fields at Korea Atomic Energy Research Institute (KAERI). Microdosimetric spectra, absorbed dose, dose equivalent as well as quality factor were derived and compared with several neutron fields which were produced by using the shadow objects to make neutron scattered and being used as a kind of realistic neutron calibration fields at KAERI. The response of REM500 as a function of mean energy was evaluated with these neutron fields using the counts measured and the predetermined reference value. The response of the self-made TEPC and the REM500 was compared using one of the neutron calibration filelds of a $^{252}Cf$ source. The reference quantities of scattered neutron calibration fields were determined using a Bonner Sphere (BS). The value of frequency-mean lineal energy, dose-mean lineal energy and quality factor of two $^{252}Cf$ sources (unmoderated and $D_2O$ moderated) were determined to check the differences in the reference neutron fields between KAERI and Pacific Northwest National Laboratory (PNNL, USA) and the results were in good agreement within 1%. It means that there is no big difference in dosimetric quantifies of neutron calibration fields of two laboratories.

• Journal of Korean Neurosurgical Society
• /
• 제39권2호
• /
• pp.102-108
• /
• 2006

Objective : The management of diffuse astrocytomas is one of the most controversial areas in clinical neurooncology. There are numerous reviews and editorials outlining the difficulties in the management of these lesions. In this study, we assess the role of Gamma Knife radiosurgery[GKS] for diffuse astrocytomas. Methods : Twenty-three patients with a diffuse astrocytoma were treated with GKS as a primary or adjuvant method from February 1995 to October 2003. The mean marginal dose was $13.6\;[8.5{\sim}17.5]Gy$ and the mean maximal dose was $27.3\;[17.0{\sim}35.0]Gy$. Local control and the pattern of radiologic response were evaluated. The probable factors affecting local control, such as tumor volume, margin dose, previous history of craniotomy or stereotactic biopsy, and the presence or absence of previous radiotherapy were statistically analyzed. The average duration of follow-up was 39.7 [$11.3{\sim}101.5$] months after GKS. Results : Of the 23 lesions treated, 16 lesions [69.6%] were controlled during the follow-up period. The mean progression-free interval was 57.4 months and the 5-year progression-free rate was 68%. Only tumor volume was found to be a statistically significant factor for local control. Smaller tumors were better controlled by GKS; it was significantly effective in tumors with less than $10cm^3$ volume. Conclusion : GKS could be a valuable therapeutic modality both as a primary treatment and as a postoperative adjuvant therapy in some selected cases.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권9호
• /
• pp.5263-5267
• /
• 2013

Background: The aim of this study was to evaluate the efficacy and tolerability of a gemcitabine, 5-fluorouracil and leucovorin (GEMFUFOL) chemotherapy regimen as first line treatment of metastatic biliary tract cancer. Materials and Methods: All patients received folinic acid $400mg/m^2$ on day 1, 5-fluorouracil bolus $400mg/m^2$ on day 1, IV infusion of 5-fluorouracil $2400mg/m^2$ over 46 hours, and gemcitabine $1250mg/m^2$ on day 1. Results: A total of 29 patients with metastatic biliary tract cancer received GEMFUFOL regimen as the firstline treatment. The mean follow-up was 22.1 months (95%CI, 12.5-31.8). One patient (3.4%) achieved complete response, 5 (17.2%) had partial response, and 4 (13.8%) had stable disease. The median progression-free survival was 3.3 months (95%CI, 2.9-3.7), and the median overall survival was 8.8 months (95%CI, 3.5-14). The 1-year and 2-year survival rates were 58.6% and 30%, respectively. Grade 3 and 4 toxicity included neutropenia in 4 patients (13.7%), thrombocytopenia in 2 (6.8%), anemia2 (6.8%), and alopecia in 1 (3.4%). Two patients (6.8%) developed febrile neutropenia. A dose reduction was achieved in 8 patients (27.6%) while 5 patients had extended-interval dosage (17.2%) for toxicity. Conclusions: The GEMFUFOL chemotherapy regimen was generally efficacious and tolerable as a first-line treatment of metastatic biliary tract cancer.