• Journal of the Korean Society of Radiology
• /
• v.12 no.7
• /
• pp.845-852
• /
• 2018

This study aimed to investigate the difference of X-ray exposure by comparing and analyzing absorbed dose according to changes in the number of frames in coronary angiography, also depending whether the zoom mode is FOV enlargement or Zoom Live. Moreover, for appropriate frame selection measures for examination, including the effect of frame change on the image quality, were sought by measuring the noise strength expressed by the standard deviation (SD), the signal to noise ratio (SNR) and contrast to noise ratio (CNR). The study was conducted with an anthropomorphic phantom on an angio-system. The linear relationship between the frame rate and the radiation dose was evident. On the contrary, the indices of image quality (SD, SNR, and CNR) were almost constant irrespective of the number of frames. The difference depending on the zoom mode was not statistically significant for DAP, air kerma, and SD (p > 0.05). However, SNR and CNR were statistically different between FOV enlargement and Zoom Live. In conclusion, since the image quality was not degraded significantly with the decreasing frame rate from 30, 15, to 7.5 f/s and the radiation dose evidently decreases in almost exactly linear proportion to the decreasing frame rate, the number of frames per second needs to be maintained as low as reasonably achievable. As for the dependence on the zooming mode, the Live Zoom mode showed statistically significant improvement in the image quality indices of SNR and CNR and it justifies active use of the Live Zoom mode which enables real-time image enlargment without additional radiation dose.

• Radiation Oncology Journal
• /
• v.29 no.2
• /
• pp.63-70
• /
• 2011

Purpose: To evaluate the extent of pain response and objective response to palliative radiotherapy (RT) for bone metastases from hepatocellular carcinoma according to RT dose. Materials and Methods: From January 2007 to June 2010, palliative RT was conducted for 103 patients (223 sites) with bone metastases from hepatocellular carcinoma. Treatment sites were divided into the high RT dose and low RT dose groups by biologically effective dose (BED) of 39 $Gy_{10}$. Pain responses were evaluated using the numeric rating scale. Pain scores before and after RT were compared and categorized into 'Decreased', 'No change' and 'Increased'. Radiological objective responses were categorized into complete response, partial response, stable disease and progression using modified RECIST (Response Evaluation Criteria In Solid Tumors) criteria; the factors predicting patients' survival were analyzed. Results: The median follow-up period was 6 months (range, 0 to 46 months), and the radiologic responses existed in 67 RT sites (66.3%) and 44 sites (89.8%) in the high and low RT dose group, respectively. A dose-response relationship was found in relation to RT dose (p=0.02). Pain responses were 75% and 65% in the high and low RT dose groups, respectively. However, no statistical difference in pain response was found between the two groups (p=0.24). There were no differences in the toxicity profiles between the high and low RT dose groups. Median survival from the time of bone metastases diagnosis was 11 months (range, 0 to 46 months). The Child-Pugh classification at the time of palliative RT was the only significant predictive factor for patient survival after RT. Median survival time was 14 months under Child-Pugh A and 2 months under Child-Pugh B and C. Conclusion: The rate of radiologic objective response was higher in the high RT dose group. Palliative AT with a high dose would provide an improvement in patient quality of life through enhanced tumor response, especially in patients with proper liver function.

• IMMUNE NETWORK
• /
• v.4 no.4
• /
• pp.244-249
• /
• 2004

Background: Corticotropin-Releasing Hormone (CRH), an important regulator of stress response, has a potent immunoregulatory effect with the ability to promote the growth of various cancer through CRH receptor type 1 under stress. Although the metastasized cancers through cell migration are more aggressive than the primary cancers, little is known about the effect of CRH on cell migration. Gastric cancer is prone to metastasize to other tissues and it is reported that gastric cancer is response to various stresses such as oxidative stress. Herein, we studied the relationship between CRH and gastric cancer cell migration. Methods: We used gastric cancer cell line, MKN-28 and tested the CRH receptor type 1 expression on MKN-28 by RT-PCR. To examine the change in the ability of migration by CRH in MKN-28, cells were incubated with CRH and then migration ability was measured using a cell migration assay. Results: We confirmed that CRH receptor type 1 was expressed in MKN-28 and HaCaT cells. The migration ability of MKN-28 cells was increased by CRH in a time-, dose- dependent manner. Conclusion: These data suggest that CRH increases migration ability in gastric cancer cell line and that CRH may be a critical regulator in the metastasis of gastric cancer cell.

• Toxicological Research
• /
• v.17
• /
• pp.79-82
• /
• 2001

The infection of liver flukes, Clonorchis sinensis (CS) and Opisthorchis viverrini (OV), has been known as a risk factor to induce cholangiocellular carcinoma (CCC) in human living in the endemic area, providing promoting effect on the liver initiated by chemical carcinogens. The present study evaluated the relationship between the dosage level of dimethylnitrosamine (DMN) and the infection load of CS in the neoplastic development by histopathological examination of the treated hamsters. To evaluate the effects of DMN, different doses of DMN ranging from 0 to 25 ppm were administered to hamsters with 20 CS metacercariea. For the risk assessment of the infection load, 0, 5, 15, 50 CS metacercariae were respectively infected with 12 ppm DMN. The mortality was closely related to the infection load rather than the concentration of DMN. The infection of CS clearly promoted the induction of CCC even at dose level of 6 ppm DMN. Only five metacercariae were enough to promote CCC induction at the concentration of 12 ppm DMN.

• Ocean and Polar Research
• /
• v.26 no.3
• /
• pp.475-480
• /
• 2004

Recently, less toxic and more effective anaesthetics are essential for marine fishes. Lidocaine belongs to a group of anaesthetics which are used as local anaesthetic in human medicine. This chemical was tested fer winter flounder, Pleunnectes americanus. Anaesthetic effect of lidocaine hydrochloride-sodium bicarbonate mixture (lidocaine $HCl/NaHCO_3$) was tested for the winter flounder at five different temperature regimes: $3^{\circ}C,\;7^{\circ}C,\;11^{\circ}C,\;15^{\circ}C\;and\;19^{\circ}C$ Anaesthetic dose and temperature-dependent relationship in exposure and recovery time were observed for the winter flounder of $17.2{\pm}0.1cm$ mean total length. Based on the results, anaesthetic lidocaine $HCl/NaHCO_3$ showed rapid exposure time and rapid recovery time for winter flounder. The results indicate that lidocaine $HCl/NaHCO_3$ can be used as suitable anaesthetic for this species.

• Toxicological Research
• /
• v.12 no.1
• /
• pp.21-27
• /
• 1996

Vitamin C has been well known to be a potential chemopreventive agent for several toxic compounds. It reduced the mutation frequencies of 6-sulfooxymethylbenzo[a]pyrene (SMBP) and 6hydroxymethylbenzo[a]pyrene (HMBP) in Salmonella typhimurium TA98 and TA100, indicating that corbic acid affects both frameshift and base-pair substitution mtltations. A similar type of dose-response relationship was shown in the V79 cells, although the inhibitory effect was less dramatic compared with that in S. typhimurium. However, SMBP or HMBP binding to calf thymus DNA was not affected by the presence of vitamin C, suggesting that SMBP seems to be much more reactive to calf thymus DNA than vitamin C. This was supported by migration pattern and fluorescence intensity of SMBP-modified plasmid on the gel. These restilts were not correlated with mutation tests in bacterial and mammalian cell systems. It has been already reported that vitamin C inactivates SMBP through the formation of covalently bound addact. It was found from HPLC analysis that the reaction between vitamin C and SMBP was accomplished within just 5 min and then produced the several products. These findings indicate that the beneficiary of vitamin C is not merely derived from the covalent adducts. On the other hand, the addition of DNA to incubation mixture reduced the amounts of vitamin C adducts while the magnitude of HMBP peak increased, suggesting that DNA accelerates the SMBP hydrolysis to intercept the interaction between SMBP and vitamin C or forms rapidly complex with SMBP.

• Radiation Oncology Journal
• /
• v.18 no.1
• /
• pp.60-67
• /
• 2000

Purpose :To evaluate protective mechanism of melatonin against radiation damage and its relationship with apoptosis in mouse jejunum. Materials and Methods: 168 mice were divided into 28 groups according to radiation dose and matatonin treatment. To analysis crypt survival, microcolony survival assay was done according to Withers and Elkind's method. To analysis apoptosis, TUNEL assay was done according to Labet-Moleur's method. Results : Radiation protection effect of melatonin was demonstrated by crypt survival assay and its effect was stronger in high radiation dose area. Apoptosis index with 8 Gy irradiation was 18.4$\%$ in control group and 16.5$\%$ in melatonin treated group. After 18 Gy, apoptosis index was 17.2$\%$ in control group and 15.4$\%$ in melatonin treated group. Apoptosis index did not show statistically significant difference between melatonin treated group and control group. Conclusion : Melatonin shows clear protective effect in mouse jejunum against radiation damage but its protective effect seems not to be related with apoptosis protection effect.

• Radiation Oncology Journal
• /
• v.13 no.2
• /
• pp.113-120
• /
• 1995

Purpose : To investigate the effect of alkaloid fraction from Korean ginseng on radiation-induced DNA double strand breaks (dsb) formation and repair in murine lymphocytes Materials and Methods : We used the neutral filter elution technique to assay $^{60}Co\;{\gamma}$ ray-induced DNA double strand breaks formation and repair in C57BL/6 mouse spleen lymphocytes for evaluating the dose-response relationship in the presence of alkaloid fraction as a radioprotective agent. The lymphocytes were stimulated with Phytohemagglutinin (PHA, 2 u g/ml) to label $^3[H]-thymidine.$ Isotope-labelled lymphocytes in suspension were exposed to 100 Gy at $0^{\cdot}C$ in the alkaloid fraction-treated group and elution procedure was performed at PH 9.6. The extents of formation of radiation-induced DNA double strand breaks and repair were compared respectively via strand scission factor (SSF) and relative strand scission factor (RSSF). Results: Alkaloid fraction reduced the formation of double strand breaks with dose modification factor of 2 15, compared to control group Rejoining of DNA dsb appeared to take place via two components. The first fast component was completed within 20.4 minutes, but the second slow component was not completed until 220.2 minutes after irradiation. About $30\%$ of dsb formed by irradiation was ultimately unrejoined despite the administration of alkaloid fraction. The administration of alkaloid fraction had a great effect on the second slow component of repair; the half-time of fast component repair was not changed, but that of slow component was 621.8 minutes. Conclusion: Neutral filter elution assay Proved to be a very effective method to quantitate the extents of DNA dsb formation and its repair. By using this technique, we were able to evaluate the efficiency of alkaloid fraction from Korean ginseng as a valuable radioprotector. Alkaloid fraction can be used prophylactically to prevent or ameliorate the severe radiation damages in workers and neighbors around the atomic power plants. For more refined study, however, more advanced purification of alkaloid fraction wil be needed in the near future.

• Korean Journal of Veterinary Research
• /
• v.34 no.3
• /
• pp.559-567
• /
• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, and a delicate relationship between host and parasite, in the present studies, SPF ICR mice were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,100 embryonated A suum eggs. In normal group, the infection essentially terminates 4 days after inoculation(DAI) with the attainment of middle third-stage in the liver, although few larvae migrate to the lungs where a few advance to late third stage. In immunosuppressive group, significant numbers developed to late third-stage in liver 8 DAI. In general, increasing of the mast cells and the goblet cells in the jejunum mucosa, of T-cells in the spleen and of activity of peritoneal macrophages followed by expulsion of the worms in the both groups. Considering a series of the results, suitabilities for the host of the worm appeared the highest from rabbit, hamster and mouse in that order. In addition, patent infection of A suum in the mice was also not obviously observed in spite of immunosuppression by prednisolone acetate.

• Korean Journal of Veterinary Research
• /
• v.34 no.1
• /
• pp.127-134
• /
• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, a delicate relationship between host and parasite, in the present studies golden hamsters were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,500 embryonated Ascaris suum eggs. The recovery rates, sizes and features of the larvae and immunological responses in the hamsters were chronologically monitored according to somatic migration. In both experiments, the larvae failed to develop into the adults, but the more and larger larvae were observed for a longer period from experiment 2 in comparison with experiment 1. The numbers of the mast cells in the small intestinal mucosa and mesenteric lymph nodes, of the goblet cells in the small intestinal mucosa and of T-cells in the mesenteric lymph nodes, spleens and cardiac blood from experiment 2 were fewer than those from the experiment 1. In general, increasing of these cells followed by expulsion of the worms in the both groups. Profound leukopenia due to lymphopenia was found through trial period in experiment 2. Considering the experimental results, development or expulsion mechanism of somatic migrant larvae may be related to lymphopenia and temporary increasing tendency of the mast cells, the goblet cells and T-cells. In addition, patent infection of A suum in the hamsters was not obviously observed in spite of immunosuppression by prednisolone acetate.