• Korean Circulation Journal
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• v.52 no.7
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• pp.544-555
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• 2022

Background and Objectives: The outcome benefits of β-blockers in chronic coronary artery disease (CAD) have not been fully assessed. We evaluated the prognostic impact of β-blockers on patients with chronic CAD after percutaneous coronary intervention (PCI). Methods: A total of 3,075 patients with chronic CAD were included from the Grand Drug-Eluting Stent registry. We analyzed β-blocker prescriptions, including doses and types, in each patient at 3-month intervals from discharge. After propensity score matching, 1,170 pairs of patients (β-blockers vs. no β-blockers) were derived. Primary outcome was defined as a composite endpoint of all-cause death and myocardial infarction (MI). We further analyzed the outcome benefits of different doses (low-, medium-, and high-dose) and types (conventional or vasodilating) of β-blockers. Results: During a median (interquartile range) follow-up of 3.1 (3.0-3.1) years, 134 (5.7%) patients experienced primary outcome. Overall, β-blockers demonstrated no significant benefit in primary outcome (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.63-1.24), all-cause death (HR, 0.87; 95% CI, 0.60-1.25), and MI (HR, 1.25; 95% CI, 0.49-3.15). In subgroup analysis, β-blockers were associated with a lower risk of all-cause death in patients with previous MI and/or revascularization (HR, 0.38; 95% CI, 0.14-0.99) (p for interaction=0.045). No significant associations were found for the clinical outcomes with different doses and types of β-blockers. Conclusions: Overall, β-blocker therapy was not associated with better clinical outcomes in patients with chronic CAD undergoing PCI. Limited mortality benefit of β-blockers may exist for patients with previous MI and/or revascularization.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.249-256
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• 1999

This study was performed to investigate the changes in flow and composition of saliva in oral cancer patients after radiation therapy. Stimulated whole saliva was collected from 7 patients who were scheduled for over 6,000cGy irradiation (180 - 225cGy fraction $Co^{60}$ therapy, 5 times a week). The flow rate of saliva, and concentration of total protein and IgA were measured before irradiation and 1, 2, 3, 4, 5 days and 1, 2, 3, 4, 6 weeks and 3, 6, 12 months after. The followings are results we obtained: 1. The salivary flow rate before irradiation was $0.8671{\pm}0.4057ml/min$. Significant decrease started 3 days after irradiation and reached a minimum at 4 weeks ($0.2621{\pm}0.2858ml/min$). Afterwards, flow rate started to increase and was on the way to recover at 1 year. 2. The concentration of total protein and IgA before irradiation were $137.2000{\pm}16.9912mg%$ and $3.4200{\pm}1.4114mg%$, respectively. After irradiation, these figures increased significantly and reached a maximum of $366.4000{\pm}174.0583mg%$ and $43.4800{\pm}29.1207mg/ml$, respectively at 6 weeks. Recovery towards normal values started following the end of irradiation and figures at 12 months had lowered to $165.400{\pm}21.1495mg%$ and $4.6200{\pm}2.1580mg/ml$ each. 3. The ratio of IgA to the amount of total protein was 2.5% before irradiation. This began to increase from 1 week following irradiation as the total dose of radiation received was increased (11.9% at 6 weeks). After 1 year from the start of radiation therapy, the ratio was reduced to such level that was before irradiation.

• Progress in Medical Physics
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• v.11 no.2
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• pp.157-165
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• 2000

Purpose: For estimation of yields of l)NA damages induced by radiation and enhanced by oxygen, a mathematical model was used and tested. Materials and Methods: Reactions of the products of water radiolysis were modeled as an ordinary time dependant equations. These reactions include formation of radicals, DNA damage, damage repair, restitution, and damage fixation by oxygen and H-radical. Several rate constants were obtained from literature while others were calculated by fitting an experimental data. Sensitivity studies were performed changing the chemical rate constant at a constant oxygen number density and varying the oxygen concentration. The effects of oxygen concentration as well as the damage fixation mechanism by oxygen were investigated. Oxygen enhancement ratio(OER) was calculated to compare the simulated data with experimental data. Results: Sensitivity studies with oxygen showed that DNA survival was a function of both oxygen concentration and the magnitude of chemical rate constants. There were no change in survival fraction as a function of dose while the oxygen concentration change from 0 to 1.0 x 10$^{7}$ . When the oxygen concentration change from 1.0 $\times$ 107 to 1.0 $\times$ 101o, there was significant decrease in cell survival. The OER values obtained from the simulation study were 2.32 at 10% cell survival level and 1.9 at 45% cell survival level. Conclusion: Sensitivity studies with oxygen demonstrated that the experimental data were reproduced with the effects being enhanced for the cases where the oxygen rate constants are largest and the oxygen concentration is increased. OER values obtained from the simulation study showed good agreement for a low level of cell survival. This indicated that the use of the semi-empirical model could predict the effect of oxygen in cell killing.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.1
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• pp.40-47
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• 2006

Purpose: The aim of this study was to examine the effects of attenuation correction (AC) and scatter correction (SC) on the quantification of PET count rates. Materials and Methods: To assess the effects of AC and SC $^{18}F$-FDG PET images of phantom and cat brain were acquired using microPET R4 scanner. Thirty-minute transmission images using $^{68}Ge$ source and emission images after injection of FDG were acquired. PET images were reconstructed using 2D OSEM. AC and SC were applied. Regional count rates were measured using ROIs drawn on cerebral cortex including frontal, parietal, and latral temporal lobes and deep gray matter including head of caudate nucleus, putamen and thalamus for pre- and post-AC and SC images. The count rates were then normalized with the injected dose per body weight. To assess the effects of AC, count ratio of "deep gray matter/cerebral cortex" was calculated. To assess the effects of SC, ROIs were also drawn on the gray matter (GM) and white matter (WM), and contrast between them ((GM-WM)/GM was measured. Results: After the AC, count ratio of "deep gray matter/cerebral cortex" was increased by $17{\pm}7%$. After the SC, contrast was also increased by $12{\pm}3%$. Conclusion: Relative count of deep gray matter and contrast between gray and white matters were increased after AC and SC, suggesting that the AC would be critical for the quantitative analysis of cat brain PET data.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.34-37
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• 2012

Purpose: To verify the optimal scan time per bed for clinical application, we evaluated the quality of $^{18}F$-FDG images with varying scan times in a phantom and 20 patients with 38 lesions using a Philips (TOF) PET/CT scanner. Materials and Methods: The PET/CT images of a NEMA IEC body phantom and 20 patients (16 males, 4 females) were acquired for 5 different scan times of 20-100 sec per bed with intervals of 20 sec. The activity ratio of hot spheres (diameter of 17 [H1], 22 [H2] and 28 [H3] mm) to the background region in the IEC body phantom was 8-to-1. The contrast recovery coefficient (CRC) and standard uptake value (SUV) based on ROIs of hot spheres and background region were calculated. The noise in each background region was estimated as the ratio of SD of counts to the mean counts in the background region. On the patient image, the injected dose of $^{18}F$-FDG was $444{\pm}74$ MBq and the SUVs in the 38 hot lesions were measured. Results: The two scan time groups (LT-60 [<60 sec] and GT-60 [${\geq}60$ sec]) were compared. In the phantom study, the coefficient of deviations (CVs, %) of CRC and SUV in LT-60 (H1: 14.2 and 7.3, H2: 11.4 and 7.8, H3: 4.9 and 3.2) were higher than GT-60 (H1: 8.9 and 2.8, H1: 8.2 and 5.0, H3: 2.0 and 1.6). In the patient study, the mean CV of CRC and SUV in LT-60 (4.0) was higher than GT-60 (1.2). Conclusion: This study showed that noise increased as the scan time decreased. High noise for the scan time <60 sec per bed yielded high variation of SUV and CRC. Therefore, considering PET/CT image quality, the scan time per bed in the TOF PET/CT scanner should be at least ${\geq}60$ sec.

• The Korean Journal of Nuclear Medicine
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• v.33 no.3
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• pp.289-297
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• 1999

Purpose: Misonidazole is a radiosensitizer that binds in hypoxic cells. The purpose of this study was to find out the feasibility of I-131-Iodomisonidazole (IMISO) for imaging of tumor hypoxia. Materials and Methods: Tosyl precursor was dissolved in acetonitrile and I-131-NaI was added to synthesize IMISO. Balb/c mice inoculated with CT-26 adenocarcinoma were injected with IMISO. Mice were sacrificed at 1, 2, 4, 24 hr and % of injected dose per gram of tissue (%ID/g) was determined. For scintigraphy and MRI, mouse bearing CT-26 adenocarcinoma was administered with IMISO and imaging was performed 4 hr after. Then, mouse body was fixed and microtomized slice was placed on radiographic film for autoradiography Results: %ID/g of tumor was 1.64 (1h), 0.98 (2h), 0.85 (4h) and 0.20 (24h), respectively. At 24h, %ID/g of tumor was higher than that of all other tissues except thyroid. Tumor to muscle ratio increased with time and tumor to blood ratio also increased with time and reached 1.53 at 24 hr. On autoradiogram, tumor was well visualized as an increased activity in central hypoxic area of the tumor which corresponds to the area of high signal intensity on T2-weighted MR image. On scintigraphy, tumor uptake was visualized. Conclusion: This results suggest that IMISO may have a potential for tumor hypoxia imaging in mouse model. However, further study is needed to improve it's localization in tumor tissue and to achieve acceptable images of tumor hypoxia.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.25-32
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• 2013

The purpose of this study was to investigate the effects of mustard, which contains allyl isothiocyanate, on ruminal fermentation and methane emission in vitro. To this end, diluted ruminal fluid(30ml) was incubated anaerobically at $39^{\circ}C$ or 6, 12, and 24 h with or without seeds or powdered mustard. Either mustard seed or powdered mustard was weighed and serially (0, 3.33, 5.00, 6.67, and 8.33 g/L) mixed with ruminal fluid. Ammonia-N was increased (P < 0.05) by mustard treatment in a dose dependent manner. Regardless of concentration or form, mustard increased (P < 0.05) total VFA content but decreased (P < 0.01) pH compared to control group. Molar proportion of acetate (A) was decreased (P < 0.05) whereas propionate (P) was increased (P < 0.05) by mustard treatment, thereby A:P ratio was decreased (P < 0.05) compared to control group. Total gas production was increased (P < 0.01) in a linear manner by mustard treatment compared to control group. There was no effect of mustard powder, except 8.33 g/L level at 6 h, on methane emission. However, at 24 h, methane emission was reduced (P < 0.05) by 4.77% and 11.54% with 6.67 g/L and 8.33 g/L of mustard seeds supplementation, respectively. Altogether, these results suggest that mustard seeds containing allyl isothiocyanate may reduce methane production without disturbing ruminal fermentation.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.673-678
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• 2009

High-rate phosphorous removal by PAC (poly aluminum chloride) coagulation of A2O effluent was investigate to meet the stringent requirement of wastewater discharge from municipal wastewater treatment plant. A series of jar tests were conducted to find optimum coagulation condition and to enhance removal efficiency. The optimum volumetric concentration of PAC was 30 ppm (2.81mol Al/mol P by mol ratio). Only 17.2% of soluble P was removed for 30 minutes' settling without PAC addition, while this increased to 30.3% by dosing 10ppm PAC. It even increased conspicuously from 49.3% to 88.4% by increasing PAC dose from 20 ppm to 30 ppm. 92.4% of total P was removed by 30 ppm PAC, and the effluent concentration (0.3 mg/L) was acceptable for discharge. The optimum value of coagulation time, settling time, and pH were 4minutes, 20 minutes, and 7.0, respectively. It was not necessary to control pH of raw sample whose pH was 7.0. Soluble P removal was remarkably enhanced at pH 7.0. This implied that sweep floc formation by $Al(OH)_3$ was the main mechanism of coagulation for soluble P removal. Influent and effluent of secondary clarifier were tested for coagulation, and the effluent was better for high-rate P removal. It resulted in 0.18 mg/L of P and 95.4% of P removal by coagulation. It was favorable to recycle the treated water to coagulation tank and the optimum recycle ratio was 0.3.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.29-38
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• 1998

In order to elucidate the effect of phenobarbital sodium(PB) and 3-methylcholanthrene(3-MC) on metabolism in vitro and toxicity of $^{14}C$-carbofuran in rat, they were administered by the chemicals, alone or in combination, and their survival ratios and metabolites were investigated. The $LD_{50}$(96 hrs) value of carbofuran to rats was 6.9 mg/kg. The toxicities of the major metabolites were in the decreasing order of 3-hydroxycarbofuran, 3-ketocarbofuran, 3-hydroxycarbofuran phenol and were much lower than that of the parent compound. When the rats were orally administered by the dose of carbofuran alone, 8.4 mg/kg, the survival ratio was 0%, whereas that was raised up to $60{\sim}80%$ with 20 mg/kg of PB or 3-MC, and 100% with 60 mg/kg of PB or 3-MC. Their metabolism in vitro occurred in the microsomal fraction. In case of carbofuran alone, the major metabolite was 3-hydroxycarbofuran. When carbofuran with PB or 3-MC, on the other hand, was treated, it was 3-ketocarbofuran. In addition, when the co-factor(NADP+G-6-P+G-6-P-DG) was added to the microsomal fraction(phase I system), and a mixture of NADPH+GSH to the 105,000g supernatant(phase II system) taken by carbofuran alone, each metabolites were produced by the maximum levels, respectively. In case of the carbofuran treatment with PB or 3-MC, the microsomal fraction of phase I system produced the maximum levels of metabolites, as in the treatment of carbofuran alone, whereas the 105,000g supernatant supplemented with the co-factor NADPH+FAD(phase II system) was brought about the maximum production of metabolites. The ratio of the formation of metabolites was 2 to 3 times higher in the combined treatment of carbofuran with PB or 3-MC than in the treatment of carbofuran alone.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.123-158
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• 2009

An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.