• Radiation Oncology Journal
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• v.19 no.2
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• pp.163-170
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• 2001

Purpose : The measurement of radiation survival using a clonogenic assay, the established standard, can be difficult and time consuming. In this study, We have used the MTT assay, based on the reduction of a tetrazolium salt to a purple formazan precipitate by living cells, as a substitution for clonogenic assay and have examined the optimal condition for performing this assay in determination of radiation sensitivity. Materials and Methods : Four human cancer cell lines - PCI-1, SNU-1066, NCI-H630 and RKO cells have been used. For each cell line, a clonogenic assay and a MTT assay using Premix WST-1 solution, which is one of the tetrazolium salts and does not require washing or solubilization of the precipitate were carried out after irradiation of 0, 2, 4, 6, 8, 10 Gy. For clonogenic assay, cells in $25\;cm^2$ flasks were irradiated after overnight incubation and the resultant colonies containing more than 50 cells were scored after culturing the cells for $10\~14$ days. For MTT assay, the relationship between absorbance and cell number, optimal seeding cell number, and optimal timing of assay was determined. Then, MTT assay was performed when the irradiated cells had regained exponential growth or when the non-irradiated cells had undergone four or more doubling times. Results : There was minimal variation in the values gained from these two methods with the standard deviation generally less than $5\%$, and there were no statistically significant differences between two methods according to t-test in low radiation dose (below 6 Gy). The regression analyses showed high linear correlation with the $R^2$ value of $0.975\~0.992$ between data from the two different methods. The optimal cell numbers for MTT assay were found to be dependent on plating efficiency of used cell line. Less than 300 cells/well were appropriate for cells with high plating efficiency (more than $30\%$). For cells with low plating efficiency (less than $30\%$), 500 cells/well or more were appropriate for assay. The optimal time for MTT assay was after 6 doubling times for the results compatible with those of clonogenic assay, at least after 4 doubling times was required for valid results. In consideration of practical limits of assay (12 days, in this study) cells with doubling time more than 3 days were inappropriate for application. Conclusion : In conclusion, it is found that MTT assay can successfully replace clonogenic assay of tested cancer cell lines after irradiation only if MTT assay was undertaken with optimal assay conditions that included plating efficiency of each cell line and doubling time at least.

• Korean Journal of Psychosomatic Medicine
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• v.14 no.2
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• pp.108-115
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• 2006

Objectives : Objectives of this study was to explore the relationships between anger, alexithymia and premenstrual syndrome(PMS). Methods The subjects included 125 women with PMS and 58 women with non-PMS assessed by Daily record of Severity of Problems(DRSP) and Shortened Premestrual Assessment Form(SPAE). Anger level was assessed by anger expression scale. The level of alexithymia was assessed by Toronto alexithymia scale. We compared the scores of anger, alexithymia between PMS group and no-PMS group. Results : The mean scores of anger in(p=0.04), anger total(p=0.01) were significantly higher in women with PMS compared to control subjects. and the mean scores of alexithymia(p=0.04) were also significantly higher in women with PMS compared to control subjects. Conclusions : This study showed that the level of anger and alexithymia could be higher in women with PMS compared to control subjects, and that symptoms of PMS could be associated with anger and alexithymia. therefore, It would be better to consider the level of anger and alexithymia in treating and evaluating women with PMS.

• Development and Reproduction
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• v.10 no.1
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• pp.63-73
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• 2006

This study aimed to find out suitable culture conditions for the differentiation of human amniotic membrane-derived stem cells(HAM) into hepatocyte-like cells. Almost homogenous population of fibroblast-like cells was successfully isolated from the amniotic membrane. In comparison to the non-coated plates and in the absence of insulin/transferrin/selenium(ITS), HAM cultured on the fibronectin-coated plates and in the presence of ITS showed the more intense immunocytochemical staining against the albumin. Addition of both fibroblast growth factor(FGF)-1 and -2 to the differentiation medium gave stronger staining compared to the treatment with FGF-1 or -2 alone. Periodic acid Schiff's base staining of glycogen and morphological turnover of fibroblast-like appearance of HAM into round shape matched the results of immunocytochemical studies. When the efficiency of two-step culture method was examined on the differentiation of HAM into hepatocyte-like cells, all of the results of immunocytochemical staining, periodic acid Schiff's staining and morphological change exhibited effective hepatic differentiation of HAM compared to the continuous culture method. Immunoblot analyses of HAM- conditioned media against the albumin showed that the culture of HAM in the presence of both ITS and fibronectin always gave a stronger staining intensity than those in the absence of them, and that the addition of ether mixture of FGF-4 and either FGF-2 or transforming growth $factor(TGF)-{\alpha}$ to the culture medium significantly enhanced the albumin secretion by HAM. Based on these observations, it is suggested that HAM could differentiate into hepatocyte-like cells under a culture condition consisting of fibronectin and ITS, and addition of FGF-4 with either one of FGF-2 or $TGF-{\alpha}$ could enhance the hepatic differentiation of HAM.

• Pediatric Infection and Vaccine
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• v.23 no.2
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• pp.102-108
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• 2016

Purpose: Kawasaki disease (KD) shows a variety of clinical signs of multi-system involvement, including clinical diagnostic criteria. It is unknown that the severity of the clinical signs is associated with the risk of coronary artery lesions (CALs). We wanted to evaluate clinical characteristics and the risk of CALs in the patient groups who had severe skin lesions or those with arthritis. Methods: We retrospectively reviewed the medical records of 220 KD patients who were treated with intravenous immunoglobulin (IVIG). We compared clinical and laboratory data between the group with severe skin lesions (n=52) and those with mild or no skin lesions (n=168), and between the group with arthritis (n=6) and those without arthritis (n=214). Results: The mean age of total patients was $2.23{\pm}1.87years$ of age, and the male-to-female ratio was 1.5:1 (138/82). Among 220 patients, 52 patients had CALs (23.6%), and 29 patients (13.2%) showed incomplete KD. The patients with CALs had a higher mean age, longer total fever duration, and higher rate of IVIG non-responsiveness. The patient group with severe skin lesions showed a higher mean age (P<0.001), more prolonged fever duration (P=0.041), higher frequency of CALs (P=0.033), higher WBC, neutrophil, and neutrophil-to-lymphocyte ratio levels, compared to the patient group without severe skin lesions. The patients with arthritis had a tendency of further treatment with methylprednisolone or infliximab. Conclusions: The frequency of CALs was higher in patient group with severe skin lesions. Our results suggest that the intensity of clinical signs of KD such as skin rash, cervical lymphadenopathy and possibly arthritis may be associated the risk of CALs.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.43-47
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• 2009

Purpose: The menstrual cycle of normal premenopausal patients was divide into menstrual flow phase, proliferative phase, ovulatory phase, secretory phase. The aim of this study was to ovarian and endometrial $^{18}F$-FDG uptake during the menstrual cycle in normal premenopausal patients. Materials and Methods: We identified 200 incidental $^{18}F$-FDG uptake in the ovary. The patient fasted at least 6 hours before receiving an intravenous injection of 370-592 MBq (10-16mCi) of $^{18}F$-FDG. Scanning from the base of the skull though the mid thigh was performed using the Discovery Ste PET/CT system (GE Healthcare, Milwaukee, WI, USA). Ovarian and endometrial $^{18}F$-FDG uptake (expressed as standardized uptake value) was measured on PET/CT image. Results: Two peaks of increased endometrial $^{18}F$-FDG uptake were identified during the menstrual cycle. The $SUV_{avg}$ and $SUV_{max}$ was $2.89{\pm}1.04$ and $3.17{\pm}1.59$ in menstruating patients, $2.4{\pm}0.88$ and $2.98{\pm}1.14$ in proliferative phase patients, $3.59{\pm}1.76$ and $3.17{\pm}1.67$ in ovulatory phase patients, $2.58{\pm}1.39$ and $3.1{\pm}1.8$ in secretory phase patients. Conclusions: Increased ovarian and endometrial $^{18}F$-FDG uptake could be found the time of menstrual flow and ovulatory phase of menstrual cycle. Increased uptake in endometrial adjacent to a cervical tumor does not necessarily reflect endometrial tumor invasion. Since increased uptake was dependent on the menstrual cycle, it can be avoided by scheduling PET/CT just after menstruation. Non-menstrual-related endometrial uptake may be instrumental in establishing a diagnosis in a premenopaual patient.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.13-22
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• 2005

It has been known that pulsatile flow is physiologic and more favorable to tissue perfusion than nonpulsatile flow. The purpose of this study is to directly compare the effect of pulsatile versus nonpulsatile blood flow to renal tissue perfusion in extracorporeal circulation by using a tissue perfusion measurement system. Material and Method: Total cardiopulmonary bypass circuit was constructed to twelve Yorkshire swines, weighing 20$\~ $30 kg. Animals were randomly assigned to group 1 (n=6, non pulsatile centrifugal pump) or group 2 (n=6, pulsatile T-PLS pump). A probe of the tissue perfusion measurement system $(QFlow^{TM}-500)$ was inserted into the renal pa­renchymal tissue. Extracorporeal circulation was maintained for an hour at a pump flow of 2 L/min after aortic cross-clamping. Tissue perfusion flow of the kidney was measured at baseline (before bypass) and every 10 minutes after bypass. Serologic parameters were collected at baseline and 60 minutes after bypass. Result: Baseline parameters were not different between the groups. Renal tissue perfusion flow was substantially higher in the pulsatile group throughout the bypass (ranged 48.5$\~$ 64 in group 1 vs. 65.8$\~$88.3 mL/min/100 g in group 2, p=0.026$\~$ 0.45) The difference was significant at 30 minutes bypass $(47.5{\pm}18.3\;in\;group\;1\;vs.\;83.4{\pm}28.5$ mL/min/100 g in group 2, p=0.026). Serologic parameters including plasma free hemoglobin, blood urea nitrogen, and creatinine showed no differences between the groups at 60 minutes after bypass (p=NS). Conclusion: Pulsatile flow is more beneficial to tissue perfusion of the kidney in short-term extracorporeal circulation. Further study is suggested to observe the effects to other vital organs or long-term significance.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.72-78
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• 2010

Purpose: Too develop a flexible drill device that can be inserted into the shoulder joint so that arthroscopic transosseous suture repair for Bankart lesion is possible. Materials and Methods: We created a device composed of a flexible drill unit and a guide pipe unit. The flexible drill unit was made of flexible multifilament wires (1.2 mm in diameter) that was twisted into one cord so that it can flex in any direction and a drill bit (1.2 mm in diameter) that is attached onto one end of the flexible wire. The guide pipe unit was a 150 mm long metal pipe (2.0 mm in inner diameter and 3.0 mm in outer diameter), with one end bent to 30 degrees. The flexible drill set was inserted into the shoulder joint through the posterior portal of the joint. The guide pipe component was placed onto the medial wall of the glenoid so that the pipe was placed 5 mm posterior to the margin of the anterior glenoid rim. The flexible drill was driven through the glenoid by the power drill so that holes were made in the glenoid. A non- absorbable suture was passed through the hole. Tying of a sliding knot tying was accomplished over the capsule and labrum after making a stitch through the capsule and labrum with a suture hook loaded with suture passer. The same procedures were done at the 2 and 4 O'Clock positions of the glenoid. Results: Five cases with Bankart lesion received arthroscopic transosseous repair with our flexible drill device. There were no intraoperative problems. Neither redislocation nor subluxation was reported at final follow-up. Conclusion: Arthroscopic transosseous suture repair without suture anchors and easy tying of a sliding knot are possible with a flexible drill set.

• Clinical and Experimental Pediatrics
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• v.46 no.3
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• pp.242-249
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• 2003

Purpose : We studied the relationship between anthracycline cumulative dose and anthracycline cardiotoxicity in childhood cancer and followed up 40 children with anthracycline cardiotoxicity. Methods : A retrospective study was performed in 154 children who received anthracycline chemotherapy between January 1995 to December 2000. Cardiotoxicity was defined when the left ventricular fractional shortening(FS) was below 26%; it was divided into two groups, mild and severe cardiotoxicity, according to the FS. We followed up survivors with cardiotoxicity, and checked their present cardiac function by physical activity, echocardiography, electrocardiography(EKG) and chest X-ray. Results : Of the 154 children treated with anthracyclines, forty(26.0%) were diagnosed as cardiotoxicity. The incidence of cardiotoxicity increased in exponential fashion with increases in the cumulative dose of anthracyclines. There was minimal increase of incidence until a dose of $300mg/m^2$ after which the incidence increased rapidly. After mean $3.8{\pm}1.8year$ follow-up of 23 survivors with cardiotoxicity, FS increased significantly. EKG and chest X-rays were not helpful for the diagnosis of cardiotoxicity because of their low sensitivity and specificity. Conclusion : Although convenient, non-invasive and inexpensive, EKG and chest X-rays were not helpful for the follow-up of anthracycline cardiotoxicity. Almost all survivors with anthracycline cardiotoxicity have improved in both physical activity and echocardiographic findings after discontinuation of anthracyclines.

• Journal of agricultural medicine and community health
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• v.40 no.1
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• pp.21-31
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• 2015

Objective: This study was to evaluate the health-related quality of life (HRQoL) among patients with diabetes in Korea and to compare them with the HRQoL of individuals without diabetes history. Methods: The study subjects were 17,655 adults aged over 19 who participated in the 5th Korea National Health and Nutrition Examination Survey (2010-2012). The EuroQoL-5Dimension was used to evaluate HRQoL. Chi-square test, t-test, ANOVA and multiple regression analysis were performed to test the difference of HRQoL in diabetic subjects and controls. Results: The mobility dimension was the highest reported problem: 36.4% for diabetic subjects. The proportion of any reported problem was significantly high among diabetic subjects compared with two controls in terms of mobility [reference group: diabetic subjects, chronic controls: adjusted odds ratio (aOR)=0.77, 95% confidence interval (95% CI)=0.66-0.91, healthy controls: aOR=0.61, 95% CI=0.50-0.75], self-care [reference group: diabetic subjects, chronic controls: aOR=0.68, 95% CI=0.55-0.83, healthy controls: OR=0.69, 95% CI=0.51-0.94]. and usual activities [reference group: diabetic subjects, chronic controls: aOR=0.85, 95% CI=0.72-0.99, healthy controls: OR=0.79, 95% CI=0.62-0.98]. Also, EQ-5D index were significantly low in subjects with diabetes compared to two controls. Conclusions: Subjects with diabetes had a significantly lower HRQoL compared with two controls. To improve the quality of life of diabetics, it is necessary to study various variables related to the quality of life, and develop and manage various health programs or welfare policies reflecting socio-demographic characteristics and health related features that affect the quality of life.

• KDI Journal of Economic Policy
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• v.12 no.1
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• pp.69-91
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• 1990

A major change in tariff rates was made in January 1989 in Korea. The benchmark tariff rate, which applies to about two thirds of all commodity items, was lowered to 15 percent from 20 percent. In addition, the variation in tariff rates among different types of commodities was reduced. This paper examines the economic impact of the tariff reform using a multisectoral general equilibrium model of the Korean economy which was introduced by Lee and Chang(1988), and by Lee(1988). More specifically, this paper attempts to find the changes in imports, exports, domestic production, consumption, prices, and employment in 31 different sectors of the economy induced by the reform in tariff rates. The policy simulations are made according to three different methods. First, tariff changes in industries are calculated strictly according to the change in legal tariff rates, which tend to over-estimate the size of the tariff reduction given the tariff-drawback system and tariff exemption applied to various import items. Second, tariff changes in industries are obtained by dividing the estimated tariff revenues of each industry by the estimated imports for that industry, which are often called actual tariff rates. According to the first method, the import-weighted average tariff rate is lowered from 15.2% to 10.2%, while the second method changes the average tariff rate from 6.2% to 4.2%. In the third method, the tariff-drawback system is internalized in the model. This paper reports the results of the policy simulation according to all three methods, comparing them with one another. It is argued that the second method yields the most realistic estimate of the changes in macro-economic variables, while the third method is useful in delineating the differences in impact across industries. The findings, according to the second method, show that the tariff reform induces more imports in most sectors. Garments, leather products, and wood products are those industries in which imports increase by more than 5 percent. On the other hand, imports in agricultural, mining and service sectors are least affected. Domestic production increases in all sectors except the following: leather products, non-metalic products, chemicals, paper and paper products, and wood-product industries. The increase in production and employment is largest in export industries, followed by service industries. An impact on macroeconomic variables is also simulated. The tariff reform increases nominal GNP by 0.26 percent, lowers the consumer price index by 0.49 percent, increases employment by 0.24 percent, and worsens the trade balance by 480 million US dollars, through a rise in exports of 540 million US dollars and a rise in imports of 1.02 billion US dollars.