• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.135-152
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• 1983

Emergency medical service is an important part of the health care delivery system, and the optimal allocation of resources and their efficient utilization are essentially demanded. Since these conditions are the prerequisite to prompt treatment which, in turn, will be crucial for life saving and in reducing the undesirable sequelae of the event. This study, taking the hyperbaric chamber for carbon monoxide poisoning as an example, is to develop a stochastic approach for solving the problems of optimal allocation of such emergency medical facility in Korea. The hyperbaric chamber, in Korea, is used almost exclusively for the treatment of acute carbon monoxide poisoning, most of which occur at home, since the coal briquette is used as domestic fuel by 69.6 per cent of the Korean population. The annual incidence rate of the comatous and fatal carbon monoxide poisoning is estimated at 45.5 per 10,000 of coal briquette-using population. It offers a serious public health problem and occupies a large portion of the emergency outpatients, especially in the winter season. The requirement of hyperbaric chambers can be calculated by setting the level of the annual queueing rate, which is here defined as the proportion of the annual number of the queued patients among the annual number of the total patients. The rate is determined by the size of the coal briquette-using population which generate a certain number of carbon monoxide poisoning patients in terms of the annual incidence rate, and the number of hyperbaric chambers per hospital to which the patients are sent, assuming that there is no referral of the patients among hospitals. The queueing occurs due to the conflicting events of the 'arrival' of the patients and the 'service' of the hyperbaric chambers. Here, we can assume that the length of the service time of hyperbaric chambers is fixed at sixty minutes, and the service discipline is based on 'first come, first served'. The arrival pattern of the carbon monoxide poisoning is relatively unique, because it usually occurs while the people are in bed. Diurnal variation of the carbon monoxide poisoning can hardly be formulated mathematically, so empirical cumulative distribution of the probability of the hourly arrival of the patients was used for Monte Carlo simulation to calculate the probability of queueing by the number of the patients per day, for the cases of one, two or three hyperbaric chambers assumed to be available per hospital. Incidence of the carbon monoxide poisoning also has strong seasonal variation, because of the four distinctive seasons in Korea. So the number of the patients per day could not be assumed to be distributed according to the Poisson distribution. Testing the fitness of various distributions of rare event, it turned out to be that the daily distribution of the carbon monoxide poisoning fits well to the Polya-Eggenberger distribution. With this model, we could forecast the number of the poisonings per day by the size of the coal-briquette using population. By combining the probability of queueing by the number of patients per day, and the probability of the number of patients per day in a year, we can estimate the number of the queued patients and the number of the patients in a year by the number of hyperbaric chamber per hospital and by the size of coal briquette-using population. Setting 5 per cent as the annual queueing rate, the required number of hyperbaric chambers was calculated for each province and for the whole country, in the cases of 25, 50, 75 and 100 per cent of the treatment rate which stand for the rate of the patients treated by hyperbaric chamber among the patients who are to be treated. Findings of the study were as follows. 1. Probability of the number of patients per day follows Polya-Eggenberger distribution. $$P(X=\gamma)=\frac{\Pi\limits_{k=1}^\gamma[m+(K-1)\times10.86]}{\gamma!}\times11.86^{-{(\frac{m}{10.86}+\gamma)}}$$ when$${\gamma}=1,2,...,n$$$$P(X=0)=11.86^{-(m/10.86)}$$ when $${\gamma}=0$$ Hourly arrival pattern of the patients turned out to be bimodal, the large peak was observed in $7 : 00{\sim}8 : 00$ a.m., and the small peak in $11 : 00{\sim}12 : 00$ p.m. 2. In the cases of only one or two hyperbaric chambers installed per hospital, the annual queueing rate will be at the level of more than 5 per cent. Only in case of three chambers, however, the rate will reach 5 per cent when the average number of the patients per day is 0.481. 3. According to the results above, a hospital equipped with three hyperbaric chambers will be able to serve 166,485, 83,242, 55,495 and 41,620 of population, when the treatmet rate are 25, 50, 75 and 100 per cent. 4. The required number of hyperbaric chambers are estimated at 483, 963, 1,441 and 1,923 when the treatment rate are taken as 25, 50, 75 and 100 per cent. Therefore, the shortage are respectively turned out to be 312, 791. 1,270 and 1,752. The author believes that the methodology developed in this study will also be applicable to the problems of resource allocation for the other kinds of the emergency medical facilities.

• Journal of Preventive Medicine and Public Health
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• v.35 no.2
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• pp.129-135
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• 2002

Objective : The primary objective of this study was to estimate the prevalence of HBsAg-positives in the late 1990's among Korean adults. In addition, we evaluated the association of age, a residential area, a vaccination rate, a family history of chronic liver diseases and a past history of acute liver disease with the seropositivity of HBsAg, and estimated the prevalence of chronic HBV infection by follow-up for 6 month or more. Methods : A total of 10 areas, six metropolitan and four small cities, were selected. In each cities, one health screening center was selected for recruitment of study subjects. The study subjects were enrolled from a general health examination program that is provided by medical insurance companies. Questionnaires on various risk factors were administered to the study subjects. Sera was drawn and tested for HBsAg by radioimmunoassay. HBeAg and ALT were also tested for those of HBsAg positive. The HBsAg positives was retest for HBsAg 6 months later Results : Among the study subjects (n= 1816), the seroprevalence of HBsAg was 5.5% (95% CI=4.5%-6.6%), 7.4% in men (95% CI=5.8-9.4) and 3.6% in women (95% CI=2.5-5.0). A past history of acute liver disease and a family history of chronic liver diseases was shown to be risk factors for HBsAg positivity. Among the 31 HBsAg-positives, negative seroconversion rate was estimated to be 3.2%, Thus, prevalence of chronic HBV infection was estimated to be 5.3% (95% CI=3.7-6.6). Conclusion : In this study, the HBsAg seroprevalence rate was lower than that of the other studies in 1980's, particularly in young adult and women. Considering the public health importance of liver cancer and chronic liver diseases, the further effort is needed to prevent and reduce the HBV infection.

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.845-862
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• 1995

We followed prospectively some hospital-delivered mothers to identify characteristics of those not initiated breast-feeding and predictors of breast-feeding discontinuation in monthly telephone interviews. Recruits were composed of 482 mothers who delivered their babies at one university hospital and one OB/GYN clinic in September to November 1991. Breast-feeding discontinuation was defined as switch to 100% formula lasting more than one week regardless of solid foods. Average age of the study subjects was 27.3 years of age(standard deviation 3.2). Multiple logistic regression analysis indicated native place, occupation, method of delivery and method of feeding considered to be better for maternal health were statistically significant(p<0.1) between initiators and non-initiators of breast feeding. In starting cohort(N=242) of those initiated breast-feeding, that median of breast-feeding discontinuation were 5 months and 25th and 75th percentiles were 3 and 9 months respectively. In Cox's proportional hazard model, mothers with $10\sim13$ years of education were 2.63 times (95% confidence interval, CI $1.50\sim4.60$) more likely to discontinue than those with less than 9 years of education and those with more than 13 years of education were 3.55 time (95% CI $1.99\sim6.33$). Compared with house wife, mothers with part-time jobs were 1.99 times (95% CI $0.86\sim4.57$) more likely to discontinue and those with employed full-time were 1.55 times (95% CI $0.96\sim2.51$). These results suggest that the predictors of initiation and discontinuation of breast-feeding may be different and different target populations should be selected to promote initiation and to prevent discontinuation of breast-feeding according to the period after birth.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.150-156
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• 2003

Purpose : Efforts to predict the clinicopathological outcome of IgA nephropathy have been made but have yielded conflicting results and have not helped in deciding the appropriate timing of the renal biopsy. In this study, we reviewed the predictive factors of clinicopathological outcome for finding out the criteria of renal biopsy timing of IgA nephropathy. Methods : Forty children diagnosed with biopsy proven IgA nephropathy at Wonju Christian Hospital were studied retrospectively, based on medical records. Results : Among 39 patients, 2 children progressed to higher serum creatinine level. One of them reached to the end stage renal disease within 2 year 7 months. According to WHO histopathological classification, there were 15 cases of class I, 14 cases of class II, 7 cases of class III, and 3 cases of class IV. In the mild histological classes(class I, II), gross hematuria was shown in 23 out of 29 children(P=0.02). In the severe histological classes(class III, IV), gross hematuria was noted in 4 out of 10(P>0.05). The tubulointerstitial changes were grade 1 in 24 cases, grade 2 in 4 cases, grade 3 in 8 cases, and grade 4 in 3 cases. With an increase in the tubulointerstitial grade, the 24 hour urine protein/albumin ratio increased. Serum creatinine less than 0.79 mg/dL could predict the lower grade(grade 1 and 2) of tubulointerstitial changes. But serum creatinine greater than 1.13 mg/dL could predict the higher grade(grade 3 and 4) of tubulointerstitial changes. In children with gross hematuria(n=27), serum creatinine was lower(0.78 vs 1.09 mg/dL, P=0.027), serum IgA was higher(316.3 vs 198.8 mg/dL), and the cases of lower WHO classification(I and II) were more common(23 vs 4, P=0.029) than the children with microscopic hematuria. Conclusion : Serum creatinine less than 0.79 mg/dL, macroscopic hematuria, and higher 24 hour urine protein/albumin ratio would predict the lower grade glomerulo tubulointerstitial lesion in IgA nephropathy and could be used as the criteria delaying the renal biopsy.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.362-367
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• 2007

A total of 5 female elk deer (220 $kg{\pm}10$ kg) were included in a study on the changes in physico-chemical properties of deer meat during storage at $4^{\circ}C$. The deers were exposed to normal pre-slaughter handling and put under anesthesia before slaughtered. The loin and leg cuts were deboned from the carcass after 24hrs slaughter. The samples weighing approximately 300 g were packaged using three packaging methods : Atmospheric packaging(A), Vacuum packaging (V) and Modified atmospheric at packaging (M: 80% $CO_2$ +20% $N_2$)and stored for 3, 7, 11, 15, 20 and 25days at $4^{\circ}$. The ability of moisture maintenance tended to be decreased with the passage of storage time, and that of the meats treated with the vacuum wrapping was lower than that with other wrapping methods. TBARS values of the meats with the regardless of treatments was increased with the passage of storage time, although the values with vacuum wrapping was lowest. VBN values of the meats with the regardless of treatments was also increased with the passage of storage time, although the values with vacuum wrapping was also lowest. The pH values of the meats with the regardless of treatments was also increased with the passage of storage time, although the values with vacuum wrapping was also lowest. For the meat softness, the value of the meats treated with atmospheric packaging was increased with the passage of storage time, but the values with vacuum wrapping and modified atmospheric packaging were respectively decreased. There were no significant differences in luminosity of leg, although loin treated with vacuum wrapping was significantly brighter than that with atmospheric packaging and modified atmospheric packaging. In general, the index of red color of the meats treated with vacuum wrapping was higher than that with atmospheric packaging and modified atmospheric packaging. The index of yellow color tended to be decreased after increment for a time with the passage of storage time, although the value with vacuum wrapping was generally higher than that with other wrapping methods.

• Journal of Life Science
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• v.22 no.3
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• pp.366-372
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• 2012

This study was conducted to estimate the extent of linkage disequilibrium (LD) and effective population size using whole genomic single nucleotide polymorphisms (SNP) genotyped by DNA chip in Hanwoo. Using the blood samples of 35 young bulls born from 2005 to 2008 and their progenies (N=253) in a Hanwoo nucleus population collected from Hanwoo Improvement Center, 51,582 SNPs were genotyped using Bovine SNP50 chips. A total of 40,851 SNPs were used in this study after elimination of SNPs with a missing genotyping rate of over 10 percent and monomorphic SNPs (10,730 SNPs). The total autosomal genome length, measured as the sum of the longest syntenic pairs of SNPs by chromosome, was 2,541.6 Mb (Mega base pairs). The average distances of all adjacent pairs by each BTA ranged from 0.55 to 0.74 cM. Decay of LD showed an exponential trend with physical distance. The means of LD ($r^2$) among syntenic SNP pairs were 0.136 at a range of 0-0.1 Mb in physical distance and 0.06 at a range of 0.1-0.2 Mb. When these results were used for Luo's formula, about 2,000 phenotypic records were found to be required to achieve power > 0.9 to detect 5% QTL in the population of Hanwoo. As a result of estimating effective population size by generation in Hanwoo, the estimated effective population size for the current status was 84 heads and the estimate of effective population size for 50 generations of ancestors was 1,150 heads. The average decreasing rates of effective population size by generation were 9.0% at about five generations and 17.3% at the current generation. The main cause of the rapid decrease in effective population size was considered to be the intensive use of a few prominent sires since the application of artificial insemination technology in Korea. To increase and/or sustain the effective population size, the selection of various proven bulls and mating systems that consider genetic diversity are needed.

• Journal of Life Science
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• v.23 no.11
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• pp.1397-1403
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• 2013

Fructus Sophorae, the dried ripe fruit of Styphnolobium japonicum (L.), is an herbal ingredient used in traditional Oriental medicine. This study was carried out to investigate the effects of Fructus Sophorae extracts (FSE) on immune modulation in a murine RAW 264.7 macrophage model. As immune response parameters, the production of prostaglandin $E_2$ ($PGE_2$) and tumor necrotic $factor-{\alpha}$ ($TNF-{\alpha}$) were evaluated. Our data revealed that FSE increased the macrophage activation and the production of $PGE_2$ and $TNF-{\alpha}$, which was consistently correlated with upregulation of cyclooxygenase-2 (COX-2) and $TNF-{\alpha}$ expression at both transcriptional and translational levels. On comparative cytokine protein array, FSE significantly increased several cytokines, which was associated with phosphorylation of mitogen- activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK), and Akt in RAW 264.7 cells. However, each inhibitor of these molecules attenuated the FSE-induced $PGE_2$ production. These results indicate that FSE activated macrophages through the activation of MAPKs and phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways in RAW 264.7 macrophages. These findings suggest that FSE may provide a promising source of an immunoenhancing agent.

• Neonatal Medicine
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• v.15 no.1
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• pp.67-74
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• 2008

Purpose : The purpose of this study was to assess the natural history and perinatal outcomes of twin gestations according to chorionicity. Methods : We retrospectively reviewed the medical records of 99 monochorionic (MC) and 206 dichorionic (DC) twin gestations delivered at Il Sin Christian Hospital in Busan between January 2002 and December 2007. The incidences of twin-to-twin transfusion syndrome (TTS) and selective intrauterine growth restriction (sIUGR), as well as perinatal morbidity and mortality, were evaluated. Results : MC twins had a lower gestational age (35.7 vs. 36.6 weeks, P=0.03) at birth and a higher incidence of intrauterine fetal loss (10% vs. 1.5%, P<0.001) than DC twins. The incidence of intrauterine fetal loss was higher in MC sIUGR than in DC sIUGR (19% vs. 2.5%, P=0.025) twins. The number of admissions to the neonatal intensive care unit (NICU; 31% vs. 16%, P=0.042), and the incidence of periventricular leukomalacia (7% vs. 0%, P=0.031), and respiratory distress syndrome with surfactant treatment (27% vs. 11%, P=0.049) were higher in MC than DC twins. The incidences of sIUGR and TTS were 21 and 9% among the MC twins. The incidences of intrauterine fetal loss were higher in MC twins with TTS [6 of 9 (67%)] or sIUGR [4 of 21 (19%)] than uncomplicated MC twins (P<0.001). The frequency of admission to the NICU (P=0.001), the length of hospital stay (P=0.033), the prevalence of periventricular leukomalacia (P=0.011), and intraventricular hemorrhage (P=0.007) were also higher in MC with TTS or sIUGR than in uncomplicated MC twins. Conclusion : The incidence of neonatal complications was higher in MC twins, especially those gestations complicated by TTS or sIUGR.

• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.333-343
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• 2002

Purpose: A new linker, hydrazino nicotinamide (HYNIC), was recently introduced for labelling of liposome with $^{99m}Tc$. In this study we synthesized HYNIC derivatized PEG (polyethylene glycol)-liposomes radiolabeled with $^{99m}Tc$. Materials and Methods: In order to synthesize HYNIC-DSPE (distearoyl phosphatidyl ethanolamine) which is a crucial component for $^{99m}Tc$ chelation, first of all succinimidyl 6-BOC-hydrazinopyridine-3-carboxylic acid was synthesized from 6-chloronicotinic acid by three sequential reactions. A DSPE derivative of succinimidyl 6-BOC-hydrazinopyridine-3-carboxylic acid was transformed into HYNIC-DSPE by HCI/dioxane. HYNIC-PEG-liposomes were prepared by hydration of the dried lipid mixture of EPC (egg phosphatidyl choline): PEG-DSPE : HYNIC-DSPE:cholesterol (1.85:0.15:0.07:1, molar ratio). The HYNIC-PEG-liposomes were labeled with $^{99m}Tc$ in the presence of $SnCl_2{\cdot}2H_2O$ (a reducing agent) and tricine (a coligand). To investigate the level of in vivo transchelation of $^{99m}Tc$ in the liposomes, the $^{99m}Tc$-HYNiC-PES-liposomes were incubated with a molar excess of DTPA, cysteine or glutathione solutions at $37^{\circ}C$ for 1 hour. The radiolabeled liposomes were also incubated in the presence of human serum at $37^{\circ}C$ for 24 hours. Results: 6-BOC-hydrazinopyridine-3-carboxylic acid was synthesized with 77.3% overall yield. The HYNIC concentration in the PEG-coated liposome dispersion was 1.08 mM. In condition of considering the measured liposomal size of 106 nm, the phospholipid concentration of $77.5\;{\mu}mol/m{\ell}$ and the liposomal particle number of $5.2{\times}10^{14}$ liposomes/ml, it is corresponded to approximate 1,250 nicotinyl hydrazine group per liposome in HYNIC-PEG-liposome. The removal of free $^{99m}Tc$ was not necessary because the labeling efficiency were above 99%. The radiolabeled liposomes maintained 98%, 96% and 99%, respectively, of radioactivity after incubation with transchelators. The radiolabeled liposomes possessed above 90% of the radioactivity in serum. Conclusion: These results suggest that the HYNIC can be synthesized easily and applied in labelling of PEG-liposomes with $^{99m}Tc$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.272-286
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• 2014

This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Cheonsu Bay, West Coast of Korea. Total species number was 224 and mean density was $1,940ind./m^2$, both of which were dominated by polychaete worms (111 species and $1,213ind./m^2$). In terms of density, the major dominant species were the bivalve Theora fragilis ($280{\pm}213ind./m^2$), the polychaetes Heteromastus filiformis ($254{\pm}218ind./m^2$), Lumbrineris longifolia ($216{\pm}41ind./m^2$), Mediomastus californiensis ($158{\pm}97ind./m^2$) and the amphipod Eriopisella sechellensis ($167{\pm}100ind./m^2$). As a result of community statistics (cluster analysis and nMDS ordination), the macrobenthic community structure was classified two major groups (inner and mouth of bay) and two stations (station 2 near Ganwol dyke in spring and summer). The Benthic Pollution Index (BPI) and AZTI's Marine Biotic Index (AMBI) were applied to assess the benthic ecological status. During the sampling periods, the BPI Index values varied between 11 (bad status) and 92 (high status). On the other hand, the AMBI Index values was ranged between 1.34 (good status) and 4.39 (poor status). In conclusion, in terms of the mean BPI and AMBI Index values, the ecological status of Cheonsu Bay were moderate status (ecotone stage) and good status, respectively.