• Korean Journal of Ecology and Environment
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• v.55 no.1
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• pp.84-98
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• 2022

Estuary is important in terms of biodiversity because it has the characteristics of transition waters, created by the mixing of fresh- and seawater. The estuarine water circulation provides a variety of habitats with different environments by inducing gradients in the chemical and physical environment, such as water quality and river bed structure, which are ultimately the main factors influencing biological community composition. If the water circulation is interrupted, the loss of brackish areas and the interception of migration of biological communities will lead to changes in the spatial distribution of biodiversity. In this study, among the sites covered by the Estuary Aquatic Ecosystem Health Assessment, we selected study sites where changes in biodiversity can be assessed by spatial gradient from the upper reaches of the river to the lower estuarine area. The α-, γ- and β-diversity of diatom, benthic macroinvertebrates, and fish communities were calculated, and they were divided into open and closed estuary data and compared to determine the trends in biodiversity variation due to estuarine circulation. As results, all communities showed higher γ-diversity at open estuary sites. The benthic macroinvertebrate community showed a clear difference between open and closed estuaries in β-diversity, consequently the estuarine transects were considered as a factor that decreases spatial heterogeneity of their diversity among sites. The biodiversity trends analyzed in this study will be used to identify estuaries with low γ- and β-diversity by community, providing a useful resource for further mornitoring and management to maintain estuarine health.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.2
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• pp.123-131
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• 1986

This study was conducted to evaluate the effect of annual application of silicate fertilizer on rice yield and soil physico-chemical properties. Field experiment was done on the condition of fertilization of silicate fert. 150 and 250kg/10a to the clay loam paddy field for ten years from 1975 to 1984. Data for rice growth and nutrient uptake was analyzed for ten years base. The results obtained are as follows. 1. Average unhulled rice yield for 10 years increased at 16% in the treat of silicate fert. 150kg/10a annually applied in comparison with the N.P.K treated plot, but silicate fert. 250kg/10a treated plot was decreasing tendency somewhat in yield. 2. Amount of potassium uptake of rice straw at the harvesting stage was positively significant recognized with unhulled rice yield and straw yield of rice plant. 3. The amounts of N, $P_2O_5$ and $K_2O$ uptake in the treat of silicate fert. 150kg/10a were much more than those of silicate fert. 250kg/10a treated plot. However the treat of silicate fert. 250kg/10a increased the amounts of CaO, MgO and Silica uptake than other treats markedly. Especially the treat of silicate fert. 150kg/10a was higher in nitrogen recovery rate than other nutrients recovery rate, but the recovery of silica was low. 4. The treat of silicate fert. 250kg/10a annually applied markedly decreased the translocation rate of nitrogen, potassium and silica from straw to the unhulled rice grain. 5. Ten years' average value of soil O.M. content was much more in the treat of silicate fert. 150kg/10a which show higher yield increase than other treats, but in the treat of silicate fert. 250kg/10a, soil O.M. content was lower, however silicate content in soil was the most among other treats.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.2
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• pp.207-212
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• 2001

Purpose: Mycoplasma pneumoniae infection is relatively common in childhood. Its extrapulmonary manifestations have been reported so much, but hepatitis associated with it has not been studied yet until now in Korea. Methods: We performed the prospective study of 19 cases that had AST and ALT>50 IU/L respectively without evidence of hepatitis A, B, C, cytomegalovirus, and Ebstein-Barr virus infections amongst 143 patients with M. pneumoniae pneumonia who were admitted to the Department of Pediatrics, Seoul Red Cross Hospital from Jan. 1999 to Dec. 2000. Results: 1) Hepatitis occurred in 13.3% of Mycoplasma pneumoniae infection, especially in fall and winter times. The average age was 4.86 years and male to female ratio was 2.2:1. 2) Vomiting was developed in 21.1%, diarrhea in 36.8%, and hepatomegaly in 21.1%, respectively. And leukocytosis was noted in 21.1%, eosinophilia in 15.4%, anemia in 10.5%, and thrombocytosis in 5.3%, respectively. The average level of C-reactive protein was $6.34{\pm}4.82$ mg/dl. 3) There was no hyperbilirubinemia, but hypoalbuminemia was detected in 42.1%. The average serum levels of AST and ALT were $214.05{\pm}183.22$ IU/L and $284.16{\pm}286.84$ IU/L, respectively. 4) Chest radiology showed lobar or lobular consolidation in 73.7%, bronchial infiltration in 26.3%, and pleural effusion in 31.6%. 5) The average length of hospitalization was 7.9 days, and the average length of normalization of serum transaminases was 8.8 days. All patients recovered within 2 weeks completely. Conclusion: The prognosis of M. pneumoniae hepatitis is good. However, its incidence is not so low that liver function should be considerately checked in case of M. pneumoniae infection.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.170-178
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• 2004

Purpose: Helicobacter pylori (H. pylori) infection has been known to be vital in the pathogenesis of duodenal ulcer disease in children as well as in adults. But the relationship between H. pylori infection and the histopathologic findings of the duodenum has not been explained obviously in children yet. So the aim of this study is to determine whether duodenitis and/or gastric metaplasia in the duodenum increases the risk of duodenal ulcer disease in children infected by H. pylori. Methods: From October 2001 to April 2004 gastric and duodenal biopsies were performed in 177 children who visited Department of Pediatrics, Gil Hospital, Gachon Medical School. Biopsy sections were stained with hematoxylin and eosin and also with Giemsa for identification of H. pylori. The grades of duodenitis and gastric metaplasia were classified from 0 to 3 and from 0 to 4, respectively. Results: The incidence of H. pylori infection was 54% in total patients. Amongst 163 children with duodenitis there was a lack of correlation between H. pylori infection and the grade of duodenitis. Amongst 11 patients with duodenal ucler, only 4 children were infected by H. pylori. And amongst 5 patients with gastric metaplasia, H. pylori and duodenal ulcer were detected in 2 and 3 children, respectively. The occurrence of duodenal ulcer and gastric metaplasia were increased significantly in proportion to the grade of duodenitis (p<0.0001 and p=0.0365, respectively). Conclusion: As opposed to the results of previously reported articles, there were lacks of correlation between H. pylori infection and duodenitis, duodenal ulcer, and gastric metaplasia. So further study hould be done to clarify the effect of H. pylori on the duodenal histopathology in children infected by H. pylori.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.6 no.1
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• pp.1-9
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• 2003

Purpose: To investigate the relation of the gastric epithelial cell proliferation, apoptosis and genotypes of H. pylori in children. Methods: Histologic grading by updated Sydney system, PCNA immunostaining, TUNEL method and the genotypes (cagA, picB and iceA) by PCR were performed in H. pylori positive (N=20) and negative (N=20) gastric biopsy specimens. Results: PCNA index was significantly different between H. pylori positive children ($77.4{\pm}13.12$) and H. pylori negative children ($52.3{\pm}12.20$) (p=0.000). There were positive correlations between PCNA index and H. pylori density (r=0.624, p=0.000), polymorphonuclear neutrophil activity (r=0.460, p=0.005) and chronic inflammation (r=0.433, p=0.009). Apoptosis index of H. pylori positive children ($0.70{\pm}0.411$) was significantly higher than of H. pylori negative children ($0.14{\pm}0.201$) (p=0.000). Positive correlations between apoptosis index and H. pylori density (r=0.691, p=0.000), polymorphonuclear neutrophil activity (r=0.585, p=0.000) and chronic inflammation (r=0.535, p=0.001) were noted. As PCNA index increased, apoptosis index significantly increased (r=0.527, p=0.001). The positive rates of genotypes were cagA 90%, picB 75%, iceA1 60% and iceA2 15%, respectively. There were no significant correlations between the status of the genotypes and PCNA index, apoptosis index, the endoscopic findings and the histologic findings. Conclusion: PCNA index and apoptosis index in H. pylori positive children were higher than in H. pylori negative children but were not related to H. pylori genotypes. This study suggested that correlatively increased gastric epithelial cell proliferation and apoptosis are important to pathogenesis of H. pylori infection in children.

• Neonatal Medicine
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• v.18 no.2
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• pp.204-210
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• 2011

Purpose: Feeding intolerance is common in very low birth weight infants(VLBWI); however, research on the etiology is limited. We investigated the incidence of allergic enterocolitis (AEC) as a cause of feeding intolerance and present the clinical characteristics of VLBWIs. Methods: The medical records of VLBWIs admitted to the neonatal intensive care unit of Samsung Medical Center between January 2009 and July 2010 were retrospectively analyzed. AEC was defined as patients who had feeding intolerance with eosinophila and who responded to hypoallergenic feeding intervention. Feeding intolerance symptoms included blood tinged stools, abdominal distension, residual feeding and regurgitation. Eosinophilia was defined as an eosinophil count ${\geq}$700 cells/$mm^3$. Patients with feeding intolerance were divided into the AEC or non-AEC group. Results: Of the 181 patients, 161 (88.9%) had a feeding intolerance, and 119 (65.7%) had eosinophilia. Seventeen infants were diagnosed with AEC. No difference in mean gestational age, birth weight, antibiotics duration, TPN duration, hospitalization, or symptom onset day was observed between patients with AEC and non-AEC patients. The percentage of eosinophilia was significantly higher in patients with AEC than in non-AEC patients. Two patients (12%) improved with restricted breast milk, 10 patients (59%) with extensively hydrolyzed formula and five patients (29%) with free amino acid-based formula. Conclusion: Our results suggest that AEC should be considered in VLBWIs who have clinical features of feeding intolerance and eosinophilia. An aggressive increase in feeding would be possible through feeding intervention in VLBWIs with feeding intolerance.

• Journal of Nutrition and Health
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• v.4 no.4
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• pp.39-46
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• 1971

Since ${\beta}-aminoethylphosphonic$ acid was discovered in the living organism, the biosynthesis and biological function of aminophosphonic acids have been extensively studied. The purpose of this project consists in the two parts: 1)the preparation of DL-1-amino-2-phenylethylphosphonic acid (Phenylalanine aminophosphonic acid) and DL-1-amino-3-methylbutyl-phosphonic acid (Isoleucine aminophosphonic acid) by the method of Chamber and Isbell. 2) the study of metabolism and biological functions of those synthetic materials by the animal experiment (white rats) The importance of this project proved to be the first experience fed by animals for the elucidation of biochemical and metabolic functions in the animal body. The following organic synthesis of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid are studied. 1)Synthesis of DL-1-amino-3-methylbutylphosphonic acid a) Synthesis of Iso-butylbromide b) Synthesis of Ethyl iso-butylmalonate c) Synthesis of Iso-caproic acid d) Synthesis of $Ethyl-{\alpha}-bromo$ iso-caproate e) Synthesis of $Triethyl-{\alpha}-phosphono$ iso-caproate f) Synthesis of DL-1-amino-3-methylbutylphosphonic acid 2)Synthesis of DL-1-amino-2-phenylethylphosphonic acid a) Synthesis of Diethyl phosphite b) Synthesis of Ethylchloro acetate c) Synthesis of Triethyl phospho acetate d) Synthesis of Triethyl benzyl phospho acetate e) Synthesis of DL-1-amino-2-phenylethylphosphonic acid The synthetic compounds; DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenyl ethylphosphonic acid which are essential amino acid (isoleucine, phenylalanine)analogue are supplemented to the animal diet at the level of 0.2% and 0.4% for isoleucine analogue and 0.35% and 0.7% for phenylalanine analogue. The plain isoleucine and phenylalanine at the same level in the diet are fercilitated as comparable groups in this study. Two sets of experience including 100 male rats were carried out for seven weeks each total 14 weeks. During this period, urine samples, and each big organs were collected for the analysis of total nitrogen, phosphorus, and glycogen contents in the individual samples by Micro Kjeldahl Fisk & Subbarow and Nelson Somogye, method. 1) The result of the project a) The yield of DL-1-amino-3-methylbutylphosphonic acid and DL-1-amino-2-phenylethylphosphonic acid showed low tendency at the level of 12.5% and 20% Melting point of those two compounds were very high and the ${\alpha}-amino$ group in the synthetic compounds showed positive reaction with ninhydrin in the violet color. b) Ail the experimental groups included in this study revealed statistically no significant difference in the organ weight, total body nitrogen retention and urinary phosphorus excretion This means isoleucine aminophosphonic acid and Phenylalanine aminophosphonic acid were utilized in the body as much as the plain amino acids, isoleucine and phenylalanine did. c) The glycogen contents in the liver of the phenylalaine aminophosphonic acid gruop showed higher statistically significant(p<0.05) in the comparision with the group of the Phenylalanine and the Standard-2. It was noteworthy that the higher glycogen content in the liver might indicate the significance in the incorporation of phenylalanine aminophosphonic acid into the intermediate of tricarboxylic acid cycle as activated state.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.689-695
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• 2009

Purpose : To examine the effect of bosentan, a dual endothelin receptor (ER) antagonist, on the development of monocrotaline (MCT)-induced pulmonary hypertension in rats by especially focusing on the pulmonary vascular morphology changes. Methods : Sprague-Dawley rats were treated as follows: controls received a subcutaneous saline injection, MCT-treated rats received a subcutaneous MCT injection, and bosentan-treated rats received a MCT injection followed by treatment with bosentan (20 mg/kg/day). To assess the effects of ER blockade on the time course, the animals were exsanguinated, and their hearts and lungs were dissected after 7, 14, or 28 days. Results : The mean body weights of the MCT- and bosentan-treated rats were significantly lower than that of the control rats on days 7, 14, and 28. Bosentan administration significantly inhibited the progression of right ventricular hypertrophy on day 28 (right ventricle/[left ventricle＋septum]: $0.71{\pm}0.10$ in MCT-treated rats vs. $0.49{\pm}0.09$ in bosentan-treated rats; P<0.05). Quantitative analysis of peripheral pulmonary arteries revealed that the increase in medial wall thickness after MCT injection was significantly attenuated in the bosentan-treated rats on day 28 ($49.96{\pm}10.06%$ in MCT-treated rats vs. $47.09{\pm}10.48%$ in bosentan-treated rats; P<0.05). In addition, the increase in the number of intra-acinar muscular arteries after MCT injection was reduced by bosentan on days 14 and 28. Conclusion : Bosentan administration in intermediate doses exerts inhibitory effects on lung vascular hypertrophy and right ventricular hypertrophy during the development of MCT-induced pulmonary hypertension in rats.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.47-53
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• 2001

Purpose: Following up the cases of cow's milk-sensitive enteropathy (CMSE), We observed the development of clinical tolerance with cow's milk and other foods. We investigated the clinical outcome of CMSE. Methods: We reviewed the clinical records of patients who had been admitted and diagnosed as CMSE by responses to cow's milk challenge and elimination test and the findings of small intestinal biopsy at Department of Pediatrics, Taegu Catholic University Hospital from March 1992 to March 1997. All of them were being fed with protein hydrolysate before 6 months old, and tried cow's milk and other foods challenge test at following each two month. Twenty-one cases of them returned to be followed. The age at admission was $30.7{\pm}8.8$ (18~47) days old and at survey was $43.4{\pm}23.7$ (16~84) months old. Results: 1) Although the body weight at birth of the patients was 25~75 percentile, all on admission was below 3 percentile. The body weight on interview was 25~75 percentile. 2) The development of clinical tolerance in cow's milk was observed at 16~24 months of age and the tolerance rate was 61% at 12 months of age, 90% at 16 months of age. The development of clinical tolerance in other foods was observed at 10~24 months of age and the tolerance rate was 33% at 12 months of age, 80% at 18 months of age. 3) Adverse reactions after challenge test with cow's milk were observed at 19 cases, manifestated as vomiting (31%), diarrhea (31%), irritability or lethargy (21%), skin rash (10%), and abdominal distention (5%). 4) Comparing serum IgE and milk RAST positive group on admission (5 cases) and negative group on admission (16 cases), there was no significant difference at the age of tolerance in cow's milk (p>0.05), the age of tolerance in other foods (p>0.05), allergy history in family, and the incidence of other allergic diseases. 5) The history of family allergy was observed in 3 cases (14%) in 21 patients and 3 cases (14%) showed rhinitis, urticaria or asthma through a follow-up interview. Conclusion: The development of clinical tolerance in cow's and other foods was sharply increased at 12 months of age and most of all tolerated within 24 months of age. CMSE is a temporary disorder of infancy.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.63-70
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• 2001

Purpose: The aim of this study is to evaluate the effective role of living-related liver transplantation (LRLT) on posttransplant linear growth in children. Methods: Thirty six children were enrolled who received LRLT at Asan Medical Center from December, 1994 to February, 1999 and showed more than one-year postoperative survival. Mean height standard deviation score (zH) was analyzed according to medical records including heights during pretransplant and posttransplant follow-up periods. Results: zH of total children showed significant linear growth after LRLT from -1.58 to 0.33 at 24 posttransplant month (p<0.05). zH in children under 6 years of age, to exclude the effect of adolescent linear growth spurt, showed increment in height (p<0.05). Linear growth of children with liver cirrhosis improved and that with fulminant hepatitis was matained same. While stunted children (mean zH=-2.30) achieved good catch-up growth after transplantation, children with normal growth remained same. Children with significant hepatic dysfunction after LRLT such as chronic rejection or posttransplant lymphoproliferative disorder showed retarded posttrasplant linear growth. There was no statistical difference according to the type of immunosuppressants. Conclusion: LRLT resulted in adequate or catch-up linear growth in children with acute, chronic and metabolic liver disease. Successful LRLT suggested to be a promising option not only in long term survival but also in normal linear growth.