• Journal of Gastric Cancer
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• v.2 no.2
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• pp.73-80
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• 2002

In spite the fact that H. pylori infection might be the causative organisms of acute and chronic gastritis, peptic ulcer diseases and the definition as the class I carcinogen by WHO IARC, still debates exist about the relationship between H. pylori and gastric carcinogenesis. Epidemiological and animal studies demonstrated a link between gastric cancer and chronic infection with H, pylori, but the exact mechanism responsible for the development of gastric cancer in H. pylori-infected patients still remain obscure. In order to declare the clear association, definate evidences like that decrement in the incidence of gastric cancer after the eradication of H. pylori in designated area compared to noneradicated region or the blockade of specific mechanism acting on the carcinogenesis by H. pylori infection. The other way is to identify the upregulating oncogenes or downregulating tumor suppressor genes specifically invovled in H. pylori-associated carcinogenesis. For that, we established the animal models using C57BL/6 mice strain. Already gastric carcinogenesis was developed in Mongolian gerbils infected with H. pylori, but there has been no development of gastric cancer in mice model infected with H. pylori after long-term evaluation. Significant changes such as atrophic gastritis were observed in mice model. However, we could observe the development of mucosal carcinoma in the stomach of transgenic mice featuring the loss of TGF-beta sig naling by the expressions of dominant negative forms of type II receptor specifically in the stomach. Moreover, the incidence of gastric adenocarcinoma was significantly increased in group administered with both MNU and H. pylori infection than MNU alone, signifying that H. pylori promoted the gastric carcinogenesis and there might be host susceptibility genes in H. pylori-associated gastric carcinogenesis. Based on the assumption that chronic, uncontrolled inflammation might predispose to carcinogenesis, there have been several evidences showing chronic atrophic gastritis predisposed to gastric carcinogenesis in H. pylori infection. Although definite outcome of chemoprevention was not drawn after the longterm administration of anti-inflammatory drug in H. pylori infection, the actual incidence of atrophic gastritis and molecular evidence of chemoprevention could be obtained. Selective COX-2 inhibitor was effective in decreasing the development of gastric carcinogenesis provoked by H. pylori infection and carcinogen like in chemoprevention of colon carcinogenesis.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.367-375
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• 2002

Background : Murine typhus is a flea-borne, worldwide Rickettsial disease caused by Rickettsia typhi. Its symptoms are typically mild but sometimes can be fatal. The major clinical features include fever, rash, and headache. Recently, we experienced 6 cases of ARDS associated with a Rickettsia typhi infection. This study was aimed to analyze the attributing factors for fatal murine typhus and to review the characteristics of the patients who showed acute respiratory distress syndrome as the initial presentation. Methods : The medical records of 15 patients diagnosed as murine typhus were reviewed. The diagnosis was made by single titers of 1:512 or higher, or a 4-fold rise with compatible clinical features. Acute Respiratory Distress Syndrome (ARDS) was defined according to the American-European Consensus Conference. The Characteristics between the ARDS group and the non-ARDS group of murine typhus were compared. Results : Six patients developed ARDS as their initial presentation. Two of them were women and three of them had lived urban area. None of Them a showed skin rash. One of them expired during treatment. The time lapse until the commencement of the specific treatment, the lower serum albumin level, the higher serum total bilirubin level, the higher APACHE III score and the higher MOD score were significantly associated with the ARDS group compared to the non-ARDS group. Conclusion : Murine typhus should be considered as one of the etiologies for the ARDS of unknown cause, particularly in an endemic regions. ARDS caused by Murine typhus generally has a good prognosis.

• Tuberculosis and Respiratory Diseases
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• v.60 no.3
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• pp.304-313
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• 2006

Background : Heme oxygenase-1 (HO-1) is an inducible enzyme that catalyzes the oxidative degradation of heme to form biliverdin, carbon monoxide (CO), and free iron. The current evidence has indicated a critical role of HO-1 in cytoprotection and also in other, more diverse biological functions. It is known that the high expression of HO-1 occurs in various tumors, and that HO-1 has an important role in rapid tumor growth because of its antioxidative and antiapoptotic effects. Therefore, the role of HO-1 was analyzed in human lung cancer cell lines, and especially in the A549 cell line. Material and Methods : Human lung cancer cell lines, i.e., A549, NCI-H23, NCI-H157 and NCI-H460, were used for this study. The expression of HO-1 in the untreated state was defined by Western blotting. ZnPP, which is the specific HO inhibitor we used, and the viability of cells were tested for by conducting MTT assaysy. The HO enzymatic activity, as determined via the bilirubin level, was also indirectly measured. Moreover, the generation of intracellular hydrogen peroxide (H2O2) was monitored fluorimetrically with using a scopoletin-horse radish peroxidase (HRP) assay and 2',7'-dichlorofluorescein diacetate (DCFH-DA). We have also transfected small HO-1 interfering RNA (siRNA) into A549 cells, and the apoptotic effects were evaluated by flow cytometric analysis and Western blotting. Results : The A549 cells had a greater expression of HO-1 than the other cell lines, whereas ZnPP significantly decreased the viability of the A549 cells more than the viability of the other lung cancer cells in a dose-dependant fashion. Consistent with the viability, the HO enzymatic activity also was decreased. Moreover, intracellular H2O2 generation via ZnPP was induced in a dose-dependent manner. Apoptotic events were, then induced in the HO-1 siRNA transfected A549 cells. Conclusion : HO-1 provides new important insights into the possible molecular mechanism of the antitumor therapy in lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.59 no.3
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• pp.298-305
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• 2005

Background : Obstructive sleep apnea syndrome (OSAS) is believed to have multifactorial causes. The major risk factors for OSAS are obesity, narrowed upper airways, and abnormal cranial-facial structures. A genetic basis for OSAS has been also suggested by reports of families with many members affected. This study analyzed the HLA typing in patients with OSAS to determine the possible role of genetics in OSAS. Methods : Twenty-five Korean patients with OSAS (1 woman and 24 men; age range 30-66 years) were enrolled in this study. A diagnosis of OSAS was made using full-night polysomnography. The control group consisted of 200 healthy Korean people. Serologic typing of the HLA-A and B alleles was performed in all patients using a standard lymphocyte microcytotoxicity test. Analysis of the polymorphic second exons of the HLA-DRB1 gene was performed using a polymerase chain reaction-sequence specific oligonucleotide probe. Results : The allele frequency of HLA-A11 was significantly lower in patients with OSAS compared with the controls (p<0.05). The HLA-B allele frequencies in the patients and controls had a similar distribution. Analysis of the HLADRB1 gene polymorphisms showed an increased frequency of DRB1*09 in the OSA patients compared with the controls (p<0.05). When the analysis was performed after dividing the OSAS patients according to the severity of apnea, the allele frequency of HLA-DRB1*08 was significantly higher in the severe OSA patients (apnea index >45) than in the controls (p<0.05). Conclusion : This study revealed an association between OSAS and the HLA-A11 and DRB1*09 alleles as well as association between the disease severity and the HLA-DRB1*08 allele in Korean patients. These results suggest that genetics plays an important role in both the development and the disease severity of OSAS.

• The Journal of the Korean bone and joint tumor society
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• v.13 no.1
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• pp.22-30
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• 2007

Purpose: We describe clinical, radiographic, MRI and pathologic findings as well as final outcome after simple curettage and bone graft of cystic fibrous dysplasia (FD) in the long bone, which has been rarely documented in the literature. Materials and Methods: Clinical records, radiographs, MRI and histologic slides of 11 patients with cystic FD in the long bone were retrospectively analyzed. Results: Six patients complained pain for several months, 4 patients presented pain after trivial injury event, and 1 patient suffered pathologic fracture. The mode of involvement was monostotic in 10 patients and polyostotic in l patient. The femur was affected in 7 patients, the humerus in 3, and the radius in 1. Radiography showed prominent, expansive lysis associated with ground-glass density of FD. MRI revealed 2 different signals of FD and cyst. Microscopic examination revealed classic findings of FD and non-specific cystic degeneration. The final outcome was satisfactory in every patient. Local recurrence was not observed. Conclusion: Cystic FD in the long bone seems not as rare as the scarcity of reported cases would indicate. MRI features provide a basis for differential diagnosis between benign cystic change and malignant transformation. Cystic FD would be an indication for surgery and simple curettage with allo-chip-bone graft is effective.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.278-286
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• 2006

Purpose : Although suprapubic bladder aspiration(SBA) is the most reliable technique for identifying bacteriuria in young infant, no report has been published about the clinical manifestations of urinary tract infection(UTI) diagnosed by aspirated urine in Korea. This study was performed to examine clinical manifestations and related factors of UTI confirmed by a positive urine culture obtained by SBA in young infants. Methods : We reviewed medical records of 159 infants younger than six months of age, who had been admitted for UTI to Korea University Ansan Hospital from January 2002 to June 2005. Results : The male:female ratio was 5.1 : 1. The most common pathogen in urine culture was Escherichia coli(92.5 percent). Most of the gram-negative pathogens had high sensitivity to amikacin, or third generation cephalosporins and had low sensitivity to ampicillin, trimethoprim-sulfamethoxazole, or gentamicin. Hydronephrosis and vesicoureteral reflux(VUR) were present in 32.7 percent and 27.7 percent respectively. Renal cortical defects observed on DMSA scans were detected in 37.1 percent. Prolonged fever duration and hospital day, high erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) levels, hydronephrosis and VUR were related to the renal cortical defects(P<0.05). Rates of UTI-associated bacteremia and aseptic meningitis were 8.3 percent and 6.6 percent. Conclusion : Early differential diagnosis is very important in infants younger than 6 months of age with UTI because the clinical findings are non-specific and UTI-associated bacteremia and aseptic meningitis are concomitantly found. Because prolonged fever and higher ESR and CRP levels are risk factors of the renal cortical defects, radiologic evaluations and nephrologic follow-up were needed in identifying the predisposing congenital abnormalities and chronic renal scarring.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.980-986
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• 2002

Purpose : Although the number of patients with measles have dramatically decreased since the introduction of measles vaccines in 1965, measles outbreaks have occurred periodically every 4-6 years during the 1990s(1989-1990 and 1993-1994). During 2000-2001, measles prevailed all over the country again. A characteristic of current epidemics is that the majority of affected population was infants and school-aged children. This study was designed to analyze the epidemic and clinical features of measles prevalence during 2000-2001 and to find ways to overcome vaccination failure. Methods : We reviewed the records of 59 patients with mealses admitted in the Pediatric Department of Pusan National University Hospital from January 2000 to October 2001 for patient's age, month of admission, history of vaccination, clinical features and complications. Antibody titers of measles-specific IgM and IgG were measured by enzyme immunoassay. Results : The epidemic show two peaks in the age distribution. Forty three patients(72.9%) were under 2-years of age and 14 patients(23.7%) were over 5-years of age. Outbreaks had high incidence in July to August, 2000 and March to April, 2001, then faded away after July, 2001. Vaccinated group comprised 30.5% and unvaccinated group comprised 69.5% and their mean age was $9.25{\pm}4.27$ years old and $0.95{\pm}0.30$ years old respectively. Positive rate of IgM was 86.7% in vaccinated group and 90.3% in unvaccinated group. This means there was primary vaccine failure; 13 cases of 15 vaccinated patients were positive in IgM antibody. During the prevalence, two patients died with mealses complication. One of them was immunocompromised. Conclusion : To prevent another prevalence of measles in the future, we must enhance revaccination at ages 4-6 and check vaccination status when children enter elementary school. These will produce over 95% of herd immunity, with catch-up MMR vaccination which has been completed already.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.253-258
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• 2004

Purpose: Chitosan has been studied as a non-viral gene delivery vector, drug delivery carrier, metal chelator, food additive, and radiopharmaceutical, among other things. Recently, galactose-graft chitosan was studied as a non-viral gene and drug delivery vector to target hepatocytes. The aim of this study was to investigate the usefulness of nuclear imaging for in vivo evaluation of targeting the hepatocyte by galactose grafting. Methods and Materials: Galactosyl methylated chitosan (GMC) was produced by methylation to lactobionic acid coupled chitosan. Cytotoxicity of $^{99m}Tc$-GMC was determined by MTT assay. Rabbits were injected via their auricular vein with $^{99m}Tc$-GMC and $^{99m}Tc$-methylated chitosan (MC), the latter of which does not contain a galactose group, and images were acquired with a gamma camera equipped with a parallel hole collimator. The composition of the galactose group in galactosylated chitosan (GC), as well as the tri-, di-, or mono-methylation of GMC, was confirmed by NMR spectroscopy. Results: The results of MTT assay indicated that $^{99m}Tc$-GMC was non-toxic. $^{99m}Tc$-GMC specifically accumulated in the liver within 10 minutes of injection and maintained high hepatic uptake. In contrast, $^{99m}Tc$-MC showed faint liver uptake. $^{99m}Tc$-GMC scintigraphy of rabbits showed that the galactose ligand principally targeted the liver while the chitosan functionalities led to excretion through the urinary system. Conclusion: Bioconjugation with a specific ligand endows some degree of targetability to an administered molecule or drug, as in the case of galactose for hepatocyte in vivo, and evaluating said targetabililty is a clear example of the great benefit proffered by nuclear imaging.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.3
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• pp.131-140
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• 2015

To set up unicellular cyanobacterial strains with photo-biological $H_2$ production potential, live samples were repeatedly collected from 68 stations in the coastal zone of Korea for the four years since 2005. Among 77 cyanobacterial strains established six (KNU strains, CB-MAL002, 026, 031, 054, 055 and 058) were finally chosen as the excellent strains for $H_2$ production with $H_2$ accumulation over 0.15 mL $H_2\;mL^{-1}$ under general basic $H_2$ production conditions as well as positive $H_2$ production for more than 60 hr. To explore optimum procedures for higher $H_2$ production efficiency of the six cyanobacterial strains, the inter-strain differences in the growth rate under the gradients of water temperature and salinity were investigated. The maximum daily growth rates of the six strains ranged from 1.78 to 2.08, and all of them exhibited $N_2-fixation$ ability. Based on the similarity of the 16S rRNA sequences, all the test strains were quite close to Cyanothece sp. ATCC51142 (99%). The six strains, however, were grouped into separate clades from strain ATCC51142 in the molecular phylogeny diagram. Chlorophyll- a content was 3.4~7.8% of the total dried weight, and the phycoerythrin and phycocyanin contents were half of those in the Atlantic strain, Synechococcus sp. Miami BG03511. The growth of the six strains was significantly suppressed at temperatures above the optimal range, $30{\sim}35^{\circ}C$, to be nearly stopped at $40^{\circ}C$. The growth was not inhibited by high salinities of 30 psu salinity in all the strains while strain CB055 maintained its high growth rate at low salinities down to 15 psu. The euryhaline strains like CB055 might support massive biotechnological cultivation systems using natural basal seawater in temperate latitudes. base seawater. The biological and ecophysiological characteristics of the test strains may contribute to designing the optimal procedures for photo-biological $H_2$ production by unicellular cyanobacteria.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.400-407
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• 2006

Twenty six strains of lactic acid bacteria were isolated from Jeung-pyun batter, among which Tetragenococcus halophilus 1-12 showed highest dextransucrase activity at 36.95 DSU/mg, followed by T. halophilus 5-8 (36.87 DSU/mg protein), T. halophilus 2-12 (32.66 DSU/mg protein), T. halophilus 3-3 (31.43 DSU/mg protein), T. halophilus 3-1 (30.73 DSU/mg protein), T. halophilus 5-12 (29.43 DSU/mg protein), and Leuconostoc mesenteroides subsp mesenteroides 2-9 (28.5 DSU/mg protein). L. mesenteroides subsp mesenteroides 2-9, T. halophilus 1-12, and L. mesenteroides subsp dextranicum 5-13, were selected as starters (0.1, 0.5, and 1.0%) for Jeung-pyun manufacturing. Specific volume of Jeung-pyun added with 1.0% L. mesenteroides subsp dextranicum 5-13 was highest at 2.00, and 1.0% T. halophilus 1-12-added Jeung-pyun was lowest at 033. Cross-sectional observation of Jeung-pyun showed Jeung-pyun added with 0.5% L. mesenteroides subsp mesenteroides 2-9 was uniformly formed. Number of air holes of Jeung-pyun increased with increasing amount of added T. halophilus 1-12. Increasing addition of L. mesenteroides subsp dextranicum 5-13 resulted in more uniform air holes and volumes. Hardness, gumminess, and chewiness of Jeung-pyun added with 0.5 and 2.0% L. mesenteroides subsp dextranicum 5-13 decreased significantly in compasion to control groups. Jeung-pyun added with 0.5% L. mesenteroides subsp dextranicum 5-13 showed excelIent overall sensory desirability ranking of 8.500.