• Journal of Aquaculture
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• v.21 no.4
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• pp.325-330
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• 2008

Two different Eelwardsiella tarda isolates, KFE and Edk-2, were obtained from Korea and Japan respectively. On the base of the previous results showing higher pathogenicity of E. tarda KFE compared to that of E. tarda Edk-2 isolate, we tried to determine the differences of antigenicities of these two isolates in loach which is one of the important species in freshwater aquaculture in Korea. Concentration of specific antibody in the serum appeared to be much higher in loach immunized with FKC of E. tarda Edk-2 than those found in loach immunized with FKC of E. tarda KFE. Cross-reaction analysis using agglutination test with normal and antigen-absorbed antisera implied the differences epitopes in the antigens of these E. tarda isolates. For the comparison of bactericidal activity of the produced antibody with different antigens, absorption analysis was performed and confirmed the presence of critical epitopes in the FKC of E. tarda KFE strain. The prophylactic agent, polysaccharide-bound protein (PS-K) injected 1 week before the artificial infection with E. tarda KFE isolates decreased the cumulative mortality in loach and would be on effective method to prevent the occurrence of bacterial infection including E. tarda.

• Pediatric Infection and Vaccine
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• v.6 no.2
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• pp.194-202
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• 1999

Background : Group B ${\beta}$-hemolytic Streptococcus(GBS) has been the major pathogen of neonatal sepsis in western country. In contrast, GBS has played little role in neonatal sepsis in Korea. But recently, neonatal GBS infections are encountered more frequently. It is important to characterize the clinical and epidemiological features of GBS infection in Korean children. Methods: We reviewed retrospectively the medical records of twenty-seven infants and children with GBS infection experienced at the Seoul National University Children's Hospital during 14 year-period from June, 1985 to June, 1999. Fourteen strains isolated from blood and cerebrospinal fluid were serotyped. Minimum inhibitory concentrations of 10 strains were determined by agar dilution method for penicillin, ampicillin, ampicillin with sulbactam, cefarolin, cefuroxime, and cefuiaxone. Results: The numbers of cases with GBS infection increased in 1990s. Among twenty seven cases, twenty-five cases were under three months of age and both of two cases with underlying disease occurred at three years of age. All neonatal infections were late-onset type and meningitis predominated. Serotypes were III(6 strain), Ib(4), Ia(l) and V(2). All of the strain were susceptible to all of the antibiotics tested. Conclusion: GBS infections in infants were increasingly recognized. GBS should be considered as an etiological agent of neonatal sepsis or meningitis in Korea. Maternal screening and prophylactic antibiotic therapy may be considered.

• Journal of fish pathology
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• v.20 no.3
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• pp.211-220
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• 2007

Red sea bream iridovirus disease (RSIVD) cause massive economic losses in marine aquaculture industry in Korea. The causative agent of this disease (RSIV) infects a wide range of fish species. The aims of this study were to monitor RSIV in wild marine fishes and to give critical information for controling the disease through prophylactic methods. Prevalence of the viral disease, geological distribution and reservoir of the virus were investigated using wild marine fishes captured in southern coast and east china sea for two years. (Polymerase Chain Reaction) PCR results showed that RSIV were detected in 39 (24.3%) out of 160 fish. MCP gene sequences of viral strains isolated in this study were closely related to that of a reference strain, red seabream-K, belonging to Megalocytivirus subgroup Ⅲ. The results suggest that some of wild marine fishes are RSIV carriers and may spread the pathogen directly to fish farmed in coastal area.

• The Journal of Internal Korean Medicine
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• v.31 no.2
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• pp.224-241
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• 2010

Objectives : The aim of the current study was to investigate the effects of Sargassum (Sargassum pallidum (TURN.) C. AG.; SP) on the experimental colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice. Methods : ICR mice were divided into 7 groups (NOR, CON, $SS50\times5$, $SP20\times3$, $SP50\times3$, $SP20\times5$, $SP50\times5$). TNBS processing was intrarectally applied to all experimental groups on the 3rd experiment day, except the normal group (NOR). For investigating the prophylactic effect, SP at doses of 20 mg/kg ($SP20\times5$) and 50 mg/kg ($SP50\times5$) were orally administered for 5 days. The SP at doses of 20 mg/kg ($SP20\times3$) and 50 mg/kg ($SP50\times3$) were orally administered for 3 days after the colitis induction in order to check the effect of treatment. As a positive control group, sulfasalazine 50 mg/kg ($SS50\times5$) was administrated. Macroscopic findings of epithelial tissue on mice were measured by colon length and macroscopic score. Histologic findings were also checked by crypt cell, epithelial cell, inflammatory cell and edema of submucosa. We measured the ability of SP to inhibit lipid peroxidation and myeloperoxidase activity. We also measured levels of the inflammatory markers, interleukin (IL)-$1\beta$ and cyclooxygenase-2 (COX-2), its transcription factor activation, phospho-NF-${\kappa}B$ (pp65), in the colon by enzyme-linked immunosorbent assay and immunoblot analysis. We measured activation of fecal bacterial enzyme, $\beta$-glucuronidase and degradation activation of fecal glycosaminoglycan (GAG), and hyaluronic acid. Results : Oral administration of SP on mice inhibited TNBS-induced colon shortening and myeloperoxidase activity in the colon of mice as well as IL-$1\beta$ and COX-2 expression. SP also inhibited TNBS-induced lipid peroxidation and pp65 activation in the colon of mice. SP inhibited $\beta$-glucuronidase activation and fecal hyaluronic acid degradation activation as well. Conclusions : SP could be a possible herbal candidate and preventive prebiotic agent for treating inflammatory bowel disease (IBD). Further experiments to differentiate effects of SP on IBD, such as other solutions and extracting times, might be promising.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.1
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• pp.18-23
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• 2000

The changes of the microorganism composition after therapeutic radiation for oral cancer patients are not well known and the long-term follow-up data are not reported. To obtain basic data for understanding of pathogenesis and prevention and treatment of dental caries and mucositis occuring after radiation therapy, 7 of the oral cancer patients presented at the Seoul National University Oral & Maxillofacial Department between 1997 and 1998 whose treatment plan included radiation therapy were recruited to investigate the changes in bacterial composition(total aerobic count, Candida, Staphylococci, Lactobacilli, S. mutans, and S. salivarius (mitis, sanguis)) of the saliva before, during, and after radiation therapy. The basic data obtained from this study on identification and composition change of the bacteria in saliva of patients treated with radiation therapy can be used (1) as a reference for deciding on the ideal anti-microbial spectrum of the oral rinsing agent to be used in patients treated with radiation therapy for malignant tumor of the head and neck region. (2) to enhance the understanding of increase of opportunistic infection after immunochemical changes of the saliva and its relation to specific bacterial infection. (3) as a reference in prescribing prophylactic antibiotics in immunodepressed patients after radiation therapy.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.52-60
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• 1993

Panax ginseng has been extensively used in the traditional oriental medicine as a restorative, tonic and Prophylactic agent. Recently, several reports regarding to anticancer effects of Panax ginseng has accumulated. These studies emphasized the fact that the anticancer activities might be due to a glycoside group called ginsenoside or pan.u saponin which has a water soluble characteristic. However, the authors and collaborates demonstrated that a highly lipid soluble component in extract of Panax ginseng roots contains a considerable cytotoxic activities against marine leukemic cells (L1210, P388) and human censer cells (HRT-18, HT-29, HCT48). This study was devised to observe the cytotoxic activities of Petroleum-ether extract of Panax giuseng roots (crude GBD and its Partially Purified fraction from silicic acid column chromatography (7 : 3 GX) against sarcoma-180 (5-180) and Walker carcinosar- coma 256 (Walker 256) in vivo, and murine leukemic Lymphocytes (L1210) and human rectal cancer cells (HRT-18) and human colon cancer cells (HT-29 and HCT48) in vitro. Each cell-line was cultured in medium containing serial concentration of the crude GX or 7 : 3 GX in vitro. A highly lipid soluble compound in the extract of Panax ginseng root was cytocidal to murine leukemic cells and human colon and rectal cancer cells in vitro. In the meantime, ginseng saponin derivatives did not have cytotoxic effects at its corresponding concentration. The growth rates of the cancer cells in medium containing ginseng extracts were inhibited gradually to a significant degree roughly in proportion to the increase of the extract concentration. The cytotoxic activity of 7 : 3 GX was about 3 times more potent than that of crude GX, one unit of cytotoxic activity against L1210 cells being equivalent to 2.54 Ug and 058 Ug for the crude GX and 7 : 3 GX, respectively. The Ri value of the active compound on silica- gel thin layer chromatography with petroleum-ether/ethyl ether/acetic acid mixture (90 : 10 : 1, v/v/v) as a developing so lvent was 053. While, the Panaxydol and Panaxynol as active compounds were purified from Petroleum-ether extract of Panax ginseng root by Drs. Ahn and Kim, and author found out that the one unit of cytotoxic activity of the Panaxydol and Panaxynol against L1210 cells being equivalent to 056 Ug and 0.3918 respectively. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times by the 7 : 3 GX treatment compared with their control group. The significantly decreased hemoglobin values of rats after inoculation with Walker 256 were recovered to normal range by oral administration of the crude Gt The synthetic levels of protein, DNA and RNA in human colon and rectal cancer cells were significantly diminished by treatment with the crude GX, which can explain a part of the origin of its anticancer activity.

• Journal of Microbiology and Biotechnology
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• v.29 no.4
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• pp.651-657
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• 2019

Although smallpox was eradicated in 1980, it is still considered a potential agent of biowarfare and bioterrorism. Smallpox has the potential for high mortality rates along with a major public health impact, eventually causing public panic and social disruption. Passive administration of neutralizing monoclonal antibodies (mAbs) is an effective intervention for various adverse reactions caused by vaccination and the unpredictable nature of emerging and bioterrorist-related infections. Currently, vaccinia immune globulin (VIG) is manufactured from vaccinia vaccine-boosted plasma; however, this production method is not ideal because of its limited availability, low specific activity, and risk of contamination with blood-borne infectious agents. To overcome the limitations of VIG production from human plasma, we isolated two human single-chain variable fragments (scFvs), (SC34 and SC212), bound to vaccinia virus (VACV), from a scFv phage library constructed from the B cells of VACV vaccine-boosted volunteers. The scFvs were converted to human IgG1 (VC34 and VC212). These two anti-VACV mAbs were produced in Chinese Hamster Ovary (CHO) DG44 cells. The binding affinities of VC34 and VC212 were estimated by competition ELISA to $IC_{50}$ values of $2{\mu}g/ml$ (13.33 nM) and $22{\mu}g/ml$ (146.67 nM), respectively. Only the VC212 mAb was proven to neutralize the VACV, as evidenced by the plaque reduction neutralization test (PRNT) result with a $PRNT_{50}$ of ~0.16 mg/ml (${\sim}1.07{\mu}M$). This VC212 could serve as a valuable starting material for further development of VACV-neutralizing human immunoglobulin for a prophylactic measure against post-vaccination complications and for post-exposure treatment against smallpox.

• Journal of Applied Biological Chemistry
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• v.65 no.4
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• pp.239-245
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• 2022

Although normal activation of platelets is important in the process of hemostasis, excessive or abnormal activation of platelets can lead to cardiovascular diseases. Therefore, the discovery of novel substances capable of regulating or inhibiting platelet activation may be helpful in the prevention and treatment of cardiovascular diseases. Artemether is a derivative of artemisinin, known as an active ingredient of Artemisia annua, which has been reported to be effective in treating malaria, and is known to function through antioxidant and metabolic enzyme inhibition. However, the role of artemether in platelet activation and aggregation and the mechanism of action of artemether in collagen-induced human platelets are not known until now. This study investigated the effects of artemether on platelet activation and thrombus formation induced by collagen. As a result, cAMP level was significantly increased by artemether, and VASP and IP3R, substrates of cAMP-dependent kinase, were phosphorylated. IP3R phosphorylation by Artemether inhibited Ca²⁺ recruitment into the cytoplasm, and phosphorylated VASP inhibited fibrinogen binding by inactivating αIIb/β3 located on the platelet membrane. Consequently, artemether inhibited thrombin-induced fibrin clot formation. Therefore, we propose that artemether can act as an effective prophylactic and therapeutic agent for cardiovascular diseases caused by excessive platelet activation and thrombus formation.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.402-407
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• 2023

The regulation of platelet aggregation is crucial for maintaining normal hemostasis, but abnormal or excessive platelet aggregation can contribute to cardiovascular disorders such as stroke, atherosclerosis, and thrombosis. Therefore, identifying substances that can control or suppress platelet aggregation is a promising approach for the prevention and treatment of these conditions. Artemisinin, a compound derived from Artemisia or Scopolia plants, has shown potential in various areas such as anticancer and Alzheimer's disease research. However, the specific role and mechanisms by which artemisinin influences platelet activation and thrombus formation are not yet fully understood. This study investigated the effects of artemisinin on platelet activation and thrombus formation. As a result, cAMP production were increased significantly by artemisinin, as well as phosphorylated VASP and IP₃R which are substrates to cAMP-dependent kinase by artemisinin in a significant manner. The Ca²⁺ normally mobilized from the dense tubular system was inhibited due to IP₃R phosphorylation from artemisinin, and phosphorylated VASP by artemisinin aided in inhibiting platelet activity via αIIb/β3 platelet membrane inactivation and inhibiting fibrinogen binding. Finally, artemisinin inhibited thrombin-induced thrombus formation. Therefore, we suggest that artemisinin has importance with cardiovascular diseases stemming from the abnormal platelets activation and thrombus formation by acting as an effective prophylactic and therapeutic agent.

• Applied Microscopy
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• v.34 no.1
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• pp.31-42
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• 2004

Acute respiratory distress syndrome (ARDS) is a kind of acute lung injury characterized by inflammatory disruption of alveolar-capillary barrier and notorious for its high mortality. Neutrophils cause cell damage through the production of free radicals, inflammatory mediators, and proteases in ARDS. $PLA_2$ might serve a primary regulatory role in the activation of neutrophils. This present study was performed to elucidate the effect of rutin known as $PLA_2$ inhibitor on ARDS induced by endotoxin. Endotoxin had increased lung myeloperoxidase (MPO) activity, BAL (bronchoalveolar lavage) protein content, numbers of neutrophils in BALF (bronchoalveolar lavage fluid) compared with those of control rat (p<0.001). In addition, histological evidence of lung injury was correlated with neutrophil influx into alveolar space and cerrous perhydroxide granules were found in lining of endothelial cell, alveolar type I, II cells. In contrast, pretreated group of rutin had significantly decreased all of the parameters (p<0.001). These data suggest that inhibition of $PLA_2$ is one step approach that block the process of ARDS. Accordingly, we conclude that rutin can be used as the prophylactic agent for ARDS on the bases of these experimental results.