• Pediatric Infection and Vaccine
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• v.7 no.1
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• pp.143-151
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• 2000

Purpose : The accuracy of bacteriologic diagnosis of beta-hemolytic streptococcal pharyngotonsillitis depends on the degree of carrier rate in that area where the throat swabs are obtained and the evaluation of serological T typing as an epidemiologic marker is important to understand epidemiology of streptococcal infection. The purpose of this study is to know the carrier rates of group A streptococcus in normal children form four different areas and to find out the epidemiologic characteristic in distribution of the serotypes for 3 years. Method : Throat swabs were obtained from the tonsillar fossa of normal school children in four different areas(Uljin, Seoul, Osan, Kunsan) from March to May 1996, in Uljin in April 1997, and in Uljin in April 1998. The samples were plated on a 5% sheep blood agar plate and incubated overnight at $37^{\circ}C$ before examination for the presence of beta-hemolytic colonies. All isolated beta-hemolytic streptococcus were grouped and serotyped by T agglutination. Results : The carrier rate of beta-hemolytic streptococci and group A streptococci in 1996 were 27.6%, 18.6% at Uljin; 16.4%, 2.7% at Seoul; 33.0%, 26.0% at Osan; 20.0%, 12.3% at Kunsan, respectively. Among 1,192 normal school children from 4 different areas, we obtained 179 strains of group A streptococci. Fifty two percent of the strains were typable by T agglutination in 1996. Common T-type in 1996 were NT, T1, T3, T2 at Uljin; T12, T25 at Seoul; NT, T6, T28 at Osan; T25, T4, NT, T5 at Kunsan, in decreasing order, respectively. At Uljin, T1, T3, T25 accounted for 69% of strains in 1996, T1, T12, T25 accounted for 70% in 1997, and T12, T4 accounted for 88% in 1998. Conclusion : Higher carrier rates were found in Uljin and Osan, where there are a lower population density with scanty of medical facilities compared with another areas. We supposed that low carrier rates is likely to be related to antibiotic abuse or some epidemiologic factor. The periodic and seasonal serotyping analysis is important in monitoring and understanding the epidemiologic patterns of group A streptococci.

• BMB Reports
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• v.41 no.2
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• pp.119-125
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• 2008

Our previous work confirmed that Sph2/LA1029 was a sphigomyelinase-like hemolyisn of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai. Characteristics of both hemolytic and cytotoxic activities of Sph2 were reported in this paper. Sph2 was a heat-labile neutral hemolysin and had similar hemolytic behavior as the typical sphingomyelinase C of Staphylococcus aureus upon sheep erythrocytes. The cytotoxic activity of Sph2 was shown in mammalian cells such as BALB/C mouse lymphocytes and macrophages, as well as human L-02 liver cells. Transmission electron microscopic observation showed that the Sph2 treated BALB/C mouse lymphocytes were swollen and ruptured with membrane breakage. They also demonstrated condensed chromatin as a high-density area. Cytoskeleton changes were observed via fluorescence confocal microscope in Sph2 treated BALB/C mouse lymphocytes and macrophages, where both cytokine IL-$1{\beta}$ and IL-6 were induced. In addition, typical apoptotic morphological features were observed in Sph2 treated L-02 cells via transmission electron microscope and the percentage of apoptotic cells did increase after the Sph2 treatment detected by flow cytometry. Therefore, Sph2 was likely an apoptosis-inducing factor of human L-02 liver cells.

• Journal of Life Science
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• v.20 no.6
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• pp.922-928
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• 2010

This study was carried out to develop safe and novel anticoagulation agents from oriental medicinal herbs. From 33 medicinal herbs, 40 different ethanol extracts were prepared according to place of origin or extraction parts, and anticoagulation activities were evaluated by determination of thrombin time (TT), prothrombin time (PT) and activated partial thromboplastin time (aPTT). The average water content and average extraction ratio for the medicinal herbs were $6.85{\pm}2.26%$ and $5.27{\pm}4.25%$, respectively. Evaluation of TT at various concentrations of the extract led to the selection of Mucuna birdwoodiana, Prunus armeniaca, Cacalia ainsliaeiflora, Cinnamonum aromaticum, and Rhus javanica Linneas potent antithrombosis medicinal herbs. Evaluation of PT and aPTT showed that the extracts of R.javanica Linne, M. birdwoodiana, and P. armeniaca have strong anticoagulation activities. Determination of hemolytic activities of 40 different ethanol extracts against human red blood cells, however, showed that only M. birdwoodiana, C. ainsliaeiflora, C. aromaticum, and R. javanica Linnehas strong anticoagulation activity without hemolytic activity at a concentration of 500 mg/ml. Our results suggest that oriental medicinal herbs, which are under a mass-production system, have potentialas a safe and novel source of anticoagulants, as well being a thrombin-specific and coagulation factor-specific inhibitor.

• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.1028-1032
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• 1999

Alpha toxin of S aureus has cytolytic activity respectively. This antigen has been received the most attention since it is a major virulence factor in pathogenesis of staphylococcal mastitis. Thus, alpha toxin has been focused as potential candidate of vaccine to minimize mastitis in cows. The purpose of this study was to develop a simple, efficient production and purification methods of sufficient amount of alpha toxin antigen from S aureus. Alpha toxin production measured by hemolytic activity was the highest at 18 hrs postinoculation in yeast extract culture medium supplemented with thiamine, nicotinic acid and casamino acid. Alpha toxin was purified by ammonium sulfate precipitation (65%) and ultrafiltration. Molecular weight of the toxin was 33 kDa in the analysis with SDS-PAGE. Conclusionally, when alpha toxin was included in the vaccine, the optimal harvest time of alpha toxin was at 18 hrs after inoculation in yeast extract medium supplemented with thiamine and nicotinic acid.

• Clinical and Experimental Pediatrics
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• v.58 no.7
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• pp.239-244
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• 2015

The complement system is part of the innate immune response and as such defends against invading pathogens, removes immune complexes and damaged self-cells, aids organ regeneration, confers neuroprotection, and engages with the adaptive immune response via T and B cells. Complement activation can either benefit or harm the host organism; thus, the complement system must maintain a balance between activation on foreign or modified self surfaces and inhibition on intact host cells. Complement regulators are essential for maintaining this balance and are classified as soluble regulators, such as factor H, and membrane-bound regulators. Defective complement regulators can damage the host cell and result in the accumulation of immunological debris. Moreover, defective regulators are associated with several autoimmune diseases such as atypical hemolytic uremic syndrome, dense deposit disease, age-related macular degeneration, and systemic lupus erythematosus. Therefore, understanding the molecular mechanisms by which the complement system is regulated is important for the development of novel therapies for complement-associated diseases.

• Childhood Kidney Diseases
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• v.17 no.1
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• pp.1-5
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• 2013

C3 glomerulonephritis (C3GN) is a recently described entity that shows a glomerulonephritis on light microscopy, bright C3 staining and the absence of C1q, C4, and immunoglobulins on immunofluorescence microscopy and mesangial and/or subendothelial electron-dense deposits on electron microscopy. The term 'C3 glomerulopathy' is often used to include C3GN and dense deposit disease (DDD), CFHR5 nephropathy, those of which result from dysregulation of the alternative pathway of complement. C3GN shares some aspects of atypical hemolytic uremic syndrome, MPGN, late stage of post infectious glomerulonephritis and other glomerulonephrtis. When C3GN is considered, measurement of serum complement proteins including C3, CFH, CFI, CFB and testing for the presence of C3 nephritic factor, anti-factor H autoantibodies are necessary. To screening for mutations, genes that encode complement regulators should be evaluated. This disorder equally affected all ages, both genders, and typically presented with hematuria and proteinuria. In both the short and long term, renal function remained stable in the majority of patients.

• Childhood Kidney Diseases
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• v.4 no.2
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• pp.136-143
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• 2000

Purpose : The hemolytic uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia thrombocytopenia, and acute renal failure. It is ole of tile most common cause of acute renal failure in children but few reports are available in Korea. Thus we investigated the 23 patients diagnosed as HUS during last 14 years. Method : We retrospectively investigated the etiologic factor, clinical manifestations laboratory findings, treatment modalities, and final outcomes of the patients. Then patients were divided into two groups according to outcome, md comparison was performed. Group A(8) comprised patients who progressed to end-stage renal disease or expired. Group B(15) comprised patients who completely recovered after dialysis treatment. Result The number of patients aged less than 4 years were 17; between 5 and 10 were 4 and more than 10 were 2. The gende ratio was M:F=2 : 1. The etiologic factors were as follows: acute gastroenteritis in 14 patients including 4 bloody diarrhea, upper respiratory tract infection in 7 patients, and 1 patient with herbal mediation. The overall mortality rate was 22$\%$: 2 patients died of US complications, 2 patients died of sepsis, and 1 patient died of pulmonary hemorrhage. Group A (Hb 4.8${\pm}$1.2 g/dL) showed lower value in hemoglobin than group B (Hb 6.3${\pm}$1.7 g/dL) during hospital stay (P< 0.05), And the time interval between tile disease onset and dialysis treatment was significantly longer in group A ($11.9{\pm}9.1\;days\;vs\;2.8{\pm}2.1\;days$) (P< 0.05). Conclusion : Overall mortality rate was 22$\%$. Low hemoglobin value and the prolonged time interval between the disease onset and dialysis treatment were related with poor prognosis. So early diagnosis and appropriate intensive care including dialysis treatment is essential to achieve better outcome in children.

• Korean Journal of Veterinary Research
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• v.30 no.3
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• pp.287-295
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• 1990

The purpose of this study was the examination for presence of pilus antigen, O serogroups, colicin production, antibiotic susceptibility and plasmid profiles among E coli isolated from diarrheal piglets and fattening pigs in Taegu province. Of 145 E coli isolated, 98 strains (67.4%) possesed pilus antigens which belonged to either K88 (47.6%), K99 (11.7%) or 987P (8.3%) types. Fifty-nine strains (40.7%) were classified into tenO serogroups and their types were O8 (22.0%), O20(16.9%), O141(15.3%), O9(10.2%), O45(10.2%), O139(8.5%), O064(6.8%), O149(5.0%), O157(3.4%), and O115(1.7%). Thirty-three strains (22.8%) were colicinogenic and 6 strains (4.1%) were hemolytic. One hundred and thirty-nine strains (95.9%) of 145 E coli isolates were resistant to ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, tetracycline, rifampicin and nalidixic acid, alone or in combination thereof. Ninety strains (64.7%) of 139 drug resistant strains carried R factor (R) which were transferable to the recipient by conjugation. In gel electrophoresis for the isolation of plasmid DNA, the number of plasmid DNA band varied from 2 to 11 in 16 E coli with pilus antigen. It's molecular weight ranged from 1.0 to 60.0 megadalton.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1253-1261
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• 2022

Staphylococcus aureus (S. aureus) infection causes dramatic harm to human health as well as to livestock development. As an important virulence factor, alpha-hemolysin (hla) is critical in the process of S. aureus infection. In this report, we found that bavachin, a natural flavonoid, not only efficiently inhibited the hemolytic activity of hla, but was also capable of inhibiting it on transcriptional and translational levels. Moreover, further data revealed that bavachin had no neutralizing activity on hla, which did not affect the formation of hla heptamers and exhibited no effects on the hla thermal stability. In vitro assays showed that bavachin was able to reduce the S. aureus-induced damage of A549 cells. Thus, bavachin repressed the lethality of pneumonia infection, lung bacterial load and lung tissue inflammation in mice, providing potent protection to mice models in vivo. Our results indicated that bavachin has the potential for development as a candidate hla inhibitor against S. aureus.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.872-879
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• 2015

Many strains of Bacillus cereus cause gastrointestinal diseases, and the closely related insect pathogen Bacillus thuringiensis has also been involved in outbreaks of diarrhea. The diarrheal diseases are attributed to enterotoxins. Sixteen reference strains of B. cereus and nine commercial and 12 reference strains of B. thuringiensis were screened by PCR for the presence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, bceT, entFM, and entS), one emetogenic gene (ces), seven hemolytic genes (hlyA, hlyII, hlyIII, plcA, cerA, cerB, and cerO), and a pleiotropic transcriptional activator gene (plcR). These genes encode various enterotoxins and other virulence factors thought to play a role in infections of mammals. Amplicons were successfully generated from the strains of B. cereus and B. thuringiensis for each of these sequences, except the ces gene. Intriguingly, the majority of these B. cereus enterotoxin genes and other virulence factor genes appeared to be widespread among B. thuringiensis strains as well as B. cereus strains.