• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.122-127
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• 2016

Methicillin-Resistant Staphylococcus aureus(MRSA) is a multidrug-resistant(MDR) strain. (+)-Usnic acid(UA) is uniquely found in lichens, and is especially abundant in genera such as Usnea and Cladonia. UA has antimicrobial activity against human and plant pathogens. Therefore, UA may be a good antibacterial drug candidate for clinical development. In search of a natural products capable of inhibiting this multidrug-resistant bacteria, we have investigated the antimicrobial activity of UA against 17 different strains of the bacterium. In this study, the effects of a combination of UA and permeable agents against MRSA were investigated. For the measurement of cell wall permeability, UA with concentration of Ethylenediaminetetraacetic acid(EDTA) was used. In the other hand, Sodium azide($NaN_3$) was used as inhibitors of ATPase. Against the 17 strains, the minimum inhibitory concentrations(MICs) of UA were in the range of $7.81-31.25{\mu}g/ml$. EDTA or $NaN_3$ cooperation against MRSA showed synergistic activity on cell wall. UA and in combination with EDTA and $NaN_3$ could lead to the development of new combination antibiotics against MRSA infection.

• Pediatric Infection and Vaccine
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• v.25 no.2
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• pp.91-100
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• 2018

Purpose: This study investigated the factors affecting the use of empirical antibiotics in febrile infants from 1 month to less than 3 months. Methods: We retrospectively reviewed the medical records of hospitalized previously healthy infants with fever in Pusan National University Children's Hospital from January 2010 to December 2016. Clinical features, laboratory findings and antibiotic therapy were analyzed. Respiratory viruses were identified by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) and were reported after 1-3 days. Enterovirus were identified by real time polymerase chain reaction (PCR) and were reported in several hours. Results: The 129 of 366 subjects used empirical antibiotics and 237 patients didn't used empirical antibiotics. Empirical antibiotics were used more frequently when the fever was longer before admission, respiratory symptoms and ill being appearances were present and C-reactive protein was elevated. The rate of readmission was low in the group not used empirical antibiotics. Most of the patients detected by enterovirus PCR in cerebrospinal fluid didn't used empirical antibiotics. The results of respiratory virus multiplex RT-PCR showed no difference in the use of empirical antibiotics. Conclusions: In our study, empirical antibiotic prescriptions were affected not respiratory virus multiplex RT-PCR but enterovirus PCR. If multiplex RT-PCR were reported more rapid turn around time, it will affect antibiotic use.

• Journal of Life Science
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• v.23 no.4
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• pp.602-608
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• 2013

The multifaceted role of chronic inflammation in multistep carcinogenesis has been extensively investigated and well documented. Periodontal diseases are associated with multifactorial agents, including bacterial endotoxins and the generation of an inflammatory response, indicating that poor oral health is associated with a variety of systemic diseases. The association between poor oral health, chronic inflammation, smoking, and increased alcohol consumption as risk factors for tumorogenesis is well established. More recently, associations between oral health and tooth loss and gastric, lung, and pancreatic cancers have been explored, with some studies pointing to smoking and oral health as a common link with an increased risk for malignant disease. In addition, epidemiological studies consistently indicate increased risks of various cancers with periodontal disease or poor oral condition caused by oral bacteria, which may activate alcohol- and smoking-related carcinogens locally or act through chronic inflammation. Appropriate oral care is vital in preventing cancer, as well as many other diseases. Thus, research on the correlation between oral care and periodontal inflammation and cancer is required. This review highlights the association between oral health and the risk of certain malignancies, such as periodontal disease-associated chemoprevention of inflammation" in this sentence.

• Journal of Society of Preventive Korean Medicine
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• v.16 no.3
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• pp.139-153
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• 2012

Objectives : NK cells are spontaneously cytotoxic lymphocytes. These are not only important parts in the first line of defence against bacterial and viral infections of outside, but they may also play a critical role in chronic viral diseases. NK cells kill their targets spontaneously, without the need for prior sensitization and class I MHC restriction by the regulation of cytolytic functions and secretion of a variety of cytokines, such as interleukin-12(IL-12), MCP-1, IL-6, TNF-${\alpha}$, IFN-${\gamma}$. In addition, macrophage and NK cells cooperate through the production of cell mediates. These cooperation and modulation are one of major factors to prevent for evading immune surveillance of cancer. Hence, it could be assumed that if any candidate to enhance activities of macrophage and NK cell, it is considered as a potentially useful agents against cancer. Methods : In our study, to investigate effect of fermented soybean extracts by Lactic acid bacteria (SFE, soybean fermented extracts) work on intestinal immune cell to maintain general immune modulating and anti-cancer activity. We analyzed NK cytotoxicity assay and gene expressions of cytokine related with macrophage and NK cell activity. Results : In vitro experiment, SFE was verified as safety material for cell toxicicty to tumor cell strain without any toxicity of tumor growth inhibition and various cell strain. Effects of macrophage activity stimulating directly by SFE measured induced cytokine. The studies showed that IL-12 production by stimulation of SFE depended on concentration from 0.16mg/mL to 0.63mg/mL with non toxicity to cell, and it was the best activity at 0.63mg/mL. Besides, the effective concentration of SFE producing TNF-${\alpha}$ is similar to IL-12, but it was the best activity at 1.25mg/mL. The level of MCP-1, IL-6 and IFN-${\gamma}$ depended on concentration from 0.16mg/mL to 10mg/mL, IFN-${\gamma}$ showed the best activity at the effective concentration of 0.63mg/mL. With the result of NK cell activity measurement, the spleen cell of mouse injected SFE had 1.5 times higher killing effect than non injected cell. Conclusions : The result of this studies is that Soybean fermetated extracts(SFE) has possibility to immune aided material for the function not only inhibition of microbial infection to macrophage but also activity of adaption immune and cellular immune system.

• Journal of Life Science
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• v.29 no.6
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• pp.712-723
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• 2019

Chemically synthesized compounds are widely used in oral hygiene products. However, excessively long-term use of these chemicals can cause undesirable side effects such as bacterial tolerance, allergy, and tooth discoloration. To solve these issues, significant effort is put into the search for natural antibacterial agents. The aim of this study was to assess the extracts of foreign native plants that inhibit the growth and biofilm formation of Streptococcus mutans. Among the 300 foreign plant extracts used in this study, Chesneya nubigena (D. Don) Ali extract had the highest antimicrobial activity relatively against S. mutans with a clear zone of 9 mm when compared to others. This plant extract also showed anti-biofilm activity and bacteriostatic effect (minimal bactericidal concentration [MBC], 1.5 mg/ml). In addition, the plant extracts of 19 species decreased the ability of S. mutans to form biofilm at least a 6-fold in proportion to the tested concentrations. Of particular note, C. nubigena (D. Don) Ali extract was found to inhibit biofilm formation at the lowest concentration tested effectively. Therefore, our results reveal that C. nubigena (D. Don) Ali extract is a potential candidate for the development of antimicrobial substitutes, which might be effective for caries control as well, as demonstrated by its inhibitory effect on the persistence and pathogenesis of S. mutans.

• Pediatric Infection and Vaccine
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• v.28 no.3
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• pp.149-159
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• 2021

Purpose: Antibiotic exposure during pregnancy may affect the fetus and newborn in many ways. This study investigated the impact of prenatal antibiotic exposure duration on neonatal outcomes in very preterm (VP) or very low birth weight (VLBW) infants. Methods: From September 2015 to December 2020, preterm infants with gestational age less than 32 weeks or with a BW less than 1,500 g who were admitted to the neonatal intensive care unit, and their mothers were enrolled. Prenatal antibiotic exposure was defined as antibiotics received by mothers before delivery, and the patients were categorized into the non-antibiotic group, short-duration (SD; ≤7 days) group, or long-duration (LD; >7 days) groups. Results: A total of 93 of 145 infants were exposed to prenatal antibiotics, among which 35 (37.6%) were in the SD group and 58 (62.4%) were in the LD group. Infants in the LD group had a significantly higher birth weight-for-gestational-age (BW/GA) Z-score than those in the non-antibiotic group, even after the adjustment for confounding factors (beta, 0.258; standard error, 0.149; P<0.001). Multivariate logistic regression analysis showed that prolonged prenatal antibiotic exposure was independently associated with death (adjusted odds ratio [aOR], 8.926; 95% confidence interval [CI], 1.482-53.775) and composite outcomes of death, necrotizing enterocolitis (NEC), and late-onset sepsis (LOS) (aOR, 2.375; 95% CI, 1.027-5.492). Conclusions: Prolonged prenatal antibiotic exposure could increase the BW/GA Z-score and the risk of death and composite outcomes of death, NEC, and LOS in VP or VLBW infants.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.382-390
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• 2020

This study was carried out to evaluate the antimicrobial effect of red ginseng (Panax ginseng C.A. Meyer) against several foodborne pathogens including Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger. The antimicrobial effect was determined by agar diffusion method using red ginseng extract, crude saponin and non-water-soluble fractions. Red ginseng extract showed antimicrobial effect against S. aureus, but not C. albicans or A. niger. The extract showed anti-bacterial activity at concentration above 30% against S. aureus, which cause both food poisoning and atophic dermatitis. Crude saponin showed antibacterial activity above 7.5% against the bacterium. However, the ginsenosides purified from crude saponin showed no antimicrobial activities at 100-200 ㎍/mL. To investigate the mode of growth inhibition, red ginseng extract and crude saponin were added to 0.85% NaCl solution containing S. aureus and then incubated at 35℃ for 12 h. The results showed that viable cells were rapidly reduced in above 10% concentration of red ginseng extract and above 2% of crude saponin, respectively. However, the crude saponin and red ginseng extract did not inhibit the bacterial cells completely at those same concentrations. On the other hand, whereas all non-water-soluble fractions showed inhibition zones above 10 mm against S. aureus, they showed no inhibition effects against E. coli, C. albicans or A. niger. The methanol fraction-1 (MF-1) showed the highest antibacterial activity against S. aureus, and the MIC (minimal inhibitory concentration) was 0.625 mg/mL. These results suggest that red ginseng extract, crude saponin and non-water-soluble fractions show selective antibacterial activity against S. aureus, and non-water-soluble fractions might be used as natural antibacterial agents.

• Pediatric Infection and Vaccine
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• v.28 no.2
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• pp.82-91
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• 2021

Background: The purpose of this study was to investigate the association between antibiotic use and the antimicrobial resistance of gram-negative bacteria isolated from blood cultures in a pediatric population. Methods: From January 2014 to June 2018, the antibiotic resistance pattern of Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa obtained from bacteremic patients aged ≤18 years hospitalized at Asan Medical Center Children's Hospital was analyzed and the parenteral antibiotic consumption data were retrieved. Results: During the study period, the blood culture was positive for K. pneumoniae (6.4%; 105/1,628), E. coli (5.6%; 91/1,628), P. aeruginosa (3.3%; 54/1,628), and A. baumannii (2.5%; 41/1,628), and the extended-spectrum antibiotic resistance rate of gram-negative bacteria was consistently high. The overall resistance rate of E. coli and K. pneumoniae to extendedspectrum cephalosporin was 49.3% and 54.4%, respectively. Carbapenem-resistant E. coli was first detected in 2014; its overall resistance rate to carbapenem was 5.3%. There was a linear correlation between the usage of 3rd generation cephalosporin and the resistance of A. baumannii (r²=0.96, P=0.004) and carbapenem usage and the resistance of K. pneumoniae (r²=0.79, P=0.045). Conclusions: A positive linear correlation was observed between antibiotic resistance and the corresponding antibiotic usage in 3rd generation cephalosporin resistant A. baumannii and carbapenem resistant K. pneumoniae. The judicious use of antibiotics in healthcare settings is important to minimize selection for extended-spectrum β-lactamase (ESBL) and carbapenem resistance in gram-negative bacteria.

• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.75-82
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• 2024

Purpose: As the coronavirus disease 2019 (COVID-19) pandemic ended, the number of patients with respiratory syncytial virus (RSV) pneumonia increased during the spring/summer of 2022. This study aimed to analyze the clinical features and antibiotic usage of children hospitalized for RSV pneumonia in a recently established general hospital in Sejong city. Methods: In this retrospective review, we included inpatients of the Pediatric Department of Chungnam National University Sejong Hospital diagnosed with RSV pneumonia between March 2022 and April 2023. Patients were divided into 2 groups: with and without antibiotic treatment. Demographic data, initial presentations, and clinical courses were reviewed. Results: A total of 116 patients with RSV pneumonia were hospitalized during this period, of which 102 were analyzed, excluding 14 with underlying diseases or who did not fall within the definition of pneumonia. The median age was 17 months. Diagnoses of bacterial infections (acute otitis media and sinusitis) were documented in 9.8% of cases. Intravenous (IV) antibiotics were administered in 46% of cases. The group receiving IV antibiotics showed higher inflammatory levels (C-reactive protein; CRP), more infiltration on initial chest X-rays, and longer fever duration. There was no difference in the length of hospitalization between the groups with and without IV antibiotics. Conclusions: This study showed a tendency for the attending physician to prescribe IV antibiotics to patients with longer fever duration, pulmonary infiltrations on the initial chest X-ray, and higher CRP levels. However, given the high rate of IV antibiotic usage compared to previous studies, care should be taken in antibiotic use.

• Journal of Life Science
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• v.25 no.10
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• pp.1156-1163
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• 2015

The present study investigated the immunomodulatory properties of four different medicinal plants in a cyclophosphamide-treated Balb/c mouse model. One of the four plants, Ulmus macrocarpa, showed partial resistance against immune suppression induced by cyclophosphamide. The bark of U. macrocarpa, commonly known as the Chinese elm, has been used as a pharmaceutical material in Korean traditional medicine to treat bacterial inflammation and induce wound healing. In this study, water extract of U. macrocarpa, named DEU-7, was used for its immunomodulating functional activity. DEU-7 increased the weight of the spleen and the number of splenocytes but did not significantly affect the liver, kidney, and thymus in vivo. A splenocyte viability assay confirmed that DEU-7 influenced ex vivo splenocyte survival. DEU-7 also increased the levels of cytokines, such as IL-2 and IL-4, and immunoglobulins, such as IgM, IgG, and IgA. These results indicated that DEU-7 is involved in the activation of T and B lymphocytes. In addition, DEU-7 was able to maintain the production of cytokines, such as TNF-α, IL-12, and IFN-γ, in the condition of cyclophosphamide-induced immune suppression, suggesting that DEU-7 activated innate immune cells, even under immune suppression. We concluded that DEU-7 aids immunological homeostasis, thereby preventing immune suppression, and aids both innate and adaptive immune response by maintaining the levels of various cytokines and immunoglobulins. Consequently, it is worth investigating the potential of DEU-7 as a supplemental source for immune-enhancing agents.