• Title/Summary/Keyword: Experimental infection

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Microbial Risk Assessment in Treated Wastewater Irrigation on Paddy Rice Plot (하수처리수를 관개한 후 벼재배 시험구에 대한 미생물 위해성 평가)

  • Jung, Kwang-Wook;An, Youn-Joo;Jang, Jae-Ho;Jeon, Ji-Hong;Yoon, Chun-Gyeong
    • Korean Journal of Ecology and Environment
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    • v.38 no.2 s.112
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    • pp.225-236
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    • 2005
  • The protection of public health In wastewater reclamation and reuse is one of the most important issues. Monitoring data of Escherichia coli were collected from paddy rice plots in 2003 and 2004 experiments. Five treatments were used and each one was triplicated to evaluate the changes of E. coli: surface water, biofilter effluent (secondary level), UV-disinfected water and pond treatment. Microbial risk was quantified to assess human health risk by exposure to E. coli in paddy rice plots, which were irrigated with reclaimed wastewater. Beta-Poisson model was used to estimate the microbial risk of pathogen ingestion that may occur to farmer and neighbor children. Monte-Carlo analysis (10,000 trials) was used to estimate the risk characterization of uncertainty. In the following analysis, two scenarios were related to the reduction of risk against direct ingestion and exposure times. Scenarios A and B were assumed that the risk was 1,000 and 10,000 times lower than direct ingestion.'Golfers were assumed to be 0.001 L of reclaimed water by contact with balls and their cloths. Opportunity of contact in paddy rice field with pathogens was more frequent than handing golf balls, because of agricultural activity was practiced in ponded water in paddy rice culture. As a result of microbial risk assessment using total data of experimental period, risk value of E. coli in 2003 and 2004 experiment ranged from $10^{-5}$ to $10^{-8}$ and $10^{-4}$ to $10^{-8}$, respectively. The risk values in biofilter effluent irrigation was the highest, which is $10^{-4}$ in 2003 and $10^{-5}$ in 2004 experiments with scenario A. Ranges of $10^{-6}$ to $10^{-8}$ were considered at reasonable levels of risk for communicable disease transmission from environmental exposure and the risk value above $10^{-4}$ was considered to be attributable to the risk of infection. Irrigation with UV-disinfected water in the paddy field during the agricultural Period showed significantly lower microbial risk than others, and their levels of risk value were within the range of actual paddy rice field with surface water.

Epidemiology of central venous catheter related blood stream infections in pediatric patients (중심정맥 도관 관련 감염의 역학 고찰)

  • Kim, Jung Hyun;Eun, Ho Sun;Choi, Kyung Min;Kim, Dong Soo;Young, Dong Eun
    • Clinical and Experimental Pediatrics
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    • v.49 no.2
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    • pp.157-161
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    • 2006
  • Purpose : The purpose of this study is to investigate the pathogens of central venous catheter-related blood stream infections and search for the association among the insertion site, the duration and the underlying conditions with the prevalence of central venous catheter-related blood stream infections under 15 years old. Methods : A retrospective study was performed from Jan, 2003 to Dec, 2003 in Severance Hospital on 112 patients who undertook central venous catheter insertions. Results : We examined 112 patients who undertook central venous catheter insertion. The mean age of patients was $4.77{\pm}4.12$ years old. Coagulase negative Staphylococci was the most common organism of central venous catheter-related blood stream infections accounting for 33.9 percent, followed by Eenterococcus faecium(9.3 percent), and Staphylococcus aureus(7.5 percent), The most common insertion site was the right femoral vein, followed by the right jugular vein and the left femoral vein. The mean insertion period was $14.17{\pm}12.00$ days. Conclusion : Central venous catheter-related blood stream infections were not only related to the underlying conditions, but also to the insertion site. We need to study the clinical importance of coagulase negative Staphylococci as it is part of the normal flora of the skin. In future, more studies are needed to take preventive measures and improve treatment methods.

Effect of Synagis (palivizumab) prophylaxis on readmission due to respiratory syncytial virus in very low birth weight infants (극소 저체중 출생아에서 Synagis (palivizumab) 접종이 respiratory syncytial virus 감염으로 인한 재입원에 미치는 영향)

  • Park, Soo Kyoung;Jung, Yu Jin;Yoo, Hye Soo;Ahn, So Yoon;Seo, Hyun Joo;Choi, Seo Hui;Kim, Myo Jing;Jeon, Ga Won;Koo, Soo Hyun;Lee, Kyung-Hoon;Chang, Yun Sil;Park, Won Soon
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.358-364
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    • 2010
  • Purpose : The aim of this study was to determine the efficacy of $Synagis^{(R)}$ (palivizumab) in reducing the respiratory syncytial virus (RSV) readmission rate in very low birth weight infants (VLBWI ) and the subgroup that showed the most effective vaccination. Methods : We enrolled 350 VLBWI who had been discharged alive from the neonatal intensive care unit of Samsung Medical Center from January 2005 to December 2007 and were followed up for at least one year. A retrospective study based on medical records was performed for a period of one year after discharge. RSV readmission rate was investigated according to BPD (bronchopulmonary dysplasia, requiring oxygen at postnatal day 28) and $Synagis^{(R)}$ prophylaxis. We categorized the subgroups by the severity of BPD gestational age, and birth weight and compared the RSV readmission rates between subgroups. Results : Eleven VLBWI were readmitted. $Synagis^{(R)}$ prophylaxis resulted in a 86% reduction in the rate of readmission due to RSV infection (prophylaxis group, 0.7% and no prophylaxis group, 5.0%; P =0.02). Readmission rate in BPD patients was also reduced in the prophylaxis group (0.7% in the prophylaxis group vs. 5.2% in the no prophylaxis group, P =0.03). The readmission rate in patients without BPD was reduced in the prophylaxis group (0% in the prophylaxis group vs. 4.9% in the no prophylaxis group, P =1.00), but this was not statistically significant.Conclusion : $Synagis^{(R)}$ prophylaxis was effective at reducing RSV readmission in VLBWI. Its efficacy was verified irrespective of BPD, gestational age, or birth weight.

Clinical characteristics of acute lower respiratory tract infections due to 13 respiratory viruses detected by multiplex PCR in children (소아에서 13종 호흡기 바이러스에 의한 급성 하기도 감염의 임상 양상)

  • Lim, Jeong-Sook;Woo, Sung-Il;Baek, Yun-Hee;Kwon, Hyuk-Il;Choi, Young-Ki;Hahn, Youn-Soo
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.373-379
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    • 2010
  • Purpose : This study was performed to investigate the epidemiologic and clinical features of 13 respiratory viruses in children with acute lower respiratory tract infections (ALRIs). Methods : Nasopharyngeal aspirates were prospectively obtained from 325 children aged 15 years or less from May 2008 to April 2009 and were tested for the presence of 13 respiratory viruses by multiplex real-time-polymerase chain reaction (RT-PCR). Results : Viruses were identified in 270 children (83.1%). Co-infections with ${\geq}2$ viruses were observed in 71 patients (26.3 %). Respiratory syncytial virus (RSV) was the most common virus detected (33.2%), followed by human rhinovirus (hRV) (19.1%), influenza virus (Flu A) (16.9%), human metapneumovirus (hMPV) (15.4%), parainfluenza viruses (PIVs) (8.3%), human bocavirus (hBoV) (8.0%), adenovirus (ADV) (5.8%), and human coronavirus (hCoV) (2.2%). Clinical diagnoses of viral ALRIs were bronchiolitis (37.5%), pneumonia (34.5%), asthma exacerbation (20.9%), and croup (7.1%). Clinical diagnoses of viral bronchiolitis and pneumonia were frequently demonstrated in patients who tested positive for RSV, hRV, hMPV, or Flu A. Flu A and hRV were most commonly identified in children older than 3 years and were the 2 leading causes of asthma exacerbation. hRV C was detected in 14 (4.3%) children, who were significantly older than those infected with hRV A ($mean{\pm}SD$, $4.1{\pm}3.5$ years vs. $1.7{\pm}2.3$ years; P =0.009). hBoV was usually detected in young children ($2.3{\pm}3.4$ years) with bronchiolitis and pneumonia. Conclusion : This study described the features of ALRI associated with 13 respiratory viruses in Korean children. Additional investigations are required to define the roles of newly identified viruses in children with ALRIs.

Susceptibility tests of oral antibiotics including cefixime against Escherichia coli, isolated from pediatric patients with community acquired urinary tract infections (소아 원외 요로감염 환아에서 분리된 E. coli에 대한 cefixime을 포함한 경구 항생제의 감수성 연구)

  • Lee, Soo Young;Lee, Jung Hyun;Kim, Jong Hyun;Hur, Jae Kyun;Kim, Sun Mi;Ma, Sang Hyuk;Kang, Jin Han
    • Clinical and Experimental Pediatrics
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    • v.49 no.7
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    • pp.777-783
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    • 2006
  • Purpose : Urinary tract infection(UTI) is one of the most frequent infections in children. E. coli is the most frequent etiological micropathogen in pediatric community UTI, and E. coli has developed resistance to many antibiotics, highlighting the need for regular surveys of this organism resistant patterns in the community. The aim of this study was to determine the oral antibiotic susceptibility patterns of E. coli, isolated from pediatric patients with uncomplicated community acquired UTI. Methods : E. coli isolates, obtained from pediatric patients with uncomplicated community acquired UTI between October in 2004 to September in 2005. And minimal inhibitory concentrations(MICs) of oral aminopenicillins and beta-lactamase inhibnitors(ampicillin, amoxacillin, ampicillin-sulbactam), oral cephalosporins(cefaclor, cefixime) and sulfa drug(trimethoprime-sulfamethoxazole) were performed according to the National Committee for Clinical Laboratory Standards(NCCLS) guide line. Results : Total 211 organisms were isolated from pediatric out-patients with community UTI. E. coli was the most common organism(89 percent), followed by E. fecalis, Proteus species, S. aureus, M. morganii, and P. aeruginosa. The resistant rates of aminopenicillins and beta-lactamase inhibitors, cefaclor and sulfa drug to E. coli were very high. But, the resistant rate of cefixime was markedly low, and ESBL strains were isolated with small rates. Conclusion : Our study results suggest that aminopenicillins, cefaclor and sulfa drug may not be useful as first line empirical antibiotics to treat pediatric patients with community UTI in Korea. But, 3rd generation cephalosporin such as cefixime can be used as effective second line antibiotics after primary treatment failure, also may be useful as an empirical first line antibiotic. Finally, we conclude that a continuous surveillance study to monitor susceptibility patterns of E. coli in community UTI will be needed for the standard guide lines of empirical oral antibiotic treatment.

Clinical Usefulness of Rapid Antigen Test on the Diagnosis of Influenza (인플루엔자 진단을 위한 신속 항원검사의 유용성)

  • Kim, Jae Seon;Choi, Hyon Joo;Ahn, Young Min;Hwang, Young Ok
    • Clinical and Experimental Pediatrics
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    • v.48 no.12
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    • pp.1348-1353
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    • 2005
  • Purpose : Influenza is a respiratory disease which prevails widely every year and shows high morbidity and mortality among not only chronic invalids and the old, but also among infants and young children. To prevent community-acquired influenza infection, to facilitate prompt antiviral therapy and to avoid unnecessary use of antibiotics, an easy, rapid diagnostic method for the influenza virus is needed. We evaluated a lateral-flow immunoassay(QuickVue Influenza Test), compared to viral culture. Methods : During two consecutive years from Jan. 2004 to June 2004 and from Feb. 2005 to Jan. 2005, 408 patients who were suffering from fever, cough and/or sore throat and myalgia were enrolled in our study. A total of 408 patients were tested with $QuickVue^{(R)}$(Quidel Co., San Diego, USA) influenza rapid antigen test and virus cultures at the same time. Results : Of the 408 patients tested, children who showed positive results at the virus culture numbered 77; among them, 55(71.4 percent) were type A/H3N2 and 22(28.5 percent) were type B. QuickVue influenza test had a sensitivity of 71.4 percent and a specificity of 95.8 percent. The positive and negative predictive values were 79.7 percent and 93.5 percent, respectively. Conclusion : In our study, this test had comparable high sensitivity and high specificity and many advantages, such as being easy to perform and simple to interpret, and showing rapid results. If rapid influenza antigen tests are widely applied in the clinic, we can begin treatment more rapidly and reduce influenza complications and the abuse of antibiotics.

Atorvastatin and Fluvastatin Can Reduce IL-1β-induced Inflammatory Responses in Human Keratinocytes (Atorvastatin 그리고 fluvastatin 약물의 IL-1β-유도 염증반응 억제 효과)

  • Choe, Yeong-In;Moon, Kyoung Mi;Yoo, Jae Cheal;Byun, June-Ho;Hwang, Sun-Chul;Moon, Dong Kyu;Woo, Dong Kyun
    • Journal of Life Science
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    • v.31 no.4
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    • pp.418-424
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    • 2021
  • Skin inflammation (dermatitis) is caused by varying skin damage due to ultraviolet radiation and microbial infection. Currently prescribed drugs for dermatitis include anti-histamine and steroid drug classes that soothe inflammation. However, incorrect or prolonged use of steroids can cause weakening of skin barriers as well as osteoporosis. Therefore, treating dermatitis with a drug that has minimal side effects is important. Statins, also known as 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, are cholesterol-lowering drugs that have been widely treated for hyperlipidemia and cardiovascular diseases. Interestingly, recent studies have shown the anti-inflammatory effects of statins in both experimental and clinical models for of osteoarthritis. This study investigated the possible anti-inflammatory effects of atorvastatin and fluvastatin in human keratinocytes (HaCaT cells), which are crucial components of skin barriers. Stimulation of HaCaT cells with IL-1β increased the expression of the COX2 protein, a major player of inflammatory responses. However, this induction of the COX2 protein was downregulated by pretreatments with atorvastatin and fluvastatin. Treatment with IL-1ß-induced the upregulation of other inflammatory genes (such as iNOS and MMP-1) and these expressions were similarly lowered by these two statin drug treatments. Taken together, these results indicated that atorvastatin and fluvastatin can reduce IL-1β-induced inflammatory responses in HaCaT cells. In conclusion, the findings suggest that atorvastatin and fluvastatin can be potential modulators for ameliorating skin inflammation.

A COVID-19 Diagnosis Model based on Various Transformations of Cough Sounds (기침 소리의 다양한 변환을 통한 코로나19 진단 모델)

  • Minkyung Kim;Gunwoo Kim;Keunho Choi
    • Journal of Intelligence and Information Systems
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    • v.29 no.3
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    • pp.57-78
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    • 2023
  • COVID-19, which started in Wuhan, China in November 2019, spread beyond China in 2020 and spread worldwide in March 2020. It is important to prevent a highly contagious virus like COVID-19 in advance and to actively treat it when confirmed, but it is more important to identify the confirmed fact quickly and prevent its spread since it is a virus that spreads quickly. However, PCR test to check for infection is costly and time consuming, and self-kit test is also easy to access, but the cost of the kit is not easy to receive every time. Therefore, if it is possible to determine whether or not a person is positive for COVID-19 based on the sound of a cough so that anyone can use it easily, anyone can easily check whether or not they are confirmed at anytime, anywhere, and it can have great economic advantages. In this study, an experiment was conducted on a method to identify whether or not COVID-19 was confirmed based on a cough sound. Cough sound features were extracted through MFCC, Mel-Spectrogram, and spectral contrast. For the quality of cough sound, noisy data was deleted through SNR, and only the cough sound was extracted from the voice file through chunk. Since the objective is COVID-19 positive and negative classification, learning was performed through XGBoost, LightGBM, and FCNN algorithms, which are often used for classification, and the results were compared. Additionally, we conducted a comparative experiment on the performance of the model using multidimensional vectors obtained by converting cough sounds into both images and vectors. The experimental results showed that the LightGBM model utilizing features obtained by converting basic information about health status and cough sounds into multidimensional vectors through MFCC, Mel-Spectogram, Spectral contrast, and Spectrogram achieved the highest accuracy of 0.74.

Effect of Planting Date and Hybrid on the Agronomic Characteristics, Forage Production and Feed Value of Corn for Silage (파종시기 및 품종이 사일리지용 옥수수의 생육특성, 사초생산성 및 사료가치에 미치는 영향)

  • Bae, Myeong Jin;Chung, Sung Heon;Kim, Jong Duk
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.42 no.1
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    • pp.54-60
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    • 2022
  • The planting date of corn for silage has been delayed because of spring drought and double cropping system in Korea. This experiment was conducted to evaluate agronomic characteristics, forage production and feed value of corn at April and May in 2019. Experimental design was a split-plot with three replications. Planting dates (12 April and 10 May) were designated to the main plot, and corn hybrids ('P0928', 'P1543' and 'P2088') to the subplot. The silking days of the early planting date (12 April) was 79 days and that of the late planting date (10 May) was 66 days (p<0.0001), however, there were no significant differences among the corn hybrids. Ear height of the late planting date was higher than that of the early planting (p<0.05), while there were no significant differences in plant height of corn. Insect resistance at the early planting was lower than that of late planting (p<0.05), however, lodging resistance was no significant difference at planting date. The rice black streaked virus (RBSDV) infection of early planting was 3.7% and that of late planting was 0.3% (p<0.001). Dry matter (DM) contents of stover, ear and whole plant had significant difference at planting date (p<0.05). And differences in ear percentages were observed among the corn hybrids (p<0.01). And ear percentages of early maturing corn ('P0928') was higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date (p<0.01). DM and total digestible nutrients (TDN) yields had significant difference at planting date, however, there were no significant differences among the corn hybrids. DM and TDN yields at the late planting (21,678 kg/ha and 14,878 kg/ha) were higher than those of the early planting (13,732 kg/ha and 9,830 kg/ha). Crude protein content at the early planting date was higher than that of the late planting. Acid detergent fiber content of the late planting was lower than that of the early planting date (p<0.01), while there were no significant neutral detergent fiber content difference among the corn tested. Calculated net energy for lactation (NEL) and TDN at the early planting were higher than those of at the late planting (p<0.01). Results of this our study indicate that the late planting date (May) is better than early planting date (April) in forage yield and feed value of corn. Therefore, the delay of planting date by May was more suitable for use in cropping system.