소아에서의 Quinolone계 항생제 사용의 가능성

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Xpert MTB/RIF assay for diagnosis of extrapulmonary tuberculosis in children: a systematic review and meta-analysis

BACKGROUND: The Xpert® MTB/RIF assay (Xpert; Cepheid, Sunnyvale, CA, USA) is a cartridge-based nucleic acid amplification assay for rapidly diagnosing tuberculosis and assessing antibiotic sensitivity. Although previous evidence supports the use of Xpert for diagnosing extrapulmonary tuberculosis (EPTB) in adults, information regarding the accuracy of Xpert for EPTB only in children is lacking. This meta-analysis was performed to assess the accuracy of Xpert for detecting EPTB in children. METHODS: We searched the MEDLINE, EMBASE, and Cochrane Infectious Diseases Group Specialized Register from January 1, 2010 to July 16, 2019 for studies of the diagnostic performance wherein Xpert was analyzed against cultures or composite reference standards for < 18-year-old children with EPTB. RESULTS: In only pediatric studies, 8 studies including 652 samples were selected. The pooled sensitivity and specificity of Xpert for all samples were 71% (95% CI 0.63-0.79) and 97% (95% CI 0.95-0.99), respectively. The area under the summary receiver operating characteristic (sROC) curve was 0.89. For lymph node tissues or aspirates, the pooled sensitivity and specificity of Xpert were 80% (95% CI 0.70-0.88) and 94% (95% CI 0.89-0.97), respectively; for cerebrospinal fluid (CSF), these values were 42% (95% CI 0.22-0.63) and 99% (95% CI 0.95-1.00), respectively. CONCLUSION: Overall, Xpert displayed high specificity but modest sensitivity across various samples for diagnosing pediatric EPTB compared to the composite reference standard. Xpert sensitivity varied with the sampling site and was especially lower in CSF samples. Positive Xpert results may be considered to indicate a presumptive case of pediatric EPTB, whereas negative test results indicate that the possibility of pediatric EPTB should not be excluded.ope

The Causative Organisms of Pediatric Bacterial Meningitis: A Single Center Experience from 1996 to 2005

Purpose : We investigated the causative organisms of bacterial meningitis by age distribution from 1996 to 2005. Methods : Retrospective data were obtained from the medical records with diagnosis of bacterial meningitis or neonatal meningitis from 1996 through 2005. A case was defined by isolation of organism or detection of its antigen by latex agglutination from cerebrospinal fluid. Results : A total of 46 cases(27 neonates and 19 children) were identified. 15 of 27 episodes(55.6%) of neonatal meningitis had a concomitant-positive blood culture. Group B streptococci were the most common bacterial causes of neonatal meningitis(44.4%). Nine of 12 episodes(75.0%) were late-onset infections in neonatal meningitis caused by group B streptococci. 16 of 19 children(84.2%) with bacterial meningitis beyond the neonatal period were younger than 5 years of age(median age, 23 months). Of 19 cases, 8 infections were with Streptococcus pneumoniae, 8 were with Haemophilus influenzae and 3 were with Neisseria meningitidis. Since 2001 there was no case of meningococcal meningitis in this study. Conclusion : In neonates group B streptococci are the most common causative organisms of bacterial meningitis, especially late-onset infections. In infants and young children, the predominant causes of bacterial meningitis are H. influenzae and S. pneumoniae; meningitis caused by the former are likely to decrease after the introduction of the conjugate vaccine for H. influenzae type b.ope

Genetic structures of invasive Streptococcus pneumoniae isolates from Korean children obtained between 1995 and 2013

BACKGROUND: Understanding the population genetics of pneumococci will allow detection of changes in the prevalence of circulating genotypes and evidence for capsular switching. We aimed to analyze the genetic structure of invasive pneumococcal isolates obtained from children before and after the use of pneumococcal conjugate vaccines (PCVs) in Korea. METHODS: A total of 285 invasive pneumococcal isolates were analyzed using serotyping, multilocus sequence typing, and antimicrobial susceptibility testing. We classified the isolation year to pre-PCV7 (1995-2003; n = 70), post-PCV7 (2004-2010; n = 142), and post-PCV13 (2011-2013; n = 73) periods. RESULTS: Of the 10 clonal complexes (CCs), antibiotic-resistant international clones, CC320 (31.6%), CC81 (14.7%), and CC166 (6.7%) were the main complexes. Serotype 19A was the main serotype of CC320 throughout the periods. Serotypes of CC81 mainly comprised of 23F (53.3%) in pre-PCV7 period and replaced by non-vaccine types (NVTs; 6C [10%], 13 [30%], 15A [40%], and 15B/C [20%]) in post-PCV13 period. The main serotype responsible for CC166 also changed from 9 V (80%) in pre-PCV7 to NVT 11A (50%) in post-PCV13 periods. Non-susceptibility to penicillin (42.3%) was the highest in CC320, increasing from 0 to 76%. CONCLUSION: The genetic structures of invasive pneumococcal isolates in Korean children have changed concomitantly with serotype after the implementation of PCVs.ope

Juvenile rheumatoid arthritis

The diagnosis of juvenile rheumatoid arthritis (JRA) is based on patient's age at disease onset, symptom duration, gender, and clinical manifestations. JRA is of unknown origin, begins under the age of 16, and persists for a minimum of 6 weeks. JRA is categorized into three principal types, systemic, oligoarticular and polyarticular. Infection, other connective tissue diseases, malignancy, trauma, and immunodeficiency are discussed as differential diagnoses for JRA. Because of joint damage, focusing on early diagnosis and intervention, a vigorous initial therapeutic approach must be taken in patients who have poor prognostic factors. A multidisciplinary team approach is also important for the care of patients with JRA.ope

Apoptosis of Peripheral Blood Mononuclear Cells in Different Ages of Normal Children

Purpose : To survive in an ecological environment, an individual must develop immunity to various antigens. Therefore, populations of peripheral blood mononuclear cells(PBMC) in humans change continuously with growth. The object of this study is to evaluate the apoptosis of peripheral blood mononuclear cells(PBMC) in normal children of different ages. Methods : PBMC were isolated from the study groups. Ten cord blood samples of normal babies, 10 blood samples of normal children each from 4 different age groups(0-1, 2-5, 6-10, 11-15 year- old and adult), and 20 from normal adults were included in this study. After 24 and 48 hrs incubation in RPMI1640 media containing 10% fetal calf serum, cells were stained with Annexin V and PI and then analyzed with FACScan flowcytometer. Results : Cord blood mononuclear cells showed the lowest percentage of apoptosis compared to other age groups. PBMC isolated from the 0-1 year-old normal children showed the highest percentage of apoptosis, and the percentage of apoptosis decreased with increase of age. After the age of 10, the percentage of PBMC apoptosis was the same as that of adults. Conclusion: The differences in the percentage of PBMC apoptosis with different age groups might be from immunologically different state of the hosts with different age. This result could be a useful reference data for the study of apoptosis in pediatric disease in the future.ope

Etiology of Invasive Bacterial Infections in Immunocompetent Children in Korea (2006-2010): a Retrospective Multicenter Study

BACKGROUND: Invasive bacterial infections in apparently immunocompetent children were retrospectively analyzed to figure causative bacterial organisms in Korea. METHODS: A total of 947 cases from 25 university hospitals were identified from 2006 to 2010 as a continuance of a previous 10-year period study from 1996 to 2005. RESULTS: Escherichia coli (41.3%), Streptococcus agalactiae (27.7%), and Staphylococcus aureus (27.1%) were the most common pathogens in infants /= 5 years of age, S. aureus (62.8%) was the predominant pathogen, followed by Salmonella species (12.4%) and S. pneumoniae (11.5%). Salmonella species (43.0%) was the most common cause of bacteremia without localizing signs in this group. The relative proportion of S. aureus increased significantly over the 15-year period (1996-2010) in children >/= 3 months of age (P /= 3 months of age groups (P < 0.001). CONCLUSION: S. agalactiae, E. coli, S. pneumoniae, and S. aureus are common etiologic agents of invasive bacterial infections in Korean children.ope

승용 디젤 엔진의 과도운전 시 배기 배출물 특성

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부, 2014. 2. 민경덕.As concerns about global environment issues have been becoming more serious, emission regulations, especially for automotive industries, have been continuously strengthened. For example, the current emission legislation is EURO-5b but the upcoming regulation, EURO-6, mandates reduction of NOx emissions by 55.6 % compared to the current standard while maintaining the same level of PM emissions. However, despite all the efforts to cut-down the emission level, the real world emission level has not dropped down much. This is due to the fact that the emission test cycle does not represent real-life driving conditions very well. As a result, emissions characteristics during transient operation are drawing more attention from automotive engineers. Therefore, in this research, emissions characteristics of light-duty Diesel engines during transient operation were studied. In order to measure NOx and PM emissions at both steady and transient states, Cambustions DMS-500 and CLD-500 were used along with Horibas exhaust gas analyzer. In addition, an EGR estimation model was adopted to measure EGR rates at transient states. For the first acceleration part of EUDC, transient NO emissions were lower than that of steady states due to increased EGR rate caused by higher boost pressure as a result of turbo-lag from a VGT. As EGR or boost pressure were matched, discrepancy in NO emissions between steady and transient states was disappeared. The opposite phenomenon was true for PM emissions considering NOx-PM trade-off. Also, an emission peak was observed for PM emissions due to instantaneously richer mixture yielded by delay in response of the amount of air. For deceleration, exactly opposite trend was found except that there was no emission peak. Furthermore, from post EURO-6 onward, harsher transient operation is going to be included in the emissions test cyclehence, it is crucial to study emissions characteristics at sudden and rapid acceleration such as tip-in which frequently occurs at over-taking. As for tip-in, steady state NO emissions were higher than that of transient NO emissions. However, unlike normal transient operation, NO peak was observed for tip-in acceleration due to difference in the amount of air caused by turbo-lag of a VGT. Also, a PM emission peak was observed for tip-in operation but the order of magnitude was so small compared to the peak level for the conventional acceleration case. In addition, as vehicles operate under various environment temperature, intake temperature was varied to simulate both cold and hot conditions. When different surrounding temperatures rather than the ambient condition were applied, EGR was no longer supplied causing drastic increase in NO emissions while almost zero PM emissions were observed. Also, no emission peak was observed under non-ambient temperature.Acknowledgements i Abstract ii List of Tables vii List of Figures viii Acronym xi Chapter 1. Introduction 1 1.1 Research Background and Literature Review 1 1.2 Objective 5 Chapter 2. Experimental Setup and Condition 6 2.1 Experimental Setup 6 2.2 Experimental Condition 10 Chapter 3. Experimental Result and Discussion 18 3.1 NEDC transient and steady state comparison 18 3.1.1 Acceleration 18 3.1.2 Deceleration 32 3.1.3 Different environment temperature 36 3.1 Tip-in operation 39 3.1.1 Ambient operation 39 3.1.2 Different environment temperature 45 Chapter 4. Conclusion 48 Reference 51 초 록 54Maste

A clinical study of the acute respiratory distress syndrome in children

Purpose: The acute respiratory distress syndrome(ARDS), an acute form of severe alveolar-capillary injury evolving after a direct or indirect lung insult is thought to be a common cause of respiratory failure though not many clinical studies on the subject have been made yet. Methods: Between January 1992 and December 2001, we conducted a retrospective study on 33 children who fulfilled the definition of the ARDS recommended by the American-European consensus conference in 1994 Results: A total of 33 patients(20 boys and 13 girls) were selected. Their age ranged from 4 months to 12 years with seven children younger than 1 year. The overall mortality rate was 78.8% and no significant difference was noted based on age or sex. Concerning seasonal variation, incidence of the ARDS increased in spring, especially in May(21.2%). Pneumonia(66.7%) was found to be the most common risk factor of the ARDS followed by sepis(24.2%) and aspiration(3.0%). In immune compromised children(six cases), including a recipient of bone marrow transplantation, the mortality rate was 100%. Compared with children with multiple organ failure recording a 83.3% mortality rate, those with isolated respiratory failure, showed a lower mortality rate of 33.3%, although stastistically insignificant. Between survivor and non-survivor groups, significant difference were shown in hematocrit, PaO₂, PaCO₂, PEEP, and PaO₂/FiO₂ on the seventh day after the onset of the ARDS. Conclusion: According to our study, respiratory failure proved to have a great effect on mortality rate in the ARDS. More aggressive intervention and further studies on this subject should be done to improve the survival rate.ope

Apoptosis of Cord Blood Mononuclear Cells Infected with Enterovirus

Purpose : To evaluate apoptosis of cord blood mononuclear cells(CBMC) infected with enterovirus. Methods : Cord blood was obtained from 20 neonates which were delivered vaginally without any complications. Cord blood mononuclear cells(CBMC) were isolated, and after 24h and 48h incubation, cells were stained with Annexin V and Propidium Iodide and were analyzed with FACScan flowcytometer. CBMCs were also incubated with enterovirus and ■-INF. mRNA expression of FasL was evaluated with RT-PCR. Results : The mean rate of apoptosis of CBMC 24 hr after culture with virus showed no definite increase compared to that of culture only group. The mean rate of apoptosis in the culture group with ■-INF was higher than that of culture with virus group(P<0.01) but was not different from the group cultured with virus and ■-INF simultaneously. These findings were also seen in 48- hours-cultured groups. mRNA of CBMC of the groups cultured with ■-INF expressed FasL. Conclusion : The upregulated apoptosis of peripheral lymphocytes in patients with aseptic meningitis may be not due to enterovirus infection directly, but due to some mediators such as ■-INF from immune cells released through enteroviral infection.ope