Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Emerg Microbes Infect ; 9(1): 2588-2596, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33138739

RESUMEN

ABSTRACT As another wave of COVID-19 outbreak has approached in July 2020, a larger scale COVID-19 pediatric Asian cohort summarizing the clinical observations is warranted. Children confirmed with COVID-19 infection from the Republic of Korea, the Hong Kong Special Administrative Region (HKSAR) and Wuhan, China, during their first waves of local outbreaks were included. Their clinical characteristics and the temporal sequences of the first waves of local paediatric outbreaks were compared. Four hundred and twenty three children with COVID-19 were analyzed. Wuhan had the earliest peak, followed by Korea and HKSAR. Compared with Korea and Wuhan, patients in HKSAR were significantly older (mean age: 12.9 vs. 10.8 vs. 6.6 years, p < 0.001, respectively) and had more imported cases (87.5% vs. 16.5% vs. 0%, p < 0.001, respectively). The imported cases were also older (13.4 vs. 7.6 years, p < 0.001). More cases in HKSAR were asymptomatic compared to Korea and Wuhan (45.5% vs. 22.0% vs. 20.9%, p < 0.001, respectively), and significantly more patients from Wuhan developed fever (40.6% vs. 29.7% vs. 21.6%, p=0.003, respectively). There were significantly less imported cases than domestic cases developing fever after adjusting for age and region of origin (p = 0.046). 5.4% to 10.8% of patients reported anosmia and ageusia. None developed pediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PMIS-TS). In general, adolescents were more likely to be asymptomatic and less likely to develop fever, but required longer hospital stays. In conclusion, majority patients in this pediatric Asian cohort had a mild disease. None developed PIMS-TS. Their clinical characteristics were influenced by travel history and age.

2.
JAMA Pediatr ; 2020 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-32857112

RESUMEN

Importance: There is limited information describing the full spectrum of coronavirus disease 2019 (COVID-19) and the duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection in children. Objective: To analyze the full clinical course and the duration of SARS-CoV-2 RNA detectability in children confirmed with COVID-19 in the Republic of Korea, where rigorous public health interventions have been implemented. Design, Setting, and Participants: This case series of children with COVID-19 was conducted in 20 hospitals and 2 nonhospital isolation facilities across the country from February 18, 2020, to March 31, 2020. Children younger than 19 years who had COVID-19 were included. Exposures: Confirmed COVID-19, detected via SARS-CoV-2 RNA in a combined nasopharyngeal and oropharyngeal swab or sputum by real-time reverse transcription-polymerase chain reaction. Main Outcomes and Measures: Clinical manifestations during the observation period, including the time and duration of symptom occurrence. The duration of SARS-CoV-2 RNA detection was also analyzed. Results: A total of 91 children with COVID-19 were included (median [range] age, 11 [0-18] years; 53 boys [58%]). Twenty children (22%) were asymptomatic during the entire observation period. Among 71 symptomatic cases, 47 children (66%) had unrecognized symptoms before diagnosis, 18 (25%) developed symptoms after diagnosis, and only 6 (9%) were diagnosed at the time of symptom onset. Twenty-two children (24%) had lower respiratory tract infections. The mean (SD) duration of the presence of SARS-CoV-2 RNA in upper respiratory samples was 17.6 (6.7) days. Virus RNA was detected for a mean (SD) of 14.1 (7.7) days in asymptomatic individuals. There was no difference in the duration of virus RNA detection between children with upper respiratory tract infections and lower respiratory tract infections (mean [SD], 18.7 [5.8] days vs 19.9 [5.6] days; P = .54). Fourteen children (15%) were treated with lopinavir-ritonavir and/or hydroxychloroquine. All recovered, without any fatal cases. Conclusions and Relevance: In this case series study, inapparent infections in children may have been associated with silent COVID-19 transmission in the community. Heightened surveillance using laboratory screening will allow detection in children with unrecognized SARS-CoV-2 infection.

3.
Int J Infect Dis ; 99: 199-203, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32717398

RESUMEN

OBJECTIVES: In Korea, the National Immunization Program provided trivalent inactivated influenza vaccines (IIV3) to all children aged 6-59 months during the 2017-2018 season. In this study, we aimed to evaluate the vaccine effectiveness (VE) of IIV3 in children during the 2017-2018 season. METHODS: Children aged 6-59 months who were tested for influenza for their acute respiratory illness in four hospitals during the 2017-2018 influenza season were included. We estimated the VE of IIV3 by test-negative case-control design based on the rapid influenza diagnostic test (RIDT) or reverse transcription polymerase chain reaction (RT-PCR) test results. RESULTS: A total of 4738 children were included in this study. The number of laboratory-confirmed influenza cases was 845 (17.8%), and there were 478 cases of influenza A and 362 cases of influenza B. The adjusted VE based on RT-PCR was 53.4% (95% CI, 25.3-70.5) against any influenza, 68.8% (95% CI, 38.7-84.1) against influenza A, and 29.7% (95% CI, -35.1 to 61.8) for influenza B. The adjusted VE based on RIDT was 14.8% (95% CI, -4.4 to 30.0) against any influenza, 24.2% (95% CI, 3.1-40.2) against influenza A, and -5.1% (95% CI, -42.6 to 21.4) against influenza B. Age-specific VE based on RT-PCR against any influenza was 44.1% (95% CI, -0.2 to 67.8) in children aged 6 months to 2 years and 59.3% (95% CI, 8.8-81.9) in children aged 3-<5 years. CONCLUSION: Our results suggest moderate protection (53.4%) of IIV3 against RT-PCR laboratory-confirmed influenza in children in the 2017-2018 influenza season. However, the RIDT hampered the validity to assess VE during influenza season. Caution is needed when interpreting an RIDT-based test negative design influenza VE study.

4.
J Korean Med Sci ; 35(24): e224, 2020 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-32567260

RESUMEN

Coronavirus disease 2019 (COVID-19) has resulted in an ongoing pandemic; however, the socioeconomic burden of COVID-19 treatment in the pediatric population remains unclear. Thus, the aim of this study was to determine the hospitalization periods and medical costs among children with COVID-19. In total, 145 billing statements for pediatric patients receiving healthcare services because of COVID-19 from February 1, 2020 to March 31, 2020 were used. The study showed that individual treatment costs for children with COVID-19 are approximately USD 2,192 under the Korean National Health Insurance Service System. This study revealed the differences in cost among age groups, determined by the type of hospital wherein admission occurred, as a trend of increasing age, increasing hospitalization time, and increasing cost was observed. Tailored COVID-19 treatment strategies by age group may lower costs and increase the effectiveness of resource allocation.


Asunto(s)
Infecciones por Coronavirus/economía , Hospitalización/economía , Pandemias/economía , Neumonía Viral/economía , Adolescente , Betacoronavirus , Niño , Preescolar , Infecciones por Coronavirus/tratamiento farmacológico , Humanos , Lactante , Recién Nacido , Tiempo de Internación/economía , Programas Nacionales de Salud/economía , Neumonía Viral/tratamiento farmacológico , República de Corea/epidemiología , Adulto Joven
5.
J Microbiol Immunol Infect ; 53(1): 179-182, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31607574

RESUMEN

This article reports five invasive Group B streptococcal (GBS) infections that occurred in a neonatal intensive care unit for about 3 months. This outbreak might have been associated with a prolonged GBS colonized infant and adjacent environmental contaminations. Infection control interventions prevented the additional spread of GBS infections.


Asunto(s)
Portador Sano/transmisión , Brotes de Enfermedades , Infecciones Estreptocócicas/transmisión , Streptococcus agalactiae/fisiología , Bacteriemia/microbiología , Edad Gestacional , Humanos , Recién Nacido , Control de Infecciones/métodos , Unidades de Cuidado Intensivo Neonatal , Meningitis/microbiología , Infecciones Estreptocócicas/sangre , Infecciones Estreptocócicas/complicaciones
6.
Pediatr Gastroenterol Hepatol Nutr ; 22(6): 511-517, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31777716

RESUMEN

Purpose: On the basis of evidence, we aimed to reevaluate the necessity of the empirical proton pump inhibitor (PPI) trial for children with suspected gastroesophageal reflux disease (GERD). Methods: We analyzed the frequency of GERD in 85 school-age children with gastroesophageal reflux (GER) symptoms, who received 24-hour esophageal pH monitoring and/or upper endoscopy. According to the reflux index (RI), the children were classified into normal (RI <5%), intermediate (5%≤ RI <10%), or abnormal (RI ≥10%) groups. Results: Fifty six were female and 29 were male. Their mean age was 12.6±0.5 (±standard deviation) years (range: 6.8-18.6). The RI analysis showed that the normal group included 76 patients (89.4%), the intermediate group included 6 patients (7.1%), and the abnormal group included 3 patients (3.5%). The DeMeester score was 5.93±4.65, 14.68±7.86 and 40.37±12.96 for the normal, intermediate and abnormal group, respectively (p=0.001). The longest reflux time was 5.56±6.00 minutes, 9.53±7.84 minutes, and 19.46±8.35 minutes in the normal, intermediate, and abnormal group, respectively (p=0.031). Endoscopic findings showed reflux esophagitis in 7 patients. On the basis of the Los Angeles Classification of Esophagitis, 5 of these patients were included in group A, 1 patient, in group B and 1 patient, in group C. Conclusion: The incidence of GERD was very low in school-age children with GER symptoms. Therefore, injudicious diagnostic PPI trials would be postponed until the actual prevalence of GERD is verified in future prospective studies.

7.
Open Forum Infect Dis ; 6(5): ofz210, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31139678

RESUMEN

We identified a healthcare-associated infection of severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV), transmitted through direct blood contact with an index case. Following further epidemiological and clinical investigations, we identified SFTSV seropositivity in 2 healthcare workers and 2 family members, who were positive for anti-SFTSV immunoglobin G. It is important to prevent SFTSV transmission by early diagnosis of SFTS and universal precautions.

8.
Microb Drug Resist ; 25(4): 577-581, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30484744

RESUMEN

Aims: Although the cases of macrolide-resistant Mycoplasma pneumoniae (MRMP) have been increasing substantially among children, there are very few studies that have focused on MRMP in adults. This study aimed to investigate the prevalence and clinical features of community-acquired pneumonia (CAP) caused by MRMP from adults in Jeju Island, Korea. Methods: We retrospectively recruited adult patients with CAP in whom M. pneumoniae infections had been confirmed for a 7-year period. Macrolide resistance was determined by identifying a mutation in the 23S rRNA gene using PCR. Results: In total, 70 subjects were included. Their mean age was 46.1 years and 36 (51.4%) were women. Only two isolates (2.9%) carried macrolide resistance mutations in the 23S rRNA gene, and all the mutations were A2063G transitions. No significant differences were observed in age, comorbidities, symptoms, duration of fever, and length of hospital stay between the MRMP and macrolide-sensitive Mycoplasma pneumoniae groups. The number of involved pulmonary lobes was greater in the MRMP group (3.50 vs. 1.44, p = 0.008). Conclusion: The prevalence of CAP caused by MRMP was relatively low in adults in Jeju Island. Patients with MRMP pneumonia tended to have multilobar pneumonic infiltrates.


Asunto(s)
Antibacterianos/farmacología , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , Macrólidos/farmacología , Mycoplasma pneumoniae/efectos de los fármacos , Neumonía por Mycoplasma/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Farmacorresistencia Bacteriana/efectos de los fármacos , Farmacorresistencia Bacteriana/genética , Femenino , Humanos , Islas/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana/métodos , Persona de Mediana Edad , Mutación/efectos de los fármacos , Mutación/genética , Mycoplasma pneumoniae/genética , Neumonía por Mycoplasma/tratamiento farmacológico , Neumonía por Mycoplasma/microbiología , Prevalencia , ARN Ribosómico 23S/genética , República de Corea/epidemiología , Estudios Retrospectivos , Adulto Joven
9.
Yeungnam Univ J Med ; 35(1): 70-75, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-31620573

RESUMEN

Background: Otitis media with effusion (OME) is defined as middle ear effusion without acute signs of infection. OME usually resolves spontaneously; however, persistent OME may require the insertion of a ventilation tube. This study investigated risk factors for persistent OME in children who undergo ventilation tube insertion. Methods: Children who were admitted to undergo ventilation tube insertion at Jeju National University Hospital between August 2015 and July 2016 were enrolled as the case group. Healthy children without persistent OME from August 2016 to July 2017 were enrolled as the control group. Baseline characteristics and predisposing factor data were collected using an interview questionnaire. Middle ear fluids were collected from the case group. Results: A total of 31 patients underwent ventilation tube insertion. The mean age of the case group was 4.53 years, with a male-to-female ratio of 21:10. Twenty-nine (93.5%) children attended a daycare center, and 21 (67.7%) had experience with bottle feeding. Fifteen (48.4%) children in the case group and 3 (9.7%) in the control group first attended a daycare center at <1 year of age (odds ratio=9.96; 95% confidence interval=2.44-39.70; p=0.001). No bacteria were found in middle ear fluid collected from the 31 operated children. Nasopharyngeal bacterial colonization was found in 13 (41.9%) and 17 (54.8%) children in the case and control groups, respectively. Conclusion: Earlier attendance at a daycare center was the only predisposing factor for ventilation tube insertion in our study. The aseptic nature of middle ear fluids found in children with OME highlights the efficacy of antimicrobial use.

10.
J Korean Med Sci ; 32(10): 1642-1646, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28875608

RESUMEN

Mycoplasma pneumoniae is the major pathogen of community-acquired pneumonia in children. The prevalence of macrolide-resistant M. pneumoniae (MRMP) is important owing to the limited alternative therapies for children. We analyzed 111 M. pneumoniae obtained from 107 children admitted for lower respiratory tract infection at Jeju National University Hospital between 2010 and 2015. Macrolide resistance of M. pneumoniae was searched for using polymerase chain reaction (PCR) and sequencing. Of 107 clinical M. pneumoniae, 11 (10.3%) carried macrolide resistance mutations in the 23S rRNA gene. All macrolide resistance mutations were A2063G transitions. We found an acquired A2063G mutation of M. pneumoniae from a patient during macrolide treatment. Patients' characteristics and clinical severity did not differ between those with MRMP and macrolide-sensitive M. pneumoniae, with the exception of frequent pleural effusion in the MRMP group. The prevalence of MRMP (10.3%) in Jeju Island was relatively lower than those of surrounding countries in East Asia. Previous antimicrobial usage and timing of diagnostic test should be considered when determining of macrolide resistance of M. pneumoniae.


Asunto(s)
Antibacterianos/uso terapéutico , Farmacorresistencia Bacteriana/genética , Macrólidos/uso terapéutico , Mycoplasma pneumoniae/genética , Neumonía por Mycoplasma/tratamiento farmacológico , Infecciones del Sistema Respiratorio/diagnóstico , Niño , Preescolar , Femenino , Humanos , Masculino , Mutación , Mycoplasma pneumoniae/aislamiento & purificación , Nasofaringe/microbiología , Neumonía por Mycoplasma/diagnóstico , Neumonía por Mycoplasma/microbiología , Neumonía por Mycoplasma/patología , Reacción en Cadena de la Polimerasa , Prevalencia , ARN Ribosómico 23S/genética , ARN Ribosómico 23S/metabolismo , República de Corea/epidemiología , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/microbiología , Infecciones del Sistema Respiratorio/patología , Índice de Severidad de la Enfermedad
11.
J Phys Chem Lett ; 7(22): 4739-4743, 2016 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-27934200

RESUMEN

Scanning electron microscopy (SEM) is a principal tool for studying nanomaterials, including carbon nanotubes and graphene. Imaging carbon nanomaterials by SEM, however, increases the disorder mode (D-mode) in their Raman spectra. Early studies, which relied on ambiguous ensemble measurements, claimed that the D-mode indicates damage to the specimens by a low-energy electron beam (e-beam). This claim has been accepted by the nanomaterials community for more than a decade without thorough examination. Here we demonstrate that a low-energy e-beam does not damage carbon nanomaterials. By performing measurements on single nanotubes, we independently examined the following factors: (1) the e-beam irradiation itself, (2) the e-beam-deposited hydrocarbon, and (3) the amorphous carbon deposited during synthesis of the material. We concluded that the e-beam-induced D-mode of both carbon nanotubes and graphene originates solely from the irradiated amorphous carbon and not from the e-beam itself or the hydrocarbon. The results of this study should help minimize potential ambiguities for researchers imaging a broad range of nanomaterials by electron microscopy.

12.
Vaccine ; 34(40): 4771-6, 2016 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-27546875

RESUMEN

BACKGROUND: This study was performed to assess the serotype distribution and antibiotic nonsusceptibility of pneumococcal carriage isolates from children in Korea following the introduction of extended-valency pneumococcal conjugate vaccines (PCVs). METHODS: From April to June 2014, nasopharyngeal swabs were collected from children who were attending daycare centers in Korea. The collection was conducted in accordance with the World Health Organization Pneumococcal Carriage Working Group standards. Isolates were identified based on colony morphology, the presence of alpha-hemolysis, and inhibition by optochin test. Serotype was determined by Quellung reaction and sequencing analysis (for serogroup 6). The E-test was performed to determine antibiotic susceptibility. RESULTS: A total of 267 pneumococcal isolates were collected from 734 children. Non-PCV13 serotypes accounted for 88.3% and 23A (12.6%), 15B (10.4%), and 15C (9.5%) were most common. Younger age was associated with higher carriage (65.6% vs. 31.2%, P<0.001), while completion of PCV vaccination was associated with lower carriage caused by PCV13 serotypes (7.4% vs. 20.8%, P=0.007). Overall, nonsusceptibility rates were 86.0% to penicillin and 90.5% to erythromycin, with a multidrug resistance rate of 81.5%. Among penicillin-nonsusceptible isolates, those caused by PCV13 serotypes were 11% and non-PCV13 serotypes were 89%. Frequent non-PCV13 serotypes (23A, 15B, and 15C) were all nonsusceptible to both penicillin and erythromycin except one. CONCLUSION: High rates of carriage caused by non-PCV13 serotypes such as 23A, 15B, and 15C that show nonsusceptibilities to penicillin and erythromycin were noted following the introduction of extended-valency PCVs in Korea.


Asunto(s)
Portador Sano/epidemiología , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/uso terapéutico , Portador Sano/microbiología , Preescolar , Farmacorresistencia Bacteriana Múltiple , Eritromicina , Femenino , Vacuna Neumocócica Conjugada Heptavalente/uso terapéutico , Humanos , Lactante , Masculino , Pruebas de Sensibilidad Microbiana , Nasofaringe/microbiología , Penicilinas , República de Corea/epidemiología , Serogrupo , Streptococcus pneumoniae/efectos de los fármacos
13.
ACS Appl Mater Interfaces ; 7(13): 7294-302, 2015 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-25821907

RESUMEN

There has been impressive progress in the fabrication and characterization of p-type organic electrolyte-gated transistors (EGTs). Unfortunately, despite the importance of n-type organic transistors for complementary circuits, fewer investigations have focused on developing electrolytes as gate dielectrics for n-type organic semiconductors. Here, we present a novel single ion conductor, a polymerized ionic liquid (PIL) triblock copolymer (PS-PIL-PS) composed of styrene (PS) and 1-[(2-acryloyloxy)ethyl]-3-butylimidazolium bis(trifluoromethylsulfonyl)imide (PIL), that conducts only the TFSI anion. This triblock copolymer acts as a gate dielectric to allow low-voltage n-type organic EGT operation. Impedance characterization of PS-PIL-PS reveals that there are three polarization regions: (1) dipolar relaxation, (2) ion migration, and (3) electric double layer (EDL) formation. These polarization regions are controlled by film thickness, and rapid EDL formation can be obtained in thinner polyelectrolyte films. In particular, a 500 nm-thick polyelectrolyte film exhibits a large capacitance of ∼1 µF/cm(2) at 10 kHz. Employing this single ion conducting PIL triblock copolymer as the gate insulator, we achieved low voltage operation (<1 V supply) of poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (P(NDI2OD-T2)) n-type organic EGTs (electron mobility of ∼0.008 cm(2)/(V·s) and ON/OFF current ratio of ∼2 × 10(3)) by preventing electrochemical doping. Furthermore, the recognition that the performance of n-type organic EGTs is diminished by 3D electrochemical doping suggests that it may be necessary to have a unipolar electrolyte to gate n-type organic semiconductors. Finally, we highlight that the use of PIL block copolymer electrolytes as gate insulators opens unique opportunities to explore the role of ion penetration in n-type organic EGTs by tuning the extent of electrochemical doping.

14.
Diagn Microbiol Infect Dis ; 82(1): 26-31, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25700867

RESUMEN

We analyzed 155 clinical group A Streptococcus (GAS) isolates from children at the Seoul National University Children's Hospital between 1991 and 2012 and the Seoul National University Bundang Hospital between 2006 and 2012. The erythromycin resistance rate was 10.3% (16/155), and all isolates during the recent 3 years were susceptible to erythromycin. Among isolates, emm1 (19.4%), emm12 (18.7%), and emm4 (18.1%) were the most prevalent emm types. According to clinical disease, emm1 was most common in invasive GAS infections (47.4%), and emm4, in scarlet fever (48.8%). From 2010 to 2012, an increase in invasive GAS infections and scarlet fever that correlated with an increase in emm1 and emm4 types was observed. The speC detection rate was higher in patients with scarlet fever than in those with other GAS infections (P=0.017). Recently, invasive GAS infections and scarlet fever were associated with an increase in emm1 and emm4, respectively.


Asunto(s)
Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Portadoras/genética , Genotipo , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus pyogenes/clasificación , Streptococcus pyogenes/genética , Adolescente , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Niño , Preescolar , Eritromicina/farmacología , Exotoxinas/genética , Femenino , Hospitales Pediátricos , Hospitales Universitarios , Humanos , Lactante , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana , Estudios Prospectivos , República de Corea/epidemiología , Infecciones Estreptocócicas/patología , Streptococcus pyogenes/efectos de los fármacos , Streptococcus pyogenes/aislamiento & purificación
15.
ACS Appl Mater Interfaces ; 6(21): 19275-81, 2014 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-25320873

RESUMEN

A facile fabrication route to pattern high-capacitance electrolyte thin films in electrolyte-gated transistors (EGTs) was demonstrated using a photoinitiated cross-linkable ABA-triblock copolymer ion gel. The azide groups of poly(styrene-r-vinylbenzylazide) (PS-N3) end-blocks can be chemically cross-linked via UV irradiation (λ = 254 nm) in the self-assembly of poly[(styrene-r-vinylbenzylazide)-b-ethylene oxide-b-(styrene-r-vinylbenzylazide)] (SOS-N3) triblock copolymer in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]). Impedance spectroscopy and small-angle X-ray scattering revealed that ion transport and microstructure of the ion gel are not affected by UV cross-linking. Using a photoinduced cross-linking strategy, photopatterning of ion gels through a patterned mask was achieved. Employing a photopatterned ion gel as the high-capacitance gate insulator in thin film transistors (TFTs), arrays of TFTs exhibited uniform and high device performance. Specifically, both p-type (poly(3-hexylthiophene)) (P3HT) and n-type (ZnO) transistors displayed high carrier mobility (hole mobility of ∼ 1.4 cm(2)/ (V s) and electron mobility of ∼ 0.7 cm(2)/ (V s) and ON/OFF current ratio (∼ 10(5)) at supply voltages below 2 V. This study suggests that photopatterning is a promising candidate to conveniently incorporate high-capacitance ion gels into TFTs in the fabrication of printed electronics.

16.
Korean J Pediatr ; 57(2): 96-9, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24678335

RESUMEN

Hemolytic uremic syndrome (HUS) is one of the most common causes of acute renal failure in childhood and is primarily diagnosed in up to 4.5% of children who undergo chronic renal replacement therapy. Escherichia coli serotype O157:H7 is the predominant bacterial strain identified in patients with HUS; more than 100 types of Shiga toxin-producing enterohemorrhagic E. coli (EHEC) subtypes have also been isolated. The typical HUS manifestations are microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency. In typical HUS cases, more serious EHEC manifestations include severe hemorrhagic colitis, bowel necrosis and perforation, rectal prolapse, peritonitis, and intussusceptions. Colonic perforation, which has an incidence of 1%-2%, can be a fatal complication. In this study, we report a typical Shiga toxin-associated HUS case complicated by small intestinal perforation with refractory peritonitis that was possibly because of ischemic enteritis. Although the degree of renal damage is the main concern in HUS, extrarenal complications should also be considered in severe cases, as presented in our case.

17.
Emerg Infect Dis ; 19(8): 1281-4, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23876792

RESUMEN

In Korea, Mycoplasma pneumoniae was detected in 255/2,089 respiratory specimens collected during 2000-2011; 80 isolates carried 23S rRNA gene mutations, and 69/123 culture-positive samples with the mutation were resistant to 5 macrolides. During 2000-2011, prevalence of the mutation increased substantially. These findings have critical implications for the treatment of children with mycoplasma pneumonia.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Epidemias , Macrólidos/farmacología , Mycoplasma pneumoniae/efectos de los fármacos , Neumonía por Mycoplasma/microbiología , Adolescente , Niño , Preescolar , Análisis Mutacional de ADN , Fluoroquinolonas/farmacología , Humanos , Lactante , Pruebas de Sensibilidad Microbiana , Mutación , Mycoplasma pneumoniae/genética , Neumonía por Mycoplasma/tratamiento farmacológico , Neumonía por Mycoplasma/epidemiología , Prevalencia , ARN Bacteriano/genética , ARN Ribosómico 23S/genética , República de Corea/epidemiología , Tetraciclinas/farmacología
18.
J Korean Med Sci ; 28(1): 36-41, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23341709

RESUMEN

This study was performed to characterize respiratory viral infections in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Study samples included 402 respiratory specimens obtained from 358 clinical episodes that occurred in the 116 children of the 175 consecutive HSCT cohort at Seoul National University Children's Hospital, Korea from 2007 to 2010. Multiplex reverse-transcription polymerase chain reactions were performed for rhinovirus, respiratory syncytial virus (RSV), parainfluenza viruses (PIVs), adenovirus, human coronavirus (hCoV), influenza viruses and human metapneumovirus. Viruses were identified in 89 clinical episodes that occurred in 58 patients. Among the 89 clinical episodes, frequently detected viruses were rhinovirus in 25 (28.1%), RSV in 23 (25.8%), PIV-3 in 16 (18.0%), adenovirus in 12 (13.5%), and hCoV in 10 (11.2%). Lower respiratory tract infections were diagnosed in 34 (38.2%). Neutropenia was present in 24 (27.0%) episodes and lymphopenia was in 31 (34.8%) episodes. Sixty-three percent of the clinical episodes were hospital-acquired. Three patients died of respiratory failure caused by respiratory viral infections. Respiratory viral infections in pediatric patients who have undergone HSCT are common and are frequently acquired during hospitalization. Continuous monitoring is required to determine the role of respiratory viruses in immunocompromised children and the importance of preventive strategies.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Infecciones del Sistema Respiratorio/virología , Adenoviridae/genética , Adenoviridae/aislamiento & purificación , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Coronavirus/genética , Coronavirus/aislamiento & purificación , Femenino , Células Madre Hematopoyéticas/citología , Hospitalización , Humanos , Lactante , Linfopenia/epidemiología , Masculino , Neutropenia/epidemiología , Virus de la Parainfluenza 3 Humana/genética , Virus de la Parainfluenza 3 Humana/aislamiento & purificación , Prevalencia , Virus Sincitiales Respiratorios/genética , Virus Sincitiales Respiratorios/aislamiento & purificación , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/terapia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rhinovirus/genética , Rhinovirus/aislamiento & purificación , Estaciones del Año , Adulto Joven
19.
J Acupunct Meridian Stud ; 4(2): 102-6, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21704952

RESUMEN

The primo-vascular system is described as the anatomical structure corresponding to acupuncture meridians and has been identified in several tissues in the body, but its detailed anatomy and physiology are not well understood. Recently, the presence of keratin 10 (Krt10) in primo-vascular tissue was reported, but this finding has not yet been confirmed. In this study, we compared Krt10 expression in primo-vascular tissues located on the surface of rat abdominal organs with Krt10 expression on blood and lymphatic vessels. Krt10 protein (approximately 56.5 kDa) was evaluated by western blot analysis and immunohistochemistry. Krt10 (IR) in the primo-node was visualized as patchy spots around each cell or as a follicle-like structure containing a group of cells. Krt10 IR was also identified in vascular and lymphatic tissues, but its distribution was diffuse over the extracellular matrix of the vessels. Thus Krt10 protein was expressed in all three tissues tested, but the expression pattern of Krt10 in primo-vascular tissue differed from those of blood and lymphatic vascular tissues, suggesting that structural and the regulatory roles of Krt10 in primo-vascular system are different from those in blood and lymphatic vessels.


Asunto(s)
Abdomen , Vasos Sanguíneos/metabolismo , Queratina-10/metabolismo , Vasos Linfáticos/metabolismo , Meridianos , Mesenterio/metabolismo , Vísceras/metabolismo , Abdomen/irrigación sanguínea , Animales , Western Blotting , Matriz Extracelular , Femenino , Inmunohistoquímica , Masculino , Mesenterio/irrigación sanguínea , Ratas , Ratas Sprague-Dawley , Vísceras/irrigación sanguínea
20.
J Membr Biol ; 239(3): 167-75, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21153632

RESUMEN

The primo-vascular (Bonghan) tissue has been identified in most tissues in the body, but its structure and functions are not yet well understood. We characterized electrophysiological properties of the cells of the primo-nodes (PN) on the surface of abdominal organs using a slice patch clamp technique. The most abundant were small round cells (~10 µm) without processes. These PN cells exhibited low resting membrane potential (-36 mV) and did not fire action potentials. On the basis of the current-voltage (I-V) relationships and kinetics of outward currents, the PN cells can be grouped into four types. Among these, type I cells were the majority (69%); they showed strong outward rectification in I-V relations. The outward current was activated rapidly and sustained without decay. Tetraethylammonium (TEA) dose-dependently blocked both outward and inward current (IC(50), 4.3 mM at ± 60 mV). In current clamp conditions, TEA dose-dependently depolarized the membrane potential (18.5 mV at 30 mM) with increase in input resistance. The tail current following a depolarizing voltage step was reversed at -27 mV, and transient outward current like A-type K(+) current was not expressed at holding potential of -80 mV. Taken together, the results demonstrate for the first time that the small round PN cells are heterogenous, and that, in type I cells, TEA-sensitive current with limited selectivity to K(+) contributed to resting membrane potential of these cells.


Asunto(s)
Potenciales de la Membrana/efectos de los fármacos , Tetraetilamonio/farmacología , Animales , Células Cultivadas , Electrofisiología , Femenino , Masculino , Ratas , Ratas Sprague-Dawley
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA