[Show abstract][Hide abstract] ABSTRACT: Carbohydrate moieties of different glycoproteins, such as cross-reactive carbohydrate determinants (CCDs) and galactose α-1,3-galactose, can induce IgE reactivity with varied clinical significance. In this study, the possible participation of glycan from wheat gliadin, with respect
to its IgE-binding capacity, was investigated in children with food allergies to wheat. Total IgE and wheat-specific IgE quantification, documentation of history, and/or oral food challenge (OFC) were performed for 52 children. Subjects with positive wheat-specific IgE were characterized as
the symptomatic group, never-exposed group, or asymptomatic group. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and glycan detection in gliadin were performed. IgE binding to gliadin and deglycosylated gliadin was measured by immunoblotting and ELISA. Gliadin-specific
IgE was detected and correlated with wheat-specific IgE in the symptomatic, never-exposed, and asymptomatic groups. The glycan range overlapped significantly with the gliadin range. Deglycosylation of gliadin reduced the allergenicity of gliadin. In gliadin, the allergenicity of the glycan
portion was greater in the symptomatic group than in the never-exposed and asymptomatic groups. We conclude that N-glycan in gliadin might exhibit allergenicity as a possible carbohydrate epitope in wheat allergy in children.
[Show abstract][Hide abstract] ABSTRACT: Hand, foot, and mouth disease (HFMD) is an acute, mostly self-limiting infection. Patients usually recover without any sequelae. However, a few cases are life threatening, especially those caused by enterovirus 71 (EV71). A 12-month-old boy was admitted to a primary hospital with high fever and vesicular lesions of the mouth, hands, and feet. After 3 days, he experienced 3 seizure episodes and was referred to our hospital. On admission, he was conscious and his chest radiograph was normal. However, 6 hours later, he suddenly lost consciousness and had developed a massive pulmonary hemorrhage that continued until his death. He experienced several more intermittent seizures, and diffuse infiltration of both lung fields was observed on chest radiography. Intravenous immunoglobulin, dexamethasone, cefotaxime, leukocyte-depleted red blood cells, fresh frozen plasma, inotropics, vitamin K, and endotracheal epinephrine were administered. The patient died 9 hours after intubation, within 3 days from fever onset. EV71 subgenotype C4a was isolated retrospectively from serum and nasopharyngeal swab by real-time reverse transcription-polymerase chain reaction. Here, we report a fatal case of EV71-associated HFMD with sudden-onset massive pulmonary hemorrhage and suspected encephalitis.
Korean Journal of Pediatrics 03/2015; 58(3):112-115. DOI:10.3345/kjp.2015.58.3.112
[Show abstract][Hide abstract] ABSTRACT: Oral food challenge is a definitive diagnostic test for immediate and occasionally delayed adverse reaction to foods. The gold standard for diagnosing food allergy is still the double-blind, placebo-controlled food challenge, but it is time-consuming, expensive and troublesome for physician and patients. Open oral food challenge controlled by trained personnel is useful and sufficient methods when concern of bias is low. We aimed to provide a practical guideline for oral food challenge in children for the diagnosis of suspected food allergy or the evaluation of food tolerance. We considered reasons, types, indications, contraindications, risks, benefits, detailed methods, practical performance, interpretations of test results, and treatments for the adverse reactions of oral food challenge.
[Show abstract][Hide abstract] ABSTRACT: The measurement of exhaled nitric oxide (eNO) is a noticeable tool that reflects asthmatic airway inflammation. However, the eNO values might be variable according to the patient's condition and the method of measurement. The aim of this study was to compare the values of eNO measured by two different eNO analyzers in asthmatic children (Niox mino® [Aerocrine; Solna, Sweden] and CLD88® [Eco Medics; Durten, Switzerland].
[Show abstract][Hide abstract] ABSTRACT: Many patients assume that allergic reactions against foods are responsible for triggering or worsening their allergic symptoms. Therefore, it is important to identify patients who would benefit from an elimination diet, while avoiding unnecessary dietary restrictions. The diagnosis of food allergy depends on the thorough review of the patients's medical history, results of supplemented trials of dietary elimination, and in vivo and in vitro tests for measuring specific IgE levels. However, in some cases the reliability of such procedures is suboptimal. Oral food challenges are procedures employed for making an accurate diagnosis of immediate and occasionally delayed adverse reactions to foods. The timing and type of the challenge, preparation of patients, foods to be tested, and dosing schedule should be determined on the basis of the patient's history, age, and experience. Although double-blind, placebo-controlled food challenges(DBPCFC) are used to establish definitively if a food is the cause of adverse reactions, they are time-consuming, expensive and troublesome for physician and patients. In practice, An open challenge controlled by trained personnel is sufficient especially in infants and young children. The interpretation of the results and follow-up after a challenge are also important. Since theses challenges are relatively safe and informative, controlled oral food challenges could become the measure of choice in children.
Korean Journal of Pediatrics 01/2011; 54(1):6-10. DOI:10.3345/kjp.2011.54.1.6
[Show abstract][Hide abstract] ABSTRACT: Febrile convulsions are classified into simple or complex types, the latter being characterized by increased risk of recurrence and progression to epilepsy. This study aimed to delineate the clinical characteristics of complex febrile convulsions.
Korean Journal of Pediatrics 01/2009; 52(1). DOI:10.3345/kjp.2009.52.1.81
[Show abstract][Hide abstract] ABSTRACT: Performance analysis of the solid oxide fuel cell-microgas turbine (SOFC-MGT) hybrid system has been made. We assume a fuel composition that is methane based with varying concentrations of other species that are expected to be present in biomass-derived gas streams in preparation for the study of biomass fueled SOFC-MGT hybrid system. This is based on the fact that the chemical composition of biomass fuel produced front different fuel production processes is diversified, i.e., in one case one chemical species rich in concentration and in another case another chemical species rich. In the analysis, the multistage model for internal reforming SOFC module developed previously with some modification is used. With this model, studies cover not only the performance of the hybrid system but also the spatial distributions of temperature and concentration of some chemical species inside the module, namely, in the cell stack and in the internal reformer.
Journal of Fuel Cell Science and Technology 11/2008; 5(4). DOI:10.1115/1.2890104 · 0.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A transient three-dimensional, single-phase and non-isothermal numerical model of polymer electrolyte membrane (PEM) fuel cell with high operating temperature has been developed and implemented in computational fluid dynamic (CFD) code. The model accounts for transient convective and diffusive transport, and allows prediction of species concentration. Electrochemical charge double-layer effect is considered. Heat generation according to electrochemical reaction and ohmic loss are involved. Water transportation across membrane is ignored due to low water electro-osmosis drag force of polymer polybenzimidazole (PBI) membrane. The prediction shows transient in current density which overshoots (undershoots) the stabilized state value when cell voltage is abruptly decreased (increased). The result shows that the peak of overshoot (undershoot) is related with cathode air stoichiometric mass flow rate instead of anode hydrogen stoichiometric mass flow rate. Current is moved smoothly and there are no overshoot or undershoot with the influence of charge double-layer effect. The maximum temperature is located in cathode catalyst layer and both fuel cell average temperature and temperature deviation are increased with increasing of current load.
Journal of Power Sources 04/2008; 179(1):220-231. DOI:10.1016/j.jpowsour.2007.12.042 · 6.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Impulse Oscillometry (IOS) was developed as a tool to measure lung function, and as it only requires passive cooperation, it has been successfully used in younger children. The aim of this study was to assess the utility of IOS compared to conventional spirometry for lung function measures in asthmatic Korean children aged 3 to 6 yrs. Total serum IgE levels, total eosinophil counts, and specific IgE levels were measured in 77 children with asthma and 55 control subjects. IOS and spirometry were performed in the children before and after bronchodilator administration. Asthmatic children significantly differed from control subjects in baseline resistance at 10 Hz and in their IOS-assessed bronchodilator responses through a Delta resistance at 5 Hz (mean, -27.4% vs. -13.1%; p = 0.002), 10 Hz (mean, -20.4% vs. -11.5%; p = 0.012), 20 Hz (mean, -16.4% vs. -9.4%; p = 0.016), and 35 Hz (mean, -17.2% vs. -10.2%; p = 0.020). Conventional spirometry did not show statistically significant findings. Asthmatic children significantly differed from control subjects in IOS-assessed bronchodilator response through a Delta resistance at 5 Hz, both in atopic children and in non-atopic children. For atopic children, atopic asthmatic children (n = 58) also significantly differed from atopic controls (n = 30) in baseline resistance at 10 Hz, 20 Hz, 35 Hz and impedance and in IOS-assessed bronchodilator responses through a Delta resistance at 10 Hz and 35 Hz. There were some significant correlations between bronchodilator responses of spirometric parameters and IOS parameters. IOS is useful diagnostic tool in early asthma development and might be a helpful objective outcome measure of early interventions.
[Show abstract][Hide abstract] ABSTRACT: In certain patients, such as young children or individuals with cerebral palsy or severe mental retardation, it is difficult to perform forced expiratory manoeuvres to measure expiratory flow volume. In such cases, we could evaluate obstructive lung disease through the measurement of airway resistance instead of expiratory flow volume.
In this study, we evaluated the correlation of Impulse Oscillometry (IOS) parameters with spirometry values and peak expiratory flow rate (PEFR) measurements to give coherence to IOS recordings in lung function exploration. Total serum IgE levels, total eosinophil counts and specific IgE levels were measured in 48 children with asthma and 66 control subjects, aged 7-15 years of age. IOS, spirometry and PEFR measurements were performed, as well as methacholine challenge. We further analyzed the correlations in atopic asthma, atopic control, nonatopic asthma and nonatopic control groups.
FEV(1) and PEFR showed a significant correlation with impedance and resistance (R) at 5, 10, 20 and 35 Hz, both in atopic asthmatic and in atopic control children. FVC also showed a correlation with impedance and R at 10, 20 and 35 Hz, both in atopic asthmatic and atopic control children. FEF(25-75%) did not show a correlation with resistances.
FEV(1), FVC and PEFR were significantly correlated with IOS parameters, in both asthmatic and control subjects, especially for atopic children. IOS could be used as a suitable measure of lung function when spirometry and PEF cannot be performed.
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION Hardness of delicate water management is one of critical technical challenges to commercialize proton exchange membrane fuel cell. High temperature Polymer Electrolyte Fuel Cells (PEFCs) have been studied because of an increase of CO tolerant, avoiding delicate water flooding, extending membrane durability, faster mass transfer rate and reducing membrane resistance [1-3]. During the fuel cell operation, generated heat should be controlled to retain stable and durable cell performance. For this purpose, a heat exchanger is used and a cooling plate is inserted to every 7th bipolar plate in the stack for passing cooling water from the heat exchanger. Therefore, the cooling water absorbs heat in the stack while passing through flow channels of the cooling plate, and the cooling water that absorbs heat is cooled in the heat exchanger by secondary cooling water, and is circulated back to the stack. In this study, we investigated the possibility of high temperature PEFC stack operation with a water cooling device. The stack performance was measured with different operating conditions. We also studied generated and recovered heat from fuel cell electrochemical reaction at PEFC stack. Heat recovery was evaluated with various operating currents, different water volumes of cooling plate and different secondary coolant temperatures. EXPERIMENTAL Anode and cathode catalysts were prepared using PtRu/C and PtCr/C, respectively. Catalyst inks were made by mixing catalyst with PVdF binder and NMP solvent. The electrode was prepared by casting the catalyst ink onto carbon paper. Sintering process was followed at 150oC for 1.5hr to remove solvent. Polybezimidazole (PBI) membrane [4-6] was impregnated with phosphoric acid for 40min. The amount of impregnated phosphoric acid into the membrane was 380wt%. A PEFC stack was consists of two parts: stack and cooling device. The stack was built by 72 Membrane and Electrode Assemblies (MEAs) with one cooling plate every six MEAs. The cooling device has a loop connecting heat exchanger, reservoir and cooling plates. Stack performance measurements were conducted using hydrogen and air at 120-150oC. Gas utilization was 0.8 for hydrogen and 0.5 for air. Heat recovery was obtained by measuring amount of secondary coolant and inlet/outlet coolant temperature. RESULTS AND DISCUSSION Fig. 1 shows stack performance measuring at 150oC using hydrogen and air. Using water cooling device, recovered heat was calculated by measuring generated and lost heat from stack (Fig. 2). Heat recovery showed higher heat loss at lower stack temperature compared higher stack temperature causing bad insulation of the
[Show abstract][Hide abstract] ABSTRACT: This study sought to evaluate the use of serum eosinophil-derived neurotoxin (EDN), which has been proposed as a marker of airway inflammation in asthma in the diagnosis and evaluation of the severity and bronchial hyperresponsiveness in childhood asthma. We studied 72 children with atopic asthma, 36 children with nonatopic asthma, and 43 healthy controls. Skin prick tests, pulmonary function tests, and methacholine challenge tests were performed, in addition to total eosinophil count, serum ECP, and EDN being measured in all subjects. EDN levels were significantly higher in the atopic asthma group than those in the nonatopic asthma group or control group (p < 0.001), as were ECP levels (p < 0.001). EDN levels differed more significantly among groups divided by asthma severity (p < 0.001) than did ECP levels for these groups (p < 0.05). For the groups divided according to bronchial hyperresponsiveness, both EDN and ECP levels were significantly different (p < 0.005 and p < 0.01, respectively). Significant correlations were found between EDN and PC(20) (gamma = -0.281; p < 0.001), between ECP and PC(20) (gamma = -0.274; p < 0.005), and between EDN and ECP (gamma = 0.443; p < 0.001). In conclusion, serum EDN, as another marker of eosinophilic inflammation together with ECP, may aid in the diagnosis of asthma, especially atopic asthma, and in the evaluation of the severity and bronchial hyperresponsiveness in childhood asthma.
Beiträge zur Klinik der Tuberkulose 04/2007; 185(2):97-103. DOI:10.1007/s00408-006-0054-8 · 2.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Monosensitization differs both immunologically and clinically from polysensitization, and specific immunotherapy is more effective in patients sensitized only to a single pollen than in multiple-pollen sensitized patients. To further examine the differences between monosensitized and polysensitized allergies, allergic indices were examined in 68 monosensitized and 62 polysensitized patients with childhood asthma. Measurements included symptom scores, eosinophil counts, skin prick tests, serum total and specific IgE levels, and IL-10 levels, and were used to compare allergic indices between the two groups. Patients were followed for 18 months following immunotherapy to examine the effectiveness of the treatment. Symptom scores and total IgE levels were significantly higher in the polysensitized group than those in the monosensitized group (p<0.05). The levels of skin test response decreased significantly in both groups following immunotherapy. In the monosensitized group, symptom scores and specific IgE levels were significantly reduced after immunotherapy (p<0.05). In the polysensitized group, symptom scores were reduced after immunotherapy (p<0.05), but the degree of reduction was less than that of the monosensitized group (p<0.05). Moreover, in the polysensitized group, specific IgE levels after immunotherapy did not differ from that before immunotherapy. Serum IL-10 levels were not significantly increased after immunotherapy in either group. In conclusion, polysensitized patients tend to show higher allergic indices and immunotherapy might be less effective for these patients.
Journal of Korean Medical Science 12/2006; 21(6):1012-6. DOI:10.3346/jkms.2006.21.6.1012 · 1.27 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The ultimate purpose of a SOFC/GT hybrid system is for distributed power generation applications. Therefore, this study investigates the possible extension of a SOFC/GT hybrid system to multi-MW power cases. Because of the matured technology of gas turbines and their commercial availability, it was reasonable to construct a hybrid system with an off-the-shelf gas turbine. Based on a commercially available gas turbine, performance analysis was conducted to find the total appropriate power for the hybrid system with consideration of the maximum allowable cell temperature. In order to maintain high performance characteristics of the hybrid system during part-load operations, it was necessary to find the optimal control strategy for the system according to the change in power required. The results of the performance analysis for part-load conditions showed that supplied fuel and air must be changed simultaneously. Furthermore, in order to prevent performance degradation, it was found that both cell temperature and turbine inlet temperature must be maintained as close as possible to design-point conditions.
Journal of Power Sources 07/2006; 158(1):361-367. DOI:10.1016/j.jpowsour.2005.09.031 · 6.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In an effort to improve the bioavailability (BA) of the insoluble compound 20-O-(beta-d-glucopyranosyl)-20(S)-protopanaxadiol (IH901), we prepared beta-cyclodextrin (betaCD) and hydroxypropyl-beta-cyclodextrin (HPbetaCD) inclusion complexes containing IH901. IH901 is a major metabolite formed by intestinal bacteria from protopanaxadiol ginseng saponins. We developed and validated an HPLC-based method to measure IH901 levels from samples prepared in vitro. The phase solubility profiles with both cyclodextrins (CDs) were classified as AL-type, indicating the formation of a 1:1 stoichiometric inclusion complex. Stability constants (Ks) calculated from the phase solubility diagrams showed that the betaCD complex was more stable than the HPbetaCD complex. Consequently, complexes of IH901 and betaCD were prepared by a freeze-drying method and were analyzed by fourier transformation-infrared spectroscopy (FT-IR), X-ray diffraction, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). From these physicochemical characterizations, we confirmed the presence of a new solid phase in the freeze-dried samples. The IH901 released from the complex in a pH 1.2 solution, the pH range of gastric fluids, was considerably lower than the amount released in the other solutions. The IH901 released from the complex in pH 6.8 solution, the range of intestinal fluids, was 9.0-fold greater than pure IH901 powder. However, the amount of IH901 released from the complex in pH 4.0-8.0 was less than 20%. After oral administration of the IH901-betaCD inclusion complex (30 mg/kg IH901) into rats, plasma concentrations were determined by LC/MS/MS. The peak concentration (Cmax) for the inclusion complex was 2.8-fold higher than that for pure IH901 powder. The BA, calculated from the ratio of the AUCoral to the AUCi.v., for the pure IH901 powder, the IH901-betaCD physical mixture, and the inclusion complex was 3.52, 4.34, and 6.57%, respectively. These results indicate that the BA for the inclusion complex was 1.9-fold higher than that for the pure IH901 powder.
International Journal of Pharmaceutics 07/2006; 316(1-2):29-36. DOI:10.1016/j.ijpharm.2006.02.035 · 3.65 Impact Factor