• Journal of Yeungnam Medical Science
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• v.34 no.2
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• pp.182-190
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• 2017

Background: Respiratory viruses play a significant role in the etiology of acute respiratory infections and exacerbation of chronic respiratory illnesses. This study was conducted to identify the epidemiological and clinical characteristics of children with acute viral lower respiratory infections. Methods: This study investigated 1,168 children diagnosed with acute viral lower respiratory tract infections (RTIs) between January 2012 and December 2014. Specimens of respiratory viruses were collected using a nasopharyngeal swab and analyzed by reverse transcriptase polymerase chain reaction. We retrospectively reviewed the medical records and analyzed the clinical features of children hospitalized for acute lower respiratory infections. Results: Respiratory syncytial virus (RSV), the main cause of infection in children aged <5 years, was the most commonly detected pathogen in children with bronchiolitis and pneumonia, and resulted in high proportions of children requiring oxygen treatment and intensive care unit admission. Rhinovirus was preceded by RSV as the second most common cause of bronchiolitis and pneumonia, and was detected most frequently in the children aged ${\geq}6$ years. In addition, asthma was predominantly caused by rhinovirus in children aged ${\geq}6$ years, whereas croup was mostly caused by parainfluenza virus in those aged <5 years. Rhinovirus infection (p<0.001) and history of asthma (p=0.049) were identified as significant risk factors for readmission within a month. Conclusion: We identified the epidemiological and clinical characteristics of respiratory viruses in children with acute lower respiratory infections during the last 3 years. Our findings may provide useful clinical insight to comprehend the acute viral lower RTIs in children.

• Journal of Microbiology
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• v.43 no.4
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• pp.375-380
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• 2005

Autonomous ultradian metabolic oscillation (T$\simeq$50 min) was detected in an aerobic chemostat culture of Saccharomyces cerevisiae. A pulse injection of GSH (a reduced form of glutathione) into the culture induced a perturbation in metabolic oscillation, with respiratory inhibition caused by $H_2S$ burst pro-duction. As the production of $H_2S$ in the culture was controlled by different amino acids, we attempted to characterize the effects of GSH on amino acid metabolism, particularly with regard to branched chain and sulfur-containing amino acids. During stable metabolic oscillation, concentrations of intra-cellular glutamate, aspartate, threonine, valine, leucine, isoleucine, and cysteine were observed to oscil-late with the same periods of dissolved $O_2$ oscillation, although the oscillation amplitudes and maximal phases were shown to differ. The methionine concentration was stably maintained at 0.05 mM. When GSH (100 $\mu$M) was injected into the culture, cellular levels of branched chain amino acids increased dramatically with continuous $H_2S$production, whereas the cysteine and methionine concentrations were noticeably reduced. These results indicate that GSH-dependent perturbation occurs as the result of the promotion of branched chain amino acid synthesis and an attenuation of cysteine and methionine synthesis, both of which activate the generation of $H_2S$. In a low sulfate medium containing 2.5 mM sulfate, the GSH injections did not result in perturbations of dissolved $O_2$ NAD(P)H redox oscillations without burst $H_2S$ production. This suggests that GSH-dependent perturbation is intimately linked with the metabolism of branched-chain amino acids and $H_2S$ generation, rather than with direct GSH-GSSG redox control.

• Journal of Yeungnam Medical Science
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• v.30 no.2
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• pp.95-100
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• 2013

Background: This study was performed to investigate the epidemiologic and clinical features of acute respiratory viral infection in hospitalized children. Methods: From 2010 to 2012, we tested nasopharyngeal swab specimen in 1,584 hospitalized children with multiple real-time polymerase chain reactions to identify 10 kinds of respiratory viruses (including influenza virus A, B (FluA, FluB), respiratory syncytial virus (RSV), human metapneumovirus (MPV), adenovirus (AdV), human coronavirus (CoronaV), human enterovirus (HEV), human bocavirus (HBoV), parainfluenza virus (PIV), and human rhinovirus (Rhinovirus)). We analyzed the positive rate, annual and seasonal variations, and clinical features (respiratory tract and non-respiratory tract) according to the retrospective review of medical records. Results: Respiratory viruses were detected from 678 (42.8%) of 1,584 patients. The most common detected virus was RSV (35.0%), and then AdV (19.0%), HEV (18.1%). The critical period of the respiratory viral infection was during the first 12 months of a child's life. PIV increased by 8.4%, 12.1%, and 21.1% annually. Bronchiolitis was most frequently caused by RSV, and croup was frequently caused by PIV. The most common cause of meningitis was HEV. Hepatitis-associated respiratory virus was developed 111 in 678 cases. Conclusion: Although this study was confined to a single medical center for three years, we identified the epidemiology and clinical feature of respiratory viruses in Daegu from 2010 to 2012. Future surveillance will be necessary for annual and seasonal variations.

• Biomedical Science Letters
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• v.27 no.4
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• pp.283-290
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• 2021

Severe acute respiratory syndrome coronavirus (SARS-CoV2) is a major coronavirus that infects humans with human Coronavirus (HuCoV)-229E, HCoV-OC43, HCoV-HKU1, HCoV-NL63, Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle east respiratory syndrome coronavirus (MERS-CoV). SARS-CoV2 is currently a global pandemic pathogen. In this study, we developed conventional RT-PCR based diagnostic system for the detection of SARS-CoV2 which is relatively inexpensive but has high stability and a wide range of users. Three conventional RT-PCR primer sets capable of forming specific band sizes by targeting the ORF1ab [232 nucleotide (nt)], E (200 nt) and N (288 nt) genes of SARS-CoV2 were developed, respectively, and it were confirmed to be about 10~100 times higher detection sensitivity than the previously reported methods. In addition, a standard positive control that can generate specific amplicons by reacting with the developed RT-PCR primers and verify the false-positiv from contamination of the laboratory was produced. Therefore, the diagnostic system that uses the RT-PCR method is expected to be used to detect SARS-CoV2.

• Annals of Geriatric Medicine and Research
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• v.22 no.4
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• pp.200-203
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• 2018

Strongyloides stercoralis is an intestinal nematode that occurs sporadically in temperate areas like Korea. People who are in the immunosuppressed state, over the age of 65 or under the corticosteroid therapy are at risk for developing Strongyloides hyperinfection syndrome. Acute respiratory distress syndrome (ARDS) with alveolar hemorrhage is a rare presentation of Strongyloides hyperinfection. A 78-year-old man had been irregularly injected corticosteroid on his knees, but did not have any immunosuppressive disease. He was initially diagnosed with ARDS and septic shock. Bronchoalveolar lavage (BAL) fluid was bloody and its cytology revealed helminthic larvae identified as S. stercoralis. Results of Cytomegalovirus polymerase chain reaction (PCR), Pneumocystis jirovecii PCR, and Aspergillus antigen testing of the BAL fluid were positive. The clinical progress quickly deteriorated with multiple organ failure, shock and arrhythmia, so he finally died. This is a rare case of ARDS in an older patient without any known immunosuppressive conditions, with alveolar hemorrhage and S. stercoralis being found via BAL.

• Molecules and Cells
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• v.40 no.4
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• pp.307-313
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• 2017

Caloric restriction (CR) has been shown to extend lifespan and prevent cellular senescence in various species ranging from yeast to humans. Many effects of CR may contribute to extend lifespan. Specifically, CR prevents oxidative damage from reactive oxygen species (ROS) by enhancing mitochondrial function. In this study, we characterized 33 single electron transport chain (ETC) gene-deletion strains to identify CR-induced chronological lifespan (CLS) extension mechanisms. Interestingly, defects in 17 of these 33 ETC gene-deleted strains showed loss of both respiratory function and CR-induced CLS extension. On the contrary, the other 16 respiration-capable mutants showed increased CLS upon CR along with increased mitochondrial membrane potential (MMP) and intracellular adenosine triphosphate (ATP) levels, with decreased mitochondrial superoxide generation. We measured the same parameters in the 17 non-respiratory mutants upon CR. CR simultaneously increased MMP and mitochondrial superoxide generation without altering intracellular ATP levels. In conclusion, respiration is essential for CLS extension by CR and is important for balancing MMP, ROS, and ATP levels.

• Clinical and Experimental Pediatrics
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• v.53 no.5
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• pp.644-647
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• 2010

Purpose: To evaluate myocardial conductivity to understand cardiac involvement in patients with mitochondrial disease. Methods: We performed retrospective study on fifty-seven nonspecific mitochondrial encephalopathy patients with no clinical cardiac manifestations. The patients were diagnosed with mitochondrial respiratory chain complex defects through biochemical enzyme assays of muscle tissue. We performed standard 12-lead electrocardiography (ECG) on all patients. Results: ECG abnormalities were observed in 30 patients (52.6%). Prolongation of the QTc interval (>440 ms) was seen in 19 patients (33.3%), widening of the corrected QRS interval in 15 (26.3%), and bundle branch block in four (7.0%). Atrioventricular block, premature atrial contraction and premature ventricular contraction were seen in two patients each (3.5%) and Wolff-Parkinson-White syndrome in one patient (1.8%). Conclusion: Given this finding, we recommend active screening with ECG in patients with mitochondrial disease even in patients without obvious cardiac manifestation.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.363-370
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• 2006

Porcine reproductive and respiratory syndrome (PRRS) is an economically important disease of swine that occurs all over the swine industry worldwide. It was first observed in the Unite States in 1987 then in Europe in 1990. It has been described in Japan and in Korea in 1993. PRRS virus is divided into two distinct types, North American and European, genetically. Based on our limited knowledge there has been no report on the existence of European PRRSV. But according to the government's Korea Customs Service there has been many importations of breeding pigs from Europe. These seem to make an estimate that European PRRSV could be introduced in Korea by inflow of European breeding pigs. We first detected the European PRRSV could be introduced in Korean pig farms by using polymerase chain reaction (PCR). Further, it is also identified that there are not only North American PRRSV antibody but also a European PRRSV antibody. According to the genetical and serological experiment results, the presence of established North American PRRSV in Korea is due to the use of live vaccines made of North American PRRSV strain as well field virus infection, and the European PRRSV is possibly introduced from imported breeding stock.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.43-48
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• 1991

New quinoline compounds were designed, synthesized, and examined with submitochondria. Most compounds showed high activity against NADH-ubiquinone oxidoreductase. Inhibition activity was mainly affected by the length of the lipophilic part, regardless of bulkiness or location of a phenyl group in the side chain. The $\beta-methyl$ group was demons)rated to be the optimal functionality on the nuclei of the quinoline derivatives so 4hat either deletion or insertion of a methylene on the group eliminated its activity.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.561-569
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• 2004

To detect viral agents and isolate porcine circovirus 2 (PCV2), 60 samples of lung and lymph node were collected from 5 to 12 week-old pigs that had showed clinical signs of postweaning multisystemic wasting syndrome (PMWS). Polymerase chain reactions (PCRs) were conducted to identify the viral pathogens including PCV1, PCV2, porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) that have been considered to be the causal agents of PMWS. Among 60 samples, PCV 2 was detected from 57 samples but no PCV 1 was detected. PRRSV and/or PPV were also detected from 27 (47.4%) samples and 1 (1.8%) sample of these 57 PCV 2-positive samples, respectively. Tissue homogenates were inoculated onto PCV-free PK-15 cell monolayers. Seven isolates were confirmed as PCV 2 by multiplex PCR, indirect immunofluorescence assay, and transmissible electron microscopy. These date suggest that PRRSV is a major cofactors causing PMWS in pigs that were infected with PCV2 in Korea.