• Tuberculosis and Respiratory Diseases
• /
• v.72 no.3
• /
• pp.275-283
• /
• 2012

Background: Healthy individuals who develop nontuberculous mycobacteria (NTM) lung disease are likely to have specific susceptibility factors which can lead to a NTM infection. The aim of the present study was to investigate the mechanism underlying innate immune responses, including the role of mitogen-activated protein kinase (MAPK), in Mycobacterium abscessus lung disease. Methods: Extracellular signal-regulated kinase (ERK1/2) and p38 MAPK expression in monocytes from peripheral blood mononuclear cells were measured by Western blot analysis after stimulation by Mycobacterium avium in five patients with M. abscessus lung disease and seven healthy controls. A M. avium-induced cytokine assay was performed after inhibition of ERK1/2 and p38 MAPK pathways. Results: Mycobacterium avium induced p38 and ERK1/2 expression in monocytes from healthy controls and subsequently upregulated tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6, and IL-10 production. In monocytes from patients with M. abscessus lung disease, however, induction of p38 and ERK1/2 expression, and the production of TNF-${\alpha}$, IL-6, and IL-10 were significantly lower. Conclusion: Decreased activity of MAPK and cytokine secretion in monocytes from patients with M. abscessus lung disease may provide an explanation regarding host susceptibility to these uncommon infections.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.6
• /
• pp.735-746
• /
• 1999

Background: As the prevalence of nontuberculous mycobacteriosis has been increasing rapidly, there has been recent advance in diagnostic methods and drug therapies for disease. Although the incidence of pulmonary disease caused by nontuberculous mycobacteria(NTM) has been increasing in Korea since 1990, detailed clinical description about the disease were very few. In this study we described the clinical manifestations, radiologic findings, and therapeutic outcomes of nontuberculous mycobacterial pulmonary disease. Methods: Medical records and radiologic findings were retrospectively reviewed in 27 patients who were fulfilled the diagnostic criteria of ATS guideline for NTM pulmonary disease between January of 1990 and August of 1998 in Seoul National University Hospital(SNUH). Results: Of the 27 patients, 15 were male. The mean age was 51.5 yr($\pm$11.9). Twenty patients(74.1%) had preexisting pulmonary diseases. Among them, 19 patients had previous pulmonary tuberculosis. Sixteen patients(59.2%) had cavitary lesions and the majority showed slow progression over 1 yr during follow up period on radiography. Susceptibility test to standard antituberculous drugs showed 100% resistance to INH, 72.2% to RMP, 81.5% to EMB, 92.6% to PZA. The average resistance rate to 2nd-line antituberculous drugs was 66.1%. Among twenty-one patients(77.8%) who received drug therapy over 6 months, 11 subjects were improved and 10 subjects were aggravated. Of six subjects(22.2%) without therapy, 5 patients were aggravated. Presence of cavity and less than 3 sensitive drugs in the regimen were indicators for adverse outcome. Conclusion : The nontuberculous mycobacterial pulmonary diseases in our hospital developed predominantly in older patients with preexistent pulmonary disease. The results of antituberculous drug therapy has been frustrating and disappointing. To improve treatment response, different susceptibility tests and drug regimens for different species of NTM should be performed. Also, diagnostic and therapeutic guidelines of Korea should be made in the recent future.

• Tuberculosis and Respiratory Diseases
• /
• v.72 no.1
• /
• pp.82-87
• /
• 2012

In 2005, a group of mycolic acid-containing bacteria was characterized as belonging to a novel genus, Segniliparus with species Segniliparus rugosus and S. rotundus. We report a case of the S. rugosus isolated from a 54-year-old woman with radiologic features mimicking that of non-tuberculous mycobacteriosis (NTM). When the patient first visited our hospital, an acid-fast bacteria (AFB) smear tested positive and Mycobacterium tuberculosis polymerase chain reaction (TB PCR) was negative in the bronchoalveolar lavage sample. After 2 months, the growing colonies were reported as NTM, but could not be identified because they had died. One year after the initial visit, induced sputum samples showed the same results, positive AFB smear and negative TB PCR. At this point, the growing colonies were identified as S. rugosus. Therefore, we should consider Segniliparus genus as a differential diagnosis for AFB in respiratory specimens in addition to the genus Mycobacterium.

• Korean Journal of Radiology
• /
• v.23 no.1
• /
• pp.101-111
• /
• 2022

Objective: Familial intracranial aneurysms (FIAs) are found in approximately 6%-20% of patients with intracranial aneurysms (IAs), suggesting that genetic predisposition likely plays a role in its pathogenesis. The aim of this study was to identify possible IA-associated variants using whole exome sequencing (WES) in selected Korean families with FIA. Materials and Methods: Among the 26 families in our institutional database with two or more IA-affected first-degree relatives, three families that were genetically enriched (multiple, early onset, or common site involvement within the families) for IA were selected for WES. Filtering strategies, including a family-based approach and knowledge-based prioritization, were applied to derive possible IA-associated variants from the families. A chromosomal microarray was performed to detect relatively large chromosomal abnormalities. Results: Thirteen individuals from the three families were sequenced, of whom seven had IAs. We noted three rare, potentially deleterious variants (PLOD3 c.1315G>A, NTM c.968C>T, and CHST14 c.58C>T), which are the most promising candidates among the 11 potential IA-associated variants considering gene-phenotype relationships, gene function, co-segregation, and variant pathogenicity. Microarray analysis did not reveal any significant copy number variants in the families. Conclusion: Using WES, we found that rare, potentially deleterious variants in PLOD3, NTM, and CHST14 genes are likely responsible for the subsets of FIAs in a cohort of Korean families.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.8
• /
• pp.309-315
• /
• 1986

We proposed a preliminary Data Flow Machine Model(DNL1) operating on the basis of Node Label. In this model, all the PMs(Processing Modules) were synchronized with the content of LC(Level Counter) and were not implemented dy the processing cability on conditional nodes. This paper presents an architecture of a concurrent multiprocessor system which was developed from DNL1 with two additional types of memories, CF(Control Flag) and ETF (Enabled Token Flag). The CF memory holds the control condition flag ('1' or '0') to be referenced to when a node is fired and the ETF represents the firability of a certain node. Firable nodes are fetched to the PU(Processing Unit) and processed. This Data Flow system can be extended hierarchically by a network of simple modules. The principle working elements of the machine are a set of PMs, each of which performs the execution of the data flow procedures held in a local memory, NTM(Node Token Memory) within the PM.

• Tuberculosis and Respiratory Diseases
• /
• v.75 no.6
• /
• pp.238-243
• /
• 2013

Background: The aim of our study was to evaluate the "diagnosis changed" rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: "diagnosis maintained", "diagnosis changed" (initially notified as TB, but ultimately diagnosed as non-TB), and "administrative error" (notified as TB due to administrative errors). Results: Excluding 17 patients in the "administrative error" group, the "diagnosis maintained" and "diagnosis changed" groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of "diagnosis changed" were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn's disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a "diagnosis changed" result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high "diagnosis changed" rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the "diagnosis changed" rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of "diagnosis changed" cases is desirable.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.2
• /
• pp.171-176
• /
• 2019

A comparative study between commercially available mycobacteria growth indicator tubes (MGIT) in the BACTEC MGIT 960 System and the conventional Ogawa media was carried out to assess the effectiveness of the re-decontaminating process for the recovery of mycobacteria. Processed specimens with 5% sodium hydroxide and 0.5% N-acetyl-L-cysteine were inoculated into MGIT and Ogawa media. The acid fast bacilli (AFB) recovered from the cultures were identified using a mycobacterium tuberculosis (TB) antigen kit. If contaminants were observed in the MGIT tubes within five days, a decontaminating process was repeated. A total of 1,190 out of 4,790 (24.8%) specimens showed positive results using the BACTEC MGIT 960 system. Among them, 278 specimens were reprocessed. When the MGIT and Ogawa results were compared, it showed discordant results (weighted kappa value: 0.283). One TB and 10 nontuberculous mycobacteria (NTM) were newly detected in MGIT only. The likely benefit of the re-decontaminating process is the detection of additional mycobacteria that could not be detected without a re-decontaminating process despite being small in number. In addition to the combination of MGIT and Ogawa, the re-decontaminating process is recommended in the case of contaminations to recover mycobacteria.

• Wind and Structures
• /
• v.38 no.1
• /
• pp.1-13
• /
• 2024

In order to effectively simulate nonstationary stochastic turbulent wind fields, four separation hybrid (SEP-H) models are proposed in the present study. Based on the assumption that the lateral turbulence component at one single-point is uncorrelated with the longitudinal and vertical turbulence components, the fluctuating wind is separated into 2nV-1D and nV1D nonstationary stochastic vector processes. The first process can be expressed as double proper orthogonal decomposition (DPOD) or proper orthogonal decomposition and spectral representation method (POD-SRM), and the second process can be expressed as POD or SRM. On this basis, four SEP-H models of nonstationary stochastic turbulent wind fields are developed. In addition, the orthogonal random variables in the SEP-H models are presented as random orthogonal functions of elementary random variables. Meanwhile, the number theoretical method (NTM) is conveniently adopted to select representative points set of the elementary random variables. The POD-FFT (Fast Fourier transform) technique is introduced in frequency to give full play to the computational efficiency of the SEP-H models. Finally, taking a long-span bridge as the engineering background, the SEP-H models are compared with the dimension-reduction DPOD (DR-DPOD) model to verify the effectiveness and superiority of the proposed models.

• East Asian Economic Review
• /
• v.25 no.1
• /
• pp.33-71
• /
• 2021

Many different approaches and databases have been developed for the evaluation of non-tariff measures (NTMs) and free trade agreements (FTAs). This paper is devoted to the EU-South Korea agreement, which is the first 'second-generation' FTA of the EU, addressing a wide array of non-tariff policies. We review the evolution of NTM types applicable to the EU-South Korea trade relationship and the role of NTMs in ex-ante and ex-post analyses of the agreement. Subsequently a structural gravity model is employed to assess the value added of information on different aspects of FTAs and types of NTMs by evaluating their ability to predict the trade effects of the EU-South Korea FTA. Our results show that, when accounting for information on the components common in modern deep trade agreements, no additional trade effect is attributable to the EU-South Korea FTA. The evolution of NTMs differs considerably across indicators used, but trade predictions are hardly affected. Most specifications point towards a negative effect of bilateral differences in the number of technical barriers to trade (TBT) applied and sanitary and phytosanitary measures (SPS) against which trading partners issued complaints at the WTO.

• Korea Trade Review
• /
• v.45 no.1
• /
• pp.101-118
• /
• 2020

This study aims to quantify the effects of non-tariff measures (NTMs) on exports in the Korean manufacturing industry. To do this, we employ product-level export data that includes information about whether or not a product is affected by NTMs. One of the main results is that NTMs (SPS/TBT) on average led to reduction in Korean exports. However, the effects of NTMs differed depending on the income level of the NTM-imposing country. The NTMs imposed by high-income countries, such as U.S.A. and Japan, were found to impede Korean exports, whereas the export effect of NTMs imposed by low-income countries such as China was found to not be statistically significant. In addition, the results analyzed based across industries, income level, and types of NTMs are as follows. First, NTMs imposed on textile-related products generally hindered exports regardless of the type of NTMs, but its negative impact on exports was noticeable in the case of NTMs originating from high-income countries. On the other hand, chemical product-related NTMs were found to lead to an increase in Korean exports, and it had a positive effect in the case of SPS imposed by low-income countries. In other industries except for textile- and chemical-related products, the effects of NTMs on exports were either statistically insignificant or showed inconsistent patterns.