• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.2
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• pp.173-179
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• 2018

Estimating reliability of a non-repairable system using the degradation data, variance assumption such as homogeneity (constant) or heteroscedasticity (time-variant) could affect accuracy of reliability estimation. This paper showed reliability estimation and comparison results under normal conditions using accelerated degradation data obtained from destructive measurements, according to variance assumption of the data at each measurement time. Degradation data from three accelerated conditions with stress factors of temperature and humidity were used to estimate reliability. The $B_{10}$ lifetime was estimated as 1243.8 years by constant variance assumption, and 18.9 years by time-variant variance. And variance assumption provided different analysis results of important stresses to reliability. Thus, accurate assumption of variance at each measurement time is required when estimating reliability using degradation data of a non-repairable system.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.245-249
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• 2009

Purpose: Labral lesions and its anatomic variants have been studied by several authors in the last decade. Buford complex and sublabral recess are most common variants. Their recognition is important in order to distinguish them from superior and anterior labral tear. Materials and Methods: We report one case of a 19-year-old female who was mistaken SLAP lesion for normal variant and was treated with arthroscopic surgery. Results: The arthroscopic finding shows rare normal variant of biceps anchor and superior labrum. The biceps long head tendon was inserted at superior labrum and supraspinatus tendon area. This finding was mistaken to SLAP lesion. Conclusion: We report rare normal variant of biceps anchor and superior labrum that was observed during arthroscopic surgery for SLAP lesion.

• The Korean Journal of Cytopathology
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• v.19 no.2
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• pp.160-163
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• 2008

The cytologic diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) has become one of the common causes of false negative diagnoses when performing fine needle aspiration cytology (FNAC) of the thyroid gland. We retrospectively reviewed all the aspirates for which a diagnosis of FVPTC had been made based on the surgically excised specimens, regardless of the cytologic diagnosis. 145 FNACs was performed in 135 patients. The cytologic diagnoses were categorized as 2 unsatisfactory specimens (1.4%), 16 benign (11.0%), 49 atypical (33.8%) and 78 malignant lesions (53.8%). The tumor cells consistently showed significant nuclear overlapping, irregular nuclei and fine chromatin in all cases; however, nuclear grooves and inclusions were scarce. Galectin-3 immunostaining was performed on the cell blocks of 65 cases and this was positive for 45 cases (69.2%). The results of our study demonstrate that the determination of minimal cytologic criteria is needed to raise the sensitivity of detecting FVPTC by FNAC, and galectin-3 immunostaining is useful to make decisions on the surgical treatment of cytologically atypical thyroid nodules.

• Journal of Yeungnam Medical Science
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• v.31 no.2
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• pp.103-108
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• 2014

Thyroglossal duct cyst (TGDC) carcinoma generally shows a favorable prognosis. If metastasis is present latently, it may not threaten the patient's life immediately. It has been shown, however, that larger than 1 cm papillary carcinoma (PC), level VI metastasis to the lymph node (LN), which is the nearest to the thyroid, independently predicts a worse prognosis. In the case presented herein, a 61-year-old female patient was diagnosed with an about 3 cm PC in the TGDC, particularly the columnar variant subtype, one of the aggressive variants. She had occult papillary thyroid microcarcinoma, but no LN metastasis. Even though she underwent the Sistrunk procedure and total thyroidectomy with central compartment neck dissection followed by high-dose radioactive iodine remnant ablation, however, the cancer cells spread to level IV neck LN, and finally to the lung. Therefore, when a patient is diagnosed with an aggressive histologic variant of PC in the TGDC, even without LN metastasis, the invasive surgical approach and close postoperative surveillance are necessary, with consideration of the risk of disease progression. Therefore, if it is possible to stratify the risk for patients, higher-risk patients can be offered a more invasive therapeutic approach.

• Genes and Genomics
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• v.40 no.11
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• pp.1149-1155
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• 2018

Epileptic encephalopathies are genetically heterogeneous disorders which leads to epilepsy and cause neurological disorders. Seizure threshold 2 (SZT2) gene located on chromosome 1p34.2 encodes protein mainly expressed predominantly in the parietal and frontal cortex and dorsal root ganglia in the brain. Previous studies in mice showed that mutation in this gene can confers low seizure threshold, enhance epileptogenesis and in human may leads to facial dysmorphism, intellectual disability, seizure and macrocephaly. Objective of this study was to find out novel gene or novel mutation related to the gene phenotype. We have identified a large consanguineous Saudi family segregating developmental delay, intellectual disability, epilepsy, high forehead and macrocephaly. Exome sequencing was performed in affected siblings of the family to study the novel mutation. Whole exome sequencing data analysis, confirmed by subsequent Sanger sequencing validation study. Our results showed a novel homozygous mutation (c.9368G>A) in a substitution of a conserved glycine residue into a glutamic acid in the exon 67 of SZT2 gene. The mutation was ruled out in 100 unrelated healthy controls. The missense variant has not yet been reported as pathogenic in literature or variant databases. In conclusion, the here detected homozygous SZT2 variant might be the causative mutation that further explain epilepsy and developmental delay in this Saudi family.

• Dementia and Neurocognitive Disorders
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• v.17 no.4
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• pp.163-173
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• 2018

Background and Purpose: Behavioral variant frontotemporal dementia (bvFTD) is a subtype of frontotemporal dementia, which has clinical symptoms of progressive personality and behavioral changes with deterioration of social cognition and executive functions. The pathology of bvFTD is known to be tauopathy or TDP-43 equally. We analyzed the $^{18}F-THK5351$ positron emission tomography (PET) scans, which were recently developed tau PET, in patients with clinically-diagnosed bvFTD. Methods: Forty-eight participants, including participants with behavioral variant frontotemporal dementia (bvFTD, n=3), Alzheimer's disease (AD, n=21) and normal cognition (NC, n=24) who completed 3T magnetic resonance images, $^{18}F-THK5351$ PET scans, and detailed neuropsychological tests were included in the study. Voxel-wise statistical analysis and region of interest (ROI)-based analyses were performed to evaluate the retention of THK in bvFTD patients. Results: In the voxel-based and ROI-based analyses, patients with bvFTD showed greater THK retention in the prefrontal, medial frontal, orbitofrontal, anterior cingulate, insula, anterior inferior temporal and striatum regions compared to NC participants. Left-right asymmetry was noted in the bvFTD patients. A patient with extrapyramidal symptoms showed much greater THK retention in the brainstem. Conclusions: The distribution of THK retention in the bvFTD patients was mainly in the frontal, insula, anterior temporal, and striatum regions which are known to be the brain regions corresponding to the clinical symptoms of bvFTD. Our study suggests that $^{18}F-THK5351$ PET imaging could be a supportive tool for diagnosis of bvFTD.

• Journal of Genetic Medicine
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• v.18 no.1
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• pp.38-43
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• 2021

Purpose: Demand for genetic counseling on cancer predisposition syndrome is increasing. We evaluated the psychological effect on counselees after genetic counseling at a clinic in a single center. Materials and Methods: We surveyed a total of 72 enrolled participants who visited a genetic counseling clinic at the Samsung Medical Center (SMC). The initial survey was conducted before the first genetic counseling session, and the second survey was conducted after the second genetic counseling session. A total of 43 participants completed both the initial and second surveys. Results: The initial survey of 72 participants indicated higher feelings of guilt in the group with religion, higher depression and anxiety in the group with a diagnosis of self, and higher anxiety in the group on self-referral to the genetic counseling clinic. In the completed survey of 43 participants, overall decreased depression was observed after the second genetic counseling session (P=0.013). Risk perception and anxiety decreased in the group diagnosed with benign variant/variant of uncertain significance (BV/VUS, 25/3) and increased in the group diagnosed with pathogenic variant (PV, 15). Risk perception and anxiety differed between the BV/VUS and PV groups (P<0.001 and P=0.03, respectively). Conclusion: The genetic counseling clinic at the SMC was effective in ameliorating the depression score. Assessment of survey results revealed different depression scores, feelings of guilt and anxiety, and different effects of the genetic counseling clinic, depending on the subgroups. Understanding the needs and psychological characteristics of different groups is necessary for improving genetic counseling services.

• Journal of Korea Trade
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• v.24 no.4
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• pp.1-17
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• 2020

Purpose - Since China has been South Korea's biggest export destination, uncertainty shocks originating from it would influence South Korea's exports. This paper evaluates the effects of China's economic policy uncertainty on Korea's exports to explore the transmission channels. Design/methodology - Incorporating endogeneities and nonlinearities, this study employs a quarterly time-varying parameters vector autoregressive model to investigate the relationships between China's economic policy uncertainty and Korea's exports, where the overparameterization due to time-varying specifications is overcome by a novel stochastic model specification search framework. According to previous theoretical studies, this paper assesses two channels, demand shock channel and exchange rate channel, through which foreign uncertainty affects Korea's exports. This paper identifies the primary drivers of Korea's aggregate exports and analyzes the rationales for the time-variant impacts of China's economic policy uncertainty on Korea's exports to China. Findings - Our empirical results reveal that Korea's aggregate exports are less responsive to China's economic policy uncertainty shocks and significantly move together with global demand. In contrast, its bilateral exports to China are highly responsive in a negative and time-variant way. Moreover, Chinese investment is an important channel through which China's economic policy uncertainty affects Korea's exports to China after 2010. Further, the time-variant effects of China's economic policy uncertainty on Korea's exports to China are related to changes in China's foreign trade policies, global economic conditions, and China's degree of economic freedom. Originality/value - Few previous studies touch the effects of external uncertainty shocks on South Korea's exports. This paper attempts to fill this gap and explicitly investigate the impacts of China's economic policy uncertainty on Korea's exports from a time-varying perspective. As Korea is an export-oriented economy, this study provides insights for the Korean government to understand the transmissions of external uncertainty better.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.76.1-76.13
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• 2020

Background: The predominant infectious bronchitis virus (IBV) strains detected in chickens in Malaysia are the Malaysian variant (MV) and QX-like, which are associated with respiratory distress, nephropathy, and high mortality. On the other hand, the antigenic relatedness and efficacy of IBV vaccines against these 2 field IBV strains are not well characterized. Objectives: This study aimed to determine the antigen relatedness and efficacy of different IB vaccine strains against a challenge with MV and QX-like strains. Methods: The antigen relatedness and the ability of different IB vaccine strains in conferring protection against MV and QX-like were assessed based on the clinical signs, macroscopic lesions, and ciliary activity. Results: The MV strain IBS037A/2014 showed minor antigenic subtype differences with the vaccine virus Mass H120 and 4/91 strains but showed major antigenic subtype differences with the K2 strain. The Malaysian QX-like strain IBS130/2015 showed major antigenic subtype differences with the MV strain IBS037A/2014 and the vaccine strains except for K2. Chickens vaccinated once with Mass (H120) or with non-Mass (4/91 and K2) developed antibody responses with the highest antibody titer detected in the groups vaccinated with H120 and 4/91. The mean ciliary activities of the vaccinated chickens were between 56 to 59% and 48 to 52% in chickens challenged with IBS037A/2014 and IBS130/2015, respectively. The vaccinated and challenged birds showed mild to severe lesions in the lungs and kidneys. Conclusions: Despite the minor antigenic subtype differences, a single inoculation with Mass or non-Mass vaccines could not protect against the MV IBS037A/2014 and QX-like IBS130/2015.

• Journal of Genetic Medicine
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• v.19 no.2
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• pp.94-99
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• 2022

Lesch-Nyhan disease (LND) is a rare X-linked recessive inherited purine metabolic disorder that accompanies neurodevelopmental problems. Neurofibromatosis type 1 (NF1) is a relatively common autosomal dominant inherited genetic disorder characterized by tumors in various systems. Some children with NF1 also accompanies neurodevelopmental problems. Here, we describe a 5-year-old boy with a maternally inherited pathogenic variant in NF1 and hypoxanthine-guanine phosphoribosyltransferase (HPRT). He was referred for severe neurodevelopmental impairment and hyperuricemia. His mother was diagnosed with NF1 and the patient was also suspected of having NF1 because of cafe au lait macules. He had dystonia, rigidity, cognitive deficit, and speech/language impairment. Serum and urine uric acid concentrations were elevated. He had more severe neurodevelopmental delay than patients with only NF1, so his clinical symptoms could not be fully understood by the disease alone. To find the cause of his neurologic symptoms and hyperuricemia, the patient and his mother underwent a whole-exome sequencing test. As a result, the pathogenic variant c.151C>T (p.Arg51Ter) in HPRT1 was identified as hemizygote in the patient and heterozygote in his mother. The pathogenic variant c.7682C>G (p.Ser2561Ter) in NF-1 was identified as heterozygotes in both of them. Although the clinical symptoms of both diseases were overlapping and complicated, genetic testing was helpful for accurate diagnosis and treatment. Therefore, we suggest to consider preemptive genetic evaluation if there are symptoms not sufficiently explained by known existing diseases. And it is considered valuable to review this rare case to understand the clinical course and possible synergic effects of these diseases.