EEG and EMG recording system for sleep study with a freely moving rat

Youjin Lee,Yena Lee,Seoyoung Hwang,Hee Soo Jeong,Yunjin Kim,Yunbin Lee,Jihoo Lee,Seoyeon Park,Sang Beom Jun 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7

Sleep is known to play an important role in cognitive functions as well as in physical recovery. Especially, high-quality sleep is closely associated with smooth sleep cycles between NREM (non-rapid eye movement) and REM (rapid eye movement) sleep. It is well known that both sleep stages show clear distinction in electroencephalogram (EEG) and electromyogram (EMG) signals. Therefore, as a first step for sleep study with rodents, a sleep monitoring system must be established for stable measurement of EEG and EMG. There are two challenges for the setup. First, animals should be able to freely move without interruption of EEG or EMG recording cable, so that their natural behavior and sleep can occur. Second, long-term EEG and EMG should be recorded stably. Also, the movements of animals can cause a cable tension and moving artifacts. The movement-related artifacts can interfere with judgment of sleep stages. Also, rodent gnawing of the recording cable frequently leads to early termination of sleep study. In this study, in order to overcome these problems, acrylic cages were developed for sleep monitoring which can minimize the interruption of cables and the artifacts. Principle of lever mechanics is applied to rotational cover of the cage, and it rotates vertically in synchronization with rat’s movement. When the rat stand up, the cage cover opens up to prevent the cable from loosening. Therefore, cable tension can be stably maintained, allowing the rat to move freely without causing artifact. As a result, long-term EEG and EMG recordings are successful performed, and specific characteristics of each sleep stages can be extracted due to the high-quality recorded signals. We expected that the developed sleep monitoring setup can be applied to various long-term in vivo experiments with rats.

Risk of Osteoporotic Fractures after Thyroid-stimulating Hormone Suppression Therapy in Patients with Thyroid Cancer

Lee, Youjin,Yoon, Byung-Ho,Lee, Seeyoun,Chung, Youn Kyung,Lee, Young-Kyun The Korean Society for Bone and Mineral Research 2019 대한골대사학회지 Vol.26 No.1

<P><B>Background</B></P><P>The effects of subclinical hyperthyroidism on fracture risk induced by thyroid-stimulating hormone (TSH) suppression therapy in patients with thyroid cancer still remains controversial. We performed a meta-analysis and systematic review to evaluate the effects of TSH suppression therapy on osteoporotic fracture in patients with thyroid cancer.</P><P><B>Methods</B></P><P>We performed a systematic search to identify studies which included osteoporotic fractures (hip fracture and vertebral fracture) in patients on TSH suppression therapy for thyroid cancer. Main outcome measures were occurrence and risk of osteoporotic fractures including hip and vertebral fractures between patients and controls.</P><P><B>Results</B></P><P>A systematic search yielded a total of 8 studies appropriate for review which included osteoporotic fracture outcome in patients on TSH suppression therapy for thyroid cancer. Studies with larger number of subjects showed the higher risk of osteoporotic fracture in group with TSH suppression therapy, although studies with smaller sample size presented a similar risk of fracture with control group.</P><P><B>Conclusions</B></P><P>Although studies were limited by small numbers, results suggested possible association between chronic TSH suppression therapy and the increased risk of osteoporotic fractures in patients with thyroid cancer.</P>

Optimal blood pressure target in the elderly: rationale and design of the HOW to Optimize eLDerly systolic Blood Pressure (HOWOLD-BP) trial

Dong-Hwa Lee,Ju-Hee Lee,So Young Kim,Hae-Young Lee,Jung-Yeon Choi,Youjin Hong,Sue K. Park,Dong Ryeol Ryu,Dong Heon Yang,Seok-Jae Hwang,Jung Hyun Choi,Kye Hun Kim,Sun Hwa Lee,Seung Jae Joo,Jae-Hyeong P 대한내과학회 2022 The Korean Journal of Internal Medicine Vol.37 No.5

Background/Aims: The optimal systolic blood pressure (SBP) goal for elderly patients with hypertension, especially to reduce cardiovascular disease (CVD) incidence and improve outcome, is unclear. This study aimed to evaluate the beneficial effects of intensive treatment for hypertension on the incidence of CVD in elderly Korean patients. Methods: The HOW to Optimize eLDerly systolic Blood Pressure (HOWOLD-BP) trial is a multicenter, parallel-design, open-label, randomized controlled trial designed to evaluate whether intensive treatment (SBP ≤ 130 mmHg) will provide more benefits in lowering the incidence and mortality associated with CVD than standard treatment (SBP ≤ 140 mmHg) in elderly patients with hypertension aged ≥ 65 years. For this study, eleven university hospitals in Korea will enroll approximately 3,176 elderly patients with hypertension between 2019 and 2022. Patients will be requested to visit the clinic every 4 months for the first year and every 6 months thereafter for 36 months. Parameters, including clinic and home blood pressure, anthropometric and laboratory findings, and frailty assessments, will be collected according to the standardized protocol. The primary outcome is a composite of CVD (acute coronary syndrome, stroke, and heart failure) incidence and cardiovascular deaths. Results: As of December 2021, 1,655 participants had been enrolled in the study, including 831 patients in the standard group and 824 patients in the intensive group. Conclusions: The HOWOLD-BP trial is the first study performed in Korea to evaluate the beneficial effects of intensive blood pressure treatment on CVD in elderly patients with hypertension. The results of this study will help clarify the appropriate target SBP for this population.

A Nationwide Survey on Gastrointestinal Endoscopy Practice Patterns among Pediatric Endoscopists in South Korea

Yoo Min Lee,Yoon Lee,So Yoon Choi,Hyun Jin Kim,Suk Jin Hong,Yunkoo Kang,Eun Hye Lee,Kyung Jae Lee,Youjin Choi,Dae Yong Yi,Seung Kim,Ben Kang 대한소아소화기영양학회 2023 Pediatric gastroenterology, hepatology & nutrition Vol.26 No.2

Purpose: Gastrointestinal (GI) endoscopy is an important tool for diagnosing and treating GI diseases in children. This study aimed to analyze the current GI endoscopy practice patterns among South Korean pediatric endoscopists. Methods: Twelve members of the Korean Society of Pediatric Gastroenterology, Hepatology and Nutrition developed a questionnaire. The questionnaire was emailed to pediatric gastroenterologists attending general and tertiary hospitals in South Korea. Results: The response rate was 86.7% (52/60), and 49 of the respondents (94.2%) were currently performing endoscopy. All respondents were performing esophagogastroduodenoscopy, and 43 (87.8%) were performing colonoscopy. Relatively rare procedures for children, such as double-balloon enteroscopy (DBE) (4.1%), endoscopic retrograde cholangiopancreatography (ERCP) (2.0%), and endoscopic ultrasound (EUS) (2.0%), were only performed by pediatric gastroenterologists at very few centers, but were performed by adult endoscopists in most of the centers; of all the respondents, 83.7% (41/49) performed emergency endoscopy. In most centers, the majority of the endoscopies were performed under sedation, with midazolam (100.0%) and ketamine (67.3%) as the most frequently used sedatives. Conclusion: While most pediatric GI endoscopists perform common GI endoscopic procedures, rare procedures, such as DBE, ERCP, and EUS, are only performed by pediatric gastroenterologists at very few centers, and by adult GI endoscopists at most of the centers. For such rare procedures, close communication and cooperation with adult GI endoscopists are required.

Korean Children and Adolescents with Crohn's Disease Are More Likely to Present with Perianal Fistulizing Disease at Diagnosis Compared to Their European Counterparts

Kang, Ben,Kim, Jung Eun,Jung, Jae Hun,Choe, Jae Young,Kim, Mi Jin,Choe, Yon Ho,Kim, Seung,Koh, Hong,Lee, Yoo Min,Lee, Jee Hyun,Lee, Yoon,Lee, Ji-Hyuk,Lee, Hae Jeong,Jang, Hyo-Jeong,Choi, Youjin,Choi, The Korean Society of Pediatric Gastroenterology 2020 Pediatric gastroenterology, hepatology & nutrition Vol.23 No.1

Purpose: We aimed to investigate the disease phenotype of Korean pediatric Crohn's disease (CD) patients at diagnosis according to the Paris classification by comparison with patients from the European multicenter 5-years recruitment of children with newly developed IBD (EUROKIDS registry). Methods: Korean children and adolescents who had been newly diagnosed with CD at the age of <18 years during 2013-2016 were included in this multicenter retrospective study. Disease phenotype at diagnosis was classified according to the Paris classification, and compared with the published data from the EUROKIDS study. Results: A total of 255 patients were included. The median diagnosis age was 14.7 years (range, 0.8-17.9 years). No significant difference was observed in male-to-female ratio with EUROKIDS (1.9:1 vs. 1.45:1, p=0.062). The proportion of children aged <10 years was significantly lower in Koreans (7.1% vs. 19.6%, p<0.001). Colonic disease was less prominent (10.0% vs. 27.3%, p<0.001), while upper GI involvement was more prominent in Korean children (59.3% vs. 46.2%, p<0.001). The proportion with perianal fistulizing disease at diagnosis was significantly higher in Korean patients (44.8% vs. 8.2%, p<0.001). A separate analysis of Korean patients revealed that perianal fistulizing disease at diagnosis was positively associated with male sex and body mass index z-score (odds ratio [OR]=2.12, 95% confidence interval [CI]=1.20-3.76, p=0.010; and OR=1.29, 95% CI=1.05-1.58, p=0.015, respectively). Conclusion: Approximately half of pediatric CD patients in Korea present with perianal fistulas and/or abscesses at diagnosis, which is a distinct feature of CD in Korean children and adolescents compared to their European counterparts. An underlying genetic difference between ethnicities may play a role in this expression of different phenotypes in pediatric CD.

Resilience and Work-Related Stress May Affect Depressive Symptoms in Nursing Professionals during the COVID-19 Pandemic Era

Youjin Hong,Jukab Lee,Hyuk Joo Lee,Kyumin Kim,Inn-Kyu Cho,Myung Hee Ahn,Yong-Wook Shin,Jangho Park,Seockhoon Chung 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.4

Objective We aimed to investigate the effect of nursing professionals’ resilience on their mental health, work-related stress, and anxiety in response to the COVID-19 pandemic. Methods We conducted an online survey in the Asan Medical Center and Ulsan University Hospital, South Korea. We extracted data of 824 nursing professionals who consented to participate, including demographic variables and the Stress and Anxiety to Viral Epidem-ics-9 (SAVE-9), PHQ-9, GAD-7, and Brief Resilience Scale scores. Results Resilience was negatively correlated with Patient Health Questionnaire-9 (PHQ-9) (rho=-0.23), Generalized Anxiety Scale-7 items (GAD-7) (rho=-0.25), Stress and Anxiety to Viral Epidem-ics-6 items (SAVE-6) (rho=-0.15), and Stress And anxiety to Viral Epidem-ics-3 items (SAVE-3) (rho=-0.13, all, p<0.001). Logistic regression analysis adjusting age, marital status, and years of employment revealed that high level of general anxiety [adjusted odds ratio (aOR)=1.40, 95% confidence interval (CI)=1.31–1.50], work-related stress during viral epidemics (aOR=1.16, 95% CI=1.03–1.29), and a low level of resilience (aOR=0.91, 95% CI=0.85–0.97) were expecting variables for the depression of healthcare workers. Conclusion Nursing professionals’ level of resilience may be associated with low level of work-related stress and anxiety induced by a viral epidemic. We need to explore further the possibility of resilience as coping strategy of healthcare workers in this pandemic era. Psychiatry Investig 2021;18(4):357-363

Increased SCF/c‐kit by hypoxia promotes autophagy of human placental chorionic plate‐derived mesenchymal stem cells via regulating the phosphorylation of mTOR

Lee, Youjin,Jung, Jieun,Cho, Kyung Jin,Lee, Seoung‐,Kwan,Park, Jong‐,Wan,Oh, IL‐,Hoan,Kim, Gi Jin Wiley Subscription Services, Inc., A Wiley Company 2013 Journal of cellular biochemistry Vol.114 No.1

<P><B>Abstract</B></P><P>Hypoxia triggers physiological and pathological cellular processes, including proliferation, differentiation, and death, in several cell types. Mesenchymal stem cells (MSCs) derived from various tissues have self‐renewal activity and can differentiate towards multiple lineages. Recently, it has been reported that hypoxic conditions tip the balance between survival and death by hypoxia‐induced autophagy, although the underlying mechanism is not clear. The objectives of this study are to compare the effect of hypoxia on the self‐renewal of bone marrow‐derived mesenchymal stem cells (BM‐MSCs) and placental chorionic plate‐derived mesenchymal stem cells (CP‐MSCs) and to investigate the regulatory mechanisms of self‐renewal in each MSC type during hypoxia. The expression of self‐renewal markers (e.g., Oct4, Nanog, Sox2) was assessed in both cell lines. PI3K and stem cell factor (SCF) expression gradually increased in CP‐MSCs but were markedly downregulated in BM‐MSCs by hypoxia. The phosphorylation of ERK and mTOR was augmented by hypoxia in CP‐MSCs compared to control. Also, the expression of LC3 II, a component of the autophagosome and the hoof‐shaped autophagosome was detected more rapidly in CP‐MSCs than in BM‐MSCs under hypoxia. Hypoxia induced the expression of SCF in CP‐MSCs and increased SCF/c‐kit pathway promotes the self‐renewal activities of CP‐MSCs via an autocrine/paracrine mechanism that balances cell survival and cell death events by autophagy. These activities occur to a greater extent in CP‐MSCs than in BM‐MSCs through regulating the phosphorylation of mTOR. These findings will provide useful guidelines for better understanding the function of SCF/c‐kit in the self‐renewal and autophagy‐regulated mechanisms that promote of MSC survival. J. Cell. Biochem. 114: 79–88, 2012. © 2012 Wiley Periodicals, Inc.</P>

Removal characterization of ¹³³Cs and ¹²⁷I in a water treatment process using a laboratory scale experiment

Lee, Hee Suk,Lee, Jeongyup,Yoon, Byengsuk,Yim, Youjin,Choi, Ilhwan,Cho, Hyukjin,Lee, Songhee,Baik, Kyounghee,Park, Ju Hyeon,Huh, Yu Jeong IWA Publishing 2013 WATER SCIENCE AND TECHNOLOGY -WATER SUPPLY- Vol.13 No.5

<P>Due to the tragic disaster that happened in Japan and crippled the Fukushima nuclear power plant, serious concerns have been raised regarding the contamination of drinking water as a result of the radioactive materials that were released. Even though the quantities of radioactive material in rain were relatively low, people were concerned about the drinking water. Therefore, there is a need to know the removal efficiency of the unit process of water treatment and to prepare a safety plan to protect the public's health from radioactive materials. In this study, the laboratory scale removal rates were estimated for the coagulation/flocculation, adsorption, and ion exchange processes. The reference standard materials which are stable elements, Cesium-133 (Cs-133) and Iodine-127 (I-127), were used for the typical and advanced water treatment processes at the laboratory scale. For the coagulation/flocculation process, three major coagulants were assessed for this process. However, the removal rates of this process were low. For the adsorption process, powdered activated carbon and zeolites were investigated. The powdered activated carbon showed insignificant removal rates for both reference materials. However, synthetic zeolite was an effective process for Cs-133, and the ion exchange method showed high removal rates for both Cs-133 and I-127.</P>

Water-Dispersible Ferrimagnetic Iron Oxide Nanocubes with Extremely High <i>r</i>₂ Relaxivity for Highly Sensitive in Vivo MRI of Tumors

Lee, Nohyun,Choi, Yoonseok,Lee, Youjin,Park, Mihyun,Moon, Woo Kyung,Choi, Seung Hong,Hyeon, Taeghwan American Chemical Society 2012 NANO LETTERS Vol.12 No.6

<P>The theoretically predicted maximum <I>r</I><SUB>2</SUB> relaxivity of iron oxide nanoparticles was achieved by optimizing the overall size of ferrimagnetic iron oxide nanocubes. Uniform-sized iron oxide nanocubes with an edge length of 22 nm, encapsulated with PEG-phospholipids (WFION), exhibited high colloidal stability in aqueous media. In addition, WFIONs are biocompatible and did not affect cell viability at concentrations up to 0.75 mg Fe/ml. Owing to the enhanced colloidal stability and the high <I>r</I><SUB>2</SUB> relaxivity (761 mM<SUP>–1</SUP> s<SUP>–1</SUP>), it was possible to successfully perform in vivo MR imaging of tumors by intravenous injection of 22-nm-sized WFIONs, using a clinical 3-T MR scanner.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2012/nalefd.2012.12.issue-6/nl3010308/production/images/medium/nl-2012-010308_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl3010308'>ACS Electronic Supporting Info</A></P>

Analysis of high predicted pulmonary function: possibility of overestimation in small elderly examinees

( Youjin Chang ),( Ho Cheol Kim ),( Kyung-wook Jo ),( Jae Seung Lee ),( Yeon-mok Oh ),( Sang Do Lee ),( Sei Won Lee ) 대한내과학회 2020 The Korean Journal of Internal Medicine Vol.35 No.1

Background/Aims: Few studies have attempted to interpret unusually high predicted pulmonary function test results. This study aimed to investigate the demographic features of patients with an unusually high predicted pulmonary function. Methods: The demographic data of subjects who underwent pulmonary function testing at a tertiary referral hospital during between January 2011 and December 2011 were retrospectively reviewed. Results: Of the 68,693 included patients, 55 (0.08%) had a percent predicted forced expiratory volume in 1 second or forced vital capacity ≥ 140%. These patients had a relatively older median age (72 years vs. 54 years, p < 0.001), female predominance (65.5% vs. 42.5%, p = 0.001), lower body weight (52.5 kg vs. 64.5 kg, p < 0.001) and shorter height (148.4 cm vs. 164.2 cm, p < 0.001). Furthermore, 6.1% of women older than 80 years with weight < 50 kg and height < 150 cm had a high predicted pulmonary function. Conclusions: A high predicted pulmonary function is not rare among elderly subjects with a small body size. Physicians should consider the demographics of the examinees, especially those of minority populations, particularly as the test results might be determined using an incorrect reference equation.