1.Development and Validation of a Novel Isotope Dilution-Ultraperformance Liquid ChromatographyTandem Mass Spectrometry Method for Serum C-Peptide
Sung-Eun CHO ; Jungsun HAN ; Juyoung YOU ; Jun Hyung LEE ; Ahram YI ; Sang Gon LEE ; Eun Hee LEE
Annals of Laboratory Medicine 2025;45(1):62-69
Background:
Mass spectrometry (MS) methods exhibit higher accuracy and comparability in measuring serum C-peptide concentrations than immunoassays. We developed and validated a novel isotope dilution-ultraperformance liquid chromatography-tandem MS (IDUPLC-MS/MS) assay to measure serum C-peptide concentrations.
Methods:
Sample pretreatment involved solid-phase extraction, ion-exchange solid-phase extraction, and derivatization with 6-aminoquinolyl-N-hydroxysuccinimidylcarbamate (Cayman Chemical, Ann Arbor, Michigan, USA). We used an ExionLC UPLC system (Sciex, Framingham, MA, USA) and a Sciex Triple Quad 6500 + MS/MS system (Sciex) for electrospray ionization in positive-ion mode with multiple charge states of [M+3H]3+ and multiple reaction monitoring transitions. The total run time was 50 mins, and the flow rate was 0.20 mL/min. We evaluated the precision, trueness, linearity, lower limit of quantitation (LLOQ), carryover, and matrix effects. Method comparison with electrochemiluminescence immunoassay (ECLIA) was performed in 138 clinical specimens.
Results:
The intra- and inter-run precision coefficients of variation were < 5% and the bias values for trueness were < 4%, which were all acceptable. The verified linear interval was 0.050–15 ng/mL, and the LLOQ was 0.050 ng/mL. No significant carryover or matrix effects were observed. The correlation between this ID-UPLC-MS/MS method and ECLIA was good (R = 0.995, slope = 1.564); however, the ECLIA showed a positive bias (51.8%).
Conclusions
The developed ID-UPLC-MS/MS assay shows acceptable performance in measuring serum C-peptide concentrations. This will be useful in situations requiring accurate measurement of serum C-peptide in clinical laboratories.
2.Cancer-Specific Sequences in the Diagnosis and Treatment of NUT Carcinoma
Mi-Sook LEE ; Sungbin AN ; Ji-Young SONG ; Minjung SUNG ; Kyungsoo JUNG ; Eun Sol CHANG ; Juyoung CHOI ; Doo-Yi OH ; Yoon Kyung JEON ; Hobin YANG ; Chaithanya LAKSHMI ; Sehhoon PARK ; Joungho HAN ; Se-Hoon LEE ; Yoon-La CHOI
Cancer Research and Treatment 2023;55(2):452-467
Purpose:
NUT carcinoma (NC) is a solid tumor caused by the rearrangement of NUTM1 that usually develops in midline structures, such as the thorax. No standard treatment has been established despite high lethality. Thus, we investigated whether targeting the junction region of NUTM1 fusion breakpoints could serve as a potential treatment option for NC.
Materials and Methods:
We designed and evaluated a series of small interfering RNAs (siRNAs) targeting the junction region of BRD4-NUTM1 fusion (B4N), the most common form of NUTM1 fusion. Droplet digital polymerase chain reaction using the blood of patients was also tested to evaluate the treatment responses by the junction sequence of the B4N fusion transcripts.
Results:
As expected, the majority of NC fusion types were B4N (12 of 18, 67%). B4N fusion-specific siRNA treatment on NC cells showed specific inhibitory effects on the B4N fusion transcript and fusion protein without affecting the endogenous expression of the parent genes, resulting in decreased relative cell growth and attenuation of tumor size. In addition, the fusion transcript levels in platelet-rich-plasma samples of the NC patients with systemic metastasis showed a negative correlation with therapeutic effect, suggesting its potential as a measure of treatment responsiveness.
Conclusion
This study suggests that tumor-specific sequences could be used to treat patients with fusion genes as part of precision medicine for a rare but deadly disease.
3.Urine biomarkers for monitoring acute kidney injury in premature infants
Yo Han AHN ; Juyoung LEE ; Jiyoung CHUN ; Yong Hoon JUN ; Tae-Jung SUNG
Kidney Research and Clinical Practice 2020;39(3):284-294
Background:
Premature infants are at high risk for acute kidney injury (AKI). Serum creatinine (Cr) has limitations for evaluating kidney function in premature infants. We evaluated whether urine biomarkers could be used to monitor AKI in premature infants.
Methods:
A prospective cohort study was conducted among infants born at < 37 weeks. Urine biomarkers and serum Cr were measured on postnatal days 1, 3, 5, 7, 10, and 14. Infants were divided into 3 groups according to gestational age (GA); < 28, 28 to < 32 and 32 to < 37 weeks.
Results:
AKI occurred in 17 of 83 (20.5%) recruited infants at a median age of 7 (interquartile range 5–10) days. While the most common cause of AKI was hemodynamically significant patent ductus arteriosus (53.8%) in infants of GA < 28 weeks, necrotizing enterocolitis was the leading cause (50.0%) in infants of GA 28 to < 32 weeks. Urinary levels of neutrophil-gelatinase-associated lipocalin/Cr were higher and epidermal growth factor/Cr were lower in AKI group before the onset of AKI in infants of GA < 28 weeks. In infants of GA 28 to < 32 weeks, urinary interleukin-8/Cr levels were higher in AKI group at approximately the time of AKI onset.
Conclusion
Several urine biomarkers were significantly different between AKI and no AKI groups, and some had changed before the onset of AKI. These groups were distinct according to causative factors of AKI and GA. Urine biomarkers could be useful for monitoring the development of AKI in premature infants.
4.PBT-6, a Novel PI3KC2γ Inhibitor in Rheumatoid Arthritis
Juyoung KIM ; Kyung Hee JUNG ; Jaeho YOO ; Jung Hee PARK ; Hong Hua YAN ; Zhenghuan FANG ; Joo Han LIM ; Seong-Ryul KWON ; Myung Ku KIM ; Hyun-Ju PARK ; Soon-Sun HONG
Biomolecules & Therapeutics 2020;28(2):172-183
Phosphoinositide 3-kinase (PI3K) is considered as a promising therapeutic target for rheumatoid arthritis (RA) because of its involvement in inflammatory processes. However, limited studies have reported the involvement of PI3KC2γ in RA, and the underlying mechanism remains largely unknown. Therefore, we investigated the role of PI3KC2γ as a novel therapeutic target for RA and the effect of its selective inhibitor, PBT-6. In this study, we observed that PI3KC2γ was markedly increased in the synovial fluid and tissue as well as the PBMCs of patients with RA. PBT-6, a novel PI3KC2γ inhibitor, decreased the cell growth of TNF-mediated synovial fibroblasts and LPS-mediated macrophages. Furthermore, PBT-6 inhibited the PI3KC2γ expression and PI3K/AKT signaling pathway in both synovial fibroblasts and macrophages. In addition, PBT-6 suppressed macrophage migration via CCL2 and osteoclastogenesis. In CIA mice, it significantly inhibited the progression and development of RA by decreasing arthritis scores and paw swelling. Three-dimensional micro-computed tomography confirmed that PBT-6 enhanced the joint structures in CIA mice. Taken together, our findings suggest that PI3KC2γ is a therapeutic target for RA, and PBT-6 could be developed as a novel PI3KC2γ inhibitor to target inflammatory diseases including RA.
5.Biological effects of blood–brain barrier disruption using a focused ultrasound.
Mun HAN ; Yongki HUR ; Jieun HWANG ; Juyoung PARK
Biomedical Engineering Letters 2017;7(2):115-120
With focused ultrasound (FUS) and microbubbles, BBB can be transiently disrupted with a localized and non-invasive approach. BBB disruption induced by FUS has made progressions to move forward on delivery of therapeutic agents into a brain in a specific area of brain for better treatment of neurological diseases. In addition to be used as an improvement of drug delivery, BBB disruption has been found to induce biological effects such as a clearance of protein aggregation which cause Alzheimer's disease, regulation of proteins which facilitate drug uptake, and modulation of neuronal function and neurogenesis. In this review, we discuss overview about the principles of BBB opening with FUS and milestones in these biological effects of FUS-induced BBB disruption.
Alzheimer Disease
;
Brain
;
Microbubbles
;
Neurogenesis
;
Neurons
;
Ultrasonography*
6.Amniotic Fluid Infection, Cytokine Levels, and Mortality and Adverse Pulmonary, Intestinal, and Neurologic Outcomes in Infants at 32 Weeks' Gestation or Less.
Eun Young JUNG ; Kyo Hoon PARK ; Bo Ryoung HAN ; Soo Hyun CHO ; Ha Na YOO ; Juyoung LEE
Journal of Korean Medical Science 2017;32(3):480-487
To what extent the risks of neonatal morbidities are directly related to premature birth or to biological mechanisms of preterm birth remains uncertain. We aimed to examine the effect of exposure to amniotic fluid (AF) infection and elevated cytokine levels on the mortality and pulmonary, intestinal, and neurologic outcomes of preterm infants, and whether these associations persist after adjustment for gestational age at birth. This retrospective cohort study included 152 premature singleton infants who were born at ≤ 32 weeks. AF obtained by amniocentesis was cultured; and interleukin-6 (IL-6) and IL-8 levels in AF were determined. The primary outcome was adverse perinatal outcome defined as the presence of one or more of the followings: stillbirth, neonatal death, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage, and periventricular leukomalacia. Logistic regression analysis was adjusted for gestational age at birth and other potential confounders. In bivariate analyses, elevated AF IL-6 and IL-8 levels were significantly associated with adverse perinatal outcome. These results were not changed after adjusting for potential confounders, such as low Apgar scores, mechanical ventilation, and surfactant application. However, the independent effect of elevated cytokine levels in AF disappeared when additionally adjusted for low gestational age at birth; consequently, low gestational age remained strongly associated with the risk of adverse perinatal outcome. In conclusion, elevated levels of pro-inflammatory cytokines in AF are associated with increased risk of adverse perinatal outcomes, but this risk is not independent of low gestational age at birth. Culture-proven AF infection is not associated with this risk.
Amniocentesis
;
Amniotic Fluid*
;
Bronchopulmonary Dysplasia
;
Cohort Studies
;
Cytokines
;
Enterocolitis, Necrotizing
;
Female
;
Gestational Age
;
Hemorrhage
;
Humans
;
Infant*
;
Infant, Newborn
;
Infant, Premature
;
Interleukin-6
;
Interleukin-8
;
Leukomalacia, Periventricular
;
Logistic Models
;
Mortality*
;
Parturition
;
Perinatal Death
;
Pregnancy*
;
Premature Birth
;
Respiration, Artificial
;
Retrospective Studies
;
Stillbirth
7.Case Report of Neonatal Proteus mirabilis Meningitis and Brain Abscess with Negative Initial Image Finding: Consideration of Serial Imaging Studies.
Mi Hae CHUNG ; Geonju KIM ; Aluem HAN ; Juyoung LEE
Neonatal Medicine 2017;24(4):187-191
Proteus mirabilis (P. mirabilis) meningitis in a neonate is rare, but its recognition is important because the disease progresses rapidly and has poor prognosis. A 4-day-old premature female infant born at 36 weeks and 5 days of gestation presented with symptoms of fever and icteric skin. Initial cerebrospinal fluid findings suggested bacterial meningitis, and treatment with antibiotics was started. On the third day, P. mirabilis growth was found in both blood and cerebrospinal fluid cultures and brain computed tomography revealed normal findings. The patient showed improved clinical symptoms, but brain magnetic resonance imaging on hospital day 18 revealed a brain abscess measuring 4.5×3.1×3.1 cm in the right frontal lobe. Cyst drainage was performed immediately and a catheter was inserted. Follow-up computed tomography revealed a tiny abscess remaining in the right frontal lobe, and follow-up magnetic resonance imaging later demonstrated marked interval regression in the size of the abscess. The patient was discharged on day 57 of hospitalization in good condition. Serial brain imaging should be considered in neonatal cases of P. mirabilis meningitis.
Abscess
;
Anti-Bacterial Agents
;
Brain Abscess*
;
Brain*
;
Catheters
;
Cerebrospinal Fluid
;
Drainage
;
Female
;
Fever
;
Follow-Up Studies
;
Frontal Lobe
;
Hospitalization
;
Humans
;
Infant
;
Infant, Newborn
;
Magnetic Resonance Imaging
;
Meningitis*
;
Meningitis, Bacterial
;
Mirabilis
;
Neuroimaging
;
Pregnancy
;
Prognosis
;
Proteus mirabilis*
;
Proteus*
;
Skin
8.Serum Chemerin Levels Are Associated with Abdominal Visceral Fat in Type 2 Diabetes.
Juyoung HAN ; So Hun KIM ; Young Ju SUH ; Hyun Ae LIM ; Heekyoung SHIN ; Soon Gu CHO ; Chei Won KIM ; Seung Youn LEE ; Dae Hyung LEE ; Seongbin HONG ; Yong Seong KIM ; Moon Suk NAM
Journal of Korean Medical Science 2016;31(6):924-931
Chemerin is a recently identified adipokine suggested to play a role in obesity and its metabolic complications. The relationship between visceral obesity and serum chemerin levels in type 2 diabetes (T2DM) is unknown and may differ from that of subjects without diabetes. Therefore, we evaluated whether serum chemerin was associated with visceral abdominal obesity in patients with T2DM. A total of 218 Korean patients with T2DM were enrolled and metabolic parameters, abdominal visceral and subcutaneous fat areas, and serum chemerin levels were measured. Serum chemerin level showed positive correlation with fasting insulin, HOMA-IR, serum triglyceride, serum creatinine, urine albumin/creatinine ratio, high-sensitivity C-reactive protein (hsCRP), fibrinogen, abdominal visceral fat area, visceral to subcutaneous fat area ratio, and negatively correlation with high density lipoprotein cholesterol and creatinine clearance (CCr) after adjusting for age, gender and body mass index. Multiple linear stepwise regression analysis showed that abdominal visceral fat area (β = 0.001, P < 0.001), serum triglyceride (β = 0.001, P < 0.001), CCr (β = -0.003, P = 0.001), hsCRP (β = 0.157, P = 0.001), fibrinogen (β = 0.001, P < 0.001) and BMI (β = 0.02, P = 0.008) independently affected log transformed serum chemerin levels. Higher serum chemerin level was associated with higher level of abdominal visceral fat area, serum triglyceride, hsCRP and fibrinogen and lower level of CCr in patients with T2DM. Serum chemerin may be used as a biomarker of visceral adiposity and chemerin may play a role in inflammation, decreased renal function, and increased cardiovascular risk in T2DM.
Adult
;
Biomarkers/blood
;
Body Mass Index
;
C-Reactive Protein/analysis
;
Chemokines/*blood
;
Creatinine/blood/urine
;
Diabetes Mellitus, Type 2/*blood/diagnosis
;
Female
;
Humans
;
Insulin/blood
;
Intercellular Signaling Peptides and Proteins/*blood
;
Intra-Abdominal Fat/*pathology
;
Linear Models
;
Lipocalins/blood
;
Male
;
Middle Aged
;
Obesity/complications
;
Triglycerides/blood
9.Clinical Manifestations of Capillary Hemangiomas in Preterm Infants.
Seon Nyo KIM ; Juyoung LEE ; Seung Han SHIN ; Chang Won CHOI ; Ee Kyung KIM ; Han Suk KIM ; Beyong Il KIM ; Jung Hwan CHOI
Korean Journal of Perinatology 2015;26(3):222-228
PURPOSE: Capillary hemangiomas occur more frequently in preterm infants. We aimed to describe the clinical course of capillary hemangiomas in preterm infants. METHODS: The records of preterm infants with a gestational age (GA) of <35 weeks who were admitted to two tertiary neonatal intensive care units from January 2004 to December 2013 and had capillary hemangiomas were reviewed retrospectively. Subgroup analysis of between infants of GA <30 weeks and GA 30-34+6 weeks were done and ad hoc analysis comparing study population and matched preterm infants without hemangioma for investigation of differences in clinical characteristics. RESULTS: Of the 2,772 preterm infants, 112 (4%) infants developed capillary hemangiomas. The majority (91.9 %) of them had a solitary hemangiomas with the trunk was the most commonly involved site (43%). Three quarters of the patients were treated with topical corticosteroid, propranolol or laser treatment. When we divided this population as who were born before or after GA 30 weeks, there was no difference at postmenstrual age (PMA) of onset of capillary hemangiomas (median [IQR], 36(+4) [30(+5)-40(+5)] vs. 36+2 [33(+6)-41(+1)] weeks, P = 0.275). The age at involution of capillary hemangiomas was also not differ between two groups (median [IQR], 7.75 [3.75-12.25] vs. 7.5 [4-13.75] months, P=0.425). There were no statistical differences between preterm infants with capillary hemangiomas and their age, weight and sex matched control preterm infants without hemangiomas in the neonatal and maternal factors. CONCLUSION: The development of capillary hemangiomas occurred at approximately 36 to 37 weeks of PMA regardless of prematurity in preterm infants. Capillary hemangiomas of preterm infants resolved spontaneously and disappear completely by around 7 months of corrected age.
Capillaries*
;
Gestational Age
;
Hemangioma
;
Hemangioma, Capillary*
;
Humans
;
Infant
;
Infant, Newborn
;
Infant, Premature*
;
Intensive Care Units, Neonatal
;
Propranolol
;
Retrospective Studies
10.The efficacy and safety of Montelukast sodium in the prevention of bronchopulmonary dysplasia.
Sang Bum KIM ; Jang Hoon LEE ; Juyoung LEE ; Seung Han SHIN ; Ho Sun EUN ; Soon Min LEE ; Jin A SOHN ; Han Suk KIM ; Byung Min CHOI ; Min Soo PARK ; Kook In PARK ; Ran NAMGUNG ; Moon Sung PARK
Korean Journal of Pediatrics 2015;58(9):347-353
PURPOSE: The purpose of this study was to evaluate the efficacy and safety of Montelukast sodium in the prevention of bronchopulmonarydysplasia (BPD). METHODS: The Interventional study was designed as a multicenter, prospective, and randomized trial, with open labeled and parallel-experimental groups, 66 infants were enrolled and allocated to either the case group (n=30) or the control group (n=36) based on gestational age (GA). Infants in the case group were given Montelukast sodium (Singulair) based on their body weight (BW). Zero week was defined as the start time of the study. RESULTS: The incidence of moderate to severe BPD was not different between the groups (case group: 13 of 30 [43.3%] vs. control group: 19 of 36 [52.8%], P=0.912). Additionally, secondary outcomes such as ventilation index, mean airway pressure and resort to systemic steroids were not significantly different. There were no serious adverse drug reactions in either group, and furthermore the rate of occurrence of mild drug related-events were not significantly different (case group: 10 of 42 [23.8%] vs. control group: 6 of 48 (15.8%), P=0.414). CONCLUSION: Montelukast was not effective in reducing moderate or severe BPD. There were no significant adverse drug events associated with Montelukast treatment.
Body Weight
;
Bronchopulmonary Dysplasia*
;
Drug-Related Side Effects and Adverse Reactions
;
Gestational Age
;
Health Resorts
;
Humans
;
Incidence
;
Infant
;
Infant, Newborn
;
Infant, Premature
;
Leukotriene Antagonists
;
Pharmacokinetics
;
Prospective Studies
;
Sodium*
;
Steroids
;
Ventilation

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