1,072 results on '"Chang, H.‐A."'
Search Results
2. LTPS Pixel Driving Scheme to Improve Motion Blur for AMOLED Displays
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Jung-Min Lee, Chang H. Kang, Juhn S. Yoo, Han W. Hwang, Soon K. Hong, Yong M. Ha, Hyean C. Choi, and Byeong-Kwon Ju
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Electrical and Electronic Engineering ,Electronic, Optical and Magnetic Materials - Published
- 2022
3. Pharmacology of Local Anesthetics
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Chang H. Park and Garrett W. Burnett
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- 2023
4. Analgesic options for anterior approach to scoliosis repair: a scoping review
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Chris J. Li, John R. Vaile, Jonathan S. Gal, Chang H. Park, and Garrett W. Burnett
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Orthopedics and Sports Medicine - Published
- 2023
5. Data from Expanding the Repertoire for 'Large Small Molecules': Prodrug ABBV-167 Efficiently Converts to Venetoclax with Reduced Food Effect in Healthy Volunteers
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Andrew J. Souers, Nathaniel D. Catron, Geoff G.Z. Zhang, Xilu Wang, Ahmed A. Suleiman, Deanne Stolarik, Yi Shi, Ahmad Y. Sheikh, Yeshwant D. Sanzgiri, Saul H. Rosenberg, Yu-Ming Pu, Darren C. Phillips, Chang H. Park, Rajeev M. Menon, Kennan C. Marsh, Richard A. Marks, Joel D. Leverson, Yi-Yin Ku, Russell C. Klix, John C. Kalvass, Russell A. Judge, Jianguo Ji, Gary J. Jenkins, Richard Hong, Kaid C. Harper, Keith M. Fournier, Steven W. Elmore, Rohinton Edalji, Shuang Chen, Jie Chen, Orlando F. Bueno, Zhi-Fu Tao, and Ahmed Hamed Salem
- Abstract
Since gaining approval for the treatment of chronic lymphocytic leukemia (CLL), the BCL-2 inhibitor venetoclax has transformed the treatment of this and other blood-related cancers. Reflecting the large and hydrophobic BH3-binding groove within BCL-2, venetoclax has significantly higher molecular weight and lipophilicity than most orally administered drugs, along with negligible water solubility. Although a technology-enabled formulation successfully achieves oral absorption in humans, venetoclax tablets have limited drug loading and therefore can present a substantial pill burden for patients in high-dose indications. We therefore generated a phosphate prodrug (3, ABBV-167) that confers significantly increased water solubility to venetoclax and, upon oral administration to healthy volunteers either as a solution or high drug-load immediate release tablet, extensively converts to the parent drug. Additionally, ABBV-167 demonstrated a lower food effect with respect to venetoclax tablets. These data indicate that beyond-rule-of-5 molecules can be successfully delivered to humans via a solubility-enhancing prodrug moiety to afford robust exposures of the parent drug following oral dosing.
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- 2023
6. Supplementary Data from Expanding the Repertoire for 'Large Small Molecules': Prodrug ABBV-167 Efficiently Converts to Venetoclax with Reduced Food Effect in Healthy Volunteers
- Author
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Andrew J. Souers, Nathaniel D. Catron, Geoff G.Z. Zhang, Xilu Wang, Ahmed A. Suleiman, Deanne Stolarik, Yi Shi, Ahmad Y. Sheikh, Yeshwant D. Sanzgiri, Saul H. Rosenberg, Yu-Ming Pu, Darren C. Phillips, Chang H. Park, Rajeev M. Menon, Kennan C. Marsh, Richard A. Marks, Joel D. Leverson, Yi-Yin Ku, Russell C. Klix, John C. Kalvass, Russell A. Judge, Jianguo Ji, Gary J. Jenkins, Richard Hong, Kaid C. Harper, Keith M. Fournier, Steven W. Elmore, Rohinton Edalji, Shuang Chen, Jie Chen, Orlando F. Bueno, Zhi-Fu Tao, and Ahmed Hamed Salem
- Abstract
1. Measured pKa values of ABBV-167 (Table S1. Ionization constants of ABBV-167) 2. Preparation of ABBV-167 on large scale (Scheme S1: Synopsis of GMP synthesis of ABBV-167) 3. Preparation of clinical ABBV-167 drug supply 4. Animal pharmacokinetics (Table S2. Single dose pharmacokinetics of prodrug 3 and parent venetoclax in mouse and dog after IV dosing of prodrug 3. Table S3. Single dose pharmacokinetics of 3 after oral dosing in mouse and dog. Table S4. Single dose pharmacokinetics of parent venetoclax in mouse and dog after oral dosing of 3.) 5. Clinical study (Study design, Pharmacokinetic and statistical analysis, Safety and tolerability assessments, Clinical pharmacokinetic results, Table S5. Effect of prodrug and food on venetoclax bioavailability, Safety results) 6. Crystallography methods (Protein preparation. BCL-2 ABBV-167 complex crystallization. X-ray structure determination. Table S6. Diffraction data collection and refinement statistics for BCL-2 in complex with ABBV-167 (PDB code 7LHB))
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- 2023
7. Supplementary Data from In vivo Diagnosis of Epidermal Growth Factor Receptor Expression using Molecular Imaging with a Cocktail of Optically Labeled Monoclonal Antibodies
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Hisataka Kobayashi, Peter L. Choyke, Yasuteru Urano, Chang H. Paik, Beom-Su Jang, In Soo Shin, Gregory Ravizzini, Yukihiro Hama, Yoshinori Koyama, and Tristan Barrett
- Abstract
Supplementary Data from In vivo Diagnosis of Epidermal Growth Factor Receptor Expression using Molecular Imaging with a Cocktail of Optically Labeled Monoclonal Antibodies
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- 2023
8. Data from In vivo Diagnosis of Epidermal Growth Factor Receptor Expression using Molecular Imaging with a Cocktail of Optically Labeled Monoclonal Antibodies
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Hisataka Kobayashi, Peter L. Choyke, Yasuteru Urano, Chang H. Paik, Beom-Su Jang, In Soo Shin, Gregory Ravizzini, Yukihiro Hama, Yoshinori Koyama, and Tristan Barrett
- Abstract
Purpose: Epidermal growth factor receptors (EGFR) play an important role in tumorigenesis and, therefore, have become targets for new molecular therapies. Here, we use a “cocktail” of optically labeled monoclonal antibodies directed against EGFR-1 (HER1) and EGFR-2 (HER2) to distinguish tumors by their cell surface expression profiles.Experimental Design:In vivo imaging experiments were done in tumor-bearing mice following s.c. injection of A431 (overexpressing HER1), NIH3T3/HER2+ (overexpressing HER2), and Balb3T3/DsRed (non-expression control) cell lines. After tumor establishment, a cocktail of optically labeled antibodies: Cy5.5-labeled cetuximab (anti-HER1) and Cy7-labeled trastuzumab (anti-HER2) was i.v. injected. In vivo and ex vivo fluorescence imaging was done. For comparison with radionuclide imaging, experiments were undertaken using 111Indium-labeled antibodies. Additionally, a “blinded” diagnostic study was done for mice bearing one tumor type.Results:In vivo spectral fluorescent molecular imaging of 14 mice with three tumor types clearly differentiated tumors using the cocktail of optically labeled antibodies both in vivo and ex vivo. Twenty-four hours after injection, A431 and NIH3T3/HER2+ tumors were detected distinctly by their peak on Cy5.5 and Cy7 spectral images, respectively; radionuclide imaging was unable to clearly distinguish tumors at this time point. In blinded single tumor experiments, investigators were able to correctly diagnose a total of 40 tumors.Conclusion: An in vivo imaging technique using an antibody cocktail simultaneously differentiated two tumors expressing distinct EGFRs and enabled an accurate characterization of each subtype.
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- 2023
9. Parameterization of polydisperse aerosol optical properties during hygroscopic growth
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Jung, Chang H., Han, Kyung Man, Yoon, Young Jun, Kim, Dongchul, Lee, Ji Yi, Lee, Hyung-Min, Um, J., Lee, S. S., and Kim, Yong Pyo
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Environmental Chemistry ,General Materials Science ,Pollution - Abstract
Aerosol water uptake and the related influence on its optical properties owing to the hygroscopic growth of polydisperse aerosols have a significant effect on air quality and climate. This study develops an analytical parameterization for a single hygroscopic optical parameter and the scattering enhancement factor for polydisperse aerosol sizes. Polydisperse lognormal size distributions for geometric mean diameters of 0.05–1 µm and geometric standard deviations of 1.3–2.5 are considered with real refractive indices between 1.35 and 1.6. The analytical expression obtained for the optical parameter is compared to Mie theory and reasonable agreements within the size range investigated in this study are observed. Further, our results show that the analytical expression could express polydispersed aerosol optical properties as a function of geometric mean diameter and geometric standard deviation of a lognormal distribution and the refractive index. The obtained analytical expression can be efficiently used for 3D models with a reduced computational burden. Copyright © 2023 American Association for Aerosol Research
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- 2023
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10. Toward sustainable express deliveries for online shopping: Reusing packaging materials through reverse logistics
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Nai Yeen Gavin Lai, Adrian T. H. Kuah, Chang H. Kim, and Kok Hoong Wong
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Political Science and International Relations ,Geography, Planning and Development ,Business and International Management - Published
- 2022
11. Morphology for circular economy business models in the electrical and electronic equipment sector of Singapore and South Korea: Findings, implications, and future agenda
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Chang H. Kim, Adrian T.H. Kuah, and K. Thirumaran
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Environmental Engineering ,Renewable Energy, Sustainability and the Environment ,Environmental Chemistry ,Industrial and Manufacturing Engineering - Published
- 2022
12. Machine Learning Estimation of Low-Density Lipoprotein Cholesterol in Women With and Without HIV
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Sanjay Rajagopalan, Chris T. Longenecker, Tony Dong, Chang H. Kim, Mariam N. Rana, and Sadeer G. Al-Kindi
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Adult ,Coefficient of determination ,Mean squared error ,HIV Infections ,Machine learning ,computer.software_genre ,Machine Learning ,Linear regression ,Humans ,Pharmacology (medical) ,Triglycerides ,Mathematics ,Estimation ,Artificial neural network ,business.industry ,Cholesterol, HDL ,Cholesterol, LDL ,Middle Aged ,Random forest ,Support vector machine ,Infectious Diseases ,Female ,Gradient boosting ,Artificial intelligence ,business ,computer - Abstract
Low-density lipoprotein cholesterol (LDL-C) is typically estimated from total cholesterol, high-density lipoprotein cholesterol, and triglycerides. The Friedewald, Martin-Hopkins, and National Institutes of Health equations are widely used but may estimate LDL-C inaccurately in certain patient populations, such as those with HIV. We sought to investigate the utility of machine learning for LDL-C estimation in a large cohort of women with and without HIV.We identified 7397 direct LDL-C measurements (5219 from HIV-infected individuals, 2127 from uninfected controls, and 51 from seroconvertors) from 2414 participants (age 39.4 ± 9.3 years) in the Women's Interagency HIV Study and estimated LDL-C using the Friedewald, Martin-Hopkins, and National Institutes of Health equations. We also optimized 5 machine learning methods [linear regression, random forest, gradient boosting, support vector machine (SVM), and neural network] using 80% of the data (training set). We compared the performance of each method using root mean square error, mean absolute error, and coefficient of determination (R2) in the holdout (20%) set.SVM outperformed all 3 existing equations and other machine learning methods, achieving the lowest root mean square error and mean absolute error, and the highest R2 (11.79 and 7.98 mg/dL, 0.87, respectively, compared with those obtained using the Friedewald equation: 12.45 and 9.14 mg/dL, 0.87). SVM performance remained superior in subgroups with and without HIV, with nonfasting measurements, in LDL70 mg/dL and triglycerides400 mg/dL.In this proof-of-concept study, SVM is a robust method that predicts directly measured LDL-C more accurately than clinically used methods in women with and without HIV. Further studies should explore the utility in broader populations.
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- 2022
13. Promoting effect of CO on low-temperature NOx adsorption over Pd/CeO2 catalyst
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Jaeha Lee, Sungha Hwang, Hyokyoung Lee, Do Heui Kim, Changho Jeong, Chang H. Kim, Yongwoo Kim, and Eunwon Lee
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chemistry.chemical_element ,Selective catalytic reduction ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen ,Catalysis ,0104 chemical sciences ,Adsorption ,chemistry ,Chemical engineering ,0210 nano-technology ,NOx - Abstract
Passive NOx adsorbers (PNA) adsorb NOx at low temperatures and release NOx at high temperatures, at which downstream catalytic systems, such as selective catalytic reduction catalysts, operate efficiently and can remove NOx. Pd/CeO2 is a promising catalyst for PNA applications. In this study, the promoting effect of CO on the NOx adsorption ability of Pd/CeO2 at low temperatures was investigated. The amount of NOx adsorbed significantly increased when CO was added to the feed gas. Specifically, during the first 10 min, the amount of adsorbed NOx increased more than six times in the presence of CO. A mechanism for the promoting effect of CO on low-temperature NOx adsorption was suggested by considering the decreased CO oxidation ability with increasing amount of NOx adsorbed over Pd/CeO2. The model proposes that NOx was readily adsorbed by the oxygen vacancies of CeO2 adjacent to the Pd particles, which were generated during CO oxidation, resulting in an increase in NOx adsorption. A better understanding of the CO and NO interactions would contribute to the development of ceria-based PNA materials.
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- 2022
14. Identification of the niche and mobilization mechanism for tissue-protective multipotential bone marrow ILC progenitors
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Qingyang Liu, Jun Hee Lee, Hyun Min Kang, and Chang H. Kim
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Multidisciplinary - Abstract
Innate lymphoid cells (ILCs) play crucial roles in maintenance and defense of peripheral tissues but would undergo natural and inflammation-induced attrition over time. A potential solution to counteract the peripheral ILC attrition would be regulated mobilization of bone marrow (BM) ILC progenitors. The major multipotential ILC progenitors (ILCPs) are divided into two subsets in distinct niches of the BM. Sinusoid ILCPs emigrate from the BM to circulate the peripheral blood. In contrast, parenchyma ILCPs are more likely in cell cycling and less likely to emigrate BM. The mobilization of BM ILCPs is internally and externally controlled by the coordinated expression of the BM retention receptors (Itg-α4 and CXCR4) and the emigration receptors sphingosine-1-phosphate (S1P) receptors. The expression of the BM retention and emigration receptors is developmentally regulated in the steady state and by the inflammasome-derived IL-18. Upon infusion, sinusoid ILCPs can effectively restore peripheral ILC insufficiency and tissue integrity during inflammatory responses.
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- 2022
15. Influenza vaccination: a call for cardiologists
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Chang H Kim, Francoise A Marvel, and Seth S Martin
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Cardiologists ,Epidemiology ,Cardiovascular Diseases ,Risk Factors ,Heart Disease Risk Factors ,Influenza, Human ,Vaccination ,Humans ,Cardiology and Cardiovascular Medicine - Published
- 2022
16. The Sec1–Munc18 protein VPS33B forms a uniquely bidirectional complex with VPS16B
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Richard J.Y. Liu, Yusef Al-Molieh, Shao Z. Chen, Marko Drobac, Denisa Urban, Chang H. Chen, Helen H.Y. Yao, Ryan S.Q. Geng, Ling Li, Fred G. Pluthero, Samir Benlekbir, John L. Rubinstein, and Walter H.A. Kahr
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Cell Biology ,Molecular Biology ,Biochemistry - Published
- 2023
17. The Butyrate-Producing Bacterium Clostridium butyricum Suppresses Clostridioides difficile Infection via Neutrophil- and Antimicrobial Cytokine–Dependent but GPR43/109a-Independent Mechanisms
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Chang H. Kim, Sho Kitamoto, Atsushi Hayashi, Nobuhiko Kamada, and Hiroko Nagao-Kitamoto
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biology ,Chemistry ,medicine.drug_class ,medicine.medical_treatment ,Immunology ,Antibiotics ,Butyrate ,medicine.disease ,biology.organism_classification ,Microbiology ,law.invention ,03 medical and health sciences ,Probiotic ,0302 clinical medicine ,Immune system ,Cytokine ,law ,Immunity ,medicine ,Immunology and Allergy ,Colitis ,Clostridium butyricum ,030215 immunology - Abstract
Short-chain fatty acids, such as butyrate, are major gut microbial metabolites that are beneficial for gastrointestinal health. Clostridium butyricum MIYAIRI588 (CBM588) is a bacterium that produces a robust amount of butyrate and therefore has been used as a live biotherapeutic probiotic in clinical settings. Clostridioides difficile causes life-threatening diarrhea and colitis. The gut resident microbiota plays a critical role in the prevention of C. difficile infection (CDI), as the disruption of the healthy microbiota by antibiotics greatly increases the risk for CDI. We report that CBM588 treatment in mice significantly improved clinical symptoms associated with CDI and increased the number of neutrophils and Th1 and Th17 cells in the colonic lamina propria in the early phase of CDI. The protective effect of CBM588 was abolished when neutrophils, IFN-γ, or IL-17A were depleted, suggesting that induction of the immune reactants is required to elicit the protective effect of the probiotic. The administration of tributyrin, which elevates the concentration of butyrate in the colon, also increased the number of neutrophils in the colonic lamina propria, indicating that butyrate is a potent booster of neutrophil activity during infection. However, GPR43 and GPR109a, two G protein–coupled receptors activated by butyrate, were dispensable for the protective effect of CBM588. These results indicate that CBM588 and butyrate suppress CDI, in part by boosting antimicrobial innate and cytokine-mediated immunity.
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- 2021
18. ODP028 Association Between Serum Steroid Profile and Metabolic Risks in Adults with Classic Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency
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Chang H Ahn, Jaeyoon Shim, Han N Jang, Young A Lee, Man H Choi, and Jung Hee Kim
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Endocrinology, Diabetes and Metabolism - Abstract
Objective In adult patients with congenital adrenal hyperplasia (CAH), long-term health outcomes, including metabolic and cardiovascular health, are a priority for the management of CAH. The enzyme 21-hydroxylase deficiency, which accounts for a majority of CAH, leads to a large perturbation in serum steroid profile under glucocorticoid replacement therapy. Serum levels of several adrenal steroids, including 17-hydroxyprogesterone and androstenedione, are associated with disease severity and sexual dysfunction of CAH patients. However, the association between the serum steroid profiles with metabolic risk in CAH patients is not elucidated yet. We aimed to investigate the serum steroid profile of adult CAH patients using liquid chromatography-mass spectrometry (LC-MS) and their association with metabolic risk. Methods Adult patients with classic CAH due to 21-hydroxylase deficiency were included in this study (36 females and 27 males). A multi-steroid panel composed of 25 steroids and their metabolites was applied to morning serum samples of study subjects using LC-MS. An unsupervised clustering algorithm was applied to the serum steroid panel to discover any unique pattern which divides CAH subjects into clusters. The association between serum steroid profiles and clinical characteristics, including age, sex, body mass index (BMI), subtypes (simple virilizing and salt wasting), glucocorticoid dose, and the presence of hypertension, diabetes mellitus (DM), and metabolic syndrome (MetS) was analyzed. The discriminatory power of each steroid or a combination of steroids was estimated using the area under the curve of receiver operating characteristics (AUROC) for metabolic diseases. Results Fifteen steroids including pregnenolone sulfate, 17α-hydroxyprogesterone, cortisol, cortisone, 21-deoxycortisol, 20α-dihydrocortisol, 20α-dihydrocortisone, α-cortolone, β-cortolone, tetrahydrocortisone, dehydroepiandrosterone sulfate, testosterone, androstenedione, 11β-hydroxytestosterone, and 11β-hydroxyandrostenedione were successfully quantified in all subjects. The median age of subjects was 28 years (interquartile range: 25-35). The prevalence of DM, hypertension, and MetS was 3.2% (2/63), 15.8% (10/63), and 28.6% (18/63), respectively. The subjects were divided into two clusters based on the pattern of serum steroid profile using unsupervised hierarchical clustering. The prevalence of MetS was significantly different between the two clusters (cluster 1, 37.8% [17/45] vs. cluster 2, 5.6% [1/18], P = 0. 011). The prevalence of HTN was numerically higher in cluster 1 than cluster 2 (20. 0% [9/45] vs. 5.6% [1/18], P = 0.257). Other clinical characteristics, including age, sex, BMI, subtypes, and glucocorticoid dose, were not different between the two clusters. Among fifteen steroids, the level of tetrahydrocortisone showed the highest discriminatory power for MetS (AUROC 0.795, 95% confidence interval: 0.675-0.914). The multivariate logistic regression model of all 15 steroids showed AUROC of 0.832 (95% CI: 0.732-0.933) for MetS. Conclusion The serum steroid profiles of CAH patients were significantly associated with the presence of MetS. This suggests that serum steroid signatures can guide the optimal management of adult CAH patients to minimize the risk of MetS. Presentation: No date and time listed
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- 2022
19. Long-term outcomes of primary total knee arthroplasty in patients with hepatitis B virus infection
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Ji-Hoon Baek, Su C. Lee, Suengryol Ryu, Jin-Woo Kim, and Chang H. Nam
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General Engineering - Abstract
Aims The purpose of this study was to compare the clinical outcomes, mortalities, implant survival rates, and complications of total knee arthroplasty (TKA) in patients with or without hepatitis B virus (HBV) infection over at least ten years of follow-up. Methods From January 2008 to December 2010, 266 TKAs were performed in 169 patients with HBV (HBV group). A total of 169 propensity score–matched patients without HBV were chosen for the control group in a one-to-one ratio. Then, the clinical outcomes, mortalities, implant survival rates, and complications of TKA in the two groups were compared. The mean follow-up periods were 11.7 years (10.5 to 13.4) in the HBV group and 11.8 years (11.5 to 12.4) in the control group. Results The mean Knee Society scores in the HBV and control groups improved from 37.1 (SD 5.6) and 38.4 (SD 5.4) points preoperatively to 78.1 (SD 10.8) and 81.7 (SD 10.2) points at final follow-up (p = 0.314), while the mean function scores in the HBV and control groups improved from 36.2 and 37.3 points preoperatively to 77.8 and 83.2 points at final follow-up (p = 0.137). Nine knees in the HBV group required revision surgery, including seven due to septic loosening and two due to aseptic loosening. Four knees in the control group required revision surgery, including three due to septic loosening and one due to aseptic loosening. Kaplan–Meier survivorship analysis with the revision of either component as an endpoint in the HBV and control groups estimated 96.6% and 98.5% chances of survival for ten years, respectively (p = 0.160). Conclusion TKA in patients with HBV infection resulted in good clinical outcomes and survivorship. However, there was a higher revision rate over a minimum ten-year follow-up period compared to TKA in patients without HBV infection. Cite this article: Bone Jt Open 2022;3(6):470–474.
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- 2022
20. Cutting Edge: The Expression of Transcription Inhibitor GFI1 Is Induced by Retinoic Acid to Rein in Th9 Polarization
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Leon Friesen, Raymond Kostlan, Qingyang Liu, Hao Yu, Jinfang Zhu, Nicholas Lukacs, and Chang H. Kim
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Receptors, Steroid ,Immunology ,Interleukin-9 ,Tretinoin ,Immunity, Innate ,DNA-Binding Proteins ,Histones ,Transforming Growth Factor beta1 ,Mice ,Immunology and Allergy ,Animals ,Interleukin-4 ,Lymphocytes ,Transcription Factors - Abstract
IL-9, produced mainly by specialized T cells, mast cells, and group 2 innate lymphoid cells, regulates immune responses, including anti-helminth and allergic responses. Polarization of naive CD4 T cells into IL-9–producing T cells (Th9s) is induced by IL-4 and TGF-β1 or IL-1β. In this article, we report that the transcription factor growth factor–independent 1 transcriptional repressor (GFI1) plays a negative role in mouse Th9 polarization. Moreover, the expression of GFI1 is controlled by liganded RARα, allowing GFI1 to mediate the negative effect of retinoic acid on IL-9 expression. The Gfi1 gene has multiple RARα binding sites in the promoter region for recruiting nuclear coactivator steroid receptor coactivator-3 and p300 for histone epigenetic modifications in a retinoic acid–dependent manner. Retinoic acid–induced GFI1 binds the Il9 gene and suppresses its expression. Thus, GFI1 is a novel negative regulator of Il9 gene expression. The negative GFI1 pathway for IL-9 regulation provides a potential control point for Th9 activity.
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- 2022
21. Geographic Variation in Disease Burden Among Patients with Severe Persistent Asthma in the US
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Rane, P., Carlos Camargo, Beck, A. F., Wang, Y., Chung, Y., Mcguiness, K., Ackert, J. Llanos, Lindsley, A. W., Ambrose, C. S., Zhou, Z., Chang, H., and Wade, R. L.
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- 2022
22. Dietary fiber metabolites regulate innate lymphoid cell responses
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Qingyang Liu, Chang H. Kim, Leon Friesen, and Ali Sepahi
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Dietary Fiber ,STAT3 Transcription Factor ,Microbial metabolites ,G-protein-coupled receptor ,Immunology ,Innate lymphoid cells ,Biology ,Article ,Receptors, G-Protein-Coupled ,Mice ,Phosphatidylinositol 3-Kinases ,Short-chain fatty acids ,Mediator ,Animals ,Immunology and Allergy ,Lymphocytes ,skin and connective tissue diseases ,Receptor ,STAT3 ,Cells, Cultured ,STAT5 ,PI3K/AKT/mTOR pathway ,Cell Proliferation ,G protein-coupled receptor ,Mice, Knockout ,Microbiota ,Innate lymphoid cell ,Cell Differentiation ,Fatty Acids, Volatile ,Immunity, Innate ,Up-Regulation ,Cell biology ,Mice, Inbred C57BL ,body regions ,biology.protein ,Function (biology) ,Signal Transduction - Abstract
Summary Innate lymphoid cells (ILCs) rapidly undergo expansion in population size and functional maturation in response to cytokines that signal infection, tissue damage or changes in physiology. Optimal ILC responses are shaped, in part, by the microbiota but the mechanisms remain unclear. We report that short-chain fatty acids (SCFAs), produced by the commensal microbiota from dietary fibers, support optimal expansion of ILCs, including ILC1, ILC2 and ILC3 in the intestines through their G-protein-coupled receptors (GPCRs). While this function is primarily important for intestinal ILC populations, it can also boost ILC responses in other tissues depending on host condition. ILCs express multiple GPCRs that detect SCFAs. Interestingly, we found that the expression of SCFA receptors, such as Ffar2 and Ffar3, by ILCs is induced by SCFAs. GPCR triggering by SCFAs co-stimulates the activation of Phosphoinositide 3-kinase (PI3K), Stat3, Stat5, and mammalian target of rapamycin (mTOR), which is important for ILC proliferation. While Ffar2 signaling promotes ILC2 proliferation, SCFAs can suppress ILC2 proliferation through a non-Ffar2-mediated mechanism. In conclusion, our findings indicate that SCFAs, as the major mediator of healthy microbiota and nutritional status, function to maintain optimal numbers of ILCs in peripheral tissues during infection and inflammatory responses.
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- 2021
23. Digital and traditional media advertising and business performance of agribusiness firms - Empirical evidence in Japan
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Y Kitamura, Chung Y.C.Y, and Chang H.-H
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Advertising ,Business ,Empirical evidence ,General Economics, Econometrics and Finance ,Agricultural and Biological Sciences (miscellaneous) ,Agribusiness - Published
- 2021
24. A ligand-independent fast function of RARα promotes exit from metabolic quiescence upon T cell activation and controls T cell differentiation
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Chang H. Kim, Leon Friesen, and B Gu
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Regulatory T cell ,T-Lymphocytes ,T cell ,Immunology ,Retinoic acid ,Mice, Transgenic ,Lymphocyte Activation ,Resting Phase, Cell Cycle ,Article ,Mice ,chemistry.chemical_compound ,T-Lymphocyte Subsets ,Gene expression ,medicine ,Animals ,Humans ,Immunology and Allergy ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Mice, Knockout ,Chemistry ,Effector ,Retinoic Acid Receptor alpha ,TOR Serine-Threonine Kinases ,Cell Differentiation ,Mitochondria ,Cell biology ,medicine.anatomical_structure ,T cell differentiation ,Energy Metabolism ,Proto-Oncogene Proteins c-akt - Abstract
Vitamin A metabolites play important roles in T cell activation and differentiation. A conventional model of RARα function relies upon retinoic acid (RA)-liganded RARα binding to specific DNA motifs to regulate gene expression in the nucleus. However, this genomic function fails to explain many of the biological responses of the RA-RARα axis on T cells. We generated a mouse line where RARα is over-expressed in T cells to probe RARα function with unprecedented sensitivity. Using this model together with mice specifically lacking RARα in T cells, we found that RARα is required for prompt exit from metabolic quiescence in resting T cells upon T cell activation. The positive effect of RARα on metabolism is mediated through PI3K and subsequent activation of the Akt and mTOR signaling pathway. This largely non-genomic function of RARα is surprisingly ligand-independent and controls the differentiation of effector and regulatory T cell subsets.
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- 2021
25. IL-4–BATF signaling directly modulates IL-9 producing mucosal mast cell (MMC9) function in experimental food allergy
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Simon P. Hogan, Varsha Ganesan, Richard Lee Reinhardt, Richard A. Flavell, Yui-Hsi Wang, Ankit Sharma, Chang Zeng, Chang H. Kim, Lisa Waggoner, Sunil Tomar, Paula Licona-Limón, and Andrew Smith
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0301 basic medicine ,Immunology ,Stem cell factor ,Biology ,Article ,Transcriptome ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Food allergy ,BATF ,medicine ,Animals ,Immunology and Allergy ,Interleukin 9 ,Mast Cells ,Intestinal Mucosa ,Receptor ,Interleukin 4 ,Mice, Knockout ,Interleukin-9 ,medicine.disease ,Mast cell ,Cell biology ,Disease Models, Animal ,Basic-Leucine Zipper Transcription Factors ,030104 developmental biology ,medicine.anatomical_structure ,Interleukin-4 ,Food Hypersensitivity ,Signal Transduction ,030215 immunology - Abstract
Background This study group has previously identified IL-9–producing mucosal mast cell (MMC9) as the primary source of IL-9 to drive intestinal mastocytosis and experimental IgE-mediated food allergy. However, the molecular mechanisms that regulate the expansion of MMC9s remain unknown. Objectives This study hypothesized that IL-4 regulates MMC9 development and MMC9-dependent experimental IgE-mediated food allergy. Methods An epicutaneous sensitization model was used and bone marrow reconstitution experiments were performed to test the requirement of IL-4 receptor α (IL-4Rα) signaling on MMC9s in experimental IgE-mediated food allergy. Flow cytometric, bulk, and single-cell RNA-sequencing analyses on small intestine (SI) MMC9s were performed to illuminate MMC9 transcriptional signature and the effect of IL-4Rα signaling on MMC9 function. A bone marrow–derived MMC9 culture system was used to define IL-4–BATF signaling in MMC9 development. Results Epicutaneous sensitization– and bone marrow reconstitution–based models of IgE-mediated food allergy revealed an IL-4 signaling-dependent cell-intrinsic effect on SI MMC9 accumulation and food allergy severity. RNA-sequencing analysis of SI-MMC9s identified 410 gene transcripts reciprocally regulated by IL-4 signaling, including Il9 and Batf. In silico analyses identified a 3491-gene MMC9 transcriptional signature and identified 2 transcriptionally distinct SI MMC9 populations enriched for metabolic or inflammatory programs. Employing an in vitro MMC9-culture model system showed that generation of MMC9-like cells was induced by IL-4 and this was in part dependent on BATF. Conclusions IL-4Rα signaling directly modulates MMC9 function and exacerbation of experimental IgE-mediated food allergic reactions. IL-4Rα regulation of MMC9s is in part BATF-dependent and occurs via modulation of metabolic transcriptional programs.
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- 2021
26. Interplay of ligand and strain effects in CO adsorption on bimetallic Cu/M (M = Ni, Ir, Pd, and Pt) catalysts from first-principles: Effect of different facets on catalysis
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Jin Woo Choung, Chang H. Kim, Hyung Chul Ham, Kwan Young Lee, Deok Yeon Jo, and Min Woo Lee
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Materials science ,Ligand ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,Water-gas shift reaction ,0104 chemical sciences ,chemistry.chemical_compound ,Adsorption ,chemistry ,Transition metal ,Physical chemistry ,Density functional theory ,0210 nano-technology ,Bimetallic strip ,Carbon monoxide - Abstract
Cu-based catalysts have been variously used in the water gas shift reaction (WGSR) and methanol synthesis, both of which use carbon monoxide as a common reactant. According to the Bell–Evans–Polanyi principle, CO adsorption energies (Eads,CO) directly affect the activation energies for CO hydrogenation. Thus, the understanding of the relationship between Eads,CO and the chemical properties of the catalytic surface is fundamental to catalyst design. In particular, recent studies have shown that effective catalysts can be developed by controlling the exposed facets or forming alloys with other transition metal to enhance the mechanical and electronic characteristics. In bimetallic catalysts, two types of chemical effects are known to determine the adsorption energies: one is the “strain” effect caused by lattice mismatch and the other is the “ligand” effect, generated by the change in orbital electrons. We conducted calculations on Cu/M(100), (111), and (211) surfaces (M = Ni, Ir, Pd and Pt) by using spin-polarized density functional theory (DFT) calculations to find the dominant factor, as well as trends, affecting CO adsorption. Our calculations suggest the ligand effect is the dominant contribution to Eads,CO, regardless of the type of facets. We also determined that the ligand contribution is caused by the loss of electrons from the surface Cu atoms. As a result, a proportional correlation between ligand contribution and electron charge transfer was observed. On investigating the strain effect on the (111) facet, we found that the results are consistent with d-band theory, while the Eads,CO on (100) and (211) facets showed the opposite trend.
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- 2021
27. Deactivation of Pd/Zeolites passive NOx adsorber induced by NO and H2O: Comparative study of Pd/ZSM-5 and Pd/SSZ-13
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Do Heui Kim, Yongwoo Kim, Eunwon Lee, Sungha Hwang, Chang H. Kim, Hyokyoung Lee, and Jaeha Lee
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Chemistry ,Sintering ,NO storage ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,0104 chemical sciences ,SSZ-13 ,Adsorption ,Chemical engineering ,ZSM-5 ,0210 nano-technology ,NOx adsorber ,NOx - Abstract
Atomically dispersed Pd in Zeolites can adsorb NO to reduce NOx emission from vehicle exhausts at low temperature. In this contribution, low temperature NO adsorption abilities of Pd/ZSM-5 and Pd/SSZ-13 are comparatively studied. Co-adsorption of NO and H2O on Pd/ZSM-5 induced PdO sintering and deactivated NO adsorption ability. On the other hand, NO adsorption ability of Pd/SSZ-13 was maintained from the 500 °C treatment under NO and H2O where PdO sintering did not occur. Therefore, Pd/SSZ-13 would be the better candidate as NO storage material to reduce NOx emission from vehicle exhaust.
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- 2021
28. Bioadhesives for musculoskeletal tissue regeneration
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Chang H. Lee, Jeffrey Felix, Solaiman Tarafder, and Ga Young Park
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Skin wound ,0206 medical engineering ,Biomedical Engineering ,Adhesion (medicine) ,Biocompatible Materials ,02 engineering and technology ,Regenerative Medicine ,Biochemistry ,Regenerative medicine ,Article ,Biomaterials ,Musculoskeletal tissue ,Medicine ,Molecular Biology ,Wound Healing ,Tissue Engineering ,business.industry ,Regeneration (biology) ,Soft tissue ,General Medicine ,021001 nanoscience & nanotechnology ,medicine.disease ,Tissue Graft ,020601 biomedical engineering ,Tissue Adhesives ,Musculoskeletal regeneration ,0210 nano-technology ,business ,Biotechnology ,Biomedical engineering - Abstract
Natural or synthetic materials designed to adhere to biological components, bioadhesives, have received significant attention in clinics and surgeries. As a result, there are several commercially available, FDA-approved bioadhesives used for skin wound closure, hemostasis, and sealing tissue gaps or cracks in soft tissues. Recently, the application of bioadhesives has been expanded to various areas including musculoskeletal tissue engineering and regenerative medicine. The instant establishment of a strong adhesion force on tissue surfaces has shown potential to augment repair of connective tissues. Bioadhesives have also been applied to secure tissue grafts to host bodies and to fill or seal gaps in musculoskeletal tissues caused by injuries or degenerative diseases. In addition, the injectability equipped with the instant adhesion formation may provide the great potential of bioadhesives as vehicles for localized delivery of cells, growth factors, and small molecules to facilitate tissue healing and regeneration. This review covers recent research progress in bioadhesives as focused on their applications in musculoskeletal tissue repair and regeneration. We also discuss the advantages and outstanding challenges of bioadhesives, as well as the future perspective toward regeneration of connective tissues with high mechanical demand.
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- 2020
29. The use of connective tissue growth factor mimics for flexor tendon repair
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Hua Shen, Solaiman Tarafder, Gayoung Park, Jichuan Qiu, Younan Xia, Chang H. Lee, Richard H. Gelberman, and Stavros Thomopoulos
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Tendons ,Dogs ,Sutures ,Connective Tissue Growth Factor ,Animals ,Orthopedics and Sports Medicine ,Cell Differentiation - Abstract
Intrasynovial flexor tendon lacerations of the hand are clinically problematic, typically requiring operative repair and extensive rehabilitation. The small-molecule connective tissue growth factor (CTGF) mimics, oxotremorine M (Oxo-M) and 4-PPBP maleate (4-PPBP), have been shown to improve tendon healing in small animal models by stimulating the expansion and differentiation of perivascular CD146+ cells. To enhance intrasynovial flexor tendon healing, small-molecule CTGF mimics were delivered to repaired canine flexor tendons via porous sutures. In vitro studies demonstrated that Oxo-M and 4-PPBP retained their bioactivity and could be released from porous sutures in a sustained manner. However, in vivo delivery of the CTGF mimics did not improve intrasynovial tendon healing. Histologic analyses and expression of tenogenic, extracellular matrix, inflammation, and remodeling genes showed similar outcomes in treated and untreated repairs across two time points. Although in vitro experiments revealed that CTGF mimics stimulated robust responses in extrasynovial tendon cells, there was no response in intrasynovial tendon cells, explaining the lack of in vivo effects. The results of the current study indicate that therapeutic strategies for tendon repair must carefully consider the environment and cellular makeup of the particular tendon for improving the healing response.
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- 2022
30. Differential Risk of Cancer Associated with Glucagon-like Peptide-1 Receptor Agonists: Analysis of Real-world Databases
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Jiasheng Wang and Chang H Kim
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Male ,endocrine system diseases ,Colorectal cancer ,business.industry ,nutritional and metabolic diseases ,Type 2 Diabetes Mellitus ,Cancer ,General Medicine ,medicine.disease ,Glucagon-like peptide-1 ,Glucagon-Like Peptide-1 Receptor ,Metformin ,Prostate cancer ,Endocrinology ,Diabetes Mellitus, Type 2 ,Neoplasms ,Cancer research ,medicine ,Humans ,Hypoglycemic Agents ,Lung cancer ,business ,Receptor ,Thyroid cancer - Abstract
Glucagon-like peptide 1 receptor agonists (GLP1Ra) are commonly used in type 2 diabetes mellitus (T2DM). However, differential risk of various cancers among GLP1Ra recipients is unknown. We inquired an aggregated electronic health record database, Explorys, and compared the adjusted odds ratio (aOR) of cancers between GLP1Ra and metformin users. Findings were validated in the FDA Adverse Event Reporting System (FDA FAERS). From 1/2005 to 6/2019, we identified 619 340 and 64 230 patients in the metformin and GLP1Ra group, respectively. Within 5 years of starting antidiabetic medications, GLP1Ra was associated with significantly lower incident risk of prostate (aOR 0.81, p = .03), lung (aOR 0.81, p = .05), and colon cancer (aOR 0.85, p = .03), while the risk of thyroid cancer was significantly higher (aOR 1.65, p p = .08), lung (aOR 0.52, p p = .31), and higher risk of thyroid cancer (aOR 4.33, p GLP1Ra is associated with lower risks of prostate, lung, and colon cancer, but higher risk of thyroid cancer.
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- 2022
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31. 90Y-Daclizumab (Anti-CD25), High-Dose Carmustine, Etoposide, Cytarabine, and Melphalan Chemotherapy and Autologous Hematopoietic Stem Cell Transplant Yielded Sustained Complete Remissions in 4 Patients with Recurrent Hodgkin's Lymphoma
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Claude Sportes, Martin W. Brechbiel, Millie Whatley, Thomas A. Fleisher, Erin M Corcoran, Jae-Ho Lee, Thomas A. Waldmann, Daniel H. Fowler, Bonita R. Bryant, Kevin C. Conlon, Ronald E. Gress, Jorge A. Carrasquillo, Clara C. Chen, Chang H. Paik, Karen A. Kurdziel, Milos D. Miljkovic, and Stefania Pittaluga
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0301 basic medicine ,Oncology ,Melphalan ,Cancer Research ,medicine.medical_specialty ,medicine.medical_treatment ,03 medical and health sciences ,0302 clinical medicine ,Daclizumab ,immune system diseases ,hemic and lymphatic diseases ,Internal medicine ,medicine ,Radiology, Nuclear Medicine and imaging ,Pharmacology ,Chemotherapy ,business.industry ,Hematopoietic stem cell ,Original Articles ,General Medicine ,Hodgkin's lymphoma ,medicine.disease ,Lymphoma ,030104 developmental biology ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Radioimmunotherapy ,Cytarabine ,business ,medicine.drug - Abstract
Background: Despite advances in therapy of Hodgkin's lymphoma (HL), a proportion of patients will not respond or relapse. The authors had previously identified CD25, IL-2Rα, as a target for systemic radioimmunotherapy of HL since most normal cells do not express CD25, but it is expressed by a minority of Hodgkin/Reed-Sternberg (HRS) cells and most Tregs rosetting around HRS cells. Study Design and Treatment: This was a single institution, nonrandomized, open-label phase I/II trial of radiolabeled (90)Y-daclizumab, an anti-CD25 monoclonal antibody, BEAM (carmustine, etoposide, cytarabine, and melphalan) conditioning treatment followed by autologous hematopoietic stem cell transplant (ASCT). Four patients with refractory and relapsed HL were treated in this trial with 3 patients receiving a single dose of 564.6–574.6 MBq (90)Y-daclizumab and the fourth patient receiving two doses of 580.9–566.1 MBq (90)Y-daclizumab followed by high-dose chemotherapy and ASCT. Results: All 4 evaluable patients treated with (90)Y-daclizumab obtained complete responses (CRs) that are ongoing 4.5–7 years following their stem cell transplant. The spectrum and severity of adverse events were mild and more importantly none of the patients, including several with multiple therapies before this treatment, developed the myelodysplastic syndrome. Discussion: Targeting by daclizumab was not directed primarily at tumor cells, but rather the nonmalignant CD25-expressing T cells adjacent to the HRS cells and (90)Y-daclizumab provided strong enough β emissions to kill CD25-negative tumor cells at a distance by a crossfire effect. Furthermore, the strong β irradiation killed normal cells in the tumor microenvironment. Conclusions: (90)Y-daclizumab (anti-CD25), high-dose BEAM chemotherapy and ASCT was well tolerated and yielded sustained complete remissions in all 4 patients with recurrent HL patients who completed their treatment. Significance: Despite advances, a proportion of patients with HL will not have a CR to their initial treatment, and some with CRs will relapse. They demonstrated that the addition of (90)Y-daclizumab into the preconditioning regimen for refractory and relapsed HL patients with high-dose BEAM chemotherapy and ASCT provided sustained CRs in the 4 patients studied. Two of these patients were highly refractory to multiple prior treatments with bulky disease at entry into this study, including 1 patient who never entered a remission and had failed 6 different therapeutic regimens. Despite the small number of patients treated in this study, the sustained clinical benefit in these patients indicates a highly effective treatment. The daclizumab was directed primarily not at HRS cells themselves but toward nonmalignant T cells rosetting around malignant cells. (90)Y provided strong β emissions that killed antigen nonexpressing tumor cells at a distance by a crossfire effect. Furthermore, the strong β radiation killed normal cells in the tumor microenvironment that nurtured the malignant cells in the lymphomatous mass. The present study supports expanded analysis of (90)Y-daclizumab as part of the regimen of ASCT in patients with refractory and relapsed HL.
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- 2020
32. Discovery of N-Ethyl-4-[2-(4-fluoro-2,6-dimethyl-phenoxy)-5-(1-hydroxy-1-methyl-ethyl)phenyl]-6-methyl-7-oxo-1H-pyrrolo[2,3-c]pyridine-2-carboxamide (ABBV-744), a BET Bromodomain Inhibitor with Selectivity for the Second Bromodomain
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Daniel H. Albert, Wei Qiu, Chang H. Park, Steven D. Fidanze, Lisa A. Hasvold, Maricel Torrent, Ganesh Rajaraman, Xiaoli Huang, Peter Kovar, Keith F. McDaniel, Xiaoyu Lin, George S. Sheppard, Le Wang, John K. Pratt, Lu Zhang, Mai Bui, Yu Shen, Kenton L. Longenecker, Warren M. Kati, Dachun Liu, Denise Wilcox, Terrance J. Magoc, and Emily J. Faivre
- Subjects
0303 health sciences ,BRD4 ,medicine.drug_class ,Stereochemistry ,chemical and pharmacologic phenomena ,hemic and immune systems ,Carboxamide ,01 natural sciences ,0104 chemical sciences ,Bromodomain ,010404 medicinal & biomolecular chemistry ,03 medical and health sciences ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,Pyridine ,medicine ,Molecular Medicine ,Selectivity ,030304 developmental biology - Abstract
The BET family of proteins consists of BRD2, BRD3, BRD4, and BRDt. Each protein contains two distinct bromodomains (BD1 and BD2). BET family bromodomain inhibitors under clinical development for on...
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- 2020
33. High-Strength Fiber-Reinforced Composite Hydrogel Scaffolds as Biosynthetic Tendon Graft Material
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Oliver Friedrich, Colin R. Dunstan, Yogambha Ramaswamy, Solaiman Tarafder, Barbara Reischl, Hala Zreiqat, Young Jung No, and Chang H. Lee
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musculoskeletal diseases ,food.ingredient ,0206 medical engineering ,Biomedical Engineering ,02 engineering and technology ,Fiber-reinforced composite ,Gelatin ,Polyvinyl alcohol ,Biomaterials ,Mice ,chemistry.chemical_compound ,food ,In vivo ,Tensile Strength ,Ultimate tensile strength ,medicine ,Animals ,Tendon graft ,Tissue Engineering ,Tissue Scaffolds ,Chemistry ,Stem Cells ,Hydrogels ,musculoskeletal system ,021001 nanoscience & nanotechnology ,020601 biomedical engineering ,Rats ,Tendon ,medicine.anatomical_structure ,0210 nano-technology ,C2C12 ,Biomedical engineering - Abstract
The development of suitable synthetic scaffolds for use as human tendon grafts to repair tendon ruptures remains a significant engineering challenge. Previous synthetic tendon grafts have demonstrated suboptimal tissue ingrowth and synovitis due to wear particles from fiber-to-fiber abrasion. In this study, we present a novel fiber-reinforced hydrogel (FRH) that mimics the hierarchical structure of the native human tendon for synthetic tendon graft material. Ultrahigh molecular weight polyethylene (UHMWPE) fibers were impregnated with either biosynthetic polyvinyl alcohol/gelatin hydrogel (FRH-PG) or with polyvinyl alcohol/gelatin + strontium-hardystonite (Sr-Ca2ZnSi2O7, Sr-HT) composite hydrogel (FRH-PGS). The scaffolds were fabricated and assessed to evaluate their suitability for tendon graft applications. The microstructure of both FRH-PG and FRH-PGS showed successful impregnation of the hydrogel component, and the tendon scaffolds exhibited equilibrium water content of ∼70 wt %, similar to the values reported for native human tendon, compared to ∼50 wt % water content retained in unmodified UHMWPE fibers. The tensile strength of FRH-PG and FRH-PGS (77.0-81.8 MPa) matched the range of human Achilles' tendon tensile strengths reported in the literature. In vitro culture of rat tendon stem cells showed cell and tissue infiltration into both FRH-PG and FRH-PGS after 2 weeks, and the presence of Sr-HT ceramic particles influenced the expression of tenogenic markers. On the other hand, FRH-PG supported the proliferation of murine C2C12 myoblasts, whereas FRH-PGS seemingly did not support it under static culture conditions. In vivo implantation of FRH-PG and FRH-PGS scaffolds into full-thickness rat patellar tendon defects showed good collagenous tissue ingrowth into these scaffolds after 6 weeks. This study demonstrates the potential viability for our FRH-PG and FRH-PGS scaffolds to be used for off-the-shelf biosynthetic tendon graft material.
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- 2020
34. Selective inhibition of the BD2 bromodomain of BET proteins in prostate cancer
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Denise Wilcox, Vasudha Sehgal, Daniel H. Albert, John K. Pratt, Keith F. McDaniel, Xin Lu, Chaohong Sun, Dachun Liu, Joshua P. Plotnik, Srinivasa R. Mantena, Emily J. Faivre, Lisa A. Hasvold, George S. Sheppard, Xiaoli Huang, Le Wang, Lance J Bigelow, Stacey Fossey, Steve D. Fidanze, Lloyd T. Lam, Chang H. Park, Sanjay C. Panchal, Warren M. Kati, John J. Nicolette, Richard J. Bellin, Gaurav Mehta, Xiaoyu Lin, Mai H. Bui, Lu Zhang, Paul Hessler, Maricel Torrent, Tamar Uziel, Saul H. Rosenberg, Yu Shen, and Kenton L. Longenecker
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Male ,BRD4 ,Transcription, Genetic ,Pyridines ,Cell Cycle Proteins ,BET inhibitor ,Mice ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Protein Domains ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Gene silencing ,Pyrroles ,Receptor ,Cell Proliferation ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,biology ,Chemistry ,Prostatic Neoplasms ,medicine.disease ,Xenograft Model Antitumor Assays ,Rats ,Bromodomain ,Gene Expression Regulation, Neoplastic ,Enhancer Elements, Genetic ,Histone ,Receptors, Androgen ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,Chromatin immunoprecipitation ,Transcription Factors - Abstract
Proteins of the bromodomain and extra-terminal (BET) domain family are epigenetic readers that bind acetylated histones through their bromodomains to regulate gene transcription. Dual-bromodomain BET inhibitors (DbBi) that bind with similar affinities to the first (BD1) and second (BD2) bromodomains of BRD2, BRD3, BRD4 and BRDt have displayed modest clinical activity in monotherapy cancer trials. A reduced number of thrombocytes in the blood (thrombocytopenia) as well as symptoms of gastrointestinal toxicity are dose-limiting adverse events for some types of DbBi1–5. Given that similar haematological and gastrointestinal defects were observed after genetic silencing of Brd4 in mice6, the platelet and gastrointestinal toxicities may represent on-target activities associated with BET inhibition. The two individual bromodomains in BET family proteins may have distinct functions7–9 and different cellular phenotypes after pharmacological inhibition of one or both bromodomains have been reported10,11, suggesting that selectively targeting one of the bromodomains may result in a different efficacy and tolerability profile compared with DbBi. Available compounds that are selective to individual domains lack sufficient potency and the pharmacokinetics properties that are required for in vivo efficacy and tolerability assessment10–13. Here we carried out a medicinal chemistry campaign that led to the discovery of ABBV-744, a highly potent and selective inhibitor of the BD2 domain of BET family proteins with drug-like properties. In contrast to the broad range of cell growth inhibition induced by DbBi, the antiproliferative activity of ABBV-744 was largely, but not exclusively, restricted to cell lines of acute myeloid leukaemia and prostate cancer that expressed the full-length androgen receptor (AR). ABBV-744 retained robust activity in prostate cancer xenografts, and showed fewer platelet and gastrointestinal toxicities than the DbBi ABBV-07514. Analyses of RNA expression and chromatin immunoprecipitation followed by sequencing revealed that ABBV-744 displaced BRD4 from AR-containing super-enhancers and inhibited AR-dependent transcription, with less impact on global transcription compared with ABBV-075. These results underscore the potential value of selectively targeting the BD2 domain of BET family proteins for cancer therapy. ABBV-744, a selective inhibitor of the BD2 domains of BET family proteins, is effective against prostate cancer in mouse xenograft models, with lower toxicities than the dual-bromodomain BET inhibitor ABBV-075.
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- 2020
35. Urea Injection Control Based on Deep-Q Networks for SCR Aftertreatment Systems
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Byungjun Lee, Chang H. Kim, Shin Young Bae, Jung Changho, Lim Sanha, Dong Hwi Jeong, Jong Min Lee, Yeonsoo Kim, and Yong Wha Kim
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inorganic chemicals ,0209 industrial biotechnology ,020208 electrical & electronic engineering ,Selective catalytic reduction ,02 engineering and technology ,Vehicle driving ,Automotive engineering ,chemistry.chemical_compound ,Diesel fuel ,Model predictive control ,020901 industrial engineering & automation ,chemistry ,Control and Systems Engineering ,cardiovascular system ,0202 electrical engineering, electronic engineering, information engineering ,Urea ,Environmental science ,Engine control unit ,NOx ,Control methods - Abstract
The regulations on NOx emissions from diesel vehicles have been stringent in recent years. Various techniques such as lean NOx trap (LNT) and selective catalytic reduction (SCR) have been developed to lessen the NOx emissions. The urea-based SCR method, which utilizes NH3 as reducing agent to remove NOx, is widely used. Determining optimal amount of injected urea that keeps NOx at outlet below regulated NOx emission and also minimizes the amount of dosed urea is important. Model predictive control (MPC) is popularly used to determine the optimal amount of injected urea. However, applying MPC to real vehicle driving may be difficult because the on-line computation of MPC is too costly to be conducted in the engine control unit (ECU), the computation performance of which is significantly low at present. Therefore, reinforcement learning (RL) is considered as an alternative to on-line control method. In this paper, deep Q-networks (DQN), which is an off-policy RL with discrete action space and suitable to solve high dimensional problem, is applied to determine the amount of urea injection in the SCR system. The simulation of urea injection control with DQN has been conducted with respect to inlet NOx emissions of real driving data.
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- 2020
36. Oxygen Behavior in High Temperature Plasma and its Applications to Hydrocarbon Fuels
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Han S. Uhm, Joo Young Lee, Sang G. Woo, Chang H. Choi, and Dong J. Kim
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inorganic chemicals ,010302 applied physics ,chemistry.chemical_classification ,Materials science ,Hydrogen ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen ,Methane ,Dissociation (chemistry) ,chemistry.chemical_compound ,Hydrocarbon ,chemistry ,0103 physical sciences ,Molecule ,0210 nano-technology ,Carbon monoxide ,Syngas - Abstract
Oxygen molecules breakdown to atoms by impact dissociation of electrons in a microwave oxygen torch. Typical atom density of oxygen in a microwave torch is a few times of 1018/cm3 produced within millisecond time scale. Dwelling time of an oxygen fluid element in a discharge tube is longer than 10 milliseconds, which is much longer than the atom production time. The oxidation coefficient of hydrocarbon fuel in oxygen atoms is usually about one million times faster than that in oxygen molecules. As an example of applications, oxygen atoms are applied to dimethyl ether, which is relatively a large molecular structure. The initial breakdown species of DME molecules in a high-temperature reaction chamber are hydrogen, carbon monoxide and methane, which is also breakdown to CO and H2 by oxygen atoms. Abundance of water may be generated in a reaction chamber of relatively low-temperature lower than Tg = 1500K, hindering an efficient production of synthetic gas. DME disintegration in a hot chamber by a microwave oxygen torch is experimentally observed. Experimental observation is somewhat agreeing with theoretical predictions.
- Published
- 2019
37. Complex Language, Negative Emotion, and Entertainment: Psychological Linguistic Elements of Mobile Comments on News Stories
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Chang H. Lee and Jeongsub Lim
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Entertainment ,General Medicine ,Psychology ,Negative emotion ,Linguistics - Published
- 2019
38. A convolutional neural network highlights mutations relevant to antimicrobial resistance in Mycobacterium tuberculosis
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Anna G. Green, Chang H. Yoon, Michael L. Chen, Luca Freschi, Matthias I. Gröschel, Isaac Kohane, Andrew Beam, and Maha Farhat
- Abstract
Long diagnostic wait times hinder international efforts to address multi-drug resistance in M. tuberculosis. Pathogen whole genome sequencing, coupled with statistical and machine learning models, offers a promising solution. However, generalizability and clinical adoption have been limited in part by a lack of interpretability and verifiability, especially in deep learning methods. Here, we present a deep convolutional neural network (CNN) that predicts the antibiotic resistance phenotypes of M. tuberculosis isolates. The CNN performs with state-of-the-art levels of predictive accuracy. Evaluation of salient sequence features permits biologically meaningful interpretation and validation of the CNN’s predictions, with promising repercussions for functional variant discovery, clinical applicability, and translation to phenotype prediction in other organisms.
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- 2021
39. Quantum dots-labeled polymeric scaffolds for
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Kun Hee, Sim, Seyed Mohammand, Mir, Sophia, Jelke, Solaiman, Tarafder, Jinho, Kim, and Chang H, Lee
- Abstract
The inevitable gap between
- Published
- 2021
40. Abstract B18: Breast cancer cryoablation in combination with anti-CTLA-4 increases T cell activation in a murine tumor model
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Flavia Sardela de Miranda, Rachel Babcock, Maribel Castro, Sonia Y Khan, Carsen Roach, Thomas Hintelmann, Kathryn Furr, Chang H Lee, Geetha P Boligala, Fahmida Rasha, Luis Brandi, Harvinder S Gill, Kevin Pruitt, and Rakhshanda L Rahman
- Subjects
Cancer Research ,Immunology - Abstract
Introduction: Triple-negative and HER2+ breast cancers (BCs) are high-risk subtypes that spread easily and are hard to treat. Thus, newer therapeutic approaches that can prevent local recurrence and metastatic spread of disease are required. Cryoablation, a technique that kills tumor cells through rapid freeze/thaw cycles, preserving tumor-associated antigens, is approved to treat small low-risk breast tumors but has not been as successful for high-risk BCs. A promising area of BC cryoablation research is its combinational use with immune checkpoint inhibitors (ICIs) to enhance the anti-tumor immune response and to generate distant tumor cell targeting – the abscopal effect. Using a murine model of high-risk metastatic BC, we investigated cryoablation in conjunction with anti-CTLA4 and anti-PD-L1.Methods: BALB/c mice were bilaterally transplanted in the mammary fat pad with 4T1-12b-luciferase-expressing metastatic BC cells. Two weeks after transplant, all mice had their left tumors cryoablated; 24 hours pre- and post-cryoablation, mice received an intraperitoneal injection containing PBS (control, n=5) or 100 µg of either anti-CTLA4 (n=5) or anti-PD-L1 (n=5). Right tumors were not manipulated and represented distant metastatic tumors to examine the immune abscopal effect. Mice were sacrificed one-week post-cryoablation; cryoablated (left) and abscopal (right) tumors, peripheral blood and spleen were collected and processed to obtain isolated cells for flow cytometry analysis of immune cell populations.Results: In vivo fluorescence imaging and mouse necropsies revealed cryoablated tumors undergoing necrosis. A trend of reduced tumor weights was observed in abscopal tumors of ICI-treated groups. Flow cytometry analysis showed that the frequency of total T cells was similar across all groups in both the cryoablated and abscopal tumors, spleens, and blood. However, when examining different activation states of T cell subsets, we found anti-CTLA4 treated mice had increased T cell activity with higher percent of effector and effector memory CD4+ T cells in the abscopal tumors compared to the non-treated group, where similar trends were observed for the CD8+ T cells. Additionally, a higher percent of activated, effector, and effector memory CD4+ and CD8+ T cells were found in the blood of mice treated with anti-CTLA4, compared to the non-treated mice. Interestingly, we did not observe broad T cell activation with anti-PD-L1 treatment but found increased levels of naïve CD8+ T cells in abscopal tumors compared to the other groups.Conclusions: Cryoablation in combination with anti-CTLA4 increased T cell activation in abscopal tumors and blood after treatment, while the combination with anti-PD-L1 increased naïve CD8+ T cells. The observed differences are in accordance with the distinct mechanism of action for each drug. Further studies will investigate each strategy in long-term survival experiments. The goal is to identify and develop predictive biomarkers for efficacy of cryoablation in combination with ICIs that can be translated to the clinic. Citation Format: Flavia Sardela de Miranda, Rachel Babcock, Maribel Castro, Sonia Y Khan, Carsen Roach, Thomas Hintelmann, Kathryn Furr, Chang H Lee, Geetha P Boligala, Fahmida Rasha, Luis Brandi, Harvinder S Gill, Kevin Pruitt, Rakhshanda L Rahman. Breast cancer cryoablation in combination with anti-CTLA-4 increases T cell activation in a murine tumor model [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy; 2022 Oct 21-24; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(12 Suppl):Abstract nr B18.
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- 2022
41. Membrane Applications in Autologous Cell Therapy
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Martin, R, Lei, R, Zeng, Y, Zhu, J, Chang, H, Ye, H, and Cui, Z
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Process Chemistry and Technology ,Chemical Engineering (miscellaneous) ,Filtration and Separation - Abstract
Stem cell and cell therapies, particularly autologous cell therapies, are becoming a common practice. However, in order for these technologies to achieve wide-scale clinical application, the prohibitively high cost associated with these therapies must be addressed through creative engineering. Membranes can be a disruptive technology to reshape the bioprocessing and manufacture of cellular products and significantly reduce the cost of autologous cell therapies. Examples of successful membrane applications include expansions of CAR-T cells, various human stem cells, and production of extracellular vesicles (EVs) using hollow fibre membrane bioreactors. Novel membranes with tailored functions and surface properties and novel membrane modules that can accommodate the changing needs for surface area and transport properties are to be developed to fulfil this key role.
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- 2022
42. Machine Learning to Predict 10-year Cardiovascular Mortality from the Electrocardiogram: Analysis of the Third National Health and Nutrition Examination Survey (NHANES III)
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Chang H. Kim, Riddhi Vyas, Shankar Srinivasan, Suril Gohel, Yasir Tarabichi, and Sadeer G. Al-Kindi
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Artificial neural network ,National Health and Nutrition Examination Survey ,Receiver operating characteristic ,business.industry ,Logistic regression ,Machine learning ,computer.software_genre ,NHANES III ,Cohort ,Ambulatory ,Medicine ,Artificial intelligence ,business ,computer ,Cardiovascular mortality - Abstract
BackgroundThe value of the electrocardiogram (ECG) for predicting long-term cardiovascular outcomes is not well defined. Machine learning methods are well suited for analysis of highly correlated data such as that from the ECG.MethodsUsing demographic, clinical, and 12-lead ECG data from the Third National Health and Nutrition Examination Survey (NHANES III), machine learning models were trained to predict 10-year cardiovascular mortality in ambulatory U.S. adults. Predictive performance of each model was assessed using area under receiver operating characteristic curve (AUROC), area under precision-recall curve (AUPRC), sensitivity, and specificity. These were compared to the 2013 American College of Cardiology/American Heart Association Pooled Cohort Equations (PCE).Results7,067 study participants (mean age: 59.2 ± 13.4 years, female: 52.5%, white: 73.9%, black: 23.3%) were included. At 10 years of follow up, 338 (4.8%) had died from cardiac causes. Compared to the PCE (AUROC: 0.668, AUPRC: 0.125, sensitivity: 0.492, specificity: 0.859), machine learning models only required demographic and ECG data to achieve comparable performance: logistic regression (AUROC: 0.754, AUPRC: 0.141, sensitivity: 0.747, specificity: 0.759), neural network (AUROC: 0.764, AUPRC: 0.149, sensitivity: 0.722, specificity: 0.787), and ensemble model (AUROC: 0.695, AUPRC: 0.166, sensitivity: 0.468, specificity: 0.912). Additional clinical data did not improve the predictive performance of machine learning models. In variable importance analysis, important ECG features clustered in inferior and lateral leads.ConclusionsMachine learning can be applied to demographic and ECG data to predict 10-year cardiovascular mortality in ambulatory adults, with potentially important implications for primary prevention.
- Published
- 2021
43. Oxo-M and 4-PPBP Delivery
- Author
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Ga Young, Park, Solaiman, Tarafder, Samantha Lewis, Eyen, Soomin, Park, Ryunhyung, Kim, Zain, Siddiqui, Vivek, Kumar, and Chang H, Lee
- Abstract
We have recently identified novel small molecules, Oxo-M and 4-PPBP, which specifically stimulate endogenous tendon stem/progenitor cells (TSCs), leading to potential regenerative healing of fully transected tendons. Here, we investigated an injectable, multidomain peptide (MDP) hydrogel providing controlled delivery of the small molecules for regenerative tendon healing. We investigated the release kinetics of Oxo-M and 4-PPBP from MDP hydrogels and the effect of MDP-released small molecules on tenogenic differentiation of TSCs and
- Published
- 2021
44. Digital Servitisation and Reverse Logistics Towards a New Circular Economy
- Author
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Adrian T. H. Kuah and Chang H. Kim
- Published
- 2021
45. Regulation of common neurological disorders by gut microbial metabolites
- Author
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Chang H Kim and Jeongho Park
- Subjects
Autoimmune diseases ,Clinical Biochemistry ,Disease ,Review Article ,Biology ,Biochemistry ,Pathogenesis ,Immune system ,Brain-Gut Axis ,medicine ,Synapse formation ,Animals ,Humans ,Microbiome ,Molecular Biology ,Host Microbial Interactions ,Multiple sclerosis ,Neurodegenerative Diseases ,Chronic inflammation ,medicine.disease ,Gastrointestinal Microbiome ,Molecular network ,Immunology ,Neuroinflammatory Diseases ,Molecular Medicine ,Disease Susceptibility ,Nervous System Diseases ,Energy Metabolism ,Dysbiosis - Abstract
The gut is connected to the CNS by immunological mediators, lymphocytes, neurotransmitters, microbes and microbial metabolites. A mounting body of evidence indicates that the microbiome exerts significant effects on immune cells and CNS cells. These effects frequently result in the suppression or exacerbation of inflammatory responses, the latter of which can lead to severe tissue damage, altered synapse formation and disrupted maintenance of the CNS. Herein, we review recent progress in research on the microbial regulation of CNS diseases with a focus on major gut microbial metabolites, such as short-chain fatty acids, tryptophan metabolites, and secondary bile acids. Pathological changes in the CNS are associated with dysbiosis and altered levels of microbial metabolites, which can further exacerbate various neurological disorders. The cellular and molecular mechanisms by which these gut microbial metabolites regulate inflammatory diseases in the CNS are discussed. We highlight the similarities and differences in the impact on four major CNS diseases, i.e., multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, and autism spectrum disorder, to identify common cellular and molecular networks governing the regulation of cellular constituents and pathogenesis in the CNS by microbial metabolites., Neurological disorders: bugs that benefit the brain Disturbances of the microbial ecosystem in our gut create physiological disturbances that can accelerate the onset of neurological disease. The intestinal microbiome generates a diverse array of metabolites that can boost metabolic health, immune function, and other essential biological processes in the human host. Jeongho Park of Kangwon National University, Chuncheon, South Korea, and Chang Kim at the University of Michigan, Ann Arbor, USA, have reviewed research into how disruption of the healthy microbiome may contribute to Alzheimer’s, Parkinson’s, multiple sclerosis, and autism spectrum disorders. These studies indicate that such a “dysbiotic” state is generally associated with increased levels of inflammation. These disturbances are not sufficient to trigger neurological disorders on their own, but the resulting inflammatory state can act in concert with other biological risk factors to accelerate disease pathology.
- Published
- 2021
46. ANDY’S STORY: HYBRID CARDIAC REHABILITATION USING A DIGITAL HEALTH PLATFORM
- Author
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Zane MacFarlane, Yumin Gao, Nino Isakadze, Erin Spaulding, Trent Johnson, Chang H. Kim, Lena Mathews, Seth S. Martin, and Francoise Marvel
- Subjects
Biomedical Engineering ,Cardiology and Cardiovascular Medicine ,Critical Care and Intensive Care Medicine - Published
- 2022
47. Intraspinal Space-Occupying Lesions in Children: Clinical Features, Neuroimaging and Surgical Outcomes of 27 Cases
- Author
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Chang H, Hui L, Ma P, Wang F, Wang Y, Yan J, Jin Z, and Li Y
- Subjects
medicine.medical_specialty ,Text mining ,Neuroimaging ,business.industry ,Medicine ,Radiology ,Space (commercial competition) ,business - Abstract
Background: Pediatric intraspinal space-occupying lesions are relatively uncommon. However, these lesions can result in neurological disabilities due to misdiagnosis and delayed treatment. The main goal of the present study is to evaluate the clinical and radiological features and treatment options of pediatric intraspinal space-occupying lesions in order to improve the clinical recognition and management. Methods: Clinical data of 27 children with intraspinal space-occupying lesions who underwent surgery treatment in a tertiary-care hospital between 2010 and 2018 were retrospectively reviewed and analyzed. Results: Of these 27 patients, 14 (51.85%) were girls and 13 (48.15%) were boys. The most common age group affected was 10~14 years (62.96%, 9 girls and 8 boys in this age group). The mean age was 10.11 years old. Pain and weakness were the most common clinical symptoms. Preoperative magnetic resonance imaging (MRI) identified intramedullary (10 cases, 37.04%), intradural extramedullary (10 cases, 37.04%) and extradural (7 cases, 25.92%) lesions, respectively. The majority of the lesions were intraspinal tumors (23 cases, 85.19%). The histological diagnosis of tumors included embryonic residual tumors (6 cases, 22.22%), ependymoma (5 cases, 18.52%), primitive neuroectodermal tumors (PNET) (3 cases, 11.11%), schwannomas (2 cases, 7.4%), ganglioneuroma (1 case, 3.7%), Ewing’s sarc (1 case, 3.7%), B-cell non Hodgkin lymphoma (1 case, 3.7%), Hodgkin lymphoma (1 case, 3.7%), chondrosarcoma (1 case, 3.7%), ganglioglioma (1 case, 3.7%), and glioma (1 case, 3.7%). Conclusions: The incidence of pediatric intraspinal space-occupying lesions is low, and the clinical manifestation is lack of specificity. The prognosis for children with malignant tumors is poor and surgical resection is still the primary treatment option.
- Published
- 2021
48. Impaired bidirectional communication between interneurons and oligodendrocyte precursor cells affects cognitive behavior
- Author
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Lin C, Anja Scheller, Xianshu Bai, Renping Zhao, Bernhard Bettler, Wenhui Huang, Hainz N, Fang L, Frank Kirchhoff, Na Zhao, Laura C. Caudal, Meier C, and Chang H
- Subjects
Cytokine ,nervous system ,medicine.medical_treatment ,medicine ,Biological neural network ,Oligodendrocyte progenitor ,GABAergic ,Cognition ,Biology ,TNFSF12 ,Prefrontal cortex ,Hypoactivity ,Neuroscience - Abstract
Cortical neural circuits are complex but very precise networks of balanced excitation and inhibition (E/I). Yet, the molecular and cellular mechanisms that form the E/I balance are just beginning to emerge. Here, using conditional GABAB receptor-deficient mice we identified a GABA/TNF-related cytokine (TNFSF12)-mediated bidirectional communication pathway between Parvalbumin-positive (PV+) fast spiking interneurons and oligodendrocyte precursor cells (OPCs) that determines the density and function of interneurons in the developing medial prefrontal cortex (mPFC). Interruption of the GABAergic signaling to OPCs resulted in reduced myelination and hypoactivity of interneurons, strong changes of cortical network activities and impaired cognitive behavior. In conclusion, glial transmitter receptors are pivotal elements in finetuning distinct brain functions.
- Published
- 2021
49. Periarteriolar stroma cells guide T cells from the red to the white pulp in the spleen
- Author
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Chang H. Kim and Qingyang Liu
- Subjects
0301 basic medicine ,White pulp ,Stromal cell ,Lymphocyte ,Immunology ,High endothelial venules ,Spleen ,Biology ,Marginal zone ,Cell biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Infectious Diseases ,medicine.anatomical_structure ,medicine ,Red pulp ,Immunology and Allergy ,Lymph ,030215 immunology - Abstract
While both the spleen and lymph nodes are called secondary lymphoid tissues, how lymphocytes enter these tissues are quite different from each other. This is because the architecture of the two types of organs and the mode of lymphocyte migration into these organs are quite distinct. In the spleen, T cells are passively released in the blood flow from the arterioles in the red pulp and marginal zone area. In contrast, T cells in the blood are actively captured on high endothelial venules in lymph nodes by the coordinated actions of CCR7 and several adhesion molecules. A recent finding indicates that T cells, released in the red pulp and marginal zone areas, actively find their way to the white zone by utilizing the migration track created by periarteriolar stromal cells. This finding adds one more piece to our understanding of lymphocyte migration for effective adaptive immune responses in the spleen.
- Published
- 2020
50. Control of Tissue-Resident Invariant NKT Cells by Vitamin A Metabolites and P2X7-Mediated Cell Death
- Author
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Qingyang Liu and Chang H. Kim
- Subjects
Programmed cell death ,T cell ,Immunology ,Cell ,Biology ,Article ,Mice ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Immunology and Allergy ,Vitamin A ,Receptor ,Cell Death ,Vitamin A Deficiency ,Effector ,Purinergic receptor ,Natural killer T cell ,Cell biology ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Cytokines ,Natural Killer T-Cells ,Receptors, Purinergic P2X7 ,Homeostasis ,030215 immunology - Abstract
Invariant NKT (iNKT) cells provide rapid innate T cell responses to glycolipid Ags from host cells and microbes. The numbers of CD1d-restricted iNKT cells are tightly controlled in mucosal tissues, but the mechanisms have been largely unclear. We found that vitamin A is a dominant factor that controls the population size of mucosal iNKT cells in mice. This negative regulation is mediated by the induction of the purinergic receptor P2X7 on iNKT cells. The expression of P2X7 is particularly high on intestinal iNKT cells, making iNKT cells highly susceptible to P2X7-mediated cell death. In vitamin A deficiency, iNKT cells fail to express P2X7 and are, therefore, resistant to P2X7-mediated cell death, leading to iNKT cell overpopulation. This phenomenon is most prominent in the intestine. We found that iNKT cells are divided into CD69+ sphingosine-1-phosphate receptor 1 (S1P1)− tissue resident and CD69− S1P1+ nonresident iNKT cells. The CD69+ S1P1− tissue-resident iNKT cells highly express P2X7 and are effectively controlled by the P2X7 pathway. The regulation of iNKT cells by vitamin A by the P2X7 pathway is important to prevent aberrant expansion of effector cytokine-producing iNKT cells. Our findings identify a novel role of vitamin A in regulating iNKT cell homeostasis in many tissues throughout the body.
- Published
- 2019
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