473 results on '"Cho KW"'
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2. Evaluation of chest compression depth during nine minutes of hands-only cardiopulmonary resuscitation performed by a lone rescuer and its effect by age group: A pilot simulation study using a manikin
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Hong, CK, Park, SO, Choi, CS, Lee, YH, Sung, AJ, Lee, JH, Cho, KW, and Hwang, SY
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- 2013
3. Functional conservation of the Wnt signaling pathway revealed by ectopic expression of Drosophila dishevelled in Xenopus.
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Rothbächer, U, Laurent, MN, Blitz, IL, Watabe, T, Marsh, JL, and Cho, KW
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Animals ,Xenopus ,Drosophila ,RNA ,Messenger ,DNA Primers ,Polymerase Chain Reaction ,Signal Transduction ,Gene Expression Regulation ,Developmental ,Base Sequence ,Conserved Sequence ,Genes ,Insect ,Genes ,Reporter ,Molecular Sequence Data ,Biological Evolution ,RNA ,Messenger ,Gene Expression Regulation ,Developmental ,Genes ,Insect ,Reporter ,Developmental Biology ,Biological Sciences ,Medical and Health Sciences - Abstract
Wnt genes encode secreted growth factors that exhibit potent effects on both embryonic and postembryonic development in vertebrates and invertebrates. Recently, the dishevelled (dsh), shaggy/zeste-white 3, and armadillo genes have been shown to participate in Wnt (wingless; wg) signaling in Drosophila. Vertebrate genes that have sequence similarities to all of these Drosophila genes have been identified. To determine whether these structurally conserved components of insect wg signaling represent a functionally conserved Wnt signaling pathway in vertebrates, we investigated the role of Drosophila dsh in Xenopus Wnt signaling. Xenopus embryos ectopically injected with Drosophila dsh mRNA developed duplicated axes similar to those seen in embryos injected with Wnt mRNAs. The involvement of dsh function in the Wnt signaling pathway in Xenopus was demonstrated using two assays which are specifically sensitive to Wnt signaling: synergistic induction of dorsal mesoderm with bFGF and the specific induction of a Wnt-responsive reporter gene. These findings support the notion that the intracellular response to the Wnt signal has been conserved during evolution to such an extent that its components may be interchanged between distantly related species.
- Published
- 1995
4. Maternal and zygotic factors sequentially shape the tissue regionalization of chromatin landscapes in early vertebrate embryos
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Blitz Il, Cho Kw, and Kitt D. Paraiso
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animal structures ,Cellular differentiation ,fungi ,Germ layer ,Biology ,Embryonic stem cell ,Cell biology ,Chromatin ,Gastrulation ,medicine.anatomical_structure ,embryonic structures ,medicine ,Maternal to zygotic transition ,natural sciences ,Endoderm ,Enhancer - Abstract
One of the first steps in cellular differentiation of vertebrate embryos is the formation of the three germ layers. Maternal pioneer transcription factors (TFs) bind to the regulatory regions of the embryonic genome prior to zygotic genome activation and initiate germ layer specification. While the involvement of maternal TFs in establishing epigenetic marks in whole embryos was addressed previously, how early pluripotent cells acquire spatially restricted epigenetic identity in embryos remain unknown. Here, we report that the H3K4me1 enhancer mark in each germ layer becomes distinct in germ layer specific regulatory regions, forming super-enhancers (SEs), by early gastrula stage. Distinct SEs are established in these germ layers near robustly regulated germ layer identity genes, suggesting that SEs are important for the canalization of development. Establishment of these enhancers requires a sequential function of maternal and zygotic TFs. By knocking down the expression of a critical set of maternal endodermal TFs, an overwhelming majority of the endodermal H3K4me1 marks are lost. Interestingly, this disappearance of endodermal marking coincides with the appearance of ectodermal and mesodermal H3K4me1 marks in the endoderm, suggesting a transformation in the chromatin state of these nuclei towards a more ecto-mesodermal state.De novomotif analysis to identify TFs responsible for the transformation recovers a profile for endodermal maternal TFs as well as their downstream target TFs. We demonstrate the importance of coordinated activities of maternal and zygotic TFs in defining a spatially resolved dynamic process of chromatin state establishment.
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- 2021
5. Insights from the first Brazilian Symposium on Human Biometeorology
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Eduardo Krüger, Ana Carla dos Santos Gomes, Paulo Sérgio Lucio, João Paulo Assis Gobo, Anderson Spohr Nedel, Fabio Luiz Teixeira Gonçalves, Marina Piacenti-Silva, Claudia Di Napoli, and Cho Kwong Charlie Lam
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urban climatology ,heat-related mortality ,climatedriven diseases. ,Environmental sciences ,GE1-350 - Abstract
A current systematic literature review has stated several deficiencies and knowledge gaps in biometeorology research conducted in Brazil. This finding encouraged a group of local professionals in the field to foster research initiatives in topics and regions yet unexplored in the country. Motivated by that, the group organized the first Brazilian Symposium on Human Biometeorology between July 4 and 8, 2022, in Natal (RN), northeastern Brazil. This paper aims to summarize the main studies presented at the symposium and highlight a few ideas that could be pursued next in human biometeorology in future research initiatives.
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- 2023
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6. Regulation of obesity and insulin resistance by hypoxia-inducible factors
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Ban JJ, Ruthenborg RJ, Cho KW, and Kim JW
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lcsh:R5-920 ,lcsh:Medicine (General) - Abstract
Jae-Jun Ban, Robin J Ruthenborg, Kevin W Cho, Jung-whan Kim Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA Abstract: In obesity, dysregulated metabolism and aberrant expansion of adipose tissue lead to the development of tissue hypoxia that plays an important role in contributing to obesity-associated metabolic disorders. Recent studies utilizing adipocyte-specific hypoxia-inducible factor-α (HIF-α) gain- or loss-of-function animal models highlight the pivotal involvement of hypoxic responses in the pathogenesis of obesity-associated inflammation and insulin resistance. HIF-1α, a master transcription factor of oxygen homeostasis, induces inflammation and insulin resistance in obesity, whereas its isoform, HIF-2α, exerts opposing functions in these obesity-associated metabolic phenotypes. In this review, recent evidence elucidating functional implications of adipocyte HIFs in obesity and, more importantly, how these regulate obesity-associated inflammation, fibrosis, and insulin resistance will be discussed. Further, we propose that modulation of HIF-1 could be a potential novel therapeutic strategy for antidiabetic treatment. Keywords: hypoxia-inducible factor-1, inflammation, oxygen 
- Published
- 2014
7. Impact of climate change and socioeconomic factors on domestic energy consumption: The case of Hong Kong and Singapore
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Cho Kwong Charlie Lam, Qing He, Kai-lok Cheng, Ping Yu Fan, Kwok Pan Chun, Byron Choi, Daphne Ngar-yin Mah, Darren Man-wai Cheung, Kevin Lo, and Omer Yetemen
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Energy consumption ,Climate change ,Heat index ,Monsoon index ,Population change ,Relative importance analysis ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Temperature and population growth are key drivers of energy consumption. However, the relative importance of climatic and socioeconomic factors driving energy consumption at different temporal scales is not well-understood. Therefore, we developed a time-series decomposition method to attribute the relative importance of climatic (heat index and monsoon index) and socioeconomic variables to domestic energy consumption in Hong Kong from 1981–2015. The same method was used for Singapore from 2005–2015 to test the transferability of our time-series method. Population growth and GDP were the primary drivers for domestic energy consumption in Hong Kong from 1981–2015, but the heat index became the primary driver from 2005–2015 instead. The monsoon and heat indexes were the primary drivers of domestic energy consumption in Singapore from 2005–2015. Climate change will increase air temperatures by 2–5 °C for Hong Kong and Singapore by 2100. For RCP4.5 and RCP8.5 scenarios, Singapore shows a linear relationship between temperature and domestic energy consumption, whereas the relationship is non-linear in Hong Kong. Our findings highlight the importance of understanding the impact of climatic change on monsoon mechanism and heat index, which can predict future cooling demand and help achieve sustainable development goals.
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- 2022
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8. Infiltrating Foxp3+ Regulatory T cells and Histopathological Features in Canine Classical and Spermatocytic Seminomas
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Kim, JH, primary, Chon, SK, additional, Im, KS, additional, Kim, NH, additional, Cho, KW, additional, and Sur, JH, additional
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- 2012
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9. Infiltrating Foxp3+ Regulatory T cells and Histopathological Features in Canine Classical and Spermatocytic Seminomas.
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Kim, JH, Chon, SK, Im, KS, Kim, NH, Cho, KW, and Sur, JH
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T cells ,HISTOPATHOLOGY ,DOG reproduction ,SPERMATOZOA ,SEMINOMA ,HOMEOSTASIS ,CANCER invasiveness ,FORKHEAD transcription factors - Abstract
Contents In humans, regulatory T (T reg) cells are known to play a critical role in both the regulation of immune homoeostasis and the progression of cancer. However, there is little information about the identification, characterization and the function of T reg cells in canine tumours. We identified T reg cells in 28 canine seminoma samples using a Forkhead box P3 (Foxp3) antibody and investigated the relationship between T reg cell infiltration and histopathological features of classical and spermatocytic seminomas (SE and SS, respectively). The Foxp3 protein showed nuclear immunostaining in infiltrating lymphocytes, and Foxp3+ cells were diffused or focally distributed in seminoma tissues. Foxp3+ cells were frequently present in the SS histotype, in seminomas that showed no evidence of tumour cell invasion into the vessels and in seminomas showing a diffuse growth pattern with three cell types. Neither the SE/SS histotype nor the histopathological features of the tumour correlated with Foxp3+ cell counts. These results indicate that Foxp3+ T reg cells may be associated with a less malignant histological phenotype or may not play a critical role in the immune response of canine seminomas. Moreover, Foxp3+ T reg cells may be associated with SS seminoma, but further studies, involving a larger number of samples, are required to better understand whether these cells play a critical role in the immune response in canine seminomas. This is the first report to demonstrate the characteristics of T reg cell infiltration in canine seminoma. [ABSTRACT FROM AUTHOR]
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- 2013
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10. SH2B1 enhances insulin sensitivity by both stimulating the insulin receptor and inhibiting tyrosine dephosphorylation of insulin receptor substrate proteins.
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Morris DL, Cho KW, Zhou Y, Rui L, Morris, David L, Cho, Kae Won, Zhou, Yingjiang, and Rui, Liangyou
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Objective: SH2B1 is a SH2 domain-containing adaptor protein expressed in both the central nervous system and peripheral tissues. Neuronal SH2B1 controls body weight; however, the functions of peripheral SH2B1 remain unknown. Here, we studied peripheral SH2B1 regulation of insulin sensitivity and glucose metabolism.Research Design and Methods: We generated TgKO mice expressing SH2B1 in the brain but not peripheral tissues. Various metabolic parameters and insulin signaling were examined in TgKO mice fed a high-fat diet (HFD). The effect of SH2B1 on the insulin receptor catalytic activity and insulin receptor substrate (IRS)-1/IRS-2 dephosphorylation was examined using in vitro kinase assays and in vitro dephosphorylation assays, respectively. SH2B1 was coexpressed with PTP1B, and insulin receptor-mediated phosphorylation of IRS-1 was examined.Results: Deletion of peripheral SH2B1 markedly exacerbated HFD-induced hyperglycemia, hyperinsulinemia, and glucose intolerance in TgKO mice. Insulin signaling was dramatically impaired in muscle, liver, and adipose tissue in TgKO mice. Deletion of SH2B1 impaired insulin signaling in primary hepatocytes, whereas SH2B1 overexpression stimulated insulin receptor autophosphorylation and tyrosine phosphorylation of IRSs. Purified SH2B1 stimulated insulin receptor catalytic activity in vitro. The SH2 domain of SH2B1 was both required and sufficient to promote insulin receptor activation. Insulin stimulated the binding of SH2B1 to IRS-1 or IRS-2. This physical interaction inhibited tyrosine dephosphorylation of IRS-1 or IRS-2 and increased the ability of IRS proteins to activate the phosphatidylinositol 3-kinase pathway.Conclusions: SH2B1 is an endogenous insulin sensitizer. It directly binds to insulin receptors, IRS-1 and IRS-2, and enhances insulin sensitivity by promoting insulin receptor catalytic activity and by inhibiting tyrosine dephosphorylation of IRS proteins. [ABSTRACT FROM AUTHOR]- Published
- 2009
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11. The Effects of Visual Cues, Blindfolding, Synesthetic Experience, and Musical Training on Pure-Tone Frequency Discrimination
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Cho Kwan Tse and Calvin Kai-Ching Yu
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frequency difference limens ,blindfold ,visual cues ,auditory-visual synesthesia ,gliding frequencies ,perceptual limit, common resource theory ,multiple resource model ,Psychology ,BF1-990 - Abstract
How perceptual limits can be reduced has long been examined by psychologists. This study investigated whether visual cues, blindfolding, visual-auditory synesthetic experience, and musical training could facilitate a smaller frequency difference limen (FDL) in a gliding frequency discrimination test. Ninety university students, with no visual or auditory impairment, were recruited for this one-between (blindfolded/visual cues) and one-within (control/experimental session) designed study. Their FDLs were tested by an alternative forced-choice task (gliding upwards/gliding downwards/no change) and two questionnaires (Vividness of Mental Imagery Questionnaire and Projector–Associator Test) were used to assess their tendency to synesthesia. The participants provided with visual cues and with musical training showed a significantly smaller FDL; on the other hand, being blindfolded or having a synesthetic experience before could not significantly reduce the FDL. However, no pattern was found between the perception of the gliding upwards and gliding downwards frequencies. Overall, the current study suggests that the inter-sensory perception can be enhanced through the training and facilitation of visual–auditory interaction under the multiple resource model. Future studies are recommended in order to verify the effects of music practice on auditory percepts, and the different mechanisms between perceiving gliding upwards and downwards frequencies.
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- 2018
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12. Efficient Secret Key Delivery Using Heartbeats
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Cho Kwantae and Chung Byungho
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Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Recently many researchers have employed physiological signals like heartbeats as a source of the key seed used in key establishment protocols. The physiological signals make it easy to establish a secret key between implantable (or attachable) medical devices which can sense physiological signals. A key establishment protocol is a fundamental requirement to support the security of the healthcare and medical services such as diagnosis, treatment, prevention, and follow-up services. However, existing key establishment protocols demand high computational and communication costs or need long key establishment time. In this paper, we propose an efficient IPI-based key establishment protocol that requires relatively short time while keeping the strength of security close.
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- 2017
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13. The Analgesic Effects of Apitoxin and its Mechanism via JOR and Measuring Expression of mRNA in Phospholipase and TPH using RT-PCR
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Cho Kwang Ho, Lee Jae-Dong, Park Dong-Suk, and Ahn Byoung-Chou
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apitoxin ,pain ,serotonin ,TPH ,phopholipase ,prostaglandin ,RT-PCR ,Medicine ,Miscellaneous systems and treatments ,RZ409.7-999 ,Therapeutics. Pharmacology ,RM1-950 - Abstract
The purpose of this study is to prove the analgesic effects of apitoxin and its mechanism via jaw-opening reflex(JOR) and measuring expression of mRNA in Phospholipase and Tryptophan hydroxylase(TPH) using RT-PCR. The experiments were carried out on Sprague-Dawley rats(300-400g) and mastocytoma (P-185 HTR) for JOR and RT-PCR, respectively. Rats anesthetized with thiopental sodium (80mg/kg) were used in the Tooth Pulp stimulation induced JOR. The amplitude of a digastric electromyogram (dEMG) was recorded during the stimulation at an intensity of 1.5 times the threshold for JOR. Apitoxin used in this experiment was diluted with normal saline by 1:1000. Apitoxin was injected intravenously into the test group while normal saline to the control group. However, it was injected directly into the cell of mastocytoma. We referred to base sequence registered in Genbank in designing primers for RT-PCR. The results were as follows; (1)Compared with control group, analgesic effect started to show right after Sprague-Dawely rats were treated with apitoxin(71.50±8.08) and lasted for 50 minutes. (2)As a result of the experiment of RT-PCR, we witnessed significant changes in the degree of expression of phospholipase or rate-limiting enzyme in biosynthesis of prostaglandins with 10μg/㎖ apitoxin.(31.74±18.98%, P
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- 2000
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14. No effect of recumbency duration on the occurrence of post-lumbar puncture headache with a 22G cutting needle
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Kim Sung R, Chae Hyun S, Yoon Mi J, Han Jung H, Cho Kwang J, and Chung Sun J
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Supine recumbence has been widely performed to prevent post-lumbar puncture headache (PLPH). However, the optimal duration of supine recumbence is controversial. The aim of the study is to compare the occurrence of PLPH according to the duration of supine recumbence in patients with neurological disorders. Methods A non-equivalent control/experimental pre-/post-test study design was used. Seventy consecutive patients were prospectively enrolled between July 2007 and July 2008. Thirty-five patients underwent supine recumbence for four hours after lumbar puncture (Group 1) and 35 patients underwent supine recumbence for one hour (Group 2). Results The overall frequency of PLPH was 31.4%. The frequency of PLPH was not significantly different between the Group 1 (28.6%) and Group 2 (34.3%) (P = 0.607). In patients with PLPH, the median severity (P = 0.203) and median onset time of PLPH (P = 0.582) were not significantly different between the two groups. In a logistic regression analysis, the previous history of post-lumbar puncture headache was a significant risk factor for the occurrence of PLPH (OR = 11.250, 95% CI: 1.10-114.369, P = 0.041). Conclusions Our study suggests that short duration (one hour) of supine recumbence may be as efficient as long duration (four hours) of supine recumbence to prevent PLPH.
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- 2012
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15. Use of serum squamous cell carcinoma antigen for follow-up monitoring of cervical cancer patients who were treated by concurrent chemoradiotherapy
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Yoon Sang, Shin Kyung, Kim Joo-Young, Seo Sang, Park Sang-Yoon, Moon Sung, and Cho Kwan
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Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background To investigate the significance of monitoring the levels of the serum squamous cell carcinoma antigen (SCC-Ag) for the detection of recurrent disease in patients with cervical cancer treated by concurrent chemoradiotherapy. Methods The records of 112 patients with cervical cancer were reviewed. Serum SCC-Ag levels were measured at regular follow-up visits. A SCC-Ag level of 2 ng/mL was considered the upper limit of normal. Biochemical failure was defined as two consecutively increasing SCC-Ag values above normal. Recurrent disease was confirmed by histologic and radiographic studies. Results Eighteen patients (16%) developed recurrent disease. Sixteen patients had initially elevated SCC-Ag, post-treatment normalization of SCC-Ag, and tumor recurrence. The SCC-Ag difference (ΔSCC-Ag), defined as the difference between the last value after two consecutively increases above normal and the value immediately before the elevation, had good clinical performance in predicting cancer recurrence. The cutoff value of ΔSCC-Ag was 0.95 ng/mL. Conclusions SCC-Ag is a relatively good method for the detection of disease recurrence in patients with cervical cancer who were treated by concurrent chemoradiotherapy.
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- 2010
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16. The effect of external beam radiotherapy volume on locoregional control in patients with locoregionally advanced or recurrent nonanaplastic thyroid cancer
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Ryu Jun, Jung Yoo, Kim Seok, Kim Tae, Lee Eun, Park Chan, Lee You, Chung Ki-Wook, Kim Sang, Cho Kwan, and Shin Kyung
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Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Purpose We evaluated outcomes of patients treated with external beam radiotherapy (EBRT) for locoregionally advanced or recurrent nonanaplastic thyroid cancer and analyzed the effect of EBRT volume on locoregional control. Methods This study included 23 patients with locoregionally advanced or recurrent nonanaplastic thyroid cancer who were treated with EBRT. Two different EBRT target volumes were executed as follows: 1) limited field (LF, n = 11) included the primary (involved lobe) or recurrent tumor bed and the positive nodal area; 2) elective field (EF, n = 12) included the primary (involved lobe) or recurrent tumor bed and the regional nodal areas in the cervical neck and upper mediastinum. Clinical parameters, such as gender, age, histologic type, recurrence, stage, thyroglobulin level, postoperative residuum, radioiodine treatment, and EBRT volume were analyzed to identify prognostic factors associated with locoregional control. Results There were no significant differences in the clinical parameter distributions between the LF and EF groups. In the LF group, six (55%) patients developed locoregional recurrence and three (27%) developed distant metastasis. In the EF group, one (8%) patient developed locoregional recurrence and one (8%) developed a distant metastasis. There was a significant difference in locoregional control rate at 5 years in the LF and EF groups (40% vs. 89%, p = 0.041). There were no significant differences in incidences of acute and late toxicities between two groups (p >0.05). Conclusions EBRT with EF provided significantly better locoregional control than that of LF; however, further larger scaled studies are warranted.
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- 2010
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17. Corticosteroids: way upstream
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Riedemann Therese, Patchev Alexandre V, Cho Kwangwook, and Almeida Osborne FX
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Studies into the mechanisms of corticosteroid action continue to be a rich bed of research, spanning the fields of neuroscience and endocrinology through to immunology and metabolism. However, the vast literature generated, in particular with respect to corticosteroid actions in the brain, tends to be contentious, with some aspects suffering from loose definitions, poorly-defined models, and appropriate dissection kits. Here, rather than presenting a comprehensive review of the subject, we aim to present a critique of key concepts that have emerged over the years so as to stimulate new thoughts in the field by identifying apparent shortcomings. This article will draw on experience and knowledge derived from studies of the neural actions of other steroid hormones, in particular estrogens, not only because there are many parallels but also because 'learning from differences' can be a fruitful approach. The core purpose of this review is to consider the mechanisms through which corticosteroids might act rapidly to alter neural signaling.
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- 2010
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18. A novel mechanism of hippocampal LTD involving muscarinic receptor-triggered interactions between AMPARs, GRIP and liprin-α
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Dickinson Bryony A, Jo Jihoon, Seok Heon, Son Gi, Whitcomb Daniel J, Davies Ceri H, Sheng Morgan, Collingridge Graham L, and Cho Kwangwook
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Long-term depression (LTD) in the hippocampus can be induced by activation of different types of G-protein coupled receptors, in particular metabotropic glutamate receptors (mGluRs) and muscarinic acethycholine receptors (mAChRs). Since mGluRs and mAChRs activate the same G-proteins and isoforms of phospholipase C (PLC), it would be expected that these two forms of LTD utilise the same molecular mechanisms. However, we find a distinct mechanism of LTD involving GRIP and liprin-α. Results Whilst both forms of LTD require activation of tyrosine phosphatases and involve internalisation of AMPARs, they use different molecular interactions. Specifically, mAChR-LTD, but not mGluR-LTD, is blocked by peptides that inhibit the binding of GRIP to the AMPA receptor subunit GluA2 and the binding of GRIP to liprin-α. Thus, different receptors that utilise the same G-proteins can regulate AMPAR trafficking and synaptic efficacy via distinct molecular mechanisms. Conclusion Our results suggest that mAChR-LTD selectively involves interactions between GRIP and liprin-α. These data indicate a novel mechanism of synaptic plasticity in which activation of M1 receptors results in AMPAR endocytosis, via a mechanism involving interactions between GluA2, GRIP and liprin-α.
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- 2009
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19. Atypical evening cortisol profile induces visual recognition memory deficit in healthy human subjects
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Gilpin Heather, Whitcomb Daniel, and Cho Kwangwook
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Diurnal rhythm-mediated endogenous cortisol levels in humans are characterised by a peak in secretion after awakening that declines throughout the day to an evening trough. However, a significant proportion of the population exhibits an atypical cycle of diurnal cortisol due to shift work, jet-lag, aging, and mental illness. Results The present study has demonstrated a correlation between elevation of cortisol in the evening and deterioration of visual object recognition memory. However, high evening cortisol levels have no effect on spatial memory. Conclusion This study suggests that atypical evening salivary cortisol levels have an important role in the early deterioration of recognition memory. The loss of recognition memory, which is vital for everyday life, is a major symptom of the amnesic syndrome and early stages of Alzheimer's disease. Therefore, this study will promote a potential physiologic marker of early deterioration of recognition memory and a possible diagnostic strategy for Alzheimer's disease.
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- 2008
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20. Analysis of feedback loops and robustness in network evolution based on Boolean models
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Cho Kwang-Hyun and Kwon Yung-Keun
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Many biological networks such as protein-protein interaction networks, signaling networks, and metabolic networks have topological characteristics of a scale-free degree distribution. Preferential attachment has been considered as the most plausible evolutionary growth model to explain this topological property. Although various studies have been undertaken to investigate the structural characteristics of a network obtained using this growth model, its dynamical characteristics have received relatively less attention. Results In this paper, we focus on the robustness of a network that is acquired during its evolutionary process. Through simulations using Boolean network models, we found that preferential attachment increases the number of coupled feedback loops in the course of network evolution. Whereas, if networks evolve to have more coupled feedback loops rather than following preferential attachment, the resulting networks are more robust than those obtained through preferential attachment, although both of them have similar degree distributions. Conclusion The presented analysis demonstrates that coupled feedback loops may play an important role in network evolution to acquire robustness. The result also provides a hint as to why various biological networks have evolved to contain a number of coupled feedback loops.
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- 2007
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21. Investigations into the relationship between feedback loops and functional importance of a signal transduction network based on Boolean network modeling
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Cho Kwang-Hyun, Choi Sun, and Kwon Yung-Keun
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background A number of studies on biological networks have been carried out to unravel the topological characteristics that can explain the functional importance of network nodes. For instance, connectivity, clustering coefficient, and shortest path length were previously proposed for this purpose. However, there is still a pressing need to investigate another topological measure that can better describe the functional importance of network nodes. In this respect, we considered a feedback loop which is ubiquitously found in various biological networks. Results We discovered that the number of feedback loops (NuFBL) is a crucial measure for evaluating the importance of a network node and verified this through a signal transduction network in the hippocampal CA1 neuron of mice as well as through generalized biological network models represented by Boolean networks. In particular, we observed that the proteins with a larger NuFBL are more likely to be essential and to evolve slowly in the hippocampal CA1 neuronal signal transduction network. Then, from extensive simulations based on the Boolean network models, we proved that a network node with the larger NuFBL is likely to be more important as the mutations of the initial state or the update rule of such a node made the network converge to a different attractor. These results led us to infer that such a strong positive correlation between the NuFBL and the importance of a network node might be an intrinsic principle of biological networks in view of network dynamics. Conclusion The presented analysis on topological characteristics of biological networks showed that the number of feedback loops is positively correlated with the functional importance of network nodes. This result also suggests the existence of unknown feedback loops around functionally important nodes in biological networks.
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- 2007
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22. Least-squares methods for identifying biochemical regulatory networks from noisy measurements
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Heslop-Harrison Pat, Postlethwaite Ian, Bates Declan G, Kim Jongrae, and Cho Kwang-Hyun
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background We consider the problem of identifying the dynamic interactions in biochemical networks from noisy experimental data. Typically, approaches for solving this problem make use of an estimation algorithm such as the well-known linear Least-Squares (LS) estimation technique. We demonstrate that when time-series measurements are corrupted by white noise and/or drift noise, more accurate and reliable identification of network interactions can be achieved by employing an estimation algorithm known as Constrained Total Least Squares (CTLS). The Total Least Squares (TLS) technique is a generalised least squares method to solve an overdetermined set of equations whose coefficients are noisy. The CTLS is a natural extension of TLS to the case where the noise components of the coefficients are correlated, as is usually the case with time-series measurements of concentrations and expression profiles in gene networks. Results The superior performance of the CTLS method in identifying network interactions is demonstrated on three examples: a genetic network containing four genes, a network describing p53 activity and mdm2 messenger RNA interactions, and a recently proposed kinetic model for interleukin (IL)-6 and (IL)-12b messenger RNA expression as a function of ATF3 and NF-κB promoter binding. For the first example, the CTLS significantly reduces the errors in the estimation of the Jacobian for the gene network. For the second, the CTLS reduces the errors from the measurements that are corrupted by white noise and the effect of neglected kinetics. For the third, it allows the correct identification, from noisy data, of the negative regulation of (IL)-6 and (IL)-12b by ATF3. Conclusion The significant improvements in performance demonstrated by the CTLS method under the wide range of conditions tested here, including different levels and types of measurement noise and different numbers of data points, suggests that its application will enable more accurate and reliable identification and modelling of biochemical networks.
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- 2007
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23. Water extract of Zanthoxylum piperitum induces vascular relaxation via endothelium-dependent NO-cGMP signaling.
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Li X, Kim HY, Cui HZ, Cho KW, Kang DG, and Lee HS
- Abstract
AIM OF THE STUDY: The aim of the present study was to define the effects of extracts of leaves of Zanthoxylum piperitum (ZP) on the vascular tension and its mechanisms responsible in rat thoracic aortic rings. MATERIALS AND METHODS: Methanol extract of ZP and aqueous fraction of the methanol extract (AZP) were examined for their vascular relaxant effects in isolated phenylephrine-precontracted aortic rings. RESULTS: Methanol extract of ZP and aqueous fraction of the methanol extract (AZP) induced relaxation of the phenylephrine-precontracted aortic rings in a concentration-dependent manner. Endothelium-denudation abolished the AZP-induced vasorelaxation. Pretreatment of the endothelium-intact aortic rings with N(G)-nitro-L-arginine methylester (L-NAME) and 1H-[1,2,4]-oxadiazolo-[4,3-alpha]-quinoxalin-1-one (ODQ) inhibited the AZP-induced vasorelaxation. Inhibition of Ca(2+) entry via L-type Ca(2+) channels failed to block the AZP-induced vasorelaxation. Extracellular Ca(2+) depletion slightly but significantly attenuated the AZP-induced vasorelaxation. Thapsigargin significantly attenuated the AZP-induced vasorelaxation. Further, Gd(3+) and 2-aminoethyl diphenylborinate (2-APB), inhibitors of store-operated Ca(2+) entry (SOCE), markedly attenuated the AZP-induced vasorelaxation. Also, wortmannin, an inhibitor of Akt, an upstream signaling molecule of eNOS, attenuated the AZP-induced vasorelaxation. AZP increased cGMP levels of the aortic rings in a concentration-dependent manner and the effect was blocked by L-NAME, ODQ, thapsigargin, Gd(3+), 2-APB, and wortmannin. K(+) channel inhibition with glibenclamide and tetraethylammonium, cyclooxygenase inhibition with indomethacin, and adrenergic and muscarinic receptors blockade had no effects on the AZP-induced vasorelaxation. CONCLUSION: Taken together, the present study suggests that AZP relaxes vascular smooth muscle via endothelium-dependent activation of NO-cGMP signaling through the Akt- and SOCE-eNOS pathways. [ABSTRACT FROM AUTHOR]
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- 2010
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24. Aqueous extract of Zanthoxylum schinifolium elicits contractile and secretory responses via ß1-adrenoceptor activation in beating rabbit atria.
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Cui HZ, Choi HR, Choi DH, Cho KW, Kang DG, and Lee HS
- Abstract
AIM OF STUDY: Although Zanthoxylum schinifolium has long been used in the traditional oriental medicine, cardiac effects have not well been documented. The aim of the present study was to investigate the effects of aqueous extract of leaves and stems from Zanthoxylum schinifolium (AZS) on inotropic effect and atrial natriuretic peptide (ANP) secretion. MATERIALS AND METHODS: The AZS-induced changes in atrial dynamics, cAMP efflux and atrial ANP secretion were determined in isolated perfused beating rabbit atria. RESULTS: AZS increased atrial pulse pressure, stroke volume, and cAMP efflux concomitantly with inhibition of ANP secretion in a concentration-dependent manner. The AZS-induced increases in atrial dynamics and cAMP efflux, and decrease in ANP secretion were attenuated by pretreatment with propranolol and CGP 20712 but not ICI 118,551. Also, the AZS-induced changes in atrial dynamics and ANP secretion were attenuated by diltiazem and KT 5720. Diltiazem and KT 5720 had not significant effect on the AZS-induced increase in cAMP efflux. CONCLUSION: These results suggest that AZS elicits a positive inotropic effect and decrease in ANP secretion via beta(1)-adrenoceptor-cAMP-Ca(2+) signaling in beating rabbit atria. [ABSTRACT FROM AUTHOR]
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- 2009
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25. Prediction of insulin resistance and elevated liver transaminases using serum uric acid and derived markers in children and adolescents.
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Choi Y, Yang H, Jeon S, Cho KW, Kim SJ, Kim S, Lee M, Suh J, Chae HW, Kim HS, and Song K
- Subjects
- Humans, Child, Adolescent, Male, Female, Hyperuricemia blood, Logistic Models, Cross-Sectional Studies, Transaminases blood, Alanine Transaminase blood, Odds Ratio, Area Under Curve, Obesity blood, Insulin Resistance, Uric Acid blood, Biomarkers blood, Body Mass Index, Liver enzymology, ROC Curve
- Abstract
Objective: To investigate the relationship of serum uric acid (Uacid) and derived parameters as predictors of insulin resistance (IR) and elevated liver transaminases in children and adolescents METHODS: Data of 1648 participants aged 10-18 years was analyzed using nationwide survey. Logistic regression analysis was performed with IR and elevated liver transaminases as dependent variables, and odds ratios (ORs) and 95% confidence intervals (CIs) for tertiles 2 and 3 of each parameter in comparison to tertile 1, which served as the reference. Receiver operating characteristic (ROC) curves were generated to assess predictability of the parameters for IR and elevated liver transaminases., Results: Hyperuricemia, IR, and elevated liver transaminases were significantly associated with each other. All Uacid and derived markers showed continuous increase in ORs and 95% CIs for IR and elevated liver transaminases across the tertiles of several biochemical and metabolic variables of interest (all p < 0.001), and were also significantly predictive in ROC curve. Overall, Uacid combined with obesity indices showed higher ORs and area under the curve (AUC) compared to Uacid alone. Uacid-body mass index (BMI) standard deviation score presented the largest AUC for IR. For elevated liver transaminases, Uacid-BMI and Uacid-waist-to-height ratio showed the largest AUC., Conclusions: Uacid combined with obesity indices are robust markers for prediction of IR and elevated liver transaminases in children and adolescents. Uacid and derived markers have potential as simple markers which do not require fasting for screening of IR and elevated liver transaminases in children and adolescents., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
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- 2024
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26. Dynamic Roles and Expanding Diversity of Adipose Tissue Macrophages in Obesity.
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Soedono S, Julietta V, Nawaz H, and Cho KW
- Abstract
Adipose tissue macrophages (ATMs) are key regulators of adipose tissue (AT) inflammation and insulin resistance in obesity, and the traditional M1/M2 characterization of ATMs is inadequate for capturing their diversity in obese conditions. Single-cell transcriptomic profiling has revealed heterogeneity among ATMs that goes beyond the old paradigm and identified new subsets with unique functions. Furthermore, explorations of their developmental origins suggest that multiple differentiation pathways contribute to ATM variety. These advances raise concerns about how to define ATM functions, how they are regulated, and how they orchestrate changes in AT. This review provides an overview of the current understanding of ATMs and their updated categorization in both mice and humans during obesity. Additionally, diverse ATM functions and contributions in the context of obesity are discussed. Finally, potential strategies for targeting ATM functions as therapeutic interventions for obesity-induced metabolic diseases are addressed.
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- 2024
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27. Extracellular cleavage of microglia-derived progranulin promotes diet-induced obesity.
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Park CB, Lee CH, Cho KW, Shin S, Jang WH, Byeon J, Oh YR, Kim SJ, Park JW, Kang GM, Min SH, Kim S, Yu R, and Kim MS
- Abstract
Hypothalamic innate immune responses to dietary fats underpin the pathogenesis of obesity, in which microglia play a critical role. Progranulin (PGRN) is an evolutionarily -conserved secretory protein containing seven-and-a-half granulin (GRN) motifs. It is cleaved into GRNs by multiple proteases. In the central nervous system, PGRN is highly expressed in microglia. To investigate the role of microglia-derived PGRN in metabolism regulation, we established a mouse model with a microglia-specific deletion of the Grn gene, that encodes PGRN. Mice with microglia-specific Grn gene depletion displayed dietdependent metabolic phenotypes. Under normal diet-fed conditions, microglial Grn gene depletion produced adverse outcomes like fasting hyperglycemia and aberrant activation of hypothalamic microglia. However, when fed a high fat diet (HFD), these mice exhibited beneficial effects, including less obesity, glucose dysregulation, and hypothalamic inflammation. These differing phenotypes appear linked to increased extracellular cleavage of anti-inflammatory PGRN into proinflammatory GRNs in the hypothalamus during overnutrition. In support of this, inhibiting PGRN cleavage attenuated HFD-induced hypothalamic inflammation and obesity progression. Our results suggest that the extracellular cleavage of microglia-derived PGRN plays a significant role in promoting hypothalamic inflammation and obesity during periods of overnutrition. Therefore, therapies that inhibit PGRN cleavage may be beneficial for combating dietinduced obesity., (© 2024 by the American Diabetes Association.)
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- 2024
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28. Herbal medicine Oryeongsan (Wulingsan): Cardio-renal effects via modulation of renin-angiotensin system and atrial natriuretic peptide system.
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Lee HS, Kim HY, Ahn YM, and Cho KW
- Abstract
Background: Oryeongsan (Wulingsan, Goreisan) has long been used for the treatment of impaired body fluid metabolism. However, the action mechanisms have not been clearly defined. Recently, effects of Oryeongsan on the body fluid and Na
+ metabolism and the action mechanisms have been shown more clearly. The present review focuses on the recent findings on the effects of Oryeongsan in the cardio-renal system in relation with body fluid metabolism and action mechanisms leading to a decrease in blood pressure in animal models of hypertension., Methods: The new and recent findings were searched by using searching systems including PubMed-NCBI and Google-Scholar., Results: Oryeongsan induced an increase in glomerular filtration rate, and natriuresis and diuresis with a decreased osmolality and resulted in a contraction of the body fluid and Na+ balance. These findings were associated with a suppression of abundance of Na+ - H+ -exchanger isoform 3 expression and V2 receptor/aquaporin2 water channel signaling pathway in the kidney. Further, treatment with Oryeongsan accentuated atrial natriuretic peptide secretion in the atria from spontaneously hypertensive rats in which the secretion was suppressed. In addition, Oryeongsan ameliorated impaired vasodilation in spontaneously hypertensive rats., Conclusion: The effects of Oryeongsan in the kidney, atria, and vessel were accompanied by a suppression of AT1 receptor and concurrent accentuation of abundance of AT2 /Mas receptors expression and modulation of the natriuretic peptide system in these organs from hypertensive rats. The review shows multiple sites of action of Oryeongsan and mechanisms involved in the regulation of volume and pressure homeostasis in the body., Competing Interests: The authors declare that they have no conflicts of interest., (© 2024 Korea Institute of Oriental Medicine. Published by Elsevier B.V.)- Published
- 2024
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29. Long-term tracking of glycosylated hemoglobin levels across the lifespan in type 1 diabetes: from infants to young adults.
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Kim S, Kim SJ, Cho KW, Song K, Lee M, Suh J, Chae HW, Kim HS, and Kwon A
- Abstract
Purpose: Glycosylated hemoglobin (HbA1c) is commonly used as a monitoring tool in diabetes. Due to the potential influence of insulin resistance (IR), HbA1c level may fluctuate over a person's lifetime. This study explores the long-term tracking of HbA1c level in individuals diagnosed with type 1 diabetes mellitus (T1DM) from infancy to early adulthood., Methods: The HbA1c levels in 275 individuals (121 males, 43.8%) diagnosed with T1DM were tracked for an average of 9.4 years. The distribution of HbA1c levels was evaluated according to age with subgroups divided by gender, use of continuous glucose monitoring (CGM), and the presence of complications., Results: HbA1c levels were highest at the age of 1 year and then declined until age 4, followed by a significant increase, reaching a maximum at ages 15-16 years. The levels subsequently gradually decreased until early adulthood. This pattern was observed in both sexes, but it was more pronounced in females. Additionally, HbA1c levels were higher in CGM nonusers compared with CGM users; however, regardless of CGM usage, an age-dependent pattern was observed. Furthermore, diabetic complications occurred in 26.8% of individuals, and the age-dependent pattern was observed irrespective of diabetic complications, although HbA1c levels were higher in individuals with diabetic complications., Conclusion: HbA1c levels vary throughout the lifespan, with higher levels during adolescence. This trend is observed regardless of sex and CGM usage, potentially due to physiological IR observed during adolescence. Hence, physiological IR should be considered when interpretating HbA1c levels during adolescence.
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- 2024
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30. Sleep loss and emotion: A systematic review and meta-analysis of over 50 years of experimental research.
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Palmer CA, Bower JL, Cho KW, Clementi MA, Lau S, Oosterhoff B, and Alfano CA
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- Humans, Adolescent, Adult, Anxiety psychology, Anxiety physiopathology, Depression psychology, Middle Aged, Young Adult, Child, Aged, Emotions physiology, Sleep Deprivation psychology, Sleep Deprivation physiopathology
- Abstract
In a largely sleep-deprived society, quantifying the effects of sleep loss on emotion is critical for promoting psychological health. This preregistered systematic review and meta-analysis quantified the effects of various forms of sleep loss on multiple aspects of emotional experiences. Eligible studies used experimental reductions of sleep via total sleep deprivation, partial sleep restriction, or sleep fragmentation in healthy populations to examine effects on positive affect, negative affect, general mood disturbances, emotional reactivity, anxiety symptoms, and/or depressive symptoms. In total, 1,338 effect sizes across 154 studies were included ( N = 5,717; participant age range = 7-79 years). Random effects models were conducted, and all forms of sleep loss resulted in reduced positive affect (standardized mean difference [SMD] = -0.27 to -1.14), increased anxiety symptoms (SMD = 0.57-0.63), and blunted arousal in response to emotional stimuli (SMD = -0.20 to -0.53). Findings for negative affect, reports of emotional valence in response to emotional stimuli, and depressive symptoms were mixed and depended on the type of sleep loss. Nonlinear effects for the amount of sleep loss as well as differences based on the stage of sleep restricted (i.e., rapid eye movement sleep or slow-wave sleep) were also detected. This study represents the most comprehensive quantitative synthesis of experimental sleep and emotion research to date and provides strong evidence that periods of extended wakefulness, shortened sleep duration, and/or nighttime awakenings adversely influence human emotional functioning. Findings provide an integrative foundation for future research on sleep and emotion and elucidate the precise ways that inadequate sleep may impact our daytime emotional lives. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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- 2024
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31. Obese visceral adipose dendritic cells downregulate regulatory T cell development through IL-33.
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Soedono S, Sharlene S, Vo DHN, Averia M, Rosalie EE, Lee YK, and Cho KW
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- Humans, Interleukin-1 Receptor-Like 1 Protein metabolism, Obesity metabolism, Dendritic Cells metabolism, T-Lymphocytes, Regulatory metabolism, Interleukin-33 metabolism
- Abstract
Regulatory T cells (Tregs) residing in visceral adipose tissue (VAT) play a pivotal role in regulating tissue inflammation and metabolic dysfunction associated with obesity. However, the specific phenotypic and functional characteristics of Tregs in obese VAT, as well as the regulatory mechanisms shaping them, remain elusive. This study demonstrates that obesity selectively reduces Tregs in VAT, characterized by restrained proliferation, heightened PD-1 expression, and diminished ST2 expression. Additionally, obese VAT displays distinctive maturation of dendritic cells (DCs), marked by elevated expressions of MHC-II, CD86, and PD-L1, which are inversely correlated with VAT Tregs. In an in vitro co-culture experiment, only obese VAT DCs, not macrophages or DCs from subcutaneous adipose tissue (SAT) and spleen, result in decreased Treg differentiation and proliferation. Furthermore, Tregs differentiated by obese VAT DCs exhibit distinct characteristics resembling those of Tregs in obese VAT, such as reduced ST2 and IL-10 expression. Mechanistically, obesity lowers IL-33 production in VAT DCs, contributing to the diminished Treg differentiation. These findings collectively underscore the critical role of VAT DCs in modulating Treg generation and shaping Treg phenotype and function during obesity, potentially contributing to the regulation of VAT Treg populations., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Soedono, Sharlene, Vo, Averia, Rosalie, Lee and Cho.)
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- 2024
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32. Herbal medicine (Oryeongsan) for fluid and sodium balance in renal cortex of spontaneously hypertensive rats.
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Ahn YM, Kim HY, Kang DG, Cho KW, and Lee HS
- Abstract
Background: Herbal medicine Oryeongsan (ORS), also known as Wulingsan in Chinesehas been used for the treatment of impaired body fluid balance. However, the mechanisms involved are not clearly defined. The purpose of the present study was to identify the actions of ORS on the renal excretory function and blood pressure (BP) and to define the mechanisms involved in association with renin-angiotensin system (RAS) and natriuretic peptide system (NPS) in spontaneously hypertensive rats (SHR), an animal model of human essential hypertension., Methods: Changes in urine volume (UV), excretion of electrolytes including Na
+ (urinary excretion of Na+ (UNa V)) were measured. RT-PCR was performed to trace the changes in expression of RAS, NPS and sodium (Na+ )-hydrogen (H+ ) exchanger 3 (NHE3) in the renal cortex., Results: In the SHR treated with vehicle (SHR-V) group, UV and UNa V were suppressed and the Na+ balance was maintained at the higher levels leading to an increase in BP compared to WKY-V group. These were accompanied by an increase in NHE3 expression with an accentuation of angiotensin I converting enzyme-angiotensin II type 1 (ACE-AT1 ) receptor and concurrent suppression of angiotensin II type 2 (AT2 ) receptor/ACE2-Mas receptor expression in the renal cortex. Chronic treatment with ORS increased UV and UNa V, and decreased the Na+ and water balance with a decrease in BP in the ORS-treated SHR-ORS group compared to SHR-V. These were accompanied by a decrease in NHE3 expression with a suppression of ACE-AT1 receptor and concurrent accentuation of AT2 /ACE2-Mas receptor., Conclusion: The present study shows that ORS reduced BP with a decrease in Na+ and water retention by a suppression of NHE3 expression via modulation of RAS and NPS in SHR. The present study provides pharmacological rationale for the treatment of hypertension with ORS in SHR., (© 2024 Korea Institute of Oriental Medicine. Published by Elsevier B.V.)- Published
- 2024
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33. Amoxicillin-Induced Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) Syndrome With Acute Onset of Diffuse Rash and Acute Kidney Injury (AKI).
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Cortes M, Cho KW, Chowdhury NM, Mays JN, and Shin CH
- Abstract
Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is an uncommon and potentially fatal adverse drug reaction that can affect individuals with immunosuppression, viral reactivation, pharmacogenetic susceptibility, and recent exposures to new medications. Due to the ambiguous symptomology of DRESS syndrome along with a lack of diagnosis and treatment criteria, there can be delays in diagnosis and management. Here, we present a case of a 60-year-old female with an uncommon presentation of DRESS syndrome due to a less commonly implicated drug. We aim to bring awareness to the various presentations associated with DRESS syndrome and inform readers about current diagnostic and treatment modalities used today. In addition, this case serves to provide insights that further evidence is needed to have standardized guidelines in place to effectively diagnose and manage affected patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Cortes et al.)
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- 2024
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34. Response by Cho and Yoon to Letter Regarding Article, "Polycomb Group Protein CBX7 Represses Cardiomyocyte Proliferation Through Modulation of the TARDBP/RBM38 Axis".
- Author
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Cho KW and Yoon YS
- Subjects
- Humans, Polycomb-Group Proteins metabolism, Cell Proliferation, RNA-Binding Proteins, Myocytes, Cardiac metabolism, Polycomb Repressive Complex 1 metabolism
- Abstract
Competing Interests: Disclosures None.
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- 2023
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35. Polycomb Group Protein CBX7 Represses Cardiomyocyte Proliferation Through Modulation of the TARDBP/RBM38 Axis.
- Author
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Cho KW, Andrade M, Bae S, Kim S, Eyun Kim J, Jang EY, Lee S, Husain A, Sutliff RL, Calvert JW, Park C, and Yoon YS
- Subjects
- Animals, Mice, Animals, Newborn, Cell Proliferation, Mice, Knockout, Polycomb-Group Proteins metabolism, DNA-Binding Proteins metabolism, Myocytes, Cardiac metabolism
- Abstract
Background: Shortly after birth, cardiomyocytes exit the cell cycle and cease proliferation. At present, the regulatory mechanisms for this loss of proliferative capacity are poorly understood. CBX7 (chromobox 7), a polycomb group (PcG) protein, regulates the cell cycle, but its role in cardiomyocyte proliferation is unknown., Methods: We profiled CBX7 expression in the mouse hearts through quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. We overexpressed CBX7 in neonatal mouse cardiomyocytes through adenoviral transduction. We knocked down CBX7 by using constitutive and inducible conditional knockout mice ( Tnnt2-Cre;Cbx7
fl/+ and Myh6-MCM;Cbx7fl/fl , respectively). We measured cardiomyocyte proliferation by immunostaining of proliferation markers such as Ki67, phospho-histone 3, and cyclin B1. To examine the role of CBX7 in cardiac regeneration, we used neonatal cardiac apical resection and adult myocardial infarction models. We examined the mechanism of CBX7-mediated repression of cardiomyocyte proliferation through coimmunoprecipitation, mass spectrometry, and other molecular techniques., Results: We explored Cbx7 expression in the heart and found that mRNA expression abruptly increased after birth and was sustained throughout adulthood. Overexpression of CBX7 through adenoviral transduction reduced proliferation of neonatal cardiomyocytes and promoted their multinucleation. On the other hand, genetic inactivation of Cbx7 increased proliferation of cardiomyocytes and impeded cardiac maturation during postnatal heart growth. Genetic ablation of Cbx7 promoted regeneration of neonatal and adult injured hearts. Mechanistically, CBX7 interacted with TARDBP (TAR DNA-binding protein 43) and positively regulated its downstream target, RBM38 (RNA Binding Motif Protein 38), in a TARDBP-dependent manner. Overexpression of RBM38 inhibited the proliferation of CBX7-depleted neonatal cardiomyocytes., Conclusions: Our results demonstrate that CBX7 directs the cell cycle exit of cardiomyocytes during the postnatal period by regulating its downstream targets TARDBP and RBM38. This is the first study to demonstrate the role of CBX7 in regulation of cardiomyocyte proliferation, and CBX7 could be an important target for cardiac regeneration., Competing Interests: Disclosures None.- Published
- 2023
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36. TNFα-induced NLRP3 inflammasome mediates adipocyte dysfunction and activates macrophages through adipocyte-derived lipocalin 2.
- Author
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Javaid HMA, Ko E, Joo EJ, Kwon SH, Park JH, Shin S, Cho KW, and Huh JY
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- Humans, Mice, Animals, Lipocalin-2 genetics, Lipocalin-2 metabolism, Tumor Necrosis Factor-alpha pharmacology, Culture Media, Conditioned pharmacology, Adipocytes metabolism, Macrophages metabolism, Obesity metabolism, Mice, Knockout, Caspases metabolism, Caspases pharmacology, Inflammasomes metabolism, NLR Family, Pyrin Domain-Containing 3 Protein genetics, NLR Family, Pyrin Domain-Containing 3 Protein metabolism
- Abstract
Background and Aims: Obesity is a state of chronic low-grade systemic inflammation. Recent studies showed that NLRP3 inflammasome initiates metabolic dysregulation in adipose tissues, primarily through activation of adipose tissue infiltrated macrophages. However, the mechanism of NLRP3 activation and its role in adipocytes remains elusive. Therefore, we aimed to examine the activation of TNFα-induced NLRP3 inflammasome in adipocytes and its role on adipocyte metabolism and crosstalk with macrophages., Methods: The effect of TNFα on adipocyte NLRP3 inflammasome activation was measured. Caspase-1 inhibitor (Ac-YVAD-cmk) and primary adipocytes from NLRP3 and caspase-1 knockout mice were utilized to block NLRP3 inflammasome activation. Biomarkers were measured by using real-time PCR, western blotting, immunofluorescence staining, and enzyme assay kits. Conditioned media from TNFα-stimulated adipocytes was used to establish the adipocyte-macrophage crosstalk. Chromatin immunoprecipitation assay was used to identify the role of NLRP3 as a transcription factor. Mouse and human adipose tissues were collected for correlation analysis., Results: TNFα treatment induced NLRP3 expression and caspase-1 activity in adipocytes, partly through autophagy dysregulation. The activated adipocyte NLRP3 inflammasome participated in mitochondrial dysfunction and insulin resistance, as evidenced by the amelioration of these effects in Ac-YVAD-cmk treated 3T3-L1 cells or primary adipocytes isolated from NLRP3 and caspase-1 knockout mice. Particularly, the adipocyte NLRP3 inflammasome was involved in glucose uptake regulation. Also, TNFα induced expression and secretion of lipocalin 2 (Lcn2) in a NLRP3-dependent manner. NLRP3 could bind to the promoter and transcriptionally regulate Lcn2 in adipocytes. Treatment with adipocyte conditioned media revealed that adipocyte-derived Lcn2 was responsible for macrophage NLRP3 inflammasome activation, working as a second signal. Adipocytes isolated from high-fat diet mice and adipose tissue from obese individuals showed a positive correlation between NLRP3 and Lcn2 gene expression., Conclusions: This study highlights the importance of adipocyte NLRP3 inflammasome activation and novel role of TNFα-NLRP3-Lcn2 axis in adipose tissue. It adds rational for the current development of NLRP3 inhibitors for treating obesity-induced metabolic diseases., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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37. Physcion prevents high-fat diet-induced endothelial dysfunction by inhibiting oxidative stress and endoplasmic reticulum stress pathways.
- Author
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Wang YH, Liu YP, Zhu JQ, Zhou GH, Zhang F, An Q, Yang J, Cho KW, Jin SN, and Wen JF
- Subjects
- Animals, Humans, Rats, Endoplasmic Reticulum Stress, Endothelium, Vascular, Human Umbilical Vein Endothelial Cells, Obesity etiology, Obesity prevention & control, Obesity metabolism, Oxidative Stress, Diet, High-Fat, NF-E2-Related Factor 2 metabolism
- Abstract
High-fat diet (HFD)-induced obesity leads endothelial dysfunction and contributes to cardiovascular diseases. Palmitic acid (PA), a free fatty acid, is the main component of dietary saturated fat. Physcion, a chemical ingredient from Rhubarb, has been shown anti-hypertensive, anti-bacteria, and anti-tumor properties. However, the effects of physcion on endothelial dysfunction under HFD-induced obesity have not been reported. The purpose of the present study was to define the protective effect of physcion on HFD-induced endothelial dysfunction and its mechanisms involved. Obesity rat model was induced by HFD for 12 weeks. A rat thoracic aortic ring model was used to investigate the effects of physcion on HFD-induced impairment of vasorelaxation. Endothelial cell injury model was constructed in human umbilical vein endothelial cells (HUVECs) by treating with PA (0.25 mM) for 24 h. The results revealed that physcion reduced body weight and the levels of plasma TG, prevented impairment of endothelium-dependent relaxation in HFD-fed rats. In PA-injured HUVECs, physcion inhibited impaired viability, apoptosis and inflammation. Physcion also suppressed PA-induced both oxidative stress and ER stress in HUVECs. Furthermore, physcion increased PA-induced decrease in the activation of eNOS/Nrf2 signaling in HUVECs. These findings suggest that physcion has a significant beneficial effect on regulating HFD-induced endothelial dysfunction, which may be related to the inhibition of oxidative stress and ER stress through activation of eNOS/Nrf2 signaling pathway., Competing Interests: Declaration of competing interest The authors declare that there are no competing interests associated with the manuscript., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
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38. SCAP deficiency facilitates obesity and insulin resistance through shifting adipose tissue macrophage polarization.
- Author
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Lee JH, Lee SH, Lee EH, Cho JY, Song DK, Lee YJ, Kwon TK, Oh BC, Cho KW, Osborne TF, Jeon TI, and Im SS
- Subjects
- Mice, Animals, Sterol Regulatory Element Binding Protein 1, Intracellular Signaling Peptides and Proteins, Cholesterol, Obesity, Insulin Resistance
- Abstract
Introduction: Sterol regulatory element binding protein (SREBP) cleavage-associating protein (SCAP) is a sterol-regulated escort protein that translocates SREBPs from the endoplasmic reticulum to the Golgi apparatus, thereby activating lipid metabolism and cholesterol synthesis. Although SCAP regulates lipid metabolism in metabolic tissues, such as the liver and muscle, the effect of macrophage-specific SCAP deficiency in adipose tissue macrophages (ATMs) of patients with metabolic diseases is not completely understood., Objectives: Here, we examined the function of SCAP in high-fat/high-sucrose diet (HFHS)-fed mice and investigated its role in the polarization of classical activated macrophages in adipose tissue., Methods: Macrophage-specific SCAP knockout (mKO) mice were generated through crossbreeding lysozyme 2-cre mice with SCAP floxed mice which were then fed HFHS for 12 weeks. Primary macrophages were derived from bone marrow cells and analyzed further., Results: We found that fat accumulation and the appearance of proinflammatory M1 macrophages were both higher in HFHS-fed SCAP mKO mice relative to floxed control mice. We traced the effect to a defect in the lipopolysaccharide-mediated increase in SREBP-1a that occurs in control but not SCAP mKO mice. Mechanistically, SREBP-1a increased expression of cholesterol 25-hydroxylase transcription, resulting in an increase in the production of 25-hydroxycholesterol (25-HC), an endogenous agonist of liver X receptor alpha (LXRα) which increased expression of cholesterol efflux to limit cholesterol accumulation and M1 polarization. In the absence of SCAP mediated activation of SREBP-1a, increased M1 macrophage polarization resulted in reduced cholesterol efflux downstream from 25-HC-dependent LXRα activation., Conclusion: Overall, the activation of the SCAP-SREBP-1a pathway in macrophages may provide a novel therapeutic strategy that ameliorates obesity by controlling cholesterol homeostasis in ATMs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Production and hosting by Elsevier B.V.)
- Published
- 2023
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39. Emodin protects against homocysteine-induced cardiac dysfunction by inhibiting oxidative stress via MAPK and Akt/eNOS/NO signaling pathways.
- Author
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Liu YP, Zhou GH, Song X, Wang YH, Zhang F, Chen QQ, Cho KW, Jin SN, and Wen JF
- Subjects
- Rats, Animals, Oxidative Stress, Signal Transduction, Antioxidants pharmacology, Homocysteine metabolism, Proto-Oncogene Proteins c-akt metabolism, Emodin pharmacology
- Abstract
Elevated levels of plasma homocysteine (Hcy) causes severe cardiac dysfunction, which is closely associated with oxidative stress. Emodin, a naturally occurring anthraquinone derivative, has been shown to exert antioxidant and anti-apoptosis activities. However, whether emodin could protect against Hcy-induced cardiac dysfunction remains unknown. The current study aimed to investigate the effects of emodin on the Hcy-induced cardiac dysfunction and its molecular mechanisms. Rats were fed a methionine diet to establish the animal model of hyperhomocysteinemia (HHcy). H9C2 cells were incubated with Hcy to induce a cell model of Hcy-injured cardiomyocytes. ELISA, HE staining, carotid artery and left ventricular cannulation, MTT, fluorescence staining, flow cytometry and western blotting were used in this study. Emodin significantly alleviated the structural damage of the myocardium and cardiac dysfunction from HHcy rats. Emodin prevented apoptosis and the collapse of MMP in the Hcy-treated H9C2 cells in vitro. Further, emodin reversed the Hcy-induced apoptosis-related biochemical changes including decreased Bcl-2/Bax protein ratio, and increased protein expression of Caspase-9/3. Moreover, emodin suppressed oxidative stress in Hcy-treated H9C2 cells. Mechanistically, emodin significantly inhibited the Hcy-activated MAPK by reducing ROS generation in H9C2 cells. Furthermore, emodin upregulated NO production by promoting the protein phosphorylation of Akt and eNOS in injured cells. The present study shows that emodin protects against Hcy-induced cardiac dysfunction by inhibiting oxidative stress via MAPK and Akt/eNOS/NO signaling pathways., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)
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- 2023
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40. The role of paracrine crosstalk between myeloid and endothelial cells in myocardial angiogenesis and infarcted heart repair.
- Author
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Cho KW, Bae S, and Yoon YS
- Abstract
Competing Interests: Conflicts of interest All authors declared that there are no conflicts of interest.
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- 2023
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41. Ginsenoside Rd ameliorates muscle wasting by suppressing the signal transducer and activator of transcription 3 pathway.
- Author
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Wijaya YT, Setiawan T, Sari IN, Park K, Lee CH, Cho KW, Lee YK, Lim JY, Yoon JK, Lee SH, and Kwon HY
- Subjects
- Animals, Humans, Mice, Cachexia etiology, Molecular Docking Simulation, Muscle Fibers, Skeletal metabolism, Muscular Atrophy drug therapy, Muscular Atrophy etiology, Muscular Atrophy metabolism, Tumor Necrosis Factor-alpha, Carcinoma, Lewis Lung complications, Myoblasts, Skeletal, STAT3 Transcription Factor metabolism, STAT3 Transcription Factor pharmacology
- Abstract
Background: The effects of some drugs, aging, cancers, and other diseases can cause muscle wasting. Currently, there are no effective drugs for treating muscle wasting. In this study, the effects of ginsenoside Rd (GRd) on muscle wasting were studied., Methods: Tumour necrosis factor-alpha (TNF-α)/interferon-gamma (IFN-γ)-induced myotube atrophy in mouse C2C12 and human skeletal myoblasts (HSkM) was evaluated based on cell thickness. Atrophy-related signalling, reactive oxygen species (ROS) level, mitochondrial membrane potential, and mitochondrial number were assessed. GRd (10 mg/kg body weight) was orally administered to aged mice (23-24 months old) and tumour-bearing (Lewis lung carcinoma [LLC1] or CT26) mice for 5 weeks and 16 days, respectively. Body weight, grip strength, inverted hanging time, and muscle weight were assessed. Histological analysis was also performed to assess the effects of GRd. The evolutionary chemical binding similarity (ECBS) approach, molecular docking, Biacore assay, and signal transducer and activator of transcription (STAT) 3 reporter assay were used to identify targets of GRd., Results: GRd significantly induced hypertrophy in the C2C12 and HSkM myotubes (average diameter 50.8 ± 2.6% and 49.9% ± 3.7% higher at 100 nM, vs. control, P ≤ 0.001). GRd treatment ameliorated aging- and cancer-induced (LLC1 or CT26) muscle atrophy in mice, which was evidenced by significant increases in grip strength, hanging time, muscle mass, and muscle tissue cross-sectional area (1.3-fold to 4.6-fold, vs. vehicle, P ≤ 0.05; P ≤ 0.01; P ≤ 0.001). STAT3 was found to be a possible target of GRd by the ECBS approach and molecular docking assay. Validation of direct interaction between GRd and STAT3 was confirmed through Biacore analysis. GRd also inhibited STAT3 phosphorylation and STAT3 reporter activity, which led to the inhibition of STAT3 nuclear translocation and the suppression of downstream targets of STAT3, such as atrogin-1, muscle-specific RING finger protein (MuRF-1), and myostatin (MSTN) (29.0 ± 11.2% to 84.3 ± 30.5%, vs. vehicle, P ≤ 0.05; P ≤ 0.01; P ≤ 0.001). Additionally, GRd scavenged ROS (91.7 ± 1.4% reduction at 1 nM, vs. vehicle, P ≤ 0.001), inhibited TNF-α-induced dysregulation of ROS level, and improved mitochondrial integrity (P ≤ 0.05; P ≤ 0.01; P ≤ 0.001)., Conclusions: GRd ameliorates aging- and cancer-induced muscle wasting. Our findings suggest that GRd may be a novel therapeutic agent or adjuvant for reversing muscle wasting., (© 2022 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.)
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- 2022
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42. 12-OAHSA is a component of olive oil and mitigates obesity-induced inflammation.
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Moyo KM, Choi J, Chang J, Soedono S, Nguyet DVH, Song YR, Park SJ, Go GW, Lee DY, and Cho KW
- Subjects
- Mice, Animals, Olive Oil pharmacology, Inflammation prevention & control, Inflammation metabolism, Fatty Acids metabolism, Stearic Acids, Corn Oil, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents therapeutic use, Oleic Acid, Obesity metabolism
- Abstract
Fatty acid esters of hydroxyl fatty acids (FAHFAs) are a new family of endogenous lipids that exert anti-inflammatory action. Among the various FAHFA isomers, the dietary source of oleic acid-hydroxy stearic acid (OAHSA) and its anti-inflammatory functions are poorly understood. This study investigated the composition of OAHSA isomers in dietary oils and the impact of 12-OAHSA on obesity-induced inflammation. Liquid chromatography with tandem mass spectrometry analysis revealed that various dietary oils, including fish oil, corn oil, palm oil, soybean oil, and olive oil, present a wide variation in OAHSA profiles and amounts. The highest amounts of total OAHSAs are present in olive oil including 12-OAHSA. Compared to vehicle-treated obese mice, administration of 12-OAHSA significantly improved glucose homeostasis, independent of body weight. 12-OAHSA-treated mice displayed significantly reduced accumulation of CD11c
+ adipose tissue macrophages, and CD4+ /CD8+ adipose tissue T lymphocytes. Concomitantly, the expression of pro-inflammatory cytokine genes and the nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway were significantly decreased in the 12-OAHSA-treated adipose tissue, while the expression of the anti-inflammatory gene Il10 was markedly increased. Moreover, in vitro cell culture experiments showed that 12-OAHSA significantly inhibited the lipopolysaccharides-induced inflammatory response in macrophages by suppressing the nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway. Collectively, these results indicated that 12-OAHSA, as a component of olive oil, mitigates obesity-induced insulin resistance by regulating AT inflammation. Therefore, 12-OAHSA could be used as a novel nutritional intervention against obesity-associated metabolic dysregulation., (Copyright © 2022. Published by Elsevier Inc.)- Published
- 2022
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43. TBK1-mTOR Signaling Attenuates Obesity-Linked Hyperglycemia and Insulin Resistance.
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Bodur C, Kazyken D, Huang K, Tooley AS, Cho KW, Barnes TM, Lumeng CN, Myers MG, and Fingar DC
- Subjects
- Mice, Animals, Multiprotein Complexes metabolism, TOR Serine-Threonine Kinases metabolism, Mechanistic Target of Rapamycin Complex 1 metabolism, Mechanistic Target of Rapamycin Complex 2, Sirolimus pharmacology, Insulin metabolism, Obesity genetics, Mice, Obese, Glucose, Protein Serine-Threonine Kinases genetics, Insulin Resistance genetics, Hyperglycemia genetics
- Abstract
The innate immune kinase TBK1 (TANK-binding kinase 1) responds to microbial-derived signals to initiate responses against viral and bacterial pathogens. More recent work implicates TBK1 in metabolism and tumorigenesis. The kinase mTOR (mechanistic target of rapamycin) integrates diverse environmental cues to control fundamental cellular processes. Our prior work demonstrated in cells that TBK1 phosphorylates mTOR (on S2159) to increase mTORC1 and mTORC2 catalytic activity and signaling. Here we investigate a role for TBK1-mTOR signaling in control of glucose metabolism in vivo. We find that mice with diet-induced obesity (DIO) but not lean mice bearing a whole-body "TBK1-resistant" Mtor S2159A knock-in allele (MtorA/A) display exacerbated hyperglycemia and systemic insulin resistance with no change in energy balance. Mechanistically, Mtor S2159A knock-in in DIO mice reduces mTORC1 and mTORC2 signaling in response to insulin and innate immune agonists, reduces anti-inflammatory gene expression in adipose tissue, and blunts anti-inflammatory macrophage M2 polarization, phenotypes shared by mice with tissue-specific inactivation of TBK1 or mTOR complexes. Tissues from DIO mice display elevated TBK1 activity and mTOR S2159 phosphorylation relative to lean mice. We propose a model whereby obesity-associated signals increase TBK1 activity and mTOR phosphorylation, which boost mTORC1 and mTORC2 signaling in parallel to the insulin pathway, thereby attenuating insulin resistance to improve glycemic control during diet-induced obesity., (© 2022 by the American Diabetes Association.)
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- 2022
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44. Mechanical Stress Improves Fat Graft Survival by Promoting Adipose-Derived Stem Cells Proliferation.
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Chun JJ, Chang J, Soedono S, Oh J, Kim YJ, Wee SY, Cho KW, and Choi CY
- Subjects
- Cell Proliferation, Stem Cells, Stress, Mechanical, Adipose Tissue, Graft Survival
- Abstract
Cell-assisted lipotransfer (CAL), defined as co-transplantation of aspirated fat with enrichment of adipose-derived stem cells (ASCs), is a novel technique for cosmetic and reconstructive surgery to overcome the low survival rate of traditional fat grafting. However, clinically approved techniques for increasing the potency of ASCs in CAL have not been developed yet. As a more clinically applicable method, we used mechanical stress to reinforce the potency of ASCs. Mechanical stress was applied to the inguinal fat pad by needling . Morphological and cellular changes in adipose tissues were examined by flow cytometric analysis 1, 3, 5, and 7 days after the procedure. The proliferation and adipogenesis potencies of ASCs were evaluated. CAL with ASCs treated with mechanical stress or sham control were performed, and engraftment was determined at 4 weeks post-operation. Flow cytometry analysis revealed that mechanical stress significantly increased the number as well as the frequency of ASC proliferation in fat. Proliferation assays and adipocyte-specific marker gene analysis revealed that mechanical stress promoted proliferation potential but did not affect the differentiation capacity of ASCs. Moreover, CAL with cells derived from mechanical stress-treated fat increased the engraftment. Our results indicate that mechanical stress may be a simple method for improving the efficacy of CAL by enhancing the proliferation potency of ASCs.
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- 2022
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45. Adenosine-Prefabricated Adipose Tissue Improves Fat Graft Survival by Promoting VEGF-Dependent Angiogenesis.
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Chang J, Song WJ, Soedono S, Sharlene S, Kim YJ, Choi CY, and Cho KW
- Subjects
- Adenosine metabolism, Adenosine pharmacology, Adipose Tissue metabolism, Animals, Axitinib pharmacology, Endothelial Cells metabolism, Mice, Receptors, Vascular Endothelial Growth Factor metabolism, Vascular Endothelial Growth Factors metabolism, Vascular Endothelial Growth Factors pharmacology, von Willebrand Factor metabolism, von Willebrand Factor pharmacology, Graft Survival, Vascular Endothelial Growth Factor A metabolism
- Abstract
Background: Angiogenesis plays an important role in determining the fat graft survival. However, clinical preconditioning techniques that target angiogenesis during fat grafting have not been established so far. Adenosine has emerged as a regulator of angiogenesis under hypoxic conditions; therefore, the aim of this study was to investigate the effects and underlying mechanisms of adenosine prefabrication on fat graft survival., Methods: In the first animal study, a total of 32 mice were transplanted with fat prefabricated with vehicle (Control, N = 16) or adenosine (Adenosine, N = 16). In the second animal study, 24 mice were divided into three groups based on the type of fat graft: Control (N = 8), Adenosine (N = 8), and Axitinib (cotreatment of adenosine with axitinib, N = 8). At 1- and 4-weeks post-transplantation, grafts were evaluated by histopathological and biochemical assessment. Adenosine-induced vascular endothelial growth factor (VEGF) production and angiogenesis were determined using cell cultures., Results: The retention volumes of fat grafts in the adenosine group were significantly increased until 4 weeks. Fat grafts from the adenosine group exhibited greater structural integrity, reduced fibrosis, and increased blood vessels. The expression levels of angiogenesis-related genes, Vegfa, Vegfr1, Vegfr2, and Vwf, were elevated in the adenosine group. Furthermore, adenosine upregulated VEGF production in preadipocytes, thereby enhancing the migration of endothelial cells. Treatment with the axitinib, VEGF receptor inhibitor, abrogated the adenosine-induced angiogenesis in the fat grafts., Conclusion: Adenosine prefabrication in fat improved the graft survival by enhancing angiogenesis through the VEGF/VEGFR axis in the preadipocytes and endothelial cells. Therefore, this method may be used as a novel strategy to increase the retention rate in fat grafts., (© 2022. Korean Tissue Engineering and Regenerative Medicine Society.)
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- 2022
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46. Author Correction: Human eye-inspired soft optoelectronic device using high-density MoS 2 -graphene curved image sensor array.
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Choi C, Choi MK, Liu S, Kim M, Park OK, Im C, Kim J, Qin X, Lee GJ, Cho KW, Kim M, Joh E, Lee J, Son D, Kwon SH, Jeon NL, Song YM, Lu N, and Kim DH
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- 2022
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47. Author Correction: Curved neuromorphic image sensor array using a MoS 2 -organic heterostructure inspired by the human visual recognition system.
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Choi C, Leem J, Kim M, Taqieddin A, Cho C, Cho KW, Lee GJ, Seung H, Bae HJ, Song YM, Hyeon T, Aluru NR, Nam S, and Kim DH
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- 2022
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48. Amelioration of Hypertension by Oryeongsan through Improvements of Body Fluid and Sodium Balance: Roles of the Renin-Angiotensin System and Atrial Natriuretic Peptide System.
- Author
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Ahn YM, Kim HY, Yoon JJ, Kim HJ, Lee YJ, Yun YG, Shin HK, Cho KW, Kang DG, and Lee HS
- Abstract
Oryeongsan (Wulingsan in China and Goreisan in Japan), a formula composed of five herbal medicines, has long been used for the treatment of imbalance of the body fluid homeostasis in Asian countries. However, the mechanism by which Oryeongsan (ORS) improves the impaired body fluid and salt metabolism is not clearly defined. The present study was performed to define the role of the cardiorenal humoral system in the ORS-induced changes in blood pressure and renal function in hypertension. Experiments were performed in normotensive and two-kidney, one-clip hypertensive rats. Changes in the fluid and salt balance were measured in rats individually housed in metabolic cages. Changes in the systemic and local renin-angiotensin system (RAS) and cardiac natriuretic peptide hormone system (NPS) were evaluated. ORS water extract was administered by oral gavage (100 mg/kg daily) for 3 weeks. ORS induced diuresis and natriuresis along with an increase in glomerular filtration rate and downregulation of the Na
+ /H+ exchanger 3 (NHE3) and aquaporin 2 expression in the renal cortex and medulla, respectively. Furthermore, treatment with ORS significantly decreased systolic blood pressure with contraction of body sodium and water accumulation in hypertensive rats. ORS-induced changes were accompanied by modulation of the RAS and NPS, downregulation of the systemic RAS and cardiorenal expression of angiotensin-converting enzyme (ACE) and angiotensin II subtype 1 (AT1 ) receptor, and upregulation of the plasma ANP concentration and cardiorenal expression of ANP, ACE2, Mas receptor, and AT2 receptor. These findings indicate that ORS induces beneficial effects on the high blood pressure through modulation of the RAS and NPS of the cardiorenal system, suppression of the prohypertensive ACE-AT1 receptor pathway and NHE3, accentuation of the antihypertensive ACE2-Mas axis/AT2 receptor pathway in the kidney, suppression of the systemic RAS, and elevation of the plasma ANP levels and its synthesis in the heart. The present study provides a biological basis for the use of ORS in the treatment of impaired volume and pressure homeostasis., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2022 You Mee Ahn et al.)- Published
- 2022
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49. "Fasting: An Effective Preconditioning Method to Increase Fat Graft Survival".
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Cha HG, Kim DG, Chang J, Song Y, Jeong S, Nam SM, Wee SY, Cho KW, and Choi CY
- Subjects
- Adipose Tissue transplantation, Animals, Mice, Mice, Inbred C57BL, X-Ray Microtomography, Fasting, Graft Survival
- Abstract
Background: Most preconditioning techniques before fat grafting require external manipulation. Since nutrition is the main factor maintaining the balance of lipogenesis and lipolysis, we hypothesized that fasting before undergoing autologous fat grafting may increase lipolysis and reduce adipocyte size, thereby improving the fat graft survival rate., Methods: C57BL/6 mice were divided into 24 h starved or fed groups. Adipose tissue lipolysis, adipogenesis, and angiogenesis-related gene expression, in fat from both groups, were analyzed. The volume and weight of the grafted fat at 4-8 weeks postoperatively were measured using micro-computed tomography. Immunohistochemistry staining and mRNA expression analysis were also performed to evaluate the effect of fasting on fat graft survival., Results: Fasting decreased adipocyte size by inducing adipose tissue lipolysis. Adipogenesis-related genes were remarkably downregulated while lipolysis-related genes and angiogenesis inducer genes were significantly upregulated in the starved adipose tissue. The mice grafted with the fat from the 24 h starved group had approximately 20% larger volumes and considerably heavier weights than those from the fed group. Increased viable adipocytes and vessels, and reduced macrophages in the fat grafts obtained from the 24 h starved group were also observed., Conclusions: Fasting for 24 h before harvesting fat increased the retention volume of fat graft by increasing angiogenesis via VEGF induction. Therefore, fasting would be a novel and reliable preconditioning strategy to improve graft survival in autologous fat grafting., No Level Assigned: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature and International Society of Aesthetic Plastic Surgery.)
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- 2022
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50. Sterile Neutrophilic Dermatosis (Sweet's Syndrome) Associated With Systemic Inflammatory Response Syndrome in a Maltese Dog: A Case Report.
- Author
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Cho A, Bae H, Shin S, Kim Y, Jeon Y, Hyun JE, Cho KW, Jung DI, Kim DY, and Yu D
- Abstract
We report a rare case of sterile neutrophilic dermatosis (Sweet's syndrome) accompanied by systemic inflammatory response syndrome. A 5-year-old, neutered male Maltese dog presented with extensive crusts on the whole-body surface and multifocal erosions and plaques on the four limbs. The lesions had been present for two months and did not respond to antibiotics before the presentation. In addition, the dog was lethargic, anorexic, and febrile, with joint swelling. A clinicopathologic analysis revealed neutrophilic leukocytosis with left shift and increased C-reactive protein level. Furthermore, a histopathological examination showed moderate to severe inflammatory infiltrates consisting predominantly of neutrophils from the superficial to the deep dermis. There was no evidence of bacterial or fungal infections, and autoimmune diseases, such as pemphigus, systemic lupus erythematosus, and erythema multiforme, were excluded. Sweet's syndrome, a rare skin disorder, associated with systemic inflammation was diagnosed, and the cutaneous lesions and systemic inflammation disappeared after prolonged steroid administration., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Cho, Bae, Shin, Kim, Jeon, Hyun, Cho, Jung, Kim and Yu.)
- Published
- 2022
- Full Text
- View/download PDF
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