Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
655
result(s) for
"Park, Soo-Kyung"
Sort by:
A common missense variant in NUDT15 confers susceptibility to thiopurine-induced leukopenia
by
Liu, Jianjun
,
McGovern, Dermot P B
,
Baek, Jiwon
in
45/43
,
631/208/205/2138
,
692/699/1503/257/1402
2014
Kyuyoung Song and colleagues report the results of a two-stage association study of thiopurine-induced early leukopenia in individuals undergoing treatment for Crohn's disease. They find a missense variant in NUDT15 associated with substantially higher risk of developing this life-threatening complication to thiopurine therapy.
Thiopurine therapy, commonly used in autoimmune conditions, can be complicated by life-threatening leukopenia. This leukopenia is associated with genetic variation in
TPMT
(encoding thiopurine S-methyltransferase). Despite a lower frequency of
TPMT
mutations in Asians, the incidence of thiopurine-induced leukopenia is higher in Asians than in individuals of European descent. Here we performed an Immunochip-based 2-stage association study in 978 Korean subjects with Crohn's disease treated with thiopurines. We identified a nonsynonymous SNP in
NUDT15
(encoding p.Arg139Cys) that was strongly associated with thiopurine-induced early leukopenia (odds ratio (OR) = 35.6;
P
combined
= 4.88 × 10
−94
). In Koreans, this variant demonstrated sensitivity and specificity of 89.4% and 93.2%, respectively, for thiopurine-induced early leukopenia (in comparison to 12.1% and 97.6% for
TPMT
variants). Although rare, this SNP was also strongly associated with thiopurine-induced leukopenia in subjects with inflammatory bowel disease of European descent (OR = 9.50;
P
= 4.64 × 10
−4
). Thus,
NUDT15
is a pharmacogenetic determinant for thiopurine-induced leukopenia in diverse populations.
Journal Article
Meta-analysis of 16S rRNA microbial data identified alterations of the gut microbiota in COVID-19 patients during the acute and recovery phases
2022
Background
Dozens of studies have demonstrated gut dysbiosis in COVID-19 patients during the acute and recovery phases. However, a consensus on the specific COVID-19 associated bacteria is missing. In this study, we performed a meta-analysis to explore whether robust and reproducible alterations in the gut microbiota of COVID-19 patients exist across different populations.
Methods
A systematic review was conducted for studies published prior to May 2022 in electronic databases. After review, we included 16 studies that comparing the gut microbiota in COVID-19 patients to those of controls. The 16S rRNA sequence data of these studies were then re-analyzed using a standardized workflow and synthesized by meta-analysis.
Results
We found that gut bacterial diversity of COVID-19 patients in both the acute and recovery phases was consistently lower than non-COVID-19 individuals. Microbial differential abundance analysis showed depletion of anti-inflammatory butyrate-producing bacteria and enrichment of taxa with pro-inflammatory properties in COVID-19 patients during the acute phase compared to non-COVID-19 individuals. Analysis of microbial communities showed that the gut microbiota of COVID-19 recovered patients were still in unhealthy ecostates.
Conclusions
Our results provided a comprehensive synthesis to better understand gut microbial perturbations associated with COVID-19 and identified underlying biomarkers for microbiome-based diagnostics and therapeutics.
Journal Article
Extracellular Vesicles Derived from Gut Microbiota, Especially Akkermansia muciniphila, Protect the Progression of Dextran Sulfate Sodium-Induced Colitis
2013
Gut microbiota play an important part in the pathogenesis of mucosal inflammation, such as inflammatory bowel disease (IBD). However, owing to the complexity of the gut microbiota, our understanding of the roles of commensal and pathogenic bacteria in the maintenance of immune homeostasis in the gut is evolving only slowly. Here, we evaluated the role of gut microbiota and their secreting extracellular vesicles (EV) in the development of mucosal inflammation in the gut. Experimental IBD model was established by oral application of dextran sulfate sodium (DSS) to C57BL/6 mice. The composition of gut microbiota and bacteria-derived EV in stools was evaluated by metagenome sequencing using bacterial common primer of 16S rDNA. Metagenomics in the IBD mouse model showed that the change in stool EV composition was more drastic, compared to the change of bacterial composition. Oral DSS application decreased the composition of EV from Akkermansia muciniphila and Bacteroides acidifaciens in stools, whereas increased EV from TM7 phylum, especially from species DQ777900_s and AJ400239_s. In vitro pretreatment of A. muciniphila-derived EV ameliorated the production of a pro-inflammatory cytokine IL-6 from colon epithelial cells induced by Escherichia coli EV. Additionally, oral application of A. muciniphila EV also protected DSS-induced IBD phenotypes, such as body weight loss, colon length, and inflammatory cell infiltration of colon wall. Our data provides insight into the role of gut microbiota-derived EV in regulation of intestinal immunity and homeostasis, and A. muciniphila-derived EV have protective effects in the development of DSS-induced colitis.
Journal Article
Comparison of a novel mini-oral sulfate tablet and the conventional oral sulfate tablet in bowel preparation for colonoscopy: a prospective, randomized, investigator-blinded, multicenter, non-inferior, phase 3 trial
2023
Background and aimsThe use of conventional oral sulfate tablets (OSTs) has gained popularity; nonetheless, they may be not only inconvenient to swallow but also difficult to dissolve. A novel mini-OST has recently been developed to enhance compliance with conventional OST use. This study aimed to compare the efficacy, tolerability, and safety between mini-OST and conventional OST.MethodsThis was a prospective, randomized, investigator-blinded, multicenter, and non-inferior phase 3 trial conducted between September 2022 and December 2022. The efficacy, safety, and tolerability were compared between mini-OST and conventional OST.ResultsExactly 83 patients were evaluated based on a full analysis set (FAS), whereas 82 patients were evaluated as a per-protocol set (PPS). With respect to the efficacy of preparation, successful and high-quality preparation was excellent in the mini-OST and conventional OST groups on both FAS and PPS analyses, without significant differences between the two groups. On the FAS analysis, the satisfaction and tolerability scores were high in both groups, without significant differences. The first bowel movement after taking the investigational product occurred 30 min earlier in the mini-OST group than in the OST group. Mild, moderate, and severe adverse events (AEs) were comparable between the two groups; however, any AEs were more common in the mini-OST group than in the conventional OST group overall.ConclusionsCompared with conventional OST, the novel mini-OST preparation showed similar efficacy, tolerability, and safety, including mild eight solicited AEs and moderate-to-severe AEs.Clinical trial registration NCT05670470.
Journal Article
Prospective analysis of delayed colorectal post-polypectomy bleeding
2018
Backgrounds/aimsAlthough post-polypectomy bleeding is the most frequent complication after colonoscopic polypectomy, only few studies have investigated the incidence of bleeding prospectively. The aim of this study was to investigate the incidence of delayed post-polypectomy bleeding and its associated risk factors prospectively.MethodsPatients who underwent colonoscopic polypectomy at Kangbuk Samsung Hospital from January 2013 to December 2014 were prospectively enrolled in this study. Trained nurses contacted patients via telephone 7 and 30 days after polypectomy and completed a standardized questionnaire regarding the development of bleeding. Delayed post-polypectomy bleeding was categorized as minor or major and early or late bleeding. Major delayed bleeding was defined as a > 2-g/dL drop in the hemoglobin level, requiring hospitalization for control of bleeding or blood transfusion; late delayed bleeding was defined as bleeding occurring later than 24 h after polypectomy.ResultsA total of 8175 colonoscopic polypectomies were performed in 3887 patients. Overall, 133 (3.4%) patients developed delayed post-polypectomy bleeding. Among them, 90 (2.3%) and 43 (1.1%) patients developed minor and major delayed bleeding, respectively, and 39 (1.0%) patients developed late delayed bleeding. In the polyp-based multivariate analysis, young age (< 50 years; odds ratio [OR] 2.10; 95% confidence interval [CI] 1.18–3.68), aspirin use (OR 2.78; 95% CI 1.23–6.31), and polyp size of > 10 mm (OR 2.45; 95% CI 1.38–4.36) were significant risk factors for major delayed bleeding, while young age (< 50 years; OR 2.6; 95% CI 1.35–5.12) and immediate bleeding (OR 3.3; 95% CI 1.49–7.30) were significant risk factors for late delayed bleeding.ConclusionsYoung age, aspirin use, polyp size, and immediate bleeding were found to be independent risk factors for delayed post-polypectomy bleeding.
Journal Article
Quantifying intracellular trafficking of silica-coated magnetic nanoparticles in live single cells by site-specific direct stochastic optical reconstruction microscopy
2021
Background
Nanoparticles have been used for biomedical applications, including drug delivery, diagnosis, and imaging based on their unique properties derived from small size and large surface-to-volume ratio. However, concerns regarding unexpected toxicity due to the localization of nanoparticles in the cells are growing. Herein, we quantified the number of cell-internalized nanoparticles and monitored their cellular localization, which are critical factors for biomedical applications of nanoparticles.
Methods
This study investigates the intracellular trafficking of silica-coated magnetic nanoparticles containing rhodamine B isothiocyanate dye [MNPs@SiO
2
(RITC)] in various live single cells, such as HEK293, NIH3T3, and RAW 264.7 cells, using site-specific direct stochastic optical reconstruction microscopy (
d
STORM). The time-dependent subdiffraction-limit spatial resolution of the
d
STORM method allowed intracellular site-specific quantification and tracking of MNPs@SiO
2
(RITC).
Results
The MNPs@SiO
2
(RITC) were observed to be highly internalized in RAW 264.7 cells, compared to the HEK293 and NIH3T3 cells undergoing single-particle analysis. In addition, MNPs@SiO
2
(RITC) were internalized within the nuclei of RAW 264.7 and HEK293 cells but were not detected in the nuclei of NIH3T3 cells. Moreover, because of the treatment of the MNPs@SiO
2
(RITC), more micronuclei were detected in RAW 264.7 cells than in other cells.
Conclusion
The sensitive and quantitative evaluations of MNPs@SiO
2
(RITC) at specific sites in three different cells using a combination of
d
STORM, transcriptomics, and molecular biology were performed. These findings highlight the quantitative differences in the uptake efficiency of MNPs@SiO
2
(RITC) and ultra-sensitivity, varying according to the cell types as ascertained by subdiffraction-limit super-resolution microscopy.
Graphical Abstract
Journal Article
Amplifying STING activation by cyclic dinucleotide–manganese particles for local and systemic cancer metalloimmunotherapy
by
Park, Kyung Soo
,
Nam, Jutaek
,
Moon, James J.
in
631/61/350/354
,
631/61/54/152
,
639/925/352/2733
2021
Nutritional metal ions play critical roles in many important immune processes. Hence, the effective modulation of metal ions may open up new forms of immunotherapy, termed as metalloimmunotherapy. Here, we demonstrate a prototype of cancer metalloimmunotherapy using cyclic dinucleotide (CDN) stimulator of interferon genes (STING) agonists and Mn
2+
. We screened various metal ions and discovered specific metal ions augmented STING agonist activity, wherein Mn
2+
promoted a 12- to 77-fold potentiation effect across the prevalent human STING haplotypes. Notably, Mn
2+
coordinated with CDN STING agonists to self-assemble into a nanoparticle (CDN–Mn
2+
particle, CMP) that effectively delivered STING agonists to immune cells. The CMP, administered either by local intratumoural or systemic intravenous injection, initiated robust anti-tumour immunity, achieving remarkable therapeutic efficacy with minute doses of STING agonists in multiple murine tumour models. Overall, the CMP offers a new platform for local and systemic cancer treatments, and this work underscores the great potential of coordination nanomedicine for metalloimmunotherapy.
The stimulation of interferon genes (STING) pathway with STING agonists such as cyclic dinucleotides (CDNs) has emerged as a promising immunotherapeutic approach. Here, the authors show that Mn
2+
can amplify the STING-promoted anti-tumour immune response in challenging murine tumour models by coordinating with CDNs and self-assembling into nanoparticles that can be delivered locally and systemically.
Journal Article
Oral–gut microbiome axis in a Korean cohort with inflammatory bowel disease and ankylosing spondylitis (INTEGRATE): a prospective and observational study protocol
2025
IntroductionThe global burden of chronic immune-mediated inflammatory diseases (IMIDs) is increasing, and rising prevalence rates significantly affect socioeconomic factors and quality of life. Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), along with ankylosing spondylitis (AS), are prominent chronic IMIDs that share overlapping pathophysiological mechanisms. Recent research has highlighted the importance of the gut microbiota in the pathogenesis of these diseases, suggesting that shared microbial dysbiosis may contribute to their development. Comprehensive research focusing on the gut and oral microbial characteristics and environmental factors is essential to elucidate the fundamental pathophysiology and develop personalised management strategies for IBD and AS. In-depth analyses and insights based on multiomics approaches are required to achieve these objectives.Methods and analysisThis protocol describes a nationwide prospective observational study of CD, UC and AS in a Korean population. Over 5 years, we aim to recruit at least 900 patients with IBD and 200 first-degree relatives (FDRs), 500 patients with AS and 200 of their FDRs, and 2244 healthy controls. We will systematically collect clinical data and biological samples, including saliva, stool, blood and tissue biopsies, for integrative multiomics analyses focusing primarily on the microbiome. Highly advanced full-length 16S ribosomal RNA gene sequencing and shotgun metagenomics will be used to characterise the microbial composition of saliva and stool samples. Quantitative microbiome profiling will be used to address the pathological, physiological and ecological differences between microbial groups that may be masked by their relative abundance. Metabolomic analyses will be conducted on saliva, stool and plasma samples to assess functional metabolic profiles. Culturomics will be used to isolate, identify and characterise the diversity of microbial species, including rare or previously unrecognised species, to provide a comprehensive understanding of the microbiota associated with these diseases.Ethics and disseminationEthical approval was obtained from the Ethics Committee of Kyung Hee University Hospital, Hanyang University Hospital, Kangbuk Samsung Hospital, Yeungnam University Hospital, Kyungpook National University Hospital, Chonnam National University Hospital, Wonkwang University Hospital, Catholic University Daejeon St. Mary’s Hospital, Soon Chun Hyang University Hospital Cheonan, Chung-Ang University Hospital, Inje University Haeundae Paik Hospital, Dankook University Hospital, Hanyang University Guri Hospital, Kyung Hee University Hospital at Gangdong, Chung-Ang University Gwangmyeong Hospital and Keimyung University Dongsan Hospital. Our research team will provide detailed information about the study, including an information sheet explaining its aims and procedures, prior to enrolment. Prospective participants will be informed that they have the right to withdraw from the study at any time, without penalty. Participants will be assured of the anonymity and confidentiality of any data they provide throughout the study, using participant numbers and the storage of sensitive data in locked cabinets. Participants will be enrolled in the study only after providing written informed consent to the research staff. The results of this study will be disseminated to healthcare and academic professionals through publications in peer-reviewed journals and presentations at international conferences.Trial registration numberThis prospective observational study is registered at ClinicalTrials.gov ((ID: NCT06124833, data first posted: 9 November 2023); (ID: NCT06076083, data first posted: 21 November 2023) and (ID: NCT06183697, data first posted: 27 December 2023)).
Journal Article
Zebrafish EEG predicts the efficacy of antiepileptic drugs
2022
Background: Pharmacological evaluation of antiepileptic drugs (AEDs) using mammalian animals takes long time and is expensive. The zebrafish is a species commonly used to study brain functions, neurological diseases, and drug toxicity, and attracts more attention as an alternative animal model to substitute or supplement mammalian animals in drug development. Electroencephalogram (EEG) is a key indicator for diagnosing brain diseases such as epilepsy, by directly measuring the brain activity. We propose a novel method for pharmacological evaluation of AEDs based on EEG from adult zebrafish, which allows researchers to select more clinically valuable drugs at the early stage of AED screening. Methods: To evaluate the efficacy of AEDs, zebrafish EEG signals were measured after administering six AEDs (valproate acid, gabapentin, ethosuximide, oxcarbazepine, tiagabine, and topiramate) at various doses to pentylenetetrazol (PTZ)-induced seizure models. The change in seizure activity was investigated according to doses. The antiepileptic effect was determined by observing a significant decrease in at least one out of three indicators of the number, total duration, and mean duration of ictal events. Results: Using EEG signals from adult zebrafish, antiepileptic effects were observed with all six AEDs. Among them, antiepileptic effects depending on dose were confirmed with valproate acid, gabapentin, ethosuximide, and tiagabine. Moreover, the 50% effective doses (ED50) of valproate acid and tiagabine were determined based on zebrafish EEG for the first time, indicating that the quantitative inter-species comparison of the AED efficacy is possible between zebrafish and mammals such as rodents. Significance: The results show that zebrafish can be used to effectively and quantitatively evaluate the efficacy of AEDs based on EEG, the same method to evaluate antiepileptic effects in mammals, suggesting that the proposed method can contribute in reducing the cost and duration of search for AEDs and thus accelerate the drug development cycles.
Journal Article
Reversion of Gut Microbiota during the Recovery Phase in Patients with Asymptomatic or Mild COVID-19: Longitudinal Study
2021
Patients with COVID-19 have been reported to experience gastrointestinal symptoms as well as respiratory symptoms, but the effects of COVID-19 on the gut microbiota are poorly understood. We explored gut microbiome profiles associated with the respiratory infection of SARS-CoV-2 during the recovery phase in patients with asymptomatic or mild COVID-19. A longitudinal analysis was performed using the same patients to determine whether the gut microbiota changed after recovery from COVID-19. We applied 16S rRNA amplicon sequencing to analyze two paired fecal samples from 12 patients with asymptomatic or mild COVID-19. Fecal samples were selected at two time points: during SARS-CoV-2 infection (infected state) and after negative conversion of the viral RNA (recovered state). We also compared the microbiome data with those from 36 healthy controls. Microbial evenness of the recovered state was significantly increased compared with the infected state. SARS-CoV-2 infection induced the depletion of Bacteroidetes, while an abundance was observed with a tendency to rapidly reverse in the recovered state. The Firmicutes/Bacteroidetes ratio in the infected state was markedly higher than that in the recovered state. Gut dysbiosis was observed after infection even in patients with asymptomatic or mild COVID-19, while the composition of the gut microbiota was recovered after negative conversion of SARS-CoV-2 RNA. Modifying intestinal microbes in response to COVID-19 might be a useful therapeutic alternative.
Journal Article