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"Kim, Sung Hee"
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Human gastric microbiota transplantation recapitulates premalignant lesions in germ-free mice
2022
ObjectiveGastric cancer (GC) is a leading cause of cancer-related mortality. Although microbes besides Helicobacter pylori may also contribute to gastric carcinogenesis, wild-type germ-free (GF) mouse models investigating the role of human gastric microbiota in the process are not yet available. We aimed to evaluate the histopathological features of GF mouse stomachs transplanted with gastric microbiota from patients with different gastric disease states and their relationships with the microbiota.DesignMicrobiota profiles in corpus and antrum tissues and gastric fluid from 12 patients with gastric dysplasia or GC were analysed. Thereafter, biopsied corpus and antrum tissues and gastric fluid from patients (n=15 and n=12, respectively) with chronic superficial gastritis, intestinal metaplasia or GC were inoculated into 42 GF C57BL/6 mice. The gastric microbiota was analysed by amplicon sequencing. Histopathological features of mouse stomachs were analysed immunohistochemically at 1 month after inoculation. An independent set of an additional 15 GF mice was also analysed at 1 year.ResultsThe microbial community structures of patients with dysplasia or GC in the corpus and antrum were similar. The gastric microbiota from patients with intestinal metaplasia or GC selectively colonised the mouse stomachs and induced premalignant lesions: loss of parietal cells and increases in inflammation foci, in F4/80 and Ki-67 expression, and in CD44v9/GSII lectin expression. Marked dysplastic changes were noted at 1 year post inoculation.ConclusionMajor histopathological features of premalignant changes are reproducible in GF mice transplanted with gastric microbiota from patients with intestinal metaplasia or GC. Our results suggest that GF mice are useful for analysing the causality of associations reported in human gastric microbiome studies.
Journal Article
Protective effects of Lactobacillus plantarum strain against protein malnutrition-induced muscle atrophy and bone loss in juvenile mice
2025
Early-life malnutrition adversely affects nearly all organ systems, resulting in multiple physiological adaptations, including growth restriction and muscle and bone loss. Although there is growing evidence that probiotics effectively improve systemic growth under malnourished conditions in different animal models, our knowledge of the beneficial effects of probiotics on various organs is limited. Here, we show that Lactobacillus plantarum strain WJL (Lp WJL ) can mitigate skeletal muscle and bone loss in protein-malnourished juvenile mice. Mice on prenatal day 21 were fed a protein-malnourished (P-MAL) diet with or without Lp WJL supplementation for six weeks. Compared to mice on the P-MAL diet alone, Lp WJL supplementation significantly increased muscle mass and size, resulting in enhanced muscle strength and endurance capacity. Furthermore, Lp WJL supplementation induced the expression of the key growth factor IGF-1 while decreasing muscle atrophy markers such as Atrogin-1 and MuRF-1, indicating potential mechanisms by which protein malnutrition-induced muscle wasting is counteracted. Additionally, Lp WJL supplementation alleviated the reduction in cortical bone thickness and the deterioration of trabecular bone microstructure in the femur. Taken together, these results indicate that Lp WJL can protect against skeletal muscle atrophy and compromised bone microarchitecture caused by protein malnutrition, providing novel insights into the potential therapeutic applications of probiotics for treating malnutrition-related disorders.
Journal Article
A Systematic Review on Visualizations for Self-Generated Health Data for Daily Activities
2022
Due to the development of sensing technology people can easily track their health in various ways, and the interest in personal healthcare data is increasing. Individuals are interested in controlling their wellness, which requires self-awareness and an understanding of various health conditions. Self-generated health data are easily accessed through mobile devices, and data visualization is commonly used in applications. A systematic literature review was conducted to better understand the role of visualizations and learn how to develop effective ones. Thirteen papers were analyzed for types of data, characteristics of visualizations, and effectiveness for healthcare management. The papers were selected because they represented research on personal health data and visualization in a non-clinical setting, and included health data tracked in everyday life. This paper suggests six levels for categorizing the efficacy of visualizations that take into account cognitive and physical changes in users. Recommendations for future work on conducting evaluations are also identified. This work provides a foundation for personal healthcare data as more applications are developed for mobile and wearable devices.
Journal Article
Drosophila Microbiome Modulates Host Developmental and Metabolic Homeostasis via Insulin Signaling
by
Lee, Won-Jae
,
Shin, Seung Chul
,
Kim, Sung-Hee
in
Acetic acid
,
Acetobacter
,
Acetobacter - genetics
2011
The symbiotic microbiota profoundly affect many aspects of host physiology; however, the molecular mechanisms underlying host-microbe cross-talk are largely unknown. Here, we show that the pyrroloquinoline quinone-dependent alcohol dehydrogenase (PQQ-ADH) activity of a commensal bacterium, Acetobacter pomorum, modulates insulin/insulin-like growth factor signaling (IIS) in Drosophila to regulate host homeostatic programs controlling developmental rate, body size, energy metabolism, and intestinal stem cell activity. Germ-free animals monoassociated with PQQ-ADH mutant bacteria displayed severe deregulation of developmental and metabolic homeostasis. Importantly, these defects were reversed by enhancing host IIS or by supplementing the diet with acetic acid, the metabolic product of PQQ-ADH.
Journal Article
COVID-19 severity analysis for clinical decision support based on machine learning approach
2025
The COVID-19 pandemic has placed immense pressure on global healthcare systems, underscoring the urgent need for early and accurate prediction of disease severity to improve patient care and optimize resource allocation. Failure in ward allocation can lead to wasted hospital resources and inadequate treatment. This study analyzes data from 806 COVID-19 patients admitted to the emergency room of Chungbuk National University Hospital, Korea, between January 2021 and December 2022, to develop machine learning models that predict which patients should be prioritized for intensive care unit (ICU) placement based on initial clinical information. Additionally, two different severity criteria were considered based on actual ICU level interventions (Criterion I) and based on national policy definitions (Criterion II). Single models of logistic regression, random forest, support vector machine, light gradient boosting, and extreme gradient boosting, as well as ensemble learning models using voting classifiers, were used. The ensemble model achieved the best performance, with recall rates of 96.2% and 88.2% for each criterion, respectively. Key features such as glucose level, neutrophil count, high sensitivity C-reactive protein (hsCRP) level, and albumin level were identified, improving model interpretability. This study provides valuable insights for healthcare professionals to support effective early ward allocation and treatment strategies.
Journal Article
Anti-Inflammatory Effect of Chamaecyparis obtusa (Siebold & Zucc.) Endl. Leaf Essential Oil
by
Kim, Sung-Hee
,
Jang, Young-Ah
,
Kwon, Yong-Jin
in
anti-inflammatory
,
Anti-Inflammatory Agents - pharmacology
,
Bicyclic Monoterpenes
2024
Chamaecyparis obtusa (Siebold & Zucc.) Endl. (C. obtusa) belongs to the Cupressaceae family and is native to East Asian regions. Essential oils extracted from the leaves, bark, branches, and roots of C. obtusa have both aesthetic and medicinal properties and are thus widely used. However, detailed analyses of the active ingredients of C. obtusa extract are lacking. In this study, the sabinene content in the hydro-distillation of C. obtusa leaf essential oil (COD) was analyzed using GC-MS, and the anti-inflammatory effect of COD was compared with that of pure sabinene. Cell viability was evaluated by MTT assay, and nitric oxide (NO) production was measured using Griess reagent. Relative mRNA and protein levels were analyzed using RT-qPCR and western blot, and secreted cytokines were analyzed using a cytokine array kit. The results showed that both COD and sabinene inhibited the expression of inducible nitric oxide synthase (iNOS) and the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 in lipopolysaccharide (LPS)-induced RAW 264.7 cells. COD and sabinene also reduced the production of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, IL-27, IL-1 receptor antagonist (IL-1ra), and granulocyte-macrophage colony-stimulating factor (GM-CSF). The anti-inflammatory mechanisms of COD and sabinene partially overlap, as COD was shown to inhibit MAPKs and the JAK/STAT axis, and sabinene inhibited MAPKs, thereby preventing LPS-induced macrophage activation.
Journal Article
How Are Wearable Activity Trackers Adopted in Older Adults? Comparison between Subjective Adoption Attitudes and Physical Activity Performance
by
Ajisafe, Toyin
,
Kim, Sung-Hee
,
Xie, Junfei
in
Attitude surveys
,
Design specifications
,
Exercise
2020
Wearable activity trackers can motivate older adults to engage in the recommended daily amount of physical activity (PA). However, individuals may not maintain their use of the trackers over a longer period. To investigate the attitudes of activity tracker adoption and their effects on actual PA performance, we conducted a three-month study. We gave activity trackers to 16 older adults and assessed attitudes on activity tracker adoption through a survey during the study period. We extracted participants’ PA measures, step counts, and moderate and vigorous physical activity (MVPA) times. We observed significant differences in adoption attitudes during the three different periods (χ2(2, 48) = 6.27, p < 0.05), and PA measures followed similar decreasing patterns (F(83, 1357) = 12.56, 13.94, p < 0.00001). However, the Pearson correlation analysis (r = 0.268, p = 0.284) and a Bland–Altman plot indicated a bias between two PA measures. Positive attitudes at the initial stage did not persist through the study period, and both step counts and length of MVPA time showed waning patterns in the study period. The longitudinal results from both measures demonstrated the patterns of old adults’ long-term use and adoption. Considering the accuracy of the activity tracker and older adults’ athletic ability, MVPA times are more likely to be a reliable measure of older adults’ long-term use and successful adoption of activity trackers than step counts. The results support the development of better activity tracker design guidelines that would facilitate long-term adoption among older adults.
Journal Article
Renin-angiotensin system modulators and other risk factors in COVID-19 patients with hypertension: a Korean perspective
by
Kang, Minseok
,
Kim, Hee-Sung
,
Kang, Gilwon
in
Aged
,
Angiotensin
,
Angiotensin converting enzyme inhibitor (ACEI)
2021
Background
While hypertension is the most common comorbid condition in patients with coronavirus disease 2019 (COVID-19) in Korea, there is a lack of studies investigating risk factors in COVID-19 patients with hypertension in Korea. In this study, we aimed to examine the effects risk factors in hypertensive Korean COVID-19 patients.
Methods
We selected patients from the database of the project #OpenData4Covid19. This information was linked to their 3-year historical healthcare data. The severity of the disease was classified into five levels. We also clustered the levels into two grades.
Results
The risk factors associated with COVID-19 severity were old age, diabetes mellitus, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), malignancy, and renal replacement therapy. The use of angiotensin converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) both before and after a diagnosis of COVID-19 were not associated with COVID-19 severity. A multivariate analysis revealed that old age, male sex, diabetes mellitus, and renal replacement therapy were risk factors for severe COVID-19.
Conclusion
The results suggest that in hypertensive patients with COVID-19, older age, male sex, a diagnosis of diabetes mellitus, and renal replacement therapy were risk factors for a severe clinical course. In addition, the use of ARBs and ACEIs before or after COVID-19 infection did not affect a patient’s risk of contracting COVID-19 nor did it contribute to a worse prognosis for the disease. These results highlighted that precautions should be considered for hypertensive patients with those risk factors and do not support discontinuation of ARBs and ACEIs during COVID-19 pandemic.
Journal Article
Impacts of Visualizations on Decoy Effects
2021
The decoy effect is a well-known, intriguing decision-making bias that is often exploited by marketing practitioners to steer consumers towards a desired purchase outcome. It demonstrates that an inclusion of an alternative in the choice set can alter one’s preference among the other choices. Although this decoy effect has been universally observed in the real world and also studied by many economists and psychologists, little is known about how to mitigate the decoy effect and help consumers make informed decisions. In this study, we conducted two experiments: a quantitative experiment with crowdsourcing and a qualitative interview study—first, the crowdsourcing experiment to see if visual interfaces can help alleviate this cognitive bias. Four types of visualizations, one-sided bar chart, two-sided bar charts, scatterplots, and parallel-coordinate plots, were evaluated with four different types of scenarios. The results demonstrated that the two types of bar charts were effective in decreasing the decoy effect. Second, we conducted a semi-structured interview to gain a deeper understanding of the decision-making strategies while making a choice. We believe that the results have an implication on showing how visualizations can have an impact on the decision-making process in our everyday life.
Journal Article
Role of DUOX in gut inflammation: lessons from Drosophila model of gut-microbiota interactions
2014
It is well-known that certain bacterial species can colonize the gut epithelium and induce inflammation in the mucosa, whereas other species are either benign or beneficial to the host. Deregulation of the gut-microbe interactions may lead to a pathogenic condition in the host, such as chronic inflammation, tissue injuries, and even cancer. However, our current understanding of the molecular mechanisms that underlie gut-microbe homeostasis and pathogenesis remains limited. Recent studies have used Drosophila as a genetic model to provide novel insights into the causes and consequences of bacterial-induced colitis in the intestinal mucosa. The present review discusses the interactions that occur between gut-associated bacteria and host gut immunity, particularly the bacterial-induced intestinal dual oxidase (DUOX) system. Several lines of evidence showed that the bacterial-modulated DUOX system is involved in microbial clearance, intestinal epithelial cell renewal (ECR), redox-dependent modulation of signaling pathways, cross-linking of biomolecules, and discrimination between symbionts and pathogens. Further genetic studies on the Drosophila DUOX system and on gut-associated bacteria with a distinct ability to activate DUOX may provide critical information related to the homeostatic inflammation as well as etiology of chronic inflammatory diseases, which will enhance our understanding on the mucosal inflammatory diseases frequently observed in the microbe-contacting epithelia of humans.
Journal Article