4.Development of colonic stent simulator using three-dimensional printing technique: a simulator development study in Korea
Hyundam GU ; Suyoung LEE ; Sol KIM ; Hye-Lim JANG ; Da-Woon CHOI ; Kyu Seok KIM ; Yu Ri SHIN ; Dae Young CHEUNG ; Bo-In LEE ; Jin Il KIM ; Han Hee LEE
Clinical Endoscopy 2024;57(6):790-797
Background/Aims:
Colonic stenting plays a vital role in the management of acute malignant colonic obstruction. The increasing use of self-expandable metal stents (SEMS) and the diverse challenges posed by colonic obstruction at various locations underscore the importance of effective training for colonic stent placement.
Methods:
All the components of the simulator were manufactured using silicone molding techniques in conjunction with three-dimensional (3D) printing. 3D images sourced from computed tomography scans and colonoscopy images were converted into a stereolithography format. Acrylonitrile butadiene styrene copolymers have been used in fused deposition modeling to produce moldings.
Results:
The simulator replicated the large intestine from the rectum to the cecum, mimicking the texture and shape of the human colon. It enables training for colonoscopy insertion, cecum intubation, loop reduction, and stenting within stenotic areas. Interchangeable stenotic modules for four sites (rectum, sigmoid colon, descending colon, and ascending colon) were easily assembled for training. These modules integrate tumor contours and blood vessel structures with a translucent center, allowing real-time visualization during stenting. Successful and repeatable demonstrations of stent insertion and expansion using the reusable SEMS were consistently achieved.
Conclusions
This innovative simulator offers a secure colonic stenting practice across various locations, potentially enhancing clinical outcomes by improving operator proficiency during actual procedures.
5.Early Prediction of Mortality for Septic Patients Visiting Emergency Room Based on Explainable Machine Learning: A Real-World Multicenter Study
Sang Won PARK ; Na Young YEO ; Seonguk KANG ; Taejun HA ; Tae-Hoon KIM ; DooHee LEE ; Dowon KIM ; Seheon CHOI ; Minkyu KIM ; DongHoon LEE ; DoHyeon KIM ; Woo Jin KIM ; Seung-Joon LEE ; Yeon-Jeong HEO ; Da Hye MOON ; Seon-Sook HAN ; Yoon KIM ; Hyun-Soo CHOI ; Dong Kyu OH ; Su Yeon LEE ; MiHyeon PARK ; Chae-Man LIM ; Jeongwon HEO ; On behalf of the Korean Sepsis Alliance (KSA) Investigators
Journal of Korean Medical Science 2024;39(5):e53-
Background:
Worldwide, sepsis is the leading cause of death in hospitals. If mortality rates in patients with sepsis can be predicted early, medical resources can be allocated efficiently. We constructed machine learning (ML) models to predict the mortality of patients with sepsis in a hospital emergency department.
Methods:
This study prospectively collected nationwide data from an ongoing multicenter cohort of patients with sepsis identified in the emergency department. Patients were enrolled from 19 hospitals between September 2019 and December 2020. For acquired data from 3,657 survivors and 1,455 deaths, six ML models (logistic regression, support vector machine, random forest, extreme gradient boosting [XGBoost], light gradient boosting machine, and categorical boosting [CatBoost]) were constructed using fivefold cross-validation to predict mortality. Through these models, 44 clinical variables measured on the day of admission were compared with six sequential organ failure assessment (SOFA) components (PaO 2 /FIO 2 [PF], platelets (PLT), bilirubin, cardiovascular, Glasgow Coma Scale score, and creatinine).The confidence interval (CI) was obtained by performing 10,000 repeated measurements via random sampling of the test dataset. All results were explained and interpreted using Shapley’s additive explanations (SHAP).
Results:
Of the 5,112 participants, CatBoost exhibited the highest area under the curve (AUC) of 0.800 (95% CI, 0.756–0.840) using clinical variables. Using the SOFA components for the same patient, XGBoost exhibited the highest AUC of 0.678 (95% CI, 0.626–0.730). As interpreted by SHAP, albumin, lactate, blood urea nitrogen, and international normalization ratio were determined to significantly affect the results. Additionally, PF and PLTs in the SOFA component significantly influenced the prediction results.
Conclusion
Newly established ML-based models achieved good prediction of mortality in patients with sepsis. Using several clinical variables acquired at the baseline can provide more accurate results for early predictions than using SOFA components. Additionally, the impact of each variable was identified.
6.Efficacy and Safety of Nasolabial Fold Correction Using Collagen-Stimulating Filler:A Systematic Review and Meta-Analysis
Chang Yong KIM ; Ji Won LIM ; Jae Young SUNG ; Young Ah CHO ; Yang Won LEE ; Yong Beom CHOE ; Da-Ae YU
Korean Journal of Dermatology 2024;62(5):269-278
Background:
Nasolabial folds (NLFs) constitute a pivotal aspect of facial aesthetics and are the primary focal points in facial rejuvenation procedures. Collagen-stimulating fillers have gained popularity due to their long-lasting effects and biocompatibility.
Objective:
This study aimed to comprehensively evaluate the therapeutic efficacy and safety profiles of collagenstimulating fillers for NLF correction.
Methods:
A thorough search of the databases including PubMed, Embase, and Cochrane was performed. Randomized controlled trials published between 2000 and 2023 on the treatment outcomes of collagen-stimulating fillers for NLFs were included. A systematic review and meta-analysis were conducted using the Wrinkle Severity Rating Scale (WSRS), Global Aesthetic Improvement Scale (GAIS), and adverse events.
Results:
Among the 144 pertinent studies, nine met the inclusion criteria, including 299 participants for polycaprolactone (PCL), 291 for poly L-lactic acid (PLLA), and 382 for calcium hydroxylapatite (CaHA). PCL showed significantly higher improvement in GAIS (risk ratio [RR], 3.14; 95% confidence interval [CI], 2.29∼4.30; p<0.001) and WSRS (mean difference, 0.71; 95% CI, 0.36∼1.06; p<0.001) at a 12-month interval compared with hyaluronic acid (HA). CaHA showed marked 12-month GAIS improvement versus HA (RR, 1.51; 95% CI, 1.21∼1.88; p<0.001). PLLA exhibited superior wrinkle improvement compared with HA at week 24, especially in individuals under 52 years of age. No severe complications occurred.
Conclusion
Collagen-stimulating fillers have the potential to be safe, effective, and long-lasting options for NLF correction. Nevertheless, due to the limited data and heterogeneity among the included studies, cautious interpretation is required. Further high-quality clinical trials are required to validate these findings.
7.Categorization of Meibomian Gland Dysfunction Using Lipid Layer Thickness and Meibomian Gland Dropout in Dry Eye Patients: A Retrospective Study
Phil Kyu LEE ; Jae Lim CHUNG ; Da Ran KIM ; Young Chae YOON ; SoonWon YANG ; Woong-Joo WHANG ; Yong-Soo BYUN ; HyungBin HWANG ; Kyung Sun NA ; HyunSoo LEE ; So Hyang CHUNG ; Eun Chul KIM ; YangKyung CHO ; Hyun Seung KIM ; Ho Sik HWANG
Korean Journal of Ophthalmology 2024;38(1):64-70
Purpose:
In the present study, we determined the prevalence of obstructive meibomian gland dysfunction (MGD), hyposecretory MGD, grossly normal MG, and hypersecretory MGD in patients with dry eye syndrome using lipid layer thickness (LLT) and MG dropout.
Methods:
Eighty-eight patients with dry eye syndrome were included in the study. Patients were categorized into four groups according to the LLT and weighted total meiboscore. The proportion of patients in each group was calculated. The age, sex, Ocular Surface Disease Index, LLT, Schirmer, tear film breakup time, cornea stain, weighted total meiboscore, expressibility, and quality of meibum were compared between the four groups.
Results:
Fifteen eyes (17.0%) had obstructive MGD, two eyes (2.3%) had hyposecretory MGD, 40 eyes (45.5%) had grossly normal MG, and 17 eyes (19.3%) had hypersecretory MGD. The obstructive MGD group was younger than the grossly normal MG group. In obstructive MGD, the ratio of men to women was higher than that of the other groups. However, Ocular Surface Disease Index, Schirmer, tear film breakup time, and corneal stain did not show statistically significant differences between the four groups. The meibum expressibility of the hyposecretoy MGD group was worse than those of the other groups. The meibum expressibility of the hyposecretoy MGD group was poor than those of the obstructive and hypersecretory MGD group.
Conclusions
This categorization was expected to help determine the best treatment method for dry eye syndrome, according to the MG status.
8.Mucosal Immunity Related to CD8+T Lymphocytes in Children with Helicobacter pylori Gastritis
Da Hee YANG ; Ha Young LEE ; Woohyuk CHOI ; Chang-Lim HYUN ; Ki Soo KANG
Pediatric Gastroenterology, Hepatology & Nutrition 2024;27(1):26-36
Purpose:
We investigated the role of CD8+ T cells as host immune factors in pediatric patients with Helicobacter pylori gastritis.
Methods:
Gastric mucosal tissue and blood samples were collected from 39 children, including 11 children with H. pylori infection and 28 children as controls. Anti-CD8 and anti-T-bet antibodies were used for immunohistochemistry of the gastric mucosa. For the cell surface and intracellular staining, peripheral blood mononuclear cells were stained with anti-IL7Rα, anti-CX3CR1, anti-CD8, anti-T-bet, and anti-IFN-γ antibodies. Cytokines of sera such as tumor necrosis factor alpha (TNF-α) and CX3CL1 were analyzed using enzyme- linked immunosorbent assay (ELISA).
Results:
In the immunohistochemistry of gastric mucosa, the frequency of CD8+ and T-bet+ T cells cells was higher in the H. pylori-positive group than in the control group (26.9± 7.8% vs. 16.9±3.3%, p<0.001; 5.0±2.5% vs. 2.2±0.7%, p=0.001). Between the control and H. pylori-positive groups, the frequency of IL-7RαlowCX3CR1+ CD8+ and T-bet+ INF-γ+ CD8+ T cells were not significantly different between surface and intracellular staining, respectively (40.4±24.0% vs. 38.2±17.8%, p=0.914; 40.4±24.0% vs. 38.2±17.8%, p=0.914). In the ELISA, no significant differences in TNF-α and CX3CL1 concentrations were observed between the control and H. pylori-positive groups (34.3±12.1 pg/mL vs. 47.0±22.6 pg/mL, p=0.114/0.5± 0.1 pg/mL vs. 0.5±0.1 pg/mL, p=0.188).
Conclusion
CD8+ T and Th1 cells, which secrete IFN-γ, might play important roles in the mucosal immunity of the stomach in children with H. pylori infection.
9.Adherence of PARP inhibitor for frontline maintenance therapy in primary epithelial ovarian cancer:a cross-sectional survey
Ji Hyun KIM ; Yumi LEE ; Da-Young KIM ; Sinae KIM ; Sang-Soo SEO ; Sokbom KANG ; Sang-Yoon PARK ; Myong Cheol LIM
Journal of Gynecologic Oncology 2024;35(1):e3-
Objective:
To identify the adherence rate to poly (ADP-ribose) polymerase (PARP) inhibitors and identify factors contributing to the deterioration of adherence at our institution.
Methods:
The adherence rate to PARP inhibitors was calculated using self-reported Adherence to Refills and Medications Scale questionnaires from a cross-sectional survey. Multivariable logistic regression analysis was performed to identify the factors that affected adherence.
Results:
Of the 131 respondents, 32 (24.4%) showed non-adherence to PARP inhibitors.In the multivariable logistic regression analysis, unemployed or retired status (odds ratio [OR]=4.878; 95% confidence interval [CI]=1.528–15.572; p=0.008), patients receiving niraparib (OR=3.387; 95% CI=1.283–8.940; p=0.014), and a lower score on the quality-oflife assessment (EORTC-QLQ-OV28), which reflects a better quality of life (QOC) with a lower symptom burden (OR=1.056; 95% CI=1.027–1.086; p<0.001) were associated with high adherence to PARP inhibitors.
Conclusion
Approximately one-fourth of patients with ovarian cancer are non-adherent to PARP inhibitors as maintenance treatment for newly diagnosed advanced ovarian cancer. The occupational status, type of PARP inhibitor, and QOC may affect adherence to PARP inhibitors.
10.Development of colonic stent simulator using three-dimensional printing technique: a simulator development study in Korea
Hyundam GU ; Suyoung LEE ; Sol KIM ; Hye-Lim JANG ; Da-Woon CHOI ; Kyu Seok KIM ; Yu Ri SHIN ; Dae Young CHEUNG ; Bo-In LEE ; Jin Il KIM ; Han Hee LEE
Clinical Endoscopy 2024;57(6):790-797
Background/Aims:
Colonic stenting plays a vital role in the management of acute malignant colonic obstruction. The increasing use of self-expandable metal stents (SEMS) and the diverse challenges posed by colonic obstruction at various locations underscore the importance of effective training for colonic stent placement.
Methods:
All the components of the simulator were manufactured using silicone molding techniques in conjunction with three-dimensional (3D) printing. 3D images sourced from computed tomography scans and colonoscopy images were converted into a stereolithography format. Acrylonitrile butadiene styrene copolymers have been used in fused deposition modeling to produce moldings.
Results:
The simulator replicated the large intestine from the rectum to the cecum, mimicking the texture and shape of the human colon. It enables training for colonoscopy insertion, cecum intubation, loop reduction, and stenting within stenotic areas. Interchangeable stenotic modules for four sites (rectum, sigmoid colon, descending colon, and ascending colon) were easily assembled for training. These modules integrate tumor contours and blood vessel structures with a translucent center, allowing real-time visualization during stenting. Successful and repeatable demonstrations of stent insertion and expansion using the reusable SEMS were consistently achieved.
Conclusions
This innovative simulator offers a secure colonic stenting practice across various locations, potentially enhancing clinical outcomes by improving operator proficiency during actual procedures.

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