1.The Critical Role of Intracellular Bacterial Communities in Uncomplicated Recurrent Urinary Cystitis: A Comprehensive Review of Detection Methods and Diagnostic Potential
Yeonjoo KWAK ; Hyeong Gon KIM ; Jaekwon SEOK ; Sehwan KIM ; Eun-Mee KIM ; Aram KIM
International Neurourology Journal 2024;28(1):4-10
Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and are particularly prevalent in women. Recurrent UTIs significantly diminish quality of life due to their symptoms and frequent relapses. Patients often experience immediate relapse following slightly strenuous activities or intense psychological stress. In this review, we explore why infections persist despite the advent of various treatments and suggest strategies to manage recurrent cystitis by targeting the mechanisms of adhesion and infection. Vitamin D levels and the expression of neutrophil gelatinase-associated lipocalin are linked to the recurrence of UTIs. During a UTI, bacteria employ adhesins to invade the urinary tract, adhere to urothelial cells, and then penetrate these cells, where they rapidly multiply to establish intracellular bacterial communities. Bacteria can also form quiescent intracellular reservoirs that escape immune responses and antibiotic treatments, leading to recurrence under certain conditions. The surface proteins of bacteria and D-mannose are crucial in the adhesion of bacteria to the urothelium. Understanding these processes provides valuable insights into potential therapeutic approaches that focus on preventing bacterial attachment and cluster formation. By disrupting the ability of bacteria to adhere to and form clusters on cells, we can better manage recurrent UTIs and improve patient outcomes.
2.Advancing Patient Care: Innovative Use of Near-Infrared Spectroscopy for Monitoring Urine Volume in Neurogenic Bladder
Byeong-Il KANG ; Aram KIM ; Sehwan KIM
International Neurourology Journal 2023;27(Suppl 1):S27-33
Purpose:
Current guidelines recommend clean intermittent catheterization (CIC) at regular time intervals for patients with spinal cord injuries; however, many patients experience difficulties. Performing time-based CIC outside the home is a significant burden for patients. In this study, we aimed to overcome the limitations of the current guidelines by developing a digital device to monitor bladder urine volume in real-time.
Methods:
The optode sensor is a near-infrared spectroscopy (NIRS)-based wearable device intended to be attached to the skin of the lower abdomen where the bladder is located. The sensor’s primary function is to detect changes in urine volume within the bladder. An in vitro study was conducted using a bladder phantom that mimicked the optical properties of the lower abdomen. To validate the data in the human body at the proof-of-concept level, one volunteer attached the device to the lower abdomen to measure the light intensity between the first voiding and immediately before the second voiding.
Results:
The degree of attenuation at the maximum test volume was equivalent across experiments, and the optode sensor with multiplex measurements demonstrated robust performance for patient diversity. Moreover, the symmetric feature of the matrix was deemed a potential parameter for identifying the accuracy of sensor localization in a deep-learning model. The validated feasibility of the sensor showed almost the same results as an ultrasound scanner, which is routinely used in the clinical field.
Conclusions
The optode sensor of the NIRS-based wearable device can measure the urine volume in the bladder in real-time.
3.Hybrid Bladder Phantom to Validate Next-Generation Optical Wearables for Neurogenic Bladder Volume Monitoring
Kelsey J. TU ; Jesse H. LAM ; Byeong-Il KANG ; Aram KIM ; Sehwan KIM
International Neurourology Journal 2023;27(Suppl 2):S82-90
Purpose:
The development of optics-based wearables for bladder volume monitoring has emerged as a significant topic in recent years. Given the innovative nature of this technology, there is currently no bladder phantom available to effectively validate these devices against more established gold standards, such as ultrasound. In this study, we showcase and demonstrate the performance of our hybrid bladder phantom by using an optical device and making comparisons with ultrasound.
Methods:
A series of validation tests, including phantom repeatability, ultrasound scanning, and an optical test, were performed. A near-infrared optical device was utilized to conduct diffuse optical spectroscopy (DOS). Machine learning models were employed to construct predictive models of volume using optical signals.
Results:
The size and position of an embedded balloon, serving as an analog for the bladder, were shown to be consistent when infused with 100 mL to 350 mL of water during repeatability testing. For DOS data, we present 7 types of machine learningbased models based on different optical signals. The 2 best-performing models demonstrated an average absolute volume error ranging from 12.7 mL to 19.0 mL.
Conclusions
In this study, we introduced a hybrid bladder phantom designed for the validation of near-infrared spectroscopy-based bladder monitoring devices in comparison with ultrasound techniques. By offering a reproducible and robust validation tool, we aim to support the advancement of next-generation optical wearables for bladder volume monitoring.
4.A Pilot Study on the Development and the Effect of a Cognitive-Behavioral Intervention for Undergraduates at Mental Health High Risk
Jihye KIM ; Sun-Hee AN ; You Jin PARK ; Sehwan PARK ; Kyungun JHUNG
Korean Journal of Psychosomatic Medicine 2022;30(1):30-37
Objectives:
: The purpose of this study was to develop a cognitive-behavioral intervention for college students at high risk for mental health and to investigate its effect on mental health outcomes.
Methods:
: The program was developed to reduce depressive symptoms and adverse outcomes while promoting resilience and positive effects. It consisted of eight sessions in a small group format for eight weeks. Thirty subjects at high risk for mental health participated in the program. Outcomes on the depressive symptoms, resilience, satisfaction with life, negative affect, and positive affect were evaluated at pre-and post-intervention.
Results:
: Depressive symptom scores reduced significantly post-intervention compared to pre-intervention (t=3.51, p=0.002). Resilience scores (t=-3.65, p=0.001) and satisfaction with life scores (t=-3.00, p=0.006) increased after intervention than pre-intervention. Positive affect scores decreased post-intervention (t=2.28, p=0.031). There was no significant difference between pre-and post-intervention negative affect scores (t=-0.94, p=0.356).
Conclusions
: Present study demonstrated that group-based cognitive-behavioral intervention could be helpful for college students at high risk for mental health to reduce mental health symptoms and improve healthy protective factors.
5.Preventive effect of biodegradable stents on biliary stricture and fibrosis after biliary anastomosis in a porcine model
Chang-Il KWON ; Sung Hoon CHOI ; Kyu Seok KIM ; Jong Pil MOON ; Sehwan PARK ; Jinkyung JEON ; Gwangil KIM ; Jae Young JANG ; Min Je SUNG ; Kwang Hyun KO ; Jun Sik SON
Annals of Surgical Treatment and Research 2022;102(2):90-99
Purpose:
The current drain tubes for preventing surgically biliary anastomotic stricture are not naturally and easily removed. If a drain tube using biodegradable material is easily available and the degradation time of the tube is well controlled, surgical anastomotic stricture and fibrosis could be prevented. The aim of this animal study was to evaluate the preventive effect of novel biodegradable stents (BS) on biliary stricture and fibrosis after duct-to-duct (DD) biliary anastomosis.
Methods:
Ten mini-pigs were allocated to the control group (n = 5) and or the stent group (n = 5). The common bile duct was exposed through surgical laparotomy and then resected transversely. In the stent group, a 4-mm or 6-mm polydioxanone/ magnesium sheath-core BS was inserted according to the width of the bile duct, followed by DD biliary anastomosis. In the control group, DD biliary anastomosis was performed without BS insertion.
Results:
In the stent group, stents were observed without deformity for up to 4 weeks in all animals. Eight weeks later, histopathologic examination revealed that the common bile duct of the anastomosis site was relatively narrower in circumference in the control group compared to the stent group. The degree of fibrosis in the control group was more marked than in the stent group (3.84 mm vs. 0.68 mm, respectively; P < 0.05).
Conclusion
Our study showed that novel BS maintained their original shape and radial force for an adequate time and then disappeared without adverse events. The BS could prevent postoperative complications and strictures after DD biliary anastomosis.
6.Pattern Analysis of Laser Fiber Degradation According to the Laser Setting: In Vitro Study of the DoubleFiring Phenomenon
Gyoohwan JUNG ; Seung Min LEE ; Sang Won SO ; Sehwan KIM ; Seong Chan KIM ; Ohbin KWON ; Hyunjae SONG ; Min Joo CHOI ; Sung Yong CHO
Journal of Korean Medical Science 2022;37(38):e280-
Background:
It is essential to understand the mechanism of the various causes of laser fiber damage and an ideal method of reducing endoscope damage induced by laser emission in multiple sites. This study classified the different patterns of laser fiber degradation according to laser settings and analyzed the role of cavitation bubbles to find a desirable way of minimizing endoscope damage.
Methods:
A total of 118 laser fibers were analyzed after 1-,3-, and 5-min laser emission to artificial stones under the settings of 1 J-10 Hz, 1 J-20 Hz, 1 J-30 Hz, and 2 J-10 Hz. Every 3 cm from the fiber tip was marked and examined with a digital microscope and a high-speed camera. The images of the fibers and the movement of cavitation bubbles were taken with a distance of 1 to 5 mm from the gel.
Results:
Seven types of fiber damage (charring, limited and extensive peeled-off, bumpy, whitish plaque, crack, and break-off ) coincided during laser emission. Damages rapidly increased with emission time > 3 minutes regardless of the laser settings. The damaged lengths covered 5 mm on average, and the fibers at 5-min emission were significantly shorter than others. The fiber durability of 1J-10Hz setting was better than other settings after 3-min laser emission. Backward movement of the cavitation bubbles was found at the 1-mm distance from the gel, and the damaged lengths were longer than the diameters of the cavitation bubbles because of their proximal movement.
Conclusion
The damage patterns of the laser fiber tips were classified into seven types. The heat damage around the surface of the laser fiber can be increased according to the highenergy or high-frequency laser setting, a short distance to the stone, a short distance from the tips of flexible ureteroscopes, no cutting laser fiber procedures, and the inappropriate use of irrigation fluid or laser fiber jacket.
7.What is the Cause of Recurrent Urinary Tract Infection? Contemporary Microscopic Concepts of Pathophysiology
Aram KIM ; Jaehak AHN ; Woo Suk CHOI ; Hyoung Keun PARK ; Sehwan KIM ; Sung Hyun PAICK ; Hyeong Gon KIM
International Neurourology Journal 2021;25(3):192-201
Urinary tract infections (UTIs) are the most common infectious disease and are mainly caused by Escherichia coli. In this review, we introduce the current concept of recurrent UTI (rUTI) based on recent research dealing with pathophysiology of the disease. Although urine is considered sterile, recent studies dealing with microbiome have proposed different ideas. UTIs have typically been considered as extracellular infections, but recently, uropathogenic Escherichia coli (UPEC) has been shown to bind and replicate in the urothelium to make intracellular bacterial communities. Binding UPECs might proceed in many ways including extracellular expulsion for clearance or survival and quiescent intracellular reservoirs that can cause rUTI. Moreover, it is also suggested that other important factors, such as lipopolysaccharide and multimicrobial infection, can be the cause of rUTI. This review article reveals a key mechanism of recurrence and discusses what makes a pathway of resolution or recurrence in a host after initial infection.
8.What is the Cause of Recurrent Urinary Tract Infection? Contemporary Microscopic Concepts of Pathophysiology
Aram KIM ; Jaehak AHN ; Woo Suk CHOI ; Hyoung Keun PARK ; Sehwan KIM ; Sung Hyun PAICK ; Hyeong Gon KIM
International Neurourology Journal 2021;25(3):192-201
Urinary tract infections (UTIs) are the most common infectious disease and are mainly caused by Escherichia coli. In this review, we introduce the current concept of recurrent UTI (rUTI) based on recent research dealing with pathophysiology of the disease. Although urine is considered sterile, recent studies dealing with microbiome have proposed different ideas. UTIs have typically been considered as extracellular infections, but recently, uropathogenic Escherichia coli (UPEC) has been shown to bind and replicate in the urothelium to make intracellular bacterial communities. Binding UPECs might proceed in many ways including extracellular expulsion for clearance or survival and quiescent intracellular reservoirs that can cause rUTI. Moreover, it is also suggested that other important factors, such as lipopolysaccharide and multimicrobial infection, can be the cause of rUTI. This review article reveals a key mechanism of recurrence and discusses what makes a pathway of resolution or recurrence in a host after initial infection.
9.Accuracy and clinical feasibility of 3D‑myocardial thickness map measured by cardiac computed tomogram
Oh‑Seok KWON ; Jisu LEE ; Sehwan LIM ; Je‑Wook PARK ; Hee‑Jin HAN ; So‑Hyun YANG ; Inseok HWANG ; Hee Tae YU ; Tae‑Hoon KIM ; Jae‑Sun UHM ; Boyoung JOUNG ; Moon‑Hyoung LEE ; Hui‑Nam PAK
International Journal of Arrhythmia 2020;21(3):e12-
Background:
Although myocardial thickness is an important variable for therapeutic catheter ablation of cardiac arrhythmias, quantification of wall thickness has been overlooked. We developed a software (AMBER) that measures 3D-myocardial thickness using a cardiac computed tomogram (CT) image, verified its accuracy, and tested its clinical feasibility.
Methods:
We generated 3D-thickness maps by calculating wall thickness (WT) from the CT images of 120 patients’ hearts and a 3D-phantom model (PhM). The initial vector field of the Laplace equation was oriented to calculate WT with the field lines derived from the 3D mesh. We demonstrate the robustness of the Laplace WT algorithm by comparing with the real thickness of 3D-PhM, echocardiographically measured left ventricular (LV) WT, and regional left atrial (LA) WT reported from previous studies. We conducted a pilot case of catheter ablation for atrial fibrillation (AF) utilizing real-time LAWT map-guided radiofrequency (RF) energy titration.
Results:
AMBER 3D-WT had excellent correlations with the real thickness of the PhM (R = 0.968, p < 0.001) and echocardiographically measured LVWT in 10 patients (R = 0.656, p = 0.007). AMBER 3D-LAWT (n = 120) showed a relatively good match with 12 previously reported regional LAWT. We successfully conducted pilot AF ablation utilizing AMBER 3D-LAWT map-guided real-time RF energy titration.
Conclusion
We developed and verified an AMBER 3D-cardiac thickness map measured by cardiac CT images for LAWT and LVWT, and tested its feasibility for RF energy titration during clinical catheter ablation.
10.Current Overview of Surgical Options for Female Stress Urinary Incontinence
Aram KIM ; Sehwan KIM ; Hyeong Gon KIM
International Neurourology Journal 2020;24(3):222-230
Stress urinary incontinence (SUI) is a highly prevalent health condition that significantly impacts the quality of life. Traditional methods of treatment for SUI, such as pubovaginal sling and Burch colposuspension, have been replaced by the midurethral sling because of its high efficacy, low complication and morbidity rates, and short learning curve. Although multiple behavioral and operative treatments exist, midurethral slings are the gold standard for the treatment of SUI in women. However, several reports have raised concerns about complications caused by the synthetic mesh used in midurethral slings. Therefore, surgical treatment for SUI in women must be chosen with care, taking into account potential complications. Herein, we review the current safety issues pertaining to the use of meshes, the efficacy of traditional surgeries, old and new midurethral slings, and recent data comparing the efficacy and safety of different surgical options. This review is aimed at developing practical guidelines for choosing surgical options for women with SUI.

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