Histologic improvement predicts endoscopic remission in patients with ulcerative colitis.

Limited research has been performed to determine if histologic improvement serves as a prognosticator for endoscopic remission, a key therapeutic target for ulcerative colitis (UC). The primary aim of the study was to evaluate if histological activity could predict endoscopic remission in UC patients with Mayo endoscopic subscores (MES) of 0 or 1. In addition, we compared the clinical outcomes between histologic improvement group and active group. This research encompassed 492 individuals with UC with MES of 0 or 1, who underwent histological assessment as per the established protocol of Samsung Medical Center between January 2018 and December 2020. Participants were categorized into two cohorts based on the degree of histological activity: those showing histologic improvement and those with ongoing histologic activity. The endoscopic activity was assessed during follow-up, and the primary outcome was endoscopic remission according to histologic activity. Out of the total participants, endoscopic activity was scrutinized in 435 patients during the colonoscopic follow-up and in 146 during the subsequent one. The histologic improvement group at the index colonoscopy was more likely achieve endoscopic remission than the histologic active group. Clinical relapse was more likely in the histologic active group than in the histologic improvement group.

Cardiac ultrasound simulation for autonomous ultrasound navigation.

Introduction: Ultrasound is well-established as an imaging modality for diagnostic and interventional purposes. However, the image quality varies with operator skills as acquiring and interpreting ultrasound images requires extensive training due to the imaging artefacts, the range of acquisition parameters and the variability of patient anatomies. Automating the image acquisition task could improve acquisition reproducibility and quality but training such an algorithm requires large amounts of navigation data, not saved in routine examinations. Methods: We propose a method to generate large amounts of ultrasound images from other modalities and from arbitrary positions, such that this pipeline can later be used by learning algorithms for navigation. We present a novel simulation pipeline which uses segmentations from other modalities, an optimized volumetric data representation and GPU-accelerated Monte Carlo path tracing to generate view-dependent and patient-specific ultrasound images. Results: We extensively validate the correctness of our pipeline with a phantom experiment, where structures' sizes, contrast and speckle noise properties are assessed. Furthermore, we demonstrate its usability to train neural networks for navigation in an echocardiography view classification experiment by generating synthetic images from more than 1,000 patients. Networks pre-trained with our simulations achieve significantly superior performance in settings where large real datasets are not available, especially for under-represented classes. Discussion: The proposed approach allows for fast and accurate patient-specific ultrasound image generation, and its usability for training networks for navigation-related tasks is demonstrated.

Cardiac-gated spectroscopic photoacoustic imaging for ablation-induced necrotic lesion visualization.

Radiofrequency (RF) ablation is a minimally invasive therapy for atrial fibrillation. Conventional RF procedures lack intraoperative monitoring of ablation-induced necrosis, complicating assessment of completeness. While spectroscopic photoacoustic (sPA) imaging shows promise in distinguishing ablated tissue, multi-spectral imaging is challenging in vivo due to low imaging quality caused by motion. Here, we introduce a cardiac-gated sPA imaging (CG-sPA) framework to enhance image quality using a motion-gated averaging filter, relying on image similarity. Necrotic extent was calculated based on the ratio between spectral unmixed ablated tissue contrast and total tissue contrast, visualizing as a continuous color map to highlight necrotic area. The validation of the concept was conducted in both ex vivo and in vivo swine models. The ablation-induced necrotic lesion was successfully detected throughout the cardiac cycle through CG-sPA imaging. The results suggest the CG-sPA imaging framework has great potential to be incorporated into clinical workflow to guide ablation procedures intraoperatively.

Rebamipide Prevents the Hemoglobin Drop Related to Mucosal-Damaging Agents at a Level Comparable to Proton Pump Inhibitors.

Background/Aims: : The effect of proton pump inhibitors (PPIs) on the lower gastrointestinal (GI) tract is uncertain, with potential to worsen damage. This study aimed to find the best method for protecting the entire GI tract from mucosal damage. Methods: : A retrospective cohort study at Samsung Medical Center (2002-2019) included 195,817 patients prescribed GI mucosa-damaging agents. The primary goal was to assess the effectiveness of GI protective agents in preventing significant hemoglobin drops (>2 g/dL), indicating overall GI mucosal damage. Self-controlled case series and landmark analysis were used to address biases in real-world data. Results: : The incidence rate ratios for rebamipide, PPI, and histamine-2 receptor antagonist (H2RA) were 0.34, 0.33, and 0.52, respectively. Rebamipide showed a significantly lower incidence rate than H2RA and was comparable to PPIs. Landmark analysis revealed significant reductions in hemoglobin drop risk with rebamipide and H2RA, but not with PPI. Conclusions: : Rebamipide, like PPIs, was highly effective in preventing blood hemoglobin level decreases, as shown in real-world data. Rebamipide could be a comprehensive strategy for protecting the entire GI tract, especially when considering PPIs' potential side effects on the lower GI tract.

Clinicopathologic and Endosonographic Characteristics of Colon Subepithelial Tumors Discovered Incidentally.

BACKGROUND/AIMS: Colonoscopy is commonly used for colorectal cancer screening; therefore, the detection of colon subepithelial tumors (SETs) has also increased. Several research studies have been undertaken to diagnose and treat stomach and rectal SETs. The purpose of this study was to determine a diagnostic point for colon SETs by comparing histological findings with the endoscopic characteristics of colon SETs discovered by chance. METHODS: A total 194 patients underwent an endoscopic ultrasound (EUS) for suspicious colon SETs during a colonoscopy from May 2014 to December 2021. A total of 105 colon SETs, which were histologically diagnosed, were finally included. Fisher's exact test was used to determine the factors associated with malignant SETs. RESULTS: Colon SETs were predominantly present in the right colon (n = 73, 69.5%), particularly in the transverse colon (n = 32, 30.5%). The majority were smaller than 10 mm (n = 88, 83.8%), and they had hard consistencies (n = 84, 80%) and exhibited no surface changes (n = 96, 91.4%). Most of them were found in the submucosal layers (n = 54, 51.4%) and had a hypoechoic pattern (n = 56, 53.3%) in the EUS. Of the histologically confirmed cases, only three (3/105, 2.9%) were malignant. Most benign lesions were lipomas, suspected parasitic infections, or lesions caused by various inflammatory reactions, including fibrous/fibrocalcific lesions and necrotic nodules. All soft lesions were benign. Two of the three malignant lesions were adenocarcinomas, and the other was lymphoma. For the malignant SETs, there was a statistically significant alteration in the surface of the tumors (p < 0.001), and they were located where the muscularis mucosa layer was included (p = 0.008). The potential malignant SETs, granular cell tumors, and neuroendocrine tumors (NETs) had similar features, such as yellowish hypoechoic masses. Colon NETs were only found in the rectosigmoid junction. Parasitic infections and lesions, resulting in various inflammatory reactions, were observed as pale and hard SETs and mostly revealed as mixed echogenic masses located in the muscularis mucosa, submucosa, or multi-layers in the EUS. CONCLUSION: This study showed that small colon SETs were mostly benign lesions. Despite its rarity, pathological confirmation is crucial in cases where the SET has surface changes and has been located in a position where the muscularis mucosa layer was included on the EUS, due to the risk of malignancy.

Risk factors and management of iatrogenic colorectal perforation in diagnostic colonoscopy: a single-center cohort study.

BACKGROUND AND AIMS: Diagnostic colonoscopy plays a central role in colorectal cancer screening programs. We analyzed the risk factors for perforation during diagnostic colonoscopy and discussed the treatment outcomes. METHODS: We performed a retrospective analysis of risk factors and treatment outcomes of perforation during 74,426 diagnostic colonoscopies between 2013 and 2018 in a tertiary hospital. RESULTS: A total of 19 perforations were identified after 74,426 diagnostic colonoscopies or sigmoidoscopies, resulting in a standardized incidence rate of 0.025% or 2.5 per 10,000 colonoscopies. The majority (15 out of 19, 79%) were found at the sigmoid colon and recto-sigmoid junction. Perforation occurred mostly in less than 1000 cases of colonoscopy (16 out of 19, 84%). In particular, the incidence of perforation was higher in more than 200 cases undergoing slightly advanced colonoscopy rather than beginners who had just learned colonoscopy. Old age (≥ 70 years), inpatient setting, low body mass index (BMI), and sedation status were significantly associated with increased risk of perforation. Nine (47%) of the patients underwent operative treatment and ten (53%) were managed non-operatively. Patients who underwent surgery were often diagnosed with delayed or concomitant abdominal pain. Perforations of rectum tended to be successfully treated with endoscopic clipping. CONCLUSIONS: Additional precautions are required to prevent perforation in elderly patients, hospital settings, low BMI, sedated patients, or by a doctor with slight familiarity with endoscopies (but still insufficient experience). Endoscopic treatment should be actively considered if diagnosis is prompt, abdominal pain absent, and especially the rectal perforation is present.

Experience of primary intestinal lymphangiectasia in adults: Twelve case series from a tertiary referral hospital.

BACKGROUND: While primary intestinal lymphangiectasia (PIL) is considered a rare condition, there have been several reported cases in adults. Nevertheless, the absence of clear guidance from diagnosis to treatment and prognosis poses challenges for both physicians and patients. AIM: To enhance understanding by investigating clinical presentation, diagnosis, treatment, complications, and prognoses in adult PIL cases. METHODS: We enrolled adult patients diagnosed with PIL between March 2016 and September 2021. The primary outcome involved examining the diagnosis and treatment process of these patients. The secondary outcomes included identifying complications (infections, thromboembolism) and assessing prognoses (frequency of hospitalization and mortality) during the follow-up period. RESULTS: Among the 12 included patients, peripheral edema (100%) and diarrhea (75%) were the main presenting complaints. Laboratory tests showed that all the patients exhibited symptoms of hypoalbuminemia and hypogammaglobulinemia. Radiologically, the predominant findings were edema of the small intestine (67%) and ascites (58%). The typical endoscopic finding with a snowflake appearance was observed in 75% of patients. Among the 12 patients, two responded positively to octreotide and sirolimus, and eight who could undergo maintenance therapy discontinued subsequently. Complications due to PIL led to infection in half of the patients, thromboembolism in three patients, and one death. CONCLUSION: PIL can be diagnosed in adults across various age groups, with different severity and treatment responses among patients, leading to diverse complications and prognoses. Consequently, tailored treatments will be necessary. We anticipate that our findings will contribute to the management of PIL, an etiology of protein-losing enteropathy.

Tailoring Contacts for High-Performance 1D Ta2Pt3S8 Field-Effect Transistors.

Materials with van der Waals (vdW) unit structures rely on weak interunit vdW forces, facilitating physical separation and advancing nanomaterial research with remarkable electrical properties. Recently, there has been growing interest in one-dimensional (1D) vdW materials, celebrated for their advantageous properties, characterized by reduced dimensionality and the absence of dangling bonds. In this context, we synthesize Ta2Pt3S8, a 1D vdW material, and assess its suitability for field-effect transistor (FET) applications. Spectroscopic analysis and electrical characterization confirmed that the band gap and work function of Ta2Pt3S8 are 1.18 and 4.77 eV, respectively. Leveraging various electrode materials, we fabricated n-type FETs based on Ta2Pt3S8 and identified Cr as the optimal electrode, exhibiting a high mobility of 57 cm2 V-1 s-1. In addition, we analyzed the electron transport mechanism in n-type FETs by investigating Schottky barrier height, Schottky barrier tunneling width, and contact resistance. Furthermore, we successfully fabricated p-type operating Ta2Pt3S8 FETs using a molybdenum trioxide (MoO3) layer as a high work function contact electrode. Finally, we achieved Ta2Pt3S8 nanowire rectifying diodes by creating a p-n junction with asymmetric contact electrodes of Cr and MoO3, demonstrating an ideality factor of 1.06. These findings highlight the electronic properties of Ta2Pt3S8, positioning it as a promising 1D vdW material for future nanoelectronics and functional vdW-based device applications.

Measurements of Electrodermal Activity, Tissue Oxygen Saturation, and Visual Analog Scale for Different Cuff Pressures.

The quantification of comfort in binding parts, essential human-machine interfaces (HMI) for the functioning of rehabilitation robots, is necessary to reduce physical strain on the user despite great achievements in their structure and control. This study aims to investigate the physiological impacts of binding parts by measuring electrodermal activity (EDA) and tissue oxygen saturation (StO2). In Experiment 1, EDA was measured from 13 healthy subjects under three different pressure conditions (10, 20, and 30 kPa) for 1 min using a pneumatic cuff on the right thigh. In Experiment 2, EDA and StO2 were measured from 10 healthy subjects for 5 min. To analyze the correlation between EDA parameters and the decrease in StO2, a survey using the visual analog scale (VAS) was conducted to assess the level of discomfort at each pressure. The EDA signal was decomposed into phasic and tonic components, and the EDA parameters were extracted from these two components. RM ANOVA and a post hoc paired t-test were used to determine significant differences in parameters as the pressure increased. The results showed that EDA parameters and the decrease in StO2 significantly increased with the pressure increase. Among the extracted parameters, the decrease in StO2 and the mean SCL proved to be effective indicators. Such analysis outcomes would be highly beneficial for studies focusing on the comfort assessment of the binding parts of rehabilitation robots.

Determination of Gait Events and Temporal Gait Parameters for Persons with a Knee-Ankle-Foot Orthosis.

Gait event detection is essential for controlling an orthosis and assessing the patient's gait. In this study, patients wearing an electromechanical (EM) knee-ankle-foot orthosis (KAFO) with a single IMU embedded in the thigh were subjected to gait event detection. The algorithm detected four essential gait events (initial contact (IC), toe off (TO), opposite initial contact (OIC), and opposite toe off (OTO)) and determined important temporal gait parameters such as stance/swing time, symmetry, and single/double limb support. These gait events were evaluated through gait experiments using four force plates on healthy adults and a hemiplegic patient who wore a one-way clutch KAFO and a pneumatic cylinder KAFO. Results showed that the smallest error in gait event detection was found at IC, and the largest error rate was observed at opposite toe off (OTO) with an error rate of -2.8 ± 1.5% in the patient group. Errors in OTO detection resulted in the largest error in determining the single limb support of the patient with an error of 5.0 ± 1.5%. The present study would be beneficial for the real-time continuous monitoring of gait events and temporal gait parameters for persons with an EM KAFO.