Background: Programmed death ligand 1 (PD-L1) expression cannot currently be predicted through radiological findings. This study aimed to develop a prediction model capable of differentiating between positive and negative PD-L1 expression through a radiomics-based investigation of computed tomography (CT) images in patients with urothelial carcinoma. Methods: Sixty-four patients with urothelial carcinoma who underwent immunohistochemical testing for PD-L1 were retrospectively reviewed. The number of patients in the positive and negative PD-L1 groups (PD-L1 expression >5%) was 14 and 50, respectively. CT images obtained 90 seconds after contrast medium administration were selected for radiomic extraction. For all tumors, 1,691 radiomic features were extracted from CT using a manually segmented three-dimensional volume of interest. Univariate and multivariate logistic regression analyses were performed to identify radiomic features that were significant predictors of PD-L1 expression. For the radiomics-based model, a receiver operating characteristic (ROC) analysis was performed. Results: Among 64 patients, 14 were included in the PD-L1 positive group. Logistic regression analysis found that the following radiomic features significantly predicted PD-L1 expression: wavelet-low-pass, low-pass, and high-pass filters (LLH)_gray-level size-zone matrix (GLSZM)_SmallAreaEmphasis, wavelet-LLH_firstorder_Energy, log-sigma-0-5-mm-3D_GLSZM_SmallAreaHighGrayLevelEmphasis, original_shape_Maximum2DDiameterColumn, wavelet-low-pass, low-pass, and low-pass filters (LLL)_gray-level run-length matrix (GLRLM)_ShortRunEmphasis, and exponential_firstorder_Kurtosis. The radiomics signature was –4.0934+21.6224 (wavelet-LLH_GLSZM_SmallAreaEmphasis)+0.0044 (wavelet-LLH_firstorder_Energy)–4.7389 (log-sigma-0-5-mm-3D_GLSZM_SmallAreaHighGrayLevelEmphasis)+0.0573 (original_shape_Maximum2DDiameterColumn)–29.5892 (wavelet-LLL_GLRLM_ShortRunEmphasis)–0.4324 (exponential_firstorder_Kurtosis). The area under the ROC curve model representing the radiomics signature for differentiating cases that were deemed PD-L1 positive based on immunohistochemistry was 0.96. Conclusions This preliminary radiomics model derived from contrast-enhanced CT predicted PD-L1 positivity in patients with urothelial cancer.

Objectives: The aim of this study was to determine the most effective treatment approach by comparing the impacts of various otolith reduction techniques in patients with apogeotropic lateral semicircular canal benign paroxysmal positional vertigo (LC-BPPV). Methods: We performed a multicenter randomized prospective study from January to December 2015, involving 72 consecutive patients with apogeotropic LC-BPPV. The patients were divided into three treatment groups: therapeutic head-shaking (group A), the Gufoni-Appiani maneuver (group B), and the cupulolith repositioning maneuver (CuRM; group C). Each group underwent evaluation and treatment up to the fourth week. Treatment success was defined as the disappearance of positional vertigo and nystagmus. Results: This study included 72 patients (49 male and 23 female), with a mean (±standard deviation) age of 55.4±13.5 years. The mean duration of vertigo experienced prior to treatment was 3.9±4.4 days. The mean latency and duration of nystagmus were 2.7±3.0 seconds and 47.9±15.8 seconds, respectively. The overall treatment frequency was 2.0±0.9. The number of treatments differed significantly among the three groups (P<0.05). After 4 weeks, the success rates for groups A, B, and C were 90.5%, 92.3%, and 100%, respectively. No significant difference was observed in the success rate across treatment methods and periods (P>0.05). However, CuRM was the only method with a 100% treatment success rate. Conclusion While no clear difference was observed among the three treatments for LC-BPPV, CuRM was found to be superior to the other approaches in the long term.

The monoamine hypothesis has significantly improved our understanding of mood disorders and their treatment by linking monoaminergic abnormalities to the pathophysiology of mood disorders. Even 50 years after the monoamine hypothesis was established, some patients do not respond to treatments for depression, including selective serotonin reuptake drugs. Accumulating evidence shows that patients with treatment-resistant depression (TRD) have severe abnormalities in the neuroplasticity and neurotrophic factor pathways, indicating that different treatment approaches may be necessary. Therefore, the glutamate hypothesis is gaining attention as a novel hypothesis that can overcome monoamine restrictions. Glutamate has been linked to structural and maladaptive morphological alterations in several brain areas associated with mood disorders. Recently, ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, has shown efficacy in TRD treatment and has received the U.S. Food and Drug Administration approval, revitalizing psychiatry research. However, the mechanism by which ketamine improves TRD remains unclear. In this review, we re-examined the glutamate hypothesis, bringing the glutamate system onboard to join the modulation of the monoamine systems, emphasizing the most prominent ketamine antidepressant mechanisms, such as NMDAR inhibition and NMDAR disinhibition in GABAergic interneurons. Furthermore, we discuss the animal models used in preclinical studies and the sex differences in the effects of ketamine.

Background/Aims: The prospective Crohn’s Disease Clinical Network and Cohort Study is a nationwide multicenter cohort study of patients with Crohn’s disease (CD) in Korea, aiming to prospectively investigate the clinical features and long-term prognosis associated with CD. Methods: Patients diagnosed with CD between January 2009 and September 2019 were prospectively enrolled. They were divided into two cohorts according to the year of diagnosis: cohort 1 (diagnosed between 2009 and 2011) versus cohort 2 (between 2012 and 2019). Results: A total of 1,175 patients were included, and the median follow-up duration was 68 months (interquartile range, 39.0 to 91.0 months). The treatment-free durations for thiopurines (p<0.001) and anti-tumor necrosis factor agents (p=0.018) of cohort 2 were shorter than those of cohort 1. Among 887 patients with B1 behavior at diagnosis, 149 patients (16.8%) progressed to either B2 or B3 behavior during follow-up. Early use of thiopurine was associated with a reduced risk of behavioral progression (adjusted hazard ratio [aHR], 0.69; 95% confidence interval [CI], 0.50 to 0.90), and family history of inflammatory bowel disease was associated with an increased risk of behavioral progression (aHR, 2.29; 95% CI, 1.16 to 4.50). One hundred forty-one patients (12.0%) underwent intestinal resection, and the intestinal resection-free survival time was significantly longer in cohort 2 than in cohort 1 (p=0.003). The early use of thiopurines (aHR, 0.35;95% CI, 0.23 to 0.51) was independently associated with a reduced risk of intestinal resection. Conclusions The prognosis of CD in Korea appears to have improved over time, as evidenced by the decreasing intestinal resection rate. Early use of thiopurines was associated with an improved prognosis represented by a reduced risk of intestinal resection.

A 60-year-old man diagnosed with unresectable hepatocellular carcinoma (HCC) presented to the hospital with pain in the perineal region. He had been taking lenvatinib every day for 2 months after he was diagnosed with HCC with metastases to the lymph node, small bowel mesentery, and retroperitoneal space. Enhanced abdominal computed tomography revealed mild elevation in intensity in the perineal subcutaneous tissue with subcutaneous emphysema. The patient was diagnosed with Common Terminology Criteria for Adverse Events grade 3, skin ulceration of stage IV with full-thickness skin loss and tissue necrosis in the muscular layer. The patient was taken off the medication with prescription of antibiotics, and after 3 weeks, the skin has fully recovered. This is the first report of an HCC patient who presented with a skin ulceration of stage IV after lenvatinib treatment. We recommend stopping the medication immediately and changing to alternative treatments with appropriate supportive care.

A 60-year-old man diagnosed with unresectable hepatocellular carcinoma (HCC) presented to the hospital with pain in the perineal region. He had been taking lenvatinib every day for 2 months after he was diagnosed with HCC with metastases to the lymph node, small bowel mesentery, and retroperitoneal space. Enhanced abdominal computed tomography revealed mild elevation in intensity in the perineal subcutaneous tissue with subcutaneous emphysema. The patient was diagnosed with Common Terminology Criteria for Adverse Events grade 3, skin ulceration of stage IV with full-thickness skin loss and tissue necrosis in the muscular layer. The patient was taken off the medication with prescription of antibiotics, and after 3 weeks, the skin has fully recovered. This is the first report of an HCC patient who presented with a skin ulceration of stage IV after lenvatinib treatment. We recommend stopping the medication immediately and changing to alternative treatments with appropriate supportive care.

Background/Aims: To improve the eradication rate of a first-line therapy for Helicobacter pylori infection, alternate regimens such as sequential, concomitant, and hybrid therapies have been tried. The aim of this study was to evaluate the eradication rate of the 10-day hybrid therapy as a first-line therapy. Materials and Methods: This retrospective study enrolled 124 patients from the Korea University Ansan Hospital between April 2016 and December 2019. The 10-day hybrid therapy comprised 5 days of dual therapy (proton pump inhibitor [PPI] standard dose and amoxicillin 1 g, twice daily) followed by 5 days of quadruple therapy (PPI, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg, twice daily). We compared the 10-day hybrid therapy with the 10-day concomitant therapy comprising PPI, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg, twice daily. Eradication was assessed by a 13C-urea breath test or gastroscopic biopsy at least 4 weeks after treatment completion. Results: The eradication rates of the 10-day hybrid and concomitant therapies were 74.2% (46/62) and 67.7% (42/62), respectively, in the intention-to-treat (ITT) analysis and 88.5% (46/52) and 82.4% (42/51), respectively, in the per-protocol (PP) analysis. There was no significant difference in the eradication rates between the two groups in the ITT (P=0.429) and PP analysis (P=0.380). Adverse events developed in 75.0% and 70.6% of patients in the hybrid and concomitant groups, respectively, but there was no significant difference (P=0.615). Conclusions The 10-day hybrid therapy can be an option for a first-line therapy of Helicobacter pylori infection.

Background/Aims: To improve the eradication rate of a first-line therapy for Helicobacter pylori infection, alternate regimens such as sequential, concomitant, and hybrid therapies have been tried. The aim of this study was to evaluate the eradication rate of the 10-day hybrid therapy as a first-line therapy. Materials and Methods: This retrospective study enrolled 124 patients from the Korea University Ansan Hospital between April 2016 and December 2019. The 10-day hybrid therapy comprised 5 days of dual therapy (proton pump inhibitor [PPI] standard dose and amoxicillin 1 g, twice daily) followed by 5 days of quadruple therapy (PPI, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg, twice daily). We compared the 10-day hybrid therapy with the 10-day concomitant therapy comprising PPI, amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg, twice daily. Eradication was assessed by a 13C-urea breath test or gastroscopic biopsy at least 4 weeks after treatment completion. Results: The eradication rates of the 10-day hybrid and concomitant therapies were 74.2% (46/62) and 67.7% (42/62), respectively, in the intention-to-treat (ITT) analysis and 88.5% (46/52) and 82.4% (42/51), respectively, in the per-protocol (PP) analysis. There was no significant difference in the eradication rates between the two groups in the ITT (P=0.429) and PP analysis (P=0.380). Adverse events developed in 75.0% and 70.6% of patients in the hybrid and concomitant groups, respectively, but there was no significant difference (P=0.615). Conclusions The 10-day hybrid therapy can be an option for a first-line therapy of Helicobacter pylori infection.