Venous leg ulcers (VLUs) represent the most advanced manifestation of chronic venous disease and arise from sustained ambulatory venous hypertension due to superficial reflux, deep venous obstruction, or both. Accurate etiologic assessment is essential, with duplex ultrasound serving as the primary tool to identify axial reflux, perforator incompetence, and signs of proximal outflow obstruction in accordance with contemporary ESVS and SVS/AVF guidelines. Compression therapy remains the foundation of treatment, with inelastic or adjustable compression systems providing the most effective pressure reduction and edema control. Optimal wound care—including moisturebalancing dressings, debridement, and judicious use of antimicrobials—supports timely epithelialization. Adjunctive pharmacologic agents such as micronized purified flavonoid fraction, pentoxifylline, and sulodexide may further enhance healing. Early correction of superficial reflux accelerates healing and reduces recurrence, as demonstrated in the Early Venous Reflux Ablation trial. Iliac venous obstruction should be considered in nonhealing or recurrent ulcers, with IVUS-guided stenting appropriate when significant stenosis is confirmed. Integrating guideline-directed venous intervention, optimized compression, and structured wound care is central to improving long-term outcomes in VLU management.

Purpose: Incidental prostate cancer (IPCa) is frequently discovered during radical cystectomy (RC) for bladder cancer. While small-scale Korean studies have reported IPCa in 36%–50% of cases and clinically significant prostate cancer (sPCa) in up to 20%, large-scale data assessing its oncologic impact remain scarce. Materials and Methods: We retrospectively analyzed 1,358 male patients who underwent RC between June 1996 and January 2024. IPCa was histologically confirmed and classified per the International Society of Urological Pathology (ISUP) system. sPCa was defined as ISUP grade group (GG) ≥2. Kaplan-Meier analyses were conducted to evaluate survival outcomes. Results: IPCa was identified in 240 patients (17.7%), among whom 7.51% had sPCa. The distribution of ISUP GG was: GG1, 53.8%; GG2, 27.9%; GG3, 9.6%; GG4, 2.5%; and GG5, 1.7%. The proportion of sPCa remained stable across 3 time periods (p=0.281). Mean preoperative prostate-specific antigen (PSA) levels significantly differed among GG1, GG2, and GG3+ groups (2.14±2.37, 4.31±6.69, and 5.86±7.66 ng/mL, respectively; p<0.001). Mean patient age also varied significantly (67.99±8.39, 71.54±8.60, and 72.97±5.53 years; p<0.001). After a median follow-up of 44 months, deaths were unrelated to IPCa. Biochemical recurrence (BCR), defined as PSA ≥0.2 ng/mL, occurred in 11 patients (4.58%), with rates of 3.10%, 4.48%, and 12.12% in GG1, GG2, and GG3+ groups, respectively. Overall mortality rates across GG groups were similar (33.3%, 34.3%, and 33.3%; p=0.99). Compared to GG1, hazard ratios for overall survival were 1.03 (GG2, p=0.92), 0.87 (GG3, p=0.76), and 1.05 (GG4–5, p=0.89). Conclusion In this large Korean cohort, IPCa and sPCa were frequently detected at rates similar to global reports. Bladder cancer remained the primary determinant of survival. For older patients with elevated PSA, radical cystoprostatectomy may offer added benefit by treating undiagnosed high-risk IPCa.

Background: Escherichia coli (EC), Escherichia fergusonii (EF), and Citrobacter freundii (CF) are clinically significant Gram-negative bacteria that are difficult to differentiate because of their shared 16S rRNA gene sequences. Methods: This study presents a novel approach utilizing adenylate kinase (adk) gene polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis for the precise discrimination of EC, EF, and CF. Analysis of adk sequences revealed unique restriction sites for BtsIMutI, BtgI, and AgeI restriction enzymes at nucleotide positions 93 and 96. Results: Theoretical predictions translated into distinct banding patterns during agarose gel electrophoresis following PCR/restriction digestion. Experimental validation with reference strains and clinical isolates, including 84 EC and CF strains, demonstrated the efficacy of this method for differentiating these species. Assay specificity was confirmed by selective digestion of adk amplicons with BtsIMutI for EC and AgeI for CF. Conclusion This molecular technique provides a rapid and accurate method to discriminate between closely related bacterial species and is promising for clinical diagnostics and epidemiological studies. Thus, our adk PCR/restriction digestion assay is a valuable tool for the advancement of bacterial typing methods for EC, EF, and CF, and contributes to the ongoing exploration of microbial diversity and epidemiology.

Background: According to international pediatric urinary tract infection (UTI) guidelines, selecting ampicillin/ sulbactam or amoxicillin/clavulanate is recommended as the first-line treatment for pediatric UTI. In Korea, elevated resistance to ampicillin and ampicillin/sulbactam has resulted in the widespread use of third-generation cephalosporins for treating pediatric UTIs. This study aims to compare the efficacy of piperacillin-tazobactam (TZP) and cefotaxime (CTX) as first-line treatments in hospitalized children with UTIs. Materials and Methods: The study, conducted at Jeju National University Hospital, retrospectively analyzed medical records of children hospitalized for febrile UTIs between 2014 and 2017. UTI diagnosis included unexplained fever, abnormal urinalysis, and the presence of significant uropathogens. Treatment responses, recurrence, and antimicrobial susceptibility were assessed. Results: Out of 323 patients, 220 met the inclusion criteria. Demographics and clinical characteristics were similar between TZP and CTX groups. For children aged ≥3 months, no significant differences were found in treatment responses and recurrence. Extended-spectrum beta-lactamase (ESBL)-positive strains were associated with recurrence in those <3 months. Conclusion In Korea, escalating resistance to empirical antibiotics has led to the adoption of broad-spectrum empirical treatment. TZP emerged as a viable alternative to CTX for hospitalized children aged ≥3 months with UTIs.Consideration of ESBL-positive strains and individualized approaches for those <3 months are crucial.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, patients with myasthenia gravis (MG) were more susceptible to poor outcomes owing to respiratory muscle weakness and immunotherapy. Several studies conducted in the early stages of the COVID-19 pandemic reported higher mortality in patients with MG compared to the general population. This study aimed to investigate the clinical course and prognosis of COVID-19 in patients with MG and to compare these parameters between vaccinated and unvaccinated patients in South Korea. Methods: This multicenter, retrospective study, which was conducted at 14 tertiary hospitals in South Korea, reviewed the medical records and identified MG patients who contracted COVID-19 between February 2022 and April 2022. The demographic and clinical characteristics associated with MG and vaccination status were collected. The clinical outcomes of COVID-19 infection and MG were investigated and compared between the vaccinated and unvaccinated patients. Results: Ninety-two patients with MG contracted COVID-19 during the study. Nine (9.8%) patients required hospitalization, 4 (4.3%) of whom were admitted to the intensive care unit. Seventy-five of 92 patients were vaccinated before contracting COVID-19 infection, and 17 were not. During the COVID-19 infection, 6 of 17 (35.3%) unvaccinated patients were hospitalized, whereas 3 of 75 (4.0%) vaccinated patients were hospitalized (P < 0.001). The frequencies of ICU admission and mechanical ventilation were significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.019 and P = 0.032, respectively). The rate of MG deterioration was significantly lower in the vaccinated patients than in the unvaccinated patients (P = 0.041). Logistic regression after weighting revealed that the risk of hospitalization and MG deterioration after COVID-19 infection was significantly lower in the vaccinated patients than in the unvaccinated patients. Conclusion This study suggests that the clinical course and prognosis of patients with MG who contracted COVID-19 during the dominance of the omicron variant of COVID-19 may be milder than those at the early phase of the COVID-19 pandemic when vaccination was unavailable. Vaccination may reduce the morbidity of COVID-19 in patients with MG and effectively prevent MG deterioration induced by COVID-19 infection.

Background: Tuberculosis (TB) exposure in congregate settings related to neonates is a serious medical and social issue. TB exposure happens during the neonatal period, but contact investigations for exposed infants are usually conducted after the neonatal period.Generally, recommendations for screening and managing close contact are different for neonates and children. Thus, there are challenges in contact investigations. We aimed to report contact investigations with a single tuberculin skin test (TST) on infants exposed to infectious TB in a postpartum care center. Methods: The index case was a healthcare worker with active pulmonary TB: sputum acidfast bacilli smear negative, culture positive, and no cavitary lesion. All exposed infants underwent medical examinations and chest X-ray. After TB disease was ruled out, contacts received window period prophylaxis with isoniazid (INH) until three months after the last exposure. TST was performed only once after completing the prophylaxis. Results: A total of 288 infants were selected as high-priority contacts. At the initial contact investigation, the age of infants ranged from 8 to 114 days. None of these exposed infants had TB disease. The prevalence of latent TB infection (LTBI) was 25.3% (73/288; 95% confidence interval [CI], 20.7–30.7). There were no serious adverse events related to the window period prophylaxis or LTBI treatment with INH. During the 1-year follow-up period, no infants progressed to overt TB disease. The size of TST induration in infants vaccinated with percutaneous Bacillus Calmette-Guérin (BCG) vaccine was significantly larger than that of infants vaccinated with intradermal BCG vaccine (median, 8 mm vs. 5 mm; P = 0.002). In multiple logistic regression analysis, independent factors associated with TST positivity (≥ 10 mm induration) were male (adjusted odds ratio [aOR], 2.98; 95% CI, 1.6–5.64), percutaneous BCG vaccination (aOR, 3.30; 95% CI, 1.75–6.48), TST reading between 60 and 72 hours after injecting purified protein derivative (aOR, 2.87; 95% CI, 1.53–5.49), and INH prophylaxis more than four weeks (aOR, 0.49; 95% CI, 0.25–0.94). Conclusion A single TST at three months after the last TB exposure with INH prophylaxis could be used as a main protocol in contact investigations for infants exposed to infectious TB during the neonatal period in congregate settings in Korea.

The continuous emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants has provided insights for updating current coronavirus disease 2019 (COVID-19) vaccines. We examined the neutralizing activity of Abs induced by a BA.4/5-containing bivalent mRNA vaccine against Omicron subvariants BN.1 and XBB.1.5. We recruited 40 individuals who had received a monovalent COVID-19 booster dose after a primary series of COVID-19 vaccinations and will be vaccinated with a BA.4/5-containing bivalent vaccine. Sera were collected before vaccination, one month after, and three months after a bivalent booster.Neutralizing Ab (nAb) titers were measured against ancestral SARS-CoV-2 and Omicron subvariants BA.5, BN.1, and XBB.1.5. BA.4/5-containing bivalent vaccination significantly boosted nAb levels against both ancestral SARS-CoV-2 and Omicron subvariants. Participants with a history of SARS-CoV-2 infection had higher nAb titers against all examined strains than the infection-naïve group. NAb titers against BN.1 and XBB.1.5 were lower than those against the ancestral SARS-CoV-2 and BA.5 strains. These results suggest that COVID-19 vaccinations specifically targeting emerging Omicron subvariants, such as XBB.1.5, may be required to ensure better protection against SARS-CoV-2 infection, especially in high-risk groups.

Background: Percutaneous renal cyst sclerotherapy (PRCS) as a treatment for renal cysts is usually performed with a high concentration of ethanol (≥ 90%). This study reviewed cases in which a lower concentration of ethanol (83%) was used for the procedure in dogs. Methods: Records of cases of renal cysts treated by sclerotherapy using 83% ethanol in dogs were reviewed. Outcomes of the treatment were evaluated by comparing volumes of renal cysts before the procedure and the volumes after treatment, using ultrasound images with the volume reduction rates classified as follows: < 50% of initial volume (failed); ≥ 50% but < 80% of initial volume (partial success); ≥ 80% but < 95% of initial volume (great success); ≥ 95% of initial volume (complete success). Results: Out of nine dog kidneys, renal cysts sclerotherapy with 83% ethanol achieved partial success in one kidney, great success in four, and complete success in the other four. No side effect was observed. The mean of the volume-reduction rates was 90.00 ± 11.00 while the minimum and maximum reduction rates were 65% and 100%, respectively. Conclusions The lower ethanol concentration (83%) is good for disinfecting kidneys in PRCS.

Background/Aims: Patients with liver cirrhosis (LC) have low levels of branchedchain amino acids (BCAAs). There is accumulating evidence that BCAAs have anti- fibrotic effects in cirrhosis. This study is aimed to evaluate the effect of BCAAs on the function and phenotype of activated hepatic stellate cells (HSCs). Methods: LX-2, an immortalized human stellate cell line, was used in in vitro experiments. LX-2 cells were exposed to transforming growth factor β1 (TGF-β1) and BCAAs or to valine, leucine, and isoleucine, which are components of BCAAs. Activation of the TGF-β signaling pathway in LX-2 cells was observed using real- time quantitative polymerase chain reaction and Western blotting. Results: The increased expression of snail family transcriptional repressor 1 (SNAI1) was observed in LX-2 cells activated by TGF-β1. After BCAA treatment, its expression was significantly decreased at the mRNA level. The increased expression of Col1α1 and TIMP2 at the mRNA level and alpha smooth muscle actin at the protein level in activated LX-2 cells decreased after BCAA treatment. Among the BCAA components, leucine and valine significantly abrogated TGF-β-induced activation of LX-2 cells. BCAA treatment led to the decreased phosphorylation of Smad2 and p38 proteins, which are markers for Smad and Smad-independent p38 mitogen-activated protein kinase signaling pathways, respectively. Conclusions BCAA treatment can improve hepatic fibrosis by directly affecting the activated state of hepatic stellate cells through inhibition of the TGF-β signaling pathway. Among BCAA components, leucine and valine mainly abrogated TGF-β-induced activation of HSCs. Our results suggest that BCAA may be used to attenuate the progression of liver fibrosis.

Background: and Purpose Fingolimod (FTY) inhibits lymphocyte egress from lymphoid organs to cause lymphopenia, but the clinical implications of FTY-induced lymphopenia are not fully understood. We aimed to determine the frequency and severity of lymphopenia during FTY treatment among Korean patients with multiple sclerosis (MS), and its association with infections. Methods: We retrospectively reviewed the medical records of patients with MS treated using FTY from 12 referral centers in South Korea between March 2013 and June 2021. Patients were classified according to their nadir absolute lymphocyte count (ALC) during treatment:grade 1, 800–999/μL; grade 2, 500–799/μL; grade 3, 200–499/μL; and grade 4, <200/μL. Results: FTY treatment was administered to 69 patients with a median duration of 18 months (range=1–169 months), with 11 patients being treated for ≥7 years. During FTY treatment, mean ALCs were reduced after the first month (653.0±268.9/μL, mean±standard deviation) (p<0.0001) and remained low during treatment lasting up to 84 months. During follow-up, 41 (59.4%) and 7 (10.1%) patients developed grade-3 and grade-4 lymphopenia, respectively.No significant difference was found in age at FTY initiation, sex, baseline ALC, body mass index, or prior disease-modifying treatment between patients with and without grade-4 lymphopenia. Infections were observed in 11 (15.9%) patients, and the frequencies of patients with and without grade-4 lymphopenia were similar. Conclusions FTY treatment induced grade-4 lymphopenia in 10% of South Korean patients with MS, but did not appear to be associated with an increased infection risk.