Background: Histone deacetylase 6 (HDAC6), belonging to class IIb of histone deacetylases, regulates theacetylation of the cytoplasmic protein α-tubulin. The overexpression of HDAC6 is linked to the development oftumors, and inhibiting HDAC6 is known to trigger apoptosis in multiple myeloma cells. In addition to its application in cancer treatment, bortezomib, a proteasome inhibitor, is widely used in managing multiple myeloma and has shown effectiveness in patients with both newly diagnosed and relapsed disease. However, the treatment regimen may be delayed or discontinued due to the risk of peripheral neuropathy, a significant non-hematologic side effect. Methods: Animal models of peripheral neuropathy induced by various anti-cancer drugs were established, confirming the potential of HDAC6 inhibitors as a treatment for this condition. Six- to eight-week-old male Sprague Dawley rats were utilized to create these models. Mechanical allodynia and electron microscopy served as indicators of peripheral neuropathy. The HDAC6 inhibitor CKD-011 was administered at doses of 5, 10, 20, and 40 mg/kg. Results: In an animal model of bortezomib-induced peripheral neuropathy, CKD-011, an HDAC6 inhibitor, effectively ameliorated peripheral neuropathy. Similarly, CKD-011 administration demonstrated recovery from peripheral neuropathy in models induced with oxaliplatin, paclitaxel, and cisplatin. Conclusions These findings suggest that HDAC6 inhibitors have the potential to mitigate peripheral neuropathy induced by chemotherapeutic agents.

Purpose: Identifying and managing risk factors for lower urinary tract symptoms (LUTS) is crucial because it impacts the quality of life of elderly individuals. Lifestyle factors, including physical activity (PA), and their relationship with LUTS have not been well studied. This objective of this study was to investigate the association between PA and LUTS. Materials and Methods: A total of 7,296 men were included in this cross-sectional study. PA was quantified in metabolic equivalent (MET)-hours per week, and LUTS severity was assessed using the international prostate symptom score. Logistic regression was used to analyze the association between PA and LUTS, including voiding and storage symptoms. Results: The average age of the participants was 57.8 years, and the prevalence of LUTS was 41.3%. After adjusting for potential confounders, PA was inversely associated with the prevalence and severity of moderate-to-severe LUTS, showing a dose-response pattern (all p for trend <0.01). Compared to the minimal activity group, which engaged in <5 MET-hours per week of PA, the odds ratios for moderate to severe LUTS were 0.83 (95% confidence interval [CI]: 0.72–0.97) for men engaging in 15–30 MET-hours per week, 0.82 (95% CI: 0.71–0.95) for 30–60 MET-hours per week, and 0.72 (95% CI: 0.62–0.84) for ≥60 MET-hours per week. The possible protective effect of PA was still observed in the additional analysis for voiding and storage symptoms showing the same dose-response pattern (all p for trend <0.01). Conclusions A higher PA level was associated with a lower prevalence and severity of total, voiding, and storage LUTS in a dose-dependent manner in Korean men.

High-flow nasal cannula (HFNC) is a noninvasive respiratory support system that delivers air that is heated at 31°C−38°C, humidified 100%, and oxygen-enriched at a constant high flow rate of 15−60 L/min. Because of its numerous physiological benefits, convenience, and minimal side effects, HFNC has been increasingly used over the past decade in patients with acute hypoxemic respiratory failure, yet the clinical benefits of long-term HFNC remain uncertain. Several studies have suggested its potential use as an alternative home oxygen therapy for patients with chronic stable lung diseases, such as chronic obstructive pulmonary disease (COPD), interstitial lung disease, and bronchiectasis. The use of long-term home HFNC in patients with chronic respiratory failure is an emerging area with promising potential. Despite limited clinical research, this review aims to describe the physiology of HFNC use and summarize the current evidence on its long-term application, to provide healthcare providers with insights and perspectives on the potential role of long-term home HFNC.

Background: Respiratory infections play a major role in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study assessed the prevalence of bacterial and viral pathogens and their clinical impact on patients with AECOPD. Methods: This retrospective study included 1,186 patients diagnosed with AECOPD at 28 hospitals in South Korea between 2015 and 2018. We evaluated the identification rates of pathogens, basic patient characteristics, clinical features, and the factors associated with infections by potentially drug-resistant (PDR) pathogens using various microbiological tests. Results: Bacteria, viruses, and both were detected in 262 (22.1%), 265 (22.5%), and 129 (10.9%) of patients, respectively. The most common pathogens included Pseudomonas aeruginosa (17.8%), Mycoplasma pneumoniae (11.2%), Streptococcus pneumoniae (9.0%), influenza A virus (19.0%), rhinovirus (15.8%), and respiratory syncytial virus (6.4%). Notably, a history of pulmonary tuberculosis (odds ratio [OR], 1.66; p=0.046), bronchiectasis (OR, 1.99; p=0.032), and the use of a triple inhaler regimen within the past 6 months (OR, 2.04; p=0.005) were identified as significant factors associated with infection by PDR pathogens. Moreover, patients infected with PDR pathogens exhibited extended hospital stays (15.9 days vs. 12.4 days, p=0.018) and higher intensive care unit admission rates (15.9% vs. 9.5%, p=0.030). Conclusion This study demonstrates that a variety of pathogens are involved in episodes of AECOPD. Nevertheless, additional research is required to confirm their role in the onset and progression of AECOPD.

Background: Malnutrition exacerbates the prognosis of numerous diseases; however, its specific impact on severe coronavirus disease 2019 (COVID-19) outcomes remains insufficiently explored. Methods: This multicenter study in Korea evaluated the nutritional status of 1,088 adults with severe COVID-19 using the Geriatric Nutritional Risk Index (GNRI) based on serum albumin levels and body weight. The patients were categorized into two groups: GNRI >98 (no-risk) and GNRI ≤98 (risk). Propensity score matching, adjusted for demographic and clinical variables, was conducted. Results: Of the 1,088 patients, 642 (59%) were classified as at risk of malnutrition. Propensity score matching revealed significant disparities in hospital (34.3% vs. 19.4%, p<0.001) and intensive care unit (ICU) mortality (31.5% vs. 18.9%, p<0.001) between the groups. The risk group was associated with a higher hospital mortality rate in the multivariate Cox regression analyses following propensity score adjustment (hazard ratio [HR], 1.64; p=0.001). Among the 670 elderly patients, 450 were at risk of malnutrition. Furthermore, the risk group demonstrated significantly higher hospital (52.1% vs. 29.5%, p<0.001) and ICU mortality rates (47.2% vs. 29.1%, p<0.001). The risk group was significantly associated with increased hospital mortality rates in the multivariate analyses following propensity score adjustment (HR, 1.66; p=0.001). Conclusion Malnutrition, as indicated by a low GNRI, was associated with increased mortality in patients with severe COVID-19. This effect was also observed in the elderly population. These findings underscore the critical importance of nutritional assessment and effective interventions for patients with severe COVID-19.

Background: The development of frailty at hospital discharge affects the clinical outcomes in severe coronavirus disease 2019 (COVID-19) survivors who had no frailty before hospitalization. We aimed to describe the prevalence of new frailty using the clinical frailty scale (CFS) and evaluate its associated factors in patients with severe COVID-19 without pre-existing frailty before hospitalization. Methods: We performed a secondary analysis of clinical data from a nationwide retrospective cohort collected from 22 hospitals between January 1, 2020 and August 31, 2021. The patients were at least 19 years old and survived until discharge after admission to the intensive care unit (ICU) because of severe COVID-19. Development of new frailty was defined as a CFS score ≥5 at hospital discharge. Results: Among 669 severe COVID-19 survivors without pre-existing frailty admitted to the ICU, the mean age was 65.2±12.8 years, 62.5% were male, and 50.2% received mechanical ventilation (MV). The mean CFS score at admission was 2.4±0.9, and new frailty developed in 27.8% (186/483). In multivariate analysis, older age, cardiovascular disease, CFS score of 3–4 before hospitalization, increased C-reactive protein level, longer duration of corticosteroid treatment, and use of MV and extracorporeal membrane oxygenation were identified as factors associated with new-onset frailty. Conclusion Our study suggests that new frailty is not uncommon and is associated with diverse factors in survivors of severe COVID-19 without pre-existing frailty.

Ultrasonography (US) is a sensitive and radiation-free technique for diagnosing deep vein thrombosis (DVT). Therefore, when DVT is clinically suspected but not detected on US, radiologists should consider a range of alternative differential diagnoses. This review article presents the imaging findings of clinical conditions that mimic DVT, which can be distinguished using a multimodal radiologic approach. Additionally, DVT mimics can be categorized into two groups based on whether a flat or normal waveform is observed on Doppler US. This article details the imaging findings and clinical presentations of DVT mimics, organized by these classifications. This information may help radiologists make more accurate diagnoses, enabling patients to receive appropriate treatment in a timely manner.

Purpose: The immunological response and adverse effects of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) in patients receiving coronavirus disease-2019 (COVID-19) vaccines remain unclear. We aimed to evaluate the effects of these vaccines on AAV disease activity. Materials and Methods: We reviewed the medical records of 52 patients with AAV who had received at least second doses of the COVID-19 vaccine and evaluated their immunogenicity by measuring the anti-spike (S) antibody (Ab) titer levels using the Roche Elecsys® immunoassay. Responses to the Birmingham Vasculitis Activity Score (BVAS) tool and 36-Item Short Form Survey before and after vaccination were obtained to assess AAV disease activity. Vaccine reactivity was measured using a standardized questionnaire. Results: We enrolled 52 patients with AAV. No differences were found between those who received second and third doses of vaccination in terms of AAV type, disease activity, vaccine type, or the use of immunosuppressive agents, including steroids. The median anti-S Ab titer was 3967.0 after third doses compared to 419.0 after second doses (p=0.001). Except for mycophenolate mofetil (MMF), when immunosuppressants were administered in conjunction with steroids, the Ab titer was higher after the third vaccination than that after the second dose. The BVAS remained unchanged before and after second and third doses. No life-threatening adverse events were reported. Conclusion Although COVID-19 vaccine may not produce sufficient antibodies in patients taking MMF, the vaccine did not exacerbate disease activity or cause severe side effects. Therefore, COVID-19 vaccines should be considered in patients with AAV.

Purpose: Tracheal resection with end-to-end anastomosis (TREE) has many advantages over conservative treatment in terms of long-term results; however, this method requires improved safety and accessibility. We aimed to combine expanded venovenous extracorporeal membrane oxygenation (ECMO) during TREE surgery. Materials and Methods: Between May 2006 and December 2022, 41 patients diagnosed with tracheal stenosis or tracheal tumors underwent TREE. The non-ECMO and ECMO groups were classified based on the presence or absence of intraoperative ECMO support. Results: Reconstruction length was slightly longer in the ECMO group than in the non-ECMO group, but there was no statistical significance (p=0.082). There was no significant difference between the two groups in terms of operative time (p=0.698), estimated blood loss (p=0.210), and duration of mechanical ventilation (p=0.713). There was a significant difference in intensive care unit stay between the two groups (p=0.013) due to the postoperative maintenance of ECMO. There were no cases of early mortality in either group during hospitalization (p>0.999). Conclusion ECMO support could assist in more challenging cases as it makes surgery easier in difficult patient scenarios.

Background: s/Aims: Radiofrequency ablation (RFA) is widely employed for managing recurrent hepatocellular carcinoma (HCC) following transarterial chemoembolization (TACE). However, local tumor progression (LTP) after treatment remains a significant challenge. This study evaluates the efficacy of saline-perfused bipolar RFA using twin internally cooled-perfusion (TICP) electrodes in managing recurrent HCC post-TACE. Methods: Between September 2017 and January 2019, 100 patients with 105 nodules (mean diameter, 1.6±0.5 cm) were prospectively enrolled. Bipolar RFA with TICP electrodes was performed under ultrasound-computed tomography/magnetic resonance fusion guidance. The primary outcome was the 2-year cumulative incidence of LTP. Results: The technical success and technique efficacy rates were 100% and 97%, respectively. During a median follow-up period of 34.0 months (range, 3-41), the estimated LTP rates were 13.3% at 1 year and 17.7% at 2 years. Progression-free survival rates were 37.8% and 27.7% at 1 year and 2 years, respectively. Conclusions Saline-perfused bipolar RFA using TICP electrodes demonstrates promising results for recurrent HCC after TACE, achieving high technical success and effective local tumor control rates.