Background/Aims: Proprotein-converting enzyme subtilisin-kexin type 9 (PCSK9) inhibitors act more promptly and efficiently than statins and reduce the risk of cardiovascular events in patients with acute coronary syndrome (ACS). This study aimed to assess the short-term effects of perioperative administration of a single-dose PCSK9 inhibitor in patients with ACS. Methods: This study included 789 consecutive patients undergoing percutaneous coronary intervention (PCI) for ACS. The primary clinical endpoint was the occurrence of major adverse cardiovascular events (MACEs) within one month, including cardiac death, non-fatal myocardial infarction, unanticipated revascularization, stroke, stent thrombosis, and rehospitalization for ischemic causes or heart failure. Results: PCSK9 inhibitors were administered to 201 of 789 patients. MACEs occurred in eight patients (4.0%) in the treated group and 60 patients (10.2%) in the non-treated group for one month (hazard ratio 0.38, 95% confidence interval 0.18 to 0.80, p = 0.010). The benefit of PCSK9 inhibitors in terms of MACEs was greater in the subgroup of patients treated more than 1 hour before PCI than in the subgroup treated less than 1 hour before PCI or treated after PCI and in the non-treated group. Conclusions In patients undergoing PCI for ACS, the risk of MACEs was lower in those treated with perioperative single-dose PCSK9 inhibitors than in those in the untreated group. This benefit was especially noticeable in the subgroups treated > 1 hour before PCI than in those treated less than 1 hour before PCI or after PCI, regardless of the clinical presentation of ACS.

Objective: This study aimed to investigate the prevalence and characteristics of impacted teeth (ITs) in orthodontic patients at university dental hospitals in Korea. Methods: This study included 14,774 patients who visited the Department of Orthodontics at 10 university dental hospitals in Korea between 2020 and 2022 and underwent orthodontic diagnosis. The prevalence and characteristics of ITs were investigated using orthodontic diagnostic records, radiographs, and diagnostic casts. Results: The prevalence of ITs, excluding third molar impaction, in Korean orthodontic patients was 13.6% (n = 2,014).The prevalence of ITs in pediatric orthodontic patients was 24.5% (n = 1,614).Of these patients, 68.2% had one IT, 27.5% had two ITs, 24.3% had bilateral IT, and 75.7% had unilateral IT. The most frequent IT was the maxillary canine (50.1%), followed by the mandibular second molar (11.7%), and maxillary second premolar (9.6%). An abnormal eruption path (46.5%) was the most frequent etiology. Orthodontic traction after surgical exposure (70.6%) was the most frequent treatment option. Among the patients with ITs, 29.8% had other dental anomalies, such as tooth agenesis (8.7%), microdontia (8.0%), and supernumerary teeth (5.1%). Furthermore, 50.8% had complications such as cystic lesions (18.3%), transposition (17.7%), and root resorption (14.8%).Among the patients with maxillary canine impaction, 62.2% had labial maxillary canine impaction and 21.1% had palatal maxillary canine impaction. Conclusions The prevalence of ITs in Korean orthodontic patients at university dental hospitals was high, particularly in pediatric orthodontic patients.

Objective: Temporary anchorage devices (TADs) have considerably reduced the need for anterior segmental osteotomy (ASO) in patients with Class I malocclusion. Most previous studies have been published before the widespread use of TADs, thus warranting new guidelines for determining the optimal approach for surgery and orthodontic treatment. This study aimed to establish guidelines on the choice between ASO and non-ASO (NASO) based on soft tissue considerations. Methods: Sixty-seven patients diagnosed with skeletal Class II malocclusion were divided into the ASO (n = 31) and NASO (n = 36) groups. Cephalometric analyses were used to compare the initial and final records to assess the effect of treatment on soft tissues. The interlabial gap, upper lip anterior to the E-line, lower lip anterior to the E-line, H-angle, upper lip to the nasion-perpendicular line, and nasolabial angle were evaluated. In particular, a proportional difference indicator between the upper and lower lips relative to the pogonion angle between the facial plane and CK line was presented, followed by statistics analyses. Statistical significance was set at P < 0.05. Results: Both groups demonstrated normal proportions of the upper and lower lips; however, significant differences favoring ASO over NASO in terms of soft tissue changes were observed for several variables. Conclusions ASO is advised if the required adjustment for the upper and lower lips is –4.0 mm and –5.0 mm, respectively. For modifications of –2.0 mm, NASO is preferred. This study provides clinical guidelines on the choice between ASO and NASO based on the required lip movement measurements.

Purpose: The aim of this study was to examine whether a combined exercise (EX), including aerobic, resistance, and inspiratory muscle training, reduces fatigue and dyspnea, improves physical fitness, and if increased physical fitness after exercise is associated with attenuating symptoms in young adults with mild long coronavirus disease (COVID) symptoms. Methods: Twenty-eight young adults (aged 23±4 years) with long COVID were randomly assigned to either the EX group (n=14), which underwent aerobic, resistance, and inspiratory muscle training three times per week for 8 weeks, or the control (CON) group (n=14). Symptoms of dyspnea and fatigue were assessed using self-report questionnaires.Cardiorespiratory fitness was directly measured during cardiopulmonary exercise testing, while muscle strength was measured by isokinetic muscle testing. These variables were measured before and after the exercise intervention. Results: Compared to the CON group, the EX group showed improvements in symptoms of fatigue and dyspnea, maximal oxygen consumption (VO2peak ), and peak torque, with significant interaction effects observed (p＜ 0.05). The EX group exhibited a mean difference of 2.9 mL/kg/min in VO2peak (95% confidence interval [CI], 1.8−4.0) and 13.0 Nm (95% CI, 6.1−19.8) in peak torque compared to the CON group (p＜0.05). Improvements in VO2peak were negatively associated with attenuations in both fatigue and dyspnea after the exercise intervention (p＜0.05). Conclusion These findings indicate that EX training can effectively alleviate symptoms and improve physical fitness in young adults with mild long COVID. Structured exercise training may serve as an effective intervention to improve the health of those with long COVID.

Purpose: Although lower body strength and size are often regarded as symbols of masculinity, their relationship to testosterone is unclear. This study aimed to determine the correlation between lower body strength, size, and testosterone levels. Materials and Methods: Serum testosterone levels, waist circumference, and body mass index (BMI) were measured in 69 men with erectile dysfunction (age >40 years). The circumferences of the thigh and calf were measured, and the muscle strength of the knee joints was evaluated using an isokinetic dynamometer. Patients were classified into three groups according to testosterone levels (group 1, <230 ng/dL; group 2, 230 to 350 ng/dL; group 3, >350 ng/dL). Differences in calf and thigh circumference, bilateral knee extension, and flexion strength between the three groups were investigated using a one-way analysis of variance. Pearson’s chi-square test was used to assess differences in lifestyle habits and underlying diseases. A partial correlation analysis was conducted to determine the association between testosterone levels and lower body size and strength. Results: There was no difference in BMI among the three groups, but waist circumference was significantly larger in group 1 than in groups 2 and 3. When comparing weight-adjusted values, bilateral thigh circumference showed a significant difference among the three groups. There was also a significant difference between the three groups in the weight-adjusted left calf circumference and in the weight-adjusted right knee extension strength. The partial correlation test showed a significant positive correlation between thigh and calf circumference values adjusted for weight and serum testosterone levels. Weight-adjusted knee extension strength demonstrated a significant positive correlation with serum testosterone levels. Conclusions Weight-adjusted thigh and calf circumferences, along with the thigh-to-waist ratio, showed a positive correlation with testosterone levels. Weight-adjusted knee extension strength was positively correlated with testosterone levels. Therefore, a robust thigh and strong lower body are related to testosterone.

Background: High-resolution chest computed tomography (CT) is a crucial assessment tool for diagnosing Birt-Hogg-Dubé (BHD) syndrome. This study aimed to analyze differences of lung cysts between BHD and other cystic lung diseases. Methods: From January 2020 to December 2022, patients with multiple lung cysts who underwent chest CT at Gangnam Severance Hospital were included. Results: Over a 3-year period (from January 2020 to December 2022), out of 52,823 patients who underwent a chest CT scan, 301 (0.6%) patients with multiple lung cysts were enrolled in this study. Of enrolled patients, 24 (8.0%) were diagnosed with BHD. In patients with BHD, 95.8% exhibited bilateral cysts, and 83.3% showed basal predominance. The cysts’ maximal diameter averaged 32.1 mm (interquartile range, 26.5 to 43.5). Additionally, 95.8% of patients with BHD had diverse cyst sizes and morphologies. Multivariate logistic regression analysis revealed that bilateral cysts (odds ratio [OR], 12.393; 95% confidence interval [CI], 1.613 to 274.682; p=0.038), basal predominance (OR, 8.511; 95% CI, 2.252 to 39.392; p=0.002), maximum diameter (OR, 1.053; 95% CI, 1.009 to 1.108; p=0.032), and diversity of morphology (OR, 19.513; 95% CI, 2.833 to 398.119; p=0.010) were significant factors associated with BHD diagnosis. A multivariate prediction model for BHD diagnosis demonstrated a sensitivity of 95.83%, a specificity of 81.22%, and an area under the receiver operating characteristic curve of 0.951 (95% CI, 0.914 to 0.987). Conclusion Distinguishing features of lung cysts from other cystic lung diseases include bilateral cysts, basal dominance, large size, and irregular shape.

A significant portion of newly diagnosed lung cancer cases occurs in populations exposed to air pollution. The World Health Organization has identified air pollution as a human carcinogen, prompting many countries to implement monitoring systems for ambient particulate matter (PM). PM is composed of a complex mixture of organic and inorganic particles, both solid and liquid, that are found in the air. Given the carcinogenic properties of PM and the high prevalence of lung cancer among exposed populations, exploring their connection and clinical implications is critical for effectively preventing lung cancer in this group. This review explores the relationship between ambient PM and lung cancer. Epidemiological studies have demonstrated a dose-response relationship between PM exposure and lung cancer risk. PM exposure induces oxidative stress, disrupts the body’s redox balance, and causes DNA damage, which is a crucial factor in cancer development. Recent findings on the strong correlation between ambient PM and adenocarcinoma highlight the importance of understanding the specific molecular and pathological mechanisms underlying pollution-related lung cancer. In addition to efforts to control emission sources at the international level, a more individualized approach is essential for preventing PM-related lung cancer.

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are correlated with high morbidity and mortality rates. Guidelines that consider local epidemiologic data are fundamental for identifying optimal treatment strategies. However, Korea has no HAP/VAP guidelines. This study was conducted by a committee of nine experts from the Korean Academy of Tuberculosis and Respiratory Diseases Respiratory Infection Study Group using the results of Korean HAP/VAP epidemiologic studies. Eleven key questions for HAP/VAP diagnosis and treatment were addressed. The Convergence of Opinion on Suggestions and Evidence (CORE) process was used to derive suggestions, and evidence levels and recommendation grades were in accordance with the Grading of Recommendations Assessment Development and Evaluation (GRADE) methodology. Suggestions were made for the 11 key questions pertinent to diagnosis, biomarkers, antibiotics, and treatment strategies for adult patients with HAP/VAP. Using the CORE process and GRADE methodology, the committee generated a series of recommendations for HAP/VAP diagnosis and treatment in the Korean context.

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive lung disease that culminates in respiratory failure and death due to irreversible scarring of the distal lung. While initially considered a chronic inflammatory disorder, the aberrant function of the alveolar epithelium is now acknowledged as playing a central role in the pathophysiology of IPF. This study aimed to investigate the regenerative capacity of alveolar type 2 (AT2) cells using IPF-derived alveolar organoids and to examine the effects of disease progression on this capacity. Methods: Lung tissues from three pneumothorax patients and six IPF patients (early and advanced stages) were obtained through video-assisted thoracoscopic surgery and lung transplantation. HTII-280+ cells were isolated from CD31-CD45-epithelial cell adhesion molecule (EpCAM)+ cells in the distal lungs of IPF and pneumothorax patients using fluorescence-activated cell sorting (FACS) and resuspended in 48-well plates to establish IPF-derived alveolar organoids. Immunostaining was used to verify the presence of AT2 cells. Results: FACS sorting yielded approximately 1% of AT2 cells in early IPF tissue, and the number decreased as the disease progressed, in contrast to 2.7% in pneumothorax. Additionally, the cultured organoids in the IPF groups were smaller and less numerous compared to those from pneumothorax patients. The colony forming efficiency decreased as the disease advanced. Immunostaining results showed that the IPF organoids expressed less surfactant protein C (SFTPC) compared to the pneumothorax group and contained keratin 5+ (KRT5+) cells. Conclusion This study confirmed that the regenerative capacity of AT2 cells in IPF decreases as the disease progresses, with IPF-derived AT2 cells inherently exhibiting functional abnormalities and altered differentiation plasticity.

Purpose: The study investigated whether incorporating magnetic resonance imaging (MRI) alongside ultrasonography (US) in the preoperative evaluation is associated with differing survival outcomes between male and female breast cancer patients in a matched analysis. Additionally, clinicopathological prognostic factors were analyzed. Methods: Between January 2005 and December 2020, 93 male and 28,191 female patients who underwent breast surgery were screened. Exact matching analysis was conducted for age, pathologic T and N stages, and molecular subtypes. The clinicopathological characteristics and preoperative imaging methods of the matched cohorts were reviewed. Disease-free survival (DFS) and overall survival (OS) were assessed using Kaplan-Meier analysis, and Cox proportional hazards regression analysis was used to identify prognostic factors. Results: A total of 328 breast cancer patients (61 men and 267 women) were included in the matched analysis. Male patients had worse DFS (10-year DFS, 70.6% vs. 89.2%; P=0.001) and OS (10-year OS, 64.4% vs. 96.3%; P<0.001) than female patients. The pathologic index cancer size (hazard ratio [HR], 2.013; 95% confidence interval [CI], 1.063 to 3.810; P=0.032) was associated with worse DFS, whereas there were no significant factors associated with OS. Adding MRI to US for preoperative evaluation was not associated with DFS (HR, 1.117; 95% CI, 0.223 to 5.583; P=0.893) or OS (HR, 1.529; 95% CI, 0.300 to 7.781; P=0.609) in male patients. Conclusion Adding breast MRI to US in the preoperative evaluation was not associated with survival outcomes in male breast cancer patients, and the pathologic index cancer size was associated with worse DFS.