Fine particulate matter (FPM) is a major component of air pollution and has emerged as a significant global health concern owing to its adverse health effects. Previous studies have investigated the correlation between bone health and FPM through cohort or review studies. However, the effects of FPM exposure on bone health are poorly understood. This study aimed to investigate the effects of FPM on bone health and elucidate these effects in vitro and in vivo using mice. Micro-CT analysis in vivo revealed FPM exposure decreased bone mineral density, trabecular bone volume/total volume ratio, and trabecular number in the femurs of mice, while increasing trabecular separation. Histological analysis showed that the FPM-treated group had a reduced trabecular area and an increased number of osteoclasts in the bone tissue. Moreover, in vitro studies revealed that low concentrations of FPM significantly enhanced osteoclast differentiation. These findings further support the notion that short-term FPM exposure negatively impacts bone health, providing a foundation for further research on this topic.

Atherosclerosis is a major contributor to cardiovascular disease, characterized by inflammation and lipid accumulation in arterial walls, leading to plaque formation. Elevated low-density lipoprotein cholesterol is a primary risk factor for atherosclerosis. All-trans retinoic acid (ATRA), a metabolite of vitamin A, has demonstrated anti-inflammatory effects and potential in regulating vascular injury. 9-cisretinoic acid (9cRA) is an active metabolite of vitamin A and activates the retinoid X receptor. This study investigates whether potassium retinoate (PA9RA), a synthetic combination of ATRA and 9cRA, offers superior efficacy in treating atherosclerosis compared to established treatments such as clopidogrel and atorvastatin. Male ApoE -/- mice were fed a Western-type diet and treated with PA9RA, clopidogrel, or atorvastatin for 10 weeks. The body weight, organ weight, serum biochemistry, and histopathology, including atherosclerotic lesion area and liver steatosis were assessed. PA9RA treatment led to a significant reduction in body weight and inguinal fat, with the 45 mg/kg/day dose showing marked efficacy in decreasing atherosclerotic lesion size and ameliorating liver steatosis. Histopathological evaluation revealed decreased foam cell formation and improved liver histology in PA9RA-treated groups compared to controls. Notable side effects included epidermal hyperplasia and gastric hyperplasia at high doses of PA9RA. PA9RA exhibits superior efficacy over clopidogrel and atorvastatin in ameliorating atherosclerosis and fatty liver in ApoE –/–mice. This study highlights PA9RA's potential as a promising therapeutic agent for atherosclerosis. Further research is needed to elucidate its mechanisms of action and assess long-term safety and efficacy.

Purpose: Persistent postoperative stiffness is a common complication after arthroscopic rotator cuff repair (ARCR).We hypothesized that a subacromial steroid injection (SAI) may improve the early outcomes in patients with persistent stiffness without increasing steroid-associated complications. Therefore, we evaluated the effectiveness and safety of SAI in patients with persistent stiffness 3 months after ARCR. Methods: We retrospectively analyzed 300 ARCR cases performed between January 2012 and May 2014, in which repair integrity was confirmed at postoperative 3 months. Patients were divided into SAI and control groups. The SAI group received a single SAI (triamcinolone 40 mg and ropivacaine 52.5 mg) to address postoperative stiffness, with no additional SAI thereafter. The control group did not receive any injections until the final follow-up. Functional and radiological outcomes were compared between the two groups. Results: The mean follow-up period was 18.1±4.7 months (range, 12.1–37.2 months), with no difference between groups (p=0.731). At the time of injection, the range of motion was significantly lower in the SAI (all p＜0.001). However, functional outcomes were comparable between the two groups at 3 months after injection and the final follow-up (all p＞ 0.05). The healing failure rate at the final follow-up also did not differ between the SAI and control groups (14.9% vs. 13.2%, p=0.671). Conclusion This short-term follow-up study suggests that the administration of a single SAI to treat persistent stiffness at 3 months after ARCR may improve functional recovery without increasing the risk of healing failure.

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: 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.

Purpose: Emphysematous pyelonephritis (EPN) is a life-threatening disease requiring immediate treatment. This multicenter retrospective cohort study aimed to analyze the mortality rate and risk factors associated with EPN. Materials and Methods: Between January 2011 and February 2021, 217 patients diagnosed with EPN via computed tomography who visited 14 teaching hospitals were retrospectively analyzed. Clinical data, including age, sex, comorbidities, Huang and Tseng classification, hydronephrosis, acute kidney injury, blood and urine tests, surgical interventions, percutaneous drainage, and conservative treatments, were compared between the survival and death groups. Risk factors for mortality due to EPN were analyzed using univariate and multivariate methods. Results: The mean age of survivors and deceased patients was 67.8 and 69.0 years, respectively (p=0.136). The sex distribution (male/female) was 48/146 and 8/15, respectively (p=0.298). Of the 217 patients, 23 died, resulting in a mortality rate of 10.6%. In univariate analysis, the Huang and Tseng classification (p=0.004), platelet count (p=0.005), and acute kidney injury (p=0.007) were significantly associated with mortality from EPN. In multivariate analysis, only the Huang and Tseng classification (p=0.029) was identified as a risk factor. Mortality rates according to the Huang and Tseng classification were as follows: class I (5.88%), class II (7.50%), class IIIa (14.28%), class IIIb (25.00%), and class IV (23.07%). Conclusions EPN is associated with a high mortality rate. Among various clinical factors, the Huang and Tseng classification was the most significant indicator for predicting mortality.

Purpose: Chronic obstructive pulmonary disease (COPD) is characterized by alveolar destruction and increased inflammation, leading to respiratory symptoms. This study aimed to identify the traits for COPD progression from mild to severe stages. Additionally, we explored the correlation between coronavirus disease-2019 (COVID-19) and COPD to uncover overlapping respiratory patterns. Materials and Methods: Bulk RNA sequencing was conducted on data from 43 healthy individuals and 39 COPD patients across one dataset (GSE239897) to distinguish COPD characteristics. Single-cell RNA analysis was then performed on samples from seven mild patients, seven moderate patients, and three severe patients from three datasets (GSE167295, GSE173896, and GSE227691) to analyze disease progression. Finally, single-nuclei RNA analysis was applied to data from seven healthy individuals and 20 COVID-19 patients from one dataset (GSE171524) to compare the two conditions. Results: Bulk RNA sequencing revealed enhanced inflammatory pathways in COPD patients, indicating increased inflammation.Single-cell RNA sequencing showed a stronger inflammatory response from mild to moderate COPD with a decrease from moderate to severe stages. COVID-19 displayed similar biological patterns to moderate COPD, suggesting that stage-specific COPD analysis could enhance COVID-19 management. Conclusion The analysis found that immune responses increased from mild to moderate stages but declined in severe cases, marked by reduced pulmonary T cell activation. The overlap between moderate COPD and COVID-19 suggests shared therapeutic strategies, warranting further investigation.