Objective: To systematically evaluate the long-term trajectory of pulmonary function test (PFT) and CT findings in COVID-19 survivors. Materials and Methods: A systematic literature search of PubMed and EMBASE was performed to identify studies published from January 2020 to June 2024 reporting PFT and/or chest CT outcomes at ≥6 months post-COVID-19, up to 36 months. The reference lists of relevant articles were also manually reviewed. Two investigators independently extracted study characteristics, patient demographics, and PFT and CT outcomes at prespecified follow-up intervals (6, 12, 24, and 36 months). Multivariate meta-analyses were conducted to evaluate temporal trends in lung function and radiological abnormalities. Sensitivity analyses, including stratification by disease severity and pooled analyses of studies with multiple follow-up time points, were performed to confirm the robustness of the findings. Results: In total, 152 studies (n = 25,766; mean age, 56.7 ± 13.2 years; 14,999 men) were included: 133 reporting PFT outcomes and 80 reporting CT findings. Diffusion capacity (DLCO) impairment was the most common abnormality, showing gradual improvement from 42% at 6 months to 35% at 36 months (P = 0.008) with a corresponding increase in the % predicted DLCO. Similarly, the prevalence of forced vital capacity (FVC) impairment decreased over time, accompanied by an increase in the % predicted FVC. On chest CT, the proportion of patients with no relevant findings remained stable at 30%–40% (P = 0.14).The prevalence of ground-glass opacities (GGO) decreased from 32% at 6 months to 20% at 36 months (P = 0.01), while that of fibrosis persisted at 27%–47% without a significant change (P = 0.28). Subgroup analysis based on disease severity revealed similar temporal trends in both low-severity and high-severity cohorts. Conclusion DLCO, FVC, and GGO findings improved gradually up to 36 months post-COVID-19; however, over one-third of the patients continued to exhibit reduced DLCO. Fibrosis persists with limited evidence of resolution over a 3-year period, suggesting a stable but nonprogressive pattern.

Objectives: Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey. Methods: From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status. Results: As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups. Conclusion This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.

Objectives: Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey. Methods: From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status. Results: As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups. Conclusion This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.

Objectives: Presenteeism is known to be a much more economically damaging social cost than disease rest while going to work despite physical pain. Since COVID-19, social discussions on the sickness benefit have been taking place as a countermeasure against presenteeism, and in particular, farmers and fishermen do not have an institutional mechanism for livelihood support when a disease other than work occurs. This study attempted to examine the relationship between agricultural, fishing, and forestry workers and presenteeism using the 6th Korean Work Conditions Survey. Methods: From October 2020 to January 2021, data from the 6th working conditions survey conducted on 17 cities and provinces in Korea were used, and a total of 34,981 people were studied. Control variables were gender, age, self-health assessment, education level, night work, shift work, monthly income, occupation, working hours per week, and employment status. Results: As a result of the analysis, farmers and fishermen showed the characteristics of the self-employed and the elderly, and as a result of the regression analysis, when farmers and fishermen analyzed the relationship with presenteeism tendency compared to other industry workers, farmers and fishermen increased by 23% compared to other industry groups. Conclusion This study is significant in that it has representation by utilizing the 6th working conditions survey and objectively suggests the need for a sickness benefit for farmers and fishermen who may be overlooked in the sickness benefit.

Background: Focal adhesions (FAs) is the most important process in the first step of osseointegration between preosteoblasts andtitanium (Ti). FAs improvement and pre-osteoblasts cell proliferation leads to successful Ti-based dental implants. This study aimed to confirm the applicability of rosmarinic acid (RA) as a functional substance for improving FAs and cell proliferation of MC3T3-E1 preosteoblasts on Ti surfaces during the first stage of osseointegration for successful Ti-based dental implants. Methods: We used MC3T3-E1 preosteoblasts on Ti discs incubated in a medium supplemented with or without 14 µg/ml to decipher the effects of RA on FAs and cell proliferation. FAs and proliferation of MC3T3-E1 cells on Ti discs were assessed via MTT assay.Actin-labeled cells and paxillin contacts were observed and imaged by fluorescent microscopy, and the associated signaling pathways were revealed through western blot analysis. Results: In RA-treated MC3T3-E1 cells on Ti discs, FAs between MC3T3-E1 preosteoblasts and Ti surfaces and the expression offocal adhesion kinase (FAK), phosphorylated FAK and paxillin proteins and filamentous-actin formation increased. RA increased the proliferation of MC3T3-E1 preosteoblasts on the Ti surface as well as the expression of Grab2, Ras, pERK1/2, and ERK1/2. In addition, the expression of secretory leukocyte protease inhibitor and thymosin b4, known as nanomolecules that enhance the interaction between implanted Ti materials and preosteoblasts in the RA-treated MC3T3-E1 preosteoblasts, increased. RA not only increased the FAs of MC3T3-E1 preosteoblasts on the Ti surface through the FAK/Paxillin signaling pathway, but also increased cell proliferation and mitosis through the FAK/Grab2/Ras/ERK1/2 signaling pathway. Conclusion RA can be applied as an effective functional substrate to improve the FAs and proliferation of MC3T3-E1 preosteoblatson Ti surfaces, which are essential in the first step of osseointegration between implanted Ti and bone tissue for the clinical success of Ti based dental implants.

Background: Hand hygiene is considered the simplest and most cost-effective method of infection prevention. Regular observation and feedback on hand hygiene compliance are key strategies for its enhancement. This study evaluated the effectiveness of hand hygiene surveillance, including direct observation and feedback, by comprehensively analyzing the reported hand hygiene compliance within the Korean National Healthcare-Associated Infections Surveillance System from 2019 to 2022. Methods: Participating medical institutions included general hospitals and hospitals with infection control departments that consented to participate. Hand hygiene surveillance was conducted using direct observation. Collected data, including healthcare workers, clinical areas, hand hygiene moments, and hand hygiene compliance, were recorded to calculate hand hygiene compliance rates. Additionally, the volume of alcohol-based hand sanitizers used per patient per day was investigated as an indirect indicator of hand hygiene compliance. The study was conducted from July 2019 to December 2022. Results: Hand hygiene compliance increased from 87.2% in Q3 2019 to 89.9% in 2022. Nurses and medical technologists showed the highest compliance rates, whereas doctors showed the lowest compliance rates. Intensive care units excelled in compliance, whereas emergency de partments lagged. Compliance was highest after patient contact and lowest when the patient’s surroundings were touched. Larger hospitals consumed more alcohol-based hand sanitizers than smaller hospitals did. Conclusion This study confirmed an improvement in hand hygiene compliance through sustained surveillance, indicating its contribution not only to preventing infection transfer within healthcare facilities but also to fostering a culture of hand hygiene in the country.

Background: Secretory leukocyte protease inhibitor (SLPI) protects tissues from proteases and promotes cell proliferation andhealing. SLPI also reduces periodontal inflammation and alveolar bone resorption by inhibiting proinflammatory cytokine expression in rat periodontal tissues and osteoblasts. However, little is known of the role of SLPI in the expression of osteoclast regulatory factors from osteoblasts, which are crucial for the interaction between osteoblasts and osteoclasts. Therefore, we aimed to determine the effects of SLPI on the regulation of osteoclasts and osteoblasts in LPS-treated alveolar bone and osteoblasts. Methods: Periodontitis was induced in rats using LPS. After each LPS injection, SLPI was injected into the same area. Immu-nohistochemical analysis was performed with antibodies against SLPI, RANKL, OPG, and Runx2 in the periodontal tissue. RT-PCR and western blotting were performed to determine the expression levels of SLPI, RANKL, OPG, and Runx2 in LPS- and SLPI/LPS-treated MC3T3-E1 cells. SLPI/LPS-treated MC3T3-E1 cells were also stained with Alizarin Red S. Results: Immunohistochemical analysis showed that the expression levels of SLPI, OPG, and Runx2 were higher while that of RANKLwas lower in the LPS/SLPI group relative to those in the LPS group. The mRNA and protein expression of SLPI, OPG, and Runx2 was higher in SLPI/LPS/MC3T3-E1 cells than in LPS/MC3T3-E1 cells, and RANKL expression was lower. During differentiation, OPG and Runx2 protein levels were higher whereas RANKL levels were lower in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 cells on days 0, 4, 7, and 10. In addition, mineralization and matrix deposition were higher in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 on days 7 and 10. SLPI decreased RANKL expression in LPS-treated alveolar bone and osteoblasts but increased the expression of OPG and Runx2. Conclusion SLPI can be considered as a regulatory molecule that indirectly regulates osteoclast activation via osteoblasts andpromotes osteoblast differentiation.

Background: Estrogen deficiency affects the structure and function of the salivary glands in women, leading to a decrease in salivary secretion and a change in the composition of saliva. Previous studies on changes in the salivary glands that cause estrogen deficiency have reported only partial results for the parotid and submandibular glands, and there are few comparative morphological studies of histological changes between the parotid and submandibular glands in ovariectomized rats (OVX) leading to estrogen deficiency. This study aimed to analyze the histopathological and histochemical changes in the parotid and submandibular salivary glands causing estrogen deficiency by using OVX, and to discuss the mechanism on these changes. Methods: The parotid and submandibular glands from sacrificed control and OVX groups were fixed with cold 4% paraformaldehyde in phosphate buffer (pH 7.2). The tissues were dehydrated using a series of graded ethyl alcohol and embedded in paraffin. For histopathological analysis, sections cut to a thickness of 6 to 7 μm were stained with hematoxylin and eosin (H&E). For histochemical analysis, Periodic acid-Schiff (PAS), Alcian blue (AB, pH 2.5), and PAS+AB (pH 2.5 and pH 1) staining was performed. Results: Histopathological analysis of OVX tissue showed that the parotid and submandibular salivary glands were broadly and clearly separated and divided into lobes. In OVX, acinar and ductal cells with condensed polymorphic or pyknotic nucleus, which are presumed to be characteristic of apoptotic cells, and degenerated cells with lipid deposition in cytoplasmic granules and ruptured membranes were increased. Histochemical analysis of OVX, confirmed an increase in the number and acidification of acinar secretory granules. Conclusion Histopathological and histochemical changes and the effects of estrogen deficiency are more evident in the submandibular salivary gland than in the parotid gland.

Background/aims: Circulating tumor cells (CTCs) with cancer stemness have been demonstrated to be a direct cause of tumor recurrence, and only few studies have reported the role of CTCs in liver transplantation (LT) for hepatocellular carcinoma (HCC). Methods: Epithelial cell adhesion molecule+ (EpCAM+), cluster of differentiation 90+ (CD90+) and EpCAM+/CD90+ CTCs were sorted via fluorescence-activated cell sorting, and transcripts level of EpCAM, K19 and CD90 in the peripheral blood were analyzed via real-time polymerase chain reaction preoperatively and on postoperative days 1 and 7 in 25 patients who underwent living donor liver transplantation (LDLT) for HCC. EpCAM protein was assessed in HCC tissue using immunohistochemical staining. The median follow-up duration was 40 months. Results: HCC after LDLT recurred in four out of 25 patients. Detection of EpCAM+ or CD90+ CTCs correlated well with their messenger RNA levels (p<0.05). EpCAM+ CTCs were readily detected in HCC tissue expressing EpCAM protein. The detection of EpCAM+ CTCs or EpCAM+/CD90+ CTCs before surgery and on postoperative day 1 was significantly associated with HCC recurrence after LT (all p<0.05). Pretransplant serum PIVKA-II >100 mAU/mL and postoperative day 1 EpCAM+/CD90+ CTCs were independent risk factors for HCC recurrence (hazard ratio, 14.64; 95% confidence interval, 1.08 to 198.20; p=0.043 and hazard ratio, 26.88; 95% confidence interval, 1.86 to 387.51; p=0.016, respectively). Conclusions EpCAM+/CD90+ CTCs can be used preoperatively and 1 day after LDLT as key biological markers in LT candidate selection and post-LDLT management.

Purpose: We investigate whether low-dose rapamycin is effective in preventing hepatocellular carcinoma (HCC) growth and treating HCC after tumor development in transgenic mice. Materials and Methods: We established transgenic mice with HCC induced by activated HrasG12V and p53 suppression. Transgenic mice were randomly assigned to five experimental groups: negative control, positive control, tacrolimus only, rapamycin only, and tacrolimus plus rapamycin. The mice were further divided into two groups according to time to commencement of immunosuppressant treatment: de novo treatment and post-tumor development. Results: In the de novo treatment group, marked suppression of tumor growth was observed in the rapamycin only group. In the post-tumor development group, the rapamycin only group displayed no significant suppression of tumor growth, compared to the positive control group. In T lymphocyte subset analysis, the numbers of CD4+ effector T cells and CD4+ regulatory T cells were significantly lower in the positive control, tacrolimus only, and tacrolimus plus rapamycin groups than the negative control group.Immunohistochemical analysis revealed significantly higher expression of phosphorylated-mTOR, 4E-BP1, and S6K1 in the positive control group than in the rapamycin only group. Conclusion Low-dose rapamycin might be effective to prevent HCC growth, but may be ineffective as a treatment option after HCC development.