Purpose: Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection. Materials and Methods: Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee. Results: A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors. Conclusion Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.

Purpose: Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection. Materials and Methods: Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee. Results: A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors. Conclusion Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.

Purpose: Developmentally regulated GTP-binding protein 2 (DRG2) regulates microtubule dynamics and G2/M arrest during docetaxel treatment. Poly ADP-ribose polymerase (PARP) acts as an important repair system for DNA damage caused by docetaxel treatment. This study investigated whether DRG2 expression affects response to PARP inhibitors (olaparib) using prostate cancer cell lines PC3, DU145, LNCaP-FGC, and LNCaP-LN3. Materials and Methods: The cell viability and DRG2 expression levels were assessed using colorimetric-based cell viability assay and western blot. Cells were transfected with DRG2 siRNA, and pcDNA6/V5-DRG2 was used to overexpress DRG2. Flow cytometry was applied for cell cycle assay and apoptosis analysis using the Annexing V cell death assay. Results: The expression of DRG2 was highest in LNCaP-LN3 and lowest in DU145 cells. Expressions of p53 in PC3, DU145, and the two LNCaP cell lines were null-type, high-expression, and medium-expression, respectively. In PC3 (DRG2 high, p53 null) cells, docetaxel increased G2/M arrest without apoptosis; however, subsequent treatment with olaparib promoted apoptosis. In DU145 and LNCaP-FGC (DRG2 low), docetaxel increased sub-G1 but not G2/M arrest and induced apoptosis, whereas olaparib had no additional effect. In LNCaP-LN3 (DRG2 high, p53 wild-type), docetaxel increased sub-G1 and G2/M arrest, furthermore olaparib enhanced cell death. Docetaxel and olaparib combination treatment had a slight effect on DRG2 knockdown PC3, but increased apoptosis in DRG2-overexpressed DU145 cells. Conclusions DRG2 and p53 expressions play an important role in prostate cancer cell lines treated with docetaxel, and DRG2 levels can predict the response to PARP inhibitors.

Purpose: Recent development in perioperative treatment of resectable non–small cell lung cancer (NSCLC) have changed the landscape of early lung cancer management. The ADAURA trial has demonstrated the efficacy of adjuvant osimertinib treatment in resectable NSCLC patients; however, studies are required to show which subgroup of patients are at a high risk of relapse and require adjuvant epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor treatment. This study evaluated risk factors for postoperative relapse among patients who underwent complete resection. Materials and Methods: Data were obtained from the Korean Association for Lung Cancer Registry (KALC-R), a database created using a retrospective sampling survey by the Korean Central Cancer Registry (KCCR) and the Lung Cancer Registration Committee. Results: A total of 3,176 patients who underwent curative resection was evaluated. The mean observation time was approximately 35.4 months. Among stage I to IIIA NSCLC patients, the EGFR-mutant subgroup included 867 patients, and 75.2%, 11.2%, and 11.8% were classified as stage I, stage II, and stage III, respectively. Within the EGFR-mutant subgroup, 44 (5.1%) and 121 (14.0%) patients showed early and late recurrence, respectively. Multivariate analysis on association with postoperative relapse among the EGFR-mutant subgroup showed that age, pathologic N and TNM stages, pleural invasion status, and surgery type were independent significant factors. Conclusion Among the population that underwent complete resection for early NSCLC with EGFR mutation, patients with advanced stage, pleural invasion, or limited resection are more likely to show postoperative relapse.

Background: Humans are exposed to mercury primarily in its highly toxic form, methyl mercury, which is known to have adverse effects on various organs and systems. The negative impact of mercury exposure on the growth, development, and mental health of children, from infancy to adolescence, is well-documented. However, there are no internationally standardized safe limits for mercury exposure. This study investigated the impact of dietary habits and higher body mass index (BMI) on blood mercury levels in adolescents. Methods: This study analyzed the data from the 4th Korean National Environmental Health Survey (KoNEHS) 2018–2020. The focus was on 825 middle and high school students aged 13–18 years, whose blood mercury levels were measured. A survey on dietary and lifestyle habits was also conducted. Blood mercury levels were categorized by geometric median values, and associations with overweight status and seafood consumption were examined using a generalized linear model. Results: The geometric mean blood mercury level for the entire sample was 1.37 μg/L, with levels of 1.31 μg/L in normal-weight individuals and 1.43 μg/L in overweight individuals, showing a statistically significant difference between the two groups. After adjusting for other variables, blood mercury levels were significantly associated with overweight status (estimate: 0.084; p = 0.018; 95% confidence interval [CI]: 0.015–0.153), consumption of large fish and tuna more than once a week (estimate: 0.18; p = 0.001; 95% CI: 0.077–0.284), and consumption of fish once a week or more (estimate: 0.147; p = 0.004; 95% CI: 0.043–0.250). Conclusions In adolescents, a higher BMI and an increased consumption of large fish, tuna, and fish were associated with higher blood mercury levels. Notably, a stronger association was found between large fish consumption and blood mercury levels in the overweight group. These findings suggest the need to moderate seafood consumption and establish more proactive mercury exposure standards for adolescents.

Background: This study aimed to investigate the analgesic and preventive effect of low-level laser therapy (LLLT) on the incisional pain model and spinal nerve ligation (SNL) model in rats and identify the possible mechanisms of action. Methods: Male Sprague-Dawley rats were used, divided into different treatment groups. The single application group received LLLT before or after skin incision or SNL. The consecutive application group received LLLT for six consecutive days post-incision, three days pre-incision, or three consecutive days pre-SNL. The control group underwent skin incision or SNL without LLLT. The von Frey test was used to quantify the pain associated with mechanical allodynia. Pro-inflammatory cytokine level and alterations in nerve growth factor (NGF) expression were measured by using ELISA and immunohistochemistry, respectively in the skin, muscle of the paw, and spinal cord dorsal horn (SCDH). Results: In the incisional pain model, LLLT showed significant analgesic and preventive effect. LLLT ameliorated SNL-induced mechanical allodynia but LLLT had no preventive effect. LLLT decreased interleukin-1β (IL-1β) expression levels in the skin, muscle, and SCDH and reduced the optical density of skin and spinal cord NGF in the incisional pain model. Conclusions LLLT alleviated incisional pain and neuropathic pain caused by SNL in rats, and reduced the levels of IL-1β and NGF in the peripheral tissue and SCDH in the incisional pain model. LLLT might be effective in patients with post-operative pain and peripheral neuropathic pain.

Background/Aims: The genetic expression in the active inflammatory regions is increased in ulcerative colitis (UC) with endoscopic activity. The aim of this study was to investigate the molecular activity of inflammation and tissue remodeling markers in endoscopically inflamed and uninflamed regions of UC. Methods: Patients with UC (n=47) and controls (n=20) were prospectively enrolled at the Seoul National University Bundang Hospital. Inflamed tissue was obtained at the most active lesion, and uninflamed tissue was collected from approximately 15 cm above the upper end of the active lesion via colonoscopic biopsies. The messenger RNA expression levels of transforming growth factor β (TGF-β), interleukin (IL)-1β, IL-6, IL-17A, E-cadherin, olfactomedin-4 (OLFM4), leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), vimentin, fibroblast-specific protein-1 (FSP1), and α-smooth muscle actin (SMA) were evaluated. Mucosal healing (MH) was defined according to a Mayo endoscopic score of 0, 1 or non-MH (Mayo endoscopic score of 2 or 3). Results: The messenger RNA expressions of TGF-β, IL-1β, OLFM4, FSP1, vimentin, and α-SMA were significantly higher, and that of E-cadherin was significantly lower in inflamed and uninflamed regions of patients with UC than those in controls. In the inflamed regions, patients in the non-MH group had significantly increased genetic expression of TGF-β, FSP1, vimentin, and α-SMA compared to patients in the MH group. Similarly, the non-MH group had significantly higher genetic expression of TGF-β, IL-1β, IL-6, vimentin, and α-SMA than the MH group in the uninflamed regions. Conclusions Endoscopic activity in UC suggests inflammation and tissue remodeling of uninflamed regions similar to inflamed regions.

Osteoarthritis (OA) is a joint disorder caused by wear and tear of the cartilage that cushions the joints. It is a progressive condition that can cause significant pain and disability. Currently, there is no cure for OA, though there are treatments available to manage symptoms and slow the progression of the disease. A chondral defect is a common and devastating lesion that is challenging to treat due to its avascular and aneural nature. However, there are conventional therapies available, ranging from microfracture to cell-based therapy. Anyhow, its efficiency in cartilage defects is limited due to unclear cell viability. Exosomes have emerged as a potent therapeutic tool for chondral defects because they are a complicated complex containing cargo of proteins, DNA, and RNA as well as the ability to target cells due to their phospholipidic composition and the altering exosomal contents that boost regeneration potential. Exosomes are used in a variety of applications, including tissue healing and anti-inflammatory therapy. As in recent years, biomaterialsbased bio fabrication has gained popularity among the many printable polymer-based hydrogels, tissue-specific decellularized extracellular matrix might boost the effects rather than an extracellular matrix imitating environment, a short note has been discussed. Exosomes are believed to be the greatest alternative option for current cell-based therapy, and future progress in exosome-based therapy could have a greater influence in the field of orthopaedics. The review focuses extensively on the insights of exosome use and scientific breakthroughs centered OA.

Background: This study was designed to determine the current status of diagnosis and treatment of valvular heart disease (VHD) in Korea. Methods: A nationwide registry study was conducted in 45 hospitals in Korea involving adult patients with at least moderate VHD as determined by echocardiography carried out between September and October of 2019. Of a total of 4,094 patients with at least moderate VHD, 1,482 had severe VHD (age, 71.3 ± 13.5 years; 49.1% male). Echocar‑ diographic data used for the diagnosis of each case of VHD were analyzed. Experts from each center determined the diagnosis and treatment strategy for VHD based on current guidelines and institutional policy. The clinical out‑ come was in-hospital mortality. Results: Each valve underwent surgical or transcatheter intervention in 19.3% cases of severe mitral stenosis, 31.4% cases of severe primary mitral regurgitation (MR), 7.5% cases of severe secondary MR, 43.7% cases of severe aortic stenosis, 27.5% cases of severe aortic regurgitation, and 7.2% cases of severe tricuspid regurgitation. The overall inhospital mortality rate for patients with severe VHD was 5.4%, and for secondary severe MR and severe tricuspid regur‑ gitation, the rates were 9.0% and 7.5%, respectively, indicating a poor prognosis. In-hospital mortality occurred in 73 of the 1,244 patients (5.9%) who received conservative treatment and in 18 of the 455 patients (4.0%) who received a surgical or transcatheter intervention, which was significantly lower in the intervention group (P = 0.037). Conclusions This study provides important information about the current status of VHD diagnosis and treatment through a nationwide registry in Korea and helps to define future changes.