Purpose: To develop the 2025 update to the Korean colorectal cancer (CRC) screening guidelines by systematically evaluating recent evidence, integrating domestic data, and addressing changes since the 2015 guideline revision, thereby providing an evidence-based standard for clinicians and policymakers. Methods: A multidisciplinary committee developed the guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The process included formulation of three key questions addressing screening efficacy, diagnostic accuracy, and optimal screening age and interval. A systematic review of international guidelines and primary literature was conducted, yielding 327 eligible studies. In addition, a utility-based analysis using a Markov model was performed to determine optimal screening ages and intervals. Results: The evidence synthesis identified high-certainty evidence supporting the use of the fecal immunochemical test (FIT) for reducing CRC mortality and moderate-certainty evidence for colonoscopy. Evidence for computed tomographic colonography (CTC) and stool DNA testing was rated as very low certainty. Based on the evidence review and cost-utility analysis, the committee conditionally recommends CRC screening for asymptomatic, average-risk adults aged 45–74 years using either colonoscopy every 10 years or FIT every 1–2 years. CTC and stool DNA testing were not recommended owing to insufficient evidence. Conclusion The 2025 Korean Guidelines for Colorectal Cancer Screening present updated, evidence-based recommendations tailored to the domestic healthcare context. By conditionally endorsing both colonoscopy and FIT for individuals aged 45–74 years, these guidelines aim to improve population-level screening effectiveness and reduce the burden of CRC in South Korea.

Purpose: Immunochemical fecal occult blood tests (iFOBT) have been utilized as the primary method for colorectal cancer screening within Korea's National Cancer Screening Program. This study aimed to evaluate the impact of the accreditation program for clinical laboratories and external quality assessment (EQA) programs on colorectal cancer screening. Methods: We analyzed the false-positive rates of iFOBT in colorectal cancer screening from 2016 to 2020 according to participation and performance in the Outstanding Laboratory Accreditation Program (OLAP) conducted by the Laboratory Medicine Foundation, and the External Quality Assessment programs run by the Korean Association of External Quality Assessment Service. Results: False-positive rates of iFOBT were lower among institutions accredited by OLAP (2.35%) compared with non-accredited (3.04%) and non-participating institutions (5.60%). Similarly, institutions participating in the EQA program exhibited lower false-positive rates (3.79%) compared to non-participants (7.04%). Within the iFOBT-specific EQA program, institutions that passed demonstrated the lowest false-positive rate (3.37%), while failing institutions showed the highest rate (9.07%), surpassing even non-participating institutions (6.44%). Conclusion Participation in quality management programs such as OLAP and EQA was associated with lower false-positive rates in iFOBT for colorectal cancer screening. These findings suggest that quality management initiatives can increase the accuracy of iFOBT, potentially improving the effectiveness of colorectal cancer screening programs, and reducing unnecessary follow-up procedures and associated healthcare costs.

Purpose: Immunochemical fecal occult blood tests (iFOBT) have been utilized as the primary method for colorectal cancer screening within Korea's National Cancer Screening Program. This study aimed to evaluate the impact of the accreditation program for clinical laboratories and external quality assessment (EQA) programs on colorectal cancer screening. Methods: We analyzed the false-positive rates of iFOBT in colorectal cancer screening from 2016 to 2020 according to participation and performance in the Outstanding Laboratory Accreditation Program (OLAP) conducted by the Laboratory Medicine Foundation, and the External Quality Assessment programs run by the Korean Association of External Quality Assessment Service. Results: False-positive rates of iFOBT were lower among institutions accredited by OLAP (2.35%) compared with non-accredited (3.04%) and non-participating institutions (5.60%). Similarly, institutions participating in the EQA program exhibited lower false-positive rates (3.79%) compared to non-participants (7.04%). Within the iFOBT-specific EQA program, institutions that passed demonstrated the lowest false-positive rate (3.37%), while failing institutions showed the highest rate (9.07%), surpassing even non-participating institutions (6.44%). Conclusion Participation in quality management programs such as OLAP and EQA was associated with lower false-positive rates in iFOBT for colorectal cancer screening. These findings suggest that quality management initiatives can increase the accuracy of iFOBT, potentially improving the effectiveness of colorectal cancer screening programs, and reducing unnecessary follow-up procedures and associated healthcare costs.

Purpose: Immunochemical fecal occult blood tests (iFOBT) have been utilized as the primary method for colorectal cancer screening within Korea's National Cancer Screening Program. This study aimed to evaluate the impact of the accreditation program for clinical laboratories and external quality assessment (EQA) programs on colorectal cancer screening. Methods: We analyzed the false-positive rates of iFOBT in colorectal cancer screening from 2016 to 2020 according to participation and performance in the Outstanding Laboratory Accreditation Program (OLAP) conducted by the Laboratory Medicine Foundation, and the External Quality Assessment programs run by the Korean Association of External Quality Assessment Service. Results: False-positive rates of iFOBT were lower among institutions accredited by OLAP (2.35%) compared with non-accredited (3.04%) and non-participating institutions (5.60%). Similarly, institutions participating in the EQA program exhibited lower false-positive rates (3.79%) compared to non-participants (7.04%). Within the iFOBT-specific EQA program, institutions that passed demonstrated the lowest false-positive rate (3.37%), while failing institutions showed the highest rate (9.07%), surpassing even non-participating institutions (6.44%). Conclusion Participation in quality management programs such as OLAP and EQA was associated with lower false-positive rates in iFOBT for colorectal cancer screening. These findings suggest that quality management initiatives can increase the accuracy of iFOBT, potentially improving the effectiveness of colorectal cancer screening programs, and reducing unnecessary follow-up procedures and associated healthcare costs.

There is mounting epidemiologic and experimental evidence of the harmful effects of exposure to fine particulate matter (PM2.5) on human lung health. However, the current utilization of in vitro two-dimensional (2D) cell culture and in vivo animal models falls short in accurately recapitulating the complexity, functions, and development of the human lung. Recently, technologies for creating 3D biomimetic lung organoids from human tissue and pluripotent stem cells that mimic the structure and function of human organs have been rapidly developed. Human lung organoids are currently being applied in various studies such as disease modeling, drug efficacy testing, and regenerative medicine. In the field of environmental toxicology, human lung organoids offer a promising solution for more accurately assessing the health impacts of exposure to PM2.5 and to the limitations posed by 2D cultures and animal models. In this review, we summarize the effects of PM2.5 exposure on human lung and other organoids, as well as the molecular and genetic impacts of such exposure using human organoids. Furthermore, the development of lung-on-a-chip technology to mimic the microenvironment and its utilization for evaluating the pulmotoxicity of PM2.5 exposure are discussed.

Background and Objectives: Recent guidelines from the Korean Thyroid Association have proposed a threshold of 6.8 mIU/L for diagnosing subclinical hypothyroidism based on local research findings. However, due to the lack of standardization/harmonization, thyroid-stimulating hormone (TSH) testing yields varying results across different reagent manufacturers. Hence, the use of uniform reference intervals is challenging. We aimed to establish assay-specific Korean reference interval for TSH. Materials and Methods: We performed duplicate measurements on 100 serum samples with varying TSH concentrations (0-23 mIU/L) using eight different TSH reagents including Alinity I TSH (Abbott), Access TSH (Beckman Coulter), Elecsys TSH (Roche), TSH3UL (Siemens),TSH IRMA (Beckman Coulter), TSH1 RIA (Brahms), TSH IRMA TUBE II (Riakey), Turbo TSH IRMA (Izotop).Correlation and simple linear regression analyses were conducted among 8 reagents with Roche as the reference. Results The correlation coefficient for each reagent was notably high at 0.99. Through regression analysis, TSH values equivalent to the 6.8 mIU/L (Roche) were determined for each reagent as follows: Abbott 5.2 mIU/L, Beckman 6.5 mIU/L, Siemens 6.9 mIU/L, Beckman-Radioimmunoassay 7.4 mIU/L, Brahms 5.7 mIU/L, Riakey 5.3 mIU/L, Izotop 6.0 mIU/L. Conclusion: Given the observed differences in TSH values associated with different reagents, it is imperative to consider these differences when interpreting results within various clinical contexts and adapting them to clinical practice.

Objective: We implemented a novel resectable myocardial model for mock myectomy using a hybrid method of threedimensional (3D) printing and silicone molding for patients with apical hypertrophic cardiomyopathy (ApHCM). Materials and Methods: From January 2019 through May 2020, 3D models from three patients with ApHCM were generated using the end-diastolic cardiac CT phase image. After computer-aided designing of measures to prevent structural deformation during silicone injection into molding, 3D printing was performed to reproduce anatomic details and molds for the left ventricular (LV) myocardial mass. We compared the myocardial thickness of each cardiac segment and the LV myocardial mass and cavity volumes between the myocardial model images and cardiac CT images. The surgeon performed mock surgery, and we compared the volume and weight of the resected silicone and myocardium. Results: During the mock surgery, the surgeon could determine an ideal site for the incision and the optimal extent of myocardial resection. The mean differences in the measured myocardial thickness of the model (0.3, 1.0, 6.9, and 7.3 mm in the basal, midventricular, apical segments, and apex, respectively) and volume of the LV myocardial mass and chamber (36.9 mL and 14.8 mL, 2.9 mL and -9.4 mL, and 6.0 mL and -3.0 mL in basal, mid-ventricular and apical segments, respectively) were consistent with cardiac CT. The volume and weight of the resected silicone were similar to those of the resected myocardium (6 mL [6.2 g] of silicone and 5 mL [5.3 g] of the myocardium in patient 2; 12 mL [12.5 g] of silicone and 11.2 mL [11.8 g] of the myocardium in patient 3). Conclusion Our 3D model created using hybrid 3D printing and silicone molding may be useful for determining the extent of surgery and planning surgery guided by a rehearsal platform for ApHCM.

Objective: We implemented a novel resectable myocardial model for mock myectomy using a hybrid method of threedimensional (3D) printing and silicone molding for patients with apical hypertrophic cardiomyopathy (ApHCM). Materials and Methods: From January 2019 through May 2020, 3D models from three patients with ApHCM were generated using the end-diastolic cardiac CT phase image. After computer-aided designing of measures to prevent structural deformation during silicone injection into molding, 3D printing was performed to reproduce anatomic details and molds for the left ventricular (LV) myocardial mass. We compared the myocardial thickness of each cardiac segment and the LV myocardial mass and cavity volumes between the myocardial model images and cardiac CT images. The surgeon performed mock surgery, and we compared the volume and weight of the resected silicone and myocardium. Results: During the mock surgery, the surgeon could determine an ideal site for the incision and the optimal extent of myocardial resection. The mean differences in the measured myocardial thickness of the model (0.3, 1.0, 6.9, and 7.3 mm in the basal, midventricular, apical segments, and apex, respectively) and volume of the LV myocardial mass and chamber (36.9 mL and 14.8 mL, 2.9 mL and -9.4 mL, and 6.0 mL and -3.0 mL in basal, mid-ventricular and apical segments, respectively) were consistent with cardiac CT. The volume and weight of the resected silicone were similar to those of the resected myocardium (6 mL [6.2 g] of silicone and 5 mL [5.3 g] of the myocardium in patient 2; 12 mL [12.5 g] of silicone and 11.2 mL [11.8 g] of the myocardium in patient 3). Conclusion Our 3D model created using hybrid 3D printing and silicone molding may be useful for determining the extent of surgery and planning surgery guided by a rehearsal platform for ApHCM.

BACKGROUND: Molecular epidemiological typing of Neisseria gonorrhoeae is crucial for monitoring the spread of resistant strains. As reference strains can be used for laboratory internal quality control, we genetically characterised the American Type Culture Collection (ATCC) gonococcal strains by Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) and porB sequence typing using public multilocus sequence typing (PubMLST). METHODS: Eight ATCC gonococcal reference strains (ATCC 19424, ATCC 31426, ATCC 35541, ATCC 43069, ATCC 43070, ATCC 49226, ATCC 49926, and ATCC 49981) from Culti-Loops (Thermo Fisher Scientific, USA) were cultured. After DNA extraction, porB and tbpB were amplified and sequenced. Sequence types (STs) and allele numbers were each determined by NG-MAST (http://www.ng-mast.net) and porB sequence typing using PubMLST (http://pubmlst.org/neisseria/porB/). RESULTS: ATCC 19424 was identified as ST 266 by NG-MAST, and as Allele 946 by PubMLST. ATCC31426 was assigned a novel ST by NG-MAST, and was assigned Allele 958 with 1.2% mismatch by PubMLST. ATCC 35541 was identified as ST 12 by NG-MAST, and as Allele 624 by PubMLST. ATCC 43069 and ATCC 43070 were both identified as ST 681 by NG-MAST, and as Allele 984 by PubMLST. ATCC 49226 was identified as ST 1572 by NG-MAST, and as Allele 2110 by PubMLST. ATCC 49926 and ATCC 49981 were both identified as ST 16496 by NG-MAST, and as Allele 928 by PubMLST. CONCLUSIONS: The ST data obtained for ATCC gonococcal reference strains by NG-MAST and porB sequence typing using PubMLST can be used for quality assurance of molecular epidemiological typing in clinical microbiological laboratories.
Alleles ; DNA ; Multilocus Sequence Typing ; Neisseria gonorrhoeae ; Neisseria ; Quality Control

BACKGROUND: The gold standard in dysarthria assessment involves subjective analysis by a speech–language pathologist (SLP). We aimed to investigate the feasibility of dysarthria assessment using automatic speech recognition. METHODS: We developed an automatic speech recognition based software to assess dysarthria severity using hidden Markov models (HMMs). Word-specific HMMs were trained using the utterances from one hundred healthy individuals. Twenty-eight patients with dysarthria caused by neurological disorders, including stroke, traumatic brain injury, and Parkinson's disease were participated and their utterances were recorded. The utterances of 37 words from the Assessment of Phonology and Articulation for Children test were recorded in a quiet control booth in both groups. Patients were asked to repeat the recordings for evaluating the test–retest reliability. Patients' utterances were evaluated by two experienced SLPs, and the consonant production accuracy was calculated as a measure of dysarthria severity. The trained HMMs were also employed to evaluate the patients' utterances by calculating the averaged log likelihood (aLL) as the fitness of the spoken word to the word-specific HMM. RESULTS: The consonant production accuracy reported by the SLPs strongly correlated (r = 0.808) with the aLL, and the aLL showed excellent test–retest reliability (intraclass correlation coefficient, 0.964). CONCLUSION: This leads to the conclusion that dysarthria assessment using a one-word speech recognition system based on word-specific HMMs is feasible in neurological disorders.
Brain Injuries ; Child ; Dysarthria ; Humans ; Nervous System Diseases ; Parkinson Disease ; Stroke