Suicidal cases involving sodium nitrite have been reported worldwide. However, postmortem features, such as brownish or grayish livor mortis, remain difficult to interpret, especially as decomposition advances. Here, we present three fatal cases (2020-2023) presumably caused by sodium nitrite ingestion. In these cases, characteristic nitrite-induced changes were inconsistent or obscured by decomposition, but ingestion traces (cup or bottle near the decedents) were observed at each scene. Additionally, containers labeled “sodium nitrite” were found in two cases; however, since sodium nitrite is designated a suicide-hazardous material in South Korea, future scenes may rarely reveal such clear labeling. Although autopsy, including methemoglobin testing, can confirm the cause of death, any delay in the investigative process risks the loss of critical evidence about the ingestion process and other factors. This underscores the importance of focusing on early scene evidence, particularly ingestion traces, and conducting thorough chemical and forensic examinations. Our findings illustrate that timely detection of ingestion-related evidence and subsequent forensic analysis, in conjunction with autopsy results, can elucidate a decedent’s cause and manner of death and clarify any criminal implications.

Suicidal cases involving sodium nitrite have been reported worldwide. However, postmortem features, such as brownish or grayish livor mortis, remain difficult to interpret, especially as decomposition advances. Here, we present three fatal cases (2020-2023) presumably caused by sodium nitrite ingestion. In these cases, characteristic nitrite-induced changes were inconsistent or obscured by decomposition, but ingestion traces (cup or bottle near the decedents) were observed at each scene. Additionally, containers labeled “sodium nitrite” were found in two cases; however, since sodium nitrite is designated a suicide-hazardous material in South Korea, future scenes may rarely reveal such clear labeling. Although autopsy, including methemoglobin testing, can confirm the cause of death, any delay in the investigative process risks the loss of critical evidence about the ingestion process and other factors. This underscores the importance of focusing on early scene evidence, particularly ingestion traces, and conducting thorough chemical and forensic examinations. Our findings illustrate that timely detection of ingestion-related evidence and subsequent forensic analysis, in conjunction with autopsy results, can elucidate a decedent’s cause and manner of death and clarify any criminal implications.

Suicidal cases involving sodium nitrite have been reported worldwide. However, postmortem features, such as brownish or grayish livor mortis, remain difficult to interpret, especially as decomposition advances. Here, we present three fatal cases (2020-2023) presumably caused by sodium nitrite ingestion. In these cases, characteristic nitrite-induced changes were inconsistent or obscured by decomposition, but ingestion traces (cup or bottle near the decedents) were observed at each scene. Additionally, containers labeled “sodium nitrite” were found in two cases; however, since sodium nitrite is designated a suicide-hazardous material in South Korea, future scenes may rarely reveal such clear labeling. Although autopsy, including methemoglobin testing, can confirm the cause of death, any delay in the investigative process risks the loss of critical evidence about the ingestion process and other factors. This underscores the importance of focusing on early scene evidence, particularly ingestion traces, and conducting thorough chemical and forensic examinations. Our findings illustrate that timely detection of ingestion-related evidence and subsequent forensic analysis, in conjunction with autopsy results, can elucidate a decedent’s cause and manner of death and clarify any criminal implications.

Suicidal cases involving sodium nitrite have been reported worldwide. However, postmortem features, such as brownish or grayish livor mortis, remain difficult to interpret, especially as decomposition advances. Here, we present three fatal cases (2020-2023) presumably caused by sodium nitrite ingestion. In these cases, characteristic nitrite-induced changes were inconsistent or obscured by decomposition, but ingestion traces (cup or bottle near the decedents) were observed at each scene. Additionally, containers labeled “sodium nitrite” were found in two cases; however, since sodium nitrite is designated a suicide-hazardous material in South Korea, future scenes may rarely reveal such clear labeling. Although autopsy, including methemoglobin testing, can confirm the cause of death, any delay in the investigative process risks the loss of critical evidence about the ingestion process and other factors. This underscores the importance of focusing on early scene evidence, particularly ingestion traces, and conducting thorough chemical and forensic examinations. Our findings illustrate that timely detection of ingestion-related evidence and subsequent forensic analysis, in conjunction with autopsy results, can elucidate a decedent’s cause and manner of death and clarify any criminal implications.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: adenoma ≥10 mm in size; 3 to 5 (or more) adenomas; tubulovillous or villous adenoma; adenoma containing high-grade dysplasia; traditional serrated adenoma; sessile serrated lesion containing any grade of dysplasia; serrated polyp of at least 10 mm in size; and 3 to 5 (or more) sessile serrated lesions. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: 1) adenoma ≥10 mm in size; 2) 3-5 (or more) adenomas; 3) tubulovillous or villous adenoma; 4) adenoma containing high-grade dysplasia; 5) traditional serrated adenoma; 6) sessile serrated lesion (SSL) containing any grade of dysplasia; 7) serrated polyp of at least 10 mm in size; and 8) 3-5 (or more) SSLs. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for the management of advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: (1) adenoma ≥10 mm in size; (2) 3 to 5 (or more) adenomas; (3) tubulovillous or villous adenoma; (4) adenoma containing high-grade dysplasia; (5) traditional serrated adenoma; (6) sessile serrated lesion (SSL) containing any grade of dysplasia; (7) serrated polyp of at least 10 mm in size; and (8) 3 to 5 (or more) SSLs. More studies are needed to fully comprehend the patients most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Background/Aims: The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested.This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy. Methods: We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR. Results: A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001). Conclusions The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy.

Background/Aims: Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) can serve as biomarkers for diagnosing and assessing disease activity in ulcerative colitis (UC). We investigated their clinical significance in UC. Methods: We analyzed 48 patients with UC who underwent measurement of fecal calprotectin (FC) and endoscopy and 96 age- and sex-matched healthy controls. NLR and PLR were compared between the patients and healthy controls. The endoscopic activity was divided into 2 groups: group 1 (mild to moderate inflammation) and group 2 (severe inflammation) according to the Mayo endoscopic subscore in UC. Results: To diagnose UC, the optimal cutoff of NLR and PLR was 2.26 (sensitivity 54.2%; specificity 90.6%; positive likelihood ratio 5.778, 95% confidence interval [CI] 2.944–11.339; area under the curve [AUC] 0.774, 95% CI, 0.690–0.859) and 179.8 (sensitivity 35.4%; specificity 90.6%; positive likelihood ratio 3.778, 95% CI 1.821–7.838; AUC 0.654, 95% CI 0.556–0.753), respectively. The optimal cutoff to differentiate group 1 and group 2 was 3.44, 175.9, and 453 µg/g for NLR, PLR, and FC, respectively (sensitivity, 63.6% vs. 90.9% vs. 81.8%; specificity, 81.1% vs. 78.4% vs. 73.0%; positive likelihood ratio, 3.364 vs. 4.205 vs. 3.027; AUC, 0.714 vs. 0.897 vs. 0.813). PLR had the highest AUC and positive likelihood ratio. Conclusions NLR and PLR help differentiate patients with UC from healthy controls. NLR, PLR, and FC indicate endoscopic activity and may reflect intestinal mucosal conditions.

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel.There may be more transmissions with this VOC in Korea than reported.