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Background Endoscopic ultrasound-elastography (EUS-EG) is a non-invasive complementary diagnostic method for the differential diagnosis of solid pancreatic lesions (SPL). However, the optimal strain ratio (SR) value and diagnostic performance of EUS-EG have not yet been determined in pancreatic neuroendocrine neoplasm (PNEN), mass-forming pancreatitis (MFP), and pancreatic ductal adenocarcinoma (PDAC). We aimed to determine the optimal SR value in EUS-EG for differential diagnosis of SPLs. Methods A total 134 patients who underwent EUS-EG to evaluate SPL were retrospectively investigated. Patients were divided into 3 groups – PNEN (n=10), MFP (n=37), and PDAC (n=87). Baseline characteristics and results of EUS-EG were compared between groups and statistical analyses were performed for differential diagnosis. Results The mean SR values of each group were 11.85±7.56 (PNEN), 11.45±5.97 (MFP), and 22.50 ± 13.19 (PDAC), respectively. There was significant association between SR value increase and PDAC diagnosis (PNEN versus PDAC, p=0.0216; MFP versus PDAC, p=0.0006) in multinomial logistic regression analysis. SR value of 17.14 was confirmed as the optimal cut-off value for differential diagnosis between MFP and PDAC. Conclusions Differential diagnosis of SPL could be performed using EUS-EG. The cut-off SR value presented in this study is expected to be useful in differential diagnosis. Clinical trial registration number: https://cris.nih.go.kr/cris : KCT0002082

Given that tooth loss is a degenerative change, the number of residual teeth may be used to specify a particular age range as a marker for age estimation. This study examined changes in the number of teeth with age using a nationwide oral survey database and derived the age distribution of the Korean population according to the number of teeth. Data on the number of teeth and age were extracted from the oral examination data of the Korean National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2018. Statistical analyses of a complex sample survey were performed using weighted values. The distribution range of the number of teeth by age was broad. The proportion of young people decreased progressively as the number of remaining teeth decreased. In contrast, the proportion of those from the older age group decreased slightly as the number of teeth increased. The number of teeth was subdivided into groups of four, age was categorized into 5-year intervals, and the distribution of age groups by the number of teeth was analyzed. We attempted to determine the age group threshold at approximately 95th percentile for age. In summary, we found that if there were ≤4, 5-12, and 13-20 residual teeth, the estimated age was ≥60, ≥55, and ≥50 years, respectively, with an approximately 95% probability. When many teeth are lost and it is difficult to apply conventional dental age estimation methods, our method may assist in narrowing the age range, although it is not an accurate age determination method.

For the study on the relationships between the seed dispersal of exotic plants and bird population, flora, avifauna, vegetation patches, and the dynamics of seed banks were investigated in and around the exposed floodplains of the large rivers, and the causes of exotic vegetation development were determined with respect to plant life form, bird population characteristics, and landscape using multivariate analysis. The number of dominant exotic plant species observed in exposed areas was higher than that observed in an abandoned field and paddy field undergoing secondary succession. Additionally, the area occupied by exotic vegetation in exposed areas increased with the increase in number of vine plants and small terrestrial birds, whereas the relationship between vine and runner plants was inversely proportional. Therefore, to control exotic plants in exposed floodplains surrounding large rivers, it is necessary to remove vines and shrubs along the waterfront where small resident birds carrying plant seeds live and to maintain and manage runner plant populations. Furthermore, implementing an ecological landscape management strategy, such as afforestation through the planting of trees, may also be effective.

Hulunbuir steppe, one of the four largest grasslands in the world, is suffering progressing desertification due to climate change and anthropogenic disturbance. In this study, the plant species and communities were analyzed with CSR ecological strategies for the succession process that occurred following the introduction of woody plants in the restored site in the damaged steppe, and compared with those in the reference site in an attempt to find the lifeform characteristics of plants in grasslands and implications for success in ecological restoration. According to the results, the introduction of woody plants into the damaged land greatly increased the diversity of plant species and CSR eco-functional diversity as the succession progressed. The types of ecological strategies of the temperate typical steppe (TTS) and woodland steppe (WS) in this region are CSR and S/SR, respectively, which means that plants in the temperate Asian steppe are species basically adapted to natural disturbances such as drying and soil movement. As the restoration time elapsed in the damaged lands (R/CR), the ecological strategies were predicted to change in two ways: R/CR→R/CSR→CSR (TSS) in places where only shrubs were introduced, and S/SR→S/SR (WS) in places where trees and shrubs were introduced simultaneously. The results as such mean that the driving force that causes succession in the restoration of temperate grasslands is determined by the lifeform (trees/shrubs) of the introduced woody plants, and therefore, it is judged that trees or shrubs should be selected and introduced bearing the final target vegetation in mind when planning restoration.

Endoscopic ultrasound (EUS)-guided hepaticogastrostomy (HGS) may be a feasible and useful alternative in patients with malignant biliary obstruction (MBO) after failed endoscopic retrograde cholangiopancreatography (ERCP). To date, the risk factors for adverse events (AEs) and long-term outcomes of EUS-HGS have not been fully explored according to stent type. Therefore, we evaluated potential risk factors for AEs and long-term outcomes of EUS-HGS.In total, 120 patients who underwent EUS-HGS were retrospectively reviewed. A multivariate analysis through Cox proportional hazard and logistic regression model was used to identify the risk factors for stent dysfunction and AEs, respectively. Stent patency and patient survival were evaluated using Kaplan-Meier plots with a log-rank test for each stent.The technical and clinical success rates were 96.2% (102/106) and 83.0% (88/106). The median duration of stent patency was longer in self-expandable metal stents (SEMS) compared to plastic stents (PS) (158 vs. 108 days). Kaplan-Meier analysis indicated that the type of stent was not associated with stent patency (Hazard ratios [HR] 0.997, 95% confidence interval [CI] [0.525-1.896]) or overall survival. In addition, multivariate analysis indicated that hilar MBO significantly associated with stent dysfunction (HR, 2.340; 95% CI, 1.028-5.326, p = 0.043) and late AEs.Given the lower incidence of AEs and better long-term outcomes of EUS-HGS, it can be considered a safe alternative to ERCP or percutaneous approaches regardless of which stent is used. Furthermore, hilar MBO was established as a potential risk factor for stent dysfunction and late AEs.

Malignant hilar biliary obstruction (MHBO) frequently accompanies cholestasis and cholangitis, and requires biliary stent placement. To prevent stent occlusion and prolong survival, local ablation therapy can be considered adjunctive to stent placement. Intraductal radiofrequency ablation (ID-RFA) is a recently developed local therapy for malignant biliary obstruction that can be easily performed employing endoscopic retrograde cholangiography. The use of ID-RFA to treat MHBO (as distinct from distal biliary obstruction) was suggested to be associated with severe adverse events. However, recent comparative studies have shown that ID-RFA is feasible and safe, and acceptably efficacious, in patients with advanced MHBO; newer temperature-controlled ID-RFA devices may enhance safety further. Regularly repeated ID-RFA with stent exchange affords better survival than stenting alone. However, the optimal ID-RFA strategy for MHBO remains inconclusive given the lack of data. Further large-scale clinical trials are needed.

Initial and convalescent treatment of acute pancreatitis (AP) is important in order to improve the prognosis and prevent the recurrence in the patients with AP. Initial intensive treatment includes fluid therapy, pain control, antimicrobial therapy, endoscopic retrograde cholangiopancreatography (ERCP), and nutritional support. Goal-directed therapy is recommended for fluid therapy, and the routine use of prophylactic antibiotics is not recommended. In acute gallstone pancreatitis, urgent ERCP should be performed only in patients with cholangitis or persistent cholestasis. Early oral feeding is advisable as tolerated and enteral feeding via nasogastric or nasojejunal tube appear comparable. In convalescent treatment, cholecystectomy during the initial admission is advisable for mild biliary pancreatitis with gallstone as possible, and treatment against alcohol dependence is considerable for recurrent acute alcoholic pancreatitis. In this review, we recommend practice guidelines for initial treatment, nutritional support, and convalescent treatment.

Background and Aims Contrast-enhanced harmonic EUS (CEH-EUS) is useful in the differential diagnosis of solid pancreatic lesions (SPLs). However, there is lack of verification about the usefulness of CEH-EUS–guided FNA/fine-needle biopsy (FNB) sampling. This study aimed to investigate the usefulness of CEH-EUS–guided FNA/FNB sampling without on-site cytopathology. Methods Patients with SPLs were prospectively enrolled and randomly assigned (1:1) to 2 parallel groups, the interventional group (CEH-EUS) or the control group (conventional EUS). The diagnostic sensitivity and optimal number of needle passes for pathologic diagnosis were investigated and compared between groups. Results Two hundred forty patients were enrolled from March 2016 to September 2019, with 120 patients assigned to each group. Pancreatic malignancies and neuroendocrine tumors were found in 202 (90.83%) and 9 (3.75%) patients, respectively. There was no statistically significant difference between the groups in terms of age, sex, lesion size (30.96 ± 12.09 mm in the CEH-EUS group vs 33.09 ± 16.39 mm in the conventional EUS group; P = .252), lesion location, adverse event rate, and disease distribution. The diagnostic sensitivity values in the CEH-EUS and conventional EUS groups were 85.8% and 88.3%, respectively (P = .564). All patients in the conventional EUS group and most in the CEH-EUS group received a pathologic diagnosis within 3 needle passes. Conclusions Diagnostic sensitivity for SPLs was not different between the CEH-EUS and conventional EUS groups, and no independent factors were found that could improve diagnostic sensitivity. CEH-EUS–guided FNA/FNB sampling does not need to be used routinely and may be selectively considered for small, indeterminate lesions. (Clinical trial registration number: KCT 0001840.)

In patients with unresectable malignant biliary obstruction (MBO), endoscopic drainage with a self-expandable metal stent (SEMS) is a well-established treatment, but stent patency is limited. This study aimed to evaluate the efficacy of in-stent radiofrequency ablation (IS-RFA) followed by uncovered SEMS placement for the management of occluded SEMSs.From 2016 to 2020, 48 patients with recurrent biliary obstruction due to tumor ingrowth or overgrowth after SEMS placement for pancreatobiliary cancer in three tertiary hospitals were analyzed. For distal MBO, patients in RFA group were treated with IS-RFA and uncovered SEMS placement, and those in control group were treated with uncovered SEMS placement alone. Patients in both groups were matched based on propensity scores in a 1:1 ratio.The median time to recurrent biliary obstruction (TRBO) was 117 days in the RFA group and 82.5 days in the control group (p = 0.029). No significant differences in median overall survival were detected between the two groups (170 days vs. 72 days, p = 0.902). No significant adverse events were reported after the second SEMS placement in either group, but two cases of mild cholangitis were reported in the control group. Ablation was interrupted in five patients (35.7%) from the RFA group due to in-stent contact, but sufficient ablative energy was delivered in majority of the patients after repeating the IS-RFA (92.9%) in the same session.IS-RFA followed by uncovered SEMS is safe and feasible and may improve TRBO as a stent revision for occluded SEMS in pancreatobiliary cancer.

In this study, we examined the feasibility of Myzus persicae proliferation through interrelationships with host plants in a smart farm facility during winter. We investigated aphid proliferation under an LED artificial light source and attempted to interpret aphid proliferation in relation to the net photosynthetic rate of the host plant, Eutrema japonicum. We observed that aphids continuously proliferated in the smart farm facility in winter without dormancy. The average number of aphids was greater under the 1:1 red:blue light irradiation time ratio, where the photosynthetic rate of the host plant was lower than under the 5:1 and 10:1 red:blue light irradiation time ratios. These results show that it is important to maintain a low net photosynthetic rate of the host plant, E. japonicum, in order to effectively proliferate aphids under artificial light such as in the case of smart farm facilities.

Acute pancreatitis can range from a mild, self-limiting disease requiring no more than supportive care, to severe disease with life-threatening complications. With the goal of providing a recommendation framework for clinicians to manage acute pancreatitis, and to contribute to improvements in national health care, the Korean Pancreatobiliary Association (KPBA) established the Korean guidelines for acute pancreatitis management in 2013. However, many challenging issues exist which often lead to differences in clinical practices. In addition, with newly obtained evidence regarding acute pancreatitis, there have been great changes in recent knowledge and information regarding this disorder. Therefore, the KPBA committee underwent an extensive revision of the guidelines. The revised guidelines were developed using the Delphi method, and the main topics of the guidelines include the following: diagnosis, severity assessment, initial treatment, nutritional support, convalescent treatment, and the treatment of local complications and necrotizing pancreatitis. Specific recommendations are presented, along with the evidence levels and recommendation grades.

In a recent randomized controlled trial, a double bare metal stent (DBS) showed better stent patency than single-layer metal stents. However, clear evidence comparing the efficacy of uncovered (UCDBS) and partially covered (PCDBS) DBSs for distal malignant biliary obstruction (MBO) is lacking. Therefore, we compared the clinical outcomes including stent patency of UCDBSs versus PCDBSs.A multicenter, randomized study was performed in patients with distal MBO. The primary endpoint was stent patency. Secondary endpoints were the proportion of patients with patent stents at 6 months, risk factors for stent dysfunction, overall survival, technical and clinical success rates of stent placement, and other adverse events (AEs).Among 258 included patients, 130 were randomly assigned to the PCDBS group and 128 to the UCDBS group. The mean duration of stent patency of the PCDBS (421.2 days; 95% confidence interval [CI], 346.7-495.7) was longer than that of the UCDBS (377.4 days; 95% CI, 299.7-455.0), although total stent dysfunction and stent dysfunction within 6 months were not different between groups. Multivariate analysis indicated that chemotherapy after stent placement was a significant factor for overall survival (hazard ratio, .570; 95% CI, .408-.796) and had a marginal impact on stent patency (hazard ratio, 1.569; 95% CI, .923-2.667). There were no remarkable differences in AEs, including pancreatitis, cholecystitis, and stent migration, between the 2 groups.The use of PCDBSs compared with UCDBSs in patients with distal MBO has unclear benefits regarding stent patency and overall survival, although PCDBSs have a lower rate of tumor ingrowth. (Clinical trial registration number: NCT02937246.).

Background and study aims Although routine preoperative biliary drainage (PBD) in patients with distal malignant biliary obstruction is generally not recommended, there are still various situations where it may be necessary. The current study aims to compare between the uncovered self-expandable metal stent (uSEMS) and plastic stent (PS), where PBD may be necessary. Patients and methods In this multicenter prospective randomized study, patients with resectable periampullary cancer with cholangitis, deep jaundice, or expected long waiting time for surgery were included. PBD was performed endoscopically, but percutaneous drainage was allowed if the initial endoscopic drainage was not feasible. The primary outcome was the reintervention rate; the secondary outcomes were the complication rates, rate of decrease of total bilirubin, waiting time for surgery, and postoperative hospital stay. Results Of the 60 enrolled patients, 53 were included for analysis (26 PS and 27 uSEMS). Common bile duct cancer was the most common (27, 50.9%), followed by pancreatic head cancer (20, 37.7%). Regarding PBD indication, 36 (67.9%) had cholangitis and 21 (39.6%) had a total bilirubin level of more than 10mg/dL at randomization; 10 (18.9%) were included due to delayed surgery by more than seven days. Fifty (94.3%) patients received pancreaticoduodenectomy, and one (1.9%) patient received palliative hepaticojejunostomy. The median waiting time for surgery was 11.0 days. There was no difference in the reintervention rate (3.8% and 3.8% in PS and uSEMS, P > 0.999), PBD-related complication rate (23.1% and 22.2%, P > 0.999), PBD- or surgery-related complication rate (57.7% and 48.1%, P = 0.674), and the rate of decrease of total bilirubin (P=0.541). The median hospital stay after surgery was 13.0 days without significant difference. Conclusion For patients who received surgery within the first two weeks from receiving PBD, there was no superiority of uSEMS to PS. According to the expected waiting time for surgery, selective approach for stent choice should be considered.

Hypertriglyceridemia (HTG) is a well-known cause of acute pancreatitis (AP) and elevation of serum triglycerides (TG) to ≥1000 mg/dl is strongly indicative of HTG-induced AP (HTG-AP). HTG-AP is potentially associated with persistent organ failure and poor prognosis. Here, we compared differences in clinical features and outcomes between patients with HTG-AP and patients with AP due to other causes.A prospective AP registry was constructed in Gil Medical Center between June 2014 and May 2018. In total, 499 patients with AP were included for whom serum TG data at admission were available.HTG-AP was present in 52 patients (10.4%); these patients were younger than patients with AP due to other causes (39.62 ± 10.12 vs. 51.62 ± 17.41, p 0.001). After propensity score matching adjusted by age, the factors associated with severity were more common in the HTG-AP group; these factors included the presence of systemic inflammatory response syndrome, Ranson's score ≥3, acute physiology, age, chronic health evaluation (APACHE) II score ≥8 at admission, and C-reactive protein level10 mg/dl after 24 h of hospitalization. There were no significant differences in complications or severity based on the revised Atlanta classification 2012. In addition, recurrence was more frequent in the HTG-AP group (25.0% vs. 6.4%, p 0.001).HTG-AP occurred in younger patients and showed more frequent recurrences than AP with other causes. Although factors related to severe feature were more common in HTG-AP during early phase, overall severity and prognosis were not different between the two groups.

Purpose We aimed to evaluate the efficacy and safety of temperature-controlled intraductal radiofrequency ablation (ID-RFA) for advanced malignant hilar biliary obstruction (MHBO). Methods Patients were randomly assigned to RFA group (ID-RFA and bilateral plastic stent [PS]) or non-RFA group (bilateral PS) at a 1:1 ratio. Exchange to self-expanding metal stent (SEMS) was performed after three months or when premature PS occlusion occurred. Total event-free stent patency, overall survival (OS), and adverse events (AEs) were analyzed. Results A total of 30 patients from three hospitals were enrolled. Stent patency and OS did not differ between the two groups (178 days vs. 122 days, P = 0.154; 230 days vs. 144 days, P = 0.643; respectively). In patients with each stricture length ≥ 11 mm on both sides, stent patency was longer in the RFA group than in the non-RFA group (175 days vs. 121 days, P = 0.028). More patients received elective exchange to SEMS without PS occlusion in the RFA group than in the non-RFA group (69.2% vs. 23.1%, P = 0.018). AE rates did not differ between the two groups. Conclusions Temperature-controlled ID-RFA for advanced MHBO was safe and feasible. It could prevent premature PS occlusion within 3 months.

Simple Summary Neuroendocrine neoplasms (NENs) of the gallbladder (GB) are extremely rare. We aimed to compare the clinical features of GB-NENs with those of adenocarcinomas (ADCs) of the GB. Among 21 patients with GB-NENs, 20 were diagnosed with poorly differentiated small-cell neuroendocrine carcinoma (NEC), and 1 patient had large-cell NEC. At initial presentation, all patients had advanced stages of cancer, with extensive local extension and/or distant metastasis. Nine patients with GB-NEC who underwent surgical resection had a significantly better progression-free survival (PFS) than those who did not undergo surgery. After a propensity score matching with a 1:1 ratio using the American Joint Committee on Cancer (AJCC) stage, age, sex, and operation status, there was no difference in the overall survival or PFS between AJCC stage-matched patients with GB-NEC or GB-ADC. In conclusion, GB-NEC is difficult to diagnose early and has a prognosis similar to that of GB-ADC. Abstract Neuroendocrine neoplasms (NENs) of the gallbladder (GB) are extremely rare. We aimed to compare the clinical features, disease progression, management, and prognosis of patients with GB-NENs with those of patients with GB-adenocarcinomas (ADCs). A total of 21 patients with GB-NENs and 206 patients with GB-ADCs, treated at three tertiary medical centers between January 2010 and December 2020, were enrolled. Of the 21 patients with GB-NENs, 20 were diagnosed with poorly differentiated small-cell neuroendocrine carcinomas (NECs), and 1 patient had large-cell NEC. All patients presented with advanced stages of cancer with extensive local extension and/or distant metastasis and non-specific symptoms. Tumor-node-metastasis stage IIIB and IV (A/B) tumors were found in 6 and 15 (1/14) patients, respectively. Nine patients with GB-NEC who underwent surgical resection had a significantly better progression-free survival (PFS) than those who did not undergo surgery. After a propensity score matching with a 1:1 ratio using the American Joint Committee on Cancer stage, age, sex, and operation status, 19 pairs of patients were included. Compared with stage-matched patients with GB-ADC, patients with GB-NEC had similar overall survival and PFS. However, as GB-NEC is rarely diagnosed early, further studies investigating methods for the early diagnosis and improvement in the survival of patients with GB-NEC are needed.

BACKGROUND AND AIM Endoscopic ultrasound (EUS) is the most accurate diagnostic modality for polypoid lesions of the gallbladder (GB), but is limited by subjective interpretation. Deep learning-based artificial intelligence (AI) algorithms are under development. We evaluated the diagnostic performance of AI in differentiating polypoid lesions using EUS images. METHODS The diagnostic performance of the EUS-AI system with ResNet50 architecture was evaluated via three processes: training, internal validation, and testing using an AI development cohort of 1039 EUS images (836 GB polyps and 203 gallstones). The diagnostic performance was verified using an external validation cohort of 83 patients and compared with the performance of EUS endoscopists. RESULTS In the AI development cohort, we developed an EUS-AI algorithm and evaluated the diagnostic performance of the EUS-AI including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. For the differential diagnosis of neoplastic and non-neoplastic GB polyps, these values for EUS-AI were 57.9%, 96.5%, 77.8%, 91.6%, and 89.8%, respectively. In the external validation cohort, we compared diagnostic performances between EUS-AI and endoscopists. For the differential diagnosis of neoplastic and non-neoplastic GB polyps, the sensitivity and specificity were 33.3% and 96.1% for EUS-AI; they were 74.2% and 44.9%, respectively, for the endoscopists. Besides, the accuracy of the EUS-AI was between the accuracies of mid-level (66.7%) and expert EUS endoscopists (77.5%). CONCLUSIONS This newly developed EUS-AI system showed favorable performance for the diagnosis of neoplastic GB polyps, with a performance comparable to that of EUS endoscopists.